This is a note to let you know that I've just added the patch titled
Revert "x86: Fix __get_wchan() for !STACKTRACE"
to the 5.14-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:
revert-x86-fix-__get_wchan-for-stacktrace.patch
and it can be found in the queue-5.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From b677b2cd3534d4250baaee174a014b4e3f561b34 Mon Sep 17 00:00:00 2001
From: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Date: Thu, 18 Nov 2021 13:15:35 +0100
Subject: Revert "x86: Fix __get_wchan() for !STACKTRACE"
From: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
This reverts commit e1ff40b6194f09c1dd0f45b94fdf30c0374b5823 which is
commit 5d1ceb3969b6b2e47e2df6d17790a7c5a20fcbb4 upstream.
It has been reported to be causing problems, and is being reworked
upstream and has been dropped from the current 5.15.y stable queue until
it gets resolved.
Reported-by: Chris Rankin <rankincj@xxxxxxxxx>
Reported-by: Thorsten Leemhuis <linux@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/ed000478-2a60-0066-c337-a04bffc112b1@xxxxxxxxxxxxx
Cc: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Sasha Levin <sashal@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/kernel/process.c | 17 +++--------------
1 file changed, 3 insertions(+), 14 deletions(-)
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -43,7 +43,6 @@
#include <asm/io_bitmap.h>
#include <asm/proto.h>
#include <asm/frame.h>
-#include <asm/unwind.h>
#include "process.h"
@@ -946,20 +945,10 @@ unsigned long arch_randomize_brk(struct
*/
unsigned long __get_wchan(struct task_struct *p)
{
- struct unwind_state state;
- unsigned long addr = 0;
+ unsigned long entry = 0;
- for (unwind_start(&state, p, NULL, NULL); !unwind_done(&state);
- unwind_next_frame(&state)) {
- addr = unwind_get_return_address(&state);
- if (!addr)
- break;
- if (in_sched_functions(addr))
- continue;
- break;
- }
-
- return addr;
+ stack_trace_save_tsk(p, &entry, 1, 0);
+ return entry;
}
long do_arch_prctl_common(struct task_struct *task, int option,
Patches currently in stable-queue which might be from gregkh@xxxxxxxxxxxxxxxxxxx are
queue-5.14/revert-x86-fix-__get_wchan-for-stacktrace.patch
queue-5.14/revert-x86-fix-get_wchan-to-support-the-orc-unwinder.patch
queue-5.14/revert-sched-add-wrapper-for-get_wchan-to-keep-task-blocked.patch
