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x86: Fix compilation bug in kprobes' twobyte_is_boostable
[linux-btrfs-devel.git] / arch / arm / kernel / signal.c
blob0340224cf73c5c9db2d16185bd698a6ba6518fb8
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 mask &= _BLOCKABLE;
70 spin_lock_irq(&current->sighand->siglock);
71 current->saved_sigmask = current->blocked;
72 siginitset(&current->blocked, mask);
73 recalc_sigpending();
74 spin_unlock_irq(&current->sighand->siglock);
75
76 current->state = TASK_INTERRUPTIBLE;
77 schedule();
78 set_restore_sigmask();
79 return -ERESTARTNOHAND;
80 }
81
82 asmlinkage int
83 sys_sigaction(int sig, const struct old_sigaction __user *act,
84 struct old_sigaction __user *oact)
85 {
86 struct k_sigaction new_ka, old_ka;
87 int ret;
88
89 if (act) {
90 old_sigset_t mask;
91 if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
92 __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
93 __get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
94 return -EFAULT;
95 __get_user(new_ka.sa.sa_flags, &act->sa_flags);
96 __get_user(mask, &act->sa_mask);
97 siginitset(&new_ka.sa.sa_mask, mask);
98 }
99
100 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
101
102 if (!ret && oact) {
103 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
104 __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
105 __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
106 return -EFAULT;
107 __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
108 __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
109 }
110
111 return ret;
112 }
113
114 #ifdef CONFIG_CRUNCH
115 static int preserve_crunch_context(struct crunch_sigframe __user *frame)
116 {
117 char kbuf[sizeof(*frame) + 8];
118 struct crunch_sigframe *kframe;
119
120 /* the crunch context must be 64 bit aligned */
121 kframe = (struct crunch_sigframe *)((unsigned long)(kbuf + 8) & ~7);
122 kframe->magic = CRUNCH_MAGIC;
123 kframe->size = CRUNCH_STORAGE_SIZE;
124 crunch_task_copy(current_thread_info(), &kframe->storage);
125 return __copy_to_user(frame, kframe, sizeof(*frame));
126 }
127
128 static int restore_crunch_context(struct crunch_sigframe __user *frame)
129 {
130 char kbuf[sizeof(*frame) + 8];
131 struct crunch_sigframe *kframe;
132
133 /* the crunch context must be 64 bit aligned */
134 kframe = (struct crunch_sigframe *)((unsigned long)(kbuf + 8) & ~7);
135 if (__copy_from_user(kframe, frame, sizeof(*frame)))
136 return -1;
137 if (kframe->magic != CRUNCH_MAGIC ||
138 kframe->size != CRUNCH_STORAGE_SIZE)
139 return -1;
140 crunch_task_restore(current_thread_info(), &kframe->storage);
141 return 0;
142 }
143 #endif
144
145 #ifdef CONFIG_IWMMXT
146
147 static int preserve_iwmmxt_context(struct iwmmxt_sigframe *frame)
148 {
149 char kbuf[sizeof(*frame) + 8];
150 struct iwmmxt_sigframe *kframe;
151
152 /* the iWMMXt context must be 64 bit aligned */
153 kframe = (struct iwmmxt_sigframe *)((unsigned long)(kbuf + 8) & ~7);
154 kframe->magic = IWMMXT_MAGIC;
155 kframe->size = IWMMXT_STORAGE_SIZE;
156 iwmmxt_task_copy(current_thread_info(), &kframe->storage);
157 return __copy_to_user(frame, kframe, sizeof(*frame));
158 }
159
160 static int restore_iwmmxt_context(struct iwmmxt_sigframe *frame)
161 {
162 char kbuf[sizeof(*frame) + 8];
163 struct iwmmxt_sigframe *kframe;
164
165 /* the iWMMXt context must be 64 bit aligned */
166 kframe = (struct iwmmxt_sigframe *)((unsigned long)(kbuf + 8) & ~7);
167 if (__copy_from_user(kframe, frame, sizeof(*frame)))
168 return -1;
169 if (kframe->magic != IWMMXT_MAGIC ||
170 kframe->size != IWMMXT_STORAGE_SIZE)
171 return -1;
172 iwmmxt_task_restore(current_thread_info(), &kframe->storage);
173 return 0;
174 }
175
176 #endif
177
178 #ifdef CONFIG_VFP
179
180 static int preserve_vfp_context(struct vfp_sigframe __user *frame)
181 {
182 struct thread_info *thread = current_thread_info();
183 struct vfp_hard_struct *h = &thread->vfpstate.hard;
184 const unsigned long magic = VFP_MAGIC;
185 const unsigned long size = VFP_STORAGE_SIZE;
186 int err = 0;
187
188 vfp_sync_hwstate(thread);
189 __put_user_error(magic, &frame->magic, err);
190 __put_user_error(size, &frame->size, err);
191
192 /*
193 * Copy the floating point registers. There can be unused
194 * registers see asm/hwcap.h for details.
195 */
196 err |= __copy_to_user(&frame->ufp.fpregs, &h->fpregs,
197 sizeof(h->fpregs));
198 /*
199 * Copy the status and control register.
200 */
201 __put_user_error(h->fpscr, &frame->ufp.fpscr, err);
202
203 /*
204 * Copy the exception registers.
205 */
206 __put_user_error(h->fpexc, &frame->ufp_exc.fpexc, err);
207 __put_user_error(h->fpinst, &frame->ufp_exc.fpinst, err);
208 __put_user_error(h->fpinst2, &frame->ufp_exc.fpinst2, err);
209
210 return err ? -EFAULT : 0;
211 }
212
213 static int restore_vfp_context(struct vfp_sigframe __user *frame)
214 {
215 struct thread_info *thread = current_thread_info();
216 struct vfp_hard_struct *h = &thread->vfpstate.hard;
217 unsigned long magic;
218 unsigned long size;
219 unsigned long fpexc;
220 int err = 0;
221
222 __get_user_error(magic, &frame->magic, err);
223 __get_user_error(size, &frame->size, err);
224
225 if (err)
226 return -EFAULT;
227 if (magic != VFP_MAGIC || size != VFP_STORAGE_SIZE)
228 return -EINVAL;
229
230 /*
231 * Copy the floating point registers. There can be unused
232 * registers see asm/hwcap.h for details.
233 */
234 err |= __copy_from_user(&h->fpregs, &frame->ufp.fpregs,
235 sizeof(h->fpregs));
236 /*
237 * Copy the status and control register.
238 */
239 __get_user_error(h->fpscr, &frame->ufp.fpscr, err);
240
241 /*
242 * Sanitise and restore the exception registers.
243 */
244 __get_user_error(fpexc, &frame->ufp_exc.fpexc, err);
245 /* Ensure the VFP is enabled. */
246 fpexc |= FPEXC_EN;
247 /* Ensure FPINST2 is invalid and the exception flag is cleared. */
248 fpexc &= ~(FPEXC_EX | FPEXC_FP2V);
249 h->fpexc = fpexc;
250
251 __get_user_error(h->fpinst, &frame->ufp_exc.fpinst, err);
252 __get_user_error(h->fpinst2, &frame->ufp_exc.fpinst2, err);
253
254 if (!err)
255 vfp_flush_hwstate(thread);
256
257 return err ? -EFAULT : 0;
258 }
259
260 #endif
261
262 /*
263 * Do a signal return; undo the signal stack. These are aligned to 64-bit.
264 */
265 struct sigframe {
266 struct ucontext uc;
267 unsigned long retcode[2];
268 };
269
270 struct rt_sigframe {
271 struct siginfo info;
272 struct sigframe sig;
273 };
274
275 static int restore_sigframe(struct pt_regs *regs, struct sigframe __user *sf)
276 {
277 struct aux_sigframe __user *aux;
278 sigset_t set;
279 int err;
280
281 err = __copy_from_user(&set, &sf->uc.uc_sigmask, sizeof(set));
282 if (err == 0) {
283 sigdelsetmask(&set, ~_BLOCKABLE);
284 spin_lock_irq(&current->sighand->siglock);
285 current->blocked = set;
286 recalc_sigpending();
287 spin_unlock_irq(&current->sighand->siglock);
288 }
289
290 __get_user_error(regs->ARM_r0, &sf->uc.uc_mcontext.arm_r0, err);
291 __get_user_error(regs->ARM_r1, &sf->uc.uc_mcontext.arm_r1, err);
292 __get_user_error(regs->ARM_r2, &sf->uc.uc_mcontext.arm_r2, err);
293 __get_user_error(regs->ARM_r3, &sf->uc.uc_mcontext.arm_r3, err);
294 __get_user_error(regs->ARM_r4, &sf->uc.uc_mcontext.arm_r4, err);
295 __get_user_error(regs->ARM_r5, &sf->uc.uc_mcontext.arm_r5, err);
296 __get_user_error(regs->ARM_r6, &sf->uc.uc_mcontext.arm_r6, err);
297 __get_user_error(regs->ARM_r7, &sf->uc.uc_mcontext.arm_r7, err);
298 __get_user_error(regs->ARM_r8, &sf->uc.uc_mcontext.arm_r8, err);
299 __get_user_error(regs->ARM_r9, &sf->uc.uc_mcontext.arm_r9, err);
300 __get_user_error(regs->ARM_r10, &sf->uc.uc_mcontext.arm_r10, err);
301 __get_user_error(regs->ARM_fp, &sf->uc.uc_mcontext.arm_fp, err);
302 __get_user_error(regs->ARM_ip, &sf->uc.uc_mcontext.arm_ip, err);
303 __get_user_error(regs->ARM_sp, &sf->uc.uc_mcontext.arm_sp, err);
304 __get_user_error(regs->ARM_lr, &sf->uc.uc_mcontext.arm_lr, err);
305 __get_user_error(regs->ARM_pc, &sf->uc.uc_mcontext.arm_pc, err);
306 __get_user_error(regs->ARM_cpsr, &sf->uc.uc_mcontext.arm_cpsr, err);
307
308 err |= !valid_user_regs(regs);
309
310 aux = (struct aux_sigframe __user *) sf->uc.uc_regspace;
311 #ifdef CONFIG_CRUNCH
312 if (err == 0)
313 err |= restore_crunch_context(&aux->crunch);
314 #endif
315 #ifdef CONFIG_IWMMXT
316 if (err == 0 && test_thread_flag(TIF_USING_IWMMXT))
317 err |= restore_iwmmxt_context(&aux->iwmmxt);
318 #endif
319 #ifdef CONFIG_VFP
320 if (err == 0)
321 err |= restore_vfp_context(&aux->vfp);
322 #endif
323
324 return err;
325 }
326
327 asmlinkage int sys_sigreturn(struct pt_regs *regs)
328 {
329 struct sigframe __user *frame;
330
331 /* Always make any pending restarted system calls return -EINTR */
332 current_thread_info()->restart_block.fn = do_no_restart_syscall;
333
334 /*
335 * Since we stacked the signal on a 64-bit boundary,
336 * then 'sp' should be word aligned here. If it's
337 * not, then the user is trying to mess with us.
338 */
339 if (regs->ARM_sp & 7)
340 goto badframe;
341
342 frame = (struct sigframe __user *)regs->ARM_sp;
343
344 if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
345 goto badframe;
346
347 if (restore_sigframe(regs, frame))
348 goto badframe;
349
350 return regs->ARM_r0;
351
352 badframe:
353 force_sig(SIGSEGV, current);
354 return 0;
355 }
356
357 asmlinkage int sys_rt_sigreturn(struct pt_regs *regs)
358 {
359 struct rt_sigframe __user *frame;
360
361 /* Always make any pending restarted system calls return -EINTR */
362 current_thread_info()->restart_block.fn = do_no_restart_syscall;
363
364 /*
365 * Since we stacked the signal on a 64-bit boundary,
366 * then 'sp' should be word aligned here. If it's
367 * not, then the user is trying to mess with us.
368 */
369 if (regs->ARM_sp & 7)
370 goto badframe;
371
372 frame = (struct rt_sigframe __user *)regs->ARM_sp;
373
374 if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
375 goto badframe;
376
377 if (restore_sigframe(regs, &frame->sig))
378 goto badframe;
379
380 if (do_sigaltstack(&frame->sig.uc.uc_stack, NULL, regs->ARM_sp) == -EFAULT)
381 goto badframe;
382
383 return regs->ARM_r0;
384
385 badframe:
386 force_sig(SIGSEGV, current);
387 return 0;
388 }
389
390 static int
391 setup_sigframe(struct sigframe __user *sf, struct pt_regs *regs, sigset_t *set)
392 {
393 struct aux_sigframe __user *aux;
394 int err = 0;
395
396 __put_user_error(regs->ARM_r0, &sf->uc.uc_mcontext.arm_r0, err);
397 __put_user_error(regs->ARM_r1, &sf->uc.uc_mcontext.arm_r1, err);
398 __put_user_error(regs->ARM_r2, &sf->uc.uc_mcontext.arm_r2, err);
399 __put_user_error(regs->ARM_r3, &sf->uc.uc_mcontext.arm_r3, err);
400 __put_user_error(regs->ARM_r4, &sf->uc.uc_mcontext.arm_r4, err);
401 __put_user_error(regs->ARM_r5, &sf->uc.uc_mcontext.arm_r5, err);
402 __put_user_error(regs->ARM_r6, &sf->uc.uc_mcontext.arm_r6, err);
403 __put_user_error(regs->ARM_r7, &sf->uc.uc_mcontext.arm_r7, err);
404 __put_user_error(regs->ARM_r8, &sf->uc.uc_mcontext.arm_r8, err);
405 __put_user_error(regs->ARM_r9, &sf->uc.uc_mcontext.arm_r9, err);
406 __put_user_error(regs->ARM_r10, &sf->uc.uc_mcontext.arm_r10, err);
407 __put_user_error(regs->ARM_fp, &sf->uc.uc_mcontext.arm_fp, err);
408 __put_user_error(regs->ARM_ip, &sf->uc.uc_mcontext.arm_ip, err);
409 __put_user_error(regs->ARM_sp, &sf->uc.uc_mcontext.arm_sp, err);
410 __put_user_error(regs->ARM_lr, &sf->uc.uc_mcontext.arm_lr, err);
411 __put_user_error(regs->ARM_pc, &sf->uc.uc_mcontext.arm_pc, err);
412 __put_user_error(regs->ARM_cpsr, &sf->uc.uc_mcontext.arm_cpsr, err);
413
414 __put_user_error(current->thread.trap_no, &sf->uc.uc_mcontext.trap_no, err);
415 __put_user_error(current->thread.error_code, &sf->uc.uc_mcontext.error_code, err);
416 __put_user_error(current->thread.address, &sf->uc.uc_mcontext.fault_address, err);
417 __put_user_error(set->sig[0], &sf->uc.uc_mcontext.oldmask, err);
418
419 err |= __copy_to_user(&sf->uc.uc_sigmask, set, sizeof(*set));
420
421 aux = (struct aux_sigframe __user *) sf->uc.uc_regspace;
422 #ifdef CONFIG_CRUNCH
423 if (err == 0)
424 err |= preserve_crunch_context(&aux->crunch);
425 #endif
426 #ifdef CONFIG_IWMMXT
427 if (err == 0 && test_thread_flag(TIF_USING_IWMMXT))
428 err |= preserve_iwmmxt_context(&aux->iwmmxt);
429 #endif
430 #ifdef CONFIG_VFP
431 if (err == 0)
432 err |= preserve_vfp_context(&aux->vfp);
433 #endif
434 __put_user_error(0, &aux->end_magic, err);
435
436 return err;
437 }
438
439 static inline void __user *
440 get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, int framesize)
441 {
442 unsigned long sp = regs->ARM_sp;
443 void __user *frame;
444
445 /*
446 * This is the X/Open sanctioned signal stack switching.
447 */
448 if ((ka->sa.sa_flags & SA_ONSTACK) && !sas_ss_flags(sp))
449 sp = current->sas_ss_sp + current->sas_ss_size;
450
451 /*
452 * ATPCS B01 mandates 8-byte alignment
453 */
454 frame = (void __user *)((sp - framesize) & ~7);
455
456 /*
457 * Check that we can actually write to the signal frame.
458 */
459 if (!access_ok(VERIFY_WRITE, frame, framesize))
460 frame = NULL;
461
462 return frame;
463 }
464
465 static int
466 setup_return(struct pt_regs *regs, struct k_sigaction *ka,
467 unsigned long __user *rc, void __user *frame, int usig)
468 {
469 unsigned long handler = (unsigned long)ka->sa.sa_handler;
470 unsigned long retcode;
471 int thumb = 0;
472 unsigned long cpsr = regs->ARM_cpsr & ~(PSR_f | PSR_E_BIT);
473
474 cpsr |= PSR_ENDSTATE;
475
476 /*
477 * Maybe we need to deliver a 32-bit signal to a 26-bit task.
478 */
479 if (ka->sa.sa_flags & SA_THIRTYTWO)
480 cpsr = (cpsr & ~MODE_MASK) | USR_MODE;
481
482 #ifdef CONFIG_ARM_THUMB
483 if (elf_hwcap & HWCAP_THUMB) {
484 /*
485 * The LSB of the handler determines if we're going to
486 * be using THUMB or ARM mode for this signal handler.
487 */
488 thumb = handler & 1;
489
490 if (thumb) {
491 cpsr |= PSR_T_BIT;
492 #if __LINUX_ARM_ARCH__ >= 7
493 /* clear the If-Then Thumb-2 execution state */
494 cpsr &= ~PSR_IT_MASK;
495 #endif
496 } else
497 cpsr &= ~PSR_T_BIT;
498 }
499 #endif
500
501 if (ka->sa.sa_flags & SA_RESTORER) {
502 retcode = (unsigned long)ka->sa.sa_restorer;
503 } else {
504 unsigned int idx = thumb << 1;
505
506 if (ka->sa.sa_flags & SA_SIGINFO)
507 idx += 3;
508
509 if (__put_user(sigreturn_codes[idx], rc) ||
510 __put_user(sigreturn_codes[idx+1], rc+1))
511 return 1;
512
513 if (cpsr & MODE32_BIT) {
514 /*
515 * 32-bit code can use the new high-page
516 * signal return code support.
517 */
518 retcode = KERN_SIGRETURN_CODE + (idx << 2) + thumb;
519 } else {
520 /*
521 * Ensure that the instruction cache sees
522 * the return code written onto the stack.
523 */
524 flush_icache_range((unsigned long)rc,
525 (unsigned long)(rc + 2));
526
527 retcode = ((unsigned long)rc) + thumb;
528 }
529 }
530
531 regs->ARM_r0 = usig;
532 regs->ARM_sp = (unsigned long)frame;
533 regs->ARM_lr = retcode;
534 regs->ARM_pc = handler;
535 regs->ARM_cpsr = cpsr;
536
537 return 0;
538 }
539
540 static int
541 setup_frame(int usig, struct k_sigaction *ka, sigset_t *set, struct pt_regs *regs)
542 {
543 struct sigframe __user *frame = get_sigframe(ka, regs, sizeof(*frame));
544 int err = 0;
545
546 if (!frame)
547 return 1;
548
549 /*
550 * Set uc.uc_flags to a value which sc.trap_no would never have.
551 */
552 __put_user_error(0x5ac3c35a, &frame->uc.uc_flags, err);
553
554 err |= setup_sigframe(frame, regs, set);
555 if (err == 0)
556 err = setup_return(regs, ka, frame->retcode, frame, usig);
557
558 return err;
559 }
560
561 static int
562 setup_rt_frame(int usig, struct k_sigaction *ka, siginfo_t *info,
563 sigset_t *set, struct pt_regs *regs)
564 {
565 struct rt_sigframe __user *frame = get_sigframe(ka, regs, sizeof(*frame));
566 stack_t stack;
567 int err = 0;
568
569 if (!frame)
570 return 1;
571
572 err |= copy_siginfo_to_user(&frame->info, info);
573
574 __put_user_error(0, &frame->sig.uc.uc_flags, err);
575 __put_user_error(NULL, &frame->sig.uc.uc_link, err);
576
577 memset(&stack, 0, sizeof(stack));
578 stack.ss_sp = (void __user *)current->sas_ss_sp;
579 stack.ss_flags = sas_ss_flags(regs->ARM_sp);
580 stack.ss_size = current->sas_ss_size;
581 err |= __copy_to_user(&frame->sig.uc.uc_stack, &stack, sizeof(stack));
582
583 err |= setup_sigframe(&frame->sig, regs, set);
584 if (err == 0)
585 err = setup_return(regs, ka, frame->sig.retcode, frame, usig);
586
587 if (err == 0) {
588 /*
589 * For realtime signals we must also set the second and third
590 * arguments for the signal handler.
591 * -- Peter Maydell <pmaydell@chiark.greenend.org.uk> 2000-12-06
592 */
593 regs->ARM_r1 = (unsigned long)&frame->info;
594 regs->ARM_r2 = (unsigned long)&frame->sig.uc;
595 }
596
597 return err;
598 }
599
600 /*
601 * OK, we're invoking a handler
602 */
603 static int
604 handle_signal(unsigned long sig, struct k_sigaction *ka,
605 siginfo_t *info, sigset_t *oldset,
606 struct pt_regs * regs)
607 {
608 struct thread_info *thread = current_thread_info();
609 struct task_struct *tsk = current;
610 int usig = sig;
611 int ret;
612
613 /*
614 * translate the signal
615 */
616 if (usig < 32 && thread->exec_domain && thread->exec_domain->signal_invmap)
617 usig = thread->exec_domain->signal_invmap[usig];
618
619 /*
620 * Set up the stack frame
621 */
622 if (ka->sa.sa_flags & SA_SIGINFO)
623 ret = setup_rt_frame(usig, ka, info, oldset, regs);
624 else
625 ret = setup_frame(usig, ka, oldset, regs);
626
627 /*
628 * Check that the resulting registers are actually sane.
629 */
630 ret |= !valid_user_regs(regs);
631
632 if (ret != 0) {
633 force_sigsegv(sig, tsk);
634 return ret;
635 }
636
637 /*
638 * Block the signal if we were successful.
639 */
640 spin_lock_irq(&tsk->sighand->siglock);
641 sigorsets(&tsk->blocked, &tsk->blocked,
642 &ka->sa.sa_mask);
643 if (!(ka->sa.sa_flags & SA_NODEFER))
644 sigaddset(&tsk->blocked, sig);
645 recalc_sigpending();
646 spin_unlock_irq(&tsk->sighand->siglock);
647
648 return 0;
649 }
650
651 /*
652 * Note that 'init' is a special process: it doesn't get signals it doesn't
653 * want to handle. Thus you cannot kill init even with a SIGKILL even by
654 * mistake.
655 *
656 * Note that we go through the signals twice: once to check the signals that
657 * the kernel can handle, and then we build all the user-level signal handling
658 * stack-frames in one go after that.
659 */
660 static void do_signal(struct pt_regs *regs, int syscall)
661 {
662 unsigned int retval = 0, continue_addr = 0, restart_addr = 0;
663 struct k_sigaction ka;
664 siginfo_t info;
665 int signr;
666
667 /*
668 * We want the common case to go fast, which
669 * is why we may in certain cases get here from
670 * kernel mode. Just return without doing anything
671 * if so.
672 */
673 if (!user_mode(regs))
674 return;
675
676 /*
677 * If we were from a system call, check for system call restarting...
678 */
679 if (syscall) {
680 continue_addr = regs->ARM_pc;
681 restart_addr = continue_addr - (thumb_mode(regs) ? 2 : 4);
682 retval = regs->ARM_r0;
683
684 /*
685 * Prepare for system call restart. We do this here so that a
686 * debugger will see the already changed PSW.
687 */
688 switch (retval) {
689 case -ERESTARTNOHAND:
690 case -ERESTARTSYS:
691 case -ERESTARTNOINTR:
692 regs->ARM_r0 = regs->ARM_ORIG_r0;
693 regs->ARM_pc = restart_addr;
694 break;
695 case -ERESTART_RESTARTBLOCK:
696 regs->ARM_r0 = -EINTR;
697 break;
698 }
699 }
700
701 if (try_to_freeze())
702 goto no_signal;
703
704 /*
705 * Get the signal to deliver. When running under ptrace, at this
706 * point the debugger may change all our registers ...
707 */
708 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
709 if (signr > 0) {
710 sigset_t *oldset;
711
712 /*
713 * Depending on the signal settings we may need to revert the
714 * decision to restart the system call. But skip this if a
715 * debugger has chosen to restart at a different PC.
716 */
717 if (regs->ARM_pc == restart_addr) {
718 if (retval == -ERESTARTNOHAND
719 || (retval == -ERESTARTSYS
720 && !(ka.sa.sa_flags & SA_RESTART))) {
721 regs->ARM_r0 = -EINTR;
722 regs->ARM_pc = continue_addr;
723 }
724 }
725
726 if (test_thread_flag(TIF_RESTORE_SIGMASK))
727 oldset = &current->saved_sigmask;
728 else
729 oldset = &current->blocked;
730 if (handle_signal(signr, &ka, &info, oldset, regs) == 0) {
731 /*
732 * A signal was successfully delivered; the saved
733 * sigmask will have been stored in the signal frame,
734 * and will be restored by sigreturn, so we can simply
735 * clear the TIF_RESTORE_SIGMASK flag.
736 */
737 if (test_thread_flag(TIF_RESTORE_SIGMASK))
738 clear_thread_flag(TIF_RESTORE_SIGMASK);
739 }
740 return;
741 }
742
743 no_signal:
744 if (syscall) {
745 /*
746 * Handle restarting a different system call. As above,
747 * if a debugger has chosen to restart at a different PC,
748 * ignore the restart.
749 */
750 if (retval == -ERESTART_RESTARTBLOCK
751 && regs->ARM_pc == continue_addr) {
752 if (thumb_mode(regs)) {
753 regs->ARM_r7 = __NR_restart_syscall - __NR_SYSCALL_BASE;
754 regs->ARM_pc -= 2;
755 } else {
756 #if defined(CONFIG_AEABI) && !defined(CONFIG_OABI_COMPAT)
757 regs->ARM_r7 = __NR_restart_syscall;
758 regs->ARM_pc -= 4;
759 #else
760 u32 __user *usp;
761
762 regs->ARM_sp -= 4;
763 usp = (u32 __user *)regs->ARM_sp;
764
765 if (put_user(regs->ARM_pc, usp) == 0) {
766 regs->ARM_pc = KERN_RESTART_CODE;
767 } else {
768 regs->ARM_sp += 4;
769 force_sigsegv(0, current);
770 }
771 #endif
772 }
773 }
774
775 /* If there's no signal to deliver, we just put the saved sigmask
776 * back.
777 */
778 if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
779 clear_thread_flag(TIF_RESTORE_SIGMASK);
780 sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
781 }
782 }
783 }
784
785 asmlinkage void
786 do_notify_resume(struct pt_regs *regs, unsigned int thread_flags, int syscall)
787 {
788 if (thread_flags & _TIF_SIGPENDING)
789 do_signal(regs, syscall);
790
791 if (thread_flags & _TIF_NOTIFY_RESUME) {
792 clear_thread_flag(TIF_NOTIFY_RESUME);
793 tracehook_notify_resume(regs);
794 if (current->replacement_session_keyring)
795 key_replace_session_keyring();
796 }
797 }
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