[PATCH 1/5] aarch64: Create definitions for AARCH64_RA_SIGN_STATE register

[Mark Wielaard]

On Fri, Jun 14, 2024 at 03:47:15PM +0100, Steve Capper wrote:
> From: German Gomez <german.gomez@arm.com>
> 
> This register will be used to indicate whether a return address is
> mangled with a PAC or not, in accordance with the DWARF AARCH64 ABI [1].
> 
> [1] https://github.com/ARM-software/abi-aa/blob/main/aadwarf64/aadwarf64.rst#41dwarf-register-names

OK, so DWARF regno 34 turns from "reserved" into the ra_sign_state.

Patch looks good except for...

> --- a/backends/aarch64_init.c
> +++ b/backends/aarch64_init.c
> @@ -55,10 +55,10 @@ aarch64_init (Elf *elf __attribute__ ((unused)),
>    HOOK (eh, data_marker_symbol);
>    HOOK (eh, abi_cfi);
>  
> -  /* X0-X30 (31 regs) + SP + 1 Reserved + ELR, 30 Reserved regs (34-43)
> +  /* X0-X30 (31 regs) + SP + 1 Reserved + ELR + RA_SIGN_STATE, 30 Reserved regs (34-43)
>       + V0-V31 (32 regs, least significant 64 bits only)
> -     + ALT_FRAME_RETURN_COLUMN (used when LR isn't used) = 97 DWARF regs. */
> -  eh->frame_nregs = 97;
> +     + ALT_FRAME_RETURN_COLUMN (used when LR isn't used) = 98 DWARF regs. */
> +  eh->frame_nregs = 98;
>    HOOK (eh, set_initial_registers_tid);
>    HOOK (eh, unwind);

That should still be 97. RA_SIGN_STATE is regno 34, which was reserved
before, followed by 29 Resered regs (35-43).

Cheers,

Mark