Messages in this thread | ![/](/images/icornerl.gif) | | Date | Fri, 28 Aug 2020 14:31:31 +0100 | From | Mark Rutland <> | Subject | Re: [PATCH v4 04/23] arm64: kprobes: Use generic kretprobe trampoline handler |
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Hi,
On Fri, Aug 28, 2020 at 09:27:22PM +0900, Masami Hiramatsu wrote: > Use the generic kretprobe trampoline handler, and use the > kernel_stack_pointer(regs) for framepointer verification. > > Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> > --- > arch/arm64/kernel/probes/kprobes.c | 78 +----------------------------------- > 1 file changed, 3 insertions(+), 75 deletions(-)
> + return (void *)kretprobe_trampoline_handler(regs, &kretprobe_trampoline, > + (void *)kernel_stack_pointer(regs)); > } > > 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);
This is probably a nomenclature problem, but what exactly is kretprobe_instance::fp used for?
I ask because arm64's frame pointer lives in x29 (and is not necessarily the same as the stack pointer at function boundaries), so the naming is potentially misleading and possibly worth a comment or rename.
Thanks, Mark.
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