Re: [PATCH] bpftool: optimize if statement code

[Martin KaFai Lau]

On 10/15/24 5:11 AM, Quentin Monnet wrote:
> 2024-10-15 19:09 UTC+0800 ~ Liu Jing <liujing@xxxxxxxxxxxxxxxxxxxx>
> > Since both conditions are used to check whether len is valid, we can combine 
> > the two conditions into a single if statement
> > Signed-off-by: Liu Jing <liujing@xxxxxxxxxxxxxxxxxxxx>
> > ---
> >   tools/bpf/bpftool/feature.c | 5 ++---
> >   1 file changed, 2 insertions(+), 3 deletions(-)
> >
> > diff --git a/tools/bpf/bpftool/feature.c b/tools/bpf/bpftool/feature.c
> > index 4dbc4fcdf473..0121e0fd6949 100644
> > --- a/tools/bpf/bpftool/feature.c
> > +++ b/tools/bpf/bpftool/feature.c
> > @@ -158,10 +158,9 @@ static int get_vendor_id(int ifindex)
> >       len = read(fd, buf, sizeof(buf));
> >       close(fd);
> > -    if (len < 0)
> > -        return -1;
> > -    if (len >= (ssize_t)sizeof(buf))
> > +    if ((len < 0) || (len >= (ssize_t)sizeof(buf)))
> >           return -1;
> > +
> >       buf[len] = '\0';
> >       return strtol(buf, NULL, 0);
>
>
> Thanks. I'm not strictly opposed to the change, but it doesn't bring much value 
> in my opinion. I don't think this will "optimize" the statement beyond what the 
> compiler does already.

+1

The current code is good as is.

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