In the kernel build, allocate the stacks for kernel threads from the kernel heap so that they are protected from medddling by the applications

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5766 42af7a65-404d-4744-a932-0658087f49c3

3 files changed, 59 insertions, 13 deletions

diff --git a/nuttx/arch/z80/src/common/up_createstack.c b/nuttx/arch/z80/src/common/up_createstack.c
index 1e47b09bd..a36a8aa7b 100644
--- a/nuttx/arch/z80/src/common/up_createstack.c
+++ b/nuttx/arch/z80/src/common/up_createstack.c
@@ -101,30 +101,52 @@
 
 int up_create_stack(FAR struct tcb_s *tcb, size_t stack_size, uint8_t ttype)
 {
-  /* Is there already a stack allocated of a different size? */
+  /* Is there already a stack allocated of a different size?  Because of
+   * alignment issues, stack_size might erroneously appear to be of a
+   * different size.  Fortunately, this is not a critical operation.
+   */
 
   if (tcb->stack_alloc_ptr && tcb->adj_stack_size != stack_size)
     {
-      /* Yes.. free it */
+      /* Yes.. Release the old stack */
 
-      sched_ufree(tcb->stack_alloc_ptr);
-      tcb->stack_alloc_ptr = NULL;
+      up_release_stack(tcb, ttype);
     }
 
-  /* Do we need to allocate a stack? */
-
+  /* Do we need to allocate a new 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_NUTTX_KERNEL) && defined(CONFIG_MM_KERNEL_HEAP)
+      /* Use the kernel allocator if this is a kernel thread */
+
+      if (ttype == TCB_FLAG_TTYPE_KERNEL)
+        {
 #if defined(CONFIG_DEBUG) && !defined(CONFIG_DEBUG_STACK)
-      tcb->stack_alloc_ptr = (uint32_t *)kuzalloc(stack_size);
+          tcb->stack_alloc_ptr = (uint32_t *)kzalloc(stack_size);
 #else
-      tcb->stack_alloc_ptr = (uint32_t *)kumalloc(stack_size);
+          tcb->stack_alloc_ptr = (uint32_t *)kmalloc(stack_size);
 #endif
+        }
+      else
+#endif
+        {
+          /* Use the user-space allocator if this is a task or pthread */
+
+#if defined(CONFIG_DEBUG) && !defined(CONFIG_DEBUG_STACK)
+          tcb->stack_alloc_ptr = (uint32_t *)kuzalloc(stack_size);
+#else
+          tcb->stack_alloc_ptr = (uint32_t *)kumalloc(stack_size);
+#endif
+        }
+
 #ifdef CONFIG_DEBUG
+      /* Was the allocation successful? */
+
       if (!tcb->stack_alloc_ptr)
         {
           sdbg("ERROR: Failed to allocate stack, size %d\n", stack_size);
diff --git a/nuttx/arch/z80/src/common/up_releasestack.c b/nuttx/arch/z80/src/common/up_releasestack.c
index beefc4744..92c7bbd0a 100644
--- a/nuttx/arch/z80/src/common/up_releasestack.c
+++ b/nuttx/arch/z80/src/common/up_releasestack.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  * common/up_releasestack.c
  *
- *   Copyright (C) 2007-2009 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2009, 2013 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -91,11 +91,31 @@
 
 void up_release_stack(FAR struct tcb_s *dtcb, uint8_t ttype)
 {
+  /* Is there a stack allocated? */
+
   if (dtcb->stack_alloc_ptr)
     {
-      sched_ufree(dtcb->stack_alloc_ptr);
+#if defined(CONFIG_NUTTX_KERNEL) && defined(CONFIG_MM_KERNEL_HEAP)
+      /* Use the kernel allocator if this is a kernel thread */
+
+      if (ttype == TCB_FLAG_TTYPE_KERNEL)
+        {
+          sched_kfree(dtcb->stack_alloc_ptr);
+        }
+      else
+#endif
+        {
+          /* Use the user-space allocator if this is a task or pthread */
+
+          sched_ufree(dtcb->stack_alloc_ptr);
+        }
+
+      /* Mark the stack freed */
+
       dtcb->stack_alloc_ptr = NULL;
     }
 
+  /* The size of the allocated stack is now zero */
+
   dtcb->adj_stack_size = 0;
 }
diff --git a/nuttx/arch/z80/src/common/up_usestack.c b/nuttx/arch/z80/src/common/up_usestack.c
index 8d322e705..095b4f5d5 100644
--- a/nuttx/arch/z80/src/common/up_usestack.c
+++ b/nuttx/arch/z80/src/common/up_usestack.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  * arch/z80/src/common/up_usestack.c
  *
- *   Copyright (C) 2007-2009 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2009, 2013 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -93,12 +93,16 @@ int up_use_stack(struct tcb_s *tcb, void *stack, size_t stack_size)
   size_t top_of_stack;
   size_t size_of_stack;
 
+  /* Is there already a stack allocated? */
+
   if (tcb->stack_alloc_ptr)
     {
-      sched_ufree(tcb->stack_alloc_ptr);
+      /* Yes.. Release the old stack allocation */
+
+      up_release_stack(tcb, tcb->flags & TCB_FLAG_TTYPE_MASK);
     }
 
-  /* Save the stack allocation */
+  /* Save the new stack allocation */
 
   tcb->stack_alloc_ptr = stack;