Add support for Linux memory mapping stream and remove ELF header usage

when checking exploitability rating.

Linux minidumps do not support MD_MEMORY_INFO_LIST_STREAM, meaning the
processor cannot retrieve its memory mappings. However, it has its own
stream, MD_LINUX_MAPS, which contains memory mappings specific to Linux
(it contains the contents of /proc/self/maps). This CL allows the minidump
to gather information from the memory mappings for Linux minidumps.

In addition, exploitability rating for Linux dumps now use memory mappings
instead of checking the ELF headers of binaries. The basis for the change
is that checking the ELF headers requires the minidumps to store the memory
from the ELF headers, while the memory mapping data is already present,
meaning the size of a minidump will be unchanged.

As a result, of removing ELF header analysis, two unit tests have been removed.
Arguably, the cases that those unit tests check do not merit a high
exploitability rating and do not warrant a solid conclusion that was given
earlier.

R=ivanpe@chromium.org

Review URL: https://codereview.chromium.org/1251593007

git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@1476 4c0a9323-5329-0410-9bdc-e9ce6186880e

1 files changed, 250 insertions, 0 deletions

diff --git a/src/processor/proc_maps_linux_unittest.cc b/src/processor/proc_maps_linux_unittest.cc
new file mode 100644
index 00000000..1ff4b031
--- /dev/null
+++ b/src/processor/proc_maps_linux_unittest.cc
@@ -0,0 +1,250 @@
+// 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 "breakpad_googletest_includes.h"
+#include "google_breakpad/processor/proc_maps_linux.h"
+
+namespace {
+
+TEST(ProcMapsTest, Empty) {
+  std::vector<google_breakpad::MappedMemoryRegion> regions;
+  EXPECT_TRUE(ParseProcMaps("", &regions));
+  EXPECT_EQ(0u, regions.size());
+}
+
+TEST(ProcMapsTest, NoSpaces) {
+  static const char kNoSpaces[] =
+      "00400000-0040b000 r-xp 00002200 fc:00 794418 /bin/cat\n";
+
+  std::vector<google_breakpad::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("/bin/cat", regions[0].path);
+}
+
+TEST(ProcMapsTest, Spaces) {
+  static const char kSpaces[] =
+      "00400000-0040b000 r-xp 00002200 fc:00 794418 /bin/space cat\n";
+
+  std::vector<google_breakpad::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("/bin/space cat", regions[0].path);
+}
+
+TEST(ProcMapsTest, NoNewline) {
+  static const char kNoSpaces[] =
+      "00400000-0040b000 r-xp 00002200 fc:00 794418 /bin/cat";
+
+  std::vector<google_breakpad::MappedMemoryRegion> regions;
+  ASSERT_FALSE(ParseProcMaps(kNoSpaces, &regions));
+}
+
+TEST(ProcMapsTest, NoPath) {
+  static const char kNoPath[] =
+      "00400000-0040b000 rw-p 00000000 00:00 0 \n";
+
+  std::vector<google_breakpad::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("", regions[0].path);
+}
+
+TEST(ProcMapsTest, Heap) {
+  static const char kHeap[] =
+      "022ac000-022cd000 rw-p 00000000 00:00 0 [heap]\n";
+
+  std::vector<google_breakpad::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("[heap]", regions[0].path);
+}
+
+#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<google_breakpad::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("[stack]", regions[0].path);
+}
+#elif defined(ARCH_CPU_64_BITS)
+TEST(ProcMapsTest, Stack64) {
+  static const char kStack[] =
+      "7fff69c5b000-7fff69c7d000 rw-p 00000000 00:00 0 [stack]\n";
+
+  std::vector<google_breakpad::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("[stack]", regions[0].path);
+}
+#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<google_breakpad::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("/bin/cat", regions[0].path);
+
+  EXPECT_EQ(0x0060a000u, regions[1].start);
+  EXPECT_EQ(0x0060b000u, regions[1].end);
+  EXPECT_EQ(0x0000a000u, regions[1].offset);
+  EXPECT_EQ("/bin/cat", regions[1].path);
+
+  EXPECT_EQ(0x0060b000u, regions[2].start);
+  EXPECT_EQ(0x0060c000u, regions[2].end);
+  EXPECT_EQ(0x0000b000u, regions[2].offset);
+  EXPECT_EQ("/bin/cat", regions[2].path);
+}
+
+TEST(ProcMapsTest, Permissions) {
+  static struct {
+    const char* input;
+    uint8_t permissions;
+  } kTestCases[] = {
+    {"00400000-0040b000 ---s 00000000 fc:00 794418 /bin/cat\n", 0},
+    {"00400000-0040b000 ---S 00000000 fc:00 794418 /bin/cat\n", 0},
+    {"00400000-0040b000 r--s 00000000 fc:00 794418 /bin/cat\n",
+      google_breakpad::MappedMemoryRegion::READ},
+    {"00400000-0040b000 -w-s 00000000 fc:00 794418 /bin/cat\n",
+      google_breakpad::MappedMemoryRegion::WRITE},
+    {"00400000-0040b000 --xs 00000000 fc:00 794418 /bin/cat\n",
+      google_breakpad::MappedMemoryRegion::EXECUTE},
+    {"00400000-0040b000 rwxs 00000000 fc:00 794418 /bin/cat\n",
+      google_breakpad::MappedMemoryRegion::READ
+        | google_breakpad::MappedMemoryRegion::WRITE
+        | google_breakpad::MappedMemoryRegion::EXECUTE},
+    {"00400000-0040b000 ---p 00000000 fc:00 794418 /bin/cat\n",
+      google_breakpad::MappedMemoryRegion::PRIVATE},
+    {"00400000-0040b000 r--p 00000000 fc:00 794418 /bin/cat\n",
+      google_breakpad::MappedMemoryRegion::READ
+        | google_breakpad::MappedMemoryRegion::PRIVATE},
+    {"00400000-0040b000 -w-p 00000000 fc:00 794418 /bin/cat\n",
+      google_breakpad::MappedMemoryRegion::WRITE
+        | google_breakpad::MappedMemoryRegion::PRIVATE},
+    {"00400000-0040b000 --xp 00000000 fc:00 794418 /bin/cat\n",
+      google_breakpad::MappedMemoryRegion::EXECUTE
+        | google_breakpad::MappedMemoryRegion::PRIVATE},
+    {"00400000-0040b000 rwxp 00000000 fc:00 794418 /bin/cat\n",
+      google_breakpad::MappedMemoryRegion::READ
+        | google_breakpad::MappedMemoryRegion::WRITE
+        | google_breakpad::MappedMemoryRegion::EXECUTE
+        | google_breakpad::MappedMemoryRegion::PRIVATE},
+  };
+
+  for (size_t i = 0; i < sizeof(kTestCases) / sizeof(kTestCases[0]); ++i) {
+    std::vector<google_breakpad::MappedMemoryRegion> regions;
+    EXPECT_TRUE(ParseProcMaps(kTestCases[i].input, &regions));
+    EXPECT_EQ(1u, regions.size());
+    if (regions.empty())
+      continue;
+    EXPECT_EQ(kTestCases[i].permissions, regions[0].permissions);
+  }
+}
+
+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 < sizeof(kTestCases) / sizeof(kTestCases[0]); ++i) {
+    std::vector<google_breakpad::MappedMemoryRegion> regions;
+    EXPECT_FALSE(ParseProcMaps(kTestCases[i], &regions));
+  }
+}
+
+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 < sizeof(kTestCases) / sizeof(kTestCases[0]); ++i) {
+    std::vector<google_breakpad::MappedMemoryRegion> regions;
+    EXPECT_FALSE(ParseProcMaps(kTestCases[i], &regions));
+  }
+}
+
+TEST(ProcMapsTest, ParseProcMapsEmptyString) {
+  std::vector<google_breakpad::MappedMemoryRegion> regions;
+  EXPECT_TRUE(ParseProcMaps("", &regions));
+  EXPECT_EQ(0ULL, regions.size());
+}
+
+// Testing a couple of remotely possible weird things in the input:
+// - Line ending with \r\n or \n\r.
+// - File name contains quotes.
+// - File name has whitespaces.
+TEST(ProcMapsTest, ParseProcMapsWeirdCorrectInput) {
+  std::vector<google_breakpad::MappedMemoryRegion> regions;
+  const std::string kContents =
+    "00400000-0040b000 r-xp 00000000 fc:00 2106562 "
+      "               /bin/cat\r\n"
+    "7f53b7dad000-7f53b7f62000 r-xp 00000000 fc:00 263011 "
+      "       /lib/x86_64-linux-gnu/libc-2.15.so\n\r"
+    "7f53b816d000-7f53b818f000 r-xp 00000000 fc:00 264284 "
+      "        /lib/x86_64-linux-gnu/ld-2.15.so\n"
+    "7fff9c7ff000-7fff9c800000 r-xp 00000000 00:00 0 "
+      "               \"vd so\"\n"
+    "ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 "
+      "               [vsys call]\n";
+  EXPECT_TRUE(ParseProcMaps(kContents, &regions));
+  EXPECT_EQ(5ULL, regions.size());
+  EXPECT_EQ("/bin/cat", regions[0].path);
+  EXPECT_EQ("/lib/x86_64-linux-gnu/libc-2.15.so", regions[1].path);
+  EXPECT_EQ("/lib/x86_64-linux-gnu/ld-2.15.so", regions[2].path);
+  EXPECT_EQ("\"vd so\"", regions[3].path);
+  EXPECT_EQ("[vsys call]", regions[4].path);
+}
+
+}  // namespace