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authorViller Hsiao <villerhsiao@gmail.com>2014-02-22 15:46:49 +0800
committerRalf Baechle <ralf@linux-mips.org>2014-03-17 15:42:07 +0100
commita4671094227d11985c06ee1178d7205c5fd39f8a (patch)
tree78e1b59f3b9803c1ac6e3ef702fdc2f3da06c969 /arch
parent86ca57b5a5525dbf89fc2a3285781fae807276b0 (diff)
downloadlinux-a4671094227d11985c06ee1178d7205c5fd39f8a.tar.bz2
MIPS: ftrace: Fix icache flush range error
In 32-bit mode, the start address passed to flush_icache_range is shifted by 4 bytes before the second safe_store_code() call. This causes system crash from time to time because the first 4 bytes might not be flushed properly. This bug exists since linux-3.8. Also remove obsoleted comment while at it. Signed-off-by: Viller Hsiao <villerhsiao@gmail.com> Cc: linux-mips@linux-mips.org Cc: rostedt@goodmis.org Cc: fweisbec@gmail.com Cc: mingo@redhat.com Cc: Qais.Yousef@imgtec.com Patchwork: https://patchwork.linux-mips.org/patch/6586/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/mips/kernel/ftrace.c5
1 files changed, 2 insertions, 3 deletions
diff --git a/arch/mips/kernel/ftrace.c b/arch/mips/kernel/ftrace.c
index 185ba258361b..374ed74cd516 100644
--- a/arch/mips/kernel/ftrace.c
+++ b/arch/mips/kernel/ftrace.c
@@ -111,11 +111,10 @@ static int ftrace_modify_code_2(unsigned long ip, unsigned int new_code1,
safe_store_code(new_code1, ip, faulted);
if (unlikely(faulted))
return -EFAULT;
- ip += 4;
- safe_store_code(new_code2, ip, faulted);
+ safe_store_code(new_code2, ip + 4, faulted);
if (unlikely(faulted))
return -EFAULT;
- flush_icache_range(ip, ip + 8); /* original ip + 12 */
+ flush_icache_range(ip, ip + 8);
return 0;
}
#endif