file names embedded in kernel image

file names embedded in kernel image

[Rasmus Villemoes]

Hi

I just noticed that when one build the kernel outside the source tree,
all __FILE__ occurences get replaced with the absolute path (since
that's what is given to gcc, and most -I paths are also absolute). This
ends up wasting quite a lot of space in .rodata, and I suppose most
distro supplied kernels have this issue. For example, my ubuntu kernel
is full of strings like

/build/linux-hFNI9K/linux-3.13.0/arch/x86/platform/sfi/sfi.c
/build/linux-hFNI9K/linux-3.13.0/kernel/fork.c

The /build/linux-hFNI9K/linux-3.13.0/ prefixes add up (and since it's an
artifact of the build process, wouldn't add any value in a bug-report
which one wouldn't also get from uname -a).

Distros could avoid this by building in-tree (maybe some already do) but
I was wondering if we could do something upstream.

Rasmus

Re: file names embedded in kernel image

[Michal Marek]

Dne 27.8.2015 v 11:44 Rasmus Villemoes napsal(a):
> Hi
> 
> I just noticed that when one build the kernel outside the source tree,
> all __FILE__ occurences get replaced with the absolute path (since
> that's what is given to gcc, and most -I paths are also absolute). This
> ends up wasting quite a lot of space in .rodata, and I suppose most
> distro supplied kernels have this issue. For example, my ubuntu kernel
> is full of strings like
> 
> /build/linux-hFNI9K/linux-3.13.0/arch/x86/platform/sfi/sfi.c
> /build/linux-hFNI9K/linux-3.13.0/kernel/fork.c

If you build in a subdirectory of the source tree, the filenames will
look like

../arch/x86/platform/sfi/sfi.c
../kernel/fork.c

Michal