Re: [PATCH 1/4] ftrace: Fix MATCH_END_ONLY filter matching

[Steven Rostedt <rostedt@goodmis.org>]

On Fri, 2009-12-11 at 13:27 +0100, Frederic Weisbecker wrote:
> On Fri, Dec 11, 2009 at 01:20:04PM +0100, Frederic Riss wrote:
> > 2009/12/11 Li Zefan <lizf@cn.fujitsu.com>:
> > > For '*foo' pattern, we should allow any string ending with
> > > 'foo', but ftrace filter incorrectly disallows strings
> > > like bar_foo_foo:
> > [...]
> > >        case MATCH_END_ONLY:
> > > -               ptr = strstr(str, regex);
> > > -               if (ptr && (ptr[len] == 0))
> > > +               slen = strlen(str);
> > > +               if (slen >= len && memcpy(str + slen - len, regex, len))
> > >                        matched = 1;
> > 
> > Shouldn't that be memcmp() == 0? I don't see how memcpy might serve as
> > a compare operator.
> > 
> > Fred.
> 
> 
> Oh you're right, I reviewed it too quickly. Perhaps the star's
> alignment made it possible for only one Frederic to review it
> the right way...
> 

The stars are still fuzzy to me. How does memcpy work here?

-- Steve