Implement /proc/self/maps/ parsing code.

base/debug/proc_maps_unittest.cc

Index: base/debug/proc_maps_unittest.cc
diff --git a/base/debug/proc_maps_unittest.cc b/base/debug/proc_maps_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..a67be6bc9633565d9a77ed80c47951d87d8ccf34
--- /dev/null
+++ b/base/debug/proc_maps_unittest.cc
@@ -0,0 +1,229 @@
+// Copyright (c) 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "base/debug/proc_maps.h"
+#include "base/logging.h"
+#include "base/strings/stringprintf.h"
+#include "build/build_config.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace base {
+namespace debug {

[Mark Mentovai, 2013/07/02 19:36:57]

Ditto on the inner nested namespace.

+
+#if defined(OS_LINUX) || defined(OS_ANDROID)
+
+TEST(ProcMapsTest, NoSpaces) {
+  static const char kNoSpaces[] =
+      "00400000-0040b000 r-xp 00002200 fc:00 794418 /bin/cat\n";
+
+  std::vector<MappedMemoryRegion> regions;
+  ASSERT_TRUE(ParseProcMaps(kNoSpaces, &regions));
+  ASSERT_EQ(1u, regions.size());
+
+  EXPECT_EQ(0x00400000u, regions[0].start);
+  EXPECT_EQ(0x0040b000u, regions[0].end);
+  EXPECT_EQ(0x00002200u, regions[0].offset);
+  EXPECT_EQ(FilePath("/bin/cat").value(), regions[0].path.value());
+}
+
+TEST(ProcMapsTest, Spaces) {
+  static const char kSpaces[] =
+      "00400000-0040b000 r-xp 00002200 fc:00 794418 /bin/space cat\n";
+
+  std::vector<MappedMemoryRegion> regions;
+  ASSERT_TRUE(ParseProcMaps(kSpaces, &regions));
+  ASSERT_EQ(1u, regions.size());
+
+  EXPECT_EQ(0x00400000u, regions[0].start);
+  EXPECT_EQ(0x0040b000u, regions[0].end);
+  EXPECT_EQ(0x00002200u, regions[0].offset);
+  EXPECT_EQ(FilePath("/bin/space cat").value(), regions[0].path.value());
+}
+
+TEST(ProcMapsTest, NoPath) {
+  static const char kNoPath[] =
+      "00400000-0040b000 rw-p 00000000 00:00 0 \n";
+
+  std::vector<MappedMemoryRegion> regions;
+  ASSERT_TRUE(ParseProcMaps(kNoPath, &regions));
+  ASSERT_EQ(1u, regions.size());
+
+  EXPECT_EQ(0x00400000u, regions[0].start);
+  EXPECT_EQ(0x0040b000u, regions[0].end);
+  EXPECT_EQ(0x00000000u, regions[0].offset);
+  EXPECT_EQ(FilePath().value(), regions[0].path.value());
+}
+
+TEST(ProcMapsTest, Heap) {
+  static const char kHeap[] =
+      "022ac000-022cd000 rw-p 00000000 00:00 0 [heap]\n";
+
+  std::vector<MappedMemoryRegion> regions;
+  ASSERT_TRUE(ParseProcMaps(kHeap, &regions));
+  ASSERT_EQ(1u, regions.size());
+
+  EXPECT_EQ(0x022ac000u, regions[0].start);
+  EXPECT_EQ(0x022cd000u, regions[0].end);
+  EXPECT_EQ(0x00000000u, regions[0].offset);
+  EXPECT_EQ(FilePath("[heap]").value(), regions[0].path.value());
+}
+
+#if defined(ARCH_CPU_32_BITS)
+TEST(ProcMapsTest, Stack32) {
+  static const char kStack[] =
+      "beb04000-beb25000 rw-p 00000000 00:00 0 [stack]\n";
+
+  std::vector<MappedMemoryRegion> regions;
+  ASSERT_TRUE(ParseProcMaps(kStack, &regions));
+  ASSERT_EQ(1u, regions.size());
+
+  EXPECT_EQ(0xbeb04000u, regions[0].start);
+  EXPECT_EQ(0xbeb25000u, regions[0].end);
+  EXPECT_EQ(0x00000000u, regions[0].offset);
+  EXPECT_EQ(FilePath("[stack]").value(), regions[0].path.value());
+}
+#endif
+
+#if defined(ARCH_CPU_64_BITS)

[Mark Mentovai, 2013/07/02 19:36:57]

#elif makes it clear that this is the same test but for a different
architecture.

[scherkus (not reviewing), 2013/07/02 21:43:01]

Done.

+TEST(ProcMapsTest, Stack64) {
+  static const char kStack[] =
+      "7fff69c5b000-7fff69c7d000 rw-p 00000000 00:00 0 [stack]\n";
+
+  std::vector<MappedMemoryRegion> regions;
+  ASSERT_TRUE(ParseProcMaps(kStack, &regions));
+  ASSERT_EQ(1u, regions.size());
+
+  EXPECT_EQ(0x7fff69c5b000u, regions[0].start);
+  EXPECT_EQ(0x7fff69c7d000u, regions[0].end);
+  EXPECT_EQ(0x00000000u, regions[0].offset);
+  EXPECT_EQ(FilePath("[stack]").value(), regions[0].path.value());
+}
+#endif
+
+TEST(ProcMapsTest, Multiple) {
+  static const char kMultiple[] =
+      "00400000-0040b000 r-xp 00000000 fc:00 794418 /bin/cat\n"
+      "0060a000-0060b000 r--p 0000a000 fc:00 794418 /bin/cat\n"
+      "0060b000-0060c000 rw-p 0000b000 fc:00 794418 /bin/cat\n";
+
+  std::vector<MappedMemoryRegion> regions;
+  ASSERT_TRUE(ParseProcMaps(kMultiple, &regions));
+  ASSERT_EQ(3u, regions.size());
+
+  EXPECT_EQ(0x00400000u, regions[0].start);
+  EXPECT_EQ(0x0040b000u, regions[0].end);
+  EXPECT_EQ(0x00000000u, regions[0].offset);
+  EXPECT_EQ(FilePath("/bin/cat").value(), regions[0].path.value());
+
+  EXPECT_EQ(0x0060a000u, regions[1].start);
+  EXPECT_EQ(0x0060b000u, regions[1].end);
+  EXPECT_EQ(0x0000a000u, regions[1].offset);
+  EXPECT_EQ(FilePath("/bin/cat").value(), regions[1].path.value());
+
+  EXPECT_EQ(0x0060b000u, regions[2].start);
+  EXPECT_EQ(0x0060c000u, regions[2].end);
+  EXPECT_EQ(0x0000b000u, regions[2].offset);
+  EXPECT_EQ(FilePath("/bin/cat").value(), regions[2].path.value());
+}
+
+TEST(ProcMapsTest, Permissions) {
+  static struct {
+    const char* input;
+    int permissions;

[Mark Mentovai, 2013/07/02 19:36:57]

You can call this a uint8 to match what it is in the struct.

[scherkus (not reviewing), 2013/07/02 21:43:01]

Done.

+  } kTestCases[] = {
+    {"00400000-0040b000 ---s 00000000 fc:00 794418 /bin/cat\n", 0},
+    {"00400000-0040b000 r--s 00000000 fc:00 794418 /bin/cat\n",
+     MappedMemoryRegion::READ},
+    {"00400000-0040b000 -w-s 00000000 fc:00 794418 /bin/cat\n",
+     MappedMemoryRegion::WRITE},
+    {"00400000-0040b000 --xs 00000000 fc:00 794418 /bin/cat\n",
+     MappedMemoryRegion::EXECUTE},
+    {"00400000-0040b000 rwxs 00000000 fc:00 794418 /bin/cat\n",
+     MappedMemoryRegion::READ | MappedMemoryRegion::WRITE |
+         MappedMemoryRegion::EXECUTE},
+    {"00400000-0040b000 ---p 00000000 fc:00 794418 /bin/cat\n",
+     MappedMemoryRegion::PRIVATE},
+    {"00400000-0040b000 r--p 00000000 fc:00 794418 /bin/cat\n",
+     MappedMemoryRegion::READ | MappedMemoryRegion::PRIVATE},
+    {"00400000-0040b000 -w-p 00000000 fc:00 794418 /bin/cat\n",
+     MappedMemoryRegion::WRITE | MappedMemoryRegion::PRIVATE},
+    {"00400000-0040b000 --xp 00000000 fc:00 794418 /bin/cat\n",
+     MappedMemoryRegion::EXECUTE | MappedMemoryRegion::PRIVATE},
+    {"00400000-0040b000 rwxp 00000000 fc:00 794418 /bin/cat\n",
+     MappedMemoryRegion::READ | MappedMemoryRegion::WRITE |
+         MappedMemoryRegion::EXECUTE | MappedMemoryRegion::PRIVATE},
+    { NULL, 0 },
+  };
+
+  for (size_t i = 0; kTestCases[i].input != NULL; ++i) {

[Mark Mentovai, 2013/07/02 19:36:57]

Why not just use arraysize (like you did for the last two tests in this file)
and get rid of the null entry?

[scherkus (not reviewing), 2013/07/02 21:43:01]

arraysize() doesn't work with anonymous struct types:

error: template argument uses local type '<anonymous struct at
../../base/debug/proc_maps_linux_unittest.cc:140:10>'
[-Werror,-Wlocal-type-template-args]

options:
  1) declare this struct in an anonymous namespace
  2) wait for c++11
  3) nothing

[Mark Mentovai, 2013/07/02 22:21:35]

scherkus wrote:
4) ARRAYSIZE_UNSAFE

Your call

[scherkus (not reviewing), 2013/07/02 23:07:47]

The More You Know(tm)

Done. (I'm an arraysize fan)

+    SCOPED_TRACE(
+        base::StringPrintf("kTestCases[%zu] = %s", i, kTestCases[i].input));
+
+    std::vector<MappedMemoryRegion> regions;
+    ASSERT_TRUE(ParseProcMaps(kTestCases[i].input, &regions));

[Mark Mentovai, 2013/07/02 19:36:57]

On one hand, I think these should be EXPECT, because there’s no point in
stopping the test loop just because one of these failed. On the other hand, I
see how within a pass of the loop, each EXPECT/ASSERT builds on the one that
came before it. Your call.

[scherkus (not reviewing), 2013/07/02 21:43:01]

agreed -- changed to EXPECT + added check to verify we won't crash when
accessing regions[0]

+    ASSERT_EQ(1u, regions.size());
+    EXPECT_EQ(kTestCases[i].permissions, regions[0].permissions);
+  }
+}
+
+TEST(ProcMapsTest, ReadProcMaps) {
+  std::vector<MappedMemoryRegion> regions;
+  ASSERT_TRUE(ParseProcMaps(ReadProcMaps(), &regions));

[Mark Mentovai, 2013/07/02 19:36:57]

I’d break this into two checked operations so that if it fails, you’ll know
whether the read failed or the parse failed.

[scherkus (not reviewing), 2013/07/02 21:43:01]

Done.

+  ASSERT_FALSE(regions.empty());
+
+  // We should be find some mention of base_unittests in one of the paths.
+  bool found_base_unittests = false;
+  for (size_t i = 0; i < regions.size(); ++i) {
+    if (regions[i].path.value().find("base_unittests") != std::string::npos) {

[Mark Mentovai, 2013/07/02 19:36:57]

There’s got to be a better way to figure out your executable’s basename than
hardcoding it. You can readlink /proc/self/exe and take its basename, for
example.

[scherkus (not reviewing), 2013/07/02 21:43:01]

hrmm... while this will work for linux it's trickier on android as
base_unittests is linked as libbase_unittestslib.cr.so and invoked via JNI

I reworked this to look for where our stack is mapped in memory. It's slightly
more portable / less hardcoded, but I'm open to ideas :\

[Mark Mentovai, 2013/07/02 22:21:35]

scherkus wrote:
Well, it would have been OK to use /proc/self/exe (if it exists on Android) even
if it didn’t have base_unittests in its name. The main executable still should
show up in /proc/self/maps.

Maybe you even want to look for both /proc/self/exe and the stack.

[scherkus (not reviewing), 2013/07/02 23:07:47]

Looks like PathService w/ FILE_EXE does a readlink() on /proc/self/exe

Added test + confirmed working on Linux and Android. Score.

+      found_base_unittests = true;
+      break;
+    }
+  }
+
+  EXPECT_TRUE(found_base_unittests);
+}
+
+TEST(ProcMapsTest, MissingFields) {
+  static const char* kTestCases[] = {
+    "00400000\n",                               // Missing end + beyond.
+    "00400000-0040b000\n",                      // Missing perms + beyond.
+    "00400000-0040b000 r-xp\n",                 // Missing offset + beyond.
+    "00400000-0040b000 r-xp 00000000\n",        // Missing device + beyond.
+    "00400000-0040b000 r-xp 00000000 fc:00\n",  // Missing inode + beyond.
+    "00400000-0040b000 00000000 fc:00 794418 /bin/cat\n",  // Missing perms.
+    "00400000-0040b000 r-xp fc:00 794418 /bin/cat\n",      // Missing offset.
+    "00400000-0040b000 r-xp 00000000 fc:00 /bin/cat\n",    // Missing inode.
+    "00400000 r-xp 00000000 fc:00 794418 /bin/cat\n",      // Missing end.
+    "-0040b000 r-xp 00000000 fc:00 794418 /bin/cat\n",     // Missing start.
+    "00400000-0040b000 r-xp 00000000 794418 /bin/cat\n",   // Missing device.
+  };
+
+  for (size_t i = 0; i < arraysize(kTestCases); ++i) {
+    SCOPED_TRACE(base::StringPrintf("kTestCases[%zu] = %s", i, kTestCases[i]));
+    std::vector<MappedMemoryRegion> regions;
+    ASSERT_FALSE(ParseProcMaps(kTestCases[i], &regions));

[Mark Mentovai, 2013/07/02 19:36:57]

This one should be EXPECT, and so should line 220.

[scherkus (not reviewing), 2013/07/02 21:43:01]

Done.

+  }
+}
+
+TEST(ProcMapsTest, InvalidInput) {
+  static const char* kTestCases[] = {
+    "thisisal-0040b000 rwxp 00000000 fc:00 794418 /bin/cat\n",
+    "0040000d-linvalid rwxp 00000000 fc:00 794418 /bin/cat\n",
+    "00400000-0040b000 inpu 00000000 fc:00 794418 /bin/cat\n",
+    "00400000-0040b000 rwxp tforproc fc:00 794418 /bin/cat\n",
+    "00400000-0040b000 rwxp 00000000 ma:ps 794418 /bin/cat\n",
+    "00400000-0040b000 rwxp 00000000 fc:00 parse! /bin/cat\n",
+  };
+
+  for (size_t i = 0; i < arraysize(kTestCases); ++i) {
+    SCOPED_TRACE(base::StringPrintf("kTestCases[%zu] = %s", i, kTestCases[i]));
+    std::vector<MappedMemoryRegion> regions;
+    ASSERT_FALSE(ParseProcMaps(kTestCases[i], &regions));
+  }
+}
+
+#endif
+
+}  // namespace debug
+}  // namespace base

[Mark Mentovai, 2013/07/02 19:36:57]

This is a really good and comprehensive test, nice job!