Hide dlmalloc symbols.

We need to leave dlmalloc_trim and dlmalloc_inspect_all exposed for
the VM, but if we're seriously looking at other malloc implementations,
that's something we're going to have to fix.

Bug: 11156955
Change-Id: If85156c280044f1616c09a3c50ba674aaf0e8d3a

3 files changed, 36 insertions, 16 deletions

diff --git a/libc/Android.mk b/libc/Android.mk
index c0e1d32..526551e 100644
--- a/libc/Android.mk
+++ b/libc/Android.mk
@@ -500,11 +500,9 @@ endif
 
 ifeq ($(MALLOC_IMPL),jemalloc)
   libc_common_cflags += -DUSE_JEMALLOC
-
   libc_malloc_src := bionic/jemalloc.cpp
 else
   libc_common_cflags += -DUSE_DLMALLOC
-
   libc_malloc_src := bionic/dlmalloc.c
 endif
 
@@ -821,6 +819,7 @@ LOCAL_WHOLE_STATIC_LIBRARIES := \
     libc_dns \
     libc_freebsd \
     libc_gdtoa \
+    libc_malloc \
     libc_netbsd \
     libc_openbsd \
     libc_stack_protector \
@@ -828,8 +827,7 @@ LOCAL_WHOLE_STATIC_LIBRARIES := \
     libc_tzcode \
 
 ifeq ($(MALLOC_IMPL),jemalloc)
-LOCAL_WHOLE_STATIC_LIBRARIES += \
-    libjemalloc
+LOCAL_WHOLE_STATIC_LIBRARIES += libjemalloc
 endif
 
 LOCAL_SYSTEM_SHARED_LIBRARIES :=
@@ -879,6 +877,24 @@ include $(BUILD_STATIC_LIBRARY)
 
 
 # ========================================================
+# libc_malloc.a: the _prefixed_ malloc functions (like dlcalloc).
+# ========================================================
+
+include $(CLEAR_VARS)
+LOCAL_SRC_FILES := $(libc_malloc_src)
+LOCAL_CFLAGS := $(libc_common_cflags) \
+    -Werror \
+    -fvisibility=hidden \
+
+LOCAL_CONLYFLAGS := $(libc_common_conlyflags)
+LOCAL_CPPFLAGS := $(libc_common_cppflags)
+LOCAL_C_INCLUDES := $(libc_common_c_includes)
+LOCAL_MODULE := libc_malloc
+LOCAL_ADDITIONAL_DEPENDENCIES := $(libc_common_additional_dependencies)
+include $(BUILD_STATIC_LIBRARY)
+
+
+# ========================================================
 # libc.a
 # ========================================================
 include $(CLEAR_VARS)
@@ -886,7 +902,6 @@ include $(CLEAR_VARS)
 LOCAL_SRC_FILES := \
     $(libc_arch_static_src_files) \
     $(libc_static_common_src_files) \
-    $(libc_malloc_src) \
     bionic/malloc_debug_common.cpp \
     bionic/libc_init_static.cpp \
 
@@ -919,7 +934,6 @@ LOCAL_C_INCLUDES := $(libc_common_c_includes)
 LOCAL_SRC_FILES := \
     $(libc_arch_dynamic_src_files) \
     $(libc_static_common_src_files) \
-    $(libc_malloc_src) \
     bionic/malloc_debug_common.cpp \
     bionic/debug_mapinfo.cpp \
     bionic/debug_stacktrace.cpp \
diff --git a/libc/bionic/dlmalloc.c b/libc/bionic/dlmalloc.c
index 3a615d2..2d67392 100644
--- a/libc/bionic/dlmalloc.c
+++ b/libc/bionic/dlmalloc.c
@@ -46,14 +46,11 @@ static void __bionic_heap_usage_error(const char* function, void* address) {
   *((int**) 0xdeadbaad) = (int*) address;
 }
 
-static void* named_anonymous_mmap(size_t length)
-{
-    void* ret;
-    ret = mmap(NULL, length, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
-    if (ret == MAP_FAILED)
-        return ret;
-
-    __bionic_name_mem(ret, length, "libc_malloc");
-
-    return ret;
+static void* named_anonymous_mmap(size_t length) {
+  void* map = mmap(NULL, length, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
+  if (map == MAP_FAILED) {
+    return map;
+  }
+  __bionic_name_mem(map, length, "libc_malloc");
+  return map;
 }
diff --git a/libc/bionic/dlmalloc.h b/libc/bionic/dlmalloc.h
index 71b3be8..e065687 100644
--- a/libc/bionic/dlmalloc.h
+++ b/libc/bionic/dlmalloc.h
@@ -17,6 +17,9 @@
 #ifndef LIBC_BIONIC_DLMALLOC_H_
 #define LIBC_BIONIC_DLMALLOC_H_
 
+#include <sys/cdefs.h>
+#include <stddef.h>
+
 /* Configure dlmalloc. */
 #define HAVE_GETPAGESIZE 1
 #define MALLOC_INSPECT_ALL 1
@@ -29,6 +32,12 @@
 #define USE_SPIN_LOCKS 0
 #define DEFAULT_MMAP_THRESHOLD (64U * 1024U)
 
+/* Export two symbols used by the VM. */
+__BEGIN_DECLS
+int dlmalloc_trim(size_t) __LIBC_ABI_PUBLIC__;
+void dlmalloc_inspect_all(void (*handler)(void*, void*, size_t, void*), void*) __LIBC_ABI_PUBLIC__;
+__END_DECLS
+
 /* Include the proper definitions. */
 #include "../upstream-dlmalloc/malloc.h"