Merge tag 'efi-2020-10-rc1-3' of https://gitlab.denx.de/u-boot/custodians/u-boot-efi

Pull request for UEFI sub-system for efi-2020-10-rc1 (3)

Up to now UEFI variables where stored in U-Boot environment variables.
Saving UEFI variables was not possible without saving the U-Boot
environment variables. With this patch series file ubootefi.var in the
EFI system partition is used for saving UEFI variables. Furthermore the
UEFI variables are exposed for reading at runtime.

Code corrections for UEFI secure boot are provided.

A buffer overrun in the RSA library is fixed.

1 files changed, 266 insertions, 0 deletions

diff --git a/lib/efi_loader/efi_var_mem.c b/lib/efi_loader/efi_var_mem.c
new file mode 100644
index 0000000000..7a2dba7dc2
--- /dev/null
+++ b/lib/efi_loader/efi_var_mem.c
@@ -0,0 +1,266 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * File interface for UEFI variables
+ *
+ * Copyright (c) 2020, Heinrich Schuchardt
+ */
+
+#include <common.h>
+#include <efi_loader.h>
+#include <efi_variable.h>
+#include <u-boot/crc.h>
+
+static struct efi_var_file __efi_runtime_data *efi_var_buf;
+static struct efi_var_entry __efi_runtime_data *efi_current_var;
+
+/**
+ * efi_var_mem_compare() - compare GUID and name with a variable
+ *
+ * @var:	variable to compare
+ * @guid:	GUID to compare
+ * @name:	variable name to compare
+ * @next:	pointer to next variable
+ * Return:	true if match
+ */
+static bool __efi_runtime
+efi_var_mem_compare(struct efi_var_entry *var, const efi_guid_t *guid,
+		    const u16 *name, struct efi_var_entry **next)
+{
+	int i;
+	u8 *guid1, *guid2;
+	const u16 *data, *var_name;
+	bool match = true;
+
+	for (guid1 = (u8 *)&var->guid, guid2 = (u8 *)guid, i = 0;
+	     i < sizeof(efi_guid_t) && match; ++i)
+		match = (guid1[i] == guid2[i]);
+
+	for (data = var->name, var_name = name;; ++data, ++var_name) {
+		if (match)
+			match = (*data == *var_name);
+		if (!*data)
+			break;
+	}
+
+	++data;
+
+	if (next)
+		*next = (struct efi_var_entry *)
+			ALIGN((uintptr_t)data + var->length, 8);
+
+	if (match)
+		efi_current_var = var;
+
+	return match;
+}
+
+struct efi_var_entry __efi_runtime
+*efi_var_mem_find(const efi_guid_t *guid, const u16 *name,
+		  struct efi_var_entry **next)
+{
+	struct efi_var_entry *var, *last;
+
+	last = (struct efi_var_entry *)
+	       ((uintptr_t)efi_var_buf + efi_var_buf->length);
+
+	if (!*name) {
+		if (next) {
+			*next = efi_var_buf->var;
+			if (*next >= last)
+				*next = NULL;
+		}
+		return NULL;
+	}
+	if (efi_current_var &&
+	    efi_var_mem_compare(efi_current_var, guid, name, next)) {
+		if (next && *next >= last)
+			*next = NULL;
+		return efi_current_var;
+	}
+
+	var = efi_var_buf->var;
+	if (var < last) {
+		for (; var;) {
+			struct efi_var_entry *pos;
+			bool match;
+
+			match = efi_var_mem_compare(var, guid, name, &pos);
+			if (pos >= last)
+				pos = NULL;
+			if (match) {
+				if (next)
+					*next = pos;
+				return var;
+			}
+			var = pos;
+		}
+	}
+	if (next)
+		*next = NULL;
+	return NULL;
+}
+
+void __efi_runtime efi_var_mem_del(struct efi_var_entry *var)
+{
+	u16 *data;
+	struct efi_var_entry *next, *last;
+
+	if (!var)
+		return;
+
+	last = (struct efi_var_entry *)
+	       ((uintptr_t)efi_var_buf + efi_var_buf->length);
+	if (var <= efi_current_var)
+		efi_current_var = NULL;
+
+	for (data = var->name; *data; ++data)
+		;
+	++data;
+	next = (struct efi_var_entry *)
+	       ALIGN((uintptr_t)data + var->length, 8);
+	efi_var_buf->length -= (uintptr_t)next - (uintptr_t)var;
+
+	memmove(var, next, (uintptr_t)last - (uintptr_t)next);
+	efi_var_buf->crc32 = crc32(0, (u8 *)efi_var_buf->var,
+				   efi_var_buf->length -
+				   sizeof(struct efi_var_file));
+}
+
+efi_status_t __efi_runtime efi_var_mem_ins(
+				u16 *variable_name,
+				const efi_guid_t *vendor, u32 attributes,
+				const efi_uintn_t size1, const void *data1,
+				const efi_uintn_t size2, const void *data2,
+				const u64 time)
+{
+	u16 *data;
+	struct efi_var_entry *var;
+	u32 var_name_len;
+
+	var = (struct efi_var_entry *)
+	      ((uintptr_t)efi_var_buf + efi_var_buf->length);
+	for (var_name_len = 0; variable_name[var_name_len]; ++var_name_len)
+		;
+	++var_name_len;
+	data = var->name + var_name_len;
+
+	if ((uintptr_t)data - (uintptr_t)efi_var_buf + size1 + size2 >
+	    EFI_VAR_BUF_SIZE)
+		return EFI_OUT_OF_RESOURCES;
+
+	var->attr = attributes;
+	var->length = size1 + size2;
+	var->time = time;
+
+	efi_memcpy_runtime(&var->guid, vendor, sizeof(efi_guid_t));
+	efi_memcpy_runtime(var->name, variable_name,
+			   sizeof(u16) * var_name_len);
+	efi_memcpy_runtime(data, data1, size1);
+	efi_memcpy_runtime((u8 *)data + size1, data2, size2);
+
+	var = (struct efi_var_entry *)
+	      ALIGN((uintptr_t)data + var->length, 8);
+	efi_var_buf->length = (uintptr_t)var - (uintptr_t)efi_var_buf;
+	efi_var_buf->crc32 = crc32(0, (u8 *)efi_var_buf->var,
+				   efi_var_buf->length -
+				   sizeof(struct efi_var_file));
+
+	return EFI_SUCCESS;
+}
+
+u64 __efi_runtime efi_var_mem_free(void)
+{
+	return EFI_VAR_BUF_SIZE - efi_var_buf->length -
+	       sizeof(struct efi_var_entry);
+}
+
+/**
+ * efi_var_mem_bs_del() - delete boot service only variables
+ */
+static void efi_var_mem_bs_del(void)
+{
+	struct efi_var_entry *var = efi_var_buf->var;
+
+	for (;;) {
+		struct efi_var_entry *last;
+
+		last = (struct efi_var_entry *)
+		       ((uintptr_t)efi_var_buf + efi_var_buf->length);
+		if (var >= last)
+			break;
+		if (var->attr & EFI_VARIABLE_RUNTIME_ACCESS) {
+			u16 *data;
+
+			/* skip variable */
+			for (data = var->name; *data; ++data)
+				;
+			++data;
+			var = (struct efi_var_entry *)
+			      ALIGN((uintptr_t)data + var->length, 8);
+		} else {
+			/* delete variable */
+			efi_var_mem_del(var);
+		}
+	}
+}
+
+/**
+ * efi_var_mem_notify_exit_boot_services() - ExitBootService callback
+ *
+ * @event:	callback event
+ * @context:	callback context
+ */
+static void EFIAPI __efi_runtime
+efi_var_mem_notify_exit_boot_services(struct efi_event *event, void *context)
+{
+	EFI_ENTRY("%p, %p", event, context);
+
+	/* Delete boot service only variables */
+	efi_var_mem_bs_del();
+
+	EFI_EXIT(EFI_SUCCESS);
+}
+
+/**
+ * efi_var_mem_notify_exit_boot_services() - SetVirtualMemoryMap callback
+ *
+ * @event:	callback event
+ * @context:	callback context
+ */
+static void EFIAPI __efi_runtime
+efi_var_mem_notify_virtual_address_map(struct efi_event *event, void *context)
+{
+	efi_convert_pointer(0, (void **)&efi_var_buf);
+}
+
+efi_status_t efi_var_mem_init(void)
+{
+	u64 memory;
+	efi_status_t ret;
+	struct efi_event *event;
+
+	ret = efi_allocate_pages(EFI_ALLOCATE_ANY_PAGES,
+				 EFI_RUNTIME_SERVICES_DATA,
+				 efi_size_in_pages(EFI_VAR_BUF_SIZE),
+				 &memory);
+	if (ret != EFI_SUCCESS)
+		return ret;
+	efi_var_buf = (struct efi_var_file *)(uintptr_t)memory;
+	memset(efi_var_buf, 0, EFI_VAR_BUF_SIZE);
+	efi_var_buf->magic = EFI_VAR_FILE_MAGIC;
+	efi_var_buf->length = (uintptr_t)efi_var_buf->var -
+			      (uintptr_t)efi_var_buf;
+	/* crc32 for 0 bytes = 0 */
+
+	ret = efi_create_event(EVT_SIGNAL_EXIT_BOOT_SERVICES, TPL_CALLBACK,
+			       efi_var_mem_notify_exit_boot_services, NULL,
+			       NULL, &event);
+	if (ret != EFI_SUCCESS)
+		return ret;
+	ret = efi_create_event(EVT_SIGNAL_VIRTUAL_ADDRESS_CHANGE, TPL_CALLBACK,
+			       efi_var_mem_notify_virtual_address_map, NULL,
+			       NULL, &event);
+	if (ret != EFI_SUCCESS)
+		return ret;
+	return ret;
+}