// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2023 Meta Platforms, Inc. and affiliates. */
#include <vmlinux.h>
#include <bpf/bpf_tracing.h>
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_core_read.h>
#include "../bpf_experimental.h"
#include "../bpf_testmod/bpf_testmod_kfunc.h"
struct plain_local;
struct node_data {
long key;
long data;
struct plain_local __kptr * stashed_in_local_kptr;
struct bpf_rb_node node;
};
struct refcounted_node {
long data;
struct bpf_rb_node rb_node;
struct bpf_refcount refcount;
};
struct stash {
struct bpf_spin_lock l;
struct refcounted_node __kptr *stashed;
};
struct {
__uint(type, BPF_MAP_TYPE_ARRAY);
__type(key, int);
__type(value, struct stash);
__uint(max_entries, 10);
} refcounted_node_stash SEC(".maps");
struct plain_local {
long key;
long data;
};
struct local_with_root {
long key;
struct bpf_spin_lock l;
struct bpf_rb_root r __contains(node_data, node);
};
struct map_value {
struct prog_test_ref_kfunc *not_kptr;
struct prog_test_ref_kfunc __kptr *val;
struct node_data __kptr *node;
struct plain_local __kptr *plain;
struct local_with_root __kptr *local_root;
};
/* This is necessary so that LLVM generates BTF for node_data struct
* If it's not included, a fwd reference for node_data will be generated but
* no struct. Example BTF of "node" field in map_value when not included:
*
* [10] PTR '(anon)' type_id=35
* [34] FWD 'node_data' fwd_kind=struct
* [35] TYPE_TAG 'kptr_ref' type_id=34
*
* (with no node_data struct defined)
* Had to do the same w/ bpf_kfunc_call_test_release below
*/
struct node_data *just_here_because_btf_bug;
struct refcounted_node *just_here_because_btf_bug2;
struct {
__uint(type, BPF_MAP_TYPE_ARRAY);
__type(key, int);
__type(value, struct map_value);
__uint(max_entries, 2);
} some_nodes SEC(".maps");
static bool less(struct bpf_rb_node *a, const struct bpf_rb_node *b)
{
struct node_data *node_a;
struct node_data *node_b;
node_a = container_of(a, struct node_data, node);
node_b = container_of(b, struct node_data, node);
return node_a->key < node_b->key;
}
static int create_and_stash(int idx, int val)
{
struct plain_local *inner_local_kptr;
struct map_value *mapval;
struct node_data *res;
mapval = bpf_map_lookup_elem(&some_nodes, &idx);
if (!mapval)
return 1;
inner_local_kptr = bpf_obj_new(typeof(*inner_local_kptr));
if (!inner_local_kptr)
return 2;
res = bpf_obj_new(typeof(*res));
if (!res) {
bpf_obj_drop(inner_local_kptr);
return 3;
}
res->key = val;
inner_local_kptr = bpf_kptr_xchg(&res->stashed_in_local_kptr, inner_local_kptr);
if (inner_local_kptr) {
/* Should never happen, we just obj_new'd res */
bpf_obj_drop(inner_local_kptr);
bpf_obj_drop(res);
return 4;
}
res = bpf_kptr_xchg(&mapval->node, res);
if (res)
bpf_obj_drop(res);
return 0;
}
SEC("tc")
long stash_rb_nodes(void *ctx)
{
return create_and_stash(0, 41) ?: create_and_stash(1, 42);
}
SEC("tc")
long stash_plain(void *ctx)
{
struct map_value *mapval;
struct plain_local *res;
int idx = 0;
mapval = bpf_map_lookup_elem(&some_nodes, &idx);
if (!mapval)
return 1;
res = bpf_obj_new(typeof(*res));
if (!res)
return 1;
res->key = 41;
res = bpf_kptr_xchg(&mapval->plain, res);
if (res)
bpf_obj_drop(res);
return 0;
}
SEC("tc")
long stash_local_with_root(void *ctx)
{
struct local_with_root *res;
struct map_value *mapval;
struct node_data *n;
int idx = 0;
mapval = bpf_map_lookup_elem(&some_nodes, &idx);
if (!mapval)
return 1;
res = bpf_obj_new(typeof(*res));
if (!res)
return 2;
res->key = 41;
n = bpf_obj_new(typeof(*n));
if (!n) {
bpf_obj_drop(res);
return 3;
}
bpf_spin_lock(&res->l);
bpf_rbtree_add(&res->r, &n->node, less);
bpf_spin_unlock(&res->l);
res = bpf_kptr_xchg(&mapval->local_root, res);
if (res) {
bpf_obj_drop(res);
return 4;
}
return 0;
}
SEC("tc")
long unstash_rb_node(void *ctx)
{
struct plain_local *inner_local_kptr = NULL;
struct map_value *mapval;
struct node_data *res;
long retval;
int key = 1;
mapval = bpf_map_lookup_elem(&some_nodes, &key);
if (!mapval)
return 1;
res = bpf_kptr_xchg(&mapval->node, NULL);
if (res) {
inner_local_kptr = bpf_kptr_xchg(&res->stashed_in_local_kptr, inner_local_kptr);
if (!inner_local_kptr) {
bpf_obj_drop(res);
return 1;
}
bpf_obj_drop(inner_local_kptr);
retval = res->key;
bpf_obj_drop(res);
return retval;
}
return 1;
}
SEC("tc")
long stash_test_ref_kfunc(void *ctx)
{
struct prog_test_ref_kfunc *res;
struct map_value *mapval;
int key = 0;
mapval = bpf_map_lookup_elem(&some_nodes, &key);
if (!mapval)
return 1;
res = bpf_kptr_xchg(&mapval->val, NULL);
if (res)
bpf_kfunc_call_test_release(res);
return 0;
}
SEC("tc")
long refcount_acquire_without_unstash(void *ctx)
{
struct refcounted_node *p;
struct stash *s;
int ret = 0;
s = bpf_map_lookup_elem(&refcounted_node_stash, &ret);
if (!s)
return 1;
if (!s->stashed)
/* refcount_acquire failure is expected when no refcounted_node
* has been stashed before this program executes
*/
return 2;
p = bpf_refcount_acquire(s->stashed);
if (!p)
return 3;
ret = s->stashed ? s->stashed->data : -1;
bpf_obj_drop(p);
return ret;
}
/* Helper for refcount_acquire_without_unstash test */
SEC("tc")
long stash_refcounted_node(void *ctx)
{
struct refcounted_node *p;
struct stash *s;
int key = 0;
s = bpf_map_lookup_elem(&refcounted_node_stash, &key);
if (!s)
return 1;
p = bpf_obj_new(typeof(*p));
if (!p)
return 2;
p->data = 42;
p = bpf_kptr_xchg(&s->stashed, p);
if (p) {
bpf_obj_drop(p);
return 3;
}
return 0;
}
char _license[] SEC("license") = "GPL";
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