m68k: merge the MMU and non-MMU signal.c code

The MMU (signal_mm.c) and non-MMU (signal_no.c) versions of the m68k
architecture signal handling code are very similar. Most of their code is
the same.

Merge the two back into a single signal.c, and move some of the code around
inside the file to minimize the number of #ifdefs required. Specificially
we can group out the CONFIG_FPU and the CONFIG_MMU code. We end up needing
a few other "#ifdef CONFIG_MMU" as well, but not too many.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>

1 files changed, 1199 insertions, 2 deletions

diff --git a/arch/m68k/kernel/signal.c b/arch/m68k/kernel/signal.c
index 2e25713e2ead..1747c7030a33 100644
--- a/arch/m68k/kernel/signal.c
+++ b/arch/m68k/kernel/signal.c
@@ -1,5 +1,1202 @@
+/*
+ *  linux/arch/m68k/kernel/signal.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file COPYING in the main directory of this archive
+ * for more details.
+ */
+
+/*
+ * Linux/m68k support by Hamish Macdonald
+ *
+ * 68060 fixes by Jesper Skov
+ *
+ * 1997-12-01  Modified for POSIX.1b signals by Andreas Schwab
+ *
+ * mathemu support by Roman Zippel
+ *  (Note: fpstate in the signal context is completely ignored for the emulator
+ *         and the internal floating point format is put on stack)
+ */
+
+/*
+ * ++roman (07/09/96): implemented signal stacks (specially for tosemu on
+ * Atari :-) Current limitation: Only one sigstack can be active at one time.
+ * If a second signal with SA_ONSTACK set arrives while working on a sigstack,
+ * SA_ONSTACK is ignored. This behaviour avoids lots of trouble with nested
+ * signal handlers!
+ */
+
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/kernel.h>
+#include <linux/signal.h>
+#include <linux/syscalls.h>
+#include <linux/errno.h>
+#include <linux/wait.h>
+#include <linux/ptrace.h>
+#include <linux/unistd.h>
+#include <linux/stddef.h>
+#include <linux/highuid.h>
+#include <linux/personality.h>
+#include <linux/tty.h>
+#include <linux/binfmts.h>
+#include <linux/module.h>
+
+#include <asm/setup.h>
+#include <asm/uaccess.h>
+#include <asm/pgtable.h>
+#include <asm/traps.h>
+#include <asm/ucontext.h>
+
+#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
+
 #ifdef CONFIG_MMU
-#include "signal_mm.c"
+
+/*
+ * Handle the slight differences in classic 68k and ColdFire trap frames.
+ */
+#ifdef CONFIG_COLDFIRE
+#define	FORMAT		4
+#define	FMT4SIZE	0
 #else
-#include "signal_no.c"
+#define	FORMAT		0
+#define	FMT4SIZE	sizeof(((struct frame *)0)->un.fmt4)
 #endif
+
+static const int frame_size_change[16] = {
+  [1]	= -1, /* sizeof(((struct frame *)0)->un.fmt1), */
+  [2]	= sizeof(((struct frame *)0)->un.fmt2),
+  [3]	= sizeof(((struct frame *)0)->un.fmt3),
+  [4]	= FMT4SIZE,
+  [5]	= -1, /* sizeof(((struct frame *)0)->un.fmt5), */
+  [6]	= -1, /* sizeof(((struct frame *)0)->un.fmt6), */
+  [7]	= sizeof(((struct frame *)0)->un.fmt7),
+  [8]	= -1, /* sizeof(((struct frame *)0)->un.fmt8), */
+  [9]	= sizeof(((struct frame *)0)->un.fmt9),
+  [10]	= sizeof(((struct frame *)0)->un.fmta),
+  [11]	= sizeof(((struct frame *)0)->un.fmtb),
+  [12]	= -1, /* sizeof(((struct frame *)0)->un.fmtc), */
+  [13]	= -1, /* sizeof(((struct frame *)0)->un.fmtd), */
+  [14]	= -1, /* sizeof(((struct frame *)0)->un.fmte), */
+  [15]	= -1, /* sizeof(((struct frame *)0)->un.fmtf), */
+};
+
+static inline int frame_extra_sizes(int f)
+{
+	return frame_size_change[f];
+}
+
+int handle_kernel_fault(struct pt_regs *regs)
+{
+	const struct exception_table_entry *fixup;
+	struct pt_regs *tregs;
+
+	/* Are we prepared to handle this kernel fault? */
+	fixup = search_exception_tables(regs->pc);
+	if (!fixup)
+		return 0;
+
+	/* Create a new four word stack frame, discarding the old one. */
+	regs->stkadj = frame_extra_sizes(regs->format);
+	tregs =	(struct pt_regs *)((long)regs + regs->stkadj);
+	tregs->vector = regs->vector;
+	tregs->format = FORMAT;
+	tregs->pc = fixup->fixup;
+	tregs->sr = regs->sr;
+
+	return 1;
+}
+
+void ptrace_signal_deliver(struct pt_regs *regs, void *cookie)
+{
+	if (regs->orig_d0 < 0)
+		return;
+	switch (regs->d0) {
+	case -ERESTARTNOHAND:
+	case -ERESTARTSYS:
+	case -ERESTARTNOINTR:
+		regs->d0 = regs->orig_d0;
+		regs->orig_d0 = -1;
+		regs->pc -= 2;
+		break;
+	}
+}
+
+static inline void push_cache (unsigned long vaddr)
+{
+	/*
+	 * Using the old cache_push_v() was really a big waste.
+	 *
+	 * What we are trying to do is to flush 8 bytes to ram.
+	 * Flushing 2 cache lines of 16 bytes is much cheaper than
+	 * flushing 1 or 2 pages, as previously done in
+	 * cache_push_v().
+	 *                                                     Jes
+	 */
+	if (CPU_IS_040) {
+		unsigned long temp;
+
+		__asm__ __volatile__ (".chip 68040\n\t"
+				      "nop\n\t"
+				      "ptestr (%1)\n\t"
+				      "movec %%mmusr,%0\n\t"
+				      ".chip 68k"
+				      : "=r" (temp)
+				      : "a" (vaddr));
+
+		temp &= PAGE_MASK;
+		temp |= vaddr & ~PAGE_MASK;
+
+		__asm__ __volatile__ (".chip 68040\n\t"
+				      "nop\n\t"
+				      "cpushl %%bc,(%0)\n\t"
+				      ".chip 68k"
+				      : : "a" (temp));
+	}
+	else if (CPU_IS_060) {
+		unsigned long temp;
+		__asm__ __volatile__ (".chip 68060\n\t"
+				      "plpar (%0)\n\t"
+				      ".chip 68k"
+				      : "=a" (temp)
+				      : "0" (vaddr));
+		__asm__ __volatile__ (".chip 68060\n\t"
+				      "cpushl %%bc,(%0)\n\t"
+				      ".chip 68k"
+				      : : "a" (temp));
+	} else if (!CPU_IS_COLDFIRE) {
+		/*
+		 * 68030/68020 have no writeback cache;
+		 * still need to clear icache.
+		 * Note that vaddr is guaranteed to be long word aligned.
+		 */
+		unsigned long temp;
+		asm volatile ("movec %%cacr,%0" : "=r" (temp));
+		temp += 4;
+		asm volatile ("movec %0,%%caar\n\t"
+			      "movec %1,%%cacr"
+			      : : "r" (vaddr), "r" (temp));
+		asm volatile ("movec %0,%%caar\n\t"
+			      "movec %1,%%cacr"
+			      : : "r" (vaddr + 4), "r" (temp));
+	}
+}
+
+static inline void adjustformat(struct pt_regs *regs)
+{
+}
+
+static inline void save_a5_state(struct sigcontext *sc, struct pt_regs *regs)
+{
+}
+
+#else /* CONFIG_MMU */
+
+void ret_from_user_signal(void);
+void ret_from_user_rt_signal(void);
+
+static inline int frame_extra_sizes(int f)
+{
+	/* No frame size adjustments required on non-MMU CPUs */
+	return 0;
+}
+
+static inline void adjustformat(struct pt_regs *regs)
+{
+	((struct switch_stack *)regs - 1)->a5 = current->mm->start_data;
+	/*
+	 * set format byte to make stack appear modulo 4, which it will
+	 * be when doing the rte
+	 */
+	regs->format = 0x4;
+}
+
+static inline void save_a5_state(struct sigcontext *sc, struct pt_regs *regs)
+{
+	sc->sc_a5 = ((struct switch_stack *)regs - 1)->a5;
+}
+
+static inline void push_cache(unsigned long vaddr)
+{
+}
+
+#endif /* CONFIG_MMU */
+
+/*
+ * Atomically swap in the new signal mask, and wait for a signal.
+ */
+asmlinkage int
+sys_sigsuspend(int unused0, int unused1, old_sigset_t mask)
+{
+	mask &= _BLOCKABLE;
+	spin_lock_irq(&current->sighand->siglock);
+	current->saved_sigmask = current->blocked;
+	siginitset(&current->blocked, mask);
+	recalc_sigpending();
+	spin_unlock_irq(&current->sighand->siglock);
+
+	current->state = TASK_INTERRUPTIBLE;
+	schedule();
+	set_restore_sigmask();
+
+	return -ERESTARTNOHAND;
+}
+
+asmlinkage int
+sys_sigaction(int sig, const struct old_sigaction __user *act,
+	      struct old_sigaction __user *oact)
+{
+	struct k_sigaction new_ka, old_ka;
+	int ret;
+
+	if (act) {
+		old_sigset_t mask;
+		if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
+		    __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
+		    __get_user(new_ka.sa.sa_restorer, &act->sa_restorer) ||
+		    __get_user(new_ka.sa.sa_flags, &act->sa_flags) ||
+		    __get_user(mask, &act->sa_mask))
+			return -EFAULT;
+		siginitset(&new_ka.sa.sa_mask, mask);
+	}
+
+	ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
+
+	if (!ret && oact) {
+		if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
+		    __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
+		    __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer) ||
+		    __put_user(old_ka.sa.sa_flags, &oact->sa_flags) ||
+		    __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask))
+			return -EFAULT;
+	}
+
+	return ret;
+}
+
+asmlinkage int
+sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss)
+{
+	return do_sigaltstack(uss, uoss, rdusp());
+}
+
+
+/*
+ * Do a signal return; undo the signal stack.
+ *
+ * Keep the return code on the stack quadword aligned!
+ * That makes the cache flush below easier.
+ */
+
+struct sigframe
+{
+	char __user *pretcode;
+	int sig;
+	int code;
+	struct sigcontext __user *psc;
+	char retcode[8];
+	unsigned long extramask[_NSIG_WORDS-1];
+	struct sigcontext sc;
+};
+
+struct rt_sigframe
+{
+	char __user *pretcode;
+	int sig;
+	struct siginfo __user *pinfo;
+	void __user *puc;
+	char retcode[8];
+	struct siginfo info;
+	struct ucontext uc;
+};
+
+#define FPCONTEXT_SIZE	216
+#define uc_fpstate	uc_filler[0]
+#define uc_formatvec	uc_filler[FPCONTEXT_SIZE/4]
+#define uc_extra	uc_filler[FPCONTEXT_SIZE/4+1]
+
+#ifdef CONFIG_FPU
+
+static unsigned char fpu_version;	/* version number of fpu, set by setup_frame */
+
+static inline int restore_fpu_state(struct sigcontext *sc)
+{
+	int err = 1;
+
+	if (FPU_IS_EMU) {
+	    /* restore registers */
+	    memcpy(current->thread.fpcntl, sc->sc_fpcntl, 12);
+	    memcpy(current->thread.fp, sc->sc_fpregs, 24);
+	    return 0;
+	}
+
+	if (CPU_IS_060 ? sc->sc_fpstate[2] : sc->sc_fpstate[0]) {
+	    /* Verify the frame format.  */
+	    if (!(CPU_IS_060 || CPU_IS_COLDFIRE) &&
+		 (sc->sc_fpstate[0] != fpu_version))
+		goto out;
+	    if (CPU_IS_020_OR_030) {
+		if (m68k_fputype & FPU_68881 &&
+		    !(sc->sc_fpstate[1] == 0x18 || sc->sc_fpstate[1] == 0xb4))
+		    goto out;
+		if (m68k_fputype & FPU_68882 &&
+		    !(sc->sc_fpstate[1] == 0x38 || sc->sc_fpstate[1] == 0xd4))
+		    goto out;
+	    } else if (CPU_IS_040) {
+		if (!(sc->sc_fpstate[1] == 0x00 ||
+                      sc->sc_fpstate[1] == 0x28 ||
+                      sc->sc_fpstate[1] == 0x60))
+		    goto out;
+	    } else if (CPU_IS_060) {
+		if (!(sc->sc_fpstate[3] == 0x00 ||
+                      sc->sc_fpstate[3] == 0x60 ||
+		      sc->sc_fpstate[3] == 0xe0))
+		    goto out;
+	    } else if (CPU_IS_COLDFIRE) {
+		if (!(sc->sc_fpstate[0] == 0x00 ||
+		      sc->sc_fpstate[0] == 0x05 ||
+		      sc->sc_fpstate[0] == 0xe5))
+		    goto out;
+	    } else
+		goto out;
+
+	    if (CPU_IS_COLDFIRE) {
+		__asm__ volatile ("fmovemd %0,%%fp0-%%fp1\n\t"
+				  "fmovel %1,%%fpcr\n\t"
+				  "fmovel %2,%%fpsr\n\t"
+				  "fmovel %3,%%fpiar"
+				  : /* no outputs */
+				  : "m" (sc->sc_fpregs[0]),
+				    "m" (sc->sc_fpcntl[0]),
+				    "m" (sc->sc_fpcntl[1]),
+				    "m" (sc->sc_fpcntl[2]));
+	    } else {
+		__asm__ volatile (".chip 68k/68881\n\t"
+				  "fmovemx %0,%%fp0-%%fp1\n\t"
+				  "fmoveml %1,%%fpcr/%%fpsr/%%fpiar\n\t"
+				  ".chip 68k"
+				  : /* no outputs */
+				  : "m" (*sc->sc_fpregs),
+				    "m" (*sc->sc_fpcntl));
+	    }
+	}
+
+	if (CPU_IS_COLDFIRE) {
+		__asm__ volatile ("frestore %0" : : "m" (*sc->sc_fpstate));
+	} else {
+		__asm__ volatile (".chip 68k/68881\n\t"
+				  "frestore %0\n\t"
+				  ".chip 68k"
+				  : : "m" (*sc->sc_fpstate));
+	}
+	err = 0;
+
+out:
+	return err;
+}
+
+static inline int rt_restore_fpu_state(struct ucontext __user *uc)
+{
+	unsigned char fpstate[FPCONTEXT_SIZE];
+	int context_size = CPU_IS_060 ? 8 : (CPU_IS_COLDFIRE ? 12 : 0);
+	fpregset_t fpregs;
+	int err = 1;
+
+	if (FPU_IS_EMU) {
+		/* restore fpu control register */
+		if (__copy_from_user(current->thread.fpcntl,
+				uc->uc_mcontext.fpregs.f_fpcntl, 12))
+			goto out;
+		/* restore all other fpu register */
+		if (__copy_from_user(current->thread.fp,
+				uc->uc_mcontext.fpregs.f_fpregs, 96))
+			goto out;
+		return 0;
+	}
+
+	if (__get_user(*(long *)fpstate, (long __user *)&uc->uc_fpstate))
+		goto out;
+	if (CPU_IS_060 ? fpstate[2] : fpstate[0]) {
+		if (!(CPU_IS_060 || CPU_IS_COLDFIRE))
+			context_size = fpstate[1];
+		/* Verify the frame format.  */
+		if (!(CPU_IS_060 || CPU_IS_COLDFIRE) &&
+		     (fpstate[0] != fpu_version))
+			goto out;
+		if (CPU_IS_020_OR_030) {
+			if (m68k_fputype & FPU_68881 &&
+			    !(context_size == 0x18 || context_size == 0xb4))
+				goto out;
+			if (m68k_fputype & FPU_68882 &&
+			    !(context_size == 0x38 || context_size == 0xd4))
+				goto out;
+		} else if (CPU_IS_040) {
+			if (!(context_size == 0x00 ||
+			      context_size == 0x28 ||
+			      context_size == 0x60))
+				goto out;
+		} else if (CPU_IS_060) {
+			if (!(fpstate[3] == 0x00 ||
+			      fpstate[3] == 0x60 ||
+			      fpstate[3] == 0xe0))
+				goto out;
+		} else if (CPU_IS_COLDFIRE) {
+			if (!(fpstate[3] == 0x00 ||
+			      fpstate[3] == 0x05 ||
+			      fpstate[3] == 0xe5))
+				goto out;
+		} else
+			goto out;
+		if (__copy_from_user(&fpregs, &uc->uc_mcontext.fpregs,
+				     sizeof(fpregs)))
+			goto out;
+
+		if (CPU_IS_COLDFIRE) {
+			__asm__ volatile ("fmovemd %0,%%fp0-%%fp7\n\t"
+					  "fmovel %1,%%fpcr\n\t"
+					  "fmovel %2,%%fpsr\n\t"
+					  "fmovel %3,%%fpiar"
+					  : /* no outputs */
+					  : "m" (fpregs.f_fpregs[0]),
+					    "m" (fpregs.f_fpcntl[0]),
+					    "m" (fpregs.f_fpcntl[1]),
+					    "m" (fpregs.f_fpcntl[2]));
+		} else {
+			__asm__ volatile (".chip 68k/68881\n\t"
+					  "fmovemx %0,%%fp0-%%fp7\n\t"
+					  "fmoveml %1,%%fpcr/%%fpsr/%%fpiar\n\t"
+					  ".chip 68k"
+					  : /* no outputs */
+					  : "m" (*fpregs.f_fpregs),
+					    "m" (*fpregs.f_fpcntl));
+		}
+	}
+	if (context_size &&
+	    __copy_from_user(fpstate + 4, (long __user *)&uc->uc_fpstate + 1,
+			     context_size))
+		goto out;
+
+	if (CPU_IS_COLDFIRE) {
+		__asm__ volatile ("frestore %0" : : "m" (*fpstate));
+	} else {
+		__asm__ volatile (".chip 68k/68881\n\t"
+				  "frestore %0\n\t"
+				  ".chip 68k"
+				  : : "m" (*fpstate));
+	}
+	err = 0;
+
+out:
+	return err;
+}
+
+/*
+ * Set up a signal frame.
+ */
+static inline void save_fpu_state(struct sigcontext *sc, struct pt_regs *regs)
+{
+	if (FPU_IS_EMU) {
+		/* save registers */
+		memcpy(sc->sc_fpcntl, current->thread.fpcntl, 12);
+		memcpy(sc->sc_fpregs, current->thread.fp, 24);
+		return;
+	}
+
+	if (CPU_IS_COLDFIRE) {
+		__asm__ volatile ("fsave %0"
+				  : : "m" (*sc->sc_fpstate) : "memory");
+	} else {
+		__asm__ volatile (".chip 68k/68881\n\t"
+				  "fsave %0\n\t"
+				  ".chip 68k"
+				  : : "m" (*sc->sc_fpstate) : "memory");
+	}
+
+	if (CPU_IS_060 ? sc->sc_fpstate[2] : sc->sc_fpstate[0]) {
+		fpu_version = sc->sc_fpstate[0];
+		if (CPU_IS_020_OR_030 &&
+		    regs->vector >= (VEC_FPBRUC * 4) &&
+		    regs->vector <= (VEC_FPNAN * 4)) {
+			/* Clear pending exception in 68882 idle frame */
+			if (*(unsigned short *) sc->sc_fpstate == 0x1f38)
+				sc->sc_fpstate[0x38] |= 1 << 3;
+		}
+
+		if (CPU_IS_COLDFIRE) {
+			__asm__ volatile ("fmovemd %%fp0-%%fp1,%0\n\t"
+					  "fmovel %%fpcr,%1\n\t"
+					  "fmovel %%fpsr,%2\n\t"
+					  "fmovel %%fpiar,%3"
+					  : "=m" (sc->sc_fpregs[0]),
+					    "=m" (sc->sc_fpcntl[0]),
+					    "=m" (sc->sc_fpcntl[1]),
+					    "=m" (sc->sc_fpcntl[2])
+					  : /* no inputs */
+					  : "memory");
+		} else {
+			__asm__ volatile (".chip 68k/68881\n\t"
+					  "fmovemx %%fp0-%%fp1,%0\n\t"
+					  "fmoveml %%fpcr/%%fpsr/%%fpiar,%1\n\t"
+					  ".chip 68k"
+					  : "=m" (*sc->sc_fpregs),
+					    "=m" (*sc->sc_fpcntl)
+					  : /* no inputs */
+					  : "memory");
+		}
+	}
+}
+
+static inline int rt_save_fpu_state(struct ucontext __user *uc, struct pt_regs *regs)
+{
+	unsigned char fpstate[FPCONTEXT_SIZE];
+	int context_size = CPU_IS_060 ? 8 : (CPU_IS_COLDFIRE ? 12 : 0);
+	int err = 0;
+
+	if (FPU_IS_EMU) {
+		/* save fpu control register */
+		err |= copy_to_user(uc->uc_mcontext.fpregs.f_fpcntl,
+				current->thread.fpcntl, 12);
+		/* save all other fpu register */
+		err |= copy_to_user(uc->uc_mcontext.fpregs.f_fpregs,
+				current->thread.fp, 96);
+		return err;
+	}
+
+	if (CPU_IS_COLDFIRE) {
+		__asm__ volatile ("fsave %0" : : "m" (*fpstate) : "memory");
+	} else {
+		__asm__ volatile (".chip 68k/68881\n\t"
+				  "fsave %0\n\t"
+				  ".chip 68k"
+				  : : "m" (*fpstate) : "memory");
+	}
+
+	err |= __put_user(*(long *)fpstate, (long __user *)&uc->uc_fpstate);
+	if (CPU_IS_060 ? fpstate[2] : fpstate[0]) {
+		fpregset_t fpregs;
+		if (!(CPU_IS_060 || CPU_IS_COLDFIRE))
+			context_size = fpstate[1];
+		fpu_version = fpstate[0];
+		if (CPU_IS_020_OR_030 &&
+		    regs->vector >= (VEC_FPBRUC * 4) &&
+		    regs->vector <= (VEC_FPNAN * 4)) {
+			/* Clear pending exception in 68882 idle frame */
+			if (*(unsigned short *) fpstate == 0x1f38)
+				fpstate[0x38] |= 1 << 3;
+		}
+		if (CPU_IS_COLDFIRE) {
+			__asm__ volatile ("fmovemd %%fp0-%%fp7,%0\n\t"
+					  "fmovel %%fpcr,%1\n\t"
+					  "fmovel %%fpsr,%2\n\t"
+					  "fmovel %%fpiar,%3"
+					  : "=m" (fpregs.f_fpregs[0]),
+					    "=m" (fpregs.f_fpcntl[0]),
+					    "=m" (fpregs.f_fpcntl[1]),
+					    "=m" (fpregs.f_fpcntl[2])
+					  : /* no inputs */
+					  : "memory");
+		} else {
+			__asm__ volatile (".chip 68k/68881\n\t"
+					  "fmovemx %%fp0-%%fp7,%0\n\t"
+					  "fmoveml %%fpcr/%%fpsr/%%fpiar,%1\n\t"
+					  ".chip 68k"
+					  : "=m" (*fpregs.f_fpregs),
+					    "=m" (*fpregs.f_fpcntl)
+					  : /* no inputs */
+					  : "memory");
+		}
+		err |= copy_to_user(&uc->uc_mcontext.fpregs, &fpregs,
+				    sizeof(fpregs));
+	}
+	if (context_size)
+		err |= copy_to_user((long __user *)&uc->uc_fpstate + 1, fpstate + 4,
+				    context_size);
+	return err;
+}
+
+#else /* CONFIG_FPU */
+
+/*
+ * For the case with no FPU configured these all do nothing.
+ */
+static inline int restore_fpu_state(struct sigcontext *sc)
+{
+	return 0;
+}
+
+static inline int rt_restore_fpu_state(struct ucontext __user *uc)
+{
+	return 0;
+}
+
+static inline void save_fpu_state(struct sigcontext *sc, struct pt_regs *regs)
+{
+}
+
+static inline int rt_save_fpu_state(struct ucontext __user *uc, struct pt_regs *regs)
+{
+	return 0;
+}
+
+#endif /* CONFIG_FPU */
+
+static int mangle_kernel_stack(struct pt_regs *regs, int formatvec,
+			       void __user *fp)
+{
+	int fsize = frame_extra_sizes(formatvec >> 12);
+	if (fsize < 0) {
+		/*
+		 * user process trying to return with weird frame format
+		 */
+#ifdef DEBUG
+		printk("user process returning with weird frame format\n");
+#endif
+		return 1;
+	}
+	if (!fsize) {
+		regs->format = formatvec >> 12;
+		regs->vector = formatvec & 0xfff;
+	} else {
+		struct switch_stack *sw = (struct switch_stack *)regs - 1;
+		unsigned long buf[fsize / 2]; /* yes, twice as much */
+
+		/* that'll make sure that expansion won't crap over data */
+		if (copy_from_user(buf + fsize / 4, fp, fsize))
+			return 1;
+
+		/* point of no return */
+		regs->format = formatvec >> 12;
+		regs->vector = formatvec & 0xfff;
+#define frame_offset (sizeof(struct pt_regs)+sizeof(struct switch_stack))
+		__asm__ __volatile__ (
+#ifdef CONFIG_COLDFIRE
+			 "   movel %0,%/sp\n\t"
+			 "   bra ret_from_signal\n"
+#else
+			 "   movel %0,%/a0\n\t"
+			 "   subl %1,%/a0\n\t"     /* make room on stack */
+			 "   movel %/a0,%/sp\n\t"  /* set stack pointer */
+			 /* move switch_stack and pt_regs */
+			 "1: movel %0@+,%/a0@+\n\t"
+			 "   dbra %2,1b\n\t"
+			 "   lea %/sp@(%c3),%/a0\n\t" /* add offset of fmt */
+			 "   lsrl  #2,%1\n\t"
+			 "   subql #1,%1\n\t"
+			 /* copy to the gap we'd made */
+			 "2: movel %4@+,%/a0@+\n\t"
+			 "   dbra %1,2b\n\t"
+			 "   bral ret_from_signal\n"
+#endif
+			 : /* no outputs, it doesn't ever return */
+			 : "a" (sw), "d" (fsize), "d" (frame_offset/4-1),
+			   "n" (frame_offset), "a" (buf + fsize/4)
+			 : "a0");
+#undef frame_offset
+	}
+	return 0;
+}
+
+static inline int
+restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *usc, void __user *fp)
+{
+	int formatvec;
+	struct sigcontext context;
+	int err = 0;
+
+	/* Always make any pending restarted system calls return -EINTR */
+	current_thread_info()->restart_block.fn = do_no_restart_syscall;
+
+	/* get previous context */
+	if (copy_from_user(&context, usc, sizeof(context)))
+		goto badframe;
+
+	/* restore passed registers */
+	regs->d0 = context.sc_d0;
+	regs->d1 = context.sc_d1;
+	regs->a0 = context.sc_a0;
+	regs->a1 = context.sc_a1;
+	regs->sr = (regs->sr & 0xff00) | (context.sc_sr & 0xff);
+	regs->pc = context.sc_pc;
+	regs->orig_d0 = -1;		/* disable syscall checks */
+	wrusp(context.sc_usp);
+	formatvec = context.sc_formatvec;
+
+	err = restore_fpu_state(&context);
+
+	if (err || mangle_kernel_stack(regs, formatvec, fp))
+		goto badframe;
+
+	return 0;
+
+badframe:
+	return 1;
+}
+
+static inline int
+rt_restore_ucontext(struct pt_regs *regs, struct switch_stack *sw,
+		    struct ucontext __user *uc)
+{
+	int temp;
+	greg_t __user *gregs = uc->uc_mcontext.gregs;
+	unsigned long usp;
+	int err;
+
+	/* Always make any pending restarted system calls return -EINTR */
+	current_thread_info()->restart_block.fn = do_no_restart_syscall;
+
+	err = __get_user(temp, &uc->uc_mcontext.version);
+	if (temp != MCONTEXT_VERSION)
+		goto badframe;
+	/* restore passed registers */
+	err |= __get_user(regs->d0, &gregs[0]);
+	err |= __get_user(regs->d1, &gregs[1]);
+	err |= __get_user(regs->d2, &gregs[2]);
+	err |= __get_user(regs->d3, &gregs[3]);
+	err |= __get_user(regs->d4, &gregs[4]);
+	err |= __get_user(regs->d5, &gregs[5]);
+	err |= __get_user(sw->d6, &gregs[6]);
+	err |= __get_user(sw->d7, &gregs[7]);
+	err |= __get_user(regs->a0, &gregs[8]);
+	err |= __get_user(regs->a1, &gregs[9]);
+	err |= __get_user(regs->a2, &gregs[10]);
+	err |= __get_user(sw->a3, &gregs[11]);
+	err |= __get_user(sw->a4, &gregs[12]);
+	err |= __get_user(sw->a5, &gregs[13]);
+	err |= __get_user(sw->a6, &gregs[14]);
+	err |= __get_user(usp, &gregs[15]);
+	wrusp(usp);
+	err |= __get_user(regs->pc, &gregs[16]);
+	err |= __get_user(temp, &gregs[17]);
+	regs->sr = (regs->sr & 0xff00) | (temp & 0xff);
+	regs->orig_d0 = -1;		/* disable syscall checks */
+	err |= __get_user(temp, &uc->uc_formatvec);
+
+	err |= rt_restore_fpu_state(uc);
+
+	if (err || do_sigaltstack(&uc->uc_stack, NULL, usp) == -EFAULT)
+		goto badframe;
+
+	if (mangle_kernel_stack(regs, temp, &uc->uc_extra))
+		goto badframe;
+
+	return 0;
+
+badframe:
+	return 1;
+}
+
+asmlinkage int do_sigreturn(unsigned long __unused)
+{
+	struct switch_stack *sw = (struct switch_stack *) &__unused;
+	struct pt_regs *regs = (struct pt_regs *) (sw + 1);
+	unsigned long usp = rdusp();
+	struct sigframe __user *frame = (struct sigframe __user *)(usp - 4);
+	sigset_t set;
+
+	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
+		goto badframe;
+	if (__get_user(set.sig[0], &frame->sc.sc_mask) ||
+	    (_NSIG_WORDS > 1 &&
+	     __copy_from_user(&set.sig[1], &frame->extramask,
+			      sizeof(frame->extramask))))
+		goto badframe;
+
+	sigdelsetmask(&set, ~_BLOCKABLE);
+	current->blocked = set;
+	recalc_sigpending();
+
+	if (restore_sigcontext(regs, &frame->sc, frame + 1))
+		goto badframe;
+	return regs->d0;
+
+badframe:
+	force_sig(SIGSEGV, current);
+	return 0;
+}
+
+asmlinkage int do_rt_sigreturn(unsigned long __unused)
+{
+	struct switch_stack *sw = (struct switch_stack *) &__unused;
+	struct pt_regs *regs = (struct pt_regs *) (sw + 1);
+	unsigned long usp = rdusp();
+	struct rt_sigframe __user *frame = (struct rt_sigframe __user *)(usp - 4);
+	sigset_t set;
+
+	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
+		goto badframe;
+	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
+		goto badframe;
+
+	sigdelsetmask(&set, ~_BLOCKABLE);
+	current->blocked = set;
+	recalc_sigpending();
+
+	if (rt_restore_ucontext(regs, sw, &frame->uc))
+		goto badframe;
+	return regs->d0;
+
+badframe:
+	force_sig(SIGSEGV, current);
+	return 0;
+}
+
+static void setup_sigcontext(struct sigcontext *sc, struct pt_regs *regs,
+			     unsigned long mask)
+{
+	sc->sc_mask = mask;
+	sc->sc_usp = rdusp();
+	sc->sc_d0 = regs->d0;
+	sc->sc_d1 = regs->d1;
+	sc->sc_a0 = regs->a0;
+	sc->sc_a1 = regs->a1;
+	sc->sc_sr = regs->sr;
+	sc->sc_pc = regs->pc;
+	sc->sc_formatvec = regs->format << 12 | regs->vector;
+	save_a5_state(sc, regs);
+	save_fpu_state(sc, regs);
+}
+
+static inline int rt_setup_ucontext(struct ucontext __user *uc, struct pt_regs *regs)
+{
+	struct switch_stack *sw = (struct switch_stack *)regs - 1;
+	greg_t __user *gregs = uc->uc_mcontext.gregs;
+	int err = 0;
+
+	err |= __put_user(MCONTEXT_VERSION, &uc->uc_mcontext.version);
+	err |= __put_user(regs->d0, &gregs[0]);
+	err |= __put_user(regs->d1, &gregs[1]);
+	err |= __put_user(regs->d2, &gregs[2]);
+	err |= __put_user(regs->d3, &gregs[3]);
+	err |= __put_user(regs->d4, &gregs[4]);
+	err |= __put_user(regs->d5, &gregs[5]);
+	err |= __put_user(sw->d6, &gregs[6]);
+	err |= __put_user(sw->d7, &gregs[7]);
+	err |= __put_user(regs->a0, &gregs[8]);
+	err |= __put_user(regs->a1, &gregs[9]);
+	err |= __put_user(regs->a2, &gregs[10]);
+	err |= __put_user(sw->a3, &gregs[11]);
+	err |= __put_user(sw->a4, &gregs[12]);
+	err |= __put_user(sw->a5, &gregs[13]);
+	err |= __put_user(sw->a6, &gregs[14]);
+	err |= __put_user(rdusp(), &gregs[15]);
+	err |= __put_user(regs->pc, &gregs[16]);
+	err |= __put_user(regs->sr, &gregs[17]);
+	err |= __put_user((regs->format << 12) | regs->vector, &uc->uc_formatvec);
+	err |= rt_save_fpu_state(uc, regs);
+	return err;
+}
+
+static inline void __user *
+get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size)
+{
+	unsigned long usp;
+
+	/* Default to using normal stack.  */
+	usp = rdusp();
+
+	/* This is the X/Open sanctioned signal stack switching.  */
+	if (ka->sa.sa_flags & SA_ONSTACK) {
+		if (!sas_ss_flags(usp))
+			usp = current->sas_ss_sp + current->sas_ss_size;
+	}
+	return (void __user *)((usp - frame_size) & -8UL);
+}
+
+static int setup_frame (int sig, struct k_sigaction *ka,
+			 sigset_t *set, struct pt_regs *regs)
+{
+	struct sigframe __user *frame;
+	int fsize = frame_extra_sizes(regs->format);
+	struct sigcontext context;
+	int err = 0;
+
+	if (fsize < 0) {
+#ifdef DEBUG
+		printk ("setup_frame: Unknown frame format %#x\n",
+			regs->format);
+#endif
+		goto give_sigsegv;
+	}
+
+	frame = get_sigframe(ka, regs, sizeof(*frame) + fsize);
+
+	if (fsize)
+		err |= copy_to_user (frame + 1, regs + 1, fsize);
+
+	err |= __put_user((current_thread_info()->exec_domain
+			   && current_thread_info()->exec_domain->signal_invmap
+			   && sig < 32
+			   ? current_thread_info()->exec_domain->signal_invmap[sig]
+			   : sig),
+			  &frame->sig);
+
+	err |= __put_user(regs->vector, &frame->code);
+	err |= __put_user(&frame->sc, &frame->psc);
+
+	if (_NSIG_WORDS > 1)
+		err |= copy_to_user(frame->extramask, &set->sig[1],
+				    sizeof(frame->extramask));
+
+	setup_sigcontext(&context, regs, set->sig[0]);
+	err |= copy_to_user (&frame->sc, &context, sizeof(context));
+
+	/* Set up to return from userspace.  */
+#ifdef CONFIG_MMU
+	err |= __put_user(frame->retcode, &frame->pretcode);
+	/* moveq #,d0; trap #0 */
+	err |= __put_user(0x70004e40 + (__NR_sigreturn << 16),
+			  (long __user *)(frame->retcode));
+#else
+	err |= __put_user((void *) ret_from_user_signal, &frame->pretcode);
+#endif
+
+	if (err)
+		goto give_sigsegv;
+
+	push_cache ((unsigned long) &frame->retcode);
+
+	/*
+	 * Set up registers for signal handler.  All the state we are about
+	 * to destroy is successfully copied to sigframe.
+	 */
+	wrusp ((unsigned long) frame);
+	regs->pc = (unsigned long) ka->sa.sa_handler;
+	adjustformat(regs);
+
+	/*
+	 * This is subtle; if we build more than one sigframe, all but the
+	 * first one will see frame format 0 and have fsize == 0, so we won't
+	 * screw stkadj.
+	 */
+	if (fsize)
+		regs->stkadj = fsize;
+
+	/* Prepare to skip over the extra stuff in the exception frame.  */
+	if (regs->stkadj) {
+		struct pt_regs *tregs =
+			(struct pt_regs *)((ulong)regs + regs->stkadj);
+#ifdef DEBUG
+		printk("Performing stackadjust=%04x\n", regs->stkadj);
+#endif
+		/* This must be copied with decreasing addresses to
+                   handle overlaps.  */
+		tregs->vector = 0;
+		tregs->format = 0;
+		tregs->pc = regs->pc;
+		tregs->sr = regs->sr;
+	}
+	return 0;
+
+give_sigsegv:
+	force_sigsegv(sig, current);
+	return err;
+}
+
+static int setup_rt_frame (int sig, struct k_sigaction *ka, siginfo_t *info,
+			    sigset_t *set, struct pt_regs *regs)
+{
+	struct rt_sigframe __user *frame;
+	int fsize = frame_extra_sizes(regs->format);
+	int err = 0;
+
+	if (fsize < 0) {
+#ifdef DEBUG
+		printk ("setup_frame: Unknown frame format %#x\n",
+			regs->format);
+#endif
+		goto give_sigsegv;
+	}
+
+	frame = get_sigframe(ka, regs, sizeof(*frame));
+
+	if (fsize)
+		err |= copy_to_user (&frame->uc.uc_extra, regs + 1, fsize);
+
+	err |= __put_user((current_thread_info()->exec_domain
+			   && current_thread_info()->exec_domain->signal_invmap
+			   && sig < 32
+			   ? current_thread_info()->exec_domain->signal_invmap[sig]
+			   : sig),
+			  &frame->sig);
+	err |= __put_user(&frame->info, &frame->pinfo);
+	err |= __put_user(&frame->uc, &frame->puc);
+	err |= copy_siginfo_to_user(&frame->info, info);
+
+	/* Create the ucontext.  */
+	err |= __put_user(0, &frame->uc.uc_flags);
+	err |= __put_user(NULL, &frame->uc.uc_link);
+	err |= __put_user((void __user *)current->sas_ss_sp,
+			  &frame->uc.uc_stack.ss_sp);
+	err |= __put_user(sas_ss_flags(rdusp()),
+			  &frame->uc.uc_stack.ss_flags);
+	err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
+	err |= rt_setup_ucontext(&frame->uc, regs);
+	err |= copy_to_user (&frame->uc.uc_sigmask, set, sizeof(*set));
+
+	/* Set up to return from userspace.  */
+#ifdef CONFIG_MMU
+	err |= __put_user(frame->retcode, &frame->pretcode);
+#ifdef __mcoldfire__
+	/* movel #__NR_rt_sigreturn,d0; trap #0 */
+	err |= __put_user(0x203c0000, (long __user *)(frame->retcode + 0));
+	err |= __put_user(0x00004e40 + (__NR_rt_sigreturn << 16),
+			  (long __user *)(frame->retcode + 4));
+#else
+	/* moveq #,d0; notb d0; trap #0 */
+	err |= __put_user(0x70004600 + ((__NR_rt_sigreturn ^ 0xff) << 16),
+			  (long __user *)(frame->retcode + 0));
+	err |= __put_user(0x4e40, (short __user *)(frame->retcode + 4));
+#endif
+#else
+	err |= __put_user((void *) ret_from_user_rt_signal, &frame->pretcode);
+#endif /* CONFIG_MMU */
+
+	if (err)
+		goto give_sigsegv;
+
+	push_cache ((unsigned long) &frame->retcode);
+
+	/*
+	 * Set up registers for signal handler.  All the state we are about
+	 * to destroy is successfully copied to sigframe.
+	 */
+	wrusp ((unsigned long) frame);
+	regs->pc = (unsigned long) ka->sa.sa_handler;
+	adjustformat(regs);
+
+	/*
+	 * This is subtle; if we build more than one sigframe, all but the
+	 * first one will see frame format 0 and have fsize == 0, so we won't
+	 * screw stkadj.
+	 */
+	if (fsize)
+		regs->stkadj = fsize;
+
+	/* Prepare to skip over the extra stuff in the exception frame.  */
+	if (regs->stkadj) {
+		struct pt_regs *tregs =
+			(struct pt_regs *)((ulong)regs + regs->stkadj);
+#ifdef DEBUG
+		printk("Performing stackadjust=%04x\n", regs->stkadj);
+#endif
+		/* This must be copied with decreasing addresses to
+                   handle overlaps.  */
+		tregs->vector = 0;
+		tregs->format = 0;
+		tregs->pc = regs->pc;
+		tregs->sr = regs->sr;
+	}
+	return 0;
+
+give_sigsegv:
+	force_sigsegv(sig, current);
+	return err;
+}
+
+static inline void
+handle_restart(struct pt_regs *regs, struct k_sigaction *ka, int has_handler)
+{
+	switch (regs->d0) {
+	case -ERESTARTNOHAND:
+		if (!has_handler)
+			goto do_restart;
+		regs->d0 = -EINTR;
+		break;
+
+	case -ERESTART_RESTARTBLOCK:
+		if (!has_handler) {
+			regs->d0 = __NR_restart_syscall;
+			regs->pc -= 2;
+			break;
+		}
+		regs->d0 = -EINTR;
+		break;
+
+	case -ERESTARTSYS:
+		if (has_handler && !(ka->sa.sa_flags & SA_RESTART)) {
+			regs->d0 = -EINTR;
+			break;
+		}
+	/* fallthrough */
+	case -ERESTARTNOINTR:
+	do_restart:
+		regs->d0 = regs->orig_d0;
+		regs->pc -= 2;
+		break;
+	}
+}
+
+/*
+ * OK, we're invoking a handler
+ */
+static void
+handle_signal(int sig, struct k_sigaction *ka, siginfo_t *info,
+	      sigset_t *oldset, struct pt_regs *regs)
+{
+	int err;
+	/* are we from a system call? */
+	if (regs->orig_d0 >= 0)
+		/* If so, check system call restarting.. */
+		handle_restart(regs, ka, 1);
+
+	/* set up the stack frame */
+	if (ka->sa.sa_flags & SA_SIGINFO)
+		err = setup_rt_frame(sig, ka, info, oldset, regs);
+	else
+		err = setup_frame(sig, ka, oldset, regs);
+
+	if (err)
+		return;
+
+	sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
+	if (!(ka->sa.sa_flags & SA_NODEFER))
+		sigaddset(&current->blocked,sig);
+	recalc_sigpending();
+
+	if (test_thread_flag(TIF_DELAYED_TRACE)) {
+		regs->sr &= ~0x8000;
+		send_sig(SIGTRAP, current, 1);
+	}
+
+	clear_thread_flag(TIF_RESTORE_SIGMASK);
+}
+
+/*
+ * Note that 'init' is a special process: it doesn't get signals it doesn't
+ * want to handle. Thus you cannot kill init even with a SIGKILL even by
+ * mistake.
+ */
+asmlinkage void do_signal(struct pt_regs *regs)
+{
+	siginfo_t info;
+	struct k_sigaction ka;
+	int signr;
+	sigset_t *oldset;
+
+	current->thread.esp0 = (unsigned long) regs;
+
+	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) {
+		/* Whee!  Actually deliver the signal.  */
+		handle_signal(signr, &ka, &info, oldset, regs);
+		return;
+	}
+
+	/* Did we come from a system call? */
+	if (regs->orig_d0 >= 0)
+		/* Restart the system call - no handlers present */
+		handle_restart(regs, NULL, 0);
+
+	/* If there's no signal to deliver, we just restore the saved mask.  */
+	if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
+		clear_thread_flag(TIF_RESTORE_SIGMASK);
+		sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
+	}
+}