[PATCH v4] efi_loader: update SetVariable attribute check

[Masahisa Kojima]

UEFI specification v2.10 says that
EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS is deprecated and
EFI_UNSUPPORTED should be returned in SetVariable variable service.
Current implementation returns EFI_INVALID_PARAMETER,
let's fix the return value.

Together with above change, this commit also updates the SetVariable
attribute check to be aligned with the EDK2 reference implementation.

UEFI specification says "HwErrRecSupport" variable supplies the level
of support for Hardware Error Record Persistence, add check of
this variable for EFI_VARIABLE_HARDWARE_ERROR_RECORD attribute.

Signed-off-by: Masahisa Kojima <masahisa.kojima at linaro.org>
---
Changes in v4:
- update HR attribute check(need NV,BS,RT)
- check HwErrRecSupport variable for HR variables

Changes in v3:
- accept no access attribute for deletion

Changes in v2:
- fix coding style
- HR must be set with NV

 lib/efi_loader/efi_variable.c | 43 +++++++++++++++++++++++++++++------
 1 file changed, 36 insertions(+), 7 deletions(-)

diff --git a/lib/efi_loader/efi_variable.c b/lib/efi_loader/efi_variable.c
index 5804f69954..f25006badf 100644
--- a/lib/efi_loader/efi_variable.c
+++ b/lib/efi_loader/efi_variable.c
@@ -230,11 +230,43 @@ efi_status_t efi_set_variable_int(const u16 *variable_name,
 	u64 time = 0;
 	enum efi_auth_var_type var_type;
 
-	if (!variable_name || !*variable_name || !vendor ||
-	    ((attributes & EFI_VARIABLE_RUNTIME_ACCESS) &&
-	     !(attributes & EFI_VARIABLE_BOOTSERVICE_ACCESS)))
+	if (!variable_name || !*variable_name || !vendor)
 		return EFI_INVALID_PARAMETER;
 
+	if (data_size && !data)
+		return EFI_INVALID_PARAMETER;
+
+	/* EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS is deprecated */
+	if (attributes & EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS)
+		return EFI_UNSUPPORTED;
+
+	/* Make sure if runtime bit is set, boot service bit is set also */
+	if ((attributes &
+	     (EFI_VARIABLE_RUNTIME_ACCESS | EFI_VARIABLE_BOOTSERVICE_ACCESS)) ==
+	    EFI_VARIABLE_RUNTIME_ACCESS)
+		return EFI_INVALID_PARAMETER;
+
+	/* only EFI_VARIABLE_NON_VOLATILE attribute is invalid */
+	if ((attributes & EFI_VARIABLE_MASK) == EFI_VARIABLE_NON_VOLATILE)
+		return EFI_INVALID_PARAMETER;
+
+	if (attributes & EFI_VARIABLE_HARDWARE_ERROR_RECORD) {
+		efi_uintn_t size;
+		u16 hw_err_rec_support = 0;
+
+		/* Make sure HR is set with NV, BS and RT */
+		if (!(attributes & EFI_VARIABLE_NON_VOLATILE) ||
+		    !(attributes & EFI_VARIABLE_RUNTIME_ACCESS) ||
+		    !(attributes & EFI_VARIABLE_BOOTSERVICE_ACCESS))
+			return EFI_INVALID_PARAMETER;
+
+		size = sizeof(hw_err_rec_support);
+		ret = efi_get_variable_mem(L"HwErrRecSupport", &efi_global_variable_guid,
+					   NULL, &size, &hw_err_rec_support, NULL);
+		if (ret == EFI_NOT_FOUND || !hw_err_rec_support)
+			return EFI_UNSUPPORTED;
+	}
+
 	/* check if a variable exists */
 	var = efi_var_mem_find(vendor, variable_name, NULL);
 	append = !!(attributes & EFI_VARIABLE_APPEND_WRITE);
@@ -281,8 +313,6 @@ efi_status_t efi_set_variable_int(const u16 *variable_name,
 
 	/* authenticate a variable */
 	if (IS_ENABLED(CONFIG_EFI_SECURE_BOOT)) {
-		if (attributes & EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS)
-			return EFI_INVALID_PARAMETER;
 		if (attributes &
 		    EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS) {
 			u32 env_attr;
@@ -300,8 +330,7 @@ efi_status_t efi_set_variable_int(const u16 *variable_name,
 		}
 	} else {
 		if (attributes &
-		    (EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS |
-		     EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS)) {
+		    EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS) {
 			EFI_PRINT("Secure boot is not configured\n");
 			return EFI_INVALID_PARAMETER;
 		}
-- 
2.17.1