Commit | Line | Data |
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259b6cb3 MD |
1 | /* |
2 | * lttng-syscalls.c | |
3 | * | |
4 | * Copyright 2010 (c) - Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
5 | * | |
6 | * LTTng sched probes. | |
7 | * | |
8 | * Dual LGPL v2.1/GPL v2 license. | |
9 | */ | |
10 | ||
11 | #include <linux/module.h> | |
12 | #include <linux/slab.h> | |
13 | #include <asm/ptrace.h> | |
14 | #include <asm/syscall.h> | |
15 | ||
16 | #include "ltt-events.h" | |
17 | ||
18 | static void syscall_entry_probe(void *__data, struct pt_regs *regs, long id); | |
19 | ||
f7bdf4db MD |
20 | /* |
21 | * Take care of NOARGS not supported by mainline. | |
22 | */ | |
23 | #define DECLARE_EVENT_CLASS_NOARGS(name, tstruct, assign, print) | |
24 | #define DEFINE_EVENT_NOARGS(template, name) | |
25 | #define TRACE_EVENT_NOARGS(name, struct, assign, print) | |
26 | ||
259b6cb3 MD |
27 | /* |
28 | * Create LTTng tracepoint probes. | |
29 | */ | |
30 | #define LTTNG_PACKAGE_BUILD | |
31 | #define CREATE_TRACE_POINTS | |
32 | ||
33 | /* Hijack probe callback for system calls */ | |
34 | #define TP_PROBE_CB(_template) &syscall_entry_probe | |
35 | #define TP_MODULE_OVERRIDE | |
36 | ||
37 | #define TRACE_INCLUDE_PATH ../instrumentation/syscalls/headers | |
177b3692 MD |
38 | #include "instrumentation/syscalls/headers/syscalls_integers.h" |
39 | #include "instrumentation/syscalls/headers/syscalls_pointers.h" | |
63728b02 | 40 | #include "instrumentation/syscalls/headers/syscalls_unknown.h" |
259b6cb3 MD |
41 | |
42 | #undef TP_MODULE_OVERRIDE | |
43 | #undef TP_PROBE_CB | |
44 | #undef LTTNG_PACKAGE_BUILD | |
45 | #undef CREATE_TRACE_POINTS | |
46 | ||
47 | struct trace_syscall_entry { | |
48 | void *func; | |
f7bdf4db | 49 | const struct lttng_event_desc *desc; |
259b6cb3 MD |
50 | const struct lttng_event_field *fields; |
51 | unsigned int nrargs; | |
52 | }; | |
53 | ||
259b6cb3 MD |
54 | #define CREATE_SYSCALL_TABLE |
55 | ||
56 | #undef TRACE_SYSCALL_TABLE | |
f7bdf4db | 57 | #define TRACE_SYSCALL_TABLE(_template, _name, _nr, _nrargs) \ |
259b6cb3 | 58 | [ _nr ] = { \ |
f7bdf4db | 59 | .func = __event_probe__##_template, \ |
259b6cb3 | 60 | .nrargs = (_nrargs), \ |
f7bdf4db MD |
61 | .fields = __event_fields___##_template, \ |
62 | .desc = &__event_desc___##_name, \ | |
259b6cb3 MD |
63 | }, |
64 | ||
65 | static struct trace_syscall_entry sc_table[] = { | |
177b3692 MD |
66 | #include "instrumentation/syscalls/headers/syscalls_integers.h" |
67 | #include "instrumentation/syscalls/headers/syscalls_pointers.h" | |
259b6cb3 MD |
68 | }; |
69 | ||
63728b02 MD |
70 | static int sc_table_filled; |
71 | ||
259b6cb3 MD |
72 | #undef CREATE_SYSCALL_TABLE |
73 | ||
f405cfce MD |
74 | static void syscall_entry_unknown(struct ltt_channel *chan, |
75 | struct pt_regs *regs, unsigned int id) | |
76 | { | |
77 | unsigned long args[UNKNOWN_SYSCALL_NRARGS]; | |
78 | struct ltt_event *event; | |
79 | ||
80 | event = chan->sc_unknown; | |
81 | syscall_get_arguments(current, regs, 0, UNKNOWN_SYSCALL_NRARGS, args); | |
82 | __event_probe__sys_unknown(event, id, args); | |
83 | } | |
84 | ||
259b6cb3 MD |
85 | static void syscall_entry_probe(void *__data, struct pt_regs *regs, long id) |
86 | { | |
87 | struct trace_syscall_entry *entry; | |
88 | struct ltt_channel *chan = __data; | |
89 | struct ltt_event *event; | |
90 | ||
f405cfce MD |
91 | if (unlikely(id >= ARRAY_SIZE(sc_table))) { |
92 | syscall_entry_unknown(chan, regs, id); | |
259b6cb3 | 93 | return; |
f405cfce | 94 | } |
259b6cb3 | 95 | event = chan->sc_table[id]; |
f405cfce MD |
96 | if (unlikely(!event)) { |
97 | syscall_entry_unknown(chan, regs, id); | |
98 | return; | |
99 | } | |
100 | entry = &sc_table[id]; | |
101 | WARN_ON_ONCE(!entry); | |
259b6cb3 MD |
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 | ||
259b6cb3 MD |
191 | int lttng_syscalls_register(struct ltt_channel *chan, void *filter) |
192 | { | |
193 | unsigned int i; | |
194 | int ret; | |
195 | ||
196 | wrapper_vmalloc_sync_all(); | |
259b6cb3 MD |
197 | |
198 | if (!chan->sc_table) { | |
199 | /* create syscall table mapping syscall to events */ | |
200 | chan->sc_table = kzalloc(sizeof(struct ltt_event *) | |
201 | * ARRAY_SIZE(sc_table), GFP_KERNEL); | |
202 | if (!chan->sc_table) | |
203 | return -ENOMEM; | |
204 | } | |
205 | ||
f405cfce MD |
206 | if (!chan->sc_unknown) { |
207 | struct lttng_kernel_event ev; | |
208 | ||
209 | const struct lttng_event_desc *desc = | |
210 | &__event_desc___sys_unknown; | |
211 | memset(&ev, 0, sizeof(ev)); | |
212 | strncpy(ev.name, desc->name, LTTNG_SYM_NAME_LEN); | |
213 | ev.name[LTTNG_SYM_NAME_LEN - 1] = '\0'; | |
214 | ev.instrumentation = LTTNG_KERNEL_NOOP; | |
215 | chan->sc_unknown = ltt_event_create(chan, &ev, filter, | |
216 | desc); | |
217 | if (!chan->sc_unknown) { | |
218 | return -EINVAL; | |
219 | } | |
220 | } | |
221 | ||
259b6cb3 MD |
222 | /* Allocate events for each syscall, insert into table */ |
223 | for (i = 0; i < ARRAY_SIZE(sc_table); i++) { | |
224 | struct lttng_kernel_event ev; | |
225 | const struct lttng_event_desc *desc = sc_table[i].desc; | |
226 | ||
f405cfce MD |
227 | if (!desc) { |
228 | /* Unknown syscall */ | |
229 | continue; | |
230 | } | |
259b6cb3 MD |
231 | /* |
232 | * Skip those already populated by previous failed | |
233 | * register for this channel. | |
234 | */ | |
235 | if (chan->sc_table[i]) | |
236 | continue; | |
237 | memset(&ev, 0, sizeof(ev)); | |
238 | strncpy(ev.name, desc->name, LTTNG_SYM_NAME_LEN); | |
239 | ev.name[LTTNG_SYM_NAME_LEN - 1] = '\0'; | |
240 | ev.instrumentation = LTTNG_KERNEL_NOOP; | |
241 | chan->sc_table[i] = ltt_event_create(chan, &ev, filter, | |
242 | desc); | |
243 | if (!chan->sc_table[i]) { | |
244 | /* | |
245 | * If something goes wrong in event registration | |
246 | * after the first one, we have no choice but to | |
247 | * leave the previous events in there, until | |
248 | * deleted by session teardown. | |
249 | */ | |
250 | return -EINVAL; | |
251 | } | |
252 | } | |
253 | ret = tracepoint_probe_register("sys_enter", | |
254 | (void *) syscall_entry_probe, chan); | |
63728b02 MD |
255 | if (ret) |
256 | return ret; | |
257 | /* | |
258 | * We change the name of sys_exit tracepoint due to namespace | |
259 | * conflict with sys_exit syscall entry. | |
260 | */ | |
261 | ret = tracepoint_probe_register("sys_exit", | |
262 | (void *) __event_probe__exit_syscall, chan); | |
263 | if (ret) { | |
264 | WARN_ON_ONCE(tracepoint_probe_unregister("sys_enter", | |
265 | (void *) syscall_entry_probe, chan)); | |
266 | } | |
259b6cb3 MD |
267 | return ret; |
268 | } | |
269 | ||
270 | /* | |
271 | * Only called at session destruction. | |
272 | */ | |
273 | int lttng_syscalls_unregister(struct ltt_channel *chan) | |
274 | { | |
275 | int ret; | |
276 | ||
277 | if (!chan->sc_table) | |
278 | return 0; | |
63728b02 MD |
279 | ret = tracepoint_probe_unregister("sys_exit", |
280 | (void *) __event_probe__exit_syscall, chan); | |
281 | if (ret) | |
282 | return ret; | |
259b6cb3 MD |
283 | ret = tracepoint_probe_unregister("sys_enter", |
284 | (void *) syscall_entry_probe, chan); | |
285 | if (ret) | |
286 | return ret; | |
287 | /* ltt_event destroy will be performed by ltt_session_destroy() */ | |
288 | kfree(chan->sc_table); | |
289 | return 0; | |
290 | } |