perf/x86: Annotate struct bts_buffer::buf with __counted_by()

Add the __counted_by() compiler attribute to the flexible array member
buf to improve access bounds-checking via CONFIG_UBSAN_BOUNDS and
CONFIG_FORTIFY_SOURCE.

No functional changes intended.

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20250305123134.215577-2-thorsten.blum@linux.dev

diff --git a/arch/x86/events/intel/bts.c b/arch/x86/events/intel/bts.c
index 8e0931954497560cddf0ddb0718d207428610b6d..953868da82fb452d00db055d9082b4db905d7c2b 100644 (file)
--- a/arch/x86/events/intel/bts.c
+++ b/arch/x86/events/intel/bts.c
@@ -58,7 +58,7 @@ struct bts_buffer {
        local_t         head;
        unsigned long   end;
        void            **data_pages;
-       struct bts_phys buf[];
+       struct bts_phys buf[] __counted_by(nr_bufs);
 };
 
 static struct pmu bts_pmu;