| // Copyright 2016 the V8 project authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef V8_TRAP_HANDLER_H_ |
| #define V8_TRAP_HANDLER_H_ |
| |
| #include <signal.h> |
| #include <stdint.h> |
| #include <stdlib.h> |
| |
| #include "src/base/build_config.h" |
| #include "src/flags.h" |
| #include "src/globals.h" |
| |
| #if V8_OS_LINUX |
| #include <ucontext.h> |
| #endif |
| |
| namespace v8 { |
| namespace internal { |
| namespace trap_handler { |
| |
| // TODO(eholk): Support trap handlers on other platforms. |
| #if V8_TARGET_ARCH_X64 && V8_OS_LINUX && !V8_OS_ANDROID |
| #define V8_TRAP_HANDLER_SUPPORTED 1 |
| #else |
| #define V8_TRAP_HANDLER_SUPPORTED 0 |
| #endif |
| |
| struct ProtectedInstructionData { |
| // The offset of this instruction from the start of its code object. |
| // Wasm code never grows larger than 2GB, so uint32_t is sufficient. |
| uint32_t instr_offset; |
| |
| // The offset of the landing pad from the start of its code object. |
| // |
| // TODO(eholk): Using a single landing pad and store parameters here. |
| uint32_t landing_offset; |
| }; |
| |
| const int kInvalidIndex = -1; |
| |
| /// Adjusts the base code pointer. |
| void UpdateHandlerDataCodePointer(int index, void* base); |
| |
| /// Adds the handler data to the place where the signal handler will find it. |
| /// |
| /// This returns a number that can be used to identify the handler data to |
| /// UpdateHandlerDataCodePointer and ReleaseHandlerData, or -1 on failure. |
| int RegisterHandlerData(void* base, size_t size, |
| size_t num_protected_instructions, |
| const ProtectedInstructionData* protected_instructions); |
| |
| /// Removes the data from the master list and frees any memory, if necessary. |
| /// TODO(mtrofin): once FLAG_wasm_jit_to_native is not needed, we can switch |
| /// to using size_t for index and not need kInvalidIndex. |
| void ReleaseHandlerData(int index); |
| |
| #if V8_OS_WIN |
| #define THREAD_LOCAL __declspec(thread) |
| #elif V8_OS_ANDROID |
| // TODO(eholk): fix this before enabling for trap handlers for Android. |
| #define THREAD_LOCAL |
| #else |
| #define THREAD_LOCAL __thread |
| #endif |
| |
| inline bool IsTrapHandlerEnabled() { |
| return FLAG_wasm_trap_handler && V8_TRAP_HANDLER_SUPPORTED; |
| } |
| |
| extern THREAD_LOCAL int g_thread_in_wasm_code; |
| |
| inline bool IsThreadInWasm() { return g_thread_in_wasm_code; } |
| |
| inline void SetThreadInWasm() { |
| if (IsTrapHandlerEnabled()) { |
| DCHECK(!IsThreadInWasm()); |
| g_thread_in_wasm_code = true; |
| } |
| } |
| |
| inline void ClearThreadInWasm() { |
| if (IsTrapHandlerEnabled()) { |
| DCHECK(IsThreadInWasm()); |
| g_thread_in_wasm_code = false; |
| } |
| } |
| |
| bool RegisterDefaultSignalHandler(); |
| V8_EXPORT_PRIVATE void RestoreOriginalSignalHandler(); |
| |
| #if V8_OS_LINUX |
| bool TryHandleSignal(int signum, siginfo_t* info, ucontext_t* context); |
| #endif // V8_OS_LINUX |
| |
| size_t GetRecoveredTrapCount(); |
| |
| } // namespace trap_handler |
| } // namespace internal |
| } // namespace v8 |
| |
| #endif // V8_TRAP_HANDLER_H_ |