mainline inclusion
from mainline-v5.19
commit ec6aba3d
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5QM0N
CVE: NA

-------------------------------------------------

The reason for kprobe::fault_handler(), as given by their comment:

 * We come here because instructions in the pre/post
 * handler caused the page_fault, this could happen
 * if handler tries to access user space by
 * copy_from_user(), get_user() etc. Let the
 * user-specified handler try to fix it first.

Is just plain bad. Those other handlers are ran from non-preemptible
context and had better use _nofault() functions. Also, there is no
upstream usage of this.
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Acked-by: NMasami Hiramatsu <mhiramat@kernel.org>
Link: https://lore.kernel.org/r/20210525073213.561116662@infradead.org