[PATCH v4 0/4] kexec-tools, x86: E820 memmap pass for kdump

Vivek Goyal vgoyal at redhat.com
Thu Mar 27 18:23:09 EDT 2014


On Thu, Mar 27, 2014 at 06:31:54PM +0800, WANG Chao wrote:
> Hi, Vivek
> 
> Sorry for my late response.
> 
> On 03/20/14 at 11:42am, Vivek Goyal wrote:
> > On Wed, Mar 19, 2014 at 04:03:57PM +0800, WANG Chao wrote:
> > > Hi, All
> > > 
> > > When kaslr comes in and kdump is broken, it seems about the right time to use
> > > E820 instead of memmap=exactmap to pass memmap for kdump for the default memmap
> > > passing mechanism:
> > > http://lists.infradead.org/pipermail/kexec/2014-February/011048.html
> > 
> > What's the connection between kaslr and passing memory mappings in
> > bootparams?
> 
> kaslr doesn't work with memmap=exactmap. kaslr happens before parsing
> user defined memmap and it walks through E820 in boot_params to
> determine 2nd kernel text area. And it would override the 1st kernel's
> ram.

Ok got it. I forgot about that kaslr is broken with memmap=exactmap. So
this patchset is mandatory for making kexec-tools work with kaslr.

Thanks
Vivek



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