diff options
| author | Ard Biesheuvel <[email protected]> | 2018-08-21 21:56:04 -0700 |
|---|---|---|
| committer | Linus Torvalds <[email protected]> | 2018-08-22 10:52:47 -0700 |
| commit | f922c4abdf7648523589abee9460c87f51630d2f (patch) | |
| tree | ed5e77b7ac6360b2f505061fe180bfebcea05321 | |
| parent | 271ca788774aaef9ca4c372573122cc4548cd401 (diff) | |
module: allow symbol exports to be disabled
To allow existing C code to be incorporated into the decompressor or the
UEFI stub, introduce a CPP macro that turns all EXPORT_SYMBOL_xxx
declarations into nops, and #define it in places where such exports are
undesirable. Note that this gets rid of a rather dodgy redefine of
linux/export.h's header guard.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ard Biesheuvel <[email protected]>
Acked-by: Nicolas Pitre <[email protected]>
Acked-by: Michael Ellerman <[email protected]>
Reviewed-by: Will Deacon <[email protected]>
Acked-by: Ingo Molnar <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Bjorn Helgaas <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: James Morris <[email protected]>
Cc: James Morris <[email protected]>
Cc: Jessica Yu <[email protected]>
Cc: Josh Poimboeuf <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Petr Mladek <[email protected]>
Cc: Russell King <[email protected]>
Cc: "Serge E. Hallyn" <[email protected]>
Cc: Sergey Senozhatsky <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Thomas Garnier <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
| -rw-r--r-- | arch/x86/boot/compressed/kaslr.c | 5 | ||||
| -rw-r--r-- | drivers/firmware/efi/libstub/Makefile | 1 | ||||
| -rw-r--r-- | include/linux/export.h | 11 |
3 files changed, 12 insertions, 5 deletions
diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c index 302517929932..d1e19f358b6e 100644 --- a/arch/x86/boot/compressed/kaslr.c +++ b/arch/x86/boot/compressed/kaslr.c @@ -23,11 +23,8 @@ * _ctype[] in lib/ctype.c is needed by isspace() of linux/ctype.h. * While both lib/ctype.c and lib/cmdline.c will bring EXPORT_SYMBOL * which is meaningless and will cause compiling error in some cases. - * So do not include linux/export.h and define EXPORT_SYMBOL(sym) - * as empty. */ -#define _LINUX_EXPORT_H -#define EXPORT_SYMBOL(sym) +#define __DISABLE_EXPORTS #include "misc.h" #include "error.h" diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile index 88c322d7c71e..14c40a7750d1 100644 --- a/drivers/firmware/efi/libstub/Makefile +++ b/drivers/firmware/efi/libstub/Makefile @@ -24,6 +24,7 @@ KBUILD_CFLAGS := $(cflags-y) -DDISABLE_BRANCH_PROFILING \ -D__NO_FORTIFY \ $(call cc-option,-ffreestanding) \ $(call cc-option,-fno-stack-protector) \ + -D__DISABLE_EXPORTS GCOV_PROFILE := n KASAN_SANITIZE := n diff --git a/include/linux/export.h b/include/linux/export.h index b768d6dd3c90..ea7df303d68d 100644 --- a/include/linux/export.h +++ b/include/linux/export.h @@ -66,7 +66,16 @@ extern struct module __this_module; __attribute__((section("___ksymtab" sec "+" #sym), used)) \ = { (unsigned long)&sym, __kstrtab_##sym } -#if defined(__KSYM_DEPS__) +#if defined(__DISABLE_EXPORTS) + +/* + * Allow symbol exports to be disabled completely so that C code may + * be reused in other execution contexts such as the UEFI stub or the + * decompressor. + */ +#define __EXPORT_SYMBOL(sym, sec) + +#elif defined(__KSYM_DEPS__) /* * For fine grained build dependencies, we want to tell the build system |