CRIS v32: Update signal handling in kernel/signal.c

- do_signal now returns void, and does not have the previous signal set
  as a parameter.
- Remove sys_rt_sigsuspend, we can use the common one instead.
- Change sys_sigsuspend to be more like x86, don't call do_signal here.
- handle_signal, setup_frame and setup_rt_frame now return -EFAULT
  if we've delivered a segfault, which is used by callers to perform
  necessary cleanup.
- Break long lines, correct whitespace and formatting errors.

diff --git a/arch/cris/arch-v32/kernel/signal.c b/arch/cris/arch-v32/kernel/signal.c
index 024cc690197450a27f563915c5fc4bcfa98927cc..58c1866804e31974fdef993c44d7a34cb2f37aae 100644 (file)
--- a/arch/cris/arch-v32/kernel/signal.c
+++ b/arch/cris/arch-v32/kernel/signal.c
@@ -50,7 +50,7 @@ struct rt_signal_frame {
        unsigned char retcode[8];       /* Trampoline code. */
 };
 
-int do_signal(int restart, sigset_t *oldset, struct pt_regs *regs);
+void do_signal(int restart, struct pt_regs *regs);
 void keep_debug_flags(unsigned long oldccs, unsigned long oldspc,
                      struct pt_regs *regs);
 /*
@@ -61,74 +61,16 @@ int
 sys_sigsuspend(old_sigset_t mask, long r11, long r12, long r13, long mof,
               long srp, struct pt_regs *regs)
 {
-       sigset_t saveset;
-
        mask &= _BLOCKABLE;
-
        spin_lock_irq(&current->sighand->siglock);
-
-       saveset = current->blocked;
-
+       current->saved_sigmask = current->blocked;
        siginitset(&current->blocked, mask);
-
-       recalc_sigpending();
-       spin_unlock_irq(&current->sighand->siglock);
-
-       regs->r10 = -EINTR;
-
-       while (1) {
-               current->state = TASK_INTERRUPTIBLE;
-               schedule();
-
-               if (do_signal(0, &saveset, regs)) {
-                       /*
-                        * This point is reached twice: once to call
-                        * the signal handler, then again to return
-                        * from the sigsuspend system call. When
-                        * calling the signal handler, R10 hold the
-                        * signal number as set by do_signal(). The
-                        * sigsuspend  call will always return with
-                        * the restored value above; -EINTR.
-                        */
-                       return regs->r10;
-               }
-       }
-}
-
-/* Define some dummy arguments to be able to reach the regs argument. */
-int
-sys_rt_sigsuspend(sigset_t *unewset, size_t sigsetsize, long r12, long r13,
-                 long mof, long srp, struct pt_regs *regs)
-{
-       sigset_t saveset;
-       sigset_t newset;
-
-       if (sigsetsize != sizeof(sigset_t))
-               return -EINVAL;
-
-       if (copy_from_user(&newset, unewset, sizeof(newset)))
-               return -EFAULT;
-
-       sigdelsetmask(&newset, ~_BLOCKABLE);
-       spin_lock_irq(&current->sighand->siglock);
-
-       saveset = current->blocked;
-       current->blocked = newset;
-
        recalc_sigpending();
        spin_unlock_irq(&current->sighand->siglock);
-
-       regs->r10 = -EINTR;
-
-       while (1) {
-               current->state = TASK_INTERRUPTIBLE;
-               schedule();
-
-               if (do_signal(0, &saveset, regs)) {
-                       /* See comment in function above. */
-                       return regs->r10;
-               }
-       }
+       current->state = TASK_INTERRUPTIBLE;
+       schedule();
+       set_thread_flag(TIF_RESTORE_SIGMASK);
+       return -ERESTARTNOHAND;
 }
 
 int
@@ -290,7 +232,7 @@ sys_rt_sigreturn(long r10, long r11, long r12, long r13, long mof, long srp,
                goto badframe;
 
        if (do_sigaltstack(&frame->uc.uc_stack, NULL, rdusp()) == -EFAULT)
-               goto badframe;
+               goto badframe;
 
        keep_debug_flags(oldccs, oldspc, regs);
 
@@ -347,11 +289,11 @@ get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size)
 /* Grab and setup a signal frame.
  *
  * Basically a lot of state-info is stacked, and arranged for the
- * user-mode program to return to the kernel using either a trampoline
+ * user-mode program to return to the kernel using either a trampiline
  * which performs the syscall sigreturn(), or a provided user-mode
  * trampoline.
   */
-static void
+static int
 setup_frame(int sig, struct k_sigaction *ka,  sigset_t *set,
            struct pt_regs * regs)
 {
@@ -417,16 +359,17 @@ setup_frame(int sig, struct k_sigaction *ka,  sigset_t *set,
        /* Actually move the USP to reflect the stacked frame. */
        wrusp((unsigned long)frame);
 
-       return;
+       return 0;
 
 give_sigsegv:
        if (sig == SIGSEGV)
                ka->sa.sa_handler = SIG_DFL;
 
        force_sig(SIGSEGV, 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)
 {
@@ -503,21 +446,24 @@ setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
        /* Actually move the usp to reflect the stacked frame. */
        wrusp((unsigned long)frame);
 
-       return;
+       return 0;
 
 give_sigsegv:
        if (sig == SIGSEGV)
                ka->sa.sa_handler = SIG_DFL;
 
        force_sig(SIGSEGV, current);
+       return -EFAULT;
 }
 
 /* Invoke a singal handler to, well, handle the signal. */
-static inline void
+static inline int
 handle_signal(int canrestart, unsigned long sig,
              siginfo_t *info, struct k_sigaction *ka,
               sigset_t *oldset, struct pt_regs * regs)
 {
+       int ret;
+
        /* Check if this got called from a system call. */
        if (canrestart) {
                /* If so, check system call restarting. */
@@ -561,19 +507,24 @@ handle_signal(int canrestart, unsigned long sig,
 
        /* 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_frame(sig, ka, oldset, regs);
+               ret = setup_frame(sig, ka, oldset, regs);
 
        if (ka->sa.sa_flags & SA_ONESHOT)
                ka->sa.sa_handler = SIG_DFL;
 
-       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);
+       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);
+       }
+
+       return ret;
 }
 
 /*
@@ -587,12 +538,13 @@ handle_signal(int canrestart, unsigned long sig,
  * we can use user_mode(regs) to see if we came directly from kernel or user
  * mode below.
  */
-int
-do_signal(int canrestart, sigset_t *oldset, struct pt_regs *regs)
+void
+do_signal(int canrestart, struct pt_regs *regs)
 {
        int signr;
        siginfo_t info;
         struct k_sigaction ka;
+       sigset_t *oldset;
 
        /*
         * The common case should go fast, which is why this point is
@@ -600,17 +552,28 @@ do_signal(int canrestart, sigset_t *oldset, struct pt_regs *regs)
         * without doing anything.
         */
        if (!user_mode(regs))
-               return 1;
+               return;
 
-       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, NULL);
 
        if (signr > 0) {
-               /* Deliver the signal. */
-               handle_signal(canrestart, signr, &info, &ka, oldset, regs);
-               return 1;
+               /* Whee!  Actually deliver the signal.  */
+               if (handle_signal(canrestart, signr, &info, &ka,
+                               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 TIF_RESTORE_SIGMASK flag */
+                       if (test_thread_flag(TIF_RESTORE_SIGMASK))
+                               clear_thread_flag(TIF_RESTORE_SIGMASK);
+               }
+
+               return;
        }
 
        /* Got here from a system call? */
@@ -628,7 +591,12 @@ do_signal(int canrestart, sigset_t *oldset, struct pt_regs *regs)
                }
        }
 
-       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 void
@@ -641,7 +609,7 @@ ugdb_trap_user(struct thread_info *ti, int sig)
                user_regs(ti)->spc = 0;
        }
        /* FIXME: Filter out false h/w breakpoint hits (i.e. EDA
-          not within any configured h/w breakpoint range). Synchronize with
+          not withing any configured h/w breakpoint range). Synchronize with
           what already exists for kernel debugging.  */
        if (((user_regs(ti)->exs & 0xff00) >> 8) == BREAK_8_INTR_VECT) {
                /* Break 8: subtract 2 from ERP unless in a delay slot. */