Lightemerald/windows-user-space-emulator
2
0
Fork 0
mirror of https://github.com/momo5502/emulator.git synced 2026-01-24 06:01:02 +00:00
Code Issues Packages Projects Releases Wiki Activity

Implement guard pages (#406)

Browse Source 
Hey, looking for feedback on my guard page implementation. 

I wasn't sure on how to structure the additional windows specific memory
flags, since the emulation backends won't like additional guard flag. I
opted to create a new `memory_permission_ext` enum to hold the guard
flag, and a `nt_memory_permission` struct to wrap the "common" memory
permission flags, with the new extended flags. This struct implicitly
coerces to the original `memory_permission` to reduce the amount of
changes for the PR.

This however meant that I changed signatures of `map_memory` and
`apply_memory_protection` in `memory_interface` to accommodate this new
structure, and was an afterthought.

The `map_nt_to_emulator_protection` function might also need some
attention now, too. For future reference, windows uses
[MiMakeProtectionMask](https://doxygen.reactos.org/d1/d9a/marea_8c.html#adfb66408771a4df77c1056cc2a99ef21)
in ntoskrnl to map `PAGE_*` flags to [MM PTE
constants](https://reactos.org/wiki/Techwiki:Memory_management_in_the_Windows_XP_kernel).

The test added to the `test-sample` binary seems to be passing.

Fixes #21
This commit is contained in:
Maurice Heumann
2025-07-17 17:41:06 +02:00
committed by GitHub
parent b34adbadbf 188b95af5d
commit 9e5a6b509b
13 changed files with 359 additions and 34 deletions
Download Patch File Download Diff File Expand all files Collapse all files

17
src/windows-emulator/windows_emulator.cpp
View File

@@ -11,6 +11,7 @@
#include "apiset/apiset.hpp"
#include "network/static_socket_factory.hpp"
#include "memory_permission_ext.hpp"
constexpr auto MAX_INSTRUCTIONS_PER_TIME_SLICE = 0x20000;
@@ -501,8 +502,20 @@ void windows_emulator::setup_hooks()
this->emu().hook_memory_violation([&](const uint64_t address, const size_t size, const memory_operation operation,
const memory_violation_type type) {
this->callbacks.on_memory_violate(address, size, operation, type);
dispatch_access_violation(this->emu(), this->process, address, operation);
auto region = this->memory.get_region_info(address);
if (region.permissions.is_guarded())
{
// Unset the GUARD_PAGE flag and dispatch a STATUS_GUARD_PAGE_VIOLATION
this->memory.protect_memory(region.allocation_base, region.length,
region.permissions & ~memory_permission_ext::guard);
dispatch_guard_page_violation(this->emu(), this->process, address, operation);
}
else
{
this->callbacks.on_memory_violate(address, size, operation, type);
dispatch_access_violation(this->emu(), this->process, address, operation);
}
return memory_violation_continuation::resume;
});