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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/random.h>
12#include <linux/signal.h>
13#include <linux/personality.h>
14#include <linux/uaccess.h>
15#include <linux/tracehook.h>
16#include <linux/uprobes.h>
17
18#include <asm/elf.h>
19#include <asm/cacheflush.h>
20#include <asm/traps.h>
21#include <asm/ucontext.h>
22#include <asm/unistd.h>
23#include <asm/vfp.h>
24
25extern const unsigned long sigreturn_codes[7];
26
27static unsigned long signal_return_offset;
28
29#ifdef CONFIG_CRUNCH
30static int preserve_crunch_context(struct crunch_sigframe __user *frame)
31{
32 char kbuf[sizeof(*frame) + 8];
33 struct crunch_sigframe *kframe;
34
35 /* the crunch context must be 64 bit aligned */
36 kframe = (struct crunch_sigframe *)((unsigned long)(kbuf + 8) & ~7);
37 kframe->magic = CRUNCH_MAGIC;
38 kframe->size = CRUNCH_STORAGE_SIZE;
39 crunch_task_copy(current_thread_info(), &kframe->storage);
40 return __copy_to_user(frame, kframe, sizeof(*frame));
41}
42
43static int restore_crunch_context(struct crunch_sigframe __user *frame)
44{
45 char kbuf[sizeof(*frame) + 8];
46 struct crunch_sigframe *kframe;
47
48 /* the crunch context must be 64 bit aligned */
49 kframe = (struct crunch_sigframe *)((unsigned long)(kbuf + 8) & ~7);
50 if (__copy_from_user(kframe, frame, sizeof(*frame)))
51 return -1;
52 if (kframe->magic != CRUNCH_MAGIC ||
53 kframe->size != CRUNCH_STORAGE_SIZE)
54 return -1;
55 crunch_task_restore(current_thread_info(), &kframe->storage);
56 return 0;
57}
58#endif
59
60#ifdef CONFIG_IWMMXT
61
62static int preserve_iwmmxt_context(struct iwmmxt_sigframe *frame)
63{
64 char kbuf[sizeof(*frame) + 8];
65 struct iwmmxt_sigframe *kframe;
66
67 /* the iWMMXt context must be 64 bit aligned */
68 kframe = (struct iwmmxt_sigframe *)((unsigned long)(kbuf + 8) & ~7);
69 kframe->magic = IWMMXT_MAGIC;
70 kframe->size = IWMMXT_STORAGE_SIZE;
71 iwmmxt_task_copy(current_thread_info(), &kframe->storage);
72 return __copy_to_user(frame, kframe, sizeof(*frame));
73}
74
75static int restore_iwmmxt_context(struct iwmmxt_sigframe *frame)
76{
77 char kbuf[sizeof(*frame) + 8];
78 struct iwmmxt_sigframe *kframe;
79
80 /* the iWMMXt context must be 64 bit aligned */
81 kframe = (struct iwmmxt_sigframe *)((unsigned long)(kbuf + 8) & ~7);
82 if (__copy_from_user(kframe, frame, sizeof(*frame)))
83 return -1;
84 if (kframe->magic != IWMMXT_MAGIC ||
85 kframe->size != IWMMXT_STORAGE_SIZE)
86 return -1;
87 iwmmxt_task_restore(current_thread_info(), &kframe->storage);
88 return 0;
89}
90
91#endif
92
93#ifdef CONFIG_VFP
94
95static int preserve_vfp_context(struct vfp_sigframe __user *frame)
96{
97 const unsigned long magic = VFP_MAGIC;
98 const unsigned long size = VFP_STORAGE_SIZE;
99 int err = 0;
100
101 __put_user_error(magic, &frame->magic, err);
102 __put_user_error(size, &frame->size, err);
103
104 if (err)
105 return -EFAULT;
106
107 return vfp_preserve_user_clear_hwstate(&frame->ufp, &frame->ufp_exc);
108}
109
110static int restore_vfp_context(struct vfp_sigframe __user *frame)
111{
112 unsigned long magic;
113 unsigned long size;
114 int err = 0;
115
116 __get_user_error(magic, &frame->magic, err);
117 __get_user_error(size, &frame->size, err);
118
119 if (err)
120 return -EFAULT;
121 if (magic != VFP_MAGIC || size != VFP_STORAGE_SIZE)
122 return -EINVAL;
123
124 return vfp_restore_user_hwstate(&frame->ufp, &frame->ufp_exc);
125}
126
127#endif
128
129/*
130 * Do a signal return; undo the signal stack. These are aligned to 64-bit.
131 */
132struct sigframe {
133 struct ucontext uc;
134 unsigned long retcode[2];
135};
136
137struct rt_sigframe {
138 struct siginfo info;
139 struct sigframe sig;
140};
141
142static int restore_sigframe(struct pt_regs *regs, struct sigframe __user *sf)
143{
144 struct aux_sigframe __user *aux;
145 sigset_t set;
146 int err;
147
148 err = __copy_from_user(&set, &sf->uc.uc_sigmask, sizeof(set));
149 if (err == 0)
150 set_current_blocked(&set);
151
152 __get_user_error(regs->ARM_r0, &sf->uc.uc_mcontext.arm_r0, err);
153 __get_user_error(regs->ARM_r1, &sf->uc.uc_mcontext.arm_r1, err);
154 __get_user_error(regs->ARM_r2, &sf->uc.uc_mcontext.arm_r2, err);
155 __get_user_error(regs->ARM_r3, &sf->uc.uc_mcontext.arm_r3, err);
156 __get_user_error(regs->ARM_r4, &sf->uc.uc_mcontext.arm_r4, err);
157 __get_user_error(regs->ARM_r5, &sf->uc.uc_mcontext.arm_r5, err);
158 __get_user_error(regs->ARM_r6, &sf->uc.uc_mcontext.arm_r6, err);
159 __get_user_error(regs->ARM_r7, &sf->uc.uc_mcontext.arm_r7, err);
160 __get_user_error(regs->ARM_r8, &sf->uc.uc_mcontext.arm_r8, err);
161 __get_user_error(regs->ARM_r9, &sf->uc.uc_mcontext.arm_r9, err);
162 __get_user_error(regs->ARM_r10, &sf->uc.uc_mcontext.arm_r10, err);
163 __get_user_error(regs->ARM_fp, &sf->uc.uc_mcontext.arm_fp, err);
164 __get_user_error(regs->ARM_ip, &sf->uc.uc_mcontext.arm_ip, err);
165 __get_user_error(regs->ARM_sp, &sf->uc.uc_mcontext.arm_sp, err);
166 __get_user_error(regs->ARM_lr, &sf->uc.uc_mcontext.arm_lr, err);
167 __get_user_error(regs->ARM_pc, &sf->uc.uc_mcontext.arm_pc, err);
168 __get_user_error(regs->ARM_cpsr, &sf->uc.uc_mcontext.arm_cpsr, err);
169
170 err |= !valid_user_regs(regs);
171
172 aux = (struct aux_sigframe __user *) sf->uc.uc_regspace;
173#ifdef CONFIG_CRUNCH
174 if (err == 0)
175 err |= restore_crunch_context(&aux->crunch);
176#endif
177#ifdef CONFIG_IWMMXT
178 if (err == 0 && test_thread_flag(TIF_USING_IWMMXT))
179 err |= restore_iwmmxt_context(&aux->iwmmxt);
180#endif
181#ifdef CONFIG_VFP
182 if (err == 0)
183 err |= restore_vfp_context(&aux->vfp);
184#endif
185
186 return err;
187}
188
189asmlinkage int sys_sigreturn(struct pt_regs *regs)
190{
191 struct sigframe __user *frame;
192
193 /* Always make any pending restarted system calls return -EINTR */
194 current->restart_block.fn = do_no_restart_syscall;
195
196 /*
197 * Since we stacked the signal on a 64-bit boundary,
198 * then 'sp' should be word aligned here. If it's
199 * not, then the user is trying to mess with us.
200 */
201 if (regs->ARM_sp & 7)
202 goto badframe;
203
204 frame = (struct sigframe __user *)regs->ARM_sp;
205
206 if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
207 goto badframe;
208
209 if (restore_sigframe(regs, frame))
210 goto badframe;
211
212 return regs->ARM_r0;
213
214badframe:
215 force_sig(SIGSEGV, current);
216 return 0;
217}
218
219asmlinkage int sys_rt_sigreturn(struct pt_regs *regs)
220{
221 struct rt_sigframe __user *frame;
222
223 /* Always make any pending restarted system calls return -EINTR */
224 current->restart_block.fn = do_no_restart_syscall;
225
226 /*
227 * Since we stacked the signal on a 64-bit boundary,
228 * then 'sp' should be word aligned here. If it's
229 * not, then the user is trying to mess with us.
230 */
231 if (regs->ARM_sp & 7)
232 goto badframe;
233
234 frame = (struct rt_sigframe __user *)regs->ARM_sp;
235
236 if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
237 goto badframe;
238
239 if (restore_sigframe(regs, &frame->sig))
240 goto badframe;
241
242 if (restore_altstack(&frame->sig.uc.uc_stack))
243 goto badframe;
244
245 return regs->ARM_r0;
246
247badframe:
248 force_sig(SIGSEGV, current);
249 return 0;
250}
251
252static int
253setup_sigframe(struct sigframe __user *sf, struct pt_regs *regs, sigset_t *set)
254{
255 struct aux_sigframe __user *aux;
256 int err = 0;
257
258 __put_user_error(regs->ARM_r0, &sf->uc.uc_mcontext.arm_r0, err);
259 __put_user_error(regs->ARM_r1, &sf->uc.uc_mcontext.arm_r1, err);
260 __put_user_error(regs->ARM_r2, &sf->uc.uc_mcontext.arm_r2, err);
261 __put_user_error(regs->ARM_r3, &sf->uc.uc_mcontext.arm_r3, err);
262 __put_user_error(regs->ARM_r4, &sf->uc.uc_mcontext.arm_r4, err);
263 __put_user_error(regs->ARM_r5, &sf->uc.uc_mcontext.arm_r5, err);
264 __put_user_error(regs->ARM_r6, &sf->uc.uc_mcontext.arm_r6, err);
265 __put_user_error(regs->ARM_r7, &sf->uc.uc_mcontext.arm_r7, err);
266 __put_user_error(regs->ARM_r8, &sf->uc.uc_mcontext.arm_r8, err);
267 __put_user_error(regs->ARM_r9, &sf->uc.uc_mcontext.arm_r9, err);
268 __put_user_error(regs->ARM_r10, &sf->uc.uc_mcontext.arm_r10, err);
269 __put_user_error(regs->ARM_fp, &sf->uc.uc_mcontext.arm_fp, err);
270 __put_user_error(regs->ARM_ip, &sf->uc.uc_mcontext.arm_ip, err);
271 __put_user_error(regs->ARM_sp, &sf->uc.uc_mcontext.arm_sp, err);
272 __put_user_error(regs->ARM_lr, &sf->uc.uc_mcontext.arm_lr, err);
273 __put_user_error(regs->ARM_pc, &sf->uc.uc_mcontext.arm_pc, err);
274 __put_user_error(regs->ARM_cpsr, &sf->uc.uc_mcontext.arm_cpsr, err);
275
276 __put_user_error(current->thread.trap_no, &sf->uc.uc_mcontext.trap_no, err);
277 __put_user_error(current->thread.error_code, &sf->uc.uc_mcontext.error_code, err);
278 __put_user_error(current->thread.address, &sf->uc.uc_mcontext.fault_address, err);
279 __put_user_error(set->sig[0], &sf->uc.uc_mcontext.oldmask, err);
280
281 err |= __copy_to_user(&sf->uc.uc_sigmask, set, sizeof(*set));
282
283 aux = (struct aux_sigframe __user *) sf->uc.uc_regspace;
284#ifdef CONFIG_CRUNCH
285 if (err == 0)
286 err |= preserve_crunch_context(&aux->crunch);
287#endif
288#ifdef CONFIG_IWMMXT
289 if (err == 0 && test_thread_flag(TIF_USING_IWMMXT))
290 err |= preserve_iwmmxt_context(&aux->iwmmxt);
291#endif
292#ifdef CONFIG_VFP
293 if (err == 0)
294 err |= preserve_vfp_context(&aux->vfp);
295#endif
296 __put_user_error(0, &aux->end_magic, err);
297
298 return err;
299}
300
301static inline void __user *
302get_sigframe(struct ksignal *ksig, struct pt_regs *regs, int framesize)
303{
304 unsigned long sp = sigsp(regs->ARM_sp, ksig);
305 void __user *frame;
306
307 /*
308 * ATPCS B01 mandates 8-byte alignment
309 */
310 frame = (void __user *)((sp - framesize) & ~7);
311
312 /*
313 * Check that we can actually write to the signal frame.
314 */
315 if (!access_ok(VERIFY_WRITE, frame, framesize))
316 frame = NULL;
317
318 return frame;
319}
320
321static int
322setup_return(struct pt_regs *regs, struct ksignal *ksig,
323 unsigned long __user *rc, void __user *frame)
324{
325 unsigned long handler = (unsigned long)ksig->ka.sa.sa_handler;
326 unsigned long retcode;
327 int thumb = 0;
328 unsigned long cpsr = regs->ARM_cpsr & ~(PSR_f | PSR_E_BIT);
329
330 cpsr |= PSR_ENDSTATE;
331
332 /*
333 * Maybe we need to deliver a 32-bit signal to a 26-bit task.
334 */
335 if (ksig->ka.sa.sa_flags & SA_THIRTYTWO)
336 cpsr = (cpsr & ~MODE_MASK) | USR_MODE;
337
338#ifdef CONFIG_ARM_THUMB
339 if (elf_hwcap & HWCAP_THUMB) {
340 /*
341 * The LSB of the handler determines if we're going to
342 * be using THUMB or ARM mode for this signal handler.
343 */
344 thumb = handler & 1;
345
346 /*
347 * Clear the If-Then Thumb-2 execution state. ARM spec
348 * requires this to be all 000s in ARM mode. Snapdragon
349 * S4/Krait misbehaves on a Thumb=>ARM signal transition
350 * without this.
351 *
352 * We must do this whenever we are running on a Thumb-2
353 * capable CPU, which includes ARMv6T2. However, we elect
354 * to always do this to simplify the code; this field is
355 * marked UNK/SBZP for older architectures.
356 */
357 cpsr &= ~PSR_IT_MASK;
358
359 if (thumb) {
360 cpsr |= PSR_T_BIT;
361 } else
362 cpsr &= ~PSR_T_BIT;
363 }
364#endif
365
366 if (ksig->ka.sa.sa_flags & SA_RESTORER) {
367 retcode = (unsigned long)ksig->ka.sa.sa_restorer;
368 } else {
369 unsigned int idx = thumb << 1;
370
371 if (ksig->ka.sa.sa_flags & SA_SIGINFO)
372 idx += 3;
373
374 /*
375 * Put the sigreturn code on the stack no matter which return
376 * mechanism we use in order to remain ABI compliant
377 */
378 if (__put_user(sigreturn_codes[idx], rc) ||
379 __put_user(sigreturn_codes[idx+1], rc+1))
380 return 1;
381
382#ifdef CONFIG_MMU
383 if (cpsr & MODE32_BIT) {
384 struct mm_struct *mm = current->mm;
385
386 /*
387 * 32-bit code can use the signal return page
388 * except when the MPU has protected the vectors
389 * page from PL0
390 */
391 retcode = mm->context.sigpage + signal_return_offset +
392 (idx << 2) + thumb;
393 } else
394#endif
395 {
396 /*
397 * Ensure that the instruction cache sees
398 * the return code written onto the stack.
399 */
400 flush_icache_range((unsigned long)rc,
401 (unsigned long)(rc + 2));
402
403 retcode = ((unsigned long)rc) + thumb;
404 }
405 }
406
407 regs->ARM_r0 = ksig->sig;
408 regs->ARM_sp = (unsigned long)frame;
409 regs->ARM_lr = retcode;
410 regs->ARM_pc = handler;
411 regs->ARM_cpsr = cpsr;
412
413 return 0;
414}
415
416static int
417setup_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs)
418{
419 struct sigframe __user *frame = get_sigframe(ksig, regs, sizeof(*frame));
420 int err = 0;
421
422 if (!frame)
423 return 1;
424
425 /*
426 * Set uc.uc_flags to a value which sc.trap_no would never have.
427 */
428 __put_user_error(0x5ac3c35a, &frame->uc.uc_flags, err);
429
430 err |= setup_sigframe(frame, regs, set);
431 if (err == 0)
432 err = setup_return(regs, ksig, frame->retcode, frame);
433
434 return err;
435}
436
437static int
438setup_rt_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs)
439{
440 struct rt_sigframe __user *frame = get_sigframe(ksig, regs, sizeof(*frame));
441 int err = 0;
442
443 if (!frame)
444 return 1;
445
446 err |= copy_siginfo_to_user(&frame->info, &ksig->info);
447
448 __put_user_error(0, &frame->sig.uc.uc_flags, err);
449 __put_user_error(NULL, &frame->sig.uc.uc_link, err);
450
451 err |= __save_altstack(&frame->sig.uc.uc_stack, regs->ARM_sp);
452 err |= setup_sigframe(&frame->sig, regs, set);
453 if (err == 0)
454 err = setup_return(regs, ksig, frame->sig.retcode, frame);
455
456 if (err == 0) {
457 /*
458 * For realtime signals we must also set the second and third
459 * arguments for the signal handler.
460 * -- Peter Maydell <pmaydell@chiark.greenend.org.uk> 2000-12-06
461 */
462 regs->ARM_r1 = (unsigned long)&frame->info;
463 regs->ARM_r2 = (unsigned long)&frame->sig.uc;
464 }
465
466 return err;
467}
468
469/*
470 * OK, we're invoking a handler
471 */
472static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
473{
474 sigset_t *oldset = sigmask_to_save();
475 int ret;
476
477 /*
478 * Set up the stack frame
479 */
480 if (ksig->ka.sa.sa_flags & SA_SIGINFO)
481 ret = setup_rt_frame(ksig, oldset, regs);
482 else
483 ret = setup_frame(ksig, oldset, regs);
484
485 /*
486 * Check that the resulting registers are actually sane.
487 */
488 ret |= !valid_user_regs(regs);
489
490 signal_setup_done(ret, ksig, 0);
491}
492
493/*
494 * Note that 'init' is a special process: it doesn't get signals it doesn't
495 * want to handle. Thus you cannot kill init even with a SIGKILL even by
496 * mistake.
497 *
498 * Note that we go through the signals twice: once to check the signals that
499 * the kernel can handle, and then we build all the user-level signal handling
500 * stack-frames in one go after that.
501 */
502static int do_signal(struct pt_regs *regs, int syscall)
503{
504 unsigned int retval = 0, continue_addr = 0, restart_addr = 0;
505 struct ksignal ksig;
506 int restart = 0;
507
508 /*
509 * If we were from a system call, check for system call restarting...
510 */
511 if (syscall) {
512 continue_addr = regs->ARM_pc;
513 restart_addr = continue_addr - (thumb_mode(regs) ? 2 : 4);
514 retval = regs->ARM_r0;
515
516 /*
517 * Prepare for system call restart. We do this here so that a
518 * debugger will see the already changed PSW.
519 */
520 switch (retval) {
521 case -ERESTART_RESTARTBLOCK:
522 restart -= 2;
523 case -ERESTARTNOHAND:
524 case -ERESTARTSYS:
525 case -ERESTARTNOINTR:
526 restart++;
527 regs->ARM_r0 = regs->ARM_ORIG_r0;
528 regs->ARM_pc = restart_addr;
529 break;
530 }
531 }
532
533 /*
534 * Get the signal to deliver. When running under ptrace, at this
535 * point the debugger may change all our registers ...
536 */
537 /*
538 * Depending on the signal settings we may need to revert the
539 * decision to restart the system call. But skip this if a
540 * debugger has chosen to restart at a different PC.
541 */
542 if (get_signal(&ksig)) {
543 /* handler */
544 if (unlikely(restart) && regs->ARM_pc == restart_addr) {
545 if (retval == -ERESTARTNOHAND ||
546 retval == -ERESTART_RESTARTBLOCK
547 || (retval == -ERESTARTSYS
548 && !(ksig.ka.sa.sa_flags & SA_RESTART))) {
549 regs->ARM_r0 = -EINTR;
550 regs->ARM_pc = continue_addr;
551 }
552 }
553 handle_signal(&ksig, regs);
554 } else {
555 /* no handler */
556 restore_saved_sigmask();
557 if (unlikely(restart) && regs->ARM_pc == restart_addr) {
558 regs->ARM_pc = continue_addr;
559 return restart;
560 }
561 }
562 return 0;
563}
564
565asmlinkage int
566do_work_pending(struct pt_regs *regs, unsigned int thread_flags, int syscall)
567{
568 /*
569 * The assembly code enters us with IRQs off, but it hasn't
570 * informed the tracing code of that for efficiency reasons.
571 * Update the trace code with the current status.
572 */
573 trace_hardirqs_off();
574 do {
575 if (likely(thread_flags & _TIF_NEED_RESCHED)) {
576 schedule();
577 } else {
578 if (unlikely(!user_mode(regs)))
579 return 0;
580 local_irq_enable();
581 if (thread_flags & _TIF_SIGPENDING) {
582 int restart = do_signal(regs, syscall);
583 if (unlikely(restart)) {
584 /*
585 * Restart without handlers.
586 * Deal with it without leaving
587 * the kernel space.
588 */
589 return restart;
590 }
591 syscall = 0;
592 } else if (thread_flags & _TIF_UPROBE) {
593 uprobe_notify_resume(regs);
594 } else {
595 clear_thread_flag(TIF_NOTIFY_RESUME);
596 tracehook_notify_resume(regs);
597 }
598 }
599 local_irq_disable();
600 thread_flags = current_thread_info()->flags;
601 } while (thread_flags & _TIF_WORK_MASK);
602 return 0;
603}
604
605struct page *get_signal_page(void)
606{
607 unsigned long ptr;
608 unsigned offset;
609 struct page *page;
610 void *addr;
611
612 page = alloc_pages(GFP_KERNEL, 0);
613
614 if (!page)
615 return NULL;
616
617 addr = page_address(page);
618
619 /* Give the signal return code some randomness */
620 offset = 0x200 + (get_random_int() & 0x7fc);
621 signal_return_offset = offset;
622
623 /*
624 * Copy signal return handlers into the vector page, and
625 * set sigreturn to be a pointer to these.
626 */
627 memcpy(addr + offset, sigreturn_codes, sizeof(sigreturn_codes));
628
629 ptr = (unsigned long)addr + offset;
630 flush_icache_range(ptr, ptr + sizeof(sigreturn_codes));
631
632 return page;
633}
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
47const 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 */
59const 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 */
67asmlinkage int sys_sigsuspend(int restart, unsigned long oldmask, old_sigset_t mask)
68{
69 mask &= _BLOCKABLE;
70 spin_lock_irq(¤t->sighand->siglock);
71 current->saved_sigmask = current->blocked;
72 siginitset(¤t->blocked, mask);
73 recalc_sigpending();
74 spin_unlock_irq(¤t->sighand->siglock);
75
76 current->state = TASK_INTERRUPTIBLE;
77 schedule();
78 set_restore_sigmask();
79 return -ERESTARTNOHAND;
80}
81
82asmlinkage int
83sys_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
115static 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
128static 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
147static 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
160static 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
180static 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
213static 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 */
265struct sigframe {
266 struct ucontext uc;
267 unsigned long retcode[2];
268};
269
270struct rt_sigframe {
271 struct siginfo info;
272 struct sigframe sig;
273};
274
275static 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(¤t->sighand->siglock);
285 current->blocked = set;
286 recalc_sigpending();
287 spin_unlock_irq(¤t->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
327asmlinkage 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
352badframe:
353 force_sig(SIGSEGV, current);
354 return 0;
355}
356
357asmlinkage 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
385badframe:
386 force_sig(SIGSEGV, current);
387 return 0;
388}
389
390static int
391setup_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
439static inline void __user *
440get_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
465static int
466setup_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
540static int
541setup_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
561static int
562setup_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 */
603static int
604handle_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 */
660static 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 = ¤t->saved_sigmask;
728 else
729 oldset = ¤t->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, ¤t->saved_sigmask, NULL);
781 }
782 }
783}
784
785asmlinkage void
786do_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}