[GitHub] [incubator-nuttx] davids5 commented on a change in pull request #1900: ARM stack fix: Same boundary calculation in do_stackcheck and stack_color.

[GitBox <gi...@apache.org>]

davids5 commented on a change in pull request #1900:
URL: https://github.com/apache/incubator-nuttx/pull/1900#discussion_r503387000



##########
File path: arch/arm/src/common/arm_checkstack.c
##########
@@ -55,17 +55,31 @@
 
 #ifdef CONFIG_STACK_COLORATION
 
+/****************************************************************************
+ * Pre-processor Macros
+ ****************************************************************************/
+
+/* 32bit alignment macros */
+
+#define INT32_ALIGN_MASK    (3)

Review comment:
       Can these live in a common file?

##########
File path: arch/arm/src/common/arm_checkstack.c
##########
@@ -78,34 +92,34 @@ static size_t do_stackcheck(uintptr_t alloc, size_t size);
  *
  ****************************************************************************/
 
-static size_t do_stackcheck(uintptr_t alloc, size_t size)
+static size_t do_stackcheck(FAR void *stackbase, size_t nbytes)
 {
-  FAR uintptr_t start;
-  FAR uintptr_t end;
+  uintptr_t start;
+  uintptr_t end;
   FAR uint32_t *ptr;
   size_t mark;
 
-  if (size == 0)
+  if (nbytes == 0)
     {
       return 0;
     }
 
-  /* Get aligned addresses of the top and bottom of the stack */
+  /* Take extra care that we do not check outside the stack boundaries */
 
-  start = alloc & ~3;
-  end   = (alloc + size + 3) & ~3;
+  start = INT32_ALIGN_UP((uintptr_t)stackbase);

Review comment:
       As discussed this has the potential masking tcb corruption. I feel it would be better to know that. But I will not insist on making it a condition on bring in the PR. 




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