1 files changed, 98 insertions, 0 deletions
diff --git a/test/util/proc_util.cc b/test/util/proc_util.cc
new file mode 100644
index 000000000..72f7e67d0
--- /dev/null
+++ b/test/util/proc_util.cc
@@ -0,0 +1,98 @@
+// Copyright 2018 Google LLC
+//
+// 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 "test/util/proc_util.h"
+
+#include <algorithm>
+#include <vector>
+
+#include "absl/strings/str_cat.h"
+#include "absl/strings/str_split.h"
+#include "absl/strings/string_view.h"
+#include "test/util/fs_util.h"
+#include "test/util/test_util.h"
+
+namespace gvisor {
+namespace testing {
+
+// Parses a single line from /proc/<xxx>/maps.
+PosixErrorOr<ProcMapsEntry> ParseProcMapsLine(absl::string_view line) {
+  ProcMapsEntry map_entry = {};
+  std::vector<std::string> parts = absl::StrSplit(line, ' ', absl::SkipEmpty());
+
+  // A size of 5 means there is no file name specified.
+  if (parts.size() != 5 && parts.size() != 6) {
+    return PosixError(EINVAL, absl::StrCat("Invalid line: ", line));
+  }
+
+  // Address range in the form X-X where X are hex values without leading 0x.
+  std::vector<std::string> addresses = absl::StrSplit(parts[0], '-');
+  if (addresses.size() != 2) {
+    return PosixError(EINVAL,
+                      absl::StrCat("Invalid address range: ", parts[0]));
+  }
+  ASSIGN_OR_RETURN_ERRNO(map_entry.start, AtoiBase(addresses[0], 16));
+  ASSIGN_OR_RETURN_ERRNO(map_entry.end, AtoiBase(addresses[1], 16));
+
+  // Permissions are four bytes of the form rwxp or - if permission not set.
+  if (parts[1].size() != 4) {
+    return PosixError(EINVAL,
+                      absl::StrCat("Invalid permission field: ", parts[1]));
+  }
+
+  map_entry.readable = parts[1][0] == 'r';
+  map_entry.writable = parts[1][1] == 'w';
+  map_entry.executable = parts[1][2] == 'x';
+  map_entry.priv = parts[1][3] == 'p';
+
+  ASSIGN_OR_RETURN_ERRNO(map_entry.offset, AtoiBase(parts[2], 16));
+
+  std::vector<std::string> device = absl::StrSplit(parts[3], ':');
+  if (device.size() != 2) {
+    return PosixError(EINVAL, absl::StrCat("Invalid device: ", parts[3]));
+  }
+  ASSIGN_OR_RETURN_ERRNO(map_entry.major, AtoiBase(device[0], 16));
+  ASSIGN_OR_RETURN_ERRNO(map_entry.minor, AtoiBase(device[1], 16));
+
+  ASSIGN_OR_RETURN_ERRNO(map_entry.inode, Atoi<int64_t>(parts[4]));
+  if (parts.size() == 6) {
+    // A filename is present.
+    map_entry.filename = parts[5];
+  }
+
+  return map_entry;
+}
+
+PosixErrorOr<std::vector<ProcMapsEntry>> ParseProcMaps(
+    absl::string_view contents) {
+  std::vector<ProcMapsEntry> entries;
+  auto lines = absl::StrSplit(contents, '\n', absl::SkipEmpty());
+  for (const auto& l : lines) {
+    LOG(INFO) << "line: " << l;
+    ASSIGN_OR_RETURN_ERRNO(auto entry, ParseProcMapsLine(l));
+    entries.push_back(entry);
+  }
+  return entries;
+}
+
+PosixErrorOr<bool> IsVsyscallEnabled() {
+  ASSIGN_OR_RETURN_ERRNO(auto contents, GetContents("/proc/self/maps"));
+  ASSIGN_OR_RETURN_ERRNO(auto maps, ParseProcMaps(contents));
+  return std::any_of(maps.begin(), maps.end(), [](const ProcMapsEntry& e) {
+    return e.filename == "[vsyscall]";
+  });
+}
+
+}  // namespace testing
+}  // namespace gvisor