Commit a4671094 authored by Viller Hsiao's avatar Viller Hsiao Committed by Ralf Baechle

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: default avatarViller 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: default avatarRalf Baechle <ralf@linux-mips.org>
parent 86ca57b5
......@@ -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
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment