Rich Felker <dalias@xxxxxxxxxx> writes: > On Sat, Jan 10, 2015 at 04:14:57AM +0000, Al Viro wrote: >> Except that if your interpreter does stat(2) (or access(2), or getxattr(2), >> etc.) before bothering with open(2), you'll get screwed. > > Yes, but I think that would be very bad interpreter design. > stat/getxattr/access/whatever followed by open is always a TOCTOU > race. The correct sequence of actions is always open followed by > fstat/fgetxattr/... Sigh. I think everyone who has looked at this has been blind. If userspace is reasonable all we have to do is fix /proc/self/exe for shell scripts to point at the actual script, and then pass /proc/self/exe on the shell scripts command line. At a practical level we have to worry about backwards compability and chroot jails. But the existence of a clean implementation with /proc/self/exe serves a proof of concept that it would not be too difficult. When someone cares enough to implement it. Eric -- 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
