On 02/21/2012 11:29 AM, Andrew Lutomirski wrote: >> >> The vsyscall page shouldn't be mapped for x32 tasks... > > How is that possible? It lives in the fixmap and is presumably > visible from any 64-bit code. > > Admittedly, x32 tasks are probably somewhat difficult to trick into > calling addresses with high bits set, but it's not necessarily > impossible. > Fair enough, and it's not necessarily all that hard either. And it's visible even in a 32-bit task, although a 32-bit task has to switch into 64-bit mode. Yet another reason the vsyscall page needs to die. I was having delusions that we could have a task-owned PDT in negative space, but that would require unsharing the third level, too, which is just way too messy. -hpa -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
