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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/freezer.h>
22#include <linux/ptrace.h>
23#include <linux/unistd.h>
24#include <linux/stddef.h>
25#include <linux/tracehook.h>
26#include <asm/ucontext.h>
27#include <asm/uaccess.h>
28#include <asm/pgtable.h>
29#include <asm/cacheflush.h>
30#include <asm/fpu.h>
31
32#define REG_RET 9
33#define REG_ARG1 2
34#define REG_ARG2 3
35#define REG_ARG3 4
36#define REG_SP 15
37#define REG_PR 18
38#define REF_REG_RET regs->regs[REG_RET]
39#define REF_REG_SP regs->regs[REG_SP]
40#define DEREF_REG_PR regs->regs[REG_PR]
41
42#define DEBUG_SIG 0
43
44static void
45handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
46 struct pt_regs * regs);
47
48static inline void
49handle_syscall_restart(struct pt_regs *regs, struct sigaction *sa)
50{
51 /* If we're not from a syscall, bail out */
52 if (regs->syscall_nr < 0)
53 return;
54
55 /* check for system call restart.. */
56 switch (regs->regs[REG_RET]) {
57 case -ERESTART_RESTARTBLOCK:
58 case -ERESTARTNOHAND:
59 no_system_call_restart:
60 regs->regs[REG_RET] = -EINTR;
61 break;
62
63 case -ERESTARTSYS:
64 if (!(sa->sa_flags & SA_RESTART))
65 goto no_system_call_restart;
66 /* fallthrough */
67 case -ERESTARTNOINTR:
68 /* Decode syscall # */
69 regs->regs[REG_RET] = regs->syscall_nr;
70 regs->pc -= 4;
71 break;
72 }
73}
74
75/*
76 * Note that 'init' is a special process: it doesn't get signals it doesn't
77 * want to handle. Thus you cannot kill init even with a SIGKILL even by
78 * mistake.
79 *
80 * Note that we go through the signals twice: once to check the signals that
81 * the kernel can handle, and then we build all the user-level signal handling
82 * stack-frames in one go after that.
83 */
84static void do_signal(struct pt_regs *regs)
85{
86 siginfo_t info;
87 int signr;
88 struct k_sigaction ka;
89
90 /*
91 * We want the common case to go fast, which
92 * is why we may in certain cases get here from
93 * kernel mode. Just return without doing anything
94 * if so.
95 */
96 if (!user_mode(regs))
97 return;
98
99 signr = get_signal_to_deliver(&info, &ka, regs, 0);
100 if (signr > 0) {
101 handle_syscall_restart(regs, &ka.sa);
102
103 /* Whee! Actually deliver the signal. */
104 handle_signal(signr, &info, &ka, regs);
105 return;
106 }
107
108 /* Did we come from a system call? */
109 if (regs->syscall_nr >= 0) {
110 /* Restart the system call - no handlers present */
111 switch (regs->regs[REG_RET]) {
112 case -ERESTARTNOHAND:
113 case -ERESTARTSYS:
114 case -ERESTARTNOINTR:
115 /* Decode Syscall # */
116 regs->regs[REG_RET] = regs->syscall_nr;
117 regs->pc -= 4;
118 break;
119
120 case -ERESTART_RESTARTBLOCK:
121 regs->regs[REG_RET] = __NR_restart_syscall;
122 regs->pc -= 4;
123 break;
124 }
125 }
126
127 /* No signal to deliver -- put the saved sigmask back */
128 restore_saved_sigmask();
129}
130
131/*
132 * Atomically swap in the new signal mask, and wait for a signal.
133 */
134asmlinkage int
135sys_sigsuspend(old_sigset_t mask)
136{
137 sigset_t blocked;
138 siginitset(&blocked, mask);
139 return sigsuspend(&blocked);
140}
141
142asmlinkage int
143sys_sigaction(int sig, const struct old_sigaction __user *act,
144 struct old_sigaction __user *oact)
145{
146 struct k_sigaction new_ka, old_ka;
147 int ret;
148
149 if (act) {
150 old_sigset_t mask;
151 if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
152 __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
153 __get_user(new_ka.sa.sa_restorer, &act->sa_restorer) ||
154 __get_user(new_ka.sa.sa_flags, &act->sa_flags) ||
155 __get_user(mask, &act->sa_mask))
156 return -EFAULT;
157 siginitset(&new_ka.sa.sa_mask, mask);
158 }
159
160 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
161
162 if (!ret && oact) {
163 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
164 __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
165 __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer) ||
166 __put_user(old_ka.sa.sa_flags, &oact->sa_flags) ||
167 __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask))
168 return -EFAULT;
169 }
170
171 return ret;
172}
173
174asmlinkage int
175sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
176 unsigned long r4, unsigned long r5, unsigned long r6,
177 unsigned long r7,
178 struct pt_regs * regs)
179{
180 return do_sigaltstack(uss, uoss, REF_REG_SP);
181}
182
183/*
184 * Do a signal return; undo the signal stack.
185 */
186struct sigframe {
187 struct sigcontext sc;
188 unsigned long extramask[_NSIG_WORDS-1];
189 long long retcode[2];
190};
191
192struct rt_sigframe {
193 struct siginfo __user *pinfo;
194 void *puc;
195 struct siginfo info;
196 struct ucontext uc;
197 long long retcode[2];
198};
199
200#ifdef CONFIG_SH_FPU
201static inline int
202restore_sigcontext_fpu(struct pt_regs *regs, struct sigcontext __user *sc)
203{
204 int err = 0;
205 int fpvalid;
206
207 err |= __get_user (fpvalid, &sc->sc_fpvalid);
208 conditional_used_math(fpvalid);
209 if (! fpvalid)
210 return err;
211
212 if (current == last_task_used_math) {
213 last_task_used_math = NULL;
214 regs->sr |= SR_FD;
215 }
216
217 err |= __copy_from_user(¤t->thread.xstate->hardfpu, &sc->sc_fpregs[0],
218 (sizeof(long long) * 32) + (sizeof(int) * 1));
219
220 return err;
221}
222
223static inline int
224setup_sigcontext_fpu(struct pt_regs *regs, struct sigcontext __user *sc)
225{
226 int err = 0;
227 int fpvalid;
228
229 fpvalid = !!used_math();
230 err |= __put_user(fpvalid, &sc->sc_fpvalid);
231 if (! fpvalid)
232 return err;
233
234 if (current == last_task_used_math) {
235 enable_fpu();
236 save_fpu(current);
237 disable_fpu();
238 last_task_used_math = NULL;
239 regs->sr |= SR_FD;
240 }
241
242 err |= __copy_to_user(&sc->sc_fpregs[0], ¤t->thread.xstate->hardfpu,
243 (sizeof(long long) * 32) + (sizeof(int) * 1));
244 clear_used_math();
245
246 return err;
247}
248#else
249static inline int
250restore_sigcontext_fpu(struct pt_regs *regs, struct sigcontext __user *sc)
251{
252 return 0;
253}
254static inline int
255setup_sigcontext_fpu(struct pt_regs *regs, struct sigcontext __user *sc)
256{
257 return 0;
258}
259#endif
260
261static int
262restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, long long *r2_p)
263{
264 unsigned int err = 0;
265 unsigned long long current_sr, new_sr;
266#define SR_MASK 0xffff8cfd
267
268#define COPY(x) err |= __get_user(regs->x, &sc->sc_##x)
269
270 COPY(regs[0]); COPY(regs[1]); COPY(regs[2]); COPY(regs[3]);
271 COPY(regs[4]); COPY(regs[5]); COPY(regs[6]); COPY(regs[7]);
272 COPY(regs[8]); COPY(regs[9]); COPY(regs[10]); COPY(regs[11]);
273 COPY(regs[12]); COPY(regs[13]); COPY(regs[14]); COPY(regs[15]);
274 COPY(regs[16]); COPY(regs[17]); COPY(regs[18]); COPY(regs[19]);
275 COPY(regs[20]); COPY(regs[21]); COPY(regs[22]); COPY(regs[23]);
276 COPY(regs[24]); COPY(regs[25]); COPY(regs[26]); COPY(regs[27]);
277 COPY(regs[28]); COPY(regs[29]); COPY(regs[30]); COPY(regs[31]);
278 COPY(regs[32]); COPY(regs[33]); COPY(regs[34]); COPY(regs[35]);
279 COPY(regs[36]); COPY(regs[37]); COPY(regs[38]); COPY(regs[39]);
280 COPY(regs[40]); COPY(regs[41]); COPY(regs[42]); COPY(regs[43]);
281 COPY(regs[44]); COPY(regs[45]); COPY(regs[46]); COPY(regs[47]);
282 COPY(regs[48]); COPY(regs[49]); COPY(regs[50]); COPY(regs[51]);
283 COPY(regs[52]); COPY(regs[53]); COPY(regs[54]); COPY(regs[55]);
284 COPY(regs[56]); COPY(regs[57]); COPY(regs[58]); COPY(regs[59]);
285 COPY(regs[60]); COPY(regs[61]); COPY(regs[62]);
286 COPY(tregs[0]); COPY(tregs[1]); COPY(tregs[2]); COPY(tregs[3]);
287 COPY(tregs[4]); COPY(tregs[5]); COPY(tregs[6]); COPY(tregs[7]);
288
289 /* Prevent the signal handler manipulating SR in a way that can
290 crash the kernel. i.e. only allow S, Q, M, PR, SZ, FR to be
291 modified */
292 current_sr = regs->sr;
293 err |= __get_user(new_sr, &sc->sc_sr);
294 regs->sr &= SR_MASK;
295 regs->sr |= (new_sr & ~SR_MASK);
296
297 COPY(pc);
298
299#undef COPY
300
301 /* Must do this last in case it sets regs->sr.fd (i.e. after rest of sr
302 * has been restored above.) */
303 err |= restore_sigcontext_fpu(regs, sc);
304
305 regs->syscall_nr = -1; /* disable syscall checks */
306 err |= __get_user(*r2_p, &sc->sc_regs[REG_RET]);
307 return err;
308}
309
310asmlinkage int sys_sigreturn(unsigned long r2, unsigned long r3,
311 unsigned long r4, unsigned long r5,
312 unsigned long r6, unsigned long r7,
313 struct pt_regs * regs)
314{
315 struct sigframe __user *frame = (struct sigframe __user *) (long) REF_REG_SP;
316 sigset_t set;
317 long long ret;
318
319 /* Always make any pending restarted system calls return -EINTR */
320 current_thread_info()->restart_block.fn = do_no_restart_syscall;
321
322 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
323 goto badframe;
324
325 if (__get_user(set.sig[0], &frame->sc.oldmask)
326 || (_NSIG_WORDS > 1
327 && __copy_from_user(&set.sig[1], &frame->extramask,
328 sizeof(frame->extramask))))
329 goto badframe;
330
331 set_current_blocked(&set);
332
333 if (restore_sigcontext(regs, &frame->sc, &ret))
334 goto badframe;
335 regs->pc -= 4;
336
337 return (int) ret;
338
339badframe:
340 force_sig(SIGSEGV, current);
341 return 0;
342}
343
344asmlinkage int sys_rt_sigreturn(unsigned long r2, unsigned long r3,
345 unsigned long r4, unsigned long r5,
346 unsigned long r6, unsigned long r7,
347 struct pt_regs * regs)
348{
349 struct rt_sigframe __user *frame = (struct rt_sigframe __user *) (long) REF_REG_SP;
350 sigset_t set;
351 stack_t __user st;
352 long long ret;
353
354 /* Always make any pending restarted system calls return -EINTR */
355 current_thread_info()->restart_block.fn = do_no_restart_syscall;
356
357 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
358 goto badframe;
359
360 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
361 goto badframe;
362
363 set_current_blocked(&set);
364
365 if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &ret))
366 goto badframe;
367 regs->pc -= 4;
368
369 if (__copy_from_user(&st, &frame->uc.uc_stack, sizeof(st)))
370 goto badframe;
371 /* It is more difficult to avoid calling this function than to
372 call it and ignore errors. */
373 do_sigaltstack(&st, NULL, REF_REG_SP);
374
375 return (int) ret;
376
377badframe:
378 force_sig(SIGSEGV, current);
379 return 0;
380}
381
382/*
383 * Set up a signal frame.
384 */
385static int
386setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
387 unsigned long mask)
388{
389 int err = 0;
390
391 /* Do this first, otherwise is this sets sr->fd, that value isn't preserved. */
392 err |= setup_sigcontext_fpu(regs, sc);
393
394#define COPY(x) err |= __put_user(regs->x, &sc->sc_##x)
395
396 COPY(regs[0]); COPY(regs[1]); COPY(regs[2]); COPY(regs[3]);
397 COPY(regs[4]); COPY(regs[5]); COPY(regs[6]); COPY(regs[7]);
398 COPY(regs[8]); COPY(regs[9]); COPY(regs[10]); COPY(regs[11]);
399 COPY(regs[12]); COPY(regs[13]); COPY(regs[14]); COPY(regs[15]);
400 COPY(regs[16]); COPY(regs[17]); COPY(regs[18]); COPY(regs[19]);
401 COPY(regs[20]); COPY(regs[21]); COPY(regs[22]); COPY(regs[23]);
402 COPY(regs[24]); COPY(regs[25]); COPY(regs[26]); COPY(regs[27]);
403 COPY(regs[28]); COPY(regs[29]); COPY(regs[30]); COPY(regs[31]);
404 COPY(regs[32]); COPY(regs[33]); COPY(regs[34]); COPY(regs[35]);
405 COPY(regs[36]); COPY(regs[37]); COPY(regs[38]); COPY(regs[39]);
406 COPY(regs[40]); COPY(regs[41]); COPY(regs[42]); COPY(regs[43]);
407 COPY(regs[44]); COPY(regs[45]); COPY(regs[46]); COPY(regs[47]);
408 COPY(regs[48]); COPY(regs[49]); COPY(regs[50]); COPY(regs[51]);
409 COPY(regs[52]); COPY(regs[53]); COPY(regs[54]); COPY(regs[55]);
410 COPY(regs[56]); COPY(regs[57]); COPY(regs[58]); COPY(regs[59]);
411 COPY(regs[60]); COPY(regs[61]); COPY(regs[62]);
412 COPY(tregs[0]); COPY(tregs[1]); COPY(tregs[2]); COPY(tregs[3]);
413 COPY(tregs[4]); COPY(tregs[5]); COPY(tregs[6]); COPY(tregs[7]);
414 COPY(sr); COPY(pc);
415
416#undef COPY
417
418 err |= __put_user(mask, &sc->oldmask);
419
420 return err;
421}
422
423/*
424 * Determine which stack to use..
425 */
426static inline void __user *
427get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
428{
429 if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && ! sas_ss_flags(sp))
430 sp = current->sas_ss_sp + current->sas_ss_size;
431
432 return (void __user *)((sp - frame_size) & -8ul);
433}
434
435void sa_default_restorer(void); /* See comments below */
436void sa_default_rt_restorer(void); /* See comments below */
437
438static int setup_frame(int sig, struct k_sigaction *ka,
439 sigset_t *set, struct pt_regs *regs)
440{
441 struct sigframe __user *frame;
442 int err = 0;
443 int signal;
444
445 frame = get_sigframe(ka, regs->regs[REG_SP], sizeof(*frame));
446
447 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
448 goto give_sigsegv;
449
450 signal = current_thread_info()->exec_domain
451 && current_thread_info()->exec_domain->signal_invmap
452 && sig < 32
453 ? current_thread_info()->exec_domain->signal_invmap[sig]
454 : sig;
455
456 err |= setup_sigcontext(&frame->sc, regs, set->sig[0]);
457
458 /* Give up earlier as i386, in case */
459 if (err)
460 goto give_sigsegv;
461
462 if (_NSIG_WORDS > 1) {
463 err |= __copy_to_user(frame->extramask, &set->sig[1],
464 sizeof(frame->extramask)); }
465
466 /* Give up earlier as i386, in case */
467 if (err)
468 goto give_sigsegv;
469
470 /* Set up to return from userspace. If provided, use a stub
471 already in userspace. */
472 if (ka->sa.sa_flags & SA_RESTORER) {
473 /*
474 * On SH5 all edited pointers are subject to NEFF
475 */
476 DEREF_REG_PR = neff_sign_extend((unsigned long)
477 ka->sa.sa_restorer | 0x1);
478 } else {
479 /*
480 * Different approach on SH5.
481 * . Endianness independent asm code gets placed in entry.S .
482 * This is limited to four ASM instructions corresponding
483 * to two long longs in size.
484 * . err checking is done on the else branch only
485 * . flush_icache_range() is called upon __put_user() only
486 * . all edited pointers are subject to NEFF
487 * . being code, linker turns ShMedia bit on, always
488 * dereference index -1.
489 */
490 DEREF_REG_PR = neff_sign_extend((unsigned long)
491 frame->retcode | 0x01);
492
493 if (__copy_to_user(frame->retcode,
494 (void *)((unsigned long)sa_default_restorer & (~1)), 16) != 0)
495 goto give_sigsegv;
496
497 /* Cohere the trampoline with the I-cache. */
498 flush_cache_sigtramp(DEREF_REG_PR-1);
499 }
500
501 /*
502 * Set up registers for signal handler.
503 * All edited pointers are subject to NEFF.
504 */
505 regs->regs[REG_SP] = neff_sign_extend((unsigned long)frame);
506 regs->regs[REG_ARG1] = signal; /* Arg for signal handler */
507
508 /* FIXME:
509 The glibc profiling support for SH-5 needs to be passed a sigcontext
510 so it can retrieve the PC. At some point during 2003 the glibc
511 support was changed to receive the sigcontext through the 2nd
512 argument, but there are still versions of libc.so in use that use
513 the 3rd argument. Until libc.so is stabilised, pass the sigcontext
514 through both 2nd and 3rd arguments.
515 */
516
517 regs->regs[REG_ARG2] = (unsigned long long)(unsigned long)(signed long)&frame->sc;
518 regs->regs[REG_ARG3] = (unsigned long long)(unsigned long)(signed long)&frame->sc;
519
520 regs->pc = neff_sign_extend((unsigned long)ka->sa.sa_handler);
521
522 set_fs(USER_DS);
523
524 /* Broken %016Lx */
525 pr_debug("SIG deliver (#%d,%s:%d): sp=%p pc=%08Lx%08Lx link=%08Lx%08Lx\n",
526 signal, current->comm, current->pid, frame,
527 regs->pc >> 32, regs->pc & 0xffffffff,
528 DEREF_REG_PR >> 32, DEREF_REG_PR & 0xffffffff);
529
530 return 0;
531
532give_sigsegv:
533 force_sigsegv(sig, current);
534 return -EFAULT;
535}
536
537static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
538 sigset_t *set, struct pt_regs *regs)
539{
540 struct rt_sigframe __user *frame;
541 int err = 0;
542 int signal;
543
544 frame = get_sigframe(ka, regs->regs[REG_SP], sizeof(*frame));
545
546 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
547 goto give_sigsegv;
548
549 signal = current_thread_info()->exec_domain
550 && current_thread_info()->exec_domain->signal_invmap
551 && sig < 32
552 ? current_thread_info()->exec_domain->signal_invmap[sig]
553 : sig;
554
555 err |= __put_user(&frame->info, &frame->pinfo);
556 err |= __put_user(&frame->uc, &frame->puc);
557 err |= copy_siginfo_to_user(&frame->info, info);
558
559 /* Give up earlier as i386, in case */
560 if (err)
561 goto give_sigsegv;
562
563 /* Create the ucontext. */
564 err |= __put_user(0, &frame->uc.uc_flags);
565 err |= __put_user(0, &frame->uc.uc_link);
566 err |= __put_user((void *)current->sas_ss_sp,
567 &frame->uc.uc_stack.ss_sp);
568 err |= __put_user(sas_ss_flags(regs->regs[REG_SP]),
569 &frame->uc.uc_stack.ss_flags);
570 err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
571 err |= setup_sigcontext(&frame->uc.uc_mcontext,
572 regs, set->sig[0]);
573 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
574
575 /* Give up earlier as i386, in case */
576 if (err)
577 goto give_sigsegv;
578
579 /* Set up to return from userspace. If provided, use a stub
580 already in userspace. */
581 if (ka->sa.sa_flags & SA_RESTORER) {
582 /*
583 * On SH5 all edited pointers are subject to NEFF
584 */
585 DEREF_REG_PR = neff_sign_extend((unsigned long)
586 ka->sa.sa_restorer | 0x1);
587 } else {
588 /*
589 * Different approach on SH5.
590 * . Endianness independent asm code gets placed in entry.S .
591 * This is limited to four ASM instructions corresponding
592 * to two long longs in size.
593 * . err checking is done on the else branch only
594 * . flush_icache_range() is called upon __put_user() only
595 * . all edited pointers are subject to NEFF
596 * . being code, linker turns ShMedia bit on, always
597 * dereference index -1.
598 */
599 DEREF_REG_PR = neff_sign_extend((unsigned long)
600 frame->retcode | 0x01);
601
602 if (__copy_to_user(frame->retcode,
603 (void *)((unsigned long)sa_default_rt_restorer & (~1)), 16) != 0)
604 goto give_sigsegv;
605
606 /* Cohere the trampoline with the I-cache. */
607 flush_icache_range(DEREF_REG_PR-1, DEREF_REG_PR-1+15);
608 }
609
610 /*
611 * Set up registers for signal handler.
612 * All edited pointers are subject to NEFF.
613 */
614 regs->regs[REG_SP] = neff_sign_extend((unsigned long)frame);
615 regs->regs[REG_ARG1] = signal; /* Arg for signal handler */
616 regs->regs[REG_ARG2] = (unsigned long long)(unsigned long)(signed long)&frame->info;
617 regs->regs[REG_ARG3] = (unsigned long long)(unsigned long)(signed long)&frame->uc.uc_mcontext;
618 regs->pc = neff_sign_extend((unsigned long)ka->sa.sa_handler);
619
620 set_fs(USER_DS);
621
622 pr_debug("SIG deliver (#%d,%s:%d): sp=%p pc=%08Lx%08Lx link=%08Lx%08Lx\n",
623 signal, current->comm, current->pid, frame,
624 regs->pc >> 32, regs->pc & 0xffffffff,
625 DEREF_REG_PR >> 32, DEREF_REG_PR & 0xffffffff);
626
627 return 0;
628
629give_sigsegv:
630 force_sigsegv(sig, current);
631 return -EFAULT;
632}
633
634/*
635 * OK, we're invoking a handler
636 */
637static void
638handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
639 struct pt_regs * regs)
640{
641 sigset_t *oldset = sigmask_to_save();
642 int ret;
643
644 /* Set up the stack frame */
645 if (ka->sa.sa_flags & SA_SIGINFO)
646 ret = setup_rt_frame(sig, ka, info, oldset, regs);
647 else
648 ret = setup_frame(sig, ka, oldset, regs);
649
650 if (ret)
651 return;
652
653 signal_delivered(sig, info, ka, regs,
654 test_thread_flag(TIF_SINGLESTEP));
655}
656
657asmlinkage void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags)
658{
659 if (thread_info_flags & _TIF_SIGPENDING)
660 do_signal(regs);
661
662 if (thread_info_flags & _TIF_NOTIFY_RESUME) {
663 clear_thread_flag(TIF_NOTIFY_RESUME);
664 tracehook_notify_resume(regs);
665 }
666}
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
43static void
44handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
45 struct pt_regs * regs);
46
47static inline void
48handle_syscall_restart(struct pt_regs *regs, struct sigaction *sa)
49{
50 /* If we're not from a syscall, bail out */
51 if (regs->syscall_nr < 0)
52 return;
53
54 /* check for system call restart.. */
55 switch (regs->regs[REG_RET]) {
56 case -ERESTART_RESTARTBLOCK:
57 case -ERESTARTNOHAND:
58 no_system_call_restart:
59 regs->regs[REG_RET] = -EINTR;
60 break;
61
62 case -ERESTARTSYS:
63 if (!(sa->sa_flags & SA_RESTART))
64 goto no_system_call_restart;
65 /* fallthrough */
66 case -ERESTARTNOINTR:
67 /* Decode syscall # */
68 regs->regs[REG_RET] = regs->syscall_nr;
69 regs->pc -= 4;
70 break;
71 }
72}
73
74/*
75 * Note that 'init' is a special process: it doesn't get signals it doesn't
76 * want to handle. Thus you cannot kill init even with a SIGKILL even by
77 * mistake.
78 *
79 * Note that we go through the signals twice: once to check the signals that
80 * the kernel can handle, and then we build all the user-level signal handling
81 * stack-frames in one go after that.
82 */
83static void do_signal(struct pt_regs *regs)
84{
85 siginfo_t info;
86 int signr;
87 struct k_sigaction ka;
88
89 /*
90 * We want the common case to go fast, which
91 * is why we may in certain cases get here from
92 * kernel mode. Just return without doing anything
93 * if so.
94 */
95 if (!user_mode(regs))
96 return;
97
98 signr = get_signal_to_deliver(&info, &ka, regs, 0);
99 if (signr > 0) {
100 handle_syscall_restart(regs, &ka.sa);
101
102 /* Whee! Actually deliver the signal. */
103 handle_signal(signr, &info, &ka, regs);
104 return;
105 }
106
107 /* Did we come from a system call? */
108 if (regs->syscall_nr >= 0) {
109 /* Restart the system call - no handlers present */
110 switch (regs->regs[REG_RET]) {
111 case -ERESTARTNOHAND:
112 case -ERESTARTSYS:
113 case -ERESTARTNOINTR:
114 /* Decode Syscall # */
115 regs->regs[REG_RET] = regs->syscall_nr;
116 regs->pc -= 4;
117 break;
118
119 case -ERESTART_RESTARTBLOCK:
120 regs->regs[REG_RET] = __NR_restart_syscall;
121 regs->pc -= 4;
122 break;
123 }
124 }
125
126 /* No signal to deliver -- put the saved sigmask back */
127 restore_saved_sigmask();
128}
129
130/*
131 * Do a signal return; undo the signal stack.
132 */
133struct sigframe {
134 struct sigcontext sc;
135 unsigned long extramask[_NSIG_WORDS-1];
136 long long retcode[2];
137};
138
139struct rt_sigframe {
140 struct siginfo __user *pinfo;
141 void *puc;
142 struct siginfo info;
143 struct ucontext uc;
144 long long retcode[2];
145};
146
147#ifdef CONFIG_SH_FPU
148static inline int
149restore_sigcontext_fpu(struct pt_regs *regs, struct sigcontext __user *sc)
150{
151 int err = 0;
152 int fpvalid;
153
154 err |= __get_user (fpvalid, &sc->sc_fpvalid);
155 conditional_used_math(fpvalid);
156 if (! fpvalid)
157 return err;
158
159 if (current == last_task_used_math) {
160 last_task_used_math = NULL;
161 regs->sr |= SR_FD;
162 }
163
164 err |= __copy_from_user(¤t->thread.xstate->hardfpu, &sc->sc_fpregs[0],
165 (sizeof(long long) * 32) + (sizeof(int) * 1));
166
167 return err;
168}
169
170static inline int
171setup_sigcontext_fpu(struct pt_regs *regs, struct sigcontext __user *sc)
172{
173 int err = 0;
174 int fpvalid;
175
176 fpvalid = !!used_math();
177 err |= __put_user(fpvalid, &sc->sc_fpvalid);
178 if (! fpvalid)
179 return err;
180
181 if (current == last_task_used_math) {
182 enable_fpu();
183 save_fpu(current);
184 disable_fpu();
185 last_task_used_math = NULL;
186 regs->sr |= SR_FD;
187 }
188
189 err |= __copy_to_user(&sc->sc_fpregs[0], ¤t->thread.xstate->hardfpu,
190 (sizeof(long long) * 32) + (sizeof(int) * 1));
191 clear_used_math();
192
193 return err;
194}
195#else
196static inline int
197restore_sigcontext_fpu(struct pt_regs *regs, struct sigcontext __user *sc)
198{
199 return 0;
200}
201static inline int
202setup_sigcontext_fpu(struct pt_regs *regs, struct sigcontext __user *sc)
203{
204 return 0;
205}
206#endif
207
208static int
209restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, long long *r2_p)
210{
211 unsigned int err = 0;
212 unsigned long long current_sr, new_sr;
213#define SR_MASK 0xffff8cfd
214
215#define COPY(x) err |= __get_user(regs->x, &sc->sc_##x)
216
217 COPY(regs[0]); COPY(regs[1]); COPY(regs[2]); COPY(regs[3]);
218 COPY(regs[4]); COPY(regs[5]); COPY(regs[6]); COPY(regs[7]);
219 COPY(regs[8]); COPY(regs[9]); COPY(regs[10]); COPY(regs[11]);
220 COPY(regs[12]); COPY(regs[13]); COPY(regs[14]); COPY(regs[15]);
221 COPY(regs[16]); COPY(regs[17]); COPY(regs[18]); COPY(regs[19]);
222 COPY(regs[20]); COPY(regs[21]); COPY(regs[22]); COPY(regs[23]);
223 COPY(regs[24]); COPY(regs[25]); COPY(regs[26]); COPY(regs[27]);
224 COPY(regs[28]); COPY(regs[29]); COPY(regs[30]); COPY(regs[31]);
225 COPY(regs[32]); COPY(regs[33]); COPY(regs[34]); COPY(regs[35]);
226 COPY(regs[36]); COPY(regs[37]); COPY(regs[38]); COPY(regs[39]);
227 COPY(regs[40]); COPY(regs[41]); COPY(regs[42]); COPY(regs[43]);
228 COPY(regs[44]); COPY(regs[45]); COPY(regs[46]); COPY(regs[47]);
229 COPY(regs[48]); COPY(regs[49]); COPY(regs[50]); COPY(regs[51]);
230 COPY(regs[52]); COPY(regs[53]); COPY(regs[54]); COPY(regs[55]);
231 COPY(regs[56]); COPY(regs[57]); COPY(regs[58]); COPY(regs[59]);
232 COPY(regs[60]); COPY(regs[61]); COPY(regs[62]);
233 COPY(tregs[0]); COPY(tregs[1]); COPY(tregs[2]); COPY(tregs[3]);
234 COPY(tregs[4]); COPY(tregs[5]); COPY(tregs[6]); COPY(tregs[7]);
235
236 /* Prevent the signal handler manipulating SR in a way that can
237 crash the kernel. i.e. only allow S, Q, M, PR, SZ, FR to be
238 modified */
239 current_sr = regs->sr;
240 err |= __get_user(new_sr, &sc->sc_sr);
241 regs->sr &= SR_MASK;
242 regs->sr |= (new_sr & ~SR_MASK);
243
244 COPY(pc);
245
246#undef COPY
247
248 /* Must do this last in case it sets regs->sr.fd (i.e. after rest of sr
249 * has been restored above.) */
250 err |= restore_sigcontext_fpu(regs, sc);
251
252 regs->syscall_nr = -1; /* disable syscall checks */
253 err |= __get_user(*r2_p, &sc->sc_regs[REG_RET]);
254 return err;
255}
256
257asmlinkage int sys_sigreturn(unsigned long r2, unsigned long r3,
258 unsigned long r4, unsigned long r5,
259 unsigned long r6, unsigned long r7,
260 struct pt_regs * regs)
261{
262 struct sigframe __user *frame = (struct sigframe __user *) (long) REF_REG_SP;
263 sigset_t set;
264 long long ret;
265
266 /* Always make any pending restarted system calls return -EINTR */
267 current_thread_info()->restart_block.fn = do_no_restart_syscall;
268
269 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
270 goto badframe;
271
272 if (__get_user(set.sig[0], &frame->sc.oldmask)
273 || (_NSIG_WORDS > 1
274 && __copy_from_user(&set.sig[1], &frame->extramask,
275 sizeof(frame->extramask))))
276 goto badframe;
277
278 set_current_blocked(&set);
279
280 if (restore_sigcontext(regs, &frame->sc, &ret))
281 goto badframe;
282 regs->pc -= 4;
283
284 return (int) ret;
285
286badframe:
287 force_sig(SIGSEGV, current);
288 return 0;
289}
290
291asmlinkage int sys_rt_sigreturn(unsigned long r2, unsigned long r3,
292 unsigned long r4, unsigned long r5,
293 unsigned long r6, unsigned long r7,
294 struct pt_regs * regs)
295{
296 struct rt_sigframe __user *frame = (struct rt_sigframe __user *) (long) REF_REG_SP;
297 sigset_t set;
298 long long ret;
299
300 /* Always make any pending restarted system calls return -EINTR */
301 current_thread_info()->restart_block.fn = do_no_restart_syscall;
302
303 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
304 goto badframe;
305
306 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
307 goto badframe;
308
309 set_current_blocked(&set);
310
311 if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &ret))
312 goto badframe;
313 regs->pc -= 4;
314
315 if (restore_altstack(&frame->uc.uc_stack))
316 goto badframe;
317
318 return (int) ret;
319
320badframe:
321 force_sig(SIGSEGV, current);
322 return 0;
323}
324
325/*
326 * Set up a signal frame.
327 */
328static int
329setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
330 unsigned long mask)
331{
332 int err = 0;
333
334 /* Do this first, otherwise is this sets sr->fd, that value isn't preserved. */
335 err |= setup_sigcontext_fpu(regs, sc);
336
337#define COPY(x) err |= __put_user(regs->x, &sc->sc_##x)
338
339 COPY(regs[0]); COPY(regs[1]); COPY(regs[2]); COPY(regs[3]);
340 COPY(regs[4]); COPY(regs[5]); COPY(regs[6]); COPY(regs[7]);
341 COPY(regs[8]); COPY(regs[9]); COPY(regs[10]); COPY(regs[11]);
342 COPY(regs[12]); COPY(regs[13]); COPY(regs[14]); COPY(regs[15]);
343 COPY(regs[16]); COPY(regs[17]); COPY(regs[18]); COPY(regs[19]);
344 COPY(regs[20]); COPY(regs[21]); COPY(regs[22]); COPY(regs[23]);
345 COPY(regs[24]); COPY(regs[25]); COPY(regs[26]); COPY(regs[27]);
346 COPY(regs[28]); COPY(regs[29]); COPY(regs[30]); COPY(regs[31]);
347 COPY(regs[32]); COPY(regs[33]); COPY(regs[34]); COPY(regs[35]);
348 COPY(regs[36]); COPY(regs[37]); COPY(regs[38]); COPY(regs[39]);
349 COPY(regs[40]); COPY(regs[41]); COPY(regs[42]); COPY(regs[43]);
350 COPY(regs[44]); COPY(regs[45]); COPY(regs[46]); COPY(regs[47]);
351 COPY(regs[48]); COPY(regs[49]); COPY(regs[50]); COPY(regs[51]);
352 COPY(regs[52]); COPY(regs[53]); COPY(regs[54]); COPY(regs[55]);
353 COPY(regs[56]); COPY(regs[57]); COPY(regs[58]); COPY(regs[59]);
354 COPY(regs[60]); COPY(regs[61]); COPY(regs[62]);
355 COPY(tregs[0]); COPY(tregs[1]); COPY(tregs[2]); COPY(tregs[3]);
356 COPY(tregs[4]); COPY(tregs[5]); COPY(tregs[6]); COPY(tregs[7]);
357 COPY(sr); COPY(pc);
358
359#undef COPY
360
361 err |= __put_user(mask, &sc->oldmask);
362
363 return err;
364}
365
366/*
367 * Determine which stack to use..
368 */
369static inline void __user *
370get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
371{
372 if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && ! sas_ss_flags(sp))
373 sp = current->sas_ss_sp + current->sas_ss_size;
374
375 return (void __user *)((sp - frame_size) & -8ul);
376}
377
378void sa_default_restorer(void); /* See comments below */
379void sa_default_rt_restorer(void); /* See comments below */
380
381static int setup_frame(int sig, struct k_sigaction *ka,
382 sigset_t *set, struct pt_regs *regs)
383{
384 struct sigframe __user *frame;
385 int err = 0;
386 int signal;
387
388 frame = get_sigframe(ka, regs->regs[REG_SP], sizeof(*frame));
389
390 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
391 goto give_sigsegv;
392
393 signal = current_thread_info()->exec_domain
394 && current_thread_info()->exec_domain->signal_invmap
395 && sig < 32
396 ? current_thread_info()->exec_domain->signal_invmap[sig]
397 : sig;
398
399 err |= setup_sigcontext(&frame->sc, regs, set->sig[0]);
400
401 /* Give up earlier as i386, in case */
402 if (err)
403 goto give_sigsegv;
404
405 if (_NSIG_WORDS > 1) {
406 err |= __copy_to_user(frame->extramask, &set->sig[1],
407 sizeof(frame->extramask)); }
408
409 /* Give up earlier as i386, in case */
410 if (err)
411 goto give_sigsegv;
412
413 /* Set up to return from userspace. If provided, use a stub
414 already in userspace. */
415 if (ka->sa.sa_flags & SA_RESTORER) {
416 /*
417 * On SH5 all edited pointers are subject to NEFF
418 */
419 DEREF_REG_PR = neff_sign_extend((unsigned long)
420 ka->sa.sa_restorer | 0x1);
421 } else {
422 /*
423 * Different approach on SH5.
424 * . Endianness independent asm code gets placed in entry.S .
425 * This is limited to four ASM instructions corresponding
426 * to two long longs in size.
427 * . err checking is done on the else branch only
428 * . flush_icache_range() is called upon __put_user() only
429 * . all edited pointers are subject to NEFF
430 * . being code, linker turns ShMedia bit on, always
431 * dereference index -1.
432 */
433 DEREF_REG_PR = neff_sign_extend((unsigned long)
434 frame->retcode | 0x01);
435
436 if (__copy_to_user(frame->retcode,
437 (void *)((unsigned long)sa_default_restorer & (~1)), 16) != 0)
438 goto give_sigsegv;
439
440 /* Cohere the trampoline with the I-cache. */
441 flush_cache_sigtramp(DEREF_REG_PR-1);
442 }
443
444 /*
445 * Set up registers for signal handler.
446 * All edited pointers are subject to NEFF.
447 */
448 regs->regs[REG_SP] = neff_sign_extend((unsigned long)frame);
449 regs->regs[REG_ARG1] = signal; /* Arg for signal handler */
450
451 /* FIXME:
452 The glibc profiling support for SH-5 needs to be passed a sigcontext
453 so it can retrieve the PC. At some point during 2003 the glibc
454 support was changed to receive the sigcontext through the 2nd
455 argument, but there are still versions of libc.so in use that use
456 the 3rd argument. Until libc.so is stabilised, pass the sigcontext
457 through both 2nd and 3rd arguments.
458 */
459
460 regs->regs[REG_ARG2] = (unsigned long long)(unsigned long)(signed long)&frame->sc;
461 regs->regs[REG_ARG3] = (unsigned long long)(unsigned long)(signed long)&frame->sc;
462
463 regs->pc = neff_sign_extend((unsigned long)ka->sa.sa_handler);
464
465 set_fs(USER_DS);
466
467 /* Broken %016Lx */
468 pr_debug("SIG deliver (#%d,%s:%d): sp=%p pc=%08Lx%08Lx link=%08Lx%08Lx\n",
469 signal, current->comm, current->pid, frame,
470 regs->pc >> 32, regs->pc & 0xffffffff,
471 DEREF_REG_PR >> 32, DEREF_REG_PR & 0xffffffff);
472
473 return 0;
474
475give_sigsegv:
476 force_sigsegv(sig, current);
477 return -EFAULT;
478}
479
480static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
481 sigset_t *set, struct pt_regs *regs)
482{
483 struct rt_sigframe __user *frame;
484 int err = 0;
485 int signal;
486
487 frame = get_sigframe(ka, regs->regs[REG_SP], sizeof(*frame));
488
489 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
490 goto give_sigsegv;
491
492 signal = current_thread_info()->exec_domain
493 && current_thread_info()->exec_domain->signal_invmap
494 && sig < 32
495 ? current_thread_info()->exec_domain->signal_invmap[sig]
496 : sig;
497
498 err |= __put_user(&frame->info, &frame->pinfo);
499 err |= __put_user(&frame->uc, &frame->puc);
500 err |= copy_siginfo_to_user(&frame->info, info);
501
502 /* Give up earlier as i386, in case */
503 if (err)
504 goto give_sigsegv;
505
506 /* Create the ucontext. */
507 err |= __put_user(0, &frame->uc.uc_flags);
508 err |= __put_user(0, &frame->uc.uc_link);
509 err |= __save_altstack(&frame->uc.uc_stack, regs->regs[REG_SP]);
510 err |= setup_sigcontext(&frame->uc.uc_mcontext,
511 regs, set->sig[0]);
512 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
513
514 /* Give up earlier as i386, in case */
515 if (err)
516 goto give_sigsegv;
517
518 /* Set up to return from userspace. If provided, use a stub
519 already in userspace. */
520 if (ka->sa.sa_flags & SA_RESTORER) {
521 /*
522 * On SH5 all edited pointers are subject to NEFF
523 */
524 DEREF_REG_PR = neff_sign_extend((unsigned long)
525 ka->sa.sa_restorer | 0x1);
526 } else {
527 /*
528 * Different approach on SH5.
529 * . Endianness independent asm code gets placed in entry.S .
530 * This is limited to four ASM instructions corresponding
531 * to two long longs in size.
532 * . err checking is done on the else branch only
533 * . flush_icache_range() is called upon __put_user() only
534 * . all edited pointers are subject to NEFF
535 * . being code, linker turns ShMedia bit on, always
536 * dereference index -1.
537 */
538 DEREF_REG_PR = neff_sign_extend((unsigned long)
539 frame->retcode | 0x01);
540
541 if (__copy_to_user(frame->retcode,
542 (void *)((unsigned long)sa_default_rt_restorer & (~1)), 16) != 0)
543 goto give_sigsegv;
544
545 /* Cohere the trampoline with the I-cache. */
546 flush_icache_range(DEREF_REG_PR-1, DEREF_REG_PR-1+15);
547 }
548
549 /*
550 * Set up registers for signal handler.
551 * All edited pointers are subject to NEFF.
552 */
553 regs->regs[REG_SP] = neff_sign_extend((unsigned long)frame);
554 regs->regs[REG_ARG1] = signal; /* Arg for signal handler */
555 regs->regs[REG_ARG2] = (unsigned long long)(unsigned long)(signed long)&frame->info;
556 regs->regs[REG_ARG3] = (unsigned long long)(unsigned long)(signed long)&frame->uc.uc_mcontext;
557 regs->pc = neff_sign_extend((unsigned long)ka->sa.sa_handler);
558
559 set_fs(USER_DS);
560
561 pr_debug("SIG deliver (#%d,%s:%d): sp=%p pc=%08Lx%08Lx link=%08Lx%08Lx\n",
562 signal, current->comm, current->pid, frame,
563 regs->pc >> 32, regs->pc & 0xffffffff,
564 DEREF_REG_PR >> 32, DEREF_REG_PR & 0xffffffff);
565
566 return 0;
567
568give_sigsegv:
569 force_sigsegv(sig, current);
570 return -EFAULT;
571}
572
573/*
574 * OK, we're invoking a handler
575 */
576static void
577handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
578 struct pt_regs * regs)
579{
580 sigset_t *oldset = sigmask_to_save();
581 int ret;
582
583 /* Set up the stack frame */
584 if (ka->sa.sa_flags & SA_SIGINFO)
585 ret = setup_rt_frame(sig, ka, info, oldset, regs);
586 else
587 ret = setup_frame(sig, ka, oldset, regs);
588
589 if (ret)
590 return;
591
592 signal_delivered(sig, info, ka, regs,
593 test_thread_flag(TIF_SINGLESTEP));
594}
595
596asmlinkage void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags)
597{
598 if (thread_info_flags & _TIF_SIGPENDING)
599 do_signal(regs);
600
601 if (thread_info_flags & _TIF_NOTIFY_RESUME) {
602 clear_thread_flag(TIF_NOTIFY_RESUME);
603 tracehook_notify_resume(regs);
604 }
605}