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

2 files changed, 15 insertions, 30 deletions

diff --git a/arch/avr32/kernel/entry-avr32b.S b/arch/avr32/kernel/entry-avr32b.S
index 5e6beb2597a..df288418131 100644
--- a/arch/avr32/kernel/entry-avr32b.S
+++ b/arch/avr32/kernel/entry-avr32b.S
@@ -281,7 +281,7 @@ syscall_exit_work:
         ld.w    r1, r0[TI_flags]
         rjmp    1b
 
-2:      mov     r2, _TIF_SIGPENDING | _TIF_RESTORE_SIGMASK | _TIF_NOTIFY_RESUME
+2:      mov     r2, _TIF_SIGPENDING | _TIF_NOTIFY_RESUME
         tst     r1, r2
         breq    3f
         unmask_interrupts
@@ -587,7 +587,7 @@ fault_exit_work:
         ld.w    r1, r0[TI_flags]
         rjmp    fault_exit_work
 
-1:      mov     r2, _TIF_SIGPENDING | _TIF_RESTORE_SIGMASK | _TIF_NOTIFY_RESUME
+1:      mov     r2, _TIF_SIGPENDING | _TIF_NOTIFY_RESUME
         tst     r1, r2
         breq    2f
         unmask_interrupts
diff --git a/arch/avr32/kernel/signal.c b/arch/avr32/kernel/signal.c
index e7595ef74f5..c140f9b41dc 100644
--- a/arch/avr32/kernel/signal.c
+++ b/arch/avr32/kernel/signal.c
@@ -22,8 +22,6 @@
 #include <asm/ucontext.h>
 #include <asm/syscalls.h>
 
-#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
-
 asmlinkage int sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
                                struct pt_regs *regs)
 {
@@ -89,7 +87,6 @@ asmlinkage int sys_rt_sigreturn(struct pt_regs *regs)
         if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
                 goto badframe;
 
-        sigdelsetmask(&set, ~_BLOCKABLE);
         set_current_blocked(&set);
 
         if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
@@ -224,30 +221,27 @@ static inline void setup_syscall_restart(struct pt_regs *regs)
 
 static inline void
 handle_signal(unsigned long sig, struct k_sigaction *ka, siginfo_t *info,
-              sigset_t *oldset, struct pt_regs *regs, int syscall)
+              struct pt_regs *regs, int syscall)
 {
         int ret;
 
         /*
          * Set up the stack frame
          */
-        ret = setup_rt_frame(sig, ka, info, oldset, regs);
+        ret = setup_rt_frame(sig, ka, info, sigmask_to_save(), regs);
 
         /*
          * Check that the resulting registers are sane
          */
         ret |= !valid_user_regs(regs);
 
-        if (ret != 0) {
-                force_sigsegv(sig, current);
-                return;
-        }
-
         /*
          * Block the signal if we were successful.
          */
-        block_sigmask(ka, sig);
-        clear_thread_flag(TIF_RESTORE_SIGMASK);
+        if (ret != 0)
+                force_sigsegv(sig, current);
+        else
+                signal_delivered(sig, info, ka, regs, 0);
 }
 
 /*
@@ -255,7 +249,7 @@ handle_signal(unsigned long sig, struct k_sigaction *ka, siginfo_t *info,
  * doesn't want to handle. Thus you cannot kill init even with a
  * SIGKILL even by mistake.
  */
-int do_signal(struct pt_regs *regs, sigset_t *oldset, int syscall)
+static void do_signal(struct pt_regs *regs, int syscall)
 {
         siginfo_t info;
         int signr;
@@ -267,12 +261,7 @@ int do_signal(struct pt_regs *regs, sigset_t *oldset, int syscall)
          * without doing anything if so.
          */
         if (!user_mode(regs))
-                return 0;
-
-        if (test_thread_flag(TIF_RESTORE_SIGMASK))
-                oldset = &current->saved_sigmask;
-        else if (!oldset)
-                oldset = &current->blocked;
+                return;
 
         signr = get_signal_to_deliver(&info, &ka, regs, NULL);
         if (syscall) {
@@ -297,15 +286,11 @@ int do_signal(struct pt_regs *regs, sigset_t *oldset, int syscall)
 
         if (signr == 0) {
                 /* No signal to deliver -- 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);
-                }
-                return 0;
+                restore_saved_sigmask();
+                return;
         }
 
-        handle_signal(signr, &ka, &info, oldset, regs, syscall);
-        return 1;
+        handle_signal(signr, &ka, &info, regs, syscall);
 }
 
 asmlinkage void do_notify_resume(struct pt_regs *regs, struct thread_info *ti)
@@ -315,8 +300,8 @@ asmlinkage void do_notify_resume(struct pt_regs *regs, struct thread_info *ti)
         if ((sysreg_read(SR) & MODE_MASK) == MODE_SUPERVISOR)
                 syscall = 1;
 
-        if (ti->flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK))
-                do_signal(regs, &current->blocked, syscall);
+        if (ti->flags & _TIF_SIGPENDING))
+                do_signal(regs, syscall);
 
         if (ti->flags & _TIF_NOTIFY_RESUME) {
                 clear_thread_flag(TIF_NOTIFY_RESUME);