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 X-Spam-Level: X-Spam-Status: No, score=-13.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 D7545C3F2C6 for ; Tue, 3 Mar 2020 08:22:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AD383208C3 for ; Tue, 3 Mar 2020 08:22:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="hZbDznaZ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727762AbgCCIWU (ORCPT ); Tue, 3 Mar 2020 03:22:20 -0500 Received: from mail-ot1-f65.google.com ([209.85.210.65]:33335 "EHLO mail-ot1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727552AbgCCIWU (ORCPT ); Tue, 3 Mar 2020 03:22:20 -0500 Received: by mail-ot1-f65.google.com with SMTP id a20so2190225otl.0 for ; Tue, 03 Mar 2020 00:22:19 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=J6EQLN6SsV+VtgLYWfNW0nRQASGUiBeXhHQHvZKJ4CM=; b=hZbDznaZ/8zfBcFNm9kigkVMeGC6gcQiALbMrjg9x+FlQxJib35GOZl92cSdumutaE U7FSTh0ijgCdKOx+r+oyAWyQWcNkdBPidCgNjimPTphK/g+WBNZJFBQev2SglQTbnD2s m72K1E1kh7gBRu7lXn3J8tJ0HHYRs+ySyFEFGNc7/OBNNGXhANK7MJB/7uvb2smBAsmN X8q1Qq/2Ea1ndNBbyni9z7LB3kA3dkRYHVHp3FY86f2na3xV4CBu6kxvCe4GTFdsqZXd qZyXrHTrYarAicnMeJRD8bYnuzHq8gco5tpSCphuIt60rjobptzJCkgUq+Ltp2iiDyOP 68tw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=J6EQLN6SsV+VtgLYWfNW0nRQASGUiBeXhHQHvZKJ4CM=; b=XztpngwEg33JienY9NTaOfhEFf0QrXSBcB7CSer6zZxOXnCQ/aMuC35hQSXxy2Uu8O gUr6hMjBBtq4lSDYSRUUo4+zQEv9aOxuXtPZq1+nX/isLQJLwhUnV1vDJbzvk9lmE0gb YDqxnsXQBnuPv8wzIuYnDDv/wdoXQ8R3NDeph9/z3u2qy04dbLPbzsRZssPOyGZpFY5D a33tpj+zYBAWnR+Pm2055GwHoyVMNVTOn2xqxFxALwHB2byEwJSznrBfF6CxpMj150LR +Asa7u6jjqBNc+wwUkT2sV1s4Dodn6I4vddRCJngzvW+9EIs8kIXsUEJoWT6nqD8wp0A rCkw== X-Gm-Message-State: ANhLgQ2Qu5B1EN7B13OV7IycqoB2Fc54luRiQbzjTzmQG7J4b2pZIN+D rLw75UdgC+47KHMN4KWqxEo= X-Google-Smtp-Source: ADFU+vs3plHE9nYhKfQDxvmFG8+9WILVpVzK3A+RHAgy9utC/dqzLEkFiIDUuwR/Ep7U9XmohuFBQQ== X-Received: by 2002:a05:6830:1d6e:: with SMTP id l14mr2494839oti.32.1583223739028; Tue, 03 Mar 2020 00:22:19 -0800 (PST) Received: from ubuntu-m2-xlarge-x86 ([2604:1380:4111:8b00::1]) by smtp.gmail.com with ESMTPSA id m18sm7540298otf.6.2020.03.03.00.22.18 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 03 Mar 2020 00:22:18 -0800 (PST) Date: Tue, 3 Mar 2020 01:22:16 -0700 From: Nathan Chancellor To: Ard Biesheuvel Cc: linux-efi@vger.kernel.org Subject: Re: [PATCH] efi/libstub/x86: deal with exit() boot service returning Message-ID: <20200303082216.GA16908@ubuntu-m2-xlarge-x86> References: <20200303080648.21427-1-ardb@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200303080648.21427-1-ardb@kernel.org> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-efi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-efi@vger.kernel.org On Tue, Mar 03, 2020 at 09:06:48AM +0100, Ard Biesheuvel wrote: > Even though it is uncommon, there are cases where the Exit() EFI boot > service might return, e.g., when we were booted via the EFI handover > protocol from OVMF and the kernel image was specified on the command > line, in which case Exit() attempts to terminate the boot manager, > which is not an EFI application itself. So let's drop into a deadloop > instead. > > Cc: Nathan Chancellor > Signed-off-by: Ard Biesheuvel > --- > As a side effect, this also fixes [0], which is as yet undiagnosed. > > [0] https://github.com/ClangBuiltLinux/linux/issues/917 And for that: Tested-by: Nathan Chancellor # build > drivers/firmware/efi/libstub/x86-stub.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/firmware/efi/libstub/x86-stub.c b/drivers/firmware/efi/libstub/x86-stub.c > index 7f3e97c2aad3..5c7480c4d379 100644 > --- a/drivers/firmware/efi/libstub/x86-stub.c > +++ b/drivers/firmware/efi/libstub/x86-stub.c > @@ -344,7 +344,7 @@ static void setup_graphics(struct boot_params *boot_params) > static void __noreturn efi_exit(efi_handle_t handle, efi_status_t status) > { > efi_bs_call(exit, handle, status, 0, NULL); > - unreachable(); > + for(;;); I thought this would have tripped up clang's -Wempty-body but it doesn't so that is good. > } > > void startup_32(struct boot_params *boot_params); > -- > 2.17.1 >