linux-imx

/*

 *  linux/kernel/signal.c

 *

 *  Copyright (C) 1991, 1992  Linus Torvalds

 *

 *  1997-11-02  Modified for POSIX.1b signals by Richard Henderson

 *

 *  2003-06-02  Jim Houston - Concurrent Computer Corp.

 *      Changes to use preallocated sigqueue structures

 *      to allow signals to be sent reliably.

 */

​

#include <linux/slab.h>

#include <linux/export.h>

#include <linux/init.h>

#include <linux/sched/mm.h>

#include <linux/sched/user.h>

#include <linux/sched/debug.h>

#include <linux/sched/task.h>

#include <linux/sched/task_stack.h>

#include <linux/sched/cputime.h>

#include <linux/file.h>

#include <linux/fs.h>

#include <linux/proc_fs.h>

#include <linux/tty.h>

#include <linux/binfmts.h>

#include <linux/coredump.h>

#include <linux/security.h>

#include <linux/syscalls.h>

#include <linux/ptrace.h>

#include <linux/signal.h>

#include <linux/signalfd.h>

#include <linux/ratelimit.h>

#include <linux/tracehook.h>

#include <linux/capability.h>

#include <linux/freezer.h>

#include <linux/pid_namespace.h>

#include <linux/nsproxy.h>

#include <linux/user_namespace.h>

#include <linux/uprobes.h>

#include <linux/compat.h>

#include <linux/cn_proc.h>

#include <linux/compiler.h>

#include <linux/posix-timers.h>

#include <linux/livepatch.h>

​

#define CREATE_TRACE_POINTS

#include <trace/events/signal.h>

​

#include <asm/param.h>

#include <linux/uaccess.h>

#include <asm/unistd.h>

#include <asm/siginfo.h>

#include <asm/cacheflush.h>

#include "audit.h"  /* audit_signal_info() */

​

/*

 * SLAB caches for signal bits.

 */

​

static struct kmem_cache *sigqueue_cachep;

​

int print_fatal_signals __read_mostly;

​

static void __user *sig_handler(struct task_struct *t, int sig)

{

    return t->sighand->action[sig - 1].sa.sa_handler;

}

​

static inline bool sig_handler_ignored(void __user *handler, int sig)

{

    /* Is it explicitly or implicitly ignored? */

    return handler == SIG_IGN ||

           (handler == SIG_DFL && sig_kernel_ignore(sig));

}

​

static bool sig_task_ignored(struct task_struct *t, int sig, bool force)

{

    void __user *handler;

​

    handler = sig_handler(t, sig);

​

    /* SIGKILL and SIGSTOP may not be sent to the global init */

    if (unlikely(is_global_init(t) && sig_kernel_only(sig)))

        return true;

​

    if (unlikely(t->signal->flags & SIGNAL_UNKILLABLE) &&

        handler == SIG_DFL && !(force && sig_kernel_only(sig)))

        return true;

​

    return sig_handler_ignored(handler, sig);

}