Merge tag 'gfs2-for-5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux...
[linux-2.6-microblaze.git] / samples / bpf / task_fd_query_user.c
1 // SPDX-License-Identifier: GPL-2.0
2
3 #include <stdio.h>
4 #include <stdlib.h>
5 #include <signal.h>
6 #include <unistd.h>
7 #include <stdbool.h>
8 #include <string.h>
9 #include <stdint.h>
10 #include <fcntl.h>
11 #include <linux/bpf.h>
12 #include <sys/ioctl.h>
13 #include <sys/resource.h>
14 #include <sys/types.h>
15 #include <sys/stat.h>
16 #include <linux/perf_event.h>
17
18 #include <bpf/libbpf.h>
19 #include "bpf_load.h"
20 #include "bpf_util.h"
21 #include "perf-sys.h"
22 #include "trace_helpers.h"
23
24 #define CHECK_PERROR_RET(condition) ({                  \
25         int __ret = !!(condition);                      \
26         if (__ret) {                                    \
27                 printf("FAIL: %s:\n", __func__);        \
28                 perror("    ");                 \
29                 return -1;                              \
30         }                                               \
31 })
32
33 #define CHECK_AND_RET(condition) ({                     \
34         int __ret = !!(condition);                      \
35         if (__ret)                                      \
36                 return -1;                              \
37 })
38
39 static __u64 ptr_to_u64(void *ptr)
40 {
41         return (__u64) (unsigned long) ptr;
42 }
43
44 #define PMU_TYPE_FILE "/sys/bus/event_source/devices/%s/type"
45 static int bpf_find_probe_type(const char *event_type)
46 {
47         char buf[256];
48         int fd, ret;
49
50         ret = snprintf(buf, sizeof(buf), PMU_TYPE_FILE, event_type);
51         CHECK_PERROR_RET(ret < 0 || ret >= sizeof(buf));
52
53         fd = open(buf, O_RDONLY);
54         CHECK_PERROR_RET(fd < 0);
55
56         ret = read(fd, buf, sizeof(buf));
57         close(fd);
58         CHECK_PERROR_RET(ret < 0 || ret >= sizeof(buf));
59
60         errno = 0;
61         ret = (int)strtol(buf, NULL, 10);
62         CHECK_PERROR_RET(errno);
63         return ret;
64 }
65
66 #define PMU_RETPROBE_FILE "/sys/bus/event_source/devices/%s/format/retprobe"
67 static int bpf_get_retprobe_bit(const char *event_type)
68 {
69         char buf[256];
70         int fd, ret;
71
72         ret = snprintf(buf, sizeof(buf), PMU_RETPROBE_FILE, event_type);
73         CHECK_PERROR_RET(ret < 0 || ret >= sizeof(buf));
74
75         fd = open(buf, O_RDONLY);
76         CHECK_PERROR_RET(fd < 0);
77
78         ret = read(fd, buf, sizeof(buf));
79         close(fd);
80         CHECK_PERROR_RET(ret < 0 || ret >= sizeof(buf));
81         CHECK_PERROR_RET(strlen(buf) < strlen("config:"));
82
83         errno = 0;
84         ret = (int)strtol(buf + strlen("config:"), NULL, 10);
85         CHECK_PERROR_RET(errno);
86         return ret;
87 }
88
89 static int test_debug_fs_kprobe(int prog_fd_idx, const char *fn_name,
90                                 __u32 expected_fd_type)
91 {
92         __u64 probe_offset, probe_addr;
93         __u32 len, prog_id, fd_type;
94         char buf[256];
95         int err;
96
97         len = sizeof(buf);
98         err = bpf_task_fd_query(getpid(), event_fd[prog_fd_idx], 0, buf, &len,
99                                 &prog_id, &fd_type, &probe_offset,
100                                 &probe_addr);
101         if (err < 0) {
102                 printf("FAIL: %s, for event_fd idx %d, fn_name %s\n",
103                        __func__, prog_fd_idx, fn_name);
104                 perror("    :");
105                 return -1;
106         }
107         if (strcmp(buf, fn_name) != 0 ||
108             fd_type != expected_fd_type ||
109             probe_offset != 0x0 || probe_addr != 0x0) {
110                 printf("FAIL: bpf_trace_event_query(event_fd[%d]):\n",
111                        prog_fd_idx);
112                 printf("buf: %s, fd_type: %u, probe_offset: 0x%llx,"
113                        " probe_addr: 0x%llx\n",
114                        buf, fd_type, probe_offset, probe_addr);
115                 return -1;
116         }
117         return 0;
118 }
119
120 static int test_nondebug_fs_kuprobe_common(const char *event_type,
121         const char *name, __u64 offset, __u64 addr, bool is_return,
122         char *buf, __u32 *buf_len, __u32 *prog_id, __u32 *fd_type,
123         __u64 *probe_offset, __u64 *probe_addr)
124 {
125         int is_return_bit = bpf_get_retprobe_bit(event_type);
126         int type = bpf_find_probe_type(event_type);
127         struct perf_event_attr attr = {};
128         int fd;
129
130         if (type < 0 || is_return_bit < 0) {
131                 printf("FAIL: %s incorrect type (%d) or is_return_bit (%d)\n",
132                         __func__, type, is_return_bit);
133                 return -1;
134         }
135
136         attr.sample_period = 1;
137         attr.wakeup_events = 1;
138         if (is_return)
139                 attr.config |= 1 << is_return_bit;
140
141         if (name) {
142                 attr.config1 = ptr_to_u64((void *)name);
143                 attr.config2 = offset;
144         } else {
145                 attr.config1 = 0;
146                 attr.config2 = addr;
147         }
148         attr.size = sizeof(attr);
149         attr.type = type;
150
151         fd = sys_perf_event_open(&attr, -1, 0, -1, 0);
152         CHECK_PERROR_RET(fd < 0);
153
154         CHECK_PERROR_RET(ioctl(fd, PERF_EVENT_IOC_ENABLE, 0) < 0);
155         CHECK_PERROR_RET(ioctl(fd, PERF_EVENT_IOC_SET_BPF, prog_fd[0]) < 0);
156         CHECK_PERROR_RET(bpf_task_fd_query(getpid(), fd, 0, buf, buf_len,
157                          prog_id, fd_type, probe_offset, probe_addr) < 0);
158
159         return 0;
160 }
161
162 static int test_nondebug_fs_probe(const char *event_type, const char *name,
163                                   __u64 offset, __u64 addr, bool is_return,
164                                   __u32 expected_fd_type,
165                                   __u32 expected_ret_fd_type,
166                                   char *buf, __u32 buf_len)
167 {
168         __u64 probe_offset, probe_addr;
169         __u32 prog_id, fd_type;
170         int err;
171
172         err = test_nondebug_fs_kuprobe_common(event_type, name,
173                                               offset, addr, is_return,
174                                               buf, &buf_len, &prog_id,
175                                               &fd_type, &probe_offset,
176                                               &probe_addr);
177         if (err < 0) {
178                 printf("FAIL: %s, "
179                        "for name %s, offset 0x%llx, addr 0x%llx, is_return %d\n",
180                        __func__, name ? name : "", offset, addr, is_return);
181                 perror("    :");
182                 return -1;
183         }
184         if ((is_return && fd_type != expected_ret_fd_type) ||
185             (!is_return && fd_type != expected_fd_type)) {
186                 printf("FAIL: %s, incorrect fd_type %u\n",
187                        __func__, fd_type);
188                 return -1;
189         }
190         if (name) {
191                 if (strcmp(name, buf) != 0) {
192                         printf("FAIL: %s, incorrect buf %s\n", __func__, buf);
193                         return -1;
194                 }
195                 if (probe_offset != offset) {
196                         printf("FAIL: %s, incorrect probe_offset 0x%llx\n",
197                                __func__, probe_offset);
198                         return -1;
199                 }
200         } else {
201                 if (buf_len != 0) {
202                         printf("FAIL: %s, incorrect buf %p\n",
203                                __func__, buf);
204                         return -1;
205                 }
206
207                 if (probe_addr != addr) {
208                         printf("FAIL: %s, incorrect probe_addr 0x%llx\n",
209                                __func__, probe_addr);
210                         return -1;
211                 }
212         }
213         return 0;
214 }
215
216 static int test_debug_fs_uprobe(char *binary_path, long offset, bool is_return)
217 {
218         const char *event_type = "uprobe";
219         struct perf_event_attr attr = {};
220         char buf[256], event_alias[sizeof("test_1234567890")];
221         __u64 probe_offset, probe_addr;
222         __u32 len, prog_id, fd_type;
223         int err, res, kfd, efd;
224         ssize_t bytes;
225
226         snprintf(buf, sizeof(buf), "/sys/kernel/debug/tracing/%s_events",
227                  event_type);
228         kfd = open(buf, O_WRONLY | O_APPEND, 0);
229         CHECK_PERROR_RET(kfd < 0);
230
231         res = snprintf(event_alias, sizeof(event_alias), "test_%d", getpid());
232         CHECK_PERROR_RET(res < 0 || res >= sizeof(event_alias));
233
234         res = snprintf(buf, sizeof(buf), "%c:%ss/%s %s:0x%lx",
235                        is_return ? 'r' : 'p', event_type, event_alias,
236                        binary_path, offset);
237         CHECK_PERROR_RET(res < 0 || res >= sizeof(buf));
238         CHECK_PERROR_RET(write(kfd, buf, strlen(buf)) < 0);
239
240         close(kfd);
241         kfd = -1;
242
243         snprintf(buf, sizeof(buf), "/sys/kernel/debug/tracing/events/%ss/%s/id",
244                  event_type, event_alias);
245         efd = open(buf, O_RDONLY, 0);
246         CHECK_PERROR_RET(efd < 0);
247
248         bytes = read(efd, buf, sizeof(buf));
249         CHECK_PERROR_RET(bytes <= 0 || bytes >= sizeof(buf));
250         close(efd);
251         buf[bytes] = '\0';
252
253         attr.config = strtol(buf, NULL, 0);
254         attr.type = PERF_TYPE_TRACEPOINT;
255         attr.sample_period = 1;
256         attr.wakeup_events = 1;
257         kfd = sys_perf_event_open(&attr, -1, 0, -1, PERF_FLAG_FD_CLOEXEC);
258         CHECK_PERROR_RET(kfd < 0);
259         CHECK_PERROR_RET(ioctl(kfd, PERF_EVENT_IOC_SET_BPF, prog_fd[0]) < 0);
260         CHECK_PERROR_RET(ioctl(kfd, PERF_EVENT_IOC_ENABLE, 0) < 0);
261
262         len = sizeof(buf);
263         err = bpf_task_fd_query(getpid(), kfd, 0, buf, &len,
264                                 &prog_id, &fd_type, &probe_offset,
265                                 &probe_addr);
266         if (err < 0) {
267                 printf("FAIL: %s, binary_path %s\n", __func__, binary_path);
268                 perror("    :");
269                 return -1;
270         }
271         if ((is_return && fd_type != BPF_FD_TYPE_URETPROBE) ||
272             (!is_return && fd_type != BPF_FD_TYPE_UPROBE)) {
273                 printf("FAIL: %s, incorrect fd_type %u\n", __func__,
274                        fd_type);
275                 return -1;
276         }
277         if (strcmp(binary_path, buf) != 0) {
278                 printf("FAIL: %s, incorrect buf %s\n", __func__, buf);
279                 return -1;
280         }
281         if (probe_offset != offset) {
282                 printf("FAIL: %s, incorrect probe_offset 0x%llx\n", __func__,
283                        probe_offset);
284                 return -1;
285         }
286
287         close(kfd);
288         return 0;
289 }
290
291 int main(int argc, char **argv)
292 {
293         struct rlimit r = {1024*1024, RLIM_INFINITY};
294         extern char __executable_start;
295         char filename[256], buf[256];
296         __u64 uprobe_file_offset;
297
298         snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
299         if (setrlimit(RLIMIT_MEMLOCK, &r)) {
300                 perror("setrlimit(RLIMIT_MEMLOCK)");
301                 return 1;
302         }
303
304         if (load_kallsyms()) {
305                 printf("failed to process /proc/kallsyms\n");
306                 return 1;
307         }
308
309         if (load_bpf_file(filename)) {
310                 printf("%s", bpf_log_buf);
311                 return 1;
312         }
313
314         /* test two functions in the corresponding *_kern.c file */
315         CHECK_AND_RET(test_debug_fs_kprobe(0, "blk_mq_start_request",
316                                            BPF_FD_TYPE_KPROBE));
317         CHECK_AND_RET(test_debug_fs_kprobe(1, "blk_account_io_completion",
318                                            BPF_FD_TYPE_KRETPROBE));
319
320         /* test nondebug fs kprobe */
321         CHECK_AND_RET(test_nondebug_fs_probe("kprobe", "bpf_check", 0x0, 0x0,
322                                              false, BPF_FD_TYPE_KPROBE,
323                                              BPF_FD_TYPE_KRETPROBE,
324                                              buf, sizeof(buf)));
325 #ifdef __x86_64__
326         /* set a kprobe on "bpf_check + 0x5", which is x64 specific */
327         CHECK_AND_RET(test_nondebug_fs_probe("kprobe", "bpf_check", 0x5, 0x0,
328                                              false, BPF_FD_TYPE_KPROBE,
329                                              BPF_FD_TYPE_KRETPROBE,
330                                              buf, sizeof(buf)));
331 #endif
332         CHECK_AND_RET(test_nondebug_fs_probe("kprobe", "bpf_check", 0x0, 0x0,
333                                              true, BPF_FD_TYPE_KPROBE,
334                                              BPF_FD_TYPE_KRETPROBE,
335                                              buf, sizeof(buf)));
336         CHECK_AND_RET(test_nondebug_fs_probe("kprobe", NULL, 0x0,
337                                              ksym_get_addr("bpf_check"), false,
338                                              BPF_FD_TYPE_KPROBE,
339                                              BPF_FD_TYPE_KRETPROBE,
340                                              buf, sizeof(buf)));
341         CHECK_AND_RET(test_nondebug_fs_probe("kprobe", NULL, 0x0,
342                                              ksym_get_addr("bpf_check"), false,
343                                              BPF_FD_TYPE_KPROBE,
344                                              BPF_FD_TYPE_KRETPROBE,
345                                              NULL, 0));
346         CHECK_AND_RET(test_nondebug_fs_probe("kprobe", NULL, 0x0,
347                                              ksym_get_addr("bpf_check"), true,
348                                              BPF_FD_TYPE_KPROBE,
349                                              BPF_FD_TYPE_KRETPROBE,
350                                              buf, sizeof(buf)));
351         CHECK_AND_RET(test_nondebug_fs_probe("kprobe", NULL, 0x0,
352                                              ksym_get_addr("bpf_check"), true,
353                                              BPF_FD_TYPE_KPROBE,
354                                              BPF_FD_TYPE_KRETPROBE,
355                                              0, 0));
356
357         /* test nondebug fs uprobe */
358         /* the calculation of uprobe file offset is based on gcc 7.3.1 on x64
359          * and the default linker script, which defines __executable_start as
360          * the start of the .text section. The calculation could be different
361          * on different systems with different compilers. The right way is
362          * to parse the ELF file. We took a shortcut here.
363          */
364         uprobe_file_offset = (__u64)main - (__u64)&__executable_start;
365         CHECK_AND_RET(test_nondebug_fs_probe("uprobe", (char *)argv[0],
366                                              uprobe_file_offset, 0x0, false,
367                                              BPF_FD_TYPE_UPROBE,
368                                              BPF_FD_TYPE_URETPROBE,
369                                              buf, sizeof(buf)));
370         CHECK_AND_RET(test_nondebug_fs_probe("uprobe", (char *)argv[0],
371                                              uprobe_file_offset, 0x0, true,
372                                              BPF_FD_TYPE_UPROBE,
373                                              BPF_FD_TYPE_URETPROBE,
374                                              buf, sizeof(buf)));
375
376         /* test debug fs uprobe */
377         CHECK_AND_RET(test_debug_fs_uprobe((char *)argv[0], uprobe_file_offset,
378                                            false));
379         CHECK_AND_RET(test_debug_fs_uprobe((char *)argv[0], uprobe_file_offset,
380                                            true));
381
382         return 0;
383 }