crash on F20 beta says log_buf data structure has changed

[Dave Anderson]

----- Original Message -----
> Hi Dave,
> 
> I captured a crash of F20 beta system and opened vmcore. crash gives me
> warning that log_buf has changed and "log" command does not output
> anything.
> 
> I thought you fixed it. Is it just a problem of pushing crash update
> to F20?

I did, but as part of it, there's also this check for further changes:

                /*
                 * If things change, don't kill a dumpfile session
                 * searching for a panic message.
                 */
                if (INVALID_SIZE(log) ||
                    INVALID_MEMBER(log_ts_nsec) ||
                    INVALID_MEMBER(log_len) ||
                    INVALID_MEMBER(log_text_len) ||
                    INVALID_MEMBER(log_dict_len) ||
                    (INVALID_MEMBER(log_level) && INVALID_MEMBER(log_flags_level)) ||
                    !kernel_symbol_exists("log_buf_len") ||
                    !kernel_symbol_exists("log_buf")) {
                        error(WARNING, "\nlog buf data structure(s) have changed\n");
                        return;
                }
 
Is the system still available, or do you have a vmcore from that kernel?

Dave



> Thanks
> Vivek
> 
> # crash /usr/lib/debug/lib/modules/3.11.8-300.fc20.x86_64/vmlinux vmcore
> 
> crash 7.0.1-2.fc20
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> Copyright (C) 2005, 2011  NEC Corporation
> Copyright (C) 1999, 2002, 2007  Silicon Graphics, Inc.
> Copyright (C) 1999, 2000, 2001, 2002  Mission Critical Linux, Inc.
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>  
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> This GDB was configured as "x86_64-unknown-linux-gnu"...
> 
>       KERNEL: /usr/lib/debug/lib/modules/3.11.8-300.fc20.x86_64/vmlinux
>     DUMPFILE: vmcore  [PARTIAL DUMP]
>         CPUS: 4
>         DATE: Tue Nov 19 16:33:43 2013
>       UPTIME: 00:03:24
> LOAD AVERAGE: 0.18, 0.37, 0.18
>        TASKS: 172
>     NODENAME: <Edited>
>      RELEASE: 3.11.8-300.fc20.x86_64
>      VERSION: #1 SMP Wed Nov 13 16:34:27 UTC 2013
>      MACHINE: x86_64  (2333 Mhz)
>       MEMORY: 4 GB
>        PANIC:
> WARNING: log buf data structure(s) have changed
> ""
>          PID: 10584
>      COMMAND: "bash"
>         TASK: ffff8801371d96e0  [THREAD_INFO: ffff880138dd8000]
>          CPU: 3
>        STATE: TASK_RUNNING (PANIC)
> 
> crash> log
> 
> log: WARNING: log buf data structure(s) have changed
>