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 8 extern int LINUX_KERNEL_VERSION __kconfig; 9 /* this weak extern will be strict due to the other file's strong extern */ 10 extern bool CONFIG_BPF_SYSCALL __kconfig __weak; 11 extern const void bpf_link_fops __ksym __weak; 12 13 int input_bss1; 14 int input_data1 = 1; 15 const volatile int input_rodata1 = 11; 16 17 int input_bss_weak __weak; 18 /* these two definitions should win */ 19 int input_data_weak __weak = 10; 20 const volatile int input_rodata_weak __weak = 100; 21 22 extern int input_bss2; 23 extern int input_data2; 24 extern const int input_rodata2; 25 26 int output_bss1; 27 int output_data1; 28 int output_rodata1; 29 30 long output_sink1; 31 32 static __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 38 SEC("raw_tp/sys_enter") 39 int 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 54 char LICENSE[] SEC("license") = "GPL"; 55