arch/frv/kernel/signal.c - LeafOS-Devices/android_kernel_samsung_exynos9820 - Gitiles

 /* signal.c: FRV specific bits of signal handling
  *
  * Copyright (C) 2003-5 Red Hat, Inc. All Rights Reserved.
  * Written by David Howells (dhowells@redhat.com)
  * - Derived from arch/m68k/kernel/signal.c
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
  * as published by the Free Software Foundation; either version
  * 2 of the License, or (at your option) any later version.
  */

 #include <linux/sched.h>
 #include <linux/mm.h>
 #include <linux/smp.h>
 #include <linux/kernel.h>
 #include <linux/signal.h>
 #include <linux/errno.h>
 #include <linux/wait.h>
 #include <linux/ptrace.h>
 #include <linux/unistd.h>
 #include <linux/personality.h>
 #include <linux/tracehook.h>
 #include <asm/ucontext.h>
 #include <asm/uaccess.h>
 #include <asm/cacheflush.h>

 #define DEBUG_SIG 0

 struct fdpic_func_descriptor {
 	unsigned long	text;
 	unsigned long	GOT;
 };

 /*
  * Do a signal return; undo the signal stack.
  */

 struct sigframe
 {
 	__sigrestore_t pretcode;
 	int sig;
 	struct sigcontext sc;
 	unsigned long extramask[_NSIG_WORDS-1];
 	uint32_t retcode[2];
 };

 struct rt_sigframe
 {
 	__sigrestore_t pretcode;
 	int sig;
 	struct siginfo __user *pinfo;
 	void __user *puc;
 	struct siginfo info;
 	struct ucontext uc;
 	uint32_t retcode[2];
 };

 static int restore_sigcontext(struct sigcontext __user *sc, int *_gr8)
 {
 	struct user_context *user = current->thread.user;
 	unsigned long tbr, psr;

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

 	tbr = user->i.tbr;
 	psr = user->i.psr;
 	if (copy_from_user(user, &sc->sc_context, sizeof(sc->sc_context)))
 		goto badframe;
 	user->i.tbr = tbr;
 	user->i.psr = psr;

 	restore_user_regs(user);

 	user->i.syscallno = -1;		/* disable syscall checks */

 	*_gr8 = user->i.gr[8];
 	return 0;

  badframe:
 	return 1;
 }

 asmlinkage int sys_sigreturn(void)
 {
 	struct sigframe __user *frame = (struct sigframe __user *) __frame->sp;
 	sigset_t set;
 	int gr8;

 	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
 		goto badframe;
 	if (__get_user(set.sig[0], &frame->sc.sc_oldmask))
 		goto badframe;

 	if (_NSIG_WORDS > 1 &&
 	    __copy_from_user(&set.sig[1], &frame->extramask, sizeof(frame->extramask)))
 		goto badframe;

 	set_current_blocked(&set);

 	if (restore_sigcontext(&frame->sc, &gr8))
 		goto badframe;
 	return gr8;

  badframe:
 	force_sig(SIGSEGV, current);
 	return 0;
 }

 asmlinkage int sys_rt_sigreturn(void)
 {
 	struct rt_sigframe __user *frame = (struct rt_sigframe __user *) __frame->sp;
 	sigset_t set;
 	int gr8;

 	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
 		goto badframe;
 	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
 		goto badframe;

 	set_current_blocked(&set);

 	if (restore_sigcontext(&frame->uc.uc_mcontext, &gr8))
 		goto badframe;

 	if (restore_altstack(&frame->uc.uc_stack))
 		goto badframe;

 	return gr8;

 badframe:
 	force_sig(SIGSEGV, current);
 	return 0;
 }

 /*
  * Set up a signal frame
  */
 static int setup_sigcontext(struct sigcontext __user *sc, unsigned long mask)
 {
 	save_user_regs(current->thread.user);

 	if (copy_to_user(&sc->sc_context, current->thread.user, sizeof(sc->sc_context)) != 0)
 		goto badframe;

 	/* non-iBCS2 extensions.. */
 	if (__put_user(mask, &sc->sc_oldmask) < 0)
 		goto badframe;

 	return 0;

  badframe:
 	return 1;
 }

 /*****************************************************************************/
 /*
  * Determine which stack to use..
  */
 static inline void __user *get_sigframe(struct ksignal *ksig,
 					size_t frame_size)
 {
 	unsigned long sp = sigsp(__frame->sp, ksig);

 	return (void __user *) ((sp - frame_size) & ~7UL);

 } /* end get_sigframe() */

 /*****************************************************************************/
 /*
  *
  */
 static int setup_frame(struct ksignal *ksig, sigset_t *set)
 {
 	struct sigframe __user *frame;
 	int rsig, sig = ksig->sig;

 	set_fs(USER_DS);

 	frame = get_sigframe(ksig, sizeof(*frame));

 	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
 		return -EFAULT;

 	rsig = sig;
 	if (sig < 32 &&
 	    __current_thread_info->exec_domain &&
 	    __current_thread_info->exec_domain->signal_invmap)
 		rsig = __current_thread_info->exec_domain->signal_invmap[sig];

 	if (__put_user(rsig, &frame->sig) < 0)
 		return -EFAULT;

 	if (setup_sigcontext(&frame->sc, set->sig[0]))
 		return -EFAULT;

 	if (_NSIG_WORDS > 1) {
 		if (__copy_to_user(frame->extramask, &set->sig[1],
 				   sizeof(frame->extramask)))
 			return -EFAULT;
 	}

 	/* Set up to return from userspace.  If provided, use a stub
 	 * already in userspace.  */
 	if (ksig->ka.sa.sa_flags & SA_RESTORER) {
 		if (__put_user(ksig->ka.sa.sa_restorer, &frame->pretcode) < 0)
 			return -EFAULT;
 	}
 	else {
 		/* Set up the following code on the stack:
 		 *	setlos	#__NR_sigreturn,gr7
 		 *	tira	gr0,0
 		 */
 		if (__put_user((__sigrestore_t)frame->retcode, &frame->pretcode) ||
 		    __put_user(0x8efc0000|__NR_sigreturn, &frame->retcode[0]) ||
 		    __put_user(0xc0700000, &frame->retcode[1]))
 			return -EFAULT;

 		flush_icache_range((unsigned long) frame->retcode,
 				   (unsigned long) (frame->retcode + 2));
 	}

 	/* Set up registers for the signal handler */
 	if (current->personality & FDPIC_FUNCPTRS) {
 		struct fdpic_func_descriptor __user *funcptr =
 			(struct fdpic_func_descriptor __user *) ksig->ka.sa.sa_handler;
 		struct fdpic_func_descriptor desc;
 		if (copy_from_user(&desc, funcptr, sizeof(desc)))
 			return -EFAULT;
 		__frame->pc = desc.text;
 		__frame->gr15 = desc.GOT;
 	} else {
 		__frame->pc   = (unsigned long) ksig->ka.sa.sa_handler;
 		__frame->gr15 = 0;
 	}

 	__frame->sp   = (unsigned long) frame;
 	__frame->lr   = (unsigned long) &frame->retcode;
 	__frame->gr8  = sig;

 #if DEBUG_SIG
 	printk("SIG deliver %d (%s:%d): sp=%p pc=%lx ra=%p\n",
 	       sig, current->comm, current->pid, frame, __frame->pc,
 	       frame->pretcode);
 #endif

 	return 0;
 } /* end setup_frame() */

 /*****************************************************************************/
 /*
  *
  */
 static int setup_rt_frame(struct ksignal *ksig, sigset_t *set)
 {
 	struct rt_sigframe __user *frame;
 	int rsig, sig = ksig->sig;

 	set_fs(USER_DS);

 	frame = get_sigframe(ksig, sizeof(*frame));

 	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
 		return -EFAULT;

 	rsig = sig;
 	if (sig < 32 &&
 	    __current_thread_info->exec_domain &&
 	    __current_thread_info->exec_domain->signal_invmap)
 		rsig = __current_thread_info->exec_domain->signal_invmap[sig];

 	if (__put_user(rsig,		&frame->sig) ||
 	    __put_user(&frame->info,	&frame->pinfo) ||
 	    __put_user(&frame->uc,	&frame->puc))
 		return -EFAULT;

 	if (copy_siginfo_to_user(&frame->info, &ksig->info))
 		return -EFAULT;

 	/* Create the ucontext.  */
 	if (__put_user(0, &frame->uc.uc_flags) ||
 	    __put_user(NULL, &frame->uc.uc_link) ||
 	    __save_altstack(&frame->uc.uc_stack, __frame->sp))
 		return -EFAULT;

 	if (setup_sigcontext(&frame->uc.uc_mcontext, set->sig[0]))
 		return -EFAULT;

 	if (__copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)))
 		return -EFAULT;

 	/* Set up to return from userspace.  If provided, use a stub
 	 * already in userspace.  */
 	if (ksig->ka.sa.sa_flags & SA_RESTORER) {
 		if (__put_user(ksig->ka.sa.sa_restorer, &frame->pretcode))
 			return -EFAULT;
 	}
 	else {
 		/* Set up the following code on the stack:
 		 *	setlos	#__NR_sigreturn,gr7
 		 *	tira	gr0,0
 		 */
 		if (__put_user((__sigrestore_t)frame->retcode, &frame->pretcode) ||
 		    __put_user(0x8efc0000|__NR_rt_sigreturn, &frame->retcode[0]) ||
 		    __put_user(0xc0700000, &frame->retcode[1]))
 			return -EFAULT;

 		flush_icache_range((unsigned long) frame->retcode,
 				   (unsigned long) (frame->retcode + 2));
 	}

 	/* Set up registers for signal handler */
 	if (current->personality & FDPIC_FUNCPTRS) {
 		struct fdpic_func_descriptor __user *funcptr =
 			(struct fdpic_func_descriptor __user *) ksig->ka.sa.sa_handler;
 		struct fdpic_func_descriptor desc;
 		if (copy_from_user(&desc, funcptr, sizeof(desc)))
 			return -EFAULT;
 		__frame->pc = desc.text;
 		__frame->gr15 = desc.GOT;
 	} else {
 		__frame->pc   = (unsigned long) ksig->ka.sa.sa_handler;
 		__frame->gr15 = 0;
 	}

 	__frame->sp  = (unsigned long) frame;
 	__frame->lr  = (unsigned long) &frame->retcode;
 	__frame->gr8 = sig;
 	__frame->gr9 = (unsigned long) &frame->info;

 #if DEBUG_SIG
 	printk("SIG deliver %d (%s:%d): sp=%p pc=%lx ra=%p\n",
 	       sig, current->comm, current->pid, frame, __frame->pc,
 	       frame->pretcode);
 #endif
 	return 0;

 } /* end setup_rt_frame() */

 /*****************************************************************************/
 /*
  * OK, we're invoking a handler
  */
 static void handle_signal(struct ksignal *ksig)
 {
 	sigset_t *oldset = sigmask_to_save();
 	int ret;

 	/* Are we from a system call? */
 	if (__frame->syscallno != -1) {
 		/* If so, check system call restarting.. */
 		switch (__frame->gr8) {
 		case -ERESTART_RESTARTBLOCK:
 		case -ERESTARTNOHAND:
 			__frame->gr8 = -EINTR;
 			break;

 		case -ERESTARTSYS:
 			if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
 				__frame->gr8 = -EINTR;
 				break;
 			}

 			/* fallthrough */
 		case -ERESTARTNOINTR:
 			__frame->gr8 = __frame->orig_gr8;
 			__frame->pc -= 4;
 		}
 		__frame->syscallno = -1;
 	}

 	/* Set up the stack frame */
 	if (ksig->ka.sa.sa_flags & SA_SIGINFO)
 		ret = setup_rt_frame(ksig, oldset);
 	else
 		ret = setup_frame(ksig, oldset);

 	signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP));
 } /* end handle_signal() */

 /*****************************************************************************/
 /*
  * 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(void)
 {
 	struct ksignal ksig;

 	if (get_signal(&ksig)) {
 		handle_signal(&ksig);
 		return;
 	}

 	/* Did we come from a system call? */
 	if (__frame->syscallno != -1) {
 		/* Restart the system call - no handlers present */
 		switch (__frame->gr8) {
 		case -ERESTARTNOHAND:
 		case -ERESTARTSYS:
 		case -ERESTARTNOINTR:
 			__frame->gr8 = __frame->orig_gr8;
 			__frame->pc -= 4;
 			break;

 		case -ERESTART_RESTARTBLOCK:
 			__frame->gr7 = __NR_restart_syscall;
 			__frame->pc -= 4;
 			break;
 		}
 		__frame->syscallno = -1;
 	}

 	/* if there's no signal to deliver, we just put the saved sigmask
 	 * back */
 	restore_saved_sigmask();
 } /* end do_signal() */

 /*****************************************************************************/
 /*
  * notification of userspace execution resumption
  * - triggered by the TIF_WORK_MASK flags
  */
 asmlinkage void do_notify_resume(__u32 thread_info_flags)
 {
 	/* pending single-step? */
 	if (thread_info_flags & _TIF_SINGLESTEP)
 		clear_thread_flag(TIF_SINGLESTEP);

 	/* deal with pending signal delivery */
 	if (thread_info_flags & _TIF_SIGPENDING)
 		do_signal();

 	/* deal with notification on about to resume userspace execution */
 	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
 		clear_thread_flag(TIF_NOTIFY_RESUME);
 		tracehook_notify_resume(__frame);
 	}

 } /* end do_notify_resume() */
	/* signal.c: FRV specific bits of signal handling
	*
	* Copyright (C) 2003-5 Red Hat, Inc. All Rights Reserved.
	* Written by David Howells (dhowells@redhat.com)
	* - Derived from arch/m68k/kernel/signal.c
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public License
	* as published by the Free Software Foundation; either version
	* 2 of the License, or (at your option) any later version.
	*/

	#include <linux/sched.h>
	#include <linux/mm.h>
	#include <linux/smp.h>
	#include <linux/kernel.h>
	#include <linux/signal.h>
	#include <linux/errno.h>
	#include <linux/wait.h>
	#include <linux/ptrace.h>
	#include <linux/unistd.h>
	#include <linux/personality.h>
	#include <linux/tracehook.h>
	#include <asm/ucontext.h>
	#include <asm/uaccess.h>
	#include <asm/cacheflush.h>

	#define DEBUG_SIG 0

	struct fdpic_func_descriptor {
	unsigned long text;
	unsigned long GOT;
	};

	/*
	* Do a signal return; undo the signal stack.
	*/

	struct sigframe
	{
	__sigrestore_t pretcode;
	int sig;
	struct sigcontext sc;
	unsigned long extramask[_NSIG_WORDS-1];
	uint32_t retcode[2];
	};

	struct rt_sigframe
	{
	__sigrestore_t pretcode;
	int sig;
	struct siginfo __user *pinfo;
	void __user *puc;
	struct siginfo info;
	struct ucontext uc;
	uint32_t retcode[2];
	};

	static int restore_sigcontext(struct sigcontext __user sc, int _gr8)
	{
	struct user_context *user = current->thread.user;
	unsigned long tbr, psr;

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

	tbr = user->i.tbr;
	psr = user->i.psr;
	if (copy_from_user(user, &sc->sc_context, sizeof(sc->sc_context)))
	goto badframe;
	user->i.tbr = tbr;
	user->i.psr = psr;

	restore_user_regs(user);

	user->i.syscallno = -1; /* disable syscall checks */

	*_gr8 = user->i.gr[8];
	return 0;

	badframe:
	return 1;
	}

	asmlinkage int sys_sigreturn(void)
	{
	struct sigframe __user frame = (struct sigframe __user ) __frame->sp;
	sigset_t set;
	int gr8;

	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
	goto badframe;
	if (__get_user(set.sig[0], &frame->sc.sc_oldmask))
	goto badframe;

	if (_NSIG_WORDS > 1 &&
	__copy_from_user(&set.sig[1], &frame->extramask, sizeof(frame->extramask)))
	goto badframe;

	set_current_blocked(&set);

	if (restore_sigcontext(&frame->sc, &gr8))
	goto badframe;
	return gr8;

	badframe:
	force_sig(SIGSEGV, current);
	return 0;
	}

	asmlinkage int sys_rt_sigreturn(void)
	{
	struct rt_sigframe __user frame = (struct rt_sigframe __user ) __frame->sp;
	sigset_t set;
	int gr8;

	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
	goto badframe;
	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
	goto badframe;

	set_current_blocked(&set);

	if (restore_sigcontext(&frame->uc.uc_mcontext, &gr8))
	goto badframe;

	if (restore_altstack(&frame->uc.uc_stack))
	goto badframe;

	return gr8;

	badframe:
	force_sig(SIGSEGV, current);
	return 0;
	}

	/*
	* Set up a signal frame
	*/
	static int setup_sigcontext(struct sigcontext __user *sc, unsigned long mask)
	{
	save_user_regs(current->thread.user);

	if (copy_to_user(&sc->sc_context, current->thread.user, sizeof(sc->sc_context)) != 0)
	goto badframe;

	/* non-iBCS2 extensions.. */
	if (__put_user(mask, &sc->sc_oldmask) < 0)
	goto badframe;

	return 0;

	badframe:
	return 1;
	}

	/*****************************************************************************/
	/*
	* Determine which stack to use..
	*/
	static inline void __user get_sigframe(struct ksignal ksig,
	size_t frame_size)
	{
	unsigned long sp = sigsp(__frame->sp, ksig);

	return (void __user *) ((sp - frame_size) & ~7UL);

	} /* end get_sigframe() */

	/*****************************************************************************/
	/*
	*
	*/
	static int setup_frame(struct ksignal ksig, sigset_t set)
	{
	struct sigframe __user *frame;
	int rsig, sig = ksig->sig;

	set_fs(USER_DS);

	frame = get_sigframe(ksig, sizeof(*frame));

	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
	return -EFAULT;

	rsig = sig;
	if (sig < 32 &&
	__current_thread_info->exec_domain &&
	__current_thread_info->exec_domain->signal_invmap)
	rsig = __current_thread_info->exec_domain->signal_invmap[sig];

	if (__put_user(rsig, &frame->sig) < 0)
	return -EFAULT;

	if (setup_sigcontext(&frame->sc, set->sig[0]))
	return -EFAULT;

	if (_NSIG_WORDS > 1) {
	if (__copy_to_user(frame->extramask, &set->sig[1],
	sizeof(frame->extramask)))
	return -EFAULT;
	}

	/* Set up to return from userspace. If provided, use a stub
	* already in userspace. */
	if (ksig->ka.sa.sa_flags & SA_RESTORER) {
	if (__put_user(ksig->ka.sa.sa_restorer, &frame->pretcode) < 0)
	return -EFAULT;
	}
	else {
	/* Set up the following code on the stack:
	* setlos #__NR_sigreturn,gr7
	* tira gr0,0
	*/
	if (__put_user((__sigrestore_t)frame->retcode, &frame->pretcode) \|\|
	__put_user(0x8efc0000\|__NR_sigreturn, &frame->retcode[0]) \|\|
	__put_user(0xc0700000, &frame->retcode[1]))
	return -EFAULT;

	flush_icache_range((unsigned long) frame->retcode,
	(unsigned long) (frame->retcode + 2));
	}

	/* Set up registers for the signal handler */
	if (current->personality & FDPIC_FUNCPTRS) {
	struct fdpic_func_descriptor __user *funcptr =
	(struct fdpic_func_descriptor __user *) ksig->ka.sa.sa_handler;
	struct fdpic_func_descriptor desc;
	if (copy_from_user(&desc, funcptr, sizeof(desc)))
	return -EFAULT;
	__frame->pc = desc.text;
	__frame->gr15 = desc.GOT;
	} else {
	__frame->pc = (unsigned long) ksig->ka.sa.sa_handler;
	__frame->gr15 = 0;
	}

	__frame->sp = (unsigned long) frame;
	__frame->lr = (unsigned long) &frame->retcode;
	__frame->gr8 = sig;

	#if DEBUG_SIG
	printk("SIG deliver %d (%s:%d): sp=%p pc=%lx ra=%p\n",
	sig, current->comm, current->pid, frame, __frame->pc,
	frame->pretcode);
	#endif

	return 0;
	} /* end setup_frame() */

	/*****************************************************************************/
	/*
	*
	*/
	static int setup_rt_frame(struct ksignal ksig, sigset_t set)
	{
	struct rt_sigframe __user *frame;
	int rsig, sig = ksig->sig;

	set_fs(USER_DS);

	frame = get_sigframe(ksig, sizeof(*frame));

	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
	return -EFAULT;

	rsig = sig;
	if (sig < 32 &&
	__current_thread_info->exec_domain &&
	__current_thread_info->exec_domain->signal_invmap)
	rsig = __current_thread_info->exec_domain->signal_invmap[sig];

	if (__put_user(rsig, &frame->sig) \|\|
	__put_user(&frame->info, &frame->pinfo) \|\|
	__put_user(&frame->uc, &frame->puc))
	return -EFAULT;

	if (copy_siginfo_to_user(&frame->info, &ksig->info))
	return -EFAULT;

	/* Create the ucontext. */
	if (__put_user(0, &frame->uc.uc_flags) \|\|
	__put_user(NULL, &frame->uc.uc_link) \|\|
	__save_altstack(&frame->uc.uc_stack, __frame->sp))
	return -EFAULT;

	if (setup_sigcontext(&frame->uc.uc_mcontext, set->sig[0]))
	return -EFAULT;

	if (__copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)))
	return -EFAULT;

	/* Set up to return from userspace. If provided, use a stub
	* already in userspace. */
	if (ksig->ka.sa.sa_flags & SA_RESTORER) {
	if (__put_user(ksig->ka.sa.sa_restorer, &frame->pretcode))
	return -EFAULT;
	}
	else {
	/* Set up the following code on the stack:
	* setlos #__NR_sigreturn,gr7
	* tira gr0,0
	*/
	if (__put_user((__sigrestore_t)frame->retcode, &frame->pretcode) \|\|
	__put_user(0x8efc0000\|__NR_rt_sigreturn, &frame->retcode[0]) \|\|
	__put_user(0xc0700000, &frame->retcode[1]))
	return -EFAULT;

	flush_icache_range((unsigned long) frame->retcode,
	(unsigned long) (frame->retcode + 2));
	}

	/* Set up registers for signal handler */
	if (current->personality & FDPIC_FUNCPTRS) {
	struct fdpic_func_descriptor __user *funcptr =
	(struct fdpic_func_descriptor __user *) ksig->ka.sa.sa_handler;
	struct fdpic_func_descriptor desc;
	if (copy_from_user(&desc, funcptr, sizeof(desc)))
	return -EFAULT;
	__frame->pc = desc.text;
	__frame->gr15 = desc.GOT;
	} else {
	__frame->pc = (unsigned long) ksig->ka.sa.sa_handler;
	__frame->gr15 = 0;
	}

	__frame->sp = (unsigned long) frame;
	__frame->lr = (unsigned long) &frame->retcode;
	__frame->gr8 = sig;
	__frame->gr9 = (unsigned long) &frame->info;

	#if DEBUG_SIG
	printk("SIG deliver %d (%s:%d): sp=%p pc=%lx ra=%p\n",
	sig, current->comm, current->pid, frame, __frame->pc,
	frame->pretcode);
	#endif
	return 0;

	} /* end setup_rt_frame() */

	/*****************************************************************************/
	/*
	* OK, we're invoking a handler
	*/
	static void handle_signal(struct ksignal *ksig)
	{
	sigset_t *oldset = sigmask_to_save();
	int ret;

	/* Are we from a system call? */
	if (__frame->syscallno != -1) {
	/* If so, check system call restarting.. */
	switch (__frame->gr8) {
	case -ERESTART_RESTARTBLOCK:
	case -ERESTARTNOHAND:
	__frame->gr8 = -EINTR;
	break;

	case -ERESTARTSYS:
	if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
	__frame->gr8 = -EINTR;
	break;
	}

	/* fallthrough */
	case -ERESTARTNOINTR:
	__frame->gr8 = __frame->orig_gr8;
	__frame->pc -= 4;
	}
	__frame->syscallno = -1;
	}

	/* Set up the stack frame */
	if (ksig->ka.sa.sa_flags & SA_SIGINFO)
	ret = setup_rt_frame(ksig, oldset);
	else
	ret = setup_frame(ksig, oldset);

	signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP));
	} /* end handle_signal() */

	/*****************************************************************************/
	/*
	* 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(void)
	{
	struct ksignal ksig;

	if (get_signal(&ksig)) {
	handle_signal(&ksig);
	return;
	}

	/* Did we come from a system call? */
	if (__frame->syscallno != -1) {
	/* Restart the system call - no handlers present */
	switch (__frame->gr8) {
	case -ERESTARTNOHAND:
	case -ERESTARTSYS:
	case -ERESTARTNOINTR:
	__frame->gr8 = __frame->orig_gr8;
	__frame->pc -= 4;
	break;

	case -ERESTART_RESTARTBLOCK:
	__frame->gr7 = __NR_restart_syscall;
	__frame->pc -= 4;
	break;
	}
	__frame->syscallno = -1;
	}

	/* if there's no signal to deliver, we just put the saved sigmask
	* back */
	restore_saved_sigmask();
	} /* end do_signal() */

	/*****************************************************************************/
	/*
	* notification of userspace execution resumption
	* - triggered by the TIF_WORK_MASK flags
	*/
	asmlinkage void do_notify_resume(__u32 thread_info_flags)
	{
	/* pending single-step? */
	if (thread_info_flags & _TIF_SINGLESTEP)
	clear_thread_flag(TIF_SINGLESTEP);

	/* deal with pending signal delivery */
	if (thread_info_flags & _TIF_SIGPENDING)
	do_signal();

	/* deal with notification on about to resume userspace execution */
	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
	clear_thread_flag(TIF_NOTIFY_RESUME);
	tracehook_notify_resume(__frame);
	}

	} /* end do_notify_resume() */