Commit | Line | Data |
---|---|---|
ae3dd5f0 MD |
1 | /* |
2 | * probes/lttng-probe-sched.c | |
3 | * | |
4 | * Copyright 2010 (c) - Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
5 | * | |
6 | * LTTng sched probes. | |
17baffe2 MD |
7 | * |
8 | * Dual LGPL v2.1/GPL v2 license. | |
ae3dd5f0 MD |
9 | */ |
10 | ||
11 | #include <linux/module.h> | |
1ec65de1 | 12 | #include "../ltt-events.h" |
ae3dd5f0 | 13 | |
054f2ed3 MD |
14 | #ifndef SYSCALL_DETAIL |
15 | ||
ae3dd5f0 MD |
16 | /* |
17 | * Create the tracepoint static inlines from the kernel to validate that our | |
18 | * trace event macros match the kernel we run on. | |
19 | */ | |
705e0807 | 20 | #include <trace/events/syscalls.h> |
ae3dd5f0 MD |
21 | |
22 | /* | |
23 | * Create LTTng tracepoint probes. | |
24 | */ | |
25 | #define LTTNG_PACKAGE_BUILD | |
26 | #define CREATE_TRACE_POINTS | |
d5869321 | 27 | #define TRACE_INCLUDE_PATH ../instrumentation/events/lttng-module |
ae3dd5f0 | 28 | |
d5869321 | 29 | #include "../instrumentation/events/lttng-module/syscalls.h" |
ae3dd5f0 | 30 | |
054f2ed3 MD |
31 | #else /* SYSCALL_DETAIL */ |
32 | ||
1ec65de1 MD |
33 | #include <linux/slab.h> |
34 | #include <asm/ptrace.h> | |
35 | #include <asm/syscall.h> | |
36 | ||
37 | static void syscall_entry_probe(void *__data, struct pt_regs *regs, long id); | |
38 | static int lttng_syscalls_register_probe(struct lttng_probe_desc *desc); | |
39 | static void lttng_syscalls_unregister_probe(struct lttng_probe_desc *desc); | |
40 | ||
41 | static struct lttng_probe_desc *syscall_probe_desc; | |
42 | ||
054f2ed3 MD |
43 | /* |
44 | * Create LTTng tracepoint probes. | |
45 | */ | |
46 | #define LTTNG_PACKAGE_BUILD | |
47 | #define CREATE_TRACE_POINTS | |
48 | ||
1ec65de1 MD |
49 | /* Hijack probe callback for system calls */ |
50 | #define TP_PROBE_CB(_template) &syscall_entry_probe | |
51 | #define TP_REGISTER_OVERRIDE lttng_syscalls_register_probe | |
52 | #define TP_UNREGISTER_OVERRIDE lttng_syscalls_unregister_probe | |
054f2ed3 | 53 | |
1ec65de1 | 54 | #define TRACE_INCLUDE_PATH ../instrumentation/syscalls/headers |
054f2ed3 MD |
55 | |
56 | #include "../instrumentation/syscalls/headers/syscalls.h" | |
57 | ||
1ec65de1 MD |
58 | #undef TP_UNREGISTER_OVERRIDE |
59 | #undef TP_REGISTER_OVERRIDE | |
60 | #undef TP_PROBE_CB | |
054f2ed3 MD |
61 | #undef LTTNG_PACKAGE_BUILD |
62 | #undef CREATE_TRACE_POINTS | |
63 | ||
64 | struct trace_syscall_entry { | |
65 | void *func; | |
1ec65de1 MD |
66 | const struct lttng_event_desc *desc; /* Set dynamically */ |
67 | const struct lttng_event_field *fields; | |
054f2ed3 MD |
68 | unsigned int nrargs; |
69 | }; | |
70 | ||
1ec65de1 MD |
71 | static int sc_table_desc_filled; |
72 | ||
054f2ed3 MD |
73 | #define CREATE_SYSCALL_TABLE |
74 | ||
75 | #undef TRACE_SYSCALL_TABLE | |
1ec65de1 MD |
76 | #define TRACE_SYSCALL_TABLE(_name, _nr, _nrargs) \ |
77 | [ _nr ] = { \ | |
78 | .func = __event_probe__##_name, \ | |
79 | .nrargs = (_nrargs), \ | |
80 | .fields = __event_fields___##_name, \ | |
81 | }, | |
054f2ed3 MD |
82 | |
83 | static struct trace_syscall_entry sc_table[] = { | |
84 | #include "../instrumentation/syscalls/headers/syscalls.h" | |
85 | }; | |
1ec65de1 | 86 | |
054f2ed3 MD |
87 | #undef CREATE_SYSCALL_TABLE |
88 | ||
1ec65de1 MD |
89 | static void syscall_entry_probe(void *__data, struct pt_regs *regs, long id) |
90 | { | |
91 | struct trace_syscall_entry *entry; | |
92 | struct ltt_channel *chan = __data; | |
93 | struct ltt_event *event; | |
94 | ||
95 | if (unlikely(id >= ARRAY_SIZE(sc_table))) | |
96 | return; | |
97 | entry = &sc_table[id]; | |
98 | if (unlikely(!entry->func)) | |
99 | return; | |
100 | event = chan->sc_table[id]; | |
101 | WARN_ON_ONCE(!event); | |
102 | ||
103 | switch (entry->nrargs) { | |
104 | case 0: | |
105 | { | |
106 | void (*fptr)(void *__data) = entry->func; | |
107 | ||
108 | fptr(event); | |
109 | break; | |
110 | } | |
111 | case 1: | |
112 | { | |
113 | void (*fptr)(void *__data, unsigned long arg0) = entry->func; | |
114 | unsigned long args[1]; | |
115 | ||
116 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); | |
117 | fptr(event, args[0]); | |
118 | break; | |
119 | } | |
120 | case 2: | |
121 | { | |
122 | void (*fptr)(void *__data, | |
123 | unsigned long arg0, | |
124 | unsigned long arg1) = entry->func; | |
125 | unsigned long args[2]; | |
126 | ||
127 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); | |
128 | fptr(event, args[0], args[1]); | |
129 | break; | |
130 | } | |
131 | case 3: | |
132 | { | |
133 | void (*fptr)(void *__data, | |
134 | unsigned long arg0, | |
135 | unsigned long arg1, | |
136 | unsigned long arg2) = entry->func; | |
137 | unsigned long args[3]; | |
138 | ||
139 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); | |
140 | fptr(event, args[0], args[1], args[2]); | |
141 | break; | |
142 | } | |
143 | case 4: | |
144 | { | |
145 | void (*fptr)(void *__data, | |
146 | unsigned long arg0, | |
147 | unsigned long arg1, | |
148 | unsigned long arg2, | |
149 | unsigned long arg3) = entry->func; | |
150 | unsigned long args[4]; | |
151 | ||
152 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); | |
153 | fptr(event, args[0], args[1], args[2], args[3]); | |
154 | break; | |
155 | } | |
156 | case 5: | |
157 | { | |
158 | void (*fptr)(void *__data, | |
159 | unsigned long arg0, | |
160 | unsigned long arg1, | |
161 | unsigned long arg2, | |
162 | unsigned long arg3, | |
163 | unsigned long arg4) = entry->func; | |
164 | unsigned long args[5]; | |
165 | ||
166 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); | |
167 | fptr(event, args[0], args[1], args[2], args[3], args[4]); | |
168 | break; | |
169 | } | |
170 | case 6: | |
171 | { | |
172 | void (*fptr)(void *__data, | |
173 | unsigned long arg0, | |
174 | unsigned long arg1, | |
175 | unsigned long arg2, | |
176 | unsigned long arg3, | |
177 | unsigned long arg4, | |
178 | unsigned long arg5) = entry->func; | |
179 | unsigned long args[6]; | |
180 | ||
181 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); | |
182 | fptr(event, args[0], args[1], args[2], | |
183 | args[3], args[4], args[5]); | |
184 | break; | |
185 | } | |
186 | default: | |
187 | break; | |
188 | } | |
189 | } | |
190 | ||
191 | static const struct lttng_event_desc *find_syscall_desc(unsigned int id) | |
192 | { | |
193 | unsigned int i; | |
194 | ||
195 | for (i = 0; i < syscall_probe_desc->nr_events; i++) { | |
196 | if (syscall_probe_desc->event_desc[i].fields | |
197 | == sc_table[id].fields) | |
198 | return &syscall_probe_desc->event_desc[i]; | |
199 | } | |
200 | WARN_ON_ONCE(1); | |
201 | return NULL; | |
202 | } | |
203 | ||
204 | static void fill_sc_table_desc(void) | |
205 | { | |
206 | unsigned int i; | |
207 | ||
208 | if (sc_table_desc_filled) | |
209 | return; | |
210 | /* | |
211 | * This is O(n^2), but rare. Eventually get the TRACE_EVENT code | |
212 | * to emit per-event symbols to skip this. | |
213 | */ | |
214 | for (i = 0; i < ARRAY_SIZE(sc_table); i++) { | |
215 | const struct lttng_event_desc **desc = &sc_table[i].desc; | |
216 | ||
217 | if (!sc_table[i].func) | |
218 | continue; | |
219 | (*desc) = find_syscall_desc(i); | |
220 | } | |
221 | sc_table_desc_filled = 1; | |
222 | } | |
223 | ||
224 | ||
225 | int lttng_syscalls_register(struct ltt_channel *chan, void *filter) | |
226 | { | |
227 | unsigned int i; | |
228 | int ret; | |
229 | ||
230 | fill_sc_table_desc(); | |
231 | ||
232 | if (!chan->sc_table) { | |
233 | /* create syscall table mapping syscall to events */ | |
234 | chan->sc_table = kzalloc(sizeof(struct ltt_event *) | |
235 | * ARRAY_SIZE(sc_table), GFP_KERNEL); | |
236 | if (!chan->sc_table) | |
237 | return -ENOMEM; | |
238 | } | |
239 | ||
240 | /* Allocate events for each syscall, insert into table */ | |
241 | for (i = 0; i < ARRAY_SIZE(sc_table); i++) { | |
242 | struct lttng_kernel_event ev; | |
243 | const struct lttng_event_desc *desc = sc_table[i].desc; | |
244 | ||
245 | /* | |
246 | * Skip those already populated by previous failed | |
247 | * register for this channel. | |
248 | */ | |
249 | if (chan->sc_table[i]) | |
250 | continue; | |
251 | memset(&ev, 0, sizeof(ev)); | |
252 | strncpy(ev.name, desc->name, LTTNG_SYM_NAME_LEN); | |
253 | ev.name[LTTNG_SYM_NAME_LEN - 1] = '\0'; | |
254 | ev.instrumentation = LTTNG_KERNEL_NOOP; | |
255 | chan->sc_table[i] = ltt_event_create(chan, &ev, filter); | |
256 | if (!chan->sc_table[i]) { | |
257 | /* | |
258 | * If something goes wrong in event registration | |
259 | * after the first one, we have no choice but to | |
260 | * leave the previous events in there, until | |
261 | * deleted by session teardown. | |
262 | */ | |
263 | return -EINVAL; | |
264 | } | |
265 | } | |
266 | ret = tracepoint_probe_register("syscall_entry", | |
267 | (void *) syscall_entry_probe, chan); | |
268 | return ret; | |
269 | } | |
270 | ||
271 | /* | |
272 | * Only called at session destruction. | |
273 | */ | |
274 | int lttng_syscalls_unregister(struct ltt_channel *chan) | |
275 | { | |
276 | int ret; | |
277 | ||
278 | if (!chan->sc_table) | |
279 | return 0; | |
280 | ret = tracepoint_probe_unregister("syscall_entry", | |
281 | (void *) syscall_entry_probe, chan); | |
282 | if (ret) | |
283 | return ret; | |
284 | /* ltt_event destroy will be performed by ltt_session_destroy() */ | |
285 | kfree(chan->sc_table); | |
286 | return 0; | |
287 | } | |
288 | ||
289 | static int lttng_syscalls_register_probe(struct lttng_probe_desc *desc) | |
290 | { | |
291 | WARN_ON_ONCE(syscall_probe_desc); | |
292 | syscall_probe_desc = desc; | |
293 | return 0; | |
294 | } | |
295 | ||
296 | static void lttng_syscalls_unregister_probe(struct lttng_probe_desc *desc) | |
297 | { | |
298 | WARN_ON_ONCE(!syscall_probe_desc); | |
299 | syscall_probe_desc = NULL; | |
300 | } | |
301 | ||
054f2ed3 MD |
302 | #endif /* SYSCALL_DETAIL */ |
303 | ||
ae3dd5f0 MD |
304 | MODULE_LICENSE("GPL and additional rights"); |
305 | MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>"); | |
306 | MODULE_DESCRIPTION("LTTng sched probes"); |