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PSKDM/nasa-mapper/mem_ctx/mem_ctx.cpp

424 lines
9.6 KiB

4 years ago
#include "mem_ctx.hpp"
#include <cassert>
namespace physmeme
{
mem_ctx::mem_ctx(kernel_ctx& krnl_ctx, DWORD pid)
:
k_ctx(&krnl_ctx),
dirbase(get_dirbase(krnl_ctx, pid)),
pid(pid)
{
genesis_page.first = VirtualAlloc(
NULL,
PAGE_SIZE,
MEM_COMMIT | MEM_RESERVE,
PAGE_READWRITE
);
//
// page in the page, do not remove this makes the entries.
//
*(std::uintptr_t*)genesis_page.first = 0xC0FFEE;
//
// get the ppte and pte of the page we allocated
//
auto [page_ppte, page_pte] = get_pte(genesis_page.first, true);
genesis_page.second = page_pte;
//
// allocate a page that will get the mapping of the first pages PT
//
genesis_cursor.first = reinterpret_cast<::ppte>(
VirtualAlloc(
NULL,
0x1000,
MEM_COMMIT | MEM_RESERVE,
PAGE_READWRITE
));
//
// page it in
//
*(std::uintptr_t*)genesis_cursor.first = 0xC0FFEE;
//
// get ppte and pte of the cursor page.
//
auto [cursor_ppte, cursor_pte] = get_pte(genesis_cursor.first, true);
genesis_cursor.second = cursor_pte;
//
// change the page to the PT of the first page we allocated.
//
cursor_pte.pfn = reinterpret_cast<std::uint64_t>(page_ppte) >> 12;
set_pte(genesis_cursor.first, cursor_pte, true);
//
// change the offset of genesis cursor page to genesis pages pt_index since the page is now a PT
// WARNING: pointer arithmetic, do not add pt_index * 8
//
genesis_cursor.first += +virt_addr_t{ genesis_page.first }.pt_index;
FLUSH_TLB;
}
mem_ctx::~mem_ctx()
{
set_pte(genesis_page.first, genesis_page.second, true);
set_pte(genesis_cursor.first, genesis_cursor.second, true);
}
void* mem_ctx::set_page(void* addr)
{
this->page_offset = virt_addr_t{ addr }.offset;
this->genesis_cursor.first->pfn = reinterpret_cast<uint64_t>(addr) >> 12;
FLUSH_TLB;
return get_page();
}
void* mem_ctx::get_page() const
{
return reinterpret_cast<void*>(
reinterpret_cast<std::uint64_t>(
this->genesis_page.first) + this->page_offset);
}
void* mem_ctx::get_dirbase(kernel_ctx& k_ctx, DWORD pid)
{
const auto peproc =
reinterpret_cast<std::uint64_t>(
k_ctx.get_peprocess(pid));
if (!peproc) return NULL;
pte dirbase = k_ctx.rkm<pte>(
reinterpret_cast<void*>(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 = k_ctx->rkm<pml4e>(
k_ctx->get_virtual(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 = k_ctx->rkm<pdpte>(
k_ctx->get_virtual(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 = k_ctx->rkm<pde>(
k_ctx->get_virtual(entries.pd.first));
// if its a 2mb page
if (entries.pd.second.page_size)
{
memcpy(
&entries.pt.second,
&entries.pd.second,
sizeof(pte)
);
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 = k_ctx->rkm<pte>(
k_ctx->get_virtual(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) : virt_to_phys(entries, addr))
{
::pte pte;
memcpy(&pte, &entries.pt.second, sizeof(pte));
return { entries.pt.first, pte };
}
return {};
}
void mem_ctx::set_pte(void* addr, const ::pte& pte, bool use_hyperspace)
{
if (!dirbase || !addr)
return;
pt_entries entries;
if (use_hyperspace)
if (hyperspace_entries(entries, addr))
k_ctx->wkm(
k_ctx->get_virtual(entries.pt.first),
pte
);
else
if (virt_to_phys(entries, addr))
write_phys(entries.pt.first, 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) : virt_to_phys(entries, addr))
{
::pde pde;
memcpy(
&pde,
&entries.pd.second,
sizeof(pde)
);
return { entries.pd.first, pde };
}
return {};
}
void mem_ctx::set_pde(void* addr, const ::pde& pde, bool use_hyperspace)
{
if (!dirbase || !addr)
return;
pt_entries entries;
if (use_hyperspace)
if (hyperspace_entries(entries, addr))
k_ctx->wkm(
k_ctx->get_virtual(entries.pd.first),
pde
);
else
if (virt_to_phys(entries, addr))
write_phys(entries.pd.first, 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) : 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 (!dirbase || !addr)
return;
pt_entries entries;
if (use_hyperspace)
if (hyperspace_entries(entries, addr))
k_ctx->wkm(
k_ctx->get_virtual(entries.pdpt.first),
pdpte
);
else
if (virt_to_phys(entries, addr))
write_phys(entries.pdpt.first, pdpte);
}
std::pair<ppml4e, pml4e> mem_ctx::get_pml4e(void* addr, bool use_hyperspace)
{
if (!dirbase || !addr)
return { {}, {} };
pt_entries entries;
if (use_hyperspace ? hyperspace_entries(entries, addr) : 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 (!dirbase || !addr)
return;
pt_entries entries;
if (use_hyperspace)
if (hyperspace_entries(entries, addr))
k_ctx->wkm(
k_ctx->get_virtual(entries.pml4.first),
pml4e
);
else
if (virt_to_phys(entries, addr))
write_phys(entries.pml4.first, 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_SIZE - 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_SIZE - virt_addr.offset
);
// forward work load
return read_virtual(
new_buffer_addr,
new_addr,
size - (PAGE_SIZE - 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_SIZE - 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_SIZE - virt_addr.offset
);
// forward work load
return write_virtual(
new_buffer_addr,
new_addr,
size - (PAGE_SIZE - virt_addr.offset)
);
}
}
void mem_ctx::read_phys(void* buffer, void* addr, std::size_t size)
{
if (!buffer || !addr || !size)
return;
auto temp_page = set_page(addr);
if (temp_page)
memcpy(buffer, temp_page, size);
}
void mem_ctx::write_phys(void* buffer, void* addr, std::size_t size)
{
if (!buffer || !addr || !size)
return;
auto temp_page = set_page(addr);
if (temp_page)
memcpy(temp_page, buffer, size);
}
void* mem_ctx::virt_to_phys(pt_entries& entries, void* addr)
{
if (!addr || !dirbase)
return {};
virt_addr_t virt_addr{ addr };
//
// traverse paging tables
//
auto pml4e = read_phys<::pml4e>(
reinterpret_cast<ppml4e>(dirbase) + virt_addr.pml4_index);
entries.pml4.first = reinterpret_cast<ppml4e>(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 pid;
}
void* mem_ctx::get_dirbase() const
{
return dirbase;
}
}