misc/assert: add backtrace dump support for mutex hold task

Signed-off-by: fangpeina <fangpeina@xiaomi.com>

include/nuttx/mutex.h

@@ -49,6 +49,9 @@ struct mutex_s
 {
   sem_t sem;
   pid_t holder;
+#if CONFIG_LIBC_MUTEX_BACKTRACE > 0
+  FAR void *backtrace[CONFIG_LIBC_MUTEX_BACKTRACE];
+#endif
 };
 
 typedef struct mutex_s mutex_t;

libs/libc/misc/Kconfig

@@ -132,3 +132,10 @@ config LIBC_PATHBUFFER_MALLOC
 	default y
 	---help---
 		Enable malloc path buffer from the heap when pathbuffer is insufficient.
+
+config LIBC_MUTEX_BACKTRACE
+	int "The depth of mutex backtrace"
+	default 0
+	---help---
+		Config the depth of backtrace, dumping the backtrace of thread which
+		last acquired the mutex. Disable mutex backtrace by 0.

libs/libc/misc/lib_mutex.c

@@ -59,6 +59,35 @@ static bool nxmutex_is_reset(FAR mutex_t *mutex)
   return mutex->holder == NXMUTEX_RESET;
 }
 
+/****************************************************************************
+ * Name: nxmutex_add_backtrace
+ *
+ * Description:
+ *   This function add the backtrace of the holder of the mutex.
+ *
+ * Parameters:
+ *   mutex - mutex descriptor.
+ *
+ * Return Value:
+ *
+ ****************************************************************************/
+
+#if CONFIG_LIBC_MUTEX_BACKTRACE > 0
+static void nxmutex_add_backtrace(FAR mutex_t *mutex)
+{
+  int n;
+
+  n = sched_backtrace(mutex->holder, mutex->backtrace,
+                      CONFIG_LIBC_MUTEX_BACKTRACE, 0);
+  if (n < CONFIG_LIBC_MUTEX_BACKTRACE)
+    {
+      mutex->backtrace[n] = NULL;
+    }
+}
+#else
+#  define nxmutex_add_backtrace(mutex)
+#endif
+
 /****************************************************************************
  * Public Functions
  ****************************************************************************/
@@ -225,6 +254,7 @@ int nxmutex_lock(FAR mutex_t *mutex)
       if (ret >= 0)
         {
           mutex->holder = _SCHED_GETTID();
+          nxmutex_add_backtrace(mutex);
           break;
         }
       else if (ret != -EINTR && ret != -ECANCELED)
@@ -268,6 +298,8 @@ int nxmutex_trylock(FAR mutex_t *mutex)
     }
 
   mutex->holder = _SCHED_GETTID();
+  nxmutex_add_backtrace(mutex);
+
   return ret;
 }
 
@@ -319,6 +351,7 @@ int nxmutex_clocklock(FAR mutex_t *mutex, clockid_t clockid,
   if (ret >= 0)
     {
       mutex->holder = _SCHED_GETTID();
+      nxmutex_add_backtrace(mutex);
     }
 
   return ret;

sched/misc/assert.c

@@ -49,6 +49,7 @@
 
 #include <assert.h>
 #include <debug.h>
+#include <execinfo.h>
 #include <stdio.h>
 #include <stdint.h>
 #include <string.h>
@@ -170,10 +171,10 @@ static void stack_dump(uintptr_t sp, uintptr_t stack_top)
 }
 
 /****************************************************************************
- * Name: dump_stack
+ * Name: dump_stackinfo
  ****************************************************************************/
 
-static void dump_stack(FAR const char *tag, uintptr_t sp,
+static void dump_stackinfo(FAR const char *tag, uintptr_t sp,
                            uintptr_t base, size_t size, size_t used)
 {
   uintptr_t top = base + size;
@@ -272,7 +273,7 @@ static void dump_stacks(FAR struct tcb_s *rtcb, uintptr_t sp)
 #if CONFIG_ARCH_INTERRUPTSTACK > 0
   if (intstack_sp != 0 || force)
     {
-      dump_stack("IRQ",
+      dump_stackinfo("IRQ",
                      intstack_sp,
                      intstack_base,
                      intstack_size,
@@ -298,18 +299,17 @@ static void dump_stacks(FAR struct tcb_s *rtcb, uintptr_t sp)
 #ifdef CONFIG_ARCH_KERNEL_STACK
   if (kernelstack_sp != 0 || force)
     {
-      dump_stack("Kernel",
+      dump_stackinfo("Kernel",
                      kernelstack_sp,
                      kernelstack_base,
                      kernelstack_size,
-                 0
+                     0);
-                );
     }
 #endif
 
   if (tcbstack_sp != 0 || force)
     {
-      dump_stack("User",
+      dump_stackinfo("User",
                      tcbstack_sp,
                      tcbstack_base,
                      tcbstack_size,
@@ -531,6 +531,27 @@ static void dump_tasks(void)
 #endif
 }
 
+/****************************************************************************
+ * Name: dump_lockholder
+ ****************************************************************************/
+
+#if CONFIG_LIBC_MUTEX_BACKTRACE > 0
+static void dump_lockholder(pid_t tid)
+{
+  char buf[CONFIG_LIBC_MUTEX_BACKTRACE * BACKTRACE_PTR_FMT_WIDTH + 1] = "";
+  FAR mutex_t *mutex;
+
+  mutex = (FAR mutex_t *)nxsched_get_tcb(tid)->waitobj;
+
+  backtrace_format(buf, sizeof(buf), mutex->backtrace,
+                   CONFIG_LIBC_MUTEX_BACKTRACE);
+
+  _alert("Mutex holder(%d) backtrace:%s\n", mutex->holder, buf);
+}
+#else
+#  define dump_lockholder(tid)
+#endif
+
 /****************************************************************************
  * Name: dump_deadlock
  ****************************************************************************/
@@ -546,11 +567,12 @@ static void dump_deadlock(void)
       _alert("Deadlock detected\n");
       while (i-- > 0)
         {
-#ifdef CONFIG_SCHED_BACKTRACE
+#  ifdef CONFIG_SCHED_BACKTRACE
           sched_dumpstack(deadlock[i]);
-#else
+          dump_lockholder(deadlock[i]);
+#  else
           _alert("deadlock pid: %d\n", deadlock[i]);
-#endif
+#  endif
         }
     }
 }