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Sender: Guenter Roeck <groeck7@gmail.com>
Date:   Mon, 23 May 2022 12:56:10 -0700
From:   Guenter Roeck <linux@roeck-us.net>
To:     Kees Cook <keescook@chromium.org>
Cc:     Alexander Popov <alex.popov@linux.com>,
        linux-hardening@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] gcc-plugins: Change all version strings match kernel
Message-ID: <20220523195610.GA3719222@roeck-us.net>
References: <20220510235412.3627034-1-keescook@chromium.org>
 <20220523143054.GA3164771@roeck-us.net>
 <202205231225.1CBACF63@keescook>
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On Mon, May 23, 2022 at 12:28:20PM -0700, Kees Cook wrote:
> On Mon, May 23, 2022 at 07:30:54AM -0700, Guenter Roeck wrote:
> > On Tue, May 10, 2022 at 04:54:12PM -0700, Kees Cook wrote:
> > > It's not meaningful for the GCC plugins to track their versions separately
> > > from the rest of the kernel. Switch all versions to the kernel version.
> > > 
> > > Fix mismatched indenting while we're at it.
> > > 
> > > Cc: linux-hardening@vger.kernel.org
> > > Signed-off-by: Kees Cook <keescook@chromium.org>
> > 
> > I see random build failures with this patch in linux-next.
> > 
> > Error log:
> > cc1plus: fatal error: ./include/generated/utsrelease.h: No such file or directory
> > 
> > The problem doesn't happen all the time. Is there some missing dependency ?
> 
> I've seen 0-day reports on this too and but I haven't been able to reproduce
> it. AFAICT, utsrelease.h should be generated before the gcc plugins are
> built, but clearly something is wrong.
> 
I have seen it only in my test builds, only on arm targets so far,
and I have been unable to reproduce it manually.

> > >  plugin_cxxflags	= -Wp,-MMD,$(depfile) $(KBUILD_HOSTCXXFLAGS) -fPIC \
> > >  		  -include $(srctree)/include/linux/compiler-version.h \
> > > +		  -include $(objtree)/include/generated/utsrelease.h \
> 
> I wonder if include/generated/utsrelease.h needs to be explicitly added
> as a build dep to the plugin logic?
> 
Looks like it, but I have no idea how to set that up or test/confirm it.

Guenter