summaryrefslogtreecommitdiff
path: root/drivers/firmware
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2017-09-07 19:42:35 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2017-09-07 19:42:35 +0300
commitf92e3da18b7d5941468040af962c201235148301 (patch)
tree45b05ba50dfe4c5de9cf99b889297a6b51449a8b /drivers/firmware
parent57e88b43b81301d9b28f124a5576ac43a1cf9e8d (diff)
parent6de47a5e371f75f80544986e6c9636211a2ae8af (diff)
downloadlinux-f92e3da18b7d5941468040af962c201235148301.tar.xz
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.c2
-rw-r--r--drivers/firmware/efi/Kconfig10
-rw-r--r--drivers/firmware/efi/arm-init.c8
-rw-r--r--drivers/firmware/efi/efi-bgrt.c22
-rw-r--r--drivers/firmware/efi/efi.c42
-rw-r--r--drivers/firmware/efi/esrt.c2
-rw-r--r--drivers/firmware/efi/libstub/Makefile3
-rw-r--r--drivers/firmware/efi/libstub/arm-stub.c3
-rw-r--r--drivers/firmware/efi/libstub/arm64-stub.c10
-rw-r--r--drivers/firmware/efi/libstub/random.c10
-rw-r--r--drivers/firmware/efi/libstub/tpm.c58
-rw-r--r--drivers/firmware/efi/reboot.c12
12 files changed, 142 insertions, 40 deletions
diff --git a/drivers/firmware/dcdbas.c b/drivers/firmware/dcdbas.c
index 2fe1a130189f..c16600f30611 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 394db40ed374..2b4c39fdfa91 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 1027d7b44358..80d1a885def5 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 b58233e4ed71..50793fda7819 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 69d4d130e055..f70febf680c3 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 8554d7aec31c..bd7ed3c1148a 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 37e24f525162..dedf9bde44db 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 8181ac179d14..1cb2d1c070c3 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 af6ae95a5e34..b9bd827caa22 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 7e72954d5860..e0e603a89aa9 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 000000000000..6224cdbc9669
--- /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 62ead9b9d871..22874544d301 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;
}