On 7/11/2022 10:37 PM, Jean-Philippe Brucker wrote:

On Mon, Jul 11, 2022 at 10:16:00PM +0800, Xu Kuohai wrote:

quoted

quoted

quoted

+	if (save_ret)
+		emit(A64_STR64I(p->jited ? r0 : A64_R(0), A64_SP, retval_off),
+		     ctx);

This should be only A64_R(0), not r0. r0 happens to equal A64_R(0) when
jitted due to the way build_epilogue() builds the function at the moment,
but we shouldn't rely on that.

looks like I misunderstood something, will change it to:

/* store return value, which is held in x0 for interpreter and in
 * bpf register r0 for JIT,

It's simpler than that: in both cases the return value is in x0 because
the function follows the procedure call standard. You could drop the
comment to avoid confusion and only do the change to A64_R(0)

OK, will send v9 since v8 was just sent

Thanks,
Jean

quoted

 but r0 happens to equal x0 due to the
 * way build_epilogue() builds the JIT image.
 */
if (save_ret)
        emit(A64_STR64I(A64_R(0), A64_SP, retval_off), ctx);

quoted

Apart from that, for the series

Reviewed-by: Jean-Philippe Brucker <redacted>

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