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// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2022 Google */
#include "vmlinux.h"
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
extern const int bpf_prog_active __ksym;
SEC("fentry/security_inode_getattr")
int BPF_PROG(d_path_check_rdonly_mem, struct path *path, struct kstat *stat,
__u32 request_mask, unsigned int query_flags)
{
void *active;
__u32 cpu;
cpu = bpf_get_smp_processor_id();
active = (void *)bpf_per_cpu_ptr(&bpf_prog_active, cpu);
if (active) {
/* FAIL here! 'active' points to readonly memory. bpf helpers
* that update its arguments can not write into it.
*/
bpf_d_path(path, active, sizeof(int));
}
return 0;
}
char _license[] SEC("license") = "GPL";
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