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Commit | Line | Data |
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bcea3f96 | 1 | // SPDX-License-Identifier: GPL-2.0 |
413d37d1 | 2 | /* |
77b44d1b | 3 | * Kprobes-based tracing events |
413d37d1 MH |
4 | * |
5 | * Created by Masami Hiramatsu <mhiramat@redhat.com> | |
6 | * | |
413d37d1 | 7 | */ |
72576341 | 8 | #define pr_fmt(fmt) "trace_kprobe: " fmt |
413d37d1 MH |
9 | |
10 | #include <linux/module.h> | |
11 | #include <linux/uaccess.h> | |
b2d09103 | 12 | #include <linux/rculist.h> |
540adea3 | 13 | #include <linux/error-injection.h> |
413d37d1 | 14 | |
d899926f | 15 | #include "trace_kprobe_selftest.h" |
8ab83f56 | 16 | #include "trace_probe.h" |
53305928 | 17 | #include "trace_probe_tmpl.h" |
1ff511e3 | 18 | |
8ab83f56 | 19 | #define KPROBE_EVENT_SYSTEM "kprobes" |
696ced4f | 20 | #define KRETPROBE_MAXACTIVE_MAX 4096 |
e09c8614 | 21 | |
413d37d1 | 22 | /** |
77b44d1b | 23 | * Kprobe event core functions |
413d37d1 | 24 | */ |
c31ffb3f | 25 | struct trace_kprobe { |
413d37d1 | 26 | struct list_head list; |
4a846b44 | 27 | struct kretprobe rp; /* Use rp.kp for kprobe use */ |
a7636d9e | 28 | unsigned long __percpu *nhit; |
413d37d1 | 29 | const char *symbol; /* symbol name */ |
c31ffb3f | 30 | struct trace_probe tp; |
413d37d1 MH |
31 | }; |
32 | ||
c31ffb3f NK |
33 | #define SIZEOF_TRACE_KPROBE(n) \ |
34 | (offsetof(struct trace_kprobe, tp.args) + \ | |
eca0d916 | 35 | (sizeof(struct probe_arg) * (n))) |
a82378d8 | 36 | |
3da0f180 | 37 | static nokprobe_inline bool trace_kprobe_is_return(struct trace_kprobe *tk) |
413d37d1 | 38 | { |
c31ffb3f | 39 | return tk->rp.handler != NULL; |
413d37d1 MH |
40 | } |
41 | ||
3da0f180 | 42 | static nokprobe_inline const char *trace_kprobe_symbol(struct trace_kprobe *tk) |
413d37d1 | 43 | { |
c31ffb3f | 44 | return tk->symbol ? tk->symbol : "unknown"; |
413d37d1 MH |
45 | } |
46 | ||
3da0f180 | 47 | static nokprobe_inline unsigned long trace_kprobe_offset(struct trace_kprobe *tk) |
61424318 | 48 | { |
c31ffb3f | 49 | return tk->rp.kp.offset; |
61424318 MH |
50 | } |
51 | ||
3da0f180 | 52 | static nokprobe_inline bool trace_kprobe_has_gone(struct trace_kprobe *tk) |
61424318 | 53 | { |
c31ffb3f | 54 | return !!(kprobe_gone(&tk->rp.kp)); |
61424318 MH |
55 | } |
56 | ||
3da0f180 | 57 | static nokprobe_inline bool trace_kprobe_within_module(struct trace_kprobe *tk, |
c31ffb3f | 58 | struct module *mod) |
61424318 MH |
59 | { |
60 | int len = strlen(mod->name); | |
c31ffb3f | 61 | const char *name = trace_kprobe_symbol(tk); |
61424318 MH |
62 | return strncmp(mod->name, name, len) == 0 && name[len] == ':'; |
63 | } | |
64 | ||
3da0f180 | 65 | static nokprobe_inline bool trace_kprobe_is_on_module(struct trace_kprobe *tk) |
61424318 | 66 | { |
c31ffb3f | 67 | return !!strchr(trace_kprobe_symbol(tk), ':'); |
61424318 MH |
68 | } |
69 | ||
f18f97ac MN |
70 | static nokprobe_inline unsigned long trace_kprobe_nhit(struct trace_kprobe *tk) |
71 | { | |
72 | unsigned long nhit = 0; | |
73 | int cpu; | |
74 | ||
75 | for_each_possible_cpu(cpu) | |
76 | nhit += *per_cpu_ptr(tk->nhit, cpu); | |
77 | ||
78 | return nhit; | |
79 | } | |
80 | ||
6bc6c77c | 81 | /* Return 0 if it fails to find the symbol address */ |
45408c4f MH |
82 | static nokprobe_inline |
83 | unsigned long trace_kprobe_address(struct trace_kprobe *tk) | |
84 | { | |
85 | unsigned long addr; | |
86 | ||
87 | if (tk->symbol) { | |
88 | addr = (unsigned long) | |
89 | kallsyms_lookup_name(trace_kprobe_symbol(tk)); | |
6bc6c77c MH |
90 | if (addr) |
91 | addr += tk->rp.kp.offset; | |
45408c4f MH |
92 | } else { |
93 | addr = (unsigned long)tk->rp.kp.addr; | |
94 | } | |
95 | return addr; | |
96 | } | |
97 | ||
b4da3340 | 98 | bool trace_kprobe_on_func_entry(struct trace_event_call *call) |
9802d865 JB |
99 | { |
100 | struct trace_kprobe *tk = (struct trace_kprobe *)call->data; | |
b4da3340 MH |
101 | |
102 | return kprobe_on_func_entry(tk->rp.kp.addr, | |
103 | tk->rp.kp.addr ? NULL : tk->rp.kp.symbol_name, | |
104 | tk->rp.kp.addr ? 0 : tk->rp.kp.offset); | |
9802d865 JB |
105 | } |
106 | ||
b4da3340 | 107 | bool trace_kprobe_error_injectable(struct trace_event_call *call) |
9802d865 JB |
108 | { |
109 | struct trace_kprobe *tk = (struct trace_kprobe *)call->data; | |
9802d865 | 110 | |
45408c4f | 111 | return within_error_injection_list(trace_kprobe_address(tk)); |
9802d865 JB |
112 | } |
113 | ||
c31ffb3f NK |
114 | static int register_kprobe_event(struct trace_kprobe *tk); |
115 | static int unregister_kprobe_event(struct trace_kprobe *tk); | |
413d37d1 MH |
116 | |
117 | static DEFINE_MUTEX(probe_lock); | |
118 | static LIST_HEAD(probe_list); | |
119 | ||
50d78056 MH |
120 | static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs); |
121 | static int kretprobe_dispatcher(struct kretprobe_instance *ri, | |
122 | struct pt_regs *regs); | |
123 | ||
4a846b44 MH |
124 | /* |
125 | * Allocate new trace_probe and initialize it (including kprobes). | |
126 | */ | |
c31ffb3f | 127 | static struct trace_kprobe *alloc_trace_kprobe(const char *group, |
f52487e9 | 128 | const char *event, |
4a846b44 MH |
129 | void *addr, |
130 | const char *symbol, | |
131 | unsigned long offs, | |
696ced4f | 132 | int maxactive, |
3a6b7666 | 133 | int nargs, bool is_return) |
413d37d1 | 134 | { |
c31ffb3f | 135 | struct trace_kprobe *tk; |
6f3cf440 | 136 | int ret = -ENOMEM; |
413d37d1 | 137 | |
c31ffb3f NK |
138 | tk = kzalloc(SIZEOF_TRACE_KPROBE(nargs), GFP_KERNEL); |
139 | if (!tk) | |
6f3cf440 | 140 | return ERR_PTR(ret); |
413d37d1 | 141 | |
a7636d9e MKL |
142 | tk->nhit = alloc_percpu(unsigned long); |
143 | if (!tk->nhit) | |
144 | goto error; | |
145 | ||
413d37d1 | 146 | if (symbol) { |
c31ffb3f NK |
147 | tk->symbol = kstrdup(symbol, GFP_KERNEL); |
148 | if (!tk->symbol) | |
413d37d1 | 149 | goto error; |
c31ffb3f NK |
150 | tk->rp.kp.symbol_name = tk->symbol; |
151 | tk->rp.kp.offset = offs; | |
4a846b44 | 152 | } else |
c31ffb3f | 153 | tk->rp.kp.addr = addr; |
4a846b44 MH |
154 | |
155 | if (is_return) | |
c31ffb3f | 156 | tk->rp.handler = kretprobe_dispatcher; |
4a846b44 | 157 | else |
c31ffb3f | 158 | tk->rp.kp.pre_handler = kprobe_dispatcher; |
4a846b44 | 159 | |
696ced4f AC |
160 | tk->rp.maxactive = maxactive; |
161 | ||
da34634f | 162 | if (!event || !is_good_name(event)) { |
6f3cf440 | 163 | ret = -EINVAL; |
4263565d | 164 | goto error; |
6f3cf440 MH |
165 | } |
166 | ||
c31ffb3f NK |
167 | tk->tp.call.class = &tk->tp.class; |
168 | tk->tp.call.name = kstrdup(event, GFP_KERNEL); | |
169 | if (!tk->tp.call.name) | |
4263565d | 170 | goto error; |
413d37d1 | 171 | |
da34634f | 172 | if (!group || !is_good_name(group)) { |
6f3cf440 | 173 | ret = -EINVAL; |
f52487e9 | 174 | goto error; |
6f3cf440 MH |
175 | } |
176 | ||
c31ffb3f NK |
177 | tk->tp.class.system = kstrdup(group, GFP_KERNEL); |
178 | if (!tk->tp.class.system) | |
f52487e9 MH |
179 | goto error; |
180 | ||
c31ffb3f NK |
181 | INIT_LIST_HEAD(&tk->list); |
182 | INIT_LIST_HEAD(&tk->tp.files); | |
183 | return tk; | |
413d37d1 | 184 | error: |
c31ffb3f NK |
185 | kfree(tk->tp.call.name); |
186 | kfree(tk->symbol); | |
a7636d9e | 187 | free_percpu(tk->nhit); |
c31ffb3f | 188 | kfree(tk); |
6f3cf440 | 189 | return ERR_PTR(ret); |
413d37d1 MH |
190 | } |
191 | ||
c31ffb3f | 192 | static void free_trace_kprobe(struct trace_kprobe *tk) |
413d37d1 MH |
193 | { |
194 | int i; | |
195 | ||
c31ffb3f NK |
196 | for (i = 0; i < tk->tp.nr_args; i++) |
197 | traceprobe_free_probe_arg(&tk->tp.args[i]); | |
413d37d1 | 198 | |
c31ffb3f NK |
199 | kfree(tk->tp.call.class->system); |
200 | kfree(tk->tp.call.name); | |
201 | kfree(tk->symbol); | |
a7636d9e | 202 | free_percpu(tk->nhit); |
c31ffb3f | 203 | kfree(tk); |
413d37d1 MH |
204 | } |
205 | ||
c31ffb3f NK |
206 | static struct trace_kprobe *find_trace_kprobe(const char *event, |
207 | const char *group) | |
413d37d1 | 208 | { |
c31ffb3f | 209 | struct trace_kprobe *tk; |
413d37d1 | 210 | |
c31ffb3f | 211 | list_for_each_entry(tk, &probe_list, list) |
687fcc4a | 212 | if (strcmp(trace_event_name(&tk->tp.call), event) == 0 && |
c31ffb3f NK |
213 | strcmp(tk->tp.call.class->system, group) == 0) |
214 | return tk; | |
413d37d1 MH |
215 | return NULL; |
216 | } | |
217 | ||
87107a25 SRV |
218 | static inline int __enable_trace_kprobe(struct trace_kprobe *tk) |
219 | { | |
220 | int ret = 0; | |
221 | ||
222 | if (trace_probe_is_registered(&tk->tp) && !trace_kprobe_has_gone(tk)) { | |
223 | if (trace_kprobe_is_return(tk)) | |
224 | ret = enable_kretprobe(&tk->rp); | |
225 | else | |
226 | ret = enable_kprobe(&tk->rp.kp); | |
227 | } | |
228 | ||
229 | return ret; | |
230 | } | |
231 | ||
41a7dd42 MH |
232 | /* |
233 | * Enable trace_probe | |
234 | * if the file is NULL, enable "perf" handler, or enable "trace" handler. | |
235 | */ | |
236 | static int | |
7f1d2f82 | 237 | enable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file) |
1538f888 | 238 | { |
87107a25 | 239 | struct event_file_link *link; |
1538f888 MH |
240 | int ret = 0; |
241 | ||
41a7dd42 | 242 | if (file) { |
b04d52e3 ON |
243 | link = kmalloc(sizeof(*link), GFP_KERNEL); |
244 | if (!link) { | |
41a7dd42 | 245 | ret = -ENOMEM; |
3fe3d619 | 246 | goto out; |
41a7dd42 | 247 | } |
41a7dd42 | 248 | |
b04d52e3 | 249 | link->file = file; |
c31ffb3f | 250 | list_add_tail_rcu(&link->list, &tk->tp.files); |
41a7dd42 | 251 | |
c31ffb3f | 252 | tk->tp.flags |= TP_FLAG_TRACE; |
87107a25 SRV |
253 | ret = __enable_trace_kprobe(tk); |
254 | if (ret) { | |
255 | list_del_rcu(&link->list); | |
57ea2a34 AS |
256 | kfree(link); |
257 | tk->tp.flags &= ~TP_FLAG_TRACE; | |
57ea2a34 | 258 | } |
87107a25 SRV |
259 | |
260 | } else { | |
261 | tk->tp.flags |= TP_FLAG_PROFILE; | |
262 | ret = __enable_trace_kprobe(tk); | |
263 | if (ret) | |
264 | tk->tp.flags &= ~TP_FLAG_PROFILE; | |
57ea2a34 | 265 | } |
3fe3d619 | 266 | out: |
1538f888 MH |
267 | return ret; |
268 | } | |
269 | ||
41a7dd42 MH |
270 | /* |
271 | * Disable trace_probe | |
272 | * if the file is NULL, disable "perf" handler, or disable "trace" handler. | |
273 | */ | |
274 | static int | |
7f1d2f82 | 275 | disable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file) |
1538f888 | 276 | { |
a232e270 MH |
277 | struct event_file_link *link = NULL; |
278 | int wait = 0; | |
41a7dd42 MH |
279 | int ret = 0; |
280 | ||
41a7dd42 | 281 | if (file) { |
c31ffb3f | 282 | link = find_event_file_link(&tk->tp, file); |
b04d52e3 | 283 | if (!link) { |
41a7dd42 | 284 | ret = -EINVAL; |
3fe3d619 | 285 | goto out; |
41a7dd42 MH |
286 | } |
287 | ||
b04d52e3 | 288 | list_del_rcu(&link->list); |
a232e270 | 289 | wait = 1; |
c31ffb3f | 290 | if (!list_empty(&tk->tp.files)) |
b04d52e3 | 291 | goto out; |
41a7dd42 | 292 | |
c31ffb3f | 293 | tk->tp.flags &= ~TP_FLAG_TRACE; |
41a7dd42 | 294 | } else |
c31ffb3f | 295 | tk->tp.flags &= ~TP_FLAG_PROFILE; |
41a7dd42 | 296 | |
c31ffb3f NK |
297 | if (!trace_probe_is_enabled(&tk->tp) && trace_probe_is_registered(&tk->tp)) { |
298 | if (trace_kprobe_is_return(tk)) | |
299 | disable_kretprobe(&tk->rp); | |
1538f888 | 300 | else |
c31ffb3f | 301 | disable_kprobe(&tk->rp.kp); |
a232e270 | 302 | wait = 1; |
1538f888 | 303 | } |
e12f03d7 SL |
304 | |
305 | /* | |
306 | * if tk is not added to any list, it must be a local trace_kprobe | |
307 | * created with perf_event_open. We don't need to wait for these | |
308 | * trace_kprobes | |
309 | */ | |
310 | if (list_empty(&tk->list)) | |
311 | wait = 0; | |
3fe3d619 | 312 | out: |
a232e270 MH |
313 | if (wait) { |
314 | /* | |
315 | * Synchronize with kprobe_trace_func/kretprobe_trace_func | |
316 | * to ensure disabled (all running handlers are finished). | |
317 | * This is not only for kfree(), but also the caller, | |
318 | * trace_remove_event_call() supposes it for releasing | |
319 | * event_call related objects, which will be accessed in | |
320 | * the kprobe_trace_func/kretprobe_trace_func. | |
321 | */ | |
322 | synchronize_sched(); | |
323 | kfree(link); /* Ignored if link == NULL */ | |
324 | } | |
325 | ||
41a7dd42 | 326 | return ret; |
1538f888 MH |
327 | } |
328 | ||
45408c4f MH |
329 | #if defined(CONFIG_KPROBES_ON_FTRACE) && \ |
330 | !defined(CONFIG_KPROBE_EVENTS_ON_NOTRACE) | |
331 | static bool within_notrace_func(struct trace_kprobe *tk) | |
332 | { | |
333 | unsigned long offset, size, addr; | |
334 | ||
335 | addr = trace_kprobe_address(tk); | |
6bc6c77c MH |
336 | if (!addr || !kallsyms_lookup_size_offset(addr, &size, &offset)) |
337 | return false; | |
45408c4f | 338 | |
9161a864 MH |
339 | /* Get the entry address of the target function */ |
340 | addr -= offset; | |
341 | ||
342 | /* | |
343 | * Since ftrace_location_range() does inclusive range check, we need | |
344 | * to subtract 1 byte from the end address. | |
345 | */ | |
346 | return !ftrace_location_range(addr, addr + size - 1); | |
45408c4f MH |
347 | } |
348 | #else | |
349 | #define within_notrace_func(tk) (false) | |
350 | #endif | |
351 | ||
61424318 | 352 | /* Internal register function - just handle k*probes and flags */ |
c31ffb3f | 353 | static int __register_trace_kprobe(struct trace_kprobe *tk) |
413d37d1 | 354 | { |
53305928 | 355 | int ret; |
61424318 | 356 | |
c31ffb3f | 357 | if (trace_probe_is_registered(&tk->tp)) |
61424318 MH |
358 | return -EINVAL; |
359 | ||
45408c4f MH |
360 | if (within_notrace_func(tk)) { |
361 | pr_warn("Could not probe notrace function %s\n", | |
362 | trace_kprobe_symbol(tk)); | |
363 | return -EINVAL; | |
364 | } | |
365 | ||
61424318 | 366 | /* Set/clear disabled flag according to tp->flag */ |
c31ffb3f NK |
367 | if (trace_probe_is_enabled(&tk->tp)) |
368 | tk->rp.kp.flags &= ~KPROBE_FLAG_DISABLED; | |
61424318 | 369 | else |
c31ffb3f | 370 | tk->rp.kp.flags |= KPROBE_FLAG_DISABLED; |
61424318 | 371 | |
c31ffb3f NK |
372 | if (trace_kprobe_is_return(tk)) |
373 | ret = register_kretprobe(&tk->rp); | |
413d37d1 | 374 | else |
c31ffb3f | 375 | ret = register_kprobe(&tk->rp.kp); |
61424318 MH |
376 | |
377 | if (ret == 0) | |
c31ffb3f | 378 | tk->tp.flags |= TP_FLAG_REGISTERED; |
61424318 | 379 | else { |
c31ffb3f | 380 | if (ret == -ENOENT && trace_kprobe_is_on_module(tk)) { |
a395d6a7 | 381 | pr_warn("This probe might be able to register after target module is loaded. Continue.\n"); |
61424318 MH |
382 | ret = 0; |
383 | } else if (ret == -EILSEQ) { | |
a395d6a7 JP |
384 | pr_warn("Probing address(0x%p) is not an instruction boundary.\n", |
385 | tk->rp.kp.addr); | |
61424318 MH |
386 | ret = -EINVAL; |
387 | } | |
388 | } | |
389 | ||
390 | return ret; | |
391 | } | |
392 | ||
393 | /* Internal unregister function - just handle k*probes and flags */ | |
c31ffb3f | 394 | static void __unregister_trace_kprobe(struct trace_kprobe *tk) |
61424318 | 395 | { |
c31ffb3f NK |
396 | if (trace_probe_is_registered(&tk->tp)) { |
397 | if (trace_kprobe_is_return(tk)) | |
398 | unregister_kretprobe(&tk->rp); | |
61424318 | 399 | else |
c31ffb3f NK |
400 | unregister_kprobe(&tk->rp.kp); |
401 | tk->tp.flags &= ~TP_FLAG_REGISTERED; | |
61424318 | 402 | /* Cleanup kprobe for reuse */ |
c31ffb3f NK |
403 | if (tk->rp.kp.symbol_name) |
404 | tk->rp.kp.addr = NULL; | |
61424318 MH |
405 | } |
406 | } | |
407 | ||
408 | /* Unregister a trace_probe and probe_event: call with locking probe_lock */ | |
c31ffb3f | 409 | static int unregister_trace_kprobe(struct trace_kprobe *tk) |
61424318 | 410 | { |
02ca1521 | 411 | /* Enabled event can not be unregistered */ |
c31ffb3f | 412 | if (trace_probe_is_enabled(&tk->tp)) |
02ca1521 MH |
413 | return -EBUSY; |
414 | ||
40c32592 | 415 | /* Will fail if probe is being used by ftrace or perf */ |
c31ffb3f | 416 | if (unregister_kprobe_event(tk)) |
40c32592 SRRH |
417 | return -EBUSY; |
418 | ||
c31ffb3f NK |
419 | __unregister_trace_kprobe(tk); |
420 | list_del(&tk->list); | |
02ca1521 MH |
421 | |
422 | return 0; | |
413d37d1 MH |
423 | } |
424 | ||
425 | /* Register a trace_probe and probe_event */ | |
c31ffb3f | 426 | static int register_trace_kprobe(struct trace_kprobe *tk) |
413d37d1 | 427 | { |
c31ffb3f | 428 | struct trace_kprobe *old_tk; |
413d37d1 MH |
429 | int ret; |
430 | ||
431 | mutex_lock(&probe_lock); | |
432 | ||
61424318 | 433 | /* Delete old (same name) event if exist */ |
687fcc4a | 434 | old_tk = find_trace_kprobe(trace_event_name(&tk->tp.call), |
de7b2973 | 435 | tk->tp.call.class->system); |
c31ffb3f NK |
436 | if (old_tk) { |
437 | ret = unregister_trace_kprobe(old_tk); | |
02ca1521 MH |
438 | if (ret < 0) |
439 | goto end; | |
c31ffb3f | 440 | free_trace_kprobe(old_tk); |
2d5e067e | 441 | } |
61424318 MH |
442 | |
443 | /* Register new event */ | |
c31ffb3f | 444 | ret = register_kprobe_event(tk); |
2d5e067e | 445 | if (ret) { |
a395d6a7 | 446 | pr_warn("Failed to register probe event(%d)\n", ret); |
2d5e067e MH |
447 | goto end; |
448 | } | |
449 | ||
61424318 | 450 | /* Register k*probe */ |
c31ffb3f | 451 | ret = __register_trace_kprobe(tk); |
61424318 | 452 | if (ret < 0) |
c31ffb3f | 453 | unregister_kprobe_event(tk); |
61424318 | 454 | else |
c31ffb3f | 455 | list_add_tail(&tk->list, &probe_list); |
61424318 | 456 | |
413d37d1 MH |
457 | end: |
458 | mutex_unlock(&probe_lock); | |
459 | return ret; | |
460 | } | |
461 | ||
61424318 | 462 | /* Module notifier call back, checking event on the module */ |
c31ffb3f | 463 | static int trace_kprobe_module_callback(struct notifier_block *nb, |
61424318 MH |
464 | unsigned long val, void *data) |
465 | { | |
466 | struct module *mod = data; | |
c31ffb3f | 467 | struct trace_kprobe *tk; |
61424318 MH |
468 | int ret; |
469 | ||
470 | if (val != MODULE_STATE_COMING) | |
471 | return NOTIFY_DONE; | |
472 | ||
473 | /* Update probes on coming module */ | |
474 | mutex_lock(&probe_lock); | |
c31ffb3f NK |
475 | list_for_each_entry(tk, &probe_list, list) { |
476 | if (trace_kprobe_within_module(tk, mod)) { | |
02ca1521 | 477 | /* Don't need to check busy - this should have gone. */ |
c31ffb3f NK |
478 | __unregister_trace_kprobe(tk); |
479 | ret = __register_trace_kprobe(tk); | |
61424318 | 480 | if (ret) |
a395d6a7 JP |
481 | pr_warn("Failed to re-register probe %s on %s: %d\n", |
482 | trace_event_name(&tk->tp.call), | |
483 | mod->name, ret); | |
61424318 MH |
484 | } |
485 | } | |
486 | mutex_unlock(&probe_lock); | |
487 | ||
488 | return NOTIFY_DONE; | |
489 | } | |
490 | ||
c31ffb3f NK |
491 | static struct notifier_block trace_kprobe_module_nb = { |
492 | .notifier_call = trace_kprobe_module_callback, | |
61424318 MH |
493 | .priority = 1 /* Invoked after kprobe module callback */ |
494 | }; | |
495 | ||
fca18a47 NR |
496 | /* Convert certain expected symbols into '_' when generating event names */ |
497 | static inline void sanitize_event_name(char *name) | |
498 | { | |
499 | while (*name++ != '\0') | |
500 | if (*name == ':' || *name == '.') | |
501 | *name = '_'; | |
502 | } | |
503 | ||
c31ffb3f | 504 | static int create_trace_kprobe(int argc, char **argv) |
413d37d1 MH |
505 | { |
506 | /* | |
507 | * Argument syntax: | |
696ced4f AC |
508 | * - Add kprobe: |
509 | * p[:[GRP/]EVENT] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS] | |
510 | * - Add kretprobe: | |
511 | * r[MAXACTIVE][:[GRP/]EVENT] [MOD:]KSYM[+0] [FETCHARGS] | |
413d37d1 | 512 | * Fetch args: |
2e06ff63 MH |
513 | * $retval : fetch return value |
514 | * $stack : fetch stack address | |
515 | * $stackN : fetch Nth of stack (N:0-) | |
35abb67d | 516 | * $comm : fetch current task comm |
413d37d1 MH |
517 | * @ADDR : fetch memory at ADDR (ADDR should be in kernel) |
518 | * @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol) | |
519 | * %REG : fetch register REG | |
93ccae7a | 520 | * Dereferencing memory fetch: |
413d37d1 | 521 | * +|-offs(ARG) : fetch memory at ARG +|- offs address. |
eca0d916 MH |
522 | * Alias name of args: |
523 | * NAME=FETCHARG : set NAME as alias of FETCHARG. | |
93ccae7a MH |
524 | * Type of args: |
525 | * FETCHARG:TYPE : use TYPE instead of unsigned long. | |
413d37d1 | 526 | */ |
c31ffb3f | 527 | struct trace_kprobe *tk; |
413d37d1 | 528 | int i, ret = 0; |
3a6b7666 | 529 | bool is_return = false, is_delete = false; |
93ccae7a | 530 | char *symbol = NULL, *event = NULL, *group = NULL; |
696ced4f | 531 | int maxactive = 0; |
da34634f | 532 | char *arg; |
c5d343b6 | 533 | long offset = 0; |
413d37d1 | 534 | void *addr = NULL; |
4a846b44 | 535 | char buf[MAX_EVENT_NAME_LEN]; |
413d37d1 | 536 | |
a7c312be | 537 | /* argc must be >= 1 */ |
413d37d1 | 538 | if (argv[0][0] == 'p') |
3a6b7666 | 539 | is_return = false; |
413d37d1 | 540 | else if (argv[0][0] == 'r') |
3a6b7666 | 541 | is_return = true; |
a7c312be | 542 | else if (argv[0][0] == '-') |
3a6b7666 | 543 | is_delete = true; |
e63cc239 | 544 | else { |
a7c312be MH |
545 | pr_info("Probe definition must be started with 'p', 'r' or" |
546 | " '-'.\n"); | |
413d37d1 | 547 | return -EINVAL; |
e63cc239 | 548 | } |
413d37d1 | 549 | |
696ced4f AC |
550 | event = strchr(&argv[0][1], ':'); |
551 | if (event) { | |
552 | event[0] = '\0'; | |
553 | event++; | |
554 | } | |
555 | if (is_return && isdigit(argv[0][1])) { | |
556 | ret = kstrtouint(&argv[0][1], 0, &maxactive); | |
557 | if (ret) { | |
558 | pr_info("Failed to parse maxactive.\n"); | |
559 | return ret; | |
560 | } | |
561 | /* kretprobes instances are iterated over via a list. The | |
562 | * maximum should stay reasonable. | |
563 | */ | |
564 | if (maxactive > KRETPROBE_MAXACTIVE_MAX) { | |
565 | pr_info("Maxactive is too big (%d > %d).\n", | |
566 | maxactive, KRETPROBE_MAXACTIVE_MAX); | |
567 | return -E2BIG; | |
568 | } | |
569 | } | |
570 | ||
571 | if (event) { | |
d6b183ed SRV |
572 | char *slash; |
573 | ||
574 | slash = strchr(event, '/'); | |
575 | if (slash) { | |
f52487e9 | 576 | group = event; |
d6b183ed SRV |
577 | event = slash + 1; |
578 | slash[0] = '\0'; | |
f52487e9 | 579 | if (strlen(group) == 0) { |
a5efd925 | 580 | pr_info("Group name is not specified\n"); |
f52487e9 MH |
581 | return -EINVAL; |
582 | } | |
583 | } | |
413d37d1 | 584 | if (strlen(event) == 0) { |
a5efd925 | 585 | pr_info("Event name is not specified\n"); |
413d37d1 MH |
586 | return -EINVAL; |
587 | } | |
588 | } | |
a7c312be MH |
589 | if (!group) |
590 | group = KPROBE_EVENT_SYSTEM; | |
413d37d1 | 591 | |
a7c312be MH |
592 | if (is_delete) { |
593 | if (!event) { | |
594 | pr_info("Delete command needs an event name.\n"); | |
595 | return -EINVAL; | |
596 | } | |
9da79ab8 | 597 | mutex_lock(&probe_lock); |
c31ffb3f NK |
598 | tk = find_trace_kprobe(event, group); |
599 | if (!tk) { | |
9da79ab8 | 600 | mutex_unlock(&probe_lock); |
a7c312be MH |
601 | pr_info("Event %s/%s doesn't exist.\n", group, event); |
602 | return -ENOENT; | |
603 | } | |
604 | /* delete an event */ | |
c31ffb3f | 605 | ret = unregister_trace_kprobe(tk); |
02ca1521 | 606 | if (ret == 0) |
c31ffb3f | 607 | free_trace_kprobe(tk); |
9da79ab8 | 608 | mutex_unlock(&probe_lock); |
02ca1521 | 609 | return ret; |
a7c312be MH |
610 | } |
611 | ||
612 | if (argc < 2) { | |
613 | pr_info("Probe point is not specified.\n"); | |
614 | return -EINVAL; | |
615 | } | |
9e52b325 SD |
616 | |
617 | /* try to parse an address. if that fails, try to read the | |
618 | * input as a symbol. */ | |
619 | if (kstrtoul(argv[1], 0, (unsigned long *)&addr)) { | |
413d37d1 MH |
620 | /* a symbol specified */ |
621 | symbol = argv[1]; | |
622 | /* TODO: support .init module functions */ | |
8ab83f56 | 623 | ret = traceprobe_split_symbol_offset(symbol, &offset); |
c5d343b6 | 624 | if (ret || offset < 0 || offset > UINT_MAX) { |
9e52b325 | 625 | pr_info("Failed to parse either an address or a symbol.\n"); |
413d37d1 | 626 | return ret; |
e63cc239 | 627 | } |
d0e02579 | 628 | if (offset && is_return && |
659b957f | 629 | !kprobe_on_func_entry(NULL, symbol, offset)) { |
d0e02579 | 630 | pr_info("Given offset is not valid for return probe.\n"); |
413d37d1 | 631 | return -EINVAL; |
e63cc239 | 632 | } |
413d37d1 | 633 | } |
a82378d8 | 634 | argc -= 2; argv += 2; |
413d37d1 MH |
635 | |
636 | /* setup a probe */ | |
4263565d MH |
637 | if (!event) { |
638 | /* Make a new event name */ | |
4263565d | 639 | if (symbol) |
6f3cf440 | 640 | snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld", |
4263565d MH |
641 | is_return ? 'r' : 'p', symbol, offset); |
642 | else | |
6f3cf440 | 643 | snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p", |
4263565d | 644 | is_return ? 'r' : 'p', addr); |
fca18a47 | 645 | sanitize_event_name(buf); |
4a846b44 MH |
646 | event = buf; |
647 | } | |
696ced4f AC |
648 | tk = alloc_trace_kprobe(group, event, addr, symbol, offset, maxactive, |
649 | argc, is_return); | |
c31ffb3f | 650 | if (IS_ERR(tk)) { |
e63cc239 | 651 | pr_info("Failed to allocate trace_probe.(%d)\n", |
c31ffb3f NK |
652 | (int)PTR_ERR(tk)); |
653 | return PTR_ERR(tk); | |
e63cc239 | 654 | } |
413d37d1 | 655 | |
413d37d1 | 656 | /* parse arguments */ |
a82378d8 MH |
657 | ret = 0; |
658 | for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) { | |
c31ffb3f NK |
659 | struct probe_arg *parg = &tk->tp.args[i]; |
660 | ||
61a52736 | 661 | /* Increment count for freeing args in error case */ |
c31ffb3f | 662 | tk->tp.nr_args++; |
61a52736 | 663 | |
eca0d916 MH |
664 | /* Parse argument name */ |
665 | arg = strchr(argv[i], '='); | |
aba91595 | 666 | if (arg) { |
eca0d916 | 667 | *arg++ = '\0'; |
c31ffb3f | 668 | parg->name = kstrdup(argv[i], GFP_KERNEL); |
aba91595 | 669 | } else { |
eca0d916 | 670 | arg = argv[i]; |
aba91595 MH |
671 | /* If argument name is omitted, set "argN" */ |
672 | snprintf(buf, MAX_EVENT_NAME_LEN, "arg%d", i + 1); | |
c31ffb3f | 673 | parg->name = kstrdup(buf, GFP_KERNEL); |
aba91595 | 674 | } |
a703d946 | 675 | |
c31ffb3f | 676 | if (!parg->name) { |
aba91595 | 677 | pr_info("Failed to allocate argument[%d] name.\n", i); |
ba8665d7 | 678 | ret = -ENOMEM; |
413d37d1 MH |
679 | goto error; |
680 | } | |
da34634f | 681 | |
c31ffb3f | 682 | if (!is_good_name(parg->name)) { |
da34634f | 683 | pr_info("Invalid argument[%d] name: %s\n", |
c31ffb3f | 684 | i, parg->name); |
da34634f MH |
685 | ret = -EINVAL; |
686 | goto error; | |
687 | } | |
93ccae7a | 688 | |
c31ffb3f NK |
689 | if (traceprobe_conflict_field_name(parg->name, |
690 | tk->tp.args, i)) { | |
aba91595 | 691 | pr_info("Argument[%d] name '%s' conflicts with " |
93ccae7a MH |
692 | "another field.\n", i, argv[i]); |
693 | ret = -EINVAL; | |
694 | goto error; | |
695 | } | |
ba8665d7 MH |
696 | |
697 | /* Parse fetch argument */ | |
c31ffb3f | 698 | ret = traceprobe_parse_probe_arg(arg, &tk->tp.size, parg, |
f451bc89 | 699 | is_return, true); |
e63cc239 | 700 | if (ret) { |
aba91595 | 701 | pr_info("Parse error at argument[%d]. (%d)\n", i, ret); |
413d37d1 | 702 | goto error; |
e63cc239 | 703 | } |
413d37d1 | 704 | } |
413d37d1 | 705 | |
c31ffb3f | 706 | ret = register_trace_kprobe(tk); |
413d37d1 MH |
707 | if (ret) |
708 | goto error; | |
709 | return 0; | |
710 | ||
711 | error: | |
c31ffb3f | 712 | free_trace_kprobe(tk); |
413d37d1 MH |
713 | return ret; |
714 | } | |
715 | ||
c31ffb3f | 716 | static int release_all_trace_kprobes(void) |
413d37d1 | 717 | { |
c31ffb3f | 718 | struct trace_kprobe *tk; |
02ca1521 | 719 | int ret = 0; |
413d37d1 MH |
720 | |
721 | mutex_lock(&probe_lock); | |
02ca1521 | 722 | /* Ensure no probe is in use. */ |
c31ffb3f NK |
723 | list_for_each_entry(tk, &probe_list, list) |
724 | if (trace_probe_is_enabled(&tk->tp)) { | |
02ca1521 MH |
725 | ret = -EBUSY; |
726 | goto end; | |
727 | } | |
413d37d1 MH |
728 | /* TODO: Use batch unregistration */ |
729 | while (!list_empty(&probe_list)) { | |
c31ffb3f NK |
730 | tk = list_entry(probe_list.next, struct trace_kprobe, list); |
731 | ret = unregister_trace_kprobe(tk); | |
40c32592 SRRH |
732 | if (ret) |
733 | goto end; | |
c31ffb3f | 734 | free_trace_kprobe(tk); |
413d37d1 | 735 | } |
02ca1521 MH |
736 | |
737 | end: | |
413d37d1 | 738 | mutex_unlock(&probe_lock); |
02ca1521 MH |
739 | |
740 | return ret; | |
413d37d1 MH |
741 | } |
742 | ||
413d37d1 MH |
743 | /* Probes listing interfaces */ |
744 | static void *probes_seq_start(struct seq_file *m, loff_t *pos) | |
745 | { | |
746 | mutex_lock(&probe_lock); | |
747 | return seq_list_start(&probe_list, *pos); | |
748 | } | |
749 | ||
750 | static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos) | |
751 | { | |
752 | return seq_list_next(v, &probe_list, pos); | |
753 | } | |
754 | ||
755 | static void probes_seq_stop(struct seq_file *m, void *v) | |
756 | { | |
757 | mutex_unlock(&probe_lock); | |
758 | } | |
759 | ||
760 | static int probes_seq_show(struct seq_file *m, void *v) | |
761 | { | |
c31ffb3f | 762 | struct trace_kprobe *tk = v; |
93ccae7a | 763 | int i; |
413d37d1 | 764 | |
fa6f0cc7 | 765 | seq_putc(m, trace_kprobe_is_return(tk) ? 'r' : 'p'); |
de7b2973 | 766 | seq_printf(m, ":%s/%s", tk->tp.call.class->system, |
687fcc4a | 767 | trace_event_name(&tk->tp.call)); |
413d37d1 | 768 | |
c31ffb3f NK |
769 | if (!tk->symbol) |
770 | seq_printf(m, " 0x%p", tk->rp.kp.addr); | |
771 | else if (tk->rp.kp.offset) | |
772 | seq_printf(m, " %s+%u", trace_kprobe_symbol(tk), | |
773 | tk->rp.kp.offset); | |
413d37d1 | 774 | else |
c31ffb3f | 775 | seq_printf(m, " %s", trace_kprobe_symbol(tk)); |
413d37d1 | 776 | |
c31ffb3f NK |
777 | for (i = 0; i < tk->tp.nr_args; i++) |
778 | seq_printf(m, " %s=%s", tk->tp.args[i].name, tk->tp.args[i].comm); | |
fa6f0cc7 | 779 | seq_putc(m, '\n'); |
93ccae7a | 780 | |
413d37d1 MH |
781 | return 0; |
782 | } | |
783 | ||
784 | static const struct seq_operations probes_seq_op = { | |
785 | .start = probes_seq_start, | |
786 | .next = probes_seq_next, | |
787 | .stop = probes_seq_stop, | |
788 | .show = probes_seq_show | |
789 | }; | |
790 | ||
791 | static int probes_open(struct inode *inode, struct file *file) | |
792 | { | |
02ca1521 MH |
793 | int ret; |
794 | ||
795 | if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { | |
c31ffb3f | 796 | ret = release_all_trace_kprobes(); |
02ca1521 MH |
797 | if (ret < 0) |
798 | return ret; | |
799 | } | |
413d37d1 MH |
800 | |
801 | return seq_open(file, &probes_seq_op); | |
802 | } | |
803 | ||
413d37d1 MH |
804 | static ssize_t probes_write(struct file *file, const char __user *buffer, |
805 | size_t count, loff_t *ppos) | |
806 | { | |
7e465baa TZ |
807 | return trace_parse_run_command(file, buffer, count, ppos, |
808 | create_trace_kprobe); | |
413d37d1 MH |
809 | } |
810 | ||
811 | static const struct file_operations kprobe_events_ops = { | |
812 | .owner = THIS_MODULE, | |
813 | .open = probes_open, | |
814 | .read = seq_read, | |
815 | .llseek = seq_lseek, | |
816 | .release = seq_release, | |
817 | .write = probes_write, | |
818 | }; | |
819 | ||
cd7e7bd5 MH |
820 | /* Probes profiling interfaces */ |
821 | static int probes_profile_seq_show(struct seq_file *m, void *v) | |
822 | { | |
c31ffb3f | 823 | struct trace_kprobe *tk = v; |
cd7e7bd5 | 824 | |
de7b2973 | 825 | seq_printf(m, " %-44s %15lu %15lu\n", |
f18f97ac MN |
826 | trace_event_name(&tk->tp.call), |
827 | trace_kprobe_nhit(tk), | |
c31ffb3f | 828 | tk->rp.kp.nmissed); |
cd7e7bd5 MH |
829 | |
830 | return 0; | |
831 | } | |
832 | ||
833 | static const struct seq_operations profile_seq_op = { | |
834 | .start = probes_seq_start, | |
835 | .next = probes_seq_next, | |
836 | .stop = probes_seq_stop, | |
837 | .show = probes_profile_seq_show | |
838 | }; | |
839 | ||
840 | static int profile_open(struct inode *inode, struct file *file) | |
841 | { | |
842 | return seq_open(file, &profile_seq_op); | |
843 | } | |
844 | ||
845 | static const struct file_operations kprobe_profile_ops = { | |
846 | .owner = THIS_MODULE, | |
847 | .open = profile_open, | |
848 | .read = seq_read, | |
849 | .llseek = seq_lseek, | |
850 | .release = seq_release, | |
851 | }; | |
852 | ||
53305928 MH |
853 | /* Kprobe specific fetch functions */ |
854 | ||
855 | /* Return the length of string -- including null terminal byte */ | |
9178412d MH |
856 | static nokprobe_inline int |
857 | fetch_store_strlen(unsigned long addr) | |
53305928 MH |
858 | { |
859 | mm_segment_t old_fs; | |
860 | int ret, len = 0; | |
861 | u8 c; | |
862 | ||
863 | old_fs = get_fs(); | |
864 | set_fs(KERNEL_DS); | |
865 | pagefault_disable(); | |
866 | ||
867 | do { | |
868 | ret = __copy_from_user_inatomic(&c, (u8 *)addr + len, 1); | |
869 | len++; | |
870 | } while (c && ret == 0 && len < MAX_STRING_SIZE); | |
871 | ||
872 | pagefault_enable(); | |
873 | set_fs(old_fs); | |
874 | ||
9178412d | 875 | return (ret < 0) ? ret : len; |
53305928 MH |
876 | } |
877 | ||
878 | /* | |
879 | * Fetch a null-terminated string. Caller MUST set *(u32 *)buf with max | |
880 | * length and relative data location. | |
881 | */ | |
9178412d MH |
882 | static nokprobe_inline int |
883 | fetch_store_string(unsigned long addr, void *dest, void *base) | |
53305928 | 884 | { |
9178412d MH |
885 | int maxlen = get_loc_len(*(u32 *)dest); |
886 | u8 *dst = get_loc_data(dest, base); | |
53305928 MH |
887 | long ret; |
888 | ||
9178412d MH |
889 | if (unlikely(!maxlen)) |
890 | return -ENOMEM; | |
53305928 MH |
891 | /* |
892 | * Try to get string again, since the string can be changed while | |
893 | * probing. | |
894 | */ | |
895 | ret = strncpy_from_unsafe(dst, (void *)addr, maxlen); | |
896 | ||
9178412d MH |
897 | if (ret >= 0) |
898 | *(u32 *)dest = make_data_loc(ret, (void *)dst - base); | |
899 | return ret; | |
53305928 MH |
900 | } |
901 | ||
9b960a38 MH |
902 | static nokprobe_inline int |
903 | probe_mem_read(void *dest, void *src, size_t size) | |
904 | { | |
905 | return probe_kernel_read(dest, src, size); | |
906 | } | |
907 | ||
53305928 MH |
908 | /* Note that we don't verify it, since the code does not come from user space */ |
909 | static int | |
910 | process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest, | |
9178412d | 911 | void *base) |
53305928 MH |
912 | { |
913 | unsigned long val; | |
53305928 MH |
914 | |
915 | /* 1st stage: get value from context */ | |
916 | switch (code->op) { | |
917 | case FETCH_OP_REG: | |
918 | val = regs_get_register(regs, code->param); | |
919 | break; | |
920 | case FETCH_OP_STACK: | |
921 | val = regs_get_kernel_stack_nth(regs, code->param); | |
922 | break; | |
923 | case FETCH_OP_STACKP: | |
924 | val = kernel_stack_pointer(regs); | |
925 | break; | |
926 | case FETCH_OP_RETVAL: | |
927 | val = regs_return_value(regs); | |
928 | break; | |
929 | case FETCH_OP_IMM: | |
930 | val = code->immediate; | |
931 | break; | |
932 | case FETCH_OP_COMM: | |
933 | val = (unsigned long)current->comm; | |
934 | break; | |
935 | default: | |
936 | return -EILSEQ; | |
937 | } | |
938 | code++; | |
939 | ||
9b960a38 | 940 | return process_fetch_insn_bottom(code, val, dest, base); |
53305928 MH |
941 | } |
942 | NOKPROBE_SYMBOL(process_fetch_insn) | |
943 | ||
413d37d1 | 944 | /* Kprobe handler */ |
3da0f180 | 945 | static nokprobe_inline void |
c31ffb3f | 946 | __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs, |
7f1d2f82 | 947 | struct trace_event_file *trace_file) |
413d37d1 | 948 | { |
93ccae7a | 949 | struct kprobe_trace_entry_head *entry; |
413d37d1 | 950 | struct ring_buffer_event *event; |
8f8ffe24 | 951 | struct ring_buffer *buffer; |
e09c8614 | 952 | int size, dsize, pc; |
413d37d1 | 953 | unsigned long irq_flags; |
2425bcb9 | 954 | struct trace_event_call *call = &tk->tp.call; |
413d37d1 | 955 | |
7f1d2f82 | 956 | WARN_ON(call != trace_file->event_call); |
41a7dd42 | 957 | |
09a5059a | 958 | if (trace_trigger_soft_disabled(trace_file)) |
13a1e4ae | 959 | return; |
b8820084 | 960 | |
413d37d1 MH |
961 | local_save_flags(irq_flags); |
962 | pc = preempt_count(); | |
963 | ||
c31ffb3f NK |
964 | dsize = __get_data_size(&tk->tp, regs); |
965 | size = sizeof(*entry) + tk->tp.size + dsize; | |
413d37d1 | 966 | |
7f1d2f82 | 967 | event = trace_event_buffer_lock_reserve(&buffer, trace_file, |
41a7dd42 MH |
968 | call->event.type, |
969 | size, irq_flags, pc); | |
413d37d1 | 970 | if (!event) |
1e12a4a7 | 971 | return; |
413d37d1 MH |
972 | |
973 | entry = ring_buffer_event_data(event); | |
c31ffb3f | 974 | entry->ip = (unsigned long)tk->rp.kp.addr; |
9178412d | 975 | store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize); |
413d37d1 | 976 | |
7f1d2f82 | 977 | event_trigger_unlock_commit_regs(trace_file, buffer, event, |
13a1e4ae | 978 | entry, irq_flags, pc, regs); |
413d37d1 MH |
979 | } |
980 | ||
3da0f180 | 981 | static void |
c31ffb3f | 982 | kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs) |
41a7dd42 | 983 | { |
b04d52e3 | 984 | struct event_file_link *link; |
41a7dd42 | 985 | |
c31ffb3f NK |
986 | list_for_each_entry_rcu(link, &tk->tp.files, list) |
987 | __kprobe_trace_func(tk, regs, link->file); | |
41a7dd42 | 988 | } |
3da0f180 | 989 | NOKPROBE_SYMBOL(kprobe_trace_func); |
41a7dd42 | 990 | |
413d37d1 | 991 | /* Kretprobe handler */ |
3da0f180 | 992 | static nokprobe_inline void |
c31ffb3f | 993 | __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, |
41a7dd42 | 994 | struct pt_regs *regs, |
7f1d2f82 | 995 | struct trace_event_file *trace_file) |
413d37d1 | 996 | { |
93ccae7a | 997 | struct kretprobe_trace_entry_head *entry; |
413d37d1 | 998 | struct ring_buffer_event *event; |
8f8ffe24 | 999 | struct ring_buffer *buffer; |
e09c8614 | 1000 | int size, pc, dsize; |
413d37d1 | 1001 | unsigned long irq_flags; |
2425bcb9 | 1002 | struct trace_event_call *call = &tk->tp.call; |
413d37d1 | 1003 | |
7f1d2f82 | 1004 | WARN_ON(call != trace_file->event_call); |
41a7dd42 | 1005 | |
09a5059a | 1006 | if (trace_trigger_soft_disabled(trace_file)) |
13a1e4ae | 1007 | return; |
b8820084 | 1008 | |
413d37d1 MH |
1009 | local_save_flags(irq_flags); |
1010 | pc = preempt_count(); | |
1011 | ||
c31ffb3f NK |
1012 | dsize = __get_data_size(&tk->tp, regs); |
1013 | size = sizeof(*entry) + tk->tp.size + dsize; | |
413d37d1 | 1014 | |
7f1d2f82 | 1015 | event = trace_event_buffer_lock_reserve(&buffer, trace_file, |
41a7dd42 MH |
1016 | call->event.type, |
1017 | size, irq_flags, pc); | |
413d37d1 | 1018 | if (!event) |
1e12a4a7 | 1019 | return; |
413d37d1 MH |
1020 | |
1021 | entry = ring_buffer_event_data(event); | |
c31ffb3f | 1022 | entry->func = (unsigned long)tk->rp.kp.addr; |
413d37d1 | 1023 | entry->ret_ip = (unsigned long)ri->ret_addr; |
9178412d | 1024 | store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize); |
413d37d1 | 1025 | |
7f1d2f82 | 1026 | event_trigger_unlock_commit_regs(trace_file, buffer, event, |
13a1e4ae | 1027 | entry, irq_flags, pc, regs); |
413d37d1 MH |
1028 | } |
1029 | ||
3da0f180 | 1030 | static void |
c31ffb3f | 1031 | kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, |
41a7dd42 MH |
1032 | struct pt_regs *regs) |
1033 | { | |
b04d52e3 | 1034 | struct event_file_link *link; |
41a7dd42 | 1035 | |
c31ffb3f NK |
1036 | list_for_each_entry_rcu(link, &tk->tp.files, list) |
1037 | __kretprobe_trace_func(tk, ri, regs, link->file); | |
41a7dd42 | 1038 | } |
3da0f180 | 1039 | NOKPROBE_SYMBOL(kretprobe_trace_func); |
41a7dd42 | 1040 | |
413d37d1 | 1041 | /* Event entry printers */ |
b62fdd97 | 1042 | static enum print_line_t |
a9a57763 SR |
1043 | print_kprobe_event(struct trace_iterator *iter, int flags, |
1044 | struct trace_event *event) | |
413d37d1 | 1045 | { |
93ccae7a | 1046 | struct kprobe_trace_entry_head *field; |
413d37d1 | 1047 | struct trace_seq *s = &iter->seq; |
eca0d916 | 1048 | struct trace_probe *tp; |
413d37d1 | 1049 | |
93ccae7a | 1050 | field = (struct kprobe_trace_entry_head *)iter->ent; |
80decc70 | 1051 | tp = container_of(event, struct trace_probe, call.event); |
413d37d1 | 1052 | |
687fcc4a | 1053 | trace_seq_printf(s, "%s: (", trace_event_name(&tp->call)); |
6e9f23d1 | 1054 | |
413d37d1 | 1055 | if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET)) |
85224da0 | 1056 | goto out; |
413d37d1 | 1057 | |
85224da0 | 1058 | trace_seq_putc(s, ')'); |
413d37d1 | 1059 | |
56de7630 MH |
1060 | if (print_probe_args(s, tp->args, tp->nr_args, |
1061 | (u8 *)&field[1], field) < 0) | |
1062 | goto out; | |
413d37d1 | 1063 | |
85224da0 SRRH |
1064 | trace_seq_putc(s, '\n'); |
1065 | out: | |
1066 | return trace_handle_return(s); | |
413d37d1 MH |
1067 | } |
1068 | ||
b62fdd97 | 1069 | static enum print_line_t |
a9a57763 SR |
1070 | print_kretprobe_event(struct trace_iterator *iter, int flags, |
1071 | struct trace_event *event) | |
413d37d1 | 1072 | { |
93ccae7a | 1073 | struct kretprobe_trace_entry_head *field; |
413d37d1 | 1074 | struct trace_seq *s = &iter->seq; |
eca0d916 | 1075 | struct trace_probe *tp; |
413d37d1 | 1076 | |
93ccae7a | 1077 | field = (struct kretprobe_trace_entry_head *)iter->ent; |
80decc70 | 1078 | tp = container_of(event, struct trace_probe, call.event); |
413d37d1 | 1079 | |
687fcc4a | 1080 | trace_seq_printf(s, "%s: (", trace_event_name(&tp->call)); |
6e9f23d1 | 1081 | |
413d37d1 | 1082 | if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET)) |
85224da0 | 1083 | goto out; |
413d37d1 | 1084 | |
85224da0 | 1085 | trace_seq_puts(s, " <- "); |
413d37d1 MH |
1086 | |
1087 | if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET)) | |
85224da0 | 1088 | goto out; |
413d37d1 | 1089 | |
85224da0 | 1090 | trace_seq_putc(s, ')'); |
413d37d1 | 1091 | |
56de7630 MH |
1092 | if (print_probe_args(s, tp->args, tp->nr_args, |
1093 | (u8 *)&field[1], field) < 0) | |
1094 | goto out; | |
413d37d1 | 1095 | |
85224da0 | 1096 | trace_seq_putc(s, '\n'); |
413d37d1 | 1097 | |
85224da0 SRRH |
1098 | out: |
1099 | return trace_handle_return(s); | |
413d37d1 MH |
1100 | } |
1101 | ||
413d37d1 | 1102 | |
2425bcb9 | 1103 | static int kprobe_event_define_fields(struct trace_event_call *event_call) |
413d37d1 | 1104 | { |
eeb07b06 | 1105 | int ret; |
93ccae7a | 1106 | struct kprobe_trace_entry_head field; |
c31ffb3f | 1107 | struct trace_kprobe *tk = (struct trace_kprobe *)event_call->data; |
413d37d1 | 1108 | |
a703d946 | 1109 | DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0); |
c31ffb3f | 1110 | |
eeb07b06 | 1111 | return traceprobe_define_arg_fields(event_call, sizeof(field), &tk->tp); |
413d37d1 MH |
1112 | } |
1113 | ||
2425bcb9 | 1114 | static int kretprobe_event_define_fields(struct trace_event_call *event_call) |
413d37d1 | 1115 | { |
eeb07b06 | 1116 | int ret; |
93ccae7a | 1117 | struct kretprobe_trace_entry_head field; |
c31ffb3f | 1118 | struct trace_kprobe *tk = (struct trace_kprobe *)event_call->data; |
413d37d1 | 1119 | |
a703d946 MH |
1120 | DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0); |
1121 | DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0); | |
c31ffb3f | 1122 | |
eeb07b06 | 1123 | return traceprobe_define_arg_fields(event_call, sizeof(field), &tk->tp); |
413d37d1 MH |
1124 | } |
1125 | ||
07b139c8 | 1126 | #ifdef CONFIG_PERF_EVENTS |
e08d1c65 MH |
1127 | |
1128 | /* Kprobe profile handler */ | |
9802d865 | 1129 | static int |
c31ffb3f | 1130 | kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs) |
e08d1c65 | 1131 | { |
2425bcb9 | 1132 | struct trace_event_call *call = &tk->tp.call; |
93ccae7a | 1133 | struct kprobe_trace_entry_head *entry; |
1c024eca | 1134 | struct hlist_head *head; |
e09c8614 | 1135 | int size, __size, dsize; |
4ed7c92d | 1136 | int rctx; |
e08d1c65 | 1137 | |
9802d865 | 1138 | if (bpf_prog_array_valid(call)) { |
66665ad2 | 1139 | unsigned long orig_ip = instruction_pointer(regs); |
9802d865 JB |
1140 | int ret; |
1141 | ||
1142 | ret = trace_call_bpf(call, regs); | |
1143 | ||
1144 | /* | |
1145 | * We need to check and see if we modified the pc of the | |
cce188bd MH |
1146 | * pt_regs, and if so return 1 so that we don't do the |
1147 | * single stepping. | |
9802d865 | 1148 | */ |
cce188bd | 1149 | if (orig_ip != instruction_pointer(regs)) |
9802d865 | 1150 | return 1; |
9802d865 JB |
1151 | if (!ret) |
1152 | return 0; | |
1153 | } | |
2541517c | 1154 | |
288e984e ON |
1155 | head = this_cpu_ptr(call->perf_events); |
1156 | if (hlist_empty(head)) | |
9802d865 | 1157 | return 0; |
288e984e | 1158 | |
c31ffb3f NK |
1159 | dsize = __get_data_size(&tk->tp, regs); |
1160 | __size = sizeof(*entry) + tk->tp.size + dsize; | |
74ebb63e MH |
1161 | size = ALIGN(__size + sizeof(u32), sizeof(u64)); |
1162 | size -= sizeof(u32); | |
ce71b9df | 1163 | |
1e1dcd93 | 1164 | entry = perf_trace_buf_alloc(size, NULL, &rctx); |
430ad5a6 | 1165 | if (!entry) |
9802d865 | 1166 | return 0; |
a1a138d0 | 1167 | |
c31ffb3f | 1168 | entry->ip = (unsigned long)tk->rp.kp.addr; |
e09c8614 | 1169 | memset(&entry[1], 0, dsize); |
9178412d | 1170 | store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize); |
1e1dcd93 | 1171 | perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, |
8fd0fbbe | 1172 | head, NULL); |
9802d865 | 1173 | return 0; |
e08d1c65 | 1174 | } |
3da0f180 | 1175 | NOKPROBE_SYMBOL(kprobe_perf_func); |
e08d1c65 MH |
1176 | |
1177 | /* Kretprobe profile handler */ | |
3da0f180 | 1178 | static void |
c31ffb3f | 1179 | kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, |
2b106aab | 1180 | struct pt_regs *regs) |
e08d1c65 | 1181 | { |
2425bcb9 | 1182 | struct trace_event_call *call = &tk->tp.call; |
93ccae7a | 1183 | struct kretprobe_trace_entry_head *entry; |
1c024eca | 1184 | struct hlist_head *head; |
e09c8614 | 1185 | int size, __size, dsize; |
4ed7c92d | 1186 | int rctx; |
e08d1c65 | 1187 | |
e87c6bc3 | 1188 | if (bpf_prog_array_valid(call) && !trace_call_bpf(call, regs)) |
2541517c AS |
1189 | return; |
1190 | ||
288e984e ON |
1191 | head = this_cpu_ptr(call->perf_events); |
1192 | if (hlist_empty(head)) | |
1193 | return; | |
1194 | ||
c31ffb3f NK |
1195 | dsize = __get_data_size(&tk->tp, regs); |
1196 | __size = sizeof(*entry) + tk->tp.size + dsize; | |
74ebb63e MH |
1197 | size = ALIGN(__size + sizeof(u32), sizeof(u64)); |
1198 | size -= sizeof(u32); | |
444a2a3b | 1199 | |
1e1dcd93 | 1200 | entry = perf_trace_buf_alloc(size, NULL, &rctx); |
430ad5a6 | 1201 | if (!entry) |
1e12a4a7 | 1202 | return; |
e08d1c65 | 1203 | |
c31ffb3f | 1204 | entry->func = (unsigned long)tk->rp.kp.addr; |
a1a138d0 | 1205 | entry->ret_ip = (unsigned long)ri->ret_addr; |
9178412d | 1206 | store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize); |
1e1dcd93 | 1207 | perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, |
8fd0fbbe | 1208 | head, NULL); |
e08d1c65 | 1209 | } |
3da0f180 | 1210 | NOKPROBE_SYMBOL(kretprobe_perf_func); |
41bdc4b4 YS |
1211 | |
1212 | int bpf_get_kprobe_info(const struct perf_event *event, u32 *fd_type, | |
1213 | const char **symbol, u64 *probe_offset, | |
1214 | u64 *probe_addr, bool perf_type_tracepoint) | |
1215 | { | |
1216 | const char *pevent = trace_event_name(event->tp_event); | |
1217 | const char *group = event->tp_event->class->system; | |
1218 | struct trace_kprobe *tk; | |
1219 | ||
1220 | if (perf_type_tracepoint) | |
1221 | tk = find_trace_kprobe(pevent, group); | |
1222 | else | |
1223 | tk = event->tp_event->data; | |
1224 | if (!tk) | |
1225 | return -EINVAL; | |
1226 | ||
1227 | *fd_type = trace_kprobe_is_return(tk) ? BPF_FD_TYPE_KRETPROBE | |
1228 | : BPF_FD_TYPE_KPROBE; | |
1229 | if (tk->symbol) { | |
1230 | *symbol = tk->symbol; | |
1231 | *probe_offset = tk->rp.kp.offset; | |
1232 | *probe_addr = 0; | |
1233 | } else { | |
1234 | *symbol = NULL; | |
1235 | *probe_offset = 0; | |
1236 | *probe_addr = (unsigned long)tk->rp.kp.addr; | |
1237 | } | |
1238 | return 0; | |
1239 | } | |
07b139c8 | 1240 | #endif /* CONFIG_PERF_EVENTS */ |
50d78056 | 1241 | |
3fe3d619 ON |
1242 | /* |
1243 | * called by perf_trace_init() or __ftrace_set_clr_event() under event_mutex. | |
1244 | * | |
1245 | * kprobe_trace_self_tests_init() does enable_trace_probe/disable_trace_probe | |
1246 | * lockless, but we can't race with this __init function. | |
1247 | */ | |
2425bcb9 | 1248 | static int kprobe_register(struct trace_event_call *event, |
fbc1963d | 1249 | enum trace_reg type, void *data) |
2239291a | 1250 | { |
c31ffb3f | 1251 | struct trace_kprobe *tk = (struct trace_kprobe *)event->data; |
7f1d2f82 | 1252 | struct trace_event_file *file = data; |
1538f888 | 1253 | |
2239291a SR |
1254 | switch (type) { |
1255 | case TRACE_REG_REGISTER: | |
c31ffb3f | 1256 | return enable_trace_kprobe(tk, file); |
2239291a | 1257 | case TRACE_REG_UNREGISTER: |
c31ffb3f | 1258 | return disable_trace_kprobe(tk, file); |
2239291a SR |
1259 | |
1260 | #ifdef CONFIG_PERF_EVENTS | |
1261 | case TRACE_REG_PERF_REGISTER: | |
c31ffb3f | 1262 | return enable_trace_kprobe(tk, NULL); |
2239291a | 1263 | case TRACE_REG_PERF_UNREGISTER: |
c31ffb3f | 1264 | return disable_trace_kprobe(tk, NULL); |
ceec0b6f JO |
1265 | case TRACE_REG_PERF_OPEN: |
1266 | case TRACE_REG_PERF_CLOSE: | |
489c75c3 JO |
1267 | case TRACE_REG_PERF_ADD: |
1268 | case TRACE_REG_PERF_DEL: | |
ceec0b6f | 1269 | return 0; |
2239291a SR |
1270 | #endif |
1271 | } | |
1272 | return 0; | |
1273 | } | |
50d78056 | 1274 | |
3da0f180 | 1275 | static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs) |
50d78056 | 1276 | { |
c31ffb3f | 1277 | struct trace_kprobe *tk = container_of(kp, struct trace_kprobe, rp.kp); |
9802d865 | 1278 | int ret = 0; |
e08d1c65 | 1279 | |
a7636d9e | 1280 | raw_cpu_inc(*tk->nhit); |
48182bd2 | 1281 | |
c31ffb3f NK |
1282 | if (tk->tp.flags & TP_FLAG_TRACE) |
1283 | kprobe_trace_func(tk, regs); | |
07b139c8 | 1284 | #ifdef CONFIG_PERF_EVENTS |
c31ffb3f | 1285 | if (tk->tp.flags & TP_FLAG_PROFILE) |
9802d865 | 1286 | ret = kprobe_perf_func(tk, regs); |
07b139c8 | 1287 | #endif |
9802d865 | 1288 | return ret; |
50d78056 | 1289 | } |
3da0f180 | 1290 | NOKPROBE_SYMBOL(kprobe_dispatcher); |
50d78056 | 1291 | |
3da0f180 MH |
1292 | static int |
1293 | kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs) | |
50d78056 | 1294 | { |
c31ffb3f | 1295 | struct trace_kprobe *tk = container_of(ri->rp, struct trace_kprobe, rp); |
50d78056 | 1296 | |
a7636d9e | 1297 | raw_cpu_inc(*tk->nhit); |
48182bd2 | 1298 | |
c31ffb3f NK |
1299 | if (tk->tp.flags & TP_FLAG_TRACE) |
1300 | kretprobe_trace_func(tk, ri, regs); | |
07b139c8 | 1301 | #ifdef CONFIG_PERF_EVENTS |
c31ffb3f NK |
1302 | if (tk->tp.flags & TP_FLAG_PROFILE) |
1303 | kretprobe_perf_func(tk, ri, regs); | |
07b139c8 | 1304 | #endif |
50d78056 MH |
1305 | return 0; /* We don't tweek kernel, so just return 0 */ |
1306 | } | |
3da0f180 | 1307 | NOKPROBE_SYMBOL(kretprobe_dispatcher); |
e08d1c65 | 1308 | |
a9a57763 SR |
1309 | static struct trace_event_functions kretprobe_funcs = { |
1310 | .trace = print_kretprobe_event | |
1311 | }; | |
1312 | ||
1313 | static struct trace_event_functions kprobe_funcs = { | |
1314 | .trace = print_kprobe_event | |
1315 | }; | |
1316 | ||
e12f03d7 SL |
1317 | static inline void init_trace_event_call(struct trace_kprobe *tk, |
1318 | struct trace_event_call *call) | |
413d37d1 | 1319 | { |
ffb9f995 | 1320 | INIT_LIST_HEAD(&call->class->fields); |
c31ffb3f | 1321 | if (trace_kprobe_is_return(tk)) { |
80decc70 | 1322 | call->event.funcs = &kretprobe_funcs; |
2e33af02 | 1323 | call->class->define_fields = kretprobe_event_define_fields; |
413d37d1 | 1324 | } else { |
80decc70 | 1325 | call->event.funcs = &kprobe_funcs; |
2e33af02 | 1326 | call->class->define_fields = kprobe_event_define_fields; |
413d37d1 | 1327 | } |
e12f03d7 SL |
1328 | |
1329 | call->flags = TRACE_EVENT_FL_KPROBE; | |
1330 | call->class->reg = kprobe_register; | |
1331 | call->data = tk; | |
1332 | } | |
1333 | ||
1334 | static int register_kprobe_event(struct trace_kprobe *tk) | |
1335 | { | |
1336 | struct trace_event_call *call = &tk->tp.call; | |
1337 | int ret = 0; | |
1338 | ||
1339 | init_trace_event_call(tk, call); | |
1340 | ||
0a46c854 | 1341 | if (traceprobe_set_print_fmt(&tk->tp, trace_kprobe_is_return(tk)) < 0) |
a342a028 | 1342 | return -ENOMEM; |
9023c930 | 1343 | ret = register_trace_event(&call->event); |
32c0edae | 1344 | if (!ret) { |
a342a028 | 1345 | kfree(call->print_fmt); |
ff50d991 | 1346 | return -ENODEV; |
a342a028 | 1347 | } |
413d37d1 | 1348 | ret = trace_add_event_call(call); |
ff50d991 | 1349 | if (ret) { |
de7b2973 | 1350 | pr_info("Failed to register kprobe event: %s\n", |
687fcc4a | 1351 | trace_event_name(call)); |
a342a028 | 1352 | kfree(call->print_fmt); |
9023c930 | 1353 | unregister_trace_event(&call->event); |
ff50d991 | 1354 | } |
413d37d1 MH |
1355 | return ret; |
1356 | } | |
1357 | ||
c31ffb3f | 1358 | static int unregister_kprobe_event(struct trace_kprobe *tk) |
413d37d1 | 1359 | { |
40c32592 SRRH |
1360 | int ret; |
1361 | ||
ff50d991 | 1362 | /* tp->event is unregistered in trace_remove_event_call() */ |
c31ffb3f | 1363 | ret = trace_remove_event_call(&tk->tp.call); |
40c32592 | 1364 | if (!ret) |
c31ffb3f | 1365 | kfree(tk->tp.call.print_fmt); |
40c32592 | 1366 | return ret; |
413d37d1 MH |
1367 | } |
1368 | ||
e12f03d7 SL |
1369 | #ifdef CONFIG_PERF_EVENTS |
1370 | /* create a trace_kprobe, but don't add it to global lists */ | |
1371 | struct trace_event_call * | |
1372 | create_local_trace_kprobe(char *func, void *addr, unsigned long offs, | |
1373 | bool is_return) | |
1374 | { | |
1375 | struct trace_kprobe *tk; | |
1376 | int ret; | |
1377 | char *event; | |
1378 | ||
1379 | /* | |
1380 | * local trace_kprobes are not added to probe_list, so they are never | |
1381 | * searched in find_trace_kprobe(). Therefore, there is no concern of | |
1382 | * duplicated name here. | |
1383 | */ | |
1384 | event = func ? func : "DUMMY_EVENT"; | |
1385 | ||
1386 | tk = alloc_trace_kprobe(KPROBE_EVENT_SYSTEM, event, (void *)addr, func, | |
1387 | offs, 0 /* maxactive */, 0 /* nargs */, | |
1388 | is_return); | |
1389 | ||
1390 | if (IS_ERR(tk)) { | |
1391 | pr_info("Failed to allocate trace_probe.(%d)\n", | |
1392 | (int)PTR_ERR(tk)); | |
1393 | return ERR_CAST(tk); | |
1394 | } | |
1395 | ||
1396 | init_trace_event_call(tk, &tk->tp.call); | |
1397 | ||
0a46c854 | 1398 | if (traceprobe_set_print_fmt(&tk->tp, trace_kprobe_is_return(tk)) < 0) { |
e12f03d7 SL |
1399 | ret = -ENOMEM; |
1400 | goto error; | |
1401 | } | |
1402 | ||
1403 | ret = __register_trace_kprobe(tk); | |
0fc8c358 JO |
1404 | if (ret < 0) { |
1405 | kfree(tk->tp.call.print_fmt); | |
e12f03d7 | 1406 | goto error; |
0fc8c358 | 1407 | } |
e12f03d7 SL |
1408 | |
1409 | return &tk->tp.call; | |
1410 | error: | |
1411 | free_trace_kprobe(tk); | |
1412 | return ERR_PTR(ret); | |
1413 | } | |
1414 | ||
1415 | void destroy_local_trace_kprobe(struct trace_event_call *event_call) | |
1416 | { | |
1417 | struct trace_kprobe *tk; | |
1418 | ||
1419 | tk = container_of(event_call, struct trace_kprobe, tp.call); | |
1420 | ||
1421 | if (trace_probe_is_enabled(&tk->tp)) { | |
1422 | WARN_ON(1); | |
1423 | return; | |
1424 | } | |
1425 | ||
1426 | __unregister_trace_kprobe(tk); | |
0fc8c358 JO |
1427 | |
1428 | kfree(tk->tp.call.print_fmt); | |
e12f03d7 SL |
1429 | free_trace_kprobe(tk); |
1430 | } | |
1431 | #endif /* CONFIG_PERF_EVENTS */ | |
1432 | ||
8434dc93 | 1433 | /* Make a tracefs interface for controlling probe points */ |
413d37d1 MH |
1434 | static __init int init_kprobe_trace(void) |
1435 | { | |
1436 | struct dentry *d_tracer; | |
1437 | struct dentry *entry; | |
413d37d1 | 1438 | |
c31ffb3f | 1439 | if (register_module_notifier(&trace_kprobe_module_nb)) |
61424318 MH |
1440 | return -EINVAL; |
1441 | ||
413d37d1 | 1442 | d_tracer = tracing_init_dentry(); |
14a5ae40 | 1443 | if (IS_ERR(d_tracer)) |
413d37d1 MH |
1444 | return 0; |
1445 | ||
8434dc93 | 1446 | entry = tracefs_create_file("kprobe_events", 0644, d_tracer, |
413d37d1 MH |
1447 | NULL, &kprobe_events_ops); |
1448 | ||
cd7e7bd5 | 1449 | /* Event list interface */ |
413d37d1 | 1450 | if (!entry) |
a395d6a7 | 1451 | pr_warn("Could not create tracefs 'kprobe_events' entry\n"); |
cd7e7bd5 MH |
1452 | |
1453 | /* Profile interface */ | |
8434dc93 | 1454 | entry = tracefs_create_file("kprobe_profile", 0444, d_tracer, |
cd7e7bd5 MH |
1455 | NULL, &kprobe_profile_ops); |
1456 | ||
1457 | if (!entry) | |
a395d6a7 | 1458 | pr_warn("Could not create tracefs 'kprobe_profile' entry\n"); |
413d37d1 MH |
1459 | return 0; |
1460 | } | |
1461 | fs_initcall(init_kprobe_trace); | |
1462 | ||
1463 | ||
1464 | #ifdef CONFIG_FTRACE_STARTUP_TEST | |
26a346f2 | 1465 | static __init struct trace_event_file * |
c31ffb3f | 1466 | find_trace_probe_file(struct trace_kprobe *tk, struct trace_array *tr) |
41a7dd42 | 1467 | { |
7f1d2f82 | 1468 | struct trace_event_file *file; |
41a7dd42 MH |
1469 | |
1470 | list_for_each_entry(file, &tr->events, list) | |
c31ffb3f | 1471 | if (file->event_call == &tk->tp.call) |
41a7dd42 MH |
1472 | return file; |
1473 | ||
1474 | return NULL; | |
1475 | } | |
1476 | ||
3fe3d619 | 1477 | /* |
c31ffb3f | 1478 | * Nobody but us can call enable_trace_kprobe/disable_trace_kprobe at this |
3fe3d619 ON |
1479 | * stage, we can do this lockless. |
1480 | */ | |
413d37d1 MH |
1481 | static __init int kprobe_trace_self_tests_init(void) |
1482 | { | |
231e36f4 | 1483 | int ret, warn = 0; |
413d37d1 | 1484 | int (*target)(int, int, int, int, int, int); |
c31ffb3f | 1485 | struct trace_kprobe *tk; |
7f1d2f82 | 1486 | struct trace_event_file *file; |
413d37d1 | 1487 | |
748ec3a2 YY |
1488 | if (tracing_is_disabled()) |
1489 | return -ENODEV; | |
1490 | ||
413d37d1 MH |
1491 | target = kprobe_trace_selftest_target; |
1492 | ||
1493 | pr_info("Testing kprobe tracing: "); | |
1494 | ||
7e465baa TZ |
1495 | ret = trace_run_command("p:testprobe kprobe_trace_selftest_target " |
1496 | "$stack $stack0 +0($stack)", | |
1497 | create_trace_kprobe); | |
231e36f4 | 1498 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 1499 | pr_warn("error on probing function entry.\n"); |
231e36f4 MH |
1500 | warn++; |
1501 | } else { | |
1502 | /* Enable trace point */ | |
c31ffb3f NK |
1503 | tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM); |
1504 | if (WARN_ON_ONCE(tk == NULL)) { | |
41a7dd42 | 1505 | pr_warn("error on getting new probe.\n"); |
231e36f4 | 1506 | warn++; |
41a7dd42 | 1507 | } else { |
c31ffb3f | 1508 | file = find_trace_probe_file(tk, top_trace_array()); |
41a7dd42 MH |
1509 | if (WARN_ON_ONCE(file == NULL)) { |
1510 | pr_warn("error on getting probe file.\n"); | |
1511 | warn++; | |
1512 | } else | |
c31ffb3f | 1513 | enable_trace_kprobe(tk, file); |
41a7dd42 | 1514 | } |
231e36f4 | 1515 | } |
413d37d1 | 1516 | |
7e465baa TZ |
1517 | ret = trace_run_command("r:testprobe2 kprobe_trace_selftest_target " |
1518 | "$retval", create_trace_kprobe); | |
231e36f4 | 1519 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 1520 | pr_warn("error on probing function return.\n"); |
231e36f4 MH |
1521 | warn++; |
1522 | } else { | |
1523 | /* Enable trace point */ | |
c31ffb3f NK |
1524 | tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM); |
1525 | if (WARN_ON_ONCE(tk == NULL)) { | |
41a7dd42 | 1526 | pr_warn("error on getting 2nd new probe.\n"); |
231e36f4 | 1527 | warn++; |
41a7dd42 | 1528 | } else { |
c31ffb3f | 1529 | file = find_trace_probe_file(tk, top_trace_array()); |
41a7dd42 MH |
1530 | if (WARN_ON_ONCE(file == NULL)) { |
1531 | pr_warn("error on getting probe file.\n"); | |
1532 | warn++; | |
1533 | } else | |
c31ffb3f | 1534 | enable_trace_kprobe(tk, file); |
41a7dd42 | 1535 | } |
231e36f4 MH |
1536 | } |
1537 | ||
1538 | if (warn) | |
1539 | goto end; | |
413d37d1 MH |
1540 | |
1541 | ret = target(1, 2, 3, 4, 5, 6); | |
1542 | ||
d4d7ccc8 MN |
1543 | /* |
1544 | * Not expecting an error here, the check is only to prevent the | |
1545 | * optimizer from removing the call to target() as otherwise there | |
1546 | * are no side-effects and the call is never performed. | |
1547 | */ | |
1548 | if (ret != 21) | |
1549 | warn++; | |
1550 | ||
02ca1521 | 1551 | /* Disable trace points before removing it */ |
c31ffb3f NK |
1552 | tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM); |
1553 | if (WARN_ON_ONCE(tk == NULL)) { | |
41a7dd42 | 1554 | pr_warn("error on getting test probe.\n"); |
02ca1521 | 1555 | warn++; |
41a7dd42 | 1556 | } else { |
d4d7ccc8 MN |
1557 | if (trace_kprobe_nhit(tk) != 1) { |
1558 | pr_warn("incorrect number of testprobe hits\n"); | |
1559 | warn++; | |
1560 | } | |
1561 | ||
c31ffb3f | 1562 | file = find_trace_probe_file(tk, top_trace_array()); |
41a7dd42 MH |
1563 | if (WARN_ON_ONCE(file == NULL)) { |
1564 | pr_warn("error on getting probe file.\n"); | |
1565 | warn++; | |
1566 | } else | |
c31ffb3f | 1567 | disable_trace_kprobe(tk, file); |
41a7dd42 | 1568 | } |
02ca1521 | 1569 | |
c31ffb3f NK |
1570 | tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM); |
1571 | if (WARN_ON_ONCE(tk == NULL)) { | |
41a7dd42 | 1572 | pr_warn("error on getting 2nd test probe.\n"); |
02ca1521 | 1573 | warn++; |
41a7dd42 | 1574 | } else { |
d4d7ccc8 MN |
1575 | if (trace_kprobe_nhit(tk) != 1) { |
1576 | pr_warn("incorrect number of testprobe2 hits\n"); | |
1577 | warn++; | |
1578 | } | |
1579 | ||
c31ffb3f | 1580 | file = find_trace_probe_file(tk, top_trace_array()); |
41a7dd42 MH |
1581 | if (WARN_ON_ONCE(file == NULL)) { |
1582 | pr_warn("error on getting probe file.\n"); | |
1583 | warn++; | |
1584 | } else | |
c31ffb3f | 1585 | disable_trace_kprobe(tk, file); |
41a7dd42 | 1586 | } |
02ca1521 | 1587 | |
7e465baa | 1588 | ret = trace_run_command("-:testprobe", create_trace_kprobe); |
231e36f4 | 1589 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 1590 | pr_warn("error on deleting a probe.\n"); |
231e36f4 MH |
1591 | warn++; |
1592 | } | |
1593 | ||
7e465baa | 1594 | ret = trace_run_command("-:testprobe2", create_trace_kprobe); |
231e36f4 | 1595 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 1596 | pr_warn("error on deleting a probe.\n"); |
231e36f4 MH |
1597 | warn++; |
1598 | } | |
413d37d1 | 1599 | |
231e36f4 | 1600 | end: |
c31ffb3f | 1601 | release_all_trace_kprobes(); |
30e7d894 TG |
1602 | /* |
1603 | * Wait for the optimizer work to finish. Otherwise it might fiddle | |
1604 | * with probes in already freed __init text. | |
1605 | */ | |
1606 | wait_for_kprobe_optimizer(); | |
231e36f4 MH |
1607 | if (warn) |
1608 | pr_cont("NG: Some tests are failed. Please check them.\n"); | |
1609 | else | |
1610 | pr_cont("OK\n"); | |
413d37d1 MH |
1611 | return 0; |
1612 | } | |
1613 | ||
1614 | late_initcall(kprobe_trace_self_tests_init); | |
1615 | ||
1616 | #endif |