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From: "H.J. Lu" <hjl.tools@gmail.com>
To: Cary Coutant <ccoutant@gmail.com>
Cc: Generic System V Application Binary Interface
	<generic-abi@googlegroups.com>, Florian Weimer <fw@deneb.enyo.de>,
		gnu-gabi@sourceware.org
Subject: Re: RFC: Audit external function called indirectly via GOT
Date: Mon, 01 Jan 2018 00:00:00 -0000	[thread overview]
Message-ID: <CAMe9rOpeMrHNAc+2OdH-Oxo8fh+84++6Fm0H-oRdrzLAnUQqtA@mail.gmail.com> (raw)
In-Reply-To: <CAJimCsFNUMj8tDe5RcL6vv=B4ymga0OaPZnp=qJ-9CUEC3UTGA@mail.gmail.com>

On Thu, Mar 22, 2018 at 9:10 AM, Cary Coutant <ccoutant@gmail.com> wrote:
>> Today we have to admit that -fno-plt is not compatible with auditing.
>>
>> I would like to change that to ensure that in future releases we are
>> able to let users use -fno-plt *and* auditing.
>
> The security features are all about locking down the GOT and the
> PLTGOT at program startup. The auditing features take advantage of the
> lazy binding mechanism and want to fiddle with those tables
> dynamically. I don't see how you're going to make the two compatible.
>

That is exactly what my proposal does:

1.  Provide both GOT and PLTGOT without lazy binding.
2. PLTGOT is unused without LD_AUDIT.
3. With LD_AUDIT, ld.so redirects GLOB_DAT relocation against GOT to
JUMP_SLOT relocation against PLTGOT.  This is not the same as lazy
binding since it happens every time when a function is called, not just
the first time.

-- 
H.J.

  reply	other threads:[~2018-03-22 17:43 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-01-01  0:00 H.J. Lu
2018-01-01  0:00 ` Florian Weimer
2018-01-01  0:00   ` H.J. Lu
2018-01-01  0:00     ` Florian Weimer
2018-01-01  0:00       ` Carlos O'Donell
2018-01-01  0:00         ` Florian Weimer
2018-01-01  0:00           ` Carlos O'Donell
2018-01-01  0:00             ` Florian Weimer
2018-01-01  0:00               ` H.J. Lu
2018-01-01  0:00                 ` Florian Weimer
2018-01-01  0:00                   ` H.J. Lu
2018-01-01  0:00             ` H.J. Lu
2018-01-01  0:00               ` Carlos O'Donell
2018-01-01  0:00             ` Cary Coutant
2018-01-01  0:00               ` H.J. Lu [this message]
2018-01-01  0:00                 ` Cary Coutant
2018-01-01  0:00                   ` H.J. Lu
2018-01-01  0:00                     ` Cary Coutant
2018-01-01  0:00           ` H.J. Lu
2018-01-01  0:00     ` Florian Weimer
2018-01-01  0:00       ` H.J. Lu
2018-01-01  0:00         ` Florian Weimer
2018-01-01  0:00 ` Cary Coutant
2018-01-01  0:00   ` Carlos O'Donell
2018-01-01  0:00     ` Cary Coutant
2018-01-01  0:00       ` Alan Modra
2018-01-01  0:00         ` H.J. Lu
2018-01-01  0:00           ` Alan Modra
2018-01-01  0:00             ` H.J. Lu
2018-01-01  0:00       ` H.J. Lu
2018-01-01  0:00         ` Cary Coutant
2018-01-01  0:00           ` Cary Coutant
2018-01-01  0:00           ` H.J. Lu

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