On 29/08/2022 18.29, Jason A. Donenfeld wrote:
On Fri, Aug 26, 2022 at 01:28:11PM +0200, Thomas Huth wrote:
+ qemu_guest_getrandom_nofail(tmp, block);
+ for (size_t i = 0; i < block; ++i) {
+ cpu_stb_data_ra(env, wrap_address(env, *buf_reg), tmp[i], ra);
+ *buf_reg = deposit64(*buf_reg, 0, message_reg_len, *buf_reg + 1);
+ --*len_reg;
I know it's annoying, but technically, you must not touch the upper bits of
the len_reg if running in 31- or 24-bit addressing mode. The Principles of
Operations say:
"In either the 24- or 31-bit addressing mode, bits 32-63 of the odd-numbered
register are decremented by the number
of bytes processed for the respective operand, and
bits 0-31 of the register remain unchanged."
This is what I was trying to do with the use of deposit64, following
David's guidance. Did I mess something up?
Sorry for not following up earlier - I've been away from keyboard for a
couple of weeks...
Anyway, that was likely a wrong comment from my side anyway - I thought that
"--*len_reg" might alter the upper bits, too, when there is no masking here.
But since "len" has been constrained earlier in the function already, I
think this cannot happen, so please never mind.
I just saw that you also sent a v8 now, so I'll follow up on that version.
Thomas
