metag/usercopy: Zero rest of buffer from copy_from_user
Currently we try to zero the destination for a failed read from userland
in fixup code in the usercopy.c macros. The rest of the destination
buffer is then zeroed from __copy_user_zeroing(), which is used for both
copy_from_user() and __copy_from_user().
Unfortunately we fail to zero in the fixup code as D1Ar1 is set to 0
before the fixup code entry labels, and __copy_from_user() shouldn't even
be zeroing the rest of the buffer.
Move the zeroing out into copy_from_user() and rename
__copy_user_zeroing() to raw_copy_from_user() since it no longer does
any zeroing. This also conveniently matches the name needed for
RAW_COPY_USER support in a later patch.
Fixes: 373cd784d0fc ("metag: Memory handling")
Reported-by: Al Viro <firstname.lastname@example.org>
Signed-off-by: James Hogan <email@example.com>
2 files changed