On 2025/9/12 上午9:55, Jinyang He wrote:
On 2025-09-11 19:49, Tiezhu Yang wrote:
On 2025/9/10 上午9:11, Jinyang He wrote:
On 2025-09-09 19:31, Tiezhu Yang wrote:
When testing the kernel live patching with "modprobe livepatch-sample",
there is a timeout over 15 seconds from "starting patching transition"
to "patching complete", dmesg shows "unreliable stack" for user tasks
in debug mode. When executing "rmmod livepatch-sample", there exists
the similar issue.
...
for this case, get_stack_info() does not return 0 due to in_task_stack()
is not true, then goto error, state->stack_info.type = STACK_TYPE_UNKNOWN
and state->error = true. In arch_stack_walk_reliable(), the loop will be
break and it returns -EINVAL, thus causing unreliable stack.
The stop position of a complete stack backtrace on LoongArch should be
the top of the task stack or until the address is_entry_func.
Otherwise, it is not a complete stack backtrace, and thus I think it
is an "unreliable stack".
I'm curious about what the ORC info at this PC.
The unwind process has problem, I have found the root cause and am
working to fix the "unreliable stack" issue, it should and can find
the last frame, and then the user_mode() check is not necessary.
Thanks,
Tiezhu
