On Fri, 2007-08-17 at 17:05 -0700, Jeremy Fitzhardinge wrote: > Andi Kleen wrote: > > Commit 19d36ccdc34f5ed444f8a6af0cbfdb6790eb1177 "x86: Fix alternatives > > and kprobes to remap write-protected kernel text" uses code which is > > being patched for patching. > > > > In particular, paravirt_ops does patching in two stages: first it > > calls paravirt_ops.patch, then it fills any remaining instructions > > with nop_out(). nop_out calls text_poke() which calls > > lookup_address() which calls pgd_val() (aka paravirt_ops.pgd_val): > > that call site is one of the places we patch. > > > > If we always do patching as one single call to text_poke(), we only > > need make sure we're not patching the memcpy in text_poke itself. > > This means the prototype to paravirt_ops.patch needs to change, to > > marshal the new code into a buffer rather than patching in place as it > > does now. It also means all patching goes through text_poke(), which > > is known to be safe (apply_alternatives is also changed to make a > > single patch). > > > > Hi Andi, > > This patch breaks Xen booting. I get infinite recursive faults during > patching when this patch is present. If I boot with > "noreplace-paravirt" it works OK, and it works as expected if I back > this patch out. I haven't tracked down the exact failure mode; its a > little hard to debug because it overwrites all kernel memory with > recursive fault stackframes and then finally traps out to Xen when it > hits the bottom of memory. > > I think we should back this one out before .23.
Then back out 19d36ccdc34f5ed444f8a6af0cbfdb6790eb1177 too, which broke lguest booting, and this tried to fix. Rusty. - 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/
