Adding upstream version 110.0.1.upstream/110.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

6 files changed, 699 insertions, 0 deletions

diff --git a/security/sandbox/linux/reporter/SandboxReporter.cpp b/security/sandbox/linux/reporter/SandboxReporter.cpp
new file mode 100644
index 0000000000..a7c71cd5c9
--- /dev/null
+++ b/security/sandbox/linux/reporter/SandboxReporter.cpp
@@ -0,0 +1,299 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "SandboxReporter.h"
+#include "SandboxLogging.h"
+
+#include <algorithm>
+#include <errno.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <time.h>  // for clockid_t
+
+#include "GeckoProfiler.h"
+#include "mozilla/Assertions.h"
+#include "mozilla/ClearOnShutdown.h"
+#include "mozilla/StaticMutex.h"
+#include "mozilla/PodOperations.h"
+#include "nsThreadUtils.h"
+#include "mozilla/Telemetry.h"
+#include "sandbox/linux/system_headers/linux_syscalls.h"
+
+// Distinguish architectures for the telemetry key.
+#if defined(__i386__)
+#  define SANDBOX_ARCH_NAME "x86"
+#elif defined(__x86_64__)
+#  define SANDBOX_ARCH_NAME "amd64"
+#elif defined(__arm__)
+#  define SANDBOX_ARCH_NAME "arm"
+#elif defined(__aarch64__)
+#  define SANDBOX_ARCH_NAME "arm64"
+#else
+#  error "unrecognized architecture"
+#endif
+
+namespace mozilla {
+
+StaticAutoPtr<SandboxReporter> SandboxReporter::sSingleton;
+
+SandboxReporter::SandboxReporter()
+    : mClientFd(-1),
+      mServerFd(-1),
+      mMutex("SandboxReporter"),
+      mBuffer(MakeUnique<SandboxReport[]>(kSandboxReporterBufferSize)),
+      mCount(0) {}
+
+bool SandboxReporter::Init() {
+  int fds[2];
+
+  if (0 != socketpair(AF_UNIX, SOCK_SEQPACKET | SOCK_CLOEXEC, 0, fds)) {
+    SANDBOX_LOG_ERRNO("SandboxReporter: socketpair failed");
+    return false;
+  }
+  mClientFd = fds[0];
+  mServerFd = fds[1];
+
+  if (!PlatformThread::Create(0, this, &mThread)) {
+    SANDBOX_LOG_ERRNO("SandboxReporter: thread creation failed");
+    close(mClientFd);
+    close(mServerFd);
+    mClientFd = mServerFd = -1;
+    return false;
+  }
+
+  return true;
+}
+
+SandboxReporter::~SandboxReporter() {
+  if (mServerFd < 0) {
+    return;
+  }
+  shutdown(mServerFd, SHUT_RD);
+  PlatformThread::Join(mThread);
+  close(mServerFd);
+  close(mClientFd);
+}
+
+/* static */
+SandboxReporter* SandboxReporter::Singleton() {
+  static StaticMutex sMutex MOZ_UNANNOTATED;
+  StaticMutexAutoLock lock(sMutex);
+
+  if (sSingleton == nullptr) {
+    sSingleton = new SandboxReporter();
+    if (!sSingleton->Init()) {
+      // If socketpair or thread creation failed, trying to continue
+      // with child process creation is unlikely to succeed; crash
+      // instead of trying to handle that case.
+      MOZ_CRASH("SandboxRepoter::Singleton: initialization failed");
+    }
+    // ClearOnShutdown must be called on the main thread and will
+    // destroy the object on the main thread.  That *should* be safe;
+    // the destructor will shut down the reporter's socket reader
+    // thread before freeing anything, IPC should already be shut down
+    // by that point (so it won't race by calling Singleton()), all
+    // non-main XPCOM threads will also be shut down, and currently
+    // the only other user is the main-thread-only Troubleshoot.sys.mjs.
+    NS_DispatchToMainThread(NS_NewRunnableFunction(
+        "SandboxReporter::Singleton", [] { ClearOnShutdown(&sSingleton); }));
+  }
+  return sSingleton.get();
+}
+
+void SandboxReporter::GetClientFileDescriptorMapping(int* aSrcFd,
+                                                     int* aDstFd) const {
+  MOZ_ASSERT(mClientFd >= 0);
+  *aSrcFd = mClientFd;
+  *aDstFd = kSandboxReporterFileDesc;
+}
+
+// This function is mentioned in Histograms.json; keep that in mind if
+// it's renamed or moved to a different file.
+static void SubmitToTelemetry(const SandboxReport& aReport) {
+  nsAutoCString key;
+  // The key contains the process type, something that uniquely
+  // identifies the syscall, and in some cases arguments (see below
+  // for details).  Arbitrary formatting choice: fields in the key are
+  // separated by ':', except that (arch, syscall#) pairs are
+  // separated by '/'.
+  //
+  // Examples:
+  // * "content:x86/64"           (bug 1285768)
+  // * "content:x86_64/110"       (bug 1285768)
+  // * "gmp:madvise:8"            (bug 1303813)
+  // * "content:clock_gettime:4"  (bug 1334687)
+
+  switch (aReport.mProcType) {
+    case SandboxReport::ProcType::CONTENT:
+      key.AppendLiteral("content");
+      break;
+    case SandboxReport::ProcType::FILE:
+      key.AppendLiteral("file");
+      break;
+    case SandboxReport::ProcType::MEDIA_PLUGIN:
+      key.AppendLiteral("gmp");
+      break;
+    case SandboxReport::ProcType::RDD:
+      key.AppendLiteral("rdd");
+      break;
+    case SandboxReport::ProcType::SOCKET_PROCESS:
+      key.AppendLiteral("socket");
+      break;
+    case SandboxReport::ProcType::UTILITY:
+      key.AppendLiteral("utility");
+      break;
+    default:
+      MOZ_ASSERT(false);
+  }
+  key.Append(':');
+
+  switch (aReport.mSyscall) {
+    // Syscalls that are filtered by arguments in one or more of the
+    // policies in SandboxFilter.cpp should generally have those
+    // arguments included here, but don't include irrelevant
+    // information that would cause large numbers of distinct keys for
+    // the same issue -- for example, pids or pointers.  When in
+    // doubt, include arguments only if they would typically be
+    // constants (or asm immediates) in the code making the syscall.
+    //
+    // Also, keep in mind that this is opt-out data collection and
+    // privacy is critical.  While it's unlikely that information in
+    // the register values alone could personally identify a user
+    // (see also crash reports, where register contents are public),
+    // and the guidelines in the previous paragraph should rule out
+    // any value that's capable of holding PII, please be careful.
+    //
+    // When making changes here, please consult with a data steward
+    // (https://wiki.mozilla.org/Firefox/Data_Collection) and ask for
+    // a review if you are unsure about anything.
+
+    // This macro includes one argument as a decimal number; it should
+    // be enough for most cases.
+#define ARG_DECIMAL(name, idx)         \
+  case __NR_##name:                    \
+    key.AppendLiteral(#name ":");      \
+    key.AppendInt(aReport.mArgs[idx]); \
+    break
+
+    // This may be more convenient if the argument is a set of bit flags.
+#define ARG_HEX(name, idx)                 \
+  case __NR_##name:                        \
+    key.AppendLiteral(#name ":0x");        \
+    key.AppendInt(aReport.mArgs[idx], 16); \
+    break
+
+    // clockid_t is annoying: there are a small set of fixed timers,
+    // but it can also encode a pid/tid (or a fd for a hardware clock
+    // device); in this case the value is negative.
+#define ARG_CLOCKID(name, idx)                            \
+  case __NR_##name:                                       \
+    key.AppendLiteral(#name ":");                         \
+    if (static_cast<clockid_t>(aReport.mArgs[idx]) < 0) { \
+      key.AppendLiteral("dynamic");                       \
+    } else {                                              \
+      key.AppendInt(aReport.mArgs[idx]);                  \
+    }                                                     \
+    break
+
+    // The syscalls handled specially:
+
+    ARG_HEX(clone, 0);              // flags
+    ARG_DECIMAL(prctl, 0);          // option
+    ARG_HEX(ioctl, 1);              // request
+    ARG_DECIMAL(fcntl, 1);          // cmd
+    ARG_DECIMAL(madvise, 2);        // advice
+    ARG_CLOCKID(clock_gettime, 0);  // clk_id
+
+#ifdef __NR_socketcall
+    ARG_DECIMAL(socketcall, 0);  // call
+#endif
+#ifdef __NR_ipc
+    ARG_DECIMAL(ipc, 0);  // call
+#endif
+
+#undef ARG_DECIMAL
+#undef ARG_HEX
+#undef ARG_CLOCKID
+
+    default:
+      // Otherwise just use the number, with the arch name to disambiguate.
+      key.Append(SANDBOX_ARCH_NAME "/");
+      key.AppendInt(aReport.mSyscall);
+  }
+
+  Telemetry::Accumulate(Telemetry::SANDBOX_REJECTED_SYSCALLS, key);
+}
+
+void SandboxReporter::AddOne(const SandboxReport& aReport) {
+  SubmitToTelemetry(aReport);
+
+  MutexAutoLock lock(mMutex);
+  mBuffer[mCount % kSandboxReporterBufferSize] = aReport;
+  ++mCount;
+}
+
+void SandboxReporter::ThreadMain(void) {
+  // Create a nsThread wrapper for the current platform thread, and register it
+  // with the thread manager.
+  (void)NS_GetCurrentThread();
+
+  PlatformThread::SetName("SandboxReporter");
+  AUTO_PROFILER_REGISTER_THREAD("SandboxReporter");
+
+  for (;;) {
+    SandboxReport rep;
+    struct iovec iov;
+    struct msghdr msg;
+
+    iov.iov_base = &rep;
+    iov.iov_len = sizeof(rep);
+    PodZero(&msg);
+    msg.msg_iov = &iov;
+    msg.msg_iovlen = 1;
+
+    const auto recvd = recvmsg(mServerFd, &msg, 0);
+    if (recvd < 0) {
+      if (errno == EINTR) {
+        continue;
+      }
+      SANDBOX_LOG_ERRNO("SandboxReporter: recvmsg");
+    }
+    if (recvd <= 0) {
+      break;
+    }
+
+    if (static_cast<size_t>(recvd) < sizeof(rep)) {
+      SANDBOX_LOG("SandboxReporter: packet too short (%d < %d)", recvd,
+                  sizeof(rep));
+      continue;
+    }
+    if (msg.msg_flags & MSG_TRUNC) {
+      SANDBOX_LOG("SandboxReporter: packet too long");
+      continue;
+    }
+
+    AddOne(rep);
+  }
+}
+
+SandboxReporter::Snapshot SandboxReporter::GetSnapshot() {
+  Snapshot snapshot;
+  MutexAutoLock lock(mMutex);
+
+  const uint64_t bufSize = static_cast<uint64_t>(kSandboxReporterBufferSize);
+  const uint64_t start = std::max(mCount, bufSize) - bufSize;
+  snapshot.mOffset = start;
+  snapshot.mReports.Clear();
+  snapshot.mReports.SetCapacity(mCount - start);
+  for (size_t i = start; i < mCount; ++i) {
+    const SandboxReport* rep = &mBuffer[i % kSandboxReporterBufferSize];
+    MOZ_ASSERT(rep->IsValid());
+    snapshot.mReports.AppendElement(*rep);
+  }
+  return snapshot;
+}
+
+}  // namespace mozilla
diff --git a/security/sandbox/linux/reporter/SandboxReporter.h b/security/sandbox/linux/reporter/SandboxReporter.h
new file mode 100644
index 0000000000..0969111c9c
--- /dev/null
+++ b/security/sandbox/linux/reporter/SandboxReporter.h
@@ -0,0 +1,86 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_SandboxReporter_h
+#define mozilla_SandboxReporter_h
+
+#include "SandboxReporterCommon.h"
+
+#include "base/platform_thread.h"
+#include "mozilla/StaticPtr.h"
+#include "mozilla/Mutex.h"
+#include "mozilla/Types.h"
+#include "mozilla/UniquePtr.h"
+#include "nsTArray.h"
+
+namespace mozilla {
+
+// This object collects the SandboxReport messages from all of the
+// child processes, submits them to Telemetry, and maintains a ring
+// buffer of the last kSandboxReporterBufferSize reports.
+class SandboxReporter final : public PlatformThread::Delegate {
+ public:
+  // For normal use, don't construct this directly; use the
+  // Singleton() method.
+  //
+  // For unit testing, use this constructor followed by the Init
+  // method; the object isn't usable unless Init returns true.
+  explicit SandboxReporter();
+  ~SandboxReporter();
+
+  // See above; this method is not thread-safe.
+  bool Init();
+
+  // Used in GeckoChildProcessHost to connect the child process's
+  // client to this report collector.
+  void GetClientFileDescriptorMapping(int* aSrcFd, int* aDstFd) const;
+
+  // A snapshot of the report ring buffer; element 0 of `mReports` is
+  // the `mOffset`th report to be received, and so on.
+  struct Snapshot {
+    // The buffer has to fit in memory, but the total number of
+    // reports received in the session can increase without bound and
+    // could potentially overflow a uint32_t, so this is 64-bit.
+    // (It's exposed to JS as a 53-bit int, effectively, but that
+    // should also be large enough.)
+    uint64_t mOffset;
+    nsTArray<SandboxReport> mReports;
+  };
+
+  // Read the ring buffer contents; this method is thread-safe.
+  Snapshot GetSnapshot();
+
+  // Gets or creates the singleton report collector.  Crashes if
+  // initialization fails (if a socketpair and/or thread can't be
+  // created, there was almost certainly about to be a crash anyway).
+  // Thread-safe as long as the pointer isn't used during/after XPCOM
+  // shutdown.
+  static SandboxReporter* Singleton();
+
+ private:
+  // These are constant over the life of the object:
+  int mClientFd;
+  int mServerFd;
+  PlatformThreadHandle mThread;
+
+  Mutex mMutex MOZ_UNANNOTATED;
+  // These are protected by mMutex:
+  UniquePtr<SandboxReport[]> mBuffer;
+  uint64_t mCount;
+
+  static StaticAutoPtr<SandboxReporter> sSingleton;
+
+  void ThreadMain(void) override;
+  void AddOne(const SandboxReport& aReport);
+};
+
+// This is a constant so the % operations can be optimized.  This is
+// exposed in the header so that unit tests can see it.
+static const size_t kSandboxReporterBufferSize = 32;
+
+}  // namespace mozilla
+
+#endif  // mozilla_SandboxReporter_h
diff --git a/security/sandbox/linux/reporter/SandboxReporterCommon.h b/security/sandbox/linux/reporter/SandboxReporterCommon.h
new file mode 100644
index 0000000000..9bfb40bb98
--- /dev/null
+++ b/security/sandbox/linux/reporter/SandboxReporterCommon.h
@@ -0,0 +1,66 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_SandboxReporterCommon_h
+#define mozilla_SandboxReporterCommon_h
+
+#include "mozilla/IntegerTypeTraits.h"
+#include "mozilla/Types.h"
+
+#include <sys/types.h>
+
+// Note: this is also used in libmozsandbox, so dependencies on
+// symbols from libxul probably won't work.
+
+namespace mozilla {
+static const size_t kSandboxSyscallArguments = 6;
+// fds 0-2: stdio; fd 3: IPC; fd 4: crash reporter.  (The IPC child
+// process launching code will check that we don't try to use the same
+// fd twice.)
+static const int kSandboxReporterFileDesc = 5;
+
+// This struct represents a system call that was rejected by a
+// seccomp-bpf policy.
+struct SandboxReport {
+  // In the future this may include finer distinctions than
+  // GeckoProcessType -- e.g., whether a content process can load
+  // file:/// URLs, or if it's reserved for content with certain
+  // user-granted permissions.
+  enum class ProcType : uint8_t {
+    CONTENT,
+    FILE,
+    MEDIA_PLUGIN,
+    RDD,
+    SOCKET_PROCESS,
+    UTILITY,
+  };
+
+  // The syscall number and arguments are usually `unsigned long`, but
+  // that causes ambiguous overload errors with nsACString::AppendInt.
+  using ULong = UnsignedStdintTypeForSize<sizeof(unsigned long)>::Type;
+
+  // This time uses CLOCK_MONOTONIC_COARSE.  Displaying or reporting
+  // it should usually be done relative to the current value of that
+  // clock (or the time at some other event of interest, like a
+  // subsequent crash).
+  struct timespec mTime;
+
+  // The pid/tid values, like every other field in this struct, aren't
+  // authenticated and a compromised process could send anything, so
+  // use the values with caution.
+  pid_t mPid;
+  pid_t mTid;
+  ProcType mProcType;
+  ULong mSyscall;
+  ULong mArgs[kSandboxSyscallArguments];
+
+  SandboxReport() : mPid(0) {}
+  bool IsValid() const { return mPid > 0; }
+};
+
+}  // namespace mozilla
+
+#endif  // mozilla_SandboxReporterCommon_h
diff --git a/security/sandbox/linux/reporter/SandboxReporterWrappers.cpp b/security/sandbox/linux/reporter/SandboxReporterWrappers.cpp
new file mode 100644
index 0000000000..755e8e858d
--- /dev/null
+++ b/security/sandbox/linux/reporter/SandboxReporterWrappers.cpp
@@ -0,0 +1,199 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozISandboxReporter.h"
+#include "SandboxReporter.h"
+
+#include <time.h>
+
+#include "mozilla/Assertions.h"
+#include "mozilla/Components.h"
+#include "nsCOMPtr.h"
+#include "nsPrintfCString.h"
+#include "nsTArray.h"
+#include "nsXULAppAPI.h"
+
+using namespace mozilla;
+
+namespace mozilla {
+
+class SandboxReportWrapper final : public mozISandboxReport {
+ public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_MOZISANDBOXREPORT
+
+  explicit SandboxReportWrapper(const SandboxReport& aReport)
+      : mReport(aReport) {}
+
+ private:
+  ~SandboxReportWrapper() = default;
+  SandboxReport mReport;
+};
+
+NS_IMPL_ISUPPORTS(SandboxReportWrapper, mozISandboxReport)
+
+/* readonly attribute uint64_t msecAgo; */
+NS_IMETHODIMP SandboxReportWrapper::GetMsecAgo(uint64_t* aMsec) {
+  struct timespec then = mReport.mTime, now = {0, 0};
+  clock_gettime(CLOCK_MONOTONIC_COARSE, &now);
+
+  const uint64_t now_msec = uint64_t(now.tv_sec) * 1000 + now.tv_nsec / 1000000;
+  const uint64_t then_msec =
+      uint64_t(then.tv_sec) * 1000 + then.tv_nsec / 1000000;
+  MOZ_DIAGNOSTIC_ASSERT(now_msec >= then_msec);
+  if (now_msec >= then_msec) {
+    *aMsec = now_msec - then_msec;
+  } else {
+    *aMsec = 0;
+  }
+  return NS_OK;
+}
+
+/* readonly attribute int32_t pid; */
+NS_IMETHODIMP SandboxReportWrapper::GetPid(int32_t* aPid) {
+  *aPid = mReport.mPid;
+  return NS_OK;
+}
+
+/* readonly attribute int32_t tid; */
+NS_IMETHODIMP SandboxReportWrapper::GetTid(int32_t* aTid) {
+  *aTid = mReport.mTid;
+  return NS_OK;
+}
+
+/* readonly attribute ACString procType; */
+NS_IMETHODIMP SandboxReportWrapper::GetProcType(nsACString& aProcType) {
+  switch (mReport.mProcType) {
+    case SandboxReport::ProcType::CONTENT:
+      aProcType.AssignLiteral("content");
+      return NS_OK;
+    case SandboxReport::ProcType::FILE:
+      aProcType.AssignLiteral("file");
+      return NS_OK;
+    case SandboxReport::ProcType::MEDIA_PLUGIN:
+      aProcType.AssignLiteral("mediaPlugin");
+      return NS_OK;
+    case SandboxReport::ProcType::RDD:
+      aProcType.AssignLiteral("dataDecoder");
+      return NS_OK;
+    case SandboxReport::ProcType::SOCKET_PROCESS:
+      aProcType.AssignLiteral("socketProcess");
+      return NS_OK;
+    case SandboxReport::ProcType::UTILITY:
+      aProcType.AssignLiteral("utility");
+      return NS_OK;
+    default:
+      MOZ_ASSERT(false);
+      return NS_ERROR_UNEXPECTED;
+  }
+}
+
+/* readonly attribute uint32_t syscall; */
+NS_IMETHODIMP SandboxReportWrapper::GetSyscall(uint32_t* aSyscall) {
+  *aSyscall = static_cast<uint32_t>(mReport.mSyscall);
+  MOZ_ASSERT(static_cast<SandboxReport::ULong>(*aSyscall) == mReport.mSyscall);
+  return NS_OK;
+}
+
+/* readonly attribute uint32_t numArgs; */
+NS_IMETHODIMP SandboxReportWrapper::GetNumArgs(uint32_t* aNumArgs) {
+  *aNumArgs = static_cast<uint32_t>(kSandboxSyscallArguments);
+  return NS_OK;
+}
+
+/* ACString getArg (in uint32_t aIndex); */
+NS_IMETHODIMP SandboxReportWrapper::GetArg(uint32_t aIndex,
+                                           nsACString& aRetval) {
+  if (aIndex >= kSandboxSyscallArguments) {
+    return NS_ERROR_INVALID_ARG;
+  }
+  const auto arg = mReport.mArgs[aIndex];
+  nsAutoCString str;
+  // Use decimal for smaller numbers (more likely ints) and hex for
+  // larger (more likely pointers).  This cutoff is arbitrary.
+  if (arg >= 1000000) {
+    str.AppendLiteral("0x");
+    str.AppendInt(arg, 16);
+  } else {
+    str.AppendInt(arg, 10);
+  }
+  aRetval = str;
+  return NS_OK;
+}
+
+class SandboxReportArray final : public mozISandboxReportArray {
+ public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_MOZISANDBOXREPORTARRAY
+
+  explicit SandboxReportArray(SandboxReporter::Snapshot&& aSnap)
+      : mOffset(aSnap.mOffset), mArray(std::move(aSnap.mReports)) {}
+
+ private:
+  ~SandboxReportArray() = default;
+  uint64_t mOffset;
+  nsTArray<SandboxReport> mArray;
+};
+
+NS_IMPL_ISUPPORTS(SandboxReportArray, mozISandboxReportArray)
+
+/* readonly attribute uint64_t begin; */
+NS_IMETHODIMP SandboxReportArray::GetBegin(uint64_t* aBegin) {
+  *aBegin = mOffset;
+  return NS_OK;
+}
+
+/* readonly attribute uint64_t end; */
+NS_IMETHODIMP SandboxReportArray::GetEnd(uint64_t* aEnd) {
+  *aEnd = mOffset + mArray.Length();
+  return NS_OK;
+}
+
+/* mozISandboxReport getElement (in uint64_t aIndex); */
+NS_IMETHODIMP SandboxReportArray::GetElement(uint64_t aIndex,
+                                             mozISandboxReport** aRetval) {
+  uint64_t relIndex = aIndex - mOffset;
+  if (relIndex >= mArray.Length()) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  nsCOMPtr<mozISandboxReport> wrapper =
+      new SandboxReportWrapper(mArray[relIndex]);
+  wrapper.forget(aRetval);
+  return NS_OK;
+}
+
+class SandboxReporterWrapper final : public mozISandboxReporter {
+ public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_MOZISANDBOXREPORTER
+
+  SandboxReporterWrapper() = default;
+
+ private:
+  ~SandboxReporterWrapper() = default;
+};
+
+NS_IMPL_ISUPPORTS(SandboxReporterWrapper, mozISandboxReporter)
+
+/* mozISandboxReportArray snapshot(); */
+NS_IMETHODIMP SandboxReporterWrapper::Snapshot(
+    mozISandboxReportArray** aRetval) {
+  if (!XRE_IsParentProcess()) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  nsCOMPtr<mozISandboxReportArray> wrapper =
+      new SandboxReportArray(SandboxReporter::Singleton()->GetSnapshot());
+  wrapper.forget(aRetval);
+  return NS_OK;
+}
+
+}  // namespace mozilla
+
+NS_IMPL_COMPONENT_FACTORY(mozISandboxReporter) {
+  return MakeAndAddRef<SandboxReporterWrapper>().downcast<nsISupports>();
+}
diff --git a/security/sandbox/linux/reporter/components.conf b/security/sandbox/linux/reporter/components.conf
new file mode 100644
index 0000000000..7bd278f349
--- /dev/null
+++ b/security/sandbox/linux/reporter/components.conf
@@ -0,0 +1,13 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+Classes = [
+    {
+        'cid': '{5118a6f9-2493-4f97-9552-620663e03cb3}',
+        'contract_ids': ['@mozilla.org/sandbox/syscall-reporter;1'],
+        'type': 'mozISandboxReporter',
+    },
+]
diff --git a/security/sandbox/linux/reporter/moz.build b/security/sandbox/linux/reporter/moz.build
new file mode 100644
index 0000000000..ebc11c5ab6
--- /dev/null
+++ b/security/sandbox/linux/reporter/moz.build
@@ -0,0 +1,36 @@
+# -*- Mode: python; python-indent: 4; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+EXPORTS.mozilla += [
+    "SandboxReporter.h",
+    "SandboxReporterCommon.h",
+]
+
+UNIFIED_SOURCES += [
+    "SandboxReporter.cpp",
+    "SandboxReporterWrappers.cpp",
+]
+
+XPCOM_MANIFESTS += [
+    "components.conf",
+]
+
+LOCAL_INCLUDES += [
+    "/security/sandbox/linux",  # SandboxLogging.h
+]
+
+# Need this for base::PlatformThread
+include("/ipc/chromium/chromium-config.mozbuild")
+
+# Need this for safe_sprintf.h used by SandboxLogging.h,
+# but it has to be after ipc/chromium/src.
+LOCAL_INCLUDES += [
+    "/security/sandbox/chromium",
+]
+
+FINAL_LIBRARY = "xul"
+
+REQUIRES_UNIFIED_BUILD = True