From 13610aa908dcfce77135bb799c0a10d0172da6ba Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Thu, 7 Mar 2019 16:29:53 -0800 Subject: [PATCH] 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 Cc: Randy Dunlap Cc: Arnd Bergmann Cc: Alexander Popov Cc: Kees Cook Cc: Jonathan Corbet Cc: Thomas Gleixner Cc: Dan Williams Cc: Mathieu Desnoyers Cc: Richard Guy Briggs Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/dontdiff | 1 - kernel/.gitignore | 2 -- kernel/Makefile | 11 +---------- kernel/configs.c | 42 ++++++++++++++++++++---------------------- 4 files changed, 21 insertions(+), 35 deletions(-) diff --git a/Documentation/dontdiff b/Documentation/dontdiff index 2228fcc8e29f40..ef25a066d9525a 100644 --- a/Documentation/dontdiff +++ b/Documentation/dontdiff @@ -106,7 +106,6 @@ compile.h* conf config config-* -config_data.h* config.mak config.mak.autogen conmakehash diff --git a/kernel/.gitignore b/kernel/.gitignore index b3097bde4e9cbc..6e699100872fec 100644 --- a/kernel/.gitignore +++ b/kernel/.gitignore @@ -1,7 +1,5 @@ # # Generated files # -config_data.h -config_data.gz timeconst.h hz.bc diff --git a/kernel/Makefile b/kernel/Makefile index 6aa7543bcdb2de..6c57e78817dada 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -116,17 +116,8 @@ obj-$(CONFIG_GCC_PLUGIN_STACKLEAK) += stackleak.o KASAN_SANITIZE_stackleak.o := n KCOV_INSTRUMENT_stackleak.o := n -$(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) diff --git a/kernel/configs.c b/kernel/configs.c index 2df132b2021712..b062425ccf8da3 100644 --- a/kernel/configs.c +++ b/kernel/configs.c @@ -30,37 +30,35 @@ #include #include -/**************************************************/ -/* 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 - * - * 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 ( +" .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 + 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 +77,7 @@ 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; }