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nx: Add memory attribute get/set API

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For NX we need to set the page access permission attributes for write
and execute permissions. This patch adds two new primitives, grub_set_mem_attrs()
and grub_clear_mem_attrs(), and associated constants definitions used
for that purpose. For most platforms it adds a dummy implementation.
On EFI platforms it implements the primitives using the EFI Memory
Attribute Protocol, defined in UEFI 2.10 specification.

Signed-off-by: Peter Jones <pjones@redhat.com>
Signed-off-by: Jan Setje-Eilers <jan.setjeeilers@oracle.com>
Signed-off-by: Mate Kukri <mate.kukri@canonical.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
This commit is contained in:
Mate Kukri authored and Daniel Kiper committed 2024-10-11 14:35:54 +02:00
1 parent 9fb80dd57e
commit 09ca66673a
3 files changed
+169
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grub-core/kern/efi/mm.c
+109
View File
@@ -689,3 +689,112 @@ grub_efi_get_ram_base(grub_addr_t *base_addr)
return GRUB_ERR_NONE;
}
#endif
static grub_uint64_t
grub_mem_attrs_to_uefi_mem_attrs (grub_mem_attr_t attrs)
{
grub_efi_uint64_t ret = GRUB_EFI_MEMORY_RP | GRUB_EFI_MEMORY_RO | GRUB_EFI_MEMORY_XP;
if (attrs & GRUB_MEM_ATTR_R)
ret &= ~GRUB_EFI_MEMORY_RP;
if (attrs & GRUB_MEM_ATTR_W)
ret &= ~GRUB_EFI_MEMORY_RO;
if (attrs & GRUB_MEM_ATTR_X)
ret &= ~GRUB_EFI_MEMORY_XP;
return ret;
}
static grub_mem_attr_t
uefi_mem_attrs_to_grub_mem_attrs (grub_efi_uint64_t attrs)
{
grub_mem_attr_t ret = GRUB_MEM_ATTR_R | GRUB_MEM_ATTR_W | GRUB_MEM_ATTR_X;
if (attrs & GRUB_EFI_MEMORY_RP)
ret &= ~GRUB_MEM_ATTR_R;
if (attrs & GRUB_EFI_MEMORY_RO)
ret &= ~GRUB_MEM_ATTR_W;
if (attrs & GRUB_EFI_MEMORY_XP)
ret &= ~GRUB_MEM_ATTR_X;
return ret;
}
grub_err_t
grub_get_mem_attrs (grub_addr_t addr, grub_size_t size, grub_mem_attr_t *attrs)
{
grub_efi_memory_attribute_protocol_t *proto;
grub_efi_physical_address_t physaddr = addr;
static grub_guid_t protocol_guid = GRUB_EFI_MEMORY_ATTRIBUTE_PROTOCOL_GUID;
grub_efi_status_t efi_status;
grub_efi_uint64_t efi_attrs;
if (physaddr & (GRUB_EFI_PAGE_SIZE - 1) || size & (GRUB_EFI_PAGE_SIZE - 1) || size == 0 || attrs == NULL)
return grub_error (GRUB_ERR_BAD_ARGUMENT, "%s() called with invalid arguments", __FUNCTION__);
proto = grub_efi_locate_protocol (&protocol_guid, 0);
if (proto == NULL)
{
/* No protocol -> do nothing, all memory is RWX in boot services */
*attrs = GRUB_MEM_ATTR_R | GRUB_MEM_ATTR_W | GRUB_MEM_ATTR_X;
return GRUB_ERR_NONE;
}
efi_status = proto->get_memory_attributes (proto, physaddr, size, &efi_attrs);
if (efi_status != GRUB_EFI_SUCCESS)
return grub_error (GRUB_ERR_BAD_ARGUMENT, "%s() called with invalid arguments", __FUNCTION__);
*attrs = uefi_mem_attrs_to_grub_mem_attrs (efi_attrs);
grub_dprintf ("nx", "get 0x%" PRIxGRUB_ADDR "-0x%" PRIxGRUB_ADDR ":%c%c%c\n",
addr, addr + size - 1,
(*attrs & GRUB_MEM_ATTR_R) ? 'r' : '-',
(*attrs & GRUB_MEM_ATTR_W) ? 'w' : '-',
(*attrs & GRUB_MEM_ATTR_X) ? 'x' : '-');
return GRUB_ERR_NONE;
}
grub_err_t
grub_update_mem_attrs (grub_addr_t addr, grub_size_t size,
grub_mem_attr_t set_attrs, grub_mem_attr_t clear_attrs)
{
grub_efi_memory_attribute_protocol_t *proto;
grub_efi_physical_address_t physaddr = addr;
static grub_guid_t protocol_guid = GRUB_EFI_MEMORY_ATTRIBUTE_PROTOCOL_GUID;
grub_efi_status_t efi_status = GRUB_EFI_SUCCESS;
grub_efi_uint64_t uefi_set_attrs, uefi_clear_attrs;
if (physaddr & (GRUB_EFI_PAGE_SIZE - 1) || size & (GRUB_EFI_PAGE_SIZE - 1) || size == 0)
return grub_error (GRUB_ERR_BAD_ARGUMENT, "%s() called with invalid arguments", __FUNCTION__);
proto = grub_efi_locate_protocol (&protocol_guid, 0);
if (proto == NULL)
/* No protocol -> do nothing, all memory is RWX in boot services */
return GRUB_ERR_NONE;
uefi_set_attrs = grub_mem_attrs_to_uefi_mem_attrs (set_attrs);
uefi_clear_attrs = grub_mem_attrs_to_uefi_mem_attrs (clear_attrs);
if (uefi_set_attrs)
efi_status = proto->set_memory_attributes (proto, physaddr, size, uefi_set_attrs);
if (efi_status == GRUB_EFI_SUCCESS && uefi_clear_attrs)
efi_status = proto->clear_memory_attributes (proto, physaddr, size, uefi_clear_attrs);
if (efi_status != GRUB_EFI_SUCCESS)
return grub_error (GRUB_ERR_BAD_ARGUMENT, "%s() called with invalid arguments", __FUNCTION__);
grub_dprintf ("nx", "set +%s%s%s -%s%s%s on 0x%" PRIxGRUB_ADDR "-0x%" PRIxGRUB_ADDR "\n",
(set_attrs & GRUB_MEM_ATTR_R) ? "r" : "",
(set_attrs & GRUB_MEM_ATTR_W) ? "w" : "",
(set_attrs & GRUB_MEM_ATTR_X) ? "x" : "",
(clear_attrs & GRUB_MEM_ATTR_R) ? "r" : "",
(clear_attrs & GRUB_MEM_ATTR_W) ? "w" : "",
(clear_attrs & GRUB_MEM_ATTR_X) ? "x" : "",
addr, addr + size - 1);
return GRUB_ERR_NONE;
}