tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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__u32 pid = 0;
9
10char num_out[64] = {};
11long num_ret = 0;
12
13char ip_out[64] = {};
14long ip_ret = 0;
15
16char sym_out[64] = {};
17long sym_ret = 0;
18
19char addr_out[64] = {};
20long addr_ret = 0;
21
22char str_out[64] = {};
23long str_ret = 0;
24
25char over_out[6] = {};
26long over_ret = 0;
27
28char pad_out[10] = {};
29long pad_ret = 0;
30
31char noarg_out[64] = {};
32long noarg_ret = 0;
33
34long nobuf_ret = 0;
35
36extern const void schedule __ksym;
37
38SEC("raw_tp/sys_enter")
39int handler(const void *ctx)
40{
41 /* Convenient values to pretty-print */
42 const __u8 ex_ipv4[] = {127, 0, 0, 1};
43 const __u8 ex_ipv6[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1};
44 static const char str1[] = "str1";
45 static const char longstr[] = "longstr";
46
47 if ((int)bpf_get_current_pid_tgid() != pid)
48 return 0;
49
50 /* Integer types */
51 num_ret = BPF_SNPRINTF(num_out, sizeof(num_out),
52 "%d %u %x %li %llu %lX",
53 -8, 9, 150, -424242, 1337, 0xDABBAD00);
54 /* IP addresses */
55 ip_ret = BPF_SNPRINTF(ip_out, sizeof(ip_out), "%pi4 %pI6",
56 &ex_ipv4, &ex_ipv6);
57 /* Symbol lookup formatting */
58 sym_ret = BPF_SNPRINTF(sym_out, sizeof(sym_out), "%ps %pS %pB",
59 &schedule, &schedule, &schedule);
60 /* Kernel pointers */
61 addr_ret = BPF_SNPRINTF(addr_out, sizeof(addr_out), "%pK %px %p",
62 0, 0xFFFF00000ADD4E55, 0xFFFF00000ADD4E55);
63 /* Strings embedding */
64 str_ret = BPF_SNPRINTF(str_out, sizeof(str_out), "%s %+05s",
65 str1, longstr);
66 /* Overflow */
67 over_ret = BPF_SNPRINTF(over_out, sizeof(over_out), "%%overflow");
68 /* Padding of fixed width numbers */
69 pad_ret = BPF_SNPRINTF(pad_out, sizeof(pad_out), "%5d %0900000X", 4, 4);
70 /* No args */
71 noarg_ret = BPF_SNPRINTF(noarg_out, sizeof(noarg_out), "simple case");
72 /* No buffer */
73 nobuf_ret = BPF_SNPRINTF(NULL, 0, "only interested in length %d", 60);
74
75 return 0;
76}
77
78char _license[] SEC("license") = "GPL";