On Tue, Jul 19, 2022 at 10:19 AM Martin KaFai Lau <kafai@xxxxxx> wrote:
>
> On Tue, Jul 19, 2022 at 12:53:01PM +0300, Dan Carpenter wrote:
> > The return from strcmp() is inverted so the it returns true instead
> > of false and vise versa.
> >
> > Fixes: a1c9d61b19cb ("libbpf: Improve library identification for uprobe binary path resolution")
> > Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> > ---
> > Spotted during review. *cmp() functions should always have a comparison
> > to zero.
> > if (strcmp(a, b) < 0) { <-- means a < b
> > if (strcmp(a, b) >= 0) { <-- means a >= b
> > if (strcmp(a, b) != 0) { <-- means a != b
> > etc.
> >
> > tools/lib/bpf/libbpf_internal.h | 6 +++---
> > 1 file changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h
> > index 9cd7829cbe41..008485296a29 100644
> > --- a/tools/lib/bpf/libbpf_internal.h
> > +++ b/tools/lib/bpf/libbpf_internal.h
> > @@ -108,9 +108,9 @@ static inline bool str_has_sfx(const char *str, const char *sfx)
> > size_t str_len = strlen(str);
> > size_t sfx_len = strlen(sfx);
> >
> > - if (sfx_len <= str_len)
> > - return strcmp(str + str_len - sfx_len, sfx);
> > - return false;
> > + if (sfx_len > str_len)
> > + return false;
> > + return strcmp(str + str_len - sfx_len, sfx) == 0;
> Please tag the subject with "bpf" next time.
>
> Acked-by: Martin KaFai Lau <kafai@xxxxxx>
Alan,
If it was so broken how did it work earlier?
Do we have a test for this?
