[PATCH] fix "sunrpc: fix refcounting problems in rpc servers"
[deliverable/linux.git] / arch / x86_64 / ia32 / ia32_signal.c
CommitLineData
1da177e4
LT
1/*
2 * linux/arch/x86_64/ia32/ia32_signal.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 *
6 * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
7 * 2000-06-20 Pentium III FXSR, SSE support by Gareth Hughes
8 * 2000-12-* x86-64 compatibility mode signal handling by Andi Kleen
1da177e4
LT
9 */
10
11#include <linux/sched.h>
12#include <linux/mm.h>
13#include <linux/smp.h>
14#include <linux/smp_lock.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/personality.h>
23#include <linux/compat.h>
24#include <asm/ucontext.h>
25#include <asm/uaccess.h>
26#include <asm/i387.h>
27#include <asm/ia32.h>
28#include <asm/ptrace.h>
29#include <asm/ia32_unistd.h>
30#include <asm/user32.h>
31#include <asm/sigcontext32.h>
32#include <asm/fpu32.h>
33#include <asm/proto.h>
34#include <asm/vsyscall32.h>
35
36#define DEBUG_SIG 0
37
38#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
39
40asmlinkage int do_signal(struct pt_regs *regs, sigset_t *oldset);
41void signal_fault(struct pt_regs *regs, void __user *frame, char *where);
42
43int copy_siginfo_to_user32(compat_siginfo_t __user *to, siginfo_t *from)
44{
45 int err;
46 if (!access_ok (VERIFY_WRITE, to, sizeof(compat_siginfo_t)))
47 return -EFAULT;
48
49 /* If you change siginfo_t structure, please make sure that
50 this code is fixed accordingly.
51 It should never copy any pad contained in the structure
52 to avoid security leaks, but must copy the generic
53 3 ints plus the relevant union member. */
54 err = __put_user(from->si_signo, &to->si_signo);
55 err |= __put_user(from->si_errno, &to->si_errno);
56 err |= __put_user((short)from->si_code, &to->si_code);
57
58 if (from->si_code < 0) {
59 err |= __put_user(from->si_pid, &to->si_pid);
60 err |= __put_user(from->si_uid, &to->si_uid);
61 err |= __put_user(ptr_to_compat(from->si_ptr), &to->si_ptr);
62 } else {
63 /* First 32bits of unions are always present:
64 * si_pid === si_band === si_tid === si_addr(LS half) */
65 err |= __put_user(from->_sifields._pad[0], &to->_sifields._pad[0]);
66 switch (from->si_code >> 16) {
67 case __SI_FAULT >> 16:
68 break;
69 case __SI_CHLD >> 16:
70 err |= __put_user(from->si_utime, &to->si_utime);
71 err |= __put_user(from->si_stime, &to->si_stime);
72 err |= __put_user(from->si_status, &to->si_status);
73 /* FALL THROUGH */
74 default:
75 case __SI_KILL >> 16:
76 err |= __put_user(from->si_uid, &to->si_uid);
77 break;
78 case __SI_POLL >> 16:
79 err |= __put_user(from->si_fd, &to->si_fd);
80 break;
81 case __SI_TIMER >> 16:
82 err |= __put_user(from->si_overrun, &to->si_overrun);
83 err |= __put_user(ptr_to_compat(from->si_ptr),
84 &to->si_ptr);
85 break;
86 case __SI_RT >> 16: /* This is not generated by the kernel as of now. */
87 case __SI_MESGQ >> 16:
88 err |= __put_user(from->si_uid, &to->si_uid);
89 err |= __put_user(from->si_int, &to->si_int);
90 break;
91 }
92 }
93 return err;
94}
95
96int copy_siginfo_from_user32(siginfo_t *to, compat_siginfo_t __user *from)
97{
98 int err;
99 u32 ptr32;
100 if (!access_ok (VERIFY_READ, from, sizeof(compat_siginfo_t)))
101 return -EFAULT;
102
103 err = __get_user(to->si_signo, &from->si_signo);
104 err |= __get_user(to->si_errno, &from->si_errno);
105 err |= __get_user(to->si_code, &from->si_code);
106
107 err |= __get_user(to->si_pid, &from->si_pid);
108 err |= __get_user(to->si_uid, &from->si_uid);
109 err |= __get_user(ptr32, &from->si_ptr);
110 to->si_ptr = compat_ptr(ptr32);
111
112 return err;
113}
114
115asmlinkage long
1d001df1 116sys32_sigsuspend(int history0, int history1, old_sigset_t mask)
1da177e4 117{
1da177e4
LT
118 mask &= _BLOCKABLE;
119 spin_lock_irq(&current->sighand->siglock);
1d001df1 120 current->saved_sigmask = current->blocked;
1da177e4
LT
121 siginitset(&current->blocked, mask);
122 recalc_sigpending();
123 spin_unlock_irq(&current->sighand->siglock);
124
1d001df1
AK
125 current->state = TASK_INTERRUPTIBLE;
126 schedule();
127 set_thread_flag(TIF_RESTORE_SIGMASK);
128 return -ERESTARTNOHAND;
1da177e4
LT
129}
130
131asmlinkage long
132sys32_sigaltstack(const stack_ia32_t __user *uss_ptr,
133 stack_ia32_t __user *uoss_ptr,
134 struct pt_regs *regs)
135{
136 stack_t uss,uoss;
137 int ret;
138 mm_segment_t seg;
139 if (uss_ptr) {
140 u32 ptr;
141 memset(&uss,0,sizeof(stack_t));
142 if (!access_ok(VERIFY_READ,uss_ptr,sizeof(stack_ia32_t)) ||
143 __get_user(ptr, &uss_ptr->ss_sp) ||
144 __get_user(uss.ss_flags, &uss_ptr->ss_flags) ||
145 __get_user(uss.ss_size, &uss_ptr->ss_size))
146 return -EFAULT;
147 uss.ss_sp = compat_ptr(ptr);
148 }
149 seg = get_fs();
150 set_fs(KERNEL_DS);
151 ret = do_sigaltstack(uss_ptr ? &uss : NULL, &uoss, regs->rsp);
152 set_fs(seg);
153 if (ret >= 0 && uoss_ptr) {
154 if (!access_ok(VERIFY_WRITE,uoss_ptr,sizeof(stack_ia32_t)) ||
155 __put_user(ptr_to_compat(uoss.ss_sp), &uoss_ptr->ss_sp) ||
156 __put_user(uoss.ss_flags, &uoss_ptr->ss_flags) ||
157 __put_user(uoss.ss_size, &uoss_ptr->ss_size))
158 ret = -EFAULT;
159 }
160 return ret;
161}
162
163/*
164 * Do a signal return; undo the signal stack.
165 */
166
167struct sigframe
168{
169 u32 pretcode;
170 int sig;
171 struct sigcontext_ia32 sc;
172 struct _fpstate_ia32 fpstate;
173 unsigned int extramask[_COMPAT_NSIG_WORDS-1];
174 char retcode[8];
175};
176
177struct rt_sigframe
178{
179 u32 pretcode;
180 int sig;
181 u32 pinfo;
182 u32 puc;
183 compat_siginfo_t info;
184 struct ucontext_ia32 uc;
185 struct _fpstate_ia32 fpstate;
186 char retcode[8];
187};
188
189static int
190ia32_restore_sigcontext(struct pt_regs *regs, struct sigcontext_ia32 __user *sc, unsigned int *peax)
191{
192 unsigned int err = 0;
193
194 /* Always make any pending restarted system calls return -EINTR */
195 current_thread_info()->restart_block.fn = do_no_restart_syscall;
196
197#if DEBUG_SIG
198 printk("SIG restore_sigcontext: sc=%p err(%x) eip(%x) cs(%x) flg(%x)\n",
199 sc, sc->err, sc->eip, sc->cs, sc->eflags);
200#endif
201#define COPY(x) { \
202 unsigned int reg; \
203 err |= __get_user(reg, &sc->e ##x); \
204 regs->r ## x = reg; \
205}
206
207#define RELOAD_SEG(seg,mask) \
208 { unsigned int cur; \
209 unsigned short pre; \
210 err |= __get_user(pre, &sc->seg); \
211 asm volatile("movl %%" #seg ",%0" : "=r" (cur)); \
212 pre |= mask; \
213 if (pre != cur) loadsegment(seg,pre); }
214
215 /* Reload fs and gs if they have changed in the signal handler.
216 This does not handle long fs/gs base changes in the handler, but
217 does not clobber them at least in the normal case. */
218
219 {
220 unsigned gs, oldgs;
221 err |= __get_user(gs, &sc->gs);
222 gs |= 3;
223 asm("movl %%gs,%0" : "=r" (oldgs));
224 if (gs != oldgs)
225 load_gs_index(gs);
226 }
227 RELOAD_SEG(fs,3);
228 RELOAD_SEG(ds,3);
229 RELOAD_SEG(es,3);
230
231 COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx);
232 COPY(dx); COPY(cx); COPY(ip);
233 /* Don't touch extended registers */
234
235 err |= __get_user(regs->cs, &sc->cs);
236 regs->cs |= 3;
237 err |= __get_user(regs->ss, &sc->ss);
238 regs->ss |= 3;
239
240 {
241 unsigned int tmpflags;
242 err |= __get_user(tmpflags, &sc->eflags);
243 regs->eflags = (regs->eflags & ~0x40DD5) | (tmpflags & 0x40DD5);
244 regs->orig_rax = -1; /* disable syscall checks */
245 }
246
247 {
248 u32 tmp;
249 struct _fpstate_ia32 __user * buf;
250 err |= __get_user(tmp, &sc->fpstate);
251 buf = compat_ptr(tmp);
252 if (buf) {
253 if (!access_ok(VERIFY_READ, buf, sizeof(*buf)))
254 goto badframe;
255 err |= restore_i387_ia32(current, buf, 0);
256 } else {
257 struct task_struct *me = current;
258 if (used_math()) {
259 clear_fpu(me);
260 clear_used_math();
261 }
262 }
263 }
264
265 {
266 u32 tmp;
267 err |= __get_user(tmp, &sc->eax);
268 *peax = tmp;
269 }
270 return err;
271
272badframe:
273 return 1;
274}
275
276asmlinkage long sys32_sigreturn(struct pt_regs *regs)
277{
278 struct sigframe __user *frame = (struct sigframe __user *)(regs->rsp-8);
279 sigset_t set;
280 unsigned int eax;
281
282 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
283 goto badframe;
284 if (__get_user(set.sig[0], &frame->sc.oldmask)
285 || (_COMPAT_NSIG_WORDS > 1
286 && __copy_from_user((((char *) &set.sig) + 4), &frame->extramask,
287 sizeof(frame->extramask))))
288 goto badframe;
289
290 sigdelsetmask(&set, ~_BLOCKABLE);
291 spin_lock_irq(&current->sighand->siglock);
292 current->blocked = set;
293 recalc_sigpending();
294 spin_unlock_irq(&current->sighand->siglock);
295
296 if (ia32_restore_sigcontext(regs, &frame->sc, &eax))
297 goto badframe;
298 return eax;
299
300badframe:
301 signal_fault(regs, frame, "32bit sigreturn");
302 return 0;
303}
304
305asmlinkage long sys32_rt_sigreturn(struct pt_regs *regs)
306{
307 struct rt_sigframe __user *frame;
308 sigset_t set;
309 unsigned int eax;
310 struct pt_regs tregs;
311
312 frame = (struct rt_sigframe __user *)(regs->rsp - 4);
313
314 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
315 goto badframe;
316 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
317 goto badframe;
318
319 sigdelsetmask(&set, ~_BLOCKABLE);
320 spin_lock_irq(&current->sighand->siglock);
321 current->blocked = set;
322 recalc_sigpending();
323 spin_unlock_irq(&current->sighand->siglock);
324
325 if (ia32_restore_sigcontext(regs, &frame->uc.uc_mcontext, &eax))
326 goto badframe;
327
328 tregs = *regs;
329 if (sys32_sigaltstack(&frame->uc.uc_stack, NULL, &tregs) == -EFAULT)
330 goto badframe;
331
332 return eax;
333
334badframe:
335 signal_fault(regs,frame,"32bit rt sigreturn");
336 return 0;
337}
338
339/*
340 * Set up a signal frame.
341 */
342
343static int
344ia32_setup_sigcontext(struct sigcontext_ia32 __user *sc, struct _fpstate_ia32 __user *fpstate,
345 struct pt_regs *regs, unsigned int mask)
346{
347 int tmp, err = 0;
1da177e4
LT
348
349 tmp = 0;
350 __asm__("movl %%gs,%0" : "=r"(tmp): "0"(tmp));
351 err |= __put_user(tmp, (unsigned int __user *)&sc->gs);
352 __asm__("movl %%fs,%0" : "=r"(tmp): "0"(tmp));
353 err |= __put_user(tmp, (unsigned int __user *)&sc->fs);
354 __asm__("movl %%ds,%0" : "=r"(tmp): "0"(tmp));
355 err |= __put_user(tmp, (unsigned int __user *)&sc->ds);
356 __asm__("movl %%es,%0" : "=r"(tmp): "0"(tmp));
357 err |= __put_user(tmp, (unsigned int __user *)&sc->es);
358
359 err |= __put_user((u32)regs->rdi, &sc->edi);
360 err |= __put_user((u32)regs->rsi, &sc->esi);
361 err |= __put_user((u32)regs->rbp, &sc->ebp);
362 err |= __put_user((u32)regs->rsp, &sc->esp);
363 err |= __put_user((u32)regs->rbx, &sc->ebx);
364 err |= __put_user((u32)regs->rdx, &sc->edx);
365 err |= __put_user((u32)regs->rcx, &sc->ecx);
366 err |= __put_user((u32)regs->rax, &sc->eax);
367 err |= __put_user((u32)regs->cs, &sc->cs);
368 err |= __put_user((u32)regs->ss, &sc->ss);
369 err |= __put_user(current->thread.trap_no, &sc->trapno);
370 err |= __put_user(current->thread.error_code, &sc->err);
371 err |= __put_user((u32)regs->rip, &sc->eip);
4724e3e8 372 err |= __put_user((u32)regs->eflags, &sc->eflags);
1da177e4
LT
373 err |= __put_user((u32)regs->rsp, &sc->esp_at_signal);
374
375 tmp = save_i387_ia32(current, fpstate, regs, 0);
376 if (tmp < 0)
377 err = -EFAULT;
378 else {
379 clear_used_math();
380 stts();
381 err |= __put_user(ptr_to_compat(tmp ? fpstate : NULL),
382 &sc->fpstate);
383 }
384
385 /* non-iBCS2 extensions.. */
386 err |= __put_user(mask, &sc->oldmask);
387 err |= __put_user(current->thread.cr2, &sc->cr2);
388
389 return err;
390}
391
392/*
393 * Determine which stack to use..
394 */
395static void __user *
396get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size)
397{
398 unsigned long rsp;
399
400 /* Default to using normal stack */
401 rsp = regs->rsp;
402
403 /* This is the X/Open sanctioned signal stack switching. */
404 if (ka->sa.sa_flags & SA_ONSTACK) {
405 if (sas_ss_flags(rsp) == 0)
406 rsp = current->sas_ss_sp + current->sas_ss_size;
407 }
408
409 /* This is the legacy signal stack switching. */
410 else if ((regs->ss & 0xffff) != __USER_DS &&
411 !(ka->sa.sa_flags & SA_RESTORER) &&
412 ka->sa.sa_restorer) {
413 rsp = (unsigned long) ka->sa.sa_restorer;
414 }
415
d347f372
MO
416 rsp -= frame_size;
417 /* Align the stack pointer according to the i386 ABI,
418 * i.e. so that on function entry ((sp + 4) & 15) == 0. */
419 rsp = ((rsp + 4) & -16ul) - 4;
420 return (void __user *) rsp;
1da177e4
LT
421}
422
0928d6ef
RM
423int ia32_setup_frame(int sig, struct k_sigaction *ka,
424 compat_sigset_t *set, struct pt_regs * regs)
1da177e4
LT
425{
426 struct sigframe __user *frame;
427 int err = 0;
428
429 frame = get_sigframe(ka, regs, sizeof(*frame));
430
431 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
432 goto give_sigsegv;
433
dd54a110 434 err |= __put_user(sig, &frame->sig);
1da177e4
LT
435 if (err)
436 goto give_sigsegv;
437
438 err |= ia32_setup_sigcontext(&frame->sc, &frame->fpstate, regs,
439 set->sig[0]);
440 if (err)
441 goto give_sigsegv;
442
443 if (_COMPAT_NSIG_WORDS > 1) {
444 err |= __copy_to_user(frame->extramask, &set->sig[1],
445 sizeof(frame->extramask));
446 }
447 if (err)
448 goto give_sigsegv;
449
450 /* Return stub is in 32bit vsyscall page */
451 {
452 void __user *restorer = VSYSCALL32_SIGRETURN;
453 if (ka->sa.sa_flags & SA_RESTORER)
454 restorer = ka->sa.sa_restorer;
455 err |= __put_user(ptr_to_compat(restorer), &frame->pretcode);
456 }
457 /* These are actually not used anymore, but left because some
458 gdb versions depend on them as a marker. */
459 {
460 /* copy_to_user optimizes that into a single 8 byte store */
461 static const struct {
462 u16 poplmovl;
463 u32 val;
464 u16 int80;
465 u16 pad;
466 } __attribute__((packed)) code = {
467 0xb858, /* popl %eax ; movl $...,%eax */
468 __NR_ia32_sigreturn,
469 0x80cd, /* int $0x80 */
470 0,
471 };
472 err |= __copy_to_user(frame->retcode, &code, 8);
473 }
474 if (err)
475 goto give_sigsegv;
476
477 /* Set up registers for signal handler */
478 regs->rsp = (unsigned long) frame;
479 regs->rip = (unsigned long) ka->sa.sa_handler;
480
536e3ee4
AK
481 /* Make -mregparm=3 work */
482 regs->rax = sig;
483 regs->rdx = 0;
484 regs->rcx = 0;
485
1da177e4
LT
486 asm volatile("movl %0,%%ds" :: "r" (__USER32_DS));
487 asm volatile("movl %0,%%es" :: "r" (__USER32_DS));
488
489 regs->cs = __USER32_CS;
490 regs->ss = __USER32_DS;
491
492 set_fs(USER_DS);
ab2e0b46
AK
493 regs->eflags &= ~TF_MASK;
494 if (test_thread_flag(TIF_SINGLESTEP))
495 ptrace_notify(SIGTRAP);
1da177e4
LT
496
497#if DEBUG_SIG
498 printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n",
499 current->comm, current->pid, frame, regs->rip, frame->pretcode);
500#endif
501
1d001df1 502 return 0;
1da177e4
LT
503
504give_sigsegv:
505 force_sigsegv(sig, current);
1d001df1 506 return -EFAULT;
1da177e4
LT
507}
508
0928d6ef
RM
509int ia32_setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
510 compat_sigset_t *set, struct pt_regs * regs)
1da177e4
LT
511{
512 struct rt_sigframe __user *frame;
513 int err = 0;
514
515 frame = get_sigframe(ka, regs, sizeof(*frame));
516
517 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
518 goto give_sigsegv;
519
520 {
521 struct exec_domain *ed = current_thread_info()->exec_domain;
522 err |= __put_user((ed
523 && ed->signal_invmap
524 && sig < 32
525 ? ed->signal_invmap[sig]
526 : sig),
527 &frame->sig);
528 }
529 err |= __put_user(ptr_to_compat(&frame->info), &frame->pinfo);
530 err |= __put_user(ptr_to_compat(&frame->uc), &frame->puc);
531 err |= copy_siginfo_to_user32(&frame->info, info);
532 if (err)
533 goto give_sigsegv;
534
535 /* Create the ucontext. */
536 err |= __put_user(0, &frame->uc.uc_flags);
537 err |= __put_user(0, &frame->uc.uc_link);
538 err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
539 err |= __put_user(sas_ss_flags(regs->rsp),
540 &frame->uc.uc_stack.ss_flags);
541 err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
542 err |= ia32_setup_sigcontext(&frame->uc.uc_mcontext, &frame->fpstate,
543 regs, set->sig[0]);
544 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
545 if (err)
546 goto give_sigsegv;
547
548
549 {
550 void __user *restorer = VSYSCALL32_RTSIGRETURN;
551 if (ka->sa.sa_flags & SA_RESTORER)
552 restorer = ka->sa.sa_restorer;
553 err |= __put_user(ptr_to_compat(restorer), &frame->pretcode);
554 }
555
556 /* This is movl $,%eax ; int $0x80 */
557 /* Not actually used anymore, but left because some gdb versions
558 need it. */
559 {
560 /* __copy_to_user optimizes that into a single 8 byte store */
561 static const struct {
562 u8 movl;
563 u32 val;
564 u16 int80;
565 u16 pad;
566 u8 pad2;
567 } __attribute__((packed)) code = {
568 0xb8,
569 __NR_ia32_rt_sigreturn,
570 0x80cd,
571 0,
572 };
573 err |= __copy_to_user(frame->retcode, &code, 8);
574 }
575 if (err)
576 goto give_sigsegv;
577
578 /* Set up registers for signal handler */
579 regs->rsp = (unsigned long) frame;
580 regs->rip = (unsigned long) ka->sa.sa_handler;
581
582 asm volatile("movl %0,%%ds" :: "r" (__USER32_DS));
583 asm volatile("movl %0,%%es" :: "r" (__USER32_DS));
584
585 regs->cs = __USER32_CS;
586 regs->ss = __USER32_DS;
587
588 set_fs(USER_DS);
1d001df1 589 regs->eflags &= ~TF_MASK;
ab2e0b46
AK
590 if (test_thread_flag(TIF_SINGLESTEP))
591 ptrace_notify(SIGTRAP);
1da177e4
LT
592
593#if DEBUG_SIG
594 printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n",
595 current->comm, current->pid, frame, regs->rip, frame->pretcode);
596#endif
597
1d001df1 598 return 0;
1da177e4
LT
599
600give_sigsegv:
601 force_sigsegv(sig, current);
1d001df1 602 return -EFAULT;
1da177e4 603}
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