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

5 files changed, 24 insertions, 41 deletions

diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h
index a556ccc16b58..68831e9cf82f 100644
--- a/arch/powerpc/include/asm/thread_info.h
+++ b/arch/powerpc/include/asm/thread_info.h
@@ -140,7 +140,23 @@ static inline void set_restore_sigmask(void)
 {
         struct thread_info *ti = current_thread_info();
         ti->local_flags |= _TLF_RESTORE_SIGMASK;
-        set_bit(TIF_SIGPENDING, &ti->flags);
+        WARN_ON(!test_bit(TIF_SIGPENDING, &ti->flags));
+}
+static inline void clear_restore_sigmask(void)
+{
+        current_thread_info()->local_flags &= ~_TLF_RESTORE_SIGMASK;
+}
+static inline bool test_restore_sigmask(void)
+{
+        return current_thread_info()->local_flags & _TLF_RESTORE_SIGMASK;
+}
+static inline bool test_and_clear_restore_sigmask(void)
+{
+        struct thread_info *ti = current_thread_info();
+        if (!(ti->local_flags & _TLF_RESTORE_SIGMASK))
+                return false;
+        ti->local_flags &= ~_TLF_RESTORE_SIGMASK;
+        return true;
 }
 
 static inline bool test_thread_local_flags(unsigned int flags)
diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
index bfc3ec1382fb..5c023c9cf16e 100644
--- a/arch/powerpc/kernel/signal.c
+++ b/arch/powerpc/kernel/signal.c
@@ -51,16 +51,6 @@ void __user * get_sigframe(struct k_sigaction *ka, struct pt_regs *regs,
         return (void __user *)newsp;
 }
 
-
-/*
- * Restore the user process's signal mask
- */
-void restore_sigmask(sigset_t *set)
-{
-        sigdelsetmask(set, ~_BLOCKABLE);
-        set_current_blocked(set);
-}
-
 static void check_syscall_restart(struct pt_regs *regs, struct k_sigaction *ka,
                                   int has_handler)
 {
@@ -114,30 +104,21 @@ static void check_syscall_restart(struct pt_regs *regs, struct k_sigaction *ka,
 
 static int do_signal(struct pt_regs *regs)
 {
-        sigset_t *oldset;
+        sigset_t *oldset = sigmask_to_save();
         siginfo_t info;
         int signr;
         struct k_sigaction ka;
         int ret;
         int is32 = is_32bit_task();
 
-        if (current_thread_info()->local_flags & _TLF_RESTORE_SIGMASK)
-                oldset = &current->saved_sigmask;
-        else
-                oldset = &current->blocked;
-
         signr = get_signal_to_deliver(&info, &ka, regs, NULL);
 
         /* Is there any syscall restart business here ? */
         check_syscall_restart(regs, &ka, signr > 0);
 
         if (signr <= 0) {
-                struct thread_info *ti = current_thread_info();
                 /* No signal to deliver -- put the saved sigmask back */
-                if (ti->local_flags & _TLF_RESTORE_SIGMASK) {
-                        ti->local_flags &= ~_TLF_RESTORE_SIGMASK;
-                        sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
-                }
+                restore_saved_sigmask();
                 regs->trap = 0;
                 return 0;               /* no signals delivered */
         }
@@ -167,18 +148,7 @@ static int do_signal(struct pt_regs *regs)
 
         regs->trap = 0;
         if (ret) {
-                block_sigmask(&ka, signr);
-
-                /*
-                 * A signal was successfully delivered; the saved sigmask is in
-                 * its frame, and we can clear the TLF_RESTORE_SIGMASK flag.
-                 */
-                current_thread_info()->local_flags &= ~_TLF_RESTORE_SIGMASK;
-
-                /*
-                 * Let tracing know that we've done the handler setup.
-                 */
-                tracehook_signal_handler(signr, &info, &ka, regs,
+                signal_delivered(signr, &info, &ka, regs,
                                          test_thread_flag(TIF_SINGLESTEP));
         }
 
diff --git a/arch/powerpc/kernel/signal.h b/arch/powerpc/kernel/signal.h
index 8dde973aaaf5..e00acb413934 100644
--- a/arch/powerpc/kernel/signal.h
+++ b/arch/powerpc/kernel/signal.h
@@ -10,13 +10,10 @@
 #ifndef _POWERPC_ARCH_SIGNAL_H
 #define _POWERPC_ARCH_SIGNAL_H
 
-#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
-
 extern void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags);
 
 extern void __user * get_sigframe(struct k_sigaction *ka, struct pt_regs *regs,
                                   size_t frame_size, int is_32);
-extern void restore_sigmask(sigset_t *set);
 
 extern int handle_signal32(unsigned long sig, struct k_sigaction *ka,
                            siginfo_t *info, sigset_t *oldset,
diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index 61f6aff25edc..8b4c049aee20 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -919,7 +919,7 @@ static int do_setcontext(struct ucontext __user *ucp, struct pt_regs *regs, int
         if (!access_ok(VERIFY_READ, mcp, sizeof(*mcp)))
                 return -EFAULT;
 #endif
-        restore_sigmask(&set);
+        set_current_blocked(&set);
         if (restore_user_regs(regs, mcp, sig))
                 return -EFAULT;
 
@@ -1273,7 +1273,7 @@ long sys_sigreturn(int r3, int r4, int r5, int r6, int r7, int r8,
         set.sig[0] = sigctx.oldmask;
         set.sig[1] = sigctx._unused[3];
 #endif
-        restore_sigmask(&set);
+        set_current_blocked(&set);
 
         sr = (struct mcontext __user *)from_user_ptr(sigctx.regs);
         addr = sr;
diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
index 2692efdb154e..d183f8719a50 100644
--- a/arch/powerpc/kernel/signal_64.c
+++ b/arch/powerpc/kernel/signal_64.c
@@ -335,7 +335,7 @@ int sys_swapcontext(struct ucontext __user *old_ctx,
 
         if (__copy_from_user(&set, &new_ctx->uc_sigmask, sizeof(set)))
                 do_exit(SIGSEGV);
-        restore_sigmask(&set);
+        set_current_blocked(&set);
         if (restore_sigcontext(regs, NULL, 0, &new_ctx->uc_mcontext))
                 do_exit(SIGSEGV);
 
@@ -364,7 +364,7 @@ int sys_rt_sigreturn(unsigned long r3, unsigned long r4, unsigned long r5,
 
         if (__copy_from_user(&set, &uc->uc_sigmask, sizeof(set)))
                 goto badframe;
-        restore_sigmask(&set);
+        set_current_blocked(&set);
         if (restore_sigcontext(regs, NULL, 1, &uc->uc_mcontext))
                 goto badframe;