--- /dev/null
+From d94be04eac8c75c46ce4ee934f9f0cb466c136bc Mon Sep 17 00:00:00 2001
+From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+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@linuxfoundation.org>
+
+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@gmail.com>
+Reported-by: Thorsten Leemhuis <linux@leemhuis.info>
+Link: https://lore.kernel.org/r/ed000478-2a60-0066-c337-a04bffc112b1@leemhuis.info
+Cc: Stephen Rothwell <sfr@canb.auug.org.au>
+Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
+Cc: Kees Cook <keescook@chromium.org>
+Cc: Geert Uytterhoeven <geert@linux-m68k.org>
+Cc: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
+Cc: Mark Rutland <mark.rutland@arm.com>
+Cc: Sasha Levin <sashal@kernel.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ 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))
projects / thirdparty / kernel / stable-queue.git / commitdiff
