On Thu, Jul 29, 2021 at 05:03:34PM +0100, Mark Brown wrote: > On Thu, Jul 29, 2021 at 02:27:04PM +0100, Dave P Martin wrote: > > On Thu, Jul 29, 2021 at 12:22:17PM +0100, Mark Brown wrote: > > > > Yeah, it doesn't seem to be in the slightest bit idiomatic for the arm64 > > > asm code the kernel has. I don't know if you think it's worth adding > > > that to SYM_FUNC_START now we have it though? > > > Actually, I think the core definition of SYM_FUNC_END() in > > <linux/linkage.h> does this. > > Ah, so it does. > > > It would be good to pick up the common linkage macros; if we have to > > sprinkle .type manually all over the tests people will likely make > > mistakes, to that's probably not worth it. > > > If picking up the macros isn't trivial to do, I guess it's not that > > important at this stage. > > They're not exported from the kernel at all at the minute so that'd be a > whole new block of work that feels out of scope here, we already have a > stack of asm code in selftests. Agreed. Feels like it might be a good idea at some point, but it's orthogonal to this series, and for now nothing breaks. > > > that those are outside the kernel either. We will have to do something > > > like that if anyone starts building userspace with BTI though (or I > > > might just shove a BTI C in there unconditionally, I'm sure we'll cope > > > with the overhead on older systems). > > > I thought about that, but that .S file isn't annotated as supporting > > BTI, so I guess there's no problem for now(?) > > True, we'll generate linker warnings but it should otherwise sort itself > out unless someone forced BTI mode. The whole annotation thing really > isn't fun to deal with for assembly code, hopefully there'll be some > toolchain improvements in this area at some point. Ack Cheers ---Dave
