[pypy-commit] stmgc c7-refactor: The tree data structure can explode when fed non-aligned addresses.

[arigo]

Author: Armin Rigo <arigo at tunes.org>
Branch: c7-refactor
Changeset: r867:e6d52f7b3ef1
Date: 2014-02-26 14:13 +0100
http://bitbucket.org/pypy/stmgc/changeset/e6d52f7b3ef1/

Log:	The tree data structure can explode when fed non-aligned addresses.
	Assert that they are aligned and fix the tests.

diff --git a/c7/stm/list.c b/c7/stm/list.c
--- a/c7/stm/list.c
+++ b/c7/stm/list.c
@@ -54,23 +54,23 @@
 static void tree_free(struct tree_s *tree)
 {
     free(tree->raw_start);
+    assert(memset(tree, 0xDD, sizeof(struct tree_s)));
     free(tree);
 }
 
 static void _tree_compress(struct tree_s *tree)
 {
-  wlog_t *item;
-  struct tree_s tree_copy;
-  memset(&tree_copy, 0, sizeof(struct tree_s));
+    wlog_t *item;
+    struct tree_s tree_copy;
+    memset(&tree_copy, 0, sizeof(struct tree_s));
 
-  TREE_LOOP_FORWARD(*tree, item)
-    {
-      tree_insert(&tree_copy, item->addr, item->val);
+    TREE_LOOP_FORWARD(*tree, item) {
+        tree_insert(&tree_copy, item->addr, item->val);
 
     } TREE_LOOP_END;
 
-  free(tree->raw_start);
-  *tree = tree_copy;
+    free(tree->raw_start);
+    *tree = tree_copy;
 }
 
 static wlog_t *_tree_find(char *entry, uintptr_t addr)
@@ -122,6 +122,7 @@
 static void tree_insert(struct tree_s *tree, uintptr_t addr, uintptr_t val)
 {
     assert(addr != 0);    /* the NULL key is reserved */
+    assert(!(addr & (sizeof(void *) - 1)));    /* the key must be aligned */
  retry:;
     wlog_t *wlog;
     uintptr_t key = addr;
@@ -129,6 +130,7 @@
     char *p = (char *)(tree->toplevel.items);
     char *entry;
     while (1) {
+        assert(shift < TREE_DEPTH_MAX * TREE_BITS);
         p += (key >> shift) & TREE_MASK;
         shift += TREE_BITS;
         entry = *(char **)p;
diff --git a/c7/stm/list.h b/c7/stm/list.h
--- a/c7/stm/list.h
+++ b/c7/stm/list.h
@@ -138,6 +138,7 @@
         continue;                                                       \
       if (((long)_entry) & 1)                                           \
         {  /* points to a further level: enter it */                    \
+          assert(_stackp - _stack < TREE_DEPTH_MAX);                    \
           _stackp->next = _next;                                        \
           _stackp->end = _end;                                          \
           _stackp++;                                                    \
diff --git a/c7/test/test_list.py b/c7/test/test_list.py
--- a/c7/test/test_list.py
+++ b/c7/test/test_list.py
@@ -65,34 +65,34 @@
 
 def test_tree_add():
     t = lib.tree_create()
-    lib.tree_insert(t, 23, 456)
-    for i in range(100):
-        assert lib.tree_contains(t, i) == (i == 23)
+    lib.tree_insert(t, 23000, 456)
+    for i in range(0, 100000, 1000):
+        assert lib.tree_contains(t, i) == (i == 23000)
     lib.tree_free(t)
 
 def test_tree_is_cleared():
     t = lib.tree_create()
     assert lib.tree_is_cleared(t)
-    lib.tree_insert(t, 23, 456)
+    lib.tree_insert(t, 23000, 456)
     assert not lib.tree_is_cleared(t)
     lib.tree_free(t)
 
 def test_tree_delete_item():
     t = lib.tree_create()
-    lib.tree_insert(t, 23, 456)
-    lib.tree_insert(t, 42, 34289)
+    lib.tree_insert(t, 23000, 456)
+    lib.tree_insert(t, 42000, 34289)
     assert not lib.tree_is_cleared(t)
-    assert lib.tree_contains(t, 23)
-    res = lib.tree_delete_item(t, 23)
+    assert lib.tree_contains(t, 23000)
+    res = lib.tree_delete_item(t, 23000)
     assert res
-    assert not lib.tree_contains(t, 23)
-    res = lib.tree_delete_item(t, 23)
+    assert not lib.tree_contains(t, 23000)
+    res = lib.tree_delete_item(t, 23000)
     assert not res
-    res = lib.tree_delete_item(t, 21)
+    res = lib.tree_delete_item(t, 21000)
     assert not res
     assert not lib.tree_is_cleared(t)
-    assert lib.tree_contains(t, 42)
-    res = lib.tree_delete_item(t, 42)
+    assert lib.tree_contains(t, 42000)
+    res = lib.tree_delete_item(t, 42000)
     assert res
     assert not lib.tree_is_cleared(t)   # not cleared, but still empty
     for i in range(100):
@@ -101,18 +101,18 @@
 
 def test_tree_walk():
     t = lib.tree_create()
-    lib.tree_insert(t, 23, 456)
-    lib.tree_insert(t, 42, 34289)
+    lib.tree_insert(t, 23000, 456)
+    lib.tree_insert(t, 42000, 34289)
     a = ffi.new("uintptr_t[10]")
     res = lib.test_tree_walk(t, a)
     assert res == 2
-    assert a[0] == 23
-    assert a[1] == 42
+    assert ((a[0] == 23000 and a[1] == 42000) or
+            (a[0] == 42000 and a[1] == 23000))
     lib.tree_free(t)
 
 def test_tree_walk_big():
     t = lib.tree_create()
-    values = [random.randrange(0, 1000000) for i in range(300)]
+    values = random.sample(xrange(0, 1000000, 8), 300)
     for x in values:
         lib.tree_insert(t, x, x)
     a = ffi.new("uintptr_t[1000]")