[PATCH rcu 06/23] context_tracking: Rename context_tracking_user_enter/exit() to user_enter/exit_callable()

["Paul E. McKenney" <paulmck@kernel.org>]

From: Frederic Weisbecker <frederic@kernel.org>

context_tracking_user_enter() and context_tracking_user_exit() are
ASM callable versions of user_enter() and user_exit() for architectures
that didn't manage to check the context tracking static key from ASM.
Change those function names to better reflect their purpose.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Cc: Uladzislau Rezki <uladzislau.rezki@sony.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Nicolas Saenz Julienne <nsaenz@kernel.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Cc: Yu Liao <liaoyu15@huawei.com>
Cc: Phil Auld <pauld@redhat.com>
Cc: Paul Gortmaker<paul.gortmaker@windriver.com>
Cc: Alex Belits <abelits@marvell.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
 arch/arm/kernel/entry-header.S   |  8 ++++----
 arch/csky/kernel/entry.S         |  4 ++--
 arch/riscv/kernel/entry.S        |  6 +++---
 include/linux/context_tracking.h |  4 ++--
 kernel/context_tracking.c        | 28 +++++++++++++++++-----------
 5 files changed, 28 insertions(+), 22 deletions(-)

diff --git a/arch/arm/kernel/entry-header.S b/arch/arm/kernel/entry-header.S
index 5865621bf6912..95def2b38d1ca 100644
--- a/arch/arm/kernel/entry-header.S
+++ b/arch/arm/kernel/entry-header.S
@@ -369,10 +369,10 @@ ALT_UP_B(.L1_\@)
 #ifdef CONFIG_CONTEXT_TRACKING
 	.if	\save
 	stmdb   sp!, {r0-r3, ip, lr}
-	bl	context_tracking_user_exit
+	bl	user_exit_callable
 	ldmia	sp!, {r0-r3, ip, lr}
 	.else
-	bl	context_tracking_user_exit
+	bl	user_exit_callable
 	.endif
 #endif
 	.endm
@@ -381,10 +381,10 @@ ALT_UP_B(.L1_\@)
 #ifdef CONFIG_CONTEXT_TRACKING
 	.if	\save
 	stmdb   sp!, {r0-r3, ip, lr}
-	bl	context_tracking_user_enter
+	bl	user_enter_callable
 	ldmia	sp!, {r0-r3, ip, lr}
 	.else
-	bl	context_tracking_user_enter
+	bl	user_enter_callable
 	.endif
 #endif
 	.endm
diff --git a/arch/csky/kernel/entry.S b/arch/csky/kernel/entry.S
index a4ababf25e243..bc734d17c16f4 100644
--- a/arch/csky/kernel/entry.S
+++ b/arch/csky/kernel/entry.S
@@ -23,7 +23,7 @@
 	mfcr	a0, epsr
 	btsti	a0, 31
 	bt	1f
-	jbsr	context_tracking_user_exit
+	jbsr	user_exit_callable
 	ldw	a0, (sp, LSAVE_A0)
 	ldw	a1, (sp, LSAVE_A1)
 	ldw	a2, (sp, LSAVE_A2)
@@ -160,7 +160,7 @@ ret_from_exception:
 	cmpnei	r10, 0
 	bt	exit_work
 #ifdef CONFIG_CONTEXT_TRACKING
-	jbsr	context_tracking_user_enter
+	jbsr	user_enter_callable
 #endif
 1:
 #ifdef CONFIG_PREEMPTION
diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S
index 2e5b88ca11ce1..12f6bba57e335 100644
--- a/arch/riscv/kernel/entry.S
+++ b/arch/riscv/kernel/entry.S
@@ -112,11 +112,11 @@ _save_context:
 #endif
 
 #ifdef CONFIG_CONTEXT_TRACKING
-	/* If previous state is in user mode, call context_tracking_user_exit. */
+	/* If previous state is in user mode, call user_exit_callable(). */
 	li   a0, SR_PP
 	and a0, s1, a0
 	bnez a0, skip_context_tracking
-	call context_tracking_user_exit
+	call user_exit_callable
 skip_context_tracking:
 #endif
 
@@ -270,7 +270,7 @@ resume_userspace:
 	bnez s1, work_pending
 
 #ifdef CONFIG_CONTEXT_TRACKING
-	call context_tracking_user_enter
+	call user_enter_callable
 #endif
 
 	/* Save unwound kernel stack pointer in thread_info */
diff --git a/include/linux/context_tracking.h b/include/linux/context_tracking.h
index 773035124badb..69532cd18f72c 100644
--- a/include/linux/context_tracking.h
+++ b/include/linux/context_tracking.h
@@ -19,8 +19,8 @@ extern void __ct_user_exit(enum ctx_state state);
 
 extern void context_tracking_enter(enum ctx_state state);
 extern void context_tracking_exit(enum ctx_state state);
-extern void context_tracking_user_enter(void);
-extern void context_tracking_user_exit(void);
+extern void user_enter_callable(void);
+extern void user_exit_callable(void);
 
 static inline void user_enter(void)
 {
diff --git a/kernel/context_tracking.c b/kernel/context_tracking.c
index e36395598095e..9d4a872ca92c4 100644
--- a/kernel/context_tracking.c
+++ b/kernel/context_tracking.c
@@ -134,19 +134,22 @@ void context_tracking_enter(enum ctx_state state)
 NOKPROBE_SYMBOL(context_tracking_enter);
 EXPORT_SYMBOL_GPL(context_tracking_enter);
 
-/*
- * OBSOLETE:
- * This function should be noinstr but it unsafely calls local_irq_restore(),
- * involving illegal RCU uses through tracing and lockdep.
+/**
+ * user_enter_callable() - Unfortunate ASM callable version of user_enter() for
+ * 			   archs that didn't manage to check the context tracking
+ * 			   static key from low level code.
+ *
+ * This OBSOLETE function should be noinstr but it unsafely calls
+ * local_irq_restore(), involving illegal RCU uses through tracing and lockdep.
  * This is unlikely to be fixed as this function is obsolete. The preferred
  * way is to call user_enter_irqoff(). It should be the arch entry code
  * responsibility to call into context tracking with IRQs disabled.
  */
-void context_tracking_user_enter(void)
+void user_enter_callable(void)
 {
 	user_enter();
 }
-NOKPROBE_SYMBOL(context_tracking_user_enter);
+NOKPROBE_SYMBOL(user_enter_callable);
 
 /**
  * __ct_user_exit - Inform the context tracking that the CPU is
@@ -208,19 +211,22 @@ void context_tracking_exit(enum ctx_state state)
 NOKPROBE_SYMBOL(context_tracking_exit);
 EXPORT_SYMBOL_GPL(context_tracking_exit);
 
-/*
- * OBSOLETE:
- * This function should be noinstr but it unsafely calls local_irq_save(),
+/**
+ * user_exit_callable() - Unfortunate ASM callable version of user_exit() for
+ * 			  archs that didn't manage to check the context tracking
+ * 			  static key from low level code.
+ *
+ * This OBSOLETE function should be noinstr but it unsafely calls local_irq_save(),
  * involving illegal RCU uses through tracing and lockdep. This is unlikely
  * to be fixed as this function is obsolete. The preferred way is to call
  * user_exit_irqoff(). It should be the arch entry code responsibility to
  * call into context tracking with IRQs disabled.
  */
-void context_tracking_user_exit(void)
+void user_exit_callable(void)
 {
 	user_exit();
 }
-NOKPROBE_SYMBOL(context_tracking_user_exit);
+NOKPROBE_SYMBOL(user_exit_callable);
 
 void __init context_tracking_cpu_set(int cpu)
 {
-- 
2.31.1.189.g2e36527f23