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Subject[GIT PULL] EFI changes for v4.14
Linus,

Please pull the latest efi-core-for-linus git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git efi-core-for-linus

# HEAD: 6de47a5e371f75f80544986e6c9636211a2ae8af efi/bgrt: Use efi_mem_type()

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.

Thanks,

Ingo

------------------>
Ard Biesheuvel (11):
efi/arm: Don't mark ACPI reclaim memory as MEMBLOCK_NOMAP
efi/libstub/arm64: Use hidden attribute for struct screen_info reference
efi/libstub/arm64: Force 'hidden' visibility for section markers
efi/libstub/arm64: Set -fpie when building the EFI stub
efi/arm/arm64: Add missing assignment of efi.config_table
drivers/fbdev/efifb: Allow BAR to be moved instead of claiming it
arm/efi: Remove forbidden values from the PE/COFF header
arm/efi: Remove pointless dummy .reloc section
arm/efi: Replace open coded constants with symbolic ones
arm/efi: Split zImage code and data into separate PE/COFF sections
efi/random: Increase size of firmware supplied randomness

Arvind Yadav (3):
firmware/dcdbas: Constify attribute_group structures
firmware/efi: Constify attribute_group structures
firmware/efi/esrt: Constify attribute_group structures

Colin Ian King (1):
efi/reboot: Make function pointer orig_pm_power_off static

Hans de Goede (1):
efi/reboot: Fall back to original power-off method if EFI_RESET_SHUTDOWN returns

Jan Beulich (2):
efi: Move efi_mem_type() to common code
efi/bgrt: Use efi_mem_type()

Matthew Garrett (1):
efi/libstub: Enable reset attack mitigation


arch/arm/boot/compressed/efi-header.S | 160 +++++++++++++++---------------
arch/arm/boot/compressed/vmlinux.lds.S | 30 ++++--
arch/arm64/include/asm/efi.h | 3 +
arch/x86/boot/compressed/eboot.c | 3 +
arch/x86/platform/efi/efi.c | 19 ----
drivers/firmware/dcdbas.c | 2 +-
drivers/firmware/efi/Kconfig | 10 ++
drivers/firmware/efi/arm-init.c | 8 ++
drivers/firmware/efi/efi-bgrt.c | 22 +---
drivers/firmware/efi/efi.c | 42 ++++++--
drivers/firmware/efi/esrt.c | 2 +-
drivers/firmware/efi/libstub/Makefile | 3 +-
drivers/firmware/efi/libstub/arm-stub.c | 3 +
drivers/firmware/efi/libstub/arm64-stub.c | 10 +-
drivers/firmware/efi/libstub/random.c | 10 +-
drivers/firmware/efi/libstub/tpm.c | 58 +++++++++++
drivers/firmware/efi/reboot.c | 12 ++-
drivers/video/fbdev/efifb.c | 31 +++---
include/linux/efi.h | 9 ++
19 files changed, 280 insertions(+), 157 deletions(-)
create mode 100644 drivers/firmware/efi/libstub/tpm.c

diff --git a/arch/arm/boot/compressed/efi-header.S b/arch/arm/boot/compressed/efi-header.S
index a17ca8d78656..c94a88ae834d 100644
--- a/arch/arm/boot/compressed/efi-header.S
+++ b/arch/arm/boot/compressed/efi-header.S
@@ -1,5 +1,5 @@
/*
- * Copyright (C) 2013-2015 Linaro Ltd
+ * Copyright (C) 2013-2017 Linaro Ltd
* Authors: Roy Franz <roy.franz@linaro.org>
* Ard Biesheuvel <ard.biesheuvel@linaro.org>
*
@@ -8,6 +8,9 @@
* published by the Free Software Foundation.
*/

+#include <linux/pe.h>
+#include <linux/sizes.h>
+
.macro __nop
#ifdef CONFIG_EFI_STUB
@ This is almost but not quite a NOP, since it does clobber the
@@ -15,7 +18,7 @@
@ PE/COFF expects the magic string "MZ" at offset 0, while the
@ ARM/Linux boot protocol expects an executable instruction
@ there.
- .inst 'M' | ('Z' << 8) | (0x1310 << 16) @ tstne r0, #0x4d000
+ .inst MZ_MAGIC | (0x1310 << 16) @ tstne r0, #0x4d000
#else
AR_CLASS( mov r0, r0 )
M_CLASS( nop.w )
@@ -34,96 +37,97 @@
@ The only 2 fields of the MSDOS header that are used are this
@ PE/COFF offset, and the "MZ" bytes at offset 0x0.
@
- .long pe_header - start @ Offset to the PE header.
+ .long pe_header - start @ Offset to the PE header.

pe_header:
- .ascii "PE\0\0"
+ .long PE_MAGIC

coff_header:
- .short 0x01c2 @ ARM or Thumb
- .short 2 @ nr_sections
- .long 0 @ TimeDateStamp
- .long 0 @ PointerToSymbolTable
- .long 1 @ NumberOfSymbols
- .short section_table - optional_header
- @ SizeOfOptionalHeader
- .short 0x306 @ Characteristics.
- @ IMAGE_FILE_32BIT_MACHINE |
- @ IMAGE_FILE_DEBUG_STRIPPED |
- @ IMAGE_FILE_EXECUTABLE_IMAGE |
- @ IMAGE_FILE_LINE_NUMS_STRIPPED
+ .short IMAGE_FILE_MACHINE_THUMB @ Machine
+ .short section_count @ NumberOfSections
+ .long 0 @ TimeDateStamp
+ .long 0 @ PointerToSymbolTable
+ .long 0 @ NumberOfSymbols
+ .short section_table - optional_header @ SizeOfOptionalHeader
+ .short IMAGE_FILE_32BIT_MACHINE | \
+ IMAGE_FILE_DEBUG_STRIPPED | \
+ IMAGE_FILE_EXECUTABLE_IMAGE | \
+ IMAGE_FILE_LINE_NUMS_STRIPPED @ Characteristics
+
+#define __pecoff_code_size (__pecoff_data_start - __efi_start)

optional_header:
- .short 0x10b @ PE32 format
- .byte 0x02 @ MajorLinkerVersion
- .byte 0x14 @ MinorLinkerVersion
- .long _end - __efi_start @ SizeOfCode
- .long 0 @ SizeOfInitializedData
- .long 0 @ SizeOfUninitializedData
- .long efi_stub_entry - start @ AddressOfEntryPoint
- .long start_offset @ BaseOfCode
- .long 0 @ data
+ .short PE_OPT_MAGIC_PE32 @ PE32 format
+ .byte 0x02 @ MajorLinkerVersion
+ .byte 0x14 @ MinorLinkerVersion
+ .long __pecoff_code_size @ SizeOfCode
+ .long __pecoff_data_size @ SizeOfInitializedData
+ .long 0 @ SizeOfUninitializedData
+ .long efi_stub_entry - start @ AddressOfEntryPoint
+ .long start_offset @ BaseOfCode
+ .long __pecoff_data_start - start @ BaseOfData

extra_header_fields:
- .long 0 @ ImageBase
- .long 0x200 @ SectionAlignment
- .long 0x200 @ FileAlignment
- .short 0 @ MajorOperatingSystemVersion
- .short 0 @ MinorOperatingSystemVersion
- .short 0 @ MajorImageVersion
- .short 0 @ MinorImageVersion
- .short 0 @ MajorSubsystemVersion
- .short 0 @ MinorSubsystemVersion
- .long 0 @ Win32VersionValue
+ .long 0 @ ImageBase
+ .long SZ_4K @ SectionAlignment
+ .long SZ_512 @ FileAlignment
+ .short 0 @ MajorOsVersion
+ .short 0 @ MinorOsVersion
+ .short 0 @ MajorImageVersion
+ .short 0 @ MinorImageVersion
+ .short 0 @ MajorSubsystemVersion
+ .short 0 @ MinorSubsystemVersion
+ .long 0 @ Win32VersionValue

- .long _end - start @ SizeOfImage
- .long start_offset @ SizeOfHeaders
- .long 0 @ CheckSum
- .short 0xa @ Subsystem (EFI application)
- .short 0 @ DllCharacteristics
- .long 0 @ SizeOfStackReserve
- .long 0 @ SizeOfStackCommit
- .long 0 @ SizeOfHeapReserve
- .long 0 @ SizeOfHeapCommit
- .long 0 @ LoaderFlags
- .long 0x6 @ NumberOfRvaAndSizes
+ .long __pecoff_end - start @ SizeOfImage
+ .long start_offset @ SizeOfHeaders
+ .long 0 @ CheckSum
+ .short IMAGE_SUBSYSTEM_EFI_APPLICATION @ Subsystem
+ .short 0 @ DllCharacteristics
+ .long 0 @ SizeOfStackReserve
+ .long 0 @ SizeOfStackCommit
+ .long 0 @ SizeOfHeapReserve
+ .long 0 @ SizeOfHeapCommit
+ .long 0 @ LoaderFlags
+ .long (section_table - .) / 8 @ NumberOfRvaAndSizes

- .quad 0 @ ExportTable
- .quad 0 @ ImportTable
- .quad 0 @ ResourceTable
- .quad 0 @ ExceptionTable
- .quad 0 @ CertificationTable
- .quad 0 @ BaseRelocationTable
+ .quad 0 @ ExportTable
+ .quad 0 @ ImportTable
+ .quad 0 @ ResourceTable
+ .quad 0 @ ExceptionTable
+ .quad 0 @ CertificationTable
+ .quad 0 @ BaseRelocationTable

section_table:
- @
- @ The EFI application loader requires a relocation section
- @ because EFI applications must be relocatable. This is a
- @ dummy section as far as we are concerned.
- @
- .ascii ".reloc\0\0"
- .long 0 @ VirtualSize
- .long 0 @ VirtualAddress
- .long 0 @ SizeOfRawData
- .long 0 @ PointerToRawData
- .long 0 @ PointerToRelocations
- .long 0 @ PointerToLineNumbers
- .short 0 @ NumberOfRelocations
- .short 0 @ NumberOfLineNumbers
- .long 0x42100040 @ Characteristics
-
.ascii ".text\0\0\0"
- .long _end - __efi_start @ VirtualSize
- .long __efi_start @ VirtualAddress
- .long _edata - __efi_start @ SizeOfRawData
- .long __efi_start @ PointerToRawData
- .long 0 @ PointerToRelocations
- .long 0 @ PointerToLineNumbers
- .short 0 @ NumberOfRelocations
- .short 0 @ NumberOfLineNumbers
- .long 0xe0500020 @ Characteristics
+ .long __pecoff_code_size @ VirtualSize
+ .long __efi_start @ VirtualAddress
+ .long __pecoff_code_size @ SizeOfRawData
+ .long __efi_start @ PointerToRawData
+ .long 0 @ PointerToRelocations
+ .long 0 @ PointerToLineNumbers
+ .short 0 @ NumberOfRelocations
+ .short 0 @ NumberOfLineNumbers
+ .long IMAGE_SCN_CNT_CODE | \
+ IMAGE_SCN_MEM_READ | \
+ IMAGE_SCN_MEM_EXECUTE @ Characteristics
+
+ .ascii ".data\0\0\0"
+ .long __pecoff_data_size @ VirtualSize
+ .long __pecoff_data_start - start @ VirtualAddress
+ .long __pecoff_data_rawsize @ SizeOfRawData
+ .long __pecoff_data_start - start @ PointerToRawData
+ .long 0 @ PointerToRelocations
+ .long 0 @ PointerToLineNumbers
+ .short 0 @ NumberOfRelocations
+ .short 0 @ NumberOfLineNumbers
+ .long IMAGE_SCN_CNT_INITIALIZED_DATA | \
+ IMAGE_SCN_MEM_READ | \
+ IMAGE_SCN_MEM_WRITE @ Characteristics
+
+ .set section_count, (. - section_table) / 40

- .align 9
+ .align 12
__efi_start:
#endif
.endm
diff --git a/arch/arm/boot/compressed/vmlinux.lds.S b/arch/arm/boot/compressed/vmlinux.lds.S
index 81c493156ce8..7a4c59154361 100644
--- a/arch/arm/boot/compressed/vmlinux.lds.S
+++ b/arch/arm/boot/compressed/vmlinux.lds.S
@@ -48,13 +48,6 @@ SECTIONS
*(.rodata)
*(.rodata.*)
}
- .data : {
- /*
- * The EFI stub always executes from RAM, and runs strictly before the
- * decompressor, so we can make an exception for its r/w data, and keep it
- */
- *(.data.efistub)
- }
.piggydata : {
*(.piggydata)
}
@@ -70,6 +63,26 @@ SECTIONS
/* ensure the zImage file size is always a multiple of 64 bits */
/* (without a dummy byte, ld just ignores the empty section) */
.pad : { BYTE(0); . = ALIGN(8); }
+
+#ifdef CONFIG_EFI_STUB
+ .data : ALIGN(4096) {
+ __pecoff_data_start = .;
+ /*
+ * The EFI stub always executes from RAM, and runs strictly before the
+ * decompressor, so we can make an exception for its r/w data, and keep it
+ */
+ *(.data.efistub)
+ __pecoff_data_end = .;
+
+ /*
+ * PE/COFF mandates a file size which is a multiple of 512 bytes if the
+ * section size equals or exceeds 4 KB
+ */
+ . = ALIGN(512);
+ }
+ __pecoff_data_rawsize = . - ADDR(.data);
+#endif
+
_edata = .;

_magic_sig = ZIMAGE_MAGIC(0x016f2818);
@@ -84,6 +97,9 @@ SECTIONS
. = ALIGN(8); /* the stack must be 64-bit aligned */
.stack : { *(.stack) }

+ PROVIDE(__pecoff_data_size = ALIGN(512) - ADDR(.data));
+ PROVIDE(__pecoff_end = ALIGN(512));
+
.stab 0 : { *(.stab) }
.stabstr 0 : { *(.stabstr) }
.stab.excl 0 : { *(.stab.excl) }
diff --git a/arch/arm64/include/asm/efi.h b/arch/arm64/include/asm/efi.h
index 8f3043aba873..464ac850c5e2 100644
--- a/arch/arm64/include/asm/efi.h
+++ b/arch/arm64/include/asm/efi.h
@@ -81,6 +81,9 @@ static inline unsigned long efi_get_max_initrd_addr(unsigned long dram_base,
#define alloc_screen_info(x...) &screen_info
#define free_screen_info(x...)

+/* redeclare as 'hidden' so the compiler will generate relative references */
+extern struct screen_info screen_info __attribute__((__visibility__("hidden")));
+
static inline void efifb_setup_from_dmi(struct screen_info *si, const char *opt)
{
}
diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c
index c3e869eaef0c..a1686f3dc295 100644
--- a/arch/x86/boot/compressed/eboot.c
+++ b/arch/x86/boot/compressed/eboot.c
@@ -997,6 +997,9 @@ struct boot_params *efi_main(struct efi_config *c,
if (boot_params->secure_boot == efi_secureboot_mode_unset)
boot_params->secure_boot = efi_get_secureboot(sys_table);

+ /* Ask the firmware to clear memory on unclean shutdown */
+ efi_enable_reset_attack_mitigation(sys_table);
+
setup_graphics(boot_params);

setup_efi_pci(boot_params);
diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index 6217b23e85f6..928b6dceeca0 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -1032,25 +1032,6 @@ void __init efi_enter_virtual_mode(void)
efi_dump_pagetable();
}

-/*
- * Convenience functions to obtain memory types and attributes
- */
-int efi_mem_type(unsigned long phys_addr)
-{
- 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;
-}
-
static int __init arch_parse_efi_cmdline(char *str)
{
if (!str) {
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 b4c2589d7c91..f7a6970e9abc 100644
--- a/drivers/firmware/efi/libstub/arm64-stub.c
+++ b/drivers/firmware/efi/libstub/arm64-stub.c
@@ -9,9 +9,17 @@
* 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/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;
}
diff --git a/drivers/video/fbdev/efifb.c b/drivers/video/fbdev/efifb.c
index 1e784adb89b1..3a010641f630 100644
--- a/drivers/video/fbdev/efifb.c
+++ b/drivers/video/fbdev/efifb.c
@@ -149,6 +149,10 @@ ATTRIBUTE_GROUPS(efifb);

static bool pci_dev_disabled; /* FB base matches BAR of a disabled device */

+static struct pci_dev *efifb_pci_dev; /* dev with BAR covering the efifb */
+static struct resource *bar_resource;
+static u64 bar_offset;
+
static int efifb_probe(struct platform_device *dev)
{
struct fb_info *info;
@@ -203,6 +207,13 @@ static int efifb_probe(struct platform_device *dev)
efifb_fix.smem_start |= ext_lfb_base;
}

+ if (bar_resource &&
+ bar_resource->start + bar_offset != efifb_fix.smem_start) {
+ dev_info(&efifb_pci_dev->dev,
+ "BAR has moved, updating efifb address\n");
+ efifb_fix.smem_start = bar_resource->start + bar_offset;
+ }
+
efifb_defined.bits_per_pixel = screen_info.lfb_depth;
efifb_defined.xres = screen_info.lfb_width;
efifb_defined.yres = screen_info.lfb_height;
@@ -370,15 +381,13 @@ static struct platform_driver efifb_driver = {

builtin_platform_driver(efifb_driver);

-#if defined(CONFIG_PCI) && !defined(CONFIG_X86)
-
-static bool pci_bar_found; /* did we find a BAR matching the efifb base? */
+#if defined(CONFIG_PCI)

-static void claim_efifb_bar(struct pci_dev *dev, int idx)
+static void record_efifb_bar_resource(struct pci_dev *dev, int idx, u64 offset)
{
u16 word;

- pci_bar_found = true;
+ efifb_pci_dev = dev;

pci_read_config_word(dev, PCI_COMMAND, &word);
if (!(word & PCI_COMMAND_MEMORY)) {
@@ -389,12 +398,8 @@ static void claim_efifb_bar(struct pci_dev *dev, int idx)
return;
}

- if (pci_claim_resource(dev, idx)) {
- pci_dev_disabled = true;
- dev_err(&dev->dev,
- "BAR %d: failed to claim resource for efifb!\n", idx);
- return;
- }
+ bar_resource = &dev->resource[idx];
+ bar_offset = offset;

dev_info(&dev->dev, "BAR %d: assigned to efifb\n", idx);
}
@@ -405,7 +410,7 @@ static void efifb_fixup_resources(struct pci_dev *dev)
u64 size = screen_info.lfb_size;
int i;

- if (pci_bar_found || screen_info.orig_video_isVGA != VIDEO_TYPE_EFI)
+ if (efifb_pci_dev || screen_info.orig_video_isVGA != VIDEO_TYPE_EFI)
return;

if (screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE)
@@ -421,7 +426,7 @@ static void efifb_fixup_resources(struct pci_dev *dev)
continue;

if (res->start <= base && res->end >= base + size - 1) {
- claim_efifb_bar(dev, i);
+ record_efifb_bar_resource(dev, i, base - res->start);
break;
}
}
diff --git a/include/linux/efi.h b/include/linux/efi.h
index 4e47f78430be..33d41df062bc 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -1504,6 +1504,13 @@ enum efi_secureboot_mode {
};
enum efi_secureboot_mode efi_get_secureboot(efi_system_table_t *sys_table);

+#ifdef CONFIG_RESET_ATTACK_MITIGATION
+void efi_enable_reset_attack_mitigation(efi_system_table_t *sys_table_arg);
+#else
+static inline void
+efi_enable_reset_attack_mitigation(efi_system_table_t *sys_table_arg) { }
+#endif
+
/*
* Arch code can implement the following three template macros, avoiding
* reptition for the void/non-void return cases of {__,}efi_call_virt():
@@ -1564,6 +1571,8 @@ efi_status_t efi_exit_boot_services(efi_system_table_t *sys_table,
void *priv,
efi_exit_boot_map_processing priv_func);

+#define EFI_RANDOM_SEED_SIZE 64U
+
struct linux_efi_random_seed {
u32 size;
u8 bits[];
\
 
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  Last update: 2017-09-05 08:26    [W:0.080 / U:3.028 seconds]
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