| 1 | // SPDX-License-Identifier: GPL-2.0 |
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| 2 | // Copyright (c) 2019 Facebook |
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| 3 | |
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| 4 | #include <linux/bpf.h> |
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| 5 | #include <stdint.h> |
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| 6 | #include <bpf/bpf_helpers.h> |
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| 7 | #include <bpf/bpf_core_read.h> |
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| 8 | |
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| 9 | char _license[] SEC("license" ) = "GPL" ; |
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| 10 | |
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| 11 | struct { |
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| 12 | char in[256]; |
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| 13 | char out[256]; |
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| 14 | } data = {}; |
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| 15 | |
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| 16 | struct core_reloc_misc_output { |
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| 17 | int a, b, c; |
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| 18 | }; |
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| 19 | |
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| 20 | struct core_reloc_misc___a { |
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| 21 | int a1; |
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| 22 | int a2; |
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| 23 | }; |
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| 24 | |
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| 25 | struct core_reloc_misc___b { |
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| 26 | int b1; |
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| 27 | int b2; |
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| 28 | }; |
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| 29 | |
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| 30 | /* fixed two first members, can be extended with new fields */ |
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| 31 | struct core_reloc_misc_extensible { |
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| 32 | int a; |
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| 33 | int b; |
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| 34 | }; |
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| 35 | |
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| 36 | #define CORE_READ(dst, src) bpf_core_read(dst, sizeof(*(dst)), src) |
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| 37 | |
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| 38 | SEC("raw_tracepoint/sys_enter" ) |
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| 39 | int test_core_misc(void *ctx) |
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| 40 | { |
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| 41 | struct core_reloc_misc___a *in_a = (void *)&data.in; |
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| 42 | struct core_reloc_misc___b *in_b = (void *)&data.in; |
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| 43 | struct core_reloc_misc_extensible *in_ext = (void *)&data.in; |
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| 44 | struct core_reloc_misc_output *out = (void *)&data.out; |
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| 45 | |
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| 46 | /* record two different relocations with the same accessor string */ |
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| 47 | if (CORE_READ(&out->a, &in_a->a1) || /* accessor: 0:0 */ |
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| 48 | CORE_READ(&out->b, &in_b->b1)) /* accessor: 0:0 */ |
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| 49 | return 1; |
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| 50 | |
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| 51 | /* Validate relocations capture array-only accesses for structs with |
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| 52 | * fixed header, but with potentially extendable tail. This will read |
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| 53 | * first 4 bytes of 2nd element of in_ext array of potentially |
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| 54 | * variably sized struct core_reloc_misc_extensible. */ |
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| 55 | if (CORE_READ(&out->c, &in_ext[2])) /* accessor: 2 */ |
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| 56 | return 1; |
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| 57 | |
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| 58 | return 0; |
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| 59 | } |
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| 60 | |
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| 61 | |
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