From patchwork Tue Mar 3 22:12:02 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arvind Sankar X-Patchwork-Id: 206493 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7C58FC3F2D1 for ; Tue, 3 Mar 2020 22:12:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4D72C2146E for ; Tue, 3 Mar 2020 22:12:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727429AbgCCWMJ (ORCPT ); Tue, 3 Mar 2020 17:12:09 -0500 Received: from mail-qt1-f195.google.com ([209.85.160.195]:38366 "EHLO mail-qt1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727304AbgCCWMJ (ORCPT ); Tue, 3 Mar 2020 17:12:09 -0500 Received: by mail-qt1-f195.google.com with SMTP id e20so4162957qto.5; Tue, 03 Mar 2020 14:12:08 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=4fjWsKKt+H6bRW7wk8V36+gnsdIQPUzRbjc5HA3/Pg8=; b=oriyw87SsWCn5a4kfmtMnlaoZqor0Y4MZcUVum22Knz3Kyel/2Kkxr6Oefj/0TcrVi Rd3auL26b8OGlCtWERX5I4KqSjIXabSUVafFmxz15hLjH3/s6YC/M5i5I0sAlNeJPYf4 Z/diT049Lus/a+W0nX9JDmhLkezMul94mYxoNiGkginXPfCLDv9xu25W7Vr3M46Lap0P JJTkC9byc69MQA3J79FcIvo9vDnfIK/arSTnl4jO+kL8OsKAyu+v0x19TGXZmxKNjSgt nHsrGOpZUw0FqgR88CelzXLsfT8GwJwAvlhcw50aEPV9ECyocckdDB0HHkpgPnk4xA6d d47g== X-Gm-Message-State: ANhLgQ22xdR0AS+4Vc7j9s/okBK5gtD67T2BBFLfmd/9ZRBO5GZ0yyGe gbHxpavZzNGhOuiAq/TuuDs= X-Google-Smtp-Source: ADFU+vslCZjDyNq899otKjUFwCvL1s8S76eer/1XK1vxAcl6zgtd3vZliWfyNcoX6c3BFPFpst4E+g== X-Received: by 2002:ac8:5452:: with SMTP id d18mr6705777qtq.43.1583273528016; Tue, 03 Mar 2020 14:12:08 -0800 (PST) Received: from rani.riverdale.lan ([2001:470:1f07:5f3::b55f]) by smtp.gmail.com with ESMTPSA id i91sm13267378qtd.70.2020.03.03.14.12.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 03 Mar 2020 14:12:07 -0800 (PST) From: Arvind Sankar To: Ard Biesheuvel Cc: linux-efi@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 2/5] efi/x86: Decompress at start of PE image load address Date: Tue, 3 Mar 2020 17:12:02 -0500 Message-Id: <20200303221205.4048668-3-nivedita@alum.mit.edu> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200303221205.4048668-1-nivedita@alum.mit.edu> References: <20200301230537.2247550-1-nivedita@alum.mit.edu> <20200303221205.4048668-1-nivedita@alum.mit.edu> MIME-Version: 1.0 Sender: linux-efi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-efi@vger.kernel.org When booted via PE loader, define image_offset to hold the offset of startup_32 from the start of the PE image, and use it as the start of the decompression buffer. Signed-off-by: Arvind Sankar --- arch/x86/boot/compressed/head_32.S | 17 ++++++++++ arch/x86/boot/compressed/head_64.S | 42 +++++++++++++++++++++++-- drivers/firmware/efi/libstub/x86-stub.c | 17 ++++++++-- 3 files changed, 70 insertions(+), 6 deletions(-) diff --git a/arch/x86/boot/compressed/head_32.S b/arch/x86/boot/compressed/head_32.S index 894182500606..98b224f5a025 100644 --- a/arch/x86/boot/compressed/head_32.S +++ b/arch/x86/boot/compressed/head_32.S @@ -100,6 +100,19 @@ SYM_FUNC_START(startup_32) #ifdef CONFIG_RELOCATABLE movl %edx, %ebx + +#ifdef CONFIG_EFI_STUB +/* + * If we were loaded via the EFI LoadImage service, startup_32 will be at an + * offset to the start of the space allocated for the image. efi_pe_entry will + * setup image_offset to tell us where the image actually starts, so that we + * can use the full available buffer. + * image_offset = startup_32 - image_base + * Otherwise image_offset will be zero and have no effect on the calculations. + */ + subl image_offset(%edx), %ebx +#endif + movl BP_kernel_alignment(%esi), %eax decl %eax addl %eax, %ebx @@ -226,6 +239,10 @@ SYM_DATA_START_LOCAL(gdt) .quad 0x00cf92000000ffff /* __KERNEL_DS */ SYM_DATA_END_LABEL(gdt, SYM_L_LOCAL, gdt_end) +#ifdef CONFIG_EFI_STUB +SYM_DATA(image_offset, .long 0) +#endif + /* * Stack and heap for uncompression */ diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S index 5d8338a693ce..ae79b50840ad 100644 --- a/arch/x86/boot/compressed/head_64.S +++ b/arch/x86/boot/compressed/head_64.S @@ -99,6 +99,19 @@ SYM_FUNC_START(startup_32) #ifdef CONFIG_RELOCATABLE movl %ebp, %ebx + +#ifdef CONFIG_EFI_STUB +/* + * If we were loaded via the EFI LoadImage service, startup_32 will be at an + * offset to the start of the space allocated for the image. efi_pe_entry will + * setup image_offset to tell us where the image actually starts, so that we + * can use the full available buffer. + * image_offset = startup_32 - image_base + * Otherwise image_offset will be zero and have no effect on the calculations. + */ + subl image_offset(%ebp), %ebx +#endif + movl BP_kernel_alignment(%esi), %eax decl %eax addl %eax, %ebx @@ -111,9 +124,8 @@ SYM_FUNC_START(startup_32) 1: /* Target address to relocate to for decompression */ - movl BP_init_size(%esi), %eax - subl $_end, %eax - addl %eax, %ebx + addl BP_init_size(%esi), %ebx + subl $_end, %ebx /* * Prepare for entering 64 bit mode @@ -299,6 +311,20 @@ SYM_CODE_START(startup_64) /* Start with the delta to where the kernel will run at. */ #ifdef CONFIG_RELOCATABLE leaq startup_32(%rip) /* - $startup_32 */, %rbp + +#ifdef CONFIG_EFI_STUB +/* + * If we were loaded via the EFI LoadImage service, startup_32 will be at an + * offset to the start of the space allocated for the image. efi_pe_entry will + * setup image_offset to tell us where the image actually starts, so that we + * can use the full available buffer. + * image_offset = startup_32 - image_base + * Otherwise image_offset will be zero and have no effect on the calculations. + */ + movl image_offset(%rip), %eax + subq %rax, %rbp +#endif + movl BP_kernel_alignment(%rsi), %eax decl %eax addq %rax, %rbp @@ -647,6 +673,10 @@ SYM_DATA_START_LOCAL(gdt) .quad 0x0000000000000000 /* TS continued */ SYM_DATA_END_LABEL(gdt, SYM_L_LOCAL, gdt_end) +#ifdef CONFIG_EFI_STUB +SYM_DATA(image_offset, .long 0) +#endif + #ifdef CONFIG_EFI_MIXED SYM_DATA_LOCAL(efi32_boot_args, .long 0, 0, 0) SYM_DATA(efi_is64, .byte 1) @@ -712,6 +742,12 @@ SYM_FUNC_START(efi32_pe_entry) movl -4(%ebp), %esi // loaded_image movl LI32_image_base(%esi), %esi // loaded_image->image_base movl %ebx, %ebp // startup_32 for efi32_pe_stub_entry + /* + * We need to set the image_offset variable here since startup_32 will + * use it before we get to the 64-bit efi_pe_entry in C code. + */ + subl %esi, %ebx + movl %ebx, image_offset(%ebp) // save image_offset jmp efi32_pe_stub_entry 2: popl %edi // restore callee-save registers diff --git a/drivers/firmware/efi/libstub/x86-stub.c b/drivers/firmware/efi/libstub/x86-stub.c index 7f3e97c2aad3..e71b8421e088 100644 --- a/drivers/firmware/efi/libstub/x86-stub.c +++ b/drivers/firmware/efi/libstub/x86-stub.c @@ -19,6 +19,7 @@ static efi_system_table_t *sys_table; extern const bool efi_is64; +extern u32 image_offset; __pure efi_system_table_t *efi_system_table(void) { @@ -364,6 +365,7 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle, struct boot_params *boot_params; struct setup_header *hdr; efi_loaded_image_t *image; + void *image_base; efi_guid_t proto = LOADED_IMAGE_PROTOCOL_GUID; int options_size = 0; efi_status_t status; @@ -384,7 +386,10 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle, efi_exit(handle, status); } - hdr = &((struct boot_params *)efi_table_attr(image, image_base))->hdr; + image_base = efi_table_attr(image, image_base); + image_offset = (void *)startup_32 - image_base; + + hdr = &((struct boot_params *)image_base)->hdr; above4g = hdr->xloadflags & XLF_CAN_BE_LOADED_ABOVE_4G; status = efi_allocate_pages(0x4000, (unsigned long *)&boot_params, @@ -399,7 +404,7 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle, hdr = &boot_params->hdr; /* Copy the second sector to boot_params */ - memcpy(&hdr->jump, efi_table_attr(image, image_base) + 512, 512); + memcpy(&hdr->jump, image_base + 512, 512); /* * Fill out some of the header fields ourselves because the @@ -726,7 +731,7 @@ unsigned long efi_main(efi_handle_t handle, * If the kernel isn't already loaded at the preferred load * address, relocate it. */ - if (bzimage_addr != hdr->pref_address) { + if (bzimage_addr - image_offset != hdr->pref_address) { status = efi_relocate_kernel(&bzimage_addr, hdr->init_size, hdr->init_size, hdr->pref_address, @@ -736,6 +741,12 @@ unsigned long efi_main(efi_handle_t handle, efi_printk("efi_relocate_kernel() failed!\n"); goto fail; } + /* + * Now that we've copied the kernel elsewhere, we no longer + * have a setup block before startup_32, so reset image_offset + * to zero in case it was set earlier. + */ + image_offset = 0; } /*