From: Suren Baghdasaryan Date: Sat, 30 Nov 2024 00:14:23 +0000 (-0800) Subject: alloc_tag: fix set_codetag_empty() when !CONFIG_MEM_ALLOC_PROFILING_DEBUG X-Git-Tag: xfs-zoned-2025-02-06~133^2~1 X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=60da7445a142bd15e67f3cda915497781c3f781f;p=users%2Fhch%2Fxfs.git 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 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 Cc: Mike Rapoport (Microsoft) Cc: Pasha Tatashin Cc: Sourav Panda Cc: Yu Zhao Cc: Signed-off-by: Andrew Morton --- 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 */