Hello,
kernel test robot noticed "kernel-selftests.vDSO.vdso_standalone_test_x86.fail" on:
commit: f68b079b1d5ec46687a097347303b616927eb9ff ("selftests: vDSO: build tests with O2 optimization")
https://git.kernel.org/cgit/linux/kernel/git/crng/random.git jd/arm64-vdso
in testcase: kernel-selftests
version: kernel-selftests-x86_64-977d51cf-1_20240508
with following parameters:
group: group-03
compiler: gcc-12
test machine: 36 threads 1 sockets Intel(R) Core(TM) i9-10980XE CPU @ 3.00GHz (Cascade Lake) with 32G memory
(please refer to attached dmesg/kmsg for entire log/backtrace)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <oliver.sang(a)intel.com>
| Closes: https://lore.kernel.org/oe-lkp/202409082121.553d4c89-oliver.sang@intel.com
# timeout set to 300
# selftests: vDSO: vdso_standalone_test_x86
# Segmentation fault
not ok 5 selftests: vDSO: vdso_standalone_test_x86 # exit=139
The kernel config and materials to reproduce are available at:
https://download.01.org/0day-ci/archive/20240908/202409082121.553d4c89-oliv…
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
Create a test for the robust list mechanism.
Signed-off-by: André Almeida <andrealmeid(a)igalia.com>
---
Changes from v1:
- Change futex type from int to _Atomic(unsigned int)
- Use old futex(FUTEX_WAIT) instead of the new sys_futex_wait()
---
.../selftests/futex/functional/.gitignore | 1 +
.../selftests/futex/functional/Makefile | 3 +-
.../selftests/futex/functional/robust_list.c | 448 ++++++++++++++++++
3 files changed, 451 insertions(+), 1 deletion(-)
create mode 100644 tools/testing/selftests/futex/functional/robust_list.c
diff --git a/tools/testing/selftests/futex/functional/.gitignore b/tools/testing/selftests/futex/functional/.gitignore
index fbcbdb6963b3..4726e1be7497 100644
--- a/tools/testing/selftests/futex/functional/.gitignore
+++ b/tools/testing/selftests/futex/functional/.gitignore
@@ -9,3 +9,4 @@ futex_wait_wouldblock
futex_wait
futex_requeue
futex_waitv
+robust_list
diff --git a/tools/testing/selftests/futex/functional/Makefile b/tools/testing/selftests/futex/functional/Makefile
index f79f9bac7918..b8635a1ac7f6 100644
--- a/tools/testing/selftests/futex/functional/Makefile
+++ b/tools/testing/selftests/futex/functional/Makefile
@@ -17,7 +17,8 @@ TEST_GEN_PROGS := \
futex_wait_private_mapped_file \
futex_wait \
futex_requeue \
- futex_waitv
+ futex_waitv \
+ robust_list
TEST_PROGS := run.sh
diff --git a/tools/testing/selftests/futex/functional/robust_list.c b/tools/testing/selftests/futex/functional/robust_list.c
new file mode 100644
index 000000000000..9308eb189d48
--- /dev/null
+++ b/tools/testing/selftests/futex/functional/robust_list.c
@@ -0,0 +1,448 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2024 Igalia S.L.
+ *
+ * Robust list test by André Almeida <andrealmeid(a)igalia.com>
+ *
+ * The robust list uAPI allows userspace to create "robust" locks, in the sense
+ * that if the lock holder thread dies, the remaining threads that are waiting
+ * for the lock won't block forever, waiting for a lock that will never be
+ * released.
+ *
+ * This is achieve by userspace setting a list where a thread can enter all the
+ * locks (futexes) that it is holding. The robust list is a linked list, and
+ * userspace register the start of the list with the syscall set_robust_list().
+ * If such thread eventually dies, the kernel will walk this list, waking up one
+ * thread waiting for each futex and marking the futex word with the flag
+ * FUTEX_OWNER_DIED.
+ *
+ * See also
+ * man set_robust_list
+ * Documententation/locking/robust-futex-ABI.rst
+ * Documententation/locking/robust-futexes.rst
+ */
+
+#define _GNU_SOURCE
+
+#include "../../kselftest_harness.h"
+
+#include "futextest.h"
+
+#include <pthread.h>
+#include <stdatomic.h>
+#include <stddef.h>
+
+#define STACK_SIZE (1024 * 1024)
+
+#define FUTEX_TIMEOUT 3
+
+static pthread_barrier_t barrier, barrier2;
+
+int set_robust_list(struct robust_list_head *head, size_t len)
+{
+ return syscall(SYS_set_robust_list, head, len);
+}
+
+int get_robust_list(int pid, struct robust_list_head **head, size_t *len_ptr)
+{
+ return syscall(SYS_get_robust_list, pid, head, len_ptr);
+}
+
+/*
+ * Basic lock struct, contains just the futex word and the robust list element
+ * Real implementations have also a *prev to easily walk in the list
+ */
+struct lock_struct {
+ _Atomic(unsigned int) futex;
+ struct robust_list list;
+};
+
+/*
+ * Helper function to spawn a child thread. Returns -1 on error, pid on success
+ */
+static int create_child(int (*fn)(void *arg), void *arg)
+{
+ char *stack;
+ pid_t pid;
+
+ stack = mmap(NULL, STACK_SIZE, PROT_READ | PROT_WRITE,
+ MAP_PRIVATE | MAP_ANONYMOUS | MAP_STACK, -1, 0);
+ if (stack == MAP_FAILED)
+ return -1;
+
+ stack += STACK_SIZE;
+
+ pid = clone(fn, stack, CLONE_VM | SIGCHLD, arg);
+
+ if (pid == -1)
+ return -1;
+
+ return pid;
+}
+
+/*
+ * Helper function to prepare and register a robust list
+ */
+static int set_list(struct robust_list_head *head)
+{
+ int ret;
+
+ ret = set_robust_list(head, sizeof(struct robust_list_head));
+ if (ret)
+ return ret;
+
+ head->futex_offset = (size_t) offsetof(struct lock_struct, futex) -
+ (size_t) offsetof(struct lock_struct, list);
+ head->list.next = &head->list;
+ head->list_op_pending = NULL;
+
+ return 0;
+}
+
+/*
+ * A basic (and incomplete) mutex lock function with robustness
+ */
+static int mutex_lock(struct lock_struct *lock, struct robust_list_head *head, bool error_inject)
+{
+ _Atomic(unsigned int) *futex = &lock->futex;
+ int zero = 0, ret = -1;
+ pid_t tid = gettid();
+
+ /*
+ * Set list_op_pending before starting the lock, so the kernel can catch
+ * the case where the thread died during the lock operation
+ */
+ head->list_op_pending = &lock->list;
+
+ if (atomic_compare_exchange_strong(futex, &zero, tid)) {
+ /*
+ * We took the lock, insert it in the robust list
+ */
+ struct robust_list *list = &head->list;
+
+ /* Error injection to test list_op_pending */
+ if (error_inject)
+ return 0;
+
+ while (list->next != &head->list)
+ list = list->next;
+
+ list->next = &lock->list;
+ lock->list.next = &head->list;
+
+ ret = 0;
+ } else {
+ /*
+ * We didn't take the lock, wait until the owner wakes (or dies)
+ */
+ struct timespec to;
+
+ clock_gettime(CLOCK_MONOTONIC, &to);
+ to.tv_sec = to.tv_sec + FUTEX_TIMEOUT;
+
+ tid = atomic_load(futex);
+ /* Kernel ignores futexes without the waiters flag */
+ tid |= FUTEX_WAITERS;
+ atomic_store(futex, tid);
+
+ ret = futex_wait((futex_t *) futex, tid, &to, 0);
+
+ /*
+ * A real mutex_lock() implementation would loop here to finally
+ * take the lock. We don't care about that, so we stop here.
+ */
+ }
+
+ head->list_op_pending = NULL;
+
+ return ret;
+}
+
+/*
+ * This child thread will succeed taking the lock, and then will exit holding it
+ */
+static int child_fn_lock(void *arg)
+{
+ struct lock_struct *lock = (struct lock_struct *) arg;
+ struct robust_list_head head;
+ int ret;
+
+ ret = set_list(&head);
+ if (ret)
+ ksft_test_result_fail("set_robust_list error\n");
+
+ ret = mutex_lock(lock, &head, false);
+ if (ret)
+ ksft_test_result_fail("mutex_lock error\n");
+
+ pthread_barrier_wait(&barrier);
+
+ /*
+ * There's a race here: the parent thread needs to be inside
+ * futex_wait() before the child thread dies, otherwise it will miss the
+ * wakeup from handle_futex_death() that this child will emit. We wait a
+ * little bit just to make sure that this happens.
+ */
+ sleep(1);
+
+ return 0;
+}
+
+/*
+ * Spawns a child thread that will set a robust list, take the lock, register it
+ * in the robust list and die. The parent thread will wait on this futex, and
+ * should be waken up when the child exits.
+ */
+TEST(robustness)
+{
+ struct lock_struct lock = { .futex = 0 };
+ struct robust_list_head head;
+ _Atomic(unsigned int) *futex = &lock.futex;
+ int ret;
+
+ ret = set_list(&head);
+ ASSERT_EQ(ret, 0);
+
+ /*
+ * Lets use a barrier to ensure that the child thread takes the lock
+ * before the parent
+ */
+ ret = pthread_barrier_init(&barrier, NULL, 2);
+ ASSERT_EQ(ret, 0);
+
+ ret = create_child(&child_fn_lock, &lock);
+ ASSERT_NE(ret, -1);
+
+ pthread_barrier_wait(&barrier);
+ ret = mutex_lock(&lock, &head, false);
+
+ /*
+ * futex_wait() should return 0 and the futex word should be marked with
+ * FUTEX_OWNER_DIED
+ */
+ ASSERT_EQ(ret, 0) TH_LOG("futex wait returned %d", errno);
+ ASSERT_TRUE(*futex | FUTEX_OWNER_DIED);
+
+ pthread_barrier_destroy(&barrier);
+}
+
+/*
+ * The only valid value for len is sizeof(*head)
+ */
+TEST(set_robust_list_invalid_size)
+{
+ struct robust_list_head head;
+ size_t head_size = sizeof(struct robust_list_head);
+ int ret;
+
+ ret = set_robust_list(&head, head_size);
+ ASSERT_EQ(ret, 0);
+
+ ret = set_robust_list(&head, head_size * 2);
+ ASSERT_EQ(ret, -1);
+ ASSERT_EQ(errno, EINVAL);
+
+ ret = set_robust_list(&head, head_size - 1);
+ ASSERT_EQ(ret, -1);
+ ASSERT_EQ(errno, EINVAL);
+
+ ret = set_robust_list(&head, 0);
+ ASSERT_EQ(ret, -1);
+ ASSERT_EQ(errno, EINVAL);
+}
+
+/*
+ * Test get_robust_list with pid = 0, getting the list of the running thread
+ */
+TEST(get_robust_list_self)
+{
+ struct robust_list_head head, head2, *get_head;
+ size_t head_size = sizeof(struct robust_list_head), len_ptr;
+ int ret;
+
+ ret = set_robust_list(&head, head_size);
+ ASSERT_EQ(ret, 0);
+
+ ret = get_robust_list(0, &get_head, &len_ptr);
+ ASSERT_EQ(ret, 0);
+ ASSERT_EQ(get_head, &head);
+ ASSERT_EQ(head_size, len_ptr);
+
+ ret = set_robust_list(&head2, head_size);
+ ASSERT_EQ(ret, 0);
+
+ ret = get_robust_list(0, &get_head, &len_ptr);
+ ASSERT_EQ(ret, 0);
+ ASSERT_EQ(get_head, &head2);
+ ASSERT_EQ(head_size, len_ptr);
+}
+
+static int child_list(void *arg)
+{
+ struct robust_list_head *head = (struct robust_list_head *) arg;
+ int ret;
+
+ ret = set_robust_list(head, sizeof(struct robust_list_head));
+ if (ret)
+ ksft_test_result_fail("set_robust_list error\n");
+
+ pthread_barrier_wait(&barrier);
+ pthread_barrier_wait(&barrier2);
+
+ return 0;
+}
+
+/*
+ * Test get_robust_list from another thread. We use two barriers here to ensure
+ * that:
+ * 1) the child thread set the list before we try to get it from the
+ * parent
+ * 2) the child thread still alive when we try to get the list from it
+ */
+TEST(get_robust_list_child)
+{
+ pid_t tid;
+ int ret;
+ struct robust_list_head head, *get_head;
+ size_t len_ptr;
+
+ ret = pthread_barrier_init(&barrier, NULL, 2);
+ ret = pthread_barrier_init(&barrier2, NULL, 2);
+ ASSERT_EQ(ret, 0);
+
+ tid = create_child(&child_list, &head);
+ ASSERT_NE(tid, -1);
+
+ pthread_barrier_wait(&barrier);
+
+ ret = get_robust_list(tid, &get_head, &len_ptr);
+ ASSERT_EQ(ret, 0);
+ ASSERT_EQ(&head, get_head);
+
+ pthread_barrier_wait(&barrier2);
+
+ pthread_barrier_destroy(&barrier);
+ pthread_barrier_destroy(&barrier2);
+}
+
+static int child_fn_lock_with_error(void *arg)
+{
+ struct lock_struct *lock = (struct lock_struct *) arg;
+ struct robust_list_head head;
+ int ret;
+
+ ret = set_list(&head);
+ if (ret)
+ ksft_test_result_fail("set_robust_list error\n");
+
+ ret = mutex_lock(lock, &head, true);
+ if (ret)
+ ksft_test_result_fail("mutex_lock error\n");
+
+ pthread_barrier_wait(&barrier);
+
+ sleep(1);
+
+ return 0;
+}
+
+/*
+ * Same as robustness test, but inject an error where the mutex_lock() exits
+ * earlier, just after setting list_op_pending and taking the lock, to test the
+ * list_op_pending mechanism
+ */
+TEST(set_list_op_pending)
+{
+ struct lock_struct lock = { .futex = 0 };
+ struct robust_list_head head;
+ _Atomic(unsigned int) *futex = &lock.futex;
+ int ret;
+
+ ret = set_list(&head);
+ ASSERT_EQ(ret, 0);
+
+ ret = pthread_barrier_init(&barrier, NULL, 2);
+ ASSERT_EQ(ret, 0);
+
+ ret = create_child(&child_fn_lock_with_error, &lock);
+ ASSERT_NE(ret, -1);
+
+ pthread_barrier_wait(&barrier);
+ ret = mutex_lock(&lock, &head, false);
+
+ ASSERT_EQ(ret, 0) TH_LOG("futex wait returned %d", errno);
+ ASSERT_TRUE(*futex | FUTEX_OWNER_DIED);
+
+ pthread_barrier_destroy(&barrier);
+}
+
+#define CHILD_NR 10
+
+static int child_lock_holder(void *arg)
+{
+ struct lock_struct *locks = (struct lock_struct *) arg;
+ struct robust_list_head head;
+ int i;
+
+ set_list(&head);
+
+ for (i = 0; i < CHILD_NR; i++) {
+ locks[i].futex = 0;
+ mutex_lock(&locks[i], &head, false);
+ }
+
+ pthread_barrier_wait(&barrier);
+ pthread_barrier_wait(&barrier2);
+
+ sleep(1);
+ return 0;
+}
+
+static int child_wait_lock(void *arg)
+{
+ struct lock_struct *lock = (struct lock_struct *) arg;
+ struct robust_list_head head;
+ int ret;
+
+ pthread_barrier_wait(&barrier2);
+ ret = mutex_lock(lock, &head, false);
+
+ if (ret)
+ ksft_test_result_fail("mutex_lock error\n");
+
+ if (!(lock->futex | FUTEX_OWNER_DIED))
+ ksft_test_result_fail("futex not marked with FUTEX_OWNER_DIED\n");
+
+ return 0;
+}
+
+/*
+ * Test a robust list of more than one element. All the waiters should wake when
+ * the holder dies
+ */
+TEST(robust_list_multiple_elements)
+{
+ struct lock_struct locks[CHILD_NR];
+ int i, ret;
+
+ ret = pthread_barrier_init(&barrier, NULL, 2);
+ ASSERT_EQ(ret, 0);
+ ret = pthread_barrier_init(&barrier2, NULL, CHILD_NR + 1);
+ ASSERT_EQ(ret, 0);
+
+ create_child(&child_lock_holder, &locks);
+
+ /* Wait until the locker thread takes the look */
+ pthread_barrier_wait(&barrier);
+
+ for (i = 0; i < CHILD_NR; i++)
+ create_child(&child_wait_lock, &locks[i]);
+
+ /* Wait for all children to return */
+ while (wait(NULL) > 0);
+
+ pthread_barrier_destroy(&barrier);
+ pthread_barrier_destroy(&barrier2);
+}
+
+TEST_HARNESS_MAIN
--
2.46.0
Thank you for the review, I have added the changelog as requested.
Changelog:
- Added missing newline to the `ksft_print_msg` in `test_zswap_writeback` function.
Signed-off-by: Mohammed Anees <pvmohammedanees2003(a)gmail.com>
---
tools/testing/selftests/cgroup/test_zswap.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/cgroup/test_zswap.c b/tools/testing/selftests/cgroup/test_zswap.c
index 190096017..7c849d836 100644
--- a/tools/testing/selftests/cgroup/test_zswap.c
+++ b/tools/testing/selftests/cgroup/test_zswap.c
@@ -351,7 +351,7 @@ static int test_zswap_writeback(const char *root, bool wb)
goto out;
if (wb != !!zswpwb_after) {
- ksft_print_msg("zswpwb_after is %ld while wb is %s",
+ ksft_print_msg("zswpwb_after is %ld while wb is %s\n",
zswpwb_after, wb ? "enabled" : "disabled");
goto out;
}
--
2.43.0
Hi Linus,
Please pull the following KUnit fixes second update for Linux 6.11-rc7.
This KUnit fixes update for Linux 6.11-rc7 consists of a fix to
missing function parameter warning found during documentation
build in linux-next.
diff is attached.
thanks,
-- Shuah
----------------------------------------------------------------
The following changes since commit f2c6dbd220170c2396fb019ead67fbada1e23ebd:
kunit: Device wrappers should also manage driver name (2024-08-26 07:03:46 -0600)
are available in the Git repository at:
git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest tags/linux_kselftest-kunit-fixes-6.11-rc7-2
for you to fetch changes up to 12cb32a52eb607dc4d0e45fe6f4cf946d08da0fd:
kunit: Fix missing kerneldoc comment (2024-09-05 14:29:10 -0600)
----------------------------------------------------------------
linux_kselftest-kunit-fixes-6.11-rc7-2
This KUnit fixes update for Linux 6.11-rc7 consists of a fix to
missing function parameter warning found during documentation
build in linux-next.
----------------------------------------------------------------
David Gow (1):
kunit: Fix missing kerneldoc comment
include/kunit/test.h | 1 +
1 file changed, 1 insertion(+)
----------------------------------------------------------------
rxq contains a pointer to the device from where
the redirect happened. Currently, the BPF program
that was executed after a redirect via BPF_MAP_TYPE_DEVMAP*
does not have it set.
Add bugfix and related selftest.
Signed-off-by: Florian Kauer <florian.kauer(a)linutronix.de>
---
Changes in v2:
- changed fixes tag
- added selftest
- Link to v1: https://lore.kernel.org/r/20240905-devel-koalo-fix-ingress-ifindex-v1-1-d12…
---
Florian Kauer (2):
bpf: devmap: provide rxq after redirect
bpf: selftests: send packet to devmap redirect XDP
kernel/bpf/devmap.c | 11 +-
.../selftests/bpf/prog_tests/xdp_devmap_attach.c | 114 +++++++++++++++++++--
2 files changed, 115 insertions(+), 10 deletions(-)
---
base-commit: 8e69c96df771ab469cec278edb47009351de4da6
change-id: 20240905-devel-koalo-fix-ingress-ifindex-b9293d471db6
Best regards,
--
Florian Kauer <florian.kauer(a)linutronix.de>
While kunit/visibility.h is today not included in any generated
kernel documentation, also likely due to the fact that none of the
existing comments are correctly recognized as kernel-doc, but once
we decide to add this header and fix the tool, there will be:
../include/kunit/visibility.h:61: warning: Function parameter or
struct member 'symbol' not described in 'EXPORT_SYMBOL_IF_KUNIT'
Signed-off-by: Michal Wajdeczko <michal.wajdeczko(a)intel.com>
---
Cc: Rae Moar <rmoar(a)google.com>
Cc: David Gow <davidgow(a)google.com>
---
include/kunit/visibility.h | 1 +
1 file changed, 1 insertion(+)
diff --git a/include/kunit/visibility.h b/include/kunit/visibility.h
index 0dfe35feeec6..efff77b58dd6 100644
--- a/include/kunit/visibility.h
+++ b/include/kunit/visibility.h
@@ -22,6 +22,7 @@
* EXPORTED_FOR_KUNIT_TESTING namespace only if CONFIG_KUNIT is
* enabled. Must use MODULE_IMPORT_NS(EXPORTED_FOR_KUNIT_TESTING)
* in test file in order to use symbols.
+ * @symbol: the symbol identifier to export
*/
#define EXPORT_SYMBOL_IF_KUNIT(symbol) EXPORT_SYMBOL_NS(symbol, \
EXPORTED_FOR_KUNIT_TESTING)
--
2.43.0