From: Rob Gardner <rob.gardner@xxxxxxxxxx> Date: Tue, 22 Dec 2015 23:24:49 -0700 > Short story: Exception handlers used by some copy_to_user() and > copy_from_user() functions do not diligently clean up floating point > register usage, and this can result in a user process seeing invalid > values in floating point registers. This sometimes makes the process > fail. Can you show me a specific example where the FPU register contents actually matter? When we are copying to or from userspace, we are in a most of the time system call, and for that specific case all FPU registers are volatile across the system call. I guess it might matter for the perf stack backtrace stuff. -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
