sparc: Don't mask signal when we can't setup signal frame.

Don't invoke the signal handler tracehook in that situation
either.

Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 26 insertions, 17 deletions

diff --git a/arch/sparc/kernel/signal_64.c b/arch/sparc/kernel/signal_64.c
index 9fa48c30037e..3f19e673e2cd 100644
--- a/arch/sparc/kernel/signal_64.c
+++ b/arch/sparc/kernel/signal_64.c
@@ -409,7 +409,7 @@ static inline void __user *get_sigframe(struct k_sigaction *ka, struct pt_regs *
         return (void __user *) sp;
 }
 
-static inline void
+static inline int
 setup_rt_frame(struct k_sigaction *ka, struct pt_regs *regs,
                int signo, sigset_t *oldset, siginfo_t *info)
 {
@@ -483,26 +483,37 @@ setup_rt_frame(struct k_sigaction *ka, struct pt_regs *regs,
         }
         /* 4. return to kernel instructions */
         regs->u_regs[UREG_I7] = (unsigned long)ka->ka_restorer;
-        return;
+        return 0;
 
 sigill:
         do_exit(SIGILL);
+        return -EINVAL;
+
 sigsegv:
         force_sigsegv(signo, current);
+        return -EFAULT;
 }
 
-static inline void handle_signal(unsigned long signr, struct k_sigaction *ka,
-                                 siginfo_t *info,
-                                 sigset_t *oldset, struct pt_regs *regs)
+static inline int handle_signal(unsigned long signr, struct k_sigaction *ka,
+                                siginfo_t *info,
+                                sigset_t *oldset, struct pt_regs *regs)
 {
-        setup_rt_frame(ka, regs, signr, oldset,
-                       (ka->sa.sa_flags & SA_SIGINFO) ? info : NULL);
+        int err;
+
+        err = setup_rt_frame(ka, regs, signr, oldset,
+                             (ka->sa.sa_flags & SA_SIGINFO) ? info : NULL);
+        if (err)
+                return err;
         spin_lock_irq(&current->sighand->siglock);
         sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
         if (!(ka->sa.sa_flags & SA_NOMASK))
                 sigaddset(&current->blocked,signr);
         recalc_sigpending();
         spin_unlock_irq(&current->sighand->siglock);
+
+        tracehook_signal_handler(signr, info, ka, regs, 0);
+
+        return 0;
 }
 
 static inline void syscall_restart(unsigned long orig_i0, struct pt_regs *regs,
@@ -571,16 +582,14 @@ static void do_signal(struct pt_regs *regs, unsigned long orig_i0)
         if (signr > 0) {
                 if (restart_syscall)
                         syscall_restart(orig_i0, regs, &ka.sa);
-                handle_signal(signr, &ka, &info, oldset, regs);
-
-                /* 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 TS_RESTORE_SIGMASK flag.
-                 */
-                current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
-
-                tracehook_signal_handler(signr, &info, &ka, regs, 0);
+                if (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 TS_RESTORE_SIGMASK flag.
+                         */
+                        current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
+                }
                 return;
         }
         if (restart_syscall &&