Re: m68k libc5 regression

From: Geert Uytterhoeven
Date: Thu May 29 2008 - 15:39:38 EST


On Tue, 27 May 2008, Jiri Kosina wrote:
> On Mon, 26 May 2008, Geert Uytterhoeven wrote:
>
> > Recently I noticed a regression when running an old libc5 binary
> > (amiga-lilo) on m68k. It fails with the error message:
>
> Hmm, libc5 is known to make broken assumptions about brk location, that's
> why we introduced CONFIG_COMPAT_BRK, do you have that option turned on?
>
> > So I bisected it to:
> > commit 4cc6028d4040f95cdb590a87db478b42b8be0508
> > Author: Jiri Kosina <jkosina@xxxxxxx>
> > Date: Wed Feb 6 22:39:44 2008 +0100
> > brk: check the lower bound properly
>
> Indeed, this should take CONFIG_COMPAT_BRK into account. Does the patch
> below fix it? (assuming that you have CONFIG_COMPAT_BRK=y):

Yes, both libc5 amiga-lilo and the libc5 emergency ramdisk work again
after applying this patch.

> From: Jiri Kosina <jkosina@xxxxxxx>
>
> brk: check lower bound properly
>
> The check in sys_brk() on minimum value the brk might have must take
> CONFIG_COMPAT_BRK setting into account. When this option is turned on
> (i.e. we support ancient legacy binaries, e.g. libc5-linked stuff), the
> lower bound on brk value is mm->end_code, otherwise the brk start is
> allowed to be arbitrarily shifted.
>
> Signed-off-by: Jiri Kosina <jkosina@xxxxxxx>

Acked-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
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