[RFC 04/30] x86/entry: Move lockdep_sys_exit to prepare_exit_to_usermode

[Andy Lutomirski <luto@kernel.org>]

Rather than worrying about exactly where LOCKDEP_SYS_EXIT should go
in the asm code, add it to prepare_exit_from_usermode and remove all
of the asm calls that are followed by prepare_exit_to_usermode.

LOCKDEP_SYS_EXIT now appears only in the syscall fast paths.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
---
 arch/x86/entry/common.c   | 2 ++
 arch/x86/entry/entry_32.S | 2 --
 arch/x86/entry/entry_64.S | 1 -
 3 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c
index 80dcc9261ca3..d94a60c16029 100644
--- a/arch/x86/entry/common.c
+++ b/arch/x86/entry/common.c
@@ -220,6 +220,8 @@ __visible void prepare_exit_to_usermode(struct pt_regs *regs)
 	if (WARN_ON(!irqs_disabled()))
 		local_irq_disable();
 
+	lockdep_sys_exit();
+
 	/*
 	 * In order to return to user mode, we need to have IRQs off with
 	 * none of _TIF_SIGPENDING, _TIF_NOTIFY_RESUME, _TIF_USER_RETURN_NOTIFY,
diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S
index b2909bf8cf70..a08ded481aba 100644
--- a/arch/x86/entry/entry_32.S
+++ b/arch/x86/entry/entry_32.S
@@ -255,7 +255,6 @@ ret_from_intr:
 	jb	resume_kernel			# not returning to v8086 or userspace
 
 ENTRY(resume_userspace)
-	LOCKDEP_SYS_EXIT
 	DISABLE_INTERRUPTS(CLBR_ANY)
 	TRACE_IRQS_OFF
 	movl	%esp, %eax
@@ -372,7 +371,6 @@ syscall_call:
 syscall_after_call:
 	movl	%eax, PT_EAX(%esp)		# store the return value
 syscall_exit:
-	LOCKDEP_SYS_EXIT
 	jmp	syscall_exit_work
 
 restore_all:
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index d3033183ed70..766254c2068b 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -557,7 +557,6 @@ ret_from_intr:
 	jz	retint_kernel
 
 	/* Interrupt came from user space */
-	LOCKDEP_SYS_EXIT_IRQ
 GLOBAL(retint_user)
 	mov	%rsp,%rdi
 	call	prepare_exit_to_usermode
-- 
2.4.3