upload android base code part3

android/bionic/tests/sys_prctl_test.cpp

@@ -0,0 +1,114 @@
+/*
+ * 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 <inttypes.h>
+#include <limits.h>
+#include <stdio.h>
+#include <sys/capability.h>
+#include <sys/mman.h>
+#include <sys/prctl.h>
+#include <unistd.h>
+
+#include <string>
+#include <vector>
+
+#include <gtest/gtest.h>
+
+#include "android-base/file.h"
+#include "android-base/strings.h"
+#include "private/bionic_prctl.h"
+
+// http://b/20017123.
+TEST(sys_prctl, bug_20017123) {
+#if defined(__ANDROID__) // PR_SET_VMA is only available in Android kernels.
+  size_t page_size = static_cast<size_t>(sysconf(_SC_PAGESIZE));
+  void* p = mmap(NULL, page_size * 3, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+  ASSERT_NE(MAP_FAILED, p);
+  ASSERT_EQ(0, mprotect(p, page_size, PROT_NONE));
+  ASSERT_NE(-1, prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, p, page_size * 3, "anonymous map space"));
+  // Now read the maps and verify that there are no overlapped maps.
+  std::string file_data;
+  ASSERT_TRUE(android::base::ReadFileToString("/proc/self/maps", &file_data));
+
+  uintptr_t last_end = 0;
+  std::vector<std::string> lines = android::base::Split(file_data, "\n");
+  for (size_t i = 0; i < lines.size(); i++) {
+    if (lines[i].empty()) {
+      continue;
+    }
+    uintptr_t start;
+    uintptr_t end;
+    ASSERT_EQ(2, sscanf(lines[i].c_str(), "%" SCNxPTR "-%" SCNxPTR " ", &start, &end))
+        << "Failed to parse line: " << lines[i];
+    // This will never fail on the first line, so no need to do any special checking.
+    ASSERT_GE(start, last_end)
+        << "Overlapping map detected:\n" << lines[i -1] << '\n' << lines[i] << '\n';
+    last_end = end;
+  }
+
+  ASSERT_EQ(0, munmap(p, page_size * 3));
+#else
+  GTEST_LOG_(INFO) << "This test does nothing as it tests an Android specific kernel feature.";
+#endif
+}
+
+TEST(sys_prctl, pr_cap_ambient) {
+// PR_CAP_AMBIENT was introduced in v4.3.  Android devices should always
+// have a backport, but we can't guarantee it's available on the host.
+#if defined(__ANDROID__) || defined(PR_CAP_AMBIENT)
+  const std::string caps_sha =
+      "https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/"
+      "?id=58319057b7847667f0c9585b9de0e8932b0fdb08";
+  const std::string caps_typo_sha =
+      "https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/"
+      "?id=b7f76ea2ef6739ee484a165ffbac98deb855d3d3";
+
+  auto err = prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_CLEAR_ALL, 0, 0, 0);
+  EXPECT_EQ(0, err);
+  // EINVAL -> unrecognized prctl option
+  ASSERT_NE(EINVAL, errno) << "kernel missing required commits:\n"
+                           << caps_sha << "\n"
+                           << caps_typo_sha << "\n";
+
+  // Unprivileged processes shouldn't be able to raise CAP_SYS_ADMIN,
+  // but they can check or lower it
+  err = prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_RAISE, CAP_SYS_ADMIN, 0, 0);
+  EXPECT_EQ(-1, err);
+  EXPECT_EQ(EPERM, errno);
+
+  err = prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_IS_SET, CAP_SYS_ADMIN, 0, 0);
+  EXPECT_EQ(0, err);
+
+  err = prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_LOWER, CAP_SYS_ADMIN, 0, 0);
+  EXPECT_EQ(0, err);
+
+  // ULONG_MAX isn't a legal cap
+  err = prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_RAISE, ULONG_MAX, 0, 0);
+  EXPECT_EQ(-1, err);
+  EXPECT_EQ(EINVAL, errno);
+
+  err = prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_IS_SET, ULONG_MAX, 0, 0);
+  EXPECT_EQ(-1, err);
+  EXPECT_EQ(EINVAL, errno);
+
+  err = prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_LOWER, ULONG_MAX, 0, 0);
+  EXPECT_EQ(-1, err);
+  EXPECT_EQ(EINVAL, errno);
+#else
+  GTEST_LOG_(INFO)
+      << "Skipping test that requires host support for PR_CAP_AMBIENT.";
+#endif
+}