[PATCH V2] kexec, x86: fix kexec when boot_params.hardware_subarch != 0

[Simon Horman]

On Tue, Mar 29, 2011 at 09:04:53AM +0000, WANG Cong wrote:
> On Mon, 28 Mar 2011 14:50:11 -0700, Chris Leech wrote:
> 
> > kexec needs to keep the subarch setting the same as the running kernel
> > in the boot parameters, or the kernel will die in early setup.  I ran
> > into this with X86_SUBARCH_MRST, but it should apply to CE4100 and any
> > future subarch that uses non-default early setup code.
> > 
> > This patch requires debugfs mounted at /sys/kernel/debug, as that's the
> > only way I know of to get at the running kernels boot_params. Without
> > debugfs mounted it falls back to the current behavior of assuming
> > subarch 0.
> > 
> ...
> >  
> > +#define BOOT_PARAMS_DBGFS	"/sys/kernel/debug/boot_params/data"
> 
> A minor issue here is that you are using a hard-coded debugfs path,
> debugfs can be also mounted to /debug too, so it is better that if we can 
> search the path dynamically here.

Do you think it would be better for the code to loop through
a few common alternatives for the path?