On 12/14/19 1:50 PM, Dan Aloni wrote:
On Fri, Dec 13, 2019 at 03:28:38PM -0500, Stephen Smalley wrote:
I would have expected that two kernels built with the same config
with this enabled would have yielded different struct layouts in
pahole vmlinux output, but that doesn't appear to be the case. They
do have different seeds. Am I doing something wrong?
Also, does DEBUG_INFO_BTF effectively undermine/negate the benefits of this
change if enabled?
There's currently a long-standing bug with the GCC plugin where the
generated debug info is in declaration order, not build order (see:
[1]). So, to verify it, try looking at the generated machine code.
Thanks for that clarification; I can see in the code that the struct
layout has changed between the two kernel builds.
Planned Clang implementation of this feature does not have this bug.
[1] https://gcc.gnu.org/bugzilla/show_bug.cgi?format=multiple&id=84052
