This is a note to let you know that I've just added the patch titled
Revert "sched: Add wrapper for get_wchan() to keep task blocked"
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-sched-add-wrapper-for-get_wchan-to-keep-task-blocked.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 d94be04eac8c75c46ce4ee934f9f0cb466c136bc Mon Sep 17 00:00:00 2001
From: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Date: Thu, 18 Nov 2021 13:15:48 +0100
Subject: Revert "sched: Add wrapper for get_wchan() to keep task blocked"
From: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
This reverts commit e9ede14c116f1a6246eee89d320d60a90a86b5d5 which is
commit 42a20f86dc19f9282d974df0ba4d226c865ab9dd 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: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
Cc: Russell King (Oracle) <rmk+kernel@xxxxxxxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Sasha Levin <sashal@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/alpha/include/asm/processor.h | 2 +-
arch/alpha/kernel/process.c | 5 +++--
arch/arc/include/asm/processor.h | 2 +-
arch/arc/kernel/stacktrace.c | 4 ++--
arch/arm/include/asm/processor.h | 2 +-
arch/arm/kernel/process.c | 4 +++-
arch/arm64/include/asm/processor.h | 2 +-
arch/arm64/kernel/process.c | 4 +++-
arch/csky/include/asm/processor.h | 2 +-
arch/csky/kernel/stacktrace.c | 5 +++--
arch/h8300/include/asm/processor.h | 2 +-
arch/h8300/kernel/process.c | 5 ++++-
arch/hexagon/include/asm/processor.h | 2 +-
arch/hexagon/kernel/process.c | 4 +++-
arch/ia64/include/asm/processor.h | 2 +-
arch/ia64/kernel/process.c | 5 ++++-
arch/m68k/include/asm/processor.h | 2 +-
arch/m68k/kernel/process.c | 4 +++-
arch/microblaze/include/asm/processor.h | 2 +-
arch/microblaze/kernel/process.c | 2 +-
arch/mips/include/asm/processor.h | 2 +-
arch/mips/kernel/process.c | 8 +++++---
arch/nds32/include/asm/processor.h | 2 +-
arch/nds32/kernel/process.c | 7 ++++++-
arch/nios2/include/asm/processor.h | 2 +-
arch/nios2/kernel/process.c | 5 ++++-
arch/openrisc/include/asm/processor.h | 2 +-
arch/openrisc/kernel/process.c | 2 +-
arch/parisc/include/asm/processor.h | 2 +-
arch/parisc/kernel/process.c | 5 ++++-
arch/powerpc/include/asm/processor.h | 2 +-
arch/powerpc/kernel/process.c | 9 ++++++---
arch/riscv/include/asm/processor.h | 2 +-
arch/riscv/kernel/stacktrace.c | 12 +++++++-----
arch/s390/include/asm/processor.h | 2 +-
arch/s390/kernel/process.c | 4 ++--
arch/sh/include/asm/processor_32.h | 2 +-
arch/sh/kernel/process_32.c | 5 ++++-
arch/sparc/include/asm/processor_32.h | 2 +-
arch/sparc/include/asm/processor_64.h | 2 +-
arch/sparc/kernel/process_32.c | 5 ++++-
arch/sparc/kernel/process_64.c | 5 ++++-
arch/um/include/asm/processor-generic.h | 2 +-
arch/um/kernel/process.c | 5 ++++-
arch/x86/include/asm/processor.h | 2 +-
arch/x86/kernel/process.c | 5 ++++-
arch/xtensa/include/asm/processor.h | 2 +-
arch/xtensa/kernel/process.c | 5 ++++-
include/linux/sched.h | 1 -
kernel/sched/core.c | 19 -------------------
50 files changed, 112 insertions(+), 80 deletions(-)
--- a/arch/alpha/include/asm/processor.h
+++ b/arch/alpha/include/asm/processor.h
@@ -42,7 +42,7 @@ extern void start_thread(struct pt_regs
struct task_struct;
extern void release_thread(struct task_struct *);
-unsigned long __get_wchan(struct task_struct *p);
+unsigned long get_wchan(struct task_struct *p);
#define KSTK_EIP(tsk) (task_pt_regs(tsk)->pc)
--- a/arch/alpha/kernel/process.c
+++ b/arch/alpha/kernel/process.c
@@ -376,11 +376,12 @@ thread_saved_pc(struct task_struct *t)
}
unsigned long
-__get_wchan(struct task_struct *p)
+get_wchan(struct task_struct *p)
{
unsigned long schedule_frame;
unsigned long pc;
-
+ if (!p || p == current || task_is_running(p))
+ return 0;
/*
* This one depends on the frame size of schedule(). Do a
* "disass schedule" in gdb to find the frame size. Also, the
--- a/arch/arc/include/asm/processor.h
+++ b/arch/arc/include/asm/processor.h
@@ -70,7 +70,7 @@ struct task_struct;
extern void start_thread(struct pt_regs * regs, unsigned long pc,
unsigned long usp);
-extern unsigned int __get_wchan(struct task_struct *p);
+extern unsigned int get_wchan(struct task_struct *p);
#endif /* !__ASSEMBLY__ */
--- a/arch/arc/kernel/stacktrace.c
+++ b/arch/arc/kernel/stacktrace.c
@@ -15,7 +15,7 @@
* = specifics of data structs where trace is saved(CONFIG_STACKTRACE etc)
*
* vineetg: March 2009
- * -Implemented correct versions of thread_saved_pc() and __get_wchan()
+ * -Implemented correct versions of thread_saved_pc() and get_wchan()
*
* rajeshwarr: 2008
* -Initial implementation
@@ -248,7 +248,7 @@ void show_stack(struct task_struct *tsk,
* Of course just returning schedule( ) would be pointless so unwind until
* the function is not in schedular code
*/
-unsigned int __get_wchan(struct task_struct *tsk)
+unsigned int get_wchan(struct task_struct *tsk)
{
return arc_unwind_core(tsk, NULL, __get_first_nonsched, NULL);
}
--- a/arch/arm/include/asm/processor.h
+++ b/arch/arm/include/asm/processor.h
@@ -84,7 +84,7 @@ struct task_struct;
/* Free all resources held by a thread. */
extern void release_thread(struct task_struct *);
-unsigned long __get_wchan(struct task_struct *p);
+unsigned long get_wchan(struct task_struct *p);
#define task_pt_regs(p) \
((struct pt_regs *)(THREAD_START_SP + task_stack_page(p)) - 1)
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -283,11 +283,13 @@ int copy_thread(unsigned long clone_flag
return 0;
}
-unsigned long __get_wchan(struct task_struct *p)
+unsigned long get_wchan(struct task_struct *p)
{
struct stackframe frame;
unsigned long stack_page;
int count = 0;
+ if (!p || p == current || task_is_running(p))
+ return 0;
frame.fp = thread_saved_fp(p);
frame.sp = thread_saved_sp(p);
--- a/arch/arm64/include/asm/processor.h
+++ b/arch/arm64/include/asm/processor.h
@@ -251,7 +251,7 @@ struct task_struct;
/* Free all resources held by a thread. */
extern void release_thread(struct task_struct *);
-unsigned long __get_wchan(struct task_struct *p);
+unsigned long get_wchan(struct task_struct *p);
void set_task_sctlr_el1(u64 sctlr);
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -544,11 +544,13 @@ __notrace_funcgraph struct task_struct *
return last;
}
-unsigned long __get_wchan(struct task_struct *p)
+unsigned long get_wchan(struct task_struct *p)
{
struct stackframe frame;
unsigned long stack_page, ret = 0;
int count = 0;
+ if (!p || p == current || task_is_running(p))
+ return 0;
stack_page = (unsigned long)try_get_task_stack(p);
if (!stack_page)
--- a/arch/csky/include/asm/processor.h
+++ b/arch/csky/include/asm/processor.h
@@ -81,7 +81,7 @@ static inline void release_thread(struct
extern int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
-unsigned long __get_wchan(struct task_struct *p);
+unsigned long get_wchan(struct task_struct *p);
#define KSTK_EIP(tsk) (task_pt_regs(tsk)->pc)
#define KSTK_ESP(tsk) (task_pt_regs(tsk)->usp)
--- a/arch/csky/kernel/stacktrace.c
+++ b/arch/csky/kernel/stacktrace.c
@@ -111,11 +111,12 @@ static bool save_wchan(unsigned long pc,
return false;
}
-unsigned long __get_wchan(struct task_struct *task)
+unsigned long get_wchan(struct task_struct *task)
{
unsigned long pc = 0;
- walk_stackframe(task, NULL, save_wchan, &pc);
+ if (likely(task && task != current && !task_is_running(task)))
+ walk_stackframe(task, NULL, save_wchan, &pc);
return pc;
}
--- a/arch/h8300/include/asm/processor.h
+++ b/arch/h8300/include/asm/processor.h
@@ -105,7 +105,7 @@ static inline void release_thread(struct
{
}
-unsigned long __get_wchan(struct task_struct *p);
+unsigned long get_wchan(struct task_struct *p);
#define KSTK_EIP(tsk) \
({ \
--- a/arch/h8300/kernel/process.c
+++ b/arch/h8300/kernel/process.c
@@ -128,12 +128,15 @@ int copy_thread(unsigned long clone_flag
return 0;
}
-unsigned long __get_wchan(struct task_struct *p)
+unsigned long get_wchan(struct task_struct *p)
{
unsigned long fp, pc;
unsigned long stack_page;
int count = 0;
+ if (!p || p == current || task_is_running(p))
+ return 0;
+
stack_page = (unsigned long)p;
fp = ((struct pt_regs *)p->thread.ksp)->er6;
do {
--- a/arch/hexagon/include/asm/processor.h
+++ b/arch/hexagon/include/asm/processor.h
@@ -64,7 +64,7 @@ struct thread_struct {
extern void release_thread(struct task_struct *dead_task);
/* Get wait channel for task P. */
-extern unsigned long __get_wchan(struct task_struct *p);
+extern unsigned long get_wchan(struct task_struct *p);
/* The following stuff is pretty HEXAGON specific. */
--- a/arch/hexagon/kernel/process.c
+++ b/arch/hexagon/kernel/process.c
@@ -130,11 +130,13 @@ void flush_thread(void)
* is an identification of the point at which the scheduler
* was invoked by a blocked thread.
*/
-unsigned long __get_wchan(struct task_struct *p)
+unsigned long get_wchan(struct task_struct *p)
{
unsigned long fp, pc;
unsigned long stack_page;
int count = 0;
+ if (!p || p == current || task_is_running(p))
+ return 0;
stack_page = (unsigned long)task_stack_page(p);
fp = ((struct hexagon_switch_stack *)p->thread.switch_sp)->fp;
--- a/arch/ia64/include/asm/processor.h
+++ b/arch/ia64/include/asm/processor.h
@@ -330,7 +330,7 @@ struct task_struct;
#define release_thread(dead_task)
/* Get wait channel for task P. */
-extern unsigned long __get_wchan (struct task_struct *p);
+extern unsigned long get_wchan (struct task_struct *p);
/* Return instruction pointer of blocked task TSK. */
#define KSTK_EIP(tsk) \
--- a/arch/ia64/kernel/process.c
+++ b/arch/ia64/kernel/process.c
@@ -523,12 +523,15 @@ exit_thread (struct task_struct *tsk)
}
unsigned long
-__get_wchan (struct task_struct *p)
+get_wchan (struct task_struct *p)
{
struct unw_frame_info info;
unsigned long ip;
int count = 0;
+ if (!p || p == current || task_is_running(p))
+ return 0;
+
/*
* Note: p may not be a blocked task (it could be current or
* another process running on some other CPU. Rather than
--- a/arch/m68k/include/asm/processor.h
+++ b/arch/m68k/include/asm/processor.h
@@ -125,7 +125,7 @@ static inline void release_thread(struct
{
}
-unsigned long __get_wchan(struct task_struct *p);
+unsigned long get_wchan(struct task_struct *p);
#define KSTK_EIP(tsk) \
({ \
--- a/arch/m68k/kernel/process.c
+++ b/arch/m68k/kernel/process.c
@@ -263,11 +263,13 @@ int dump_fpu (struct pt_regs *regs, stru
}
EXPORT_SYMBOL(dump_fpu);
-unsigned long __get_wchan(struct task_struct *p)
+unsigned long get_wchan(struct task_struct *p)
{
unsigned long fp, pc;
unsigned long stack_page;
int count = 0;
+ if (!p || p == current || task_is_running(p))
+ return 0;
stack_page = (unsigned long)task_stack_page(p);
fp = ((struct switch_stack *)p->thread.ksp)->a6;
--- a/arch/microblaze/include/asm/processor.h
+++ b/arch/microblaze/include/asm/processor.h
@@ -68,7 +68,7 @@ static inline void release_thread(struct
{
}
-unsigned long __get_wchan(struct task_struct *p);
+unsigned long get_wchan(struct task_struct *p);
/* The size allocated for kernel stacks. This _must_ be a power of two! */
# define KERNEL_STACK_SIZE 0x2000
--- a/arch/microblaze/kernel/process.c
+++ b/arch/microblaze/kernel/process.c
@@ -112,7 +112,7 @@ int copy_thread(unsigned long clone_flag
return 0;
}
-unsigned long __get_wchan(struct task_struct *p)
+unsigned long get_wchan(struct task_struct *p)
{
/* TBD (used by procfs) */
return 0;
--- a/arch/mips/include/asm/processor.h
+++ b/arch/mips/include/asm/processor.h
@@ -369,7 +369,7 @@ static inline void flush_thread(void)
{
}
-unsigned long __get_wchan(struct task_struct *p);
+unsigned long get_wchan(struct task_struct *p);
#define __KSTK_TOS(tsk) ((unsigned long)task_stack_page(tsk) + \
THREAD_SIZE - 32 - sizeof(struct pt_regs))
--- a/arch/mips/kernel/process.c
+++ b/arch/mips/kernel/process.c
@@ -511,7 +511,7 @@ static int __init frame_info_init(void)
/*
* Without schedule() frame info, result given by
- * thread_saved_pc() and __get_wchan() are not reliable.
+ * thread_saved_pc() and get_wchan() are not reliable.
*/
if (schedule_mfi.pc_offset < 0)
printk("Can't analyze schedule() prologue at %p\n", schedule);
@@ -652,9 +652,9 @@ unsigned long unwind_stack(struct task_s
#endif
/*
- * __get_wchan - a maintenance nightmare^W^Wpain in the ass ...
+ * get_wchan - a maintenance nightmare^W^Wpain in the ass ...
*/
-unsigned long __get_wchan(struct task_struct *task)
+unsigned long get_wchan(struct task_struct *task)
{
unsigned long pc = 0;
#ifdef CONFIG_KALLSYMS
@@ -662,6 +662,8 @@ unsigned long __get_wchan(struct task_st
unsigned long ra = 0;
#endif
+ if (!task || task == current || task_is_running(task))
+ goto out;
if (!task_stack_page(task))
goto out;
--- a/arch/nds32/include/asm/processor.h
+++ b/arch/nds32/include/asm/processor.h
@@ -83,7 +83,7 @@ extern struct task_struct *last_task_use
/* Prepare to copy thread state - unlazy all lazy status */
#define prepare_to_copy(tsk) do { } while (0)
-unsigned long __get_wchan(struct task_struct *p);
+unsigned long get_wchan(struct task_struct *p);
#define cpu_relax() barrier()
--- a/arch/nds32/kernel/process.c
+++ b/arch/nds32/kernel/process.c
@@ -233,12 +233,15 @@ int dump_fpu(struct pt_regs *regs, elf_f
EXPORT_SYMBOL(dump_fpu);
-unsigned long __get_wchan(struct task_struct *p)
+unsigned long get_wchan(struct task_struct *p)
{
unsigned long fp, lr;
unsigned long stack_start, stack_end;
int count = 0;
+ if (!p || p == current || task_is_running(p))
+ return 0;
+
if (IS_ENABLED(CONFIG_FRAME_POINTER)) {
stack_start = (unsigned long)end_of_stack(p);
stack_end = (unsigned long)task_stack_page(p) + THREAD_SIZE;
@@ -255,3 +258,5 @@ unsigned long __get_wchan(struct task_st
}
return 0;
}
+
+EXPORT_SYMBOL(get_wchan);
--- a/arch/nios2/include/asm/processor.h
+++ b/arch/nios2/include/asm/processor.h
@@ -69,7 +69,7 @@ static inline void release_thread(struct
{
}
-extern unsigned long __get_wchan(struct task_struct *p);
+extern unsigned long get_wchan(struct task_struct *p);
#define task_pt_regs(p) \
((struct pt_regs *)(THREAD_SIZE + task_stack_page(p)) - 1)
--- a/arch/nios2/kernel/process.c
+++ b/arch/nios2/kernel/process.c
@@ -217,12 +217,15 @@ void dump(struct pt_regs *fp)
pr_emerg("\n\n");
}
-unsigned long __get_wchan(struct task_struct *p)
+unsigned long get_wchan(struct task_struct *p)
{
unsigned long fp, pc;
unsigned long stack_page;
int count = 0;
+ if (!p || p == current || task_is_running(p))
+ return 0;
+
stack_page = (unsigned long)p;
fp = ((struct switch_stack *)p->thread.ksp)->fp; /* ;dgt2 */
do {
--- a/arch/openrisc/include/asm/processor.h
+++ b/arch/openrisc/include/asm/processor.h
@@ -73,7 +73,7 @@ struct thread_struct {
void start_thread(struct pt_regs *regs, unsigned long nip, unsigned long sp);
void release_thread(struct task_struct *);
-unsigned long __get_wchan(struct task_struct *p);
+unsigned long get_wchan(struct task_struct *p);
#define cpu_relax() barrier()
--- a/arch/openrisc/kernel/process.c
+++ b/arch/openrisc/kernel/process.c
@@ -265,7 +265,7 @@ void dump_elf_thread(elf_greg_t *dest, s
dest[35] = 0;
}
-unsigned long __get_wchan(struct task_struct *p)
+unsigned long get_wchan(struct task_struct *p)
{
/* TODO */
--- a/arch/parisc/include/asm/processor.h
+++ b/arch/parisc/include/asm/processor.h
@@ -277,7 +277,7 @@ struct mm_struct;
/* Free all resources held by a thread. */
extern void release_thread(struct task_struct *);
-extern unsigned long __get_wchan(struct task_struct *p);
+extern unsigned long get_wchan(struct task_struct *p);
#define KSTK_EIP(tsk) ((tsk)->thread.regs.iaoq[0])
#define KSTK_ESP(tsk) ((tsk)->thread.regs.gr[30])
--- a/arch/parisc/kernel/process.c
+++ b/arch/parisc/kernel/process.c
@@ -243,12 +243,15 @@ copy_thread(unsigned long clone_flags, u
}
unsigned long
-__get_wchan(struct task_struct *p)
+get_wchan(struct task_struct *p)
{
struct unwind_frame_info info;
unsigned long ip;
int count = 0;
+ if (!p || p == current || task_is_running(p))
+ return 0;
+
/*
* These bracket the sleeping functions..
*/
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -300,7 +300,7 @@ struct thread_struct {
#define task_pt_regs(tsk) ((tsk)->thread.regs)
-unsigned long __get_wchan(struct task_struct *p);
+unsigned long get_wchan(struct task_struct *p);
#define KSTK_EIP(tsk) ((tsk)->thread.regs? (tsk)->thread.regs->nip: 0)
#define KSTK_ESP(tsk) ((tsk)->thread.regs? (tsk)->thread.regs->gpr[1]: 0)
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -2111,11 +2111,14 @@ int validate_sp(unsigned long sp, struct
EXPORT_SYMBOL(validate_sp);
-static unsigned long ___get_wchan(struct task_struct *p)
+static unsigned long __get_wchan(struct task_struct *p)
{
unsigned long ip, sp;
int count = 0;
+ if (!p || p == current || task_is_running(p))
+ return 0;
+
sp = p->thread.ksp;
if (!validate_sp(sp, p, STACK_FRAME_OVERHEAD))
return 0;
@@ -2134,14 +2137,14 @@ static unsigned long ___get_wchan(struct
return 0;
}
-unsigned long __get_wchan(struct task_struct *p)
+unsigned long get_wchan(struct task_struct *p)
{
unsigned long ret;
if (!try_get_task_stack(p))
return 0;
- ret = ___get_wchan(p);
+ ret = __get_wchan(p);
put_task_stack(p);
--- a/arch/riscv/include/asm/processor.h
+++ b/arch/riscv/include/asm/processor.h
@@ -58,7 +58,7 @@ static inline void release_thread(struct
{
}
-extern unsigned long __get_wchan(struct task_struct *p);
+extern unsigned long get_wchan(struct task_struct *p);
static inline void wait_for_interrupt(void)
--- a/arch/riscv/kernel/stacktrace.c
+++ b/arch/riscv/kernel/stacktrace.c
@@ -128,14 +128,16 @@ static bool save_wchan(void *arg, unsign
return true;
}
-unsigned long __get_wchan(struct task_struct *task)
+unsigned long get_wchan(struct task_struct *task)
{
unsigned long pc = 0;
- if (!try_get_task_stack(task))
- return 0;
- walk_stackframe(task, NULL, save_wchan, &pc);
- put_task_stack(task);
+ if (likely(task && task != current && !task_is_running(task))) {
+ if (!try_get_task_stack(task))
+ return 0;
+ walk_stackframe(task, NULL, save_wchan, &pc);
+ put_task_stack(task);
+ }
return pc;
}
--- a/arch/s390/include/asm/processor.h
+++ b/arch/s390/include/asm/processor.h
@@ -192,7 +192,7 @@ static inline void release_thread(struct
void guarded_storage_release(struct task_struct *tsk);
void gs_load_bc_cb(struct pt_regs *regs);
-unsigned long __get_wchan(struct task_struct *p);
+unsigned long get_wchan(struct task_struct *p);
#define task_pt_regs(tsk) ((struct pt_regs *) \
(task_stack_page(tsk) + THREAD_SIZE) - 1)
#define KSTK_EIP(tsk) (task_pt_regs(tsk)->psw.addr)
--- a/arch/s390/kernel/process.c
+++ b/arch/s390/kernel/process.c
@@ -181,12 +181,12 @@ void execve_tail(void)
asm volatile("sfpc %0" : : "d" (0));
}
-unsigned long __get_wchan(struct task_struct *p)
+unsigned long get_wchan(struct task_struct *p)
{
struct unwind_state state;
unsigned long ip = 0;
- if (!task_stack_page(p))
+ if (!p || p == current || task_is_running(p) || !task_stack_page(p))
return 0;
if (!try_get_task_stack(p))
--- a/arch/sh/include/asm/processor_32.h
+++ b/arch/sh/include/asm/processor_32.h
@@ -180,7 +180,7 @@ static inline void show_code(struct pt_r
}
#endif
-extern unsigned long __get_wchan(struct task_struct *p);
+extern unsigned long get_wchan(struct task_struct *p);
#define KSTK_EIP(tsk) (task_pt_regs(tsk)->pc)
#define KSTK_ESP(tsk) (task_pt_regs(tsk)->regs[15])
--- a/arch/sh/kernel/process_32.c
+++ b/arch/sh/kernel/process_32.c
@@ -182,10 +182,13 @@ __switch_to(struct task_struct *prev, st
return prev;
}
-unsigned long __get_wchan(struct task_struct *p)
+unsigned long get_wchan(struct task_struct *p)
{
unsigned long pc;
+ if (!p || p == current || task_is_running(p))
+ return 0;
+
/*
* The same comment as on the Alpha applies here, too ...
*/
--- a/arch/sparc/include/asm/processor_32.h
+++ b/arch/sparc/include/asm/processor_32.h
@@ -89,7 +89,7 @@ static inline void start_thread(struct p
/* Free all resources held by a thread. */
#define release_thread(tsk) do { } while(0)
-unsigned long __get_wchan(struct task_struct *);
+unsigned long get_wchan(struct task_struct *);
#define task_pt_regs(tsk) ((tsk)->thread.kregs)
#define KSTK_EIP(tsk) ((tsk)->thread.kregs->pc)
--- a/arch/sparc/include/asm/processor_64.h
+++ b/arch/sparc/include/asm/processor_64.h
@@ -183,7 +183,7 @@ do { \
/* Free all resources held by a thread. */
#define release_thread(tsk) do { } while (0)
-unsigned long __get_wchan(struct task_struct *task);
+unsigned long get_wchan(struct task_struct *task);
#define task_pt_regs(tsk) (task_thread_info(tsk)->kregs)
#define KSTK_EIP(tsk) (task_pt_regs(tsk)->tpc)
--- a/arch/sparc/kernel/process_32.c
+++ b/arch/sparc/kernel/process_32.c
@@ -368,7 +368,7 @@ int copy_thread(unsigned long clone_flag
return 0;
}
-unsigned long __get_wchan(struct task_struct *task)
+unsigned long get_wchan(struct task_struct *task)
{
unsigned long pc, fp, bias = 0;
unsigned long task_base = (unsigned long) task;
@@ -376,6 +376,9 @@ unsigned long __get_wchan(struct task_st
struct reg_window32 *rw;
int count = 0;
+ if (!task || task == current || task_is_running(task))
+ goto out;
+
fp = task_thread_info(task)->ksp + bias;
do {
/* Bogus frame pointer? */
--- a/arch/sparc/kernel/process_64.c
+++ b/arch/sparc/kernel/process_64.c
@@ -666,7 +666,7 @@ int arch_dup_task_struct(struct task_str
return 0;
}
-unsigned long __get_wchan(struct task_struct *task)
+unsigned long get_wchan(struct task_struct *task)
{
unsigned long pc, fp, bias = 0;
struct thread_info *tp;
@@ -674,6 +674,9 @@ unsigned long __get_wchan(struct task_st
unsigned long ret = 0;
int count = 0;
+ if (!task || task == current || task_is_running(task))
+ goto out;
+
tp = task_thread_info(task);
bias = STACK_BIAS;
fp = task_thread_info(task)->ksp + bias;
--- a/arch/um/include/asm/processor-generic.h
+++ b/arch/um/include/asm/processor-generic.h
@@ -106,6 +106,6 @@ extern struct cpuinfo_um boot_cpu_data;
#define cache_line_size() (boot_cpu_data.cache_alignment)
#define KSTK_REG(tsk, reg) get_thread_reg(reg, &tsk->thread.switch_buf)
-extern unsigned long __get_wchan(struct task_struct *p);
+extern unsigned long get_wchan(struct task_struct *p);
#endif
--- a/arch/um/kernel/process.c
+++ b/arch/um/kernel/process.c
@@ -364,11 +364,14 @@ unsigned long arch_align_stack(unsigned
}
#endif
-unsigned long __get_wchan(struct task_struct *p)
+unsigned long get_wchan(struct task_struct *p)
{
unsigned long stack_page, sp, ip;
bool seen_sched = 0;
+ if ((p == NULL) || (p == current) || task_is_running(p))
+ return 0;
+
stack_page = (unsigned long) task_stack_page(p);
/* Bail if the process has no kernel stack for some reason */
if (stack_page == 0)
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -588,7 +588,7 @@ static inline void load_sp0(unsigned lon
/* Free all resources held by a thread. */
extern void release_thread(struct task_struct *);
-unsigned long __get_wchan(struct task_struct *p);
+unsigned long get_wchan(struct task_struct *p);
/*
* Generic CPUID function
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -943,10 +943,13 @@ unsigned long arch_randomize_brk(struct
* because the task might wake up and we might look at a stack
* changing under us.
*/
-unsigned long __get_wchan(struct task_struct *p)
+unsigned long get_wchan(struct task_struct *p)
{
unsigned long entry = 0;
+ if (p == current || task_is_running(p))
+ return 0;
+
stack_trace_save_tsk(p, &entry, 1, 0);
return entry;
}
--- a/arch/xtensa/include/asm/processor.h
+++ b/arch/xtensa/include/asm/processor.h
@@ -215,7 +215,7 @@ struct mm_struct;
/* Free all resources held by a thread. */
#define release_thread(thread) do { } while(0)
-extern unsigned long __get_wchan(struct task_struct *p);
+extern unsigned long get_wchan(struct task_struct *p);
#define KSTK_EIP(tsk) (task_pt_regs(tsk)->pc)
#define KSTK_ESP(tsk) (task_pt_regs(tsk)->areg[1])
--- a/arch/xtensa/kernel/process.c
+++ b/arch/xtensa/kernel/process.c
@@ -298,12 +298,15 @@ int copy_thread(unsigned long clone_flag
* These bracket the sleeping functions..
*/
-unsigned long __get_wchan(struct task_struct *p)
+unsigned long get_wchan(struct task_struct *p)
{
unsigned long sp, pc;
unsigned long stack_page = (unsigned long) task_stack_page(p);
int count = 0;
+ if (!p || p == current || task_is_running(p))
+ return 0;
+
sp = p->thread.sp;
pc = MAKE_PC_FROM_RA(p->thread.ra, p->thread.sp);
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -2030,7 +2030,6 @@ static inline void set_task_cpu(struct t
#endif /* CONFIG_SMP */
extern bool sched_task_on_rq(struct task_struct *p);
-extern unsigned long get_wchan(struct task_struct *p);
/*
* In order to reduce various lock holder preemption latencies provide an
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1960,25 +1960,6 @@ bool sched_task_on_rq(struct task_struct
return task_on_rq_queued(p);
}
-unsigned long get_wchan(struct task_struct *p)
-{
- unsigned long ip = 0;
- unsigned int state;
-
- if (!p || p == current)
- return 0;
-
- /* Only get wchan if task is blocked and we can keep it that way. */
- raw_spin_lock_irq(&p->pi_lock);
- state = READ_ONCE(p->__state);
- smp_rmb(); /* see try_to_wake_up() */
- if (state != TASK_RUNNING && state != TASK_WAKING && !p->on_rq)
- ip = __get_wchan(p);
- raw_spin_unlock_irq(&p->pi_lock);
-
- return ip;
-}
-
static inline void enqueue_task(struct rq *rq, struct task_struct *p, int flags)
{
if (!(flags & ENQUEUE_NOCLOCK))
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
