Add sysfs files for the EFI System Resource Table (ESRT) under /sys/firmware/efi/esrt and for each EFI System Resource Entry under entries/ as a subdir. The EFI System Resource Table (ESRT) provides a read-only catalog of system components for which the system accepts firmware upgrades via UEFI's "Capsule Update" feature. This module allows userland utilities to evaluate what firmware updates can be applied to this system, and potentially arrange for those updates to occur. The ESRT is described as part of the UEFI specification, in version 2.5 which should be available from http://uefi.org/specifications in early 2015. If you're a member of the UEFI Forum, information about its addition to the standard is available as UEFI Mantis 1090. For some hardware platforms, additional restrictions may be found at http://msdn.microsoft.com/en-us/library/windows/hardware/jj128256.aspx , and additional documentation may be found at http://download.microsoft.com/download/5/F/5/5F5D16CD-2530-4289-8019-94C6A20BED3C/windows-uefi-firmware-update-platform.docx . Signed-off-by: Peter Jones <pjones@xxxxxxxxxx> --- drivers/firmware/efi/Makefile | 2 +- drivers/firmware/efi/efi.c | 63 ++++++- drivers/firmware/efi/esrt.c | 402 ++++++++++++++++++++++++++++++++++++++++++ include/linux/efi.h | 7 + 4 files changed, 472 insertions(+), 2 deletions(-) create mode 100644 drivers/firmware/efi/esrt.c diff --git a/drivers/firmware/efi/Makefile b/drivers/firmware/efi/Makefile index d8be608..26eabbc 100644 --- a/drivers/firmware/efi/Makefile +++ b/drivers/firmware/efi/Makefile @@ -1,7 +1,7 @@ # # Makefile for linux kernel # -obj-$(CONFIG_EFI) += efi.o vars.o reboot.o +obj-$(CONFIG_EFI) += efi.o esrt.o vars.o reboot.o obj-$(CONFIG_EFI_VARS) += efivars.o obj-$(CONFIG_EFI_VARS_PSTORE) += efi-pstore.o obj-$(CONFIG_UEFI_CPER) += cper.o diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index 9035c1b..9dc8cf7 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -39,6 +39,7 @@ struct efi __read_mostly efi = { .fw_vendor = EFI_INVALID_TABLE_ADDR, .runtime = EFI_INVALID_TABLE_ADDR, .config_table = EFI_INVALID_TABLE_ADDR, + .esrt = EFI_INVALID_TABLE_ADDR, }; EXPORT_SYMBOL(efi); @@ -64,7 +65,7 @@ static int __init parse_efi_cmdline(char *str) } early_param("efi", parse_efi_cmdline); -static struct kobject *efi_kobj; +struct kobject *efi_kobj; static struct kobject *efivars_kobj; /* @@ -95,6 +96,8 @@ static ssize_t systab_show(struct kobject *kobj, str += sprintf(str, "BOOTINFO=0x%lx\n", efi.boot_info); if (efi.uga != EFI_INVALID_TABLE_ADDR) str += sprintf(str, "UGA=0x%lx\n", efi.uga); + if (efi.esrt != EFI_INVALID_TABLE_ADDR) + str += sprintf(str, "ESRT=0x%lx\n", efi.esrt); return str - buf; } @@ -223,6 +226,63 @@ err_put: subsys_initcall(efisubsys_init); +/* + * Find the efi memory descriptor for a given physical address. Given a + * physicall address, determine if it exists within an EFI Memory Map entry, + * and if so, populate the supplied memory descriptor with the appropriate + * data. + */ +int efi_mem_desc_lookup(u64 phys_addr, efi_memory_desc_t *out_md) +{ + struct efi_memory_map *map = efi.memmap; + void *p, *e; + + if (!efi_enabled(EFI_MEMMAP)) + return -EINVAL; + + if (!map) + return -EINVAL; + if (!out_md) + return -EINVAL; + if (WARN_ON(!map->phys_map)) + return -EINVAL; + if (WARN_ON(map->nr_map == 0) || WARN_ON(map->desc_size == 0)) + return -EINVAL; + + e = map->phys_map + map->nr_map * map->desc_size; + for (p = map->phys_map; p < e; p += map->desc_size) { + /* + * If a driver calls this after efi_free_boot_services, + * ->map will be NULL. + * So just always get our own virtual map on the CPU. + */ + efi_memory_desc_t *md = phys_to_virt((phys_addr_t)p); + u64 size = md->num_pages << EFI_PAGE_SHIFT; + u64 end = md->phys_addr + size; + + if (!(md->attribute & EFI_MEMORY_RUNTIME) && + md->type != EFI_BOOT_SERVICES_CODE && + md->type != EFI_BOOT_SERVICES_DATA) + continue; + if (!md->virt_addr) + continue; + if (phys_addr >= md->phys_addr && phys_addr < end) { + memcpy(out_md, md, sizeof(*out_md)); + return 0; + } + } + return -ENOENT; +} + +/* + * Calculate the highest address of an efi memory descriptor. + */ +u64 efi_mem_desc_end(efi_memory_desc_t *md) +{ + u64 size = md->num_pages << EFI_PAGE_SHIFT; + u64 end = md->phys_addr + size; + return end; +} /* * We can't ioremap data in EFI boot services RAM, because we've already mapped @@ -265,6 +325,7 @@ static __initdata efi_config_table_type_t common_tables[] = { {SMBIOS_TABLE_GUID, "SMBIOS", &efi.smbios}, {SMBIOS3_TABLE_GUID, "SMBIOS 3.0", &efi.smbios3}, {UGA_IO_PROTOCOL_GUID, "UGA", &efi.uga}, + {EFI_SYSTEM_RESOURCE_TABLE_GUID, "ESRT", &efi.esrt}, {NULL_GUID, NULL, NULL}, }; diff --git a/drivers/firmware/efi/esrt.c b/drivers/firmware/efi/esrt.c new file mode 100644 index 0000000..c4c9534 --- /dev/null +++ b/drivers/firmware/efi/esrt.c @@ -0,0 +1,402 @@ +/* + * esrt.c + * + * This module exports EFI System Resource Table (ESRT) entries into userspace + * through the sysfs file system. The ESRT provides a read-only catalog of + * system components for which the system accepts firmware upgrades via UEFI's + * "Capsule Update" feature. This module allows userland utilities to evaluate + * what firmware updates can be applied to this system, and potentially arrange + * for those updates to occur. + * + * Data is currently found below /sys/firmware/efi/esrt/... + */ +#define pr_fmt(fmt) "esrt: " fmt + +#include <linux/capability.h> +#include <linux/device.h> +#include <linux/efi.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/kobject.h> +#include <linux/list.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/types.h> + +struct efi_system_resource_entry { + efi_guid_t fw_class; + u32 fw_type; + u32 fw_version; + u32 lowest_supported_fw_version; + u32 capsule_flags; + u32 last_attempt_version; + u32 last_attempt_status; +}; + +/* + * _count and _version are what they seem like. _max is actually just + * accounting info for the firmware when creating the table; it should never + * have been exposed to us. To wit, the spec says: + * The maximum number of resource array entries that can be within the + * table without reallocating the table, must not be zero. + * Since there's no guidance about what that means in terms of memory layout, + * it means nothing to us. + */ +struct efi_system_resource_table { + u32 fw_resource_count; + u32 fw_resource_count_max; + u64 fw_resource_version; + struct efi_system_resource_entry entries[]; +}; + +static struct efi_system_resource_table *esrt; + +struct esre_entry { + struct efi_system_resource_entry *esre; + + struct kobject kobj; + struct list_head list; +}; + +/* global list of esre_entry. */ +static LIST_HEAD(entry_list); + +/* entry attribute */ +struct esre_attribute { + struct attribute attr; + ssize_t (*show)(struct esre_entry *entry, char *buf); + ssize_t (*store)(struct esre_entry *entry, + const char *buf, size_t count); +}; + +static struct esre_entry *to_entry(struct kobject *kobj) +{ + return container_of(kobj, struct esre_entry, kobj); +} + +static struct esre_attribute *to_attr(struct attribute *attr) +{ + return container_of(attr, struct esre_attribute, attr); +} + +static ssize_t esre_attr_show(struct kobject *kobj, + struct attribute *_attr, char *buf) +{ + struct esre_entry *entry = to_entry(kobj); + struct esre_attribute *attr = to_attr(_attr); + + /* Don't tell normal users what firmware versions we've got... */ + if (!capable(CAP_SYS_ADMIN)) + return -EACCES; + + return attr->show(entry, buf); +} + +static const struct sysfs_ops esre_attr_ops = { + .show = esre_attr_show, +}; + +/* Generic ESRT Entry ("ESRE") support. */ +static ssize_t esre_fw_class_show(struct esre_entry *entry, char *buf) +{ + char *str = buf; + + efi_guid_unparse(&entry->esre->fw_class, str); + str += strlen(str); + str += sprintf(str, "\n"); + + return str - buf; +} + +static struct esre_attribute esre_fw_class = __ATTR(fw_class, 0400, + esre_fw_class_show, NULL); + +#define esre_attr_decl(name, size, fmt) \ +static ssize_t esre_##name##_show(struct esre_entry *entry, char *buf)\ +{ \ + return sprintf(buf, fmt "\n", le##size##_to_cpu(entry->esre->name)); \ +} \ +\ +static struct esre_attribute esre_##name = __ATTR(name, 0400, \ + esre_##name##_show, NULL) + +esre_attr_decl(fw_type, 32, "%u"); +esre_attr_decl(fw_version, 32, "%u"); +esre_attr_decl(lowest_supported_fw_version, 32, "%u"); +esre_attr_decl(capsule_flags, 32, "0x%x"); +esre_attr_decl(last_attempt_version, 32, "%u"); +esre_attr_decl(last_attempt_status, 32, "%u"); + +static struct attribute *esre_attrs[] = { + &esre_fw_class.attr, + &esre_fw_type.attr, + &esre_fw_version.attr, + &esre_lowest_supported_fw_version.attr, + &esre_capsule_flags.attr, + &esre_last_attempt_version.attr, + &esre_last_attempt_status.attr, + NULL +}; + +static void esre_release(struct kobject *kobj) +{ + struct esre_entry *entry = to_entry(kobj); + + list_del(&entry->list); + kfree(entry); +} + +static struct kobj_type esre_ktype = { + .release = esre_release, + .sysfs_ops = &esre_attr_ops, + .default_attrs = esre_attrs, +}; + +static struct kobject *esrt_kobj; +static struct kset *esrt_kset; + +static int esre_create_sysfs_entry(struct efi_system_resource_entry *esre) +{ + int rc; + struct esre_entry *entry; + char name[EFI_VARIABLE_GUID_LEN + 1]; + + entry = kzalloc(sizeof(*entry), GFP_KERNEL); + if (!entry) + return -ENOMEM; + + efi_guid_unparse(&esre->fw_class, name); + + entry->esre = esre; + entry->kobj.kset = esrt_kset; + rc = kobject_init_and_add(&entry->kobj, &esre_ktype, NULL, + "%s", name); + if (rc) { + kfree(entry); + return rc; + } + + list_add_tail(&entry->list, &entry_list); + return 0; +} + +/* support for displaying ESRT fields at the top level */ +#define esrt_attr_decl(name, size, fmt) \ +static ssize_t esrt_##name##_show(struct kobject *kobj, \ + struct kobj_attribute *attr, char *buf)\ +{ \ + return sprintf(buf, fmt "\n", le##size##_to_cpu(esrt->name)); \ +} \ +\ +static struct kobj_attribute esrt_##name = __ATTR(name, 0400, \ + esrt_##name##_show, NULL) + +esrt_attr_decl(fw_resource_count, 32, "%u"); +esrt_attr_decl(fw_resource_count_max, 32, "%u"); +esrt_attr_decl(fw_resource_version, 64, "%llu"); + +static struct attribute *esrt_attrs[] = { + &esrt_fw_resource_count.attr, + &esrt_fw_resource_count_max.attr, + &esrt_fw_resource_version.attr, + NULL, +}; + +static inline int esrt_table_exists(void) +{ + if (!efi_enabled(EFI_CONFIG_TABLES)) + return 0; + if (efi.esrt == EFI_INVALID_TABLE_ADDR) + return 0; + return 1; +} + +static umode_t esrt_attr_is_visible(struct kobject *kobj, + struct attribute *attr, int n) +{ + if (!esrt_table_exists()) + return 0; + return attr->mode; +} + +static struct attribute_group esrt_attr_group = { + .attrs = esrt_attrs, + .is_visible = esrt_attr_is_visible, +}; + +/* + * ioremap the table, copy it to kmalloced pages, and unmap it. + */ +static int esrt_duplicate_pages(void) +{ + struct efi_system_resource_table *tmpesrt; + struct efi_system_resource_entry *entries; + size_t size, max; + efi_memory_desc_t md; + int err = -EINVAL; + int rc; + + if (!esrt_table_exists()) + return err; + + rc = efi_mem_desc_lookup(efi.esrt, &md); + if (rc < 0) { + pr_err("ESRT header is not in the memory map.\n"); + return err; + } + + max = efi_mem_desc_end(&md); + if (max < 0) { + pr_err("EFI memory descriptor is invalid.\n"); + return err; + } + + size = sizeof(*esrt); + + if (max < size) { + pr_err("ESRT header doen't fit on single memory map entry.\n"); + return err; + } + + tmpesrt = ioremap(efi.esrt, size); + if (!tmpesrt) { + pr_err("ioremap failed.\n"); + return -ENOMEM; + } + + if (tmpesrt->fw_resource_count > 0 && max - size < sizeof(*entries)) { + pr_err("ESRT memory map entry can only hold the header.\n"); + goto err_iounmap; + } + + /* + * The format doesn't really give us any boundary to test here, + * so I'm making up 128 as the max number of individually updatable + * components we support. + * 128 should be pretty excessive, but there's still some chance + * somebody will do that someday and we'll need to raise this. + */ + if (tmpesrt->fw_resource_count > 128) { + pr_err("ESRT says fw_resource_count has very large value %d.\n", + tmpesrt->fw_resource_count); + goto err_iounmap; + } + + /* + * We know it can't be larger than N * sizeof() here, and N is limited + * by the previous test to a small number, so there's no overflow. + */ + size += tmpesrt->fw_resource_count * sizeof(*entries); + if (max < size) { + pr_err("ESRT does not fit on single memory map entry.\n"); + goto err_iounmap; + } + + esrt = kmalloc(size, GFP_KERNEL); + if (!esrt) { + err = -ENOMEM; + goto err_iounmap; + } + + memcpy(esrt, tmpesrt, size); + err = 0; +err_iounmap: + iounmap(tmpesrt); + return err; +} + +static int register_entries(void) +{ + struct efi_system_resource_entry *entries = esrt->entries; + int i, rc; + + if (!esrt_table_exists()) + return 0; + + for (i = 0; i < le32_to_cpu(esrt->fw_resource_count); i++) { + rc = esre_create_sysfs_entry(&entries[i]); + if (rc < 0) { + pr_err("ESRT entry creation failed with error %d.\n", + rc); + return rc; + } + } + return 0; +} + +static void cleanup_entry_list(void) +{ + struct esre_entry *entry, *next; + + list_for_each_entry_safe(entry, next, &entry_list, list) { + kobject_put(&entry->kobj); + } +} + +static int __init esrt_sysfs_init(void) +{ + int error; + + error = esrt_duplicate_pages(); + if (error) + return error; + + esrt_kobj = kobject_create_and_add("esrt", efi_kobj); + if (!esrt_kobj) { + pr_err("Firmware table registration failed.\n"); + error = -ENOMEM; + goto err; + } + + error = sysfs_create_group(esrt_kobj, &esrt_attr_group); + if (error) { + pr_err("Sysfs attribute export failed with error %d.\n", + error); + goto err_remove_esrt; + } + + esrt_kset = kset_create_and_add("entries", NULL, esrt_kobj); + if (!esrt_kset) { + pr_err("kset creation failed.\n"); + error = -ENOMEM; + goto err_remove_group; + } + + error = register_entries(); + if (error) + goto err_cleanup_list; + + pr_debug("esrt-sysfs: loaded.\n"); + + return 0; +err_cleanup_list: + cleanup_entry_list(); + kset_unregister(esrt_kset); +err_remove_group: + sysfs_remove_group(esrt_kobj, &esrt_attr_group); +err_remove_esrt: + kobject_put(esrt_kobj); +err: + kfree(esrt); + esrt = NULL; + return error; +} + +static void __exit esrt_sysfs_exit(void) +{ + pr_debug("esrt-sysfs: unloading.\n"); + cleanup_entry_list(); + kset_unregister(esrt_kset); + sysfs_remove_group(esrt_kobj, &esrt_attr_group); + kfree(esrt); + esrt = NULL; + kobject_del(esrt_kobj); + kobject_put(esrt_kobj); +} + +module_init(esrt_sysfs_init); +module_exit(esrt_sysfs_exit); + +MODULE_AUTHOR("Peter Jones <pjones@xxxxxxxxxx>"); +MODULE_DESCRIPTION("EFI System Resource Table support"); +MODULE_LICENSE("GPL"); diff --git a/include/linux/efi.h b/include/linux/efi.h index 0238d61..094d14c 100644 --- a/include/linux/efi.h +++ b/include/linux/efi.h @@ -565,6 +565,9 @@ void efi_native_runtime_setup(void); #define UV_SYSTEM_TABLE_GUID \ EFI_GUID( 0x3b13a7d4, 0x633e, 0x11dd, 0x93, 0xec, 0xda, 0x25, 0x56, 0xd8, 0x95, 0x93 ) +#define EFI_SYSTEM_RESOURCE_TABLE_GUID \ + EFI_GUID( 0xb122a263, 0x3661, 0x4f68, 0x99, 0x29, 0x78, 0xf8, 0xb0, 0xd6, 0x21, 0x80 ) + #define LINUX_EFI_CRASH_GUID \ EFI_GUID( 0xcfc8fc79, 0xbe2e, 0x4ddc, 0x97, 0xf0, 0x9f, 0x98, 0xbf, 0xe2, 0x98, 0xa0 ) @@ -823,6 +826,7 @@ extern struct efi { unsigned long fw_vendor; /* fw_vendor */ unsigned long runtime; /* runtime table */ unsigned long config_table; /* config tables */ + unsigned long esrt; /* EFI System Resource Table */ efi_get_time_t *get_time; efi_set_time_t *set_time; efi_get_wakeup_time_t *get_wakeup_time; @@ -880,12 +884,15 @@ extern u32 efi_mem_type (unsigned long phys_addr); extern u64 efi_mem_attributes (unsigned long phys_addr); extern u64 efi_mem_attribute (unsigned long phys_addr, unsigned long size); extern int __init efi_uart_console_only (void); +extern u64 efi_mem_desc_end(efi_memory_desc_t *md); +extern int efi_mem_desc_lookup(u64 phys_addr, efi_memory_desc_t *out_md); extern void efi_initialize_iomem_resources(struct resource *code_resource, struct resource *data_resource, struct resource *bss_resource); extern void efi_get_time(struct timespec *now); extern void efi_reserve_boot_services(void); extern int efi_get_fdt_params(struct efi_fdt_params *params, int verbose); extern struct efi_memory_map memmap; +extern struct kobject *efi_kobj; extern int efi_reboot_quirk_mode; extern bool efi_poweroff_required(void); -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
