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| author | Peter Oberparleiter <oberpar@linux.ibm.com> | 2026-08-12 09:53:19 +0200 |
|---|---|---|
| committer | Vasily Gorbik <gor@linux.ibm.com> | 2026-08-13 16:56:45 +0200 |
| commit | 445c31ac638fd1af203d79bdf25fc0cb3149fbbc (patch) | |
| tree | d3a4cf633550be9ad94bff3310b1e1ff09716072 /scripts/patch-kernel | |
| parent | 337bd95507a16063687cfc286ea90de5cca48c37 (diff) | |
| download | linux-445c31ac638fd1af203d79bdf25fc0cb3149fbbc.tar.gz linux-445c31ac638fd1af203d79bdf25fc0cb3149fbbc.zip | |
s390/debug: Fix deadlock during unregister
Unregistering an s390dbf debug area while one of the associated debugfs
files is being written to can cause a deadlock:
$ echo >.../vmur/level $ rmmod vmur
===================================================
debugfs write
debugfs_file_get()
debug_unregister()
mutex_lock(debug_mutex)
debugfs_remove()
wait for debugfs_file_put()
debug_file_ops.write()
debug_input()
mutex_lock(debug_mutex) ==> DEADLOCK
Fix this by splitting debug_unregister() into an s390dbf and debugfs
part, and running only the s390dbf part with debug_mutex locked.
Fixes: 9372a82892c2 ("s390/debug: fix debug area life cycle")
Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Diffstat (limited to 'scripts/patch-kernel')
0 files changed, 0 insertions, 0 deletions