What is INT 0x29 (29h, 41) on Windows x86-64?

Question

What does this x86-64 assembly code do? What is interrupt 41?

MOV ECX, 0x7
INT 0x29

Answer 1

https://learn.microsoft.com/en-us/cpp/intrinsics/fastfail?view=msvc-170 says:

Internally, __fastfail is implemented by using several architecture-specific mechanisms:

Architecture	Instruction	Location of code argument
x86	int 0x29	ecx
x64	int 0x29	rcx
ARM	Opcode 0xDEFB	r0
ARM64	Opcode 0xF003	x0

https://www.softwareverify.com/blog/fail-fast-codes/ says that 7 is FAST_FAIL_FATAL_APP_EXIT.

Related: Find out what's calling __fastfail