[PATCH v2 1/3] efi_var_file: refactor to move buffer functions
Shantur Rathore
i at shantur.com
Fri Nov 24 12:35:50 CET 2023
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 at shantur.com>
---
(no changes since v1)
include/efi_variable.h | 5 ++
lib/efi_loader/Makefile | 2 +-
lib/efi_loader/efi_var_common.c | 109 ++++++++++++++++++++++++++++
lib/efi_loader/efi_var_file.c | 121 --------------------------------
lib/efi_loader/efi_variable.c | 8 ++-
5 files changed, 122 insertions(+), 123 deletions(-)
diff --git a/include/efi_variable.h b/include/efi_variable.h
index 805e6c5f1e..bd0a31fc3e 100644
--- 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 8d31fc61c6..33b1910249 100644
--- a/lib/efi_loader/Makefile
+++ b/lib/efi_loader/Makefile
@@ -66,7 +66,7 @@ obj-y += efi_string.o
obj-$(CONFIG_EFI_UNICODE_COLLATION_PROTOCOL2) += efi_unicode_collation.o
obj-y += efi_var_common.o
obj-y += efi_var_mem.o
-obj-y += efi_var_file.o
+obj-$(CONFIG_EFI_VARIABLE_FILE_STORE) += efi_var_file.o
ifeq ($(CONFIG_EFI_MM_COMM_TEE),y)
obj-y += efi_variable_tee.o
else
diff --git a/lib/efi_loader/efi_var_common.c b/lib/efi_loader/efi_var_common.c
index ad50bffd2b..7509c30b5a 100644
--- a/lib/efi_loader/efi_var_common.c
+++ b/lib/efi_loader/efi_var_common.c
@@ -10,6 +10,7 @@
#include <efi_loader.h>
#include <efi_variable.h>
#include <stdlib.h>
+#include <u-boot/crc.h>
enum efi_secure_mode {
EFI_MODE_SETUP,
@@ -40,6 +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
@@ -417,3 +419,110 @@ void *efi_get_var(const u16 *name, const efi_guid_t *vendor, efi_uintn_t *size)
return buf;
}
+
+efi_status_t __maybe_unused efi_var_collect(struct efi_var_file **bufp, loff_t *lenp,
+ u32 check_attr_mask)
+{
+ size_t len = EFI_VAR_BUF_SIZE;
+ struct efi_var_file *buf;
+ struct efi_var_entry *var, *old_var;
+ size_t old_var_name_length = 2;
+
+ *bufp = NULL; /* Avoid double free() */
+ buf = calloc(1, len);
+ if (!buf)
+ return EFI_OUT_OF_RESOURCES;
+ var = buf->var;
+ old_var = var;
+ for (;;) {
+ efi_uintn_t data_length, var_name_length;
+ u8 *data;
+ efi_status_t ret;
+
+ if ((uintptr_t)buf + len <=
+ (uintptr_t)var->name + old_var_name_length)
+ return EFI_BUFFER_TOO_SMALL;
+
+ var_name_length = (uintptr_t)buf + len - (uintptr_t)var->name;
+ memcpy(var->name, old_var->name, old_var_name_length);
+ guidcpy(&var->guid, &old_var->guid);
+ ret = efi_get_next_variable_name_int(
+ &var_name_length, var->name, &var->guid);
+ if (ret == EFI_NOT_FOUND)
+ break;
+ if (ret != EFI_SUCCESS) {
+ free(buf);
+ return ret;
+ }
+ old_var_name_length = var_name_length;
+ old_var = var;
+
+ data = (u8 *)var->name + old_var_name_length;
+ data_length = (uintptr_t)buf + len - (uintptr_t)data;
+ ret = efi_get_variable_int(var->name, &var->guid,
+ &var->attr, &data_length, data,
+ &var->time);
+ if (ret != EFI_SUCCESS) {
+ free(buf);
+ return ret;
+ }
+ if ((var->attr & check_attr_mask) == check_attr_mask) {
+ var->length = data_length;
+ var = (struct efi_var_entry *)ALIGN((uintptr_t)data + data_length, 8);
+ }
+ }
+
+ buf->reserved = 0;
+ buf->magic = EFI_VAR_FILE_MAGIC;
+ len = (uintptr_t)var - (uintptr_t)buf;
+ buf->crc32 = crc32(0, (u8 *)buf->var,
+ len - sizeof(struct efi_var_file));
+ buf->length = len;
+ *bufp = buf;
+ *lenp = len;
+
+ 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 d7dba05071..166501a355 100644
--- a/lib/efi_loader/efi_var_file.c
+++ b/lib/efi_loader/efi_var_file.c
@@ -15,17 +15,9 @@
#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
*
@@ -53,70 +45,6 @@ static efi_status_t __maybe_unused efi_set_blk_dev_to_system_partition(void)
return EFI_SUCCESS;
}
-efi_status_t __maybe_unused efi_var_collect(struct efi_var_file **bufp, loff_t *lenp,
- u32 check_attr_mask)
-{
- size_t len = EFI_VAR_BUF_SIZE;
- struct efi_var_file *buf;
- struct efi_var_entry *var, *old_var;
- size_t old_var_name_length = 2;
-
- *bufp = NULL; /* Avoid double free() */
- buf = calloc(1, len);
- if (!buf)
- return EFI_OUT_OF_RESOURCES;
- var = buf->var;
- old_var = var;
- for (;;) {
- efi_uintn_t data_length, var_name_length;
- u8 *data;
- efi_status_t ret;
-
- if ((uintptr_t)buf + len <=
- (uintptr_t)var->name + old_var_name_length)
- return EFI_BUFFER_TOO_SMALL;
-
- var_name_length = (uintptr_t)buf + len - (uintptr_t)var->name;
- memcpy(var->name, old_var->name, old_var_name_length);
- guidcpy(&var->guid, &old_var->guid);
- ret = efi_get_next_variable_name_int(
- &var_name_length, var->name, &var->guid);
- if (ret == EFI_NOT_FOUND)
- break;
- if (ret != EFI_SUCCESS) {
- free(buf);
- return ret;
- }
- old_var_name_length = var_name_length;
- old_var = var;
-
- data = (u8 *)var->name + old_var_name_length;
- data_length = (uintptr_t)buf + len - (uintptr_t)data;
- ret = efi_get_variable_int(var->name, &var->guid,
- &var->attr, &data_length, data,
- &var->time);
- if (ret != EFI_SUCCESS) {
- free(buf);
- return ret;
- }
- if ((var->attr & check_attr_mask) == check_attr_mask) {
- var->length = data_length;
- var = (struct efi_var_entry *)ALIGN((uintptr_t)data + data_length, 8);
- }
- }
-
- buf->reserved = 0;
- buf->magic = EFI_VAR_FILE_MAGIC;
- len = (uintptr_t)var - (uintptr_t)buf;
- buf->crc32 = crc32(0, (u8 *)buf->var,
- len - sizeof(struct efi_var_file));
- buf->length = len;
- *bufp = buf;
- *lenp = len;
-
- return EFI_SUCCESS;
-}
-
/**
* efi_var_to_file() - save non-volatile variables as file
*
@@ -126,7 +54,6 @@ efi_status_t __maybe_unused efi_var_collect(struct efi_var_file **bufp, loff_t *
*/
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;
@@ -150,52 +77,6 @@ error:
log_err("Failed to persist EFI variables\n");
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;
}
/**
@@ -214,7 +95,6 @@ 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;
@@ -239,6 +119,5 @@ 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 be95ed44e6..adc5ac6a80 100644
--- a/lib/efi_loader/efi_variable.c
+++ b/lib/efi_loader/efi_variable.c
@@ -357,8 +357,11 @@ efi_status_t efi_set_variable_int(const u16 *variable_name,
* Write non-volatile EFI variables to file
* TODO: check if a value change has occured to avoid superfluous writes
*/
- if (attributes & EFI_VARIABLE_NON_VOLATILE)
+#if CONFIG_IS_ENABLED(EFI_VARIABLE_FILE_STORE)
+ if (attributes & EFI_VARIABLE_NON_VOLATILE) {
efi_var_to_file();
+ }
+#endif
return EFI_SUCCESS;
}
@@ -466,9 +469,12 @@ efi_status_t efi_init_variables(void)
if (ret != EFI_SUCCESS)
return ret;
+#if CONFIG_IS_ENABLED(EFI_VARIABLE_FILE_STORE)
ret = efi_var_from_file();
if (ret != EFI_SUCCESS)
return ret;
+#endif
+
if (IS_ENABLED(CONFIG_EFI_VARIABLES_PRESEED)) {
ret = efi_var_restore((struct efi_var_file *)
__efi_var_file_begin, true);
--
2.40.1
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