__forceinline
void
__except_validate_jump_buffer_common (
_In_ jmp_buf JumpBuffer,
_In_ PVOID (*ExceptGetJbSpRoutine)(jmp_buf)
)
/*++
Routine Description:
This function validates a jump buffer for exception handling support.
Arguments:
JumpBuffer - Supplies a pointer to the jump buffer to validate.
Return Value:
None. If the jump buffer was not valid, a fast fail event is raised if
CFG was enforced.
--*/
{
PVOID StackPointer;
PNT_TIB Tib;
//
// If guard ICall checks are enforced, then validate the stack extents of
// the jump buffer and raise a fast fail exception if the extents are
// invalid. If checks are not enforced or the jump buffer was valid, then
// return.
//
if (_guard_icall_checks_enforced()) {
Tib = (PNT_TIB)NtCurrentTeb();
#pragma prefast(suppress:26007, "JumpBuffer is really a _JUMP_BUFFER in disguise and not a jmp_buf. The code is correct.")
StackPointer = ExceptGetJbSpRoutine(JumpBuffer);
if ((StackPointer < Tib->StackLimit) ||
(StackPointer > Tib->StackBase)) {
__fastfail(FAST_FAIL_INVALID_SET_OF_CONTEXT);
}
#if defined(JB_FRAME)
if (JB_FRAME(JumpBuffer) == 0) {
__fastfail(FAST_FAIL_INVALID_SET_OF_CONTEXT);
}
#endif
}
}
void __cdecl abort (
void
)
{
_PHNDLR sigabrt_act = SIG_DFL;
#ifdef _DEBUG
if (__abort_behavior & _WRITE_ABORT_MSG)
{
/* write the abort message */
_NMSG_WRITE(_RT_ABORT);
}
#endif /* _DEBUG */
/* Check if the user installed a handler for SIGABRT.
* We need to read the user handler atomically in the case
* another thread is aborting while we change the signal
* handler.
*/
sigabrt_act = __get_sigabrt();
if (sigabrt_act != SIG_DFL)
{
raise(SIGABRT);
}
/* If there is no user handler for SIGABRT or if the user
* handler returns, then exit from the program anyway
*/
if (__abort_behavior & _CALL_REPORTFAULT)
{
#if defined (_M_ARM) || defined (_CRT_APP)
__fastfail(FAST_FAIL_FATAL_APP_EXIT);
#else /* defined (_M_ARM) || defined (_CRT_APP) */
if (IsProcessorFeaturePresent(PF_FASTFAIL_AVAILABLE))
__fastfail(FAST_FAIL_FATAL_APP_EXIT);
_call_reportfault(_CRT_DEBUGGER_ABORT, STATUS_FATAL_APP_EXIT, EXCEPTION_NONCONTINUABLE);
#endif /* defined (_M_ARM) || defined (_CRT_APP) */
}
/* If we don't want to call ReportFault, then we call _exit(3), which is the
* same as invoking the default handler for SIGABRT
*/
_exit(3);
}
void
__except_validate_context_record (
_In_ PCONTEXT ContextRecord
)
/*++
Routine Description:
This function validates a context record for exception handling support.
Arguments:
ContextRecord - Supplies a pointer to the context record to validate.
Return Value:
None. If the context record was not valid, a fast fail event is raised if
CFG was enforced.
--*/
{
PVOID StackPointer;
PNT_TIB Tib;
//
// If guard ICall checks are enforced, then validate the stack extents of
// the context record and raise a fast fail exception if the extents are
// invalid. If checks are not enforced or the jump buffer was valid, then
// return.
//
if (_guard_icall_checks_enforced()) {
Tib = (PNT_TIB)NtCurrentTeb();
//
// HYB-TODO: Validate both chpe and guest context.
//
StackPointer = (PVOID)CONTEXT_TO_STACK_POINTER(ContextRecord);
if ((StackPointer < Tib->StackLimit) ||
(StackPointer > Tib->StackBase)) {
__fastfail(FAST_FAIL_INVALID_SET_OF_CONTEXT);
}
}
}
void EbrThrowFatal(int code, const char* msg, ...) {
printf("FATAL: %s\n", msg);
__fastfail(code);
}
__declspec(noreturn) void __cdecl __report_gsfailure(GSFAILURE_PARAMETER)
{
if (IsProcessorFeaturePresent(PF_FASTFAIL_AVAILABLE))
{
__fastfail(FAST_FAIL_STACK_COOKIE_CHECK_FAILURE);
}
volatile UINT_PTR cookie[2];
// Set up a fake exception, and report it via UnhandledExceptionFilter.
// We can't raise a true exception because the stack (and therefore
// exception handling) can't be trusted after a buffer overrun. The
// exception should appear as if it originated after the call to
// __security_check_cookie, so it is attributed to the function where the
// buffer overrun was detected.
#if defined _M_IX86
// On x86, we reserve some extra stack which won't be used. That is to
// preserve as much of the call frame as possible when the function with
// the buffer overrun entered __security_check_cookie with a JMP instead of
// a CALL, after the calling frame has been released in the epilogue of
// that function.
ULONG volatile dw[(sizeof(CONTEXT) + sizeof(EXCEPTION_RECORD)) / sizeof(ULONG)];
// Save the state in the context record immediately. Hopefully, since
// opts are disabled, this will happen without modifying ECX, which has
// the local cookie which failed the check.
__asm
{
mov dword ptr [GS_ContextRecord.Eax ], eax
mov dword ptr [GS_ContextRecord.Ecx ], ecx
mov dword ptr [GS_ContextRecord.Edx ], edx
mov dword ptr [GS_ContextRecord.Ebx ], ebx
mov dword ptr [GS_ContextRecord.Esi ], esi
mov dword ptr [GS_ContextRecord.Edi ], edi
mov word ptr [GS_ContextRecord.SegSs], ss
mov word ptr [GS_ContextRecord.SegCs], cs
mov word ptr [GS_ContextRecord.SegDs], ds
mov word ptr [GS_ContextRecord.SegEs], es
mov word ptr [GS_ContextRecord.SegFs], fs
mov word ptr [GS_ContextRecord.SegGs], gs
pushfd
pop [GS_ContextRecord.EFlags]
// Set the context EBP/EIP/ESP to the values which would be found
// in the caller to __security_check_cookie.
mov eax, [ebp]
mov dword ptr [GS_ContextRecord.Ebp], eax
mov eax, [ebp+4]
mov dword ptr [GS_ContextRecord.Eip], eax
lea eax, [ebp+8]
mov dword ptr [GS_ContextRecord.Esp], eax
// Make sure the dummy stack space looks referenced.
mov eax, dword ptr dw
}
GS_ContextRecord.ContextFlags = CONTEXT_CONTROL;
GS_ExceptionRecord.ExceptionAddress = (PVOID)(ULONG_PTR)GS_ContextRecord.Eip;
#else // ^^^ _M_IX86 ^^^ // vvv _M_X64 vvv //
capture_previous_context(&GS_ContextRecord);
GS_ContextRecord.Rip = (ULONGLONG)_ReturnAddress();
GS_ContextRecord.Rsp = (ULONGLONG)_AddressOfReturnAddress()+8;
GS_ExceptionRecord.ExceptionAddress = (PVOID)GS_ContextRecord.Rip;
GS_ContextRecord.Rcx = stack_cookie;
#endif // _M_X64
GS_ExceptionRecord.ExceptionCode = STATUS_SECURITY_CHECK_FAILURE;
GS_ExceptionRecord.ExceptionFlags = EXCEPTION_NONCONTINUABLE;
GS_ExceptionRecord.NumberParameters = 1;
GS_ExceptionRecord.ExceptionInformation[0] = FAST_FAIL_STACK_COOKIE_CHECK_FAILURE;
// Save the global cookie and cookie complement locally - using an array
// to defeat any potential stack-packing.
cookie[0] = __security_cookie;
cookie[1] = __security_cookie_complement;
// Raise the security failure by passing it to the unhandled exception
// filter and then terminate the process.
__raise_securityfailure((EXCEPTION_POINTERS*)&GS_ExceptionPointers);
}
__declspec(noreturn) void __cdecl __report_gsfailure(GSFAILURE_PARAMETER)
{
__fastfail(FAST_FAIL_STACK_COOKIE_CHECK_FAILURE);
}
