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