From: Segher Boessenkool <segher@kernel.crashing.org>
To: linuxppc-dev@ozlabs.org
Subject: [PATCH] powerpc: Add attributes for setjmp/longjmp
Date: Wed, 4 Sep 2019 14:11:07 +0000 [thread overview]
Message-ID: <c02ce4a573f3bac907e2c70957a2d1275f910013.1567605586.git.segher@kernel.crashing.org> (raw)
The setjmp function should be declared as "returns_twice", or bad
things can happen[1]. This does not actually change generated code
in my testing.
The longjmp function should be declared as "noreturn", so that the
compiler can optimise calls to it better. This makes the generated
code a little shorter.
Signed-off-by: Segher Boessenkool <segher@kernel.crashing.org>
[1] See https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-returns_005ftwice-function-attribute
---
arch/powerpc/include/asm/setjmp.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/include/asm/setjmp.h b/arch/powerpc/include/asm/setjmp.h
index d995061..e9f81bb 100644
--- a/arch/powerpc/include/asm/setjmp.h
+++ b/arch/powerpc/include/asm/setjmp.h
@@ -7,7 +7,7 @@
#define JMP_BUF_LEN 23
-extern long setjmp(long *);
-extern void longjmp(long *, long);
+extern long setjmp(long *) __attribute__((returns_twice));
+extern void longjmp(long *, long) __attribute__((noreturn));
#endif /* _ASM_POWERPC_SETJMP_H */
--
1.8.3.1
next reply other threads:[~2019-09-04 14:24 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-04 14:11 Segher Boessenkool [this message]
2019-09-19 10:25 ` [PATCH] powerpc: Add attributes for setjmp/longjmp Michael Ellerman
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