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v6.2
  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 *    Copyright IBM Corp. 2000, 2006
  4 *    Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
  5 *               Gerhard Tonn (ton@de.ibm.com)                  
  6 *
  7 *  Copyright (C) 1991, 1992  Linus Torvalds
  8 *
  9 *  1997-11-28  Modified for POSIX.1b signals by Richard Henderson
 10 */
 11
 12#include <linux/compat.h>
 13#include <linux/sched.h>
 14#include <linux/sched/task_stack.h>
 15#include <linux/mm.h>
 16#include <linux/smp.h>
 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>
 27#include <asm/ucontext.h>
 28#include <linux/uaccess.h>
 29#include <asm/lowcore.h>
 30#include <asm/switch_to.h>
 31#include <asm/vdso.h>
 32#include "compat_linux.h"
 33#include "compat_ptrace.h"
 34#include "entry.h"
 35
 36typedef struct 
 37{
 38	__u8 callee_used_stack[__SIGNAL_FRAMESIZE32];
 39	struct sigcontext32 sc;
 40	_sigregs32 sregs;
 41	int signo;
 42	_sigregs_ext32 sregs_ext;
 43	__u16 svc_insn;		/* Offset of svc_insn is NOT fixed! */
 44} sigframe32;
 45
 46typedef struct 
 47{
 48	__u8 callee_used_stack[__SIGNAL_FRAMESIZE32];
 49	__u16 svc_insn;
 50	compat_siginfo_t info;
 51	struct ucontext32 uc;
 52} rt_sigframe32;
 53
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 54/* Store registers needed to create the signal frame */
 55static void store_sigregs(void)
 56{
 57	save_access_regs(current->thread.acrs);
 58	save_fpu_regs();
 59}
 60
 61/* Load registers after signal return */
 62static void load_sigregs(void)
 63{
 64	restore_access_regs(current->thread.acrs);
 65}
 66
 67static int save_sigregs32(struct pt_regs *regs, _sigregs32 __user *sregs)
 68{
 69	_sigregs32 user_sregs;
 70	int i;
 71
 72	user_sregs.regs.psw.mask = (__u32)(regs->psw.mask >> 32);
 73	user_sregs.regs.psw.mask &= PSW32_MASK_USER | PSW32_MASK_RI;
 74	user_sregs.regs.psw.mask |= PSW32_USER_BITS;
 75	user_sregs.regs.psw.addr = (__u32) regs->psw.addr |
 76		(__u32)(regs->psw.mask & PSW_MASK_BA);
 77	for (i = 0; i < NUM_GPRS; i++)
 78		user_sregs.regs.gprs[i] = (__u32) regs->gprs[i];
 79	memcpy(&user_sregs.regs.acrs, current->thread.acrs,
 80	       sizeof(user_sregs.regs.acrs));
 81	fpregs_store((_s390_fp_regs *) &user_sregs.fpregs, &current->thread.fpu);
 82	if (__copy_to_user(sregs, &user_sregs, sizeof(_sigregs32)))
 83		return -EFAULT;
 84	return 0;
 85}
 86
 87static int restore_sigregs32(struct pt_regs *regs,_sigregs32 __user *sregs)
 88{
 89	_sigregs32 user_sregs;
 90	int i;
 91
 92	/* Always make any pending restarted system call return -EINTR */
 93	current->restart_block.fn = do_no_restart_syscall;
 94
 95	if (__copy_from_user(&user_sregs, &sregs->regs, sizeof(user_sregs)))
 96		return -EFAULT;
 97
 98	if (!is_ri_task(current) && (user_sregs.regs.psw.mask & PSW32_MASK_RI))
 99		return -EINVAL;
100
101	/* Test the floating-point-control word. */
102	if (test_fp_ctl(user_sregs.fpregs.fpc))
103		return -EINVAL;
104
105	/* Use regs->psw.mask instead of PSW_USER_BITS to preserve PER bit. */
106	regs->psw.mask = (regs->psw.mask & ~(PSW_MASK_USER | PSW_MASK_RI)) |
107		(__u64)(user_sregs.regs.psw.mask & PSW32_MASK_USER) << 32 |
108		(__u64)(user_sregs.regs.psw.mask & PSW32_MASK_RI) << 32 |
109		(__u64)(user_sregs.regs.psw.addr & PSW32_ADDR_AMODE);
110	/* Check for invalid user address space control. */
111	if ((regs->psw.mask & PSW_MASK_ASC) == PSW_ASC_HOME)
112		regs->psw.mask = PSW_ASC_PRIMARY |
113			(regs->psw.mask & ~PSW_MASK_ASC);
114	regs->psw.addr = (__u64)(user_sregs.regs.psw.addr & PSW32_ADDR_INSN);
115	for (i = 0; i < NUM_GPRS; i++)
116		regs->gprs[i] = (__u64) user_sregs.regs.gprs[i];
117	memcpy(&current->thread.acrs, &user_sregs.regs.acrs,
118	       sizeof(current->thread.acrs));
119	fpregs_load((_s390_fp_regs *) &user_sregs.fpregs, &current->thread.fpu);
120
121	clear_pt_regs_flag(regs, PIF_SYSCALL); /* No longer in a system call */
122	return 0;
123}
124
125static int save_sigregs_ext32(struct pt_regs *regs,
126			      _sigregs_ext32 __user *sregs_ext)
127{
128	__u32 gprs_high[NUM_GPRS];
129	__u64 vxrs[__NUM_VXRS_LOW];
130	int i;
131
132	/* Save high gprs to signal stack */
133	for (i = 0; i < NUM_GPRS; i++)
134		gprs_high[i] = regs->gprs[i] >> 32;
135	if (__copy_to_user(&sregs_ext->gprs_high, &gprs_high,
136			   sizeof(sregs_ext->gprs_high)))
137		return -EFAULT;
138
139	/* Save vector registers to signal stack */
140	if (MACHINE_HAS_VX) {
141		for (i = 0; i < __NUM_VXRS_LOW; i++)
142			vxrs[i] = *((__u64 *)(current->thread.fpu.vxrs + i) + 1);
143		if (__copy_to_user(&sregs_ext->vxrs_low, vxrs,
144				   sizeof(sregs_ext->vxrs_low)) ||
145		    __copy_to_user(&sregs_ext->vxrs_high,
146				   current->thread.fpu.vxrs + __NUM_VXRS_LOW,
147				   sizeof(sregs_ext->vxrs_high)))
148			return -EFAULT;
149	}
150	return 0;
151}
152
153static int restore_sigregs_ext32(struct pt_regs *regs,
154				 _sigregs_ext32 __user *sregs_ext)
155{
156	__u32 gprs_high[NUM_GPRS];
157	__u64 vxrs[__NUM_VXRS_LOW];
158	int i;
159
160	/* Restore high gprs from signal stack */
161	if (__copy_from_user(&gprs_high, &sregs_ext->gprs_high,
162			     sizeof(sregs_ext->gprs_high)))
163		return -EFAULT;
164	for (i = 0; i < NUM_GPRS; i++)
165		*(__u32 *)&regs->gprs[i] = gprs_high[i];
166
167	/* Restore vector registers from signal stack */
168	if (MACHINE_HAS_VX) {
169		if (__copy_from_user(vxrs, &sregs_ext->vxrs_low,
170				     sizeof(sregs_ext->vxrs_low)) ||
171		    __copy_from_user(current->thread.fpu.vxrs + __NUM_VXRS_LOW,
172				     &sregs_ext->vxrs_high,
173				     sizeof(sregs_ext->vxrs_high)))
174			return -EFAULT;
175		for (i = 0; i < __NUM_VXRS_LOW; i++)
176			*((__u64 *)(current->thread.fpu.vxrs + i) + 1) = vxrs[i];
177	}
178	return 0;
179}
180
181COMPAT_SYSCALL_DEFINE0(sigreturn)
182{
183	struct pt_regs *regs = task_pt_regs(current);
184	sigframe32 __user *frame = (sigframe32 __user *)regs->gprs[15];
 
185	sigset_t set;
186
187	if (get_compat_sigset(&set, (compat_sigset_t __user *)frame->sc.oldmask))
188		goto badframe;
 
189	set_current_blocked(&set);
190	save_fpu_regs();
191	if (restore_sigregs32(regs, &frame->sregs))
192		goto badframe;
193	if (restore_sigregs_ext32(regs, &frame->sregs_ext))
194		goto badframe;
195	load_sigregs();
196	return regs->gprs[2];
197badframe:
198	force_sig(SIGSEGV);
199	return 0;
200}
201
202COMPAT_SYSCALL_DEFINE0(rt_sigreturn)
203{
204	struct pt_regs *regs = task_pt_regs(current);
205	rt_sigframe32 __user *frame = (rt_sigframe32 __user *)regs->gprs[15];
 
206	sigset_t set;
207
208	if (get_compat_sigset(&set, &frame->uc.uc_sigmask))
209		goto badframe;
 
210	set_current_blocked(&set);
211	if (compat_restore_altstack(&frame->uc.uc_stack))
212		goto badframe;
213	save_fpu_regs();
214	if (restore_sigregs32(regs, &frame->uc.uc_mcontext))
215		goto badframe;
216	if (restore_sigregs_ext32(regs, &frame->uc.uc_mcontext_ext))
217		goto badframe;
218	load_sigregs();
219	return regs->gprs[2];
220badframe:
221	force_sig(SIGSEGV);
222	return 0;
223}	
224
225/*
226 * Set up a signal frame.
227 */
228
229
230/*
231 * Determine which stack to use..
232 */
233static inline void __user *
234get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size)
235{
236	unsigned long sp;
237
238	/* Default to using normal stack */
239	sp = (unsigned long) A(regs->gprs[15]);
240
241	/* Overflow on alternate signal stack gives SIGSEGV. */
242	if (on_sig_stack(sp) && !on_sig_stack((sp - frame_size) & -8UL))
243		return (void __user *) -1UL;
244
245	/* This is the X/Open sanctioned signal stack switching.  */
246	if (ka->sa.sa_flags & SA_ONSTACK) {
247		if (! sas_ss_flags(sp))
248			sp = current->sas_ss_sp + current->sas_ss_size;
249	}
250
251	return (void __user *)((sp - frame_size) & -8ul);
252}
253
254static int setup_frame32(struct ksignal *ksig, sigset_t *set,
255			 struct pt_regs *regs)
256{
257	int sig = ksig->sig;
258	sigframe32 __user *frame;
 
259	unsigned long restorer;
260	size_t frame_size;
261
262	/*
263	 * gprs_high are always present for 31-bit compat tasks.
264	 * The space for vector registers is only allocated if
265	 * the machine supports it
266	 */
267	frame_size = sizeof(*frame) - sizeof(frame->sregs_ext.__reserved);
268	if (!MACHINE_HAS_VX)
269		frame_size -= sizeof(frame->sregs_ext.vxrs_low) +
270			      sizeof(frame->sregs_ext.vxrs_high);
271	frame = get_sigframe(&ksig->ka, regs, frame_size);
272	if (frame == (void __user *) -1UL)
273		return -EFAULT;
274
275	/* Set up backchain. */
276	if (__put_user(regs->gprs[15], (unsigned int __user *) frame))
277		return -EFAULT;
278
279	/* Create struct sigcontext32 on the signal stack */
280	if (put_compat_sigset((compat_sigset_t __user *)frame->sc.oldmask,
281			      set, sizeof(compat_sigset_t)))
282		return -EFAULT;
283	if (__put_user(ptr_to_compat(&frame->sregs), &frame->sc.sregs))
284		return -EFAULT;
285
286	/* Store registers needed to create the signal frame */
287	store_sigregs();
288
289	/* Create _sigregs32 on the signal stack */
290	if (save_sigregs32(regs, &frame->sregs))
291		return -EFAULT;
292
293	/* Place signal number on stack to allow backtrace from handler.  */
294	if (__put_user(regs->gprs[2], (int __force __user *) &frame->signo))
295		return -EFAULT;
296
297	/* Create _sigregs_ext32 on the signal stack */
298	if (save_sigregs_ext32(regs, &frame->sregs_ext))
299		return -EFAULT;
300
301	/* Set up to return from userspace.  If provided, use a stub
302	   already in userspace.  */
303	if (ksig->ka.sa.sa_flags & SA_RESTORER) {
304		restorer = (unsigned long __force)
305			ksig->ka.sa.sa_restorer | PSW32_ADDR_AMODE;
306	} else {
307		restorer = VDSO32_SYMBOL(current, sigreturn);
 
 
 
 
308        }
309
310	/* Set up registers for signal handler */
311	regs->gprs[14] = restorer;
312	regs->gprs[15] = (__force __u64) frame;
313	/* Force 31 bit amode and default user address space control. */
314	regs->psw.mask = PSW_MASK_BA |
315		(PSW_USER_BITS & PSW_MASK_ASC) |
316		(regs->psw.mask & ~PSW_MASK_ASC);
317	regs->psw.addr = (__force __u64) ksig->ka.sa.sa_handler;
318
319	regs->gprs[2] = sig;
320	regs->gprs[3] = (__force __u64) &frame->sc;
321
322	/* We forgot to include these in the sigcontext.
323	   To avoid breaking binary compatibility, they are passed as args. */
324	if (sig == SIGSEGV || sig == SIGBUS || sig == SIGILL ||
325	    sig == SIGTRAP || sig == SIGFPE) {
326		/* set extra registers only for synchronous signals */
327		regs->gprs[4] = regs->int_code & 127;
328		regs->gprs[5] = regs->int_parm_long;
329		regs->gprs[6] = current->thread.last_break;
330	}
331
332	return 0;
333}
334
335static int setup_rt_frame32(struct ksignal *ksig, sigset_t *set,
336			    struct pt_regs *regs)
337{
 
338	rt_sigframe32 __user *frame;
339	unsigned long restorer;
340	size_t frame_size;
341	u32 uc_flags;
342
343	frame_size = sizeof(*frame) -
344		     sizeof(frame->uc.uc_mcontext_ext.__reserved);
345	/*
346	 * gprs_high are always present for 31-bit compat tasks.
347	 * The space for vector registers is only allocated if
348	 * the machine supports it
349	 */
350	uc_flags = UC_GPRS_HIGH;
351	if (MACHINE_HAS_VX) {
352		uc_flags |= UC_VXRS;
353	} else
354		frame_size -= sizeof(frame->uc.uc_mcontext_ext.vxrs_low) +
355			      sizeof(frame->uc.uc_mcontext_ext.vxrs_high);
356	frame = get_sigframe(&ksig->ka, regs, frame_size);
357	if (frame == (void __user *) -1UL)
358		return -EFAULT;
359
360	/* Set up backchain. */
361	if (__put_user(regs->gprs[15], (unsigned int __force __user *) frame))
362		return -EFAULT;
363
364	/* Set up to return from userspace.  If provided, use a stub
365	   already in userspace.  */
366	if (ksig->ka.sa.sa_flags & SA_RESTORER) {
367		restorer = (unsigned long __force)
368			ksig->ka.sa.sa_restorer | PSW32_ADDR_AMODE;
369	} else {
370		restorer = VDSO32_SYMBOL(current, rt_sigreturn);
 
 
 
371	}
372
373	/* Create siginfo on the signal stack */
374	if (copy_siginfo_to_user32(&frame->info, &ksig->info))
375		return -EFAULT;
376
377	/* Store registers needed to create the signal frame */
378	store_sigregs();
379
380	/* Create ucontext on the signal stack. */
 
381	if (__put_user(uc_flags, &frame->uc.uc_flags) ||
382	    __put_user(0, &frame->uc.uc_link) ||
383	    __compat_save_altstack(&frame->uc.uc_stack, regs->gprs[15]) ||
384	    save_sigregs32(regs, &frame->uc.uc_mcontext) ||
385	    put_compat_sigset(&frame->uc.uc_sigmask, set, sizeof(compat_sigset_t)) ||
386	    save_sigregs_ext32(regs, &frame->uc.uc_mcontext_ext))
387		return -EFAULT;
388
389	/* Set up registers for signal handler */
390	regs->gprs[14] = restorer;
391	regs->gprs[15] = (__force __u64) frame;
392	/* Force 31 bit amode and default user address space control. */
393	regs->psw.mask = PSW_MASK_BA |
394		(PSW_USER_BITS & PSW_MASK_ASC) |
395		(regs->psw.mask & ~PSW_MASK_ASC);
396	regs->psw.addr = (__u64 __force) ksig->ka.sa.sa_handler;
397
398	regs->gprs[2] = ksig->sig;
399	regs->gprs[3] = (__force __u64) &frame->info;
400	regs->gprs[4] = (__force __u64) &frame->uc;
401	regs->gprs[5] = current->thread.last_break;
402	return 0;
403}
404
405/*
406 * OK, we're invoking a handler
407 */	
408
409void handle_signal32(struct ksignal *ksig, sigset_t *oldset,
410		     struct pt_regs *regs)
411{
412	int ret;
413
414	/* Set up the stack frame */
415	if (ksig->ka.sa.sa_flags & SA_SIGINFO)
416		ret = setup_rt_frame32(ksig, oldset, regs);
417	else
418		ret = setup_frame32(ksig, oldset, regs);
419
420	signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLE_STEP));
421}
422
v4.10.11
 
  1/*
  2 *    Copyright IBM Corp. 2000, 2006
  3 *    Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
  4 *               Gerhard Tonn (ton@de.ibm.com)                  
  5 *
  6 *  Copyright (C) 1991, 1992  Linus Torvalds
  7 *
  8 *  1997-11-28  Modified for POSIX.1b signals by Richard Henderson
  9 */
 10
 11#include <linux/compat.h>
 12#include <linux/sched.h>
 
 13#include <linux/mm.h>
 14#include <linux/smp.h>
 15#include <linux/kernel.h>
 16#include <linux/signal.h>
 17#include <linux/errno.h>
 18#include <linux/wait.h>
 19#include <linux/ptrace.h>
 20#include <linux/unistd.h>
 21#include <linux/stddef.h>
 22#include <linux/tty.h>
 23#include <linux/personality.h>
 24#include <linux/binfmts.h>
 25#include <asm/ucontext.h>
 26#include <linux/uaccess.h>
 27#include <asm/lowcore.h>
 28#include <asm/switch_to.h>
 
 29#include "compat_linux.h"
 30#include "compat_ptrace.h"
 31#include "entry.h"
 32
 33typedef struct 
 34{
 35	__u8 callee_used_stack[__SIGNAL_FRAMESIZE32];
 36	struct sigcontext32 sc;
 37	_sigregs32 sregs;
 38	int signo;
 39	_sigregs_ext32 sregs_ext;
 40	__u16 svc_insn;		/* Offset of svc_insn is NOT fixed! */
 41} sigframe32;
 42
 43typedef struct 
 44{
 45	__u8 callee_used_stack[__SIGNAL_FRAMESIZE32];
 46	__u16 svc_insn;
 47	compat_siginfo_t info;
 48	struct ucontext32 uc;
 49} rt_sigframe32;
 50
 51static inline void sigset_to_sigset32(unsigned long *set64,
 52				      compat_sigset_word *set32)
 53{
 54	set32[0] = (compat_sigset_word) set64[0];
 55	set32[1] = (compat_sigset_word)(set64[0] >> 32);
 56}
 57
 58static inline void sigset32_to_sigset(compat_sigset_word *set32,
 59				      unsigned long *set64)
 60{
 61	set64[0] = (unsigned long) set32[0] | ((unsigned long) set32[1] << 32);
 62}
 63
 64int copy_siginfo_to_user32(compat_siginfo_t __user *to, const siginfo_t *from)
 65{
 66	int err;
 67
 68	/* If you change siginfo_t structure, please be sure
 69	   this code is fixed accordingly.
 70	   It should never copy any pad contained in the structure
 71	   to avoid security leaks, but must copy the generic
 72	   3 ints plus the relevant union member.  
 73	   This routine must convert siginfo from 64bit to 32bit as well
 74	   at the same time.  */
 75	err = __put_user(from->si_signo, &to->si_signo);
 76	err |= __put_user(from->si_errno, &to->si_errno);
 77	err |= __put_user((short)from->si_code, &to->si_code);
 78	if (from->si_code < 0)
 79		err |= __copy_to_user(&to->_sifields._pad, &from->_sifields._pad, SI_PAD_SIZE);
 80	else {
 81		switch (from->si_code >> 16) {
 82		case __SI_RT >> 16: /* This is not generated by the kernel as of now.  */
 83		case __SI_MESGQ >> 16:
 84			err |= __put_user(from->si_int, &to->si_int);
 85			/* fallthrough */
 86		case __SI_KILL >> 16:
 87			err |= __put_user(from->si_pid, &to->si_pid);
 88			err |= __put_user(from->si_uid, &to->si_uid);
 89			break;
 90		case __SI_CHLD >> 16:
 91			err |= __put_user(from->si_pid, &to->si_pid);
 92			err |= __put_user(from->si_uid, &to->si_uid);
 93			err |= __put_user(from->si_utime, &to->si_utime);
 94			err |= __put_user(from->si_stime, &to->si_stime);
 95			err |= __put_user(from->si_status, &to->si_status);
 96			break;
 97		case __SI_FAULT >> 16:
 98			err |= __put_user((unsigned long) from->si_addr,
 99					  &to->si_addr);
100			break;
101		case __SI_POLL >> 16:
102			err |= __put_user(from->si_band, &to->si_band);
103			err |= __put_user(from->si_fd, &to->si_fd);
104			break;
105		case __SI_TIMER >> 16:
106			err |= __put_user(from->si_tid, &to->si_tid);
107			err |= __put_user(from->si_overrun, &to->si_overrun);
108			err |= __put_user(from->si_int, &to->si_int);
109			break;
110		default:
111			break;
112		}
113	}
114	return err ? -EFAULT : 0;
115}
116
117int copy_siginfo_from_user32(siginfo_t *to, compat_siginfo_t __user *from)
118{
119	int err;
120	u32 tmp;
121
122	err = __get_user(to->si_signo, &from->si_signo);
123	err |= __get_user(to->si_errno, &from->si_errno);
124	err |= __get_user(to->si_code, &from->si_code);
125
126	if (to->si_code < 0)
127		err |= __copy_from_user(&to->_sifields._pad, &from->_sifields._pad, SI_PAD_SIZE);
128	else {
129		switch (to->si_code >> 16) {
130		case __SI_RT >> 16: /* This is not generated by the kernel as of now.  */
131		case __SI_MESGQ >> 16:
132			err |= __get_user(to->si_int, &from->si_int);
133			/* fallthrough */
134		case __SI_KILL >> 16:
135			err |= __get_user(to->si_pid, &from->si_pid);
136			err |= __get_user(to->si_uid, &from->si_uid);
137			break;
138		case __SI_CHLD >> 16:
139			err |= __get_user(to->si_pid, &from->si_pid);
140			err |= __get_user(to->si_uid, &from->si_uid);
141			err |= __get_user(to->si_utime, &from->si_utime);
142			err |= __get_user(to->si_stime, &from->si_stime);
143			err |= __get_user(to->si_status, &from->si_status);
144			break;
145		case __SI_FAULT >> 16:
146			err |= __get_user(tmp, &from->si_addr);
147			to->si_addr = (void __force __user *)
148				(u64) (tmp & PSW32_ADDR_INSN);
149			break;
150		case __SI_POLL >> 16:
151			err |= __get_user(to->si_band, &from->si_band);
152			err |= __get_user(to->si_fd, &from->si_fd);
153			break;
154		case __SI_TIMER >> 16:
155			err |= __get_user(to->si_tid, &from->si_tid);
156			err |= __get_user(to->si_overrun, &from->si_overrun);
157			err |= __get_user(to->si_int, &from->si_int);
158			break;
159		default:
160			break;
161		}
162	}
163	return err ? -EFAULT : 0;
164}
165
166/* Store registers needed to create the signal frame */
167static void store_sigregs(void)
168{
169	save_access_regs(current->thread.acrs);
170	save_fpu_regs();
171}
172
173/* Load registers after signal return */
174static void load_sigregs(void)
175{
176	restore_access_regs(current->thread.acrs);
177}
178
179static int save_sigregs32(struct pt_regs *regs, _sigregs32 __user *sregs)
180{
181	_sigregs32 user_sregs;
182	int i;
183
184	user_sregs.regs.psw.mask = (__u32)(regs->psw.mask >> 32);
185	user_sregs.regs.psw.mask &= PSW32_MASK_USER | PSW32_MASK_RI;
186	user_sregs.regs.psw.mask |= PSW32_USER_BITS;
187	user_sregs.regs.psw.addr = (__u32) regs->psw.addr |
188		(__u32)(regs->psw.mask & PSW_MASK_BA);
189	for (i = 0; i < NUM_GPRS; i++)
190		user_sregs.regs.gprs[i] = (__u32) regs->gprs[i];
191	memcpy(&user_sregs.regs.acrs, current->thread.acrs,
192	       sizeof(user_sregs.regs.acrs));
193	fpregs_store((_s390_fp_regs *) &user_sregs.fpregs, &current->thread.fpu);
194	if (__copy_to_user(sregs, &user_sregs, sizeof(_sigregs32)))
195		return -EFAULT;
196	return 0;
197}
198
199static int restore_sigregs32(struct pt_regs *regs,_sigregs32 __user *sregs)
200{
201	_sigregs32 user_sregs;
202	int i;
203
204	/* Alwys make any pending restarted system call return -EINTR */
205	current->restart_block.fn = do_no_restart_syscall;
206
207	if (__copy_from_user(&user_sregs, &sregs->regs, sizeof(user_sregs)))
208		return -EFAULT;
209
210	if (!is_ri_task(current) && (user_sregs.regs.psw.mask & PSW32_MASK_RI))
211		return -EINVAL;
212
213	/* Test the floating-point-control word. */
214	if (test_fp_ctl(user_sregs.fpregs.fpc))
215		return -EINVAL;
216
217	/* Use regs->psw.mask instead of PSW_USER_BITS to preserve PER bit. */
218	regs->psw.mask = (regs->psw.mask & ~(PSW_MASK_USER | PSW_MASK_RI)) |
219		(__u64)(user_sregs.regs.psw.mask & PSW32_MASK_USER) << 32 |
220		(__u64)(user_sregs.regs.psw.mask & PSW32_MASK_RI) << 32 |
221		(__u64)(user_sregs.regs.psw.addr & PSW32_ADDR_AMODE);
222	/* Check for invalid user address space control. */
223	if ((regs->psw.mask & PSW_MASK_ASC) == PSW_ASC_HOME)
224		regs->psw.mask = PSW_ASC_PRIMARY |
225			(regs->psw.mask & ~PSW_MASK_ASC);
226	regs->psw.addr = (__u64)(user_sregs.regs.psw.addr & PSW32_ADDR_INSN);
227	for (i = 0; i < NUM_GPRS; i++)
228		regs->gprs[i] = (__u64) user_sregs.regs.gprs[i];
229	memcpy(&current->thread.acrs, &user_sregs.regs.acrs,
230	       sizeof(current->thread.acrs));
231	fpregs_load((_s390_fp_regs *) &user_sregs.fpregs, &current->thread.fpu);
232
233	clear_pt_regs_flag(regs, PIF_SYSCALL); /* No longer in a system call */
234	return 0;
235}
236
237static int save_sigregs_ext32(struct pt_regs *regs,
238			      _sigregs_ext32 __user *sregs_ext)
239{
240	__u32 gprs_high[NUM_GPRS];
241	__u64 vxrs[__NUM_VXRS_LOW];
242	int i;
243
244	/* Save high gprs to signal stack */
245	for (i = 0; i < NUM_GPRS; i++)
246		gprs_high[i] = regs->gprs[i] >> 32;
247	if (__copy_to_user(&sregs_ext->gprs_high, &gprs_high,
248			   sizeof(sregs_ext->gprs_high)))
249		return -EFAULT;
250
251	/* Save vector registers to signal stack */
252	if (MACHINE_HAS_VX) {
253		for (i = 0; i < __NUM_VXRS_LOW; i++)
254			vxrs[i] = *((__u64 *)(current->thread.fpu.vxrs + i) + 1);
255		if (__copy_to_user(&sregs_ext->vxrs_low, vxrs,
256				   sizeof(sregs_ext->vxrs_low)) ||
257		    __copy_to_user(&sregs_ext->vxrs_high,
258				   current->thread.fpu.vxrs + __NUM_VXRS_LOW,
259				   sizeof(sregs_ext->vxrs_high)))
260			return -EFAULT;
261	}
262	return 0;
263}
264
265static int restore_sigregs_ext32(struct pt_regs *regs,
266				 _sigregs_ext32 __user *sregs_ext)
267{
268	__u32 gprs_high[NUM_GPRS];
269	__u64 vxrs[__NUM_VXRS_LOW];
270	int i;
271
272	/* Restore high gprs from signal stack */
273	if (__copy_from_user(&gprs_high, &sregs_ext->gprs_high,
274			     sizeof(sregs_ext->gprs_high)))
275		return -EFAULT;
276	for (i = 0; i < NUM_GPRS; i++)
277		*(__u32 *)&regs->gprs[i] = gprs_high[i];
278
279	/* Restore vector registers from signal stack */
280	if (MACHINE_HAS_VX) {
281		if (__copy_from_user(vxrs, &sregs_ext->vxrs_low,
282				     sizeof(sregs_ext->vxrs_low)) ||
283		    __copy_from_user(current->thread.fpu.vxrs + __NUM_VXRS_LOW,
284				     &sregs_ext->vxrs_high,
285				     sizeof(sregs_ext->vxrs_high)))
286			return -EFAULT;
287		for (i = 0; i < __NUM_VXRS_LOW; i++)
288			*((__u64 *)(current->thread.fpu.vxrs + i) + 1) = vxrs[i];
289	}
290	return 0;
291}
292
293COMPAT_SYSCALL_DEFINE0(sigreturn)
294{
295	struct pt_regs *regs = task_pt_regs(current);
296	sigframe32 __user *frame = (sigframe32 __user *)regs->gprs[15];
297	compat_sigset_t cset;
298	sigset_t set;
299
300	if (__copy_from_user(&cset.sig, &frame->sc.oldmask, _SIGMASK_COPY_SIZE32))
301		goto badframe;
302	sigset32_to_sigset(cset.sig, set.sig);
303	set_current_blocked(&set);
304	save_fpu_regs();
305	if (restore_sigregs32(regs, &frame->sregs))
306		goto badframe;
307	if (restore_sigregs_ext32(regs, &frame->sregs_ext))
308		goto badframe;
309	load_sigregs();
310	return regs->gprs[2];
311badframe:
312	force_sig(SIGSEGV, current);
313	return 0;
314}
315
316COMPAT_SYSCALL_DEFINE0(rt_sigreturn)
317{
318	struct pt_regs *regs = task_pt_regs(current);
319	rt_sigframe32 __user *frame = (rt_sigframe32 __user *)regs->gprs[15];
320	compat_sigset_t cset;
321	sigset_t set;
322
323	if (__copy_from_user(&cset, &frame->uc.uc_sigmask, sizeof(cset)))
324		goto badframe;
325	sigset32_to_sigset(cset.sig, set.sig);
326	set_current_blocked(&set);
327	if (compat_restore_altstack(&frame->uc.uc_stack))
328		goto badframe;
329	save_fpu_regs();
330	if (restore_sigregs32(regs, &frame->uc.uc_mcontext))
331		goto badframe;
332	if (restore_sigregs_ext32(regs, &frame->uc.uc_mcontext_ext))
333		goto badframe;
334	load_sigregs();
335	return regs->gprs[2];
336badframe:
337	force_sig(SIGSEGV, current);
338	return 0;
339}	
340
341/*
342 * Set up a signal frame.
343 */
344
345
346/*
347 * Determine which stack to use..
348 */
349static inline void __user *
350get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size)
351{
352	unsigned long sp;
353
354	/* Default to using normal stack */
355	sp = (unsigned long) A(regs->gprs[15]);
356
357	/* Overflow on alternate signal stack gives SIGSEGV. */
358	if (on_sig_stack(sp) && !on_sig_stack((sp - frame_size) & -8UL))
359		return (void __user *) -1UL;
360
361	/* This is the X/Open sanctioned signal stack switching.  */
362	if (ka->sa.sa_flags & SA_ONSTACK) {
363		if (! sas_ss_flags(sp))
364			sp = current->sas_ss_sp + current->sas_ss_size;
365	}
366
367	return (void __user *)((sp - frame_size) & -8ul);
368}
369
370static int setup_frame32(struct ksignal *ksig, sigset_t *set,
371			 struct pt_regs *regs)
372{
373	int sig = ksig->sig;
374	sigframe32 __user *frame;
375	struct sigcontext32 sc;
376	unsigned long restorer;
377	size_t frame_size;
378
379	/*
380	 * gprs_high are always present for 31-bit compat tasks.
381	 * The space for vector registers is only allocated if
382	 * the machine supports it
383	 */
384	frame_size = sizeof(*frame) - sizeof(frame->sregs_ext.__reserved);
385	if (!MACHINE_HAS_VX)
386		frame_size -= sizeof(frame->sregs_ext.vxrs_low) +
387			      sizeof(frame->sregs_ext.vxrs_high);
388	frame = get_sigframe(&ksig->ka, regs, frame_size);
389	if (frame == (void __user *) -1UL)
390		return -EFAULT;
391
392	/* Set up backchain. */
393	if (__put_user(regs->gprs[15], (unsigned int __user *) frame))
394		return -EFAULT;
395
396	/* Create struct sigcontext32 on the signal stack */
397	sigset_to_sigset32(set->sig, sc.oldmask);
398	sc.sregs = (__u32)(unsigned long __force) &frame->sregs;
399	if (__copy_to_user(&frame->sc, &sc, sizeof(frame->sc)))
 
400		return -EFAULT;
401
402	/* Store registers needed to create the signal frame */
403	store_sigregs();
404
405	/* Create _sigregs32 on the signal stack */
406	if (save_sigregs32(regs, &frame->sregs))
407		return -EFAULT;
408
409	/* Place signal number on stack to allow backtrace from handler.  */
410	if (__put_user(regs->gprs[2], (int __force __user *) &frame->signo))
411		return -EFAULT;
412
413	/* Create _sigregs_ext32 on the signal stack */
414	if (save_sigregs_ext32(regs, &frame->sregs_ext))
415		return -EFAULT;
416
417	/* Set up to return from userspace.  If provided, use a stub
418	   already in userspace.  */
419	if (ksig->ka.sa.sa_flags & SA_RESTORER) {
420		restorer = (unsigned long __force)
421			ksig->ka.sa.sa_restorer | PSW32_ADDR_AMODE;
422	} else {
423		/* Signal frames without vectors registers are short ! */
424		__u16 __user *svc = (void __user *) frame + frame_size - 2;
425		if (__put_user(S390_SYSCALL_OPCODE | __NR_sigreturn, svc))
426			return -EFAULT;
427		restorer = (unsigned long __force) svc | PSW32_ADDR_AMODE;
428        }
429
430	/* Set up registers for signal handler */
431	regs->gprs[14] = restorer;
432	regs->gprs[15] = (__force __u64) frame;
433	/* Force 31 bit amode and default user address space control. */
434	regs->psw.mask = PSW_MASK_BA |
435		(PSW_USER_BITS & PSW_MASK_ASC) |
436		(regs->psw.mask & ~PSW_MASK_ASC);
437	regs->psw.addr = (__force __u64) ksig->ka.sa.sa_handler;
438
439	regs->gprs[2] = sig;
440	regs->gprs[3] = (__force __u64) &frame->sc;
441
442	/* We forgot to include these in the sigcontext.
443	   To avoid breaking binary compatibility, they are passed as args. */
444	if (sig == SIGSEGV || sig == SIGBUS || sig == SIGILL ||
445	    sig == SIGTRAP || sig == SIGFPE) {
446		/* set extra registers only for synchronous signals */
447		regs->gprs[4] = regs->int_code & 127;
448		regs->gprs[5] = regs->int_parm_long;
449		regs->gprs[6] = current->thread.last_break;
450	}
451
452	return 0;
453}
454
455static int setup_rt_frame32(struct ksignal *ksig, sigset_t *set,
456			    struct pt_regs *regs)
457{
458	compat_sigset_t cset;
459	rt_sigframe32 __user *frame;
460	unsigned long restorer;
461	size_t frame_size;
462	u32 uc_flags;
463
464	frame_size = sizeof(*frame) -
465		     sizeof(frame->uc.uc_mcontext_ext.__reserved);
466	/*
467	 * gprs_high are always present for 31-bit compat tasks.
468	 * The space for vector registers is only allocated if
469	 * the machine supports it
470	 */
471	uc_flags = UC_GPRS_HIGH;
472	if (MACHINE_HAS_VX) {
473		uc_flags |= UC_VXRS;
474	} else
475		frame_size -= sizeof(frame->uc.uc_mcontext_ext.vxrs_low) +
476			      sizeof(frame->uc.uc_mcontext_ext.vxrs_high);
477	frame = get_sigframe(&ksig->ka, regs, frame_size);
478	if (frame == (void __user *) -1UL)
479		return -EFAULT;
480
481	/* Set up backchain. */
482	if (__put_user(regs->gprs[15], (unsigned int __force __user *) frame))
483		return -EFAULT;
484
485	/* Set up to return from userspace.  If provided, use a stub
486	   already in userspace.  */
487	if (ksig->ka.sa.sa_flags & SA_RESTORER) {
488		restorer = (unsigned long __force)
489			ksig->ka.sa.sa_restorer | PSW32_ADDR_AMODE;
490	} else {
491		__u16 __user *svc = &frame->svc_insn;
492		if (__put_user(S390_SYSCALL_OPCODE | __NR_rt_sigreturn, svc))
493			return -EFAULT;
494		restorer = (unsigned long __force) svc | PSW32_ADDR_AMODE;
495	}
496
497	/* Create siginfo on the signal stack */
498	if (copy_siginfo_to_user32(&frame->info, &ksig->info))
499		return -EFAULT;
500
501	/* Store registers needed to create the signal frame */
502	store_sigregs();
503
504	/* Create ucontext on the signal stack. */
505	sigset_to_sigset32(set->sig, cset.sig);
506	if (__put_user(uc_flags, &frame->uc.uc_flags) ||
507	    __put_user(0, &frame->uc.uc_link) ||
508	    __compat_save_altstack(&frame->uc.uc_stack, regs->gprs[15]) ||
509	    save_sigregs32(regs, &frame->uc.uc_mcontext) ||
510	    __copy_to_user(&frame->uc.uc_sigmask, &cset, sizeof(cset)) ||
511	    save_sigregs_ext32(regs, &frame->uc.uc_mcontext_ext))
512		return -EFAULT;
513
514	/* Set up registers for signal handler */
515	regs->gprs[14] = restorer;
516	regs->gprs[15] = (__force __u64) frame;
517	/* Force 31 bit amode and default user address space control. */
518	regs->psw.mask = PSW_MASK_BA |
519		(PSW_USER_BITS & PSW_MASK_ASC) |
520		(regs->psw.mask & ~PSW_MASK_ASC);
521	regs->psw.addr = (__u64 __force) ksig->ka.sa.sa_handler;
522
523	regs->gprs[2] = ksig->sig;
524	regs->gprs[3] = (__force __u64) &frame->info;
525	regs->gprs[4] = (__force __u64) &frame->uc;
526	regs->gprs[5] = current->thread.last_break;
527	return 0;
528}
529
530/*
531 * OK, we're invoking a handler
532 */	
533
534void handle_signal32(struct ksignal *ksig, sigset_t *oldset,
535		     struct pt_regs *regs)
536{
537	int ret;
538
539	/* Set up the stack frame */
540	if (ksig->ka.sa.sa_flags & SA_SIGINFO)
541		ret = setup_rt_frame32(ksig, oldset, regs);
542	else
543		ret = setup_frame32(ksig, oldset, regs);
544
545	signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLE_STEP));
546}
547