diff options
Diffstat (limited to 'tools/testing/radix-tree/maple.c')
| -rw-r--r-- | tools/testing/radix-tree/maple.c | 111 |
1 files changed, 106 insertions, 5 deletions
diff --git a/tools/testing/radix-tree/maple.c b/tools/testing/radix-tree/maple.c index cd1cf05503b4..1873ddbe16cc 100644 --- a/tools/testing/radix-tree/maple.c +++ b/tools/testing/radix-tree/maple.c @@ -14,7 +14,7 @@ #include "test.h" #include <stdlib.h> #include <time.h> -#include "linux/init.h" +#include <linux/init.h> #define module_init(x) #define module_exit(x) @@ -120,7 +120,7 @@ static noinline void __init check_new_node(struct maple_tree *mt) MT_BUG_ON(mt, mas.alloc->slot[0] == NULL); mas_push_node(&mas, mn); mas_reset(&mas); - mas_nomem(&mas, GFP_KERNEL); /* free */ + mas_destroy(&mas); mtree_unlock(mt); @@ -144,7 +144,7 @@ static noinline void __init check_new_node(struct maple_tree *mt) mn->parent = ma_parent_ptr(mn); ma_free_rcu(mn); mas.status = ma_start; - mas_nomem(&mas, GFP_KERNEL); + mas_destroy(&mas); /* Allocate 3 nodes, will fail. */ mas_node_count(&mas, 3); /* Drop the lock and allocate 3 nodes. */ @@ -161,7 +161,7 @@ static noinline void __init check_new_node(struct maple_tree *mt) MT_BUG_ON(mt, mas_allocated(&mas) != 3); /* Free. */ mas_reset(&mas); - mas_nomem(&mas, GFP_KERNEL); + mas_destroy(&mas); /* Set allocation request to 1. */ mas_set_alloc_req(&mas, 1); @@ -277,6 +277,7 @@ static noinline void __init check_new_node(struct maple_tree *mt) } mas_reset(&mas); MT_BUG_ON(mt, mas_nomem(&mas, GFP_KERNEL)); + mas_destroy(&mas); } @@ -299,7 +300,7 @@ static noinline void __init check_new_node(struct maple_tree *mt) } MT_BUG_ON(mt, mas_allocated(&mas) != total); mas_reset(&mas); - mas_nomem(&mas, GFP_KERNEL); /* Free. */ + mas_destroy(&mas); /* Free. */ MT_BUG_ON(mt, mas_allocated(&mas) != 0); for (i = 1; i < 128; i++) { @@ -35847,6 +35848,7 @@ static noinline void __init check_nomem(struct maple_tree *mt) mas_store(&ms, &ms); /* insert 1 -> &ms */ mas_nomem(&ms, GFP_KERNEL); /* Node allocated in here. */ mtree_unlock(mt); + mas_destroy(&ms); mtree_destroy(mt); } @@ -36224,6 +36226,97 @@ static noinline void __init check_mtree_dup(struct maple_tree *mt) extern void test_kmem_cache_bulk(void); +/* callback function used for check_nomem_writer_race() */ +static void writer2(void *maple_tree) +{ + struct maple_tree *mt = (struct maple_tree *)maple_tree; + MA_STATE(mas, mt, 6, 10); + + mtree_lock(mas.tree); + mas_store(&mas, xa_mk_value(0xC)); + mas_destroy(&mas); + mtree_unlock(mas.tree); +} + +/* + * check_nomem_writer_race() - test a possible race in the mas_nomem() path + * @mt: The tree to build. + * + * There is a possible race condition in low memory conditions when mas_nomem() + * gives up its lock. A second writer can chagne the entry that the primary + * writer executing the mas_nomem() path is modifying. This test recreates this + * scenario to ensure we are handling it correctly. + */ +static void check_nomem_writer_race(struct maple_tree *mt) +{ + MA_STATE(mas, mt, 0, 5); + + mt_set_non_kernel(0); + /* setup root with 2 values with NULL in between */ + mtree_store_range(mt, 0, 5, xa_mk_value(0xA), GFP_KERNEL); + mtree_store_range(mt, 6, 10, NULL, GFP_KERNEL); + mtree_store_range(mt, 11, 15, xa_mk_value(0xB), GFP_KERNEL); + + /* setup writer 2 that will trigger the race condition */ + mt_set_private(mt); + mt_set_callback(writer2); + + mtree_lock(mt); + /* erase 0-5 */ + mas_erase(&mas); + + /* index 6-10 should retain the value from writer 2 */ + check_load(mt, 6, xa_mk_value(0xC)); + mtree_unlock(mt); + + /* test for the same race but with mas_store_gfp() */ + mtree_store_range(mt, 0, 5, xa_mk_value(0xA), GFP_KERNEL); + mtree_store_range(mt, 6, 10, NULL, GFP_KERNEL); + + mas_set_range(&mas, 0, 5); + mtree_lock(mt); + mas_store_gfp(&mas, NULL, GFP_KERNEL); + + /* ensure write made by writer 2 is retained */ + check_load(mt, 6, xa_mk_value(0xC)); + + mt_set_private(NULL); + mt_set_callback(NULL); + mtree_unlock(mt); +} + + /* test to simulate expanding a vma from [0x7fffffffe000, 0x7ffffffff000) + * to [0x7ffde4ca1000, 0x7ffffffff000) and then shrinking the vma to + * [0x7ffde4ca1000, 0x7ffde4ca2000) + */ +static inline int check_vma_modification(struct maple_tree *mt) +{ + MA_STATE(mas, mt, 0, 0); + + mtree_lock(mt); + /* vma with old start and old end */ + __mas_set_range(&mas, 0x7fffffffe000, 0x7ffffffff000 - 1); + mas_preallocate(&mas, xa_mk_value(1), GFP_KERNEL); + mas_store_prealloc(&mas, xa_mk_value(1)); + + /* next write occurs partly in previous range [0, 0x7fffffffe000)*/ + mas_prev_range(&mas, 0); + /* expand vma to {0x7ffde4ca1000, 0x7ffffffff000) */ + __mas_set_range(&mas, 0x7ffde4ca1000, 0x7ffffffff000 - 1); + mas_preallocate(&mas, xa_mk_value(1), GFP_KERNEL); + mas_store_prealloc(&mas, xa_mk_value(1)); + + /* shrink vma to [0x7ffde4ca1000, 7ffde4ca2000) */ + __mas_set_range(&mas, 0x7ffde4ca2000, 0x7ffffffff000 - 1); + mas_preallocate(&mas, NULL, GFP_KERNEL); + mas_store_prealloc(&mas, NULL); + mt_dump(mt, mt_dump_hex); + + mas_destroy(&mas); + mtree_unlock(mt); + return 0; +} + void farmer_tests(void) { struct maple_node *node; @@ -36231,6 +36324,10 @@ void farmer_tests(void) mt_dump(&tree, mt_dump_dec); + mt_init_flags(&tree, MT_FLAGS_ALLOC_RANGE | MT_FLAGS_LOCK_EXTERN | MT_FLAGS_USE_RCU); + check_vma_modification(&tree); + mtree_destroy(&tree); + tree.ma_root = xa_mk_value(0); mt_dump(&tree, mt_dump_dec); @@ -36257,6 +36354,10 @@ void farmer_tests(void) check_dfs_preorder(&tree); mtree_destroy(&tree); + mt_init_flags(&tree, MT_FLAGS_ALLOC_RANGE | MT_FLAGS_USE_RCU); + check_nomem_writer_race(&tree); + mtree_destroy(&tree); + mt_init_flags(&tree, MT_FLAGS_ALLOC_RANGE); check_prealloc(&tree); mtree_destroy(&tree); |