alpha: support new syscalls

Some of the new syscalls require supporting TIF_RESTORE_SIGMASK.

Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 63 insertions, 47 deletions

diff --git a/arch/alpha/kernel/signal.c b/arch/alpha/kernel/signal.c
index 7f64aa767d5a..410af4f3140e 100644
--- a/arch/alpha/kernel/signal.c
+++ b/arch/alpha/kernel/signal.c
@@ -32,8 +32,8 @@
 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
 
 asmlinkage void ret_from_sys_call(void);
-static int do_signal(sigset_t *, struct pt_regs *, struct switch_stack *,
-                     unsigned long, unsigned long);
+static void do_signal(struct pt_regs *, struct switch_stack *,
+                      unsigned long, unsigned long);
 
 
 /*
@@ -146,11 +146,9 @@ sys_rt_sigaction(int sig, const struct sigaction __user *act,
 asmlinkage int
 do_sigsuspend(old_sigset_t mask, struct pt_regs *regs, struct switch_stack *sw)
 {
-        sigset_t oldset;
-
         mask &= _BLOCKABLE;
         spin_lock_irq(&current->sighand->siglock);
-        oldset = current->blocked;
+        current->saved_sigmask = current->blocked;
         siginitset(&current->blocked, mask);
         recalc_sigpending();
         spin_unlock_irq(&current->sighand->siglock);
@@ -160,19 +158,17 @@ do_sigsuspend(old_sigset_t mask, struct pt_regs *regs, struct switch_stack *sw)
         regs->r0 = EINTR;
         regs->r19 = 1;
 
-        while (1) {
-                current->state = TASK_INTERRUPTIBLE;
-                schedule();
-                if (do_signal(&oldset, regs, sw, 0, 0))
-                        return -EINTR;
-        }
+        current->state = TASK_INTERRUPTIBLE;
+        schedule();
+        set_thread_flag(TIF_RESTORE_SIGMASK);
+        return -ERESTARTNOHAND;
 }
 
 asmlinkage int
 do_rt_sigsuspend(sigset_t __user *uset, size_t sigsetsize,
                  struct pt_regs *regs, struct switch_stack *sw)
 {
-        sigset_t oldset, set;
+        sigset_t set;
 
         /* XXX: Don't preclude handling different sized sigset_t's.  */
         if (sigsetsize != sizeof(sigset_t))
@@ -182,7 +178,7 @@ do_rt_sigsuspend(sigset_t __user *uset, size_t sigsetsize,
 
         sigdelsetmask(&set, ~_BLOCKABLE);
         spin_lock_irq(&current->sighand->siglock);
-        oldset = current->blocked;
+        current->saved_sigmask = current->blocked;
         current->blocked = set;
         recalc_sigpending();
         spin_unlock_irq(&current->sighand->siglock);
@@ -192,12 +188,10 @@ do_rt_sigsuspend(sigset_t __user *uset, size_t sigsetsize,
         regs->r0 = EINTR;
         regs->r19 = 1;
 
-        while (1) {
-                current->state = TASK_INTERRUPTIBLE;
-                schedule();
-                if (do_signal(&oldset, regs, sw, 0, 0))
-                        return -EINTR;
-        }
+        current->state = TASK_INTERRUPTIBLE;
+        schedule();
+        set_thread_flag(TIF_RESTORE_SIGMASK);
+        return -ERESTARTNOHAND;
 }
 
 asmlinkage int
@@ -436,7 +430,7 @@ setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
         return err;
 }
 
-static void
+static int
 setup_frame(int sig, struct k_sigaction *ka, sigset_t *set,
             struct pt_regs *regs, struct switch_stack * sw)
 {
@@ -481,13 +475,14 @@ setup_frame(int sig, struct k_sigaction *ka, sigset_t *set,
                 current->comm, current->pid, frame, regs->pc, regs->r26);
 #endif
 
-        return;
+        return 0;
 
 give_sigsegv:
         force_sigsegv(sig, current);
+        return -EFAULT;
 }
 
-static void
+static int
 setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
                sigset_t *set, struct pt_regs *regs, struct switch_stack * sw)
 {
@@ -543,34 +538,38 @@ setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
                 current->comm, current->pid, frame, regs->pc, regs->r26);
 #endif
 
-        return;
+        return 0;
 
 give_sigsegv:
         force_sigsegv(sig, current);
+        return -EFAULT;
 }
 
 
 /*
  * OK, we're invoking a handler.
  */
-static inline void
+static inline int
 handle_signal(int sig, struct k_sigaction *ka, siginfo_t *info,
               sigset_t *oldset, struct pt_regs * regs, struct switch_stack *sw)
 {
+        int ret;
+
         if (ka->sa.sa_flags & SA_SIGINFO)
-                setup_rt_frame(sig, ka, info, oldset, regs, sw);
+                ret = setup_rt_frame(sig, ka, info, oldset, regs, sw);
         else
-                setup_frame(sig, ka, oldset, regs, sw);
+                ret = setup_frame(sig, ka, oldset, regs, sw);
 
-        if (ka->sa.sa_flags & SA_RESETHAND)
-                ka->sa.sa_handler = SIG_DFL;
+        if (ret == 0) {
+                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);
+        }
 
-        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 ret;
 }
 
 static inline void
@@ -611,30 +610,42 @@ syscall_restart(unsigned long r0, unsigned long r19,
  * restart. "r0" is also used as an indicator whether we can restart at
  * all (if we get here from anything but a syscall return, it will be 0)
  */
-static int
-do_signal(sigset_t *oldset, struct pt_regs * regs, struct switch_stack * sw,
+static void
+do_signal(struct pt_regs * regs, struct switch_stack * sw,
           unsigned long r0, unsigned long r19)
 {
         siginfo_t info;
         int signr;
         unsigned long single_stepping = ptrace_cancel_bpt(current);
         struct k_sigaction ka;
+        sigset_t *oldset;
 
-        if (!oldset)
+        if (test_thread_flag(TIF_RESTORE_SIGMASK))
+                oldset = &current->saved_sigmask;
+        else
                 oldset = &current->blocked;
 
         /* This lets the debugger run, ... */
         signr = get_signal_to_deliver(&info, &ka, regs, NULL);
+
         /* ... so re-check the single stepping. */
         single_stepping |= ptrace_cancel_bpt(current);
 
         if (signr > 0) {
                 /* Whee!  Actually deliver the signal.  */
-                if (r0) syscall_restart(r0, r19, regs, &ka);
-                handle_signal(signr, &ka, &info, oldset, regs, sw);
+                if (r0)
+                        syscall_restart(r0, r19, regs, &ka);
+                if (handle_signal(signr, &ka, &info, oldset, regs, sw) == 0) {
+                        /* A signal was successfully delivered, and the
+                           saved sigmask was stored on the signal frame,
+                           and will be restored by sigreturn.  So we can
+                           simply clear the restore sigmask flag.  */
+                        if (test_thread_flag(TIF_RESTORE_SIGMASK))
+                                clear_thread_flag(TIF_RESTORE_SIGMASK);
+                }
                 if (single_stepping) 
                         ptrace_set_bpt(current); /* re-set bpt */
-                return 1;
+                return;
         }
 
         if (r0) {
@@ -654,17 +665,22 @@ do_signal(sigset_t *oldset, struct pt_regs * regs, struct switch_stack * sw,
                         break;
                 }
         }
+
+        /* If there's no signal to deliver, we just restore the saved mask.  */
+        if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
+                clear_thread_flag(TIF_RESTORE_SIGMASK);
+                sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
+        }
+
         if (single_stepping)
                 ptrace_set_bpt(current);        /* re-set breakpoint */
-
-        return 0;
 }
 
 void
-do_notify_resume(sigset_t *oldset, struct pt_regs *regs,
-                 struct switch_stack *sw, unsigned long r0,
-                 unsigned long r19, unsigned long thread_info_flags)
+do_notify_resume(struct pt_regs *regs, struct switch_stack *sw,
+                 unsigned long thread_info_flags,
+                 unsigned long r0, unsigned long r19)
 {
-        if (thread_info_flags & _TIF_SIGPENDING)
-                do_signal(oldset, regs, sw, r0, r19);
+        if (thread_info_flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK))
+                do_signal(regs, sw, r0, r19);
 }