From: Masami Hiramatsu Date: Thu, 21 Oct 2021 00:54:51 +0000 (+0900) Subject: arm64: kprobes: Record frame pointer with kretprobe instance X-Git-Tag: io_uring-5.16-2021-11-09~9^2~37 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=f8717410621571b182d3f2c45ffc52796c418787;p=linux-block.git arm64: kprobes: Record frame pointer with kretprobe instance 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). This will allow the stacktrace code to find the original return address from the FP alone. Signed-off-by: Masami Hiramatsu Acked-by: Will Deacon Acked-by: Mark Rutland Signed-off-by: Steven Rostedt (VMware) --- 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;