initial_commit

1 files changed, 210 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
new file mode 100644
index 00000000..2300426e
--- /dev/null
+++ b/arch/powerpc/kernel/signal.c
@@ -0,0 +1,210 @@
+/*
+ * Common signal handling code for both 32 and 64 bits
+ *
+ *    Copyright (c) 2007 Benjamin Herrenschmidt, IBM Coproration
+ *    Extracted from signal_32.c and signal_64.c
+ *
+ * This file is subject to the terms and conditions of the GNU General
+ * Public License.  See the file README.legal in the main directory of
+ * this archive for more details.
+ */
+
+#include <linux/tracehook.h>
+#include <linux/signal.h>
+#include <asm/hw_breakpoint.h>
+#include <asm/uaccess.h>
+#include <asm/unistd.h>
+
+#include "signal.h"
+
+/* Log an error when sending an unhandled signal to a process. Controlled
+ * through debug.exception-trace sysctl.
+ */
+
+int show_unhandled_signals = 0;
+
+/*
+ * Allocate space for the signal frame
+ */
+void __user * get_sigframe(struct k_sigaction *ka, struct pt_regs *regs,
+			   size_t frame_size, int is_32)
+{
+        unsigned long oldsp, newsp;
+
+        /* Default to using normal stack */
+        oldsp = get_clean_sp(regs, is_32);
+
+	/* Check for alt stack */
+	if ((ka->sa.sa_flags & SA_ONSTACK) &&
+	    current->sas_ss_size && !on_sig_stack(oldsp))
+		oldsp = (current->sas_ss_sp + current->sas_ss_size);
+
+	/* Get aligned frame */
+	newsp = (oldsp - frame_size) & ~0xFUL;
+
+	/* Check access */
+	if (!access_ok(VERIFY_WRITE, (void __user *)newsp, oldsp - newsp))
+		return NULL;
+
+        return (void __user *)newsp;
+}
+
+
+/*
+ * Restore the user process's signal mask
+ */
+void restore_sigmask(sigset_t *set)
+{
+	sigdelsetmask(set, ~_BLOCKABLE);
+	spin_lock_irq(&current->sighand->siglock);
+	current->blocked = *set;
+	recalc_sigpending();
+	spin_unlock_irq(&current->sighand->siglock);
+}
+
+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;
+
+	/* syscall ? */
+	if (TRAP(regs) != 0x0C00)
+		return;
+
+	/* error signalled ? */
+	if (!(regs->ccr & 0x10000000))
+		return;
+
+	switch (ret) {
+	case ERESTART_RESTARTBLOCK:
+	case ERESTARTNOHAND:
+		/* ERESTARTNOHAND means that the syscall should only be
+		 * restarted if there was no handler for the signal, and since
+		 * we only get here if there is a handler, we dont restart.
+		 */
+		restart = !has_handler;
+		break;
+	case ERESTARTSYS:
+		/* ERESTARTSYS means to restart the syscall if there is no
+		 * handler or the handler was registered with SA_RESTART
+		 */
+		restart = !has_handler || (ka->sa.sa_flags & SA_RESTART) != 0;
+		break;
+	case ERESTARTNOINTR:
+		/* ERESTARTNOINTR means that the syscall should be
+		 * called again after the signal handler returns.
+		 */
+		break;
+	default:
+		return;
+	}
+	if (restart) {
+		if (ret == ERESTART_RESTARTBLOCK)
+			regs->gpr[0] = __NR_restart_syscall;
+		else
+			regs->gpr[3] = regs->orig_gpr3;
+		regs->nip -= 4;
+		regs->result = 0;
+	} else {
+		regs->result = -EINTR;
+		regs->gpr[3] = EINTR;
+		regs->ccr |= 0x10000000;
+	}
+}
+
+static int do_signal_pending(sigset_t *oldset, struct pt_regs *regs)
+{
+	siginfo_t info;
+	int signr;
+	struct k_sigaction ka;
+	int ret;
+	int is32 = is_32bit_task();
+
+	if (current_thread_info()->local_flags & _TLF_RESTORE_SIGMASK)
+		oldset = &current->saved_sigmask;
+	else if (!oldset)
+		oldset = &current->blocked;
+
+	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
+
+	/* Is there any syscall restart business here ? */
+	check_syscall_restart(regs, &ka, signr > 0);
+
+	if (signr <= 0) {
+		struct thread_info *ti = current_thread_info();
+		/* No signal to deliver -- put the saved sigmask back */
+		if (ti->local_flags & _TLF_RESTORE_SIGMASK) {
+			ti->local_flags &= ~_TLF_RESTORE_SIGMASK;
+			sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
+		}
+		regs->trap = 0;
+		return 0;               /* no signals delivered */
+	}
+
+#ifndef CONFIG_PPC_ADV_DEBUG_REGS
+        /*
+	 * 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
+	/* Re-enable the breakpoints for the signal stack */
+	thread_change_pc(current, regs);
+
+	if (is32) {
+        	if (ka.sa.sa_flags & SA_SIGINFO)
+			ret = handle_rt_signal32(signr, &ka, &info, oldset,
+					regs);
+		else
+			ret = handle_signal32(signr, &ka, &info, oldset,
+					regs);
+	} else {
+		ret = handle_rt_signal64(signr, &ka, &info, oldset, regs);
+	}
+
+	regs->trap = 0;
+	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 TLF_RESTORE_SIGMASK flag.
+		 */
+		current_thread_info()->local_flags &= ~_TLF_RESTORE_SIGMASK;
+
+		/*
+		 * Let tracing know that we've done the handler setup.
+		 */
+		tracehook_signal_handler(signr, &info, &ka, regs,
+					 test_thread_flag(TIF_SINGLESTEP));
+	}
+
+	return ret;
+}
+
+void do_signal(struct pt_regs *regs, unsigned long thread_info_flags)
+{
+	if (thread_info_flags & _TIF_SIGPENDING)
+		do_signal_pending(NULL, regs);
+
+	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
+		clear_thread_flag(TIF_NOTIFY_RESUME);
+		tracehook_notify_resume(regs);
+	}
+}
+
+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)
+{
+	return do_sigaltstack(uss, uoss, regs->gpr[1]);
+}