mirror of
https://github.com/fluencelabs/wasmer
synced 2024-12-15 15:15:40 +00:00
87 lines
2.8 KiB
C
87 lines
2.8 KiB
C
#include <windows.h>
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#include <setjmp.h>
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#include "exception_handling.h"
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#define CALL_FIRST 1
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__declspec(thread) jmp_buf jmpBuf;
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__declspec(thread) PVOID caughtExceptionAddress;
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__declspec(thread) DWORD64 caughtInstructionPointer;
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__declspec(thread) PVOID savedStackPointer;
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__declspec(thread) BOOL exceptionHandlerInstalled = FALSE;
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__declspec(thread) BOOL alreadyHandlingException = FALSE;
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__declspec(thread) PVOID handle;
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void longjmpOutOfHere() {
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longjmp(jmpBuf, 1);
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}
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/// Get the current address that we use to jmp, the no inline is important
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static __declspec(noinline) void *get_callee_frame_address(void) {
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return _AddressOfReturnAddress();
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}
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static LONG WINAPI
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exceptionHandler(struct _EXCEPTION_POINTERS *ExceptionInfo) {
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EXCEPTION_RECORD* pExceptionRecord = ExceptionInfo->ExceptionRecord;
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PCONTEXT pCONTEXT = ExceptionInfo->ContextRecord;
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caughtExceptionAddress = pExceptionRecord->ExceptionAddress;
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caughtInstructionPointer = pCONTEXT->Rip;
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if (alreadyHandlingException == TRUE) {
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return EXCEPTION_CONTINUE_SEARCH;
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}
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alreadyHandlingException = TRUE;
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// Basically, here, we coerce the os to resume us into a context that calls `longjmp` instead of just continuing.
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// Presumably, we cannot `longjmp` out of the signal/exception context, like we can on unix.
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pCONTEXT->Rip = (uintptr_t)(&longjmpOutOfHere);
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pCONTEXT->Rsp = (uintptr_t)(savedStackPointer);
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return EXCEPTION_CONTINUE_EXECUTION;
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}
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static void removeExceptionHandler() {
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if (exceptionHandlerInstalled == FALSE) {
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return;
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}
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RemoveVectoredExceptionHandler(handle);
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exceptionHandlerInstalled = FALSE;
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}
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uint8_t callProtected(trampoline_t trampoline,
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const struct wasmer_instance_context_t* ctx,
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const struct func_t* func,
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const uint64_t* param_vec,
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uint64_t* return_vec,
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struct call_protected_result_t* out_result) {
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// install exception handler
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if (exceptionHandlerInstalled == FALSE) {
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exceptionHandlerInstalled = TRUE;
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handle = AddVectoredExceptionHandler(CALL_FIRST, exceptionHandler);
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}
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// jmp jmp jmp!
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int signum = setjmp(jmpBuf);
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if (signum == 0) {
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// save the stack pointer
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savedStackPointer = get_callee_frame_address();
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trampoline(ctx, func, param_vec, return_vec);
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out_result->code = 0;
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out_result->exception_address = 0;
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out_result->instruction_pointer = 0;
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removeExceptionHandler();
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return TRUE;
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}
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out_result->code = (uint64_t)signum;
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out_result->exception_address = (uint64_t)caughtExceptionAddress;
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out_result->instruction_pointer = caughtInstructionPointer;
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caughtExceptionAddress = 0;
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caughtInstructionPointer = 0;
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removeExceptionHandler();
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return FALSE;
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}
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