Hi!
I have a short utility program which has been written to be used both
for normal user space apps , as well a kernel modules. Now, the code
is #def'ed to use the correct kernel equivalents(like kmalloc()) for module
compilations, and libc equivalents(like malloc()) and so it is safe enough.
My problem is that I need to use the utility functions of this code in just
one module, without polluting the kernel symbol table with the
function identifiers. So I made the storage class of the functions
depend on the context it is being compiled in. In __KERNEL__ mode, it
is #defined to "static" and in normal applications it is defined as
"extern". This is because in all cases this utility file is separetely
compiled as an object file.
e.g.
kgcc -Wall -DMODULE -D__KERNEL__ -c util.c
kgcc -Wall -DMODULE -D__KERNEL__ -c _mymodule.c
ld -m elf_i386 -o mymodule.o _mymodule.o util.o
for the module compilations
and
touch util.c
kgcc -Wall -c util.c
kgcc -Wall -c _myapp.c
ld -m elf_i386 -o myapp.o _myapp.o util.o
for the app compilations
Is this at all sane? If I define the storage class of the util.c
functions as static, they _should_not_ be exported to the mymodule.c
module. But it compiles and links. :)
If I leave them as static always, the userspace app compilations would
warn me saying that while compiling the util.c program the functions
were declared static but never used. A warning that i can ignore,
... but then I hate _any_ warnings during compilations. ;)
How do you make a kernel module with multiple source files anyway,
without exporting all the symbols to the kernel symbol table? Is this
the reason why _most_ of the kernel modules are single source files?
- Sandip
--
-------------------------------------
Sandip Bhattacharya
sandipb @ bigfoot.com
http://www.sandipb.net
-------------------------------------
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