From mboxrd@z Thu Jan 1 00:00:00 1970 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 127A9C07545 for ; Tue, 24 Oct 2023 13:17:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234069AbjJXNRz (ORCPT ); Tue, 24 Oct 2023 09:17:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42930 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232084AbjJXNRy (ORCPT ); Tue, 24 Oct 2023 09:17:54 -0400 Received: from out5-smtp.messagingengine.com (out5-smtp.messagingengine.com [66.111.4.29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 91364C1; Tue, 24 Oct 2023 06:17:52 -0700 (PDT) Received: from compute5.internal (compute5.nyi.internal [10.202.2.45]) by mailout.nyi.internal (Postfix) with ESMTP id CEEBB5C017D; Tue, 24 Oct 2023 09:17:51 -0400 (EDT) Received: from imap51 ([10.202.2.101]) by compute5.internal (MEProxy); Tue, 24 Oct 2023 09:17:51 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=arndb.de; h=cc :cc:content-type:content-type:date:date:from:from:in-reply-to :in-reply-to:message-id:mime-version:references:reply-to:sender :subject:subject:to:to; s=fm2; t=1698153471; x=1698239871; bh=ju LUN5EOf1oun38yO5yy2NS/PjvfZz4177Yn5+hz4yQ=; b=n5JuawavBckG+td4zd 9bgRwuRpqQu0e1li/e77umwTpwdBwy0DLjFX3CyNt7mh81Xb8VYW0gXvlCFWRw6B hj+fijwsz4eR49wI1VEhiMuAzHMpeRbELUPOmwyMHvqXjYp/QUR+9/Se6UYL+T4L WDLTJHnW+8emUnHY2/S3SYHChMwDWnqqUAr12P0GwcRPCfjHc/Vx6zet1zUiY9Ab QW3noxYanY1quUXitS/QIyprE60azjurUOVXm3jRf8IdUBLJOPQUfQwF1h0Y5NGi 6gLzeDZxr2RnAK37E9QNOt1pBZVPzuFw/z/XlaaIMV9UrlXcEYm5x7VM6gugIv8o UBfw== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-type:content-type:date:date :feedback-id:feedback-id:from:from:in-reply-to:in-reply-to :message-id:mime-version:references:reply-to:sender:subject :subject:to:to:x-me-proxy:x-me-proxy:x-me-sender:x-me-sender :x-sasl-enc; s=fm3; t=1698153471; x=1698239871; bh=juLUN5EOf1oun 38yO5yy2NS/PjvfZz4177Yn5+hz4yQ=; b=ho066+fpz4vqxQspl7eYkBvf670M0 QafoG/BnV/LA3QmmYpX25gHOuy6e1KX2q/EJoviBgTiQ8bEtGXhlgixr0PdEtdHP UdgVO0ss1ZYKXyYAaPFpHpAb7uNyOApEx16iBFvqNHtzguv2pCDNgoXgDvDBXbx2 Eum49PB45Qv1wQwNAXunVGDvSL4OeJfcTdyC4QaVURCUcVN4eVgopaLx8oMT2E7V cq9G95XNfiV1VTUkmn6go/PuJpp4x55ovVtU75KGke9BYIzfPM9PljR5ZiBtKHN/ HPitZ1g+BQNBBD4GmNtyUC4pTpD3oY2cjimFc6ZnqS4klc1L3cWmqG2ZQ== X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvkedrkeekgdeiudcutefuodetggdotefrodftvf curfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfghnecu uegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenuc fjughrpefofgggkfgjfhffhffvvefutgesthdtredtreertdenucfhrhhomhepfdetrhhn ugcuuegvrhhgmhgrnhhnfdcuoegrrhhnugesrghrnhgusgdruggvqeenucggtffrrghtth gvrhhnpeffheeugeetiefhgeethfejgfdtuefggeejleehjeeutefhfeeggefhkedtkeet ffenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepmhgrihhlfhhrohhmpegrrh hnugesrghrnhgusgdruggv X-ME-Proxy: Feedback-ID: i56a14606:Fastmail Received: by mailuser.nyi.internal (Postfix, from userid 501) id 5ADF0B60089; Tue, 24 Oct 2023 09:17:51 -0400 (EDT) X-Mailer: MessagingEngine.com Webmail Interface User-Agent: Cyrus-JMAP/3.9.0-alpha0-1048-g9229b632c5-fm-20231019.001-g9229b632 MIME-Version: 1.0 Message-Id: In-Reply-To: References: <20231023110308.1202042-1-arnd@kernel.org> Date: Tue, 24 Oct 2023 15:17:30 +0200 From: "Arnd Bergmann" To: "Baoquan He" Cc: "Vivek Goyal" , "Andrew Morton" , linux-kernel@vger.kernel.org, kexec@lists.infradead.org, x86@kernel.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-crypto@vger.kernel.org, eric_devolder@yahoo.com Subject: Re: [PATCH 1/2] kexec: fix KEXEC_FILE dependencies Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-s390@vger.kernel.org On Tue, Oct 24, 2023, at 14:44, Baoquan He wrote: > Just add people and mailing list to CC since I didn't find this mail in > my box, just drag it via 'b4 am'. > > On 10/23/23 at 01:01pm, Arnd Bergmann wrote: > ...... >> diff --git a/kernel/Kconfig.kexec b/kernel/Kconfig.kexec >> index 7aff28ded2f48..bfc636d64ff2b 100644 >> --- a/kernel/Kconfig.kexec >> +++ b/kernel/Kconfig.kexec >> @@ -36,6 +36,7 @@ config KEXEC >> config KEXEC_FILE >> bool "Enable kexec file based system call" >> depends on ARCH_SUPPORTS_KEXEC_FILE >> + depends on CRYPTO_SHA256=y || !ARCH_SUPPORTS_KEXEC_PURGATORY > > I am not sure if the logic is correct. In theory, kexec_file code > utilizes purgatory to verify the checksum digested during kernel loading > when try to jump to the kernel. That means kexec_file depends on > purgatory, but not contrary? The expression I wrote is a bit confusing, but I think this just keeps the existing behavior: - on architectures that select ARCH_SUPPORTS_KEXEC_PURGATORY (powerpc, riscv, s390 and x86), we also require CRYPTO_SHA256 to be built-in. - on architectures that do not have ARCH_SUPPORTS_KEXEC_PURGATORY (arm64 and parisc), CRYPTO_SHA256 is not used and can be disabled or =m. Since ARCH_SUPPORTS_KEXEC_PURGATORY is a 'bool' symbol, it could be written as depends on (ARCH_SUPPORTS_KEXEC_PURGATORY && CRYPTO_SHA256=y) \ || !ARCH_SUPPORTS_KEXEC_PURGATORY if you find that clearer. I see that the second patch actually gets this wrong, it should actually do select CRYPTO if ARCH_SUPPORTS_KEXEC_PURGATORY select CRYPTO_SHA256 if ARCH_SUPPORTS_KEXEC_PURGATORY > With these changes, we can achieve the goal to avoid building issue, > whereas the code logic becomes confusing. E.g people could disable > CONFIG_KEXEC_FILE, but still get purgatory code built in which is > totally useless. > > Not sure if I think too much over this. I see your point here, and I would suggest changing the CONFIG_ARCH_SUPPORTS_KEXEC_PURGATORY symbol to just indicate the availability of the purgatory code for the arch, rather than actually controlling the code itself. I already mentioned this for s390, but riscv would need the same thing on top. I think the change below should address your concern. Arnd diff --git a/arch/riscv/kernel/elf_kexec.c b/arch/riscv/kernel/elf_kexec.c index e60fbd8660c4..3ac341d296db 100644 --- a/arch/riscv/kernel/elf_kexec.c +++ b/arch/riscv/kernel/elf_kexec.c @@ -266,7 +266,7 @@ static void *elf_kexec_load(struct kimage *image, char *kernel_buf, cmdline = modified_cmdline; } -#ifdef CONFIG_ARCH_SUPPORTS_KEXEC_PURGATORY +#ifdef CONFIG_KEXEC_FILE /* Add purgatory to the image */ kbuf.top_down = true; kbuf.mem = KEXEC_BUF_MEM_UNKNOWN; @@ -280,7 +280,7 @@ static void *elf_kexec_load(struct kimage *image, char *kernel_buf, sizeof(kernel_start), 0); if (ret) pr_err("Error update purgatory ret=%d\n", ret); -#endif /* CONFIG_ARCH_SUPPORTS_KEXEC_PURGATORY */ +#endif /* CONFIG_KEXEC_FILE */ /* Add the initrd to the image */ if (initrd != NULL) { diff --git a/arch/riscv/Kbuild b/arch/riscv/Kbuild index d25ad1c19f88..ab181d187c23 100644 --- a/arch/riscv/Kbuild +++ b/arch/riscv/Kbuild @@ -5,7 +5,7 @@ obj-$(CONFIG_BUILTIN_DTB) += boot/dts/ obj-y += errata/ obj-$(CONFIG_KVM) += kvm/ -obj-$(CONFIG_ARCH_SUPPORTS_KEXEC_PURGATORY) += purgatory/ +obj-$(CONFIG_KEXEC_FILE) += purgatory/ # for cleaning subdir- += boot diff --git a/arch/s390/Kbuild b/arch/s390/Kbuild index a5d3503b353c..361aa01dbd49 100644 --- a/arch/s390/Kbuild +++ b/arch/s390/Kbuild @@ -7,7 +7,7 @@ obj-$(CONFIG_S390_HYPFS) += hypfs/ obj-$(CONFIG_APPLDATA_BASE) += appldata/ obj-y += net/ obj-$(CONFIG_PCI) += pci/ -obj-$(CONFIG_ARCH_SUPPORTS_KEXEC_PURGATORY) += purgatory/ +obj-$(CONFIG_KEXEC_FILE) += purgatory/ # for cleaning subdir- += boot tools