[PATCH 04/20] context_tracking: Rename context_tracking_user_enter/exit() to user_enter/exit_callable()

Frederic Weisbecker
2022-06-28T13:17:46Z

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: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
Tested-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
---
arch/arm/kernel/entry-header.S | 8 ++++----
arch/csky/kernel/entry.S | 4 ++--
arch/riscv/kernel/entry.S | 6 +++---
arch/xtensa/kernel/entry.S | 4 ++--
include/linux/context_tracking.h | 4 ++--
kernel/context_tracking.c | 28 +++++++++++++++++-----------
6 files changed, 30 insertions(+), 24 deletions(-)

diff --git a/arch/arm/kernel/entry-header.S b/arch/arm/kernel/entry-header.S
index 5865621bf691..95def2b38d1c 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 a4ababf25e24..bc734d17c16f 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 2e5b88ca11ce..12f6bba57e33 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/arch/xtensa/kernel/entry.S b/arch/xtensa/kernel/entry.S
index e3eae648ba2e..d72bcafae90c 100644
--- a/arch/xtensa/kernel/entry.S
+++ b/arch/xtensa/kernel/entry.S
@@ -458,7 +458,7 @@ KABI_W or a3, a3, a2
#ifdef CONFIG_CONTEXT_TRACKING
l32i abi_tmp0, a1, PT_PS
bbci.l abi_tmp0, PS_UM_BIT, 1f
- abi_call context_tracking_user_exit
+ abi_call user_exit_callable
1:
#endif

@@ -545,7 +545,7 @@ common_exception_return:

.Lexit_tif_loop_user:
#ifdef CONFIG_CONTEXT_TRACKING
- abi_call context_tracking_user_enter
+ abi_call user_enter_callable
#endif
#ifdef CONFIG_HAVE_HW_BREAKPOINT
_bbci.l abi_saved0, TIF_DB_DISABLED, 1f
diff --git a/include/linux/context_tracking.h b/include/linux/context_tracking.h
index 773035124bad..69532cd18f72 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 88c60ab39fbb..8f7dd5799bda 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)
{
--
2.25.1