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// SPDX-License-Identifier: GPL-2.0
#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_misc.h"
struct node_data {
long key;
long data;
struct bpf_rb_node node;
};
#define private(name) SEC(".data." #name) __hidden __attribute__((aligned(8)))
private(A) struct bpf_spin_lock glock;
private(A) struct bpf_rb_root groot __contains(node_data, node);
private(A) struct bpf_rb_root groot2 __contains(node_data, node);
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;
}
SEC("?tc")
__failure __msg("bpf_spin_lock at off=16 must be held for bpf_rb_root")
long rbtree_api_nolock_add(void *ctx)
{
struct node_data *n;
n = bpf_obj_new(typeof(*n));
if (!n)
return 1;
bpf_rbtree_add(&groot, &n->node, less);
return 0;
}
SEC("?tc")
__failure __msg("bpf_spin_lock at off=16 must be held for bpf_rb_root")
long rbtree_api_nolock_remove(void *ctx)
{
struct node_data *n;
n = bpf_obj_new(typeof(*n));
if (!n)
return 1;
bpf_spin_lock(&glock);
bpf_rbtree_add(&groot, &n->node, less);
bpf_spin_unlock(&glock);
bpf_rbtree_remove(&groot, &n->node);
return 0;
}
SEC("?tc")
__failure __msg("bpf_spin_lock at off=16 must be held for bpf_rb_root")
long rbtree_api_nolock_first(void *ctx)
{
bpf_rbtree_first(&groot);
return 0;
}
SEC("?tc")
__failure __msg("rbtree_remove node input must be non-owning ref")
long rbtree_api_remove_unadded_node(void *ctx)
{
struct node_data *n, *m;
struct bpf_rb_node *res;
n = bpf_obj_new(typeof(*n));
if (!n)
return 1;
m = bpf_obj_new(typeof(*m));
if (!m) {
bpf_obj_drop(n);
return 1;
}
bpf_spin_lock(&glock);
bpf_rbtree_add(&groot, &n->node, less);
/* This remove should pass verifier */
res = bpf_rbtree_remove(&groot, &n->node);
n = container_of(res, struct node_data, node);
/* This remove shouldn't, m isn't in an rbtree */
res = bpf_rbtree_remove(&groot, &m->node);
m = container_of(res, struct node_data, node);
bpf_spin_unlock(&glock);
if (n)
bpf_obj_drop(n);
if (m)
bpf_obj_drop(m);
return 0;
}
SEC("?tc")
__failure __regex("Unreleased reference id=3 alloc_insn=[0-9]+")
long rbtree_api_remove_no_drop(void *ctx)
{
struct bpf_rb_node *res;
struct node_data *n;
bpf_spin_lock(&glock);
res = bpf_rbtree_first(&groot);
if (!res)
goto unlock_err;
res = bpf_rbtree_remove(&groot, res);
if (res) {
n = container_of(res, struct node_data, node);
__sink(n);
}
bpf_spin_unlock(&glock);
/* if (res) { bpf_obj_drop(n); } is missing here */
return 0;
unlock_err:
bpf_spin_unlock(&glock);
return 1;
}
SEC("?tc")
__failure __msg("arg#1 expected pointer to allocated object")
long rbtree_api_add_to_multiple_trees(void *ctx)
{
struct node_data *n;
n = bpf_obj_new(typeof(*n));
if (!n)
return 1;
bpf_spin_lock(&glock);
bpf_rbtree_add(&groot, &n->node, less);
/* This add should fail since n already in groot's tree */
bpf_rbtree_add(&groot2, &n->node, less);
bpf_spin_unlock(&glock);
return 0;
}
SEC("?tc")
__failure __msg("dereference of modified ptr_or_null_ ptr R2 off=16 disallowed")
long rbtree_api_use_unchecked_remove_retval(void *ctx)
{
struct bpf_rb_node *res;
bpf_spin_lock(&glock);
res = bpf_rbtree_first(&groot);
if (!res)
goto err_out;
res = bpf_rbtree_remove(&groot, res);
bpf_spin_unlock(&glock);
bpf_spin_lock(&glock);
/* Must check res for NULL before using in rbtree_add below */
bpf_rbtree_add(&groot, res, less);
bpf_spin_unlock(&glock);
return 0;
err_out:
bpf_spin_unlock(&glock);
return 1;
}
SEC("?tc")
__failure __msg("rbtree_remove node input must be non-owning ref")
long rbtree_api_add_release_unlock_escape(void *ctx)
{
struct node_data *n;
n = bpf_obj_new(typeof(*n));
if (!n)
return 1;
bpf_spin_lock(&glock);
bpf_rbtree_add(&groot, &n->node, less);
bpf_spin_unlock(&glock);
bpf_spin_lock(&glock);
/* After add() in previous critical section, n should be
* release_on_unlock and released after previous spin_unlock,
* so should not be possible to use it here
*/
bpf_rbtree_remove(&groot, &n->node);
bpf_spin_unlock(&glock);
return 0;
}
SEC("?tc")
__failure __msg("rbtree_remove node input must be non-owning ref")
long rbtree_api_first_release_unlock_escape(void *ctx)
{
struct bpf_rb_node *res;
struct node_data *n;
bpf_spin_lock(&glock);
res = bpf_rbtree_first(&groot);
if (!res) {
bpf_spin_unlock(&glock);
return 1;
}
n = container_of(res, struct node_data, node);
bpf_spin_unlock(&glock);
bpf_spin_lock(&glock);
/* After first() in previous critical section, n should be
* release_on_unlock and released after previous spin_unlock,
* so should not be possible to use it here
*/
bpf_rbtree_remove(&groot, &n->node);
bpf_spin_unlock(&glock);
return 0;
}
static bool less__bad_fn_call_add(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);
bpf_rbtree_add(&groot, &node_a->node, less);
return node_a->key < node_b->key;
}
static bool less__bad_fn_call_remove(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);
bpf_rbtree_remove(&groot, &node_a->node);
return node_a->key < node_b->key;
}
static bool less__bad_fn_call_first_unlock_after(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);
bpf_rbtree_first(&groot);
bpf_spin_unlock(&glock);
return node_a->key < node_b->key;
}
static __always_inline
long add_with_cb(bool (cb)(struct bpf_rb_node *a, const struct bpf_rb_node *b))
{
struct node_data *n;
n = bpf_obj_new(typeof(*n));
if (!n)
return 1;
bpf_spin_lock(&glock);
bpf_rbtree_add(&groot, &n->node, cb);
bpf_spin_unlock(&glock);
return 0;
}
SEC("?tc")
__failure __msg("arg#1 expected pointer to allocated object")
long rbtree_api_add_bad_cb_bad_fn_call_add(void *ctx)
{
return add_with_cb(less__bad_fn_call_add);
}
SEC("?tc")
__failure __msg("rbtree_remove not allowed in rbtree cb")
long rbtree_api_add_bad_cb_bad_fn_call_remove(void *ctx)
{
return add_with_cb(less__bad_fn_call_remove);
}
SEC("?tc")
__failure __msg("can't spin_{lock,unlock} in rbtree cb")
long rbtree_api_add_bad_cb_bad_fn_call_first_unlock_after(void *ctx)
{
return add_with_cb(less__bad_fn_call_first_unlock_after);
}
char _license[] SEC("license") = "GPL";
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