5 files changed, 13 insertions, 5 deletions
diff --git a/src/malloc/free.c b/src/malloc/free.c
index f17a952c..3944f7b2 100644
--- a/src/malloc/free.c
+++ b/src/malloc/free.c
@@ -2,5 +2,5 @@
 
 void free(void *p)
 {
-	return __libc_free(p);
+	__libc_free(p);
 }
diff --git a/src/malloc/mallocng/aligned_alloc.c b/src/malloc/mallocng/aligned_alloc.c
index 34116896..e0862a83 100644
--- a/src/malloc/mallocng/aligned_alloc.c
+++ b/src/malloc/mallocng/aligned_alloc.c
@@ -22,6 +22,9 @@ void *aligned_alloc(size_t align, size_t len)
 	if (align <= UNIT) align = UNIT;
 
 	unsigned char *p = malloc(len + align - UNIT);
+	if (!p)
+		return 0;
+
 	struct meta *g = get_meta(p);
 	int idx = get_slot_index(p);
 	size_t stride = get_stride(g);
diff --git a/src/malloc/mallocng/free.c b/src/malloc/mallocng/free.c
index 418a085c..43f32aad 100644
--- a/src/malloc/mallocng/free.c
+++ b/src/malloc/mallocng/free.c
@@ -119,7 +119,7 @@ void free(void *p)
 	if (((uintptr_t)(start-1) ^ (uintptr_t)end) >= 2*PGSZ && g->last_idx) {
 		unsigned char *base = start + (-(uintptr_t)start & (PGSZ-1));
 		size_t len = (end-base) & -PGSZ;
-		if (len) {
+		if (len && USE_MADV_FREE) {
 			int e = errno;
 			madvise(base, len, MADV_FREE);
 			errno = e;
diff --git a/src/malloc/mallocng/glue.h b/src/malloc/mallocng/glue.h
index 151c48b8..c347a4ef 100644
--- a/src/malloc/mallocng/glue.h
+++ b/src/malloc/mallocng/glue.h
@@ -24,6 +24,8 @@
 #define realloc __libc_realloc
 #define free __libc_free
 
+#define USE_MADV_FREE 0
+
 #if USE_REAL_ASSERT
 #include <assert.h>
 #else
@@ -34,8 +36,10 @@
 #define brk(p) ((uintptr_t)__syscall(SYS_brk, p))
 
 #define mmap __mmap
+#define munmap __munmap
 #define madvise __madvise
 #define mremap __mremap
+#define mprotect __mprotect
 
 #define DISABLE_ALIGNED_ALLOC (__malloc_replaced && !__aligned_alloc_replaced)
 
@@ -60,8 +64,8 @@ __attribute__((__visibility__("hidden")))
 extern int __malloc_lock[1];
 
 #define LOCK_OBJ_DEF \
-int __malloc_lock[1]; \
-void __malloc_atfork(int who) { malloc_atfork(who); }
+void __malloc_atfork(int who) { malloc_atfork(who); } \
+int __malloc_lock[1]
 
 static inline void rdlock()
 {
diff --git a/src/malloc/mallocng/meta.h b/src/malloc/mallocng/meta.h
index 61ec53f9..3a27af64 100644
--- a/src/malloc/mallocng/meta.h
+++ b/src/malloc/mallocng/meta.h
@@ -129,12 +129,13 @@ static inline int get_slot_index(const unsigned char *p)
 static inline struct meta *get_meta(const unsigned char *p)
 {
 	assert(!((uintptr_t)p & 15));
-	int offset = *(const uint16_t *)(p - 2);
+	size_t offset = *(const uint16_t *)(p - 2);
 	int index = get_slot_index(p);
 	if (p[-4]) {
 		assert(!offset);
 		offset = *(uint32_t *)(p - 8);
 		assert(offset > 0xffff);
+		assert(offset < PTRDIFF_MAX/UNIT);
 	}
 	const struct group *base = (const void *)(p - UNIT*offset - UNIT);
 	const struct meta *meta = base->meta;