// SPDX-License-Identifier: GPL-2.0
#include <vmlinux.h>
#include <bpf/bpf_tracing.h>
#include <bpf/bpf_helpers.h>
#include "../test_kmods/bpf_testmod_kfunc.h"

struct map_value {
        struct prog_test_ref_kfunc __kptr *ptr;
};

struct {
        __uint(type, BPF_MAP_TYPE_ARRAY);
        __type(key, int);
        __type(value, struct map_value);
        __uint(max_entries, 16);
} array_map SEC(".maps");

static __noinline int cb1(void *map, void *key, void *value, void *ctx)
{
        void *p = *(void **)ctx;
        bpf_kfunc_call_test_release(p);
        /* Without the fix this would cause underflow */
        return 0;
}

SEC("?tc")
int underflow_prog(void *ctx)
{
        struct prog_test_ref_kfunc *p;
        unsigned long sl = 0;

        p = bpf_kfunc_call_test_acquire(&sl);
        if (!p)
                return 0;
        bpf_for_each_map_elem(&array_map, cb1, &p, 0);
        bpf_kfunc_call_test_release(p);
        return 0;
}

static __always_inline int cb2(void *map, void *key, void *value, void *ctx)
{
        unsigned long sl = 0;

        *(void **)ctx = bpf_kfunc_call_test_acquire(&sl);
        /* Without the fix this would leak memory */
        return 0;
}

SEC("?tc")
int leak_prog(void *ctx)
{
        struct prog_test_ref_kfunc *p;
        struct map_value *v;

        v = bpf_map_lookup_elem(&array_map, &(int){0});
        if (!v)
                return 0;

        p = NULL;
        bpf_for_each_map_elem(&array_map, cb2, &p, 0);
        p = bpf_kptr_xchg(&v->ptr, p);
        if (p)
                bpf_kfunc_call_test_release(p);
        return 0;
}

static __always_inline int cb(void *map, void *key, void *value, void *ctx)
{
        return 0;
}

static __always_inline int cb3(void *map, void *key, void *value, void *ctx)
{
        unsigned long sl = 0;
        void *p;

        bpf_kfunc_call_test_acquire(&sl);
        bpf_for_each_map_elem(&array_map, cb, &p, 0);
        /* It should only complain here, not in cb. This is why we need
         * callback_ref to be set to frameno.
         */
        return 0;
}

SEC("?tc")
int nested_cb(void *ctx)
{
        struct prog_test_ref_kfunc *p;
        unsigned long sl = 0;
        int sp = 0;

        p = bpf_kfunc_call_test_acquire(&sl);
        if (!p)
                return 0;
        bpf_for_each_map_elem(&array_map, cb3, &sp, 0);
        bpf_kfunc_call_test_release(p);
        return 0;
}

SEC("?tc")
int non_cb_transfer_ref(void *ctx)
{
        struct prog_test_ref_kfunc *p;
        unsigned long sl = 0;

        p = bpf_kfunc_call_test_acquire(&sl);
        if (!p)
                return 0;
        cb1(NULL, NULL, NULL, &p);
        bpf_kfunc_call_test_acquire(&sl);
        return 0;
}

char _license[] SEC("license") = "GPL";