kcov, usb: hide in_serving_softirq checks in __usb_hcd_giveback_urb

Done opencode in_serving_softirq() checks in in_serving_softirq() to avoid
cluttering the code, hide them in kcov helpers instead.

Fixes: aee9ddb1d371 ("kcov, usb: only collect coverage from __usb_hcd_giveback_urb in softirq")
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Link: https://lore.kernel.org/r/aeb430c5bb90b0ccdf1ec302c70831c1a47b9c45.1609876340.git.andreyknvl@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 60886a7464c3a95b029163c630f8914f97c66b03..ad5a0f405a75cd9c9a1cbb81ff071ec04281eef5 100644 (file)
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -1649,14 +1649,12 @@ static void __usb_hcd_giveback_urb(struct urb *urb)
        urb->status = status;
        /*
         * This function can be called in task context inside another remote
-        * coverage collection section, but KCOV doesn't support that kind of
+        * coverage collection section, but kcov doesn't support that kind of
         * recursion yet. Only collect coverage in softirq context for now.
         */
-       if (in_serving_softirq())
-               kcov_remote_start_usb((u64)urb->dev->bus->busnum);
+       kcov_remote_start_usb_softirq((u64)urb->dev->bus->busnum);
        urb->complete(urb);
-       if (in_serving_softirq())
-               kcov_remote_stop();
+       kcov_remote_stop_softirq();
 
        usb_anchor_resume_wakeups(anchor);
        atomic_dec(&urb->use_count);

diff --git a/include/linux/kcov.h b/include/linux/kcov.h
index a10e84707d820b54739f7dde0064c9334ac6c6e5..4e3037dc12048685390be4c91318646e69a4bb7d 100644 (file)
--- a/include/linux/kcov.h
+++ b/include/linux/kcov.h
@@ -52,6 +52,25 @@ static inline void kcov_remote_start_usb(u64 id)
        kcov_remote_start(kcov_remote_handle(KCOV_SUBSYSTEM_USB, id));
 }
 
+/*
+ * The softirq flavor of kcov_remote_*() functions is introduced as a temporary
+ * work around for kcov's lack of nested remote coverage sections support in
+ * task context. Adding suport for nested sections is tracked in:
+ * https://bugzilla.kernel.org/show_bug.cgi?id=210337
+ */
+
+static inline void kcov_remote_start_usb_softirq(u64 id)
+{
+       if (in_serving_softirq())
+               kcov_remote_start_usb(id);
+}
+
+static inline void kcov_remote_stop_softirq(void)
+{
+       if (in_serving_softirq())
+               kcov_remote_stop();
+}
+
 #else
 
 static inline void kcov_task_init(struct task_struct *t) {}
@@ -66,6 +85,8 @@ static inline u64 kcov_common_handle(void)
 }
 static inline void kcov_remote_start_common(u64 id) {}
 static inline void kcov_remote_start_usb(u64 id) {}
+static inline void kcov_remote_start_usb_softirq(u64 id) {}
+static inline void kcov_remote_stop_softirq(void) {}
 
 #endif /* CONFIG_KCOV */
 #endif /* _LINUX_KCOV_H */