[deliverable/linux.git] / arch / x86 / kernel / signal_64.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
 */

#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/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>
#include <asm/mce.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_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
		struct pt_regs *regs)
{
	return do_sigaltstack(uss, uoss, regs->sp);
}


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

	COPYR(di); COPYR(si); COPYR(bp); COPYR(sp); COPYR(bx);
	COPYR(dx); COPYR(cx); COPYR(ip);
	COPY(r8);
	COPY(r9);
	COPY(r10);
	COPY(r11);
	COPY(r12);
	COPY(r13);
	COPY(r14);
	COPY(r15);

	/* Kernel saves and restores only the CS segment register on signals,
	 * which is the bare minimum needed to allow mixed 32/64-bit code.
	 * App's signal handler can save/restore other segments if needed. */
	{
		unsigned cs;
		err |= __get_user(cs, &sc->cs);
		regs->cs = cs | 3;	/* Force into user mode */
	}

	{
		unsigned int tmpflags;
		err |= __get_user(tmpflags, &sc->eflags);
		regs->flags = (regs->flags & ~0x40DD5) | (tmpflags & 0x40DD5);
		regs->orig_ax = -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 ax;

	frame = (struct rt_sigframe __user *)(regs->sp - 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, &ax))
		goto badframe;

#ifdef DEBUG_SIG
	printk("%d sigreturn ip:%lx sp:%lx frame:%p ax:%lx\n",current->pid,regs->ip,regs->sp,frame,ax);
#endif

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

	return ax;

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

	err |= __put_user(regs->di, &sc->rdi);
	err |= __put_user(regs->si, &sc->rsi);
	err |= __put_user(regs->bp, &sc->rbp);
	err |= __put_user(regs->sp, &sc->rsp);
	err |= __put_user(regs->bx, &sc->rbx);
	err |= __put_user(regs->dx, &sc->rdx);
	err |= __put_user(regs->cx, &sc->rcx);
	err |= __put_user(regs->ax, &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->ip, &sc->rip);
	err |= __put_user(regs->flags, &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 sp;

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

	/* This is the X/Open sanctioned signal stack switching.  */
	if (ka->sa.sa_flags & SA_ONSTACK) {
		if (sas_ss_flags(sp) == 0)
			sp = current->sas_ss_sp + current->sas_ss_size;
	}

	return (void __user *)round_down(sp - 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->sp),
			  &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 ip %lx old sp %lx old ax %lx\n", current->pid,regs->ip,regs->sp,regs->ax);
#endif

	/* Set up registers for signal handler */
	regs->di = sig;
	/* In case the signal handler was declared without prototypes */ 
	regs->ax = 0;

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

	regs->sp = (unsigned long)frame;

	/* Set up the CS register to run signal handlers in 64-bit mode,
	   even if the handler happens to be interrupting 32-bit code. */
	regs->cs = __USER_CS;

	/* This, by contrast, has nothing to do with segment registers -
	   see include/asm-x86_64/uaccess.h for details. */
	set_fs(USER_DS);

	regs->flags &= ~TF_MASK;
	if (test_thread_flag(TIF_SINGLESTEP))
		ptrace_notify(SIGTRAP);
#ifdef DEBUG_SIG
	printk("SIG deliver (%s:%d): sp=%p pc=%lx ra=%p\n",
		current->comm, current->pid, frame, regs->ip, frame->pretcode);
#endif

	return 0;

give_sigsegv:
	force_sigsegv(sig, current);
	return -EFAULT;
}

/*
 * 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 ip:%lx sp:%lx regs=%p\n",
		current->pid, sig,
		regs->ip, regs->sp, regs);
#endif

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

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

	/*
	 * If TF is set due to a debugger (TIF_FORCED_TF), clear the TF
	 * flag so that register information in the sigcontext is correct.
	 */
	if (unlikely(regs->flags & X86_EFLAGS_TF) &&
	    likely(test_and_clear_thread_flag(TIF_FORCED_TF)))
		regs->flags &= ~X86_EFLAGS_TF;

#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 == 0) {
		spin_lock_irq(&current->sighand->siglock);
		sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
		if (!(ka->sa.sa_flags & SA_NODEFER))
			sigaddset(&current->blocked,sig);
		recalc_sigpending();
		spin_unlock_irq(&current->sighand->siglock);
	}

	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.
 */
static void do_signal(struct pt_regs *regs)
{
	struct k_sigaction ka;
	siginfo_t info;
	int signr;
	sigset_t *oldset;

	/*
	 * We want the common case to go fast, which
	 * is why we may in certain cases get here from
	 * kernel mode. Just return without doing anything
	 * if so.
	 */
	if (!user_mode(regs))
		return;

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

	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
	if (signr > 0) {
		/* Re-enable 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.  */
		if (handle_signal(signr, &info, &ka, oldset, regs) == 0) {
			/* 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 */
			clear_thread_flag(TIF_RESTORE_SIGMASK);
		}
		return;
	}

	/* Did we come from a system call? */
	if ((long)regs->orig_ax >= 0) {
		/* Restart the system call - no handlers present */
		long res = regs->ax;
		switch (res) {
		case -ERESTARTNOHAND:
		case -ERESTARTSYS:
		case -ERESTARTNOINTR:
			regs->ax = regs->orig_ax;
			regs->ip -= 2;
			break;
		case -ERESTART_RESTARTBLOCK:
			regs->ax = test_thread_flag(TIF_IA32) ?
					__NR_ia32_restart_syscall :
					__NR_restart_syscall;
			regs->ip -= 2;
			break;
		}
	}

	/* 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, void *unused, __u32 thread_info_flags)
{
#ifdef DEBUG_SIG
	printk("do_notify_resume flags:%x ip:%lx sp:%lx caller:%p pending:%x\n",
	       thread_info_flags, regs->ip, regs->sp, __builtin_return_address(0),signal_pending(current));
#endif
	       
	/* Pending single-step? */
	if (thread_info_flags & _TIF_SINGLESTEP) {
		regs->flags |= TF_MASK;
		clear_thread_flag(TIF_SINGLESTEP);
	}

#ifdef CONFIG_X86_MCE
	/* notify userspace of pending MCEs */
	if (thread_info_flags & _TIF_MCE_NOTIFY)
		mce_notify_user();
#endif /* CONFIG_X86_MCE */

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

	if (thread_info_flags & _TIF_HRTICK_RESCHED)
		hrtick_resched();
}

void signal_fault(struct pt_regs *regs, void __user *frame, char *where)
{ 
	struct task_struct *me = current; 
	if (show_unhandled_signals && printk_ratelimit())
		printk("%s[%d] bad frame in %s frame:%p ip:%lx sp:%lx orax:%lx\n",
	       me->comm,me->pid,where,frame,regs->ip,regs->sp,regs->orig_ax);

	force_sig(SIGSEGV, me); 
}
Commit	Line	Data
1da177e4	1	/*
1da177e4 LT	2	* Copyright (C) 1991, 1992 Linus Torvalds
	3	* Copyright (C) 2000, 2001, 2002 Andi Kleen SuSE Labs
	4	*
	5	* 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
	6	* 2000-06-20 Pentium III FXSR, SSE support by Gareth Hughes
	7	* 2000-2002 x86-64 support by Andi Kleen
1da177e4 LT	8	*/
	9
	10	#include <linux/sched.h>
	11	#include <linux/mm.h>
	12	#include <linux/smp.h>
1da177e4 LT	13	#include <linux/kernel.h>
	14	#include <linux/signal.h>
	15	#include <linux/errno.h>
	16	#include <linux/wait.h>
	17	#include <linux/ptrace.h>
	18	#include <linux/unistd.h>
	19	#include <linux/stddef.h>
	20	#include <linux/personality.h>
	21	#include <linux/compiler.h>
	22	#include <asm/ucontext.h>
	23	#include <asm/uaccess.h>
	24	#include <asm/i387.h>
	25	#include <asm/proto.h>
c5924b7d	26	#include <asm/ia32_unistd.h>
e02e68d3	27	#include <asm/mce.h>
1da177e4 LT	28
	29	/* #define DEBUG_SIG 1 */
	30
	31	#define _BLOCKABLE (~(sigmask(SIGKILL) \| sigmask(SIGSTOP)))
	32
0928d6ef	33	int ia32_setup_rt_frame(int sig, struct k_sigaction ka, siginfo_t info,
1da177e4	34	sigset_t set, struct pt_regs regs);
0928d6ef	35	int ia32_setup_frame(int sig, struct k_sigaction *ka,
1da177e4 LT	36	sigset_t set, struct pt_regs regs);
1da177e4 LT	37
1da177e4 LT	38	asmlinkage long
	39	sys_sigaltstack(const stack_t __user uss, stack_t __user uoss,
	40	struct pt_regs *regs)
	41	{
65ea5b03	42	return do_sigaltstack(uss, uoss, regs->sp);
1da177e4 LT	43	}
	44
	45
	46	/*
	47	* Do a signal return; undo the signal stack.
	48	*/
	49
	50	struct rt_sigframe
	51	{
993fb38b	52	char __user *pretcode;
1da177e4 LT	53	struct ucontext uc;
	54	struct siginfo info;
	55	};
	56
	57	static int
	58	restore_sigcontext(struct pt_regs regs, struct sigcontext __user sc, unsigned long *prax)
	59	{
	60	unsigned int err = 0;
	61
	62	/* Always make any pending restarted system calls return -EINTR */
	63	current_thread_info()->restart_block.fn = do_no_restart_syscall;
	64
65ea5b03	65	#define COPYR(x) err \|= __get_user(regs->x, &sc->r ## x)
1da177e4 LT	66	#define COPY(x) err \|= __get_user(regs->x, &sc->x)
1da177e4 LT	67
65ea5b03 PA	68	COPYR(di); COPYR(si); COPYR(bp); COPYR(sp); COPYR(bx);
65ea5b03 PA	69	COPYR(dx); COPYR(cx); COPYR(ip);
1da177e4 LT	70	COPY(r8);
	71	COPY(r9);
	72	COPY(r10);
	73	COPY(r11);
	74	COPY(r12);
	75	COPY(r13);
	76	COPY(r14);
	77	COPY(r15);
	78
e4e5d324 BF	79	/* Kernel saves and restores only the CS segment register on signals,
	80	* which is the bare minimum needed to allow mixed 32/64-bit code.
	81	* App's signal handler can save/restore other segments if needed. */
	82	{
	83	unsigned cs;
	84	err \|= __get_user(cs, &sc->cs);
	85	regs->cs = cs \| 3; /* Force into user mode */
	86	}
	87
1da177e4 LT	88	{
	89	unsigned int tmpflags;
	90	err \|= __get_user(tmpflags, &sc->eflags);
65ea5b03 PA	91	regs->flags = (regs->flags & ~0x40DD5) \| (tmpflags & 0x40DD5);
65ea5b03 PA	92	regs->orig_ax = -1; /* disable syscall checks */
1da177e4 LT	93	}
	94
	95	{
	96	struct _fpstate __user * buf;
	97	err \|= __get_user(buf, &sc->fpstate);
	98
	99	if (buf) {
	100	if (!access_ok(VERIFY_READ, buf, sizeof(*buf)))
	101	goto badframe;
	102	err \|= restore_i387(buf);
	103	} else {
	104	struct task_struct *me = current;
	105	if (used_math()) {
	106	clear_fpu(me);
	107	clear_used_math();
	108	}
	109	}
	110	}
	111
	112	err \|= __get_user(*prax, &sc->rax);
	113	return err;
	114
	115	badframe:
	116	return 1;
	117	}
	118
	119	asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
	120	{
	121	struct rt_sigframe __user *frame;
	122	sigset_t set;
65ea5b03	123	unsigned long ax;
1da177e4	124
65ea5b03	125	frame = (struct rt_sigframe __user *)(regs->sp - 8);
1da177e4 LT	126	if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) {
	127	goto badframe;
	128	}
	129	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) {
	130	goto badframe;
	131	}
	132
	133	sigdelsetmask(&set, ~_BLOCKABLE);
	134	spin_lock_irq(&current->sighand->siglock);
	135	current->blocked = set;
	136	recalc_sigpending();
	137	spin_unlock_irq(&current->sighand->siglock);
	138
65ea5b03	139	if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax))
1da177e4 LT	140	goto badframe;
	141
	142	#ifdef DEBUG_SIG
65ea5b03	143	printk("%d sigreturn ip:%lx sp:%lx frame:%p ax:%lx\n",current->pid,regs->ip,regs->sp,frame,ax);
1da177e4 LT	144	#endif
1da177e4 LT	145
65ea5b03	146	if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->sp) == -EFAULT)
1da177e4 LT	147	goto badframe;
1da177e4 LT	148
65ea5b03	149	return ax;
1da177e4 LT	150
	151	badframe:
	152	signal_fault(regs,frame,"sigreturn");
	153	return 0;
	154	}
	155
	156	/*
	157	* Set up a signal frame.
	158	*/
	159
	160	static inline int
	161	setup_sigcontext(struct sigcontext __user sc, struct pt_regs regs, unsigned long mask, struct task_struct *me)
	162	{
	163	int err = 0;
1da177e4	164
e4e5d324	165	err \|= __put_user(regs->cs, &sc->cs);
1da177e4 LT	166	err \|= __put_user(0, &sc->gs);
	167	err \|= __put_user(0, &sc->fs);
	168
65ea5b03 PA	169	err \|= __put_user(regs->di, &sc->rdi);
	170	err \|= __put_user(regs->si, &sc->rsi);
	171	err \|= __put_user(regs->bp, &sc->rbp);
	172	err \|= __put_user(regs->sp, &sc->rsp);
	173	err \|= __put_user(regs->bx, &sc->rbx);
	174	err \|= __put_user(regs->dx, &sc->rdx);
	175	err \|= __put_user(regs->cx, &sc->rcx);
	176	err \|= __put_user(regs->ax, &sc->rax);
1da177e4 LT	177	err \|= __put_user(regs->r8, &sc->r8);
	178	err \|= __put_user(regs->r9, &sc->r9);
	179	err \|= __put_user(regs->r10, &sc->r10);
	180	err \|= __put_user(regs->r11, &sc->r11);
	181	err \|= __put_user(regs->r12, &sc->r12);
	182	err \|= __put_user(regs->r13, &sc->r13);
	183	err \|= __put_user(regs->r14, &sc->r14);
	184	err \|= __put_user(regs->r15, &sc->r15);
	185	err \|= __put_user(me->thread.trap_no, &sc->trapno);
	186	err \|= __put_user(me->thread.error_code, &sc->err);
65ea5b03 PA	187	err \|= __put_user(regs->ip, &sc->rip);
65ea5b03 PA	188	err \|= __put_user(regs->flags, &sc->eflags);
1da177e4 LT	189	err \|= __put_user(mask, &sc->oldmask);
	190	err \|= __put_user(me->thread.cr2, &sc->cr2);
	191
	192	return err;
	193	}
	194
	195	/*
	196	* Determine which stack to use..
	197	*/
	198
	199	static void __user *
	200	get_stack(struct k_sigaction ka, struct pt_regs regs, unsigned long size)
	201	{
65ea5b03	202	unsigned long sp;
1da177e4 LT	203
1da177e4 LT	204	/* Default to using normal stack - redzone*/
65ea5b03	205	sp = regs->sp - 128;
1da177e4 LT	206
1da177e4 LT	207	/* This is the X/Open sanctioned signal stack switching. */
1da177e4	208	if (ka->sa.sa_flags & SA_ONSTACK) {
65ea5b03 PA	209	if (sas_ss_flags(sp) == 0)
65ea5b03 PA	210	sp = current->sas_ss_sp + current->sas_ss_size;
1da177e4 LT	211	}
1da177e4 LT	212
65ea5b03	213	return (void __user *)round_down(sp - size, 16);
1da177e4 LT	214	}
1da177e4 LT	215
0928d6ef	216	static int setup_rt_frame(int sig, struct k_sigaction ka, siginfo_t info,
1da177e4 LT	217	sigset_t set, struct pt_regs regs)
	218	{
	219	struct rt_sigframe __user *frame;
	220	struct _fpstate __user *fp = NULL;
	221	int err = 0;
	222	struct task_struct *me = current;
	223
	224	if (used_math()) {
	225	fp = get_stack(ka, regs, sizeof(struct _fpstate));
	226	frame = (void __user *)round_down(
	227	(unsigned long)fp - sizeof(struct rt_sigframe), 16) - 8;
	228
	229	if (!access_ok(VERIFY_WRITE, fp, sizeof(struct _fpstate)))
	230	goto give_sigsegv;
	231
	232	if (save_i387(fp) < 0)
	233	err \|= -1;
	234	} else
	235	frame = get_stack(ka, regs, sizeof(struct rt_sigframe)) - 8;
	236
	237	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
	238	goto give_sigsegv;
	239
	240	if (ka->sa.sa_flags & SA_SIGINFO) {
	241	err \|= copy_siginfo_to_user(&frame->info, info);
	242	if (err)
	243	goto give_sigsegv;
	244	}
	245
	246	/* Create the ucontext. */
	247	err \|= __put_user(0, &frame->uc.uc_flags);
	248	err \|= __put_user(0, &frame->uc.uc_link);
	249	err \|= __put_user(me->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
65ea5b03	250	err \|= __put_user(sas_ss_flags(regs->sp),
1da177e4 LT	251	&frame->uc.uc_stack.ss_flags);
	252	err \|= __put_user(me->sas_ss_size, &frame->uc.uc_stack.ss_size);
	253	err \|= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0], me);
	254	err \|= __put_user(fp, &frame->uc.uc_mcontext.fpstate);
	255	if (sizeof(*set) == 16) {
	256	__put_user(set->sig[0], &frame->uc.uc_sigmask.sig[0]);
	257	__put_user(set->sig[1], &frame->uc.uc_sigmask.sig[1]);
	258	} else
	259	err \|= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
	260
	261	/* Set up to return from userspace. If provided, use a stub
	262	already in userspace. */
	263	/* x86-64 should always use SA_RESTORER. */
	264	if (ka->sa.sa_flags & SA_RESTORER) {
	265	err \|= __put_user(ka->sa.sa_restorer, &frame->pretcode);
	266	} else {
	267	/* could use a vstub here */
	268	goto give_sigsegv;
	269	}
	270
	271	if (err)
	272	goto give_sigsegv;
	273
	274	#ifdef DEBUG_SIG
65ea5b03	275	printk("%d old ip %lx old sp %lx old ax %lx\n", current->pid,regs->ip,regs->sp,regs->ax);
1da177e4 LT	276	#endif
	277
	278	/* Set up registers for signal handler */
65ea5b03	279	regs->di = sig;
1da177e4	280	/* In case the signal handler was declared without prototypes */
65ea5b03	281	regs->ax = 0;
1da177e4 LT	282
	283	/* This also works for non SA_SIGINFO handlers because they expect the
	284	next argument after the signal number on the stack. */
65ea5b03 PA	285	regs->si = (unsigned long)&frame->info;
	286	regs->dx = (unsigned long)&frame->uc;
	287	regs->ip = (unsigned long) ka->sa.sa_handler;
1da177e4	288
65ea5b03	289	regs->sp = (unsigned long)frame;
1da177e4	290
e4e5d324 BF	291	/* Set up the CS register to run signal handlers in 64-bit mode,
	292	even if the handler happens to be interrupting 32-bit code. */
	293	regs->cs = __USER_CS;
	294
	295	/* This, by contrast, has nothing to do with segment registers -
	296	see include/asm-x86_64/uaccess.h for details. */
1da177e4	297	set_fs(USER_DS);
e4e5d324	298
65ea5b03	299	regs->flags &= ~TF_MASK;
be61bff7 AK	300	if (test_thread_flag(TIF_SINGLESTEP))
be61bff7 AK	301	ptrace_notify(SIGTRAP);
1da177e4	302	#ifdef DEBUG_SIG
1c3d99c1	303	printk("SIG deliver (%s:%d): sp=%p pc=%lx ra=%p\n",
65ea5b03	304	current->comm, current->pid, frame, regs->ip, frame->pretcode);
1da177e4 LT	305	#endif
1da177e4 LT	306
1d001df1	307	return 0;
1da177e4 LT	308
	309	give_sigsegv:
	310	force_sigsegv(sig, current);
1d001df1	311	return -EFAULT;
1da177e4 LT	312	}
	313
	314	/*
	315	* OK, we're invoking a handler
	316	*/
	317
0928d6ef	318	static int
1da177e4 LT	319	handle_signal(unsigned long sig, siginfo_t info, struct k_sigaction ka,
	320	sigset_t oldset, struct pt_regs regs)
	321	{
0928d6ef RM	322	int ret;
0928d6ef RM	323
1da177e4	324	#ifdef DEBUG_SIG
65ea5b03	325	printk("handle_signal pid:%d sig:%lu ip:%lx sp:%lx regs=%p\n",
1da177e4	326	current->pid, sig,
65ea5b03	327	regs->ip, regs->sp, regs);
1da177e4 LT	328	#endif
	329
	330	/* Are we from a system call? */
65ea5b03	331	if ((long)regs->orig_ax >= 0) {
1da177e4	332	/* If so, check system call restarting.. */
65ea5b03	333	switch (regs->ax) {
1da177e4 LT	334	case -ERESTART_RESTARTBLOCK:
1da177e4 LT	335	case -ERESTARTNOHAND:
65ea5b03	336	regs->ax = -EINTR;
1da177e4 LT	337	break;
	338
	339	case -ERESTARTSYS:
	340	if (!(ka->sa.sa_flags & SA_RESTART)) {
65ea5b03	341	regs->ax = -EINTR;
1da177e4 LT	342	break;
	343	}
	344	/* fallthrough */
	345	case -ERESTARTNOINTR:
65ea5b03 PA	346	regs->ax = regs->orig_ax;
65ea5b03 PA	347	regs->ip -= 2;
1da177e4 LT	348	break;
	349	}
	350	}
	351
d61915da	352	/*
e1f28773 RM	353	* If TF is set due to a debugger (TIF_FORCED_TF), clear the TF
e1f28773 RM	354	* flag so that register information in the sigcontext is correct.
d61915da	355	*/
65ea5b03	356	if (unlikely(regs->flags & X86_EFLAGS_TF) &&
e1f28773	357	likely(test_and_clear_thread_flag(TIF_FORCED_TF)))
65ea5b03	358	regs->flags &= ~X86_EFLAGS_TF;
d61915da	359
1da177e4 LT	360	#ifdef CONFIG_IA32_EMULATION
	361	if (test_thread_flag(TIF_IA32)) {
	362	if (ka->sa.sa_flags & SA_SIGINFO)
0928d6ef	363	ret = ia32_setup_rt_frame(sig, ka, info, oldset, regs);
1da177e4	364	else
0928d6ef	365	ret = ia32_setup_frame(sig, ka, oldset, regs);
1da177e4 LT	366	} else
1da177e4 LT	367	#endif
0928d6ef	368	ret = setup_rt_frame(sig, ka, info, oldset, regs);
1da177e4	369
1d001df1	370	if (ret == 0) {
1da177e4 LT	371	spin_lock_irq(&current->sighand->siglock);
1da177e4 LT	372	sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
69be8f18 SR	373	if (!(ka->sa.sa_flags & SA_NODEFER))
69be8f18 SR	374	sigaddset(&current->blocked,sig);
1da177e4 LT	375	recalc_sigpending();
	376	spin_unlock_irq(&current->sighand->siglock);
	377	}
0928d6ef RM	378
0928d6ef RM	379	return ret;
1da177e4 LT	380	}
	381
	382	/*
	383	* Note that 'init' is a special process: it doesn't get signals it doesn't
	384	* want to handle. Thus you cannot kill init even with a SIGKILL even by
	385	* mistake.
	386	*/
1d001df1	387	static void do_signal(struct pt_regs *regs)
1da177e4 LT	388	{
	389	struct k_sigaction ka;
	390	siginfo_t info;
	391	int signr;
1d001df1	392	sigset_t *oldset;
1da177e4 LT	393
	394	/*
	395	* We want the common case to go fast, which
	396	* is why we may in certain cases get here from
	397	* kernel mode. Just return without doing anything
	398	* if so.
	399	*/
76381fee	400	if (!user_mode(regs))
1d001df1	401	return;
1da177e4	402
1d001df1 AK	403	if (test_thread_flag(TIF_RESTORE_SIGMASK))
	404	oldset = &current->saved_sigmask;
	405	else
1da177e4 LT	406	oldset = &current->blocked;
	407
	408	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
	409	if (signr > 0) {
676b1855	410	/* Re-enable any watchpoints before delivering the
1da177e4 LT	411	* signal to user space. The processor register will
	412	* have been cleared if the watchpoint triggered
	413	* inside the kernel.
	414	*/
	415	if (current->thread.debugreg7)
e9129e56	416	set_debugreg(current->thread.debugreg7, 7);
1da177e4 LT	417
1da177e4 LT	418	/* Whee! Actually deliver the signal. */
1d001df1 AK	419	if (handle_signal(signr, &info, &ka, oldset, regs) == 0) {
	420	/* a signal was successfully delivered; the saved
	421	* sigmask will have been stored in the signal frame,
	422	* and will be restored by sigreturn, so we can simply
	423	* clear the TIF_RESTORE_SIGMASK flag */
	424	clear_thread_flag(TIF_RESTORE_SIGMASK);
	425	}
	426	return;
1da177e4 LT	427	}
1da177e4 LT	428
1da177e4	429	/* Did we come from a system call? */
65ea5b03	430	if ((long)regs->orig_ax >= 0) {
1da177e4	431	/* Restart the system call - no handlers present */
65ea5b03	432	long res = regs->ax;
1d001df1 AK	433	switch (res) {
	434	case -ERESTARTNOHAND:
	435	case -ERESTARTSYS:
	436	case -ERESTARTNOINTR:
65ea5b03 PA	437	regs->ax = regs->orig_ax;
65ea5b03 PA	438	regs->ip -= 2;
1d001df1 AK	439	break;
1d001df1 AK	440	case -ERESTART_RESTARTBLOCK:
65ea5b03	441	regs->ax = test_thread_flag(TIF_IA32) ?
607a1685 AK	442	__NR_ia32_restart_syscall :
607a1685 AK	443	__NR_restart_syscall;
65ea5b03	444	regs->ip -= 2;
1d001df1	445	break;
1da177e4 LT	446	}
1da177e4 LT	447	}
1d001df1 AK	448
	449	/* if there's no signal to deliver, we just put the saved sigmask
	450	back. */
	451	if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
	452	clear_thread_flag(TIF_RESTORE_SIGMASK);
	453	sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
	454	}
1da177e4 LT	455	}
1da177e4 LT	456
1d001df1 AK	457	void
1d001df1 AK	458	do_notify_resume(struct pt_regs regs, void unused, __u32 thread_info_flags)
1da177e4 LT	459	{
1da177e4 LT	460	#ifdef DEBUG_SIG
65ea5b03 PA	461	printk("do_notify_resume flags:%x ip:%lx sp:%lx caller:%p pending:%x\n",
65ea5b03 PA	462	thread_info_flags, regs->ip, regs->sp, __builtin_return_address(0),signal_pending(current));
1da177e4 LT	463	#endif
	464
	465	/* Pending single-step? */
	466	if (thread_info_flags & _TIF_SINGLESTEP) {
65ea5b03	467	regs->flags \|= TF_MASK;
1da177e4 LT	468	clear_thread_flag(TIF_SINGLESTEP);
	469	}
	470
e02e68d3 TH	471	#ifdef CONFIG_X86_MCE
	472	/* notify userspace of pending MCEs */
	473	if (thread_info_flags & _TIF_MCE_NOTIFY)
	474	mce_notify_user();
	475	#endif /* CONFIG_X86_MCE */
	476
1da177e4	477	/* deal with pending signal delivery */
1d001df1 AK	478	if (thread_info_flags & (_TIF_SIGPENDING\|_TIF_RESTORE_SIGMASK))
1d001df1 AK	479	do_signal(regs);
8f4d37ec PZ	480
	481	if (thread_info_flags & _TIF_HRTICK_RESCHED)
	482	hrtick_resched();
1da177e4 LT	483	}
	484
	485	void signal_fault(struct pt_regs regs, void __user frame, char *where)
	486	{
	487	struct task_struct *me = current;
abd4f750	488	if (show_unhandled_signals && printk_ratelimit())
65ea5b03 PA	489	printk("%s[%d] bad frame in %s frame:%p ip:%lx sp:%lx orax:%lx\n",
65ea5b03 PA	490	me->comm,me->pid,where,frame,regs->ip,regs->sp,regs->orig_ax);
1da177e4 LT	491
	492	force_sig(SIGSEGV, me);
	493	}