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v5.4
  1/*
  2 * Copyright (C) 2003 PathScale, Inc.
  3 * Copyright (C) 2003 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
  4 * Licensed under the GPL
  5 */
  6
  7
  8#include <linux/personality.h>
  9#include <linux/ptrace.h>
 10#include <linux/kernel.h>
 11#include <asm/unistd.h>
 12#include <linux/uaccess.h>
 13#include <asm/ucontext.h>
 14#include <frame_kern.h>
 15#include <skas.h>
 16
 17#ifdef CONFIG_X86_32
 18
 19/*
 20 * FPU tag word conversions.
 21 */
 22
 23static inline unsigned short twd_i387_to_fxsr(unsigned short twd)
 24{
 25	unsigned int tmp; /* to avoid 16 bit prefixes in the code */
 26
 27	/* Transform each pair of bits into 01 (valid) or 00 (empty) */
 28	tmp = ~twd;
 29	tmp = (tmp | (tmp>>1)) & 0x5555; /* 0V0V0V0V0V0V0V0V */
 30	/* and move the valid bits to the lower byte. */
 31	tmp = (tmp | (tmp >> 1)) & 0x3333; /* 00VV00VV00VV00VV */
 32	tmp = (tmp | (tmp >> 2)) & 0x0f0f; /* 0000VVVV0000VVVV */
 33	tmp = (tmp | (tmp >> 4)) & 0x00ff; /* 00000000VVVVVVVV */
 34	return tmp;
 35}
 36
 37static inline unsigned long twd_fxsr_to_i387(struct user_fxsr_struct *fxsave)
 38{
 39	struct _fpxreg *st = NULL;
 40	unsigned long twd = (unsigned long) fxsave->twd;
 41	unsigned long tag;
 42	unsigned long ret = 0xffff0000;
 43	int i;
 44
 45#define FPREG_ADDR(f, n)	((char *)&(f)->st_space + (n) * 16)
 46
 47	for (i = 0; i < 8; i++) {
 48		if (twd & 0x1) {
 49			st = (struct _fpxreg *) FPREG_ADDR(fxsave, i);
 50
 51			switch (st->exponent & 0x7fff) {
 52			case 0x7fff:
 53				tag = 2;		/* Special */
 54				break;
 55			case 0x0000:
 56				if ( !st->significand[0] &&
 57				     !st->significand[1] &&
 58				     !st->significand[2] &&
 59				     !st->significand[3] ) {
 60					tag = 1;	/* Zero */
 61				} else {
 62					tag = 2;	/* Special */
 63				}
 64				break;
 65			default:
 66				if (st->significand[3] & 0x8000) {
 67					tag = 0;	/* Valid */
 68				} else {
 69					tag = 2;	/* Special */
 70				}
 71				break;
 72			}
 73		} else {
 74			tag = 3;			/* Empty */
 75		}
 76		ret |= (tag << (2 * i));
 77		twd = twd >> 1;
 78	}
 79	return ret;
 80}
 81
 82static int convert_fxsr_to_user(struct _fpstate __user *buf,
 83				struct user_fxsr_struct *fxsave)
 84{
 85	unsigned long env[7];
 86	struct _fpreg __user *to;
 87	struct _fpxreg *from;
 88	int i;
 89
 90	env[0] = (unsigned long)fxsave->cwd | 0xffff0000ul;
 91	env[1] = (unsigned long)fxsave->swd | 0xffff0000ul;
 92	env[2] = twd_fxsr_to_i387(fxsave);
 93	env[3] = fxsave->fip;
 94	env[4] = fxsave->fcs | ((unsigned long)fxsave->fop << 16);
 95	env[5] = fxsave->foo;
 96	env[6] = fxsave->fos;
 97
 98	if (__copy_to_user(buf, env, 7 * sizeof(unsigned long)))
 99		return 1;
100
101	to = &buf->_st[0];
102	from = (struct _fpxreg *) &fxsave->st_space[0];
103	for (i = 0; i < 8; i++, to++, from++) {
104		unsigned long __user *t = (unsigned long __user *)to;
105		unsigned long *f = (unsigned long *)from;
106
107		if (__put_user(*f, t) ||
108				__put_user(*(f + 1), t + 1) ||
109				__put_user(from->exponent, &to->exponent))
110			return 1;
111	}
112	return 0;
113}
114
115static int convert_fxsr_from_user(struct user_fxsr_struct *fxsave,
116				  struct _fpstate __user *buf)
117{
118	unsigned long env[7];
119	struct _fpxreg *to;
120	struct _fpreg __user *from;
121	int i;
122
123	if (copy_from_user( env, buf, 7 * sizeof(long)))
124		return 1;
125
126	fxsave->cwd = (unsigned short)(env[0] & 0xffff);
127	fxsave->swd = (unsigned short)(env[1] & 0xffff);
128	fxsave->twd = twd_i387_to_fxsr((unsigned short)(env[2] & 0xffff));
129	fxsave->fip = env[3];
130	fxsave->fop = (unsigned short)((env[4] & 0xffff0000ul) >> 16);
131	fxsave->fcs = (env[4] & 0xffff);
132	fxsave->foo = env[5];
133	fxsave->fos = env[6];
134
135	to = (struct _fpxreg *) &fxsave->st_space[0];
136	from = &buf->_st[0];
137	for (i = 0; i < 8; i++, to++, from++) {
138		unsigned long *t = (unsigned long *)to;
139		unsigned long __user *f = (unsigned long __user *)from;
140
141		if (__get_user(*t, f) ||
142		    __get_user(*(t + 1), f + 1) ||
143		    __get_user(to->exponent, &from->exponent))
144			return 1;
145	}
146	return 0;
147}
148
149extern int have_fpx_regs;
150
151#endif
152
153static int copy_sc_from_user(struct pt_regs *regs,
154			     struct sigcontext __user *from)
155{
156	struct sigcontext sc;
157	int err, pid;
158
159	/* Always make any pending restarted system calls return -EINTR */
160	current->restart_block.fn = do_no_restart_syscall;
161
162	err = copy_from_user(&sc, from, sizeof(sc));
163	if (err)
164		return err;
165
166#define GETREG(regno, regname) regs->regs.gp[HOST_##regno] = sc.regname
167
168#ifdef CONFIG_X86_32
169	GETREG(GS, gs);
170	GETREG(FS, fs);
171	GETREG(ES, es);
172	GETREG(DS, ds);
173#endif
174	GETREG(DI, di);
175	GETREG(SI, si);
176	GETREG(BP, bp);
177	GETREG(SP, sp);
178	GETREG(BX, bx);
179	GETREG(DX, dx);
180	GETREG(CX, cx);
181	GETREG(AX, ax);
182	GETREG(IP, ip);
183
184#ifdef CONFIG_X86_64
185	GETREG(R8, r8);
186	GETREG(R9, r9);
187	GETREG(R10, r10);
188	GETREG(R11, r11);
189	GETREG(R12, r12);
190	GETREG(R13, r13);
191	GETREG(R14, r14);
192	GETREG(R15, r15);
193#endif
194
195	GETREG(CS, cs);
196	GETREG(EFLAGS, flags);
197#ifdef CONFIG_X86_32
198	GETREG(SS, ss);
199#endif
200
201#undef GETREG
202
203	pid = userspace_pid[current_thread_info()->cpu];
204#ifdef CONFIG_X86_32
205	if (have_fpx_regs) {
206		struct user_fxsr_struct fpx;
207
208		err = copy_from_user(&fpx,
209			&((struct _fpstate __user *)sc.fpstate)->_fxsr_env[0],
210				     sizeof(struct user_fxsr_struct));
211		if (err)
212			return 1;
213
214		err = convert_fxsr_from_user(&fpx, (void *)sc.fpstate);
215		if (err)
216			return 1;
217
218		err = restore_fpx_registers(pid, (unsigned long *) &fpx);
219		if (err < 0) {
220			printk(KERN_ERR "copy_sc_from_user - "
221			       "restore_fpx_registers failed, errno = %d\n",
222			       -err);
223			return 1;
224		}
225	} else
226#endif
227	{
228		err = copy_from_user(regs->regs.fp, (void *)sc.fpstate,
229				     sizeof(struct _xstate));
230		if (err)
231			return 1;
232	}
233	return 0;
234}
235
236static int copy_sc_to_user(struct sigcontext __user *to,
237			   struct _xstate __user *to_fp, struct pt_regs *regs,
238			   unsigned long mask)
239{
240	struct sigcontext sc;
241	struct faultinfo * fi = &current->thread.arch.faultinfo;
242	int err, pid;
243	memset(&sc, 0, sizeof(struct sigcontext));
244
245#define PUTREG(regno, regname) sc.regname = regs->regs.gp[HOST_##regno]
246
247#ifdef CONFIG_X86_32
248	PUTREG(GS, gs);
249	PUTREG(FS, fs);
250	PUTREG(ES, es);
251	PUTREG(DS, ds);
252#endif
253	PUTREG(DI, di);
254	PUTREG(SI, si);
255	PUTREG(BP, bp);
256	PUTREG(SP, sp);
257	PUTREG(BX, bx);
258	PUTREG(DX, dx);
259	PUTREG(CX, cx);
260	PUTREG(AX, ax);
261#ifdef CONFIG_X86_64
262	PUTREG(R8, r8);
263	PUTREG(R9, r9);
264	PUTREG(R10, r10);
265	PUTREG(R11, r11);
266	PUTREG(R12, r12);
267	PUTREG(R13, r13);
268	PUTREG(R14, r14);
269	PUTREG(R15, r15);
270#endif
271
272	sc.cr2 = fi->cr2;
273	sc.err = fi->error_code;
274	sc.trapno = fi->trap_no;
275	PUTREG(IP, ip);
276	PUTREG(CS, cs);
277	PUTREG(EFLAGS, flags);
278#ifdef CONFIG_X86_32
279	PUTREG(SP, sp_at_signal);
280	PUTREG(SS, ss);
281#endif
282#undef PUTREG
283	sc.oldmask = mask;
284	sc.fpstate = (unsigned long)to_fp;
285
286	err = copy_to_user(to, &sc, sizeof(struct sigcontext));
287	if (err)
288		return 1;
289
290	pid = userspace_pid[current_thread_info()->cpu];
291
292#ifdef CONFIG_X86_32
293	if (have_fpx_regs) {
294		struct user_fxsr_struct fpx;
295
296		err = save_fpx_registers(pid, (unsigned long *) &fpx);
297		if (err < 0){
298			printk(KERN_ERR "copy_sc_to_user - save_fpx_registers "
299			       "failed, errno = %d\n", err);
300			return 1;
301		}
302
303		err = convert_fxsr_to_user(&to_fp->fpstate, &fpx);
304		if (err)
305			return 1;
306
307		err |= __put_user(fpx.swd, &to_fp->fpstate.status);
308		err |= __put_user(X86_FXSR_MAGIC, &to_fp->fpstate.magic);
309		if (err)
310			return 1;
311
312		if (copy_to_user(&to_fp->fpstate._fxsr_env[0], &fpx,
313				 sizeof(struct user_fxsr_struct)))
314			return 1;
315	} else
316#endif
317	{
318		if (copy_to_user(to_fp, regs->regs.fp, sizeof(struct _xstate)))
319			return 1;
320	}
321
322	return 0;
323}
324
325#ifdef CONFIG_X86_32
326static int copy_ucontext_to_user(struct ucontext __user *uc,
327				 struct _xstate __user *fp, sigset_t *set,
328				 unsigned long sp)
329{
330	int err = 0;
331
332	err |= __save_altstack(&uc->uc_stack, sp);
333	err |= copy_sc_to_user(&uc->uc_mcontext, fp, &current->thread.regs, 0);
334	err |= copy_to_user(&uc->uc_sigmask, set, sizeof(*set));
335	return err;
336}
337
338struct sigframe
339{
340	char __user *pretcode;
341	int sig;
342	struct sigcontext sc;
343	struct _xstate fpstate;
344	unsigned long extramask[_NSIG_WORDS-1];
345	char retcode[8];
346};
347
348struct rt_sigframe
349{
350	char __user *pretcode;
351	int sig;
352	struct siginfo __user *pinfo;
353	void __user *puc;
354	struct siginfo info;
355	struct ucontext uc;
356	struct _xstate fpstate;
357	char retcode[8];
358};
359
360int setup_signal_stack_sc(unsigned long stack_top, struct ksignal *ksig,
361			  struct pt_regs *regs, sigset_t *mask)
362{
363	struct sigframe __user *frame;
364	void __user *restorer;
365	int err = 0, sig = ksig->sig;
366
367	/* This is the same calculation as i386 - ((sp + 4) & 15) == 0 */
368	stack_top = ((stack_top + 4) & -16UL) - 4;
369	frame = (struct sigframe __user *) stack_top - 1;
370	if (!access_ok(frame, sizeof(*frame)))
371		return 1;
372
373	restorer = frame->retcode;
374	if (ksig->ka.sa.sa_flags & SA_RESTORER)
375		restorer = ksig->ka.sa.sa_restorer;
376
377	err |= __put_user(restorer, &frame->pretcode);
378	err |= __put_user(sig, &frame->sig);
379	err |= copy_sc_to_user(&frame->sc, &frame->fpstate, regs, mask->sig[0]);
380	if (_NSIG_WORDS > 1)
381		err |= __copy_to_user(&frame->extramask, &mask->sig[1],
382				      sizeof(frame->extramask));
383
384	/*
385	 * This is popl %eax ; movl $,%eax ; int $0x80
386	 *
387	 * WE DO NOT USE IT ANY MORE! It's only left here for historical
388	 * reasons and because gdb uses it as a signature to notice
389	 * signal handler stack frames.
390	 */
391	err |= __put_user(0xb858, (short __user *)(frame->retcode+0));
392	err |= __put_user(__NR_sigreturn, (int __user *)(frame->retcode+2));
393	err |= __put_user(0x80cd, (short __user *)(frame->retcode+6));
394
395	if (err)
396		return err;
397
398	PT_REGS_SP(regs) = (unsigned long) frame;
399	PT_REGS_IP(regs) = (unsigned long) ksig->ka.sa.sa_handler;
400	PT_REGS_AX(regs) = (unsigned long) sig;
401	PT_REGS_DX(regs) = (unsigned long) 0;
402	PT_REGS_CX(regs) = (unsigned long) 0;
403	return 0;
404}
405
406int setup_signal_stack_si(unsigned long stack_top, struct ksignal *ksig,
407			  struct pt_regs *regs, sigset_t *mask)
408{
409	struct rt_sigframe __user *frame;
410	void __user *restorer;
411	int err = 0, sig = ksig->sig;
412
413	stack_top &= -8UL;
414	frame = (struct rt_sigframe __user *) stack_top - 1;
415	if (!access_ok(frame, sizeof(*frame)))
416		return 1;
417
418	restorer = frame->retcode;
419	if (ksig->ka.sa.sa_flags & SA_RESTORER)
420		restorer = ksig->ka.sa.sa_restorer;
421
422	err |= __put_user(restorer, &frame->pretcode);
423	err |= __put_user(sig, &frame->sig);
424	err |= __put_user(&frame->info, &frame->pinfo);
425	err |= __put_user(&frame->uc, &frame->puc);
426	err |= copy_siginfo_to_user(&frame->info, &ksig->info);
427	err |= copy_ucontext_to_user(&frame->uc, &frame->fpstate, mask,
428					PT_REGS_SP(regs));
429
430	/*
431	 * This is movl $,%eax ; int $0x80
432	 *
433	 * WE DO NOT USE IT ANY MORE! It's only left here for historical
434	 * reasons and because gdb uses it as a signature to notice
435	 * signal handler stack frames.
436	 */
437	err |= __put_user(0xb8, (char __user *)(frame->retcode+0));
438	err |= __put_user(__NR_rt_sigreturn, (int __user *)(frame->retcode+1));
439	err |= __put_user(0x80cd, (short __user *)(frame->retcode+5));
440
441	if (err)
442		return err;
443
444	PT_REGS_SP(regs) = (unsigned long) frame;
445	PT_REGS_IP(regs) = (unsigned long) ksig->ka.sa.sa_handler;
446	PT_REGS_AX(regs) = (unsigned long) sig;
447	PT_REGS_DX(regs) = (unsigned long) &frame->info;
448	PT_REGS_CX(regs) = (unsigned long) &frame->uc;
449	return 0;
450}
451
452long sys_sigreturn(void)
453{
454	unsigned long sp = PT_REGS_SP(&current->thread.regs);
455	struct sigframe __user *frame = (struct sigframe __user *)(sp - 8);
456	sigset_t set;
457	struct sigcontext __user *sc = &frame->sc;
458	int sig_size = (_NSIG_WORDS - 1) * sizeof(unsigned long);
459
460	if (copy_from_user(&set.sig[0], &sc->oldmask, sizeof(set.sig[0])) ||
461	    copy_from_user(&set.sig[1], frame->extramask, sig_size))
462		goto segfault;
463
464	set_current_blocked(&set);
465
466	if (copy_sc_from_user(&current->thread.regs, sc))
467		goto segfault;
468
469	/* Avoid ERESTART handling */
470	PT_REGS_SYSCALL_NR(&current->thread.regs) = -1;
471	return PT_REGS_SYSCALL_RET(&current->thread.regs);
472
473 segfault:
474	force_sig(SIGSEGV);
475	return 0;
476}
477
478#else
479
480struct rt_sigframe
481{
482	char __user *pretcode;
483	struct ucontext uc;
484	struct siginfo info;
485	struct _xstate fpstate;
486};
487
488int setup_signal_stack_si(unsigned long stack_top, struct ksignal *ksig,
489			  struct pt_regs *regs, sigset_t *set)
490{
491	struct rt_sigframe __user *frame;
492	int err = 0, sig = ksig->sig;
493	unsigned long fp_to;
494
495	frame = (struct rt_sigframe __user *)
496		round_down(stack_top - sizeof(struct rt_sigframe), 16);
497	/* Subtract 128 for a red zone and 8 for proper alignment */
498	frame = (struct rt_sigframe __user *) ((unsigned long) frame - 128 - 8);
499
500	if (!access_ok(frame, sizeof(*frame)))
501		goto out;
502
503	if (ksig->ka.sa.sa_flags & SA_SIGINFO) {
504		err |= copy_siginfo_to_user(&frame->info, &ksig->info);
505		if (err)
506			goto out;
507	}
508
509	/* Create the ucontext.  */
510	err |= __put_user(0, &frame->uc.uc_flags);
511	err |= __put_user(0, &frame->uc.uc_link);
512	err |= __save_altstack(&frame->uc.uc_stack, PT_REGS_SP(regs));
513	err |= copy_sc_to_user(&frame->uc.uc_mcontext, &frame->fpstate, regs,
514			       set->sig[0]);
515
516	fp_to = (unsigned long)&frame->fpstate;
517
518	err |= __put_user(fp_to, &frame->uc.uc_mcontext.fpstate);
519	if (sizeof(*set) == 16) {
520		err |= __put_user(set->sig[0], &frame->uc.uc_sigmask.sig[0]);
521		err |= __put_user(set->sig[1], &frame->uc.uc_sigmask.sig[1]);
522	}
523	else
524		err |= __copy_to_user(&frame->uc.uc_sigmask, set,
525				      sizeof(*set));
526
527	/*
528	 * Set up to return from userspace.  If provided, use a stub
529	 * already in userspace.
530	 */
531	/* x86-64 should always use SA_RESTORER. */
532	if (ksig->ka.sa.sa_flags & SA_RESTORER)
533		err |= __put_user((void *)ksig->ka.sa.sa_restorer,
534				  &frame->pretcode);
535	else
536		/* could use a vstub here */
537		return err;
538
539	if (err)
540		return err;
541
542	PT_REGS_SP(regs) = (unsigned long) frame;
543	PT_REGS_DI(regs) = sig;
544	/* In case the signal handler was declared without prototypes */
545	PT_REGS_AX(regs) = 0;
546
547	/*
548	 * This also works for non SA_SIGINFO handlers because they expect the
549	 * next argument after the signal number on the stack.
550	 */
551	PT_REGS_SI(regs) = (unsigned long) &frame->info;
552	PT_REGS_DX(regs) = (unsigned long) &frame->uc;
553	PT_REGS_IP(regs) = (unsigned long) ksig->ka.sa.sa_handler;
554 out:
555	return err;
556}
557#endif
558
559long sys_rt_sigreturn(void)
560{
561	unsigned long sp = PT_REGS_SP(&current->thread.regs);
562	struct rt_sigframe __user *frame =
563		(struct rt_sigframe __user *)(sp - sizeof(long));
564	struct ucontext __user *uc = &frame->uc;
565	sigset_t set;
566
567	if (copy_from_user(&set, &uc->uc_sigmask, sizeof(set)))
568		goto segfault;
569
570	set_current_blocked(&set);
571
572	if (copy_sc_from_user(&current->thread.regs, &uc->uc_mcontext))
573		goto segfault;
574
575	/* Avoid ERESTART handling */
576	PT_REGS_SYSCALL_NR(&current->thread.regs) = -1;
577	return PT_REGS_SYSCALL_RET(&current->thread.regs);
578
579 segfault:
580	force_sig(SIGSEGV);
581	return 0;
582}
v4.17
  1/*
  2 * Copyright (C) 2003 PathScale, Inc.
  3 * Copyright (C) 2003 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
  4 * Licensed under the GPL
  5 */
  6
  7
  8#include <linux/personality.h>
  9#include <linux/ptrace.h>
 10#include <linux/kernel.h>
 11#include <asm/unistd.h>
 12#include <linux/uaccess.h>
 13#include <asm/ucontext.h>
 14#include <frame_kern.h>
 15#include <skas.h>
 16
 17#ifdef CONFIG_X86_32
 18
 19/*
 20 * FPU tag word conversions.
 21 */
 22
 23static inline unsigned short twd_i387_to_fxsr(unsigned short twd)
 24{
 25	unsigned int tmp; /* to avoid 16 bit prefixes in the code */
 26
 27	/* Transform each pair of bits into 01 (valid) or 00 (empty) */
 28	tmp = ~twd;
 29	tmp = (tmp | (tmp>>1)) & 0x5555; /* 0V0V0V0V0V0V0V0V */
 30	/* and move the valid bits to the lower byte. */
 31	tmp = (tmp | (tmp >> 1)) & 0x3333; /* 00VV00VV00VV00VV */
 32	tmp = (tmp | (tmp >> 2)) & 0x0f0f; /* 0000VVVV0000VVVV */
 33	tmp = (tmp | (tmp >> 4)) & 0x00ff; /* 00000000VVVVVVVV */
 34	return tmp;
 35}
 36
 37static inline unsigned long twd_fxsr_to_i387(struct user_fxsr_struct *fxsave)
 38{
 39	struct _fpxreg *st = NULL;
 40	unsigned long twd = (unsigned long) fxsave->twd;
 41	unsigned long tag;
 42	unsigned long ret = 0xffff0000;
 43	int i;
 44
 45#define FPREG_ADDR(f, n)	((char *)&(f)->st_space + (n) * 16)
 46
 47	for (i = 0; i < 8; i++) {
 48		if (twd & 0x1) {
 49			st = (struct _fpxreg *) FPREG_ADDR(fxsave, i);
 50
 51			switch (st->exponent & 0x7fff) {
 52			case 0x7fff:
 53				tag = 2;		/* Special */
 54				break;
 55			case 0x0000:
 56				if ( !st->significand[0] &&
 57				     !st->significand[1] &&
 58				     !st->significand[2] &&
 59				     !st->significand[3] ) {
 60					tag = 1;	/* Zero */
 61				} else {
 62					tag = 2;	/* Special */
 63				}
 64				break;
 65			default:
 66				if (st->significand[3] & 0x8000) {
 67					tag = 0;	/* Valid */
 68				} else {
 69					tag = 2;	/* Special */
 70				}
 71				break;
 72			}
 73		} else {
 74			tag = 3;			/* Empty */
 75		}
 76		ret |= (tag << (2 * i));
 77		twd = twd >> 1;
 78	}
 79	return ret;
 80}
 81
 82static int convert_fxsr_to_user(struct _fpstate __user *buf,
 83				struct user_fxsr_struct *fxsave)
 84{
 85	unsigned long env[7];
 86	struct _fpreg __user *to;
 87	struct _fpxreg *from;
 88	int i;
 89
 90	env[0] = (unsigned long)fxsave->cwd | 0xffff0000ul;
 91	env[1] = (unsigned long)fxsave->swd | 0xffff0000ul;
 92	env[2] = twd_fxsr_to_i387(fxsave);
 93	env[3] = fxsave->fip;
 94	env[4] = fxsave->fcs | ((unsigned long)fxsave->fop << 16);
 95	env[5] = fxsave->foo;
 96	env[6] = fxsave->fos;
 97
 98	if (__copy_to_user(buf, env, 7 * sizeof(unsigned long)))
 99		return 1;
100
101	to = &buf->_st[0];
102	from = (struct _fpxreg *) &fxsave->st_space[0];
103	for (i = 0; i < 8; i++, to++, from++) {
104		unsigned long __user *t = (unsigned long __user *)to;
105		unsigned long *f = (unsigned long *)from;
106
107		if (__put_user(*f, t) ||
108				__put_user(*(f + 1), t + 1) ||
109				__put_user(from->exponent, &to->exponent))
110			return 1;
111	}
112	return 0;
113}
114
115static int convert_fxsr_from_user(struct user_fxsr_struct *fxsave,
116				  struct _fpstate __user *buf)
117{
118	unsigned long env[7];
119	struct _fpxreg *to;
120	struct _fpreg __user *from;
121	int i;
122
123	if (copy_from_user( env, buf, 7 * sizeof(long)))
124		return 1;
125
126	fxsave->cwd = (unsigned short)(env[0] & 0xffff);
127	fxsave->swd = (unsigned short)(env[1] & 0xffff);
128	fxsave->twd = twd_i387_to_fxsr((unsigned short)(env[2] & 0xffff));
129	fxsave->fip = env[3];
130	fxsave->fop = (unsigned short)((env[4] & 0xffff0000ul) >> 16);
131	fxsave->fcs = (env[4] & 0xffff);
132	fxsave->foo = env[5];
133	fxsave->fos = env[6];
134
135	to = (struct _fpxreg *) &fxsave->st_space[0];
136	from = &buf->_st[0];
137	for (i = 0; i < 8; i++, to++, from++) {
138		unsigned long *t = (unsigned long *)to;
139		unsigned long __user *f = (unsigned long __user *)from;
140
141		if (__get_user(*t, f) ||
142		    __get_user(*(t + 1), f + 1) ||
143		    __get_user(to->exponent, &from->exponent))
144			return 1;
145	}
146	return 0;
147}
148
149extern int have_fpx_regs;
150
151#endif
152
153static int copy_sc_from_user(struct pt_regs *regs,
154			     struct sigcontext __user *from)
155{
156	struct sigcontext sc;
157	int err, pid;
158
159	/* Always make any pending restarted system calls return -EINTR */
160	current->restart_block.fn = do_no_restart_syscall;
161
162	err = copy_from_user(&sc, from, sizeof(sc));
163	if (err)
164		return err;
165
166#define GETREG(regno, regname) regs->regs.gp[HOST_##regno] = sc.regname
167
168#ifdef CONFIG_X86_32
169	GETREG(GS, gs);
170	GETREG(FS, fs);
171	GETREG(ES, es);
172	GETREG(DS, ds);
173#endif
174	GETREG(DI, di);
175	GETREG(SI, si);
176	GETREG(BP, bp);
177	GETREG(SP, sp);
178	GETREG(BX, bx);
179	GETREG(DX, dx);
180	GETREG(CX, cx);
181	GETREG(AX, ax);
182	GETREG(IP, ip);
183
184#ifdef CONFIG_X86_64
185	GETREG(R8, r8);
186	GETREG(R9, r9);
187	GETREG(R10, r10);
188	GETREG(R11, r11);
189	GETREG(R12, r12);
190	GETREG(R13, r13);
191	GETREG(R14, r14);
192	GETREG(R15, r15);
193#endif
194
195	GETREG(CS, cs);
196	GETREG(EFLAGS, flags);
197#ifdef CONFIG_X86_32
198	GETREG(SS, ss);
199#endif
200
201#undef GETREG
202
203	pid = userspace_pid[current_thread_info()->cpu];
204#ifdef CONFIG_X86_32
205	if (have_fpx_regs) {
206		struct user_fxsr_struct fpx;
207
208		err = copy_from_user(&fpx,
209			&((struct _fpstate __user *)sc.fpstate)->_fxsr_env[0],
210				     sizeof(struct user_fxsr_struct));
211		if (err)
212			return 1;
213
214		err = convert_fxsr_from_user(&fpx, (void *)sc.fpstate);
215		if (err)
216			return 1;
217
218		err = restore_fpx_registers(pid, (unsigned long *) &fpx);
219		if (err < 0) {
220			printk(KERN_ERR "copy_sc_from_user - "
221			       "restore_fpx_registers failed, errno = %d\n",
222			       -err);
223			return 1;
224		}
225	} else
226#endif
227	{
228		err = copy_from_user(regs->regs.fp, (void *)sc.fpstate,
229				     sizeof(struct _xstate));
230		if (err)
231			return 1;
232	}
233	return 0;
234}
235
236static int copy_sc_to_user(struct sigcontext __user *to,
237			   struct _xstate __user *to_fp, struct pt_regs *regs,
238			   unsigned long mask)
239{
240	struct sigcontext sc;
241	struct faultinfo * fi = &current->thread.arch.faultinfo;
242	int err, pid;
243	memset(&sc, 0, sizeof(struct sigcontext));
244
245#define PUTREG(regno, regname) sc.regname = regs->regs.gp[HOST_##regno]
246
247#ifdef CONFIG_X86_32
248	PUTREG(GS, gs);
249	PUTREG(FS, fs);
250	PUTREG(ES, es);
251	PUTREG(DS, ds);
252#endif
253	PUTREG(DI, di);
254	PUTREG(SI, si);
255	PUTREG(BP, bp);
256	PUTREG(SP, sp);
257	PUTREG(BX, bx);
258	PUTREG(DX, dx);
259	PUTREG(CX, cx);
260	PUTREG(AX, ax);
261#ifdef CONFIG_X86_64
262	PUTREG(R8, r8);
263	PUTREG(R9, r9);
264	PUTREG(R10, r10);
265	PUTREG(R11, r11);
266	PUTREG(R12, r12);
267	PUTREG(R13, r13);
268	PUTREG(R14, r14);
269	PUTREG(R15, r15);
270#endif
271
272	sc.cr2 = fi->cr2;
273	sc.err = fi->error_code;
274	sc.trapno = fi->trap_no;
275	PUTREG(IP, ip);
276	PUTREG(CS, cs);
277	PUTREG(EFLAGS, flags);
278#ifdef CONFIG_X86_32
279	PUTREG(SP, sp_at_signal);
280	PUTREG(SS, ss);
281#endif
282#undef PUTREG
283	sc.oldmask = mask;
284	sc.fpstate = (unsigned long)to_fp;
285
286	err = copy_to_user(to, &sc, sizeof(struct sigcontext));
287	if (err)
288		return 1;
289
290	pid = userspace_pid[current_thread_info()->cpu];
291
292#ifdef CONFIG_X86_32
293	if (have_fpx_regs) {
294		struct user_fxsr_struct fpx;
295
296		err = save_fpx_registers(pid, (unsigned long *) &fpx);
297		if (err < 0){
298			printk(KERN_ERR "copy_sc_to_user - save_fpx_registers "
299			       "failed, errno = %d\n", err);
300			return 1;
301		}
302
303		err = convert_fxsr_to_user(&to_fp->fpstate, &fpx);
304		if (err)
305			return 1;
306
307		err |= __put_user(fpx.swd, &to_fp->fpstate.status);
308		err |= __put_user(X86_FXSR_MAGIC, &to_fp->fpstate.magic);
309		if (err)
310			return 1;
311
312		if (copy_to_user(&to_fp->fpstate._fxsr_env[0], &fpx,
313				 sizeof(struct user_fxsr_struct)))
314			return 1;
315	} else
316#endif
317	{
318		if (copy_to_user(to_fp, regs->regs.fp, sizeof(struct _xstate)))
319			return 1;
320	}
321
322	return 0;
323}
324
325#ifdef CONFIG_X86_32
326static int copy_ucontext_to_user(struct ucontext __user *uc,
327				 struct _xstate __user *fp, sigset_t *set,
328				 unsigned long sp)
329{
330	int err = 0;
331
332	err |= __save_altstack(&uc->uc_stack, sp);
333	err |= copy_sc_to_user(&uc->uc_mcontext, fp, &current->thread.regs, 0);
334	err |= copy_to_user(&uc->uc_sigmask, set, sizeof(*set));
335	return err;
336}
337
338struct sigframe
339{
340	char __user *pretcode;
341	int sig;
342	struct sigcontext sc;
343	struct _xstate fpstate;
344	unsigned long extramask[_NSIG_WORDS-1];
345	char retcode[8];
346};
347
348struct rt_sigframe
349{
350	char __user *pretcode;
351	int sig;
352	struct siginfo __user *pinfo;
353	void __user *puc;
354	struct siginfo info;
355	struct ucontext uc;
356	struct _xstate fpstate;
357	char retcode[8];
358};
359
360int setup_signal_stack_sc(unsigned long stack_top, struct ksignal *ksig,
361			  struct pt_regs *regs, sigset_t *mask)
362{
363	struct sigframe __user *frame;
364	void __user *restorer;
365	int err = 0, sig = ksig->sig;
366
367	/* This is the same calculation as i386 - ((sp + 4) & 15) == 0 */
368	stack_top = ((stack_top + 4) & -16UL) - 4;
369	frame = (struct sigframe __user *) stack_top - 1;
370	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
371		return 1;
372
373	restorer = frame->retcode;
374	if (ksig->ka.sa.sa_flags & SA_RESTORER)
375		restorer = ksig->ka.sa.sa_restorer;
376
377	err |= __put_user(restorer, &frame->pretcode);
378	err |= __put_user(sig, &frame->sig);
379	err |= copy_sc_to_user(&frame->sc, &frame->fpstate, regs, mask->sig[0]);
380	if (_NSIG_WORDS > 1)
381		err |= __copy_to_user(&frame->extramask, &mask->sig[1],
382				      sizeof(frame->extramask));
383
384	/*
385	 * This is popl %eax ; movl $,%eax ; int $0x80
386	 *
387	 * WE DO NOT USE IT ANY MORE! It's only left here for historical
388	 * reasons and because gdb uses it as a signature to notice
389	 * signal handler stack frames.
390	 */
391	err |= __put_user(0xb858, (short __user *)(frame->retcode+0));
392	err |= __put_user(__NR_sigreturn, (int __user *)(frame->retcode+2));
393	err |= __put_user(0x80cd, (short __user *)(frame->retcode+6));
394
395	if (err)
396		return err;
397
398	PT_REGS_SP(regs) = (unsigned long) frame;
399	PT_REGS_IP(regs) = (unsigned long) ksig->ka.sa.sa_handler;
400	PT_REGS_AX(regs) = (unsigned long) sig;
401	PT_REGS_DX(regs) = (unsigned long) 0;
402	PT_REGS_CX(regs) = (unsigned long) 0;
403	return 0;
404}
405
406int setup_signal_stack_si(unsigned long stack_top, struct ksignal *ksig,
407			  struct pt_regs *regs, sigset_t *mask)
408{
409	struct rt_sigframe __user *frame;
410	void __user *restorer;
411	int err = 0, sig = ksig->sig;
412
413	stack_top &= -8UL;
414	frame = (struct rt_sigframe __user *) stack_top - 1;
415	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
416		return 1;
417
418	restorer = frame->retcode;
419	if (ksig->ka.sa.sa_flags & SA_RESTORER)
420		restorer = ksig->ka.sa.sa_restorer;
421
422	err |= __put_user(restorer, &frame->pretcode);
423	err |= __put_user(sig, &frame->sig);
424	err |= __put_user(&frame->info, &frame->pinfo);
425	err |= __put_user(&frame->uc, &frame->puc);
426	err |= copy_siginfo_to_user(&frame->info, &ksig->info);
427	err |= copy_ucontext_to_user(&frame->uc, &frame->fpstate, mask,
428					PT_REGS_SP(regs));
429
430	/*
431	 * This is movl $,%eax ; int $0x80
432	 *
433	 * WE DO NOT USE IT ANY MORE! It's only left here for historical
434	 * reasons and because gdb uses it as a signature to notice
435	 * signal handler stack frames.
436	 */
437	err |= __put_user(0xb8, (char __user *)(frame->retcode+0));
438	err |= __put_user(__NR_rt_sigreturn, (int __user *)(frame->retcode+1));
439	err |= __put_user(0x80cd, (short __user *)(frame->retcode+5));
440
441	if (err)
442		return err;
443
444	PT_REGS_SP(regs) = (unsigned long) frame;
445	PT_REGS_IP(regs) = (unsigned long) ksig->ka.sa.sa_handler;
446	PT_REGS_AX(regs) = (unsigned long) sig;
447	PT_REGS_DX(regs) = (unsigned long) &frame->info;
448	PT_REGS_CX(regs) = (unsigned long) &frame->uc;
449	return 0;
450}
451
452long sys_sigreturn(void)
453{
454	unsigned long sp = PT_REGS_SP(&current->thread.regs);
455	struct sigframe __user *frame = (struct sigframe __user *)(sp - 8);
456	sigset_t set;
457	struct sigcontext __user *sc = &frame->sc;
458	int sig_size = (_NSIG_WORDS - 1) * sizeof(unsigned long);
459
460	if (copy_from_user(&set.sig[0], &sc->oldmask, sizeof(set.sig[0])) ||
461	    copy_from_user(&set.sig[1], frame->extramask, sig_size))
462		goto segfault;
463
464	set_current_blocked(&set);
465
466	if (copy_sc_from_user(&current->thread.regs, sc))
467		goto segfault;
468
469	/* Avoid ERESTART handling */
470	PT_REGS_SYSCALL_NR(&current->thread.regs) = -1;
471	return PT_REGS_SYSCALL_RET(&current->thread.regs);
472
473 segfault:
474	force_sig(SIGSEGV, current);
475	return 0;
476}
477
478#else
479
480struct rt_sigframe
481{
482	char __user *pretcode;
483	struct ucontext uc;
484	struct siginfo info;
485	struct _xstate fpstate;
486};
487
488int setup_signal_stack_si(unsigned long stack_top, struct ksignal *ksig,
489			  struct pt_regs *regs, sigset_t *set)
490{
491	struct rt_sigframe __user *frame;
492	int err = 0, sig = ksig->sig;
493	unsigned long fp_to;
494
495	frame = (struct rt_sigframe __user *)
496		round_down(stack_top - sizeof(struct rt_sigframe), 16);
497	/* Subtract 128 for a red zone and 8 for proper alignment */
498	frame = (struct rt_sigframe __user *) ((unsigned long) frame - 128 - 8);
499
500	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
501		goto out;
502
503	if (ksig->ka.sa.sa_flags & SA_SIGINFO) {
504		err |= copy_siginfo_to_user(&frame->info, &ksig->info);
505		if (err)
506			goto out;
507	}
508
509	/* Create the ucontext.  */
510	err |= __put_user(0, &frame->uc.uc_flags);
511	err |= __put_user(0, &frame->uc.uc_link);
512	err |= __save_altstack(&frame->uc.uc_stack, PT_REGS_SP(regs));
513	err |= copy_sc_to_user(&frame->uc.uc_mcontext, &frame->fpstate, regs,
514			       set->sig[0]);
515
516	fp_to = (unsigned long)&frame->fpstate;
517
518	err |= __put_user(fp_to, &frame->uc.uc_mcontext.fpstate);
519	if (sizeof(*set) == 16) {
520		err |= __put_user(set->sig[0], &frame->uc.uc_sigmask.sig[0]);
521		err |= __put_user(set->sig[1], &frame->uc.uc_sigmask.sig[1]);
522	}
523	else
524		err |= __copy_to_user(&frame->uc.uc_sigmask, set,
525				      sizeof(*set));
526
527	/*
528	 * Set up to return from userspace.  If provided, use a stub
529	 * already in userspace.
530	 */
531	/* x86-64 should always use SA_RESTORER. */
532	if (ksig->ka.sa.sa_flags & SA_RESTORER)
533		err |= __put_user((void *)ksig->ka.sa.sa_restorer,
534				  &frame->pretcode);
535	else
536		/* could use a vstub here */
537		return err;
538
539	if (err)
540		return err;
541
542	PT_REGS_SP(regs) = (unsigned long) frame;
543	PT_REGS_DI(regs) = sig;
544	/* In case the signal handler was declared without prototypes */
545	PT_REGS_AX(regs) = 0;
546
547	/*
548	 * This also works for non SA_SIGINFO handlers because they expect the
549	 * next argument after the signal number on the stack.
550	 */
551	PT_REGS_SI(regs) = (unsigned long) &frame->info;
552	PT_REGS_DX(regs) = (unsigned long) &frame->uc;
553	PT_REGS_IP(regs) = (unsigned long) ksig->ka.sa.sa_handler;
554 out:
555	return err;
556}
557#endif
558
559long sys_rt_sigreturn(void)
560{
561	unsigned long sp = PT_REGS_SP(&current->thread.regs);
562	struct rt_sigframe __user *frame =
563		(struct rt_sigframe __user *)(sp - sizeof(long));
564	struct ucontext __user *uc = &frame->uc;
565	sigset_t set;
566
567	if (copy_from_user(&set, &uc->uc_sigmask, sizeof(set)))
568		goto segfault;
569
570	set_current_blocked(&set);
571
572	if (copy_sc_from_user(&current->thread.regs, &uc->uc_mcontext))
573		goto segfault;
574
575	/* Avoid ERESTART handling */
576	PT_REGS_SYSCALL_NR(&current->thread.regs) = -1;
577	return PT_REGS_SYSCALL_RET(&current->thread.regs);
578
579 segfault:
580	force_sig(SIGSEGV, current);
581	return 0;
582}