Re: [Patch] Elf loader crash while zero-filling .bss

From: Sam Ravnborg
Date: Mon Feb 11 2008 - 13:53:45 EST


On Mon, Feb 11, 2008 at 07:27:35PM +0100, Abel Bernabeu wrote:
> I've finally found a solution for the crash in load_binary_elf I
> reported last week:
>
> http://lkml.org/lkml/2008/1/30/171
>
> The attached patch solves my problem, but please test it yourself...
>
> set_brk(start, end) allocs just page aligned regions (by "colapsing"
> both extremes to the start of the page in which they lay)... That
> means than even if both pointers are not equal there are still some
> chances that set_brk has allocated no space at all because
> ELF_PAGEALIGN(elf_bss) != ELF_PAGEALIGN(elf_brk).

What architecture was this?
Most architectures align .bss properly but it seems arm does not
and I guess this is needed.

As .bss was empty? in your case you did not trigger
any alignmnet by linker due to largest member in section => boom.

I do think your patch paper over the real bug.

Sam
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