Christoph Hellwig <hch@xxxxxx> 於 2020年7月10日 週五 下午9:57寫道：
>
> Add helpers to wraper the get_fs/set_fs magic for undoing any damange
> done by set_fs(KERNEL_DS). There is no real functional benefit, but this
> documents the intent of these calls better, and will allow stubbing the
> functions out easily for kernels builds that do not allow address space
> overrides in the future.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> ---
> arch/arm64/kernel/sdei.c | 2 +-
> arch/m68k/include/asm/tlbflush.h | 12 ++++++------
> arch/mips/kernel/unaligned.c | 27 +++++++++++++--------------
> arch/nds32/mm/alignment.c | 7 +++----
> arch/sh/kernel/traps_32.c | 18 ++++++++----------
> drivers/firmware/arm_sdei.c | 5 ++---
> include/linux/uaccess.h | 18 ++++++++++++++++++
> kernel/events/callchain.c | 5 ++---
> kernel/events/core.c | 5 ++---
> kernel/kthread.c | 5 ++---
> kernel/stacktrace.c | 5 ++---
> mm/maccess.c | 22 ++++++++++------------
> 12 files changed, 69 insertions(+), 62 deletions(-)
>
[...]
> diff --git a/arch/nds32/mm/alignment.c b/arch/nds32/mm/alignment.c
> index c8b9061a2ee3d5..1eb7ded6992b57 100644
> --- a/arch/nds32/mm/alignment.c
> +++ b/arch/nds32/mm/alignment.c
> @@ -512,7 +512,7 @@ int do_unaligned_access(unsigned long addr, struct pt_regs *regs)
> {
> unsigned long inst;
> int ret = -EFAULT;
> - mm_segment_t seg = get_fs();
> + mm_segment_t seg;
>
> inst = get_inst(regs->ipc);
>
> @@ -520,13 +520,12 @@ int do_unaligned_access(unsigned long addr, struct pt_regs *regs)
> "Faulting addr: 0x%08lx, pc: 0x%08lx [inst: 0x%08lx ]\n", addr,
> regs->ipc, inst);
>
> - set_fs(USER_DS);
> -
> + seg = force_uaccess_begin();
> if (inst & NDS32_16BIT_INSTRUCTION)
> ret = do_16((inst >> 16) & 0xffff, regs);
> else
> ret = do_32(inst, regs);
> - set_fs(seg);
> + force_uaccess_end(seg);
>
> return ret;
> }
Hi Christoph, Thank you.
Acked-by: Greentime Hu <green.hu@xxxxxxxxx>
