diff options
| author | Dave Wysochanski <dwysocha@redhat.com> | 2021-10-01 15:37:31 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-10-02 10:03:28 -0700 |
| commit | 6e9bfdcf0a3b1c8126878c21adcfc343f89d4a6a (patch) | |
| tree | 5ecba2769543440629b34ce3a67c64c74f996ae5 | |
| parent | cdc1e6e225e3256d56dc6648411630e71d7c776b (diff) | |
cachefiles: Fix oops in trace_cachefiles_mark_buried due to NULL object
In cachefiles_mark_object_buried, the dentry in question may not have an
owner, and thus our cachefiles_object pointer may be NULL when calling
the tracepoint, in which case we will also not have a valid debug_id to
print in the tracepoint.
Check for NULL object in the tracepoint and if so, just set debug_id to
MAX_UINT as was done in 2908f5e101e3 ("fscache: Add a cookie debug ID
and use that in traces").
This fixes the following oops:
FS-Cache: Cache "mycache" added (type cachefiles)
CacheFiles: File cache on vdc registered
...
Workqueue: fscache_object fscache_object_work_func [fscache]
RIP: 0010:trace_event_raw_event_cachefiles_mark_buried+0x4e/0xa0 [cachefiles]
....
Call Trace:
cachefiles_mark_object_buried+0xa5/0xb0 [cachefiles]
cachefiles_bury_object+0x270/0x430 [cachefiles]
cachefiles_walk_to_object+0x195/0x9c0 [cachefiles]
cachefiles_lookup_object+0x5a/0xc0 [cachefiles]
fscache_look_up_object+0xd7/0x160 [fscache]
fscache_object_work_func+0xb2/0x340 [fscache]
process_one_work+0x1f1/0x390
worker_thread+0x53/0x3e0
kthread+0x127/0x150
Fixes: 2908f5e101e3 ("fscache: Add a cookie debug ID and use that in traces")
Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-cachefs@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | include/trace/events/cachefiles.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/trace/events/cachefiles.h b/include/trace/events/cachefiles.h index 9a448fe9355d..695bfdbfdcad 100644 --- a/include/trace/events/cachefiles.h +++ b/include/trace/events/cachefiles.h @@ -305,7 +305,7 @@ TRACE_EVENT(cachefiles_mark_buried, ), TP_fast_assign( - __entry->obj = obj->fscache.debug_id; + __entry->obj = obj ? obj->fscache.debug_id : UINT_MAX; __entry->de = de; __entry->why = why; ), |