From patchwork Wed Jun 7 07:23:38 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ard Biesheuvel X-Patchwork-Id: 690329 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 2D043C77B7A for ; Wed, 7 Jun 2023 07:28:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238931AbjFGH2F (ORCPT ); Wed, 7 Jun 2023 03:28:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53796 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239033AbjFGH0r (ORCPT ); Wed, 7 Jun 2023 03:26:47 -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 ED5092D72; Wed, 7 Jun 2023 00:25:11 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id C68F761158; Wed, 7 Jun 2023 07:25:04 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6A596C4339E; Wed, 7 Jun 2023 07:25:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1686122704; bh=DgIwHiqbmr593p9YlPsAqYmPhsSZnjp5/M5rhaPu7Lk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HbIRsV7ajtzb9V60YJCrMao2S2XndXaJgossj0OsUpBPBNvJoErUVKwGh20aRLgYc Su8hyyK+zKzuO+OemgRTc2naA64H/zDUxk/UoPeXOS/4Ncki/4x7AYPY16K0SWmkP9 muku/oWOA066kBNACTi3lTiw6DP7j4mI4SigYu2NzLUbYxm7jzH1uW/j71dygNxDCw vsIZ+M4gFxjI1Uj/AaPDBwpuHbc6V4bzUZgRsiC/JyuwzlQmz8T/T3hc69HkCCngW5 cFO5wR+TEmFDIjq090eHJxgL1jwpNPFSziEztnlRmXa/ySFU57nMlfwV0JFZp4qQtJ YoH+hpZ/cD+lw== From: Ard Biesheuvel To: linux-efi@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Ard Biesheuvel , Evgeniy Baskov , Borislav Petkov , Andy Lutomirski , Dave Hansen , Ingo Molnar , Peter Zijlstra , Thomas Gleixner , Alexey Khoroshilov , Peter Jones , Gerd Hoffmann , Dave Young , Mario Limonciello , Kees Cook , Tom Lendacky , "Kirill A . Shutemov" , Linus Torvalds , Joerg Roedel Subject: [PATCH v5 16/20] x86/decompressor: Move global symbol references to C code Date: Wed, 7 Jun 2023 09:23:38 +0200 Message-Id: <20230607072342.4054036-17-ardb@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230607072342.4054036-1-ardb@kernel.org> References: <20230607072342.4054036-1-ardb@kernel.org> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=5078; i=ardb@kernel.org; h=from:subject; bh=DgIwHiqbmr593p9YlPsAqYmPhsSZnjp5/M5rhaPu7Lk=; b=owGbwMvMwCFmkMcZplerG8N4Wi2JIaXBoCI4JFJK5cSdbQzaEa9WvHAvalOcb2s9b8Vmhcc8r BqL4po7SlkYxDgYZMUUWQRm/3238/REqVrnWbIwc1iZQIYwcHEKwEQsMhn+qZo4R87bcM/hT/HF njsHDvvb/V52aUm4lUq08LLKgyUfNBj+5xkZSV9r7TTybZKvlmIVn6zpEHF1vnTv7LSttU0ai2U 4AQ== X-Developer-Key: i=ardb@kernel.org; a=openpgp; fpr=F43D03328115A198C90016883D200E9CA6329909 Precedence: bulk List-ID: X-Mailing-List: linux-efi@vger.kernel.org It is no longer necessary to be cautious when referring to global variables in the position independent decompressor code, now that it is built using PIE codegen and makes an assertion in the linker script that no GOT entries exist (which would require adjustment for the actual runtime load address of the decompressor binary). This means global variables can be referenced directly from C code, instead of having to pass their runtime addresses into C routines from asm code, which needs to happen at each call site. Do so for the code that will be called directly from the EFI stub after a subsequent patch, and avoid the need to duplicate this logic a third time. Signed-off-by: Ard Biesheuvel --- arch/x86/boot/compressed/head_32.S | 8 -------- arch/x86/boot/compressed/head_64.S | 8 +------- arch/x86/boot/compressed/misc.c | 16 +++++++++------- 3 files changed, 10 insertions(+), 22 deletions(-) diff --git a/arch/x86/boot/compressed/head_32.S b/arch/x86/boot/compressed/head_32.S index 3530465b5b85ccf3..beee858058df4403 100644 --- a/arch/x86/boot/compressed/head_32.S +++ b/arch/x86/boot/compressed/head_32.S @@ -168,13 +168,7 @@ SYM_FUNC_START_LOCAL_NOALIGN(.Lrelocated) */ /* push arguments for extract_kernel: */ - pushl output_len@GOTOFF(%ebx) /* decompressed length, end of relocs */ pushl %ebp /* output address */ - pushl input_len@GOTOFF(%ebx) /* input_len */ - leal input_data@GOTOFF(%ebx), %eax - pushl %eax /* input_data */ - leal boot_heap@GOTOFF(%ebx), %eax - pushl %eax /* heap area */ pushl %esi /* real mode pointer */ call extract_kernel /* returns kernel entry point in %eax */ addl $24, %esp @@ -202,8 +196,6 @@ SYM_DATA_END_LABEL(gdt, SYM_L_LOCAL, gdt_end) */ .bss .balign 4 -boot_heap: - .fill BOOT_HEAP_SIZE, 1, 0 boot_stack: .fill BOOT_STACK_SIZE, 1, 0 boot_stack_end: diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S index 408c7824b647ff51..556ee504325ae50e 100644 --- a/arch/x86/boot/compressed/head_64.S +++ b/arch/x86/boot/compressed/head_64.S @@ -493,11 +493,7 @@ SYM_FUNC_START_LOCAL_NOALIGN(.Lrelocated) * Do the extraction, and jump to the new kernel.. */ movq %r15, %rdi /* pass struct boot_params pointer */ - leaq boot_heap(%rip), %rsi /* malloc area for uncompression */ - leaq input_data(%rip), %rdx /* input_data */ - movl input_len(%rip), %ecx /* input_len */ - movq %rbp, %r8 /* output target address */ - movl output_len(%rip), %r9d /* decompressed length, end of relocs */ + movq %rbp, %rsi /* output target address */ call extract_kernel /* returns kernel entry point in %rax */ /* @@ -639,8 +635,6 @@ SYM_DATA_END_LABEL(boot_idt, SYM_L_GLOBAL, boot_idt_end) */ .bss .balign 4 -SYM_DATA_LOCAL(boot_heap, .fill BOOT_HEAP_SIZE, 1, 0) - SYM_DATA_START_LOCAL(boot_stack) .fill BOOT_STACK_SIZE, 1, 0 .balign 16 diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c index 94b7abcf624b3b55..0b29a3183df42246 100644 --- a/arch/x86/boot/compressed/misc.c +++ b/arch/x86/boot/compressed/misc.c @@ -330,6 +330,11 @@ static size_t parse_elf(void *output) return ehdr.e_entry - LOAD_PHYSICAL_ADDR; } +static u8 boot_heap[BOOT_HEAP_SIZE] __aligned(4); + +extern unsigned char input_data[]; +extern unsigned int input_len, output_len; + /* * The compressed kernel image (ZO), has been moved so that its position * is against the end of the buffer used to hold the uncompressed kernel @@ -347,14 +352,11 @@ static size_t parse_elf(void *output) * |-------uncompressed kernel image---------| * */ -asmlinkage __visible void *extract_kernel(void *rmode, memptr heap, - unsigned char *input_data, - unsigned long input_len, - unsigned char *output, - unsigned long output_len) +asmlinkage __visible void *extract_kernel(void *rmode, unsigned char *output) { const unsigned long kernel_total_size = VO__end - VO__text; unsigned long virt_addr = LOAD_PHYSICAL_ADDR; + memptr heap = (memptr)boot_heap; unsigned long needed_size; size_t entry_offset; @@ -412,7 +414,7 @@ asmlinkage __visible void *extract_kernel(void *rmode, memptr heap, * entries. This ensures the full mapped area is usable RAM * and doesn't include any reserved areas. */ - needed_size = max(output_len, kernel_total_size); + needed_size = max((unsigned long)output_len, kernel_total_size); #ifdef CONFIG_X86_64 needed_size = ALIGN(needed_size, MIN_KERNEL_ALIGN); #endif @@ -443,7 +445,7 @@ asmlinkage __visible void *extract_kernel(void *rmode, memptr heap, #ifdef CONFIG_X86_64 if (heap > 0x3fffffffffffUL) error("Destination address too large"); - if (virt_addr + max(output_len, kernel_total_size) > KERNEL_IMAGE_SIZE) + if (virt_addr + needed_size > KERNEL_IMAGE_SIZE) error("Destination virtual address is beyond the kernel mapping area"); #else if (heap > ((-__PAGE_OFFSET-(128<<20)-1) & 0x7fffffff))