Hi, On Mon, 8 Jan 2018, H.J. Lu wrote:
> On Mon, Jan 8, 2018 at 4:00 AM, Jakub Jelinek <ja...@redhat.com> wrote: > > On Mon, Jan 08, 2018 at 03:55:52AM -0800, H.J. Lu wrote: > >> > I'm wondering whether thunk creation can be a good target-independent > >> > generalization? I guess > >> > we can emit the function declaration without direct writes to > >> > asm_out_file? And the emission > >> > of function body can be potentially a target hook? > >> > > >> > What about emitting body of the function with RTL instructions instead > >> > of direct assembly write? > >> > My knowledge of RTL is quite small, but maybe it can bring some > >> > generalization and reusability > >> > for other targets? > >> > >> Thunks are x86 specific and they are created the same way as 32-bit PIC > >> thunks. > >> I don't see how a target hook is used. > > > > Talking about PIC thunks, those have I believe . character in their symbols, > > so that they can't be confused with user functions. Any reason these > > retpoline thunks aren't? > > > > They used to have '.'. It was changed at the last minute since kernel > needs to export them as regular symbols. That can be done via asm aliases or direct assembler use; the kernel doesn't absolutely have to access them via C compatible symbol names. Ciao, Michael.
