Re: [PATCH] x86/boot/KASLR: skip the specified crashkernel reserved region

[Baoquan He]

On 02/25/19 at 10:45am, Borislav Petkov wrote:
> On Mon, Feb 25, 2019 at 03:59:56PM +0800, Pingfan Liu wrote:
> > crashkernel=x@y option may fail to reserve the required memory region if
> > KASLR puts kernel into the region. To avoid this uncertainty, making KASLR
> > skip the required region.
> 
> Lemme see if I understand this correctly: supplying crashkernel=X@Y
> influences where KASLR would put the randomized kernel. And it should be
> the other way around, IMHO. crashkernel= will have to "work" with KASLR
> to find a suitable range and if the reservation at Y fails, then we tell
> the user to try the more relaxed variant crashkernel=M.

Hmm, asking user to try crashkernel=M is an option. Users may want to
specify a region for crashkernel reservation, Just I forget in what case
they want crashkernel=x@y set. In crashkernel=x@y specified case, we may
truly need to avoid the already specified region.

Not sure if Dave still remember it. If no need, removing it is also
good.

Thanks
Baoquan