Merge remote-tracking branch 'battery/master'
[linux-2.6/next.git] / arch / um / sys-i386 / signal.c
blob89a46626bfd894c54d683622b7148633c1f91c97
1 /*
2 * Copyright (C) 2004 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
3 * Licensed under the GPL
4 */
6 #include <linux/ptrace.h>
7 #include <asm/unistd.h>
8 #include <asm/uaccess.h>
9 #include <asm/ucontext.h>
10 #include "frame_kern.h"
11 #include "skas.h"
13 void copy_sc(struct uml_pt_regs *regs, void *from)
15 struct sigcontext *sc = from;
17 REGS_GS(regs->gp) = sc->gs;
18 REGS_FS(regs->gp) = sc->fs;
19 REGS_ES(regs->gp) = sc->es;
20 REGS_DS(regs->gp) = sc->ds;
21 REGS_EDI(regs->gp) = sc->di;
22 REGS_ESI(regs->gp) = sc->si;
23 REGS_EBP(regs->gp) = sc->bp;
24 REGS_SP(regs->gp) = sc->sp;
25 REGS_EBX(regs->gp) = sc->bx;
26 REGS_EDX(regs->gp) = sc->dx;
27 REGS_ECX(regs->gp) = sc->cx;
28 REGS_EAX(regs->gp) = sc->ax;
29 REGS_IP(regs->gp) = sc->ip;
30 REGS_CS(regs->gp) = sc->cs;
31 REGS_EFLAGS(regs->gp) = sc->flags;
32 REGS_SS(regs->gp) = sc->ss;
36 * FPU tag word conversions.
39 static inline unsigned short twd_i387_to_fxsr(unsigned short twd)
41 unsigned int tmp; /* to avoid 16 bit prefixes in the code */
43 /* Transform each pair of bits into 01 (valid) or 00 (empty) */
44 tmp = ~twd;
45 tmp = (tmp | (tmp>>1)) & 0x5555; /* 0V0V0V0V0V0V0V0V */
46 /* and move the valid bits to the lower byte. */
47 tmp = (tmp | (tmp >> 1)) & 0x3333; /* 00VV00VV00VV00VV */
48 tmp = (tmp | (tmp >> 2)) & 0x0f0f; /* 0000VVVV0000VVVV */
49 tmp = (tmp | (tmp >> 4)) & 0x00ff; /* 00000000VVVVVVVV */
50 return tmp;
53 static inline unsigned long twd_fxsr_to_i387(struct user_fxsr_struct *fxsave)
55 struct _fpxreg *st = NULL;
56 unsigned long twd = (unsigned long) fxsave->twd;
57 unsigned long tag;
58 unsigned long ret = 0xffff0000;
59 int i;
61 #define FPREG_ADDR(f, n) ((char *)&(f)->st_space + (n) * 16)
63 for (i = 0; i < 8; i++) {
64 if (twd & 0x1) {
65 st = (struct _fpxreg *) FPREG_ADDR(fxsave, i);
67 switch (st->exponent & 0x7fff) {
68 case 0x7fff:
69 tag = 2; /* Special */
70 break;
71 case 0x0000:
72 if ( !st->significand[0] &&
73 !st->significand[1] &&
74 !st->significand[2] &&
75 !st->significand[3] ) {
76 tag = 1; /* Zero */
77 } else {
78 tag = 2; /* Special */
80 break;
81 default:
82 if (st->significand[3] & 0x8000) {
83 tag = 0; /* Valid */
84 } else {
85 tag = 2; /* Special */
87 break;
89 } else {
90 tag = 3; /* Empty */
92 ret |= (tag << (2 * i));
93 twd = twd >> 1;
95 return ret;
98 static int convert_fxsr_to_user(struct _fpstate __user *buf,
99 struct user_fxsr_struct *fxsave)
101 unsigned long env[7];
102 struct _fpreg __user *to;
103 struct _fpxreg *from;
104 int i;
106 env[0] = (unsigned long)fxsave->cwd | 0xffff0000ul;
107 env[1] = (unsigned long)fxsave->swd | 0xffff0000ul;
108 env[2] = twd_fxsr_to_i387(fxsave);
109 env[3] = fxsave->fip;
110 env[4] = fxsave->fcs | ((unsigned long)fxsave->fop << 16);
111 env[5] = fxsave->foo;
112 env[6] = fxsave->fos;
114 if (__copy_to_user(buf, env, 7 * sizeof(unsigned long)))
115 return 1;
117 to = &buf->_st[0];
118 from = (struct _fpxreg *) &fxsave->st_space[0];
119 for (i = 0; i < 8; i++, to++, from++) {
120 unsigned long __user *t = (unsigned long __user *)to;
121 unsigned long *f = (unsigned long *)from;
123 if (__put_user(*f, t) ||
124 __put_user(*(f + 1), t + 1) ||
125 __put_user(from->exponent, &to->exponent))
126 return 1;
128 return 0;
131 static int convert_fxsr_from_user(struct user_fxsr_struct *fxsave,
132 struct _fpstate __user *buf)
134 unsigned long env[7];
135 struct _fpxreg *to;
136 struct _fpreg __user *from;
137 int i;
139 if (copy_from_user( env, buf, 7 * sizeof(long)))
140 return 1;
142 fxsave->cwd = (unsigned short)(env[0] & 0xffff);
143 fxsave->swd = (unsigned short)(env[1] & 0xffff);
144 fxsave->twd = twd_i387_to_fxsr((unsigned short)(env[2] & 0xffff));
145 fxsave->fip = env[3];
146 fxsave->fop = (unsigned short)((env[4] & 0xffff0000ul) >> 16);
147 fxsave->fcs = (env[4] & 0xffff);
148 fxsave->foo = env[5];
149 fxsave->fos = env[6];
151 to = (struct _fpxreg *) &fxsave->st_space[0];
152 from = &buf->_st[0];
153 for (i = 0; i < 8; i++, to++, from++) {
154 unsigned long *t = (unsigned long *)to;
155 unsigned long __user *f = (unsigned long __user *)from;
157 if (__get_user(*t, f) ||
158 __get_user(*(t + 1), f + 1) ||
159 __get_user(to->exponent, &from->exponent))
160 return 1;
162 return 0;
165 extern int have_fpx_regs;
167 static int copy_sc_from_user(struct pt_regs *regs,
168 struct sigcontext __user *from)
170 struct sigcontext sc;
171 int err, pid;
173 err = copy_from_user(&sc, from, sizeof(sc));
174 if (err)
175 return err;
177 pid = userspace_pid[current_thread_info()->cpu];
178 copy_sc(&regs->regs, &sc);
179 if (have_fpx_regs) {
180 struct user_fxsr_struct fpx;
182 err = copy_from_user(&fpx,
183 &((struct _fpstate __user *)sc.fpstate)->_fxsr_env[0],
184 sizeof(struct user_fxsr_struct));
185 if (err)
186 return 1;
188 err = convert_fxsr_from_user(&fpx, sc.fpstate);
189 if (err)
190 return 1;
192 err = restore_fpx_registers(pid, (unsigned long *) &fpx);
193 if (err < 0) {
194 printk(KERN_ERR "copy_sc_from_user - "
195 "restore_fpx_registers failed, errno = %d\n",
196 -err);
197 return 1;
200 else {
201 struct user_i387_struct fp;
203 err = copy_from_user(&fp, sc.fpstate,
204 sizeof(struct user_i387_struct));
205 if (err)
206 return 1;
208 err = restore_fp_registers(pid, (unsigned long *) &fp);
209 if (err < 0) {
210 printk(KERN_ERR "copy_sc_from_user - "
211 "restore_fp_registers failed, errno = %d\n",
212 -err);
213 return 1;
217 return 0;
220 static int copy_sc_to_user(struct sigcontext __user *to,
221 struct _fpstate __user *to_fp, struct pt_regs *regs,
222 unsigned long sp)
224 struct sigcontext sc;
225 struct faultinfo * fi = &current->thread.arch.faultinfo;
226 int err, pid;
228 sc.gs = REGS_GS(regs->regs.gp);
229 sc.fs = REGS_FS(regs->regs.gp);
230 sc.es = REGS_ES(regs->regs.gp);
231 sc.ds = REGS_DS(regs->regs.gp);
232 sc.di = REGS_EDI(regs->regs.gp);
233 sc.si = REGS_ESI(regs->regs.gp);
234 sc.bp = REGS_EBP(regs->regs.gp);
235 sc.sp = sp;
236 sc.bx = REGS_EBX(regs->regs.gp);
237 sc.dx = REGS_EDX(regs->regs.gp);
238 sc.cx = REGS_ECX(regs->regs.gp);
239 sc.ax = REGS_EAX(regs->regs.gp);
240 sc.ip = REGS_IP(regs->regs.gp);
241 sc.cs = REGS_CS(regs->regs.gp);
242 sc.flags = REGS_EFLAGS(regs->regs.gp);
243 sc.sp_at_signal = regs->regs.gp[UESP];
244 sc.ss = regs->regs.gp[SS];
245 sc.cr2 = fi->cr2;
246 sc.err = fi->error_code;
247 sc.trapno = fi->trap_no;
249 to_fp = (to_fp ? to_fp : (struct _fpstate __user *) (to + 1));
250 sc.fpstate = to_fp;
252 pid = userspace_pid[current_thread_info()->cpu];
253 if (have_fpx_regs) {
254 struct user_fxsr_struct fpx;
256 err = save_fpx_registers(pid, (unsigned long *) &fpx);
257 if (err < 0){
258 printk(KERN_ERR "copy_sc_to_user - save_fpx_registers "
259 "failed, errno = %d\n", err);
260 return 1;
263 err = convert_fxsr_to_user(to_fp, &fpx);
264 if (err)
265 return 1;
267 err |= __put_user(fpx.swd, &to_fp->status);
268 err |= __put_user(X86_FXSR_MAGIC, &to_fp->magic);
269 if (err)
270 return 1;
272 if (copy_to_user(&to_fp->_fxsr_env[0], &fpx,
273 sizeof(struct user_fxsr_struct)))
274 return 1;
276 else {
277 struct user_i387_struct fp;
279 err = save_fp_registers(pid, (unsigned long *) &fp);
280 if (copy_to_user(to_fp, &fp, sizeof(struct user_i387_struct)))
281 return 1;
284 return copy_to_user(to, &sc, sizeof(sc));
287 static int copy_ucontext_to_user(struct ucontext __user *uc,
288 struct _fpstate __user *fp, sigset_t *set,
289 unsigned long sp)
291 int err = 0;
293 err |= put_user(current->sas_ss_sp, &uc->uc_stack.ss_sp);
294 err |= put_user(sas_ss_flags(sp), &uc->uc_stack.ss_flags);
295 err |= put_user(current->sas_ss_size, &uc->uc_stack.ss_size);
296 err |= copy_sc_to_user(&uc->uc_mcontext, fp, &current->thread.regs, sp);
297 err |= copy_to_user(&uc->uc_sigmask, set, sizeof(*set));
298 return err;
301 struct sigframe
303 char __user *pretcode;
304 int sig;
305 struct sigcontext sc;
306 struct _fpstate fpstate;
307 unsigned long extramask[_NSIG_WORDS-1];
308 char retcode[8];
311 struct rt_sigframe
313 char __user *pretcode;
314 int sig;
315 struct siginfo __user *pinfo;
316 void __user *puc;
317 struct siginfo info;
318 struct ucontext uc;
319 struct _fpstate fpstate;
320 char retcode[8];
323 int setup_signal_stack_sc(unsigned long stack_top, int sig,
324 struct k_sigaction *ka, struct pt_regs *regs,
325 sigset_t *mask)
327 struct sigframe __user *frame;
328 void __user *restorer;
329 unsigned long save_sp = PT_REGS_SP(regs);
330 int err = 0;
332 /* This is the same calculation as i386 - ((sp + 4) & 15) == 0 */
333 stack_top = ((stack_top + 4) & -16UL) - 4;
334 frame = (struct sigframe __user *) stack_top - 1;
335 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
336 return 1;
338 restorer = frame->retcode;
339 if (ka->sa.sa_flags & SA_RESTORER)
340 restorer = ka->sa.sa_restorer;
342 /* Update SP now because the page fault handler refuses to extend
343 * the stack if the faulting address is too far below the current
344 * SP, which frame now certainly is. If there's an error, the original
345 * value is restored on the way out.
346 * When writing the sigcontext to the stack, we have to write the
347 * original value, so that's passed to copy_sc_to_user, which does
348 * the right thing with it.
350 PT_REGS_SP(regs) = (unsigned long) frame;
352 err |= __put_user(restorer, &frame->pretcode);
353 err |= __put_user(sig, &frame->sig);
354 err |= copy_sc_to_user(&frame->sc, NULL, regs, save_sp);
355 err |= __put_user(mask->sig[0], &frame->sc.oldmask);
356 if (_NSIG_WORDS > 1)
357 err |= __copy_to_user(&frame->extramask, &mask->sig[1],
358 sizeof(frame->extramask));
361 * This is popl %eax ; movl $,%eax ; int $0x80
363 * WE DO NOT USE IT ANY MORE! It's only left here for historical
364 * reasons and because gdb uses it as a signature to notice
365 * signal handler stack frames.
367 err |= __put_user(0xb858, (short __user *)(frame->retcode+0));
368 err |= __put_user(__NR_sigreturn, (int __user *)(frame->retcode+2));
369 err |= __put_user(0x80cd, (short __user *)(frame->retcode+6));
371 if (err)
372 goto err;
374 PT_REGS_SP(regs) = (unsigned long) frame;
375 PT_REGS_IP(regs) = (unsigned long) ka->sa.sa_handler;
376 PT_REGS_EAX(regs) = (unsigned long) sig;
377 PT_REGS_EDX(regs) = (unsigned long) 0;
378 PT_REGS_ECX(regs) = (unsigned long) 0;
380 if ((current->ptrace & PT_DTRACE) && (current->ptrace & PT_PTRACED))
381 ptrace_notify(SIGTRAP);
382 return 0;
384 err:
385 PT_REGS_SP(regs) = save_sp;
386 return err;
389 int setup_signal_stack_si(unsigned long stack_top, int sig,
390 struct k_sigaction *ka, struct pt_regs *regs,
391 siginfo_t *info, sigset_t *mask)
393 struct rt_sigframe __user *frame;
394 void __user *restorer;
395 unsigned long save_sp = PT_REGS_SP(regs);
396 int err = 0;
398 stack_top &= -8UL;
399 frame = (struct rt_sigframe __user *) stack_top - 1;
400 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
401 return 1;
403 restorer = frame->retcode;
404 if (ka->sa.sa_flags & SA_RESTORER)
405 restorer = ka->sa.sa_restorer;
407 /* See comment above about why this is here */
408 PT_REGS_SP(regs) = (unsigned long) frame;
410 err |= __put_user(restorer, &frame->pretcode);
411 err |= __put_user(sig, &frame->sig);
412 err |= __put_user(&frame->info, &frame->pinfo);
413 err |= __put_user(&frame->uc, &frame->puc);
414 err |= copy_siginfo_to_user(&frame->info, info);
415 err |= copy_ucontext_to_user(&frame->uc, &frame->fpstate, mask,
416 save_sp);
419 * This is movl $,%eax ; int $0x80
421 * WE DO NOT USE IT ANY MORE! It's only left here for historical
422 * reasons and because gdb uses it as a signature to notice
423 * signal handler stack frames.
425 err |= __put_user(0xb8, (char __user *)(frame->retcode+0));
426 err |= __put_user(__NR_rt_sigreturn, (int __user *)(frame->retcode+1));
427 err |= __put_user(0x80cd, (short __user *)(frame->retcode+5));
429 if (err)
430 goto err;
432 PT_REGS_IP(regs) = (unsigned long) ka->sa.sa_handler;
433 PT_REGS_EAX(regs) = (unsigned long) sig;
434 PT_REGS_EDX(regs) = (unsigned long) &frame->info;
435 PT_REGS_ECX(regs) = (unsigned long) &frame->uc;
437 if ((current->ptrace & PT_DTRACE) && (current->ptrace & PT_PTRACED))
438 ptrace_notify(SIGTRAP);
439 return 0;
441 err:
442 PT_REGS_SP(regs) = save_sp;
443 return err;
446 long sys_sigreturn(struct pt_regs regs)
448 unsigned long sp = PT_REGS_SP(&current->thread.regs);
449 struct sigframe __user *frame = (struct sigframe __user *)(sp - 8);
450 sigset_t set;
451 struct sigcontext __user *sc = &frame->sc;
452 unsigned long __user *oldmask = &sc->oldmask;
453 unsigned long __user *extramask = frame->extramask;
454 int sig_size = (_NSIG_WORDS - 1) * sizeof(unsigned long);
456 if (copy_from_user(&set.sig[0], oldmask, sizeof(set.sig[0])) ||
457 copy_from_user(&set.sig[1], extramask, sig_size))
458 goto segfault;
460 sigdelsetmask(&set, ~_BLOCKABLE);
462 spin_lock_irq(&current->sighand->siglock);
463 current->blocked = set;
464 recalc_sigpending();
465 spin_unlock_irq(&current->sighand->siglock);
467 if (copy_sc_from_user(&current->thread.regs, sc))
468 goto segfault;
470 /* Avoid ERESTART handling */
471 PT_REGS_SYSCALL_NR(&current->thread.regs) = -1;
472 return PT_REGS_SYSCALL_RET(&current->thread.regs);
474 segfault:
475 force_sig(SIGSEGV, current);
476 return 0;
479 long sys_rt_sigreturn(struct pt_regs regs)
481 unsigned long sp = PT_REGS_SP(&current->thread.regs);
482 struct rt_sigframe __user *frame =
483 (struct rt_sigframe __user *) (sp - 4);
484 sigset_t set;
485 struct ucontext __user *uc = &frame->uc;
486 int sig_size = _NSIG_WORDS * sizeof(unsigned long);
488 if (copy_from_user(&set, &uc->uc_sigmask, sig_size))
489 goto segfault;
491 sigdelsetmask(&set, ~_BLOCKABLE);
493 spin_lock_irq(&current->sighand->siglock);
494 current->blocked = set;
495 recalc_sigpending();
496 spin_unlock_irq(&current->sighand->siglock);
498 if (copy_sc_from_user(&current->thread.regs, &uc->uc_mcontext))
499 goto segfault;
501 /* Avoid ERESTART handling */
502 PT_REGS_SYSCALL_NR(&current->thread.regs) = -1;
503 return PT_REGS_SYSCALL_RET(&current->thread.regs);
505 segfault:
506 force_sig(SIGSEGV, current);
507 return 0;