Merge "[GWP-ASan] Add GWP-ASan information to tombstones."

debuggerd/Android.bp

@@ -171,6 +171,7 @@ cc_library_static {
 
     srcs: [
         "libdebuggerd/backtrace.cpp",
+        "libdebuggerd/gwp_asan.cpp",
         "libdebuggerd/open_files_list.cpp",
         "libdebuggerd/tombstone.cpp",
         "libdebuggerd/utility.cpp",
@@ -181,7 +182,10 @@ cc_library_static {
 
     // Needed for private/bionic_fdsan.h
     include_dirs: ["bionic/libc"],
-    header_libs: ["bionic_libc_platform_headers"],
+    header_libs: [
+        "bionic_libc_platform_headers",
+        "gwp_asan_headers",
+    ],
 
     static_libs: [
         "libdexfile_support_static",  // libunwindstack dependency
@@ -192,6 +196,8 @@ cc_library_static {
         "liblog",
     ],
 
+    whole_static_libs: ["gwp_asan_crash_handler"],
+
     target: {
         recovery: {
             exclude_static_libs: [
@@ -246,10 +252,12 @@ cc_test {
 
     static_libs: [
         "libdebuggerd",
+        "libgmock",
     ],
 
     header_libs: [
         "bionic_libc_platform_headers",
+        "gwp_asan_headers",
     ],
 
     local_include_dirs: [

debuggerd/client/debuggerd_client_test.cpp

@@ -73,8 +73,8 @@ TEST(debuggerd_client, race) {
   unique_fd pipe_read, pipe_write;
   ASSERT_TRUE(Pipe(&pipe_read, &pipe_write));
 
-  // 64 MiB should be enough for everyone.
+  // 16 MiB should be enough for everyone.
-  constexpr int PIPE_SIZE = 64 * 1024 * 1024;
+  constexpr int PIPE_SIZE = 16 * 1024 * 1024;
   ASSERT_EQ(PIPE_SIZE, fcntl(pipe_read.get(), F_SETPIPE_SZ, PIPE_SIZE));
 
   // Wait for a bit to let the child spawn all of its threads.

debuggerd/crash_dump.cpp

@@ -255,7 +255,8 @@ static void ParseArgs(int argc, char** argv, pid_t* pseudothread_tid, DebuggerdD
 
 static void ReadCrashInfo(unique_fd& fd, siginfo_t* siginfo,
                           std::unique_ptr<unwindstack::Regs>* regs, uintptr_t* abort_msg_address,
-                          uintptr_t* fdsan_table_address) {
+                          uintptr_t* fdsan_table_address, uintptr_t* gwp_asan_state,
+                          uintptr_t* gwp_asan_metadata) {
   std::aligned_storage<sizeof(CrashInfo) + 1, alignof(CrashInfo)>::type buf;
   CrashInfo* crash_info = reinterpret_cast<CrashInfo*>(&buf);
   ssize_t rc = TEMP_FAILURE_RETRY(read(fd.get(), &buf, sizeof(buf)));
@@ -272,6 +273,10 @@ static void ReadCrashInfo(unique_fd& fd, siginfo_t* siginfo,
         expected_size = sizeof(CrashInfoHeader) + sizeof(CrashInfoDataV2);
         break;
 
+      case 3:
+        expected_size = sizeof(CrashInfoHeader) + sizeof(CrashInfoDataV3);
+        break;
+
       default:
         LOG(FATAL) << "unexpected CrashInfo version: " << crash_info->header.version;
         break;
@@ -284,7 +289,13 @@ static void ReadCrashInfo(unique_fd& fd, siginfo_t* siginfo,
   }
 
   *fdsan_table_address = 0;
+  *gwp_asan_state = 0;
+  *gwp_asan_metadata = 0;
   switch (crash_info->header.version) {
+    case 3:
+      *gwp_asan_state = crash_info->data.v3.gwp_asan_state;
+      *gwp_asan_metadata = crash_info->data.v3.gwp_asan_metadata;
+      FALLTHROUGH_INTENDED;
     case 2:
       *fdsan_table_address = crash_info->data.v2.fdsan_table_address;
       FALLTHROUGH_INTENDED;
@@ -416,6 +427,8 @@ int main(int argc, char** argv) {
   DebuggerdDumpType dump_type;
   uintptr_t abort_msg_address = 0;
   uintptr_t fdsan_table_address = 0;
+  uintptr_t gwp_asan_state = 0;
+  uintptr_t gwp_asan_metadata = 0;
 
   Initialize(argv);
   ParseArgs(argc, argv, &pseudothread_tid, &dump_type);
@@ -477,7 +490,7 @@ int main(int argc, char** argv) {
       if (thread == g_target_thread) {
         // Read the thread's registers along with the rest of the crash info out of the pipe.
         ReadCrashInfo(input_pipe, &siginfo, &info.registers, &abort_msg_address,
-                      &fdsan_table_address);
+                      &fdsan_table_address, &gwp_asan_state, &gwp_asan_metadata);
         info.siginfo = &siginfo;
         info.signo = info.siginfo->si_signo;
       } else {
@@ -592,7 +605,8 @@ int main(int argc, char** argv) {
     {
       ATRACE_NAME("engrave_tombstone");
       engrave_tombstone(std::move(g_output_fd), &unwinder, thread_info, g_target_thread,
-                        abort_msg_address, &open_files, &amfd_data);
+                        abort_msg_address, &open_files, &amfd_data, gwp_asan_state,
+                        gwp_asan_metadata);
     }
   }
 

debuggerd/handler/debuggerd_handler.cpp

@@ -49,6 +49,7 @@
 #include <sys/wait.h>
 #include <unistd.h>
 
+#include <android-base/macros.h>
 #include <android-base/unique_fd.h>
 #include <async_safe/log.h>
 #include <bionic/reserved_signals.h>
@@ -298,6 +299,8 @@ struct debugger_thread_info {
   void* ucontext;
   uintptr_t abort_msg;
   uintptr_t fdsan_table;
+  uintptr_t gwp_asan_state;
+  uintptr_t gwp_asan_metadata;
 };
 
 // Logging and contacting debuggerd requires free file descriptors, which we might not have.
@@ -342,23 +345,25 @@ static int debuggerd_dispatch_pseudothread(void* arg) {
   }
 
   // ucontext_t is absurdly large on AArch64, so piece it together manually with writev.
-  uint32_t version = 2;
+  uint32_t version = 3;
-  constexpr size_t expected = sizeof(CrashInfoHeader) + sizeof(CrashInfoDataV2);
+  constexpr size_t expected = sizeof(CrashInfoHeader) + sizeof(CrashInfoDataV3);
 
   errno = 0;
   if (fcntl(output_write.get(), F_SETPIPE_SZ, expected) < static_cast<int>(expected)) {
     fatal_errno("failed to set pipe buffer size");
   }
 
-  struct iovec iovs[5] = {
+  struct iovec iovs[] = {
       {.iov_base = &version, .iov_len = sizeof(version)},
       {.iov_base = thread_info->siginfo, .iov_len = sizeof(siginfo_t)},
       {.iov_base = thread_info->ucontext, .iov_len = sizeof(ucontext_t)},
       {.iov_base = &thread_info->abort_msg, .iov_len = sizeof(uintptr_t)},
       {.iov_base = &thread_info->fdsan_table, .iov_len = sizeof(uintptr_t)},
+      {.iov_base = &thread_info->gwp_asan_state, .iov_len = sizeof(uintptr_t)},
+      {.iov_base = &thread_info->gwp_asan_metadata, .iov_len = sizeof(uintptr_t)},
   };
 
-  ssize_t rc = TEMP_FAILURE_RETRY(writev(output_write.get(), iovs, 5));
+  ssize_t rc = TEMP_FAILURE_RETRY(writev(output_write.get(), iovs, arraysize(iovs)));
   if (rc == -1) {
     fatal_errno("failed to write crash info");
   } else if (rc != expected) {
@@ -485,6 +490,8 @@ static void debuggerd_signal_handler(int signal_number, siginfo_t* info, void* c
   }
 
   void* abort_message = nullptr;
+  const gwp_asan::AllocatorState* gwp_asan_state = nullptr;
+  const gwp_asan::AllocationMetadata* gwp_asan_metadata = nullptr;
   uintptr_t si_val = reinterpret_cast<uintptr_t>(info->si_ptr);
   if (signal_number == BIONIC_SIGNAL_DEBUGGER) {
     if (info->si_code == SI_QUEUE && info->si_pid == __getpid()) {
@@ -499,6 +506,12 @@ static void debuggerd_signal_handler(int signal_number, siginfo_t* info, void* c
     if (g_callbacks.get_abort_message) {
       abort_message = g_callbacks.get_abort_message();
     }
+    if (g_callbacks.get_gwp_asan_state) {
+      gwp_asan_state = g_callbacks.get_gwp_asan_state();
+    }
+    if (g_callbacks.get_gwp_asan_metadata) {
+      gwp_asan_metadata = g_callbacks.get_gwp_asan_metadata();
+    }
   }
 
   // If sival_int is ~0, it means that the fallback handler has been called
@@ -532,6 +545,8 @@ static void debuggerd_signal_handler(int signal_number, siginfo_t* info, void* c
       .ucontext = context,
       .abort_msg = reinterpret_cast<uintptr_t>(abort_message),
       .fdsan_table = reinterpret_cast<uintptr_t>(android_fdsan_get_fd_table()),
+      .gwp_asan_state = reinterpret_cast<uintptr_t>(gwp_asan_state),
+      .gwp_asan_metadata = reinterpret_cast<uintptr_t>(gwp_asan_metadata),
   };
 
   // Set PR_SET_DUMPABLE to 1, so that crash_dump can ptrace us.

debuggerd/include/debuggerd/handler.h

@@ -24,11 +24,20 @@
 
 __BEGIN_DECLS
 
+// Forward declare these classes so not everyone has to include GWP-ASan
+// headers.
+namespace gwp_asan {
+struct AllocatorState;
+struct AllocationMetadata;
+};  // namespace gwp_asan
+
 // These callbacks are called in a signal handler, and thus must be async signal safe.
 // If null, the callbacks will not be called.
 typedef struct {
   struct abort_msg_t* (*get_abort_message)();
   void (*post_dump)();
+  const struct gwp_asan::AllocatorState* (*get_gwp_asan_state)();
+  const struct gwp_asan::AllocationMetadata* (*get_gwp_asan_metadata)();
 } debuggerd_callbacks_t;
 
 void debuggerd_init(debuggerd_callbacks_t* callbacks);

debuggerd/libdebuggerd/gwp_asan.cpp

@@ -0,0 +1,273 @@
+/*
+ * Copyright (C) 2020 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.
+ */
+
+#include "libdebuggerd/gwp_asan.h"
+#include "libdebuggerd/utility.h"
+
+#include "gwp_asan/common.h"
+#include "gwp_asan/crash_handler.h"
+
+#include <unwindstack/Maps.h>
+#include <unwindstack/Memory.h>
+#include <unwindstack/Regs.h>
+#include <unwindstack/Unwinder.h>
+
+// Retrieve GWP-ASan state from `state_addr` inside the process at
+// `process_memory`. Place the state into `*state`.
+static bool retrieve_gwp_asan_state(unwindstack::Memory* process_memory, uintptr_t state_addr,
+                                    gwp_asan::AllocatorState* state) {
+  return process_memory->ReadFully(state_addr, state, sizeof(*state));
+}
+
+// Retrieve the GWP-ASan metadata pool from `metadata_addr` inside the process
+// at `process_memory`. The number of metadata slots is retrieved from the
+// allocator state provided. This function returns a heap-allocated copy of the
+// metadata pool whose ownership should be managed by the caller. Returns
+// nullptr on failure.
+static const gwp_asan::AllocationMetadata* retrieve_gwp_asan_metadata(
+    unwindstack::Memory* process_memory, const gwp_asan::AllocatorState& state,
+    uintptr_t metadata_addr) {
+  if (state.MaxSimultaneousAllocations > 1024) {
+    ALOGE(
+        "Error when retrieving GWP-ASan metadata, MSA from state (%zu) "
+        "exceeds maximum allowed (1024).",
+        state.MaxSimultaneousAllocations);
+    return nullptr;
+  }
+
+  gwp_asan::AllocationMetadata* meta =
+      new gwp_asan::AllocationMetadata[state.MaxSimultaneousAllocations];
+  if (!process_memory->ReadFully(metadata_addr, meta,
+                                 sizeof(*meta) * state.MaxSimultaneousAllocations)) {
+    ALOGE(
+        "Error when retrieving GWP-ASan metadata, could not retrieve %zu "
+        "pieces of metadata.",
+        state.MaxSimultaneousAllocations);
+    delete[] meta;
+    meta = nullptr;
+  }
+  return meta;
+}
+
+GwpAsanCrashData::GwpAsanCrashData(unwindstack::Memory* process_memory,
+                                   uintptr_t gwp_asan_state_ptr, uintptr_t gwp_asan_metadata_ptr,
+                                   const ThreadInfo& thread_info) {
+  if (!process_memory || !gwp_asan_metadata_ptr || !gwp_asan_state_ptr) return;
+  // Extract the GWP-ASan regions from the dead process.
+  if (!retrieve_gwp_asan_state(process_memory, gwp_asan_state_ptr, &state_)) return;
+  metadata_.reset(retrieve_gwp_asan_metadata(process_memory, state_, gwp_asan_metadata_ptr));
+  if (!metadata_.get()) return;
+
+  // Get the external crash address from the thread info.
+  crash_address_ = 0u;
+  if (signal_has_si_addr(thread_info.siginfo)) {
+    crash_address_ = reinterpret_cast<uintptr_t>(thread_info.siginfo->si_addr);
+  }
+
+  // Ensure the error belongs to GWP-ASan.
+  if (!__gwp_asan_error_is_mine(&state_, crash_address_)) return;
+
+  is_gwp_asan_responsible_ = true;
+  thread_id_ = thread_info.tid;
+
+  // Grab the internal error address, if it exists.
+  uintptr_t internal_crash_address = __gwp_asan_get_internal_crash_address(&state_);
+  if (internal_crash_address) {
+    crash_address_ = internal_crash_address;
+  }
+
+  // Get other information from the internal state.
+  error_ = __gwp_asan_diagnose_error(&state_, metadata_.get(), crash_address_);
+  error_string_ = gwp_asan::ErrorToString(error_);
+  responsible_allocation_ = __gwp_asan_get_metadata(&state_, metadata_.get(), crash_address_);
+}
+
+bool GwpAsanCrashData::CrashIsMine() const {
+  return is_gwp_asan_responsible_;
+}
+
+void GwpAsanCrashData::DumpCause(log_t* log) const {
+  if (!CrashIsMine()) {
+    ALOGE("Internal Error: DumpCause() on a non-GWP-ASan crash.");
+    return;
+  }
+
+  if (error_ == gwp_asan::Error::UNKNOWN) {
+    _LOG(log, logtype::HEADER, "Cause: [GWP-ASan]: Unknown error occurred at 0x%" PRIxPTR ".\n",
+         crash_address_);
+    return;
+  }
+
+  if (!responsible_allocation_) {
+    _LOG(log, logtype::HEADER, "Cause: [GWP-ASan]: %s at 0x%" PRIxPTR ".\n", error_string_,
+         crash_address_);
+    return;
+  }
+
+  uintptr_t alloc_address = __gwp_asan_get_allocation_address(responsible_allocation_);
+  size_t alloc_size = __gwp_asan_get_allocation_size(responsible_allocation_);
+
+  if (crash_address_ == alloc_address) {
+    // Use After Free on a 41-byte allocation at 0xdeadbeef.
+    _LOG(log, logtype::HEADER, "Cause: [GWP-ASan]: %s on a %zu-byte allocation at 0x%" PRIxPTR "\n",
+         error_string_, alloc_size, alloc_address);
+    return;
+  }
+
+  uintptr_t diff;
+  const char* location_str;
+
+  if (crash_address_ < alloc_address) {
+    // Buffer Underflow, 6 bytes left of a 41-byte allocation at 0xdeadbeef.
+    location_str = "left of";
+    diff = alloc_address - crash_address_;
+  } else if (crash_address_ - alloc_address < alloc_size) {
+    // Use After Free, 40 bytes into a 41-byte allocation at 0xdeadbeef.
+    location_str = "into";
+    diff = crash_address_ - alloc_address;
+  } else {
+    // Buffer Overflow, 6 bytes right of a 41-byte allocation at 0xdeadbeef, or
+    // Invalid Free, 47 bytes right of a 41-byte allocation at 0xdeadbeef.
+    location_str = "right of";
+    diff = crash_address_ - alloc_address;
+    if (error_ == gwp_asan::Error::BUFFER_OVERFLOW) {
+      diff -= alloc_size;
+    }
+  }
+
+  // Suffix of 'bytes', i.e. 4 bytes' vs. '1 byte'.
+  const char* byte_suffix = "s";
+  if (diff == 1) {
+    byte_suffix = "";
+  }
+  _LOG(log, logtype::HEADER,
+       "Cause: [GWP-ASan]: %s, %" PRIuPTR " byte%s %s a %zu-byte allocation at 0x%" PRIxPTR "\n",
+       error_string_, diff, byte_suffix, location_str, alloc_size, alloc_address);
+}
+
+// Build a frame for symbolization using the maps from the provided unwinder.
+// The constructed frame contains just enough information to be used to
+// symbolize a GWP-ASan stack trace.
+static unwindstack::FrameData BuildFrame(unwindstack::Unwinder* unwinder, uintptr_t pc,
+                                         size_t frame_num) {
+  unwindstack::FrameData frame;
+  frame.num = frame_num;
+
+  unwindstack::Maps* maps = unwinder->GetMaps();
+  unwindstack::MapInfo* map_info = maps->Find(pc);
+  if (!map_info) {
+    frame.rel_pc = pc;
+    return frame;
+  }
+
+  unwindstack::Elf* elf =
+      map_info->GetElf(unwinder->GetProcessMemory(), unwindstack::Regs::CurrentArch());
+
+  uint64_t relative_pc = elf->GetRelPc(pc, map_info);
+
+  // Create registers just to get PC adjustment. Doesn't matter what they point
+  // to.
+  unwindstack::Regs* regs = unwindstack::Regs::CreateFromLocal();
+  uint64_t pc_adjustment = regs->GetPcAdjustment(relative_pc, elf);
+  relative_pc -= pc_adjustment;
+  // The debug PC may be different if the PC comes from the JIT.
+  uint64_t debug_pc = relative_pc;
+
+  // If we don't have a valid ELF file, check the JIT.
+  if (!elf->valid()) {
+    unwindstack::JitDebug jit_debug(unwinder->GetProcessMemory());
+    uint64_t jit_pc = pc - pc_adjustment;
+    unwindstack::Elf* jit_elf = jit_debug.GetElf(maps, jit_pc);
+    if (jit_elf != nullptr) {
+      debug_pc = jit_pc;
+      elf = jit_elf;
+    }
+  }
+
+  // Copy all the things we need into the frame for symbolization.
+  frame.rel_pc = relative_pc;
+  frame.pc = pc - pc_adjustment;
+  frame.map_name = map_info->name;
+  frame.map_elf_start_offset = map_info->elf_start_offset;
+  frame.map_exact_offset = map_info->offset;
+  frame.map_start = map_info->start;
+  frame.map_end = map_info->end;
+  frame.map_flags = map_info->flags;
+  frame.map_load_bias = elf->GetLoadBias();
+
+  if (!elf->GetFunctionName(relative_pc, &frame.function_name, &frame.function_offset)) {
+    frame.function_name = "";
+    frame.function_offset = 0;
+  }
+  return frame;
+}
+
+constexpr size_t kMaxTraceLength = gwp_asan::AllocationMetadata::kMaxTraceLengthToCollect;
+
+bool GwpAsanCrashData::HasDeallocationTrace() const {
+  assert(CrashIsMine() && "HasDeallocationTrace(): Crash is not mine!");
+  if (!responsible_allocation_ || !__gwp_asan_is_deallocated(responsible_allocation_)) {
+    return false;
+  }
+  return true;
+}
+
+void GwpAsanCrashData::DumpDeallocationTrace(log_t* log, unwindstack::Unwinder* unwinder) const {
+  assert(HasDeallocationTrace() && "DumpDeallocationTrace(): No dealloc trace!");
+  uint64_t thread_id = __gwp_asan_get_deallocation_thread_id(responsible_allocation_);
+
+  std::unique_ptr<uintptr_t> frames(new uintptr_t[kMaxTraceLength]);
+  size_t num_frames =
+      __gwp_asan_get_deallocation_trace(responsible_allocation_, frames.get(), kMaxTraceLength);
+
+  if (thread_id == gwp_asan::kInvalidThreadID) {
+    _LOG(log, logtype::BACKTRACE, "\ndeallocated by thread <unknown>:\n");
+  } else {
+    _LOG(log, logtype::BACKTRACE, "\ndeallocated by thread %" PRIu64 ":\n", thread_id);
+  }
+
+  unwinder->SetDisplayBuildID(true);
+  for (size_t i = 0; i < num_frames; ++i) {
+    unwindstack::FrameData frame_data = BuildFrame(unwinder, frames.get()[i], i);
+    _LOG(log, logtype::BACKTRACE, "    %s\n", unwinder->FormatFrame(frame_data).c_str());
+  }
+}
+
+bool GwpAsanCrashData::HasAllocationTrace() const {
+  assert(CrashIsMine() && "HasAllocationTrace(): Crash is not mine!");
+  return responsible_allocation_ != nullptr;
+}
+
+void GwpAsanCrashData::DumpAllocationTrace(log_t* log, unwindstack::Unwinder* unwinder) const {
+  assert(HasAllocationTrace() && "DumpAllocationTrace(): No dealloc trace!");
+  uint64_t thread_id = __gwp_asan_get_allocation_thread_id(responsible_allocation_);
+
+  std::unique_ptr<uintptr_t> frames(new uintptr_t[kMaxTraceLength]);
+  size_t num_frames =
+      __gwp_asan_get_allocation_trace(responsible_allocation_, frames.get(), kMaxTraceLength);
+
+  if (thread_id == gwp_asan::kInvalidThreadID) {
+    _LOG(log, logtype::BACKTRACE, "\nallocated by thread <unknown>:\n");
+  } else {
+    _LOG(log, logtype::BACKTRACE, "\nallocated by thread %" PRIu64 ":\n", thread_id);
+  }
+
+  unwinder->SetDisplayBuildID(true);
+  for (size_t i = 0; i < num_frames; ++i) {
+    unwindstack::FrameData frame_data = BuildFrame(unwinder, frames.get()[i], i);
+    _LOG(log, logtype::BACKTRACE, "    %s\n", unwinder->FormatFrame(frame_data).c_str());
+  }
+}

debuggerd/libdebuggerd/include/libdebuggerd/gwp_asan.h

@@ -0,0 +1,95 @@
+/*
+ * Copyright (C) 2020 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.
+ */
+
+#pragma once
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include <log/log.h>
+#include <unwindstack/Memory.h>
+
+#include "gwp_asan/common.h"
+#include "types.h"
+#include "utility.h"
+
+class GwpAsanCrashData {
+ public:
+  GwpAsanCrashData() = delete;
+  ~GwpAsanCrashData() = default;
+
+  // Construct the crash data object. Takes a handle to the object that can
+  // supply the memory of the dead process, and pointers to the GWP-ASan state
+  // and metadata regions within that process. Also takes the thread information
+  // of the crashed process. If the process didn't crash via SEGV, GWP-ASan may
+  // still be responsible, as it terminates when it detects an internal error
+  // (double free, invalid free). In these cases, we will retrieve the fault
+  // address from the GWP-ASan allocator's state.
+  GwpAsanCrashData(unwindstack::Memory* process_memory, uintptr_t gwp_asan_state_ptr,
+                   uintptr_t gwp_asan_metadata_ptr, const ThreadInfo& thread_info);
+
+  // Is GWP-ASan responsible for this crash.
+  bool CrashIsMine() const;
+
+  // Returns the fault address. The fault address may be the same as provided
+  // during construction, or it may have been retrieved from GWP-ASan's internal
+  // allocator crash state.
+  uintptr_t GetFaultAddress() const;
+
+  // Dump the GWP-ASan stringified cause of this crash. May only be called if
+  // CrashIsMine() returns true.
+  void DumpCause(log_t* log) const;
+
+  // Returns whether this crash has a deallocation trace. May only be called if
+  // CrashIsMine() returns true.
+  bool HasDeallocationTrace() const;
+
+  // Dump the GWP-ASan deallocation trace for this crash. May only be called if
+  // HasDeallocationTrace() returns true.
+  void DumpDeallocationTrace(log_t* log, unwindstack::Unwinder* unwinder) const;
+
+  // Returns whether this crash has a allocation trace. May only be called if
+  // CrashIsMine() returns true.
+  bool HasAllocationTrace() const;
+
+  // Dump the GWP-ASan allocation trace for this crash. May only be called if
+  // HasAllocationTrace() returns true.
+  void DumpAllocationTrace(log_t* log, unwindstack::Unwinder* unwinder) const;
+
+ protected:
+  // Is GWP-ASan responsible for this crash.
+  bool is_gwp_asan_responsible_ = false;
+
+  // Thread ID of the crash.
+  size_t thread_id_;
+
+  // The type of error that GWP-ASan caused (and the stringified version),
+  // Undefined if GWP-ASan isn't responsible for the crash.
+  gwp_asan::Error error_;
+  const char* error_string_;
+
+  // Pointer to the crash address. Holds the internal crash address if it
+  // exists, otherwise the address provided at construction.
+  uintptr_t crash_address_ = 0u;
+
+  // Pointer to the metadata for the responsible allocation, nullptr if it
+  // doesn't exist.
+  const gwp_asan::AllocationMetadata* responsible_allocation_ = nullptr;
+
+  // Internal state.
+  gwp_asan::AllocatorState state_;
+  std::unique_ptr<const gwp_asan::AllocationMetadata> metadata_;
+};

debuggerd/libdebuggerd/include/libdebuggerd/tombstone.h

@@ -55,6 +55,7 @@ void engrave_tombstone_ucontext(int tombstone_fd, uint64_t abort_msg_address, si
 void engrave_tombstone(android::base::unique_fd output_fd, unwindstack::Unwinder* unwinder,
                        const std::map<pid_t, ThreadInfo>& thread_info, pid_t target_thread,
                        uint64_t abort_msg_address, OpenFilesList* open_files,
-                       std::string* amfd_data);
+                       std::string* amfd_data, uintptr_t gwp_asan_state,
+                       uintptr_t gwp_asan_metadata);
 
 #endif  // _DEBUGGERD_TOMBSTONE_H

debuggerd/libdebuggerd/test/tombstone_test.cpp

@@ -23,6 +23,7 @@
 
 #include <android-base/file.h>
 #include <android-base/properties.h>
+#include <gmock/gmock.h>
 #include <gtest/gtest.h>
 
 #include "libdebuggerd/utility.h"
@@ -31,8 +32,13 @@
 #include "host_signal_fixup.h"
 #include "log_fake.h"
 
+// Include tombstone.cpp to define log_tag before GWP-ASan includes log.
 #include "tombstone.cpp"
 
+#include "gwp_asan.cpp"
+
+using ::testing::MatchesRegex;
+
 class TombstoneTest : public ::testing::Test {
  protected:
   virtual void SetUp() {
@@ -359,3 +365,131 @@ TEST_F(TombstoneTest, dump_timestamp) {
   dump_timestamp(&log_, 0);
   ASSERT_STREQ("Timestamp: 1970-01-01 00:00:00+0000\n", amfd_data_.c_str());
 }
+
+class GwpAsanCrashDataTest : public GwpAsanCrashData {
+public:
+  GwpAsanCrashDataTest(
+      gwp_asan::Error error,
+      const gwp_asan::AllocationMetadata *responsible_allocation) :
+      GwpAsanCrashData(nullptr, 0u, 0u, ThreadInfo{}) {
+    is_gwp_asan_responsible_ = true;
+    error_ = error;
+    responsible_allocation_ = responsible_allocation;
+    error_string_ = gwp_asan::ErrorToString(error_);
+  }
+
+  void SetCrashAddress(uintptr_t crash_address) {
+    crash_address_ = crash_address;
+  }
+};
+
+TEST_F(TombstoneTest, gwp_asan_cause_uaf_exact) {
+  gwp_asan::AllocationMetadata meta;
+  meta.Addr = 0x1000;
+  meta.Size = 32;
+
+  GwpAsanCrashDataTest crash_data(gwp_asan::Error::USE_AFTER_FREE, &meta);
+  crash_data.SetCrashAddress(0x1000);
+
+  crash_data.DumpCause(&log_);
+  ASSERT_TRUE(lseek(log_.tfd, 0, SEEK_SET) == 0);
+  std::string tombstone_contents;
+  ASSERT_TRUE(android::base::ReadFdToString(log_.tfd, &tombstone_contents));
+  ASSERT_THAT(tombstone_contents,
+              MatchesRegex("Cause: \\[GWP-ASan\\]: Use After Free on a 32-byte "
+                           "allocation at 0x[a-fA-F0-9]+\n"));
+}
+
+TEST_F(TombstoneTest, gwp_asan_cause_double_free) {
+  gwp_asan::AllocationMetadata meta;
+  meta.Addr = 0x1000;
+  meta.Size = 32;
+
+  GwpAsanCrashDataTest crash_data(gwp_asan::Error::DOUBLE_FREE, &meta);
+  crash_data.SetCrashAddress(0x1000);
+
+  crash_data.DumpCause(&log_);
+  ASSERT_TRUE(lseek(log_.tfd, 0, SEEK_SET) == 0);
+  std::string tombstone_contents;
+  ASSERT_TRUE(android::base::ReadFdToString(log_.tfd, &tombstone_contents));
+  ASSERT_THAT(tombstone_contents,
+              MatchesRegex("Cause: \\[GWP-ASan\\]: Double Free on a 32-byte "
+                           "allocation at 0x[a-fA-F0-9]+\n"));
+}
+
+TEST_F(TombstoneTest, gwp_asan_cause_overflow) {
+  gwp_asan::AllocationMetadata meta;
+  meta.Addr = 0x1000;
+  meta.Size = 32;
+
+  GwpAsanCrashDataTest crash_data(gwp_asan::Error::BUFFER_OVERFLOW, &meta);
+  crash_data.SetCrashAddress(0x1025);
+
+  crash_data.DumpCause(&log_);
+  ASSERT_TRUE(lseek(log_.tfd, 0, SEEK_SET) == 0);
+  std::string tombstone_contents;
+  ASSERT_TRUE(android::base::ReadFdToString(log_.tfd, &tombstone_contents));
+  ASSERT_THAT(
+      tombstone_contents,
+      MatchesRegex(
+          "Cause: \\[GWP-ASan\\]: Buffer Overflow, 5 bytes right of a 32-byte "
+          "allocation at 0x[a-fA-F0-9]+\n"));
+}
+
+TEST_F(TombstoneTest, gwp_asan_cause_underflow) {
+  gwp_asan::AllocationMetadata meta;
+  meta.Addr = 0x1000;
+  meta.Size = 32;
+
+  GwpAsanCrashDataTest crash_data(gwp_asan::Error::BUFFER_UNDERFLOW, &meta);
+  crash_data.SetCrashAddress(0xffe);
+
+  crash_data.DumpCause(&log_);
+  ASSERT_TRUE(lseek(log_.tfd, 0, SEEK_SET) == 0);
+  std::string tombstone_contents;
+  ASSERT_TRUE(android::base::ReadFdToString(log_.tfd, &tombstone_contents));
+  ASSERT_THAT(
+      tombstone_contents,
+      MatchesRegex(
+          "Cause: \\[GWP-ASan\\]: Buffer Underflow, 2 bytes left of a 32-byte "
+          "allocation at 0x[a-fA-F0-9]+\n"));
+}
+
+TEST_F(TombstoneTest, gwp_asan_cause_invalid_free_inside) {
+  gwp_asan::AllocationMetadata meta;
+  meta.Addr = 0x1000;
+  meta.Size = 32;
+
+  GwpAsanCrashDataTest crash_data(gwp_asan::Error::INVALID_FREE, &meta);
+  crash_data.SetCrashAddress(0x1001);
+
+  crash_data.DumpCause(&log_);
+  ASSERT_TRUE(lseek(log_.tfd, 0, SEEK_SET) == 0);
+  std::string tombstone_contents;
+  ASSERT_TRUE(android::base::ReadFdToString(log_.tfd, &tombstone_contents));
+  ASSERT_THAT(
+      tombstone_contents,
+      MatchesRegex(
+          "Cause: \\[GWP-ASan\\]: Invalid \\(Wild\\) Free, 1 byte into a 32-byte "
+          "allocation at 0x[a-fA-F0-9]+\n"));
+}
+
+TEST_F(TombstoneTest, gwp_asan_cause_invalid_free_outside) {
+  gwp_asan::AllocationMetadata meta;
+  meta.Addr = 0x1000;
+  meta.Size = 32;
+
+  GwpAsanCrashDataTest crash_data(gwp_asan::Error::INVALID_FREE, &meta);
+  crash_data.SetCrashAddress(0x1021);
+
+  crash_data.DumpCause(&log_);
+  ASSERT_TRUE(lseek(log_.tfd, 0, SEEK_SET) == 0);
+  std::string tombstone_contents;
+  ASSERT_TRUE(android::base::ReadFdToString(log_.tfd, &tombstone_contents));
+  ASSERT_THAT(
+      tombstone_contents,
+      MatchesRegex(
+          "Cause: \\[GWP-ASan\\]: Invalid \\(Wild\\) Free, 33 bytes right of a 32-byte "
+          "allocation at 0x[a-fA-F0-9]+\n"));
+}
+

debuggerd/libdebuggerd/tombstone.cpp

@@ -53,9 +53,13 @@
 #include <unwindstack/Unwinder.h>
 
 #include "libdebuggerd/backtrace.h"
+#include "libdebuggerd/gwp_asan.h"
 #include "libdebuggerd/open_files_list.h"
 #include "libdebuggerd/utility.h"
 
+#include "gwp_asan/common.h"
+#include "gwp_asan/crash_handler.h"
+
 using android::base::GetBoolProperty;
 using android::base::GetProperty;
 using android::base::StringPrintf;
@@ -372,7 +376,8 @@ void dump_memory_and_code(log_t* log, unwindstack::Maps* maps, unwindstack::Memo
 }
 
 static bool dump_thread(log_t* log, unwindstack::Unwinder* unwinder, const ThreadInfo& thread_info,
-                        uint64_t abort_msg_address, bool primary_thread) {
+                        uint64_t abort_msg_address, bool primary_thread,
+                        const GwpAsanCrashData& gwp_asan_crash_data) {
   log->current_tid = thread_info.tid;
   if (!primary_thread) {
     _LOG(log, logtype::THREAD, "--- --- --- --- --- --- --- --- --- --- --- --- --- --- --- ---\n");
@@ -381,7 +386,13 @@ static bool dump_thread(log_t* log, unwindstack::Unwinder* unwinder, const Threa
 
   if (thread_info.siginfo) {
     dump_signal_info(log, thread_info, unwinder->GetProcessMemory().get());
-    dump_probable_cause(log, thread_info.siginfo, unwinder->GetMaps(), thread_info.registers.get());
+  }
+
+  if (primary_thread && gwp_asan_crash_data.CrashIsMine()) {
+    gwp_asan_crash_data.DumpCause(log);
+  } else if (thread_info.siginfo) {
+    dump_probable_cause(log, thread_info.siginfo, unwinder->GetMaps(),
+                        thread_info.registers.get());
   }
 
   if (primary_thread) {
@@ -402,6 +413,14 @@ static bool dump_thread(log_t* log, unwindstack::Unwinder* unwinder, const Threa
   }
 
   if (primary_thread) {
+    if (gwp_asan_crash_data.HasDeallocationTrace()) {
+      gwp_asan_crash_data.DumpDeallocationTrace(log, unwinder);
+    }
+
+    if (gwp_asan_crash_data.HasAllocationTrace()) {
+      gwp_asan_crash_data.DumpAllocationTrace(log, unwinder);
+    }
+
     unwindstack::Maps* maps = unwinder->GetMaps();
     dump_memory_and_code(log, maps, unwinder->GetProcessMemory().get(),
                          thread_info.registers.get());
@@ -583,13 +602,14 @@ void engrave_tombstone_ucontext(int tombstone_fd, uint64_t abort_msg_address, si
   }
 
   engrave_tombstone(unique_fd(dup(tombstone_fd)), &unwinder, threads, tid, abort_msg_address,
-                    nullptr, nullptr);
+                    nullptr, nullptr, 0u, 0u);
 }
 
 void engrave_tombstone(unique_fd output_fd, unwindstack::Unwinder* unwinder,
                        const std::map<pid_t, ThreadInfo>& threads, pid_t target_thread,
                        uint64_t abort_msg_address, OpenFilesList* open_files,
-                       std::string* amfd_data) {
+                       std::string* amfd_data, uintptr_t gwp_asan_state_ptr,
+                       uintptr_t gwp_asan_metadata_ptr) {
   // don't copy log messages to tombstone unless this is a dev device
   bool want_logs = android::base::GetBoolProperty("ro.debuggable", false);
 
@@ -607,7 +627,13 @@ void engrave_tombstone(unique_fd output_fd, unwindstack::Unwinder* unwinder,
   if (it == threads.end()) {
     LOG(FATAL) << "failed to find target thread";
   }
-  dump_thread(&log, unwinder, it->second, abort_msg_address, true);
+
+  GwpAsanCrashData gwp_asan_crash_data(unwinder->GetProcessMemory().get(),
+                                       gwp_asan_state_ptr,
+                                       gwp_asan_metadata_ptr, it->second);
+
+  dump_thread(&log, unwinder, it->second, abort_msg_address, true,
+              gwp_asan_crash_data);
 
   if (want_logs) {
     dump_logs(&log, it->second.pid, 50);
@@ -618,7 +644,7 @@ void engrave_tombstone(unique_fd output_fd, unwindstack::Unwinder* unwinder,
       continue;
     }
 
-    dump_thread(&log, unwinder, thread_info, 0, false);
+    dump_thread(&log, unwinder, thread_info, 0, false, gwp_asan_crash_data);
   }
 
   if (open_files) {

debuggerd/protocol.h

@@ -95,10 +95,16 @@ struct __attribute__((__packed__)) CrashInfoDataV2 : public CrashInfoDataV1 {
   uintptr_t fdsan_table_address;
 };
 
+struct __attribute__((__packed__)) CrashInfoDataV3 : public CrashInfoDataV2 {
+  uintptr_t gwp_asan_state;
+  uintptr_t gwp_asan_metadata;
+};
+
 struct __attribute__((__packed__)) CrashInfo {
   CrashInfoHeader header;
   union {
     CrashInfoDataV1 v1;
     CrashInfoDataV2 v2;
+    CrashInfoDataV3 v3;
   } data;
 };