From: Markus Gutschke <markus@google.com>
To: "Kawai, Hidehiro" <hidehiro.kawai.ez@hitachi.com>
Cc: Andrew Morton <akpm@osdl.org>,
kernel list <linux-kernel@vger.kernel.org>,
Pavel Machek <pavel@ucw.cz>, Robin Holt <holt@sgi.com>,
dhowells@redhat.com, Alan Cox <alan@lxorguk.ukuu.org.uk>,
Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>,
sugita <yumiko.sugita.yf@hitachi.com>,
Satoshi OSHIMA <soshima@redhat.com>
Subject: Re: [PATCH 0/4] coredump: core dump masking support v3
Date: Fri, 23 Feb 2007 19:32:23 -0800 [thread overview]
Message-ID: <45DFB1C7.1030205@google.com> (raw)
In-Reply-To: <45D5B2E3.3030607@hitachi.com>
Kawai, Hidehiro wrote:
> This patch series is version 3 of the core dump masking feature,
> which provides a per-process flag not to dump anonymous shared
> memory segments.
I just wanted to remind you that you need to be careful about dumping
the [vdso] segment no matter whether you omit other segments. I didn't
actually try running your patches, and if the kernel doesn't actually
consider this segment anonymous and shared, things might already work
fine as is.
In any case, you can check with "readelf -a", if the [vdso] segment is
there. And you will find that if you forget to dump it, "gdb" can no
longer give you stack traces on call chains that involve signal handlers.
As an alternative to your kernel patch, you could achieve the same goal
in user space, by linking my coredumper
http://code.google.com/p/google-coredumper/ into your binaries and
setting up appropriate signal handlers. An equivalent patch for
selectively omitting memory regions would be trivial to add. While this
does give you more flexibility, it of course has the drawback of
requiring you to change your applications, so there still is some
benefit in a kernelspace solution.
Markus
next prev parent reply other threads:[~2007-02-24 3:32 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-02-16 13:34 [PATCH 0/4] coredump: core dump masking support v3 Kawai, Hidehiro
2007-02-16 13:39 ` [PATCH 1/4] coredump: add an interface to control the core dump routine Kawai, Hidehiro
2007-02-16 13:40 ` [PATCH 2/4] coredump: ELF: enable to omit anonymous shared memory Kawai, Hidehiro
2007-02-16 13:41 ` [PATCH 3/4] coredump: ELF-FDPIC: " Kawai, Hidehiro
2007-02-16 13:42 ` [PATCH 4/4] coredump: documentation for proc entry Kawai, Hidehiro
2007-02-16 15:05 ` [PATCH 3/4] coredump: ELF-FDPIC: enable to omit anonymous shared memory David Howells
2007-02-16 16:50 ` Robin Holt
2007-02-16 20:09 ` David Howells
2007-03-02 16:55 ` Hugh Dickins
2007-03-03 14:10 ` David Howells
2007-03-05 19:04 ` Hugh Dickins
2007-03-06 18:13 ` David Howells
2007-03-09 14:12 ` Move to unshared VMAs in NOMMU mode? David Howells
2007-03-12 20:50 ` Robin Getz
2007-03-13 10:14 ` David Howells
2007-03-15 21:20 ` Hugh Dickins
2007-03-15 22:47 ` David Howells
2007-03-19 19:23 ` Eric W. Biederman
2007-03-20 11:06 ` David Howells
2007-03-20 16:48 ` Eric W. Biederman
2007-03-20 19:12 ` David Howells
2007-03-20 19:51 ` David Howells
2007-03-21 16:11 ` David Howells
2007-03-03 14:25 ` [PATCH] NOMMU: Hide vm_mm in NOMMU mode David Howells
2007-02-20 9:45 ` [PATCH 3/4] coredump: ELF-FDPIC: enable to omit anonymous shared memory Kawai, Hidehiro
2007-02-20 10:58 ` David Howells
2007-02-20 12:56 ` Robin Holt
2007-02-21 10:00 ` Kawai, Hidehiro
2007-02-21 11:33 ` David Howells
2007-02-21 11:54 ` Robin Holt
2007-02-22 5:33 ` Kawai, Hidehiro
2007-02-22 11:47 ` David Howells
2007-02-16 15:08 ` [PATCH 0/4] coredump: core dump masking support v3 David Howells
2007-02-20 9:48 ` Kawai, Hidehiro
2007-02-24 3:32 ` Markus Gutschke [this message]
2007-02-24 11:39 ` Pavel Machek
2007-03-01 12:35 ` Kawai, Hidehiro
2007-03-01 18:16 ` Markus Gutschke
2007-02-24 10:02 ` David Howells
2007-02-24 20:01 ` Markus Gutschke
2007-02-26 11:49 ` David Howells
2007-02-26 12:01 ` Pavel Machek
2007-02-26 12:42 ` David Howells
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