crash_dump: fork a copy of the target's address space.

Reduce the amount of time that a process remains paused by pausing its
threads, fetching their registers, and then performing unwinding on a
copy of its address space. This also works around a kernel change
that's in 4.9 that prevents ptrace from reading memory of processes
that we don't have immediate permissions to ptrace (even if we
previously ptraced them).

Bug: http://b/62112103
Bug: http://b/63989615
Test: treehugger
Change-Id: I7b9cc5dd8f54a354bc61f1bda0d2b7a8a55733c4

1 files changed, 0 insertions, 63 deletions

diff --git a/debuggerd/libdebuggerd/x86/machine.cpp b/debuggerd/libdebuggerd/x86/machine.cpp
deleted file mode 100644
index 09a64cdb6..000000000
--- a/debuggerd/libdebuggerd/x86/machine.cpp
+++ /dev/null
@@ -1,63 +0,0 @@
-/*
- * Copyright 2006, The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#define LOG_TAG "DEBUG"
-
-#include "libdebuggerd/machine.h"
-
-#include <errno.h>
-#include <stdint.h>
-#include <string.h>
-#include <sys/ptrace.h>
-
-#include <backtrace/Backtrace.h>
-#include <log/log.h>
-
-#include "libdebuggerd/utility.h"
-
-void dump_memory_and_code(log_t* log, Backtrace* backtrace) {
-  struct pt_regs r;
-  if (ptrace(PTRACE_GETREGS, backtrace->Tid(), 0, &r) == -1) {
-    ALOGE("cannot get registers: %s\n", strerror(errno));
-    return;
-  }
-
-  dump_memory(log, backtrace, static_cast<uintptr_t>(r.eax), "memory near eax:");
-  dump_memory(log, backtrace, static_cast<uintptr_t>(r.ebx), "memory near ebx:");
-  dump_memory(log, backtrace, static_cast<uintptr_t>(r.ecx), "memory near ecx:");
-  dump_memory(log, backtrace, static_cast<uintptr_t>(r.edx), "memory near edx:");
-  dump_memory(log, backtrace, static_cast<uintptr_t>(r.esi), "memory near esi:");
-  dump_memory(log, backtrace, static_cast<uintptr_t>(r.edi), "memory near edi:");
-
-  dump_memory(log, backtrace, static_cast<uintptr_t>(r.eip), "code around eip:");
-}
-
-void dump_registers(log_t* log, pid_t tid) {
-  struct pt_regs r;
-  if (ptrace(PTRACE_GETREGS, tid, 0, &r) == -1) {
-    ALOGE("cannot get registers: %s\n", strerror(errno));
-    return;
-  }
-
-  _LOG(log, logtype::REGISTERS, "    eax %08lx  ebx %08lx  ecx %08lx  edx %08lx\n",
-       r.eax, r.ebx, r.ecx, r.edx);
-  _LOG(log, logtype::REGISTERS, "    esi %08lx  edi %08lx\n",
-       r.esi, r.edi);
-  _LOG(log, logtype::REGISTERS, "    xcs %08x  xds %08x  xes %08x  xfs %08x  xss %08x\n",
-       r.xcs, r.xds, r.xes, r.xfs, r.xss);
-  _LOG(log, logtype::REGISTERS, "    eip %08lx  ebp %08lx  esp %08lx  flags %08lx\n",
-       r.eip, r.ebp, r.esp, r.eflags);
-}