Commit | Line | Data |
---|---|---|
834978fd | 1 | /* |
ab5be9fa | 2 | * Copyright (C) 2014 David Goulet <dgoulet@efficios.com> |
834978fd | 3 | * |
ab5be9fa | 4 | * SPDX-License-Identifier: GPL-2.0-only |
834978fd | 5 | * |
834978fd DG |
6 | */ |
7 | ||
6c1c0768 | 8 | #define _LGPL_SOURCE |
98123e1c JR |
9 | #include <stdbool.h> |
10 | ||
834978fd DG |
11 | #include <common/common.h> |
12 | #include <common/kernel-ctl/kernel-ctl.h> | |
13 | ||
14 | #include "lttng-sessiond.h" | |
15 | #include "kernel.h" | |
0dbc2034 | 16 | #include "lttng-syscall.h" |
834978fd DG |
17 | #include "utils.h" |
18 | ||
19 | /* Global syscall table. */ | |
20 | struct syscall *syscall_table; | |
21 | ||
22 | /* Number of entry in the syscall table. */ | |
23 | static size_t syscall_table_nb_entry; | |
24 | ||
25 | /* | |
26 | * Populate the system call table using the kernel tracer. | |
27 | * | |
28 | * Return 0 on success and the syscall table is allocated. On error, a negative | |
1f47715a | 29 | * value is returned. |
834978fd | 30 | */ |
7d268848 | 31 | int syscall_init_table(int tracer_fd) |
834978fd DG |
32 | { |
33 | int ret, fd, err; | |
34 | size_t nbmem; | |
35 | FILE *fp; | |
36 | /* Syscall data from the kernel. */ | |
98123e1c JR |
37 | size_t index = 0; |
38 | bool at_least_one_syscall = false; | |
834978fd DG |
39 | uint32_t bitness; |
40 | char name[SYSCALL_NAME_LEN]; | |
41 | ||
42 | DBG3("Syscall init system call table"); | |
43 | ||
7d268848 | 44 | fd = kernctl_syscall_list(tracer_fd); |
834978fd | 45 | if (fd < 0) { |
32af2c95 | 46 | ret = fd; |
834978fd DG |
47 | PERROR("kernelctl syscall list"); |
48 | goto error_ioctl; | |
49 | } | |
50 | ||
51 | fp = fdopen(fd, "r"); | |
52 | if (!fp) { | |
53 | ret = -errno; | |
54 | PERROR("syscall list fdopen"); | |
55 | goto error_fp; | |
56 | } | |
57 | ||
58 | nbmem = SYSCALL_TABLE_INIT_SIZE; | |
59 | syscall_table = zmalloc(sizeof(struct syscall) * nbmem); | |
60 | if (!syscall_table) { | |
61 | ret = -errno; | |
62 | PERROR("syscall list zmalloc"); | |
63 | goto error; | |
64 | } | |
65 | ||
66 | while (fscanf(fp, | |
97282ce2 | 67 | "syscall { index = %zu; \ |
834978fd DG |
68 | name = %" XSTR(SYSCALL_NAME_LEN) "[^;]; \ |
69 | bitness = %u; };\n", | |
70 | &index, name, &bitness) == 3) { | |
98123e1c JR |
71 | at_least_one_syscall = true; |
72 | if (index >= nbmem) { | |
834978fd DG |
73 | struct syscall *new_list; |
74 | size_t new_nbmem; | |
75 | ||
76 | /* Double memory size. */ | |
98123e1c | 77 | new_nbmem = max(index + 1, nbmem << 1); |
ec93758c | 78 | if (new_nbmem > (SIZE_MAX / sizeof(*new_list))) { |
1f47715a DG |
79 | /* Overflow, stop everything, something went really wrong. */ |
80 | ERR("Syscall listing memory size overflow. Stopping"); | |
81 | free(syscall_table); | |
82 | syscall_table = NULL; | |
83 | ret = -EINVAL; | |
84 | goto error; | |
85 | } | |
834978fd DG |
86 | |
87 | DBG("Reallocating syscall table from %zu to %zu entries", nbmem, | |
88 | new_nbmem); | |
89 | new_list = realloc(syscall_table, new_nbmem * sizeof(*new_list)); | |
90 | if (!new_list) { | |
91 | ret = -errno; | |
92 | PERROR("syscall list realloc"); | |
93 | goto error; | |
94 | } | |
95 | ||
96 | /* Zero out the new memory. */ | |
97 | memset(new_list + nbmem, 0, | |
98 | (new_nbmem - nbmem) * sizeof(*new_list)); | |
99 | nbmem = new_nbmem; | |
100 | syscall_table = new_list; | |
101 | } | |
102 | syscall_table[index].index = index; | |
103 | syscall_table[index].bitness = bitness; | |
39e3c47a MD |
104 | if (lttng_strncpy(syscall_table[index].name, name, |
105 | sizeof(syscall_table[index].name))) { | |
106 | ret = -EINVAL; | |
107 | free(syscall_table); | |
108 | syscall_table = NULL; | |
109 | goto error; | |
110 | } | |
834978fd DG |
111 | /* |
112 | DBG("Syscall name '%s' at index %" PRIu32 " of bitness %u", | |
113 | syscall_table[index].name, | |
114 | syscall_table[index].index, | |
115 | syscall_table[index].bitness); | |
116 | */ | |
117 | } | |
118 | ||
98123e1c JR |
119 | /* Index starts at 0. */ |
120 | if (at_least_one_syscall) { | |
121 | syscall_table_nb_entry = index + 1; | |
122 | } | |
834978fd DG |
123 | |
124 | ret = 0; | |
125 | ||
126 | error: | |
127 | err = fclose(fp); | |
128 | if (err) { | |
129 | PERROR("syscall list fclose"); | |
130 | } | |
131 | return ret; | |
132 | ||
133 | error_fp: | |
134 | err = close(fd); | |
135 | if (err) { | |
136 | PERROR("syscall list close"); | |
137 | } | |
138 | ||
139 | error_ioctl: | |
140 | return ret; | |
141 | } | |
142 | ||
143 | /* | |
144 | * Helper function for the list syscalls command that empty the temporary | |
145 | * syscall hashtable used to track duplicate between 32 and 64 bit arch. | |
146 | * | |
147 | * This empty the hash table and destroys it after. After this, the pointer is | |
148 | * unsuable. RCU read side lock MUST be acquired before calling this. | |
149 | */ | |
150 | static void destroy_syscall_ht(struct lttng_ht *ht) | |
151 | { | |
152 | struct lttng_ht_iter iter; | |
153 | struct syscall *ksyscall; | |
154 | ||
155 | DBG3("Destroying syscall hash table."); | |
156 | ||
157 | if (!ht) { | |
158 | return; | |
159 | } | |
160 | ||
161 | cds_lfht_for_each_entry(ht->ht, &iter.iter, ksyscall, node.node) { | |
162 | int ret; | |
163 | ||
164 | ret = lttng_ht_del(ht, &iter); | |
a0377dfe | 165 | LTTNG_ASSERT(!ret); |
834978fd DG |
166 | free(ksyscall); |
167 | } | |
168 | ht_cleanup_push(ht); | |
169 | } | |
170 | ||
171 | /* | |
172 | * Allocate the given hashtable pointer. | |
173 | * | |
174 | * Return 0 on success else a negative LTTNG error value. | |
175 | */ | |
176 | static int init_syscall_ht(struct lttng_ht **ht) | |
177 | { | |
178 | int ret; | |
179 | ||
180 | *ht = lttng_ht_new(0, LTTNG_HT_TYPE_STRING); | |
181 | if (!*ht) { | |
182 | ret = -LTTNG_ERR_NOMEM; | |
183 | } else { | |
184 | ret = 0; | |
185 | } | |
186 | ||
187 | return ret; | |
188 | } | |
189 | ||
190 | /* | |
191 | * Lookup a syscall in the given hash table by name. | |
192 | * | |
193 | * Return syscall object if found or else NULL. | |
194 | */ | |
195 | static struct syscall *lookup_syscall(struct lttng_ht *ht, const char *name) | |
196 | { | |
197 | struct lttng_ht_node_str *node; | |
198 | struct lttng_ht_iter iter; | |
199 | struct syscall *ksyscall = NULL; | |
200 | ||
a0377dfe FD |
201 | LTTNG_ASSERT(ht); |
202 | LTTNG_ASSERT(name); | |
834978fd DG |
203 | |
204 | lttng_ht_lookup(ht, (void *) name, &iter); | |
205 | node = lttng_ht_iter_get_node_str(&iter); | |
206 | if (node) { | |
207 | ksyscall = caa_container_of(node, struct syscall, node); | |
208 | } | |
209 | ||
210 | return ksyscall; | |
211 | } | |
212 | ||
213 | /* | |
214 | * Using the given syscall object in the events array with the bitness of the | |
215 | * syscall at index in the syscall table. | |
216 | */ | |
217 | static void update_event_syscall_bitness(struct lttng_event *events, | |
218 | unsigned int index, unsigned int syscall_index) | |
219 | { | |
a0377dfe | 220 | LTTNG_ASSERT(events); |
834978fd DG |
221 | |
222 | if (syscall_table[index].bitness == 32) { | |
223 | events[syscall_index].flags |= LTTNG_EVENT_FLAG_SYSCALL_32; | |
224 | } else { | |
225 | events[syscall_index].flags |= LTTNG_EVENT_FLAG_SYSCALL_64; | |
226 | } | |
227 | } | |
228 | ||
229 | /* | |
230 | * Allocate and initialize syscall object and add it to the given hashtable. | |
231 | * | |
232 | * Return 0 on success else -LTTNG_ERR_NOMEM. | |
233 | */ | |
234 | static int add_syscall_to_ht(struct lttng_ht *ht, unsigned int index, | |
235 | unsigned int syscall_index) | |
236 | { | |
237 | int ret; | |
238 | struct syscall *ksyscall; | |
239 | ||
a0377dfe | 240 | LTTNG_ASSERT(ht); |
834978fd DG |
241 | |
242 | ksyscall = zmalloc(sizeof(*ksyscall)); | |
243 | if (!ksyscall) { | |
244 | ret = -LTTNG_ERR_NOMEM; | |
245 | goto error; | |
246 | } | |
247 | ||
248 | strncpy(ksyscall->name, syscall_table[index].name, | |
249 | sizeof(ksyscall->name)); | |
250 | ksyscall->bitness = syscall_table[index].bitness; | |
251 | ksyscall->index = syscall_index; | |
252 | lttng_ht_node_init_str(&ksyscall->node, ksyscall->name); | |
253 | lttng_ht_add_unique_str(ht, &ksyscall->node); | |
254 | ret = 0; | |
255 | ||
256 | error: | |
257 | return ret; | |
258 | } | |
259 | ||
260 | /* | |
261 | * List syscalls present in the kernel syscall global array, allocate and | |
262 | * populate the events structure with them. Skip the empty syscall name. | |
263 | * | |
264 | * Return the number of entries in the array else a negative value. | |
265 | */ | |
266 | ssize_t syscall_table_list(struct lttng_event **_events) | |
267 | { | |
268 | int i, index = 0; | |
269 | ssize_t ret; | |
270 | struct lttng_event *events; | |
271 | /* Hash table used to filter duplicate out. */ | |
272 | struct lttng_ht *syscalls_ht = NULL; | |
273 | ||
a0377dfe | 274 | LTTNG_ASSERT(_events); |
834978fd DG |
275 | |
276 | DBG("Syscall table listing."); | |
277 | ||
278 | rcu_read_lock(); | |
279 | ||
280 | /* | |
281 | * Allocate at least the number of total syscall we have even if some of | |
282 | * them might not be valid. The count below will make sure to return the | |
283 | * right size of the events array. | |
284 | */ | |
285 | events = zmalloc(syscall_table_nb_entry * sizeof(*events)); | |
286 | if (!events) { | |
287 | PERROR("syscall table list zmalloc"); | |
288 | ret = -LTTNG_ERR_NOMEM; | |
289 | goto error; | |
290 | } | |
291 | ||
292 | ret = init_syscall_ht(&syscalls_ht); | |
293 | if (ret < 0) { | |
294 | goto error; | |
295 | } | |
296 | ||
297 | for (i = 0; i < syscall_table_nb_entry; i++) { | |
298 | struct syscall *ksyscall; | |
299 | ||
300 | /* Skip empty syscalls. */ | |
301 | if (*syscall_table[i].name == '\0') { | |
302 | continue; | |
303 | } | |
304 | ||
305 | ksyscall = lookup_syscall(syscalls_ht, syscall_table[i].name); | |
306 | if (ksyscall) { | |
307 | update_event_syscall_bitness(events, i, ksyscall->index); | |
308 | continue; | |
309 | } | |
310 | ||
311 | ret = add_syscall_to_ht(syscalls_ht, i, index); | |
312 | if (ret < 0) { | |
313 | goto error; | |
314 | } | |
315 | ||
316 | /* Copy the event information in the event's array. */ | |
317 | strncpy(events[index].name, syscall_table[i].name, | |
318 | sizeof(events[index].name)); | |
319 | update_event_syscall_bitness(events, i, index); | |
320 | events[index].type = LTTNG_EVENT_SYSCALL; | |
321 | /* This makes the command line not print the enabled/disabled field. */ | |
322 | events[index].enabled = -1; | |
323 | index++; | |
324 | } | |
325 | ||
326 | destroy_syscall_ht(syscalls_ht); | |
327 | *_events = events; | |
328 | rcu_read_unlock(); | |
329 | return index; | |
330 | ||
331 | error: | |
332 | destroy_syscall_ht(syscalls_ht); | |
333 | free(events); | |
334 | rcu_read_unlock(); | |
335 | return ret; | |
336 | } |