Commit fc6d6476 authored by Masami Hiramatsu's avatar Masami Hiramatsu Committed by Steven Rostedt (VMware)
Browse files

arm64: kprobes: Make a frame pointer on __kretprobe_trampoline 



Make a frame pointer (make the x29 register points the
address of pt_regs->regs[29]) on __kretprobe_trampoline.

This frame pointer will be used by the stacktracer when it is
called from the kretprobe handlers. In this case, the stack
tracer will unwind stack to trampoline_probe_handler() and
find the next frame pointer in the stack frame of the
__kretprobe_trampoline().

Signed-off-by: default avatarMasami Hiramatsu <mhiramat@kernel.org>
Acked-by: default avatarWill Deacon <will@kernel.org>
Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
parent f8717410

arch/arm64/kernel/probes/kprobes_trampoline.S

+4 −0
Original line number Diff line number Diff line
@@ -66,6 +66,9 @@ SYM_CODE_START(__kretprobe_trampoline) 


	save_all_base_regs



	/* Setup a frame pointer. */

	add x29, sp, #S_FP



	mov x0, sp

	bl trampoline_probe_handler

	/*
@@ -74,6 +77,7 @@ SYM_CODE_START(__kretprobe_trampoline) 
	 */

	mov lr, x0



	/* The frame pointer (x29) is restored with other registers. */

	restore_all_base_regs



	add sp, sp, #PT_REGS_SIZE