Re: [PATCH] kbuild: Abort build on bad stack protector flag

From: Kees Cook
Date: Sat Jul 09 2016 - 12:59:34 EST


On Sat, Jul 9, 2016 at 5:03 AM, Ingo Molnar <mingo@xxxxxxxxxx> wrote:
>
> * Kees Cook <keescook@xxxxxxxxxxxx> wrote:
>
>> Before, the stack protector flag was sanity checked before .config had
>> been reprocessed. This meant the build couldn't be aborted early, and
>> only a warning could be emitted followed later by the compiler blowing
>> up with an unknown flag. This has caused a lot of confusion over time,
>> so this splits the flag selection from sanity checking and performs the
>> sanity checking after the make has been restarted from a reprocessed
>> .config, so builds can be aborted as early as possible now.
>>
>> Additionally moves the x86-specific sanity check to the same location,
>> since it suffered from the same warn-then-wait-for-compiler-failure
>> problem.
>>
>> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
>> ---
>> Makefile | 69 +++++++++++++++++++++++++++++++++----------------------
>> arch/x86/Makefile | 8 -------
>> 2 files changed, 42 insertions(+), 35 deletions(-)
>
> What's the status of this patch? I can merge it if Michal acks the main Makefile
> bits.

There's been no feedback yet, but I'd really like to see it landed: it
removes a lot of ambiguity for this option (and creates a place for
future similar options).

-Kees

--
Kees Cook
Chrome OS & Brillo Security