2 * linux/arch/arm/kernel/signal.c
4 * Copyright (C) 1995-2009 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>
26 * For ARM syscalls, we encode the syscall number into the instruction.
28 #define SWI_SYS_SIGRETURN (0xef000000|(__NR_sigreturn)|(__NR_OABI_SYSCALL_BASE))
29 #define SWI_SYS_RT_SIGRETURN (0xef000000|(__NR_rt_sigreturn)|(__NR_OABI_SYSCALL_BASE))
32 * With EABI, the syscall number has to be loaded into r7.
34 #define MOV_R7_NR_SIGRETURN (0xe3a07000 | (__NR_sigreturn - __NR_SYSCALL_BASE))
35 #define MOV_R7_NR_RT_SIGRETURN (0xe3a07000 | (__NR_rt_sigreturn - __NR_SYSCALL_BASE))
38 * For Thumb syscalls, we pass the syscall number via r7. We therefore
39 * need two 16-bit instructions.
41 #define SWI_THUMB_SIGRETURN (0xdf00 << 16 | 0x2700 | (__NR_sigreturn - __NR_SYSCALL_BASE))
42 #define SWI_THUMB_RT_SIGRETURN (0xdf00 << 16 | 0x2700 | (__NR_rt_sigreturn - __NR_SYSCALL_BASE))
44 const unsigned long sigreturn_codes[7] = {
45 MOV_R7_NR_SIGRETURN, SWI_SYS_SIGRETURN, SWI_THUMB_SIGRETURN,
46 MOV_R7_NR_RT_SIGRETURN, SWI_SYS_RT_SIGRETURN, SWI_THUMB_RT_SIGRETURN,
50 * atomically swap in the new signal mask, and wait for a signal.
52 asmlinkage int sys_sigsuspend(int restart, unsigned long oldmask, old_sigset_t mask)
55 siginitset(&blocked, mask);
56 return sigsuspend(&blocked);
60 sys_sigaction(int sig, const struct old_sigaction __user *act,
61 struct old_sigaction __user *oact)
63 struct k_sigaction new_ka, old_ka;
68 if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
69 __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
70 __get_user(new_ka.sa.sa_restorer, &act->sa_restorer) ||
71 __get_user(new_ka.sa.sa_flags, &act->sa_flags) ||
72 __get_user(mask, &act->sa_mask))
74 siginitset(&new_ka.sa.sa_mask, mask);
77 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
80 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
81 __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
82 __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer) ||
83 __put_user(old_ka.sa.sa_flags, &oact->sa_flags) ||
84 __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask))
92 static int preserve_crunch_context(struct crunch_sigframe __user *frame)
94 char kbuf[sizeof(*frame) + 8];
95 struct crunch_sigframe *kframe;
97 /* the crunch context must be 64 bit aligned */
98 kframe = (struct crunch_sigframe *)((unsigned long)(kbuf + 8) & ~7);
99 kframe->magic = CRUNCH_MAGIC;
100 kframe->size = CRUNCH_STORAGE_SIZE;
101 crunch_task_copy(current_thread_info(), &kframe->storage);
102 return __copy_to_user(frame, kframe, sizeof(*frame));
105 static int restore_crunch_context(struct crunch_sigframe __user *frame)
107 char kbuf[sizeof(*frame) + 8];
108 struct crunch_sigframe *kframe;
110 /* the crunch context must be 64 bit aligned */
111 kframe = (struct crunch_sigframe *)((unsigned long)(kbuf + 8) & ~7);
112 if (__copy_from_user(kframe, frame, sizeof(*frame)))
114 if (kframe->magic != CRUNCH_MAGIC ||
115 kframe->size != CRUNCH_STORAGE_SIZE)
117 crunch_task_restore(current_thread_info(), &kframe->storage);
124 static int preserve_iwmmxt_context(struct iwmmxt_sigframe *frame)
126 char kbuf[sizeof(*frame) + 8];
127 struct iwmmxt_sigframe *kframe;
129 /* the iWMMXt context must be 64 bit aligned */
130 kframe = (struct iwmmxt_sigframe *)((unsigned long)(kbuf + 8) & ~7);
131 kframe->magic = IWMMXT_MAGIC;
132 kframe->size = IWMMXT_STORAGE_SIZE;
133 iwmmxt_task_copy(current_thread_info(), &kframe->storage);
134 return __copy_to_user(frame, kframe, sizeof(*frame));
137 static int restore_iwmmxt_context(struct iwmmxt_sigframe *frame)
139 char kbuf[sizeof(*frame) + 8];
140 struct iwmmxt_sigframe *kframe;
142 /* the iWMMXt context must be 64 bit aligned */
143 kframe = (struct iwmmxt_sigframe *)((unsigned long)(kbuf + 8) & ~7);
144 if (__copy_from_user(kframe, frame, sizeof(*frame)))
146 if (kframe->magic != IWMMXT_MAGIC ||
147 kframe->size != IWMMXT_STORAGE_SIZE)
149 iwmmxt_task_restore(current_thread_info(), &kframe->storage);
157 static int preserve_vfp_context(struct vfp_sigframe __user *frame)
159 const unsigned long magic = VFP_MAGIC;
160 const unsigned long size = VFP_STORAGE_SIZE;
163 __put_user_error(magic, &frame->magic, err);
164 __put_user_error(size, &frame->size, err);
169 return vfp_preserve_user_clear_hwstate(&frame->ufp, &frame->ufp_exc);
172 static int restore_vfp_context(struct vfp_sigframe __user *frame)
178 __get_user_error(magic, &frame->magic, err);
179 __get_user_error(size, &frame->size, err);
183 if (magic != VFP_MAGIC || size != VFP_STORAGE_SIZE)
186 return vfp_restore_user_hwstate(&frame->ufp, &frame->ufp_exc);
192 * Do a signal return; undo the signal stack. These are aligned to 64-bit.
196 unsigned long retcode[2];
204 static int restore_sigframe(struct pt_regs *regs, struct sigframe __user *sf)
206 struct aux_sigframe __user *aux;
210 err = __copy_from_user(&set, &sf->uc.uc_sigmask, sizeof(set));
212 set_current_blocked(&set);
214 __get_user_error(regs->ARM_r0, &sf->uc.uc_mcontext.arm_r0, err);
215 __get_user_error(regs->ARM_r1, &sf->uc.uc_mcontext.arm_r1, err);
216 __get_user_error(regs->ARM_r2, &sf->uc.uc_mcontext.arm_r2, err);
217 __get_user_error(regs->ARM_r3, &sf->uc.uc_mcontext.arm_r3, err);
218 __get_user_error(regs->ARM_r4, &sf->uc.uc_mcontext.arm_r4, err);
219 __get_user_error(regs->ARM_r5, &sf->uc.uc_mcontext.arm_r5, err);
220 __get_user_error(regs->ARM_r6, &sf->uc.uc_mcontext.arm_r6, err);
221 __get_user_error(regs->ARM_r7, &sf->uc.uc_mcontext.arm_r7, err);
222 __get_user_error(regs->ARM_r8, &sf->uc.uc_mcontext.arm_r8, err);
223 __get_user_error(regs->ARM_r9, &sf->uc.uc_mcontext.arm_r9, err);
224 __get_user_error(regs->ARM_r10, &sf->uc.uc_mcontext.arm_r10, err);
225 __get_user_error(regs->ARM_fp, &sf->uc.uc_mcontext.arm_fp, err);
226 __get_user_error(regs->ARM_ip, &sf->uc.uc_mcontext.arm_ip, err);
227 __get_user_error(regs->ARM_sp, &sf->uc.uc_mcontext.arm_sp, err);
228 __get_user_error(regs->ARM_lr, &sf->uc.uc_mcontext.arm_lr, err);
229 __get_user_error(regs->ARM_pc, &sf->uc.uc_mcontext.arm_pc, err);
230 __get_user_error(regs->ARM_cpsr, &sf->uc.uc_mcontext.arm_cpsr, err);
232 err |= !valid_user_regs(regs);
234 aux = (struct aux_sigframe __user *) sf->uc.uc_regspace;
237 err |= restore_crunch_context(&aux->crunch);
240 if (err == 0 && test_thread_flag(TIF_USING_IWMMXT))
241 err |= restore_iwmmxt_context(&aux->iwmmxt);
245 err |= restore_vfp_context(&aux->vfp);
251 asmlinkage int sys_sigreturn(struct pt_regs *regs)
253 struct sigframe __user *frame;
255 /* Always make any pending restarted system calls return -EINTR */
256 current_thread_info()->restart_block.fn = do_no_restart_syscall;
259 * Since we stacked the signal on a 64-bit boundary,
260 * then 'sp' should be word aligned here. If it's
261 * not, then the user is trying to mess with us.
263 if (regs->ARM_sp & 7)
266 frame = (struct sigframe __user *)regs->ARM_sp;
268 if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
271 if (restore_sigframe(regs, frame))
277 force_sig(SIGSEGV, current);
281 asmlinkage int sys_rt_sigreturn(struct pt_regs *regs)
283 struct rt_sigframe __user *frame;
285 /* Always make any pending restarted system calls return -EINTR */
286 current_thread_info()->restart_block.fn = do_no_restart_syscall;
289 * Since we stacked the signal on a 64-bit boundary,
290 * then 'sp' should be word aligned here. If it's
291 * not, then the user is trying to mess with us.
293 if (regs->ARM_sp & 7)
296 frame = (struct rt_sigframe __user *)regs->ARM_sp;
298 if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
301 if (restore_sigframe(regs, &frame->sig))
304 if (do_sigaltstack(&frame->sig.uc.uc_stack, NULL, regs->ARM_sp) == -EFAULT)
310 force_sig(SIGSEGV, current);
315 setup_sigframe(struct sigframe __user *sf, struct pt_regs *regs, sigset_t *set)
317 struct aux_sigframe __user *aux;
320 __put_user_error(regs->ARM_r0, &sf->uc.uc_mcontext.arm_r0, err);
321 __put_user_error(regs->ARM_r1, &sf->uc.uc_mcontext.arm_r1, err);
322 __put_user_error(regs->ARM_r2, &sf->uc.uc_mcontext.arm_r2, err);
323 __put_user_error(regs->ARM_r3, &sf->uc.uc_mcontext.arm_r3, err);
324 __put_user_error(regs->ARM_r4, &sf->uc.uc_mcontext.arm_r4, err);
325 __put_user_error(regs->ARM_r5, &sf->uc.uc_mcontext.arm_r5, err);
326 __put_user_error(regs->ARM_r6, &sf->uc.uc_mcontext.arm_r6, err);
327 __put_user_error(regs->ARM_r7, &sf->uc.uc_mcontext.arm_r7, err);
328 __put_user_error(regs->ARM_r8, &sf->uc.uc_mcontext.arm_r8, err);
329 __put_user_error(regs->ARM_r9, &sf->uc.uc_mcontext.arm_r9, err);
330 __put_user_error(regs->ARM_r10, &sf->uc.uc_mcontext.arm_r10, err);
331 __put_user_error(regs->ARM_fp, &sf->uc.uc_mcontext.arm_fp, err);
332 __put_user_error(regs->ARM_ip, &sf->uc.uc_mcontext.arm_ip, err);
333 __put_user_error(regs->ARM_sp, &sf->uc.uc_mcontext.arm_sp, err);
334 __put_user_error(regs->ARM_lr, &sf->uc.uc_mcontext.arm_lr, err);
335 __put_user_error(regs->ARM_pc, &sf->uc.uc_mcontext.arm_pc, err);
336 __put_user_error(regs->ARM_cpsr, &sf->uc.uc_mcontext.arm_cpsr, err);
338 __put_user_error(current->thread.trap_no, &sf->uc.uc_mcontext.trap_no, err);
339 __put_user_error(current->thread.error_code, &sf->uc.uc_mcontext.error_code, err);
340 __put_user_error(current->thread.address, &sf->uc.uc_mcontext.fault_address, err);
341 __put_user_error(set->sig[0], &sf->uc.uc_mcontext.oldmask, err);
343 err |= __copy_to_user(&sf->uc.uc_sigmask, set, sizeof(*set));
345 aux = (struct aux_sigframe __user *) sf->uc.uc_regspace;
348 err |= preserve_crunch_context(&aux->crunch);
351 if (err == 0 && test_thread_flag(TIF_USING_IWMMXT))
352 err |= preserve_iwmmxt_context(&aux->iwmmxt);
356 err |= preserve_vfp_context(&aux->vfp);
358 __put_user_error(0, &aux->end_magic, err);
363 static inline void __user *
364 get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, int framesize)
366 unsigned long sp = regs->ARM_sp;
370 * This is the X/Open sanctioned signal stack switching.
372 if ((ka->sa.sa_flags & SA_ONSTACK) && !sas_ss_flags(sp))
373 sp = current->sas_ss_sp + current->sas_ss_size;
376 * ATPCS B01 mandates 8-byte alignment
378 frame = (void __user *)((sp - framesize) & ~7);
381 * Check that we can actually write to the signal frame.
383 if (!access_ok(VERIFY_WRITE, frame, framesize))
390 setup_return(struct pt_regs *regs, struct k_sigaction *ka,
391 unsigned long __user *rc, void __user *frame, int usig)
393 unsigned long handler = (unsigned long)ka->sa.sa_handler;
394 unsigned long retcode;
396 unsigned long cpsr = regs->ARM_cpsr & ~(PSR_f | PSR_E_BIT);
398 cpsr |= PSR_ENDSTATE;
401 * Maybe we need to deliver a 32-bit signal to a 26-bit task.
403 if (ka->sa.sa_flags & SA_THIRTYTWO)
404 cpsr = (cpsr & ~MODE_MASK) | USR_MODE;
406 #ifdef CONFIG_ARM_THUMB
407 if (elf_hwcap & HWCAP_THUMB) {
409 * The LSB of the handler determines if we're going to
410 * be using THUMB or ARM mode for this signal handler.
416 #if __LINUX_ARM_ARCH__ >= 7
417 /* clear the If-Then Thumb-2 execution state */
418 cpsr &= ~PSR_IT_MASK;
425 if (ka->sa.sa_flags & SA_RESTORER) {
426 retcode = (unsigned long)ka->sa.sa_restorer;
428 unsigned int idx = thumb << 1;
430 if (ka->sa.sa_flags & SA_SIGINFO)
433 if (__put_user(sigreturn_codes[idx], rc) ||
434 __put_user(sigreturn_codes[idx+1], rc+1))
437 if (cpsr & MODE32_BIT) {
439 * 32-bit code can use the new high-page
440 * signal return code support.
442 retcode = KERN_SIGRETURN_CODE + (idx << 2) + thumb;
445 * Ensure that the instruction cache sees
446 * the return code written onto the stack.
448 flush_icache_range((unsigned long)rc,
449 (unsigned long)(rc + 2));
451 retcode = ((unsigned long)rc) + thumb;
456 regs->ARM_sp = (unsigned long)frame;
457 regs->ARM_lr = retcode;
458 regs->ARM_pc = handler;
459 regs->ARM_cpsr = cpsr;
465 setup_frame(int usig, struct k_sigaction *ka, sigset_t *set, struct pt_regs *regs)
467 struct sigframe __user *frame = get_sigframe(ka, regs, sizeof(*frame));
474 * Set uc.uc_flags to a value which sc.trap_no would never have.
476 __put_user_error(0x5ac3c35a, &frame->uc.uc_flags, err);
478 err |= setup_sigframe(frame, regs, set);
480 err = setup_return(regs, ka, frame->retcode, frame, usig);
486 setup_rt_frame(int usig, struct k_sigaction *ka, siginfo_t *info,
487 sigset_t *set, struct pt_regs *regs)
489 struct rt_sigframe __user *frame = get_sigframe(ka, regs, sizeof(*frame));
496 err |= copy_siginfo_to_user(&frame->info, info);
498 __put_user_error(0, &frame->sig.uc.uc_flags, err);
499 __put_user_error(NULL, &frame->sig.uc.uc_link, err);
501 memset(&stack, 0, sizeof(stack));
502 stack.ss_sp = (void __user *)current->sas_ss_sp;
503 stack.ss_flags = sas_ss_flags(regs->ARM_sp);
504 stack.ss_size = current->sas_ss_size;
505 err |= __copy_to_user(&frame->sig.uc.uc_stack, &stack, sizeof(stack));
507 err |= setup_sigframe(&frame->sig, regs, set);
509 err = setup_return(regs, ka, frame->sig.retcode, frame, usig);
513 * For realtime signals we must also set the second and third
514 * arguments for the signal handler.
515 * -- Peter Maydell <pmaydell@chiark.greenend.org.uk> 2000-12-06
517 regs->ARM_r1 = (unsigned long)&frame->info;
518 regs->ARM_r2 = (unsigned long)&frame->sig.uc;
525 * OK, we're invoking a handler
528 handle_signal(unsigned long sig, struct k_sigaction *ka,
529 siginfo_t *info, struct pt_regs *regs)
531 struct thread_info *thread = current_thread_info();
532 struct task_struct *tsk = current;
533 sigset_t *oldset = sigmask_to_save();
538 * translate the signal
540 if (usig < 32 && thread->exec_domain && thread->exec_domain->signal_invmap)
541 usig = thread->exec_domain->signal_invmap[usig];
544 * Set up the stack frame
546 if (ka->sa.sa_flags & SA_SIGINFO)
547 ret = setup_rt_frame(usig, ka, info, oldset, regs);
549 ret = setup_frame(usig, ka, oldset, regs);
552 * Check that the resulting registers are actually sane.
554 ret |= !valid_user_regs(regs);
557 force_sigsegv(sig, tsk);
560 signal_delivered(sig, info, ka, regs, 0);
564 * Note that 'init' is a special process: it doesn't get signals it doesn't
565 * want to handle. Thus you cannot kill init even with a SIGKILL even by
568 * Note that we go through the signals twice: once to check the signals that
569 * the kernel can handle, and then we build all the user-level signal handling
570 * stack-frames in one go after that.
572 static void do_signal(struct pt_regs *regs, int syscall)
574 unsigned int retval = 0, continue_addr = 0, restart_addr = 0;
575 struct k_sigaction ka;
580 * If we were from a system call, check for system call restarting...
583 continue_addr = regs->ARM_pc;
584 restart_addr = continue_addr - (thumb_mode(regs) ? 2 : 4);
585 retval = regs->ARM_r0;
588 * Prepare for system call restart. We do this here so that a
589 * debugger will see the already changed PSW.
592 case -ERESTARTNOHAND:
594 case -ERESTARTNOINTR:
595 case -ERESTART_RESTARTBLOCK:
596 regs->ARM_r0 = regs->ARM_ORIG_r0;
597 regs->ARM_pc = restart_addr;
603 * Get the signal to deliver. When running under ptrace, at this
604 * point the debugger may change all our registers ...
606 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
609 * Depending on the signal settings we may need to revert the
610 * decision to restart the system call. But skip this if a
611 * debugger has chosen to restart at a different PC.
613 if (regs->ARM_pc == restart_addr) {
614 if (retval == -ERESTARTNOHAND ||
615 retval == -ERESTART_RESTARTBLOCK
616 || (retval == -ERESTARTSYS
617 && !(ka.sa.sa_flags & SA_RESTART))) {
618 regs->ARM_r0 = -EINTR;
619 regs->ARM_pc = continue_addr;
621 clear_thread_flag(TIF_SYSCALL_RESTARTSYS);
624 handle_signal(signr, &ka, &info, regs);
630 * Handle restarting a different system call. As above,
631 * if a debugger has chosen to restart at a different PC,
632 * ignore the restart.
634 if (retval == -ERESTART_RESTARTBLOCK
635 && regs->ARM_pc == restart_addr)
636 set_thread_flag(TIF_SYSCALL_RESTARTSYS);
639 restore_saved_sigmask();
643 do_notify_resume(struct pt_regs *regs, unsigned int thread_flags, int syscall)
645 if (thread_flags & _TIF_SIGPENDING)
646 do_signal(regs, syscall);
648 if (thread_flags & _TIF_NOTIFY_RESUME) {
649 clear_thread_flag(TIF_NOTIFY_RESUME);
650 tracehook_notify_resume(regs);