Messages in this thread Patch in this message | | | Date | Tue, 27 May 2008 00:19:32 +0200 (CEST) | From | Jiri Kosina <> | Subject | Re: m68k libc5 regression |
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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@suse.cz> > 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):
From: Jiri Kosina <jkosina@suse.cz>
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@suse.cz>
diff --git a/mm/mmap.c b/mm/mmap.c index fac6633..834118b 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -245,10 +245,16 @@ asmlinkage unsigned long sys_brk(unsigned long brk) unsigned long rlim, retval; unsigned long newbrk, oldbrk; struct mm_struct *mm = current->mm; + unsigned long min_brk; down_write(&mm->mmap_sem); - if (brk < mm->start_brk) +#ifdef CONFIG_COMPAT_BRK + min_brk = mm->end_code; +#else + min_brk = mm->start_brk; +#endif + if (brk < min_brk) goto out; /*
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