sh: Move in the SH-5 signal trampoline impl.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 754 insertions, 0 deletions

diff --git a/arch/sh/kernel/signal_64.c b/arch/sh/kernel/signal_64.c
new file mode 100644
index 00000000000..96ba81f324b
--- /dev/null
+++ b/arch/sh/kernel/signal_64.c
@@ -0,0 +1,754 @@
+/*
+ * 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.
+ *
+ * arch/sh64/kernel/signal.c
+ *
+ * Copyright (C) 2000, 2001  Paolo Alberelli
+ * Copyright (C) 2003  Paul Mundt
+ * Copyright (C) 2004  Richard Curnow
+ *
+ * Started from sh version.
+ *
+ */
+#include <linux/rwsem.h>
+#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/personality.h>
+#include <linux/freezer.h>
+#include <linux/ptrace.h>
+#include <linux/unistd.h>
+#include <linux/stddef.h>
+#include <asm/ucontext.h>
+#include <asm/uaccess.h>
+#include <asm/pgtable.h>
+#include <asm/cacheflush.h>
+
+#define REG_RET 9
+#define REG_ARG1 2
+#define REG_ARG2 3
+#define REG_ARG3 4
+#define REG_SP 15
+#define REG_PR 18
+#define REF_REG_RET regs->regs[REG_RET]
+#define REF_REG_SP regs->regs[REG_SP]
+#define DEREF_REG_PR regs->regs[REG_PR]
+
+#define DEBUG_SIG 0
+
+#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
+
+asmlinkage int do_signal(struct pt_regs *regs, sigset_t *oldset);
+
+/*
+ * Atomically swap in the new signal mask, and wait for a signal.
+ */
+
+asmlinkage int
+sys_sigsuspend(old_sigset_t mask,
+	       unsigned long r3, unsigned long r4, unsigned long r5,
+	       unsigned long r6, unsigned long r7,
+	       struct pt_regs * regs)
+{
+	sigset_t saveset;
+
+	mask &= _BLOCKABLE;
+	spin_lock_irq(&current->sighand->siglock);
+	saveset = current->blocked;
+	siginitset(&current->blocked, mask);
+	recalc_sigpending();
+	spin_unlock_irq(&current->sighand->siglock);
+
+	REF_REG_RET = -EINTR;
+	while (1) {
+		current->state = TASK_INTERRUPTIBLE;
+		schedule();
+		regs->pc += 4;    /* because sys_sigreturn decrements the pc */
+		if (do_signal(regs, &saveset)) {
+			/* pc now points at signal handler. Need to decrement
+			   it because entry.S will increment it. */
+			regs->pc -= 4;
+			return -EINTR;
+		}
+	}
+}
+
+asmlinkage int
+sys_rt_sigsuspend(sigset_t *unewset, size_t sigsetsize,
+	          unsigned long r4, unsigned long r5, unsigned long r6,
+	          unsigned long r7,
+	          struct pt_regs * regs)
+{
+	sigset_t saveset, newset;
+
+	/* XXX: Don't preclude handling different sized sigset_t's.  */
+	if (sigsetsize != sizeof(sigset_t))
+		return -EINVAL;
+
+	if (copy_from_user(&newset, unewset, sizeof(newset)))
+		return -EFAULT;
+	sigdelsetmask(&newset, ~_BLOCKABLE);
+	spin_lock_irq(&current->sighand->siglock);
+	saveset = current->blocked;
+	current->blocked = newset;
+	recalc_sigpending();
+	spin_unlock_irq(&current->sighand->siglock);
+
+	REF_REG_RET = -EINTR;
+	while (1) {
+		current->state = TASK_INTERRUPTIBLE;
+		schedule();
+		regs->pc += 4;    /* because sys_sigreturn decrements the pc */
+		if (do_signal(regs, &saveset)) {
+			/* pc now points at signal handler. Need to decrement
+			   it because entry.S will increment it. */
+			regs->pc -= 4;
+			return -EINTR;
+		}
+	}
+}
+
+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))
+			return -EFAULT;
+		__get_user(new_ka.sa.sa_flags, &act->sa_flags);
+		__get_user(mask, &act->sa_mask);
+		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))
+			return -EFAULT;
+		__put_user(old_ka.sa.sa_flags, &oact->sa_flags);
+		__put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
+	}
+
+	return ret;
+}
+
+asmlinkage int
+sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
+	        unsigned long r4, unsigned long r5, unsigned long r6,
+	        unsigned long r7,
+	        struct pt_regs * regs)
+{
+	return do_sigaltstack(uss, uoss, REF_REG_SP);
+}
+
+
+/*
+ * Do a signal return; undo the signal stack.
+ */
+
+struct sigframe
+{
+	struct sigcontext sc;
+	unsigned long extramask[_NSIG_WORDS-1];
+	long long retcode[2];
+};
+
+struct rt_sigframe
+{
+	struct siginfo __user *pinfo;
+	void *puc;
+	struct siginfo info;
+	struct ucontext uc;
+	long long retcode[2];
+};
+
+#ifdef CONFIG_SH_FPU
+static inline int
+restore_sigcontext_fpu(struct pt_regs *regs, struct sigcontext __user *sc)
+{
+	int err = 0;
+	int fpvalid;
+
+	err |= __get_user (fpvalid, &sc->sc_fpvalid);
+	conditional_used_math(fpvalid);
+	if (! fpvalid)
+		return err;
+
+	if (current == last_task_used_math) {
+		last_task_used_math = NULL;
+		regs->sr |= SR_FD;
+	}
+
+	err |= __copy_from_user(&current->thread.fpu.hard, &sc->sc_fpregs[0],
+				(sizeof(long long) * 32) + (sizeof(int) * 1));
+
+	return err;
+}
+
+static inline int
+setup_sigcontext_fpu(struct pt_regs *regs, struct sigcontext __user *sc)
+{
+	int err = 0;
+	int fpvalid;
+
+	fpvalid = !!used_math();
+	err |= __put_user(fpvalid, &sc->sc_fpvalid);
+	if (! fpvalid)
+		return err;
+
+	if (current == last_task_used_math) {
+		grab_fpu();
+		fpsave(&current->thread.fpu.hard);
+		release_fpu();
+		last_task_used_math = NULL;
+		regs->sr |= SR_FD;
+	}
+
+	err |= __copy_to_user(&sc->sc_fpregs[0], &current->thread.fpu.hard,
+			      (sizeof(long long) * 32) + (sizeof(int) * 1));
+	clear_used_math();
+
+	return err;
+}
+#else
+static inline int
+restore_sigcontext_fpu(struct pt_regs *regs, struct sigcontext __user *sc)
+{
+	return 0;
+}
+static inline int
+setup_sigcontext_fpu(struct pt_regs *regs, struct sigcontext __user *sc)
+{
+	return 0;
+}
+#endif
+
+static int
+restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, long long *r2_p)
+{
+	unsigned int err = 0;
+        unsigned long long current_sr, new_sr;
+#define SR_MASK 0xffff8cfd
+
+#define COPY(x)		err |= __get_user(regs->x, &sc->sc_##x)
+
+	COPY(regs[0]);	COPY(regs[1]);	COPY(regs[2]);	COPY(regs[3]);
+	COPY(regs[4]);	COPY(regs[5]);	COPY(regs[6]);	COPY(regs[7]);
+	COPY(regs[8]);	COPY(regs[9]);  COPY(regs[10]);	COPY(regs[11]);
+	COPY(regs[12]);	COPY(regs[13]);	COPY(regs[14]);	COPY(regs[15]);
+	COPY(regs[16]);	COPY(regs[17]);	COPY(regs[18]);	COPY(regs[19]);
+	COPY(regs[20]);	COPY(regs[21]);	COPY(regs[22]);	COPY(regs[23]);
+	COPY(regs[24]);	COPY(regs[25]);	COPY(regs[26]);	COPY(regs[27]);
+	COPY(regs[28]);	COPY(regs[29]);	COPY(regs[30]);	COPY(regs[31]);
+	COPY(regs[32]);	COPY(regs[33]);	COPY(regs[34]);	COPY(regs[35]);
+	COPY(regs[36]);	COPY(regs[37]);	COPY(regs[38]);	COPY(regs[39]);
+	COPY(regs[40]);	COPY(regs[41]);	COPY(regs[42]);	COPY(regs[43]);
+	COPY(regs[44]);	COPY(regs[45]);	COPY(regs[46]);	COPY(regs[47]);
+	COPY(regs[48]);	COPY(regs[49]);	COPY(regs[50]);	COPY(regs[51]);
+	COPY(regs[52]);	COPY(regs[53]);	COPY(regs[54]);	COPY(regs[55]);
+	COPY(regs[56]);	COPY(regs[57]);	COPY(regs[58]);	COPY(regs[59]);
+	COPY(regs[60]);	COPY(regs[61]);	COPY(regs[62]);
+	COPY(tregs[0]);	COPY(tregs[1]);	COPY(tregs[2]);	COPY(tregs[3]);
+	COPY(tregs[4]);	COPY(tregs[5]);	COPY(tregs[6]);	COPY(tregs[7]);
+
+        /* Prevent the signal handler manipulating SR in a way that can
+           crash the kernel. i.e. only allow S, Q, M, PR, SZ, FR to be
+           modified */
+        current_sr = regs->sr;
+        err |= __get_user(new_sr, &sc->sc_sr);
+        regs->sr &= SR_MASK;
+        regs->sr |= (new_sr & ~SR_MASK);
+
+	COPY(pc);
+
+#undef COPY
+
+	/* Must do this last in case it sets regs->sr.fd (i.e. after rest of sr
+	 * has been restored above.) */
+	err |= restore_sigcontext_fpu(regs, sc);
+
+	regs->syscall_nr = -1;		/* disable syscall checks */
+	err |= __get_user(*r2_p, &sc->sc_regs[REG_RET]);
+	return err;
+}
+
+asmlinkage int sys_sigreturn(unsigned long r2, unsigned long r3,
+				   unsigned long r4, unsigned long r5,
+				   unsigned long r6, unsigned long r7,
+				   struct pt_regs * regs)
+{
+	struct sigframe __user *frame = (struct sigframe __user *) (long) REF_REG_SP;
+	sigset_t set;
+	long long ret;
+
+	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
+		goto badframe;
+
+	if (__get_user(set.sig[0], &frame->sc.oldmask)
+	    || (_NSIG_WORDS > 1
+		&& __copy_from_user(&set.sig[1], &frame->extramask,
+				    sizeof(frame->extramask))))
+		goto badframe;
+
+	sigdelsetmask(&set, ~_BLOCKABLE);
+
+	spin_lock_irq(&current->sighand->siglock);
+	current->blocked = set;
+	recalc_sigpending();
+	spin_unlock_irq(&current->sighand->siglock);
+
+	if (restore_sigcontext(regs, &frame->sc, &ret))
+		goto badframe;
+	regs->pc -= 4;
+
+	return (int) ret;
+
+badframe:
+	force_sig(SIGSEGV, current);
+	return 0;
+}
+
+asmlinkage int sys_rt_sigreturn(unsigned long r2, unsigned long r3,
+				unsigned long r4, unsigned long r5,
+				unsigned long r6, unsigned long r7,
+				struct pt_regs * regs)
+{
+	struct rt_sigframe __user *frame = (struct rt_sigframe __user *) (long) REF_REG_SP;
+	sigset_t set;
+	stack_t __user st;
+	long long ret;
+
+	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);
+	spin_lock_irq(&current->sighand->siglock);
+	current->blocked = set;
+	recalc_sigpending();
+	spin_unlock_irq(&current->sighand->siglock);
+
+	if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &ret))
+		goto badframe;
+	regs->pc -= 4;
+
+	if (__copy_from_user(&st, &frame->uc.uc_stack, sizeof(st)))
+		goto badframe;
+	/* It is more difficult to avoid calling this function than to
+	   call it and ignore errors.  */
+	do_sigaltstack(&st, NULL, REF_REG_SP);
+
+	return (int) ret;
+
+badframe:
+	force_sig(SIGSEGV, current);
+	return 0;
+}
+
+/*
+ * Set up a signal frame.
+ */
+
+static int
+setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
+		 unsigned long mask)
+{
+	int err = 0;
+
+	/* Do this first, otherwise is this sets sr->fd, that value isn't preserved. */
+	err |= setup_sigcontext_fpu(regs, sc);
+
+#define COPY(x)		err |= __put_user(regs->x, &sc->sc_##x)
+
+	COPY(regs[0]);	COPY(regs[1]);	COPY(regs[2]);	COPY(regs[3]);
+	COPY(regs[4]);	COPY(regs[5]);	COPY(regs[6]);	COPY(regs[7]);
+	COPY(regs[8]);	COPY(regs[9]);	COPY(regs[10]);	COPY(regs[11]);
+	COPY(regs[12]);	COPY(regs[13]);	COPY(regs[14]);	COPY(regs[15]);
+	COPY(regs[16]);	COPY(regs[17]);	COPY(regs[18]);	COPY(regs[19]);
+	COPY(regs[20]);	COPY(regs[21]);	COPY(regs[22]);	COPY(regs[23]);
+	COPY(regs[24]);	COPY(regs[25]);	COPY(regs[26]);	COPY(regs[27]);
+	COPY(regs[28]);	COPY(regs[29]);	COPY(regs[30]);	COPY(regs[31]);
+	COPY(regs[32]);	COPY(regs[33]);	COPY(regs[34]);	COPY(regs[35]);
+	COPY(regs[36]);	COPY(regs[37]);	COPY(regs[38]);	COPY(regs[39]);
+	COPY(regs[40]);	COPY(regs[41]);	COPY(regs[42]);	COPY(regs[43]);
+	COPY(regs[44]);	COPY(regs[45]);	COPY(regs[46]);	COPY(regs[47]);
+	COPY(regs[48]);	COPY(regs[49]);	COPY(regs[50]);	COPY(regs[51]);
+	COPY(regs[52]);	COPY(regs[53]);	COPY(regs[54]);	COPY(regs[55]);
+	COPY(regs[56]);	COPY(regs[57]);	COPY(regs[58]);	COPY(regs[59]);
+	COPY(regs[60]);	COPY(regs[61]);	COPY(regs[62]);
+	COPY(tregs[0]);	COPY(tregs[1]);	COPY(tregs[2]);	COPY(tregs[3]);
+	COPY(tregs[4]);	COPY(tregs[5]);	COPY(tregs[6]);	COPY(tregs[7]);
+	COPY(sr);	COPY(pc);
+
+#undef COPY
+
+	err |= __put_user(mask, &sc->oldmask);
+
+	return err;
+}
+
+/*
+ * Determine which stack to use..
+ */
+static inline void __user *
+get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
+{
+	if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && ! sas_ss_flags(sp))
+		sp = current->sas_ss_sp + current->sas_ss_size;
+
+	return (void __user *)((sp - frame_size) & -8ul);
+}
+
+void sa_default_restorer(void);		/* See comments below */
+void sa_default_rt_restorer(void);	/* See comments below */
+
+static void setup_frame(int sig, struct k_sigaction *ka,
+			sigset_t *set, struct pt_regs *regs)
+{
+	struct sigframe __user *frame;
+	int err = 0;
+	int signal;
+
+	frame = get_sigframe(ka, regs->regs[REG_SP], sizeof(*frame));
+
+	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
+		goto give_sigsegv;
+
+	signal = current_thread_info()->exec_domain
+		&& current_thread_info()->exec_domain->signal_invmap
+		&& sig < 32
+		? current_thread_info()->exec_domain->signal_invmap[sig]
+		: sig;
+
+	err |= setup_sigcontext(&frame->sc, regs, set->sig[0]);
+
+	/* Give up earlier as i386, in case */
+	if (err)
+		goto give_sigsegv;
+
+	if (_NSIG_WORDS > 1) {
+		err |= __copy_to_user(frame->extramask, &set->sig[1],
+				      sizeof(frame->extramask)); }
+
+	/* Give up earlier as i386, in case */
+	if (err)
+		goto give_sigsegv;
+
+	/* Set up to return from userspace.  If provided, use a stub
+	   already in userspace.  */
+	if (ka->sa.sa_flags & SA_RESTORER) {
+		DEREF_REG_PR = (unsigned long) ka->sa.sa_restorer | 0x1;
+
+		/*
+		 * On SH5 all edited pointers are subject to NEFF
+		 */
+		DEREF_REG_PR = (DEREF_REG_PR & NEFF_SIGN) ?
+        		 	(DEREF_REG_PR | NEFF_MASK) : DEREF_REG_PR;
+	} else {
+		/*
+		 * Different approach on SH5.
+	         * . Endianness independent asm code gets placed in entry.S .
+		 *   This is limited to four ASM instructions corresponding
+		 *   to two long longs in size.
+		 * . err checking is done on the else branch only
+		 * . flush_icache_range() is called upon __put_user() only
+		 * . all edited pointers are subject to NEFF
+		 * . being code, linker turns ShMedia bit on, always
+		 *   dereference index -1.
+		 */
+		DEREF_REG_PR = (unsigned long) frame->retcode | 0x01;
+		DEREF_REG_PR = (DEREF_REG_PR & NEFF_SIGN) ?
+        		 	(DEREF_REG_PR | NEFF_MASK) : DEREF_REG_PR;
+
+		if (__copy_to_user(frame->retcode,
+			(unsigned long long)sa_default_restorer & (~1), 16) != 0)
+			goto give_sigsegv;
+
+		/* Cohere the trampoline with the I-cache. */
+		flush_cache_sigtramp(DEREF_REG_PR-1, DEREF_REG_PR-1+16);
+	}
+
+	/*
+	 * Set up registers for signal handler.
+	 * All edited pointers are subject to NEFF.
+	 */
+	regs->regs[REG_SP] = (unsigned long) frame;
+	regs->regs[REG_SP] = (regs->regs[REG_SP] & NEFF_SIGN) ?
+        		 (regs->regs[REG_SP] | NEFF_MASK) : regs->regs[REG_SP];
+	regs->regs[REG_ARG1] = signal; /* Arg for signal handler */
+
+        /* FIXME:
+           The glibc profiling support for SH-5 needs to be passed a sigcontext
+           so it can retrieve the PC.  At some point during 2003 the glibc
+           support was changed to receive the sigcontext through the 2nd
+           argument, but there are still versions of libc.so in use that use
+           the 3rd argument.  Until libc.so is stabilised, pass the sigcontext
+           through both 2nd and 3rd arguments.
+        */
+
+	regs->regs[REG_ARG2] = (unsigned long long)(unsigned long)(signed long)&frame->sc;
+	regs->regs[REG_ARG3] = (unsigned long long)(unsigned long)(signed long)&frame->sc;
+
+	regs->pc = (unsigned long) ka->sa.sa_handler;
+	regs->pc = (regs->pc & NEFF_SIGN) ? (regs->pc | NEFF_MASK) : regs->pc;
+
+	set_fs(USER_DS);
+
+#if DEBUG_SIG
+	/* Broken %016Lx */
+	printk("SIG deliver (#%d,%s:%d): sp=%p pc=%08Lx%08Lx link=%08Lx%08Lx\n",
+		signal,
+		current->comm, current->pid, frame,
+		regs->pc >> 32, regs->pc & 0xffffffff,
+		DEREF_REG_PR >> 32, DEREF_REG_PR & 0xffffffff);
+#endif
+
+	return;
+
+give_sigsegv:
+	force_sigsegv(sig, current);
+}
+
+static void 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 err = 0;
+	int signal;
+
+	frame = get_sigframe(ka, regs->regs[REG_SP], sizeof(*frame));
+
+	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
+		goto give_sigsegv;
+
+	signal = current_thread_info()->exec_domain
+		&& current_thread_info()->exec_domain->signal_invmap
+		&& sig < 32
+		? current_thread_info()->exec_domain->signal_invmap[sig]
+		: sig;
+
+	err |= __put_user(&frame->info, &frame->pinfo);
+	err |= __put_user(&frame->uc, &frame->puc);
+	err |= copy_siginfo_to_user(&frame->info, info);
+
+	/* Give up earlier as i386, in case */
+	if (err)
+		goto give_sigsegv;
+
+	/* Create the ucontext.  */
+	err |= __put_user(0, &frame->uc.uc_flags);
+	err |= __put_user(0, &frame->uc.uc_link);
+	err |= __put_user((void *)current->sas_ss_sp,
+			  &frame->uc.uc_stack.ss_sp);
+	err |= __put_user(sas_ss_flags(regs->regs[REG_SP]),
+			  &frame->uc.uc_stack.ss_flags);
+	err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
+	err |= setup_sigcontext(&frame->uc.uc_mcontext,
+			        regs, set->sig[0]);
+	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
+
+	/* Give up earlier as i386, in case */
+	if (err)
+		goto give_sigsegv;
+
+	/* Set up to return from userspace.  If provided, use a stub
+	   already in userspace.  */
+	if (ka->sa.sa_flags & SA_RESTORER) {
+		DEREF_REG_PR = (unsigned long) ka->sa.sa_restorer | 0x1;
+
+		/*
+		 * On SH5 all edited pointers are subject to NEFF
+		 */
+		DEREF_REG_PR = (DEREF_REG_PR & NEFF_SIGN) ?
+        		 	(DEREF_REG_PR | NEFF_MASK) : DEREF_REG_PR;
+	} else {
+		/*
+		 * Different approach on SH5.
+	         * . Endianness independent asm code gets placed in entry.S .
+		 *   This is limited to four ASM instructions corresponding
+		 *   to two long longs in size.
+		 * . err checking is done on the else branch only
+		 * . flush_icache_range() is called upon __put_user() only
+		 * . all edited pointers are subject to NEFF
+		 * . being code, linker turns ShMedia bit on, always
+		 *   dereference index -1.
+		 */
+
+		DEREF_REG_PR = (unsigned long) frame->retcode | 0x01;
+		DEREF_REG_PR = (DEREF_REG_PR & NEFF_SIGN) ?
+        		 	(DEREF_REG_PR | NEFF_MASK) : DEREF_REG_PR;
+
+		if (__copy_to_user(frame->retcode,
+			(unsigned long long)sa_default_rt_restorer & (~1), 16) != 0)
+			goto give_sigsegv;
+
+		flush_icache_range(DEREF_REG_PR-1, DEREF_REG_PR-1+15);
+	}
+
+	/*
+	 * Set up registers for signal handler.
+	 * All edited pointers are subject to NEFF.
+	 */
+	regs->regs[REG_SP] = (unsigned long) frame;
+	regs->regs[REG_SP] = (regs->regs[REG_SP] & NEFF_SIGN) ?
+        		 (regs->regs[REG_SP] | NEFF_MASK) : regs->regs[REG_SP];
+	regs->regs[REG_ARG1] = signal; /* Arg for signal handler */
+	regs->regs[REG_ARG2] = (unsigned long long)(unsigned long)(signed long)&frame->info;
+	regs->regs[REG_ARG3] = (unsigned long long)(unsigned long)(signed long)&frame->uc.uc_mcontext;
+	regs->pc = (unsigned long) ka->sa.sa_handler;
+	regs->pc = (regs->pc & NEFF_SIGN) ? (regs->pc | NEFF_MASK) : regs->pc;
+
+	set_fs(USER_DS);
+
+#if DEBUG_SIG
+	/* Broken %016Lx */
+	printk("SIG deliver (#%d,%s:%d): sp=%p pc=%08Lx%08Lx link=%08Lx%08Lx\n",
+		signal,
+		current->comm, current->pid, frame,
+		regs->pc >> 32, regs->pc & 0xffffffff,
+		DEREF_REG_PR >> 32, DEREF_REG_PR & 0xffffffff);
+#endif
+
+	return;
+
+give_sigsegv:
+	force_sigsegv(sig, current);
+}
+
+/*
+ * OK, we're invoking a handler
+ */
+
+static void
+handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
+		sigset_t *oldset, struct pt_regs * regs)
+{
+	/* Are we from a system call? */
+	if (regs->syscall_nr >= 0) {
+		/* If so, check system call restarting.. */
+		switch (regs->regs[REG_RET]) {
+			case -ERESTART_RESTARTBLOCK:
+			case -ERESTARTNOHAND:
+				regs->regs[REG_RET] = -EINTR;
+				break;
+
+			case -ERESTARTSYS:
+				if (!(ka->sa.sa_flags & SA_RESTART)) {
+					regs->regs[REG_RET] = -EINTR;
+					break;
+				}
+			/* fallthrough */
+			case -ERESTARTNOINTR:
+				/* Decode syscall # */
+				regs->regs[REG_RET] = regs->syscall_nr;
+				regs->pc -= 4;
+		}
+	}
+
+	/* Set up the stack frame */
+	if (ka->sa.sa_flags & SA_SIGINFO)
+		setup_rt_frame(sig, ka, info, oldset, regs);
+	else
+		setup_frame(sig, ka, oldset, regs);
+
+	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,sig);
+	recalc_sigpending();
+	spin_unlock_irq(&current->sighand->siglock);
+}
+
+/*
+ * 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.
+ *
+ * Note that we go through the signals twice: once to check the signals that
+ * the kernel can handle, and then we build all the user-level signal handling
+ * stack-frames in one go after that.
+ */
+int do_signal(struct pt_regs *regs, sigset_t *oldset)
+{
+	siginfo_t info;
+	int signr;
+	struct k_sigaction ka;
+
+	/*
+	 * We want the common case to go fast, which
+	 * is why we may in certain cases get here from
+	 * kernel mode. Just return without doing anything
+	 * if so.
+	 */
+	if (!user_mode(regs))
+		return 1;
+
+	if (try_to_freeze())
+		goto no_signal;
+
+	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, 0);
+
+	if (signr > 0) {
+		/* Whee!  Actually deliver the signal.  */
+		handle_signal(signr, &info, &ka, oldset, regs);
+
+		/*
+		 * If 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 1;
+	}
+
+no_signal:
+	/* Did we come from a system call? */
+	if (regs->syscall_nr >= 0) {
+		/* Restart the system call - no handlers present */
+		switch (regs->regs[REG_RET]) {
+		case -ERESTARTNOHAND:
+		case -ERESTARTSYS:
+		case -ERESTARTNOINTR:
+			/* Decode Syscall # */
+			regs->regs[REG_RET] = regs->syscall_nr;
+			regs->pc -= 4;
+			break;
+
+		case -ERESTART_RESTARTBLOCK:
+			regs->regs[REG_RET] = __NR_restart_syscall;
+			regs->pc -= 4;
+			break;
+		}
+	}
+
+	/* 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;
+}