From d6bf3d5e19f192dc1949b573d931d487c42730fa Mon Sep 17 00:00:00 2001
From: Dan Albert <danalbert@google.com>
Date: Wed, 1 Apr 2015 16:26:54 -0700
Subject: [PATCH] Don't export new/delete from libc shared libraries.

This used to be handled by -fvisibility=hidden on libc_cxa, but that
was broken by the resolution of https://llvm.org/PR22419 (introduced
to Android in today's clang update).

Now we just use a version script that prevents these from being
re-exported from our shared libraries.

Change-Id: Ib290e1d0d7426e09ad17a91178162fff6dbdcfa9
---
 libc/Android.mk         | 27 +++++++++++++++++++++------
 libc/version_script.txt | 12 ++++++++++++
 2 files changed, 33 insertions(+), 6 deletions(-)
 create mode 100644 libc/version_script.txt

diff --git a/libc/Android.mk b/libc/Android.mk
index e438552eb..0de0fb21c 100644
--- a/libc/Android.mk
+++ b/libc/Android.mk
@@ -1347,9 +1347,6 @@ LOCAL_CFLAGS := $(libc_common_cflags)
 LOCAL_CONLYFLAGS := $(libc_common_conlyflags)
 LOCAL_CPPFLAGS := $(libc_common_cppflags)
 
-# TODO: This is to work around b/19059885. Remove after root cause is fixed
-LOCAL_LDFLAGS_arm := -Wl,--hash-style=sysv
-
 LOCAL_C_INCLUDES := $(libc_common_c_includes)
 LOCAL_SRC_FILES := \
     $(libc_arch_dynamic_src_files) \
@@ -1359,8 +1356,10 @@ LOCAL_SRC_FILES := \
 
 LOCAL_MODULE := libc
 LOCAL_CLANG := $(use_clang)
-LOCAL_ADDITIONAL_DEPENDENCIES := $(libc_common_additional_dependencies)
 LOCAL_REQUIRED_MODULES := tzdata
+LOCAL_ADDITIONAL_DEPENDENCIES := \
+    $(libc_common_additional_dependencies) \
+    $(LOCAL_PATH)/version_script.txt \
 
 # Leave the symbols in the shared library so that stack unwinders can produce
 # meaningful name resolution.
@@ -1379,11 +1378,17 @@ LOCAL_WHOLE_STATIC_LIBRARIES := libc_common
 LOCAL_CXX_STL := none
 LOCAL_SYSTEM_SHARED_LIBRARIES :=
 
+# Don't re-export new/delete and friends, even if the compiler really wants to.
+LOCAL_LDFLAGS := -Wl,--version-script,$(LOCAL_PATH)/version_script.txt
+
 # We'd really like to do this for all architectures, but since this wasn't done
 # before, these symbols must continue to be exported on LP32 for binary
 # compatibility.
 LOCAL_LDFLAGS_64 := -Wl,--exclude-libs,libgcc.a
 
+# TODO: This is to work around b/19059885. Remove after root cause is fixed
+LOCAL_LDFLAGS_arm := -Wl,--hash-style=sysv
+
 $(eval $(call patch-up-arch-specific-flags,LOCAL_CFLAGS,libc_common_cflags))
 $(eval $(call patch-up-arch-specific-flags,LOCAL_SRC_FILES,libc_arch_dynamic_src_files))
 # special for arm
@@ -1431,7 +1436,9 @@ LOCAL_SRC_FILES := \
 
 LOCAL_MODULE := libc_malloc_debug_leak
 LOCAL_CLANG := $(use_clang)
-LOCAL_ADDITIONAL_DEPENDENCIES := $(libc_common_additional_dependencies)
+LOCAL_ADDITIONAL_DEPENDENCIES := \
+    $(libc_common_additional_dependencies) \
+    $(LOCAL_PATH)/version_script.txt \
 
 LOCAL_SHARED_LIBRARIES := libc libdl
 LOCAL_CXX_STL := none
@@ -1442,6 +1449,9 @@ LOCAL_STATIC_LIBRARIES_arm := libunwind_llvm
 LOCAL_STATIC_LIBRARIES += libc++abi
 LOCAL_ALLOW_UNDEFINED_SYMBOLS := true
 
+# Don't re-export new/delete and friends, even if the compiler really wants to.
+LOCAL_LDFLAGS := -Wl,--version-script,$(LOCAL_PATH)/version_script.txt
+
 # Don't install on release build
 LOCAL_MODULE_TAGS := eng debug
 LOCAL_ADDRESS_SANITIZER := false
@@ -1471,12 +1481,17 @@ LOCAL_SRC_FILES := \
 
 LOCAL_MODULE := libc_malloc_debug_qemu
 LOCAL_CLANG := $(use_clang)
-LOCAL_ADDITIONAL_DEPENDENCIES := $(libc_common_additional_dependencies)
+LOCAL_ADDITIONAL_DEPENDENCIES := \
+    $(libc_common_additional_dependencies) \
+    $(LOCAL_PATH)/version_script.txt \
 
 LOCAL_SHARED_LIBRARIES := libc libdl
 LOCAL_CXX_STL := none
 LOCAL_SYSTEM_SHARED_LIBRARIES :=
 
+# Don't re-export new/delete and friends, even if the compiler really wants to.
+LOCAL_LDFLAGS := -Wl,--version-script,$(LOCAL_PATH)/version_script.txt
+
 # Don't install on release build
 LOCAL_MODULE_TAGS := eng debug
 LOCAL_ADDRESS_SANITIZER := false
diff --git a/libc/version_script.txt b/libc/version_script.txt
new file mode 100644
index 000000000..afc5e5c47
--- /dev/null
+++ b/libc/version_script.txt
@@ -0,0 +1,12 @@
+LIBC {
+  local:
+    _ZSt7nothrow;
+    _ZdaPv;
+    _ZdaPvRKSt9nothrow_t;
+    _ZdlPv;
+    _ZdlPvRKSt9nothrow_t;
+    _Znaj;
+    _ZnajRKSt9nothrow_t;
+    _Znwj;
+    _ZnwjRKSt9nothrow_t;
+};