On Mon, Jun 30, 2025 at 4:24 AM Jiri Olsa <olsajiri@xxxxxxxxx> wrote:
>
> On Fri, Jun 27, 2025 at 04:39:56PM -0700, Amery Hung wrote:
> > Test basic operations of task local data with valid and invalid
> > tld_create_key().
> >
> > For invalid calls, make sure they return the right error code and check
> > that the TLDs are not inserted by running tld_get_data("
> > value_not_exists") on the bpf side. The call should a null pointer.
> >
> > For valid calls, first make sure the TLDs are created by calling
> > tld_get_data() on the bpf side. The call should return a valid pointer.
> >
> > Finally, verify that the TLDs are indeed task-specific (i.e., their
> > addresses do not overlap) with multiple user threads. This done by
> > writing values unique to each thread, reading them from both user space
> > and bpf, and checking if the value read back matches the value written.
> >
> > Signed-off-by: Amery Hung <ameryhung@xxxxxxxxx>
> > ---
> > .../bpf/prog_tests/test_task_local_data.c | 191 ++++++++++++++++++
> > .../bpf/progs/test_task_local_data.c | 65 ++++++
> > 2 files changed, 256 insertions(+)
> > create mode 100644 tools/testing/selftests/bpf/prog_tests/test_task_local_data.c
> > create mode 100644 tools/testing/selftests/bpf/progs/test_task_local_data.c
> >
> > diff --git a/tools/testing/selftests/bpf/prog_tests/test_task_local_data.c b/tools/testing/selftests/bpf/prog_tests/test_task_local_data.c
> > new file mode 100644
> > index 000000000000..53cdb8466f8e
> > --- /dev/null
> > +++ b/tools/testing/selftests/bpf/prog_tests/test_task_local_data.c
> > @@ -0,0 +1,191 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +#include <pthread.h>
> > +#include <bpf/btf.h>
> > +#include <test_progs.h>
> > +
> > +struct test_struct {
> > + __u64 a;
> > + __u64 b;
> > + __u64 c;
> > + __u64 d;
> > +};
>
> hi,
> I can't compile this on my config, bacause of the KGDB_TESTS config
> that defines struct test_struct
>
> progs/test_task_local_data.c:16:8: error: redefinition of 'test_struct'
> 16 | struct test_struct {
> | ^
> /home/jolsa/kernel/linux-qemu-1/tools/testing/selftests/bpf/tools/include/vmlinux.h:141747:8: note: previous definition is here
> 141747 | struct test_struct {
>
>
> also I have these tests passing localy, but it's failing CI:
> https://github.com/kernel-patches/bpf/actions/runs/15939264078/job/44964987935
>
Thanks for reporting the error. I will change the test_struct name.
For the CI failure, I will fix it by changing the type of "off" in the
bpf tld_get_data() from int to s64.
Thanks,
Amery
> thanks,
> jirka
>
>
> > +
> > +#define TLD_FREE_DATA_ON_THREAD_EXIT
> > +#define TLD_DYN_DATA_SIZE 4096
> > +#include "task_local_data.h"
> > +
> > +#include "test_task_local_data.skel.h"
> > +
> > +TLD_DEFINE_KEY(value0_key, "value0", sizeof(int));
> > +
> > +/*
> > + * Reset task local data between subtests by clearing metadata. This is safe
> > + * as subtests run sequentially. Users of task local data libraries
> > + * should not do this.
> > + */
> > +static void reset_tld(void)
> > +{
> > + if (TLD_READ_ONCE(tld_metadata_p)) {
> > + /* Remove TLDs created by tld_create_key() */
> > + tld_metadata_p->cnt = 1;
> > + tld_metadata_p->size = TLD_DYN_DATA_SIZE;
> > + memset(&tld_metadata_p->metadata[1], 0,
> > + (TLD_MAX_DATA_CNT - 1) * sizeof(struct tld_metadata));
> > + }
> > +}
> > +
> > +/* Serialize access to bpf program's global variables */
> > +static pthread_mutex_t global_mutex;
> > +
> > +static tld_key_t *tld_keys;
> > +
> > +#define TEST_BASIC_THREAD_NUM TLD_MAX_DATA_CNT
> > +
> > +void *test_task_local_data_basic_thread(void *arg)
> > +{
> > + LIBBPF_OPTS(bpf_test_run_opts, opts);
> > + struct test_task_local_data *skel = (struct test_task_local_data *)arg;
> > + int fd, err, tid, *value0, *value1;
> > + struct test_struct *value2;
> > +
> > + fd = bpf_map__fd(skel->maps.tld_data_map);
> > +
> > + value0 = tld_get_data(fd, value0_key);
> > + if (!ASSERT_OK_PTR(value0, "tld_get_data"))
> > + goto out;
> > +
> > + value1 = tld_get_data(fd, tld_keys[0]);
> > + if (!ASSERT_OK_PTR(value1, "tld_get_data"))
> > + goto out;
> > +
> > + value2 = tld_get_data(fd, tld_keys[1]);
> > + if (!ASSERT_OK_PTR(value2, "tld_get_data"))
> > + goto out;
> > +
> > + tid = gettid();
> > +
> > + *value0 = tid + 0;
> > + *value1 = tid + 1;
> > + value2->a = tid + 2;
> > + value2->b = tid + 3;
> > + value2->c = tid + 4;
> > + value2->d = tid + 5;
> > +
> > + pthread_mutex_lock(&global_mutex);
> > + /* Run task_main that read task local data and save to global variables */
> > + err = bpf_prog_test_run_opts(bpf_program__fd(skel->progs.task_main), &opts);
> > + ASSERT_OK(err, "run task_main");
> > + ASSERT_OK(opts.retval, "task_main retval");
> > +
> > + ASSERT_EQ(skel->bss->test_value0, tid + 0, "tld_get_data value0");
> > + ASSERT_EQ(skel->bss->test_value1, tid + 1, "tld_get_data value1");
> > + ASSERT_EQ(skel->bss->test_value2.a, tid + 2, "tld_get_data value2.a");
> > + ASSERT_EQ(skel->bss->test_value2.b, tid + 3, "tld_get_data value2.b");
> > + ASSERT_EQ(skel->bss->test_value2.c, tid + 4, "tld_get_data value2.c");
> > + ASSERT_EQ(skel->bss->test_value2.d, tid + 5, "tld_get_data value2.d");
> > + pthread_mutex_unlock(&global_mutex);
> > +
> > + /* Make sure valueX are indeed local to threads */
> > + ASSERT_EQ(*value0, tid + 0, "value0");
> > + ASSERT_EQ(*value1, tid + 1, "value1");
> > + ASSERT_EQ(value2->a, tid + 2, "value2.a");
> > + ASSERT_EQ(value2->b, tid + 3, "value2.b");
> > + ASSERT_EQ(value2->c, tid + 4, "value2.c");
> > + ASSERT_EQ(value2->d, tid + 5, "value2.d");
> > +
> > + *value0 = tid + 5;
> > + *value1 = tid + 4;
> > + value2->a = tid + 3;
> > + value2->b = tid + 2;
> > + value2->c = tid + 1;
> > + value2->d = tid + 0;
> > +
> > + /* Run task_main again */
> > + pthread_mutex_lock(&global_mutex);
> > + err = bpf_prog_test_run_opts(bpf_program__fd(skel->progs.task_main), &opts);
> > + ASSERT_OK(err, "run task_main");
> > + ASSERT_OK(opts.retval, "task_main retval");
> > +
> > + ASSERT_EQ(skel->bss->test_value0, tid + 5, "tld_get_data value0");
> > + ASSERT_EQ(skel->bss->test_value1, tid + 4, "tld_get_data value1");
> > + ASSERT_EQ(skel->bss->test_value2.a, tid + 3, "tld_get_data value2.a");
> > + ASSERT_EQ(skel->bss->test_value2.b, tid + 2, "tld_get_data value2.b");
> > + ASSERT_EQ(skel->bss->test_value2.c, tid + 1, "tld_get_data value2.c");
> > + ASSERT_EQ(skel->bss->test_value2.d, tid + 0, "tld_get_data value2.d");
> > + pthread_mutex_unlock(&global_mutex);
> > +
> > +out:
> > + pthread_exit(NULL);
> > +}
> > +
> > +static void test_task_local_data_basic(void)
> > +{
> > + struct test_task_local_data *skel;
> > + pthread_t thread[TEST_BASIC_THREAD_NUM];
> > + char dummy_key_name[TLD_NAME_LEN];
> > + tld_key_t key;
> > + int i, err;
> > +
> > + reset_tld();
> > +
> > + ASSERT_OK(pthread_mutex_init(&global_mutex, NULL), "pthread_mutex_init");
> > +
> > + skel = test_task_local_data__open_and_load();
> > + if (!ASSERT_OK_PTR(skel, "skel_open_and_load"))
> > + return;
> > +
> > + tld_keys = calloc(TEST_BASIC_THREAD_NUM, sizeof(tld_key_t));
> > + if (!ASSERT_OK_PTR(tld_keys, "calloc tld_keys"))
> > + goto out;
> > +
> > + ASSERT_FALSE(tld_key_is_err(value0_key), "TLD_DEFINE_KEY");
> > + tld_keys[0] = tld_create_key("value1", sizeof(int));
> > + ASSERT_FALSE(tld_key_is_err(tld_keys[0]), "tld_create_key");
> > + tld_keys[1] = tld_create_key("value2", sizeof(struct test_struct));
> > + ASSERT_FALSE(tld_key_is_err(tld_keys[1]), "tld_create_key");
> > +
> > + /*
> > + * Shouldn't be able to store data exceed a page. Create a TLD just big
> > + * enough to exceed a page. TLDs already created are int value0, int
> > + * value1, and struct test_struct value2.
> > + */
> > + key = tld_create_key("value_not_exist",
> > + TLD_PAGE_SIZE - 2 * sizeof(int) - sizeof(struct test_struct) + 1);
> > + ASSERT_EQ(tld_key_err_or_zero(key), -E2BIG, "tld_create_key");
> > +
> > + key = tld_create_key("value2", sizeof(struct test_struct));
> > + ASSERT_EQ(tld_key_err_or_zero(key), -EEXIST, "tld_create_key");
> > +
> > + /* Shouldn't be able to create the (TLD_MAX_DATA_CNT+1)-th TLD */
> > + for (i = 3; i < TLD_MAX_DATA_CNT; i++) {
> > + snprintf(dummy_key_name, TLD_NAME_LEN, "dummy_value%d", i);
> > + tld_keys[i] = tld_create_key(dummy_key_name, sizeof(int));
> > + ASSERT_FALSE(tld_key_is_err(tld_keys[i]), "tld_create_key");
> > + }
> > + key = tld_create_key("value_not_exist", sizeof(struct test_struct));
> > + ASSERT_EQ(tld_key_err_or_zero(key), -ENOSPC, "tld_create_key");
> > +
> > + /* Access TLDs from multiple threads and check if they are thread-specific */
> > + for (i = 0; i < TEST_BASIC_THREAD_NUM; i++) {
> > + err = pthread_create(&thread[i], NULL, test_task_local_data_basic_thread, skel);
> > + if (!ASSERT_OK(err, "pthread_create"))
> > + goto out;
> > + }
> > +
> > +out:
> > + for (i = 0; i < TEST_BASIC_THREAD_NUM; i++)
> > + pthread_join(thread[i], NULL);
> > +
> > + if (tld_keys) {
> > + free(tld_keys);
> > + tld_keys = NULL;
> > + }
> > + tld_free();
> > + test_task_local_data__destroy(skel);
> > +}
> > +
> > +void test_task_local_data(void)
> > +{
> > + if (test__start_subtest("task_local_data_basic"))
> > + test_task_local_data_basic();
> > +}
> > diff --git a/tools/testing/selftests/bpf/progs/test_task_local_data.c b/tools/testing/selftests/bpf/progs/test_task_local_data.c
> > new file mode 100644
> > index 000000000000..94d1745dd8d4
> > --- /dev/null
> > +++ b/tools/testing/selftests/bpf/progs/test_task_local_data.c
> > @@ -0,0 +1,65 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +
> > +#include <vmlinux.h>
> > +#include <errno.h>
> > +#include <bpf/bpf_helpers.h>
> > +
> > +#include "task_local_data.bpf.h"
> > +
> > +struct tld_keys {
> > + tld_key_t value0;
> > + tld_key_t value1;
> > + tld_key_t value2;
> > + tld_key_t value_not_exist;
> > +};
> > +
> > +struct test_struct {
> > + unsigned long a;
> > + unsigned long b;
> > + unsigned long c;
> > + unsigned long d;
> > +};
> > +
> > +int test_value0;
> > +int test_value1;
> > +struct test_struct test_value2;
> > +
> > +SEC("syscall")
> > +int task_main(void *ctx)
> > +{
> > + struct tld_object tld_obj;
> > + struct test_struct *struct_p;
> > + struct task_struct *task;
> > + int err, *int_p;
> > +
> > + task = bpf_get_current_task_btf();
> > + err = tld_object_init(task, &tld_obj);
> > + if (err)
> > + return 1;
> > +
> > + int_p = tld_get_data(&tld_obj, value0, "value0", sizeof(int));
> > + if (int_p)
> > + test_value0 = *int_p;
> > + else
> > + return 2;
> > +
> > + int_p = tld_get_data(&tld_obj, value1, "value1", sizeof(int));
> > + if (int_p)
> > + test_value1 = *int_p;
> > + else
> > + return 3;
> > +
> > + struct_p = tld_get_data(&tld_obj, value2, "value2", sizeof(struct test_struct));
> > + if (struct_p)
> > + test_value2 = *struct_p;
> > + else
> > + return 4;
> > +
> > + int_p = tld_get_data(&tld_obj, value_not_exist, "value_not_exist", sizeof(int));
> > + if (int_p)
> > + return 5;
> > +
> > + return 0;
> > +}
> > +
> > +char _license[] SEC("license") = "GPL";
> > --
> > 2.47.1
> >
> >
