From patchwork Mon Aug 7 16:27:18 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ard Biesheuvel X-Patchwork-Id: 711355 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 42111C001DB for ; Mon, 7 Aug 2023 16:29:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231679AbjHGQ3e (ORCPT ); Mon, 7 Aug 2023 12:29:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35612 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231817AbjHGQ3D (ORCPT ); Mon, 7 Aug 2023 12:29:03 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E3D0E1FCE; Mon, 7 Aug 2023 09:28:25 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 957B561F33; Mon, 7 Aug 2023 16:28:25 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 78F88C433C7; Mon, 7 Aug 2023 16:28:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1691425705; bh=Os+OvcWXVTEgn4GvlOd4rs76sb2kuX0zlm0OhlZtKNw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CBjDo05gh+QlQNGFhuBllM6lpSIft4iqt/Qg8EYCO4EhvuHgIjTz6lhqLgN+00+Jq TxQSdDQGejmUKhXNCA/s0/X8VRUUmD3jJ6b+PUoqHg/UE85lfyyuZ10SlacCMn0YAa vSrgByXq+nzhDhovAq4KXqFcNe18kmM+OLlLZ7AEq40FhmhUJlx9MBNLUJ/MisQQTP zmDsMXqAgOJVPRQZs6kDaPt6IRxiHv5tJJYLebPwLbmOr1AhVuaAZ9gkpvXeQ5p34c CywdeJ1KUBBAmAYo0SJrB7H415S7djl//aELo+Nm/3rE71aLQtAVS03ZP3EJbnFqTg 63OczHKWL29/Q== From: Ard Biesheuvel To: linux-efi@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Ard Biesheuvel , Borislav Petkov , Dave Hansen , Ingo Molnar , Thomas Gleixner Subject: [PATCH v9 21/23] efi/libstub: Add limit argument to efi_random_alloc() Date: Mon, 7 Aug 2023 18:27:18 +0200 Message-Id: <20230807162720.545787-22-ardb@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230807162720.545787-1-ardb@kernel.org> References: <20230807162720.545787-1-ardb@kernel.org> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=3943; i=ardb@kernel.org; h=from:subject; bh=Os+OvcWXVTEgn4GvlOd4rs76sb2kuX0zlm0OhlZtKNw=; b=owGbwMvMwCFmkMcZplerG8N4Wi2JIeWidOoS5do7oTpWZ7leH79/4ptb9c/JjLeZVQWF+MS2F e86L23UUcrCIMbBICumyCIw+++7nacnStU6z5KFmcPKBDKEgYtTACZSGMbwz+wu9+FTaz+8e3ne 7ZaRUG7hlj0neM+e2SPS9bFkQfCHD62MDE2TTt7u57mW0WcR6Tjv2pwZvX3vfZ7nzHeb2n10r6j vExYA X-Developer-Key: i=ardb@kernel.org; a=openpgp; fpr=F43D03328115A198C90016883D200E9CA6329909 Precedence: bulk List-ID: X-Mailing-List: linux-efi@vger.kernel.org x86 will need to limit the kernel memory allocation to the lowest 512 MiB of memory, to match the behavior of the existing bare metal KASLR physical randomization logic. So in preparation for that, add a limit parameter to efi_random_alloc() and wire it up. Signed-off-by: Ard Biesheuvel --- drivers/firmware/efi/libstub/arm64-stub.c | 2 +- drivers/firmware/efi/libstub/efistub.h | 2 +- drivers/firmware/efi/libstub/randomalloc.c | 10 ++++++---- drivers/firmware/efi/libstub/zboot.c | 2 +- 4 files changed, 9 insertions(+), 7 deletions(-) diff --git a/drivers/firmware/efi/libstub/arm64-stub.c b/drivers/firmware/efi/libstub/arm64-stub.c index 770b8ecb73984c61..8c40fc89f5f99209 100644 --- a/drivers/firmware/efi/libstub/arm64-stub.c +++ b/drivers/firmware/efi/libstub/arm64-stub.c @@ -106,7 +106,7 @@ efi_status_t handle_kernel_image(unsigned long *image_addr, */ status = efi_random_alloc(*reserve_size, min_kimg_align, reserve_addr, phys_seed, - EFI_LOADER_CODE); + EFI_LOADER_CODE, EFI_ALLOC_LIMIT); if (status != EFI_SUCCESS) efi_warn("efi_random_alloc() failed: 0x%lx\n", status); } else { diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h index 06b7abc92ced9e18..9823f6fb3e01f718 100644 --- a/drivers/firmware/efi/libstub/efistub.h +++ b/drivers/firmware/efi/libstub/efistub.h @@ -956,7 +956,7 @@ efi_status_t efi_get_random_bytes(unsigned long size, u8 *out); efi_status_t efi_random_alloc(unsigned long size, unsigned long align, unsigned long *addr, unsigned long random_seed, - int memory_type); + int memory_type, unsigned long alloc_limit); efi_status_t efi_random_get_seed(void); diff --git a/drivers/firmware/efi/libstub/randomalloc.c b/drivers/firmware/efi/libstub/randomalloc.c index 32c7a54923b4c127..674a064b8f7adc68 100644 --- a/drivers/firmware/efi/libstub/randomalloc.c +++ b/drivers/firmware/efi/libstub/randomalloc.c @@ -16,7 +16,8 @@ */ static unsigned long get_entry_num_slots(efi_memory_desc_t *md, unsigned long size, - unsigned long align_shift) + unsigned long align_shift, + u64 alloc_limit) { unsigned long align = 1UL << align_shift; u64 first_slot, last_slot, region_end; @@ -29,7 +30,7 @@ static unsigned long get_entry_num_slots(efi_memory_desc_t *md, return 0; region_end = min(md->phys_addr + md->num_pages * EFI_PAGE_SIZE - 1, - (u64)EFI_ALLOC_LIMIT); + alloc_limit); if (region_end < size) return 0; @@ -54,7 +55,8 @@ efi_status_t efi_random_alloc(unsigned long size, unsigned long align, unsigned long *addr, unsigned long random_seed, - int memory_type) + int memory_type, + unsigned long alloc_limit) { unsigned long total_slots = 0, target_slot; unsigned long total_mirrored_slots = 0; @@ -76,7 +78,7 @@ efi_status_t efi_random_alloc(unsigned long size, efi_memory_desc_t *md = (void *)map->map + map_offset; unsigned long slots; - slots = get_entry_num_slots(md, size, ilog2(align)); + slots = get_entry_num_slots(md, size, ilog2(align), alloc_limit); MD_NUM_SLOTS(md) = slots; total_slots += slots; if (md->attribute & EFI_MEMORY_MORE_RELIABLE) diff --git a/drivers/firmware/efi/libstub/zboot.c b/drivers/firmware/efi/libstub/zboot.c index e5d7fa1f1d8fd160..bdb17eac0cb401be 100644 --- a/drivers/firmware/efi/libstub/zboot.c +++ b/drivers/firmware/efi/libstub/zboot.c @@ -119,7 +119,7 @@ efi_zboot_entry(efi_handle_t handle, efi_system_table_t *systab) } status = efi_random_alloc(alloc_size, min_kimg_align, &image_base, - seed, EFI_LOADER_CODE); + seed, EFI_LOADER_CODE, EFI_ALLOC_LIMIT); if (status != EFI_SUCCESS) { efi_err("Failed to allocate memory\n"); goto free_cmdline;