[PATCH] kernel: exit: cleanup release_thread()

Kefeng Wang
2022-08-19T01:39:51Z

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

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
---
arch/alpha/include/asm/processor.h | 2 --
arch/alpha/kernel/process.c | 5 -----
arch/arc/include/asm/processor.h | 3 ---
arch/arm/include/asm/processor.h | 3 ---
arch/arm/kernel/process.c | 4 ----
arch/arm64/include/asm/processor.h | 3 ---
arch/arm64/kernel/process.c | 4 ----
arch/csky/include/asm/processor.h | 5 -----
arch/hexagon/include/asm/processor.h | 4 ----
arch/hexagon/kernel/process.c | 7 -------
arch/ia64/include/asm/processor.h | 7 -------
arch/loongarch/include/asm/processor.h | 3 ---
arch/m68k/include/asm/processor.h | 5 -----
arch/microblaze/include/asm/processor.h | 5 -----
arch/mips/include/asm/processor.h | 3 ---
arch/nios2/include/asm/processor.h | 5 -----
arch/openrisc/include/asm/processor.h | 1 -
arch/openrisc/kernel/process.c | 4 ----
arch/parisc/include/asm/processor.h | 3 ---
arch/parisc/kernel/process.c | 4 ----
arch/powerpc/include/asm/processor.h | 1 -
arch/powerpc/kernel/process.c | 5 -----
arch/riscv/include/asm/processor.h | 5 -----
arch/s390/include/asm/processor.h | 3 ---
arch/sh/include/asm/processor_32.h | 3 ---
arch/sh/kernel/process_32.c | 5 -----
arch/sparc/include/asm/processor_32.h | 3 ---
arch/sparc/include/asm/processor_64.h | 3 ---
arch/um/include/asm/processor-generic.h | 4 ----
arch/x86/include/asm/processor.h | 3 ---
arch/xtensa/include/asm/processor.h | 3 ---
include/linux/sched/task.h | 3 +++
kernel/exit.c | 4 ++++
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
@@ -112,13 +112,6 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
return 0;
}

-/*
- * Release any architecture-specific resources locked by thread
- */
-void release_thread(struct task_struct *dead_task)
-{
-}
-
/*
* Some archs flush debug and FPU info here
*/
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 80376b4ac763..30cabf933fed 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;
--
2.35.3