On Thu, Feb 28, 2019 at 09:35:50AM +0100, Richard Weinberger wrote:
> Am Donnerstag, 28. Februar 2019, 06:35:51 CET schrieb Dan Carpenter:
> > This condition needs to be fipped around because "err" is uninitialized
> > when "force" is set. The Smatch static analysis tool complains and
> > UBsan will also complain at runtime.
> >
> > Fixes: 663586c0a892 ("ubi: Expose the bitrot interface")
> > Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Reviewed-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
Tested-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
This fixes a -Wsometimes-uninitialized warning from Clang:
drivers/mtd/ubi/wl.c:1514:6: warning: variable 'err' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
if (!force) {
^~~~~~
drivers/mtd/ubi/wl.c:1520:6: note: uninitialized use occurs here
if (err == UBI_IO_BITFLIPS || force) {
^~~
drivers/mtd/ubi/wl.c:1514:2: note: remove the 'if' if its condition is always true
if (!force) {
^~~~~~~~~~~~
drivers/mtd/ubi/wl.c:1478:9: note: initialize the variable 'err' to silence this warning
int err;
^
= 0
1 warning generated.
> > ---
> > drivers/mtd/ubi/wl.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c
> > index 40f838d54b0f..2709dc02fc24 100644
> > --- a/drivers/mtd/ubi/wl.c
> > +++ b/drivers/mtd/ubi/wl.c
> > @@ -1517,7 +1517,7 @@ int ubi_bitflip_check(struct ubi_device *ubi, int pnum, int force)
> > mutex_unlock(&ubi->buf_mutex);
> > }
> >
> > - if (err == UBI_IO_BITFLIPS || force) {
> > + if (force || err == UBI_IO_BITFLIPS) {
> > /*
> > * Okay, bit flip happened, let's figure out what we can do.
> > */
> >
>
> Good catch, Dan!
> I thought gcc is supposed to find such issues too. :-/
This isn't the first time GCC hasn't caught something...
https://lore.kernel.org/lkml/20190221222123.GC6474@magnolia/
>
> Thanks,
> //richard
>
>
Thanks,
Nathan
