diff --git a/arch/riscv/mm/fault.c b/arch/riscv/mm/fault.c index cec8be9e2d6a..5b72e60c5a6b 100644 --- a/arch/riscv/mm/fault.c +++ b/arch/riscv/mm/fault.c @@ -29,6 +29,7 @@ #include #include +#include /* * This routine handles page faults. It determines the address and the @@ -278,6 +279,18 @@ asmlinkage void do_page_fault(struct pt_regs *regs) pte_k = pte_offset_kernel(pmd_k, addr); if (!pte_present(*pte_k)) goto no_context; + + /* + * The kernel assumes that TLBs don't cache invalid + * entries, but in RISC-V, SFENCE.VMA specifies an + * ordering constraint, not a cache flush; it is + * necessary even after writing invalid entries. + * Relying on flush_tlb_fix_spurious_fault would + * suffice, but the extra traps reduce + * performance. So, eagerly SFENCE.VMA. + */ + local_flush_tlb_page(addr); + return; } }