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

/*
 *  arch/s390/kernel/signal.c
 *
 *    Copyright (C) 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"

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


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;
	sigdelsetmask(&set, ~_BLOCKABLE);
	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;
	sigdelsetmask(&set, ~_BLOCKABLE);
	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 int 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 ret;
	block_sigmask(ka, sig);
	return 0;
}

/*
 * 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;

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

	/*
	 * 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) :
		     handle_signal(signr, &ka, &info, 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.
			 */
			if (test_thread_flag(TIF_RESTORE_SIGMASK))
				clear_thread_flag(TIF_RESTORE_SIGMASK);

			/*
			 * Let tracing know that we've done the handler setup.
			 */
			tracehook_signal_handler(signr, &info, &ka, regs,
					 test_thread_flag(TIF_SINGLE_STEP));
		}
		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 LT	1	/*
	2	* arch/s390/kernel/signal.c
	3	*
54dfe5dd	4	* Copyright (C) IBM Corp. 1999,2006
1da177e4 LT	5	* Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
	6	*
	7	* Based on Intel version
	8	*
	9	* Copyright (C) 1991, 1992 Linus Torvalds
	10	*
	11	* 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
	12	*/
	13
1da177e4 LT	14	#include <linux/sched.h>
	15	#include <linux/mm.h>
	16	#include <linux/smp.h>
1da177e4 LT	17	#include <linux/kernel.h>
	18	#include <linux/signal.h>
	19	#include <linux/errno.h>
	20	#include <linux/wait.h>
	21	#include <linux/ptrace.h>
	22	#include <linux/unistd.h>
	23	#include <linux/stddef.h>
	24	#include <linux/tty.h>
	25	#include <linux/personality.h>
	26	#include <linux/binfmts.h>
753c4dd6	27	#include <linux/tracehook.h>
26689452	28	#include <linux/syscalls.h>
7757591a	29	#include <linux/compat.h>
1da177e4 LT	30	#include <asm/ucontext.h>
	31	#include <asm/uaccess.h>
	32	#include <asm/lowcore.h>
a0616cde	33	#include <asm/switch_to.h>
a806170e	34	#include "entry.h"
1da177e4 LT	35
	36	#define _BLOCKABLE (~(sigmask(SIGKILL) \| sigmask(SIGSTOP)))
	37
	38
	39	typedef struct
	40	{
	41	__u8 callee_used_stack[__SIGNAL_FRAMESIZE];
	42	struct sigcontext sc;
	43	_sigregs sregs;
	44	int signo;
	45	__u8 retcode[S390_SYSCALL_SIZE];
	46	} sigframe;
	47
	48	typedef struct
	49	{
	50	__u8 callee_used_stack[__SIGNAL_FRAMESIZE];
	51	__u8 retcode[S390_SYSCALL_SIZE];
	52	struct siginfo info;
	53	struct ucontext uc;
	54	} rt_sigframe;
	55
1da177e4 LT	56	/*
	57	* Atomically swap in the new signal mask, and wait for a signal.
	58	*/
26689452	59	SYSCALL_DEFINE3(sigsuspend, int, history0, int, history1, old_sigset_t, mask)
1da177e4	60	{
391c62fe	61	sigset_t blocked;
391c62fe	62	siginitset(&blocked, mask);
68f3f16d	63	return sigsuspend(&blocked);
1da177e4 LT	64	}
1da177e4 LT	65
26689452 HC	66	SYSCALL_DEFINE3(sigaction, int, sig, const struct old_sigaction __user *, act,
26689452 HC	67	struct old_sigaction __user *, oact)
1da177e4 LT	68	{
	69	struct k_sigaction new_ka, old_ka;
	70	int ret;
	71
	72	if (act) {
	73	old_sigset_t mask;
	74	if (!access_ok(VERIFY_READ, act, sizeof(*act)) \|\|
	75	__get_user(new_ka.sa.sa_handler, &act->sa_handler) \|\|
12bae235 HC	76	__get_user(new_ka.sa.sa_restorer, &act->sa_restorer) \|\|
	77	__get_user(new_ka.sa.sa_flags, &act->sa_flags) \|\|
	78	__get_user(mask, &act->sa_mask))
1da177e4	79	return -EFAULT;
1da177e4 LT	80	siginitset(&new_ka.sa.sa_mask, mask);
	81	}
	82
	83	ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
	84
	85	if (!ret && oact) {
	86	if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) \|\|
	87	__put_user(old_ka.sa.sa_handler, &oact->sa_handler) \|\|
12bae235 HC	88	__put_user(old_ka.sa.sa_restorer, &oact->sa_restorer) \|\|
	89	__put_user(old_ka.sa.sa_flags, &oact->sa_flags) \|\|
	90	__put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask))
1da177e4	91	return -EFAULT;
1da177e4 LT	92	}
	93
	94	return ret;
	95	}
	96
26689452 HC	97	SYSCALL_DEFINE2(sigaltstack, const stack_t __user *, uss,
26689452 HC	98	stack_t __user *, uoss)
1da177e4	99	{
03ff9a23	100	struct pt_regs *regs = task_pt_regs(current);
1da177e4 LT	101	return do_sigaltstack(uss, uoss, regs->gprs[15]);
	102	}
	103
1da177e4 LT	104	/* Returns non-zero on fault. */
	105	static int save_sigregs(struct pt_regs regs, _sigregs __user sregs)
	106	{
6837a8c3 GS	107	_sigregs user_sregs;
6837a8c3 GS	108
1da177e4 LT	109	save_access_regs(current->thread.acrs);
	110
	111	/* Copy a 'clean' PSW mask to the user to avoid leaking
	112	information about whether PER is currently on. */
d4e81b35 MS	113	user_sregs.regs.psw.mask = psw_user_bits \|
d4e81b35 MS	114	(regs->psw.mask & PSW_MASK_USER);
b05e3703 MS	115	user_sregs.regs.psw.addr = regs->psw.addr;
b05e3703 MS	116	memcpy(&user_sregs.regs.gprs, &regs->gprs, sizeof(sregs->regs.gprs));
6837a8c3 GS	117	memcpy(&user_sregs.regs.acrs, current->thread.acrs,
6837a8c3 GS	118	sizeof(sregs->regs.acrs));
1da177e4 LT	119	/*
	120	* We have to store the fp registers to current->thread.fp_regs
	121	* to merge them with the emulated registers.
	122	*/
	123	save_fp_regs(&current->thread.fp_regs);
6837a8c3 GS	124	memcpy(&user_sregs.fpregs, &current->thread.fp_regs,
	125	sizeof(s390_fp_regs));
	126	return __copy_to_user(sregs, &user_sregs, sizeof(_sigregs));
1da177e4 LT	127	}
	128
	129	/* Returns positive number on error */
	130	static int restore_sigregs(struct pt_regs regs, _sigregs __user sregs)
	131	{
1da177e4	132	int err;
6837a8c3	133	_sigregs user_sregs;
1da177e4 LT	134
	135	/* Alwys make any pending restarted system call return -EINTR */
	136	current_thread_info()->restart_block.fn = do_no_restart_syscall;
	137
6837a8c3	138	err = __copy_from_user(&user_sregs, sregs, sizeof(_sigregs));
1da177e4 LT	139	if (err)
1da177e4 LT	140	return err;
d4e81b35	141	/* Use regs->psw.mask instead of psw_user_bits to preserve PER bit. */
b50511e4	142	regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) \|
d4e81b35 MS	143	(user_sregs.regs.psw.mask & PSW_MASK_USER);
	144	/* Check for invalid amode */
	145	if (regs->psw.mask & PSW_MASK_EA)
	146	regs->psw.mask \|= PSW_MASK_BA;
	147	regs->psw.addr = user_sregs.regs.psw.addr;
b05e3703	148	memcpy(&regs->gprs, &user_sregs.regs.gprs, sizeof(sregs->regs.gprs));
6837a8c3 GS	149	memcpy(&current->thread.acrs, &user_sregs.regs.acrs,
6837a8c3 GS	150	sizeof(sregs->regs.acrs));
1da177e4 LT	151	restore_access_regs(current->thread.acrs);
1da177e4 LT	152
6837a8c3 GS	153	memcpy(&current->thread.fp_regs, &user_sregs.fpregs,
6837a8c3 GS	154	sizeof(s390_fp_regs));
1da177e4	155	current->thread.fp_regs.fpc &= FPC_VALID_MASK;
1da177e4 LT	156
1da177e4 LT	157	restore_fp_regs(&current->thread.fp_regs);
b6ef5bb3	158	clear_thread_flag(TIF_SYSCALL); /* No longer in a system call */
1da177e4 LT	159	return 0;
	160	}
	161
26689452	162	SYSCALL_DEFINE0(sigreturn)
1da177e4	163	{
03ff9a23	164	struct pt_regs *regs = task_pt_regs(current);
1da177e4 LT	165	sigframe __user frame = (sigframe __user )regs->gprs[15];
	166	sigset_t set;
	167
	168	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
	169	goto badframe;
	170	if (__copy_from_user(&set.sig, &frame->sc.oldmask, _SIGMASK_COPY_SIZE))
	171	goto badframe;
1da177e4	172	sigdelsetmask(&set, ~_BLOCKABLE);
391c62fe	173	set_current_blocked(&set);
1da177e4 LT	174	if (restore_sigregs(regs, &frame->sregs))
1da177e4 LT	175	goto badframe;
1da177e4	176	return regs->gprs[2];
1da177e4 LT	177	badframe:
	178	force_sig(SIGSEGV, current);
	179	return 0;
	180	}
	181
26689452	182	SYSCALL_DEFINE0(rt_sigreturn)
1da177e4	183	{
03ff9a23	184	struct pt_regs *regs = task_pt_regs(current);
1da177e4 LT	185	rt_sigframe __user frame = (rt_sigframe __user )regs->gprs[15];
	186	sigset_t set;
	187
	188	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
	189	goto badframe;
	190	if (__copy_from_user(&set.sig, &frame->uc.uc_sigmask, sizeof(set)))
	191	goto badframe;
1da177e4	192	sigdelsetmask(&set, ~_BLOCKABLE);
391c62fe	193	set_current_blocked(&set);
1da177e4 LT	194	if (restore_sigregs(regs, &frame->uc.uc_mcontext))
1da177e4 LT	195	goto badframe;
4e3df37e CLG	196	if (do_sigaltstack(&frame->uc.uc_stack, NULL,
	197	regs->gprs[15]) == -EFAULT)
	198	goto badframe;
1da177e4	199	return regs->gprs[2];
1da177e4 LT	200	badframe:
	201	force_sig(SIGSEGV, current);
	202	return 0;
	203	}
	204
	205	/*
	206	* Set up a signal frame.
	207	*/
	208
	209
	210	/*
	211	* Determine which stack to use..
	212	*/
	213	static inline void __user *
	214	get_sigframe(struct k_sigaction ka, struct pt_regs regs, size_t frame_size)
	215	{
	216	unsigned long sp;
	217
	218	/* Default to using normal stack */
	219	sp = regs->gprs[15];
	220
de553438 HC	221	/* Overflow on alternate signal stack gives SIGSEGV. */
	222	if (on_sig_stack(sp) && !on_sig_stack((sp - frame_size) & -8UL))
	223	return (void __user *) -1UL;
	224
1da177e4 LT	225	/* This is the X/Open sanctioned signal stack switching. */
	226	if (ka->sa.sa_flags & SA_ONSTACK) {
	227	if (! sas_ss_flags(sp))
	228	sp = current->sas_ss_sp + current->sas_ss_size;
	229	}
	230
1da177e4 LT	231	return (void __user *)((sp - frame_size) & -8ul);
	232	}
	233
	234	static inline int map_signal(int sig)
	235	{
	236	if (current_thread_info()->exec_domain
	237	&& current_thread_info()->exec_domain->signal_invmap
	238	&& sig < 32)
	239	return current_thread_info()->exec_domain->signal_invmap[sig];
	240	else
	241	return sig;
	242	}
	243
54dfe5dd HC	244	static int setup_frame(int sig, struct k_sigaction *ka,
54dfe5dd HC	245	sigset_t set, struct pt_regs regs)
1da177e4 LT	246	{
	247	sigframe __user *frame;
	248
	249	frame = get_sigframe(ka, regs, sizeof(sigframe));
	250	if (!access_ok(VERIFY_WRITE, frame, sizeof(sigframe)))
	251	goto give_sigsegv;
	252
de553438 HC	253	if (frame == (void __user *) -1UL)
	254	goto give_sigsegv;
	255
1da177e4 LT	256	if (__copy_to_user(&frame->sc.oldmask, &set->sig, _SIGMASK_COPY_SIZE))
	257	goto give_sigsegv;
	258
	259	if (save_sigregs(regs, &frame->sregs))
	260	goto give_sigsegv;
	261	if (__put_user(&frame->sregs, &frame->sc.sregs))
	262	goto give_sigsegv;
	263
	264	/* Set up to return from userspace. If provided, use a stub
	265	already in userspace. */
	266	if (ka->sa.sa_flags & SA_RESTORER) {
	267	regs->gprs[14] = (unsigned long)
	268	ka->sa.sa_restorer \| PSW_ADDR_AMODE;
	269	} else {
	270	regs->gprs[14] = (unsigned long)
	271	frame->retcode \| PSW_ADDR_AMODE;
	272	if (__put_user(S390_SYSCALL_OPCODE \| __NR_sigreturn,
	273	(u16 __user *)(frame->retcode)))
	274	goto give_sigsegv;
	275	}
	276
	277	/* Set up backchain. */
	278	if (__put_user(regs->gprs[15], (addr_t __user *) frame))
	279	goto give_sigsegv;
	280
	281	/* Set up registers for signal handler */
	282	regs->gprs[15] = (unsigned long) frame;
d4e81b35	283	regs->psw.mask \|= PSW_MASK_EA \| PSW_MASK_BA; /* 64 bit amode */
1da177e4 LT	284	regs->psw.addr = (unsigned long) ka->sa.sa_handler \| PSW_ADDR_AMODE;
	285
	286	regs->gprs[2] = map_signal(sig);
	287	regs->gprs[3] = (unsigned long) &frame->sc;
	288
	289	/* We forgot to include these in the sigcontext.
	290	To avoid breaking binary compatibility, they are passed as args. */
aa33c8cb MS	291	if (sig == SIGSEGV \|\| sig == SIGBUS \|\| sig == SIGILL \|\|
	292	sig == SIGTRAP \|\| sig == SIGFPE) {
	293	/* set extra registers only for synchronous signals */
	294	regs->gprs[4] = regs->int_code & 127;
	295	regs->gprs[5] = regs->int_parm_long;
	296	regs->gprs[6] = task_thread_info(current)->last_break;
	297	}
1da177e4 LT	298
	299	/* Place signal number on stack to allow backtrace from handler. */
	300	if (__put_user(regs->gprs[2], (int __user *) &frame->signo))
	301	goto give_sigsegv;
54dfe5dd	302	return 0;
1da177e4 LT	303
	304	give_sigsegv:
	305	force_sigsegv(sig, current);
54dfe5dd	306	return -EFAULT;
1da177e4 LT	307	}
1da177e4 LT	308
54dfe5dd	309	static int setup_rt_frame(int sig, struct k_sigaction ka, siginfo_t info,
1da177e4 LT	310	sigset_t set, struct pt_regs regs)
	311	{
	312	int err = 0;
	313	rt_sigframe __user *frame;
	314
	315	frame = get_sigframe(ka, regs, sizeof(rt_sigframe));
	316	if (!access_ok(VERIFY_WRITE, frame, sizeof(rt_sigframe)))
	317	goto give_sigsegv;
	318
de553438 HC	319	if (frame == (void __user *) -1UL)
	320	goto give_sigsegv;
	321
1da177e4 LT	322	if (copy_siginfo_to_user(&frame->info, info))
	323	goto give_sigsegv;
	324
	325	/* Create the ucontext. */
	326	err \|= __put_user(0, &frame->uc.uc_flags);
c2814476 AV	327	err \|= __put_user(NULL, &frame->uc.uc_link);
c2814476 AV	328	err \|= __put_user((void __user *)current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
1da177e4 LT	329	err \|= __put_user(sas_ss_flags(regs->gprs[15]),
	330	&frame->uc.uc_stack.ss_flags);
	331	err \|= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
	332	err \|= save_sigregs(regs, &frame->uc.uc_mcontext);
	333	err \|= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
	334	if (err)
	335	goto give_sigsegv;
	336
	337	/* Set up to return from userspace. If provided, use a stub
	338	already in userspace. */
	339	if (ka->sa.sa_flags & SA_RESTORER) {
	340	regs->gprs[14] = (unsigned long)
	341	ka->sa.sa_restorer \| PSW_ADDR_AMODE;
	342	} else {
	343	regs->gprs[14] = (unsigned long)
	344	frame->retcode \| PSW_ADDR_AMODE;
b44df334 HC	345	if (__put_user(S390_SYSCALL_OPCODE \| __NR_rt_sigreturn,
	346	(u16 __user *)(frame->retcode)))
	347	goto give_sigsegv;
1da177e4 LT	348	}
	349
	350	/* Set up backchain. */
	351	if (__put_user(regs->gprs[15], (addr_t __user *) frame))
	352	goto give_sigsegv;
	353
	354	/* Set up registers for signal handler */
	355	regs->gprs[15] = (unsigned long) frame;
d4e81b35	356	regs->psw.mask \|= PSW_MASK_EA \| PSW_MASK_BA; /* 64 bit amode */
1da177e4 LT	357	regs->psw.addr = (unsigned long) ka->sa.sa_handler \| PSW_ADDR_AMODE;
	358
	359	regs->gprs[2] = map_signal(sig);
	360	regs->gprs[3] = (unsigned long) &frame->info;
	361	regs->gprs[4] = (unsigned long) &frame->uc;
86f2552b	362	regs->gprs[5] = task_thread_info(current)->last_break;
54dfe5dd	363	return 0;
1da177e4 LT	364
	365	give_sigsegv:
	366	force_sigsegv(sig, current);
54dfe5dd	367	return -EFAULT;
1da177e4 LT	368	}
1da177e4 LT	369
391c62fe HC	370	static int handle_signal(unsigned long sig, struct k_sigaction *ka,
	371	siginfo_t info, sigset_t oldset,
	372	struct pt_regs *regs)
1da177e4	373	{
54dfe5dd HC	374	int ret;
54dfe5dd HC	375
1da177e4 LT	376	/* Set up the stack frame */
1da177e4 LT	377	if (ka->sa.sa_flags & SA_SIGINFO)
54dfe5dd	378	ret = setup_rt_frame(sig, ka, info, oldset, regs);
1da177e4	379	else
54dfe5dd	380	ret = setup_frame(sig, ka, oldset, regs);
391c62fe HC	381	if (ret)
391c62fe HC	382	return ret;
ad252ffa	383	block_sigmask(ka, sig);
391c62fe	384	return 0;
1da177e4 LT	385	}
	386
	387	/*
	388	* Note that 'init' is a special process: it doesn't get signals it doesn't
	389	* want to handle. Thus you cannot kill init even with a SIGKILL even by
	390	* mistake.
	391	*
	392	* Note that we go through the signals twice: once to check the signals that
	393	* the kernel can handle, and then we build all the user-level signal handling
	394	* stack-frames in one go after that.
	395	*/
54dfe5dd	396	void do_signal(struct pt_regs *regs)
1da177e4	397	{
1da177e4 LT	398	siginfo_t info;
	399	int signr;
	400	struct k_sigaction ka;
54dfe5dd	401	sigset_t *oldset;
1da177e4	402
54dfe5dd HC	403	if (test_thread_flag(TIF_RESTORE_SIGMASK))
	404	oldset = &current->saved_sigmask;
	405	else
1da177e4 LT	406	oldset = &current->blocked;
1da177e4 LT	407
20b40a79 MS	408	/*
	409	* Get signal to deliver. When running under ptrace, at this point
	410	* the debugger may change all our registers, including the system
	411	* call information.
	412	*/
b6ef5bb3	413	current_thread_info()->system_call =
aa33c8cb	414	test_thread_flag(TIF_SYSCALL) ? regs->int_code : 0;
1da177e4	415	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
1da177e4 LT	416
	417	if (signr > 0) {
	418	/* Whee! Actually deliver the signal. */
b6ef5bb3	419	if (current_thread_info()->system_call) {
aa33c8cb	420	regs->int_code = current_thread_info()->system_call;
20b40a79 MS	421	/* Check for system call restarting. */
	422	switch (regs->gprs[2]) {
	423	case -ERESTART_RESTARTBLOCK:
	424	case -ERESTARTNOHAND:
	425	regs->gprs[2] = -EINTR;
	426	break;
	427	case -ERESTARTSYS:
	428	if (!(ka.sa.sa_flags & SA_RESTART)) {
	429	regs->gprs[2] = -EINTR;
	430	break;
	431	}
	432	/* fallthrough */
	433	case -ERESTARTNOINTR:
	434	regs->gprs[2] = regs->orig_gpr2;
ccf45caf MS	435	regs->psw.addr =
ccf45caf MS	436	__rewind_psw(regs->psw,
aa33c8cb	437	regs->int_code >> 16);
20b40a79 MS	438	break;
20b40a79 MS	439	}
20b40a79	440	}
d9ae6772 MS	441	/* No longer in a system call */
d9ae6772 MS	442	clear_thread_flag(TIF_SYSCALL);
20b40a79 MS	443
	444	if ((is_compat_task() ?
	445	handle_signal32(signr, &ka, &info, oldset, regs) :
	446	handle_signal(signr, &ka, &info, oldset, regs)) == 0) {
54dfe5dd HC	447	/*
	448	* A signal was successfully delivered; the saved
	449	* sigmask will have been stored in the signal frame,
	450	* and will be restored by sigreturn, so we can simply
	451	* clear the TIF_RESTORE_SIGMASK flag.
	452	*/
	453	if (test_thread_flag(TIF_RESTORE_SIGMASK))
	454	clear_thread_flag(TIF_RESTORE_SIGMASK);
0ac30be4	455
753c4dd6 MS	456	/*
	457	* Let tracing know that we've done the handler setup.
	458	*/
	459	tracehook_signal_handler(signr, &info, &ka, regs,
20b40a79	460	test_thread_flag(TIF_SINGLE_STEP));
54dfe5dd HC	461	}
	462	return;
	463	}
	464
20b40a79	465	/* No handlers present - check for system call restart */
d9ae6772	466	clear_thread_flag(TIF_SYSCALL);
b6ef5bb3	467	if (current_thread_info()->system_call) {
aa33c8cb	468	regs->int_code = current_thread_info()->system_call;
20b40a79 MS	469	switch (regs->gprs[2]) {
	470	case -ERESTART_RESTARTBLOCK:
	471	/* Restart with sys_restart_syscall */
aa33c8cb	472	regs->int_code = __NR_restart_syscall;
20b40a79 MS	473	/* fallthrough */
	474	case -ERESTARTNOHAND:
	475	case -ERESTARTSYS:
	476	case -ERESTARTNOINTR:
	477	/* Restart system call with magic TIF bit. */
	478	regs->gprs[2] = regs->orig_gpr2;
b6ef5bb3 MS	479	set_thread_flag(TIF_SYSCALL);
b6ef5bb3 MS	480	break;
20b40a79 MS	481	}
	482	}
	483
54dfe5dd HC	484	/*
	485	* If there's no signal to deliver, we just put the saved sigmask back.
	486	*/
51a7b448	487	restore_saved_sigmask();
1da177e4	488	}
753c4dd6 MS	489
	490	void do_notify_resume(struct pt_regs *regs)
	491	{
	492	clear_thread_flag(TIF_NOTIFY_RESUME);
	493	tracehook_notify_resume(regs);
	494	}