From: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
commit c36d451ad386b34f452fc3c8621ff14b9eaa31a6 upstream.
Inspired by the recent Coverity report, I looked for other places where
the offset wasn't being converted to an unsigned long before being
shifted, and I found one in xas_pause() when the entry being paused is
of order >32.
Fixes: b803b42823d0 ("xarray: Add XArray iterators")
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
lib/test_xarray.c | 37 +++++++++++++++++++++++++++++++++++++
lib/xarray.c | 2 +-
2 files changed, 38 insertions(+), 1 deletion(-)
--- a/lib/test_xarray.c
+++ b/lib/test_xarray.c
@@ -1156,6 +1156,42 @@ static noinline void check_find_entry(st
XA_BUG_ON(xa, !xa_empty(xa));
}
+static noinline void check_pause(struct xarray *xa)
+{
+ XA_STATE(xas, xa, 0);
+ void *entry;
+ unsigned int order;
+ unsigned long index = 1;
+ unsigned int count = 0;
+
+ for (order = 0; order < order_limit; order++) {
+ XA_BUG_ON(xa, xa_store_order(xa, index, order,
+ xa_mk_index(index), GFP_KERNEL));
+ index += 1UL << order;
+ }
+
+ rcu_read_lock();
+ xas_for_each(&xas, entry, ULONG_MAX) {
+ XA_BUG_ON(xa, entry != xa_mk_index(1UL << count));
+ count++;
+ }
+ rcu_read_unlock();
+ XA_BUG_ON(xa, count != order_limit);
+
+ count = 0;
+ xas_set(&xas, 0);
+ rcu_read_lock();
+ xas_for_each(&xas, entry, ULONG_MAX) {
+ XA_BUG_ON(xa, entry != xa_mk_index(1UL << count));
+ count++;
+ xas_pause(&xas);
+ }
+ rcu_read_unlock();
+ XA_BUG_ON(xa, count != order_limit);
+
+ xa_destroy(xa);
+}
+
static noinline void check_move_tiny(struct xarray *xa)
{
XA_STATE(xas, xa, 0);
@@ -1664,6 +1700,7 @@ static int xarray_checks(void)
check_xa_alloc();
check_find(&array);
check_find_entry(&array);
+ check_pause(&array);
check_account(&array);
check_destroy(&array);
check_move(&array);
--- a/lib/xarray.c
+++ b/lib/xarray.c
@@ -970,7 +970,7 @@ void xas_pause(struct xa_state *xas)
xas->xa_node = XAS_RESTART;
if (node) {
- unsigned int offset = xas->xa_offset;
+ unsigned long offset = xas->xa_offset;
while (++offset < XA_CHUNK_SIZE) {
if (!xa_is_sibling(xa_entry(xas->xa, node, offset)))
break;
