Expand the current robust list test for the new set_robust_list2 syscall. Create an option to make it possible to run the same tests using the new syscall, and also add two new relevant test: test long lists (bigger than ROBUST_LIST_LIMIT) and for unaligned addresses. Signed-off-by: André Almeida <andrealmeid@xxxxxxxxxx> --- .../selftests/futex/functional/robust_list.c | 160 +++++++++++++++++- 1 file changed, 156 insertions(+), 4 deletions(-) diff --git a/tools/testing/selftests/futex/functional/robust_list.c b/tools/testing/selftests/futex/functional/robust_list.c index 42690b2440fd..201acbeeac5a 100644 --- a/tools/testing/selftests/futex/functional/robust_list.c +++ b/tools/testing/selftests/futex/functional/robust_list.c @@ -35,16 +35,45 @@ #include <stddef.h> #include <sys/mman.h> #include <sys/wait.h> +#include <stdint.h> #define STACK_SIZE (1024 * 1024) #define FUTEX_TIMEOUT 3 +#define SYS_set_robust_list2 467 + +enum robust_list2_type { + ROBUST_LIST_32BIT, + ROBUST_LIST_64BIT, +}; + static pthread_barrier_t barrier, barrier2; +bool robust2 = false; + int set_robust_list(struct robust_list_head *head, size_t len) { - return syscall(SYS_set_robust_list, head, len); + int ret, flags; + + if (!robust2) { + return syscall(SYS_set_robust_list, head, len); + } + + if (sizeof(head) == 8) + flags = ROBUST_LIST_64BIT; + else + flags = ROBUST_LIST_32BIT; + + /* + * We act as we have just one list here. We try to use the first slot, + * but if it hasn't been alocated yet we allocate it. + */ + ret = syscall(SYS_set_robust_list2, head, 0, flags); + if (ret == -1 && errno == ENOENT) + ret = syscall(SYS_set_robust_list2, head, -1, flags); + + return ret; } int get_robust_list(int pid, struct robust_list_head **head, size_t *len_ptr) @@ -246,6 +275,11 @@ static void test_set_robust_list_invalid_size(void) size_t head_size = sizeof(struct robust_list_head); int ret; + if (robust2) { + ksft_test_result_skip("This test is only for old robust interface\n"); + return; + } + ret = set_robust_list(&head, head_size); ASSERT_EQ(ret, 0); @@ -321,6 +355,11 @@ static void test_get_robust_list_child(void) struct robust_list_head head, *get_head; size_t len_ptr; + if (robust2) { + ksft_test_result_skip("Not implemented in the new robust interface\n"); + return; + } + ret = pthread_barrier_init(&barrier, NULL, 2); ret = pthread_barrier_init(&barrier2, NULL, 2); ASSERT_EQ(ret, 0); @@ -332,7 +371,7 @@ static void test_get_robust_list_child(void) ret = get_robust_list(tid, &get_head, &len_ptr); ASSERT_EQ(ret, 0); - ASSERT_EQ(&head, get_head); + ASSERT_EQ(get_head, &head); pthread_barrier_wait(&barrier2); @@ -507,11 +546,119 @@ static void test_circular_list(void) ksft_test_result_pass("%s\n", __func__); } +#define ROBUST_LIST_LIMIT 2048 +#define CHILD_LIST_LIMIT (ROBUST_LIST_LIMIT + 10) + +static int child_robust_list_limit(void *arg) +{ + struct lock_struct *locks; + struct robust_list *list; + struct robust_list_head head; + int ret, i; + + locks = (struct lock_struct *) arg; + + ret = set_list(&head); + if (ret) + ksft_test_result_fail("set_list error\n"); + + /* + * Create a very long list of locks + */ + head.list.next = &locks[0].list; + + list = head.list.next; + for (i = 0; i < CHILD_LIST_LIMIT - 1; i++) { + list->next = &locks[i+1].list; + list = list->next; + } + list->next = &head.list; + + /* + * Grab the lock in the last one, and die without releasing it + */ + mutex_lock(&locks[CHILD_LIST_LIMIT], &head, false); + pthread_barrier_wait(&barrier); + + sleep(1); + + return 0; +} + +/* + * The old robust list used to have a limit of 2048 items from the kernel side. + * After this limit the kernel stops walking the list and ignore the other + * futexes, causing deadlocks. + * + * For the new interface, test if we can wait for a list of more than 2048 + * elements. + */ +static void test_robust_list_limit(void) +{ + struct lock_struct locks[CHILD_LIST_LIMIT + 1]; + _Atomic(unsigned int) *futex = &locks[CHILD_LIST_LIMIT].futex; + struct robust_list_head head; + int ret; + + if (!robust2) { + ksft_test_result_skip("This test is only for new robust interface\n"); + return; + } + + *futex = 0; + + ret = set_list(&head); + ASSERT_EQ(ret, 0); + + ret = pthread_barrier_init(&barrier, NULL, 2); + ASSERT_EQ(ret, 0); + + create_child(child_robust_list_limit, locks); + + /* + * After the child thread creates the very long list of locks, wait on + * the last one. + */ + pthread_barrier_wait(&barrier); + ret = mutex_lock(&locks[CHILD_LIST_LIMIT], &head, false); + + if (ret != 0) + printf("futex wait returned %d\n", errno); + ASSERT_EQ(ret, 0); + + ASSERT_TRUE(*futex | FUTEX_OWNER_DIED); + + wait(NULL); + pthread_barrier_destroy(&barrier); + + ksft_test_result_pass("%s\n", __func__); +} + +/* + * The kernel should refuse an unaligned head pointer + */ +static void test_unaligned_address(void) +{ + struct robust_list_head head, *h; + int ret; + + if (!robust2) { + ksft_test_result_skip("This test is only for new robust interface\n"); + return; + } + + h = (struct robust_list_head *) ((uintptr_t) &head + 1); + ret = set_list(h); + ASSERT_EQ(ret, -1); + ASSERT_EQ(errno, EINVAL); +} + void usage(char *prog) { printf("Usage: %s\n", prog); printf(" -c Use color\n"); printf(" -h Display this help message\n"); + printf(" -n Use robust2 syscall\n"); printf(" -v L Verbosity level: %d=QUIET %d=CRITICAL %d=INFO\n", VQUIET, VCRITICAL, VINFO); } @@ -520,7 +667,7 @@ int main(int argc, char *argv[]) { int c; - while ((c = getopt(argc, argv, "cht:v:")) != -1) { + while ((c = getopt(argc, argv, "chnt:v:")) != -1) { switch (c) { case 'c': log_color(1); @@ -531,6 +678,9 @@ int main(int argc, char *argv[]) case 'v': log_verbosity(atoi(optarg)); break; + case 'n': + robust2 = true; + break; default: usage(basename(argv[0])); exit(1); @@ -538,7 +688,7 @@ int main(int argc, char *argv[]) } ksft_print_header(); - ksft_set_plan(7); + ksft_set_plan(8); test_robustness(); @@ -548,6 +698,8 @@ int main(int argc, char *argv[]) test_set_list_op_pending(); test_robust_list_multiple_elements(); test_circular_list(); + test_robust_list_limit(); + test_unaligned_address(); ksft_print_cnts(); return 0; -- 2.48.1