test: add coverage for untested allocator error paths

test/Makefile

@@ -64,6 +64,7 @@ EXECUTABLES := \
     invalid_aligned_sized_delete_small \
     aligned_sized_delete_large \
     invalid_aligned_sized_delete_large \
+    invalid_free_aligned_sized_small \
     free_sized_small \
     free_sized_large \
     unaligned_malloc_usable_size_small \
@@ -74,6 +75,7 @@ EXECUTABLES := \
     malloc_object_size_zero \
     invalid_malloc_object_size_small \
     invalid_malloc_object_size_small_quarantine \
+    invalid_malloc_object_size_small_canary \
     impossibly_large_malloc \
     realloc_init \
     calloc_overflow \

test/invalid_free_aligned_sized_small.c

@@ -0,0 +1,8 @@
+#include "../include/h_malloc.h"
+
+int main(void) {
+    void *p = malloc(16);
+    // alignment 3 is not a power of two
+    free_aligned_sized(p, 3, 16);
+    return 0;
+}

test/invalid_malloc_object_size_small_canary.c

@@ -0,0 +1,11 @@
+#include <stdlib.h>
+
+#include "test_util.h"
+
+size_t malloc_object_size(void *ptr);
+
+OPTNONE int main(void) {
+    char *p = malloc(16);
+    // offset past the usable size, into the slab canary region
+    return (int)malloc_object_size(p + 25);
+}

test/test_smc.py

@@ -51,6 +51,13 @@ def test_invalid_aligned_sized_delete_large(self):
         self.assertEqual(stderr.decode(
             "utf-8"), "fatal allocator error: sized deallocation mismatch (large)\n")
 
+    def test_invalid_free_aligned_sized_small(self):
+        _stdout, stderr, returncode = self.run_test(
+            "invalid_free_aligned_sized_small")
+        self.assertEqual(returncode, -6)
+        self.assertEqual(stderr.decode(
+            "utf-8"), "fatal allocator error: invalid sized deallocation alignment (small)\n")
+
     def test_free_sized_small(self):
         _stdout, _stderr, returncode = self.run_test("free_sized_small")
         self.assertEqual(returncode, 0)
@@ -255,6 +262,13 @@ def test_invalid_malloc_object_size_small_quarantine(self):
         self.assertEqual(stderr.decode(
             "utf-8"), "fatal allocator error: invalid malloc_object_size (quarantine)\n")
 
+    def test_invalid_malloc_object_size_small_canary(self):
+        _stdout, stderr, returncode = self.run_test(
+            "invalid_malloc_object_size_small_canary")
+        self.assertEqual(returncode, -6)
+        self.assertEqual(stderr.decode(
+            "utf-8"), "fatal allocator error: invalid malloc_object_size (canary)\n")
+
     def test_impossibly_large_malloc(self):
         _stdout, stderr, returncode = self.run_test(
             "impossibly_large_malloc")