Re: [linux-next:master 7012/7430] include/linux/compiler_types.h:328:38: error: call to '__compiletime_assert_183' declared with attribute error: unexpected size in kmalloc_index()

[Vlastimil Babka <vbabka@suse.cz>]

On 6/7/21 5:49 PM, Hyeonggon Yoo wrote:
> On Mon, Jun 07, 2021 at 05:27:27PM +0200, Vlastimil Babka wrote:
>> On 6/7/21 2:25 PM, Hyeonggon Yoo wrote:
>> > On Mon, Jun 07, 2021 at 01:40:02PM +0200, Vlastimil Babka wrote:
>> >> On 6/6/21 1:08 PM, Hyeonggon Yoo wrote:
>> >> > On Sat, Jun 05, 2021 at 02:10:46PM +0800, kernel test robot wrote:
>> >> 
>> >> But what exactly is the gcc problem here?
>> >> Did you have to reproduce it with specific gcc version and/or architecture?
>> >> 
>> > 
>> > Before replying, I should say that I'm not an expert on gcc.
>> > I just tried some ways to fix the error, and it seemed to me that
>> > gcc is doing something wrong.
>> 
>> I'm involving my gcc colleagues, will report results...

Well, it seems the bot's .config included CONFIG_PROFILE_ALL_BRANCHES as the
main factor to trigger the problem. And (according to my colleagues) it might
add too many instrumented if conditions to sustain the builtin-constant
tracking, which is not unlimited, or interact with optimizations in some other
corner case way.

I guess we could add IS_ENABLED(CONFIG_PROFILE_ALL_BRANCHES) to the list of
conditions that excludes using BUILD_BUG_ON_MSG().

> Thank you so much!
> 
> Hyeonggon
>