kernel_optimize_test/kernel/configs.c
Masahiro Yamada 13610aa908 kernel/configs: use .incbin directive to embed config_data.gz
This slightly optimizes the kernel/configs.c build.

bin2c is not very efficient because it converts a data file into a huge
array to embed it into a *.c file.

Instead, we can use the .incbin directive.

Also, this simplifies the code; Makefile is cleaner, and the way to get
the offset/size of the config_data.gz is more straightforward.

I used the "asm" statement in *.c instead of splitting it into *.S
because MODULE_* tags are not supported in *.S files.

I also cleaned up kernel/.gitignore; "config_data.gz" is unneeded
because the top-level .gitignore takes care of the "*.gz" pattern.

[yamada.masahiro@socionext.com: v2]
  Link: http://lkml.kernel.org/r/1550108893-21226-1-git-send-email-yamada.masahiro@socionext.com
Link: http://lkml.kernel.org/r/1549941160-8084-1-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Alexander Popov <alex.popov@linux.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-07 18:32:02 -08:00

98 lines
2.7 KiB
C

/*
* 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 <rdunlap@xenotime.net>
* 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/kernel.h>
#include <linux/module.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/init.h>
#include <linux/uaccess.h>
/*
* "IKCFG_ST" and "IKCFG_ED" are used to extract the config data from
* a binary kernel image or a module. See scripts/extract-ikconfig.
*/
asm (
" .pushsection .rodata, \"a\" \n"
" .ascii \"IKCFG_ST\" \n"
" .global kernel_config_data \n"
"kernel_config_data: \n"
" .incbin \"kernel/config_data.gz\" \n"
" .global kernel_config_data_end \n"
"kernel_config_data_end: \n"
" .ascii \"IKCFG_ED\" \n"
" .popsection \n"
);
#ifdef CONFIG_IKCONFIG_PROC
extern char kernel_config_data;
extern char kernel_config_data_end;
static ssize_t
ikconfig_read_current(struct file *file, char __user *buf,
size_t len, loff_t * offset)
{
return simple_read_from_buffer(buf, len, offset,
&kernel_config_data,
&kernel_config_data_end -
&kernel_config_data);
}
static const struct file_operations ikconfig_file_ops = {
.owner = THIS_MODULE,
.read = ikconfig_read_current,
.llseek = default_llseek,
};
static int __init ikconfig_init(void)
{
struct proc_dir_entry *entry;
/* create the current config file */
entry = proc_create("config.gz", S_IFREG | S_IRUGO, NULL,
&ikconfig_file_ops);
if (!entry)
return -ENOMEM;
proc_set_size(entry, &kernel_config_data_end - &kernel_config_data);
return 0;
}
static void __exit ikconfig_cleanup(void)
{
remove_proc_entry("config.gz", NULL);
}
module_init(ikconfig_init);
module_exit(ikconfig_cleanup);
#endif /* CONFIG_IKCONFIG_PROC */
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Randy Dunlap");
MODULE_DESCRIPTION("Echo the kernel .config file used to build the kernel");