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// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2025 Meta Platforms, Inc. and affiliates. */
#include <vmlinux.h>
#include <bpf/bpf_tracing.h>
#include <bpf/bpf_helpers.h>
#include "bpf_misc.h"
#include "bpf_experimental.h"
struct arr_elem {
struct bpf_res_spin_lock lock;
};
struct {
__uint(type, BPF_MAP_TYPE_ARRAY);
__uint(max_entries, 1);
__type(key, int);
__type(value, struct arr_elem);
} arrmap SEC(".maps");
#define ENOSPC 28
#define _STR "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
int size;
SEC("syscall")
__success __retval(0)
int stream_exhaust(void *ctx)
{
/* Use global variable for loop convergence. */
size = 0;
bpf_repeat(BPF_MAX_LOOPS) {
if (bpf_stream_printk(BPF_STDOUT, _STR) == -ENOSPC && size == 99954)
return 0;
size += sizeof(_STR) - 1;
}
return 1;
}
SEC("syscall")
__success __retval(0)
int stream_cond_break(void *ctx)
{
while (can_loop)
;
return 0;
}
SEC("syscall")
__success __retval(0)
int stream_deadlock(void *ctx)
{
struct bpf_res_spin_lock *lock, *nlock;
lock = bpf_map_lookup_elem(&arrmap, &(int){0});
if (!lock)
return 1;
nlock = bpf_map_lookup_elem(&arrmap, &(int){0});
if (!nlock)
return 1;
if (bpf_res_spin_lock(lock))
return 1;
if (bpf_res_spin_lock(nlock)) {
bpf_res_spin_unlock(lock);
return 0;
}
bpf_res_spin_unlock(nlock);
bpf_res_spin_unlock(lock);
return 1;
}
SEC("syscall")
__success __retval(0)
int stream_syscall(void *ctx)
{
bpf_stream_printk(BPF_STDOUT, "foo");
return 0;
}
char _license[] SEC("license") = "GPL";
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