sanity: Don't mark memory uninit in sanitize_{alloc,free}()

We might want to change the size of an allocated region without changing
which bytes are initialized.

1 files changed, 34 insertions, 10 deletions

diff --git a/tests/alloc.c b/tests/alloc.c
index 5fc934b..4aae515 100644
--- a/tests/alloc.c
+++ b/tests/alloc.c
@@ -10,6 +10,27 @@
 #include <stdlib.h>
 #include <stdint.h>
 
+struct flexible {
+	alignas(64) int foo[8];
+	int bar[];
+};
+
+/** Check varena_realloc() poisoning for a size combination. */
+static struct flexible *check_varena_realloc(struct varena *varena, struct flexible *flexy, size_t old_count, size_t new_count) {
+	flexy = varena_realloc(varena, flexy, old_count, new_count);
+	bfs_everify(flexy);
+
+	for (size_t i = 0; i < new_count; ++i) {
+		if (i < old_count) {
+			bfs_check(flexy->bar[i] == (int)i);
+		} else {
+			flexy->bar[i] = i;
+		}
+	}
+
+	return flexy;
+}
+
 void check_alloc(void) {
 	// Check aligned allocation
 	void *ptr;
@@ -20,21 +41,14 @@ void check_alloc(void) {
 	free(ptr);
 
 	// Check sizeof_flex()
-	struct flexible {
-		alignas(64) int foo[8];
-		int bar[];
-	};
 	bfs_check(sizeof_flex(struct flexible, bar, 0) >= sizeof(struct flexible));
 	bfs_check(sizeof_flex(struct flexible, bar, 16) % alignof(struct flexible) == 0);
 
-	size_t too_many = SIZE_MAX / sizeof(int) + 1;
+	// volatile to suppress -Walloc-size-larger-than
+	volatile size_t too_many = SIZE_MAX / sizeof(int) + 1;
 	bfs_check(sizeof_flex(struct flexible, bar, too_many) == align_floor(alignof(struct flexible), SIZE_MAX));
 
 	// Make sure we detect allocation size overflows
-#if __GNUC__ && !__clang__
-#  pragma GCC diagnostic ignored "-Walloc-size-larger-than="
-#endif
-
 	bfs_check(ALLOC_ARRAY(int, too_many) == NULL && errno == EOVERFLOW);
 	bfs_check(ZALLOC_ARRAY(int, too_many) == NULL && errno == EOVERFLOW);
 	bfs_check(ALLOC_FLEX(struct flexible, bar, too_many) == NULL && errno == EOVERFLOW);
@@ -45,10 +59,20 @@ void check_alloc(void) {
 	VARENA_INIT(&varena, struct flexible, bar);
 
 	for (size_t i = 0; i < 256; ++i) {
-		bfs_verify(varena_alloc(&varena, i));
+		bfs_everify(varena_alloc(&varena, i));
 		struct arena *arena = &varena.arenas[varena.narenas - 1];
 		bfs_check(arena->size >= sizeof_flex(struct flexible, bar, i));
 	}
 
+	// Check varena_realloc() (un)poisoning
+	struct flexible *flexy = varena_alloc(&varena, 160);
+	bfs_everify(flexy);
+
+	flexy = check_varena_realloc(&varena, flexy, 0, 160);
+	flexy = check_varena_realloc(&varena, flexy, 160, 192);
+	flexy = check_varena_realloc(&varena, flexy, 192, 160);
+	flexy = check_varena_realloc(&varena, flexy, 160, 320);
+	flexy = check_varena_realloc(&varena, flexy, 320, 96);
+
 	varena_destroy(&varena);
 }