linux/tools/testing/selftests/bpf/progs/timer_mim.c
Alexei Starovoitov 61f71e746c selftests/bpf: Add a test with bpf_timer in inner map.
Check that map-in-map supports bpf timers.

Check that indirect "recursion" of timer callbacks works:
timer_cb1() { bpf_timer_set_callback(timer_cb2); }
timer_cb2() { bpf_timer_set_callback(timer_cb1); }

Check that
  bpf_map_release
    htab_free_prealloced_timers
      bpf_timer_cancel_and_free
        hrtimer_cancel
works while timer cb is running.
"while true; do ./test_progs -t timer_mim; done"
is a great stress test. It caught missing timer cancel in htab->extra_elems.

timer_mim_reject.c is a negative test that checks
that timer<->map mismatch is prevented.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20210715005417.78572-12-alexei.starovoitov@gmail.com
2021-07-15 22:31:11 +02:00

89 lines
2 KiB
C

// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2021 Facebook */
#include <linux/bpf.h>
#include <time.h>
#include <errno.h>
#include <bpf/bpf_helpers.h>
#include "bpf_tcp_helpers.h"
char _license[] SEC("license") = "GPL";
struct hmap_elem {
int pad; /* unused */
struct bpf_timer timer;
};
struct inner_map {
__uint(type, BPF_MAP_TYPE_HASH);
__uint(max_entries, 1024);
__type(key, int);
__type(value, struct hmap_elem);
} inner_htab SEC(".maps");
#define ARRAY_KEY 1
#define HASH_KEY 1234
struct outer_arr {
__uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS);
__uint(max_entries, 2);
__uint(key_size, sizeof(int));
__uint(value_size, sizeof(int));
__array(values, struct inner_map);
} outer_arr SEC(".maps") = {
.values = { [ARRAY_KEY] = &inner_htab },
};
__u64 err;
__u64 ok;
__u64 cnt;
static int timer_cb1(void *map, int *key, struct hmap_elem *val);
static int timer_cb2(void *map, int *key, struct hmap_elem *val)
{
cnt++;
bpf_timer_set_callback(&val->timer, timer_cb1);
if (bpf_timer_start(&val->timer, 1000, 0))
err |= 1;
ok |= 1;
return 0;
}
/* callback for inner hash map */
static int timer_cb1(void *map, int *key, struct hmap_elem *val)
{
cnt++;
bpf_timer_set_callback(&val->timer, timer_cb2);
if (bpf_timer_start(&val->timer, 1000, 0))
err |= 2;
/* Do a lookup to make sure 'map' and 'key' pointers are correct */
bpf_map_lookup_elem(map, key);
ok |= 2;
return 0;
}
SEC("fentry/bpf_fentry_test1")
int BPF_PROG(test1, int a)
{
struct hmap_elem init = {};
struct bpf_map *inner_map;
struct hmap_elem *val;
int array_key = ARRAY_KEY;
int hash_key = HASH_KEY;
inner_map = bpf_map_lookup_elem(&outer_arr, &array_key);
if (!inner_map)
return 0;
bpf_map_update_elem(inner_map, &hash_key, &init, 0);
val = bpf_map_lookup_elem(inner_map, &hash_key);
if (!val)
return 0;
bpf_timer_init(&val->timer, inner_map, CLOCK_MONOTONIC);
if (bpf_timer_set_callback(&val->timer, timer_cb1))
err |= 4;
if (bpf_timer_start(&val->timer, 0, 0))
err |= 8;
return 0;
}