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