tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Test weak ksyms.
4 *
5 * Copyright (c) 2021 Google
6 */
7
8#include "vmlinux.h"
9
10#include <bpf/bpf_helpers.h>
11
12int out__existing_typed = -1;
13__u64 out__existing_typeless = -1;
14
15__u64 out__non_existent_typeless = -1;
16__u64 out__non_existent_typed = -1;
17
18/* existing weak symbols */
19
20/* test existing weak symbols can be resolved. */
21extern const struct rq runqueues __ksym __weak; /* typed */
22extern const void bpf_prog_active __ksym __weak; /* typeless */
23
24
25/* non-existent weak symbols. */
26
27/* typeless symbols, default to zero. */
28extern const void bpf_link_fops1 __ksym __weak;
29
30/* typed symbols, default to zero. */
31extern const int bpf_link_fops2 __ksym __weak;
32
33SEC("raw_tp/sys_enter")
34int pass_handler(const void *ctx)
35{
36 struct rq *rq;
37
38 /* tests existing symbols. */
39 rq = (struct rq *)bpf_per_cpu_ptr(&runqueues, 0);
40 if (rq)
41 out__existing_typed = 0;
42 out__existing_typeless = (__u64)&bpf_prog_active;
43
44 /* tests non-existent symbols. */
45 out__non_existent_typeless = (__u64)&bpf_link_fops1;
46
47 /* tests non-existent symbols. */
48 out__non_existent_typed = (__u64)&bpf_link_fops2;
49
50 if (&bpf_link_fops2) /* can't happen */
51 out__non_existent_typed = (__u64)bpf_per_cpu_ptr(&bpf_link_fops2, 0);
52
53 return 0;
54}
55
56char _license[] SEC("license") = "GPL";