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-rw-r--r--arch/x86/mm/pgprot.c63
1 files changed, 63 insertions, 0 deletions
diff --git a/arch/x86/mm/pgprot.c b/arch/x86/mm/pgprot.c
new file mode 100644
index 0000000000..c84bd9540b
--- /dev/null
+++ b/arch/x86/mm/pgprot.c
@@ -0,0 +1,63 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/export.h>
+#include <linux/mm.h>
+#include <asm/pgtable.h>
+#include <asm/mem_encrypt.h>
+
+static pgprot_t protection_map[16] __ro_after_init = {
+ [VM_NONE] = PAGE_NONE,
+ [VM_READ] = PAGE_READONLY,
+ [VM_WRITE] = PAGE_COPY,
+ [VM_WRITE | VM_READ] = PAGE_COPY,
+ [VM_EXEC] = PAGE_READONLY_EXEC,
+ [VM_EXEC | VM_READ] = PAGE_READONLY_EXEC,
+ [VM_EXEC | VM_WRITE] = PAGE_COPY_EXEC,
+ [VM_EXEC | VM_WRITE | VM_READ] = PAGE_COPY_EXEC,
+ [VM_SHARED] = PAGE_NONE,
+ [VM_SHARED | VM_READ] = PAGE_READONLY,
+ [VM_SHARED | VM_WRITE] = PAGE_SHARED,
+ [VM_SHARED | VM_WRITE | VM_READ] = PAGE_SHARED,
+ [VM_SHARED | VM_EXEC] = PAGE_READONLY_EXEC,
+ [VM_SHARED | VM_EXEC | VM_READ] = PAGE_READONLY_EXEC,
+ [VM_SHARED | VM_EXEC | VM_WRITE] = PAGE_SHARED_EXEC,
+ [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ] = PAGE_SHARED_EXEC
+};
+
+void add_encrypt_protection_map(void)
+{
+ unsigned int i;
+
+ for (i = 0; i < ARRAY_SIZE(protection_map); i++)
+ protection_map[i] = pgprot_encrypted(protection_map[i]);
+}
+
+pgprot_t vm_get_page_prot(unsigned long vm_flags)
+{
+ unsigned long val = pgprot_val(protection_map[vm_flags &
+ (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]);
+
+#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
+ /*
+ * Take the 4 protection key bits out of the vma->vm_flags value and
+ * turn them in to the bits that we can put in to a pte.
+ *
+ * Only override these if Protection Keys are available (which is only
+ * on 64-bit).
+ */
+ if (vm_flags & VM_PKEY_BIT0)
+ val |= _PAGE_PKEY_BIT0;
+ if (vm_flags & VM_PKEY_BIT1)
+ val |= _PAGE_PKEY_BIT1;
+ if (vm_flags & VM_PKEY_BIT2)
+ val |= _PAGE_PKEY_BIT2;
+ if (vm_flags & VM_PKEY_BIT3)
+ val |= _PAGE_PKEY_BIT3;
+#endif
+
+ val = __sme_set(val);
+ if (val & _PAGE_PRESENT)
+ val &= __supported_pte_mask;
+ return __pgprot(val);
+}
+EXPORT_SYMBOL(vm_get_page_prot);