[PATCH] lib/efi_loader: dynamically determine var store size
Paulo Alcantara
pc at cjr.nz
Wed Dec 9 19:03:47 CET 2020
In order to support (ESP)/ubootefi.var and preseed variables greater
than EFI_VAR_BUF_SIZE (0x4000), dynamically determine the variable
list size that will fit both and the ones that are created at boot
time.
Signed-off-by: Paulo Alcantara (SUSE) <pc at cjr.nz>
---
include/efi_variable.h | 15 +++++++++++++--
lib/efi_loader/efi_var_file.c | 36 ++++++++++++++++++++++++++++-------
lib/efi_loader/efi_var_mem.c | 12 +++++++-----
lib/efi_loader/efi_variable.c | 35 +++++++++++++++++++++++++++++++---
4 files changed, 81 insertions(+), 17 deletions(-)
diff --git a/include/efi_variable.h b/include/efi_variable.h
index 4704a3c16e65..cd40dfe3359d 100644
--- a/include/efi_variable.h
+++ b/include/efi_variable.h
@@ -8,6 +8,8 @@
#include <linux/bitops.h>
+extern efi_uintn_t __efi_runtime_data efi_var_buf_size;
+
#define EFI_VARIABLE_READ_ONLY BIT(31)
enum efi_auth_var_type {
@@ -91,7 +93,7 @@ efi_status_t efi_query_variable_info_int(u32 attributes,
#define EFI_VAR_FILE_NAME "ubootefi.var"
-#define EFI_VAR_BUF_SIZE 0x4000
+#define EFI_VAR_DEFAULT_BUF_SIZE 0x4000
/*
* This constant identifies the file format for storing UEFI variables in
@@ -179,12 +181,21 @@ efi_status_t efi_var_restore(struct efi_var_file *buf);
*/
efi_status_t efi_var_from_file(void);
+/**
+ * efi_var_file_size() - determine variable file size
+ *
+ * @fsize: variable file size
+ * Return: status code
+ */
+efi_status_t __maybe_unused efi_var_file_size(efi_uintn_t *fsize);
+
/**
* efi_var_mem_init() - set-up variable list
*
+ * @mem_size: variable list size
* Return: status code
*/
-efi_status_t efi_var_mem_init(void);
+efi_status_t efi_var_mem_init(efi_uintn_t mem_size);
/**
* efi_var_mem_find() - find a variable in the list
diff --git a/lib/efi_loader/efi_var_file.c b/lib/efi_loader/efi_var_file.c
index b171d2d1a8f7..42c674241ef4 100644
--- a/lib/efi_loader/efi_var_file.c
+++ b/lib/efi_loader/efi_var_file.c
@@ -49,7 +49,7 @@ static efi_status_t __maybe_unused efi_set_blk_dev_to_system_partition(void)
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;
+ 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;
@@ -193,12 +193,17 @@ efi_status_t efi_var_restore(struct efi_var_file *buf)
efi_status_t efi_var_from_file(void)
{
#ifdef CONFIG_EFI_VARIABLE_FILE_STORE
- struct efi_var_file *buf;
+ struct efi_var_file *buf = NULL;
+ efi_uintn_t fsize;
loff_t len;
efi_status_t ret;
int r;
- buf = calloc(1, EFI_VAR_BUF_SIZE);
+ ret = efi_var_file_size(&fsize);
+ if (ret != EFI_SUCCESS)
+ goto error;
+
+ buf = calloc(1, fsize);
if (!buf) {
log_err("Out of memory\n");
return EFI_OUT_OF_RESOURCES;
@@ -206,10 +211,10 @@ efi_status_t efi_var_from_file(void)
ret = efi_set_blk_dev_to_system_partition();
if (ret != EFI_SUCCESS)
- goto error;
- r = fs_read(EFI_VAR_FILE_NAME, map_to_sysmem(buf), 0, EFI_VAR_BUF_SIZE,
- &len);
- if (r || len < sizeof(struct efi_var_file)) {
+ return ret;
+
+ r = fs_read(EFI_VAR_FILE_NAME, map_to_sysmem(buf), 0, fsize, &len);
+ if (r || len != fsize) {
log_err("Failed to load EFI variables\n");
goto error;
}
@@ -220,3 +225,20 @@ error:
#endif
return EFI_SUCCESS;
}
+
+efi_status_t __maybe_unused efi_var_file_size(efi_uintn_t *fsize)
+{
+ efi_status_t ret;
+ loff_t size;
+ int r;
+
+ ret = efi_set_blk_dev_to_system_partition();
+ if (ret != EFI_SUCCESS)
+ return ret;
+
+ r = fs_size(EFI_VAR_FILE_NAME, &size);
+ if (r)
+ size = 0;
+ *fsize = size;
+ return EFI_SUCCESS;
+}
diff --git a/lib/efi_loader/efi_var_mem.c b/lib/efi_loader/efi_var_mem.c
index d155f25f60e6..323c3b71ace0 100644
--- a/lib/efi_loader/efi_var_mem.c
+++ b/lib/efi_loader/efi_var_mem.c
@@ -11,6 +11,7 @@
#include <u-boot/crc.h>
struct efi_var_file __efi_runtime_data *efi_var_buf;
+efi_uintn_t __efi_runtime_data efi_var_buf_size;
static struct efi_var_entry __efi_runtime_data *efi_current_var;
/**
@@ -146,7 +147,7 @@ efi_status_t __efi_runtime efi_var_mem_ins(
data = var->name + var_name_len;
if ((uintptr_t)data - (uintptr_t)efi_var_buf + size1 + size2 >
- EFI_VAR_BUF_SIZE)
+ efi_var_buf_size)
return EFI_OUT_OF_RESOURCES;
var->attr = attributes;
@@ -171,7 +172,7 @@ efi_status_t __efi_runtime efi_var_mem_ins(
u64 __efi_runtime efi_var_mem_free(void)
{
- return EFI_VAR_BUF_SIZE - efi_var_buf->length -
+ return efi_var_buf_size - efi_var_buf->length -
sizeof(struct efi_var_entry);
}
@@ -235,7 +236,7 @@ efi_var_mem_notify_virtual_address_map(struct efi_event *event, void *context)
efi_current_var = NULL;
}
-efi_status_t efi_var_mem_init(void)
+efi_status_t efi_var_mem_init(efi_uintn_t mem_size)
{
u64 memory;
efi_status_t ret;
@@ -243,12 +244,13 @@ efi_status_t efi_var_mem_init(void)
ret = efi_allocate_pages(EFI_ALLOCATE_ANY_PAGES,
EFI_RUNTIME_SERVICES_DATA,
- efi_size_in_pages(EFI_VAR_BUF_SIZE),
+ efi_size_in_pages(mem_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_size = mem_size;
+ 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;
diff --git a/lib/efi_loader/efi_variable.c b/lib/efi_loader/efi_variable.c
index 0c689cfb4705..af84c01c1f27 100644
--- a/lib/efi_loader/efi_variable.c
+++ b/lib/efi_loader/efi_variable.c
@@ -431,10 +431,10 @@ efi_status_t efi_query_variable_info_int(u32 attributes,
u64 *remaining_variable_storage_size,
u64 *maximum_variable_size)
{
- *maximum_variable_storage_size = EFI_VAR_BUF_SIZE -
+ *maximum_variable_storage_size = efi_var_buf_size -
sizeof(struct efi_var_file);
*remaining_variable_storage_size = efi_var_mem_free();
- *maximum_variable_size = EFI_VAR_BUF_SIZE -
+ *maximum_variable_size = efi_var_buf_size -
sizeof(struct efi_var_file) -
sizeof(struct efi_var_entry);
return EFI_SUCCESS;
@@ -496,6 +496,30 @@ void efi_variables_boot_exit_notify(void)
efi_update_table_header_crc32(&efi_runtime_services.hdr);
}
+/**
+ * efi_var_mem_size() - determine variable storage size
+ *
+ * Return: status code
+ */
+static efi_status_t efi_var_mem_size(efi_uintn_t *size)
+{
+ efi_status_t ret;
+ efi_uintn_t nsize = EFI_VAR_DEFAULT_BUF_SIZE;
+
+ if (IS_ENABLED(CONFIG_EFI_VARIABLES_PRESEED))
+ nsize += (uintptr_t)__efi_var_file_end - (uintptr_t)__efi_var_file_begin;
+ if (IS_ENABLED(CONFIG_EFI_VARIABLE_FILE_STORE)) {
+ efi_uintn_t fsize;
+
+ ret = efi_var_file_size(&fsize);
+ if (ret != EFI_SUCCESS)
+ return ret;
+ nsize += fsize;
+ }
+ *size = nsize;
+ return EFI_SUCCESS;
+}
+
/**
* efi_init_variables() - initialize variable services
*
@@ -504,8 +528,13 @@ void efi_variables_boot_exit_notify(void)
efi_status_t efi_init_variables(void)
{
efi_status_t ret;
+ efi_uintn_t mem_size;
- ret = efi_var_mem_init();
+ ret = efi_var_mem_size(&mem_size);
+ if (ret != EFI_SUCCESS)
+ return ret;
+
+ ret = efi_var_mem_init(mem_size);
if (ret != EFI_SUCCESS)
return ret;
--
2.29.2
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