Merge branch 'for-2.6.40' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu

[pandora-kernel.git] / arch / arm / kernel / signal.c

diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c
index cb83983..0340224 100644 (file)
--- a/arch/arm/kernel/signal.c
+++ b/arch/arm/kernel/signal.c
@@ -597,45 +597,19 @@ setup_rt_frame(int usig, struct k_sigaction *ka, siginfo_t *info,
        return err;
 }
 
-static inline void setup_syscall_restart(struct pt_regs *regs)
-{
-       regs->ARM_r0 = regs->ARM_ORIG_r0;
-       regs->ARM_pc -= thumb_mode(regs) ? 2 : 4;
-}
-
 /*
  * OK, we're invoking a handler
  */    
 static int
 handle_signal(unsigned long sig, struct k_sigaction *ka,
              siginfo_t *info, sigset_t *oldset,
-             struct pt_regs * regs, int syscall)
+             struct pt_regs * regs)
 {
        struct thread_info *thread = current_thread_info();
        struct task_struct *tsk = current;
        int usig = sig;
        int ret;
 
-       /*
-        * If we were from a system call, check for system call restarting...
-        */
-       if (syscall) {
-               switch (regs->ARM_r0) {
-               case -ERESTART_RESTARTBLOCK:
-               case -ERESTARTNOHAND:
-                       regs->ARM_r0 = -EINTR;
-                       break;
-               case -ERESTARTSYS:
-                       if (!(ka->sa.sa_flags & SA_RESTART)) {
-                               regs->ARM_r0 = -EINTR;
-                               break;
-                       }
-                       /* fallthrough */
-               case -ERESTARTNOINTR:
-                       setup_syscall_restart(regs);
-               }
-       }
-
        /*
         * translate the signal
         */
@@ -685,6 +659,7 @@ handle_signal(unsigned long sig, struct k_sigaction *ka,
  */
 static void do_signal(struct pt_regs *regs, int syscall)
 {
+       unsigned int retval = 0, continue_addr = 0, restart_addr = 0;
        struct k_sigaction ka;
        siginfo_t info;
        int signr;
@@ -698,18 +673,61 @@ static void do_signal(struct pt_regs *regs, int syscall)
        if (!user_mode(regs))
                return;
 
+       /*
+        * If we were from a system call, check for system call restarting...
+        */
+       if (syscall) {
+               continue_addr = regs->ARM_pc;
+               restart_addr = continue_addr - (thumb_mode(regs) ? 2 : 4);
+               retval = regs->ARM_r0;
+
+               /*
+                * Prepare for system call restart.  We do this here so that a
+                * debugger will see the already changed PSW.
+                */
+               switch (retval) {
+               case -ERESTARTNOHAND:
+               case -ERESTARTSYS:
+               case -ERESTARTNOINTR:
+                       regs->ARM_r0 = regs->ARM_ORIG_r0;
+                       regs->ARM_pc = restart_addr;
+                       break;
+               case -ERESTART_RESTARTBLOCK:
+                       regs->ARM_r0 = -EINTR;
+                       break;
+               }
+       }
+
        if (try_to_freeze())
                goto no_signal;
 
+       /*
+        * Get the signal to deliver.  When running under ptrace, at this
+        * point the debugger may change all our registers ...
+        */
        signr = get_signal_to_deliver(&info, &ka, regs, NULL);
        if (signr > 0) {
                sigset_t *oldset;
 
+               /*
+                * Depending on the signal settings we may need to revert the
+                * decision to restart the system call.  But skip this if a
+                * debugger has chosen to restart at a different PC.
+                */
+               if (regs->ARM_pc == restart_addr) {
+                       if (retval == -ERESTARTNOHAND
+                           || (retval == -ERESTARTSYS
+                               && !(ka.sa.sa_flags & SA_RESTART))) {
+                               regs->ARM_r0 = -EINTR;
+                               regs->ARM_pc = continue_addr;
+                       }
+               }
+
                if (test_thread_flag(TIF_RESTORE_SIGMASK))
                        oldset = &current->saved_sigmask;
                else
                        oldset = &current->blocked;
-               if (handle_signal(signr, &ka, &info, oldset, regs, syscall) == 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,
@@ -723,11 +741,14 @@ static void do_signal(struct pt_regs *regs, int syscall)
        }
 
  no_signal:
-       /*
-        * No signal to deliver to the process - restart the syscall.
-        */
        if (syscall) {
-               if (regs->ARM_r0 == -ERESTART_RESTARTBLOCK) {
+               /*
+                * Handle restarting a different system call.  As above,
+                * if a debugger has chosen to restart at a different PC,
+                * ignore the restart.
+                */
+               if (retval == -ERESTART_RESTARTBLOCK
+                   && regs->ARM_pc == continue_addr) {
                        if (thumb_mode(regs)) {
                                regs->ARM_r7 = __NR_restart_syscall - __NR_SYSCALL_BASE;
                                regs->ARM_pc -= 2;
@@ -750,11 +771,6 @@ static void do_signal(struct pt_regs *regs, int syscall)
 #endif
                        }
                }
-               if (regs->ARM_r0 == -ERESTARTNOHAND ||
-                   regs->ARM_r0 == -ERESTARTSYS ||
-                   regs->ARM_r0 == -ERESTARTNOINTR) {
-                       setup_syscall_restart(regs);
-               }
 
                /* If there's no signal to deliver, we just put the saved sigmask
                 * back.