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[ARM] Include asm/elf.h instead of asm/procinfo.h
[deliverable/linux.git] / arch / arm / kernel / signal.c
CommitLineData
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 */
1da177e4
LT		 10#include <linux/errno.h>
11#include <linux/signal.h>
12#include <linux/ptrace.h>
13#include <linux/personality.h>
14
ee90dabc 15#include <asm/elf.h>
1da177e4
LT		 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
fcca538b
NP		 32/*
33 * With EABI, the syscall number has to be loaded into r7.
34 */
35#define MOV_R7_NR_SIGRETURN (0xe3a07000 | (__NR_sigreturn - __NR_SYSCALL_BASE))
36#define MOV_R7_NR_RT_SIGRETURN (0xe3a07000 | (__NR_rt_sigreturn - __NR_SYSCALL_BASE))
37
1da177e4
LT		 38/*
39 * For Thumb syscalls, we pass the syscall number via r7. We therefore
40 * need two 16-bit instructions.
41 */
42#define SWI_THUMB_SIGRETURN (0xdf00 << 16 | 0x2700 | (__NR_sigreturn - __NR_SYSCALL_BASE))
43#define SWI_THUMB_RT_SIGRETURN (0xdf00 << 16 | 0x2700 | (__NR_rt_sigreturn - __NR_SYSCALL_BASE))
44
fcca538b
NP		 45const unsigned long sigreturn_codes[7] = {
46 MOV_R7_NR_SIGRETURN, SWI_SYS_SIGRETURN, SWI_THUMB_SIGRETURN,
47 MOV_R7_NR_RT_SIGRETURN, SWI_SYS_RT_SIGRETURN, SWI_THUMB_RT_SIGRETURN,
1da177e4
LT		 48};
49
50static int do_signal(sigset_t *oldset, struct pt_regs * regs, int syscall);
51
52/*
53 * atomically swap in the new signal mask, and wait for a signal.
54 */
55asmlinkage int sys_sigsuspend(int restart, unsigned long oldmask, old_sigset_t mask, struct pt_regs *regs)
56{
57 sigset_t saveset;
58
59 mask &= _BLOCKABLE;
60 spin_lock_irq(&current->sighand->siglock);
61 saveset = current->blocked;
62 siginitset(&current->blocked, mask);
63 recalc_sigpending();
64 spin_unlock_irq(&current->sighand->siglock);
65 regs->ARM_r0 = -EINTR;
66
67 while (1) {
68 current->state = TASK_INTERRUPTIBLE;
69 schedule();
70 if (do_signal(&saveset, regs, 0))
71 return regs->ARM_r0;
72 }
73}
74
75asmlinkage int
76sys_rt_sigsuspend(sigset_t __user *unewset, size_t sigsetsize, struct pt_regs *regs)
77{
78 sigset_t saveset, newset;
79
80 /* XXX: Don't preclude handling different sized sigset_t's. */
81 if (sigsetsize != sizeof(sigset_t))
82 return -EINVAL;
83
84 if (copy_from_user(&newset, unewset, sizeof(newset)))
85 return -EFAULT;
86 sigdelsetmask(&newset, ~_BLOCKABLE);
87
88 spin_lock_irq(&current->sighand->siglock);
89 saveset = current->blocked;
90 current->blocked = newset;
91 recalc_sigpending();
92 spin_unlock_irq(&current->sighand->siglock);
93 regs->ARM_r0 = -EINTR;
94
95 while (1) {
96 current->state = TASK_INTERRUPTIBLE;
97 schedule();
98 if (do_signal(&saveset, regs, 0))
99 return regs->ARM_r0;
100 }
101}
102
103asmlinkage int
104sys_sigaction(int sig, const struct old_sigaction __user *act,
105 struct old_sigaction __user *oact)
106{
107 struct k_sigaction new_ka, old_ka;
108 int ret;
109
110 if (act) {
111 old_sigset_t mask;
112 if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
113 __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
114 __get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
115 return -EFAULT;
116 __get_user(new_ka.sa.sa_flags, &act->sa_flags);
117 __get_user(mask, &act->sa_mask);
118 siginitset(&new_ka.sa.sa_mask, mask);
119 }
120
121 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
122
123 if (!ret && oact) {
124 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
125 __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
126 __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
127 return -EFAULT;
128 __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
129 __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
130 }
131
132 return ret;
133}
134
3bec6ded
LB		 135#ifdef CONFIG_CRUNCH
136static int preserve_crunch_context(struct crunch_sigframe *frame)
137{
138 char kbuf[sizeof(*frame) + 8];
139 struct crunch_sigframe *kframe;
140
141 /* the crunch context must be 64 bit aligned */
142 kframe = (struct crunch_sigframe *)((unsigned long)(kbuf + 8) & ~7);
143 kframe->magic = CRUNCH_MAGIC;
144 kframe->size = CRUNCH_STORAGE_SIZE;
145 crunch_task_copy(current_thread_info(), &kframe->storage);
146 return __copy_to_user(frame, kframe, sizeof(*frame));
147}
148
149static int restore_crunch_context(struct crunch_sigframe *frame)
150{
151 char kbuf[sizeof(*frame) + 8];
152 struct crunch_sigframe *kframe;
153
154 /* the crunch context must be 64 bit aligned */
155 kframe = (struct crunch_sigframe *)((unsigned long)(kbuf + 8) & ~7);
156 if (__copy_from_user(kframe, frame, sizeof(*frame)))
157 return -1;
158 if (kframe->magic != CRUNCH_MAGIC ||
159 kframe->size != CRUNCH_STORAGE_SIZE)
160 return -1;
161 crunch_task_restore(current_thread_info(), &kframe->storage);
162 return 0;
163}
164#endif
165
1da177e4
LT		 166#ifdef CONFIG_IWMMXT
167
1da177e4
LT		 168static int preserve_iwmmxt_context(struct iwmmxt_sigframe *frame)
169{
69b04754
HD		 170 char kbuf[sizeof(*frame) + 8];
171 struct iwmmxt_sigframe *kframe;
1da177e4
LT		 172
173 /* the iWMMXt context must be 64 bit aligned */
69b04754 174 kframe = (struct iwmmxt_sigframe *)((unsigned long)(kbuf + 8) & ~7);
85fe0681
DJ		 175 kframe->magic = IWMMXT_MAGIC;
176 kframe->size = IWMMXT_STORAGE_SIZE;
69b04754
HD		 177 iwmmxt_task_copy(current_thread_info(), &kframe->storage);
178 return __copy_to_user(frame, kframe, sizeof(*frame));
1da177e4
LT		 179}
180
181static int restore_iwmmxt_context(struct iwmmxt_sigframe *frame)
182{
69b04754
HD		 183 char kbuf[sizeof(*frame) + 8];
184 struct iwmmxt_sigframe *kframe;
185
186 /* the iWMMXt context must be 64 bit aligned */
187 kframe = (struct iwmmxt_sigframe *)((unsigned long)(kbuf + 8) & ~7);
188 if (__copy_from_user(kframe, frame, sizeof(*frame)))
189 return -1;
85fe0681
DJ		 190 if (kframe->magic != IWMMXT_MAGIC ||
191 kframe->size != IWMMXT_STORAGE_SIZE)
69b04754
HD		 192 return -1;
193 iwmmxt_task_restore(current_thread_info(), &kframe->storage);
194 return 0;
1da177e4
LT		 195}
196
197#endif
198
1da177e4
LT		 199/*
200 * Do a signal return; undo the signal stack. These are aligned to 64-bit.
201 */
202struct sigframe {
7d4fdc19 203 struct ucontext uc;
fcca538b 204 unsigned long retcode[2];
1da177e4
LT		 205};
206
207struct rt_sigframe {
1da177e4 208 struct siginfo info;
cb3504e8 209 struct sigframe sig;
1da177e4
LT		 210};
211
68071484 212static int restore_sigframe(struct pt_regs *regs, struct sigframe __user *sf)
1da177e4 213{
85fe0681 214 struct aux_sigframe __user *aux;
68071484
RK		 215 sigset_t set;
216 int err;
217
218 err = __copy_from_user(&set, &sf->uc.uc_sigmask, sizeof(set));
219 if (err == 0) {
220 sigdelsetmask(&set, ~_BLOCKABLE);
221 spin_lock_irq(&current->sighand->siglock);
222 current->blocked = set;
223 recalc_sigpending();
224 spin_unlock_irq(&current->sighand->siglock);
225 }
1da177e4 226
68071484
RK		 227 __get_user_error(regs->ARM_r0, &sf->uc.uc_mcontext.arm_r0, err);
228 __get_user_error(regs->ARM_r1, &sf->uc.uc_mcontext.arm_r1, err);
229 __get_user_error(regs->ARM_r2, &sf->uc.uc_mcontext.arm_r2, err);
230 __get_user_error(regs->ARM_r3, &sf->uc.uc_mcontext.arm_r3, err);
231 __get_user_error(regs->ARM_r4, &sf->uc.uc_mcontext.arm_r4, err);
232 __get_user_error(regs->ARM_r5, &sf->uc.uc_mcontext.arm_r5, err);
233 __get_user_error(regs->ARM_r6, &sf->uc.uc_mcontext.arm_r6, err);
234 __get_user_error(regs->ARM_r7, &sf->uc.uc_mcontext.arm_r7, err);
235 __get_user_error(regs->ARM_r8, &sf->uc.uc_mcontext.arm_r8, err);
236 __get_user_error(regs->ARM_r9, &sf->uc.uc_mcontext.arm_r9, err);
237 __get_user_error(regs->ARM_r10, &sf->uc.uc_mcontext.arm_r10, err);
238 __get_user_error(regs->ARM_fp, &sf->uc.uc_mcontext.arm_fp, err);
239 __get_user_error(regs->ARM_ip, &sf->uc.uc_mcontext.arm_ip, err);
240 __get_user_error(regs->ARM_sp, &sf->uc.uc_mcontext.arm_sp, err);
241 __get_user_error(regs->ARM_lr, &sf->uc.uc_mcontext.arm_lr, err);
242 __get_user_error(regs->ARM_pc, &sf->uc.uc_mcontext.arm_pc, err);
243 __get_user_error(regs->ARM_cpsr, &sf->uc.uc_mcontext.arm_cpsr, err);
1da177e4
LT		 244
245 err |= !valid_user_regs(regs);
246
85fe0681 247 aux = (struct aux_sigframe __user *) sf->uc.uc_regspace;
3bec6ded
LB		 248#ifdef CONFIG_CRUNCH
249 if (err == 0)
250 err |= restore_crunch_context(&aux->crunch);
251#endif
1da177e4
LT		 252#ifdef CONFIG_IWMMXT
253 if (err == 0 && test_thread_flag(TIF_USING_IWMMXT))
254 err |= restore_iwmmxt_context(&aux->iwmmxt);
255#endif
256#ifdef CONFIG_VFP
257// if (err == 0)
68071484 258// err |= vfp_restore_state(&sf->aux.vfp);
1da177e4
LT		 259#endif
260
261 return err;
262}
263
264asmlinkage int sys_sigreturn(struct pt_regs *regs)
265{
266 struct sigframe __user *frame;
1da177e4
LT		 267
268 /* Always make any pending restarted system calls return -EINTR */
269 current_thread_info()->restart_block.fn = do_no_restart_syscall;
270
271 /*
272 * Since we stacked the signal on a 64-bit boundary,
273 * then 'sp' should be word aligned here. If it's
274 * not, then the user is trying to mess with us.
275 */
276 if (regs->ARM_sp & 7)
277 goto badframe;
278
279 frame = (struct sigframe __user *)regs->ARM_sp;
280
281 if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
282 goto badframe;
1da177e4 283
68071484 284 if (restore_sigframe(regs, frame))
1da177e4
LT		 285 goto badframe;
286
287 /* Send SIGTRAP if we're single-stepping */
288 if (current->ptrace & PT_SINGLESTEP) {
289 ptrace_cancel_bpt(current);
290 send_sig(SIGTRAP, current, 1);
291 }
292
293 return regs->ARM_r0;
294
295badframe:
296 force_sig(SIGSEGV, current);
297 return 0;
298}
299
300asmlinkage int sys_rt_sigreturn(struct pt_regs *regs)
301{
302 struct rt_sigframe __user *frame;
1da177e4
LT		 303
304 /* Always make any pending restarted system calls return -EINTR */
305 current_thread_info()->restart_block.fn = do_no_restart_syscall;
306
307 /*
308 * Since we stacked the signal on a 64-bit boundary,
309 * then 'sp' should be word aligned here. If it's
310 * not, then the user is trying to mess with us.
311 */
312 if (regs->ARM_sp & 7)
313 goto badframe;
314
315 frame = (struct rt_sigframe __user *)regs->ARM_sp;
316
317 if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
318 goto badframe;
1da177e4 319
68071484 320 if (restore_sigframe(regs, &frame->sig))
1da177e4
LT		 321 goto badframe;
322
cb3504e8 323 if (do_sigaltstack(&frame->sig.uc.uc_stack, NULL, regs->ARM_sp) == -EFAULT)
1da177e4
LT		 324 goto badframe;
325
326 /* Send SIGTRAP if we're single-stepping */
327 if (current->ptrace & PT_SINGLESTEP) {
328 ptrace_cancel_bpt(current);
329 send_sig(SIGTRAP, current, 1);
330 }
331
332 return regs->ARM_r0;
333
334badframe:
335 force_sig(SIGSEGV, current);
336 return 0;
337}
338
339static int
aca6ca10 340setup_sigframe(struct sigframe __user *sf, struct pt_regs *regs, sigset_t *set)
1da177e4 341{
85fe0681 342 struct aux_sigframe __user *aux;
1da177e4
LT		 343 int err = 0;
344
aca6ca10
RK		 345 __put_user_error(regs->ARM_r0, &sf->uc.uc_mcontext.arm_r0, err);
346 __put_user_error(regs->ARM_r1, &sf->uc.uc_mcontext.arm_r1, err);
347 __put_user_error(regs->ARM_r2, &sf->uc.uc_mcontext.arm_r2, err);
348 __put_user_error(regs->ARM_r3, &sf->uc.uc_mcontext.arm_r3, err);
349 __put_user_error(regs->ARM_r4, &sf->uc.uc_mcontext.arm_r4, err);
350 __put_user_error(regs->ARM_r5, &sf->uc.uc_mcontext.arm_r5, err);
351 __put_user_error(regs->ARM_r6, &sf->uc.uc_mcontext.arm_r6, err);
352 __put_user_error(regs->ARM_r7, &sf->uc.uc_mcontext.arm_r7, err);
353 __put_user_error(regs->ARM_r8, &sf->uc.uc_mcontext.arm_r8, err);
354 __put_user_error(regs->ARM_r9, &sf->uc.uc_mcontext.arm_r9, err);
355 __put_user_error(regs->ARM_r10, &sf->uc.uc_mcontext.arm_r10, err);
356 __put_user_error(regs->ARM_fp, &sf->uc.uc_mcontext.arm_fp, err);
357 __put_user_error(regs->ARM_ip, &sf->uc.uc_mcontext.arm_ip, err);
358 __put_user_error(regs->ARM_sp, &sf->uc.uc_mcontext.arm_sp, err);
359 __put_user_error(regs->ARM_lr, &sf->uc.uc_mcontext.arm_lr, err);
360 __put_user_error(regs->ARM_pc, &sf->uc.uc_mcontext.arm_pc, err);
361 __put_user_error(regs->ARM_cpsr, &sf->uc.uc_mcontext.arm_cpsr, err);
362
363 __put_user_error(current->thread.trap_no, &sf->uc.uc_mcontext.trap_no, err);
364 __put_user_error(current->thread.error_code, &sf->uc.uc_mcontext.error_code, err);
365 __put_user_error(current->thread.address, &sf->uc.uc_mcontext.fault_address, err);
366 __put_user_error(set->sig[0], &sf->uc.uc_mcontext.oldmask, err);
367
368 err |= __copy_to_user(&sf->uc.uc_sigmask, set, sizeof(*set));
1da177e4 369
85fe0681 370 aux = (struct aux_sigframe __user *) sf->uc.uc_regspace;
3bec6ded
LB		 371#ifdef CONFIG_CRUNCH
372 if (err == 0)
373 err |= preserve_crunch_context(&aux->crunch);
374#endif
1da177e4
LT		 375#ifdef CONFIG_IWMMXT
376 if (err == 0 && test_thread_flag(TIF_USING_IWMMXT))
377 err |= preserve_iwmmxt_context(&aux->iwmmxt);
378#endif
379#ifdef CONFIG_VFP
380// if (err == 0)
aca6ca10 381// err |= vfp_save_state(&sf->aux.vfp);
1da177e4 382#endif
85fe0681 383 __put_user_error(0, &aux->end_magic, err);
1da177e4
LT		 384
385 return err;
386}
387
388static inline void __user *
389get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, int framesize)
390{
391 unsigned long sp = regs->ARM_sp;
392 void __user *frame;
393
394 /*
395 * This is the X/Open sanctioned signal stack switching.
396 */
397 if ((ka->sa.sa_flags & SA_ONSTACK) && !sas_ss_flags(sp))
398 sp = current->sas_ss_sp + current->sas_ss_size;
399
400 /*
401 * ATPCS B01 mandates 8-byte alignment
402 */
403 frame = (void __user *)((sp - framesize) & ~7);
404
405 /*
406 * Check that we can actually write to the signal frame.
407 */
408 if (!access_ok(VERIFY_WRITE, frame, framesize))
409 frame = NULL;
410
411 return frame;
412}
413
414static int
415setup_return(struct pt_regs *regs, struct k_sigaction *ka,
416 unsigned long __user *rc, void __user *frame, int usig)
417{
418 unsigned long handler = (unsigned long)ka->sa.sa_handler;
419 unsigned long retcode;
420 int thumb = 0;
421 unsigned long cpsr = regs->ARM_cpsr & ~PSR_f;
422
423 /*
424 * Maybe we need to deliver a 32-bit signal to a 26-bit task.
425 */
426 if (ka->sa.sa_flags & SA_THIRTYTWO)
427 cpsr = (cpsr & ~MODE_MASK) | USR_MODE;
428
429#ifdef CONFIG_ARM_THUMB
430 if (elf_hwcap & HWCAP_THUMB) {
431 /*
432 * The LSB of the handler determines if we're going to
433 * be using THUMB or ARM mode for this signal handler.
434 */
435 thumb = handler & 1;
436
437 if (thumb)
438 cpsr |= PSR_T_BIT;
439 else
440 cpsr &= ~PSR_T_BIT;
441 }
442#endif
443
444 if (ka->sa.sa_flags & SA_RESTORER) {
445 retcode = (unsigned long)ka->sa.sa_restorer;
446 } else {
fcca538b 447 unsigned int idx = thumb << 1;
1da177e4
LT		 448
449 if (ka->sa.sa_flags & SA_SIGINFO)
fcca538b 450 idx += 3;
1da177e4 451
fcca538b
NP		 452 if (__put_user(sigreturn_codes[idx], rc) ||
453 __put_user(sigreturn_codes[idx+1], rc+1))
1da177e4
LT		 454 return 1;
455
e00d349e
RK		 456 if (cpsr & MODE32_BIT) {
457 /*
458 * 32-bit code can use the new high-page
459 * signal return code support.
460 */
461 retcode = KERN_SIGRETURN_CODE + (idx << 2) + thumb;
462 } else {
463 /*
464 * Ensure that the instruction cache sees
465 * the return code written onto the stack.
466 */
467 flush_icache_range((unsigned long)rc,
fcca538b 468 (unsigned long)(rc + 2));
e00d349e
RK		 469
470 retcode = ((unsigned long)rc) + thumb;
471 }
1da177e4
LT		 472 }
473
474 regs->ARM_r0 = usig;
475 regs->ARM_sp = (unsigned long)frame;
476 regs->ARM_lr = retcode;
477 regs->ARM_pc = handler;
478 regs->ARM_cpsr = cpsr;
479
480 return 0;
481}
482
483static int
484setup_frame(int usig, struct k_sigaction *ka, sigset_t *set, struct pt_regs *regs)
485{
486 struct sigframe __user *frame = get_sigframe(ka, regs, sizeof(*frame));
487 int err = 0;
488
489 if (!frame)
490 return 1;
491
ca195cfe
RK		 492 /*
493 * Set uc.uc_flags to a value which sc.trap_no would never have.
494 */
495 __put_user_error(0x5ac3c35a, &frame->uc.uc_flags, err);
1da177e4 496
aca6ca10 497 err |= setup_sigframe(frame, regs, set);
1da177e4 498 if (err == 0)
fcca538b 499 err = setup_return(regs, ka, frame->retcode, frame, usig);
1da177e4
LT		 500
501 return err;
502}
503
504static int
505setup_rt_frame(int usig, struct k_sigaction *ka, siginfo_t *info,
506 sigset_t *set, struct pt_regs *regs)
507{
508 struct rt_sigframe __user *frame = get_sigframe(ka, regs, sizeof(*frame));
509 stack_t stack;
510 int err = 0;
511
512 if (!frame)
513 return 1;
514
1da177e4
LT		 515 err |= copy_siginfo_to_user(&frame->info, info);
516
cb3504e8
RK		 517 __put_user_error(0, &frame->sig.uc.uc_flags, err);
518 __put_user_error(NULL, &frame->sig.uc.uc_link, err);
1da177e4
LT		 519
520 memset(&stack, 0, sizeof(stack));
521 stack.ss_sp = (void __user *)current->sas_ss_sp;
522 stack.ss_flags = sas_ss_flags(regs->ARM_sp);
523 stack.ss_size = current->sas_ss_size;
cb3504e8 524 err |= __copy_to_user(&frame->sig.uc.uc_stack, &stack, sizeof(stack));
1da177e4 525
aca6ca10 526 err |= setup_sigframe(&frame->sig, regs, set);
1da177e4 527 if (err == 0)
cb3504e8 528 err = setup_return(regs, ka, frame->sig.retcode, frame, usig);
1da177e4
LT		 529
530 if (err == 0) {
531 /*
532 * For realtime signals we must also set the second and third
533 * arguments for the signal handler.
534 * -- Peter Maydell <pmaydell@chiark.greenend.org.uk> 2000-12-06
535 */
536 regs->ARM_r1 = (unsigned long)&frame->info;
cb3504e8 537 regs->ARM_r2 = (unsigned long)&frame->sig.uc;
1da177e4
LT		 538 }
539
540 return err;
541}
542
543static inline void restart_syscall(struct pt_regs *regs)
544{
545 regs->ARM_r0 = regs->ARM_ORIG_r0;
546 regs->ARM_pc -= thumb_mode(regs) ? 2 : 4;
547}
548
549/*
550 * OK, we're invoking a handler
551 */
552static void
553handle_signal(unsigned long sig, struct k_sigaction *ka,
554 siginfo_t *info, sigset_t *oldset,
555 struct pt_regs * regs, int syscall)
556{
557 struct thread_info *thread = current_thread_info();
558 struct task_struct *tsk = current;
559 int usig = sig;
560 int ret;
561
562 /*
563 * If we were from a system call, check for system call restarting...
564 */
565 if (syscall) {
566 switch (regs->ARM_r0) {
567 case -ERESTART_RESTARTBLOCK:
568 case -ERESTARTNOHAND:
569 regs->ARM_r0 = -EINTR;
570 break;
571 case -ERESTARTSYS:
572 if (!(ka->sa.sa_flags & SA_RESTART)) {
573 regs->ARM_r0 = -EINTR;
574 break;
575 }
576 /* fallthrough */
577 case -ERESTARTNOINTR:
578 restart_syscall(regs);
579 }
580 }
581
582 /*
583 * translate the signal
584 */
585 if (usig < 32 && thread->exec_domain && thread->exec_domain->signal_invmap)
586 usig = thread->exec_domain->signal_invmap[usig];
587
588 /*
589 * Set up the stack frame
590 */
591 if (ka->sa.sa_flags & SA_SIGINFO)
592 ret = setup_rt_frame(usig, ka, info, oldset, regs);
593 else
594 ret = setup_frame(usig, ka, oldset, regs);
595
596 /*
597 * Check that the resulting registers are actually sane.
598 */
599 ret |= !valid_user_regs(regs);
600
69be8f18 601 if (ret != 0) {
a6c61e9d
DJ		 602 force_sigsegv(sig, tsk);
603 return;
1da177e4
LT		 604 }
605
a6c61e9d
DJ		 606 /*
607 * Block the signal if we were successful.
608 */
609 spin_lock_irq(&tsk->sighand->siglock);
610 sigorsets(&tsk->blocked, &tsk->blocked,
611 &ka->sa.sa_mask);
612 if (!(ka->sa.sa_flags & SA_NODEFER))
613 sigaddset(&tsk->blocked, sig);
614 recalc_sigpending();
615 spin_unlock_irq(&tsk->sighand->siglock);
1da177e4 616
1da177e4
LT		 617}
618
619/*
620 * Note that 'init' is a special process: it doesn't get signals it doesn't
621 * want to handle. Thus you cannot kill init even with a SIGKILL even by
622 * mistake.
623 *
624 * Note that we go through the signals twice: once to check the signals that
625 * the kernel can handle, and then we build all the user-level signal handling
626 * stack-frames in one go after that.
627 */
628static int do_signal(sigset_t *oldset, struct pt_regs *regs, int syscall)
629{
630 struct k_sigaction ka;
631 siginfo_t info;
632 int signr;
633
634 /*
635 * We want the common case to go fast, which
636 * is why we may in certain cases get here from
637 * kernel mode. Just return without doing anything
638 * if so.
639 */
640 if (!user_mode(regs))
641 return 0;
642
bdb94f3a 643 if (try_to_freeze())
1da177e4
LT		 644 goto no_signal;
645
646 if (current->ptrace & PT_SINGLESTEP)
647 ptrace_cancel_bpt(current);
648
649 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
650 if (signr > 0) {
651 handle_signal(signr, &ka, &info, oldset, regs, syscall);
652 if (current->ptrace & PT_SINGLESTEP)
653 ptrace_set_bpt(current);
654 return 1;
655 }
656
657 no_signal:
658 /*
659 * No signal to deliver to the process - restart the syscall.
660 */
661 if (syscall) {
662 if (regs->ARM_r0 == -ERESTART_RESTARTBLOCK) {
663 if (thumb_mode(regs)) {
f606a6ff 664 regs->ARM_r7 = __NR_restart_syscall - __NR_SYSCALL_BASE;
1da177e4
LT		 665 regs->ARM_pc -= 2;
666 } else {
f606a6ff
NP		 667#if defined(CONFIG_AEABI) && !defined(CONFIG_OABI_COMPAT)
668 regs->ARM_r7 = __NR_restart_syscall;
669 regs->ARM_pc -= 4;
670#else
1da177e4 671 u32 __user *usp;
f606a6ff 672 u32 swival = __NR_restart_syscall;
1da177e4
LT		 673
674 regs->ARM_sp -= 12;
675 usp = (u32 __user *)regs->ARM_sp;
676
f606a6ff
NP		 677 /*
678 * Either we supports OABI only, or we have
679 * EABI with the OABI compat layer enabled.
680 * In the later case we don't know if user
681 * space is EABI or not, and if not we must
682 * not clobber r7. Always using the OABI
683 * syscall solves that issue and works for
684 * all those cases.
685 */
95eaa5fa 686 swival = swival - __NR_SYSCALL_BASE + __NR_OABI_SYSCALL_BASE;
f606a6ff 687
1da177e4
LT		 688 put_user(regs->ARM_pc, &usp[0]);
689 /* swi __NR_restart_syscall */
f606a6ff 690 put_user(0xef000000 | swival, &usp[1]);
1da177e4
LT		 691 /* ldr pc, [sp], #12 */
692 put_user(0xe49df00c, &usp[2]);
693
694 flush_icache_range((unsigned long)usp,
695 (unsigned long)(usp + 3));
696
697 regs->ARM_pc = regs->ARM_sp + 4;
f606a6ff 698#endif
1da177e4
LT		 699 }
700 }
701 if (regs->ARM_r0 == -ERESTARTNOHAND ||
702 regs->ARM_r0 == -ERESTARTSYS ||
703 regs->ARM_r0 == -ERESTARTNOINTR) {
704 restart_syscall(regs);
705 }
706 }
707 if (current->ptrace & PT_SINGLESTEP)
708 ptrace_set_bpt(current);
709 return 0;
710}
711
712asmlinkage void
713do_notify_resume(struct pt_regs *regs, unsigned int thread_flags, int syscall)
714{
715 if (thread_flags & _TIF_SIGPENDING)
716 do_signal(&current->blocked, regs, syscall);
717}
Linux kernel - Deliverables
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