From: Andy Moreton <andrewjmoreton@gmail.com>
To: 33174@debbugs.gnu.org
Subject: bug#33174: 27.0.50; Dump fails on GNU/Linux ppc64le
Date: Mon, 12 Nov 2018 17:24:27 +0000 [thread overview]
Message-ID: <8636s68b04.fsf@gmail.com> (raw)
In-Reply-To: <m3lg6jekyi.fsf@fitzsim.org>
On Sun 11 Nov 2018, Paul Eggert wrote:
> Thomas Fitzsimmons wrote:
>> Actually, EMACS_HEAP_EXEC is true!
>
> OK, thanks, that explains things. I installed the first attached patch to the
> emacs-26 branch as a quick hack to work around the problem, and the second
> attached patch to the master branch to come up with a better way to address
> the underlying issue that doesn't involve fiddling with environment variables.
> Please let us know if this doesn't work for your platform, as I've tested this
> only on x86-64.
The second patch (applied to master) breaks the build on Windows.
> diff --git a/src/lisp.h b/src/lisp.h
> index eb6762678c..383d61274c 100644
> --- a/src/lisp.h
> +++ b/src/lisp.h
> @@ -4325,9 +4325,12 @@ struct tty_display_info;
>
> /* Defined in sysdep.c. */
> #ifdef HAVE_PERSONALITY_ADDR_NO_RANDOMIZE
> -extern bool disable_address_randomization (void);
> +extern int maybe_disable_address_randomization (bool, int, char **);
> #else
> -INLINE bool disable_address_randomization (void) { return false; }
> +INLINE void
> +maybe_disable_address_randomization (bool dumping, int argc, char **argv)
> +{
> +}
The return type must be consistent as it is used by its caller:
C:/emacs/git/emacs/master/src/emacs.c: In function 'main':
C:/emacs/git/emacs/master/src/emacs.c:709:8: error: void value not ignored as it ought to be
argc = maybe_disable_address_randomization (dumping, argc, argv);
^
The obvious fix seems to work:
#ifdef HAVE_PERSONALITY_ADDR_NO_RANDOMIZE
extern int maybe_disable_address_randomization (bool, int, char **);
#else
INLINE int
maybe_disable_address_randomization (bool dumping, int argc, char **argv)
{
return argc;
}
#endif
> +int
> +maybe_disable_address_randomization (bool dumping, int argc, char **argv)
> {
[snipped]
> + if (argc < 2 || strcmp (argv[1], aslr_disabled_option) != 0)
> + {
[snipped]
> + }
> + else
> + {
> + /* Our earlier incarnation already disabled ASLR. */
> + argc--;
> + memmove (&argv[1], &argv[2], argc * sizeof *argv);
> + }
This looks wrong: the memmove size is one element too long, and if argc
was 2 then there is an out of bounds access.
AndyM
next prev parent reply other threads:[~2018-11-12 17:24 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-27 10:35 bug#33174: 27.0.50; Dump fails on GNU/Linux ppc64le Thomas Fitzsimmons
2018-10-27 13:16 ` Thomas Fitzsimmons
2018-10-27 20:26 ` Paul Eggert
2018-10-28 8:05 ` Paul Eggert
2018-10-28 12:56 ` Thomas Fitzsimmons
2018-10-28 19:22 ` Paul Eggert
2018-10-30 1:28 ` Thomas Fitzsimmons
2018-10-30 2:16 ` Paul Eggert
2018-10-29 1:47 ` Thomas Fitzsimmons
2018-10-29 7:22 ` Paul Eggert
2018-10-30 2:44 ` Thomas Fitzsimmons
2018-10-30 5:58 ` Paul Eggert
2018-10-30 9:30 ` Thomas Fitzsimmons
2018-11-12 6:39 ` Paul Eggert
2018-11-12 17:24 ` Andy Moreton [this message]
2018-11-13 2:29 ` Thomas Fitzsimmons
2018-11-13 14:42 ` Paul Eggert
2018-11-19 3:14 ` Thomas Fitzsimmons
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