linux-kernel - Re: [BUG] allmodconfig build error in next-20240108

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20240110095822.3ba3d979@canb.auug.org.au>
Date: Wed, 10 Jan 2024 09:58:22 +1100
From: Stephen Rothwell <sfr@...b.auug.org.au>
To: "Paul E. McKenney" <paulmck@...nel.org>
Cc: Lucas De Marchi <lucas.demarchi@...el.com>,
 linux-kernel@...r.kernel.org, intel-xe@...ts.freedesktop.org
Subject: Re: [BUG] allmodconfig build error in next-20240108

Hi all,

On Tue, 9 Jan 2024 14:45:56 -0800 "Paul E. McKenney" <paulmck@...nel.org> wrote:
>
> On Wed, Jan 10, 2024 at 08:11:55AM +1100, Stephen Rothwell wrote:
> > 
> > On Tue, 9 Jan 2024 10:58:40 -0600 Lucas De Marchi <lucas.demarchi@...elcom> wrote:  
> > >
> > > On Mon, Jan 08, 2024 at 03:15:23PM -0800, Paul E. McKenney wrote:  
> > > I could reproduce it with allmodconfig and gcc 11.4.1 from rockylinux,
> > > but not with gcc 9.3 or 12.3. Also it's not reproduced with gcc 11.4.1
> > > when using defconfig + CONFIG_DRM_XE  (even if  -Wstringop-overflow is
> > > still added).
> > > 
> > > I don't see a bug in the code, even if it inverts the head/tail
> > > convention.
> > > 
> > > Searching around showed this which may be relevant: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101854
> > > At least I can reproduce the same issue as in the snippet provided
> > > (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101854#c7) with the buggy
> > > compiler.
> > > 
> > > So, maybe the best thing to do for now is to disable -Wstringop-overflow
> > > for gcc < 12?
> > > 
> > > 
> > > ------8<-----
> > > diff --git a/drivers/gpu/drm/xe/Makefile b/drivers/gpu/drm/xe/Makefile
> > > index 6952da8979ea..0433a3c6cbfd 100644
> > > --- a/drivers/gpu/drm/xe/Makefile
> > > +++ b/drivers/gpu/drm/xe/Makefile
> > > @@ -17,7 +17,7 @@ subdir-ccflags-y += $(call cc-option, -Wunused-const-variable)
> > >   subdir-ccflags-y += $(call cc-option, -Wpacked-not-aligned)
> > >   subdir-ccflags-y += $(call cc-option, -Wformat-overflow)
> > >   subdir-ccflags-y += $(call cc-option, -Wformat-truncation)
> > > -subdir-ccflags-y += $(call cc-option, -Wstringop-overflow)
> > > +subdir-ccflags-$(call gcc-min-version, 120000) += $(call cc-option, -Wstringop-overflow)
> > >   subdir-ccflags-y += $(call cc-option, -Wstringop-truncation)
> > >   # The following turn off the warnings enabled by -Wextra
> > >   ifeq ($(findstring 2, $(KBUILD_EXTRA_WARN)),)
> > > ------8<-----  
> 
> This I did, thank you!

Maybe that line "subdir-ccflags-y += $(call cc-option, -Wstringop-overflow)"
should just be removed as the setting of that option has been moved to the
normal C flags in the top level Makefile (out of Makefile.extrawarn).

-- 
Cheers,
Stephen Rothwell

Content of type "application/pgp-signature" skipped