kernel: exit: cleanup release_thread()

Only x86 has own release_thread(), introduce a new weak release_thread()
function to clean empty definitions in other ARCHs.

Link: https://lkml.kernel.org/r/20220819014406.32266-1-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: Guo Ren <guoren@kernel.org>				[csky]
Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Brian Cain <bcain@quicinc.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>			[powerpc]
Acked-by: Stafford Horne <shorne@gmail.com>			[openrisc]
Acked-by: Catalin Marinas <catalin.marinas@arm.com>		[arm64]
Acked-by: Huacai Chen <chenhuacai@kernel.org>			[LoongArch]
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Chris Zankel <chris@zankel.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Guo Ren <guoren@kernel.org> [csky]
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Henderson <richard.henderson@linaro.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vineet Gupta <vgupta@kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: Xuerui Wang <kernel@xen0n.name>
Cc: Yoshinori Sato <ysato@users.osdn.me>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

33 files changed, 7 insertions, 118 deletions

diff --git a/arch/alpha/include/asm/processor.h b/arch/alpha/include/asm/processor.h
index 43e234c518b1..714abe494e5f 100644
--- a/arch/alpha/include/asm/processor.h
+++ b/arch/alpha/include/asm/processor.h
@@ -36,8 +36,6 @@ extern void start_thread(struct pt_regs *, unsigned long, unsigned long);
 
 /* Free all resources held by a thread. */
 struct task_struct;
-extern void release_thread(struct task_struct *);
-
 unsigned long __get_wchan(struct task_struct *p);
 
 #define KSTK_EIP(tsk) (task_pt_regs(tsk)->pc)
diff --git a/arch/alpha/kernel/process.c b/arch/alpha/kernel/process.c
index e2e25f8b5e76..dbf1bc5e2ad2 100644
--- a/arch/alpha/kernel/process.c
+++ b/arch/alpha/kernel/process.c
@@ -225,11 +225,6 @@ flush_thread(void)
 	current_thread_info()->pcb.unique = 0;
 }
 
-void
-release_thread(struct task_struct *dead_task)
-{
-}
-
 /*
  * Copy architecture-specific thread state
  */
diff --git a/arch/arc/include/asm/processor.h b/arch/arc/include/asm/processor.h
index 54db9d7bb562..fb844fce1ab6 100644
--- a/arch/arc/include/asm/processor.h
+++ b/arch/arc/include/asm/processor.h
@@ -43,9 +43,6 @@ struct task_struct;
 #define task_pt_regs(p) \
 	((struct pt_regs *)(THREAD_SIZE + (void *)task_stack_page(p)) - 1)
 
-/* Free all resources held by a thread */
-#define release_thread(thread) do { } while (0)
-
 /*
  * A lot of busy-wait loops in SMP are based off of non-volatile data otherwise
  * get optimised away by gcc
diff --git a/arch/arm/include/asm/processor.h b/arch/arm/include/asm/processor.h
index bdc35c0e8dfb..326864f79d18 100644
--- a/arch/arm/include/asm/processor.h
+++ b/arch/arm/include/asm/processor.h
@@ -81,9 +81,6 @@ static inline void arch_thread_struct_whitelist(unsigned long *offset,
 /* Forward declaration, a strange C thing */
 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);
 
 #define task_pt_regs(p) \
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index 3d9cace63884..712d3e6d9be9 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -232,10 +232,6 @@ void flush_thread(void)
 	thread_notify(THREAD_NOTIFY_FLUSH, thread);
 }
 
-void release_thread(struct task_struct *dead_task)
-{
-}
-
 asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
 
 int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h
index 86eb0bfe3b38..4cfb4cd1d475 100644
--- a/arch/arm64/include/asm/processor.h
+++ b/arch/arm64/include/asm/processor.h
@@ -323,9 +323,6 @@ static inline bool is_ttbr1_addr(unsigned long addr)
 /* Forward declaration, a strange C thing */
 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);
 
 void update_sctlr_el1(u64 sctlr);
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index 92bcc1768f0b..9015f49c206e 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -279,10 +279,6 @@ void flush_thread(void)
 	flush_tagged_addr_state();
 }
 
-void release_thread(struct task_struct *dead_task)
-{
-}
-
 void arch_release_task_struct(struct task_struct *tsk)
 {
 	fpsimd_release_task(tsk);
diff --git a/arch/csky/include/asm/processor.h b/arch/csky/include/asm/processor.h
index 9638206bc44f..63ad71fab30d 100644
--- a/arch/csky/include/asm/processor.h
+++ b/arch/csky/include/asm/processor.h
@@ -69,11 +69,6 @@ do {									\
 /* Forward declaration, a strange C thing */
 struct task_struct;
 
-/* Free all resources held by a thread. */
-static inline void release_thread(struct task_struct *dead_task)
-{
-}
-
 /* Prepare to copy thread state - unlazy all lazy status */
 #define prepare_to_copy(tsk)    do { } while (0)
 
diff --git a/arch/hexagon/include/asm/processor.h b/arch/hexagon/include/asm/processor.h
index 615f7e49968e..0cd39c2cdf8f 100644
--- a/arch/hexagon/include/asm/processor.h
+++ b/arch/hexagon/include/asm/processor.h
@@ -60,10 +60,6 @@ struct thread_struct {
 #define KSTK_EIP(tsk) (pt_elr(task_pt_regs(tsk)))
 #define KSTK_ESP(tsk) (pt_psp(task_pt_regs(tsk)))
 
-/*  Free all resources held by a thread; defined in process.c  */
-extern void release_thread(struct task_struct *dead_task);
-
-/* Get wait channel for task P.  */
 extern unsigned long __get_wchan(struct task_struct *p);
 
 /*  The following stuff is pretty HEXAGON specific.  */
diff --git a/arch/hexagon/kernel/process.c b/arch/hexagon/kernel/process.c
index f0552f98a7ba..e15eeaebd785 100644
--- a/arch/hexagon/kernel/process.c
+++ b/arch/hexagon/kernel/process.c
@@ -113,13 +113,6 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
 }
 
 /*
- * Release any architecture-specific resources locked by thread
- */
-void release_thread(struct task_struct *dead_task)
-{
-}
-
-/*
  * Some archs flush debug and FPU info here
  */
 void flush_thread(void)
diff --git a/arch/ia64/include/asm/processor.h b/arch/ia64/include/asm/processor.h
index 757c2f6d8d4b..d1978e004054 100644
--- a/arch/ia64/include/asm/processor.h
+++ b/arch/ia64/include/asm/processor.h
@@ -318,13 +318,6 @@ struct thread_struct {
 struct mm_struct;
 struct task_struct;
 
-/*
- * Free all resources held by a thread. This is called after the
- * parent of DEAD_TASK has collected the exit status of the task via
- * wait().
- */
-#define release_thread(dead_task)
-
 /* Get wait channel for task P.  */
 extern unsigned long __get_wchan (struct task_struct *p);
 
diff --git a/arch/loongarch/include/asm/processor.h b/arch/loongarch/include/asm/processor.h
index 1c4b4308378d..6954dc5d24e9 100644
--- a/arch/loongarch/include/asm/processor.h
+++ b/arch/loongarch/include/asm/processor.h
@@ -176,9 +176,6 @@ struct thread_struct {
 
 struct task_struct;
 
-/* Free all resources held by a thread. */
-#define release_thread(thread) do { } while (0)
-
 enum idle_boot_override {IDLE_NO_OVERRIDE = 0, IDLE_HALT, IDLE_NOMWAIT, IDLE_POLL};
 
 extern unsigned long		boot_option_idle_override;
diff --git a/arch/m68k/include/asm/processor.h b/arch/m68k/include/asm/processor.h
index d86b4009880b..7a2da780830b 100644
--- a/arch/m68k/include/asm/processor.h
+++ b/arch/m68k/include/asm/processor.h
@@ -145,11 +145,6 @@ static inline void start_thread(struct pt_regs * regs, unsigned long pc,
 /* Forward declaration, a strange C thing */
 struct task_struct;
 
-/* Free all resources held by a thread. */
-static inline void release_thread(struct task_struct *dead_task)
-{
-}
-
 unsigned long __get_wchan(struct task_struct *p);
 void show_registers(struct pt_regs *regs);
 
diff --git a/arch/microblaze/include/asm/processor.h b/arch/microblaze/include/asm/processor.h
index 7e9e92670df3..4e193c7550df 100644
--- a/arch/microblaze/include/asm/processor.h
+++ b/arch/microblaze/include/asm/processor.h
@@ -63,11 +63,6 @@ struct thread_struct {
 	.pgdir = swapper_pg_dir, \
 }
 
-/* Free all resources held by a thread. */
-static inline void release_thread(struct task_struct *dead_task)
-{
-}
-
 unsigned long __get_wchan(struct task_struct *p);
 
 /* The size allocated for kernel stacks. This _must_ be a power of two! */
diff --git a/arch/mips/include/asm/processor.h b/arch/mips/include/asm/processor.h
index 4bb24579d12e..3fde1ff72bd1 100644
--- a/arch/mips/include/asm/processor.h
+++ b/arch/mips/include/asm/processor.h
@@ -344,9 +344,6 @@ struct thread_struct {
 
 struct task_struct;
 
-/* Free all resources held by a thread. */
-#define release_thread(thread) do { } while(0)
-
 /*
  * Do necessary setup to start up a newly executed thread.
  */
diff --git a/arch/nios2/include/asm/processor.h b/arch/nios2/include/asm/processor.h
index b8125dfbcad2..8916d93d5c2d 100644
--- a/arch/nios2/include/asm/processor.h
+++ b/arch/nios2/include/asm/processor.h
@@ -64,11 +64,6 @@ extern void start_thread(struct pt_regs *regs, unsigned long pc,
 
 struct task_struct;
 
-/* Free all resources held by a thread. */
-static inline void release_thread(struct task_struct *dead_task)
-{
-}
-
 extern unsigned long __get_wchan(struct task_struct *p);
 
 #define task_pt_regs(p) \
diff --git a/arch/openrisc/include/asm/processor.h b/arch/openrisc/include/asm/processor.h
index aa1699c18add..ed9efb430afa 100644
--- a/arch/openrisc/include/asm/processor.h
+++ b/arch/openrisc/include/asm/processor.h
@@ -72,7 +72,6 @@ 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);
 
 #define cpu_relax()     barrier()
diff --git a/arch/openrisc/kernel/process.c b/arch/openrisc/kernel/process.c
index 52dc983ddeba..f94b5ec06786 100644
--- a/arch/openrisc/kernel/process.c
+++ b/arch/openrisc/kernel/process.c
@@ -125,10 +125,6 @@ void show_regs(struct pt_regs *regs)
 	show_registers(regs);
 }
 
-void release_thread(struct task_struct *dead_task)
-{
-}
-
 /*
  * Copy the thread-specific (arch specific) info from the current
  * process to the new one p
diff --git a/arch/parisc/include/asm/processor.h b/arch/parisc/include/asm/processor.h
index 4621ceb51314..a608970b249a 100644
--- a/arch/parisc/include/asm/processor.h
+++ b/arch/parisc/include/asm/processor.h
@@ -266,9 +266,6 @@ on downward growing arches, it looks like this:
 
 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);
 
 #define KSTK_EIP(tsk)	((tsk)->thread.regs.iaoq[0])
diff --git a/arch/parisc/kernel/process.c b/arch/parisc/kernel/process.c
index 7c37e09c92da..3db0e97e6c06 100644
--- a/arch/parisc/kernel/process.c
+++ b/arch/parisc/kernel/process.c
@@ -146,10 +146,6 @@ void flush_thread(void)
 	*/
 }
 
-void release_thread(struct task_struct *dead_task)
-{
-}
-
 /*
  * Idle thread support
  *
diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index fdfaae194ddd..92e332415d02 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -75,7 +75,6 @@ extern int _chrp_type;
 
 struct task_struct;
 void start_thread(struct pt_regs *regs, unsigned long fdptr, unsigned long sp);
-void release_thread(struct task_struct *);
 
 #define TS_FPR(i) fp_state.fpr[i][TS_FPROFFSET]
 #define TS_CKFPR(i) ckfp_state.fpr[i][TS_FPROFFSET]
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 0fbda89cd1bb..991cda25b9a9 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1655,11 +1655,6 @@ EXPORT_SYMBOL_GPL(set_thread_tidr);
 
 #endif /* CONFIG_PPC64 */
 
-void
-release_thread(struct task_struct *t)
-{
-}
-
 /*
  * this gets called so that we can store coprocessor state into memory and
  * copy the current task into the new thread.
diff --git a/arch/riscv/include/asm/processor.h b/arch/riscv/include/asm/processor.h
index 19eedd4af4cd..94a0590c6971 100644
--- a/arch/riscv/include/asm/processor.h
+++ b/arch/riscv/include/asm/processor.h
@@ -65,11 +65,6 @@ static inline void arch_thread_struct_whitelist(unsigned long *offset,
 extern void start_thread(struct pt_regs *regs,
 			unsigned long pc, unsigned long sp);
 
-/* Free all resources held by a thread. */
-static inline void release_thread(struct task_struct *dead_task)
-{
-}
-
 extern unsigned long __get_wchan(struct task_struct *p);
 
 
diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h
index bd66f8e34949..c52fe651eeba 100644
--- a/arch/s390/include/asm/processor.h
+++ b/arch/s390/include/asm/processor.h
@@ -186,9 +186,6 @@ struct pt_regs;
 void show_registers(struct pt_regs *regs);
 void show_cacheinfo(struct seq_file *m);
 
-/* Free all resources held by a thread. */
-static inline void release_thread(struct task_struct *tsk) { }
-
 /* Free guarded storage control block */
 void guarded_storage_release(struct task_struct *tsk);
 void gs_load_bc_cb(struct pt_regs *regs);
diff --git a/arch/sh/include/asm/processor_32.h b/arch/sh/include/asm/processor_32.h
index 45240ec6b85a..27aebf1e75a2 100644
--- a/arch/sh/include/asm/processor_32.h
+++ b/arch/sh/include/asm/processor_32.h
@@ -127,9 +127,6 @@ struct task_struct;
 
 extern void start_thread(struct pt_regs *regs, unsigned long new_pc, unsigned long new_sp);
 
-/* Free all resources held by a thread. */
-extern void release_thread(struct task_struct *);
-
 /*
  * FPU lazy state save handling.
  */
diff --git a/arch/sh/kernel/process_32.c b/arch/sh/kernel/process_32.c
index a808843375e7..92b6649d4929 100644
--- a/arch/sh/kernel/process_32.c
+++ b/arch/sh/kernel/process_32.c
@@ -84,11 +84,6 @@ void flush_thread(void)
 #endif
 }
 
-void release_thread(struct task_struct *dead_task)
-{
-	/* do nothing */
-}
-
 asmlinkage void ret_from_fork(void);
 asmlinkage void ret_from_kernel_thread(void);
 
diff --git a/arch/sparc/include/asm/processor_32.h b/arch/sparc/include/asm/processor_32.h
index b26c35336b51..ba8b70ffec08 100644
--- a/arch/sparc/include/asm/processor_32.h
+++ b/arch/sparc/include/asm/processor_32.h
@@ -80,9 +80,6 @@ static inline void start_thread(struct pt_regs * regs, unsigned long pc,
 			     : "memory");
 }
 
-/* Free all resources held by a thread. */
-#define release_thread(tsk)		do { } while(0)
-
 unsigned long __get_wchan(struct task_struct *);
 
 #define task_pt_regs(tsk) ((tsk)->thread.kregs)
diff --git a/arch/sparc/include/asm/processor_64.h b/arch/sparc/include/asm/processor_64.h
index 89850dff6b03..2667f35d5ea5 100644
--- a/arch/sparc/include/asm/processor_64.h
+++ b/arch/sparc/include/asm/processor_64.h
@@ -176,9 +176,6 @@ do { \
 	regs->tstate &= ~TSTATE_PEF;	\
 } while (0)
 
-/* Free all resources held by a thread. */
-#define release_thread(tsk)		do { } while (0)
-
 unsigned long __get_wchan(struct task_struct *task);
 
 #define task_pt_regs(tsk) (task_thread_info(tsk)->kregs)
diff --git a/arch/um/include/asm/processor-generic.h b/arch/um/include/asm/processor-generic.h
index d0fc1862da95..bb5f06480da9 100644
--- a/arch/um/include/asm/processor-generic.h
+++ b/arch/um/include/asm/processor-generic.h
@@ -55,10 +55,6 @@ struct thread_struct {
 	.request		= { 0 } \
 }
 
-static inline void release_thread(struct task_struct *task)
-{
-}
-
 /*
  * User space process size: 3GB (default).
  */
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 356308c73951..67c9d73b31fa 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -587,9 +587,6 @@ static inline void load_sp0(unsigned long sp0)
 
 #endif /* CONFIG_PARAVIRT_XXL */
 
-/* Free all resources held by a thread. */
-extern void release_thread(struct task_struct *);
-
 unsigned long __get_wchan(struct task_struct *p);
 
 /*
diff --git a/arch/xtensa/include/asm/processor.h b/arch/xtensa/include/asm/processor.h
index 76bc63127c66..5abde43c570c 100644
--- a/arch/xtensa/include/asm/processor.h
+++ b/arch/xtensa/include/asm/processor.h
@@ -221,9 +221,6 @@ struct thread_struct {
 struct task_struct;
 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);
 
 #define KSTK_EIP(tsk)		(task_pt_regs(tsk)->pc)
diff --git a/include/linux/sched/task.h b/include/linux/sched/task.h
index 81cab4b01edc..d6c48163c6de 100644
--- a/include/linux/sched/task.h
+++ b/include/linux/sched/task.h
@@ -127,6 +127,9 @@ static inline void put_task_struct_many(struct task_struct *t, int nr)
 
 void put_task_struct_rcu_user(struct task_struct *task);
 
+/* Free all architecture-specific resources held by a thread. */
+void release_thread(struct task_struct *dead_task);
+
 #ifdef CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT
 extern int arch_task_struct_size __read_mostly;
 #else
diff --git a/kernel/exit.c b/kernel/exit.c
index 84021b24f79e..f4b7b058f4e6 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -183,6 +183,10 @@ void put_task_struct_rcu_user(struct task_struct *task)
 		call_rcu(&task->rcu, delayed_put_task_struct);
 }
 
+void __weak release_thread(struct task_struct *dead_task)
+{
+}
+
 void release_task(struct task_struct *p)
 {
 	struct task_struct *leader;