Re: [Qemu-trivial] [Qemu-devel] [PATCH v7] block/vvfat: assert return value of fopen which may fail

[zhanghailiang]

On 2014/8/18 19:42, Michael Tokarev wrote:
> 18.08.2014 12:06, Peter Maydell wrote:
> > On 18 August 2014 09:00, zhanghailiang<address@hidden>  wrote:
> > > From: Li Liu<address@hidden>
> > >
> > > fopen() may return NULL which will cause setbuf() segmentfault
> > >
> > > Signed-off-by: zhanghailiang<address@hidden>
> > > Signed-off-by: Li Liu<address@hidden>
> > > ---
> > >   block/vvfat.c | 1 +
> > >   1 file changed, 1 insertion(+)
> > >
> > > diff --git a/block/vvfat.c b/block/vvfat.c
> > > index 70176b1..62023e1 100644
> > > --- a/block/vvfat.c
> > > +++ b/block/vvfat.c
> > > @@ -1084,6 +1084,7 @@ static int vvfat_open(BlockDriverState *bs, QDict 
> > > *options, int flags,
> > >
> > >   DLOG(if (stderr == NULL) {
> > >       stderr = fopen("vvfat.log", "a");
> > > +    assert(stderr);
> > >       setbuf(stderr, NULL);
> > >   })
> >
> > An assertion is no better than a segfault.
> >
> > Better I think would be to just remove this whole lump of code
> > entirely. Lots of other files do debug printing to stderr without
> > attempting to open a file if stderr happens to be NULL, why
> > should vvfat.c be special?
>
> Indeed.  I've applied a patch which just removes these 6 lines of code
> (and sent it to the list too, for review).
>
> Thanks,
>
> /mjt
>
> .
OK, thanks.:)