Update from https://crrev.com/328418

sandbox/linux/seccomp-bpf-helpers/sigsys_handlers.cc

 // Copyright (c) 2013 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.
 
 // Note: any code in this file MUST be async-signal safe.
 
 #include "sandbox/linux/seccomp-bpf-helpers/sigsys_handlers.h"
 
 #include <sys/syscall.h>
 #include <unistd.h>
@@ skipping 170 matching lines @@
   *addr = '\0';
   for (;;)
     _exit(1);
 }
 
 intptr_t SIGSYSKillFailure(const struct arch_seccomp_data& args,
                            void* /* aux */) {
    static const char kSeccompKillError[] =
       __FILE__":**CRASHING**:" SECCOMP_MESSAGE_KILL_CONTENT "\n";
   WriteToStdErr(kSeccompKillError, sizeof(kSeccompKillError) - 1);
-  // Make "request" volatile so that we can see it on the stack in a minidump.
-  volatile uint64_t pid = args.args[0];
-  volatile char* addr = reinterpret_cast<volatile char*>(pid & 0xFFF);
-  *addr = '\0';
-  // Hit the NULL page if this fails.
-  addr = reinterpret_cast<volatile char*>(pid & 0xFFF);
+  // Make "pid" volatile so that we can see it on the stack in a minidump.
+  volatile uint64_t my_pid = sys_getpid();
+  volatile char* addr = reinterpret_cast<volatile char*>(my_pid & 0xFFF);
   *addr = '\0';
   for (;;)
     _exit(1);
 }
 
 intptr_t SIGSYSFutexFailure(const struct arch_seccomp_data& args,
                             void* /* aux */) {
   static const char kSeccompFutexError[] =
       __FILE__ ":**CRASHING**:" SECCOMP_MESSAGE_FUTEX_CONTENT "\n";
   WriteToStdErr(kSeccompFutexError, sizeof(kSeccompFutexError) - 1);
@@ skipping 84 matching lines @@
 
 const char* GetKillErrorMessageContentForTests() {
   return SECCOMP_MESSAGE_KILL_CONTENT;
 }
 
 const char* GetFutexErrorMessageContentForTests() {
   return SECCOMP_MESSAGE_FUTEX_CONTENT;
 }
 
 }  // namespace sandbox.