#include <linux/io.h>
#include <linux/reboot.h>
#include <linux/bcd.h>
-#include <linux/ucs2_string.h>
#include <asm/setup.h>
#include <asm/efi.h>
#define EFI_DEBUG 1
-/*
- * There's some additional metadata associated with each
- * variable. Intel's reference implementation is 60 bytes - bump that
- * to account for potential alignment constraints
- */
-#define VAR_METADATA_SIZE 64
+#define EFI_MIN_RESERVE 5120
+
+#define EFI_DUMMY_GUID \
+ EFI_GUID(0x4424ac57, 0xbe4b, 0x47dd, 0x9e, 0x97, 0xed, 0x50, 0xf0, 0x9f, 0x92, 0xa9)
+
+static efi_char16_t efi_dummy_name[6] = { 'D', 'U', 'M', 'M', 'Y', 0 };
struct efi __read_mostly efi = {
.mps = EFI_INVALID_TABLE_ADDR,
static struct efi efi_phys __initdata;
static efi_system_table_t efi_systab __initdata;
-static u64 efi_var_store_size;
-static u64 efi_var_remaining_size;
-static u64 efi_var_max_var_size;
-static u64 boot_used_size;
-static u64 boot_var_size;
-static u64 active_size;
-
unsigned long x86_efi_facility;
/*
efi_char16_t *name,
efi_guid_t *vendor)
{
- efi_status_t status;
- static bool finished = false;
- static u64 var_size;
-
- status = efi_call_virt3(get_next_variable,
- name_size, name, vendor);
-
- if (status == EFI_NOT_FOUND) {
- finished = true;
- if (var_size < boot_used_size) {
- boot_var_size = boot_used_size - var_size;
- active_size += boot_var_size;
- } else {
- printk(KERN_WARNING FW_BUG "efi: Inconsistent initial sizes\n");
- }
- }
-
- if (boot_used_size && !finished) {
- unsigned long size;
- u32 attr;
- efi_status_t s;
- void *tmp;
-
- s = virt_efi_get_variable(name, vendor, &attr, &size, NULL);
-
- if (s != EFI_BUFFER_TOO_SMALL || !size)
- return status;
-
- tmp = kmalloc(size, GFP_ATOMIC);
-
- if (!tmp)
- return status;
-
- s = virt_efi_get_variable(name, vendor, &attr, &size, tmp);
-
- if (s == EFI_SUCCESS && (attr & EFI_VARIABLE_NON_VOLATILE)) {
- var_size += size;
- var_size += ucs2_strsize(name, 1024);
- active_size += size;
- active_size += VAR_METADATA_SIZE;
- active_size += ucs2_strsize(name, 1024);
- }
-
- kfree(tmp);
- }
-
- return status;
+ return efi_call_virt3(get_next_variable,
+ name_size, name, vendor);
}
static efi_status_t virt_efi_set_variable(efi_char16_t *name,
unsigned long data_size,
void *data)
{
- efi_status_t status;
- u32 orig_attr = 0;
- unsigned long orig_size = 0;
-
- status = virt_efi_get_variable(name, vendor, &orig_attr, &orig_size,
- NULL);
-
- if (status != EFI_BUFFER_TOO_SMALL)
- orig_size = 0;
-
- status = efi_call_virt5(set_variable,
- name, vendor, attr,
- data_size, data);
-
- if (status == EFI_SUCCESS) {
- if (orig_size) {
- active_size -= orig_size;
- active_size -= ucs2_strsize(name, 1024);
- active_size -= VAR_METADATA_SIZE;
- }
- if (data_size) {
- active_size += data_size;
- active_size += ucs2_strsize(name, 1024);
- active_size += VAR_METADATA_SIZE;
- }
- }
-
- return status;
+ return efi_call_virt5(set_variable,
+ name, vendor, attr,
+ data_size, data);
}
static efi_status_t virt_efi_query_variable_info(u32 attr,
char vendor[100] = "unknown";
int i = 0;
void *tmp;
- struct setup_data *data;
- struct efi_var_bootdata *efi_var_data;
- u64 pa_data;
#ifdef CONFIG_X86_32
if (boot_params.efi_info.efi_systab_hi ||
if (efi_systab_init(efi_phys.systab))
return;
- pa_data = boot_params.hdr.setup_data;
- while (pa_data) {
- data = early_ioremap(pa_data, sizeof(*efi_var_data));
- if (data->type == SETUP_EFI_VARS) {
- efi_var_data = (struct efi_var_bootdata *)data;
-
- efi_var_store_size = efi_var_data->store_size;
- efi_var_remaining_size = efi_var_data->remaining_size;
- efi_var_max_var_size = efi_var_data->max_var_size;
- }
- pa_data = data->next;
- early_iounmap(data, sizeof(*efi_var_data));
- }
-
- boot_used_size = efi_var_store_size - efi_var_remaining_size;
-
set_bit(EFI_SYSTEM_TABLES, &x86_efi_facility);
/*
runtime_code_page_mkexec();
kfree(new_memmap);
+
+ /* clean DUMMY object */
+ efi.set_variable(efi_dummy_name, &EFI_DUMMY_GUID,
+ EFI_VARIABLE_NON_VOLATILE |
+ EFI_VARIABLE_BOOTSERVICE_ACCESS |
+ EFI_VARIABLE_RUNTIME_ACCESS,
+ 0, NULL);
}
/*
efi_status_t status;
u64 storage_size, remaining_size, max_size;
+ if (!(attributes & EFI_VARIABLE_NON_VOLATILE))
+ return 0;
+
status = efi.query_variable_info(attributes, &storage_size,
&remaining_size, &max_size);
if (status != EFI_SUCCESS)
return status;
- if (!max_size && remaining_size > size)
- printk_once(KERN_ERR FW_BUG "Broken EFI implementation"
- " is returning MaxVariableSize=0\n");
/*
* Some firmware implementations refuse to boot if there's insufficient
* space in the variable store. We account for that by refusing the
* write if permitting it would reduce the available space to under
- * 50%. However, some firmware won't reclaim variable space until
- * after the used (not merely the actively used) space drops below
- * a threshold. We can approximate that case with the value calculated
- * above. If both the firmware and our calculations indicate that the
- * available space would drop below 50%, refuse the write.
+ * 5KB. This figure was provided by Samsung, so should be safe.
*/
+ if ((remaining_size - size < EFI_MIN_RESERVE) &&
+ !efi_no_storage_paranoia) {
+
+ /*
+ * Triggering garbage collection may require that the firmware
+ * generate a real EFI_OUT_OF_RESOURCES error. We can force
+ * that by attempting to use more space than is available.
+ */
+ unsigned long dummy_size = remaining_size + 1024;
+ void *dummy = kzalloc(dummy_size, GFP_ATOMIC);
+
+ if (!dummy)
+ return EFI_OUT_OF_RESOURCES;
+
+ status = efi.set_variable(efi_dummy_name, &EFI_DUMMY_GUID,
+ EFI_VARIABLE_NON_VOLATILE |
+ EFI_VARIABLE_BOOTSERVICE_ACCESS |
+ EFI_VARIABLE_RUNTIME_ACCESS,
+ dummy_size, dummy);
+
+ if (status == EFI_SUCCESS) {
+ /*
+ * This should have failed, so if it didn't make sure
+ * that we delete it...
+ */
+ efi.set_variable(efi_dummy_name, &EFI_DUMMY_GUID,
+ EFI_VARIABLE_NON_VOLATILE |
+ EFI_VARIABLE_BOOTSERVICE_ACCESS |
+ EFI_VARIABLE_RUNTIME_ACCESS,
+ 0, dummy);
+ }
+
+ kfree(dummy);
- if (!storage_size || size > remaining_size ||
- (max_size && size > max_size))
- return EFI_OUT_OF_RESOURCES;
+ /*
+ * The runtime code may now have triggered a garbage collection
+ * run, so check the variable info again
+ */
+ status = efi.query_variable_info(attributes, &storage_size,
+ &remaining_size, &max_size);
- if (!efi_no_storage_paranoia &&
- ((active_size + size + VAR_METADATA_SIZE > storage_size / 2) &&
- (remaining_size - size < storage_size / 2)))
- return EFI_OUT_OF_RESOURCES;
+ if (status != EFI_SUCCESS)
+ return status;
+
+ /*
+ * There still isn't enough room, so return an error
+ */
+ if (remaining_size - size < EFI_MIN_RESERVE)
+ return EFI_OUT_OF_RESOURCES;
+ }
return EFI_SUCCESS;
}
projects / firefly-linux-kernel-4.4.55.git / blobdiff