On 25/10/2023 10:28 pm, Josh Poimboeuf wrote: > On Wed, Oct 25, 2023 at 10:10:41PM +0100, Andrew Cooper wrote: >> On 25/10/2023 9:52 pm, Pawan Gupta wrote: >>> diff --git a/arch/x86/entry/entry.S b/arch/x86/entry/entry.S >>> index bfb7bcb362bc..f8ba0c0b6e60 100644 >>> --- a/arch/x86/entry/entry.S >>> +++ b/arch/x86/entry/entry.S >>> @@ -20,3 +23,16 @@ SYM_FUNC_END(entry_ibpb) >>> EXPORT_SYMBOL_GPL(entry_ibpb); >>> >>> .popsection >>> + >>> +.pushsection .entry.text, "ax" >>> + >>> +.align L1_CACHE_BYTES, 0xcc >>> +SYM_CODE_START_NOALIGN(mds_verw_sel) >>> + UNWIND_HINT_UNDEFINED >>> + ANNOTATE_NOENDBR >>> + .word __KERNEL_DS >> You need another .align here. Otherwise subsequent code will still >> start in this cacheline and defeat the purpose of trying to keep it >> separate. >> >>> +SYM_CODE_END(mds_verw_sel); >> Thinking about it, should this really be CODE and not a data entry? >> >> It lives in .entry.text but it really is data and objtool shouldn't be >> writing ORC data for it at all. >> >> (Not to mention that if it's marked as STT_OBJECT, objdump -d will do >> the sensible thing and not even try to disassemble it). >> >> ~Andrew >> >> P.S. Please CC on the full series. Far less effort than fishing the >> rest off lore. > +1 to putting it in .rodata or so. It's necessarily in .entry.text so it doesn't explode with KPTI active. ~Andrew
