Re: [v2 PATCH] printk: Make linux/printk.h self-contained

Petr Mladek
2020-06-12T13:14:14Z

On Fri 2020-06-12 14:36:35, Herbert Xu wrote:
> As it stands if you include printk.h by itself it will fail to
> compile because it requires definitions from ratelimit.h. However,
> simply including ratelimit.h from printk.h does not work due to
> inclusion loops involving sched.h and kernel.h.
>
> This patch solves this by moving bits from ratelimit.h into a new
> header file which can then be included by printk.h without any
> worries about header loops.
>
> The build bot then revealed some intriguing failures arising out
> of this patch. On s390 there is an inclusion loop with asm/bug.h
> and linux/kernel.h that triggers a compile failure, because kernel.h
> will cause asm-generic/bug.h to be included before s390's own
> asm/bug.h has finished processing. This has been fixed by not
> including kernel.h in arch/s390/include/asm/bug.h.
>
> A related failure was seen on powerpc where asm/bug.h leads to
> the inclusion of linux/kernel.h via asm-generic/bug.h which then
> prematurely tries to use the very macros defined in asm/bug.h.
> The particular inclusion path which led to this involves lockdep.h.
> I have fixed this moving the type definitions lockdep.h into the
> new lockdep_types.h.
>
> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

I am fine with the changes as long as the kernel test robot
does not complain ;-)

Acked-by: Petr Mladek <pmladek@suse.com>

Well, I wonder if PeterZ is fine with the lockdep part. It might make
sense to split it into separate patch as a prerequisite.

Best Regards,
Petr