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Date:   Mon, 23 May 2022 12:28:20 -0700
From:   Kees Cook <keescook@chromium.org>
To:     Guenter Roeck <linux@roeck-us.net>
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: <202205231225.1CBACF63@keescook>
References: <20220510235412.3627034-1-keescook@chromium.org>
 <20220523143054.GA3164771@roeck-us.net>
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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.

> >  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?

-- 
Kees Cook