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, 15 insertions, 46 deletions

diff --git a/arch/s390/kernel/compat_signal.c b/arch/s390/kernel/compat_signal.c
index 377c096ca4a..3c0c19830c3 100644
--- a/arch/s390/kernel/compat_signal.c
+++ b/arch/s390/kernel/compat_signal.c
@@ -32,8 +32,6 @@
 #include "compat_ptrace.h"
 #include "entry.h"
 
-#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
-
 typedef struct 
 {
 	__u8 callee_used_stack[__SIGNAL_FRAMESIZE32];
@@ -364,7 +362,6 @@ asmlinkage long sys32_sigreturn(void)
 		goto badframe;
 	if (__copy_from_user(&set.sig, &frame->sc.oldmask, _SIGMASK_COPY_SIZE32))
 		goto badframe;
-	sigdelsetmask(&set, ~_BLOCKABLE);
 	set_current_blocked(&set);
 	if (restore_sigregs32(regs, &frame->sregs))
 		goto badframe;
@@ -390,7 +387,6 @@ asmlinkage long sys32_rt_sigreturn(void)
 		goto badframe;
 	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
 		goto badframe;
-	sigdelsetmask(&set, ~_BLOCKABLE);
 	set_current_blocked(&set);
 	if (restore_sigregs32(regs, &frame->uc.uc_mcontext))
 		goto badframe;
@@ -572,7 +568,7 @@ give_sigsegv:
  * OK, we're invoking a handler
  */	
 
-int handle_signal32(unsigned long sig, struct k_sigaction *ka,
+void handle_signal32(unsigned long sig, struct k_sigaction *ka,
 		    siginfo_t *info, sigset_t *oldset, struct pt_regs *regs)
 {
 	int ret;
@@ -583,8 +579,8 @@ int handle_signal32(unsigned long sig, struct k_sigaction *ka,
 	else
 		ret = setup_frame32(sig, ka, oldset, regs);
 	if (ret)
-		return ret;
-	block_sigmask(ka, sig);
-	return 0;
+		return;
+	signal_delivered(sig, info, ka, regs,
+				 test_thread_flag(TIF_SINGLE_STEP));
 }
 
diff --git a/arch/s390/kernel/entry.h b/arch/s390/kernel/entry.h
index 6cdddac93a2..f66a229ab0b 100644
--- a/arch/s390/kernel/entry.h
+++ b/arch/s390/kernel/entry.h
@@ -31,7 +31,7 @@ void do_per_trap(struct pt_regs *regs);
 void syscall_trace(struct pt_regs *regs, int entryexit);
 void kernel_stack_overflow(struct pt_regs * regs);
 void do_signal(struct pt_regs *regs);
-int handle_signal32(unsigned long sig, struct k_sigaction *ka,
+void handle_signal32(unsigned long sig, struct k_sigaction *ka,
 		    siginfo_t *info, sigset_t *oldset, struct pt_regs *regs);
 void do_notify_resume(struct pt_regs *regs);
 
diff --git a/arch/s390/kernel/signal.c b/arch/s390/kernel/signal.c
index 42a6e8b47f0..ac565b44aab 100644
--- a/arch/s390/kernel/signal.c
+++ b/arch/s390/kernel/signal.c
@@ -33,9 +33,6 @@
 #include <asm/switch_to.h>
 #include "entry.h"
 
-#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
-
-
 typedef struct 
 {
 	__u8 callee_used_stack[__SIGNAL_FRAMESIZE];
@@ -169,7 +166,6 @@ SYSCALL_DEFINE0(sigreturn)
 		goto badframe;
 	if (__copy_from_user(&set.sig, &frame->sc.oldmask, _SIGMASK_COPY_SIZE))
 		goto badframe;
-	sigdelsetmask(&set, ~_BLOCKABLE);
 	set_current_blocked(&set);
 	if (restore_sigregs(regs, &frame->sregs))
 		goto badframe;
@@ -189,7 +185,6 @@ SYSCALL_DEFINE0(rt_sigreturn)
 		goto badframe;
 	if (__copy_from_user(&set.sig, &frame->uc.uc_sigmask, sizeof(set)))
 		goto badframe;
-	sigdelsetmask(&set, ~_BLOCKABLE);
 	set_current_blocked(&set);
 	if (restore_sigregs(regs, &frame->uc.uc_mcontext))
 		goto badframe;
@@ -367,7 +362,7 @@ give_sigsegv:
 	return -EFAULT;
 }
 
-static int handle_signal(unsigned long sig, struct k_sigaction *ka,
+static void handle_signal(unsigned long sig, struct k_sigaction *ka,
 			 siginfo_t *info, sigset_t *oldset,
 			 struct pt_regs *regs)
 {
@@ -379,9 +374,9 @@ static int handle_signal(unsigned long sig, struct k_sigaction *ka,
 	else
 		ret = setup_frame(sig, ka, oldset, regs);
 	if (ret)
-		return ret;
-	block_sigmask(ka, sig);
-	return 0;
+		return;
+	signal_delivered(sig, info, ka, regs,
+				 test_thread_flag(TIF_SINGLE_STEP));
 }
 
 /*
@@ -398,12 +393,7 @@ void do_signal(struct pt_regs *regs)
 	siginfo_t info;
 	int signr;
 	struct k_sigaction ka;
-	sigset_t *oldset;
-
-	if (test_thread_flag(TIF_RESTORE_SIGMASK))
-		oldset = &current->saved_sigmask;
-	else
-		oldset = &current->blocked;
+	sigset_t *oldset = sigmask_to_save();
 
 	/*
 	 * Get signal to deliver. When running under ptrace, at this point
@@ -441,24 +431,10 @@ void do_signal(struct pt_regs *regs)
 		/* No longer in a system call */
 		clear_thread_flag(TIF_SYSCALL);
 
-		if ((is_compat_task() ?
-		     handle_signal32(signr, &ka, &info, oldset, regs) :
-		     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);
-
-			/*
-			 * Let tracing know that we've done the handler setup.
-			 */
-			tracehook_signal_handler(signr, &info, &ka, regs,
-					 test_thread_flag(TIF_SINGLE_STEP));
-		}
+		if (is_compat_task())
+			handle_signal32(signr, &ka, &info, oldset, regs);
+		else
+			handle_signal(signr, &ka, &info, oldset, regs);
 		return;
 	}
 
@@ -484,10 +460,7 @@ 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();
 }
 
 void do_notify_resume(struct pt_regs *regs)