add an optional config option for stripping all unnecessary symbol exports from the kernel image
SVN-Revision: 17181
This commit is contained in:
Felix Fietkau
@@ -134,6 +134,14 @@ config USE_MKLIBS
|
|||||||
Note that this will make the system libraries incompatible with most of the packages
|
Note that this will make the system libraries incompatible with most of the packages
|
||||||
that are not selected during the build process
|
that are not selected during the build process
|
||||||
|
|
||||||
|
config STRIP_KERNEL_EXPORTS
|
||||||
|
depends LINUX_2_6
|
||||||
|
bool "Strip unnecessary exports from the kernel image"
|
||||||
|
help
|
||||||
|
Reduces kernel size by stripping unused kernel exports from the kernel image
|
||||||
|
Note that this might make the kernel incompatible with any kernel modules that
|
||||||
|
were not selected at the time the kernel image was created
|
||||||
|
|
||||||
comment "Package build options"
|
comment "Package build options"
|
||||||
|
|
||||||
config DEBUG
|
config DEBUG
|
||||||
|
|||||||
@@ -54,6 +54,28 @@ define BuildKernel
|
|||||||
$(Kernel/Prepare)
|
$(Kernel/Prepare)
|
||||||
touch $$@
|
touch $$@
|
||||||
|
|
||||||
|
$(KERNEL_BUILD_DIR)/symtab.txt: FORCE
|
||||||
|
find $(LINUX_DIR) $(STAGING_DIR_ROOT)/lib/modules -name \*.ko | \
|
||||||
|
xargs $(TARGET_CROSS)nm | \
|
||||||
|
awk '$$$$1 == "U" { print $$$$2 } ' | \
|
||||||
|
sort -u > $$@
|
||||||
|
|
||||||
|
$(KERNEL_BUILD_DIR)/symtab.h: $(KERNEL_BUILD_DIR)/symtab.txt
|
||||||
|
( \
|
||||||
|
echo '#define SYMTAB_KEEP \'; \
|
||||||
|
cat $(KERNEL_BUILD_DIR)/symtab.txt | \
|
||||||
|
awk '{print "*(__ksymtab." $$$$1 ") \\" }'; \
|
||||||
|
echo; \
|
||||||
|
echo '#define SYMTAB_KEEP_GPL \'; \
|
||||||
|
cat $(KERNEL_BUILD_DIR)/symtab.txt | \
|
||||||
|
awk '{print "*(__ksymtab_gpl." $$$$1 ") \\" }'; \
|
||||||
|
echo; \
|
||||||
|
echo '#define SYMTAB_KEEP_STR \'; \
|
||||||
|
cat $(KERNEL_BUILD_DIR)/symtab.txt | \
|
||||||
|
awk '{print "*(__ksymtab_strings." $$$$1 ") \\" }'; \
|
||||||
|
echo; \
|
||||||
|
) > $$@
|
||||||
|
|
||||||
$(STAMP_CONFIGURED): $(STAMP_PREPARED) $(LINUX_CONFIG) $(GENERIC_LINUX_CONFIG) $(TOPDIR)/.config
|
$(STAMP_CONFIGURED): $(STAMP_PREPARED) $(LINUX_CONFIG) $(GENERIC_LINUX_CONFIG) $(TOPDIR)/.config
|
||||||
$(Kernel/Configure)
|
$(Kernel/Configure)
|
||||||
touch $$@
|
touch $$@
|
||||||
@@ -62,7 +84,7 @@ define BuildKernel
|
|||||||
$(Kernel/CompileModules)
|
$(Kernel/CompileModules)
|
||||||
touch $$@
|
touch $$@
|
||||||
|
|
||||||
$(LINUX_DIR)/.image: $(STAMP_CONFIGURED) FORCE
|
$(LINUX_DIR)/.image: $(STAMP_CONFIGURED) $(if $(CONFIG_STRIP_KERNEL_EXPORTS),$(KERNEL_BUILD_DIR)/symtab.h) FORCE
|
||||||
$(Kernel/CompileImage)
|
$(Kernel/CompileImage)
|
||||||
touch $$@
|
touch $$@
|
||||||
|
|
||||||
|
|||||||
@@ -22,6 +22,11 @@ KERNEL_MAKEOPTS := -C $(LINUX_DIR) \
|
|||||||
KBUILD_HAVE_NLS=no \
|
KBUILD_HAVE_NLS=no \
|
||||||
CONFIG_SHELL="$(BASH)"
|
CONFIG_SHELL="$(BASH)"
|
||||||
|
|
||||||
|
ifdef CONFIG_STRIP_KERNEL_EXPORTS
|
||||||
|
KERNEL_MAKEOPTS += \
|
||||||
|
EXTRA_LDSFLAGS="-I$(KERNEL_BUILD_DIR) -include symtab.h"
|
||||||
|
endif
|
||||||
|
|
||||||
INITRAMFS_EXTRA_FILES ?= $(GENERIC_PLATFORM_DIR)/image/initramfs-base-files.txt
|
INITRAMFS_EXTRA_FILES ?= $(GENERIC_PLATFORM_DIR)/image/initramfs-base-files.txt
|
||||||
|
|
||||||
ifneq (,$(KERNEL_CC))
|
ifneq (,$(KERNEL_CC))
|
||||||
|
|||||||
117
target/linux/generic-2.6/patches-2.6.28/027-module_exports.patch
Normal file
117
target/linux/generic-2.6/patches-2.6.28/027-module_exports.patch
Normal file
@@ -0,0 +1,117 @@
|
|||||||
|
--- a/Makefile
|
||||||
|
+++ b/Makefile
|
||||||
|
@@ -963,7 +963,7 @@ prepare: prepare0
|
||||||
|
# Leave this as default for preprocessing vmlinux.lds.S, which is now
|
||||||
|
# done in arch/$(ARCH)/kernel/Makefile
|
||||||
|
|
||||||
|
-export CPPFLAGS_vmlinux.lds += -P -C -U$(ARCH)
|
||||||
|
+export CPPFLAGS_vmlinux.lds += -P -C -U$(ARCH) $(EXTRA_LDSFLAGS)
|
||||||
|
|
||||||
|
# The asm symlink changes when $(ARCH) changes.
|
||||||
|
# Detect this and ask user to run make mrproper
|
||||||
|
--- a/include/asm-generic/vmlinux.lds.h
|
||||||
|
+++ b/include/asm-generic/vmlinux.lds.h
|
||||||
|
@@ -2,6 +2,18 @@
|
||||||
|
#define LOAD_OFFSET 0
|
||||||
|
#endif
|
||||||
|
|
||||||
|
+#ifndef SYMTAB_KEEP_STR
|
||||||
|
+#define SYMTAB_KEEP_STR *(__ksymtab_strings.*)
|
||||||
|
+#endif
|
||||||
|
+
|
||||||
|
+#ifndef SYMTAB_KEEP
|
||||||
|
+#define SYMTAB_KEEP *(__ksymtab.*)
|
||||||
|
+#endif
|
||||||
|
+
|
||||||
|
+#ifndef SYMTAB_KEEP_GPL
|
||||||
|
+#define SYMTAB_KEEP_GPL *(__ksymtab_gpl.*)
|
||||||
|
+#endif
|
||||||
|
+
|
||||||
|
#ifndef VMLINUX_SYMBOL
|
||||||
|
#define VMLINUX_SYMBOL(_sym_) _sym_
|
||||||
|
#endif
|
||||||
|
@@ -124,35 +136,35 @@
|
||||||
|
/* Kernel symbol table: Normal symbols */ \
|
||||||
|
__ksymtab : AT(ADDR(__ksymtab) - LOAD_OFFSET) { \
|
||||||
|
VMLINUX_SYMBOL(__start___ksymtab) = .; \
|
||||||
|
- *(__ksymtab) \
|
||||||
|
+ SYMTAB_KEEP \
|
||||||
|
VMLINUX_SYMBOL(__stop___ksymtab) = .; \
|
||||||
|
} \
|
||||||
|
\
|
||||||
|
/* Kernel symbol table: GPL-only symbols */ \
|
||||||
|
__ksymtab_gpl : AT(ADDR(__ksymtab_gpl) - LOAD_OFFSET) { \
|
||||||
|
VMLINUX_SYMBOL(__start___ksymtab_gpl) = .; \
|
||||||
|
- *(__ksymtab_gpl) \
|
||||||
|
+ SYMTAB_KEEP_GPL \
|
||||||
|
VMLINUX_SYMBOL(__stop___ksymtab_gpl) = .; \
|
||||||
|
} \
|
||||||
|
\
|
||||||
|
/* Kernel symbol table: Normal unused symbols */ \
|
||||||
|
__ksymtab_unused : AT(ADDR(__ksymtab_unused) - LOAD_OFFSET) { \
|
||||||
|
VMLINUX_SYMBOL(__start___ksymtab_unused) = .; \
|
||||||
|
- *(__ksymtab_unused) \
|
||||||
|
+ *(__ksymtab_unused.*) \
|
||||||
|
VMLINUX_SYMBOL(__stop___ksymtab_unused) = .; \
|
||||||
|
} \
|
||||||
|
\
|
||||||
|
/* Kernel symbol table: GPL-only unused symbols */ \
|
||||||
|
__ksymtab_unused_gpl : AT(ADDR(__ksymtab_unused_gpl) - LOAD_OFFSET) { \
|
||||||
|
VMLINUX_SYMBOL(__start___ksymtab_unused_gpl) = .; \
|
||||||
|
- *(__ksymtab_unused_gpl) \
|
||||||
|
+ *(__ksymtab_unused_gpl.*) \
|
||||||
|
VMLINUX_SYMBOL(__stop___ksymtab_unused_gpl) = .; \
|
||||||
|
} \
|
||||||
|
\
|
||||||
|
/* Kernel symbol table: GPL-future-only symbols */ \
|
||||||
|
__ksymtab_gpl_future : AT(ADDR(__ksymtab_gpl_future) - LOAD_OFFSET) { \
|
||||||
|
VMLINUX_SYMBOL(__start___ksymtab_gpl_future) = .; \
|
||||||
|
- *(__ksymtab_gpl_future) \
|
||||||
|
+ *(__ksymtab_gpl_future.*) \
|
||||||
|
VMLINUX_SYMBOL(__stop___ksymtab_gpl_future) = .; \
|
||||||
|
} \
|
||||||
|
\
|
||||||
|
@@ -193,7 +205,13 @@
|
||||||
|
\
|
||||||
|
/* Kernel symbol table: strings */ \
|
||||||
|
__ksymtab_strings : AT(ADDR(__ksymtab_strings) - LOAD_OFFSET) { \
|
||||||
|
- *(__ksymtab_strings) \
|
||||||
|
+ SYMTAB_KEEP_STR \
|
||||||
|
+ } \
|
||||||
|
+ \
|
||||||
|
+ /DISCARD/ : { \
|
||||||
|
+ *(__ksymtab.*) \
|
||||||
|
+ *(__ksymtab_gpl.*) \
|
||||||
|
+ *(__ksymtab_strings.*) \
|
||||||
|
} \
|
||||||
|
\
|
||||||
|
/* __*init sections */ \
|
||||||
|
--- a/include/linux/module.h
|
||||||
|
+++ b/include/linux/module.h
|
||||||
|
@@ -187,16 +187,24 @@ void *__symbol_get_gpl(const char *symbo
|
||||||
|
#define __CRC_SYMBOL(sym, sec)
|
||||||
|
#endif
|
||||||
|
|
||||||
|
+#ifdef MODULE
|
||||||
|
+#define __EXPORT_SUFFIX(sym)
|
||||||
|
+#else
|
||||||
|
+#define __EXPORT_SUFFIX(sym) "." #sym
|
||||||
|
+#endif
|
||||||
|
+
|
||||||
|
/* For every exported symbol, place a struct in the __ksymtab section */
|
||||||
|
#define __EXPORT_SYMBOL(sym, sec) \
|
||||||
|
extern typeof(sym) sym; \
|
||||||
|
__CRC_SYMBOL(sym, sec) \
|
||||||
|
static const char __kstrtab_##sym[] \
|
||||||
|
- __attribute__((section("__ksymtab_strings"), aligned(1))) \
|
||||||
|
+ __attribute__((section("__ksymtab_strings" \
|
||||||
|
+ __EXPORT_SUFFIX(sym)), aligned(1))) \
|
||||||
|
= MODULE_SYMBOL_PREFIX #sym; \
|
||||||
|
static const struct kernel_symbol __ksymtab_##sym \
|
||||||
|
__used \
|
||||||
|
- __attribute__((section("__ksymtab" sec), unused)) \
|
||||||
|
+ __attribute__((section("__ksymtab" sec \
|
||||||
|
+ __EXPORT_SUFFIX(sym)), unused)) \
|
||||||
|
= { (unsigned long)&sym, __kstrtab_##sym }
|
||||||
|
|
||||||
|
#define EXPORT_SYMBOL(sym) \
|
||||||
117
target/linux/generic-2.6/patches-2.6.30/028-module_exports.patch
Normal file
117
target/linux/generic-2.6/patches-2.6.30/028-module_exports.patch
Normal file
@@ -0,0 +1,117 @@
|
|||||||
|
--- a/include/asm-generic/vmlinux.lds.h
|
||||||
|
+++ b/include/asm-generic/vmlinux.lds.h
|
||||||
|
@@ -4,6 +4,18 @@
|
||||||
|
#define LOAD_OFFSET 0
|
||||||
|
#endif
|
||||||
|
|
||||||
|
+#ifndef SYMTAB_KEEP_STR
|
||||||
|
+#define SYMTAB_KEEP_STR *(__ksymtab_strings.*)
|
||||||
|
+#endif
|
||||||
|
+
|
||||||
|
+#ifndef SYMTAB_KEEP
|
||||||
|
+#define SYMTAB_KEEP *(__ksymtab.*)
|
||||||
|
+#endif
|
||||||
|
+
|
||||||
|
+#ifndef SYMTAB_KEEP_GPL
|
||||||
|
+#define SYMTAB_KEEP_GPL *(__ksymtab_gpl.*)
|
||||||
|
+#endif
|
||||||
|
+
|
||||||
|
#ifndef VMLINUX_SYMBOL
|
||||||
|
#define VMLINUX_SYMBOL(_sym_) _sym_
|
||||||
|
#endif
|
||||||
|
@@ -176,35 +188,35 @@
|
||||||
|
/* Kernel symbol table: Normal symbols */ \
|
||||||
|
__ksymtab : AT(ADDR(__ksymtab) - LOAD_OFFSET) { \
|
||||||
|
VMLINUX_SYMBOL(__start___ksymtab) = .; \
|
||||||
|
- *(__ksymtab) \
|
||||||
|
+ SYMTAB_KEEP \
|
||||||
|
VMLINUX_SYMBOL(__stop___ksymtab) = .; \
|
||||||
|
} \
|
||||||
|
\
|
||||||
|
/* Kernel symbol table: GPL-only symbols */ \
|
||||||
|
__ksymtab_gpl : AT(ADDR(__ksymtab_gpl) - LOAD_OFFSET) { \
|
||||||
|
VMLINUX_SYMBOL(__start___ksymtab_gpl) = .; \
|
||||||
|
- *(__ksymtab_gpl) \
|
||||||
|
+ SYMTAB_KEEP_GPL \
|
||||||
|
VMLINUX_SYMBOL(__stop___ksymtab_gpl) = .; \
|
||||||
|
} \
|
||||||
|
\
|
||||||
|
/* Kernel symbol table: Normal unused symbols */ \
|
||||||
|
__ksymtab_unused : AT(ADDR(__ksymtab_unused) - LOAD_OFFSET) { \
|
||||||
|
VMLINUX_SYMBOL(__start___ksymtab_unused) = .; \
|
||||||
|
- *(__ksymtab_unused) \
|
||||||
|
+ *(__ksymtab_unused.*) \
|
||||||
|
VMLINUX_SYMBOL(__stop___ksymtab_unused) = .; \
|
||||||
|
} \
|
||||||
|
\
|
||||||
|
/* Kernel symbol table: GPL-only unused symbols */ \
|
||||||
|
__ksymtab_unused_gpl : AT(ADDR(__ksymtab_unused_gpl) - LOAD_OFFSET) { \
|
||||||
|
VMLINUX_SYMBOL(__start___ksymtab_unused_gpl) = .; \
|
||||||
|
- *(__ksymtab_unused_gpl) \
|
||||||
|
+ *(__ksymtab_unused_gpl.*) \
|
||||||
|
VMLINUX_SYMBOL(__stop___ksymtab_unused_gpl) = .; \
|
||||||
|
} \
|
||||||
|
\
|
||||||
|
/* Kernel symbol table: GPL-future-only symbols */ \
|
||||||
|
__ksymtab_gpl_future : AT(ADDR(__ksymtab_gpl_future) - LOAD_OFFSET) { \
|
||||||
|
VMLINUX_SYMBOL(__start___ksymtab_gpl_future) = .; \
|
||||||
|
- *(__ksymtab_gpl_future) \
|
||||||
|
+ *(__ksymtab_gpl_future.*) \
|
||||||
|
VMLINUX_SYMBOL(__stop___ksymtab_gpl_future) = .; \
|
||||||
|
} \
|
||||||
|
\
|
||||||
|
@@ -245,7 +257,13 @@
|
||||||
|
\
|
||||||
|
/* Kernel symbol table: strings */ \
|
||||||
|
__ksymtab_strings : AT(ADDR(__ksymtab_strings) - LOAD_OFFSET) { \
|
||||||
|
- *(__ksymtab_strings) \
|
||||||
|
+ SYMTAB_KEEP_STR \
|
||||||
|
+ } \
|
||||||
|
+ \
|
||||||
|
+ /DISCARD/ : { \
|
||||||
|
+ *(__ksymtab.*) \
|
||||||
|
+ *(__ksymtab_gpl.*) \
|
||||||
|
+ *(__ksymtab_strings.*) \
|
||||||
|
} \
|
||||||
|
\
|
||||||
|
/* __*init sections */ \
|
||||||
|
--- a/include/linux/module.h
|
||||||
|
+++ b/include/linux/module.h
|
||||||
|
@@ -187,16 +187,24 @@ void *__symbol_get_gpl(const char *symbo
|
||||||
|
#define __CRC_SYMBOL(sym, sec)
|
||||||
|
#endif
|
||||||
|
|
||||||
|
+#ifdef MODULE
|
||||||
|
+#define __EXPORT_SUFFIX(sym)
|
||||||
|
+#else
|
||||||
|
+#define __EXPORT_SUFFIX(sym) "." #sym
|
||||||
|
+#endif
|
||||||
|
+
|
||||||
|
/* For every exported symbol, place a struct in the __ksymtab section */
|
||||||
|
#define __EXPORT_SYMBOL(sym, sec) \
|
||||||
|
extern typeof(sym) sym; \
|
||||||
|
__CRC_SYMBOL(sym, sec) \
|
||||||
|
static const char __kstrtab_##sym[] \
|
||||||
|
- __attribute__((section("__ksymtab_strings"), aligned(1))) \
|
||||||
|
+ __attribute__((section("__ksymtab_strings" \
|
||||||
|
+ __EXPORT_SUFFIX(sym)), aligned(1))) \
|
||||||
|
= MODULE_SYMBOL_PREFIX #sym; \
|
||||||
|
static const struct kernel_symbol __ksymtab_##sym \
|
||||||
|
__used \
|
||||||
|
- __attribute__((section("__ksymtab" sec), unused)) \
|
||||||
|
+ __attribute__((section("__ksymtab" sec \
|
||||||
|
+ __EXPORT_SUFFIX(sym)), unused)) \
|
||||||
|
= { (unsigned long)&sym, __kstrtab_##sym }
|
||||||
|
|
||||||
|
#define EXPORT_SYMBOL(sym) \
|
||||||
|
--- a/Makefile
|
||||||
|
+++ b/Makefile
|
||||||
|
@@ -994,7 +994,7 @@ prepare: prepare0
|
||||||
|
# Leave this as default for preprocessing vmlinux.lds.S, which is now
|
||||||
|
# done in arch/$(ARCH)/kernel/Makefile
|
||||||
|
|
||||||
|
-export CPPFLAGS_vmlinux.lds += -P -C -U$(ARCH)
|
||||||
|
+export CPPFLAGS_vmlinux.lds += -P -C -U$(ARCH) $(EXTRA_LDSFLAGS)
|
||||||
|
|
||||||
|
# The asm symlink changes when $(ARCH) changes.
|
||||||
|
# Detect this and ask user to run make mrproper
|
||||||
Reference in New Issue
Block a user