On 5/24/21 6:41 PM, Randy Dunlap wrote:
Some arches (um, sparc64, riscv, 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. But wait. LOCKDEP_SUPPORT is included in LOCK_DEBUGGING_SUPPORT, which is already a dependency here, so LOCKDEP_SUPPORT is redundant and not needed. That leaves the FRAME_POINTER dependency, but it is part of an expression like this: depends on (A && B) && (FRAME_POINTER || B') where B' is a dependency of B so if B is true then B' is true and the value of FRAME_POINTER does not matter. Thus we can also delete the FRAME_POINTER dependency. Fixes this kconfig warning: (for um, sparc64, riscv, 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] Link to v1: https://lore.kernel.org/lkml/20210517034430.9569-1-rdunlap@xxxxxxxxxxxxx/ Fixes: 7d37cb2c912d ("lib: fix kconfig dependency on ARCH_WANT_FRAME_POINTERS") 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 Cc: Julian Braha <julianbraha@xxxxxxxxx> Cc: linux-arch@xxxxxxxxxxxxxxx --- @Julian: please take a look. I'm a little concerned about the FRAME_POINTER dependency going away when our 2 patches are combined. v2: drop depends on LOCKDEP_SUPPORT for LOCKDEP; the use of LOCK_DEBUGGING_SUPPORT already covers that dependency; drop FRAME_POINTER dependency (thanks to Waiman Long for both of these suggestions) v2: add CC: to linux-arch lib/Kconfig.debug | 1 - 1 file changed, 1 deletion(-) --- linux-next-20210524.orig/lib/Kconfig.debug +++ linux-next-20210524/lib/Kconfig.debug @@ -1383,7 +1383,6 @@ config LOCKDEP bool depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT select STACKTRACE - depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86 select KALLSYMS select KALLSYMS_ALL
Acked-by: Waiman Long <longman@xxxxxxxxxx> Cheers, Longman
