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From: Alexander Potapenko <glider@google.com>
To: glider@google.com
Cc: linux-kernel@vger.kernel.org, akpm@linux-foundation.org,
	 peterz@infradead.org, mingo@redhat.com, will@kernel.org,
	elver@google.com,  dvyukov@google.com, linux-mm@kvack.org,
	kasan-dev@googlegroups.com,  Eric Biggers <ebiggers@kernel.org>
Subject: [PATCH 1/2] lockdep: allow instrumenting lockdep.c with KMSAN
Date: Mon, 28 Nov 2022 10:45:40 +0100	[thread overview]
Message-ID: <20221128094541.2645890-1-glider@google.com> (raw)

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/
Reported-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Alexander Potapenko <glider@google.com>
---
 kernel/locking/Makefile | 1 -
 1 file changed, 1 deletion(-)

diff --git a/kernel/locking/Makefile b/kernel/locking/Makefile
index ea925731fa40f..0db4093d17b8a 100644
--- a/kernel/locking/Makefile
+++ b/kernel/locking/Makefile
@@ -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)
-- 
2.38.1.584.g0f3c55d4c2-goog



             reply	other threads:[~2022-11-28  9:45 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-11-28  9:45 Alexander Potapenko [this message]
2022-11-28  9:45 ` [PATCH 2/2] kmsan: allow using __msan_instrument_asm_store() inside runtime Alexander Potapenko

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