alpha: split the prefetch check in do_page_fault() by mode

Before EV6, a load into $31 or $f31 could fault, so do_page_fault()
reads the faulting instruction and skips it if it is such a prefetch.
The PC can be a user or a kernel address, since the check runs for
faults from either mode, and it reads it with __get_user() either way.
That only works because alpha's __get_user() does no address check.  It
also ignores the error, relying on the fault fixup zeroing the
instruction, which does not decode as a prefetch.

Move the check into is_prefetch(), and read the instruction with
get_user() for a user-mode PC and get_kernel_nofault() for a kernel one.
A failed read now explicitly means "not a prefetch".

This is part of getting rid of __get_user() and __put_user() entirely.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

0 files changed, 0 insertions, 0 deletions