Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel…

…/git/viro/signal

Pull second pile of signal handling patches from Al Viro:
 "This one is just task_work_add() series + remaining prereqs for it.

  There probably will be another pull request from that tree this
  cycle - at least for helpers, to get them out of the way for per-arch
  fixes remaining in the tree."

Fix trivial conflict in kernel/irq/manage.c: the merge of Andrew's pile
had brought in commit 97fd75b ("kernel/irq/manage.c: use the
pr_foo() infrastructure to prefix printks") which changed one of the
pr_err() calls that this merge moves around.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal:
  keys: kill task_struct->replacement_session_keyring
  keys: kill the dummy key_replace_session_keyring()
  keys: change keyctl_session_to_parent() to use task_work_add()
  genirq: reimplement exit_irq_thread() hook via task_work_add()
  task_work_add: generic process-context callbacks
  avr32: missed _TIF_NOTIFY_RESUME on one of do_notify_resume callers
  parisc: need to check NOTIFY_RESUME when exiting from syscall
  move key_repace_session_keyring() into tracehook_notify_resume()
  TIF_NOTIFY_RESUME is defined on all targets now

arch/alpha/kernel/signal.c

@@ -590,7 +590,5 @@ do_notify_resume(struct pt_regs *regs, struct switch_stack *sw,
 	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
 		clear_thread_flag(TIF_NOTIFY_RESUME);
 		tracehook_notify_resume(regs);
-		if (current->replacement_session_keyring)
-			key_replace_session_keyring();
 	}
 }

arch/arm/kernel/signal.c

@@ -679,7 +679,5 @@ do_notify_resume(struct pt_regs *regs, unsigned int thread_flags, int syscall)
 	if (thread_flags & _TIF_NOTIFY_RESUME) {
 		clear_thread_flag(TIF_NOTIFY_RESUME);
 		tracehook_notify_resume(regs);
-		if (current->replacement_session_keyring)
-			key_replace_session_keyring();
 	}
 }

arch/avr32/kernel/entry-avr32b.S

@@ -587,7 +587,7 @@ fault_exit_work:
 	ld.w	r1, r0[TI_flags]
 	rjmp	fault_exit_work
 
-1:	mov	r2, _TIF_SIGPENDING | _TIF_RESTORE_SIGMASK
+1:	mov	r2, _TIF_SIGPENDING | _TIF_RESTORE_SIGMASK | _TIF_NOTIFY_RESUME
 	tst	r1, r2
 	breq	2f
 	unmask_interrupts

arch/avr32/kernel/signal.c

@@ -321,7 +321,5 @@ asmlinkage void do_notify_resume(struct pt_regs *regs, struct thread_info *ti)
 	if (ti->flags & _TIF_NOTIFY_RESUME) {
 		clear_thread_flag(TIF_NOTIFY_RESUME);
 		tracehook_notify_resume(regs);
-		if (current->replacement_session_keyring)
-			key_replace_session_keyring();
 	}
 }

arch/blackfin/kernel/signal.c

@@ -336,8 +336,6 @@ asmlinkage void do_notify_resume(struct pt_regs *regs)
 	if (test_thread_flag(TIF_NOTIFY_RESUME)) {
 		clear_thread_flag(TIF_NOTIFY_RESUME);
 		tracehook_notify_resume(regs);
-		if (current->replacement_session_keyring)
-			key_replace_session_keyring();
 	}
 }
 

arch/c6x/kernel/signal.c

@@ -364,7 +364,5 @@ asmlinkage void do_notify_resume(struct pt_regs *regs, u32 thread_info_flags,
 	if (thread_info_flags & (1 << TIF_NOTIFY_RESUME)) {
 		clear_thread_flag(TIF_NOTIFY_RESUME);
 		tracehook_notify_resume(regs);
-		if (current->replacement_session_keyring)
-			key_replace_session_keyring();
 	}
 }

arch/cris/kernel/ptrace.c

@@ -40,7 +40,5 @@ void do_notify_resume(int canrestart, struct pt_regs *regs,
 	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
 		clear_thread_flag(TIF_NOTIFY_RESUME);
 		tracehook_notify_resume(regs);
-		if (current->replacement_session_keyring)
-			key_replace_session_keyring();
 	}
 }

arch/frv/kernel/signal.c

@@ -562,8 +562,6 @@ asmlinkage void do_notify_resume(__u32 thread_info_flags)
 	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
 		clear_thread_flag(TIF_NOTIFY_RESUME);
 		tracehook_notify_resume(__frame);
-		if (current->replacement_session_keyring)
-			key_replace_session_keyring();
 	}
 
 } /* end do_notify_resume() */

arch/h8300/kernel/signal.c

@@ -513,7 +513,5 @@ asmlinkage void do_notify_resume(struct pt_regs *regs, u32 thread_info_flags)
 	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
 		clear_thread_flag(TIF_NOTIFY_RESUME);
 		tracehook_notify_resume(regs);
-		if (current->replacement_session_keyring)
-			key_replace_session_keyring();
 	}
 }

arch/hexagon/kernel/signal.c

@@ -273,8 +273,6 @@ void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags)
 	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
 		clear_thread_flag(TIF_NOTIFY_RESUME);
 		tracehook_notify_resume(regs);
-		if (current->replacement_session_keyring)
-			key_replace_session_keyring();
 	}
 }
 

arch/ia64/kernel/process.c

@@ -199,8 +199,6 @@ do_notify_resume_user(sigset_t *unused, struct sigscratch *scr, long in_syscall)
 	if (test_thread_flag(TIF_NOTIFY_RESUME)) {
 		clear_thread_flag(TIF_NOTIFY_RESUME);
 		tracehook_notify_resume(&scr->pt);
-		if (current->replacement_session_keyring)
-			key_replace_session_keyring();
 	}
 
 	/* copy user rbs to kernel rbs */

arch/m32r/kernel/signal.c

@@ -383,8 +383,6 @@ void do_notify_resume(struct pt_regs *regs, __u32 thread_info_flags)
 	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
 		clear_thread_flag(TIF_NOTIFY_RESUME);
 		tracehook_notify_resume(regs);
-		if (current->replacement_session_keyring)
-			key_replace_session_keyring();
 	}
 
 	clear_thread_flag(TIF_IRET);

arch/m68k/kernel/signal.c

@@ -1193,9 +1193,6 @@ void do_notify_resume(struct pt_regs *regs)
 	if (test_thread_flag(TIF_SIGPENDING))
 		do_signal(regs);
 
-	if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME)) {
+	if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME))
 		tracehook_notify_resume(regs);
-		if (current->replacement_session_keyring)
-			key_replace_session_keyring();
-	}
 }

arch/microblaze/kernel/signal.c

@@ -401,9 +401,6 @@ void do_notify_resume(struct pt_regs *regs, int in_syscall)
 	if (test_thread_flag(TIF_SIGPENDING))
 		do_signal(regs, in_syscall);
 
-	if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME)) {
+	if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME))
 		tracehook_notify_resume(regs);
-		if (current->replacement_session_keyring)
-			key_replace_session_keyring();
-	}
 }

arch/mips/kernel/signal.c

@@ -636,8 +636,6 @@ asmlinkage void do_notify_resume(struct pt_regs *regs, void *unused,
 	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
 		clear_thread_flag(TIF_NOTIFY_RESUME);
 		tracehook_notify_resume(regs);
-		if (current->replacement_session_keyring)
-			key_replace_session_keyring();
 	}
 }
 

arch/mn10300/kernel/signal.c

@@ -554,7 +554,5 @@ asmlinkage void do_notify_resume(struct pt_regs *regs, u32 thread_info_flags)
 	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
 		clear_thread_flag(TIF_NOTIFY_RESUME);
 		tracehook_notify_resume(current_frame());
-		if (current->replacement_session_keyring)
-			key_replace_session_keyring();
 	}
 }

arch/openrisc/kernel/signal.c

@@ -376,7 +376,5 @@ asmlinkage void do_notify_resume(struct pt_regs *regs)
 	if (current_thread_info()->flags & _TIF_NOTIFY_RESUME) {
 		clear_thread_flag(TIF_NOTIFY_RESUME);
 		tracehook_notify_resume(regs);
-		if (current->replacement_session_keyring)
-			key_replace_session_keyring();
 	}
 }

arch/parisc/kernel/entry.S

@@ -2032,7 +2032,7 @@ syscall_check_resched:
 	.import do_signal,code
 syscall_check_sig:
 	LDREG	TI_FLAGS-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r19
-	ldi	(_TIF_SIGPENDING|_TIF_RESTORE_SIGMASK), %r26
+	ldi	(_TIF_SIGPENDING|_TIF_RESTORE_SIGMASK|_TIF_NOTIFY_RESUME), %r26
 	and,COND(<>)	%r19, %r26, %r0
 	b,n	syscall_restore	/* skip past if we've nothing to do */
 

arch/parisc/kernel/signal.c

@@ -638,7 +638,5 @@ void do_notify_resume(struct pt_regs *regs, long in_syscall)
 	if (test_thread_flag(TIF_NOTIFY_RESUME)) {
 		clear_thread_flag(TIF_NOTIFY_RESUME);
 		tracehook_notify_resume(regs);
-		if (current->replacement_session_keyring)
-			key_replace_session_keyring();
 	}
 }

arch/powerpc/kernel/signal.c

@@ -193,8 +193,6 @@ void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags)
 	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
 		clear_thread_flag(TIF_NOTIFY_RESUME);
 		tracehook_notify_resume(regs);
-		if (current->replacement_session_keyring)
-			key_replace_session_keyring();
 	}
 }
 

arch/s390/kernel/signal.c

@@ -494,6 +494,4 @@ void do_notify_resume(struct pt_regs *regs)
 {
 	clear_thread_flag(TIF_NOTIFY_RESUME);
 	tracehook_notify_resume(regs);
-	if (current->replacement_session_keyring)
-		key_replace_session_keyring();
 }

arch/score/kernel/signal.c

@@ -356,7 +356,5 @@ asmlinkage void do_notify_resume(struct pt_regs *regs, void *unused,
 	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
 		clear_thread_flag(TIF_NOTIFY_RESUME);
 		tracehook_notify_resume(regs);
-		if (current->replacement_session_keyring)
-			key_replace_session_keyring();
 	}
 }

arch/sh/kernel/signal_32.c

@@ -626,7 +626,5 @@ asmlinkage void do_notify_resume(struct pt_regs *regs, unsigned int save_r0,
 	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
 		clear_thread_flag(TIF_NOTIFY_RESUME);
 		tracehook_notify_resume(regs);
-		if (current->replacement_session_keyring)
-			key_replace_session_keyring();
 	}
 }

arch/sh/kernel/signal_64.c

@@ -685,7 +685,5 @@ asmlinkage void do_notify_resume(struct pt_regs *regs, unsigned long thread_info
 	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
 		clear_thread_flag(TIF_NOTIFY_RESUME);
 		tracehook_notify_resume(regs);
-		if (current->replacement_session_keyring)
-			key_replace_session_keyring();
 	}
 }

arch/sparc/kernel/signal_32.c

@@ -590,8 +590,6 @@ void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0,
 	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
 		clear_thread_flag(TIF_NOTIFY_RESUME);
 		tracehook_notify_resume(regs);
-		if (current->replacement_session_keyring)
-			key_replace_session_keyring();
 	}
 }
 

arch/sparc/kernel/signal_64.c

@@ -607,8 +607,6 @@ void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0, unsigned long
 	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
 		clear_thread_flag(TIF_NOTIFY_RESUME);
 		tracehook_notify_resume(regs);
-		if (current->replacement_session_keyring)
-			key_replace_session_keyring();
 	}
 }
 

arch/tile/kernel/process.c

@@ -565,8 +565,6 @@ int do_work_pending(struct pt_regs *regs, u32 thread_info_flags)
 	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
 		clear_thread_flag(TIF_NOTIFY_RESUME);
 		tracehook_notify_resume(regs);
-		if (current->replacement_session_keyring)
-			key_replace_session_keyring();
 		return 1;
 	}
 	if (thread_info_flags & _TIF_SINGLESTEP) {

arch/um/kernel/process.c

@@ -117,11 +117,8 @@ void interrupt_end(void)
 		schedule();
 	if (test_thread_flag(TIF_SIGPENDING))
 		do_signal();
-	if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME)) {
+	if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME))
 		tracehook_notify_resume(&current->thread.regs);
-		if (current->replacement_session_keyring)
-			key_replace_session_keyring();
-	}
 }
 
 void exit_thread(void)

arch/unicore32/kernel/signal.c

@@ -464,8 +464,6 @@ asmlinkage void do_notify_resume(struct pt_regs *regs,
 	if (thread_flags & _TIF_NOTIFY_RESUME) {
 		clear_thread_flag(TIF_NOTIFY_RESUME);
 		tracehook_notify_resume(regs);
-		if (current->replacement_session_keyring)
-			key_replace_session_keyring();
 	}
 }
 

arch/x86/kernel/signal.c

@@ -827,8 +827,6 @@ do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags)
 	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
 		clear_thread_flag(TIF_NOTIFY_RESUME);
 		tracehook_notify_resume(regs);
-		if (current->replacement_session_keyring)
-			key_replace_session_keyring();
 	}
 	if (thread_info_flags & _TIF_USER_RETURN_NOTIFY)
 		fire_user_return_notifiers();

arch/xtensa/kernel/signal.c

@@ -548,9 +548,6 @@ void do_notify_resume(struct pt_regs *regs)
 	if (test_thread_flag(TIF_SIGPENDING))
 		do_signal(regs);
 
-	if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME)) {
+	if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME))
 		tracehook_notify_resume(regs);
-		if (current->replacement_session_keyring)
-			key_replace_session_keyring();
-	}
 }

include/linux/interrupt.h

@@ -142,8 +142,6 @@ request_any_context_irq(unsigned int irq, irq_handler_t handler,
 extern int __must_check
 request_percpu_irq(unsigned int irq, irq_handler_t handler,
 		   const char *devname, void __percpu *percpu_dev_id);
-
-extern void exit_irq_thread(void);
 #else
 
 extern int __must_check
@@ -177,8 +175,6 @@ request_percpu_irq(unsigned int irq, irq_handler_t handler,
 {
 	return request_irq(irq, handler, 0, devname, percpu_dev_id);
 }
-
-static inline void exit_irq_thread(void) { }
 #endif
 
 extern void free_irq(unsigned int, void *);

include/linux/key.h

@@ -308,9 +308,6 @@ static inline bool key_is_instantiated(const struct key *key)
 #ifdef CONFIG_SYSCTL
 extern ctl_table key_sysctls[];
 #endif
-
-extern void key_replace_session_keyring(void);
-
 /*
  * the userspace interface
  */
@@ -334,7 +331,6 @@ extern void key_init(void);
 #define key_fsuid_changed(t)		do { } while(0)
 #define key_fsgid_changed(t)		do { } while(0)
 #define key_init()			do { } while(0)
-#define key_replace_session_keyring()	do { } while(0)
 
 #endif /* CONFIG_KEYS */
 #endif /* __KERNEL__ */

include/linux/sched.h

@@ -1301,22 +1301,16 @@ struct task_struct {
 	unsigned sched_reset_on_fork:1;
 	unsigned sched_contributes_to_load:1;
 
-#ifdef CONFIG_GENERIC_HARDIRQS
-	/* IRQ handler threads */
-	unsigned irq_thread:1;
-#endif
-
 	pid_t pid;
 	pid_t tgid;
 
 #ifdef CONFIG_CC_STACKPROTECTOR
 	/* Canary value for the -fstack-protector gcc feature */
 	unsigned long stack_canary;
 #endif
-
-	/* 
+	/*
 	 * pointers to (original) parent process, youngest child, younger sibling,
-	 * older sibling, respectively.  (p->father can be replaced with 
+	 * older sibling, respectively.  (p->father can be replaced with
 	 * p->real_parent->pid)
 	 */
 	struct task_struct __rcu *real_parent; /* real parent process */
@@ -1363,8 +1357,6 @@ struct task_struct {
 					 * credentials (COW) */
 	const struct cred __rcu *cred;	/* effective (overridable) subjective task
 					 * credentials (COW) */
-	struct cred *replacement_session_keyring; /* for KEYCTL_SESSION_TO_PARENT */
-
 	char comm[TASK_COMM_LEN]; /* executable name excluding path
 				     - access with [gs]et_task_comm (which lock
 				       it with task_lock())
@@ -1400,6 +1392,8 @@ struct task_struct {
 	int (*notifier)(void *priv);
 	void *notifier_data;
 	sigset_t *notifier_mask;
+	struct hlist_head task_works;
+
 	struct audit_context *audit_context;
 #ifdef CONFIG_AUDITSYSCALL
 	uid_t loginuid;

include/linux/task_work.h

@@ -0,0 +1,33 @@
+#ifndef _LINUX_TASK_WORK_H
+#define _LINUX_TASK_WORK_H
+
+#include <linux/list.h>
+#include <linux/sched.h>
+
+struct task_work;
+typedef void (*task_work_func_t)(struct task_work *);
+
+struct task_work {
+	struct hlist_node hlist;
+	task_work_func_t func;
+	void *data;
+};
+
+static inline void
+init_task_work(struct task_work *twork, task_work_func_t func, void *data)
+{
+	twork->func = func;
+	twork->data = data;
+}
+
+int task_work_add(struct task_struct *task, struct task_work *twork, bool);
+struct task_work *task_work_cancel(struct task_struct *, task_work_func_t);
+void task_work_run(void);
+
+static inline void exit_task_work(struct task_struct *task)
+{
+	if (unlikely(!hlist_empty(&task->task_works)))
+		task_work_run();
+}
+
+#endif	/* _LINUX_TASK_WORK_H */