[GitHub/mt8127/android_kernel_alcatel_ttab.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"

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;
	block_sigmask(ka, sig);
	/*
	 * Let tracing know that we've done the handler setup.
	 */
	tracehook_signal_handler(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 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	35
1da177e4 LT	36	typedef struct
	37	{
	38	__u8 callee_used_stack[__SIGNAL_FRAMESIZE];
	39	struct sigcontext sc;
	40	_sigregs sregs;
	41	int signo;
	42	__u8 retcode[S390_SYSCALL_SIZE];
	43	} sigframe;
	44
	45	typedef struct
	46	{
	47	__u8 callee_used_stack[__SIGNAL_FRAMESIZE];
	48	__u8 retcode[S390_SYSCALL_SIZE];
	49	struct siginfo info;
	50	struct ucontext uc;
	51	} rt_sigframe;
	52
1da177e4 LT	53	/*
	54	* Atomically swap in the new signal mask, and wait for a signal.
	55	*/
26689452	56	SYSCALL_DEFINE3(sigsuspend, int, history0, int, history1, old_sigset_t, mask)
1da177e4	57	{
391c62fe	58	sigset_t blocked;
391c62fe	59	siginitset(&blocked, mask);
68f3f16d	60	return sigsuspend(&blocked);
1da177e4 LT	61	}
1da177e4 LT	62
26689452 HC	63	SYSCALL_DEFINE3(sigaction, int, sig, const struct old_sigaction __user *, act,
26689452 HC	64	struct old_sigaction __user *, oact)
1da177e4 LT	65	{
	66	struct k_sigaction new_ka, old_ka;
	67	int ret;
	68
	69	if (act) {
	70	old_sigset_t mask;
	71	if (!access_ok(VERIFY_READ, act, sizeof(*act)) \|\|
	72	__get_user(new_ka.sa.sa_handler, &act->sa_handler) \|\|
12bae235 HC	73	__get_user(new_ka.sa.sa_restorer, &act->sa_restorer) \|\|
	74	__get_user(new_ka.sa.sa_flags, &act->sa_flags) \|\|
	75	__get_user(mask, &act->sa_mask))
1da177e4	76	return -EFAULT;
1da177e4 LT	77	siginitset(&new_ka.sa.sa_mask, mask);
	78	}
	79
	80	ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
	81
	82	if (!ret && oact) {
	83	if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) \|\|
	84	__put_user(old_ka.sa.sa_handler, &oact->sa_handler) \|\|
12bae235 HC	85	__put_user(old_ka.sa.sa_restorer, &oact->sa_restorer) \|\|
	86	__put_user(old_ka.sa.sa_flags, &oact->sa_flags) \|\|
	87	__put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask))
1da177e4	88	return -EFAULT;
1da177e4 LT	89	}
	90
	91	return ret;
	92	}
	93
26689452 HC	94	SYSCALL_DEFINE2(sigaltstack, const stack_t __user *, uss,
26689452 HC	95	stack_t __user *, uoss)
1da177e4	96	{
03ff9a23	97	struct pt_regs *regs = task_pt_regs(current);
1da177e4 LT	98	return do_sigaltstack(uss, uoss, regs->gprs[15]);
	99	}
	100
1da177e4 LT	101	/* Returns non-zero on fault. */
	102	static int save_sigregs(struct pt_regs regs, _sigregs __user sregs)
	103	{
6837a8c3 GS	104	_sigregs user_sregs;
6837a8c3 GS	105
1da177e4 LT	106	save_access_regs(current->thread.acrs);
	107
	108	/* Copy a 'clean' PSW mask to the user to avoid leaking
	109	information about whether PER is currently on. */
d4e81b35 MS	110	user_sregs.regs.psw.mask = psw_user_bits \|
d4e81b35 MS	111	(regs->psw.mask & PSW_MASK_USER);
b05e3703 MS	112	user_sregs.regs.psw.addr = regs->psw.addr;
b05e3703 MS	113	memcpy(&user_sregs.regs.gprs, &regs->gprs, sizeof(sregs->regs.gprs));
6837a8c3 GS	114	memcpy(&user_sregs.regs.acrs, current->thread.acrs,
6837a8c3 GS	115	sizeof(sregs->regs.acrs));
1da177e4 LT	116	/*
	117	* We have to store the fp registers to current->thread.fp_regs
	118	* to merge them with the emulated registers.
	119	*/
	120	save_fp_regs(&current->thread.fp_regs);
6837a8c3 GS	121	memcpy(&user_sregs.fpregs, &current->thread.fp_regs,
	122	sizeof(s390_fp_regs));
	123	return __copy_to_user(sregs, &user_sregs, sizeof(_sigregs));
1da177e4 LT	124	}
	125
	126	/* Returns positive number on error */
	127	static int restore_sigregs(struct pt_regs regs, _sigregs __user sregs)
	128	{
1da177e4	129	int err;
6837a8c3	130	_sigregs user_sregs;
1da177e4 LT	131
	132	/* Alwys make any pending restarted system call return -EINTR */
	133	current_thread_info()->restart_block.fn = do_no_restart_syscall;
	134
6837a8c3	135	err = __copy_from_user(&user_sregs, sregs, sizeof(_sigregs));
1da177e4 LT	136	if (err)
1da177e4 LT	137	return err;
d4e81b35	138	/* Use regs->psw.mask instead of psw_user_bits to preserve PER bit. */
b50511e4	139	regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) \|
d4e81b35 MS	140	(user_sregs.regs.psw.mask & PSW_MASK_USER);
	141	/* Check for invalid amode */
	142	if (regs->psw.mask & PSW_MASK_EA)
	143	regs->psw.mask \|= PSW_MASK_BA;
	144	regs->psw.addr = user_sregs.regs.psw.addr;
b05e3703	145	memcpy(&regs->gprs, &user_sregs.regs.gprs, sizeof(sregs->regs.gprs));
6837a8c3 GS	146	memcpy(&current->thread.acrs, &user_sregs.regs.acrs,
6837a8c3 GS	147	sizeof(sregs->regs.acrs));
1da177e4 LT	148	restore_access_regs(current->thread.acrs);
1da177e4 LT	149
6837a8c3 GS	150	memcpy(&current->thread.fp_regs, &user_sregs.fpregs,
6837a8c3 GS	151	sizeof(s390_fp_regs));
1da177e4	152	current->thread.fp_regs.fpc &= FPC_VALID_MASK;
1da177e4 LT	153
1da177e4 LT	154	restore_fp_regs(&current->thread.fp_regs);
b6ef5bb3	155	clear_thread_flag(TIF_SYSCALL); /* No longer in a system call */
1da177e4 LT	156	return 0;
	157	}
	158
26689452	159	SYSCALL_DEFINE0(sigreturn)
1da177e4	160	{
03ff9a23	161	struct pt_regs *regs = task_pt_regs(current);
1da177e4 LT	162	sigframe __user frame = (sigframe __user )regs->gprs[15];
	163	sigset_t set;
	164
	165	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
	166	goto badframe;
	167	if (__copy_from_user(&set.sig, &frame->sc.oldmask, _SIGMASK_COPY_SIZE))
	168	goto badframe;
391c62fe	169	set_current_blocked(&set);
1da177e4 LT	170	if (restore_sigregs(regs, &frame->sregs))
1da177e4 LT	171	goto badframe;
1da177e4	172	return regs->gprs[2];
1da177e4 LT	173	badframe:
	174	force_sig(SIGSEGV, current);
	175	return 0;
	176	}
	177
26689452	178	SYSCALL_DEFINE0(rt_sigreturn)
1da177e4	179	{
03ff9a23	180	struct pt_regs *regs = task_pt_regs(current);
1da177e4 LT	181	rt_sigframe __user frame = (rt_sigframe __user )regs->gprs[15];
	182	sigset_t set;
	183
	184	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
	185	goto badframe;
	186	if (__copy_from_user(&set.sig, &frame->uc.uc_sigmask, sizeof(set)))
	187	goto badframe;
391c62fe	188	set_current_blocked(&set);
1da177e4 LT	189	if (restore_sigregs(regs, &frame->uc.uc_mcontext))
1da177e4 LT	190	goto badframe;
4e3df37e CLG	191	if (do_sigaltstack(&frame->uc.uc_stack, NULL,
	192	regs->gprs[15]) == -EFAULT)
	193	goto badframe;
1da177e4	194	return regs->gprs[2];
1da177e4 LT	195	badframe:
	196	force_sig(SIGSEGV, current);
	197	return 0;
	198	}
	199
	200	/*
	201	* Set up a signal frame.
	202	*/
	203
	204
	205	/*
	206	* Determine which stack to use..
	207	*/
	208	static inline void __user *
	209	get_sigframe(struct k_sigaction ka, struct pt_regs regs, size_t frame_size)
	210	{
	211	unsigned long sp;
	212
	213	/* Default to using normal stack */
	214	sp = regs->gprs[15];
	215
de553438 HC	216	/* Overflow on alternate signal stack gives SIGSEGV. */
	217	if (on_sig_stack(sp) && !on_sig_stack((sp - frame_size) & -8UL))
	218	return (void __user *) -1UL;
	219
1da177e4 LT	220	/* This is the X/Open sanctioned signal stack switching. */
	221	if (ka->sa.sa_flags & SA_ONSTACK) {
	222	if (! sas_ss_flags(sp))
	223	sp = current->sas_ss_sp + current->sas_ss_size;
	224	}
	225
1da177e4 LT	226	return (void __user *)((sp - frame_size) & -8ul);
	227	}
	228
	229	static inline int map_signal(int sig)
	230	{
	231	if (current_thread_info()->exec_domain
	232	&& current_thread_info()->exec_domain->signal_invmap
	233	&& sig < 32)
	234	return current_thread_info()->exec_domain->signal_invmap[sig];
	235	else
	236	return sig;
	237	}
	238
54dfe5dd HC	239	static int setup_frame(int sig, struct k_sigaction *ka,
54dfe5dd HC	240	sigset_t set, struct pt_regs regs)
1da177e4 LT	241	{
	242	sigframe __user *frame;
	243
	244	frame = get_sigframe(ka, regs, sizeof(sigframe));
	245	if (!access_ok(VERIFY_WRITE, frame, sizeof(sigframe)))
	246	goto give_sigsegv;
	247
de553438 HC	248	if (frame == (void __user *) -1UL)
	249	goto give_sigsegv;
	250
1da177e4 LT	251	if (__copy_to_user(&frame->sc.oldmask, &set->sig, _SIGMASK_COPY_SIZE))
	252	goto give_sigsegv;
	253
	254	if (save_sigregs(regs, &frame->sregs))
	255	goto give_sigsegv;
	256	if (__put_user(&frame->sregs, &frame->sc.sregs))
	257	goto give_sigsegv;
	258
	259	/* Set up to return from userspace. If provided, use a stub
	260	already in userspace. */
	261	if (ka->sa.sa_flags & SA_RESTORER) {
	262	regs->gprs[14] = (unsigned long)
	263	ka->sa.sa_restorer \| PSW_ADDR_AMODE;
	264	} else {
	265	regs->gprs[14] = (unsigned long)
	266	frame->retcode \| PSW_ADDR_AMODE;
	267	if (__put_user(S390_SYSCALL_OPCODE \| __NR_sigreturn,
	268	(u16 __user *)(frame->retcode)))
	269	goto give_sigsegv;
	270	}
	271
	272	/* Set up backchain. */
	273	if (__put_user(regs->gprs[15], (addr_t __user *) frame))
	274	goto give_sigsegv;
	275
	276	/* Set up registers for signal handler */
	277	regs->gprs[15] = (unsigned long) frame;
d4e81b35	278	regs->psw.mask \|= PSW_MASK_EA \| PSW_MASK_BA; /* 64 bit amode */
1da177e4 LT	279	regs->psw.addr = (unsigned long) ka->sa.sa_handler \| PSW_ADDR_AMODE;
	280
	281	regs->gprs[2] = map_signal(sig);
	282	regs->gprs[3] = (unsigned long) &frame->sc;
	283
	284	/* We forgot to include these in the sigcontext.
	285	To avoid breaking binary compatibility, they are passed as args. */
aa33c8cb MS	286	if (sig == SIGSEGV \|\| sig == SIGBUS \|\| sig == SIGILL \|\|
	287	sig == SIGTRAP \|\| sig == SIGFPE) {
	288	/* set extra registers only for synchronous signals */
	289	regs->gprs[4] = regs->int_code & 127;
	290	regs->gprs[5] = regs->int_parm_long;
	291	regs->gprs[6] = task_thread_info(current)->last_break;
	292	}
1da177e4 LT	293
	294	/* Place signal number on stack to allow backtrace from handler. */
	295	if (__put_user(regs->gprs[2], (int __user *) &frame->signo))
	296	goto give_sigsegv;
54dfe5dd	297	return 0;
1da177e4 LT	298
	299	give_sigsegv:
	300	force_sigsegv(sig, current);
54dfe5dd	301	return -EFAULT;
1da177e4 LT	302	}
1da177e4 LT	303
54dfe5dd	304	static int setup_rt_frame(int sig, struct k_sigaction ka, siginfo_t info,
1da177e4 LT	305	sigset_t set, struct pt_regs regs)
	306	{
	307	int err = 0;
	308	rt_sigframe __user *frame;
	309
	310	frame = get_sigframe(ka, regs, sizeof(rt_sigframe));
	311	if (!access_ok(VERIFY_WRITE, frame, sizeof(rt_sigframe)))
	312	goto give_sigsegv;
	313
de553438 HC	314	if (frame == (void __user *) -1UL)
	315	goto give_sigsegv;
	316
1da177e4 LT	317	if (copy_siginfo_to_user(&frame->info, info))
	318	goto give_sigsegv;
	319
	320	/* Create the ucontext. */
	321	err \|= __put_user(0, &frame->uc.uc_flags);
c2814476 AV	322	err \|= __put_user(NULL, &frame->uc.uc_link);
c2814476 AV	323	err \|= __put_user((void __user *)current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
1da177e4 LT	324	err \|= __put_user(sas_ss_flags(regs->gprs[15]),
	325	&frame->uc.uc_stack.ss_flags);
	326	err \|= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
	327	err \|= save_sigregs(regs, &frame->uc.uc_mcontext);
	328	err \|= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
	329	if (err)
	330	goto give_sigsegv;
	331
	332	/* Set up to return from userspace. If provided, use a stub
	333	already in userspace. */
	334	if (ka->sa.sa_flags & SA_RESTORER) {
	335	regs->gprs[14] = (unsigned long)
	336	ka->sa.sa_restorer \| PSW_ADDR_AMODE;
	337	} else {
	338	regs->gprs[14] = (unsigned long)
	339	frame->retcode \| PSW_ADDR_AMODE;
b44df334 HC	340	if (__put_user(S390_SYSCALL_OPCODE \| __NR_rt_sigreturn,
	341	(u16 __user *)(frame->retcode)))
	342	goto give_sigsegv;
1da177e4 LT	343	}
	344
	345	/* Set up backchain. */
	346	if (__put_user(regs->gprs[15], (addr_t __user *) frame))
	347	goto give_sigsegv;
	348
	349	/* Set up registers for signal handler */
	350	regs->gprs[15] = (unsigned long) frame;
d4e81b35	351	regs->psw.mask \|= PSW_MASK_EA \| PSW_MASK_BA; /* 64 bit amode */
1da177e4 LT	352	regs->psw.addr = (unsigned long) ka->sa.sa_handler \| PSW_ADDR_AMODE;
	353
	354	regs->gprs[2] = map_signal(sig);
	355	regs->gprs[3] = (unsigned long) &frame->info;
	356	regs->gprs[4] = (unsigned long) &frame->uc;
86f2552b	357	regs->gprs[5] = task_thread_info(current)->last_break;
54dfe5dd	358	return 0;
1da177e4 LT	359
	360	give_sigsegv:
	361	force_sigsegv(sig, current);
54dfe5dd	362	return -EFAULT;
1da177e4 LT	363	}
1da177e4 LT	364
a610d6e6	365	static void handle_signal(unsigned long sig, struct k_sigaction *ka,
391c62fe HC	366	siginfo_t info, sigset_t oldset,
391c62fe HC	367	struct pt_regs *regs)
1da177e4	368	{
54dfe5dd HC	369	int ret;
54dfe5dd HC	370
1da177e4 LT	371	/* Set up the stack frame */
1da177e4 LT	372	if (ka->sa.sa_flags & SA_SIGINFO)
54dfe5dd	373	ret = setup_rt_frame(sig, ka, info, oldset, regs);
1da177e4	374	else
54dfe5dd	375	ret = setup_frame(sig, ka, oldset, regs);
391c62fe	376	if (ret)
a610d6e6	377	return;
ad252ffa	378	block_sigmask(ka, sig);
a610d6e6 AV	379	/*
	380	* Let tracing know that we've done the handler setup.
	381	*/
	382	tracehook_signal_handler(sig, info, ka, regs,
	383	test_thread_flag(TIF_SINGLE_STEP));
1da177e4 LT	384	}
	385
	386	/*
	387	* Note that 'init' is a special process: it doesn't get signals it doesn't
	388	* want to handle. Thus you cannot kill init even with a SIGKILL even by
	389	* mistake.
	390	*
	391	* Note that we go through the signals twice: once to check the signals that
	392	* the kernel can handle, and then we build all the user-level signal handling
	393	* stack-frames in one go after that.
	394	*/
54dfe5dd	395	void do_signal(struct pt_regs *regs)
1da177e4	396	{
1da177e4 LT	397	siginfo_t info;
	398	int signr;
	399	struct k_sigaction ka;
b7f9a11a	400	sigset_t *oldset = sigmask_to_save();
1da177e4	401
20b40a79 MS	402	/*
	403	* Get signal to deliver. When running under ptrace, at this point
	404	* the debugger may change all our registers, including the system
	405	* call information.
	406	*/
b6ef5bb3	407	current_thread_info()->system_call =
aa33c8cb	408	test_thread_flag(TIF_SYSCALL) ? regs->int_code : 0;
1da177e4	409	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
1da177e4 LT	410
	411	if (signr > 0) {
	412	/* Whee! Actually deliver the signal. */
b6ef5bb3	413	if (current_thread_info()->system_call) {
aa33c8cb	414	regs->int_code = current_thread_info()->system_call;
20b40a79 MS	415	/* Check for system call restarting. */
	416	switch (regs->gprs[2]) {
	417	case -ERESTART_RESTARTBLOCK:
	418	case -ERESTARTNOHAND:
	419	regs->gprs[2] = -EINTR;
	420	break;
	421	case -ERESTARTSYS:
	422	if (!(ka.sa.sa_flags & SA_RESTART)) {
	423	regs->gprs[2] = -EINTR;
	424	break;
	425	}
	426	/* fallthrough */
	427	case -ERESTARTNOINTR:
	428	regs->gprs[2] = regs->orig_gpr2;
ccf45caf MS	429	regs->psw.addr =
ccf45caf MS	430	__rewind_psw(regs->psw,
aa33c8cb	431	regs->int_code >> 16);
20b40a79 MS	432	break;
20b40a79 MS	433	}
20b40a79	434	}
d9ae6772 MS	435	/* No longer in a system call */
d9ae6772 MS	436	clear_thread_flag(TIF_SYSCALL);
20b40a79	437
a610d6e6 AV	438	if (is_compat_task())
	439	handle_signal32(signr, &ka, &info, oldset, regs);
	440	else
	441	handle_signal(signr, &ka, &info, oldset, regs);
54dfe5dd HC	442	return;
	443	}
	444
20b40a79	445	/* No handlers present - check for system call restart */
d9ae6772	446	clear_thread_flag(TIF_SYSCALL);
b6ef5bb3	447	if (current_thread_info()->system_call) {
aa33c8cb	448	regs->int_code = current_thread_info()->system_call;
20b40a79 MS	449	switch (regs->gprs[2]) {
	450	case -ERESTART_RESTARTBLOCK:
	451	/* Restart with sys_restart_syscall */
aa33c8cb	452	regs->int_code = __NR_restart_syscall;
20b40a79 MS	453	/* fallthrough */
	454	case -ERESTARTNOHAND:
	455	case -ERESTARTSYS:
	456	case -ERESTARTNOINTR:
	457	/* Restart system call with magic TIF bit. */
	458	regs->gprs[2] = regs->orig_gpr2;
b6ef5bb3 MS	459	set_thread_flag(TIF_SYSCALL);
b6ef5bb3 MS	460	break;
20b40a79 MS	461	}
	462	}
	463
54dfe5dd HC	464	/*
	465	* If there's no signal to deliver, we just put the saved sigmask back.
	466	*/
51a7b448	467	restore_saved_sigmask();
1da177e4	468	}
753c4dd6 MS	469
	470	void do_notify_resume(struct pt_regs *regs)
	471	{
	472	clear_thread_flag(TIF_NOTIFY_RESUME);
	473	tracehook_notify_resume(regs);
	474	}