linked_vars2.c (1383B)
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/* when an extern is defined as both strong and weak, resulting symbol will be strong */ 10extern bool CONFIG_BPF_SYSCALL __kconfig; 11extern const void __start_BTF __ksym; 12 13int input_bss2; 14int input_data2 = 2; 15const volatile int input_rodata2 = 22; 16 17int input_bss_weak __weak; 18/* these two weak variables should lose */ 19int input_data_weak __weak = 20; 20const volatile int input_rodata_weak __weak = 200; 21 22extern int input_bss1; 23extern int input_data1; 24extern const int input_rodata1; 25 26int output_bss2; 27int output_data2; 28int output_rodata2; 29 30int output_sink2; 31 32static __noinline int get_data_res(void) 33{ 34 /* just make sure all the relocations work against .text as well */ 35 return input_data1 + input_data2 + input_data_weak; 36} 37 38SEC("raw_tp/sys_enter") 39int BPF_PROG(handler2) 40{ 41 output_bss2 = input_bss1 + input_bss2 + input_bss_weak; 42 output_data2 = get_data_res(); 43 output_rodata2 = 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_sink2 = LINUX_KERNEL_VERSION 49 + CONFIG_BPF_SYSCALL 50 + (long)&__start_BTF; 51 52 return 0; 53} 54 55char LICENSE[] SEC("license") = "GPL";