Commit 6879c042 authored by Yonghong Song's avatar Yonghong Song Committed by Alexei Starovoitov

tools/bpf: selftests: Add bpf_iter selftests

The added test includes the following subtests:
  - test verifier change for btf_id_or_null
  - test load/create_iter/read for
    ipv6_route/netlink/bpf_map/task/task_file
  - test anon bpf iterator
  - test anon bpf iterator reading one char at a time
  - test file bpf iterator
  - test overflow (single bpf program output not overflow)
  - test overflow (single bpf program output overflows)
  - test bpf prog returning 1

The ipv6_route tests the following verifier change
  - access fields in the variable length array of the structure.

The netlink load tests the following verifier change
  - put a btf_id ptr value in a stack and accessible to
    tracing/iter programs.

The anon bpf iterator also tests link auto attach through skeleton.

  $ test_progs -n 2
  #2/1 btf_id_or_null:OK
  #2/2 ipv6_route:OK
  #2/3 netlink:OK
  #2/4 bpf_map:OK
  #2/5 task:OK
  #2/6 task_file:OK
  #2/7 anon:OK
  #2/8 anon-read-one-char:OK
  #2/9 file:OK
  #2/10 overflow:OK
  #2/11 overflow-e2big:OK
  #2/12 prog-ret-1:OK
  #2 bpf_iter:OK
  Summary: 1/12 PASSED, 0 SKIPPED, 0 FAILED
Signed-off-by: default avatarYonghong Song <yhs@fb.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Acked-by: default avatarAndrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200509175923.2477637-1-yhs@fb.com
parent acf61631
// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2020 Facebook */
#include <test_progs.h>
#include "bpf_iter_ipv6_route.skel.h"
#include "bpf_iter_netlink.skel.h"
#include "bpf_iter_bpf_map.skel.h"
#include "bpf_iter_task.skel.h"
#include "bpf_iter_task_file.skel.h"
#include "bpf_iter_test_kern1.skel.h"
#include "bpf_iter_test_kern2.skel.h"
#include "bpf_iter_test_kern3.skel.h"
#include "bpf_iter_test_kern4.skel.h"
static int duration;
static void test_btf_id_or_null(void)
{
struct bpf_iter_test_kern3 *skel;
skel = bpf_iter_test_kern3__open_and_load();
if (CHECK(skel, "bpf_iter_test_kern3__open_and_load",
"skeleton open_and_load unexpectedly succeeded\n")) {
bpf_iter_test_kern3__destroy(skel);
return;
}
}
static void do_dummy_read(struct bpf_program *prog)
{
struct bpf_link *link;
char buf[16] = {};
int iter_fd, len;
link = bpf_program__attach_iter(prog, NULL);
if (CHECK(IS_ERR(link), "attach_iter", "attach_iter failed\n"))
return;
iter_fd = bpf_iter_create(bpf_link__fd(link));
if (CHECK(iter_fd < 0, "create_iter", "create_iter failed\n"))
goto free_link;
/* not check contents, but ensure read() ends without error */
while ((len = read(iter_fd, buf, sizeof(buf))) > 0)
;
CHECK(len < 0, "read", "read failed: %s\n", strerror(errno));
close(iter_fd);
free_link:
bpf_link__destroy(link);
}
static void test_ipv6_route(void)
{
struct bpf_iter_ipv6_route *skel;
skel = bpf_iter_ipv6_route__open_and_load();
if (CHECK(!skel, "bpf_iter_ipv6_route__open_and_load",
"skeleton open_and_load failed\n"))
return;
do_dummy_read(skel->progs.dump_ipv6_route);
bpf_iter_ipv6_route__destroy(skel);
}
static void test_netlink(void)
{
struct bpf_iter_netlink *skel;
skel = bpf_iter_netlink__open_and_load();
if (CHECK(!skel, "bpf_iter_netlink__open_and_load",
"skeleton open_and_load failed\n"))
return;
do_dummy_read(skel->progs.dump_netlink);
bpf_iter_netlink__destroy(skel);
}
static void test_bpf_map(void)
{
struct bpf_iter_bpf_map *skel;
skel = bpf_iter_bpf_map__open_and_load();
if (CHECK(!skel, "bpf_iter_bpf_map__open_and_load",
"skeleton open_and_load failed\n"))
return;
do_dummy_read(skel->progs.dump_bpf_map);
bpf_iter_bpf_map__destroy(skel);
}
static void test_task(void)
{
struct bpf_iter_task *skel;
skel = bpf_iter_task__open_and_load();
if (CHECK(!skel, "bpf_iter_task__open_and_load",
"skeleton open_and_load failed\n"))
return;
do_dummy_read(skel->progs.dump_task);
bpf_iter_task__destroy(skel);
}
static void test_task_file(void)
{
struct bpf_iter_task_file *skel;
skel = bpf_iter_task_file__open_and_load();
if (CHECK(!skel, "bpf_iter_task_file__open_and_load",
"skeleton open_and_load failed\n"))
return;
do_dummy_read(skel->progs.dump_task_file);
bpf_iter_task_file__destroy(skel);
}
/* The expected string is less than 16 bytes */
static int do_read_with_fd(int iter_fd, const char *expected,
bool read_one_char)
{
int err = -1, len, read_buf_len, start;
char buf[16] = {};
read_buf_len = read_one_char ? 1 : 16;
start = 0;
while ((len = read(iter_fd, buf + start, read_buf_len)) > 0) {
start += len;
if (CHECK(start >= 16, "read", "read len %d\n", len))
return -1;
read_buf_len = read_one_char ? 1 : 16 - start;
}
if (CHECK(len < 0, "read", "read failed: %s\n", strerror(errno)))
return -1;
err = strcmp(buf, expected);
if (CHECK(err, "read", "incorrect read result: buf %s, expected %s\n",
buf, expected))
return -1;
return 0;
}
static void test_anon_iter(bool read_one_char)
{
struct bpf_iter_test_kern1 *skel;
struct bpf_link *link;
int iter_fd, err;
skel = bpf_iter_test_kern1__open_and_load();
if (CHECK(!skel, "bpf_iter_test_kern1__open_and_load",
"skeleton open_and_load failed\n"))
return;
err = bpf_iter_test_kern1__attach(skel);
if (CHECK(err, "bpf_iter_test_kern1__attach",
"skeleton attach failed\n")) {
goto out;
}
link = skel->links.dump_task;
iter_fd = bpf_iter_create(bpf_link__fd(link));
if (CHECK(iter_fd < 0, "create_iter", "create_iter failed\n"))
goto out;
do_read_with_fd(iter_fd, "abcd", read_one_char);
close(iter_fd);
out:
bpf_iter_test_kern1__destroy(skel);
}
static int do_read(const char *path, const char *expected)
{
int err, iter_fd;
iter_fd = open(path, O_RDONLY);
if (CHECK(iter_fd < 0, "open", "open %s failed: %s\n",
path, strerror(errno)))
return -1;
err = do_read_with_fd(iter_fd, expected, false);
close(iter_fd);
return err;
}
static void test_file_iter(void)
{
const char *path = "/sys/fs/bpf/bpf_iter_test1";
struct bpf_iter_test_kern1 *skel1;
struct bpf_iter_test_kern2 *skel2;
struct bpf_link *link;
int err;
skel1 = bpf_iter_test_kern1__open_and_load();
if (CHECK(!skel1, "bpf_iter_test_kern1__open_and_load",
"skeleton open_and_load failed\n"))
return;
link = bpf_program__attach_iter(skel1->progs.dump_task, NULL);
if (CHECK(IS_ERR(link), "attach_iter", "attach_iter failed\n"))
goto out;
/* unlink this path if it exists. */
unlink(path);
err = bpf_link__pin(link, path);
if (CHECK(err, "pin_iter", "pin_iter to %s failed: %d\n", path, err))
goto free_link;
err = do_read(path, "abcd");
if (err)
goto unlink_path;
/* file based iterator seems working fine. Let us a link update
* of the underlying link and `cat` the iterator again, its content
* should change.
*/
skel2 = bpf_iter_test_kern2__open_and_load();
if (CHECK(!skel2, "bpf_iter_test_kern2__open_and_load",
"skeleton open_and_load failed\n"))
goto unlink_path;
err = bpf_link__update_program(link, skel2->progs.dump_task);
if (CHECK(err, "update_prog", "update_prog failed\n"))
goto destroy_skel2;
do_read(path, "ABCD");
destroy_skel2:
bpf_iter_test_kern2__destroy(skel2);
unlink_path:
unlink(path);
free_link:
bpf_link__destroy(link);
out:
bpf_iter_test_kern1__destroy(skel1);
}
static void test_overflow(bool test_e2big_overflow, bool ret1)
{
__u32 map_info_len, total_read_len, expected_read_len;
int err, iter_fd, map1_fd, map2_fd, len;
struct bpf_map_info map_info = {};
struct bpf_iter_test_kern4 *skel;
struct bpf_link *link;
__u32 page_size;
char *buf;
skel = bpf_iter_test_kern4__open();
if (CHECK(!skel, "bpf_iter_test_kern4__open",
"skeleton open failed\n"))
return;
/* create two maps: bpf program will only do bpf_seq_write
* for these two maps. The goal is one map output almost
* fills seq_file buffer and then the other will trigger
* overflow and needs restart.
*/
map1_fd = bpf_create_map(BPF_MAP_TYPE_ARRAY, 4, 8, 1, 0);
if (CHECK(map1_fd < 0, "bpf_create_map",
"map_creation failed: %s\n", strerror(errno)))
goto out;
map2_fd = bpf_create_map(BPF_MAP_TYPE_ARRAY, 4, 8, 1, 0);
if (CHECK(map2_fd < 0, "bpf_create_map",
"map_creation failed: %s\n", strerror(errno)))
goto free_map1;
/* bpf_seq_printf kernel buffer is one page, so one map
* bpf_seq_write will mostly fill it, and the other map
* will partially fill and then trigger overflow and need
* bpf_seq_read restart.
*/
page_size = sysconf(_SC_PAGE_SIZE);
if (test_e2big_overflow) {
skel->rodata->print_len = (page_size + 8) / 8;
expected_read_len = 2 * (page_size + 8);
} else if (!ret1) {
skel->rodata->print_len = (page_size - 8) / 8;
expected_read_len = 2 * (page_size - 8);
} else {
skel->rodata->print_len = 1;
expected_read_len = 2 * 8;
}
skel->rodata->ret1 = ret1;
if (CHECK(bpf_iter_test_kern4__load(skel),
"bpf_iter_test_kern4__load", "skeleton load failed\n"))
goto free_map2;
/* setup filtering map_id in bpf program */
map_info_len = sizeof(map_info);
err = bpf_obj_get_info_by_fd(map1_fd, &map_info, &map_info_len);
if (CHECK(err, "get_map_info", "get map info failed: %s\n",
strerror(errno)))
goto free_map2;
skel->bss->map1_id = map_info.id;
err = bpf_obj_get_info_by_fd(map2_fd, &map_info, &map_info_len);
if (CHECK(err, "get_map_info", "get map info failed: %s\n",
strerror(errno)))
goto free_map2;
skel->bss->map2_id = map_info.id;
link = bpf_program__attach_iter(skel->progs.dump_bpf_map, NULL);
if (CHECK(IS_ERR(link), "attach_iter", "attach_iter failed\n"))
goto free_map2;
iter_fd = bpf_iter_create(bpf_link__fd(link));
if (CHECK(iter_fd < 0, "create_iter", "create_iter failed\n"))
goto free_link;
buf = malloc(expected_read_len);
if (!buf)
goto close_iter;
/* do read */
total_read_len = 0;
if (test_e2big_overflow) {
while ((len = read(iter_fd, buf, expected_read_len)) > 0)
total_read_len += len;
CHECK(len != -1 || errno != E2BIG, "read",
"expected ret -1, errno E2BIG, but get ret %d, error %s\n",
len, strerror(errno));
goto free_buf;
} else if (!ret1) {
while ((len = read(iter_fd, buf, expected_read_len)) > 0)
total_read_len += len;
if (CHECK(len < 0, "read", "read failed: %s\n",
strerror(errno)))
goto free_buf;
} else {
do {
len = read(iter_fd, buf, expected_read_len);
if (len > 0)
total_read_len += len;
} while (len > 0 || len == -EAGAIN);
if (CHECK(len < 0, "read", "read failed: %s\n",
strerror(errno)))
goto free_buf;
}
if (CHECK(total_read_len != expected_read_len, "read",
"total len %u, expected len %u\n", total_read_len,
expected_read_len))
goto free_buf;
if (CHECK(skel->bss->map1_accessed != 1, "map1_accessed",
"expected 1 actual %d\n", skel->bss->map1_accessed))
goto free_buf;
if (CHECK(skel->bss->map2_accessed != 2, "map2_accessed",
"expected 2 actual %d\n", skel->bss->map2_accessed))
goto free_buf;
CHECK(skel->bss->map2_seqnum1 != skel->bss->map2_seqnum2,
"map2_seqnum", "two different seqnum %lld %lld\n",
skel->bss->map2_seqnum1, skel->bss->map2_seqnum2);
free_buf:
free(buf);
close_iter:
close(iter_fd);
free_link:
bpf_link__destroy(link);
free_map2:
close(map2_fd);
free_map1:
close(map1_fd);
out:
bpf_iter_test_kern4__destroy(skel);
}
void test_bpf_iter(void)
{
if (test__start_subtest("btf_id_or_null"))
test_btf_id_or_null();
if (test__start_subtest("ipv6_route"))
test_ipv6_route();
if (test__start_subtest("netlink"))
test_netlink();
if (test__start_subtest("bpf_map"))
test_bpf_map();
if (test__start_subtest("task"))
test_task();
if (test__start_subtest("task_file"))
test_task_file();
if (test__start_subtest("anon"))
test_anon_iter(false);
if (test__start_subtest("anon-read-one-char"))
test_anon_iter(true);
if (test__start_subtest("file"))
test_file_iter();
if (test__start_subtest("overflow"))
test_overflow(false, false);
if (test__start_subtest("overflow-e2big"))
test_overflow(true, false);
if (test__start_subtest("prog-ret-1"))
test_overflow(false, true);
}
// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2020 Facebook */
#define START_CHAR 'a'
#include "bpf_iter_test_kern_common.h"
// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2020 Facebook */
#define START_CHAR 'A'
#include "bpf_iter_test_kern_common.h"
// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2020 Facebook */
#include "vmlinux.h"
#include <bpf/bpf_helpers.h>
char _license[] SEC("license") = "GPL";
SEC("iter/task")
int dump_task(struct bpf_iter__task *ctx)
{
struct seq_file *seq = ctx->meta->seq;
struct task_struct *task = ctx->task;
int tgid;
tgid = task->tgid;
bpf_seq_write(seq, &tgid, sizeof(tgid));
return 0;
}
// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2020 Facebook */
#include "vmlinux.h"
#include <bpf/bpf_helpers.h>
char _license[] SEC("license") = "GPL";
__u32 map1_id = 0, map2_id = 0;
__u32 map1_accessed = 0, map2_accessed = 0;
__u64 map1_seqnum = 0, map2_seqnum1 = 0, map2_seqnum2 = 0;
static volatile const __u32 print_len;
static volatile const __u32 ret1;
SEC("iter/bpf_map")
int dump_bpf_map(struct bpf_iter__bpf_map *ctx)
{
struct seq_file *seq = ctx->meta->seq;
struct bpf_map *map = ctx->map;
__u64 seq_num;
int i, ret = 0;
if (map == (void *)0)
return 0;
/* only dump map1_id and map2_id */
if (map->id != map1_id && map->id != map2_id)
return 0;
seq_num = ctx->meta->seq_num;
if (map->id == map1_id) {
map1_seqnum = seq_num;
map1_accessed++;
}
if (map->id == map2_id) {
if (map2_accessed == 0) {
map2_seqnum1 = seq_num;
if (ret1)
ret = 1;
} else {
map2_seqnum2 = seq_num;
}
map2_accessed++;
}
/* fill seq_file buffer */
for (i = 0; i < print_len; i++)
bpf_seq_write(seq, &seq_num, sizeof(seq_num));
return ret;
}
/* SPDX-License-Identifier: GPL-2.0 */
/* Copyright (c) 2020 Facebook */
#include "vmlinux.h"
#include <bpf/bpf_helpers.h>
char _license[] SEC("license") = "GPL";
int count = 0;
SEC("iter/task")
int dump_task(struct bpf_iter__task *ctx)
{
struct seq_file *seq = ctx->meta->seq;
char c;
if (count < 4) {
c = START_CHAR + count;
bpf_seq_write(seq, &c, sizeof(c));
count++;
}
return 0;
}
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