This is a note to let you know that I've just added the patch titled
LoongArch: Check unwind_error() in arch_stack_walk()
to the 6.2-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
loongarch-check-unwind_error-in-arch_stack_walk.patch
and it can be found in the queue-6.2 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 370a3b8f58743eceb97c5256538d6048c26d2d03 Mon Sep 17 00:00:00 2001
From: Tiezhu Yang <yangtiezhu@xxxxxxxxxxx>
Date: Wed, 19 Apr 2023 12:07:27 +0800
Subject: LoongArch: Check unwind_error() in arch_stack_walk()
From: Tiezhu Yang <yangtiezhu@xxxxxxxxxxx>
commit 370a3b8f58743eceb97c5256538d6048c26d2d03 upstream.
We can see the following messages with CONFIG_PROVE_LOCKING=y on
LoongArch:
BUG: MAX_STACK_TRACE_ENTRIES too low!
turning off the locking correctness validator.
This is because stack_trace_save() returns a big value after call
arch_stack_walk(), here is the call trace:
save_trace()
stack_trace_save()
arch_stack_walk()
stack_trace_consume_entry()
arch_stack_walk() should return immediately if unwind_next_frame()
failed, no need to do the useless loops to increase the value of c->len
in stack_trace_consume_entry(), then we can fix the above problem.
Cc: stable@xxxxxxxxxxxxxxx
Reported-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Link: https://lore.kernel.org/all/8a44ad71-68d2-4926-892f-72bfc7a67e2a@xxxxxxxxxxxx/
Signed-off-by: Tiezhu Yang <yangtiezhu@xxxxxxxxxxx>
Signed-off-by: Huacai Chen <chenhuacai@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/loongarch/kernel/stacktrace.c | 2 +-
arch/loongarch/kernel/unwind.c | 1 +
arch/loongarch/kernel/unwind_prologue.c | 4 +++-
3 files changed, 5 insertions(+), 2 deletions(-)
--- a/arch/loongarch/kernel/stacktrace.c
+++ b/arch/loongarch/kernel/stacktrace.c
@@ -30,7 +30,7 @@ void arch_stack_walk(stack_trace_consume
regs->regs[1] = 0;
for (unwind_start(&state, task, regs);
- !unwind_done(&state); unwind_next_frame(&state)) {
+ !unwind_done(&state) && !unwind_error(&state); unwind_next_frame(&state)) {
addr = unwind_get_return_address(&state);
if (!addr || !consume_entry(cookie, addr))
break;
--- a/arch/loongarch/kernel/unwind.c
+++ b/arch/loongarch/kernel/unwind.c
@@ -28,5 +28,6 @@ bool default_next_frame(struct unwind_st
} while (!get_stack_info(state->sp, state->task, info));
+ state->error = true;
return false;
}
--- a/arch/loongarch/kernel/unwind_prologue.c
+++ b/arch/loongarch/kernel/unwind_prologue.c
@@ -211,7 +211,7 @@ static bool next_frame(struct unwind_sta
pc = regs->csr_era;
if (user_mode(regs) || !__kernel_text_address(pc))
- return false;
+ goto out;
state->first = true;
state->pc = pc;
@@ -226,6 +226,8 @@ static bool next_frame(struct unwind_sta
} while (!get_stack_info(state->sp, state->task, info));
+out:
+ state->error = true;
return false;
}
Patches currently in stable-queue which might be from yangtiezhu@xxxxxxxxxxx are
queue-6.2/loongarch-check-unwind_error-in-arch_stack_walk.patch
queue-6.2/loongarch-fix-build-error-if-config_suspend-is-not-s.patch
