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, 9 insertions, 30 deletions

diff --git a/arch/mn10300/kernel/signal.c b/arch/mn10300/kernel/signal.c
index b8b6aa1a6837..6ab0bee2a54f 100644
--- a/arch/mn10300/kernel/signal.c
+++ b/arch/mn10300/kernel/signal.c
@@ -31,8 +31,6 @@
 
 #define DEBUG_SIG 0
 
-#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
-
 /*
  * atomically swap in the new signal mask, and wait for a signal.
  */
@@ -163,7 +161,6 @@ asmlinkage long sys_sigreturn(void)
                              sizeof(frame->extramask)))
                 goto badframe;
 
-        sigdelsetmask(&set, ~_BLOCKABLE);
         set_current_blocked(&set);
 
         if (restore_sigcontext(current_frame(), &frame->sc, &d0))
@@ -191,7 +188,6 @@ asmlinkage long sys_rt_sigreturn(void)
         if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
                 goto badframe;
 
-        sigdelsetmask(&set, ~_BLOCKABLE);
         set_current_blocked(&set);
 
         if (restore_sigcontext(current_frame(), &frame->uc.uc_mcontext, &d0))
@@ -430,8 +426,9 @@ static inline void stepback(struct pt_regs *regs)
  */
 static int handle_signal(int sig,
                          siginfo_t *info, struct k_sigaction *ka,
-                         sigset_t *oldset, struct pt_regs *regs)
+                         struct pt_regs *regs)
 {
+        sigset_t *oldset = sigmask_to_save();
         int ret;
 
         /* Are we from a system call? */
@@ -461,11 +458,11 @@ static int handle_signal(int sig,
                 ret = setup_rt_frame(sig, ka, info, oldset, regs);
         else
                 ret = setup_frame(sig, ka, oldset, regs);
+        if (ret)
+                return;
 
-        if (ret == 0)
-                block_sigmask(ka, sig);
-
-        return ret;
+        signal_delivered(sig, info, ka, regs,
+                                 test_thread_flag(TIF_SINGLESTEP));
 }
 
 /*
@@ -475,7 +472,6 @@ static void do_signal(struct pt_regs *regs)
 {
         struct k_sigaction ka;
         siginfo_t info;
-        sigset_t *oldset;
         int signr;
 
         /* we want the common case to go fast, which is why we may in certain
@@ -483,23 +479,9 @@ static void do_signal(struct pt_regs *regs)
         if (!user_mode(regs))
                 return;
 
-        if (test_thread_flag(TIF_RESTORE_SIGMASK))
-                oldset = &current->saved_sigmask;
-        else
-                oldset = &current->blocked;
-
         signr = get_signal_to_deliver(&info, &ka, regs, NULL);
         if (signr > 0) {
-                if (handle_signal(signr, &info, &ka, 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);
-
-                        tracehook_signal_handler(signr, &info, &ka, regs,
-                                                 test_thread_flag(TIF_SINGLESTEP));
+                if (handle_signal(signr, &info, &ka, regs) == 0) {
                 }
 
                 return;
@@ -525,10 +507,7 @@ static void do_signal(struct pt_regs *regs)
 
         /* if there's no signal to deliver, we just put the saved sigmask
          * back */
-        if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
-                clear_thread_flag(TIF_RESTORE_SIGMASK);
-                sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
-        }
+        restore_saved_sigmask();
 }
 
 /*
@@ -548,7 +527,7 @@ asmlinkage void do_notify_resume(struct pt_regs *regs, u32 thread_info_flags)
         }
 
         /* deal with pending signal delivery */
-        if (thread_info_flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK))
+        if (thread_info_flags & _TIF_SIGPENDING)
                 do_signal(regs);
 
         if (thread_info_flags & _TIF_NOTIFY_RESUME) {