Hi Christophe,

On 26/08/22 15:48, Christophe Leroy wrote:

Le 08/08/2022 à 13:48, Sathvika Vasireddy a écrit :

quoted

objtool is throwing *unannotated intra-function call*
warnings with a few instructions that are marked
unreachable. Replace unreachable() with __builtin_unreachable()
to fix these warnings, as the codegen remains same
with unreachable() and __builtin_unreachable().

Signed-off-by: Sathvika Vasireddy <redacted>
---
   arch/powerpc/include/asm/bug.h | 2 +-
   1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/include/asm/bug.h b/arch/powerpc/include/asm/bug.h
index 61a4736355c2..074be1a78c56 100644
--- a/arch/powerpc/include/asm/bug.h
+++ b/arch/powerpc/include/asm/bug.h

@@ -99,7 +99,7 @@
   	__label__ __label_warn_on;				\
   								\
   	WARN_ENTRY("twi 31, 0, 0", BUGFLAG_WARNING | (flags), __label_warn_on); \
-	unreachable();						\
+	__builtin_unreachable();				\

Should you add barrier_before_unreachable() before
__builtin_unreachable() to avoid stack bombs ?

See commit 173a3efd3edb ("bug.h: work around GCC PR82365 in BUG()")

Yes, adding barrier_before_unreachable() before __builtin_unreachable()

works around the build issues reported at 
https://lkml.org/lkml/2022/8/25/418.

I'll post a v2 with this change.

Thanks for the suggestion!

- Sathvika


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel