From e777ae44e33e48ad01bfdc978076b03c1f091b4f Mon Sep 17 00:00:00 2001 From: Daniel Gomez Date: Wed, 31 Jan 2024 14:51:25 -0800 Subject: XArray: add cmpxchg order test XArray multi-index entries do not keep track of the order stored once the entry is being marked as used with cmpxchg (conditionally replaced with NULL). Add a test to check the order is actually lost. The test also verifies the order and entries for all the tied indexes before and after the NULL replacement with xa_cmpxchg. Add another entry at 1 << order that keeps the node around and the order information for the NULL-entry after xa_cmpxchg. Link: https://lkml.kernel.org/r/20240131225125.1370598-3-mcgrof@kernel.org Signed-off-by: Daniel Gomez Signed-off-by: Luis Chamberlain Cc: Darrick J. Wong Cc: Dave Chinner Cc: Hannes Reinecke Cc: Matthew Wilcox Cc: Pankaj Raghav Signed-off-by: Andrew Morton --- lib/test_xarray.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 54 insertions(+) (limited to 'lib') diff --git a/lib/test_xarray.c b/lib/test_xarray.c index 1050e9113d2a..ebe2af2e072d 100644 --- a/lib/test_xarray.c +++ b/lib/test_xarray.c @@ -423,6 +423,59 @@ static noinline void check_cmpxchg(struct xarray *xa) XA_BUG_ON(xa, !xa_empty(xa)); } +static noinline void check_cmpxchg_order(struct xarray *xa) +{ +#ifdef CONFIG_XARRAY_MULTI + void *FIVE = xa_mk_value(5); + unsigned int i, order = 3; + + XA_BUG_ON(xa, xa_store_order(xa, 0, order, FIVE, GFP_KERNEL)); + + /* Check entry FIVE has the order saved */ + XA_BUG_ON(xa, xa_get_order(xa, xa_to_value(FIVE)) != order); + + /* Check all the tied indexes have the same entry and order */ + for (i = 0; i < (1 << order); i++) { + XA_BUG_ON(xa, xa_load(xa, i) != FIVE); + XA_BUG_ON(xa, xa_get_order(xa, i) != order); + } + + /* Ensure that nothing is stored at index '1 << order' */ + XA_BUG_ON(xa, xa_load(xa, 1 << order) != NULL); + + /* + * Additionally, keep the node information and the order at + * '1 << order' + */ + XA_BUG_ON(xa, xa_store_order(xa, 1 << order, order, FIVE, GFP_KERNEL)); + for (i = (1 << order); i < (1 << order) + (1 << order) - 1; i++) { + XA_BUG_ON(xa, xa_load(xa, i) != FIVE); + XA_BUG_ON(xa, xa_get_order(xa, i) != order); + } + + /* Conditionally replace FIVE entry at index '0' with NULL */ + XA_BUG_ON(xa, xa_cmpxchg(xa, 0, FIVE, NULL, GFP_KERNEL) != FIVE); + + /* Verify the order is lost at FIVE (and old) entries */ + XA_BUG_ON(xa, xa_get_order(xa, xa_to_value(FIVE)) != 0); + + /* Verify the order and entries are lost in all the tied indexes */ + for (i = 0; i < (1 << order); i++) { + XA_BUG_ON(xa, xa_load(xa, i) != NULL); + XA_BUG_ON(xa, xa_get_order(xa, i) != 0); + } + + /* Verify node and order are kept at '1 << order' */ + for (i = (1 << order); i < (1 << order) + (1 << order) - 1; i++) { + XA_BUG_ON(xa, xa_load(xa, i) != FIVE); + XA_BUG_ON(xa, xa_get_order(xa, i) != order); + } + + xa_store_order(xa, 0, BITS_PER_LONG - 1, NULL, GFP_KERNEL); + XA_BUG_ON(xa, !xa_empty(xa)); +#endif +} + static noinline void check_reserve(struct xarray *xa) { void *entry; @@ -1976,6 +2029,7 @@ static int xarray_checks(void) check_xas_erase(&array); check_insert(&array); check_cmpxchg(&array); + check_cmpxchg_order(&array); check_reserve(&array); check_reserve(&xa0); check_multi_store(&array); -- cgit v1.2.3