1 // SPDX-License-Identifier: GPL-2.0 2 #include <linux/bpf.h> 3 #include <bpf/bpf_helpers.h> 4 #include <bpf/bpf_tracing.h> 5 #include <stdbool.h> 6 #include "bpf_kfuncs.h" 7 8 #define ARRAY_SIZE(x) (int)(sizeof(x) / sizeof((x)[0])) 9 10 char _license[] SEC("license") = "GPL"; 11 12 extern const void bpf_fentry_test1 __ksym; 13 extern const void bpf_fentry_test2 __ksym; 14 extern const void bpf_fentry_test3 __ksym; 15 extern const void bpf_fentry_test4 __ksym; 16 extern const void bpf_fentry_test5 __ksym; 17 extern const void bpf_fentry_test6 __ksym; 18 extern const void bpf_fentry_test7 __ksym; 19 extern const void bpf_fentry_test8 __ksym; 20 21 int pid = 0; 22 23 __u64 kprobe_session_result[8]; 24 25 static int session_check(void *ctx) 26 { 27 unsigned int i; 28 __u64 addr; 29 const void *kfuncs[] = { 30 &bpf_fentry_test1, 31 &bpf_fentry_test2, 32 &bpf_fentry_test3, 33 &bpf_fentry_test4, 34 &bpf_fentry_test5, 35 &bpf_fentry_test6, 36 &bpf_fentry_test7, 37 &bpf_fentry_test8, 38 }; 39 40 if (bpf_get_current_pid_tgid() >> 32 != pid) 41 return 1; 42 43 addr = bpf_get_func_ip(ctx); 44 45 for (i = 0; i < ARRAY_SIZE(kfuncs); i++) { 46 if (kfuncs[i] == (void *) addr) { 47 kprobe_session_result[i]++; 48 break; 49 } 50 } 51 52 /* 53 * Force probes for function bpf_fentry_test[5-8] not to 54 * install and execute the return probe 55 */ 56 if (((const void *) addr == &bpf_fentry_test5) || 57 ((const void *) addr == &bpf_fentry_test6) || 58 ((const void *) addr == &bpf_fentry_test7) || 59 ((const void *) addr == &bpf_fentry_test8)) 60 return 1; 61 62 return 0; 63 } 64 65 /* 66 * No tests in here, just to trigger 'bpf_fentry_test*' 67 * through tracing test_run 68 */ 69 SEC("fentry/bpf_modify_return_test") 70 int BPF_PROG(trigger) 71 { 72 return 0; 73 } 74 75 SEC("kprobe.session/bpf_fentry_test*") 76 int test_kprobe(struct pt_regs *ctx) 77 { 78 return session_check(ctx); 79 } 80