On 5/2/25 16:12, Peter Zijlstra wrote: > 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 <masahiroy@xxxxxxxxxx> > Requested-by: Christoph Hellwig <hch@xxxxxxxxxxxxx> > Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> > --- > [...] > --- 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" ; > + */ Typo: "cam" -> "can't". I can correct it when picking up the series. Reviewed-by: Petr Pavlu <petr.pavlu@xxxxxxxx> -- Petr > +#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 */ > >
