From: Rik van Riel <r...@redhat.com>

Add the expected ctx_state as a parameter to context_tracking_user_enter
and context_tracking_user_exit, allowing the same functions to not just
track kernel <> user space switching, but also kernel <> guest transitions.

Catalin, Will: this patch and the next one break ARM, entry.S needs to be
modified to add the IN_USER parameter to context_tracking_enter & _exit.

Cc: catalin.mari...@arm.com
Cc: will.dea...@arm.com
Signed-off-by: Rik van Riel <r...@redhat.com>
---
 include/linux/context_tracking.h | 12 ++++++------
 kernel/context_tracking.c        | 10 +++++-----
 2 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/include/linux/context_tracking.h b/include/linux/context_tracking.h
index 37b81bd51ec0..bd9f000fc98d 100644
--- a/include/linux/context_tracking.h
+++ b/include/linux/context_tracking.h
@@ -10,21 +10,21 @@
 #ifdef CONFIG_CONTEXT_TRACKING
 extern void context_tracking_cpu_set(int cpu);
 
-extern void context_tracking_user_enter(void);
-extern void context_tracking_user_exit(void);
+extern void context_tracking_user_enter(enum ctx_state state);
+extern void context_tracking_user_exit(enum ctx_state state);
 extern void __context_tracking_task_switch(struct task_struct *prev,
                                           struct task_struct *next);
 
 static inline void user_enter(void)
 {
        if (context_tracking_is_enabled())
-               context_tracking_user_enter();
+               context_tracking_user_enter(IN_USER);
 
 }
 static inline void user_exit(void)
 {
        if (context_tracking_is_enabled())
-               context_tracking_user_exit();
+               context_tracking_user_exit(IN_USER);
 }
 
 static inline enum ctx_state exception_enter(void)
@@ -35,7 +35,7 @@ static inline enum ctx_state exception_enter(void)
                return 0;
 
        prev_ctx = this_cpu_read(context_tracking.state);
-       context_tracking_user_exit();
+       context_tracking_user_exit(prev_ctx);
 
        return prev_ctx;
 }
@@ -44,7 +44,7 @@ static inline void exception_exit(enum ctx_state prev_ctx)
 {
        if (context_tracking_is_enabled()) {
                if (prev_ctx == IN_USER)
-                       context_tracking_user_enter();
+                       context_tracking_user_enter(prev_ctx);
        }
 }
 
diff --git a/kernel/context_tracking.c b/kernel/context_tracking.c
index 937ecdfdf258..4c010787c9ec 100644
--- a/kernel/context_tracking.c
+++ b/kernel/context_tracking.c
@@ -47,7 +47,7 @@ void context_tracking_cpu_set(int cpu)
  * to execute won't use any RCU read side critical section because this
  * function sets RCU in extended quiescent state.
  */
-void context_tracking_user_enter(void)
+void context_tracking_user_enter(enum ctx_state state)
 {
        unsigned long flags;
 
@@ -75,7 +75,7 @@ void context_tracking_user_enter(void)
        WARN_ON_ONCE(!current->mm);
 
        local_irq_save(flags);
-       if ( __this_cpu_read(context_tracking.state) != IN_USER) {
+       if ( __this_cpu_read(context_tracking.state) != state) {
                if (__this_cpu_read(context_tracking.active)) {
                        trace_user_enter(0);
                        /*
@@ -101,7 +101,7 @@ void context_tracking_user_enter(void)
                 * OTOH we can spare the calls to vtime and RCU when 
context_tracking.active
                 * is false because we know that CPU is not tickless.
                 */
-               __this_cpu_write(context_tracking.state, IN_USER);
+               __this_cpu_write(context_tracking.state, state);
        }
        local_irq_restore(flags);
 }
@@ -118,7 +118,7 @@ NOKPROBE_SYMBOL(context_tracking_user_enter);
  * This call supports re-entrancy. This way it can be called from any exception
  * handler without needing to know if we came from userspace or not.
  */
-void context_tracking_user_exit(void)
+void context_tracking_user_exit(enum ctx_state state)
 {
        unsigned long flags;
 
@@ -129,7 +129,7 @@ void context_tracking_user_exit(void)
                return;
 
        local_irq_save(flags);
-       if (__this_cpu_read(context_tracking.state) == IN_USER) {
+       if (__this_cpu_read(context_tracking.state) == state) {
                if (__this_cpu_read(context_tracking.active)) {
                        /*
                         * We are going to run code that may use RCU. Inform
-- 
1.9.3

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