[PATCH] kexec: Add option to fallback to old kexec syscall when kexec file based syscall failed

[joeyli]

On Fri, Jul 15, 2016 at 09:58:22AM +0200, Petr Tesarik wrote:
> On Fri, 15 Jul 2016 07:57:22 +0800
> joeyli <jlee at suse.com> wrote:
> 
> > Hi Vivek
> > 
> > On Thu, Jul 14, 2016 at 10:53:28AM -0400, Vivek Goyal wrote:
> > > On Thu, Jul 14, 2016 at 04:45:11PM +0800, Lee, Chun-Yi wrote:
> > > > This patch adds a new "--fallback-kexec" option to give a chance to
> > > > fallback to old kexec syscall when file based kexec syscall operation
> > > > failed.
> > > 
> > > I think caller should switch to using different interface if need be. But
> > > I don't see much point in providing an option for this in kexec-tools.
> > > 
> > > Vivek
> > >
> > 
> > OK~ Understood!
> > 
> > Thanks for Baoquan's and your opinion for this patch.
> 
> Is there some sort of diagnostics, so a calling script can determine
> whether kexec failed, because there's no suppor for kexec_file_load(2)
> or for a different reason? 
> 
> Thanks,
> Petr T

The calling script needs to use "-s" option to access file based kexec, then
check the result and call kexec without -s to access old kexec syscall.

With this patch is just more convenience.


Thanks a lot!
Joey Lee