Re: [Qemu-devel] [PATCH] tcg/aarch64: Fix tcg_out_qemu_{ld, st} for linux-user

[Richard Henderson <rth@twiddle.net>]

On 08/27/2015 04:47 PM, Andreas Färber wrote:
> The argument order for the !CONFIG_SOFTMMU case was jumbled up since
> ffc6372851d8631a9f9fa56ec613b3244dc635b9 ("tcg/aarch64: use 32-bit
> offset for 32-bit user-mode emulation"), regressing from -rc2 to v2.4.0.
> Fix their order to avoid segfaults, e.g., in openSUSE's GNU coreutils 8.24.

Nack.  The argument order is correct, that is...

> -    tcg_out_qemu_ld_direct(s, memop, ext, data_reg,
> -                           guest_base ? TCG_REG_GUEST_BASE : TCG_REG_XZR,
> -                           otype, addr_reg);
> +    tcg_out_qemu_ld_direct(s, memop, ext, data_reg, addr_reg, otype,
> +                           guest_base ? TCG_REG_GUEST_BASE : TCG_REG_XZR);

TCG_REG_GUEST_BASE is definitely the "base" register, holding a 64-bit host 
address, while addr_reg is the "offset" register, holding a (potentially) 
32-bit guest address.  It is (supposed to be) the "offset" register to which 
the zero-extend is applied.

If something's wrong, and I'm not currently in a position to verify one way or 
another, it's in tcg_out_insn_3310.


r~