Re: [PATCH 3/3] tracing/filters: disallow newline as delimeter

From: Ingo Molnar
Date: Wed Apr 22 2009 - 04:10:04 EST



* Tom Zanussi <tzanussi@xxxxxxxxx> wrote:

> On Tue, 2009-04-21 at 12:16 +0200, Ingo Molnar wrote:
> > * Li Zefan <lizf@xxxxxxxxxxxxxx> wrote:
> >
> > > Ingo Molnar wrote:
> > > > * Li Zefan <lizf@xxxxxxxxxxxxxx> wrote:
> > > >
> > > >> Ingo Molnar wrote:
> > > >>> * Li Zefan <lizf@xxxxxxxxxxxxxx> wrote:
> > > >>>
> > > >>>> I guess because user input is often ended with '\n' (like "echo
> > > >>>> xxx"), thus '\n' is used as a delimeter besides ' ', but we can
> > > >>>> just strip tailing spaces.
> > > >>> Hm, how about:
> > > >>>
> > > >>> ( echo 'x'
> > > >>> echo '|| y' ) > filter
> > > >>>
> > > >>> type of scripts? Shouldnt the parser be permissive in general?
> > > >>>
> > > >> This patch doesn't forbid this usage: ;)
> > > >>
> > > >> ( echo 'parent_comm == a'
> > > >> echo '|| parent_comm == b' ) > filter
> > > >>
> > > >> This patch does forbid this usage:
> > > >>
> > > >> ( echo 'parent_comm'
> > > >> echo '=='
> > > >> echo 'a' ) > filter
> > > >
> > > > Same argument though, no?
> > > >
> > >
> > > Then I have no strong opinion on this. I'm fine to drop this patch.
> >
> > I've applied the other two - no strong opinion either about this
> > patch. Tom, what do you think? (there's also some new parser in the
> > works i suspect)
>
> I think it works ok as it is, so dropping this patch would be fine
> with me.
>
> I am working on a new parser; I'd hoped to have it finished by
> now, but I seem to be continually distracted lately. :-( At this
> point I have a parser that basically works; the main thing it
> still needs and what I'm working on now is a way to allow it to be
> easily extended to support special-case handling for special types
> e.g. if a predicate field refers to something that's a dev_t, the
> user should be able to specify 'device == /dev/sda' or 'device ==
> sda' or 'device == (8,1)' or 'device == 8:1', so it should be
> relatively easy to add that kind of support to the parser when
> there's a need for it.
>
> Once that's done, I'll hook it all up and post it as soon as I
> can, at the end of the week hopefully...

Nice! :-)

If your current lineup works you might want to post that straight
away even without the type extensions, if you think there's value in
testing/reviewing those bits independently. It generally works
better to have gradual patches. (we can find bugs sooner, review is
easier, etc.)

Ingo
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/