On Mon, Jun 23, 2025 at 04:21:15PM +0200, Vlastimil Babka wrote: > On 6/23/25 16:01, Christoph Hellwig wrote: > > On Mon, Jun 23, 2025 at 07:00:39AM -0700, Christoph Hellwig wrote: > >> On Mon, Jun 23, 2025 at 12:16:27PM +0200, Christian Brauner wrote: > >> > I'm more than happy to switch a bunch of our exports so that we only > >> > allow them for specific modules. But for that we also need > >> > EXPOR_SYMBOL_FOR_MODULES() so we can switch our non-gpl versions. > >> > >> Huh? Any export for a specific in-tree module (or set thereof) is > >> by definition internals and an _GPL export if perfectly fine and > >> expected. > > Peterz tells me EXPORT_SYMBOL_GPL_FOR_MODULES() is not limited to in-tree > modules, so external module with GPL and matching name can import. > > But if we're targetting in-tree stuff like kvm, we don't need to provide a > non-GPL variant I think? So the purpose was to limit specific symbols to known in-tree module users (hence GPL only). Eg. KVM; x86 exports a fair amount of low level stuff just because KVM. Nobody else should be touching those symbols. If you have a pile of symbols for !GPL / out-of-tree consumers, it doesn't really make sense to limit the export to a named set of modules, does it? So yes, nothing limits things to in-tree modules per-se. The infrastructure only really cares about module names (and implicitly trusts the OS to not overwrite existing kernel modules etc.). So you could add an out-of-tree module name to the list (or have an out-of-free module have a name that matches a glob; "kvm-vmware" would match "kvm-*" for example). But that is very much beyond the intention of things.
