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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 <linux/syscalls.h>
12#include <asm/unistd.h>
13#include <linux/uaccess.h>
14#include <asm/ucontext.h>
15#include <frame_kern.h>
16#include <registers.h>
17#include <skas.h>
18
19#include <linux/regset.h>
20#include <asm/sigframe.h>
21
22#ifdef CONFIG_X86_32
23struct _xstate_64 {
24 struct _fpstate_64 fpstate;
25 struct _header xstate_hdr;
26 struct _ymmh_state ymmh;
27 /* New processor state extensions go here: */
28};
29#else
30#define _xstate_64 _xstate
31#endif
32
33static int copy_sc_from_user(struct pt_regs *regs,
34 struct sigcontext __user *from)
35{
36 struct _xstate_64 __user *from_fp64;
37 struct sigcontext sc;
38 int err;
39
40 /* Always make any pending restarted system calls return -EINTR */
41 current->restart_block.fn = do_no_restart_syscall;
42
43 err = copy_from_user(&sc, from, sizeof(sc));
44 if (err)
45 return err;
46
47#define GETREG(regno, regname) regs->regs.gp[HOST_##regno] = sc.regname
48
49#ifdef CONFIG_X86_32
50 GETREG(GS, gs);
51 GETREG(FS, fs);
52 GETREG(ES, es);
53 GETREG(DS, ds);
54#endif
55 GETREG(DI, di);
56 GETREG(SI, si);
57 GETREG(BP, bp);
58 GETREG(SP, sp);
59 GETREG(BX, bx);
60 GETREG(DX, dx);
61 GETREG(CX, cx);
62 GETREG(AX, ax);
63 GETREG(IP, ip);
64
65#ifdef CONFIG_X86_64
66 GETREG(R8, r8);
67 GETREG(R9, r9);
68 GETREG(R10, r10);
69 GETREG(R11, r11);
70 GETREG(R12, r12);
71 GETREG(R13, r13);
72 GETREG(R14, r14);
73 GETREG(R15, r15);
74#endif
75
76 GETREG(CS, cs);
77 GETREG(EFLAGS, flags);
78#ifdef CONFIG_X86_32
79 GETREG(SS, ss);
80#endif
81
82#undef GETREG
83
84#ifdef CONFIG_X86_32
85 from_fp64 = ((void __user *)sc.fpstate) +
86 offsetof(struct _fpstate_32, _fxsr_env);
87#else
88 from_fp64 = (void __user *)sc.fpstate;
89#endif
90
91 err = copy_from_user(regs->regs.fp, from_fp64, host_fp_size);
92 if (err)
93 return 1;
94
95#ifdef CONFIG_X86_32
96 /* Data is duplicated and this copy is the important one */
97 err = copy_regset_from_user(current,
98 task_user_regset_view(current),
99 REGSET_FP_LEGACY, 0,
100 sizeof(struct user_i387_struct),
101 (void __user *)sc.fpstate);
102 if (err < 0)
103 return err;
104#endif
105
106 return 0;
107}
108
109static int copy_sc_to_user(struct sigcontext __user *to,
110 struct _xstate __user *to_fp, struct pt_regs *regs,
111 unsigned long mask)
112{
113 struct _xstate_64 __user *to_fp64;
114 struct sigcontext sc;
115 struct faultinfo * fi = ¤t->thread.arch.faultinfo;
116 int err;
117 memset(&sc, 0, sizeof(struct sigcontext));
118
119#define PUTREG(regno, regname) sc.regname = regs->regs.gp[HOST_##regno]
120
121#ifdef CONFIG_X86_32
122 PUTREG(GS, gs);
123 PUTREG(FS, fs);
124 PUTREG(ES, es);
125 PUTREG(DS, ds);
126#endif
127 PUTREG(DI, di);
128 PUTREG(SI, si);
129 PUTREG(BP, bp);
130 PUTREG(SP, sp);
131 PUTREG(BX, bx);
132 PUTREG(DX, dx);
133 PUTREG(CX, cx);
134 PUTREG(AX, ax);
135#ifdef CONFIG_X86_64
136 PUTREG(R8, r8);
137 PUTREG(R9, r9);
138 PUTREG(R10, r10);
139 PUTREG(R11, r11);
140 PUTREG(R12, r12);
141 PUTREG(R13, r13);
142 PUTREG(R14, r14);
143 PUTREG(R15, r15);
144#endif
145
146 sc.cr2 = fi->cr2;
147 sc.err = fi->error_code;
148 sc.trapno = fi->trap_no;
149 PUTREG(IP, ip);
150 PUTREG(CS, cs);
151 PUTREG(EFLAGS, flags);
152#ifdef CONFIG_X86_32
153 PUTREG(SP, sp_at_signal);
154 PUTREG(SS, ss);
155#endif
156#undef PUTREG
157 sc.oldmask = mask;
158 sc.fpstate = (unsigned long)to_fp;
159
160 err = copy_to_user(to, &sc, sizeof(struct sigcontext));
161 if (err)
162 return 1;
163
164#ifdef CONFIG_X86_32
165 err = copy_regset_to_user(current,
166 task_user_regset_view(current),
167 REGSET_FP_LEGACY, 0,
168 sizeof(struct _fpstate_32), to_fp);
169 if (err < 0)
170 return err;
171
172 __put_user(X86_FXSR_MAGIC, &to_fp->fpstate.magic);
173
174 BUILD_BUG_ON(offsetof(struct _xstate, xstate_hdr) !=
175 offsetof(struct _xstate_64, xstate_hdr) +
176 offsetof(struct _fpstate_32, _fxsr_env));
177 to_fp64 = (void __user *)to_fp +
178 offsetof(struct _fpstate_32, _fxsr_env);
179#else
180 to_fp64 = to_fp;
181#endif /* CONFIG_X86_32 */
182
183 if (copy_to_user(to_fp64, regs->regs.fp, host_fp_size))
184 return 1;
185
186 /*
187 * Put magic/size values for userspace. We do not bother to verify them
188 * later on, however, userspace needs them should it try to read the
189 * XSTATE data. And ptrace does not fill in these parts.
190 *
191 * Skip this if we do not have an XSTATE frame.
192 */
193 if (host_fp_size <= sizeof(to_fp64->fpstate))
194 return 0;
195
196 BUILD_BUG_ON(sizeof(int) != FP_XSTATE_MAGIC2_SIZE);
197#ifdef CONFIG_X86_32
198 __put_user(offsetof(struct _fpstate_32, _fxsr_env) +
199 host_fp_size + FP_XSTATE_MAGIC2_SIZE,
200 &to_fp64->fpstate.sw_reserved.extended_size);
201#else
202 __put_user(host_fp_size + FP_XSTATE_MAGIC2_SIZE,
203 &to_fp64->fpstate.sw_reserved.extended_size);
204#endif
205 __put_user(host_fp_size, &to_fp64->fpstate.sw_reserved.xstate_size);
206
207 __put_user(FP_XSTATE_MAGIC1, &to_fp64->fpstate.sw_reserved.magic1);
208 __put_user(FP_XSTATE_MAGIC2,
209 (int __user *)((void __user *)to_fp64 + host_fp_size));
210
211 return 0;
212}
213
214#ifdef CONFIG_X86_32
215static int copy_ucontext_to_user(struct ucontext __user *uc,
216 struct _xstate __user *fp, sigset_t *set,
217 unsigned long sp)
218{
219 int err = 0;
220
221 err |= __save_altstack(&uc->uc_stack, sp);
222 err |= copy_sc_to_user(&uc->uc_mcontext, fp, ¤t->thread.regs, 0);
223 err |= copy_to_user(&uc->uc_sigmask, set, sizeof(*set));
224 return err;
225}
226
227int setup_signal_stack_sc(unsigned long stack_top, struct ksignal *ksig,
228 struct pt_regs *regs, sigset_t *mask)
229{
230 size_t math_size = offsetof(struct _fpstate_32, _fxsr_env) +
231 host_fp_size + FP_XSTATE_MAGIC2_SIZE;
232 struct sigframe __user *frame;
233 void __user *restorer;
234 int err = 0, sig = ksig->sig;
235 unsigned long fp_to;
236
237 /* This is the same calculation as i386 - ((sp + 4) & 15) == 0 */
238 stack_top = ((stack_top + 4) & -16UL) - 4;
239 frame = (struct sigframe __user *) stack_top - 1;
240 if (!access_ok(frame, sizeof(*frame)))
241 return 1;
242
243 /* Add required space for math frame */
244 frame = (struct sigframe __user *)((unsigned long)frame - math_size);
245
246 restorer = frame->retcode;
247 if (ksig->ka.sa.sa_flags & SA_RESTORER)
248 restorer = ksig->ka.sa.sa_restorer;
249
250 err |= __put_user(restorer, (void __user * __user *)&frame->pretcode);
251 err |= __put_user(sig, &frame->sig);
252
253 fp_to = (unsigned long)frame + sizeof(*frame);
254
255 err |= copy_sc_to_user(&frame->sc,
256 (struct _xstate __user *)fp_to,
257 regs, mask->sig[0]);
258 if (_NSIG_WORDS > 1)
259 err |= __copy_to_user(&frame->extramask, &mask->sig[1],
260 sizeof(frame->extramask));
261
262 /*
263 * This is popl %eax ; movl $,%eax ; int $0x80
264 *
265 * WE DO NOT USE IT ANY MORE! It's only left here for historical
266 * reasons and because gdb uses it as a signature to notice
267 * signal handler stack frames.
268 */
269 err |= __put_user(0xb858, (short __user *)(frame->retcode+0));
270 err |= __put_user(__NR_sigreturn, (int __user *)(frame->retcode+2));
271 err |= __put_user(0x80cd, (short __user *)(frame->retcode+6));
272
273 if (err)
274 return err;
275
276 PT_REGS_SP(regs) = (unsigned long) frame;
277 PT_REGS_IP(regs) = (unsigned long) ksig->ka.sa.sa_handler;
278 PT_REGS_AX(regs) = (unsigned long) sig;
279 PT_REGS_DX(regs) = (unsigned long) 0;
280 PT_REGS_CX(regs) = (unsigned long) 0;
281 return 0;
282}
283
284int setup_signal_stack_si(unsigned long stack_top, struct ksignal *ksig,
285 struct pt_regs *regs, sigset_t *mask)
286{
287 size_t math_size = offsetof(struct _fpstate_32, _fxsr_env) +
288 host_fp_size + FP_XSTATE_MAGIC2_SIZE;
289 struct rt_sigframe __user *frame;
290 void __user *restorer;
291 int err = 0, sig = ksig->sig;
292 unsigned long fp_to;
293
294 stack_top &= -8UL;
295 frame = (struct rt_sigframe __user *) stack_top - 1;
296 if (!access_ok(frame, sizeof(*frame)))
297 return 1;
298
299 /* Add required space for math frame */
300 frame = (struct rt_sigframe __user *)((unsigned long)frame - math_size);
301
302 restorer = frame->retcode;
303 if (ksig->ka.sa.sa_flags & SA_RESTORER)
304 restorer = ksig->ka.sa.sa_restorer;
305
306 err |= __put_user(restorer, (void __user * __user *)&frame->pretcode);
307 err |= __put_user(sig, &frame->sig);
308 err |= __put_user(&frame->info, (void __user * __user *)&frame->pinfo);
309 err |= __put_user(&frame->uc, (void __user * __user *)&frame->puc);
310 err |= copy_siginfo_to_user(&frame->info, &ksig->info);
311
312 fp_to = (unsigned long)frame + sizeof(*frame);
313
314 err |= copy_ucontext_to_user(&frame->uc, (struct _xstate __user *)fp_to,
315 mask, PT_REGS_SP(regs));
316
317 /*
318 * This is movl $,%eax ; int $0x80
319 *
320 * WE DO NOT USE IT ANY MORE! It's only left here for historical
321 * reasons and because gdb uses it as a signature to notice
322 * signal handler stack frames.
323 */
324 err |= __put_user(0xb8, (char __user *)(frame->retcode+0));
325 err |= __put_user(__NR_rt_sigreturn, (int __user *)(frame->retcode+1));
326 err |= __put_user(0x80cd, (short __user *)(frame->retcode+5));
327
328 if (err)
329 return err;
330
331 PT_REGS_SP(regs) = (unsigned long) frame;
332 PT_REGS_IP(regs) = (unsigned long) ksig->ka.sa.sa_handler;
333 PT_REGS_AX(regs) = (unsigned long) sig;
334 PT_REGS_DX(regs) = (unsigned long) &frame->info;
335 PT_REGS_CX(regs) = (unsigned long) &frame->uc;
336 return 0;
337}
338
339SYSCALL_DEFINE0(sigreturn)
340{
341 unsigned long sp = PT_REGS_SP(¤t->thread.regs);
342 struct sigframe __user *frame = (struct sigframe __user *)(sp - 8);
343 sigset_t set;
344 struct sigcontext __user *sc = &frame->sc;
345 int sig_size = (_NSIG_WORDS - 1) * sizeof(unsigned long);
346
347 if (copy_from_user(&set.sig[0], &sc->oldmask, sizeof(set.sig[0])) ||
348 copy_from_user(&set.sig[1], frame->extramask, sig_size))
349 goto segfault;
350
351 set_current_blocked(&set);
352
353 if (copy_sc_from_user(¤t->thread.regs, sc))
354 goto segfault;
355
356 /* Avoid ERESTART handling */
357 PT_REGS_SYSCALL_NR(¤t->thread.regs) = -1;
358 return PT_REGS_SYSCALL_RET(¤t->thread.regs);
359
360 segfault:
361 force_sig(SIGSEGV);
362 return 0;
363}
364
365#else
366
367int setup_signal_stack_si(unsigned long stack_top, struct ksignal *ksig,
368 struct pt_regs *regs, sigset_t *set)
369{
370 unsigned long math_size = host_fp_size + FP_XSTATE_MAGIC2_SIZE;
371 struct rt_sigframe __user *frame;
372 int err = 0, sig = ksig->sig;
373 unsigned long fp_to;
374
375 frame = (void __user *)stack_top - sizeof(struct rt_sigframe);
376
377 /* Add required space for math frame */
378 frame = (void __user *)((unsigned long)frame - math_size);
379
380 /* ABI requires 16 byte boundary alignment */
381 frame = (void __user *)round_down((unsigned long)frame, 16);
382
383 /* Subtract 128 for a red zone and 8 for proper alignment */
384 frame = (struct rt_sigframe __user *) ((unsigned long) frame - 128 - 8);
385
386 if (!access_ok(frame, sizeof(*frame) + math_size))
387 goto out;
388
389 if (ksig->ka.sa.sa_flags & SA_SIGINFO) {
390 err |= copy_siginfo_to_user(&frame->info, &ksig->info);
391 if (err)
392 goto out;
393 }
394
395 /* Create the ucontext. */
396 err |= __put_user(0, &frame->uc.uc_flags);
397 err |= __put_user(NULL, &frame->uc.uc_link);
398 err |= __save_altstack(&frame->uc.uc_stack, PT_REGS_SP(regs));
399
400 fp_to = (unsigned long)frame + sizeof(*frame);
401
402 err |= copy_sc_to_user(&frame->uc.uc_mcontext,
403 (struct _xstate __user *)fp_to,
404 regs, set->sig[0]);
405
406 err |= __put_user(fp_to, &frame->uc.uc_mcontext.fpstate);
407 if (sizeof(*set) == 16) {
408 err |= __put_user(set->sig[0], &frame->uc.uc_sigmask.sig[0]);
409 err |= __put_user(set->sig[1], &frame->uc.uc_sigmask.sig[1]);
410 }
411 else
412 err |= __copy_to_user(&frame->uc.uc_sigmask, set,
413 sizeof(*set));
414
415 /*
416 * Set up to return from userspace. If provided, use a stub
417 * already in userspace.
418 */
419 /* x86-64 should always use SA_RESTORER. */
420 if (ksig->ka.sa.sa_flags & SA_RESTORER)
421 err |= __put_user((void __user *)ksig->ka.sa.sa_restorer,
422 &frame->pretcode);
423 else
424 /* could use a vstub here */
425 return err;
426
427 if (err)
428 return err;
429
430 PT_REGS_SP(regs) = (unsigned long) frame;
431 PT_REGS_DI(regs) = sig;
432 /* In case the signal handler was declared without prototypes */
433 PT_REGS_AX(regs) = 0;
434
435 /*
436 * This also works for non SA_SIGINFO handlers because they expect the
437 * next argument after the signal number on the stack.
438 */
439 PT_REGS_SI(regs) = (unsigned long) &frame->info;
440 PT_REGS_DX(regs) = (unsigned long) &frame->uc;
441 PT_REGS_IP(regs) = (unsigned long) ksig->ka.sa.sa_handler;
442 out:
443 return err;
444}
445#endif
446
447SYSCALL_DEFINE0(rt_sigreturn)
448{
449 unsigned long sp = PT_REGS_SP(¤t->thread.regs);
450 struct rt_sigframe __user *frame =
451 (struct rt_sigframe __user *)(sp - sizeof(long));
452 struct ucontext __user *uc = &frame->uc;
453 sigset_t set;
454
455 if (copy_from_user(&set, &uc->uc_sigmask, sizeof(set)))
456 goto segfault;
457
458 set_current_blocked(&set);
459
460 if (copy_sc_from_user(¤t->thread.regs, &uc->uc_mcontext))
461 goto segfault;
462
463 /* Avoid ERESTART handling */
464 PT_REGS_SYSCALL_NR(¤t->thread.regs) = -1;
465 return PT_REGS_SYSCALL_RET(¤t->thread.regs);
466
467 segfault:
468 force_sig(SIGSEGV);
469 return 0;
470}
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 <registers.h>
16#include <skas.h>
17
18#ifdef CONFIG_X86_32
19
20/*
21 * FPU tag word conversions.
22 */
23
24static inline unsigned short twd_i387_to_fxsr(unsigned short twd)
25{
26 unsigned int tmp; /* to avoid 16 bit prefixes in the code */
27
28 /* Transform each pair of bits into 01 (valid) or 00 (empty) */
29 tmp = ~twd;
30 tmp = (tmp | (tmp>>1)) & 0x5555; /* 0V0V0V0V0V0V0V0V */
31 /* and move the valid bits to the lower byte. */
32 tmp = (tmp | (tmp >> 1)) & 0x3333; /* 00VV00VV00VV00VV */
33 tmp = (tmp | (tmp >> 2)) & 0x0f0f; /* 0000VVVV0000VVVV */
34 tmp = (tmp | (tmp >> 4)) & 0x00ff; /* 00000000VVVVVVVV */
35 return tmp;
36}
37
38static inline unsigned long twd_fxsr_to_i387(struct user_fxsr_struct *fxsave)
39{
40 struct _fpxreg *st = NULL;
41 unsigned long twd = (unsigned long) fxsave->twd;
42 unsigned long tag;
43 unsigned long ret = 0xffff0000;
44 int i;
45
46#define FPREG_ADDR(f, n) ((char *)&(f)->st_space + (n) * 16)
47
48 for (i = 0; i < 8; i++) {
49 if (twd & 0x1) {
50 st = (struct _fpxreg *) FPREG_ADDR(fxsave, i);
51
52 switch (st->exponent & 0x7fff) {
53 case 0x7fff:
54 tag = 2; /* Special */
55 break;
56 case 0x0000:
57 if ( !st->significand[0] &&
58 !st->significand[1] &&
59 !st->significand[2] &&
60 !st->significand[3] ) {
61 tag = 1; /* Zero */
62 } else {
63 tag = 2; /* Special */
64 }
65 break;
66 default:
67 if (st->significand[3] & 0x8000) {
68 tag = 0; /* Valid */
69 } else {
70 tag = 2; /* Special */
71 }
72 break;
73 }
74 } else {
75 tag = 3; /* Empty */
76 }
77 ret |= (tag << (2 * i));
78 twd = twd >> 1;
79 }
80 return ret;
81}
82
83static int convert_fxsr_to_user(struct _fpstate __user *buf,
84 struct user_fxsr_struct *fxsave)
85{
86 unsigned long env[7];
87 struct _fpreg __user *to;
88 struct _fpxreg *from;
89 int i;
90
91 env[0] = (unsigned long)fxsave->cwd | 0xffff0000ul;
92 env[1] = (unsigned long)fxsave->swd | 0xffff0000ul;
93 env[2] = twd_fxsr_to_i387(fxsave);
94 env[3] = fxsave->fip;
95 env[4] = fxsave->fcs | ((unsigned long)fxsave->fop << 16);
96 env[5] = fxsave->foo;
97 env[6] = fxsave->fos;
98
99 if (__copy_to_user(buf, env, 7 * sizeof(unsigned long)))
100 return 1;
101
102 to = &buf->_st[0];
103 from = (struct _fpxreg *) &fxsave->st_space[0];
104 for (i = 0; i < 8; i++, to++, from++) {
105 unsigned long __user *t = (unsigned long __user *)to;
106 unsigned long *f = (unsigned long *)from;
107
108 if (__put_user(*f, t) ||
109 __put_user(*(f + 1), t + 1) ||
110 __put_user(from->exponent, &to->exponent))
111 return 1;
112 }
113 return 0;
114}
115
116static int convert_fxsr_from_user(struct user_fxsr_struct *fxsave,
117 struct _fpstate __user *buf)
118{
119 unsigned long env[7];
120 struct _fpxreg *to;
121 struct _fpreg __user *from;
122 int i;
123
124 if (copy_from_user( env, buf, 7 * sizeof(long)))
125 return 1;
126
127 fxsave->cwd = (unsigned short)(env[0] & 0xffff);
128 fxsave->swd = (unsigned short)(env[1] & 0xffff);
129 fxsave->twd = twd_i387_to_fxsr((unsigned short)(env[2] & 0xffff));
130 fxsave->fip = env[3];
131 fxsave->fop = (unsigned short)((env[4] & 0xffff0000ul) >> 16);
132 fxsave->fcs = (env[4] & 0xffff);
133 fxsave->foo = env[5];
134 fxsave->fos = env[6];
135
136 to = (struct _fpxreg *) &fxsave->st_space[0];
137 from = &buf->_st[0];
138 for (i = 0; i < 8; i++, to++, from++) {
139 unsigned long *t = (unsigned long *)to;
140 unsigned long __user *f = (unsigned long __user *)from;
141
142 if (__get_user(*t, f) ||
143 __get_user(*(t + 1), f + 1) ||
144 __get_user(to->exponent, &from->exponent))
145 return 1;
146 }
147 return 0;
148}
149
150extern int have_fpx_regs;
151
152#endif
153
154static int copy_sc_from_user(struct pt_regs *regs,
155 struct sigcontext __user *from)
156{
157 struct sigcontext sc;
158 int err, pid;
159
160 /* Always make any pending restarted system calls return -EINTR */
161 current->restart_block.fn = do_no_restart_syscall;
162
163 err = copy_from_user(&sc, from, sizeof(sc));
164 if (err)
165 return err;
166
167#define GETREG(regno, regname) regs->regs.gp[HOST_##regno] = sc.regname
168
169#ifdef CONFIG_X86_32
170 GETREG(GS, gs);
171 GETREG(FS, fs);
172 GETREG(ES, es);
173 GETREG(DS, ds);
174#endif
175 GETREG(DI, di);
176 GETREG(SI, si);
177 GETREG(BP, bp);
178 GETREG(SP, sp);
179 GETREG(BX, bx);
180 GETREG(DX, dx);
181 GETREG(CX, cx);
182 GETREG(AX, ax);
183 GETREG(IP, ip);
184
185#ifdef CONFIG_X86_64
186 GETREG(R8, r8);
187 GETREG(R9, r9);
188 GETREG(R10, r10);
189 GETREG(R11, r11);
190 GETREG(R12, r12);
191 GETREG(R13, r13);
192 GETREG(R14, r14);
193 GETREG(R15, r15);
194#endif
195
196 GETREG(CS, cs);
197 GETREG(EFLAGS, flags);
198#ifdef CONFIG_X86_32
199 GETREG(SS, ss);
200#endif
201
202#undef GETREG
203
204 pid = userspace_pid[current_thread_info()->cpu];
205#ifdef CONFIG_X86_32
206 if (have_fpx_regs) {
207 struct user_fxsr_struct fpx;
208
209 err = copy_from_user(&fpx,
210 &((struct _fpstate __user *)sc.fpstate)->_fxsr_env[0],
211 sizeof(struct user_fxsr_struct));
212 if (err)
213 return 1;
214
215 err = convert_fxsr_from_user(&fpx, (void *)sc.fpstate);
216 if (err)
217 return 1;
218
219 err = restore_fpx_registers(pid, (unsigned long *) &fpx);
220 if (err < 0) {
221 printk(KERN_ERR "copy_sc_from_user - "
222 "restore_fpx_registers failed, errno = %d\n",
223 -err);
224 return 1;
225 }
226 } else
227#endif
228 {
229 err = copy_from_user(regs->regs.fp, (void *)sc.fpstate,
230 sizeof(struct _xstate));
231 if (err)
232 return 1;
233 }
234 return 0;
235}
236
237static int copy_sc_to_user(struct sigcontext __user *to,
238 struct _xstate __user *to_fp, struct pt_regs *regs,
239 unsigned long mask)
240{
241 struct sigcontext sc;
242 struct faultinfo * fi = ¤t->thread.arch.faultinfo;
243 int err, pid;
244 memset(&sc, 0, sizeof(struct sigcontext));
245
246#define PUTREG(regno, regname) sc.regname = regs->regs.gp[HOST_##regno]
247
248#ifdef CONFIG_X86_32
249 PUTREG(GS, gs);
250 PUTREG(FS, fs);
251 PUTREG(ES, es);
252 PUTREG(DS, ds);
253#endif
254 PUTREG(DI, di);
255 PUTREG(SI, si);
256 PUTREG(BP, bp);
257 PUTREG(SP, sp);
258 PUTREG(BX, bx);
259 PUTREG(DX, dx);
260 PUTREG(CX, cx);
261 PUTREG(AX, ax);
262#ifdef CONFIG_X86_64
263 PUTREG(R8, r8);
264 PUTREG(R9, r9);
265 PUTREG(R10, r10);
266 PUTREG(R11, r11);
267 PUTREG(R12, r12);
268 PUTREG(R13, r13);
269 PUTREG(R14, r14);
270 PUTREG(R15, r15);
271#endif
272
273 sc.cr2 = fi->cr2;
274 sc.err = fi->error_code;
275 sc.trapno = fi->trap_no;
276 PUTREG(IP, ip);
277 PUTREG(CS, cs);
278 PUTREG(EFLAGS, flags);
279#ifdef CONFIG_X86_32
280 PUTREG(SP, sp_at_signal);
281 PUTREG(SS, ss);
282#endif
283#undef PUTREG
284 sc.oldmask = mask;
285 sc.fpstate = (unsigned long)to_fp;
286
287 err = copy_to_user(to, &sc, sizeof(struct sigcontext));
288 if (err)
289 return 1;
290
291 pid = userspace_pid[current_thread_info()->cpu];
292
293#ifdef CONFIG_X86_32
294 if (have_fpx_regs) {
295 struct user_fxsr_struct fpx;
296
297 err = save_fpx_registers(pid, (unsigned long *) &fpx);
298 if (err < 0){
299 printk(KERN_ERR "copy_sc_to_user - save_fpx_registers "
300 "failed, errno = %d\n", err);
301 return 1;
302 }
303
304 err = convert_fxsr_to_user(&to_fp->fpstate, &fpx);
305 if (err)
306 return 1;
307
308 err |= __put_user(fpx.swd, &to_fp->fpstate.status);
309 err |= __put_user(X86_FXSR_MAGIC, &to_fp->fpstate.magic);
310 if (err)
311 return 1;
312
313 if (copy_to_user(&to_fp->fpstate._fxsr_env[0], &fpx,
314 sizeof(struct user_fxsr_struct)))
315 return 1;
316 } else
317#endif
318 {
319 if (copy_to_user(to_fp, regs->regs.fp, sizeof(struct _xstate)))
320 return 1;
321 }
322
323 return 0;
324}
325
326#ifdef CONFIG_X86_32
327static int copy_ucontext_to_user(struct ucontext __user *uc,
328 struct _xstate __user *fp, sigset_t *set,
329 unsigned long sp)
330{
331 int err = 0;
332
333 err |= __save_altstack(&uc->uc_stack, sp);
334 err |= copy_sc_to_user(&uc->uc_mcontext, fp, ¤t->thread.regs, 0);
335 err |= copy_to_user(&uc->uc_sigmask, set, sizeof(*set));
336 return err;
337}
338
339struct sigframe
340{
341 char __user *pretcode;
342 int sig;
343 struct sigcontext sc;
344 struct _xstate fpstate;
345 unsigned long extramask[_NSIG_WORDS-1];
346 char retcode[8];
347};
348
349struct rt_sigframe
350{
351 char __user *pretcode;
352 int sig;
353 struct siginfo __user *pinfo;
354 void __user *puc;
355 struct siginfo info;
356 struct ucontext uc;
357 struct _xstate fpstate;
358 char retcode[8];
359};
360
361int setup_signal_stack_sc(unsigned long stack_top, struct ksignal *ksig,
362 struct pt_regs *regs, sigset_t *mask)
363{
364 struct sigframe __user *frame;
365 void __user *restorer;
366 int err = 0, sig = ksig->sig;
367
368 /* This is the same calculation as i386 - ((sp + 4) & 15) == 0 */
369 stack_top = ((stack_top + 4) & -16UL) - 4;
370 frame = (struct sigframe __user *) stack_top - 1;
371 if (!access_ok(frame, sizeof(*frame)))
372 return 1;
373
374 restorer = frame->retcode;
375 if (ksig->ka.sa.sa_flags & SA_RESTORER)
376 restorer = ksig->ka.sa.sa_restorer;
377
378 err |= __put_user(restorer, &frame->pretcode);
379 err |= __put_user(sig, &frame->sig);
380 err |= copy_sc_to_user(&frame->sc, &frame->fpstate, regs, mask->sig[0]);
381 if (_NSIG_WORDS > 1)
382 err |= __copy_to_user(&frame->extramask, &mask->sig[1],
383 sizeof(frame->extramask));
384
385 /*
386 * This is popl %eax ; movl $,%eax ; int $0x80
387 *
388 * WE DO NOT USE IT ANY MORE! It's only left here for historical
389 * reasons and because gdb uses it as a signature to notice
390 * signal handler stack frames.
391 */
392 err |= __put_user(0xb858, (short __user *)(frame->retcode+0));
393 err |= __put_user(__NR_sigreturn, (int __user *)(frame->retcode+2));
394 err |= __put_user(0x80cd, (short __user *)(frame->retcode+6));
395
396 if (err)
397 return err;
398
399 PT_REGS_SP(regs) = (unsigned long) frame;
400 PT_REGS_IP(regs) = (unsigned long) ksig->ka.sa.sa_handler;
401 PT_REGS_AX(regs) = (unsigned long) sig;
402 PT_REGS_DX(regs) = (unsigned long) 0;
403 PT_REGS_CX(regs) = (unsigned long) 0;
404 return 0;
405}
406
407int setup_signal_stack_si(unsigned long stack_top, struct ksignal *ksig,
408 struct pt_regs *regs, sigset_t *mask)
409{
410 struct rt_sigframe __user *frame;
411 void __user *restorer;
412 int err = 0, sig = ksig->sig;
413
414 stack_top &= -8UL;
415 frame = (struct rt_sigframe __user *) stack_top - 1;
416 if (!access_ok(frame, sizeof(*frame)))
417 return 1;
418
419 restorer = frame->retcode;
420 if (ksig->ka.sa.sa_flags & SA_RESTORER)
421 restorer = ksig->ka.sa.sa_restorer;
422
423 err |= __put_user(restorer, &frame->pretcode);
424 err |= __put_user(sig, &frame->sig);
425 err |= __put_user(&frame->info, &frame->pinfo);
426 err |= __put_user(&frame->uc, &frame->puc);
427 err |= copy_siginfo_to_user(&frame->info, &ksig->info);
428 err |= copy_ucontext_to_user(&frame->uc, &frame->fpstate, mask,
429 PT_REGS_SP(regs));
430
431 /*
432 * This is movl $,%eax ; int $0x80
433 *
434 * WE DO NOT USE IT ANY MORE! It's only left here for historical
435 * reasons and because gdb uses it as a signature to notice
436 * signal handler stack frames.
437 */
438 err |= __put_user(0xb8, (char __user *)(frame->retcode+0));
439 err |= __put_user(__NR_rt_sigreturn, (int __user *)(frame->retcode+1));
440 err |= __put_user(0x80cd, (short __user *)(frame->retcode+5));
441
442 if (err)
443 return err;
444
445 PT_REGS_SP(regs) = (unsigned long) frame;
446 PT_REGS_IP(regs) = (unsigned long) ksig->ka.sa.sa_handler;
447 PT_REGS_AX(regs) = (unsigned long) sig;
448 PT_REGS_DX(regs) = (unsigned long) &frame->info;
449 PT_REGS_CX(regs) = (unsigned long) &frame->uc;
450 return 0;
451}
452
453long sys_sigreturn(void)
454{
455 unsigned long sp = PT_REGS_SP(¤t->thread.regs);
456 struct sigframe __user *frame = (struct sigframe __user *)(sp - 8);
457 sigset_t set;
458 struct sigcontext __user *sc = &frame->sc;
459 int sig_size = (_NSIG_WORDS - 1) * sizeof(unsigned long);
460
461 if (copy_from_user(&set.sig[0], &sc->oldmask, sizeof(set.sig[0])) ||
462 copy_from_user(&set.sig[1], frame->extramask, sig_size))
463 goto segfault;
464
465 set_current_blocked(&set);
466
467 if (copy_sc_from_user(¤t->thread.regs, sc))
468 goto segfault;
469
470 /* Avoid ERESTART handling */
471 PT_REGS_SYSCALL_NR(¤t->thread.regs) = -1;
472 return PT_REGS_SYSCALL_RET(¤t->thread.regs);
473
474 segfault:
475 force_sig(SIGSEGV);
476 return 0;
477}
478
479#else
480
481struct rt_sigframe
482{
483 char __user *pretcode;
484 struct ucontext uc;
485 struct siginfo info;
486 struct _xstate fpstate;
487};
488
489int setup_signal_stack_si(unsigned long stack_top, struct ksignal *ksig,
490 struct pt_regs *regs, sigset_t *set)
491{
492 struct rt_sigframe __user *frame;
493 int err = 0, sig = ksig->sig;
494 unsigned long fp_to;
495
496 frame = (struct rt_sigframe __user *)
497 round_down(stack_top - sizeof(struct rt_sigframe), 16);
498 /* Subtract 128 for a red zone and 8 for proper alignment */
499 frame = (struct rt_sigframe __user *) ((unsigned long) frame - 128 - 8);
500
501 if (!access_ok(frame, sizeof(*frame)))
502 goto out;
503
504 if (ksig->ka.sa.sa_flags & SA_SIGINFO) {
505 err |= copy_siginfo_to_user(&frame->info, &ksig->info);
506 if (err)
507 goto out;
508 }
509
510 /* Create the ucontext. */
511 err |= __put_user(0, &frame->uc.uc_flags);
512 err |= __put_user(0, &frame->uc.uc_link);
513 err |= __save_altstack(&frame->uc.uc_stack, PT_REGS_SP(regs));
514 err |= copy_sc_to_user(&frame->uc.uc_mcontext, &frame->fpstate, regs,
515 set->sig[0]);
516
517 fp_to = (unsigned long)&frame->fpstate;
518
519 err |= __put_user(fp_to, &frame->uc.uc_mcontext.fpstate);
520 if (sizeof(*set) == 16) {
521 err |= __put_user(set->sig[0], &frame->uc.uc_sigmask.sig[0]);
522 err |= __put_user(set->sig[1], &frame->uc.uc_sigmask.sig[1]);
523 }
524 else
525 err |= __copy_to_user(&frame->uc.uc_sigmask, set,
526 sizeof(*set));
527
528 /*
529 * Set up to return from userspace. If provided, use a stub
530 * already in userspace.
531 */
532 /* x86-64 should always use SA_RESTORER. */
533 if (ksig->ka.sa.sa_flags & SA_RESTORER)
534 err |= __put_user((void *)ksig->ka.sa.sa_restorer,
535 &frame->pretcode);
536 else
537 /* could use a vstub here */
538 return err;
539
540 if (err)
541 return err;
542
543 PT_REGS_SP(regs) = (unsigned long) frame;
544 PT_REGS_DI(regs) = sig;
545 /* In case the signal handler was declared without prototypes */
546 PT_REGS_AX(regs) = 0;
547
548 /*
549 * This also works for non SA_SIGINFO handlers because they expect the
550 * next argument after the signal number on the stack.
551 */
552 PT_REGS_SI(regs) = (unsigned long) &frame->info;
553 PT_REGS_DX(regs) = (unsigned long) &frame->uc;
554 PT_REGS_IP(regs) = (unsigned long) ksig->ka.sa.sa_handler;
555 out:
556 return err;
557}
558#endif
559
560long sys_rt_sigreturn(void)
561{
562 unsigned long sp = PT_REGS_SP(¤t->thread.regs);
563 struct rt_sigframe __user *frame =
564 (struct rt_sigframe __user *)(sp - sizeof(long));
565 struct ucontext __user *uc = &frame->uc;
566 sigset_t set;
567
568 if (copy_from_user(&set, &uc->uc_sigmask, sizeof(set)))
569 goto segfault;
570
571 set_current_blocked(&set);
572
573 if (copy_sc_from_user(¤t->thread.regs, &uc->uc_mcontext))
574 goto segfault;
575
576 /* Avoid ERESTART handling */
577 PT_REGS_SYSCALL_NR(¤t->thread.regs) = -1;
578 return PT_REGS_SYSCALL_RET(¤t->thread.regs);
579
580 segfault:
581 force_sig(SIGSEGV);
582 return 0;
583}