From: Andi Kleen <ak at muc.de> Date: Fri, 9 Feb 2007 12:50:06 +0100 > > > Yes, it is a bit, umm, innovative. If it is going to be kept, even if > > just for devel logging, you should disable interrupts around it. > > Changing segments is not a normal thing to do. > > Actually that wouldn't be needed because interrupts are not allowed to do any > user accesses. And contrary to the name it doesn't actually change > the segment registers, only state used by *_user. That's right and we use this construct all throughout the syscall compatibility layer for 64-bit platforms.