[SPARC]: Add support for *at(), ppoll, and pselect syscalls.

This also includes by necessity _TIF_RESTORE_SIGMASK support,
which actually resulted in a lot of cleanups.

The sparc signal handling code is quite a mess and I should
clean it up some day.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 31 insertions, 86 deletions

diff --git a/arch/sparc/kernel/signal.c b/arch/sparc/kernel/signal.c
index 5f34d7dc2b89..0748d8147bbf 100644
--- a/arch/sparc/kernel/signal.c
+++ b/arch/sparc/kernel/signal.c
@@ -35,9 +35,6 @@ extern void fpsave(unsigned long *fpregs, unsigned long *fsr,
                    void *fpqueue, unsigned long *fpqdepth);
 extern void fpload(unsigned long *fpregs, unsigned long *fsr);
 
-asmlinkage int do_signal(sigset_t *oldset, struct pt_regs * regs,
-                         unsigned long orig_o0, int restart_syscall);
-
 /* Signal frames: the original one (compatible with SunOS):
  *
  * Set up a signal frame... Make the stack look the way SunOS
@@ -95,98 +92,30 @@ struct rt_signal_frame {
 #define NF_ALIGNEDSZ  (((sizeof(struct new_signal_frame) + 7) & (~7)))
 #define RT_ALIGNEDSZ  (((sizeof(struct rt_signal_frame) + 7) & (~7)))
 
-/*
- * atomically swap in the new signal mask, and wait for a signal.
- * This is really tricky on the Sparc, watch out...
- */
-asmlinkage void _sigpause_common(old_sigset_t set, struct pt_regs *regs)
+static int _sigpause_common(old_sigset_t set)
 {
-        sigset_t saveset;
-
         set &= _BLOCKABLE;
         spin_lock_irq(&current->sighand->siglock);
-        saveset = current->blocked;
+        current->saved_sigmask = current->blocked;
         siginitset(&current->blocked, set);
         recalc_sigpending();
         spin_unlock_irq(&current->sighand->siglock);
 
-        regs->pc = regs->npc;
-        regs->npc += 4;
-
-        /* Condition codes and return value where set here for sigpause,
-         * and so got used by setup_frame, which again causes sigreturn()
-         * to return -EINTR.
-         */
-        while (1) {
-                current->state = TASK_INTERRUPTIBLE;
-                schedule();
-                /*
-                 * Return -EINTR and set condition code here,
-                 * so the interrupted system call actually returns
-                 * these.
-                 */
-                regs->psr |= PSR_C;
-                regs->u_regs[UREG_I0] = EINTR;
-                if (do_signal(&saveset, regs, 0, 0))
-                        return;
-        }
-}
+        current->state = TASK_INTERRUPTIBLE;
+        schedule();
+        set_thread_flag(TIF_RESTORE_SIGMASK);
 
-asmlinkage void do_sigpause(unsigned int set, struct pt_regs *regs)
-{
-        _sigpause_common(set, regs);
+        return -ERESTARTNOHAND;
 }
 
-asmlinkage void do_sigsuspend (struct pt_regs *regs)
+asmlinkage int sys_sigpause(unsigned int set)
 {
-        _sigpause_common(regs->u_regs[UREG_I0], regs);
+        return _sigpause_common(set);
 }
 
-asmlinkage void do_rt_sigsuspend(sigset_t __user *uset, size_t sigsetsize,
-                                 struct pt_regs *regs)
+asmlinkage int sys_sigsuspend(old_sigset_t set)
 {
-        sigset_t oldset, set;
-
-        /* XXX: Don't preclude handling different sized sigset_t's.  */
-        if (sigsetsize != sizeof(sigset_t)) {
-                regs->psr |= PSR_C;
-                regs->u_regs[UREG_I0] = EINVAL;
-                return;
-        }
-
-        if (copy_from_user(&set, uset, sizeof(set))) {
-                regs->psr |= PSR_C;
-                regs->u_regs[UREG_I0] = EFAULT;
-                return;
-        }
-
-        sigdelsetmask(&set, ~_BLOCKABLE);
-        spin_lock_irq(&current->sighand->siglock);
-        oldset = current->blocked;
-        current->blocked = set;
-        recalc_sigpending();
-        spin_unlock_irq(&current->sighand->siglock);
-
-        regs->pc = regs->npc;
-        regs->npc += 4;
-
-        /* Condition codes and return value where set here for sigpause,
-         * and so got used by setup_frame, which again causes sigreturn()
-         * to return -EINTR.
-         */
-        while (1) {
-                current->state = TASK_INTERRUPTIBLE;
-                schedule();
-                /*
-                 * Return -EINTR and set condition code here,
-                 * so the interrupted system call actually returns
-                 * these.
-                 */
-                regs->psr |= PSR_C;
-                regs->u_regs[UREG_I0] = EINTR;
-                if (do_signal(&oldset, regs, 0, 0))
-                        return;
-        }
+        return _sigpause_common(set);
 }
 
 static inline int
@@ -1067,13 +996,13 @@ static inline void syscall_restart(unsigned long orig_i0, struct pt_regs *regs,
  * want to handle. Thus you cannot kill init even with a SIGKILL even by
  * mistake.
  */
-asmlinkage int do_signal(sigset_t *oldset, struct pt_regs * regs,
-                         unsigned long orig_i0, int restart_syscall)
+asmlinkage void do_signal(struct pt_regs * regs, unsigned long orig_i0, int restart_syscall)
 {
         siginfo_t info;
         struct sparc_deliver_cookie cookie;
         struct k_sigaction ka;
         int signr;
+        sigset_t *oldset;
 
         /*
          * XXX Disable svr4 signal handling until solaris emulation works.
@@ -1089,7 +1018,9 @@ asmlinkage int do_signal(sigset_t *oldset, struct pt_regs * regs,
         cookie.restart_syscall = restart_syscall;
         cookie.orig_i0 = orig_i0;
 
-        if (!oldset)
+        if (test_thread_flag(TIF_RESTORE_SIGMASK))
+                oldset = &current->saved_sigmask;
+        else
                 oldset = &current->blocked;
 
         signr = get_signal_to_deliver(&info, &ka, regs, &cookie);
@@ -1098,7 +1029,14 @@ asmlinkage int do_signal(sigset_t *oldset, struct pt_regs * regs,
                         syscall_restart(cookie.orig_i0, regs, &ka.sa);
                 handle_signal(signr, &ka, &info, oldset,
                               regs, svr4_signal);
-                return 1;
+                /* 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);
+                return;
         }
         if (cookie.restart_syscall &&
             (regs->u_regs[UREG_I0] == ERESTARTNOHAND ||
@@ -1115,7 +1053,14 @@ asmlinkage int do_signal(sigset_t *oldset, struct pt_regs * regs,
                 regs->pc -= 4;
                 regs->npc -= 4;
         }
-        return 0;
+
+        /* 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);
+        }
 }
 
 asmlinkage int