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| author | Suren Baghdasaryan <surenb@google.com> | 2024-11-29 16:14:23 -0800 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2024-12-18 19:04:46 -0800 |
| commit | 60da7445a142bd15e67f3cda915497781c3f781f (patch) | |
| tree | 016fd09dd9f3d308131bf34771bbe7d49cdf2768 /include | |
| parent | e269b5d2916d7a696c2d2ed370cea95d95a0675a (diff) | |
| download | lwn-60da7445a142bd15e67f3cda915497781c3f781f.tar.gz lwn-60da7445a142bd15e67f3cda915497781c3f781f.zip | |
alloc_tag: fix set_codetag_empty() when !CONFIG_MEM_ALLOC_PROFILING_DEBUG
It was recently noticed that set_codetag_empty() might be used not only to
mark NULL alloctag references as empty to avoid warnings but also to reset
valid tags (in clear_page_tag_ref()). Since set_codetag_empty() is
defined as NOOP for CONFIG_MEM_ALLOC_PROFILING_DEBUG=n, such use of
set_codetag_empty() leads to subtle bugs. Fix set_codetag_empty() for
CONFIG_MEM_ALLOC_PROFILING_DEBUG=n to reset the tag reference.
Link: https://lkml.kernel.org/r/20241130001423.1114965-2-surenb@google.com
Fixes: a8fc28dad6d5 ("alloc_tag: introduce clear_page_tag_ref() helper function")
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reported-by: David Wang <00107082@163.com>
Closes: https://lore.kernel.org/lkml/20241124074318.399027-1-00107082@163.com/
Cc: David Wang <00107082@163.com>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Sourav Panda <souravpanda@google.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/alloc_tag.h | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/include/linux/alloc_tag.h b/include/linux/alloc_tag.h index cba024bf2db3..0bbbe537c5f9 100644 --- a/include/linux/alloc_tag.h +++ b/include/linux/alloc_tag.h @@ -63,7 +63,12 @@ static inline void set_codetag_empty(union codetag_ref *ref) #else /* CONFIG_MEM_ALLOC_PROFILING_DEBUG */ static inline bool is_codetag_empty(union codetag_ref *ref) { return false; } -static inline void set_codetag_empty(union codetag_ref *ref) {} + +static inline void set_codetag_empty(union codetag_ref *ref) +{ + if (ref) + ref->ct = NULL; +} #endif /* CONFIG_MEM_ALLOC_PROFILING_DEBUG */ |