Add debug output when memory allocations fail

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5686 42af7a65-404d-4744-a932-0658087f49c3

1 files changed, 67 insertions, 41 deletions

diff --git a/nuttx/arch/mips/src/common/up_createstack.c b/nuttx/arch/mips/src/common/up_createstack.c
index f72701042..02cdd83d7 100644
--- a/nuttx/arch/mips/src/common/up_createstack.c
+++ b/nuttx/arch/mips/src/common/up_createstack.c
@@ -87,71 +87,97 @@
  * Name: up_create_stack
  *
  * Description:
- *   Allocate a stack for a new thread and setup
- *   up stack-related information in the TCB.
+ *   Allocate a stack for a new thread and setup up stack-related
+ *   information in the TCB.
  *
  *   The following TCB fields must be initialized:
- *   adj_stack_size: Stack size after adjustment for hardware,
- *     processor, etc.  This value is retained only for debug
- *     purposes.
+ *   adj_stack_size: Stack size after adjustment for hardware, processor,
+ *     etc.  This value is retained only for debug purposes.
  *   stack_alloc_ptr: Pointer to allocated stack
- *   adj_stack_ptr: Adjusted stack_alloc_ptr for HW.  The
- *     initial value of the stack pointer.
+ *   adj_stack_ptr: Adjusted stack_alloc_ptr for HW.  The initial value of
+ *     the stack pointer.
  *
- * Inputs:
+ * Input Parameters:
  *   tcb: The TCB of new task
- *   stack_size:  The requested stack size.  At least this much
- *     must be allocated.
+ *   stack_size:  The requested stack size.  At least this how much must be
+ *     allocated.
+ *
  ****************************************************************************/
 
 int up_create_stack(struct tcb_s *tcb, size_t stack_size)
 {
-  if (tcb->stack_alloc_ptr &&
-      tcb->adj_stack_size != stack_size)
+  /* Is there already a stack allocated of a different size? */
+
+  if (tcb->stack_alloc_ptr && tcb->adj_stack_size != stack_size)
     {
+      /* Yes.. free it */
+
       sched_free(tcb->stack_alloc_ptr);
       tcb->stack_alloc_ptr = NULL;
     }
 
-   if (!tcb->stack_alloc_ptr)
-     {
-#ifdef CONFIG_DEBUG
-       tcb->stack_alloc_ptr = (uint32_t*)kzalloc(stack_size);
+  /* Do we need to allocate a stack? */
+
+  if (!tcb->stack_alloc_ptr)
+    {
+      /* Allocate the stack.  If DEBUG is enabled (but not stack debug),
+       * then create a zeroed stack to make stack dumps easier to trace.
+       */
+
+#if defined(CONFIG_DEBUG) && !defined(CONFIG_DEBUG_STACK)
+      tcb->stack_alloc_ptr = (uint32_t *)kzalloc(stack_size);
 #else
-       tcb->stack_alloc_ptr = (uint32_t*)kmalloc(stack_size);
+      tcb->stack_alloc_ptr = (uint32_t *)kmalloc(stack_size);
+#endif
+#ifdef CONFIG_DEBUG
+      if (!tcb->stack_alloc_ptr)
+        {
+          sdbg("ERROR: Failed to allocate stack, size %d\n", stack_size);
+        }
 #endif
-     }
+    }
+
+  /* Did we successfully allocate a stack? */
+
+  if (tcb->stack_alloc_ptr)
+    {
+      size_t top_of_stack;
+      size_t size_of_stack;
+
+      /* Yes.. If stack debug is enabled, then fill the stack with a
+       * recognizable value that we can use later to test for high
+       * water marks.
+       */
 
-   if (tcb->stack_alloc_ptr)
-     {
-       size_t top_of_stack;
-       size_t size_of_stack;
+#if defined(CONFIG_DEBUG) && defined(CONFIG_DEBUG_STACK)
+      memset(tcb->stack_alloc_ptr, 0xaa, stack_size);
+#endif
 
-       /* MIPS uses a push-down stack:  the stack grows toward lower
-        * addresses in memory.  The stack pointer register points to the
-        * lowest, valid working address (the "top" of the stack).  Items on
-        * the stack are referenced as positive word offsets from sp.
-        */
+      /* MIPS uses a push-down stack:  the stack grows toward lower
+       * addresses in memory.  The stack pointer register points to the
+       * lowest, valid working address (the "top" of the stack).  Items on
+       * the stack are referenced as positive word offsets from sp.
+       */
 
-       top_of_stack = (uint32_t)tcb->stack_alloc_ptr + stack_size - 4;
+      top_of_stack = (uint32_t)tcb->stack_alloc_ptr + stack_size - 4;
 
-       /* The MIPS stack must be aligned at word (4 byte) boundaries; for
-        * floating point use, the stack must be aligned to 8-byte addresses.
-        * If necessary top_of_stack must be rounded down to the next
-        * boundary to meet these alignment requirements. 
-        */
+      /* The MIPS stack must be aligned at word (4 byte) boundaries; for
+       * floating point use, the stack must be aligned to 8-byte addresses.
+       * If necessary top_of_stack must be rounded down to the next
+       * boundary to meet these alignment requirements. 
+       */
 
-       top_of_stack = STACK_ALIGN_DOWN(top_of_stack);
-       size_of_stack = top_of_stack - (uint32_t)tcb->stack_alloc_ptr + 4;
+      top_of_stack = STACK_ALIGN_DOWN(top_of_stack);
+      size_of_stack = top_of_stack - (uint32_t)tcb->stack_alloc_ptr + 4;
 
-       /* Save the adjusted stack values in the struct tcb_s */
+      /* Save the adjusted stack values in the struct tcb_s */
 
-       tcb->adj_stack_ptr  = (uint32_t*)top_of_stack;
-       tcb->adj_stack_size = size_of_stack;
+      tcb->adj_stack_ptr  = (uint32_t*)top_of_stack;
+      tcb->adj_stack_size = size_of_stack;
 
-       up_ledon(LED_STACKCREATED);
-       return OK;
-     }
+      up_ledon(LED_STACKCREATED);
+      return OK;
+    }
 
    return ERROR;
 }