Re: finding unused globals in the kernel

From: Arnd Bergmann
Date: Mon Mar 01 2004 - 14:37:05 EST


On Monday 01 March 2004 15:32, Marcelo Tosatti wrote:
>
> On Sat, 28 Feb 2004, Arnd Bergmann wrote:
> > bash /home/arnd/linux-2.6-ipc/scripts/checkunused.sh i386 arch/i386/kernel/head.o arch/i386/kernel/init_task.o init/built-in.o usr/built-in.o arch/i386/kernel/built-in.o arch/i386/mm/built-in.o arch/i386/mach-default/built-in.o kernel/built-in.o mm/built-in.o fs/built-in.o ipc/built-in.o security/built-in.o crypto/built-in.o lib/lib.a arch/i386/lib/lib.a lib/built-in.o arch/i386/lib/built-in.o drivers/built-in.o sound/built-in.o arch/i386/pci/built-in.o arch/i386/oprofile/built-in.o arch/i386/power/built-in.o net/built-in.o
> > unreferenced definition VSYSCALL_BASE
>
> It seems your script is behaving wrongly for the VSYSCALL_BASE case
> (probably others too):
>
> elf.h:
>
> #define VSYSCALL_BASE (__fix_to_virt(FIX_VSYSCALL))
> #define VSYSCALL_EHDR ((const struct elfhdr *) VSYSCALL_BASE)
> #define VSYSCALL_ENTRY ((unsigned long) &__kernel_vsyscall)
> extern void __kernel_vsyscall;

Actually, VSYSCALL_BASE is defined as an absolute symbol in
arch/i386/kernel/vsyscall.lds, so it's not as broken as one might think.
The bug is that the script cannot find symbols defined by the linker
and used only as a constant in the same linker script. Fortunately, this
isn't done in many places.

Arnd <><
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/