The patch titled Subject: binfmt_misc: work around gcc-4.9 warning has been removed from the -mm tree. Its filename was binfmt_misc-work-around-gcc-49-warning.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Arnd Bergmann <arnd@xxxxxxxx> Subject: binfmt_misc: work around gcc-4.9 warning gcc-4.9 on ARM gives us a mysterious warning about the binfmt_misc parse_command function: fs/binfmt_misc.c: In function 'parse_command.part.3': fs/binfmt_misc.c:405:7: warning: array subscript is above array bounds [-Warray-bounds] I've managed to trace this back to the ARM implementation of memset, which is called from copy_from_user in case of a fault and which does #define memset(p,v,n) \ ({ \ void *__p = (p); size_t __n = n; \ if ((__n) != 0) { \ if (__builtin_constant_p((v)) && (v) == 0) \ __memzero((__p),(__n)); \ else \ memset((__p),(v),(__n)); \ } \ (__p); \ }) Apparently gcc gets confused by the check for "size != 0" and believes that the size might be zero when it gets to the line that does "if (s[count-1] == '\n')", so it would access data outside of the array. gcc is clearly wrong here, since this condition was already checked earlier in the function and the 'size' value can not change in the meantime. Fortunately, we can work around it and get rid of the warning by rearranging the function to check for zero size after doing the copy_from_user. It is still safe to pass a zero size into copy_from_user, so it does not cause any side effects. Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/binfmt_misc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff -puN fs/binfmt_misc.c~binfmt_misc-work-around-gcc-49-warning fs/binfmt_misc.c --- a/fs/binfmt_misc.c~binfmt_misc-work-around-gcc-49-warning +++ a/fs/binfmt_misc.c @@ -411,12 +411,12 @@ static int parse_command(const char __us { char s[4]; - if (!count) - return 0; if (count > 3) return -EINVAL; if (copy_from_user(s, buffer, count)) return -EFAULT; + if (!count) + return 0; if (s[count-1] == '\n') count--; if (count == 1 && s[0] == '0') _ Patches currently in -mm which might be from arnd@xxxxxxxx are origin.patch linux-next.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html