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// SPDX-License-Identifier: GPL-2.0 // Copyright (c) 2019 Facebook #include <linux/bpf.h> #include <stdint.h> #include <bpf/bpf_helpers.h> #include <bpf/bpf_core_read.h> char _license[] SEC("license") = "GPL"; struct { char in[256]; char out[256]; } data = {}; struct core_reloc_misc_output { int a, b, c; }; struct core_reloc_misc___a { int a1; int a2; }; struct core_reloc_misc___b { int b1; int b2; }; /* fixed two first members, can be extended with new fields */ struct core_reloc_misc_extensible { int a; int b; }; #define CORE_READ(dst, src) bpf_core_read(dst, sizeof(*(dst)), src) SEC("raw_tracepoint/sys_enter") int test_core_misc(void *ctx) { struct core_reloc_misc___a *in_a = (void *)&data.in; struct core_reloc_misc___b *in_b = (void *)&data.in; struct core_reloc_misc_extensible *in_ext = (void *)&data.in; struct core_reloc_misc_output *out = (void *)&data.out; /* record two different relocations with the same accessor string */ if (CORE_READ(&out->a, &in_a->a1) || /* accessor: 0:0 */ CORE_READ(&out->b, &in_b->b1)) /* accessor: 0:0 */ return 1; /* Validate relocations capture array-only accesses for structs with * fixed header, but with potentially extendable tail. This will read * first 4 bytes of 2nd element of in_ext array of potentially * variably sized struct core_reloc_misc_extensible. */ if (CORE_READ(&out->c, &in_ext[2])) /* accessor: 2 */ return 1; return 0; }