Re: [PATCH 1/3] Kconfig: disable PROFILE_ALL_BRANCHES for compile testing

From: Arnd Bergmann
Date: Fri Feb 16 2018 - 17:14:51 EST


On Fri, Feb 16, 2018 at 11:03 PM, Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
> On Fri, 16 Feb 2018 22:41:11 +0100
> Arnd Bergmann <arnd@xxxxxxxx> wrote:
>
>> This can easily double the time for compiling a driver but does not
>> provide any benefit for the compile tester, so it's better left disabled.
>>
>> In addition, any 'inline' function that is not also 'static' and that
>> contains an 'if' causes a warning like
>>
>> include/linux/string.h:212:2: note: in expansion of macro 'if'
>> if (strscpy(p, q, p_size < q_size ? p_size : q_size) < 0)
>> ^~
>> include/linux/compiler.h:162:4: warning: '______f' is static but declared in inline function 'strcpy' which is not static
>>
>> without this patch, and I could not come up with a nice fix for that.
>> In combination with my patch to always enable 'CONFIG_COMPILE_TEST'
>> during 'randconfig' builds, we can at least hide these warnings for
>> most users.
>
> This looks like it fixes the same issue that was already fixed and is
> in Linus's tree.
>
> http://lkml.kernel.org/r/9199446b-a141-c0c3-9678-a3f9107f2750@xxxxxxxxxxxxx
>
> See commit 68e76e034b6b1 ("tracing: Prevent PROFILE_ALL_BRANCHES when
> FORTIFY_SOURCE=y")

Ah, right. I missed that when I wrote the new changelog text for this old
patch of mine. It also means I should rebase the patch so it applies
on mainline, as I still want PROFILE_ALL_BRANCHES to be disabled
in COMPILE_TEST kernels for the build speed aspect.

Greg, could you add the 68e76e034b6b1 commit to 4.14-stable and
4.15-stable in the meantime?

Arnd