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authorNicolas Pitre <nicolas.pitre@linaro.org>2016-01-22 01:32:26 -0500
committerNicolas Pitre <nicolas.pitre@linaro.org>2016-03-29 16:18:53 -0400
commitf235541699bcf14fb8be797c6bc1d7106df0eb64 (patch)
tree6707edc556076ba677ca4fbb68054bbe128857af /include/linux/export.h
parent9895c03d48115c7783c0ef0a591447d53254ef84 (diff)
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.h22
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, "")