On Thu, Dec 04, 2003 at 21:34:43 +0100, threadhead@web.de wrote: > hi! > > i've been been coding a LKM that should be > able to use variables, that are declared as extern. > i am using a 2.4.20 kernel. > > the module is based on some code of > kernel/module.c. > (http://lxr.linux.no/source/kernel/module.c) > > well, i tried different stuff with that LKM now. > take as an example: > i have the tulip module loaded. with my LKM i can make use of > extern const char * const medianame[]; > (http://lxr.linux.no/source/drivers/net/tulip/tulip.h) > and display it, when using the same declaration in my LKM. > > but for some strange reason i cannot use > variables that were declared a similar way in .c files in the > kernel source tree. > for example: > extern const struct exception_table_entry __start___ex_table[]; (kernel/module.c) > > why can i access extern vars from header files and not > from source C files, that have been compiled as > part of my current kernel? Only symbols declared EXPROT_SYMBOL (see kernel/ksyms.c) are available to modules. Symbols defined by modules are exported by default unless turned off. ------------------------------------------------------------------------------- Jan 'Bulb' Hudec <bulb@ucw.cz> -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
