[PATCH] arm64: Fix 'lock held when returning to user space' lockdep warning

Eric Chan
2023-05-26T18:48:36Z

The arm64 architecture lacks support for CONFIG_GENERIC_ENTRY, resulting
in the failure to report the lockdep warning
"lock held when returning to user space" when lockdep is enabled.

Rename the function to align with exit_to_user_mode_prepare in
kernel/entry/common.c to improve readability.

Signed-off-by: Eric Chan <ericchancf@google.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