Merge tag 'efi-next' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi into efi/core

More EFI updates for v5.7

 - Incorporate a stable branch with the EFI pieces of Hans's work on
   loading device firmware from EFI boot service memory regions

Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Ingo Molnar 2020-03-08 08:59:47 +01:00
commit 3be5f0d286
8 changed files with 264 additions and 0 deletions

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@ -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())

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@ -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;

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@ -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

View File

@ -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

View File

@ -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 @@ static __init int efivar_ssdt_load(void)
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:

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@ -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);

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@ -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);

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@ -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