On 11/07/2025 16.05, Vlastimil Babka wrote: > Christoph suggested that the explicit _GPL_ can be dropped from the > module namespace export macro, as it's intended for in-tree modules > only. It would be possible to resrict it technically, but it was pointed > out [2] that some cases of using an out-of-tree build of an in-tree > module with the same name are legitimate. But in that case those also > have to be GPL anyway so it's unnecessary to spell it out. > > Link: https://lore.kernel.org/all/aFleJN_fE-RbSoFD@xxxxxxxxxxxxx/ [1] > Link: https://lore.kernel.org/all/CAK7LNATRkZHwJGpojCnvdiaoDnP%2BaeUXgdey5sb_8muzdWTMkA@xxxxxxxxxxxxxx/ [2] > Suggested-by: Christoph Hellwig <hch@xxxxxxxxxxxxx> > Reviewed-by: Shivank Garg <shivankg@xxxxxxx> > Acked-by: Christian Brauner <brauner@xxxxxxxxxx> > Acked-by: David Hildenbrand <david@xxxxxxxxxx> > Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx> > --- > Christian asked [1] for EXPORT_SYMBOL_FOR_MODULES() without the _GPL_ > part to avoid controversy converting selected existing EXPORT_SYMBOL(). > Christoph argued [2] that the _FOR_MODULES() export is intended for > in-tree modules and thus GPL is implied anyway and can be simply dropped > from the export macro name. Peter agreed [3] about the intention for > in-tree modules only, although nothing currently enforces it. > > It seemed straightforward to add this enforcement, so v1 did that. But > there were concerns of breaking the (apparently legitimate) usecases of > loading an updated/development out of tree built version of an in-tree > module. > > So leave out the enforcement part and just drop the _GPL_ from the > export macro name and so we're left with EXPORT_SYMBOL_FOR_MODULES() > only. Any in-tree module used in an out-of-tree way will have to be GPL > anyway by definition. > > Current -next has some new instances of EXPORT_SYMBOL_GPL_FOR_MODULES() > in drivers/tty/serial/8250/8250_rsa.c by commit b20d6576cdb3 ("serial: > 8250: export RSA functions"). Hopefully it's resolvable by a merge > commit fixup and we don't need to provide a temporary alias. > > [1] https://lore.kernel.org/all/20250623-warmwasser-giftig-ff656fce89ad@brauner/ > [2] https://lore.kernel.org/all/aFleJN_fE-RbSoFD@xxxxxxxxxxxxx/ > [3] https://lore.kernel.org/all/20250623142836.GT1613200@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/ > --- > Changes in v2: > - drop the patch to restrict module namespace export for in-tree modules > - fix a pre-existing documentation typo (Nicolas Schier) > - Link to v1: https://patch.msgid.link/20250708-export_modules-v1-0-fbf7a282d23f@xxxxxxx > --- > Documentation/core-api/symbol-namespaces.rst | 8 ++++---- > fs/anon_inodes.c | 2 +- > include/linux/export.h | 2 +- > 3 files changed, 6 insertions(+), 6 deletions(-) > > diff --git a/Documentation/core-api/symbol-namespaces.rst b/Documentation/core-api/symbol-namespaces.rst > index 32fc73dc5529e8844c2ce2580987155bcd13cd09..6f7f4f47d43cdeb3b5008c795d254ca2661d39a6 100644 > --- a/Documentation/core-api/symbol-namespaces.rst > +++ b/Documentation/core-api/symbol-namespaces.rst > @@ -76,8 +76,8 @@ A second option to define the default namespace is directly in the compilation > within the corresponding compilation unit before the #include for > <linux/export.h>. Typically it's placed before the first #include statement. > > -Using the EXPORT_SYMBOL_GPL_FOR_MODULES() macro > ------------------------------------------------ > +Using the EXPORT_SYMBOL_FOR_MODULES() macro > +------------------------------------------- > > Symbols exported using this macro are put into a module namespace. This > namespace cannot be imported. The new naming makes sense, but it breaks the pattern with _GPL suffix: * EXPORT_SYMBOL(sym) * EXPORT_SYMBOL_GPL(sym) * EXPORT_SYMBOL_NS(sym, ns) * EXPORT_SYMBOL_NS_GPL(sym, ns) * EXPORT_SYMBOL_FOR_MODULES(sym, mods) So I think when reading this one may forget about the _obvious_ reason. That's why I think clarifying that in the documentation would be great. Something like: Symbols exported using this macro are put into a module namespace. This namespace cannot be imported. And it's implicitly GPL-only as it's only intended for in-tree modules. Other than that, it looks good. Reviewed-by: Daniel Gomez <da.gomez@xxxxxxxxxxx>
