[GRUB PATCH RFC 10/18] efi: Return grub_efi_status_t from grub_efi_get_variable()

[Daniel Kiper <daniel.kiper@oracle.com>]

This is needed to properly detect and report UEFI Secure Boot status
to the x86 Linux kernel. The functionality will be added by subsequent
patches.

Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
---
 grub-core/commands/efi/efifwsetup.c |  8 ++++----
 grub-core/kern/efi/efi.c            | 16 +++++++++-------
 grub-core/video/efi_gop.c           |  2 +-
 include/grub/efi/efi.h              |  7 ++++---
 4 files changed, 18 insertions(+), 15 deletions(-)

diff --git a/grub-core/commands/efi/efifwsetup.c b/grub-core/commands/efi/efifwsetup.c
index 7a137a72a..eaca03283 100644
--- a/grub-core/commands/efi/efifwsetup.c
+++ b/grub-core/commands/efi/efifwsetup.c
@@ -38,8 +38,8 @@ grub_cmd_fwsetup (grub_command_t cmd __attribute__ ((unused)),
   grub_size_t oi_size;
   grub_efi_guid_t global = GRUB_EFI_GLOBAL_VARIABLE_GUID;
 
-  old_os_indications = grub_efi_get_variable ("OsIndications", &global,
-					      &oi_size);
+  grub_efi_get_variable ("OsIndications", &global, &oi_size,
+			 (void **) &old_os_indications);
 
   if (old_os_indications != NULL && oi_size == sizeof (os_indications))
     os_indications |= *old_os_indications;
@@ -63,8 +63,8 @@ efifwsetup_is_supported (void)
   grub_size_t oi_size = 0;
   grub_efi_guid_t global = GRUB_EFI_GLOBAL_VARIABLE_GUID;
 
-  os_indications_supported = grub_efi_get_variable ("OsIndicationsSupported",
-						    &global, &oi_size);
+  grub_efi_get_variable ("OsIndicationsSupported", &global, &oi_size,
+			 (void **) &os_indications_supported);
 
   if (!os_indications_supported)
     return 0;
diff --git a/grub-core/kern/efi/efi.c b/grub-core/kern/efi/efi.c
index 3a708ed72..81bc49f84 100644
--- a/grub-core/kern/efi/efi.c
+++ b/grub-core/kern/efi/efi.c
@@ -222,9 +222,9 @@ grub_efi_set_variable(const char *var, const grub_efi_guid_t *guid,
   return grub_error (GRUB_ERR_IO, "could not set EFI variable `%s'", var);
 }
 
-void *
+grub_efi_status_t
 grub_efi_get_variable (const char *var, const grub_efi_guid_t *guid,
-		       grub_size_t *datasize_out)
+		       grub_size_t *datasize_out, void **data_out)
 {
   grub_efi_status_t status;
   grub_efi_uintn_t datasize = 0;
@@ -233,13 +233,14 @@ grub_efi_get_variable (const char *var, const grub_efi_guid_t *guid,
   void *data;
   grub_size_t len, len16;
 
+  *data_out = NULL;
   *datasize_out = 0;
 
   len = grub_strlen (var);
   len16 = len * GRUB_MAX_UTF16_PER_UTF8;
   var16 = grub_malloc ((len16 + 1) * sizeof (var16[0]));
   if (!var16)
-    return NULL;
+    return GRUB_EFI_OUT_OF_RESOURCES;
   len16 = grub_utf8_to_utf16 (var16, len16, (grub_uint8_t *) var, len, NULL);
   var16[len16] = 0;
 
@@ -250,14 +251,14 @@ grub_efi_get_variable (const char *var, const grub_efi_guid_t *guid,
   if (status != GRUB_EFI_BUFFER_TOO_SMALL || !datasize)
     {
       grub_free (var16);
-      return NULL;
+      return status;
     }
 
   data = grub_malloc (datasize);
   if (!data)
     {
       grub_free (var16);
-      return NULL;
+      return GRUB_EFI_OUT_OF_RESOURCES;
     }
 
   status = efi_call_5 (r->get_variable, var16, guid, NULL, &datasize, data);
@@ -265,12 +266,13 @@ grub_efi_get_variable (const char *var, const grub_efi_guid_t *guid,
 
   if (status == GRUB_EFI_SUCCESS)
     {
+      *data_out = data;
       *datasize_out = datasize;
-      return data;
+      return status;
     }
 
   grub_free (data);
-  return NULL;
+  return status;
 }
 
 #pragma GCC diagnostic ignored "-Wcast-align"
diff --git a/grub-core/video/efi_gop.c b/grub-core/video/efi_gop.c
index be446f8d2..7fe0cdabf 100644
--- a/grub-core/video/efi_gop.c
+++ b/grub-core/video/efi_gop.c
@@ -316,7 +316,7 @@ grub_video_gop_get_edid (struct grub_video_edid_info *edid_info)
       char edidname[] = "agp-internal-edid";
       grub_size_t datasize;
       grub_uint8_t *data;
-      data = grub_efi_get_variable (edidname, &efi_var_guid, &datasize);
+      grub_efi_get_variable (edidname, &efi_var_guid, &datasize, (void **) &data);
       if (data && datasize > 16)
 	{
 	  copy_size = datasize - 16;
diff --git a/include/grub/efi/efi.h b/include/grub/efi/efi.h
index e90e00dc4..8b2a0f1f5 100644
--- a/include/grub/efi/efi.h
+++ b/include/grub/efi/efi.h
@@ -74,9 +74,10 @@ grub_err_t EXPORT_FUNC (grub_efi_set_virtual_address_map) (grub_efi_uintn_t memo
 							   grub_efi_uintn_t descriptor_size,
 							   grub_efi_uint32_t descriptor_version,
 							   grub_efi_memory_descriptor_t *virtual_map);
-void *EXPORT_FUNC (grub_efi_get_variable) (const char *variable,
-					   const grub_efi_guid_t *guid,
-					   grub_size_t *datasize_out);
+grub_efi_status_t EXPORT_FUNC (grub_efi_get_variable) (const char *variable,
+						       const grub_efi_guid_t *guid,
+						       grub_size_t *datasize_out,
+						       void **data_out);
 grub_err_t
 EXPORT_FUNC (grub_efi_set_variable) (const char *var,
 				     const grub_efi_guid_t *guid,
-- 
2.11.0