Linux: Use upstream google-breakpad instead of our fork....

breakpad/linux/minidump_writer.cc

-// 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.
-
-// This code writes out minidump files:
-//   http://msdn.microsoft.com/en-us/library/ms680378(VS.85,loband).aspx
-//
-// Minidumps are a Microsoft format which Breakpad uses for recording crash
-// dumps. This code has to run in a compromised environment (the address space
-// may have received SIGSEGV), thus the following rules apply:
-//   * You may not enter the dynamic linker. This means that we cannot call
-//     any symbols in a shared library (inc libc). Because of this we replace
-//     libc functions in linux_libc_support.h.
-//   * You may not call syscalls via the libc wrappers. This rule is a subset
-//     of the first rule but it bears repeating. We have direct wrappers
-//     around the system calls in linux_syscall_support.h.
-//   * You may not malloc. There's an alternative allocator in memory.h and
-//     a canonical instance in the LinuxDumper object. We use the placement
-//     new form to allocate objects and we don't delete them.
-
-#include "breakpad/linux/minidump_writer.h"
-#include "client/minidump_file_writer-inl.h"
-
-#include <errno.h>
-#include <fcntl.h>
-#include <stdio.h>
-#include <unistd.h>
-#include <sys/ucontext.h>
-#include <sys/user.h>
-#include <sys/utsname.h>
-
-#include "client/minidump_file_writer.h"
-#include "google_breakpad/common/minidump_format.h"
-#include "google_breakpad/common/minidump_cpu_amd64.h"
-#include "google_breakpad/common/minidump_cpu_x86.h"
-
-#include "breakpad/linux/exception_handler.h"
-#include "breakpad/linux/line_reader.h"
-#include "breakpad/linux/linux_dumper.h"
-#include "breakpad/linux/linux_libc_support.h"
-#include "breakpad/linux/linux_syscall_support.h"
-#include "breakpad/linux/minidump_format_linux.h"
-
-// Minidump defines register structures which are different from the raw
-// structures which we get from the kernel. These are platform specific
-// functions to juggle the ucontext and user structures into minidump format.
-#if defined(__i386)
-typedef MDRawContextX86 RawContextCPU;
-
-// Write a uint16_t to memory
-//   out: memory location to write to
-//   v: value to write.
-static void U16(void* out, uint16_t v) {
-  memcpy(out, &v, sizeof(v));
-}
-
-// Write a uint32_t to memory
-//   out: memory location to write to
-//   v: value to write.
-static void U32(void* out, uint32_t v) {
-  memcpy(out, &v, sizeof(v));
-}
-
-// Juggle an x86 user_(fp|fpx|)regs_struct into minidump format
-//   out: the minidump structure
-//   info: the collection of register structures.
-static void CPUFillFromThreadInfo(MDRawContextX86 *out,
-                                  const google_breakpad::ThreadInfo &info) {
-  out->context_flags = MD_CONTEXT_X86_ALL;
-
-  out->dr0 = info.dregs[0];
-  out->dr1 = info.dregs[1];
-  out->dr2 = info.dregs[2];
-  out->dr3 = info.dregs[3];
-  // 4 and 5 deliberatly omitted because they aren't included in the minidump
-  // format.
-  out->dr6 = info.dregs[6];
-  out->dr7 = info.dregs[7];
-
-  out->gs = info.regs.xgs;
-  out->fs = info.regs.xfs;
-  out->es = info.regs.xes;
-  out->ds = info.regs.xds;
-
-  out->edi = info.regs.edi;
-  out->esi = info.regs.esi;
-  out->ebx = info.regs.ebx;
-  out->edx = info.regs.edx;
-  out->ecx = info.regs.ecx;
-  out->eax = info.regs.eax;
-
-  out->ebp = info.regs.ebp;
-  out->eip = info.regs.eip;
-  out->cs = info.regs.xcs;
-  out->eflags = info.regs.eflags;
-  out->esp = info.regs.esp;
-  out->ss = info.regs.xss;
-
-  out->float_save.control_word = info.fpregs.cwd;
-  out->float_save.status_word = info.fpregs.swd;
-  out->float_save.tag_word = info.fpregs.twd;
-  out->float_save.error_offset = info.fpregs.fip;
-  out->float_save.error_selector = info.fpregs.fcs;
-  out->float_save.data_offset = info.fpregs.foo;
-  out->float_save.data_selector = info.fpregs.fos;
-
-  // 8 registers * 10 bytes per register.
-  memcpy(out->float_save.register_area, info.fpregs.st_space, 10 * 8);
-
-  // This matches the Intel fpsave format.
-  U16(out->extended_registers + 0, info.fpregs.cwd);
-  U16(out->extended_registers + 2, info.fpregs.swd);
-  U16(out->extended_registers + 4, info.fpregs.twd);
-  U16(out->extended_registers + 6, info.fpxregs.fop);
-  U32(out->extended_registers + 8, info.fpxregs.fip);
-  U16(out->extended_registers + 12, info.fpxregs.fcs);
-  U32(out->extended_registers + 16, info.fpregs.foo);
-  U16(out->extended_registers + 20, info.fpregs.fos);
-  U32(out->extended_registers + 24, info.fpxregs.mxcsr);
-
-  memcpy(out->extended_registers + 32, &info.fpxregs.st_space, 128);
-  memcpy(out->extended_registers + 160, &info.fpxregs.xmm_space, 128);
-}
-
-// Juggle an x86 ucontext into minidump format
-//   out: the minidump structure
-//   info: the collection of register structures.
-static void CPUFillFromUContext(MDRawContextX86 *out, const ucontext *uc,
-                                const struct _libc_fpstate* fp) {
-  const greg_t* regs = uc->uc_mcontext.gregs;
-
-  out->context_flags = MD_CONTEXT_X86_FULL |
-                       MD_CONTEXT_X86_FLOATING_POINT;
-
-  out->gs = regs[REG_GS];
-  out->fs = regs[REG_FS];
-  out->es = regs[REG_ES];
-  out->ds = regs[REG_DS];
-
-  out->edi = regs[REG_EDI];
-  out->esi = regs[REG_ESI];
-  out->ebx = regs[REG_EBX];
-  out->edx = regs[REG_EDX];
-  out->ecx = regs[REG_ECX];
-  out->eax = regs[REG_EAX];
-
-  out->ebp = regs[REG_EBP];
-  out->eip = regs[REG_EIP];
-  out->cs = regs[REG_CS];
-  out->eflags = regs[REG_EFL];
-  out->esp = regs[REG_UESP];
-  out->ss = regs[REG_SS];
-
-  out->float_save.control_word = fp->cw;
-  out->float_save.status_word = fp->sw;
-  out->float_save.tag_word = fp->tag;
-  out->float_save.error_offset = fp->ipoff;
-  out->float_save.error_selector = fp->cssel;
-  out->float_save.data_offset = fp->dataoff;
-  out->float_save.data_selector = fp->datasel;
-
-  // 8 registers * 10 bytes per register.
-  memcpy(out->float_save.register_area, fp->_st, 10 * 8);
-}
-
-#elif defined(__x86_64)
-typedef MDRawContextAMD64 RawContextCPU;
-
-static void CPUFillFromThreadInfo(MDRawContextAMD64 *out,
-                                  const google_breakpad::ThreadInfo &info) {
-  out->context_flags = MD_CONTEXT_AMD64_FULL |
-                       MD_CONTEXT_AMD64_SEGMENTS;
-
-  out->cs = info.regs.cs;
-
-  out->ds = info.regs.ds;
-  out->es = info.regs.es;
-  out->fs = info.regs.fs;
-  out->gs = info.regs.gs;
-
-  out->ss = info.regs.ss;
-  out->eflags = info.regs.eflags;
-
-  out->dr0 = info.dregs[0];
-  out->dr1 = info.dregs[1];
-  out->dr2 = info.dregs[2];
-  out->dr3 = info.dregs[3];
-  // 4 and 5 deliberatly omitted because they aren't included in the minidump
-  // format.
-  out->dr6 = info.dregs[6];
-  out->dr7 = info.dregs[7];
-
-  out->rax = info.regs.rax;
-  out->rcx = info.regs.rcx;
-  out->rdx = info.regs.rdx;
-  out->rbx = info.regs.rbx;
-
-  out->rsp = info.regs.rsp;
-
-  out->rbp = info.regs.rbp;
-  out->rsi = info.regs.rsi;
-  out->rdi = info.regs.rdi;
-  out->r8 = info.regs.r8;
-  out->r9 = info.regs.r9;
-  out->r10 = info.regs.r10;
-  out->r11 = info.regs.r11;
-  out->r12 = info.regs.r12;
-  out->r13 = info.regs.r13;
-  out->r14 = info.regs.r14;
-  out->r15 = info.regs.r15;
-
-  out->rip = info.regs.rip;
-
-  out->flt_save.control_word = info.fpregs.cwd;
-  out->flt_save.status_word = info.fpregs.swd;
-  out->flt_save.tag_word = info.fpregs.ftw;
-  out->flt_save.error_opcode = info.fpregs.fop;
-  out->flt_save.error_offset = info.fpregs.rip;
-  out->flt_save.error_selector = 0; // We don't have this.
-  out->flt_save.data_offset = info.fpregs.rdp;
-  out->flt_save.data_selector = 0;  // We don't have this.
-  out->flt_save.mx_csr = info.fpregs.mxcsr;
-  out->flt_save.mx_csr_mask = info.fpregs.mxcr_mask;
-  memcpy(&out->flt_save.float_registers, &info.fpregs.st_space, 8 * 16);
-  memcpy(&out->flt_save.xmm_registers, &info.fpregs.xmm_space, 16 * 16);
-}
-
-static void CPUFillFromUContext(MDRawContextAMD64 *out, const ucontext *uc,
-                                const struct _libc_fpstate* fpregs) {
-  const greg_t* regs = uc->uc_mcontext.gregs;
-
-  out->context_flags = MD_CONTEXT_AMD64_FULL;
-
-  out->cs = regs[REG_CSGSFS] & 0xffff;
-
-  out->fs = (regs[REG_CSGSFS] >> 32) & 0xffff;
-  out->gs = (regs[REG_CSGSFS] >> 16) & 0xffff;
-
-  out->eflags = regs[REG_EFL];
-
-  out->rax = regs[REG_RAX];
-  out->rcx = regs[REG_RCX];
-  out->rdx = regs[REG_RDX];
-  out->rbx = regs[REG_RBX];
-
-  out->rsp = regs[REG_RSP];
-  out->rbp = regs[REG_RBP];
-  out->rsi = regs[REG_RSI];
-  out->rdi = regs[REG_RDI];
-  out->r8 = regs[REG_R8];
-  out->r9 = regs[REG_R9];
-  out->r10 = regs[REG_R10];
-  out->r11 = regs[REG_R11];
-  out->r12 = regs[REG_R12];
-  out->r13 = regs[REG_R13];
-  out->r14 = regs[REG_R14];
-  out->r15 = regs[REG_R15];
-
-  out->rip = regs[REG_RIP];
-
-  out->flt_save.control_word = fpregs->cwd;
-  out->flt_save.status_word = fpregs->swd;
-  out->flt_save.tag_word = fpregs->ftw;
-  out->flt_save.error_opcode = fpregs->fop;
-  out->flt_save.error_offset = fpregs->rip;
-  out->flt_save.data_offset = fpregs->rdp;
-  out->flt_save.error_selector = 0; // We don't have this.
-  out->flt_save.data_selector = 0;  // We don't have this.
-  out->flt_save.mx_csr = fpregs->mxcsr;
-  out->flt_save.mx_csr_mask = fpregs->mxcr_mask;
-  memcpy(&out->flt_save.float_registers, &fpregs->_st, 8 * 16);
-  memcpy(&out->flt_save.xmm_registers, &fpregs->_xmm, 16 * 16);
-}
-
-#else
-#error "This code has not been ported to your platform yet."
-#endif
-
-namespace google_breakpad {
-
-class MinidumpWriter {
- public:
-  MinidumpWriter(const char* filename,
-                 pid_t crashing_pid,
-                 const ExceptionHandler::CrashContext* context)
-      : filename_(filename),
-        siginfo_(&context->siginfo),
-        ucontext_(&context->context),
-        float_state_(&context->float_state),
-        crashing_tid_(context->tid),
-        dumper_(crashing_pid) {
-  }
-
-  bool Init() {
-    return dumper_.Init() && minidump_writer_.Open(filename_) &&
-           dumper_.ThreadsSuspend();
-  }
-
-  ~MinidumpWriter() {
-    minidump_writer_.Close();
-    dumper_.ThreadsResume();
-  }
-
-  bool Dump() {
-    // A minidump file contains a number of tagged streams. This is the number
-    // of stream which we write.
-    static const unsigned kNumWriters = 11;
-
-    TypedMDRVA<MDRawHeader> header(&minidump_writer_);
-    TypedMDRVA<MDRawDirectory> dir(&minidump_writer_);
-    if (!header.Allocate())
-      return false;
-    if (!dir.AllocateArray(kNumWriters))
-      return false;
-    memset(header.get(), 0, sizeof(MDRawHeader));
-
-    header.get()->signature = MD_HEADER_SIGNATURE;
-    header.get()->version = MD_HEADER_VERSION;
-    header.get()->time_date_stamp = time(NULL);
-    header.get()->stream_count = kNumWriters;
-    header.get()->stream_directory_rva = dir.position();
-
-    unsigned dir_index = 0;
-    MDRawDirectory dirent;
-
-    if (!WriteThreadListStream(&dirent))
-      return false;
-    dir.CopyIndex(dir_index++, &dirent);
-
-    if (!WriteMappings(&dirent))
-      return false;
-    dir.CopyIndex(dir_index++, &dirent);
-
-    if (!WriteExceptionStream(&dirent))
-      return false;
-    dir.CopyIndex(dir_index++, &dirent);
-
-    if (!WriteSystemInfoStream(&dirent))
-      return false;
-    dir.CopyIndex(dir_index++, &dirent);
-
-    dirent.stream_type = MD_LINUX_CPU_INFO;
-    if (!WriteFile(&dirent.location, "/proc/cpuinfo"))
-      NullifyDirectoryEntry(&dirent);
-    dir.CopyIndex(dir_index++, &dirent);
-
-    dirent.stream_type = MD_LINUX_PROC_STATUS;
-    if (!WriteProcFile(&dirent.location, crashing_tid_, "status"))
-      NullifyDirectoryEntry(&dirent);
-    dir.CopyIndex(dir_index++, &dirent);
-
-    dirent.stream_type = MD_LINUX_LSB_RELEASE;
-    if (!WriteFile(&dirent.location, "/etc/lsb-release"))
-      NullifyDirectoryEntry(&dirent);
-    dir.CopyIndex(dir_index++, &dirent);
-
-    dirent.stream_type = MD_LINUX_CMD_LINE;
-    if (!WriteProcFile(&dirent.location, crashing_tid_, "cmdline"))
-      NullifyDirectoryEntry(&dirent);
-    dir.CopyIndex(dir_index++, &dirent);
-
-    dirent.stream_type = MD_LINUX_ENVIRON;
-    if (!WriteProcFile(&dirent.location, crashing_tid_, "environ"))
-      NullifyDirectoryEntry(&dirent);
-    dir.CopyIndex(dir_index++, &dirent);
-
-    dirent.stream_type = MD_LINUX_AUXV;
-    if (!WriteProcFile(&dirent.location, crashing_tid_, "auxv"))
-      NullifyDirectoryEntry(&dirent);
-    dir.CopyIndex(dir_index++, &dirent);
-
-    dirent.stream_type = MD_LINUX_AUXV;
-    if (!WriteProcFile(&dirent.location, crashing_tid_, "maps"))
-      NullifyDirectoryEntry(&dirent);
-    dir.CopyIndex(dir_index++, &dirent);
-
-    // If you add more directory entries, don't forget to update kNumWriters,
-    // above.
-
-    dumper_.ThreadsResume();
-    return true;
-  }
-
-  // Write information about the threads.
-  bool WriteThreadListStream(MDRawDirectory* dirent) {
-    const unsigned num_threads = dumper_.threads().size();
-
-    TypedMDRVA<uint32_t> list(&minidump_writer_);
-    if (!list.AllocateObjectAndArray(num_threads, sizeof(MDRawThread)))
-      return false;
-
-    dirent->stream_type = MD_THREAD_LIST_STREAM;
-    dirent->location = list.location();
-
-    *list.get() = num_threads;
-
-    for (unsigned i = 0; i < num_threads; ++i) {
-      MDRawThread thread;
-      my_memset(&thread, 0, sizeof(thread));
-      thread.thread_id = dumper_.threads()[i];
-      // We have a different source of information for the crashing thread. If
-      // we used the actual state of the thread we would find it running in the
-      // signal handler with the alternative stack, which would be deeply
-      // unhelpful.
-      if (thread.thread_id == crashing_tid_) {
-        const void* stack;
-        size_t stack_len;
-        if (!dumper_.GetStackInfo(&stack, &stack_len, GetStackPointer()))
-          return false;
-        UntypedMDRVA memory(&minidump_writer_);
-        if (!memory.Allocate(stack_len))
-          return false;
-        uint8_t* stack_copy = (uint8_t*) dumper_.allocator()->Alloc(stack_len);
-        dumper_.CopyFromProcess(stack_copy, thread.thread_id, stack, stack_len);
-        memory.Copy(stack_copy, stack_len);
-        thread.stack.start_of_memory_range = (uintptr_t) (stack);
-        thread.stack.memory = memory.location();
-        TypedMDRVA<RawContextCPU> cpu(&minidump_writer_);
-        if (!cpu.Allocate())
-          return false;
-        my_memset(cpu.get(), 0, sizeof(RawContextCPU));
-        CPUFillFromUContext(cpu.get(), ucontext_, float_state_);
-        thread.thread_context = cpu.location();
-        crashing_thread_context_ = cpu.location();
-      } else {
-        ThreadInfo info;
-        if (!dumper_.ThreadInfoGet(dumper_.threads()[i], &info))
-          return false;
-        UntypedMDRVA memory(&minidump_writer_);
-        if (!memory.Allocate(info.stack_len))
-          return false;
-        uint8_t* stack_copy =
-            (uint8_t*) dumper_.allocator()->Alloc(info.stack_len);
-        dumper_.CopyFromProcess(stack_copy, thread.thread_id, info.stack,
-                                info.stack_len);
-        memory.Copy(stack_copy, info.stack_len);
-        thread.stack.start_of_memory_range = (uintptr_t)(info.stack);
-        thread.stack.memory = memory.location();
-        TypedMDRVA<RawContextCPU> cpu(&minidump_writer_);
-        if (!cpu.Allocate())
-          return false;
-        my_memset(cpu.get(), 0, sizeof(RawContextCPU));
-        CPUFillFromThreadInfo(cpu.get(), info);
-        thread.thread_context = cpu.location();
-      }
-
-      list.CopyIndexAfterObject(i, &thread, sizeof(thread));
-    }
-
-    return true;
-  }
-
-  static bool ShouldIncludeMapping(const MappingInfo& mapping) {
-    if (mapping.name[0] == 0 || // we only want modules with filenames.
-        mapping.offset || // we only want to include one mapping per shared lib.
-        mapping.size < 4096) {  // too small to get a signature for.
-      return false;
-    }
-
-    return true;
-  }
-
-  // Write information about the mappings in effect. Because we are using the
-  // minidump format, the information about the mappings is pretty limited.
-  // Because of this, we also include the full, unparsed, /proc/$x/maps file in
-  // another stream in the file.
-  bool WriteMappings(MDRawDirectory* dirent) {
-    const unsigned num_mappings = dumper_.mappings().size();
-    unsigned num_output_mappings = 0;
-
-    for (unsigned i = 0; i < dumper_.mappings().size(); ++i) {
-      const MappingInfo& mapping = *dumper_.mappings()[i];
-      if (ShouldIncludeMapping(mapping))
-        num_output_mappings++;
-    }
-
-    TypedMDRVA<uint32_t> list(&minidump_writer_);
-    if (!list.AllocateObjectAndArray(num_output_mappings, MD_MODULE_SIZE))
-      return false;
-
-    dirent->stream_type = MD_MODULE_LIST_STREAM;
-    dirent->location = list.location();
-    *list.get() = num_output_mappings;
-
-    for (unsigned i = 0, j = 0; i < num_mappings; ++i) {
-      const MappingInfo& mapping = *dumper_.mappings()[i];
-      if (!ShouldIncludeMapping(mapping))
-        continue;
-
-      MDRawModule mod;
-      my_memset(&mod, 0, MD_MODULE_SIZE);
-      mod.base_of_image = mapping.start_addr;
-      mod.size_of_image = mapping.size;
-      const size_t filepath_len = my_strlen(mapping.name);
-
-      // Figure out file name from path
-      const char* filename_ptr = mapping.name + filepath_len - 1;
-      while (filename_ptr >= mapping.name) {
-        if (*filename_ptr == '/')
-          break;
-        filename_ptr--;
-      }
-      filename_ptr++;
-      const size_t filename_len = mapping.name + filepath_len - filename_ptr;
-
-      uint8_t cv_buf[MDCVInfoPDB70_minsize + NAME_MAX];
-      uint8_t* cv_ptr = cv_buf;
-      UntypedMDRVA cv(&minidump_writer_);
-      if (!cv.Allocate(MDCVInfoPDB70_minsize + filename_len + 1))
-        return false;
-
-      const uint32_t cv_signature = MD_CVINFOPDB70_SIGNATURE;
-      memcpy(cv_ptr, &cv_signature, sizeof(cv_signature));
-      cv_ptr += sizeof(cv_signature);
-
-      {
-        // We XOR the first page of the file to get a signature for it.
-        uint8_t xor_buf[sizeof(MDGUID)];
-        size_t done = 0;
-        uint8_t* signature = cv_ptr;
-        cv_ptr += sizeof(xor_buf);
-
-        my_memset(signature, 0, sizeof(xor_buf));
-        while (done < 4096) {
-          dumper_.CopyFromProcess(xor_buf, crashing_tid_,
-                                  (void *) (mod.base_of_image + done),
-                                  sizeof(xor_buf));
-          for (unsigned i = 0; i < sizeof(xor_buf); ++i)
-            signature[i] ^= xor_buf[i];
-          done += sizeof(xor_buf);
-        }
-        my_memset(cv_ptr, 0, sizeof(uint32_t));  // Set age to 0 on Linux.
-        cv_ptr += sizeof(uint32_t);
-      }
-
-      // Write pdb_file_name
-      memcpy(cv_ptr, filename_ptr, filename_len + 1);
-      cv.Copy(cv_buf, MDCVInfoPDB70_minsize + filename_len + 1);
-
-      mod.cv_record = cv.location();
-
-      MDLocationDescriptor ld;
-      if (!minidump_writer_.WriteString(mapping.name, filepath_len, &ld))
-        return false;
-      mod.module_name_rva = ld.rva;
-
-      list.CopyIndexAfterObject(j++, &mod, MD_MODULE_SIZE);
-    }
-
-    return true;
-  }
-
-  bool WriteExceptionStream(MDRawDirectory* dirent) {
-    TypedMDRVA<MDRawExceptionStream> exc(&minidump_writer_);
-    if (!exc.Allocate())
-      return false;
-    my_memset(exc.get(), 0, sizeof(MDRawExceptionStream));
-
-    dirent->stream_type = MD_EXCEPTION_STREAM;
-    dirent->location = exc.location();
-
-    exc.get()->thread_id = crashing_tid_;
-    exc.get()->exception_record.exception_code = siginfo_->si_signo;
-    exc.get()->exception_record.exception_address =
-        (uintptr_t) siginfo_->si_addr;
-    exc.get()->thread_context = crashing_thread_context_;
-
-    return true;
-  }
-
-  bool WriteSystemInfoStream(MDRawDirectory* dirent) {
-    TypedMDRVA<MDRawSystemInfo> si(&minidump_writer_);
-    if (!si.Allocate())
-      return false;
-    my_memset(si.get(), 0, sizeof(MDRawSystemInfo));
-
-    dirent->stream_type = MD_SYSTEM_INFO_STREAM;
-    dirent->location = si.location();
-
-    WriteCPUInformation(si.get());
-    WriteOSInformation(si.get());
-
-    return true;
-  }
-
- private:
-#if defined(__i386)
-  uintptr_t GetStackPointer() {
-    return ucontext_->uc_mcontext.gregs[REG_ESP];
-  }
-#elif defined(__x86_64)
-  uintptr_t GetStackPointer() {
-    return ucontext_->uc_mcontext.gregs[REG_RSP];
-  }
-#else
-#error "This code has not been ported to your platform yet."
-#endif
-
-  void NullifyDirectoryEntry(MDRawDirectory* dirent) {
-    dirent->stream_type = 0;
-    dirent->location.data_size = 0;
-    dirent->location.rva = 0;
-  }
-
-  bool WriteCPUInformation(MDRawSystemInfo* sys_info) {
-    char vendor_id[sizeof(sys_info->cpu.x86_cpu_info.vendor_id) + 1] = {0};
-    static const char vendor_id_name[] = "vendor_id";
-    static const size_t vendor_id_name_length = sizeof(vendor_id_name) - 1;
-
-    struct CpuInfoEntry {
-      const char* info_name;
-      int value;
-      bool found;
-    } cpu_info_table[] = {
-      { "processor", -1, false },
-      { "model", 0, false },
-      { "stepping",  0, false },
-      { "cpu family", 0, false },
-    };
-
-    // processor_architecture should always be set, do this first
-    sys_info->processor_architecture =
-#if defined(__i386)
-        MD_CPU_ARCHITECTURE_X86;
-#elif defined(__x86_64)
-        MD_CPU_ARCHITECTURE_AMD64;
-#else
-#error "Unknown CPU arch"
-#endif
-
-    const int fd = sys_open("/proc/cpuinfo", O_RDONLY, 0);
-    if (fd < 0)
-      return false;
-
-    {
-      PageAllocator allocator;
-      LineReader* const line_reader = new(allocator) LineReader(fd);
-      const char* line;
-      unsigned line_len;
-      while (line_reader->GetNextLine(&line, &line_len)) {
-        for (size_t i = 0;
-             i < sizeof(cpu_info_table) / sizeof(cpu_info_table[0]);
-             i++) {
-          CpuInfoEntry* entry = &cpu_info_table[i];
-          if (entry->found)
-            continue;
-          if (!strncmp(line, entry->info_name, strlen(entry->info_name))) {
-            const char* value = strchr(line, ':');
-            if (!value)
-              continue;
-
-            // the above strncmp only matches the prefix, it might be the wrong
-            // line. i.e. we matched "model name" instead of "model".
-            // check and make sure there is only spaces between the prefix and
-            // the colon.
-            const char* space_ptr = line + strlen(entry->info_name);
-            for (; space_ptr < value; space_ptr++) {
-              if (!isspace(*space_ptr)) {
-                break;
-              }
-            }
-            if (space_ptr != value)
-              continue;
-
-            sscanf(++value, " %d", &(entry->value));
-            entry->found = true;
-          }
-        }
-
-        // special case for vendor_id
-        if (!strncmp(line, vendor_id_name, vendor_id_name_length)) {
-          const char* value = strchr(line, ':');
-          if (!value)
-            goto popline;
-
-          // skip ':" and all the spaces that follows
-          do {
-            value++;
-          } while (isspace(*value));
-
-          if (*value) {
-            size_t length = strlen(value);
-            if (length == 0)
-              goto popline;
-            // we don't want the trailing newline
-            if (value[length - 1] == '\n')
-              length--;
-            // ensure we have space for the value
-            if (length < sizeof(vendor_id))
-              strncpy(vendor_id, value, length);
-          }
-        }
-
-popline:
-        line_reader->PopLine(line_len);
-      }
-      sys_close(fd);
-    }
-
-    // make sure we got everything we wanted
-    for (size_t i = 0;
-         i < sizeof(cpu_info_table) / sizeof(cpu_info_table[0]);
-         i++) {
-      if (!cpu_info_table[i].found) {
-        return false;
-      }
-    }
-    // /proc/cpuinfo contains cpu id, change it into number by adding one.
-    cpu_info_table[0].value++;
-
-    sys_info->number_of_processors = cpu_info_table[0].value;
-    sys_info->processor_level      = cpu_info_table[3].value;
-    sys_info->processor_revision   = cpu_info_table[1].value << 8 |
-                                     cpu_info_table[2].value;
-
-    if (vendor_id[0] != '\0') {
-      memcpy(sys_info->cpu.x86_cpu_info.vendor_id, vendor_id,
-             sizeof(sys_info->cpu.x86_cpu_info.vendor_id));
-    }
-    return true;
-  }
-
-  bool WriteFile(MDLocationDescriptor* result, const char* filename) {
-    const int fd = sys_open(filename, O_RDONLY, 0);
-    if (fd < 0)
-      return false;
-
-    // We can't stat the files because several of the files that we want to
-    // read are kernel seqfiles, which always have a length of zero. So we have
-    // to read as much as we can into a buffer.
-    static const unsigned kMaxFileSize = 1024;
-    uint8_t* data = (uint8_t*) dumper_.allocator()->Alloc(kMaxFileSize);
-
-    size_t done = 0;
-    while (done < kMaxFileSize) {
-      ssize_t r;
-      do {
-        r = sys_read(fd, data + done, kMaxFileSize - done);
-      } while (r == -1 && errno == EINTR);
-
-      if (r < 1)
-        break;
-      done += r;
-    }
-    sys_close(fd);
-
-    if (!done)
-      return false;
-
-    UntypedMDRVA memory(&minidump_writer_);
-    if (!memory.Allocate(done))
-      return false;
-    memory.Copy(data, done);
-    *result = memory.location();
-    return true;
-  }
-
-  bool WriteOSInformation(MDRawSystemInfo* sys_info) {
-    sys_info->platform_id = MD_OS_LINUX;
-
-    struct utsname uts;
-    if (uname(&uts))
-      return false;
-
-    static const size_t buf_len = 512;
-    char buf[buf_len] = {0};
-    size_t space_left = buf_len - 1;
-    const char* info_table[] = {
-      uts.sysname,
-      uts.release,
-      uts.version,
-      uts.machine,
-      NULL
-    };
-    bool first_item = true;
-    for (const char** cur_info = info_table; *cur_info; cur_info++) {
-      static const char* separator = " ";
-      size_t separator_len = strlen(separator);
-      size_t info_len = strlen(*cur_info);
-      if (info_len == 0)
-        continue;
-
-      if (space_left < info_len + (first_item ? 0 : separator_len))
-        break;
-
-      if (!first_item) {
-        strcat(buf, separator);
-        space_left -= separator_len;
-      }
-
-      first_item = false;
-      strcat(buf, *cur_info);
-      space_left -= info_len;
-    }
-
-    MDLocationDescriptor location;
-    if (!minidump_writer_.WriteString(buf, 0, &location))
-      return false;
-    sys_info->csd_version_rva = location.rva;
-
-    return true;
-  }
-
-  bool WriteProcFile(MDLocationDescriptor* result, pid_t pid,
-                     const char* filename) {
-    char buf[80];
-    memcpy(buf, "/proc/", 6);
-    const unsigned pid_len = my_int_len(pid);
-    my_itos(buf + 6, pid, pid_len);
-    buf[6 + pid_len] = '/';
-    memcpy(buf + 6 + pid_len + 1, filename, my_strlen(filename) + 1);
-    return WriteFile(result, buf);
-  }
-
-  const char* const filename_;  // output filename
-  const siginfo_t* const siginfo_;  // from the signal handler (see sigaction)
-  const struct ucontext* const ucontext_;  // also from the signal handler
-  const struct _libc_fpstate* const float_state_;  // ditto
-  const pid_t crashing_tid_;  // the process which actually crashed
-  LinuxDumper dumper_;
-  MinidumpFileWriter minidump_writer_;
-  MDLocationDescriptor crashing_thread_context_;
-};
-
-bool WriteMinidump(const char* filename, pid_t crashing_process,
-                   const void* blob, size_t blob_size) {
-  if (blob_size != sizeof(ExceptionHandler::CrashContext))
-    return false;
-  const ExceptionHandler::CrashContext* context =
-      reinterpret_cast<const ExceptionHandler::CrashContext*>(blob);
-  MinidumpWriter writer(filename, crashing_process, context);
-  if (!writer.Init())
-    return false;
-  return writer.Dump();
-}
-
-}  // namespace google_breakpad