Re: [patch 13/26] Xen-paravirt_ops: Consistently wrap paravirt ops callsites to make them patchable
From: Andi Kleen <hidden>
Date: 2007-03-18 17:04:17
Also in:
lkml, virtualization, xen-devel
Possibly related (same subject, not in this thread)
- 2007-04-12 · Re: [patch 13/26] Xen-paravirt_ops: Consistently wrap paravirt ops callsites to make them patchable · David Miller <davem@davemloft.net>
- 2007-03-21 · Re: [patch 13/26] Xen-paravirt_ops: Consistently wrap paravirt ops callsites to make them patchable · Andrew Morton <akpm@linux-foundation.org>
- 2007-03-21 · Re: [patch 13/26] Xen-paravirt_ops: Consistently wrap paravirt ops callsites to make them patchable · Zachary Amsden <hidden>
- 2007-03-21 · Re: [patch 13/26] Xen-paravirt_ops: Consistently wrap paravirt ops callsites to make them patchable · Linus Torvalds <torvalds@linux-foundation.org>
- 2007-03-21 · Re: [patch 13/26] Xen-paravirt_ops: Consistently wrap paravirt ops callsites to make them patchable · Zachary Amsden <hidden>
The bigger problem is that you don't know what registers you can clobber. For the pv_ops in hand-written asm, that a big pain. The code either has to assume the worst, or the "relocator" has to do something more sophisticated (like look for push/pop pairs surrounding the call, perhaps?).
You could use the dwarf2 unwind tables. They have exact information what register has what. But it would likely get complicated. -Andi