Merge tag 'usb-6.10-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb

Pull USB / Thunderbolt fixes from Greg KH:
 "Here are some small USB and Thunderbolt driver fixes for 6.10-rc4.
  Included in here are:

   - thunderbolt debugfs bugfix

   - USB typec bugfixes

   - kcov usb bugfix

   - xhci bugfixes

   - usb-storage bugfix

   - dt-bindings bugfix

   - cdc-wdm log message spam bugfix

  All of these, except for the last cdc-wdm log level change, have been
  in linux-next for a while with no reported problems. The cdc-wdm
  bugfix has been tested by syzbot and proved to fix the reported cpu
  lockup issues when the log is constantly spammed by a broken device"

* tag 'usb-6.10-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  USB: class: cdc-wdm: Fix CPU lockup caused by excessive log messages
  xhci: Handle TD clearing for multiple streams case
  xhci: Apply broken streams quirk to Etron EJ188 xHCI host
  xhci: Apply reset resume quirk to Etron EJ188 xHCI host
  xhci: Set correct transferred length for cancelled bulk transfers
  usb-storage: alauda: Check whether the media is initialized
  usb: typec: ucsi: Ack also failed Get Error commands
  kcov, usb: disable interrupts in kcov_remote_start_usb_softirq
  dt-bindings: usb: realtek,rts5411: Add missing "additionalProperties" on child nodes
  usb: typec: tcpm: Ignore received Hard Reset in TOGGLING state
  usb: typec: tcpm: fix use-after-free case in tcpm_register_source_caps
  USB: xen-hcd: Traverse host/ when CONFIG_USB_XEN_HCD is selected
  usb: typec: ucsi: glink: increase max ports for x1e80100
  Revert "usb: chipidea: move ci_ulpi_init after the phy initialization"
  thunderbolt: debugfs: Fix margin debugfs node creation condition

1 files changed, 38 insertions, 9 deletions

diff --git a/include/linux/kcov.h b/include/linux/kcov.h
index b851ba415e03..1068a7318d89 100644
--- a/include/linux/kcov.h
+++ b/include/linux/kcov.h
@@ -55,21 +55,47 @@ static inline void kcov_remote_start_usb(u64 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 support for nested sections is tracked in:
- * https://bugzilla.kernel.org/show_bug.cgi?id=210337
+ * workaround for KCOV's lack of nested remote coverage sections support.
+ *
+ * Adding support is tracked in https://bugzilla.kernel.org/show_bug.cgi?id=210337.
+ *
+ * kcov_remote_start_usb_softirq():
+ *
+ * 1. Only collects coverage when called in the softirq context. This allows
+ *    avoiding nested remote coverage collection sections in the task context.
+ *    For example, USB/IP calls usb_hcd_giveback_urb() in the task context
+ *    within an existing remote coverage collection section. Thus, KCOV should
+ *    not attempt to start collecting coverage within the coverage collection
+ *    section in __usb_hcd_giveback_urb() in this case.
+ *
+ * 2. Disables interrupts for the duration of the coverage collection section.
+ *    This allows avoiding nested remote coverage collection sections in the
+ *    softirq context (a softirq might occur during the execution of a work in
+ *    the BH workqueue, which runs with in_serving_softirq() > 0).
+ *    For example, usb_giveback_urb_bh() runs in the BH workqueue with
+ *    interrupts enabled, so __usb_hcd_giveback_urb() might be interrupted in
+ *    the middle of its remote coverage collection section, and the interrupt
+ *    handler might invoke __usb_hcd_giveback_urb() again.
  */
 
-static inline void kcov_remote_start_usb_softirq(u64 id)
+static inline unsigned long kcov_remote_start_usb_softirq(u64 id)
 {
-	if (in_serving_softirq())
+	unsigned long flags = 0;
+
+	if (in_serving_softirq()) {
+		local_irq_save(flags);
 		kcov_remote_start_usb(id);
+	}
+
+	return flags;
 }
 
-static inline void kcov_remote_stop_softirq(void)
+static inline void kcov_remote_stop_softirq(unsigned long flags)
 {
-	if (in_serving_softirq())
+	if (in_serving_softirq()) {
 		kcov_remote_stop();
+		local_irq_restore(flags);
+	}
 }
 
 #ifdef CONFIG_64BIT
@@ -103,8 +129,11 @@ 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) {}
+static inline unsigned long kcov_remote_start_usb_softirq(u64 id)
+{
+	return 0;
+}
+static inline void kcov_remote_stop_softirq(unsigned long flags) {}
 
 #endif /* CONFIG_KCOV */
 #endif /* _LINUX_KCOV_H */