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| author | Nicolas Pitre <nicolas.pitre@linaro.org> | 2016-01-22 01:32:26 -0500 |
|---|---|---|
| committer | Nicolas Pitre <nicolas.pitre@linaro.org> | 2016-03-29 16:18:53 -0400 |
| commit | f235541699bcf14fb8be797c6bc1d7106df0eb64 (patch) | |
| tree | 6707edc556076ba677ca4fbb68054bbe128857af /include/linux/export.h | |
| parent | 9895c03d48115c7783c0ef0a591447d53254ef84 (diff) | |
| download | lwn-f235541699bcf14fb8be797c6bc1d7106df0eb64.tar.gz lwn-f235541699bcf14fb8be797c6bc1d7106df0eb64.zip | |
export.h: allow for per-symbol configurable EXPORT_SYMBOL()
Similar to include/generated/autoconf.h, include/generated/autoksyms.h
will contain a list of defines for each EXPORT_SYMBOL() that we want
active. The format is:
#define __KSYM_<symbol_name> 1
This list will be auto-generated with another patch. For now we only
include the preprocessor magic to automatically create or omit the
corresponding struct kernel_symbol declaration.
Given the content of include/generated/autoksyms.h may not be known in
advance, an empty file is created early on to let the build proceed.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Diffstat (limited to 'include/linux/export.h')
| -rw-r--r-- | include/linux/export.h | 22 |
1 files changed, 20 insertions, 2 deletions
diff --git a/include/linux/export.h b/include/linux/export.h index 96e45ea463e7..77afdb2a2506 100644 --- a/include/linux/export.h +++ b/include/linux/export.h @@ -38,7 +38,7 @@ extern struct module __this_module; #ifdef CONFIG_MODULES -#ifndef __GENKSYMS__ +#if defined(__KERNEL__) && !defined(__GENKSYMS__) #ifdef CONFIG_MODVERSIONS /* Mark the CRC weak since genksyms apparently decides not to * generate a checksums for some symbols */ @@ -53,7 +53,7 @@ extern struct module __this_module; #endif /* For every exported symbol, place a struct in the __ksymtab section */ -#define __EXPORT_SYMBOL(sym, sec) \ +#define ___EXPORT_SYMBOL(sym, sec) \ extern typeof(sym) sym; \ __CRC_SYMBOL(sym, sec) \ static const char __kstrtab_##sym[] \ @@ -65,6 +65,24 @@ extern struct module __this_module; __attribute__((section("___ksymtab" sec "+" #sym), unused)) \ = { (unsigned long)&sym, __kstrtab_##sym } +#ifdef CONFIG_TRIM_UNUSED_KSYMS + +#include <linux/kconfig.h> +#include <generated/autoksyms.h> + +#define __EXPORT_SYMBOL(sym, sec) \ + __cond_export_sym(sym, sec, config_enabled(__KSYM_##sym)) +#define __cond_export_sym(sym, sec, conf) \ + ___cond_export_sym(sym, sec, conf) +#define ___cond_export_sym(sym, sec, enabled) \ + __cond_export_sym_##enabled(sym, sec) +#define __cond_export_sym_1(sym, sec) ___EXPORT_SYMBOL(sym, sec) +#define __cond_export_sym_0(sym, sec) /* nothing */ + +#else +#define __EXPORT_SYMBOL ___EXPORT_SYMBOL +#endif + #define EXPORT_SYMBOL(sym) \ __EXPORT_SYMBOL(sym, "") |