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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" | |
e00d349e | 22 | #include "signal.h" |
1da177e4 LT |
23 | |
24 | #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) | |
25 | ||
26 | /* | |
27 | * For ARM syscalls, we encode the syscall number into the instruction. | |
28 | */ | |
29 | #define SWI_SYS_SIGRETURN (0xef000000|(__NR_sigreturn)) | |
30 | #define SWI_SYS_RT_SIGRETURN (0xef000000|(__NR_rt_sigreturn)) | |
31 | ||
32 | /* | |
33 | * For Thumb syscalls, we pass the syscall number via r7. We therefore | |
34 | * need two 16-bit instructions. | |
35 | */ | |
36 | #define SWI_THUMB_SIGRETURN (0xdf00 << 16 | 0x2700 | (__NR_sigreturn - __NR_SYSCALL_BASE)) | |
37 | #define SWI_THUMB_RT_SIGRETURN (0xdf00 << 16 | 0x2700 | (__NR_rt_sigreturn - __NR_SYSCALL_BASE)) | |
38 | ||
e00d349e | 39 | const unsigned long sigreturn_codes[4] = { |
1da177e4 LT |
40 | SWI_SYS_SIGRETURN, SWI_THUMB_SIGRETURN, |
41 | SWI_SYS_RT_SIGRETURN, SWI_THUMB_RT_SIGRETURN | |
42 | }; | |
43 | ||
44 | static int do_signal(sigset_t *oldset, struct pt_regs * regs, int syscall); | |
45 | ||
46 | /* | |
47 | * atomically swap in the new signal mask, and wait for a signal. | |
48 | */ | |
49 | asmlinkage int sys_sigsuspend(int restart, unsigned long oldmask, old_sigset_t mask, struct pt_regs *regs) | |
50 | { | |
51 | sigset_t saveset; | |
52 | ||
53 | mask &= _BLOCKABLE; | |
54 | spin_lock_irq(¤t->sighand->siglock); | |
55 | saveset = current->blocked; | |
56 | siginitset(¤t->blocked, mask); | |
57 | recalc_sigpending(); | |
58 | spin_unlock_irq(¤t->sighand->siglock); | |
59 | regs->ARM_r0 = -EINTR; | |
60 | ||
61 | while (1) { | |
62 | current->state = TASK_INTERRUPTIBLE; | |
63 | schedule(); | |
64 | if (do_signal(&saveset, regs, 0)) | |
65 | return regs->ARM_r0; | |
66 | } | |
67 | } | |
68 | ||
69 | asmlinkage int | |
70 | sys_rt_sigsuspend(sigset_t __user *unewset, size_t sigsetsize, struct pt_regs *regs) | |
71 | { | |
72 | sigset_t saveset, newset; | |
73 | ||
74 | /* XXX: Don't preclude handling different sized sigset_t's. */ | |
75 | if (sigsetsize != sizeof(sigset_t)) | |
76 | return -EINVAL; | |
77 | ||
78 | if (copy_from_user(&newset, unewset, sizeof(newset))) | |
79 | return -EFAULT; | |
80 | sigdelsetmask(&newset, ~_BLOCKABLE); | |
81 | ||
82 | spin_lock_irq(¤t->sighand->siglock); | |
83 | saveset = current->blocked; | |
84 | current->blocked = newset; | |
85 | recalc_sigpending(); | |
86 | spin_unlock_irq(¤t->sighand->siglock); | |
87 | regs->ARM_r0 = -EINTR; | |
88 | ||
89 | while (1) { | |
90 | current->state = TASK_INTERRUPTIBLE; | |
91 | schedule(); | |
92 | if (do_signal(&saveset, regs, 0)) | |
93 | return regs->ARM_r0; | |
94 | } | |
95 | } | |
96 | ||
97 | asmlinkage int | |
98 | sys_sigaction(int sig, const struct old_sigaction __user *act, | |
99 | struct old_sigaction __user *oact) | |
100 | { | |
101 | struct k_sigaction new_ka, old_ka; | |
102 | int ret; | |
103 | ||
104 | if (act) { | |
105 | old_sigset_t mask; | |
106 | if (!access_ok(VERIFY_READ, act, sizeof(*act)) || | |
107 | __get_user(new_ka.sa.sa_handler, &act->sa_handler) || | |
108 | __get_user(new_ka.sa.sa_restorer, &act->sa_restorer)) | |
109 | return -EFAULT; | |
110 | __get_user(new_ka.sa.sa_flags, &act->sa_flags); | |
111 | __get_user(mask, &act->sa_mask); | |
112 | siginitset(&new_ka.sa.sa_mask, mask); | |
113 | } | |
114 | ||
115 | ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); | |
116 | ||
117 | if (!ret && oact) { | |
118 | if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) || | |
119 | __put_user(old_ka.sa.sa_handler, &oact->sa_handler) || | |
120 | __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer)) | |
121 | return -EFAULT; | |
122 | __put_user(old_ka.sa.sa_flags, &oact->sa_flags); | |
123 | __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask); | |
124 | } | |
125 | ||
126 | return ret; | |
127 | } | |
128 | ||
129 | #ifdef CONFIG_IWMMXT | |
130 | ||
131 | /* iwmmxt_area is 0x98 bytes long, preceeded by 8 bytes of signature */ | |
132 | #define IWMMXT_STORAGE_SIZE (0x98 + 8) | |
133 | #define IWMMXT_MAGIC0 0x12ef842a | |
134 | #define IWMMXT_MAGIC1 0x1c07ca71 | |
135 | ||
136 | struct iwmmxt_sigframe { | |
137 | unsigned long magic0; | |
138 | unsigned long magic1; | |
139 | unsigned long storage[0x98/4]; | |
140 | }; | |
141 | ||
142 | static int page_present(struct mm_struct *mm, void __user *uptr, int wr) | |
143 | { | |
144 | unsigned long addr = (unsigned long)uptr; | |
145 | pgd_t *pgd = pgd_offset(mm, addr); | |
146 | if (pgd_present(*pgd)) { | |
147 | pmd_t *pmd = pmd_offset(pgd, addr); | |
148 | if (pmd_present(*pmd)) { | |
149 | pte_t *pte = pte_offset_map(pmd, addr); | |
150 | return (pte_present(*pte) && (!wr || pte_write(*pte))); | |
151 | } | |
152 | } | |
153 | return 0; | |
154 | } | |
155 | ||
156 | static int copy_locked(void __user *uptr, void *kptr, size_t size, int write, | |
157 | void (*copyfn)(void *, void __user *)) | |
158 | { | |
159 | unsigned char v, __user *userptr = uptr; | |
160 | int err = 0; | |
161 | ||
162 | do { | |
163 | struct mm_struct *mm; | |
164 | ||
165 | if (write) { | |
166 | __put_user_error(0, userptr, err); | |
167 | __put_user_error(0, userptr + size - 1, err); | |
168 | } else { | |
169 | __get_user_error(v, userptr, err); | |
170 | __get_user_error(v, userptr + size - 1, err); | |
171 | } | |
172 | ||
173 | if (err) | |
174 | break; | |
175 | ||
176 | mm = current->mm; | |
177 | spin_lock(&mm->page_table_lock); | |
178 | if (page_present(mm, userptr, write) && | |
179 | page_present(mm, userptr + size - 1, write)) { | |
180 | copyfn(kptr, uptr); | |
181 | } else | |
182 | err = 1; | |
183 | spin_unlock(&mm->page_table_lock); | |
184 | } while (err); | |
185 | ||
186 | return err; | |
187 | } | |
188 | ||
189 | static int preserve_iwmmxt_context(struct iwmmxt_sigframe *frame) | |
190 | { | |
191 | int err = 0; | |
192 | ||
193 | /* the iWMMXt context must be 64 bit aligned */ | |
194 | WARN_ON((unsigned long)frame & 7); | |
195 | ||
196 | __put_user_error(IWMMXT_MAGIC0, &frame->magic0, err); | |
197 | __put_user_error(IWMMXT_MAGIC1, &frame->magic1, err); | |
198 | ||
199 | /* | |
200 | * iwmmxt_task_copy() doesn't check user permissions. | |
201 | * Let's do a dummy write on the upper boundary to ensure | |
202 | * access to user mem is OK all way up. | |
203 | */ | |
204 | err |= copy_locked(&frame->storage, current_thread_info(), | |
205 | sizeof(frame->storage), 1, iwmmxt_task_copy); | |
206 | return err; | |
207 | } | |
208 | ||
209 | static int restore_iwmmxt_context(struct iwmmxt_sigframe *frame) | |
210 | { | |
211 | unsigned long magic0, magic1; | |
212 | int err = 0; | |
213 | ||
214 | /* the iWMMXt context is 64 bit aligned */ | |
215 | WARN_ON((unsigned long)frame & 7); | |
216 | ||
217 | /* | |
218 | * Validate iWMMXt context signature. | |
219 | * Also, iwmmxt_task_restore() doesn't check user permissions. | |
220 | * Let's do a dummy write on the upper boundary to ensure | |
221 | * access to user mem is OK all way up. | |
222 | */ | |
223 | __get_user_error(magic0, &frame->magic0, err); | |
224 | __get_user_error(magic1, &frame->magic1, err); | |
225 | if (!err && magic0 == IWMMXT_MAGIC0 && magic1 == IWMMXT_MAGIC1) | |
226 | err = copy_locked(&frame->storage, current_thread_info(), | |
227 | sizeof(frame->storage), 0, iwmmxt_task_restore); | |
228 | return err; | |
229 | } | |
230 | ||
231 | #endif | |
232 | ||
233 | /* | |
234 | * Auxiliary signal frame. This saves stuff like FP state. | |
235 | * The layout of this structure is not part of the user ABI. | |
236 | */ | |
237 | struct aux_sigframe { | |
238 | #ifdef CONFIG_IWMMXT | |
239 | struct iwmmxt_sigframe iwmmxt; | |
240 | #endif | |
241 | #ifdef CONFIG_VFP | |
242 | union vfp_state vfp; | |
243 | #endif | |
244 | }; | |
245 | ||
246 | /* | |
247 | * Do a signal return; undo the signal stack. These are aligned to 64-bit. | |
248 | */ | |
249 | struct sigframe { | |
250 | struct sigcontext sc; | |
251 | unsigned long extramask[_NSIG_WORDS-1]; | |
252 | unsigned long retcode; | |
253 | struct aux_sigframe aux __attribute__((aligned(8))); | |
254 | }; | |
255 | ||
256 | struct rt_sigframe { | |
257 | struct siginfo __user *pinfo; | |
258 | void __user *puc; | |
259 | struct siginfo info; | |
260 | struct ucontext uc; | |
261 | unsigned long retcode; | |
262 | struct aux_sigframe aux __attribute__((aligned(8))); | |
263 | }; | |
264 | ||
265 | static int | |
266 | restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, | |
267 | struct aux_sigframe __user *aux) | |
268 | { | |
269 | int err = 0; | |
270 | ||
271 | __get_user_error(regs->ARM_r0, &sc->arm_r0, err); | |
272 | __get_user_error(regs->ARM_r1, &sc->arm_r1, err); | |
273 | __get_user_error(regs->ARM_r2, &sc->arm_r2, err); | |
274 | __get_user_error(regs->ARM_r3, &sc->arm_r3, err); | |
275 | __get_user_error(regs->ARM_r4, &sc->arm_r4, err); | |
276 | __get_user_error(regs->ARM_r5, &sc->arm_r5, err); | |
277 | __get_user_error(regs->ARM_r6, &sc->arm_r6, err); | |
278 | __get_user_error(regs->ARM_r7, &sc->arm_r7, err); | |
279 | __get_user_error(regs->ARM_r8, &sc->arm_r8, err); | |
280 | __get_user_error(regs->ARM_r9, &sc->arm_r9, err); | |
281 | __get_user_error(regs->ARM_r10, &sc->arm_r10, err); | |
282 | __get_user_error(regs->ARM_fp, &sc->arm_fp, err); | |
283 | __get_user_error(regs->ARM_ip, &sc->arm_ip, err); | |
284 | __get_user_error(regs->ARM_sp, &sc->arm_sp, err); | |
285 | __get_user_error(regs->ARM_lr, &sc->arm_lr, err); | |
286 | __get_user_error(regs->ARM_pc, &sc->arm_pc, err); | |
287 | __get_user_error(regs->ARM_cpsr, &sc->arm_cpsr, err); | |
288 | ||
289 | err |= !valid_user_regs(regs); | |
290 | ||
291 | #ifdef CONFIG_IWMMXT | |
292 | if (err == 0 && test_thread_flag(TIF_USING_IWMMXT)) | |
293 | err |= restore_iwmmxt_context(&aux->iwmmxt); | |
294 | #endif | |
295 | #ifdef CONFIG_VFP | |
296 | // if (err == 0) | |
297 | // err |= vfp_restore_state(&aux->vfp); | |
298 | #endif | |
299 | ||
300 | return err; | |
301 | } | |
302 | ||
303 | asmlinkage int sys_sigreturn(struct pt_regs *regs) | |
304 | { | |
305 | struct sigframe __user *frame; | |
306 | sigset_t set; | |
307 | ||
308 | /* Always make any pending restarted system calls return -EINTR */ | |
309 | current_thread_info()->restart_block.fn = do_no_restart_syscall; | |
310 | ||
311 | /* | |
312 | * Since we stacked the signal on a 64-bit boundary, | |
313 | * then 'sp' should be word aligned here. If it's | |
314 | * not, then the user is trying to mess with us. | |
315 | */ | |
316 | if (regs->ARM_sp & 7) | |
317 | goto badframe; | |
318 | ||
319 | frame = (struct sigframe __user *)regs->ARM_sp; | |
320 | ||
321 | if (!access_ok(VERIFY_READ, frame, sizeof (*frame))) | |
322 | goto badframe; | |
323 | if (__get_user(set.sig[0], &frame->sc.oldmask) | |
324 | || (_NSIG_WORDS > 1 | |
325 | && __copy_from_user(&set.sig[1], &frame->extramask, | |
326 | sizeof(frame->extramask)))) | |
327 | goto badframe; | |
328 | ||
329 | sigdelsetmask(&set, ~_BLOCKABLE); | |
330 | spin_lock_irq(¤t->sighand->siglock); | |
331 | current->blocked = set; | |
332 | recalc_sigpending(); | |
333 | spin_unlock_irq(¤t->sighand->siglock); | |
334 | ||
335 | if (restore_sigcontext(regs, &frame->sc, &frame->aux)) | |
336 | goto badframe; | |
337 | ||
338 | /* Send SIGTRAP if we're single-stepping */ | |
339 | if (current->ptrace & PT_SINGLESTEP) { | |
340 | ptrace_cancel_bpt(current); | |
341 | send_sig(SIGTRAP, current, 1); | |
342 | } | |
343 | ||
344 | return regs->ARM_r0; | |
345 | ||
346 | badframe: | |
347 | force_sig(SIGSEGV, current); | |
348 | return 0; | |
349 | } | |
350 | ||
351 | asmlinkage int sys_rt_sigreturn(struct pt_regs *regs) | |
352 | { | |
353 | struct rt_sigframe __user *frame; | |
354 | sigset_t set; | |
355 | ||
356 | /* Always make any pending restarted system calls return -EINTR */ | |
357 | current_thread_info()->restart_block.fn = do_no_restart_syscall; | |
358 | ||
359 | /* | |
360 | * Since we stacked the signal on a 64-bit boundary, | |
361 | * then 'sp' should be word aligned here. If it's | |
362 | * not, then the user is trying to mess with us. | |
363 | */ | |
364 | if (regs->ARM_sp & 7) | |
365 | goto badframe; | |
366 | ||
367 | frame = (struct rt_sigframe __user *)regs->ARM_sp; | |
368 | ||
369 | if (!access_ok(VERIFY_READ, frame, sizeof (*frame))) | |
370 | goto badframe; | |
371 | if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) | |
372 | goto badframe; | |
373 | ||
374 | sigdelsetmask(&set, ~_BLOCKABLE); | |
375 | spin_lock_irq(¤t->sighand->siglock); | |
376 | current->blocked = set; | |
377 | recalc_sigpending(); | |
378 | spin_unlock_irq(¤t->sighand->siglock); | |
379 | ||
380 | if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &frame->aux)) | |
381 | goto badframe; | |
382 | ||
383 | if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->ARM_sp) == -EFAULT) | |
384 | goto badframe; | |
385 | ||
386 | /* Send SIGTRAP if we're single-stepping */ | |
387 | if (current->ptrace & PT_SINGLESTEP) { | |
388 | ptrace_cancel_bpt(current); | |
389 | send_sig(SIGTRAP, current, 1); | |
390 | } | |
391 | ||
392 | return regs->ARM_r0; | |
393 | ||
394 | badframe: | |
395 | force_sig(SIGSEGV, current); | |
396 | return 0; | |
397 | } | |
398 | ||
399 | static int | |
400 | setup_sigcontext(struct sigcontext __user *sc, struct aux_sigframe __user *aux, | |
401 | struct pt_regs *regs, unsigned long mask) | |
402 | { | |
403 | int err = 0; | |
404 | ||
405 | __put_user_error(regs->ARM_r0, &sc->arm_r0, err); | |
406 | __put_user_error(regs->ARM_r1, &sc->arm_r1, err); | |
407 | __put_user_error(regs->ARM_r2, &sc->arm_r2, err); | |
408 | __put_user_error(regs->ARM_r3, &sc->arm_r3, err); | |
409 | __put_user_error(regs->ARM_r4, &sc->arm_r4, err); | |
410 | __put_user_error(regs->ARM_r5, &sc->arm_r5, err); | |
411 | __put_user_error(regs->ARM_r6, &sc->arm_r6, err); | |
412 | __put_user_error(regs->ARM_r7, &sc->arm_r7, err); | |
413 | __put_user_error(regs->ARM_r8, &sc->arm_r8, err); | |
414 | __put_user_error(regs->ARM_r9, &sc->arm_r9, err); | |
415 | __put_user_error(regs->ARM_r10, &sc->arm_r10, err); | |
416 | __put_user_error(regs->ARM_fp, &sc->arm_fp, err); | |
417 | __put_user_error(regs->ARM_ip, &sc->arm_ip, err); | |
418 | __put_user_error(regs->ARM_sp, &sc->arm_sp, err); | |
419 | __put_user_error(regs->ARM_lr, &sc->arm_lr, err); | |
420 | __put_user_error(regs->ARM_pc, &sc->arm_pc, err); | |
421 | __put_user_error(regs->ARM_cpsr, &sc->arm_cpsr, err); | |
422 | ||
423 | __put_user_error(current->thread.trap_no, &sc->trap_no, err); | |
424 | __put_user_error(current->thread.error_code, &sc->error_code, err); | |
425 | __put_user_error(current->thread.address, &sc->fault_address, err); | |
426 | __put_user_error(mask, &sc->oldmask, err); | |
427 | ||
428 | #ifdef CONFIG_IWMMXT | |
429 | if (err == 0 && test_thread_flag(TIF_USING_IWMMXT)) | |
430 | err |= preserve_iwmmxt_context(&aux->iwmmxt); | |
431 | #endif | |
432 | #ifdef CONFIG_VFP | |
433 | // if (err == 0) | |
434 | // err |= vfp_save_state(&aux->vfp); | |
435 | #endif | |
436 | ||
437 | return err; | |
438 | } | |
439 | ||
440 | static inline void __user * | |
441 | get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, int framesize) | |
442 | { | |
443 | unsigned long sp = regs->ARM_sp; | |
444 | void __user *frame; | |
445 | ||
446 | /* | |
447 | * This is the X/Open sanctioned signal stack switching. | |
448 | */ | |
449 | if ((ka->sa.sa_flags & SA_ONSTACK) && !sas_ss_flags(sp)) | |
450 | sp = current->sas_ss_sp + current->sas_ss_size; | |
451 | ||
452 | /* | |
453 | * ATPCS B01 mandates 8-byte alignment | |
454 | */ | |
455 | frame = (void __user *)((sp - framesize) & ~7); | |
456 | ||
457 | /* | |
458 | * Check that we can actually write to the signal frame. | |
459 | */ | |
460 | if (!access_ok(VERIFY_WRITE, frame, framesize)) | |
461 | frame = NULL; | |
462 | ||
463 | return frame; | |
464 | } | |
465 | ||
466 | static int | |
467 | setup_return(struct pt_regs *regs, struct k_sigaction *ka, | |
468 | unsigned long __user *rc, void __user *frame, int usig) | |
469 | { | |
470 | unsigned long handler = (unsigned long)ka->sa.sa_handler; | |
471 | unsigned long retcode; | |
472 | int thumb = 0; | |
473 | unsigned long cpsr = regs->ARM_cpsr & ~PSR_f; | |
474 | ||
475 | /* | |
476 | * Maybe we need to deliver a 32-bit signal to a 26-bit task. | |
477 | */ | |
478 | if (ka->sa.sa_flags & SA_THIRTYTWO) | |
479 | cpsr = (cpsr & ~MODE_MASK) | USR_MODE; | |
480 | ||
481 | #ifdef CONFIG_ARM_THUMB | |
482 | if (elf_hwcap & HWCAP_THUMB) { | |
483 | /* | |
484 | * The LSB of the handler determines if we're going to | |
485 | * be using THUMB or ARM mode for this signal handler. | |
486 | */ | |
487 | thumb = handler & 1; | |
488 | ||
489 | if (thumb) | |
490 | cpsr |= PSR_T_BIT; | |
491 | else | |
492 | cpsr &= ~PSR_T_BIT; | |
493 | } | |
494 | #endif | |
495 | ||
496 | if (ka->sa.sa_flags & SA_RESTORER) { | |
497 | retcode = (unsigned long)ka->sa.sa_restorer; | |
498 | } else { | |
499 | unsigned int idx = thumb; | |
500 | ||
501 | if (ka->sa.sa_flags & SA_SIGINFO) | |
502 | idx += 2; | |
503 | ||
e00d349e | 504 | if (__put_user(sigreturn_codes[idx], rc)) |
1da177e4 LT |
505 | return 1; |
506 | ||
e00d349e RK |
507 | if (cpsr & MODE32_BIT) { |
508 | /* | |
509 | * 32-bit code can use the new high-page | |
510 | * signal return code support. | |
511 | */ | |
512 | retcode = KERN_SIGRETURN_CODE + (idx << 2) + thumb; | |
513 | } else { | |
514 | /* | |
515 | * Ensure that the instruction cache sees | |
516 | * the return code written onto the stack. | |
517 | */ | |
518 | flush_icache_range((unsigned long)rc, | |
519 | (unsigned long)(rc + 1)); | |
520 | ||
521 | retcode = ((unsigned long)rc) + thumb; | |
522 | } | |
1da177e4 LT |
523 | } |
524 | ||
525 | regs->ARM_r0 = usig; | |
526 | regs->ARM_sp = (unsigned long)frame; | |
527 | regs->ARM_lr = retcode; | |
528 | regs->ARM_pc = handler; | |
529 | regs->ARM_cpsr = cpsr; | |
530 | ||
531 | return 0; | |
532 | } | |
533 | ||
534 | static int | |
535 | setup_frame(int usig, struct k_sigaction *ka, sigset_t *set, struct pt_regs *regs) | |
536 | { | |
537 | struct sigframe __user *frame = get_sigframe(ka, regs, sizeof(*frame)); | |
538 | int err = 0; | |
539 | ||
540 | if (!frame) | |
541 | return 1; | |
542 | ||
543 | err |= setup_sigcontext(&frame->sc, &frame->aux, regs, set->sig[0]); | |
544 | ||
545 | if (_NSIG_WORDS > 1) { | |
546 | err |= __copy_to_user(frame->extramask, &set->sig[1], | |
547 | sizeof(frame->extramask)); | |
548 | } | |
549 | ||
550 | if (err == 0) | |
551 | err = setup_return(regs, ka, &frame->retcode, frame, usig); | |
552 | ||
553 | return err; | |
554 | } | |
555 | ||
556 | static int | |
557 | setup_rt_frame(int usig, struct k_sigaction *ka, siginfo_t *info, | |
558 | sigset_t *set, struct pt_regs *regs) | |
559 | { | |
560 | struct rt_sigframe __user *frame = get_sigframe(ka, regs, sizeof(*frame)); | |
561 | stack_t stack; | |
562 | int err = 0; | |
563 | ||
564 | if (!frame) | |
565 | return 1; | |
566 | ||
567 | __put_user_error(&frame->info, &frame->pinfo, err); | |
568 | __put_user_error(&frame->uc, &frame->puc, err); | |
569 | err |= copy_siginfo_to_user(&frame->info, info); | |
570 | ||
571 | __put_user_error(0, &frame->uc.uc_flags, err); | |
572 | __put_user_error(NULL, &frame->uc.uc_link, err); | |
573 | ||
574 | memset(&stack, 0, sizeof(stack)); | |
575 | stack.ss_sp = (void __user *)current->sas_ss_sp; | |
576 | stack.ss_flags = sas_ss_flags(regs->ARM_sp); | |
577 | stack.ss_size = current->sas_ss_size; | |
578 | err |= __copy_to_user(&frame->uc.uc_stack, &stack, sizeof(stack)); | |
579 | ||
580 | err |= setup_sigcontext(&frame->uc.uc_mcontext, &frame->aux, | |
581 | regs, set->sig[0]); | |
582 | err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); | |
583 | ||
584 | if (err == 0) | |
585 | err = setup_return(regs, ka, &frame->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->uc; | |
595 | } | |
596 | ||
597 | return err; | |
598 | } | |
599 | ||
600 | static inline void restart_syscall(struct pt_regs *regs) | |
601 | { | |
602 | regs->ARM_r0 = regs->ARM_ORIG_r0; | |
603 | regs->ARM_pc -= thumb_mode(regs) ? 2 : 4; | |
604 | } | |
605 | ||
606 | /* | |
607 | * OK, we're invoking a handler | |
608 | */ | |
609 | static void | |
610 | handle_signal(unsigned long sig, struct k_sigaction *ka, | |
611 | siginfo_t *info, sigset_t *oldset, | |
612 | struct pt_regs * regs, int syscall) | |
613 | { | |
614 | struct thread_info *thread = current_thread_info(); | |
615 | struct task_struct *tsk = current; | |
616 | int usig = sig; | |
617 | int ret; | |
618 | ||
619 | /* | |
620 | * If we were from a system call, check for system call restarting... | |
621 | */ | |
622 | if (syscall) { | |
623 | switch (regs->ARM_r0) { | |
624 | case -ERESTART_RESTARTBLOCK: | |
625 | case -ERESTARTNOHAND: | |
626 | regs->ARM_r0 = -EINTR; | |
627 | break; | |
628 | case -ERESTARTSYS: | |
629 | if (!(ka->sa.sa_flags & SA_RESTART)) { | |
630 | regs->ARM_r0 = -EINTR; | |
631 | break; | |
632 | } | |
633 | /* fallthrough */ | |
634 | case -ERESTARTNOINTR: | |
635 | restart_syscall(regs); | |
636 | } | |
637 | } | |
638 | ||
639 | /* | |
640 | * translate the signal | |
641 | */ | |
642 | if (usig < 32 && thread->exec_domain && thread->exec_domain->signal_invmap) | |
643 | usig = thread->exec_domain->signal_invmap[usig]; | |
644 | ||
645 | /* | |
646 | * Set up the stack frame | |
647 | */ | |
648 | if (ka->sa.sa_flags & SA_SIGINFO) | |
649 | ret = setup_rt_frame(usig, ka, info, oldset, regs); | |
650 | else | |
651 | ret = setup_frame(usig, ka, oldset, regs); | |
652 | ||
653 | /* | |
654 | * Check that the resulting registers are actually sane. | |
655 | */ | |
656 | ret |= !valid_user_regs(regs); | |
657 | ||
658 | /* | |
659 | * Block the signal if we were unsuccessful. | |
660 | */ | |
661 | if (ret != 0 || !(ka->sa.sa_flags & SA_NODEFER)) { | |
662 | spin_lock_irq(&tsk->sighand->siglock); | |
663 | sigorsets(&tsk->blocked, &tsk->blocked, | |
664 | &ka->sa.sa_mask); | |
665 | sigaddset(&tsk->blocked, sig); | |
666 | recalc_sigpending(); | |
667 | spin_unlock_irq(&tsk->sighand->siglock); | |
668 | } | |
669 | ||
670 | if (ret == 0) | |
671 | return; | |
672 | ||
673 | force_sigsegv(sig, tsk); | |
674 | } | |
675 | ||
676 | /* | |
677 | * Note that 'init' is a special process: it doesn't get signals it doesn't | |
678 | * want to handle. Thus you cannot kill init even with a SIGKILL even by | |
679 | * mistake. | |
680 | * | |
681 | * Note that we go through the signals twice: once to check the signals that | |
682 | * the kernel can handle, and then we build all the user-level signal handling | |
683 | * stack-frames in one go after that. | |
684 | */ | |
685 | static int do_signal(sigset_t *oldset, struct pt_regs *regs, int syscall) | |
686 | { | |
687 | struct k_sigaction ka; | |
688 | siginfo_t info; | |
689 | int signr; | |
690 | ||
691 | /* | |
692 | * We want the common case to go fast, which | |
693 | * is why we may in certain cases get here from | |
694 | * kernel mode. Just return without doing anything | |
695 | * if so. | |
696 | */ | |
697 | if (!user_mode(regs)) | |
698 | return 0; | |
699 | ||
700 | if (try_to_freeze(0)) | |
701 | goto no_signal; | |
702 | ||
703 | if (current->ptrace & PT_SINGLESTEP) | |
704 | ptrace_cancel_bpt(current); | |
705 | ||
706 | signr = get_signal_to_deliver(&info, &ka, regs, NULL); | |
707 | if (signr > 0) { | |
708 | handle_signal(signr, &ka, &info, oldset, regs, syscall); | |
709 | if (current->ptrace & PT_SINGLESTEP) | |
710 | ptrace_set_bpt(current); | |
711 | return 1; | |
712 | } | |
713 | ||
714 | no_signal: | |
715 | /* | |
716 | * No signal to deliver to the process - restart the syscall. | |
717 | */ | |
718 | if (syscall) { | |
719 | if (regs->ARM_r0 == -ERESTART_RESTARTBLOCK) { | |
720 | if (thumb_mode(regs)) { | |
721 | regs->ARM_r7 = __NR_restart_syscall; | |
722 | regs->ARM_pc -= 2; | |
723 | } else { | |
724 | u32 __user *usp; | |
725 | ||
726 | regs->ARM_sp -= 12; | |
727 | usp = (u32 __user *)regs->ARM_sp; | |
728 | ||
729 | put_user(regs->ARM_pc, &usp[0]); | |
730 | /* swi __NR_restart_syscall */ | |
731 | put_user(0xef000000 | __NR_restart_syscall, &usp[1]); | |
732 | /* ldr pc, [sp], #12 */ | |
733 | put_user(0xe49df00c, &usp[2]); | |
734 | ||
735 | flush_icache_range((unsigned long)usp, | |
736 | (unsigned long)(usp + 3)); | |
737 | ||
738 | regs->ARM_pc = regs->ARM_sp + 4; | |
739 | } | |
740 | } | |
741 | if (regs->ARM_r0 == -ERESTARTNOHAND || | |
742 | regs->ARM_r0 == -ERESTARTSYS || | |
743 | regs->ARM_r0 == -ERESTARTNOINTR) { | |
744 | restart_syscall(regs); | |
745 | } | |
746 | } | |
747 | if (current->ptrace & PT_SINGLESTEP) | |
748 | ptrace_set_bpt(current); | |
749 | return 0; | |
750 | } | |
751 | ||
752 | asmlinkage void | |
753 | do_notify_resume(struct pt_regs *regs, unsigned int thread_flags, int syscall) | |
754 | { | |
755 | if (thread_flags & _TIF_SIGPENDING) | |
756 | do_signal(¤t->blocked, regs, syscall); | |
757 | } |