From 08022255a9ee926896e81ba63a83bb904efe446d Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Thu, 7 Nov 2019 22:49:11 -0500 Subject: XArray: Fix xas_pause at ULONG_MAX [ Upstream commit 82a22311b7a68a78709699dc8c098953b70e4fd2 ] If we were unlucky enough to call xas_pause() when the index was at ULONG_MAX (or a multi-slot entry which ends at ULONG_MAX), we would wrap the index back around to 0 and restart the iteration from the beginning. Use the XAS_BOUNDS state to indicate that we should just stop the iteration. Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Sasha Levin --- lib/test_xarray.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) (limited to 'lib/test_xarray.c') diff --git a/lib/test_xarray.c b/lib/test_xarray.c index 03c3f42966ce..55c14e8c8859 100644 --- a/lib/test_xarray.c +++ b/lib/test_xarray.c @@ -1160,6 +1160,27 @@ static noinline void check_move_tiny(struct xarray *xa) XA_BUG_ON(xa, !xa_empty(xa)); } +static noinline void check_move_max(struct xarray *xa) +{ + XA_STATE(xas, xa, 0); + + xa_store_index(xa, ULONG_MAX, GFP_KERNEL); + rcu_read_lock(); + XA_BUG_ON(xa, xas_find(&xas, ULONG_MAX) != xa_mk_index(ULONG_MAX)); + XA_BUG_ON(xa, xas_find(&xas, ULONG_MAX) != NULL); + rcu_read_unlock(); + + xas_set(&xas, 0); + rcu_read_lock(); + XA_BUG_ON(xa, xas_find(&xas, ULONG_MAX) != xa_mk_index(ULONG_MAX)); + xas_pause(&xas); + XA_BUG_ON(xa, xas_find(&xas, ULONG_MAX) != NULL); + rcu_read_unlock(); + + xa_erase_index(xa, ULONG_MAX); + XA_BUG_ON(xa, !xa_empty(xa)); +} + static noinline void check_move_small(struct xarray *xa, unsigned long idx) { XA_STATE(xas, xa, 0); @@ -1268,6 +1289,7 @@ static noinline void check_move(struct xarray *xa) xa_destroy(xa); check_move_tiny(xa); + check_move_max(xa); for (i = 0; i < 16; i++) check_move_small(xa, 1UL << i); -- cgit v1.2.3