[Crash-utility] kmap

[Dave Anderson]

----- "Darrin Thompson" <darrinth at gmail.com> wrote:

> On Wed, Nov 18, 2009 at 3:21 PM, Dave Anderson <anderson at redhat.com>
> wrote:
> > Or for what it's worth, you can just read the data using the
> physical
> > address:
> >
> >  crash> rd -p 2b0000 10
> >            2b0000:  0100c70000080805 fff0db31fb000000  ............1...
> >            2b0010:  8b485500313e6b05 c931c03145302454  .k>1.UH.T$0E1.1.
> 
> That's exactly what I'm looking for.
> 
> When I'm looking at:
> 
> kmem -p ffff810104ffd258
>       PAGE        PHYSICAL      MAPPING       INDEX CNT FLAGS
> ffff810104ffd258 16da9d000                0        0  1 168100000000061
> 
> How do I get the translation of the flags? I've seen something useful
> in vtop but I can never tell if it's giving me flags for the page
> struct at the pointer I give or the page struct that would have
> pointed the address I gave.

The flags you see in the "vtop" output are PTE flags and not page flags.

For the page flags, you'll have to look at the kernel source code
in "include/linux/page-flags.h".  The usage of that bit-field changes
way too much for it to be hardwired into the crash utility. 

Dave