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