One of the items in the bug list is the following: DESCRIPTION: User space enhancements: - show user space stack backtrace, if present in the dump file, - ability to link user space namelist (debug object files), RESOLUTION STATUS: TBD Is anyone currently working on this?

----- "James Bradshaw" <jbradsha(a)enterasys.com&gt; wrote: > Right. To be able to examine user space, you'd have to build an elf > core file by processing the desired task structure in the kdump file, > find all the user pages, etc.--essentially what elf_core_dump() does > in a running kernel. Then you could use gdb offline or the embedded > gdb. Yep, that would be pretty cool... "gdb offline" that is. I still don't think it makes sense to do anything on the user core file from the embedded gdb, given it's been wired/hacked to work solely as a crash utility slave. I envision a command that would work something like, for example, for PID 24677: crash> core 24677 core.24677 created crash> where 24677 is the PID. As a template for gathering the core data, the "vm -p" command shows you where all of the user pages are, and the "bt" kernel entry point gives you the "last-known" register set. Seems like it could work... > I understand your desire not to burden crash with user space stuff, > although the extensions facility seems to provide a mechanism for > cleanly excluding such functionality from the standard configuration. > Just a thought. Absolutely -- that's precisely what it's there for. But for that matter, after it's working nicely as an extension, and if it can be cleanly, reliably and maintainably (word?) moved into the base sources, I'm all for it. Thanks, Dave -- Crash-utility mailing list Crash-utility(a)redhat.com https://www.redhat.com/mailman/listinfo/crash-utility

There was a group at IBM (Stefan Schlosser <sschloss(a)de.ibm.com>) a few years ago which set up stuff to generate a elf corefile for a user space process for lcrash.

We ported it to crash as a loadable extension, but only did the i386 stuff. If there's enough interest we could see about liberating our internal code.

We ported it to crash as a loadable extension, but only did the i386 stuff. If there's enough interest we could see about liberating our internal code.

I don't really have resources to devote to merging my code, but I can probably send you what I have. Our system usually doesn't have the critical processes swapped at all, so it's not something that I've worried about. Seigo, it sounds like you're situation is similar to mine. As I said before, I can look into making sure it's ok to release our code. -castor -----Original Message----- From: crash-utility-bounces(a)redhat.com [mailto:crash-utility-bounces@redhat.com] On Behalf Of S.Iguchi Sent: Monday, December 08, 2008 1:26 AM To: crash-utility(a)redhat.com Cc: Castor Fu Subject: Re: [Crash-utility] user-space enhancements Hi, > We ported it to crash as a loadable extension, but only did the i386 > stuff. > > If there's enough interest we could see about liberating our internal > code. Cool. I also have such crash extention module works only on x86-64... and tested only with 2.6.10 and 2.6.20 . # crash -s vmlinux-2.6.20-1.2320.fc5 /mnt/fc5/var/crash/2008-01-28-18 \:17/vmcore : crash> extend elfcoredump.so elfcoredump.so: shared object loaded crash> elfdump 1 elfdump: write elfcore.1 done... crash> # gdb /sbin/init elfcore.1 : To enable dump shmem, add -s option . But unfortunately , the module is coredump_filter unaware. and has a lots TBD code . BTW, Oda-san mentioned page swapout case on another thread , in that case , I decided simply seek to next page (same as ZERO page case). sigh... i know its incorrect. I think this module contains incomplete functionality , but should be maintained in crash community . Castor, how about merge mine and your i386 module ? Thanks. Seigo Iguchi. From: "Castor Fu" <Castor.Fu(a)3PAR.com&gt; Subject: RE: [Crash-utility] user-space enhancements Date: Thu, 4 Dec 2008 14:06:29 -0800 > There was a group at IBM (Stefan Schlosser <sschloss(a)de.ibm.com>) > a few years ago which set up stuff to generate > a elf corefile for a user space process for lcrash. > > We ported it to crash as a loadable extension, but only did the i386 > stuff. > > If there's enough interest we could see about liberating our internal > code. > > -castor > > > > -----Original Message----- > From: crash-utility-bounces(a)redhat.com > [mailto:crash-utility-bounces@redhat.com] On Behalf Of Bradshaw, James > Sent: Thursday, December 04, 2008 12:58 PM > To: Discussion list for crash utility usage, maintenance and development > Subject: RE: [Crash-utility] user-space enhancements > > > Right. To be able to examine user space, you'd have to build an elf core > > file by processing the desired task structure in the kdump file, find > all > the user pages, etc.--essentially what elf_core_dump() does in a running > > kernel. Then you could use gdb offline or the embedded gdb. > > I understand your desire not to burden crash with user space stuff, > although the extensions facility seems to provide a mechanism for > cleanly > excluding such functionality from the standard configuration. Just a > thought. > > -----Original Message----- > From: crash-utility-bounces(a)redhat.com > [mailto:crash-utility-bounces@redhat.com] On Behalf Of Dave Anderson > Sent: Thursday, December 04, 2008 3:25 PM > To: Discussion list for crash utility usage, maintenance and development > Subject: Re: [Crash-utility] user-space enhancements > > > ----- "James Bradshaw" <jbradsha(a)enterasys.com&gt; wrote: > > > One of the items in the bug list is the following: > > > > DESCRIPTION: > > User space enhancements: > > - show user space stack backtrace, if present in the dump file, > > - ability to link user space namelist (debug object files), > > > > RESOLUTION STATUS: TBD > > > > Is anyone currently working on this? > > The items in the TODO list, with the exception of the first > one about the "search" command, are all essentially "wish-list" > items. They were originally requested to be put there by IBM > several years ago when the http://people.redhat.com/anderson > site was instantiated as the "upstream" source of the crash > utility. > > The only item that I'm aware of that somebody is actually looking > into is the one regarding "local variables", where I believe the > guy looking into it is part of the IBM LTC in India. I don't > expect much to come out of it, though, because for one thing > it presumes that the crash utility's backtrace frame information > is etched in stone -- and with the exception of ia64 which has > unwind information actually built into the kernel -- the backtrace > is essentially a "best-guess" operation. So trying to pull local > arguments (or function arguments for that matter) from a > dubious source doesn't make a whole lot of sense. > > As far as a user-space backtrace, I still think the way to go > is to work on creating a core dump file of the requested task, > and then use gdb externally on that core file, completely outside > of the crash utility. Trying to overload the crash utility with > a bunch of user-space stuff is something I don't have a lot of > interest in. > > Dave > > > > > > -- > Crash-utility mailing list > Crash-utility(a)redhat.com > https://www.redhat.com/mailman/listinfo/crash-utility > > > -- > Crash-utility mailing list > Crash-utility(a)redhat.com > https://www.redhat.com/mailman/listinfo/crash-utility > > > This email and any attachments thereto may contain private, confidential, and privileged material for the sole use of the intended recipient. Any review, copying, or distribution of this email (or any attachments) by others is strictly prohibited. If you are not the intended recipient, please contact the sender immediately and permanently delete the original and any copies of this email and any attachments thereto. > > -- > Crash-utility mailing list > Crash-utility(a)redhat.com > https://www.redhat.com/mailman/listinfo/crash-utility -- Crash-utility mailing list Crash-utility(a)redhat.com https://www.redhat.com/mailman/listinfo/crash-utility This email and any attachments thereto may contain private, confidential, and privileged material for the sole use of the intended recipient. Any review, copying, or distribution of this email (or any attachments) by others is strictly prohibited. If you are not the intended recipient, please contact the sender immediately and permanently delete the original and any copies of this email and any attachments thereto. -- Crash-utility mailing list Crash-utility(a)redhat.com https://www.redhat.com/mailman/listinfo/crash-utility