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From:   Arvind Sankar <nivedita@alum.mit.edu>
Date:   Fri, 21 Aug 2020 17:28:28 -0400
To:     Kees Cook <keescook@chromium.org>
Cc:     Arvind Sankar <nivedita@alum.mit.edu>,
        Ingo Molnar <mingo@kernel.org>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Mark Rutland <mark.rutland@arm.com>,
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        James Morse <james.morse@arm.com>,
        Borislav Petkov <bp@suse.de>, Ingo Molnar <mingo@redhat.com>,
        Russell King <linux@armlinux.org.uk>,
        Masahiro Yamada <masahiroy@kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Nathan Chancellor <natechancellor@gmail.com>,
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        linux-efi@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH v6 27/29] x86/boot/compressed: Remove, discard, or assert
 for unwanted sections
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 <202008211421.47347CA42@keescook>
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On Fri, Aug 21, 2020 at 02:21:34PM -0700, Kees Cook wrote:
> On Fri, Aug 21, 2020 at 04:01:59PM -0400, Arvind Sankar wrote:
> > On Fri, Aug 21, 2020 at 12:43:08PM -0700, Kees Cook wrote:
> > > In preparation for warning on orphan sections, stop the linker from
> > > generating the .eh_frame* sections, discard unwanted non-zero-sized
> > > generated sections, and enforce other expected-to-be-zero-sized sections
> > > (since discarding them might hide problems with them suddenly gaining
> > > unexpected entries).
> > > 
> > > Signed-off-by: Kees Cook <keescook@chromium.org>
> > >  	.rel.dyn : {
> > > -		*(.rel.*)
> > > +		*(.rel.*) *(.rel_*)
> > >  	}
> > >  	ASSERT(SIZEOF(.rel.dyn) == 0, "Unexpected run-time relocations (.rel) detected!")
> > >  
> > >  	.rela.dyn : {
> > > -		*(.rela.*)
> > > +		*(.rela.*) *(.rela_*)
> > >  	}
> > >  	ASSERT(SIZEOF(.rela.dyn) == 0, "Unexpected run-time relocations (.rela) detected!")
> > >  }
> > > -- 
> > > 2.25.1
> > > 
> > 
> > When do you get .rela_?
> 
> i386 builds, IIRC. I can try to hunt that down if you want?
> 
> -- 
> Kees Cook

Nah, just curious.

Thanks.