On Fri, 2010-01-15 at 12:12 +0100, Peter Zijlstra wrote: ... > > Adding the probe uses the fact that (most) executable mappings are > MAP_PRIVATE and CoWs a private copy of the page with the modified ins, > right? > > What does it do for MAP_SHARED|MAP_EXECUTABLE sections -- simply fail to > add the probe?
If the vma containing the instruction to be probed has the VM_EXEC flag set (and it's not in the XOL area) we go ahead and try to probe it. I'm not familar with the implications of MAP_SHARED|MAP_EXECUTABLE -- how you would get such a combo, or what access_process_vm() would do with it. Jim
