On Tue, Jun 02, 2020 at 09:22:30AM +0800, Wangshaobo (bobo) wrote:
so i think this question is related to ORC unwinder, could i ask if you have
strategy or plan to avoid this problem ?
I suspect something like this would fix it (untested):
diff --git a/arch/x86/kernel/stacktrace.c b/arch/x86/kernel/stacktrace.c
index 6ad43fc44556..8cf95ded1410 100644
--- a/arch/x86/kernel/stacktrace.c
+++ b/arch/x86/kernel/stacktrace.c
@@ -50,7 +50,7 @@ int arch_stack_walk_reliable(stack_trace_consume_fn consume_entry,
if (regs) {
/* Success path for user tasks */
if (user_mode(regs))
- return 0;
+ break;
/*
* Kernel mode registers on the stack indicate an@@ -81,10 +81,6 @@ int arch_stack_walk_reliable(stack_trace_consume_fn consume_entry,
if (unwind_error(&state))
return -EINVAL;
- /* Success path for non-user tasks, i.e. kthreads and idle tasks */
- if (!(task->flags & (PF_KTHREAD | PF_IDLE)))
- return -EINVAL;
-
return 0;
}
diff --git a/arch/x86/kernel/unwind_orc.c b/arch/x86/kernel/unwind_orc.c
index 7f969b2d240f..d7396431261a 100644
--- a/arch/x86/kernel/unwind_orc.c
+++ b/arch/x86/kernel/unwind_orc.c
@@ -540,7 +540,7 @@ bool unwind_next_frame(struct unwind_state *state)
state->sp = sp;
state->regs = NULL;
state->prev_regs = NULL;
- state->signal = false;
+ state->signal = ((void *)state->ip == ret_from_fork);
break;
case ORC_TYPE_REGS: