Yida Wang | 0bf43bd | 2017-03-22 18:16:31 -0400 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright (c) 2014-2015, 2017, The Linux Foundation. All rights reserved. |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify |
| 5 | * it under the terms of the GNU General Public License version 2 and |
| 6 | * only version 2 as published by the Free Software Foundation. |
| 7 | * |
| 8 | * This program is distributed in the hope that it will be useful, |
| 9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 11 | * GNU General Public License for more details. |
| 12 | */ |
| 13 | |
| 14 | #define pr_fmt(fmt) "seemp: %s: " fmt, __func__ |
| 15 | |
| 16 | #include "seemp_logk.h" |
| 17 | #include "seemp_ringbuf.h" |
| 18 | |
| 19 | #ifndef VM_RESERVED |
| 20 | #define VM_RESERVED (VM_DONTEXPAND | VM_DONTDUMP) |
| 21 | #endif |
| 22 | |
| 23 | #define MASK_BUFFER_SIZE 256 |
| 24 | #define FOUR_MB 4 |
| 25 | #define YEAR_BASE 1900 |
| 26 | |
| 27 | static struct seemp_logk_dev *slogk_dev; |
| 28 | |
| 29 | static unsigned int ring_sz = FOUR_MB; |
| 30 | |
| 31 | /* |
| 32 | * default is besteffort, apps do not get blocked |
| 33 | */ |
| 34 | static unsigned int block_apps; |
| 35 | |
| 36 | |
| 37 | /* |
| 38 | * When this flag is turned on, |
| 39 | * kmalloc should be used for ring buf allocation |
| 40 | * otherwise it is vmalloc. |
| 41 | * default is to use vmalloc |
| 42 | * kmalloc has a limit of 4MB |
| 43 | */ |
| 44 | unsigned int kmalloc_flag; |
| 45 | |
| 46 | static struct class *cl; |
| 47 | |
| 48 | static rwlock_t filter_lock; |
| 49 | static struct seemp_source_mask *pmask; |
| 50 | static unsigned int num_sources; |
| 51 | |
| 52 | static long seemp_logk_reserve_rdblks( |
| 53 | struct seemp_logk_dev *sdev, unsigned long arg); |
| 54 | static long seemp_logk_set_mask(unsigned long arg); |
| 55 | static long seemp_logk_set_mapping(unsigned long arg); |
| 56 | static long seemp_logk_check_filter(unsigned long arg); |
| 57 | |
| 58 | void* (*seemp_logk_kernel_begin)(char **buf); |
| 59 | |
| 60 | void (*seemp_logk_kernel_end)(void *blck); |
| 61 | |
| 62 | /* |
| 63 | * the last param is the permission bits * |
| 64 | * kernel logging is done in three steps: |
| 65 | * (1) fetch a block, fill everything except payload. |
| 66 | * (2) return payload pointer to the caller. |
| 67 | * (3) caller fills its data directly into the payload area. |
| 68 | * (4) caller invoked finish_record(), to finish writing. |
| 69 | */ |
| 70 | void *seemp_logk_kernel_start_record(char **buf) |
| 71 | { |
| 72 | struct seemp_logk_blk *blk; |
| 73 | struct timespec now; |
| 74 | struct tm ts; |
| 75 | int idx; |
| 76 | int ret; |
| 77 | |
| 78 | DEFINE_WAIT(write_wait); |
| 79 | |
| 80 | ret = 0; |
| 81 | idx = 0; |
| 82 | now = current_kernel_time(); |
| 83 | blk = ringbuf_fetch_wr_block(slogk_dev); |
| 84 | if (!blk) { |
| 85 | /* |
| 86 | * there is no blk to write |
| 87 | * if block_apps == 0; quietly return |
| 88 | */ |
| 89 | if (!block_apps) { |
| 90 | *buf = NULL; |
| 91 | return NULL; |
| 92 | } |
| 93 | /*else wait for the blks to be available*/ |
| 94 | while (1) { |
| 95 | mutex_lock(&slogk_dev->lock); |
| 96 | prepare_to_wait(&slogk_dev->writers_wq, |
| 97 | &write_wait, TASK_INTERRUPTIBLE); |
| 98 | ret = (slogk_dev->num_write_avail_blks <= 0); |
| 99 | if (!ret) { |
| 100 | /* don't have to wait*/ |
| 101 | break; |
| 102 | } |
| 103 | mutex_unlock(&slogk_dev->lock); |
| 104 | if (signal_pending(current)) { |
| 105 | ret = -EINTR; |
| 106 | break; |
| 107 | } |
| 108 | schedule(); |
| 109 | } |
| 110 | |
| 111 | finish_wait(&slogk_dev->writers_wq, &write_wait); |
| 112 | if (ret) |
| 113 | return NULL; |
| 114 | |
| 115 | idx = slogk_dev->write_idx; |
| 116 | slogk_dev->write_idx = |
| 117 | (slogk_dev->write_idx + 1) % slogk_dev->num_tot_blks; |
| 118 | slogk_dev->num_write_avail_blks--; |
| 119 | slogk_dev->num_write_in_prog_blks++; |
| 120 | slogk_dev->num_writers++; |
| 121 | |
| 122 | blk = &slogk_dev->ring[idx]; |
| 123 | /*mark block invalid*/ |
| 124 | blk->status = 0x0; |
| 125 | mutex_unlock(&slogk_dev->lock); |
| 126 | } |
| 127 | |
| 128 | blk->version = OBSERVER_VERSION; |
| 129 | blk->pid = current->tgid; |
| 130 | blk->tid = current->pid; |
| 131 | blk->uid = (current_uid()).val; |
| 132 | blk->sec = now.tv_sec; |
| 133 | blk->nsec = now.tv_nsec; |
| 134 | strlcpy(blk->appname, current->comm, TASK_COMM_LEN); |
| 135 | time_to_tm(now.tv_sec, 0, &ts); |
| 136 | ts.tm_year += YEAR_BASE; |
| 137 | ts.tm_mon += 1; |
| 138 | |
| 139 | snprintf(blk->ts, TS_SIZE, "%04ld-%02d-%02d %02d:%02d:%02d", |
| 140 | ts.tm_year, ts.tm_mon, ts.tm_mday, |
| 141 | ts.tm_hour, ts.tm_min, ts.tm_sec); |
| 142 | |
| 143 | *buf = blk->payload.msg; |
| 144 | |
| 145 | return blk; |
| 146 | } |
| 147 | |
| 148 | void seemp_logk_kernel_end_record(void *blck) |
| 149 | { |
| 150 | struct seemp_logk_blk *blk = (struct seemp_logk_blk *)blck; |
| 151 | |
| 152 | if (blk) { |
| 153 | /*update status at the very end*/ |
| 154 | blk->status |= 0x1; |
| 155 | blk->uid = (current_uid()).val; |
| 156 | |
| 157 | ringbuf_finish_writer(slogk_dev, blk); |
| 158 | } |
| 159 | } |
| 160 | |
| 161 | static int seemp_logk_usr_record(const char __user *buf, size_t count) |
| 162 | { |
| 163 | struct seemp_logk_blk *blk; |
| 164 | struct seemp_logk_blk usr_blk; |
| 165 | struct seemp_logk_blk *local_blk; |
| 166 | struct timespec now; |
| 167 | struct tm ts; |
| 168 | int idx, ret; |
| 169 | |
| 170 | DEFINE_WAIT(write_wait); |
| 171 | |
| 172 | if (buf) { |
| 173 | local_blk = (struct seemp_logk_blk *)buf; |
| 174 | if (copy_from_user(&usr_blk.pid, &local_blk->pid, |
| 175 | sizeof(usr_blk.pid)) != 0) |
| 176 | return -EFAULT; |
| 177 | if (copy_from_user(&usr_blk.tid, &local_blk->tid, |
| 178 | sizeof(usr_blk.tid)) != 0) |
| 179 | return -EFAULT; |
| 180 | if (copy_from_user(&usr_blk.uid, &local_blk->uid, |
| 181 | sizeof(usr_blk.uid)) != 0) |
| 182 | return -EFAULT; |
| 183 | if (copy_from_user(&usr_blk.len, &local_blk->len, |
| 184 | sizeof(usr_blk.len)) != 0) |
| 185 | return -EFAULT; |
| 186 | if (copy_from_user(&usr_blk.payload, &local_blk->payload, |
| 187 | sizeof(struct blk_payload)) != 0) |
| 188 | return -EFAULT; |
| 189 | } else { |
| 190 | return -EFAULT; |
| 191 | } |
| 192 | idx = ret = 0; |
| 193 | now = current_kernel_time(); |
| 194 | blk = ringbuf_fetch_wr_block(slogk_dev); |
| 195 | if (!blk) { |
| 196 | if (!block_apps) |
| 197 | return 0; |
| 198 | while (1) { |
| 199 | mutex_lock(&slogk_dev->lock); |
| 200 | prepare_to_wait(&slogk_dev->writers_wq, |
| 201 | &write_wait, |
| 202 | TASK_INTERRUPTIBLE); |
| 203 | ret = (slogk_dev->num_write_avail_blks <= 0); |
| 204 | if (!ret) |
| 205 | break; |
| 206 | mutex_unlock(&slogk_dev->lock); |
| 207 | if (signal_pending(current)) { |
| 208 | ret = -EINTR; |
| 209 | break; |
| 210 | } |
| 211 | schedule(); |
| 212 | } |
| 213 | finish_wait(&slogk_dev->writers_wq, &write_wait); |
| 214 | if (ret) |
| 215 | return -EINTR; |
| 216 | |
| 217 | idx = slogk_dev->write_idx; |
| 218 | slogk_dev->write_idx = |
| 219 | (slogk_dev->write_idx + 1) % slogk_dev->num_tot_blks; |
| 220 | slogk_dev->num_write_avail_blks--; |
| 221 | slogk_dev->num_write_in_prog_blks++; |
| 222 | slogk_dev->num_writers++; |
| 223 | blk = &slogk_dev->ring[idx]; |
| 224 | /*mark block invalid*/ |
| 225 | blk->status = 0x0; |
| 226 | mutex_unlock(&slogk_dev->lock); |
| 227 | } |
| 228 | if (usr_blk.len > sizeof(struct blk_payload)-1) |
| 229 | usr_blk.len = sizeof(struct blk_payload)-1; |
| 230 | |
| 231 | memcpy(&blk->payload, &usr_blk.payload, sizeof(struct blk_payload)); |
| 232 | blk->pid = usr_blk.pid; |
| 233 | blk->uid = usr_blk.uid; |
| 234 | blk->tid = usr_blk.tid; |
| 235 | blk->sec = now.tv_sec; |
| 236 | blk->nsec = now.tv_nsec; |
| 237 | time_to_tm(now.tv_sec, 0, &ts); |
| 238 | ts.tm_year += YEAR_BASE; |
| 239 | ts.tm_mon += 1; |
| 240 | snprintf(blk->ts, TS_SIZE, "%02ld-%02d-%02d %02d:%02d:%02d", |
| 241 | ts.tm_year, ts.tm_mon, ts.tm_mday, |
| 242 | ts.tm_hour, ts.tm_min, ts.tm_sec); |
| 243 | strlcpy(blk->appname, current->comm, TASK_COMM_LEN); |
| 244 | blk->status |= 0x1; |
| 245 | ringbuf_finish_writer(slogk_dev, blk); |
| 246 | return ret; |
| 247 | } |
| 248 | |
| 249 | static void seemp_logk_attach(void) |
| 250 | { |
| 251 | seemp_logk_kernel_end = seemp_logk_kernel_end_record; |
| 252 | seemp_logk_kernel_begin = seemp_logk_kernel_start_record; |
| 253 | } |
| 254 | |
| 255 | static void seemp_logk_detach(void) |
| 256 | { |
| 257 | seemp_logk_kernel_begin = NULL; |
| 258 | seemp_logk_kernel_end = NULL; |
| 259 | } |
| 260 | |
| 261 | static ssize_t |
| 262 | seemp_logk_write(struct file *file, const char __user *buf, size_t count, |
| 263 | loff_t *ppos) |
| 264 | { |
| 265 | return seemp_logk_usr_record(buf, count); |
| 266 | } |
| 267 | |
| 268 | static int |
| 269 | seemp_logk_open(struct inode *inode, struct file *filp) |
| 270 | { |
| 271 | int ret; |
| 272 | |
| 273 | /*disallow seeks on this file*/ |
| 274 | ret = nonseekable_open(inode, filp); |
| 275 | if (ret) { |
| 276 | pr_err("ret= %d\n", ret); |
| 277 | return ret; |
| 278 | } |
| 279 | |
| 280 | slogk_dev->minor = iminor(inode); |
| 281 | filp->private_data = slogk_dev; |
| 282 | |
| 283 | return 0; |
| 284 | } |
| 285 | |
| 286 | static bool seemp_logk_get_bit_from_vector(__u8 *pVec, __u32 index) |
| 287 | { |
| 288 | unsigned int byte_num = index/8; |
| 289 | unsigned int bit_num = index%8; |
| 290 | unsigned char byte; |
| 291 | |
| 292 | if (DIV_ROUND_UP(index, 8) > MASK_BUFFER_SIZE) |
| 293 | return false; |
| 294 | |
| 295 | byte = pVec[byte_num]; |
| 296 | |
| 297 | return !(byte & (1 << bit_num)); |
| 298 | } |
| 299 | |
| 300 | static long seemp_logk_ioctl(struct file *filp, unsigned int cmd, |
| 301 | unsigned long arg) |
| 302 | { |
| 303 | struct seemp_logk_dev *sdev; |
| 304 | int ret; |
| 305 | |
| 306 | sdev = (struct seemp_logk_dev *) filp->private_data; |
| 307 | |
| 308 | if (cmd == SEEMP_CMD_RESERVE_RDBLKS) { |
| 309 | return seemp_logk_reserve_rdblks(sdev, arg); |
| 310 | } else if (cmd == SEEMP_CMD_RELEASE_RDBLKS) { |
| 311 | mutex_lock(&sdev->lock); |
| 312 | sdev->read_idx = (sdev->read_idx + sdev->num_read_in_prog_blks) |
| 313 | % sdev->num_tot_blks; |
| 314 | sdev->num_write_avail_blks += sdev->num_read_in_prog_blks; |
| 315 | ret = sdev->num_read_in_prog_blks; |
| 316 | sdev->num_read_in_prog_blks = 0; |
| 317 | /*wake up any waiting writers*/ |
| 318 | mutex_unlock(&sdev->lock); |
| 319 | if (ret && block_apps) |
| 320 | wake_up_interruptible(&sdev->writers_wq); |
| 321 | } else if (cmd == SEEMP_CMD_GET_RINGSZ) { |
| 322 | if (copy_to_user((unsigned int *)arg, &sdev->ring_sz, |
| 323 | sizeof(unsigned int))) |
| 324 | return -EFAULT; |
| 325 | } else if (cmd == SEEMP_CMD_GET_BLKSZ) { |
| 326 | if (copy_to_user((unsigned int *)arg, &sdev->blk_sz, |
| 327 | sizeof(unsigned int))) |
| 328 | return -EFAULT; |
| 329 | } else if (cmd == SEEMP_CMD_SET_MASK) { |
| 330 | return seemp_logk_set_mask(arg); |
| 331 | } else if (cmd == SEEMP_CMD_SET_MAPPING) { |
| 332 | return seemp_logk_set_mapping(arg); |
| 333 | } else if (cmd == SEEMP_CMD_CHECK_FILTER) { |
| 334 | return seemp_logk_check_filter(arg); |
| 335 | } |
| 336 | pr_err("Invalid Request %X\n", cmd); |
| 337 | return -ENOIOCTLCMD; |
| 338 | } |
| 339 | |
| 340 | static long seemp_logk_reserve_rdblks( |
| 341 | struct seemp_logk_dev *sdev, unsigned long arg) |
| 342 | { |
| 343 | int ret; |
| 344 | struct read_range rrange; |
| 345 | |
| 346 | DEFINE_WAIT(read_wait); |
| 347 | |
| 348 | mutex_lock(&sdev->lock); |
| 349 | if (sdev->num_writers > 0 || sdev->num_read_avail_blks <= 0) { |
| 350 | ret = -EPERM; |
| 351 | pr_debug("(reserve): blocking, cannot read.\n"); |
| 352 | pr_debug("num_writers=%d num_read_avail_blks=%d\n", |
| 353 | sdev->num_writers, |
| 354 | sdev->num_read_avail_blks); |
| 355 | mutex_unlock(&sdev->lock); |
| 356 | /* |
| 357 | * unlock the device |
| 358 | * wait on a wait queue |
| 359 | * after wait, grab the dev lock again |
| 360 | */ |
| 361 | while (1) { |
| 362 | mutex_lock(&sdev->lock); |
| 363 | prepare_to_wait(&sdev->readers_wq, &read_wait, |
| 364 | TASK_INTERRUPTIBLE); |
| 365 | ret = (sdev->num_writers > 0 || |
| 366 | sdev->num_read_avail_blks <= 0); |
| 367 | if (!ret) { |
| 368 | /*don't have to wait*/ |
| 369 | break; |
| 370 | } |
| 371 | mutex_unlock(&sdev->lock); |
| 372 | if (signal_pending(current)) { |
| 373 | ret = -EINTR; |
| 374 | break; |
| 375 | } |
| 376 | schedule(); |
| 377 | } |
| 378 | |
| 379 | finish_wait(&sdev->readers_wq, &read_wait); |
| 380 | if (ret) |
| 381 | return -EINTR; |
| 382 | } |
| 383 | |
| 384 | /*sdev->lock is held at this point*/ |
| 385 | sdev->num_read_in_prog_blks = sdev->num_read_avail_blks; |
| 386 | sdev->num_read_avail_blks = 0; |
| 387 | rrange.start_idx = sdev->read_idx; |
| 388 | rrange.num = sdev->num_read_in_prog_blks; |
| 389 | mutex_unlock(&sdev->lock); |
| 390 | |
| 391 | if (copy_to_user((unsigned int *)arg, &rrange, |
| 392 | sizeof(struct read_range))) |
| 393 | return -EFAULT; |
| 394 | |
| 395 | return 0; |
| 396 | } |
| 397 | |
| 398 | static long seemp_logk_set_mask(unsigned long arg) |
| 399 | { |
| 400 | __u8 buffer[256]; |
| 401 | int i; |
| 402 | unsigned int num_elements; |
| 403 | |
| 404 | if (copy_from_user(&num_elements, |
| 405 | (unsigned int __user *) arg, sizeof(unsigned int))) |
| 406 | return -EFAULT; |
| 407 | |
| 408 | read_lock(&filter_lock); |
| 409 | if (num_sources == 0) { |
| 410 | read_unlock(&filter_lock); |
| 411 | return -EINVAL; |
| 412 | } |
| 413 | |
| 414 | if (num_elements == 0 || |
| 415 | DIV_ROUND_UP(num_sources, 8) > MASK_BUFFER_SIZE) { |
| 416 | read_unlock(&filter_lock); |
| 417 | return -EINVAL; |
| 418 | } |
| 419 | |
| 420 | if (copy_from_user(buffer, |
| 421 | (__u8 *)arg, DIV_ROUND_UP(num_sources, 8))) { |
| 422 | read_unlock(&filter_lock); |
| 423 | return -EFAULT; |
| 424 | } |
| 425 | |
| 426 | read_unlock(&filter_lock); |
| 427 | write_lock(&filter_lock); |
| 428 | if (num_elements != num_sources) { |
| 429 | write_unlock(&filter_lock); |
| 430 | return -EPERM; |
| 431 | } |
| 432 | |
| 433 | for (i = 0; i < num_sources; i++) { |
| 434 | pmask[i].isOn = |
| 435 | seemp_logk_get_bit_from_vector( |
| 436 | (__u8 *)buffer, i); |
| 437 | } |
| 438 | write_unlock(&filter_lock); |
| 439 | return 0; |
| 440 | } |
| 441 | |
| 442 | static long seemp_logk_set_mapping(unsigned long arg) |
| 443 | { |
| 444 | __u32 num_elements; |
| 445 | __u32 *pbuffer; |
| 446 | int i; |
| 447 | struct seemp_source_mask *pnewmask; |
| 448 | |
| 449 | if (copy_from_user(&num_elements, |
| 450 | (__u32 __user *)arg, sizeof(__u32))) |
| 451 | return -EFAULT; |
| 452 | |
| 453 | if ((num_elements == 0) || (num_elements > |
| 454 | (UINT_MAX / sizeof(struct seemp_source_mask)))) |
| 455 | return -EFAULT; |
| 456 | |
| 457 | write_lock(&filter_lock); |
| 458 | if (pmask != NULL) { |
| 459 | /* |
| 460 | * Mask is getting set again. |
| 461 | * seemp_core was probably restarted. |
| 462 | */ |
| 463 | struct seemp_source_mask *ptempmask; |
| 464 | |
| 465 | num_sources = 0; |
| 466 | ptempmask = pmask; |
| 467 | pmask = NULL; |
| 468 | kfree(ptempmask); |
| 469 | } |
| 470 | write_unlock(&filter_lock); |
| 471 | pbuffer = kmalloc(sizeof(struct seemp_source_mask) |
| 472 | * num_elements, GFP_KERNEL); |
| 473 | if (pbuffer == NULL) |
| 474 | return -ENOMEM; |
| 475 | |
| 476 | /* |
| 477 | * Use our new table as scratch space for now. |
| 478 | * We copy an ordered list of hash values into our buffer. |
| 479 | */ |
| 480 | if (copy_from_user(pbuffer, &((__u32 __user *)arg)[1], |
| 481 | num_elements*sizeof(unsigned int))) { |
| 482 | kfree(pbuffer); |
| 483 | return -EFAULT; |
| 484 | } |
| 485 | /* |
| 486 | * We arrange the user data into a more usable form. |
| 487 | * This is done in-place. |
| 488 | */ |
| 489 | pnewmask = (struct seemp_source_mask *) pbuffer; |
| 490 | for (i = num_elements - 1; i >= 0; i--) { |
| 491 | pnewmask[i].hash = pbuffer[i]; |
| 492 | /* Observer is off by default*/ |
| 493 | pnewmask[i].isOn = 0; |
| 494 | } |
| 495 | write_lock(&filter_lock); |
| 496 | pmask = pnewmask; |
| 497 | num_sources = num_elements; |
| 498 | write_unlock(&filter_lock); |
| 499 | return 0; |
| 500 | } |
| 501 | |
| 502 | static long seemp_logk_check_filter(unsigned long arg) |
| 503 | { |
| 504 | int i; |
| 505 | unsigned int hash = (unsigned int) arg; |
| 506 | |
| 507 | /* |
| 508 | * This lock may be a bit long. |
| 509 | * If it is a problem, it can be fixed. |
| 510 | */ |
| 511 | read_lock(&filter_lock); |
| 512 | for (i = 0; i < num_sources; i++) { |
| 513 | if (hash == pmask[i].hash) { |
| 514 | int result = pmask[i].isOn; |
| 515 | |
| 516 | read_unlock(&filter_lock); |
| 517 | return result; |
| 518 | } |
| 519 | } |
| 520 | read_unlock(&filter_lock); |
| 521 | return 0; |
| 522 | } |
| 523 | |
| 524 | static int seemp_logk_mmap(struct file *filp, |
| 525 | struct vm_area_struct *vma) |
| 526 | { |
| 527 | int ret; |
| 528 | char *vptr; |
| 529 | unsigned long length, pfn; |
| 530 | unsigned long start = vma->vm_start; |
| 531 | |
| 532 | length = vma->vm_end - vma->vm_start; |
| 533 | |
| 534 | if (length > (unsigned long) slogk_dev->ring_sz) { |
| 535 | pr_err("len check failed\n"); |
| 536 | return -EIO; |
| 537 | } |
| 538 | |
| 539 | vma->vm_flags |= VM_RESERVED | VM_SHARED; |
| 540 | vptr = (char *) slogk_dev->ring; |
| 541 | ret = 0; |
| 542 | |
| 543 | if (kmalloc_flag) { |
| 544 | ret = remap_pfn_range(vma, |
| 545 | start, |
| 546 | virt_to_phys((void *) |
| 547 | ((unsigned long)slogk_dev->ring)) >> PAGE_SHIFT, |
| 548 | length, |
| 549 | vma->vm_page_prot); |
| 550 | if (ret != 0) { |
| 551 | pr_err("remap_pfn_range() fails with ret = %d\n", |
| 552 | ret); |
| 553 | return -EAGAIN; |
| 554 | } |
| 555 | } else { |
| 556 | while (length > 0) { |
| 557 | pfn = vmalloc_to_pfn(vptr); |
| 558 | |
| 559 | ret = remap_pfn_range(vma, start, pfn, PAGE_SIZE, |
| 560 | vma->vm_page_prot); |
| 561 | if (ret < 0) { |
| 562 | pr_err("remap_pfn_range() fails with ret = %d\n", |
| 563 | ret); |
| 564 | return ret; |
| 565 | } |
| 566 | start += PAGE_SIZE; |
| 567 | vptr += PAGE_SIZE; |
| 568 | length -= PAGE_SIZE; |
| 569 | } |
| 570 | } |
| 571 | |
| 572 | return 0; |
| 573 | } |
| 574 | |
| 575 | static const struct file_operations seemp_logk_fops = { |
| 576 | .write = seemp_logk_write, |
| 577 | .open = seemp_logk_open, |
| 578 | .unlocked_ioctl = seemp_logk_ioctl, |
| 579 | .compat_ioctl = seemp_logk_ioctl, |
| 580 | .mmap = seemp_logk_mmap, |
| 581 | }; |
| 582 | |
| 583 | __init int seemp_logk_init(void) |
| 584 | { |
| 585 | int ret; |
| 586 | int devno = 0; |
| 587 | |
| 588 | num_sources = 0; |
| 589 | kmalloc_flag = 0; |
| 590 | block_apps = 0; |
| 591 | pmask = NULL; |
| 592 | |
| 593 | if (kmalloc_flag && ring_sz > FOUR_MB) { |
| 594 | pr_err("kmalloc cannot allocate > 4MB\n"); |
| 595 | return -ENOMEM; |
| 596 | } |
| 597 | |
| 598 | ring_sz = ring_sz * SZ_1M; |
| 599 | if (ring_sz <= 0) { |
| 600 | pr_err("Too small a ring_sz=%d\n", ring_sz); |
| 601 | return -EINVAL; |
| 602 | } |
| 603 | |
| 604 | slogk_dev = kmalloc(sizeof(*slogk_dev), GFP_KERNEL); |
| 605 | if (slogk_dev == NULL) |
| 606 | return -ENOMEM; |
| 607 | |
| 608 | slogk_dev->ring_sz = ring_sz; |
| 609 | slogk_dev->blk_sz = sizeof(struct seemp_logk_blk); |
| 610 | /*initialize ping-pong buffers*/ |
| 611 | ret = ringbuf_init(slogk_dev); |
| 612 | if (ret < 0) { |
| 613 | pr_err("Init Failed, ret = %d\n", ret); |
| 614 | goto pingpong_fail; |
| 615 | } |
| 616 | |
| 617 | ret = alloc_chrdev_region(&devno, 0, seemp_LOGK_NUM_DEVS, |
| 618 | seemp_LOGK_DEV_NAME); |
| 619 | if (ret < 0) { |
| 620 | pr_err("alloc_chrdev_region failed with ret = %d\n", |
| 621 | ret); |
| 622 | goto register_fail; |
| 623 | } |
| 624 | |
| 625 | slogk_dev->major = MAJOR(devno); |
| 626 | |
| 627 | pr_debug("logk: major# = %d\n", slogk_dev->major); |
| 628 | |
| 629 | cl = class_create(THIS_MODULE, seemp_LOGK_DEV_NAME); |
| 630 | if (cl == NULL) { |
| 631 | pr_err("class create failed"); |
| 632 | goto cdev_fail; |
| 633 | } |
| 634 | if (device_create(cl, NULL, devno, NULL, |
| 635 | seemp_LOGK_DEV_NAME) == NULL) { |
| 636 | pr_err("device create failed"); |
| 637 | goto class_destroy_fail; |
| 638 | } |
| 639 | cdev_init(&(slogk_dev->cdev), &seemp_logk_fops); |
| 640 | |
| 641 | slogk_dev->cdev.owner = THIS_MODULE; |
| 642 | ret = cdev_add(&(slogk_dev->cdev), MKDEV(slogk_dev->major, 0), 1); |
| 643 | if (ret) { |
| 644 | pr_err("cdev_add failed with ret = %d", ret); |
| 645 | goto class_destroy_fail; |
| 646 | } |
| 647 | |
| 648 | seemp_logk_attach(); |
| 649 | mutex_init(&slogk_dev->lock); |
| 650 | init_waitqueue_head(&slogk_dev->readers_wq); |
| 651 | init_waitqueue_head(&slogk_dev->writers_wq); |
| 652 | rwlock_init(&filter_lock); |
| 653 | return 0; |
| 654 | class_destroy_fail: |
| 655 | class_destroy(cl); |
| 656 | cdev_fail: |
| 657 | unregister_chrdev_region(devno, seemp_LOGK_NUM_DEVS); |
| 658 | register_fail: |
| 659 | ringbuf_cleanup(slogk_dev); |
| 660 | pingpong_fail: |
| 661 | kfree(slogk_dev); |
| 662 | return -EPERM; |
| 663 | } |
| 664 | |
| 665 | __exit void seemp_logk_cleanup(void) |
| 666 | { |
| 667 | dev_t devno = MKDEV(slogk_dev->major, slogk_dev->minor); |
| 668 | |
| 669 | seemp_logk_detach(); |
| 670 | |
| 671 | cdev_del(&slogk_dev->cdev); |
| 672 | |
| 673 | unregister_chrdev_region(devno, seemp_LOGK_NUM_DEVS); |
| 674 | ringbuf_cleanup(slogk_dev); |
| 675 | kfree(slogk_dev); |
| 676 | |
| 677 | if (pmask != NULL) { |
| 678 | kfree(pmask); |
| 679 | pmask = NULL; |
| 680 | } |
| 681 | } |
| 682 | |
| 683 | module_init(seemp_logk_init); |
| 684 | module_exit(seemp_logk_cleanup); |
| 685 | |
| 686 | MODULE_LICENSE("GPL v2"); |
| 687 | MODULE_DESCRIPTION("seemp Observer"); |
| 688 | |