Re: [PATCH v2 19/28] target/arm: Implement new v8.1M NOCP check for exception return

2020-12-01 Thread Richard Henderson
On 11/19/20 3:56 PM, Peter Maydell wrote: > In v8.1M a new exception return check is added which may cause a NOCP > UsageFault (see rule R_XLTP): before we clear s0..s15 and the FPSCR > we must check whether access to CP10 from the Security state of the > returning exception is disabled; if it is

[PATCH v2 19/28] target/arm: Implement new v8.1M NOCP check for exception return

2020-11-19 Thread Peter Maydell
In v8.1M a new exception return check is added which may cause a NOCP UsageFault (see rule R_XLTP): before we clear s0..s15 and the FPSCR we must check whether access to CP10 from the Security state of the returning exception is disabled; if it is then we must take a fault. (Note that for our