Commit f8717410 authored by Masami Hiramatsu's avatar Masami Hiramatsu Committed by Steven Rostedt (VMware)
Browse files

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: default avatarMasami Hiramatsu <mhiramat@kernel.org>
Acked-by: default avatarWill Deacon <will@kernel.org>
Acked-by: default avatarMark Rutland <mark.rutland@arm.com>
Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
parent 811b93ff

arch/arm64/kernel/probes/kprobes.c

+2 −2
Original line number Diff line number Diff line
@@ -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;