On 6/3/19 10:55 AM, Andrey Konovalov wrote: > This patch is a part of a series that extends arm64 kernel ABI to allow to > pass tagged user pointers (with the top byte set to something else other > than 0x00) as syscall arguments. > > do_pages_move() is used in the implementation of the move_pages syscall. > > Untag user pointers in this function. > > Reviewed-by: Catalin Marinas <catalin.marinas@xxxxxxx> > Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx> > --- > mm/migrate.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/mm/migrate.c b/mm/migrate.c > index f2ecc2855a12..3930bb6fa656 100644 > --- a/mm/migrate.c > +++ b/mm/migrate.c > @@ -1617,6 +1617,7 @@ static int do_pages_move(struct mm_struct *mm, nodemask_t task_nodes, > if (get_user(node, nodes + i)) > goto out_flush; > addr = (unsigned long)p; > + addr = untagged_addr(addr); Why not just "addr = (unsigned long)untagged_addr(p);" -- Khalid
