Re: more build problems with "Makefile: move stackprotector availability out of Kconfig"

From: Arnd Bergmann
Date: Tue Oct 17 2017 - 14:47:14 EST


On Tue, Oct 17, 2017 at 8:41 PM, Arnd Bergmann <arnd@xxxxxxxx> wrote:
> On Tue, Oct 17, 2017 at 8:26 PM, Kees Cook <keescook@xxxxxxxxxxxx> wrote:
>> On Tue, Oct 17, 2017 at 8:52 AM, Arnd Bergmann <arnd@xxxxxxxx> wrote:
>>> On Tue, Oct 17, 2017 at 5:34 PM, Kees Cook <keescook@xxxxxxxxxxxx> wrote:
>
>>> index dbfb978..d5bc694 100755
>>> --- a/config.guess
>>> +++ b/config.guess
>>> @@ -1021,7 +1021,7 @@ EOF
>>> echo ${UNAME_MACHINE}-dec-linux-${LIBC}
>>> exit ;;
>>> x86_64:Linux:*:*)
>>> - echo ${UNAME_MACHINE}-unknown-linux-${LIBC}
>>> + echo ${UNAME_MACHINE}-pc-linux-${LIBC}
>>> exit ;;
>>> xtensa*:Linux:*:*)
>>> echo ${UNAME_MACHINE}-unknown-linux-${LIBC}
>>>
>>> I still don't know why that makes a difference, but all versions
>>> prior to gcc-6.1 have the problem for me.
>>
>> What happens if you add -mstack-protector-guard=tls ?
>
> With gcc-4.8 an earlier, I get build failure:
>
> cc1: error: unrecognized command line option "-mstack-protector-guard=tls"
>
> With gcc-4.9 and gcc-5, I get this output:
>

To clarify: with my gcc-4.9/gcc-5 build, -mstack-protector-guard=tls
has no effect,
the output is the same as with -mstack-protector-guard=global using the Ubuntu
compilers of the same version.

Arnd