void __init efi_runtime_update_mappings(void)
{
efi_memory_desc_t *md;
if (efi_enabled(EFI_OLD_MEMMAP)) {
if (__supported_pte_mask & _PAGE_NX)
runtime_code_page_mkexec();
return;
}
/*
* Use the EFI Memory Attribute Table for mapping permissions if it
* exists, since it is intended to supersede EFI_PROPERTIES_TABLE.
*/
if (efi_enabled(EFI_MEM_ATTR)) {
efi_memattr_apply_permissions(NULL, efi_update_mem_attr);
return;
}
/*
* EFI_MEMORY_ATTRIBUTES_TABLE is intended to replace
* EFI_PROPERTIES_TABLE. So, use EFI_PROPERTIES_TABLE to update
* permissions only if EFI_MEMORY_ATTRIBUTES_TABLE is not
* published by the firmware. Even if we find a buggy implementation of
* EFI_MEMORY_ATTRIBUTES_TABLE, don't fall back to
* EFI_PROPERTIES_TABLE, because of the same reason.
*/
if (!efi_enabled(EFI_NX_PE_DATA))
return;
for_each_efi_memory_desc(md) {
unsigned long pf = 0;
if (!(md->attribute & EFI_MEMORY_RUNTIME))
continue;
if (!(md->attribute & EFI_MEMORY_WB))
pf |= _PAGE_PCD;
if ((md->attribute & EFI_MEMORY_XP) ||
(md->type == EFI_RUNTIME_SERVICES_DATA))
pf |= _PAGE_NX;
if (!(md->attribute & EFI_MEMORY_RO) &&
(md->type != EFI_RUNTIME_SERVICES_CODE))
pf |= _PAGE_RW;
if (sev_active())
pf |= _PAGE_ENC;
efi_update_mappings(md, pf);
}
}
static int __init efi_update_mem_attr(struct mm_struct *mm, efi_memory_desc_t *md)
{
unsigned long pf = 0;
if (md->attribute & EFI_MEMORY_XP)
pf |= _PAGE_NX;
if (!(md->attribute & EFI_MEMORY_RO))
pf |= _PAGE_RW;
return efi_update_mappings(md, pf);
}
