diff options
Diffstat (limited to 'drivers/firmware/efi/libstub')
| -rw-r--r-- | drivers/firmware/efi/libstub/Makefile | 4 | ||||
| -rw-r--r-- | drivers/firmware/efi/libstub/arm64-entry.S | 67 | ||||
| -rw-r--r-- | drivers/firmware/efi/libstub/arm64-stub.c | 26 | ||||
| -rw-r--r-- | drivers/firmware/efi/libstub/arm64.c | 50 | ||||
| -rw-r--r-- | drivers/firmware/efi/libstub/efi-stub-helper.c | 67 | ||||
| -rw-r--r-- | drivers/firmware/efi/libstub/efistub.h | 23 | ||||
| -rw-r--r-- | drivers/firmware/efi/libstub/zboot.c | 2 |
7 files changed, 153 insertions, 86 deletions
diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile index be8b8c6e8b40..80d85a5169fb 100644 --- a/drivers/firmware/efi/libstub/Makefile +++ b/drivers/firmware/efi/libstub/Makefile @@ -87,7 +87,7 @@ lib-$(CONFIG_EFI_GENERIC_STUB) += efi-stub.o string.o intrinsics.o systable.o \ screen_info.o efi-stub-entry.o lib-$(CONFIG_ARM) += arm32-stub.o -lib-$(CONFIG_ARM64) += arm64.o arm64-stub.o arm64-entry.o smbios.o +lib-$(CONFIG_ARM64) += arm64.o arm64-stub.o smbios.o lib-$(CONFIG_X86) += x86-stub.o lib-$(CONFIG_RISCV) += riscv.o riscv-stub.o lib-$(CONFIG_LOONGARCH) += loongarch.o loongarch-stub.o @@ -141,7 +141,7 @@ STUBCOPY_RELOC-$(CONFIG_ARM) := R_ARM_ABS # STUBCOPY_FLAGS-$(CONFIG_ARM64) += --prefix-alloc-sections=.init \ --prefix-symbols=__efistub_ -STUBCOPY_RELOC-$(CONFIG_ARM64) := R_AARCH64_ABS64 +STUBCOPY_RELOC-$(CONFIG_ARM64) := R_AARCH64_ABS # For RISC-V, we don't need anything special other than arm64. Keep all the # symbols in .init section and make sure that no absolute symbols references diff --git a/drivers/firmware/efi/libstub/arm64-entry.S b/drivers/firmware/efi/libstub/arm64-entry.S deleted file mode 100644 index b5c17e89a4fc..000000000000 --- a/drivers/firmware/efi/libstub/arm64-entry.S +++ /dev/null @@ -1,67 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0-only */ -/* - * EFI entry point. - * - * Copyright (C) 2013, 2014 Red Hat, Inc. - * Author: Mark Salter <msalter@redhat.com> - */ -#include <linux/linkage.h> -#include <asm/assembler.h> - - /* - * The entrypoint of a arm64 bare metal image is at offset #0 of the - * image, so this is a reasonable default for primary_entry_offset. - * Only when the EFI stub is integrated into the core kernel, it is not - * guaranteed that the PE/COFF header has been copied to memory too, so - * in this case, primary_entry_offset should be overridden by the - * linker and point to primary_entry() directly. - */ - .weak primary_entry_offset - -SYM_CODE_START(efi_enter_kernel) - /* - * efi_pe_entry() will have copied the kernel image if necessary and we - * end up here with device tree address in x1 and the kernel entry - * point stored in x0. Save those values in registers which are - * callee preserved. - */ - ldr w2, =primary_entry_offset - add x19, x0, x2 // relocated Image entrypoint - - mov x0, x1 // DTB address - mov x1, xzr - mov x2, xzr - mov x3, xzr - - /* - * Clean the remainder of this routine to the PoC - * so that we can safely disable the MMU and caches. - */ - adr x4, 1f - dc civac, x4 - dsb sy - - /* Turn off Dcache and MMU */ - mrs x4, CurrentEL - cmp x4, #CurrentEL_EL2 - mrs x4, sctlr_el1 - b.ne 0f - mrs x4, sctlr_el2 -0: bic x4, x4, #SCTLR_ELx_M - bic x4, x4, #SCTLR_ELx_C - b.eq 1f - b 2f - - .balign 32 -1: pre_disable_mmu_workaround - msr sctlr_el2, x4 - isb - br x19 // jump to kernel entrypoint - -2: pre_disable_mmu_workaround - msr sctlr_el1, x4 - isb - br x19 // jump to kernel entrypoint - - .org 1b + 32 -SYM_CODE_END(efi_enter_kernel) diff --git a/drivers/firmware/efi/libstub/arm64-stub.c b/drivers/firmware/efi/libstub/arm64-stub.c index 7327b98d8e3f..d4a6b12a8741 100644 --- a/drivers/firmware/efi/libstub/arm64-stub.c +++ b/drivers/firmware/efi/libstub/arm64-stub.c @@ -58,7 +58,7 @@ efi_status_t handle_kernel_image(unsigned long *image_addr, efi_handle_t image_handle) { efi_status_t status; - unsigned long kernel_size, kernel_memsize = 0; + unsigned long kernel_size, kernel_codesize, kernel_memsize; u32 phys_seed = 0; u64 min_kimg_align = efi_get_kimg_min_align(); @@ -93,6 +93,7 @@ efi_status_t handle_kernel_image(unsigned long *image_addr, SEGMENT_ALIGN >> 10); kernel_size = _edata - _text; + kernel_codesize = __inittext_end - _text; kernel_memsize = kernel_size + (_end - _edata); *reserve_size = kernel_memsize; @@ -121,7 +122,7 @@ efi_status_t handle_kernel_image(unsigned long *image_addr, */ *image_addr = (u64)_text; *reserve_size = 0; - goto clean_image_to_poc; + return EFI_SUCCESS; } status = efi_allocate_pages_aligned(*reserve_size, reserve_addr, @@ -137,14 +138,21 @@ efi_status_t handle_kernel_image(unsigned long *image_addr, *image_addr = *reserve_addr; memcpy((void *)*image_addr, _text, kernel_size); + caches_clean_inval_pou(*image_addr, *image_addr + kernel_codesize); -clean_image_to_poc: + return EFI_SUCCESS; +} + +asmlinkage void primary_entry(void); + +unsigned long primary_entry_offset(void) +{ /* - * Clean the copied Image to the PoC, and ensure it is not shadowed by - * stale icache entries from before relocation. + * When built as part of the kernel, the EFI stub cannot branch to the + * kernel proper via the image header, as the PE/COFF header is + * strictly not part of the in-memory presentation of the image, only + * of the file representation. So instead, we need to jump to the + * actual entrypoint in the .text region of the image. */ - dcache_clean_poc(*image_addr, *image_addr + kernel_size); - asm("ic ialluis"); - - return EFI_SUCCESS; + return (char *)primary_entry - _text; } diff --git a/drivers/firmware/efi/libstub/arm64.c b/drivers/firmware/efi/libstub/arm64.c index ff2d18c42ee7..399770266372 100644 --- a/drivers/firmware/efi/libstub/arm64.c +++ b/drivers/firmware/efi/libstub/arm64.c @@ -19,10 +19,13 @@ static bool system_needs_vamap(void) const u8 *type1_family = efi_get_smbios_string(1, family); /* - * Ampere Altra machines crash in SetTime() if SetVirtualAddressMap() - * has not been called prior. + * Ampere eMAG, Altra, and Altra Max machines crash in SetTime() if + * SetVirtualAddressMap() has not been called prior. */ - if (!type1_family || strcmp(type1_family, "Altra")) + if (!type1_family || ( + strcmp(type1_family, "eMAG") && + strcmp(type1_family, "Altra") && + strcmp(type1_family, "Altra Max"))) return false; efi_warn("Working around broken SetVirtualAddressMap()\n"); @@ -56,6 +59,12 @@ efi_status_t check_platform_features(void) return EFI_SUCCESS; } +#ifdef CONFIG_ARM64_WORKAROUND_CLEAN_CACHE +#define DCTYPE "civac" +#else +#define DCTYPE "cvau" +#endif + void efi_cache_sync_image(unsigned long image_base, unsigned long alloc_size, unsigned long code_size) @@ -64,13 +73,38 @@ void efi_cache_sync_image(unsigned long image_base, u64 lsize = 4 << cpuid_feature_extract_unsigned_field(ctr, CTR_EL0_DminLine_SHIFT); - do { - asm("dc civac, %0" :: "r"(image_base)); - image_base += lsize; - alloc_size -= lsize; - } while (alloc_size >= lsize); + /* only perform the cache maintenance if needed for I/D coherency */ + if (!(ctr & BIT(CTR_EL0_IDC_SHIFT))) { + do { + asm("dc " DCTYPE ", %0" :: "r"(image_base)); + image_base += lsize; + code_size -= lsize; + } while (code_size >= lsize); + } asm("ic ialluis"); dsb(ish); isb(); } + +unsigned long __weak primary_entry_offset(void) +{ + /* + * By default, we can invoke the kernel via the branch instruction in + * the image header, so offset #0. This will be overridden by the EFI + * stub build that is linked into the core kernel, as in that case, the + * image header may not have been loaded into memory, or may be mapped + * with non-executable permissions. + */ + return 0; +} + +void __noreturn efi_enter_kernel(unsigned long entrypoint, + unsigned long fdt_addr, + unsigned long fdt_size) +{ + void (* __noreturn enter_kernel)(u64, u64, u64, u64); + + enter_kernel = (void *)entrypoint + primary_entry_offset(); + enter_kernel(fdt_addr, 0, 0, 0); +} diff --git a/drivers/firmware/efi/libstub/efi-stub-helper.c b/drivers/firmware/efi/libstub/efi-stub-helper.c index f5a4bdacac64..1e0203d74691 100644 --- a/drivers/firmware/efi/libstub/efi-stub-helper.c +++ b/drivers/firmware/efi/libstub/efi-stub-helper.c @@ -651,3 +651,70 @@ efi_status_t efi_wait_for_key(unsigned long usec, efi_input_key_t *key) return status; } + +/** + * efi_remap_image - Remap a loaded image with the appropriate permissions + * for code and data + * + * @image_base: the base of the image in memory + * @alloc_size: the size of the area in memory occupied by the image + * @code_size: the size of the leading part of the image containing code + * and read-only data + * + * efi_remap_image() uses the EFI memory attribute protocol to remap the code + * region of the loaded image read-only/executable, and the remainder + * read-write/non-executable. The code region is assumed to start at the base + * of the image, and will therefore cover the PE/COFF header as well. + */ +void efi_remap_image(unsigned long image_base, unsigned alloc_size, + unsigned long code_size) +{ + efi_guid_t guid = EFI_MEMORY_ATTRIBUTE_PROTOCOL_GUID; + efi_memory_attribute_protocol_t *memattr; + efi_status_t status; + u64 attr; + + /* + * If the firmware implements the EFI_MEMORY_ATTRIBUTE_PROTOCOL, let's + * invoke it to remap the text/rodata region of the decompressed image + * as read-only and the data/bss region as non-executable. + */ + status = efi_bs_call(locate_protocol, &guid, NULL, (void **)&memattr); + if (status != EFI_SUCCESS) + return; + + // Get the current attributes for the entire region + status = memattr->get_memory_attributes(memattr, image_base, + alloc_size, &attr); + if (status != EFI_SUCCESS) { + efi_warn("Failed to retrieve memory attributes for image region: 0x%lx\n", + status); + return; + } + + // Mark the code region as read-only + status = memattr->set_memory_attributes(memattr, image_base, code_size, + EFI_MEMORY_RO); + if (status != EFI_SUCCESS) { + efi_warn("Failed to remap code region read-only\n"); + return; + } + + // If the entire region was already mapped as non-exec, clear the + // attribute from the code region. Otherwise, set it on the data + // region. + if (attr & EFI_MEMORY_XP) { + status = memattr->clear_memory_attributes(memattr, image_base, + code_size, + EFI_MEMORY_XP); + if (status != EFI_SUCCESS) + efi_warn("Failed to remap code region executable\n"); + } else { + status = memattr->set_memory_attributes(memattr, + image_base + code_size, + alloc_size - code_size, + EFI_MEMORY_XP); + if (status != EFI_SUCCESS) + efi_warn("Failed to remap data region non-executable\n"); + } +} diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h index 5b8f2c411ed8..6bd3bb86d967 100644 --- a/drivers/firmware/efi/libstub/efistub.h +++ b/drivers/firmware/efi/libstub/efistub.h @@ -442,6 +442,26 @@ union efi_dxe_services_table { } mixed_mode; }; +typedef union efi_memory_attribute_protocol efi_memory_attribute_protocol_t; + +union efi_memory_attribute_protocol { + struct { + efi_status_t (__efiapi *get_memory_attributes)( + efi_memory_attribute_protocol_t *, efi_physical_addr_t, u64, u64 *); + + efi_status_t (__efiapi *set_memory_attributes)( + efi_memory_attribute_protocol_t *, efi_physical_addr_t, u64, u64); + + efi_status_t (__efiapi *clear_memory_attributes)( + efi_memory_attribute_protocol_t *, efi_physical_addr_t, u64, u64); + }; + struct { + u32 get_memory_attributes; + u32 set_memory_attributes; + u32 clear_memory_attributes; + } mixed_mode; +}; + typedef union efi_uga_draw_protocol efi_uga_draw_protocol_t; union efi_uga_draw_protocol { @@ -1076,4 +1096,7 @@ struct efi_smbios_type1_record { const u8 *__efi_get_smbios_string(u8 type, int offset, int recsize); +void efi_remap_image(unsigned long image_base, unsigned alloc_size, + unsigned long code_size); + #endif diff --git a/drivers/firmware/efi/libstub/zboot.c b/drivers/firmware/efi/libstub/zboot.c index 66be5fdc6b58..ba234e062a1a 100644 --- a/drivers/firmware/efi/libstub/zboot.c +++ b/drivers/firmware/efi/libstub/zboot.c @@ -137,6 +137,8 @@ efi_zboot_entry(efi_handle_t handle, efi_system_table_t *systab) efi_cache_sync_image(image_base, alloc_size, code_size); + efi_remap_image(image_base, alloc_size, code_size); + status = efi_stub_common(handle, image, image_base, cmdline_ptr); free_image: |