efi_var_file: refactor to move buffer functions

Currently efi_var_file.c has functions to store/read
EFI variables to/from memory buffer. These functions
can be used with other EFI variable stores so move
them out to efi_var_common.c

Signed-off-by: Shantur Rathore <i@shantur.com>
Signed-off-by: Michal Simek <michal.simek@amd.com>
Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on AML-S905D3-CC
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Reviewed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>

diff --git a/include/efi_variable.h b/include/efi_variable.h
index 4065cf45ecafafaa36c0a718da6bdc3ddd0b89c8..ee68fa4a885fe7d12ab40ea46dde61a6721cc0dc 100644 (file)
--- a/include/efi_variable.h
+++ b/include/efi_variable.h
@@ -161,6 +161,11 @@ efi_status_t efi_var_to_file(void);
 efi_status_t __maybe_unused efi_var_collect(struct efi_var_file **bufp, loff_t *lenp,
                                            u32 check_attr_mask);
 
+/* GUID used by Shim to store the MOK database */
+#define SHIM_LOCK_GUID \
+       EFI_GUID(0x605dab50, 0xe046, 0x4300, \
+                0xab, 0xb6, 0x3d, 0xd8, 0x10, 0xdd, 0x8b, 0x23)
+
 /**
  * efi_var_restore() - restore EFI variables from buffer
  *

diff --git a/lib/efi_loader/Makefile b/lib/efi_loader/Makefile
index f490081f6542a5b22f7fe2eb656cf57b55726250..ca1775eb03bea5a2bf165e2e45432803397a5125 100644 (file)
--- a/lib/efi_loader/Makefile
+++ b/lib/efi_loader/Makefile
@@ -53,7 +53,7 @@ ifeq ($(CONFIG_EFI_MM_COMM_TEE),y)
 obj-y += efi_variable_tee.o
 else
 obj-y += efi_variable.o
-obj-y += efi_var_file.o
+obj-$(CONFIG_EFI_VARIABLE_FILE_STORE) += efi_var_file.o
 obj-$(CONFIG_EFI_VARIABLES_PRESEED) += efi_var_seed.o
 endif
 obj-y += efi_watchdog.o

diff --git a/lib/efi_loader/efi_var_common.c b/lib/efi_loader/efi_var_common.c
index 4b34a58b4cf734e578898591270beab52015c45d..5ea1688dca3dcdc81c911fc87a1cd4459331ec28 100644 (file)
--- a/lib/efi_loader/efi_var_common.c
+++ b/lib/efi_loader/efi_var_common.c
@@ -41,6 +41,7 @@ static const struct efi_auth_var_name_type name_type[] = {
 
 static bool efi_secure_boot;
 static enum efi_secure_mode efi_secure_mode;
+static const efi_guid_t shim_lock_guid = SHIM_LOCK_GUID;
 
 /**
  * efi_efi_get_variable() - retrieve value of a UEFI variable
@@ -488,3 +489,44 @@ efi_status_t __maybe_unused efi_var_collect(struct efi_var_file **bufp, loff_t *
 
        return EFI_SUCCESS;
 }
+
+efi_status_t efi_var_restore(struct efi_var_file *buf, bool safe)
+{
+       struct efi_var_entry *var, *last_var;
+       u16 *data;
+       efi_status_t ret;
+
+       if (buf->reserved || buf->magic != EFI_VAR_FILE_MAGIC ||
+           buf->crc32 != crc32(0, (u8 *)buf->var,
+                               buf->length - sizeof(struct efi_var_file))) {
+               log_err("Invalid EFI variables file\n");
+               return EFI_INVALID_PARAMETER;
+       }
+
+       last_var = (struct efi_var_entry *)((u8 *)buf + buf->length);
+       for (var = buf->var; var < last_var;
+            var = (struct efi_var_entry *)ALIGN((uintptr_t)data + var->length, 8)) {
+               data = var->name + u16_strlen(var->name) + 1;
+
+               /*
+                * Secure boot related and volatile variables shall only be
+                * restored from U-Boot's preseed.
+                */
+               if (!safe &&
+                   (efi_auth_var_get_type(var->name, &var->guid) !=
+                    EFI_AUTH_VAR_NONE ||
+                    !guidcmp(&var->guid, &shim_lock_guid) ||
+                    !(var->attr & EFI_VARIABLE_NON_VOLATILE)))
+                       continue;
+               if (!var->length)
+                       continue;
+               if (efi_var_mem_find(&var->guid, var->name, NULL))
+                       continue;
+               ret = efi_var_mem_ins(var->name, &var->guid, var->attr,
+                                     var->length, data, 0, NULL,
+                                     var->time);
+               if (ret != EFI_SUCCESS)
+                       log_err("Failed to set EFI variable %ls\n", var->name);
+       }
+       return EFI_SUCCESS;
+}

diff --git a/lib/efi_loader/efi_var_file.c b/lib/efi_loader/efi_var_file.c
index f23a964a4180cf1fbfd9c8fa0a79279593b0a537..4061a463b5805bfe73f8c8ece39fce88b3a42b48 100644 (file)
--- a/lib/efi_loader/efi_var_file.c
+++ b/lib/efi_loader/efi_var_file.c
@@ -14,17 +14,9 @@
 #include <mapmem.h>
 #include <efi_loader.h>
 #include <efi_variable.h>
-#include <u-boot/crc.h>
 
 #define PART_STR_LEN 10
 
-/* GUID used by Shim to store the MOK database */
-#define SHIM_LOCK_GUID \
-       EFI_GUID(0x605dab50, 0xe046, 0x4300, \
-                0xab, 0xb6, 0x3d, 0xd8, 0x10, 0xdd, 0x8b, 0x23)
-
-static const efi_guid_t shim_lock_guid = SHIM_LOCK_GUID;
-
 /**
  * efi_set_blk_dev_to_system_partition() - select EFI system partition
  *
@@ -59,7 +51,6 @@ static efi_status_t __maybe_unused efi_set_blk_dev_to_system_partition(void)
  */
 efi_status_t efi_var_to_file(void)
 {
-#ifdef CONFIG_EFI_VARIABLE_FILE_STORE
        efi_status_t ret;
        struct efi_var_file *buf;
        loff_t len;
@@ -91,52 +82,6 @@ error:
 out:
        free(buf);
        return ret;
-#else
-       return EFI_SUCCESS;
-#endif
-}
-
-efi_status_t efi_var_restore(struct efi_var_file *buf, bool safe)
-{
-       struct efi_var_entry *var, *last_var;
-       u16 *data;
-       efi_status_t ret;
-
-       if (buf->reserved || buf->magic != EFI_VAR_FILE_MAGIC ||
-           buf->crc32 != crc32(0, (u8 *)buf->var,
-                               buf->length - sizeof(struct efi_var_file))) {
-               log_err("Invalid EFI variables file\n");
-               return EFI_INVALID_PARAMETER;
-       }
-
-       last_var = (struct efi_var_entry *)((u8 *)buf + buf->length);
-       for (var = buf->var; var < last_var;
-            var = (struct efi_var_entry *)
-                  ALIGN((uintptr_t)data + var->length, 8)) {
-
-               data = var->name + u16_strlen(var->name) + 1;
-
-               /*
-                * Secure boot related and volatile variables shall only be
-                * restored from U-Boot's preseed.
-                */
-               if (!safe &&
-                   (efi_auth_var_get_type(var->name, &var->guid) !=
-                    EFI_AUTH_VAR_NONE ||
-                    !guidcmp(&var->guid, &shim_lock_guid) ||
-                    !(var->attr & EFI_VARIABLE_NON_VOLATILE)))
-                       continue;
-               if (!var->length)
-                       continue;
-               if (efi_var_mem_find(&var->guid, var->name, NULL))
-                       continue;
-               ret = efi_var_mem_ins(var->name, &var->guid, var->attr,
-                                     var->length, data, 0, NULL,
-                                     var->time);
-               if (ret != EFI_SUCCESS)
-                       log_err("Failed to set EFI variable %ls\n", var->name);
-       }
-       return EFI_SUCCESS;
 }
 
 /**
@@ -155,7 +100,6 @@ efi_status_t efi_var_restore(struct efi_var_file *buf, bool safe)
  */
 efi_status_t efi_var_from_file(void)
 {
-#ifdef CONFIG_EFI_VARIABLE_FILE_STORE
        struct efi_var_file *buf;
        loff_t len;
        efi_status_t ret;
@@ -180,6 +124,5 @@ efi_status_t efi_var_from_file(void)
                log_err("Invalid EFI variables file\n");
 error:
        free(buf);
-#endif
        return EFI_SUCCESS;
 }

diff --git a/lib/efi_loader/efi_variable.c b/lib/efi_loader/efi_variable.c
index f3533f4def3ae7bc9af9e180e6a7c4a69f2a8080..6e45134c61bf95f84e07df283ac38e7ae5d9a842 100644 (file)
--- a/lib/efi_loader/efi_variable.c
+++ b/lib/efi_loader/efi_variable.c
@@ -397,11 +397,15 @@ efi_status_t efi_set_variable_int(const u16 *variable_name,
                ret = EFI_SUCCESS;
 
        /*
-        * Write non-volatile EFI variables to file
+        * Write non-volatile EFI variables
         * TODO: check if a value change has occured to avoid superfluous writes
         */
-       if (attributes & EFI_VARIABLE_NON_VOLATILE)
+       if (attributes & EFI_VARIABLE_NON_VOLATILE) {
+               if (IS_ENABLED(CONFIG_EFI_VARIABLE_NO_STORE))
+                       return EFI_SUCCESS;
+
                efi_var_to_file();
+       }
 
        return EFI_SUCCESS;
 }
@@ -594,9 +598,12 @@ efi_status_t efi_init_variables(void)
        if (ret != EFI_SUCCESS)
                return ret;
 
-       ret = efi_var_from_file();
-       if (ret != EFI_SUCCESS)
-               return ret;
+       if (!IS_ENABLED(CONFIG_EFI_VARIABLE_NO_STORE)) {
+               ret = efi_var_from_file();
+               if (ret != EFI_SUCCESS)
+                       return ret;
+       }
+
        if (IS_ENABLED(CONFIG_EFI_VARIABLES_PRESEED)) {
                ret = efi_var_restore((struct efi_var_file *)
                                      __efi_var_file_begin, true);