Initial import

1 files changed, 431 insertions, 0 deletions

diff --git a/arch/mn10300/kernel/signal.c b/arch/mn10300/kernel/signal.c
new file mode 100644
index 000000000..dfd0301cf
--- /dev/null
+++ b/arch/mn10300/kernel/signal.c
@@ -0,0 +1,431 @@
+/* MN10300 Signal handling
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/kernel.h>
+#include <linux/signal.h>
+#include <linux/errno.h>
+#include <linux/wait.h>
+#include <linux/ptrace.h>
+#include <linux/unistd.h>
+#include <linux/stddef.h>
+#include <linux/tty.h>
+#include <linux/personality.h>
+#include <linux/suspend.h>
+#include <linux/tracehook.h>
+#include <asm/cacheflush.h>
+#include <asm/ucontext.h>
+#include <asm/uaccess.h>
+#include <asm/fpu.h>
+#include "sigframe.h"
+
+#define DEBUG_SIG 0
+
+/*
+ * do a signal return; undo the signal stack.
+ */
+static int restore_sigcontext(struct pt_regs *regs,
+			      struct sigcontext __user *sc, long *_d0)
+{
+	unsigned int err = 0;
+
+	/* Always make any pending restarted system calls return -EINTR */
+	current->restart_block.fn = do_no_restart_syscall;
+
+	if (is_using_fpu(current))
+		fpu_kill_state(current);
+
+#define COPY(x) err |= __get_user(regs->x, &sc->x)
+	COPY(d1); COPY(d2); COPY(d3);
+	COPY(a0); COPY(a1); COPY(a2); COPY(a3);
+	COPY(e0); COPY(e1); COPY(e2); COPY(e3);
+	COPY(e4); COPY(e5); COPY(e6); COPY(e7);
+	COPY(lar); COPY(lir);
+	COPY(mdr); COPY(mdrq);
+	COPY(mcvf); COPY(mcrl); COPY(mcrh);
+	COPY(sp); COPY(pc);
+#undef COPY
+
+	{
+		unsigned int tmpflags;
+#ifndef CONFIG_MN10300_USING_JTAG
+#define USER_EPSW (EPSW_FLAG_Z | EPSW_FLAG_N | EPSW_FLAG_C | EPSW_FLAG_V | \
+		   EPSW_T | EPSW_nAR)
+#else
+#define USER_EPSW (EPSW_FLAG_Z | EPSW_FLAG_N | EPSW_FLAG_C | EPSW_FLAG_V | \
+		   EPSW_nAR)
+#endif
+		err |= __get_user(tmpflags, &sc->epsw);
+		regs->epsw = (regs->epsw & ~USER_EPSW) |
+		  (tmpflags & USER_EPSW);
+		regs->orig_d0 = -1;		/* disable syscall checks */
+	}
+
+	{
+		struct fpucontext *buf;
+		err |= __get_user(buf, &sc->fpucontext);
+		if (buf) {
+			if (verify_area(VERIFY_READ, buf, sizeof(*buf)))
+				goto badframe;
+			err |= fpu_restore_sigcontext(buf);
+		}
+	}
+
+	err |= __get_user(*_d0, &sc->d0);
+	return err;
+
+badframe:
+	return 1;
+}
+
+/*
+ * standard signal return syscall
+ */
+asmlinkage long sys_sigreturn(void)
+{
+	struct sigframe __user *frame;
+	sigset_t set;
+	long d0;
+
+	frame = (struct sigframe __user *) current_frame()->sp;
+	if (verify_area(VERIFY_READ, frame, sizeof(*frame)))
+		goto badframe;
+	if (__get_user(set.sig[0], &frame->sc.oldmask))
+		goto badframe;
+
+	if (_NSIG_WORDS > 1 &&
+	    __copy_from_user(&set.sig[1], &frame->extramask,
+			     sizeof(frame->extramask)))
+		goto badframe;
+
+	set_current_blocked(&set);
+
+	if (restore_sigcontext(current_frame(), &frame->sc, &d0))
+		goto badframe;
+
+	return d0;
+
+badframe:
+	force_sig(SIGSEGV, current);
+	return 0;
+}
+
+/*
+ * realtime signal return syscall
+ */
+asmlinkage long sys_rt_sigreturn(void)
+{
+	struct rt_sigframe __user *frame;
+	sigset_t set;
+	long d0;
+
+	frame = (struct rt_sigframe __user *) current_frame()->sp;
+	if (verify_area(VERIFY_READ, frame, sizeof(*frame)))
+		goto badframe;
+	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
+		goto badframe;
+
+	set_current_blocked(&set);
+
+	if (restore_sigcontext(current_frame(), &frame->uc.uc_mcontext, &d0))
+		goto badframe;
+
+	if (restore_altstack(&frame->uc.uc_stack))
+		goto badframe;
+
+	return d0;
+
+badframe:
+	force_sig(SIGSEGV, current);
+	return 0;
+}
+
+/*
+ * store the userspace context into a signal frame
+ */
+static int setup_sigcontext(struct sigcontext __user *sc,
+			    struct fpucontext *fpuctx,
+			    struct pt_regs *regs,
+			    unsigned long mask)
+{
+	int tmp, err = 0;
+
+#define COPY(x) err |= __put_user(regs->x, &sc->x)
+	COPY(d0); COPY(d1); COPY(d2); COPY(d3);
+	COPY(a0); COPY(a1); COPY(a2); COPY(a3);
+	COPY(e0); COPY(e1); COPY(e2); COPY(e3);
+	COPY(e4); COPY(e5); COPY(e6); COPY(e7);
+	COPY(lar); COPY(lir);
+	COPY(mdr); COPY(mdrq);
+	COPY(mcvf); COPY(mcrl); COPY(mcrh);
+	COPY(sp); COPY(epsw); COPY(pc);
+#undef COPY
+
+	tmp = fpu_setup_sigcontext(fpuctx);
+	if (tmp < 0)
+		err = 1;
+	else
+		err |= __put_user(tmp ? fpuctx : NULL, &sc->fpucontext);
+
+	/* non-iBCS2 extensions.. */
+	err |= __put_user(mask, &sc->oldmask);
+
+	return err;
+}
+
+/*
+ * determine which stack to use..
+ */
+static inline void __user *get_sigframe(struct ksignal *ksig,
+					struct pt_regs *regs,
+					size_t frame_size)
+{
+	unsigned long sp = sigsp(regs->sp, ksig);
+
+	return (void __user *) ((sp - frame_size) & ~7UL);
+}
+
+/*
+ * set up a normal signal frame
+ */
+static int setup_frame(struct ksignal *ksig, sigset_t *set,
+		       struct pt_regs *regs)
+{
+	struct sigframe __user *frame;
+	int sig = ksig->sig;
+
+	frame = get_sigframe(ksig, regs, sizeof(*frame));
+
+	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
+		return -EFAULT;
+
+	if (__put_user(sig, &frame->sig) < 0 ||
+	    __put_user(&frame->sc, &frame->psc) < 0)
+		return -EFAULT;
+
+	if (setup_sigcontext(&frame->sc, &frame->fpuctx, regs, set->sig[0]))
+		return -EFAULT;
+
+	if (_NSIG_WORDS > 1) {
+		if (__copy_to_user(frame->extramask, &set->sig[1],
+				   sizeof(frame->extramask)))
+			return -EFAULT;
+	}
+
+	/* set up to return from userspace.  If provided, use a stub already in
+	 * userspace */
+	if (ksig->ka.sa.sa_flags & SA_RESTORER) {
+		if (__put_user(ksig->ka.sa.sa_restorer, &frame->pretcode))
+			return -EFAULT;
+	} else {
+		if (__put_user((void (*)(void))frame->retcode,
+			       &frame->pretcode))
+			return -EFAULT;
+		/* this is mov $,d0; syscall 0 */
+		if (__put_user(0x2c, (char *)(frame->retcode + 0)) ||
+		    __put_user(__NR_sigreturn, (char *)(frame->retcode + 1)) ||
+		    __put_user(0x00, (char *)(frame->retcode + 2)) ||
+		    __put_user(0xf0, (char *)(frame->retcode + 3)) ||
+		    __put_user(0xe0, (char *)(frame->retcode + 4)))
+			return -EFAULT;
+		flush_icache_range((unsigned long) frame->retcode,
+				   (unsigned long) frame->retcode + 5);
+	}
+
+	/* set up registers for signal handler */
+	regs->sp = (unsigned long) frame;
+	regs->pc = (unsigned long) ksig->ka.sa.sa_handler;
+	regs->d0 = sig;
+	regs->d1 = (unsigned long) &frame->sc;
+
+#if DEBUG_SIG
+	printk(KERN_DEBUG "SIG deliver %d (%s:%d): sp=%p pc=%lx ra=%p\n",
+	       sig, current->comm, current->pid, frame, regs->pc,
+	       frame->pretcode);
+#endif
+
+	return 0;
+}
+
+/*
+ * set up a realtime signal frame
+ */
+static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
+			  struct pt_regs *regs)
+{
+	struct rt_sigframe __user *frame;
+	int sig = ksig->sig;
+
+	frame = get_sigframe(ksig, regs, sizeof(*frame));
+
+	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
+		return -EFAULT;
+
+	if (__put_user(sig, &frame->sig) ||
+	    __put_user(&frame->info, &frame->pinfo) ||
+	    __put_user(&frame->uc, &frame->puc) ||
+	    copy_siginfo_to_user(&frame->info, &ksig->info))
+		return -EFAULT;
+
+	/* create the ucontext.  */
+	if (__put_user(0, &frame->uc.uc_flags) ||
+	    __put_user(0, &frame->uc.uc_link) ||
+	    __save_altstack(&frame->uc.uc_stack, regs->sp) ||
+	    setup_sigcontext(&frame->uc.uc_mcontext,
+			     &frame->fpuctx, regs, set->sig[0]) ||
+	    __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)))
+		return -EFAULT;
+
+	/* set up to return from userspace.  If provided, use a stub already in
+	 * userspace */
+	if (ksig->ka.sa.sa_flags & SA_RESTORER) {
+		if (__put_user(ksig->ka.sa.sa_restorer, &frame->pretcode))
+			return -EFAULT;
+
+	} else {
+		if (__put_user((void(*)(void))frame->retcode,
+			       &frame->pretcode) ||
+		    /* This is mov $,d0; syscall 0 */
+		    __put_user(0x2c, (char *)(frame->retcode + 0)) ||
+		    __put_user(__NR_rt_sigreturn,
+			       (char *)(frame->retcode + 1)) ||
+		    __put_user(0x00, (char *)(frame->retcode + 2)) ||
+		    __put_user(0xf0, (char *)(frame->retcode + 3)) ||
+		    __put_user(0xe0, (char *)(frame->retcode + 4)))
+			return -EFAULT;
+
+		flush_icache_range((u_long) frame->retcode,
+				   (u_long) frame->retcode + 5);
+	}
+
+	/* Set up registers for signal handler */
+	regs->sp = (unsigned long) frame;
+	regs->pc = (unsigned long) ksig->ka.sa.sa_handler;
+	regs->d0 = sig;
+	regs->d1 = (long) &frame->info;
+
+#if DEBUG_SIG
+	printk(KERN_DEBUG "SIG deliver %d (%s:%d): sp=%p pc=%lx ra=%p\n",
+	       sig, current->comm, current->pid, frame, regs->pc,
+	       frame->pretcode);
+#endif
+
+	return 0;
+}
+
+static inline void stepback(struct pt_regs *regs)
+{
+	regs->pc -= 2;
+	regs->orig_d0 = -1;
+}
+
+/*
+ * handle the actual delivery of a signal to userspace
+ */
+static int handle_signal(struct ksignal *ksig, struct pt_regs *regs)
+{
+	sigset_t *oldset = sigmask_to_save();
+	int ret;
+
+	/* Are we from a system call? */
+	if (regs->orig_d0 >= 0) {
+		/* If so, check system call restarting.. */
+		switch (regs->d0) {
+		case -ERESTART_RESTARTBLOCK:
+		case -ERESTARTNOHAND:
+			regs->d0 = -EINTR;
+			break;
+
+		case -ERESTARTSYS:
+			if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
+				regs->d0 = -EINTR;
+				break;
+			}
+
+			/* fallthrough */
+		case -ERESTARTNOINTR:
+			regs->d0 = regs->orig_d0;
+			stepback(regs);
+		}
+	}
+
+	/* Set up the stack frame */
+	if (ksig->ka.sa.sa_flags & SA_SIGINFO)
+		ret = setup_rt_frame(ksig, oldset, regs);
+	else
+		ret = setup_frame(ksig, oldset, regs);
+
+	signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP));
+	return 0;
+}
+
+/*
+ * handle a potential signal
+ */
+static void do_signal(struct pt_regs *regs)
+{
+	struct ksignal ksig;
+
+	if (get_signal(&ksig)) {
+		handle_signal(&ksig, regs);
+		return;
+	}
+
+	/* did we come from a system call? */
+	if (regs->orig_d0 >= 0) {
+		/* restart the system call - no handlers present */
+		switch (regs->d0) {
+		case -ERESTARTNOHAND:
+		case -ERESTARTSYS:
+		case -ERESTARTNOINTR:
+			regs->d0 = regs->orig_d0;
+			stepback(regs);
+			break;
+
+		case -ERESTART_RESTARTBLOCK:
+			regs->d0 = __NR_restart_syscall;
+			stepback(regs);
+			break;
+		}
+	}
+
+	/* if there's no signal to deliver, we just put the saved sigmask
+	 * back */
+	restore_saved_sigmask();
+}
+
+/*
+ * notification of userspace execution resumption
+ * - triggered by current->work.notify_resume
+ */
+asmlinkage void do_notify_resume(struct pt_regs *regs, u32 thread_info_flags)
+{
+	/* Pending single-step? */
+	if (thread_info_flags & _TIF_SINGLESTEP) {
+#ifndef CONFIG_MN10300_USING_JTAG
+		regs->epsw |= EPSW_T;
+		clear_thread_flag(TIF_SINGLESTEP);
+#else
+		BUG(); /* no h/w single-step if using JTAG unit */
+#endif
+	}
+
+	/* deal with pending signal delivery */
+	if (thread_info_flags & _TIF_SIGPENDING)
+		do_signal(regs);
+
+	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
+		clear_thread_flag(TIF_NOTIFY_RESUME);
+		tracehook_notify_resume(current_frame());
+	}
+}