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: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
save_all_base_regs
+ /* Setup a frame pointer. */
+ add x29, sp, #S_FP
+
mov x0, sp
bl trampoline_probe_handler
/*
*/
mov lr, x0
+ /* The frame pointer (x29) is restored with other registers. */
restore_all_base_regs
add sp, sp, #PT_REGS_SIZE