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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// SPDX-License-Identifier: GPL-2.0
2/* linux/arch/sparc/kernel/signal.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
6 * Copyright (C) 1996 Miguel de Icaza (miguel@nuclecu.unam.mx)
7 * Copyright (C) 1997 Eddie C. Dost (ecd@skynet.be)
8 */
9
10#include <linux/sched.h>
11#include <linux/kernel.h>
12#include <linux/signal.h>
13#include <linux/errno.h>
14#include <linux/wait.h>
15#include <linux/ptrace.h>
16#include <linux/unistd.h>
17#include <linux/mm.h>
18#include <linux/tty.h>
19#include <linux/smp.h>
20#include <linux/binfmts.h> /* do_coredum */
21#include <linux/bitops.h>
22#include <linux/resume_user_mode.h>
23
24#include <linux/uaccess.h>
25#include <asm/ptrace.h>
26#include <asm/cacheflush.h> /* flush_sig_insns */
27#include <asm/switch_to.h>
28
29#include "sigutil.h"
30#include "kernel.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
62/* Checks if the fp is valid. We always build signal frames which are
63 * 16-byte aligned, therefore we can always enforce that the restore
64 * frame has that property as well.
65 */
66static inline bool invalid_frame_pointer(void __user *fp, int fplen)
67{
68 if ((((unsigned long) fp) & 15) || !access_ok(fp, fplen))
69 return true;
70
71 return false;
72}
73
74asmlinkage void do_sigreturn(struct pt_regs *regs)
75{
76 unsigned long up_psr, pc, npc, ufp;
77 struct signal_frame __user *sf;
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->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 (invalid_frame_pointer(sf, sizeof(*sf)))
92 goto segv_and_exit;
93
94 if (get_user(ufp, &sf->info.si_regs.u_regs[UREG_FP]))
95 goto segv_and_exit;
96
97 if (ufp & 0x7)
98 goto segv_and_exit;
99
100 err = __get_user(pc, &sf->info.si_regs.pc);
101 err |= __get_user(npc, &sf->info.si_regs.npc);
102
103 if ((pc | npc) & 3)
104 goto segv_and_exit;
105
106 /* 2. Restore the state */
107 up_psr = regs->psr;
108 err |= __copy_from_user(regs, &sf->info.si_regs, sizeof(struct pt_regs));
109
110 /* User can only change condition codes and FPU enabling in %psr. */
111 regs->psr = (up_psr & ~(PSR_ICC | PSR_EF))
112 | (regs->psr & (PSR_ICC | PSR_EF));
113
114 /* Prevent syscall restart. */
115 pt_regs_clear_syscall(regs);
116
117 err |= __get_user(fpu_save, &sf->fpu_save);
118 if (fpu_save)
119 err |= restore_fpu_state(regs, fpu_save);
120 err |= __get_user(rwin_save, &sf->rwin_save);
121 if (rwin_save)
122 err |= restore_rwin_state(rwin_save);
123
124 /* This is pretty much atomic, no amount locking would prevent
125 * the races which exist anyways.
126 */
127 err |= __get_user(set.sig[0], &sf->info.si_mask);
128 err |= __copy_from_user(&set.sig[1], &sf->extramask,
129 (_NSIG_WORDS-1) * sizeof(unsigned int));
130
131 if (err)
132 goto segv_and_exit;
133
134 set_current_blocked(&set);
135 return;
136
137segv_and_exit:
138 force_sig(SIGSEGV);
139}
140
141asmlinkage void do_rt_sigreturn(struct pt_regs *regs)
142{
143 struct rt_signal_frame __user *sf;
144 unsigned int psr, pc, npc, ufp;
145 __siginfo_fpu_t __user *fpu_save;
146 __siginfo_rwin_t __user *rwin_save;
147 sigset_t set;
148 int err;
149
150 synchronize_user_stack();
151 sf = (struct rt_signal_frame __user *) regs->u_regs[UREG_FP];
152 if (invalid_frame_pointer(sf, sizeof(*sf)))
153 goto segv;
154
155 if (get_user(ufp, &sf->regs.u_regs[UREG_FP]))
156 goto segv;
157
158 if (ufp & 0x7)
159 goto segv;
160
161 err = __get_user(pc, &sf->regs.pc);
162 err |= __get_user(npc, &sf->regs.npc);
163 err |= ((pc | npc) & 0x03);
164
165 err |= __get_user(regs->y, &sf->regs.y);
166 err |= __get_user(psr, &sf->regs.psr);
167
168 err |= __copy_from_user(®s->u_regs[UREG_G1],
169 &sf->regs.u_regs[UREG_G1], 15 * sizeof(u32));
170
171 regs->psr = (regs->psr & ~PSR_ICC) | (psr & PSR_ICC);
172
173 /* Prevent syscall restart. */
174 pt_regs_clear_syscall(regs);
175
176 err |= __get_user(fpu_save, &sf->fpu_save);
177 if (!err && fpu_save)
178 err |= restore_fpu_state(regs, fpu_save);
179 err |= __copy_from_user(&set, &sf->mask, sizeof(sigset_t));
180 err |= restore_altstack(&sf->stack);
181
182 if (err)
183 goto segv;
184
185 regs->pc = pc;
186 regs->npc = npc;
187
188 err |= __get_user(rwin_save, &sf->rwin_save);
189 if (!err && rwin_save) {
190 if (restore_rwin_state(rwin_save))
191 goto segv;
192 }
193
194 set_current_blocked(&set);
195 return;
196segv:
197 force_sig(SIGSEGV);
198}
199
200static inline void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs, unsigned long framesize)
201{
202 unsigned long sp = regs->u_regs[UREG_FP];
203
204 /*
205 * If we are on the alternate signal stack and would overflow it, don't.
206 * Return an always-bogus address instead so we will die with SIGSEGV.
207 */
208 if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize)))
209 return (void __user *) -1L;
210
211 /* This is the X/Open sanctioned signal stack switching. */
212 sp = sigsp(sp, ksig) - framesize;
213
214 /* Always align the stack frame. This handles two cases. First,
215 * sigaltstack need not be mindful of platform specific stack
216 * alignment. Second, if we took this signal because the stack
217 * is not aligned properly, we'd like to take the signal cleanly
218 * and report that.
219 */
220 sp &= ~15UL;
221
222 return (void __user *) sp;
223}
224
225static int setup_frame(struct ksignal *ksig, struct pt_regs *regs,
226 sigset_t *oldset)
227{
228 struct signal_frame __user *sf;
229 int sigframe_size, err, wsaved;
230 void __user *tail;
231
232 /* 1. Make sure everything is clean */
233 synchronize_user_stack();
234
235 wsaved = current_thread_info()->w_saved;
236
237 sigframe_size = sizeof(*sf);
238 if (used_math())
239 sigframe_size += sizeof(__siginfo_fpu_t);
240 if (wsaved)
241 sigframe_size += sizeof(__siginfo_rwin_t);
242
243 sf = (struct signal_frame __user *)
244 get_sigframe(ksig, regs, sigframe_size);
245
246 if (invalid_frame_pointer(sf, sigframe_size)) {
247 force_exit_sig(SIGILL);
248 return -EINVAL;
249 }
250
251 tail = sf + 1;
252
253 /* 2. Save the current process state */
254 err = __copy_to_user(&sf->info.si_regs, regs, sizeof(struct pt_regs));
255
256 err |= __put_user(0, &sf->extra_size);
257
258 if (used_math()) {
259 __siginfo_fpu_t __user *fp = tail;
260 tail += sizeof(*fp);
261 err |= save_fpu_state(regs, fp);
262 err |= __put_user(fp, &sf->fpu_save);
263 } else {
264 err |= __put_user(0, &sf->fpu_save);
265 }
266 if (wsaved) {
267 __siginfo_rwin_t __user *rwp = tail;
268 tail += sizeof(*rwp);
269 err |= save_rwin_state(wsaved, rwp);
270 err |= __put_user(rwp, &sf->rwin_save);
271 } else {
272 err |= __put_user(0, &sf->rwin_save);
273 }
274
275 err |= __put_user(oldset->sig[0], &sf->info.si_mask);
276 err |= __copy_to_user(sf->extramask, &oldset->sig[1],
277 (_NSIG_WORDS - 1) * sizeof(unsigned int));
278 if (!wsaved) {
279 err |= __copy_to_user(sf, (char *) regs->u_regs[UREG_FP],
280 sizeof(struct reg_window32));
281 } else {
282 struct reg_window32 *rp;
283
284 rp = ¤t_thread_info()->reg_window[wsaved - 1];
285 err |= __copy_to_user(sf, rp, sizeof(struct reg_window32));
286 }
287 if (err)
288 return err;
289
290 /* 3. signal handler back-trampoline and parameters */
291 regs->u_regs[UREG_FP] = (unsigned long) sf;
292 regs->u_regs[UREG_I0] = ksig->sig;
293 regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
294 regs->u_regs[UREG_I2] = (unsigned long) &sf->info;
295
296 /* 4. signal handler */
297 regs->pc = (unsigned long) ksig->ka.sa.sa_handler;
298 regs->npc = (regs->pc + 4);
299
300 /* 5. return to kernel instructions */
301 if (ksig->ka.ka_restorer)
302 regs->u_regs[UREG_I7] = (unsigned long)ksig->ka.ka_restorer;
303 else {
304 regs->u_regs[UREG_I7] = (unsigned long)(&(sf->insns[0]) - 2);
305
306 /* mov __NR_sigreturn, %g1 */
307 err |= __put_user(0x821020d8, &sf->insns[0]);
308
309 /* t 0x10 */
310 err |= __put_user(0x91d02010, &sf->insns[1]);
311 if (err)
312 return err;
313
314 /* Flush instruction space. */
315 flush_sig_insns(current->mm, (unsigned long) &(sf->insns[0]));
316 }
317 return 0;
318}
319
320static int setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs,
321 sigset_t *oldset)
322{
323 struct rt_signal_frame __user *sf;
324 int sigframe_size, wsaved;
325 void __user *tail;
326 unsigned int psr;
327 int err;
328
329 synchronize_user_stack();
330 wsaved = current_thread_info()->w_saved;
331 sigframe_size = sizeof(*sf);
332 if (used_math())
333 sigframe_size += sizeof(__siginfo_fpu_t);
334 if (wsaved)
335 sigframe_size += sizeof(__siginfo_rwin_t);
336 sf = (struct rt_signal_frame __user *)
337 get_sigframe(ksig, regs, sigframe_size);
338 if (invalid_frame_pointer(sf, sigframe_size)) {
339 force_exit_sig(SIGILL);
340 return -EINVAL;
341 }
342
343 tail = sf + 1;
344 err = __put_user(regs->pc, &sf->regs.pc);
345 err |= __put_user(regs->npc, &sf->regs.npc);
346 err |= __put_user(regs->y, &sf->regs.y);
347 psr = regs->psr;
348 if (used_math())
349 psr |= PSR_EF;
350 err |= __put_user(psr, &sf->regs.psr);
351 err |= __copy_to_user(&sf->regs.u_regs, regs->u_regs, sizeof(regs->u_regs));
352 err |= __put_user(0, &sf->extra_size);
353
354 if (psr & PSR_EF) {
355 __siginfo_fpu_t __user *fp = tail;
356 tail += sizeof(*fp);
357 err |= save_fpu_state(regs, fp);
358 err |= __put_user(fp, &sf->fpu_save);
359 } else {
360 err |= __put_user(0, &sf->fpu_save);
361 }
362 if (wsaved) {
363 __siginfo_rwin_t __user *rwp = tail;
364 tail += sizeof(*rwp);
365 err |= save_rwin_state(wsaved, rwp);
366 err |= __put_user(rwp, &sf->rwin_save);
367 } else {
368 err |= __put_user(0, &sf->rwin_save);
369 }
370 err |= __copy_to_user(&sf->mask, &oldset->sig[0], sizeof(sigset_t));
371
372 /* Setup sigaltstack */
373 err |= __save_altstack(&sf->stack, regs->u_regs[UREG_FP]);
374
375 if (!wsaved) {
376 err |= __copy_to_user(sf, (char *) regs->u_regs[UREG_FP],
377 sizeof(struct reg_window32));
378 } else {
379 struct reg_window32 *rp;
380
381 rp = ¤t_thread_info()->reg_window[wsaved - 1];
382 err |= __copy_to_user(sf, rp, sizeof(struct reg_window32));
383 }
384
385 err |= copy_siginfo_to_user(&sf->info, &ksig->info);
386
387 if (err)
388 return err;
389
390 regs->u_regs[UREG_FP] = (unsigned long) sf;
391 regs->u_regs[UREG_I0] = ksig->sig;
392 regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
393 regs->u_regs[UREG_I2] = (unsigned long) &sf->regs;
394
395 regs->pc = (unsigned long) ksig->ka.sa.sa_handler;
396 regs->npc = (regs->pc + 4);
397
398 if (ksig->ka.ka_restorer)
399 regs->u_regs[UREG_I7] = (unsigned long)ksig->ka.ka_restorer;
400 else {
401 regs->u_regs[UREG_I7] = (unsigned long)(&(sf->insns[0]) - 2);
402
403 /* mov __NR_rt_sigreturn, %g1 */
404 err |= __put_user(0x82102065, &sf->insns[0]);
405
406 /* t 0x10 */
407 err |= __put_user(0x91d02010, &sf->insns[1]);
408 if (err)
409 return err;
410
411 /* Flush instruction space. */
412 flush_sig_insns(current->mm, (unsigned long) &(sf->insns[0]));
413 }
414 return 0;
415}
416
417static inline void
418handle_signal(struct ksignal *ksig, struct pt_regs *regs)
419{
420 sigset_t *oldset = sigmask_to_save();
421 int err;
422
423 if (ksig->ka.sa.sa_flags & SA_SIGINFO)
424 err = setup_rt_frame(ksig, regs, oldset);
425 else
426 err = setup_frame(ksig, regs, oldset);
427 signal_setup_done(err, ksig, 0);
428}
429
430static inline void syscall_restart(unsigned long orig_i0, struct pt_regs *regs,
431 struct sigaction *sa)
432{
433 switch(regs->u_regs[UREG_I0]) {
434 case ERESTART_RESTARTBLOCK:
435 case ERESTARTNOHAND:
436 no_system_call_restart:
437 regs->u_regs[UREG_I0] = EINTR;
438 regs->psr |= PSR_C;
439 break;
440 case ERESTARTSYS:
441 if (!(sa->sa_flags & SA_RESTART))
442 goto no_system_call_restart;
443 fallthrough;
444 case ERESTARTNOINTR:
445 regs->u_regs[UREG_I0] = orig_i0;
446 regs->pc -= 4;
447 regs->npc -= 4;
448 }
449}
450
451/* Note that 'init' is a special process: it doesn't get signals it doesn't
452 * want to handle. Thus you cannot kill init even with a SIGKILL even by
453 * mistake.
454 */
455static void do_signal(struct pt_regs *regs, unsigned long orig_i0)
456{
457 struct ksignal ksig;
458 int restart_syscall;
459 bool has_handler;
460
461 /* It's a lot of work and synchronization to add a new ptrace
462 * register for GDB to save and restore in order to get
463 * orig_i0 correct for syscall restarts when debugging.
464 *
465 * Although it should be the case that most of the global
466 * registers are volatile across a system call, glibc already
467 * depends upon that fact that we preserve them. So we can't
468 * just use any global register to save away the orig_i0 value.
469 *
470 * In particular %g2, %g3, %g4, and %g5 are all assumed to be
471 * preserved across a system call trap by various pieces of
472 * code in glibc.
473 *
474 * %g7 is used as the "thread register". %g6 is not used in
475 * any fixed manner. %g6 is used as a scratch register and
476 * a compiler temporary, but it's value is never used across
477 * a system call. Therefore %g6 is usable for orig_i0 storage.
478 */
479 if (pt_regs_is_syscall(regs) && (regs->psr & PSR_C))
480 regs->u_regs[UREG_G6] = orig_i0;
481
482 has_handler = get_signal(&ksig);
483
484 /* If the debugger messes with the program counter, it clears
485 * the software "in syscall" bit, directing us to not perform
486 * a syscall restart.
487 */
488 restart_syscall = 0;
489 if (pt_regs_is_syscall(regs) && (regs->psr & PSR_C)) {
490 restart_syscall = 1;
491 orig_i0 = regs->u_regs[UREG_G6];
492 }
493
494 if (has_handler) {
495 if (restart_syscall)
496 syscall_restart(orig_i0, regs, &ksig.ka.sa);
497 handle_signal(&ksig, regs);
498 } else {
499 if (restart_syscall) {
500 switch (regs->u_regs[UREG_I0]) {
501 case ERESTARTNOHAND:
502 case ERESTARTSYS:
503 case ERESTARTNOINTR:
504 /* replay the system call when we are done */
505 regs->u_regs[UREG_I0] = orig_i0;
506 regs->pc -= 4;
507 regs->npc -= 4;
508 pt_regs_clear_syscall(regs);
509 fallthrough;
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 | _TIF_NOTIFY_SIGNAL))
525 do_signal(regs, orig_i0);
526 if (thread_info_flags & _TIF_NOTIFY_RESUME)
527 resume_user_mode_work(regs);
528}
529
530asmlinkage int do_sys_sigstack(struct sigstack __user *ssptr,
531 struct sigstack __user *ossptr,
532 unsigned long sp)
533{
534 int ret = -EFAULT;
535
536 /* First see if old state is wanted. */
537 if (ossptr) {
538 if (put_user(current->sas_ss_sp + current->sas_ss_size,
539 &ossptr->the_stack) ||
540 __put_user(on_sig_stack(sp), &ossptr->cur_status))
541 goto out;
542 }
543
544 /* Now see if we want to update the new state. */
545 if (ssptr) {
546 char *ss_sp;
547
548 if (get_user(ss_sp, &ssptr->the_stack))
549 goto out;
550 /* If the current stack was set with sigaltstack, don't
551 swap stacks while we are on it. */
552 ret = -EPERM;
553 if (current->sas_ss_sp && on_sig_stack(sp))
554 goto out;
555
556 /* Since we don't know the extent of the stack, and we don't
557 track onstack-ness, but rather calculate it, we must
558 presume a size. Ho hum this interface is lossy. */
559 current->sas_ss_sp = (unsigned long)ss_sp - SIGSTKSZ;
560 current->sas_ss_size = SIGSTKSZ;
561 }
562 ret = 0;
563out:
564 return ret;
565}