Linux: Add Breakpad client.

breakpad/linux/exception_handler_unittest.cc

Index: breakpad/linux/exception_handler_unittest.cc
diff --git a/breakpad/linux/exception_handler_unittest.cc b/breakpad/linux/exception_handler_unittest.cc
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+++ b/breakpad/linux/exception_handler_unittest.cc
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+// Copyright (c) 2009, Google Inc.
+// All rights reserved.
+//
+// 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 Inc. 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.
+
+#include <string>
+
+#include <stdint.h>
+#include <unistd.h>
+#include <signal.h>
+#include <sys/poll.h>
+#include <sys/socket.h>
+#include <sys/uio.h>
+
+#include "base/eintr_wrapper.h"
+#include "breakpad/linux/exception_handler.h"
+#include "breakpad/linux/minidump_writer.h"
+#include "breakpad/linux/linux_libc_support.h"
+#include "breakpad/linux/linux_syscall_support.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+using namespace google_breakpad;
+
+static void sigchld_handler(int signo) { }
+
+class ExceptionHandlerTest : public ::testing::Test {
+ protected:
+  void SetUp() {
+    // We need to be able to wait for children, so SIGCHLD cannot be SIG_IGN.
+    struct sigaction sa;
+    memset(&sa, 0, sizeof(sa));
+    sa.sa_handler = sigchld_handler;
+    ASSERT_NE(sigaction(SIGCHLD, &sa, &old_action), -1);
+  }
+
+  void TearDown() {
+    sigaction(SIGCHLD, &old_action, NULL);
+  }
+
+  struct sigaction old_action;
+};
+
+TEST(ExceptionHandlerTest, Simple) {
+  ExceptionHandler handler("/tmp", NULL, NULL, NULL, true);
+}
+
+static bool DoneCallback(const char* dump_path,
+                         const char* minidump_id,
+                         void* context,
+                         bool succeeded) {
+  if (!succeeded)
+    return succeeded;
+
+  int fd = (int) context;
+  uint32_t len = my_strlen(minidump_id);
+  HANDLE_EINTR(sys_write(fd, &len, sizeof(len)));
+  HANDLE_EINTR(sys_write(fd, minidump_id, len));
+  sys_close(fd);
+
+  return true;
+}
+
+TEST(ExceptionHandlerTest, ChildCrash) {
+  int fds[2];
+  ASSERT_NE(pipe(fds), -1);
+
+  const pid_t child = fork();
+  if (child == 0) {
+    close(fds[0]);
+    ExceptionHandler handler("/tmp", NULL, DoneCallback, (void*) fds[1],
+                             true);
+    *reinterpret_cast<int*>(NULL) = 0;
+  }
+  close(fds[1]);
+
+  int status;
+  ASSERT_NE(HANDLE_EINTR(waitpid(child, &status, 0)), -1);
+  ASSERT_TRUE(WIFSIGNALED(status));
+  ASSERT_EQ(WTERMSIG(status), SIGSEGV);
+
+  struct pollfd pfd;
+  memset(&pfd, 0, sizeof(pfd));
+  pfd.fd = fds[0];
+  pfd.events = POLLIN | POLLERR;
+
+  const int r = HANDLE_EINTR(poll(&pfd, 1, 0));
+  ASSERT_EQ(r, 1);
+  ASSERT_TRUE(pfd.revents & POLLIN);
+
+  uint32_t len;
+  ASSERT_EQ(read(fds[0], &len, sizeof(len)), sizeof(len));
+  ASSERT_LT(len, 2048);
+  char* filename = reinterpret_cast<char*>(malloc(len + 1));
+  ASSERT_EQ(read(fds[0], filename, len), len);
+  filename[len] = 0;
+  close(fds[0]);
+
+  const std::string minidump_filename = std::string("/tmp/") + filename +
+                                        ".dmp";
+
+  struct stat st;
+  ASSERT_EQ(stat(minidump_filename.c_str(), &st), 0);
+  ASSERT_GT(st.st_size, 0u);
+  unlink(minidump_filename.c_str());
+}
+
+static const unsigned kControlMsgSize =
+    CMSG_SPACE(sizeof(int)) + CMSG_SPACE(sizeof(struct ucred));
+
+static bool
+CrashHandler(const void* crash_context, size_t crash_context_size,
+             void* context) {
+  const int fd = (int) context;
+  int fds[2];
+  pipe(fds);
+
+  struct kernel_msghdr msg = {0};
+  struct kernel_iovec iov;
+  iov.iov_base = const_cast<void*>(crash_context);
+  iov.iov_len = crash_context_size;
+
+  msg.msg_iov = &iov;
+  msg.msg_iovlen = 1;
+  char cmsg[kControlMsgSize];
+  memset(cmsg, 0, kControlMsgSize);
+  msg.msg_control = cmsg;
+  msg.msg_controllen = sizeof(cmsg);
+
+  struct cmsghdr *hdr = CMSG_FIRSTHDR(&msg);
+  hdr->cmsg_level = SOL_SOCKET;
+  hdr->cmsg_type = SCM_RIGHTS;
+  hdr->cmsg_len = CMSG_LEN(sizeof(int));
+  *((int*) CMSG_DATA(hdr)) = fds[1];
+  hdr = CMSG_NXTHDR((struct msghdr*) &msg, hdr);
+  hdr->cmsg_level = SOL_SOCKET;
+  hdr->cmsg_type = SCM_CREDENTIALS;
+  hdr->cmsg_len = CMSG_LEN(sizeof(struct ucred));
+  struct ucred *cred = reinterpret_cast<struct ucred*>(CMSG_DATA(hdr));
+  cred->uid = getuid();
+  cred->gid = getgid();
+  cred->pid = getpid();
+
+  HANDLE_EINTR(sys_sendmsg(fd, &msg, 0));
+  sys_close(fds[1]);
+
+  char b;
+  HANDLE_EINTR(sys_read(fds[0], &b, 1));
+
+  return true;
+}
+
+TEST(ExceptionHandlerTest, ExternalDumper) {
+  int fds[2];
+  ASSERT_NE(socketpair(AF_UNIX, SOCK_DGRAM, 0, fds), -1);
+  static const int on = 1;
+  setsockopt(fds[0], SOL_SOCKET, SO_PASSCRED, &on, sizeof(on));
+  setsockopt(fds[1], SOL_SOCKET, SO_PASSCRED, &on, sizeof(on));
+
+  const pid_t child = fork();
+  if (child == 0) {
+    close(fds[0]);
+    ExceptionHandler handler("/tmp", NULL, NULL, (void*) fds[1], true);
+    handler.set_crash_handler(CrashHandler);
+    *reinterpret_cast<int*>(NULL) = 0;
+  }
+
+  close(fds[1]);
+  struct msghdr msg = {0};
+  struct iovec iov;
+  static const unsigned kCrashContextSize =
+      sizeof(ExceptionHandler::CrashContext);
+  char context[kCrashContextSize];
+  char control[kControlMsgSize];
+  iov.iov_base = context;
+  iov.iov_len = kCrashContextSize;
+  msg.msg_iov = &iov;
+  msg.msg_iovlen = 1;
+  msg.msg_control = control;
+  msg.msg_controllen = kControlMsgSize;
+
+  const ssize_t n = HANDLE_EINTR(recvmsg(fds[0], &msg, 0));
+  ASSERT_EQ(n, kCrashContextSize);
+  ASSERT_EQ(msg.msg_controllen, kControlMsgSize);
+  ASSERT_EQ(msg.msg_flags, 0);
+
+  pid_t crashing_pid = -1;
+  int signal_fd = -1;
+  for (struct cmsghdr *hdr = CMSG_FIRSTHDR(&msg); hdr;
+       hdr = CMSG_NXTHDR(&msg, hdr)) {
+    if (hdr->cmsg_level != SOL_SOCKET)
+      continue;
+    if (hdr->cmsg_type == SCM_RIGHTS) {
+      const unsigned len = hdr->cmsg_len -
+          (((uint8_t*)CMSG_DATA(hdr)) - (uint8_t*)hdr);
+      ASSERT_EQ(len, sizeof(int));
+      signal_fd = *((int *) CMSG_DATA(hdr));
+    } else if (hdr->cmsg_type == SCM_CREDENTIALS) {
+      const struct ucred *cred =
+          reinterpret_cast<struct ucred*>(CMSG_DATA(hdr));
+      crashing_pid = cred->pid;
+    }
+  }
+
+  ASSERT_NE(crashing_pid, -1);
+  ASSERT_NE(signal_fd, -1);
+
+  char templ[] = "/tmp/exception-handler-unittest-XXXXXX";
+  mktemp(templ);
+  ASSERT_TRUE(WriteMinidump(templ, crashing_pid, context, kCrashContextSize));
+  static const char b = 0;
+  HANDLE_EINTR(write(signal_fd, &b, 1));
+
+  int status;
+  ASSERT_NE(HANDLE_EINTR(waitpid(child, &status, 0)), -1);
+  ASSERT_TRUE(WIFSIGNALED(status));
+  ASSERT_EQ(WTERMSIG(status), SIGSEGV);
+
+  struct stat st;
+  ASSERT_EQ(stat(templ, &st), 0);
+  ASSERT_GT(st.st_size, 0u);
+  unlink(templ);
+}