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Diffstat (limited to 'lib/efi_loader/efi_variable_tee.c')
-rw-r--r--lib/efi_loader/efi_variable_tee.c282
1 files changed, 175 insertions, 107 deletions
diff --git a/lib/efi_loader/efi_variable_tee.c b/lib/efi_loader/efi_variable_tee.c
index cacc76e23db..c0423489388 100644
--- a/lib/efi_loader/efi_variable_tee.c
+++ b/lib/efi_loader/efi_variable_tee.c
@@ -10,6 +10,7 @@
#include <efi.h>
#include <efi_api.h>
#include <efi_loader.h>
+#include <efi_variable.h>
#include <tee.h>
#include <malloc.h>
#include <mm_communication.h>
@@ -243,25 +244,92 @@ out:
return ret;
}
-/**
- * efi_get_variable() - retrieve value of a UEFI variable
- *
- * This function implements the GetVariable runtime service.
- *
- * See the Unified Extensible Firmware Interface (UEFI) specification for
- * details.
- *
- * @name: name of the variable
- * @guid: vendor GUID
- * @attr: attributes of the variable
- * @data_size: size of the buffer to which the variable value is copied
- * @data: buffer to which the variable value is copied
- * Return: status code
+/*
+ * StMM can store internal attributes and properties for variables, i.e enabling
+ * R/O variables
*/
-efi_status_t EFIAPI efi_get_variable(u16 *name, const efi_guid_t *guid,
- u32 *attr, efi_uintn_t *data_size,
- void *data)
+static efi_status_t set_property_int(u16 *variable_name, efi_uintn_t name_size,
+ const efi_guid_t *vendor,
+ struct var_check_property *var_property)
+{
+ struct smm_variable_var_check_property *smm_property;
+ efi_uintn_t payload_size;
+ u8 *comm_buf = NULL;
+ efi_status_t ret;
+
+ payload_size = sizeof(*smm_property) + name_size;
+ if (payload_size > max_payload_size) {
+ ret = EFI_INVALID_PARAMETER;
+ goto out;
+ }
+ comm_buf = setup_mm_hdr((void **)&smm_property, payload_size,
+ SMM_VARIABLE_FUNCTION_VAR_CHECK_VARIABLE_PROPERTY_SET,
+ &ret);
+ if (!comm_buf)
+ goto out;
+
+ guidcpy(&smm_property->guid, vendor);
+ smm_property->name_size = name_size;
+ memcpy(&smm_property->property, var_property,
+ sizeof(smm_property->property));
+ memcpy(smm_property->name, variable_name, name_size);
+
+ ret = mm_communicate(comm_buf, payload_size);
+
+out:
+ free(comm_buf);
+ return ret;
+}
+
+static efi_status_t get_property_int(u16 *variable_name, efi_uintn_t name_size,
+ const efi_guid_t *vendor,
+ struct var_check_property *var_property)
+{
+ struct smm_variable_var_check_property *smm_property;
+ efi_uintn_t payload_size;
+ u8 *comm_buf = NULL;
+ efi_status_t ret;
+
+ memset(var_property, 0, sizeof(*var_property));
+ payload_size = sizeof(*smm_property) + name_size;
+ if (payload_size > max_payload_size) {
+ ret = EFI_INVALID_PARAMETER;
+ goto out;
+ }
+ comm_buf = setup_mm_hdr((void **)&smm_property, payload_size,
+ SMM_VARIABLE_FUNCTION_VAR_CHECK_VARIABLE_PROPERTY_GET,
+ &ret);
+ if (!comm_buf)
+ goto out;
+
+ guidcpy(&smm_property->guid, vendor);
+ smm_property->name_size = name_size;
+ memcpy(smm_property->name, variable_name, name_size);
+
+ ret = mm_communicate(comm_buf, payload_size);
+ /*
+ * Currently only R/O property is supported in StMM.
+ * Variables that are not set to R/O will not set the property in StMM
+ * and the call will return EFI_NOT_FOUND. We are setting the
+ * properties to 0x0 so checking against that is enough for the
+ * EFI_NOT_FOUND case.
+ */
+ if (ret == EFI_NOT_FOUND)
+ ret = EFI_SUCCESS;
+ if (ret != EFI_SUCCESS)
+ goto out;
+ memcpy(var_property, &smm_property->property, sizeof(*var_property));
+
+out:
+ free(comm_buf);
+ return ret;
+}
+
+efi_status_t efi_get_variable_int(u16 *variable_name, const efi_guid_t *vendor,
+ u32 *attributes, efi_uintn_t *data_size,
+ void *data, u64 *timep)
{
+ struct var_check_property var_property;
struct smm_variable_access *var_acc;
efi_uintn_t payload_size;
efi_uintn_t name_size;
@@ -269,15 +337,13 @@ efi_status_t EFIAPI efi_get_variable(u16 *name, const efi_guid_t *guid,
u8 *comm_buf = NULL;
efi_status_t ret;
- EFI_ENTRY("\"%ls\" %pUl %p %p %p", name, guid, attr, data_size, data);
-
- if (!name || !guid || !data_size) {
+ if (!variable_name || !vendor || !data_size) {
ret = EFI_INVALID_PARAMETER;
goto out;
}
/* Check payload size */
- name_size = u16_strsize(name);
+ name_size = u16_strsize(variable_name);
if (name_size > max_payload_size - MM_VARIABLE_ACCESS_HEADER_SIZE) {
ret = EFI_INVALID_PARAMETER;
goto out;
@@ -300,11 +366,11 @@ efi_status_t EFIAPI efi_get_variable(u16 *name, const efi_guid_t *guid,
goto out;
/* Fill in contents */
- guidcpy(&var_acc->guid, guid);
+ guidcpy(&var_acc->guid, vendor);
var_acc->data_size = tmp_dsize;
var_acc->name_size = name_size;
- var_acc->attr = attr ? *attr : 0;
- memcpy(var_acc->name, name, name_size);
+ var_acc->attr = attributes ? *attributes : 0;
+ memcpy(var_acc->name, variable_name, name_size);
/* Communicate */
ret = mm_communicate(comm_buf, payload_size);
@@ -315,8 +381,16 @@ efi_status_t EFIAPI efi_get_variable(u16 *name, const efi_guid_t *guid,
if (ret != EFI_SUCCESS)
goto out;
- if (attr)
- *attr = var_acc->attr;
+ ret = get_property_int(variable_name, name_size, vendor, &var_property);
+ if (ret != EFI_SUCCESS)
+ goto out;
+
+ if (attributes) {
+ *attributes = var_acc->attr;
+ if (var_property.property & VAR_CHECK_VARIABLE_PROPERTY_READ_ONLY)
+ *attributes |= EFI_VARIABLE_READ_ONLY;
+ }
+
if (data)
memcpy(data, (u8 *)var_acc->name + var_acc->name_size,
var_acc->data_size);
@@ -325,38 +399,21 @@ efi_status_t EFIAPI efi_get_variable(u16 *name, const efi_guid_t *guid,
out:
free(comm_buf);
- return EFI_EXIT(ret);
+ return ret;
}
-/**
- * efi_get_next_variable_name() - enumerate the current variable names
- *
- * @variable_name_size: size of variable_name buffer in bytes
- * @variable_name: name of uefi variable's name in u16
- * @guid: vendor's guid
- *
- * This function implements the GetNextVariableName service.
- *
- * See the Unified Extensible Firmware Interface (UEFI) specification for
- * details.
- *
- * Return: status code
- */
-efi_status_t EFIAPI efi_get_next_variable_name(efi_uintn_t *variable_name_size,
- u16 *variable_name,
- efi_guid_t *guid)
+efi_status_t efi_get_next_variable_name_int(efi_uintn_t *variable_name_size,
+ u16 *variable_name,
+ efi_guid_t *guid)
{
struct smm_variable_getnext *var_getnext;
efi_uintn_t payload_size;
efi_uintn_t out_name_size;
efi_uintn_t in_name_size;
efi_uintn_t tmp_dsize;
- efi_uintn_t name_size;
u8 *comm_buf = NULL;
efi_status_t ret;
- EFI_ENTRY("%p \"%ls\" %pUl", variable_name_size, variable_name, guid);
-
if (!variable_name_size || !variable_name || !guid) {
ret = EFI_INVALID_PARAMETER;
goto out;
@@ -370,19 +427,18 @@ efi_status_t EFIAPI efi_get_next_variable_name(efi_uintn_t *variable_name_size,
goto out;
}
- name_size = u16_strsize(variable_name);
- if (name_size > max_payload_size - MM_VARIABLE_GET_NEXT_HEADER_SIZE) {
+ if (in_name_size > max_payload_size - MM_VARIABLE_GET_NEXT_HEADER_SIZE) {
ret = EFI_INVALID_PARAMETER;
goto out;
}
/* Trim output buffer size */
tmp_dsize = *variable_name_size;
- if (name_size + tmp_dsize >
+ if (in_name_size + tmp_dsize >
max_payload_size - MM_VARIABLE_GET_NEXT_HEADER_SIZE) {
tmp_dsize = max_payload_size -
MM_VARIABLE_GET_NEXT_HEADER_SIZE -
- name_size;
+ in_name_size;
}
payload_size = MM_VARIABLE_GET_NEXT_HEADER_SIZE + out_name_size;
@@ -414,37 +470,22 @@ efi_status_t EFIAPI efi_get_next_variable_name(efi_uintn_t *variable_name_size,
out:
free(comm_buf);
- return EFI_EXIT(ret);
+ return ret;
}
-/**
- * efi_set_variable() - set value of a UEFI variable
- *
- * This function implements the SetVariable runtime service.
- *
- * See the Unified Extensible Firmware Interface (UEFI) specification for
- * details.
- *
- * @name: name of the variable
- * @guid: vendor GUID
- * @attr: attributes of the variable
- * @data_size: size of the buffer with the variable value
- * @data: buffer with the variable value
- * Return: status code
- */
-efi_status_t EFIAPI efi_set_variable(u16 *name, const efi_guid_t *guid,
- u32 attr, efi_uintn_t data_size,
- const void *data)
+efi_status_t efi_set_variable_int(u16 *variable_name, const efi_guid_t *vendor,
+ u32 attributes, efi_uintn_t data_size,
+ const void *data, bool ro_check)
{
+ efi_status_t ret, alt_ret = EFI_SUCCESS;
+ struct var_check_property var_property;
struct smm_variable_access *var_acc;
efi_uintn_t payload_size;
efi_uintn_t name_size;
u8 *comm_buf = NULL;
- efi_status_t ret;
+ bool ro;
- EFI_ENTRY("\"%ls\" %pUl %x %zu %p", name, guid, attr, data_size, data);
-
- if (!name || name[0] == 0 || !guid) {
+ if (!variable_name || variable_name[0] == 0 || !vendor) {
ret = EFI_INVALID_PARAMETER;
goto out;
}
@@ -452,68 +493,91 @@ efi_status_t EFIAPI efi_set_variable(u16 *name, const efi_guid_t *guid,
ret = EFI_INVALID_PARAMETER;
goto out;
}
-
/* Check payload size */
- name_size = u16_strsize(name);
+ name_size = u16_strsize(variable_name);
payload_size = MM_VARIABLE_ACCESS_HEADER_SIZE + name_size + data_size;
if (payload_size > max_payload_size) {
ret = EFI_INVALID_PARAMETER;
goto out;
}
- /* Get communication buffer and initialize header */
+ /*
+ * Allocate the buffer early, before switching to RW (if needed)
+ * so we won't need to account for any failures in reading/setting
+ * the properties, if the allocation fails
+ */
comm_buf = setup_mm_hdr((void **)&var_acc, payload_size,
SMM_VARIABLE_FUNCTION_SET_VARIABLE, &ret);
if (!comm_buf)
goto out;
+ ro = !!(attributes & EFI_VARIABLE_READ_ONLY);
+ attributes &= EFI_VARIABLE_MASK;
+
+ /*
+ * The API has the ability to override RO flags. If no RO check was
+ * requested switch the variable to RW for the duration of this call
+ */
+ ret = get_property_int(variable_name, name_size, vendor,
+ &var_property);
+ if (ret != EFI_SUCCESS)
+ goto out;
+
+ if (var_property.property & VAR_CHECK_VARIABLE_PROPERTY_READ_ONLY) {
+ /* Bypass r/o check */
+ if (!ro_check) {
+ var_property.property &= ~VAR_CHECK_VARIABLE_PROPERTY_READ_ONLY;
+ ret = set_property_int(variable_name, name_size, vendor, &var_property);
+ if (ret != EFI_SUCCESS)
+ goto out;
+ } else {
+ ret = EFI_WRITE_PROTECTED;
+ goto out;
+ }
+ }
+
/* Fill in contents */
- guidcpy(&var_acc->guid, guid);
+ guidcpy(&var_acc->guid, vendor);
var_acc->data_size = data_size;
var_acc->name_size = name_size;
- var_acc->attr = attr;
- memcpy(var_acc->name, name, name_size);
+ var_acc->attr = attributes;
+ memcpy(var_acc->name, variable_name, name_size);
memcpy((u8 *)var_acc->name + name_size, data, data_size);
/* Communicate */
ret = mm_communicate(comm_buf, payload_size);
+ if (ret != EFI_SUCCESS)
+ alt_ret = ret;
+
+ if (ro && !(var_property.property & VAR_CHECK_VARIABLE_PROPERTY_READ_ONLY)) {
+ var_property.revision = VAR_CHECK_VARIABLE_PROPERTY_REVISION;
+ var_property.property |= VAR_CHECK_VARIABLE_PROPERTY_READ_ONLY;
+ var_property.attributes = attributes;
+ var_property.minsize = 1;
+ var_property.maxsize = var_acc->data_size;
+ ret = set_property_int(variable_name, name_size, vendor, &var_property);
+ }
+ if (alt_ret != EFI_SUCCESS)
+ goto out;
+
+ if (!u16_strcmp(variable_name, L"PK"))
+ alt_ret = efi_init_secure_state();
out:
free(comm_buf);
- return EFI_EXIT(ret);
+ return alt_ret == EFI_SUCCESS ? ret : alt_ret;
}
-/**
- * efi_query_variable_info() - get information about EFI variables
- *
- * This function implements the QueryVariableInfo() runtime service.
- *
- * See the Unified Extensible Firmware Interface (UEFI) specification for
- * details.
- *
- * @attributes: bitmask to select variables to be
- * queried
- * @maximum_variable_storage_size: maximum size of storage area for the
- * selected variable types
- * @remaining_variable_storage_size: remaining size of storage are for the
- * selected variable types
- * @maximum_variable_size: maximum size of a variable of the
- * selected type
- * Returns: status code
- */
-efi_status_t EFIAPI __efi_runtime
-efi_query_variable_info(u32 attributes, u64 *max_variable_storage_size,
- u64 *remain_variable_storage_size,
- u64 *max_variable_size)
+efi_status_t efi_query_variable_info_int(u32 attributes,
+ u64 *max_variable_storage_size,
+ u64 *remain_variable_storage_size,
+ u64 *max_variable_size)
{
struct smm_variable_query_info *mm_query_info;
efi_uintn_t payload_size;
efi_status_t ret;
u8 *comm_buf;
- EFI_ENTRY("%x %p %p %p", attributes, max_variable_storage_size,
- remain_variable_storage_size, max_variable_size);
-
payload_size = sizeof(*mm_query_info);
comm_buf = setup_mm_hdr((void **)&mm_query_info, payload_size,
SMM_VARIABLE_FUNCTION_QUERY_VARIABLE_INFO,
@@ -532,7 +596,7 @@ efi_query_variable_info(u32 attributes, u64 *max_variable_storage_size,
out:
free(comm_buf);
- return EFI_EXIT(ret);
+ return ret;
}
/**
@@ -658,5 +722,9 @@ efi_status_t efi_init_variables(void)
MM_VARIABLE_COMMUNICATE_SIZE +
max_payload_size;
+ ret = efi_init_secure_state();
+ if (ret != EFI_SUCCESS)
+ return ret;
+
return EFI_SUCCESS;
}
generated by cgit v1.2.3 (git 2.0.4) at 2025-07-30 13:25:35 +0000