On 04/01/2024 5:13 pm, Tamas K Lengyel wrote:
> Fix warning:
> (XEN) UBSAN: Undefined behaviour in arch/x86/cpu/mwait-idle.c:1300:44
> (XEN) left shift of 15 by 28 places cannot be represented in type 'int'
>
> Signed-off-by: Tamas K Lengyel <tamas.leng...@intel.com>
> Fixes: 5a211704e88 ("mwait-idle: prevent SKL-H boot failure when C8+C9+C10
> enabled")
Reviewed-by: Andrew Cooper <andrew.coop...@citrix.com>
It's perhaps worth saying this is in sklh_idle_state_table_update()
which is why it only manifests on a single CPU. Happy to adjust on commit.
All other uses of this constant shift right first, and then mask, hence
why they don't trip UBSAN.
~Andrew
