Messages in this thread | | | Date | Mon, 2 May 2022 10:59:21 -0700 | From | Josh Poimboeuf <> | Subject | Re: [PATCH] objtool: Fix STACK_FRAME_NON_STANDARD reloc type |
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On Sat, Apr 30, 2022 at 01:44:00PM +0200, Peter Zijlstra wrote: > > > I also don't see any kprobe/optprobe hooks in unwind.h, so what happens > > > if we hit an optprobe? > > > > Same as for any other generated code, the unwinder will try to fall back > > to frame pointers, and if that doesn't work, the unwind stops. > > > > That commit didn't change anything since it was already not being > > directly executed anyway, but rather used to generate code on the fly. > > > > And before that commit it was being ignored by ORC anyway, thanks to > > STACK_FRAME_NON_STANDARD. Which can now be removed since this code is > > now data and objtool will no longer try to understand it. > > Right; but I suppose I'm wondering if we should fix this. It seems a > rather sub-optimal state of affairs.
Masami recently fixed some kprobes ORC issues but I don't know if this one was fixed.
As to the whether it's worth fixing, I dunno. There are trade offs.
Depends on how common the stack trace is -- I'm guessing not very, since I've never seen a bug report -- and how important it is to get to full ORC coverage. If our goal is full coverage, we'd need a way for generated code to add/remove ORC entries.
-- Josh
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