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ebabbf58 | 1 | /* |
c0c0989a | 2 | * SPDX-License-Identifier: LGPL-2.1-only |
ebabbf58 MD |
3 | * |
4 | * Copyright (C) 2005-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
ebabbf58 MD |
5 | */ |
6 | ||
7 | #define _LGPL_SOURCE | |
ebabbf58 MD |
8 | #include "shm.h" |
9 | #include <unistd.h> | |
10 | #include <fcntl.h> | |
11 | #include <sys/mman.h> | |
12 | #include <sys/types.h> | |
13 | #include <sys/stat.h> /* For mode constants */ | |
14 | #include <fcntl.h> /* For O_* constants */ | |
15 | #include <assert.h> | |
16 | #include <stdio.h> | |
17 | #include <signal.h> | |
18 | #include <dirent.h> | |
ebabbf58 MD |
19 | #include <limits.h> |
20 | #include <stdbool.h> | |
21 | #include <stdint.h> | |
3d3a2bb8 | 22 | |
ebabbf58 MD |
23 | #ifdef HAVE_LIBNUMA |
24 | #include <numa.h> | |
25 | #include <numaif.h> | |
26 | #endif | |
3d3a2bb8 | 27 | |
eae3c729 | 28 | #include <lttng/ust-utils.h> |
3d3a2bb8 | 29 | |
9d315d6d MJ |
30 | #include "common/macros.h" |
31 | #include "common/ust-fd.h" | |
1be43539 | 32 | #include "common/compat/mmap.h" |
ebabbf58 MD |
33 | |
34 | /* | |
35 | * Ensure we have the required amount of space available by writing 0 | |
36 | * into the entire buffer. Not doing so can trigger SIGBUS when going | |
37 | * beyond the available shm space. | |
38 | */ | |
39 | static | |
40 | int zero_file(int fd, size_t len) | |
41 | { | |
42 | ssize_t retlen; | |
43 | size_t written = 0; | |
44 | char *zeropage; | |
45 | long pagelen; | |
46 | int ret; | |
47 | ||
48 | pagelen = sysconf(_SC_PAGESIZE); | |
49 | if (pagelen < 0) | |
50 | return (int) pagelen; | |
51 | zeropage = calloc(pagelen, 1); | |
52 | if (!zeropage) | |
53 | return -ENOMEM; | |
54 | ||
55 | while (len > written) { | |
56 | do { | |
57 | retlen = write(fd, zeropage, | |
58 | min_t(size_t, pagelen, len - written)); | |
59 | } while (retlen == -1UL && errno == EINTR); | |
60 | if (retlen < 0) { | |
61 | ret = (int) retlen; | |
62 | goto error; | |
63 | } | |
64 | written += retlen; | |
65 | } | |
66 | ret = 0; | |
67 | error: | |
68 | free(zeropage); | |
69 | return ret; | |
70 | } | |
71 | ||
97572c04 | 72 | struct lttng_counter_shm_object_table *lttng_counter_shm_object_table_create(size_t max_nb_obj, bool populate) |
ebabbf58 MD |
73 | { |
74 | struct lttng_counter_shm_object_table *table; | |
75 | ||
97572c04 MD |
76 | table = zmalloc_populate(sizeof(struct lttng_counter_shm_object_table) + |
77 | max_nb_obj * sizeof(table->objects[0]), populate); | |
ebabbf58 MD |
78 | if (!table) |
79 | return NULL; | |
80 | table->size = max_nb_obj; | |
81 | return table; | |
82 | } | |
83 | ||
84 | static | |
85 | struct lttng_counter_shm_object *_lttng_counter_shm_object_table_alloc_shm(struct lttng_counter_shm_object_table *table, | |
86 | size_t memory_map_size, | |
97572c04 | 87 | int cpu_fd, bool populate) |
ebabbf58 | 88 | { |
ebabbf58 | 89 | struct lttng_counter_shm_object *obj; |
97572c04 MD |
90 | int flags = MAP_SHARED; |
91 | int shmfd, ret; | |
ebabbf58 MD |
92 | char *memory_map; |
93 | ||
94 | if (cpu_fd < 0) | |
95 | return NULL; | |
96 | if (table->allocated_len >= table->size) | |
97 | return NULL; | |
98 | obj = &table->objects[table->allocated_len]; | |
99 | ||
100 | /* create shm */ | |
101 | ||
102 | shmfd = cpu_fd; | |
103 | ret = zero_file(shmfd, memory_map_size); | |
104 | if (ret) { | |
105 | PERROR("zero_file"); | |
106 | goto error_zero_file; | |
107 | } | |
108 | ret = ftruncate(shmfd, memory_map_size); | |
109 | if (ret) { | |
110 | PERROR("ftruncate"); | |
111 | goto error_ftruncate; | |
112 | } | |
113 | /* | |
114 | * Also ensure the file metadata is synced with the storage by using | |
115 | * fsync(2). | |
116 | */ | |
117 | ret = fsync(shmfd); | |
118 | if (ret) { | |
119 | PERROR("fsync"); | |
120 | goto error_fsync; | |
121 | } | |
122 | obj->shm_fd_ownership = 0; | |
123 | obj->shm_fd = shmfd; | |
124 | ||
97572c04 MD |
125 | if (populate) |
126 | flags |= LTTNG_MAP_POPULATE; | |
ebabbf58 MD |
127 | /* memory_map: mmap */ |
128 | memory_map = mmap(NULL, memory_map_size, PROT_READ | PROT_WRITE, | |
97572c04 | 129 | flags, shmfd, 0); |
ebabbf58 MD |
130 | if (memory_map == MAP_FAILED) { |
131 | PERROR("mmap"); | |
132 | goto error_mmap; | |
133 | } | |
134 | obj->type = LTTNG_COUNTER_SHM_OBJECT_SHM; | |
135 | obj->memory_map = memory_map; | |
136 | obj->memory_map_size = memory_map_size; | |
137 | obj->allocated_len = 0; | |
138 | obj->index = table->allocated_len++; | |
139 | ||
140 | return obj; | |
141 | ||
142 | error_mmap: | |
143 | error_fsync: | |
144 | error_ftruncate: | |
145 | error_zero_file: | |
146 | return NULL; | |
147 | } | |
148 | ||
149 | static | |
150 | struct lttng_counter_shm_object *_lttng_counter_shm_object_table_alloc_mem(struct lttng_counter_shm_object_table *table, | |
97572c04 | 151 | size_t memory_map_size, bool populate) |
ebabbf58 MD |
152 | { |
153 | struct lttng_counter_shm_object *obj; | |
154 | void *memory_map; | |
155 | ||
156 | if (table->allocated_len >= table->size) | |
157 | return NULL; | |
158 | obj = &table->objects[table->allocated_len]; | |
159 | ||
97572c04 | 160 | memory_map = zmalloc_populate(memory_map_size, populate); |
ebabbf58 MD |
161 | if (!memory_map) |
162 | goto alloc_error; | |
163 | ||
164 | /* no shm_fd */ | |
165 | obj->shm_fd = -1; | |
166 | obj->shm_fd_ownership = 0; | |
167 | ||
168 | obj->type = LTTNG_COUNTER_SHM_OBJECT_MEM; | |
169 | obj->memory_map = memory_map; | |
170 | obj->memory_map_size = memory_map_size; | |
171 | obj->allocated_len = 0; | |
172 | obj->index = table->allocated_len++; | |
173 | ||
174 | return obj; | |
175 | ||
176 | alloc_error: | |
177 | return NULL; | |
178 | } | |
179 | ||
180 | /* | |
181 | * libnuma prints errors on the console even for numa_available(). | |
182 | * Work-around this limitation by using get_mempolicy() directly to | |
183 | * check whether the kernel supports mempolicy. | |
184 | */ | |
185 | #ifdef HAVE_LIBNUMA | |
186 | static bool lttng_is_numa_available(void) | |
187 | { | |
188 | int ret; | |
189 | ||
190 | ret = get_mempolicy(NULL, NULL, 0, NULL, 0); | |
191 | if (ret && errno == ENOSYS) { | |
192 | return false; | |
193 | } | |
194 | return numa_available() > 0; | |
195 | } | |
196 | #endif | |
197 | ||
c494c0f1 | 198 | #ifdef HAVE_LIBNUMA |
ebabbf58 MD |
199 | struct lttng_counter_shm_object *lttng_counter_shm_object_table_alloc(struct lttng_counter_shm_object_table *table, |
200 | size_t memory_map_size, | |
201 | enum lttng_counter_shm_object_type type, | |
202 | int cpu_fd, | |
97572c04 MD |
203 | int cpu, |
204 | bool populate) | |
c494c0f1 MJ |
205 | #else |
206 | struct lttng_counter_shm_object *lttng_counter_shm_object_table_alloc(struct lttng_counter_shm_object_table *table, | |
207 | size_t memory_map_size, | |
208 | enum lttng_counter_shm_object_type type, | |
209 | int cpu_fd, | |
97572c04 MD |
210 | int cpu __attribute__((unused)), |
211 | bool populate) | |
c494c0f1 | 212 | #endif |
ebabbf58 MD |
213 | { |
214 | struct lttng_counter_shm_object *shm_object; | |
215 | #ifdef HAVE_LIBNUMA | |
216 | int oldnode = 0, node; | |
217 | bool numa_avail; | |
218 | ||
219 | numa_avail = lttng_is_numa_available(); | |
220 | if (numa_avail) { | |
221 | oldnode = numa_preferred(); | |
222 | if (cpu >= 0) { | |
223 | node = numa_node_of_cpu(cpu); | |
224 | if (node >= 0) | |
225 | numa_set_preferred(node); | |
226 | } | |
227 | if (cpu < 0 || node < 0) | |
228 | numa_set_localalloc(); | |
229 | } | |
230 | #endif /* HAVE_LIBNUMA */ | |
231 | switch (type) { | |
232 | case LTTNG_COUNTER_SHM_OBJECT_SHM: | |
233 | shm_object = _lttng_counter_shm_object_table_alloc_shm(table, memory_map_size, | |
97572c04 | 234 | cpu_fd, populate); |
ebabbf58 MD |
235 | break; |
236 | case LTTNG_COUNTER_SHM_OBJECT_MEM: | |
97572c04 MD |
237 | shm_object = _lttng_counter_shm_object_table_alloc_mem(table, memory_map_size, |
238 | populate); | |
ebabbf58 MD |
239 | break; |
240 | default: | |
241 | assert(0); | |
242 | } | |
243 | #ifdef HAVE_LIBNUMA | |
244 | if (numa_avail) | |
245 | numa_set_preferred(oldnode); | |
246 | #endif /* HAVE_LIBNUMA */ | |
247 | return shm_object; | |
248 | } | |
249 | ||
250 | struct lttng_counter_shm_object *lttng_counter_shm_object_table_append_shm(struct lttng_counter_shm_object_table *table, | |
97572c04 | 251 | int shm_fd, size_t memory_map_size, bool populate) |
ebabbf58 MD |
252 | { |
253 | struct lttng_counter_shm_object *obj; | |
97572c04 | 254 | int flags = MAP_SHARED; |
ebabbf58 MD |
255 | char *memory_map; |
256 | ||
257 | if (table->allocated_len >= table->size) | |
258 | return NULL; | |
259 | ||
260 | obj = &table->objects[table->allocated_len]; | |
261 | ||
262 | obj->shm_fd = shm_fd; | |
263 | obj->shm_fd_ownership = 1; | |
264 | ||
97572c04 MD |
265 | if (populate) |
266 | flags |= LTTNG_MAP_POPULATE; | |
ebabbf58 MD |
267 | /* memory_map: mmap */ |
268 | memory_map = mmap(NULL, memory_map_size, PROT_READ | PROT_WRITE, | |
97572c04 | 269 | flags, shm_fd, 0); |
ebabbf58 MD |
270 | if (memory_map == MAP_FAILED) { |
271 | PERROR("mmap"); | |
272 | goto error_mmap; | |
273 | } | |
274 | obj->type = LTTNG_COUNTER_SHM_OBJECT_SHM; | |
275 | obj->memory_map = memory_map; | |
276 | obj->memory_map_size = memory_map_size; | |
277 | obj->allocated_len = memory_map_size; | |
278 | obj->index = table->allocated_len++; | |
279 | ||
280 | return obj; | |
281 | ||
282 | error_mmap: | |
283 | return NULL; | |
284 | } | |
285 | ||
286 | /* | |
287 | * Passing ownership of mem to object. | |
288 | */ | |
289 | struct lttng_counter_shm_object *lttng_counter_shm_object_table_append_mem(struct lttng_counter_shm_object_table *table, | |
290 | void *mem, size_t memory_map_size) | |
291 | { | |
292 | struct lttng_counter_shm_object *obj; | |
293 | ||
294 | if (table->allocated_len >= table->size) | |
295 | return NULL; | |
296 | obj = &table->objects[table->allocated_len]; | |
297 | ||
298 | obj->shm_fd = -1; | |
299 | obj->shm_fd_ownership = 0; | |
300 | ||
301 | obj->type = LTTNG_COUNTER_SHM_OBJECT_MEM; | |
302 | obj->memory_map = mem; | |
303 | obj->memory_map_size = memory_map_size; | |
304 | obj->allocated_len = memory_map_size; | |
305 | obj->index = table->allocated_len++; | |
306 | ||
307 | return obj; | |
308 | ||
309 | return NULL; | |
310 | } | |
311 | ||
312 | static | |
313 | void lttng_counter_shmp_object_destroy(struct lttng_counter_shm_object *obj, int consumer) | |
314 | { | |
315 | switch (obj->type) { | |
316 | case LTTNG_COUNTER_SHM_OBJECT_SHM: | |
317 | { | |
318 | int ret; | |
319 | ||
320 | ret = munmap(obj->memory_map, obj->memory_map_size); | |
321 | if (ret) { | |
322 | PERROR("umnmap"); | |
323 | assert(0); | |
324 | } | |
325 | ||
326 | if (obj->shm_fd_ownership) { | |
327 | /* Delete FDs only if called from app (not consumer). */ | |
328 | if (!consumer) { | |
329 | lttng_ust_lock_fd_tracker(); | |
330 | ret = close(obj->shm_fd); | |
331 | if (!ret) { | |
332 | lttng_ust_delete_fd_from_tracker(obj->shm_fd); | |
333 | } else { | |
334 | PERROR("close"); | |
335 | assert(0); | |
336 | } | |
337 | lttng_ust_unlock_fd_tracker(); | |
338 | } else { | |
339 | ret = close(obj->shm_fd); | |
340 | if (ret) { | |
341 | PERROR("close"); | |
342 | assert(0); | |
343 | } | |
344 | } | |
345 | } | |
346 | break; | |
347 | } | |
348 | case LTTNG_COUNTER_SHM_OBJECT_MEM: | |
349 | { | |
350 | free(obj->memory_map); | |
351 | break; | |
352 | } | |
353 | default: | |
354 | assert(0); | |
355 | } | |
356 | } | |
357 | ||
358 | void lttng_counter_shm_object_table_destroy(struct lttng_counter_shm_object_table *table, int consumer) | |
359 | { | |
360 | int i; | |
361 | ||
362 | for (i = 0; i < table->allocated_len; i++) | |
363 | lttng_counter_shmp_object_destroy(&table->objects[i], consumer); | |
364 | free(table); | |
365 | } | |
366 | ||
367 | /* | |
368 | * lttng_counter_zalloc_shm - allocate memory within a shm object. | |
369 | * | |
370 | * Shared memory is already zeroed by shmget. | |
371 | * *NOT* multithread-safe (should be protected by mutex). | |
372 | * Returns a -1, -1 tuple on error. | |
373 | */ | |
374 | struct lttng_counter_shm_ref lttng_counter_zalloc_shm(struct lttng_counter_shm_object *obj, size_t len) | |
375 | { | |
376 | struct lttng_counter_shm_ref ref; | |
377 | struct lttng_counter_shm_ref shm_ref_error = { -1, -1 }; | |
378 | ||
379 | if (obj->memory_map_size - obj->allocated_len < len) | |
380 | return shm_ref_error; | |
381 | ref.index = obj->index; | |
382 | ref.offset = obj->allocated_len; | |
383 | obj->allocated_len += len; | |
384 | return ref; | |
385 | } | |
386 | ||
387 | void lttng_counter_align_shm(struct lttng_counter_shm_object *obj, size_t align) | |
388 | { | |
cd61d9bf | 389 | size_t offset_len = lttng_ust_offset_align(obj->allocated_len, align); |
ebabbf58 MD |
390 | obj->allocated_len += offset_len; |
391 | } |