Messages in this thread | | | Date | Wed, 7 Sep 2022 16:28:28 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH 1/2] x86/kprobes: Fix kprobes instruction boudary check with CONFIG_RETHUNK |
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On Wed, Sep 07, 2022 at 10:49:13PM +0900, Masami Hiramatsu wrote: > On Wed, 7 Sep 2022 14:56:52 +0200 > Peter Zijlstra <peterz@infradead.org> wrote: > > > On Wed, Sep 07, 2022 at 09:55:21AM +0900, Masami Hiramatsu (Google) wrote: > > > > > if (!kallsyms_lookup_size_offset(paddr, NULL, &offset)) > > > return 0; > > > > > > > One more thing: > > > > https://lkml.kernel.org/r/20220902130951.853460809@infradead.org > > > > can result in negative offsets. The expression: > > > > 'paddr - offset' > > > > will still get you to +0, but I might not have fully considered things > > when I wrote that patch. > > Hmm, isn't 'offset' unsigned? If 'paddr - offset' is still available > to find the function entry address, it is OK to me.
Yeah, but the magic of 2s complement means it doesn't matter ;-)
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