microblaze: fix signal masking

There are a couple of problems with the current signal code,

1. If we failed to setup the signal stack frame then we should not be
   masking any signals.

2. ka->sa.sa_mask is only added to the current blocked signals list if
   SA_NODEFER is set in ka->sa.sa_flags.  If we successfully setup the
   signal frame and are going to run the handler then we must honour
   sa_mask.

Acked-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Michal Simek <monstr@monstr.eu>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/arch/microblaze/kernel/signal.c b/arch/microblaze/kernel/signal.c
index 9e749c032af8086bd69390f5275fea523c39aaa2..f2c13d5a6261b3ef79ac2b7fb8a22014ca73cba7 100644 (file)
--- a/arch/microblaze/kernel/signal.c
+++ b/arch/microblaze/kernel/signal.c
@@ -169,7 +169,7 @@ get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size)
        return (void __user *)((sp - frame_size) & -8UL);
 }
 
-static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
+static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
                        sigset_t *set, struct pt_regs *regs)
 {
        struct rt_sigframe __user *frame;
@@ -267,10 +267,11 @@ static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
                current->comm, current->pid, frame, regs->pc);
 #endif
 
-       return;
+       return 0;
 
 give_sigsegv:
        force_sigsegv(sig, current);
+       return -EFAULT;
 }
 
 /* Handle restarting system calls */
@@ -314,21 +315,25 @@ static int
 handle_signal(unsigned long sig, struct k_sigaction *ka,
                siginfo_t *info, sigset_t *oldset, struct pt_regs *regs)
 {
+       int ret;
+
        /* Set up the stack frame */
        if (ka->sa.sa_flags & SA_SIGINFO)
-               setup_rt_frame(sig, ka, info, oldset, regs);
+               ret = setup_rt_frame(sig, ka, info, oldset, regs);
        else
-               setup_rt_frame(sig, ka, NULL, oldset, regs);
+               ret = setup_rt_frame(sig, ka, NULL, oldset, regs);
+
+       if (ret)
+               return ret;
 
-       if (!(ka->sa.sa_flags & SA_NODEFER)) {
-               spin_lock_irq(&current->sighand->siglock);
-               sigorsets(&current->blocked,
-                               &current->blocked, &ka->sa.sa_mask);
+       spin_lock_irq(&current->sighand->siglock);
+       sigorsets(&current->blocked, &current->blocked, &ka->sa.sa_mask);
+       if (!(ka->sa.sa_flags & SA_NODEFER))
                sigaddset(&current->blocked, sig);
-               recalc_sigpending();
-               spin_unlock_irq(&current->sighand->siglock);
-       }
-       return 1;
+       recalc_sigpending();
+       spin_unlock_irq(&current->sighand->siglock);
+
+       return 0;
 }
 
 /*
@@ -369,7 +374,7 @@ int do_signal(struct pt_regs *regs, sigset_t *oldset, int in_syscall)
                /* Whee! Actually deliver the signal. */
                if (in_syscall)
                        handle_restart(regs, &ka, 1);
-               if (handle_signal(signr, &ka, &info, oldset, regs)) {
+               if (!handle_signal(signr, &ka, &info, oldset, regs)) {
                        /*
                         * A signal was successfully delivered; the saved
                         * sigmask will have been stored in the signal frame,