diff options
| -rw-r--r-- | arch/x86/platform/efi/efi.c | 2 | ||||
| -rw-r--r-- | arch/x86/platform/efi/quirks.c | 4 | ||||
| -rw-r--r-- | drivers/firmware/efi/Kconfig | 5 | ||||
| -rw-r--r-- | drivers/firmware/efi/Makefile | 1 | ||||
| -rw-r--r-- | drivers/firmware/efi/efi.c | 57 | ||||
| -rw-r--r-- | drivers/firmware/efi/embedded-firmware.c | 147 | ||||
| -rw-r--r-- | include/linux/efi.h | 7 | ||||
| -rw-r--r-- | include/linux/efi_embedded_fw.h | 41 |
8 files changed, 264 insertions, 0 deletions
diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c index aca9bdd87bca..1aae5302501d 100644 --- a/arch/x86/platform/efi/efi.c +++ b/arch/x86/platform/efi/efi.c @@ -246,6 +246,7 @@ int __init efi_memblock_x86_reserve_range(void) efi.memmap.desc_version); memblock_reserve(pmap, efi.memmap.nr_map * efi.memmap.desc_size); + set_bit(EFI_PRESERVE_BS_REGIONS, &efi.flags); return 0; } @@ -901,6 +902,7 @@ static void __init __efi_enter_virtual_mode(void) goto err; } + efi_check_for_embedded_firmwares(); efi_free_boot_services(); if (!efi_is_mixed()) diff --git a/arch/x86/platform/efi/quirks.c b/arch/x86/platform/efi/quirks.c index b0e0161e2e8e..ce82f497ac67 100644 --- a/arch/x86/platform/efi/quirks.c +++ b/arch/x86/platform/efi/quirks.c @@ -410,6 +410,10 @@ void __init efi_free_boot_services(void) int num_entries = 0; void *new, *new_md; + /* Keep all regions for /sys/kernel/debug/efi */ + if (efi_enabled(EFI_DBG)) + return; + for_each_efi_memory_desc(md) { unsigned long long start = md->phys_addr; unsigned long long size = md->num_pages << EFI_PAGE_SHIFT; diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig index ecc83e2f032c..613828d3f106 100644 --- a/drivers/firmware/efi/Kconfig +++ b/drivers/firmware/efi/Kconfig @@ -239,6 +239,11 @@ config EFI_DISABLE_PCI_DMA endmenu +config EFI_EMBEDDED_FIRMWARE + bool + depends on EFI + select CRYPTO_LIB_SHA256 + config UEFI_CPER bool diff --git a/drivers/firmware/efi/Makefile b/drivers/firmware/efi/Makefile index 3c5a9690de04..317a05cd388b 100644 --- a/drivers/firmware/efi/Makefile +++ b/drivers/firmware/efi/Makefile @@ -27,6 +27,7 @@ obj-$(CONFIG_EFI_TEST) += test/ obj-$(CONFIG_EFI_DEV_PATH_PARSER) += dev-path-parser.o obj-$(CONFIG_APPLE_PROPERTIES) += apple-properties.o obj-$(CONFIG_EFI_RCI2_TABLE) += rci2-table.o +obj-$(CONFIG_EFI_EMBEDDED_FIRMWARE) += embedded-firmware.o fake_map-y += fake_mem.o fake_map-$(CONFIG_X86) += x86_fake_mem.o diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index d1746a579c99..1d5e9a030cb1 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -17,6 +17,7 @@ #include <linux/kobject.h> #include <linux/module.h> #include <linux/init.h> +#include <linux/debugfs.h> #include <linux/device.h> #include <linux/efi.h> #include <linux/of.h> @@ -291,6 +292,59 @@ free_entry: static inline int efivar_ssdt_load(void) { return 0; } #endif +#ifdef CONFIG_DEBUG_FS + +#define EFI_DEBUGFS_MAX_BLOBS 32 + +static struct debugfs_blob_wrapper debugfs_blob[EFI_DEBUGFS_MAX_BLOBS]; + +static void __init efi_debugfs_init(void) +{ + struct dentry *efi_debugfs; + efi_memory_desc_t *md; + char name[32]; + int type_count[EFI_BOOT_SERVICES_DATA + 1] = {}; + int i = 0; + + efi_debugfs = debugfs_create_dir("efi", NULL); + if (IS_ERR_OR_NULL(efi_debugfs)) + return; + + for_each_efi_memory_desc(md) { + switch (md->type) { + case EFI_BOOT_SERVICES_CODE: + snprintf(name, sizeof(name), "boot_services_code%d", + type_count[md->type]++); + break; + case EFI_BOOT_SERVICES_DATA: + snprintf(name, sizeof(name), "boot_services_data%d", + type_count[md->type]++); + break; + default: + continue; + } + + if (i >= EFI_DEBUGFS_MAX_BLOBS) { + pr_warn("More then %d EFI boot service segments, only showing first %d in debugfs\n", + EFI_DEBUGFS_MAX_BLOBS, EFI_DEBUGFS_MAX_BLOBS); + break; + } + + debugfs_blob[i].size = md->num_pages << EFI_PAGE_SHIFT; + debugfs_blob[i].data = memremap(md->phys_addr, + debugfs_blob[i].size, + MEMREMAP_WB); + if (!debugfs_blob[i].data) + continue; + + debugfs_create_blob(name, 0400, efi_debugfs, &debugfs_blob[i]); + i++; + } +} +#else +static inline void efi_debugfs_init(void) {} +#endif + /* * We register the efi subsystem with the firmware subsystem and the * efivars subsystem with the efi subsystem, if the system was booted with @@ -357,6 +411,9 @@ static int __init efisubsys_init(void) goto err_remove_group; } + if (efi_enabled(EFI_DBG) && efi_enabled(EFI_PRESERVE_BS_REGIONS)) + efi_debugfs_init(); + return 0; err_remove_group: diff --git a/drivers/firmware/efi/embedded-firmware.c b/drivers/firmware/efi/embedded-firmware.c new file mode 100644 index 000000000000..1bc9cdae2eed --- /dev/null +++ b/drivers/firmware/efi/embedded-firmware.c @@ -0,0 +1,147 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Support for extracting embedded firmware for peripherals from EFI code, + * + * Copyright (c) 2018 Hans de Goede <hdegoede@redhat.com> + */ + +#include <linux/dmi.h> +#include <linux/efi.h> +#include <linux/efi_embedded_fw.h> +#include <linux/io.h> +#include <linux/slab.h> +#include <linux/types.h> +#include <linux/vmalloc.h> +#include <crypto/sha.h> + +/* Exported for use by lib/test_firmware.c only */ +LIST_HEAD(efi_embedded_fw_list); +EXPORT_SYMBOL_GPL(efi_embedded_fw_list); + +static bool checked_for_fw; + +static const struct dmi_system_id * const embedded_fw_table[] = { + NULL +}; + +/* + * Note the efi_check_for_embedded_firmwares() code currently makes the + * following 2 assumptions. This may needs to be revisited if embedded firmware + * is found where this is not true: + * 1) The firmware is only found in EFI_BOOT_SERVICES_CODE memory segments + * 2) The firmware always starts at an offset which is a multiple of 8 bytes + */ +static int __init efi_check_md_for_embedded_firmware( + efi_memory_desc_t *md, const struct efi_embedded_fw_desc *desc) +{ + struct sha256_state sctx; + struct efi_embedded_fw *fw; + u8 sha256[32]; + u64 i, size; + u8 *map; + + size = md->num_pages << EFI_PAGE_SHIFT; + map = memremap(md->phys_addr, size, MEMREMAP_WB); + if (!map) { + pr_err("Error mapping EFI mem at %#llx\n", md->phys_addr); + return -ENOMEM; + } + + for (i = 0; (i + desc->length) <= size; i += 8) { + if (memcmp(map + i, desc->prefix, EFI_EMBEDDED_FW_PREFIX_LEN)) + continue; + + sha256_init(&sctx); + sha256_update(&sctx, map + i, desc->length); + sha256_final(&sctx, sha256); + if (memcmp(sha256, desc->sha256, 32) == 0) + break; + } + if ((i + desc->length) > size) { + memunmap(map); + return -ENOENT; + } + + pr_info("Found EFI embedded fw '%s'\n", desc->name); + + fw = kmalloc(sizeof(*fw), GFP_KERNEL); + if (!fw) { + memunmap(map); + return -ENOMEM; + } + + fw->data = kmemdup(map + i, desc->length, GFP_KERNEL); + memunmap(map); + if (!fw->data) { + kfree(fw); + return -ENOMEM; + } + + fw->name = desc->name; + fw->length = desc->length; + list_add(&fw->list, &efi_embedded_fw_list); + + return 0; +} + +void __init efi_check_for_embedded_firmwares(void) +{ + const struct efi_embedded_fw_desc *fw_desc; + const struct dmi_system_id *dmi_id; + efi_memory_desc_t *md; + int i, r; + + for (i = 0; embedded_fw_table[i]; i++) { + dmi_id = dmi_first_match(embedded_fw_table[i]); + if (!dmi_id) + continue; + + fw_desc = dmi_id->driver_data; + + /* + * In some drivers the struct driver_data contains may contain + * other driver specific data after the fw_desc struct; and + * the fw_desc struct itself may be empty, skip these. + */ + if (!fw_desc->name) + continue; + + for_each_efi_memory_desc(md) { + if (md->type != EFI_BOOT_SERVICES_CODE) + continue; + + r = efi_check_md_for_embedded_firmware(md, fw_desc); + if (r == 0) + break; + } + } + + checked_for_fw = true; +} + +int efi_get_embedded_fw(const char *name, const u8 **data, size_t *size) +{ + struct efi_embedded_fw *iter, *fw = NULL; + + if (!checked_for_fw) { + pr_warn("Warning %s called while we did not check for embedded fw\n", + __func__); + return -ENOENT; + } + + list_for_each_entry(iter, &efi_embedded_fw_list, list) { + if (strcmp(name, iter->name) == 0) { + fw = iter; + break; + } + } + + if (!fw) + return -ENOENT; + + *data = fw->data; + *size = fw->length; + + return 0; +} +EXPORT_SYMBOL_GPL(efi_get_embedded_fw); diff --git a/include/linux/efi.h b/include/linux/efi.h index e8a08a499131..abfc98e4dfe1 100644 --- a/include/linux/efi.h +++ b/include/linux/efi.h @@ -775,6 +775,7 @@ extern int __init efi_setup_pcdp_console(char *); #define EFI_NX_PE_DATA 9 /* Can runtime data regions be mapped non-executable? */ #define EFI_MEM_ATTR 10 /* Did firmware publish an EFI_MEMORY_ATTRIBUTES table? */ #define EFI_MEM_NO_SOFT_RESERVE 11 /* Is the kernel configured to ignore soft reservations? */ +#define EFI_PRESERVE_BS_REGIONS 12 /* Are EFI boot-services memory segments available? */ #ifdef CONFIG_EFI /* @@ -1097,6 +1098,12 @@ static inline void efi_enable_reset_attack_mitigation(void) { } #endif +#ifdef CONFIG_EFI_EMBEDDED_FIRMWARE +void efi_check_for_embedded_firmwares(void); +#else +static inline void efi_check_for_embedded_firmwares(void) { } +#endif + efi_status_t efi_random_get_seed(void); void efi_retrieve_tpm2_eventlog(void); diff --git a/include/linux/efi_embedded_fw.h b/include/linux/efi_embedded_fw.h new file mode 100644 index 000000000000..3d066c6370c6 --- /dev/null +++ b/include/linux/efi_embedded_fw.h @@ -0,0 +1,41 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _LINUX_EFI_EMBEDDED_FW_H +#define _LINUX_EFI_EMBEDDED_FW_H + +#include <linux/list.h> +#include <linux/mod_devicetable.h> + +#define EFI_EMBEDDED_FW_PREFIX_LEN 8 + +/* + * This struct and efi_embedded_fw_list are private to the efi-embedded fw + * implementation they are in this header for use by lib/test_firmware.c only! + */ +struct efi_embedded_fw { + struct list_head list; + const char *name; + const u8 *data; + size_t length; +}; + +extern struct list_head efi_embedded_fw_list; + +/** + * struct efi_embedded_fw_desc - This struct is used by the EFI embedded-fw + * code to search for embedded firmwares. + * + * @name: Name to register the firmware with if found + * @prefix: First 8 bytes of the firmware + * @length: Length of the firmware in bytes including prefix + * @sha256: SHA256 of the firmware + */ +struct efi_embedded_fw_desc { + const char *name; + u8 prefix[EFI_EMBEDDED_FW_PREFIX_LEN]; + u32 length; + u8 sha256[32]; +}; + +int efi_get_embedded_fw(const char *name, const u8 **dat, size_t *sz); + +#endif |