Microdumps: support aarch64 and lib mapping from APK

- Filter modules by prot flags (only +x) not extensions. It wouldn't
  otherwise catch the case of Chrome mapping the library from the
  apk (which is mapped r-x but doesn't end in .so).
- Use compile-time detection of target arch, in order to cope with
  multilib OSes, where uname() doesn't reflect the run-time arch.
- Add OS information and CPU arch / count.
- Add support for aarch64.
- Add tests and stackwalk expectations for aarch64.
- Fix a potential overflow bug in the processor.
- Rebaseline the tests using smaller symbols.
- Fix microdump_writer_unittest.cc on 32-bit host.

BUG=chromium:410294

git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@1407 4c0a9323-5329-0410-9bdc-e9ce6186880e

2 files changed, 36 insertions, 10 deletions

diff --git a/src/client/linux/microdump_writer/microdump_writer.cc b/src/client/linux/microdump_writer/microdump_writer.cc
index 195255f7..48016b02 100644
--- a/src/client/linux/microdump_writer/microdump_writer.cc
+++ b/src/client/linux/microdump_writer/microdump_writer.cc
@@ -143,21 +143,42 @@ class MicrodumpWriter {
     struct utsname uts;
     if (uname(&uts))
       return false;
+    const uint8_t n_cpus = static_cast<uint8_t>(sysconf(_SC_NPROCESSORS_CONF));
 
 #if defined(__ANDROID__)
     const char kOSId[] = "A";
 #else
     const char kOSId[] = "L";
 #endif
+
+// We cannot depend on uts.machine. On multiarch devices it always returns the
+// primary arch, not the one that match the executable being run.
+#if defined(__aarch64__)
+    const char kArch[] = "arm64";
+#elif defined(__ARMEL__)
+    const char kArch[] = "arm";
+#elif defined(__x86_64__)
+    const char kArch[] = "x86_64";
+#elif defined(__i386__)
+    const char kArch[] = "x86";
+#elif defined(__mips__)
+    const char kArch[] = "mips";
+#else
+#error "This code has not been ported to your platform yet"
+#endif
+
     LogAppend("O ");
     LogAppend(kOSId);
-    LogAppend(" \"");
+    LogAppend(" ");
+    LogAppend(kArch);
+    LogAppend(" ");
+    LogAppend(n_cpus);
+    LogAppend(" ");
     LogAppend(uts.machine);
-    LogAppend("\" \"");
+    LogAppend(" ");
     LogAppend(uts.release);
-    LogAppend(" \"");
+    LogAppend(" ");
     LogAppend(uts.version);
-    LogAppend("\"");
     LogCommitLine();
     return true;
   }
@@ -316,15 +337,13 @@ class MicrodumpWriter {
     // First write all the mappings from the dumper
     for (unsigned i = 0; i < dumper_->mappings().size(); ++i) {
       const MappingInfo& mapping = *dumper_->mappings()[i];
-      // Skip mappings which don't look like libraries.
-      if (!strstr(mapping.name, ".so") ||  // dump only libs (skip fonts, apks).
-          mapping.size < 4096) { // too small to get a signature for.
+      if (mapping.name[0] == 0 ||  // only want modules with filenames.
+          !mapping.exec ||  // only want executable mappings.
+          mapping.size < 4096 || // too small to get a signature for.
+          HaveMappingInfo(mapping)) {
         continue;
       }
 
-      if (HaveMappingInfo(mapping))
-        continue;
-
       DumpModule(mapping, true, i, NULL);
     }
     // Next write all the mappings provided by the caller
diff --git a/src/client/linux/microdump_writer/microdump_writer_unittest.cc b/src/client/linux/microdump_writer/microdump_writer_unittest.cc
index 27b23a7d..70543c69 100644
--- a/src/client/linux/microdump_writer/microdump_writer_unittest.cc
+++ b/src/client/linux/microdump_writer/microdump_writer_unittest.cc
@@ -119,9 +119,16 @@ TEST(MicrodumpWriterTest, Setup) {
       buf.get(), "-----BEGIN BREAKPAD MICRODUMP-----"));
   ASSERT_NE(static_cast<char*>(0), strstr(
       buf.get(), "-----END BREAKPAD MICRODUMP-----"));
+
+#ifdef __LP64__
   ASSERT_NE(static_cast<char*>(0), strstr(
       buf.get(), "M 0000000000001000 000000000000002A 0000000000001000 "
       "33221100554477668899AABBCCDDEEFF0 libfoo.so"));
+#else
+  ASSERT_NE(static_cast<char*>(0), strstr(
+      buf.get(), "M 00001000 0000002A 00001000 "
+      "33221100554477668899AABBCCDDEEFF0 libfoo.so"));
+#endif
 
   close(err_fd);
   close(fds[1]);