From 707f853d7fa3ce323a6875487890c213e34d81a0 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Fri, 2 May 2025 16:12:09 +0200 Subject: module: Provide EXPORT_SYMBOL_GPL_FOR_MODULES() helper Helper macro to more easily limit the export of a symbol to a given list of modules. Eg: EXPORT_SYMBOL_GPL_FOR_MODULES(preempt_notifier_inc, "kvm"); will limit the use of said function to kvm.ko, any other module trying to use this symbol will refure to load (and get modpost build failures). Requested-by: Masahiro Yamada Requested-by: Christoph Hellwig Signed-off-by: Peter Zijlstra Reviewed-by: Petr Pavlu Signed-off-by: Masahiro Yamada --- include/linux/export.h | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) (limited to 'include/linux/export.h') diff --git a/include/linux/export.h b/include/linux/export.h index a8c23d945634..f35d03b4113b 100644 --- a/include/linux/export.h +++ b/include/linux/export.h @@ -24,11 +24,17 @@ .long sym #endif -#define ___EXPORT_SYMBOL(sym, license, ns) \ +/* + * LLVM integrated assembler cam merge adjacent string literals (like + * C and GNU-as) passed to '.ascii', but not to '.asciz' and chokes on: + * + * .asciz "MODULE_" "kvm" ; + */ +#define ___EXPORT_SYMBOL(sym, license, ns...) \ .section ".export_symbol","a" ASM_NL \ __export_symbol_##sym: ASM_NL \ .asciz license ASM_NL \ - .asciz ns ASM_NL \ + .ascii ns "\0" ASM_NL \ __EXPORT_SYMBOL_REF(sym) ASM_NL \ .previous @@ -85,4 +91,6 @@ #define EXPORT_SYMBOL_NS(sym, ns) __EXPORT_SYMBOL(sym, "", ns) #define EXPORT_SYMBOL_NS_GPL(sym, ns) __EXPORT_SYMBOL(sym, "GPL", ns) +#define EXPORT_SYMBOL_GPL_FOR_MODULES(sym, mods) __EXPORT_SYMBOL(sym, "GPL", "module:" mods) + #endif /* _LINUX_EXPORT_H */ -- cgit v1.2.3