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// SPDX-License-Identifier: BSD-2-Clause-Patent
/*
* memattrs.c - EFI and DXE memory attribute helpers
* Copyright Peter Jones <pjones@redhat.com>
*/
#include "shim.h"
static inline uint64_t
shim_mem_attrs_to_uefi_mem_attrs (uint64_t attrs)
{
uint64_t ret = EFI_MEMORY_RP |
EFI_MEMORY_RO |
EFI_MEMORY_XP;
if (attrs & MEM_ATTR_R)
ret &= ~EFI_MEMORY_RP;
if (attrs & MEM_ATTR_W)
ret &= ~EFI_MEMORY_RO;
if (attrs & MEM_ATTR_X)
ret &= ~EFI_MEMORY_XP;
return ret;
}
static inline uint64_t
uefi_mem_attrs_to_shim_mem_attrs (uint64_t attrs)
{
uint64_t ret = MEM_ATTR_R |
MEM_ATTR_W |
MEM_ATTR_X;
if (attrs & EFI_MEMORY_RP)
ret &= ~MEM_ATTR_R;
if (attrs & EFI_MEMORY_RO)
ret &= ~MEM_ATTR_W;
if (attrs & EFI_MEMORY_XP)
ret &= ~MEM_ATTR_X;
return ret;
}
EFI_STATUS
get_mem_attrs (uintptr_t addr, size_t size, uint64_t *attrs)
{
EFI_MEMORY_ATTRIBUTE_PROTOCOL *proto = NULL;
EFI_PHYSICAL_ADDRESS physaddr = addr;
EFI_STATUS efi_status;
efi_status = LibLocateProtocol(&EFI_MEMORY_ATTRIBUTE_PROTOCOL_GUID,
(VOID **)&proto);
if (EFI_ERROR(efi_status) || !proto) {
dprint(L"No memory attribute protocol found: %r\n", efi_status);
if (!EFI_ERROR(efi_status))
efi_status = EFI_UNSUPPORTED;
return efi_status;
}
if (!IS_PAGE_ALIGNED(physaddr) || !IS_PAGE_ALIGNED(size) || size == 0 || attrs == NULL) {
dprint(L"%a called on 0x%llx-0x%llx and attrs 0x%llx\n",
__func__, (unsigned long long)physaddr,
(unsigned long long)(physaddr+size-1),
attrs);
return EFI_SUCCESS;
}
efi_status = proto->GetMemoryAttributes(proto, physaddr, size, attrs);
if (EFI_ERROR(efi_status)) {
dprint(L"GetMemoryAttributes(..., 0x%llx, 0x%x, 0x%x): %r\n",
physaddr, size, attrs, efi_status);
} else {
*attrs = uefi_mem_attrs_to_shim_mem_attrs (*attrs);
}
return efi_status;
}
EFI_STATUS
update_mem_attrs(uintptr_t addr, uint64_t size,
uint64_t set_attrs, uint64_t clear_attrs)
{
EFI_MEMORY_ATTRIBUTE_PROTOCOL *proto = NULL;
EFI_PHYSICAL_ADDRESS physaddr = addr;
EFI_STATUS efi_status, ret;
uint64_t before = 0, after = 0, uefi_set_attrs, uefi_clear_attrs;
efi_status = LibLocateProtocol(&EFI_MEMORY_ATTRIBUTE_PROTOCOL_GUID,
(VOID **)&proto);
if (EFI_ERROR(efi_status) || !proto)
return efi_status;
efi_status = get_mem_attrs (addr, size, &before);
if (EFI_ERROR(efi_status))
dprint(L"get_mem_attrs(0x%llx, 0x%llx, 0x%llx) -> 0x%lx\n",
(unsigned long long)addr, (unsigned long long)size,
&before, efi_status);
if (!IS_PAGE_ALIGNED(physaddr) || !IS_PAGE_ALIGNED(size) || size == 0) {
perror(L"Invalid call %a(addr:0x%llx-0x%llx, size:0x%llx, +%a%a%a, -%a%a%a)\n",
__func__, (unsigned long long)physaddr,
(unsigned long long)(physaddr + size - 1),
(unsigned long long)size,
(set_attrs & MEM_ATTR_R) ? "r" : "",
(set_attrs & MEM_ATTR_W) ? "w" : "",
(set_attrs & MEM_ATTR_X) ? "x" : "",
(clear_attrs & MEM_ATTR_R) ? "r" : "",
(clear_attrs & MEM_ATTR_W) ? "w" : "",
(clear_attrs & MEM_ATTR_X) ? "x" : "");
if (!IS_PAGE_ALIGNED(physaddr))
perror(L" addr is not page aligned\n");
if (!IS_PAGE_ALIGNED(size))
perror(L" size is not page aligned\n");
if (size == 0)
perror(L" size is 0\n");
return 0;
}
uefi_set_attrs = shim_mem_attrs_to_uefi_mem_attrs (set_attrs);
dprint("translating set_attrs from 0x%lx to 0x%lx\n", set_attrs, uefi_set_attrs);
uefi_clear_attrs = shim_mem_attrs_to_uefi_mem_attrs (clear_attrs);
dprint("translating clear_attrs from 0x%lx to 0x%lx\n", clear_attrs, uefi_clear_attrs);
efi_status = EFI_SUCCESS;
if (uefi_set_attrs) {
efi_status = proto->SetMemoryAttributes(proto, physaddr, size, uefi_set_attrs);
if (EFI_ERROR(efi_status)) {
dprint(L"Failed to set memory attrs:0x%0x physaddr:0x%llx size:0x%0lx status:%r\n",
uefi_set_attrs, physaddr, size, efi_status);
}
}
if (!EFI_ERROR(efi_status) && uefi_clear_attrs) {
efi_status = proto->ClearMemoryAttributes(proto, physaddr, size, uefi_clear_attrs);
if (EFI_ERROR(efi_status)) {
dprint(L"Failed to clear memory attrs:0x%0x physaddr:0x%llx size:0x%0lx status:%r\n",
uefi_clear_attrs, physaddr, size, efi_status);
}
}
ret = efi_status;
efi_status = get_mem_attrs (addr, size, &after);
if (EFI_ERROR(efi_status))
dprint(L"get_mem_attrs(0x%llx, %llu, 0x%llx) -> 0x%lx\n",
(unsigned long long)addr, (unsigned long long)size,
&after, efi_status);
dprint(L"set +%a%a%a -%a%a%a on 0x%llx-0x%llx before:%c%c%c after:%c%c%c\n",
(set_attrs & MEM_ATTR_R) ? "r" : "",
(set_attrs & MEM_ATTR_W) ? "w" : "",
(set_attrs & MEM_ATTR_X) ? "x" : "",
(clear_attrs & MEM_ATTR_R) ? "r" : "",
(clear_attrs & MEM_ATTR_W) ? "w" : "",
(clear_attrs & MEM_ATTR_X) ? "x" : "",
(unsigned long long)addr, (unsigned long long)(addr + size - 1),
(before & MEM_ATTR_R) ? 'r' : '-',
(before & MEM_ATTR_W) ? 'w' : '-',
(before & MEM_ATTR_X) ? 'x' : '-',
(after & MEM_ATTR_R) ? 'r' : '-',
(after & MEM_ATTR_W) ? 'w' : '-',
(after & MEM_ATTR_X) ? 'x' : '-');
return ret;
}
void
get_hsi_mem_info(void)
{
EFI_STATUS efi_status;
uintptr_t addr;
uint64_t attrs = 0;
uint32_t *tmp_alloc;
addr = ((uintptr_t)&get_hsi_mem_info) & ~EFI_PAGE_MASK;
efi_status = get_mem_attrs(addr, EFI_PAGE_SIZE, &attrs);
if (EFI_ERROR(efi_status)) {
error:
/*
* In this case we can't actually tell anything, so assume
* and report the worst case scenario.
*/
hsi_status = SHIM_HSI_STATUS_HEAPX |
SHIM_HSI_STATUS_STACKX |
SHIM_HSI_STATUS_ROW;
dprint(L"Setting HSI to 0x%lx due to error: %r\n", hsi_status, efi_status);
return;
} else {
hsi_status = SHIM_HSI_STATUS_HASMAP;
dprint(L"Setting HSI to 0x%lx\n", hsi_status);
}
if (!(hsi_status & SHIM_HSI_STATUS_HASMAP)) {
dprint(L"No memory protocol, not testing further\n");
return;
}
hsi_status = SHIM_HSI_STATUS_HASMAP;
if (attrs & MEM_ATTR_W) {
dprint(L"get_hsi_mem_info() is on a writable page: 0x%x->0x%x\n",
hsi_status, hsi_status | SHIM_HSI_STATUS_ROW);
hsi_status |= SHIM_HSI_STATUS_ROW;
}
addr = ((uintptr_t)&addr) & ~EFI_PAGE_MASK;
efi_status = get_mem_attrs(addr, EFI_PAGE_SIZE, &attrs);
if (EFI_ERROR(efi_status)) {
dprint(L"get_mem_attrs(0x%016llx, 0x%x, &attrs) failed.\n", addr, EFI_PAGE_SIZE);
goto error;
}
if (attrs & MEM_ATTR_X) {
dprint(L"Stack variable is on an executable page: 0x%x->0x%x\n",
hsi_status, hsi_status | SHIM_HSI_STATUS_STACKX);
hsi_status |= SHIM_HSI_STATUS_STACKX;
}
tmp_alloc = AllocatePool(EFI_PAGE_SIZE);
if (!tmp_alloc) {
dprint(L"Failed to allocate heap variable.\n");
goto error;
}
addr = ((uintptr_t)tmp_alloc) & ~EFI_PAGE_MASK;
efi_status = get_mem_attrs(addr, EFI_PAGE_SIZE, &attrs);
FreePool(tmp_alloc);
if (EFI_ERROR(efi_status)) {
dprint(L"get_mem_attrs(0x%016llx, 0x%x, &attrs) failed.\n", addr, EFI_PAGE_SIZE);
goto error;
}
if (attrs & MEM_ATTR_X) {
dprint(L"Heap variable is on an executable page: 0x%x->0x%x\n",
hsi_status, hsi_status | SHIM_HSI_STATUS_HEAPX);
hsi_status |= SHIM_HSI_STATUS_HEAPX;
}
}
// vim:fenc=utf-8:tw=75:noet
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