On Thu, Feb 22, 2018 at 6:38 AM, Jan Hubicka <hubi...@ucw.cz> wrote: >> >> >> >> Hi Jan, >> >> >> >> https://gcc.gnu.org/ml/gcc-patches/2018-01/msg02233.html >> >> >> >> Is OK for trunk? >> > >> > I see that using register makes the problem go away and pushing address to >> > stack >> > seemed bit odd anyway. However how does this work on other types of thunk? >> >> Kernel only uses -mindirect-branch=thunk-extern. I am working on a proposal >> to use -mindirect-branch=thunk-extern in user space to support CET in a >> single >> binary. So at the end of the day, only >> -mindirect-branch=thunk-extern will be used. > > OK, so it is about the fact that we do not really want to support all > -mindirect-branch options in the future? If we don't want to support the > correctly, > I wonder why we are including them at all. Shall we at least output > warning/sorry
-mindirect-branch= implementation changed over time while experimenting different approaches. I didn't remove the old ones when I added new ones. We should remove others and only keep -mindirect-branch=thunk-extern with my proposal to support CET with -mindirect-branch=thunk-extern. > when user tries other thunk type with stack unwinding enabled? This is on my TODO list. > (does Kernel use it?) No, kernel doesn't use it. -- H.J.
