Merge "Add tests for /proc/self/fd and /proc/self/task/TID/fd access"

tests/Android.mk

@@ -51,6 +51,7 @@ test_cppflags := \
 libBionicStandardTests_src_files := \
     arpa_inet_test.cpp \
     buffer_tests.cpp \
+    bug_26110743_test.cpp \
     complex_test.cpp \
     ctype_test.cpp \
     dirent_test.cpp \

tests/bug_26110743_test.cpp

@@ -0,0 +1,113 @@
+/*
+ * Copyright (C) 2015 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.
+ */
+
+#include <gtest/gtest.h>
+#include <pthread.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/prctl.h>
+
+#include "private/ScopeGuard.h"
+
+extern "C" pid_t gettid();
+
+static void ProcSelfReadlinkBody() {
+  char buf[100];
+  char buf2[1024];
+  int fd = open("/dev/null", O_RDWR | O_CLOEXEC);
+  ASSERT_NE(-1, fd);
+  snprintf(buf, sizeof(buf), "/proc/self/fd/%d", fd);
+  const char* ERRORMSG = "Please apply the following two kernel patches:\n"
+    "* https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=73af963f9f3036dffed55c3a2898598186db1045\n"
+    "* https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=96d0df79f2644fc823f26c06491e182d87a90c2a\n";
+  ASSERT_NE(-1, readlink(buf, buf2, sizeof(buf2))) << ERRORMSG;
+  ASSERT_STREQ("/dev/null", buf2);
+  close(fd);
+}
+
+static void* ProcSelfReadlink(void*) {
+  ProcSelfReadlinkBody();
+  return NULL;
+}
+
+TEST(bug_26110743, ProcSelfReadlink) {
+  pthread_t t;
+  ASSERT_EQ(0, pthread_create(&t, NULL, ProcSelfReadlink, NULL));
+  void* result;
+  ASSERT_EQ(0, pthread_join(t, &result));
+  ASSERT_EQ(NULL, result);
+}
+
+TEST(bug_26110743, ProcSelfReadlink_NotDumpable) {
+  int dumpable = prctl(PR_GET_DUMPABLE, 0, 0, 0, 0);
+  prctl(PR_SET_DUMPABLE, 0, 0, 0, 0);
+  auto guard = make_scope_guard([&]() {
+    // restore dumpable
+    prctl(PR_SET_DUMPABLE, dumpable, 0, 0, 0);
+  });
+
+  pthread_t t;
+  ASSERT_EQ(0, pthread_create(&t, NULL, ProcSelfReadlink, NULL));
+  void* result;
+  ASSERT_EQ(0, pthread_join(t, &result));
+  ASSERT_EQ(NULL, result);
+}
+
+static void ProcTaskFdReadlinkBody() {
+  char buf[200];
+  char buf2[1024];
+  int fd = open("/dev/null", O_RDWR | O_CLOEXEC);
+  ASSERT_NE(-1, fd);
+  pid_t mypid = getpid();
+  pid_t mytid = gettid();
+  ASSERT_NE(mypid, mytid);
+  snprintf(buf, sizeof(buf), "/proc/%d/task/%d/fd/%d", mypid, mytid, fd);
+  const char* ERRORMSG = "Please apply the following kernel patch:\n"
+    "* https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=54708d2858e79a2bdda10bf8a20c80eb96c20613\n";
+  ASSERT_NE(-1, readlink(buf, buf2, sizeof(buf2))) << ERRORMSG;
+  ASSERT_STREQ("/dev/null", buf2);
+  close(fd);
+}
+
+static void* ProcTaskFdReadlink(void*) {
+  ProcTaskFdReadlinkBody();
+  return NULL;
+}
+
+TEST(bug_26110743, ProcTaskFdReadlink) {
+  pthread_t t;
+  ASSERT_EQ(0, pthread_create(&t, NULL, ProcTaskFdReadlink, NULL));
+  void* result;
+  ASSERT_EQ(0, pthread_join(t, &result));
+  ASSERT_EQ(NULL, result);
+}
+
+TEST(bug_26110743, ProcTaskFdReadlink_NotDumpable) {
+  int dumpable = prctl(PR_GET_DUMPABLE, 0, 0, 0, 0);
+  prctl(PR_SET_DUMPABLE, 0, 0, 0, 0);
+  auto guard = make_scope_guard([&]() {
+    // restore dumpable
+    prctl(PR_SET_DUMPABLE, dumpable, 0, 0, 0);
+  });
+
+  pthread_t t;
+  ASSERT_EQ(0, pthread_create(&t, NULL, ProcTaskFdReadlink, NULL));
+  void* result;
+  ASSERT_EQ(0, pthread_join(t, &result));
+  ASSERT_EQ(NULL, result);
+}