71993c6a7d94b0f6da895f78d96176de5aa31e14
[deliverable/linux.git] / arch / sh / kernel / signal_64.c
1 /*
2 * arch/sh/kernel/signal_64.c
3 *
4 * Copyright (C) 2000, 2001 Paolo Alberelli
5 * Copyright (C) 2003 - 2008 Paul Mundt
6 * Copyright (C) 2004 Richard Curnow
7 *
8 * This file is subject to the terms and conditions of the GNU General Public
9 * License. See the file "COPYING" in the main directory of this archive
10 * for more details.
11 */
12 #include <linux/rwsem.h>
13 #include <linux/sched.h>
14 #include <linux/mm.h>
15 #include <linux/smp.h>
16 #include <linux/kernel.h>
17 #include <linux/signal.h>
18 #include <linux/errno.h>
19 #include <linux/wait.h>
20 #include <linux/personality.h>
21 #include <linux/ptrace.h>
22 #include <linux/unistd.h>
23 #include <linux/stddef.h>
24 #include <linux/tracehook.h>
25 #include <asm/ucontext.h>
26 #include <asm/uaccess.h>
27 #include <asm/pgtable.h>
28 #include <asm/cacheflush.h>
29 #include <asm/fpu.h>
30
31 #define REG_RET 9
32 #define REG_ARG1 2
33 #define REG_ARG2 3
34 #define REG_ARG3 4
35 #define REG_SP 15
36 #define REG_PR 18
37 #define REF_REG_RET regs->regs[REG_RET]
38 #define REF_REG_SP regs->regs[REG_SP]
39 #define DEREF_REG_PR regs->regs[REG_PR]
40
41 #define DEBUG_SIG 0
42
43 static void
44 handle_signal(struct ksignal *ksig, struct pt_regs *regs);
45
46 static inline void
47 handle_syscall_restart(struct pt_regs *regs, struct sigaction *sa)
48 {
49 /* If we're not from a syscall, bail out */
50 if (regs->syscall_nr < 0)
51 return;
52
53 /* check for system call restart.. */
54 switch (regs->regs[REG_RET]) {
55 case -ERESTART_RESTARTBLOCK:
56 case -ERESTARTNOHAND:
57 no_system_call_restart:
58 regs->regs[REG_RET] = -EINTR;
59 break;
60
61 case -ERESTARTSYS:
62 if (!(sa->sa_flags & SA_RESTART))
63 goto no_system_call_restart;
64 /* fallthrough */
65 case -ERESTARTNOINTR:
66 /* Decode syscall # */
67 regs->regs[REG_RET] = regs->syscall_nr;
68 regs->pc -= 4;
69 break;
70 }
71 }
72
73 /*
74 * Note that 'init' is a special process: it doesn't get signals it doesn't
75 * want to handle. Thus you cannot kill init even with a SIGKILL even by
76 * mistake.
77 *
78 * Note that we go through the signals twice: once to check the signals that
79 * the kernel can handle, and then we build all the user-level signal handling
80 * stack-frames in one go after that.
81 */
82 static void do_signal(struct pt_regs *regs)
83 {
84 struct ksignal ksig;
85
86 /*
87 * We want the common case to go fast, which
88 * is why we may in certain cases get here from
89 * kernel mode. Just return without doing anything
90 * if so.
91 */
92 if (!user_mode(regs))
93 return;
94
95 if (get_signal(&ksig)) {
96 handle_syscall_restart(regs, &ksig.ka.sa);
97
98 /* Whee! Actually deliver the signal. */
99 handle_signal(&ksig, regs);
100 return;
101 }
102
103 /* Did we come from a system call? */
104 if (regs->syscall_nr >= 0) {
105 /* Restart the system call - no handlers present */
106 switch (regs->regs[REG_RET]) {
107 case -ERESTARTNOHAND:
108 case -ERESTARTSYS:
109 case -ERESTARTNOINTR:
110 /* Decode Syscall # */
111 regs->regs[REG_RET] = regs->syscall_nr;
112 regs->pc -= 4;
113 break;
114
115 case -ERESTART_RESTARTBLOCK:
116 regs->regs[REG_RET] = __NR_restart_syscall;
117 regs->pc -= 4;
118 break;
119 }
120 }
121
122 /* No signal to deliver -- put the saved sigmask back */
123 restore_saved_sigmask();
124 }
125
126 /*
127 * Do a signal return; undo the signal stack.
128 */
129 struct sigframe {
130 struct sigcontext sc;
131 unsigned long extramask[_NSIG_WORDS-1];
132 long long retcode[2];
133 };
134
135 struct rt_sigframe {
136 struct siginfo __user *pinfo;
137 void *puc;
138 struct siginfo info;
139 struct ucontext uc;
140 long long retcode[2];
141 };
142
143 #ifdef CONFIG_SH_FPU
144 static inline int
145 restore_sigcontext_fpu(struct pt_regs *regs, struct sigcontext __user *sc)
146 {
147 int err = 0;
148 int fpvalid;
149
150 err |= __get_user (fpvalid, &sc->sc_fpvalid);
151 conditional_used_math(fpvalid);
152 if (! fpvalid)
153 return err;
154
155 if (current == last_task_used_math) {
156 last_task_used_math = NULL;
157 regs->sr |= SR_FD;
158 }
159
160 err |= __copy_from_user(&current->thread.xstate->hardfpu, &sc->sc_fpregs[0],
161 (sizeof(long long) * 32) + (sizeof(int) * 1));
162
163 return err;
164 }
165
166 static inline int
167 setup_sigcontext_fpu(struct pt_regs *regs, struct sigcontext __user *sc)
168 {
169 int err = 0;
170 int fpvalid;
171
172 fpvalid = !!used_math();
173 err |= __put_user(fpvalid, &sc->sc_fpvalid);
174 if (! fpvalid)
175 return err;
176
177 if (current == last_task_used_math) {
178 enable_fpu();
179 save_fpu(current);
180 disable_fpu();
181 last_task_used_math = NULL;
182 regs->sr |= SR_FD;
183 }
184
185 err |= __copy_to_user(&sc->sc_fpregs[0], &current->thread.xstate->hardfpu,
186 (sizeof(long long) * 32) + (sizeof(int) * 1));
187 clear_used_math();
188
189 return err;
190 }
191 #else
192 static inline int
193 restore_sigcontext_fpu(struct pt_regs *regs, struct sigcontext __user *sc)
194 {
195 return 0;
196 }
197 static inline int
198 setup_sigcontext_fpu(struct pt_regs *regs, struct sigcontext __user *sc)
199 {
200 return 0;
201 }
202 #endif
203
204 static int
205 restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, long long *r2_p)
206 {
207 unsigned int err = 0;
208 unsigned long long current_sr, new_sr;
209 #define SR_MASK 0xffff8cfd
210
211 #define COPY(x) err |= __get_user(regs->x, &sc->sc_##x)
212
213 COPY(regs[0]); COPY(regs[1]); COPY(regs[2]); COPY(regs[3]);
214 COPY(regs[4]); COPY(regs[5]); COPY(regs[6]); COPY(regs[7]);
215 COPY(regs[8]); COPY(regs[9]); COPY(regs[10]); COPY(regs[11]);
216 COPY(regs[12]); COPY(regs[13]); COPY(regs[14]); COPY(regs[15]);
217 COPY(regs[16]); COPY(regs[17]); COPY(regs[18]); COPY(regs[19]);
218 COPY(regs[20]); COPY(regs[21]); COPY(regs[22]); COPY(regs[23]);
219 COPY(regs[24]); COPY(regs[25]); COPY(regs[26]); COPY(regs[27]);
220 COPY(regs[28]); COPY(regs[29]); COPY(regs[30]); COPY(regs[31]);
221 COPY(regs[32]); COPY(regs[33]); COPY(regs[34]); COPY(regs[35]);
222 COPY(regs[36]); COPY(regs[37]); COPY(regs[38]); COPY(regs[39]);
223 COPY(regs[40]); COPY(regs[41]); COPY(regs[42]); COPY(regs[43]);
224 COPY(regs[44]); COPY(regs[45]); COPY(regs[46]); COPY(regs[47]);
225 COPY(regs[48]); COPY(regs[49]); COPY(regs[50]); COPY(regs[51]);
226 COPY(regs[52]); COPY(regs[53]); COPY(regs[54]); COPY(regs[55]);
227 COPY(regs[56]); COPY(regs[57]); COPY(regs[58]); COPY(regs[59]);
228 COPY(regs[60]); COPY(regs[61]); COPY(regs[62]);
229 COPY(tregs[0]); COPY(tregs[1]); COPY(tregs[2]); COPY(tregs[3]);
230 COPY(tregs[4]); COPY(tregs[5]); COPY(tregs[6]); COPY(tregs[7]);
231
232 /* Prevent the signal handler manipulating SR in a way that can
233 crash the kernel. i.e. only allow S, Q, M, PR, SZ, FR to be
234 modified */
235 current_sr = regs->sr;
236 err |= __get_user(new_sr, &sc->sc_sr);
237 regs->sr &= SR_MASK;
238 regs->sr |= (new_sr & ~SR_MASK);
239
240 COPY(pc);
241
242 #undef COPY
243
244 /* Must do this last in case it sets regs->sr.fd (i.e. after rest of sr
245 * has been restored above.) */
246 err |= restore_sigcontext_fpu(regs, sc);
247
248 regs->syscall_nr = -1; /* disable syscall checks */
249 err |= __get_user(*r2_p, &sc->sc_regs[REG_RET]);
250 return err;
251 }
252
253 asmlinkage int sys_sigreturn(unsigned long r2, unsigned long r3,
254 unsigned long r4, unsigned long r5,
255 unsigned long r6, unsigned long r7,
256 struct pt_regs * regs)
257 {
258 struct sigframe __user *frame = (struct sigframe __user *) (long) REF_REG_SP;
259 sigset_t set;
260 long long ret;
261
262 /* Always make any pending restarted system calls return -EINTR */
263 current->restart_block.fn = do_no_restart_syscall;
264
265 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
266 goto badframe;
267
268 if (__get_user(set.sig[0], &frame->sc.oldmask)
269 || (_NSIG_WORDS > 1
270 && __copy_from_user(&set.sig[1], &frame->extramask,
271 sizeof(frame->extramask))))
272 goto badframe;
273
274 set_current_blocked(&set);
275
276 if (restore_sigcontext(regs, &frame->sc, &ret))
277 goto badframe;
278 regs->pc -= 4;
279
280 return (int) ret;
281
282 badframe:
283 force_sig(SIGSEGV, current);
284 return 0;
285 }
286
287 asmlinkage int sys_rt_sigreturn(unsigned long r2, unsigned long r3,
288 unsigned long r4, unsigned long r5,
289 unsigned long r6, unsigned long r7,
290 struct pt_regs * regs)
291 {
292 struct rt_sigframe __user *frame = (struct rt_sigframe __user *) (long) REF_REG_SP;
293 sigset_t set;
294 long long ret;
295
296 /* Always make any pending restarted system calls return -EINTR */
297 current->restart_block.fn = do_no_restart_syscall;
298
299 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
300 goto badframe;
301
302 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
303 goto badframe;
304
305 set_current_blocked(&set);
306
307 if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &ret))
308 goto badframe;
309 regs->pc -= 4;
310
311 if (restore_altstack(&frame->uc.uc_stack))
312 goto badframe;
313
314 return (int) ret;
315
316 badframe:
317 force_sig(SIGSEGV, current);
318 return 0;
319 }
320
321 /*
322 * Set up a signal frame.
323 */
324 static int
325 setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
326 unsigned long mask)
327 {
328 int err = 0;
329
330 /* Do this first, otherwise is this sets sr->fd, that value isn't preserved. */
331 err |= setup_sigcontext_fpu(regs, sc);
332
333 #define COPY(x) err |= __put_user(regs->x, &sc->sc_##x)
334
335 COPY(regs[0]); COPY(regs[1]); COPY(regs[2]); COPY(regs[3]);
336 COPY(regs[4]); COPY(regs[5]); COPY(regs[6]); COPY(regs[7]);
337 COPY(regs[8]); COPY(regs[9]); COPY(regs[10]); COPY(regs[11]);
338 COPY(regs[12]); COPY(regs[13]); COPY(regs[14]); COPY(regs[15]);
339 COPY(regs[16]); COPY(regs[17]); COPY(regs[18]); COPY(regs[19]);
340 COPY(regs[20]); COPY(regs[21]); COPY(regs[22]); COPY(regs[23]);
341 COPY(regs[24]); COPY(regs[25]); COPY(regs[26]); COPY(regs[27]);
342 COPY(regs[28]); COPY(regs[29]); COPY(regs[30]); COPY(regs[31]);
343 COPY(regs[32]); COPY(regs[33]); COPY(regs[34]); COPY(regs[35]);
344 COPY(regs[36]); COPY(regs[37]); COPY(regs[38]); COPY(regs[39]);
345 COPY(regs[40]); COPY(regs[41]); COPY(regs[42]); COPY(regs[43]);
346 COPY(regs[44]); COPY(regs[45]); COPY(regs[46]); COPY(regs[47]);
347 COPY(regs[48]); COPY(regs[49]); COPY(regs[50]); COPY(regs[51]);
348 COPY(regs[52]); COPY(regs[53]); COPY(regs[54]); COPY(regs[55]);
349 COPY(regs[56]); COPY(regs[57]); COPY(regs[58]); COPY(regs[59]);
350 COPY(regs[60]); COPY(regs[61]); COPY(regs[62]);
351 COPY(tregs[0]); COPY(tregs[1]); COPY(tregs[2]); COPY(tregs[3]);
352 COPY(tregs[4]); COPY(tregs[5]); COPY(tregs[6]); COPY(tregs[7]);
353 COPY(sr); COPY(pc);
354
355 #undef COPY
356
357 err |= __put_user(mask, &sc->oldmask);
358
359 return err;
360 }
361
362 /*
363 * Determine which stack to use..
364 */
365 static inline void __user *
366 get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
367 {
368 if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && ! sas_ss_flags(sp))
369 sp = current->sas_ss_sp + current->sas_ss_size;
370
371 return (void __user *)((sp - frame_size) & -8ul);
372 }
373
374 void sa_default_restorer(void); /* See comments below */
375 void sa_default_rt_restorer(void); /* See comments below */
376
377 static int setup_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs)
378 {
379 struct sigframe __user *frame;
380 int err = 0, sig = ksig->sig;
381 int signal;
382
383 frame = get_sigframe(&ksig->ka, regs->regs[REG_SP], sizeof(*frame));
384
385 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
386 return -EFAULT;
387
388 signal = current_thread_info()->exec_domain
389 && current_thread_info()->exec_domain->signal_invmap
390 && sig < 32
391 ? current_thread_info()->exec_domain->signal_invmap[sig]
392 : sig;
393
394 err |= setup_sigcontext(&frame->sc, regs, set->sig[0]);
395
396 /* Give up earlier as i386, in case */
397 if (err)
398 return -EFAULT;
399
400 if (_NSIG_WORDS > 1) {
401 err |= __copy_to_user(frame->extramask, &set->sig[1],
402 sizeof(frame->extramask)); }
403
404 /* Give up earlier as i386, in case */
405 if (err)
406 return -EFAULT;
407
408 /* Set up to return from userspace. If provided, use a stub
409 already in userspace. */
410 if (ksig->ka.sa.sa_flags & SA_RESTORER) {
411 /*
412 * On SH5 all edited pointers are subject to NEFF
413 */
414 DEREF_REG_PR = neff_sign_extend((unsigned long)
415 ksig->ka->sa.sa_restorer | 0x1);
416 } else {
417 /*
418 * Different approach on SH5.
419 * . Endianness independent asm code gets placed in entry.S .
420 * This is limited to four ASM instructions corresponding
421 * to two long longs in size.
422 * . err checking is done on the else branch only
423 * . flush_icache_range() is called upon __put_user() only
424 * . all edited pointers are subject to NEFF
425 * . being code, linker turns ShMedia bit on, always
426 * dereference index -1.
427 */
428 DEREF_REG_PR = neff_sign_extend((unsigned long)
429 frame->retcode | 0x01);
430
431 if (__copy_to_user(frame->retcode,
432 (void *)((unsigned long)sa_default_restorer & (~1)), 16) != 0)
433 return -EFAULT;
434
435 /* Cohere the trampoline with the I-cache. */
436 flush_cache_sigtramp(DEREF_REG_PR-1);
437 }
438
439 /*
440 * Set up registers for signal handler.
441 * All edited pointers are subject to NEFF.
442 */
443 regs->regs[REG_SP] = neff_sign_extend((unsigned long)frame);
444 regs->regs[REG_ARG1] = signal; /* Arg for signal handler */
445
446 /* FIXME:
447 The glibc profiling support for SH-5 needs to be passed a sigcontext
448 so it can retrieve the PC. At some point during 2003 the glibc
449 support was changed to receive the sigcontext through the 2nd
450 argument, but there are still versions of libc.so in use that use
451 the 3rd argument. Until libc.so is stabilised, pass the sigcontext
452 through both 2nd and 3rd arguments.
453 */
454
455 regs->regs[REG_ARG2] = (unsigned long long)(unsigned long)(signed long)&frame->sc;
456 regs->regs[REG_ARG3] = (unsigned long long)(unsigned long)(signed long)&frame->sc;
457
458 regs->pc = neff_sign_extend((unsigned long)ksig->ka.sa.sa_handler);
459
460 set_fs(USER_DS);
461
462 /* Broken %016Lx */
463 pr_debug("SIG deliver (#%d,%s:%d): sp=%p pc=%08Lx%08Lx link=%08Lx%08Lx\n",
464 signal, current->comm, current->pid, frame,
465 regs->pc >> 32, regs->pc & 0xffffffff,
466 DEREF_REG_PR >> 32, DEREF_REG_PR & 0xffffffff);
467
468 return 0;
469 }
470
471 static int setup_rt_frame(struct ksignal *kig, sigset_t *set,
472 struct pt_regs *regs)
473 {
474 struct rt_sigframe __user *frame;
475 int err = 0, sig = ksig->sig;
476 int signal;
477
478 frame = get_sigframe(&ksig->ka, regs->regs[REG_SP], sizeof(*frame));
479
480 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
481 return -EFAULT;
482
483 signal = current_thread_info()->exec_domain
484 && current_thread_info()->exec_domain->signal_invmap
485 && sig < 32
486 ? current_thread_info()->exec_domain->signal_invmap[sig]
487 : sig;
488
489 err |= __put_user(&frame->info, &frame->pinfo);
490 err |= __put_user(&frame->uc, &frame->puc);
491 err |= copy_siginfo_to_user(&frame->info, &ksig->info);
492
493 /* Give up earlier as i386, in case */
494 if (err)
495 return -EFAULT;
496
497 /* Create the ucontext. */
498 err |= __put_user(0, &frame->uc.uc_flags);
499 err |= __put_user(0, &frame->uc.uc_link);
500 err |= __save_altstack(&frame->uc.uc_stack, regs->regs[REG_SP]);
501 err |= setup_sigcontext(&frame->uc.uc_mcontext,
502 regs, set->sig[0]);
503 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
504
505 /* Give up earlier as i386, in case */
506 if (err)
507 return -EFAULT;
508
509 /* Set up to return from userspace. If provided, use a stub
510 already in userspace. */
511 if (ksig->ka.sa.sa_flags & SA_RESTORER) {
512 /*
513 * On SH5 all edited pointers are subject to NEFF
514 */
515 DEREF_REG_PR = neff_sign_extend((unsigned long)
516 ksig->ka.sa.sa_restorer | 0x1);
517 } else {
518 /*
519 * Different approach on SH5.
520 * . Endianness independent asm code gets placed in entry.S .
521 * This is limited to four ASM instructions corresponding
522 * to two long longs in size.
523 * . err checking is done on the else branch only
524 * . flush_icache_range() is called upon __put_user() only
525 * . all edited pointers are subject to NEFF
526 * . being code, linker turns ShMedia bit on, always
527 * dereference index -1.
528 */
529 DEREF_REG_PR = neff_sign_extend((unsigned long)
530 frame->retcode | 0x01);
531
532 if (__copy_to_user(frame->retcode,
533 (void *)((unsigned long)sa_default_rt_restorer & (~1)), 16) != 0)
534 return -EFAULT;
535
536 /* Cohere the trampoline with the I-cache. */
537 flush_icache_range(DEREF_REG_PR-1, DEREF_REG_PR-1+15);
538 }
539
540 /*
541 * Set up registers for signal handler.
542 * All edited pointers are subject to NEFF.
543 */
544 regs->regs[REG_SP] = neff_sign_extend((unsigned long)frame);
545 regs->regs[REG_ARG1] = signal; /* Arg for signal handler */
546 regs->regs[REG_ARG2] = (unsigned long long)(unsigned long)(signed long)&frame->info;
547 regs->regs[REG_ARG3] = (unsigned long long)(unsigned long)(signed long)&frame->uc.uc_mcontext;
548 regs->pc = neff_sign_extend((unsigned long)ksig->ka.sa.sa_handler);
549
550 set_fs(USER_DS);
551
552 pr_debug("SIG deliver (#%d,%s:%d): sp=%p pc=%08Lx%08Lx link=%08Lx%08Lx\n",
553 signal, current->comm, current->pid, frame,
554 regs->pc >> 32, regs->pc & 0xffffffff,
555 DEREF_REG_PR >> 32, DEREF_REG_PR & 0xffffffff);
556
557 return 0;
558 }
559
560 /*
561 * OK, we're invoking a handler
562 */
563 static void
564 handle_signal(struct ksignal *ksig, struct pt_regs *regs)
565 {
566 sigset_t *oldset = sigmask_to_save();
567 int ret;
568
569 /* Set up the stack frame */
570 if (ksig->ka.sa.sa_flags & SA_SIGINFO)
571 ret = setup_rt_frame(ksig, oldset, regs);
572 else
573 ret = setup_frame(ksig, oldset, regs);
574
575 signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP));
576 }
577
578 asmlinkage void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags)
579 {
580 if (thread_info_flags & _TIF_SIGPENDING)
581 do_signal(regs);
582
583 if (thread_info_flags & _TIF_NOTIFY_RESUME) {
584 clear_thread_flag(TIF_NOTIFY_RESUME);
585 tracehook_notify_resume(regs);
586 }
587 }
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