[mirror_ubuntu-artful-kernel.git] / arch / x86_64 / kernel / signal.c

/*
 *  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>
#include <asm/ia32_unistd.h>

/* #define DEBUG_SIG 1 */

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

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

	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);
	err |= __put_user(regs->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 int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
			   sigset_t *set, struct pt_regs * regs)
{
	struct rt_sigframe __user *frame;
	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);
	regs->eflags &= ~TF_MASK;
	if (test_thread_flag(TIF_SINGLESTEP))
		ptrace_notify(SIGTRAP);
#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 1;

give_sigsegv:
	force_sigsegv(sig, current);
	return 0;
}

/*
 * OK, we're invoking a handler
 */	

static int
handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
		sigset_t *oldset, struct pt_regs *regs)
{
	int ret;

#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;
		}
	}

	/*
	 * If TF is set due to a debugger (PT_DTRACE), clear the TF
	 * flag so that register information in the sigcontext is
	 * correct.
	 */
	if (unlikely(regs->eflags & TF_MASK)) {
		if (likely(current->ptrace & PT_DTRACE)) {
			current->ptrace &= ~PT_DTRACE;
			regs->eflags &= ~TF_MASK;
		}
	}

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

	if (ret && !(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);
	}

	return ret;
}

/*
 * 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)
			set_debugreg(current->thread.debugreg7, 7);

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

 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 = test_thread_flag(TIF_IA32) ?
					__NR_ia32_restart_syscall :
					__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); 
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/arch/x86_64/kernel/signal.c
	3	*
	4	* Copyright (C) 1991, 1992 Linus Torvalds
	5	* Copyright (C) 2000, 2001, 2002 Andi Kleen SuSE Labs
	6	*
	7	* 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
	8	* 2000-06-20 Pentium III FXSR, SSE support by Gareth Hughes
	9	* 2000-2002 x86-64 support by Andi Kleen
	10	*
	11	* $Id: signal.c,v 1.18 2001/10/17 22:30:37 ak Exp $
	12	*/
	13
	14	#include <linux/sched.h>
	15	#include <linux/mm.h>
	16	#include <linux/smp.h>
	17	#include <linux/smp_lock.h>
	18	#include <linux/kernel.h>
	19	#include <linux/signal.h>
	20	#include <linux/errno.h>
	21	#include <linux/wait.h>
	22	#include <linux/ptrace.h>
	23	#include <linux/unistd.h>
	24	#include <linux/stddef.h>
	25	#include <linux/personality.h>
	26	#include <linux/compiler.h>
	27	#include <asm/ucontext.h>
	28	#include <asm/uaccess.h>
	29	#include <asm/i387.h>
	30	#include <asm/proto.h>
c5924b7d	31	#include <asm/ia32_unistd.h>
1da177e4 LT	32
	33	/* #define DEBUG_SIG 1 */
	34
	35	#define _BLOCKABLE (~(sigmask(SIGKILL) \| sigmask(SIGSTOP)))
	36
0928d6ef	37	int ia32_setup_rt_frame(int sig, struct k_sigaction ka, siginfo_t info,
1da177e4	38	sigset_t set, struct pt_regs regs);
0928d6ef	39	int ia32_setup_frame(int sig, struct k_sigaction *ka,
1da177e4 LT	40	sigset_t set, struct pt_regs regs);
	41
	42	asmlinkage long
	43	sys_rt_sigsuspend(sigset_t __user unewset, size_t sigsetsize, struct pt_regs regs)
	44	{
	45	sigset_t saveset, newset;
	46
	47	/* XXX: Don't preclude handling different sized sigset_t's. */
	48	if (sigsetsize != sizeof(sigset_t))
	49	return -EINVAL;
	50
	51	if (copy_from_user(&newset, unewset, sizeof(newset)))
	52	return -EFAULT;
	53	sigdelsetmask(&newset, ~_BLOCKABLE);
	54
	55	spin_lock_irq(&current->sighand->siglock);
	56	saveset = current->blocked;
	57	current->blocked = newset;
	58	recalc_sigpending();
	59	spin_unlock_irq(&current->sighand->siglock);
	60	#ifdef DEBUG_SIG
	61	printk("rt_sigsuspend savset(%lx) newset(%lx) regs(%p) rip(%lx)\n",
	62	saveset, newset, regs, regs->rip);
	63	#endif
	64	regs->rax = -EINTR;
	65	while (1) {
	66	current->state = TASK_INTERRUPTIBLE;
	67	schedule();
	68	if (do_signal(regs, &saveset))
	69	return -EINTR;
	70	}
	71	}
	72
	73	asmlinkage long
	74	sys_sigaltstack(const stack_t __user uss, stack_t __user uoss,
	75	struct pt_regs *regs)
	76	{
	77	return do_sigaltstack(uss, uoss, regs->rsp);
	78	}
	79
	80
	81	/*
	82	* Do a signal return; undo the signal stack.
	83	*/
	84
	85	struct rt_sigframe
	86	{
993fb38b	87	char __user *pretcode;
1da177e4 LT	88	struct ucontext uc;
	89	struct siginfo info;
	90	};
	91
	92	static int
	93	restore_sigcontext(struct pt_regs regs, struct sigcontext __user sc, unsigned long *prax)
	94	{
	95	unsigned int err = 0;
	96
	97	/* Always make any pending restarted system calls return -EINTR */
	98	current_thread_info()->restart_block.fn = do_no_restart_syscall;
	99
	100	#define COPY(x) err \|= __get_user(regs->x, &sc->x)
	101
	102	COPY(rdi); COPY(rsi); COPY(rbp); COPY(rsp); COPY(rbx);
	103	COPY(rdx); COPY(rcx); COPY(rip);
	104	COPY(r8);
	105	COPY(r9);
	106	COPY(r10);
	107	COPY(r11);
	108	COPY(r12);
	109	COPY(r13);
	110	COPY(r14);
	111	COPY(r15);
	112
	113	{
	114	unsigned int tmpflags;
	115	err \|= __get_user(tmpflags, &sc->eflags);
	116	regs->eflags = (regs->eflags & ~0x40DD5) \| (tmpflags & 0x40DD5);
	117	regs->orig_rax = -1; /* disable syscall checks */
	118	}
	119
	120	{
	121	struct _fpstate __user * buf;
	122	err \|= __get_user(buf, &sc->fpstate);
	123
	124	if (buf) {
	125	if (!access_ok(VERIFY_READ, buf, sizeof(*buf)))
	126	goto badframe;
	127	err \|= restore_i387(buf);
	128	} else {
	129	struct task_struct *me = current;
	130	if (used_math()) {
	131	clear_fpu(me);
	132	clear_used_math();
	133	}
	134	}
	135	}
	136
	137	err \|= __get_user(*prax, &sc->rax);
	138	return err;
	139
	140	badframe:
	141	return 1;
	142	}
	143
	144	asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
	145	{
	146	struct rt_sigframe __user *frame;
	147	sigset_t set;
	148	unsigned long eax;
	149
	150	frame = (struct rt_sigframe __user *)(regs->rsp - 8);
	151	if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) {
152	goto badframe;
153	}
154	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) {
155	goto badframe;
156	}
157
158	sigdelsetmask(&set, ~_BLOCKABLE);
159	spin_lock_irq(&current->sighand->siglock);
160	current->blocked = set;
161	recalc_sigpending();
162	spin_unlock_irq(&current->sighand->siglock);
163
164	if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &eax))
165	goto badframe;
166
167	#ifdef DEBUG_SIG
168	printk("%d sigreturn rip:%lx rsp:%lx frame:%p rax:%lx\n",current->pid,regs.rip,regs.rsp,frame,eax);
169	#endif
170
171	if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->rsp) == -EFAULT)
172	goto badframe;
173
174	return eax;
175
176	badframe:
177	signal_fault(regs,frame,"sigreturn");
178	return 0;
179	}
180
181	/*
182	* Set up a signal frame.
183	*/
184
185	static inline int
186	setup_sigcontext(struct sigcontext __user sc, struct pt_regs regs, unsigned long mask, struct task_struct *me)
187	{
188	int err = 0;
1da177e4 LT	189
	190	err \|= __put_user(0, &sc->gs);
	191	err \|= __put_user(0, &sc->fs);
	192
	193	err \|= __put_user(regs->rdi, &sc->rdi);
	194	err \|= __put_user(regs->rsi, &sc->rsi);
	195	err \|= __put_user(regs->rbp, &sc->rbp);
	196	err \|= __put_user(regs->rsp, &sc->rsp);
	197	err \|= __put_user(regs->rbx, &sc->rbx);
	198	err \|= __put_user(regs->rdx, &sc->rdx);
	199	err \|= __put_user(regs->rcx, &sc->rcx);
	200	err \|= __put_user(regs->rax, &sc->rax);
	201	err \|= __put_user(regs->r8, &sc->r8);
	202	err \|= __put_user(regs->r9, &sc->r9);
	203	err \|= __put_user(regs->r10, &sc->r10);
	204	err \|= __put_user(regs->r11, &sc->r11);
	205	err \|= __put_user(regs->r12, &sc->r12);
	206	err \|= __put_user(regs->r13, &sc->r13);
	207	err \|= __put_user(regs->r14, &sc->r14);
	208	err \|= __put_user(regs->r15, &sc->r15);
	209	err \|= __put_user(me->thread.trap_no, &sc->trapno);
	210	err \|= __put_user(me->thread.error_code, &sc->err);
	211	err \|= __put_user(regs->rip, &sc->rip);
be61bff7	212	err \|= __put_user(regs->eflags, &sc->eflags);
1da177e4 LT	213	err \|= __put_user(mask, &sc->oldmask);
	214	err \|= __put_user(me->thread.cr2, &sc->cr2);
	215
	216	return err;
	217	}
	218
	219	/*
	220	* Determine which stack to use..
	221	*/
	222
	223	static void __user *
	224	get_stack(struct k_sigaction ka, struct pt_regs regs, unsigned long size)
	225	{
	226	unsigned long rsp;
	227
	228	/* Default to using normal stack - redzone*/
	229	rsp = regs->rsp - 128;
	230
	231	/* This is the X/Open sanctioned signal stack switching. */
	232	/* RED-PEN: redzone on that stack? */
	233	if (ka->sa.sa_flags & SA_ONSTACK) {
	234	if (sas_ss_flags(rsp) == 0)
	235	rsp = current->sas_ss_sp + current->sas_ss_size;
	236	}
	237
	238	return (void __user *)round_down(rsp - size, 16);
	239	}
	240
0928d6ef	241	static int setup_rt_frame(int sig, struct k_sigaction ka, siginfo_t info,
1da177e4 LT	242	sigset_t set, struct pt_regs regs)
	243	{
	244	struct rt_sigframe __user *frame;
	245	struct _fpstate __user *fp = NULL;
	246	int err = 0;
	247	struct task_struct *me = current;
	248
	249	if (used_math()) {
	250	fp = get_stack(ka, regs, sizeof(struct _fpstate));
	251	frame = (void __user *)round_down(
	252	(unsigned long)fp - sizeof(struct rt_sigframe), 16) - 8;
	253
	254	if (!access_ok(VERIFY_WRITE, fp, sizeof(struct _fpstate)))
	255	goto give_sigsegv;
	256
	257	if (save_i387(fp) < 0)
	258	err \|= -1;
	259	} else
	260	frame = get_stack(ka, regs, sizeof(struct rt_sigframe)) - 8;
	261
	262	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
	263	goto give_sigsegv;
	264
	265	if (ka->sa.sa_flags & SA_SIGINFO) {
	266	err \|= copy_siginfo_to_user(&frame->info, info);
	267	if (err)
	268	goto give_sigsegv;
	269	}
	270
	271	/* Create the ucontext. */
	272	err \|= __put_user(0, &frame->uc.uc_flags);
	273	err \|= __put_user(0, &frame->uc.uc_link);
	274	err \|= __put_user(me->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
	275	err \|= __put_user(sas_ss_flags(regs->rsp),
	276	&frame->uc.uc_stack.ss_flags);
	277	err \|= __put_user(me->sas_ss_size, &frame->uc.uc_stack.ss_size);
	278	err \|= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0], me);
	279	err \|= __put_user(fp, &frame->uc.uc_mcontext.fpstate);
	280	if (sizeof(*set) == 16) {
	281	__put_user(set->sig[0], &frame->uc.uc_sigmask.sig[0]);
	282	__put_user(set->sig[1], &frame->uc.uc_sigmask.sig[1]);
	283	} else
	284	err \|= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
	285
	286	/* Set up to return from userspace. If provided, use a stub
	287	already in userspace. */
	288	/* x86-64 should always use SA_RESTORER. */
	289	if (ka->sa.sa_flags & SA_RESTORER) {
	290	err \|= __put_user(ka->sa.sa_restorer, &frame->pretcode);
	291	} else {
	292	/* could use a vstub here */
	293	goto give_sigsegv;
	294	}
	295
	296	if (err)
	297	goto give_sigsegv;
	298
	299	#ifdef DEBUG_SIG
	300	printk("%d old rip %lx old rsp %lx old rax %lx\n", current->pid,regs->rip,regs->rsp,regs->rax);
	301	#endif
	302
	303	/* Set up registers for signal handler */
	304	{
	305	struct exec_domain *ed = current_thread_info()->exec_domain;
306	if (unlikely(ed && ed->signal_invmap && sig < 32))
307	sig = ed->signal_invmap[sig];
308	}
309	regs->rdi = sig;
310	/* In case the signal handler was declared without prototypes */
311	regs->rax = 0;
312
313	/* This also works for non SA_SIGINFO handlers because they expect the
314	next argument after the signal number on the stack. */
315	regs->rsi = (unsigned long)&frame->info;
316	regs->rdx = (unsigned long)&frame->uc;
317	regs->rip = (unsigned long) ka->sa.sa_handler;
318
319	regs->rsp = (unsigned long)frame;
320
321	set_fs(USER_DS);
be61bff7 AK	322	regs->eflags &= ~TF_MASK;
	323	if (test_thread_flag(TIF_SINGLESTEP))
	324	ptrace_notify(SIGTRAP);
1da177e4 LT	325	#ifdef DEBUG_SIG
	326	printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n",
	327	current->comm, current->pid, frame, regs->rip, frame->pretcode);
	328	#endif
	329
0928d6ef	330	return 1;
1da177e4 LT	331
	332	give_sigsegv:
	333	force_sigsegv(sig, current);
0928d6ef	334	return 0;
1da177e4 LT	335	}
	336
	337	/*
	338	* OK, we're invoking a handler
	339	*/
	340
0928d6ef	341	static int
1da177e4 LT	342	handle_signal(unsigned long sig, siginfo_t info, struct k_sigaction ka,
	343	sigset_t oldset, struct pt_regs regs)
	344	{
0928d6ef RM	345	int ret;
0928d6ef RM	346
1da177e4 LT	347	#ifdef DEBUG_SIG
	348	printk("handle_signal pid:%d sig:%lu rip:%lx rsp:%lx regs=%p\n",
	349	current->pid, sig,
	350	regs->rip, regs->rsp, regs);
	351	#endif
	352
	353	/* Are we from a system call? */
	354	if ((long)regs->orig_rax >= 0) {
	355	/* If so, check system call restarting.. */
	356	switch (regs->rax) {
	357	case -ERESTART_RESTARTBLOCK:
	358	case -ERESTARTNOHAND:
	359	regs->rax = -EINTR;
	360	break;
	361
	362	case -ERESTARTSYS:
	363	if (!(ka->sa.sa_flags & SA_RESTART)) {
	364	regs->rax = -EINTR;
	365	break;
	366	}
	367	/* fallthrough */
	368	case -ERESTARTNOINTR:
	369	regs->rax = regs->orig_rax;
	370	regs->rip -= 2;
	371	break;
	372	}
	373	}
	374
d61915da AK	375	/*
	376	* If TF is set due to a debugger (PT_DTRACE), clear the TF
	377	* flag so that register information in the sigcontext is
	378	* correct.
	379	*/
	380	if (unlikely(regs->eflags & TF_MASK)) {
	381	if (likely(current->ptrace & PT_DTRACE)) {
	382	current->ptrace &= ~PT_DTRACE;
	383	regs->eflags &= ~TF_MASK;
	384	}
	385	}
	386
1da177e4 LT	387	#ifdef CONFIG_IA32_EMULATION
	388	if (test_thread_flag(TIF_IA32)) {
	389	if (ka->sa.sa_flags & SA_SIGINFO)
0928d6ef	390	ret = ia32_setup_rt_frame(sig, ka, info, oldset, regs);
1da177e4	391	else
0928d6ef	392	ret = ia32_setup_frame(sig, ka, oldset, regs);
1da177e4 LT	393	} else
1da177e4 LT	394	#endif
0928d6ef	395	ret = setup_rt_frame(sig, ka, info, oldset, regs);
1da177e4	396
0928d6ef	397	if (ret && !(ka->sa.sa_flags & SA_NODEFER)) {
1da177e4 LT	398	spin_lock_irq(&current->sighand->siglock);
	399	sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
	400	sigaddset(&current->blocked,sig);
	401	recalc_sigpending();
	402	spin_unlock_irq(&current->sighand->siglock);
	403	}
0928d6ef RM	404
0928d6ef RM	405	return ret;
1da177e4 LT	406	}
	407
	408	/*
	409	* Note that 'init' is a special process: it doesn't get signals it doesn't
	410	* want to handle. Thus you cannot kill init even with a SIGKILL even by
	411	* mistake.
	412	*/
	413	int do_signal(struct pt_regs regs, sigset_t oldset)
	414	{
	415	struct k_sigaction ka;
	416	siginfo_t info;
	417	int signr;
	418
	419	/*
	420	* We want the common case to go fast, which
	421	* is why we may in certain cases get here from
	422	* kernel mode. Just return without doing anything
	423	* if so.
	424	*/
	425	if ((regs->cs & 3) != 3)
	426	return 1;
	427
	428	if (try_to_freeze(0))
	429	goto no_signal;
	430
	431	if (!oldset)
	432	oldset = &current->blocked;
	433
	434	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
	435	if (signr > 0) {
	436	/* Reenable any watchpoints before delivering the
	437	* signal to user space. The processor register will
	438	* have been cleared if the watchpoint triggered
	439	* inside the kernel.
	440	*/
	441	if (current->thread.debugreg7)
e9129e56	442	set_debugreg(current->thread.debugreg7, 7);
1da177e4 LT	443
1da177e4 LT	444	/* Whee! Actually deliver the signal. */
0928d6ef	445	return handle_signal(signr, &info, &ka, oldset, regs);
1da177e4 LT	446	}
	447
	448	no_signal:
	449	/* Did we come from a system call? */
	450	if ((long)regs->orig_rax >= 0) {
	451	/* Restart the system call - no handlers present */
	452	long res = regs->rax;
	453	if (res == -ERESTARTNOHAND \|\|
	454	res == -ERESTARTSYS \|\|
	455	res == -ERESTARTNOINTR) {
	456	regs->rax = regs->orig_rax;
	457	regs->rip -= 2;
	458	}
	459	if (regs->rax == (unsigned long)-ERESTART_RESTARTBLOCK) {
607a1685 AK	460	regs->rax = test_thread_flag(TIF_IA32) ?
	461	__NR_ia32_restart_syscall :
	462	__NR_restart_syscall;
1da177e4 LT	463	regs->rip -= 2;
	464	}
	465	}
	466	return 0;
	467	}
	468
	469	void do_notify_resume(struct pt_regs regs, sigset_t oldset, __u32 thread_info_flags)
	470	{
	471	#ifdef DEBUG_SIG
	472	printk("do_notify_resume flags:%x rip:%lx rsp:%lx caller:%lx pending:%lx\n",
	473	thread_info_flags, regs->rip, regs->rsp, __builtin_return_address(0),signal_pending(current));
	474	#endif
	475
	476	/* Pending single-step? */
	477	if (thread_info_flags & _TIF_SINGLESTEP) {
	478	regs->eflags \|= TF_MASK;
	479	clear_thread_flag(TIF_SINGLESTEP);
	480	}
	481
	482	/* deal with pending signal delivery */
	483	if (thread_info_flags & _TIF_SIGPENDING)
	484	do_signal(regs,oldset);
	485	}
	486
	487	void signal_fault(struct pt_regs regs, void __user frame, char *where)
	488	{
	489	struct task_struct *me = current;
	490	if (exception_trace)
	491	printk("%s[%d] bad frame in %s frame:%p rip:%lx rsp:%lx orax:%lx\n",
	492	me->comm,me->pid,where,frame,regs->rip,regs->rsp,regs->orig_rax);
	493
	494	force_sig(SIGSEGV, me);
	495	}