From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Wed, 9 Oct 2019 11:39:17 +0200 From: Philipp Rudo Subject: Re: [RFC v2 0/1] s390/purgatory: Make sure we fail the build if purgatory has missing symbols In-Reply-To: <20191008085421.11011-1-hdegoede@redhat.com> References: <20191008085421.11011-1-hdegoede@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Message-Id: <20191009113917.47ef6eda@laptop-ibm> Sender: linux-kernel-owner@vger.kernel.org List-ID: To: Hans de Goede Cc: Heiko Carstens , Vasily Gorbik , Christian Borntraeger , Arvind Sankar , Nathan Chancellor , linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, Ingo Molnar Hi Hans, also adding Ingo on Cc. I tested you patch on s390 and it does what it's supposed to do. The build now fails with LD arch/s390/purgatory/purgatory.chk arch/s390/purgatory/purgatory: In function `sha256_update': (.text+0x3bc2): undefined reference to `memzero_explicit' /home/prudo/git/linux/linux/arch/s390/purgatory/Makefile:38: recipe for target 'arch/s390/purgatory/purgatory.chk' failed make[3]: *** [arch/s390/purgatory/purgatory.chk] Error 1 After applying Arvid's memzero_explizit fix ("[PATCH] lib/string: make memzero_explicit inline instead of external") as well the build works again. My only problem is how to uptream your patch. Just adding it to our branch would cause a (intentional) build breakage until Ingo's branch is merged. @Vasliy & Ingo: Can you please find a solution for this. Thanks Philipp On Tue, 8 Oct 2019 10:54:20 +0200[PATCH] lib/string: make memzero_explicit inline instead of external Hans de Goede wrote: > 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 > > >