RE: [PATCH 1/2 v2] kdump: add the vmcoreinfo documentation

[Kazuhito Hagio]

-----Original Message-----
> > makedumpfile doesn't have any switch which dumps VMCOREINFO from kcore
> > for now. (I'm thinking to have makedumpfile dump it as debug message,
> > though.)
> 
> Might be useful as people are looking into using VMCOREINFO when
> debugging a live kernel...

Now makedumpfile in 'devel' branch can print VMCOREINFO in /proc/kcore
as debug message with the following command:

# ./makedumpfile --mem-usage /proc/kcore -D
...
VMCOREINFO   :
  OSRELEASE=4.20.0-0.rc2.git0.1.fc30.x86_64
  PAGESIZE=4096
page_size    : 4096
  SYMBOL(init_uts_ns)=ffffffff84213540
  ...

Also, it seems that recent crash utility in git repo with kernel 4.19
or newer can dump it with 'help -n' command:

# ./crash vmlinux /proc/kcore
...
crash> help -n
...
  Elf64_Nhdr:
      n_namesz: 11 ("VMCOREINFO")
      n_descsz: 1955
        n_type: 0 (unknown)

      OSRELEASE=4.20.0-0.rc2.git0.1.fc30.x86_64
      PAGESIZE=4096
      SYMBOL(init_uts_ns)=ffffffff84213540
      ...

Thanks,
Kazu