Loading...
1/* linux/arch/sparc/kernel/signal.c
2 *
3 * Copyright (C) 1991, 1992 Linus Torvalds
4 * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
5 * Copyright (C) 1996 Miguel de Icaza (miguel@nuclecu.unam.mx)
6 * Copyright (C) 1997 Eddie C. Dost (ecd@skynet.be)
7 */
8
9#include <linux/sched.h>
10#include <linux/kernel.h>
11#include <linux/signal.h>
12#include <linux/errno.h>
13#include <linux/wait.h>
14#include <linux/ptrace.h>
15#include <linux/unistd.h>
16#include <linux/mm.h>
17#include <linux/tty.h>
18#include <linux/smp.h>
19#include <linux/binfmts.h> /* do_coredum */
20#include <linux/bitops.h>
21#include <linux/tracehook.h>
22
23#include <asm/uaccess.h>
24#include <asm/ptrace.h>
25#include <asm/pgalloc.h>
26#include <asm/pgtable.h>
27#include <asm/cacheflush.h> /* flush_sig_insns */
28
29#include "sigutil.h"
30
31#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
32
33extern void fpsave(unsigned long *fpregs, unsigned long *fsr,
34 void *fpqueue, unsigned long *fpqdepth);
35extern void fpload(unsigned long *fpregs, unsigned long *fsr);
36
37struct signal_frame {
38 struct sparc_stackf ss;
39 __siginfo32_t info;
40 __siginfo_fpu_t __user *fpu_save;
41 unsigned long insns[2] __attribute__ ((aligned (8)));
42 unsigned int extramask[_NSIG_WORDS - 1];
43 unsigned int extra_size; /* Should be 0 */
44 __siginfo_rwin_t __user *rwin_save;
45} __attribute__((aligned(8)));
46
47struct rt_signal_frame {
48 struct sparc_stackf ss;
49 siginfo_t info;
50 struct pt_regs regs;
51 sigset_t mask;
52 __siginfo_fpu_t __user *fpu_save;
53 unsigned int insns[2];
54 stack_t stack;
55 unsigned int extra_size; /* Should be 0 */
56 __siginfo_rwin_t __user *rwin_save;
57} __attribute__((aligned(8)));
58
59/* Align macros */
60#define SF_ALIGNEDSZ (((sizeof(struct signal_frame) + 7) & (~7)))
61#define RT_ALIGNEDSZ (((sizeof(struct rt_signal_frame) + 7) & (~7)))
62
63static int _sigpause_common(old_sigset_t set)
64{
65 sigset_t blocked;
66
67 current->saved_sigmask = current->blocked;
68
69 set &= _BLOCKABLE;
70 siginitset(&blocked, set);
71 set_current_blocked(&blocked);
72
73 current->state = TASK_INTERRUPTIBLE;
74 schedule();
75 set_thread_flag(TIF_RESTORE_SIGMASK);
76
77 return -ERESTARTNOHAND;
78}
79
80asmlinkage int sys_sigsuspend(old_sigset_t set)
81{
82 return _sigpause_common(set);
83}
84
85asmlinkage void do_sigreturn(struct pt_regs *regs)
86{
87 struct signal_frame __user *sf;
88 unsigned long up_psr, pc, npc;
89 sigset_t set;
90 __siginfo_fpu_t __user *fpu_save;
91 __siginfo_rwin_t __user *rwin_save;
92 int err;
93
94 /* Always make any pending restarted system calls return -EINTR */
95 current_thread_info()->restart_block.fn = do_no_restart_syscall;
96
97 synchronize_user_stack();
98
99 sf = (struct signal_frame __user *) regs->u_regs[UREG_FP];
100
101 /* 1. Make sure we are not getting garbage from the user */
102 if (!access_ok(VERIFY_READ, sf, sizeof(*sf)))
103 goto segv_and_exit;
104
105 if (((unsigned long) sf) & 3)
106 goto segv_and_exit;
107
108 err = __get_user(pc, &sf->info.si_regs.pc);
109 err |= __get_user(npc, &sf->info.si_regs.npc);
110
111 if ((pc | npc) & 3)
112 goto segv_and_exit;
113
114 /* 2. Restore the state */
115 up_psr = regs->psr;
116 err |= __copy_from_user(regs, &sf->info.si_regs, sizeof(struct pt_regs));
117
118 /* User can only change condition codes and FPU enabling in %psr. */
119 regs->psr = (up_psr & ~(PSR_ICC | PSR_EF))
120 | (regs->psr & (PSR_ICC | PSR_EF));
121
122 /* Prevent syscall restart. */
123 pt_regs_clear_syscall(regs);
124
125 err |= __get_user(fpu_save, &sf->fpu_save);
126 if (fpu_save)
127 err |= restore_fpu_state(regs, fpu_save);
128 err |= __get_user(rwin_save, &sf->rwin_save);
129 if (rwin_save)
130 err |= restore_rwin_state(rwin_save);
131
132 /* This is pretty much atomic, no amount locking would prevent
133 * the races which exist anyways.
134 */
135 err |= __get_user(set.sig[0], &sf->info.si_mask);
136 err |= __copy_from_user(&set.sig[1], &sf->extramask,
137 (_NSIG_WORDS-1) * sizeof(unsigned int));
138
139 if (err)
140 goto segv_and_exit;
141
142 sigdelsetmask(&set, ~_BLOCKABLE);
143 set_current_blocked(&set);
144 return;
145
146segv_and_exit:
147 force_sig(SIGSEGV, current);
148}
149
150asmlinkage void do_rt_sigreturn(struct pt_regs *regs)
151{
152 struct rt_signal_frame __user *sf;
153 unsigned int psr, pc, npc;
154 __siginfo_fpu_t __user *fpu_save;
155 __siginfo_rwin_t __user *rwin_save;
156 mm_segment_t old_fs;
157 sigset_t set;
158 stack_t st;
159 int err;
160
161 synchronize_user_stack();
162 sf = (struct rt_signal_frame __user *) regs->u_regs[UREG_FP];
163 if (!access_ok(VERIFY_READ, sf, sizeof(*sf)) ||
164 (((unsigned long) sf) & 0x03))
165 goto segv;
166
167 err = __get_user(pc, &sf->regs.pc);
168 err |= __get_user(npc, &sf->regs.npc);
169 err |= ((pc | npc) & 0x03);
170
171 err |= __get_user(regs->y, &sf->regs.y);
172 err |= __get_user(psr, &sf->regs.psr);
173
174 err |= __copy_from_user(®s->u_regs[UREG_G1],
175 &sf->regs.u_regs[UREG_G1], 15 * sizeof(u32));
176
177 regs->psr = (regs->psr & ~PSR_ICC) | (psr & PSR_ICC);
178
179 /* Prevent syscall restart. */
180 pt_regs_clear_syscall(regs);
181
182 err |= __get_user(fpu_save, &sf->fpu_save);
183 if (!err && fpu_save)
184 err |= restore_fpu_state(regs, fpu_save);
185 err |= __copy_from_user(&set, &sf->mask, sizeof(sigset_t));
186
187 err |= __copy_from_user(&st, &sf->stack, sizeof(stack_t));
188
189 if (err)
190 goto segv;
191
192 regs->pc = pc;
193 regs->npc = npc;
194
195 /* It is more difficult to avoid calling this function than to
196 * call it and ignore errors.
197 */
198 old_fs = get_fs();
199 set_fs(KERNEL_DS);
200 do_sigaltstack((const stack_t __user *) &st, NULL, (unsigned long)sf);
201 set_fs(old_fs);
202
203 err |= __get_user(rwin_save, &sf->rwin_save);
204 if (!err && rwin_save) {
205 if (restore_rwin_state(rwin_save))
206 goto segv;
207 }
208
209 sigdelsetmask(&set, ~_BLOCKABLE);
210 set_current_blocked(&set);
211 return;
212segv:
213 force_sig(SIGSEGV, current);
214}
215
216/* Checks if the fp is valid */
217static inline int invalid_frame_pointer(void __user *fp, int fplen)
218{
219 if ((((unsigned long) fp) & 7) ||
220 !__access_ok((unsigned long)fp, fplen) ||
221 ((sparc_cpu_model == sun4 || sparc_cpu_model == sun4c) &&
222 ((unsigned long) fp < 0xe0000000 && (unsigned long) fp >= 0x20000000)))
223 return 1;
224
225 return 0;
226}
227
228static inline void __user *get_sigframe(struct sigaction *sa, struct pt_regs *regs, unsigned long framesize)
229{
230 unsigned long sp = regs->u_regs[UREG_FP];
231
232 /*
233 * If we are on the alternate signal stack and would overflow it, don't.
234 * Return an always-bogus address instead so we will die with SIGSEGV.
235 */
236 if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize)))
237 return (void __user *) -1L;
238
239 /* This is the X/Open sanctioned signal stack switching. */
240 if (sa->sa_flags & SA_ONSTACK) {
241 if (sas_ss_flags(sp) == 0)
242 sp = current->sas_ss_sp + current->sas_ss_size;
243 }
244
245 sp -= framesize;
246
247 /* Always align the stack frame. This handles two cases. First,
248 * sigaltstack need not be mindful of platform specific stack
249 * alignment. Second, if we took this signal because the stack
250 * is not aligned properly, we'd like to take the signal cleanly
251 * and report that.
252 */
253 sp &= ~15UL;
254
255 return (void __user *) sp;
256}
257
258static int setup_frame(struct k_sigaction *ka, struct pt_regs *regs,
259 int signo, sigset_t *oldset)
260{
261 struct signal_frame __user *sf;
262 int sigframe_size, err, wsaved;
263 void __user *tail;
264
265 /* 1. Make sure everything is clean */
266 synchronize_user_stack();
267
268 wsaved = current_thread_info()->w_saved;
269
270 sigframe_size = sizeof(*sf);
271 if (used_math())
272 sigframe_size += sizeof(__siginfo_fpu_t);
273 if (wsaved)
274 sigframe_size += sizeof(__siginfo_rwin_t);
275
276 sf = (struct signal_frame __user *)
277 get_sigframe(&ka->sa, regs, sigframe_size);
278
279 if (invalid_frame_pointer(sf, sigframe_size))
280 goto sigill_and_return;
281
282 tail = sf + 1;
283
284 /* 2. Save the current process state */
285 err = __copy_to_user(&sf->info.si_regs, regs, sizeof(struct pt_regs));
286
287 err |= __put_user(0, &sf->extra_size);
288
289 if (used_math()) {
290 __siginfo_fpu_t __user *fp = tail;
291 tail += sizeof(*fp);
292 err |= save_fpu_state(regs, fp);
293 err |= __put_user(fp, &sf->fpu_save);
294 } else {
295 err |= __put_user(0, &sf->fpu_save);
296 }
297 if (wsaved) {
298 __siginfo_rwin_t __user *rwp = tail;
299 tail += sizeof(*rwp);
300 err |= save_rwin_state(wsaved, rwp);
301 err |= __put_user(rwp, &sf->rwin_save);
302 } else {
303 err |= __put_user(0, &sf->rwin_save);
304 }
305
306 err |= __put_user(oldset->sig[0], &sf->info.si_mask);
307 err |= __copy_to_user(sf->extramask, &oldset->sig[1],
308 (_NSIG_WORDS - 1) * sizeof(unsigned int));
309 if (!wsaved) {
310 err |= __copy_to_user(sf, (char *) regs->u_regs[UREG_FP],
311 sizeof(struct reg_window32));
312 } else {
313 struct reg_window32 *rp;
314
315 rp = ¤t_thread_info()->reg_window[wsaved - 1];
316 err |= __copy_to_user(sf, rp, sizeof(struct reg_window32));
317 }
318 if (err)
319 goto sigsegv;
320
321 /* 3. signal handler back-trampoline and parameters */
322 regs->u_regs[UREG_FP] = (unsigned long) sf;
323 regs->u_regs[UREG_I0] = signo;
324 regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
325 regs->u_regs[UREG_I2] = (unsigned long) &sf->info;
326
327 /* 4. signal handler */
328 regs->pc = (unsigned long) ka->sa.sa_handler;
329 regs->npc = (regs->pc + 4);
330
331 /* 5. return to kernel instructions */
332 if (ka->ka_restorer)
333 regs->u_regs[UREG_I7] = (unsigned long)ka->ka_restorer;
334 else {
335 regs->u_regs[UREG_I7] = (unsigned long)(&(sf->insns[0]) - 2);
336
337 /* mov __NR_sigreturn, %g1 */
338 err |= __put_user(0x821020d8, &sf->insns[0]);
339
340 /* t 0x10 */
341 err |= __put_user(0x91d02010, &sf->insns[1]);
342 if (err)
343 goto sigsegv;
344
345 /* Flush instruction space. */
346 flush_sig_insns(current->mm, (unsigned long) &(sf->insns[0]));
347 }
348 return 0;
349
350sigill_and_return:
351 do_exit(SIGILL);
352 return -EINVAL;
353
354sigsegv:
355 force_sigsegv(signo, current);
356 return -EFAULT;
357}
358
359static int setup_rt_frame(struct k_sigaction *ka, struct pt_regs *regs,
360 int signo, sigset_t *oldset, siginfo_t *info)
361{
362 struct rt_signal_frame __user *sf;
363 int sigframe_size, wsaved;
364 void __user *tail;
365 unsigned int psr;
366 int err;
367
368 synchronize_user_stack();
369 wsaved = current_thread_info()->w_saved;
370 sigframe_size = sizeof(*sf);
371 if (used_math())
372 sigframe_size += sizeof(__siginfo_fpu_t);
373 if (wsaved)
374 sigframe_size += sizeof(__siginfo_rwin_t);
375 sf = (struct rt_signal_frame __user *)
376 get_sigframe(&ka->sa, regs, sigframe_size);
377 if (invalid_frame_pointer(sf, sigframe_size))
378 goto sigill;
379
380 tail = sf + 1;
381 err = __put_user(regs->pc, &sf->regs.pc);
382 err |= __put_user(regs->npc, &sf->regs.npc);
383 err |= __put_user(regs->y, &sf->regs.y);
384 psr = regs->psr;
385 if (used_math())
386 psr |= PSR_EF;
387 err |= __put_user(psr, &sf->regs.psr);
388 err |= __copy_to_user(&sf->regs.u_regs, regs->u_regs, sizeof(regs->u_regs));
389 err |= __put_user(0, &sf->extra_size);
390
391 if (psr & PSR_EF) {
392 __siginfo_fpu_t *fp = tail;
393 tail += sizeof(*fp);
394 err |= save_fpu_state(regs, fp);
395 err |= __put_user(fp, &sf->fpu_save);
396 } else {
397 err |= __put_user(0, &sf->fpu_save);
398 }
399 if (wsaved) {
400 __siginfo_rwin_t *rwp = tail;
401 tail += sizeof(*rwp);
402 err |= save_rwin_state(wsaved, rwp);
403 err |= __put_user(rwp, &sf->rwin_save);
404 } else {
405 err |= __put_user(0, &sf->rwin_save);
406 }
407 err |= __copy_to_user(&sf->mask, &oldset->sig[0], sizeof(sigset_t));
408
409 /* Setup sigaltstack */
410 err |= __put_user(current->sas_ss_sp, &sf->stack.ss_sp);
411 err |= __put_user(sas_ss_flags(regs->u_regs[UREG_FP]), &sf->stack.ss_flags);
412 err |= __put_user(current->sas_ss_size, &sf->stack.ss_size);
413
414 if (!wsaved) {
415 err |= __copy_to_user(sf, (char *) regs->u_regs[UREG_FP],
416 sizeof(struct reg_window32));
417 } else {
418 struct reg_window32 *rp;
419
420 rp = ¤t_thread_info()->reg_window[wsaved - 1];
421 err |= __copy_to_user(sf, rp, sizeof(struct reg_window32));
422 }
423
424 err |= copy_siginfo_to_user(&sf->info, info);
425
426 if (err)
427 goto sigsegv;
428
429 regs->u_regs[UREG_FP] = (unsigned long) sf;
430 regs->u_regs[UREG_I0] = signo;
431 regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
432 regs->u_regs[UREG_I2] = (unsigned long) &sf->regs;
433
434 regs->pc = (unsigned long) ka->sa.sa_handler;
435 regs->npc = (regs->pc + 4);
436
437 if (ka->ka_restorer)
438 regs->u_regs[UREG_I7] = (unsigned long)ka->ka_restorer;
439 else {
440 regs->u_regs[UREG_I7] = (unsigned long)(&(sf->insns[0]) - 2);
441
442 /* mov __NR_sigreturn, %g1 */
443 err |= __put_user(0x821020d8, &sf->insns[0]);
444
445 /* t 0x10 */
446 err |= __put_user(0x91d02010, &sf->insns[1]);
447 if (err)
448 goto sigsegv;
449
450 /* Flush instruction space. */
451 flush_sig_insns(current->mm, (unsigned long) &(sf->insns[0]));
452 }
453 return 0;
454
455sigill:
456 do_exit(SIGILL);
457 return -EINVAL;
458
459sigsegv:
460 force_sigsegv(signo, current);
461 return -EFAULT;
462}
463
464static inline int
465handle_signal(unsigned long signr, struct k_sigaction *ka,
466 siginfo_t *info, sigset_t *oldset, struct pt_regs *regs)
467{
468 sigset_t blocked;
469 int err;
470
471 if (ka->sa.sa_flags & SA_SIGINFO)
472 err = setup_rt_frame(ka, regs, signr, oldset, info);
473 else
474 err = setup_frame(ka, regs, signr, oldset);
475
476 if (err)
477 return err;
478
479 sigorsets(&blocked, ¤t->blocked, &ka->sa.sa_mask);
480 if (!(ka->sa.sa_flags & SA_NOMASK))
481 sigaddset(&blocked, signr);
482 set_current_blocked(&blocked);
483
484 tracehook_signal_handler(signr, info, ka, regs, 0);
485
486 return 0;
487}
488
489static inline void syscall_restart(unsigned long orig_i0, struct pt_regs *regs,
490 struct sigaction *sa)
491{
492 switch(regs->u_regs[UREG_I0]) {
493 case ERESTART_RESTARTBLOCK:
494 case ERESTARTNOHAND:
495 no_system_call_restart:
496 regs->u_regs[UREG_I0] = EINTR;
497 regs->psr |= PSR_C;
498 break;
499 case ERESTARTSYS:
500 if (!(sa->sa_flags & SA_RESTART))
501 goto no_system_call_restart;
502 /* fallthrough */
503 case ERESTARTNOINTR:
504 regs->u_regs[UREG_I0] = orig_i0;
505 regs->pc -= 4;
506 regs->npc -= 4;
507 }
508}
509
510/* Note that 'init' is a special process: it doesn't get signals it doesn't
511 * want to handle. Thus you cannot kill init even with a SIGKILL even by
512 * mistake.
513 */
514static void do_signal(struct pt_regs *regs, unsigned long orig_i0)
515{
516 struct k_sigaction ka;
517 int restart_syscall;
518 sigset_t *oldset;
519 siginfo_t info;
520 int signr;
521
522 if (pt_regs_is_syscall(regs) && (regs->psr & PSR_C))
523 restart_syscall = 1;
524 else
525 restart_syscall = 0;
526
527 if (test_thread_flag(TIF_RESTORE_SIGMASK))
528 oldset = ¤t->saved_sigmask;
529 else
530 oldset = ¤t->blocked;
531
532 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
533
534 /* If the debugger messes with the program counter, it clears
535 * the software "in syscall" bit, directing us to not perform
536 * a syscall restart.
537 */
538 if (restart_syscall && !pt_regs_is_syscall(regs))
539 restart_syscall = 0;
540
541 if (signr > 0) {
542 if (restart_syscall)
543 syscall_restart(orig_i0, regs, &ka.sa);
544 if (handle_signal(signr, &ka, &info, oldset, regs) == 0) {
545 /* a signal was successfully delivered; the saved
546 * sigmask will have been stored in the signal frame,
547 * and will be restored by sigreturn, so we can simply
548 * clear the TIF_RESTORE_SIGMASK flag.
549 */
550 if (test_thread_flag(TIF_RESTORE_SIGMASK))
551 clear_thread_flag(TIF_RESTORE_SIGMASK);
552 }
553 return;
554 }
555 if (restart_syscall &&
556 (regs->u_regs[UREG_I0] == ERESTARTNOHAND ||
557 regs->u_regs[UREG_I0] == ERESTARTSYS ||
558 regs->u_regs[UREG_I0] == ERESTARTNOINTR)) {
559 /* replay the system call when we are done */
560 regs->u_regs[UREG_I0] = orig_i0;
561 regs->pc -= 4;
562 regs->npc -= 4;
563 pt_regs_clear_syscall(regs);
564 }
565 if (restart_syscall &&
566 regs->u_regs[UREG_I0] == ERESTART_RESTARTBLOCK) {
567 regs->u_regs[UREG_G1] = __NR_restart_syscall;
568 regs->pc -= 4;
569 regs->npc -= 4;
570 pt_regs_clear_syscall(regs);
571 }
572
573 /* if there's no signal to deliver, we just put the saved sigmask
574 * back
575 */
576 if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
577 clear_thread_flag(TIF_RESTORE_SIGMASK);
578 set_current_blocked(¤t->saved_sigmask);
579 }
580}
581
582void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0,
583 unsigned long thread_info_flags)
584{
585 if (thread_info_flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK))
586 do_signal(regs, orig_i0);
587 if (thread_info_flags & _TIF_NOTIFY_RESUME) {
588 clear_thread_flag(TIF_NOTIFY_RESUME);
589 tracehook_notify_resume(regs);
590 if (current->replacement_session_keyring)
591 key_replace_session_keyring();
592 }
593}
594
595asmlinkage int
596do_sys_sigstack(struct sigstack __user *ssptr, struct sigstack __user *ossptr,
597 unsigned long sp)
598{
599 int ret = -EFAULT;
600
601 /* First see if old state is wanted. */
602 if (ossptr) {
603 if (put_user(current->sas_ss_sp + current->sas_ss_size,
604 &ossptr->the_stack) ||
605 __put_user(on_sig_stack(sp), &ossptr->cur_status))
606 goto out;
607 }
608
609 /* Now see if we want to update the new state. */
610 if (ssptr) {
611 char *ss_sp;
612
613 if (get_user(ss_sp, &ssptr->the_stack))
614 goto out;
615 /* If the current stack was set with sigaltstack, don't
616 swap stacks while we are on it. */
617 ret = -EPERM;
618 if (current->sas_ss_sp && on_sig_stack(sp))
619 goto out;
620
621 /* Since we don't know the extent of the stack, and we don't
622 track onstack-ness, but rather calculate it, we must
623 presume a size. Ho hum this interface is lossy. */
624 current->sas_ss_sp = (unsigned long)ss_sp - SIGSTKSZ;
625 current->sas_ss_size = SIGSTKSZ;
626 }
627 ret = 0;
628out:
629 return ret;
630}
1/* linux/arch/sparc/kernel/signal.c
2 *
3 * Copyright (C) 1991, 1992 Linus Torvalds
4 * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
5 * Copyright (C) 1996 Miguel de Icaza (miguel@nuclecu.unam.mx)
6 * Copyright (C) 1997 Eddie C. Dost (ecd@skynet.be)
7 */
8
9#include <linux/sched.h>
10#include <linux/kernel.h>
11#include <linux/signal.h>
12#include <linux/errno.h>
13#include <linux/wait.h>
14#include <linux/ptrace.h>
15#include <linux/unistd.h>
16#include <linux/mm.h>
17#include <linux/tty.h>
18#include <linux/smp.h>
19#include <linux/binfmts.h> /* do_coredum */
20#include <linux/bitops.h>
21#include <linux/tracehook.h>
22
23#include <linux/uaccess.h>
24#include <asm/ptrace.h>
25#include <asm/pgalloc.h>
26#include <asm/pgtable.h>
27#include <asm/cacheflush.h> /* flush_sig_insns */
28#include <asm/switch_to.h>
29
30#include "sigutil.h"
31#include "kernel.h"
32
33extern void fpsave(unsigned long *fpregs, unsigned long *fsr,
34 void *fpqueue, unsigned long *fpqdepth);
35extern void fpload(unsigned long *fpregs, unsigned long *fsr);
36
37struct signal_frame {
38 struct sparc_stackf ss;
39 __siginfo32_t info;
40 __siginfo_fpu_t __user *fpu_save;
41 unsigned long insns[2] __attribute__ ((aligned (8)));
42 unsigned int extramask[_NSIG_WORDS - 1];
43 unsigned int extra_size; /* Should be 0 */
44 __siginfo_rwin_t __user *rwin_save;
45} __attribute__((aligned(8)));
46
47struct rt_signal_frame {
48 struct sparc_stackf ss;
49 siginfo_t info;
50 struct pt_regs regs;
51 sigset_t mask;
52 __siginfo_fpu_t __user *fpu_save;
53 unsigned int insns[2];
54 stack_t stack;
55 unsigned int extra_size; /* Should be 0 */
56 __siginfo_rwin_t __user *rwin_save;
57} __attribute__((aligned(8)));
58
59/* Align macros */
60#define SF_ALIGNEDSZ (((sizeof(struct signal_frame) + 7) & (~7)))
61#define RT_ALIGNEDSZ (((sizeof(struct rt_signal_frame) + 7) & (~7)))
62
63/* Checks if the fp is valid. We always build signal frames which are
64 * 16-byte aligned, therefore we can always enforce that the restore
65 * frame has that property as well.
66 */
67static inline bool invalid_frame_pointer(void __user *fp, int fplen)
68{
69 if ((((unsigned long) fp) & 15) || !__access_ok((unsigned long)fp, fplen))
70 return true;
71
72 return false;
73}
74
75asmlinkage void do_sigreturn(struct pt_regs *regs)
76{
77 unsigned long up_psr, pc, npc, ufp;
78 struct signal_frame __user *sf;
79 sigset_t set;
80 __siginfo_fpu_t __user *fpu_save;
81 __siginfo_rwin_t __user *rwin_save;
82 int err;
83
84 /* Always make any pending restarted system calls return -EINTR */
85 current->restart_block.fn = do_no_restart_syscall;
86
87 synchronize_user_stack();
88
89 sf = (struct signal_frame __user *) regs->u_regs[UREG_FP];
90
91 /* 1. Make sure we are not getting garbage from the user */
92 if (invalid_frame_pointer(sf, sizeof(*sf)))
93 goto segv_and_exit;
94
95 if (get_user(ufp, &sf->info.si_regs.u_regs[UREG_FP]))
96 goto segv_and_exit;
97
98 if (ufp & 0x7)
99 goto segv_and_exit;
100
101 err = __get_user(pc, &sf->info.si_regs.pc);
102 err |= __get_user(npc, &sf->info.si_regs.npc);
103
104 if ((pc | npc) & 3)
105 goto segv_and_exit;
106
107 /* 2. Restore the state */
108 up_psr = regs->psr;
109 err |= __copy_from_user(regs, &sf->info.si_regs, sizeof(struct pt_regs));
110
111 /* User can only change condition codes and FPU enabling in %psr. */
112 regs->psr = (up_psr & ~(PSR_ICC | PSR_EF))
113 | (regs->psr & (PSR_ICC | PSR_EF));
114
115 /* Prevent syscall restart. */
116 pt_regs_clear_syscall(regs);
117
118 err |= __get_user(fpu_save, &sf->fpu_save);
119 if (fpu_save)
120 err |= restore_fpu_state(regs, fpu_save);
121 err |= __get_user(rwin_save, &sf->rwin_save);
122 if (rwin_save)
123 err |= restore_rwin_state(rwin_save);
124
125 /* This is pretty much atomic, no amount locking would prevent
126 * the races which exist anyways.
127 */
128 err |= __get_user(set.sig[0], &sf->info.si_mask);
129 err |= __copy_from_user(&set.sig[1], &sf->extramask,
130 (_NSIG_WORDS-1) * sizeof(unsigned int));
131
132 if (err)
133 goto segv_and_exit;
134
135 set_current_blocked(&set);
136 return;
137
138segv_and_exit:
139 force_sig(SIGSEGV, current);
140}
141
142asmlinkage void do_rt_sigreturn(struct pt_regs *regs)
143{
144 struct rt_signal_frame __user *sf;
145 unsigned int psr, pc, npc, ufp;
146 __siginfo_fpu_t __user *fpu_save;
147 __siginfo_rwin_t __user *rwin_save;
148 sigset_t set;
149 int err;
150
151 synchronize_user_stack();
152 sf = (struct rt_signal_frame __user *) regs->u_regs[UREG_FP];
153 if (invalid_frame_pointer(sf, sizeof(*sf)))
154 goto segv;
155
156 if (get_user(ufp, &sf->regs.u_regs[UREG_FP]))
157 goto segv;
158
159 if (ufp & 0x7)
160 goto segv;
161
162 err = __get_user(pc, &sf->regs.pc);
163 err |= __get_user(npc, &sf->regs.npc);
164 err |= ((pc | npc) & 0x03);
165
166 err |= __get_user(regs->y, &sf->regs.y);
167 err |= __get_user(psr, &sf->regs.psr);
168
169 err |= __copy_from_user(®s->u_regs[UREG_G1],
170 &sf->regs.u_regs[UREG_G1], 15 * sizeof(u32));
171
172 regs->psr = (regs->psr & ~PSR_ICC) | (psr & PSR_ICC);
173
174 /* Prevent syscall restart. */
175 pt_regs_clear_syscall(regs);
176
177 err |= __get_user(fpu_save, &sf->fpu_save);
178 if (!err && fpu_save)
179 err |= restore_fpu_state(regs, fpu_save);
180 err |= __copy_from_user(&set, &sf->mask, sizeof(sigset_t));
181 err |= restore_altstack(&sf->stack);
182
183 if (err)
184 goto segv;
185
186 regs->pc = pc;
187 regs->npc = npc;
188
189 err |= __get_user(rwin_save, &sf->rwin_save);
190 if (!err && rwin_save) {
191 if (restore_rwin_state(rwin_save))
192 goto segv;
193 }
194
195 set_current_blocked(&set);
196 return;
197segv:
198 force_sig(SIGSEGV, current);
199}
200
201static inline void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs, unsigned long framesize)
202{
203 unsigned long sp = regs->u_regs[UREG_FP];
204
205 /*
206 * If we are on the alternate signal stack and would overflow it, don't.
207 * Return an always-bogus address instead so we will die with SIGSEGV.
208 */
209 if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize)))
210 return (void __user *) -1L;
211
212 /* This is the X/Open sanctioned signal stack switching. */
213 sp = sigsp(sp, ksig) - framesize;
214
215 /* Always align the stack frame. This handles two cases. First,
216 * sigaltstack need not be mindful of platform specific stack
217 * alignment. Second, if we took this signal because the stack
218 * is not aligned properly, we'd like to take the signal cleanly
219 * and report that.
220 */
221 sp &= ~15UL;
222
223 return (void __user *) sp;
224}
225
226static int setup_frame(struct ksignal *ksig, struct pt_regs *regs,
227 sigset_t *oldset)
228{
229 struct signal_frame __user *sf;
230 int sigframe_size, err, wsaved;
231 void __user *tail;
232
233 /* 1. Make sure everything is clean */
234 synchronize_user_stack();
235
236 wsaved = current_thread_info()->w_saved;
237
238 sigframe_size = sizeof(*sf);
239 if (used_math())
240 sigframe_size += sizeof(__siginfo_fpu_t);
241 if (wsaved)
242 sigframe_size += sizeof(__siginfo_rwin_t);
243
244 sf = (struct signal_frame __user *)
245 get_sigframe(ksig, regs, sigframe_size);
246
247 if (invalid_frame_pointer(sf, sigframe_size)) {
248 do_exit(SIGILL);
249 return -EINVAL;
250 }
251
252 tail = sf + 1;
253
254 /* 2. Save the current process state */
255 err = __copy_to_user(&sf->info.si_regs, regs, sizeof(struct pt_regs));
256
257 err |= __put_user(0, &sf->extra_size);
258
259 if (used_math()) {
260 __siginfo_fpu_t __user *fp = tail;
261 tail += sizeof(*fp);
262 err |= save_fpu_state(regs, fp);
263 err |= __put_user(fp, &sf->fpu_save);
264 } else {
265 err |= __put_user(0, &sf->fpu_save);
266 }
267 if (wsaved) {
268 __siginfo_rwin_t __user *rwp = tail;
269 tail += sizeof(*rwp);
270 err |= save_rwin_state(wsaved, rwp);
271 err |= __put_user(rwp, &sf->rwin_save);
272 } else {
273 err |= __put_user(0, &sf->rwin_save);
274 }
275
276 err |= __put_user(oldset->sig[0], &sf->info.si_mask);
277 err |= __copy_to_user(sf->extramask, &oldset->sig[1],
278 (_NSIG_WORDS - 1) * sizeof(unsigned int));
279 if (!wsaved) {
280 err |= __copy_to_user(sf, (char *) regs->u_regs[UREG_FP],
281 sizeof(struct reg_window32));
282 } else {
283 struct reg_window32 *rp;
284
285 rp = ¤t_thread_info()->reg_window[wsaved - 1];
286 err |= __copy_to_user(sf, rp, sizeof(struct reg_window32));
287 }
288 if (err)
289 return err;
290
291 /* 3. signal handler back-trampoline and parameters */
292 regs->u_regs[UREG_FP] = (unsigned long) sf;
293 regs->u_regs[UREG_I0] = ksig->sig;
294 regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
295 regs->u_regs[UREG_I2] = (unsigned long) &sf->info;
296
297 /* 4. signal handler */
298 regs->pc = (unsigned long) ksig->ka.sa.sa_handler;
299 regs->npc = (regs->pc + 4);
300
301 /* 5. return to kernel instructions */
302 if (ksig->ka.ka_restorer)
303 regs->u_regs[UREG_I7] = (unsigned long)ksig->ka.ka_restorer;
304 else {
305 regs->u_regs[UREG_I7] = (unsigned long)(&(sf->insns[0]) - 2);
306
307 /* mov __NR_sigreturn, %g1 */
308 err |= __put_user(0x821020d8, &sf->insns[0]);
309
310 /* t 0x10 */
311 err |= __put_user(0x91d02010, &sf->insns[1]);
312 if (err)
313 return err;
314
315 /* Flush instruction space. */
316 flush_sig_insns(current->mm, (unsigned long) &(sf->insns[0]));
317 }
318 return 0;
319}
320
321static int setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs,
322 sigset_t *oldset)
323{
324 struct rt_signal_frame __user *sf;
325 int sigframe_size, wsaved;
326 void __user *tail;
327 unsigned int psr;
328 int err;
329
330 synchronize_user_stack();
331 wsaved = current_thread_info()->w_saved;
332 sigframe_size = sizeof(*sf);
333 if (used_math())
334 sigframe_size += sizeof(__siginfo_fpu_t);
335 if (wsaved)
336 sigframe_size += sizeof(__siginfo_rwin_t);
337 sf = (struct rt_signal_frame __user *)
338 get_sigframe(ksig, regs, sigframe_size);
339 if (invalid_frame_pointer(sf, sigframe_size)) {
340 do_exit(SIGILL);
341 return -EINVAL;
342 }
343
344 tail = sf + 1;
345 err = __put_user(regs->pc, &sf->regs.pc);
346 err |= __put_user(regs->npc, &sf->regs.npc);
347 err |= __put_user(regs->y, &sf->regs.y);
348 psr = regs->psr;
349 if (used_math())
350 psr |= PSR_EF;
351 err |= __put_user(psr, &sf->regs.psr);
352 err |= __copy_to_user(&sf->regs.u_regs, regs->u_regs, sizeof(regs->u_regs));
353 err |= __put_user(0, &sf->extra_size);
354
355 if (psr & PSR_EF) {
356 __siginfo_fpu_t __user *fp = tail;
357 tail += sizeof(*fp);
358 err |= save_fpu_state(regs, fp);
359 err |= __put_user(fp, &sf->fpu_save);
360 } else {
361 err |= __put_user(0, &sf->fpu_save);
362 }
363 if (wsaved) {
364 __siginfo_rwin_t __user *rwp = tail;
365 tail += sizeof(*rwp);
366 err |= save_rwin_state(wsaved, rwp);
367 err |= __put_user(rwp, &sf->rwin_save);
368 } else {
369 err |= __put_user(0, &sf->rwin_save);
370 }
371 err |= __copy_to_user(&sf->mask, &oldset->sig[0], sizeof(sigset_t));
372
373 /* Setup sigaltstack */
374 err |= __save_altstack(&sf->stack, regs->u_regs[UREG_FP]);
375
376 if (!wsaved) {
377 err |= __copy_to_user(sf, (char *) regs->u_regs[UREG_FP],
378 sizeof(struct reg_window32));
379 } else {
380 struct reg_window32 *rp;
381
382 rp = ¤t_thread_info()->reg_window[wsaved - 1];
383 err |= __copy_to_user(sf, rp, sizeof(struct reg_window32));
384 }
385
386 err |= copy_siginfo_to_user(&sf->info, &ksig->info);
387
388 if (err)
389 return err;
390
391 regs->u_regs[UREG_FP] = (unsigned long) sf;
392 regs->u_regs[UREG_I0] = ksig->sig;
393 regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
394 regs->u_regs[UREG_I2] = (unsigned long) &sf->regs;
395
396 regs->pc = (unsigned long) ksig->ka.sa.sa_handler;
397 regs->npc = (regs->pc + 4);
398
399 if (ksig->ka.ka_restorer)
400 regs->u_regs[UREG_I7] = (unsigned long)ksig->ka.ka_restorer;
401 else {
402 regs->u_regs[UREG_I7] = (unsigned long)(&(sf->insns[0]) - 2);
403
404 /* mov __NR_sigreturn, %g1 */
405 err |= __put_user(0x821020d8, &sf->insns[0]);
406
407 /* t 0x10 */
408 err |= __put_user(0x91d02010, &sf->insns[1]);
409 if (err)
410 return err;
411
412 /* Flush instruction space. */
413 flush_sig_insns(current->mm, (unsigned long) &(sf->insns[0]));
414 }
415 return 0;
416}
417
418static inline void
419handle_signal(struct ksignal *ksig, struct pt_regs *regs)
420{
421 sigset_t *oldset = sigmask_to_save();
422 int err;
423
424 if (ksig->ka.sa.sa_flags & SA_SIGINFO)
425 err = setup_rt_frame(ksig, regs, oldset);
426 else
427 err = setup_frame(ksig, regs, oldset);
428 signal_setup_done(err, ksig, 0);
429}
430
431static inline void syscall_restart(unsigned long orig_i0, struct pt_regs *regs,
432 struct sigaction *sa)
433{
434 switch(regs->u_regs[UREG_I0]) {
435 case ERESTART_RESTARTBLOCK:
436 case ERESTARTNOHAND:
437 no_system_call_restart:
438 regs->u_regs[UREG_I0] = EINTR;
439 regs->psr |= PSR_C;
440 break;
441 case ERESTARTSYS:
442 if (!(sa->sa_flags & SA_RESTART))
443 goto no_system_call_restart;
444 /* fallthrough */
445 case ERESTARTNOINTR:
446 regs->u_regs[UREG_I0] = orig_i0;
447 regs->pc -= 4;
448 regs->npc -= 4;
449 }
450}
451
452/* Note that 'init' is a special process: it doesn't get signals it doesn't
453 * want to handle. Thus you cannot kill init even with a SIGKILL even by
454 * mistake.
455 */
456static void do_signal(struct pt_regs *regs, unsigned long orig_i0)
457{
458 struct ksignal ksig;
459 int restart_syscall;
460 bool has_handler;
461
462 /* It's a lot of work and synchronization to add a new ptrace
463 * register for GDB to save and restore in order to get
464 * orig_i0 correct for syscall restarts when debugging.
465 *
466 * Although it should be the case that most of the global
467 * registers are volatile across a system call, glibc already
468 * depends upon that fact that we preserve them. So we can't
469 * just use any global register to save away the orig_i0 value.
470 *
471 * In particular %g2, %g3, %g4, and %g5 are all assumed to be
472 * preserved across a system call trap by various pieces of
473 * code in glibc.
474 *
475 * %g7 is used as the "thread register". %g6 is not used in
476 * any fixed manner. %g6 is used as a scratch register and
477 * a compiler temporary, but it's value is never used across
478 * a system call. Therefore %g6 is usable for orig_i0 storage.
479 */
480 if (pt_regs_is_syscall(regs) && (regs->psr & PSR_C))
481 regs->u_regs[UREG_G6] = orig_i0;
482
483 has_handler = get_signal(&ksig);
484
485 /* If the debugger messes with the program counter, it clears
486 * the software "in syscall" bit, directing us to not perform
487 * a syscall restart.
488 */
489 restart_syscall = 0;
490 if (pt_regs_is_syscall(regs) && (regs->psr & PSR_C)) {
491 restart_syscall = 1;
492 orig_i0 = regs->u_regs[UREG_G6];
493 }
494
495 if (has_handler) {
496 if (restart_syscall)
497 syscall_restart(orig_i0, regs, &ksig.ka.sa);
498 handle_signal(&ksig, regs);
499 } else {
500 if (restart_syscall) {
501 switch (regs->u_regs[UREG_I0]) {
502 case ERESTARTNOHAND:
503 case ERESTARTSYS:
504 case ERESTARTNOINTR:
505 /* replay the system call when we are done */
506 regs->u_regs[UREG_I0] = orig_i0;
507 regs->pc -= 4;
508 regs->npc -= 4;
509 pt_regs_clear_syscall(regs);
510 case ERESTART_RESTARTBLOCK:
511 regs->u_regs[UREG_G1] = __NR_restart_syscall;
512 regs->pc -= 4;
513 regs->npc -= 4;
514 pt_regs_clear_syscall(regs);
515 }
516 }
517 restore_saved_sigmask();
518 }
519}
520
521void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0,
522 unsigned long thread_info_flags)
523{
524 if (thread_info_flags & _TIF_SIGPENDING)
525 do_signal(regs, orig_i0);
526 if (thread_info_flags & _TIF_NOTIFY_RESUME) {
527 clear_thread_flag(TIF_NOTIFY_RESUME);
528 tracehook_notify_resume(regs);
529 }
530}
531
532asmlinkage int do_sys_sigstack(struct sigstack __user *ssptr,
533 struct sigstack __user *ossptr,
534 unsigned long sp)
535{
536 int ret = -EFAULT;
537
538 /* First see if old state is wanted. */
539 if (ossptr) {
540 if (put_user(current->sas_ss_sp + current->sas_ss_size,
541 &ossptr->the_stack) ||
542 __put_user(on_sig_stack(sp), &ossptr->cur_status))
543 goto out;
544 }
545
546 /* Now see if we want to update the new state. */
547 if (ssptr) {
548 char *ss_sp;
549
550 if (get_user(ss_sp, &ssptr->the_stack))
551 goto out;
552 /* If the current stack was set with sigaltstack, don't
553 swap stacks while we are on it. */
554 ret = -EPERM;
555 if (current->sas_ss_sp && on_sig_stack(sp))
556 goto out;
557
558 /* Since we don't know the extent of the stack, and we don't
559 track onstack-ness, but rather calculate it, we must
560 presume a size. Ho hum this interface is lossy. */
561 current->sas_ss_sp = (unsigned long)ss_sp - SIGSTKSZ;
562 current->sas_ss_size = SIGSTKSZ;
563 }
564 ret = 0;
565out:
566 return ret;
567}