linux/tools/testing/selftests/bpf/progs/async_stack_depth.c
Kumar Kartikeya Dwivedi 906bd22a44 selftests/bpf: Add selftest for check_stack_max_depth bug
Use the bpf_timer_set_callback helper to mark timer_cb as an async
callback, and put a direct call to timer_cb in the main subprog.

As the check_stack_max_depth happens after the do_check pass, the order
does not matter. Without the previous fix, the test passes successfully.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20230705144730.235802-3-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-07-05 19:14:54 -07:00

41 lines
805 B
C

// SPDX-License-Identifier: GPL-2.0
#include <vmlinux.h>
#include <bpf/bpf_helpers.h>
#include "bpf_misc.h"
struct hmap_elem {
struct bpf_timer timer;
};
struct {
__uint(type, BPF_MAP_TYPE_HASH);
__uint(max_entries, 64);
__type(key, int);
__type(value, struct hmap_elem);
} hmap SEC(".maps");
__attribute__((noinline))
static int timer_cb(void *map, int *key, struct bpf_timer *timer)
{
volatile char buf[256] = {};
return buf[69];
}
SEC("tc")
__failure __msg("combined stack size of 2 calls")
int prog(struct __sk_buff *ctx)
{
struct hmap_elem *elem;
volatile char buf[256] = {};
elem = bpf_map_lookup_elem(&hmap, &(int){0});
if (!elem)
return 0;
timer_cb(NULL, NULL, NULL);
return bpf_timer_set_callback(&elem->timer, timer_cb) + buf[0];
}
char _license[] SEC("license") = "GPL";