efi: Discover BTI support in runtime services regions

[platform/kernel/linux-starfive.git] / drivers / firmware / efi / memattr.c

diff --git a/drivers/firmware/efi/memattr.c b/drivers/firmware/efi/memattr.c
index 0a9aba5..3cbf00f 100644 (file)
--- a/drivers/firmware/efi/memattr.c
+++ b/drivers/firmware/efi/memattr.c
@@ -129,6 +129,7 @@ int __init efi_memattr_apply_permissions(struct mm_struct *mm,
                                         efi_memattr_perm_setter fn)
 {
        efi_memory_attributes_table_t *tbl;
+       bool has_bti = false;
        int i, ret;
 
        if (tbl_size <= sizeof(*tbl))
@@ -150,6 +151,10 @@ int __init efi_memattr_apply_permissions(struct mm_struct *mm,
                return -ENOMEM;
        }
 
+       if (tbl->version > 1 &&
+           (tbl->flags & EFI_MEMORY_ATTRIBUTES_FLAGS_RT_FORWARD_CONTROL_FLOW_GUARD))
+               has_bti = true;
+
        if (efi_enabled(EFI_DBG))
                pr_info("Processing EFI Memory Attributes table:\n");
 
@@ -169,7 +174,7 @@ int __init efi_memattr_apply_permissions(struct mm_struct *mm,
                                efi_md_typeattr_format(buf, sizeof(buf), &md));
 
                if (valid) {
-                       ret = fn(mm, &md);
+                       ret = fn(mm, &md, has_bti);
                        if (ret)
                                pr_err("Error updating mappings, skipping subsequent md's\n");
                }