2 * linux/arch/arm/kernel/signal.c
4 * Copyright (C) 1995-2002 Russell King
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.
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>
18 #include <asm/cacheflush.h>
19 #include <asm/ucontext.h>
20 #include <asm/unistd.h>
25 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
28 * For ARM syscalls, we encode the syscall number into the instruction.
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))
34 * With EABI, the syscall number has to be loaded into r7.
36 #define MOV_R7_NR_SIGRETURN (0xe3a07000 | (__NR_sigreturn - __NR_SYSCALL_BASE))
37 #define MOV_R7_NR_RT_SIGRETURN (0xe3a07000 | (__NR_rt_sigreturn - __NR_SYSCALL_BASE))
40 * For Thumb syscalls, we pass the syscall number via r7. We therefore
41 * need two 16-bit instructions.
43 #define SWI_THUMB_SIGRETURN (0xdf00 << 16 | 0x2700 | (__NR_sigreturn - __NR_SYSCALL_BASE))
44 #define SWI_THUMB_RT_SIGRETURN (0xdf00 << 16 | 0x2700 | (__NR_rt_sigreturn - __NR_SYSCALL_BASE))
46 const unsigned long sigreturn_codes[7] = {
47 MOV_R7_NR_SIGRETURN, SWI_SYS_SIGRETURN, SWI_THUMB_SIGRETURN,
48 MOV_R7_NR_RT_SIGRETURN, SWI_SYS_RT_SIGRETURN, SWI_THUMB_RT_SIGRETURN,
51 static int do_signal(sigset_t *oldset, struct pt_regs * regs, int syscall);
54 * atomically swap in the new signal mask, and wait for a signal.
56 asmlinkage int sys_sigsuspend(int restart, unsigned long oldmask, old_sigset_t mask, struct pt_regs *regs)
61 spin_lock_irq(¤t->sighand->siglock);
62 saveset = current->blocked;
63 siginitset(¤t->blocked, mask);
65 spin_unlock_irq(¤t->sighand->siglock);
66 regs->ARM_r0 = -EINTR;
69 current->state = TASK_INTERRUPTIBLE;
71 if (do_signal(&saveset, regs, 0))
77 sys_rt_sigsuspend(sigset_t __user *unewset, size_t sigsetsize, struct pt_regs *regs)
79 sigset_t saveset, newset;
81 /* XXX: Don't preclude handling different sized sigset_t's. */
82 if (sigsetsize != sizeof(sigset_t))
85 if (copy_from_user(&newset, unewset, sizeof(newset)))
87 sigdelsetmask(&newset, ~_BLOCKABLE);
89 spin_lock_irq(¤t->sighand->siglock);
90 saveset = current->blocked;
91 current->blocked = newset;
93 spin_unlock_irq(¤t->sighand->siglock);
94 regs->ARM_r0 = -EINTR;
97 current->state = TASK_INTERRUPTIBLE;
99 if (do_signal(&saveset, regs, 0))
105 sys_sigaction(int sig, const struct old_sigaction __user *act,
106 struct old_sigaction __user *oact)
108 struct k_sigaction new_ka, old_ka;
113 if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
114 __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
115 __get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
117 __get_user(new_ka.sa.sa_flags, &act->sa_flags);
118 __get_user(mask, &act->sa_mask);
119 siginitset(&new_ka.sa.sa_mask, mask);
122 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
125 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
126 __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
127 __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
129 __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
130 __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
137 static int preserve_crunch_context(struct crunch_sigframe __user *frame)
139 char kbuf[sizeof(*frame) + 8];
140 struct crunch_sigframe *kframe;
142 /* the crunch context must be 64 bit aligned */
143 kframe = (struct crunch_sigframe *)((unsigned long)(kbuf + 8) & ~7);
144 kframe->magic = CRUNCH_MAGIC;
145 kframe->size = CRUNCH_STORAGE_SIZE;
146 crunch_task_copy(current_thread_info(), &kframe->storage);
147 return __copy_to_user(frame, kframe, sizeof(*frame));
150 static int restore_crunch_context(struct crunch_sigframe __user *frame)
152 char kbuf[sizeof(*frame) + 8];
153 struct crunch_sigframe *kframe;
155 /* the crunch context must be 64 bit aligned */
156 kframe = (struct crunch_sigframe *)((unsigned long)(kbuf + 8) & ~7);
157 if (__copy_from_user(kframe, frame, sizeof(*frame)))
159 if (kframe->magic != CRUNCH_MAGIC ||
160 kframe->size != CRUNCH_STORAGE_SIZE)
162 crunch_task_restore(current_thread_info(), &kframe->storage);
169 static int preserve_iwmmxt_context(struct iwmmxt_sigframe *frame)
171 char kbuf[sizeof(*frame) + 8];
172 struct iwmmxt_sigframe *kframe;
174 /* the iWMMXt context must be 64 bit aligned */
175 kframe = (struct iwmmxt_sigframe *)((unsigned long)(kbuf + 8) & ~7);
176 kframe->magic = IWMMXT_MAGIC;
177 kframe->size = IWMMXT_STORAGE_SIZE;
178 iwmmxt_task_copy(current_thread_info(), &kframe->storage);
179 return __copy_to_user(frame, kframe, sizeof(*frame));
182 static int restore_iwmmxt_context(struct iwmmxt_sigframe *frame)
184 char kbuf[sizeof(*frame) + 8];
185 struct iwmmxt_sigframe *kframe;
187 /* the iWMMXt context must be 64 bit aligned */
188 kframe = (struct iwmmxt_sigframe *)((unsigned long)(kbuf + 8) & ~7);
189 if (__copy_from_user(kframe, frame, sizeof(*frame)))
191 if (kframe->magic != IWMMXT_MAGIC ||
192 kframe->size != IWMMXT_STORAGE_SIZE)
194 iwmmxt_task_restore(current_thread_info(), &kframe->storage);
201 * Do a signal return; undo the signal stack. These are aligned to 64-bit.
205 unsigned long retcode[2];
213 static int restore_sigframe(struct pt_regs *regs, struct sigframe __user *sf)
215 struct aux_sigframe __user *aux;
219 err = __copy_from_user(&set, &sf->uc.uc_sigmask, sizeof(set));
221 sigdelsetmask(&set, ~_BLOCKABLE);
222 spin_lock_irq(¤t->sighand->siglock);
223 current->blocked = set;
225 spin_unlock_irq(¤t->sighand->siglock);
228 __get_user_error(regs->ARM_r0, &sf->uc.uc_mcontext.arm_r0, err);
229 __get_user_error(regs->ARM_r1, &sf->uc.uc_mcontext.arm_r1, err);
230 __get_user_error(regs->ARM_r2, &sf->uc.uc_mcontext.arm_r2, err);
231 __get_user_error(regs->ARM_r3, &sf->uc.uc_mcontext.arm_r3, err);
232 __get_user_error(regs->ARM_r4, &sf->uc.uc_mcontext.arm_r4, err);
233 __get_user_error(regs->ARM_r5, &sf->uc.uc_mcontext.arm_r5, err);
234 __get_user_error(regs->ARM_r6, &sf->uc.uc_mcontext.arm_r6, err);
235 __get_user_error(regs->ARM_r7, &sf->uc.uc_mcontext.arm_r7, err);
236 __get_user_error(regs->ARM_r8, &sf->uc.uc_mcontext.arm_r8, err);
237 __get_user_error(regs->ARM_r9, &sf->uc.uc_mcontext.arm_r9, err);
238 __get_user_error(regs->ARM_r10, &sf->uc.uc_mcontext.arm_r10, err);
239 __get_user_error(regs->ARM_fp, &sf->uc.uc_mcontext.arm_fp, err);
240 __get_user_error(regs->ARM_ip, &sf->uc.uc_mcontext.arm_ip, err);
241 __get_user_error(regs->ARM_sp, &sf->uc.uc_mcontext.arm_sp, err);
242 __get_user_error(regs->ARM_lr, &sf->uc.uc_mcontext.arm_lr, err);
243 __get_user_error(regs->ARM_pc, &sf->uc.uc_mcontext.arm_pc, err);
244 __get_user_error(regs->ARM_cpsr, &sf->uc.uc_mcontext.arm_cpsr, err);
246 err |= !valid_user_regs(regs);
248 aux = (struct aux_sigframe __user *) sf->uc.uc_regspace;
251 err |= restore_crunch_context(&aux->crunch);
254 if (err == 0 && test_thread_flag(TIF_USING_IWMMXT))
255 err |= restore_iwmmxt_context(&aux->iwmmxt);
259 // err |= vfp_restore_state(&sf->aux.vfp);
265 asmlinkage int sys_sigreturn(struct pt_regs *regs)
267 struct sigframe __user *frame;
269 /* Always make any pending restarted system calls return -EINTR */
270 current_thread_info()->restart_block.fn = do_no_restart_syscall;
273 * Since we stacked the signal on a 64-bit boundary,
274 * then 'sp' should be word aligned here. If it's
275 * not, then the user is trying to mess with us.
277 if (regs->ARM_sp & 7)
280 frame = (struct sigframe __user *)regs->ARM_sp;
282 if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
285 if (restore_sigframe(regs, frame))
288 single_step_trap(current);
293 force_sig(SIGSEGV, current);
297 asmlinkage int sys_rt_sigreturn(struct pt_regs *regs)
299 struct rt_sigframe __user *frame;
301 /* Always make any pending restarted system calls return -EINTR */
302 current_thread_info()->restart_block.fn = do_no_restart_syscall;
305 * Since we stacked the signal on a 64-bit boundary,
306 * then 'sp' should be word aligned here. If it's
307 * not, then the user is trying to mess with us.
309 if (regs->ARM_sp & 7)
312 frame = (struct rt_sigframe __user *)regs->ARM_sp;
314 if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
317 if (restore_sigframe(regs, &frame->sig))
320 if (do_sigaltstack(&frame->sig.uc.uc_stack, NULL, regs->ARM_sp) == -EFAULT)
323 single_step_trap(current);
328 force_sig(SIGSEGV, current);
333 setup_sigframe(struct sigframe __user *sf, struct pt_regs *regs, sigset_t *set)
335 struct aux_sigframe __user *aux;
338 __put_user_error(regs->ARM_r0, &sf->uc.uc_mcontext.arm_r0, err);
339 __put_user_error(regs->ARM_r1, &sf->uc.uc_mcontext.arm_r1, err);
340 __put_user_error(regs->ARM_r2, &sf->uc.uc_mcontext.arm_r2, err);
341 __put_user_error(regs->ARM_r3, &sf->uc.uc_mcontext.arm_r3, err);
342 __put_user_error(regs->ARM_r4, &sf->uc.uc_mcontext.arm_r4, err);
343 __put_user_error(regs->ARM_r5, &sf->uc.uc_mcontext.arm_r5, err);
344 __put_user_error(regs->ARM_r6, &sf->uc.uc_mcontext.arm_r6, err);
345 __put_user_error(regs->ARM_r7, &sf->uc.uc_mcontext.arm_r7, err);
346 __put_user_error(regs->ARM_r8, &sf->uc.uc_mcontext.arm_r8, err);
347 __put_user_error(regs->ARM_r9, &sf->uc.uc_mcontext.arm_r9, err);
348 __put_user_error(regs->ARM_r10, &sf->uc.uc_mcontext.arm_r10, err);
349 __put_user_error(regs->ARM_fp, &sf->uc.uc_mcontext.arm_fp, err);
350 __put_user_error(regs->ARM_ip, &sf->uc.uc_mcontext.arm_ip, err);
351 __put_user_error(regs->ARM_sp, &sf->uc.uc_mcontext.arm_sp, err);
352 __put_user_error(regs->ARM_lr, &sf->uc.uc_mcontext.arm_lr, err);
353 __put_user_error(regs->ARM_pc, &sf->uc.uc_mcontext.arm_pc, err);
354 __put_user_error(regs->ARM_cpsr, &sf->uc.uc_mcontext.arm_cpsr, err);
356 __put_user_error(current->thread.trap_no, &sf->uc.uc_mcontext.trap_no, err);
357 __put_user_error(current->thread.error_code, &sf->uc.uc_mcontext.error_code, err);
358 __put_user_error(current->thread.address, &sf->uc.uc_mcontext.fault_address, err);
359 __put_user_error(set->sig[0], &sf->uc.uc_mcontext.oldmask, err);
361 err |= __copy_to_user(&sf->uc.uc_sigmask, set, sizeof(*set));
363 aux = (struct aux_sigframe __user *) sf->uc.uc_regspace;
366 err |= preserve_crunch_context(&aux->crunch);
369 if (err == 0 && test_thread_flag(TIF_USING_IWMMXT))
370 err |= preserve_iwmmxt_context(&aux->iwmmxt);
374 // err |= vfp_save_state(&sf->aux.vfp);
376 __put_user_error(0, &aux->end_magic, err);
381 static inline void __user *
382 get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, int framesize)
384 unsigned long sp = regs->ARM_sp;
388 * This is the X/Open sanctioned signal stack switching.
390 if ((ka->sa.sa_flags & SA_ONSTACK) && !sas_ss_flags(sp))
391 sp = current->sas_ss_sp + current->sas_ss_size;
394 * ATPCS B01 mandates 8-byte alignment
396 frame = (void __user *)((sp - framesize) & ~7);
399 * Check that we can actually write to the signal frame.
401 if (!access_ok(VERIFY_WRITE, frame, framesize))
408 setup_return(struct pt_regs *regs, struct k_sigaction *ka,
409 unsigned long __user *rc, void __user *frame, int usig)
411 unsigned long handler = (unsigned long)ka->sa.sa_handler;
412 unsigned long retcode;
414 unsigned long cpsr = regs->ARM_cpsr & ~PSR_f;
417 * Maybe we need to deliver a 32-bit signal to a 26-bit task.
419 if (ka->sa.sa_flags & SA_THIRTYTWO)
420 cpsr = (cpsr & ~MODE_MASK) | USR_MODE;
422 #ifdef CONFIG_ARM_THUMB
423 if (elf_hwcap & HWCAP_THUMB) {
425 * The LSB of the handler determines if we're going to
426 * be using THUMB or ARM mode for this signal handler.
432 #if __LINUX_ARM_ARCH__ >= 7
433 /* clear the If-Then Thumb-2 execution state */
434 cpsr &= ~PSR_IT_MASK;
441 if (ka->sa.sa_flags & SA_RESTORER) {
442 retcode = (unsigned long)ka->sa.sa_restorer;
444 unsigned int idx = thumb << 1;
446 if (ka->sa.sa_flags & SA_SIGINFO)
449 if (__put_user(sigreturn_codes[idx], rc) ||
450 __put_user(sigreturn_codes[idx+1], rc+1))
453 if (cpsr & MODE32_BIT) {
455 * 32-bit code can use the new high-page
456 * signal return code support.
458 retcode = KERN_SIGRETURN_CODE + (idx << 2) + thumb;
461 * Ensure that the instruction cache sees
462 * the return code written onto the stack.
464 flush_icache_range((unsigned long)rc,
465 (unsigned long)(rc + 2));
467 retcode = ((unsigned long)rc) + thumb;
472 regs->ARM_sp = (unsigned long)frame;
473 regs->ARM_lr = retcode;
474 regs->ARM_pc = handler;
475 regs->ARM_cpsr = cpsr;
481 setup_frame(int usig, struct k_sigaction *ka, sigset_t *set, struct pt_regs *regs)
483 struct sigframe __user *frame = get_sigframe(ka, regs, sizeof(*frame));
490 * Set uc.uc_flags to a value which sc.trap_no would never have.
492 __put_user_error(0x5ac3c35a, &frame->uc.uc_flags, err);
494 err |= setup_sigframe(frame, regs, set);
496 err = setup_return(regs, ka, frame->retcode, frame, usig);
502 setup_rt_frame(int usig, struct k_sigaction *ka, siginfo_t *info,
503 sigset_t *set, struct pt_regs *regs)
505 struct rt_sigframe __user *frame = get_sigframe(ka, regs, sizeof(*frame));
512 err |= copy_siginfo_to_user(&frame->info, info);
514 __put_user_error(0, &frame->sig.uc.uc_flags, err);
515 __put_user_error(NULL, &frame->sig.uc.uc_link, err);
517 memset(&stack, 0, sizeof(stack));
518 stack.ss_sp = (void __user *)current->sas_ss_sp;
519 stack.ss_flags = sas_ss_flags(regs->ARM_sp);
520 stack.ss_size = current->sas_ss_size;
521 err |= __copy_to_user(&frame->sig.uc.uc_stack, &stack, sizeof(stack));
523 err |= setup_sigframe(&frame->sig, regs, set);
525 err = setup_return(regs, ka, frame->sig.retcode, frame, usig);
529 * For realtime signals we must also set the second and third
530 * arguments for the signal handler.
531 * -- Peter Maydell <pmaydell@chiark.greenend.org.uk> 2000-12-06
533 regs->ARM_r1 = (unsigned long)&frame->info;
534 regs->ARM_r2 = (unsigned long)&frame->sig.uc;
540 static inline void setup_syscall_restart(struct pt_regs *regs)
542 regs->ARM_r0 = regs->ARM_ORIG_r0;
543 regs->ARM_pc -= thumb_mode(regs) ? 2 : 4;
547 * OK, we're invoking a handler
550 handle_signal(unsigned long sig, struct k_sigaction *ka,
551 siginfo_t *info, sigset_t *oldset,
552 struct pt_regs * regs, int syscall)
554 struct thread_info *thread = current_thread_info();
555 struct task_struct *tsk = current;
560 * If we were from a system call, check for system call restarting...
563 switch (regs->ARM_r0) {
564 case -ERESTART_RESTARTBLOCK:
565 case -ERESTARTNOHAND:
566 regs->ARM_r0 = -EINTR;
569 if (!(ka->sa.sa_flags & SA_RESTART)) {
570 regs->ARM_r0 = -EINTR;
574 case -ERESTARTNOINTR:
575 setup_syscall_restart(regs);
580 * translate the signal
582 if (usig < 32 && thread->exec_domain && thread->exec_domain->signal_invmap)
583 usig = thread->exec_domain->signal_invmap[usig];
586 * Set up the stack frame
588 if (ka->sa.sa_flags & SA_SIGINFO)
589 ret = setup_rt_frame(usig, ka, info, oldset, regs);
591 ret = setup_frame(usig, ka, oldset, regs);
594 * Check that the resulting registers are actually sane.
596 ret |= !valid_user_regs(regs);
599 force_sigsegv(sig, tsk);
604 * Block the signal if we were successful.
606 spin_lock_irq(&tsk->sighand->siglock);
607 sigorsets(&tsk->blocked, &tsk->blocked,
609 if (!(ka->sa.sa_flags & SA_NODEFER))
610 sigaddset(&tsk->blocked, sig);
612 spin_unlock_irq(&tsk->sighand->siglock);
617 * Note that 'init' is a special process: it doesn't get signals it doesn't
618 * want to handle. Thus you cannot kill init even with a SIGKILL even by
621 * Note that we go through the signals twice: once to check the signals that
622 * the kernel can handle, and then we build all the user-level signal handling
623 * stack-frames in one go after that.
625 static int do_signal(sigset_t *oldset, struct pt_regs *regs, int syscall)
627 struct k_sigaction ka;
632 * We want the common case to go fast, which
633 * is why we may in certain cases get here from
634 * kernel mode. Just return without doing anything
637 if (!user_mode(regs))
643 single_step_clear(current);
645 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
647 handle_signal(signr, &ka, &info, oldset, regs, syscall);
648 single_step_set(current);
654 * No signal to deliver to the process - restart the syscall.
657 if (regs->ARM_r0 == -ERESTART_RESTARTBLOCK) {
658 if (thumb_mode(regs)) {
659 regs->ARM_r7 = __NR_restart_syscall - __NR_SYSCALL_BASE;
662 #if defined(CONFIG_AEABI) && !defined(CONFIG_OABI_COMPAT)
663 regs->ARM_r7 = __NR_restart_syscall;
667 u32 swival = __NR_restart_syscall;
670 usp = (u32 __user *)regs->ARM_sp;
673 * Either we supports OABI only, or we have
674 * EABI with the OABI compat layer enabled.
675 * In the later case we don't know if user
676 * space is EABI or not, and if not we must
677 * not clobber r7. Always using the OABI
678 * syscall solves that issue and works for
681 swival = swival - __NR_SYSCALL_BASE + __NR_OABI_SYSCALL_BASE;
683 put_user(regs->ARM_pc, &usp[0]);
684 /* swi __NR_restart_syscall */
685 put_user(0xef000000 | swival, &usp[1]);
686 /* ldr pc, [sp], #12 */
687 put_user(0xe49df00c, &usp[2]);
689 flush_icache_range((unsigned long)usp,
690 (unsigned long)(usp + 3));
692 regs->ARM_pc = regs->ARM_sp + 4;
696 if (regs->ARM_r0 == -ERESTARTNOHAND ||
697 regs->ARM_r0 == -ERESTARTSYS ||
698 regs->ARM_r0 == -ERESTARTNOINTR) {
699 setup_syscall_restart(regs);
702 single_step_set(current);
707 do_notify_resume(struct pt_regs *regs, unsigned int thread_flags, int syscall)
709 if (thread_flags & _TIF_SIGPENDING)
710 do_signal(¤t->blocked, regs, syscall);
712 if (thread_flags & _TIF_NOTIFY_RESUME) {
713 clear_thread_flag(TIF_NOTIFY_RESUME);
714 tracehook_notify_resume(regs);
715 if (current->replacement_session_keyring)
716 key_replace_session_keyring();