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

From: Steven Rostedt
Date: Fri Dec 11 2009 - 10:10:40 EST


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@xxxxxxxxxxxxxx>:
> > > 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


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