Re: [RESEND][mmotm][PATCH v2, 0/5] elf coredump: Add extended numbering support

Daisuke HATAYAMA
2010-01-13T08:57:13Z

From: Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [RESEND][mmotm][PATCH v2, 0/5] elf coredump: Add extended numbering support
Date: Mon, 11 Jan 2010 19:24:18 -0800

> On Tue, 12 Jan 2010 12:12:32 +0900 (JST) Daisuke HATAYAMA <d.hatayama@jp.fujitsu.com> wrote:
>
>> From: Andrew Morton <akpm@linux-foundation.org>
>> Subject: Re: [RESEND][mmotm][PATCH v2, 0/5] elf coredump: Add extended numbering support
>> Date: Thu, 7 Jan 2010 16:29:28 -0800
>>
>> > On Mon, 04 Jan 2010 10:06:07 +0900 (JST)
>> > Daisuke HATAYAMA <d.hatayama@jp.fujitsu.com> wrote:
>> >
>> > > The current ELF dumper can produce broken corefiles if program headers
>> > > exceed 65535. In particular, the program in 64-bit environment often
>> > > demands more than 65535 mmaps. If you google max_map_count, then you
>> > > can find many users facing this problem.
>> > >
>> > > Solaris has already dealt with this issue, and other OSes have also
>> > > adopted the same method as in Solaris. Currently, Sun's document and
>> > > AMD 64 ABI include the description for the extension, where they call
>> > > the extension Extended Numbering. See Reference for further information.
>> > >
>> > > I believe that linux kernel should adopt the same way as they did, so
>> > > I've written this patch.
>> > >
>> > > I am also preparing for patches of GDB and binutils.
>> >
>> > That's a beautifully presented patchset. Thanks for doing all that
>> > work - it helps.
>> >
>> > UML maintenance appears to have ceased in recent times, so if we wish
>> > to have these changes runtime tested (we should) then I think it would
>> > be best if you could find someone to do that please.
>> >
>> > And no akpm code-review would be complete without: dump_seek() is
>> > waaaay to large to be inlined. Is there some common .c file to where
>> > we could move it?
>> >
>>
>> * Patch Test for UML-i386
>>
>> I tested on UML-i386 for the stable release of that time, precisely
>> 2.6.32, since even building process for UML-i386 failed for mainline
>> and mmotm trees, as you've expected.
>>
>> I don't know internal UML implementation at all, so I need to find
>> someone if runtime test for mmotm tree is absolutely necessary.
>
> OK, thanks.
>

I'd like to correct the above.

UML-i386 can successfully be built and run by using default config
file for v2.6.32.11, v2.6.33-rc3 and current git mmotm tree,
respectively.

I have yet to do build test by allmodconfig.

Thanks.