On Tue, Nov 14, 2017 at 12:40:31PM +0100, Arnd Bergmann wrote: > Some drivers use debugfs_real_fops() even when CONFIG_DEBUG_FS is disabled, > which now leads to a build error: > > In file included from include/linux/list.h:9:0, > from include/linux/wait.h:7, > from include/linux/wait_bit.h:8, > from include/linux/fs.h:6, > from drivers/net/wireless/broadcom/b43legacy/debugfs.c:26: > drivers/net/wireless/broadcom/b43legacy/debugfs.c: In function > 'b43legacy_debugfs_read': > drivers/net/wireless/broadcom/b43legacy/debugfs.c:224:23: error: implicit > declaration of function 'debugfs_real_fops'; did you mean > 'debugfs_create_bool'? [-Werror=implicit-function-declaration] > > My first impulse was to add another 'static inline' dummy function > returning NULL for it, which would work fine. However, most callers > feed the pointer into container_of(), so it seems a little dangerous > here. Since all the callers are inside of a read/write file operation > that gets eliminated in this configuration, so having an 'extern' > declaration seems better here. If it ever gets used in a dangerous > way, that will now result in a link error.
Ok, but does your patch really "fix" anything? The linker should now complain, not the compiler, for these types of configurations? thanks, greg k-h
