Assert the Matter lock is held in non-threadsafe SystemLayer methods. (…

…#26180)

ScheduleWork uses timers, and timers access a timer list member that is not
protected against data races in any way.

src/system/SystemLayer.h

@@ -96,7 +96,8 @@ class DLL_EXPORT Layer
 
     /**
      * @brief
-     *   This method starts a one-shot timer.
+     *   This method starts a one-shot timer.  This method must be called while in the Matter context (from
+     *   the Matter event loop, or while holding the Matter stack lock).
      *
      *   @note
      *       Only a single timer is allowed to be started with the same @a aComplete and @a aAppState
@@ -114,8 +115,9 @@ class DLL_EXPORT Layer
     virtual CHIP_ERROR StartTimer(Clock::Timeout aDelay, TimerCompleteCallback aComplete, void * aAppState) = 0;
 
     /**
-     * @brief
-     *   This method cancels a one-shot timer, started earlier through @p StartTimer().
+     * @brief This method cancels a one-shot timer, started earlier through @p StartTimer().  This method must
+     *        be called while in the Matter context (from the Matter event loop, or while holding the Matter
+     *        stack lock).
      *
      *   @note
      *       The cancellation could fail silently if the timer specified by the combination of the callback
@@ -129,7 +131,9 @@ class DLL_EXPORT Layer
 
     /**
      * @brief
-     *   Schedules a function with a signature identical to `OnCompleteFunct` to be run as soon as possible in the CHIP context.
+     *   Schedules a function with a signature identical to `OnCompleteFunct` to be run as soon as possible in the Matter context.
+     *   This must only be called when already in the Matter context (from the Matter event loop, or while holding the Matter
+     *   stack lock).
      *
      * @param[in] aComplete     A pointer to a callback function to be called when this timer fires.
      * @param[in] aAppState     A pointer to an application state object to be passed to the callback function as argument.

src/system/SystemLayerImplFreeRTOS.cpp

@@ -22,6 +22,7 @@
  */
 
 #include <lib/support/CodeUtils.h>
+#include <platform/LockTracker.h>
 #include <system/PlatformEventSupport.h>
 #include <system/SystemFaultInjection.h>
 #include <system/SystemLayer.h>
@@ -51,6 +52,8 @@ void LayerImplFreeRTOS::Shutdown()
 
 CHIP_ERROR LayerImplFreeRTOS::StartTimer(Clock::Timeout delay, TimerCompleteCallback onComplete, void * appState)
 {
+    assertChipStackLockedByCurrentThread();
+
     VerifyOrReturnError(mLayerState.IsInitialized(), CHIP_ERROR_INCORRECT_STATE);
 
     CHIP_SYSTEM_FAULT_INJECT(FaultInjection::kFault_TimeoutImmediate, delay = Clock::kZero);
@@ -75,6 +78,8 @@ CHIP_ERROR LayerImplFreeRTOS::StartTimer(Clock::Timeout delay, TimerCompleteCall
 
 void LayerImplFreeRTOS::CancelTimer(TimerCompleteCallback onComplete, void * appState)
 {
+    assertChipStackLockedByCurrentThread();
+
     VerifyOrReturn(mLayerState.IsInitialized());
 
     TimerList::Node * timer = mTimerList.Remove(onComplete, appState);
@@ -86,6 +91,8 @@ void LayerImplFreeRTOS::CancelTimer(TimerCompleteCallback onComplete, void * app
 
 CHIP_ERROR LayerImplFreeRTOS::ScheduleWork(TimerCompleteCallback onComplete, void * appState)
 {
+    assertChipStackLockedByCurrentThread();
+
     VerifyOrReturnError(mLayerState.IsInitialized(), CHIP_ERROR_INCORRECT_STATE);
 
     // Ideally we would not use a timer here at all, but if we try to just

src/system/SystemLayerImplSelect.cpp

@@ -122,6 +122,8 @@ void LayerImplSelect::Signal()
 
 CHIP_ERROR LayerImplSelect::StartTimer(Clock::Timeout delay, TimerCompleteCallback onComplete, void * appState)
 {
+    assertChipStackLockedByCurrentThread();
+
     VerifyOrReturnError(mLayerState.IsInitialized(), CHIP_ERROR_INCORRECT_STATE);
 
     CHIP_SYSTEM_FAULT_INJECT(FaultInjection::kFault_TimeoutImmediate, delay = System::Clock::kZero);
@@ -167,6 +169,8 @@ CHIP_ERROR LayerImplSelect::StartTimer(Clock::Timeout delay, TimerCompleteCallba
 
 void LayerImplSelect::CancelTimer(TimerCompleteCallback onComplete, void * appState)
 {
+    assertChipStackLockedByCurrentThread();
+
     VerifyOrReturn(mLayerState.IsInitialized());
 
     TimerList::Node * timer = mTimerList.Remove(onComplete, appState);
@@ -194,6 +198,8 @@ void LayerImplSelect::CancelTimer(TimerCompleteCallback onComplete, void * appSt
 
 CHIP_ERROR LayerImplSelect::ScheduleWork(TimerCompleteCallback onComplete, void * appState)
 {
+    assertChipStackLockedByCurrentThread();
+
     VerifyOrReturnError(mLayerState.IsInitialized(), CHIP_ERROR_INCORRECT_STATE);
 
 #if CHIP_SYSTEM_CONFIG_USE_DISPATCH