1 files changed, 341 insertions, 0 deletions
diff --git a/externals/breakpad/src/common/linux/tests/crash_generator.cc b/externals/breakpad/src/common/linux/tests/crash_generator.cc
new file mode 100644
index 0000000000..1cad9ae26b
--- /dev/null
+++ b/externals/breakpad/src/common/linux/tests/crash_generator.cc
@@ -0,0 +1,341 @@
+// Copyright 2011 Google LLC
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google LLC nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// crash_generator.cc: Implement google_breakpad::CrashGenerator.
+// See crash_generator.h for details.
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>  // Must come first
+#endif
+
+#include "common/linux/tests/crash_generator.h"
+
+#include <pthread.h>
+#include <sched.h>
+#include <signal.h>
+#include <stdio.h>
+#include <sys/mman.h>
+#include <sys/resource.h>
+#include <sys/syscall.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#include <string>
+
+#if defined(__ANDROID__)
+#include "common/android/testing/pthread_fixes.h"
+#endif
+#include "common/linux/eintr_wrapper.h"
+#include "common/tests/auto_tempdir.h"
+#include "common/tests/file_utils.h"
+#include "common/using_std_string.h"
+
+namespace {
+
+struct ThreadData {
+  pthread_t thread;
+  pthread_barrier_t* barrier;
+  pid_t* thread_id_ptr;
+};
+
+const char* const kProcFilesToCopy[] = {
+  "auxv", "cmdline", "environ", "maps", "status"
+};
+const size_t kNumProcFilesToCopy =
+    sizeof(kProcFilesToCopy) / sizeof(kProcFilesToCopy[0]);
+
+int gettid() {
+  // Glibc does not provide a wrapper for this.
+  return syscall(__NR_gettid);
+}
+
+int tkill(pid_t tid, int sig) {
+  // Glibc does not provide a wrapper for this.
+  return syscall(__NR_tkill, tid, sig);
+}
+
+// Core file size limit set to 1 MB, which is big enough for test purposes.
+const rlim_t kCoreSizeLimit = 1024 * 1024;
+
+void* thread_function(void* data) {
+  ThreadData* thread_data = reinterpret_cast<ThreadData*>(data);
+  volatile pid_t thread_id = gettid();
+  *(thread_data->thread_id_ptr) = thread_id;
+  int result = pthread_barrier_wait(thread_data->barrier);
+  if (result != 0 && result != PTHREAD_BARRIER_SERIAL_THREAD) {
+    perror("Failed to wait for sync barrier");
+    exit(1);
+  }
+  while (true) {
+    sched_yield();
+  }
+}
+
+}  // namespace
+
+namespace google_breakpad {
+
+CrashGenerator::CrashGenerator()
+    : shared_memory_(NULL),
+      shared_memory_size_(0) {
+}
+
+CrashGenerator::~CrashGenerator() {
+  UnmapSharedMemory();
+}
+
+bool CrashGenerator::HasDefaultCorePattern() const {
+  char buffer[8];
+  ssize_t buffer_size = sizeof(buffer);
+  return ReadFile("/proc/sys/kernel/core_pattern", buffer, &buffer_size) &&
+         buffer_size == 5 && memcmp(buffer, "core", 4) == 0;
+}
+
+string CrashGenerator::GetCoreFilePath() const {
+  return temp_dir_.path() + "/core";
+}
+
+string CrashGenerator::GetDirectoryOfProcFilesCopy() const {
+  return temp_dir_.path() + "/proc";
+}
+
+pid_t CrashGenerator::GetThreadId(unsigned index) const {
+  return reinterpret_cast<pid_t*>(shared_memory_)[index];
+}
+
+pid_t* CrashGenerator::GetThreadIdPointer(unsigned index) {
+  return reinterpret_cast<pid_t*>(shared_memory_) + index;
+}
+
+bool CrashGenerator::MapSharedMemory(size_t memory_size) {
+  if (!UnmapSharedMemory())
+    return false;
+
+  void* mapped_memory = mmap(0, memory_size, PROT_READ | PROT_WRITE,
+                             MAP_SHARED | MAP_ANONYMOUS, -1, 0);
+  if (mapped_memory == MAP_FAILED) {
+    perror("CrashGenerator: Failed to map shared memory");
+    return false;
+  }
+
+  memset(mapped_memory, 0, memory_size);
+  shared_memory_ = mapped_memory;
+  shared_memory_size_ = memory_size;
+  return true;
+}
+
+bool CrashGenerator::UnmapSharedMemory() {
+  if (!shared_memory_)
+    return true;
+
+  if (munmap(shared_memory_, shared_memory_size_) == 0) {
+    shared_memory_ = NULL;
+    shared_memory_size_ = 0;
+    return true;
+  }
+
+  perror("CrashGenerator: Failed to unmap shared memory");
+  return false;
+}
+
+bool CrashGenerator::SetCoreFileSizeLimit(rlim_t limit) const {
+  struct rlimit limits = { limit, limit };
+  if (setrlimit(RLIMIT_CORE, &limits) == -1) {
+    perror("CrashGenerator: Failed to set core file size limit");
+    return false;
+  }
+  return true;
+}
+
+bool CrashGenerator::HasResourceLimitsAmenableToCrashCollection() const {
+  struct rlimit limits;
+  if (getrlimit(RLIMIT_CORE, &limits) == -1) {
+    perror("CrashGenerator: Failed to get core file size limit");
+    return false;
+  }
+  return limits.rlim_max >= kCoreSizeLimit;
+}
+
+bool CrashGenerator::CreateChildCrash(
+    unsigned num_threads, unsigned crash_thread, int crash_signal,
+    pid_t* child_pid) {
+  if (num_threads == 0 || crash_thread >= num_threads) {
+    fprintf(stderr, "CrashGenerator: Invalid thread counts; num_threads=%u"
+                    " crash_thread=%u\n", num_threads, crash_thread);
+    return false;
+  }
+
+  if (!MapSharedMemory(num_threads * sizeof(pid_t))) {
+    perror("CrashGenerator: Unable to map shared memory");
+    return false;
+  }
+
+  pid_t pid = fork();
+  if (pid == 0) {
+    // Custom signal handlers, which may have been installed by a test launcher,
+    // are undesirable in this child.
+    if (signal(crash_signal, SIG_DFL) == SIG_ERR) {
+      perror("CrashGenerator: signal");
+      exit(1);
+    }
+    if (chdir(temp_dir_.path().c_str()) == -1) {
+      perror("CrashGenerator: Failed to change directory");
+      exit(1);
+    }
+    if (SetCoreFileSizeLimit(kCoreSizeLimit)) {
+      CreateThreadsInChildProcess(num_threads);
+      string proc_dir = GetDirectoryOfProcFilesCopy();
+      if (mkdir(proc_dir.c_str(), 0755) == -1) {
+        perror("CrashGenerator: Failed to create proc directory");
+        exit(1);
+      }
+      if (!CopyProcFiles(getpid(), proc_dir.c_str())) {
+        fprintf(stderr, "CrashGenerator: Failed to copy proc files\n");
+        exit(1);
+      }
+      // On Android the signal sometimes doesn't seem to get sent even though
+      // tkill returns '0'.  Retry a couple of times if the signal doesn't get
+      // through on the first go:
+      // https://bugs.chromium.org/p/google-breakpad/issues/detail?id=579
+#if defined(__ANDROID__)
+      const int kRetries = 60;
+      const unsigned int kSleepTimeInSeconds = 1;
+#else
+      const int kRetries = 1;
+      const unsigned int kSleepTimeInSeconds = 600;
+#endif
+      for (int i = 0; i < kRetries; i++) {
+        if (tkill(*GetThreadIdPointer(crash_thread), crash_signal) == -1) {
+          perror("CrashGenerator: Failed to kill thread by signal");
+        } else {
+          // At this point, we've queued the signal for delivery, but there's no
+          // guarantee when it'll be delivered.  We don't want the main thread to
+          // race and exit before the thread we signaled is processed.  So sleep
+          // long enough that we won't flake even under fairly high load.
+          // TODO: See if we can't be a bit more deterministic.  There doesn't
+          // seem to be an API to check on signal delivery status, so we can't
+          // really poll and wait for the kernel to declare the signal has been
+          // delivered.  If it has, and things worked, we'd be killed, so the
+          // sleep length doesn't really matter.
+          sleep(kSleepTimeInSeconds);
+        }
+      }
+    } else {
+      perror("CrashGenerator: Failed to set core limit");
+    }
+    exit(1);
+  } else if (pid == -1) {
+    perror("CrashGenerator: Failed to create child process");
+    return false;
+  }
+
+  int status;
+  if (HANDLE_EINTR(waitpid(pid, &status, 0)) == -1) {
+    perror("CrashGenerator: Failed to wait for child process");
+    return false;
+  }
+  if (!WIFSIGNALED(status) || WTERMSIG(status) != crash_signal) {
+    fprintf(stderr, "CrashGenerator: Child process not killed by the expected signal\n"
+                    "  exit status=0x%x pid=%u signaled=%s sig=%d expected=%d\n",
+                    status, pid, WIFSIGNALED(status) ? "true" : "false",
+                    WTERMSIG(status), crash_signal);
+    return false;
+  }
+
+  if (child_pid)
+    *child_pid = pid;
+  return true;
+}
+
+bool CrashGenerator::CopyProcFiles(pid_t pid, const char* path) const {
+  char from_path[PATH_MAX], to_path[PATH_MAX];
+  for (size_t i = 0; i < kNumProcFilesToCopy; ++i) {
+    int num_chars = snprintf(from_path, PATH_MAX, "/proc/%d/%s",
+                             pid, kProcFilesToCopy[i]);
+    if (num_chars < 0 || num_chars >= PATH_MAX)
+      return false;
+
+    num_chars = snprintf(to_path, PATH_MAX, "%s/%s",
+                         path, kProcFilesToCopy[i]);
+    if (num_chars < 0 || num_chars >= PATH_MAX)
+      return false;
+
+    if (!CopyFile(from_path, to_path))
+      return false;
+  }
+  return true;
+}
+
+void CrashGenerator::CreateThreadsInChildProcess(unsigned num_threads) {
+  *GetThreadIdPointer(0) = getpid();
+
+  if (num_threads <= 1)
+    return;
+
+  // This method does not clean up any pthread resource, as the process
+  // is expected to be killed anyway.
+  ThreadData* thread_data = new ThreadData[num_threads];
+
+  // Create detached threads so that we do not worry about pthread_join()
+  // later being called or not.
+  pthread_attr_t thread_attributes;
+  if (pthread_attr_init(&thread_attributes) != 0 ||
+      pthread_attr_setdetachstate(&thread_attributes,
+                                  PTHREAD_CREATE_DETACHED) != 0) {
+    fprintf(stderr, "CrashGenerator: Failed to initialize thread attribute\n");
+    exit(1);
+  }
+
+  pthread_barrier_t thread_barrier;
+  if (pthread_barrier_init(&thread_barrier, NULL, num_threads) != 0) {
+    fprintf(stderr, "CrashGenerator: Failed to initialize thread barrier\n");
+    exit(1);
+  }
+
+  for (unsigned i = 1; i < num_threads; ++i) {
+    thread_data[i].barrier = &thread_barrier;
+    thread_data[i].thread_id_ptr = GetThreadIdPointer(i);
+    if (pthread_create(&thread_data[i].thread, &thread_attributes,
+                       thread_function, &thread_data[i]) != 0) {
+      fprintf(stderr, "CrashGenerator: Failed to create thread %d\n", i);
+      exit(1);
+    }
+  }
+
+  int result = pthread_barrier_wait(&thread_barrier);
+  if (result != 0 && result != PTHREAD_BARRIER_SERIAL_THREAD) {
+    fprintf(stderr, "CrashGenerator: Failed to wait for thread barrier\n");
+    exit(1);
+  }
+
+  pthread_barrier_destroy(&thread_barrier);
+  pthread_attr_destroy(&thread_attributes);
+  delete[] thread_data;
+}
+
+}  // namespace google_breakpad