diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
commit | 76cb841cb886eef6b3bee341a2266c76578724ad (patch) | |
tree | f5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /drivers/firmware/efi/libstub | |
parent | Initial commit. (diff) | |
download | linux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip |
Adding upstream version 4.19.249.upstream/4.19.249
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/firmware/efi/libstub')
-rw-r--r-- | drivers/firmware/efi/libstub/Makefile | 103 | ||||
-rw-r--r-- | drivers/firmware/efi/libstub/arm-stub.c | 379 | ||||
-rw-r--r-- | drivers/firmware/efi/libstub/arm32-stub.c | 249 | ||||
-rw-r--r-- | drivers/firmware/efi/libstub/arm64-stub.c | 159 | ||||
-rw-r--r-- | drivers/firmware/efi/libstub/efi-stub-helper.c | 931 | ||||
-rw-r--r-- | drivers/firmware/efi/libstub/efistub.h | 68 | ||||
-rw-r--r-- | drivers/firmware/efi/libstub/fdt.c | 394 | ||||
-rw-r--r-- | drivers/firmware/efi/libstub/gop.c | 314 | ||||
-rw-r--r-- | drivers/firmware/efi/libstub/random.c | 192 | ||||
-rw-r--r-- | drivers/firmware/efi/libstub/secureboot.c | 83 | ||||
-rw-r--r-- | drivers/firmware/efi/libstub/string.c | 58 | ||||
-rw-r--r-- | drivers/firmware/efi/libstub/tpm.c | 136 |
12 files changed, 3066 insertions, 0 deletions
diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile new file mode 100644 index 000000000..d3777d754 --- /dev/null +++ b/drivers/firmware/efi/libstub/Makefile @@ -0,0 +1,103 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# The stub may be linked into the kernel proper or into a separate boot binary, +# but in either case, it executes before the kernel does (with MMU disabled) so +# things like ftrace and stack-protector are likely to cause trouble if left +# enabled, even if doing so doesn't break the build. +# +cflags-$(CONFIG_X86_32) := -march=i386 +cflags-$(CONFIG_X86_64) := -mcmodel=small +cflags-$(CONFIG_X86) += -m$(BITS) -D__KERNEL__ -O2 \ + -fPIC -fno-strict-aliasing -mno-red-zone \ + -mno-mmx -mno-sse -fshort-wchar \ + -Wno-pointer-sign \ + $(call cc-disable-warning, address-of-packed-member) \ + $(call cc-disable-warning, gnu) + +# arm64 uses the full KBUILD_CFLAGS so it's necessary to explicitly +# disable the stackleak plugin +cflags-$(CONFIG_ARM64) := $(subst -pg,,$(KBUILD_CFLAGS)) -fpie \ + $(DISABLE_STACKLEAK_PLUGIN) +cflags-$(CONFIG_ARM) := $(subst -pg,,$(KBUILD_CFLAGS)) \ + -fno-builtin -fpic \ + $(call cc-option,-mno-single-pic-base) + +cflags-$(CONFIG_EFI_ARMSTUB) += -I$(srctree)/scripts/dtc/libfdt + +KBUILD_CFLAGS := $(cflags-y) -DDISABLE_BRANCH_PROFILING \ + -D__NO_FORTIFY \ + $(call cc-option,-ffreestanding) \ + $(call cc-option,-fno-stack-protector) \ + $(call cc-option,-fno-addrsig) \ + -D__DISABLE_EXPORTS + +GCOV_PROFILE := n +KASAN_SANITIZE := n +UBSAN_SANITIZE := n +OBJECT_FILES_NON_STANDARD := y + +# Prevents link failures: __sanitizer_cov_trace_pc() is not linked in. +KCOV_INSTRUMENT := n + +lib-y := efi-stub-helper.o gop.o secureboot.o tpm.o + +# include the stub's generic dependencies from lib/ when building for ARM/arm64 +arm-deps-y := fdt_rw.c fdt_ro.c fdt_wip.c fdt.c fdt_empty_tree.c fdt_sw.c +arm-deps-$(CONFIG_ARM64) += sort.c + +$(obj)/lib-%.o: $(srctree)/lib/%.c FORCE + $(call if_changed_rule,cc_o_c) + +lib-$(CONFIG_EFI_ARMSTUB) += arm-stub.o fdt.o string.o random.o \ + $(patsubst %.c,lib-%.o,$(arm-deps-y)) + +lib-$(CONFIG_ARM) += arm32-stub.o +lib-$(CONFIG_ARM64) += arm64-stub.o +CFLAGS_arm64-stub.o := -DTEXT_OFFSET=$(TEXT_OFFSET) + +# +# arm64 puts the stub in the kernel proper, which will unnecessarily retain all +# code indefinitely unless it is annotated as __init/__initdata/__initconst etc. +# So let's apply the __init annotations at the section level, by prefixing +# the section names directly. This will ensure that even all the inline string +# literals are covered. +# The fact that the stub and the kernel proper are essentially the same binary +# also means that we need to be extra careful to make sure that the stub does +# not rely on any absolute symbol references, considering that the virtual +# kernel mapping that the linker uses is not active yet when the stub is +# executing. So build all C dependencies of the EFI stub into libstub, and do +# a verification pass to see if any absolute relocations exist in any of the +# object files. +# +extra-$(CONFIG_EFI_ARMSTUB) := $(lib-y) +lib-$(CONFIG_EFI_ARMSTUB) := $(patsubst %.o,%.stub.o,$(lib-y)) + +STUBCOPY_RM-y := -R *ksymtab* -R *kcrctab* +STUBCOPY_FLAGS-$(CONFIG_ARM64) += --prefix-alloc-sections=.init \ + --prefix-symbols=__efistub_ +STUBCOPY_RELOC-$(CONFIG_ARM64) := R_AARCH64_ABS + +$(obj)/%.stub.o: $(obj)/%.o FORCE + $(call if_changed,stubcopy) + +# +# Strip debug sections and some other sections that may legally contain +# absolute relocations, so that we can inspect the remaining sections for +# such relocations. If none are found, regenerate the output object, but +# this time, use objcopy and leave all sections in place. +# +quiet_cmd_stubcopy = STUBCPY $@ + cmd_stubcopy = if $(STRIP) --strip-debug $(STUBCOPY_RM-y) -o $@ $<; \ + then if $(OBJDUMP) -r $@ | grep $(STUBCOPY_RELOC-y); \ + then (echo >&2 "$@: absolute symbol references not allowed in the EFI stub"; \ + rm -f $@; /bin/false); \ + else $(OBJCOPY) $(STUBCOPY_FLAGS-y) $< $@; fi \ + else /bin/false; fi + +# +# ARM discards the .data section because it disallows r/w data in the +# decompressor. So move our .data to .data.efistub, which is preserved +# explicitly by the decompressor linker script. +# +STUBCOPY_FLAGS-$(CONFIG_ARM) += --rename-section .data=.data.efistub +STUBCOPY_RELOC-$(CONFIG_ARM) := R_ARM_ABS diff --git a/drivers/firmware/efi/libstub/arm-stub.c b/drivers/firmware/efi/libstub/arm-stub.c new file mode 100644 index 000000000..6c09644d6 --- /dev/null +++ b/drivers/firmware/efi/libstub/arm-stub.c @@ -0,0 +1,379 @@ +/* + * EFI stub implementation that is shared by arm and arm64 architectures. + * This should be #included by the EFI stub implementation files. + * + * Copyright (C) 2013,2014 Linaro Limited + * Roy Franz <roy.franz@linaro.org + * Copyright (C) 2013 Red Hat, Inc. + * Mark Salter <msalter@redhat.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 <linux/sort.h> +#include <asm/efi.h> + +#include "efistub.h" + +/* + * This is the base address at which to start allocating virtual memory ranges + * for UEFI Runtime Services. This is in the low TTBR0 range so that we can use + * any allocation we choose, and eliminate the risk of a conflict after kexec. + * The value chosen is the largest non-zero power of 2 suitable for this purpose + * both on 32-bit and 64-bit ARM CPUs, to maximize the likelihood that it can + * be mapped efficiently. + * Since 32-bit ARM could potentially execute with a 1G/3G user/kernel split, + * map everything below 1 GB. (512 MB is a reasonable upper bound for the + * entire footprint of the UEFI runtime services memory regions) + */ +#define EFI_RT_VIRTUAL_BASE SZ_512M +#define EFI_RT_VIRTUAL_SIZE SZ_512M + +#ifdef CONFIG_ARM64 +# define EFI_RT_VIRTUAL_LIMIT TASK_SIZE_64 +#else +# define EFI_RT_VIRTUAL_LIMIT TASK_SIZE +#endif + +static u64 virtmap_base = EFI_RT_VIRTUAL_BASE; + +void efi_char16_printk(efi_system_table_t *sys_table_arg, + efi_char16_t *str) +{ + struct efi_simple_text_output_protocol *out; + + out = (struct efi_simple_text_output_protocol *)sys_table_arg->con_out; + out->output_string(out, str); +} + +static struct screen_info *setup_graphics(efi_system_table_t *sys_table_arg) +{ + efi_guid_t gop_proto = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID; + efi_status_t status; + unsigned long size; + void **gop_handle = NULL; + struct screen_info *si = NULL; + + size = 0; + status = efi_call_early(locate_handle, EFI_LOCATE_BY_PROTOCOL, + &gop_proto, NULL, &size, gop_handle); + if (status == EFI_BUFFER_TOO_SMALL) { + si = alloc_screen_info(sys_table_arg); + if (!si) + return NULL; + efi_setup_gop(sys_table_arg, si, &gop_proto, size); + } + return si; +} + +/* + * This function handles the architcture specific differences between arm and + * arm64 regarding where the kernel image must be loaded and any memory that + * must be reserved. On failure it is required to free all + * all allocations it has made. + */ +efi_status_t handle_kernel_image(efi_system_table_t *sys_table, + unsigned long *image_addr, + unsigned long *image_size, + unsigned long *reserve_addr, + unsigned long *reserve_size, + unsigned long dram_base, + efi_loaded_image_t *image); +/* + * EFI entry point for the arm/arm64 EFI stubs. This is the entrypoint + * that is described in the PE/COFF header. Most of the code is the same + * for both archictectures, with the arch-specific code provided in the + * handle_kernel_image() function. + */ +unsigned long efi_entry(void *handle, efi_system_table_t *sys_table, + unsigned long *image_addr) +{ + efi_loaded_image_t *image; + efi_status_t status; + unsigned long image_size = 0; + unsigned long dram_base; + /* addr/point and size pairs for memory management*/ + unsigned long initrd_addr; + u64 initrd_size = 0; + unsigned long fdt_addr = 0; /* Original DTB */ + unsigned long fdt_size = 0; + char *cmdline_ptr = NULL; + int cmdline_size = 0; + unsigned long new_fdt_addr; + efi_guid_t loaded_image_proto = LOADED_IMAGE_PROTOCOL_GUID; + unsigned long reserve_addr = 0; + unsigned long reserve_size = 0; + enum efi_secureboot_mode secure_boot; + struct screen_info *si; + + /* Check if we were booted by the EFI firmware */ + if (sys_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) + goto fail; + + status = check_platform_features(sys_table); + if (status != EFI_SUCCESS) + goto fail; + + /* + * Get a handle to the loaded image protocol. This is used to get + * information about the running image, such as size and the command + * line. + */ + status = sys_table->boottime->handle_protocol(handle, + &loaded_image_proto, (void *)&image); + if (status != EFI_SUCCESS) { + pr_efi_err(sys_table, "Failed to get loaded image protocol\n"); + goto fail; + } + + dram_base = get_dram_base(sys_table); + if (dram_base == EFI_ERROR) { + pr_efi_err(sys_table, "Failed to find DRAM base\n"); + goto fail; + } + + /* + * Get the command line from EFI, using the LOADED_IMAGE + * protocol. We are going to copy the command line into the + * device tree, so this can be allocated anywhere. + */ + cmdline_ptr = efi_convert_cmdline(sys_table, image, &cmdline_size); + if (!cmdline_ptr) { + pr_efi_err(sys_table, "getting command line via LOADED_IMAGE_PROTOCOL\n"); + goto fail; + } + + if (IS_ENABLED(CONFIG_CMDLINE_EXTEND) || + IS_ENABLED(CONFIG_CMDLINE_FORCE) || + cmdline_size == 0) + efi_parse_options(CONFIG_CMDLINE); + + if (!IS_ENABLED(CONFIG_CMDLINE_FORCE) && cmdline_size > 0) + efi_parse_options(cmdline_ptr); + + pr_efi(sys_table, "Booting Linux Kernel...\n"); + + si = setup_graphics(sys_table); + + status = handle_kernel_image(sys_table, image_addr, &image_size, + &reserve_addr, + &reserve_size, + dram_base, image); + if (status != EFI_SUCCESS) { + pr_efi_err(sys_table, "Failed to relocate kernel\n"); + 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); + + /* + * Unauthenticated device tree data is a security hazard, so ignore + * 'dtb=' unless UEFI Secure Boot is disabled. We assume that secure + * boot is enabled if we can't determine its state. + */ + if (!IS_ENABLED(CONFIG_EFI_ARMSTUB_DTB_LOADER) || + secure_boot != efi_secureboot_mode_disabled) { + if (strstr(cmdline_ptr, "dtb=")) + pr_efi(sys_table, "Ignoring DTB from command line.\n"); + } else { + status = handle_cmdline_files(sys_table, image, cmdline_ptr, + "dtb=", + ~0UL, &fdt_addr, &fdt_size); + + if (status != EFI_SUCCESS) { + pr_efi_err(sys_table, "Failed to load device tree!\n"); + goto fail_free_image; + } + } + + if (fdt_addr) { + pr_efi(sys_table, "Using DTB from command line\n"); + } else { + /* Look for a device tree configuration table entry. */ + fdt_addr = (uintptr_t)get_fdt(sys_table, &fdt_size); + if (fdt_addr) + pr_efi(sys_table, "Using DTB from configuration table\n"); + } + + if (!fdt_addr) + pr_efi(sys_table, "Generating empty DTB\n"); + + status = handle_cmdline_files(sys_table, image, cmdline_ptr, "initrd=", + efi_get_max_initrd_addr(dram_base, + *image_addr), + (unsigned long *)&initrd_addr, + (unsigned long *)&initrd_size); + if (status != EFI_SUCCESS) + pr_efi_err(sys_table, "Failed initrd from command line!\n"); + + efi_random_get_seed(sys_table); + + /* hibernation expects the runtime regions to stay in the same place */ + if (!IS_ENABLED(CONFIG_HIBERNATION) && !nokaslr()) { + /* + * Randomize the base of the UEFI runtime services region. + * Preserve the 2 MB alignment of the region by taking a + * shift of 21 bit positions into account when scaling + * the headroom value using a 32-bit random value. + */ + static const u64 headroom = EFI_RT_VIRTUAL_LIMIT - + EFI_RT_VIRTUAL_BASE - + EFI_RT_VIRTUAL_SIZE; + u32 rnd; + + status = efi_get_random_bytes(sys_table, sizeof(rnd), + (u8 *)&rnd); + if (status == EFI_SUCCESS) { + virtmap_base = EFI_RT_VIRTUAL_BASE + + (((headroom >> 21) * rnd) >> (32 - 21)); + } + } + + new_fdt_addr = fdt_addr; + status = allocate_new_fdt_and_exit_boot(sys_table, handle, + &new_fdt_addr, efi_get_max_fdt_addr(dram_base), + initrd_addr, initrd_size, cmdline_ptr, + fdt_addr, fdt_size); + + /* + * If all went well, we need to return the FDT address to the + * calling function so it can be passed to kernel as part of + * the kernel boot protocol. + */ + if (status == EFI_SUCCESS) + return new_fdt_addr; + + pr_efi_err(sys_table, "Failed to update FDT and exit boot services\n"); + + efi_free(sys_table, initrd_size, initrd_addr); + efi_free(sys_table, fdt_size, fdt_addr); + +fail_free_image: + efi_free(sys_table, image_size, *image_addr); + efi_free(sys_table, reserve_size, reserve_addr); +fail_free_cmdline: + free_screen_info(sys_table, si); + efi_free(sys_table, cmdline_size, (unsigned long)cmdline_ptr); +fail: + return EFI_ERROR; +} + +static int cmp_mem_desc(const void *l, const void *r) +{ + const efi_memory_desc_t *left = l, *right = r; + + return (left->phys_addr > right->phys_addr) ? 1 : -1; +} + +/* + * Returns whether region @left ends exactly where region @right starts, + * or false if either argument is NULL. + */ +static bool regions_are_adjacent(efi_memory_desc_t *left, + efi_memory_desc_t *right) +{ + u64 left_end; + + if (left == NULL || right == NULL) + return false; + + left_end = left->phys_addr + left->num_pages * EFI_PAGE_SIZE; + + return left_end == right->phys_addr; +} + +/* + * Returns whether region @left and region @right have compatible memory type + * mapping attributes, and are both EFI_MEMORY_RUNTIME regions. + */ +static bool regions_have_compatible_memory_type_attrs(efi_memory_desc_t *left, + efi_memory_desc_t *right) +{ + static const u64 mem_type_mask = EFI_MEMORY_WB | EFI_MEMORY_WT | + EFI_MEMORY_WC | EFI_MEMORY_UC | + EFI_MEMORY_RUNTIME; + + return ((left->attribute ^ right->attribute) & mem_type_mask) == 0; +} + +/* + * efi_get_virtmap() - create a virtual mapping for the EFI memory map + * + * This function populates the virt_addr fields of all memory region descriptors + * in @memory_map whose EFI_MEMORY_RUNTIME attribute is set. Those descriptors + * are also copied to @runtime_map, and their total count is returned in @count. + */ +void efi_get_virtmap(efi_memory_desc_t *memory_map, unsigned long map_size, + unsigned long desc_size, efi_memory_desc_t *runtime_map, + int *count) +{ + u64 efi_virt_base = virtmap_base; + efi_memory_desc_t *in, *prev = NULL, *out = runtime_map; + int l; + + /* + * To work around potential issues with the Properties Table feature + * introduced in UEFI 2.5, which may split PE/COFF executable images + * in memory into several RuntimeServicesCode and RuntimeServicesData + * regions, we need to preserve the relative offsets between adjacent + * EFI_MEMORY_RUNTIME regions with the same memory type attributes. + * The easiest way to find adjacent regions is to sort the memory map + * before traversing it. + */ + if (IS_ENABLED(CONFIG_ARM64)) + sort(memory_map, map_size / desc_size, desc_size, cmp_mem_desc, + NULL); + + for (l = 0; l < map_size; l += desc_size, prev = in) { + u64 paddr, size; + + in = (void *)memory_map + l; + if (!(in->attribute & EFI_MEMORY_RUNTIME)) + continue; + + paddr = in->phys_addr; + size = in->num_pages * EFI_PAGE_SIZE; + + if (novamap()) { + in->virt_addr = in->phys_addr; + continue; + } + + /* + * Make the mapping compatible with 64k pages: this allows + * a 4k page size kernel to kexec a 64k page size kernel and + * vice versa. + */ + if ((IS_ENABLED(CONFIG_ARM64) && + !regions_are_adjacent(prev, in)) || + !regions_have_compatible_memory_type_attrs(prev, in)) { + + paddr = round_down(in->phys_addr, SZ_64K); + size += in->phys_addr - paddr; + + /* + * Avoid wasting memory on PTEs by choosing a virtual + * base that is compatible with section mappings if this + * region has the appropriate size and physical + * alignment. (Sections are 2 MB on 4k granule kernels) + */ + if (IS_ALIGNED(in->phys_addr, SZ_2M) && size >= SZ_2M) + efi_virt_base = round_up(efi_virt_base, SZ_2M); + else + efi_virt_base = round_up(efi_virt_base, SZ_64K); + } + + in->virt_addr = efi_virt_base + in->phys_addr - paddr; + efi_virt_base += size; + + memcpy(out, in, desc_size); + out = (void *)out + desc_size; + ++*count; + } +} diff --git a/drivers/firmware/efi/libstub/arm32-stub.c b/drivers/firmware/efi/libstub/arm32-stub.c new file mode 100644 index 000000000..becbda445 --- /dev/null +++ b/drivers/firmware/efi/libstub/arm32-stub.c @@ -0,0 +1,249 @@ +/* + * Copyright (C) 2013 Linaro Ltd; <roy.franz@linaro.org> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + */ +#include <linux/efi.h> +#include <asm/efi.h> + +#include "efistub.h" + +efi_status_t check_platform_features(efi_system_table_t *sys_table_arg) +{ + int block; + + /* non-LPAE kernels can run anywhere */ + if (!IS_ENABLED(CONFIG_ARM_LPAE)) + return EFI_SUCCESS; + + /* LPAE kernels need compatible hardware */ + block = cpuid_feature_extract(CPUID_EXT_MMFR0, 0); + if (block < 5) { + pr_efi_err(sys_table_arg, "This LPAE kernel is not supported by your CPU\n"); + return EFI_UNSUPPORTED; + } + return EFI_SUCCESS; +} + +static efi_guid_t screen_info_guid = LINUX_EFI_ARM_SCREEN_INFO_TABLE_GUID; + +struct screen_info *alloc_screen_info(efi_system_table_t *sys_table_arg) +{ + struct screen_info *si; + efi_status_t status; + + /* + * Unlike on arm64, where we can directly fill out the screen_info + * structure from the stub, we need to allocate a buffer to hold + * its contents while we hand over to the kernel proper from the + * decompressor. + */ + status = efi_call_early(allocate_pool, EFI_RUNTIME_SERVICES_DATA, + sizeof(*si), (void **)&si); + + if (status != EFI_SUCCESS) + return NULL; + + status = efi_call_early(install_configuration_table, + &screen_info_guid, si); + if (status == EFI_SUCCESS) + return si; + + efi_call_early(free_pool, si); + return NULL; +} + +void free_screen_info(efi_system_table_t *sys_table_arg, struct screen_info *si) +{ + if (!si) + return; + + efi_call_early(install_configuration_table, &screen_info_guid, NULL); + efi_call_early(free_pool, si); +} + +static efi_status_t reserve_kernel_base(efi_system_table_t *sys_table_arg, + unsigned long dram_base, + unsigned long *reserve_addr, + unsigned long *reserve_size) +{ + efi_physical_addr_t alloc_addr; + efi_memory_desc_t *memory_map; + unsigned long nr_pages, map_size, desc_size, buff_size; + efi_status_t status; + unsigned long l; + + struct efi_boot_memmap map = { + .map = &memory_map, + .map_size = &map_size, + .desc_size = &desc_size, + .desc_ver = NULL, + .key_ptr = NULL, + .buff_size = &buff_size, + }; + + /* + * Reserve memory for the uncompressed kernel image. This is + * all that prevents any future allocations from conflicting + * with the kernel. Since we can't tell from the compressed + * image how much DRAM the kernel actually uses (due to BSS + * size uncertainty) we allocate the maximum possible size. + * Do this very early, as prints can cause memory allocations + * that may conflict with this. + */ + alloc_addr = dram_base + MAX_UNCOMP_KERNEL_SIZE; + nr_pages = MAX_UNCOMP_KERNEL_SIZE / EFI_PAGE_SIZE; + status = efi_call_early(allocate_pages, EFI_ALLOCATE_MAX_ADDRESS, + EFI_BOOT_SERVICES_DATA, nr_pages, &alloc_addr); + if (status == EFI_SUCCESS) { + if (alloc_addr == dram_base) { + *reserve_addr = alloc_addr; + *reserve_size = MAX_UNCOMP_KERNEL_SIZE; + return EFI_SUCCESS; + } + /* + * If we end up here, the allocation succeeded but starts below + * dram_base. This can only occur if the real base of DRAM is + * not a multiple of 128 MB, in which case dram_base will have + * been rounded up. Since this implies that a part of the region + * was already occupied, we need to fall through to the code + * below to ensure that the existing allocations don't conflict. + * For this reason, we use EFI_BOOT_SERVICES_DATA above and not + * EFI_LOADER_DATA, which we wouldn't able to distinguish from + * allocations that we want to disallow. + */ + } + + /* + * If the allocation above failed, we may still be able to proceed: + * if the only allocations in the region are of types that will be + * released to the OS after ExitBootServices(), the decompressor can + * safely overwrite them. + */ + status = efi_get_memory_map(sys_table_arg, &map); + if (status != EFI_SUCCESS) { + pr_efi_err(sys_table_arg, + "reserve_kernel_base(): Unable to retrieve memory map.\n"); + return status; + } + + for (l = 0; l < map_size; l += desc_size) { + efi_memory_desc_t *desc; + u64 start, end; + + desc = (void *)memory_map + l; + start = desc->phys_addr; + end = start + desc->num_pages * EFI_PAGE_SIZE; + + /* Skip if entry does not intersect with region */ + if (start >= dram_base + MAX_UNCOMP_KERNEL_SIZE || + end <= dram_base) + continue; + + switch (desc->type) { + case EFI_BOOT_SERVICES_CODE: + case EFI_BOOT_SERVICES_DATA: + /* Ignore types that are released to the OS anyway */ + continue; + + case EFI_CONVENTIONAL_MEMORY: + /* + * Reserve the intersection between this entry and the + * region. + */ + start = max(start, (u64)dram_base); + end = min(end, (u64)dram_base + MAX_UNCOMP_KERNEL_SIZE); + + status = efi_call_early(allocate_pages, + EFI_ALLOCATE_ADDRESS, + EFI_LOADER_DATA, + (end - start) / EFI_PAGE_SIZE, + &start); + if (status != EFI_SUCCESS) { + pr_efi_err(sys_table_arg, + "reserve_kernel_base(): alloc failed.\n"); + goto out; + } + break; + + case EFI_LOADER_CODE: + case EFI_LOADER_DATA: + /* + * These regions may be released and reallocated for + * another purpose (including EFI_RUNTIME_SERVICE_DATA) + * at any time during the execution of the OS loader, + * so we cannot consider them as safe. + */ + default: + /* + * Treat any other allocation in the region as unsafe */ + status = EFI_OUT_OF_RESOURCES; + goto out; + } + } + + status = EFI_SUCCESS; +out: + efi_call_early(free_pool, memory_map); + return status; +} + +efi_status_t handle_kernel_image(efi_system_table_t *sys_table, + unsigned long *image_addr, + unsigned long *image_size, + unsigned long *reserve_addr, + unsigned long *reserve_size, + unsigned long dram_base, + efi_loaded_image_t *image) +{ + efi_status_t status; + + /* + * Verify that the DRAM base address is compatible with the ARM + * boot protocol, which determines the base of DRAM by masking + * off the low 27 bits of the address at which the zImage is + * loaded. These assumptions are made by the decompressor, + * before any memory map is available. + */ + dram_base = round_up(dram_base, SZ_128M); + + status = reserve_kernel_base(sys_table, dram_base, reserve_addr, + reserve_size); + if (status != EFI_SUCCESS) { + pr_efi_err(sys_table, "Unable to allocate memory for uncompressed kernel.\n"); + return status; + } + + /* + * Relocate the zImage, so that it appears in the lowest 128 MB + * memory window. + */ + *image_size = image->image_size; + status = efi_relocate_kernel(sys_table, image_addr, *image_size, + *image_size, + dram_base + MAX_UNCOMP_KERNEL_SIZE, 0); + if (status != EFI_SUCCESS) { + pr_efi_err(sys_table, "Failed to relocate kernel.\n"); + efi_free(sys_table, *reserve_size, *reserve_addr); + *reserve_size = 0; + return status; + } + + /* + * Check to see if we were able to allocate memory low enough + * in memory. The kernel determines the base of DRAM from the + * address at which the zImage is loaded. + */ + if (*image_addr + *image_size > dram_base + ZIMAGE_OFFSET_LIMIT) { + pr_efi_err(sys_table, "Failed to relocate kernel, no low memory available.\n"); + efi_free(sys_table, *reserve_size, *reserve_addr); + *reserve_size = 0; + efi_free(sys_table, *image_size, *image_addr); + *image_size = 0; + return EFI_LOAD_ERROR; + } + return EFI_SUCCESS; +} diff --git a/drivers/firmware/efi/libstub/arm64-stub.c b/drivers/firmware/efi/libstub/arm64-stub.c new file mode 100644 index 000000000..1b4d465cc --- /dev/null +++ b/drivers/firmware/efi/libstub/arm64-stub.c @@ -0,0 +1,159 @@ +/* + * Copyright (C) 2013, 2014 Linaro Ltd; <roy.franz@linaro.org> + * + * This file implements the EFI boot stub for the arm64 kernel. + * Adapted from ARM version by Mark Salter <msalter@redhat.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * 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/sysreg.h> + +#include "efistub.h" + +efi_status_t check_platform_features(efi_system_table_t *sys_table_arg) +{ + u64 tg; + + /* UEFI mandates support for 4 KB granularity, no need to check */ + if (IS_ENABLED(CONFIG_ARM64_4K_PAGES)) + return EFI_SUCCESS; + + tg = (read_cpuid(ID_AA64MMFR0_EL1) >> ID_AA64MMFR0_TGRAN_SHIFT) & 0xf; + if (tg != ID_AA64MMFR0_TGRAN_SUPPORTED) { + if (IS_ENABLED(CONFIG_ARM64_64K_PAGES)) + pr_efi_err(sys_table_arg, "This 64 KB granular kernel is not supported by your CPU\n"); + else + pr_efi_err(sys_table_arg, "This 16 KB granular kernel is not supported by your CPU\n"); + return EFI_UNSUPPORTED; + } + return EFI_SUCCESS; +} + +efi_status_t handle_kernel_image(efi_system_table_t *sys_table_arg, + unsigned long *image_addr, + unsigned long *image_size, + unsigned long *reserve_addr, + unsigned long *reserve_size, + unsigned long dram_base, + efi_loaded_image_t *image) +{ + efi_status_t status; + unsigned long kernel_size, kernel_memsize = 0; + void *old_image_addr = (void *)*image_addr; + unsigned long preferred_offset; + u64 phys_seed = 0; + + if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) { + if (!nokaslr()) { + status = efi_get_random_bytes(sys_table_arg, + sizeof(phys_seed), + (u8 *)&phys_seed); + if (status == EFI_NOT_FOUND) { + pr_efi(sys_table_arg, "EFI_RNG_PROTOCOL unavailable, no randomness supplied\n"); + } else if (status != EFI_SUCCESS) { + pr_efi_err(sys_table_arg, "efi_get_random_bytes() failed\n"); + return status; + } + } else { + pr_efi(sys_table_arg, "KASLR disabled on kernel command line\n"); + } + } + + /* + * The preferred offset of the kernel Image is TEXT_OFFSET bytes beyond + * a 2 MB aligned base, which itself may be lower than dram_base, as + * long as the resulting offset equals or exceeds it. + */ + preferred_offset = round_down(dram_base, MIN_KIMG_ALIGN) + TEXT_OFFSET; + if (preferred_offset < dram_base) + preferred_offset += MIN_KIMG_ALIGN; + + kernel_size = _edata - _text; + kernel_memsize = kernel_size + (_end - _edata); + + if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && phys_seed != 0) { + /* + * If CONFIG_DEBUG_ALIGN_RODATA is not set, produce a + * displacement in the interval [0, MIN_KIMG_ALIGN) that + * doesn't violate this kernel's de-facto alignment + * constraints. + */ + u32 mask = (MIN_KIMG_ALIGN - 1) & ~(EFI_KIMG_ALIGN - 1); + u32 offset = !IS_ENABLED(CONFIG_DEBUG_ALIGN_RODATA) ? + (phys_seed >> 32) & mask : TEXT_OFFSET; + + /* + * With CONFIG_RANDOMIZE_TEXT_OFFSET=y, TEXT_OFFSET may not + * be a multiple of EFI_KIMG_ALIGN, and we must ensure that + * we preserve the misalignment of 'offset' relative to + * EFI_KIMG_ALIGN so that statically allocated objects whose + * alignment exceeds PAGE_SIZE appear correctly aligned in + * memory. + */ + offset |= TEXT_OFFSET % EFI_KIMG_ALIGN; + + /* + * If KASLR is enabled, and we have some randomness available, + * locate the kernel at a randomized offset in physical memory. + */ + *reserve_size = kernel_memsize + offset; + status = efi_random_alloc(sys_table_arg, *reserve_size, + MIN_KIMG_ALIGN, reserve_addr, + (u32)phys_seed); + + *image_addr = *reserve_addr + offset; + } else { + /* + * Else, try a straight allocation at the preferred offset. + * This will work around the issue where, if dram_base == 0x0, + * efi_low_alloc() refuses to allocate at 0x0 (to prevent the + * address of the allocation to be mistaken for a FAIL return + * value or a NULL pointer). It will also ensure that, on + * platforms where the [dram_base, dram_base + TEXT_OFFSET) + * interval is partially occupied by the firmware (like on APM + * Mustang), we can still place the kernel at the address + * 'dram_base + TEXT_OFFSET'. + */ + if (*image_addr == preferred_offset) + return EFI_SUCCESS; + + *image_addr = *reserve_addr = preferred_offset; + *reserve_size = round_up(kernel_memsize, EFI_ALLOC_ALIGN); + + status = efi_call_early(allocate_pages, EFI_ALLOCATE_ADDRESS, + EFI_LOADER_DATA, + *reserve_size / EFI_PAGE_SIZE, + (efi_physical_addr_t *)reserve_addr); + } + + if (status != EFI_SUCCESS) { + *reserve_size = kernel_memsize + TEXT_OFFSET; + status = efi_low_alloc(sys_table_arg, *reserve_size, + MIN_KIMG_ALIGN, reserve_addr); + + if (status != EFI_SUCCESS) { + pr_efi_err(sys_table_arg, "Failed to relocate kernel\n"); + *reserve_size = 0; + return status; + } + *image_addr = *reserve_addr + TEXT_OFFSET; + } + memcpy((void *)*image_addr, old_image_addr, kernel_size); + + return EFI_SUCCESS; +} diff --git a/drivers/firmware/efi/libstub/efi-stub-helper.c b/drivers/firmware/efi/libstub/efi-stub-helper.c new file mode 100644 index 000000000..442f51c2a --- /dev/null +++ b/drivers/firmware/efi/libstub/efi-stub-helper.c @@ -0,0 +1,931 @@ +/* + * Helper functions used by the EFI stub on multiple + * architectures. This should be #included by the EFI stub + * implementation files. + * + * Copyright 2011 Intel Corporation; author Matt Fleming + * + * 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" + +/* + * Some firmware implementations have problems reading files in one go. + * A read chunk size of 1MB seems to work for most platforms. + * + * Unfortunately, reading files in chunks triggers *other* bugs on some + * platforms, so we provide a way to disable this workaround, which can + * be done by passing "efi=nochunk" on the EFI boot stub command line. + * + * If you experience issues with initrd images being corrupt it's worth + * trying efi=nochunk, but chunking is enabled by default because there + * are far more machines that require the workaround than those that + * break with it enabled. + */ +#define EFI_READ_CHUNK_SIZE (1024 * 1024) + +static unsigned long __chunk_size = EFI_READ_CHUNK_SIZE; + +static int __section(.data) __nokaslr; +static int __section(.data) __quiet; +static int __section(.data) __novamap; + +int __pure nokaslr(void) +{ + return __nokaslr; +} +int __pure is_quiet(void) +{ + return __quiet; +} +int __pure novamap(void) +{ + return __novamap; +} + +#define EFI_MMAP_NR_SLACK_SLOTS 8 + +struct file_info { + efi_file_handle_t *handle; + u64 size; +}; + +void efi_printk(efi_system_table_t *sys_table_arg, char *str) +{ + char *s8; + + for (s8 = str; *s8; s8++) { + efi_char16_t ch[2] = { 0 }; + + ch[0] = *s8; + if (*s8 == '\n') { + efi_char16_t nl[2] = { '\r', 0 }; + efi_char16_printk(sys_table_arg, nl); + } + + efi_char16_printk(sys_table_arg, ch); + } +} + +static inline bool mmap_has_headroom(unsigned long buff_size, + unsigned long map_size, + unsigned long desc_size) +{ + unsigned long slack = buff_size - map_size; + + return slack / desc_size >= EFI_MMAP_NR_SLACK_SLOTS; +} + +efi_status_t efi_get_memory_map(efi_system_table_t *sys_table_arg, + struct efi_boot_memmap *map) +{ + efi_memory_desc_t *m = NULL; + efi_status_t status; + unsigned long key; + u32 desc_version; + + *map->desc_size = sizeof(*m); + *map->map_size = *map->desc_size * 32; + *map->buff_size = *map->map_size; +again: + status = efi_call_early(allocate_pool, EFI_LOADER_DATA, + *map->map_size, (void **)&m); + if (status != EFI_SUCCESS) + goto fail; + + *map->desc_size = 0; + key = 0; + status = efi_call_early(get_memory_map, map->map_size, m, + &key, map->desc_size, &desc_version); + if (status == EFI_BUFFER_TOO_SMALL || + !mmap_has_headroom(*map->buff_size, *map->map_size, + *map->desc_size)) { + efi_call_early(free_pool, m); + /* + * Make sure there is some entries of headroom so that the + * buffer can be reused for a new map after allocations are + * no longer permitted. Its unlikely that the map will grow to + * exceed this headroom once we are ready to trigger + * ExitBootServices() + */ + *map->map_size += *map->desc_size * EFI_MMAP_NR_SLACK_SLOTS; + *map->buff_size = *map->map_size; + goto again; + } + + if (status != EFI_SUCCESS) + efi_call_early(free_pool, m); + + if (map->key_ptr && status == EFI_SUCCESS) + *map->key_ptr = key; + if (map->desc_ver && status == EFI_SUCCESS) + *map->desc_ver = desc_version; + +fail: + *map->map = m; + return status; +} + + +unsigned long get_dram_base(efi_system_table_t *sys_table_arg) +{ + efi_status_t status; + unsigned long map_size, buff_size; + unsigned long membase = EFI_ERROR; + struct efi_memory_map map; + efi_memory_desc_t *md; + struct efi_boot_memmap boot_map; + + boot_map.map = (efi_memory_desc_t **)&map.map; + boot_map.map_size = &map_size; + boot_map.desc_size = &map.desc_size; + boot_map.desc_ver = NULL; + boot_map.key_ptr = NULL; + boot_map.buff_size = &buff_size; + + status = efi_get_memory_map(sys_table_arg, &boot_map); + if (status != EFI_SUCCESS) + return membase; + + map.map_end = map.map + map_size; + + for_each_efi_memory_desc_in_map(&map, md) { + if (md->attribute & EFI_MEMORY_WB) { + if (membase > md->phys_addr) + membase = md->phys_addr; + } + } + + efi_call_early(free_pool, map.map); + + return membase; +} + +/* + * Allocate at the highest possible address that is not above 'max'. + */ +efi_status_t efi_high_alloc(efi_system_table_t *sys_table_arg, + unsigned long size, unsigned long align, + unsigned long *addr, unsigned long max) +{ + unsigned long map_size, desc_size, buff_size; + efi_memory_desc_t *map; + efi_status_t status; + unsigned long nr_pages; + u64 max_addr = 0; + int i; + struct efi_boot_memmap boot_map; + + boot_map.map = ↦ + boot_map.map_size = &map_size; + boot_map.desc_size = &desc_size; + boot_map.desc_ver = NULL; + boot_map.key_ptr = NULL; + boot_map.buff_size = &buff_size; + + status = efi_get_memory_map(sys_table_arg, &boot_map); + if (status != EFI_SUCCESS) + goto fail; + + /* + * Enforce minimum alignment that EFI or Linux requires when + * requesting a specific address. We are doing page-based (or + * larger) allocations, and both the address and size must meet + * alignment constraints. + */ + if (align < EFI_ALLOC_ALIGN) + align = EFI_ALLOC_ALIGN; + + size = round_up(size, EFI_ALLOC_ALIGN); + nr_pages = size / EFI_PAGE_SIZE; +again: + for (i = 0; i < map_size / desc_size; i++) { + efi_memory_desc_t *desc; + unsigned long m = (unsigned long)map; + u64 start, end; + + desc = efi_early_memdesc_ptr(m, desc_size, i); + if (desc->type != EFI_CONVENTIONAL_MEMORY) + continue; + + if (desc->num_pages < nr_pages) + continue; + + start = desc->phys_addr; + end = start + desc->num_pages * EFI_PAGE_SIZE; + + if (end > max) + end = max; + + if ((start + size) > end) + continue; + + if (round_down(end - size, align) < start) + continue; + + start = round_down(end - size, align); + + /* + * Don't allocate at 0x0. It will confuse code that + * checks pointers against NULL. + */ + if (start == 0x0) + continue; + + if (start > max_addr) + max_addr = start; + } + + if (!max_addr) + status = EFI_NOT_FOUND; + else { + status = efi_call_early(allocate_pages, + EFI_ALLOCATE_ADDRESS, EFI_LOADER_DATA, + nr_pages, &max_addr); + if (status != EFI_SUCCESS) { + max = max_addr; + max_addr = 0; + goto again; + } + + *addr = max_addr; + } + + efi_call_early(free_pool, map); +fail: + return status; +} + +/* + * Allocate at the lowest possible address. + */ +efi_status_t efi_low_alloc(efi_system_table_t *sys_table_arg, + unsigned long size, unsigned long align, + unsigned long *addr) +{ + unsigned long map_size, desc_size, buff_size; + efi_memory_desc_t *map; + efi_status_t status; + unsigned long nr_pages; + int i; + struct efi_boot_memmap boot_map; + + boot_map.map = ↦ + boot_map.map_size = &map_size; + boot_map.desc_size = &desc_size; + boot_map.desc_ver = NULL; + boot_map.key_ptr = NULL; + boot_map.buff_size = &buff_size; + + status = efi_get_memory_map(sys_table_arg, &boot_map); + if (status != EFI_SUCCESS) + goto fail; + + /* + * Enforce minimum alignment that EFI or Linux requires when + * requesting a specific address. We are doing page-based (or + * larger) allocations, and both the address and size must meet + * alignment constraints. + */ + if (align < EFI_ALLOC_ALIGN) + align = EFI_ALLOC_ALIGN; + + size = round_up(size, EFI_ALLOC_ALIGN); + nr_pages = size / EFI_PAGE_SIZE; + for (i = 0; i < map_size / desc_size; i++) { + efi_memory_desc_t *desc; + unsigned long m = (unsigned long)map; + u64 start, end; + + desc = efi_early_memdesc_ptr(m, desc_size, i); + + if (desc->type != EFI_CONVENTIONAL_MEMORY) + continue; + + if (desc->num_pages < nr_pages) + continue; + + start = desc->phys_addr; + end = start + desc->num_pages * EFI_PAGE_SIZE; + + /* + * Don't allocate at 0x0. It will confuse code that + * checks pointers against NULL. Skip the first 8 + * bytes so we start at a nice even number. + */ + if (start == 0x0) + start += 8; + + start = round_up(start, align); + if ((start + size) > end) + continue; + + status = efi_call_early(allocate_pages, + EFI_ALLOCATE_ADDRESS, EFI_LOADER_DATA, + nr_pages, &start); + if (status == EFI_SUCCESS) { + *addr = start; + break; + } + } + + if (i == map_size / desc_size) + status = EFI_NOT_FOUND; + + efi_call_early(free_pool, map); +fail: + return status; +} + +void efi_free(efi_system_table_t *sys_table_arg, unsigned long size, + unsigned long addr) +{ + unsigned long nr_pages; + + if (!size) + return; + + nr_pages = round_up(size, EFI_ALLOC_ALIGN) / EFI_PAGE_SIZE; + efi_call_early(free_pages, addr, nr_pages); +} + +static efi_status_t efi_file_size(efi_system_table_t *sys_table_arg, void *__fh, + efi_char16_t *filename_16, void **handle, + u64 *file_sz) +{ + efi_file_handle_t *h, *fh = __fh; + efi_file_info_t *info; + efi_status_t status; + efi_guid_t info_guid = EFI_FILE_INFO_ID; + unsigned long info_sz; + + status = efi_call_proto(efi_file_handle, open, fh, &h, filename_16, + EFI_FILE_MODE_READ, (u64)0); + if (status != EFI_SUCCESS) { + efi_printk(sys_table_arg, "Failed to open file: "); + efi_char16_printk(sys_table_arg, filename_16); + efi_printk(sys_table_arg, "\n"); + return status; + } + + *handle = h; + + info_sz = 0; + status = efi_call_proto(efi_file_handle, get_info, h, &info_guid, + &info_sz, NULL); + if (status != EFI_BUFFER_TOO_SMALL) { + efi_printk(sys_table_arg, "Failed to get file info size\n"); + return status; + } + +grow: + status = efi_call_early(allocate_pool, EFI_LOADER_DATA, + info_sz, (void **)&info); + if (status != EFI_SUCCESS) { + efi_printk(sys_table_arg, "Failed to alloc mem for file info\n"); + return status; + } + + status = efi_call_proto(efi_file_handle, get_info, h, &info_guid, + &info_sz, info); + if (status == EFI_BUFFER_TOO_SMALL) { + efi_call_early(free_pool, info); + goto grow; + } + + *file_sz = info->file_size; + efi_call_early(free_pool, info); + + if (status != EFI_SUCCESS) + efi_printk(sys_table_arg, "Failed to get initrd info\n"); + + return status; +} + +static efi_status_t efi_file_read(void *handle, unsigned long *size, void *addr) +{ + return efi_call_proto(efi_file_handle, read, handle, size, addr); +} + +static efi_status_t efi_file_close(void *handle) +{ + return efi_call_proto(efi_file_handle, close, handle); +} + +static efi_status_t efi_open_volume(efi_system_table_t *sys_table_arg, + efi_loaded_image_t *image, + efi_file_handle_t **__fh) +{ + efi_file_io_interface_t *io; + efi_file_handle_t *fh; + efi_guid_t fs_proto = EFI_FILE_SYSTEM_GUID; + efi_status_t status; + void *handle = (void *)(unsigned long)efi_table_attr(efi_loaded_image, + device_handle, + image); + + status = efi_call_early(handle_protocol, handle, + &fs_proto, (void **)&io); + if (status != EFI_SUCCESS) { + efi_printk(sys_table_arg, "Failed to handle fs_proto\n"); + return status; + } + + status = efi_call_proto(efi_file_io_interface, open_volume, io, &fh); + if (status != EFI_SUCCESS) + efi_printk(sys_table_arg, "Failed to open volume\n"); + else + *__fh = fh; + + return status; +} + +/* + * Parse the ASCII string 'cmdline' for EFI options, denoted by the efi= + * option, e.g. efi=nochunk. + * + * It should be noted that efi= is parsed in two very different + * environments, first in the early boot environment of the EFI boot + * stub, and subsequently during the kernel boot. + */ +efi_status_t efi_parse_options(char const *cmdline) +{ + char *str; + + str = strstr(cmdline, "nokaslr"); + if (str == cmdline || (str && str > cmdline && *(str - 1) == ' ')) + __nokaslr = 1; + + str = strstr(cmdline, "quiet"); + if (str == cmdline || (str && str > cmdline && *(str - 1) == ' ')) + __quiet = 1; + + /* + * If no EFI parameters were specified on the cmdline we've got + * nothing to do. + */ + str = strstr(cmdline, "efi="); + if (!str) + return EFI_SUCCESS; + + /* Skip ahead to first argument */ + str += strlen("efi="); + + /* + * Remember, because efi= is also used by the kernel we need to + * skip over arguments we don't understand. + */ + while (*str && *str != ' ') { + if (!strncmp(str, "nochunk", 7)) { + str += strlen("nochunk"); + __chunk_size = -1UL; + } + + if (!strncmp(str, "novamap", 7)) { + str += strlen("novamap"); + __novamap = 1; + } + + /* Group words together, delimited by "," */ + while (*str && *str != ' ' && *str != ',') + str++; + + if (*str == ',') + str++; + } + + return EFI_SUCCESS; +} + +/* + * Check the cmdline for a LILO-style file= arguments. + * + * We only support loading a file from the same filesystem as + * the kernel image. + */ +efi_status_t handle_cmdline_files(efi_system_table_t *sys_table_arg, + efi_loaded_image_t *image, + char *cmd_line, char *option_string, + unsigned long max_addr, + unsigned long *load_addr, + unsigned long *load_size) +{ + struct file_info *files; + unsigned long file_addr; + u64 file_size_total; + efi_file_handle_t *fh = NULL; + efi_status_t status; + int nr_files; + char *str; + int i, j, k; + + file_addr = 0; + file_size_total = 0; + + str = cmd_line; + + j = 0; /* See close_handles */ + + if (!load_addr || !load_size) + return EFI_INVALID_PARAMETER; + + *load_addr = 0; + *load_size = 0; + + if (!str || !*str) + return EFI_SUCCESS; + + for (nr_files = 0; *str; nr_files++) { + str = strstr(str, option_string); + if (!str) + break; + + str += strlen(option_string); + + /* Skip any leading slashes */ + while (*str == '/' || *str == '\\') + str++; + + while (*str && *str != ' ' && *str != '\n') + str++; + } + + if (!nr_files) + return EFI_SUCCESS; + + status = efi_call_early(allocate_pool, EFI_LOADER_DATA, + nr_files * sizeof(*files), (void **)&files); + if (status != EFI_SUCCESS) { + pr_efi_err(sys_table_arg, "Failed to alloc mem for file handle list\n"); + goto fail; + } + + str = cmd_line; + for (i = 0; i < nr_files; i++) { + struct file_info *file; + efi_char16_t filename_16[256]; + efi_char16_t *p; + + str = strstr(str, option_string); + if (!str) + break; + + str += strlen(option_string); + + file = &files[i]; + p = filename_16; + + /* Skip any leading slashes */ + while (*str == '/' || *str == '\\') + str++; + + while (*str && *str != ' ' && *str != '\n') { + if ((u8 *)p >= (u8 *)filename_16 + sizeof(filename_16)) + break; + + if (*str == '/') { + *p++ = '\\'; + str++; + } else { + *p++ = *str++; + } + } + + *p = '\0'; + + /* Only open the volume once. */ + if (!i) { + status = efi_open_volume(sys_table_arg, image, &fh); + if (status != EFI_SUCCESS) + goto free_files; + } + + status = efi_file_size(sys_table_arg, fh, filename_16, + (void **)&file->handle, &file->size); + if (status != EFI_SUCCESS) + goto close_handles; + + file_size_total += file->size; + } + + if (file_size_total) { + unsigned long addr; + + /* + * Multiple files need to be at consecutive addresses in memory, + * so allocate enough memory for all the files. This is used + * for loading multiple files. + */ + status = efi_high_alloc(sys_table_arg, file_size_total, 0x1000, + &file_addr, max_addr); + if (status != EFI_SUCCESS) { + pr_efi_err(sys_table_arg, "Failed to alloc highmem for files\n"); + goto close_handles; + } + + /* We've run out of free low memory. */ + if (file_addr > max_addr) { + pr_efi_err(sys_table_arg, "We've run out of free low memory\n"); + status = EFI_INVALID_PARAMETER; + goto free_file_total; + } + + addr = file_addr; + for (j = 0; j < nr_files; j++) { + unsigned long size; + + size = files[j].size; + while (size) { + unsigned long chunksize; + + if (IS_ENABLED(CONFIG_X86) && size > __chunk_size) + chunksize = __chunk_size; + else + chunksize = size; + + status = efi_file_read(files[j].handle, + &chunksize, + (void *)addr); + if (status != EFI_SUCCESS) { + pr_efi_err(sys_table_arg, "Failed to read file\n"); + goto free_file_total; + } + addr += chunksize; + size -= chunksize; + } + + efi_file_close(files[j].handle); + } + + } + + efi_call_early(free_pool, files); + + *load_addr = file_addr; + *load_size = file_size_total; + + return status; + +free_file_total: + efi_free(sys_table_arg, file_size_total, file_addr); + +close_handles: + for (k = j; k < i; k++) + efi_file_close(files[k].handle); +free_files: + efi_call_early(free_pool, files); +fail: + *load_addr = 0; + *load_size = 0; + + return status; +} +/* + * Relocate a kernel image, either compressed or uncompressed. + * In the ARM64 case, all kernel images are currently + * uncompressed, and as such when we relocate it we need to + * allocate additional space for the BSS segment. Any low + * memory that this function should avoid needs to be + * unavailable in the EFI memory map, as if the preferred + * address is not available the lowest available address will + * be used. + */ +efi_status_t efi_relocate_kernel(efi_system_table_t *sys_table_arg, + unsigned long *image_addr, + unsigned long image_size, + unsigned long alloc_size, + unsigned long preferred_addr, + unsigned long alignment) +{ + unsigned long cur_image_addr; + unsigned long new_addr = 0; + efi_status_t status; + unsigned long nr_pages; + efi_physical_addr_t efi_addr = preferred_addr; + + if (!image_addr || !image_size || !alloc_size) + return EFI_INVALID_PARAMETER; + if (alloc_size < image_size) + return EFI_INVALID_PARAMETER; + + cur_image_addr = *image_addr; + + /* + * The EFI firmware loader could have placed the kernel image + * anywhere in memory, but the kernel has restrictions on the + * max physical address it can run at. Some architectures + * also have a prefered address, so first try to relocate + * to the preferred address. If that fails, allocate as low + * as possible while respecting the required alignment. + */ + nr_pages = round_up(alloc_size, EFI_ALLOC_ALIGN) / EFI_PAGE_SIZE; + status = efi_call_early(allocate_pages, + EFI_ALLOCATE_ADDRESS, EFI_LOADER_DATA, + nr_pages, &efi_addr); + new_addr = efi_addr; + /* + * If preferred address allocation failed allocate as low as + * possible. + */ + if (status != EFI_SUCCESS) { + status = efi_low_alloc(sys_table_arg, alloc_size, alignment, + &new_addr); + } + if (status != EFI_SUCCESS) { + pr_efi_err(sys_table_arg, "Failed to allocate usable memory for kernel.\n"); + return status; + } + + /* + * We know source/dest won't overlap since both memory ranges + * have been allocated by UEFI, so we can safely use memcpy. + */ + memcpy((void *)new_addr, (void *)cur_image_addr, image_size); + + /* Return the new address of the relocated image. */ + *image_addr = new_addr; + + return status; +} + +/* + * Get the number of UTF-8 bytes corresponding to an UTF-16 character. + * This overestimates for surrogates, but that is okay. + */ +static int efi_utf8_bytes(u16 c) +{ + return 1 + (c >= 0x80) + (c >= 0x800); +} + +/* + * Convert an UTF-16 string, not necessarily null terminated, to UTF-8. + */ +static u8 *efi_utf16_to_utf8(u8 *dst, const u16 *src, int n) +{ + unsigned int c; + + while (n--) { + c = *src++; + if (n && c >= 0xd800 && c <= 0xdbff && + *src >= 0xdc00 && *src <= 0xdfff) { + c = 0x10000 + ((c & 0x3ff) << 10) + (*src & 0x3ff); + src++; + n--; + } + if (c >= 0xd800 && c <= 0xdfff) + c = 0xfffd; /* Unmatched surrogate */ + if (c < 0x80) { + *dst++ = c; + continue; + } + if (c < 0x800) { + *dst++ = 0xc0 + (c >> 6); + goto t1; + } + if (c < 0x10000) { + *dst++ = 0xe0 + (c >> 12); + goto t2; + } + *dst++ = 0xf0 + (c >> 18); + *dst++ = 0x80 + ((c >> 12) & 0x3f); + t2: + *dst++ = 0x80 + ((c >> 6) & 0x3f); + t1: + *dst++ = 0x80 + (c & 0x3f); + } + + return dst; +} + +#ifndef MAX_CMDLINE_ADDRESS +#define MAX_CMDLINE_ADDRESS ULONG_MAX +#endif + +/* + * Convert the unicode UEFI command line to ASCII to pass to kernel. + * Size of memory allocated return in *cmd_line_len. + * Returns NULL on error. + */ +char *efi_convert_cmdline(efi_system_table_t *sys_table_arg, + efi_loaded_image_t *image, + int *cmd_line_len) +{ + const u16 *s2; + u8 *s1 = NULL; + unsigned long cmdline_addr = 0; + int load_options_chars = image->load_options_size / 2; /* UTF-16 */ + const u16 *options = image->load_options; + int options_bytes = 0; /* UTF-8 bytes */ + int options_chars = 0; /* UTF-16 chars */ + efi_status_t status; + u16 zero = 0; + + if (options) { + s2 = options; + while (*s2 && *s2 != '\n' + && options_chars < load_options_chars) { + options_bytes += efi_utf8_bytes(*s2++); + options_chars++; + } + } + + if (!options_chars) { + /* No command line options, so return empty string*/ + options = &zero; + } + + options_bytes++; /* NUL termination */ + + status = efi_high_alloc(sys_table_arg, options_bytes, 0, + &cmdline_addr, MAX_CMDLINE_ADDRESS); + if (status != EFI_SUCCESS) + return NULL; + + s1 = (u8 *)cmdline_addr; + s2 = (const u16 *)options; + + s1 = efi_utf16_to_utf8(s1, s2, options_chars); + *s1 = '\0'; + + *cmd_line_len = options_bytes; + return (char *)cmdline_addr; +} + +/* + * Handle calling ExitBootServices according to the requirements set out by the + * spec. Obtains the current memory map, and returns that info after calling + * ExitBootServices. The client must specify a function to perform any + * processing of the memory map data prior to ExitBootServices. A client + * specific structure may be passed to the function via priv. The client + * function may be called multiple times. + */ +efi_status_t efi_exit_boot_services(efi_system_table_t *sys_table_arg, + void *handle, + struct efi_boot_memmap *map, + void *priv, + efi_exit_boot_map_processing priv_func) +{ + efi_status_t status; + + status = efi_get_memory_map(sys_table_arg, map); + + if (status != EFI_SUCCESS) + goto fail; + + status = priv_func(sys_table_arg, map, priv); + if (status != EFI_SUCCESS) + goto free_map; + + status = efi_call_early(exit_boot_services, handle, *map->key_ptr); + + if (status == EFI_INVALID_PARAMETER) { + /* + * The memory map changed between efi_get_memory_map() and + * exit_boot_services(). Per the UEFI Spec v2.6, Section 6.4: + * EFI_BOOT_SERVICES.ExitBootServices we need to get the + * updated map, and try again. The spec implies one retry + * should be sufficent, which is confirmed against the EDK2 + * implementation. Per the spec, we can only invoke + * get_memory_map() and exit_boot_services() - we cannot alloc + * so efi_get_memory_map() cannot be used, and we must reuse + * the buffer. For all practical purposes, the headroom in the + * buffer should account for any changes in the map so the call + * to get_memory_map() is expected to succeed here. + */ + *map->map_size = *map->buff_size; + status = efi_call_early(get_memory_map, + map->map_size, + *map->map, + map->key_ptr, + map->desc_size, + map->desc_ver); + + /* exit_boot_services() was called, thus cannot free */ + if (status != EFI_SUCCESS) + goto fail; + + status = priv_func(sys_table_arg, map, priv); + /* exit_boot_services() was called, thus cannot free */ + if (status != EFI_SUCCESS) + goto fail; + + status = efi_call_early(exit_boot_services, handle, *map->key_ptr); + } + + /* exit_boot_services() was called, thus cannot free */ + if (status != EFI_SUCCESS) + goto fail; + + return EFI_SUCCESS; + +free_map: + efi_call_early(free_pool, *map->map); +fail: + return status; +} diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h new file mode 100644 index 000000000..337b52c47 --- /dev/null +++ b/drivers/firmware/efi/libstub/efistub.h @@ -0,0 +1,68 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef _DRIVERS_FIRMWARE_EFI_EFISTUB_H +#define _DRIVERS_FIRMWARE_EFI_EFISTUB_H + +/* error code which can't be mistaken for valid address */ +#define EFI_ERROR (~0UL) + +/* + * __init annotations should not be used in the EFI stub, since the code is + * either included in the decompressor (x86, ARM) where they have no effect, + * or the whole stub is __init annotated at the section level (arm64), by + * renaming the sections, in which case the __init annotation will be + * redundant, and will result in section names like .init.init.text, and our + * linker script does not expect that. + */ +#undef __init + +/* + * Allow the platform to override the allocation granularity: this allows + * systems that have the capability to run with a larger page size to deal + * with the allocations for initrd and fdt more efficiently. + */ +#ifndef EFI_ALLOC_ALIGN +#define EFI_ALLOC_ALIGN EFI_PAGE_SIZE +#endif + +extern int __pure nokaslr(void); +extern int __pure is_quiet(void); +extern int __pure novamap(void); + +#define pr_efi(sys_table, msg) do { \ + if (!is_quiet()) efi_printk(sys_table, "EFI stub: "msg); \ +} while (0) + +#define pr_efi_err(sys_table, msg) efi_printk(sys_table, "EFI stub: ERROR: "msg) + +void efi_char16_printk(efi_system_table_t *, efi_char16_t *); + +unsigned long get_dram_base(efi_system_table_t *sys_table_arg); + +efi_status_t allocate_new_fdt_and_exit_boot(efi_system_table_t *sys_table, + void *handle, + unsigned long *new_fdt_addr, + unsigned long max_addr, + u64 initrd_addr, u64 initrd_size, + char *cmdline_ptr, + unsigned long fdt_addr, + unsigned long fdt_size); + +void *get_fdt(efi_system_table_t *sys_table, unsigned long *fdt_size); + +void efi_get_virtmap(efi_memory_desc_t *memory_map, unsigned long map_size, + unsigned long desc_size, efi_memory_desc_t *runtime_map, + int *count); + +efi_status_t efi_get_random_bytes(efi_system_table_t *sys_table, + unsigned long size, u8 *out); + +efi_status_t efi_random_alloc(efi_system_table_t *sys_table_arg, + unsigned long size, unsigned long align, + unsigned long *addr, unsigned long random_seed); + +efi_status_t check_platform_features(efi_system_table_t *sys_table_arg); + +efi_status_t efi_random_get_seed(efi_system_table_t *sys_table_arg); + +#endif diff --git a/drivers/firmware/efi/libstub/fdt.c b/drivers/firmware/efi/libstub/fdt.c new file mode 100644 index 000000000..dba296a44 --- /dev/null +++ b/drivers/firmware/efi/libstub/fdt.c @@ -0,0 +1,394 @@ +/* + * FDT related Helper functions used by the EFI stub on multiple + * architectures. This should be #included by the EFI stub + * implementation files. + * + * Copyright 2013 Linaro Limited; author Roy Franz + * + * 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 <linux/libfdt.h> +#include <asm/efi.h> + +#include "efistub.h" + +#define EFI_DT_ADDR_CELLS_DEFAULT 2 +#define EFI_DT_SIZE_CELLS_DEFAULT 2 + +static void fdt_update_cell_size(efi_system_table_t *sys_table, void *fdt) +{ + int offset; + + offset = fdt_path_offset(fdt, "/"); + /* Set the #address-cells and #size-cells values for an empty tree */ + + fdt_setprop_u32(fdt, offset, "#address-cells", + EFI_DT_ADDR_CELLS_DEFAULT); + + fdt_setprop_u32(fdt, offset, "#size-cells", EFI_DT_SIZE_CELLS_DEFAULT); +} + +static efi_status_t update_fdt(efi_system_table_t *sys_table, void *orig_fdt, + unsigned long orig_fdt_size, + void *fdt, int new_fdt_size, char *cmdline_ptr, + u64 initrd_addr, u64 initrd_size) +{ + int node, num_rsv; + int status; + u32 fdt_val32; + u64 fdt_val64; + + /* Do some checks on provided FDT, if it exists*/ + if (orig_fdt) { + if (fdt_check_header(orig_fdt)) { + pr_efi_err(sys_table, "Device Tree header not valid!\n"); + return EFI_LOAD_ERROR; + } + /* + * We don't get the size of the FDT if we get if from a + * configuration table. + */ + if (orig_fdt_size && fdt_totalsize(orig_fdt) > orig_fdt_size) { + pr_efi_err(sys_table, "Truncated device tree! foo!\n"); + return EFI_LOAD_ERROR; + } + } + + if (orig_fdt) { + status = fdt_open_into(orig_fdt, fdt, new_fdt_size); + } else { + status = fdt_create_empty_tree(fdt, new_fdt_size); + if (status == 0) { + /* + * Any failure from the following function is non + * critical + */ + fdt_update_cell_size(sys_table, fdt); + } + } + + if (status != 0) + goto fdt_set_fail; + + /* + * Delete all memory reserve map entries. When booting via UEFI, + * kernel will use the UEFI memory map to find reserved regions. + */ + num_rsv = fdt_num_mem_rsv(fdt); + while (num_rsv-- > 0) + fdt_del_mem_rsv(fdt, num_rsv); + + node = fdt_subnode_offset(fdt, 0, "chosen"); + if (node < 0) { + node = fdt_add_subnode(fdt, 0, "chosen"); + if (node < 0) { + status = node; /* node is error code when negative */ + goto fdt_set_fail; + } + } + + if ((cmdline_ptr != NULL) && (strlen(cmdline_ptr) > 0)) { + status = fdt_setprop(fdt, node, "bootargs", cmdline_ptr, + strlen(cmdline_ptr) + 1); + if (status) + goto fdt_set_fail; + } + + /* Set initrd address/end in device tree, if present */ + if (initrd_size != 0) { + u64 initrd_image_end; + u64 initrd_image_start = cpu_to_fdt64(initrd_addr); + + status = fdt_setprop(fdt, node, "linux,initrd-start", + &initrd_image_start, sizeof(u64)); + if (status) + goto fdt_set_fail; + initrd_image_end = cpu_to_fdt64(initrd_addr + initrd_size); + status = fdt_setprop(fdt, node, "linux,initrd-end", + &initrd_image_end, sizeof(u64)); + if (status) + goto fdt_set_fail; + } + + /* Add FDT entries for EFI runtime services in chosen node. */ + node = fdt_subnode_offset(fdt, 0, "chosen"); + fdt_val64 = cpu_to_fdt64((u64)(unsigned long)sys_table); + status = fdt_setprop(fdt, node, "linux,uefi-system-table", + &fdt_val64, sizeof(fdt_val64)); + if (status) + goto fdt_set_fail; + + fdt_val64 = U64_MAX; /* placeholder */ + status = fdt_setprop(fdt, node, "linux,uefi-mmap-start", + &fdt_val64, sizeof(fdt_val64)); + if (status) + goto fdt_set_fail; + + fdt_val32 = U32_MAX; /* placeholder */ + status = fdt_setprop(fdt, node, "linux,uefi-mmap-size", + &fdt_val32, sizeof(fdt_val32)); + if (status) + goto fdt_set_fail; + + status = fdt_setprop(fdt, node, "linux,uefi-mmap-desc-size", + &fdt_val32, sizeof(fdt_val32)); + if (status) + goto fdt_set_fail; + + status = fdt_setprop(fdt, node, "linux,uefi-mmap-desc-ver", + &fdt_val32, sizeof(fdt_val32)); + if (status) + goto fdt_set_fail; + + if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) { + efi_status_t efi_status; + + efi_status = efi_get_random_bytes(sys_table, sizeof(fdt_val64), + (u8 *)&fdt_val64); + if (efi_status == EFI_SUCCESS) { + status = fdt_setprop(fdt, node, "kaslr-seed", + &fdt_val64, sizeof(fdt_val64)); + if (status) + goto fdt_set_fail; + } else if (efi_status != EFI_NOT_FOUND) { + return efi_status; + } + } + + /* shrink the FDT back to its minimum size */ + fdt_pack(fdt); + + return EFI_SUCCESS; + +fdt_set_fail: + if (status == -FDT_ERR_NOSPACE) + return EFI_BUFFER_TOO_SMALL; + + return EFI_LOAD_ERROR; +} + +static efi_status_t update_fdt_memmap(void *fdt, struct efi_boot_memmap *map) +{ + int node = fdt_path_offset(fdt, "/chosen"); + u64 fdt_val64; + u32 fdt_val32; + int err; + + if (node < 0) + return EFI_LOAD_ERROR; + + fdt_val64 = cpu_to_fdt64((unsigned long)*map->map); + err = fdt_setprop_inplace(fdt, node, "linux,uefi-mmap-start", + &fdt_val64, sizeof(fdt_val64)); + if (err) + return EFI_LOAD_ERROR; + + fdt_val32 = cpu_to_fdt32(*map->map_size); + err = fdt_setprop_inplace(fdt, node, "linux,uefi-mmap-size", + &fdt_val32, sizeof(fdt_val32)); + if (err) + return EFI_LOAD_ERROR; + + fdt_val32 = cpu_to_fdt32(*map->desc_size); + err = fdt_setprop_inplace(fdt, node, "linux,uefi-mmap-desc-size", + &fdt_val32, sizeof(fdt_val32)); + if (err) + return EFI_LOAD_ERROR; + + fdt_val32 = cpu_to_fdt32(*map->desc_ver); + err = fdt_setprop_inplace(fdt, node, "linux,uefi-mmap-desc-ver", + &fdt_val32, sizeof(fdt_val32)); + if (err) + return EFI_LOAD_ERROR; + + return EFI_SUCCESS; +} + +#ifndef EFI_FDT_ALIGN +#define EFI_FDT_ALIGN EFI_PAGE_SIZE +#endif + +struct exit_boot_struct { + efi_memory_desc_t *runtime_map; + int *runtime_entry_count; + void *new_fdt_addr; +}; + +static efi_status_t exit_boot_func(efi_system_table_t *sys_table_arg, + struct efi_boot_memmap *map, + void *priv) +{ + struct exit_boot_struct *p = priv; + /* + * Update the memory map with virtual addresses. The function will also + * populate @runtime_map with copies of just the EFI_MEMORY_RUNTIME + * entries so that we can pass it straight to SetVirtualAddressMap() + */ + efi_get_virtmap(*map->map, *map->map_size, *map->desc_size, + p->runtime_map, p->runtime_entry_count); + + return update_fdt_memmap(p->new_fdt_addr, map); +} + +#ifndef MAX_FDT_SIZE +#define MAX_FDT_SIZE SZ_2M +#endif + +/* + * Allocate memory for a new FDT, then add EFI, commandline, and + * initrd related fields to the FDT. This routine increases the + * FDT allocation size until the allocated memory is large + * enough. EFI allocations are in EFI_PAGE_SIZE granules, + * which are fixed at 4K bytes, so in most cases the first + * allocation should succeed. + * EFI boot services are exited at the end of this function. + * There must be no allocations between the get_memory_map() + * call and the exit_boot_services() call, so the exiting of + * boot services is very tightly tied to the creation of the FDT + * with the final memory map in it. + */ + +efi_status_t allocate_new_fdt_and_exit_boot(efi_system_table_t *sys_table, + void *handle, + unsigned long *new_fdt_addr, + unsigned long max_addr, + u64 initrd_addr, u64 initrd_size, + char *cmdline_ptr, + unsigned long fdt_addr, + unsigned long fdt_size) +{ + unsigned long map_size, desc_size, buff_size; + u32 desc_ver; + unsigned long mmap_key; + efi_memory_desc_t *memory_map, *runtime_map; + efi_status_t status; + int runtime_entry_count = 0; + struct efi_boot_memmap map; + struct exit_boot_struct priv; + + map.map = &runtime_map; + map.map_size = &map_size; + map.desc_size = &desc_size; + map.desc_ver = &desc_ver; + map.key_ptr = &mmap_key; + map.buff_size = &buff_size; + + /* + * Get a copy of the current memory map that we will use to prepare + * the input for SetVirtualAddressMap(). We don't have to worry about + * subsequent allocations adding entries, since they could not affect + * the number of EFI_MEMORY_RUNTIME regions. + */ + status = efi_get_memory_map(sys_table, &map); + if (status != EFI_SUCCESS) { + pr_efi_err(sys_table, "Unable to retrieve UEFI memory map.\n"); + return status; + } + + pr_efi(sys_table, + "Exiting boot services and installing virtual address map...\n"); + + map.map = &memory_map; + status = efi_high_alloc(sys_table, MAX_FDT_SIZE, EFI_FDT_ALIGN, + new_fdt_addr, max_addr); + if (status != EFI_SUCCESS) { + pr_efi_err(sys_table, + "Unable to allocate memory for new device tree.\n"); + goto fail; + } + + /* + * Now that we have done our final memory allocation (and free) + * we can get the memory map key needed for exit_boot_services(). + */ + status = efi_get_memory_map(sys_table, &map); + if (status != EFI_SUCCESS) + goto fail_free_new_fdt; + + status = update_fdt(sys_table, (void *)fdt_addr, fdt_size, + (void *)*new_fdt_addr, MAX_FDT_SIZE, cmdline_ptr, + initrd_addr, initrd_size); + + if (status != EFI_SUCCESS) { + pr_efi_err(sys_table, "Unable to construct new device tree.\n"); + goto fail_free_new_fdt; + } + + priv.runtime_map = runtime_map; + priv.runtime_entry_count = &runtime_entry_count; + priv.new_fdt_addr = (void *)*new_fdt_addr; + status = efi_exit_boot_services(sys_table, handle, &map, &priv, + exit_boot_func); + + if (status == EFI_SUCCESS) { + efi_set_virtual_address_map_t *svam; + + if (novamap()) + return EFI_SUCCESS; + + /* Install the new virtual address map */ + svam = sys_table->runtime->set_virtual_address_map; + status = svam(runtime_entry_count * desc_size, desc_size, + desc_ver, runtime_map); + + /* + * We are beyond the point of no return here, so if the call to + * SetVirtualAddressMap() failed, we need to signal that to the + * incoming kernel but proceed normally otherwise. + */ + if (status != EFI_SUCCESS) { + int l; + + /* + * Set the virtual address field of all + * EFI_MEMORY_RUNTIME entries to 0. This will signal + * the incoming kernel that no virtual translation has + * been installed. + */ + for (l = 0; l < map_size; l += desc_size) { + efi_memory_desc_t *p = (void *)memory_map + l; + + if (p->attribute & EFI_MEMORY_RUNTIME) + p->virt_addr = 0; + } + } + return EFI_SUCCESS; + } + + pr_efi_err(sys_table, "Exit boot services failed.\n"); + +fail_free_new_fdt: + efi_free(sys_table, MAX_FDT_SIZE, *new_fdt_addr); + +fail: + sys_table->boottime->free_pool(runtime_map); + return EFI_LOAD_ERROR; +} + +void *get_fdt(efi_system_table_t *sys_table, unsigned long *fdt_size) +{ + efi_guid_t fdt_guid = DEVICE_TREE_GUID; + efi_config_table_t *tables; + void *fdt; + int i; + + tables = (efi_config_table_t *) sys_table->tables; + fdt = NULL; + + for (i = 0; i < sys_table->nr_tables; i++) + if (efi_guidcmp(tables[i].guid, fdt_guid) == 0) { + fdt = (void *) tables[i].table; + if (fdt_check_header(fdt) != 0) { + pr_efi_err(sys_table, "Invalid header detected on UEFI supplied FDT, ignoring ...\n"); + return NULL; + } + *fdt_size = fdt_totalsize(fdt); + break; + } + + return fdt; +} diff --git a/drivers/firmware/efi/libstub/gop.c b/drivers/firmware/efi/libstub/gop.c new file mode 100644 index 000000000..fd8053f95 --- /dev/null +++ b/drivers/firmware/efi/libstub/gop.c @@ -0,0 +1,314 @@ +/* ----------------------------------------------------------------------- + * + * Copyright 2011 Intel Corporation; author Matt Fleming + * + * 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 <linux/screen_info.h> +#include <asm/efi.h> +#include <asm/setup.h> + +static void find_bits(unsigned long mask, u8 *pos, u8 *size) +{ + u8 first, len; + + first = 0; + len = 0; + + if (mask) { + while (!(mask & 0x1)) { + mask = mask >> 1; + first++; + } + + while (mask & 0x1) { + mask = mask >> 1; + len++; + } + } + + *pos = first; + *size = len; +} + +static void +setup_pixel_info(struct screen_info *si, u32 pixels_per_scan_line, + struct efi_pixel_bitmask pixel_info, int pixel_format) +{ + if (pixel_format == PIXEL_RGB_RESERVED_8BIT_PER_COLOR) { + si->lfb_depth = 32; + si->lfb_linelength = pixels_per_scan_line * 4; + si->red_size = 8; + si->red_pos = 0; + si->green_size = 8; + si->green_pos = 8; + si->blue_size = 8; + si->blue_pos = 16; + si->rsvd_size = 8; + si->rsvd_pos = 24; + } else if (pixel_format == PIXEL_BGR_RESERVED_8BIT_PER_COLOR) { + si->lfb_depth = 32; + si->lfb_linelength = pixels_per_scan_line * 4; + si->red_size = 8; + si->red_pos = 16; + si->green_size = 8; + si->green_pos = 8; + si->blue_size = 8; + si->blue_pos = 0; + si->rsvd_size = 8; + si->rsvd_pos = 24; + } else if (pixel_format == PIXEL_BIT_MASK) { + find_bits(pixel_info.red_mask, &si->red_pos, &si->red_size); + find_bits(pixel_info.green_mask, &si->green_pos, + &si->green_size); + find_bits(pixel_info.blue_mask, &si->blue_pos, &si->blue_size); + find_bits(pixel_info.reserved_mask, &si->rsvd_pos, + &si->rsvd_size); + si->lfb_depth = si->red_size + si->green_size + + si->blue_size + si->rsvd_size; + si->lfb_linelength = (pixels_per_scan_line * si->lfb_depth) / 8; + } else { + si->lfb_depth = 4; + si->lfb_linelength = si->lfb_width / 2; + si->red_size = 0; + si->red_pos = 0; + si->green_size = 0; + si->green_pos = 0; + si->blue_size = 0; + si->blue_pos = 0; + si->rsvd_size = 0; + si->rsvd_pos = 0; + } +} + +static efi_status_t +setup_gop32(efi_system_table_t *sys_table_arg, struct screen_info *si, + efi_guid_t *proto, unsigned long size, void **gop_handle) +{ + struct efi_graphics_output_protocol_32 *gop32, *first_gop; + unsigned long nr_gops; + u16 width, height; + u32 pixels_per_scan_line; + u32 ext_lfb_base; + u64 fb_base; + struct efi_pixel_bitmask pixel_info; + int pixel_format; + efi_status_t status; + u32 *handles = (u32 *)(unsigned long)gop_handle; + int i; + + first_gop = NULL; + gop32 = NULL; + + nr_gops = size / sizeof(u32); + for (i = 0; i < nr_gops; i++) { + struct efi_graphics_output_protocol_mode_32 *mode; + struct efi_graphics_output_mode_info *info = NULL; + efi_guid_t conout_proto = EFI_CONSOLE_OUT_DEVICE_GUID; + bool conout_found = false; + void *dummy = NULL; + efi_handle_t h = (efi_handle_t)(unsigned long)handles[i]; + u64 current_fb_base; + + status = efi_call_early(handle_protocol, h, + proto, (void **)&gop32); + if (status != EFI_SUCCESS) + continue; + + status = efi_call_early(handle_protocol, h, + &conout_proto, &dummy); + if (status == EFI_SUCCESS) + conout_found = true; + + mode = (void *)(unsigned long)gop32->mode; + info = (void *)(unsigned long)mode->info; + current_fb_base = mode->frame_buffer_base; + + if ((!first_gop || conout_found) && + info->pixel_format != PIXEL_BLT_ONLY) { + /* + * Systems that use the UEFI Console Splitter may + * provide multiple GOP devices, not all of which are + * backed by real hardware. The workaround is to search + * for a GOP implementing the ConOut protocol, and if + * one isn't found, to just fall back to the first GOP. + */ + width = info->horizontal_resolution; + height = info->vertical_resolution; + pixel_format = info->pixel_format; + pixel_info = info->pixel_information; + pixels_per_scan_line = info->pixels_per_scan_line; + fb_base = current_fb_base; + + /* + * Once we've found a GOP supporting ConOut, + * don't bother looking any further. + */ + first_gop = gop32; + if (conout_found) + break; + } + } + + /* Did we find any GOPs? */ + if (!first_gop) + return EFI_NOT_FOUND; + + /* EFI framebuffer */ + si->orig_video_isVGA = VIDEO_TYPE_EFI; + + si->lfb_width = width; + si->lfb_height = height; + si->lfb_base = fb_base; + + ext_lfb_base = (u64)(unsigned long)fb_base >> 32; + if (ext_lfb_base) { + si->capabilities |= VIDEO_CAPABILITY_64BIT_BASE; + si->ext_lfb_base = ext_lfb_base; + } + + si->pages = 1; + + setup_pixel_info(si, pixels_per_scan_line, pixel_info, pixel_format); + + si->lfb_size = si->lfb_linelength * si->lfb_height; + + si->capabilities |= VIDEO_CAPABILITY_SKIP_QUIRKS; + + return EFI_SUCCESS; +} + +static efi_status_t +setup_gop64(efi_system_table_t *sys_table_arg, struct screen_info *si, + efi_guid_t *proto, unsigned long size, void **gop_handle) +{ + struct efi_graphics_output_protocol_64 *gop64, *first_gop; + unsigned long nr_gops; + u16 width, height; + u32 pixels_per_scan_line; + u32 ext_lfb_base; + u64 fb_base; + struct efi_pixel_bitmask pixel_info; + int pixel_format; + efi_status_t status; + u64 *handles = (u64 *)(unsigned long)gop_handle; + int i; + + first_gop = NULL; + gop64 = NULL; + + nr_gops = size / sizeof(u64); + for (i = 0; i < nr_gops; i++) { + struct efi_graphics_output_protocol_mode_64 *mode; + struct efi_graphics_output_mode_info *info = NULL; + efi_guid_t conout_proto = EFI_CONSOLE_OUT_DEVICE_GUID; + bool conout_found = false; + void *dummy = NULL; + efi_handle_t h = (efi_handle_t)(unsigned long)handles[i]; + u64 current_fb_base; + + status = efi_call_early(handle_protocol, h, + proto, (void **)&gop64); + if (status != EFI_SUCCESS) + continue; + + status = efi_call_early(handle_protocol, h, + &conout_proto, &dummy); + if (status == EFI_SUCCESS) + conout_found = true; + + mode = (void *)(unsigned long)gop64->mode; + info = (void *)(unsigned long)mode->info; + current_fb_base = mode->frame_buffer_base; + + if ((!first_gop || conout_found) && + info->pixel_format != PIXEL_BLT_ONLY) { + /* + * Systems that use the UEFI Console Splitter may + * provide multiple GOP devices, not all of which are + * backed by real hardware. The workaround is to search + * for a GOP implementing the ConOut protocol, and if + * one isn't found, to just fall back to the first GOP. + */ + width = info->horizontal_resolution; + height = info->vertical_resolution; + pixel_format = info->pixel_format; + pixel_info = info->pixel_information; + pixels_per_scan_line = info->pixels_per_scan_line; + fb_base = current_fb_base; + + /* + * Once we've found a GOP supporting ConOut, + * don't bother looking any further. + */ + first_gop = gop64; + if (conout_found) + break; + } + } + + /* Did we find any GOPs? */ + if (!first_gop) + return EFI_NOT_FOUND; + + /* EFI framebuffer */ + si->orig_video_isVGA = VIDEO_TYPE_EFI; + + si->lfb_width = width; + si->lfb_height = height; + si->lfb_base = fb_base; + + ext_lfb_base = (u64)(unsigned long)fb_base >> 32; + if (ext_lfb_base) { + si->capabilities |= VIDEO_CAPABILITY_64BIT_BASE; + si->ext_lfb_base = ext_lfb_base; + } + + si->pages = 1; + + setup_pixel_info(si, pixels_per_scan_line, pixel_info, pixel_format); + + si->lfb_size = si->lfb_linelength * si->lfb_height; + + si->capabilities |= VIDEO_CAPABILITY_SKIP_QUIRKS; + + return EFI_SUCCESS; +} + +/* + * See if we have Graphics Output Protocol + */ +efi_status_t efi_setup_gop(efi_system_table_t *sys_table_arg, + struct screen_info *si, efi_guid_t *proto, + unsigned long size) +{ + efi_status_t status; + void **gop_handle = NULL; + + status = efi_call_early(allocate_pool, EFI_LOADER_DATA, + size, (void **)&gop_handle); + if (status != EFI_SUCCESS) + return status; + + status = efi_call_early(locate_handle, + EFI_LOCATE_BY_PROTOCOL, + proto, NULL, &size, gop_handle); + if (status != EFI_SUCCESS) + goto free_handle; + + if (efi_is_64bit()) { + status = setup_gop64(sys_table_arg, si, proto, size, + gop_handle); + } else { + status = setup_gop32(sys_table_arg, si, proto, size, + gop_handle); + } + +free_handle: + efi_call_early(free_pool, gop_handle); + return status; +} diff --git a/drivers/firmware/efi/libstub/random.c b/drivers/firmware/efi/libstub/random.c new file mode 100644 index 000000000..e0e603a89 --- /dev/null +++ b/drivers/firmware/efi/libstub/random.c @@ -0,0 +1,192 @@ +/* + * Copyright (C) 2016 Linaro Ltd; <ard.biesheuvel@linaro.org> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + */ + +#include <linux/efi.h> +#include <linux/log2.h> +#include <asm/efi.h> + +#include "efistub.h" + +struct efi_rng_protocol { + efi_status_t (*get_info)(struct efi_rng_protocol *, + unsigned long *, efi_guid_t *); + efi_status_t (*get_rng)(struct efi_rng_protocol *, + efi_guid_t *, unsigned long, u8 *out); +}; + +efi_status_t efi_get_random_bytes(efi_system_table_t *sys_table_arg, + unsigned long size, u8 *out) +{ + efi_guid_t rng_proto = EFI_RNG_PROTOCOL_GUID; + efi_status_t status; + struct efi_rng_protocol *rng; + + status = efi_call_early(locate_protocol, &rng_proto, NULL, + (void **)&rng); + if (status != EFI_SUCCESS) + return status; + + return rng->get_rng(rng, NULL, size, out); +} + +/* + * Return the number of slots covered by this entry, i.e., the number of + * addresses it covers that are suitably aligned and supply enough room + * for the allocation. + */ +static unsigned long get_entry_num_slots(efi_memory_desc_t *md, + unsigned long size, + unsigned long align_shift) +{ + unsigned long align = 1UL << align_shift; + u64 first_slot, last_slot, region_end; + + if (md->type != EFI_CONVENTIONAL_MEMORY) + return 0; + + region_end = min((u64)ULONG_MAX, md->phys_addr + md->num_pages*EFI_PAGE_SIZE - 1); + + first_slot = round_up(md->phys_addr, align); + last_slot = round_down(region_end - size + 1, align); + + if (first_slot > last_slot) + return 0; + + return ((unsigned long)(last_slot - first_slot) >> align_shift) + 1; +} + +/* + * The UEFI memory descriptors have a virtual address field that is only used + * when installing the virtual mapping using SetVirtualAddressMap(). Since it + * is unused here, we can reuse it to keep track of each descriptor's slot + * count. + */ +#define MD_NUM_SLOTS(md) ((md)->virt_addr) + +efi_status_t efi_random_alloc(efi_system_table_t *sys_table_arg, + unsigned long size, + unsigned long align, + unsigned long *addr, + unsigned long random_seed) +{ + unsigned long map_size, desc_size, total_slots = 0, target_slot; + unsigned long buff_size; + efi_status_t status; + efi_memory_desc_t *memory_map; + int map_offset; + struct efi_boot_memmap map; + + map.map = &memory_map; + map.map_size = &map_size; + map.desc_size = &desc_size; + map.desc_ver = NULL; + map.key_ptr = NULL; + map.buff_size = &buff_size; + + status = efi_get_memory_map(sys_table_arg, &map); + if (status != EFI_SUCCESS) + return status; + + if (align < EFI_ALLOC_ALIGN) + align = EFI_ALLOC_ALIGN; + + /* count the suitable slots in each memory map entry */ + for (map_offset = 0; map_offset < map_size; map_offset += desc_size) { + efi_memory_desc_t *md = (void *)memory_map + map_offset; + unsigned long slots; + + slots = get_entry_num_slots(md, size, ilog2(align)); + MD_NUM_SLOTS(md) = slots; + total_slots += slots; + } + + /* find a random number between 0 and total_slots */ + target_slot = (total_slots * (u16)random_seed) >> 16; + + /* + * target_slot is now a value in the range [0, total_slots), and so + * it corresponds with exactly one of the suitable slots we recorded + * when iterating over the memory map the first time around. + * + * So iterate over the memory map again, subtracting the number of + * slots of each entry at each iteration, until we have found the entry + * that covers our chosen slot. Use the residual value of target_slot + * to calculate the randomly chosen address, and allocate it directly + * using EFI_ALLOCATE_ADDRESS. + */ + for (map_offset = 0; map_offset < map_size; map_offset += desc_size) { + efi_memory_desc_t *md = (void *)memory_map + map_offset; + efi_physical_addr_t target; + unsigned long pages; + + if (target_slot >= MD_NUM_SLOTS(md)) { + target_slot -= MD_NUM_SLOTS(md); + continue; + } + + target = round_up(md->phys_addr, align) + target_slot * align; + pages = round_up(size, EFI_PAGE_SIZE) / EFI_PAGE_SIZE; + + status = efi_call_early(allocate_pages, EFI_ALLOCATE_ADDRESS, + EFI_LOADER_DATA, pages, &target); + if (status == EFI_SUCCESS) + *addr = target; + break; + } + + efi_call_early(free_pool, memory_map); + + return status; +} + +efi_status_t efi_random_get_seed(efi_system_table_t *sys_table_arg) +{ + efi_guid_t rng_proto = EFI_RNG_PROTOCOL_GUID; + efi_guid_t rng_algo_raw = EFI_RNG_ALGORITHM_RAW; + efi_guid_t rng_table_guid = LINUX_EFI_RANDOM_SEED_TABLE_GUID; + struct efi_rng_protocol *rng; + struct linux_efi_random_seed *seed; + efi_status_t status; + + status = efi_call_early(locate_protocol, &rng_proto, NULL, + (void **)&rng); + if (status != EFI_SUCCESS) + return status; + + status = efi_call_early(allocate_pool, EFI_RUNTIME_SERVICES_DATA, + sizeof(*seed) + EFI_RANDOM_SEED_SIZE, + (void **)&seed); + if (status != EFI_SUCCESS) + return status; + + 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, EFI_RANDOM_SEED_SIZE, + seed->bits); + + if (status != EFI_SUCCESS) + goto err_freepool; + + seed->size = EFI_RANDOM_SEED_SIZE; + status = efi_call_early(install_configuration_table, &rng_table_guid, + seed); + if (status != EFI_SUCCESS) + goto err_freepool; + + return EFI_SUCCESS; + +err_freepool: + efi_call_early(free_pool, seed); + return status; +} diff --git a/drivers/firmware/efi/libstub/secureboot.c b/drivers/firmware/efi/libstub/secureboot.c new file mode 100644 index 000000000..72d9dfbeb --- /dev/null +++ b/drivers/firmware/efi/libstub/secureboot.c @@ -0,0 +1,83 @@ +/* + * Secure boot handling. + * + * Copyright (C) 2013,2014 Linaro Limited + * Roy Franz <roy.franz@linaro.org + * Copyright (C) 2013 Red Hat, Inc. + * Mark Salter <msalter@redhat.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" + +/* BIOS variables */ +static const efi_guid_t efi_variable_guid = EFI_GLOBAL_VARIABLE_GUID; +static const efi_char16_t efi_SecureBoot_name[] = L"SecureBoot"; +static const efi_char16_t efi_SetupMode_name[] = L"SetupMode"; + +/* SHIM variables */ +static const efi_guid_t shim_guid = EFI_SHIM_LOCK_GUID; +static const efi_char16_t shim_MokSBState_name[] = L"MokSBState"; + +#define get_efi_var(name, vendor, ...) \ + efi_call_runtime(get_variable, \ + (efi_char16_t *)(name), (efi_guid_t *)(vendor), \ + __VA_ARGS__); + +/* + * Determine whether we're in secure boot mode. + * + * Please keep the logic in sync with + * arch/x86/xen/efi.c:xen_efi_get_secureboot(). + */ +enum efi_secureboot_mode efi_get_secureboot(efi_system_table_t *sys_table_arg) +{ + u32 attr; + u8 secboot, setupmode, moksbstate; + unsigned long size; + efi_status_t status; + + size = sizeof(secboot); + status = get_efi_var(efi_SecureBoot_name, &efi_variable_guid, + NULL, &size, &secboot); + if (status == EFI_NOT_FOUND) + return efi_secureboot_mode_disabled; + if (status != EFI_SUCCESS) + goto out_efi_err; + + size = sizeof(setupmode); + status = get_efi_var(efi_SetupMode_name, &efi_variable_guid, + NULL, &size, &setupmode); + if (status != EFI_SUCCESS) + goto out_efi_err; + + if (secboot == 0 || setupmode == 1) + return efi_secureboot_mode_disabled; + + /* + * See if a user has put the shim into insecure mode. If so, and if the + * variable doesn't have the runtime attribute set, we might as well + * honor that. + */ + size = sizeof(moksbstate); + status = get_efi_var(shim_MokSBState_name, &shim_guid, + &attr, &size, &moksbstate); + + /* If it fails, we don't care why. Default to secure */ + if (status != EFI_SUCCESS) + goto secure_boot_enabled; + if (!(attr & EFI_VARIABLE_RUNTIME_ACCESS) && moksbstate == 1) + return efi_secureboot_mode_disabled; + +secure_boot_enabled: + pr_efi(sys_table_arg, "UEFI Secure Boot is enabled.\n"); + return efi_secureboot_mode_enabled; + +out_efi_err: + pr_efi_err(sys_table_arg, "Could not determine UEFI Secure Boot status.\n"); + return efi_secureboot_mode_unknown; +} diff --git a/drivers/firmware/efi/libstub/string.c b/drivers/firmware/efi/libstub/string.c new file mode 100644 index 000000000..ed10e3f60 --- /dev/null +++ b/drivers/firmware/efi/libstub/string.c @@ -0,0 +1,58 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Taken from: + * linux/lib/string.c + * + * Copyright (C) 1991, 1992 Linus Torvalds + */ + +#include <linux/types.h> +#include <linux/string.h> + +#ifndef __HAVE_ARCH_STRSTR +/** + * strstr - Find the first substring in a %NUL terminated string + * @s1: The string to be searched + * @s2: The string to search for + */ +char *strstr(const char *s1, const char *s2) +{ + size_t l1, l2; + + l2 = strlen(s2); + if (!l2) + return (char *)s1; + l1 = strlen(s1); + while (l1 >= l2) { + l1--; + if (!memcmp(s1, s2, l2)) + return (char *)s1; + s1++; + } + return NULL; +} +#endif + +#ifndef __HAVE_ARCH_STRNCMP +/** + * strncmp - Compare two length-limited strings + * @cs: One string + * @ct: Another string + * @count: The maximum number of bytes to compare + */ +int strncmp(const char *cs, const char *ct, size_t count) +{ + unsigned char c1, c2; + + while (count) { + c1 = *cs++; + c2 = *ct++; + if (c1 != c2) + return c1 < c2 ? -1 : 1; + if (!c1) + break; + count--; + } + return 0; +} +#endif diff --git a/drivers/firmware/efi/libstub/tpm.c b/drivers/firmware/efi/libstub/tpm.c new file mode 100644 index 000000000..a90b0b8fc --- /dev/null +++ b/drivers/firmware/efi/libstub/tpm.c @@ -0,0 +1,136 @@ +/* + * TPM handling. + * + * Copyright (C) 2016 CoreOS, Inc + * Copyright (C) 2017 Google, Inc. + * Matthew Garrett <mjg59@google.com> + * Thiebaud Weksteen <tweek@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 <linux/tpm_eventlog.h> +#include <asm/efi.h> + +#include "efistub.h" + +#ifdef CONFIG_RESET_ATTACK_MITIGATION +static const efi_char16_t efi_MemoryOverWriteRequest_name[] = + L"MemoryOverwriteRequestControl"; + +#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); +} + +#endif + +static void efi_retrieve_tpm2_eventlog_1_2(efi_system_table_t *sys_table_arg) +{ + efi_guid_t tcg2_guid = EFI_TCG2_PROTOCOL_GUID; + efi_guid_t linux_eventlog_guid = LINUX_EFI_TPM_EVENT_LOG_GUID; + efi_status_t status; + efi_physical_addr_t log_location = 0, log_last_entry = 0; + struct linux_efi_tpm_eventlog *log_tbl = NULL; + unsigned long first_entry_addr, last_entry_addr; + size_t log_size, last_entry_size; + efi_bool_t truncated; + void *tcg2_protocol = NULL; + + status = efi_call_early(locate_protocol, &tcg2_guid, NULL, + &tcg2_protocol); + if (status != EFI_SUCCESS) + return; + + status = efi_call_proto(efi_tcg2_protocol, get_event_log, tcg2_protocol, + EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2, + &log_location, &log_last_entry, &truncated); + if (status != EFI_SUCCESS) + return; + + if (!log_location) + return; + first_entry_addr = (unsigned long) log_location; + + /* + * We populate the EFI table even if the logs are empty. + */ + if (!log_last_entry) { + log_size = 0; + } else { + last_entry_addr = (unsigned long) log_last_entry; + /* + * get_event_log only returns the address of the last entry. + * We need to calculate its size to deduce the full size of + * the logs. + */ + last_entry_size = sizeof(struct tcpa_event) + + ((struct tcpa_event *) last_entry_addr)->event_size; + log_size = log_last_entry - log_location + last_entry_size; + } + + /* Allocate space for the logs and copy them. */ + status = efi_call_early(allocate_pool, EFI_LOADER_DATA, + sizeof(*log_tbl) + log_size, + (void **) &log_tbl); + + if (status != EFI_SUCCESS) { + efi_printk(sys_table_arg, + "Unable to allocate memory for event log\n"); + return; + } + + memset(log_tbl, 0, sizeof(*log_tbl) + log_size); + log_tbl->size = log_size; + log_tbl->version = EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2; + memcpy(log_tbl->log, (void *) first_entry_addr, log_size); + + status = efi_call_early(install_configuration_table, + &linux_eventlog_guid, log_tbl); + if (status != EFI_SUCCESS) + goto err_free; + return; + +err_free: + efi_call_early(free_pool, log_tbl); +} + +void efi_retrieve_tpm2_eventlog(efi_system_table_t *sys_table_arg) +{ + /* Only try to retrieve the logs in 1.2 format. */ + efi_retrieve_tpm2_eventlog_1_2(sys_table_arg); +} |