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') 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 From 8c21c4111128365f81a88573eeb2844fa696b299 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Mon, 2 Jun 2025 19:55:36 +0900 Subject: module: make __mod_device_table__* symbols static The __mod_device_table__* symbols are only parsed by modpost to generate MODULE_ALIAS() entries from MODULE_DEVICE_TABLE(). Therefore, these symbols do not need to be globally visible, or globally unique. If they are in the global scope, we would worry about the symbol uniqueness, but modpost is fine with parsing multiple symbols with the same name. Signed-off-by: Masahiro Yamada Reviewed-by: Petr Pavlu --- include/linux/module.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/module.h b/include/linux/module.h index 8050f77c3b64..92e1420fccdf 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -249,8 +249,8 @@ struct module_kobject *lookup_or_create_module_kobject(const char *name); #ifdef MODULE /* Creates an alias so file2alias.c can find device table. */ #define MODULE_DEVICE_TABLE(type, name) \ -extern typeof(name) __mod_device_table__##type##__##name \ - __attribute__ ((unused, alias(__stringify(name)))) +static typeof(name) __mod_device_table__##type##__##name \ + __attribute__ ((used, alias(__stringify(name)))) #else /* !MODULE */ #define MODULE_DEVICE_TABLE(type, name) #endif -- cgit v1.2.3