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okias
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Jul 13, 2021
ASan reports a heap-buffer-overflow in elf_sec__is_text when using perf-top.
The bug is caused by the fact that secstrs is built from runtime_ss, while
shdr is built from syms_ss if shdr.sh_type != SHT_NOBITS. Therefore, they
point to two different ELF files.
This patch renames secstrs to secstrs_run and adds secstrs_sym, so that
the correct secstrs is chosen depending on shdr.sh_type.
$ ASAN_OPTIONS=abort_on_error=1:disable_coredump=0:unmap_shadow_on_exit=1 ./perf top
=================================================================
==363148==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x61300009add6 at pc 0x00000049875c bp 0x7f4f56446440 sp 0x7f4f56445bf0
READ of size 1 at 0x61300009add6 thread T6
#0 0x49875b in StrstrCheck(void*, char*, char const*, char const*) (/home/user/linux/tools/perf/perf+0x49875b)
#1 0x4d13a2 in strstr (/home/user/linux/tools/perf/perf+0x4d13a2)
#2 0xacae36 in elf_sec__is_text /home/user/linux/tools/perf/util/symbol-elf.c:176:9
#3 0xac3ec9 in elf_sec__filter /home/user/linux/tools/perf/util/symbol-elf.c:187:9
#4 0xac2c3d in dso__load_sym /home/user/linux/tools/perf/util/symbol-elf.c:1254:20
#5 0x883981 in dso__load /home/user/linux/tools/perf/util/symbol.c:1897:9
#6 0x8e6248 in map__load /home/user/linux/tools/perf/util/map.c:332:7
#7 0x8e66e5 in map__find_symbol /home/user/linux/tools/perf/util/map.c:366:6
#8 0x7f8278 in machine__resolve /home/user/linux/tools/perf/util/event.c:707:13
grate-driver#9 0x5f3d1a in perf_event__process_sample /home/user/linux/tools/perf/builtin-top.c:773:6
grate-driver#10 0x5f30e4 in deliver_event /home/user/linux/tools/perf/builtin-top.c:1197:3
grate-driver#11 0x908a72 in do_flush /home/user/linux/tools/perf/util/ordered-events.c:244:9
grate-driver#12 0x905fae in __ordered_events__flush /home/user/linux/tools/perf/util/ordered-events.c:323:8
grate-driver#13 0x9058db in ordered_events__flush /home/user/linux/tools/perf/util/ordered-events.c:341:9
grate-driver#14 0x5f19b1 in process_thread /home/user/linux/tools/perf/builtin-top.c:1109:7
grate-driver#15 0x7f4f6a21a298 in start_thread /usr/src/debug/glibc-2.33-16.fc34.x86_64/nptl/pthread_create.c:481:8
grate-driver#16 0x7f4f697d0352 in clone ../sysdeps/unix/sysv/linux/x86_64/clone.S:95
0x61300009add6 is located 10 bytes to the right of 332-byte region [0x61300009ac80,0x61300009adcc)
allocated by thread T6 here:
#0 0x4f3f7f in malloc (/home/user/linux/tools/perf/perf+0x4f3f7f)
#1 0x7f4f6a0a88d9 (/lib64/libelf.so.1+0xa8d9)
Thread T6 created by T0 here:
#0 0x464856 in pthread_create (/home/user/linux/tools/perf/perf+0x464856)
#1 0x5f06e0 in __cmd_top /home/user/linux/tools/perf/builtin-top.c:1309:6
#2 0x5ef19f in cmd_top /home/user/linux/tools/perf/builtin-top.c:1762:11
#3 0x7b28c0 in run_builtin /home/user/linux/tools/perf/perf.c:313:11
#4 0x7b119f in handle_internal_command /home/user/linux/tools/perf/perf.c:365:8
#5 0x7b2423 in run_argv /home/user/linux/tools/perf/perf.c:409:2
#6 0x7b0c19 in main /home/user/linux/tools/perf/perf.c:539:3
#7 0x7f4f696f7b74 in __libc_start_main /usr/src/debug/glibc-2.33-16.fc34.x86_64/csu/../csu/libc-start.c:332:16
SUMMARY: AddressSanitizer: heap-buffer-overflow (/home/user/linux/tools/perf/perf+0x49875b) in StrstrCheck(void*, char*, char const*, char const*)
Shadow bytes around the buggy address:
0x0c268000b560: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c268000b570: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c268000b580: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c268000b590: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0c268000b5a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
=>0x0c268000b5b0: 00 00 00 00 00 00 00 00 00 04[fa]fa fa fa fa fa
0x0c268000b5c0: fa fa fa fa fa fa fa fa 00 00 00 00 00 00 00 00
0x0c268000b5d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0c268000b5e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0c268000b5f0: 07 fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c268000b600: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
Shadow byte legend (one shadow byte represents 8 application bytes):
Addressable: 00
Partially addressable: 01 02 03 04 05 06 07
Heap left redzone: fa
Freed heap region: fd
Stack left redzone: f1
Stack mid redzone: f2
Stack right redzone: f3
Stack after return: f5
Stack use after scope: f8
Global redzone: f9
Global init order: f6
Poisoned by user: f7
Container overflow: fc
Array cookie: ac
Intra object redzone: bb
ASan internal: fe
Left alloca redzone: ca
Right alloca redzone: cb
Shadow gap: cc
==363148==ABORTING
Suggested-by: Jiri Slaby <[email protected]>
Signed-off-by: Riccardo Mancini <[email protected]>
Acked-by: Namhyung Kim <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Fabian Hemmer <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Jiri Slaby <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Remi Bernon <[email protected]>
Link: http://lore.kernel.org/lkml/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
okias
pushed a commit
that referenced
this pull request
Jul 30, 2021
We got the following lockdep splat while running xfstests (specifically btrfs/003 and btrfs/020 in a row) with the new rc. This was uncovered by 87579e9 ("loop: use worker per cgroup instead of kworker") which converted loop to using workqueues, which comes with lockdep annotations that don't exist with kworkers. The lockdep splat is as follows ====================================================== WARNING: possible circular locking dependency detected 5.14.0-rc2-custom+ grate-driver#34 Not tainted ------------------------------------------------------ losetup/156417 is trying to acquire lock: ffff9c7645b02d38 ((wq_completion)loop0){+.+.}-{0:0}, at: flush_workqueue+0x84/0x600 but task is already holding lock: ffff9c7647395468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x650 [loop] which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #5 (&lo->lo_mutex){+.+.}-{3:3}: __mutex_lock+0xba/0x7c0 lo_open+0x28/0x60 [loop] blkdev_get_whole+0x28/0xf0 blkdev_get_by_dev.part.0+0x168/0x3c0 blkdev_open+0xd2/0xe0 do_dentry_open+0x163/0x3a0 path_openat+0x74d/0xa40 do_filp_open+0x9c/0x140 do_sys_openat2+0xb1/0x170 __x64_sys_openat+0x54/0x90 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #4 (&disk->open_mutex){+.+.}-{3:3}: __mutex_lock+0xba/0x7c0 blkdev_get_by_dev.part.0+0xd1/0x3c0 blkdev_get_by_path+0xc0/0xd0 btrfs_scan_one_device+0x52/0x1f0 [btrfs] btrfs_control_ioctl+0xac/0x170 [btrfs] __x64_sys_ioctl+0x83/0xb0 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #3 (uuid_mutex){+.+.}-{3:3}: __mutex_lock+0xba/0x7c0 btrfs_rm_device+0x48/0x6a0 [btrfs] btrfs_ioctl+0x2d1c/0x3110 [btrfs] __x64_sys_ioctl+0x83/0xb0 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #2 (sb_writers#11){.+.+}-{0:0}: lo_write_bvec+0x112/0x290 [loop] loop_process_work+0x25f/0xcb0 [loop] process_one_work+0x28f/0x5d0 worker_thread+0x55/0x3c0 kthread+0x140/0x170 ret_from_fork+0x22/0x30 -> #1 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}: process_one_work+0x266/0x5d0 worker_thread+0x55/0x3c0 kthread+0x140/0x170 ret_from_fork+0x22/0x30 -> #0 ((wq_completion)loop0){+.+.}-{0:0}: __lock_acquire+0x1130/0x1dc0 lock_acquire+0xf5/0x320 flush_workqueue+0xae/0x600 drain_workqueue+0xa0/0x110 destroy_workqueue+0x36/0x250 __loop_clr_fd+0x9a/0x650 [loop] lo_ioctl+0x29d/0x780 [loop] block_ioctl+0x3f/0x50 __x64_sys_ioctl+0x83/0xb0 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae other info that might help us debug this: Chain exists of: (wq_completion)loop0 --> &disk->open_mutex --> &lo->lo_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&lo->lo_mutex); lock(&disk->open_mutex); lock(&lo->lo_mutex); lock((wq_completion)loop0); *** DEADLOCK *** 1 lock held by losetup/156417: #0: ffff9c7647395468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x650 [loop] stack backtrace: CPU: 8 PID: 156417 Comm: losetup Not tainted 5.14.0-rc2-custom+ grate-driver#34 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 Call Trace: dump_stack_lvl+0x57/0x72 check_noncircular+0x10a/0x120 __lock_acquire+0x1130/0x1dc0 lock_acquire+0xf5/0x320 ? flush_workqueue+0x84/0x600 flush_workqueue+0xae/0x600 ? flush_workqueue+0x84/0x600 drain_workqueue+0xa0/0x110 destroy_workqueue+0x36/0x250 __loop_clr_fd+0x9a/0x650 [loop] lo_ioctl+0x29d/0x780 [loop] ? __lock_acquire+0x3a0/0x1dc0 ? update_dl_rq_load_avg+0x152/0x360 ? lock_is_held_type+0xa5/0x120 ? find_held_lock.constprop.0+0x2b/0x80 block_ioctl+0x3f/0x50 __x64_sys_ioctl+0x83/0xb0 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f645884de6b Usually the uuid_mutex exists to protect the fs_devices that map together all of the devices that match a specific uuid. In rm_device we're messing with the uuid of a device, so it makes sense to protect that here. However in doing that it pulls in a whole host of lockdep dependencies, as we call mnt_may_write() on the sb before we grab the uuid_mutex, thus we end up with the dependency chain under the uuid_mutex being added under the normal sb write dependency chain, which causes problems with loop devices. We don't need the uuid mutex here however. If we call btrfs_scan_one_device() before we scratch the super block we will find the fs_devices and not find the device itself and return EBUSY because the fs_devices is open. If we call it after the scratch happens it will not appear to be a valid btrfs file system. We do not need to worry about other fs_devices modifying operations here because we're protected by the exclusive operations locking. So drop the uuid_mutex here in order to fix the lockdep splat. Signed-off-by: Josef Bacik <[email protected]> Signed-off-by: David Sterba <[email protected]>
okias
pushed a commit
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Jul 30, 2021
For device removal and replace we call btrfs_find_device_by_devspec,
which if we give it a device path and nothing else will call
btrfs_find_device_by_path, which opens the block device and reads the
super block and then looks up our device based on that.
However this is completely unnecessary because we have the path stored
in our device on our fsdevices. All we need to do if we're given a path
is look through the fs_devices on our file system and use that device if
we find it, reading the super block is just silly.
This fixes the case where we end up with our sb write "lock" getting the
dependency of the block device ->open_mutex, which resulted in the
following lockdep splat
======================================================
WARNING: possible circular locking dependency detected
5.14.0-rc2+ #405 Not tainted
------------------------------------------------------
losetup/11576 is trying to acquire lock:
ffff9bbe8cded938 ((wq_completion)loop0){+.+.}-{0:0}, at: flush_workqueue+0x67/0x5e0
but task is already holding lock:
ffff9bbe88e4fc68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop]
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #4 (&lo->lo_mutex){+.+.}-{3:3}:
__mutex_lock+0x7d/0x750
lo_open+0x28/0x60 [loop]
blkdev_get_whole+0x25/0xf0
blkdev_get_by_dev.part.0+0x168/0x3c0
blkdev_open+0xd2/0xe0
do_dentry_open+0x161/0x390
path_openat+0x3cc/0xa20
do_filp_open+0x96/0x120
do_sys_openat2+0x7b/0x130
__x64_sys_openat+0x46/0x70
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
-> #3 (&disk->open_mutex){+.+.}-{3:3}:
__mutex_lock+0x7d/0x750
blkdev_get_by_dev.part.0+0x56/0x3c0
blkdev_get_by_path+0x98/0xa0
btrfs_get_bdev_and_sb+0x1b/0xb0
btrfs_find_device_by_devspec+0x12b/0x1c0
btrfs_rm_device+0x127/0x610
btrfs_ioctl+0x2a31/0x2e70
__x64_sys_ioctl+0x80/0xb0
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
-> #2 (sb_writers#12){.+.+}-{0:0}:
lo_write_bvec+0xc2/0x240 [loop]
loop_process_work+0x238/0xd00 [loop]
process_one_work+0x26b/0x560
worker_thread+0x55/0x3c0
kthread+0x140/0x160
ret_from_fork+0x1f/0x30
-> #1 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}:
process_one_work+0x245/0x560
worker_thread+0x55/0x3c0
kthread+0x140/0x160
ret_from_fork+0x1f/0x30
-> #0 ((wq_completion)loop0){+.+.}-{0:0}:
__lock_acquire+0x10ea/0x1d90
lock_acquire+0xb5/0x2b0
flush_workqueue+0x91/0x5e0
drain_workqueue+0xa0/0x110
destroy_workqueue+0x36/0x250
__loop_clr_fd+0x9a/0x660 [loop]
block_ioctl+0x3f/0x50
__x64_sys_ioctl+0x80/0xb0
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
other info that might help us debug this:
Chain exists of:
(wq_completion)loop0 --> &disk->open_mutex --> &lo->lo_mutex
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&lo->lo_mutex);
lock(&disk->open_mutex);
lock(&lo->lo_mutex);
lock((wq_completion)loop0);
*** DEADLOCK ***
1 lock held by losetup/11576:
#0: ffff9bbe88e4fc68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop]
stack backtrace:
CPU: 0 PID: 11576 Comm: losetup Not tainted 5.14.0-rc2+ #405
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014
Call Trace:
dump_stack_lvl+0x57/0x72
check_noncircular+0xcf/0xf0
? stack_trace_save+0x3b/0x50
__lock_acquire+0x10ea/0x1d90
lock_acquire+0xb5/0x2b0
? flush_workqueue+0x67/0x5e0
? lockdep_init_map_type+0x47/0x220
flush_workqueue+0x91/0x5e0
? flush_workqueue+0x67/0x5e0
? verify_cpu+0xf0/0x100
drain_workqueue+0xa0/0x110
destroy_workqueue+0x36/0x250
__loop_clr_fd+0x9a/0x660 [loop]
? blkdev_ioctl+0x8d/0x2a0
block_ioctl+0x3f/0x50
__x64_sys_ioctl+0x80/0xb0
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f31b02404cb
Signed-off-by: Josef Bacik <[email protected]>
Signed-off-by: David Sterba <[email protected]>
okias
pushed a commit
that referenced
this pull request
Jul 30, 2021
We update the ctime/mtime of a block device when we remove it so that
blkid knows the device changed. However we do this by re-opening the
block device and calling filp_update_time. This is more correct because
it'll call the inode->i_op->update_time if it exists, but the block dev
inodes do not do this. Instead call generic_update_time() on the
bd_inode in order to avoid the blkdev_open path and get rid of the
following lockdep splat
======================================================
WARNING: possible circular locking dependency detected
5.14.0-rc2+ #406 Not tainted
------------------------------------------------------
losetup/11596 is trying to acquire lock:
ffff939640d2f538 ((wq_completion)loop0){+.+.}-{0:0}, at: flush_workqueue+0x67/0x5e0
but task is already holding lock:
ffff939655510c68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop]
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #4 (&lo->lo_mutex){+.+.}-{3:3}:
__mutex_lock+0x7d/0x750
lo_open+0x28/0x60 [loop]
blkdev_get_whole+0x25/0xf0
blkdev_get_by_dev.part.0+0x168/0x3c0
blkdev_open+0xd2/0xe0
do_dentry_open+0x161/0x390
path_openat+0x3cc/0xa20
do_filp_open+0x96/0x120
do_sys_openat2+0x7b/0x130
__x64_sys_openat+0x46/0x70
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
-> #3 (&disk->open_mutex){+.+.}-{3:3}:
__mutex_lock+0x7d/0x750
blkdev_get_by_dev.part.0+0x56/0x3c0
blkdev_open+0xd2/0xe0
do_dentry_open+0x161/0x390
path_openat+0x3cc/0xa20
do_filp_open+0x96/0x120
file_open_name+0xc7/0x170
filp_open+0x2c/0x50
btrfs_scratch_superblocks.part.0+0x10f/0x170
btrfs_rm_device.cold+0xe8/0xed
btrfs_ioctl+0x2a31/0x2e70
__x64_sys_ioctl+0x80/0xb0
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
-> #2 (sb_writers#12){.+.+}-{0:0}:
lo_write_bvec+0xc2/0x240 [loop]
loop_process_work+0x238/0xd00 [loop]
process_one_work+0x26b/0x560
worker_thread+0x55/0x3c0
kthread+0x140/0x160
ret_from_fork+0x1f/0x30
-> #1 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}:
process_one_work+0x245/0x560
worker_thread+0x55/0x3c0
kthread+0x140/0x160
ret_from_fork+0x1f/0x30
-> #0 ((wq_completion)loop0){+.+.}-{0:0}:
__lock_acquire+0x10ea/0x1d90
lock_acquire+0xb5/0x2b0
flush_workqueue+0x91/0x5e0
drain_workqueue+0xa0/0x110
destroy_workqueue+0x36/0x250
__loop_clr_fd+0x9a/0x660 [loop]
block_ioctl+0x3f/0x50
__x64_sys_ioctl+0x80/0xb0
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
other info that might help us debug this:
Chain exists of:
(wq_completion)loop0 --> &disk->open_mutex --> &lo->lo_mutex
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&lo->lo_mutex);
lock(&disk->open_mutex);
lock(&lo->lo_mutex);
lock((wq_completion)loop0);
*** DEADLOCK ***
1 lock held by losetup/11596:
#0: ffff939655510c68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop]
stack backtrace:
CPU: 1 PID: 11596 Comm: losetup Not tainted 5.14.0-rc2+ #406
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014
Call Trace:
dump_stack_lvl+0x57/0x72
check_noncircular+0xcf/0xf0
? stack_trace_save+0x3b/0x50
__lock_acquire+0x10ea/0x1d90
lock_acquire+0xb5/0x2b0
? flush_workqueue+0x67/0x5e0
? lockdep_init_map_type+0x47/0x220
flush_workqueue+0x91/0x5e0
? flush_workqueue+0x67/0x5e0
? verify_cpu+0xf0/0x100
drain_workqueue+0xa0/0x110
destroy_workqueue+0x36/0x250
__loop_clr_fd+0x9a/0x660 [loop]
? blkdev_ioctl+0x8d/0x2a0
block_ioctl+0x3f/0x50
__x64_sys_ioctl+0x80/0xb0
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
Signed-off-by: Josef Bacik <[email protected]>
Signed-off-by: David Sterba <[email protected]>
okias
pushed a commit
that referenced
this pull request
Jul 30, 2021
When removing the device we call blkdev_put() on the device once we've
removed it, and because we have an EXCL open we need to take the
->open_mutex on the block device to clean it up. Unfortunately during
device remove we are holding the sb writers lock, which results in the
following lockdep splat
======================================================
WARNING: possible circular locking dependency detected
5.14.0-rc2+ #407 Not tainted
------------------------------------------------------
losetup/11595 is trying to acquire lock:
ffff973ac35dd138 ((wq_completion)loop0){+.+.}-{0:0}, at: flush_workqueue+0x67/0x5e0
but task is already holding lock:
ffff973ac9812c68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop]
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #4 (&lo->lo_mutex){+.+.}-{3:3}:
__mutex_lock+0x7d/0x750
lo_open+0x28/0x60 [loop]
blkdev_get_whole+0x25/0xf0
blkdev_get_by_dev.part.0+0x168/0x3c0
blkdev_open+0xd2/0xe0
do_dentry_open+0x161/0x390
path_openat+0x3cc/0xa20
do_filp_open+0x96/0x120
do_sys_openat2+0x7b/0x130
__x64_sys_openat+0x46/0x70
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
-> #3 (&disk->open_mutex){+.+.}-{3:3}:
__mutex_lock+0x7d/0x750
blkdev_put+0x3a/0x220
btrfs_rm_device.cold+0x62/0xe5
btrfs_ioctl+0x2a31/0x2e70
__x64_sys_ioctl+0x80/0xb0
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
-> #2 (sb_writers#12){.+.+}-{0:0}:
lo_write_bvec+0xc2/0x240 [loop]
loop_process_work+0x238/0xd00 [loop]
process_one_work+0x26b/0x560
worker_thread+0x55/0x3c0
kthread+0x140/0x160
ret_from_fork+0x1f/0x30
-> #1 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}:
process_one_work+0x245/0x560
worker_thread+0x55/0x3c0
kthread+0x140/0x160
ret_from_fork+0x1f/0x30
-> #0 ((wq_completion)loop0){+.+.}-{0:0}:
__lock_acquire+0x10ea/0x1d90
lock_acquire+0xb5/0x2b0
flush_workqueue+0x91/0x5e0
drain_workqueue+0xa0/0x110
destroy_workqueue+0x36/0x250
__loop_clr_fd+0x9a/0x660 [loop]
block_ioctl+0x3f/0x50
__x64_sys_ioctl+0x80/0xb0
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
other info that might help us debug this:
Chain exists of:
(wq_completion)loop0 --> &disk->open_mutex --> &lo->lo_mutex
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&lo->lo_mutex);
lock(&disk->open_mutex);
lock(&lo->lo_mutex);
lock((wq_completion)loop0);
*** DEADLOCK ***
1 lock held by losetup/11595:
#0: ffff973ac9812c68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop]
stack backtrace:
CPU: 0 PID: 11595 Comm: losetup Not tainted 5.14.0-rc2+ #407
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014
Call Trace:
dump_stack_lvl+0x57/0x72
check_noncircular+0xcf/0xf0
? stack_trace_save+0x3b/0x50
__lock_acquire+0x10ea/0x1d90
lock_acquire+0xb5/0x2b0
? flush_workqueue+0x67/0x5e0
? lockdep_init_map_type+0x47/0x220
flush_workqueue+0x91/0x5e0
? flush_workqueue+0x67/0x5e0
? verify_cpu+0xf0/0x100
drain_workqueue+0xa0/0x110
destroy_workqueue+0x36/0x250
__loop_clr_fd+0x9a/0x660 [loop]
? blkdev_ioctl+0x8d/0x2a0
block_ioctl+0x3f/0x50
__x64_sys_ioctl+0x80/0xb0
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fc21255d4cb
So instead save the bdev and do the put once we've dropped the sb
writers lock in order to avoid the lockdep recursion.
Signed-off-by: Josef Bacik <[email protected]>
Signed-off-by: David Sterba <[email protected]>
okias
pushed a commit
that referenced
this pull request
Aug 11, 2021
[ Upstream commit 2c48441 ] lz4 compatible decompressor is simple. The format is underspecified and relies on EOF notification to determine when to stop. Initramfs buffer format[1] explicitly states that it can have arbitrary number of zero padding. Thus when operating without a fill function, be extra careful to ensure that sizes less than 4, or apperantly empty chunksizes are treated as EOF. To test this I have created two cpio initrds, first a normal one, main.cpio. And second one with just a single /test-file with content "second" second.cpio. Then i compressed both of them with gzip, and with lz4 -l. Then I created a padding of 4 bytes (dd if=/dev/zero of=pad4 bs=1 count=4). To create four testcase initrds: 1) main.cpio.gzip + extra.cpio.gzip = pad0.gzip 2) main.cpio.lz4 + extra.cpio.lz4 = pad0.lz4 3) main.cpio.gzip + pad4 + extra.cpio.gzip = pad4.gzip 4) main.cpio.lz4 + pad4 + extra.cpio.lz4 = pad4.lz4 The pad4 test-cases replicate the initrd load by grub, as it pads and aligns every initrd it loads. All of the above boot, however /test-file was not accessible in the initrd for the testcase #4, as decoding in lz4 decompressor failed. Also an error message printed which usually is harmless. Whith a patched kernel, all of the above testcases now pass, and /test-file is accessible. This fixes lz4 initrd decompress warning on every boot with grub. And more importantly this fixes inability to load multiple lz4 compressed initrds with grub. This patch has been shipping in Ubuntu kernels since January 2021. [1] ./Documentation/driver-api/early-userspace/buffer-format.rst BugLink: https://bugs.launchpad.net/bugs/1835660 Link: https://lore.kernel.org/lkml/[email protected]/ # v0 Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Dimitri John Ledkov <[email protected]> Cc: Kyungsik Lee <[email protected]> Cc: Yinghai Lu <[email protected]> Cc: Bongkyu Kim <[email protected]> Cc: Kees Cook <[email protected]> Cc: Sven Schmidt <[email protected]> Cc: Rajat Asthana <[email protected]> Cc: Nick Terrell <[email protected]> Cc: Gao Xiang <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
okias
pushed a commit
that referenced
this pull request
Aug 19, 2021
We got the following lockdep splat while running xfstests (specifically btrfs/003 and btrfs/020 in a row) with the new rc. This was uncovered by 87579e9 ("loop: use worker per cgroup instead of kworker") which converted loop to using workqueues, which comes with lockdep annotations that don't exist with kworkers. The lockdep splat is as follows ====================================================== WARNING: possible circular locking dependency detected 5.14.0-rc2-custom+ grate-driver#34 Not tainted ------------------------------------------------------ losetup/156417 is trying to acquire lock: ffff9c7645b02d38 ((wq_completion)loop0){+.+.}-{0:0}, at: flush_workqueue+0x84/0x600 but task is already holding lock: ffff9c7647395468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x650 [loop] which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #5 (&lo->lo_mutex){+.+.}-{3:3}: __mutex_lock+0xba/0x7c0 lo_open+0x28/0x60 [loop] blkdev_get_whole+0x28/0xf0 blkdev_get_by_dev.part.0+0x168/0x3c0 blkdev_open+0xd2/0xe0 do_dentry_open+0x163/0x3a0 path_openat+0x74d/0xa40 do_filp_open+0x9c/0x140 do_sys_openat2+0xb1/0x170 __x64_sys_openat+0x54/0x90 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #4 (&disk->open_mutex){+.+.}-{3:3}: __mutex_lock+0xba/0x7c0 blkdev_get_by_dev.part.0+0xd1/0x3c0 blkdev_get_by_path+0xc0/0xd0 btrfs_scan_one_device+0x52/0x1f0 [btrfs] btrfs_control_ioctl+0xac/0x170 [btrfs] __x64_sys_ioctl+0x83/0xb0 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #3 (uuid_mutex){+.+.}-{3:3}: __mutex_lock+0xba/0x7c0 btrfs_rm_device+0x48/0x6a0 [btrfs] btrfs_ioctl+0x2d1c/0x3110 [btrfs] __x64_sys_ioctl+0x83/0xb0 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #2 (sb_writers#11){.+.+}-{0:0}: lo_write_bvec+0x112/0x290 [loop] loop_process_work+0x25f/0xcb0 [loop] process_one_work+0x28f/0x5d0 worker_thread+0x55/0x3c0 kthread+0x140/0x170 ret_from_fork+0x22/0x30 -> #1 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}: process_one_work+0x266/0x5d0 worker_thread+0x55/0x3c0 kthread+0x140/0x170 ret_from_fork+0x22/0x30 -> #0 ((wq_completion)loop0){+.+.}-{0:0}: __lock_acquire+0x1130/0x1dc0 lock_acquire+0xf5/0x320 flush_workqueue+0xae/0x600 drain_workqueue+0xa0/0x110 destroy_workqueue+0x36/0x250 __loop_clr_fd+0x9a/0x650 [loop] lo_ioctl+0x29d/0x780 [loop] block_ioctl+0x3f/0x50 __x64_sys_ioctl+0x83/0xb0 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae other info that might help us debug this: Chain exists of: (wq_completion)loop0 --> &disk->open_mutex --> &lo->lo_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&lo->lo_mutex); lock(&disk->open_mutex); lock(&lo->lo_mutex); lock((wq_completion)loop0); *** DEADLOCK *** 1 lock held by losetup/156417: #0: ffff9c7647395468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x650 [loop] stack backtrace: CPU: 8 PID: 156417 Comm: losetup Not tainted 5.14.0-rc2-custom+ grate-driver#34 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 Call Trace: dump_stack_lvl+0x57/0x72 check_noncircular+0x10a/0x120 __lock_acquire+0x1130/0x1dc0 lock_acquire+0xf5/0x320 ? flush_workqueue+0x84/0x600 flush_workqueue+0xae/0x600 ? flush_workqueue+0x84/0x600 drain_workqueue+0xa0/0x110 destroy_workqueue+0x36/0x250 __loop_clr_fd+0x9a/0x650 [loop] lo_ioctl+0x29d/0x780 [loop] ? __lock_acquire+0x3a0/0x1dc0 ? update_dl_rq_load_avg+0x152/0x360 ? lock_is_held_type+0xa5/0x120 ? find_held_lock.constprop.0+0x2b/0x80 block_ioctl+0x3f/0x50 __x64_sys_ioctl+0x83/0xb0 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f645884de6b Usually the uuid_mutex exists to protect the fs_devices that map together all of the devices that match a specific uuid. In rm_device we're messing with the uuid of a device, so it makes sense to protect that here. However in doing that it pulls in a whole host of lockdep dependencies, as we call mnt_may_write() on the sb before we grab the uuid_mutex, thus we end up with the dependency chain under the uuid_mutex being added under the normal sb write dependency chain, which causes problems with loop devices. We don't need the uuid mutex here however. If we call btrfs_scan_one_device() before we scratch the super block we will find the fs_devices and not find the device itself and return EBUSY because the fs_devices is open. If we call it after the scratch happens it will not appear to be a valid btrfs file system. We do not need to worry about other fs_devices modifying operations here because we're protected by the exclusive operations locking. So drop the uuid_mutex here in order to fix the lockdep splat. Signed-off-by: Josef Bacik <[email protected]> Signed-off-by: David Sterba <[email protected]>
okias
pushed a commit
that referenced
this pull request
Aug 19, 2021
For device removal and replace we call btrfs_find_device_by_devspec,
which if we give it a device path and nothing else will call
btrfs_find_device_by_path, which opens the block device and reads the
super block and then looks up our device based on that.
However this is completely unnecessary because we have the path stored
in our device on our fsdevices. All we need to do if we're given a path
is look through the fs_devices on our file system and use that device if
we find it, reading the super block is just silly.
This fixes the case where we end up with our sb write "lock" getting the
dependency of the block device ->open_mutex, which resulted in the
following lockdep splat
======================================================
WARNING: possible circular locking dependency detected
5.14.0-rc2+ #405 Not tainted
------------------------------------------------------
losetup/11576 is trying to acquire lock:
ffff9bbe8cded938 ((wq_completion)loop0){+.+.}-{0:0}, at: flush_workqueue+0x67/0x5e0
but task is already holding lock:
ffff9bbe88e4fc68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop]
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #4 (&lo->lo_mutex){+.+.}-{3:3}:
__mutex_lock+0x7d/0x750
lo_open+0x28/0x60 [loop]
blkdev_get_whole+0x25/0xf0
blkdev_get_by_dev.part.0+0x168/0x3c0
blkdev_open+0xd2/0xe0
do_dentry_open+0x161/0x390
path_openat+0x3cc/0xa20
do_filp_open+0x96/0x120
do_sys_openat2+0x7b/0x130
__x64_sys_openat+0x46/0x70
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
-> #3 (&disk->open_mutex){+.+.}-{3:3}:
__mutex_lock+0x7d/0x750
blkdev_get_by_dev.part.0+0x56/0x3c0
blkdev_get_by_path+0x98/0xa0
btrfs_get_bdev_and_sb+0x1b/0xb0
btrfs_find_device_by_devspec+0x12b/0x1c0
btrfs_rm_device+0x127/0x610
btrfs_ioctl+0x2a31/0x2e70
__x64_sys_ioctl+0x80/0xb0
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
-> #2 (sb_writers#12){.+.+}-{0:0}:
lo_write_bvec+0xc2/0x240 [loop]
loop_process_work+0x238/0xd00 [loop]
process_one_work+0x26b/0x560
worker_thread+0x55/0x3c0
kthread+0x140/0x160
ret_from_fork+0x1f/0x30
-> #1 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}:
process_one_work+0x245/0x560
worker_thread+0x55/0x3c0
kthread+0x140/0x160
ret_from_fork+0x1f/0x30
-> #0 ((wq_completion)loop0){+.+.}-{0:0}:
__lock_acquire+0x10ea/0x1d90
lock_acquire+0xb5/0x2b0
flush_workqueue+0x91/0x5e0
drain_workqueue+0xa0/0x110
destroy_workqueue+0x36/0x250
__loop_clr_fd+0x9a/0x660 [loop]
block_ioctl+0x3f/0x50
__x64_sys_ioctl+0x80/0xb0
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
other info that might help us debug this:
Chain exists of:
(wq_completion)loop0 --> &disk->open_mutex --> &lo->lo_mutex
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&lo->lo_mutex);
lock(&disk->open_mutex);
lock(&lo->lo_mutex);
lock((wq_completion)loop0);
*** DEADLOCK ***
1 lock held by losetup/11576:
#0: ffff9bbe88e4fc68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop]
stack backtrace:
CPU: 0 PID: 11576 Comm: losetup Not tainted 5.14.0-rc2+ #405
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014
Call Trace:
dump_stack_lvl+0x57/0x72
check_noncircular+0xcf/0xf0
? stack_trace_save+0x3b/0x50
__lock_acquire+0x10ea/0x1d90
lock_acquire+0xb5/0x2b0
? flush_workqueue+0x67/0x5e0
? lockdep_init_map_type+0x47/0x220
flush_workqueue+0x91/0x5e0
? flush_workqueue+0x67/0x5e0
? verify_cpu+0xf0/0x100
drain_workqueue+0xa0/0x110
destroy_workqueue+0x36/0x250
__loop_clr_fd+0x9a/0x660 [loop]
? blkdev_ioctl+0x8d/0x2a0
block_ioctl+0x3f/0x50
__x64_sys_ioctl+0x80/0xb0
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f31b02404cb
Signed-off-by: Josef Bacik <[email protected]>
Signed-off-by: David Sterba <[email protected]>
okias
pushed a commit
that referenced
this pull request
Aug 19, 2021
We update the ctime/mtime of a block device when we remove it so that
blkid knows the device changed. However we do this by re-opening the
block device and calling filp_update_time. This is more correct because
it'll call the inode->i_op->update_time if it exists, but the block dev
inodes do not do this. Instead call generic_update_time() on the
bd_inode in order to avoid the blkdev_open path and get rid of the
following lockdep splat
======================================================
WARNING: possible circular locking dependency detected
5.14.0-rc2+ #406 Not tainted
------------------------------------------------------
losetup/11596 is trying to acquire lock:
ffff939640d2f538 ((wq_completion)loop0){+.+.}-{0:0}, at: flush_workqueue+0x67/0x5e0
but task is already holding lock:
ffff939655510c68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop]
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #4 (&lo->lo_mutex){+.+.}-{3:3}:
__mutex_lock+0x7d/0x750
lo_open+0x28/0x60 [loop]
blkdev_get_whole+0x25/0xf0
blkdev_get_by_dev.part.0+0x168/0x3c0
blkdev_open+0xd2/0xe0
do_dentry_open+0x161/0x390
path_openat+0x3cc/0xa20
do_filp_open+0x96/0x120
do_sys_openat2+0x7b/0x130
__x64_sys_openat+0x46/0x70
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
-> #3 (&disk->open_mutex){+.+.}-{3:3}:
__mutex_lock+0x7d/0x750
blkdev_get_by_dev.part.0+0x56/0x3c0
blkdev_open+0xd2/0xe0
do_dentry_open+0x161/0x390
path_openat+0x3cc/0xa20
do_filp_open+0x96/0x120
file_open_name+0xc7/0x170
filp_open+0x2c/0x50
btrfs_scratch_superblocks.part.0+0x10f/0x170
btrfs_rm_device.cold+0xe8/0xed
btrfs_ioctl+0x2a31/0x2e70
__x64_sys_ioctl+0x80/0xb0
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
-> #2 (sb_writers#12){.+.+}-{0:0}:
lo_write_bvec+0xc2/0x240 [loop]
loop_process_work+0x238/0xd00 [loop]
process_one_work+0x26b/0x560
worker_thread+0x55/0x3c0
kthread+0x140/0x160
ret_from_fork+0x1f/0x30
-> #1 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}:
process_one_work+0x245/0x560
worker_thread+0x55/0x3c0
kthread+0x140/0x160
ret_from_fork+0x1f/0x30
-> #0 ((wq_completion)loop0){+.+.}-{0:0}:
__lock_acquire+0x10ea/0x1d90
lock_acquire+0xb5/0x2b0
flush_workqueue+0x91/0x5e0
drain_workqueue+0xa0/0x110
destroy_workqueue+0x36/0x250
__loop_clr_fd+0x9a/0x660 [loop]
block_ioctl+0x3f/0x50
__x64_sys_ioctl+0x80/0xb0
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
other info that might help us debug this:
Chain exists of:
(wq_completion)loop0 --> &disk->open_mutex --> &lo->lo_mutex
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&lo->lo_mutex);
lock(&disk->open_mutex);
lock(&lo->lo_mutex);
lock((wq_completion)loop0);
*** DEADLOCK ***
1 lock held by losetup/11596:
#0: ffff939655510c68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop]
stack backtrace:
CPU: 1 PID: 11596 Comm: losetup Not tainted 5.14.0-rc2+ #406
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014
Call Trace:
dump_stack_lvl+0x57/0x72
check_noncircular+0xcf/0xf0
? stack_trace_save+0x3b/0x50
__lock_acquire+0x10ea/0x1d90
lock_acquire+0xb5/0x2b0
? flush_workqueue+0x67/0x5e0
? lockdep_init_map_type+0x47/0x220
flush_workqueue+0x91/0x5e0
? flush_workqueue+0x67/0x5e0
? verify_cpu+0xf0/0x100
drain_workqueue+0xa0/0x110
destroy_workqueue+0x36/0x250
__loop_clr_fd+0x9a/0x660 [loop]
? blkdev_ioctl+0x8d/0x2a0
block_ioctl+0x3f/0x50
__x64_sys_ioctl+0x80/0xb0
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
Signed-off-by: Josef Bacik <[email protected]>
Signed-off-by: David Sterba <[email protected]>
okias
pushed a commit
that referenced
this pull request
Aug 19, 2021
When removing the device we call blkdev_put() on the device once we've
removed it, and because we have an EXCL open we need to take the
->open_mutex on the block device to clean it up. Unfortunately during
device remove we are holding the sb writers lock, which results in the
following lockdep splat
======================================================
WARNING: possible circular locking dependency detected
5.14.0-rc2+ #407 Not tainted
------------------------------------------------------
losetup/11595 is trying to acquire lock:
ffff973ac35dd138 ((wq_completion)loop0){+.+.}-{0:0}, at: flush_workqueue+0x67/0x5e0
but task is already holding lock:
ffff973ac9812c68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop]
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #4 (&lo->lo_mutex){+.+.}-{3:3}:
__mutex_lock+0x7d/0x750
lo_open+0x28/0x60 [loop]
blkdev_get_whole+0x25/0xf0
blkdev_get_by_dev.part.0+0x168/0x3c0
blkdev_open+0xd2/0xe0
do_dentry_open+0x161/0x390
path_openat+0x3cc/0xa20
do_filp_open+0x96/0x120
do_sys_openat2+0x7b/0x130
__x64_sys_openat+0x46/0x70
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
-> #3 (&disk->open_mutex){+.+.}-{3:3}:
__mutex_lock+0x7d/0x750
blkdev_put+0x3a/0x220
btrfs_rm_device.cold+0x62/0xe5
btrfs_ioctl+0x2a31/0x2e70
__x64_sys_ioctl+0x80/0xb0
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
-> #2 (sb_writers#12){.+.+}-{0:0}:
lo_write_bvec+0xc2/0x240 [loop]
loop_process_work+0x238/0xd00 [loop]
process_one_work+0x26b/0x560
worker_thread+0x55/0x3c0
kthread+0x140/0x160
ret_from_fork+0x1f/0x30
-> #1 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}:
process_one_work+0x245/0x560
worker_thread+0x55/0x3c0
kthread+0x140/0x160
ret_from_fork+0x1f/0x30
-> #0 ((wq_completion)loop0){+.+.}-{0:0}:
__lock_acquire+0x10ea/0x1d90
lock_acquire+0xb5/0x2b0
flush_workqueue+0x91/0x5e0
drain_workqueue+0xa0/0x110
destroy_workqueue+0x36/0x250
__loop_clr_fd+0x9a/0x660 [loop]
block_ioctl+0x3f/0x50
__x64_sys_ioctl+0x80/0xb0
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
other info that might help us debug this:
Chain exists of:
(wq_completion)loop0 --> &disk->open_mutex --> &lo->lo_mutex
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&lo->lo_mutex);
lock(&disk->open_mutex);
lock(&lo->lo_mutex);
lock((wq_completion)loop0);
*** DEADLOCK ***
1 lock held by losetup/11595:
#0: ffff973ac9812c68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop]
stack backtrace:
CPU: 0 PID: 11595 Comm: losetup Not tainted 5.14.0-rc2+ #407
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014
Call Trace:
dump_stack_lvl+0x57/0x72
check_noncircular+0xcf/0xf0
? stack_trace_save+0x3b/0x50
__lock_acquire+0x10ea/0x1d90
lock_acquire+0xb5/0x2b0
? flush_workqueue+0x67/0x5e0
? lockdep_init_map_type+0x47/0x220
flush_workqueue+0x91/0x5e0
? flush_workqueue+0x67/0x5e0
? verify_cpu+0xf0/0x100
drain_workqueue+0xa0/0x110
destroy_workqueue+0x36/0x250
__loop_clr_fd+0x9a/0x660 [loop]
? blkdev_ioctl+0x8d/0x2a0
block_ioctl+0x3f/0x50
__x64_sys_ioctl+0x80/0xb0
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fc21255d4cb
So instead save the bdev and do the put once we've dropped the sb
writers lock in order to avoid the lockdep recursion.
Signed-off-by: Josef Bacik <[email protected]>
Signed-off-by: David Sterba <[email protected]>
okias
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[ Upstream commit 2c48441 ] lz4 compatible decompressor is simple. The format is underspecified and relies on EOF notification to determine when to stop. Initramfs buffer format[1] explicitly states that it can have arbitrary number of zero padding. Thus when operating without a fill function, be extra careful to ensure that sizes less than 4, or apperantly empty chunksizes are treated as EOF. To test this I have created two cpio initrds, first a normal one, main.cpio. And second one with just a single /test-file with content "second" second.cpio. Then i compressed both of them with gzip, and with lz4 -l. Then I created a padding of 4 bytes (dd if=/dev/zero of=pad4 bs=1 count=4). To create four testcase initrds: 1) main.cpio.gzip + extra.cpio.gzip = pad0.gzip 2) main.cpio.lz4 + extra.cpio.lz4 = pad0.lz4 3) main.cpio.gzip + pad4 + extra.cpio.gzip = pad4.gzip 4) main.cpio.lz4 + pad4 + extra.cpio.lz4 = pad4.lz4 The pad4 test-cases replicate the initrd load by grub, as it pads and aligns every initrd it loads. All of the above boot, however /test-file was not accessible in the initrd for the testcase #4, as decoding in lz4 decompressor failed. Also an error message printed which usually is harmless. Whith a patched kernel, all of the above testcases now pass, and /test-file is accessible. This fixes lz4 initrd decompress warning on every boot with grub. And more importantly this fixes inability to load multiple lz4 compressed initrds with grub. This patch has been shipping in Ubuntu kernels since January 2021. [1] ./Documentation/driver-api/early-userspace/buffer-format.rst BugLink: https://bugs.launchpad.net/bugs/1835660 Link: https://lore.kernel.org/lkml/[email protected]/ # v0 Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Dimitri John Ledkov <[email protected]> Cc: Kyungsik Lee <[email protected]> Cc: Yinghai Lu <[email protected]> Cc: Bongkyu Kim <[email protected]> Cc: Kees Cook <[email protected]> Cc: Sven Schmidt <[email protected]> Cc: Rajat Asthana <[email protected]> Cc: Nick Terrell <[email protected]> Cc: Gao Xiang <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
okias
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commit 4385539 upstream. The ordering of MSI-X enable in hardware is dysfunctional: 1) MSI-X is disabled in the control register 2) Various setup functions 3) pci_msi_setup_msi_irqs() is invoked which ends up accessing the MSI-X table entries 4) MSI-X is enabled and masked in the control register with the comment that enabling is required for some hardware to access the MSI-X table Step #4 obviously contradicts #3. The history of this is an issue with the NIU hardware. When #4 was introduced the table access actually happened in msix_program_entries() which was invoked after enabling and masking MSI-X. This was changed in commit d71d643 ("PCI/MSI: Kill redundant call of irq_set_msi_desc() for MSI-X interrupts") which removed the table write from msix_program_entries(). Interestingly enough nobody noticed and either NIU still works or it did not get any testing with a kernel 3.19 or later. Nevertheless this is inconsistent and there is no reason why MSI-X can't be enabled and masked in the control register early on, i.e. move step #4 above to step #1. This preserves the NIU workaround and has no side effects on other hardware. Fixes: d71d643 ("PCI/MSI: Kill redundant call of irq_set_msi_desc() for MSI-X interrupts") Signed-off-by: Thomas Gleixner <[email protected]> Tested-by: Marc Zyngier <[email protected]> Reviewed-by: Ashok Raj <[email protected]> Reviewed-by: Marc Zyngier <[email protected]> Acked-by: Bjorn Helgaas <[email protected]> Cc: [email protected] Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
okias
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commit 4385539 upstream. The ordering of MSI-X enable in hardware is dysfunctional: 1) MSI-X is disabled in the control register 2) Various setup functions 3) pci_msi_setup_msi_irqs() is invoked which ends up accessing the MSI-X table entries 4) MSI-X is enabled and masked in the control register with the comment that enabling is required for some hardware to access the MSI-X table Step #4 obviously contradicts #3. The history of this is an issue with the NIU hardware. When #4 was introduced the table access actually happened in msix_program_entries() which was invoked after enabling and masking MSI-X. This was changed in commit d71d643 ("PCI/MSI: Kill redundant call of irq_set_msi_desc() for MSI-X interrupts") which removed the table write from msix_program_entries(). Interestingly enough nobody noticed and either NIU still works or it did not get any testing with a kernel 3.19 or later. Nevertheless this is inconsistent and there is no reason why MSI-X can't be enabled and masked in the control register early on, i.e. move step #4 above to step #1. This preserves the NIU workaround and has no side effects on other hardware. Fixes: d71d643 ("PCI/MSI: Kill redundant call of irq_set_msi_desc() for MSI-X interrupts") Signed-off-by: Thomas Gleixner <[email protected]> Tested-by: Marc Zyngier <[email protected]> Reviewed-by: Ashok Raj <[email protected]> Reviewed-by: Marc Zyngier <[email protected]> Acked-by: Bjorn Helgaas <[email protected]> Cc: [email protected] Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
okias
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[ Upstream commit 2c48441 ] lz4 compatible decompressor is simple. The format is underspecified and relies on EOF notification to determine when to stop. Initramfs buffer format[1] explicitly states that it can have arbitrary number of zero padding. Thus when operating without a fill function, be extra careful to ensure that sizes less than 4, or apperantly empty chunksizes are treated as EOF. To test this I have created two cpio initrds, first a normal one, main.cpio. And second one with just a single /test-file with content "second" second.cpio. Then i compressed both of them with gzip, and with lz4 -l. Then I created a padding of 4 bytes (dd if=/dev/zero of=pad4 bs=1 count=4). To create four testcase initrds: 1) main.cpio.gzip + extra.cpio.gzip = pad0.gzip 2) main.cpio.lz4 + extra.cpio.lz4 = pad0.lz4 3) main.cpio.gzip + pad4 + extra.cpio.gzip = pad4.gzip 4) main.cpio.lz4 + pad4 + extra.cpio.lz4 = pad4.lz4 The pad4 test-cases replicate the initrd load by grub, as it pads and aligns every initrd it loads. All of the above boot, however /test-file was not accessible in the initrd for the testcase #4, as decoding in lz4 decompressor failed. Also an error message printed which usually is harmless. Whith a patched kernel, all of the above testcases now pass, and /test-file is accessible. This fixes lz4 initrd decompress warning on every boot with grub. And more importantly this fixes inability to load multiple lz4 compressed initrds with grub. This patch has been shipping in Ubuntu kernels since January 2021. [1] ./Documentation/driver-api/early-userspace/buffer-format.rst BugLink: https://bugs.launchpad.net/bugs/1835660 Link: https://lore.kernel.org/lkml/[email protected]/ # v0 Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Dimitri John Ledkov <[email protected]> Cc: Kyungsik Lee <[email protected]> Cc: Yinghai Lu <[email protected]> Cc: Bongkyu Kim <[email protected]> Cc: Kees Cook <[email protected]> Cc: Sven Schmidt <[email protected]> Cc: Rajat Asthana <[email protected]> Cc: Nick Terrell <[email protected]> Cc: Gao Xiang <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
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commit 4d14c5c upstream Calling btrfs_qgroup_reserve_meta_prealloc from btrfs_delayed_inode_reserve_metadata can result in flushing delalloc while holding a transaction and delayed node locks. This is deadlock prone. In the past multiple commits: * ae5e070 ("btrfs: qgroup: don't try to wait flushing if we're already holding a transaction") * 6f23277 ("btrfs: qgroup: don't commit transaction when we already hold the handle") Tried to solve various aspects of this but this was always a whack-a-mole game. Unfortunately those 2 fixes don't solve a deadlock scenario involving btrfs_delayed_node::mutex. Namely, one thread can call btrfs_dirty_inode as a result of reading a file and modifying its atime: PID: 6963 TASK: ffff8c7f3f94c000 CPU: 2 COMMAND: "test" #0 __schedule at ffffffffa529e07d #1 schedule at ffffffffa529e4ff #2 schedule_timeout at ffffffffa52a1bdd #3 wait_for_completion at ffffffffa529eeea <-- sleeps with delayed node mutex held #4 start_delalloc_inodes at ffffffffc0380db5 #5 btrfs_start_delalloc_snapshot at ffffffffc0393836 #6 try_flush_qgroup at ffffffffc03f04b2 #7 __btrfs_qgroup_reserve_meta at ffffffffc03f5bb6 <-- tries to reserve space and starts delalloc inodes. #8 btrfs_delayed_update_inode at ffffffffc03e31aa <-- acquires delayed node mutex grate-driver#9 btrfs_update_inode at ffffffffc0385ba8 grate-driver#10 btrfs_dirty_inode at ffffffffc038627b <-- TRANSACTIION OPENED grate-driver#11 touch_atime at ffffffffa4cf0000 grate-driver#12 generic_file_read_iter at ffffffffa4c1f123 grate-driver#13 new_sync_read at ffffffffa4ccdc8a grate-driver#14 vfs_read at ffffffffa4cd0849 grate-driver#15 ksys_read at ffffffffa4cd0bd1 grate-driver#16 do_syscall_64 at ffffffffa4a052eb grate-driver#17 entry_SYSCALL_64_after_hwframe at ffffffffa540008c This will cause an asynchronous work to flush the delalloc inodes to happen which can try to acquire the same delayed_node mutex: PID: 455 TASK: ffff8c8085fa4000 CPU: 5 COMMAND: "kworker/u16:30" #0 __schedule at ffffffffa529e07d #1 schedule at ffffffffa529e4ff #2 schedule_preempt_disabled at ffffffffa529e80a #3 __mutex_lock at ffffffffa529fdcb <-- goes to sleep, never wakes up. #4 btrfs_delayed_update_inode at ffffffffc03e3143 <-- tries to acquire the mutex #5 btrfs_update_inode at ffffffffc0385ba8 <-- this is the same inode that pid 6963 is holding #6 cow_file_range_inline.constprop.78 at ffffffffc0386be7 #7 cow_file_range at ffffffffc03879c1 #8 btrfs_run_delalloc_range at ffffffffc038894c grate-driver#9 writepage_delalloc at ffffffffc03a3c8f grate-driver#10 __extent_writepage at ffffffffc03a4c01 grate-driver#11 extent_write_cache_pages at ffffffffc03a500b grate-driver#12 extent_writepages at ffffffffc03a6de2 grate-driver#13 do_writepages at ffffffffa4c277eb grate-driver#14 __filemap_fdatawrite_range at ffffffffa4c1e5bb grate-driver#15 btrfs_run_delalloc_work at ffffffffc0380987 <-- starts running delayed nodes grate-driver#16 normal_work_helper at ffffffffc03b706c grate-driver#17 process_one_work at ffffffffa4aba4e4 grate-driver#18 worker_thread at ffffffffa4aba6fd grate-driver#19 kthread at ffffffffa4ac0a3d grate-driver#20 ret_from_fork at ffffffffa54001ff To fully address those cases the complete fix is to never issue any flushing while holding the transaction or the delayed node lock. This patch achieves it by calling qgroup_reserve_meta directly which will either succeed without flushing or will fail and return -EDQUOT. In the latter case that return value is going to be propagated to btrfs_dirty_inode which will fallback to start a new transaction. That's fine as the majority of time we expect the inode will have BTRFS_DELAYED_NODE_INODE_DIRTY flag set which will result in directly copying the in-memory state. Fixes: c53e965 ("btrfs: qgroup: try to flush qgroup space when we get -EDQUOT") CC: [email protected] # 5.10+ Reviewed-by: Qu Wenruo <[email protected]> Signed-off-by: Nikolay Borisov <[email protected]> Signed-off-by: David Sterba <[email protected]> Signed-off-by: Anand Jain <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
okias
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commit 4385539 upstream. The ordering of MSI-X enable in hardware is dysfunctional: 1) MSI-X is disabled in the control register 2) Various setup functions 3) pci_msi_setup_msi_irqs() is invoked which ends up accessing the MSI-X table entries 4) MSI-X is enabled and masked in the control register with the comment that enabling is required for some hardware to access the MSI-X table Step #4 obviously contradicts #3. The history of this is an issue with the NIU hardware. When #4 was introduced the table access actually happened in msix_program_entries() which was invoked after enabling and masking MSI-X. This was changed in commit d71d643 ("PCI/MSI: Kill redundant call of irq_set_msi_desc() for MSI-X interrupts") which removed the table write from msix_program_entries(). Interestingly enough nobody noticed and either NIU still works or it did not get any testing with a kernel 3.19 or later. Nevertheless this is inconsistent and there is no reason why MSI-X can't be enabled and masked in the control register early on, i.e. move step #4 above to step #1. This preserves the NIU workaround and has no side effects on other hardware. Fixes: d71d643 ("PCI/MSI: Kill redundant call of irq_set_msi_desc() for MSI-X interrupts") Signed-off-by: Thomas Gleixner <[email protected]> Tested-by: Marc Zyngier <[email protected]> Reviewed-by: Ashok Raj <[email protected]> Reviewed-by: Marc Zyngier <[email protected]> Acked-by: Bjorn Helgaas <[email protected]> Cc: [email protected] Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
okias
pushed a commit
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Aug 19, 2021
[ Upstream commit 2c48441 ] lz4 compatible decompressor is simple. The format is underspecified and relies on EOF notification to determine when to stop. Initramfs buffer format[1] explicitly states that it can have arbitrary number of zero padding. Thus when operating without a fill function, be extra careful to ensure that sizes less than 4, or apperantly empty chunksizes are treated as EOF. To test this I have created two cpio initrds, first a normal one, main.cpio. And second one with just a single /test-file with content "second" second.cpio. Then i compressed both of them with gzip, and with lz4 -l. Then I created a padding of 4 bytes (dd if=/dev/zero of=pad4 bs=1 count=4). To create four testcase initrds: 1) main.cpio.gzip + extra.cpio.gzip = pad0.gzip 2) main.cpio.lz4 + extra.cpio.lz4 = pad0.lz4 3) main.cpio.gzip + pad4 + extra.cpio.gzip = pad4.gzip 4) main.cpio.lz4 + pad4 + extra.cpio.lz4 = pad4.lz4 The pad4 test-cases replicate the initrd load by grub, as it pads and aligns every initrd it loads. All of the above boot, however /test-file was not accessible in the initrd for the testcase #4, as decoding in lz4 decompressor failed. Also an error message printed which usually is harmless. Whith a patched kernel, all of the above testcases now pass, and /test-file is accessible. This fixes lz4 initrd decompress warning on every boot with grub. And more importantly this fixes inability to load multiple lz4 compressed initrds with grub. This patch has been shipping in Ubuntu kernels since January 2021. [1] ./Documentation/driver-api/early-userspace/buffer-format.rst BugLink: https://bugs.launchpad.net/bugs/1835660 Link: https://lore.kernel.org/lkml/[email protected]/ # v0 Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Dimitri John Ledkov <[email protected]> Cc: Kyungsik Lee <[email protected]> Cc: Yinghai Lu <[email protected]> Cc: Bongkyu Kim <[email protected]> Cc: Kees Cook <[email protected]> Cc: Sven Schmidt <[email protected]> Cc: Rajat Asthana <[email protected]> Cc: Nick Terrell <[email protected]> Cc: Gao Xiang <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
devbis
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Aug 24, 2021
The ordering of MSI-X enable in hardware is dysfunctional:
1) MSI-X is disabled in the control register
2) Various setup functions
3) pci_msi_setup_msi_irqs() is invoked which ends up accessing
the MSI-X table entries
4) MSI-X is enabled and masked in the control register with the
comment that enabling is required for some hardware to access
the MSI-X table
Step okias#4 obviously contradicts okias#3. The history of this is an issue with the
NIU hardware. When okias#4 was introduced the table access actually happened in
msix_program_entries() which was invoked after enabling and masking MSI-X.
This was changed in commit d71d643 ("PCI/MSI: Kill redundant call of
irq_set_msi_desc() for MSI-X interrupts") which removed the table write
from msix_program_entries().
Interestingly enough nobody noticed and either NIU still works or it did
not get any testing with a kernel 3.19 or later.
Nevertheless this is inconsistent and there is no reason why MSI-X can't be
enabled and masked in the control register early on, i.e. move step okias#4
above to step okias#1. This preserves the NIU workaround and has no side effects
on other hardware.
Fixes: d71d643 ("PCI/MSI: Kill redundant call of irq_set_msi_desc() for MSI-X interrupts")
Signed-off-by: Thomas Gleixner <[email protected]>
Tested-by: Marc Zyngier <[email protected]>
Reviewed-by: Ashok Raj <[email protected]>
Reviewed-by: Marc Zyngier <[email protected]>
Acked-by: Bjorn Helgaas <[email protected]>
Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]
devbis
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Aug 31, 2021
Fix crash on reboot on a system with ASIX AX88178 USB adapter attached to it: | asix 1-1.4:1.0 eth0: unregister 'asix' usb-ci_hdrc.0-1.4, ASIX AX88178 USB 2.0 Ethernet | 8<--- cut here --- | Unable to handle kernel NULL pointer dereference at virtual address 0000028c | pgd = 5ec93aee | [0000028c] *pgd=00000000 | Internal error: Oops: 5 [okias#1] PREEMPT SMP ARM | Modules linked in: | CPU: 1 PID: 1 Comm: systemd-shutdow Not tainted 5.14.0-rc1-20210811-1 okias#4 | Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree) | PC is at phy_disconnect+0x8/0x48 | LR is at ax88772_unbind+0x14/0x20 | [<80650d04>] (phy_disconnect) from [<80741aa4>] (ax88772_unbind+0x14/0x20) | [<80741aa4>] (ax88772_unbind) from [<8074e250>] (usbnet_disconnect+0x48/0xd8) | [<8074e250>] (usbnet_disconnect) from [<807655e0>] (usb_unbind_interface+0x78/0x25c) | [<807655e0>] (usb_unbind_interface) from [<805b03a0>] (__device_release_driver+0x154/0x20c) | [<805b03a0>] (__device_release_driver) from [<805b0478>] (device_release_driver+0x20/0x2c) | [<805b0478>] (device_release_driver) from [<805af944>] (bus_remove_device+0xcc/0xf8) | [<805af944>] (bus_remove_device) from [<805ab26c>] (device_del+0x178/0x4b0) | [<805ab26c>] (device_del) from [<807634a4>] (usb_disable_device+0xcc/0x178) | [<807634a4>] (usb_disable_device) from [<8075a060>] (usb_disconnect+0xd8/0x238) | [<8075a060>] (usb_disconnect) from [<8075a02c>] (usb_disconnect+0xa4/0x238) | [<8075a02c>] (usb_disconnect) from [<8075a02c>] (usb_disconnect+0xa4/0x238) | [<8075a02c>] (usb_disconnect) from [<80af3520>] (usb_remove_hcd+0xa0/0x198) | [<80af3520>] (usb_remove_hcd) from [<807902e0>] (host_stop+0x38/0xa8) | [<807902e0>] (host_stop) from [<8078d9e4>] (ci_hdrc_remove+0x3c/0x118) | [<8078d9e4>] (ci_hdrc_remove) from [<805b27ec>] (platform_remove+0x20/0x50) | [<805b27ec>] (platform_remove) from [<805b03a0>] (__device_release_driver+0x154/0x20c) | [<805b03a0>] (__device_release_driver) from [<805b0478>] (device_release_driver+0x20/0x2c) | [<805b0478>] (device_release_driver) from [<805af944>] (bus_remove_device+0xcc/0xf8) | [<805af944>] (bus_remove_device) from [<805ab26c>] (device_del+0x178/0x4b0) For this adapter we call ax88178_bind() and ax88772_unbind(), which is related to different chip version and different counter part *bind() function. Since this chip is currently not ported to the PHYLIB, we do not need to call phy_disconnect() here. So, to fix this crash, we need to add ax88178_unbind(). Fixes: e532a09 ("net: usb: asix: ax88772: add phylib support") Reported-by: Robin van der Gracht <[email protected]> Tested-by: Robin van der Gracht <[email protected]> Signed-off-by: Oleksij Rempel <[email protected]> Signed-off-by: David S. Miller <[email protected]>
devbis
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Aug 31, 2021
vctrl_enable() and vctrl_disable() call regulator_enable() and regulator_disable(), respectively. However, vctrl_* are regulator ops and should not be calling the locked regulator APIs. Doing so results in a lockdep warning. Instead of exporting more internal regulator ops, model the ctrl supply as an actual supply to vctrl-regulator. At probe time this driver still needs to use the consumer API to fetch its constraints, but otherwise lets the regulator core handle the upstream supply for it. The enable/disable/is_enabled ops are not removed, but now only track state internally. This preserves the original behavior with the ops being available, but one could argue that the original behavior was already incorrect: the internal state would not match the upstream supply if that supply had another consumer that enabled the supply, while vctrl-regulator was not enabled. The lockdep warning is as follows: WARNING: possible circular locking dependency detected 5.14.0-rc6 okias#2 Not tainted ------------------------------------------------------ swapper/0/1 is trying to acquire lock: ffffffc011306d00 (regulator_list_mutex){+.+.}-{3:3}, at: regulator_lock_dependent (arch/arm64/include/asm/current.h:19 include/linux/ww_mutex.h:111 drivers/regulator/core.c:329) but task is already holding lock: ffffff8004a77160 (regulator_ww_class_mutex){+.+.}-{3:3}, at: regulator_lock_recursive (drivers/regulator/core.c:156 drivers/regulator/core.c:263) which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> okias#2 (regulator_ww_class_mutex){+.+.}-{3:3}: __mutex_lock_common (include/asm-generic/atomic-instrumented.h:606 include/asm-generic/atomic-long.h:29 kernel/locking/mutex.c:103 kernel/locking/mutex.c:144 kernel/locking/mutex.c:963) ww_mutex_lock (kernel/locking/mutex.c:1199) regulator_lock_recursive (drivers/regulator/core.c:156 drivers/regulator/core.c:263) regulator_lock_dependent (drivers/regulator/core.c:343) regulator_enable (drivers/regulator/core.c:2808) set_machine_constraints (drivers/regulator/core.c:1536) regulator_register (drivers/regulator/core.c:5486) devm_regulator_register (drivers/regulator/devres.c:196) reg_fixed_voltage_probe (drivers/regulator/fixed.c:289) platform_probe (drivers/base/platform.c:1427) [...] -> okias#1 (regulator_ww_class_acquire){+.+.}-{0:0}: regulator_lock_dependent (include/linux/ww_mutex.h:129 drivers/regulator/core.c:329) regulator_enable (drivers/regulator/core.c:2808) set_machine_constraints (drivers/regulator/core.c:1536) regulator_register (drivers/regulator/core.c:5486) devm_regulator_register (drivers/regulator/devres.c:196) reg_fixed_voltage_probe (drivers/regulator/fixed.c:289) [...] -> #0 (regulator_list_mutex){+.+.}-{3:3}: __lock_acquire (kernel/locking/lockdep.c:3052 (discriminator 4) kernel/locking/lockdep.c:3174 (discriminator 4) kernel/locking/lockdep.c:3789 (discriminator 4) kernel/locking/lockdep.c:5015 (discriminator 4)) lock_acquire (arch/arm64/include/asm/percpu.h:39 kernel/locking/lockdep.c:438 kernel/locking/lockdep.c:5627) __mutex_lock_common (include/asm-generic/atomic-instrumented.h:606 include/asm-generic/atomic-long.h:29 kernel/locking/mutex.c:103 kernel/locking/mutex.c:144 kernel/locking/mutex.c:963) mutex_lock_nested (kernel/locking/mutex.c:1125) regulator_lock_dependent (arch/arm64/include/asm/current.h:19 include/linux/ww_mutex.h:111 drivers/regulator/core.c:329) regulator_enable (drivers/regulator/core.c:2808) vctrl_enable (drivers/regulator/vctrl-regulator.c:400) _regulator_do_enable (drivers/regulator/core.c:2617) _regulator_enable (drivers/regulator/core.c:2764) regulator_enable (drivers/regulator/core.c:308 drivers/regulator/core.c:2809) _set_opp (drivers/opp/core.c:819 drivers/opp/core.c:1072) dev_pm_opp_set_rate (drivers/opp/core.c:1164) set_target (drivers/cpufreq/cpufreq-dt.c:62) __cpufreq_driver_target (drivers/cpufreq/cpufreq.c:2216 drivers/cpufreq/cpufreq.c:2271) cpufreq_online (drivers/cpufreq/cpufreq.c:1488 (discriminator 2)) cpufreq_add_dev (drivers/cpufreq/cpufreq.c:1563) subsys_interface_register (drivers/base/bus.c:?) cpufreq_register_driver (drivers/cpufreq/cpufreq.c:2819) dt_cpufreq_probe (drivers/cpufreq/cpufreq-dt.c:344) [...] other info that might help us debug this: Chain exists of: regulator_list_mutex --> regulator_ww_class_acquire --> regulator_ww_class_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(regulator_ww_class_mutex); lock(regulator_ww_class_acquire); lock(regulator_ww_class_mutex); lock(regulator_list_mutex); *** DEADLOCK *** 6 locks held by swapper/0/1: #0: ffffff8002d32188 (&dev->mutex){....}-{3:3}, at: __device_driver_lock (drivers/base/dd.c:1030) okias#1: ffffffc0111a0520 (cpu_hotplug_lock){++++}-{0:0}, at: cpufreq_register_driver (drivers/cpufreq/cpufreq.c:2792 (discriminator 2)) okias#2: ffffff8002a8d918 (subsys mutex#9){+.+.}-{3:3}, at: subsys_interface_register (drivers/base/bus.c:1033) okias#3: ffffff800341bb90 (&policy->rwsem){+.+.}-{3:3}, at: cpufreq_online (include/linux/bitmap.h:285 include/linux/cpumask.h:405 drivers/cpufreq/cpufreq.c:1399) okias#4: ffffffc011f0b7b8 (regulator_ww_class_acquire){+.+.}-{0:0}, at: regulator_enable (drivers/regulator/core.c:2808) okias#5: ffffff8004a77160 (regulator_ww_class_mutex){+.+.}-{3:3}, at: regulator_lock_recursive (drivers/regulator/core.c:156 drivers/regulator/core.c:263) stack backtrace: CPU: 1 PID: 1 Comm: swapper/0 Not tainted 5.14.0-rc6 okias#2 7c8f8996d021ed0f65271e6aeebf7999de74a9fa Hardware name: Google Scarlet (DT) Call trace: dump_backtrace (arch/arm64/kernel/stacktrace.c:161) show_stack (arch/arm64/kernel/stacktrace.c:218) dump_stack_lvl (lib/dump_stack.c:106 (discriminator 2)) dump_stack (lib/dump_stack.c:113) print_circular_bug (kernel/locking/lockdep.c:?) check_noncircular (kernel/locking/lockdep.c:?) __lock_acquire (kernel/locking/lockdep.c:3052 (discriminator 4) kernel/locking/lockdep.c:3174 (discriminator 4) kernel/locking/lockdep.c:3789 (discriminator 4) kernel/locking/lockdep.c:5015 (discriminator 4)) lock_acquire (arch/arm64/include/asm/percpu.h:39 kernel/locking/lockdep.c:438 kernel/locking/lockdep.c:5627) __mutex_lock_common (include/asm-generic/atomic-instrumented.h:606 include/asm-generic/atomic-long.h:29 kernel/locking/mutex.c:103 kernel/locking/mutex.c:144 kernel/locking/mutex.c:963) mutex_lock_nested (kernel/locking/mutex.c:1125) regulator_lock_dependent (arch/arm64/include/asm/current.h:19 include/linux/ww_mutex.h:111 drivers/regulator/core.c:329) regulator_enable (drivers/regulator/core.c:2808) vctrl_enable (drivers/regulator/vctrl-regulator.c:400) _regulator_do_enable (drivers/regulator/core.c:2617) _regulator_enable (drivers/regulator/core.c:2764) regulator_enable (drivers/regulator/core.c:308 drivers/regulator/core.c:2809) _set_opp (drivers/opp/core.c:819 drivers/opp/core.c:1072) dev_pm_opp_set_rate (drivers/opp/core.c:1164) set_target (drivers/cpufreq/cpufreq-dt.c:62) __cpufreq_driver_target (drivers/cpufreq/cpufreq.c:2216 drivers/cpufreq/cpufreq.c:2271) cpufreq_online (drivers/cpufreq/cpufreq.c:1488 (discriminator 2)) cpufreq_add_dev (drivers/cpufreq/cpufreq.c:1563) subsys_interface_register (drivers/base/bus.c:?) cpufreq_register_driver (drivers/cpufreq/cpufreq.c:2819) dt_cpufreq_probe (drivers/cpufreq/cpufreq-dt.c:344) [...] Reported-by: Brian Norris <[email protected]> Fixes: f8702f9 ("regulator: core: Use ww_mutex for regulators locking") Fixes: e915331 ("regulator: vctrl-regulator: Avoid deadlock getting and setting the voltage") Signed-off-by: Chen-Yu Tsai <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Mark Brown <[email protected]>
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Sep 5, 2021
commit 67069a1 upstream. ASan reported a memory leak caused by info_linear not being deallocated. The info_linear was allocated during in perf_event__synthesize_one_bpf_prog(). This patch adds the corresponding free() when bpf_prog_info_node is freed in perf_env__purge_bpf(). $ sudo ./perf record -- sleep 5 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.025 MB perf.data (8 samples) ] ================================================================= ==297735==ERROR: LeakSanitizer: detected memory leaks Direct leak of 7688 byte(s) in 19 object(s) allocated from: #0 0x4f420f in malloc (/home/user/linux/tools/perf/perf+0x4f420f) #1 0xc06a74 in bpf_program__get_prog_info_linear /home/user/linux/tools/lib/bpf/libbpf.c:11113:16 #2 0xb426fe in perf_event__synthesize_one_bpf_prog /home/user/linux/tools/perf/util/bpf-event.c:191:16 #3 0xb42008 in perf_event__synthesize_bpf_events /home/user/linux/tools/perf/util/bpf-event.c:410:9 #4 0x594596 in record__synthesize /home/user/linux/tools/perf/builtin-record.c:1490:8 #5 0x58c9ac in __cmd_record /home/user/linux/tools/perf/builtin-record.c:1798:8 #6 0x58990b in cmd_record /home/user/linux/tools/perf/builtin-record.c:2901:8 #7 0x7b2a20 in run_builtin /home/user/linux/tools/perf/perf.c:313:11 #8 0x7b12ff in handle_internal_command /home/user/linux/tools/perf/perf.c:365:8 grate-driver#9 0x7b2583 in run_argv /home/user/linux/tools/perf/perf.c:409:2 grate-driver#10 0x7b0d79 in main /home/user/linux/tools/perf/perf.c:539:3 grate-driver#11 0x7fa357ef6b74 in __libc_start_main /usr/src/debug/glibc-2.33-8.fc34.x86_64/csu/../csu/libc-start.c:332:16 Signed-off-by: Riccardo Mancini <[email protected]> Acked-by: Ian Rogers <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Alexei Starovoitov <[email protected]> Cc: Andrii Nakryiko <[email protected]> Cc: Daniel Borkmann <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: John Fastabend <[email protected]> Cc: KP Singh <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Martin KaFai Lau <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Song Liu <[email protected]> Cc: Yonghong Song <[email protected]> Link: http://lore.kernel.org/lkml/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]> Signed-off-by: Hanjun Guo <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
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Sep 5, 2021
commit 41d5854 upstream. I got several memory leak reports from Asan with a simple command. It was because VDSO is not released due to the refcount. Like in __dsos_addnew_id(), it should put the refcount after adding to the list. $ perf record true [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.030 MB perf.data (10 samples) ] ================================================================= ==692599==ERROR: LeakSanitizer: detected memory leaks Direct leak of 439 byte(s) in 1 object(s) allocated from: #0 0x7fea52341037 in __interceptor_calloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:154 #1 0x559bce4aa8ee in dso__new_id util/dso.c:1256 #2 0x559bce59245a in __machine__addnew_vdso util/vdso.c:132 #3 0x559bce59245a in machine__findnew_vdso util/vdso.c:347 #4 0x559bce50826c in map__new util/map.c:175 #5 0x559bce503c92 in machine__process_mmap2_event util/machine.c:1787 #6 0x559bce512f6b in machines__deliver_event util/session.c:1481 #7 0x559bce515107 in perf_session__deliver_event util/session.c:1551 #8 0x559bce51d4d2 in do_flush util/ordered-events.c:244 grate-driver#9 0x559bce51d4d2 in __ordered_events__flush util/ordered-events.c:323 grate-driver#10 0x559bce519bea in __perf_session__process_events util/session.c:2268 grate-driver#11 0x559bce519bea in perf_session__process_events util/session.c:2297 grate-driver#12 0x559bce2e7a52 in process_buildids /home/namhyung/project/linux/tools/perf/builtin-record.c:1017 grate-driver#13 0x559bce2e7a52 in record__finish_output /home/namhyung/project/linux/tools/perf/builtin-record.c:1234 grate-driver#14 0x559bce2ed4f6 in __cmd_record /home/namhyung/project/linux/tools/perf/builtin-record.c:2026 grate-driver#15 0x559bce2ed4f6 in cmd_record /home/namhyung/project/linux/tools/perf/builtin-record.c:2858 grate-driver#16 0x559bce422db4 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313 grate-driver#17 0x559bce2acac8 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365 grate-driver#18 0x559bce2acac8 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409 grate-driver#19 0x559bce2acac8 in main /home/namhyung/project/linux/tools/perf/perf.c:539 grate-driver#20 0x7fea51e76d09 in __libc_start_main ../csu/libc-start.c:308 Indirect leak of 32 byte(s) in 1 object(s) allocated from: #0 0x7fea52341037 in __interceptor_calloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:154 #1 0x559bce520907 in nsinfo__copy util/namespaces.c:169 #2 0x559bce50821b in map__new util/map.c:168 #3 0x559bce503c92 in machine__process_mmap2_event util/machine.c:1787 #4 0x559bce512f6b in machines__deliver_event util/session.c:1481 #5 0x559bce515107 in perf_session__deliver_event util/session.c:1551 #6 0x559bce51d4d2 in do_flush util/ordered-events.c:244 #7 0x559bce51d4d2 in __ordered_events__flush util/ordered-events.c:323 #8 0x559bce519bea in __perf_session__process_events util/session.c:2268 grate-driver#9 0x559bce519bea in perf_session__process_events util/session.c:2297 grate-driver#10 0x559bce2e7a52 in process_buildids /home/namhyung/project/linux/tools/perf/builtin-record.c:1017 grate-driver#11 0x559bce2e7a52 in record__finish_output /home/namhyung/project/linux/tools/perf/builtin-record.c:1234 grate-driver#12 0x559bce2ed4f6 in __cmd_record /home/namhyung/project/linux/tools/perf/builtin-record.c:2026 grate-driver#13 0x559bce2ed4f6 in cmd_record /home/namhyung/project/linux/tools/perf/builtin-record.c:2858 grate-driver#14 0x559bce422db4 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313 grate-driver#15 0x559bce2acac8 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365 grate-driver#16 0x559bce2acac8 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409 grate-driver#17 0x559bce2acac8 in main /home/namhyung/project/linux/tools/perf/perf.c:539 grate-driver#18 0x7fea51e76d09 in __libc_start_main ../csu/libc-start.c:308 SUMMARY: AddressSanitizer: 471 byte(s) leaked in 2 allocation(s). Signed-off-by: Namhyung Kim <[email protected]> Acked-by: Jiri Olsa <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Andi Kleen <[email protected]> Cc: Ian Rogers <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Peter Zijlstra <[email protected]> Link: http://lore.kernel.org/lkml/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]> Signed-off-by: Hanjun Guo <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
okias
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Sep 8, 2021
We update the ctime/mtime of a block device when we remove it so that
blkid knows the device changed. However we do this by re-opening the
block device and calling filp_update_time. This is more correct because
it'll call the inode->i_op->update_time if it exists, but the block dev
inodes do not do this. Instead call generic_update_time() on the
bd_inode in order to avoid the blkdev_open path and get rid of the
following lockdep splat:
======================================================
WARNING: possible circular locking dependency detected
5.14.0-rc2+ #406 Not tainted
------------------------------------------------------
losetup/11596 is trying to acquire lock:
ffff939640d2f538 ((wq_completion)loop0){+.+.}-{0:0}, at: flush_workqueue+0x67/0x5e0
but task is already holding lock:
ffff939655510c68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop]
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #4 (&lo->lo_mutex){+.+.}-{3:3}:
__mutex_lock+0x7d/0x750
lo_open+0x28/0x60 [loop]
blkdev_get_whole+0x25/0xf0
blkdev_get_by_dev.part.0+0x168/0x3c0
blkdev_open+0xd2/0xe0
do_dentry_open+0x161/0x390
path_openat+0x3cc/0xa20
do_filp_open+0x96/0x120
do_sys_openat2+0x7b/0x130
__x64_sys_openat+0x46/0x70
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
-> #3 (&disk->open_mutex){+.+.}-{3:3}:
__mutex_lock+0x7d/0x750
blkdev_get_by_dev.part.0+0x56/0x3c0
blkdev_open+0xd2/0xe0
do_dentry_open+0x161/0x390
path_openat+0x3cc/0xa20
do_filp_open+0x96/0x120
file_open_name+0xc7/0x170
filp_open+0x2c/0x50
btrfs_scratch_superblocks.part.0+0x10f/0x170
btrfs_rm_device.cold+0xe8/0xed
btrfs_ioctl+0x2a31/0x2e70
__x64_sys_ioctl+0x80/0xb0
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
-> #2 (sb_writers#12){.+.+}-{0:0}:
lo_write_bvec+0xc2/0x240 [loop]
loop_process_work+0x238/0xd00 [loop]
process_one_work+0x26b/0x560
worker_thread+0x55/0x3c0
kthread+0x140/0x160
ret_from_fork+0x1f/0x30
-> #1 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}:
process_one_work+0x245/0x560
worker_thread+0x55/0x3c0
kthread+0x140/0x160
ret_from_fork+0x1f/0x30
-> #0 ((wq_completion)loop0){+.+.}-{0:0}:
__lock_acquire+0x10ea/0x1d90
lock_acquire+0xb5/0x2b0
flush_workqueue+0x91/0x5e0
drain_workqueue+0xa0/0x110
destroy_workqueue+0x36/0x250
__loop_clr_fd+0x9a/0x660 [loop]
block_ioctl+0x3f/0x50
__x64_sys_ioctl+0x80/0xb0
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
other info that might help us debug this:
Chain exists of:
(wq_completion)loop0 --> &disk->open_mutex --> &lo->lo_mutex
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&lo->lo_mutex);
lock(&disk->open_mutex);
lock(&lo->lo_mutex);
lock((wq_completion)loop0);
*** DEADLOCK ***
1 lock held by losetup/11596:
#0: ffff939655510c68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop]
stack backtrace:
CPU: 1 PID: 11596 Comm: losetup Not tainted 5.14.0-rc2+ #406
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014
Call Trace:
dump_stack_lvl+0x57/0x72
check_noncircular+0xcf/0xf0
? stack_trace_save+0x3b/0x50
__lock_acquire+0x10ea/0x1d90
lock_acquire+0xb5/0x2b0
? flush_workqueue+0x67/0x5e0
? lockdep_init_map_type+0x47/0x220
flush_workqueue+0x91/0x5e0
? flush_workqueue+0x67/0x5e0
? verify_cpu+0xf0/0x100
drain_workqueue+0xa0/0x110
destroy_workqueue+0x36/0x250
__loop_clr_fd+0x9a/0x660 [loop]
? blkdev_ioctl+0x8d/0x2a0
block_ioctl+0x3f/0x50
__x64_sys_ioctl+0x80/0xb0
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
Reviewed-by: Anand Jain <[email protected]>
Signed-off-by: Josef Bacik <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>
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Sep 8, 2021
When removing the device we call blkdev_put() on the device once we've
removed it, and because we have an EXCL open we need to take the
->open_mutex on the block device to clean it up. Unfortunately during
device remove we are holding the sb writers lock, which results in the
following lockdep splat:
======================================================
WARNING: possible circular locking dependency detected
5.14.0-rc2+ #407 Not tainted
------------------------------------------------------
losetup/11595 is trying to acquire lock:
ffff973ac35dd138 ((wq_completion)loop0){+.+.}-{0:0}, at: flush_workqueue+0x67/0x5e0
but task is already holding lock:
ffff973ac9812c68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop]
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #4 (&lo->lo_mutex){+.+.}-{3:3}:
__mutex_lock+0x7d/0x750
lo_open+0x28/0x60 [loop]
blkdev_get_whole+0x25/0xf0
blkdev_get_by_dev.part.0+0x168/0x3c0
blkdev_open+0xd2/0xe0
do_dentry_open+0x161/0x390
path_openat+0x3cc/0xa20
do_filp_open+0x96/0x120
do_sys_openat2+0x7b/0x130
__x64_sys_openat+0x46/0x70
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
-> #3 (&disk->open_mutex){+.+.}-{3:3}:
__mutex_lock+0x7d/0x750
blkdev_put+0x3a/0x220
btrfs_rm_device.cold+0x62/0xe5
btrfs_ioctl+0x2a31/0x2e70
__x64_sys_ioctl+0x80/0xb0
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
-> #2 (sb_writers#12){.+.+}-{0:0}:
lo_write_bvec+0xc2/0x240 [loop]
loop_process_work+0x238/0xd00 [loop]
process_one_work+0x26b/0x560
worker_thread+0x55/0x3c0
kthread+0x140/0x160
ret_from_fork+0x1f/0x30
-> #1 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}:
process_one_work+0x245/0x560
worker_thread+0x55/0x3c0
kthread+0x140/0x160
ret_from_fork+0x1f/0x30
-> #0 ((wq_completion)loop0){+.+.}-{0:0}:
__lock_acquire+0x10ea/0x1d90
lock_acquire+0xb5/0x2b0
flush_workqueue+0x91/0x5e0
drain_workqueue+0xa0/0x110
destroy_workqueue+0x36/0x250
__loop_clr_fd+0x9a/0x660 [loop]
block_ioctl+0x3f/0x50
__x64_sys_ioctl+0x80/0xb0
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
other info that might help us debug this:
Chain exists of:
(wq_completion)loop0 --> &disk->open_mutex --> &lo->lo_mutex
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&lo->lo_mutex);
lock(&disk->open_mutex);
lock(&lo->lo_mutex);
lock((wq_completion)loop0);
*** DEADLOCK ***
1 lock held by losetup/11595:
#0: ffff973ac9812c68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop]
stack backtrace:
CPU: 0 PID: 11595 Comm: losetup Not tainted 5.14.0-rc2+ #407
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014
Call Trace:
dump_stack_lvl+0x57/0x72
check_noncircular+0xcf/0xf0
? stack_trace_save+0x3b/0x50
__lock_acquire+0x10ea/0x1d90
lock_acquire+0xb5/0x2b0
? flush_workqueue+0x67/0x5e0
? lockdep_init_map_type+0x47/0x220
flush_workqueue+0x91/0x5e0
? flush_workqueue+0x67/0x5e0
? verify_cpu+0xf0/0x100
drain_workqueue+0xa0/0x110
destroy_workqueue+0x36/0x250
__loop_clr_fd+0x9a/0x660 [loop]
? blkdev_ioctl+0x8d/0x2a0
block_ioctl+0x3f/0x50
__x64_sys_ioctl+0x80/0xb0
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fc21255d4cb
So instead save the bdev and do the put once we've dropped the sb
writers lock in order to avoid the lockdep recursion.
Reviewed-by: Anand Jain <[email protected]>
Signed-off-by: Josef Bacik <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>
okias
pushed a commit
that referenced
this pull request
Sep 8, 2021
If CONFIG_BLK_DEV_LOOP && CONFIG_MTD (at least; there might be other
combinations), lockdep complains circular locking dependency at
__loop_clr_fd(), for major_names_lock serves as a locking dependency
aggregating hub across multiple block modules.
======================================================
WARNING: possible circular locking dependency detected
5.14.0+ #757 Tainted: G E
------------------------------------------------------
systemd-udevd/7568 is trying to acquire lock:
ffff88800f334d48 ((wq_completion)loop0){+.+.}-{0:0}, at: flush_workqueue+0x70/0x560
but task is already holding lock:
ffff888014a7d4a0 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x4d/0x400 [loop]
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #6 (&lo->lo_mutex){+.+.}-{3:3}:
lock_acquire+0xbe/0x1f0
__mutex_lock_common+0xb6/0xe10
mutex_lock_killable_nested+0x17/0x20
lo_open+0x23/0x50 [loop]
blkdev_get_by_dev+0x199/0x540
blkdev_open+0x58/0x90
do_dentry_open+0x144/0x3a0
path_openat+0xa57/0xda0
do_filp_open+0x9f/0x140
do_sys_openat2+0x71/0x150
__x64_sys_openat+0x78/0xa0
do_syscall_64+0x3d/0xb0
entry_SYSCALL_64_after_hwframe+0x44/0xae
-> #5 (&disk->open_mutex){+.+.}-{3:3}:
lock_acquire+0xbe/0x1f0
__mutex_lock_common+0xb6/0xe10
mutex_lock_nested+0x17/0x20
bd_register_pending_holders+0x20/0x100
device_add_disk+0x1ae/0x390
loop_add+0x29c/0x2d0 [loop]
blk_request_module+0x5a/0xb0
blkdev_get_no_open+0x27/0xa0
blkdev_get_by_dev+0x5f/0x540
blkdev_open+0x58/0x90
do_dentry_open+0x144/0x3a0
path_openat+0xa57/0xda0
do_filp_open+0x9f/0x140
do_sys_openat2+0x71/0x150
__x64_sys_openat+0x78/0xa0
do_syscall_64+0x3d/0xb0
entry_SYSCALL_64_after_hwframe+0x44/0xae
-> #4 (major_names_lock){+.+.}-{3:3}:
lock_acquire+0xbe/0x1f0
__mutex_lock_common+0xb6/0xe10
mutex_lock_nested+0x17/0x20
blkdev_show+0x19/0x80
devinfo_show+0x52/0x60
seq_read_iter+0x2d5/0x3e0
proc_reg_read_iter+0x41/0x80
vfs_read+0x2ac/0x330
ksys_read+0x6b/0xd0
do_syscall_64+0x3d/0xb0
entry_SYSCALL_64_after_hwframe+0x44/0xae
-> #3 (&p->lock){+.+.}-{3:3}:
lock_acquire+0xbe/0x1f0
__mutex_lock_common+0xb6/0xe10
mutex_lock_nested+0x17/0x20
seq_read_iter+0x37/0x3e0
generic_file_splice_read+0xf3/0x170
splice_direct_to_actor+0x14e/0x350
do_splice_direct+0x84/0xd0
do_sendfile+0x263/0x430
__se_sys_sendfile64+0x96/0xc0
do_syscall_64+0x3d/0xb0
entry_SYSCALL_64_after_hwframe+0x44/0xae
-> #2 (sb_writers#3){.+.+}-{0:0}:
lock_acquire+0xbe/0x1f0
lo_write_bvec+0x96/0x280 [loop]
loop_process_work+0xa68/0xc10 [loop]
process_one_work+0x293/0x480
worker_thread+0x23d/0x4b0
kthread+0x163/0x180
ret_from_fork+0x1f/0x30
-> #1 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}:
lock_acquire+0xbe/0x1f0
process_one_work+0x280/0x480
worker_thread+0x23d/0x4b0
kthread+0x163/0x180
ret_from_fork+0x1f/0x30
-> #0 ((wq_completion)loop0){+.+.}-{0:0}:
validate_chain+0x1f0d/0x33e0
__lock_acquire+0x92d/0x1030
lock_acquire+0xbe/0x1f0
flush_workqueue+0x8c/0x560
drain_workqueue+0x80/0x140
destroy_workqueue+0x47/0x4f0
__loop_clr_fd+0xb4/0x400 [loop]
blkdev_put+0x14a/0x1d0
blkdev_close+0x1c/0x20
__fput+0xfd/0x220
task_work_run+0x69/0xc0
exit_to_user_mode_prepare+0x1ce/0x1f0
syscall_exit_to_user_mode+0x26/0x60
do_syscall_64+0x4c/0xb0
entry_SYSCALL_64_after_hwframe+0x44/0xae
other info that might help us debug this:
Chain exists of:
(wq_completion)loop0 --> &disk->open_mutex --> &lo->lo_mutex
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&lo->lo_mutex);
lock(&disk->open_mutex);
lock(&lo->lo_mutex);
lock((wq_completion)loop0);
*** DEADLOCK ***
2 locks held by systemd-udevd/7568:
#0: ffff888012554128 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0x4c/0x1d0
#1: ffff888014a7d4a0 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x4d/0x400 [loop]
stack backtrace:
CPU: 0 PID: 7568 Comm: systemd-udevd Tainted: G E 5.14.0+ #757
Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 02/27/2020
Call Trace:
dump_stack_lvl+0x79/0xbf
print_circular_bug+0x5d6/0x5e0
? stack_trace_save+0x42/0x60
? save_trace+0x3d/0x2d0
check_noncircular+0x10b/0x120
validate_chain+0x1f0d/0x33e0
? __lock_acquire+0x953/0x1030
? __lock_acquire+0x953/0x1030
__lock_acquire+0x92d/0x1030
? flush_workqueue+0x70/0x560
lock_acquire+0xbe/0x1f0
? flush_workqueue+0x70/0x560
flush_workqueue+0x8c/0x560
? flush_workqueue+0x70/0x560
? sched_clock_cpu+0xe/0x1a0
? drain_workqueue+0x41/0x140
drain_workqueue+0x80/0x140
destroy_workqueue+0x47/0x4f0
? blk_mq_freeze_queue_wait+0xac/0xd0
__loop_clr_fd+0xb4/0x400 [loop]
? __mutex_unlock_slowpath+0x35/0x230
blkdev_put+0x14a/0x1d0
blkdev_close+0x1c/0x20
__fput+0xfd/0x220
task_work_run+0x69/0xc0
exit_to_user_mode_prepare+0x1ce/0x1f0
syscall_exit_to_user_mode+0x26/0x60
do_syscall_64+0x4c/0xb0
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f0fd4c661f7
Code: 00 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 41 c3 48 83 ec 18 89 7c 24 0c e8 13 fc ff ff
RSP: 002b:00007ffd1c9e9fd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 00007f0fd46be6c8 RCX: 00007f0fd4c661f7
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000006
RBP: 0000000000000006 R08: 000055fff1eaf400 R09: 0000000000000000
R10: 00007f0fd46be6c8 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000002f08 R15: 00007ffd1c9ea050
Commit 1c500ad ("loop: reduce the loop_ctl_mutex scope") is for
breaking "loop_ctl_mutex => &lo->lo_mutex" dependency chain. But enabling
a different block module results in forming circular locking dependency
due to shared major_names_lock mutex.
The simplest fix is to call probe function without holding
major_names_lock [1], but Christoph Hellwig does not like such idea.
Therefore, instead of holding major_names_lock in blkdev_show(),
introduce a different lock for blkdev_show() in order to break
"sb_writers#$N => &p->lock => major_names_lock" dependency chain.
Link: https://lkml.kernel.org/r/[email protected] [1]
Signed-off-by: Tetsuo Handa <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>
okias
pushed a commit
that referenced
this pull request
Sep 14, 2021
when turning off a connection, lockdep complains with the following warning (a modprobe has been done but the same happens with a disconnection from NetworkManager, it's enough to trigger a cfg80211_disconnect call): [ 682.855867] ====================================================== [ 682.855877] WARNING: possible circular locking dependency detected [ 682.855887] 5.14.0-rc6+ grate-driver#16 Tainted: G C OE [ 682.855898] ------------------------------------------------------ [ 682.855906] modprobe/1770 is trying to acquire lock: [ 682.855916] ffffb6d000332b00 (&pxmitpriv->lock){+.-.}-{2:2}, at: rtw_free_stainfo+0x52/0x4a0 [r8723bs] [ 682.856073] but task is already holding lock: [ 682.856081] ffffb6d0003336a8 (&pstapriv->sta_hash_lock){+.-.}-{2:2}, at: rtw_free_assoc_resources+0x48/0x110 [r8723bs] [ 682.856207] which lock already depends on the new lock. [ 682.856215] the existing dependency chain (in reverse order) is: [ 682.856223] -> #1 (&pstapriv->sta_hash_lock){+.-.}-{2:2}: [ 682.856247] _raw_spin_lock_bh+0x34/0x40 [ 682.856265] rtw_get_stainfo+0x9a/0x110 [r8723bs] [ 682.856389] rtw_xmit_classifier+0x27/0x130 [r8723bs] [ 682.856515] rtw_xmitframe_enqueue+0xa/0x20 [r8723bs] [ 682.856642] rtl8723bs_hal_xmit+0x3b/0xb0 [r8723bs] [ 682.856752] rtw_xmit+0x4ef/0x890 [r8723bs] [ 682.856879] _rtw_xmit_entry+0xba/0x350 [r8723bs] [ 682.856981] dev_hard_start_xmit+0xee/0x320 [ 682.856999] sch_direct_xmit+0x8c/0x330 [ 682.857014] __dev_queue_xmit+0xba5/0xf00 [ 682.857030] packet_sendmsg+0x981/0x1b80 [ 682.857047] sock_sendmsg+0x5b/0x60 [ 682.857060] __sys_sendto+0xf1/0x160 [ 682.857073] __x64_sys_sendto+0x24/0x30 [ 682.857087] do_syscall_64+0x3a/0x80 [ 682.857102] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 682.857117] -> #0 (&pxmitpriv->lock){+.-.}-{2:2}: [ 682.857142] __lock_acquire+0xfd9/0x1b50 [ 682.857158] lock_acquire+0xb4/0x2c0 [ 682.857172] _raw_spin_lock_bh+0x34/0x40 [ 682.857185] rtw_free_stainfo+0x52/0x4a0 [r8723bs] [ 682.857308] rtw_free_assoc_resources+0x53/0x110 [r8723bs] [ 682.857415] cfg80211_rtw_disconnect+0x4b/0x70 [r8723bs] [ 682.857522] cfg80211_disconnect+0x12e/0x2f0 [cfg80211] [ 682.857759] cfg80211_leave+0x2b/0x40 [cfg80211] [ 682.857961] cfg80211_netdev_notifier_call+0xa9/0x560 [cfg80211] [ 682.858163] raw_notifier_call_chain+0x41/0x50 [ 682.858180] __dev_close_many+0x62/0x100 [ 682.858195] dev_close_many+0x7d/0x120 [ 682.858209] unregister_netdevice_many+0x416/0x680 [ 682.858225] unregister_netdevice_queue+0xab/0xf0 [ 682.858240] unregister_netdev+0x18/0x20 [ 682.858255] rtw_unregister_netdevs+0x28/0x40 [r8723bs] [ 682.858360] rtw_dev_remove+0x24/0xd0 [r8723bs] [ 682.858463] sdio_bus_remove+0x31/0xd0 [mmc_core] [ 682.858532] device_release_driver_internal+0xf7/0x1d0 [ 682.858550] driver_detach+0x47/0x90 [ 682.858564] bus_remove_driver+0x77/0xd0 [ 682.858579] rtw_drv_halt+0xc/0x678 [r8723bs] [ 682.858685] __x64_sys_delete_module+0x13f/0x250 [ 682.858699] do_syscall_64+0x3a/0x80 [ 682.858715] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 682.858729] other info that might help us debug this: [ 682.858737] Possible unsafe locking scenario: [ 682.858744] CPU0 CPU1 [ 682.858751] ---- ---- [ 682.858758] lock(&pstapriv->sta_hash_lock); [ 682.858772] lock(&pxmitpriv->lock); [ 682.858786] lock(&pstapriv->sta_hash_lock); [ 682.858799] lock(&pxmitpriv->lock); [ 682.858812] *** DEADLOCK *** [ 682.858820] 5 locks held by modprobe/1770: [ 682.858831] #0: ffff8d870697d980 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0x1a/0x1d0 [ 682.858869] #1: ffffffffbdbbf1c8 (rtnl_mutex){+.+.}-{3:3}, at: unregister_netdev+0xe/0x20 [ 682.858906] #2: ffff8d87054ee5e8 (&rdev->wiphy.mtx){+.+.}-{3:3}, at: cfg80211_netdev_notifier_call+0x9e/0x560 [cfg80211] [ 682.859131] #3: ffff8d870f2bc8f0 (&wdev->mtx){+.+.}-{3:3}, at: cfg80211_leave+0x20/0x40 [cfg80211] [ 682.859354] #4: ffffb6d0003336a8 (&pstapriv->sta_hash_lock){+.-.}-{2:2}, at: rtw_free_assoc_resources+0x48/0x110 [r8723bs] [ 682.859482] stack backtrace: [ 682.859491] CPU: 1 PID: 1770 Comm: modprobe Tainted: G C OE 5.14.0-rc6+ grate-driver#16 [ 682.859507] Hardware name: LENOVO 80NR/Madrid, BIOS DACN25WW 08/20/2015 [ 682.859517] Call Trace: [ 682.859531] dump_stack_lvl+0x56/0x6f [ 682.859551] check_noncircular+0xdb/0xf0 [ 682.859579] __lock_acquire+0xfd9/0x1b50 [ 682.859606] lock_acquire+0xb4/0x2c0 [ 682.859623] ? rtw_free_stainfo+0x52/0x4a0 [r8723bs] [ 682.859752] ? mark_held_locks+0x48/0x70 [ 682.859769] ? rtw_free_stainfo+0x4a/0x4a0 [r8723bs] [ 682.859898] _raw_spin_lock_bh+0x34/0x40 [ 682.859914] ? rtw_free_stainfo+0x52/0x4a0 [r8723bs] [ 682.860039] rtw_free_stainfo+0x52/0x4a0 [r8723bs] [ 682.860171] rtw_free_assoc_resources+0x53/0x110 [r8723bs] [ 682.860286] cfg80211_rtw_disconnect+0x4b/0x70 [r8723bs] [ 682.860397] cfg80211_disconnect+0x12e/0x2f0 [cfg80211] [ 682.860629] cfg80211_leave+0x2b/0x40 [cfg80211] [ 682.860836] cfg80211_netdev_notifier_call+0xa9/0x560 [cfg80211] [ 682.861048] ? __lock_acquire+0x4dc/0x1b50 [ 682.861070] ? lock_is_held_type+0xa8/0x110 [ 682.861089] ? lock_is_held_type+0xa8/0x110 [ 682.861104] ? find_held_lock+0x2d/0x90 [ 682.861120] ? packet_notifier+0x173/0x300 [ 682.861141] ? lock_release+0xb3/0x250 [ 682.861160] ? packet_notifier+0x192/0x300 [ 682.861184] raw_notifier_call_chain+0x41/0x50 [ 682.861205] __dev_close_many+0x62/0x100 [ 682.861224] dev_close_many+0x7d/0x120 [ 682.861245] unregister_netdevice_many+0x416/0x680 [ 682.861264] ? find_held_lock+0x2d/0x90 [ 682.861284] unregister_netdevice_queue+0xab/0xf0 [ 682.861306] unregister_netdev+0x18/0x20 [ 682.861325] rtw_unregister_netdevs+0x28/0x40 [r8723bs] [ 682.861434] rtw_dev_remove+0x24/0xd0 [r8723bs] [ 682.861542] sdio_bus_remove+0x31/0xd0 [mmc_core] [ 682.861615] device_release_driver_internal+0xf7/0x1d0 [ 682.861637] driver_detach+0x47/0x90 [ 682.861656] bus_remove_driver+0x77/0xd0 [ 682.861674] rtw_drv_halt+0xc/0x678 [r8723bs] [ 682.861782] __x64_sys_delete_module+0x13f/0x250 [ 682.861801] ? lockdep_hardirqs_on_prepare+0xf3/0x170 [ 682.861817] ? syscall_enter_from_user_mode+0x20/0x70 [ 682.861836] do_syscall_64+0x3a/0x80 [ 682.861855] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 682.861873] RIP: 0033:0x7f6dbe85400b [ 682.861890] Code: 73 01 c3 48 8b 0d 6d 1e 0c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa b8 b0 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 3d 1e 0c 00 f7 d8 64 89 01 48 [ 682.861906] RSP: 002b:00007ffe7a82f538 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0 [ 682.861923] RAX: ffffffffffffffda RBX: 000055a64693bd20 RCX: 00007f6dbe85400b [ 682.861935] RDX: 0000000000000000 RSI: 0000000000000800 RDI: 000055a64693bd88 [ 682.861946] RBP: 000055a64693bd20 R08: 0000000000000000 R09: 0000000000000000 [ 682.861957] R10: 00007f6dbe8c7ac0 R11: 0000000000000206 R12: 000055a64693bd88 [ 682.861967] R13: 0000000000000000 R14: 000055a64693bd88 R15: 00007ffe7a831848 This happens because when we enqueue a frame for transmission we do it under xmit_priv lock, then calling rtw_get_stainfo (needed for enqueuing) takes sta_hash_lock and this leads to the following lock dependency: xmit_priv->lock -> sta_hash_lock Turning off a connection will bring to call rtw_free_assoc_resources which will set up the inverse dependency: sta_hash_lock -> xmit_priv_lock This could lead to a deadlock as lockdep complains. Fix it by removing the xmit_priv->lock around rtw_xmitframe_enqueue call inside rtl8723bs_hal_xmit and put it in a smaller critical section inside rtw_xmit_classifier, the only place where xmit_priv data are actually accessed. Replace spin_{lock,unlock}_bh(pxmitpriv->lock) in other tx paths leading to rtw_xmitframe_enqueue call with spin_{lock,unlock}_bh(psta->sleep_q.lock) - it's not clear why accessing a sleep_q was protected by a spinlock on xmitpriv->lock. This way is avoided the same faulty lock nesting order. CC: Larry Finger <[email protected]> Tested-on: Lenovo Ideapad MiiX 300-10IBY Signed-off-by: Fabio Aiuto <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
okias
pushed a commit
that referenced
this pull request
Sep 14, 2021
We got the following lockdep splat while running xfstests (specifically btrfs/003 and btrfs/020 in a row) with the new rc. This was uncovered by 87579e9 ("loop: use worker per cgroup instead of kworker") which converted loop to using workqueues, which comes with lockdep annotations that don't exist with kworkers. The lockdep splat is as follows ====================================================== WARNING: possible circular locking dependency detected 5.14.0-rc2-custom+ grate-driver#34 Not tainted ------------------------------------------------------ losetup/156417 is trying to acquire lock: ffff9c7645b02d38 ((wq_completion)loop0){+.+.}-{0:0}, at: flush_workqueue+0x84/0x600 but task is already holding lock: ffff9c7647395468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x650 [loop] which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #5 (&lo->lo_mutex){+.+.}-{3:3}: __mutex_lock+0xba/0x7c0 lo_open+0x28/0x60 [loop] blkdev_get_whole+0x28/0xf0 blkdev_get_by_dev.part.0+0x168/0x3c0 blkdev_open+0xd2/0xe0 do_dentry_open+0x163/0x3a0 path_openat+0x74d/0xa40 do_filp_open+0x9c/0x140 do_sys_openat2+0xb1/0x170 __x64_sys_openat+0x54/0x90 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #4 (&disk->open_mutex){+.+.}-{3:3}: __mutex_lock+0xba/0x7c0 blkdev_get_by_dev.part.0+0xd1/0x3c0 blkdev_get_by_path+0xc0/0xd0 btrfs_scan_one_device+0x52/0x1f0 [btrfs] btrfs_control_ioctl+0xac/0x170 [btrfs] __x64_sys_ioctl+0x83/0xb0 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #3 (uuid_mutex){+.+.}-{3:3}: __mutex_lock+0xba/0x7c0 btrfs_rm_device+0x48/0x6a0 [btrfs] btrfs_ioctl+0x2d1c/0x3110 [btrfs] __x64_sys_ioctl+0x83/0xb0 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #2 (sb_writers#11){.+.+}-{0:0}: lo_write_bvec+0x112/0x290 [loop] loop_process_work+0x25f/0xcb0 [loop] process_one_work+0x28f/0x5d0 worker_thread+0x55/0x3c0 kthread+0x140/0x170 ret_from_fork+0x22/0x30 -> #1 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}: process_one_work+0x266/0x5d0 worker_thread+0x55/0x3c0 kthread+0x140/0x170 ret_from_fork+0x22/0x30 -> #0 ((wq_completion)loop0){+.+.}-{0:0}: __lock_acquire+0x1130/0x1dc0 lock_acquire+0xf5/0x320 flush_workqueue+0xae/0x600 drain_workqueue+0xa0/0x110 destroy_workqueue+0x36/0x250 __loop_clr_fd+0x9a/0x650 [loop] lo_ioctl+0x29d/0x780 [loop] block_ioctl+0x3f/0x50 __x64_sys_ioctl+0x83/0xb0 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae other info that might help us debug this: Chain exists of: (wq_completion)loop0 --> &disk->open_mutex --> &lo->lo_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&lo->lo_mutex); lock(&disk->open_mutex); lock(&lo->lo_mutex); lock((wq_completion)loop0); *** DEADLOCK *** 1 lock held by losetup/156417: #0: ffff9c7647395468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x650 [loop] stack backtrace: CPU: 8 PID: 156417 Comm: losetup Not tainted 5.14.0-rc2-custom+ grate-driver#34 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 Call Trace: dump_stack_lvl+0x57/0x72 check_noncircular+0x10a/0x120 __lock_acquire+0x1130/0x1dc0 lock_acquire+0xf5/0x320 ? flush_workqueue+0x84/0x600 flush_workqueue+0xae/0x600 ? flush_workqueue+0x84/0x600 drain_workqueue+0xa0/0x110 destroy_workqueue+0x36/0x250 __loop_clr_fd+0x9a/0x650 [loop] lo_ioctl+0x29d/0x780 [loop] ? __lock_acquire+0x3a0/0x1dc0 ? update_dl_rq_load_avg+0x152/0x360 ? lock_is_held_type+0xa5/0x120 ? find_held_lock.constprop.0+0x2b/0x80 block_ioctl+0x3f/0x50 __x64_sys_ioctl+0x83/0xb0 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f645884de6b Usually the uuid_mutex exists to protect the fs_devices that map together all of the devices that match a specific uuid. In rm_device we're messing with the uuid of a device, so it makes sense to protect that here. However in doing that it pulls in a whole host of lockdep dependencies, as we call mnt_may_write() on the sb before we grab the uuid_mutex, thus we end up with the dependency chain under the uuid_mutex being added under the normal sb write dependency chain, which causes problems with loop devices. We don't need the uuid mutex here however. If we call btrfs_scan_one_device() before we scratch the super block we will find the fs_devices and not find the device itself and return EBUSY because the fs_devices is open. If we call it after the scratch happens it will not appear to be a valid btrfs file system. We do not need to worry about other fs_devices modifying operations here because we're protected by the exclusive operations locking. So drop the uuid_mutex here in order to fix the lockdep splat. Signed-off-by: Josef Bacik <[email protected]> Signed-off-by: David Sterba <[email protected]>
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Host crashes when pci_enable_atomic_ops_to_root() is called for VFs with virtual buses. The virtual buses added to SR-IOV have bus->self set to NULL and host crashes due to this. PID: 4481 TASK: ffff89c6941b0000 CPU: 53 COMMAND: "bash" ... #3 [ffff9a9481713808] oops_end at ffffffffb9025cd6 #4 [ffff9a9481713828] page_fault_oops at ffffffffb906e417 #5 [ffff9a9481713888] exc_page_fault at ffffffffb9a0ad14 #6 [ffff9a94817138b0] asm_exc_page_fault at ffffffffb9c00ace [exception RIP: pcie_capability_read_dword+28] RIP: ffffffffb952fd5c RSP: ffff9a9481713960 RFLAGS: 00010246 RAX: 0000000000000001 RBX: ffff89c6b1096000 RCX: 0000000000000000 RDX: ffff9a9481713990 RSI: 0000000000000024 RDI: 0000000000000000 RBP: 0000000000000080 R8: 0000000000000008 R9: ffff89c64341a2f8 R10: 0000000000000002 R11: 0000000000000000 R12: ffff89c648bab000 R13: 0000000000000000 R14: 0000000000000000 R15: ffff89c648bab0c8 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #7 [ffff9a9481713988] pci_enable_atomic_ops_to_root at ffffffffb95359a6 #8 [ffff9a94817139c0] bnxt_qplib_determine_atomics at ffffffffc08c1a33 [bnxt_re] grate-driver#9 [ffff9a94817139d0] bnxt_re_dev_init at ffffffffc08ba2d1 [bnxt_re] Per PCIe r5.0, sec 9.3.5.10, the AtomicOp Requester Enable bit in Device Control 2 is reserved for VFs. The PF value applies to all associated VFs. Return -EINVAL if pci_enable_atomic_ops_to_root() is called for a VF. Link: https://lore.kernel.org/r/[email protected] Fixes: 35f5ace ("RDMA/bnxt_re: Enable global atomic ops if platform supports") Fixes: 430a236 ("PCI: Add pci_enable_atomic_ops_to_root()") Signed-off-by: Selvin Xavier <[email protected]> Signed-off-by: Bjorn Helgaas <[email protected]> Reviewed-by: Andy Gospodarek <[email protected]>
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It is generally unsafe to call put_device() with dpm_list_mtx held,
because the given device's release routine may carry out an action
depending on that lock which then may deadlock, so modify the
system-wide suspend and resume of devices to always drop dpm_list_mtx
before calling put_device() (and adjust white space somewhat while
at it).
For instance, this prevents the following splat from showing up in
the kernel log after a system resume in certain configurations:
[ 3290.969514] ======================================================
[ 3290.969517] WARNING: possible circular locking dependency detected
[ 3290.969519] 5.15.0+ #2420 Tainted: G S
[ 3290.969523] ------------------------------------------------------
[ 3290.969525] systemd-sleep/4553 is trying to acquire lock:
[ 3290.969529] ffff888117ab1138 ((wq_completion)hci0#2){+.+.}-{0:0}, at: flush_workqueue+0x87/0x4a0
[ 3290.969554]
but task is already holding lock:
[ 3290.969556] ffffffff8280fca8 (dpm_list_mtx){+.+.}-{3:3}, at: dpm_resume+0x12e/0x3e0
[ 3290.969571]
which lock already depends on the new lock.
[ 3290.969573]
the existing dependency chain (in reverse order) is:
[ 3290.969575]
-> #3 (dpm_list_mtx){+.+.}-{3:3}:
[ 3290.969583] __mutex_lock+0x9d/0xa30
[ 3290.969591] device_pm_add+0x2e/0xe0
[ 3290.969597] device_add+0x4d5/0x8f0
[ 3290.969605] hci_conn_add_sysfs+0x43/0xb0 [bluetooth]
[ 3290.969689] hci_conn_complete_evt.isra.71+0x124/0x750 [bluetooth]
[ 3290.969747] hci_event_packet+0xd6c/0x28a0 [bluetooth]
[ 3290.969798] hci_rx_work+0x213/0x640 [bluetooth]
[ 3290.969842] process_one_work+0x2aa/0x650
[ 3290.969851] worker_thread+0x39/0x400
[ 3290.969859] kthread+0x142/0x170
[ 3290.969865] ret_from_fork+0x22/0x30
[ 3290.969872]
-> #2 (&hdev->lock){+.+.}-{3:3}:
[ 3290.969881] __mutex_lock+0x9d/0xa30
[ 3290.969887] hci_event_packet+0xba/0x28a0 [bluetooth]
[ 3290.969935] hci_rx_work+0x213/0x640 [bluetooth]
[ 3290.969978] process_one_work+0x2aa/0x650
[ 3290.969985] worker_thread+0x39/0x400
[ 3290.969993] kthread+0x142/0x170
[ 3290.969999] ret_from_fork+0x22/0x30
[ 3290.970004]
-> #1 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}:
[ 3290.970013] process_one_work+0x27d/0x650
[ 3290.970020] worker_thread+0x39/0x400
[ 3290.970028] kthread+0x142/0x170
[ 3290.970033] ret_from_fork+0x22/0x30
[ 3290.970038]
-> #0 ((wq_completion)hci0#2){+.+.}-{0:0}:
[ 3290.970047] __lock_acquire+0x15cb/0x1b50
[ 3290.970054] lock_acquire+0x26c/0x300
[ 3290.970059] flush_workqueue+0xae/0x4a0
[ 3290.970066] drain_workqueue+0xa1/0x130
[ 3290.970073] destroy_workqueue+0x34/0x1f0
[ 3290.970081] hci_release_dev+0x49/0x180 [bluetooth]
[ 3290.970130] bt_host_release+0x1d/0x30 [bluetooth]
[ 3290.970195] device_release+0x33/0x90
[ 3290.970201] kobject_release+0x63/0x160
[ 3290.970211] dpm_resume+0x164/0x3e0
[ 3290.970215] dpm_resume_end+0xd/0x20
[ 3290.970220] suspend_devices_and_enter+0x1a4/0xba0
[ 3290.970229] pm_suspend+0x26b/0x310
[ 3290.970236] state_store+0x42/0x90
[ 3290.970243] kernfs_fop_write_iter+0x135/0x1b0
[ 3290.970251] new_sync_write+0x125/0x1c0
[ 3290.970257] vfs_write+0x360/0x3c0
[ 3290.970263] ksys_write+0xa7/0xe0
[ 3290.970269] do_syscall_64+0x3a/0x80
[ 3290.970276] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 3290.970284]
other info that might help us debug this:
[ 3290.970285] Chain exists of:
(wq_completion)hci0#2 --> &hdev->lock --> dpm_list_mtx
[ 3290.970297] Possible unsafe locking scenario:
[ 3290.970299] CPU0 CPU1
[ 3290.970300] ---- ----
[ 3290.970302] lock(dpm_list_mtx);
[ 3290.970306] lock(&hdev->lock);
[ 3290.970310] lock(dpm_list_mtx);
[ 3290.970314] lock((wq_completion)hci0#2);
[ 3290.970319]
*** DEADLOCK ***
[ 3290.970321] 7 locks held by systemd-sleep/4553:
[ 3290.970325] #0: ffff888103bcd448 (sb_writers#4){.+.+}-{0:0}, at: ksys_write+0xa7/0xe0
[ 3290.970341] #1: ffff888115a14488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x103/0x1b0
[ 3290.970355] #2: ffff888100f719e0 (kn->active#233){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x10c/0x1b0
[ 3290.970369] #3: ffffffff82661048 (autosleep_lock){+.+.}-{3:3}, at: state_store+0x12/0x90
[ 3290.970384] #4: ffffffff82658ac8 (system_transition_mutex){+.+.}-{3:3}, at: pm_suspend+0x9f/0x310
[ 3290.970399] #5: ffffffff827f2a48 (acpi_scan_lock){+.+.}-{3:3}, at: acpi_suspend_begin+0x4c/0x80
[ 3290.970416] #6: ffffffff8280fca8 (dpm_list_mtx){+.+.}-{3:3}, at: dpm_resume+0x12e/0x3e0
[ 3290.970428]
stack backtrace:
[ 3290.970431] CPU: 3 PID: 4553 Comm: systemd-sleep Tainted: G S 5.15.0+ #2420
[ 3290.970438] Hardware name: Dell Inc. XPS 13 9380/0RYJWW, BIOS 1.5.0 06/03/2019
[ 3290.970441] Call Trace:
[ 3290.970446] dump_stack_lvl+0x44/0x57
[ 3290.970454] check_noncircular+0x105/0x120
[ 3290.970468] ? __lock_acquire+0x15cb/0x1b50
[ 3290.970474] __lock_acquire+0x15cb/0x1b50
[ 3290.970487] lock_acquire+0x26c/0x300
[ 3290.970493] ? flush_workqueue+0x87/0x4a0
[ 3290.970503] ? __raw_spin_lock_init+0x3b/0x60
[ 3290.970510] ? lockdep_init_map_type+0x58/0x240
[ 3290.970519] flush_workqueue+0xae/0x4a0
[ 3290.970526] ? flush_workqueue+0x87/0x4a0
[ 3290.970544] ? drain_workqueue+0xa1/0x130
[ 3290.970552] drain_workqueue+0xa1/0x130
[ 3290.970561] destroy_workqueue+0x34/0x1f0
[ 3290.970572] hci_release_dev+0x49/0x180 [bluetooth]
[ 3290.970624] bt_host_release+0x1d/0x30 [bluetooth]
[ 3290.970687] device_release+0x33/0x90
[ 3290.970695] kobject_release+0x63/0x160
[ 3290.970705] dpm_resume+0x164/0x3e0
[ 3290.970710] ? dpm_resume_early+0x251/0x3b0
[ 3290.970718] dpm_resume_end+0xd/0x20
[ 3290.970723] suspend_devices_and_enter+0x1a4/0xba0
[ 3290.970737] pm_suspend+0x26b/0x310
[ 3290.970746] state_store+0x42/0x90
[ 3290.970755] kernfs_fop_write_iter+0x135/0x1b0
[ 3290.970764] new_sync_write+0x125/0x1c0
[ 3290.970777] vfs_write+0x360/0x3c0
[ 3290.970785] ksys_write+0xa7/0xe0
[ 3290.970794] do_syscall_64+0x3a/0x80
[ 3290.970803] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 3290.970811] RIP: 0033:0x7f41b1328164
[ 3290.970819] Code: 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 80 00 00 00 00 8b 05 4a d2 2c 00 48 63 ff 85 c0 75 13 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 f3 c3 66 90 55 53 48 89 d5 48 89 f3 48 83
[ 3290.970824] RSP: 002b:00007ffe6ae21b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[ 3290.970831] RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007f41b1328164
[ 3290.970836] RDX: 0000000000000004 RSI: 000055965e651070 RDI: 0000000000000004
[ 3290.970839] RBP: 000055965e651070 R08: 000055965e64f390 R09: 00007f41b1e3d1c0
[ 3290.970843] R10: 000000000000000a R11: 0000000000000246 R12: 0000000000000004
[ 3290.970846] R13: 0000000000000001 R14: 000055965e64f2b0 R15: 0000000000000004
Cc: All applicable <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>
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Patch series "Solve silent data loss caused by poisoned page cache (shmem/tmpfs)", v5.
When discussing the patch that splits page cache THP in order to offline
the poisoned page, Noaya mentioned there is a bigger problem [1] that
prevents this from working since the page cache page will be truncated
if uncorrectable errors happen. By looking this deeper it turns out
this approach (truncating poisoned page) may incur silent data loss for
all non-readonly filesystems if the page is dirty. It may be worse for
in-memory filesystem, e.g. shmem/tmpfs since the data blocks are
actually gone.
To solve this problem we could keep the poisoned dirty page in page
cache then notify the users on any later access, e.g. page fault,
read/write, etc. The clean page could be truncated as is since they can
be reread from disk later on.
The consequence is the filesystems may find poisoned page and manipulate
it as healthy page since all the filesystems actually don't check if the
page is poisoned or not in all the relevant paths except page fault. In
general, we need make the filesystems be aware of poisoned page before
we could keep the poisoned page in page cache in order to solve the data
loss problem.
To make filesystems be aware of poisoned page we should consider:
- The page should be not written back: clearing dirty flag could
prevent from writeback.
- The page should not be dropped (it shows as a clean page) by drop
caches or other callers: the refcount pin from hwpoison could prevent
from invalidating (called by cache drop, inode cache shrinking, etc),
but it doesn't avoid invalidation in DIO path.
- The page should be able to get truncated/hole punched/unlinked: it
works as it is.
- Notify users when the page is accessed, e.g. read/write, page fault
and other paths (compression, encryption, etc).
The scope of the last one is huge since almost all filesystems need do
it once a page is returned from page cache lookup. There are a couple
of options to do it:
1. Check hwpoison flag for every path, the most straightforward way.
2. Return NULL for poisoned page from page cache lookup, the most
callsites check if NULL is returned, this should have least work I
think. But the error handling in filesystems just return -ENOMEM,
the error code will incur confusion to the users obviously.
3. To improve #2, we could return error pointer, e.g. ERR_PTR(-EIO),
but this will involve significant amount of code change as well
since all the paths need check if the pointer is ERR or not just
like option #1.
I did prototypes for both #1 and #3, but it seems #3 may require more
changes than #1. For #3 ERR_PTR will be returned so all the callers
need to check the return value otherwise invalid pointer may be
dereferenced, but not all callers really care about the content of the
page, for example, partial truncate which just sets the truncated range
in one page to 0. So for such paths it needs additional modification if
ERR_PTR is returned. And if the callers have their own way to handle
the problematic pages we need to add a new FGP flag to tell FGP
functions to return the pointer to the page.
It may happen very rarely, but once it happens the consequence (data
corruption) could be very bad and it is very hard to debug. It seems
this problem had been slightly discussed before, but seems no action was
taken at that time. [2]
As the aforementioned investigation, it needs huge amount of work to
solve the potential data loss for all filesystems. But it is much
easier for in-memory filesystems and such filesystems actually suffer
more than others since even the data blocks are gone due to truncating.
So this patchset starts from shmem/tmpfs by taking option #1.
TODO:
* The unpoison has been broken since commit 0ed950d ("mm,hwpoison: make
get_hwpoison_page() call get_any_page()"), and this patch series make
refcount check for unpoisoning shmem page fail.
* Expand to other filesystems. But I haven't heard feedback from filesystem
developers yet.
Patch breakdown:
Patch #1: cleanup, depended by patch #2
Patch #2: fix THP with hwpoisoned subpage(s) PMD map bug
Patch #3: coding style cleanup
Patch #4: refactor and preparation.
Patch #5: keep the poisoned page in page cache and handle such case for all
the paths.
Patch #6: the previous patches unblock page cache THP split, so this patch
add page cache THP split support.
This patch (of 4):
A minor cleanup to the indent.
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Yang Shi <[email protected]>
Reviewed-by: Naoya Horiguchi <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Kirill A. Shutemov <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Oscar Salvador <[email protected]>
Cc: Peter Xu <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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After removing /dev/kmem, sanitizing /proc/kcore and handling /dev/mem, this series tackles the last sane way how a VM could accidentially access logically unplugged memory managed by a virtio-mem device: /proc/vmcore When dumping memory via "makedumpfile", PG_offline pages, used by virtio-mem to flag logically unplugged memory, are already properly excluded; however, especially when accessing/copying /proc/vmcore "the usual way", we can still end up reading logically unplugged memory part of a virtio-mem device. Patch #1-#3 are cleanups. Patch #4 extends the existing oldmem_pfn_is_ram mechanism. Patch #5-#7 are virtio-mem refactorings for patch #8, which implements the virtio-mem logic to query the state of device blocks. Patch #8: " Although virtio-mem currently supports reading unplugged memory in the hypervisor, this will change in the future, indicated to the device via a new feature flag. We similarly sanitized /proc/kcore access recently. [...] Distributions that support virtio-mem+kdump have to make sure that the virtio_mem module will be part of the kdump kernel or the kdump initrd; dracut was recently [2] extended to include virtio-mem in the generated initrd. As long as no special kdump kernels are used, this will automatically make sure that virtio-mem will be around in the kdump initrd and sanitize /proc/vmcore access -- with dracut. " This is the last remaining bit to support VIRTIO_MEM_F_UNPLUGGED_INACCESSIBLE [3] in the Linux implementation of virtio-mem. Note: this is best-effort. We'll never be able to control what runs inside the second kernel, really, but we also don't have to care: we only care about sane setups where we don't want our VM getting zapped once we touch the wrong memory location while dumping. While we usually expect sane setups to use "makedumfile", nothing really speaks against just copying /proc/vmcore, especially in environments where HWpoisioning isn't typically expected. Also, we really don't want to put all our trust completely on the memmap, so sanitizing also makes sense when just using "makedumpfile". [1] https://lkml.kernel.org/r/[email protected] [2] dracutdevs/dracut#1157 [3] https://lists.oasis-open.org/archives/virtio-comment/202109/msg00021.html This patch (of 9): The callback is only used for the vmcore nowadays. Link: https://lkml.kernel.org/r/[email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: David Hildenbrand <[email protected]> Reviewed-by: Boris Ostrovsky <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: "H. Peter Anvin" <[email protected]> Cc: Juergen Gross <[email protected]> Cc: Stefano Stabellini <[email protected]> Cc: "Michael S. Tsirkin" <[email protected]> Cc: Jason Wang <[email protected]> Cc: Dave Young <[email protected]> Cc: Baoquan He <[email protected]> Cc: Vivek Goyal <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Oscar Salvador <[email protected]> Cc: Mike Rapoport <[email protected]> Cc: "Rafael J. Wysocki" <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Stephen Rothwell <[email protected]>
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Nov 10, 2021
After removing /dev/kmem, sanitizing /proc/kcore and handling /dev/mem, this series tackles the last sane way how a VM could accidentially access logically unplugged memory managed by a virtio-mem device: /proc/vmcore When dumping memory via "makedumpfile", PG_offline pages, used by virtio-mem to flag logically unplugged memory, are already properly excluded; however, especially when accessing/copying /proc/vmcore "the usual way", we can still end up reading logically unplugged memory part of a virtio-mem device. Patch #1-#3 are cleanups. Patch #4 extends the existing oldmem_pfn_is_ram mechanism. Patch #5-#7 are virtio-mem refactorings for patch #8, which implements the virtio-mem logic to query the state of device blocks. Patch #8: "Although virtio-mem currently supports reading unplugged memory in the hypervisor, this will change in the future, indicated to the device via a new feature flag. We similarly sanitized /proc/kcore access recently. [...] Distributions that support virtio-mem+kdump have to make sure that the virtio_mem module will be part of the kdump kernel or the kdump initrd; dracut was recently [2] extended to include virtio-mem in the generated initrd. As long as no special kdump kernels are used, this will automatically make sure that virtio-mem will be around in the kdump initrd and sanitize /proc/vmcore access -- with dracut" This is the last remaining bit to support VIRTIO_MEM_F_UNPLUGGED_INACCESSIBLE [3] in the Linux implementation of virtio-mem. Note: this is best-effort. We'll never be able to control what runs inside the second kernel, really, but we also don't have to care: we only care about sane setups where we don't want our VM getting zapped once we touch the wrong memory location while dumping. While we usually expect sane setups to use "makedumfile", nothing really speaks against just copying /proc/vmcore, especially in environments where HWpoisioning isn't typically expected. Also, we really don't want to put all our trust completely on the memmap, so sanitizing also makes sense when just using "makedumpfile". [1] https://lkml.kernel.org/r/[email protected] [2] dracutdevs/dracut#1157 [3] https://lists.oasis-open.org/archives/virtio-comment/202109/msg00021.html This patch (of 9): The callback is only used for the vmcore nowadays. Link: https://lkml.kernel.org/r/[email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: David Hildenbrand <[email protected]> Reviewed-by: Boris Ostrovsky <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: "H. Peter Anvin" <[email protected]> Cc: Juergen Gross <[email protected]> Cc: Stefano Stabellini <[email protected]> Cc: "Michael S. Tsirkin" <[email protected]> Cc: Jason Wang <[email protected]> Cc: Dave Young <[email protected]> Cc: Baoquan He <[email protected]> Cc: Vivek Goyal <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Oscar Salvador <[email protected]> Cc: Mike Rapoport <[email protected]> Cc: "Rafael J. Wysocki" <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
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commit 232796d upstream. When enabling quotas, we attempt to commit a transaction while holding the mutex fs_info->qgroup_ioctl_lock. This can result on a deadlock with other quota operations such as: - qgroup creation and deletion, ioctl BTRFS_IOC_QGROUP_CREATE; - adding and removing qgroup relations, ioctl BTRFS_IOC_QGROUP_ASSIGN. This is because these operations join a transaction and after that they attempt to lock the mutex fs_info->qgroup_ioctl_lock. Acquiring that mutex after joining or starting a transaction is a pattern followed everywhere in qgroups, so the quota enablement operation is the one at fault here, and should not commit a transaction while holding that mutex. Fix this by making the transaction commit while not holding the mutex. We are safe from two concurrent tasks trying to enable quotas because we are serialized by the rw semaphore fs_info->subvol_sem at btrfs_ioctl_quota_ctl(), which is the only call site for enabling quotas. When this deadlock happens, it produces a trace like the following: INFO: task syz-executor:25604 blocked for more than 143 seconds. Not tainted 5.15.0-rc6 #4 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:24800 pid:25604 ppid: 24873 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4940 [inline] __schedule+0xcd9/0x2530 kernel/sched/core.c:6287 schedule+0xd3/0x270 kernel/sched/core.c:6366 btrfs_commit_transaction+0x994/0x2e90 fs/btrfs/transaction.c:2201 btrfs_quota_enable+0x95c/0x1790 fs/btrfs/qgroup.c:1120 btrfs_ioctl_quota_ctl fs/btrfs/ioctl.c:4229 [inline] btrfs_ioctl+0x637e/0x7b70 fs/btrfs/ioctl.c:5010 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl fs/ioctl.c:860 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f86920b2c4d RSP: 002b:00007f868f61ac58 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f86921d90a0 RCX: 00007f86920b2c4d RDX: 0000000020005e40 RSI: 00000000c0109428 RDI: 0000000000000008 RBP: 00007f869212bd80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f86921d90a0 R13: 00007fff6d233e4f R14: 00007fff6d233ff0 R15: 00007f868f61adc0 INFO: task syz-executor:25628 blocked for more than 143 seconds. Not tainted 5.15.0-rc6 #4 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:29080 pid:25628 ppid: 24873 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4940 [inline] __schedule+0xcd9/0x2530 kernel/sched/core.c:6287 schedule+0xd3/0x270 kernel/sched/core.c:6366 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6425 __mutex_lock_common kernel/locking/mutex.c:669 [inline] __mutex_lock+0xc96/0x1680 kernel/locking/mutex.c:729 btrfs_remove_qgroup+0xb7/0x7d0 fs/btrfs/qgroup.c:1548 btrfs_ioctl_qgroup_create fs/btrfs/ioctl.c:4333 [inline] btrfs_ioctl+0x683c/0x7b70 fs/btrfs/ioctl.c:5014 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl fs/ioctl.c:860 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Reported-by: Hao Sun <[email protected]> Link: https://lore.kernel.org/linux-btrfs/CACkBjsZQF19bQ1C6=yetF3BvL10OSORpFUcWXTP6HErshDB4dQ@mail.gmail.com/ Fixes: 340f1aa ("btrfs: qgroups: Move transaction management inside btrfs_quota_enable/disable") CC: [email protected] # 4.19 Reviewed-by: Qu Wenruo <[email protected]> Signed-off-by: Filipe Manana <[email protected]> Signed-off-by: David Sterba <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
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commit 8b59b0a upstream. arm32 uses software to simulate the instruction replaced by kprobe. some instructions may be simulated by constructing assembly functions. therefore, before executing instruction simulation, it is necessary to construct assembly function execution environment in C language through binding registers. after kasan is enabled, the register binding relationship will be destroyed, resulting in instruction simulation errors and causing kernel panic. the kprobe emulate instruction function is distributed in three files: actions-common.c actions-arm.c actions-thumb.c, so disable KASAN when compiling these files. for example, use kprobe insert on cap_capable+20 after kasan enabled, the cap_capable assembly code is as follows: <cap_capable>: e92d47f0 push {r4, r5, r6, r7, r8, r9, sl, lr} e1a05000 mov r5, r0 e280006c add r0, r0, grate-driver#108 ; 0x6c e1a04001 mov r4, r1 e1a06002 mov r6, r2 e59fa090 ldr sl, [pc, #144] ; ebfc7bf8 bl c03aa4b4 <__asan_load4> e595706c ldr r7, [r5, grate-driver#108] ; 0x6c e2859014 add r9, r5, grate-driver#20 ...... The emulate_ldr assembly code after enabling kasan is as follows: c06f1384 <emulate_ldr>: e92d47f0 push {r4, r5, r6, r7, r8, r9, sl, lr} e282803c add r8, r2, grate-driver#60 ; 0x3c e1a05000 mov r5, r0 e7e37855 ubfx r7, r5, grate-driver#16, #4 e1a00008 mov r0, r8 e1a09001 mov r9, r1 e1a04002 mov r4, r2 ebf35462 bl c03c6530 <__asan_load4> e357000f cmp r7, grate-driver#15 e7e36655 ubfx r6, r5, grate-driver#12, #4 e205a00f and sl, r5, grate-driver#15 0a000001 beq c06f13bc <emulate_ldr+0x38> e0840107 add r0, r4, r7, lsl #2 ebf3545c bl c03c6530 <__asan_load4> e084010a add r0, r4, sl, lsl #2 ebf3545a bl c03c6530 <__asan_load4> e2890010 add r0, r9, grate-driver#16 ebf35458 bl c03c6530 <__asan_load4> e5990010 ldr r0, [r9, grate-driver#16] e12fff30 blx r0 e356000f cm r6, grate-driver#15 1a000014 bne c06f1430 <emulate_ldr+0xac> e1a06000 mov r6, r0 e2840040 add r0, r4, grate-driver#64 ; 0x40 ...... when running in emulate_ldr to simulate the ldr instruction, panic occurred, and the log is as follows: Unable to handle kernel NULL pointer dereference at virtual address 00000090 pgd = ecb46400 [00000090] *pgd=2e0fa003, *pmd=00000000 Internal error: Oops: 206 [#1] SMP ARM PC is at cap_capable+0x14/0xb0 LR is at emulate_ldr+0x50/0xc0 psr: 600d0293 sp : ecd63af8 ip : 00000004 fp : c0a7c30c r10: 00000000 r9 : c30897f4 r8 : ecd63cd4 r7 : 0000000f r6 : 0000000a r5 : e59fa090 r4 : ecd63c98 r3 : c06ae294 r2 : 00000000 r1 : b7611300 r0 : bf4ec008 Flags: nZCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment user Control: 32c5387d Table: 2d546400 DAC: 55555555 Process bash (pid: 1643, stack limit = 0xecd60190) (cap_capable) from (kprobe_handler+0x218/0x340) (kprobe_handler) from (kprobe_trap_handler+0x24/0x48) (kprobe_trap_handler) from (do_undefinstr+0x13c/0x364) (do_undefinstr) from (__und_svc_finish+0x0/0x30) (__und_svc_finish) from (cap_capable+0x18/0xb0) (cap_capable) from (cap_vm_enough_memory+0x38/0x48) (cap_vm_enough_memory) from (security_vm_enough_memory_mm+0x48/0x6c) (security_vm_enough_memory_mm) from (copy_process.constprop.5+0x16b4/0x25c8) (copy_process.constprop.5) from (_do_fork+0xe8/0x55c) (_do_fork) from (SyS_clone+0x1c/0x24) (SyS_clone) from (__sys_trace_return+0x0/0x10) Code: 0050a0e1 6c0080e2 0140a0e1 0260a0e1 (f801f0e7) Fixes: 35aa1df ("ARM kprobes: instruction single-stepping support") Fixes: 4210157 ("ARM: 9017/2: Enable KASan for ARM") Signed-off-by: huangshaobo <[email protected]> Acked-by: Ard Biesheuvel <[email protected]> Signed-off-by: Russell King (Oracle) <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
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[ Upstream commit 99d4850 ] Found by leak sanitizer: ``` ==1632594==ERROR: LeakSanitizer: detected memory leaks Direct leak of 21 byte(s) in 1 object(s) allocated from: #0 0x7f2953a7077b in __interceptor_strdup ../../../../src/libsanitizer/asan/asan_interceptors.cpp:439 #1 0x556701d6fbbf in perf_env__read_cpuid util/env.c:369 #2 0x556701d70589 in perf_env__cpuid util/env.c:465 #3 0x55670204bba2 in x86__is_amd_cpu arch/x86/util/env.c:14 #4 0x5567020487a2 in arch__post_evsel_config arch/x86/util/evsel.c:83 #5 0x556701d8f78b in evsel__config util/evsel.c:1366 #6 0x556701ef5872 in evlist__config util/record.c:108 #7 0x556701cd6bcd in test__PERF_RECORD tests/perf-record.c:112 #8 0x556701cacd07 in run_test tests/builtin-test.c:236 grate-driver#9 0x556701cacfac in test_and_print tests/builtin-test.c:265 grate-driver#10 0x556701cadddb in __cmd_test tests/builtin-test.c:402 grate-driver#11 0x556701caf2aa in cmd_test tests/builtin-test.c:559 grate-driver#12 0x556701d3b557 in run_builtin tools/perf/perf.c:323 grate-driver#13 0x556701d3bac8 in handle_internal_command tools/perf/perf.c:377 grate-driver#14 0x556701d3be90 in run_argv tools/perf/perf.c:421 grate-driver#15 0x556701d3c3f8 in main tools/perf/perf.c:537 grate-driver#16 0x7f2952a46189 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58 SUMMARY: AddressSanitizer: 21 byte(s) leaked in 1 allocation(s). ``` Fixes: f7b58cb ("perf mem/c2c: Add load store event mappings for AMD") Signed-off-by: Ian Rogers <[email protected]> Acked-by: Ravi Bangoria <[email protected]> Tested-by: Arnaldo Carvalho de Melo <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Ravi Bangoria <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
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[ Upstream commit b684c09 ] ppc_save_regs() skips one stack frame while saving the CPU register states. Instead of saving current R1, it pulls the previous stack frame pointer. When vmcores caused by direct panic call (such as `echo c > /proc/sysrq-trigger`), are debugged with gdb, gdb fails to show the backtrace correctly. On further analysis, it was found that it was because of mismatch between r1 and NIP. GDB uses NIP to get current function symbol and uses corresponding debug info of that function to unwind previous frames, but due to the mismatching r1 and NIP, the unwinding does not work, and it fails to unwind to the 2nd frame and hence does not show the backtrace. GDB backtrace with vmcore of kernel without this patch: --------- (gdb) bt #0 0xc0000000002a53e8 in crash_setup_regs (oldregs=<optimized out>, newregs=0xc000000004f8f8d8) at ./arch/powerpc/include/asm/kexec.h:69 #1 __crash_kexec (regs=<optimized out>) at kernel/kexec_core.c:974 #2 0x0000000000000063 in ?? () #3 0xc000000003579320 in ?? () --------- Further analysis revealed that the mismatch occurred because "ppc_save_regs" was saving the previous stack's SP instead of the current r1. This patch fixes this by storing current r1 in the saved pt_regs. GDB backtrace with vmcore of patched kernel: -------- (gdb) bt #0 0xc0000000002a53e8 in crash_setup_regs (oldregs=0x0, newregs=0xc00000000670b8d8) at ./arch/powerpc/include/asm/kexec.h:69 #1 __crash_kexec (regs=regs@entry=0x0) at kernel/kexec_core.c:974 #2 0xc000000000168918 in panic (fmt=fmt@entry=0xc000000001654a60 "sysrq triggered crash\n") at kernel/panic.c:358 #3 0xc000000000b735f8 in sysrq_handle_crash (key=<optimized out>) at drivers/tty/sysrq.c:155 #4 0xc000000000b742cc in __handle_sysrq (key=key@entry=99, check_mask=check_mask@entry=false) at drivers/tty/sysrq.c:602 #5 0xc000000000b7506c in write_sysrq_trigger (file=<optimized out>, buf=<optimized out>, count=2, ppos=<optimized out>) at drivers/tty/sysrq.c:1163 #6 0xc00000000069a7bc in pde_write (ppos=<optimized out>, count=<optimized out>, buf=<optimized out>, file=<optimized out>, pde=0xc00000000362cb40) at fs/proc/inode.c:340 #7 proc_reg_write (file=<optimized out>, buf=<optimized out>, count=<optimized out>, ppos=<optimized out>) at fs/proc/inode.c:352 #8 0xc0000000005b3bbc in vfs_write (file=file@entry=0xc000000006aa6b00, buf=buf@entry=0x61f498b4f60 <error: Cannot access memory at address 0x61f498b4f60>, count=count@entry=2, pos=pos@entry=0xc00000000670bda0) at fs/read_write.c:582 grate-driver#9 0xc0000000005b4264 in ksys_write (fd=<optimized out>, buf=0x61f498b4f60 <error: Cannot access memory at address 0x61f498b4f60>, count=2) at fs/read_write.c:637 grate-driver#10 0xc00000000002ea2c in system_call_exception (regs=0xc00000000670be80, r0=<optimized out>) at arch/powerpc/kernel/syscall.c:171 grate-driver#11 0xc00000000000c270 in system_call_vectored_common () at arch/powerpc/kernel/interrupt_64.S:192 -------- Nick adds: So this now saves regs as though it was an interrupt taken in the caller, at the instruction after the call to ppc_save_regs, whereas previously the NIP was there, but R1 came from the caller's caller and that mismatch is what causes gdb's dwarf unwinder to go haywire. Signed-off-by: Aditya Gupta <[email protected]> Fixes: d16a58f ("powerpc: Improve ppc_save_regs()") Reivewed-by: Nicholas Piggin <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://msgid.link/[email protected] Signed-off-by: Sasha Levin <[email protected]>
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[ Upstream commit b7c6352 ] addend_arm_rel() processes R_ARM_ABS32 in a wrong way. Here, test code. [test code 1] #include <linux/init.h> int __initdata foo; int get_foo(void) { return foo; } If you compile it with ARM versatile_defconfig, modpost will show the symbol name, (unknown). WARNING: modpost: vmlinux.o: section mismatch in reference: get_foo (section: .text) -> (unknown) (section: .init.data) (You need to use GNU linker instead of LLD to reproduce it.) If you compile it for other architectures, modpost will show the correct symbol name. WARNING: modpost: vmlinux.o: section mismatch in reference: get_foo (section: .text) -> foo (section: .init.data) For R_ARM_ABS32, addend_arm_rel() sets r->r_addend to a wrong value. I just mimicked the code in arch/arm/kernel/module.c. However, there is more difficulty for ARM. Here, test code. [test code 2] #include <linux/init.h> int __initdata foo; int get_foo(void) { return foo; } int __initdata bar; int get_bar(void) { return bar; } With this commit applied, modpost will show the following messages for ARM versatile_defconfig: WARNING: modpost: vmlinux.o: section mismatch in reference: get_foo (section: .text) -> foo (section: .init.data) WARNING: modpost: vmlinux.o: section mismatch in reference: get_bar (section: .text) -> foo (section: .init.data) The reference from 'get_bar' to 'foo' seems wrong. I have no solution for this because it is true in assembly level. In the following output, relocation at 0x1c is no longer associated with 'bar'. The two relocation entries point to the same symbol, and the offset to 'bar' is encoded in the instruction 'r0, [r3, #4]'. Disassembly of section .text: 00000000 <get_foo>: 0: e59f3004 ldr r3, [pc, #4] @ c <get_foo+0xc> 4: e5930000 ldr r0, [r3] 8: e12fff1e bx lr c: 00000000 .word 0x00000000 00000010 <get_bar>: 10: e59f3004 ldr r3, [pc, #4] @ 1c <get_bar+0xc> 14: e5930004 ldr r0, [r3, #4] 18: e12fff1e bx lr 1c: 00000000 .word 0x00000000 Relocation section '.rel.text' at offset 0x244 contains 2 entries: Offset Info Type Sym.Value Sym. Name 0000000c 00000c02 R_ARM_ABS32 00000000 .init.data 0000001c 00000c02 R_ARM_ABS32 00000000 .init.data When find_elf_symbol() gets into a situation where relsym->st_name is zero, there is no guarantee to get the symbol name as written in C. I am keeping the current logic because it is useful in many architectures, but the symbol name is not always correct depending on the optimization. I left some comments in find_tosym(). Fixes: 56a974f ("kbuild: make better section mismatch reports on arm") Signed-off-by: Masahiro Yamada <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
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[ Upstream commit f06cf1e ] vduse_vdpa_set_vq_affinity callback can be called with NULL value as cpu_mask when deleting the vduse device. This patch resets virtqueue's IRQ affinity mask value to set all CPUs instead of dereferencing NULL cpu_mask. [ 4760.952149] BUG: kernel NULL pointer dereference, address: 0000000000000000 [ 4760.959110] #PF: supervisor read access in kernel mode [ 4760.964247] #PF: error_code(0x0000) - not-present page [ 4760.969385] PGD 0 P4D 0 [ 4760.971927] Oops: 0000 [#1] PREEMPT SMP PTI [ 4760.976112] CPU: 13 PID: 2346 Comm: vdpa Not tainted 6.4.0-rc6+ #4 [ 4760.982291] Hardware name: Dell Inc. PowerEdge R640/0W23H8, BIOS 2.8.1 06/26/2020 [ 4760.989769] RIP: 0010:memcpy_orig+0xc5/0x130 [ 4760.994049] Code: 16 f8 4c 89 07 4c 89 4f 08 4c 89 54 17 f0 4c 89 5c 17 f8 c3 cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 83 fa 08 72 1b <4c> 8b 06 4c 8b 4c 16 f8 4c 89 07 4c 89 4c 17 f8 c3 cc cc cc cc 66 [ 4761.012793] RSP: 0018:ffffb1d565abb830 EFLAGS: 00010246 [ 4761.018020] RAX: ffff9f4bf6b27898 RBX: ffff9f4be23969c0 RCX: ffff9f4bcadf6400 [ 4761.025152] RDX: 0000000000000008 RSI: 0000000000000000 RDI: ffff9f4bf6b27898 [ 4761.032286] RBP: 0000000000000000 R08: 0000000000000008 R09: 0000000000000000 [ 4761.039416] R10: 0000000000000000 R11: 0000000000000600 R12: 0000000000000000 [ 4761.046549] R13: 0000000000000000 R14: 0000000000000080 R15: ffffb1d565abbb10 [ 4761.053680] FS: 00007f64c2ec2740(0000) GS:ffff9f635f980000(0000) knlGS:0000000000000000 [ 4761.061765] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 4761.067513] CR2: 0000000000000000 CR3: 0000001875270006 CR4: 00000000007706e0 [ 4761.074645] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 4761.081775] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 4761.088909] PKRU: 55555554 [ 4761.091620] Call Trace: [ 4761.094074] <TASK> [ 4761.096180] ? __die+0x1f/0x70 [ 4761.099238] ? page_fault_oops+0x171/0x4f0 [ 4761.103340] ? exc_page_fault+0x7b/0x180 [ 4761.107265] ? asm_exc_page_fault+0x22/0x30 [ 4761.111460] ? memcpy_orig+0xc5/0x130 [ 4761.115126] vduse_vdpa_set_vq_affinity+0x3e/0x50 [vduse] [ 4761.120533] virtnet_clean_affinity.part.0+0x3d/0x90 [virtio_net] [ 4761.126635] remove_vq_common+0x1a4/0x250 [virtio_net] [ 4761.131781] virtnet_remove+0x5d/0x70 [virtio_net] [ 4761.136580] virtio_dev_remove+0x3a/0x90 [ 4761.140509] device_release_driver_internal+0x19b/0x200 [ 4761.145742] bus_remove_device+0xc2/0x130 [ 4761.149755] device_del+0x158/0x3e0 [ 4761.153245] ? kernfs_find_ns+0x35/0xc0 [ 4761.157086] device_unregister+0x13/0x60 [ 4761.161010] unregister_virtio_device+0x11/0x20 [ 4761.165543] device_release_driver_internal+0x19b/0x200 [ 4761.170770] bus_remove_device+0xc2/0x130 [ 4761.174782] device_del+0x158/0x3e0 [ 4761.178276] ? __pfx_vdpa_name_match+0x10/0x10 [vdpa] [ 4761.183336] device_unregister+0x13/0x60 [ 4761.187260] vdpa_nl_cmd_dev_del_set_doit+0x63/0xe0 [vdpa] Fixes: 28f6288 ("vduse: Support set_vq_affinity callback") Cc: [email protected] Signed-off-by: Maxime Coquelin <[email protected]> Message-Id: <[email protected]> Signed-off-by: Michael S. Tsirkin <[email protected]> Acked-by: Jason Wang <[email protected]> Reviewed-by: Xie Yongji <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
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…ed variables commit 6018b58 upstream. Hist triggers can have referenced variables without having direct variables fields. This can be the case if referenced variables are added for trigger actions. In this case the newly added references will not have field variables. Not taking such referenced variables into consideration can result in a bug where it would be possible to remove hist trigger with variables being refenced. This will result in a bug that is easily reproducable like so $ cd /sys/kernel/tracing $ echo 'synthetic_sys_enter char[] comm; long id' >> synthetic_events $ echo 'hist:keys=common_pid.execname,id.syscall:vals=hitcount:comm=common_pid.execname' >> events/raw_syscalls/sys_enter/trigger $ echo 'hist:keys=common_pid.execname,id.syscall:onmatch(raw_syscalls.sys_enter).synthetic_sys_enter($comm, id)' >> events/raw_syscalls/sys_enter/trigger $ echo '!hist:keys=common_pid.execname,id.syscall:vals=hitcount:comm=common_pid.execname' >> events/raw_syscalls/sys_enter/trigger [ 100.263533] ================================================================== [ 100.264634] BUG: KASAN: slab-use-after-free in resolve_var_refs+0xc7/0x180 [ 100.265520] Read of size 8 at addr ffff88810375d0f0 by task bash/439 [ 100.266320] [ 100.266533] CPU: 2 PID: 439 Comm: bash Not tainted 6.5.0-rc1 #4 [ 100.267277] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-20220807_005459-localhost 04/01/2014 [ 100.268561] Call Trace: [ 100.268902] <TASK> [ 100.269189] dump_stack_lvl+0x4c/0x70 [ 100.269680] print_report+0xc5/0x600 [ 100.270165] ? resolve_var_refs+0xc7/0x180 [ 100.270697] ? kasan_complete_mode_report_info+0x80/0x1f0 [ 100.271389] ? resolve_var_refs+0xc7/0x180 [ 100.271913] kasan_report+0xbd/0x100 [ 100.272380] ? resolve_var_refs+0xc7/0x180 [ 100.272920] __asan_load8+0x71/0xa0 [ 100.273377] resolve_var_refs+0xc7/0x180 [ 100.273888] event_hist_trigger+0x749/0x860 [ 100.274505] ? kasan_save_stack+0x2a/0x50 [ 100.275024] ? kasan_set_track+0x29/0x40 [ 100.275536] ? __pfx_event_hist_trigger+0x10/0x10 [ 100.276138] ? ksys_write+0xd1/0x170 [ 100.276607] ? do_syscall_64+0x3c/0x90 [ 100.277099] ? entry_SYSCALL_64_after_hwframe+0x6e/0xd8 [ 100.277771] ? destroy_hist_data+0x446/0x470 [ 100.278324] ? event_hist_trigger_parse+0xa6c/0x3860 [ 100.278962] ? __pfx_event_hist_trigger_parse+0x10/0x10 [ 100.279627] ? __kasan_check_write+0x18/0x20 [ 100.280177] ? mutex_unlock+0x85/0xd0 [ 100.280660] ? __pfx_mutex_unlock+0x10/0x10 [ 100.281200] ? kfree+0x7b/0x120 [ 100.281619] ? ____kasan_slab_free+0x15d/0x1d0 [ 100.282197] ? event_trigger_write+0xac/0x100 [ 100.282764] ? __kasan_slab_free+0x16/0x20 [ 100.283293] ? __kmem_cache_free+0x153/0x2f0 [ 100.283844] ? sched_mm_cid_remote_clear+0xb1/0x250 [ 100.284550] ? __pfx_sched_mm_cid_remote_clear+0x10/0x10 [ 100.285221] ? event_trigger_write+0xbc/0x100 [ 100.285781] ? __kasan_check_read+0x15/0x20 [ 100.286321] ? __bitmap_weight+0x66/0xa0 [ 100.286833] ? _find_next_bit+0x46/0xe0 [ 100.287334] ? task_mm_cid_work+0x37f/0x450 [ 100.287872] event_triggers_call+0x84/0x150 [ 100.288408] trace_event_buffer_commit+0x339/0x430 [ 100.289073] ? ring_buffer_event_data+0x3f/0x60 [ 100.292189] trace_event_raw_event_sys_enter+0x8b/0xe0 [ 100.295434] syscall_trace_enter.constprop.0+0x18f/0x1b0 [ 100.298653] syscall_enter_from_user_mode+0x32/0x40 [ 100.301808] do_syscall_64+0x1a/0x90 [ 100.304748] entry_SYSCALL_64_after_hwframe+0x6e/0xd8 [ 100.307775] RIP: 0033:0x7f686c75c1cb [ 100.310617] Code: 73 01 c3 48 8b 0d 65 3c 10 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa b8 21 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 35 3c 10 00 f7 d8 64 89 01 48 [ 100.317847] RSP: 002b:00007ffc60137a38 EFLAGS: 00000246 ORIG_RAX: 0000000000000021 [ 100.321200] RAX: ffffffffffffffda RBX: 000055f566469ea0 RCX: 00007f686c75c1cb [ 100.324631] RDX: 0000000000000001 RSI: 0000000000000001 RDI: 000000000000000a [ 100.328104] RBP: 00007ffc60137ac0 R08: 00007f686c818460 R09: 000000000000000a [ 100.331509] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000009 [ 100.334992] R13: 0000000000000007 R14: 000000000000000a R15: 0000000000000007 [ 100.338381] </TASK> We hit the bug because when second hist trigger has was created has_hist_vars() returned false because hist trigger did not have variables. As a result of that save_hist_vars() was not called to add the trigger to trace_array->hist_vars. Later on when we attempted to remove the first histogram find_any_var_ref() failed to detect it is being used because it did not find the second trigger in hist_vars list. With this change we wait until trigger actions are created so we can take into consideration if hist trigger has variable references. Also, now we check the return value of save_hist_vars() and fail trigger creation if save_hist_vars() fails. Link: https://lore.kernel.org/linux-trace-kernel/[email protected] Cc: [email protected] Fixes: 067fe03 ("tracing: Add variable reference handling to hist triggers") Signed-off-by: Mohamed Khalfella <[email protected]> Signed-off-by: Steven Rostedt (Google) <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
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When scanning namespaces, it is possible to get valid data from the first call to nvme_identify_ns() in nvme_alloc_ns(), but not from the second call in nvme_update_ns_info_block(). In particular, if the NSID becomes inactive between the two commands, a storage device may return a buffer filled with zero as per 4.1.5.1. In this case, we can get a kernel crash due to a divide-by-zero in blk_stack_limits() because ns->lba_shift will be set to zero. PID: 326 TASK: ffff95fec3cd8000 CPU: 29 COMMAND: "kworker/u98:10" #0 [ffffad8f8702f9e0] machine_kexec at ffffffff91c76ec7 #1 [ffffad8f8702fa38] __crash_kexec at ffffffff91dea4fa #2 [ffffad8f8702faf8] crash_kexec at ffffffff91deb788 #3 [ffffad8f8702fb00] oops_end at ffffffff91c2e4bb #4 [ffffad8f8702fb20] do_trap at ffffffff91c2a4ce #5 [ffffad8f8702fb70] do_error_trap at ffffffff91c2a595 #6 [ffffad8f8702fbb0] exc_divide_error at ffffffff928506e6 #7 [ffffad8f8702fbd0] asm_exc_divide_error at ffffffff92a00926 [exception RIP: blk_stack_limits+434] RIP: ffffffff92191872 RSP: ffffad8f8702fc80 RFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff95efa0c91800 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001 RBP: 00000000ffffffff R8: ffff95fec7df35a8 R9: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: ffff95fed33c09a8 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #8 [ffffad8f8702fce0] nvme_update_ns_info_block at ffffffffc06d3533 [nvme_core] grate-driver#9 [ffffad8f8702fd18] nvme_scan_ns at ffffffffc06d6fa7 [nvme_core] This happened when the check for valid data was moved out of nvme_identify_ns() into one of the callers. Fix this by checking in both callers. Link: https://bugzilla.kernel.org/show_bug.cgi?id=218186 Fixes: 0dd6fff ("nvme: bring back auto-removal of deleted namespaces during sequential scan") Cc: [email protected] Signed-off-by: Ewan D. Milne <[email protected]> Signed-off-by: Keith Busch <[email protected]>
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Currently the dp_display_request_irq() is executed at msm_dp_modeset_init() which ties irq registering to the DPU device's life cycle, while depending on resources that are released as the DP device is torn down. Move register DP driver irq handler to dp_display_probe() to have dp_display_irq_handler() IRQ tied with DP device. In addition, use platform_get_irq() to retrieve irq number from platform device directly. Changes in v5: -- reworded commit text as review comments at change #4 -- tear down component if failed at dp_display_request_irq() Changes in v4: -- delete dp->irq check at dp_display_request_irq() Changes in v3: -- move calling dp_display_irq_handler() to probe Signed-off-by: Kuogee Hsieh <[email protected]> Reviewed-by: Dmitry Baryshkov <[email protected]>
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The is_connected flag is set to true after DP mainlink successfully finishes link training to enter into ST_MAINLINK_READY state rather than being set after the DP dongle is connected. Rename the is_connected flag with link_ready flag to match the state of DP driver's state machine. Changes in v5: -- reworded commit text according to review comments from change #4 Changes in v4: -- reworded commit text Signed-off-by: Kuogee Hsieh <[email protected]> Reviewed-by: Dmitry Baryshkov <[email protected]>
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… place apply_alternatives() treats alternatives with the ALT_FLAG_NOT flag set special as it optimizes the existing NOPs in place. Unfortunately, this happens with interrupts enabled and does not provide any form of core synchronization. So an interrupt hitting in the middle of the update and using the affected code path will observe a half updated NOP and crash and burn. The following 3 NOP sequence was observed to expose this crash halfway reliably under QEMU 32bit: 0x90 0x90 0x90 which is replaced by the optimized 3 byte NOP: 0x8d 0x76 0x00 So an interrupt can observe: 1) 0x90 0x90 0x90 nop nop nop 2) 0x8d 0x90 0x90 undefined 3) 0x8d 0x76 0x90 lea -0x70(%esi),%esi 4) 0x8d 0x76 0x00 lea 0x0(%esi),%esi Where only #1 and #4 are true NOPs. The same problem exists for 64bit obviously. Disable interrupts around this NOP optimization and invoke sync_core() before re-enabling them. Fixes: 270a69c ("x86/alternative: Support relocations in alternatives") Reported-by: Paul Gortmaker <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Signed-off-by: Borislav Petkov (AMD) <[email protected]> Acked-by: Peter Zijlstra (Intel) <[email protected]> Cc: [email protected] Link: https://lore.kernel.org/r/ZT6narvE%2BLxX%[email protected]
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Patch series "Multi-size THP for anonymous memory", v9. A series to implement multi-size THP (mTHP) for anonymous memory (previously called "small-sized THP" and "large anonymous folios"). The objective of this is to improve performance by allocating larger chunks of memory during anonymous page faults: 1) Since SW (the kernel) is dealing with larger chunks of memory than base pages, there are efficiency savings to be had; fewer page faults, batched PTE and RMAP manipulation, reduced lru list, etc. In short, we reduce kernel overhead. This should benefit all architectures. 2) Since we are now mapping physically contiguous chunks of memory, we can take advantage of HW TLB compression techniques. A reduction in TLB pressure speeds up kernel and user space. arm64 systems have 2 mechanisms to coalesce TLB entries; "the contiguous bit" (architectural) and HPA (uarch). This version incorporates David's feedback on the core patches (#3, #4) and adds some RB and TB tags (see change log for details). By default, the existing behaviour (and performance) is maintained. The user must explicitly enable multi-size THP to see the performance benefit. This is done via a new sysfs interface (as recommended by David Hildenbrand - thanks to David for the suggestion)! This interface is inspired by the existing per-hugepage-size sysfs interface used by hugetlb, provides full backwards compatibility with the existing PMD-size THP interface, and provides a base for future extensibility. See [9] for detailed discussion of the interface. This series is based on mm-unstable (715b67adf4c8). Prerequisites ============= I'm removing this section on the basis that I don't believe what we were previously calling prerequisites are really prerequisites anymore. We originally defined them when mTHP was a compile-time feature. There is now a runtime control to opt-in to mTHP; when disabled, correctness and performance are as before. When enabled, the code is still correct/robust, but in the absence of the one remaining item (compaction) there may be a performance impact in some corners. See the old list in the v8 cover letter at [8]. And a longer explanation of my thinking here [10]. SUMMARY: I don't think we should hold this series up, waiting for the items on the prerequisites list. I believe this series should be ready now so hopefully can be added to mm-unstable for some testing, then fingers crossed for v6.8. Testing ======= The series includes patches for mm selftests to enlighten the cow and khugepaged tests to explicitly test with multi-size THP, in the same way that PMD-sized THP is tested. The new tests all pass, and no regressions are observed in the mm selftest suite. I've also run my usual kernel compilation and java script benchmarks without any issues. Refer to my performance numbers posted with v6 [6]. (These are for multi-size THP only - they do not include the arm64 contpte follow-on series). John Hubbard at Nvidia has indicated dramatic 10x performance improvements for some workloads at [11]. (Observed using v6 of this series as well as the arm64 contpte series). Kefeng Wang at Huawei has also indicated he sees improvements at [12] although there are some latency regressions also. I've also checked that there is no regression in the write fault path when mTHP is disabled using a microbenchmark. I ran it for a baseline kernel, as well as v8 and v9. I repeated on Ampere Altra (bare metal) and Apple M2 (VM): | | m2 vm | altra | |--------------|---------------------|---------------------| | kernel | mean | std_rel | mean | std_rel | |--------------|----------|----------|----------|----------| | baseline | 0.000% | 0.341% | 0.000% | 3.581% | | anonfolio-v8 | 0.005% | 0.272% | 5.068% | 1.128% | | anonfolio-v9 | -0.013% | 0.442% | 0.107% | 1.788% | There is no measurable difference on M2, but altra has a slow down in v8 which is fixed in v9 by moving the THP order check to be inline within thp_vma_allowable_orders(), as suggested by David. This patch (of 10): In preparation for the introduction of anonymous multi-size THP, we would like to be able to split them when they have unmapped subpages, in order to free those unused pages under memory pressure. So remove the artificial requirement that the large folio needed to be at least PMD-sized. Link: https://lkml.kernel.org/r/[email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ryan Roberts <[email protected]> Reviewed-by: Yu Zhao <[email protected]> Reviewed-by: Yin Fengwei <[email protected]> Reviewed-by: Matthew Wilcox (Oracle) <[email protected]> Reviewed-by: David Hildenbrand <[email protected]> Reviewed-by: Barry Song <[email protected]> Tested-by: Kefeng Wang <[email protected]> Tested-by: John Hubbard <[email protected]> Cc: Alistair Popple <[email protected]> Cc: Anshuman Khandual <[email protected]> Cc: Catalin Marinas <[email protected]> Cc: David Rientjes <[email protected]> Cc: "Huang, Ying" <[email protected]> Cc: Hugh Dickins <[email protected]> Cc: Itaru Kitayama <[email protected]> Cc: Kirill A. Shutemov <[email protected]> Cc: Luis Chamberlain <[email protected]> Cc: Vlastimil Babka <[email protected]> Cc: Yang Shi <[email protected]> Cc: Zi Yan <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
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Jiri Pirko says: ==================== devlink: introduce notifications filtering From: Jiri Pirko <[email protected]> Currently the user listening on a socket for devlink notifications gets always all messages for all existing devlink instances and objects, even if he is interested only in one of those. That may cause unnecessary overhead on setups with thousands of instances present. User is currently able to narrow down the devlink objects replies to dump commands by specifying select attributes. Allow similar approach for notifications providing user a new notify-filter-set command to select attributes with values the notification message has to match. In that case, it is delivered to the socket. Note that the filtering is done per-socket, so multiple users may specify different selection of attributes with values. This patchset initially introduces support for following attributes: DEVLINK_ATTR_BUS_NAME DEVLINK_ATTR_DEV_NAME DEVLINK_ATTR_PORT_INDEX Patches #1 - #4 are preparations in devlink code, patch #3 is an optimization done on the way. Patches #5 - #7 are preparations in netlink and generic netlink code. Patch #8 is the main one in this set implementing of the notify-filter-set command and the actual per-socket filtering. Patch grate-driver#9 extends the infrastructure allowing to filter according to a port index. Example: $ devlink mon port pci/0000:08:00.0/32768 [port,new] pci/0000:08:00.0/32768: type notset flavour pcisf controller 0 pfnum 0 sfnum 107 splittable false function: hw_addr 00:00:00:00:00:00 state inactive opstate detached roce enable [port,new] pci/0000:08:00.0/32768: type eth flavour pcisf controller 0 pfnum 0 sfnum 107 splittable false function: hw_addr 00:00:00:00:00:00 state inactive opstate detached roce enable [port,new] pci/0000:08:00.0/32768: type eth netdev eth3 flavour pcisf controller 0 pfnum 0 sfnum 107 splittable false function: hw_addr 00:00:00:00:00:00 state inactive opstate detached roce enable [port,new] pci/0000:08:00.0/32768: type eth netdev eth3 flavour pcisf controller 0 pfnum 0 sfnum 107 splittable false function: hw_addr 00:00:00:00:00:00 state inactive opstate detached roce enable [port,new] pci/0000:08:00.0/32768: type eth flavour pcisf controller 0 pfnum 0 sfnum 107 splittable false function: hw_addr 00:00:00:00:00:00 state inactive opstate detached roce enable [port,new] pci/0000:08:00.0/32768: type notset flavour pcisf controller 0 pfnum 0 sfnum 107 splittable false function: hw_addr 00:00:00:00:00:00 state inactive opstate detached roce enable [port,del] pci/0000:08:00.0/32768: type notset flavour pcisf controller 0 pfnum 0 sfnum 107 splittable false function: hw_addr 00:00:00:00:00:00 state inactive opstate detached roce enable ==================== Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Paolo Abeni <[email protected]>
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Ido Schimmel says: ==================== Add MDB bulk deletion support This patchset adds MDB bulk deletion support, allowing user space to request the deletion of matching entries instead of dumping the entire MDB and issuing a separate deletion request for each matching entry. Support is added in both the bridge and VXLAN drivers in a similar fashion to the existing FDB bulk deletion support. The parameters according to which bulk deletion can be performed are similar to the FDB ones, namely: Destination port, VLAN ID, state (e.g., "permanent"), routing protocol, source / destination VNI, destination IP and UDP port. Flushing based on flags (e.g., "offload", "fast_leave", "added_by_star_ex", "blocked") is not currently supported, but can be added in the future, if a use case arises. Patch #1 adds a new uAPI attribute to allow specifying the state mask according to which bulk deletion will be performed, if any. Patch #2 adds a new policy according to which bulk deletion requests (with 'NLM_F_BULK' flag set) will be parsed. Patches #3-#4 add a new NDO for MDB bulk deletion and invoke it from the rtnetlink code when a bulk deletion request is made. Patches #5-#6 implement the MDB bulk deletion NDO in the bridge and VXLAN drivers, respectively. Patch #7 allows user space to issue MDB bulk deletion requests by no longer rejecting the 'NLM_F_BULK' flag when it is set in 'RTM_DELMDB' requests. Patches #8-grate-driver#9 add selftests for both drivers, for both good and bad flows. iproute2 changes can be found here [1]. https:/idosch/iproute2/tree/submit/mdb_flush_v1 ==================== Signed-off-by: David S. Miller <[email protected]>
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Patch series "Multi-size THP for anonymous memory", v9. A series to implement multi-size THP (mTHP) for anonymous memory (previously called "small-sized THP" and "large anonymous folios"). The objective of this is to improve performance by allocating larger chunks of memory during anonymous page faults: 1) Since SW (the kernel) is dealing with larger chunks of memory than base pages, there are efficiency savings to be had; fewer page faults, batched PTE and RMAP manipulation, reduced lru list, etc. In short, we reduce kernel overhead. This should benefit all architectures. 2) Since we are now mapping physically contiguous chunks of memory, we can take advantage of HW TLB compression techniques. A reduction in TLB pressure speeds up kernel and user space. arm64 systems have 2 mechanisms to coalesce TLB entries; "the contiguous bit" (architectural) and HPA (uarch). This version incorporates David's feedback on the core patches (#3, #4) and adds some RB and TB tags (see change log for details). By default, the existing behaviour (and performance) is maintained. The user must explicitly enable multi-size THP to see the performance benefit. This is done via a new sysfs interface (as recommended by David Hildenbrand - thanks to David for the suggestion)! This interface is inspired by the existing per-hugepage-size sysfs interface used by hugetlb, provides full backwards compatibility with the existing PMD-size THP interface, and provides a base for future extensibility. See [9] for detailed discussion of the interface. This series is based on mm-unstable (715b67adf4c8). Prerequisites ============= I'm removing this section on the basis that I don't believe what we were previously calling prerequisites are really prerequisites anymore. We originally defined them when mTHP was a compile-time feature. There is now a runtime control to opt-in to mTHP; when disabled, correctness and performance are as before. When enabled, the code is still correct/robust, but in the absence of the one remaining item (compaction) there may be a performance impact in some corners. See the old list in the v8 cover letter at [8]. And a longer explanation of my thinking here [10]. SUMMARY: I don't think we should hold this series up, waiting for the items on the prerequisites list. I believe this series should be ready now so hopefully can be added to mm-unstable for some testing, then fingers crossed for v6.8. Testing ======= The series includes patches for mm selftests to enlighten the cow and khugepaged tests to explicitly test with multi-size THP, in the same way that PMD-sized THP is tested. The new tests all pass, and no regressions are observed in the mm selftest suite. I've also run my usual kernel compilation and java script benchmarks without any issues. Refer to my performance numbers posted with v6 [6]. (These are for multi-size THP only - they do not include the arm64 contpte follow-on series). John Hubbard at Nvidia has indicated dramatic 10x performance improvements for some workloads at [11]. (Observed using v6 of this series as well as the arm64 contpte series). Kefeng Wang at Huawei has also indicated he sees improvements at [12] although there are some latency regressions also. I've also checked that there is no regression in the write fault path when mTHP is disabled using a microbenchmark. I ran it for a baseline kernel, as well as v8 and v9. I repeated on Ampere Altra (bare metal) and Apple M2 (VM): | | m2 vm | altra | |--------------|---------------------|---------------------| | kernel | mean | std_rel | mean | std_rel | |--------------|----------|----------|----------|----------| | baseline | 0.000% | 0.341% | 0.000% | 3.581% | | anonfolio-v8 | 0.005% | 0.272% | 5.068% | 1.128% | | anonfolio-v9 | -0.013% | 0.442% | 0.107% | 1.788% | There is no measurable difference on M2, but altra has a slow down in v8 which is fixed in v9 by moving the THP order check to be inline within thp_vma_allowable_orders(), as suggested by David. This patch (of 10): In preparation for the introduction of anonymous multi-size THP, we would like to be able to split them when they have unmapped subpages, in order to free those unused pages under memory pressure. So remove the artificial requirement that the large folio needed to be at least PMD-sized. Link: https://lkml.kernel.org/r/[email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ryan Roberts <[email protected]> Reviewed-by: Yu Zhao <[email protected]> Reviewed-by: Yin Fengwei <[email protected]> Reviewed-by: Matthew Wilcox (Oracle) <[email protected]> Reviewed-by: David Hildenbrand <[email protected]> Reviewed-by: Barry Song <[email protected]> Tested-by: Kefeng Wang <[email protected]> Tested-by: John Hubbard <[email protected]> Cc: Alistair Popple <[email protected]> Cc: Anshuman Khandual <[email protected]> Cc: Catalin Marinas <[email protected]> Cc: David Rientjes <[email protected]> Cc: "Huang, Ying" <[email protected]> Cc: Hugh Dickins <[email protected]> Cc: Itaru Kitayama <[email protected]> Cc: Kirill A. Shutemov <[email protected]> Cc: Luis Chamberlain <[email protected]> Cc: Vlastimil Babka <[email protected]> Cc: Yang Shi <[email protected]> Cc: Zi Yan <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
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Trying to suspend to RAM on SAMA5D27 EVK leads to the following lockdep
warning:
============================================
WARNING: possible recursive locking detected
6.7.0-rc5-wt+ #532 Not tainted
--------------------------------------------
sh/92 is trying to acquire lock:
c3cf306c (&irq_desc_lock_class){-.-.}-{2:2}, at: __irq_get_desc_lock+0xe8/0x100
but task is already holding lock:
c3d7c46c (&irq_desc_lock_class){-.-.}-{2:2}, at: __irq_get_desc_lock+0xe8/0x100
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&irq_desc_lock_class);
lock(&irq_desc_lock_class);
*** DEADLOCK ***
May be due to missing lock nesting notation
6 locks held by sh/92:
#0: c3aa0258 (sb_writers#6){.+.+}-{0:0}, at: ksys_write+0xd8/0x178
#1: c4c2df44 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x138/0x284
#2: c32684a0 (kn->active){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x148/0x284
#3: c232b6d4 (system_transition_mutex){+.+.}-{3:3}, at: pm_suspend+0x13c/0x4e8
#4: c387b088 (&dev->mutex){....}-{3:3}, at: __device_suspend+0x1e8/0x91c
#5: c3d7c46c (&irq_desc_lock_class){-.-.}-{2:2}, at: __irq_get_desc_lock+0xe8/0x100
stack backtrace:
CPU: 0 PID: 92 Comm: sh Not tainted 6.7.0-rc5-wt+ #532
Hardware name: Atmel SAMA5
unwind_backtrace from show_stack+0x18/0x1c
show_stack from dump_stack_lvl+0x34/0x48
dump_stack_lvl from __lock_acquire+0x19ec/0x3a0c
__lock_acquire from lock_acquire.part.0+0x124/0x2d0
lock_acquire.part.0 from _raw_spin_lock_irqsave+0x5c/0x78
_raw_spin_lock_irqsave from __irq_get_desc_lock+0xe8/0x100
__irq_get_desc_lock from irq_set_irq_wake+0xa8/0x204
irq_set_irq_wake from atmel_gpio_irq_set_wake+0x58/0xb4
atmel_gpio_irq_set_wake from irq_set_irq_wake+0x100/0x204
irq_set_irq_wake from gpio_keys_suspend+0xec/0x2b8
gpio_keys_suspend from dpm_run_callback+0xe4/0x248
dpm_run_callback from __device_suspend+0x234/0x91c
__device_suspend from dpm_suspend+0x224/0x43c
dpm_suspend from dpm_suspend_start+0x9c/0xa8
dpm_suspend_start from suspend_devices_and_enter+0x1e0/0xa84
suspend_devices_and_enter from pm_suspend+0x460/0x4e8
pm_suspend from state_store+0x78/0xe4
state_store from kernfs_fop_write_iter+0x1a0/0x284
kernfs_fop_write_iter from vfs_write+0x38c/0x6f4
vfs_write from ksys_write+0xd8/0x178
ksys_write from ret_fast_syscall+0x0/0x1c
Exception stack(0xc52b3fa8 to 0xc52b3ff0)
3fa0: 00000004 005a0ae8 00000001 005a0ae8 00000004 00000001
3fc0: 00000004 005a0ae8 00000001 00000004 00000004 b6c616c0 00000020 0059d190
3fe0: 00000004 b6c61678 aec5a041 aebf1a26
This warning is raised because pinctrl-at91-pio4 uses chained IRQ. Whenever
a wake up source configures an IRQ through irq_set_irq_wake, it will
lock the corresponding IRQ desc, and then call irq_set_irq_wake on "parent"
IRQ which will do the same on its own IRQ desc, but since those two locks
share the same class, lockdep reports this as an issue.
Fix lockdep false positive by setting a different class for parent and
children IRQ
Fixes: 7761808 ("pinctrl: introduce driver for Atmel PIO4 controller")
Signed-off-by: Alexis Lothoré <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Linus Walleij <[email protected]>
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An issue occurred while reading an ELF file in libbpf.c during fuzzing: Program received signal SIGSEGV, Segmentation fault. 0x0000000000958e97 in bpf_object.collect_prog_relos () at libbpf.c:4206 4206 in libbpf.c (gdb) bt #0 0x0000000000958e97 in bpf_object.collect_prog_relos () at libbpf.c:4206 #1 0x000000000094f9d6 in bpf_object.collect_relos () at libbpf.c:6706 #2 0x000000000092bef3 in bpf_object_open () at libbpf.c:7437 #3 0x000000000092c046 in bpf_object.open_mem () at libbpf.c:7497 #4 0x0000000000924afa in LLVMFuzzerTestOneInput () at fuzz/bpf-object-fuzzer.c:16 #5 0x000000000060be11 in testblitz_engine::fuzzer::Fuzzer::run_one () #6 0x000000000087ad92 in tracing::span::Span::in_scope () #7 0x00000000006078aa in testblitz_engine::fuzzer::util::walkdir () #8 0x00000000005f3217 in testblitz_engine::entrypoint::main::{{closure}} () grate-driver#9 0x00000000005f2601 in main () (gdb) scn_data was null at this code(tools/lib/bpf/src/libbpf.c): if (rel->r_offset % BPF_INSN_SZ || rel->r_offset >= scn_data->d_size) { The scn_data is derived from the code above: scn = elf_sec_by_idx(obj, sec_idx); scn_data = elf_sec_data(obj, scn); relo_sec_name = elf_sec_str(obj, shdr->sh_name); sec_name = elf_sec_name(obj, scn); if (!relo_sec_name || !sec_name)// don't check whether scn_data is NULL return -EINVAL; In certain special scenarios, such as reading a malformed ELF file, it is possible that scn_data may be a null pointer Signed-off-by: Mingyi Zhang <[email protected]> Signed-off-by: Xin Liu <[email protected]> Signed-off-by: Changye Wu <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Acked-by: Daniel Borkmann <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
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…mplaint [ Upstream commit bbaa6ff ] AMD PMF driver can cause the following warning: [ 196.159546] ------------[ cut here ]------------ [ 196.159556] Voluntary context switch within RCU read-side critical section! [ 196.159571] WARNING: CPU: 0 PID: 9 at kernel/rcu/tree_plugin.h:320 rcu_note_context_switch+0x43d/0x560 [ 196.159604] Modules linked in: nvme_fabrics ccm rfcomm snd_hda_scodec_cs35l41_spi cmac algif_hash algif_skcipher af_alg bnep joydev btusb btrtl uvcvideo btintel btbcm videobuf2_vmalloc intel_rapl_msr btmtk videobuf2_memops uvc videobuf2_v4l2 intel_rapl_common binfmt_misc hid_sensor_als snd_sof_amd_vangogh hid_sensor_trigger bluetooth industrialio_triggered_buffer videodev snd_sof_amd_rembrandt hid_sensor_iio_common amdgpu ecdh_generic kfifo_buf videobuf2_common hp_wmi kvm_amd sparse_keymap snd_sof_amd_renoir wmi_bmof industrialio ecc mc nls_iso8859_1 kvm snd_sof_amd_acp irqbypass snd_sof_xtensa_dsp crct10dif_pclmul crc32_pclmul mt7921e snd_sof_pci snd_ctl_led polyval_clmulni mt7921_common polyval_generic snd_sof ghash_clmulni_intel mt792x_lib mt76_connac_lib sha512_ssse3 snd_sof_utils aesni_intel snd_hda_codec_realtek crypto_simd mt76 snd_hda_codec_generic cryptd snd_soc_core snd_hda_codec_hdmi rapl ledtrig_audio input_leds snd_compress i2c_algo_bit drm_ttm_helper mac80211 snd_pci_ps hid_multitouch ttm drm_exec [ 196.159970] drm_suballoc_helper snd_rpl_pci_acp6x amdxcp drm_buddy snd_hda_intel snd_acp_pci snd_hda_scodec_cs35l41_i2c serio_raw gpu_sched snd_hda_scodec_cs35l41 snd_acp_legacy_common snd_intel_dspcfg snd_hda_cs_dsp_ctls snd_hda_codec libarc4 drm_display_helper snd_pci_acp6x cs_dsp snd_hwdep snd_soc_cs35l41_lib video k10temp snd_pci_acp5x thunderbolt snd_hda_core drm_kms_helper cfg80211 snd_seq snd_rn_pci_acp3x snd_pcm snd_acp_config cec snd_soc_acpi snd_seq_device rc_core ccp snd_pci_acp3x snd_timer snd soundcore wmi amd_pmf platform_profile amd_pmc mac_hid serial_multi_instantiate wireless_hotkey hid_sensor_hub sch_fq_codel msr parport_pc ppdev lp parport efi_pstore ip_tables x_tables autofs4 btrfs blake2b_generic raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx libcrc32c xor raid6_pq raid1 raid0 multipath linear dm_mirror dm_region_hash dm_log cdc_ether usbnet r8152 mii hid_generic nvme i2c_hid_acpi i2c_hid nvme_core i2c_piix4 xhci_pci amd_sfh drm xhci_pci_renesas nvme_common hid [ 196.160382] CPU: 0 PID: 9 Comm: kworker/0:1 Not tainted 6.6.0-rc1 #4 [ 196.160397] Hardware name: HP HP EliteBook 845 14 inch G10 Notebook PC/8B6E, BIOS V82 Ver. 01.02.00 08/24/2023 [ 196.160405] Workqueue: events power_supply_changed_work [ 196.160426] RIP: 0010:rcu_note_context_switch+0x43d/0x560 [ 196.160440] Code: 00 48 89 be 40 08 00 00 48 89 86 48 08 00 00 48 89 10 e9 63 fe ff ff 48 c7 c7 10 e7 b0 9e c6 05 e8 d8 20 02 01 e8 13 0f f3 ff <0f> 0b e9 27 fc ff ff a9 ff ff ff 7f 0f 84 cf fc ff ff 65 48 8b 3c [ 196.160450] RSP: 0018:ffffc900001878f0 EFLAGS: 00010046 [ 196.160462] RAX: 0000000000000000 RBX: ffff88885e834040 RCX: 0000000000000000 [ 196.160470] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 196.160476] RBP: ffffc90000187910 R08: 0000000000000000 R09: 0000000000000000 [ 196.160482] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 196.160488] R13: 0000000000000000 R14: ffff888100990000 R15: ffff888100990000 [ 196.160495] FS: 0000000000000000(0000) GS:ffff88885e800000(0000) knlGS:0000000000000000 [ 196.160504] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 196.160512] CR2: 000055cb053c8246 CR3: 000000013443a000 CR4: 0000000000750ef0 [ 196.160520] PKRU: 55555554 [ 196.160526] Call Trace: [ 196.160532] <TASK> [ 196.160548] ? show_regs+0x72/0x90 [ 196.160570] ? rcu_note_context_switch+0x43d/0x560 [ 196.160580] ? __warn+0x8d/0x160 [ 196.160600] ? rcu_note_context_switch+0x43d/0x560 [ 196.160613] ? report_bug+0x1bb/0x1d0 [ 196.160637] ? handle_bug+0x46/0x90 [ 196.160658] ? exc_invalid_op+0x19/0x80 [ 196.160675] ? asm_exc_invalid_op+0x1b/0x20 [ 196.160709] ? rcu_note_context_switch+0x43d/0x560 [ 196.160727] __schedule+0xb9/0x15f0 [ 196.160746] ? srso_alias_return_thunk+0x5/0x7f [ 196.160765] ? srso_alias_return_thunk+0x5/0x7f [ 196.160778] ? acpi_ns_search_one_scope+0xbe/0x270 [ 196.160806] schedule+0x68/0x110 [ 196.160820] schedule_timeout+0x151/0x160 [ 196.160829] ? srso_alias_return_thunk+0x5/0x7f [ 196.160842] ? srso_alias_return_thunk+0x5/0x7f [ 196.160855] ? acpi_ns_lookup+0x3c5/0xa90 [ 196.160878] __down_common+0xff/0x220 [ 196.160905] __down_timeout+0x16/0x30 [ 196.160920] down_timeout+0x64/0x70 [ 196.160938] acpi_os_wait_semaphore+0x85/0x200 [ 196.160959] acpi_ut_acquire_mutex+0x9e/0x280 [ 196.160979] acpi_ex_enter_interpreter+0x2d/0xb0 [ 196.160992] acpi_ns_evaluate+0x2f0/0x5f0 [ 196.161005] acpi_evaluate_object+0x172/0x490 [ 196.161018] ? acpi_os_signal_semaphore+0x8a/0xd0 [ 196.161038] acpi_evaluate_integer+0x52/0xe0 [ 196.161055] ? kfree+0x79/0x120 [ 196.161071] ? srso_alias_return_thunk+0x5/0x7f [ 196.161089] acpi_ac_get_state.part.0+0x27/0x80 [ 196.161110] get_ac_property+0x5c/0x70 [ 196.161127] ? __pfx___power_supply_is_system_supplied+0x10/0x10 [ 196.161146] __power_supply_is_system_supplied+0x44/0xb0 [ 196.161166] class_for_each_device+0x124/0x160 [ 196.161184] ? acpi_ac_get_state.part.0+0x27/0x80 [ 196.161203] ? srso_alias_return_thunk+0x5/0x7f [ 196.161223] power_supply_is_system_supplied+0x3c/0x70 [ 196.161243] amd_pmf_get_power_source+0xe/0x20 [amd_pmf] [ 196.161276] amd_pmf_power_slider_update_event+0x49/0x90 [amd_pmf] [ 196.161310] amd_pmf_pwr_src_notify_call+0xe7/0x100 [amd_pmf] [ 196.161340] notifier_call_chain+0x5f/0xe0 [ 196.161362] atomic_notifier_call_chain+0x33/0x60 [ 196.161378] power_supply_changed_work+0x84/0x110 [ 196.161394] process_one_work+0x178/0x360 [ 196.161412] ? __pfx_worker_thread+0x10/0x10 [ 196.161424] worker_thread+0x307/0x430 [ 196.161440] ? __pfx_worker_thread+0x10/0x10 [ 196.161451] kthread+0xf4/0x130 [ 196.161467] ? __pfx_kthread+0x10/0x10 [ 196.161486] ret_from_fork+0x43/0x70 [ 196.161502] ? __pfx_kthread+0x10/0x10 [ 196.161518] ret_from_fork_asm+0x1b/0x30 [ 196.161558] </TASK> [ 196.161562] ---[ end trace 0000000000000000 ]--- Since there's no guarantee that all the callbacks can work in atomic context, switch to use blocking_notifier_call_chain to relax the constraint. Signed-off-by: Kai-Heng Feng <[email protected]> Reported-by: Allen Zhong <[email protected]> Fixes: 4c71ae4 ("platform/x86/amd/pmf: Add support SPS PMF feature") Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217571 Reviewed-by: Mario Limonciello <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Sebastian Reichel <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
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[ Upstream commit a84fbf2 ] Generating metrics llc_code_read_mpi_demand_plus_prefetch, llc_data_read_mpi_demand_plus_prefetch, llc_miss_local_memory_bandwidth_read, llc_miss_local_memory_bandwidth_write, nllc_miss_remote_memory_bandwidth_read, memory_bandwidth_read, memory_bandwidth_write, uncore_frequency, upi_data_transmit_bw, C2_Pkg_Residency, C3_Core_Residency, C3_Pkg_Residency, C6_Core_Residency, C6_Pkg_Residency, C7_Core_Residency, C7_Pkg_Residency, UNCORE_FREQ and tma_info_system_socket_clks would trigger an address sanitizer heap-buffer-overflows on a SkylakeX. ``` ==2567752==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x5020003ed098 at pc 0x5621a816654e bp 0x7fffb55d4da0 sp 0x7fffb55d4d98 READ of size 4 at 0x5020003eee78 thread T0 #0 0x558265d6654d in aggr_cpu_id__is_empty tools/perf/util/cpumap.c:694:12 #1 0x558265c914da in perf_stat__get_aggr tools/perf/builtin-stat.c:1490:6 #2 0x558265c914da in perf_stat__get_global_cached tools/perf/builtin-stat.c:1530:9 #3 0x558265e53290 in should_skip_zero_counter tools/perf/util/stat-display.c:947:31 #4 0x558265e53290 in print_counter_aggrdata tools/perf/util/stat-display.c:985:18 #5 0x558265e51931 in print_counter tools/perf/util/stat-display.c:1110:3 #6 0x558265e51931 in evlist__print_counters tools/perf/util/stat-display.c:1571:5 #7 0x558265c8ec87 in print_counters tools/perf/builtin-stat.c:981:2 #8 0x558265c8cc71 in cmd_stat tools/perf/builtin-stat.c:2837:3 grate-driver#9 0x558265bb9bd4 in run_builtin tools/perf/perf.c:323:11 grate-driver#10 0x558265bb98eb in handle_internal_command tools/perf/perf.c:377:8 grate-driver#11 0x558265bb9389 in run_argv tools/perf/perf.c:421:2 grate-driver#12 0x558265bb9389 in main tools/perf/perf.c:537:3 ``` The issue was the use of testing a cpumap with NULL rather than using empty, as a map containing the dummy value isn't NULL and the -1 results in an empty aggr map being allocated which legitimately overflows when any member is accessed. Fixes: 8a96f45 ("perf stat: Avoid SEGV if core.cpus isn't set") Signed-off-by: Ian Rogers <[email protected]> Acked-by: Namhyung Kim <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Ian Rogers <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Peter Zijlstra <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
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[ Upstream commit ede72dc ] Fuzzing found that an invalid tracepoint name would create a memory leak with an address sanitizer build: ``` $ perf stat -e '*:o/' true event syntax error: '*:o/' \___ parser error Run 'perf list' for a list of valid events Usage: perf stat [<options>] [<command>] -e, --event <event> event selector. use 'perf list' to list available events ================================================================= ==59380==ERROR: LeakSanitizer: detected memory leaks Direct leak of 4 byte(s) in 2 object(s) allocated from: #0 0x7f38ac07077b in __interceptor_strdup ../../../../src/libsanitizer/asan/asan_interceptors.cpp:439 #1 0x55f2f41be73b in str util/parse-events.l:49 #2 0x55f2f41d08e8 in parse_events_lex util/parse-events.l:338 #3 0x55f2f41dc3b1 in parse_events_parse util/parse-events-bison.c:1464 #4 0x55f2f410b8b3 in parse_events__scanner util/parse-events.c:1822 #5 0x55f2f410d1b9 in __parse_events util/parse-events.c:2094 #6 0x55f2f410e57f in parse_events_option util/parse-events.c:2279 #7 0x55f2f4427b56 in get_value tools/lib/subcmd/parse-options.c:251 #8 0x55f2f4428d98 in parse_short_opt tools/lib/subcmd/parse-options.c:351 grate-driver#9 0x55f2f4429d80 in parse_options_step tools/lib/subcmd/parse-options.c:539 grate-driver#10 0x55f2f442acb9 in parse_options_subcommand tools/lib/subcmd/parse-options.c:654 grate-driver#11 0x55f2f3ec99fc in cmd_stat tools/perf/builtin-stat.c:2501 grate-driver#12 0x55f2f4093289 in run_builtin tools/perf/perf.c:322 grate-driver#13 0x55f2f40937f5 in handle_internal_command tools/perf/perf.c:375 grate-driver#14 0x55f2f4093bbd in run_argv tools/perf/perf.c:419 grate-driver#15 0x55f2f409412b in main tools/perf/perf.c:535 SUMMARY: AddressSanitizer: 4 byte(s) leaked in 2 allocation(s). ``` Fix by adding the missing destructor. Fixes: 865582c ("perf tools: Adds the tracepoint name parsing support") Signed-off-by: Ian Rogers <[email protected]> Cc: He Kuang <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Namhyung Kim <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
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commit 5a22fbc upstream. When LAN9303 is MDIO-connected two callchains exist into mdio->bus->write(): 1. switch ports 1&2 ("physical" PHYs): virtual (switch-internal) MDIO bus (lan9303_switch_ops->phy_{read|write})-> lan9303_mdio_phy_{read|write} -> mdiobus_{read|write}_nested 2. LAN9303 virtual PHY: virtual MDIO bus (lan9303_phy_{read|write}) -> lan9303_virt_phy_reg_{read|write} -> regmap -> lan9303_mdio_{read|write} If the latter functions just take mutex_lock(&sw_dev->device->bus->mdio_lock) it triggers a LOCKDEP false-positive splat. It's false-positive because the first mdio_lock in the second callchain above belongs to virtual MDIO bus, the second mdio_lock belongs to physical MDIO bus. Consequent annotation in lan9303_mdio_{read|write} as nested lock (similar to lan9303_mdio_phy_{read|write}, it's the same physical MDIO bus) prevents the following splat: WARNING: possible circular locking dependency detected 5.15.71 #1 Not tainted ------------------------------------------------------ kworker/u4:3/609 is trying to acquire lock: ffff000011531c68 (lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock){+.+.}-{3:3}, at: regmap_lock_mutex but task is already holding lock: ffff0000114c44d8 (&bus->mdio_lock){+.+.}-{3:3}, at: mdiobus_read which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&bus->mdio_lock){+.+.}-{3:3}: lock_acquire __mutex_lock mutex_lock_nested lan9303_mdio_read _regmap_read regmap_read lan9303_probe lan9303_mdio_probe mdio_probe really_probe __driver_probe_device driver_probe_device __device_attach_driver bus_for_each_drv __device_attach device_initial_probe bus_probe_device deferred_probe_work_func process_one_work worker_thread kthread ret_from_fork -> #0 (lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock){+.+.}-{3:3}: __lock_acquire lock_acquire.part.0 lock_acquire __mutex_lock mutex_lock_nested regmap_lock_mutex regmap_read lan9303_phy_read dsa_slave_phy_read __mdiobus_read mdiobus_read get_phy_device mdiobus_scan __mdiobus_register dsa_register_switch lan9303_probe lan9303_mdio_probe mdio_probe really_probe __driver_probe_device driver_probe_device __device_attach_driver bus_for_each_drv __device_attach device_initial_probe bus_probe_device deferred_probe_work_func process_one_work worker_thread kthread ret_from_fork other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&bus->mdio_lock); lock(lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock); lock(&bus->mdio_lock); lock(lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock); *** DEADLOCK *** 5 locks held by kworker/u4:3/609: #0: ffff000002842938 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work #1: ffff80000bacbd60 (deferred_probe_work){+.+.}-{0:0}, at: process_one_work #2: ffff000007645178 (&dev->mutex){....}-{3:3}, at: __device_attach #3: ffff8000096e6e78 (dsa2_mutex){+.+.}-{3:3}, at: dsa_register_switch #4: ffff0000114c44d8 (&bus->mdio_lock){+.+.}-{3:3}, at: mdiobus_read stack backtrace: CPU: 1 PID: 609 Comm: kworker/u4:3 Not tainted 5.15.71 #1 Workqueue: events_unbound deferred_probe_work_func Call trace: dump_backtrace show_stack dump_stack_lvl dump_stack print_circular_bug check_noncircular __lock_acquire lock_acquire.part.0 lock_acquire __mutex_lock mutex_lock_nested regmap_lock_mutex regmap_read lan9303_phy_read dsa_slave_phy_read __mdiobus_read mdiobus_read get_phy_device mdiobus_scan __mdiobus_register dsa_register_switch lan9303_probe lan9303_mdio_probe ... Cc: [email protected] Fixes: dc70058 ("net: dsa: LAN9303: add MDIO managed mode support") Signed-off-by: Alexander Sverdlin <[email protected]> Reviewed-by: Andrew Lunn <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Paolo Abeni <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
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commit d8b90d6 upstream. When scanning namespaces, it is possible to get valid data from the first call to nvme_identify_ns() in nvme_alloc_ns(), but not from the second call in nvme_update_ns_info_block(). In particular, if the NSID becomes inactive between the two commands, a storage device may return a buffer filled with zero as per 4.1.5.1. In this case, we can get a kernel crash due to a divide-by-zero in blk_stack_limits() because ns->lba_shift will be set to zero. PID: 326 TASK: ffff95fec3cd8000 CPU: 29 COMMAND: "kworker/u98:10" #0 [ffffad8f8702f9e0] machine_kexec at ffffffff91c76ec7 #1 [ffffad8f8702fa38] __crash_kexec at ffffffff91dea4fa #2 [ffffad8f8702faf8] crash_kexec at ffffffff91deb788 #3 [ffffad8f8702fb00] oops_end at ffffffff91c2e4bb #4 [ffffad8f8702fb20] do_trap at ffffffff91c2a4ce #5 [ffffad8f8702fb70] do_error_trap at ffffffff91c2a595 #6 [ffffad8f8702fbb0] exc_divide_error at ffffffff928506e6 #7 [ffffad8f8702fbd0] asm_exc_divide_error at ffffffff92a00926 [exception RIP: blk_stack_limits+434] RIP: ffffffff92191872 RSP: ffffad8f8702fc80 RFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff95efa0c91800 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001 RBP: 00000000ffffffff R8: ffff95fec7df35a8 R9: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: ffff95fed33c09a8 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #8 [ffffad8f8702fce0] nvme_update_ns_info_block at ffffffffc06d3533 [nvme_core] grate-driver#9 [ffffad8f8702fd18] nvme_scan_ns at ffffffffc06d6fa7 [nvme_core] This happened when the check for valid data was moved out of nvme_identify_ns() into one of the callers. Fix this by checking in both callers. Link: https://bugzilla.kernel.org/show_bug.cgi?id=218186 Fixes: 0dd6fff ("nvme: bring back auto-removal of deleted namespaces during sequential scan") Cc: [email protected] Signed-off-by: Ewan D. Milne <[email protected]> Signed-off-by: Keith Busch <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
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[ Upstream commit e3e82fc ] When creating ceq_0 during probing irdma, cqp.sc_cqp will be sent as a cqp_request to cqp->sc_cqp.sq_ring. If the request is pending when removing the irdma driver or unplugging its aux device, cqp.sc_cqp will be dereferenced as wrong struct in irdma_free_pending_cqp_request(). PID: 3669 TASK: ffff88aef892c000 CPU: 28 COMMAND: "kworker/28:0" #0 [fffffe0000549e38] crash_nmi_callback at ffffffff810e3a34 #1 [fffffe0000549e40] nmi_handle at ffffffff810788b2 #2 [fffffe0000549ea0] default_do_nmi at ffffffff8107938f #3 [fffffe0000549eb8] do_nmi at ffffffff81079582 #4 [fffffe0000549ef0] end_repeat_nmi at ffffffff82e016b4 [exception RIP: native_queued_spin_lock_slowpath+1291] RIP: ffffffff8127e72b RSP: ffff88aa841ef778 RFLAGS: 00000046 RAX: 0000000000000000 RBX: ffff88b01f849700 RCX: ffffffff8127e47e RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff83857ec0 RBP: ffff88afe3e4efc8 R8: ffffed15fc7c9dfa R9: ffffed15fc7c9dfa R10: 0000000000000001 R11: ffffed15fc7c9df9 R12: 0000000000740000 R13: ffff88b01f849708 R14: 0000000000000003 R15: ffffed1603f092e1 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0000 -- <NMI exception stack> -- #5 [ffff88aa841ef778] native_queued_spin_lock_slowpath at ffffffff8127e72b #6 [ffff88aa841ef7b0] _raw_spin_lock_irqsave at ffffffff82c22aa4 #7 [ffff88aa841ef7c8] __wake_up_common_lock at ffffffff81257363 #8 [ffff88aa841ef888] irdma_free_pending_cqp_request at ffffffffa0ba12cc [irdma] grate-driver#9 [ffff88aa841ef958] irdma_cleanup_pending_cqp_op at ffffffffa0ba1469 [irdma] grate-driver#10 [ffff88aa841ef9c0] irdma_ctrl_deinit_hw at ffffffffa0b2989f [irdma] grate-driver#11 [ffff88aa841efa28] irdma_remove at ffffffffa0b252df [irdma] grate-driver#12 [ffff88aa841efae8] auxiliary_bus_remove at ffffffff8219afdb grate-driver#13 [ffff88aa841efb00] device_release_driver_internal at ffffffff821882e6 grate-driver#14 [ffff88aa841efb38] bus_remove_device at ffffffff82184278 grate-driver#15 [ffff88aa841efb88] device_del at ffffffff82179d23 grate-driver#16 [ffff88aa841efc48] ice_unplug_aux_dev at ffffffffa0eb1c14 [ice] grate-driver#17 [ffff88aa841efc68] ice_service_task at ffffffffa0d88201 [ice] grate-driver#18 [ffff88aa841efde8] process_one_work at ffffffff811c589a grate-driver#19 [ffff88aa841efe60] worker_thread at ffffffff811c71ff grate-driver#20 [ffff88aa841eff10] kthread at ffffffff811d87a0 grate-driver#21 [ffff88aa841eff50] ret_from_fork at ffffffff82e0022f Fixes: 44d9e52 ("RDMA/irdma: Implement device initialization definitions") Link: https://lore.kernel.org/r/[email protected] Suggested-by: "Ismail, Mustafa" <[email protected]> Signed-off-by: Shifeng Li <[email protected]> Reviewed-by: Shiraz Saleem <[email protected]> Signed-off-by: Jason Gunthorpe <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
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commit 7fed14f upstream. The following warning appears when using buffered events: [ 203.556451] WARNING: CPU: 53 PID: 10220 at kernel/trace/ring_buffer.c:3912 ring_buffer_discard_commit+0x2eb/0x420 [...] [ 203.670690] CPU: 53 PID: 10220 Comm: stress-ng-sysin Tainted: G E 6.7.0-rc2-default #4 56e6d0fcf5581e6e51eaaecbdaec2a2338c80f3a [ 203.670704] Hardware name: Intel Corp. GROVEPORT/GROVEPORT, BIOS GVPRCRB1.86B.0016.D04.1705030402 05/03/2017 [ 203.670709] RIP: 0010:ring_buffer_discard_commit+0x2eb/0x420 [ 203.735721] Code: 4c 8b 4a 50 48 8b 42 48 49 39 c1 0f 84 b3 00 00 00 49 83 e8 01 75 b1 48 8b 42 10 f0 ff 40 08 0f 0b e9 fc fe ff ff f0 ff 47 08 <0f> 0b e9 77 fd ff ff 48 8b 42 10 f0 ff 40 08 0f 0b e9 f5 fe ff ff [ 203.735734] RSP: 0018:ffffb4ae4f7b7d80 EFLAGS: 00010202 [ 203.735745] RAX: 0000000000000000 RBX: ffffb4ae4f7b7de0 RCX: ffff8ac10662c000 [ 203.735754] RDX: ffff8ac0c750be00 RSI: ffff8ac10662c000 RDI: ffff8ac0c004d400 [ 203.781832] RBP: ffff8ac0c039cea0 R08: 0000000000000000 R09: 0000000000000000 [ 203.781839] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 203.781842] R13: ffff8ac10662c000 R14: ffff8ac0c004d400 R15: ffff8ac10662c008 [ 203.781846] FS: 00007f4cd8a67740(0000) GS:ffff8ad798880000(0000) knlGS:0000000000000000 [ 203.781851] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 203.781855] CR2: 0000559766a74028 CR3: 00000001804c4000 CR4: 00000000001506f0 [ 203.781862] Call Trace: [ 203.781870] <TASK> [ 203.851949] trace_event_buffer_commit+0x1ea/0x250 [ 203.851967] trace_event_raw_event_sys_enter+0x83/0xe0 [ 203.851983] syscall_trace_enter.isra.0+0x182/0x1a0 [ 203.851990] do_syscall_64+0x3a/0xe0 [ 203.852075] entry_SYSCALL_64_after_hwframe+0x6e/0x76 [ 203.852090] RIP: 0033:0x7f4cd870fa77 [ 203.982920] Code: 00 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 90 b8 89 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e9 43 0e 00 f7 d8 64 89 01 48 [ 203.982932] RSP: 002b:00007fff99717dd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000089 [ 203.982942] RAX: ffffffffffffffda RBX: 0000558ea1d7b6f0 RCX: 00007f4cd870fa77 [ 203.982948] RDX: 0000000000000000 RSI: 00007fff99717de0 RDI: 0000558ea1d7b6f0 [ 203.982957] RBP: 00007fff99717de0 R08: 00007fff997180e0 R09: 00007fff997180e0 [ 203.982962] R10: 00007fff997180e0 R11: 0000000000000246 R12: 00007fff99717f40 [ 204.049239] R13: 00007fff99718590 R14: 0000558e9f2127a8 R15: 00007fff997180b0 [ 204.049256] </TASK> For instance, it can be triggered by running these two commands in parallel: $ while true; do echo hist:key=id.syscall:val=hitcount > \ /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/trigger; done $ stress-ng --sysinfo $(nproc) The warning indicates that the current ring_buffer_per_cpu is not in the committing state. It happens because the active ring_buffer_event doesn't actually come from the ring_buffer_per_cpu but is allocated from trace_buffered_event. The bug is in function trace_buffered_event_disable() where the following normally happens: * The code invokes disable_trace_buffered_event() via smp_call_function_many() and follows it by synchronize_rcu(). This increments the per-CPU variable trace_buffered_event_cnt on each target CPU and grants trace_buffered_event_disable() the exclusive access to the per-CPU variable trace_buffered_event. * Maintenance is performed on trace_buffered_event, all per-CPU event buffers get freed. * The code invokes enable_trace_buffered_event() via smp_call_function_many(). This decrements trace_buffered_event_cnt and releases the access to trace_buffered_event. A problem is that smp_call_function_many() runs a given function on all target CPUs except on the current one. The following can then occur: * Task X executing trace_buffered_event_disable() runs on CPU 0. * The control reaches synchronize_rcu() and the task gets rescheduled on another CPU 1. * The RCU synchronization finishes. At this point, trace_buffered_event_disable() has the exclusive access to all trace_buffered_event variables except trace_buffered_event[CPU0] because trace_buffered_event_cnt[CPU0] is never incremented and if the buffer is currently unused, remains set to 0. * A different task Y is scheduled on CPU 0 and hits a trace event. The code in trace_event_buffer_lock_reserve() sees that trace_buffered_event_cnt[CPU0] is set to 0 and decides the use the buffer provided by trace_buffered_event[CPU0]. * Task X continues its execution in trace_buffered_event_disable(). The code incorrectly frees the event buffer pointed by trace_buffered_event[CPU0] and resets the variable to NULL. * Task Y writes event data to the now freed buffer and later detects the created inconsistency. The issue is observable since commit dea4997 ("tracing: Fix warning in trace_buffered_event_disable()") which moved the call of trace_buffered_event_disable() in __ftrace_event_enable_disable() earlier, prior to invoking call->class->reg(.. TRACE_REG_UNREGISTER ..). The underlying problem in trace_buffered_event_disable() is however present since the original implementation in commit 0fc1b09 ("tracing: Use temp buffer when filtering events"). Fix the problem by replacing the two smp_call_function_many() calls with on_each_cpu_mask() which invokes a given callback on all CPUs. Link: https://lore.kernel.org/all/[email protected]/ Link: https://lkml.kernel.org/r/[email protected] Cc: [email protected] Fixes: 0fc1b09 ("tracing: Use temp buffer when filtering events") Fixes: dea4997 ("tracing: Fix warning in trace_buffered_event_disable()") Signed-off-by: Petr Pavlu <[email protected]> Signed-off-by: Steven Rostedt (Google) <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
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Jan 7, 2024
commit fe2b122 upstream. When working on LED support for r8169 I got the following lockdep warning. Easiest way to prevent this scenario seems to be to take the RTNL lock before the trigger_data lock in set_device_name(). ====================================================== WARNING: possible circular locking dependency detected 6.7.0-rc2-next-20231124+ #2 Not tainted ------------------------------------------------------ bash/383 is trying to acquire lock: ffff888103aa1c68 (&trigger_data->lock){+.+.}-{3:3}, at: netdev_trig_notify+0xec/0x190 [ledtrig_netdev] but task is already holding lock: ffffffff8cddf808 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x12/0x20 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (rtnl_mutex){+.+.}-{3:3}: __mutex_lock+0x9b/0xb50 mutex_lock_nested+0x16/0x20 rtnl_lock+0x12/0x20 set_device_name+0xa9/0x120 [ledtrig_netdev] netdev_trig_activate+0x1a1/0x230 [ledtrig_netdev] led_trigger_set+0x172/0x2c0 led_trigger_write+0xf1/0x140 sysfs_kf_bin_write+0x5d/0x80 kernfs_fop_write_iter+0x15d/0x210 vfs_write+0x1f0/0x510 ksys_write+0x6c/0xf0 __x64_sys_write+0x14/0x20 do_syscall_64+0x3f/0xf0 entry_SYSCALL_64_after_hwframe+0x6c/0x74 -> #0 (&trigger_data->lock){+.+.}-{3:3}: __lock_acquire+0x1459/0x25a0 lock_acquire+0xc8/0x2d0 __mutex_lock+0x9b/0xb50 mutex_lock_nested+0x16/0x20 netdev_trig_notify+0xec/0x190 [ledtrig_netdev] call_netdevice_register_net_notifiers+0x5a/0x100 register_netdevice_notifier+0x85/0x120 netdev_trig_activate+0x1d4/0x230 [ledtrig_netdev] led_trigger_set+0x172/0x2c0 led_trigger_write+0xf1/0x140 sysfs_kf_bin_write+0x5d/0x80 kernfs_fop_write_iter+0x15d/0x210 vfs_write+0x1f0/0x510 ksys_write+0x6c/0xf0 __x64_sys_write+0x14/0x20 do_syscall_64+0x3f/0xf0 entry_SYSCALL_64_after_hwframe+0x6c/0x74 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(rtnl_mutex); lock(&trigger_data->lock); lock(rtnl_mutex); lock(&trigger_data->lock); *** DEADLOCK *** 8 locks held by bash/383: #0: ffff888103ff33f0 (sb_writers#3){.+.+}-{0:0}, at: ksys_write+0x6c/0xf0 #1: ffff888103aa1e88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x114/0x210 #2: ffff8881036f1890 (kn->active#82){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x11d/0x210 #3: ffff888108e2c358 (&led_cdev->led_access){+.+.}-{3:3}, at: led_trigger_write+0x30/0x140 #4: ffffffff8cdd9e10 (triggers_list_lock){++++}-{3:3}, at: led_trigger_write+0x75/0x140 #5: ffff888108e2c270 (&led_cdev->trigger_lock){++++}-{3:3}, at: led_trigger_write+0xe3/0x140 #6: ffffffff8cdde3d0 (pernet_ops_rwsem){++++}-{3:3}, at: register_netdevice_notifier+0x1c/0x120 #7: ffffffff8cddf808 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x12/0x20 stack backtrace: CPU: 0 PID: 383 Comm: bash Not tainted 6.7.0-rc2-next-20231124+ #2 Hardware name: Default string Default string/Default string, BIOS ADLN.M6.SODIMM.ZB.CY.015 08/08/2023 Call Trace: <TASK> dump_stack_lvl+0x5c/0xd0 dump_stack+0x10/0x20 print_circular_bug+0x2dd/0x410 check_noncircular+0x131/0x150 __lock_acquire+0x1459/0x25a0 lock_acquire+0xc8/0x2d0 ? netdev_trig_notify+0xec/0x190 [ledtrig_netdev] __mutex_lock+0x9b/0xb50 ? netdev_trig_notify+0xec/0x190 [ledtrig_netdev] ? __this_cpu_preempt_check+0x13/0x20 ? netdev_trig_notify+0xec/0x190 [ledtrig_netdev] ? __cancel_work_timer+0x11c/0x1b0 ? __mutex_lock+0x123/0xb50 mutex_lock_nested+0x16/0x20 ? mutex_lock_nested+0x16/0x20 netdev_trig_notify+0xec/0x190 [ledtrig_netdev] call_netdevice_register_net_notifiers+0x5a/0x100 register_netdevice_notifier+0x85/0x120 netdev_trig_activate+0x1d4/0x230 [ledtrig_netdev] led_trigger_set+0x172/0x2c0 ? preempt_count_add+0x49/0xc0 led_trigger_write+0xf1/0x140 sysfs_kf_bin_write+0x5d/0x80 kernfs_fop_write_iter+0x15d/0x210 vfs_write+0x1f0/0x510 ksys_write+0x6c/0xf0 __x64_sys_write+0x14/0x20 do_syscall_64+0x3f/0xf0 entry_SYSCALL_64_after_hwframe+0x6c/0x74 RIP: 0033:0x7f269055d034 Code: c7 00 16 00 00 00 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 80 3d 35 c3 0d 00 00 74 13 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 48 83 ec 28 48 89 54 24 18 48 RSP: 002b:00007ffddb7ef748 EFLAGS: 00000202 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000007 RCX: 00007f269055d034 RDX: 0000000000000007 RSI: 000055bf5f4af3c0 RDI: 0000000000000001 RBP: 000055bf5f4af3c0 R08: 0000000000000073 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000007 R13: 00007f26906325c0 R14: 00007f269062ff20 R15: 0000000000000000 </TASK> Fixes: d5e0126 ("leds: trigger: netdev: add additional specific link speed mode") Cc: [email protected] Signed-off-by: Heiner Kallweit <[email protected]> Reviewed-by: Andrew Lunn <[email protected]> Acked-by: Lee Jones <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Jakub Kicinski <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
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