Messages in this thread | | | Date | Thu, 19 Sep 2013 23:43:35 -0500 | From | "H. Peter Anvin" <> | Subject | Re: [PATCH 01/11] x86: Use asm goto to implement better modify_and_test() functions |
| |
On 09/19/2013 03:31 AM, Andi Kleen wrote: > On Wed, Sep 18, 2013 at 02:02:37PM -0500, H. Peter Anvin wrote: >> Yes, a bit sad. We allow bracketing with the get/put_user_try/catch blocks, but that is x86-specific. >> >> I don't think a generic option is possible without compiler support, but it might be possible to do better than we do know. > > Letting the compiler do it is a bit risky, because it may open it up for > really large blocks, thus defeating the security advantages. > > -Andi >
The compiler support. if done right, should avoid unannotated memory references. This is a pretty big job in the compiler, though.
-hpa
| |