Re: [PATCH v2] cpupower:Fix resource leaks in sysfs_get_enabled()

[Hao Zeng <zenghao@kylinos.cn>]

Hi Shuah , Thanks very much for your review!
I tried to understand what you said as best I could and provided V3.
I look forward to your review again, it will help me a lot!

Best regards
-- Hao

On Fri, 2023-04-14 at 10:41 -0600, Shuah Khan wrote:
> On 4/13/23 21:08, Hao Zeng wrote:
> > When the read return value is equal to 1, a file handle leak will
> > occur
> > 
> 
> Would like a bit more information on how the error paths are
> redone, since memory leak isn't the only one that is fixed.
> 
> > Signed-off-by: Hao Zeng <zenghao@kylinos.cn>
> > Suggested-by: Shuah Khan <skhan@linuxfoundation.org>
> > ---
> >   tools/power/cpupower/lib/powercap.c | 19 ++++++++++---------
> >   1 file changed, 10 insertions(+), 9 deletions(-)
> > 
> > diff --git a/tools/power/cpupower/lib/powercap.c
> > b/tools/power/cpupower/lib/powercap.c
> > index 0ce29ee4c2e4..02ec5b0bff6b 100644
> > --- a/tools/power/cpupower/lib/powercap.c
> > +++ b/tools/power/cpupower/lib/powercap.c
> > @@ -40,7 +40,7 @@ static int sysfs_get_enabled(char *path, int
> > *mode)
> >   {
> >         int fd;
> >         char yes_no;
> > -
> > +       int ret = 0;
> >         *mode = 0;
> >   
> >         fd = open(path, O_RDONLY);
> > @@ -48,17 +48,18 @@ static int sysfs_get_enabled(char *path, int
> > *mode)
> >                 return -1;
> >   
> >         if (read(fd, &yes_no, 1) != 1) {
> > -               close(fd);
> > -               return -1;
> > +               ret = -1;
> > +               goto err;
> >         }
> >   
> > -       if (yes_no == '1') {
> > -               *mode = 1;
> > -               return 0;
> > -       } else if (yes_no == '0') {
> > -               return 0;
> > +       if (yes_no != '1' || yes_no != '0') {
> > +               ret = -1;
> > +               goto err;
> >         }
> > -       return -1;
> > +       *mode = yes_no - '0';
> 
> I am not seeing much value in changing the above paths.
> Leave them unchanged.
> 
> > +err:
> > +       close(fd);
> > +       return ret;
> >   }
> >   
> >   int powercap_get_enabled(int *mode)
> 
> thanks,
> -- Shuah