Support DT_RUNPATH in the linker.
Only $ORIGIN substitution is supported, but not linux-specific $LIB
or $PLATFORM.
Change-Id: I5814a016c7c91afba080230a547a863686e7c2b9
diff --git a/linker/linker.cpp b/linker/linker.cpp
index 115de5c..6232ddc 100644
--- a/linker/linker.cpp
+++ b/linker/linker.cpp
@@ -97,6 +97,14 @@
__LIBC_HIDDEN__ abort_msg_t* g_abort_message = nullptr; // For debuggerd.
+static std::string dirname(const char *path) {
+ const char* last_slash = strrchr(path, '/');
+ if (last_slash == path) return "/";
+ else if (last_slash == nullptr) return ".";
+ else
+ return std::string(path, last_slash - path);
+}
+
#if STATS
struct linker_stats_t {
int count[kRelocMax];
@@ -308,6 +316,38 @@
parse_path(path, ":", &g_ld_library_paths);
}
+void soinfo::set_dt_runpath(const char* path) {
+ if (!has_min_version(2)) return;
+ parse_path(path, ":", &dt_runpath_);
+
+ std::string origin = dirname(get_realpath());
+ // FIXME: add $LIB and $PLATFORM.
+ std::pair<std::string, std::string> substs[] = {{"ORIGIN", origin}};
+ for (std::string& s : dt_runpath_) {
+ size_t pos = 0;
+ while (pos < s.size()) {
+ pos = s.find("$", pos);
+ if (pos == std::string::npos) break;
+ for (const auto& subst : substs) {
+ const std::string& token = subst.first;
+ const std::string& replacement = subst.second;
+ if (s.substr(pos + 1, token.size()) == token) {
+ s.replace(pos, token.size() + 1, replacement);
+ // -1 to compensate for the ++pos below.
+ pos += replacement.size() - 1;
+ break;
+ } else if (s.substr(pos + 1, token.size() + 2) == "{" + token + "}") {
+ s.replace(pos, token.size() + 3, replacement);
+ pos += replacement.size() - 1;
+ break;
+ }
+ }
+ // Skip $ in case it did not match any of the known substitutions.
+ ++pos;
+ }
+ }
+}
+
static void parse_LD_PRELOAD(const char* path) {
// We have historically supported ':' as well as ' ' in LD_PRELOAD.
parse_path(path, " :", &g_ld_preload_names);
@@ -1161,8 +1201,9 @@
return -1;
}
-static int open_library_on_ld_library_path(const char* name, off64_t* file_offset) {
- for (const auto& path_str : g_ld_library_paths) {
+static int open_library_on_paths(const char* name, off64_t* file_offset,
+ const std::vector<std::string>& paths) {
+ for (const auto& path_str : paths) {
char buf[512];
const char* const path = path_str.c_str();
if (!format_path(buf, sizeof(buf), path, name)) {
@@ -1189,7 +1230,7 @@
return -1;
}
-static int open_library(const char* name, off64_t* file_offset) {
+static int open_library(const char* name, soinfo *needed_by, off64_t* file_offset) {
TRACE("[ opening %s ]", name);
// If the name contains a slash, we should attempt to open it directly and not search the paths.
@@ -1209,7 +1250,10 @@
}
// Otherwise we try LD_LIBRARY_PATH first, and fall back to the built-in well known paths.
- int fd = open_library_on_ld_library_path(name, file_offset);
+ int fd = open_library_on_paths(name, file_offset, g_ld_library_paths);
+ if (fd == -1 && needed_by) {
+ fd = open_library_on_paths(name, file_offset, needed_by->get_dt_runpath());
+ }
if (fd == -1) {
fd = open_library_on_default_path(name, file_offset);
}
@@ -1319,8 +1363,8 @@
return si;
}
-static soinfo* load_library(LoadTaskList& load_tasks,
- const char* name, int rtld_flags,
+static soinfo* load_library(LoadTaskList& load_tasks, const char* name,
+ soinfo* needed_by, int rtld_flags,
const android_dlextinfo* extinfo) {
if (extinfo != nullptr && (extinfo->flags & ANDROID_DLEXT_USE_LIBRARY_FD) != 0) {
off64_t file_offset = 0;
@@ -1332,7 +1376,7 @@
// Open the file.
off64_t file_offset;
- int fd = open_library(name, &file_offset);
+ int fd = open_library(name, needed_by, &file_offset);
if (fd == -1) {
DL_ERR("library \"%s\" not found", name);
return nullptr;
@@ -1358,14 +1402,15 @@
}
static soinfo* find_library_internal(LoadTaskList& load_tasks, const char* name,
- int rtld_flags, const android_dlextinfo* extinfo) {
+ soinfo* needed_by, int rtld_flags,
+ const android_dlextinfo* extinfo) {
soinfo* si = find_loaded_library_by_soname(name);
// Library might still be loaded, the accurate detection
// of this fact is done by load_library.
if (si == nullptr) {
TRACE("[ '%s' has not been found by soname. Trying harder...]", name);
- si = load_library(load_tasks, name, rtld_flags, extinfo);
+ si = load_library(load_tasks, name, needed_by, rtld_flags, extinfo);
}
return si;
@@ -1434,13 +1479,13 @@
// Step 1: load and pre-link all DT_NEEDED libraries in breadth first order.
for (LoadTask::unique_ptr task(load_tasks.pop_front());
task.get() != nullptr; task.reset(load_tasks.pop_front())) {
- soinfo* si = find_library_internal(load_tasks, task->get_name(), rtld_flags, extinfo);
+ soinfo* needed_by = task->get_needed_by();
+ soinfo* si = find_library_internal(load_tasks, task->get_name(), needed_by,
+ rtld_flags, extinfo);
if (si == nullptr) {
return false;
}
- soinfo* needed_by = task->get_needed_by();
-
if (needed_by != nullptr) {
needed_by->add_child(si);
}
@@ -2337,6 +2382,16 @@
return g_empty_list;
}
+static std::vector<std::string> g_empty_runpath;
+
+const std::vector<std::string>& soinfo::get_dt_runpath() const {
+ if (has_min_version(2)) {
+ return dt_runpath_;
+ }
+
+ return g_empty_runpath;
+}
+
ElfW(Addr) soinfo::resolve_symbol_address(const ElfW(Sym)* s) const {
if (ELF_ST_TYPE(s->st_info) == STT_GNU_IFUNC) {
return call_ifunc_resolver(s->st_value + load_bias);
@@ -2833,6 +2888,10 @@
verneed_cnt_ = d->d_un.d_val;
break;
+ case DT_RUNPATH:
+ // this is parsed after we have strtab initialized (see below).
+ break;
+
default:
if (!relocating_linker) {
DL_WARN("%s: unused DT entry: type %p arg %p", get_realpath(),
@@ -2866,12 +2925,17 @@
// second pass - parse entries relying on strtab
for (ElfW(Dyn)* d = dynamic; d->d_tag != DT_NULL; ++d) {
- if (d->d_tag == DT_SONAME) {
- soname_ = get_string(d->d_un.d_val);
+ switch (d->d_tag) {
+ case DT_SONAME:
+ soname_ = get_string(d->d_un.d_val);
#if defined(__work_around_b_19059885__)
- strlcpy(old_name_, soname_, sizeof(old_name_));
+ strlcpy(old_name_, soname_, sizeof(old_name_));
#endif
- break;
+ break;
+ case DT_RUNPATH:
+ // FIXME: $LIB, $PLATFORM unsupported.
+ set_dt_runpath(get_string(d->d_un.d_val));
+ break;
}
}
diff --git a/linker/linker.h b/linker/linker.h
index 6042cb8..b64f42c 100644
--- a/linker/linker.h
+++ b/linker/linker.h
@@ -336,6 +336,8 @@
uint32_t get_target_sdk_version() const;
+ const std::vector<std::string>& get_dt_runpath() const;
+
private:
bool elf_lookup(SymbolName& symbol_name, const version_info* vi, uint32_t* symbol_index) const;
ElfW(Sym)* elf_addr_lookup(const void* addr);
@@ -397,6 +399,9 @@
uint32_t target_sdk_version_;
+ void set_dt_runpath(const char *);
+ std::vector<std::string> dt_runpath_;
+
friend soinfo* get_libdl_info();
};
diff --git a/tests/Android.build.mk b/tests/Android.build.mk
index 5b2b417..6d4faa9 100644
--- a/tests/Android.build.mk
+++ b/tests/Android.build.mk
@@ -48,6 +48,10 @@
LOCAL_MULTILIB := $($(module)_multilib)
endif
+ifneq ($($(module)_relative_path),)
+ LOCAL_MODULE_RELATIVE_PATH := $($(module)_relative_path)
+endif
+
LOCAL_CFLAGS := \
$(common_cflags) \
$($(module)_cflags) \
diff --git a/tests/dlfcn_test.cpp b/tests/dlfcn_test.cpp
index 3c9b8e3..1c01c62 100644
--- a/tests/dlfcn_test.cpp
+++ b/tests/dlfcn_test.cpp
@@ -1062,3 +1062,17 @@
extern "C" int version_zero_function2() {
return 0;
}
+
+TEST(dlfcn, dt_runpath) {
+ void* handle = dlopen("libtest_dt_runpath_d.so", RTLD_NOW);
+ ASSERT_TRUE(handle != nullptr) << dlerror();
+
+ typedef void *(* dlopen_b_fn)();
+ dlopen_b_fn fn = (dlopen_b_fn)dlsym(handle, "dlopen_b");
+ ASSERT_TRUE(fn != nullptr) << dlerror();
+
+ void *p = fn();
+ ASSERT_TRUE(p == nullptr);
+
+ dlclose(handle);
+}
diff --git a/tests/libs/Android.build.dt_runpath.mk b/tests/libs/Android.build.dt_runpath.mk
new file mode 100644
index 0000000..e9b5265
--- /dev/null
+++ b/tests/libs/Android.build.dt_runpath.mk
@@ -0,0 +1,66 @@
+#
+# Copyright (C) 2012 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+# -----------------------------------------------------------------------------
+# Libraries used by dt_runpath tests.
+# -----------------------------------------------------------------------------
+
+# A leaf library in a non-standard directory.
+libtest_dt_runpath_a_src_files := \
+ empty.cpp
+
+libtest_dt_runpath_a_relative_path := dt_runpath_a
+module := libtest_dt_runpath_a
+include $(LOCAL_PATH)/Android.build.testlib.mk
+
+# Depends on library A with a DT_RUNPATH
+libtest_dt_runpath_b_src_files := \
+ empty.cpp
+
+libtest_dt_runpath_b_shared_libraries := libtest_dt_runpath_a
+libtest_dt_runpath_b_ldflags := -Wl,--rpath,\$${ORIGIN}/../dt_runpath_a
+libtest_dt_runpath_b_relative_path := dt_runpath_b_c_x
+module := libtest_dt_runpath_b
+include $(LOCAL_PATH)/Android.build.testlib.mk
+
+# Depends on library A with an incorrect DT_RUNPATH. This does not matter
+# because B is the first in the D (below) dependency order, and library A
+# is already loaded using the correct DT_RUNPATH from library B.
+libtest_dt_runpath_c_src_files := \
+ empty.cpp
+
+libtest_dt_runpath_c_shared_libraries := libtest_dt_runpath_a
+libtest_dt_runpath_c_ldflags := -Wl,--rpath,\$${ORIGIN}/invalid_dt_runpath
+libtest_dt_runpath_c_relative_path := dt_runpath_b_c_x
+module := libtest_dt_runpath_c
+include $(LOCAL_PATH)/Android.build.testlib.mk
+
+# D depends on B and C with DT_RUNPATH.
+libtest_dt_runpath_d_src_files := \
+ dlopen_b.cpp
+
+libtest_dt_runpath_d_shared_libraries := libtest_dt_runpath_b libtest_dt_runpath_c
+libtest_dt_runpath_d_ldflags := -Wl,--rpath,\$${ORIGIN}/dt_runpath_b_c_x
+module := libtest_dt_runpath_d
+include $(LOCAL_PATH)/Android.build.testlib.mk
+
+# A leaf library in a directory library D has DT_RUNPATH for.
+libtest_dt_runpath_x_src_files := \
+ empty.cpp
+
+libtest_dt_runpath_x_relative_path := dt_runpath_b_c_x
+module := libtest_dt_runpath_x
+include $(LOCAL_PATH)/Android.build.testlib.mk
diff --git a/tests/libs/Android.mk b/tests/libs/Android.mk
index a5ef622..662aeef 100644
--- a/tests/libs/Android.mk
+++ b/tests/libs/Android.mk
@@ -20,6 +20,7 @@
common_cppflags += -std=gnu++11
common_additional_dependencies := \
$(LOCAL_PATH)/Android.mk \
+ $(LOCAL_PATH)/Android.build.dt_runpath.mk \
$(LOCAL_PATH)/Android.build.dlext_testzip.mk \
$(LOCAL_PATH)/Android.build.dlopen_2_parents_reloc.mk \
$(LOCAL_PATH)/Android.build.dlopen_check_order_dlsym.mk \
@@ -180,6 +181,11 @@
include $(LOCAL_PATH)/Android.build.testlib.mk
# -----------------------------------------------------------------------------
+# Build DT_RUNPATH test helper libraries
+# -----------------------------------------------------------------------------
+include $(LOCAL_PATH)/Android.build.dt_runpath.mk
+
+# -----------------------------------------------------------------------------
# Build library with two parents
# -----------------------------------------------------------------------------
include $(LOCAL_PATH)/Android.build.dlopen_2_parents_reloc.mk
diff --git a/tests/libs/dlopen_b.cpp b/tests/libs/dlopen_b.cpp
new file mode 100644
index 0000000..34f2881
--- /dev/null
+++ b/tests/libs/dlopen_b.cpp
@@ -0,0 +1,7 @@
+#include <dlfcn.h>
+extern "C" void *dlopen_b() {
+ // This is not supposed to succeed. Even though this library has DT_RUNPATH
+ // for libtest_dt_runpath_x.so, it is not taked into account for dlopen.
+ void *handle = dlopen("libtest_dt_runpath_x.so", RTLD_NOW);
+ return handle;
+}
