vlib: map thread stack instead of allocating them from heap

Heap may use different page sizes so we will not be able to create
stack protection page.

Type: improvement
Change-Id: Ibb35c9f0a151c464ee0167d17f2bd773ef6f530b
Signed-off-by: Damjan Marion <damarion@cisco.com>

2 files changed, 18 insertions, 30 deletions

diff --git a/src/vlib/node.c b/src/vlib/node.c
index 169c67b0888..00660373607 100644
--- a/src/vlib/node.c
+++ b/src/vlib/node.c
@@ -295,7 +295,6 @@ register_node (vlib_main_t * vm, vlib_node_registration_t * r)
 {
   vlib_node_main_t *nm = &vm->node_main;
   vlib_node_t *n;
-  u32 page_size = clib_mem_get_page_size ();
   int i;
 
   if (CLIB_DEBUG > 0)
@@ -409,36 +408,26 @@ register_node (vlib_main_t * vm, vlib_node_registration_t * r)
     if (n->type == VLIB_NODE_TYPE_PROCESS)
       {
 	vlib_process_t *p;
-	void *map;
-	uword log2_n_stack_bytes, stack_bytes;
-	int mmap_flags = MAP_PRIVATE | MAP_ANONYMOUS;
+	uword log2_n_stack_bytes;
 
 	log2_n_stack_bytes = clib_max (r->process_log2_n_stack_bytes,
 				       VLIB_PROCESS_LOG2_STACK_SIZE);
 	log2_n_stack_bytes = clib_max (log2_n_stack_bytes,
-				       min_log2 (page_size));
+				       clib_mem_get_log2_page_size ());
 
 	p = clib_mem_alloc_aligned (sizeof (p[0]), CLIB_CACHE_LINE_BYTES);
 	clib_memset (p, 0, sizeof (p[0]));
 	p->log2_n_stack_bytes = log2_n_stack_bytes;
 
-	stack_bytes = 1ULL << log2_n_stack_bytes;
-	/* map stack size + 2 extra guard pages */
-	map = mmap (0, stack_bytes + page_size, PROT_READ | PROT_WRITE,
-		    mmap_flags, -1, 0);
+	p->stack = clib_mem_vm_map_stack (1ULL << log2_n_stack_bytes,
+					  CLIB_MEM_PAGE_SZ_DEFAULT,
+					  "process stack: %U",
+					  format_vlib_node_name, vm,
+					  n->index);
 
-	if (map == MAP_FAILED)
+	if (p->stack == CLIB_MEM_VM_MAP_FAILED)
 	  clib_panic ("failed to allocate process stack (%d bytes)",
-		      stack_bytes);
-
-	/* skip the guard page */
-	p->stack = map + page_size;
-
-	mmap_flags |= MAP_FIXED;
-	map = mmap (map, page_size, PROT_NONE, mmap_flags, -1, 0);
-
-	if (map == MAP_FAILED)
-	  clib_unix_warning ("failed to create stack guard page");
+		      1ULL << log2_n_stack_bytes);
 
 	/* Process node's runtime index is really index into process
 	   pointer vector. */
diff --git a/src/vlib/unix/main.c b/src/vlib/unix/main.c
index 95aeecf2da2..9dde666bbef 100644
--- a/src/vlib/unix/main.c
+++ b/src/vlib/unix/main.c
@@ -666,18 +666,17 @@ thread0 (uword arg)
 u8 *
 vlib_thread_stack_init (uword thread_index)
 {
+  void *stack;
   ASSERT (thread_index < vec_len (vlib_thread_stacks));
-  vlib_thread_stacks[thread_index] = clib_mem_alloc_aligned
-    (VLIB_THREAD_STACK_SIZE, clib_mem_get_page_size ());
+  stack = clib_mem_vm_map_stack (VLIB_THREAD_STACK_SIZE,
+				 CLIB_MEM_PAGE_SZ_DEFAULT,
+				 "thread stack: thread %u", thread_index);
 
-  /*
-   * Disallow writes to the bottom page of the stack, to
-   * catch stack overflows.
-   */
-  if (mprotect (vlib_thread_stacks[thread_index],
-		clib_mem_get_page_size (), PROT_READ) < 0)
-    clib_unix_warning ("thread stack");
-  return vlib_thread_stacks[thread_index];
+  if (stack == CLIB_MEM_VM_MAP_FAILED)
+    clib_panic ("failed to allocate thread %u stack", thread_index);
+
+  vlib_thread_stacks[thread_index] = stack;
+  return stack;
 }
 
 int