diff options
Diffstat (limited to 'arch/x86/platform/efi/efi.c')
-rw-r--r-- | arch/x86/platform/efi/efi.c | 193 |
1 files changed, 70 insertions, 123 deletions
diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c index 55856b2..d2fbced 100644 --- a/arch/x86/platform/efi/efi.c +++ b/arch/x86/platform/efi/efi.c @@ -42,7 +42,6 @@ #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> @@ -54,12 +53,12 @@ #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, @@ -79,13 +78,6 @@ 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; /* @@ -188,53 +180,8 @@ static efi_status_t virt_efi_get_next_variable(unsigned long *name_size, 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, @@ -243,34 +190,9 @@ 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, @@ -786,9 +708,6 @@ 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 || @@ -806,22 +725,6 @@ 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); /* @@ -1085,6 +988,13 @@ void __init efi_enter_virtual_mode(void) 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); } /* @@ -1136,33 +1046,70 @@ efi_status_t efi_query_variable_store(u32 attributes, unsigned long size) 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; } |