From patchwork Thu Jul 13 13:33:59 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Alexandre Ghiti X-Patchwork-Id: 703849 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 06D94EB64DD for ; Thu, 13 Jul 2023 13:37:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234556AbjGMNhS (ORCPT ); Thu, 13 Jul 2023 09:37:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40568 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234555AbjGMNhR (ORCPT ); Thu, 13 Jul 2023 09:37:17 -0400 Received: from mail-ej1-x631.google.com (mail-ej1-x631.google.com [IPv6:2a00:1450:4864:20::631]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E51B2E68 for ; Thu, 13 Jul 2023 06:37:12 -0700 (PDT) Received: by mail-ej1-x631.google.com with SMTP id a640c23a62f3a-993a37b79e2so119528066b.1 for ; Thu, 13 Jul 2023 06:37:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rivosinc-com.20221208.gappssmtp.com; s=20221208; t=1689255431; x=1691847431; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=62WVSB6WsPMHDl8cD5P6BTPChBTRmrVLO8yDqyWQGGU=; b=YNHxUnRL5n6NNNFNgBTJB/0THlkkKspBbN0/ZFYivX4YQ67c096O5pq8OxWALLes3s iQSmK3fC26NCwFCv6rTzpYRymGwBN2zmr/muLA07foZN3VgAPmBbeWkx/80i9mH7gEAx dl8MBIBSKLA50dZHtL8wyUSy4PrkueNVxfuAcz/VJAAYwsQA2B1l2AooU1MIVxJUDFde VYx67TfN4FaQzaSEVsw5rNQGht2NXU0ZJ5D5LNQNWF3axDSK4wmoHIj3VEhrWE3p23At 2yAqee1Vf/xBucLFvKoubfcsO+FRLg2rS+Y+iE39p5Mc36htaXV2O7e+oQimkscbZ25J kQuA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1689255431; x=1691847431; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=62WVSB6WsPMHDl8cD5P6BTPChBTRmrVLO8yDqyWQGGU=; b=EksVQdjwhVefmhZ2ScCdF3gID5I/vhlTZb6MG8D8aCzBLddLop2aJyOJEfKvxjPLoJ epWsGPfwRA4hQuBg0UYdpRnfdT54tz2tOKlH1Gppn53fPKVjSh2D8SWxrKg7YysP5nJm WX6LaLW5bh62MJqjAunSnI30UZ6bqsM/gEtvYoWIiAry8mHT2NTwie1PDiwaFYHbPeMt 7yVOaSoLndbORBptdzR3jLos/CJ9oTSwhDWnaxjOq6Ol64dh0+AGPftXMsz0LDoGKxjB oLdQMwGeAVnhky48Pay0EJ928NVmAHuwS+axlsH8mbbSS+SfB+eNaIvri5B36Zsy99zX pxTA== X-Gm-Message-State: ABy/qLbTz6eq7fjKaIf43bD/KBt9k+MJ7YQuWFUSiSQrKzTGApiHtg3Q 7yhPoTIUR2enmAfuNeKjG2mYcA== X-Google-Smtp-Source: APBJJlHOtaIqcNPU9mxcYyqPMW9fg+oGYVxfZwwR1DHwPkjaOcJfVpoc1Ej8THBYmFz369bL+W+2Bg== X-Received: by 2002:a17:906:c357:b0:991:e2b6:2189 with SMTP id ci23-20020a170906c35700b00991e2b62189mr1504197ejb.43.1689255431208; Thu, 13 Jul 2023 06:37:11 -0700 (PDT) Received: from alex-rivos.ba.rivosinc.com ([93.23.19.53]) by smtp.gmail.com with ESMTPSA id x8-20020a170906298800b0098df7d0e096sm4014916eje.54.2023.07.13.06.37.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 13 Jul 2023 06:37:10 -0700 (PDT) From: Alexandre Ghiti To: Paul Walmsley , Palmer Dabbelt , Albert Ou , Ard Biesheuvel , linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, linux-efi@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: Alexandre Ghiti Subject: [PATCH v4 3/5] arm64: libstub: Move KASLR handling functions to efi-stub-helper.c Date: Thu, 13 Jul 2023 15:33:59 +0200 Message-Id: <20230713133401.116506-4-alexghiti@rivosinc.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230713133401.116506-1-alexghiti@rivosinc.com> References: <20230713133401.116506-1-alexghiti@rivosinc.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-efi@vger.kernel.org This prepares for riscv to use the same functions to handle the pĥysical kernel move when KASLR is enabled. Signed-off-by: Alexandre Ghiti --- arch/arm64/include/asm/efi.h | 4 + arch/riscv/include/asm/efi.h | 1 + drivers/firmware/efi/libstub/Makefile | 3 +- drivers/firmware/efi/libstub/arm64-stub.c | 117 ++----------- drivers/firmware/efi/libstub/efi-stub-kaslr.c | 159 ++++++++++++++++++ drivers/firmware/efi/libstub/efistub.h | 18 ++ 6 files changed, 197 insertions(+), 105 deletions(-) create mode 100644 drivers/firmware/efi/libstub/efi-stub-kaslr.c diff --git a/arch/arm64/include/asm/efi.h b/arch/arm64/include/asm/efi.h index 4cf2cb053bc8..83a4d69fd968 100644 --- a/arch/arm64/include/asm/efi.h +++ b/arch/arm64/include/asm/efi.h @@ -111,6 +111,7 @@ static inline unsigned long efi_get_kimg_min_align(void) */ return efi_nokaslr ? MIN_KIMG_ALIGN : EFI_KIMG_ALIGN; } +#define efi_get_kimg_min_align efi_get_kimg_min_align #define EFI_ALLOC_ALIGN SZ_64K #define EFI_ALLOC_LIMIT ((1UL << 48) - 1) @@ -168,4 +169,7 @@ static inline void efi_capsule_flush_cache_range(void *addr, int size) efi_status_t efi_handle_corrupted_x18(efi_status_t s, const char *f); +void efi_icache_sync(unsigned long start, unsigned long end); +#define efi_icache_sync efi_icache_sync + #endif /* _ASM_EFI_H */ diff --git a/arch/riscv/include/asm/efi.h b/arch/riscv/include/asm/efi.h index 29e9a0d84b16..c3dafaab36a2 100644 --- a/arch/riscv/include/asm/efi.h +++ b/arch/riscv/include/asm/efi.h @@ -43,6 +43,7 @@ static inline unsigned long efi_get_kimg_min_align(void) */ return IS_ENABLED(CONFIG_64BIT) ? SZ_2M : SZ_4M; } +#define efi_get_kimg_min_align efi_get_kimg_min_align #define EFI_KIMG_PREFERRED_ADDRESS efi_get_kimg_min_align() diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile index 16d64a34d1e1..5927fab5c834 100644 --- a/drivers/firmware/efi/libstub/Makefile +++ b/drivers/firmware/efi/libstub/Makefile @@ -67,7 +67,8 @@ 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 \ +lib-y := efi-stub-helper.o efi-stub-kaslr.o \ + gop.o secureboot.o tpm.o \ file.o mem.o random.o randomalloc.o pci.o \ skip_spaces.o lib-cmdline.o lib-ctype.o \ alignedmem.o relocate.o printk.o vsprintf.o diff --git a/drivers/firmware/efi/libstub/arm64-stub.c b/drivers/firmware/efi/libstub/arm64-stub.c index 770b8ecb7398..452b7ccd330e 100644 --- a/drivers/firmware/efi/libstub/arm64-stub.c +++ b/drivers/firmware/efi/libstub/arm64-stub.c @@ -14,42 +14,6 @@ #include "efistub.h" -/* - * Distro versions of GRUB may ignore the BSS allocation entirely (i.e., fail - * to provide space, and fail to zero it). Check for this condition by double - * checking that the first and the last byte of the image are covered by the - * same EFI memory map entry. - */ -static bool check_image_region(u64 base, u64 size) -{ - struct efi_boot_memmap *map; - efi_status_t status; - bool ret = false; - int map_offset; - - status = efi_get_memory_map(&map, false); - if (status != EFI_SUCCESS) - return false; - - for (map_offset = 0; map_offset < map->map_size; map_offset += map->desc_size) { - efi_memory_desc_t *md = (void *)map->map + map_offset; - u64 end = md->phys_addr + md->num_pages * EFI_PAGE_SIZE; - - /* - * Find the region that covers base, and return whether - * it covers base+size bytes. - */ - if (base >= md->phys_addr && base < end) { - ret = (base + size) <= end; - break; - } - } - - efi_bs_call(free_pool, map); - - return ret; -} - efi_status_t handle_kernel_image(unsigned long *image_addr, unsigned long *image_size, unsigned long *reserve_addr, @@ -59,31 +23,6 @@ efi_status_t handle_kernel_image(unsigned long *image_addr, { efi_status_t status; unsigned long kernel_size, kernel_codesize, kernel_memsize; - u32 phys_seed = 0; - u64 min_kimg_align = efi_get_kimg_min_align(); - - if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) { - efi_guid_t li_fixed_proto = LINUX_EFI_LOADED_IMAGE_FIXED_GUID; - void *p; - - if (efi_nokaslr) { - efi_info("KASLR disabled on kernel command line\n"); - } else if (efi_bs_call(handle_protocol, image_handle, - &li_fixed_proto, &p) == EFI_SUCCESS) { - efi_info("Image placement fixed by loader\n"); - } else { - status = efi_get_random_bytes(sizeof(phys_seed), - (u8 *)&phys_seed); - if (status == EFI_NOT_FOUND) { - efi_info("EFI_RNG_PROTOCOL unavailable\n"); - efi_nokaslr = true; - } else if (status != EFI_SUCCESS) { - efi_err("efi_get_random_bytes() failed (0x%lx)\n", - status); - efi_nokaslr = true; - } - } - } if (image->image_base != _text) { efi_err("FIRMWARE BUG: efi_loaded_image_t::image_base has bogus value\n"); @@ -98,50 +37,15 @@ efi_status_t handle_kernel_image(unsigned long *image_addr, kernel_codesize = __inittext_end - _text; kernel_memsize = kernel_size + (_end - _edata); *reserve_size = kernel_memsize; + *image_addr = (unsigned long)_text; - if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && phys_seed != 0) { - /* - * If KASLR is enabled, and we have some randomness available, - * locate the kernel at a randomized offset in physical memory. - */ - status = efi_random_alloc(*reserve_size, min_kimg_align, - reserve_addr, phys_seed, - EFI_LOADER_CODE); - if (status != EFI_SUCCESS) - efi_warn("efi_random_alloc() failed: 0x%lx\n", status); - } else { - status = EFI_OUT_OF_RESOURCES; - } - - if (status != EFI_SUCCESS) { - if (!check_image_region((u64)_text, kernel_memsize)) { - efi_err("FIRMWARE BUG: Image BSS overlaps adjacent EFI memory region\n"); - } else if (IS_ALIGNED((u64)_text, min_kimg_align) && - (u64)_end < EFI_ALLOC_LIMIT) { - /* - * Just execute from wherever we were loaded by the - * UEFI PE/COFF loader if the placement is suitable. - */ - *image_addr = (u64)_text; - *reserve_size = 0; - return EFI_SUCCESS; - } - - status = efi_allocate_pages_aligned(*reserve_size, reserve_addr, - ULONG_MAX, min_kimg_align, - EFI_LOADER_CODE); - - if (status != EFI_SUCCESS) { - efi_err("Failed to relocate kernel\n"); - *reserve_size = 0; - return status; - } - } - - *image_addr = *reserve_addr; - memcpy((void *)*image_addr, _text, kernel_size); - caches_clean_inval_pou(*image_addr, *image_addr + kernel_codesize); - efi_remap_image(*image_addr, *reserve_size, kernel_codesize); + status = efi_kaslr_relocate_kernel(image_addr, + reserve_addr, reserve_size, + kernel_size, kernel_codesize, + kernel_memsize, + efi_kaslr_get_phys_seed(image_handle)); + if (status != EFI_SUCCESS) + return status; return EFI_SUCCESS; } @@ -159,3 +63,8 @@ unsigned long primary_entry_offset(void) */ return (char *)primary_entry - _text; } + +void efi_icache_sync(unsigned long start, unsigned long end) +{ + caches_clean_inval_pou(start, end); +} diff --git a/drivers/firmware/efi/libstub/efi-stub-kaslr.c b/drivers/firmware/efi/libstub/efi-stub-kaslr.c new file mode 100644 index 000000000000..be0c8ab0982a --- /dev/null +++ b/drivers/firmware/efi/libstub/efi-stub-kaslr.c @@ -0,0 +1,159 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Helper functions used by the EFI stub on multiple + * architectures to deal with physical address space randomization. + */ +#include + +#include "efistub.h" + +/** + * efi_kaslr_get_phys_seed() - Get random seed for physical kernel KASLR + * @image_handle: Handle to the image + * + * If KASLR is not disabled, obtain a random seed using EFI_RNG_PROTOCOL + * that will be used to move the kernel physical mapping. + * + * Return: the random seed + */ +u32 efi_kaslr_get_phys_seed(efi_handle_t image_handle) +{ + efi_status_t status; + u32 phys_seed; + efi_guid_t li_fixed_proto = LINUX_EFI_LOADED_IMAGE_FIXED_GUID; + void *p; + + if (!IS_ENABLED(CONFIG_RANDOMIZE_BASE)) + return 0; + + if (efi_nokaslr) { + efi_info("KASLR disabled on kernel command line\n"); + } else if (efi_bs_call(handle_protocol, image_handle, + &li_fixed_proto, &p) == EFI_SUCCESS) { + efi_info("Image placement fixed by loader\n"); + } else { + status = efi_get_random_bytes(sizeof(phys_seed), + (u8 *)&phys_seed); + if (status == EFI_SUCCESS) { + return phys_seed; + } else if (status == EFI_NOT_FOUND) { + efi_info("EFI_RNG_PROTOCOL unavailable\n"); + efi_nokaslr = true; + } else if (status != EFI_SUCCESS) { + efi_err("efi_get_random_bytes() failed (0x%lx)\n", + status); + efi_nokaslr = true; + } + } + + return 0; +} + +/* + * Distro versions of GRUB may ignore the BSS allocation entirely (i.e., fail + * to provide space, and fail to zero it). Check for this condition by double + * checking that the first and the last byte of the image are covered by the + * same EFI memory map entry. + */ +static bool check_image_region(u64 base, u64 size) +{ + struct efi_boot_memmap *map; + efi_status_t status; + bool ret = false; + int map_offset; + + status = efi_get_memory_map(&map, false); + if (status != EFI_SUCCESS) + return false; + + for (map_offset = 0; map_offset < map->map_size; map_offset += map->desc_size) { + efi_memory_desc_t *md = (void *)map->map + map_offset; + u64 end = md->phys_addr + md->num_pages * EFI_PAGE_SIZE; + + /* + * Find the region that covers base, and return whether + * it covers base+size bytes. + */ + if (base >= md->phys_addr && base < end) { + ret = (base + size) <= end; + break; + } + } + + efi_bs_call(free_pool, map); + + return ret; +} + +/** + * efi_kaslr_relocate_kernel() - Relocate the kernel (random if KASLR enabled) + * @image_addr: Pointer to the current kernel location + * @reserve_addr: Pointer to the relocated kernel location + * @reserve_size: Size of the relocated kernel + * @kernel_size: Size of the text + data + * @kernel_codesize: Size of the text + * @kernel_memsize: Size of the text + data + bss + * @phys_seed: Random seed used for the relocation + * + * If KASLR is not enabled, this function relocates the kernel to a fixed + * address (or leave it as its current location). If KASLR is enabled, the + * kernel physical location is randomized using the seed in parameter. + * + * Return: status code, EFI_SUCCESS if relocation is successful + */ +efi_status_t efi_kaslr_relocate_kernel(unsigned long *image_addr, + unsigned long *reserve_addr, + unsigned long *reserve_size, + unsigned long kernel_size, + unsigned long kernel_codesize, + unsigned long kernel_memsize, + u32 phys_seed) +{ + efi_status_t status; + u64 min_kimg_align = efi_get_kimg_min_align(); + + if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && phys_seed != 0) { + /* + * If KASLR is enabled, and we have some randomness available, + * locate the kernel at a randomized offset in physical memory. + */ + status = efi_random_alloc(*reserve_size, min_kimg_align, + reserve_addr, phys_seed, + EFI_LOADER_CODE); + if (status != EFI_SUCCESS) + efi_warn("efi_random_alloc() failed: 0x%lx\n", status); + } else { + status = EFI_OUT_OF_RESOURCES; + } + + if (status != EFI_SUCCESS) { + if (!check_image_region(*image_addr, kernel_memsize)) { + efi_err("FIRMWARE BUG: Image BSS overlaps adjacent EFI memory region\n"); + } else if (IS_ALIGNED(*image_addr, min_kimg_align) && + (u64)_end < EFI_ALLOC_LIMIT) { + /* + * Just execute from wherever we were loaded by the + * UEFI PE/COFF loader if the placement is suitable. + */ + *reserve_size = 0; + return EFI_SUCCESS; + } + + status = efi_allocate_pages_aligned(*reserve_size, reserve_addr, + ULONG_MAX, min_kimg_align, + EFI_LOADER_CODE); + + if (status != EFI_SUCCESS) { + efi_err("Failed to relocate kernel\n"); + *reserve_size = 0; + return status; + } + } + + memcpy((void *)*reserve_addr, (void *)*image_addr, kernel_size); + *image_addr = *reserve_addr; + efi_icache_sync(*image_addr, *image_addr + kernel_codesize); + efi_remap_image(*image_addr, *reserve_size, kernel_codesize); + + return status; +} diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h index 6aa38a1bf126..35337ea5056e 100644 --- a/drivers/firmware/efi/libstub/efistub.h +++ b/drivers/firmware/efi/libstub/efistub.h @@ -1132,6 +1132,24 @@ const u8 *__efi_get_smbios_string(const struct efi_smbios_record *record, void efi_remap_image(unsigned long image_base, unsigned alloc_size, unsigned long code_size); +efi_status_t efi_kaslr_relocate_kernel(unsigned long *image_addr, + unsigned long *reserve_addr, + unsigned long *reserve_size, + unsigned long kernel_size, + unsigned long kernel_codesize, + unsigned long kernel_memsize, + u32 phys_seed); +u32 efi_kaslr_get_phys_seed(efi_handle_t image_handle); + +#ifndef efi_get_kimg_min_align +static inline unsigned long efi_get_kimg_min_align(void) { return 0; } +#define efi_get_kimg_min_align efi_get_kimg_min_align +#endif + +#ifndef efi_icache_sync +static inline void efi_icache_sync(unsigned long start, unsigned long end) {} +#define efi_icache_sync efi_icache_sync +#endif asmlinkage efi_status_t __efiapi efi_zboot_entry(efi_handle_t handle, efi_system_table_t *systab);