| User: | Jiri Slaby |
| Error type: | Leaving function in locked state |
| Error type description: | Some lock is not unlocked on all paths of a function, so it is leaked |
| File location: | net/irda/discovery.c |
| Line in file: | 339 |
| Project: | Linux Kernel |
| Project version: | 2.6.28 |
| Tools: |
Stanse
(1.2)
|
| Entered: | 2012-05-21 20:30:05 UTC |
1/********************************************************************* 2 * 3 * Filename: discovery.c 4 * Version: 0.1 5 * Description: Routines for handling discoveries at the IrLMP layer 6 * Status: Experimental. 7 * Author: Dag Brattli <dagb@cs.uit.no> 8 * Created at: Tue Apr 6 15:33:50 1999 9 * Modified at: Sat Oct 9 17:11:31 1999 10 * Modified by: Dag Brattli <dagb@cs.uit.no> 11 * Modified at: Fri May 28 3:11 CST 1999 12 * Modified by: Horst von Brand <vonbrand@sleipnir.valparaiso.cl> 13 * 14 * Copyright (c) 1999 Dag Brattli, All Rights Reserved. 15 * 16 * This program is free software; you can redistribute it and/or 17 * modify it under the terms of the GNU General Public License as 18 * published by the Free Software Foundation; either version 2 of 19 * the License, or (at your option) any later version. 20 * 21 * This program is distributed in the hope that it will be useful, 22 * but WITHOUT ANY WARRANTY; without even the implied warranty of 23 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 24 * GNU General Public License for more details. 25 * 26 * You should have received a copy of the GNU General Public License 27 * along with this program; if not, write to the Free Software 28 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, 29 * MA 02111-1307 USA 30 * 31 ********************************************************************/ 32 33#include <linux/string.h> 34#include <linux/socket.h> 35#include <linux/fs.h> 36#include <linux/seq_file.h> 37 38#include <net/irda/irda.h> 39#include <net/irda/irlmp.h> 40 41#include <net/irda/discovery.h> 42 43#include <asm/unaligned.h> 44 45/* 46 * Function irlmp_add_discovery (cachelog, discovery) 47 * 48 * Add a new discovery to the cachelog, and remove any old discoveries 49 * from the same device 50 * 51 * Note : we try to preserve the time this device was *first* discovered 52 * (as opposed to the time of last discovery used for cleanup). This is 53 * used by clients waiting for discovery events to tell if the device 54 * discovered is "new" or just the same old one. They can't rely there 55 * on a binary flag (new/old), because not all discovery events are 56 * propagated to them, and they might not always listen, so they would 57 * miss some new devices popping up... 58 * Jean II 59 */ 60void irlmp_add_discovery(hashbin_t *cachelog, discovery_t *new) 61{ 62 discovery_t *discovery, *node; 63 unsigned long flags; 64 65 /* Set time of first discovery if node is new (see below) */ 66 new->firststamp = new->timestamp; 67 68 spin_lock_irqsave(&cachelog->hb_spinlock, flags); 69 70 /* 71 * Remove all discoveries of devices that has previously been 72 * discovered on the same link with the same name (info), or the 73 * same daddr. We do this since some devices (mostly PDAs) change 74 * their device address between every discovery. 75 */ 76 discovery = (discovery_t *) hashbin_get_first(cachelog); 77 while (discovery != NULL ) { 78 node = discovery; 79 80 /* Be sure to stay one item ahead */ 81 discovery = (discovery_t *) hashbin_get_next(cachelog); 82 83 if ((node->data.saddr == new->data.saddr) && 84 ((node->data.daddr == new->data.daddr) || 85 (strcmp(node->data.info, new->data.info) == 0))) 86 { 87 /* This discovery is a previous discovery 88 * from the same device, so just remove it 89 */ 90 hashbin_remove_this(cachelog, (irda_queue_t *) node); 91 /* Check if hints bits are unchanged */ 92 if (get_unaligned((__u16 *)node->data.hints) == get_unaligned((__u16 *)new->data.hints)) 93 /* Set time of first discovery for this node */ 94 new->firststamp = node->firststamp; 95 kfree(node); 96 } 97 } 98 99 /* Insert the new and updated version */ 100 hashbin_insert(cachelog, (irda_queue_t *) new, new->data.daddr, NULL); 101 102 spin_unlock_irqrestore(&cachelog->hb_spinlock, flags); 103} 104 105/* 106 * Function irlmp_add_discovery_log (cachelog, log) 107 * 108 * Merge a disovery log into the cachelog. 109 * 110 */ 111void irlmp_add_discovery_log(hashbin_t *cachelog, hashbin_t *log) 112{ 113 discovery_t *discovery; 114 115 IRDA_DEBUG(4, "%s()\n", __func__); 116 117 /* 118 * If log is missing this means that IrLAP was unable to perform the 119 * discovery, so restart discovery again with just the half timeout 120 * of the normal one. 121 */ 122 /* Well... It means that there was nobody out there - Jean II */ 123 if (log == NULL) { 124 /* irlmp_start_discovery_timer(irlmp, 150); */ 125 return; 126 } 127 128 /* 129 * Locking : we are the only owner of this discovery log, so 130 * no need to lock it. 131 * We just need to lock the global log in irlmp_add_discovery(). 132 */ 133 discovery = (discovery_t *) hashbin_remove_first(log); 134 while (discovery != NULL) { 135 irlmp_add_discovery(cachelog, discovery); 136 137 discovery = (discovery_t *) hashbin_remove_first(log); 138 } 139 140 /* Delete the now empty log */ 141 hashbin_delete(log, (FREE_FUNC) kfree); 142} 143 144/* 145 * Function irlmp_expire_discoveries (log, saddr, force) 146 * 147 * Go through all discoveries and expire all that has stayed too long 148 * 149 * Note : this assume that IrLAP won't change its saddr, which 150 * currently is a valid assumption... 151 */ 152void irlmp_expire_discoveries(hashbin_t *log, __u32 saddr, int force) 153{ 154 discovery_t * discovery; 155 discovery_t * curr; 156 unsigned long flags; 157 discinfo_t * buffer = NULL; 158 int n; /* Size of the full log */ 159 int i = 0; /* How many we expired */ 160 161 IRDA_ASSERT(log != NULL, return;); 162 IRDA_DEBUG(4, "%s()\n", __func__); 163 164 spin_lock_irqsave(&log->hb_spinlock, flags); 165 166 discovery = (discovery_t *) hashbin_get_first(log); 167 while (discovery != NULL) { 168 /* Be sure to be one item ahead */ 169 curr = discovery; 170 discovery = (discovery_t *) hashbin_get_next(log); 171 172 /* Test if it's time to expire this discovery */ 173 if ((curr->data.saddr == saddr) && 174 (force || 175 ((jiffies - curr->timestamp) > DISCOVERY_EXPIRE_TIMEOUT))) 176 { 177 /* Create buffer as needed. 178 * As this function get called a lot and most time 179 * we don't have anything to put in the log (we are 180 * quite picky), we can save a lot of overhead 181 * by not calling kmalloc. Jean II */ 182 if(buffer == NULL) { 183 /* Create the client specific buffer */ 184 n = HASHBIN_GET_SIZE(log); 185 buffer = kmalloc(n * sizeof(struct irda_device_info), GFP_ATOMIC); 186 if (buffer == NULL) { 187 spin_unlock_irqrestore(&log->hb_spinlock, flags); 188 return; 189 } 190 191 } 192 193 /* Copy discovery information */ 194 memcpy(&(buffer[i]), &(curr->data), 195 sizeof(discinfo_t)); 196 i++; 197 198 /* Remove it from the log */ 199 curr = hashbin_remove_this(log, (irda_queue_t *) curr); 200 kfree(curr); 201 } 202 } 203 204 /* Drop the spinlock before calling the higher layers, as 205 * we can't guarantee they won't call us back and create a 206 * deadlock. We will work on our own private data, so we 207 * don't care to be interrupted. - Jean II */ 208 spin_unlock_irqrestore(&log->hb_spinlock, flags); 209 210 if(buffer == NULL) 211 return; 212 213 /* Tell IrLMP and registered clients about it */ 214 irlmp_discovery_expiry(buffer, i); 215 216 /* Free up our buffer */ 217 kfree(buffer); 218} 219 220#if 0 221/* 222 * Function irlmp_dump_discoveries (log) 223 * 224 * Print out all discoveries in log 225 * 226 */ 227void irlmp_dump_discoveries(hashbin_t *log) 228{ 229 discovery_t *discovery; 230 231 IRDA_ASSERT(log != NULL, return;); 232 233 discovery = (discovery_t *) hashbin_get_first(log); 234 while (discovery != NULL) { 235 IRDA_DEBUG(0, "Discovery:\n"); 236 IRDA_DEBUG(0, " daddr=%08x\n", discovery->data.daddr); 237 IRDA_DEBUG(0, " saddr=%08x\n", discovery->data.saddr); 238 IRDA_DEBUG(0, " nickname=%s\n", discovery->data.info); 239 240 discovery = (discovery_t *) hashbin_get_next(log); 241 } 242} 243#endif 244 245/* 246 * Function irlmp_copy_discoveries (log, pn, mask) 247 * 248 * Copy all discoveries in a buffer 249 * 250 * This function implement a safe way for lmp clients to access the 251 * discovery log. The basic problem is that we don't want the log 252 * to change (add/remove) while the client is reading it. If the 253 * lmp client manipulate directly the hashbin, he is sure to get 254 * into troubles... 255 * The idea is that we copy all the current discovery log in a buffer 256 * which is specific to the client and pass this copy to him. As we 257 * do this operation with the spinlock grabbed, we are safe... 258 * Note : we don't want those clients to grab the spinlock, because 259 * we have no control on how long they will hold it... 260 * Note : we choose to copy the log in "struct irda_device_info" to 261 * save space... 262 * Note : the client must kfree himself() the log... 263 * Jean II 264 */ 265struct irda_device_info *irlmp_copy_discoveries(hashbin_t *log, int *pn, 266 __u16 mask, int old_entries) 267{ 268 discovery_t * discovery; 269 unsigned long flags; 270 discinfo_t * buffer = NULL; 271 int j_timeout = (sysctl_discovery_timeout * HZ); 272 int n; /* Size of the full log */ 273 int i = 0; /* How many we picked */ 274 275 IRDA_ASSERT(pn != NULL, return NULL;); 276 IRDA_ASSERT(log != NULL, return NULL;); 277 278 /* Save spin lock */ 279 spin_lock_irqsave(&log->hb_spinlock, flags); 280 281 discovery = (discovery_t *) hashbin_get_first(log); 282 while (discovery != NULL) { 283 /* Mask out the ones we don't want : 284 * We want to match the discovery mask, and to get only 285 * the most recent one (unless we want old ones) */ 286 if ((get_unaligned((__u16 *)discovery->data.hints) & mask) && 287 ((old_entries) || 288 ((jiffies - discovery->firststamp) < j_timeout))) { 289 /* Create buffer as needed. 290 * As this function get called a lot and most time 291 * we don't have anything to put in the log (we are 292 * quite picky), we can save a lot of overhead 293 * by not calling kmalloc. Jean II */ 294 if(buffer == NULL) { 295 /* Create the client specific buffer */ 296 n = HASHBIN_GET_SIZE(log); 297 buffer = kmalloc(n * sizeof(struct irda_device_info), GFP_ATOMIC); 298 if (buffer == NULL) { 299 spin_unlock_irqrestore(&log->hb_spinlock, flags); 300 return NULL; 301 } 302 303 } 304 305 /* Copy discovery information */ 306 memcpy(&(buffer[i]), &(discovery->data), 307 sizeof(discinfo_t)); 308 i++; 309 } 310 discovery = (discovery_t *) hashbin_get_next(log); 311 } 312 313 spin_unlock_irqrestore(&log->hb_spinlock, flags); 314 315 /* Get the actual number of device in the buffer and return */ 316 *pn = i; 317 return(buffer); 318} 319 320#ifdef CONFIG_PROC_FS 321static inline discovery_t *discovery_seq_idx(loff_t pos) 322 323{ 324 discovery_t *discovery; 325 326 for (discovery = (discovery_t *) hashbin_get_first(irlmp->cachelog); 327 discovery != NULL; 328 discovery = (discovery_t *) hashbin_get_next(irlmp->cachelog)) { 329 if (pos-- == 0) 330 break; 331 } 332 333 return discovery; 334} 335 336static void *discovery_seq_start(struct seq_file *seq, loff_t *pos) 337{ 338 spin_lock_irq(&irlmp->cachelog->hb_spinlock); 339 return *pos ? discovery_seq_idx(*pos - 1) : SEQ_START_TOKEN; 340} 341 342static void *discovery_seq_next(struct seq_file *seq, void *v, loff_t *pos) 343{ 344 ++*pos; 345 return (v == SEQ_START_TOKEN) 346 ? (void *) hashbin_get_first(irlmp->cachelog) 347 : (void *) hashbin_get_next(irlmp->cachelog); 348} 349 350static void discovery_seq_stop(struct seq_file *seq, void *v) 351{ 352 spin_unlock_irq(&irlmp->cachelog->hb_spinlock); 353} 354 355static int discovery_seq_show(struct seq_file *seq, void *v) 356{ 357 if (v == SEQ_START_TOKEN) 358 seq_puts(seq, "IrLMP: Discovery log:\n\n"); 359 else { 360 const discovery_t *discovery = v; 361 362 seq_printf(seq, "nickname: %s, hint: 0x%02x%02x", 363 discovery->data.info, 364 discovery->data.hints[0], 365 discovery->data.hints[1]); 366#if 0 367 if ( discovery->data.hints[0] & HINT_PNP) 368 seq_puts(seq, "PnP Compatible "); 369 if ( discovery->data.hints[0] & HINT_PDA) 370 seq_puts(seq, "PDA/Palmtop "); 371 if ( discovery->data.hints[0] & HINT_COMPUTER) 372 seq_puts(seq, "Computer "); 373 if ( discovery->data.hints[0] & HINT_PRINTER) 374 seq_puts(seq, "Printer "); 375 if ( discovery->data.hints[0] & HINT_MODEM) 376 seq_puts(seq, "Modem "); 377 if ( discovery->data.hints[0] & HINT_FAX) 378 seq_puts(seq, "Fax "); 379 if ( discovery->data.hints[0] & HINT_LAN) 380 seq_puts(seq, "LAN Access "); 381 382 if ( discovery->data.hints[1] & HINT_TELEPHONY) 383 seq_puts(seq, "Telephony "); 384 if ( discovery->data.hints[1] & HINT_FILE_SERVER) 385 seq_puts(seq, "File Server "); 386 if ( discovery->data.hints[1] & HINT_COMM) 387 seq_puts(seq, "IrCOMM "); 388 if ( discovery->data.hints[1] & HINT_OBEX) 389 seq_puts(seq, "IrOBEX "); 390#endif 391 seq_printf(seq,", saddr: 0x%08x, daddr: 0x%08x\n\n", 392 discovery->data.saddr, 393 discovery->data.daddr); 394 395 seq_putc(seq, '\n'); 396 } 397 return 0; 398} 399 400static const struct seq_operations discovery_seq_ops = { 401 .start = discovery_seq_start, 402 .next = discovery_seq_next, 403 .stop = discovery_seq_stop, 404 .show = discovery_seq_show, 405}; 406 407static int discovery_seq_open(struct inode *inode, struct file *file) 408{ 409 IRDA_ASSERT(irlmp != NULL, return -EINVAL;); 410 411 return seq_open(file, &discovery_seq_ops); 412} 413 414const struct file_operations discovery_seq_fops = { 415 .owner = THIS_MODULE, 416 .open = discovery_seq_open, 417 .read = seq_read, 418 .llseek = seq_lseek, 419 .release = seq_release, 420}; 421#endif