Re: [PATCH] LOCKDEP: use depends on LOCKDEP_SUPPORT instead of $ARCH list

From: Ingo Molnar
Date: Mon May 17 2021 - 03:11:09 EST



* Randy Dunlap <rdunlap@xxxxxxxxxxxxx> wrote:

> Both arch/um/ and arch/xtensa/ cause a Kconfig warning for LOCKDEP.
> These arch-es select LOCKDEP_SUPPORT but they are not listed as one
> of the arch-es that LOCKDEP depends on.
>
> Since (16) arch-es define the Kconfig symbol LOCKDEP_SUPPORT if they
> intend to have LOCKDEP support, replace the awkward list of
> arch-es that LOCKDEP depends on with the LOCKDEP_SUPPORT symbol.
>
> Fixes this kconfig warning: (for both um and xtensa)
>
> WARNING: unmet direct dependencies detected for LOCKDEP
> Depends on [n]: DEBUG_KERNEL [=y] && LOCK_DEBUGGING_SUPPORT [=y] && (FRAME_POINTER [=n] || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86)
> Selected by [y]:
> - PROVE_LOCKING [=y] && DEBUG_KERNEL [=y] && LOCK_DEBUGGING_SUPPORT [=y]
> - LOCK_STAT [=y] && DEBUG_KERNEL [=y] && LOCK_DEBUGGING_SUPPORT [=y]
> - DEBUG_LOCK_ALLOC [=y] && DEBUG_KERNEL [=y] && LOCK_DEBUGGING_SUPPORT [=y]
>
> Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> Cc: Will Deacon <will@xxxxxxxxxx>
> Cc: Waiman Long <longman@xxxxxxxxxx>
> Cc: Boqun Feng <boqun.feng@xxxxxxxxx>
> Cc: Chris Zankel <chris@xxxxxxxxxx>
> Cc: Max Filippov <jcmvbkbc@xxxxxxxxx>
> Cc: linux-xtensa@xxxxxxxxxxxxxxxx
> Cc: Johannes Berg <johannes@xxxxxxxxxxxxxxxx>
> Cc: Jeff Dike <jdike@xxxxxxxxxxx>
> Cc: Richard Weinberger <richard@xxxxxx>
> Cc: Anton Ivanov <anton.ivanov@xxxxxxxxxxxxxxxxxx>
> Cc: linux-um@xxxxxxxxxxxxxxxxxxx
> ---
> lib/Kconfig.debug | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> --- linux-next-20210514.orig/lib/Kconfig.debug
> +++ linux-next-20210514/lib/Kconfig.debug
> @@ -1383,7 +1383,7 @@ config LOCKDEP
> bool
> depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
> select STACKTRACE
> - depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86
> + depends on FRAME_POINTER || LOCKDEP_SUPPORT

Ok - the FRAME_POINTER bit is weird. Are there any architectures that have
FRAME_POINTER defined but no LOCKDEP_SUPPORT?

Thanks,

Ingo