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1// SPDX-License-Identifier: GPL-2.02/*3 * Test weak ksyms.4 *5 * Copyright (c) 2021 Google6 */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 */23struct task_struct *bpf_task_acquire(struct task_struct *p) __ksym __weak;24void bpf_testmod_test_mod_kfunc(int i) __ksym __weak;25 26 27/* non-existent weak symbols. */28 29/* typeless symbols, default to zero. */30extern const void bpf_link_fops1 __ksym __weak;31 32/* typed symbols, default to zero. */33extern const int bpf_link_fops2 __ksym __weak;34void invalid_kfunc(void) __ksym __weak;35 36SEC("raw_tp/sys_enter")37int pass_handler(const void *ctx)38{39 struct rq *rq;40 41 /* tests existing symbols. */42 rq = (struct rq *)bpf_per_cpu_ptr(&runqueues, 0);43 if (rq && bpf_ksym_exists(&runqueues))44 out__existing_typed = rq->cpu;45 out__existing_typeless = (__u64)&bpf_prog_active;46 47 /* tests non-existent symbols. */48 out__non_existent_typeless = (__u64)&bpf_link_fops1;49 50 /* tests non-existent symbols. */51 out__non_existent_typed = (__u64)&bpf_link_fops2;52 53 if (&bpf_link_fops2) /* can't happen */54 out__non_existent_typed = (__u64)bpf_per_cpu_ptr(&bpf_link_fops2, 0);55 56 if (!bpf_ksym_exists(bpf_task_acquire))57 /* dead code won't be seen by the verifier */58 bpf_task_acquire(0);59 60 if (!bpf_ksym_exists(bpf_testmod_test_mod_kfunc))61 /* dead code won't be seen by the verifier */62 bpf_testmod_test_mod_kfunc(0);63 64 if (bpf_ksym_exists(invalid_kfunc))65 /* dead code won't be seen by the verifier */66 invalid_kfunc();67 68 return 0;69}70 71char _license[] SEC("license") = "GPL";72