arch/sparc64/kernel/signal.c - arm/linux-arm64-legacy - Git at Google

 /*  $Id: signal.c,v 1.60 2002/02/09 19:49:31 davem Exp $
  *  arch/sparc64/kernel/signal.c
  *
  *  Copyright (C) 1991, 1992  Linus Torvalds
  *  Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
  *  Copyright (C) 1996 Miguel de Icaza (miguel@nuclecu.unam.mx)
  *  Copyright (C) 1997 Eddie C. Dost   (ecd@skynet.be)
  *  Copyright (C) 1997,1998 Jakub Jelinek   (jj@sunsite.mff.cuni.cz)
  */

 #include <linux/config.h>
 #ifdef CONFIG_SPARC32_COMPAT
 #include <linux/compat.h>	/* for compat_old_sigset_t */
 #endif
 #include <linux/sched.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/mm.h>
 #include <linux/tty.h>
 #include <linux/smp_lock.h>
 #include <linux/binfmts.h>
 #include <linux/bitops.h>

 #include <asm/uaccess.h>
 #include <asm/ptrace.h>
 #include <asm/svr4.h>
 #include <asm/pgtable.h>
 #include <asm/fpumacro.h>
 #include <asm/uctx.h>
 #include <asm/siginfo.h>
 #include <asm/visasm.h>

 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))

 /* {set, get}context() needed for 64-bit SparcLinux userland. */
 asmlinkage void sparc64_set_context(struct pt_regs *regs)
 {
 	struct ucontext __user *ucp = (struct ucontext __user *)
 		regs->u_regs[UREG_I0];
 	mc_gregset_t __user *grp;
 	unsigned long pc, npc, tstate;
 	unsigned long fp, i7;
 	unsigned char fenab;
 	int err;

 	flush_user_windows();
 	if (get_thread_wsaved()					||
 	    (((unsigned long)ucp) & (sizeof(unsigned long)-1))	||
 	    (!__access_ok(ucp, sizeof(*ucp))))
 		goto do_sigsegv;
 	grp  = &ucp->uc_mcontext.mc_gregs;
 	err  = __get_user(pc, &((*grp)[MC_PC]));
 	err |= __get_user(npc, &((*grp)[MC_NPC]));
 	if (err || ((pc | npc) & 3))
 		goto do_sigsegv;
 	if (regs->u_regs[UREG_I1]) {
 		sigset_t set;

 		if (_NSIG_WORDS == 1) {
 			if (__get_user(set.sig[0], &ucp->uc_sigmask.sig[0]))
 				goto do_sigsegv;
 		} else {
 			if (__copy_from_user(&set, &ucp->uc_sigmask, sizeof(sigset_t)))
 				goto do_sigsegv;
 		}
 		sigdelsetmask(&set, ~_BLOCKABLE);
 		spin_lock_irq(&current->sighand->siglock);
 		current->blocked = set;
 		recalc_sigpending();
 		spin_unlock_irq(&current->sighand->siglock);
 	}
 	if (test_thread_flag(TIF_32BIT)) {
 		pc &= 0xffffffff;
 		npc &= 0xffffffff;
 	}
 	regs->tpc = pc;
 	regs->tnpc = npc;
 	err |= __get_user(regs->y, &((*grp)[MC_Y]));
 	err |= __get_user(tstate, &((*grp)[MC_TSTATE]));
 	regs->tstate &= ~(TSTATE_ASI | TSTATE_ICC | TSTATE_XCC);
 	regs->tstate |= (tstate & (TSTATE_ASI | TSTATE_ICC | TSTATE_XCC));
 	err |= __get_user(regs->u_regs[UREG_G1], (&(*grp)[MC_G1]));
 	err |= __get_user(regs->u_regs[UREG_G2], (&(*grp)[MC_G2]));
 	err |= __get_user(regs->u_regs[UREG_G3], (&(*grp)[MC_G3]));
 	err |= __get_user(regs->u_regs[UREG_G4], (&(*grp)[MC_G4]));
 	err |= __get_user(regs->u_regs[UREG_G5], (&(*grp)[MC_G5]));
 	err |= __get_user(regs->u_regs[UREG_G6], (&(*grp)[MC_G6]));
 	err |= __get_user(regs->u_regs[UREG_G7], (&(*grp)[MC_G7]));
 	err |= __get_user(regs->u_regs[UREG_I0], (&(*grp)[MC_O0]));
 	err |= __get_user(regs->u_regs[UREG_I1], (&(*grp)[MC_O1]));
 	err |= __get_user(regs->u_regs[UREG_I2], (&(*grp)[MC_O2]));
 	err |= __get_user(regs->u_regs[UREG_I3], (&(*grp)[MC_O3]));
 	err |= __get_user(regs->u_regs[UREG_I4], (&(*grp)[MC_O4]));
 	err |= __get_user(regs->u_regs[UREG_I5], (&(*grp)[MC_O5]));
 	err |= __get_user(regs->u_regs[UREG_I6], (&(*grp)[MC_O6]));
 	err |= __get_user(regs->u_regs[UREG_I7], (&(*grp)[MC_O7]));

 	err |= __get_user(fp, &(ucp->uc_mcontext.mc_fp));
 	err |= __get_user(i7, &(ucp->uc_mcontext.mc_i7));
 	err |= __put_user(fp,
 	      (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[6])));
 	err |= __put_user(i7,
 	      (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[7])));

 	err |= __get_user(fenab, &(ucp->uc_mcontext.mc_fpregs.mcfpu_enab));
 	if (fenab) {
 		unsigned long *fpregs = current_thread_info()->fpregs;
 		unsigned long fprs;

 		fprs_write(0);
 		err |= __get_user(fprs, &(ucp->uc_mcontext.mc_fpregs.mcfpu_fprs));
 		if (fprs & FPRS_DL)
 			err |= copy_from_user(fpregs,
 					      &(ucp->uc_mcontext.mc_fpregs.mcfpu_fregs),
 					      (sizeof(unsigned int) * 32));
 		if (fprs & FPRS_DU)
 			err |= copy_from_user(fpregs+16,
 			 ((unsigned long __user *)&(ucp->uc_mcontext.mc_fpregs.mcfpu_fregs))+16,
 			 (sizeof(unsigned int) * 32));
 		err |= __get_user(current_thread_info()->xfsr[0],
 				  &(ucp->uc_mcontext.mc_fpregs.mcfpu_fsr));
 		err |= __get_user(current_thread_info()->gsr[0],
 				  &(ucp->uc_mcontext.mc_fpregs.mcfpu_gsr));
 		regs->tstate &= ~TSTATE_PEF;
 	}
 	if (err)
 		goto do_sigsegv;

 	return;
 do_sigsegv:
 	force_sig(SIGSEGV, current);
 }

 asmlinkage void sparc64_get_context(struct pt_regs *regs)
 {
 	struct ucontext __user *ucp = (struct ucontext __user *)
 		regs->u_regs[UREG_I0];
 	mc_gregset_t __user *grp;
 	mcontext_t __user *mcp;
 	unsigned long fp, i7;
 	unsigned char fenab;
 	int err;

 	synchronize_user_stack();
 	if (get_thread_wsaved() || clear_user(ucp, sizeof(*ucp)))
 		goto do_sigsegv;

 #if 1
 	fenab = 0; /* IMO get_context is like any other system call, thus modifies FPU state -jj */
 #else
 	fenab = (current_thread_info()->fpsaved[0] & FPRS_FEF);
 #endif

 	mcp = &ucp->uc_mcontext;
 	grp = &mcp->mc_gregs;

 	/* Skip over the trap instruction, first. */
 	if (test_thread_flag(TIF_32BIT)) {
 		regs->tpc   = (regs->tnpc & 0xffffffff);
 		regs->tnpc  = (regs->tnpc + 4) & 0xffffffff;
 	} else {
 		regs->tpc   = regs->tnpc;
 		regs->tnpc += 4;
 	}
 	err = 0;
 	if (_NSIG_WORDS == 1)
 		err |= __put_user(current->blocked.sig[0],
 				  (unsigned long __user *)&ucp->uc_sigmask);
 	else
 		err |= __copy_to_user(&ucp->uc_sigmask, &current->blocked,
 				      sizeof(sigset_t));

 	err |= __put_user(regs->tstate, &((*grp)[MC_TSTATE]));
 	err |= __put_user(regs->tpc, &((*grp)[MC_PC]));
 	err |= __put_user(regs->tnpc, &((*grp)[MC_NPC]));
 	err |= __put_user(regs->y, &((*grp)[MC_Y]));
 	err |= __put_user(regs->u_regs[UREG_G1], &((*grp)[MC_G1]));
 	err |= __put_user(regs->u_regs[UREG_G2], &((*grp)[MC_G2]));
 	err |= __put_user(regs->u_regs[UREG_G3], &((*grp)[MC_G3]));
 	err |= __put_user(regs->u_regs[UREG_G4], &((*grp)[MC_G4]));
 	err |= __put_user(regs->u_regs[UREG_G5], &((*grp)[MC_G5]));
 	err |= __put_user(regs->u_regs[UREG_G6], &((*grp)[MC_G6]));
 	err |= __put_user(regs->u_regs[UREG_G7], &((*grp)[MC_G7]));
 	err |= __put_user(regs->u_regs[UREG_I0], &((*grp)[MC_O0]));
 	err |= __put_user(regs->u_regs[UREG_I1], &((*grp)[MC_O1]));
 	err |= __put_user(regs->u_regs[UREG_I2], &((*grp)[MC_O2]));
 	err |= __put_user(regs->u_regs[UREG_I3], &((*grp)[MC_O3]));
 	err |= __put_user(regs->u_regs[UREG_I4], &((*grp)[MC_O4]));
 	err |= __put_user(regs->u_regs[UREG_I5], &((*grp)[MC_O5]));
 	err |= __put_user(regs->u_regs[UREG_I6], &((*grp)[MC_O6]));
 	err |= __put_user(regs->u_regs[UREG_I7], &((*grp)[MC_O7]));

 	err |= __get_user(fp,
 		 (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[6])));
 	err |= __get_user(i7,
 		 (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[7])));
 	err |= __put_user(fp, &(mcp->mc_fp));
 	err |= __put_user(i7, &(mcp->mc_i7));

 	err |= __put_user(fenab, &(mcp->mc_fpregs.mcfpu_enab));
 	if (fenab) {
 		unsigned long *fpregs = current_thread_info()->fpregs;
 		unsigned long fprs;

 		fprs = current_thread_info()->fpsaved[0];
 		if (fprs & FPRS_DL)
 			err |= copy_to_user(&(mcp->mc_fpregs.mcfpu_fregs), fpregs,
 					    (sizeof(unsigned int) * 32));
 		if (fprs & FPRS_DU)
 			err |= copy_to_user(
                           ((unsigned long __user *)&(mcp->mc_fpregs.mcfpu_fregs))+16, fpregs+16,
 			  (sizeof(unsigned int) * 32));
 		err |= __put_user(current_thread_info()->xfsr[0], &(mcp->mc_fpregs.mcfpu_fsr));
 		err |= __put_user(current_thread_info()->gsr[0], &(mcp->mc_fpregs.mcfpu_gsr));
 		err |= __put_user(fprs, &(mcp->mc_fpregs.mcfpu_fprs));
 	}
 	if (err)
 		goto do_sigsegv;

 	return;
 do_sigsegv:
 	force_sig(SIGSEGV, current);
 }

 struct rt_signal_frame {
 	struct sparc_stackf	ss;
 	siginfo_t		info;
 	struct pt_regs		regs;
 	__siginfo_fpu_t __user	*fpu_save;
 	stack_t			stack;
 	sigset_t		mask;
 	__siginfo_fpu_t		fpu_state;
 };

 /* Align macros */
 #define RT_ALIGNEDSZ  (((sizeof(struct rt_signal_frame) + 7) & (~7)))

 static long _sigpause_common(old_sigset_t set)
 {
 	set &= _BLOCKABLE;
 	spin_lock_irq(&current->sighand->siglock);
 	current->saved_sigmask = current->blocked;
 	siginitset(&current->blocked, set);
 	recalc_sigpending();
 	spin_unlock_irq(&current->sighand->siglock);

 	current->state = TASK_INTERRUPTIBLE;
 	schedule();
 	set_thread_flag(TIF_RESTORE_SIGMASK);
 	return -ERESTARTNOHAND;
 }

 asmlinkage long sys_sigpause(unsigned int set)
 {
 	return _sigpause_common(set);
 }

 asmlinkage long sys_sigsuspend(old_sigset_t set)
 {
 	return _sigpause_common(set);
 }

 static inline int
 restore_fpu_state(struct pt_regs *regs, __siginfo_fpu_t __user *fpu)
 {
 	unsigned long *fpregs = current_thread_info()->fpregs;
 	unsigned long fprs;
 	int err;

 	err = __get_user(fprs, &fpu->si_fprs);
 	fprs_write(0);
 	regs->tstate &= ~TSTATE_PEF;
 	if (fprs & FPRS_DL)
 		err |= copy_from_user(fpregs, &fpu->si_float_regs[0],
 		       	       (sizeof(unsigned int) * 32));
 	if (fprs & FPRS_DU)
 		err |= copy_from_user(fpregs+16, &fpu->si_float_regs[32],
 		       	       (sizeof(unsigned int) * 32));
 	err |= __get_user(current_thread_info()->xfsr[0], &fpu->si_fsr);
 	err |= __get_user(current_thread_info()->gsr[0], &fpu->si_gsr);
 	current_thread_info()->fpsaved[0] |= fprs;
 	return err;
 }

 void do_rt_sigreturn(struct pt_regs *regs)
 {
 	struct rt_signal_frame __user *sf;
 	unsigned long tpc, tnpc, tstate;
 	__siginfo_fpu_t __user *fpu_save;
 	mm_segment_t old_fs;
 	sigset_t set;
 	stack_t st;
 	int err;

 	/* Always make any pending restarted system calls return -EINTR */
 	current_thread_info()->restart_block.fn = do_no_restart_syscall;

 	synchronize_user_stack ();
 	sf = (struct rt_signal_frame __user *)
 		(regs->u_regs [UREG_FP] + STACK_BIAS);

 	/* 1. Make sure we are not getting garbage from the user */
 	if (((unsigned long) sf) & 3)
 		goto segv;

 	err = get_user(tpc, &sf->regs.tpc);
 	err |= __get_user(tnpc, &sf->regs.tnpc);
 	if (test_thread_flag(TIF_32BIT)) {
 		tpc &= 0xffffffff;
 		tnpc &= 0xffffffff;
 	}
 	err |= ((tpc | tnpc) & 3);

 	/* 2. Restore the state */
 	err |= __get_user(regs->y, &sf->regs.y);
 	err |= __get_user(tstate, &sf->regs.tstate);
 	err |= copy_from_user(regs->u_regs, sf->regs.u_regs, sizeof(regs->u_regs));

 	/* User can only change condition codes and %asi in %tstate. */
 	regs->tstate &= ~(TSTATE_ASI | TSTATE_ICC | TSTATE_XCC);
 	regs->tstate |= (tstate & (TSTATE_ASI | TSTATE_ICC | TSTATE_XCC));

 	err |= __get_user(fpu_save, &sf->fpu_save);
 	if (fpu_save)
 		err |= restore_fpu_state(regs, &sf->fpu_state);

 	err |= __copy_from_user(&set, &sf->mask, sizeof(sigset_t));
 	err |= __copy_from_user(&st, &sf->stack, sizeof(stack_t));

 	if (err)
 		goto segv;

 	regs->tpc = tpc;
 	regs->tnpc = tnpc;

 	/* It is more difficult to avoid calling this function than to
 	   call it and ignore errors.  */
 	old_fs = get_fs();
 	set_fs(KERNEL_DS);
 	do_sigaltstack((const stack_t __user *) &st, NULL, (unsigned long)sf);
 	set_fs(old_fs);

 	sigdelsetmask(&set, ~_BLOCKABLE);
 	spin_lock_irq(&current->sighand->siglock);
 	current->blocked = set;
 	recalc_sigpending();
 	spin_unlock_irq(&current->sighand->siglock);
 	return;
 segv:
 	force_sig(SIGSEGV, current);
 }

 /* Checks if the fp is valid */
 static int invalid_frame_pointer(void __user *fp, int fplen)
 {
 	if (((unsigned long) fp) & 7)
 		return 1;
 	return 0;
 }

 static inline int
 save_fpu_state(struct pt_regs *regs, __siginfo_fpu_t __user *fpu)
 {
 	unsigned long *fpregs = (unsigned long *)(regs+1);
 	unsigned long fprs;
 	int err = 0;

 	fprs = current_thread_info()->fpsaved[0];
 	if (fprs & FPRS_DL)
 		err |= copy_to_user(&fpu->si_float_regs[0], fpregs,
 				    (sizeof(unsigned int) * 32));
 	if (fprs & FPRS_DU)
 		err |= copy_to_user(&fpu->si_float_regs[32], fpregs+16,
 				    (sizeof(unsigned int) * 32));
 	err |= __put_user(current_thread_info()->xfsr[0], &fpu->si_fsr);
 	err |= __put_user(current_thread_info()->gsr[0], &fpu->si_gsr);
 	err |= __put_user(fprs, &fpu->si_fprs);

 	return err;
 }

 static inline void __user *get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, unsigned long framesize)
 {
 	unsigned long sp;

 	sp = regs->u_regs[UREG_FP] + STACK_BIAS;

 	/* This is the X/Open sanctioned signal stack switching.  */
 	if (ka->sa.sa_flags & SA_ONSTACK) {
 		if (!on_sig_stack(sp) &&
 		    !((current->sas_ss_sp + current->sas_ss_size) & 7))
 			sp = current->sas_ss_sp + current->sas_ss_size;
 	}
 	return (void __user *)(sp - framesize);
 }

 static inline void
 setup_rt_frame(struct k_sigaction *ka, struct pt_regs *regs,
 	       int signo, sigset_t *oldset, siginfo_t *info)
 {
 	struct rt_signal_frame __user *sf;
 	int sigframe_size, err;

 	/* 1. Make sure everything is clean */
 	synchronize_user_stack();
 	save_and_clear_fpu();

 	sigframe_size = RT_ALIGNEDSZ;
 	if (!(current_thread_info()->fpsaved[0] & FPRS_FEF))
 		sigframe_size -= sizeof(__siginfo_fpu_t);

 	sf = (struct rt_signal_frame __user *)
 		get_sigframe(ka, regs, sigframe_size);

 	if (invalid_frame_pointer (sf, sigframe_size))
 		goto sigill;

 	if (get_thread_wsaved() != 0)
 		goto sigill;

 	/* 2. Save the current process state */
 	err = copy_to_user(&sf->regs, regs, sizeof (*regs));

 	if (current_thread_info()->fpsaved[0] & FPRS_FEF) {
 		err |= save_fpu_state(regs, &sf->fpu_state);
 		err |= __put_user((u64)&sf->fpu_state, &sf->fpu_save);
 	} else {
 		err |= __put_user(0, &sf->fpu_save);
 	}

 	/* Setup sigaltstack */
 	err |= __put_user(current->sas_ss_sp, &sf->stack.ss_sp);
 	err |= __put_user(sas_ss_flags(regs->u_regs[UREG_FP]), &sf->stack.ss_flags);
 	err |= __put_user(current->sas_ss_size, &sf->stack.ss_size);

 	err |= copy_to_user(&sf->mask, oldset, sizeof(sigset_t));

 	err |= copy_in_user((u64 __user *)sf,
 			    (u64 __user *)(regs->u_regs[UREG_FP]+STACK_BIAS),
 			    sizeof(struct reg_window));

 	if (info)
 		err |= copy_siginfo_to_user(&sf->info, info);
 	else {
 		err |= __put_user(signo, &sf->info.si_signo);
 		err |= __put_user(SI_NOINFO, &sf->info.si_code);
 	}
 	if (err)
 		goto sigsegv;

 	/* 3. signal handler back-trampoline and parameters */
 	regs->u_regs[UREG_FP] = ((unsigned long) sf) - STACK_BIAS;
 	regs->u_regs[UREG_I0] = signo;
 	regs->u_regs[UREG_I1] = (unsigned long) &sf->info;

 	/* The sigcontext is passed in this way because of how it
 	 * is defined in GLIBC's /usr/include/bits/sigcontext.h
 	 * for sparc64.  It includes the 128 bytes of siginfo_t.
 	 */
 	regs->u_regs[UREG_I2] = (unsigned long) &sf->info;

 	/* 5. signal handler */
 	regs->tpc = (unsigned long) ka->sa.sa_handler;
 	regs->tnpc = (regs->tpc + 4);
 	if (test_thread_flag(TIF_32BIT)) {
 		regs->tpc &= 0xffffffff;
 		regs->tnpc &= 0xffffffff;
 	}
 	/* 4. return to kernel instructions */
 	regs->u_regs[UREG_I7] = (unsigned long)ka->ka_restorer;
 	return;

 sigill:
 	do_exit(SIGILL);
 sigsegv:
 	force_sigsegv(signo, current);
 }

 static inline void handle_signal(unsigned long signr, struct k_sigaction *ka,
 				 siginfo_t *info,
 				 sigset_t *oldset, struct pt_regs *regs)
 {
 	setup_rt_frame(ka, regs, signr, oldset,
 		       (ka->sa.sa_flags & SA_SIGINFO) ? info : NULL);
 	spin_lock_irq(&current->sighand->siglock);
 	sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
 	if (!(ka->sa.sa_flags & SA_NOMASK))
 		sigaddset(&current->blocked,signr);
 	recalc_sigpending();
 	spin_unlock_irq(&current->sighand->siglock);
 }

 static inline void syscall_restart(unsigned long orig_i0, struct pt_regs *regs,
 				     struct sigaction *sa)
 {
 	switch (regs->u_regs[UREG_I0]) {
 	case ERESTART_RESTARTBLOCK:
 	case ERESTARTNOHAND:
 	no_system_call_restart:
 		regs->u_regs[UREG_I0] = EINTR;
 		regs->tstate |= (TSTATE_ICARRY|TSTATE_XCARRY);
 		break;
 	case ERESTARTSYS:
 		if (!(sa->sa_flags & SA_RESTART))
 			goto no_system_call_restart;
 		/* fallthrough */
 	case ERESTARTNOINTR:
 		regs->u_regs[UREG_I0] = orig_i0;
 		regs->tpc -= 4;
 		regs->tnpc -= 4;
 	}
 }

 /* 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.
  */
 static void do_signal(struct pt_regs *regs, unsigned long orig_i0, int restart_syscall)
 {
 	siginfo_t info;
 	struct signal_deliver_cookie cookie;
 	struct k_sigaction ka;
 	int signr;
 	sigset_t *oldset;

 	cookie.restart_syscall = restart_syscall;
 	cookie.orig_i0 = orig_i0;

 	if (test_thread_flag(TIF_RESTORE_SIGMASK))
 		oldset = &current->saved_sigmask;
 	else
 		oldset = &current->blocked;

 #ifdef CONFIG_SPARC32_COMPAT
 	if (test_thread_flag(TIF_32BIT)) {
 		extern void do_signal32(sigset_t *, struct pt_regs *,
 					unsigned long, int);
 		do_signal32(oldset, regs, orig_i0,
 			    cookie.restart_syscall);
 		return;
 	}
 #endif

 	signr = get_signal_to_deliver(&info, &ka, regs, &cookie);
 	if (signr > 0) {
 		if (cookie.restart_syscall)
 			syscall_restart(orig_i0, regs, &ka.sa);
 		handle_signal(signr, &ka, &info, oldset, regs);

 		/* a signal was successfully delivered; the saved
 		 * sigmask will have been stored in the signal frame,
 		 * and will be restored by sigreturn, so we can simply
 		 * clear the TIF_RESTORE_SIGMASK flag.
 		 */
 		if (test_thread_flag(TIF_RESTORE_SIGMASK))
 			clear_thread_flag(TIF_RESTORE_SIGMASK);
 		return;
 	}
 	if (cookie.restart_syscall &&
 	    (regs->u_regs[UREG_I0] == ERESTARTNOHAND ||
 	     regs->u_regs[UREG_I0] == ERESTARTSYS ||
 	     regs->u_regs[UREG_I0] == ERESTARTNOINTR)) {
 		/* replay the system call when we are done */
 		regs->u_regs[UREG_I0] = cookie.orig_i0;
 		regs->tpc -= 4;
 		regs->tnpc -= 4;
 	}
 	if (cookie.restart_syscall &&
 	    regs->u_regs[UREG_I0] == ERESTART_RESTARTBLOCK) {
 		regs->u_regs[UREG_G1] = __NR_restart_syscall;
 		regs->tpc -= 4;
 		regs->tnpc -= 4;
 	}

 	/* if there's no signal to deliver, we just 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);
 	}
 }

 void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0, int restart_syscall,
 		      unsigned long thread_info_flags)
 {
 	if (thread_info_flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK))
 		do_signal(regs, orig_i0, restart_syscall);
 }

 void ptrace_signal_deliver(struct pt_regs *regs, void *cookie)
 {
 	struct signal_deliver_cookie *cp = cookie;

 	if (cp->restart_syscall &&
 	    (regs->u_regs[UREG_I0] == ERESTARTNOHAND ||
 	     regs->u_regs[UREG_I0] == ERESTARTSYS ||
 	     regs->u_regs[UREG_I0] == ERESTARTNOINTR)) {
 		/* replay the system call when we are done */
 		regs->u_regs[UREG_I0] = cp->orig_i0;
 		regs->tpc -= 4;
 		regs->tnpc -= 4;
 		cp->restart_syscall = 0;
 	}
 	if (cp->restart_syscall &&
 	    regs->u_regs[UREG_I0] == ERESTART_RESTARTBLOCK) {
 		regs->u_regs[UREG_G1] = __NR_restart_syscall;
 		regs->tpc -= 4;
 		regs->tnpc -= 4;
 		cp->restart_syscall = 0;
 	}
 }
	/* $Id: signal.c,v 1.60 2002/02/09 19:49:31 davem Exp $
	* arch/sparc64/kernel/signal.c
	*
	* Copyright (C) 1991, 1992 Linus Torvalds
	* Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
	* Copyright (C) 1996 Miguel de Icaza (miguel@nuclecu.unam.mx)
	* Copyright (C) 1997 Eddie C. Dost (ecd@skynet.be)
	* Copyright (C) 1997,1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
	*/

	#include <linux/config.h>
	#ifdef CONFIG_SPARC32_COMPAT
	#include <linux/compat.h> /* for compat_old_sigset_t */
	#endif
	#include <linux/sched.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/mm.h>
	#include <linux/tty.h>
	#include <linux/smp_lock.h>
	#include <linux/binfmts.h>
	#include <linux/bitops.h>

	#include <asm/uaccess.h>
	#include <asm/ptrace.h>
	#include <asm/svr4.h>
	#include <asm/pgtable.h>
	#include <asm/fpumacro.h>
	#include <asm/uctx.h>
	#include <asm/siginfo.h>
	#include <asm/visasm.h>

	#define _BLOCKABLE (~(sigmask(SIGKILL) \| sigmask(SIGSTOP)))

	/* {set, get}context() needed for 64-bit SparcLinux userland. */
	asmlinkage void sparc64_set_context(struct pt_regs *regs)
	{
	struct ucontext __user ucp = (struct ucontext __user )
	regs->u_regs[UREG_I0];
	mc_gregset_t __user *grp;
	unsigned long pc, npc, tstate;
	unsigned long fp, i7;
	unsigned char fenab;
	int err;

	flush_user_windows();
	if (get_thread_wsaved() \|\|
	(((unsigned long)ucp) & (sizeof(unsigned long)-1)) \|\|
	(!__access_ok(ucp, sizeof(*ucp))))
	goto do_sigsegv;
	grp = &ucp->uc_mcontext.mc_gregs;
	err = __get_user(pc, &((*grp)[MC_PC]));
	err \|= __get_user(npc, &((*grp)[MC_NPC]));
	if (err \|\| ((pc \| npc) & 3))
	goto do_sigsegv;
	if (regs->u_regs[UREG_I1]) {
	sigset_t set;

	if (_NSIG_WORDS == 1) {
	if (__get_user(set.sig[0], &ucp->uc_sigmask.sig[0]))
	goto do_sigsegv;
	} else {
	if (__copy_from_user(&set, &ucp->uc_sigmask, sizeof(sigset_t)))
	goto do_sigsegv;
	}
	sigdelsetmask(&set, ~_BLOCKABLE);
	spin_lock_irq(&current->sighand->siglock);
	current->blocked = set;
	recalc_sigpending();
	spin_unlock_irq(&current->sighand->siglock);
	}
	if (test_thread_flag(TIF_32BIT)) {
	pc &= 0xffffffff;
	npc &= 0xffffffff;
	}
	regs->tpc = pc;
	regs->tnpc = npc;
	err \|= __get_user(regs->y, &((*grp)[MC_Y]));
	err \|= __get_user(tstate, &((*grp)[MC_TSTATE]));
	regs->tstate &= ~(TSTATE_ASI \| TSTATE_ICC \| TSTATE_XCC);
	regs->tstate \|= (tstate & (TSTATE_ASI \| TSTATE_ICC \| TSTATE_XCC));
	err \|= __get_user(regs->u_regs[UREG_G1], (&(*grp)[MC_G1]));
	err \|= __get_user(regs->u_regs[UREG_G2], (&(*grp)[MC_G2]));
	err \|= __get_user(regs->u_regs[UREG_G3], (&(*grp)[MC_G3]));
	err \|= __get_user(regs->u_regs[UREG_G4], (&(*grp)[MC_G4]));
	err \|= __get_user(regs->u_regs[UREG_G5], (&(*grp)[MC_G5]));
	err \|= __get_user(regs->u_regs[UREG_G6], (&(*grp)[MC_G6]));
	err \|= __get_user(regs->u_regs[UREG_G7], (&(*grp)[MC_G7]));
	err \|= __get_user(regs->u_regs[UREG_I0], (&(*grp)[MC_O0]));
	err \|= __get_user(regs->u_regs[UREG_I1], (&(*grp)[MC_O1]));
	err \|= __get_user(regs->u_regs[UREG_I2], (&(*grp)[MC_O2]));
	err \|= __get_user(regs->u_regs[UREG_I3], (&(*grp)[MC_O3]));
	err \|= __get_user(regs->u_regs[UREG_I4], (&(*grp)[MC_O4]));
	err \|= __get_user(regs->u_regs[UREG_I5], (&(*grp)[MC_O5]));
	err \|= __get_user(regs->u_regs[UREG_I6], (&(*grp)[MC_O6]));
	err \|= __get_user(regs->u_regs[UREG_I7], (&(*grp)[MC_O7]));

	err \|= __get_user(fp, &(ucp->uc_mcontext.mc_fp));
	err \|= __get_user(i7, &(ucp->uc_mcontext.mc_i7));
	err \|= __put_user(fp,
	(&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[6])));
	err \|= __put_user(i7,
	(&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[7])));

	err \|= __get_user(fenab, &(ucp->uc_mcontext.mc_fpregs.mcfpu_enab));
	if (fenab) {
	unsigned long *fpregs = current_thread_info()->fpregs;
	unsigned long fprs;

	fprs_write(0);
	err \|= __get_user(fprs, &(ucp->uc_mcontext.mc_fpregs.mcfpu_fprs));
	if (fprs & FPRS_DL)
	err \|= copy_from_user(fpregs,
	&(ucp->uc_mcontext.mc_fpregs.mcfpu_fregs),
	(sizeof(unsigned int) * 32));
	if (fprs & FPRS_DU)
	err \|= copy_from_user(fpregs+16,
	((unsigned long __user *)&(ucp->uc_mcontext.mc_fpregs.mcfpu_fregs))+16,
	(sizeof(unsigned int) * 32));
	err \|= __get_user(current_thread_info()->xfsr[0],
	&(ucp->uc_mcontext.mc_fpregs.mcfpu_fsr));
	err \|= __get_user(current_thread_info()->gsr[0],
	&(ucp->uc_mcontext.mc_fpregs.mcfpu_gsr));
	regs->tstate &= ~TSTATE_PEF;
	}
	if (err)
	goto do_sigsegv;

	return;
	do_sigsegv:
	force_sig(SIGSEGV, current);
	}

	asmlinkage void sparc64_get_context(struct pt_regs *regs)
	{
	struct ucontext __user ucp = (struct ucontext __user )
	regs->u_regs[UREG_I0];
	mc_gregset_t __user *grp;
	mcontext_t __user *mcp;
	unsigned long fp, i7;
	unsigned char fenab;
	int err;

	synchronize_user_stack();
	if (get_thread_wsaved() \|\| clear_user(ucp, sizeof(*ucp)))
	goto do_sigsegv;

	#if 1
	fenab = 0; /* IMO get_context is like any other system call, thus modifies FPU state -jj */
	#else
	fenab = (current_thread_info()->fpsaved[0] & FPRS_FEF);
	#endif

	mcp = &ucp->uc_mcontext;
	grp = &mcp->mc_gregs;

	/* Skip over the trap instruction, first. */
	if (test_thread_flag(TIF_32BIT)) {
	regs->tpc = (regs->tnpc & 0xffffffff);
	regs->tnpc = (regs->tnpc + 4) & 0xffffffff;
	} else {
	regs->tpc = regs->tnpc;
	regs->tnpc += 4;
	}
	err = 0;
	if (_NSIG_WORDS == 1)
	err \|= __put_user(current->blocked.sig[0],
	(unsigned long __user *)&ucp->uc_sigmask);
	else
	err \|= __copy_to_user(&ucp->uc_sigmask, &current->blocked,
	sizeof(sigset_t));

	err \|= __put_user(regs->tstate, &((*grp)[MC_TSTATE]));
	err \|= __put_user(regs->tpc, &((*grp)[MC_PC]));
	err \|= __put_user(regs->tnpc, &((*grp)[MC_NPC]));
	err \|= __put_user(regs->y, &((*grp)[MC_Y]));
	err \|= __put_user(regs->u_regs[UREG_G1], &((*grp)[MC_G1]));
	err \|= __put_user(regs->u_regs[UREG_G2], &((*grp)[MC_G2]));
	err \|= __put_user(regs->u_regs[UREG_G3], &((*grp)[MC_G3]));
	err \|= __put_user(regs->u_regs[UREG_G4], &((*grp)[MC_G4]));
	err \|= __put_user(regs->u_regs[UREG_G5], &((*grp)[MC_G5]));
	err \|= __put_user(regs->u_regs[UREG_G6], &((*grp)[MC_G6]));
	err \|= __put_user(regs->u_regs[UREG_G7], &((*grp)[MC_G7]));
	err \|= __put_user(regs->u_regs[UREG_I0], &((*grp)[MC_O0]));
	err \|= __put_user(regs->u_regs[UREG_I1], &((*grp)[MC_O1]));
	err \|= __put_user(regs->u_regs[UREG_I2], &((*grp)[MC_O2]));
	err \|= __put_user(regs->u_regs[UREG_I3], &((*grp)[MC_O3]));
	err \|= __put_user(regs->u_regs[UREG_I4], &((*grp)[MC_O4]));
	err \|= __put_user(regs->u_regs[UREG_I5], &((*grp)[MC_O5]));
	err \|= __put_user(regs->u_regs[UREG_I6], &((*grp)[MC_O6]));
	err \|= __put_user(regs->u_regs[UREG_I7], &((*grp)[MC_O7]));

	err \|= __get_user(fp,
	(&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[6])));
	err \|= __get_user(i7,
	(&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[7])));
	err \|= __put_user(fp, &(mcp->mc_fp));
	err \|= __put_user(i7, &(mcp->mc_i7));

	err \|= __put_user(fenab, &(mcp->mc_fpregs.mcfpu_enab));
	if (fenab) {
	unsigned long *fpregs = current_thread_info()->fpregs;
	unsigned long fprs;

	fprs = current_thread_info()->fpsaved[0];
	if (fprs & FPRS_DL)
	err \|= copy_to_user(&(mcp->mc_fpregs.mcfpu_fregs), fpregs,
	(sizeof(unsigned int) * 32));
	if (fprs & FPRS_DU)
	err \|= copy_to_user(
	((unsigned long __user *)&(mcp->mc_fpregs.mcfpu_fregs))+16, fpregs+16,
	(sizeof(unsigned int) * 32));
	err \|= __put_user(current_thread_info()->xfsr[0], &(mcp->mc_fpregs.mcfpu_fsr));
	err \|= __put_user(current_thread_info()->gsr[0], &(mcp->mc_fpregs.mcfpu_gsr));
	err \|= __put_user(fprs, &(mcp->mc_fpregs.mcfpu_fprs));
	}
	if (err)
	goto do_sigsegv;

	return;
	do_sigsegv:
	force_sig(SIGSEGV, current);
	}

	struct rt_signal_frame {
	struct sparc_stackf ss;
	siginfo_t info;
	struct pt_regs regs;
	__siginfo_fpu_t __user *fpu_save;
	stack_t stack;
	sigset_t mask;
	__siginfo_fpu_t fpu_state;
	};

	/* Align macros */
	#define RT_ALIGNEDSZ (((sizeof(struct rt_signal_frame) + 7) & (~7)))

	static long _sigpause_common(old_sigset_t set)
	{
	set &= _BLOCKABLE;
	spin_lock_irq(&current->sighand->siglock);
	current->saved_sigmask = current->blocked;
	siginitset(&current->blocked, set);
	recalc_sigpending();
	spin_unlock_irq(&current->sighand->siglock);

	current->state = TASK_INTERRUPTIBLE;
	schedule();
	set_thread_flag(TIF_RESTORE_SIGMASK);
	return -ERESTARTNOHAND;
	}

	asmlinkage long sys_sigpause(unsigned int set)
	{
	return _sigpause_common(set);
	}

	asmlinkage long sys_sigsuspend(old_sigset_t set)
	{
	return _sigpause_common(set);
	}

	static inline int
	restore_fpu_state(struct pt_regs regs, __siginfo_fpu_t __user fpu)
	{
	unsigned long *fpregs = current_thread_info()->fpregs;
	unsigned long fprs;
	int err;

	err = __get_user(fprs, &fpu->si_fprs);
	fprs_write(0);
	regs->tstate &= ~TSTATE_PEF;
	if (fprs & FPRS_DL)
	err \|= copy_from_user(fpregs, &fpu->si_float_regs[0],
	(sizeof(unsigned int) * 32));
	if (fprs & FPRS_DU)
	err \|= copy_from_user(fpregs+16, &fpu->si_float_regs[32],
	(sizeof(unsigned int) * 32));
	err \|= __get_user(current_thread_info()->xfsr[0], &fpu->si_fsr);
	err \|= __get_user(current_thread_info()->gsr[0], &fpu->si_gsr);
	current_thread_info()->fpsaved[0] \|= fprs;
	return err;
	}

	void do_rt_sigreturn(struct pt_regs *regs)
	{
	struct rt_signal_frame __user *sf;
	unsigned long tpc, tnpc, tstate;
	__siginfo_fpu_t __user *fpu_save;
	mm_segment_t old_fs;
	sigset_t set;
	stack_t st;
	int err;

	/* Always make any pending restarted system calls return -EINTR */
	current_thread_info()->restart_block.fn = do_no_restart_syscall;

	synchronize_user_stack ();
	sf = (struct rt_signal_frame __user *)
	(regs->u_regs [UREG_FP] + STACK_BIAS);

	/* 1. Make sure we are not getting garbage from the user */
	if (((unsigned long) sf) & 3)
	goto segv;

	err = get_user(tpc, &sf->regs.tpc);
	err \|= __get_user(tnpc, &sf->regs.tnpc);
	if (test_thread_flag(TIF_32BIT)) {
	tpc &= 0xffffffff;
	tnpc &= 0xffffffff;
	}
	err \|= ((tpc \| tnpc) & 3);

	/* 2. Restore the state */
	err \|= __get_user(regs->y, &sf->regs.y);
	err \|= __get_user(tstate, &sf->regs.tstate);
	err \|= copy_from_user(regs->u_regs, sf->regs.u_regs, sizeof(regs->u_regs));

	/* User can only change condition codes and %asi in %tstate. */
	regs->tstate &= ~(TSTATE_ASI \| TSTATE_ICC \| TSTATE_XCC);
	regs->tstate \|= (tstate & (TSTATE_ASI \| TSTATE_ICC \| TSTATE_XCC));

	err \|= __get_user(fpu_save, &sf->fpu_save);
	if (fpu_save)
	err \|= restore_fpu_state(regs, &sf->fpu_state);

	err \|= __copy_from_user(&set, &sf->mask, sizeof(sigset_t));
	err \|= __copy_from_user(&st, &sf->stack, sizeof(stack_t));

	if (err)
	goto segv;

	regs->tpc = tpc;
	regs->tnpc = tnpc;

	/* It is more difficult to avoid calling this function than to
	call it and ignore errors. */
	old_fs = get_fs();
	set_fs(KERNEL_DS);
	do_sigaltstack((const stack_t __user *) &st, NULL, (unsigned long)sf);
	set_fs(old_fs);

	sigdelsetmask(&set, ~_BLOCKABLE);
	spin_lock_irq(&current->sighand->siglock);
	current->blocked = set;
	recalc_sigpending();
	spin_unlock_irq(&current->sighand->siglock);
	return;
	segv:
	force_sig(SIGSEGV, current);
	}

	/* Checks if the fp is valid */
	static int invalid_frame_pointer(void __user *fp, int fplen)
	{
	if (((unsigned long) fp) & 7)
	return 1;
	return 0;
	}

	static inline int
	save_fpu_state(struct pt_regs regs, __siginfo_fpu_t __user fpu)
	{
	unsigned long fpregs = (unsigned long )(regs+1);
	unsigned long fprs;
	int err = 0;

	fprs = current_thread_info()->fpsaved[0];
	if (fprs & FPRS_DL)
	err \|= copy_to_user(&fpu->si_float_regs[0], fpregs,
	(sizeof(unsigned int) * 32));
	if (fprs & FPRS_DU)
	err \|= copy_to_user(&fpu->si_float_regs[32], fpregs+16,
	(sizeof(unsigned int) * 32));
	err \|= __put_user(current_thread_info()->xfsr[0], &fpu->si_fsr);
	err \|= __put_user(current_thread_info()->gsr[0], &fpu->si_gsr);
	err \|= __put_user(fprs, &fpu->si_fprs);

	return err;
	}

	static inline void __user get_sigframe(struct k_sigaction ka, struct pt_regs *regs, unsigned long framesize)
	{
	unsigned long sp;

	sp = regs->u_regs[UREG_FP] + STACK_BIAS;

	/* This is the X/Open sanctioned signal stack switching. */
	if (ka->sa.sa_flags & SA_ONSTACK) {
	if (!on_sig_stack(sp) &&
	!((current->sas_ss_sp + current->sas_ss_size) & 7))
	sp = current->sas_ss_sp + current->sas_ss_size;
	}
	return (void __user *)(sp - framesize);
	}

	static inline void
	setup_rt_frame(struct k_sigaction ka, struct pt_regs regs,
	int signo, sigset_t oldset, siginfo_t info)
	{
	struct rt_signal_frame __user *sf;
	int sigframe_size, err;

	/* 1. Make sure everything is clean */
	synchronize_user_stack();
	save_and_clear_fpu();

	sigframe_size = RT_ALIGNEDSZ;
	if (!(current_thread_info()->fpsaved[0] & FPRS_FEF))
	sigframe_size -= sizeof(__siginfo_fpu_t);

	sf = (struct rt_signal_frame __user *)
	get_sigframe(ka, regs, sigframe_size);

	if (invalid_frame_pointer (sf, sigframe_size))
	goto sigill;

	if (get_thread_wsaved() != 0)
	goto sigill;

	/* 2. Save the current process state */
	err = copy_to_user(&sf->regs, regs, sizeof (*regs));

	if (current_thread_info()->fpsaved[0] & FPRS_FEF) {
	err \|= save_fpu_state(regs, &sf->fpu_state);
	err \|= __put_user((u64)&sf->fpu_state, &sf->fpu_save);
	} else {
	err \|= __put_user(0, &sf->fpu_save);
	}

	/* Setup sigaltstack */
	err \|= __put_user(current->sas_ss_sp, &sf->stack.ss_sp);
	err \|= __put_user(sas_ss_flags(regs->u_regs[UREG_FP]), &sf->stack.ss_flags);
	err \|= __put_user(current->sas_ss_size, &sf->stack.ss_size);

	err \|= copy_to_user(&sf->mask, oldset, sizeof(sigset_t));

	err \|= copy_in_user((u64 __user *)sf,
	(u64 __user *)(regs->u_regs[UREG_FP]+STACK_BIAS),
	sizeof(struct reg_window));

	if (info)
	err \|= copy_siginfo_to_user(&sf->info, info);
	else {
	err \|= __put_user(signo, &sf->info.si_signo);
	err \|= __put_user(SI_NOINFO, &sf->info.si_code);
	}
	if (err)
	goto sigsegv;

	/* 3. signal handler back-trampoline and parameters */
	regs->u_regs[UREG_FP] = ((unsigned long) sf) - STACK_BIAS;
	regs->u_regs[UREG_I0] = signo;
	regs->u_regs[UREG_I1] = (unsigned long) &sf->info;

	/* The sigcontext is passed in this way because of how it
	* is defined in GLIBC's /usr/include/bits/sigcontext.h
	* for sparc64. It includes the 128 bytes of siginfo_t.
	*/
	regs->u_regs[UREG_I2] = (unsigned long) &sf->info;

	/* 5. signal handler */
	regs->tpc = (unsigned long) ka->sa.sa_handler;
	regs->tnpc = (regs->tpc + 4);
	if (test_thread_flag(TIF_32BIT)) {
	regs->tpc &= 0xffffffff;
	regs->tnpc &= 0xffffffff;
	}
	/* 4. return to kernel instructions */
	regs->u_regs[UREG_I7] = (unsigned long)ka->ka_restorer;
	return;

	sigill:
	do_exit(SIGILL);
	sigsegv:
	force_sigsegv(signo, current);
	}

	static inline void handle_signal(unsigned long signr, struct k_sigaction *ka,
	siginfo_t *info,
	sigset_t oldset, struct pt_regs regs)
	{
	setup_rt_frame(ka, regs, signr, oldset,
	(ka->sa.sa_flags & SA_SIGINFO) ? info : NULL);
	spin_lock_irq(&current->sighand->siglock);
	sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
	if (!(ka->sa.sa_flags & SA_NOMASK))
	sigaddset(&current->blocked,signr);
	recalc_sigpending();
	spin_unlock_irq(&current->sighand->siglock);
	}

	static inline void syscall_restart(unsigned long orig_i0, struct pt_regs *regs,
	struct sigaction *sa)
	{
	switch (regs->u_regs[UREG_I0]) {
	case ERESTART_RESTARTBLOCK:
	case ERESTARTNOHAND:
	no_system_call_restart:
	regs->u_regs[UREG_I0] = EINTR;
	regs->tstate \|= (TSTATE_ICARRY\|TSTATE_XCARRY);
	break;
	case ERESTARTSYS:
	if (!(sa->sa_flags & SA_RESTART))
	goto no_system_call_restart;
	/* fallthrough */
	case ERESTARTNOINTR:
	regs->u_regs[UREG_I0] = orig_i0;
	regs->tpc -= 4;
	regs->tnpc -= 4;
	}
	}

	/* 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.
	*/
	static void do_signal(struct pt_regs *regs, unsigned long orig_i0, int restart_syscall)
	{
	siginfo_t info;
	struct signal_deliver_cookie cookie;
	struct k_sigaction ka;
	int signr;
	sigset_t *oldset;

	cookie.restart_syscall = restart_syscall;
	cookie.orig_i0 = orig_i0;

	if (test_thread_flag(TIF_RESTORE_SIGMASK))
	oldset = &current->saved_sigmask;
	else
	oldset = &current->blocked;

	#ifdef CONFIG_SPARC32_COMPAT
	if (test_thread_flag(TIF_32BIT)) {
	extern void do_signal32(sigset_t , struct pt_regs ,
	unsigned long, int);
	do_signal32(oldset, regs, orig_i0,
	cookie.restart_syscall);
	return;
	}
	#endif

	signr = get_signal_to_deliver(&info, &ka, regs, &cookie);
	if (signr > 0) {
	if (cookie.restart_syscall)
	syscall_restart(orig_i0, regs, &ka.sa);
	handle_signal(signr, &ka, &info, oldset, regs);

	/* a signal was successfully delivered; the saved
	* sigmask will have been stored in the signal frame,
	* and will be restored by sigreturn, so we can simply
	* clear the TIF_RESTORE_SIGMASK flag.
	*/
	if (test_thread_flag(TIF_RESTORE_SIGMASK))
	clear_thread_flag(TIF_RESTORE_SIGMASK);
	return;
	}
	if (cookie.restart_syscall &&
	(regs->u_regs[UREG_I0] == ERESTARTNOHAND \|\|
	regs->u_regs[UREG_I0] == ERESTARTSYS \|\|
	regs->u_regs[UREG_I0] == ERESTARTNOINTR)) {
	/* replay the system call when we are done */
	regs->u_regs[UREG_I0] = cookie.orig_i0;
	regs->tpc -= 4;
	regs->tnpc -= 4;
	}
	if (cookie.restart_syscall &&
	regs->u_regs[UREG_I0] == ERESTART_RESTARTBLOCK) {
	regs->u_regs[UREG_G1] = __NR_restart_syscall;
	regs->tpc -= 4;
	regs->tnpc -= 4;
	}

	/* if there's no signal to deliver, we just 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);
	}
	}

	void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0, int restart_syscall,
	unsigned long thread_info_flags)
	{
	if (thread_info_flags & (_TIF_SIGPENDING \| _TIF_RESTORE_SIGMASK))
	do_signal(regs, orig_i0, restart_syscall);
	}

	void ptrace_signal_deliver(struct pt_regs regs, void cookie)
	{
	struct signal_deliver_cookie *cp = cookie;

	if (cp->restart_syscall &&
	(regs->u_regs[UREG_I0] == ERESTARTNOHAND \|\|
	regs->u_regs[UREG_I0] == ERESTARTSYS \|\|
	regs->u_regs[UREG_I0] == ERESTARTNOINTR)) {
	/* replay the system call when we are done */
	regs->u_regs[UREG_I0] = cp->orig_i0;
	regs->tpc -= 4;
	regs->tnpc -= 4;
	cp->restart_syscall = 0;
	}
	if (cp->restart_syscall &&
	regs->u_regs[UREG_I0] == ERESTART_RESTARTBLOCK) {
	regs->u_regs[UREG_G1] = __NR_restart_syscall;
	regs->tpc -= 4;
	regs->tnpc -= 4;
	cp->restart_syscall = 0;
	}
	}