makedumpfile: Add erased information in compressed kdump file and ELF formatted dumpfile

[Mahesh Jagannath Salgaonkar]

On 09/12/2011 11:54 PM, Dave Anderson wrote:
> 
> Hi Mahesh,
> 
> Now that this feature is in makedumpfile-1.4.0, I presume that you
> have crash utility "warning" patches underway?

Yup. I am working on it, will post the patches very soon.

> 
> Also, can you confirm that compressed or kdumps with (or without)
> eraseinfo data can still be handled with no problem by the current
> version of the crash utility?  I'm not talking about the ramifications
> of whatever kernel data may have been erased, but whether the changes to
> the dumpfile headers could cause a problem.  I'm presuming that the
> compressed kdump eraseinfo data would be invisible to an older version
> of crash, and that ELF kdump eraseinfo would just show up as an (unused)
> ELF note -- but I just want to make sure. 

Yes. The changes to dumpfile header and addition of eraseinfo data/ELF
note will not cause any problems with older crash version. With the
current version of crash the ELF kdump eraseinfo note would show up as
below:

Elf64_Nhdr:
               n_namesz: 10 ("ERASEINFO")
               n_descsz: 56
                 n_type: 0 (?)
                         2065736172650000 72616a5f64657263
                         697320656d616e2e 650a36353220657a
                         656e692065736172 736f746f72705f74
                         303120657a697320

Thanks,
-Mahesh.