| 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 | char _license[] SEC("license" ) = "GPL" ; |
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| 8 | |
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| 9 | #ifndef EBUSY |
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| 10 | #define EBUSY 16 |
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| 11 | #endif |
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| 12 | |
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| 13 | extern bool CONFIG_PREEMPT __kconfig __weak; |
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| 14 | int nr_get_errs = 0; |
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| 15 | int nr_del_errs = 0; |
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| 16 | |
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| 17 | struct { |
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| 18 | __uint(type, BPF_MAP_TYPE_TASK_STORAGE); |
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| 19 | __uint(map_flags, BPF_F_NO_PREALLOC); |
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| 20 | __type(key, int); |
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| 21 | __type(value, int); |
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| 22 | } task_storage SEC(".maps" ); |
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| 23 | |
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| 24 | SEC("lsm.s/socket_post_create" ) |
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| 25 | int BPF_PROG(socket_post_create, struct socket *sock, int family, int type, |
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| 26 | int protocol, int kern) |
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| 27 | { |
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| 28 | struct task_struct *task; |
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| 29 | int ret, zero = 0; |
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| 30 | int *value; |
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| 31 | |
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| 32 | if (!CONFIG_PREEMPT) |
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| 33 | return 0; |
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| 34 | |
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| 35 | task = bpf_get_current_task_btf(); |
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| 36 | value = bpf_task_storage_get(&task_storage, task, &zero, |
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| 37 | BPF_LOCAL_STORAGE_GET_F_CREATE); |
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| 38 | if (!value) |
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| 39 | __sync_fetch_and_add(&nr_get_errs, 1); |
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| 40 | |
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| 41 | ret = bpf_task_storage_delete(&task_storage, |
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| 42 | bpf_get_current_task_btf()); |
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| 43 | if (ret == -EBUSY) |
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| 44 | __sync_fetch_and_add(&nr_del_errs, 1); |
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| 45 | |
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| 46 | return 0; |
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| 47 | } |
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| 48 | |
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