4 files changed, 33 insertions, 3 deletions
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 40745f97..43f32aad 100644
--- a/src/malloc/mallocng/free.c
+++ b/src/malloc/mallocng/free.c
@@ -119,7 +119,11 @@ 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) madvise(base, len, MADV_FREE);
+		if (len && USE_MADV_FREE) {
+			int e = errno;
+			madvise(base, len, MADV_FREE);
+			errno = e;
+		}
 	}
 
 	// atomic free without locking if this is neither first or last slot
@@ -139,5 +143,9 @@ void free(void *p)
 	wrlock();
 	struct mapinfo mi = nontrivial_free(g, idx);
 	unlock();
-	if (mi.len) munmap(mi.base, mi.len);
+	if (mi.len) {
+		int e = errno;
+		munmap(mi.base, mi.len);
+		errno = e;
+	}
 }
diff --git a/src/malloc/mallocng/glue.h b/src/malloc/mallocng/glue.h
index 16acd1ea..77f4c812 100644
--- a/src/malloc/mallocng/glue.h
+++ b/src/malloc/mallocng/glue.h
@@ -20,6 +20,12 @@
 #define is_allzero __malloc_allzerop
 #define dump_heap __dump_heap
 
+#define malloc __libc_malloc_impl
+#define realloc __libc_realloc
+#define free __libc_free
+
+#define USE_MADV_FREE 0
+
 #if USE_REAL_ASSERT
 #include <assert.h>
 #else
@@ -56,7 +62,8 @@ __attribute__((__visibility__("hidden")))
 extern int __malloc_lock[1];
 
 #define LOCK_OBJ_DEF \
-int __malloc_lock[1];
+int __malloc_lock[1]; \
+void __malloc_atfork(int who) { malloc_atfork(who); }
 
 static inline void rdlock()
 {
@@ -73,5 +80,16 @@ static inline void unlock()
 static inline void upgradelock()
 {
 }
+static inline void resetlock()
+{
+	__malloc_lock[0] = 0;
+}
+
+static inline void malloc_atfork(int who)
+{
+	if (who<0) rdlock();
+	else if (who>0) resetlock();
+	else unlock();
+}
 
 #endif
diff --git a/src/malloc/mallocng/malloc_usable_size.c b/src/malloc/mallocng/malloc_usable_size.c
index a440a4ea..ce6a960c 100644
--- a/src/malloc/mallocng/malloc_usable_size.c
+++ b/src/malloc/mallocng/malloc_usable_size.c
@@ -3,6 +3,7 @@
 
 size_t malloc_usable_size(void *p)
 {
+	if (!p) return 0;
 	struct meta *g = get_meta(p);
 	int idx = get_slot_index(p);
 	size_t stride = get_stride(g);