From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com ([209.132.183.28]:33196 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728866AbfJHIyY (ORCPT ); Tue, 8 Oct 2019 04:54:24 -0400 From: Hans de Goede Subject: [RFC v2 0/1] s390/purgatory: Make sure we fail the build if purgatory has missing symbols Date: Tue, 8 Oct 2019 10:54:20 +0200 Message-Id: <20191008085421.11011-1-hdegoede@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-s390-owner@vger.kernel.org List-ID: To: Heiko Carstens , Vasily Gorbik , Christian Borntraeger Cc: Hans de Goede , Arvind Sankar , Nathan Chancellor , linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org Hi s390 maintainers, Here is a second RFC version of my patch for $subject, mirroring the changes in v2 of the x86 patch. As last time this patch is completely UNTESTED. Changes in v2: - Using 2 if_changed lines under a single rule does not work, then 1 of the 2 will always execute each build. Instead add a new (unused) purgatory.chk intermediate which gets linked from purgatory.ro without -r to do the missing symbols check - This also fixes the check generating an a.out file (oops) Relevant part of the cover letter from v1: In 5.4-rc1 the 2 different sha256 implementations for the purgatory resp. for crypto/sha256_generic.c have been consolidated into 1 single shared implementation under lib/crypto/sha256.c . At least on x86 this was causing silent corruption of the purgatory due to a missing memzero_explicit symbol in the purgatory string.c/.o file. With the x86 equivalent of this patch applied a x86 build of 5.4-rc1 now correctly fails: CHK arch/x86/purgatory/purgatory.ro ld: arch/x86/purgatory/purgatory.ro: in function `sha256_transform': sha256.c:(.text+0x1c0c): undefined reference to `memzero_explicit' make[2]: *** [arch/x86/purgatory/Makefile:72: arch/x86/purgatory/kexec-purgatory.c] Error 1 make[1]: *** [scripts/Makefile.build:509: arch/x86/purgatory] Error 2 make: *** [Makefile:1650: arch/x86] Error 2 It would be great if the s390 maintainers can test this equivalent patch on s390. As for fixing the missing memzero_explicit symbol, we are currently discussing making memzero_explicit a static inline wrapper of memset in string.h, so that we do not need to implement it in multiple places. This discussion is Cc-ed to the generic linux-kernel@vger.kernel.org list, it is happening in the "[PATCH v2 5.4 regression fix] x86/boot: Provide memzero_explicit" thread. Regards, Hans