On 12/20, Jon Medhurst (Tixy) wrote: > > On Sun, 2013-12-15 at 23:08 -0500, David Long wrote: > > From: "David A. Long" <[email protected]> > > > > Caveats: > > > > - Thumb is not supported > > - XOL abort/trap handling is not implemented > > I shall repeat my comment from version one of the patch... > > What are the consequences of this, e.g. is it possible for a probe to > get stuck in an infinite loop of faulting? I hope there are no integrity > issues for the kernel itself.
Unless there is something arm-specific, the kernel should be fine. The task should notice a signal after handle_singlestep() before it returns to the user-mode. But of course the probed application can be confused. And I have no idea what arm does if, say, a single-stepped xol insn triggers the page fault. We need to change instruction_pointer() back to the faulted (probed) insn if the page fault fails. But since because arch_uprobe_xol_was_trapped() is not implemented this won't happen. Oleg. -- 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/
