Messages in this thread | | | Date | Thu, 21 Oct 2021 11:15:12 +0100 | From | Will Deacon <> | Subject | Re: [PATCH v3 6/9] arm64: Recover kretprobe modified return address in stacktrace |
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On Thu, Oct 21, 2021 at 09:55:09AM +0900, Masami Hiramatsu wrote: > Since the kretprobe replaces the function return address with > the kretprobe_trampoline on the stack, stack unwinder shows it > instead of the correct return address. > > This checks whether the next return address is the > __kretprobe_trampoline(), and if so, try to find the correct > return address from the kretprobe instance list. For this purpose > this adds 'kr_cur' loop cursor to memorize the current kretprobe > instance. > > With this fix, now arm64 can enable > CONFIG_ARCH_CORRECT_STACKTRACE_ON_KRETPROBE, and pass the > kprobe self tests. > > Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> > --- > Changes in v2: > - Add comment for kr_cur. > - Make the kretprobe related code depends on CONFIG_KRETPROBES. > - Initialize "kr_cur" directly in start_backtrace() instead > of clearing "frame" data structure by memset(). > --- > arch/arm64/Kconfig | 1 + > arch/arm64/include/asm/stacktrace.h | 4 ++++ > arch/arm64/kernel/stacktrace.c | 7 +++++++ > 3 files changed, 12 insertions(+)
Acked-by: Will Deacon <will@kernel.org>
I'm not sure how you're planning to merge this, so please let me know if you want me to queue any of the arm64 bits.
Will
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