[POWERPC] Consolidate do_signal

do_signal has exactly the same behaviour on 32bit and 64bit and 32bit
compat on 64bit for handling 32bit signals.  Consolidate all these
into one common function in signal.c.  The only odd left over is
the try_to_free in the 32bit version that no other architecture has
in mainline (only in i386 for some odd SuSE release).  We should
probably get rid of it in a separate patch.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 105 insertions, 2 deletions

diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
index f92856b98b70..640b5f3611ee 100644
--- a/arch/powerpc/kernel/signal.c
+++ b/arch/powerpc/kernel/signal.c
@@ -9,6 +9,7 @@
  * this archive for more details.
  */
 
+#include <linux/freezer.h>
 #include <linux/ptrace.h>
 #include <linux/signal.h>
 #include <asm/unistd.h>
@@ -16,6 +17,19 @@
 #include "signal.h"
 
 
+#ifdef CONFIG_PPC64
+static inline int is_32bit_task(void)
+{
+        return test_thread_flag(TIF_32BIT);
+}
+#else
+static inline int is_32bit_task(void)
+{
+        return 1;
+}
+#endif
+
+
 /*
  * Restore the user process's signal mask
  */
@@ -28,8 +42,8 @@ void restore_sigmask(sigset_t *set)
         spin_unlock_irq(&current->sighand->siglock);
 }
 
-void check_syscall_restart(struct pt_regs *regs, struct k_sigaction *ka,
-                           int has_handler)
+static void check_syscall_restart(struct pt_regs *regs, struct k_sigaction *ka,
+                                  int has_handler)
 {
         unsigned long ret = regs->gpr[3];
         int restart = 1;
@@ -79,6 +93,95 @@ void check_syscall_restart(struct pt_regs *regs, struct k_sigaction *ka,
         }
 }
 
+int do_signal(sigset_t *oldset, struct pt_regs *regs)
+{
+        siginfo_t info;
+        int signr;
+        struct k_sigaction ka;
+        int ret;
+        int is32 = is_32bit_task();
+
+#ifdef CONFIG_PPC32
+        if (try_to_freeze()) {
+                signr = 0;
+                if (!signal_pending(current))
+                        goto no_signal;
+        }
+#endif
+
+        if (test_thread_flag(TIF_RESTORE_SIGMASK))
+                oldset = &current->saved_sigmask;
+        else if (!oldset)
+                oldset = &current->blocked;
+
+        signr = get_signal_to_deliver(&info, &ka, regs, NULL);
+
+#ifdef CONFIG_PPC32
+no_signal:
+#endif
+        /* Is there any syscall restart business here ? */
+        check_syscall_restart(regs, &ka, signr > 0);
+
+        if (signr <= 0) {
+                /* No signal to deliver -- 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);
+                }
+                return 0;               /* no signals delivered */
+        }
+
+#ifdef CONFIG_PPC64
+        /*
+         * Reenable the DABR before delivering the signal to
+         * user space. The DABR will have been cleared if it
+         * triggered inside the kernel.
+         */
+        if (current->thread.dabr)
+                set_dabr(current->thread.dabr);
+#endif
+
+        if (is32) {
+                unsigned int newsp;
+
+                if ((ka.sa.sa_flags & SA_ONSTACK) &&
+                    current->sas_ss_size && !on_sig_stack(regs->gpr[1]))
+                        newsp = current->sas_ss_sp + current->sas_ss_size;
+                else
+                        newsp = regs->gpr[1];
+
+                if (ka.sa.sa_flags & SA_SIGINFO)
+                        ret = handle_rt_signal32(signr, &ka, &info, oldset,
+                                        regs, newsp);
+                else
+                        ret = handle_signal32(signr, &ka, &info, oldset,
+                                        regs, newsp);
+#ifdef CONFIG_PPC64
+        } else {
+                ret = handle_rt_signal64(signr, &ka, &info, oldset, regs);
+#endif
+        }
+
+        if (ret) {
+                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, signr);
+                recalc_sigpending();
+                spin_unlock_irq(&current->sighand->siglock);
+
+                /*
+                 * A signal was successfully delivered; the saved sigmask is in
+                 * its frame, and we can clear the TIF_RESTORE_SIGMASK flag.
+                 */
+                if (test_thread_flag(TIF_RESTORE_SIGMASK))
+                        clear_thread_flag(TIF_RESTORE_SIGMASK);
+        }
+
+        return ret;
+}
+
 long sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
                 unsigned long r5, unsigned long r6, unsigned long r7,
                 unsigned long r8, struct pt_regs *regs)