Steven Rostedt (VMware) | 6954e41 | 2021-09-23 21:03:49 -0400 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | /* |
| 3 | * Copyright (C) 2021 VMware Inc, Steven Rostedt <rostedt@goodmis.org> |
| 4 | */ |
Steven Rostedt (VMware) | 8d6e9098 | 2021-09-23 22:20:57 -0400 | [diff] [blame] | 5 | #include <linux/spinlock.h> |
| 6 | #include <linux/irq_work.h> |
Steven Rostedt (VMware) | 6954e41 | 2021-09-23 21:03:49 -0400 | [diff] [blame] | 7 | #include <linux/slab.h> |
| 8 | #include "trace.h" |
| 9 | |
Steven Rostedt (VMware) | 8d6e9098 | 2021-09-23 22:20:57 -0400 | [diff] [blame] | 10 | /* See pid_list.h for details */ |
| 11 | |
| 12 | static inline union lower_chunk *get_lower_chunk(struct trace_pid_list *pid_list) |
| 13 | { |
| 14 | union lower_chunk *chunk; |
| 15 | |
| 16 | lockdep_assert_held(&pid_list->lock); |
| 17 | |
| 18 | if (!pid_list->lower_list) |
| 19 | return NULL; |
| 20 | |
| 21 | chunk = pid_list->lower_list; |
| 22 | pid_list->lower_list = chunk->next; |
| 23 | pid_list->free_lower_chunks--; |
| 24 | WARN_ON_ONCE(pid_list->free_lower_chunks < 0); |
| 25 | chunk->next = NULL; |
| 26 | /* |
| 27 | * If a refill needs to happen, it can not happen here |
| 28 | * as the scheduler run queue locks are held. |
| 29 | */ |
| 30 | if (pid_list->free_lower_chunks <= CHUNK_REALLOC) |
| 31 | irq_work_queue(&pid_list->refill_irqwork); |
| 32 | |
| 33 | return chunk; |
| 34 | } |
| 35 | |
| 36 | static inline union upper_chunk *get_upper_chunk(struct trace_pid_list *pid_list) |
| 37 | { |
| 38 | union upper_chunk *chunk; |
| 39 | |
| 40 | lockdep_assert_held(&pid_list->lock); |
| 41 | |
| 42 | if (!pid_list->upper_list) |
| 43 | return NULL; |
| 44 | |
| 45 | chunk = pid_list->upper_list; |
| 46 | pid_list->upper_list = chunk->next; |
| 47 | pid_list->free_upper_chunks--; |
| 48 | WARN_ON_ONCE(pid_list->free_upper_chunks < 0); |
| 49 | chunk->next = NULL; |
| 50 | /* |
| 51 | * If a refill needs to happen, it can not happen here |
| 52 | * as the scheduler run queue locks are held. |
| 53 | */ |
| 54 | if (pid_list->free_upper_chunks <= CHUNK_REALLOC) |
| 55 | irq_work_queue(&pid_list->refill_irqwork); |
| 56 | |
| 57 | return chunk; |
| 58 | } |
| 59 | |
| 60 | static inline void put_lower_chunk(struct trace_pid_list *pid_list, |
| 61 | union lower_chunk *chunk) |
| 62 | { |
| 63 | lockdep_assert_held(&pid_list->lock); |
| 64 | |
| 65 | chunk->next = pid_list->lower_list; |
| 66 | pid_list->lower_list = chunk; |
| 67 | pid_list->free_lower_chunks++; |
| 68 | } |
| 69 | |
| 70 | static inline void put_upper_chunk(struct trace_pid_list *pid_list, |
| 71 | union upper_chunk *chunk) |
| 72 | { |
| 73 | lockdep_assert_held(&pid_list->lock); |
| 74 | |
| 75 | chunk->next = pid_list->upper_list; |
| 76 | pid_list->upper_list = chunk; |
| 77 | pid_list->free_upper_chunks++; |
| 78 | } |
| 79 | |
| 80 | static inline bool upper_empty(union upper_chunk *chunk) |
| 81 | { |
| 82 | /* |
| 83 | * If chunk->data has no lower chunks, it will be the same |
| 84 | * as a zeroed bitmask. Use find_first_bit() to test it |
| 85 | * and if it doesn't find any bits set, then the array |
| 86 | * is empty. |
| 87 | */ |
| 88 | int bit = find_first_bit((unsigned long *)chunk->data, |
| 89 | sizeof(chunk->data) * 8); |
| 90 | return bit >= sizeof(chunk->data) * 8; |
| 91 | } |
| 92 | |
| 93 | static inline int pid_split(unsigned int pid, unsigned int *upper1, |
| 94 | unsigned int *upper2, unsigned int *lower) |
| 95 | { |
| 96 | /* MAX_PID should cover all pids */ |
| 97 | BUILD_BUG_ON(MAX_PID < PID_MAX_LIMIT); |
| 98 | |
| 99 | /* In case a bad pid is passed in, then fail */ |
| 100 | if (unlikely(pid >= MAX_PID)) |
| 101 | return -1; |
| 102 | |
| 103 | *upper1 = (pid >> UPPER1_SHIFT) & UPPER_MASK; |
| 104 | *upper2 = (pid >> UPPER2_SHIFT) & UPPER_MASK; |
| 105 | *lower = pid & LOWER_MASK; |
| 106 | |
| 107 | return 0; |
| 108 | } |
| 109 | |
| 110 | static inline unsigned int pid_join(unsigned int upper1, |
| 111 | unsigned int upper2, unsigned int lower) |
| 112 | { |
| 113 | return ((upper1 & UPPER_MASK) << UPPER1_SHIFT) | |
| 114 | ((upper2 & UPPER_MASK) << UPPER2_SHIFT) | |
| 115 | (lower & LOWER_MASK); |
| 116 | } |
| 117 | |
Steven Rostedt (VMware) | 6954e41 | 2021-09-23 21:03:49 -0400 | [diff] [blame] | 118 | /** |
| 119 | * trace_pid_list_is_set - test if the pid is set in the list |
| 120 | * @pid_list: The pid list to test |
| 121 | * @pid: The pid to to see if set in the list. |
| 122 | * |
| 123 | * Tests if @pid is is set in the @pid_list. This is usually called |
| 124 | * from the scheduler when a task is scheduled. Its pid is checked |
| 125 | * if it should be traced or not. |
| 126 | * |
| 127 | * Return true if the pid is in the list, false otherwise. |
| 128 | */ |
| 129 | bool trace_pid_list_is_set(struct trace_pid_list *pid_list, unsigned int pid) |
| 130 | { |
Steven Rostedt (VMware) | 8d6e9098 | 2021-09-23 22:20:57 -0400 | [diff] [blame] | 131 | union upper_chunk *upper_chunk; |
| 132 | union lower_chunk *lower_chunk; |
| 133 | unsigned long flags; |
| 134 | unsigned int upper1; |
| 135 | unsigned int upper2; |
| 136 | unsigned int lower; |
| 137 | bool ret = false; |
| 138 | |
| 139 | if (!pid_list) |
Steven Rostedt (VMware) | 6954e41 | 2021-09-23 21:03:49 -0400 | [diff] [blame] | 140 | return false; |
| 141 | |
Steven Rostedt (VMware) | 8d6e9098 | 2021-09-23 22:20:57 -0400 | [diff] [blame] | 142 | if (pid_split(pid, &upper1, &upper2, &lower) < 0) |
| 143 | return false; |
| 144 | |
| 145 | raw_spin_lock_irqsave(&pid_list->lock, flags); |
| 146 | upper_chunk = pid_list->upper[upper1]; |
| 147 | if (upper_chunk) { |
| 148 | lower_chunk = upper_chunk->data[upper2]; |
| 149 | if (lower_chunk) |
| 150 | ret = test_bit(lower, lower_chunk->data); |
| 151 | } |
| 152 | raw_spin_unlock_irqrestore(&pid_list->lock, flags); |
| 153 | |
| 154 | return ret; |
Steven Rostedt (VMware) | 6954e41 | 2021-09-23 21:03:49 -0400 | [diff] [blame] | 155 | } |
| 156 | |
| 157 | /** |
| 158 | * trace_pid_list_set - add a pid to the list |
| 159 | * @pid_list: The pid list to add the @pid to. |
| 160 | * @pid: The pid to add. |
| 161 | * |
| 162 | * Adds @pid to @pid_list. This is usually done explicitly by a user |
| 163 | * adding a task to be traced, or indirectly by the fork function |
| 164 | * when children should be traced and a task's pid is in the list. |
| 165 | * |
| 166 | * Return 0 on success, negative otherwise. |
| 167 | */ |
| 168 | int trace_pid_list_set(struct trace_pid_list *pid_list, unsigned int pid) |
| 169 | { |
Steven Rostedt (VMware) | 8d6e9098 | 2021-09-23 22:20:57 -0400 | [diff] [blame] | 170 | union upper_chunk *upper_chunk; |
| 171 | union lower_chunk *lower_chunk; |
| 172 | unsigned long flags; |
| 173 | unsigned int upper1; |
| 174 | unsigned int upper2; |
| 175 | unsigned int lower; |
| 176 | int ret; |
| 177 | |
| 178 | if (!pid_list) |
| 179 | return -ENODEV; |
| 180 | |
| 181 | if (pid_split(pid, &upper1, &upper2, &lower) < 0) |
Steven Rostedt (VMware) | 6954e41 | 2021-09-23 21:03:49 -0400 | [diff] [blame] | 182 | return -EINVAL; |
| 183 | |
Steven Rostedt (VMware) | 8d6e9098 | 2021-09-23 22:20:57 -0400 | [diff] [blame] | 184 | raw_spin_lock_irqsave(&pid_list->lock, flags); |
| 185 | upper_chunk = pid_list->upper[upper1]; |
| 186 | if (!upper_chunk) { |
| 187 | upper_chunk = get_upper_chunk(pid_list); |
| 188 | if (!upper_chunk) { |
| 189 | ret = -ENOMEM; |
| 190 | goto out; |
| 191 | } |
| 192 | pid_list->upper[upper1] = upper_chunk; |
| 193 | } |
| 194 | lower_chunk = upper_chunk->data[upper2]; |
| 195 | if (!lower_chunk) { |
| 196 | lower_chunk = get_lower_chunk(pid_list); |
| 197 | if (!lower_chunk) { |
| 198 | ret = -ENOMEM; |
| 199 | goto out; |
| 200 | } |
| 201 | upper_chunk->data[upper2] = lower_chunk; |
| 202 | } |
| 203 | set_bit(lower, lower_chunk->data); |
| 204 | ret = 0; |
| 205 | out: |
| 206 | raw_spin_unlock_irqrestore(&pid_list->lock, flags); |
| 207 | return ret; |
Steven Rostedt (VMware) | 6954e41 | 2021-09-23 21:03:49 -0400 | [diff] [blame] | 208 | } |
| 209 | |
| 210 | /** |
| 211 | * trace_pid_list_clear - remove a pid from the list |
| 212 | * @pid_list: The pid list to remove the @pid from. |
| 213 | * @pid: The pid to remove. |
| 214 | * |
| 215 | * Removes @pid from @pid_list. This is usually done explicitly by a user |
| 216 | * removing tasks from tracing, or indirectly by the exit function |
| 217 | * when a task that is set to be traced exits. |
| 218 | * |
| 219 | * Return 0 on success, negative otherwise. |
| 220 | */ |
| 221 | int trace_pid_list_clear(struct trace_pid_list *pid_list, unsigned int pid) |
| 222 | { |
Steven Rostedt (VMware) | 8d6e9098 | 2021-09-23 22:20:57 -0400 | [diff] [blame] | 223 | union upper_chunk *upper_chunk; |
| 224 | union lower_chunk *lower_chunk; |
| 225 | unsigned long flags; |
| 226 | unsigned int upper1; |
| 227 | unsigned int upper2; |
| 228 | unsigned int lower; |
| 229 | |
| 230 | if (!pid_list) |
| 231 | return -ENODEV; |
| 232 | |
| 233 | if (pid_split(pid, &upper1, &upper2, &lower) < 0) |
Steven Rostedt (VMware) | 6954e41 | 2021-09-23 21:03:49 -0400 | [diff] [blame] | 234 | return -EINVAL; |
| 235 | |
Steven Rostedt (VMware) | 8d6e9098 | 2021-09-23 22:20:57 -0400 | [diff] [blame] | 236 | raw_spin_lock_irqsave(&pid_list->lock, flags); |
| 237 | upper_chunk = pid_list->upper[upper1]; |
| 238 | if (!upper_chunk) |
| 239 | goto out; |
Steven Rostedt (VMware) | 6954e41 | 2021-09-23 21:03:49 -0400 | [diff] [blame] | 240 | |
Steven Rostedt (VMware) | 8d6e9098 | 2021-09-23 22:20:57 -0400 | [diff] [blame] | 241 | lower_chunk = upper_chunk->data[upper2]; |
| 242 | if (!lower_chunk) |
| 243 | goto out; |
| 244 | |
| 245 | clear_bit(lower, lower_chunk->data); |
| 246 | |
| 247 | /* if there's no more bits set, add it to the free list */ |
| 248 | if (find_first_bit(lower_chunk->data, LOWER_MAX) >= LOWER_MAX) { |
| 249 | put_lower_chunk(pid_list, lower_chunk); |
| 250 | upper_chunk->data[upper2] = NULL; |
| 251 | if (upper_empty(upper_chunk)) { |
| 252 | put_upper_chunk(pid_list, upper_chunk); |
| 253 | pid_list->upper[upper1] = NULL; |
| 254 | } |
| 255 | } |
| 256 | out: |
| 257 | raw_spin_unlock_irqrestore(&pid_list->lock, flags); |
Steven Rostedt (VMware) | 6954e41 | 2021-09-23 21:03:49 -0400 | [diff] [blame] | 258 | return 0; |
| 259 | } |
| 260 | |
| 261 | /** |
| 262 | * trace_pid_list_next - return the next pid in the list |
| 263 | * @pid_list: The pid list to examine. |
| 264 | * @pid: The pid to start from |
| 265 | * @next: The pointer to place the pid that is set starting from @pid. |
| 266 | * |
| 267 | * Looks for the next consecutive pid that is in @pid_list starting |
| 268 | * at the pid specified by @pid. If one is set (including @pid), then |
| 269 | * that pid is placed into @next. |
| 270 | * |
| 271 | * Return 0 when a pid is found, -1 if there are no more pids included. |
| 272 | */ |
| 273 | int trace_pid_list_next(struct trace_pid_list *pid_list, unsigned int pid, |
| 274 | unsigned int *next) |
| 275 | { |
Steven Rostedt (VMware) | 8d6e9098 | 2021-09-23 22:20:57 -0400 | [diff] [blame] | 276 | union upper_chunk *upper_chunk; |
| 277 | union lower_chunk *lower_chunk; |
| 278 | unsigned long flags; |
| 279 | unsigned int upper1; |
| 280 | unsigned int upper2; |
| 281 | unsigned int lower; |
Steven Rostedt (VMware) | 6954e41 | 2021-09-23 21:03:49 -0400 | [diff] [blame] | 282 | |
Steven Rostedt (VMware) | 8d6e9098 | 2021-09-23 22:20:57 -0400 | [diff] [blame] | 283 | if (!pid_list) |
| 284 | return -ENODEV; |
| 285 | |
| 286 | if (pid_split(pid, &upper1, &upper2, &lower) < 0) |
| 287 | return -EINVAL; |
| 288 | |
| 289 | raw_spin_lock_irqsave(&pid_list->lock, flags); |
| 290 | for (; upper1 <= UPPER_MASK; upper1++, upper2 = 0) { |
| 291 | upper_chunk = pid_list->upper[upper1]; |
| 292 | |
| 293 | if (!upper_chunk) |
| 294 | continue; |
| 295 | |
| 296 | for (; upper2 <= UPPER_MASK; upper2++, lower = 0) { |
| 297 | lower_chunk = upper_chunk->data[upper2]; |
| 298 | if (!lower_chunk) |
| 299 | continue; |
| 300 | |
| 301 | lower = find_next_bit(lower_chunk->data, LOWER_MAX, |
| 302 | lower); |
| 303 | if (lower < LOWER_MAX) |
| 304 | goto found; |
| 305 | } |
Steven Rostedt (VMware) | 6954e41 | 2021-09-23 21:03:49 -0400 | [diff] [blame] | 306 | } |
Steven Rostedt (VMware) | 8d6e9098 | 2021-09-23 22:20:57 -0400 | [diff] [blame] | 307 | |
| 308 | found: |
| 309 | raw_spin_unlock_irqrestore(&pid_list->lock, flags); |
| 310 | if (upper1 > UPPER_MASK) |
| 311 | return -1; |
| 312 | |
| 313 | *next = pid_join(upper1, upper2, lower); |
| 314 | return 0; |
Steven Rostedt (VMware) | 6954e41 | 2021-09-23 21:03:49 -0400 | [diff] [blame] | 315 | } |
| 316 | |
| 317 | /** |
| 318 | * trace_pid_list_first - return the first pid in the list |
| 319 | * @pid_list: The pid list to examine. |
| 320 | * @pid: The pointer to place the pid first found pid that is set. |
| 321 | * |
| 322 | * Looks for the first pid that is set in @pid_list, and places it |
| 323 | * into @pid if found. |
| 324 | * |
| 325 | * Return 0 when a pid is found, -1 if there are no pids set. |
| 326 | */ |
| 327 | int trace_pid_list_first(struct trace_pid_list *pid_list, unsigned int *pid) |
| 328 | { |
Steven Rostedt (VMware) | 8d6e9098 | 2021-09-23 22:20:57 -0400 | [diff] [blame] | 329 | return trace_pid_list_next(pid_list, 0, pid); |
| 330 | } |
Steven Rostedt (VMware) | 6954e41 | 2021-09-23 21:03:49 -0400 | [diff] [blame] | 331 | |
Steven Rostedt (VMware) | 8d6e9098 | 2021-09-23 22:20:57 -0400 | [diff] [blame] | 332 | static void pid_list_refill_irq(struct irq_work *iwork) |
| 333 | { |
| 334 | struct trace_pid_list *pid_list = container_of(iwork, struct trace_pid_list, |
| 335 | refill_irqwork); |
Steven Rostedt (VMware) | b30a779 | 2021-10-07 09:53:53 -0400 | [diff] [blame] | 336 | union upper_chunk *upper = NULL; |
| 337 | union lower_chunk *lower = NULL; |
Steven Rostedt (VMware) | 8d6e9098 | 2021-09-23 22:20:57 -0400 | [diff] [blame] | 338 | union upper_chunk **upper_next = &upper; |
| 339 | union lower_chunk **lower_next = &lower; |
| 340 | int upper_count; |
| 341 | int lower_count; |
| 342 | int ucnt = 0; |
| 343 | int lcnt = 0; |
Steven Rostedt (VMware) | 6954e41 | 2021-09-23 21:03:49 -0400 | [diff] [blame] | 344 | |
Steven Rostedt (VMware) | 8d6e9098 | 2021-09-23 22:20:57 -0400 | [diff] [blame] | 345 | again: |
| 346 | raw_spin_lock(&pid_list->lock); |
| 347 | upper_count = CHUNK_ALLOC - pid_list->free_upper_chunks; |
| 348 | lower_count = CHUNK_ALLOC - pid_list->free_lower_chunks; |
| 349 | raw_spin_unlock(&pid_list->lock); |
| 350 | |
| 351 | if (upper_count <= 0 && lower_count <= 0) |
| 352 | return; |
| 353 | |
| 354 | while (upper_count-- > 0) { |
| 355 | union upper_chunk *chunk; |
| 356 | |
| 357 | chunk = kzalloc(sizeof(*chunk), GFP_KERNEL); |
| 358 | if (!chunk) |
| 359 | break; |
| 360 | *upper_next = chunk; |
| 361 | upper_next = &chunk->next; |
| 362 | ucnt++; |
Steven Rostedt (VMware) | 6954e41 | 2021-09-23 21:03:49 -0400 | [diff] [blame] | 363 | } |
Steven Rostedt (VMware) | 8d6e9098 | 2021-09-23 22:20:57 -0400 | [diff] [blame] | 364 | |
| 365 | while (lower_count-- > 0) { |
| 366 | union lower_chunk *chunk; |
| 367 | |
| 368 | chunk = kzalloc(sizeof(*chunk), GFP_KERNEL); |
| 369 | if (!chunk) |
| 370 | break; |
| 371 | *lower_next = chunk; |
| 372 | lower_next = &chunk->next; |
| 373 | lcnt++; |
| 374 | } |
| 375 | |
| 376 | raw_spin_lock(&pid_list->lock); |
| 377 | if (upper) { |
| 378 | *upper_next = pid_list->upper_list; |
| 379 | pid_list->upper_list = upper; |
| 380 | pid_list->free_upper_chunks += ucnt; |
| 381 | } |
| 382 | if (lower) { |
| 383 | *lower_next = pid_list->lower_list; |
| 384 | pid_list->lower_list = lower; |
| 385 | pid_list->free_lower_chunks += lcnt; |
| 386 | } |
| 387 | raw_spin_unlock(&pid_list->lock); |
| 388 | |
| 389 | /* |
| 390 | * On success of allocating all the chunks, both counters |
| 391 | * will be less than zero. If they are not, then an allocation |
| 392 | * failed, and we should not try again. |
| 393 | */ |
| 394 | if (upper_count >= 0 || lower_count >= 0) |
| 395 | return; |
| 396 | /* |
| 397 | * When the locks were released, free chunks could have |
| 398 | * been used and allocation needs to be done again. Might as |
| 399 | * well allocate it now. |
| 400 | */ |
| 401 | goto again; |
Steven Rostedt (VMware) | 6954e41 | 2021-09-23 21:03:49 -0400 | [diff] [blame] | 402 | } |
| 403 | |
| 404 | /** |
| 405 | * trace_pid_list_alloc - create a new pid_list |
| 406 | * |
| 407 | * Allocates a new pid_list to store pids into. |
| 408 | * |
| 409 | * Returns the pid_list on success, NULL otherwise. |
| 410 | */ |
| 411 | struct trace_pid_list *trace_pid_list_alloc(void) |
| 412 | { |
| 413 | struct trace_pid_list *pid_list; |
Steven Rostedt (VMware) | 8d6e9098 | 2021-09-23 22:20:57 -0400 | [diff] [blame] | 414 | int i; |
Steven Rostedt (VMware) | 6954e41 | 2021-09-23 21:03:49 -0400 | [diff] [blame] | 415 | |
Steven Rostedt (VMware) | 8d6e9098 | 2021-09-23 22:20:57 -0400 | [diff] [blame] | 416 | /* According to linux/thread.h, pids can be no bigger that 30 bits */ |
| 417 | WARN_ON_ONCE(pid_max > (1 << 30)); |
| 418 | |
| 419 | pid_list = kzalloc(sizeof(*pid_list), GFP_KERNEL); |
Steven Rostedt (VMware) | 6954e41 | 2021-09-23 21:03:49 -0400 | [diff] [blame] | 420 | if (!pid_list) |
| 421 | return NULL; |
| 422 | |
Steven Rostedt (VMware) | 8d6e9098 | 2021-09-23 22:20:57 -0400 | [diff] [blame] | 423 | init_irq_work(&pid_list->refill_irqwork, pid_list_refill_irq); |
Steven Rostedt (VMware) | 6954e41 | 2021-09-23 21:03:49 -0400 | [diff] [blame] | 424 | |
Steven Rostedt (VMware) | 8d6e9098 | 2021-09-23 22:20:57 -0400 | [diff] [blame] | 425 | raw_spin_lock_init(&pid_list->lock); |
| 426 | |
| 427 | for (i = 0; i < CHUNK_ALLOC; i++) { |
| 428 | union upper_chunk *chunk; |
| 429 | |
| 430 | chunk = kzalloc(sizeof(*chunk), GFP_KERNEL); |
| 431 | if (!chunk) |
| 432 | break; |
| 433 | chunk->next = pid_list->upper_list; |
| 434 | pid_list->upper_list = chunk; |
| 435 | pid_list->free_upper_chunks++; |
Steven Rostedt (VMware) | 6954e41 | 2021-09-23 21:03:49 -0400 | [diff] [blame] | 436 | } |
Steven Rostedt (VMware) | 8d6e9098 | 2021-09-23 22:20:57 -0400 | [diff] [blame] | 437 | |
| 438 | for (i = 0; i < CHUNK_ALLOC; i++) { |
| 439 | union lower_chunk *chunk; |
| 440 | |
| 441 | chunk = kzalloc(sizeof(*chunk), GFP_KERNEL); |
| 442 | if (!chunk) |
| 443 | break; |
| 444 | chunk->next = pid_list->lower_list; |
| 445 | pid_list->lower_list = chunk; |
| 446 | pid_list->free_lower_chunks++; |
| 447 | } |
| 448 | |
Steven Rostedt (VMware) | 6954e41 | 2021-09-23 21:03:49 -0400 | [diff] [blame] | 449 | return pid_list; |
| 450 | } |
| 451 | |
| 452 | /** |
| 453 | * trace_pid_list_free - Frees an allocated pid_list. |
| 454 | * |
| 455 | * Frees the memory for a pid_list that was allocated. |
| 456 | */ |
| 457 | void trace_pid_list_free(struct trace_pid_list *pid_list) |
| 458 | { |
Steven Rostedt (VMware) | 8d6e9098 | 2021-09-23 22:20:57 -0400 | [diff] [blame] | 459 | union upper_chunk *upper; |
| 460 | union lower_chunk *lower; |
| 461 | int i, j; |
| 462 | |
Steven Rostedt (VMware) | 6954e41 | 2021-09-23 21:03:49 -0400 | [diff] [blame] | 463 | if (!pid_list) |
| 464 | return; |
| 465 | |
Steven Rostedt (VMware) | 8d6e9098 | 2021-09-23 22:20:57 -0400 | [diff] [blame] | 466 | irq_work_sync(&pid_list->refill_irqwork); |
| 467 | |
| 468 | while (pid_list->lower_list) { |
| 469 | union lower_chunk *chunk; |
| 470 | |
| 471 | chunk = pid_list->lower_list; |
| 472 | pid_list->lower_list = pid_list->lower_list->next; |
| 473 | kfree(chunk); |
| 474 | } |
| 475 | |
| 476 | while (pid_list->upper_list) { |
| 477 | union upper_chunk *chunk; |
| 478 | |
| 479 | chunk = pid_list->upper_list; |
| 480 | pid_list->upper_list = pid_list->upper_list->next; |
| 481 | kfree(chunk); |
| 482 | } |
| 483 | |
| 484 | for (i = 0; i < UPPER1_SIZE; i++) { |
| 485 | upper = pid_list->upper[i]; |
| 486 | if (upper) { |
| 487 | for (j = 0; j < UPPER2_SIZE; j++) { |
| 488 | lower = upper->data[j]; |
| 489 | kfree(lower); |
| 490 | } |
| 491 | kfree(upper); |
| 492 | } |
| 493 | } |
Steven Rostedt (VMware) | 6954e41 | 2021-09-23 21:03:49 -0400 | [diff] [blame] | 494 | kfree(pid_list); |
| 495 | } |