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1// SPDX-License-Identifier: GPL-2.02#include <vmlinux.h>3#include <bpf/bpf_tracing.h>4#include <bpf/bpf_helpers.h>5#include <bpf/bpf_core_read.h>6#include "bpf_experimental.h"7#include "bpf_misc.h"8 9struct node_acquire {10 long key;11 long data;12 struct bpf_rb_node node;13 struct bpf_refcount refcount;14};15 16extern void bpf_rcu_read_lock(void) __ksym;17extern void bpf_rcu_read_unlock(void) __ksym;18 19#define private(name) SEC(".data." #name) __hidden __attribute__((aligned(8)))20private(A) struct bpf_spin_lock glock;21private(A) struct bpf_rb_root groot __contains(node_acquire, node);22 23static bool less(struct bpf_rb_node *a, const struct bpf_rb_node *b)24{25 struct node_acquire *node_a;26 struct node_acquire *node_b;27 28 node_a = container_of(a, struct node_acquire, node);29 node_b = container_of(b, struct node_acquire, node);30 31 return node_a->key < node_b->key;32}33 34SEC("?tc")35__failure __msg("Unreleased reference id=4 alloc_insn={{[0-9]+}}")36long rbtree_refcounted_node_ref_escapes(void *ctx)37{38 struct node_acquire *n, *m;39 40 n = bpf_obj_new(typeof(*n));41 if (!n)42 return 1;43 44 bpf_spin_lock(&glock);45 bpf_rbtree_add(&groot, &n->node, less);46 /* m becomes an owning ref but is never drop'd or added to a tree */47 m = bpf_refcount_acquire(n);48 bpf_spin_unlock(&glock);49 if (!m)50 return 2;51 52 m->key = 2;53 return 0;54}55 56SEC("?tc")57__failure __msg("Possibly NULL pointer passed to trusted arg0")58long refcount_acquire_maybe_null(void *ctx)59{60 struct node_acquire *n, *m;61 62 n = bpf_obj_new(typeof(*n));63 /* Intentionally not testing !n64 * it's MAYBE_NULL for refcount_acquire65 */66 m = bpf_refcount_acquire(n);67 if (m)68 bpf_obj_drop(m);69 if (n)70 bpf_obj_drop(n);71 72 return 0;73}74 75SEC("?tc")76__failure __msg("Unreleased reference id=3 alloc_insn={{[0-9]+}}")77long rbtree_refcounted_node_ref_escapes_owning_input(void *ctx)78{79 struct node_acquire *n, *m;80 81 n = bpf_obj_new(typeof(*n));82 if (!n)83 return 1;84 85 /* m becomes an owning ref but is never drop'd or added to a tree */86 m = bpf_refcount_acquire(n);87 m->key = 2;88 89 bpf_spin_lock(&glock);90 bpf_rbtree_add(&groot, &n->node, less);91 bpf_spin_unlock(&glock);92 93 return 0;94}95 96SEC("?fentry.s/bpf_testmod_test_read")97__failure __msg("function calls are not allowed while holding a lock")98int BPF_PROG(rbtree_fail_sleepable_lock_across_rcu,99 struct file *file, struct kobject *kobj,100 struct bin_attribute *bin_attr, char *buf, loff_t off, size_t len)101{102 struct node_acquire *n;103 104 n = bpf_obj_new(typeof(*n));105 if (!n)106 return 0;107 108 /* spin_{lock,unlock} are in different RCU CS */109 bpf_rcu_read_lock();110 bpf_spin_lock(&glock);111 bpf_rbtree_add(&groot, &n->node, less);112 bpf_rcu_read_unlock();113 114 bpf_rcu_read_lock();115 bpf_spin_unlock(&glock);116 bpf_rcu_read_unlock();117 118 return 0;119}120 121char _license[] SEC("license") = "GPL";122