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Add linux-next specific files for 20110831
[linux-2.6/next.git] / arch / arm / kernel / signal.c
blobd13e61ac18dab0120a59a412e32dc8fd9295bf0a
1 /*
2 * linux/arch/arm/kernel/signal.c
3 *
4 * Copyright (C) 1995-2009 Russell King
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10 #include <linux/errno.h>
11 #include <linux/signal.h>
12 #include <linux/personality.h>
13 #include <linux/freezer.h>
14 #include <linux/uaccess.h>
15 #include <linux/tracehook.h>
16
17 #include <asm/elf.h>
18 #include <asm/cacheflush.h>
19 #include <asm/ucontext.h>
20 #include <asm/unistd.h>
21 #include <asm/vfp.h>
22
23 #include "signal.h"
24
25 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
26
27 /*
28 * For ARM syscalls, we encode the syscall number into the instruction.
29 */
30 #define SWI_SYS_SIGRETURN (0xef000000|(__NR_sigreturn)|(__NR_OABI_SYSCALL_BASE))
31 #define SWI_SYS_RT_SIGRETURN (0xef000000|(__NR_rt_sigreturn)|(__NR_OABI_SYSCALL_BASE))
32 #define SWI_SYS_RESTART (0xef000000|__NR_restart_syscall|__NR_OABI_SYSCALL_BASE)
33
34 /*
35 * With EABI, the syscall number has to be loaded into r7.
36 */
37 #define MOV_R7_NR_SIGRETURN (0xe3a07000 | (__NR_sigreturn - __NR_SYSCALL_BASE))
38 #define MOV_R7_NR_RT_SIGRETURN (0xe3a07000 | (__NR_rt_sigreturn - __NR_SYSCALL_BASE))
39
40 /*
41 * For Thumb syscalls, we pass the syscall number via r7. We therefore
42 * need two 16-bit instructions.
43 */
44 #define SWI_THUMB_SIGRETURN (0xdf00 << 16 | 0x2700 | (__NR_sigreturn - __NR_SYSCALL_BASE))
45 #define SWI_THUMB_RT_SIGRETURN (0xdf00 << 16 | 0x2700 | (__NR_rt_sigreturn - __NR_SYSCALL_BASE))
46
47 const unsigned long sigreturn_codes[7] = {
48 MOV_R7_NR_SIGRETURN, SWI_SYS_SIGRETURN, SWI_THUMB_SIGRETURN,
49 MOV_R7_NR_RT_SIGRETURN, SWI_SYS_RT_SIGRETURN, SWI_THUMB_RT_SIGRETURN,
50 };
51
52 /*
53 * Either we support OABI only, or we have EABI with the OABI
54 * compat layer enabled. In the later case we don't know if
55 * user space is EABI or not, and if not we must not clobber r7.
56 * Always using the OABI syscall solves that issue and works for
57 * all those cases.
58 */
59 const unsigned long syscall_restart_code[2] = {
60 SWI_SYS_RESTART, /* swi __NR_restart_syscall */
61 0xe49df004, /* ldr pc, [sp], #4 */
62 };
63
64 /*
65 * atomically swap in the new signal mask, and wait for a signal.
66 */
67 asmlinkage int sys_sigsuspend(int restart, unsigned long oldmask, old_sigset_t mask)
68 {
69 sigset_t blocked;
70
71 current->saved_sigmask = current->blocked;
72
73 mask &= _BLOCKABLE;
74 siginitset(&blocked, mask);
75 set_current_blocked(&blocked);
76
77 current->state = TASK_INTERRUPTIBLE;
78 schedule();
79 set_restore_sigmask();
80 return -ERESTARTNOHAND;
81 }
82
83 asmlinkage int
84 sys_sigaction(int sig, const struct old_sigaction __user *act,
85 struct old_sigaction __user *oact)
86 {
87 struct k_sigaction new_ka, old_ka;
88 int ret;
89
90 if (act) {
91 old_sigset_t mask;
92 if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
93 __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
94 __get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
95 return -EFAULT;
96 __get_user(new_ka.sa.sa_flags, &act->sa_flags);
97 __get_user(mask, &act->sa_mask);
98 siginitset(&new_ka.sa.sa_mask, mask);
99 }
100
101 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
102
103 if (!ret && oact) {
104 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
105 __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
106 __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
107 return -EFAULT;
108 __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
109 __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
110 }
111
112 return ret;
113 }
114
115 #ifdef CONFIG_CRUNCH
116 static int preserve_crunch_context(struct crunch_sigframe __user *frame)
117 {
118 char kbuf[sizeof(*frame) + 8];
119 struct crunch_sigframe *kframe;
120
121 /* the crunch context must be 64 bit aligned */
122 kframe = (struct crunch_sigframe *)((unsigned long)(kbuf + 8) & ~7);
123 kframe->magic = CRUNCH_MAGIC;
124 kframe->size = CRUNCH_STORAGE_SIZE;
125 crunch_task_copy(current_thread_info(), &kframe->storage);
126 return __copy_to_user(frame, kframe, sizeof(*frame));
127 }
128
129 static int restore_crunch_context(struct crunch_sigframe __user *frame)
130 {
131 char kbuf[sizeof(*frame) + 8];
132 struct crunch_sigframe *kframe;
133
134 /* the crunch context must be 64 bit aligned */
135 kframe = (struct crunch_sigframe *)((unsigned long)(kbuf + 8) & ~7);
136 if (__copy_from_user(kframe, frame, sizeof(*frame)))
137 return -1;
138 if (kframe->magic != CRUNCH_MAGIC ||
139 kframe->size != CRUNCH_STORAGE_SIZE)
140 return -1;
141 crunch_task_restore(current_thread_info(), &kframe->storage);
142 return 0;
143 }
144 #endif
145
146 #ifdef CONFIG_IWMMXT
147
148 static int preserve_iwmmxt_context(struct iwmmxt_sigframe *frame)
149 {
150 char kbuf[sizeof(*frame) + 8];
151 struct iwmmxt_sigframe *kframe;
152
153 /* the iWMMXt context must be 64 bit aligned */
154 kframe = (struct iwmmxt_sigframe *)((unsigned long)(kbuf + 8) & ~7);
155 kframe->magic = IWMMXT_MAGIC;
156 kframe->size = IWMMXT_STORAGE_SIZE;
157 iwmmxt_task_copy(current_thread_info(), &kframe->storage);
158 return __copy_to_user(frame, kframe, sizeof(*frame));
159 }
160
161 static int restore_iwmmxt_context(struct iwmmxt_sigframe *frame)
162 {
163 char kbuf[sizeof(*frame) + 8];
164 struct iwmmxt_sigframe *kframe;
165
166 /* the iWMMXt context must be 64 bit aligned */
167 kframe = (struct iwmmxt_sigframe *)((unsigned long)(kbuf + 8) & ~7);
168 if (__copy_from_user(kframe, frame, sizeof(*frame)))
169 return -1;
170 if (kframe->magic != IWMMXT_MAGIC ||
171 kframe->size != IWMMXT_STORAGE_SIZE)
172 return -1;
173 iwmmxt_task_restore(current_thread_info(), &kframe->storage);
174 return 0;
175 }
176
177 #endif
178
179 #ifdef CONFIG_VFP
180
181 static int preserve_vfp_context(struct vfp_sigframe __user *frame)
182 {
183 struct thread_info *thread = current_thread_info();
184 struct vfp_hard_struct *h = &thread->vfpstate.hard;
185 const unsigned long magic = VFP_MAGIC;
186 const unsigned long size = VFP_STORAGE_SIZE;
187 int err = 0;
188
189 vfp_sync_hwstate(thread);
190 __put_user_error(magic, &frame->magic, err);
191 __put_user_error(size, &frame->size, err);
192
193 /*
194 * Copy the floating point registers. There can be unused
195 * registers see asm/hwcap.h for details.
196 */
197 err |= __copy_to_user(&frame->ufp.fpregs, &h->fpregs,
198 sizeof(h->fpregs));
199 /*
200 * Copy the status and control register.
201 */
202 __put_user_error(h->fpscr, &frame->ufp.fpscr, err);
203
204 /*
205 * Copy the exception registers.
206 */
207 __put_user_error(h->fpexc, &frame->ufp_exc.fpexc, err);
208 __put_user_error(h->fpinst, &frame->ufp_exc.fpinst, err);
209 __put_user_error(h->fpinst2, &frame->ufp_exc.fpinst2, err);
210
211 return err ? -EFAULT : 0;
212 }
213
214 static int restore_vfp_context(struct vfp_sigframe __user *frame)
215 {
216 struct thread_info *thread = current_thread_info();
217 struct vfp_hard_struct *h = &thread->vfpstate.hard;
218 unsigned long magic;
219 unsigned long size;
220 unsigned long fpexc;
221 int err = 0;
222
223 __get_user_error(magic, &frame->magic, err);
224 __get_user_error(size, &frame->size, err);
225
226 if (err)
227 return -EFAULT;
228 if (magic != VFP_MAGIC || size != VFP_STORAGE_SIZE)
229 return -EINVAL;
230
231 /*
232 * Copy the floating point registers. There can be unused
233 * registers see asm/hwcap.h for details.
234 */
235 err |= __copy_from_user(&h->fpregs, &frame->ufp.fpregs,
236 sizeof(h->fpregs));
237 /*
238 * Copy the status and control register.
239 */
240 __get_user_error(h->fpscr, &frame->ufp.fpscr, err);
241
242 /*
243 * Sanitise and restore the exception registers.
244 */
245 __get_user_error(fpexc, &frame->ufp_exc.fpexc, err);
246 /* Ensure the VFP is enabled. */
247 fpexc |= FPEXC_EN;
248 /* Ensure FPINST2 is invalid and the exception flag is cleared. */
249 fpexc &= ~(FPEXC_EX | FPEXC_FP2V);
250 h->fpexc = fpexc;
251
252 __get_user_error(h->fpinst, &frame->ufp_exc.fpinst, err);
253 __get_user_error(h->fpinst2, &frame->ufp_exc.fpinst2, err);
254
255 if (!err)
256 vfp_flush_hwstate(thread);
257
258 return err ? -EFAULT : 0;
259 }
260
261 #endif
262
263 /*
264 * Do a signal return; undo the signal stack. These are aligned to 64-bit.
265 */
266 struct sigframe {
267 struct ucontext uc;
268 unsigned long retcode[2];
269 };
270
271 struct rt_sigframe {
272 struct siginfo info;
273 struct sigframe sig;
274 };
275
276 static int restore_sigframe(struct pt_regs *regs, struct sigframe __user *sf)
277 {
278 struct aux_sigframe __user *aux;
279 sigset_t set;
280 int err;
281
282 err = __copy_from_user(&set, &sf->uc.uc_sigmask, sizeof(set));
283 if (err == 0) {
284 sigdelsetmask(&set, ~_BLOCKABLE);
285 set_current_blocked(&set);
286 }
287
288 __get_user_error(regs->ARM_r0, &sf->uc.uc_mcontext.arm_r0, err);
289 __get_user_error(regs->ARM_r1, &sf->uc.uc_mcontext.arm_r1, err);
290 __get_user_error(regs->ARM_r2, &sf->uc.uc_mcontext.arm_r2, err);
291 __get_user_error(regs->ARM_r3, &sf->uc.uc_mcontext.arm_r3, err);
292 __get_user_error(regs->ARM_r4, &sf->uc.uc_mcontext.arm_r4, err);
293 __get_user_error(regs->ARM_r5, &sf->uc.uc_mcontext.arm_r5, err);
294 __get_user_error(regs->ARM_r6, &sf->uc.uc_mcontext.arm_r6, err);
295 __get_user_error(regs->ARM_r7, &sf->uc.uc_mcontext.arm_r7, err);
296 __get_user_error(regs->ARM_r8, &sf->uc.uc_mcontext.arm_r8, err);
297 __get_user_error(regs->ARM_r9, &sf->uc.uc_mcontext.arm_r9, err);
298 __get_user_error(regs->ARM_r10, &sf->uc.uc_mcontext.arm_r10, err);
299 __get_user_error(regs->ARM_fp, &sf->uc.uc_mcontext.arm_fp, err);
300 __get_user_error(regs->ARM_ip, &sf->uc.uc_mcontext.arm_ip, err);
301 __get_user_error(regs->ARM_sp, &sf->uc.uc_mcontext.arm_sp, err);
302 __get_user_error(regs->ARM_lr, &sf->uc.uc_mcontext.arm_lr, err);
303 __get_user_error(regs->ARM_pc, &sf->uc.uc_mcontext.arm_pc, err);
304 __get_user_error(regs->ARM_cpsr, &sf->uc.uc_mcontext.arm_cpsr, err);
305
306 err |= !valid_user_regs(regs);
307
308 aux = (struct aux_sigframe __user *) sf->uc.uc_regspace;
309 #ifdef CONFIG_CRUNCH
310 if (err == 0)
311 err |= restore_crunch_context(&aux->crunch);
312 #endif
313 #ifdef CONFIG_IWMMXT
314 if (err == 0 && test_thread_flag(TIF_USING_IWMMXT))
315 err |= restore_iwmmxt_context(&aux->iwmmxt);
316 #endif
317 #ifdef CONFIG_VFP
318 if (err == 0)
319 err |= restore_vfp_context(&aux->vfp);
320 #endif
321
322 return err;
323 }
324
325 asmlinkage int sys_sigreturn(struct pt_regs *regs)
326 {
327 struct sigframe __user *frame;
328
329 /* Always make any pending restarted system calls return -EINTR */
330 current_thread_info()->restart_block.fn = do_no_restart_syscall;
331
332 /*
333 * Since we stacked the signal on a 64-bit boundary,
334 * then 'sp' should be word aligned here. If it's
335 * not, then the user is trying to mess with us.
336 */
337 if (regs->ARM_sp & 7)
338 goto badframe;
339
340 frame = (struct sigframe __user *)regs->ARM_sp;
341
342 if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
343 goto badframe;
344
345 if (restore_sigframe(regs, frame))
346 goto badframe;
347
348 return regs->ARM_r0;
349
350 badframe:
351 force_sig(SIGSEGV, current);
352 return 0;
353 }
354
355 asmlinkage int sys_rt_sigreturn(struct pt_regs *regs)
356 {
357 struct rt_sigframe __user *frame;
358
359 /* Always make any pending restarted system calls return -EINTR */
360 current_thread_info()->restart_block.fn = do_no_restart_syscall;
361
362 /*
363 * Since we stacked the signal on a 64-bit boundary,
364 * then 'sp' should be word aligned here. If it's
365 * not, then the user is trying to mess with us.
366 */
367 if (regs->ARM_sp & 7)
368 goto badframe;
369
370 frame = (struct rt_sigframe __user *)regs->ARM_sp;
371
372 if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
373 goto badframe;
374
375 if (restore_sigframe(regs, &frame->sig))
376 goto badframe;
377
378 if (do_sigaltstack(&frame->sig.uc.uc_stack, NULL, regs->ARM_sp) == -EFAULT)
379 goto badframe;
380
381 return regs->ARM_r0;
382
383 badframe:
384 force_sig(SIGSEGV, current);
385 return 0;
386 }
387
388 static int
389 setup_sigframe(struct sigframe __user *sf, struct pt_regs *regs, sigset_t *set)
390 {
391 struct aux_sigframe __user *aux;
392 int err = 0;
393
394 __put_user_error(regs->ARM_r0, &sf->uc.uc_mcontext.arm_r0, err);
395 __put_user_error(regs->ARM_r1, &sf->uc.uc_mcontext.arm_r1, err);
396 __put_user_error(regs->ARM_r2, &sf->uc.uc_mcontext.arm_r2, err);
397 __put_user_error(regs->ARM_r3, &sf->uc.uc_mcontext.arm_r3, err);
398 __put_user_error(regs->ARM_r4, &sf->uc.uc_mcontext.arm_r4, err);
399 __put_user_error(regs->ARM_r5, &sf->uc.uc_mcontext.arm_r5, err);
400 __put_user_error(regs->ARM_r6, &sf->uc.uc_mcontext.arm_r6, err);
401 __put_user_error(regs->ARM_r7, &sf->uc.uc_mcontext.arm_r7, err);
402 __put_user_error(regs->ARM_r8, &sf->uc.uc_mcontext.arm_r8, err);
403 __put_user_error(regs->ARM_r9, &sf->uc.uc_mcontext.arm_r9, err);
404 __put_user_error(regs->ARM_r10, &sf->uc.uc_mcontext.arm_r10, err);
405 __put_user_error(regs->ARM_fp, &sf->uc.uc_mcontext.arm_fp, err);
406 __put_user_error(regs->ARM_ip, &sf->uc.uc_mcontext.arm_ip, err);
407 __put_user_error(regs->ARM_sp, &sf->uc.uc_mcontext.arm_sp, err);
408 __put_user_error(regs->ARM_lr, &sf->uc.uc_mcontext.arm_lr, err);
409 __put_user_error(regs->ARM_pc, &sf->uc.uc_mcontext.arm_pc, err);
410 __put_user_error(regs->ARM_cpsr, &sf->uc.uc_mcontext.arm_cpsr, err);
411
412 __put_user_error(current->thread.trap_no, &sf->uc.uc_mcontext.trap_no, err);
413 __put_user_error(current->thread.error_code, &sf->uc.uc_mcontext.error_code, err);
414 __put_user_error(current->thread.address, &sf->uc.uc_mcontext.fault_address, err);
415 __put_user_error(set->sig[0], &sf->uc.uc_mcontext.oldmask, err);
416
417 err |= __copy_to_user(&sf->uc.uc_sigmask, set, sizeof(*set));
418
419 aux = (struct aux_sigframe __user *) sf->uc.uc_regspace;
420 #ifdef CONFIG_CRUNCH
421 if (err == 0)
422 err |= preserve_crunch_context(&aux->crunch);
423 #endif
424 #ifdef CONFIG_IWMMXT
425 if (err == 0 && test_thread_flag(TIF_USING_IWMMXT))
426 err |= preserve_iwmmxt_context(&aux->iwmmxt);
427 #endif
428 #ifdef CONFIG_VFP
429 if (err == 0)
430 err |= preserve_vfp_context(&aux->vfp);
431 #endif
432 __put_user_error(0, &aux->end_magic, err);
433
434 return err;
435 }
436
437 static inline void __user *
438 get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, int framesize)
439 {
440 unsigned long sp = regs->ARM_sp;
441 void __user *frame;
442
443 /*
444 * This is the X/Open sanctioned signal stack switching.
445 */
446 if ((ka->sa.sa_flags & SA_ONSTACK) && !sas_ss_flags(sp))
447 sp = current->sas_ss_sp + current->sas_ss_size;
448
449 /*
450 * ATPCS B01 mandates 8-byte alignment
451 */
452 frame = (void __user *)((sp - framesize) & ~7);
453
454 /*
455 * Check that we can actually write to the signal frame.
456 */
457 if (!access_ok(VERIFY_WRITE, frame, framesize))
458 frame = NULL;
459
460 return frame;
461 }
462
463 static int
464 setup_return(struct pt_regs *regs, struct k_sigaction *ka,
465 unsigned long __user *rc, void __user *frame, int usig)
466 {
467 unsigned long handler = (unsigned long)ka->sa.sa_handler;
468 unsigned long retcode;
469 int thumb = 0;
470 unsigned long cpsr = regs->ARM_cpsr & ~(PSR_f | PSR_E_BIT);
471
472 cpsr |= PSR_ENDSTATE;
473
474 /*
475 * Maybe we need to deliver a 32-bit signal to a 26-bit task.
476 */
477 if (ka->sa.sa_flags & SA_THIRTYTWO)
478 cpsr = (cpsr & ~MODE_MASK) | USR_MODE;
479
480 #ifdef CONFIG_ARM_THUMB
481 if (elf_hwcap & HWCAP_THUMB) {
482 /*
483 * The LSB of the handler determines if we're going to
484 * be using THUMB or ARM mode for this signal handler.
485 */
486 thumb = handler & 1;
487
488 if (thumb) {
489 cpsr |= PSR_T_BIT;
490 #if __LINUX_ARM_ARCH__ >= 7
491 /* clear the If-Then Thumb-2 execution state */
492 cpsr &= ~PSR_IT_MASK;
493 #endif
494 } else
495 cpsr &= ~PSR_T_BIT;
496 }
497 #endif
498
499 if (ka->sa.sa_flags & SA_RESTORER) {
500 retcode = (unsigned long)ka->sa.sa_restorer;
501 } else {
502 unsigned int idx = thumb << 1;
503
504 if (ka->sa.sa_flags & SA_SIGINFO)
505 idx += 3;
506
507 if (__put_user(sigreturn_codes[idx], rc) ||
508 __put_user(sigreturn_codes[idx+1], rc+1))
509 return 1;
510
511 if (cpsr & MODE32_BIT) {
512 /*
513 * 32-bit code can use the new high-page
514 * signal return code support.
515 */
516 retcode = KERN_SIGRETURN_CODE + (idx << 2) + thumb;
517 } else {
518 /*
519 * Ensure that the instruction cache sees
520 * the return code written onto the stack.
521 */
522 flush_icache_range((unsigned long)rc,
523 (unsigned long)(rc + 2));
524
525 retcode = ((unsigned long)rc) + thumb;
526 }
527 }
528
529 regs->ARM_r0 = usig;
530 regs->ARM_sp = (unsigned long)frame;
531 regs->ARM_lr = retcode;
532 regs->ARM_pc = handler;
533 regs->ARM_cpsr = cpsr;
534
535 return 0;
536 }
537
538 static int
539 setup_frame(int usig, struct k_sigaction *ka, sigset_t *set, struct pt_regs *regs)
540 {
541 struct sigframe __user *frame = get_sigframe(ka, regs, sizeof(*frame));
542 int err = 0;
543
544 if (!frame)
545 return 1;
546
547 /*
548 * Set uc.uc_flags to a value which sc.trap_no would never have.
549 */
550 __put_user_error(0x5ac3c35a, &frame->uc.uc_flags, err);
551
552 err |= setup_sigframe(frame, regs, set);
553 if (err == 0)
554 err = setup_return(regs, ka, frame->retcode, frame, usig);
555
556 return err;
557 }
558
559 static int
560 setup_rt_frame(int usig, struct k_sigaction *ka, siginfo_t *info,
561 sigset_t *set, struct pt_regs *regs)
562 {
563 struct rt_sigframe __user *frame = get_sigframe(ka, regs, sizeof(*frame));
564 stack_t stack;
565 int err = 0;
566
567 if (!frame)
568 return 1;
569
570 err |= copy_siginfo_to_user(&frame->info, info);
571
572 __put_user_error(0, &frame->sig.uc.uc_flags, err);
573 __put_user_error(NULL, &frame->sig.uc.uc_link, err);
574
575 memset(&stack, 0, sizeof(stack));
576 stack.ss_sp = (void __user *)current->sas_ss_sp;
577 stack.ss_flags = sas_ss_flags(regs->ARM_sp);
578 stack.ss_size = current->sas_ss_size;
579 err |= __copy_to_user(&frame->sig.uc.uc_stack, &stack, sizeof(stack));
580
581 err |= setup_sigframe(&frame->sig, regs, set);
582 if (err == 0)
583 err = setup_return(regs, ka, frame->sig.retcode, frame, usig);
584
585 if (err == 0) {
586 /*
587 * For realtime signals we must also set the second and third
588 * arguments for the signal handler.
589 * -- Peter Maydell <pmaydell@chiark.greenend.org.uk> 2000-12-06
590 */
591 regs->ARM_r1 = (unsigned long)&frame->info;
592 regs->ARM_r2 = (unsigned long)&frame->sig.uc;
593 }
594
595 return err;
596 }
597
598 /*
599 * OK, we're invoking a handler
600 */
601 static int
602 handle_signal(unsigned long sig, struct k_sigaction *ka,
603 siginfo_t *info, sigset_t *oldset,
604 struct pt_regs * regs)
605 {
606 struct thread_info *thread = current_thread_info();
607 struct task_struct *tsk = current;
608 int usig = sig;
609 int ret;
610
611 /*
612 * translate the signal
613 */
614 if (usig < 32 && thread->exec_domain && thread->exec_domain->signal_invmap)
615 usig = thread->exec_domain->signal_invmap[usig];
616
617 /*
618 * Set up the stack frame
619 */
620 if (ka->sa.sa_flags & SA_SIGINFO)
621 ret = setup_rt_frame(usig, ka, info, oldset, regs);
622 else
623 ret = setup_frame(usig, ka, oldset, regs);
624
625 /*
626 * Check that the resulting registers are actually sane.
627 */
628 ret |= !valid_user_regs(regs);
629
630 if (ret != 0) {
631 force_sigsegv(sig, tsk);
632 return ret;
633 }
634
635 /*
636 * Block the signal if we were successful.
637 */
638 block_sigmask(ka, sig);
639
640 return 0;
641 }
642
643 /*
644 * Note that 'init' is a special process: it doesn't get signals it doesn't
645 * want to handle. Thus you cannot kill init even with a SIGKILL even by
646 * mistake.
647 *
648 * Note that we go through the signals twice: once to check the signals that
649 * the kernel can handle, and then we build all the user-level signal handling
650 * stack-frames in one go after that.
651 */
652 static void do_signal(struct pt_regs *regs, int syscall)
653 {
654 unsigned int retval = 0, continue_addr = 0, restart_addr = 0;
655 struct k_sigaction ka;
656 siginfo_t info;
657 int signr;
658
659 /*
660 * We want the common case to go fast, which
661 * is why we may in certain cases get here from
662 * kernel mode. Just return without doing anything
663 * if so.
664 */
665 if (!user_mode(regs))
666 return;
667
668 /*
669 * If we were from a system call, check for system call restarting...
670 */
671 if (syscall) {
672 continue_addr = regs->ARM_pc;
673 restart_addr = continue_addr - (thumb_mode(regs) ? 2 : 4);
674 retval = regs->ARM_r0;
675
676 /*
677 * Prepare for system call restart. We do this here so that a
678 * debugger will see the already changed PSW.
679 */
680 switch (retval) {
681 case -ERESTARTNOHAND:
682 case -ERESTARTSYS:
683 case -ERESTARTNOINTR:
684 regs->ARM_r0 = regs->ARM_ORIG_r0;
685 regs->ARM_pc = restart_addr;
686 break;
687 case -ERESTART_RESTARTBLOCK:
688 regs->ARM_r0 = -EINTR;
689 break;
690 }
691 }
692
693 if (try_to_freeze())
694 goto no_signal;
695
696 /*
697 * Get the signal to deliver. When running under ptrace, at this
698 * point the debugger may change all our registers ...
699 */
700 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
701 if (signr > 0) {
702 sigset_t *oldset;
703
704 /*
705 * Depending on the signal settings we may need to revert the
706 * decision to restart the system call. But skip this if a
707 * debugger has chosen to restart at a different PC.
708 */
709 if (regs->ARM_pc == restart_addr) {
710 if (retval == -ERESTARTNOHAND
711 || (retval == -ERESTARTSYS
712 && !(ka.sa.sa_flags & SA_RESTART))) {
713 regs->ARM_r0 = -EINTR;
714 regs->ARM_pc = continue_addr;
715 }
716 }
717
718 if (test_thread_flag(TIF_RESTORE_SIGMASK))
719 oldset = &current->saved_sigmask;
720 else
721 oldset = &current->blocked;
722 if (handle_signal(signr, &ka, &info, oldset, regs) == 0) {
723 /*
724 * A signal was successfully delivered; the saved
725 * sigmask will have been stored in the signal frame,
726 * and will be restored by sigreturn, so we can simply
727 * clear the TIF_RESTORE_SIGMASK flag.
728 */
729 if (test_thread_flag(TIF_RESTORE_SIGMASK))
730 clear_thread_flag(TIF_RESTORE_SIGMASK);
731 }
732 return;
733 }
734
735 no_signal:
736 if (syscall) {
737 /*
738 * Handle restarting a different system call. As above,
739 * if a debugger has chosen to restart at a different PC,
740 * ignore the restart.
741 */
742 if (retval == -ERESTART_RESTARTBLOCK
743 && regs->ARM_pc == continue_addr) {
744 if (thumb_mode(regs)) {
745 regs->ARM_r7 = __NR_restart_syscall - __NR_SYSCALL_BASE;
746 regs->ARM_pc -= 2;
747 } else {
748 #if defined(CONFIG_AEABI) && !defined(CONFIG_OABI_COMPAT)
749 regs->ARM_r7 = __NR_restart_syscall;
750 regs->ARM_pc -= 4;
751 #else
752 u32 __user *usp;
753
754 regs->ARM_sp -= 4;
755 usp = (u32 __user *)regs->ARM_sp;
756
757 if (put_user(regs->ARM_pc, usp) == 0) {
758 regs->ARM_pc = KERN_RESTART_CODE;
759 } else {
760 regs->ARM_sp += 4;
761 force_sigsegv(0, current);
762 }
763 #endif
764 }
765 }
766
767 /* If there's no signal to deliver, we just put the saved sigmask
768 * back.
769 */
770 if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
771 clear_thread_flag(TIF_RESTORE_SIGMASK);
772 sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
773 }
774 }
775 }
776
777 asmlinkage void
778 do_notify_resume(struct pt_regs *regs, unsigned int thread_flags, int syscall)
779 {
780 if (thread_flags & _TIF_SIGPENDING)
781 do_signal(regs, syscall);
782
783 if (thread_flags & _TIF_NOTIFY_RESUME) {
784 clear_thread_flag(TIF_NOTIFY_RESUME);
785 tracehook_notify_resume(regs);
786 if (current->replacement_session_keyring)
787 key_replace_session_keyring();
788 }
789 }
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