selftests/bpf: Add bpf_timer test.
Add bpf_timer test that creates timers in preallocated and non-preallocated hash, in array and in lru maps. Let array timer expire once and then re-arm it for 35 seconds. Arm lru timer into the same callback. Then arm and re-arm hash timers 10 times each. At the last invocation of prealloc hash timer cancel the array timer. Force timer free via LRU eviction and direct bpf_map_delete_elem. 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/20210715005417.78572-11-alexei.starovoitov@gmail.com
This commit is contained in:
Alexei Starovoitov
Daniel Borkmann
parent
7ddc80a476
commit
3540f7c6b9
|
|
@ -0,0 +1,55 @@
|
|||
// SPDX-License-Identifier: GPL-2.0
|
||||
/* Copyright (c) 2021 Facebook */
|
||||
#include <test_progs.h>
|
||||
#include "timer.skel.h"
|
||||
|
||||
static int timer(struct timer *timer_skel)
|
||||
{
|
||||
int err, prog_fd;
|
||||
__u32 duration = 0, retval;
|
||||
|
||||
err = timer__attach(timer_skel);
|
||||
if (!ASSERT_OK(err, "timer_attach"))
|
||||
return err;
|
||||
|
||||
ASSERT_EQ(timer_skel->data->callback_check, 52, "callback_check1");
|
||||
ASSERT_EQ(timer_skel->data->callback2_check, 52, "callback2_check1");
|
||||
|
||||
prog_fd = bpf_program__fd(timer_skel->progs.test1);
|
||||
err = bpf_prog_test_run(prog_fd, 1, NULL, 0,
|
||||
NULL, NULL, &retval, &duration);
|
||||
ASSERT_OK(err, "test_run");
|
||||
ASSERT_EQ(retval, 0, "test_run");
|
||||
timer__detach(timer_skel);
|
||||
|
||||
usleep(50); /* 10 usecs should be enough, but give it extra */
|
||||
/* check that timer_cb1() was executed 10+10 times */
|
||||
ASSERT_EQ(timer_skel->data->callback_check, 42, "callback_check2");
|
||||
ASSERT_EQ(timer_skel->data->callback2_check, 42, "callback2_check2");
|
||||
|
||||
/* check that timer_cb2() was executed twice */
|
||||
ASSERT_EQ(timer_skel->bss->bss_data, 10, "bss_data");
|
||||
|
||||
/* check that there were no errors in timer execution */
|
||||
ASSERT_EQ(timer_skel->bss->err, 0, "err");
|
||||
|
||||
/* check that code paths completed */
|
||||
ASSERT_EQ(timer_skel->bss->ok, 1 | 2 | 4, "ok");
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
void test_timer(void)
|
||||
{
|
||||
struct timer *timer_skel = NULL;
|
||||
int err;
|
||||
|
||||
timer_skel = timer__open_and_load();
|
||||
if (!ASSERT_OK_PTR(timer_skel, "timer_skel_load"))
|
||||
goto cleanup;
|
||||
|
||||
err = timer(timer_skel);
|
||||
ASSERT_OK(err, "timer");
|
||||
cleanup:
|
||||
timer__destroy(timer_skel);
|
||||
}
|
||||
|
|
@ -0,0 +1,297 @@
|
|||
// 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 counter;
|
||||
struct bpf_timer timer;
|
||||
struct bpf_spin_lock lock; /* unused */
|
||||
};
|
||||
|
||||
struct {
|
||||
__uint(type, BPF_MAP_TYPE_HASH);
|
||||
__uint(max_entries, 1000);
|
||||
__type(key, int);
|
||||
__type(value, struct hmap_elem);
|
||||
} hmap SEC(".maps");
|
||||
|
||||
struct {
|
||||
__uint(type, BPF_MAP_TYPE_HASH);
|
||||
__uint(map_flags, BPF_F_NO_PREALLOC);
|
||||
__uint(max_entries, 1000);
|
||||
__type(key, int);
|
||||
__type(value, struct hmap_elem);
|
||||
} hmap_malloc SEC(".maps");
|
||||
|
||||
struct elem {
|
||||
struct bpf_timer t;
|
||||
};
|
||||
|
||||
struct {
|
||||
__uint(type, BPF_MAP_TYPE_ARRAY);
|
||||
__uint(max_entries, 2);
|
||||
__type(key, int);
|
||||
__type(value, struct elem);
|
||||
} array SEC(".maps");
|
||||
|
||||
struct {
|
||||
__uint(type, BPF_MAP_TYPE_LRU_HASH);
|
||||
__uint(max_entries, 4);
|
||||
__type(key, int);
|
||||
__type(value, struct elem);
|
||||
} lru SEC(".maps");
|
||||
|
||||
__u64 bss_data;
|
||||
__u64 err;
|
||||
__u64 ok;
|
||||
__u64 callback_check = 52;
|
||||
__u64 callback2_check = 52;
|
||||
|
||||
#define ARRAY 1
|
||||
#define HTAB 2
|
||||
#define HTAB_MALLOC 3
|
||||
#define LRU 4
|
||||
|
||||
/* callback for array and lru timers */
|
||||
static int timer_cb1(void *map, int *key, struct bpf_timer *timer)
|
||||
{
|
||||
/* increment bss variable twice.
|
||||
* Once via array timer callback and once via lru timer callback
|
||||
*/
|
||||
bss_data += 5;
|
||||
|
||||
/* *key == 0 - the callback was called for array timer.
|
||||
* *key == 4 - the callback was called from lru timer.
|
||||
*/
|
||||
if (*key == ARRAY) {
|
||||
struct bpf_timer *lru_timer;
|
||||
int lru_key = LRU;
|
||||
|
||||
/* rearm array timer to be called again in ~35 seconds */
|
||||
if (bpf_timer_start(timer, 1ull << 35, 0) != 0)
|
||||
err |= 1;
|
||||
|
||||
lru_timer = bpf_map_lookup_elem(&lru, &lru_key);
|
||||
if (!lru_timer)
|
||||
return 0;
|
||||
bpf_timer_set_callback(lru_timer, timer_cb1);
|
||||
if (bpf_timer_start(lru_timer, 0, 0) != 0)
|
||||
err |= 2;
|
||||
} else if (*key == LRU) {
|
||||
int lru_key, i;
|
||||
|
||||
for (i = LRU + 1;
|
||||
i <= 100 /* for current LRU eviction algorithm this number
|
||||
* should be larger than ~ lru->max_entries * 2
|
||||
*/;
|
||||
i++) {
|
||||
struct elem init = {};
|
||||
|
||||
/* lru_key cannot be used as loop induction variable
|
||||
* otherwise the loop will be unbounded.
|
||||
*/
|
||||
lru_key = i;
|
||||
|
||||
/* add more elements into lru map to push out current
|
||||
* element and force deletion of this timer
|
||||
*/
|
||||
bpf_map_update_elem(map, &lru_key, &init, 0);
|
||||
/* look it up to bump it into active list */
|
||||
bpf_map_lookup_elem(map, &lru_key);
|
||||
|
||||
/* keep adding until *key changes underneath,
|
||||
* which means that key/timer memory was reused
|
||||
*/
|
||||
if (*key != LRU)
|
||||
break;
|
||||
}
|
||||
|
||||
/* check that the timer was removed */
|
||||
if (bpf_timer_cancel(timer) != -EINVAL)
|
||||
err |= 4;
|
||||
ok |= 1;
|
||||
}
|
||||
return 0;
|
||||
}
|
||||
|
||||
SEC("fentry/bpf_fentry_test1")
|
||||
int BPF_PROG(test1, int a)
|
||||
{
|
||||
struct bpf_timer *arr_timer, *lru_timer;
|
||||
struct elem init = {};
|
||||
int lru_key = LRU;
|
||||
int array_key = ARRAY;
|
||||
|
||||
arr_timer = bpf_map_lookup_elem(&array, &array_key);
|
||||
if (!arr_timer)
|
||||
return 0;
|
||||
bpf_timer_init(arr_timer, &array, CLOCK_MONOTONIC);
|
||||
|
||||
bpf_map_update_elem(&lru, &lru_key, &init, 0);
|
||||
lru_timer = bpf_map_lookup_elem(&lru, &lru_key);
|
||||
if (!lru_timer)
|
||||
return 0;
|
||||
bpf_timer_init(lru_timer, &lru, CLOCK_MONOTONIC);
|
||||
|
||||
bpf_timer_set_callback(arr_timer, timer_cb1);
|
||||
bpf_timer_start(arr_timer, 0 /* call timer_cb1 asap */, 0);
|
||||
|
||||
/* init more timers to check that array destruction
|
||||
* doesn't leak timer memory.
|
||||
*/
|
||||
array_key = 0;
|
||||
arr_timer = bpf_map_lookup_elem(&array, &array_key);
|
||||
if (!arr_timer)
|
||||
return 0;
|
||||
bpf_timer_init(arr_timer, &array, CLOCK_MONOTONIC);
|
||||
return 0;
|
||||
}
|
||||
|
||||
/* callback for prealloc and non-prealloca hashtab timers */
|
||||
static int timer_cb2(void *map, int *key, struct hmap_elem *val)
|
||||
{
|
||||
if (*key == HTAB)
|
||||
callback_check--;
|
||||
else
|
||||
callback2_check--;
|
||||
if (val->counter > 0 && --val->counter) {
|
||||
/* re-arm the timer again to execute after 1 usec */
|
||||
bpf_timer_start(&val->timer, 1000, 0);
|
||||
} else if (*key == HTAB) {
|
||||
struct bpf_timer *arr_timer;
|
||||
int array_key = ARRAY;
|
||||
|
||||
/* cancel arr_timer otherwise bpf_fentry_test1 prog
|
||||
* will stay alive forever.
|
||||
*/
|
||||
arr_timer = bpf_map_lookup_elem(&array, &array_key);
|
||||
if (!arr_timer)
|
||||
return 0;
|
||||
if (bpf_timer_cancel(arr_timer) != 1)
|
||||
/* bpf_timer_cancel should return 1 to indicate
|
||||
* that arr_timer was active at this time
|
||||
*/
|
||||
err |= 8;
|
||||
|
||||
/* try to cancel ourself. It shouldn't deadlock. */
|
||||
if (bpf_timer_cancel(&val->timer) != -EDEADLK)
|
||||
err |= 16;
|
||||
|
||||
/* delete this key and this timer anyway.
|
||||
* It shouldn't deadlock either.
|
||||
*/
|
||||
bpf_map_delete_elem(map, key);
|
||||
|
||||
/* in preallocated hashmap both 'key' and 'val' could have been
|
||||
* reused to store another map element (like in LRU above),
|
||||
* but in controlled test environment the below test works.
|
||||
* It's not a use-after-free. The memory is owned by the map.
|
||||
*/
|
||||
if (bpf_timer_start(&val->timer, 1000, 0) != -EINVAL)
|
||||
err |= 32;
|
||||
ok |= 2;
|
||||
} else {
|
||||
if (*key != HTAB_MALLOC)
|
||||
err |= 64;
|
||||
|
||||
/* try to cancel ourself. It shouldn't deadlock. */
|
||||
if (bpf_timer_cancel(&val->timer) != -EDEADLK)
|
||||
err |= 128;
|
||||
|
||||
/* delete this key and this timer anyway.
|
||||
* It shouldn't deadlock either.
|
||||
*/
|
||||
bpf_map_delete_elem(map, key);
|
||||
|
||||
/* in non-preallocated hashmap both 'key' and 'val' are RCU
|
||||
* protected and still valid though this element was deleted
|
||||
* from the map. Arm this timer for ~35 seconds. When callback
|
||||
* finishes the call_rcu will invoke:
|
||||
* htab_elem_free_rcu
|
||||
* check_and_free_timer
|
||||
* bpf_timer_cancel_and_free
|
||||
* to cancel this 35 second sleep and delete the timer for real.
|
||||
*/
|
||||
if (bpf_timer_start(&val->timer, 1ull << 35, 0) != 0)
|
||||
err |= 256;
|
||||
ok |= 4;
|
||||
}
|
||||
return 0;
|
||||
}
|
||||
|
||||
int bpf_timer_test(void)
|
||||
{
|
||||
struct hmap_elem *val;
|
||||
int key = HTAB, key_malloc = HTAB_MALLOC;
|
||||
|
||||
val = bpf_map_lookup_elem(&hmap, &key);
|
||||
if (val) {
|
||||
if (bpf_timer_init(&val->timer, &hmap, CLOCK_BOOTTIME) != 0)
|
||||
err |= 512;
|
||||
bpf_timer_set_callback(&val->timer, timer_cb2);
|
||||
bpf_timer_start(&val->timer, 1000, 0);
|
||||
}
|
||||
val = bpf_map_lookup_elem(&hmap_malloc, &key_malloc);
|
||||
if (val) {
|
||||
if (bpf_timer_init(&val->timer, &hmap_malloc, CLOCK_BOOTTIME) != 0)
|
||||
err |= 1024;
|
||||
bpf_timer_set_callback(&val->timer, timer_cb2);
|
||||
bpf_timer_start(&val->timer, 1000, 0);
|
||||
}
|
||||
return 0;
|
||||
}
|
||||
|
||||
SEC("fentry/bpf_fentry_test2")
|
||||
int BPF_PROG(test2, int a, int b)
|
||||
{
|
||||
struct hmap_elem init = {}, *val;
|
||||
int key = HTAB, key_malloc = HTAB_MALLOC;
|
||||
|
||||
init.counter = 10; /* number of times to trigger timer_cb2 */
|
||||
bpf_map_update_elem(&hmap, &key, &init, 0);
|
||||
val = bpf_map_lookup_elem(&hmap, &key);
|
||||
if (val)
|
||||
bpf_timer_init(&val->timer, &hmap, CLOCK_BOOTTIME);
|
||||
/* update the same key to free the timer */
|
||||
bpf_map_update_elem(&hmap, &key, &init, 0);
|
||||
|
||||
bpf_map_update_elem(&hmap_malloc, &key_malloc, &init, 0);
|
||||
val = bpf_map_lookup_elem(&hmap_malloc, &key_malloc);
|
||||
if (val)
|
||||
bpf_timer_init(&val->timer, &hmap_malloc, CLOCK_BOOTTIME);
|
||||
/* update the same key to free the timer */
|
||||
bpf_map_update_elem(&hmap_malloc, &key_malloc, &init, 0);
|
||||
|
||||
/* init more timers to check that htab operations
|
||||
* don't leak timer memory.
|
||||
*/
|
||||
key = 0;
|
||||
bpf_map_update_elem(&hmap, &key, &init, 0);
|
||||
val = bpf_map_lookup_elem(&hmap, &key);
|
||||
if (val)
|
||||
bpf_timer_init(&val->timer, &hmap, CLOCK_BOOTTIME);
|
||||
bpf_map_delete_elem(&hmap, &key);
|
||||
bpf_map_update_elem(&hmap, &key, &init, 0);
|
||||
val = bpf_map_lookup_elem(&hmap, &key);
|
||||
if (val)
|
||||
bpf_timer_init(&val->timer, &hmap, CLOCK_BOOTTIME);
|
||||
|
||||
/* and with non-prealloc htab */
|
||||
key_malloc = 0;
|
||||
bpf_map_update_elem(&hmap_malloc, &key_malloc, &init, 0);
|
||||
val = bpf_map_lookup_elem(&hmap_malloc, &key_malloc);
|
||||
if (val)
|
||||
bpf_timer_init(&val->timer, &hmap_malloc, CLOCK_BOOTTIME);
|
||||
bpf_map_delete_elem(&hmap_malloc, &key_malloc);
|
||||
bpf_map_update_elem(&hmap_malloc, &key_malloc, &init, 0);
|
||||
val = bpf_map_lookup_elem(&hmap_malloc, &key_malloc);
|
||||
if (val)
|
||||
bpf_timer_init(&val->timer, &hmap_malloc, CLOCK_BOOTTIME);
|
||||
|
||||
return bpf_timer_test();
|
||||
}
|
||||
Loading…
Reference in New Issue