linked_vars1.c (1382B)
1// SPDX-License-Identifier: GPL-2.0 2/* Copyright (c) 2021 Facebook */ 3 4#include "vmlinux.h" 5#include <bpf/bpf_helpers.h> 6#include <bpf/bpf_tracing.h> 7 8extern int LINUX_KERNEL_VERSION __kconfig; 9/* this weak extern will be strict due to the other file's strong extern */ 10extern bool CONFIG_BPF_SYSCALL __kconfig __weak; 11extern const void bpf_link_fops __ksym __weak; 12 13int input_bss1; 14int input_data1 = 1; 15const volatile int input_rodata1 = 11; 16 17int input_bss_weak __weak; 18/* these two definitions should win */ 19int input_data_weak __weak = 10; 20const volatile int input_rodata_weak __weak = 100; 21 22extern int input_bss2; 23extern int input_data2; 24extern const int input_rodata2; 25 26int output_bss1; 27int output_data1; 28int output_rodata1; 29 30long output_sink1; 31 32static __noinline int get_bss_res(void) 33{ 34 /* just make sure all the relocations work against .text as well */ 35 return input_bss1 + input_bss2 + input_bss_weak; 36} 37 38SEC("raw_tp/sys_enter") 39int BPF_PROG(handler1) 40{ 41 output_bss1 = get_bss_res(); 42 output_data1 = input_data1 + input_data2 + input_data_weak; 43 output_rodata1 = input_rodata1 + input_rodata2 + input_rodata_weak; 44 45 /* make sure we actually use above special externs, otherwise compiler 46 * will optimize them out 47 */ 48 output_sink1 = LINUX_KERNEL_VERSION 49 + CONFIG_BPF_SYSCALL 50 + (long)&bpf_link_fops; 51 return 0; 52} 53 54char LICENSE[] SEC("license") = "GPL";