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Old 06-20-2012, 01:21 PM
Dave Anderson
 
Default Pages excluded in dump RHEL 6.2 - set to ffffffffffffffff

----- Original Message -----
> I have a dump from RHEL 6.2 with all these masks set to all f's, so
> obviously crash excludes them.
>
> crash: page excluded: kernel virtual address: ffffffffffffffff type: "possible"
> WARNING: cannot read cpu_possible_map
> crash: page excluded: kernel virtual address: ffffffffffffffff type: "present"
> WARNING: cannot read cpu_present_map
> crash: page excluded: kernel virtual address: ffffffffffffffff type: "online"
> WARNING: cannot read cpu_online_map
>
> typedef struct cpumask { DECLARE_BITMAP(bits, NR_CPUS); } cpumask_t;
>
> #ifndef CONFIG_DISABLE_OBSOLETE_CPUMASK_FUNCTIONS
> /* These strip const, as traditionally they weren't const. */
> #define cpu_possible_map (*(cpumask_t *)cpu_possible_mask)
> #define cpu_online_map (*(cpumask_t *)cpu_online_mask)
> #define cpu_present_map (*(cpumask_t *)cpu_present_mask)
> #define cpu_active_map (*(cpumask_t *)cpu_active_mask)
>
> Are these deprecated now and is that why they are fixed at all f's.

No, that's just a common error message for accessing the maps or masks.

When reading them, crash checks first whether there is the older kernel symbol
named "cpu_xxx_map", and if it doesn't exists, then it checks for the symbol
named "cpu_xxx_mask". It then tried to read the memory that those symbols
point to, which all contained values of ffffffffffffffff. So clearly
there's some kind of mis-match between the symbol values -- modified by
using a System.map file -- and what's in the vmcore file.

(FWIW, the dumpfile couldn't find the page for bogus address, and presumed
that it was "excluded" since it's a filtered dump, so that's a non-issue...)

First question: it appears that you are analyzing a RHEL6 kernel, so why are
you using a "System.map" argument? Did you rebuild the kernel but when you
did that, you didn't save the rebuilt vmlinux file?

Dave

>
> [root@centos62 crash]# crash System.map vmlinux va102.2012-06-14.vmcore
>
> crash 6.0.7
> Copyright (C) 2002-2012 Red Hat, Inc.
> Copyright (C) 2004, 2005, 2006, 2010 IBM Corporation
> Copyright (C) 1999-2006 Hewlett-Packard Co
> Copyright (C) 2005, 2006, 2011, 2012 Fujitsu Limited
> Copyright (C) 2006, 2007 VA Linux Systems Japan K.K.
> Copyright (C) 2005, 2011 NEC Corporation
> Copyright (C) 1999, 2002, 2007 Silicon Graphics, Inc.
> Copyright (C) 1999, 2000, 2001, 2002 Mission Critical Linux, Inc.
> This program is free software, covered by the GNU General Public License,
> and you are welcome to change it and/or distribute copies of it under
> certain conditions. Enter "help copying" to see the conditions.
> This program has absolutely no warranty. Enter "help warranty" for
> details.
>
> GNU gdb (GDB) 7.3.1
> Copyright (C) 2011 Free Software Foundation, Inc.
> License GPLv3+: GNU GPL version 3 or later
> <http://gnu.org/licenses/gpl.html>
> This is free software: you are free to change and redistribute it.
> There is NO WARRANTY, to the extent permitted by law. Type "show copying"
> and "show warranty" for details.
> This GDB was configured as "x86_64-unknown-linux-gnu"...
>
> crash: page excluded: kernel virtual address: ffffffffffffffff type: "possible"
> WARNING: cannot read cpu_possible_map
> crash: page excluded: kernel virtual address: ffffffffffffffff type: "present"
> WARNING: cannot read cpu_present_map
> crash: page excluded: kernel virtual address: ffffffffffffffff type: "online"
> WARNING: cannot read cpu_online_map
> crash: page excluded: kernel virtual address: ffffffffffffffff type: "cpu_present_map"
> crash: page excluded: kernel virtual address: ffffffffffffffff type: "cpu_present_map"
> crash: page excluded: kernel virtual address: ffffffffffffffff type: "cpu_online_map"
> SYSTEM MAP: System.map
> DEBUG KERNEL: vmlinux (2.6.32-220.7.1.el6)
> DUMPFILE: va102.2012-06-14.vmcore [PARTIAL DUMP]
> CPUS: 32
> DATE: Thu Jun 14 05:24:17 2012
> UPTIME: 11:13:23
> LOAD AVERAGE: 215.00, 196.78, 135.81
> TASKS: 1778
> NODENAME: va1splunkindex02.va1.swtor.int
> RELEASE: 2.6.32-220.7.1.el6.x86_64
> VERSION: #1 SMP Tue Mar 6 13:54:51 EST 2012
> MACHINE: x86_64 (2799 Mhz)
> MEMORY: 48 GB
> PANIC: "Oops: 0002 [#1] SMP " (check log for details)
> PID: 2428
> COMMAND: "bash"
> TASK: ffff88063874ab40 [THREAD_INFO: ffff8806dcd1a000]
> CPU: 0
> STATE: TASK_RUNNING (PANIC)
>
> Thanks
> Laurence
>
> --
> Crash-utility mailing list
> Crash-utility@redhat.com
> https://www.redhat.com/mailman/listinfo/crash-utility
>

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