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1da177e4 LT |
1 | /* |
2 | * linux/arch/arm/kernel/signal.c | |
3 | * | |
4 | * Copyright (C) 1995-2002 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/config.h> | |
11 | #include <linux/errno.h> | |
12 | #include <linux/signal.h> | |
13 | #include <linux/ptrace.h> | |
14 | #include <linux/personality.h> | |
15 | ||
16 | #include <asm/cacheflush.h> | |
17 | #include <asm/ucontext.h> | |
18 | #include <asm/uaccess.h> | |
19 | #include <asm/unistd.h> | |
20 | ||
21 | #include "ptrace.h" | |
22 | ||
23 | #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) | |
24 | ||
25 | /* | |
26 | * For ARM syscalls, we encode the syscall number into the instruction. | |
27 | */ | |
28 | #define SWI_SYS_SIGRETURN (0xef000000|(__NR_sigreturn)) | |
29 | #define SWI_SYS_RT_SIGRETURN (0xef000000|(__NR_rt_sigreturn)) | |
30 | ||
31 | /* | |
32 | * For Thumb syscalls, we pass the syscall number via r7. We therefore | |
33 | * need two 16-bit instructions. | |
34 | */ | |
35 | #define SWI_THUMB_SIGRETURN (0xdf00 << 16 | 0x2700 | (__NR_sigreturn - __NR_SYSCALL_BASE)) | |
36 | #define SWI_THUMB_RT_SIGRETURN (0xdf00 << 16 | 0x2700 | (__NR_rt_sigreturn - __NR_SYSCALL_BASE)) | |
37 | ||
38 | static const unsigned long retcodes[4] = { | |
39 | SWI_SYS_SIGRETURN, SWI_THUMB_SIGRETURN, | |
40 | SWI_SYS_RT_SIGRETURN, SWI_THUMB_RT_SIGRETURN | |
41 | }; | |
42 | ||
43 | static int do_signal(sigset_t *oldset, struct pt_regs * regs, int syscall); | |
44 | ||
45 | /* | |
46 | * atomically swap in the new signal mask, and wait for a signal. | |
47 | */ | |
48 | asmlinkage int sys_sigsuspend(int restart, unsigned long oldmask, old_sigset_t mask, struct pt_regs *regs) | |
49 | { | |
50 | sigset_t saveset; | |
51 | ||
52 | mask &= _BLOCKABLE; | |
53 | spin_lock_irq(¤t->sighand->siglock); | |
54 | saveset = current->blocked; | |
55 | siginitset(¤t->blocked, mask); | |
56 | recalc_sigpending(); | |
57 | spin_unlock_irq(¤t->sighand->siglock); | |
58 | regs->ARM_r0 = -EINTR; | |
59 | ||
60 | while (1) { | |
61 | current->state = TASK_INTERRUPTIBLE; | |
62 | schedule(); | |
63 | if (do_signal(&saveset, regs, 0)) | |
64 | return regs->ARM_r0; | |
65 | } | |
66 | } | |
67 | ||
68 | asmlinkage int | |
69 | sys_rt_sigsuspend(sigset_t __user *unewset, size_t sigsetsize, struct pt_regs *regs) | |
70 | { | |
71 | sigset_t saveset, newset; | |
72 | ||
73 | /* XXX: Don't preclude handling different sized sigset_t's. */ | |
74 | if (sigsetsize != sizeof(sigset_t)) | |
75 | return -EINVAL; | |
76 | ||
77 | if (copy_from_user(&newset, unewset, sizeof(newset))) | |
78 | return -EFAULT; | |
79 | sigdelsetmask(&newset, ~_BLOCKABLE); | |
80 | ||
81 | spin_lock_irq(¤t->sighand->siglock); | |
82 | saveset = current->blocked; | |
83 | current->blocked = newset; | |
84 | recalc_sigpending(); | |
85 | spin_unlock_irq(¤t->sighand->siglock); | |
86 | regs->ARM_r0 = -EINTR; | |
87 | ||
88 | while (1) { | |
89 | current->state = TASK_INTERRUPTIBLE; | |
90 | schedule(); | |
91 | if (do_signal(&saveset, regs, 0)) | |
92 | return regs->ARM_r0; | |
93 | } | |
94 | } | |
95 | ||
96 | asmlinkage int | |
97 | sys_sigaction(int sig, const struct old_sigaction __user *act, | |
98 | struct old_sigaction __user *oact) | |
99 | { | |
100 | struct k_sigaction new_ka, old_ka; | |
101 | int ret; | |
102 | ||
103 | if (act) { | |
104 | old_sigset_t mask; | |
105 | if (!access_ok(VERIFY_READ, act, sizeof(*act)) || | |
106 | __get_user(new_ka.sa.sa_handler, &act->sa_handler) || | |
107 | __get_user(new_ka.sa.sa_restorer, &act->sa_restorer)) | |
108 | return -EFAULT; | |
109 | __get_user(new_ka.sa.sa_flags, &act->sa_flags); | |
110 | __get_user(mask, &act->sa_mask); | |
111 | siginitset(&new_ka.sa.sa_mask, mask); | |
112 | } | |
113 | ||
114 | ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); | |
115 | ||
116 | if (!ret && oact) { | |
117 | if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) || | |
118 | __put_user(old_ka.sa.sa_handler, &oact->sa_handler) || | |
119 | __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer)) | |
120 | return -EFAULT; | |
121 | __put_user(old_ka.sa.sa_flags, &oact->sa_flags); | |
122 | __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask); | |
123 | } | |
124 | ||
125 | return ret; | |
126 | } | |
127 | ||
128 | #ifdef CONFIG_IWMMXT | |
129 | ||
130 | /* iwmmxt_area is 0x98 bytes long, preceeded by 8 bytes of signature */ | |
131 | #define IWMMXT_STORAGE_SIZE (0x98 + 8) | |
132 | #define IWMMXT_MAGIC0 0x12ef842a | |
133 | #define IWMMXT_MAGIC1 0x1c07ca71 | |
134 | ||
135 | struct iwmmxt_sigframe { | |
136 | unsigned long magic0; | |
137 | unsigned long magic1; | |
138 | unsigned long storage[0x98/4]; | |
139 | }; | |
140 | ||
141 | static int page_present(struct mm_struct *mm, void __user *uptr, int wr) | |
142 | { | |
143 | unsigned long addr = (unsigned long)uptr; | |
144 | pgd_t *pgd = pgd_offset(mm, addr); | |
145 | if (pgd_present(*pgd)) { | |
146 | pmd_t *pmd = pmd_offset(pgd, addr); | |
147 | if (pmd_present(*pmd)) { | |
148 | pte_t *pte = pte_offset_map(pmd, addr); | |
149 | return (pte_present(*pte) && (!wr || pte_write(*pte))); | |
150 | } | |
151 | } | |
152 | return 0; | |
153 | } | |
154 | ||
155 | static int copy_locked(void __user *uptr, void *kptr, size_t size, int write, | |
156 | void (*copyfn)(void *, void __user *)) | |
157 | { | |
158 | unsigned char v, __user *userptr = uptr; | |
159 | int err = 0; | |
160 | ||
161 | do { | |
162 | struct mm_struct *mm; | |
163 | ||
164 | if (write) { | |
165 | __put_user_error(0, userptr, err); | |
166 | __put_user_error(0, userptr + size - 1, err); | |
167 | } else { | |
168 | __get_user_error(v, userptr, err); | |
169 | __get_user_error(v, userptr + size - 1, err); | |
170 | } | |
171 | ||
172 | if (err) | |
173 | break; | |
174 | ||
175 | mm = current->mm; | |
176 | spin_lock(&mm->page_table_lock); | |
177 | if (page_present(mm, userptr, write) && | |
178 | page_present(mm, userptr + size - 1, write)) { | |
179 | copyfn(kptr, uptr); | |
180 | } else | |
181 | err = 1; | |
182 | spin_unlock(&mm->page_table_lock); | |
183 | } while (err); | |
184 | ||
185 | return err; | |
186 | } | |
187 | ||
188 | static int preserve_iwmmxt_context(struct iwmmxt_sigframe *frame) | |
189 | { | |
190 | int err = 0; | |
191 | ||
192 | /* the iWMMXt context must be 64 bit aligned */ | |
193 | WARN_ON((unsigned long)frame & 7); | |
194 | ||
195 | __put_user_error(IWMMXT_MAGIC0, &frame->magic0, err); | |
196 | __put_user_error(IWMMXT_MAGIC1, &frame->magic1, err); | |
197 | ||
198 | /* | |
199 | * iwmmxt_task_copy() doesn't check user permissions. | |
200 | * Let's do a dummy write on the upper boundary to ensure | |
201 | * access to user mem is OK all way up. | |
202 | */ | |
203 | err |= copy_locked(&frame->storage, current_thread_info(), | |
204 | sizeof(frame->storage), 1, iwmmxt_task_copy); | |
205 | return err; | |
206 | } | |
207 | ||
208 | static int restore_iwmmxt_context(struct iwmmxt_sigframe *frame) | |
209 | { | |
210 | unsigned long magic0, magic1; | |
211 | int err = 0; | |
212 | ||
213 | /* the iWMMXt context is 64 bit aligned */ | |
214 | WARN_ON((unsigned long)frame & 7); | |
215 | ||
216 | /* | |
217 | * Validate iWMMXt context signature. | |
218 | * Also, iwmmxt_task_restore() doesn't check user permissions. | |
219 | * Let's do a dummy write on the upper boundary to ensure | |
220 | * access to user mem is OK all way up. | |
221 | */ | |
222 | __get_user_error(magic0, &frame->magic0, err); | |
223 | __get_user_error(magic1, &frame->magic1, err); | |
224 | if (!err && magic0 == IWMMXT_MAGIC0 && magic1 == IWMMXT_MAGIC1) | |
225 | err = copy_locked(&frame->storage, current_thread_info(), | |
226 | sizeof(frame->storage), 0, iwmmxt_task_restore); | |
227 | return err; | |
228 | } | |
229 | ||
230 | #endif | |
231 | ||
232 | /* | |
233 | * Auxiliary signal frame. This saves stuff like FP state. | |
234 | * The layout of this structure is not part of the user ABI. | |
235 | */ | |
236 | struct aux_sigframe { | |
237 | #ifdef CONFIG_IWMMXT | |
238 | struct iwmmxt_sigframe iwmmxt; | |
239 | #endif | |
240 | #ifdef CONFIG_VFP | |
241 | union vfp_state vfp; | |
242 | #endif | |
243 | }; | |
244 | ||
245 | /* | |
246 | * Do a signal return; undo the signal stack. These are aligned to 64-bit. | |
247 | */ | |
248 | struct sigframe { | |
249 | struct sigcontext sc; | |
250 | unsigned long extramask[_NSIG_WORDS-1]; | |
251 | unsigned long retcode; | |
252 | struct aux_sigframe aux __attribute__((aligned(8))); | |
253 | }; | |
254 | ||
255 | struct rt_sigframe { | |
256 | struct siginfo __user *pinfo; | |
257 | void __user *puc; | |
258 | struct siginfo info; | |
259 | struct ucontext uc; | |
260 | unsigned long retcode; | |
261 | struct aux_sigframe aux __attribute__((aligned(8))); | |
262 | }; | |
263 | ||
264 | static int | |
265 | restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, | |
266 | struct aux_sigframe __user *aux) | |
267 | { | |
268 | int err = 0; | |
269 | ||
270 | __get_user_error(regs->ARM_r0, &sc->arm_r0, err); | |
271 | __get_user_error(regs->ARM_r1, &sc->arm_r1, err); | |
272 | __get_user_error(regs->ARM_r2, &sc->arm_r2, err); | |
273 | __get_user_error(regs->ARM_r3, &sc->arm_r3, err); | |
274 | __get_user_error(regs->ARM_r4, &sc->arm_r4, err); | |
275 | __get_user_error(regs->ARM_r5, &sc->arm_r5, err); | |
276 | __get_user_error(regs->ARM_r6, &sc->arm_r6, err); | |
277 | __get_user_error(regs->ARM_r7, &sc->arm_r7, err); | |
278 | __get_user_error(regs->ARM_r8, &sc->arm_r8, err); | |
279 | __get_user_error(regs->ARM_r9, &sc->arm_r9, err); | |
280 | __get_user_error(regs->ARM_r10, &sc->arm_r10, err); | |
281 | __get_user_error(regs->ARM_fp, &sc->arm_fp, err); | |
282 | __get_user_error(regs->ARM_ip, &sc->arm_ip, err); | |
283 | __get_user_error(regs->ARM_sp, &sc->arm_sp, err); | |
284 | __get_user_error(regs->ARM_lr, &sc->arm_lr, err); | |
285 | __get_user_error(regs->ARM_pc, &sc->arm_pc, err); | |
286 | __get_user_error(regs->ARM_cpsr, &sc->arm_cpsr, err); | |
287 | ||
288 | err |= !valid_user_regs(regs); | |
289 | ||
290 | #ifdef CONFIG_IWMMXT | |
291 | if (err == 0 && test_thread_flag(TIF_USING_IWMMXT)) | |
292 | err |= restore_iwmmxt_context(&aux->iwmmxt); | |
293 | #endif | |
294 | #ifdef CONFIG_VFP | |
295 | // if (err == 0) | |
296 | // err |= vfp_restore_state(&aux->vfp); | |
297 | #endif | |
298 | ||
299 | return err; | |
300 | } | |
301 | ||
302 | asmlinkage int sys_sigreturn(struct pt_regs *regs) | |
303 | { | |
304 | struct sigframe __user *frame; | |
305 | sigset_t set; | |
306 | ||
307 | /* Always make any pending restarted system calls return -EINTR */ | |
308 | current_thread_info()->restart_block.fn = do_no_restart_syscall; | |
309 | ||
310 | /* | |
311 | * Since we stacked the signal on a 64-bit boundary, | |
312 | * then 'sp' should be word aligned here. If it's | |
313 | * not, then the user is trying to mess with us. | |
314 | */ | |
315 | if (regs->ARM_sp & 7) | |
316 | goto badframe; | |
317 | ||
318 | frame = (struct sigframe __user *)regs->ARM_sp; | |
319 | ||
320 | if (!access_ok(VERIFY_READ, frame, sizeof (*frame))) | |
321 | goto badframe; | |
322 | if (__get_user(set.sig[0], &frame->sc.oldmask) | |
323 | || (_NSIG_WORDS > 1 | |
324 | && __copy_from_user(&set.sig[1], &frame->extramask, | |
325 | sizeof(frame->extramask)))) | |
326 | goto badframe; | |
327 | ||
328 | sigdelsetmask(&set, ~_BLOCKABLE); | |
329 | spin_lock_irq(¤t->sighand->siglock); | |
330 | current->blocked = set; | |
331 | recalc_sigpending(); | |
332 | spin_unlock_irq(¤t->sighand->siglock); | |
333 | ||
334 | if (restore_sigcontext(regs, &frame->sc, &frame->aux)) | |
335 | goto badframe; | |
336 | ||
337 | /* Send SIGTRAP if we're single-stepping */ | |
338 | if (current->ptrace & PT_SINGLESTEP) { | |
339 | ptrace_cancel_bpt(current); | |
340 | send_sig(SIGTRAP, current, 1); | |
341 | } | |
342 | ||
343 | return regs->ARM_r0; | |
344 | ||
345 | badframe: | |
346 | force_sig(SIGSEGV, current); | |
347 | return 0; | |
348 | } | |
349 | ||
350 | asmlinkage int sys_rt_sigreturn(struct pt_regs *regs) | |
351 | { | |
352 | struct rt_sigframe __user *frame; | |
353 | sigset_t set; | |
354 | ||
355 | /* Always make any pending restarted system calls return -EINTR */ | |
356 | current_thread_info()->restart_block.fn = do_no_restart_syscall; | |
357 | ||
358 | /* | |
359 | * Since we stacked the signal on a 64-bit boundary, | |
360 | * then 'sp' should be word aligned here. If it's | |
361 | * not, then the user is trying to mess with us. | |
362 | */ | |
363 | if (regs->ARM_sp & 7) | |
364 | goto badframe; | |
365 | ||
366 | frame = (struct rt_sigframe __user *)regs->ARM_sp; | |
367 | ||
368 | if (!access_ok(VERIFY_READ, frame, sizeof (*frame))) | |
369 | goto badframe; | |
370 | if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) | |
371 | goto badframe; | |
372 | ||
373 | sigdelsetmask(&set, ~_BLOCKABLE); | |
374 | spin_lock_irq(¤t->sighand->siglock); | |
375 | current->blocked = set; | |
376 | recalc_sigpending(); | |
377 | spin_unlock_irq(¤t->sighand->siglock); | |
378 | ||
379 | if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &frame->aux)) | |
380 | goto badframe; | |
381 | ||
382 | if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->ARM_sp) == -EFAULT) | |
383 | goto badframe; | |
384 | ||
385 | /* Send SIGTRAP if we're single-stepping */ | |
386 | if (current->ptrace & PT_SINGLESTEP) { | |
387 | ptrace_cancel_bpt(current); | |
388 | send_sig(SIGTRAP, current, 1); | |
389 | } | |
390 | ||
391 | return regs->ARM_r0; | |
392 | ||
393 | badframe: | |
394 | force_sig(SIGSEGV, current); | |
395 | return 0; | |
396 | } | |
397 | ||
398 | static int | |
399 | setup_sigcontext(struct sigcontext __user *sc, struct aux_sigframe __user *aux, | |
400 | struct pt_regs *regs, unsigned long mask) | |
401 | { | |
402 | int err = 0; | |
403 | ||
404 | __put_user_error(regs->ARM_r0, &sc->arm_r0, err); | |
405 | __put_user_error(regs->ARM_r1, &sc->arm_r1, err); | |
406 | __put_user_error(regs->ARM_r2, &sc->arm_r2, err); | |
407 | __put_user_error(regs->ARM_r3, &sc->arm_r3, err); | |
408 | __put_user_error(regs->ARM_r4, &sc->arm_r4, err); | |
409 | __put_user_error(regs->ARM_r5, &sc->arm_r5, err); | |
410 | __put_user_error(regs->ARM_r6, &sc->arm_r6, err); | |
411 | __put_user_error(regs->ARM_r7, &sc->arm_r7, err); | |
412 | __put_user_error(regs->ARM_r8, &sc->arm_r8, err); | |
413 | __put_user_error(regs->ARM_r9, &sc->arm_r9, err); | |
414 | __put_user_error(regs->ARM_r10, &sc->arm_r10, err); | |
415 | __put_user_error(regs->ARM_fp, &sc->arm_fp, err); | |
416 | __put_user_error(regs->ARM_ip, &sc->arm_ip, err); | |
417 | __put_user_error(regs->ARM_sp, &sc->arm_sp, err); | |
418 | __put_user_error(regs->ARM_lr, &sc->arm_lr, err); | |
419 | __put_user_error(regs->ARM_pc, &sc->arm_pc, err); | |
420 | __put_user_error(regs->ARM_cpsr, &sc->arm_cpsr, err); | |
421 | ||
422 | __put_user_error(current->thread.trap_no, &sc->trap_no, err); | |
423 | __put_user_error(current->thread.error_code, &sc->error_code, err); | |
424 | __put_user_error(current->thread.address, &sc->fault_address, err); | |
425 | __put_user_error(mask, &sc->oldmask, err); | |
426 | ||
427 | #ifdef CONFIG_IWMMXT | |
428 | if (err == 0 && test_thread_flag(TIF_USING_IWMMXT)) | |
429 | err |= preserve_iwmmxt_context(&aux->iwmmxt); | |
430 | #endif | |
431 | #ifdef CONFIG_VFP | |
432 | // if (err == 0) | |
433 | // err |= vfp_save_state(&aux->vfp); | |
434 | #endif | |
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; | |
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 | else | |
491 | cpsr &= ~PSR_T_BIT; | |
492 | } | |
493 | #endif | |
494 | ||
495 | if (ka->sa.sa_flags & SA_RESTORER) { | |
496 | retcode = (unsigned long)ka->sa.sa_restorer; | |
497 | } else { | |
498 | unsigned int idx = thumb; | |
499 | ||
500 | if (ka->sa.sa_flags & SA_SIGINFO) | |
501 | idx += 2; | |
502 | ||
503 | if (__put_user(retcodes[idx], rc)) | |
504 | return 1; | |
505 | ||
506 | /* | |
507 | * Ensure that the instruction cache sees | |
508 | * the return code written onto the stack. | |
509 | */ | |
510 | flush_icache_range((unsigned long)rc, | |
511 | (unsigned long)(rc + 1)); | |
512 | ||
513 | retcode = ((unsigned long)rc) + thumb; | |
514 | } | |
515 | ||
516 | regs->ARM_r0 = usig; | |
517 | regs->ARM_sp = (unsigned long)frame; | |
518 | regs->ARM_lr = retcode; | |
519 | regs->ARM_pc = handler; | |
520 | regs->ARM_cpsr = cpsr; | |
521 | ||
522 | return 0; | |
523 | } | |
524 | ||
525 | static int | |
526 | setup_frame(int usig, struct k_sigaction *ka, sigset_t *set, struct pt_regs *regs) | |
527 | { | |
528 | struct sigframe __user *frame = get_sigframe(ka, regs, sizeof(*frame)); | |
529 | int err = 0; | |
530 | ||
531 | if (!frame) | |
532 | return 1; | |
533 | ||
534 | err |= setup_sigcontext(&frame->sc, &frame->aux, regs, set->sig[0]); | |
535 | ||
536 | if (_NSIG_WORDS > 1) { | |
537 | err |= __copy_to_user(frame->extramask, &set->sig[1], | |
538 | sizeof(frame->extramask)); | |
539 | } | |
540 | ||
541 | if (err == 0) | |
542 | err = setup_return(regs, ka, &frame->retcode, frame, usig); | |
543 | ||
544 | return err; | |
545 | } | |
546 | ||
547 | static int | |
548 | setup_rt_frame(int usig, struct k_sigaction *ka, siginfo_t *info, | |
549 | sigset_t *set, struct pt_regs *regs) | |
550 | { | |
551 | struct rt_sigframe __user *frame = get_sigframe(ka, regs, sizeof(*frame)); | |
552 | stack_t stack; | |
553 | int err = 0; | |
554 | ||
555 | if (!frame) | |
556 | return 1; | |
557 | ||
558 | __put_user_error(&frame->info, &frame->pinfo, err); | |
559 | __put_user_error(&frame->uc, &frame->puc, err); | |
560 | err |= copy_siginfo_to_user(&frame->info, info); | |
561 | ||
562 | __put_user_error(0, &frame->uc.uc_flags, err); | |
563 | __put_user_error(NULL, &frame->uc.uc_link, err); | |
564 | ||
565 | memset(&stack, 0, sizeof(stack)); | |
566 | stack.ss_sp = (void __user *)current->sas_ss_sp; | |
567 | stack.ss_flags = sas_ss_flags(regs->ARM_sp); | |
568 | stack.ss_size = current->sas_ss_size; | |
569 | err |= __copy_to_user(&frame->uc.uc_stack, &stack, sizeof(stack)); | |
570 | ||
571 | err |= setup_sigcontext(&frame->uc.uc_mcontext, &frame->aux, | |
572 | regs, set->sig[0]); | |
573 | err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); | |
574 | ||
575 | if (err == 0) | |
576 | err = setup_return(regs, ka, &frame->retcode, frame, usig); | |
577 | ||
578 | if (err == 0) { | |
579 | /* | |
580 | * For realtime signals we must also set the second and third | |
581 | * arguments for the signal handler. | |
582 | * -- Peter Maydell <pmaydell@chiark.greenend.org.uk> 2000-12-06 | |
583 | */ | |
584 | regs->ARM_r1 = (unsigned long)&frame->info; | |
585 | regs->ARM_r2 = (unsigned long)&frame->uc; | |
586 | } | |
587 | ||
588 | return err; | |
589 | } | |
590 | ||
591 | static inline void restart_syscall(struct pt_regs *regs) | |
592 | { | |
593 | regs->ARM_r0 = regs->ARM_ORIG_r0; | |
594 | regs->ARM_pc -= thumb_mode(regs) ? 2 : 4; | |
595 | } | |
596 | ||
597 | /* | |
598 | * OK, we're invoking a handler | |
599 | */ | |
600 | static void | |
601 | handle_signal(unsigned long sig, struct k_sigaction *ka, | |
602 | siginfo_t *info, sigset_t *oldset, | |
603 | struct pt_regs * regs, int syscall) | |
604 | { | |
605 | struct thread_info *thread = current_thread_info(); | |
606 | struct task_struct *tsk = current; | |
607 | int usig = sig; | |
608 | int ret; | |
609 | ||
610 | /* | |
611 | * If we were from a system call, check for system call restarting... | |
612 | */ | |
613 | if (syscall) { | |
614 | switch (regs->ARM_r0) { | |
615 | case -ERESTART_RESTARTBLOCK: | |
616 | case -ERESTARTNOHAND: | |
617 | regs->ARM_r0 = -EINTR; | |
618 | break; | |
619 | case -ERESTARTSYS: | |
620 | if (!(ka->sa.sa_flags & SA_RESTART)) { | |
621 | regs->ARM_r0 = -EINTR; | |
622 | break; | |
623 | } | |
624 | /* fallthrough */ | |
625 | case -ERESTARTNOINTR: | |
626 | restart_syscall(regs); | |
627 | } | |
628 | } | |
629 | ||
630 | /* | |
631 | * translate the signal | |
632 | */ | |
633 | if (usig < 32 && thread->exec_domain && thread->exec_domain->signal_invmap) | |
634 | usig = thread->exec_domain->signal_invmap[usig]; | |
635 | ||
636 | /* | |
637 | * Set up the stack frame | |
638 | */ | |
639 | if (ka->sa.sa_flags & SA_SIGINFO) | |
640 | ret = setup_rt_frame(usig, ka, info, oldset, regs); | |
641 | else | |
642 | ret = setup_frame(usig, ka, oldset, regs); | |
643 | ||
644 | /* | |
645 | * Check that the resulting registers are actually sane. | |
646 | */ | |
647 | ret |= !valid_user_regs(regs); | |
648 | ||
649 | /* | |
650 | * Block the signal if we were unsuccessful. | |
651 | */ | |
652 | if (ret != 0 || !(ka->sa.sa_flags & SA_NODEFER)) { | |
653 | spin_lock_irq(&tsk->sighand->siglock); | |
654 | sigorsets(&tsk->blocked, &tsk->blocked, | |
655 | &ka->sa.sa_mask); | |
656 | sigaddset(&tsk->blocked, sig); | |
657 | recalc_sigpending(); | |
658 | spin_unlock_irq(&tsk->sighand->siglock); | |
659 | } | |
660 | ||
661 | if (ret == 0) | |
662 | return; | |
663 | ||
664 | force_sigsegv(sig, tsk); | |
665 | } | |
666 | ||
667 | /* | |
668 | * Note that 'init' is a special process: it doesn't get signals it doesn't | |
669 | * want to handle. Thus you cannot kill init even with a SIGKILL even by | |
670 | * mistake. | |
671 | * | |
672 | * Note that we go through the signals twice: once to check the signals that | |
673 | * the kernel can handle, and then we build all the user-level signal handling | |
674 | * stack-frames in one go after that. | |
675 | */ | |
676 | static int do_signal(sigset_t *oldset, struct pt_regs *regs, int syscall) | |
677 | { | |
678 | struct k_sigaction ka; | |
679 | siginfo_t info; | |
680 | int signr; | |
681 | ||
682 | /* | |
683 | * We want the common case to go fast, which | |
684 | * is why we may in certain cases get here from | |
685 | * kernel mode. Just return without doing anything | |
686 | * if so. | |
687 | */ | |
688 | if (!user_mode(regs)) | |
689 | return 0; | |
690 | ||
691 | if (try_to_freeze(0)) | |
692 | goto no_signal; | |
693 | ||
694 | if (current->ptrace & PT_SINGLESTEP) | |
695 | ptrace_cancel_bpt(current); | |
696 | ||
697 | signr = get_signal_to_deliver(&info, &ka, regs, NULL); | |
698 | if (signr > 0) { | |
699 | handle_signal(signr, &ka, &info, oldset, regs, syscall); | |
700 | if (current->ptrace & PT_SINGLESTEP) | |
701 | ptrace_set_bpt(current); | |
702 | return 1; | |
703 | } | |
704 | ||
705 | no_signal: | |
706 | /* | |
707 | * No signal to deliver to the process - restart the syscall. | |
708 | */ | |
709 | if (syscall) { | |
710 | if (regs->ARM_r0 == -ERESTART_RESTARTBLOCK) { | |
711 | if (thumb_mode(regs)) { | |
712 | regs->ARM_r7 = __NR_restart_syscall; | |
713 | regs->ARM_pc -= 2; | |
714 | } else { | |
715 | u32 __user *usp; | |
716 | ||
717 | regs->ARM_sp -= 12; | |
718 | usp = (u32 __user *)regs->ARM_sp; | |
719 | ||
720 | put_user(regs->ARM_pc, &usp[0]); | |
721 | /* swi __NR_restart_syscall */ | |
722 | put_user(0xef000000 | __NR_restart_syscall, &usp[1]); | |
723 | /* ldr pc, [sp], #12 */ | |
724 | put_user(0xe49df00c, &usp[2]); | |
725 | ||
726 | flush_icache_range((unsigned long)usp, | |
727 | (unsigned long)(usp + 3)); | |
728 | ||
729 | regs->ARM_pc = regs->ARM_sp + 4; | |
730 | } | |
731 | } | |
732 | if (regs->ARM_r0 == -ERESTARTNOHAND || | |
733 | regs->ARM_r0 == -ERESTARTSYS || | |
734 | regs->ARM_r0 == -ERESTARTNOINTR) { | |
735 | restart_syscall(regs); | |
736 | } | |
737 | } | |
738 | if (current->ptrace & PT_SINGLESTEP) | |
739 | ptrace_set_bpt(current); | |
740 | return 0; | |
741 | } | |
742 | ||
743 | asmlinkage void | |
744 | do_notify_resume(struct pt_regs *regs, unsigned int thread_flags, int syscall) | |
745 | { | |
746 | if (thread_flags & _TIF_SIGPENDING) | |
747 | do_signal(¤t->blocked, regs, syscall); | |
748 | } |