540 lines
15 KiB
C
540 lines
15 KiB
C
/*
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* linux/arch/arm26/kernel/signal.c
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*
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* Copyright (C) 1995-2002 Russell King
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* Copyright (C) 2003 Ian Molton (ARM26)
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*
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* FIXME!!! This is probably very broken (13/05/2003)
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/config.h>
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#include <linux/sched.h>
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#include <linux/mm.h>
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#include <linux/smp.h>
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#include <linux/smp_lock.h>
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#include <linux/kernel.h>
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#include <linux/errno.h>
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#include <linux/signal.h>
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#include <linux/wait.h>
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#include <linux/ptrace.h>
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#include <linux/personality.h>
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#include <linux/tty.h>
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#include <linux/binfmts.h>
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#include <linux/elf.h>
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#include <asm/pgalloc.h>
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#include <asm/ucontext.h>
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#include <asm/uaccess.h>
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#include <asm/unistd.h>
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#include "ptrace.h"
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#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
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/*
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* For ARM syscalls, we encode the syscall number into the instruction.
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*/
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#define SWI_SYS_SIGRETURN (0xef000000|(__NR_sigreturn))
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#define SWI_SYS_RT_SIGRETURN (0xef000000|(__NR_rt_sigreturn))
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static int do_signal(sigset_t *oldset, struct pt_regs * regs, int syscall);
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/*
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* atomically swap in the new signal mask, and wait for a signal.
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*/
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asmlinkage int sys_sigsuspend(int restart, unsigned long oldmask, old_sigset_t mask, struct pt_regs *regs)
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{
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sigset_t saveset;
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mask &= _BLOCKABLE;
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spin_lock_irq(¤t->sighand->siglock);
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saveset = current->blocked;
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siginitset(¤t->blocked, mask);
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recalc_sigpending();
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spin_unlock_irq(¤t->sighand->siglock);
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regs->ARM_r0 = -EINTR;
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while (1) {
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current->state = TASK_INTERRUPTIBLE;
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schedule();
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if (do_signal(&saveset, regs, 0))
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return regs->ARM_r0;
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}
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}
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asmlinkage int
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sys_rt_sigsuspend(sigset_t *unewset, size_t sigsetsize, struct pt_regs *regs)
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{
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sigset_t saveset, newset;
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/* XXX: Don't preclude handling different sized sigset_t's. */
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if (sigsetsize != sizeof(sigset_t))
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return -EINVAL;
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if (copy_from_user(&newset, unewset, sizeof(newset)))
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return -EFAULT;
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sigdelsetmask(&newset, ~_BLOCKABLE);
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spin_lock_irq(¤t->sighand->siglock);
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saveset = current->blocked;
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current->blocked = newset;
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recalc_sigpending();
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spin_unlock_irq(¤t->sighand->siglock);
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regs->ARM_r0 = -EINTR;
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while (1) {
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current->state = TASK_INTERRUPTIBLE;
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schedule();
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if (do_signal(&saveset, regs, 0))
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return regs->ARM_r0;
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}
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}
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asmlinkage int
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sys_sigaction(int sig, const struct old_sigaction *act,
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struct old_sigaction *oact)
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{
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struct k_sigaction new_ka, old_ka;
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int ret;
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if (act) {
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old_sigset_t mask;
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if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
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__get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
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__get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
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return -EFAULT;
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__get_user(new_ka.sa.sa_flags, &act->sa_flags);
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__get_user(mask, &act->sa_mask);
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siginitset(&new_ka.sa.sa_mask, mask);
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}
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ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
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if (!ret && oact) {
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if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
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__put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
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__put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
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return -EFAULT;
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__put_user(old_ka.sa.sa_flags, &oact->sa_flags);
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__put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
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}
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return ret;
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}
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/*
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* Do a signal return; undo the signal stack.
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*/
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struct sigframe
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{
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struct sigcontext sc;
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unsigned long extramask[_NSIG_WORDS-1];
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unsigned long retcode;
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};
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struct rt_sigframe
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{
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struct siginfo *pinfo;
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void *puc;
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struct siginfo info;
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struct ucontext uc;
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unsigned long retcode;
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};
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static int
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restore_sigcontext(struct pt_regs *regs, struct sigcontext *sc)
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{
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int err = 0;
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__get_user_error(regs->ARM_r0, &sc->arm_r0, err);
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__get_user_error(regs->ARM_r1, &sc->arm_r1, err);
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__get_user_error(regs->ARM_r2, &sc->arm_r2, err);
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__get_user_error(regs->ARM_r3, &sc->arm_r3, err);
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__get_user_error(regs->ARM_r4, &sc->arm_r4, err);
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__get_user_error(regs->ARM_r5, &sc->arm_r5, err);
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__get_user_error(regs->ARM_r6, &sc->arm_r6, err);
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__get_user_error(regs->ARM_r7, &sc->arm_r7, err);
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__get_user_error(regs->ARM_r8, &sc->arm_r8, err);
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__get_user_error(regs->ARM_r9, &sc->arm_r9, err);
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__get_user_error(regs->ARM_r10, &sc->arm_r10, err);
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__get_user_error(regs->ARM_fp, &sc->arm_fp, err);
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__get_user_error(regs->ARM_ip, &sc->arm_ip, err);
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__get_user_error(regs->ARM_sp, &sc->arm_sp, err);
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__get_user_error(regs->ARM_lr, &sc->arm_lr, err);
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__get_user_error(regs->ARM_pc, &sc->arm_pc, err);
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err |= !valid_user_regs(regs);
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return err;
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}
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asmlinkage int sys_sigreturn(struct pt_regs *regs)
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{
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struct sigframe *frame;
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sigset_t set;
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/*
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* Since we stacked the signal on a 64-bit boundary,
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* then 'sp' should be word aligned here. If it's
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* not, then the user is trying to mess with us.
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*/
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if (regs->ARM_sp & 7)
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goto badframe;
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frame = (struct sigframe *)regs->ARM_sp;
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if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
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goto badframe;
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if (__get_user(set.sig[0], &frame->sc.oldmask)
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|| (_NSIG_WORDS > 1
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&& __copy_from_user(&set.sig[1], &frame->extramask,
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sizeof(frame->extramask))))
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goto badframe;
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sigdelsetmask(&set, ~_BLOCKABLE);
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spin_lock_irq(¤t->sighand->siglock);
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current->blocked = set;
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recalc_sigpending();
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spin_unlock_irq(¤t->sighand->siglock);
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if (restore_sigcontext(regs, &frame->sc))
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goto badframe;
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/* Send SIGTRAP if we're single-stepping */
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if (current->ptrace & PT_SINGLESTEP) {
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ptrace_cancel_bpt(current);
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send_sig(SIGTRAP, current, 1);
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}
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return regs->ARM_r0;
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badframe:
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force_sig(SIGSEGV, current);
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return 0;
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}
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asmlinkage int sys_rt_sigreturn(struct pt_regs *regs)
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{
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struct rt_sigframe *frame;
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sigset_t set;
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/*
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* Since we stacked the signal on a 64-bit boundary,
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* then 'sp' should be word aligned here. If it's
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* not, then the user is trying to mess with us.
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*/
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if (regs->ARM_sp & 7)
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goto badframe;
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frame = (struct rt_sigframe *)regs->ARM_sp;
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if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
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goto badframe;
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if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
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goto badframe;
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sigdelsetmask(&set, ~_BLOCKABLE);
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spin_lock_irq(¤t->sighand->siglock);
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current->blocked = set;
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recalc_sigpending();
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spin_unlock_irq(¤t->sighand->siglock);
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if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
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goto badframe;
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/* Send SIGTRAP if we're single-stepping */
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if (current->ptrace & PT_SINGLESTEP) {
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ptrace_cancel_bpt(current);
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send_sig(SIGTRAP, current, 1);
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}
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return regs->ARM_r0;
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badframe:
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force_sig(SIGSEGV, current);
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return 0;
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}
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static int
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setup_sigcontext(struct sigcontext *sc, /*struct _fpstate *fpstate,*/
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struct pt_regs *regs, unsigned long mask)
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{
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int err = 0;
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__put_user_error(regs->ARM_r0, &sc->arm_r0, err);
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__put_user_error(regs->ARM_r1, &sc->arm_r1, err);
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__put_user_error(regs->ARM_r2, &sc->arm_r2, err);
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__put_user_error(regs->ARM_r3, &sc->arm_r3, err);
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__put_user_error(regs->ARM_r4, &sc->arm_r4, err);
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__put_user_error(regs->ARM_r5, &sc->arm_r5, err);
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__put_user_error(regs->ARM_r6, &sc->arm_r6, err);
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__put_user_error(regs->ARM_r7, &sc->arm_r7, err);
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__put_user_error(regs->ARM_r8, &sc->arm_r8, err);
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__put_user_error(regs->ARM_r9, &sc->arm_r9, err);
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__put_user_error(regs->ARM_r10, &sc->arm_r10, err);
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__put_user_error(regs->ARM_fp, &sc->arm_fp, err);
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__put_user_error(regs->ARM_ip, &sc->arm_ip, err);
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__put_user_error(regs->ARM_sp, &sc->arm_sp, err);
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__put_user_error(regs->ARM_lr, &sc->arm_lr, err);
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__put_user_error(regs->ARM_pc, &sc->arm_pc, err);
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__put_user_error(current->thread.trap_no, &sc->trap_no, err);
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__put_user_error(current->thread.error_code, &sc->error_code, err);
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__put_user_error(current->thread.address, &sc->fault_address, err);
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__put_user_error(mask, &sc->oldmask, err);
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return err;
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}
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static inline void *
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get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, int framesize)
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{
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unsigned long sp = regs->ARM_sp;
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/*
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* This is the X/Open sanctioned signal stack switching.
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*/
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if ((ka->sa.sa_flags & SA_ONSTACK) && !sas_ss_flags(sp))
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sp = current->sas_ss_sp + current->sas_ss_size;
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/*
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* ATPCS B01 mandates 8-byte alignment
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*/
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return (void *)((sp - framesize) & ~7);
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}
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static int
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setup_return(struct pt_regs *regs, struct k_sigaction *ka,
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unsigned long *rc, void *frame, int usig)
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{
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unsigned long handler = (unsigned long)ka->sa.sa_handler;
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unsigned long retcode;
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if (ka->sa.sa_flags & SA_RESTORER) {
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retcode = (unsigned long)ka->sa.sa_restorer;
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} else {
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if (__put_user((ka->sa.sa_flags & SA_SIGINFO)?SWI_SYS_RT_SIGRETURN:SWI_SYS_SIGRETURN, rc))
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return 1;
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retcode = ((unsigned long)rc);
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}
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regs->ARM_r0 = usig;
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regs->ARM_sp = (unsigned long)frame;
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regs->ARM_lr = retcode;
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regs->ARM_pc = handler & ~3;
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return 0;
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}
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static int
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setup_frame(int usig, struct k_sigaction *ka, sigset_t *set, struct pt_regs *regs)
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{
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struct sigframe *frame = get_sigframe(ka, regs, sizeof(*frame));
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int err = 0;
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if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
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return 1;
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err |= setup_sigcontext(&frame->sc, /*&frame->fpstate,*/ regs, set->sig[0]);
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if (_NSIG_WORDS > 1) {
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err |= __copy_to_user(frame->extramask, &set->sig[1],
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sizeof(frame->extramask));
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}
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if (err == 0)
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err = setup_return(regs, ka, &frame->retcode, frame, usig);
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return err;
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}
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static int
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setup_rt_frame(int usig, struct k_sigaction *ka, siginfo_t *info,
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sigset_t *set, struct pt_regs *regs)
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{
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struct rt_sigframe *frame = get_sigframe(ka, regs, sizeof(*frame));
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int err = 0;
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if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
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return 1;
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__put_user_error(&frame->info, &frame->pinfo, err);
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__put_user_error(&frame->uc, &frame->puc, err);
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err |= copy_siginfo_to_user(&frame->info, info);
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/* Clear all the bits of the ucontext we don't use. */
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err |= __clear_user(&frame->uc, offsetof(struct ucontext, uc_mcontext));
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err |= setup_sigcontext(&frame->uc.uc_mcontext, /*&frame->fpstate,*/
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regs, set->sig[0]);
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err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
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if (err == 0)
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err = setup_return(regs, ka, &frame->retcode, frame, usig);
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if (err == 0) {
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/*
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* For realtime signals we must also set the second and third
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* arguments for the signal handler.
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* -- Peter Maydell <pmaydell@chiark.greenend.org.uk> 2000-12-06
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*/
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regs->ARM_r1 = (unsigned long)frame->pinfo;
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regs->ARM_r2 = (unsigned long)frame->puc;
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}
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return err;
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}
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static inline void restart_syscall(struct pt_regs *regs)
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{
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regs->ARM_r0 = regs->ARM_ORIG_r0;
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regs->ARM_pc -= 4;
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}
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/*
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* OK, we're invoking a handler
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*/
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static void
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handle_signal(unsigned long sig, siginfo_t *info, sigset_t *oldset,
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struct pt_regs * regs, int syscall)
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{
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struct thread_info *thread = current_thread_info();
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struct task_struct *tsk = current;
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struct k_sigaction *ka = &tsk->sighand->action[sig-1];
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int usig = sig;
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int ret;
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/*
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* If we were from a system call, check for system call restarting...
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*/
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if (syscall) {
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switch (regs->ARM_r0) {
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case -ERESTART_RESTARTBLOCK:
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current_thread_info()->restart_block.fn =
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do_no_restart_syscall;
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case -ERESTARTNOHAND:
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regs->ARM_r0 = -EINTR;
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break;
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case -ERESTARTSYS:
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if (!(ka->sa.sa_flags & SA_RESTART)) {
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regs->ARM_r0 = -EINTR;
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break;
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}
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/* fallthrough */
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case -ERESTARTNOINTR:
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restart_syscall(regs);
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}
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}
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/*
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* translate the signal
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*/
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if (usig < 32 && thread->exec_domain && thread->exec_domain->signal_invmap)
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usig = thread->exec_domain->signal_invmap[usig];
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/*
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* Set up the stack frame
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*/
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if (ka->sa.sa_flags & SA_SIGINFO)
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ret = setup_rt_frame(usig, ka, info, oldset, regs);
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else
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ret = setup_frame(usig, ka, oldset, regs);
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/*
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* Check that the resulting registers are actually sane.
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*/
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ret |= !valid_user_regs(regs);
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if (ret == 0) {
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if (ka->sa.sa_flags & SA_ONESHOT)
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ka->sa.sa_handler = SIG_DFL;
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spin_lock_irq(&tsk->sighand->siglock);
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sigorsets(&tsk->blocked, &tsk->blocked,
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&ka->sa.sa_mask);
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if (!(ka->sa.sa_flags & SA_NODEFER))
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sigaddset(&tsk->blocked, sig);
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recalc_sigpending();
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spin_unlock_irq(&tsk->sighand->siglock);
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return;
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}
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force_sigsegv(sig, tsk);
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}
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/*
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* Note that 'init' is a special process: it doesn't get signals it doesn't
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* want to handle. Thus you cannot kill init even with a SIGKILL even by
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* mistake.
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*
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* Note that we go through the signals twice: once to check the signals that
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* the kernel can handle, and then we build all the user-level signal handling
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* stack-frames in one go after that.
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*/
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static int do_signal(sigset_t *oldset, struct pt_regs *regs, int syscall)
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{
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siginfo_t info;
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int signr;
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/*
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* We want the common case to go fast, which
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* is why we may in certain cases get here from
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* kernel mode. Just return without doing anything
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* if so.
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*/
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if (!user_mode(regs))
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return 0;
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if (current->ptrace & PT_SINGLESTEP)
|
|
ptrace_cancel_bpt(current);
|
|
|
|
signr = get_signal_to_deliver(&info, regs, NULL);
|
|
if (signr > 0) {
|
|
handle_signal(signr, &info, oldset, regs, syscall);
|
|
if (current->ptrace & PT_SINGLESTEP)
|
|
ptrace_set_bpt(current);
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* No signal to deliver to the process - restart the syscall.
|
|
*/
|
|
if (syscall) {
|
|
if (regs->ARM_r0 == -ERESTART_RESTARTBLOCK) {
|
|
u32 *usp;
|
|
|
|
regs->ARM_sp -= 12;
|
|
usp = (u32 *)regs->ARM_sp;
|
|
|
|
put_user(regs->ARM_pc, &usp[0]);
|
|
/* swi __NR_restart_syscall */
|
|
put_user(0xef000000 | __NR_restart_syscall, &usp[1]);
|
|
/* ldr pc, [sp], #12 */
|
|
// FIXME!!! is #12 correct there?
|
|
put_user(0xe49df00c, &usp[2]);
|
|
|
|
regs->ARM_pc = regs->ARM_sp + 4;
|
|
}
|
|
if (regs->ARM_r0 == -ERESTARTNOHAND ||
|
|
regs->ARM_r0 == -ERESTARTSYS ||
|
|
regs->ARM_r0 == -ERESTARTNOINTR) {
|
|
restart_syscall(regs);
|
|
}
|
|
}
|
|
if (current->ptrace & PT_SINGLESTEP)
|
|
ptrace_set_bpt(current);
|
|
return 0;
|
|
}
|
|
|
|
asmlinkage void
|
|
do_notify_resume(struct pt_regs *regs, unsigned int thread_flags, int syscall)
|
|
{
|
|
if (thread_flags & _TIF_SIGPENDING)
|
|
do_signal(¤t->blocked, regs, syscall);
|
|
}
|