arch/s390/kernel/compat_signal.c - arm/linux-arm64-legacy - Git at Google

 /*
  *    Copyright IBM Corp. 2000, 2006
  *    Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
  *               Gerhard Tonn (ton@de.ibm.com)
  *
  *  Copyright (C) 1991, 1992  Linus Torvalds
  *
  *  1997-11-28  Modified for POSIX.1b signals by Richard Henderson
  */

 #include <linux/compat.h>
 #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 <asm/ucontext.h>
 #include <asm/uaccess.h>
 #include <asm/lowcore.h>
 #include <asm/switch_to.h>
 #include "compat_linux.h"
 #include "compat_ptrace.h"
 #include "entry.h"

 typedef struct
 {
 	__u8 callee_used_stack[__SIGNAL_FRAMESIZE32];
 	struct sigcontext32 sc;
 	_sigregs32 sregs;
 	int signo;
 	__u32 gprs_high[NUM_GPRS];
 	__u8 retcode[S390_SYSCALL_SIZE];
 } sigframe32;

 typedef struct
 {
 	__u8 callee_used_stack[__SIGNAL_FRAMESIZE32];
 	__u8 retcode[S390_SYSCALL_SIZE];
 	compat_siginfo_t info;
 	struct ucontext32 uc;
 	__u32 gprs_high[NUM_GPRS];
 } rt_sigframe32;

 int copy_siginfo_to_user32(compat_siginfo_t __user *to, const siginfo_t *from)
 {
 	int err;

 	/* If you change siginfo_t structure, please be sure
 	   this code is fixed accordingly.
 	   It should never copy any pad contained in the structure
 	   to avoid security leaks, but must copy the generic
 	   3 ints plus the relevant union member.
 	   This routine must convert siginfo from 64bit to 32bit as well
 	   at the same time.  */
 	err = __put_user(from->si_signo, &to->si_signo);
 	err |= __put_user(from->si_errno, &to->si_errno);
 	err |= __put_user((short)from->si_code, &to->si_code);
 	if (from->si_code < 0)
 		err |= __copy_to_user(&to->_sifields._pad, &from->_sifields._pad, SI_PAD_SIZE);
 	else {
 		switch (from->si_code >> 16) {
 		case __SI_RT >> 16: /* This is not generated by the kernel as of now.  */
 		case __SI_MESGQ >> 16:
 			err |= __put_user(from->si_int, &to->si_int);
 			/* fallthrough */
 		case __SI_KILL >> 16:
 			err |= __put_user(from->si_pid, &to->si_pid);
 			err |= __put_user(from->si_uid, &to->si_uid);
 			break;
 		case __SI_CHLD >> 16:
 			err |= __put_user(from->si_pid, &to->si_pid);
 			err |= __put_user(from->si_uid, &to->si_uid);
 			err |= __put_user(from->si_utime, &to->si_utime);
 			err |= __put_user(from->si_stime, &to->si_stime);
 			err |= __put_user(from->si_status, &to->si_status);
 			break;
 		case __SI_FAULT >> 16:
 			err |= __put_user((unsigned long) from->si_addr,
 					  &to->si_addr);
 			break;
 		case __SI_POLL >> 16:
 			err |= __put_user(from->si_band, &to->si_band);
 			err |= __put_user(from->si_fd, &to->si_fd);
 			break;
 		case __SI_TIMER >> 16:
 			err |= __put_user(from->si_tid, &to->si_tid);
 			err |= __put_user(from->si_overrun, &to->si_overrun);
 			err |= __put_user(from->si_int, &to->si_int);
 			break;
 		default:
 			break;
 		}
 	}
 	return err ? -EFAULT : 0;
 }

 int copy_siginfo_from_user32(siginfo_t *to, compat_siginfo_t __user *from)
 {
 	int err;
 	u32 tmp;

 	err = __get_user(to->si_signo, &from->si_signo);
 	err |= __get_user(to->si_errno, &from->si_errno);
 	err |= __get_user(to->si_code, &from->si_code);

 	if (to->si_code < 0)
 		err |= __copy_from_user(&to->_sifields._pad, &from->_sifields._pad, SI_PAD_SIZE);
 	else {
 		switch (to->si_code >> 16) {
 		case __SI_RT >> 16: /* This is not generated by the kernel as of now.  */
 		case __SI_MESGQ >> 16:
 			err |= __get_user(to->si_int, &from->si_int);
 			/* fallthrough */
 		case __SI_KILL >> 16:
 			err |= __get_user(to->si_pid, &from->si_pid);
 			err |= __get_user(to->si_uid, &from->si_uid);
 			break;
 		case __SI_CHLD >> 16:
 			err |= __get_user(to->si_pid, &from->si_pid);
 			err |= __get_user(to->si_uid, &from->si_uid);
 			err |= __get_user(to->si_utime, &from->si_utime);
 			err |= __get_user(to->si_stime, &from->si_stime);
 			err |= __get_user(to->si_status, &from->si_status);
 			break;
 		case __SI_FAULT >> 16:
 			err |= __get_user(tmp, &from->si_addr);
 			to->si_addr = (void __force __user *)
 				(u64) (tmp & PSW32_ADDR_INSN);
 			break;
 		case __SI_POLL >> 16:
 			err |= __get_user(to->si_band, &from->si_band);
 			err |= __get_user(to->si_fd, &from->si_fd);
 			break;
 		case __SI_TIMER >> 16:
 			err |= __get_user(to->si_tid, &from->si_tid);
 			err |= __get_user(to->si_overrun, &from->si_overrun);
 			err |= __get_user(to->si_int, &from->si_int);
 			break;
 		default:
 			break;
 		}
 	}
 	return err ? -EFAULT : 0;
 }

 static int save_sigregs32(struct pt_regs *regs, _sigregs32 __user *sregs)
 {
 	_sigregs32 user_sregs;
 	int i;

 	user_sregs.regs.psw.mask = (__u32)(regs->psw.mask >> 32);
 	user_sregs.regs.psw.mask &= PSW32_MASK_USER | PSW32_MASK_RI;
 	user_sregs.regs.psw.mask |= PSW32_USER_BITS;
 	user_sregs.regs.psw.addr = (__u32) regs->psw.addr |
 		(__u32)(regs->psw.mask & PSW_MASK_BA);
 	for (i = 0; i < NUM_GPRS; i++)
 		user_sregs.regs.gprs[i] = (__u32) regs->gprs[i];
 	save_access_regs(current->thread.acrs);
 	memcpy(&user_sregs.regs.acrs, current->thread.acrs,
 	       sizeof(user_sregs.regs.acrs));
 	save_fp_ctl(&current->thread.fp_regs.fpc);
 	save_fp_regs(current->thread.fp_regs.fprs);
 	memcpy(&user_sregs.fpregs, &current->thread.fp_regs,
 	       sizeof(user_sregs.fpregs));
 	if (__copy_to_user(sregs, &user_sregs, sizeof(_sigregs32)))
 		return -EFAULT;
 	return 0;
 }

 static int restore_sigregs32(struct pt_regs *regs,_sigregs32 __user *sregs)
 {
 	_sigregs32 user_sregs;
 	int i;

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

 	if (__copy_from_user(&user_sregs, &sregs->regs, sizeof(user_sregs)))
 		return -EFAULT;

 	if (!is_ri_task(current) && (user_sregs.regs.psw.mask & PSW32_MASK_RI))
 		return -EINVAL;

 	/* Loading the floating-point-control word can fail. Do that first. */
 	if (restore_fp_ctl(&user_sregs.fpregs.fpc))
 		return -EINVAL;

 	/* Use regs->psw.mask instead of PSW_USER_BITS to preserve PER bit. */
 	regs->psw.mask = (regs->psw.mask & ~(PSW_MASK_USER | PSW_MASK_RI)) |
 		(__u64)(user_sregs.regs.psw.mask & PSW32_MASK_USER) << 32 |
 		(__u64)(user_sregs.regs.psw.mask & PSW32_MASK_RI) << 32 |
 		(__u64)(user_sregs.regs.psw.addr & PSW32_ADDR_AMODE);
 	/* Check for invalid user address space control. */
 	if ((regs->psw.mask & PSW_MASK_ASC) == PSW_ASC_HOME)
 		regs->psw.mask = PSW_ASC_PRIMARY |
 			(regs->psw.mask & ~PSW_MASK_ASC);
 	regs->psw.addr = (__u64)(user_sregs.regs.psw.addr & PSW32_ADDR_INSN);
 	for (i = 0; i < NUM_GPRS; i++)
 		regs->gprs[i] = (__u64) user_sregs.regs.gprs[i];
 	memcpy(&current->thread.acrs, &user_sregs.regs.acrs,
 	       sizeof(current->thread.acrs));
 	restore_access_regs(current->thread.acrs);

 	memcpy(&current->thread.fp_regs, &user_sregs.fpregs,
 	       sizeof(current->thread.fp_regs));

 	restore_fp_regs(current->thread.fp_regs.fprs);
 	clear_pt_regs_flag(regs, PIF_SYSCALL); /* No longer in a system call */
 	return 0;
 }

 static int save_sigregs_gprs_high(struct pt_regs *regs, __u32 __user *uregs)
 {
 	__u32 gprs_high[NUM_GPRS];
 	int i;

 	for (i = 0; i < NUM_GPRS; i++)
 		gprs_high[i] = regs->gprs[i] >> 32;
 	if (__copy_to_user(uregs, &gprs_high, sizeof(gprs_high)))
 		return -EFAULT;
 	return 0;
 }

 static int restore_sigregs_gprs_high(struct pt_regs *regs, __u32 __user *uregs)
 {
 	__u32 gprs_high[NUM_GPRS];
 	int i;

 	if (__copy_from_user(&gprs_high, uregs, sizeof(gprs_high)))
 		return -EFAULT;
 	for (i = 0; i < NUM_GPRS; i++)
 		*(__u32 *)&regs->gprs[i] = gprs_high[i];
 	return 0;
 }

 COMPAT_SYSCALL_DEFINE0(sigreturn)
 {
 	struct pt_regs *regs = task_pt_regs(current);
 	sigframe32 __user *frame = (sigframe32 __user *)regs->gprs[15];
 	sigset_t set;

 	if (__copy_from_user(&set.sig, &frame->sc.oldmask, _SIGMASK_COPY_SIZE32))
 		goto badframe;
 	set_current_blocked(&set);
 	if (restore_sigregs32(regs, &frame->sregs))
 		goto badframe;
 	if (restore_sigregs_gprs_high(regs, frame->gprs_high))
 		goto badframe;
 	return regs->gprs[2];
 badframe:
 	force_sig(SIGSEGV, current);
 	return 0;
 }

 COMPAT_SYSCALL_DEFINE0(rt_sigreturn)
 {
 	struct pt_regs *regs = task_pt_regs(current);
 	rt_sigframe32 __user *frame = (rt_sigframe32 __user *)regs->gprs[15];
 	sigset_t set;

 	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
 		goto badframe;
 	set_current_blocked(&set);
 	if (restore_sigregs32(regs, &frame->uc.uc_mcontext))
 		goto badframe;
 	if (restore_sigregs_gprs_high(regs, frame->gprs_high))
 		goto badframe;
 	if (compat_restore_altstack(&frame->uc.uc_stack))
 		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 = (unsigned long) A(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_frame32(int sig, struct k_sigaction *ka,
 			sigset_t *set, struct pt_regs * regs)
 {
 	sigframe32 __user *frame = get_sigframe(ka, regs, sizeof(sigframe32));

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

 	if (__copy_to_user(&frame->sc.oldmask, &set->sig, _SIGMASK_COPY_SIZE32))
 		goto give_sigsegv;

 	if (save_sigregs32(regs, &frame->sregs))
 		goto give_sigsegv;
 	if (save_sigregs_gprs_high(regs, frame->gprs_high))
 		goto give_sigsegv;
 	if (__put_user((unsigned long) &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] = (__u64 __force) ka->sa.sa_restorer | PSW32_ADDR_AMODE;
 	} else {
 		regs->gprs[14] = (__u64 __force) frame->retcode | PSW32_ADDR_AMODE;
 		if (__put_user(S390_SYSCALL_OPCODE | __NR_sigreturn,
 			       (u16 __force __user *)(frame->retcode)))
 			goto give_sigsegv;
         }

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

 	/* Set up registers for signal handler */
 	regs->gprs[15] = (__force __u64) frame;
 	/* Force 31 bit amode and default user address space control. */
 	regs->psw.mask = PSW_MASK_BA |
 		(PSW_USER_BITS & PSW_MASK_ASC) |
 		(regs->psw.mask & ~PSW_MASK_ASC);
 	regs->psw.addr = (__force __u64) ka->sa.sa_handler;

 	regs->gprs[2] = map_signal(sig);
 	regs->gprs[3] = (__force __u64) &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 __force __user *) &frame->signo))
 		goto give_sigsegv;
 	return 0;

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

 static int setup_rt_frame32(int sig, struct k_sigaction *ka, siginfo_t *info,
 			   sigset_t *set, struct pt_regs * regs)
 {
 	int err = 0;
 	rt_sigframe32 __user *frame = get_sigframe(ka, regs, sizeof(rt_sigframe32));

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

 	if (copy_siginfo_to_user32(&frame->info, info))
 		goto give_sigsegv;

 	/* Create the ucontext.  */
 	err |= __put_user(UC_EXTENDED, &frame->uc.uc_flags);
 	err |= __put_user(0, &frame->uc.uc_link);
 	err |= __compat_save_altstack(&frame->uc.uc_stack, regs->gprs[15]);
 	err |= save_sigregs32(regs, &frame->uc.uc_mcontext);
 	err |= save_sigregs_gprs_high(regs, frame->gprs_high);
 	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] = (__u64 __force) ka->sa.sa_restorer | PSW32_ADDR_AMODE;
 	} else {
 		regs->gprs[14] = (__u64 __force) frame->retcode | PSW32_ADDR_AMODE;
 		if (__put_user(S390_SYSCALL_OPCODE | __NR_rt_sigreturn,
 			       (u16 __force __user *)(frame->retcode)))
 			goto give_sigsegv;
 	}

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

 	/* Set up registers for signal handler */
 	regs->gprs[15] = (__force __u64) frame;
 	/* Force 31 bit amode and default user address space control. */
 	regs->psw.mask = PSW_MASK_BA |
 		(PSW_USER_BITS & PSW_MASK_ASC) |
 		(regs->psw.mask & ~PSW_MASK_ASC);
 	regs->psw.addr = (__u64 __force) ka->sa.sa_handler;

 	regs->gprs[2] = map_signal(sig);
 	regs->gprs[3] = (__force __u64) &frame->info;
 	regs->gprs[4] = (__force __u64) &frame->uc;
 	regs->gprs[5] = task_thread_info(current)->last_break;
 	return 0;

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

 /*
  * OK, we're invoking a handler
  */

 void handle_signal32(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_frame32(sig, ka, info, oldset, regs);
 	else
 		ret = setup_frame32(sig, ka, oldset, regs);
 	if (ret)
 		return;
 	signal_delivered(sig, info, ka, regs,
 				 test_thread_flag(TIF_SINGLE_STEP));
 }
	/*
	* Copyright IBM Corp. 2000, 2006
	* Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
	* Gerhard Tonn (ton@de.ibm.com)
	*
	* Copyright (C) 1991, 1992 Linus Torvalds
	*
	* 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
	*/

	#include <linux/compat.h>
	#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 <asm/ucontext.h>
	#include <asm/uaccess.h>
	#include <asm/lowcore.h>
	#include <asm/switch_to.h>
	#include "compat_linux.h"
	#include "compat_ptrace.h"
	#include "entry.h"

	typedef struct
	{
	__u8 callee_used_stack[__SIGNAL_FRAMESIZE32];
	struct sigcontext32 sc;
	_sigregs32 sregs;
	int signo;
	__u32 gprs_high[NUM_GPRS];
	__u8 retcode[S390_SYSCALL_SIZE];
	} sigframe32;

	typedef struct
	{
	__u8 callee_used_stack[__SIGNAL_FRAMESIZE32];
	__u8 retcode[S390_SYSCALL_SIZE];
	compat_siginfo_t info;
	struct ucontext32 uc;
	__u32 gprs_high[NUM_GPRS];
	} rt_sigframe32;

	int copy_siginfo_to_user32(compat_siginfo_t __user to, const siginfo_t from)
	{
	int err;

	/* If you change siginfo_t structure, please be sure
	this code is fixed accordingly.
	It should never copy any pad contained in the structure
	to avoid security leaks, but must copy the generic
	3 ints plus the relevant union member.
	This routine must convert siginfo from 64bit to 32bit as well
	at the same time. */
	err = __put_user(from->si_signo, &to->si_signo);
	err \|= __put_user(from->si_errno, &to->si_errno);
	err \|= __put_user((short)from->si_code, &to->si_code);
	if (from->si_code < 0)
	err \|= __copy_to_user(&to->_sifields._pad, &from->_sifields._pad, SI_PAD_SIZE);
	else {
	switch (from->si_code >> 16) {
	case __SI_RT >> 16: /* This is not generated by the kernel as of now. */
	case __SI_MESGQ >> 16:
	err \|= __put_user(from->si_int, &to->si_int);
	/* fallthrough */
	case __SI_KILL >> 16:
	err \|= __put_user(from->si_pid, &to->si_pid);
	err \|= __put_user(from->si_uid, &to->si_uid);
	break;
	case __SI_CHLD >> 16:
	err \|= __put_user(from->si_pid, &to->si_pid);
	err \|= __put_user(from->si_uid, &to->si_uid);
	err \|= __put_user(from->si_utime, &to->si_utime);
	err \|= __put_user(from->si_stime, &to->si_stime);
	err \|= __put_user(from->si_status, &to->si_status);
	break;
	case __SI_FAULT >> 16:
	err \|= __put_user((unsigned long) from->si_addr,
	&to->si_addr);
	break;
	case __SI_POLL >> 16:
	err \|= __put_user(from->si_band, &to->si_band);
	err \|= __put_user(from->si_fd, &to->si_fd);
	break;
	case __SI_TIMER >> 16:
	err \|= __put_user(from->si_tid, &to->si_tid);
	err \|= __put_user(from->si_overrun, &to->si_overrun);
	err \|= __put_user(from->si_int, &to->si_int);
	break;
	default:
	break;
	}
	}
	return err ? -EFAULT : 0;
	}

	int copy_siginfo_from_user32(siginfo_t to, compat_siginfo_t __user from)
	{
	int err;
	u32 tmp;

	err = __get_user(to->si_signo, &from->si_signo);
	err \|= __get_user(to->si_errno, &from->si_errno);
	err \|= __get_user(to->si_code, &from->si_code);

	if (to->si_code < 0)
	err \|= __copy_from_user(&to->_sifields._pad, &from->_sifields._pad, SI_PAD_SIZE);
	else {
	switch (to->si_code >> 16) {
	case __SI_RT >> 16: /* This is not generated by the kernel as of now. */
	case __SI_MESGQ >> 16:
	err \|= __get_user(to->si_int, &from->si_int);
	/* fallthrough */
	case __SI_KILL >> 16:
	err \|= __get_user(to->si_pid, &from->si_pid);
	err \|= __get_user(to->si_uid, &from->si_uid);
	break;
	case __SI_CHLD >> 16:
	err \|= __get_user(to->si_pid, &from->si_pid);
	err \|= __get_user(to->si_uid, &from->si_uid);
	err \|= __get_user(to->si_utime, &from->si_utime);
	err \|= __get_user(to->si_stime, &from->si_stime);
	err \|= __get_user(to->si_status, &from->si_status);
	break;
	case __SI_FAULT >> 16:
	err \|= __get_user(tmp, &from->si_addr);
	to->si_addr = (void __force __user *)
	(u64) (tmp & PSW32_ADDR_INSN);
	break;
	case __SI_POLL >> 16:
	err \|= __get_user(to->si_band, &from->si_band);
	err \|= __get_user(to->si_fd, &from->si_fd);
	break;
	case __SI_TIMER >> 16:
	err \|= __get_user(to->si_tid, &from->si_tid);
	err \|= __get_user(to->si_overrun, &from->si_overrun);
	err \|= __get_user(to->si_int, &from->si_int);
	break;
	default:
	break;
	}
	}
	return err ? -EFAULT : 0;
	}

	static int save_sigregs32(struct pt_regs regs, _sigregs32 __user sregs)
	{
	_sigregs32 user_sregs;
	int i;

	user_sregs.regs.psw.mask = (__u32)(regs->psw.mask >> 32);
	user_sregs.regs.psw.mask &= PSW32_MASK_USER \| PSW32_MASK_RI;
	user_sregs.regs.psw.mask \|= PSW32_USER_BITS;
	user_sregs.regs.psw.addr = (__u32) regs->psw.addr \|
	(__u32)(regs->psw.mask & PSW_MASK_BA);
	for (i = 0; i < NUM_GPRS; i++)
	user_sregs.regs.gprs[i] = (__u32) regs->gprs[i];
	save_access_regs(current->thread.acrs);
	memcpy(&user_sregs.regs.acrs, current->thread.acrs,
	sizeof(user_sregs.regs.acrs));
	save_fp_ctl(&current->thread.fp_regs.fpc);
	save_fp_regs(current->thread.fp_regs.fprs);
	memcpy(&user_sregs.fpregs, &current->thread.fp_regs,
	sizeof(user_sregs.fpregs));
	if (__copy_to_user(sregs, &user_sregs, sizeof(_sigregs32)))
	return -EFAULT;
	return 0;
	}

	static int restore_sigregs32(struct pt_regs regs,_sigregs32 __user sregs)
	{
	_sigregs32 user_sregs;
	int i;

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

	if (__copy_from_user(&user_sregs, &sregs->regs, sizeof(user_sregs)))
	return -EFAULT;

	if (!is_ri_task(current) && (user_sregs.regs.psw.mask & PSW32_MASK_RI))
	return -EINVAL;

	/* Loading the floating-point-control word can fail. Do that first. */
	if (restore_fp_ctl(&user_sregs.fpregs.fpc))
	return -EINVAL;

	/* Use regs->psw.mask instead of PSW_USER_BITS to preserve PER bit. */
	regs->psw.mask = (regs->psw.mask & ~(PSW_MASK_USER \| PSW_MASK_RI)) \|
	(__u64)(user_sregs.regs.psw.mask & PSW32_MASK_USER) << 32 \|
	(__u64)(user_sregs.regs.psw.mask & PSW32_MASK_RI) << 32 \|
	(__u64)(user_sregs.regs.psw.addr & PSW32_ADDR_AMODE);
	/* Check for invalid user address space control. */
	if ((regs->psw.mask & PSW_MASK_ASC) == PSW_ASC_HOME)
	regs->psw.mask = PSW_ASC_PRIMARY \|
	(regs->psw.mask & ~PSW_MASK_ASC);
	regs->psw.addr = (__u64)(user_sregs.regs.psw.addr & PSW32_ADDR_INSN);
	for (i = 0; i < NUM_GPRS; i++)
	regs->gprs[i] = (__u64) user_sregs.regs.gprs[i];
	memcpy(&current->thread.acrs, &user_sregs.regs.acrs,
	sizeof(current->thread.acrs));
	restore_access_regs(current->thread.acrs);

	memcpy(&current->thread.fp_regs, &user_sregs.fpregs,
	sizeof(current->thread.fp_regs));

	restore_fp_regs(current->thread.fp_regs.fprs);
	clear_pt_regs_flag(regs, PIF_SYSCALL); /* No longer in a system call */
	return 0;
	}

	static int save_sigregs_gprs_high(struct pt_regs regs, __u32 __user uregs)
	{
	__u32 gprs_high[NUM_GPRS];
	int i;

	for (i = 0; i < NUM_GPRS; i++)
	gprs_high[i] = regs->gprs[i] >> 32;
	if (__copy_to_user(uregs, &gprs_high, sizeof(gprs_high)))
	return -EFAULT;
	return 0;
	}

	static int restore_sigregs_gprs_high(struct pt_regs regs, __u32 __user uregs)
	{
	__u32 gprs_high[NUM_GPRS];
	int i;

	if (__copy_from_user(&gprs_high, uregs, sizeof(gprs_high)))
	return -EFAULT;
	for (i = 0; i < NUM_GPRS; i++)
	(__u32 )&regs->gprs[i] = gprs_high[i];
	return 0;
	}

	COMPAT_SYSCALL_DEFINE0(sigreturn)
	{
	struct pt_regs *regs = task_pt_regs(current);
	sigframe32 __user frame = (sigframe32 __user )regs->gprs[15];
	sigset_t set;

	if (__copy_from_user(&set.sig, &frame->sc.oldmask, _SIGMASK_COPY_SIZE32))
	goto badframe;
	set_current_blocked(&set);
	if (restore_sigregs32(regs, &frame->sregs))
	goto badframe;
	if (restore_sigregs_gprs_high(regs, frame->gprs_high))
	goto badframe;
	return regs->gprs[2];
	badframe:
	force_sig(SIGSEGV, current);
	return 0;
	}

	COMPAT_SYSCALL_DEFINE0(rt_sigreturn)
	{
	struct pt_regs *regs = task_pt_regs(current);
	rt_sigframe32 __user frame = (rt_sigframe32 __user )regs->gprs[15];
	sigset_t set;

	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
	goto badframe;
	set_current_blocked(&set);
	if (restore_sigregs32(regs, &frame->uc.uc_mcontext))
	goto badframe;
	if (restore_sigregs_gprs_high(regs, frame->gprs_high))
	goto badframe;
	if (compat_restore_altstack(&frame->uc.uc_stack))
	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 = (unsigned long) A(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_frame32(int sig, struct k_sigaction *ka,
	sigset_t set, struct pt_regs regs)
	{
	sigframe32 __user *frame = get_sigframe(ka, regs, sizeof(sigframe32));

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

	if (__copy_to_user(&frame->sc.oldmask, &set->sig, _SIGMASK_COPY_SIZE32))
	goto give_sigsegv;

	if (save_sigregs32(regs, &frame->sregs))
	goto give_sigsegv;
	if (save_sigregs_gprs_high(regs, frame->gprs_high))
	goto give_sigsegv;
	if (__put_user((unsigned long) &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] = (__u64 __force) ka->sa.sa_restorer \| PSW32_ADDR_AMODE;
	} else {
	regs->gprs[14] = (__u64 __force) frame->retcode \| PSW32_ADDR_AMODE;
	if (__put_user(S390_SYSCALL_OPCODE \| __NR_sigreturn,
	(u16 __force __user *)(frame->retcode)))
	goto give_sigsegv;
	}

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

	/* Set up registers for signal handler */
	regs->gprs[15] = (__force __u64) frame;
	/* Force 31 bit amode and default user address space control. */
	regs->psw.mask = PSW_MASK_BA \|
	(PSW_USER_BITS & PSW_MASK_ASC) \|
	(regs->psw.mask & ~PSW_MASK_ASC);
	regs->psw.addr = (__force __u64) ka->sa.sa_handler;

	regs->gprs[2] = map_signal(sig);
	regs->gprs[3] = (__force __u64) &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 __force __user *) &frame->signo))
	goto give_sigsegv;
	return 0;

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

	static int setup_rt_frame32(int sig, struct k_sigaction ka, siginfo_t info,
	sigset_t set, struct pt_regs regs)
	{
	int err = 0;
	rt_sigframe32 __user *frame = get_sigframe(ka, regs, sizeof(rt_sigframe32));

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

	if (copy_siginfo_to_user32(&frame->info, info))
	goto give_sigsegv;

	/* Create the ucontext. */
	err \|= __put_user(UC_EXTENDED, &frame->uc.uc_flags);
	err \|= __put_user(0, &frame->uc.uc_link);
	err \|= __compat_save_altstack(&frame->uc.uc_stack, regs->gprs[15]);
	err \|= save_sigregs32(regs, &frame->uc.uc_mcontext);
	err \|= save_sigregs_gprs_high(regs, frame->gprs_high);
	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] = (__u64 __force) ka->sa.sa_restorer \| PSW32_ADDR_AMODE;
	} else {
	regs->gprs[14] = (__u64 __force) frame->retcode \| PSW32_ADDR_AMODE;
	if (__put_user(S390_SYSCALL_OPCODE \| __NR_rt_sigreturn,
	(u16 __force __user *)(frame->retcode)))
	goto give_sigsegv;
	}

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

	/* Set up registers for signal handler */
	regs->gprs[15] = (__force __u64) frame;
	/* Force 31 bit amode and default user address space control. */
	regs->psw.mask = PSW_MASK_BA \|
	(PSW_USER_BITS & PSW_MASK_ASC) \|
	(regs->psw.mask & ~PSW_MASK_ASC);
	regs->psw.addr = (__u64 __force) ka->sa.sa_handler;

	regs->gprs[2] = map_signal(sig);
	regs->gprs[3] = (__force __u64) &frame->info;
	regs->gprs[4] = (__force __u64) &frame->uc;
	regs->gprs[5] = task_thread_info(current)->last_break;
	return 0;

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

	/*
	* OK, we're invoking a handler
	*/

	void handle_signal32(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_frame32(sig, ka, info, oldset, regs);
	else
	ret = setup_frame32(sig, ka, oldset, regs);
	if (ret)
	return;
	signal_delivered(sig, info, ka, regs,
	test_thread_flag(TIF_SINGLE_STEP));
	}