Re:[PATCH] qemu: Fix error returned value in qemuGetProcessInfo when fscanf execute failed

[wang.yi59 at zte.com.cn]

Hi Michal,

Thanks for your reply.

> On 7/15/21 8:18 AM, Yi Wang wrote:
> > From: Long YunJian <long.yunjian at zte.com.cn>
> >
> > If fscanf execute failed, qemuGetProcessInfo shuld return -1,
> > but it return 0 at the end. Zero means success for the caller,
> > so we shuld return -1 in the case of failure.
> >
...
> >                 /* cutime -> endcode */
> > @@ -1455,6 +1457,8 @@ qemuGetProcessInfo(unsigned long long *cpuTime, int *lastCpu, long *vm_rss,
> >                 "%*u %*u %*u %*u %*u %*u %*u %*u %*u %*u %*d %d",
> >                 &usertime, &systime, &rss, &cpu) != 4) {
> >          VIR_WARN("cannot parse process status data");
> > +        VIR_FORCE_FCLOSE(pidinfo);
> > +        return -1;
>
> There's another VIR_FORCE_FCLOSE() at the end of the function. It should
> be removed.

VIR_FORCE_FCLOSE() at the end of the function means in the
situation of success, but VIR_FORCE_FCLOSE before return -1 is
failure situation. if removed, it will result in not close pidinfo.

>
> But is there an actual error you're seeing? Has /proc/NNN/stat format
> changed? Also, please use git send-email if possible - it allows
> reviewers to use git am (which doesn't work with multipart e-mails).

I haven't meet fscanf return error,  but in some abnormal situation,
such as interrupted by a signal or out of memory, it may return failure.

Actually I used git send-email to send this patch, if there's something
wrong, please let me know and I will forward that to our IT department :)

>
> Michal