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

3 files changed, 35 insertions, 3 deletions

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 660c8ae93471..f34437e835a7 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -2207,6 +2207,20 @@ extern int send_sigqueue(struct sigqueue *,  struct task_struct *, int group);
 extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *);
 extern int do_sigaltstack(const stack_t __user *, stack_t __user *, unsigned long);
 
+static inline void restore_saved_sigmask(void)
+{
+        if (test_and_clear_restore_sigmask())
+                __set_current_blocked(&current->saved_sigmask);
+}
+
+static inline sigset_t *sigmask_to_save(void)
+{
+        sigset_t *res = &current->blocked;
+        if (unlikely(test_restore_sigmask()))
+                res = &current->saved_sigmask;
+        return res;
+}
+
 static inline int kill_cad_pid(int sig, int priv)
 {
         return kill_pid(cad_pid, sig, priv);
diff --git a/include/linux/signal.h b/include/linux/signal.h
index 17046cc484bc..26b424adc842 100644
--- a/include/linux/signal.h
+++ b/include/linux/signal.h
@@ -250,12 +250,13 @@ extern long do_sigpending(void __user *, unsigned long);
 extern int do_sigtimedwait(const sigset_t *, siginfo_t *,
                                 const struct timespec *);
 extern int sigprocmask(int, sigset_t *, sigset_t *);
-extern void set_current_blocked(const sigset_t *);
+extern void set_current_blocked(sigset_t *);
+extern void __set_current_blocked(const sigset_t *);
 extern int show_unhandled_signals;
 extern int sigsuspend(sigset_t *);
 
 extern int get_signal_to_deliver(siginfo_t *info, struct k_sigaction *return_ka, struct pt_regs *regs, void *cookie);
-extern void block_sigmask(struct k_sigaction *ka, int signr);
+extern void signal_delivered(int sig, siginfo_t *info, struct k_sigaction *ka, struct pt_regs *regs, int stepping);
 extern void exit_signals(struct task_struct *tsk);
 
 extern struct kmem_cache *sighand_cachep;
diff --git a/include/linux/thread_info.h b/include/linux/thread_info.h
index db78775eff3b..ccc1899bd62e 100644
--- a/include/linux/thread_info.h
+++ b/include/linux/thread_info.h
@@ -8,6 +8,7 @@
 #define _LINUX_THREAD_INFO_H
 
 #include <linux/types.h>
+#include <linux/bug.h>
 
 struct timespec;
 struct compat_timespec;
@@ -125,10 +126,26 @@ static inline int test_ti_thread_flag(struct thread_info *ti, int flag)
 static inline void set_restore_sigmask(void)
 {
         set_thread_flag(TIF_RESTORE_SIGMASK);
-        set_thread_flag(TIF_SIGPENDING);
+        WARN_ON(!test_thread_flag(TIF_SIGPENDING));
+}
+static inline void clear_restore_sigmask(void)
+{
+        clear_thread_flag(TIF_RESTORE_SIGMASK);
+}
+static inline bool test_restore_sigmask(void)
+{
+        return test_thread_flag(TIF_RESTORE_SIGMASK);
+}
+static inline bool test_and_clear_restore_sigmask(void)
+{
+        return test_and_clear_thread_flag(TIF_RESTORE_SIGMASK);
 }
 #endif  /* TIF_RESTORE_SIGMASK && !HAVE_SET_RESTORE_SIGMASK */
 
+#ifndef HAVE_SET_RESTORE_SIGMASK
+#error "no set_restore_sigmask() provided and default one won't work"
+#endif
+
 #endif  /* __KERNEL__ */
 
 #endif /* _LINUX_THREAD_INFO_H */