exit_thread: accept a task parameter to be exited

We need to call exit_thread from copy_process in a fail path. So make it
accept task_struct as a parameter.

[v2]
* s390: exit_thread_runtime_instr doesn't make sense to be called for
non-current tasks.
* arm: fix the comment in vfp_thread_copy
* change 'me' to 'tsk' for task_struct
* now we can change only archs that actually have exit_thread

[[e-mail]: coding-style fixes]
Signed-off-by: Jiri Slaby <[e-mail]>
Cc: "David S. Miller" <[e-mail]>
Cc: "H. Peter Anvin" <[e-mail]>
Cc: "James E.J. Bottomley" <[e-mail]>
Cc: Aurelien Jacquiot <[e-mail]>
Cc: Benjamin Herrenschmidt <[e-mail]>
Cc: Catalin Marinas <[e-mail]>
Cc: Chen Liqin <[e-mail]>
Cc: Chris Metcalf <[e-mail]>
Cc: Chris Zankel <[e-mail]>
Cc: David Howells <[e-mail]>
Cc: Fenghua Yu <[e-mail]>
Cc: Geert Uytterhoeven <[e-mail]>
Cc: Guan Xuetao <[e-mail]>
Cc: Haavard Skinnemoen <[e-mail]>
Cc: Hans-Christian Egtvedt <[e-mail]>
Cc: Heiko Carstens <[e-mail]>
Cc: Helge Deller <[e-mail]>
Cc: Ingo Molnar <[e-mail]>
Cc: Ivan Kokshaysky <[e-mail]>
Cc: James Hogan <[e-mail]>
Cc: Jeff Dike <[e-mail]>
Cc: Jesper Nilsson <[e-mail]>
Cc: Jiri Slaby <[e-mail]>
Cc: Jonas Bonn <[e-mail]>
Cc: Koichi Yasutake <[e-mail]>
Cc: Lennox Wu <[e-mail]>
Cc: Ley Foon Tan <[e-mail]>
Cc: Mark Salter <[e-mail]>
Cc: Martin Schwidefsky <[e-mail]>
Cc: Matt Turner <[e-mail]>
Cc: Max Filippov <[e-mail]>
Cc: Michael Ellerman <[e-mail]>
Cc: Michal Simek <[e-mail]>
Cc: Mikael Starvik <[e-mail]>
Cc: Paul Mackerras <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Ralf Baechle <[e-mail]>
Cc: Rich Felker <[e-mail]>
Cc: Richard Henderson <[e-mail]>
Cc: Richard Kuo <[e-mail]>
Cc: Richard Weinberger <[e-mail]>
Cc: Russell King <[e-mail]>
Cc: Steven Miao <[e-mail]>
Cc: Thomas Gleixner <[e-mail]>
Cc: Tony Luck <[e-mail]>
Cc: Vineet Gupta <[e-mail]>
Cc: Will Deacon <[e-mail]>
Cc: Yoshinori Sato <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

arch/arm/kernel/process.c

···
 /*
  * Free current thread data structures etc..
  */
-void exit_thread(void)
+void exit_thread(struct task_struct *tsk)
 {
-	thread_notify(THREAD_NOTIFY_EXIT, current_thread_info());
+	thread_notify(THREAD_NOTIFY_EXIT, task_thread_info(tsk));
 }
 
 void flush_thread(void)

arch/arm/vfp/vfpmodule.c

···
  *   - we could be preempted if tree preempt rcu is enabled, so
  *	it is unsafe to use thread->cpu.
  *  THREAD_NOTIFY_EXIT
- *   - the thread (v) will be running on the local CPU, so
- *	v === current_thread_info()
- *   - thread->cpu is the local CPU number at the time it is accessed,
- *	but may change at any time.
  *   - we could be preempted if tree preempt rcu is enabled, so
  *	it is unsafe to use thread->cpu.
  */

arch/avr32/kernel/process.c

···
 /*
  * Free current thread data structures etc
  */
-void exit_thread(void)
+void exit_thread(struct task_struct *tsk)
 {
-	ocd_disable(current);
+	ocd_disable(tsk);
 }
 
 void flush_thread(void)

arch/cris/arch-v32/kernel/process.c

···
  */
 
 extern void deconfigure_bp(long pid);
-void exit_thread(void)
+void exit_thread(struct task_struct *tsk)
 {
-	deconfigure_bp(current->pid);
+	deconfigure_bp(tsk->pid);
 }
 
 /*

arch/ia64/kernel/perfmon.c

···
 
 
 /*
- * called only from exit_thread(): task == current
- * we come here only if current has a context attached (loaded or masked)
+ * called only from exit_thread()
+ * we come here only if the task has a context attached (loaded or masked)
  */
 void
 pfm_exit_thread(struct task_struct *task)

arch/ia64/kernel/process.c

···
 }
 
 /*
- * Clean up state associated with current thread.  This is called when
+ * Clean up state associated with a thread.  This is called when
  * the thread calls exit().
  */
 void
-exit_thread (void)
+exit_thread (struct task_struct *tsk)
 {
 
-	ia64_drop_fpu(current);
+	ia64_drop_fpu(tsk);
 #ifdef CONFIG_PERFMON
        /* if needed, stop monitoring and flush state to perfmon context */
-	if (current->thread.pfm_context)
-		pfm_exit_thread(current);
+	if (tsk->thread.pfm_context)
+		pfm_exit_thread(tsk);
 
 	/* free debug register resources */
-	if (current->thread.flags & IA64_THREAD_DBG_VALID)
-		pfm_release_debug_registers(current);
+	if (tsk->thread.flags & IA64_THREAD_DBG_VALID)
+		pfm_release_debug_registers(tsk);
 #endif
 }
 

arch/metag/kernel/process.c

···
 /*
  * Free current thread data structures etc.
  */
-void exit_thread(void)
+void exit_thread(struct task_struct *tsk)
 {
-	clear_fpu(&current->thread);
-	clear_dsp(&current->thread);
+	clear_fpu(&tsk->thread);
+	clear_dsp(&tsk->thread);
 }
 
 /* TODO: figure out how to unwind the kernel stack here to figure out

arch/mn10300/kernel/process.c

···
 /*
  * free current thread data structures etc..
  */
-void exit_thread(void)
+void exit_thread(struct task_struct *tsk)
 {
-	exit_fpu(current);
+	exit_fpu(tsk);
 }
 
 void flush_thread(void)

arch/s390/kernel/process.c

···
 /*
  * Free current thread data structures etc..
  */
-void exit_thread(void)
+void exit_thread(struct task_struct *tsk)
 {
-	exit_thread_runtime_instr();
+	if (tsk == current)
+		exit_thread_runtime_instr();
 }
 
 void flush_thread(void)

arch/sh/kernel/process_64.c

···
 /*
  * Free current thread data structures etc..
  */
-void exit_thread(void)
+void exit_thread(struct task_struct *tsk)
 {
 	/*
 	 * See arch/sparc/kernel/process.c for the precedent for doing
···
 	 * which it would get safely nulled.
 	 */
 #ifdef CONFIG_SH_FPU
-	if (last_task_used_math == current) {
+	if (last_task_used_math == tsk)
 		last_task_used_math = NULL;
-	}
 #endif
 }
 

arch/sparc/kernel/process_32.c

···
 /*
  * Free current thread data structures etc..
  */
-void exit_thread(void)
+void exit_thread(struct task_struct *tsk)
 {
 #ifndef CONFIG_SMP
-	if(last_task_used_math == current) {
+	if (last_task_used_math == tsk) {
 #else
-	if (test_thread_flag(TIF_USEDFPU)) {
+	if (test_ti_thread_flag(task_thread_info(tsk), TIF_USEDFPU)) {
 #endif
 		/* Keep process from leaving FPU in a bogon state. */
 		put_psr(get_psr() | PSR_EF);
-		fpsave(&current->thread.float_regs[0], &current->thread.fsr,
-		       &current->thread.fpqueue[0], &current->thread.fpqdepth);
+		fpsave(&tsk->thread.float_regs[0], &tsk->thread.fsr,
+		       &tsk->thread.fpqueue[0], &tsk->thread.fpqdepth);
 #ifndef CONFIG_SMP
 		last_task_used_math = NULL;
 #else
-		clear_thread_flag(TIF_USEDFPU);
+		clear_ti_thread_flag(task_thread_info(tsk), TIF_USEDFPU);
 #endif
 	}
 }

arch/sparc/kernel/process_64.c

···
 }
 
 /* Free current thread data structures etc.. */
-void exit_thread(void)
+void exit_thread(struct task_struct *tsk)
 {
-	struct thread_info *t = current_thread_info();
+	struct thread_info *t = task_thread_info(tsk);
 
 	if (t->utraps) {
 		if (t->utraps[0] < 2)

arch/tile/kernel/process.c

···
 /*
  * Free current thread data structures etc..
  */
-void exit_thread(void)
+void exit_thread(struct task_struct *tsk)
 {
 #ifdef CONFIG_HARDWALL
 	/*
···
 	 * the last reference to a hardwall fd, it would already have
 	 * been released and deactivated at this point.)
 	 */
-	hardwall_deactivate_all(current);
+	hardwall_deactivate_all(tsk);
 #endif
 }
 

arch/x86/kernel/process.c

···
 /*
  * Free current thread data structures etc..
  */
-void exit_thread(void)
+void exit_thread(struct task_struct *tsk)
 {
-	struct task_struct *me = current;
-	struct thread_struct *t = &me->thread;
+	struct thread_struct *t = &tsk->thread;
 	unsigned long *bp = t->io_bitmap_ptr;
 	struct fpu *fpu = &t->fpu;
 

arch/xtensa/kernel/process.c

···
 /*
  * This is called when the thread calls exit().
  */
-void exit_thread(void)
+void exit_thread(struct task_struct *tsk)
 {
 #if XTENSA_HAVE_COPROCESSORS
-	coprocessor_release_all(current_thread_info());
+	coprocessor_release_all(task_thread_info(tsk));
 #endif
 }
 

include/linux/sched.h

···
 extern void flush_thread(void);
 
 #ifdef CONFIG_HAVE_EXIT_THREAD
-extern void exit_thread(void);
+extern void exit_thread(struct task_struct *tsk);
 #else
-static inline void exit_thread(void)
+static inline void exit_thread(struct task_struct *tsk)
 {
 }
 #endif

kernel/exit.c

···
 		disassociate_ctty(1);
 	exit_task_namespaces(tsk);
 	exit_task_work(tsk);
-	exit_thread();
+	exit_thread(tsk);
 
 	/*
 	 * Flush inherited counters to the parent - before the parent