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/config.h>
11 #include <linux/errno.h>
12 #include <linux/signal.h>
13 #include <linux/ptrace.h>
14 #include <linux/personality.h>
16 #include <asm/cacheflush.h>
17 #include <asm/ucontext.h>
18 #include <asm/uaccess.h>
19 #include <asm/unistd.h>
24 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
27 * For ARM syscalls, we encode the syscall number into the instruction.
29 #define SWI_SYS_SIGRETURN (0xef000000|(__NR_sigreturn))
30 #define SWI_SYS_RT_SIGRETURN (0xef000000|(__NR_rt_sigreturn))
33 * With EABI, the syscall number has to be loaded into r7.
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))
39 * For Thumb syscalls, we pass the syscall number via r7. We therefore
40 * need two 16-bit instructions.
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))
45 const 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,
50 static int do_signal(sigset_t *oldset, struct pt_regs * regs, int syscall);
53 * atomically swap in the new signal mask, and wait for a signal.
55 asmlinkage int sys_sigsuspend(int restart, unsigned long oldmask, old_sigset_t mask, struct pt_regs *regs)
60 spin_lock_irq(¤t->sighand->siglock);
61 saveset = current->blocked;
62 siginitset(¤t->blocked, mask);
64 spin_unlock_irq(¤t->sighand->siglock);
65 regs->ARM_r0 = -EINTR;
68 current->state = TASK_INTERRUPTIBLE;
70 if (do_signal(&saveset, regs, 0))
76 sys_rt_sigsuspend(sigset_t __user *unewset, size_t sigsetsize, struct pt_regs *regs)
78 sigset_t saveset, newset;
80 /* XXX: Don't preclude handling different sized sigset_t's. */
81 if (sigsetsize != sizeof(sigset_t))
84 if (copy_from_user(&newset, unewset, sizeof(newset)))
86 sigdelsetmask(&newset, ~_BLOCKABLE);
88 spin_lock_irq(¤t->sighand->siglock);
89 saveset = current->blocked;
90 current->blocked = newset;
92 spin_unlock_irq(¤t->sighand->siglock);
93 regs->ARM_r0 = -EINTR;
96 current->state = TASK_INTERRUPTIBLE;
98 if (do_signal(&saveset, regs, 0))
104 sys_sigaction(int sig, const struct old_sigaction __user *act,
105 struct old_sigaction __user *oact)
107 struct k_sigaction new_ka, old_ka;
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))
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);
121 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
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))
128 __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
129 __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
137 /* iwmmxt_area is 0x98 bytes long, preceeded by 8 bytes of signature */
138 #define IWMMXT_STORAGE_SIZE (0x98 + 8)
139 #define IWMMXT_MAGIC0 0x12ef842a
140 #define IWMMXT_MAGIC1 0x1c07ca71
142 struct iwmmxt_sigframe {
143 unsigned long magic0;
144 unsigned long magic1;
145 unsigned long storage[0x98/4];
148 static int preserve_iwmmxt_context(struct iwmmxt_sigframe *frame)
150 char kbuf[sizeof(*frame) + 8];
151 struct iwmmxt_sigframe *kframe;
153 /* the iWMMXt context must be 64 bit aligned */
154 kframe = (struct iwmmxt_sigframe *)((unsigned long)(kbuf + 8) & ~7);
155 kframe->magic0 = IWMMXT_MAGIC0;
156 kframe->magic1 = IWMMXT_MAGIC1;
157 iwmmxt_task_copy(current_thread_info(), &kframe->storage);
158 return __copy_to_user(frame, kframe, sizeof(*frame));
161 static int restore_iwmmxt_context(struct iwmmxt_sigframe *frame)
163 char kbuf[sizeof(*frame) + 8];
164 struct iwmmxt_sigframe *kframe;
166 /* the iWMMXt context must be 64 bit aligned */
167 kframe = (struct iwmmxt_sigframe *)((unsigned long)(kbuf + 8) & ~7);
168 if (__copy_from_user(kframe, frame, sizeof(*frame)))
170 if (kframe->magic0 != IWMMXT_MAGIC0 ||
171 kframe->magic1 != IWMMXT_MAGIC1)
173 iwmmxt_task_restore(current_thread_info(), &kframe->storage);
180 * Auxiliary signal frame. This saves stuff like FP state.
181 * The layout of this structure is not part of the user ABI.
183 struct aux_sigframe {
185 struct iwmmxt_sigframe iwmmxt;
193 * Do a signal return; undo the signal stack. These are aligned to 64-bit.
197 unsigned long retcode[2];
198 struct aux_sigframe aux __attribute__((aligned(8)));
206 static int restore_sigframe(struct pt_regs *regs, struct sigframe __user *sf)
211 err = __copy_from_user(&set, &sf->uc.uc_sigmask, sizeof(set));
213 sigdelsetmask(&set, ~_BLOCKABLE);
214 spin_lock_irq(¤t->sighand->siglock);
215 current->blocked = set;
217 spin_unlock_irq(¤t->sighand->siglock);
220 __get_user_error(regs->ARM_r0, &sf->uc.uc_mcontext.arm_r0, err);
221 __get_user_error(regs->ARM_r1, &sf->uc.uc_mcontext.arm_r1, err);
222 __get_user_error(regs->ARM_r2, &sf->uc.uc_mcontext.arm_r2, err);
223 __get_user_error(regs->ARM_r3, &sf->uc.uc_mcontext.arm_r3, err);
224 __get_user_error(regs->ARM_r4, &sf->uc.uc_mcontext.arm_r4, err);
225 __get_user_error(regs->ARM_r5, &sf->uc.uc_mcontext.arm_r5, err);
226 __get_user_error(regs->ARM_r6, &sf->uc.uc_mcontext.arm_r6, err);
227 __get_user_error(regs->ARM_r7, &sf->uc.uc_mcontext.arm_r7, err);
228 __get_user_error(regs->ARM_r8, &sf->uc.uc_mcontext.arm_r8, err);
229 __get_user_error(regs->ARM_r9, &sf->uc.uc_mcontext.arm_r9, err);
230 __get_user_error(regs->ARM_r10, &sf->uc.uc_mcontext.arm_r10, err);
231 __get_user_error(regs->ARM_fp, &sf->uc.uc_mcontext.arm_fp, err);
232 __get_user_error(regs->ARM_ip, &sf->uc.uc_mcontext.arm_ip, err);
233 __get_user_error(regs->ARM_sp, &sf->uc.uc_mcontext.arm_sp, err);
234 __get_user_error(regs->ARM_lr, &sf->uc.uc_mcontext.arm_lr, err);
235 __get_user_error(regs->ARM_pc, &sf->uc.uc_mcontext.arm_pc, err);
236 __get_user_error(regs->ARM_cpsr, &sf->uc.uc_mcontext.arm_cpsr, err);
238 err |= !valid_user_regs(regs);
241 if (err == 0 && test_thread_flag(TIF_USING_IWMMXT))
242 err |= restore_iwmmxt_context(&sf->aux.iwmmxt);
246 // err |= vfp_restore_state(&sf->aux.vfp);
252 asmlinkage int sys_sigreturn(struct pt_regs *regs)
254 struct sigframe __user *frame;
256 /* Always make any pending restarted system calls return -EINTR */
257 current_thread_info()->restart_block.fn = do_no_restart_syscall;
260 * Since we stacked the signal on a 64-bit boundary,
261 * then 'sp' should be word aligned here. If it's
262 * not, then the user is trying to mess with us.
264 if (regs->ARM_sp & 7)
267 frame = (struct sigframe __user *)regs->ARM_sp;
269 if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
272 if (restore_sigframe(regs, frame))
275 /* Send SIGTRAP if we're single-stepping */
276 if (current->ptrace & PT_SINGLESTEP) {
277 ptrace_cancel_bpt(current);
278 send_sig(SIGTRAP, current, 1);
284 force_sig(SIGSEGV, current);
288 asmlinkage int sys_rt_sigreturn(struct pt_regs *regs)
290 struct rt_sigframe __user *frame;
292 /* Always make any pending restarted system calls return -EINTR */
293 current_thread_info()->restart_block.fn = do_no_restart_syscall;
296 * Since we stacked the signal on a 64-bit boundary,
297 * then 'sp' should be word aligned here. If it's
298 * not, then the user is trying to mess with us.
300 if (regs->ARM_sp & 7)
303 frame = (struct rt_sigframe __user *)regs->ARM_sp;
305 if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
308 if (restore_sigframe(regs, &frame->sig))
311 if (do_sigaltstack(&frame->sig.uc.uc_stack, NULL, regs->ARM_sp) == -EFAULT)
314 /* Send SIGTRAP if we're single-stepping */
315 if (current->ptrace & PT_SINGLESTEP) {
316 ptrace_cancel_bpt(current);
317 send_sig(SIGTRAP, current, 1);
323 force_sig(SIGSEGV, current);
328 setup_sigcontext(struct sigcontext __user *sc, struct aux_sigframe __user *aux,
329 struct pt_regs *regs, unsigned long mask)
333 __put_user_error(regs->ARM_r0, &sc->arm_r0, err);
334 __put_user_error(regs->ARM_r1, &sc->arm_r1, err);
335 __put_user_error(regs->ARM_r2, &sc->arm_r2, err);
336 __put_user_error(regs->ARM_r3, &sc->arm_r3, err);
337 __put_user_error(regs->ARM_r4, &sc->arm_r4, err);
338 __put_user_error(regs->ARM_r5, &sc->arm_r5, err);
339 __put_user_error(regs->ARM_r6, &sc->arm_r6, err);
340 __put_user_error(regs->ARM_r7, &sc->arm_r7, err);
341 __put_user_error(regs->ARM_r8, &sc->arm_r8, err);
342 __put_user_error(regs->ARM_r9, &sc->arm_r9, err);
343 __put_user_error(regs->ARM_r10, &sc->arm_r10, err);
344 __put_user_error(regs->ARM_fp, &sc->arm_fp, err);
345 __put_user_error(regs->ARM_ip, &sc->arm_ip, err);
346 __put_user_error(regs->ARM_sp, &sc->arm_sp, err);
347 __put_user_error(regs->ARM_lr, &sc->arm_lr, err);
348 __put_user_error(regs->ARM_pc, &sc->arm_pc, err);
349 __put_user_error(regs->ARM_cpsr, &sc->arm_cpsr, err);
351 __put_user_error(current->thread.trap_no, &sc->trap_no, err);
352 __put_user_error(current->thread.error_code, &sc->error_code, err);
353 __put_user_error(current->thread.address, &sc->fault_address, err);
354 __put_user_error(mask, &sc->oldmask, err);
357 if (err == 0 && test_thread_flag(TIF_USING_IWMMXT))
358 err |= preserve_iwmmxt_context(&aux->iwmmxt);
362 // err |= vfp_save_state(&aux->vfp);
368 static inline void __user *
369 get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, int framesize)
371 unsigned long sp = regs->ARM_sp;
375 * This is the X/Open sanctioned signal stack switching.
377 if ((ka->sa.sa_flags & SA_ONSTACK) && !sas_ss_flags(sp))
378 sp = current->sas_ss_sp + current->sas_ss_size;
381 * ATPCS B01 mandates 8-byte alignment
383 frame = (void __user *)((sp - framesize) & ~7);
386 * Check that we can actually write to the signal frame.
388 if (!access_ok(VERIFY_WRITE, frame, framesize))
395 setup_return(struct pt_regs *regs, struct k_sigaction *ka,
396 unsigned long __user *rc, void __user *frame, int usig)
398 unsigned long handler = (unsigned long)ka->sa.sa_handler;
399 unsigned long retcode;
401 unsigned long cpsr = regs->ARM_cpsr & ~PSR_f;
404 * Maybe we need to deliver a 32-bit signal to a 26-bit task.
406 if (ka->sa.sa_flags & SA_THIRTYTWO)
407 cpsr = (cpsr & ~MODE_MASK) | USR_MODE;
409 #ifdef CONFIG_ARM_THUMB
410 if (elf_hwcap & HWCAP_THUMB) {
412 * The LSB of the handler determines if we're going to
413 * be using THUMB or ARM mode for this signal handler.
424 if (ka->sa.sa_flags & SA_RESTORER) {
425 retcode = (unsigned long)ka->sa.sa_restorer;
427 unsigned int idx = thumb << 1;
429 if (ka->sa.sa_flags & SA_SIGINFO)
432 if (__put_user(sigreturn_codes[idx], rc) ||
433 __put_user(sigreturn_codes[idx+1], rc+1))
436 if (cpsr & MODE32_BIT) {
438 * 32-bit code can use the new high-page
439 * signal return code support.
441 retcode = KERN_SIGRETURN_CODE + (idx << 2) + thumb;
444 * Ensure that the instruction cache sees
445 * the return code written onto the stack.
447 flush_icache_range((unsigned long)rc,
448 (unsigned long)(rc + 2));
450 retcode = ((unsigned long)rc) + thumb;
455 regs->ARM_sp = (unsigned long)frame;
456 regs->ARM_lr = retcode;
457 regs->ARM_pc = handler;
458 regs->ARM_cpsr = cpsr;
464 setup_frame(int usig, struct k_sigaction *ka, sigset_t *set, struct pt_regs *regs)
466 struct sigframe __user *frame = get_sigframe(ka, regs, sizeof(*frame));
472 err |= setup_sigcontext(&frame->uc.uc_mcontext, &frame->aux, regs, set->sig[0]);
473 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
476 err = setup_return(regs, ka, frame->retcode, frame, usig);
482 setup_rt_frame(int usig, struct k_sigaction *ka, siginfo_t *info,
483 sigset_t *set, struct pt_regs *regs)
485 struct rt_sigframe __user *frame = get_sigframe(ka, regs, sizeof(*frame));
492 err |= copy_siginfo_to_user(&frame->info, info);
494 __put_user_error(0, &frame->sig.uc.uc_flags, err);
495 __put_user_error(NULL, &frame->sig.uc.uc_link, err);
497 memset(&stack, 0, sizeof(stack));
498 stack.ss_sp = (void __user *)current->sas_ss_sp;
499 stack.ss_flags = sas_ss_flags(regs->ARM_sp);
500 stack.ss_size = current->sas_ss_size;
501 err |= __copy_to_user(&frame->sig.uc.uc_stack, &stack, sizeof(stack));
503 err |= setup_sigcontext(&frame->sig.uc.uc_mcontext, &frame->sig.aux,
505 err |= __copy_to_user(&frame->sig.uc.uc_sigmask, set, sizeof(*set));
508 err = setup_return(regs, ka, frame->sig.retcode, frame, usig);
512 * For realtime signals we must also set the second and third
513 * arguments for the signal handler.
514 * -- Peter Maydell <pmaydell@chiark.greenend.org.uk> 2000-12-06
516 regs->ARM_r1 = (unsigned long)&frame->info;
517 regs->ARM_r2 = (unsigned long)&frame->sig.uc;
523 static inline void restart_syscall(struct pt_regs *regs)
525 regs->ARM_r0 = regs->ARM_ORIG_r0;
526 regs->ARM_pc -= thumb_mode(regs) ? 2 : 4;
530 * OK, we're invoking a handler
533 handle_signal(unsigned long sig, struct k_sigaction *ka,
534 siginfo_t *info, sigset_t *oldset,
535 struct pt_regs * regs, int syscall)
537 struct thread_info *thread = current_thread_info();
538 struct task_struct *tsk = current;
543 * If we were from a system call, check for system call restarting...
546 switch (regs->ARM_r0) {
547 case -ERESTART_RESTARTBLOCK:
548 case -ERESTARTNOHAND:
549 regs->ARM_r0 = -EINTR;
552 if (!(ka->sa.sa_flags & SA_RESTART)) {
553 regs->ARM_r0 = -EINTR;
557 case -ERESTARTNOINTR:
558 restart_syscall(regs);
563 * translate the signal
565 if (usig < 32 && thread->exec_domain && thread->exec_domain->signal_invmap)
566 usig = thread->exec_domain->signal_invmap[usig];
569 * Set up the stack frame
571 if (ka->sa.sa_flags & SA_SIGINFO)
572 ret = setup_rt_frame(usig, ka, info, oldset, regs);
574 ret = setup_frame(usig, ka, oldset, regs);
577 * Check that the resulting registers are actually sane.
579 ret |= !valid_user_regs(regs);
582 force_sigsegv(sig, tsk);
587 * Block the signal if we were successful.
589 spin_lock_irq(&tsk->sighand->siglock);
590 sigorsets(&tsk->blocked, &tsk->blocked,
592 if (!(ka->sa.sa_flags & SA_NODEFER))
593 sigaddset(&tsk->blocked, sig);
595 spin_unlock_irq(&tsk->sighand->siglock);
600 * Note that 'init' is a special process: it doesn't get signals it doesn't
601 * want to handle. Thus you cannot kill init even with a SIGKILL even by
604 * Note that we go through the signals twice: once to check the signals that
605 * the kernel can handle, and then we build all the user-level signal handling
606 * stack-frames in one go after that.
608 static int do_signal(sigset_t *oldset, struct pt_regs *regs, int syscall)
610 struct k_sigaction ka;
615 * We want the common case to go fast, which
616 * is why we may in certain cases get here from
617 * kernel mode. Just return without doing anything
620 if (!user_mode(regs))
626 if (current->ptrace & PT_SINGLESTEP)
627 ptrace_cancel_bpt(current);
629 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
631 handle_signal(signr, &ka, &info, oldset, regs, syscall);
632 if (current->ptrace & PT_SINGLESTEP)
633 ptrace_set_bpt(current);
639 * No signal to deliver to the process - restart the syscall.
642 if (regs->ARM_r0 == -ERESTART_RESTARTBLOCK) {
643 if (thumb_mode(regs)) {
644 regs->ARM_r7 = __NR_restart_syscall;
650 usp = (u32 __user *)regs->ARM_sp;
652 put_user(regs->ARM_pc, &usp[0]);
653 /* swi __NR_restart_syscall */
654 put_user(0xef000000 | __NR_restart_syscall, &usp[1]);
655 /* ldr pc, [sp], #12 */
656 put_user(0xe49df00c, &usp[2]);
658 flush_icache_range((unsigned long)usp,
659 (unsigned long)(usp + 3));
661 regs->ARM_pc = regs->ARM_sp + 4;
664 if (regs->ARM_r0 == -ERESTARTNOHAND ||
665 regs->ARM_r0 == -ERESTARTSYS ||
666 regs->ARM_r0 == -ERESTARTNOINTR) {
667 restart_syscall(regs);
670 if (current->ptrace & PT_SINGLESTEP)
671 ptrace_set_bpt(current);
676 do_notify_resume(struct pt_regs *regs, unsigned int thread_flags, int syscall)
678 if (thread_flags & _TIF_SIGPENDING)
679 do_signal(¤t->blocked, regs, syscall);