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Message-ID: <20171206220746.4038383-3-yhs@fb.com>
Date: Wed, 6 Dec 2017 14:07:46 -0800
From: Yonghong Song <yhs@...com>
To: <peterz@...radead.org>, <rostedt@...dmis.org>, <ast@...com>,
<daniel@...earbox.net>, <kafai@...com>, <netdev@...r.kernel.org>
CC: <kernel-team@...com>
Subject: [PATCH net-next v3 2/2] bpf/tracing: add a bpf test for new ioctl query interface
Added a subtest in test_progs. The tracepoint is
sched/sched_switch. Multiple bpf programs are attached to
this tracepoint and the query interface is exercised.
Signed-off-by: Yonghong Song <yhs@...com>
Acked-by: Alexei Starovoitov <ast@...nel.org>
---
tools/include/uapi/linux/perf_event.h | 22 +++++
tools/testing/selftests/bpf/Makefile | 2 +-
tools/testing/selftests/bpf/test_progs.c | 134 ++++++++++++++++++++++++++
tools/testing/selftests/bpf/test_tracepoint.c | 26 +++++
4 files changed, 183 insertions(+), 1 deletion(-)
create mode 100644 tools/testing/selftests/bpf/test_tracepoint.c
diff --git a/tools/include/uapi/linux/perf_event.h b/tools/include/uapi/linux/perf_event.h
index 362493a..f2c354d 100644
--- a/tools/include/uapi/linux/perf_event.h
+++ b/tools/include/uapi/linux/perf_event.h
@@ -418,6 +418,27 @@ struct perf_event_attr {
__u16 __reserved_2; /* align to __u64 */
};
+/*
+ * Structure used by below PERF_EVENT_IOC_QUERY_BPF command
+ * to query bpf programs attached to the same perf tracepoint
+ * as the given perf event.
+ */
+struct perf_event_query_bpf {
+ /*
+ * The below ids array length
+ */
+ __u32 ids_len;
+ /*
+ * Set by the kernel to indicate the number of
+ * available programs
+ */
+ __u32 prog_cnt;
+ /*
+ * User provided buffer to store program ids
+ */
+ __u32 ids[0];
+};
+
#define perf_flags(attr) (*(&(attr)->read_format + 1))
/*
@@ -433,6 +454,7 @@ struct perf_event_attr {
#define PERF_EVENT_IOC_ID _IOR('$', 7, __u64 *)
#define PERF_EVENT_IOC_SET_BPF _IOW('$', 8, __u32)
#define PERF_EVENT_IOC_PAUSE_OUTPUT _IOW('$', 9, __u32)
+#define PERF_EVENT_IOC_QUERY_BPF _IOWR('$', 10, struct perf_event_query_bpf *)
enum perf_event_ioc_flags {
PERF_IOC_FLAG_GROUP = 1U << 0,
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index 2c9d8c6..255fb1f 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -17,7 +17,7 @@ TEST_GEN_PROGS = test_verifier test_tag test_maps test_lru_map test_lpm_map test
TEST_GEN_FILES = test_pkt_access.o test_xdp.o test_l4lb.o test_tcp_estats.o test_obj_id.o \
test_pkt_md_access.o test_xdp_redirect.o test_xdp_meta.o sockmap_parse_prog.o \
- sockmap_verdict_prog.o dev_cgroup.o sample_ret0.o
+ sockmap_verdict_prog.o dev_cgroup.o sample_ret0.o test_tracepoint.o
TEST_PROGS := test_kmod.sh test_xdp_redirect.sh test_xdp_meta.sh \
test_offload.py
diff --git a/tools/testing/selftests/bpf/test_progs.c b/tools/testing/selftests/bpf/test_progs.c
index 6942753..1e0479a 100644
--- a/tools/testing/selftests/bpf/test_progs.c
+++ b/tools/testing/selftests/bpf/test_progs.c
@@ -21,8 +21,10 @@ typedef __u16 __sum16;
#include <linux/ipv6.h>
#include <linux/tcp.h>
#include <linux/filter.h>
+#include <linux/perf_event.h>
#include <linux/unistd.h>
+#include <sys/ioctl.h>
#include <sys/wait.h>
#include <sys/resource.h>
#include <sys/types.h>
@@ -617,6 +619,137 @@ static void test_obj_name(void)
}
}
+static void test_tp_attach_query(void)
+{
+ const int num_progs = 3;
+ int i, j, bytes, efd, err, prog_fd[num_progs], pmu_fd[num_progs];
+ __u32 duration = 0, info_len, saved_prog_ids[num_progs];
+ const char *file = "./test_tracepoint.o";
+ struct perf_event_query_bpf *query;
+ struct perf_event_attr attr = {};
+ struct bpf_object *obj[num_progs];
+ struct bpf_prog_info prog_info;
+ char buf[256];
+
+ snprintf(buf, sizeof(buf),
+ "/sys/kernel/debug/tracing/events/sched/sched_switch/id");
+ efd = open(buf, O_RDONLY, 0);
+ if (CHECK(efd < 0, "open", "err %d errno %d\n", efd, errno))
+ return;
+ bytes = read(efd, buf, sizeof(buf));
+ close(efd);
+ if (CHECK(bytes <= 0 || bytes >= sizeof(buf),
+ "read", "bytes %d errno %d\n", bytes, errno))
+ return;
+
+ attr.config = strtol(buf, NULL, 0);
+ attr.type = PERF_TYPE_TRACEPOINT;
+ attr.sample_type = PERF_SAMPLE_RAW | PERF_SAMPLE_CALLCHAIN;
+ attr.sample_period = 1;
+ attr.wakeup_events = 1;
+
+ query = (struct perf_event_query_bpf *)malloc(sizeof(struct perf_event_query_bpf) +
+ sizeof(__u32) * num_progs);
+ for (i = 0; i < num_progs; i++) {
+ err = bpf_prog_load(file, BPF_PROG_TYPE_TRACEPOINT, &obj[i],
+ &prog_fd[i]);
+ if (CHECK(err, "prog_load", "err %d errno %d\n", err, errno))
+ goto cleanup1;
+
+ bzero(&prog_info, sizeof(prog_info));
+ prog_info.jited_prog_len = 0;
+ prog_info.xlated_prog_len = 0;
+ prog_info.nr_map_ids = 0;
+ info_len = sizeof(prog_info);
+ err = bpf_obj_get_info_by_fd(prog_fd[i], &prog_info, &info_len);
+ if (CHECK(err, "bpf_obj_get_info_by_fd", "err %d errno %d\n",
+ err, errno))
+ goto cleanup1;
+ saved_prog_ids[i] = prog_info.id;
+
+ pmu_fd[i] = syscall(__NR_perf_event_open, &attr, -1 /* pid */,
+ 0 /* cpu 0 */, -1 /* group id */,
+ 0 /* flags */);
+ if (CHECK(pmu_fd[i] < 0, "perf_event_open", "err %d errno %d\n",
+ pmu_fd[i], errno))
+ goto cleanup2;
+ err = ioctl(pmu_fd[i], PERF_EVENT_IOC_ENABLE, 0);
+ if (CHECK(err, "perf_event_ioc_enable", "err %d errno %d\n",
+ err, errno))
+ goto cleanup3;
+
+ if (i == 0) {
+ /* check NULL prog array query */
+ query->ids_len = num_progs;
+ err = ioctl(pmu_fd[i], PERF_EVENT_IOC_QUERY_BPF, query);
+ if (CHECK(err || query->prog_cnt != 0,
+ "perf_event_ioc_query_bpf",
+ "err %d errno %d query->prog_cnt %u\n",
+ err, errno, query->prog_cnt))
+ goto cleanup3;
+ }
+
+ err = ioctl(pmu_fd[i], PERF_EVENT_IOC_SET_BPF, prog_fd[i]);
+ if (CHECK(err, "perf_event_ioc_set_bpf", "err %d errno %d\n",
+ err, errno))
+ goto cleanup3;
+
+ if (i == 1) {
+ /* try to get # of programs only */
+ query->ids_len = 0;
+ err = ioctl(pmu_fd[i], PERF_EVENT_IOC_QUERY_BPF, query);
+ if (CHECK(err || query->prog_cnt != 2,
+ "perf_event_ioc_query_bpf",
+ "err %d errno %d query->prog_cnt %u\n",
+ err, errno, query->prog_cnt))
+ goto cleanup3;
+
+ /* try a few negative tests */
+ /* invalid query pointer */
+ err = ioctl(pmu_fd[i], PERF_EVENT_IOC_QUERY_BPF,
+ (struct perf_event_query_bpf *)0x1);
+ if (CHECK(!err || errno != EFAULT,
+ "perf_event_ioc_query_bpf",
+ "err %d errno %d\n", err, errno))
+ goto cleanup3;
+
+ /* no enough space */
+ query->ids_len = 1;
+ err = ioctl(pmu_fd[i], PERF_EVENT_IOC_QUERY_BPF, query);
+ if (CHECK(!err || errno != ENOSPC || query->prog_cnt != 2,
+ "perf_event_ioc_query_bpf",
+ "err %d errno %d query->prog_cnt %u\n",
+ err, errno, query->prog_cnt))
+ goto cleanup3;
+ }
+
+ query->ids_len = num_progs;
+ err = ioctl(pmu_fd[i], PERF_EVENT_IOC_QUERY_BPF, query);
+ if (CHECK(err || query->prog_cnt != (i + 1),
+ "perf_event_ioc_query_bpf",
+ "err %d errno %d query->prog_cnt %u\n",
+ err, errno, query->prog_cnt))
+ goto cleanup3;
+ for (j = 0; j < i + 1; j++)
+ if (CHECK(saved_prog_ids[j] != query->ids[j],
+ "perf_event_ioc_query_bpf",
+ "#%d saved_prog_id %x query prog_id %x\n",
+ j, saved_prog_ids[j], query->ids[j]))
+ goto cleanup3;
+ }
+
+ i = num_progs - 1;
+ for (; i >= 0; i--) {
+ cleanup3:
+ ioctl(pmu_fd[i], PERF_EVENT_IOC_DISABLE);
+ cleanup2:
+ close(pmu_fd[i]);
+ cleanup1:
+ bpf_object__close(obj[i]);
+ }
+ free(query);
+}
+
int main(void)
{
struct rlimit rinf = { RLIM_INFINITY, RLIM_INFINITY };
@@ -630,6 +763,7 @@ int main(void)
test_bpf_obj_id();
test_pkt_md_access();
test_obj_name();
+ test_tp_attach_query();
printf("Summary: %d PASSED, %d FAILED\n", pass_cnt, error_cnt);
return error_cnt ? EXIT_FAILURE : EXIT_SUCCESS;
diff --git a/tools/testing/selftests/bpf/test_tracepoint.c b/tools/testing/selftests/bpf/test_tracepoint.c
new file mode 100644
index 0000000..04bf084
--- /dev/null
+++ b/tools/testing/selftests/bpf/test_tracepoint.c
@@ -0,0 +1,26 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2017 Facebook
+
+#include <linux/bpf.h>
+#include "bpf_helpers.h"
+
+/* taken from /sys/kernel/debug/tracing/events/sched/sched_switch/format */
+struct sched_switch_args {
+ unsigned long long pad;
+ char prev_comm[16];
+ int prev_pid;
+ int prev_prio;
+ long long prev_state;
+ char next_comm[16];
+ int next_pid;
+ int next_prio;
+};
+
+SEC("tracepoint/sched/sched_switch")
+int oncpu(struct sched_switch_args *ctx)
+{
+ return 0;
+}
+
+char _license[] SEC("license") = "GPL";
+__u32 _version SEC("version") = 1; /* ignored by tracepoints, required by libbpf.a */
--
2.9.5
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