On Fri, Mar 27, 2020 at 10:10 AM Nathan Chancellor
<natechancellor@xxxxxxxxx> wrote:
>
> Clang warns:
>
> fs/notify/fanotify/fanotify.c:28:23: warning: self-comparison always
> evaluates to true [-Wtautological-compare]
> return fsid1->val[0] == fsid1->val[0] && fsid2->val[1] == fsid2->val[1];
> ^
> fs/notify/fanotify/fanotify.c:28:57: warning: self-comparison always
> evaluates to true [-Wtautological-compare]
> return fsid1->val[0] == fsid1->val[0] && fsid2->val[1] == fsid2->val[1];
> ^
> 2 warnings generated.
>
> The intention was clearly to compare val[0] and val[1] in the two
> different fsid structs. Fix it otherwise this function always returns
> true.
>
> Fixes: afc894c784c8 ("fanotify: Store fanotify handles differently")
> Link: https://github.com/ClangBuiltLinux/linux/issues/952
> Signed-off-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
Thanks for the patch. Subtle bugs that are off by one character have
always been hard for me to spot!
Reviewed-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
> ---
> fs/notify/fanotify/fanotify.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c
> index 7a889da1ee12..cb54ecdb3fb9 100644
> --- a/fs/notify/fanotify/fanotify.c
> +++ b/fs/notify/fanotify/fanotify.c
> @@ -25,7 +25,7 @@ static bool fanotify_path_equal(struct path *p1, struct path *p2)
> static inline bool fanotify_fsid_equal(__kernel_fsid_t *fsid1,
> __kernel_fsid_t *fsid2)
> {
> - return fsid1->val[0] == fsid1->val[0] && fsid2->val[1] == fsid2->val[1];
> + return fsid1->val[0] == fsid2->val[0] && fsid1->val[1] == fsid2->val[1];
> }
>
> static bool fanotify_fh_equal(struct fanotify_fh *fh1,
> --
--
Thanks,
~Nick Desaulniers
