[Crash-utility] [PATCH] add a new command: ipcs

[Dave Anderson]

----- Original Message -----
> Hello Dave,
> 
> I have modified the output of ipcs, please see the attachment. About the
> bugs of SLES, I tried to install a SLES9(2.6.5-7.97-smp) to locate the
> problems. But I failed to get debuginfo. I will continue searching it.
> It will be helpful, if you have some information about it.

I believe that SLES9 kernels containing debuginfo data are built *after* the
original distribution's non-debuginfo kernels are built.  Therefore, they may 
have slight differences in their symbol values, so the correct System.map file
needs to be added to the crash command line.

I only have one sample SLES9 kernel (which I believe was modified by a 3rd party),
and it is invoked like this:

 $ crash vmlinux-2.6.5-7.315-smp.debug System.map-2.6.5-7.315-smp ap17.1234028168.dmp

So as I understand it:

(1) the original kernel was vmlinux-2.6.5-7.315-smp 
(2) the vmlinux-2.6.5-7.315-smp.debug kernel was built later 
(3) the original System.map-2.6.5-7.315-smp file is required to deal with symbol
    value differences between the two kernels.

I presume that what you need is a "vmlinux-2.6.5-7.97-smp.debug" kernel.  But I
don't know where they can be found -- even google cannot find one.

Perhaps you can download the 2.6.5-era kernel sources and check them against
your support for the RHEL4 2.6.9-era sources?  It's probably something fairly
minor.

As far as this version of ipcs.c goes, the only issues I have are display problems.

For some reason, if none of the facilities are being used, I see this output 
on RHEL4 and RHEL5 kernels:
 
 crash> ipcs
 SHMID_KERNEL     KEY      SHMID      UID   PERMS BYTES      NATTCH STATUS
 (none allocated)SEM_ARRAY        KEY      SEMID      UID   PERMS NSEMS     
 (none allocated)MSG_QUEUE        KEY      MSQID      UID   PERMS USED-BYTES   MESSAGES    
 (none allocated)
 crash> ipcs -mqs
 SHMID_KERNEL     KEY      SHMID      UID   PERMS BYTES      NATTCH STATUS
 (none allocated)SEM_ARRAY        KEY      SEMID      UID   PERMS NSEMS     
 (none allocated)MSG_QUEUE        KEY      MSQID      UID   PERMS USED-BYTES   MESSAGES    
 (none allocated)
 crash>
 
On kernels that are later than 2.6.18, the output is correct, for example on
this 2.6.24 kernel:

 crash> ipcs
 SHMID_KERNEL     KEY      SHMID      UID   PERMS BYTES      NATTCH STATUS
 (none allocated)
 
 SEM_ARRAY        KEY      SEMID      UID   PERMS NSEMS     
 (none allocated)
 
 MSG_QUEUE        KEY      MSQID      UID   PERMS USED-BYTES   MESSAGES    
 (none allocated)
 
 crash>
 
And on all kernels, the SHMID_KERNEL header is missing from "ipcs -M" if no shared
memory is used:

 crash> ipcs -M
 (none allocated)
 crash>

Lastly, the help page data needs work:  

(1) It still shows the output with the "------ Shared Memory Segments ------", 
    etc., strings.
(2) It still shows the "0x" in the KEY values.
(3) The "ipcs -M" example shows error output.  None of the crash help page examples
    show a command being used incorrectly, so please just show it working correctly:

    display specified resources in detail with an address
  
      crash> ipcs -M 1 ffff880473a28250 2
      invalid id or address: 1
      
      invalid id or address: 2
      
      SHMID_KERNEL     KEY      SHMID      UID   PERMS BYTES      NATTCH STATUS
      ffff880473a28250 00000002 65538      0     666   90000      1       
      PAGES ALLOCATED: 96 RESIDENT: 22 SWAPPED: 0
      SWAP PERFORMANCE ATTEMPTS: 0 SUCCESSES: 0
      VFS_INODE: ffff880470503758

Thanks,
  Dave