Commit 16f0efc3 authored by Yonghong Song's avatar Yonghong Song Committed by Daniel Borkmann

tools/bpf: add selftest in test_progs for bpf_send_signal() helper

The test covered both nmi and tracepoint perf events.
  $ ./test_progs
  ...
  test_send_signal_tracepoint:PASS:tracepoint 0 nsec
  ...
  test_send_signal_common:PASS:tracepoint 0 nsec
  ...
  test_send_signal_common:PASS:perf_event 0 nsec
  ...
  test_send_signal:OK
Acked-by: default avatarAndrii Nakryiko <andriin@fb.com>
Signed-off-by: default avatarYonghong Song <yhs@fb.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
parent edaccf89
...@@ -224,6 +224,7 @@ static void *(*bpf_sk_storage_get)(void *map, struct bpf_sock *sk, ...@@ -224,6 +224,7 @@ static void *(*bpf_sk_storage_get)(void *map, struct bpf_sock *sk,
(void *) BPF_FUNC_sk_storage_get; (void *) BPF_FUNC_sk_storage_get;
static int (*bpf_sk_storage_delete)(void *map, struct bpf_sock *sk) = static int (*bpf_sk_storage_delete)(void *map, struct bpf_sock *sk) =
(void *)BPF_FUNC_sk_storage_delete; (void *)BPF_FUNC_sk_storage_delete;
static int (*bpf_send_signal)(unsigned sig) = (void *)BPF_FUNC_send_signal;
/* llvm builtin functions that eBPF C program may use to /* llvm builtin functions that eBPF C program may use to
* emit BPF_LD_ABS and BPF_LD_IND instructions * emit BPF_LD_ABS and BPF_LD_IND instructions
......
// SPDX-License-Identifier: GPL-2.0
#include <test_progs.h>
static volatile int sigusr1_received = 0;
static void sigusr1_handler(int signum)
{
sigusr1_received++;
}
static int test_send_signal_common(struct perf_event_attr *attr,
int prog_type,
const char *test_name)
{
int err = -1, pmu_fd, prog_fd, info_map_fd, status_map_fd;
const char *file = "./test_send_signal_kern.o";
struct bpf_object *obj = NULL;
int pipe_c2p[2], pipe_p2c[2];
__u32 key = 0, duration = 0;
char buf[256];
pid_t pid;
__u64 val;
if (CHECK(pipe(pipe_c2p), test_name,
"pipe pipe_c2p error: %s\n", strerror(errno)))
goto no_fork_done;
if (CHECK(pipe(pipe_p2c), test_name,
"pipe pipe_p2c error: %s\n", strerror(errno))) {
close(pipe_c2p[0]);
close(pipe_c2p[1]);
goto no_fork_done;
}
pid = fork();
if (CHECK(pid < 0, test_name, "fork error: %s\n", strerror(errno))) {
close(pipe_c2p[0]);
close(pipe_c2p[1]);
close(pipe_p2c[0]);
close(pipe_p2c[1]);
goto no_fork_done;
}
if (pid == 0) {
/* install signal handler and notify parent */
signal(SIGUSR1, sigusr1_handler);
close(pipe_c2p[0]); /* close read */
close(pipe_p2c[1]); /* close write */
/* notify parent signal handler is installed */
write(pipe_c2p[1], buf, 1);
/* make sure parent enabled bpf program to send_signal */
read(pipe_p2c[0], buf, 1);
/* wait a little for signal handler */
sleep(1);
if (sigusr1_received)
write(pipe_c2p[1], "2", 1);
else
write(pipe_c2p[1], "0", 1);
/* wait for parent notification and exit */
read(pipe_p2c[0], buf, 1);
close(pipe_c2p[1]);
close(pipe_p2c[0]);
exit(0);
}
close(pipe_c2p[1]); /* close write */
close(pipe_p2c[0]); /* close read */
err = bpf_prog_load(file, prog_type, &obj, &prog_fd);
if (CHECK(err < 0, test_name, "bpf_prog_load error: %s\n",
strerror(errno)))
goto prog_load_failure;
pmu_fd = syscall(__NR_perf_event_open, attr, pid, -1,
-1 /* group id */, 0 /* flags */);
if (CHECK(pmu_fd < 0, test_name, "perf_event_open error: %s\n",
strerror(errno))) {
err = -1;
goto close_prog;
}
err = ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0);
if (CHECK(err < 0, test_name, "ioctl perf_event_ioc_enable error: %s\n",
strerror(errno)))
goto disable_pmu;
err = ioctl(pmu_fd, PERF_EVENT_IOC_SET_BPF, prog_fd);
if (CHECK(err < 0, test_name, "ioctl perf_event_ioc_set_bpf error: %s\n",
strerror(errno)))
goto disable_pmu;
err = -1;
info_map_fd = bpf_object__find_map_fd_by_name(obj, "info_map");
if (CHECK(info_map_fd < 0, test_name, "find map %s error\n", "info_map"))
goto disable_pmu;
status_map_fd = bpf_object__find_map_fd_by_name(obj, "status_map");
if (CHECK(status_map_fd < 0, test_name, "find map %s error\n", "status_map"))
goto disable_pmu;
/* wait until child signal handler installed */
read(pipe_c2p[0], buf, 1);
/* trigger the bpf send_signal */
key = 0;
val = (((__u64)(SIGUSR1)) << 32) | pid;
bpf_map_update_elem(info_map_fd, &key, &val, 0);
/* notify child that bpf program can send_signal now */
write(pipe_p2c[1], buf, 1);
/* wait for result */
err = read(pipe_c2p[0], buf, 1);
if (CHECK(err < 0, test_name, "reading pipe error: %s\n", strerror(errno)))
goto disable_pmu;
if (CHECK(err == 0, test_name, "reading pipe error: size 0\n")) {
err = -1;
goto disable_pmu;
}
err = CHECK(buf[0] != '2', test_name, "incorrect result\n");
/* notify child safe to exit */
write(pipe_p2c[1], buf, 1);
disable_pmu:
close(pmu_fd);
close_prog:
bpf_object__close(obj);
prog_load_failure:
close(pipe_c2p[0]);
close(pipe_p2c[1]);
wait(NULL);
no_fork_done:
return err;
}
static int test_send_signal_tracepoint(void)
{
const char *id_path = "/sys/kernel/debug/tracing/events/syscalls/sys_enter_nanosleep/id";
struct perf_event_attr attr = {
.type = PERF_TYPE_TRACEPOINT,
.sample_type = PERF_SAMPLE_RAW | PERF_SAMPLE_CALLCHAIN,
.sample_period = 1,
.wakeup_events = 1,
};
__u32 duration = 0;
int bytes, efd;
char buf[256];
efd = open(id_path, O_RDONLY, 0);
if (CHECK(efd < 0, "tracepoint",
"open syscalls/sys_enter_nanosleep/id failure: %s\n",
strerror(errno)))
return -1;
bytes = read(efd, buf, sizeof(buf));
close(efd);
if (CHECK(bytes <= 0 || bytes >= sizeof(buf), "tracepoint",
"read syscalls/sys_enter_nanosleep/id failure: %s\n",
strerror(errno)))
return -1;
attr.config = strtol(buf, NULL, 0);
return test_send_signal_common(&attr, BPF_PROG_TYPE_TRACEPOINT, "tracepoint");
}
static int test_send_signal_nmi(void)
{
struct perf_event_attr attr = {
.sample_freq = 50,
.freq = 1,
.type = PERF_TYPE_HARDWARE,
.config = PERF_COUNT_HW_CPU_CYCLES,
};
return test_send_signal_common(&attr, BPF_PROG_TYPE_PERF_EVENT, "perf_event");
}
void test_send_signal(void)
{
int ret = 0;
ret |= test_send_signal_tracepoint();
ret |= test_send_signal_nmi();
if (!ret)
printf("test_send_signal:OK\n");
else
printf("test_send_signal:FAIL\n");
}
// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2019 Facebook
#include <linux/bpf.h>
#include <linux/version.h>
#include "bpf_helpers.h"
struct bpf_map_def SEC("maps") info_map = {
.type = BPF_MAP_TYPE_ARRAY,
.key_size = sizeof(__u32),
.value_size = sizeof(__u64),
.max_entries = 1,
};
BPF_ANNOTATE_KV_PAIR(info_map, __u32, __u64);
struct bpf_map_def SEC("maps") status_map = {
.type = BPF_MAP_TYPE_ARRAY,
.key_size = sizeof(__u32),
.value_size = sizeof(__u64),
.max_entries = 1,
};
BPF_ANNOTATE_KV_PAIR(status_map, __u32, __u64);
SEC("send_signal_demo")
int bpf_send_signal_test(void *ctx)
{
__u64 *info_val, *status_val;
__u32 key = 0, pid, sig;
int ret;
status_val = bpf_map_lookup_elem(&status_map, &key);
if (!status_val || *status_val != 0)
return 0;
info_val = bpf_map_lookup_elem(&info_map, &key);
if (!info_val || *info_val == 0)
return 0;
sig = *info_val >> 32;
pid = *info_val & 0xffffFFFF;
if ((bpf_get_current_pid_tgid() >> 32) == pid) {
ret = bpf_send_signal(sig);
if (ret == 0)
*status_val = 1;
}
return 0;
}
char __license[] SEC("license") = "GPL";
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