On Fri, Jun 18, 2021 at 04:07:06PM +0900, Masami Hiramatsu wrote: > @@ -549,7 +548,15 @@ bool unwind_next_frame(struct unwind_state *state) > (void *)orig_ip); > goto err; > } > - > + /* > + * There is a small chance to interrupt at the entry of > + * kretprobe_trampoline where the ORC info doesn't exist. > + * That point is right after the RET to kretprobe_trampoline > + * which was modified return address. So the @addr_p must > + * be right before the regs->sp. > + */ > + state->ip = unwind_recover_kretprobe(state, state->ip, > + (unsigned long *)(state->sp - sizeof(long))); > state->regs = (struct pt_regs *)sp; > state->prev_regs = NULL; > state->full_regs = true; > @@ -562,6 +569,9 @@ bool unwind_next_frame(struct unwind_state *state) > (void *)orig_ip); > goto err; > } > + /* See UNWIND_HINT_TYPE_REGS case comment. */ > + state->ip = unwind_recover_kretprobe(state, state->ip, > + (unsigned long *)(state->sp - sizeof(long))); > > if (state->full_regs) > state->prev_regs = state->regs; Why doesn't the ftrace case have this? That is, why aren't both return trampolines having the same general shape?
