Commit 39cefc5f6cd2 for kernel

commit 39cefc5f6cd25d555e0455b24810e9aff365b8d6
Merge: d556a9aeb62a 7e1864332fbc
Author: Palmer Dabbelt <palmer@rivosinc.com>
Date:   Thu Dec 1 11:38:39 2022 -0800

    RISC-V: Fix a race condition during kernel stack overflow

    This fixes a concrete bug but is also the basis for some cleanup work,
    so I'm merging it based on the offending commit in order to minimize
    future conflicts.

    * commit '7e1864332fbc1b993659eab7974da9fe8bf8c128':
      riscv: fix race when vmap stack overflow