Messages in this thread | | | Date | Fri, 10 Feb 2023 13:30:53 -0800 | From | Josh Poimboeuf <> | Subject | Re: [PATCH] x86/unwind/orc: Fix unwind ip when kprobes hits push/pop |
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On Thu, Dec 01, 2022 at 04:53:11PM +0800, Chen Zhongjin wrote: > When unwind stack at asm_exc_int3, the orc type is UNWIND_HINT_TYPE_REGS > and the unwinder will use pt_regs->ip to find next orc, which point to > the probed insn + INT3_INSN_SIZE. > > If the probed insn is push/pop, it will point to the next insn which has > different orc state. Before the probed insn has been really excuted in > single step, using next insn ip to find orc will get a wrong unwinding > result. > > So, when there is kprobe running and the previous op code is int3, > state->signal should be false so that ip - 1 will be used to find next > orc, until the probed push/pop has been single steped and kprobe set > kprobe_status as KPROBE_HIT_SSDONE. > > Fixes: ee9f8fce9964 ("x86/unwind: Add the ORC unwinder") > Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
Hi Chen,
Thanks for reporting this, and sorry for the delay. I would rather fix this in a more general way, by specifying 'signal' (or lack thereof) in the ORC data. I will work up a patch.
-- Josh
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