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

1 files changed, 8 insertions, 39 deletions

diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c
index 63f327dd519..fd2392a17ac 100644
--- a/arch/arm/kernel/signal.c
+++ b/arch/arm/kernel/signal.c
@@ -22,8 +22,6 @@
 
 #include "signal.h"
 
-#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
-
 /*
  * For ARM syscalls, we encode the syscall number into the instruction.
  */
@@ -210,10 +208,8 @@ static int restore_sigframe(struct pt_regs *regs, struct sigframe __user *sf)
 	int err;
 
 	err = __copy_from_user(&set, &sf->uc.uc_sigmask, sizeof(set));
-	if (err == 0) {
-		sigdelsetmask(&set, ~_BLOCKABLE);
+	if (err == 0)
 		set_current_blocked(&set);
-	}
 
 	__get_user_error(regs->ARM_r0, &sf->uc.uc_mcontext.arm_r0, err);
 	__get_user_error(regs->ARM_r1, &sf->uc.uc_mcontext.arm_r1, err);
@@ -528,13 +524,13 @@ setup_rt_frame(int usig, struct k_sigaction *ka, siginfo_t *info,
 /*
  * 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)
 {
 	struct thread_info *thread = current_thread_info();
 	struct task_struct *tsk = current;
+	sigset_t *oldset = sigmask_to_save();
 	int usig = sig;
 	int ret;
 
@@ -559,17 +555,9 @@ handle_signal(unsigned long sig, struct k_sigaction *ka,
 
 	if (ret != 0) {
 		force_sigsegv(sig, tsk);
-		return ret;
+		return;
 	}
-
-	/*
-	 * Block the signal if we were successful.
-	 */
-	block_sigmask(ka, sig);
-
-	tracehook_signal_handler(sig, info, ka, regs, 0);
-
-	return 0;
+	signal_delivered(sig, info, ka, regs, 0);
 }
 
 /*
@@ -617,8 +605,6 @@ static void do_signal(struct pt_regs *regs, int syscall)
 	 */
 	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
 	if (signr > 0) {
-		sigset_t *oldset;
-
 		/*
 		 * Depending on the signal settings we may need to revert the
 		 * decision to restart the system call.  But skip this if a
@@ -635,20 +621,7 @@ static void do_signal(struct pt_regs *regs, int syscall)
 			clear_thread_flag(TIF_SYSCALL_RESTARTSYS);
 		}
 
-		if (test_thread_flag(TIF_RESTORE_SIGMASK))
-			oldset = &current->saved_sigmask;
-		else
-			oldset = &current->blocked;
-		if (handle_signal(signr, &ka, &info, oldset, regs) == 0) {
-			/*
-			 * 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 TIF_RESTORE_SIGMASK flag.
-			 */
-			if (test_thread_flag(TIF_RESTORE_SIGMASK))
-				clear_thread_flag(TIF_RESTORE_SIGMASK);
-		}
+		handle_signal(signr, &ka, &info, regs);
 		return;
 	}
 
@@ -663,11 +636,7 @@ static void do_signal(struct pt_regs *regs, int syscall)
 			set_thread_flag(TIF_SYSCALL_RESTARTSYS);
 	}
 
-	/* If there's no signal to deliver, we just put the saved sigmask
-	 * back.
-	 */
-	if (test_and_clear_thread_flag(TIF_RESTORE_SIGMASK))
-		set_current_blocked(&current->saved_sigmask);
+	restore_saved_sigmask();
 }
 
 asmlinkage void