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1 // SPDX-License-Identifier: GPL-2.0
2 #define _GNU_SOURCE
3 #include <pthread.h>
4 #include <sched.h>
5 #include <sys/socket.h>
6 #include <test_progs.h>
7 
8 #define MAX_CNT_RAWTP	10ull
9 #define MAX_STACK_RAWTP	100
10 
11 static int duration = 0;
12 
13 struct get_stack_trace_t {
14 	int pid;
15 	int kern_stack_size;
16 	int user_stack_size;
17 	int user_stack_buildid_size;
18 	__u64 kern_stack[MAX_STACK_RAWTP];
19 	__u64 user_stack[MAX_STACK_RAWTP];
20 	struct bpf_stack_build_id user_stack_buildid[MAX_STACK_RAWTP];
21 };
22 
get_stack_print_output(void * ctx,int cpu,void * data,__u32 size)23 static void get_stack_print_output(void *ctx, int cpu, void *data, __u32 size)
24 {
25 	bool good_kern_stack = false, good_user_stack = false;
26 	const char *nonjit_func = "___bpf_prog_run";
27 	/* perfbuf-submitted data is 4-byte aligned, but we need 8-byte
28 	 * alignment, so copy data into a local variable, for simplicity
29 	 */
30 	struct get_stack_trace_t e;
31 	int i, num_stack;
32 	struct ksym *ks;
33 
34 	memset(&e, 0, sizeof(e));
35 	memcpy(&e, data, size <= sizeof(e) ? size : sizeof(e));
36 
37 	if (size < sizeof(struct get_stack_trace_t)) {
38 		__u64 *raw_data = data;
39 		bool found = false;
40 
41 		num_stack = size / sizeof(__u64);
42 		/* If jit is enabled, we do not have a good way to
43 		 * verify the sanity of the kernel stack. So we
44 		 * just assume it is good if the stack is not empty.
45 		 * This could be improved in the future.
46 		 */
47 		if (env.jit_enabled) {
48 			found = num_stack > 0;
49 		} else {
50 			for (i = 0; i < num_stack; i++) {
51 				ks = ksym_search(raw_data[i]);
52 				if (ks && (strcmp(ks->name, nonjit_func) == 0)) {
53 					found = true;
54 					break;
55 				}
56 			}
57 		}
58 		if (found) {
59 			good_kern_stack = true;
60 			good_user_stack = true;
61 		}
62 	} else {
63 		num_stack = e.kern_stack_size / sizeof(__u64);
64 		if (env.jit_enabled) {
65 			good_kern_stack = num_stack > 0;
66 		} else {
67 			for (i = 0; i < num_stack; i++) {
68 				ks = ksym_search(e.kern_stack[i]);
69 				if (ks && (strcmp(ks->name, nonjit_func) == 0)) {
70 					good_kern_stack = true;
71 					break;
72 				}
73 			}
74 		}
75 		if (e.user_stack_size > 0 && e.user_stack_buildid_size > 0)
76 			good_user_stack = true;
77 	}
78 
79 	if (!good_kern_stack)
80 	    CHECK(!good_kern_stack, "kern_stack", "corrupted kernel stack\n");
81 	if (!good_user_stack)
82 	    CHECK(!good_user_stack, "user_stack", "corrupted user stack\n");
83 }
84 
test_get_stack_raw_tp(void)85 void test_get_stack_raw_tp(void)
86 {
87 	const char *file = "./test_get_stack_rawtp.bpf.o";
88 	const char *file_err = "./test_get_stack_rawtp_err.bpf.o";
89 	const char *prog_name = "bpf_prog1";
90 	int i, err, prog_fd, exp_cnt = MAX_CNT_RAWTP;
91 	struct perf_buffer *pb = NULL;
92 	struct bpf_link *link = NULL;
93 	struct timespec tv = {0, 10};
94 	struct bpf_program *prog;
95 	struct bpf_object *obj;
96 	struct bpf_map *map;
97 	cpu_set_t cpu_set;
98 
99 	err = bpf_prog_test_load(file_err, BPF_PROG_TYPE_RAW_TRACEPOINT, &obj, &prog_fd);
100 	if (CHECK(err >= 0, "prog_load raw tp", "err %d errno %d\n", err, errno))
101 		return;
102 
103 	err = bpf_prog_test_load(file, BPF_PROG_TYPE_RAW_TRACEPOINT, &obj, &prog_fd);
104 	if (CHECK(err, "prog_load raw tp", "err %d errno %d\n", err, errno))
105 		return;
106 
107 	prog = bpf_object__find_program_by_name(obj, prog_name);
108 	if (CHECK(!prog, "find_probe", "prog '%s' not found\n", prog_name))
109 		goto close_prog;
110 
111 	map = bpf_object__find_map_by_name(obj, "perfmap");
112 	if (CHECK(!map, "bpf_find_map", "not found\n"))
113 		goto close_prog;
114 
115 	err = load_kallsyms();
116 	if (CHECK(err < 0, "load_kallsyms", "err %d errno %d\n", err, errno))
117 		goto close_prog;
118 
119 	CPU_ZERO(&cpu_set);
120 	CPU_SET(0, &cpu_set);
121 	err = pthread_setaffinity_np(pthread_self(), sizeof(cpu_set), &cpu_set);
122 	if (CHECK(err, "set_affinity", "err %d, errno %d\n", err, errno))
123 		goto close_prog;
124 
125 	link = bpf_program__attach_raw_tracepoint(prog, "sys_enter");
126 	if (!ASSERT_OK_PTR(link, "attach_raw_tp"))
127 		goto close_prog;
128 
129 	pb = perf_buffer__new(bpf_map__fd(map), 8, get_stack_print_output,
130 			      NULL, NULL, NULL);
131 	if (!ASSERT_OK_PTR(pb, "perf_buf__new"))
132 		goto close_prog;
133 
134 	/* trigger some syscall action */
135 	for (i = 0; i < MAX_CNT_RAWTP; i++)
136 		nanosleep(&tv, NULL);
137 
138 	while (exp_cnt > 0) {
139 		err = perf_buffer__poll(pb, 100);
140 		if (err < 0 && CHECK(err < 0, "pb__poll", "err %d\n", err))
141 			goto close_prog;
142 		exp_cnt -= err;
143 	}
144 
145 close_prog:
146 	bpf_link__destroy(link);
147 	perf_buffer__free(pb);
148 	bpf_object__close(obj);
149 }
150