[mirror_ubuntu-zesty-kernel.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/compat.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;

	current->saved_sigmask = current->blocked;
	mask &= _BLOCKABLE;
	siginitset(&blocked, mask);
	set_current_blocked(&blocked);
	set_current_state(TASK_INTERRUPTIBLE);
	schedule();
	set_restore_sigmask();
	return -ERESTARTNOHAND;
}

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_MASK_MERGE(psw_user_bits, regs->psw.mask);
	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;
	regs->psw.mask = PSW_MASK_MERGE(regs->psw.mask,
					user_sregs.regs.psw.mask);
	regs->psw.addr = PSW_ADDR_AMODE | 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);
	regs->svc_code = 0;	/* disable syscall checks */
	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;
	}

	/* This is the legacy signal stack switching. */
	else if (!user_mode(regs) &&
		 !(ka->sa.sa_flags & SA_RESTORER) &&
		 ka->sa.sa_restorer) {
		sp = (unsigned long) ka->sa.sa_restorer;
	}

	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.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. */
	regs->gprs[4] = current->thread.trap_no;
	regs->gprs[5] = current->thread.prot_addr;
	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.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)
{
	sigset_t blocked;
	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;
	sigorsets(&blocked, &current->blocked, &ka->sa.sa_mask);
	if (!(ka->sa.sa_flags & SA_NODEFER))
		sigaddset(&blocked, sig);
	set_current_blocked(&blocked);
	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;

	/*
	 * 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;

	/*
	 * 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 = regs->svc_code;
	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
	regs->svc_code = current_thread_info()->system_call;

	if (signr > 0) {
		/* Whee!  Actually deliver the signal.  */
		if (regs->svc_code > 0) {
			/* 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->svc_code >> 16);
				break;
			}
			/* No longer in a system call */
			regs->svc_code = 0;
		}

		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 */
	if (regs->svc_code > 0) {
		switch (regs->gprs[2]) {
		case -ERESTART_RESTARTBLOCK:
			/* Restart with sys_restart_syscall */
			regs->svc_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_RESTART_SVC);
			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)
{
	clear_thread_flag(TIF_NOTIFY_RESUME);
	tracehook_notify_resume(regs);
	if (current->replacement_session_keyring)
		key_replace_session_keyring();
}
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>
20b40a79	33	#include <asm/compat.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;
1da177e4	62
391c62fe HC	63	current->saved_sigmask = current->blocked;
	64	mask &= _BLOCKABLE;
	65	siginitset(&blocked, mask);
	66	set_current_blocked(&blocked);
0b4d7890	67	set_current_state(TASK_INTERRUPTIBLE);
54dfe5dd	68	schedule();
9e8ed3ae	69	set_restore_sigmask();
54dfe5dd	70	return -ERESTARTNOHAND;
1da177e4 LT	71	}
1da177e4 LT	72
26689452 HC	73	SYSCALL_DEFINE3(sigaction, int, sig, const struct old_sigaction __user *, act,
26689452 HC	74	struct old_sigaction __user *, oact)
1da177e4 LT	75	{
	76	struct k_sigaction new_ka, old_ka;
	77	int ret;
	78
	79	if (act) {
	80	old_sigset_t mask;
	81	if (!access_ok(VERIFY_READ, act, sizeof(*act)) \|\|
	82	__get_user(new_ka.sa.sa_handler, &act->sa_handler) \|\|
12bae235 HC	83	__get_user(new_ka.sa.sa_restorer, &act->sa_restorer) \|\|
	84	__get_user(new_ka.sa.sa_flags, &act->sa_flags) \|\|
	85	__get_user(mask, &act->sa_mask))
1da177e4	86	return -EFAULT;
1da177e4 LT	87	siginitset(&new_ka.sa.sa_mask, mask);
	88	}
	89
	90	ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
	91
	92	if (!ret && oact) {
	93	if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) \|\|
	94	__put_user(old_ka.sa.sa_handler, &oact->sa_handler) \|\|
12bae235 HC	95	__put_user(old_ka.sa.sa_restorer, &oact->sa_restorer) \|\|
	96	__put_user(old_ka.sa.sa_flags, &oact->sa_flags) \|\|
	97	__put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask))
1da177e4	98	return -EFAULT;
1da177e4 LT	99	}
	100
	101	return ret;
	102	}
	103
26689452 HC	104	SYSCALL_DEFINE2(sigaltstack, const stack_t __user *, uss,
26689452 HC	105	stack_t __user *, uoss)
1da177e4	106	{
03ff9a23	107	struct pt_regs *regs = task_pt_regs(current);
1da177e4 LT	108	return do_sigaltstack(uss, uoss, regs->gprs[15]);
	109	}
	110
1da177e4 LT	111	/* Returns non-zero on fault. */
	112	static int save_sigregs(struct pt_regs regs, _sigregs __user sregs)
	113	{
6837a8c3 GS	114	_sigregs user_sregs;
6837a8c3 GS	115
1da177e4 LT	116	save_access_regs(current->thread.acrs);
	117
	118	/* Copy a 'clean' PSW mask to the user to avoid leaking
	119	information about whether PER is currently on. */
c1821c2e	120	user_sregs.regs.psw.mask = PSW_MASK_MERGE(psw_user_bits, regs->psw.mask);
b05e3703 MS	121	user_sregs.regs.psw.addr = regs->psw.addr;
b05e3703 MS	122	memcpy(&user_sregs.regs.gprs, &regs->gprs, sizeof(sregs->regs.gprs));
6837a8c3 GS	123	memcpy(&user_sregs.regs.acrs, current->thread.acrs,
6837a8c3 GS	124	sizeof(sregs->regs.acrs));
1da177e4 LT	125	/*
	126	* We have to store the fp registers to current->thread.fp_regs
	127	* to merge them with the emulated registers.
	128	*/
	129	save_fp_regs(&current->thread.fp_regs);
6837a8c3 GS	130	memcpy(&user_sregs.fpregs, &current->thread.fp_regs,
	131	sizeof(s390_fp_regs));
	132	return __copy_to_user(sregs, &user_sregs, sizeof(_sigregs));
1da177e4 LT	133	}
	134
	135	/* Returns positive number on error */
	136	static int restore_sigregs(struct pt_regs regs, _sigregs __user sregs)
	137	{
1da177e4	138	int err;
6837a8c3	139	_sigregs user_sregs;
1da177e4 LT	140
	141	/* Alwys make any pending restarted system call return -EINTR */
	142	current_thread_info()->restart_block.fn = do_no_restart_syscall;
	143
6837a8c3	144	err = __copy_from_user(&user_sregs, sregs, sizeof(_sigregs));
1da177e4 LT	145	if (err)
1da177e4 LT	146	return err;
b05e3703 MS	147	regs->psw.mask = PSW_MASK_MERGE(regs->psw.mask,
	148	user_sregs.regs.psw.mask);
	149	regs->psw.addr = PSW_ADDR_AMODE \| user_sregs.regs.psw.addr;
	150	memcpy(&regs->gprs, &user_sregs.regs.gprs, sizeof(sregs->regs.gprs));
6837a8c3 GS	151	memcpy(&current->thread.acrs, &user_sregs.regs.acrs,
6837a8c3 GS	152	sizeof(sregs->regs.acrs));
1da177e4 LT	153	restore_access_regs(current->thread.acrs);
1da177e4 LT	154
6837a8c3 GS	155	memcpy(&current->thread.fp_regs, &user_sregs.fpregs,
6837a8c3 GS	156	sizeof(s390_fp_regs));
1da177e4	157	current->thread.fp_regs.fpc &= FPC_VALID_MASK;
1da177e4 LT	158
1da177e4 LT	159	restore_fp_regs(&current->thread.fp_regs);
20b40a79	160	regs->svc_code = 0; /* disable syscall checks */
1da177e4 LT	161	return 0;
	162	}
	163
26689452	164	SYSCALL_DEFINE0(sigreturn)
1da177e4	165	{
03ff9a23	166	struct pt_regs *regs = task_pt_regs(current);
1da177e4 LT	167	sigframe __user frame = (sigframe __user )regs->gprs[15];
	168	sigset_t set;
	169
	170	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
	171	goto badframe;
	172	if (__copy_from_user(&set.sig, &frame->sc.oldmask, _SIGMASK_COPY_SIZE))
	173	goto badframe;
1da177e4	174	sigdelsetmask(&set, ~_BLOCKABLE);
391c62fe	175	set_current_blocked(&set);
1da177e4 LT	176	if (restore_sigregs(regs, &frame->sregs))
1da177e4 LT	177	goto badframe;
1da177e4	178	return regs->gprs[2];
1da177e4 LT	179	badframe:
	180	force_sig(SIGSEGV, current);
	181	return 0;
	182	}
	183
26689452	184	SYSCALL_DEFINE0(rt_sigreturn)
1da177e4	185	{
03ff9a23	186	struct pt_regs *regs = task_pt_regs(current);
1da177e4 LT	187	rt_sigframe __user frame = (rt_sigframe __user )regs->gprs[15];
	188	sigset_t set;
	189
	190	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
	191	goto badframe;
	192	if (__copy_from_user(&set.sig, &frame->uc.uc_sigmask, sizeof(set)))
	193	goto badframe;
1da177e4	194	sigdelsetmask(&set, ~_BLOCKABLE);
391c62fe	195	set_current_blocked(&set);
1da177e4 LT	196	if (restore_sigregs(regs, &frame->uc.uc_mcontext))
1da177e4 LT	197	goto badframe;
4e3df37e CLG	198	if (do_sigaltstack(&frame->uc.uc_stack, NULL,
	199	regs->gprs[15]) == -EFAULT)
	200	goto badframe;
1da177e4	201	return regs->gprs[2];
1da177e4 LT	202	badframe:
	203	force_sig(SIGSEGV, current);
	204	return 0;
	205	}
	206
	207	/*
	208	* Set up a signal frame.
	209	*/
	210
	211
	212	/*
	213	* Determine which stack to use..
	214	*/
	215	static inline void __user *
	216	get_sigframe(struct k_sigaction ka, struct pt_regs regs, size_t frame_size)
	217	{
	218	unsigned long sp;
	219
	220	/* Default to using normal stack */
	221	sp = regs->gprs[15];
	222
de553438 HC	223	/* Overflow on alternate signal stack gives SIGSEGV. */
	224	if (on_sig_stack(sp) && !on_sig_stack((sp - frame_size) & -8UL))
	225	return (void __user *) -1UL;
	226
1da177e4 LT	227	/* This is the X/Open sanctioned signal stack switching. */
	228	if (ka->sa.sa_flags & SA_ONSTACK) {
	229	if (! sas_ss_flags(sp))
	230	sp = current->sas_ss_sp + current->sas_ss_size;
	231	}
	232
	233	/* This is the legacy signal stack switching. */
	234	else if (!user_mode(regs) &&
	235	!(ka->sa.sa_flags & SA_RESTORER) &&
	236	ka->sa.sa_restorer) {
	237	sp = (unsigned long) ka->sa.sa_restorer;
	238	}
	239
	240	return (void __user *)((sp - frame_size) & -8ul);
	241	}
	242
	243	static inline int map_signal(int sig)
	244	{
	245	if (current_thread_info()->exec_domain
	246	&& current_thread_info()->exec_domain->signal_invmap
	247	&& sig < 32)
	248	return current_thread_info()->exec_domain->signal_invmap[sig];
	249	else
	250	return sig;
	251	}
	252
54dfe5dd HC	253	static int setup_frame(int sig, struct k_sigaction *ka,
54dfe5dd HC	254	sigset_t set, struct pt_regs regs)
1da177e4 LT	255	{
	256	sigframe __user *frame;
	257
	258	frame = get_sigframe(ka, regs, sizeof(sigframe));
	259	if (!access_ok(VERIFY_WRITE, frame, sizeof(sigframe)))
	260	goto give_sigsegv;
	261
de553438 HC	262	if (frame == (void __user *) -1UL)
	263	goto give_sigsegv;
	264
1da177e4 LT	265	if (__copy_to_user(&frame->sc.oldmask, &set->sig, _SIGMASK_COPY_SIZE))
	266	goto give_sigsegv;
	267
	268	if (save_sigregs(regs, &frame->sregs))
	269	goto give_sigsegv;
	270	if (__put_user(&frame->sregs, &frame->sc.sregs))
	271	goto give_sigsegv;
	272
	273	/* Set up to return from userspace. If provided, use a stub
	274	already in userspace. */
	275	if (ka->sa.sa_flags & SA_RESTORER) {
	276	regs->gprs[14] = (unsigned long)
	277	ka->sa.sa_restorer \| PSW_ADDR_AMODE;
	278	} else {
	279	regs->gprs[14] = (unsigned long)
	280	frame->retcode \| PSW_ADDR_AMODE;
	281	if (__put_user(S390_SYSCALL_OPCODE \| __NR_sigreturn,
	282	(u16 __user *)(frame->retcode)))
	283	goto give_sigsegv;
	284	}
	285
	286	/* Set up backchain. */
	287	if (__put_user(regs->gprs[15], (addr_t __user *) frame))
	288	goto give_sigsegv;
	289
	290	/* Set up registers for signal handler */
	291	regs->gprs[15] = (unsigned long) frame;
	292	regs->psw.addr = (unsigned long) ka->sa.sa_handler \| PSW_ADDR_AMODE;
	293
	294	regs->gprs[2] = map_signal(sig);
	295	regs->gprs[3] = (unsigned long) &frame->sc;
	296
	297	/* We forgot to include these in the sigcontext.
	298	To avoid breaking binary compatibility, they are passed as args. */
	299	regs->gprs[4] = current->thread.trap_no;
	300	regs->gprs[5] = current->thread.prot_addr;
86f2552b	301	regs->gprs[6] = task_thread_info(current)->last_break;
1da177e4 LT	302
	303	/* Place signal number on stack to allow backtrace from handler. */
	304	if (__put_user(regs->gprs[2], (int __user *) &frame->signo))
	305	goto give_sigsegv;
54dfe5dd	306	return 0;
1da177e4 LT	307
	308	give_sigsegv:
	309	force_sigsegv(sig, current);
54dfe5dd	310	return -EFAULT;
1da177e4 LT	311	}
1da177e4 LT	312
54dfe5dd	313	static int setup_rt_frame(int sig, struct k_sigaction ka, siginfo_t info,
1da177e4 LT	314	sigset_t set, struct pt_regs regs)
	315	{
	316	int err = 0;
	317	rt_sigframe __user *frame;
	318
	319	frame = get_sigframe(ka, regs, sizeof(rt_sigframe));
	320	if (!access_ok(VERIFY_WRITE, frame, sizeof(rt_sigframe)))
	321	goto give_sigsegv;
	322
de553438 HC	323	if (frame == (void __user *) -1UL)
	324	goto give_sigsegv;
	325
1da177e4 LT	326	if (copy_siginfo_to_user(&frame->info, info))
	327	goto give_sigsegv;
	328
	329	/* Create the ucontext. */
	330	err \|= __put_user(0, &frame->uc.uc_flags);
c2814476 AV	331	err \|= __put_user(NULL, &frame->uc.uc_link);
c2814476 AV	332	err \|= __put_user((void __user *)current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
1da177e4 LT	333	err \|= __put_user(sas_ss_flags(regs->gprs[15]),
	334	&frame->uc.uc_stack.ss_flags);
	335	err \|= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
	336	err \|= save_sigregs(regs, &frame->uc.uc_mcontext);
	337	err \|= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
	338	if (err)
	339	goto give_sigsegv;
	340
	341	/* Set up to return from userspace. If provided, use a stub
	342	already in userspace. */
	343	if (ka->sa.sa_flags & SA_RESTORER) {
	344	regs->gprs[14] = (unsigned long)
	345	ka->sa.sa_restorer \| PSW_ADDR_AMODE;
	346	} else {
	347	regs->gprs[14] = (unsigned long)
	348	frame->retcode \| PSW_ADDR_AMODE;
b44df334 HC	349	if (__put_user(S390_SYSCALL_OPCODE \| __NR_rt_sigreturn,
	350	(u16 __user *)(frame->retcode)))
	351	goto give_sigsegv;
1da177e4 LT	352	}
	353
	354	/* Set up backchain. */
	355	if (__put_user(regs->gprs[15], (addr_t __user *) frame))
	356	goto give_sigsegv;
	357
	358	/* Set up registers for signal handler */
	359	regs->gprs[15] = (unsigned long) frame;
	360	regs->psw.addr = (unsigned long) ka->sa.sa_handler \| PSW_ADDR_AMODE;
	361
	362	regs->gprs[2] = map_signal(sig);
	363	regs->gprs[3] = (unsigned long) &frame->info;
	364	regs->gprs[4] = (unsigned long) &frame->uc;
86f2552b	365	regs->gprs[5] = task_thread_info(current)->last_break;
54dfe5dd	366	return 0;
1da177e4 LT	367
	368	give_sigsegv:
	369	force_sigsegv(sig, current);
54dfe5dd	370	return -EFAULT;
1da177e4 LT	371	}
1da177e4 LT	372
391c62fe HC	373	static int handle_signal(unsigned long sig, struct k_sigaction *ka,
	374	siginfo_t info, sigset_t oldset,
	375	struct pt_regs *regs)
1da177e4	376	{
391c62fe	377	sigset_t blocked;
54dfe5dd HC	378	int ret;
54dfe5dd HC	379
1da177e4 LT	380	/* Set up the stack frame */
1da177e4 LT	381	if (ka->sa.sa_flags & SA_SIGINFO)
54dfe5dd	382	ret = setup_rt_frame(sig, ka, info, oldset, regs);
1da177e4	383	else
54dfe5dd	384	ret = setup_frame(sig, ka, oldset, regs);
391c62fe HC	385	if (ret)
	386	return ret;
	387	sigorsets(&blocked, &current->blocked, &ka->sa.sa_mask);
	388	if (!(ka->sa.sa_flags & SA_NODEFER))
	389	sigaddset(&blocked, sig);
	390	set_current_blocked(&blocked);
	391	return 0;
1da177e4 LT	392	}
	393
	394	/*
	395	* Note that 'init' is a special process: it doesn't get signals it doesn't
	396	* want to handle. Thus you cannot kill init even with a SIGKILL even by
	397	* mistake.
	398	*
	399	* Note that we go through the signals twice: once to check the signals that
	400	* the kernel can handle, and then we build all the user-level signal handling
	401	* stack-frames in one go after that.
	402	*/
54dfe5dd	403	void do_signal(struct pt_regs *regs)
1da177e4	404	{
1da177e4 LT	405	siginfo_t info;
	406	int signr;
	407	struct k_sigaction ka;
54dfe5dd	408	sigset_t *oldset;
1da177e4 LT	409
	410	/*
	411	* We want the common case to go fast, which
	412	* is why we may in certain cases get here from
	413	* kernel mode. Just return without doing anything
	414	* if so.
	415	*/
	416	if (!user_mode(regs))
54dfe5dd	417	return;
1da177e4	418
54dfe5dd HC	419	if (test_thread_flag(TIF_RESTORE_SIGMASK))
	420	oldset = &current->saved_sigmask;
	421	else
1da177e4 LT	422	oldset = &current->blocked;
1da177e4 LT	423
20b40a79 MS	424	/*
	425	* Get signal to deliver. When running under ptrace, at this point
	426	* the debugger may change all our registers, including the system
	427	* call information.
	428	*/
	429	current_thread_info()->system_call = regs->svc_code;
1da177e4	430	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
20b40a79	431	regs->svc_code = current_thread_info()->system_call;
1da177e4 LT	432
	433	if (signr > 0) {
	434	/* Whee! Actually deliver the signal. */
20b40a79 MS	435	if (regs->svc_code > 0) {
	436	/* Check for system call restarting. */
	437	switch (regs->gprs[2]) {
	438	case -ERESTART_RESTARTBLOCK:
	439	case -ERESTARTNOHAND:
	440	regs->gprs[2] = -EINTR;
	441	break;
	442	case -ERESTARTSYS:
	443	if (!(ka.sa.sa_flags & SA_RESTART)) {
	444	regs->gprs[2] = -EINTR;
	445	break;
	446	}
	447	/* fallthrough */
	448	case -ERESTARTNOINTR:
	449	regs->gprs[2] = regs->orig_gpr2;
ccf45caf MS	450	regs->psw.addr =
	451	__rewind_psw(regs->psw,
	452	regs->svc_code >> 16);
20b40a79 MS	453	break;
	454	}
	455	/* No longer in a system call */
	456	regs->svc_code = 0;
	457	}
	458
	459	if ((is_compat_task() ?
	460	handle_signal32(signr, &ka, &info, oldset, regs) :
	461	handle_signal(signr, &ka, &info, oldset, regs)) == 0) {
54dfe5dd HC	462	/*
	463	* A signal was successfully delivered; the saved
	464	* sigmask will have been stored in the signal frame,
	465	* and will be restored by sigreturn, so we can simply
	466	* clear the TIF_RESTORE_SIGMASK flag.
	467	*/
	468	if (test_thread_flag(TIF_RESTORE_SIGMASK))
	469	clear_thread_flag(TIF_RESTORE_SIGMASK);
0ac30be4	470
753c4dd6 MS	471	/*
	472	* Let tracing know that we've done the handler setup.
	473	*/
	474	tracehook_signal_handler(signr, &info, &ka, regs,
20b40a79	475	test_thread_flag(TIF_SINGLE_STEP));
54dfe5dd HC	476	}
	477	return;
	478	}
	479
20b40a79 MS	480	/* No handlers present - check for system call restart */
	481	if (regs->svc_code > 0) {
	482	switch (regs->gprs[2]) {
	483	case -ERESTART_RESTARTBLOCK:
	484	/* Restart with sys_restart_syscall */
	485	regs->svc_code = __NR_restart_syscall;
	486	/* fallthrough */
	487	case -ERESTARTNOHAND:
	488	case -ERESTARTSYS:
	489	case -ERESTARTNOINTR:
	490	/* Restart system call with magic TIF bit. */
	491	regs->gprs[2] = regs->orig_gpr2;
	492	set_thread_flag(TIF_RESTART_SVC);
	493	break;
	494	}
	495	}
	496
54dfe5dd HC	497	/*
	498	* If there's no signal to deliver, we just put the saved sigmask back.
	499	*/
	500	if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
	501	clear_thread_flag(TIF_RESTORE_SIGMASK);
	502	sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
1da177e4	503	}
1da177e4	504	}
753c4dd6 MS	505
	506	void do_notify_resume(struct pt_regs *regs)
	507	{
	508	clear_thread_flag(TIF_NOTIFY_RESUME);
	509	tracehook_notify_resume(regs);
ee18d64c DH	510	if (current->replacement_session_keyring)
ee18d64c DH	511	key_replace_session_keyring();
753c4dd6	512	}