lkml.org 
[lkml]   [2019]   [Aug]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] powerpc/futex: fix warning: 'oldval' may be used uninitialized in this function
Date
  CC      kernel/futex.o
kernel/futex.c: In function 'do_futex':
kernel/futex.c:1676:17: warning: 'oldval' may be used uninitialized in this function [-Wmaybe-uninitialized]
return oldval == cmparg;
^
kernel/futex.c:1651:6: note: 'oldval' was declared here
int oldval, ret;
^

This is because arch_futex_atomic_op_inuser() only sets *oval
if ret is NUL and GCC doesn't see that it will use it only when
ret is NUL.

Anyway, the non-NUL ret path is an error path that won't suffer from
setting *oval, and as *oval is a local var in futex_atomic_op_inuser()
it will have no impact.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
arch/powerpc/include/asm/futex.h | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/powerpc/include/asm/futex.h b/arch/powerpc/include/asm/futex.h
index 3a6aa57b9d90..eea28ca679db 100644
--- a/arch/powerpc/include/asm/futex.h
+++ b/arch/powerpc/include/asm/futex.h
@@ -60,8 +60,7 @@ static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval,

pagefault_enable();

- if (!ret)
- *oval = oldval;
+ *oval = oldval;

prevent_write_to_user(uaddr, sizeof(*uaddr));
return ret;
--
2.13.3
\
 
 \ /
  Last update: 2019-08-14 11:26    [W:0.048 / U:0.620 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site