1 // SPDX-License-Identifier: GPL-2.0
2
3 #include "vmlinux.h"
4 #include <bpf/bpf_helpers.h>
5 #include <bpf/bpf_tracing.h>
6
7 extern const int bpf_prog_active __ksym;
8
9 struct {
10 __uint(type, BPF_MAP_TYPE_RINGBUF);
11 __uint(max_entries, 1 << 12);
12 } ringbuf SEC(".maps");
13
14 SEC("fentry/security_inode_getattr")
BPF_PROG(d_path_check_rdonly_mem,struct path * path,struct kstat * stat,__u32 request_mask,unsigned int query_flags)15 int BPF_PROG(d_path_check_rdonly_mem, struct path *path, struct kstat *stat,
16 __u32 request_mask, unsigned int query_flags)
17 {
18 void *active;
19 u32 cpu;
20
21 cpu = bpf_get_smp_processor_id();
22 active = (void *)bpf_per_cpu_ptr(&bpf_prog_active, cpu);
23 if (active) {
24 /* FAIL here! 'active' points to 'regular' memory. It
25 * cannot be submitted to ring buffer.
26 */
27 bpf_ringbuf_submit(active, 0);
28 }
29 return 0;
30 }
31
32 char _license[] SEC("license") = "GPL";
33