struct_ops_refcounted_fail__global_subprog.c

 1#include <vmlinux.h>
 2#include <bpf/bpf_tracing.h>
 3#include "../test_kmods/bpf_testmod.h"
 4#include "bpf_misc.h"
 5
 6char _license[] SEC("license") = "GPL";
 7
 8extern void bpf_task_release(struct task_struct *p) __ksym;
 9
10__noinline int subprog_release(__u64 *ctx __arg_ctx)
11{
12	struct task_struct *task = (struct task_struct *)ctx[1];
13	int dummy = (int)ctx[0];
14
15	bpf_task_release(task);
16
17	return dummy + 1;
18}
19
20/* Test that the verifier rejects a program that contains a global
21 * subprogram with referenced kptr arguments
22 */
23SEC("struct_ops/test_refcounted")
24__failure __log_level(2)
25__msg("Validating subprog_release() func#1...")
26__msg("invalid bpf_context access off=8. Reference may already be released")
27int refcounted_fail__global_subprog(unsigned long long *ctx)
28{
29	struct task_struct *task = (struct task_struct *)ctx[1];
30
31	bpf_task_release(task);
32
33	return subprog_release(ctx);
34}
35
36SEC(".struct_ops.link")
37struct bpf_testmod_ops testmod_ref_acquire = {
38	.test_refcounted = (void *)refcounted_fail__global_subprog,
39};