From nobody Mon Dec 15 23:43:36 2025 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9F03430E82B; Mon, 15 Dec 2025 07:26:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765783580; cv=none; b=Ojjuesiw8yI4t/PvWQ6gz94b9hZLMXJcoaxa19Dni8d03zVQBHw5l4lhXOTNtEpjQdWHYScKGk3fa2ixzOesn9Dsy6qu9aUrDjaaswF5ovEvV5pGnC1yJyIxIgC6kcg8T/8kknB/fPOei96e8InmrbdxZ+10d7rUtUklc3Gxjsg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765783580; c=relaxed/simple; bh=KXSd9MZrnFCunqVNIQVkaVq7EmYUIaCUSrg+xNneJIM=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=YSo6Rh828FEr17wC9UbsZalSthyiIWjO8DLbiQC364TF301HJhxO/8MGMsOADzxP+e1lNwccCJ3eyabOqfj0ZYxzYUa9sJu5FOR8Kdj8LReMWmlIB6G/Uzd4/iFc88ukca9S9O6YnbUBNmEGfeCqsZSMjwJ8n2oaE10mFKRrX/c= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=nv289lAK; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="nv289lAK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 73169C4CEF5; Mon, 15 Dec 2025 07:26:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1765783580; bh=KXSd9MZrnFCunqVNIQVkaVq7EmYUIaCUSrg+xNneJIM=; h=From:To:Cc:Subject:Date:From; b=nv289lAKLjqyljikfpuKXAxIDklEiHkhXS4yKoPJ3ZWN3rHQDfd18llyYVMaiVOLe J6KNVklGCTxap5DBH0MbmLMbPCAy03Zr1uJ83eulYahi744m2WEjYqwWXUfouoAciG FsdNr5EQUl7EPPrQa9VhwfrHfr+2bniSUBnC9KGqy4wma4JmP2SHFF5OTDtZ6LbEWb 7Sgu0Gtt8CeuY4NGnsNEPxs89MYNGufD0kFRO8YfCDieuKX8+q/ursJQmqFGj2d1jH qx9bEEUBCVpvhyiuSQNIczWgWriVlDI/jiZIvqMQUjKR//LVO81XZQq4pHkYPcPQog gfZBZx5X4DZnw== From: Tzung-Bi Shih To: Kees Cook Cc: Arnd Bergmann , Greg Kroah-Hartman , linux-kernel@vger.kernel.org, Peter Zijlstra , Ingo Molnar , Will Deacon , Boqun Feng , Waiman Long , Shuah Khan , linux-kselftest@vger.kernel.org, tzungbi@kernel.org Subject: [PATCH v3] lkdtm: Add lockdep related crash tests Date: Mon, 15 Dec 2025 07:25:39 +0000 Message-ID: <20251215072539.2580180-1-tzungbi@kernel.org> X-Mailer: git-send-email 2.52.0.305.g3fc767764a-goog Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Introduce various lockdep related crash tests. Signed-off-by: Tzung-Bi Shih --- v3: - Add some entries in tools/testing/selftests/lkdtm/tests.txt. v2: https://lore.kernel.org/all/20251117033337.3730681-1-tzungbi@kernel.org/ - Fix "warning: suggest braces around empty body in an 'else' statement [-W= empty-body]" reported by 0day test robot. v1: https://lore.kernel.org/lkml/20251114062535.1827309-1-tzungbi@kernel.or= g/T/#u drivers/misc/lkdtm/Makefile | 1 + drivers/misc/lkdtm/core.c | 1 + drivers/misc/lkdtm/lkdtm.h | 1 + drivers/misc/lkdtm/lockdep.c | 98 +++++++++++++++++++++++++ tools/testing/selftests/lkdtm/tests.txt | 8 ++ 5 files changed, 109 insertions(+) create mode 100644 drivers/misc/lkdtm/lockdep.c diff --git a/drivers/misc/lkdtm/Makefile b/drivers/misc/lkdtm/Makefile index 03ebe33185f9..830b71c8e6a0 100644 --- a/drivers/misc/lkdtm/Makefile +++ b/drivers/misc/lkdtm/Makefile @@ -11,6 +11,7 @@ lkdtm-$(CONFIG_LKDTM) +=3D usercopy.o lkdtm-$(CONFIG_LKDTM) +=3D kstack_erase.o lkdtm-$(CONFIG_LKDTM) +=3D cfi.o lkdtm-$(CONFIG_LKDTM) +=3D fortify.o +lkdtm-$(CONFIG_LKDTM) +=3D lockdep.o lkdtm-$(CONFIG_PPC_64S_HASH_MMU) +=3D powerpc.o =20 KASAN_SANITIZE_stackleak.o :=3D n diff --git a/drivers/misc/lkdtm/core.c b/drivers/misc/lkdtm/core.c index 5732fd59a227..43e91388940f 100644 --- a/drivers/misc/lkdtm/core.c +++ b/drivers/misc/lkdtm/core.c @@ -96,6 +96,7 @@ static const struct crashtype_category *crashtype_categor= ies[] =3D { &stackleak_crashtypes, &cfi_crashtypes, &fortify_crashtypes, + &lockdep_crashtypes, #ifdef CONFIG_PPC_64S_HASH_MMU &powerpc_crashtypes, #endif diff --git a/drivers/misc/lkdtm/lkdtm.h b/drivers/misc/lkdtm/lkdtm.h index 015e0484026b..d2d97e6f323e 100644 --- a/drivers/misc/lkdtm/lkdtm.h +++ b/drivers/misc/lkdtm/lkdtm.h @@ -84,6 +84,7 @@ extern struct crashtype_category usercopy_crashtypes; extern struct crashtype_category stackleak_crashtypes; extern struct crashtype_category cfi_crashtypes; extern struct crashtype_category fortify_crashtypes; +extern struct crashtype_category lockdep_crashtypes; extern struct crashtype_category powerpc_crashtypes; =20 /* Each category's init/exit routines. */ diff --git a/drivers/misc/lkdtm/lockdep.c b/drivers/misc/lkdtm/lockdep.c new file mode 100644 index 000000000000..e029e9e60ce6 --- /dev/null +++ b/drivers/misc/lkdtm/lockdep.c @@ -0,0 +1,98 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright 2025 Google LLC + * + * Tests related to lockdep warnings. + */ +#include "lkdtm.h" +#include +#include +#include +#include +#include + +static DEFINE_SPINLOCK(lock_A); +static DEFINE_SPINLOCK(lock_B); + +/* For "WARNING: possible circular locking dependency detected". */ +static void lkdtm_LOCKDEP_CIRCULAR_LOCK(void) +{ + scoped_guard(spinlock, &lock_A) + scoped_guard(spinlock, &lock_B) {} + scoped_guard(spinlock, &lock_B) + scoped_guard(spinlock, &lock_A) {} +} + +/* For "WARNING: possible recursive locking detected". */ +static void lkdtm_LOCKDEP_RECURSIVE_LOCK(void) +{ + guard(spinlock)(&lock_A); + guard(spinlock)(&lock_A); +} + +/* For "WARNING: inconsistent lock state". */ +static void lkdtm_LOCKDEP_INCONSISTENT_LOCK(void) +{ + lockdep_softirq_enter(); + scoped_guard(spinlock, &lock_A) {} + lockdep_softirq_exit(); + + scoped_guard(spinlock, &lock_A) {} +} + +/* For "WARNING: Nested lock was not taken". */ +static void lkdtm_LOCKDEP_NESTED_LOCK_NOT_HELD(void) +{ + spin_lock_nest_lock(&lock_B, &lock_A); +} + +/* For "WARNING: bad unlock balance detected!". */ +static void lkdtm_LOCKDEP_BAD_UNLOCK_BALANCE(void) +{ + spin_unlock(&lock_A); +} + +/* For "WARNING: held lock freed!". */ +static void lkdtm_LOCKDEP_HELD_LOCK_FREED(void) +{ + spin_lock(&lock_A); + spin_lock_init(&lock_A); +} + +/* For "WARNING: lock held when returning to user space!". */ +static void lkdtm_LOCKDEP_HELD_LOCK(void) +{ + spin_lock(&lock_A); +} + +/* For "WARNING: suspicious RCU usage". */ +static void lkdtm_LOCKDEP_SUSPICIOUS_RCU(void) +{ + struct srcu_struct srcu; + void __rcu *res =3D NULL; + int idx; + + init_srcu_struct(&srcu); + + idx =3D srcu_read_lock(&srcu); + rcu_dereference(res); + srcu_read_unlock(&srcu, idx); + + cleanup_srcu_struct(&srcu); +} + +static struct crashtype crashtypes[] =3D { + CRASHTYPE(LOCKDEP_CIRCULAR_LOCK), + CRASHTYPE(LOCKDEP_RECURSIVE_LOCK), + CRASHTYPE(LOCKDEP_INCONSISTENT_LOCK), + CRASHTYPE(LOCKDEP_NESTED_LOCK_NOT_HELD), + CRASHTYPE(LOCKDEP_BAD_UNLOCK_BALANCE), + CRASHTYPE(LOCKDEP_HELD_LOCK_FREED), + CRASHTYPE(LOCKDEP_HELD_LOCK), + CRASHTYPE(LOCKDEP_SUSPICIOUS_RCU), +}; + +struct crashtype_category lockdep_crashtypes =3D { + .crashtypes =3D crashtypes, + .len =3D ARRAY_SIZE(crashtypes), +}; diff --git a/tools/testing/selftests/lkdtm/tests.txt b/tools/testing/selfte= sts/lkdtm/tests.txt index cff124c1eddd..7b32dece3d3a 100644 --- a/tools/testing/selftests/lkdtm/tests.txt +++ b/tools/testing/selftests/lkdtm/tests.txt @@ -83,3 +83,11 @@ FORTIFY_STR_MEMBER detected buffer overflow FORTIFY_MEM_OBJECT detected buffer overflow FORTIFY_MEM_MEMBER detected field-spanning write PPC_SLB_MULTIHIT Recovered +#LOCKDEP_CIRCULAR_LOCK Lockdep can only trigger once +#LOCKDEP_RECURSIVE_LOCK Hangs the system +#LOCKDEP_INCONSISTENT_LOCK Lockdep can only trigger once +#LOCKDEP_NESTED_LOCK_NOT_HELD Cause a deadlock in subsequent lockdep tests +#LOCKDEP_BAD_UNLOCK_BALANCE Lockdep can only trigger once +#LOCKDEP_HELD_LOCK_FREED Lockdep can only trigger once +#LOCKDEP_HELD_LOCK Cause a deadlock in subsequent lockdep tests +#LOCKDEP_SUSPICIOUS_RCU Lockdep can only trigger once --=20 2.52.0.305.g3fc767764a-goog