Messages in this thread | | | Subject | Re: [PATCH 3/3] Make jprobes a little safer for users | From | Michael Ellerman <> | Date | Tue, 26 Jun 2007 12:06:46 +1000 |
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On Mon, 2007-06-25 at 19:00 -0700, Andrew Morton wrote: > On Tue, 26 Jun 2007 11:48:51 +1000 (EST) Michael Ellerman <michael@ellerman.id.au> wrote: > > > I realise jprobes are a razor-blades-included type of interface, but > > that doesn't mean we can't try and make them safer to use. This guy I > > know once wrote code like this: > > > > struct jprobe jp = { .kp.symbol_name = "foo", .entry = "jprobe_foo" }; > > > > And then his kernel exploded. Oops. > > > > This patch adds an arch hook, arch_deref_entry_point() (I don't like it either) > > which takes the void * in a struct jprobe, and gives back the text address > > that it represents. > > > > We can then use that in register_jprobe() to check that the entry point > > we're passed is actually in the kernel text, rather than just some random > > value. > > > > Signed-off-by: Michael Ellerman <michael@ellerman.id.au> > > --- > > arch/ia64/kernel/kprobes.c | 7 ++++++- > > arch/powerpc/kernel/kprobes.c | 11 ++++++++--- > > kernel/kprobes.c | 9 +++++++++ > > We're missing a declaration of arch_deref_entry_point() in some header file?
Yeah I guess. It's declared weak in kernel/kprobes.c, but there should be a definition somewhere to make sure the three versions don't get out of sync. I'll send a patch.
cheers
-- Michael Ellerman OzLabs, IBM Australia Development Lab
wwweb: http://michael.ellerman.id.au phone: +61 2 6212 1183 (tie line 70 21183)
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