linux-imx

/*

 *  Kernel Probes (KProbes)

 *  kernel/kprobes.c

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

 *

 * Copyright (C) IBM Corporation, 2002, 2004

 *

 * 2002-Oct Created by Vamsi Krishna S <vamsi_krishna@in.ibm.com> Kernel

 *      Probes initial implementation (includes suggestions from

 *      Rusty Russell).

 * 2004-Aug Updated by Prasanna S Panchamukhi <prasanna@in.ibm.com> with

 *      hlists and exceptions notifier as suggested by Andi Kleen.

 * 2004-July    Suparna Bhattacharya <suparna@in.ibm.com> added jumper probes

 *      interface to access function arguments.

 * 2004-Sep Prasanna S Panchamukhi <prasanna@in.ibm.com> Changed Kprobes

 *      exceptions notifier to be first on the priority list.

 * 2005-May Hien Nguyen <hien@us.ibm.com>, Jim Keniston

 *      <jkenisto@us.ibm.com> and Prasanna S Panchamukhi

 *      <prasanna@in.ibm.com> added function-return probes.

 */

#include <linux/kprobes.h>

#include <linux/hash.h>

#include <linux/init.h>

#include <linux/slab.h>

#include <linux/stddef.h>

#include <linux/export.h>

#include <linux/moduleloader.h>

#include <linux/kallsyms.h>

#include <linux/freezer.h>

#include <linux/seq_file.h>

#include <linux/debugfs.h>

#include <linux/sysctl.h>

#include <linux/kdebug.h>

#include <linux/memory.h>

#include <linux/ftrace.h>

#include <linux/cpu.h>

#include <linux/jump_label.h>

​

#include <asm/sections.h>

#include <asm/cacheflush.h>

#include <asm/errno.h>

#include <linux/uaccess.h>

​

#define KPROBE_HASH_BITS 6

#define KPROBE_TABLE_SIZE (1 << KPROBE_HASH_BITS)

​

​

static int kprobes_initialized;

static struct hlist_head kprobe_table[KPROBE_TABLE_SIZE];

static struct hlist_head kretprobe_inst_table[KPROBE_TABLE_SIZE];

​

/* NOTE: change this value only with kprobe_mutex held */

static bool kprobes_all_disarmed;

​

/* This protects kprobe_table and optimizing_list */

static DEFINE_MUTEX(kprobe_mutex);

static DEFINE_PER_CPU(struct kprobe *, kprobe_instance) = NULL;

static struct {

    raw_spinlock_t lock ____cacheline_aligned_in_smp;

} kretprobe_table_locks[KPROBE_TABLE_SIZE];

​

kprobe_opcode_t * __weak kprobe_lookup_name(const char *name,

                    unsigned int __unused)

{

    return ((kprobe_opcode_t *)(kallsyms_lookup_name(name)));

}

​

static raw_spinlock_t *kretprobe_table_lock_ptr(unsigned long hash)

{

    return &(kretprobe_table_locks[hash].lock);

}

​

/* Blacklist -- list of struct kprobe_blacklist_entry */

static LIST_HEAD(kprobe_blacklist);

​

#ifdef __ARCH_WANT_KPROBES_INSN_SLOT

/*

 * kprobe->ainsn.insn points to the copy of the instruction to be

 * single-stepped. x86_64, POWER4 and above have no-exec support and