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I haven’t investigated this. > + > +.pushsection .noinstr.text, "ax" > +SYM_CODE_START(fill_return_buffer) > + __FILL_RETURN_BUFFER(%_ASM_AX,RSB_CLEAR_LOOPS) > + RET > +SYM_CODE_END(fill_return_buffer) > +.popsection > I'm getting this error when buiding the ASI patchset: OBJCOPY modules.builtin.modinfo GEN modules.builtin GEN .vmlinux.objs MODPOST Module.symvers ERROR: modpost: "fill_return_buffer" [arch/x86/kvm/kvm.ko] undefined! make[2]: *** [scripts/Makefile.modpost:145: Module.symvers] Error 1 make[1]: *** [/home/shivank/linux/Makefile:1871: modpost] Error 2 make: *** [Makefile:240: __sub-make] Error 2 I'm wondering if we need to annotate the asm code with UNWIND_HINT_FUNC and EXPORT the fill_return_buffer and to avoid this? --- diff --git a/arch/x86/lib/retpoline.S b/arch/x86/lib/retpoline.S index db5b8ee01efe..4084ab49e2a7 100644 --- a/arch/x86/lib/retpoline.S +++ b/arch/x86/lib/retpoline.S @@ -399,7 +399,9 @@ EXPORT_SYMBOL(__x86_return_thunk) .pushsection .noinstr.text, "ax" SYM_CODE_START(fill_return_buffer) + UNWIND_HINT_FUNC __FILL_RETURN_BUFFER(%_ASM_AX,RSB_CLEAR_LOOPS) RET SYM_CODE_END(fill_return_buffer) +__EXPORT_THUNK(fill_return_buffer) .popsection --- This solved the issue for me. Thanks, Shivank