lockdep: allow instrumenting lockdep.c with KMSAN

Lockdep and KMSAN used to play badly together, causing deadlocks when
KMSAN instrumentation of lockdep.c called lockdep functions recursively.

Looks like this is no more the case, and a kernel can run (yet slower)
with both KMSAN and lockdep enabled.  This patch should fix false
positives on wq_head->lock->dep_map, which KMSAN used to consider
uninitialized because of lockdep.c not being instrumented.

Link: https://lore.kernel.org/lkml/Y3b9AAEKp2Vr3e6O@sol.localdomain/
Link: https://lkml.kernel.org/r/20221128094541.2645890-1-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Reported-by: Eric Biggers <ebiggers@kernel.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Marco Elver <elver@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Alexander Potapenko 2022-11-28 10:45:40 +01:00 committed by Andrew Morton
parent d3a8923358
commit 1e8e4a7cc2

View File

@ -7,7 +7,6 @@ obj-y += mutex.o semaphore.o rwsem.o percpu-rwsem.o
# Avoid recursion lockdep -> sanitizer -> ... -> lockdep.
KCSAN_SANITIZE_lockdep.o := n
KMSAN_SANITIZE_lockdep.o := n
ifdef CONFIG_FUNCTION_TRACER
CFLAGS_REMOVE_lockdep.o = $(CC_FLAGS_FTRACE)