Deterministic builds, part 2

[Mark Johnston]

On Thu, Nov 25, 2010 at 01:08:58PM +0100, Erik Cederstrand wrote:
> Kernel modules:
> ----------------------
> In the ELF section .gnu-debuglink, there is a link to the corresponding *.ko.symbols file. It seems to be an inode or such rather than a file path since nothing shows up in strings(1). I have commented out "makeoptions DEBUG=-g" in the GENERIC kernel conf file which I am testing now, but I'd like to know what is actually going on.

The .gnu_debuglink segment contains the name of the debug symbols file
(i.e. not a full path or an inode number). I'm not sure why it doesn't
show up with strings(1), but you can see it with a hex editor.

When gdb loads an object file with a gnu_debuglink segment, it looks in
a few pre-defined locations for the corresponding symbols file. The gdb
docs explain it pretty well:

http://sourceware.org/gdb/onlinedocs/gdb/Separate-Debug-Files.html

-Mark