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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 | |
38 | ||
39 | #include "instrumentation/syscalls/headers/syscalls.h" | |
40 | ||
41 | #undef TP_MODULE_OVERRIDE | |
42 | #undef TP_PROBE_CB | |
43 | #undef LTTNG_PACKAGE_BUILD | |
44 | #undef CREATE_TRACE_POINTS | |
45 | ||
46 | struct trace_syscall_entry { | |
47 | void *func; | |
f7bdf4db | 48 | const struct lttng_event_desc *desc; |
259b6cb3 MD |
49 | const struct lttng_event_field *fields; |
50 | unsigned int nrargs; | |
51 | }; | |
52 | ||
53 | static int sc_table_desc_filled; | |
54 | ||
55 | #define CREATE_SYSCALL_TABLE | |
56 | ||
57 | #undef TRACE_SYSCALL_TABLE | |
f7bdf4db | 58 | #define TRACE_SYSCALL_TABLE(_template, _name, _nr, _nrargs) \ |
259b6cb3 | 59 | [ _nr ] = { \ |
f7bdf4db | 60 | .func = __event_probe__##_template, \ |
259b6cb3 | 61 | .nrargs = (_nrargs), \ |
f7bdf4db MD |
62 | .fields = __event_fields___##_template, \ |
63 | .desc = &__event_desc___##_name, \ | |
259b6cb3 MD |
64 | }, |
65 | ||
66 | static struct trace_syscall_entry sc_table[] = { | |
67 | #include "instrumentation/syscalls/headers/syscalls.h" | |
68 | }; | |
69 | ||
70 | #undef CREATE_SYSCALL_TABLE | |
71 | ||
72 | static void syscall_entry_probe(void *__data, struct pt_regs *regs, long id) | |
73 | { | |
74 | struct trace_syscall_entry *entry; | |
75 | struct ltt_channel *chan = __data; | |
76 | struct ltt_event *event; | |
77 | ||
78 | if (unlikely(id >= ARRAY_SIZE(sc_table))) | |
79 | return; | |
80 | entry = &sc_table[id]; | |
81 | if (unlikely(!entry->func)) | |
82 | return; | |
83 | event = chan->sc_table[id]; | |
84 | WARN_ON_ONCE(!event); | |
85 | ||
86 | switch (entry->nrargs) { | |
87 | case 0: | |
88 | { | |
89 | void (*fptr)(void *__data) = entry->func; | |
90 | ||
91 | fptr(event); | |
92 | break; | |
93 | } | |
94 | case 1: | |
95 | { | |
96 | void (*fptr)(void *__data, unsigned long arg0) = entry->func; | |
97 | unsigned long args[1]; | |
98 | ||
99 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); | |
100 | fptr(event, args[0]); | |
101 | break; | |
102 | } | |
103 | case 2: | |
104 | { | |
105 | void (*fptr)(void *__data, | |
106 | unsigned long arg0, | |
107 | unsigned long arg1) = entry->func; | |
108 | unsigned long args[2]; | |
109 | ||
110 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); | |
111 | fptr(event, args[0], args[1]); | |
112 | break; | |
113 | } | |
114 | case 3: | |
115 | { | |
116 | void (*fptr)(void *__data, | |
117 | unsigned long arg0, | |
118 | unsigned long arg1, | |
119 | unsigned long arg2) = entry->func; | |
120 | unsigned long args[3]; | |
121 | ||
122 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); | |
123 | fptr(event, args[0], args[1], args[2]); | |
124 | break; | |
125 | } | |
126 | case 4: | |
127 | { | |
128 | void (*fptr)(void *__data, | |
129 | unsigned long arg0, | |
130 | unsigned long arg1, | |
131 | unsigned long arg2, | |
132 | unsigned long arg3) = entry->func; | |
133 | unsigned long args[4]; | |
134 | ||
135 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); | |
136 | fptr(event, args[0], args[1], args[2], args[3]); | |
137 | break; | |
138 | } | |
139 | case 5: | |
140 | { | |
141 | void (*fptr)(void *__data, | |
142 | unsigned long arg0, | |
143 | unsigned long arg1, | |
144 | unsigned long arg2, | |
145 | unsigned long arg3, | |
146 | unsigned long arg4) = entry->func; | |
147 | unsigned long args[5]; | |
148 | ||
149 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); | |
150 | fptr(event, args[0], args[1], args[2], args[3], args[4]); | |
151 | break; | |
152 | } | |
153 | case 6: | |
154 | { | |
155 | void (*fptr)(void *__data, | |
156 | unsigned long arg0, | |
157 | unsigned long arg1, | |
158 | unsigned long arg2, | |
159 | unsigned long arg3, | |
160 | unsigned long arg4, | |
161 | unsigned long arg5) = entry->func; | |
162 | unsigned long args[6]; | |
163 | ||
164 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); | |
165 | fptr(event, args[0], args[1], args[2], | |
166 | args[3], args[4], args[5]); | |
167 | break; | |
168 | } | |
169 | default: | |
170 | break; | |
171 | } | |
172 | } | |
173 | ||
259b6cb3 MD |
174 | int lttng_syscalls_register(struct ltt_channel *chan, void *filter) |
175 | { | |
176 | unsigned int i; | |
177 | int ret; | |
178 | ||
179 | wrapper_vmalloc_sync_all(); | |
259b6cb3 MD |
180 | |
181 | if (!chan->sc_table) { | |
182 | /* create syscall table mapping syscall to events */ | |
183 | chan->sc_table = kzalloc(sizeof(struct ltt_event *) | |
184 | * ARRAY_SIZE(sc_table), GFP_KERNEL); | |
185 | if (!chan->sc_table) | |
186 | return -ENOMEM; | |
187 | } | |
188 | ||
189 | /* Allocate events for each syscall, insert into table */ | |
190 | for (i = 0; i < ARRAY_SIZE(sc_table); i++) { | |
191 | struct lttng_kernel_event ev; | |
192 | const struct lttng_event_desc *desc = sc_table[i].desc; | |
193 | ||
194 | if (!desc) | |
195 | continue; | |
196 | /* | |
197 | * Skip those already populated by previous failed | |
198 | * register for this channel. | |
199 | */ | |
200 | if (chan->sc_table[i]) | |
201 | continue; | |
202 | memset(&ev, 0, sizeof(ev)); | |
203 | strncpy(ev.name, desc->name, LTTNG_SYM_NAME_LEN); | |
204 | ev.name[LTTNG_SYM_NAME_LEN - 1] = '\0'; | |
205 | ev.instrumentation = LTTNG_KERNEL_NOOP; | |
206 | chan->sc_table[i] = ltt_event_create(chan, &ev, filter, | |
207 | desc); | |
208 | if (!chan->sc_table[i]) { | |
209 | /* | |
210 | * If something goes wrong in event registration | |
211 | * after the first one, we have no choice but to | |
212 | * leave the previous events in there, until | |
213 | * deleted by session teardown. | |
214 | */ | |
215 | return -EINVAL; | |
216 | } | |
217 | } | |
218 | ret = tracepoint_probe_register("sys_enter", | |
219 | (void *) syscall_entry_probe, chan); | |
220 | return ret; | |
221 | } | |
222 | ||
223 | /* | |
224 | * Only called at session destruction. | |
225 | */ | |
226 | int lttng_syscalls_unregister(struct ltt_channel *chan) | |
227 | { | |
228 | int ret; | |
229 | ||
230 | if (!chan->sc_table) | |
231 | return 0; | |
232 | ret = tracepoint_probe_unregister("sys_enter", | |
233 | (void *) syscall_entry_probe, chan); | |
234 | if (ret) | |
235 | return ret; | |
236 | /* ltt_event destroy will be performed by ltt_session_destroy() */ | |
237 | kfree(chan->sc_table); | |
238 | return 0; | |
239 | } |