linux-kernel - Question: elf coredump with an extreme program

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Message-Id: <20090611161553.3b1fcc8b.kamezawa.hiroyu@jp.fujitsu.com>
Date:	Thu, 11 Jun 2009 16:15:53 +0900
From:	KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>
To:	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Question: elf coredump with an extreme program

Hi, 

At first, I don't have any real problem, now. just curious....

Now, sysctl_max_map_count=65536 at default.

And some (silly) program  and increases max_map_count to be very large to
do mmap() more.

Unfortunately, it gets SEGV and  generates a core-dump.
But this core is not readable by gdb.

Because it seems ELF format uses 16bit value for # of sections,
coredump header is corrupted in this case. (secions are crated per
vma.)

gdb shouldn't trust the number of sections in  elf->e_phnum ?
or is there some workaround technique for this problem ?

BTW, I think default limit of 65536 of vma is too large for usual ELF program.
coredump will be corrupted.

Thanks,
-Kame

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