Re: Differing PAC behavior between Qemu and Arm FVP

[Derrick McKee]

Thanks!  I was completely unaware of that type of constraint.  I thankfully never ran into a bug involving this, but it would have been a hell of a time tracking it down!

On Tue, Jul 28, 2020 at 4:01 PM Richard Henderson <richard.henderson@linaro.org> wrote:

On 7/28/20 11:15 AM, Derrick McKee wrote:
> asm("pacda %[loc], %[mod]"
> : "=r"(result)
> : [loc] "r"(addr_to_use), [mod] "r"(modifier)
> :
>   );

As an aside, this asm statement is buggy.  You need to use a matching
constraint to force RESULT and ADDR_TO_USE to be in the same register.

Like so:

  [loc] "0"(addr_to_use)


r~

--

Derrick McKee
Phone: (703) 957-9362
Email: derrick.mckee@gmail.com