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[23.128.96.18]) by mx.google.com with ESMTP id u2si3474420edy.335.2021.10.20.10.46.38; Wed, 20 Oct 2021 10:47:03 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=xmission.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230365AbhJTRq6 (ORCPT + 99 others); Wed, 20 Oct 2021 13:46:58 -0400 Received: from out02.mta.xmission.com ([166.70.13.232]:40414 "EHLO out02.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230031AbhJTRq5 (ORCPT ); Wed, 20 Oct 2021 13:46:57 -0400 Received: from in02.mta.xmission.com ([166.70.13.52]:54948) by out02.mta.xmission.com with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1mdFdp-00GCv6-SX; Wed, 20 Oct 2021 11:44:41 -0600 Received: from ip68-227-160-95.om.om.cox.net ([68.227.160.95]:47894 helo=localhost.localdomain) by in02.mta.xmission.com with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1mdFdo-001NdN-VK; Wed, 20 Oct 2021 11:44:41 -0600 From: "Eric W. Biederman" To: linux-kernel@vger.kernel.org Cc: linux-arch@vger.kernel.org, Linus Torvalds , Oleg Nesterov , Al Viro , Kees Cook , "Eric W. Biederman" , Andy Lutomirski Date: Wed, 20 Oct 2021 12:43:47 -0500 Message-Id: <20211020174406.17889-1-ebiederm@xmission.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <87y26nmwkb.fsf@disp2133> References: <87y26nmwkb.fsf@disp2133> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-XM-SPF: eid=1mdFdo-001NdN-VK;;;mid=<20211020174406.17889-1-ebiederm@xmission.com>;;;hst=in02.mta.xmission.com;;;ip=68.227.160.95;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX1/vH9BzxZMJil3hyUi3PHXKmsFqUHXgmG4= X-SA-Exim-Connect-IP: 68.227.160.95 X-SA-Exim-Mail-From: ebiederm@xmission.com X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on sa07.xmission.com X-Spam-Level: ** X-Spam-Status: No, score=2.5 required=8.0 tests=ALL_TRUSTED,BAYES_50, DCC_CHECK_NEGATIVE,T_TM2_M_HEADER_IN_MSG,T_TooManySym_01, XMGappySubj_01,XMNoVowels,XMSubLong autolearn=disabled version=3.4.2 X-Spam-Report: * -1.0 ALL_TRUSTED Passed through trusted hosts only via SMTP * 0.8 BAYES_50 BODY: Bayes spam probability is 40 to 60% * [score: 0.5043] * 0.7 XMSubLong Long Subject * 0.5 XMGappySubj_01 Very gappy subject * 1.5 XMNoVowels Alpha-numberic number with no vowels * 0.0 T_TM2_M_HEADER_IN_MSG BODY: No description available. * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa07 1397; Body=1 Fuz1=1 Fuz2=1] * 0.0 T_TooManySym_01 4+ unique symbols in subject X-Spam-DCC: XMission; sa07 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: **;linux-kernel@vger.kernel.org X-Spam-Relay-Country: X-Spam-Timing: total 321 ms - load_scoreonly_sql: 0.05 (0.0%), signal_user_changed: 11 (3.4%), b_tie_ro: 9 (2.9%), parse: 0.89 (0.3%), extract_message_metadata: 12 (3.6%), get_uri_detail_list: 1.05 (0.3%), tests_pri_-1000: 15 (4.7%), tests_pri_-950: 1.87 (0.6%), tests_pri_-900: 1.51 (0.5%), tests_pri_-90: 85 (26.4%), check_bayes: 83 (25.8%), b_tokenize: 5 (1.7%), b_tok_get_all: 6 (1.9%), b_comp_prob: 2.1 (0.7%), b_tok_touch_all: 66 (20.4%), b_finish: 0.86 (0.3%), tests_pri_0: 183 (56.9%), check_dkim_signature: 1.30 (0.4%), check_dkim_adsp: 3.3 (1.0%), poll_dns_idle: 1.09 (0.3%), tests_pri_10: 2.1 (0.7%), tests_pri_500: 7 (2.1%), rewrite_mail: 0.00 (0.0%) Subject: [PATCH 01/20] exit/doublefault: Remove apparently bogus comment about rewind_stack_do_exit X-SA-Exim-Version: 4.2.1 (built Sat, 08 Feb 2020 21:53:50 +0000) X-SA-Exim-Scanned: Yes (on in02.mta.xmission.com) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org I do not see panic calling rewind_stack_do_exit anywhere, nor can I find anywhere in the history where doublefault_shim has called rewind_stack_do_exit. So I don't think this comment was ever actually correct. Cc: Andy Lutomirski Fixes: 7d8d8cfdee9a ("x86/doublefault/32: Rewrite the x86_32 #DF handler and unify with 64-bit") Signed-off-by: "Eric W. Biederman" --- arch/x86/kernel/doublefault_32.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/arch/x86/kernel/doublefault_32.c b/arch/x86/kernel/doublefault_32.c index d1d49e3d536b..3b58d8703094 100644 --- a/arch/x86/kernel/doublefault_32.c +++ b/arch/x86/kernel/doublefault_32.c @@ -77,9 +77,6 @@ asmlinkage noinstr void __noreturn doublefault_shim(void) * some way to reconstruct CR3. We could make a credible guess based * on cpu_tlbstate, but that would be racy and would not account for * PTI. - * - * Instead, don't bother. We can return through - * rewind_stack_do_exit() instead. */ panic("cannot return from double fault\n"); } -- 2.20.1