[PATCH] signal-race fixes for s390

  Update s30 for the signal race fix

From: Mikael Pettersson <mikpe@csd.uu.se>

  The signal-race-fixes patch in 2.6.8-rc2-mm1 appears to be a bit broken on
  s390.

  When forcing a SIGSEGV the old code updated "*ka", where ka was a pointer
  to current's k_sigaction for SIGSEGV.  Now "ka_copy" points to a copy of
  that structure, so assigning "*ka_copy" doesn't do what we want.  Instead do
  the assignment via current->...  just like i386 and x86_64 do.

  Furthermore, the SA_ONESHOT handling wasn't deleted.  That is now handled
  by generic code in the kernel.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/s390/kernel/compat_signal.c

@@ -610,20 +610,15 @@ static void setup_rt_frame32(int sig, struct k_sigaction *ka, siginfo_t *info,
  */	
 
 void
-handle_signal32(unsigned long sig, siginfo_t *info, sigset_t *oldset,
-	struct pt_regs * regs)
+handle_signal32(unsigned long sig, struct k_sigaction *ka,
+		siginfo_t *info, sigset_t *oldset, struct pt_regs * regs)
 {
-	struct k_sigaction *ka = &current->sighand->action[sig-1];
-
 	/* Set up the stack frame */
 	if (ka->sa.sa_flags & SA_SIGINFO)
 		setup_rt_frame32(sig, ka, info, oldset, regs);
 	else
 		setup_frame32(sig, ka, oldset, regs);
 
-	if (ka->sa.sa_flags & SA_ONESHOT)
-		ka->sa.sa_handler = SIG_DFL;
-
 	if (!(ka->sa.sa_flags & SA_NODEFER)) {
 		spin_lock_irq(&current->sighand->siglock);
 		sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);

arch/s390/kernel/signal.c

@@ -420,20 +420,15 @@ static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
  */	
 
 static void
-handle_signal(unsigned long sig, siginfo_t *info, sigset_t *oldset,
-	struct pt_regs * regs)
+handle_signal(unsigned long sig, struct k_sigaction *ka,
+	      siginfo_t *info, sigset_t *oldset, struct pt_regs * regs)
 {
-	struct k_sigaction *ka = &current->sighand->action[sig-1];
-
 	/* Set up the stack frame */
 	if (ka->sa.sa_flags & SA_SIGINFO)
 		setup_rt_frame(sig, ka, info, oldset, regs);
 	else
 		setup_frame(sig, ka, oldset, regs);
 
-	if (ka->sa.sa_flags & SA_ONESHOT)
-		ka->sa.sa_handler = SIG_DFL;
-
 	if (!(ka->sa.sa_flags & SA_NODEFER)) {
 		spin_lock_irq(&current->sighand->siglock);
 		sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
@@ -457,6 +452,7 @@ int do_signal(struct pt_regs *regs, sigset_t *oldset)
 	unsigned long retval = 0, continue_addr = 0, restart_addr = 0;
 	siginfo_t info;
 	int signr;
+	struct k_sigaction ka;
 
 	/*
 	 * We want the common case to go fast, which
@@ -490,7 +486,7 @@ int do_signal(struct pt_regs *regs, sigset_t *oldset)
 
 	/* Get signal to deliver.  When running under ptrace, at this point
 	   the debugger may change all our registers ... */
-	signr = get_signal_to_deliver(&info, regs, NULL);
+	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
 
 	/* Depending on the signal settings we may need to revert the
 	   decision to restart the system call. */
@@ -509,14 +505,15 @@ int do_signal(struct pt_regs *regs, sigset_t *oldset)
 #ifdef CONFIG_S390_SUPPORT
 		if (test_thread_flag(TIF_31BIT)) {
 			extern void handle_signal32(unsigned long sig,
+						    struct k_sigaction *ka,
 						    siginfo_t *info,
 						    sigset_t *oldset,
 						    struct pt_regs *regs);
-			handle_signal32(signr, &info, oldset, regs);
+			handle_signal32(signr, &ka, &info, oldset, regs);
 			return 1;
 	        }
 #endif
-		handle_signal(signr, &info, oldset, regs);
+		handle_signal(signr, &ka, &info, oldset, regs);
 		return 1;
 	}