Failure with 0 aslr_slide

[liamwhite]

This code does not work when ASLR is disabled or you hit the 1/260000 lottery of selecting a 0 ASLR slide value:

skyline/source/skyline/inlinehook/And64InlineHook.cpp

Lines 536 to 552 in 972cdef

	// search for applicable space for inline hook JIT
	auto cur_searching_addr =
	skyline::utils::g_MainTextAddr - inline_hook_pool_size; // start searching from right before .text
	MemoryInfo mem;
	while (true) {
	u32 page_info;
	if (R_SUCCEEDED(svcQueryMemory(&mem, &page_info, cur_searching_addr)) && mem.type == MemType_Unmapped &&
	mem.size >= ALIGN_UP(inline_hook_pool_size, PAGE_SIZE)) {
	break;
	}
	cur_searching_addr -= PAGE_SIZE;
	}
	// allocate inline hook JIT
	rc = jitCreate(&__inline_hook_jit, (void*)ALIGN_DOWN(mem.addr + mem.size - inline_hook_pool_size, PAGE_SIZE),
	inline_hook_pool_size);

The code assumes addresses before the first .text section can be mapped as generated code. But if the ASLR slide is 0, then they are not mappable as generated code, and the program will fail to perform the call to svc::ControlCodeMemory and subsequently crash.

[jam1garner]

I personally believe unlucky people should not be allowed to use Skyline