!3280 arm64: add machine check safe support

Merge Pull Request from: @ci-robot 
 
PR sync from: Tong Tiangen <tongtiangen@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/343LHBM44UNOCW2VSYOSYXHMJJMSHETT/ 
With the increase of memory capacity and density, the probability of memory
error also increases. The increasing size and density of server RAM in data
centers and clouds have shown increased uncorrectable memory errors.

Currently, the kernel has mechanism to recover from hardware memory errors.
This patchset provides a new recovery mechanism.

For arm64, the hardware memory error handling in do_sea(), which is divided
into two cases:
 1. If the user state consumed the memory errors, the solution is to kill
    the user process and isolate the error page.
 2. If the kernel state consumed the memory errors, the solution is to
    panic.

For case 2, Undifferentiated panic may not be the optimal choice, as it can
be handled better. In some scenarios, we can avoid panic, such as uaccess,
if the uaccess fails due to memory error, only the user process will be
affected, killing the user process and isolating the user page with
hardware memory errors is a better choice.

Tong Tiangen (7):
  uaccess: add generic fallback version of copy_mc_to_user()
  arm64: add support for machine check error safe
  arm64: add uaccess to machine check safe
  mm/hwpoison: return -EFAULT when copy fail in
    copy_mc_[user]_highpage()
  arm64: support copy_mc_[user]_highpage()
  arm64: introduce copy_mc_to_kernel() implementation
  arm64: add machine check safe sysctl interface


-- 
2.25.1
 
https://gitee.com/openeuler/kernel/issues/I8M74H 
 
Link:https://gitee.com/openeuler/kernel/pulls/3280

 

Reviewed-by: Xie XiuQi <xiexiuqi@huawei.com>
Reviewed-by: Zhang Jianhua <chris.zjh@huawei.com>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>