1 // SPDX-License-Identifier: GPL-2.0 2 /* Copyright (c) 2021 Google LLC. */ 3 4 #include <linux/bpf.h> 5 #include <bpf/bpf_helpers.h> 6 #include <bpf/bpf_tracing.h> 7 8 char num_out[64] = {}; 9 long num_ret = 0; 10 11 char ip_out[64] = {}; 12 long ip_ret = 0; 13 14 char sym_out[64] = {}; 15 long sym_ret = 0; 16 17 char addr_out[64] = {}; 18 long addr_ret = 0; 19 20 char str_out[64] = {}; 21 long str_ret = 0; 22 23 char over_out[6] = {}; 24 long over_ret = 0; 25 26 char pad_out[10] = {}; 27 long pad_ret = 0; 28 29 char noarg_out[64] = {}; 30 long noarg_ret = 0; 31 32 long nobuf_ret = 0; 33 34 extern const void schedule __ksym; 35 36 SEC("raw_tp/sys_enter") 37 int handler(const void *ctx) 38 { 39 /* Convenient values to pretty-print */ 40 const __u8 ex_ipv4[] = {127, 0, 0, 1}; 41 const __u8 ex_ipv6[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1}; 42 static const char str1[] = "str1"; 43 static const char longstr[] = "longstr"; 44 45 /* Integer types */ 46 num_ret = BPF_SNPRINTF(num_out, sizeof(num_out), 47 "%d %u %x %li %llu %lX", 48 -8, 9, 150, -424242, 1337, 0xDABBAD00); 49 /* IP addresses */ 50 ip_ret = BPF_SNPRINTF(ip_out, sizeof(ip_out), "%pi4 %pI6", 51 &ex_ipv4, &ex_ipv6); 52 /* Symbol lookup formatting */ 53 sym_ret = BPF_SNPRINTF(sym_out, sizeof(sym_out), "%ps %pS %pB", 54 &schedule, &schedule, &schedule); 55 /* Kernel pointers */ 56 addr_ret = BPF_SNPRINTF(addr_out, sizeof(addr_out), "%pK %px %p", 57 0, 0xFFFF00000ADD4E55, 0xFFFF00000ADD4E55); 58 /* Strings embedding */ 59 str_ret = BPF_SNPRINTF(str_out, sizeof(str_out), "%s %+05s", 60 str1, longstr); 61 /* Overflow */ 62 over_ret = BPF_SNPRINTF(over_out, sizeof(over_out), "%%overflow"); 63 /* Padding of fixed width numbers */ 64 pad_ret = BPF_SNPRINTF(pad_out, sizeof(pad_out), "%5d %0900000X", 4, 4); 65 /* No args */ 66 noarg_ret = BPF_SNPRINTF(noarg_out, sizeof(noarg_out), "simple case"); 67 /* No buffer */ 68 nobuf_ret = BPF_SNPRINTF(NULL, 0, "only interested in length %d", 60); 69 70 return 0; 71 } 72 73 char _license[] SEC("license") = "GPL"; 74