RE: [PATCH 1/2] x86/fred: Fix build with clang

From: Li, Xin3
Date: Sun Jan 28 2024 - 15:28:03 EST


> >>> @@ -43,13 +43,12 @@ SYM_INNER_LABEL(asm_fred_exit_user,
> >> SYM_L_GLOBAL)
> >>> _ASM_EXTABLE_TYPE(1b, asm_fred_entrypoint_user, EX_TYPE_ERETU)
> >>> SYM_CODE_END(asm_fred_entrypoint_user)
> >>>
> >>> -.fill asm_fred_entrypoint_kernel - ., 1, 0xcc
> >>> -
> >>> /*
> >>> * The new RIP value that FRED event delivery establishes is
> >>> * (IA32_FRED_CONFIG & ~FFFH) + 256 for events that occur in
> >>> * ring 0, i.e., asm_fred_entrypoint_user + 256.
> >>> */
> >>> + .fill asm_fred_entrypoint_user + 256 - ., 1, 0xcc
> >>> .org asm_fred_entrypoint_user + 256
> >>> SYM_CODE_START_NOALIGN(asm_fred_entrypoint_kernel)
> >>> FRED_ENTER
> >>
> >> .fill and .org here are redundant; in fact, there two directives mean
> >> exactly the same thing except that .org implicitly subtracts the current offset.
> >
> > Ah, right, .fill already does the job!
> >
> > I will remove .org.
> >
>
> Incidentally, was there a problem with .org ..., 0xcc?

Oh, it's just that I didn't know .org can be used to fill.


> Not a criticism, I just want to know to better understand current binutils
> limitations.
>
> -hpa