Re: [PATCH v3 4/7] init: main: add KUnit to kernel init

[Kees Cook <keescook@chromium.org>]

On 2/27/20 7:20 PM, Brendan Higgins wrote:
> Remove KUnit from init calls entirely, instead call directly from
> kernel_init().
> 
> Co-developed-by: Alan Maguire <alan.maguire@oracle.com>
> Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
> Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
> Reviewed-by: Stephen Boyd <sboyd@kernel.org>
> [...]
> diff --git a/init/main.c b/init/main.c
> index ee4947af823f3..7875a5c486dc4 100644
> --- a/init/main.c
> +++ b/init/main.c
> @@ -104,6 +104,8 @@
>  #define CREATE_TRACE_POINTS
>  #include <trace/events/initcall.h>
>  
> +#include <kunit/test.h>
> +
>  static int kernel_init(void *);
>  
>  extern void init_IRQ(void);
> @@ -1444,6 +1446,8 @@ static noinline void __init kernel_init_freeable(void)
>  
>  	do_basic_setup();
>  
> +	kunit_run_all_tests();
> +
>  	console_on_rootfs();
>  
>  	/*

I'm nervous about this happening before two key pieces of the kernel
setup, which might lead to weird timing-sensitive bugs or false
positives:
	async_synchronize_full()
	mark_readonly()

Now, I realize kunit tests _should_ be self-contained, but this seems
like a possible robustness problem. Is there any reason this can't be
moved after rcu_end_inkernel_boot() in kernel_init() instead?

-- 
Kees Cook