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

Pull third pile of signal handling patches from Al Viro:
 "This time it's mostly helpers and conversions to them; there's a lot
  of stuff remaining in the tree, but that'll either go in -rc2
  (isolated bug fixes, ideally via arch maintainers' trees) or will sit
  there until the next cycle."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal:
  x86: get rid of calling do_notify_resume() when returning to kernel mode
  blackfin: check __get_user() return value
  whack-a-mole with TIF_FREEZE
  FRV: Optimise the system call exit path in entry.S [ver #2]
  FRV: Shrink TIF_WORK_MASK [ver #2]
  FRV: Prevent syscall exit tracing and notify_resume at end of kernel exceptions
  new helper: signal_delivered()
  powerpc: get rid of restore_sigmask()
  most of set_current_blocked() callers want SIGKILL/SIGSTOP removed from set
  set_restore_sigmask() is never called without SIGPENDING (and never should be)
  TIF_RESTORE_SIGMASK can be set only when TIF_SIGPENDING is set
  don't call try_to_freeze() from do_signal()
  pull clearing RESTORE_SIGMASK into block_sigmask()
  sh64: failure to build sigframe != signal without handler
  openrisc: tracehook_signal_handler() is supposed to be called on success
  new helper: sigmask_to_save()
  new helper: restore_saved_sigmask()
  new helpers: {clear,test,test_and_clear}_restore_sigmask()
  HAVE_RESTORE_SIGMASK is defined on all architectures now

2 files changed, 24 insertions, 30 deletions

diff --git a/arch/microblaze/include/asm/thread_info.h b/arch/microblaze/include/asm/thread_info.h
index 1a8ab6a5c03f..6c610234ffab 100644
--- a/arch/microblaze/include/asm/thread_info.h
+++ b/arch/microblaze/include/asm/thread_info.h
@@ -166,7 +166,23 @@ static inline void set_restore_sigmask(void)
 {
 	struct thread_info *ti = current_thread_info();
 	ti->status |= TS_RESTORE_SIGMASK;
-	set_bit(TIF_SIGPENDING, (unsigned long *)&ti->flags);
+	WARN_ON(!test_bit(TIF_SIGPENDING, (unsigned long *)&ti->flags));
+}
+static inline void clear_restore_sigmask(void)
+{
+	current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
+}
+static inline bool test_restore_sigmask(void)
+{
+	return current_thread_info()->status & TS_RESTORE_SIGMASK;
+}
+static inline bool test_and_clear_restore_sigmask(void)
+{
+	struct thread_info *ti = current_thread_info();
+	if (!(ti->status & TS_RESTORE_SIGMASK))
+		return false;
+	ti->status &= ~TS_RESTORE_SIGMASK;
+	return true;
 }
 #endif
 
diff --git a/arch/microblaze/kernel/signal.c b/arch/microblaze/kernel/signal.c
index 5d796e32786e..76b9722557db 100644
--- a/arch/microblaze/kernel/signal.c
+++ b/arch/microblaze/kernel/signal.c
@@ -41,8 +41,6 @@
 #include <asm/cacheflush.h>
 #include <asm/syscalls.h>
 
-#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
-
 asmlinkage long
 sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
 		struct pt_regs *regs)
@@ -106,7 +104,6 @@ asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
 	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
 		goto badframe;
 
-	sigdelsetmask(&set, ~_BLOCKABLE);
 	set_current_blocked(&set);
 
 	if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &rval))
@@ -310,10 +307,11 @@ do_restart:
  * OK, we're invoking a handler
  */
 
-static int
+static void
 handle_signal(unsigned long sig, struct k_sigaction *ka,
-		siginfo_t *info, sigset_t *oldset, struct pt_regs *regs)
+		siginfo_t *info, struct pt_regs *regs)
 {
+	sigset_t *oldset = sigmask_to_save();
 	int ret;
 
 	/* Set up the stack frame */
@@ -323,11 +321,9 @@ handle_signal(unsigned long sig, struct k_sigaction *ka,
 		ret = setup_rt_frame(sig, ka, NULL, oldset, regs);
 
 	if (ret)
-		return ret;
-
-	block_sigmask(ka, sig);
+		return;
 
-	return 0;
+	signal_delivered(sig, info, ka, regs, 0);
 }
 
 /*
@@ -344,33 +340,18 @@ static void do_signal(struct pt_regs *regs, int in_syscall)
 	siginfo_t info;
 	int signr;
 	struct k_sigaction ka;
-	sigset_t *oldset;
 #ifdef DEBUG_SIG
 	printk(KERN_INFO "do signal: %p %d\n", regs, in_syscall);
 	printk(KERN_INFO "do signal2: %lx %lx %ld [%lx]\n", regs->pc, regs->r1,
 			regs->r12, current_thread_info()->flags);
 #endif
 
-	if (current_thread_info()->status & TS_RESTORE_SIGMASK)
-		oldset = &current->saved_sigmask;
-	else
-		oldset = &current->blocked;
-
 	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
 	if (signr > 0) {
 		/* Whee! Actually deliver the signal. */
 		if (in_syscall)
 			handle_restart(regs, &ka, 1);
-		if (!handle_signal(signr, &ka, &info, oldset, regs)) {
-			/*
-			 * A signal was successfully delivered; the saved
-			 * sigmask will have been stored in the signal frame,
-			 * and will be restored by sigreturn, so we can simply
-			 * clear the TS_RESTORE_SIGMASK flag.
-			 */
-			current_thread_info()->status &=
-			    ~TS_RESTORE_SIGMASK;
-		}
+		handle_signal(signr, &ka, &info, regs);
 		return;
 	}
 
@@ -381,10 +362,7 @@ static void do_signal(struct pt_regs *regs, int in_syscall)
 	 * If there's no signal to deliver, we just put the saved sigmask
 	 * back.
 	 */
-	if (current_thread_info()->status & TS_RESTORE_SIGMASK) {
-		current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
-		sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
-	}
+	restore_saved_sigmask();
 }
 
 void do_notify_resume(struct pt_regs *regs, int in_syscall)