Re: [PATCH] selftests/x86: Add a selftest for SYSRET to noncanonical addresses

2016-12-19 Thread Andy Lutomirski
On Mon, Dec 19, 2016 at 3:30 PM, Kirill A. Shutemov wrote: > On Mon, Dec 19, 2016 at 11:12:42AM -0800, Andy Lutomirski wrote: >> SYSRET to a noncanonical address will blow up on Intel CPUs. Linux >> needs to prevent this from happening in two major cases, and the >> criteria will become more comp

Re: [PATCH] selftests/x86: Add a selftest for SYSRET to noncanonical addresses

2016-12-19 Thread Kirill A. Shutemov
On Mon, Dec 19, 2016 at 11:12:42AM -0800, Andy Lutomirski wrote: > SYSRET to a noncanonical address will blow up on Intel CPUs. Linux > needs to prevent this from happening in two major cases, and the > criteria will become more complicated when support for larger virtual > address spaces is added

[PATCH] selftests/x86: Add a selftest for SYSRET to noncanonical addresses

2016-12-19 Thread Andy Lutomirski
SYSRET to a noncanonical address will blow up on Intel CPUs. Linux needs to prevent this from happening in two major cases, and the criteria will become more complicated when support for larger virtual address spaces is added. A fast-path SYSCALL will fallthrough to the following instruction usin