diff options
Diffstat (limited to 'tools/testing/selftests/bpf/progs/timer.c')
-rw-r--r-- | tools/testing/selftests/bpf/progs/timer.c | 424 |
1 files changed, 424 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/timer.c b/tools/testing/selftests/bpf/progs/timer.c new file mode 100644 index 000000000000..f615da97df26 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/timer.c @@ -0,0 +1,424 @@ +// 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"); + +struct { + __uint(type, BPF_MAP_TYPE_ARRAY); + __uint(max_entries, 1); + __type(key, int); + __type(value, struct elem); +} abs_timer SEC(".maps"), soft_timer_pinned SEC(".maps"), abs_timer_pinned SEC(".maps"), + race_array SEC(".maps"); + +__u64 bss_data; +__u64 abs_data; +__u64 err; +__u64 ok; +__u64 callback_check = 52; +__u64 callback2_check = 52; +__u64 pinned_callback_check; +__s32 pinned_cpu; + +#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_PROG2(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); + + 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_PROG2(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(); +} + +/* callback for absolute timer */ +static int timer_cb3(void *map, int *key, struct bpf_timer *timer) +{ + abs_data += 6; + + if (abs_data < 12) { + bpf_timer_start(timer, bpf_ktime_get_boot_ns() + 1000, + BPF_F_TIMER_ABS); + } else { + /* Re-arm timer ~35 seconds in future */ + bpf_timer_start(timer, bpf_ktime_get_boot_ns() + (1ull << 35), + BPF_F_TIMER_ABS); + } + + return 0; +} + +SEC("fentry/bpf_fentry_test3") +int BPF_PROG2(test3, int, a) +{ + int key = 0; + struct bpf_timer *timer; + + bpf_printk("test3"); + + timer = bpf_map_lookup_elem(&abs_timer, &key); + if (timer) { + if (bpf_timer_init(timer, &abs_timer, CLOCK_BOOTTIME) != 0) + err |= 2048; + bpf_timer_set_callback(timer, timer_cb3); + bpf_timer_start(timer, bpf_ktime_get_boot_ns() + 1000, + BPF_F_TIMER_ABS); + } + + return 0; +} + +/* callback for pinned timer */ +static int timer_cb_pinned(void *map, int *key, struct bpf_timer *timer) +{ + __s32 cpu = bpf_get_smp_processor_id(); + + if (cpu != pinned_cpu) + err |= 16384; + + pinned_callback_check++; + return 0; +} + +static void test_pinned_timer(bool soft) +{ + int key = 0; + void *map; + struct bpf_timer *timer; + __u64 flags = BPF_F_TIMER_CPU_PIN; + __u64 start_time; + + if (soft) { + map = &soft_timer_pinned; + start_time = 0; + } else { + map = &abs_timer_pinned; + start_time = bpf_ktime_get_boot_ns(); + flags |= BPF_F_TIMER_ABS; + } + + timer = bpf_map_lookup_elem(map, &key); + if (timer) { + if (bpf_timer_init(timer, map, CLOCK_BOOTTIME) != 0) + err |= 4096; + bpf_timer_set_callback(timer, timer_cb_pinned); + pinned_cpu = bpf_get_smp_processor_id(); + bpf_timer_start(timer, start_time + 1000, flags); + } else { + err |= 8192; + } +} + +SEC("fentry/bpf_fentry_test4") +int BPF_PROG2(test4, int, a) +{ + bpf_printk("test4"); + test_pinned_timer(true); + + return 0; +} + +SEC("fentry/bpf_fentry_test5") +int BPF_PROG2(test5, int, a) +{ + bpf_printk("test5"); + test_pinned_timer(false); + + return 0; +} + +static int race_timer_callback(void *race_array, int *race_key, struct bpf_timer *timer) +{ + bpf_timer_start(timer, 1000000, 0); + return 0; +} + +SEC("syscall") +int race(void *ctx) +{ + struct bpf_timer *timer; + int err, race_key = 0; + struct elem init; + + __builtin_memset(&init, 0, sizeof(struct elem)); + bpf_map_update_elem(&race_array, &race_key, &init, BPF_ANY); + + timer = bpf_map_lookup_elem(&race_array, &race_key); + if (!timer) + return 1; + + err = bpf_timer_init(timer, &race_array, CLOCK_MONOTONIC); + if (err && err != -EBUSY) + return 1; + + bpf_timer_set_callback(timer, race_timer_callback); + bpf_timer_start(timer, 0, 0); + bpf_timer_cancel(timer); + + return 0; +} |