diff options
Diffstat (limited to 'tools/testing/radix-tree/iteration_check.c')
| -rw-r--r-- | tools/testing/radix-tree/iteration_check.c | 210 |
1 files changed, 210 insertions, 0 deletions
diff --git a/tools/testing/radix-tree/iteration_check.c b/tools/testing/radix-tree/iteration_check.c new file mode 100644 index 000000000..e9908bcb0 --- /dev/null +++ b/tools/testing/radix-tree/iteration_check.c @@ -0,0 +1,210 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * iteration_check.c: test races having to do with xarray iteration + * Copyright (c) 2016 Intel Corporation + * Author: Ross Zwisler <ross.zwisler@linux.intel.com> + */ +#include <pthread.h> +#include "test.h" + +#define NUM_THREADS 5 +#define MAX_IDX 100 +#define TAG XA_MARK_0 +#define NEW_TAG XA_MARK_1 + +static pthread_t threads[NUM_THREADS]; +static unsigned int seeds[3]; +static DEFINE_XARRAY(array); +static bool test_complete; +static int max_order; + +void my_item_insert(struct xarray *xa, unsigned long index) +{ + XA_STATE(xas, xa, index); + struct item *item = item_create(index, 0); + int order; + +retry: + xas_lock(&xas); + for (order = max_order; order >= 0; order--) { + xas_set_order(&xas, index, order); + item->order = order; + if (xas_find_conflict(&xas)) + continue; + xas_store(&xas, item); + xas_set_mark(&xas, TAG); + break; + } + xas_unlock(&xas); + if (xas_nomem(&xas, GFP_KERNEL)) + goto retry; + if (order < 0) + free(item); +} + +/* relentlessly fill the array with tagged entries */ +static void *add_entries_fn(void *arg) +{ + rcu_register_thread(); + + while (!test_complete) { + unsigned long pgoff; + + for (pgoff = 0; pgoff < MAX_IDX; pgoff++) { + my_item_insert(&array, pgoff); + } + } + + rcu_unregister_thread(); + + return NULL; +} + +/* + * Iterate over tagged entries, retrying when we find ourselves in a deleted + * node and randomly pausing the iteration. + */ +static void *tagged_iteration_fn(void *arg) +{ + XA_STATE(xas, &array, 0); + void *entry; + + rcu_register_thread(); + + while (!test_complete) { + xas_set(&xas, 0); + rcu_read_lock(); + xas_for_each_marked(&xas, entry, ULONG_MAX, TAG) { + if (xas_retry(&xas, entry)) + continue; + + if (rand_r(&seeds[0]) % 50 == 0) { + xas_pause(&xas); + rcu_read_unlock(); + rcu_barrier(); + rcu_read_lock(); + } + } + rcu_read_unlock(); + } + + rcu_unregister_thread(); + + return NULL; +} + +/* + * Iterate over the entries, retrying when we find ourselves in a deleted + * node and randomly pausing the iteration. + */ +static void *untagged_iteration_fn(void *arg) +{ + XA_STATE(xas, &array, 0); + void *entry; + + rcu_register_thread(); + + while (!test_complete) { + xas_set(&xas, 0); + rcu_read_lock(); + xas_for_each(&xas, entry, ULONG_MAX) { + if (xas_retry(&xas, entry)) + continue; + + if (rand_r(&seeds[1]) % 50 == 0) { + xas_pause(&xas); + rcu_read_unlock(); + rcu_barrier(); + rcu_read_lock(); + } + } + rcu_read_unlock(); + } + + rcu_unregister_thread(); + + return NULL; +} + +/* + * Randomly remove entries to help induce retries in the + * two iteration functions. + */ +static void *remove_entries_fn(void *arg) +{ + rcu_register_thread(); + + while (!test_complete) { + int pgoff; + struct item *item; + + pgoff = rand_r(&seeds[2]) % MAX_IDX; + + item = xa_erase(&array, pgoff); + if (item) + item_free(item, pgoff); + } + + rcu_unregister_thread(); + + return NULL; +} + +static void *tag_entries_fn(void *arg) +{ + rcu_register_thread(); + + while (!test_complete) { + tag_tagged_items(&array, 0, MAX_IDX, 10, TAG, NEW_TAG); + } + rcu_unregister_thread(); + return NULL; +} + +/* This is a unit test for a bug found by the syzkaller tester */ +void iteration_test(unsigned order, unsigned test_duration) +{ + int i; + + printv(1, "Running %siteration tests for %d seconds\n", + order > 0 ? "multiorder " : "", test_duration); + + max_order = order; + test_complete = false; + + for (i = 0; i < 3; i++) + seeds[i] = rand(); + + if (pthread_create(&threads[0], NULL, tagged_iteration_fn, NULL)) { + perror("create tagged iteration thread"); + exit(1); + } + if (pthread_create(&threads[1], NULL, untagged_iteration_fn, NULL)) { + perror("create untagged iteration thread"); + exit(1); + } + if (pthread_create(&threads[2], NULL, add_entries_fn, NULL)) { + perror("create add entry thread"); + exit(1); + } + if (pthread_create(&threads[3], NULL, remove_entries_fn, NULL)) { + perror("create remove entry thread"); + exit(1); + } + if (pthread_create(&threads[4], NULL, tag_entries_fn, NULL)) { + perror("create tag entry thread"); + exit(1); + } + + sleep(test_duration); + test_complete = true; + + for (i = 0; i < NUM_THREADS; i++) { + if (pthread_join(threads[i], NULL)) { + perror("pthread_join"); + exit(1); + } + } + + item_kill_tree(&array); +} |