1*37c8d480SDaniel Borkmann // SPDX-License-Identifier: GPL-2.0
2*37c8d480SDaniel Borkmann
3*37c8d480SDaniel Borkmann #include "vmlinux.h"
4*37c8d480SDaniel Borkmann #include <bpf/bpf_helpers.h>
5*37c8d480SDaniel Borkmann #include <bpf/bpf_tracing.h>
6*37c8d480SDaniel Borkmann
7*37c8d480SDaniel Borkmann extern const int bpf_prog_active __ksym;
8*37c8d480SDaniel Borkmann
9*37c8d480SDaniel Borkmann struct {
10*37c8d480SDaniel Borkmann __uint(type, BPF_MAP_TYPE_RINGBUF);
11*37c8d480SDaniel Borkmann __uint(max_entries, 1 << 12);
12*37c8d480SDaniel Borkmann } ringbuf SEC(".maps");
13*37c8d480SDaniel Borkmann
14*37c8d480SDaniel Borkmann 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*37c8d480SDaniel Borkmann int BPF_PROG(d_path_check_rdonly_mem, struct path *path, struct kstat *stat,
16*37c8d480SDaniel Borkmann __u32 request_mask, unsigned int query_flags)
17*37c8d480SDaniel Borkmann {
18*37c8d480SDaniel Borkmann void *active;
19*37c8d480SDaniel Borkmann u32 cpu;
20*37c8d480SDaniel Borkmann
21*37c8d480SDaniel Borkmann cpu = bpf_get_smp_processor_id();
22*37c8d480SDaniel Borkmann active = (void *)bpf_per_cpu_ptr(&bpf_prog_active, cpu);
23*37c8d480SDaniel Borkmann if (active) {
24*37c8d480SDaniel Borkmann /* FAIL here! 'active' points to 'regular' memory. It
25*37c8d480SDaniel Borkmann * cannot be submitted to ring buffer.
26*37c8d480SDaniel Borkmann */
27*37c8d480SDaniel Borkmann bpf_ringbuf_submit(active, 0);
28*37c8d480SDaniel Borkmann }
29*37c8d480SDaniel Borkmann return 0;
30*37c8d480SDaniel Borkmann }
31*37c8d480SDaniel Borkmann
32*37c8d480SDaniel Borkmann char _license[] SEC("license") = "GPL";
33