NoaSoftware
/
TencentOS-kernel
forked from TencentOS/TencentOS-kernel
0
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

selftests/bpf: Switch perf_buffer test to tracepoint and skeleton 

[upstream commit 6984cbc6dfa280687367b9660d8c830518239851]

Switch perf_buffer test to use skeleton to avoid use of bpf_prog_load() and
make test a bit more succinct. Also switch BPF program to use tracepoint
instead of kprobe, as that allows to support older kernels, which had
tracepoint support before kprobe support in the form that libbpf expects
(i.e., libbpf expects /sys/bus/event_source/devices/kprobe/type, which doesn't
always exist on old kernels).

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200708015318.3827358-7-andriin@fb.com
This commit is contained in:
Andrii Nakryiko 2020-07-07 18:53:18 -07:00 committed by Menglong Dong
parent 3cd4ce36fd
commit 7f18fabdaa
2 changed files with 14 additions and 32 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

42
tools/testing/selftests/bpf/prog_tests/perf_buffer.c
View File

@ -4,6 +4,7 @@
#include <sched.h>
#include <sys/socket.h>
#include <test_progs.h>
#include "test_perf_buffer.skel.h"
#include "libbpf_internal.h"
static void on_sample(void *ctx, int cpu, void *data, __u32 size)
@ -20,16 +21,11 @@ static void on_sample(void *ctx, int cpu, void *data, __u32 size)
void test_perf_buffer(void)
{
int err, prog_fd, on_len, nr_on_cpus = 0, nr_cpus, i, duration = 0;
const char *prog_name = "kprobe/sys_nanosleep";
const char *file = "./test_perf_buffer.o";
int err, on_len, nr_on_cpus = 0, nr_cpus, i, duration = 0;
struct perf_buffer_opts pb_opts = {};
struct bpf_map *perf_buf_map;
struct test_perf_buffer *skel;
cpu_set_t cpu_set, cpu_seen;
struct bpf_program *prog;
struct bpf_object *obj;
struct perf_buffer *pb;
struct bpf_link *link;
bool *online;
nr_cpus = libbpf_num_possible_cpus();
@ -46,33 +42,21 @@ void test_perf_buffer(void)
nr_on_cpus++;
/* load program */
err = bpf_prog_load(file, BPF_PROG_TYPE_KPROBE, &obj, &prog_fd);
if (CHECK(err, "obj_load", "err %d errno %d\n", err, errno)) {
obj = NULL;
goto out_close;
}
prog = bpf_object__find_program_by_title(obj, prog_name);
if (CHECK(!prog, "find_probe", "prog '%s' not found\n", prog_name))
skel = test_perf_buffer__open_and_load();
if (CHECK(!skel, "skel_load", "skeleton open/load failed\n"))
goto out_close;
/* load map */
perf_buf_map = bpf_object__find_map_by_name(obj, "perf_buf_map");
if (CHECK(!perf_buf_map, "find_perf_buf_map", "not found\n"))
goto out_close;
/* attach kprobe */
link = bpf_program__attach_kprobe(prog, false /* retprobe */,
SYS_NANOSLEEP_KPROBE_NAME);
if (CHECK(IS_ERR(link), "attach_kprobe", "err %ld\n", PTR_ERR(link)))
/* attach probe */
err = test_perf_buffer__attach(skel);
if (CHECK(err, "attach_kprobe", "err %d\n", err))
goto out_close;
/* set up perf buffer */
pb_opts.sample_cb = on_sample;
pb_opts.ctx = &cpu_seen;
pb = perf_buffer__new(bpf_map__fd(perf_buf_map), 1, &pb_opts);
pb = perf_buffer__new(bpf_map__fd(skel->maps.perf_buf_map), 1, &pb_opts);
if (CHECK(IS_ERR(pb), "perf_buf__new", "err %ld\n", PTR_ERR(pb)))
goto out_detach;
goto out_close;
/* trigger kprobe on every CPU */
CPU_ZERO(&cpu_seen);
@ -89,7 +73,7 @@ void test_perf_buffer(void)
&cpu_set);
if (err && CHECK(err, "set_affinity", "cpu #%d, err %d\n",
i, err))
goto out_detach;
goto out_close;
usleep(1);
}
@ -105,9 +89,7 @@ void test_perf_buffer(void)
out_free_pb:
perf_buffer__free(pb);
out_detach:
bpf_link__destroy(link);
out_close:
bpf_object__close(obj);
test_perf_buffer__destroy(skel);
free(online);
}

4
tools/testing/selftests/bpf/progs/test_perf_buffer.c
View File

@ -11,8 +11,8 @@ struct {
__uint(value_size, sizeof(int));
} perf_buf_map SEC(".maps");
SEC("kprobe/sys_nanosleep")
int handle_sys_nanosleep_entry(struct pt_regs *ctx)
SEC("tp/raw_syscalls/sys_enter")
int handle_sys_enter(void *ctx)
{
int cpu = bpf_get_smp_processor_id();