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Commit | Line | Data |
---|---|---|
413d37d1 | 1 | /* |
77b44d1b | 2 | * Kprobes-based tracing events |
413d37d1 MH |
3 | * |
4 | * Created by Masami Hiramatsu <mhiramat@redhat.com> | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License version 2 as | |
8 | * published by the Free Software Foundation. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, | |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | * GNU General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License | |
16 | * along with this program; if not, write to the Free Software | |
17 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
18 | */ | |
19 | ||
20 | #include <linux/module.h> | |
21 | #include <linux/uaccess.h> | |
413d37d1 | 22 | |
8ab83f56 | 23 | #include "trace_probe.h" |
1ff511e3 | 24 | |
8ab83f56 | 25 | #define KPROBE_EVENT_SYSTEM "kprobes" |
e09c8614 | 26 | |
413d37d1 | 27 | /** |
77b44d1b | 28 | * Kprobe event core functions |
413d37d1 | 29 | */ |
c31ffb3f | 30 | struct trace_kprobe { |
413d37d1 | 31 | struct list_head list; |
4a846b44 | 32 | struct kretprobe rp; /* Use rp.kp for kprobe use */ |
cd7e7bd5 | 33 | unsigned long nhit; |
413d37d1 | 34 | const char *symbol; /* symbol name */ |
c31ffb3f | 35 | struct trace_probe tp; |
413d37d1 MH |
36 | }; |
37 | ||
b04d52e3 ON |
38 | struct event_file_link { |
39 | struct ftrace_event_file *file; | |
40 | struct list_head list; | |
41 | }; | |
42 | ||
c31ffb3f NK |
43 | #define SIZEOF_TRACE_KPROBE(n) \ |
44 | (offsetof(struct trace_kprobe, tp.args) + \ | |
eca0d916 | 45 | (sizeof(struct probe_arg) * (n))) |
a82378d8 | 46 | |
93ccae7a | 47 | |
c31ffb3f | 48 | static __kprobes bool trace_kprobe_is_return(struct trace_kprobe *tk) |
413d37d1 | 49 | { |
c31ffb3f | 50 | return tk->rp.handler != NULL; |
413d37d1 MH |
51 | } |
52 | ||
c31ffb3f | 53 | static __kprobes const char *trace_kprobe_symbol(struct trace_kprobe *tk) |
413d37d1 | 54 | { |
c31ffb3f | 55 | return tk->symbol ? tk->symbol : "unknown"; |
413d37d1 MH |
56 | } |
57 | ||
c31ffb3f | 58 | static __kprobes unsigned long trace_kprobe_offset(struct trace_kprobe *tk) |
61424318 | 59 | { |
c31ffb3f | 60 | return tk->rp.kp.offset; |
61424318 MH |
61 | } |
62 | ||
c31ffb3f | 63 | static __kprobes bool trace_kprobe_has_gone(struct trace_kprobe *tk) |
61424318 | 64 | { |
c31ffb3f | 65 | return !!(kprobe_gone(&tk->rp.kp)); |
61424318 MH |
66 | } |
67 | ||
c31ffb3f NK |
68 | static __kprobes bool trace_kprobe_within_module(struct trace_kprobe *tk, |
69 | struct module *mod) | |
61424318 MH |
70 | { |
71 | int len = strlen(mod->name); | |
c31ffb3f | 72 | const char *name = trace_kprobe_symbol(tk); |
61424318 MH |
73 | return strncmp(mod->name, name, len) == 0 && name[len] == ':'; |
74 | } | |
75 | ||
c31ffb3f | 76 | static __kprobes bool trace_kprobe_is_on_module(struct trace_kprobe *tk) |
61424318 | 77 | { |
c31ffb3f | 78 | return !!strchr(trace_kprobe_symbol(tk), ':'); |
61424318 MH |
79 | } |
80 | ||
c31ffb3f NK |
81 | static int register_kprobe_event(struct trace_kprobe *tk); |
82 | static int unregister_kprobe_event(struct trace_kprobe *tk); | |
413d37d1 MH |
83 | |
84 | static DEFINE_MUTEX(probe_lock); | |
85 | static LIST_HEAD(probe_list); | |
86 | ||
50d78056 MH |
87 | static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs); |
88 | static int kretprobe_dispatcher(struct kretprobe_instance *ri, | |
89 | struct pt_regs *regs); | |
90 | ||
4a846b44 MH |
91 | /* |
92 | * Allocate new trace_probe and initialize it (including kprobes). | |
93 | */ | |
c31ffb3f | 94 | static struct trace_kprobe *alloc_trace_kprobe(const char *group, |
f52487e9 | 95 | const char *event, |
4a846b44 MH |
96 | void *addr, |
97 | const char *symbol, | |
98 | unsigned long offs, | |
3a6b7666 | 99 | int nargs, bool is_return) |
413d37d1 | 100 | { |
c31ffb3f | 101 | struct trace_kprobe *tk; |
6f3cf440 | 102 | int ret = -ENOMEM; |
413d37d1 | 103 | |
c31ffb3f NK |
104 | tk = kzalloc(SIZEOF_TRACE_KPROBE(nargs), GFP_KERNEL); |
105 | if (!tk) | |
6f3cf440 | 106 | return ERR_PTR(ret); |
413d37d1 MH |
107 | |
108 | if (symbol) { | |
c31ffb3f NK |
109 | tk->symbol = kstrdup(symbol, GFP_KERNEL); |
110 | if (!tk->symbol) | |
413d37d1 | 111 | goto error; |
c31ffb3f NK |
112 | tk->rp.kp.symbol_name = tk->symbol; |
113 | tk->rp.kp.offset = offs; | |
4a846b44 | 114 | } else |
c31ffb3f | 115 | tk->rp.kp.addr = addr; |
4a846b44 MH |
116 | |
117 | if (is_return) | |
c31ffb3f | 118 | tk->rp.handler = kretprobe_dispatcher; |
4a846b44 | 119 | else |
c31ffb3f | 120 | tk->rp.kp.pre_handler = kprobe_dispatcher; |
4a846b44 | 121 | |
da34634f | 122 | if (!event || !is_good_name(event)) { |
6f3cf440 | 123 | ret = -EINVAL; |
4263565d | 124 | goto error; |
6f3cf440 MH |
125 | } |
126 | ||
c31ffb3f NK |
127 | tk->tp.call.class = &tk->tp.class; |
128 | tk->tp.call.name = kstrdup(event, GFP_KERNEL); | |
129 | if (!tk->tp.call.name) | |
4263565d | 130 | goto error; |
413d37d1 | 131 | |
da34634f | 132 | if (!group || !is_good_name(group)) { |
6f3cf440 | 133 | ret = -EINVAL; |
f52487e9 | 134 | goto error; |
6f3cf440 MH |
135 | } |
136 | ||
c31ffb3f NK |
137 | tk->tp.class.system = kstrdup(group, GFP_KERNEL); |
138 | if (!tk->tp.class.system) | |
f52487e9 MH |
139 | goto error; |
140 | ||
c31ffb3f NK |
141 | INIT_LIST_HEAD(&tk->list); |
142 | INIT_LIST_HEAD(&tk->tp.files); | |
143 | return tk; | |
413d37d1 | 144 | error: |
c31ffb3f NK |
145 | kfree(tk->tp.call.name); |
146 | kfree(tk->symbol); | |
147 | kfree(tk); | |
6f3cf440 | 148 | return ERR_PTR(ret); |
413d37d1 MH |
149 | } |
150 | ||
c31ffb3f | 151 | static void free_trace_kprobe(struct trace_kprobe *tk) |
413d37d1 MH |
152 | { |
153 | int i; | |
154 | ||
c31ffb3f NK |
155 | for (i = 0; i < tk->tp.nr_args; i++) |
156 | traceprobe_free_probe_arg(&tk->tp.args[i]); | |
413d37d1 | 157 | |
c31ffb3f NK |
158 | kfree(tk->tp.call.class->system); |
159 | kfree(tk->tp.call.name); | |
160 | kfree(tk->symbol); | |
161 | kfree(tk); | |
413d37d1 MH |
162 | } |
163 | ||
c31ffb3f NK |
164 | static struct trace_kprobe *find_trace_kprobe(const char *event, |
165 | const char *group) | |
413d37d1 | 166 | { |
c31ffb3f | 167 | struct trace_kprobe *tk; |
413d37d1 | 168 | |
c31ffb3f NK |
169 | list_for_each_entry(tk, &probe_list, list) |
170 | if (strcmp(tk->tp.call.name, event) == 0 && | |
171 | strcmp(tk->tp.call.class->system, group) == 0) | |
172 | return tk; | |
413d37d1 MH |
173 | return NULL; |
174 | } | |
175 | ||
41a7dd42 MH |
176 | /* |
177 | * Enable trace_probe | |
178 | * if the file is NULL, enable "perf" handler, or enable "trace" handler. | |
179 | */ | |
180 | static int | |
c31ffb3f | 181 | enable_trace_kprobe(struct trace_kprobe *tk, struct ftrace_event_file *file) |
1538f888 MH |
182 | { |
183 | int ret = 0; | |
184 | ||
41a7dd42 | 185 | if (file) { |
b04d52e3 ON |
186 | struct event_file_link *link; |
187 | ||
188 | link = kmalloc(sizeof(*link), GFP_KERNEL); | |
189 | if (!link) { | |
41a7dd42 | 190 | ret = -ENOMEM; |
3fe3d619 | 191 | goto out; |
41a7dd42 | 192 | } |
41a7dd42 | 193 | |
b04d52e3 | 194 | link->file = file; |
c31ffb3f | 195 | list_add_tail_rcu(&link->list, &tk->tp.files); |
41a7dd42 | 196 | |
c31ffb3f | 197 | tk->tp.flags |= TP_FLAG_TRACE; |
41a7dd42 | 198 | } else |
c31ffb3f | 199 | tk->tp.flags |= TP_FLAG_PROFILE; |
41a7dd42 | 200 | |
c31ffb3f NK |
201 | if (trace_probe_is_registered(&tk->tp) && !trace_kprobe_has_gone(tk)) { |
202 | if (trace_kprobe_is_return(tk)) | |
203 | ret = enable_kretprobe(&tk->rp); | |
1538f888 | 204 | else |
c31ffb3f | 205 | ret = enable_kprobe(&tk->rp.kp); |
1538f888 | 206 | } |
3fe3d619 | 207 | out: |
1538f888 MH |
208 | return ret; |
209 | } | |
210 | ||
b04d52e3 ON |
211 | static struct event_file_link * |
212 | find_event_file_link(struct trace_probe *tp, struct ftrace_event_file *file) | |
41a7dd42 | 213 | { |
b04d52e3 | 214 | struct event_file_link *link; |
41a7dd42 | 215 | |
b04d52e3 ON |
216 | list_for_each_entry(link, &tp->files, list) |
217 | if (link->file == file) | |
218 | return link; | |
41a7dd42 | 219 | |
b04d52e3 | 220 | return NULL; |
41a7dd42 MH |
221 | } |
222 | ||
223 | /* | |
224 | * Disable trace_probe | |
225 | * if the file is NULL, disable "perf" handler, or disable "trace" handler. | |
226 | */ | |
227 | static int | |
c31ffb3f | 228 | disable_trace_kprobe(struct trace_kprobe *tk, struct ftrace_event_file *file) |
1538f888 | 229 | { |
a232e270 MH |
230 | struct event_file_link *link = NULL; |
231 | int wait = 0; | |
41a7dd42 MH |
232 | int ret = 0; |
233 | ||
41a7dd42 | 234 | if (file) { |
c31ffb3f | 235 | link = find_event_file_link(&tk->tp, file); |
b04d52e3 | 236 | if (!link) { |
41a7dd42 | 237 | ret = -EINVAL; |
3fe3d619 | 238 | goto out; |
41a7dd42 MH |
239 | } |
240 | ||
b04d52e3 | 241 | list_del_rcu(&link->list); |
a232e270 | 242 | wait = 1; |
c31ffb3f | 243 | if (!list_empty(&tk->tp.files)) |
b04d52e3 | 244 | goto out; |
41a7dd42 | 245 | |
c31ffb3f | 246 | tk->tp.flags &= ~TP_FLAG_TRACE; |
41a7dd42 | 247 | } else |
c31ffb3f | 248 | tk->tp.flags &= ~TP_FLAG_PROFILE; |
41a7dd42 | 249 | |
c31ffb3f NK |
250 | if (!trace_probe_is_enabled(&tk->tp) && trace_probe_is_registered(&tk->tp)) { |
251 | if (trace_kprobe_is_return(tk)) | |
252 | disable_kretprobe(&tk->rp); | |
1538f888 | 253 | else |
c31ffb3f | 254 | disable_kprobe(&tk->rp.kp); |
a232e270 | 255 | wait = 1; |
1538f888 | 256 | } |
3fe3d619 | 257 | out: |
a232e270 MH |
258 | if (wait) { |
259 | /* | |
260 | * Synchronize with kprobe_trace_func/kretprobe_trace_func | |
261 | * to ensure disabled (all running handlers are finished). | |
262 | * This is not only for kfree(), but also the caller, | |
263 | * trace_remove_event_call() supposes it for releasing | |
264 | * event_call related objects, which will be accessed in | |
265 | * the kprobe_trace_func/kretprobe_trace_func. | |
266 | */ | |
267 | synchronize_sched(); | |
268 | kfree(link); /* Ignored if link == NULL */ | |
269 | } | |
270 | ||
41a7dd42 | 271 | return ret; |
1538f888 MH |
272 | } |
273 | ||
61424318 | 274 | /* Internal register function - just handle k*probes and flags */ |
c31ffb3f | 275 | static int __register_trace_kprobe(struct trace_kprobe *tk) |
413d37d1 | 276 | { |
7f6878a3 | 277 | int i, ret; |
61424318 | 278 | |
c31ffb3f | 279 | if (trace_probe_is_registered(&tk->tp)) |
61424318 MH |
280 | return -EINVAL; |
281 | ||
c31ffb3f NK |
282 | for (i = 0; i < tk->tp.nr_args; i++) |
283 | traceprobe_update_arg(&tk->tp.args[i]); | |
7f6878a3 | 284 | |
61424318 | 285 | /* Set/clear disabled flag according to tp->flag */ |
c31ffb3f NK |
286 | if (trace_probe_is_enabled(&tk->tp)) |
287 | tk->rp.kp.flags &= ~KPROBE_FLAG_DISABLED; | |
61424318 | 288 | else |
c31ffb3f | 289 | tk->rp.kp.flags |= KPROBE_FLAG_DISABLED; |
61424318 | 290 | |
c31ffb3f NK |
291 | if (trace_kprobe_is_return(tk)) |
292 | ret = register_kretprobe(&tk->rp); | |
413d37d1 | 293 | else |
c31ffb3f | 294 | ret = register_kprobe(&tk->rp.kp); |
61424318 MH |
295 | |
296 | if (ret == 0) | |
c31ffb3f | 297 | tk->tp.flags |= TP_FLAG_REGISTERED; |
61424318 MH |
298 | else { |
299 | pr_warning("Could not insert probe at %s+%lu: %d\n", | |
c31ffb3f NK |
300 | trace_kprobe_symbol(tk), trace_kprobe_offset(tk), ret); |
301 | if (ret == -ENOENT && trace_kprobe_is_on_module(tk)) { | |
61424318 MH |
302 | pr_warning("This probe might be able to register after" |
303 | "target module is loaded. Continue.\n"); | |
304 | ret = 0; | |
305 | } else if (ret == -EILSEQ) { | |
306 | pr_warning("Probing address(0x%p) is not an " | |
307 | "instruction boundary.\n", | |
c31ffb3f | 308 | tk->rp.kp.addr); |
61424318 MH |
309 | ret = -EINVAL; |
310 | } | |
311 | } | |
312 | ||
313 | return ret; | |
314 | } | |
315 | ||
316 | /* Internal unregister function - just handle k*probes and flags */ | |
c31ffb3f | 317 | static void __unregister_trace_kprobe(struct trace_kprobe *tk) |
61424318 | 318 | { |
c31ffb3f NK |
319 | if (trace_probe_is_registered(&tk->tp)) { |
320 | if (trace_kprobe_is_return(tk)) | |
321 | unregister_kretprobe(&tk->rp); | |
61424318 | 322 | else |
c31ffb3f NK |
323 | unregister_kprobe(&tk->rp.kp); |
324 | tk->tp.flags &= ~TP_FLAG_REGISTERED; | |
61424318 | 325 | /* Cleanup kprobe for reuse */ |
c31ffb3f NK |
326 | if (tk->rp.kp.symbol_name) |
327 | tk->rp.kp.addr = NULL; | |
61424318 MH |
328 | } |
329 | } | |
330 | ||
331 | /* Unregister a trace_probe and probe_event: call with locking probe_lock */ | |
c31ffb3f | 332 | static int unregister_trace_kprobe(struct trace_kprobe *tk) |
61424318 | 333 | { |
02ca1521 | 334 | /* Enabled event can not be unregistered */ |
c31ffb3f | 335 | if (trace_probe_is_enabled(&tk->tp)) |
02ca1521 MH |
336 | return -EBUSY; |
337 | ||
40c32592 | 338 | /* Will fail if probe is being used by ftrace or perf */ |
c31ffb3f | 339 | if (unregister_kprobe_event(tk)) |
40c32592 SRRH |
340 | return -EBUSY; |
341 | ||
c31ffb3f NK |
342 | __unregister_trace_kprobe(tk); |
343 | list_del(&tk->list); | |
02ca1521 MH |
344 | |
345 | return 0; | |
413d37d1 MH |
346 | } |
347 | ||
348 | /* Register a trace_probe and probe_event */ | |
c31ffb3f | 349 | static int register_trace_kprobe(struct trace_kprobe *tk) |
413d37d1 | 350 | { |
c31ffb3f | 351 | struct trace_kprobe *old_tk; |
413d37d1 MH |
352 | int ret; |
353 | ||
354 | mutex_lock(&probe_lock); | |
355 | ||
61424318 | 356 | /* Delete old (same name) event if exist */ |
c31ffb3f NK |
357 | old_tk = find_trace_kprobe(tk->tp.call.name, tk->tp.call.class->system); |
358 | if (old_tk) { | |
359 | ret = unregister_trace_kprobe(old_tk); | |
02ca1521 MH |
360 | if (ret < 0) |
361 | goto end; | |
c31ffb3f | 362 | free_trace_kprobe(old_tk); |
2d5e067e | 363 | } |
61424318 MH |
364 | |
365 | /* Register new event */ | |
c31ffb3f | 366 | ret = register_kprobe_event(tk); |
2d5e067e | 367 | if (ret) { |
426d3107 | 368 | pr_warning("Failed to register probe event(%d)\n", ret); |
2d5e067e MH |
369 | goto end; |
370 | } | |
371 | ||
61424318 | 372 | /* Register k*probe */ |
c31ffb3f | 373 | ret = __register_trace_kprobe(tk); |
61424318 | 374 | if (ret < 0) |
c31ffb3f | 375 | unregister_kprobe_event(tk); |
61424318 | 376 | else |
c31ffb3f | 377 | list_add_tail(&tk->list, &probe_list); |
61424318 | 378 | |
413d37d1 MH |
379 | end: |
380 | mutex_unlock(&probe_lock); | |
381 | return ret; | |
382 | } | |
383 | ||
61424318 | 384 | /* Module notifier call back, checking event on the module */ |
c31ffb3f | 385 | static int trace_kprobe_module_callback(struct notifier_block *nb, |
61424318 MH |
386 | unsigned long val, void *data) |
387 | { | |
388 | struct module *mod = data; | |
c31ffb3f | 389 | struct trace_kprobe *tk; |
61424318 MH |
390 | int ret; |
391 | ||
392 | if (val != MODULE_STATE_COMING) | |
393 | return NOTIFY_DONE; | |
394 | ||
395 | /* Update probes on coming module */ | |
396 | mutex_lock(&probe_lock); | |
c31ffb3f NK |
397 | list_for_each_entry(tk, &probe_list, list) { |
398 | if (trace_kprobe_within_module(tk, mod)) { | |
02ca1521 | 399 | /* Don't need to check busy - this should have gone. */ |
c31ffb3f NK |
400 | __unregister_trace_kprobe(tk); |
401 | ret = __register_trace_kprobe(tk); | |
61424318 MH |
402 | if (ret) |
403 | pr_warning("Failed to re-register probe %s on" | |
404 | "%s: %d\n", | |
c31ffb3f | 405 | tk->tp.call.name, mod->name, ret); |
61424318 MH |
406 | } |
407 | } | |
408 | mutex_unlock(&probe_lock); | |
409 | ||
410 | return NOTIFY_DONE; | |
411 | } | |
412 | ||
c31ffb3f NK |
413 | static struct notifier_block trace_kprobe_module_nb = { |
414 | .notifier_call = trace_kprobe_module_callback, | |
61424318 MH |
415 | .priority = 1 /* Invoked after kprobe module callback */ |
416 | }; | |
417 | ||
c31ffb3f | 418 | static int create_trace_kprobe(int argc, char **argv) |
413d37d1 MH |
419 | { |
420 | /* | |
421 | * Argument syntax: | |
61424318 MH |
422 | * - Add kprobe: p[:[GRP/]EVENT] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS] |
423 | * - Add kretprobe: r[:[GRP/]EVENT] [MOD:]KSYM[+0] [FETCHARGS] | |
413d37d1 | 424 | * Fetch args: |
2e06ff63 MH |
425 | * $retval : fetch return value |
426 | * $stack : fetch stack address | |
427 | * $stackN : fetch Nth of stack (N:0-) | |
413d37d1 MH |
428 | * @ADDR : fetch memory at ADDR (ADDR should be in kernel) |
429 | * @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol) | |
430 | * %REG : fetch register REG | |
93ccae7a | 431 | * Dereferencing memory fetch: |
413d37d1 | 432 | * +|-offs(ARG) : fetch memory at ARG +|- offs address. |
eca0d916 MH |
433 | * Alias name of args: |
434 | * NAME=FETCHARG : set NAME as alias of FETCHARG. | |
93ccae7a MH |
435 | * Type of args: |
436 | * FETCHARG:TYPE : use TYPE instead of unsigned long. | |
413d37d1 | 437 | */ |
c31ffb3f | 438 | struct trace_kprobe *tk; |
413d37d1 | 439 | int i, ret = 0; |
3a6b7666 | 440 | bool is_return = false, is_delete = false; |
93ccae7a | 441 | char *symbol = NULL, *event = NULL, *group = NULL; |
da34634f | 442 | char *arg; |
2fba0c88 | 443 | unsigned long offset = 0; |
413d37d1 | 444 | void *addr = NULL; |
4a846b44 | 445 | char buf[MAX_EVENT_NAME_LEN]; |
413d37d1 | 446 | |
a7c312be | 447 | /* argc must be >= 1 */ |
413d37d1 | 448 | if (argv[0][0] == 'p') |
3a6b7666 | 449 | is_return = false; |
413d37d1 | 450 | else if (argv[0][0] == 'r') |
3a6b7666 | 451 | is_return = true; |
a7c312be | 452 | else if (argv[0][0] == '-') |
3a6b7666 | 453 | is_delete = true; |
e63cc239 | 454 | else { |
a7c312be MH |
455 | pr_info("Probe definition must be started with 'p', 'r' or" |
456 | " '-'.\n"); | |
413d37d1 | 457 | return -EINVAL; |
e63cc239 | 458 | } |
413d37d1 MH |
459 | |
460 | if (argv[0][1] == ':') { | |
461 | event = &argv[0][2]; | |
f52487e9 MH |
462 | if (strchr(event, '/')) { |
463 | group = event; | |
464 | event = strchr(group, '/') + 1; | |
465 | event[-1] = '\0'; | |
466 | if (strlen(group) == 0) { | |
a5efd925 | 467 | pr_info("Group name is not specified\n"); |
f52487e9 MH |
468 | return -EINVAL; |
469 | } | |
470 | } | |
413d37d1 | 471 | if (strlen(event) == 0) { |
a5efd925 | 472 | pr_info("Event name is not specified\n"); |
413d37d1 MH |
473 | return -EINVAL; |
474 | } | |
475 | } | |
a7c312be MH |
476 | if (!group) |
477 | group = KPROBE_EVENT_SYSTEM; | |
413d37d1 | 478 | |
a7c312be MH |
479 | if (is_delete) { |
480 | if (!event) { | |
481 | pr_info("Delete command needs an event name.\n"); | |
482 | return -EINVAL; | |
483 | } | |
9da79ab8 | 484 | mutex_lock(&probe_lock); |
c31ffb3f NK |
485 | tk = find_trace_kprobe(event, group); |
486 | if (!tk) { | |
9da79ab8 | 487 | mutex_unlock(&probe_lock); |
a7c312be MH |
488 | pr_info("Event %s/%s doesn't exist.\n", group, event); |
489 | return -ENOENT; | |
490 | } | |
491 | /* delete an event */ | |
c31ffb3f | 492 | ret = unregister_trace_kprobe(tk); |
02ca1521 | 493 | if (ret == 0) |
c31ffb3f | 494 | free_trace_kprobe(tk); |
9da79ab8 | 495 | mutex_unlock(&probe_lock); |
02ca1521 | 496 | return ret; |
a7c312be MH |
497 | } |
498 | ||
499 | if (argc < 2) { | |
500 | pr_info("Probe point is not specified.\n"); | |
501 | return -EINVAL; | |
502 | } | |
413d37d1 | 503 | if (isdigit(argv[1][0])) { |
e63cc239 MH |
504 | if (is_return) { |
505 | pr_info("Return probe point must be a symbol.\n"); | |
413d37d1 | 506 | return -EINVAL; |
e63cc239 | 507 | } |
413d37d1 | 508 | /* an address specified */ |
bcd83ea6 | 509 | ret = kstrtoul(&argv[1][0], 0, (unsigned long *)&addr); |
e63cc239 MH |
510 | if (ret) { |
511 | pr_info("Failed to parse address.\n"); | |
413d37d1 | 512 | return ret; |
e63cc239 | 513 | } |
413d37d1 MH |
514 | } else { |
515 | /* a symbol specified */ | |
516 | symbol = argv[1]; | |
517 | /* TODO: support .init module functions */ | |
8ab83f56 | 518 | ret = traceprobe_split_symbol_offset(symbol, &offset); |
e63cc239 MH |
519 | if (ret) { |
520 | pr_info("Failed to parse symbol.\n"); | |
413d37d1 | 521 | return ret; |
e63cc239 MH |
522 | } |
523 | if (offset && is_return) { | |
524 | pr_info("Return probe must be used without offset.\n"); | |
413d37d1 | 525 | return -EINVAL; |
e63cc239 | 526 | } |
413d37d1 | 527 | } |
a82378d8 | 528 | argc -= 2; argv += 2; |
413d37d1 MH |
529 | |
530 | /* setup a probe */ | |
4263565d MH |
531 | if (!event) { |
532 | /* Make a new event name */ | |
4263565d | 533 | if (symbol) |
6f3cf440 | 534 | snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld", |
4263565d MH |
535 | is_return ? 'r' : 'p', symbol, offset); |
536 | else | |
6f3cf440 | 537 | snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p", |
4263565d | 538 | is_return ? 'r' : 'p', addr); |
4a846b44 MH |
539 | event = buf; |
540 | } | |
c31ffb3f | 541 | tk = alloc_trace_kprobe(group, event, addr, symbol, offset, argc, |
f52487e9 | 542 | is_return); |
c31ffb3f | 543 | if (IS_ERR(tk)) { |
e63cc239 | 544 | pr_info("Failed to allocate trace_probe.(%d)\n", |
c31ffb3f NK |
545 | (int)PTR_ERR(tk)); |
546 | return PTR_ERR(tk); | |
e63cc239 | 547 | } |
413d37d1 | 548 | |
413d37d1 | 549 | /* parse arguments */ |
a82378d8 MH |
550 | ret = 0; |
551 | for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) { | |
c31ffb3f NK |
552 | struct probe_arg *parg = &tk->tp.args[i]; |
553 | ||
61a52736 | 554 | /* Increment count for freeing args in error case */ |
c31ffb3f | 555 | tk->tp.nr_args++; |
61a52736 | 556 | |
eca0d916 MH |
557 | /* Parse argument name */ |
558 | arg = strchr(argv[i], '='); | |
aba91595 | 559 | if (arg) { |
eca0d916 | 560 | *arg++ = '\0'; |
c31ffb3f | 561 | parg->name = kstrdup(argv[i], GFP_KERNEL); |
aba91595 | 562 | } else { |
eca0d916 | 563 | arg = argv[i]; |
aba91595 MH |
564 | /* If argument name is omitted, set "argN" */ |
565 | snprintf(buf, MAX_EVENT_NAME_LEN, "arg%d", i + 1); | |
c31ffb3f | 566 | parg->name = kstrdup(buf, GFP_KERNEL); |
aba91595 | 567 | } |
a703d946 | 568 | |
c31ffb3f | 569 | if (!parg->name) { |
aba91595 | 570 | pr_info("Failed to allocate argument[%d] name.\n", i); |
ba8665d7 | 571 | ret = -ENOMEM; |
413d37d1 MH |
572 | goto error; |
573 | } | |
da34634f | 574 | |
c31ffb3f | 575 | if (!is_good_name(parg->name)) { |
da34634f | 576 | pr_info("Invalid argument[%d] name: %s\n", |
c31ffb3f | 577 | i, parg->name); |
da34634f MH |
578 | ret = -EINVAL; |
579 | goto error; | |
580 | } | |
93ccae7a | 581 | |
c31ffb3f NK |
582 | if (traceprobe_conflict_field_name(parg->name, |
583 | tk->tp.args, i)) { | |
aba91595 | 584 | pr_info("Argument[%d] name '%s' conflicts with " |
93ccae7a MH |
585 | "another field.\n", i, argv[i]); |
586 | ret = -EINVAL; | |
587 | goto error; | |
588 | } | |
ba8665d7 MH |
589 | |
590 | /* Parse fetch argument */ | |
c31ffb3f | 591 | ret = traceprobe_parse_probe_arg(arg, &tk->tp.size, parg, |
f3f096cf | 592 | is_return, true); |
e63cc239 | 593 | if (ret) { |
aba91595 | 594 | pr_info("Parse error at argument[%d]. (%d)\n", i, ret); |
413d37d1 | 595 | goto error; |
e63cc239 | 596 | } |
413d37d1 | 597 | } |
413d37d1 | 598 | |
c31ffb3f | 599 | ret = register_trace_kprobe(tk); |
413d37d1 MH |
600 | if (ret) |
601 | goto error; | |
602 | return 0; | |
603 | ||
604 | error: | |
c31ffb3f | 605 | free_trace_kprobe(tk); |
413d37d1 MH |
606 | return ret; |
607 | } | |
608 | ||
c31ffb3f | 609 | static int release_all_trace_kprobes(void) |
413d37d1 | 610 | { |
c31ffb3f | 611 | struct trace_kprobe *tk; |
02ca1521 | 612 | int ret = 0; |
413d37d1 MH |
613 | |
614 | mutex_lock(&probe_lock); | |
02ca1521 | 615 | /* Ensure no probe is in use. */ |
c31ffb3f NK |
616 | list_for_each_entry(tk, &probe_list, list) |
617 | if (trace_probe_is_enabled(&tk->tp)) { | |
02ca1521 MH |
618 | ret = -EBUSY; |
619 | goto end; | |
620 | } | |
413d37d1 MH |
621 | /* TODO: Use batch unregistration */ |
622 | while (!list_empty(&probe_list)) { | |
c31ffb3f NK |
623 | tk = list_entry(probe_list.next, struct trace_kprobe, list); |
624 | ret = unregister_trace_kprobe(tk); | |
40c32592 SRRH |
625 | if (ret) |
626 | goto end; | |
c31ffb3f | 627 | free_trace_kprobe(tk); |
413d37d1 | 628 | } |
02ca1521 MH |
629 | |
630 | end: | |
413d37d1 | 631 | mutex_unlock(&probe_lock); |
02ca1521 MH |
632 | |
633 | return ret; | |
413d37d1 MH |
634 | } |
635 | ||
413d37d1 MH |
636 | /* Probes listing interfaces */ |
637 | static void *probes_seq_start(struct seq_file *m, loff_t *pos) | |
638 | { | |
639 | mutex_lock(&probe_lock); | |
640 | return seq_list_start(&probe_list, *pos); | |
641 | } | |
642 | ||
643 | static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos) | |
644 | { | |
645 | return seq_list_next(v, &probe_list, pos); | |
646 | } | |
647 | ||
648 | static void probes_seq_stop(struct seq_file *m, void *v) | |
649 | { | |
650 | mutex_unlock(&probe_lock); | |
651 | } | |
652 | ||
653 | static int probes_seq_show(struct seq_file *m, void *v) | |
654 | { | |
c31ffb3f | 655 | struct trace_kprobe *tk = v; |
93ccae7a | 656 | int i; |
413d37d1 | 657 | |
c31ffb3f NK |
658 | seq_printf(m, "%c", trace_kprobe_is_return(tk) ? 'r' : 'p'); |
659 | seq_printf(m, ":%s/%s", tk->tp.call.class->system, tk->tp.call.name); | |
413d37d1 | 660 | |
c31ffb3f NK |
661 | if (!tk->symbol) |
662 | seq_printf(m, " 0x%p", tk->rp.kp.addr); | |
663 | else if (tk->rp.kp.offset) | |
664 | seq_printf(m, " %s+%u", trace_kprobe_symbol(tk), | |
665 | tk->rp.kp.offset); | |
413d37d1 | 666 | else |
c31ffb3f | 667 | seq_printf(m, " %s", trace_kprobe_symbol(tk)); |
413d37d1 | 668 | |
c31ffb3f NK |
669 | for (i = 0; i < tk->tp.nr_args; i++) |
670 | seq_printf(m, " %s=%s", tk->tp.args[i].name, tk->tp.args[i].comm); | |
413d37d1 | 671 | seq_printf(m, "\n"); |
93ccae7a | 672 | |
413d37d1 MH |
673 | return 0; |
674 | } | |
675 | ||
676 | static const struct seq_operations probes_seq_op = { | |
677 | .start = probes_seq_start, | |
678 | .next = probes_seq_next, | |
679 | .stop = probes_seq_stop, | |
680 | .show = probes_seq_show | |
681 | }; | |
682 | ||
683 | static int probes_open(struct inode *inode, struct file *file) | |
684 | { | |
02ca1521 MH |
685 | int ret; |
686 | ||
687 | if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { | |
c31ffb3f | 688 | ret = release_all_trace_kprobes(); |
02ca1521 MH |
689 | if (ret < 0) |
690 | return ret; | |
691 | } | |
413d37d1 MH |
692 | |
693 | return seq_open(file, &probes_seq_op); | |
694 | } | |
695 | ||
413d37d1 MH |
696 | static ssize_t probes_write(struct file *file, const char __user *buffer, |
697 | size_t count, loff_t *ppos) | |
698 | { | |
8ab83f56 | 699 | return traceprobe_probes_write(file, buffer, count, ppos, |
c31ffb3f | 700 | create_trace_kprobe); |
413d37d1 MH |
701 | } |
702 | ||
703 | static const struct file_operations kprobe_events_ops = { | |
704 | .owner = THIS_MODULE, | |
705 | .open = probes_open, | |
706 | .read = seq_read, | |
707 | .llseek = seq_lseek, | |
708 | .release = seq_release, | |
709 | .write = probes_write, | |
710 | }; | |
711 | ||
cd7e7bd5 MH |
712 | /* Probes profiling interfaces */ |
713 | static int probes_profile_seq_show(struct seq_file *m, void *v) | |
714 | { | |
c31ffb3f | 715 | struct trace_kprobe *tk = v; |
cd7e7bd5 | 716 | |
c31ffb3f NK |
717 | seq_printf(m, " %-44s %15lu %15lu\n", tk->tp.call.name, tk->nhit, |
718 | tk->rp.kp.nmissed); | |
cd7e7bd5 MH |
719 | |
720 | return 0; | |
721 | } | |
722 | ||
723 | static const struct seq_operations profile_seq_op = { | |
724 | .start = probes_seq_start, | |
725 | .next = probes_seq_next, | |
726 | .stop = probes_seq_stop, | |
727 | .show = probes_profile_seq_show | |
728 | }; | |
729 | ||
730 | static int profile_open(struct inode *inode, struct file *file) | |
731 | { | |
732 | return seq_open(file, &profile_seq_op); | |
733 | } | |
734 | ||
735 | static const struct file_operations kprobe_profile_ops = { | |
736 | .owner = THIS_MODULE, | |
737 | .open = profile_open, | |
738 | .read = seq_read, | |
739 | .llseek = seq_lseek, | |
740 | .release = seq_release, | |
741 | }; | |
742 | ||
413d37d1 | 743 | /* Kprobe handler */ |
2b106aab | 744 | static __kprobes void |
c31ffb3f | 745 | __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs, |
41a7dd42 | 746 | struct ftrace_event_file *ftrace_file) |
413d37d1 | 747 | { |
93ccae7a | 748 | struct kprobe_trace_entry_head *entry; |
413d37d1 | 749 | struct ring_buffer_event *event; |
8f8ffe24 | 750 | struct ring_buffer *buffer; |
e09c8614 | 751 | int size, dsize, pc; |
413d37d1 | 752 | unsigned long irq_flags; |
c31ffb3f | 753 | struct ftrace_event_call *call = &tk->tp.call; |
413d37d1 | 754 | |
41a7dd42 MH |
755 | WARN_ON(call != ftrace_file->event_call); |
756 | ||
b8820084 MH |
757 | if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags)) |
758 | return; | |
759 | ||
413d37d1 MH |
760 | local_save_flags(irq_flags); |
761 | pc = preempt_count(); | |
762 | ||
c31ffb3f NK |
763 | dsize = __get_data_size(&tk->tp, regs); |
764 | size = sizeof(*entry) + tk->tp.size + dsize; | |
413d37d1 | 765 | |
41a7dd42 MH |
766 | event = trace_event_buffer_lock_reserve(&buffer, ftrace_file, |
767 | call->event.type, | |
768 | size, irq_flags, pc); | |
413d37d1 | 769 | if (!event) |
1e12a4a7 | 770 | return; |
413d37d1 MH |
771 | |
772 | entry = ring_buffer_event_data(event); | |
c31ffb3f NK |
773 | entry->ip = (unsigned long)tk->rp.kp.addr; |
774 | store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize); | |
413d37d1 | 775 | |
f306cc82 | 776 | if (!filter_check_discard(ftrace_file, entry, buffer, event)) |
0d5c6e1c SR |
777 | trace_buffer_unlock_commit_regs(buffer, event, |
778 | irq_flags, pc, regs); | |
413d37d1 MH |
779 | } |
780 | ||
41a7dd42 | 781 | static __kprobes void |
c31ffb3f | 782 | kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs) |
41a7dd42 | 783 | { |
b04d52e3 | 784 | struct event_file_link *link; |
41a7dd42 | 785 | |
c31ffb3f NK |
786 | list_for_each_entry_rcu(link, &tk->tp.files, list) |
787 | __kprobe_trace_func(tk, regs, link->file); | |
41a7dd42 MH |
788 | } |
789 | ||
413d37d1 | 790 | /* Kretprobe handler */ |
2b106aab | 791 | static __kprobes void |
c31ffb3f | 792 | __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, |
41a7dd42 MH |
793 | struct pt_regs *regs, |
794 | struct ftrace_event_file *ftrace_file) | |
413d37d1 | 795 | { |
93ccae7a | 796 | struct kretprobe_trace_entry_head *entry; |
413d37d1 | 797 | struct ring_buffer_event *event; |
8f8ffe24 | 798 | struct ring_buffer *buffer; |
e09c8614 | 799 | int size, pc, dsize; |
413d37d1 | 800 | unsigned long irq_flags; |
c31ffb3f | 801 | struct ftrace_event_call *call = &tk->tp.call; |
413d37d1 | 802 | |
41a7dd42 MH |
803 | WARN_ON(call != ftrace_file->event_call); |
804 | ||
b8820084 MH |
805 | if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags)) |
806 | return; | |
807 | ||
413d37d1 MH |
808 | local_save_flags(irq_flags); |
809 | pc = preempt_count(); | |
810 | ||
c31ffb3f NK |
811 | dsize = __get_data_size(&tk->tp, regs); |
812 | size = sizeof(*entry) + tk->tp.size + dsize; | |
413d37d1 | 813 | |
41a7dd42 MH |
814 | event = trace_event_buffer_lock_reserve(&buffer, ftrace_file, |
815 | call->event.type, | |
816 | size, irq_flags, pc); | |
413d37d1 | 817 | if (!event) |
1e12a4a7 | 818 | return; |
413d37d1 MH |
819 | |
820 | entry = ring_buffer_event_data(event); | |
c31ffb3f | 821 | entry->func = (unsigned long)tk->rp.kp.addr; |
413d37d1 | 822 | entry->ret_ip = (unsigned long)ri->ret_addr; |
c31ffb3f | 823 | store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize); |
413d37d1 | 824 | |
f306cc82 | 825 | if (!filter_check_discard(ftrace_file, entry, buffer, event)) |
0d5c6e1c SR |
826 | trace_buffer_unlock_commit_regs(buffer, event, |
827 | irq_flags, pc, regs); | |
413d37d1 MH |
828 | } |
829 | ||
41a7dd42 | 830 | static __kprobes void |
c31ffb3f | 831 | kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, |
41a7dd42 MH |
832 | struct pt_regs *regs) |
833 | { | |
b04d52e3 | 834 | struct event_file_link *link; |
41a7dd42 | 835 | |
c31ffb3f NK |
836 | list_for_each_entry_rcu(link, &tk->tp.files, list) |
837 | __kretprobe_trace_func(tk, ri, regs, link->file); | |
41a7dd42 MH |
838 | } |
839 | ||
413d37d1 | 840 | /* Event entry printers */ |
b62fdd97 | 841 | static enum print_line_t |
a9a57763 SR |
842 | print_kprobe_event(struct trace_iterator *iter, int flags, |
843 | struct trace_event *event) | |
413d37d1 | 844 | { |
93ccae7a | 845 | struct kprobe_trace_entry_head *field; |
413d37d1 | 846 | struct trace_seq *s = &iter->seq; |
eca0d916 | 847 | struct trace_probe *tp; |
93ccae7a | 848 | u8 *data; |
413d37d1 MH |
849 | int i; |
850 | ||
93ccae7a | 851 | field = (struct kprobe_trace_entry_head *)iter->ent; |
80decc70 | 852 | tp = container_of(event, struct trace_probe, call.event); |
413d37d1 | 853 | |
6e9f23d1 MH |
854 | if (!trace_seq_printf(s, "%s: (", tp->call.name)) |
855 | goto partial; | |
856 | ||
413d37d1 MH |
857 | if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET)) |
858 | goto partial; | |
859 | ||
6e9f23d1 | 860 | if (!trace_seq_puts(s, ")")) |
413d37d1 MH |
861 | goto partial; |
862 | ||
93ccae7a MH |
863 | data = (u8 *)&field[1]; |
864 | for (i = 0; i < tp->nr_args; i++) | |
865 | if (!tp->args[i].type->print(s, tp->args[i].name, | |
e09c8614 | 866 | data + tp->args[i].offset, field)) |
413d37d1 MH |
867 | goto partial; |
868 | ||
869 | if (!trace_seq_puts(s, "\n")) | |
870 | goto partial; | |
871 | ||
872 | return TRACE_TYPE_HANDLED; | |
873 | partial: | |
874 | return TRACE_TYPE_PARTIAL_LINE; | |
875 | } | |
876 | ||
b62fdd97 | 877 | static enum print_line_t |
a9a57763 SR |
878 | print_kretprobe_event(struct trace_iterator *iter, int flags, |
879 | struct trace_event *event) | |
413d37d1 | 880 | { |
93ccae7a | 881 | struct kretprobe_trace_entry_head *field; |
413d37d1 | 882 | struct trace_seq *s = &iter->seq; |
eca0d916 | 883 | struct trace_probe *tp; |
93ccae7a | 884 | u8 *data; |
413d37d1 MH |
885 | int i; |
886 | ||
93ccae7a | 887 | field = (struct kretprobe_trace_entry_head *)iter->ent; |
80decc70 | 888 | tp = container_of(event, struct trace_probe, call.event); |
413d37d1 | 889 | |
6e9f23d1 MH |
890 | if (!trace_seq_printf(s, "%s: (", tp->call.name)) |
891 | goto partial; | |
892 | ||
413d37d1 MH |
893 | if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET)) |
894 | goto partial; | |
895 | ||
896 | if (!trace_seq_puts(s, " <- ")) | |
897 | goto partial; | |
898 | ||
899 | if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET)) | |
900 | goto partial; | |
901 | ||
6e9f23d1 | 902 | if (!trace_seq_puts(s, ")")) |
413d37d1 MH |
903 | goto partial; |
904 | ||
93ccae7a MH |
905 | data = (u8 *)&field[1]; |
906 | for (i = 0; i < tp->nr_args; i++) | |
907 | if (!tp->args[i].type->print(s, tp->args[i].name, | |
e09c8614 | 908 | data + tp->args[i].offset, field)) |
413d37d1 MH |
909 | goto partial; |
910 | ||
911 | if (!trace_seq_puts(s, "\n")) | |
912 | goto partial; | |
913 | ||
914 | return TRACE_TYPE_HANDLED; | |
915 | partial: | |
916 | return TRACE_TYPE_PARTIAL_LINE; | |
917 | } | |
918 | ||
413d37d1 MH |
919 | |
920 | static int kprobe_event_define_fields(struct ftrace_event_call *event_call) | |
921 | { | |
922 | int ret, i; | |
93ccae7a | 923 | struct kprobe_trace_entry_head field; |
c31ffb3f | 924 | struct trace_kprobe *tk = (struct trace_kprobe *)event_call->data; |
413d37d1 | 925 | |
a703d946 | 926 | DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0); |
eca0d916 | 927 | /* Set argument names as fields */ |
c31ffb3f NK |
928 | for (i = 0; i < tk->tp.nr_args; i++) { |
929 | struct probe_arg *parg = &tk->tp.args[i]; | |
930 | ||
931 | ret = trace_define_field(event_call, parg->type->fmttype, | |
932 | parg->name, | |
933 | sizeof(field) + parg->offset, | |
934 | parg->type->size, | |
935 | parg->type->is_signed, | |
93ccae7a MH |
936 | FILTER_OTHER); |
937 | if (ret) | |
938 | return ret; | |
939 | } | |
413d37d1 MH |
940 | return 0; |
941 | } | |
942 | ||
943 | static int kretprobe_event_define_fields(struct ftrace_event_call *event_call) | |
944 | { | |
945 | int ret, i; | |
93ccae7a | 946 | struct kretprobe_trace_entry_head field; |
c31ffb3f | 947 | struct trace_kprobe *tk = (struct trace_kprobe *)event_call->data; |
413d37d1 | 948 | |
a703d946 MH |
949 | DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0); |
950 | DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0); | |
eca0d916 | 951 | /* Set argument names as fields */ |
c31ffb3f NK |
952 | for (i = 0; i < tk->tp.nr_args; i++) { |
953 | struct probe_arg *parg = &tk->tp.args[i]; | |
954 | ||
955 | ret = trace_define_field(event_call, parg->type->fmttype, | |
956 | parg->name, | |
957 | sizeof(field) + parg->offset, | |
958 | parg->type->size, | |
959 | parg->type->is_signed, | |
93ccae7a MH |
960 | FILTER_OTHER); |
961 | if (ret) | |
962 | return ret; | |
963 | } | |
413d37d1 MH |
964 | return 0; |
965 | } | |
966 | ||
c31ffb3f | 967 | static int __set_print_fmt(struct trace_kprobe *tk, char *buf, int len) |
a342a028 LJ |
968 | { |
969 | int i; | |
970 | int pos = 0; | |
971 | ||
972 | const char *fmt, *arg; | |
973 | ||
c31ffb3f | 974 | if (!trace_kprobe_is_return(tk)) { |
a342a028 LJ |
975 | fmt = "(%lx)"; |
976 | arg = "REC->" FIELD_STRING_IP; | |
977 | } else { | |
978 | fmt = "(%lx <- %lx)"; | |
979 | arg = "REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP; | |
980 | } | |
981 | ||
982 | /* When len=0, we just calculate the needed length */ | |
983 | #define LEN_OR_ZERO (len ? len - pos : 0) | |
984 | ||
985 | pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt); | |
986 | ||
c31ffb3f | 987 | for (i = 0; i < tk->tp.nr_args; i++) { |
93ccae7a | 988 | pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=%s", |
c31ffb3f | 989 | tk->tp.args[i].name, tk->tp.args[i].type->fmt); |
a342a028 LJ |
990 | } |
991 | ||
992 | pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg); | |
993 | ||
c31ffb3f NK |
994 | for (i = 0; i < tk->tp.nr_args; i++) { |
995 | if (strcmp(tk->tp.args[i].type->name, "string") == 0) | |
e09c8614 MH |
996 | pos += snprintf(buf + pos, LEN_OR_ZERO, |
997 | ", __get_str(%s)", | |
c31ffb3f | 998 | tk->tp.args[i].name); |
e09c8614 MH |
999 | else |
1000 | pos += snprintf(buf + pos, LEN_OR_ZERO, ", REC->%s", | |
c31ffb3f | 1001 | tk->tp.args[i].name); |
a342a028 LJ |
1002 | } |
1003 | ||
1004 | #undef LEN_OR_ZERO | |
1005 | ||
1006 | /* return the length of print_fmt */ | |
1007 | return pos; | |
1008 | } | |
1009 | ||
c31ffb3f | 1010 | static int set_print_fmt(struct trace_kprobe *tk) |
a342a028 LJ |
1011 | { |
1012 | int len; | |
1013 | char *print_fmt; | |
1014 | ||
1015 | /* First: called with 0 length to calculate the needed length */ | |
c31ffb3f | 1016 | len = __set_print_fmt(tk, NULL, 0); |
a342a028 LJ |
1017 | print_fmt = kmalloc(len + 1, GFP_KERNEL); |
1018 | if (!print_fmt) | |
1019 | return -ENOMEM; | |
1020 | ||
1021 | /* Second: actually write the @print_fmt */ | |
c31ffb3f NK |
1022 | __set_print_fmt(tk, print_fmt, len + 1); |
1023 | tk->tp.call.print_fmt = print_fmt; | |
a342a028 LJ |
1024 | |
1025 | return 0; | |
1026 | } | |
1027 | ||
07b139c8 | 1028 | #ifdef CONFIG_PERF_EVENTS |
e08d1c65 MH |
1029 | |
1030 | /* Kprobe profile handler */ | |
2b106aab | 1031 | static __kprobes void |
c31ffb3f | 1032 | kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs) |
e08d1c65 | 1033 | { |
c31ffb3f | 1034 | struct ftrace_event_call *call = &tk->tp.call; |
93ccae7a | 1035 | struct kprobe_trace_entry_head *entry; |
1c024eca | 1036 | struct hlist_head *head; |
e09c8614 | 1037 | int size, __size, dsize; |
4ed7c92d | 1038 | int rctx; |
e08d1c65 | 1039 | |
288e984e ON |
1040 | head = this_cpu_ptr(call->perf_events); |
1041 | if (hlist_empty(head)) | |
1042 | return; | |
1043 | ||
c31ffb3f NK |
1044 | dsize = __get_data_size(&tk->tp, regs); |
1045 | __size = sizeof(*entry) + tk->tp.size + dsize; | |
74ebb63e MH |
1046 | size = ALIGN(__size + sizeof(u32), sizeof(u64)); |
1047 | size -= sizeof(u32); | |
ce71b9df | 1048 | |
ff5f149b | 1049 | entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx); |
430ad5a6 | 1050 | if (!entry) |
1e12a4a7 | 1051 | return; |
a1a138d0 | 1052 | |
c31ffb3f | 1053 | entry->ip = (unsigned long)tk->rp.kp.addr; |
e09c8614 | 1054 | memset(&entry[1], 0, dsize); |
c31ffb3f | 1055 | store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize); |
cf6735a4 | 1056 | perf_trace_buf_submit(entry, size, rctx, 0, 1, regs, head, NULL); |
e08d1c65 MH |
1057 | } |
1058 | ||
1059 | /* Kretprobe profile handler */ | |
2b106aab | 1060 | static __kprobes void |
c31ffb3f | 1061 | kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, |
2b106aab | 1062 | struct pt_regs *regs) |
e08d1c65 | 1063 | { |
c31ffb3f | 1064 | struct ftrace_event_call *call = &tk->tp.call; |
93ccae7a | 1065 | struct kretprobe_trace_entry_head *entry; |
1c024eca | 1066 | struct hlist_head *head; |
e09c8614 | 1067 | int size, __size, dsize; |
4ed7c92d | 1068 | int rctx; |
e08d1c65 | 1069 | |
288e984e ON |
1070 | head = this_cpu_ptr(call->perf_events); |
1071 | if (hlist_empty(head)) | |
1072 | return; | |
1073 | ||
c31ffb3f NK |
1074 | dsize = __get_data_size(&tk->tp, regs); |
1075 | __size = sizeof(*entry) + tk->tp.size + dsize; | |
74ebb63e MH |
1076 | size = ALIGN(__size + sizeof(u32), sizeof(u64)); |
1077 | size -= sizeof(u32); | |
444a2a3b | 1078 | |
ff5f149b | 1079 | entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx); |
430ad5a6 | 1080 | if (!entry) |
1e12a4a7 | 1081 | return; |
e08d1c65 | 1082 | |
c31ffb3f | 1083 | entry->func = (unsigned long)tk->rp.kp.addr; |
a1a138d0 | 1084 | entry->ret_ip = (unsigned long)ri->ret_addr; |
c31ffb3f | 1085 | store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize); |
cf6735a4 | 1086 | perf_trace_buf_submit(entry, size, rctx, 0, 1, regs, head, NULL); |
e08d1c65 | 1087 | } |
07b139c8 | 1088 | #endif /* CONFIG_PERF_EVENTS */ |
50d78056 | 1089 | |
3fe3d619 ON |
1090 | /* |
1091 | * called by perf_trace_init() or __ftrace_set_clr_event() under event_mutex. | |
1092 | * | |
1093 | * kprobe_trace_self_tests_init() does enable_trace_probe/disable_trace_probe | |
1094 | * lockless, but we can't race with this __init function. | |
1095 | */ | |
2239291a | 1096 | static __kprobes |
ceec0b6f JO |
1097 | int kprobe_register(struct ftrace_event_call *event, |
1098 | enum trace_reg type, void *data) | |
2239291a | 1099 | { |
c31ffb3f | 1100 | struct trace_kprobe *tk = (struct trace_kprobe *)event->data; |
41a7dd42 | 1101 | struct ftrace_event_file *file = data; |
1538f888 | 1102 | |
2239291a SR |
1103 | switch (type) { |
1104 | case TRACE_REG_REGISTER: | |
c31ffb3f | 1105 | return enable_trace_kprobe(tk, file); |
2239291a | 1106 | case TRACE_REG_UNREGISTER: |
c31ffb3f | 1107 | return disable_trace_kprobe(tk, file); |
2239291a SR |
1108 | |
1109 | #ifdef CONFIG_PERF_EVENTS | |
1110 | case TRACE_REG_PERF_REGISTER: | |
c31ffb3f | 1111 | return enable_trace_kprobe(tk, NULL); |
2239291a | 1112 | case TRACE_REG_PERF_UNREGISTER: |
c31ffb3f | 1113 | return disable_trace_kprobe(tk, NULL); |
ceec0b6f JO |
1114 | case TRACE_REG_PERF_OPEN: |
1115 | case TRACE_REG_PERF_CLOSE: | |
489c75c3 JO |
1116 | case TRACE_REG_PERF_ADD: |
1117 | case TRACE_REG_PERF_DEL: | |
ceec0b6f | 1118 | return 0; |
2239291a SR |
1119 | #endif |
1120 | } | |
1121 | return 0; | |
1122 | } | |
50d78056 MH |
1123 | |
1124 | static __kprobes | |
1125 | int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs) | |
1126 | { | |
c31ffb3f | 1127 | struct trace_kprobe *tk = container_of(kp, struct trace_kprobe, rp.kp); |
e08d1c65 | 1128 | |
c31ffb3f | 1129 | tk->nhit++; |
48182bd2 | 1130 | |
c31ffb3f NK |
1131 | if (tk->tp.flags & TP_FLAG_TRACE) |
1132 | kprobe_trace_func(tk, regs); | |
07b139c8 | 1133 | #ifdef CONFIG_PERF_EVENTS |
c31ffb3f NK |
1134 | if (tk->tp.flags & TP_FLAG_PROFILE) |
1135 | kprobe_perf_func(tk, regs); | |
07b139c8 | 1136 | #endif |
50d78056 MH |
1137 | return 0; /* We don't tweek kernel, so just return 0 */ |
1138 | } | |
1139 | ||
1140 | static __kprobes | |
1141 | int kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs) | |
1142 | { | |
c31ffb3f | 1143 | struct trace_kprobe *tk = container_of(ri->rp, struct trace_kprobe, rp); |
50d78056 | 1144 | |
c31ffb3f | 1145 | tk->nhit++; |
48182bd2 | 1146 | |
c31ffb3f NK |
1147 | if (tk->tp.flags & TP_FLAG_TRACE) |
1148 | kretprobe_trace_func(tk, ri, regs); | |
07b139c8 | 1149 | #ifdef CONFIG_PERF_EVENTS |
c31ffb3f NK |
1150 | if (tk->tp.flags & TP_FLAG_PROFILE) |
1151 | kretprobe_perf_func(tk, ri, regs); | |
07b139c8 | 1152 | #endif |
50d78056 MH |
1153 | return 0; /* We don't tweek kernel, so just return 0 */ |
1154 | } | |
e08d1c65 | 1155 | |
a9a57763 SR |
1156 | static struct trace_event_functions kretprobe_funcs = { |
1157 | .trace = print_kretprobe_event | |
1158 | }; | |
1159 | ||
1160 | static struct trace_event_functions kprobe_funcs = { | |
1161 | .trace = print_kprobe_event | |
1162 | }; | |
1163 | ||
c31ffb3f | 1164 | static int register_kprobe_event(struct trace_kprobe *tk) |
413d37d1 | 1165 | { |
c31ffb3f | 1166 | struct ftrace_event_call *call = &tk->tp.call; |
413d37d1 MH |
1167 | int ret; |
1168 | ||
1169 | /* Initialize ftrace_event_call */ | |
ffb9f995 | 1170 | INIT_LIST_HEAD(&call->class->fields); |
c31ffb3f | 1171 | if (trace_kprobe_is_return(tk)) { |
80decc70 | 1172 | call->event.funcs = &kretprobe_funcs; |
2e33af02 | 1173 | call->class->define_fields = kretprobe_event_define_fields; |
413d37d1 | 1174 | } else { |
80decc70 | 1175 | call->event.funcs = &kprobe_funcs; |
2e33af02 | 1176 | call->class->define_fields = kprobe_event_define_fields; |
413d37d1 | 1177 | } |
c31ffb3f | 1178 | if (set_print_fmt(tk) < 0) |
a342a028 | 1179 | return -ENOMEM; |
32c0edae SR |
1180 | ret = register_ftrace_event(&call->event); |
1181 | if (!ret) { | |
a342a028 | 1182 | kfree(call->print_fmt); |
ff50d991 | 1183 | return -ENODEV; |
a342a028 | 1184 | } |
553552ce | 1185 | call->flags = 0; |
2239291a | 1186 | call->class->reg = kprobe_register; |
c31ffb3f | 1187 | call->data = tk; |
413d37d1 | 1188 | ret = trace_add_event_call(call); |
ff50d991 | 1189 | if (ret) { |
413d37d1 | 1190 | pr_info("Failed to register kprobe event: %s\n", call->name); |
a342a028 | 1191 | kfree(call->print_fmt); |
80decc70 | 1192 | unregister_ftrace_event(&call->event); |
ff50d991 | 1193 | } |
413d37d1 MH |
1194 | return ret; |
1195 | } | |
1196 | ||
c31ffb3f | 1197 | static int unregister_kprobe_event(struct trace_kprobe *tk) |
413d37d1 | 1198 | { |
40c32592 SRRH |
1199 | int ret; |
1200 | ||
ff50d991 | 1201 | /* tp->event is unregistered in trace_remove_event_call() */ |
c31ffb3f | 1202 | ret = trace_remove_event_call(&tk->tp.call); |
40c32592 | 1203 | if (!ret) |
c31ffb3f | 1204 | kfree(tk->tp.call.print_fmt); |
40c32592 | 1205 | return ret; |
413d37d1 MH |
1206 | } |
1207 | ||
25985edc | 1208 | /* Make a debugfs interface for controlling probe points */ |
413d37d1 MH |
1209 | static __init int init_kprobe_trace(void) |
1210 | { | |
1211 | struct dentry *d_tracer; | |
1212 | struct dentry *entry; | |
413d37d1 | 1213 | |
c31ffb3f | 1214 | if (register_module_notifier(&trace_kprobe_module_nb)) |
61424318 MH |
1215 | return -EINVAL; |
1216 | ||
413d37d1 MH |
1217 | d_tracer = tracing_init_dentry(); |
1218 | if (!d_tracer) | |
1219 | return 0; | |
1220 | ||
1221 | entry = debugfs_create_file("kprobe_events", 0644, d_tracer, | |
1222 | NULL, &kprobe_events_ops); | |
1223 | ||
cd7e7bd5 | 1224 | /* Event list interface */ |
413d37d1 MH |
1225 | if (!entry) |
1226 | pr_warning("Could not create debugfs " | |
1227 | "'kprobe_events' entry\n"); | |
cd7e7bd5 MH |
1228 | |
1229 | /* Profile interface */ | |
1230 | entry = debugfs_create_file("kprobe_profile", 0444, d_tracer, | |
1231 | NULL, &kprobe_profile_ops); | |
1232 | ||
1233 | if (!entry) | |
1234 | pr_warning("Could not create debugfs " | |
1235 | "'kprobe_profile' entry\n"); | |
413d37d1 MH |
1236 | return 0; |
1237 | } | |
1238 | fs_initcall(init_kprobe_trace); | |
1239 | ||
1240 | ||
1241 | #ifdef CONFIG_FTRACE_STARTUP_TEST | |
1242 | ||
265a5b7e SR |
1243 | /* |
1244 | * The "__used" keeps gcc from removing the function symbol | |
1245 | * from the kallsyms table. | |
1246 | */ | |
1247 | static __used int kprobe_trace_selftest_target(int a1, int a2, int a3, | |
1248 | int a4, int a5, int a6) | |
413d37d1 MH |
1249 | { |
1250 | return a1 + a2 + a3 + a4 + a5 + a6; | |
1251 | } | |
1252 | ||
41a7dd42 | 1253 | static struct ftrace_event_file * |
c31ffb3f | 1254 | find_trace_probe_file(struct trace_kprobe *tk, struct trace_array *tr) |
41a7dd42 MH |
1255 | { |
1256 | struct ftrace_event_file *file; | |
1257 | ||
1258 | list_for_each_entry(file, &tr->events, list) | |
c31ffb3f | 1259 | if (file->event_call == &tk->tp.call) |
41a7dd42 MH |
1260 | return file; |
1261 | ||
1262 | return NULL; | |
1263 | } | |
1264 | ||
3fe3d619 | 1265 | /* |
c31ffb3f | 1266 | * Nobody but us can call enable_trace_kprobe/disable_trace_kprobe at this |
3fe3d619 ON |
1267 | * stage, we can do this lockless. |
1268 | */ | |
413d37d1 MH |
1269 | static __init int kprobe_trace_self_tests_init(void) |
1270 | { | |
231e36f4 | 1271 | int ret, warn = 0; |
413d37d1 | 1272 | int (*target)(int, int, int, int, int, int); |
c31ffb3f | 1273 | struct trace_kprobe *tk; |
41a7dd42 | 1274 | struct ftrace_event_file *file; |
413d37d1 MH |
1275 | |
1276 | target = kprobe_trace_selftest_target; | |
1277 | ||
1278 | pr_info("Testing kprobe tracing: "); | |
1279 | ||
8ab83f56 SD |
1280 | ret = traceprobe_command("p:testprobe kprobe_trace_selftest_target " |
1281 | "$stack $stack0 +0($stack)", | |
c31ffb3f | 1282 | create_trace_kprobe); |
231e36f4 | 1283 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 1284 | pr_warn("error on probing function entry.\n"); |
231e36f4 MH |
1285 | warn++; |
1286 | } else { | |
1287 | /* Enable trace point */ | |
c31ffb3f NK |
1288 | tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM); |
1289 | if (WARN_ON_ONCE(tk == NULL)) { | |
41a7dd42 | 1290 | pr_warn("error on getting new probe.\n"); |
231e36f4 | 1291 | warn++; |
41a7dd42 | 1292 | } else { |
c31ffb3f | 1293 | file = find_trace_probe_file(tk, top_trace_array()); |
41a7dd42 MH |
1294 | if (WARN_ON_ONCE(file == NULL)) { |
1295 | pr_warn("error on getting probe file.\n"); | |
1296 | warn++; | |
1297 | } else | |
c31ffb3f | 1298 | enable_trace_kprobe(tk, file); |
41a7dd42 | 1299 | } |
231e36f4 | 1300 | } |
413d37d1 | 1301 | |
8ab83f56 | 1302 | ret = traceprobe_command("r:testprobe2 kprobe_trace_selftest_target " |
c31ffb3f | 1303 | "$retval", create_trace_kprobe); |
231e36f4 | 1304 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 1305 | pr_warn("error on probing function return.\n"); |
231e36f4 MH |
1306 | warn++; |
1307 | } else { | |
1308 | /* Enable trace point */ | |
c31ffb3f NK |
1309 | tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM); |
1310 | if (WARN_ON_ONCE(tk == NULL)) { | |
41a7dd42 | 1311 | pr_warn("error on getting 2nd new probe.\n"); |
231e36f4 | 1312 | warn++; |
41a7dd42 | 1313 | } else { |
c31ffb3f | 1314 | file = find_trace_probe_file(tk, top_trace_array()); |
41a7dd42 MH |
1315 | if (WARN_ON_ONCE(file == NULL)) { |
1316 | pr_warn("error on getting probe file.\n"); | |
1317 | warn++; | |
1318 | } else | |
c31ffb3f | 1319 | enable_trace_kprobe(tk, file); |
41a7dd42 | 1320 | } |
231e36f4 MH |
1321 | } |
1322 | ||
1323 | if (warn) | |
1324 | goto end; | |
413d37d1 MH |
1325 | |
1326 | ret = target(1, 2, 3, 4, 5, 6); | |
1327 | ||
02ca1521 | 1328 | /* Disable trace points before removing it */ |
c31ffb3f NK |
1329 | tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM); |
1330 | if (WARN_ON_ONCE(tk == NULL)) { | |
41a7dd42 | 1331 | pr_warn("error on getting test probe.\n"); |
02ca1521 | 1332 | warn++; |
41a7dd42 | 1333 | } else { |
c31ffb3f | 1334 | file = find_trace_probe_file(tk, top_trace_array()); |
41a7dd42 MH |
1335 | if (WARN_ON_ONCE(file == NULL)) { |
1336 | pr_warn("error on getting probe file.\n"); | |
1337 | warn++; | |
1338 | } else | |
c31ffb3f | 1339 | disable_trace_kprobe(tk, file); |
41a7dd42 | 1340 | } |
02ca1521 | 1341 | |
c31ffb3f NK |
1342 | tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM); |
1343 | if (WARN_ON_ONCE(tk == NULL)) { | |
41a7dd42 | 1344 | pr_warn("error on getting 2nd test probe.\n"); |
02ca1521 | 1345 | warn++; |
41a7dd42 | 1346 | } else { |
c31ffb3f | 1347 | file = find_trace_probe_file(tk, top_trace_array()); |
41a7dd42 MH |
1348 | if (WARN_ON_ONCE(file == NULL)) { |
1349 | pr_warn("error on getting probe file.\n"); | |
1350 | warn++; | |
1351 | } else | |
c31ffb3f | 1352 | disable_trace_kprobe(tk, file); |
41a7dd42 | 1353 | } |
02ca1521 | 1354 | |
c31ffb3f | 1355 | ret = traceprobe_command("-:testprobe", create_trace_kprobe); |
231e36f4 | 1356 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 1357 | pr_warn("error on deleting a probe.\n"); |
231e36f4 MH |
1358 | warn++; |
1359 | } | |
1360 | ||
c31ffb3f | 1361 | ret = traceprobe_command("-:testprobe2", create_trace_kprobe); |
231e36f4 | 1362 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 1363 | pr_warn("error on deleting a probe.\n"); |
231e36f4 MH |
1364 | warn++; |
1365 | } | |
413d37d1 | 1366 | |
231e36f4 | 1367 | end: |
c31ffb3f | 1368 | release_all_trace_kprobes(); |
231e36f4 MH |
1369 | if (warn) |
1370 | pr_cont("NG: Some tests are failed. Please check them.\n"); | |
1371 | else | |
1372 | pr_cont("OK\n"); | |
413d37d1 MH |
1373 | return 0; |
1374 | } | |
1375 | ||
1376 | late_initcall(kprobe_trace_self_tests_init); | |
1377 | ||
1378 | #endif |