arch/x86_64/kernel/signal.c - LeafOS-Devices/android_kernel_samsung_universal7904 - Gitiles

 /*
  *  linux/arch/x86_64/kernel/signal.c
  *
  *  Copyright (C) 1991, 1992  Linus Torvalds
  *  Copyright (C) 2000, 2001, 2002 Andi Kleen SuSE Labs
  *
  *  1997-11-28  Modified for POSIX.1b signals by Richard Henderson
  *  2000-06-20  Pentium III FXSR, SSE support by Gareth Hughes
  *  2000-2002   x86-64 support by Andi Kleen
  *
  *  $Id: signal.c,v 1.18 2001/10/17 22:30:37 ak Exp $
  */

 #include <linux/sched.h>
 #include <linux/mm.h>
 #include <linux/smp.h>
 #include <linux/smp_lock.h>
 #include <linux/kernel.h>
 #include <linux/signal.h>
 #include <linux/errno.h>
 #include <linux/wait.h>
 #include <linux/ptrace.h>
 #include <linux/unistd.h>
 #include <linux/stddef.h>
 #include <linux/personality.h>
 #include <linux/compiler.h>
 #include <asm/ucontext.h>
 #include <asm/uaccess.h>
 #include <asm/i387.h>
 #include <asm/proto.h>

 /* #define DEBUG_SIG 1 */

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

 void ia32_setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
                sigset_t *set, struct pt_regs * regs);
 void ia32_setup_frame(int sig, struct k_sigaction *ka,
             sigset_t *set, struct pt_regs * regs);

 asmlinkage long
 sys_rt_sigsuspend(sigset_t __user *unewset, size_t sigsetsize, 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);
 #ifdef DEBUG_SIG
 	printk("rt_sigsuspend savset(%lx) newset(%lx) regs(%p) rip(%lx)\n",
 		saveset, newset, regs, regs->rip);
 #endif
 	regs->rax = -EINTR;
 	while (1) {
 		current->state = TASK_INTERRUPTIBLE;
 		schedule();
 		if (do_signal(regs, &saveset))
 			return -EINTR;
 	}
 }

 asmlinkage long
 sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
 		struct pt_regs *regs)
 {
 	return do_sigaltstack(uss, uoss, regs->rsp);
 }


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

 struct rt_sigframe
 {
 	char *pretcode;
 	struct ucontext uc;
 	struct siginfo info;
 };

 static int
 restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, unsigned long *prax)
 {
 	unsigned int err = 0;

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

 #define COPY(x)		err |= __get_user(regs->x, &sc->x)

 	COPY(rdi); COPY(rsi); COPY(rbp); COPY(rsp); COPY(rbx);
 	COPY(rdx); COPY(rcx); COPY(rip);
 	COPY(r8);
 	COPY(r9);
 	COPY(r10);
 	COPY(r11);
 	COPY(r12);
 	COPY(r13);
 	COPY(r14);
 	COPY(r15);

 	{
 		unsigned int tmpflags;
 		err |= __get_user(tmpflags, &sc->eflags);
 		regs->eflags = (regs->eflags & ~0x40DD5) | (tmpflags & 0x40DD5);
 		regs->orig_rax = -1;		/* disable syscall checks */
 	}

 	{
 		struct _fpstate __user * buf;
 		err |= __get_user(buf, &sc->fpstate);

 		if (buf) {
 			if (!access_ok(VERIFY_READ, buf, sizeof(*buf)))
 				goto badframe;
 			err |= restore_i387(buf);
 		} else {
 			struct task_struct *me = current;
 			if (used_math()) {
 				clear_fpu(me);
 				clear_used_math();
 			}
 		}
 	}

 	err |= __get_user(*prax, &sc->rax);
 	return err;

 badframe:
 	return 1;
 }

 asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
 {
 	struct rt_sigframe __user *frame;
 	sigset_t set;
 	unsigned long eax;

 	frame = (struct rt_sigframe __user *)(regs->rsp - 8);
 	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, &eax))
 		goto badframe;

 #ifdef DEBUG_SIG
 	printk("%d sigreturn rip:%lx rsp:%lx frame:%p rax:%lx\n",current->pid,regs.rip,regs.rsp,frame,eax);
 #endif

 	if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->rsp) == -EFAULT)
 		goto badframe;

 	return eax;

 badframe:
 	signal_fault(regs,frame,"sigreturn");
 	return 0;
 }

 /*
  * Set up a signal frame.
  */

 static inline int
 setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, unsigned long mask, struct task_struct *me)
 {
 	int err = 0;
 	unsigned long eflags;

 	err |= __put_user(0, &sc->gs);
 	err |= __put_user(0, &sc->fs);

 	err |= __put_user(regs->rdi, &sc->rdi);
 	err |= __put_user(regs->rsi, &sc->rsi);
 	err |= __put_user(regs->rbp, &sc->rbp);
 	err |= __put_user(regs->rsp, &sc->rsp);
 	err |= __put_user(regs->rbx, &sc->rbx);
 	err |= __put_user(regs->rdx, &sc->rdx);
 	err |= __put_user(regs->rcx, &sc->rcx);
 	err |= __put_user(regs->rax, &sc->rax);
 	err |= __put_user(regs->r8, &sc->r8);
 	err |= __put_user(regs->r9, &sc->r9);
 	err |= __put_user(regs->r10, &sc->r10);
 	err |= __put_user(regs->r11, &sc->r11);
 	err |= __put_user(regs->r12, &sc->r12);
 	err |= __put_user(regs->r13, &sc->r13);
 	err |= __put_user(regs->r14, &sc->r14);
 	err |= __put_user(regs->r15, &sc->r15);
 	err |= __put_user(me->thread.trap_no, &sc->trapno);
 	err |= __put_user(me->thread.error_code, &sc->err);
 	err |= __put_user(regs->rip, &sc->rip);
 	eflags = regs->eflags;
 	if (current->ptrace & PT_PTRACED) {
 		eflags &= ~TF_MASK;
 	}
 	err |= __put_user(eflags, &sc->eflags);
 	err |= __put_user(mask, &sc->oldmask);
 	err |= __put_user(me->thread.cr2, &sc->cr2);

 	return err;
 }

 /*
  * Determine which stack to use..
  */

 static void __user *
 get_stack(struct k_sigaction *ka, struct pt_regs *regs, unsigned long size)
 {
 	unsigned long rsp;

 	/* Default to using normal stack - redzone*/
 	rsp = regs->rsp - 128;

 	/* This is the X/Open sanctioned signal stack switching.  */
 	/* RED-PEN: redzone on that stack? */
 	if (ka->sa.sa_flags & SA_ONSTACK) {
 		if (sas_ss_flags(rsp) == 0)
 			rsp = current->sas_ss_sp + current->sas_ss_size;
 	}

 	return (void __user *)round_down(rsp - size, 16);
 }

 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;
 	struct _fpstate __user *fp = NULL;
 	int err = 0;
 	struct task_struct *me = current;

 	if (used_math()) {
 		fp = get_stack(ka, regs, sizeof(struct _fpstate));
 		frame = (void __user *)round_down(
 			(unsigned long)fp - sizeof(struct rt_sigframe), 16) - 8;

 		if (!access_ok(VERIFY_WRITE, fp, sizeof(struct _fpstate)))
 			goto give_sigsegv;

 		if (save_i387(fp) < 0)
 			err |= -1;
 	} else
 		frame = get_stack(ka, regs, sizeof(struct rt_sigframe)) - 8;

 	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
 		goto give_sigsegv;

 	if (ka->sa.sa_flags & SA_SIGINFO) {
 		err |= copy_siginfo_to_user(&frame->info, info);
 		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(me->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
 	err |= __put_user(sas_ss_flags(regs->rsp),
 			  &frame->uc.uc_stack.ss_flags);
 	err |= __put_user(me->sas_ss_size, &frame->uc.uc_stack.ss_size);
 	err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0], me);
 	err |= __put_user(fp, &frame->uc.uc_mcontext.fpstate);
 	if (sizeof(*set) == 16) {
 		__put_user(set->sig[0], &frame->uc.uc_sigmask.sig[0]);
 		__put_user(set->sig[1], &frame->uc.uc_sigmask.sig[1]);
 	} else
 		err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));

 	/* Set up to return from userspace.  If provided, use a stub
 	   already in userspace.  */
 	/* x86-64 should always use SA_RESTORER. */
 	if (ka->sa.sa_flags & SA_RESTORER) {
 		err |= __put_user(ka->sa.sa_restorer, &frame->pretcode);
 	} else {
 		/* could use a vstub here */
 		goto give_sigsegv;
 	}

 	if (err)
 		goto give_sigsegv;

 #ifdef DEBUG_SIG
 	printk("%d old rip %lx old rsp %lx old rax %lx\n", current->pid,regs->rip,regs->rsp,regs->rax);
 #endif

 	/* Set up registers for signal handler */
 	{
 		struct exec_domain *ed = current_thread_info()->exec_domain;
 		if (unlikely(ed && ed->signal_invmap && sig < 32))
 			sig = ed->signal_invmap[sig];
 	}
 	regs->rdi = sig;
 	/* In case the signal handler was declared without prototypes */
 	regs->rax = 0;

 	/* This also works for non SA_SIGINFO handlers because they expect the
 	   next argument after the signal number on the stack. */
 	regs->rsi = (unsigned long)&frame->info;
 	regs->rdx = (unsigned long)&frame->uc;
 	regs->rip = (unsigned long) ka->sa.sa_handler;

 	regs->rsp = (unsigned long)frame;

 	set_fs(USER_DS);
 	if (regs->eflags & TF_MASK) {
 		if ((current->ptrace & (PT_PTRACED | PT_DTRACE)) == (PT_PTRACED | PT_DTRACE)) {
 			ptrace_notify(SIGTRAP);
 		} else {
 			regs->eflags &= ~TF_MASK;
 		}
 	}

 #ifdef DEBUG_SIG
 	printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n",
 		current->comm, current->pid, frame, regs->rip, frame->pretcode);
 #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)
 {
 #ifdef DEBUG_SIG
 	printk("handle_signal pid:%d sig:%lu rip:%lx rsp:%lx regs=%p\n",
 		current->pid, sig,
 		regs->rip, regs->rsp, regs);
 #endif

 	/* Are we from a system call? */
 	if ((long)regs->orig_rax >= 0) {
 		/* If so, check system call restarting.. */
 		switch (regs->rax) {
 		        case -ERESTART_RESTARTBLOCK:
 			case -ERESTARTNOHAND:
 				regs->rax = -EINTR;
 				break;

 			case -ERESTARTSYS:
 				if (!(ka->sa.sa_flags & SA_RESTART)) {
 					regs->rax = -EINTR;
 					break;
 				}
 				/* fallthrough */
 			case -ERESTARTNOINTR:
 				regs->rax = regs->orig_rax;
 				regs->rip -= 2;
 				break;
 		}
 	}

 #ifdef CONFIG_IA32_EMULATION
 	if (test_thread_flag(TIF_IA32)) {
 		if (ka->sa.sa_flags & SA_SIGINFO)
 			ia32_setup_rt_frame(sig, ka, info, oldset, regs);
 		else
 			ia32_setup_frame(sig, ka, oldset, regs);
 	} else
 #endif
 	setup_rt_frame(sig, ka, info, oldset, regs);

 	if (!(ka->sa.sa_flags & SA_NODEFER)) {
 		spin_lock_irq(&current->sighand->siglock);
 		sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
 		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.
  */
 int do_signal(struct pt_regs *regs, sigset_t *oldset)
 {
 	struct k_sigaction ka;
 	siginfo_t info;
 	int signr;

 	/*
 	 * 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 ((regs->cs & 3) != 3)
 		return 1;

 	if (try_to_freeze(0))
 		goto no_signal;

 	if (!oldset)
 		oldset = &current->blocked;

 	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
 	if (signr > 0) {
 		/* Reenable any watchpoints before delivering the
 		 * signal to user space. The processor register will
 		 * have been cleared if the watchpoint triggered
 		 * inside the kernel.
 		 */
 		if (current->thread.debugreg7)
 			asm volatile("movq %0,%%db7"	: : "r" (current->thread.debugreg7));

 		/* Whee!  Actually deliver the signal.  */
 		handle_signal(signr, &info, &ka, oldset, regs);
 		return 1;
 	}

  no_signal:
 	/* Did we come from a system call? */
 	if ((long)regs->orig_rax >= 0) {
 		/* Restart the system call - no handlers present */
 		long res = regs->rax;
 		if (res == -ERESTARTNOHAND ||
 		    res == -ERESTARTSYS ||
 		    res == -ERESTARTNOINTR) {
 			regs->rax = regs->orig_rax;
 			regs->rip -= 2;
 		}
 		if (regs->rax == (unsigned long)-ERESTART_RESTARTBLOCK) {
 			regs->rax = __NR_restart_syscall;
 			regs->rip -= 2;
 		}
 	}
 	return 0;
 }

 void do_notify_resume(struct pt_regs *regs, sigset_t *oldset, __u32 thread_info_flags)
 {
 #ifdef DEBUG_SIG
 	printk("do_notify_resume flags:%x rip:%lx rsp:%lx caller:%lx pending:%lx\n",
 	       thread_info_flags, regs->rip, regs->rsp, __builtin_return_address(0),signal_pending(current));
 #endif

 	/* Pending single-step? */
 	if (thread_info_flags & _TIF_SINGLESTEP) {
 		regs->eflags |= TF_MASK;
 		clear_thread_flag(TIF_SINGLESTEP);
 	}

 	/* deal with pending signal delivery */
 	if (thread_info_flags & _TIF_SIGPENDING)
 		do_signal(regs,oldset);
 }

 void signal_fault(struct pt_regs *regs, void __user *frame, char *where)
 {
 	struct task_struct *me = current;
 	if (exception_trace)
 		printk("%s[%d] bad frame in %s frame:%p rip:%lx rsp:%lx orax:%lx\n",
 	       me->comm,me->pid,where,frame,regs->rip,regs->rsp,regs->orig_rax);

 	force_sig(SIGSEGV, me);
 }
	/*
	* linux/arch/x86_64/kernel/signal.c
	*
	* Copyright (C) 1991, 1992 Linus Torvalds
	* Copyright (C) 2000, 2001, 2002 Andi Kleen SuSE Labs
	*
	* 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
	* 2000-06-20 Pentium III FXSR, SSE support by Gareth Hughes
	* 2000-2002 x86-64 support by Andi Kleen
	*
	* $Id: signal.c,v 1.18 2001/10/17 22:30:37 ak Exp $
	*/

	#include <linux/sched.h>
	#include <linux/mm.h>
	#include <linux/smp.h>
	#include <linux/smp_lock.h>
	#include <linux/kernel.h>
	#include <linux/signal.h>
	#include <linux/errno.h>
	#include <linux/wait.h>
	#include <linux/ptrace.h>
	#include <linux/unistd.h>
	#include <linux/stddef.h>
	#include <linux/personality.h>
	#include <linux/compiler.h>
	#include <asm/ucontext.h>
	#include <asm/uaccess.h>
	#include <asm/i387.h>
	#include <asm/proto.h>

	/* #define DEBUG_SIG 1 */

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

	void ia32_setup_rt_frame(int sig, struct k_sigaction ka, siginfo_t info,
	sigset_t set, struct pt_regs regs);
	void ia32_setup_frame(int sig, struct k_sigaction *ka,
	sigset_t set, struct pt_regs regs);

	asmlinkage long
	sys_rt_sigsuspend(sigset_t __user unewset, size_t sigsetsize, 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);
	#ifdef DEBUG_SIG
	printk("rt_sigsuspend savset(%lx) newset(%lx) regs(%p) rip(%lx)\n",
	saveset, newset, regs, regs->rip);
	#endif
	regs->rax = -EINTR;
	while (1) {
	current->state = TASK_INTERRUPTIBLE;
	schedule();
	if (do_signal(regs, &saveset))
	return -EINTR;
	}
	}

	asmlinkage long
	sys_sigaltstack(const stack_t __user uss, stack_t __user uoss,
	struct pt_regs *regs)
	{
	return do_sigaltstack(uss, uoss, regs->rsp);
	}


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

	struct rt_sigframe
	{
	char *pretcode;
	struct ucontext uc;
	struct siginfo info;
	};

	static int
	restore_sigcontext(struct pt_regs regs, struct sigcontext __user sc, unsigned long *prax)
	{
	unsigned int err = 0;

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

	#define COPY(x) err \|= __get_user(regs->x, &sc->x)

	COPY(rdi); COPY(rsi); COPY(rbp); COPY(rsp); COPY(rbx);
	COPY(rdx); COPY(rcx); COPY(rip);
	COPY(r8);
	COPY(r9);
	COPY(r10);
	COPY(r11);
	COPY(r12);
	COPY(r13);
	COPY(r14);
	COPY(r15);

	{
	unsigned int tmpflags;
	err \|= __get_user(tmpflags, &sc->eflags);
	regs->eflags = (regs->eflags & ~0x40DD5) \| (tmpflags & 0x40DD5);
	regs->orig_rax = -1; /* disable syscall checks */
	}

	{
	struct _fpstate __user * buf;
	err \|= __get_user(buf, &sc->fpstate);

	if (buf) {
	if (!access_ok(VERIFY_READ, buf, sizeof(*buf)))
	goto badframe;
	err \|= restore_i387(buf);
	} else {
	struct task_struct *me = current;
	if (used_math()) {
	clear_fpu(me);
	clear_used_math();
	}
	}
	}

	err \|= __get_user(*prax, &sc->rax);
	return err;

	badframe:
	return 1;
	}

	asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
	{
	struct rt_sigframe __user *frame;
	sigset_t set;
	unsigned long eax;

	frame = (struct rt_sigframe __user *)(regs->rsp - 8);
	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, &eax))
	goto badframe;

	#ifdef DEBUG_SIG
	printk("%d sigreturn rip:%lx rsp:%lx frame:%p rax:%lx\n",current->pid,regs.rip,regs.rsp,frame,eax);
	#endif

	if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->rsp) == -EFAULT)
	goto badframe;

	return eax;

	badframe:
	signal_fault(regs,frame,"sigreturn");
	return 0;
	}

	/*
	* Set up a signal frame.
	*/

	static inline int
	setup_sigcontext(struct sigcontext __user sc, struct pt_regs regs, unsigned long mask, struct task_struct *me)
	{
	int err = 0;
	unsigned long eflags;

	err \|= __put_user(0, &sc->gs);
	err \|= __put_user(0, &sc->fs);

	err \|= __put_user(regs->rdi, &sc->rdi);
	err \|= __put_user(regs->rsi, &sc->rsi);
	err \|= __put_user(regs->rbp, &sc->rbp);
	err \|= __put_user(regs->rsp, &sc->rsp);
	err \|= __put_user(regs->rbx, &sc->rbx);
	err \|= __put_user(regs->rdx, &sc->rdx);
	err \|= __put_user(regs->rcx, &sc->rcx);
	err \|= __put_user(regs->rax, &sc->rax);
	err \|= __put_user(regs->r8, &sc->r8);
	err \|= __put_user(regs->r9, &sc->r9);
	err \|= __put_user(regs->r10, &sc->r10);
	err \|= __put_user(regs->r11, &sc->r11);
	err \|= __put_user(regs->r12, &sc->r12);
	err \|= __put_user(regs->r13, &sc->r13);
	err \|= __put_user(regs->r14, &sc->r14);
	err \|= __put_user(regs->r15, &sc->r15);
	err \|= __put_user(me->thread.trap_no, &sc->trapno);
	err \|= __put_user(me->thread.error_code, &sc->err);
	err \|= __put_user(regs->rip, &sc->rip);
	eflags = regs->eflags;
	if (current->ptrace & PT_PTRACED) {
	eflags &= ~TF_MASK;
	}
	err \|= __put_user(eflags, &sc->eflags);
	err \|= __put_user(mask, &sc->oldmask);
	err \|= __put_user(me->thread.cr2, &sc->cr2);

	return err;
	}

	/*
	* Determine which stack to use..
	*/

	static void __user *
	get_stack(struct k_sigaction ka, struct pt_regs regs, unsigned long size)
	{
	unsigned long rsp;

	/* Default to using normal stack - redzone*/
	rsp = regs->rsp - 128;

	/* This is the X/Open sanctioned signal stack switching. */
	/* RED-PEN: redzone on that stack? */
	if (ka->sa.sa_flags & SA_ONSTACK) {
	if (sas_ss_flags(rsp) == 0)
	rsp = current->sas_ss_sp + current->sas_ss_size;
	}

	return (void __user *)round_down(rsp - size, 16);
	}

	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;
	struct _fpstate __user *fp = NULL;
	int err = 0;
	struct task_struct *me = current;

	if (used_math()) {
	fp = get_stack(ka, regs, sizeof(struct _fpstate));
	frame = (void __user *)round_down(
	(unsigned long)fp - sizeof(struct rt_sigframe), 16) - 8;

	if (!access_ok(VERIFY_WRITE, fp, sizeof(struct _fpstate)))
	goto give_sigsegv;

	if (save_i387(fp) < 0)
	err \|= -1;
	} else
	frame = get_stack(ka, regs, sizeof(struct rt_sigframe)) - 8;

	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
	goto give_sigsegv;

	if (ka->sa.sa_flags & SA_SIGINFO) {
	err \|= copy_siginfo_to_user(&frame->info, info);
	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(me->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
	err \|= __put_user(sas_ss_flags(regs->rsp),
	&frame->uc.uc_stack.ss_flags);
	err \|= __put_user(me->sas_ss_size, &frame->uc.uc_stack.ss_size);
	err \|= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0], me);
	err \|= __put_user(fp, &frame->uc.uc_mcontext.fpstate);
	if (sizeof(*set) == 16) {
	__put_user(set->sig[0], &frame->uc.uc_sigmask.sig[0]);
	__put_user(set->sig[1], &frame->uc.uc_sigmask.sig[1]);
	} else
	err \|= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));

	/* Set up to return from userspace. If provided, use a stub
	already in userspace. */
	/* x86-64 should always use SA_RESTORER. */
	if (ka->sa.sa_flags & SA_RESTORER) {
	err \|= __put_user(ka->sa.sa_restorer, &frame->pretcode);
	} else {
	/* could use a vstub here */
	goto give_sigsegv;
	}

	if (err)
	goto give_sigsegv;

	#ifdef DEBUG_SIG
	printk("%d old rip %lx old rsp %lx old rax %lx\n", current->pid,regs->rip,regs->rsp,regs->rax);
	#endif

	/* Set up registers for signal handler */
	{
	struct exec_domain *ed = current_thread_info()->exec_domain;
	if (unlikely(ed && ed->signal_invmap && sig < 32))
	sig = ed->signal_invmap[sig];
	}
	regs->rdi = sig;
	/* In case the signal handler was declared without prototypes */
	regs->rax = 0;

	/* This also works for non SA_SIGINFO handlers because they expect the
	next argument after the signal number on the stack. */
	regs->rsi = (unsigned long)&frame->info;
	regs->rdx = (unsigned long)&frame->uc;
	regs->rip = (unsigned long) ka->sa.sa_handler;

	regs->rsp = (unsigned long)frame;

	set_fs(USER_DS);
	if (regs->eflags & TF_MASK) {
	if ((current->ptrace & (PT_PTRACED \| PT_DTRACE)) == (PT_PTRACED \| PT_DTRACE)) {
	ptrace_notify(SIGTRAP);
	} else {
	regs->eflags &= ~TF_MASK;
	}
	}

	#ifdef DEBUG_SIG
	printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n",
	current->comm, current->pid, frame, regs->rip, frame->pretcode);
	#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)
	{
	#ifdef DEBUG_SIG
	printk("handle_signal pid:%d sig:%lu rip:%lx rsp:%lx regs=%p\n",
	current->pid, sig,
	regs->rip, regs->rsp, regs);
	#endif

	/* Are we from a system call? */
	if ((long)regs->orig_rax >= 0) {
	/* If so, check system call restarting.. */
	switch (regs->rax) {
	case -ERESTART_RESTARTBLOCK:
	case -ERESTARTNOHAND:
	regs->rax = -EINTR;
	break;

	case -ERESTARTSYS:
	if (!(ka->sa.sa_flags & SA_RESTART)) {
	regs->rax = -EINTR;
	break;
	}
	/* fallthrough */
	case -ERESTARTNOINTR:
	regs->rax = regs->orig_rax;
	regs->rip -= 2;
	break;
	}
	}

	#ifdef CONFIG_IA32_EMULATION
	if (test_thread_flag(TIF_IA32)) {
	if (ka->sa.sa_flags & SA_SIGINFO)
	ia32_setup_rt_frame(sig, ka, info, oldset, regs);
	else
	ia32_setup_frame(sig, ka, oldset, regs);
	} else
	#endif
	setup_rt_frame(sig, ka, info, oldset, regs);

	if (!(ka->sa.sa_flags & SA_NODEFER)) {
	spin_lock_irq(&current->sighand->siglock);
	sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
	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.
	*/
	int do_signal(struct pt_regs regs, sigset_t oldset)
	{
	struct k_sigaction ka;
	siginfo_t info;
	int signr;

	/*
	* 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 ((regs->cs & 3) != 3)
	return 1;

	if (try_to_freeze(0))
	goto no_signal;

	if (!oldset)
	oldset = &current->blocked;

	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
	if (signr > 0) {
	/* Reenable any watchpoints before delivering the
	* signal to user space. The processor register will
	* have been cleared if the watchpoint triggered
	* inside the kernel.
	*/
	if (current->thread.debugreg7)
	asm volatile("movq %0,%%db7" : : "r" (current->thread.debugreg7));

	/* Whee! Actually deliver the signal. */
	handle_signal(signr, &info, &ka, oldset, regs);
	return 1;
	}

	no_signal:
	/* Did we come from a system call? */
	if ((long)regs->orig_rax >= 0) {
	/* Restart the system call - no handlers present */
	long res = regs->rax;
	if (res == -ERESTARTNOHAND \|\|
	res == -ERESTARTSYS \|\|
	res == -ERESTARTNOINTR) {
	regs->rax = regs->orig_rax;
	regs->rip -= 2;
	}
	if (regs->rax == (unsigned long)-ERESTART_RESTARTBLOCK) {
	regs->rax = __NR_restart_syscall;
	regs->rip -= 2;
	}
	}
	return 0;
	}

	void do_notify_resume(struct pt_regs regs, sigset_t oldset, __u32 thread_info_flags)
	{
	#ifdef DEBUG_SIG
	printk("do_notify_resume flags:%x rip:%lx rsp:%lx caller:%lx pending:%lx\n",
	thread_info_flags, regs->rip, regs->rsp, __builtin_return_address(0),signal_pending(current));
	#endif

	/* Pending single-step? */
	if (thread_info_flags & _TIF_SINGLESTEP) {
	regs->eflags \|= TF_MASK;
	clear_thread_flag(TIF_SINGLESTEP);
	}

	/* deal with pending signal delivery */
	if (thread_info_flags & _TIF_SIGPENDING)
	do_signal(regs,oldset);
	}

	void signal_fault(struct pt_regs regs, void __user frame, char *where)
	{
	struct task_struct *me = current;
	if (exception_trace)
	printk("%s[%d] bad frame in %s frame:%p rip:%lx rsp:%lx orax:%lx\n",
	me->comm,me->pid,where,frame,regs->rip,regs->rsp,regs->orig_rax);

	force_sig(SIGSEGV, me);
	}