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// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2025 Meta Platforms, Inc. and affiliates. */
#include <vmlinux.h>
#include <string.h>
#include <stdbool.h>
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
#include "bpf_misc.h"
char _license[] SEC("license") = "GPL";
const void *user_ptr = NULL;
struct elem {
char data[128];
struct bpf_task_work tw;
};
struct {
__uint(type, BPF_MAP_TYPE_HASH);
__uint(map_flags, BPF_F_NO_PREALLOC);
__uint(max_entries, 1);
__type(key, int);
__type(value, struct elem);
} hmap SEC(".maps");
struct {
__uint(type, BPF_MAP_TYPE_ARRAY);
__uint(max_entries, 1);
__type(key, int);
__type(value, struct elem);
} arrmap SEC(".maps");
static int process_work(struct bpf_map *map, void *key, void *value)
{
struct elem *work = value;
bpf_copy_from_user_str(work->data, sizeof(work->data), (const void *)user_ptr, 0);
return 0;
}
int key = 0;
SEC("perf_event")
__failure __msg("doesn't match map pointer in R3")
int mismatch_map(struct pt_regs *args)
{
struct elem *work;
struct task_struct *task;
task = bpf_get_current_task_btf();
work = bpf_map_lookup_elem(&arrmap, &key);
if (!work)
return 0;
bpf_task_work_schedule_resume(task, &work->tw, &hmap, process_work, NULL);
return 0;
}
SEC("perf_event")
__failure __msg("arg#1 doesn't point to a map value")
int no_map_task_work(struct pt_regs *args)
{
struct task_struct *task;
struct bpf_task_work tw;
task = bpf_get_current_task_btf();
bpf_task_work_schedule_resume(task, &tw, &hmap, process_work, NULL);
return 0;
}
SEC("perf_event")
__failure __msg("Possibly NULL pointer passed to trusted arg1")
int task_work_null(struct pt_regs *args)
{
struct task_struct *task;
task = bpf_get_current_task_btf();
bpf_task_work_schedule_resume(task, NULL, &hmap, process_work, NULL);
return 0;
}
SEC("perf_event")
__failure __msg("Possibly NULL pointer passed to trusted arg2")
int map_null(struct pt_regs *args)
{
struct elem *work;
struct task_struct *task;
task = bpf_get_current_task_btf();
work = bpf_map_lookup_elem(&arrmap, &key);
if (!work)
return 0;
bpf_task_work_schedule_resume(task, &work->tw, NULL, process_work, NULL);
return 0;
}
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