diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2017-09-07 09:42:35 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-09-07 09:42:35 -0700 |
commit | f92e3da18b7d5941468040af962c201235148301 (patch) | |
tree | 45b05ba50dfe4c5de9cf99b889297a6b51449a8b /drivers/firmware | |
parent | 57e88b43b81301d9b28f124a5576ac43a1cf9e8d (diff) | |
parent | 6de47a5e371f75f80544986e6c9636211a2ae8af (diff) | |
download | op-kernel-dev-f92e3da18b7d5941468040af962c201235148301.zip op-kernel-dev-f92e3da18b7d5941468040af962c201235148301.tar.gz |
Merge branch 'efi-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull EFI updates from Ingo Molnar:
"The main changes in this cycle were:
- Transparently fall back to other poweroff method(s) if EFI poweroff
fails (and returns)
- Use separate PE/COFF section headers for the RX and RW parts of the
ARM stub loader so that the firmware can use strict mapping
permissions
- Add support for requesting the firmware to wipe RAM at warm reboot
- Increase the size of the random seed obtained from UEFI so CRNG
fast init can complete earlier
- Update the EFI framebuffer address if it points to a BAR that gets
moved by the PCI resource allocation code
- Enable "reset attack mitigation" of TPM environments: this is
enabled if the kernel is configured with
CONFIG_RESET_ATTACK_MITIGATION=y.
- Clang related fixes
- Misc cleanups, constification, refactoring, etc"
* 'efi-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
efi/bgrt: Use efi_mem_type()
efi: Move efi_mem_type() to common code
efi/reboot: Make function pointer orig_pm_power_off static
efi/random: Increase size of firmware supplied randomness
efi/libstub: Enable reset attack mitigation
firmware/efi/esrt: Constify attribute_group structures
firmware/efi: Constify attribute_group structures
firmware/dcdbas: Constify attribute_group structures
arm/efi: Split zImage code and data into separate PE/COFF sections
arm/efi: Replace open coded constants with symbolic ones
arm/efi: Remove pointless dummy .reloc section
arm/efi: Remove forbidden values from the PE/COFF header
drivers/fbdev/efifb: Allow BAR to be moved instead of claiming it
efi/reboot: Fall back to original power-off method if EFI_RESET_SHUTDOWN returns
efi/arm/arm64: Add missing assignment of efi.config_table
efi/libstub/arm64: Set -fpie when building the EFI stub
efi/libstub/arm64: Force 'hidden' visibility for section markers
efi/libstub/arm64: Use hidden attribute for struct screen_info reference
efi/arm: Don't mark ACPI reclaim memory as MEMBLOCK_NOMAP
Diffstat (limited to 'drivers/firmware')
-rw-r--r-- | drivers/firmware/dcdbas.c | 2 | ||||
-rw-r--r-- | drivers/firmware/efi/Kconfig | 10 | ||||
-rw-r--r-- | drivers/firmware/efi/arm-init.c | 8 | ||||
-rw-r--r-- | drivers/firmware/efi/efi-bgrt.c | 22 | ||||
-rw-r--r-- | drivers/firmware/efi/efi.c | 42 | ||||
-rw-r--r-- | drivers/firmware/efi/esrt.c | 2 | ||||
-rw-r--r-- | drivers/firmware/efi/libstub/Makefile | 3 | ||||
-rw-r--r-- | drivers/firmware/efi/libstub/arm-stub.c | 3 | ||||
-rw-r--r-- | drivers/firmware/efi/libstub/arm64-stub.c | 10 | ||||
-rw-r--r-- | drivers/firmware/efi/libstub/random.c | 10 | ||||
-rw-r--r-- | drivers/firmware/efi/libstub/tpm.c | 58 | ||||
-rw-r--r-- | drivers/firmware/efi/reboot.c | 12 |
12 files changed, 142 insertions, 40 deletions
diff --git a/drivers/firmware/dcdbas.c b/drivers/firmware/dcdbas.c index 2fe1a13..c16600f 100644 --- a/drivers/firmware/dcdbas.c +++ b/drivers/firmware/dcdbas.c @@ -534,7 +534,7 @@ static struct attribute *dcdbas_dev_attrs[] = { NULL }; -static struct attribute_group dcdbas_attr_group = { +static const struct attribute_group dcdbas_attr_group = { .attrs = dcdbas_dev_attrs, .bin_attrs = dcdbas_bin_attrs, }; diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig index 394db40..2b4c39f 100644 --- a/drivers/firmware/efi/Kconfig +++ b/drivers/firmware/efi/Kconfig @@ -151,6 +151,16 @@ config APPLE_PROPERTIES If unsure, say Y if you have a Mac. Otherwise N. +config RESET_ATTACK_MITIGATION + bool "Reset memory attack mitigation" + depends on EFI_STUB + help + Request that the firmware clear the contents of RAM after a reboot + using the TCG Platform Reset Attack Mitigation specification. This + protects against an attacker forcibly rebooting the system while it + still contains secrets in RAM, booting another OS and extracting the + secrets. + endmenu config UEFI_CPER diff --git a/drivers/firmware/efi/arm-init.c b/drivers/firmware/efi/arm-init.c index 1027d7b4..80d1a88 100644 --- a/drivers/firmware/efi/arm-init.c +++ b/drivers/firmware/efi/arm-init.c @@ -145,6 +145,9 @@ static int __init uefi_init(void) sizeof(efi_config_table_t), arch_tables); + if (!retval) + efi.config_table = (unsigned long)efi.systab->tables; + early_memunmap(config_tables, table_size); out: early_memunmap(efi.systab, sizeof(efi_system_table_t)); @@ -159,6 +162,7 @@ static __init int is_usable_memory(efi_memory_desc_t *md) switch (md->type) { case EFI_LOADER_CODE: case EFI_LOADER_DATA: + case EFI_ACPI_RECLAIM_MEMORY: case EFI_BOOT_SERVICES_CODE: case EFI_BOOT_SERVICES_DATA: case EFI_CONVENTIONAL_MEMORY: @@ -211,6 +215,10 @@ static __init void reserve_regions(void) if (!is_usable_memory(md)) memblock_mark_nomap(paddr, size); + + /* keep ACPI reclaim memory intact for kexec etc. */ + if (md->type == EFI_ACPI_RECLAIM_MEMORY) + memblock_reserve(paddr, size); } } } diff --git a/drivers/firmware/efi/efi-bgrt.c b/drivers/firmware/efi/efi-bgrt.c index b58233e..50793fd 100644 --- a/drivers/firmware/efi/efi-bgrt.c +++ b/drivers/firmware/efi/efi-bgrt.c @@ -27,26 +27,6 @@ struct bmp_header { u32 size; } __packed; -static bool efi_bgrt_addr_valid(u64 addr) -{ - efi_memory_desc_t *md; - - for_each_efi_memory_desc(md) { - u64 size; - u64 end; - - if (md->type != EFI_BOOT_SERVICES_DATA) - continue; - - size = md->num_pages << EFI_PAGE_SHIFT; - end = md->phys_addr + size; - if (addr >= md->phys_addr && addr < end) - return true; - } - - return false; -} - void __init efi_bgrt_init(struct acpi_table_header *table) { void *image; @@ -85,7 +65,7 @@ void __init efi_bgrt_init(struct acpi_table_header *table) goto out; } - if (!efi_bgrt_addr_valid(bgrt->image_address)) { + if (efi_mem_type(bgrt->image_address) != EFI_BOOT_SERVICES_DATA) { pr_notice("Ignoring BGRT: invalid image address\n"); goto out; } diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index 69d4d13..f70febf 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -198,7 +198,7 @@ static umode_t efi_attr_is_visible(struct kobject *kobj, return attr->mode; } -static struct attribute_group efi_subsys_attr_group = { +static const struct attribute_group efi_subsys_attr_group = { .attrs = efi_subsys_attrs, .is_visible = efi_attr_is_visible, }; @@ -541,6 +541,7 @@ int __init efi_config_parse_tables(void *config_tables, int count, int sz, if (seed != NULL) { add_device_randomness(seed->bits, seed->size); early_memunmap(seed, sizeof(*seed) + size); + pr_notice("seeding entropy pool\n"); } else { pr_err("Could not map UEFI random seed!\n"); } @@ -810,19 +811,19 @@ char * __init efi_md_typeattr_format(char *buf, size_t size, } /* + * IA64 has a funky EFI memory map that doesn't work the same way as + * other architectures. + */ +#ifndef CONFIG_IA64 +/* * efi_mem_attributes - lookup memmap attributes for physical address * @phys_addr: the physical address to lookup * * Search in the EFI memory map for the region covering * @phys_addr. Returns the EFI memory attributes if the region * was found in the memory map, 0 otherwise. - * - * Despite being marked __weak, most architectures should *not* - * override this function. It is __weak solely for the benefit - * of ia64 which has a funky EFI memory map that doesn't work - * the same way as other architectures. */ -u64 __weak efi_mem_attributes(unsigned long phys_addr) +u64 efi_mem_attributes(unsigned long phys_addr) { efi_memory_desc_t *md; @@ -838,6 +839,31 @@ u64 __weak efi_mem_attributes(unsigned long phys_addr) return 0; } +/* + * efi_mem_type - lookup memmap type for physical address + * @phys_addr: the physical address to lookup + * + * Search in the EFI memory map for the region covering @phys_addr. + * Returns the EFI memory type if the region was found in the memory + * map, EFI_RESERVED_TYPE (zero) otherwise. + */ +int efi_mem_type(unsigned long phys_addr) +{ + const efi_memory_desc_t *md; + + if (!efi_enabled(EFI_MEMMAP)) + return -ENOTSUPP; + + for_each_efi_memory_desc(md) { + if ((md->phys_addr <= phys_addr) && + (phys_addr < (md->phys_addr + + (md->num_pages << EFI_PAGE_SHIFT)))) + return md->type; + } + return -EINVAL; +} +#endif + int efi_status_to_err(efi_status_t status) { int err; @@ -900,7 +926,7 @@ static int update_efi_random_seed(struct notifier_block *nb, seed = memremap(efi.rng_seed, sizeof(*seed), MEMREMAP_WB); if (seed != NULL) { - size = min(seed->size, 32U); + size = min(seed->size, EFI_RANDOM_SEED_SIZE); memunmap(seed); } else { pr_err("Could not map UEFI random seed!\n"); diff --git a/drivers/firmware/efi/esrt.c b/drivers/firmware/efi/esrt.c index 8554d7a..bd7ed3c 100644 --- a/drivers/firmware/efi/esrt.c +++ b/drivers/firmware/efi/esrt.c @@ -230,7 +230,7 @@ static umode_t esrt_attr_is_visible(struct kobject *kobj, return attr->mode; } -static struct attribute_group esrt_attr_group = { +static const struct attribute_group esrt_attr_group = { .attrs = esrt_attrs, .is_visible = esrt_attr_is_visible, }; diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile index 37e24f5..dedf9bd 100644 --- a/drivers/firmware/efi/libstub/Makefile +++ b/drivers/firmware/efi/libstub/Makefile @@ -10,7 +10,7 @@ cflags-$(CONFIG_X86) += -m$(BITS) -D__KERNEL__ -O2 \ -fPIC -fno-strict-aliasing -mno-red-zone \ -mno-mmx -mno-sse -cflags-$(CONFIG_ARM64) := $(subst -pg,,$(KBUILD_CFLAGS)) +cflags-$(CONFIG_ARM64) := $(subst -pg,,$(KBUILD_CFLAGS)) -fpie cflags-$(CONFIG_ARM) := $(subst -pg,,$(KBUILD_CFLAGS)) \ -fno-builtin -fpic -mno-single-pic-base @@ -30,6 +30,7 @@ OBJECT_FILES_NON_STANDARD := y KCOV_INSTRUMENT := n lib-y := efi-stub-helper.o gop.o secureboot.o +lib-$(CONFIG_RESET_ATTACK_MITIGATION) += tpm.o # include the stub's generic dependencies from lib/ when building for ARM/arm64 arm-deps := fdt_rw.c fdt_ro.c fdt_wip.c fdt.c fdt_empty_tree.c fdt_sw.c sort.c diff --git a/drivers/firmware/efi/libstub/arm-stub.c b/drivers/firmware/efi/libstub/arm-stub.c index 8181ac1..1cb2d1c 100644 --- a/drivers/firmware/efi/libstub/arm-stub.c +++ b/drivers/firmware/efi/libstub/arm-stub.c @@ -192,6 +192,9 @@ unsigned long efi_entry(void *handle, efi_system_table_t *sys_table, goto fail_free_cmdline; } + /* Ask the firmware to clear memory on unclean shutdown */ + efi_enable_reset_attack_mitigation(sys_table); + secure_boot = efi_get_secureboot(sys_table); /* diff --git a/drivers/firmware/efi/libstub/arm64-stub.c b/drivers/firmware/efi/libstub/arm64-stub.c index af6ae95..b9bd827 100644 --- a/drivers/firmware/efi/libstub/arm64-stub.c +++ b/drivers/firmware/efi/libstub/arm64-stub.c @@ -9,10 +9,18 @@ * published by the Free Software Foundation. * */ + +/* + * To prevent the compiler from emitting GOT-indirected (and thus absolute) + * references to the section markers, override their visibility as 'hidden' + */ +#pragma GCC visibility push(hidden) +#include <asm/sections.h> +#pragma GCC visibility pop + #include <linux/efi.h> #include <asm/efi.h> #include <asm/memory.h> -#include <asm/sections.h> #include <asm/sysreg.h> #include "efistub.h" diff --git a/drivers/firmware/efi/libstub/random.c b/drivers/firmware/efi/libstub/random.c index 7e72954..e0e603a 100644 --- a/drivers/firmware/efi/libstub/random.c +++ b/drivers/firmware/efi/libstub/random.c @@ -145,8 +145,6 @@ efi_status_t efi_random_alloc(efi_system_table_t *sys_table_arg, return status; } -#define RANDOM_SEED_SIZE 32 - efi_status_t efi_random_get_seed(efi_system_table_t *sys_table_arg) { efi_guid_t rng_proto = EFI_RNG_PROTOCOL_GUID; @@ -162,25 +160,25 @@ efi_status_t efi_random_get_seed(efi_system_table_t *sys_table_arg) return status; status = efi_call_early(allocate_pool, EFI_RUNTIME_SERVICES_DATA, - sizeof(*seed) + RANDOM_SEED_SIZE, + sizeof(*seed) + EFI_RANDOM_SEED_SIZE, (void **)&seed); if (status != EFI_SUCCESS) return status; - status = rng->get_rng(rng, &rng_algo_raw, RANDOM_SEED_SIZE, + status = rng->get_rng(rng, &rng_algo_raw, EFI_RANDOM_SEED_SIZE, seed->bits); if (status == EFI_UNSUPPORTED) /* * Use whatever algorithm we have available if the raw algorithm * is not implemented. */ - status = rng->get_rng(rng, NULL, RANDOM_SEED_SIZE, + status = rng->get_rng(rng, NULL, EFI_RANDOM_SEED_SIZE, seed->bits); if (status != EFI_SUCCESS) goto err_freepool; - seed->size = RANDOM_SEED_SIZE; + seed->size = EFI_RANDOM_SEED_SIZE; status = efi_call_early(install_configuration_table, &rng_table_guid, seed); if (status != EFI_SUCCESS) diff --git a/drivers/firmware/efi/libstub/tpm.c b/drivers/firmware/efi/libstub/tpm.c new file mode 100644 index 0000000..6224cdb --- /dev/null +++ b/drivers/firmware/efi/libstub/tpm.c @@ -0,0 +1,58 @@ +/* + * TPM handling. + * + * Copyright (C) 2016 CoreOS, Inc + * Copyright (C) 2017 Google, Inc. + * Matthew Garrett <mjg59@google.com> + * + * This file is part of the Linux kernel, and is made available under the + * terms of the GNU General Public License version 2. + */ +#include <linux/efi.h> +#include <asm/efi.h> + +#include "efistub.h" + +static const efi_char16_t efi_MemoryOverWriteRequest_name[] = { + 'M', 'e', 'm', 'o', 'r', 'y', 'O', 'v', 'e', 'r', 'w', 'r', 'i', 't', + 'e', 'R', 'e', 'q', 'u', 'e', 's', 't', 'C', 'o', 'n', 't', 'r', 'o', + 'l', 0 +}; + +#define MEMORY_ONLY_RESET_CONTROL_GUID \ + EFI_GUID(0xe20939be, 0x32d4, 0x41be, 0xa1, 0x50, 0x89, 0x7f, 0x85, 0xd4, 0x98, 0x29) + +#define get_efi_var(name, vendor, ...) \ + efi_call_runtime(get_variable, \ + (efi_char16_t *)(name), (efi_guid_t *)(vendor), \ + __VA_ARGS__) + +#define set_efi_var(name, vendor, ...) \ + efi_call_runtime(set_variable, \ + (efi_char16_t *)(name), (efi_guid_t *)(vendor), \ + __VA_ARGS__) + +/* + * Enable reboot attack mitigation. This requests that the firmware clear the + * RAM on next reboot before proceeding with boot, ensuring that any secrets + * are cleared. If userland has ensured that all secrets have been removed + * from RAM before reboot it can simply reset this variable. + */ +void efi_enable_reset_attack_mitigation(efi_system_table_t *sys_table_arg) +{ + u8 val = 1; + efi_guid_t var_guid = MEMORY_ONLY_RESET_CONTROL_GUID; + efi_status_t status; + unsigned long datasize = 0; + + status = get_efi_var(efi_MemoryOverWriteRequest_name, &var_guid, + NULL, &datasize, NULL); + + if (status == EFI_NOT_FOUND) + return; + + set_efi_var(efi_MemoryOverWriteRequest_name, &var_guid, + EFI_VARIABLE_NON_VOLATILE | + EFI_VARIABLE_BOOTSERVICE_ACCESS | + EFI_VARIABLE_RUNTIME_ACCESS, sizeof(val), &val); +} diff --git a/drivers/firmware/efi/reboot.c b/drivers/firmware/efi/reboot.c index 62ead9b..2287454 100644 --- a/drivers/firmware/efi/reboot.c +++ b/drivers/firmware/efi/reboot.c @@ -5,6 +5,8 @@ #include <linux/efi.h> #include <linux/reboot.h> +static void (*orig_pm_power_off)(void); + int efi_reboot_quirk_mode = -1; void efi_reboot(enum reboot_mode reboot_mode, const char *__unused) @@ -51,6 +53,12 @@ bool __weak efi_poweroff_required(void) static void efi_power_off(void) { efi.reset_system(EFI_RESET_SHUTDOWN, EFI_SUCCESS, 0, NULL); + /* + * The above call should not return, if it does fall back to + * the original power off method (typically ACPI poweroff). + */ + if (orig_pm_power_off) + orig_pm_power_off(); } static int __init efi_shutdown_init(void) @@ -58,8 +66,10 @@ static int __init efi_shutdown_init(void) if (!efi_enabled(EFI_RUNTIME_SERVICES)) return -ENODEV; - if (efi_poweroff_required()) + if (efi_poweroff_required()) { + orig_pm_power_off = pm_power_off; pm_power_off = efi_power_off; + } return 0; } |