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>
15 #include <linux/suspend.h>
17 #include <asm/cacheflush.h>
18 #include <asm/ucontext.h>
19 #include <asm/uaccess.h>
20 #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 * For Thumb syscalls, we pass the syscall number via r7. We therefore
34 * need two 16-bit instructions.
36 #define SWI_THUMB_SIGRETURN (0xdf00 << 16 | 0x2700 | (__NR_sigreturn - __NR_SYSCALL_BASE))
37 #define SWI_THUMB_RT_SIGRETURN (0xdf00 << 16 | 0x2700 | (__NR_rt_sigreturn - __NR_SYSCALL_BASE))
39 static const unsigned long retcodes[4] = {
40 SWI_SYS_SIGRETURN, SWI_THUMB_SIGRETURN,
41 SWI_SYS_RT_SIGRETURN, SWI_THUMB_RT_SIGRETURN
44 static int do_signal(sigset_t *oldset, struct pt_regs * regs, int syscall);
47 * atomically swap in the new signal mask, and wait for a signal.
49 asmlinkage int sys_sigsuspend(int restart, unsigned long oldmask, old_sigset_t mask, struct pt_regs *regs)
54 spin_lock_irq(¤t->sighand->siglock);
55 saveset = current->blocked;
56 siginitset(¤t->blocked, mask);
58 spin_unlock_irq(¤t->sighand->siglock);
59 regs->ARM_r0 = -EINTR;
62 current->state = TASK_INTERRUPTIBLE;
64 if (do_signal(&saveset, regs, 0))
70 sys_rt_sigsuspend(sigset_t __user *unewset, size_t sigsetsize, struct pt_regs *regs)
72 sigset_t saveset, newset;
74 /* XXX: Don't preclude handling different sized sigset_t's. */
75 if (sigsetsize != sizeof(sigset_t))
78 if (copy_from_user(&newset, unewset, sizeof(newset)))
80 sigdelsetmask(&newset, ~_BLOCKABLE);
82 spin_lock_irq(¤t->sighand->siglock);
83 saveset = current->blocked;
84 current->blocked = newset;
86 spin_unlock_irq(¤t->sighand->siglock);
87 regs->ARM_r0 = -EINTR;
90 current->state = TASK_INTERRUPTIBLE;
92 if (do_signal(&saveset, regs, 0))
98 sys_sigaction(int sig, const struct old_sigaction __user *act,
99 struct old_sigaction __user *oact)
101 struct k_sigaction new_ka, old_ka;
106 if (verify_area(VERIFY_READ, act, sizeof(*act)) ||
107 __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
108 __get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
110 __get_user(new_ka.sa.sa_flags, &act->sa_flags);
111 __get_user(mask, &act->sa_mask);
112 siginitset(&new_ka.sa.sa_mask, mask);
115 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
118 if (verify_area(VERIFY_WRITE, oact, sizeof(*oact)) ||
119 __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
120 __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
122 __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
123 __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
130 * Do a signal return; undo the signal stack.
134 struct sigcontext sc;
135 unsigned long extramask[_NSIG_WORDS-1];
136 unsigned long retcode;
141 struct siginfo __user *pinfo;
145 unsigned long retcode;
149 restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
153 __get_user_error(regs->ARM_r0, &sc->arm_r0, err);
154 __get_user_error(regs->ARM_r1, &sc->arm_r1, err);
155 __get_user_error(regs->ARM_r2, &sc->arm_r2, err);
156 __get_user_error(regs->ARM_r3, &sc->arm_r3, err);
157 __get_user_error(regs->ARM_r4, &sc->arm_r4, err);
158 __get_user_error(regs->ARM_r5, &sc->arm_r5, err);
159 __get_user_error(regs->ARM_r6, &sc->arm_r6, err);
160 __get_user_error(regs->ARM_r7, &sc->arm_r7, err);
161 __get_user_error(regs->ARM_r8, &sc->arm_r8, err);
162 __get_user_error(regs->ARM_r9, &sc->arm_r9, err);
163 __get_user_error(regs->ARM_r10, &sc->arm_r10, err);
164 __get_user_error(regs->ARM_fp, &sc->arm_fp, err);
165 __get_user_error(regs->ARM_ip, &sc->arm_ip, err);
166 __get_user_error(regs->ARM_sp, &sc->arm_sp, err);
167 __get_user_error(regs->ARM_lr, &sc->arm_lr, err);
168 __get_user_error(regs->ARM_pc, &sc->arm_pc, err);
169 __get_user_error(regs->ARM_cpsr, &sc->arm_cpsr, err);
171 err |= !valid_user_regs(regs);
176 asmlinkage int sys_sigreturn(struct pt_regs *regs)
178 struct sigframe __user *frame;
181 /* Always make any pending restarted system calls return -EINTR */
182 current_thread_info()->restart_block.fn = do_no_restart_syscall;
185 * Since we stacked the signal on a 64-bit boundary,
186 * then 'sp' should be word aligned here. If it's
187 * not, then the user is trying to mess with us.
189 if (regs->ARM_sp & 7)
192 frame = (struct sigframe __user *)regs->ARM_sp;
194 if (verify_area(VERIFY_READ, frame, sizeof (*frame)))
196 if (__get_user(set.sig[0], &frame->sc.oldmask)
198 && __copy_from_user(&set.sig[1], &frame->extramask,
199 sizeof(frame->extramask))))
202 sigdelsetmask(&set, ~_BLOCKABLE);
203 spin_lock_irq(¤t->sighand->siglock);
204 current->blocked = set;
206 spin_unlock_irq(¤t->sighand->siglock);
208 if (restore_sigcontext(regs, &frame->sc))
211 /* Send SIGTRAP if we're single-stepping */
212 if (current->ptrace & PT_SINGLESTEP) {
213 ptrace_cancel_bpt(current);
214 send_sig(SIGTRAP, current, 1);
220 force_sig(SIGSEGV, current);
224 asmlinkage int sys_rt_sigreturn(struct pt_regs *regs)
226 struct rt_sigframe __user *frame;
229 /* Always make any pending restarted system calls return -EINTR */
230 current_thread_info()->restart_block.fn = do_no_restart_syscall;
233 * Since we stacked the signal on a 64-bit boundary,
234 * then 'sp' should be word aligned here. If it's
235 * not, then the user is trying to mess with us.
237 if (regs->ARM_sp & 7)
240 frame = (struct rt_sigframe __user *)regs->ARM_sp;
242 if (verify_area(VERIFY_READ, frame, sizeof (*frame)))
244 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
247 sigdelsetmask(&set, ~_BLOCKABLE);
248 spin_lock_irq(¤t->sighand->siglock);
249 current->blocked = set;
251 spin_unlock_irq(¤t->sighand->siglock);
253 if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
256 if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->ARM_sp) == -EFAULT)
259 /* Send SIGTRAP if we're single-stepping */
260 if (current->ptrace & PT_SINGLESTEP) {
261 ptrace_cancel_bpt(current);
262 send_sig(SIGTRAP, current, 1);
268 force_sig(SIGSEGV, current);
273 setup_sigcontext(struct sigcontext __user *sc, /*struct _fpstate *fpstate,*/
274 struct pt_regs *regs, unsigned long mask)
278 __put_user_error(regs->ARM_r0, &sc->arm_r0, err);
279 __put_user_error(regs->ARM_r1, &sc->arm_r1, err);
280 __put_user_error(regs->ARM_r2, &sc->arm_r2, err);
281 __put_user_error(regs->ARM_r3, &sc->arm_r3, err);
282 __put_user_error(regs->ARM_r4, &sc->arm_r4, err);
283 __put_user_error(regs->ARM_r5, &sc->arm_r5, err);
284 __put_user_error(regs->ARM_r6, &sc->arm_r6, err);
285 __put_user_error(regs->ARM_r7, &sc->arm_r7, err);
286 __put_user_error(regs->ARM_r8, &sc->arm_r8, err);
287 __put_user_error(regs->ARM_r9, &sc->arm_r9, err);
288 __put_user_error(regs->ARM_r10, &sc->arm_r10, err);
289 __put_user_error(regs->ARM_fp, &sc->arm_fp, err);
290 __put_user_error(regs->ARM_ip, &sc->arm_ip, err);
291 __put_user_error(regs->ARM_sp, &sc->arm_sp, err);
292 __put_user_error(regs->ARM_lr, &sc->arm_lr, err);
293 __put_user_error(regs->ARM_pc, &sc->arm_pc, err);
294 __put_user_error(regs->ARM_cpsr, &sc->arm_cpsr, err);
296 __put_user_error(current->thread.trap_no, &sc->trap_no, err);
297 __put_user_error(current->thread.error_code, &sc->error_code, err);
298 __put_user_error(current->thread.address, &sc->fault_address, err);
299 __put_user_error(mask, &sc->oldmask, err);
304 static inline void __user *
305 get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, int framesize)
307 unsigned long sp = regs->ARM_sp;
310 * This is the X/Open sanctioned signal stack switching.
312 if ((ka->sa.sa_flags & SA_ONSTACK) && !sas_ss_flags(sp))
313 sp = current->sas_ss_sp + current->sas_ss_size;
316 * ATPCS B01 mandates 8-byte alignment
318 return (void __user *)((sp - framesize) & ~7);
322 setup_return(struct pt_regs *regs, struct k_sigaction *ka,
323 unsigned long __user *rc, void __user *frame, int usig)
325 unsigned long handler = (unsigned long)ka->sa.sa_handler;
326 unsigned long retcode;
328 unsigned long cpsr = regs->ARM_cpsr & ~PSR_f;
331 * Maybe we need to deliver a 32-bit signal to a 26-bit task.
333 if (ka->sa.sa_flags & SA_THIRTYTWO)
334 cpsr = (cpsr & ~MODE_MASK) | USR_MODE;
336 #ifdef CONFIG_ARM_THUMB
337 if (elf_hwcap & HWCAP_THUMB) {
339 * The LSB of the handler determines if we're going to
340 * be using THUMB or ARM mode for this signal handler.
351 if (ka->sa.sa_flags & SA_RESTORER) {
352 retcode = (unsigned long)ka->sa.sa_restorer;
354 unsigned int idx = thumb;
356 if (ka->sa.sa_flags & SA_SIGINFO)
359 if (__put_user(retcodes[idx], rc))
363 * Ensure that the instruction cache sees
364 * the return code written onto the stack.
366 flush_icache_range((unsigned long)rc,
367 (unsigned long)(rc + 1));
369 retcode = ((unsigned long)rc) + thumb;
373 regs->ARM_sp = (unsigned long)frame;
374 regs->ARM_lr = retcode;
375 regs->ARM_pc = handler;
376 regs->ARM_cpsr = cpsr;
382 setup_frame(int usig, struct k_sigaction *ka, sigset_t *set, struct pt_regs *regs)
384 struct sigframe __user *frame = get_sigframe(ka, regs, sizeof(*frame));
387 if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
390 err |= setup_sigcontext(&frame->sc, /*&frame->fpstate,*/ regs, set->sig[0]);
392 if (_NSIG_WORDS > 1) {
393 err |= __copy_to_user(frame->extramask, &set->sig[1],
394 sizeof(frame->extramask));
398 err = setup_return(regs, ka, &frame->retcode, frame, usig);
404 setup_rt_frame(int usig, struct k_sigaction *ka, siginfo_t *info,
405 sigset_t *set, struct pt_regs *regs)
407 struct rt_sigframe __user *frame = get_sigframe(ka, regs, sizeof(*frame));
411 if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
414 __put_user_error(&frame->info, &frame->pinfo, err);
415 __put_user_error(&frame->uc, &frame->puc, err);
416 err |= copy_siginfo_to_user(&frame->info, info);
418 __put_user_error(0, &frame->uc.uc_flags, err);
419 __put_user_error(NULL, &frame->uc.uc_link, err);
421 memset(&stack, 0, sizeof(stack));
422 stack.ss_sp = (void __user *)current->sas_ss_sp;
423 stack.ss_flags = sas_ss_flags(regs->ARM_sp);
424 stack.ss_size = current->sas_ss_size;
425 err |= __copy_to_user(&frame->uc.uc_stack, &stack, sizeof(stack));
427 err |= setup_sigcontext(&frame->uc.uc_mcontext, /*&frame->fpstate,*/
429 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
432 err = setup_return(regs, ka, &frame->retcode, frame, usig);
436 * For realtime signals we must also set the second and third
437 * arguments for the signal handler.
438 * -- Peter Maydell <pmaydell@chiark.greenend.org.uk> 2000-12-06
440 regs->ARM_r1 = (unsigned long)&frame->info;
441 regs->ARM_r2 = (unsigned long)&frame->uc;
447 static inline void restart_syscall(struct pt_regs *regs)
449 regs->ARM_r0 = regs->ARM_ORIG_r0;
450 regs->ARM_pc -= thumb_mode(regs) ? 2 : 4;
454 * OK, we're invoking a handler
457 handle_signal(unsigned long sig, siginfo_t *info, sigset_t *oldset,
458 struct pt_regs * regs, int syscall)
460 struct thread_info *thread = current_thread_info();
461 struct task_struct *tsk = current;
462 struct k_sigaction *ka = &tsk->sighand->action[sig-1];
467 * If we were from a system call, check for system call restarting...
470 switch (regs->ARM_r0) {
471 case -ERESTART_RESTARTBLOCK:
472 case -ERESTARTNOHAND:
473 regs->ARM_r0 = -EINTR;
476 if (!(ka->sa.sa_flags & SA_RESTART)) {
477 regs->ARM_r0 = -EINTR;
481 case -ERESTARTNOINTR:
482 restart_syscall(regs);
487 * translate the signal
489 if (usig < 32 && thread->exec_domain && thread->exec_domain->signal_invmap)
490 usig = thread->exec_domain->signal_invmap[usig];
493 * Set up the stack frame
495 if (ka->sa.sa_flags & SA_SIGINFO)
496 ret = setup_rt_frame(usig, ka, info, oldset, regs);
498 ret = setup_frame(usig, ka, oldset, regs);
501 * Check that the resulting registers are actually sane.
503 ret |= !valid_user_regs(regs);
506 * Block the signal if we were unsuccessful.
508 if (ret != 0 || !(ka->sa.sa_flags & SA_NODEFER)) {
509 spin_lock_irq(&tsk->sighand->siglock);
510 sigorsets(&tsk->blocked, &tsk->blocked,
512 sigaddset(&tsk->blocked, sig);
514 spin_unlock_irq(&tsk->sighand->siglock);
518 if (ka->sa.sa_flags & SA_ONESHOT)
519 ka->sa.sa_handler = SIG_DFL;
524 ka->sa.sa_handler = SIG_DFL;
525 force_sig(SIGSEGV, tsk);
529 * Note that 'init' is a special process: it doesn't get signals it doesn't
530 * want to handle. Thus you cannot kill init even with a SIGKILL even by
533 * Note that we go through the signals twice: once to check the signals that
534 * the kernel can handle, and then we build all the user-level signal handling
535 * stack-frames in one go after that.
537 static int do_signal(sigset_t *oldset, struct pt_regs *regs, int syscall)
543 * We want the common case to go fast, which
544 * is why we may in certain cases get here from
545 * kernel mode. Just return without doing anything
548 if (!user_mode(regs))
551 if (current->flags & PF_FREEZE) {
556 if (current->ptrace & PT_SINGLESTEP)
557 ptrace_cancel_bpt(current);
559 signr = get_signal_to_deliver(&info, regs, NULL);
561 handle_signal(signr, &info, oldset, regs, syscall);
562 if (current->ptrace & PT_SINGLESTEP)
563 ptrace_set_bpt(current);
569 * No signal to deliver to the process - restart the syscall.
572 if (regs->ARM_r0 == -ERESTART_RESTARTBLOCK) {
573 if (thumb_mode(regs)) {
574 regs->ARM_r7 = __NR_restart_syscall;
580 usp = (u32 __user *)regs->ARM_sp;
582 put_user(regs->ARM_pc, &usp[0]);
583 /* swi __NR_restart_syscall */
584 put_user(0xef000000 | __NR_restart_syscall, &usp[1]);
585 /* ldr pc, [sp], #12 */
586 put_user(0xe49df00c, &usp[2]);
588 flush_icache_range((unsigned long)usp,
589 (unsigned long)(usp + 3));
591 regs->ARM_pc = regs->ARM_sp + 4;
594 if (regs->ARM_r0 == -ERESTARTNOHAND ||
595 regs->ARM_r0 == -ERESTARTSYS ||
596 regs->ARM_r0 == -ERESTARTNOINTR) {
597 restart_syscall(regs);
600 if (current->ptrace & PT_SINGLESTEP)
601 ptrace_set_bpt(current);
606 do_notify_resume(struct pt_regs *regs, unsigned int thread_flags, int syscall)
608 if (thread_flags & _TIF_SIGPENDING)
609 do_signal(¤t->blocked, regs, syscall);