Linux: Guess the thread id for crashing renderers in a different PID namespac...

chrome/app/breakpad_linux.cc

 // Copyright (c) 2010 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 "chrome/app/breakpad_linux.h"
 
 #include <fcntl.h>
 #include <stdlib.h>
 #include <sys/socket.h>
 #include <sys/time.h>
@@ skipping 661 matching lines @@
   const size_t guid_len = std::min(google_update::posix_guid.size(),
                                    kGuidSize);
   const size_t crash_url_len =
       std::min(child_process_logging::active_url.size(), kMaxActiveURLSize);
   const size_t distro_len =
       std::min(base::linux_distro.size(), kDistroSize);
   memcpy(guid, google_update::posix_guid.data(), guid_len);
   memcpy(crash_url, child_process_logging::active_url.data(), crash_url_len);
   memcpy(distro, base::linux_distro.data(), distro_len);
 
+  char b;  // Dummy variable for sys_read below.
+  const char* b_addr = &b;  // Get the address of |b| so we can create the
+                            // expected /proc/[pid]/syscall content in the
+                            // browser to convert namespace tids.
+
   // The length of the control message:
   static const unsigned kControlMsgSize = CMSG_SPACE(sizeof(int));
 
   struct kernel_msghdr msg;
   my_memset(&msg, 0, sizeof(struct kernel_msghdr));
-  struct kernel_iovec iov[4];
+  struct kernel_iovec iov[6];
   iov[0].iov_base = const_cast<void*>(crash_context);
   iov[0].iov_len = crash_context_size;
   iov[1].iov_base = guid;
   iov[1].iov_len = kGuidSize + 1;
   iov[2].iov_base = crash_url;
   iov[2].iov_len = kMaxActiveURLSize + 1;
   iov[3].iov_base = distro;
   iov[3].iov_len = kDistroSize + 1;
+  iov[4].iov_base = &b_addr;
+  iov[4].iov_len = sizeof(b_addr);
+  iov[5].iov_base = &fds[0];
+  iov[5].iov_len = sizeof(fds[0]);
 
   msg.msg_iov = iov;
-  msg.msg_iovlen = 4;
+  msg.msg_iovlen = 6;
   char cmsg[kControlMsgSize];
   my_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];
 
   HANDLE_EINTR(sys_sendmsg(fd, &msg, 0));
   sys_close(fds[1]);
 
-  char b;
   HANDLE_EINTR(sys_read(fds[0], &b, 1));
 
   return true;
 }
 
 void EnableNonBrowserCrashDumping() {
   const int fd = Singleton<base::GlobalDescriptors>()->Get(kCrashDumpSignal);
   is_crash_reporter_enabled = true;
   // We deliberately leak this object.
   google_breakpad::ExceptionHandler* handler =
@@ skipping 39 matching lines @@
   struct timeval tv;
   if (!gettimeofday(&tv, NULL))
     uptime = timeval_to_ms(&tv);
   else
     uptime = 0;
 }
 
 bool IsCrashReporterEnabled() {
   return is_crash_reporter_enabled;
 }