On Fri, Mar 16, 2007 at 08:52:30AM +0530, Vivek Goyal wrote: > On Fri, Mar 16, 2007 at 11:40:07AM +0900, Magnus Damm wrote: > > On 3/16/07, Horms <[EMAIL PROTECTED]> wrote: > > >On Thu, Mar 15, 2007 at 06:56:16PM +0530, Vivek Goyal wrote: > > >> On Thu, Mar 15, 2007 at 12:22:57PM +0000, Ian Campbell wrote: > > >> > On Thu, 2007-03-15 at 11:17 +0530, Vivek Goyal wrote: > > >> > > > > But I think changing this macro might run into issues. It is > > >> > > > > being used at few places in kernel, for example while loading > > >> > > > > module. This will essentially mean that we allow loading 64bit > > >> > > > > x86_64 modules on 32bit i386 systems? > > >> > > > >> > Yes, not sure how I missed that fact... > > >> > > > >> > > Kexec will also not allow loading an x86_64 kernel on a 32bit > > >machine. > > >> > > > >> > For crash kernel only or for regular kexec too? > > >> > > > >> > > >> I think for both. One of the possible reasons I think is that one never > > >> knows is underlying machine has got 64bit extensions or not. So even if > > >> we load the kernel it will never boot. Secondly, we might not be able to > > >> handle 64bit address in 32bit kernel/user space? > > > > > >Perhaps I am miss-understanding what you are saying, but I do > > >recally kexecing from 32->64 and 64->32 bit kernels on x86_64 hardware. > > >I can run these checks again if it helps. > > > > I stand corrected. I can kexec an bzImage 32->64bit. That's a different > thing that it ran into some initrd issues later but fundamentally kexec > could load 64bit kernel bzImage and do the successful transition. > > So it will now be left to the user. If he tries to kexec to a 64bit kernel > on a machine not supporting 32bit extensions, then kexec will not give > any advance warning.
I feel comfortable with that. Well for now anyway. But I think that Magnus has other ideas. -- Horms H: http://www.vergenet.net/~horms/ W: http://www.valinux.co.jp/en/ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
