From 6f2d3104c82f81c1f0123a3cfb25ae670841d0ba Mon Sep 17 00:00:00 2001
From: Lazar Trsic <Lazar.Trsic@imgtec.com>
Date: Tue, 13 Oct 2015 16:43:00 +0200
Subject: [PATCH] Correctly resolve realpath for absolute paths

Introduced by: https://android-review.googlesource.com/174475

Change-Id: I44e00040b28be167d5141454f919340afec6084e
---
 linker/linker.cpp    |  4 ++++
 tests/dlfcn_test.cpp | 23 +++++++++++++++++++----
 2 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/linker/linker.cpp b/linker/linker.cpp
index 841b9575f..4e899c312 100644
--- a/linker/linker.cpp
+++ b/linker/linker.cpp
@@ -1318,6 +1318,10 @@ static int open_library(ZipArchiveCache* zip_archive_cache,
     int fd = TEMP_FAILURE_RETRY(open(name, O_RDONLY | O_CLOEXEC));
     if (fd != -1) {
       *file_offset = 0;
+      if (!realpath_fd(fd, realpath)) {
+        PRINT("warning: unable to get realpath for the library \"%s\". Will use given path.", name);
+        *realpath = name;
+      }
     }
     return fd;
   }
diff --git a/tests/dlfcn_test.cpp b/tests/dlfcn_test.cpp
index 00cbdc6fd..ed972ba23 100644
--- a/tests/dlfcn_test.cpp
+++ b/tests/dlfcn_test.cpp
@@ -830,10 +830,11 @@ TEST(dlfcn, dladdr_executable) {
 }
 
 #if defined(__LP64__)
-#define BIONIC_PATH_TO_LIBC "/system/lib64/libc.so"
+#define PATH_TO_SYSTEM_LIB "/system/lib64/"
 #else
-#define BIONIC_PATH_TO_LIBC "/system/lib/libc.so"
+#define PATH_TO_SYSTEM_LIB "/system/lib/"
 #endif
+#define PATH_TO_LIBC PATH_TO_SYSTEM_LIB "libc.so"
 
 TEST(dlfcn, dladdr_libc) {
 #if defined(__BIONIC__)
@@ -843,7 +844,7 @@ TEST(dlfcn, dladdr_libc) {
 
   // /system/lib is symlink when this test is executed on host.
   char libc_realpath[PATH_MAX];
-  ASSERT_TRUE(realpath(BIONIC_PATH_TO_LIBC, libc_realpath) == libc_realpath);
+  ASSERT_TRUE(realpath(PATH_TO_LIBC, libc_realpath) == libc_realpath);
 
   ASSERT_STREQ(libc_realpath, info.dli_fname);
   // TODO: add check for dfi_fbase
@@ -1063,7 +1064,7 @@ extern "C" int version_zero_function2() {
   return 0;
 }
 
-TEST(dlfcn, dt_runpath) {
+TEST(dlfcn, dt_runpath_smoke) {
   void* handle = dlopen("libtest_dt_runpath_d.so", RTLD_NOW);
   ASSERT_TRUE(handle != nullptr) << dlerror();
 
@@ -1076,3 +1077,17 @@ TEST(dlfcn, dt_runpath) {
 
   dlclose(handle);
 }
+
+TEST(dlfcn, dt_runpath_absolute_path) {
+  void* handle = dlopen(PATH_TO_SYSTEM_LIB "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);
+}