crash-reporter: add filtering to make crash tests resilient to crashy builds

user_collector.cc

 // Copyright (c) 2010 The Chromium OS 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 "crash-reporter/user_collector.h"
 
 #include <fcntl.h>  // For creat.
 #include <grp.h>  // For struct group.
 #include <pwd.h>  // For struct passwd.
 #include <sys/types.h>  // For getpwuid_r, getgrnam_r, WEXITSTATUS.
 #include <sys/wait.h>  // For waitpid.
 #include <unistd.h>  // For execv and fork.
 
 #include <string>
 #include <vector>
 
 #include "base/eintr_wrapper.h"
 #include "base/file_util.h"
 #include "base/logging.h"
 #include "base/string_util.h"
 #include "crash-reporter/system_logging.h"
 #include "gflags/gflags.h"
 
+#pragma GCC diagnostic ignored "-Wstrict-aliasing"
 DEFINE_bool(core2md_failure_test, false, "Core2md failure test");
 DEFINE_bool(directory_failure_test, false, "Spool directory failure test");
+DEFINE_string(filter_in, "",
+              "Ignore all crashes but this for testing");
+#pragma GCC diagnostic error "-Wstrict-aliasing"
 
 static const char kCollectionErrorSignature[] =
     "crash_reporter-user-collection";
 // This procfs file is used to cause kernel core file writing to
 // instead pipe the core file into a user space process.  See
 // core(5) man page.
 static const char kCorePatternFile[] = "/proc/sys/kernel/core_pattern";
 static const char kCoreToMinidumpConverterPath[] = "/usr/bin/core2md";
 static const char kLeaveCoreFile[] = "/root/.leave_core";
 
@@ skipping 380 matching lines @@
 bool UserCollector::HandleCrash(int signal, int pid, const char *force_exec) {
   CHECK(initialized_);
   std::string exec;
   if (force_exec) {
     exec.assign(force_exec);
   } else if (!GetExecutableBaseNameFromPid(pid, &exec)) {
     // If for some reason we don't have the base name, avoid completely
     // failing by indicating an unknown name.
     exec = "unknown";
   }
+
+  // Allow us to test the crash reporting mechanism successfully even if
+  // other parts of the system crash.
+  if (!FLAGS_filter_in.empty() &&
+      (FLAGS_filter_in == "none" ||
+       FLAGS_filter_in != exec)) {
+    // We use a different format message to make it more obvious in tests
+    // which crashes are test generated and which are real.
+    logger_->LogWarning("Ignoring crash from %s[%d] while filter_in=%s",
+                        exec.c_str(), pid, FLAGS_filter_in.c_str());
+    return true;
+  }
+
   bool feedback = is_feedback_allowed_function_();
   logger_->LogWarning("Received crash notification for %s[%d] sig %d (%s)",
                       exec.c_str(), pid, signal,
                       feedback ? "handling" : "ignoring - no consent");
 
   if (feedback) {
     count_crash_function_();
 
     if (generate_diagnostics_) {
       bool out_of_capacity = false;
       if (!ConvertAndEnqueueCrash(pid, exec, &out_of_capacity)) {
         if (!out_of_capacity)
           EnqueueCollectionErrorLog(pid, exec);
         return false;
       }
     }
   }
 
   return true;
 }