From: Thorsten Blum <thorsten.blum@linux.dev>
Date: Wed, 5 Mar 2025 12:31:34 +0000 (+0100)
Subject: perf/x86: Annotate struct bts_buffer::buf with __counted_by()
X-Git-Tag: v6.15-rc1~217^2~17
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=5e7adc81ae1b27ff565714d2933b291cf1e1271f;p=thirdparty%2Fkernel%2Flinux.git

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 8e09319544975..953868da82fb4 100644
--- 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;