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From: Kees Cook <keescook@chromium.org>
To: "Maciej W. Rozycki" <macro@orcam.me.uk>,
	James Jones <linux@theinnocuous.com>
Cc: bp@alien8.de, x86@kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] x86: Remove a.out support
Date: Sat, 02 Apr 2022 19:24:26 -0700	[thread overview]
Message-ID: <67CF27C5-5013-4EF4-B24C-8D9EB52536FB@chromium.org> (raw)
In-Reply-To: <alpine.DEB.2.21.2204022255430.47162@angie.orcam.me.uk>



On April 2, 2022 3:14:43 PM PDT, "Maciej W. Rozycki" <macro@orcam.me.uk> wrote:
>On Wed, 16 Mar 2022, James Jones wrote:
>
>> Probably getting a bit off topic, but I did spend a few hours searching
>> around for any existing tools to convert a binary from a.out->ELF, and
>> trying to come up with something myself by extracting the sections with
>> objdump and re-combining them into an ELF using a linker script placing
>> the sections at the same locations. I couldn't get it working in an
>> evening or two messing with it so I moved on, but I agree something like
>> this seems possible in theory.
>
> Chiming in late as I'm scanning outstanding mailing list traffic: if this 
>is as you say all statically linked stuff, then converting from a.out to 
>ELF might be as easy as:
>
>$ objcopy -I a.out-i386-linux -O elf32-i386 a.out-binary elf-binary

Based on my research (and the wrapper I ended up writing), I don't think this is sufficient because entry point handling is different between ELF and a.out (specifically the stack layout and initial sp register value).

-Kees

-- 
Kees Cook

  reply	other threads:[~2022-04-03  2:24 UTC|newest]

Thread overview: 44+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-03-12 17:54 [PATCH] x86: Remove a.out support James Jones
2022-03-12 18:06 ` James Jones
2022-03-13 11:56   ` Borislav Petkov
2022-03-13 18:26     ` James Jones
2022-03-15  9:44       ` Borislav Petkov
2022-03-15 19:51   ` Kees Cook
2022-03-16  5:06     ` James Jones
2022-03-16 12:38       ` Arnd Bergmann
2022-03-16 22:30         ` Kees Cook
2022-03-17  2:04           ` James Jones
2022-03-17  2:08             ` David Laight
2022-03-17 10:17             ` Borislav Petkov
2022-03-17 18:53             ` Kees Cook
2022-03-17  2:32           ` David Laight
2022-03-17  3:22             ` Kees Cook
2022-03-16 16:10       ` Kees Cook
2022-03-16 17:05         ` David Laight
2022-04-02 22:14       ` Maciej W. Rozycki
2022-04-03  2:24         ` Kees Cook [this message]
2022-04-04 11:03           ` Maciej W. Rozycki
2022-04-04 17:07             ` David Laight
2022-04-04 18:18               ` Kees Cook
2022-04-04  8:24         ` Geert Uytterhoeven
  -- strict thread matches above, loose matches on Subject: below --
2022-01-13 16:01 Borislav Petkov
2022-01-13 18:08 ` Kees Cook
2022-01-13 18:47 ` Theodore Ts'o
2022-01-13 22:56   ` Borislav Petkov
2022-01-14  4:06     ` Theodore Ts'o
2022-01-14 10:40       ` Arnd Bergmann
2022-01-14 19:09       ` Borislav Petkov
2022-01-14  9:51     ` David Laight
2022-01-14 14:52     ` Geert Uytterhoeven
2022-01-14 18:57       ` Theodore Ts'o
2022-01-14 19:00         ` Geert Uytterhoeven
2022-01-14 19:12       ` Borislav Petkov
2022-01-14 19:21         ` Geert Uytterhoeven
2022-01-14 19:35           ` Borislav Petkov
2022-01-15 11:37             ` Borislav Petkov
2022-01-15 19:42               ` John Paul Adrian Glaubitz
2022-03-09 20:03                 ` [PATCH] a.out: Stop building a.out/osf1 support on alpha and m68k Eric W. Biederman
2022-03-09 22:04                   ` Kees Cook
2022-03-10 23:29                     ` [PATCH] x86: Remove a.out support Eric W. Biederman
2022-03-10 23:35                       ` Linus Torvalds
2022-03-11  8:47                         ` Arnd Bergmann
2022-03-11 10:03                       ` Borislav Petkov
2022-01-15  4:54           ` David Laight

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