Loading...
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// SPDX-License-Identifier: GPL-2.0
2/*
3 * arch/sh/kernel/signal_64.c
4 *
5 * Copyright (C) 2000, 2001 Paolo Alberelli
6 * Copyright (C) 2003 - 2008 Paul Mundt
7 * Copyright (C) 2004 Richard Curnow
8 */
9#include <linux/rwsem.h>
10#include <linux/sched.h>
11#include <linux/mm.h>
12#include <linux/smp.h>
13#include <linux/kernel.h>
14#include <linux/signal.h>
15#include <linux/errno.h>
16#include <linux/wait.h>
17#include <linux/personality.h>
18#include <linux/ptrace.h>
19#include <linux/unistd.h>
20#include <linux/stddef.h>
21#include <linux/tracehook.h>
22#include <asm/ucontext.h>
23#include <linux/uaccess.h>
24#include <asm/pgtable.h>
25#include <asm/cacheflush.h>
26#include <asm/fpu.h>
27
28#define REG_RET 9
29#define REG_ARG1 2
30#define REG_ARG2 3
31#define REG_ARG3 4
32#define REG_SP 15
33#define REG_PR 18
34#define REF_REG_RET regs->regs[REG_RET]
35#define REF_REG_SP regs->regs[REG_SP]
36#define DEREF_REG_PR regs->regs[REG_PR]
37
38#define DEBUG_SIG 0
39
40static void
41handle_signal(struct ksignal *ksig, struct pt_regs *regs);
42
43static inline void
44handle_syscall_restart(struct pt_regs *regs, struct sigaction *sa)
45{
46 /* If we're not from a syscall, bail out */
47 if (regs->syscall_nr < 0)
48 return;
49
50 /* check for system call restart.. */
51 switch (regs->regs[REG_RET]) {
52 case -ERESTART_RESTARTBLOCK:
53 case -ERESTARTNOHAND:
54 no_system_call_restart:
55 regs->regs[REG_RET] = -EINTR;
56 break;
57
58 case -ERESTARTSYS:
59 if (!(sa->sa_flags & SA_RESTART))
60 goto no_system_call_restart;
61 /* fallthrough */
62 case -ERESTARTNOINTR:
63 /* Decode syscall # */
64 regs->regs[REG_RET] = regs->syscall_nr;
65 regs->pc -= 4;
66 break;
67 }
68}
69
70/*
71 * Note that 'init' is a special process: it doesn't get signals it doesn't
72 * want to handle. Thus you cannot kill init even with a SIGKILL even by
73 * mistake.
74 *
75 * Note that we go through the signals twice: once to check the signals that
76 * the kernel can handle, and then we build all the user-level signal handling
77 * stack-frames in one go after that.
78 */
79static void do_signal(struct pt_regs *regs)
80{
81 struct ksignal ksig;
82
83 /*
84 * We want the common case to go fast, which
85 * is why we may in certain cases get here from
86 * kernel mode. Just return without doing anything
87 * if so.
88 */
89 if (!user_mode(regs))
90 return;
91
92 if (get_signal(&ksig)) {
93 handle_syscall_restart(regs, &ksig.ka.sa);
94
95 /* Whee! Actually deliver the signal. */
96 handle_signal(&ksig, regs);
97 return;
98 }
99
100 /* Did we come from a system call? */
101 if (regs->syscall_nr >= 0) {
102 /* Restart the system call - no handlers present */
103 switch (regs->regs[REG_RET]) {
104 case -ERESTARTNOHAND:
105 case -ERESTARTSYS:
106 case -ERESTARTNOINTR:
107 /* Decode Syscall # */
108 regs->regs[REG_RET] = regs->syscall_nr;
109 regs->pc -= 4;
110 break;
111
112 case -ERESTART_RESTARTBLOCK:
113 regs->regs[REG_RET] = __NR_restart_syscall;
114 regs->pc -= 4;
115 break;
116 }
117 }
118
119 /* No signal to deliver -- put the saved sigmask back */
120 restore_saved_sigmask();
121}
122
123/*
124 * Do a signal return; undo the signal stack.
125 */
126struct sigframe {
127 struct sigcontext sc;
128 unsigned long extramask[_NSIG_WORDS-1];
129 long long retcode[2];
130};
131
132struct rt_sigframe {
133 struct siginfo __user *pinfo;
134 void *puc;
135 struct siginfo info;
136 struct ucontext uc;
137 long long retcode[2];
138};
139
140#ifdef CONFIG_SH_FPU
141static inline int
142restore_sigcontext_fpu(struct pt_regs *regs, struct sigcontext __user *sc)
143{
144 int err = 0;
145 int fpvalid;
146
147 err |= __get_user (fpvalid, &sc->sc_fpvalid);
148 conditional_used_math(fpvalid);
149 if (! fpvalid)
150 return err;
151
152 if (current == last_task_used_math) {
153 last_task_used_math = NULL;
154 regs->sr |= SR_FD;
155 }
156
157 err |= __copy_from_user(¤t->thread.xstate->hardfpu, &sc->sc_fpregs[0],
158 (sizeof(long long) * 32) + (sizeof(int) * 1));
159
160 return err;
161}
162
163static inline int
164setup_sigcontext_fpu(struct pt_regs *regs, struct sigcontext __user *sc)
165{
166 int err = 0;
167 int fpvalid;
168
169 fpvalid = !!used_math();
170 err |= __put_user(fpvalid, &sc->sc_fpvalid);
171 if (! fpvalid)
172 return err;
173
174 if (current == last_task_used_math) {
175 enable_fpu();
176 save_fpu(current);
177 disable_fpu();
178 last_task_used_math = NULL;
179 regs->sr |= SR_FD;
180 }
181
182 err |= __copy_to_user(&sc->sc_fpregs[0], ¤t->thread.xstate->hardfpu,
183 (sizeof(long long) * 32) + (sizeof(int) * 1));
184 clear_used_math();
185
186 return err;
187}
188#else
189static inline int
190restore_sigcontext_fpu(struct pt_regs *regs, struct sigcontext __user *sc)
191{
192 return 0;
193}
194static inline int
195setup_sigcontext_fpu(struct pt_regs *regs, struct sigcontext __user *sc)
196{
197 return 0;
198}
199#endif
200
201static int
202restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, long long *r2_p)
203{
204 unsigned int err = 0;
205 unsigned long long current_sr, new_sr;
206#define SR_MASK 0xffff8cfd
207
208#define COPY(x) err |= __get_user(regs->x, &sc->sc_##x)
209
210 COPY(regs[0]); COPY(regs[1]); COPY(regs[2]); COPY(regs[3]);
211 COPY(regs[4]); COPY(regs[5]); COPY(regs[6]); COPY(regs[7]);
212 COPY(regs[8]); COPY(regs[9]); COPY(regs[10]); COPY(regs[11]);
213 COPY(regs[12]); COPY(regs[13]); COPY(regs[14]); COPY(regs[15]);
214 COPY(regs[16]); COPY(regs[17]); COPY(regs[18]); COPY(regs[19]);
215 COPY(regs[20]); COPY(regs[21]); COPY(regs[22]); COPY(regs[23]);
216 COPY(regs[24]); COPY(regs[25]); COPY(regs[26]); COPY(regs[27]);
217 COPY(regs[28]); COPY(regs[29]); COPY(regs[30]); COPY(regs[31]);
218 COPY(regs[32]); COPY(regs[33]); COPY(regs[34]); COPY(regs[35]);
219 COPY(regs[36]); COPY(regs[37]); COPY(regs[38]); COPY(regs[39]);
220 COPY(regs[40]); COPY(regs[41]); COPY(regs[42]); COPY(regs[43]);
221 COPY(regs[44]); COPY(regs[45]); COPY(regs[46]); COPY(regs[47]);
222 COPY(regs[48]); COPY(regs[49]); COPY(regs[50]); COPY(regs[51]);
223 COPY(regs[52]); COPY(regs[53]); COPY(regs[54]); COPY(regs[55]);
224 COPY(regs[56]); COPY(regs[57]); COPY(regs[58]); COPY(regs[59]);
225 COPY(regs[60]); COPY(regs[61]); COPY(regs[62]);
226 COPY(tregs[0]); COPY(tregs[1]); COPY(tregs[2]); COPY(tregs[3]);
227 COPY(tregs[4]); COPY(tregs[5]); COPY(tregs[6]); COPY(tregs[7]);
228
229 /* Prevent the signal handler manipulating SR in a way that can
230 crash the kernel. i.e. only allow S, Q, M, PR, SZ, FR to be
231 modified */
232 current_sr = regs->sr;
233 err |= __get_user(new_sr, &sc->sc_sr);
234 regs->sr &= SR_MASK;
235 regs->sr |= (new_sr & ~SR_MASK);
236
237 COPY(pc);
238
239#undef COPY
240
241 /* Must do this last in case it sets regs->sr.fd (i.e. after rest of sr
242 * has been restored above.) */
243 err |= restore_sigcontext_fpu(regs, sc);
244
245 regs->syscall_nr = -1; /* disable syscall checks */
246 err |= __get_user(*r2_p, &sc->sc_regs[REG_RET]);
247 return err;
248}
249
250asmlinkage int sys_sigreturn(unsigned long r2, unsigned long r3,
251 unsigned long r4, unsigned long r5,
252 unsigned long r6, unsigned long r7,
253 struct pt_regs * regs)
254{
255 struct sigframe __user *frame = (struct sigframe __user *) (long) REF_REG_SP;
256 sigset_t set;
257 long long ret;
258
259 /* Always make any pending restarted system calls return -EINTR */
260 current->restart_block.fn = do_no_restart_syscall;
261
262 if (!access_ok(frame, sizeof(*frame)))
263 goto badframe;
264
265 if (__get_user(set.sig[0], &frame->sc.oldmask)
266 || (_NSIG_WORDS > 1
267 && __copy_from_user(&set.sig[1], &frame->extramask,
268 sizeof(frame->extramask))))
269 goto badframe;
270
271 set_current_blocked(&set);
272
273 if (restore_sigcontext(regs, &frame->sc, &ret))
274 goto badframe;
275 regs->pc -= 4;
276
277 return (int) ret;
278
279badframe:
280 force_sig(SIGSEGV);
281 return 0;
282}
283
284asmlinkage int sys_rt_sigreturn(unsigned long r2, unsigned long r3,
285 unsigned long r4, unsigned long r5,
286 unsigned long r6, unsigned long r7,
287 struct pt_regs * regs)
288{
289 struct rt_sigframe __user *frame = (struct rt_sigframe __user *) (long) REF_REG_SP;
290 sigset_t set;
291 long long ret;
292
293 /* Always make any pending restarted system calls return -EINTR */
294 current->restart_block.fn = do_no_restart_syscall;
295
296 if (!access_ok(frame, sizeof(*frame)))
297 goto badframe;
298
299 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
300 goto badframe;
301
302 set_current_blocked(&set);
303
304 if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &ret))
305 goto badframe;
306 regs->pc -= 4;
307
308 if (restore_altstack(&frame->uc.uc_stack))
309 goto badframe;
310
311 return (int) ret;
312
313badframe:
314 force_sig(SIGSEGV);
315 return 0;
316}
317
318/*
319 * Set up a signal frame.
320 */
321static int
322setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
323 unsigned long mask)
324{
325 int err = 0;
326
327 /* Do this first, otherwise is this sets sr->fd, that value isn't preserved. */
328 err |= setup_sigcontext_fpu(regs, sc);
329
330#define COPY(x) err |= __put_user(regs->x, &sc->sc_##x)
331
332 COPY(regs[0]); COPY(regs[1]); COPY(regs[2]); COPY(regs[3]);
333 COPY(regs[4]); COPY(regs[5]); COPY(regs[6]); COPY(regs[7]);
334 COPY(regs[8]); COPY(regs[9]); COPY(regs[10]); COPY(regs[11]);
335 COPY(regs[12]); COPY(regs[13]); COPY(regs[14]); COPY(regs[15]);
336 COPY(regs[16]); COPY(regs[17]); COPY(regs[18]); COPY(regs[19]);
337 COPY(regs[20]); COPY(regs[21]); COPY(regs[22]); COPY(regs[23]);
338 COPY(regs[24]); COPY(regs[25]); COPY(regs[26]); COPY(regs[27]);
339 COPY(regs[28]); COPY(regs[29]); COPY(regs[30]); COPY(regs[31]);
340 COPY(regs[32]); COPY(regs[33]); COPY(regs[34]); COPY(regs[35]);
341 COPY(regs[36]); COPY(regs[37]); COPY(regs[38]); COPY(regs[39]);
342 COPY(regs[40]); COPY(regs[41]); COPY(regs[42]); COPY(regs[43]);
343 COPY(regs[44]); COPY(regs[45]); COPY(regs[46]); COPY(regs[47]);
344 COPY(regs[48]); COPY(regs[49]); COPY(regs[50]); COPY(regs[51]);
345 COPY(regs[52]); COPY(regs[53]); COPY(regs[54]); COPY(regs[55]);
346 COPY(regs[56]); COPY(regs[57]); COPY(regs[58]); COPY(regs[59]);
347 COPY(regs[60]); COPY(regs[61]); COPY(regs[62]);
348 COPY(tregs[0]); COPY(tregs[1]); COPY(tregs[2]); COPY(tregs[3]);
349 COPY(tregs[4]); COPY(tregs[5]); COPY(tregs[6]); COPY(tregs[7]);
350 COPY(sr); COPY(pc);
351
352#undef COPY
353
354 err |= __put_user(mask, &sc->oldmask);
355
356 return err;
357}
358
359/*
360 * Determine which stack to use..
361 */
362static inline void __user *
363get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
364{
365 if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && ! sas_ss_flags(sp))
366 sp = current->sas_ss_sp + current->sas_ss_size;
367
368 return (void __user *)((sp - frame_size) & -8ul);
369}
370
371void sa_default_restorer(void); /* See comments below */
372void sa_default_rt_restorer(void); /* See comments below */
373
374static int setup_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs)
375{
376 struct sigframe __user *frame;
377 int err = 0, sig = ksig->sig;
378 int signal;
379
380 frame = get_sigframe(&ksig->ka, regs->regs[REG_SP], sizeof(*frame));
381
382 if (!access_ok(frame, sizeof(*frame)))
383 return -EFAULT;
384
385 err |= setup_sigcontext(&frame->sc, regs, set->sig[0]);
386
387 /* Give up earlier as i386, in case */
388 if (err)
389 return -EFAULT;
390
391 if (_NSIG_WORDS > 1) {
392 err |= __copy_to_user(frame->extramask, &set->sig[1],
393 sizeof(frame->extramask)); }
394
395 /* Give up earlier as i386, in case */
396 if (err)
397 return -EFAULT;
398
399 /* Set up to return from userspace. If provided, use a stub
400 already in userspace. */
401 if (ksig->ka.sa.sa_flags & SA_RESTORER) {
402 /*
403 * On SH5 all edited pointers are subject to NEFF
404 */
405 DEREF_REG_PR = neff_sign_extend((unsigned long)
406 ksig->ka->sa.sa_restorer | 0x1);
407 } else {
408 /*
409 * Different approach on SH5.
410 * . Endianness independent asm code gets placed in entry.S .
411 * This is limited to four ASM instructions corresponding
412 * to two long longs in size.
413 * . err checking is done on the else branch only
414 * . flush_icache_range() is called upon __put_user() only
415 * . all edited pointers are subject to NEFF
416 * . being code, linker turns ShMedia bit on, always
417 * dereference index -1.
418 */
419 DEREF_REG_PR = neff_sign_extend((unsigned long)
420 frame->retcode | 0x01);
421
422 if (__copy_to_user(frame->retcode,
423 (void *)((unsigned long)sa_default_restorer & (~1)), 16) != 0)
424 return -EFAULT;
425
426 /* Cohere the trampoline with the I-cache. */
427 flush_cache_sigtramp(DEREF_REG_PR-1);
428 }
429
430 /*
431 * Set up registers for signal handler.
432 * All edited pointers are subject to NEFF.
433 */
434 regs->regs[REG_SP] = neff_sign_extend((unsigned long)frame);
435 regs->regs[REG_ARG1] = sig; /* Arg for signal handler */
436
437 /* FIXME:
438 The glibc profiling support for SH-5 needs to be passed a sigcontext
439 so it can retrieve the PC. At some point during 2003 the glibc
440 support was changed to receive the sigcontext through the 2nd
441 argument, but there are still versions of libc.so in use that use
442 the 3rd argument. Until libc.so is stabilised, pass the sigcontext
443 through both 2nd and 3rd arguments.
444 */
445
446 regs->regs[REG_ARG2] = (unsigned long long)(unsigned long)(signed long)&frame->sc;
447 regs->regs[REG_ARG3] = (unsigned long long)(unsigned long)(signed long)&frame->sc;
448
449 regs->pc = neff_sign_extend((unsigned long)ksig->ka.sa.sa_handler);
450
451 /* Broken %016Lx */
452 pr_debug("SIG deliver (#%d,%s:%d): sp=%p pc=%08Lx%08Lx link=%08Lx%08Lx\n",
453 sig, current->comm, current->pid, frame,
454 regs->pc >> 32, regs->pc & 0xffffffff,
455 DEREF_REG_PR >> 32, DEREF_REG_PR & 0xffffffff);
456
457 return 0;
458}
459
460static int setup_rt_frame(struct ksignal *kig, sigset_t *set,
461 struct pt_regs *regs)
462{
463 struct rt_sigframe __user *frame;
464 int err = 0, sig = ksig->sig;
465
466 frame = get_sigframe(&ksig->ka, regs->regs[REG_SP], sizeof(*frame));
467
468 if (!access_ok(frame, sizeof(*frame)))
469 return -EFAULT;
470
471 err |= __put_user(&frame->info, &frame->pinfo);
472 err |= __put_user(&frame->uc, &frame->puc);
473 err |= copy_siginfo_to_user(&frame->info, &ksig->info);
474
475 /* Give up earlier as i386, in case */
476 if (err)
477 return -EFAULT;
478
479 /* Create the ucontext. */
480 err |= __put_user(0, &frame->uc.uc_flags);
481 err |= __put_user(0, &frame->uc.uc_link);
482 err |= __save_altstack(&frame->uc.uc_stack, regs->regs[REG_SP]);
483 err |= setup_sigcontext(&frame->uc.uc_mcontext,
484 regs, set->sig[0]);
485 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
486
487 /* Give up earlier as i386, in case */
488 if (err)
489 return -EFAULT;
490
491 /* Set up to return from userspace. If provided, use a stub
492 already in userspace. */
493 if (ksig->ka.sa.sa_flags & SA_RESTORER) {
494 /*
495 * On SH5 all edited pointers are subject to NEFF
496 */
497 DEREF_REG_PR = neff_sign_extend((unsigned long)
498 ksig->ka.sa.sa_restorer | 0x1);
499 } else {
500 /*
501 * Different approach on SH5.
502 * . Endianness independent asm code gets placed in entry.S .
503 * This is limited to four ASM instructions corresponding
504 * to two long longs in size.
505 * . err checking is done on the else branch only
506 * . flush_icache_range() is called upon __put_user() only
507 * . all edited pointers are subject to NEFF
508 * . being code, linker turns ShMedia bit on, always
509 * dereference index -1.
510 */
511 DEREF_REG_PR = neff_sign_extend((unsigned long)
512 frame->retcode | 0x01);
513
514 if (__copy_to_user(frame->retcode,
515 (void *)((unsigned long)sa_default_rt_restorer & (~1)), 16) != 0)
516 return -EFAULT;
517
518 /* Cohere the trampoline with the I-cache. */
519 flush_icache_range(DEREF_REG_PR-1, DEREF_REG_PR-1+15);
520 }
521
522 /*
523 * Set up registers for signal handler.
524 * All edited pointers are subject to NEFF.
525 */
526 regs->regs[REG_SP] = neff_sign_extend((unsigned long)frame);
527 regs->regs[REG_ARG1] = sig; /* Arg for signal handler */
528 regs->regs[REG_ARG2] = (unsigned long long)(unsigned long)(signed long)&frame->info;
529 regs->regs[REG_ARG3] = (unsigned long long)(unsigned long)(signed long)&frame->uc.uc_mcontext;
530 regs->pc = neff_sign_extend((unsigned long)ksig->ka.sa.sa_handler);
531
532 pr_debug("SIG deliver (#%d,%s:%d): sp=%p pc=%08Lx%08Lx link=%08Lx%08Lx\n",
533 sig, current->comm, current->pid, frame,
534 regs->pc >> 32, regs->pc & 0xffffffff,
535 DEREF_REG_PR >> 32, DEREF_REG_PR & 0xffffffff);
536
537 return 0;
538}
539
540/*
541 * OK, we're invoking a handler
542 */
543static void
544handle_signal(struct ksignal *ksig, struct pt_regs *regs)
545{
546 sigset_t *oldset = sigmask_to_save();
547 int ret;
548
549 /* Set up the stack frame */
550 if (ksig->ka.sa.sa_flags & SA_SIGINFO)
551 ret = setup_rt_frame(ksig, oldset, regs);
552 else
553 ret = setup_frame(ksig, oldset, regs);
554
555 signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP));
556}
557
558asmlinkage void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags)
559{
560 if (thread_info_flags & _TIF_SIGPENDING)
561 do_signal(regs);
562
563 if (thread_info_flags & _TIF_NOTIFY_RESUME) {
564 clear_thread_flag(TIF_NOTIFY_RESUME);
565 tracehook_notify_resume(regs);
566 }
567}