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// 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_misc.h"
#include "cpumask_common.h"
char _license[] SEC("license") = "GPL";
/* Prototype for all of the program trace events below:
*
* TRACE_EVENT(task_newtask,
* TP_PROTO(struct task_struct *p, u64 clone_flags)
*/
SEC("tp_btf/task_newtask")
__failure __msg("Unreleased reference")
int BPF_PROG(test_alloc_no_release, struct task_struct *task, u64 clone_flags)
{
struct bpf_cpumask *cpumask;
cpumask = create_cpumask();
__sink(cpumask);
/* cpumask is never released. */
return 0;
}
SEC("tp_btf/task_newtask")
__failure __msg("NULL pointer passed to trusted arg0")
int BPF_PROG(test_alloc_double_release, struct task_struct *task, u64 clone_flags)
{
struct bpf_cpumask *cpumask;
cpumask = create_cpumask();
/* cpumask is released twice. */
bpf_cpumask_release(cpumask);
bpf_cpumask_release(cpumask);
return 0;
}
SEC("tp_btf/task_newtask")
__failure __msg("must be referenced")
int BPF_PROG(test_acquire_wrong_cpumask, struct task_struct *task, u64 clone_flags)
{
struct bpf_cpumask *cpumask;
/* Can't acquire a non-struct bpf_cpumask. */
cpumask = bpf_cpumask_acquire((struct bpf_cpumask *)task->cpus_ptr);
__sink(cpumask);
return 0;
}
SEC("tp_btf/task_newtask")
__failure __msg("bpf_cpumask_set_cpu args#1 expected pointer to STRUCT bpf_cpumask")
int BPF_PROG(test_mutate_cpumask, struct task_struct *task, u64 clone_flags)
{
/* Can't set the CPU of a non-struct bpf_cpumask. */
bpf_cpumask_set_cpu(0, (struct bpf_cpumask *)task->cpus_ptr);
return 0;
}
SEC("tp_btf/task_newtask")
__failure __msg("Unreleased reference")
int BPF_PROG(test_insert_remove_no_release, struct task_struct *task, u64 clone_flags)
{
struct bpf_cpumask *cpumask;
struct __cpumask_map_value *v;
cpumask = create_cpumask();
if (!cpumask)
return 0;
if (cpumask_map_insert(cpumask))
return 0;
v = cpumask_map_value_lookup();
if (!v)
return 0;
cpumask = bpf_kptr_xchg(&v->cpumask, NULL);
/* cpumask is never released. */
return 0;
}
SEC("tp_btf/task_newtask")
__failure __msg("NULL pointer passed to trusted arg0")
int BPF_PROG(test_cpumask_null, struct task_struct *task, u64 clone_flags)
{
/* NULL passed to KF_TRUSTED_ARGS kfunc. */
bpf_cpumask_empty(NULL);
return 0;
}
SEC("tp_btf/task_newtask")
__failure __msg("R2 must be a rcu pointer")
int BPF_PROG(test_global_mask_out_of_rcu, struct task_struct *task, u64 clone_flags)
{
struct bpf_cpumask *local, *prev;
local = create_cpumask();
if (!local)
return 0;
prev = bpf_kptr_xchg(&global_mask, local);
if (prev) {
bpf_cpumask_release(prev);
err = 3;
return 0;
}
bpf_rcu_read_lock();
local = global_mask;
if (!local) {
err = 4;
bpf_rcu_read_unlock();
return 0;
}
bpf_rcu_read_unlock();
/* RCU region is exited before calling KF_RCU kfunc. */
bpf_cpumask_test_cpu(0, (const struct cpumask *)local);
return 0;
}
SEC("tp_btf/task_newtask")
__failure __msg("NULL pointer passed to trusted arg1")
int BPF_PROG(test_global_mask_no_null_check, struct task_struct *task, u64 clone_flags)
{
struct bpf_cpumask *local, *prev;
local = create_cpumask();
if (!local)
return 0;
prev = bpf_kptr_xchg(&global_mask, local);
if (prev) {
bpf_cpumask_release(prev);
err = 3;
return 0;
}
bpf_rcu_read_lock();
local = global_mask;
/* No NULL check is performed on global cpumask kptr. */
bpf_cpumask_test_cpu(0, (const struct cpumask *)local);
bpf_rcu_read_unlock();
return 0;
}
SEC("tp_btf/task_newtask")
__failure __msg("Possibly NULL pointer passed to helper arg2")
int BPF_PROG(test_global_mask_rcu_no_null_check, struct task_struct *task, u64 clone_flags)
{
struct bpf_cpumask *prev, *curr;
curr = bpf_cpumask_create();
if (!curr)
return 0;
prev = bpf_kptr_xchg(&global_mask, curr);
if (prev)
bpf_cpumask_release(prev);
bpf_rcu_read_lock();
curr = global_mask;
/* PTR_TO_BTF_ID | PTR_MAYBE_NULL | MEM_RCU passed to bpf_kptr_xchg() */
prev = bpf_kptr_xchg(&global_mask, curr);
bpf_rcu_read_unlock();
if (prev)
bpf_cpumask_release(prev);
return 0;
}
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