Messages in this thread | | | Date | Wed, 13 Oct 2021 09:14:45 +0100 | From | Will Deacon <> | Subject | Re: [PATCH 3/8] arm64: kprobes: Record frame pointer with kretprobe instance |
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On Fri, Oct 08, 2021 at 09:28:39PM +0900, Masami Hiramatsu wrote: > Record the frame pointer instead of stack address with kretprobe > instance as the identifier on the instance list. > Since arm64 always enable CONFIG_FRAME_POINTER, we can use the > actual frame pointer (x29). > > Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> > --- > arch/arm64/kernel/probes/kprobes.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/arm64/kernel/probes/kprobes.c b/arch/arm64/kernel/probes/kprobes.c > index e7ad6da980e8..d9dfa82c1f18 100644 > --- a/arch/arm64/kernel/probes/kprobes.c > +++ b/arch/arm64/kernel/probes/kprobes.c > @@ -401,14 +401,14 @@ int __init arch_populate_kprobe_blacklist(void) > > void __kprobes __used *trampoline_probe_handler(struct pt_regs *regs) > { > - return (void *)kretprobe_trampoline_handler(regs, (void *)kernel_stack_pointer(regs)); > + return (void *)kretprobe_trampoline_handler(regs, (void *)regs->regs[29]); > } > > void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, > struct pt_regs *regs) > { > ri->ret_addr = (kprobe_opcode_t *)regs->regs[30]; > - ri->fp = (void *)kernel_stack_pointer(regs); > + ri->fp = (void *)regs->regs[29]; > > /* replace return addr (x30) with trampoline */ > regs->regs[30] = (long)&__kretprobe_trampoline;
Acked-by: Will Deacon <will@kernel.org>
Will
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