On Wed, May 11, 2022 at 07:34:38PM +0200, Javier Martinez Canillas wrote: > Hello Guenter, > > On 5/11/22 19:17, Guenter Roeck wrote: > > On 5/11/22 10:00, Sam Ravnborg wrote: > > [snip] > > >>> struct fb_info *registered_fb[FB_MAX] __read_mostly; > >>> -EXPORT_SYMBOL(registered_fb); > >>> - > >>> int num_registered_fb __read_mostly; > >>> +#if IS_ENABLED(CONFIG_FB_OLPC_DCON) > >>> +EXPORT_SYMBOL(registered_fb); > >>> EXPORT_SYMBOL(num_registered_fb); > >>> +#endif > >> > >> It is stuff like this I refer to as "ugly" in the comment above. > >> > > > > My "solution" for that kind of thing is to use a namespace, > > such as > > > > EXPORT_SYMBOL_NS(registered_fb, FB_OLPC_DCON); > > EXPORT_SYMBOL_NS(num_registered_fb, FB_OLPC_DCON); > > > > Using a namespace in this case is indeed a great idea I think. > > I've used in the past to limit the export of a symbol for within a driver > that could be scattered across different compilations units, but it never > occurred to me using it to limit symbols exported by core code. > > > and import it from the offending code. That avoids ifdefs > > while at the same time limiting the use of the symbols > > to the expected scope. Of course that could be abused but > > that abuse would be obvious. > > > > Agreed. For the next revision, besides using an namespaced export symbol > as you suggested, I'll include a comment to make clear that it shouldn't > by any other driver and FB_OLPC_DCON fixed instead. A very nice compromise, thanks Guenter and Javier. Sam
