diff options
| -rw-r--r-- | include/linux/bpf.h | 1 | ||||
| -rw-r--r-- | include/uapi/linux/bpf.h | 13 | ||||
| -rw-r--r-- | kernel/bpf/core.c | 1 | ||||
| -rw-r--r-- | kernel/bpf/helpers.c | 14 | ||||
| -rw-r--r-- | tools/include/uapi/linux/bpf.h | 13 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/prog_tests/time_tai.c | 74 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/progs/test_time_tai.c | 24 |
7 files changed, 140 insertions, 0 deletions
diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 20c26aed7896..a627a02cf8ab 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -2349,6 +2349,7 @@ extern const struct bpf_func_proto bpf_get_numa_node_id_proto; extern const struct bpf_func_proto bpf_tail_call_proto; extern const struct bpf_func_proto bpf_ktime_get_ns_proto; extern const struct bpf_func_proto bpf_ktime_get_boot_ns_proto; +extern const struct bpf_func_proto bpf_ktime_get_tai_ns_proto; extern const struct bpf_func_proto bpf_get_current_pid_tgid_proto; extern const struct bpf_func_proto bpf_get_current_uid_gid_proto; extern const struct bpf_func_proto bpf_get_current_comm_proto; diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 534e33fb1029..7d1e2794d83e 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -5341,6 +5341,18 @@ union bpf_attr { * **-EACCES** if the SYN cookie is not valid. * * **-EPROTONOSUPPORT** if CONFIG_IPV6 is not builtin. + * + * u64 bpf_ktime_get_tai_ns(void) + * Description + * A nonsettable system-wide clock derived from wall-clock time but + * ignoring leap seconds. This clock does not experience + * discontinuities and backwards jumps caused by NTP inserting leap + * seconds as CLOCK_REALTIME does. + * + * See: **clock_gettime**\ (**CLOCK_TAI**) + * Return + * Current *ktime*. + * */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -5551,6 +5563,7 @@ union bpf_attr { FN(tcp_raw_gen_syncookie_ipv6), \ FN(tcp_raw_check_syncookie_ipv4), \ FN(tcp_raw_check_syncookie_ipv6), \ + FN(ktime_get_tai_ns), \ /* */ /* integer value in 'imm' field of BPF_CALL instruction selects which helper diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index c1e10d088dbb..639437f36928 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -2623,6 +2623,7 @@ const struct bpf_func_proto bpf_get_numa_node_id_proto __weak; const struct bpf_func_proto bpf_ktime_get_ns_proto __weak; const struct bpf_func_proto bpf_ktime_get_boot_ns_proto __weak; const struct bpf_func_proto bpf_ktime_get_coarse_ns_proto __weak; +const struct bpf_func_proto bpf_ktime_get_tai_ns_proto __weak; const struct bpf_func_proto bpf_get_current_pid_tgid_proto __weak; const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak; diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index 1f961f9982d2..a95eb9fb01ff 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -198,6 +198,18 @@ const struct bpf_func_proto bpf_ktime_get_coarse_ns_proto = { .ret_type = RET_INTEGER, }; +BPF_CALL_0(bpf_ktime_get_tai_ns) +{ + /* NMI safe access to clock tai */ + return ktime_get_tai_fast_ns(); +} + +const struct bpf_func_proto bpf_ktime_get_tai_ns_proto = { + .func = bpf_ktime_get_tai_ns, + .gpl_only = false, + .ret_type = RET_INTEGER, +}; + BPF_CALL_0(bpf_get_current_pid_tgid) { struct task_struct *task = current; @@ -1617,6 +1629,8 @@ bpf_base_func_proto(enum bpf_func_id func_id) return &bpf_ktime_get_ns_proto; case BPF_FUNC_ktime_get_boot_ns: return &bpf_ktime_get_boot_ns_proto; + case BPF_FUNC_ktime_get_tai_ns: + return &bpf_ktime_get_tai_ns_proto; case BPF_FUNC_ringbuf_output: return &bpf_ringbuf_output_proto; case BPF_FUNC_ringbuf_reserve: diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index f58d58e1d547..e174ad28aeb7 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -5341,6 +5341,18 @@ union bpf_attr { * **-EACCES** if the SYN cookie is not valid. * * **-EPROTONOSUPPORT** if CONFIG_IPV6 is not builtin. + * + * u64 bpf_ktime_get_tai_ns(void) + * Description + * A nonsettable system-wide clock derived from wall-clock time but + * ignoring leap seconds. This clock does not experience + * discontinuities and backwards jumps caused by NTP inserting leap + * seconds as CLOCK_REALTIME does. + * + * See: **clock_gettime**\ (**CLOCK_TAI**) + * Return + * Current *ktime*. + * */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -5551,6 +5563,7 @@ union bpf_attr { FN(tcp_raw_gen_syncookie_ipv6), \ FN(tcp_raw_check_syncookie_ipv4), \ FN(tcp_raw_check_syncookie_ipv6), \ + FN(ktime_get_tai_ns), \ /* */ /* integer value in 'imm' field of BPF_CALL instruction selects which helper diff --git a/tools/testing/selftests/bpf/prog_tests/time_tai.c b/tools/testing/selftests/bpf/prog_tests/time_tai.c new file mode 100644 index 000000000000..a31119823666 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/time_tai.c @@ -0,0 +1,74 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (C) 2022 Linutronix GmbH */ + +#include <test_progs.h> +#include <network_helpers.h> + +#include "test_time_tai.skel.h" + +#include <time.h> +#include <stdint.h> + +#define TAI_THRESHOLD 1000000000ULL /* 1s */ +#define NSEC_PER_SEC 1000000000ULL + +static __u64 ts_to_ns(const struct timespec *ts) +{ + return ts->tv_sec * NSEC_PER_SEC + ts->tv_nsec; +} + +void test_time_tai(void) +{ + struct __sk_buff skb = { + .cb[0] = 0, + .cb[1] = 0, + .tstamp = 0, + }; + LIBBPF_OPTS(bpf_test_run_opts, topts, + .data_in = &pkt_v4, + .data_size_in = sizeof(pkt_v4), + .ctx_in = &skb, + .ctx_size_in = sizeof(skb), + .ctx_out = &skb, + .ctx_size_out = sizeof(skb), + ); + struct test_time_tai *skel; + struct timespec now_tai; + __u64 ts1, ts2, now; + int ret, prog_fd; + + /* Open and load */ + skel = test_time_tai__open_and_load(); + if (!ASSERT_OK_PTR(skel, "tai_open")) + return; + + /* Run test program */ + prog_fd = bpf_program__fd(skel->progs.time_tai); + ret = bpf_prog_test_run_opts(prog_fd, &topts); + ASSERT_OK(ret, "test_run"); + + /* Retrieve generated TAI timestamps */ + ts1 = skb.tstamp; + ts2 = skb.cb[0] | ((__u64)skb.cb[1] << 32); + + /* TAI != 0 */ + ASSERT_NEQ(ts1, 0, "tai_ts1"); + ASSERT_NEQ(ts2, 0, "tai_ts2"); + + /* TAI is moving forward only */ + ASSERT_GT(ts2, ts1, "tai_forward"); + + /* Check for future */ + ret = clock_gettime(CLOCK_TAI, &now_tai); + ASSERT_EQ(ret, 0, "tai_gettime"); + now = ts_to_ns(&now_tai); + + ASSERT_TRUE(now > ts1, "tai_future_ts1"); + ASSERT_TRUE(now > ts2, "tai_future_ts2"); + + /* Check for reasonable range */ + ASSERT_TRUE(now - ts1 < TAI_THRESHOLD, "tai_range_ts1"); + ASSERT_TRUE(now - ts2 < TAI_THRESHOLD, "tai_range_ts2"); + + test_time_tai__destroy(skel); +} diff --git a/tools/testing/selftests/bpf/progs/test_time_tai.c b/tools/testing/selftests/bpf/progs/test_time_tai.c new file mode 100644 index 000000000000..7ea0863f3ddb --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_time_tai.c @@ -0,0 +1,24 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (C) 2022 Linutronix GmbH */ + +#include <linux/bpf.h> +#include <bpf/bpf_helpers.h> + +char _license[] SEC("license") = "GPL"; + +SEC("tc") +int time_tai(struct __sk_buff *skb) +{ + __u64 ts1, ts2; + + /* Get TAI timestamps */ + ts1 = bpf_ktime_get_tai_ns(); + ts2 = bpf_ktime_get_tai_ns(); + + /* Save TAI timestamps (Note: skb->hwtstamp is read-only) */ + skb->tstamp = ts1; + skb->cb[0] = ts2 & 0xffffffff; + skb->cb[1] = ts2 >> 32; + + return 0; +} |