[PATCH] efi_loader: remove comparisons to string literals from runtime

[Ilias Apalodimas]

On EFI runtime services, we manage to preserve string literals
by placing the .efi_runtime section just before .data and preserving
it when fixing up the runtime memory by marking surrounding boottime
code as runtime. This is ok for now but will break if we update any
linker scripts and decouple .text and .runtime sections.

So let's define the strings we used to compare in the stack for
runtime services

Signed-off-by: Ilias Apalodimas <ilias.apalodimas at linaro.org>
---
 lib/efi_loader/efi_var_mem.c      | 3 ++-
 lib/efi_loader/efi_variable_tee.c | 3 ++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/lib/efi_loader/efi_var_mem.c b/lib/efi_loader/efi_var_mem.c
index b265d95dd6ba..985e0baa128d 100644
--- a/lib/efi_loader/efi_var_mem.c
+++ b/lib/efi_loader/efi_var_mem.c
@@ -310,6 +310,7 @@ efi_get_variable_mem(const u16 *variable_name, const efi_guid_t *vendor,
 {
 	efi_uintn_t old_size;
 	struct efi_var_entry *var;
+	u16 vtf[] = u"VarToFile";
 	u16 *pdata;
 
 	if (!variable_name || !vendor || !data_size)
@@ -331,7 +332,7 @@ efi_get_variable_mem(const u16 *variable_name, const efi_guid_t *vendor,
 	if (timep)
 		*timep = var->time;
 
-	if (!u16_strcmp(variable_name, u"VarToFile"))
+	if (!u16_strcmp(variable_name, vtf))
 		return efi_var_collect_mem(data, data_size, EFI_VARIABLE_NON_VOLATILE);
 
 	old_size = *data_size;
diff --git a/lib/efi_loader/efi_variable_tee.c b/lib/efi_loader/efi_variable_tee.c
index 0d090d051dd4..8d173e58d2f7 100644
--- a/lib/efi_loader/efi_variable_tee.c
+++ b/lib/efi_loader/efi_variable_tee.c
@@ -780,6 +780,7 @@ efi_status_t efi_set_variable_int(const u16 *variable_name,
 	efi_uintn_t payload_size;
 	efi_uintn_t name_size;
 	u8 *comm_buf = NULL;
+	u16 pk[] = u"PK";
 	bool ro;
 
 	if (!variable_name || variable_name[0] == 0 || !vendor) {
@@ -858,7 +859,7 @@ efi_status_t efi_set_variable_int(const u16 *variable_name,
 	if (alt_ret != EFI_SUCCESS)
 		goto out;
 
-	if (!u16_strcmp(variable_name, u"PK"))
+	if (!u16_strcmp(variable_name, pk))
 		alt_ret = efi_init_secure_state();
 out:
 	free(comm_buf);
-- 
2.43.0