From: Eric Chan <ericchancf@google.com>
To: Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
Mark Rutland <mark.rutland@arm.com>
Cc: "Paul E . McKenney" <paulmck@kernel.org>,
Anshuman Khandual <anshuman.khandual@arm.com>,
Frederic Weisbecker <frederic@kernel.org>,
Mukesh Ojha <quic_mojha@quicinc.com>,
Josh Poimboeuf <jpoimboe@kernel.org>,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, Eric Chan <ericchancf@google.com>
Subject: [PATCH v2] arm64: lockdep: enable checks for held locks when returning to userspace
Date: Wed, 31 May 2023 09:09:09 +0000 [thread overview]
Message-ID: <20230531090909.357047-1-ericchancf@google.com> (raw)
Currently arm64 doesn't use CONFIG_GENERIC_ENTRY and doesn't call
lockdep_sys_exit() when returning to userspace.
This means that lockdep won't check for held locks when
returning to userspace, which would be useful to detect kernel bugs.
Call lockdep_sys_exit() when returning to userspace,
enabling checking for held locks.
At the same time, rename arm64's prepare_exit_to_user_mode() to
exit_to_user_mode_prepare() to more clearly align with the naming
in the generic entry code.
Signed-off-by: Eric Chan <ericchancf@google.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
---
arch/arm64/kernel/entry-common.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/kernel/entry-common.c b/arch/arm64/kernel/entry-common.c
index 3af3c01c93a6..9d6827201b6c 100644
--- a/arch/arm64/kernel/entry-common.c
+++ b/arch/arm64/kernel/entry-common.c
@@ -126,7 +126,7 @@ static __always_inline void __exit_to_user_mode(void)
lockdep_hardirqs_on(CALLER_ADDR0);
}
-static __always_inline void prepare_exit_to_user_mode(struct pt_regs *regs)
+static __always_inline void exit_to_user_mode_prepare(struct pt_regs *regs)
{
unsigned long flags;
@@ -135,11 +135,13 @@ static __always_inline void prepare_exit_to_user_mode(struct pt_regs *regs)
flags = read_thread_flags();
if (unlikely(flags & _TIF_WORK_MASK))
do_notify_resume(regs, flags);
+
+ lockdep_sys_exit();
}
static __always_inline void exit_to_user_mode(struct pt_regs *regs)
{
- prepare_exit_to_user_mode(regs);
+ exit_to_user_mode_prepare(regs);
mte_check_tfsr_exit();
__exit_to_user_mode();
}
--
2.41.0.rc0.172.g3f132b7071-goog
V1 -> V2 : Revise the commit message to make it clearer and avoid any misleading information.
next reply other threads:[~2023-05-31 9:10 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-31 9:09 Eric Chan [this message]
2023-06-06 17:30 ` [PATCH v2] arm64: lockdep: enable checks for held locks when returning to userspace Catalin Marinas
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