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authorH. Peter Anvin <hpa@linux.intel.com>2013-04-19 17:09:03 -0700
committerH. Peter Anvin <hpa@linux.intel.com>2013-04-19 17:09:03 -0700
commitc0a9f451e4e7ecd2ad1a6c27ea5c31d0226bdddf (patch)
treedcb22c46c33a994db115ec8925093f91f6463f15 /arch
parent74c3e3fcf350b2e7e3eaf9550528ee3f74e44b37 (diff)
parent8c58bf3eec3b8fc8162fe557e9361891c20758f2 (diff)
downloadlinux-c0a9f451e4e7ecd2ad1a6c27ea5c31d0226bdddf.tar.gz
Merge remote-tracking branch 'efi/urgent' into x86/urgent
Matt Fleming (1): x86, efivars: firmware bug workarounds should be in platform code Matthew Garrett (3): Move utf16 functions to kernel core and rename efi: Pass boot services variable info to runtime code efi: Distinguish between "remaining space" and actually used space Richard Weinberger (2): x86,efi: Check max_size only if it is non-zero. x86,efi: Implement efi_no_storage_paranoia parameter Sergey Vlasov (2): x86/Kconfig: Make EFI select UCS2_STRING efi: Export efi_query_variable_store() for efivars.ko Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/Kconfig1
-rw-r--r--arch/x86/boot/compressed/eboot.c47
-rw-r--r--arch/x86/include/asm/efi.h7
-rw-r--r--arch/x86/include/uapi/asm/bootparam.h1
-rw-r--r--arch/x86/platform/efi/efi.c168
5 files changed, 219 insertions, 5 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 70c0f3da047..15b5cef4aa3 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1549,6 +1549,7 @@ config X86_SMAP
config EFI
bool "EFI runtime service support"
depends on ACPI
+ select UCS2_STRING
---help---
This enables the kernel to use EFI runtime services that are
available (such as the EFI variable services).
diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c
index c205035a6b9..8615f758182 100644
--- a/arch/x86/boot/compressed/eboot.c
+++ b/arch/x86/boot/compressed/eboot.c
@@ -251,6 +251,51 @@ static void find_bits(unsigned long mask, u8 *pos, u8 *size)
*size = len;
}
+static efi_status_t setup_efi_vars(struct boot_params *params)
+{
+ struct setup_data *data;
+ struct efi_var_bootdata *efidata;
+ u64 store_size, remaining_size, var_size;
+ efi_status_t status;
+
+ if (!sys_table->runtime->query_variable_info)
+ return EFI_UNSUPPORTED;
+
+ data = (struct setup_data *)(unsigned long)params->hdr.setup_data;
+
+ while (data && data->next)
+ data = (struct setup_data *)(unsigned long)data->next;
+
+ status = efi_call_phys4(sys_table->runtime->query_variable_info,
+ EFI_VARIABLE_NON_VOLATILE |
+ EFI_VARIABLE_BOOTSERVICE_ACCESS |
+ EFI_VARIABLE_RUNTIME_ACCESS, &store_size,
+ &remaining_size, &var_size);
+
+ if (status != EFI_SUCCESS)
+ return status;
+
+ status = efi_call_phys3(sys_table->boottime->allocate_pool,
+ EFI_LOADER_DATA, sizeof(*efidata), &efidata);
+
+ if (status != EFI_SUCCESS)
+ return status;
+
+ efidata->data.type = SETUP_EFI_VARS;
+ efidata->data.len = sizeof(struct efi_var_bootdata) -
+ sizeof(struct setup_data);
+ efidata->data.next = 0;
+ efidata->store_size = store_size;
+ efidata->remaining_size = remaining_size;
+ efidata->max_var_size = var_size;
+
+ if (data)
+ data->next = (unsigned long)efidata;
+ else
+ params->hdr.setup_data = (unsigned long)efidata;
+
+}
+
static efi_status_t setup_efi_pci(struct boot_params *params)
{
efi_pci_io_protocol *pci;
@@ -1157,6 +1202,8 @@ struct boot_params *efi_main(void *handle, efi_system_table_t *_table,
setup_graphics(boot_params);
+ setup_efi_vars(boot_params);
+
setup_efi_pci(boot_params);
status = efi_call_phys3(sys_table->boottime->allocate_pool,
diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h
index 60c89f30c72..2fb5d5884e2 100644
--- a/arch/x86/include/asm/efi.h
+++ b/arch/x86/include/asm/efi.h
@@ -102,6 +102,13 @@ extern void efi_call_phys_epilog(void);
extern void efi_unmap_memmap(void);
extern void efi_memory_uc(u64 addr, unsigned long size);
+struct efi_var_bootdata {
+ struct setup_data data;
+ u64 store_size;
+ u64 remaining_size;
+ u64 max_var_size;
+};
+
#ifdef CONFIG_EFI
static inline bool efi_is_native(void)
diff --git a/arch/x86/include/uapi/asm/bootparam.h b/arch/x86/include/uapi/asm/bootparam.h
index c15ddaf9071..08744242b8d 100644
--- a/arch/x86/include/uapi/asm/bootparam.h
+++ b/arch/x86/include/uapi/asm/bootparam.h
@@ -6,6 +6,7 @@
#define SETUP_E820_EXT 1
#define SETUP_DTB 2
#define SETUP_PCI 3
+#define SETUP_EFI_VARS 4
/* ram_size flags */
#define RAMDISK_IMAGE_START_MASK 0x07FF
diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index 5f2ecaf3f9d..e4a86a677ce 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -41,6 +41,7 @@
#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>
@@ -51,6 +52,13 @@
#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
+
struct efi __read_mostly efi = {
.mps = EFI_INVALID_TABLE_ADDR,
.acpi = EFI_INVALID_TABLE_ADDR,
@@ -69,6 +77,13 @@ struct efi_memory_map memmap;
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;
/*
@@ -98,6 +113,15 @@ static int __init setup_add_efi_memmap(char *arg)
}
early_param("add_efi_memmap", setup_add_efi_memmap);
+static bool efi_no_storage_paranoia;
+
+static int __init setup_storage_paranoia(char *arg)
+{
+ efi_no_storage_paranoia = true;
+ return 0;
+}
+early_param("efi_no_storage_paranoia", setup_storage_paranoia);
+
static efi_status_t virt_efi_get_time(efi_time_t *tm, efi_time_cap_t *tc)
{
@@ -162,8 +186,53 @@ static efi_status_t virt_efi_get_next_variable(unsigned long *name_size,
efi_char16_t *name,
efi_guid_t *vendor)
{
- return efi_call_virt3(get_next_variable,
- name_size, name, 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;
}
static efi_status_t virt_efi_set_variable(efi_char16_t *name,
@@ -172,9 +241,34 @@ static efi_status_t virt_efi_set_variable(efi_char16_t *name,
unsigned long data_size,
void *data)
{
- return efi_call_virt5(set_variable,
- name, vendor, attr,
- data_size, 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;
}
static efi_status_t virt_efi_query_variable_info(u32 attr,
@@ -682,6 +776,9 @@ void __init efi_init(void)
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 ||
@@ -699,6 +796,22 @@ void __init efi_init(void)
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);
/*
@@ -999,3 +1112,48 @@ u64 efi_mem_attributes(unsigned long phys_addr)
}
return 0;
}
+
+/*
+ * Some firmware has serious problems when using more than 50% of the EFI
+ * variable store, i.e. it triggers bugs that can brick machines. Ensure that
+ * we never use more than this safe limit.
+ *
+ * Return EFI_SUCCESS if it is safe to write 'size' bytes to the variable
+ * store.
+ */
+efi_status_t efi_query_variable_store(u32 attributes, unsigned long size)
+{
+ efi_status_t status;
+ u64 storage_size, remaining_size, max_size;
+
+ 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.
+ */
+
+ if (!storage_size || size > remaining_size ||
+ (max_size && size > max_size))
+ return EFI_OUT_OF_RESOURCES;
+
+ 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;
+
+ return EFI_SUCCESS;
+}
+EXPORT_SYMBOL_GPL(efi_query_variable_store);