diff options
Diffstat (limited to 'lib/efi_loader/efi_var_mem.c')
| -rw-r--r-- | lib/efi_loader/efi_var_mem.c | 151 |
1 files changed, 98 insertions, 53 deletions
diff --git a/lib/efi_loader/efi_var_mem.c b/lib/efi_loader/efi_var_mem.c index 6c21cec5d45..940ab663882 100644 --- a/lib/efi_loader/efi_var_mem.c +++ b/lib/efi_loader/efi_var_mem.c @@ -61,6 +61,23 @@ efi_var_mem_compare(struct efi_var_entry *var, const efi_guid_t *guid, return match; } +/** + * efi_var_entry_len() - Get the entry len including headers & name + * + * @var: pointer to variable start + * + * Return: 8-byte aligned variable entry length + */ + +u32 __efi_runtime efi_var_entry_len(struct efi_var_entry *var) +{ + if (!var) + return 0; + + return ALIGN((sizeof(u16) * (u16_strlen(var->name) + 1)) + + var->length + sizeof(*var), 8); +} + struct efi_var_entry __efi_runtime *efi_var_mem_find(const efi_guid_t *guid, const u16 *name, struct efi_var_entry **next) @@ -185,53 +202,6 @@ u64 __efi_runtime efi_var_mem_free(void) } /** - * 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_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 @@ -261,11 +231,7 @@ efi_status_t efi_var_mem_init(void) 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, @@ -276,10 +242,71 @@ efi_status_t efi_var_mem_init(void) return ret; } +/** + * efi_var_collect_mem() - Copy EFI variables matching attributes mask from + * efi_var_buf + * + * @buf: buffer containing variable collection + * @lenp: buffer length + * @mask: mask of matched attributes + * + * Return: Status code + */ +efi_status_t __efi_runtime +efi_var_collect_mem(struct efi_var_file *buf, efi_uintn_t *lenp, u32 mask) +{ + static struct efi_var_file __efi_runtime_data hdr = { + .magic = EFI_VAR_FILE_MAGIC, + }; + struct efi_var_entry *last, *var, *var_to; + + hdr.length = sizeof(struct efi_var_file); + + var = efi_var_buf->var; + last = (struct efi_var_entry *) + ((uintptr_t)efi_var_buf + efi_var_buf->length); + if (buf) + var_to = buf->var; + + while (var < last) { + u32 len = efi_var_entry_len(var); + + if ((var->attr & mask) != mask) { + var = (void *)((uintptr_t)var + len); + continue; + } + + hdr.length += len; + + if (buf && hdr.length <= *lenp) { + efi_memcpy_runtime(var_to, var, len); + var_to = (void *)var_to + len; + } + var = (void *)var + len; + } + + if (!buf && hdr.length <= *lenp) { + *lenp = hdr.length; + return EFI_INVALID_PARAMETER; + } + + if (!buf || hdr.length > *lenp) { + *lenp = hdr.length; + return EFI_BUFFER_TOO_SMALL; + } + hdr.crc32 = crc32(0, (u8 *)buf->var, + hdr.length - sizeof(struct efi_var_file)); + + efi_memcpy_runtime(buf, &hdr, sizeof(hdr)); + *lenp = hdr.length; + + return EFI_SUCCESS; +} + efi_status_t __efi_runtime efi_get_variable_mem(const u16 *variable_name, const efi_guid_t *vendor, u32 *attributes, efi_uintn_t *data_size, void *data, - u64 *timep) + u64 *timep, u32 mask) { efi_uintn_t old_size; struct efi_var_entry *var; @@ -291,11 +318,22 @@ efi_get_variable_mem(const u16 *variable_name, const efi_guid_t *vendor, if (!var) return EFI_NOT_FOUND; + /* + * This function is used at runtime to dump EFI variables. + * The memory backend we keep around has BS-only variables as + * well. At runtime we filter them here + */ + if (mask && !((var->attr & mask) == mask)) + return EFI_NOT_FOUND; + if (attributes) *attributes = var->attr; if (timep) *timep = var->time; + if (!u16_strcmp(variable_name, u"VarToFile")) + return efi_var_collect_mem(data, data_size, EFI_VARIABLE_NON_VOLATILE); + old_size = *data_size; *data_size = var->length; if (old_size < var->length) @@ -315,7 +353,8 @@ efi_get_variable_mem(const u16 *variable_name, const efi_guid_t *vendor, efi_status_t __efi_runtime efi_get_next_variable_name_mem(efi_uintn_t *variable_name_size, - u16 *variable_name, efi_guid_t *vendor) + u16 *variable_name, efi_guid_t *vendor, + u32 mask) { struct efi_var_entry *var; efi_uintn_t len, old_size; @@ -324,6 +363,7 @@ efi_get_next_variable_name_mem(efi_uintn_t *variable_name_size, if (!variable_name_size || !variable_name || !vendor) return EFI_INVALID_PARAMETER; +skip: len = *variable_name_size >> 1; if (u16_strnlen(variable_name, len) == len) return EFI_INVALID_PARAMETER; @@ -347,6 +387,11 @@ efi_get_next_variable_name_mem(efi_uintn_t *variable_name_size, efi_memcpy_runtime(variable_name, var->name, *variable_name_size); efi_memcpy_runtime(vendor, &var->guid, sizeof(efi_guid_t)); + if (mask && !((var->attr & mask) == mask)) { + *variable_name_size = old_size; + goto skip; + } + return EFI_SUCCESS; } |