Sami Tolvanen 6dd43b98c2 FROMLIST: kbuild: lto: postpone objtool ...

With LTO, LLVM bitcode won't be compiled into native code until
modpost_link, or modfinal for modules. This change postpones calls
to objtool until after these steps, and moves objtool_args to
Makefile.lib, so the arguments can be reused in Makefile.modfinal.

As we didn't have objects to process earlier, we use --duplicate
when processing vmlinux.o. This change also disables unreachable
instruction warnings with LTO to avoid warnings about the int3
padding between functions.

Bug: 145210207
Change-Id: I72615f7062d218bf612a5d929f2efb75a18538dd
Link: https://lore.kernel.org/lkml/20201013003203.4168817-12-samitolvanen@google.com/
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>

2020-12-16 08:56:36 -08:00

11 KiB

Executable File

Raw Blame History

View Raw