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

[Ilias Apalodimas]

For EFI runtime services, we manage to preserve string literals
by placing the .efi_runtime section just before .data and preserving
it when marking 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 appropriate
section 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..31180df9e3a0 100644
--- a/lib/efi_loader/efi_var_mem.c
+++ b/lib/efi_loader/efi_var_mem.c
@@ -19,6 +19,7 @@
  */
 static struct efi_var_file __efi_runtime_data *efi_var_buf;
 static struct efi_var_entry __efi_runtime_data *efi_current_var;
+static const u16 __efi_runtime_rodata vtf[] = u"VarToFile";
 
 /**
  * efi_var_mem_compare() - compare GUID and name with a variable
@@ -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..6a1fa39bb6f3 100644
--- a/lib/efi_loader/efi_variable_tee.c
+++ b/lib/efi_loader/efi_variable_tee.c
@@ -41,6 +41,7 @@ static u16 mm_sp_id;
 extern struct efi_var_file __efi_runtime_data *efi_var_buf;
 static efi_uintn_t max_buffer_size;	/* comm + var + func + data */
 static efi_uintn_t max_payload_size;	/* func + data */
+static const u16 __efi_runtime_rodata pk[] = u"PK";
 
 struct mm_connection {
 	struct udevice *tee;
@@ -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);
-- 
2.47.2