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-rw-r--r--drivers/firmware/efi/libstub/arm-stub.c22
1 files changed, 18 insertions, 4 deletions
diff --git a/drivers/firmware/efi/libstub/arm-stub.c b/drivers/firmware/efi/libstub/arm-stub.c
index 414deb85c2e5..07f967c4c567 100644
--- a/drivers/firmware/efi/libstub/arm-stub.c
+++ b/drivers/firmware/efi/libstub/arm-stub.c
@@ -20,7 +20,7 @@
bool __nokaslr;
-static int efi_secureboot_enabled(efi_system_table_t *sys_table_arg)
+static int efi_get_secureboot(efi_system_table_t *sys_table_arg)
{
static efi_guid_t const var_guid = EFI_GLOBAL_VARIABLE_GUID;
static efi_char16_t const var_name[] = {
@@ -39,8 +39,12 @@ static int efi_secureboot_enabled(efi_system_table_t *sys_table_arg)
return val;
case EFI_NOT_FOUND:
return 0;
+ case EFI_DEVICE_ERROR:
+ return -EIO;
+ case EFI_SECURITY_VIOLATION:
+ return -EACCES;
default:
- return 1;
+ return -EINVAL;
}
}
@@ -185,6 +189,7 @@ unsigned long efi_entry(void *handle, efi_system_table_t *sys_table,
efi_guid_t loaded_image_proto = LOADED_IMAGE_PROTOCOL_GUID;
unsigned long reserve_addr = 0;
unsigned long reserve_size = 0;
+ int secure_boot = 0;
/* Check if we were booted by the EFI firmware */
if (sys_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
@@ -250,12 +255,21 @@ unsigned long efi_entry(void *handle, efi_system_table_t *sys_table,
if (status != EFI_SUCCESS)
pr_efi_err(sys_table, "Failed to parse EFI cmdline options\n");
+ secure_boot = efi_get_secureboot(sys_table);
+ if (secure_boot > 0)
+ pr_efi(sys_table, "UEFI Secure Boot is enabled.\n");
+
+ if (secure_boot < 0) {
+ pr_efi_err(sys_table,
+ "could not determine UEFI Secure Boot status.\n");
+ }
+
/*
* Unauthenticated device tree data is a security hazard, so
* ignore 'dtb=' unless UEFI Secure Boot is disabled.
*/
- if (efi_secureboot_enabled(sys_table)) {
- pr_efi(sys_table, "UEFI Secure Boot is enabled.\n");
+ if (secure_boot != 0 && strstr(cmdline_ptr, "dtb=")) {
+ pr_efi(sys_table, "Ignoring DTB from command line.\n");
} else {
status = handle_cmdline_files(sys_table, image, cmdline_ptr,
"dtb=",