You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

480 lines
12 KiB

#include "mem_ctx.hpp"
namespace nasa
{
mem_ctx::mem_ctx(vdm::vdm_ctx& v_ctx, std::uint32_t pid)
:
v_ctx(&v_ctx),
pid(pid),
dirbase(get_dirbase(v_ctx, pid))
{
// find an empty pml4e inside of current processes pml4...
const auto current_pml4 =
v_ctx.get_virtual(reinterpret_cast<std::uintptr_t>(
get_dirbase(v_ctx, GetCurrentProcessId())));
for (auto idx = 100u; idx > 0u; --idx)
if (!v_ctx.rkm<pml4e>(current_pml4 + (idx * sizeof pml4e)).value)
this->pml4e_index = idx;
// allocate a pdpt
this->new_pdpt.second =
reinterpret_cast<ppdpte>(
VirtualAlloc(
NULL,
PAGE_4KB,
MEM_COMMIT | MEM_RESERVE,
PAGE_READWRITE
));
PAGE_IN(this->new_pdpt.second, PAGE_4KB);
// get page table entries for new pdpt
pt_entries new_pdpt_entries;
hyperspace_entries(new_pdpt_entries, new_pdpt.second);
this->new_pdpt.first = reinterpret_cast<ppdpte>(new_pdpt_entries.pt.second.pfn << 12);
// make a new pml4e that points to our new pdpt.
new_pdpt_entries.pml4.second.pfn = new_pdpt_entries.pt.second.pfn;
// set the pml4e to point to the new pdpt
set_pml4e(reinterpret_cast<::ppml4e>(get_dirbase()) + this->pml4e_index, new_pdpt_entries.pml4.second, true);
// make a new pd
this->new_pd.second =
reinterpret_cast<ppde>(
VirtualAlloc(
NULL,
PAGE_4KB,
MEM_COMMIT | MEM_RESERVE,
PAGE_READWRITE
));
PAGE_IN(this->new_pd.second, PAGE_4KB);
// get paging table entries for pd
pt_entries new_pd_entries;
hyperspace_entries(new_pd_entries, this->new_pd.second);
this->new_pd.first = reinterpret_cast<ppde>(new_pd_entries.pt.second.pfn << 12);
// make a new pt
this->new_pt.second =
reinterpret_cast<ppte>(
VirtualAlloc(
NULL,
PAGE_4KB,
MEM_COMMIT | MEM_RESERVE,
PAGE_READWRITE
));
PAGE_IN(this->new_pt.second, PAGE_4KB);
// get paging table entries for pt
pt_entries new_pt_entries;
hyperspace_entries(new_pt_entries, this->new_pt.second);
this->new_pt.first = reinterpret_cast<ppte>(new_pt_entries.pt.second.pfn << 12);
}
void* mem_ctx::set_page(void* addr)
{
// table entry change.
++pte_index;
if (pte_index >= 511)
{
++pde_index;
pte_index = 0;
}
if (pde_index >= 511)
{
++pdpte_index;
pde_index = 0;
}
if (pdpte_index >= 511)
pdpte_index = 0;
pdpte new_pdpte = { NULL };
new_pdpte.present = true;
new_pdpte.rw = true;
new_pdpte.pfn = reinterpret_cast<std::uintptr_t>(new_pd.first) >> 12;
new_pdpte.user_supervisor = true;
new_pdpte.accessed = true;
// set pdpte entry
*reinterpret_cast<pdpte*>(new_pdpt.second + pdpte_index) = new_pdpte;
pde new_pde = { NULL };
new_pde.present = true;
new_pde.rw = true;
new_pde.pfn = reinterpret_cast<std::uintptr_t>(new_pt.first) >> 12;
new_pde.user_supervisor = true;
new_pde.accessed = true;
// set pde entry
*reinterpret_cast<pde*>(new_pd.second + pde_index) = new_pde;
pte new_pte = { NULL };
new_pte.present = true;
new_pte.rw = true;
new_pte.pfn = reinterpret_cast<std::uintptr_t>(addr) >> 12;
new_pte.user_supervisor = true;
new_pte.accessed = true;
// set pte entry
*reinterpret_cast<pte*>(new_pt.second + pte_index) = new_pte;
// set page offset
this->page_offset = virt_addr_t{ addr }.offset;
return get_page();
}
void* mem_ctx::get_page() const
{
// builds a new address given the state of all table indexes
virt_addr_t new_addr;
new_addr.pml4_index = this->pml4e_index;
new_addr.pdpt_index = this->pdpte_index;
new_addr.pd_index = this->pde_index;
new_addr.pt_index = this->pte_index;
new_addr.offset = this->page_offset;
return new_addr.value;
}
void* mem_ctx::get_dirbase(vdm::vdm_ctx& v_ctx, std::uint32_t pid)
{
const auto peproc =
reinterpret_cast<std::uint64_t>(v_ctx.get_peprocess(pid));
const auto dirbase =
v_ctx.rkm<pte>(peproc + 0x28);
return reinterpret_cast<void*>(dirbase.pfn << 12);
}
bool mem_ctx::hyperspace_entries(pt_entries& entries, void* addr)
{
if (!addr || !dirbase)
return false;
virt_addr_t virt_addr{ addr };
entries.pml4.first = reinterpret_cast<ppml4e>(dirbase) + virt_addr.pml4_index;
entries.pml4.second = v_ctx->rkm<pml4e>(
v_ctx->get_virtual(reinterpret_cast<std::uintptr_t>(entries.pml4.first)));
if (!entries.pml4.second.value)
return false;
entries.pdpt.first = reinterpret_cast<ppdpte>(entries.pml4.second.pfn << 12) + virt_addr.pdpt_index;
entries.pdpt.second = v_ctx->rkm<pdpte>(
v_ctx->get_virtual(reinterpret_cast<std::uintptr_t>(entries.pdpt.first)));
if (!entries.pdpt.second.value)
return false;
entries.pd.first = reinterpret_cast<ppde>(entries.pdpt.second.pfn << 12) + virt_addr.pd_index;
entries.pd.second = v_ctx->rkm<pde>(
v_ctx->get_virtual(reinterpret_cast<std::uintptr_t>(entries.pd.first)));
// if its a 2mb page
if (entries.pd.second.large_page)
{
entries.pt.second.value = entries.pd.second.value;
entries.pt.first = reinterpret_cast<ppte>(entries.pd.second.value);
return true;
}
entries.pt.first = reinterpret_cast<ppte>(entries.pd.second.pfn << 12) + virt_addr.pt_index;
entries.pt.second = v_ctx->rkm<pte>(
v_ctx->get_virtual(reinterpret_cast<std::uintptr_t>(entries.pt.first)));
if (!entries.pt.second.value)
return false;
return true;
}
std::pair<ppte, pte> mem_ctx::get_pte(void* addr, bool use_hyperspace)
{
if (!dirbase || !addr)
return {};
pt_entries entries;
if ((use_hyperspace ? hyperspace_entries(entries, addr) : (bool)virt_to_phys(entries, addr)))
return { entries.pt.first, entries.pt.second };
return {};
}
void mem_ctx::set_pte(void* addr, const ::pte& pte, bool use_hyperspace)
{
if (!dirbase || !addr)
return;
if (use_hyperspace)
v_ctx->wkm(v_ctx->get_virtual(reinterpret_cast<std::uintptr_t>(addr)), pte);
else
write_phys(addr, pte);
}
std::pair<ppde, pde> mem_ctx::get_pde(void* addr, bool use_hyperspace)
{
if (!dirbase || !addr)
return {};
pt_entries entries;
if ((use_hyperspace ? hyperspace_entries(entries, addr) : (bool)virt_to_phys(entries, addr)))
return { entries.pd.first, entries.pd.second };
return {};
}
void mem_ctx::set_pde(void* addr, const ::pde& pde, bool use_hyperspace)
{
if (!this->dirbase || !addr)
return;
if (use_hyperspace)
v_ctx->wkm(v_ctx->get_virtual(reinterpret_cast<std::uintptr_t>(addr)), pde);
else
write_phys(addr, pde);
}
std::pair<ppdpte, pdpte> mem_ctx::get_pdpte(void* addr, bool use_hyperspace)
{
if (!dirbase || !addr)
return {};
pt_entries entries;
if ((use_hyperspace ? hyperspace_entries(entries, addr) : (bool)virt_to_phys(entries, addr)))
return { entries.pdpt.first, entries.pdpt.second };
return {};
}
void mem_ctx::set_pdpte(void* addr, const ::pdpte& pdpte, bool use_hyperspace)
{
if (!this->dirbase || !addr)
return;
if (use_hyperspace)
v_ctx->wkm(v_ctx->get_virtual(reinterpret_cast<std::uintptr_t>(addr)), pdpte);
else
write_phys(addr, pdpte);
}
std::pair<ppml4e, pml4e> mem_ctx::get_pml4e(void* addr, bool use_hyperspace)
{
if (!this->dirbase || !addr)
return {};
pt_entries entries;
if ((use_hyperspace ? hyperspace_entries(entries, addr) : (bool)virt_to_phys(entries, addr)))
return { entries.pml4.first, entries.pml4.second };
return {};
}
void mem_ctx::set_pml4e(void* addr, const ::pml4e& pml4e, bool use_hyperspace)
{
if (!this->dirbase || !addr)
return;
if (use_hyperspace)
v_ctx->wkm(v_ctx->get_virtual(reinterpret_cast<std::uintptr_t>(addr)), pml4e);
else
write_phys(addr, pml4e);
}
std::pair<void*, void*> mem_ctx::read_virtual(void* buffer, void* addr, std::size_t size)
{
if (!buffer || !addr || !size || !dirbase)
return {};
virt_addr_t virt_addr{ addr };
if (size <= PAGE_4KB - virt_addr.offset)
{
pt_entries entries;
read_phys
(
buffer,
virt_to_phys(entries, addr),
size
);
return
{
reinterpret_cast<void*>(reinterpret_cast<std::uintptr_t>(buffer) + size),
reinterpret_cast<void*>(reinterpret_cast<std::uintptr_t>(addr) + size)
};
}
else
{
// cut remainder
const auto [new_buffer_addr, new_addr] = read_virtual
(
buffer,
addr,
PAGE_4KB - virt_addr.offset
);
// forward work load
return read_virtual
(
new_buffer_addr,
new_addr,
size - (PAGE_4KB - virt_addr.offset)
);
}
}
std::pair<void*, void*> mem_ctx::write_virtual(void* buffer, void* addr, std::size_t size)
{
if (!buffer || !addr || !size || !dirbase)
return {};
virt_addr_t virt_addr{ addr };
if (size <= PAGE_4KB - virt_addr.offset)
{
pt_entries entries;
write_phys
(
buffer,
virt_to_phys(entries, addr),
size
);
return
{
reinterpret_cast<void*>(reinterpret_cast<std::uintptr_t>(buffer) + size),
reinterpret_cast<void*>(reinterpret_cast<std::uintptr_t>(addr) + size)
};
}
else
{
// cut remainder
const auto [new_buffer_addr, new_addr] = write_virtual
(
buffer,
addr,
PAGE_4KB - virt_addr.offset
);
// forward work load
return write_virtual
(
new_buffer_addr,
new_addr,
size - (PAGE_4KB - virt_addr.offset)
);
}
}
bool mem_ctx::read_phys(void* buffer, void* addr, std::size_t size)
{
if (!buffer || !addr || !size)
return false;
const auto temp_page = set_page(addr);
__try
{
memcpy(buffer, temp_page, size);
}
__except (EXCEPTION_EXECUTE_HANDLER)
{
return false;
}
return true;
}
bool mem_ctx::write_phys(void* buffer, void* addr, std::size_t size)
{
if (!buffer || !addr || !size)
return false;
const auto temp_page = set_page(addr);
__try
{
memcpy(temp_page, buffer, size);
}
__except (EXCEPTION_EXECUTE_HANDLER)
{
return false;
}
return true;
}
void* mem_ctx::virt_to_phys(pt_entries& entries, void* addr)
{
if (!addr || !this->dirbase)
return {};
const virt_addr_t virt_addr{ addr };
// traverse paging tables
auto pml4e = read_phys<::pml4e>(
reinterpret_cast<ppml4e>(this->dirbase) + virt_addr.pml4_index);
entries.pml4.first = reinterpret_cast<ppml4e>(this->dirbase) + virt_addr.pml4_index;
entries.pml4.second = pml4e;
if (!pml4e.value)
return NULL;
auto pdpte = read_phys<::pdpte>(
reinterpret_cast<ppdpte>(pml4e.pfn << 12) + virt_addr.pdpt_index);
entries.pdpt.first = reinterpret_cast<ppdpte>(pml4e.pfn << 12) + virt_addr.pdpt_index;
entries.pdpt.second = pdpte;
if (!pdpte.value)
return NULL;
auto pde = read_phys<::pde>(
reinterpret_cast<ppde>(pdpte.pfn << 12) + virt_addr.pd_index);
entries.pd.first = reinterpret_cast<ppde>(pdpte.pfn << 12) + virt_addr.pd_index;
entries.pd.second = pde;
if (!pde.value)
return NULL;
auto pte = read_phys<::pte>(
reinterpret_cast<ppte>(pde.pfn << 12) + virt_addr.pt_index);
entries.pt.first = reinterpret_cast<ppte>(pde.pfn << 12) + virt_addr.pt_index;
entries.pt.second = pte;
if (!pte.value)
return NULL;
return reinterpret_cast<void*>((pte.pfn << 12) + virt_addr.offset);
}
unsigned mem_ctx::get_pid() const
{
return this->pid;
}
void* mem_ctx::get_dirbase() const
{
return this->dirbase;
}
pml4e mem_ctx::operator[](std::uint16_t pml4_idx)
{
return read_phys<::pml4e>(reinterpret_cast<ppml4e>(this->dirbase) + pml4_idx);
}
pdpte mem_ctx::operator[](const std::pair<std::uint16_t, std::uint16_t>& entry_idx)
{
const auto pml4_entry = this->operator[](entry_idx.first);
return read_phys<::pdpte>(reinterpret_cast<ppdpte>(pml4_entry.pfn << 12) + entry_idx.second);
}
pde mem_ctx::operator[](const std::tuple<std::uint16_t, std::uint16_t, std::uint16_t>& entry_idx)
{
const auto pdpt_entry = this->operator[]({ std::get<0>(entry_idx), std::get<1>(entry_idx) });
return read_phys<::pde>(reinterpret_cast<ppde>(pdpt_entry.pfn << 12) + std::get<2>(entry_idx));
}
pte mem_ctx::operator[](const std::tuple<std::uint16_t, std::uint16_t, std::uint16_t, std::uint16_t>& entry_idx)
{
const auto pd_entry = this->operator[]({ std::get<0>(entry_idx), std::get<1>(entry_idx), std::get<2>(entry_idx) });
return read_phys<::pte>(reinterpret_cast<ppte>(pd_entry.pfn << 12) + std::get<3>(entry_idx));
}
}