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 63f327dd5198..fd2392a17ac1 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