[PATCH 1/3] fault-inject: improve build for CONFIG_FAULT_INJECTION=n

[Jani Nikula]

On Tue, 13 Aug 2024, Andrew Morton <akpm at linux-foundation.org> wrote:
> On Tue, 13 Aug 2024 15:12:35 +0300 Jani Nikula <jani.nikula at intel.com> wrote:
>
>> The fault-inject.h users across the kernel need to add a lot of #ifdef
>> CONFIG_FAULT_INJECTION to cater for shortcomings in the header. Make
>> fault-inject.h self-contained for CONFIG_FAULT_INJECTION=n, and add
>> stubs for DECLARE_FAULT_ATTR(), setup_fault_attr(), should_fail_ex(),
>> and should_fail() to allow removal of conditional compilation.
>> 
>> --- a/include/linux/fault-inject.h
>> +++ b/include/linux/fault-inject.h
>>  
>> -#include <linux/types.h>
>> -#include <linux/debugfs.h>
>
> Removing a nested include exposes all those sites which were
> erroneously depending upon that nested include.  Here's what I have
> found so far, there will be more.

Right. I didn't hit them with the configs I tried... though I wonder why
not, especially lib/fault-inject.c puzzles me.

How do you want to proceed? Arguably uncovering and fixing those places
is good, but that's kind of an unintended consequence here.

BR,
Jani.


>
> --- a/mm/failslab.c~fault-inject-improve-build-for-config_fault_injection=n-fix
> +++ a/mm/failslab.c
> @@ -1,6 +1,7 @@
>  // SPDX-License-Identifier: GPL-2.0
>  #include <linux/fault-inject.h>
>  #include <linux/error-injection.h>
> +#include <linux/debugfs.h>
>  #include <linux/slab.h>
>  #include <linux/mm.h>
>  #include "slab.h"
> --- a/lib/fault-inject.c~fault-inject-improve-build-for-config_fault_injection=n-fix
> +++ a/lib/fault-inject.c
> @@ -2,6 +2,7 @@
>  #include <linux/kernel.h>
>  #include <linux/init.h>
>  #include <linux/random.h>
> +#include <linux/debugfs.h>
>  #include <linux/sched.h>
>  #include <linux/stat.h>
>  #include <linux/types.h>
> --- a/kernel/futex/core.c~fault-inject-improve-build-for-config_fault_injection=n-fix
> +++ a/kernel/futex/core.c
> @@ -34,6 +34,7 @@
>  #include <linux/compat.h>
>  #include <linux/jhash.h>
>  #include <linux/pagemap.h>
> +#include <linux/debugfs.h>
>  #include <linux/plist.h>
>  #include <linux/memblock.h>
>  #include <linux/fault-inject.h>
> _
>

-- 
Jani Nikula, Intel