The patch titled
Subject: kernel/configs: use .incbin directive to embed config_data.gz
has been added to the -mm tree. Its filename is
kernel-configs-use-incbin-directive-to-embed-config_datagz.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/kernel-configs-use-incbin-directive-to-embed-config_datagz.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/kernel-configs-use-incbin-directive-to-embed-config_datagz.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
Subject: 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.
Link: http://lkml.kernel.org/r/1549941160-8084-1-git-send-email-yamada.masahiro@xxxxxxxxxxxxx
Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Alexander Popov <alex.popov@xxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
Cc: Richard Guy Briggs <rgb@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
Documentation/dontdiff | 1
kernel/.gitignore | 2 -
kernel/Makefile | 11 ----------
kernel/configs.c | 41 ++++++++++++++++++---------------------
4 files changed, 20 insertions(+), 35 deletions(-)
--- a/Documentation/dontdiff~kernel-configs-use-incbin-directive-to-embed-config_datagz
+++ a/Documentation/dontdiff
@@ -106,7 +106,6 @@ compile.h*
conf
config
config-*
-config_data.h*
config.mak
config.mak.autogen
conmakehash
--- a/kernel/configs.c~kernel-configs-use-incbin-directive-to-embed-config_datagz
+++ a/kernel/configs.c
@@ -30,37 +30,34 @@
#include <linux/init.h>
#include <linux/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
+ * "IKCFG_ST" and "IKCFG_ED" are used to extract the config data from
+ * a binary kernel image or a module. See scripts/extract-ikconfig.
*/
-#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)
+asm (
+" .section .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"
+);
#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 + MAGIC_SIZE,
- kernel_config_data_size);
+ &kernel_config_data,
+ &kernel_config_data_end -
+ &kernel_config_data);
}
static const struct file_operations ikconfig_file_ops = {
@@ -79,7 +76,7 @@ static int __init ikconfig_init(void)
if (!entry)
return -ENOMEM;
- proc_set_size(entry, kernel_config_data_size);
+ proc_set_size(entry, &kernel_config_data_end - &kernel_config_data);
return 0;
}
--- a/kernel/.gitignore~kernel-configs-use-incbin-directive-to-embed-config_datagz
+++ a/kernel/.gitignore
@@ -1,7 +1,5 @@
#
# Generated files
#
-config_data.h
-config_data.gz
timeconst.h
hz.bc
--- a/kernel/Makefile~kernel-configs-use-incbin-directive-to-embed-config_datagz
+++ a/kernel/Makefile
@@ -116,17 +116,8 @@ obj-$(CONFIG_GCC_PLUGIN_STACKLEAK) += st
KASAN_SANITIZE_stackleak.o := n
KCOV_INSTRUMENT_stackleak.o := n
-$(obj)/configs.o: $(obj)/config_data.h
+$(obj)/configs.o: $(obj)/config_data.gz
targets += config_data.gz
$(obj)/config_data.gz: $(KCONFIG_CONFIG) FORCE
$(call if_changed,gzip)
-
-filechk_ikconfiggz = \
- echo "static const char kernel_config_data[] __used = MAGIC_START"; \
- cat $< | scripts/bin2c; \
- echo "MAGIC_END;"
-
-targets += config_data.h
-$(obj)/config_data.h: $(obj)/config_data.gz FORCE
- $(call filechk,ikconfiggz)
_
Patches currently in -mm which might be from yamada.masahiro@xxxxxxxxxxxxx are
rename-include-uapi-=-asm-generic-shmparamh-really.patch
linux-kernelh-use-short-to-define-ushrt_max-shrt_max-shrt_min.patch
linux-kernelh-split-_max-and-_min-macros-into-linux-limitsh.patch
kernel-configs-use-incbin-directive-to-embed-config_datagz.patch
