xref: /linux/tools/testing/selftests/bpf/progs/test_attach_probe.c (revision 06a130e42a5bfc84795464bff023bff4c16f58c5)
1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (c) 2017 Facebook
3 
4 #include "vmlinux.h"
5 #include <bpf/bpf_helpers.h>
6 #include <bpf/bpf_tracing.h>
7 #include <bpf/bpf_core_read.h>
8 #include <errno.h>
9 #include "bpf_misc.h"
10 
11 u32 dynamic_sz = 1;
12 int kprobe2_res = 0;
13 int kretprobe2_res = 0;
14 int uprobe_byname_res = 0;
15 int uretprobe_byname_res = 0;
16 int uprobe_byname2_res = 0;
17 int uretprobe_byname2_res = 0;
18 int uprobe_byname3_sleepable_res = 0;
19 int uprobe_byname3_str_sleepable_res = 0;
20 int uprobe_byname3_res = 0;
21 int uretprobe_byname3_sleepable_res = 0;
22 int uretprobe_byname3_str_sleepable_res = 0;
23 int uretprobe_byname3_res = 0;
24 void *user_ptr = 0;
25 
26 int bpf_copy_from_user_str(void *dst, u32, const void *, u64) __weak __ksym;
27 
28 SEC("ksyscall/nanosleep")
29 int BPF_KSYSCALL(handle_kprobe_auto, struct __kernel_timespec *req, struct __kernel_timespec *rem)
30 {
31 	kprobe2_res = 11;
32 	return 0;
33 }
34 
35 SEC("kretsyscall/nanosleep")
36 int BPF_KRETPROBE(handle_kretprobe_auto, int ret)
37 {
38 	kretprobe2_res = 22;
39 	return ret;
40 }
41 
42 SEC("uprobe")
43 int handle_uprobe_ref_ctr(struct pt_regs *ctx)
44 {
45 	return 0;
46 }
47 
48 SEC("uretprobe")
49 int handle_uretprobe_ref_ctr(struct pt_regs *ctx)
50 {
51 	return 0;
52 }
53 
54 SEC("uprobe")
55 int handle_uprobe_byname(struct pt_regs *ctx)
56 {
57 	uprobe_byname_res = 5;
58 	return 0;
59 }
60 
61 /* use auto-attach format for section definition. */
62 SEC("uretprobe//proc/self/exe:trigger_func2")
63 int handle_uretprobe_byname(struct pt_regs *ctx)
64 {
65 	uretprobe_byname_res = 6;
66 	return 0;
67 }
68 
69 SEC("uprobe")
70 int BPF_UPROBE(handle_uprobe_byname2, const char *pathname, const char *mode)
71 {
72 	char mode_buf[2] = {};
73 
74 	/* verify fopen mode */
75 	bpf_probe_read_user(mode_buf, sizeof(mode_buf), mode);
76 	if (mode_buf[0] == 'r' && mode_buf[1] == 0)
77 		uprobe_byname2_res = 7;
78 	return 0;
79 }
80 
81 SEC("uretprobe")
82 int BPF_URETPROBE(handle_uretprobe_byname2, void *ret)
83 {
84 	uretprobe_byname2_res = 8;
85 	return 0;
86 }
87 
88 static __always_inline bool verify_sleepable_user_copy(void)
89 {
90 	char data[9];
91 
92 	bpf_copy_from_user(data, sizeof(data), user_ptr);
93 	return bpf_strncmp(data, sizeof(data), "test_data") == 0;
94 }
95 
96 static __always_inline bool verify_sleepable_user_copy_str(void)
97 {
98 	int ret;
99 	char data_long[20];
100 	char data_long_pad[20];
101 	char data_long_err[20];
102 	char data_short[4];
103 	char data_short_pad[4];
104 
105 	ret = bpf_copy_from_user_str(data_short, sizeof(data_short), user_ptr, 0);
106 
107 	if (bpf_strncmp(data_short, 4, "tes\0") != 0 || ret != 4)
108 		return false;
109 
110 	ret = bpf_copy_from_user_str(data_short_pad, sizeof(data_short_pad), user_ptr, BPF_F_PAD_ZEROS);
111 
112 	if (bpf_strncmp(data_short, 4, "tes\0") != 0 || ret != 4)
113 		return false;
114 
115 	/* Make sure this passes the verifier */
116 	ret = bpf_copy_from_user_str(data_long, dynamic_sz & sizeof(data_long), user_ptr, 0);
117 
118 	if (ret != 0)
119 		return false;
120 
121 	ret = bpf_copy_from_user_str(data_long, sizeof(data_long), user_ptr, 0);
122 
123 	if (bpf_strncmp(data_long, 10, "test_data\0") != 0 || ret != 10)
124 		return false;
125 
126 	ret = bpf_copy_from_user_str(data_long_pad, sizeof(data_long_pad), user_ptr, BPF_F_PAD_ZEROS);
127 
128 	if (bpf_strncmp(data_long_pad, 10, "test_data\0") != 0 || ret != 10 || data_long_pad[19] != '\0')
129 		return false;
130 
131 	ret = bpf_copy_from_user_str(data_long_err, sizeof(data_long_err), (void *)data_long, BPF_F_PAD_ZEROS);
132 
133 	if (ret > 0 || data_long_err[19] != '\0')
134 		return false;
135 
136 	ret = bpf_copy_from_user_str(data_long, sizeof(data_long), user_ptr, 2);
137 
138 	if (ret != -EINVAL)
139 		return false;
140 
141 	return true;
142 }
143 
144 SEC("uprobe.s//proc/self/exe:trigger_func3")
145 int handle_uprobe_byname3_sleepable(struct pt_regs *ctx)
146 {
147 	if (verify_sleepable_user_copy())
148 		uprobe_byname3_sleepable_res = 9;
149 	if (verify_sleepable_user_copy_str())
150 		uprobe_byname3_str_sleepable_res = 10;
151 	return 0;
152 }
153 
154 /**
155  * same target as the uprobe.s above to force sleepable and non-sleepable
156  * programs in the same bpf_prog_array
157  */
158 SEC("uprobe//proc/self/exe:trigger_func3")
159 int handle_uprobe_byname3(struct pt_regs *ctx)
160 {
161 	uprobe_byname3_res = 11;
162 	return 0;
163 }
164 
165 SEC("uretprobe.s//proc/self/exe:trigger_func3")
166 int handle_uretprobe_byname3_sleepable(struct pt_regs *ctx)
167 {
168 	if (verify_sleepable_user_copy())
169 		uretprobe_byname3_sleepable_res = 12;
170 	if (verify_sleepable_user_copy_str())
171 		uretprobe_byname3_str_sleepable_res = 13;
172 	return 0;
173 }
174 
175 SEC("uretprobe//proc/self/exe:trigger_func3")
176 int handle_uretprobe_byname3(struct pt_regs *ctx)
177 {
178 	uretprobe_byname3_res = 14;
179 	return 0;
180 }
181 
182 
183 char _license[] SEC("license") = "GPL";
184