On Wed, Jul 30, 2008 at 09:01:31AM -0400, Vivek Goyal wrote:
> On Tue, Jul 29, 2008 at 06:12:38PM +1000, Simon Horman wrote:
> > After recent changes setting elfcorehdr_addr to ELFCORE_ADDR_MAX
> > will cause is_kdump_kernel() to return 0 when it should return 1.
> > Instead use vmcore_unusable(), which has been added for this purpose.
> >
> > Signed-off-by: Simon Horman <horms at verge.net.au>
> >
> > Index: linux-2.6/arch/ia64/kernel/setup.c
> > ===================================================================
> > --- linux-2.6.orig/arch/ia64/kernel/setup.c 2008-07-29 17:27:43.000000000 +1000
> > +++ linux-2.6/arch/ia64/kernel/setup.c 2008-07-29 17:50:50.000000000 +1000
> > @@ -502,11 +502,11 @@ int __init reserve_elfcorehdr(unsigned l
> > * to work properly.
> > */
> >
> > - if (elfcorehdr_addr >= ELFCORE_ADDR_MAX)
> > + if (!is_vmcore_usable())
> > return -EINVAL;
> >
> > if ((length = vmcore_find_descriptor_size(elfcorehdr_addr)) == 0) {
> > - elfcorehdr_addr = ELFCORE_ADDR_MAX;
> > + vmcore_unusable();
> > return -EINVAL;
> > }
> >
>
> Hi Simon,
>
> I had a question. I am not very sure what reserve_elfcorehdr is doing
> but doing something similar to reserving some memory area where
> elfcoreheaders are.
Yes, that is my understanding of what it does.
> I see that reserve_elfcorehdr is under CONFIG_PROC_VMCORE. Will it work
> if CONFIG_PROC_VMCORE=n and somebody wants to use /dev/oldmem?
> Or reserve_elfcorehdr should be under CONFIG_CRASH_DUMP?
I'm not that familiar with /dev/oldmem, but as far as I can see,
read_oldmem doesn't do anything with ELF headers, so reservation
by vmcore_find_descriptor_size() should not be neccessary.
On a related note, I wonder if some consolitation of
read_oldmem() (used by /dev/oldmem) and read_from_oldmem()
(used by /proc/vmcore) can be done.
--
Horms
