[PATCH 5/7] riscv: mm: accelerate pagefault when badaccess

[Kefeng Wang]

The vm_flags of vma already checked under per-VMA lock, if it is a
bad access, directly handle error and return, there is no need to
lock_mm_and_find_vma() and check vm_flags again.

Signed-off-by: Kefeng Wang <wangkefeng.w...@huawei.com>
---
 arch/riscv/mm/fault.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/riscv/mm/fault.c b/arch/riscv/mm/fault.c
index 3ba1d4dde5dd..b3fcf7d67efb 100644
--- a/arch/riscv/mm/fault.c
+++ b/arch/riscv/mm/fault.c
@@ -292,7 +292,10 @@ void handle_page_fault(struct pt_regs *regs)
 
        if (unlikely(access_error(cause, vma))) {
                vma_end_read(vma);
-               goto lock_mmap;
+               count_vm_vma_lock_event(VMA_LOCK_SUCCESS);
+               tsk->thread.bad_cause = SEGV_ACCERR;
+               bad_area_nosemaphore(regs, code, addr);
+               return;
        }
 
        fault = handle_mm_fault(vma, addr, flags | FAULT_FLAG_VMA_LOCK, regs);
-- 
2.27.0