[deliverable/linux.git] / arch / s390 / kernel / signal.c

/*
 *    Copyright IBM Corp. 1999, 2006
 *    Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
 *
 *    Based on Intel version
 * 
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *
 *  1997-11-28  Modified for POSIX.1b signals by Richard Henderson
 */

#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/tty.h>
#include <linux/personality.h>
#include <linux/binfmts.h>
#include <linux/tracehook.h>
#include <linux/syscalls.h>
#include <linux/compat.h>
#include <asm/ucontext.h>
#include <asm/uaccess.h>
#include <asm/lowcore.h>
#include <asm/switch_to.h>
#include "entry.h"

typedef struct 
{
	__u8 callee_used_stack[__SIGNAL_FRAMESIZE];
	struct sigcontext sc;
	_sigregs sregs;
	int signo;
	__u8 retcode[S390_SYSCALL_SIZE];
} sigframe;

typedef struct 
{
	__u8 callee_used_stack[__SIGNAL_FRAMESIZE];
	__u8 retcode[S390_SYSCALL_SIZE];
	struct siginfo info;
	struct ucontext uc;
} rt_sigframe;

/*
 * Atomically swap in the new signal mask, and wait for a signal.
 */
SYSCALL_DEFINE3(sigsuspend, int, history0, int, history1, old_sigset_t, mask)
{
	sigset_t blocked;
	siginitset(&blocked, mask);
	return sigsuspend(&blocked);
}

SYSCALL_DEFINE3(sigaction, int, sig, const struct old_sigaction __user *, act,
		struct old_sigaction __user *, oact)
{
	struct k_sigaction new_ka, old_ka;
	int ret;

	if (act) {
		old_sigset_t mask;
		if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
		    __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
		    __get_user(new_ka.sa.sa_restorer, &act->sa_restorer) ||
		    __get_user(new_ka.sa.sa_flags, &act->sa_flags) ||
		    __get_user(mask, &act->sa_mask))
			return -EFAULT;
		siginitset(&new_ka.sa.sa_mask, mask);
	}

	ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);

	if (!ret && oact) {
		if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
		    __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
		    __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer) ||
		    __put_user(old_ka.sa.sa_flags, &oact->sa_flags) ||
		    __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask))
			return -EFAULT;
	}

	return ret;
}

SYSCALL_DEFINE2(sigaltstack, const stack_t __user *, uss,
		stack_t __user *, uoss)
{
	struct pt_regs *regs = task_pt_regs(current);
	return do_sigaltstack(uss, uoss, regs->gprs[15]);
}

/* Returns non-zero on fault. */
static int save_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
{
	_sigregs user_sregs;

	save_access_regs(current->thread.acrs);

	/* Copy a 'clean' PSW mask to the user to avoid leaking
	   information about whether PER is currently on.  */
	user_sregs.regs.psw.mask = psw_user_bits |
		(regs->psw.mask & PSW_MASK_USER);
	user_sregs.regs.psw.addr = regs->psw.addr;
	memcpy(&user_sregs.regs.gprs, &regs->gprs, sizeof(sregs->regs.gprs));
	memcpy(&user_sregs.regs.acrs, current->thread.acrs,
	       sizeof(sregs->regs.acrs));
	/* 
	 * We have to store the fp registers to current->thread.fp_regs
	 * to merge them with the emulated registers.
	 */
	save_fp_regs(&current->thread.fp_regs);
	memcpy(&user_sregs.fpregs, &current->thread.fp_regs,
	       sizeof(s390_fp_regs));
	return __copy_to_user(sregs, &user_sregs, sizeof(_sigregs));
}

/* Returns positive number on error */
static int restore_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
{
	int err;
	_sigregs user_sregs;

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

	err = __copy_from_user(&user_sregs, sregs, sizeof(_sigregs));
	if (err)
		return err;
	/* Use regs->psw.mask instead of psw_user_bits to preserve PER bit. */
	regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
		(user_sregs.regs.psw.mask & PSW_MASK_USER);
	/* Check for invalid amode */
	if (regs->psw.mask & PSW_MASK_EA)
		regs->psw.mask |= PSW_MASK_BA;
	regs->psw.addr = user_sregs.regs.psw.addr;
	memcpy(&regs->gprs, &user_sregs.regs.gprs, sizeof(sregs->regs.gprs));
	memcpy(&current->thread.acrs, &user_sregs.regs.acrs,
	       sizeof(sregs->regs.acrs));
	restore_access_regs(current->thread.acrs);

	memcpy(&current->thread.fp_regs, &user_sregs.fpregs,
	       sizeof(s390_fp_regs));
	current->thread.fp_regs.fpc &= FPC_VALID_MASK;

	restore_fp_regs(&current->thread.fp_regs);
	clear_thread_flag(TIF_SYSCALL);	/* No longer in a system call */
	return 0;
}

SYSCALL_DEFINE0(sigreturn)
{
	struct pt_regs *regs = task_pt_regs(current);
	sigframe __user *frame = (sigframe __user *)regs->gprs[15];
	sigset_t set;

	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
		goto badframe;
	if (__copy_from_user(&set.sig, &frame->sc.oldmask, _SIGMASK_COPY_SIZE))
		goto badframe;
	set_current_blocked(&set);
	if (restore_sigregs(regs, &frame->sregs))
		goto badframe;
	return regs->gprs[2];
badframe:
	force_sig(SIGSEGV, current);
	return 0;
}

SYSCALL_DEFINE0(rt_sigreturn)
{
	struct pt_regs *regs = task_pt_regs(current);
	rt_sigframe __user *frame = (rt_sigframe __user *)regs->gprs[15];
	sigset_t set;

	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
		goto badframe;
	if (__copy_from_user(&set.sig, &frame->uc.uc_sigmask, sizeof(set)))
		goto badframe;
	set_current_blocked(&set);
	if (restore_sigregs(regs, &frame->uc.uc_mcontext))
		goto badframe;
	if (do_sigaltstack(&frame->uc.uc_stack, NULL,
			   regs->gprs[15]) == -EFAULT)
		goto badframe;
	return regs->gprs[2];
badframe:
	force_sig(SIGSEGV, current);
	return 0;
}

/*
 * Set up a signal frame.
 */


/*
 * Determine which stack to use..
 */
static inline void __user *
get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size)
{
	unsigned long sp;

	/* Default to using normal stack */
	sp = regs->gprs[15];

	/* Overflow on alternate signal stack gives SIGSEGV. */
	if (on_sig_stack(sp) && !on_sig_stack((sp - frame_size) & -8UL))
		return (void __user *) -1UL;

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

	return (void __user *)((sp - frame_size) & -8ul);
}

static inline int map_signal(int sig)
{
	if (current_thread_info()->exec_domain
	    && current_thread_info()->exec_domain->signal_invmap
	    && sig < 32)
		return current_thread_info()->exec_domain->signal_invmap[sig];
	else
		return sig;
}

static int setup_frame(int sig, struct k_sigaction *ka,
		       sigset_t *set, struct pt_regs * regs)
{
	sigframe __user *frame;

	frame = get_sigframe(ka, regs, sizeof(sigframe));
	if (!access_ok(VERIFY_WRITE, frame, sizeof(sigframe)))
		goto give_sigsegv;

	if (frame == (void __user *) -1UL)
		goto give_sigsegv;

	if (__copy_to_user(&frame->sc.oldmask, &set->sig, _SIGMASK_COPY_SIZE))
		goto give_sigsegv;

	if (save_sigregs(regs, &frame->sregs))
		goto give_sigsegv;
	if (__put_user(&frame->sregs, &frame->sc.sregs))
		goto give_sigsegv;

	/* Set up to return from userspace.  If provided, use a stub
	   already in userspace.  */
	if (ka->sa.sa_flags & SA_RESTORER) {
                regs->gprs[14] = (unsigned long)
			ka->sa.sa_restorer | PSW_ADDR_AMODE;
	} else {
                regs->gprs[14] = (unsigned long)
			frame->retcode | PSW_ADDR_AMODE;
		if (__put_user(S390_SYSCALL_OPCODE | __NR_sigreturn,
	                       (u16 __user *)(frame->retcode)))
			goto give_sigsegv;
	}

	/* Set up backchain. */
	if (__put_user(regs->gprs[15], (addr_t __user *) frame))
		goto give_sigsegv;

	/* Set up registers for signal handler */
	regs->gprs[15] = (unsigned long) frame;
	regs->psw.mask |= PSW_MASK_EA | PSW_MASK_BA;	/* 64 bit amode */
	regs->psw.addr = (unsigned long) ka->sa.sa_handler | PSW_ADDR_AMODE;

	regs->gprs[2] = map_signal(sig);
	regs->gprs[3] = (unsigned long) &frame->sc;

	/* We forgot to include these in the sigcontext.
	   To avoid breaking binary compatibility, they are passed as args. */
	if (sig == SIGSEGV || sig == SIGBUS || sig == SIGILL ||
	    sig == SIGTRAP || sig == SIGFPE) {
		/* set extra registers only for synchronous signals */
		regs->gprs[4] = regs->int_code & 127;
		regs->gprs[5] = regs->int_parm_long;
		regs->gprs[6] = task_thread_info(current)->last_break;
	}

	/* Place signal number on stack to allow backtrace from handler.  */
	if (__put_user(regs->gprs[2], (int __user *) &frame->signo))
		goto give_sigsegv;
	return 0;

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

static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
			   sigset_t *set, struct pt_regs * regs)
{
	int err = 0;
	rt_sigframe __user *frame;

	frame = get_sigframe(ka, regs, sizeof(rt_sigframe));
	if (!access_ok(VERIFY_WRITE, frame, sizeof(rt_sigframe)))
		goto give_sigsegv;

	if (frame == (void __user *) -1UL)
		goto give_sigsegv;

	if (copy_siginfo_to_user(&frame->info, info))
		goto give_sigsegv;

	/* Create the ucontext.  */
	err |= __put_user(0, &frame->uc.uc_flags);
	err |= __put_user(NULL, &frame->uc.uc_link);
	err |= __put_user((void __user *)current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
	err |= __put_user(sas_ss_flags(regs->gprs[15]),
			  &frame->uc.uc_stack.ss_flags);
	err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
	err |= save_sigregs(regs, &frame->uc.uc_mcontext);
	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
	if (err)
		goto give_sigsegv;

	/* Set up to return from userspace.  If provided, use a stub
	   already in userspace.  */
	if (ka->sa.sa_flags & SA_RESTORER) {
                regs->gprs[14] = (unsigned long)
			ka->sa.sa_restorer | PSW_ADDR_AMODE;
	} else {
                regs->gprs[14] = (unsigned long)
			frame->retcode | PSW_ADDR_AMODE;
		if (__put_user(S390_SYSCALL_OPCODE | __NR_rt_sigreturn,
			       (u16 __user *)(frame->retcode)))
			goto give_sigsegv;
	}

	/* Set up backchain. */
	if (__put_user(regs->gprs[15], (addr_t __user *) frame))
		goto give_sigsegv;

	/* Set up registers for signal handler */
	regs->gprs[15] = (unsigned long) frame;
	regs->psw.mask |= PSW_MASK_EA | PSW_MASK_BA;	/* 64 bit amode */
	regs->psw.addr = (unsigned long) ka->sa.sa_handler | PSW_ADDR_AMODE;

	regs->gprs[2] = map_signal(sig);
	regs->gprs[3] = (unsigned long) &frame->info;
	regs->gprs[4] = (unsigned long) &frame->uc;
	regs->gprs[5] = task_thread_info(current)->last_break;
	return 0;

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

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

	/* Set up the stack frame */
	if (ka->sa.sa_flags & SA_SIGINFO)
		ret = setup_rt_frame(sig, ka, info, oldset, regs);
	else
		ret = setup_frame(sig, ka, oldset, regs);
	if (ret)
		return;
	signal_delivered(sig, info, ka, regs,
				 test_thread_flag(TIF_SINGLE_STEP));
}

/*
 * 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.
 *
 * Note that we go through the signals twice: once to check the signals that
 * the kernel can handle, and then we build all the user-level signal handling
 * stack-frames in one go after that.
 */
void do_signal(struct pt_regs *regs)
{
	siginfo_t info;
	int signr;
	struct k_sigaction ka;
	sigset_t *oldset = sigmask_to_save();

	/*
	 * Get signal to deliver. When running under ptrace, at this point
	 * the debugger may change all our registers, including the system
	 * call information.
	 */
	current_thread_info()->system_call =
		test_thread_flag(TIF_SYSCALL) ? regs->int_code : 0;
	signr = get_signal_to_deliver(&info, &ka, regs, NULL);

	if (signr > 0) {
		/* Whee!  Actually deliver the signal.  */
		if (current_thread_info()->system_call) {
			regs->int_code = current_thread_info()->system_call;
			/* Check for system call restarting. */
			switch (regs->gprs[2]) {
			case -ERESTART_RESTARTBLOCK:
			case -ERESTARTNOHAND:
				regs->gprs[2] = -EINTR;
				break;
			case -ERESTARTSYS:
				if (!(ka.sa.sa_flags & SA_RESTART)) {
					regs->gprs[2] = -EINTR;
					break;
				}
			/* fallthrough */
			case -ERESTARTNOINTR:
				regs->gprs[2] = regs->orig_gpr2;
				regs->psw.addr =
					__rewind_psw(regs->psw,
						     regs->int_code >> 16);
				break;
			}
		}
		/* No longer in a system call */
		clear_thread_flag(TIF_SYSCALL);

		if (is_compat_task())
			handle_signal32(signr, &ka, &info, oldset, regs);
		else
			handle_signal(signr, &ka, &info, oldset, regs);
		return;
	}

	/* No handlers present - check for system call restart */
	clear_thread_flag(TIF_SYSCALL);
	if (current_thread_info()->system_call) {
		regs->int_code = current_thread_info()->system_call;
		switch (regs->gprs[2]) {
		case -ERESTART_RESTARTBLOCK:
			/* Restart with sys_restart_syscall */
			regs->int_code = __NR_restart_syscall;
		/* fallthrough */
		case -ERESTARTNOHAND:
		case -ERESTARTSYS:
		case -ERESTARTNOINTR:
			/* Restart system call with magic TIF bit. */
			regs->gprs[2] = regs->orig_gpr2;
			set_thread_flag(TIF_SYSCALL);
			break;
		}
	}

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

void do_notify_resume(struct pt_regs *regs)
{
	clear_thread_flag(TIF_NOTIFY_RESUME);
	tracehook_notify_resume(regs);
}
Commit	Line	Data
1da177e4	1	/*
a53c8fab	2	* Copyright IBM Corp. 1999, 2006
1da177e4 LT	3	* Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
	4	*
	5	* Based on Intel version
	6	*
	7	* Copyright (C) 1991, 1992 Linus Torvalds
	8	*
	9	* 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
	10	*/
	11
1da177e4 LT	12	#include <linux/sched.h>
	13	#include <linux/mm.h>
	14	#include <linux/smp.h>
1da177e4 LT	15	#include <linux/kernel.h>
	16	#include <linux/signal.h>
	17	#include <linux/errno.h>
	18	#include <linux/wait.h>
	19	#include <linux/ptrace.h>
	20	#include <linux/unistd.h>
	21	#include <linux/stddef.h>
	22	#include <linux/tty.h>
	23	#include <linux/personality.h>
	24	#include <linux/binfmts.h>
753c4dd6	25	#include <linux/tracehook.h>
26689452	26	#include <linux/syscalls.h>
7757591a	27	#include <linux/compat.h>
1da177e4 LT	28	#include <asm/ucontext.h>
	29	#include <asm/uaccess.h>
	30	#include <asm/lowcore.h>
a0616cde	31	#include <asm/switch_to.h>
a806170e	32	#include "entry.h"
1da177e4	33
1da177e4 LT	34	typedef struct
	35	{
	36	__u8 callee_used_stack[__SIGNAL_FRAMESIZE];
	37	struct sigcontext sc;
	38	_sigregs sregs;
	39	int signo;
	40	__u8 retcode[S390_SYSCALL_SIZE];
	41	} sigframe;
	42
	43	typedef struct
	44	{
	45	__u8 callee_used_stack[__SIGNAL_FRAMESIZE];
	46	__u8 retcode[S390_SYSCALL_SIZE];
	47	struct siginfo info;
	48	struct ucontext uc;
	49	} rt_sigframe;
	50
1da177e4 LT	51	/*
	52	* Atomically swap in the new signal mask, and wait for a signal.
	53	*/
26689452	54	SYSCALL_DEFINE3(sigsuspend, int, history0, int, history1, old_sigset_t, mask)
1da177e4	55	{
391c62fe	56	sigset_t blocked;
391c62fe	57	siginitset(&blocked, mask);
68f3f16d	58	return sigsuspend(&blocked);
1da177e4 LT	59	}
1da177e4 LT	60
26689452 HC	61	SYSCALL_DEFINE3(sigaction, int, sig, const struct old_sigaction __user *, act,
26689452 HC	62	struct old_sigaction __user *, oact)
1da177e4 LT	63	{
	64	struct k_sigaction new_ka, old_ka;
	65	int ret;
	66
	67	if (act) {
	68	old_sigset_t mask;
	69	if (!access_ok(VERIFY_READ, act, sizeof(*act)) \|\|
	70	__get_user(new_ka.sa.sa_handler, &act->sa_handler) \|\|
12bae235 HC	71	__get_user(new_ka.sa.sa_restorer, &act->sa_restorer) \|\|
	72	__get_user(new_ka.sa.sa_flags, &act->sa_flags) \|\|
	73	__get_user(mask, &act->sa_mask))
1da177e4	74	return -EFAULT;
1da177e4 LT	75	siginitset(&new_ka.sa.sa_mask, mask);
	76	}
	77
	78	ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
	79
	80	if (!ret && oact) {
	81	if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) \|\|
	82	__put_user(old_ka.sa.sa_handler, &oact->sa_handler) \|\|
12bae235 HC	83	__put_user(old_ka.sa.sa_restorer, &oact->sa_restorer) \|\|
	84	__put_user(old_ka.sa.sa_flags, &oact->sa_flags) \|\|
	85	__put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask))
1da177e4	86	return -EFAULT;
1da177e4 LT	87	}
	88
	89	return ret;
	90	}
	91
26689452 HC	92	SYSCALL_DEFINE2(sigaltstack, const stack_t __user *, uss,
26689452 HC	93	stack_t __user *, uoss)
1da177e4	94	{
03ff9a23	95	struct pt_regs *regs = task_pt_regs(current);
1da177e4 LT	96	return do_sigaltstack(uss, uoss, regs->gprs[15]);
	97	}
	98
1da177e4 LT	99	/* Returns non-zero on fault. */
	100	static int save_sigregs(struct pt_regs regs, _sigregs __user sregs)
	101	{
6837a8c3 GS	102	_sigregs user_sregs;
6837a8c3 GS	103
1da177e4 LT	104	save_access_regs(current->thread.acrs);
	105
	106	/* Copy a 'clean' PSW mask to the user to avoid leaking
	107	information about whether PER is currently on. */
d4e81b35 MS	108	user_sregs.regs.psw.mask = psw_user_bits \|
d4e81b35 MS	109	(regs->psw.mask & PSW_MASK_USER);
b05e3703 MS	110	user_sregs.regs.psw.addr = regs->psw.addr;
b05e3703 MS	111	memcpy(&user_sregs.regs.gprs, &regs->gprs, sizeof(sregs->regs.gprs));
6837a8c3 GS	112	memcpy(&user_sregs.regs.acrs, current->thread.acrs,
6837a8c3 GS	113	sizeof(sregs->regs.acrs));
1da177e4 LT	114	/*
	115	* We have to store the fp registers to current->thread.fp_regs
	116	* to merge them with the emulated registers.
	117	*/
	118	save_fp_regs(&current->thread.fp_regs);
6837a8c3 GS	119	memcpy(&user_sregs.fpregs, &current->thread.fp_regs,
	120	sizeof(s390_fp_regs));
	121	return __copy_to_user(sregs, &user_sregs, sizeof(_sigregs));
1da177e4 LT	122	}
	123
	124	/* Returns positive number on error */
	125	static int restore_sigregs(struct pt_regs regs, _sigregs __user sregs)
	126	{
1da177e4	127	int err;
6837a8c3	128	_sigregs user_sregs;
1da177e4 LT	129
	130	/* Alwys make any pending restarted system call return -EINTR */
	131	current_thread_info()->restart_block.fn = do_no_restart_syscall;
	132
6837a8c3	133	err = __copy_from_user(&user_sregs, sregs, sizeof(_sigregs));
1da177e4 LT	134	if (err)
1da177e4 LT	135	return err;
d4e81b35	136	/* Use regs->psw.mask instead of psw_user_bits to preserve PER bit. */
b50511e4	137	regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) \|
d4e81b35 MS	138	(user_sregs.regs.psw.mask & PSW_MASK_USER);
	139	/* Check for invalid amode */
	140	if (regs->psw.mask & PSW_MASK_EA)
	141	regs->psw.mask \|= PSW_MASK_BA;
	142	regs->psw.addr = user_sregs.regs.psw.addr;
b05e3703	143	memcpy(&regs->gprs, &user_sregs.regs.gprs, sizeof(sregs->regs.gprs));
6837a8c3 GS	144	memcpy(&current->thread.acrs, &user_sregs.regs.acrs,
6837a8c3 GS	145	sizeof(sregs->regs.acrs));
1da177e4 LT	146	restore_access_regs(current->thread.acrs);
1da177e4 LT	147
6837a8c3 GS	148	memcpy(&current->thread.fp_regs, &user_sregs.fpregs,
6837a8c3 GS	149	sizeof(s390_fp_regs));
1da177e4	150	current->thread.fp_regs.fpc &= FPC_VALID_MASK;
1da177e4 LT	151
1da177e4 LT	152	restore_fp_regs(&current->thread.fp_regs);
b6ef5bb3	153	clear_thread_flag(TIF_SYSCALL); /* No longer in a system call */
1da177e4 LT	154	return 0;
	155	}
	156
26689452	157	SYSCALL_DEFINE0(sigreturn)
1da177e4	158	{
03ff9a23	159	struct pt_regs *regs = task_pt_regs(current);
1da177e4 LT	160	sigframe __user frame = (sigframe __user )regs->gprs[15];
	161	sigset_t set;
	162
	163	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
	164	goto badframe;
	165	if (__copy_from_user(&set.sig, &frame->sc.oldmask, _SIGMASK_COPY_SIZE))
	166	goto badframe;
391c62fe	167	set_current_blocked(&set);
1da177e4 LT	168	if (restore_sigregs(regs, &frame->sregs))
1da177e4 LT	169	goto badframe;
1da177e4	170	return regs->gprs[2];
1da177e4 LT	171	badframe:
	172	force_sig(SIGSEGV, current);
	173	return 0;
	174	}
	175
26689452	176	SYSCALL_DEFINE0(rt_sigreturn)
1da177e4	177	{
03ff9a23	178	struct pt_regs *regs = task_pt_regs(current);
1da177e4 LT	179	rt_sigframe __user frame = (rt_sigframe __user )regs->gprs[15];
	180	sigset_t set;
	181
	182	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
	183	goto badframe;
	184	if (__copy_from_user(&set.sig, &frame->uc.uc_sigmask, sizeof(set)))
	185	goto badframe;
391c62fe	186	set_current_blocked(&set);
1da177e4 LT	187	if (restore_sigregs(regs, &frame->uc.uc_mcontext))
1da177e4 LT	188	goto badframe;
4e3df37e CLG	189	if (do_sigaltstack(&frame->uc.uc_stack, NULL,
	190	regs->gprs[15]) == -EFAULT)
	191	goto badframe;
1da177e4	192	return regs->gprs[2];
1da177e4 LT	193	badframe:
	194	force_sig(SIGSEGV, current);
	195	return 0;
	196	}
	197
	198	/*
	199	* Set up a signal frame.
	200	*/
	201
	202
	203	/*
	204	* Determine which stack to use..
	205	*/
	206	static inline void __user *
	207	get_sigframe(struct k_sigaction ka, struct pt_regs regs, size_t frame_size)
	208	{
	209	unsigned long sp;
	210
	211	/* Default to using normal stack */
	212	sp = regs->gprs[15];
	213
de553438 HC	214	/* Overflow on alternate signal stack gives SIGSEGV. */
	215	if (on_sig_stack(sp) && !on_sig_stack((sp - frame_size) & -8UL))
	216	return (void __user *) -1UL;
	217
1da177e4 LT	218	/* This is the X/Open sanctioned signal stack switching. */
	219	if (ka->sa.sa_flags & SA_ONSTACK) {
	220	if (! sas_ss_flags(sp))
	221	sp = current->sas_ss_sp + current->sas_ss_size;
	222	}
	223
1da177e4 LT	224	return (void __user *)((sp - frame_size) & -8ul);
	225	}
	226
	227	static inline int map_signal(int sig)
	228	{
	229	if (current_thread_info()->exec_domain
	230	&& current_thread_info()->exec_domain->signal_invmap
	231	&& sig < 32)
	232	return current_thread_info()->exec_domain->signal_invmap[sig];
	233	else
	234	return sig;
	235	}
	236
54dfe5dd HC	237	static int setup_frame(int sig, struct k_sigaction *ka,
54dfe5dd HC	238	sigset_t set, struct pt_regs regs)
1da177e4 LT	239	{
	240	sigframe __user *frame;
	241
	242	frame = get_sigframe(ka, regs, sizeof(sigframe));
	243	if (!access_ok(VERIFY_WRITE, frame, sizeof(sigframe)))
	244	goto give_sigsegv;
	245
de553438 HC	246	if (frame == (void __user *) -1UL)
	247	goto give_sigsegv;
	248
1da177e4 LT	249	if (__copy_to_user(&frame->sc.oldmask, &set->sig, _SIGMASK_COPY_SIZE))
	250	goto give_sigsegv;
	251
	252	if (save_sigregs(regs, &frame->sregs))
	253	goto give_sigsegv;
	254	if (__put_user(&frame->sregs, &frame->sc.sregs))
	255	goto give_sigsegv;
	256
	257	/* Set up to return from userspace. If provided, use a stub
	258	already in userspace. */
	259	if (ka->sa.sa_flags & SA_RESTORER) {
	260	regs->gprs[14] = (unsigned long)
	261	ka->sa.sa_restorer \| PSW_ADDR_AMODE;
	262	} else {
	263	regs->gprs[14] = (unsigned long)
	264	frame->retcode \| PSW_ADDR_AMODE;
	265	if (__put_user(S390_SYSCALL_OPCODE \| __NR_sigreturn,
	266	(u16 __user *)(frame->retcode)))
	267	goto give_sigsegv;
	268	}
	269
	270	/* Set up backchain. */
	271	if (__put_user(regs->gprs[15], (addr_t __user *) frame))
	272	goto give_sigsegv;
	273
	274	/* Set up registers for signal handler */
	275	regs->gprs[15] = (unsigned long) frame;
d4e81b35	276	regs->psw.mask \|= PSW_MASK_EA \| PSW_MASK_BA; /* 64 bit amode */
1da177e4 LT	277	regs->psw.addr = (unsigned long) ka->sa.sa_handler \| PSW_ADDR_AMODE;
	278
	279	regs->gprs[2] = map_signal(sig);
	280	regs->gprs[3] = (unsigned long) &frame->sc;
	281
	282	/* We forgot to include these in the sigcontext.
	283	To avoid breaking binary compatibility, they are passed as args. */
aa33c8cb MS	284	if (sig == SIGSEGV \|\| sig == SIGBUS \|\| sig == SIGILL \|\|
	285	sig == SIGTRAP \|\| sig == SIGFPE) {
	286	/* set extra registers only for synchronous signals */
	287	regs->gprs[4] = regs->int_code & 127;
	288	regs->gprs[5] = regs->int_parm_long;
	289	regs->gprs[6] = task_thread_info(current)->last_break;
	290	}
1da177e4 LT	291
	292	/* Place signal number on stack to allow backtrace from handler. */
	293	if (__put_user(regs->gprs[2], (int __user *) &frame->signo))
	294	goto give_sigsegv;
54dfe5dd	295	return 0;
1da177e4 LT	296
	297	give_sigsegv:
	298	force_sigsegv(sig, current);
54dfe5dd	299	return -EFAULT;
1da177e4 LT	300	}
1da177e4 LT	301
54dfe5dd	302	static int setup_rt_frame(int sig, struct k_sigaction ka, siginfo_t info,
1da177e4 LT	303	sigset_t set, struct pt_regs regs)
	304	{
	305	int err = 0;
	306	rt_sigframe __user *frame;
	307
	308	frame = get_sigframe(ka, regs, sizeof(rt_sigframe));
	309	if (!access_ok(VERIFY_WRITE, frame, sizeof(rt_sigframe)))
	310	goto give_sigsegv;
	311
de553438 HC	312	if (frame == (void __user *) -1UL)
	313	goto give_sigsegv;
	314
1da177e4 LT	315	if (copy_siginfo_to_user(&frame->info, info))
	316	goto give_sigsegv;
	317
	318	/* Create the ucontext. */
	319	err \|= __put_user(0, &frame->uc.uc_flags);
c2814476 AV	320	err \|= __put_user(NULL, &frame->uc.uc_link);
c2814476 AV	321	err \|= __put_user((void __user *)current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
1da177e4 LT	322	err \|= __put_user(sas_ss_flags(regs->gprs[15]),
	323	&frame->uc.uc_stack.ss_flags);
	324	err \|= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
	325	err \|= save_sigregs(regs, &frame->uc.uc_mcontext);
	326	err \|= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
	327	if (err)
	328	goto give_sigsegv;
	329
	330	/* Set up to return from userspace. If provided, use a stub
	331	already in userspace. */
	332	if (ka->sa.sa_flags & SA_RESTORER) {
	333	regs->gprs[14] = (unsigned long)
	334	ka->sa.sa_restorer \| PSW_ADDR_AMODE;
	335	} else {
	336	regs->gprs[14] = (unsigned long)
	337	frame->retcode \| PSW_ADDR_AMODE;
b44df334 HC	338	if (__put_user(S390_SYSCALL_OPCODE \| __NR_rt_sigreturn,
	339	(u16 __user *)(frame->retcode)))
	340	goto give_sigsegv;
1da177e4 LT	341	}
	342
	343	/* Set up backchain. */
	344	if (__put_user(regs->gprs[15], (addr_t __user *) frame))
	345	goto give_sigsegv;
	346
	347	/* Set up registers for signal handler */
	348	regs->gprs[15] = (unsigned long) frame;
d4e81b35	349	regs->psw.mask \|= PSW_MASK_EA \| PSW_MASK_BA; /* 64 bit amode */
1da177e4 LT	350	regs->psw.addr = (unsigned long) ka->sa.sa_handler \| PSW_ADDR_AMODE;
	351
	352	regs->gprs[2] = map_signal(sig);
	353	regs->gprs[3] = (unsigned long) &frame->info;
	354	regs->gprs[4] = (unsigned long) &frame->uc;
86f2552b	355	regs->gprs[5] = task_thread_info(current)->last_break;
54dfe5dd	356	return 0;
1da177e4 LT	357
	358	give_sigsegv:
	359	force_sigsegv(sig, current);
54dfe5dd	360	return -EFAULT;
1da177e4 LT	361	}
1da177e4 LT	362
a610d6e6	363	static void handle_signal(unsigned long sig, struct k_sigaction *ka,
391c62fe HC	364	siginfo_t info, sigset_t oldset,
391c62fe HC	365	struct pt_regs *regs)
1da177e4	366	{
54dfe5dd HC	367	int ret;
54dfe5dd HC	368
1da177e4 LT	369	/* Set up the stack frame */
1da177e4 LT	370	if (ka->sa.sa_flags & SA_SIGINFO)
54dfe5dd	371	ret = setup_rt_frame(sig, ka, info, oldset, regs);
1da177e4	372	else
54dfe5dd	373	ret = setup_frame(sig, ka, oldset, regs);
391c62fe	374	if (ret)
a610d6e6	375	return;
efee984c	376	signal_delivered(sig, info, ka, regs,
a610d6e6	377	test_thread_flag(TIF_SINGLE_STEP));
1da177e4 LT	378	}
	379
	380	/*
	381	* Note that 'init' is a special process: it doesn't get signals it doesn't
	382	* want to handle. Thus you cannot kill init even with a SIGKILL even by
	383	* mistake.
	384	*
	385	* Note that we go through the signals twice: once to check the signals that
	386	* the kernel can handle, and then we build all the user-level signal handling
	387	* stack-frames in one go after that.
	388	*/
54dfe5dd	389	void do_signal(struct pt_regs *regs)
1da177e4	390	{
1da177e4 LT	391	siginfo_t info;
	392	int signr;
	393	struct k_sigaction ka;
b7f9a11a	394	sigset_t *oldset = sigmask_to_save();
1da177e4	395
20b40a79 MS	396	/*
	397	* Get signal to deliver. When running under ptrace, at this point
	398	* the debugger may change all our registers, including the system
	399	* call information.
	400	*/
b6ef5bb3	401	current_thread_info()->system_call =
aa33c8cb	402	test_thread_flag(TIF_SYSCALL) ? regs->int_code : 0;
1da177e4	403	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
1da177e4 LT	404
	405	if (signr > 0) {
	406	/* Whee! Actually deliver the signal. */
b6ef5bb3	407	if (current_thread_info()->system_call) {
aa33c8cb	408	regs->int_code = current_thread_info()->system_call;
20b40a79 MS	409	/* Check for system call restarting. */
	410	switch (regs->gprs[2]) {
	411	case -ERESTART_RESTARTBLOCK:
	412	case -ERESTARTNOHAND:
	413	regs->gprs[2] = -EINTR;
	414	break;
	415	case -ERESTARTSYS:
	416	if (!(ka.sa.sa_flags & SA_RESTART)) {
	417	regs->gprs[2] = -EINTR;
	418	break;
	419	}
	420	/* fallthrough */
	421	case -ERESTARTNOINTR:
	422	regs->gprs[2] = regs->orig_gpr2;
ccf45caf MS	423	regs->psw.addr =
ccf45caf MS	424	__rewind_psw(regs->psw,
aa33c8cb	425	regs->int_code >> 16);
20b40a79 MS	426	break;
20b40a79 MS	427	}
20b40a79	428	}
d9ae6772 MS	429	/* No longer in a system call */
d9ae6772 MS	430	clear_thread_flag(TIF_SYSCALL);
20b40a79	431
a610d6e6 AV	432	if (is_compat_task())
	433	handle_signal32(signr, &ka, &info, oldset, regs);
	434	else
	435	handle_signal(signr, &ka, &info, oldset, regs);
54dfe5dd HC	436	return;
	437	}
	438
20b40a79	439	/* No handlers present - check for system call restart */
d9ae6772	440	clear_thread_flag(TIF_SYSCALL);
b6ef5bb3	441	if (current_thread_info()->system_call) {
aa33c8cb	442	regs->int_code = current_thread_info()->system_call;
20b40a79 MS	443	switch (regs->gprs[2]) {
	444	case -ERESTART_RESTARTBLOCK:
	445	/* Restart with sys_restart_syscall */
aa33c8cb	446	regs->int_code = __NR_restart_syscall;
20b40a79 MS	447	/* fallthrough */
	448	case -ERESTARTNOHAND:
	449	case -ERESTARTSYS:
	450	case -ERESTARTNOINTR:
	451	/* Restart system call with magic TIF bit. */
	452	regs->gprs[2] = regs->orig_gpr2;
b6ef5bb3 MS	453	set_thread_flag(TIF_SYSCALL);
b6ef5bb3 MS	454	break;
20b40a79 MS	455	}
	456	}
	457
54dfe5dd HC	458	/*
	459	* If there's no signal to deliver, we just put the saved sigmask back.
	460	*/
51a7b448	461	restore_saved_sigmask();
1da177e4	462	}
753c4dd6 MS	463
	464	void do_notify_resume(struct pt_regs *regs)
	465	{
	466	clear_thread_flag(TIF_NOTIFY_RESUME);
	467	tracehook_notify_resume(regs);
	468	}