| 123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102 |
- From b14784e7883390c20ed3ff904892255404a5914b Mon Sep 17 00:00:00 2001
- From: Felix Fietkau <[email protected]>
- Date: Fri, 7 Jul 2017 17:05:53 +0200
- Subject: add an optional config option for stripping all unnecessary symbol exports from the kernel image
- lede-commit: bb5a40c64b7c4f4848509fa0a6625055fc9e66cc
- Signed-off-by: Felix Fietkau <[email protected]>
- ---
- include/asm-generic/vmlinux.lds.h | 18 +++++++++++++++---
- include/linux/export.h | 9 ++++++++-
- scripts/Makefile.build | 2 +-
- 3 files changed, 24 insertions(+), 5 deletions(-)
- --- a/include/asm-generic/vmlinux.lds.h
- +++ b/include/asm-generic/vmlinux.lds.h
- @@ -81,6 +81,16 @@
- #define RO_EXCEPTION_TABLE
- #endif
-
- +#ifndef SYMTAB_KEEP
- +#define SYMTAB_KEEP KEEP(*(SORT(___ksymtab+*)))
- +#define SYMTAB_KEEP_GPL KEEP(*(SORT(___ksymtab_gpl+*)))
- +#endif
- +
- +#ifndef SYMTAB_DISCARD
- +#define SYMTAB_DISCARD
- +#define SYMTAB_DISCARD_GPL
- +#endif
- +
- /* Align . function alignment. */
- #define ALIGN_FUNCTION() . = ALIGN(CONFIG_FUNCTION_ALIGNMENT)
-
- @@ -486,14 +496,14 @@
- /* Kernel symbol table: Normal symbols */ \
- __ksymtab : AT(ADDR(__ksymtab) - LOAD_OFFSET) { \
- __start___ksymtab = .; \
- - KEEP(*(SORT(___ksymtab+*))) \
- + SYMTAB_KEEP \
- __stop___ksymtab = .; \
- } \
- \
- /* Kernel symbol table: GPL-only symbols */ \
- __ksymtab_gpl : AT(ADDR(__ksymtab_gpl) - LOAD_OFFSET) { \
- __start___ksymtab_gpl = .; \
- - KEEP(*(SORT(___ksymtab_gpl+*))) \
- + SYMTAB_KEEP_GPL \
- __stop___ksymtab_gpl = .; \
- } \
- \
- @@ -513,7 +523,7 @@
- \
- /* Kernel symbol table: strings */ \
- __ksymtab_strings : AT(ADDR(__ksymtab_strings) - LOAD_OFFSET) { \
- - *(__ksymtab_strings) \
- + *(__ksymtab_strings+*) \
- } \
- \
- /* __*init sections */ \
- @@ -1000,6 +1010,8 @@
- #define COMMON_DISCARDS \
- SANITIZER_DISCARDS \
- PATCHABLE_DISCARDS \
- + SYMTAB_DISCARD \
- + SYMTAB_DISCARD_GPL \
- *(.discard) \
- *(.discard.*) \
- *(.export_symbol) \
- --- a/include/linux/export-internal.h
- +++ b/include/linux/export-internal.h
- @@ -26,6 +26,12 @@
- #define __KSYM_REF(sym) ".long " #sym
- #endif
-
- +#ifdef MODULE
- +#define __EXPORT_SUFFIX(sym)
- +#else
- +#define __EXPORT_SUFFIX(sym) "+" #sym
- +#endif
- +
- /*
- * For every exported symbol, do the following:
- *
- @@ -38,7 +44,7 @@
- * former apparently works on all arches according to the binutils source.
- */
- #define __KSYMTAB(name, sym, sec, ns) \
- - asm(" .section \"__ksymtab_strings\",\"aMS\",%progbits,1" "\n" \
- + asm(" .section \"__ksymtab_strings" __EXPORT_SUFFIX(sym) "\",\"aMS\",%progbits,1" "\n" \
- "__kstrtab_" #name ":" "\n" \
- " .asciz \"" #name "\"" "\n" \
- "__kstrtabns_" #name ":" "\n" \
- --- a/scripts/Makefile.build
- +++ b/scripts/Makefile.build
- @@ -366,7 +366,7 @@ targets += $(real-dtb-y) $(lib-y) $(alwa
- # Linker scripts preprocessor (.lds.S -> .lds)
- # ---------------------------------------------------------------------------
- quiet_cmd_cpp_lds_S = LDS $@
- - cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -U$(ARCH) \
- + cmd_cpp_lds_S = $(CPP) $(EXTRA_LDSFLAGS) $(cpp_flags) -P -U$(ARCH) \
- -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
-
- $(obj)/%.lds: $(src)/%.lds.S FORCE
|
