[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, 40 insertions, 111 deletions

diff --git a/arch/sparc64/kernel/signal.c b/arch/sparc64/kernel/signal.c
index 60f5dfabb1e1..ca11a4c457d4 100644
--- a/arch/sparc64/kernel/signal.c
+++ b/arch/sparc64/kernel/signal.c
@@ -36,9 +36,6 @@
 
 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
 
-static int do_signal(sigset_t *oldset, struct pt_regs * regs,
-                     unsigned long orig_o0, int ret_from_syscall);
-
 /* {set, get}context() needed for 64-bit SparcLinux userland. */
 asmlinkage void sparc64_set_context(struct pt_regs *regs)
 {
@@ -242,114 +239,29 @@ struct rt_signal_frame {
 /* Align macros */
 #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 long _sigpause_common(old_sigset_t set)
 {
-        sigset_t saveset;
-
-#ifdef CONFIG_SPARC32_COMPAT
-        if (test_thread_flag(TIF_32BIT)) {
-                extern asmlinkage void _sigpause32_common(compat_old_sigset_t,
-                                                          struct pt_regs *);
-                _sigpause32_common(set, regs);
-                return;
-        }
-#endif
         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);
-        
-        if (test_thread_flag(TIF_32BIT)) {
-                regs->tpc = (regs->tnpc & 0xffffffff);
-                regs->tnpc = (regs->tnpc + 4) & 0xffffffff;
-        } else {
-                regs->tpc = regs->tnpc;
-                regs->tnpc += 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->tstate |= (TSTATE_ICARRY|TSTATE_XCARRY);
-                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);
+        return -ERESTARTNOHAND;
 }
 
-asmlinkage void do_sigpause(unsigned int set, struct pt_regs *regs)
+asmlinkage long sys_sigpause(unsigned int set)
 {
-        _sigpause_common(set, regs);
+        return _sigpause_common(set);
 }
 
-asmlinkage void do_sigsuspend(struct pt_regs *regs)
+asmlinkage long sys_sigsuspend(old_sigset_t set)
 {
-        _sigpause_common(regs->u_regs[UREG_I0], regs);
-}
-
-asmlinkage void do_rt_sigsuspend(sigset_t __user *uset, size_t sigsetsize, struct pt_regs *regs)
-{
-        sigset_t oldset, set;
-        
-        /* XXX: Don't preclude handling different sized sigset_t's.  */
-        if (sigsetsize != sizeof(sigset_t)) {
-                regs->tstate |= (TSTATE_ICARRY|TSTATE_XCARRY);
-                regs->u_regs[UREG_I0] = EINVAL;
-                return;
-        }
-        if (copy_from_user(&set, uset, sizeof(set))) {
-                regs->tstate |= (TSTATE_ICARRY|TSTATE_XCARRY);
-                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);
-        
-        if (test_thread_flag(TIF_32BIT)) {
-                regs->tpc = (regs->tnpc & 0xffffffff);
-                regs->tnpc = (regs->tnpc + 4) & 0xffffffff;
-        } else {
-                regs->tpc = regs->tnpc;
-                regs->tnpc += 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->tstate |= (TSTATE_ICARRY|TSTATE_XCARRY);
-                regs->u_regs[UREG_I0] = EINTR;
-                if (do_signal(&oldset, regs, 0, 0))
-                        return;
-        }
+        return _sigpause_common(set);
 }
 
 static inline int
@@ -607,26 +519,29 @@ 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.
  */
-static int do_signal(sigset_t *oldset, struct pt_regs * regs,
-                     unsigned long orig_i0, int restart_syscall)
+static void do_signal(struct pt_regs *regs, unsigned long orig_i0, int restart_syscall)
 {
         siginfo_t info;
         struct signal_deliver_cookie cookie;
         struct k_sigaction ka;
         int signr;
+        sigset_t *oldset;
         
         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;
 
 #ifdef CONFIG_SPARC32_COMPAT
         if (test_thread_flag(TIF_32BIT)) {
-                extern int do_signal32(sigset_t *, struct pt_regs *,
-                                       unsigned long, int);
-                return do_signal32(oldset, regs, orig_i0,
-                                   cookie.restart_syscall);
+                extern void do_signal32(sigset_t *, struct pt_regs *,
+                                        unsigned long, int);
+                do_signal32(oldset, regs, orig_i0,
+                            cookie.restart_syscall);
+                return;
         }
 #endif  
 
@@ -635,7 +550,15 @@ static int do_signal(sigset_t *oldset, struct pt_regs * regs,
                 if (cookie.restart_syscall)
                         syscall_restart(orig_i0, regs, &ka.sa);
                 handle_signal(signr, &ka, &info, oldset, regs);
-                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 ||
@@ -652,15 +575,21 @@ static int do_signal(sigset_t *oldset, struct pt_regs * regs,
                 regs->tpc -= 4;
                 regs->tnpc -= 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);
+        }
 }
 
-void do_notify_resume(sigset_t *oldset, struct pt_regs *regs,
-                      unsigned long orig_i0, int restart_syscall,
+void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0, int restart_syscall,
                       unsigned long thread_info_flags)
 {
-        if (thread_info_flags & _TIF_SIGPENDING)
-                do_signal(oldset, regs, orig_i0, restart_syscall);
+        if (thread_info_flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK))
+                do_signal(regs, orig_i0, restart_syscall);
 }
 
 void ptrace_signal_deliver(struct pt_regs *regs, void *cookie)