// 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;
}