1 files changed, 118 insertions, 0 deletions

diff --git a/kernel/configs.c b/kernel/configs.c
new file mode 100644
index 000000000000..986f7af31e0a
--- /dev/null
+++ b/kernel/configs.c
@@ -0,0 +1,118 @@
+/*
+ * kernel/configs.c
+ * Echo the kernel .config file used to build the kernel
+ *
+ * Copyright (C) 2002 Khalid Aziz <khalid_aziz@hp.com>
+ * Copyright (C) 2002 Randy Dunlap <rddunlap@osdl.org>
+ * Copyright (C) 2002 Al Stone <ahs3@fc.hp.com>
+ * Copyright (C) 2002 Hewlett-Packard Company
+ *
+ * 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, GOOD TITLE or
+ * NON INFRINGEMENT.  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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/config.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/init.h>
+#include <asm/uaccess.h>
+
+/**************************************************/
+/* the actual current config file                 */
+
+/*
+ * Define kernel_config_data and kernel_config_data_size, which contains the
+ * wrapped and compressed configuration file.  The file is first compressed
+ * with gzip and then bounded by two eight byte magic numbers to allow
+ * extraction from a binary kernel image:
+ *
+ *   IKCFG_ST
+ *   <image>
+ *   IKCFG_ED
+ */
+#define MAGIC_START     "IKCFG_ST"
+#define MAGIC_END       "IKCFG_ED"
+#include "config_data.h"
+
+
+#define MAGIC_SIZE (sizeof(MAGIC_START) - 1)
+#define kernel_config_data_size \
+        (sizeof(kernel_config_data) - 1 - MAGIC_SIZE * 2)
+
+#ifdef CONFIG_IKCONFIG_PROC
+
+/**************************************************/
+/* globals and useful constants                   */
+
+static ssize_t
+ikconfig_read_current(struct file *file, char __user *buf,
+                      size_t len, loff_t * offset)
+{
+        loff_t pos = *offset;
+        ssize_t count;
+
+        if (pos >= kernel_config_data_size)
+                return 0;
+
+        count = min(len, (size_t)(kernel_config_data_size - pos));
+        if (copy_to_user(buf, kernel_config_data + MAGIC_SIZE + pos, count))
+                return -EFAULT;
+
+        *offset += count;
+        return count;
+}
+
+static struct file_operations ikconfig_file_ops = {
+        .owner = THIS_MODULE,
+        .read = ikconfig_read_current,
+};
+
+/***************************************************/
+/* ikconfig_init: start up everything we need to */
+
+static int __init ikconfig_init(void)
+{
+        struct proc_dir_entry *entry;
+
+        /* create the current config file */
+        entry = create_proc_entry("config.gz", S_IFREG | S_IRUGO,
+                                  &proc_root);
+        if (!entry)
+                return -ENOMEM;
+
+        entry->proc_fops = &ikconfig_file_ops;
+        entry->size = kernel_config_data_size;
+
+        return 0;
+}
+
+/***************************************************/
+/* ikconfig_cleanup: clean up our mess           */
+
+static void __exit ikconfig_cleanup(void)
+{
+        remove_proc_entry("config.gz", &proc_root);
+}
+
+module_init(ikconfig_init);
+module_exit(ikconfig_cleanup);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Randy Dunlap");
+MODULE_DESCRIPTION("Echo the kernel .config file used to build the kernel");
+
+#endif /* CONFIG_IKCONFIG_PROC */