1 // SPDX-License-Identifier: GPL-2.0 2 /* Copyright (c) 2011-2015 PLUMgrid, http://plumgrid.com 3 * Copyright (c) 2016 Facebook 4 */ 5 #include <linux/kernel.h> 6 #include <linux/types.h> 7 #include <linux/slab.h> 8 #include <linux/bpf.h> 9 #include <linux/bpf_perf_event.h> 10 #include <linux/filter.h> 11 #include <linux/uaccess.h> 12 #include <linux/ctype.h> 13 #include <linux/kprobes.h> 14 #include <linux/syscalls.h> 15 #include <linux/error-injection.h> 16 17 #include "trace_probe.h" 18 #include "trace.h" 19 20 #ifdef CONFIG_MODULES 21 struct bpf_trace_module { 22 struct module *module; 23 struct list_head list; 24 }; 25 26 static LIST_HEAD(bpf_trace_modules); 27 static DEFINE_MUTEX(bpf_module_mutex); 28 29 static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name) 30 { 31 struct bpf_raw_event_map *btp, *ret = NULL; 32 struct bpf_trace_module *btm; 33 unsigned int i; 34 35 mutex_lock(&bpf_module_mutex); 36 list_for_each_entry(btm, &bpf_trace_modules, list) { 37 for (i = 0; i < btm->module->num_bpf_raw_events; ++i) { 38 btp = &btm->module->bpf_raw_events[i]; 39 if (!strcmp(btp->tp->name, name)) { 40 if (try_module_get(btm->module)) 41 ret = btp; 42 goto out; 43 } 44 } 45 } 46 out: 47 mutex_unlock(&bpf_module_mutex); 48 return ret; 49 } 50 #else 51 static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name) 52 { 53 return NULL; 54 } 55 #endif /* CONFIG_MODULES */ 56 57 u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); 58 u64 bpf_get_stack(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); 59 60 /** 61 * trace_call_bpf - invoke BPF program 62 * @call: tracepoint event 63 * @ctx: opaque context pointer 64 * 65 * kprobe handlers execute BPF programs via this helper. 66 * Can be used from static tracepoints in the future. 67 * 68 * Return: BPF programs always return an integer which is interpreted by 69 * kprobe handler as: 70 * 0 - return from kprobe (event is filtered out) 71 * 1 - store kprobe event into ring buffer 72 * Other values are reserved and currently alias to 1 73 */ 74 unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx) 75 { 76 unsigned int ret; 77 78 if (in_nmi()) /* not supported yet */ 79 return 1; 80 81 preempt_disable(); 82 83 if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) { 84 /* 85 * since some bpf program is already running on this cpu, 86 * don't call into another bpf program (same or different) 87 * and don't send kprobe event into ring-buffer, 88 * so return zero here 89 */ 90 ret = 0; 91 goto out; 92 } 93 94 /* 95 * Instead of moving rcu_read_lock/rcu_dereference/rcu_read_unlock 96 * to all call sites, we did a bpf_prog_array_valid() there to check 97 * whether call->prog_array is empty or not, which is 98 * a heurisitc to speed up execution. 99 * 100 * If bpf_prog_array_valid() fetched prog_array was 101 * non-NULL, we go into trace_call_bpf() and do the actual 102 * proper rcu_dereference() under RCU lock. 103 * If it turns out that prog_array is NULL then, we bail out. 104 * For the opposite, if the bpf_prog_array_valid() fetched pointer 105 * was NULL, you'll skip the prog_array with the risk of missing 106 * out of events when it was updated in between this and the 107 * rcu_dereference() which is accepted risk. 108 */ 109 ret = BPF_PROG_RUN_ARRAY_CHECK(call->prog_array, ctx, BPF_PROG_RUN); 110 111 out: 112 __this_cpu_dec(bpf_prog_active); 113 preempt_enable(); 114 115 return ret; 116 } 117 EXPORT_SYMBOL_GPL(trace_call_bpf); 118 119 #ifdef CONFIG_BPF_KPROBE_OVERRIDE 120 BPF_CALL_2(bpf_override_return, struct pt_regs *, regs, unsigned long, rc) 121 { 122 regs_set_return_value(regs, rc); 123 override_function_with_return(regs); 124 return 0; 125 } 126 127 static const struct bpf_func_proto bpf_override_return_proto = { 128 .func = bpf_override_return, 129 .gpl_only = true, 130 .ret_type = RET_INTEGER, 131 .arg1_type = ARG_PTR_TO_CTX, 132 .arg2_type = ARG_ANYTHING, 133 }; 134 #endif 135 136 BPF_CALL_3(bpf_probe_read, void *, dst, u32, size, const void *, unsafe_ptr) 137 { 138 int ret; 139 140 ret = probe_kernel_read(dst, unsafe_ptr, size); 141 if (unlikely(ret < 0)) 142 memset(dst, 0, size); 143 144 return ret; 145 } 146 147 static const struct bpf_func_proto bpf_probe_read_proto = { 148 .func = bpf_probe_read, 149 .gpl_only = true, 150 .ret_type = RET_INTEGER, 151 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 152 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 153 .arg3_type = ARG_ANYTHING, 154 }; 155 156 BPF_CALL_3(bpf_probe_write_user, void *, unsafe_ptr, const void *, src, 157 u32, size) 158 { 159 /* 160 * Ensure we're in user context which is safe for the helper to 161 * run. This helper has no business in a kthread. 162 * 163 * access_ok() should prevent writing to non-user memory, but in 164 * some situations (nommu, temporary switch, etc) access_ok() does 165 * not provide enough validation, hence the check on KERNEL_DS. 166 */ 167 168 if (unlikely(in_interrupt() || 169 current->flags & (PF_KTHREAD | PF_EXITING))) 170 return -EPERM; 171 if (unlikely(uaccess_kernel())) 172 return -EPERM; 173 if (!access_ok(unsafe_ptr, size)) 174 return -EPERM; 175 176 return probe_kernel_write(unsafe_ptr, src, size); 177 } 178 179 static const struct bpf_func_proto bpf_probe_write_user_proto = { 180 .func = bpf_probe_write_user, 181 .gpl_only = true, 182 .ret_type = RET_INTEGER, 183 .arg1_type = ARG_ANYTHING, 184 .arg2_type = ARG_PTR_TO_MEM, 185 .arg3_type = ARG_CONST_SIZE, 186 }; 187 188 static const struct bpf_func_proto *bpf_get_probe_write_proto(void) 189 { 190 pr_warn_ratelimited("%s[%d] is installing a program with bpf_probe_write_user helper that may corrupt user memory!", 191 current->comm, task_pid_nr(current)); 192 193 return &bpf_probe_write_user_proto; 194 } 195 196 /* 197 * Only limited trace_printk() conversion specifiers allowed: 198 * %d %i %u %x %ld %li %lu %lx %lld %lli %llu %llx %p %s 199 */ 200 BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1, 201 u64, arg2, u64, arg3) 202 { 203 bool str_seen = false; 204 int mod[3] = {}; 205 int fmt_cnt = 0; 206 u64 unsafe_addr; 207 char buf[64]; 208 int i; 209 210 /* 211 * bpf_check()->check_func_arg()->check_stack_boundary() 212 * guarantees that fmt points to bpf program stack, 213 * fmt_size bytes of it were initialized and fmt_size > 0 214 */ 215 if (fmt[--fmt_size] != 0) 216 return -EINVAL; 217 218 /* check format string for allowed specifiers */ 219 for (i = 0; i < fmt_size; i++) { 220 if ((!isprint(fmt[i]) && !isspace(fmt[i])) || !isascii(fmt[i])) 221 return -EINVAL; 222 223 if (fmt[i] != '%') 224 continue; 225 226 if (fmt_cnt >= 3) 227 return -EINVAL; 228 229 /* fmt[i] != 0 && fmt[last] == 0, so we can access fmt[i + 1] */ 230 i++; 231 if (fmt[i] == 'l') { 232 mod[fmt_cnt]++; 233 i++; 234 } else if (fmt[i] == 'p' || fmt[i] == 's') { 235 mod[fmt_cnt]++; 236 /* disallow any further format extensions */ 237 if (fmt[i + 1] != 0 && 238 !isspace(fmt[i + 1]) && 239 !ispunct(fmt[i + 1])) 240 return -EINVAL; 241 fmt_cnt++; 242 if (fmt[i] == 's') { 243 if (str_seen) 244 /* allow only one '%s' per fmt string */ 245 return -EINVAL; 246 str_seen = true; 247 248 switch (fmt_cnt) { 249 case 1: 250 unsafe_addr = arg1; 251 arg1 = (long) buf; 252 break; 253 case 2: 254 unsafe_addr = arg2; 255 arg2 = (long) buf; 256 break; 257 case 3: 258 unsafe_addr = arg3; 259 arg3 = (long) buf; 260 break; 261 } 262 buf[0] = 0; 263 strncpy_from_unsafe(buf, 264 (void *) (long) unsafe_addr, 265 sizeof(buf)); 266 } 267 continue; 268 } 269 270 if (fmt[i] == 'l') { 271 mod[fmt_cnt]++; 272 i++; 273 } 274 275 if (fmt[i] != 'i' && fmt[i] != 'd' && 276 fmt[i] != 'u' && fmt[i] != 'x') 277 return -EINVAL; 278 fmt_cnt++; 279 } 280 281 /* Horrid workaround for getting va_list handling working with different 282 * argument type combinations generically for 32 and 64 bit archs. 283 */ 284 #define __BPF_TP_EMIT() __BPF_ARG3_TP() 285 #define __BPF_TP(...) \ 286 __trace_printk(0 /* Fake ip */, \ 287 fmt, ##__VA_ARGS__) 288 289 #define __BPF_ARG1_TP(...) \ 290 ((mod[0] == 2 || (mod[0] == 1 && __BITS_PER_LONG == 64)) \ 291 ? __BPF_TP(arg1, ##__VA_ARGS__) \ 292 : ((mod[0] == 1 || (mod[0] == 0 && __BITS_PER_LONG == 32)) \ 293 ? __BPF_TP((long)arg1, ##__VA_ARGS__) \ 294 : __BPF_TP((u32)arg1, ##__VA_ARGS__))) 295 296 #define __BPF_ARG2_TP(...) \ 297 ((mod[1] == 2 || (mod[1] == 1 && __BITS_PER_LONG == 64)) \ 298 ? __BPF_ARG1_TP(arg2, ##__VA_ARGS__) \ 299 : ((mod[1] == 1 || (mod[1] == 0 && __BITS_PER_LONG == 32)) \ 300 ? __BPF_ARG1_TP((long)arg2, ##__VA_ARGS__) \ 301 : __BPF_ARG1_TP((u32)arg2, ##__VA_ARGS__))) 302 303 #define __BPF_ARG3_TP(...) \ 304 ((mod[2] == 2 || (mod[2] == 1 && __BITS_PER_LONG == 64)) \ 305 ? __BPF_ARG2_TP(arg3, ##__VA_ARGS__) \ 306 : ((mod[2] == 1 || (mod[2] == 0 && __BITS_PER_LONG == 32)) \ 307 ? __BPF_ARG2_TP((long)arg3, ##__VA_ARGS__) \ 308 : __BPF_ARG2_TP((u32)arg3, ##__VA_ARGS__))) 309 310 return __BPF_TP_EMIT(); 311 } 312 313 static const struct bpf_func_proto bpf_trace_printk_proto = { 314 .func = bpf_trace_printk, 315 .gpl_only = true, 316 .ret_type = RET_INTEGER, 317 .arg1_type = ARG_PTR_TO_MEM, 318 .arg2_type = ARG_CONST_SIZE, 319 }; 320 321 const struct bpf_func_proto *bpf_get_trace_printk_proto(void) 322 { 323 /* 324 * this program might be calling bpf_trace_printk, 325 * so allocate per-cpu printk buffers 326 */ 327 trace_printk_init_buffers(); 328 329 return &bpf_trace_printk_proto; 330 } 331 332 static __always_inline int 333 get_map_perf_counter(struct bpf_map *map, u64 flags, 334 u64 *value, u64 *enabled, u64 *running) 335 { 336 struct bpf_array *array = container_of(map, struct bpf_array, map); 337 unsigned int cpu = smp_processor_id(); 338 u64 index = flags & BPF_F_INDEX_MASK; 339 struct bpf_event_entry *ee; 340 341 if (unlikely(flags & ~(BPF_F_INDEX_MASK))) 342 return -EINVAL; 343 if (index == BPF_F_CURRENT_CPU) 344 index = cpu; 345 if (unlikely(index >= array->map.max_entries)) 346 return -E2BIG; 347 348 ee = READ_ONCE(array->ptrs[index]); 349 if (!ee) 350 return -ENOENT; 351 352 return perf_event_read_local(ee->event, value, enabled, running); 353 } 354 355 BPF_CALL_2(bpf_perf_event_read, struct bpf_map *, map, u64, flags) 356 { 357 u64 value = 0; 358 int err; 359 360 err = get_map_perf_counter(map, flags, &value, NULL, NULL); 361 /* 362 * this api is ugly since we miss [-22..-2] range of valid 363 * counter values, but that's uapi 364 */ 365 if (err) 366 return err; 367 return value; 368 } 369 370 static const struct bpf_func_proto bpf_perf_event_read_proto = { 371 .func = bpf_perf_event_read, 372 .gpl_only = true, 373 .ret_type = RET_INTEGER, 374 .arg1_type = ARG_CONST_MAP_PTR, 375 .arg2_type = ARG_ANYTHING, 376 }; 377 378 BPF_CALL_4(bpf_perf_event_read_value, struct bpf_map *, map, u64, flags, 379 struct bpf_perf_event_value *, buf, u32, size) 380 { 381 int err = -EINVAL; 382 383 if (unlikely(size != sizeof(struct bpf_perf_event_value))) 384 goto clear; 385 err = get_map_perf_counter(map, flags, &buf->counter, &buf->enabled, 386 &buf->running); 387 if (unlikely(err)) 388 goto clear; 389 return 0; 390 clear: 391 memset(buf, 0, size); 392 return err; 393 } 394 395 static const struct bpf_func_proto bpf_perf_event_read_value_proto = { 396 .func = bpf_perf_event_read_value, 397 .gpl_only = true, 398 .ret_type = RET_INTEGER, 399 .arg1_type = ARG_CONST_MAP_PTR, 400 .arg2_type = ARG_ANYTHING, 401 .arg3_type = ARG_PTR_TO_UNINIT_MEM, 402 .arg4_type = ARG_CONST_SIZE, 403 }; 404 405 static DEFINE_PER_CPU(struct perf_sample_data, bpf_trace_sd); 406 407 static __always_inline u64 408 __bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map, 409 u64 flags, struct perf_sample_data *sd) 410 { 411 struct bpf_array *array = container_of(map, struct bpf_array, map); 412 unsigned int cpu = smp_processor_id(); 413 u64 index = flags & BPF_F_INDEX_MASK; 414 struct bpf_event_entry *ee; 415 struct perf_event *event; 416 417 if (index == BPF_F_CURRENT_CPU) 418 index = cpu; 419 if (unlikely(index >= array->map.max_entries)) 420 return -E2BIG; 421 422 ee = READ_ONCE(array->ptrs[index]); 423 if (!ee) 424 return -ENOENT; 425 426 event = ee->event; 427 if (unlikely(event->attr.type != PERF_TYPE_SOFTWARE || 428 event->attr.config != PERF_COUNT_SW_BPF_OUTPUT)) 429 return -EINVAL; 430 431 if (unlikely(event->oncpu != cpu)) 432 return -EOPNOTSUPP; 433 434 return perf_event_output(event, sd, regs); 435 } 436 437 BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map, 438 u64, flags, void *, data, u64, size) 439 { 440 struct perf_sample_data *sd = this_cpu_ptr(&bpf_trace_sd); 441 struct perf_raw_record raw = { 442 .frag = { 443 .size = size, 444 .data = data, 445 }, 446 }; 447 448 if (unlikely(flags & ~(BPF_F_INDEX_MASK))) 449 return -EINVAL; 450 451 perf_sample_data_init(sd, 0, 0); 452 sd->raw = &raw; 453 454 return __bpf_perf_event_output(regs, map, flags, sd); 455 } 456 457 static const struct bpf_func_proto bpf_perf_event_output_proto = { 458 .func = bpf_perf_event_output, 459 .gpl_only = true, 460 .ret_type = RET_INTEGER, 461 .arg1_type = ARG_PTR_TO_CTX, 462 .arg2_type = ARG_CONST_MAP_PTR, 463 .arg3_type = ARG_ANYTHING, 464 .arg4_type = ARG_PTR_TO_MEM, 465 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 466 }; 467 468 static DEFINE_PER_CPU(struct pt_regs, bpf_pt_regs); 469 static DEFINE_PER_CPU(struct perf_sample_data, bpf_misc_sd); 470 471 u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size, 472 void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy) 473 { 474 struct perf_sample_data *sd = this_cpu_ptr(&bpf_misc_sd); 475 struct pt_regs *regs = this_cpu_ptr(&bpf_pt_regs); 476 struct perf_raw_frag frag = { 477 .copy = ctx_copy, 478 .size = ctx_size, 479 .data = ctx, 480 }; 481 struct perf_raw_record raw = { 482 .frag = { 483 { 484 .next = ctx_size ? &frag : NULL, 485 }, 486 .size = meta_size, 487 .data = meta, 488 }, 489 }; 490 491 perf_fetch_caller_regs(regs); 492 perf_sample_data_init(sd, 0, 0); 493 sd->raw = &raw; 494 495 return __bpf_perf_event_output(regs, map, flags, sd); 496 } 497 498 BPF_CALL_0(bpf_get_current_task) 499 { 500 return (long) current; 501 } 502 503 static const struct bpf_func_proto bpf_get_current_task_proto = { 504 .func = bpf_get_current_task, 505 .gpl_only = true, 506 .ret_type = RET_INTEGER, 507 }; 508 509 BPF_CALL_2(bpf_current_task_under_cgroup, struct bpf_map *, map, u32, idx) 510 { 511 struct bpf_array *array = container_of(map, struct bpf_array, map); 512 struct cgroup *cgrp; 513 514 if (unlikely(idx >= array->map.max_entries)) 515 return -E2BIG; 516 517 cgrp = READ_ONCE(array->ptrs[idx]); 518 if (unlikely(!cgrp)) 519 return -EAGAIN; 520 521 return task_under_cgroup_hierarchy(current, cgrp); 522 } 523 524 static const struct bpf_func_proto bpf_current_task_under_cgroup_proto = { 525 .func = bpf_current_task_under_cgroup, 526 .gpl_only = false, 527 .ret_type = RET_INTEGER, 528 .arg1_type = ARG_CONST_MAP_PTR, 529 .arg2_type = ARG_ANYTHING, 530 }; 531 532 BPF_CALL_3(bpf_probe_read_str, void *, dst, u32, size, 533 const void *, unsafe_ptr) 534 { 535 int ret; 536 537 /* 538 * The strncpy_from_unsafe() call will likely not fill the entire 539 * buffer, but that's okay in this circumstance as we're probing 540 * arbitrary memory anyway similar to bpf_probe_read() and might 541 * as well probe the stack. Thus, memory is explicitly cleared 542 * only in error case, so that improper users ignoring return 543 * code altogether don't copy garbage; otherwise length of string 544 * is returned that can be used for bpf_perf_event_output() et al. 545 */ 546 ret = strncpy_from_unsafe(dst, unsafe_ptr, size); 547 if (unlikely(ret < 0)) 548 memset(dst, 0, size); 549 550 return ret; 551 } 552 553 static const struct bpf_func_proto bpf_probe_read_str_proto = { 554 .func = bpf_probe_read_str, 555 .gpl_only = true, 556 .ret_type = RET_INTEGER, 557 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 558 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 559 .arg3_type = ARG_ANYTHING, 560 }; 561 562 static const struct bpf_func_proto * 563 tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 564 { 565 switch (func_id) { 566 case BPF_FUNC_map_lookup_elem: 567 return &bpf_map_lookup_elem_proto; 568 case BPF_FUNC_map_update_elem: 569 return &bpf_map_update_elem_proto; 570 case BPF_FUNC_map_delete_elem: 571 return &bpf_map_delete_elem_proto; 572 case BPF_FUNC_probe_read: 573 return &bpf_probe_read_proto; 574 case BPF_FUNC_ktime_get_ns: 575 return &bpf_ktime_get_ns_proto; 576 case BPF_FUNC_tail_call: 577 return &bpf_tail_call_proto; 578 case BPF_FUNC_get_current_pid_tgid: 579 return &bpf_get_current_pid_tgid_proto; 580 case BPF_FUNC_get_current_task: 581 return &bpf_get_current_task_proto; 582 case BPF_FUNC_get_current_uid_gid: 583 return &bpf_get_current_uid_gid_proto; 584 case BPF_FUNC_get_current_comm: 585 return &bpf_get_current_comm_proto; 586 case BPF_FUNC_trace_printk: 587 return bpf_get_trace_printk_proto(); 588 case BPF_FUNC_get_smp_processor_id: 589 return &bpf_get_smp_processor_id_proto; 590 case BPF_FUNC_get_numa_node_id: 591 return &bpf_get_numa_node_id_proto; 592 case BPF_FUNC_perf_event_read: 593 return &bpf_perf_event_read_proto; 594 case BPF_FUNC_probe_write_user: 595 return bpf_get_probe_write_proto(); 596 case BPF_FUNC_current_task_under_cgroup: 597 return &bpf_current_task_under_cgroup_proto; 598 case BPF_FUNC_get_prandom_u32: 599 return &bpf_get_prandom_u32_proto; 600 case BPF_FUNC_probe_read_str: 601 return &bpf_probe_read_str_proto; 602 #ifdef CONFIG_CGROUPS 603 case BPF_FUNC_get_current_cgroup_id: 604 return &bpf_get_current_cgroup_id_proto; 605 #endif 606 default: 607 return NULL; 608 } 609 } 610 611 static const struct bpf_func_proto * 612 kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 613 { 614 switch (func_id) { 615 case BPF_FUNC_perf_event_output: 616 return &bpf_perf_event_output_proto; 617 case BPF_FUNC_get_stackid: 618 return &bpf_get_stackid_proto; 619 case BPF_FUNC_get_stack: 620 return &bpf_get_stack_proto; 621 case BPF_FUNC_perf_event_read_value: 622 return &bpf_perf_event_read_value_proto; 623 #ifdef CONFIG_BPF_KPROBE_OVERRIDE 624 case BPF_FUNC_override_return: 625 return &bpf_override_return_proto; 626 #endif 627 default: 628 return tracing_func_proto(func_id, prog); 629 } 630 } 631 632 /* bpf+kprobe programs can access fields of 'struct pt_regs' */ 633 static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type, 634 const struct bpf_prog *prog, 635 struct bpf_insn_access_aux *info) 636 { 637 if (off < 0 || off >= sizeof(struct pt_regs)) 638 return false; 639 if (type != BPF_READ) 640 return false; 641 if (off % size != 0) 642 return false; 643 /* 644 * Assertion for 32 bit to make sure last 8 byte access 645 * (BPF_DW) to the last 4 byte member is disallowed. 646 */ 647 if (off + size > sizeof(struct pt_regs)) 648 return false; 649 650 return true; 651 } 652 653 const struct bpf_verifier_ops kprobe_verifier_ops = { 654 .get_func_proto = kprobe_prog_func_proto, 655 .is_valid_access = kprobe_prog_is_valid_access, 656 }; 657 658 const struct bpf_prog_ops kprobe_prog_ops = { 659 }; 660 661 BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map, 662 u64, flags, void *, data, u64, size) 663 { 664 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 665 666 /* 667 * r1 points to perf tracepoint buffer where first 8 bytes are hidden 668 * from bpf program and contain a pointer to 'struct pt_regs'. Fetch it 669 * from there and call the same bpf_perf_event_output() helper inline. 670 */ 671 return ____bpf_perf_event_output(regs, map, flags, data, size); 672 } 673 674 static const struct bpf_func_proto bpf_perf_event_output_proto_tp = { 675 .func = bpf_perf_event_output_tp, 676 .gpl_only = true, 677 .ret_type = RET_INTEGER, 678 .arg1_type = ARG_PTR_TO_CTX, 679 .arg2_type = ARG_CONST_MAP_PTR, 680 .arg3_type = ARG_ANYTHING, 681 .arg4_type = ARG_PTR_TO_MEM, 682 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 683 }; 684 685 BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map, 686 u64, flags) 687 { 688 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 689 690 /* 691 * Same comment as in bpf_perf_event_output_tp(), only that this time 692 * the other helper's function body cannot be inlined due to being 693 * external, thus we need to call raw helper function. 694 */ 695 return bpf_get_stackid((unsigned long) regs, (unsigned long) map, 696 flags, 0, 0); 697 } 698 699 static const struct bpf_func_proto bpf_get_stackid_proto_tp = { 700 .func = bpf_get_stackid_tp, 701 .gpl_only = true, 702 .ret_type = RET_INTEGER, 703 .arg1_type = ARG_PTR_TO_CTX, 704 .arg2_type = ARG_CONST_MAP_PTR, 705 .arg3_type = ARG_ANYTHING, 706 }; 707 708 BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size, 709 u64, flags) 710 { 711 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 712 713 return bpf_get_stack((unsigned long) regs, (unsigned long) buf, 714 (unsigned long) size, flags, 0); 715 } 716 717 static const struct bpf_func_proto bpf_get_stack_proto_tp = { 718 .func = bpf_get_stack_tp, 719 .gpl_only = true, 720 .ret_type = RET_INTEGER, 721 .arg1_type = ARG_PTR_TO_CTX, 722 .arg2_type = ARG_PTR_TO_UNINIT_MEM, 723 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 724 .arg4_type = ARG_ANYTHING, 725 }; 726 727 static const struct bpf_func_proto * 728 tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 729 { 730 switch (func_id) { 731 case BPF_FUNC_perf_event_output: 732 return &bpf_perf_event_output_proto_tp; 733 case BPF_FUNC_get_stackid: 734 return &bpf_get_stackid_proto_tp; 735 case BPF_FUNC_get_stack: 736 return &bpf_get_stack_proto_tp; 737 default: 738 return tracing_func_proto(func_id, prog); 739 } 740 } 741 742 static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type, 743 const struct bpf_prog *prog, 744 struct bpf_insn_access_aux *info) 745 { 746 if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE) 747 return false; 748 if (type != BPF_READ) 749 return false; 750 if (off % size != 0) 751 return false; 752 753 BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(__u64)); 754 return true; 755 } 756 757 const struct bpf_verifier_ops tracepoint_verifier_ops = { 758 .get_func_proto = tp_prog_func_proto, 759 .is_valid_access = tp_prog_is_valid_access, 760 }; 761 762 const struct bpf_prog_ops tracepoint_prog_ops = { 763 }; 764 765 BPF_CALL_3(bpf_perf_prog_read_value, struct bpf_perf_event_data_kern *, ctx, 766 struct bpf_perf_event_value *, buf, u32, size) 767 { 768 int err = -EINVAL; 769 770 if (unlikely(size != sizeof(struct bpf_perf_event_value))) 771 goto clear; 772 err = perf_event_read_local(ctx->event, &buf->counter, &buf->enabled, 773 &buf->running); 774 if (unlikely(err)) 775 goto clear; 776 return 0; 777 clear: 778 memset(buf, 0, size); 779 return err; 780 } 781 782 static const struct bpf_func_proto bpf_perf_prog_read_value_proto = { 783 .func = bpf_perf_prog_read_value, 784 .gpl_only = true, 785 .ret_type = RET_INTEGER, 786 .arg1_type = ARG_PTR_TO_CTX, 787 .arg2_type = ARG_PTR_TO_UNINIT_MEM, 788 .arg3_type = ARG_CONST_SIZE, 789 }; 790 791 static const struct bpf_func_proto * 792 pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 793 { 794 switch (func_id) { 795 case BPF_FUNC_perf_event_output: 796 return &bpf_perf_event_output_proto_tp; 797 case BPF_FUNC_get_stackid: 798 return &bpf_get_stackid_proto_tp; 799 case BPF_FUNC_get_stack: 800 return &bpf_get_stack_proto_tp; 801 case BPF_FUNC_perf_prog_read_value: 802 return &bpf_perf_prog_read_value_proto; 803 default: 804 return tracing_func_proto(func_id, prog); 805 } 806 } 807 808 /* 809 * bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp 810 * to avoid potential recursive reuse issue when/if tracepoints are added 811 * inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack 812 */ 813 static DEFINE_PER_CPU(struct pt_regs, bpf_raw_tp_regs); 814 BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args, 815 struct bpf_map *, map, u64, flags, void *, data, u64, size) 816 { 817 struct pt_regs *regs = this_cpu_ptr(&bpf_raw_tp_regs); 818 819 perf_fetch_caller_regs(regs); 820 return ____bpf_perf_event_output(regs, map, flags, data, size); 821 } 822 823 static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = { 824 .func = bpf_perf_event_output_raw_tp, 825 .gpl_only = true, 826 .ret_type = RET_INTEGER, 827 .arg1_type = ARG_PTR_TO_CTX, 828 .arg2_type = ARG_CONST_MAP_PTR, 829 .arg3_type = ARG_ANYTHING, 830 .arg4_type = ARG_PTR_TO_MEM, 831 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 832 }; 833 834 BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args, 835 struct bpf_map *, map, u64, flags) 836 { 837 struct pt_regs *regs = this_cpu_ptr(&bpf_raw_tp_regs); 838 839 perf_fetch_caller_regs(regs); 840 /* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */ 841 return bpf_get_stackid((unsigned long) regs, (unsigned long) map, 842 flags, 0, 0); 843 } 844 845 static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = { 846 .func = bpf_get_stackid_raw_tp, 847 .gpl_only = true, 848 .ret_type = RET_INTEGER, 849 .arg1_type = ARG_PTR_TO_CTX, 850 .arg2_type = ARG_CONST_MAP_PTR, 851 .arg3_type = ARG_ANYTHING, 852 }; 853 854 BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args, 855 void *, buf, u32, size, u64, flags) 856 { 857 struct pt_regs *regs = this_cpu_ptr(&bpf_raw_tp_regs); 858 859 perf_fetch_caller_regs(regs); 860 return bpf_get_stack((unsigned long) regs, (unsigned long) buf, 861 (unsigned long) size, flags, 0); 862 } 863 864 static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = { 865 .func = bpf_get_stack_raw_tp, 866 .gpl_only = true, 867 .ret_type = RET_INTEGER, 868 .arg1_type = ARG_PTR_TO_CTX, 869 .arg2_type = ARG_PTR_TO_MEM, 870 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 871 .arg4_type = ARG_ANYTHING, 872 }; 873 874 static const struct bpf_func_proto * 875 raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 876 { 877 switch (func_id) { 878 case BPF_FUNC_perf_event_output: 879 return &bpf_perf_event_output_proto_raw_tp; 880 case BPF_FUNC_get_stackid: 881 return &bpf_get_stackid_proto_raw_tp; 882 case BPF_FUNC_get_stack: 883 return &bpf_get_stack_proto_raw_tp; 884 default: 885 return tracing_func_proto(func_id, prog); 886 } 887 } 888 889 static bool raw_tp_prog_is_valid_access(int off, int size, 890 enum bpf_access_type type, 891 const struct bpf_prog *prog, 892 struct bpf_insn_access_aux *info) 893 { 894 /* largest tracepoint in the kernel has 12 args */ 895 if (off < 0 || off >= sizeof(__u64) * 12) 896 return false; 897 if (type != BPF_READ) 898 return false; 899 if (off % size != 0) 900 return false; 901 return true; 902 } 903 904 const struct bpf_verifier_ops raw_tracepoint_verifier_ops = { 905 .get_func_proto = raw_tp_prog_func_proto, 906 .is_valid_access = raw_tp_prog_is_valid_access, 907 }; 908 909 const struct bpf_prog_ops raw_tracepoint_prog_ops = { 910 }; 911 912 static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type, 913 const struct bpf_prog *prog, 914 struct bpf_insn_access_aux *info) 915 { 916 const int size_u64 = sizeof(u64); 917 918 if (off < 0 || off >= sizeof(struct bpf_perf_event_data)) 919 return false; 920 if (type != BPF_READ) 921 return false; 922 if (off % size != 0) { 923 if (sizeof(unsigned long) != 4) 924 return false; 925 if (size != 8) 926 return false; 927 if (off % size != 4) 928 return false; 929 } 930 931 switch (off) { 932 case bpf_ctx_range(struct bpf_perf_event_data, sample_period): 933 bpf_ctx_record_field_size(info, size_u64); 934 if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) 935 return false; 936 break; 937 case bpf_ctx_range(struct bpf_perf_event_data, addr): 938 bpf_ctx_record_field_size(info, size_u64); 939 if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) 940 return false; 941 break; 942 default: 943 if (size != sizeof(long)) 944 return false; 945 } 946 947 return true; 948 } 949 950 static u32 pe_prog_convert_ctx_access(enum bpf_access_type type, 951 const struct bpf_insn *si, 952 struct bpf_insn *insn_buf, 953 struct bpf_prog *prog, u32 *target_size) 954 { 955 struct bpf_insn *insn = insn_buf; 956 957 switch (si->off) { 958 case offsetof(struct bpf_perf_event_data, sample_period): 959 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 960 data), si->dst_reg, si->src_reg, 961 offsetof(struct bpf_perf_event_data_kern, data)); 962 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, 963 bpf_target_off(struct perf_sample_data, period, 8, 964 target_size)); 965 break; 966 case offsetof(struct bpf_perf_event_data, addr): 967 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 968 data), si->dst_reg, si->src_reg, 969 offsetof(struct bpf_perf_event_data_kern, data)); 970 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, 971 bpf_target_off(struct perf_sample_data, addr, 8, 972 target_size)); 973 break; 974 default: 975 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 976 regs), si->dst_reg, si->src_reg, 977 offsetof(struct bpf_perf_event_data_kern, regs)); 978 *insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg, 979 si->off); 980 break; 981 } 982 983 return insn - insn_buf; 984 } 985 986 const struct bpf_verifier_ops perf_event_verifier_ops = { 987 .get_func_proto = pe_prog_func_proto, 988 .is_valid_access = pe_prog_is_valid_access, 989 .convert_ctx_access = pe_prog_convert_ctx_access, 990 }; 991 992 const struct bpf_prog_ops perf_event_prog_ops = { 993 }; 994 995 static DEFINE_MUTEX(bpf_event_mutex); 996 997 #define BPF_TRACE_MAX_PROGS 64 998 999 int perf_event_attach_bpf_prog(struct perf_event *event, 1000 struct bpf_prog *prog) 1001 { 1002 struct bpf_prog_array __rcu *old_array; 1003 struct bpf_prog_array *new_array; 1004 int ret = -EEXIST; 1005 1006 /* 1007 * Kprobe override only works if they are on the function entry, 1008 * and only if they are on the opt-in list. 1009 */ 1010 if (prog->kprobe_override && 1011 (!trace_kprobe_on_func_entry(event->tp_event) || 1012 !trace_kprobe_error_injectable(event->tp_event))) 1013 return -EINVAL; 1014 1015 mutex_lock(&bpf_event_mutex); 1016 1017 if (event->prog) 1018 goto unlock; 1019 1020 old_array = event->tp_event->prog_array; 1021 if (old_array && 1022 bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) { 1023 ret = -E2BIG; 1024 goto unlock; 1025 } 1026 1027 ret = bpf_prog_array_copy(old_array, NULL, prog, &new_array); 1028 if (ret < 0) 1029 goto unlock; 1030 1031 /* set the new array to event->tp_event and set event->prog */ 1032 event->prog = prog; 1033 rcu_assign_pointer(event->tp_event->prog_array, new_array); 1034 bpf_prog_array_free(old_array); 1035 1036 unlock: 1037 mutex_unlock(&bpf_event_mutex); 1038 return ret; 1039 } 1040 1041 void perf_event_detach_bpf_prog(struct perf_event *event) 1042 { 1043 struct bpf_prog_array __rcu *old_array; 1044 struct bpf_prog_array *new_array; 1045 int ret; 1046 1047 mutex_lock(&bpf_event_mutex); 1048 1049 if (!event->prog) 1050 goto unlock; 1051 1052 old_array = event->tp_event->prog_array; 1053 ret = bpf_prog_array_copy(old_array, event->prog, NULL, &new_array); 1054 if (ret == -ENOENT) 1055 goto unlock; 1056 if (ret < 0) { 1057 bpf_prog_array_delete_safe(old_array, event->prog); 1058 } else { 1059 rcu_assign_pointer(event->tp_event->prog_array, new_array); 1060 bpf_prog_array_free(old_array); 1061 } 1062 1063 bpf_prog_put(event->prog); 1064 event->prog = NULL; 1065 1066 unlock: 1067 mutex_unlock(&bpf_event_mutex); 1068 } 1069 1070 int perf_event_query_prog_array(struct perf_event *event, void __user *info) 1071 { 1072 struct perf_event_query_bpf __user *uquery = info; 1073 struct perf_event_query_bpf query = {}; 1074 u32 *ids, prog_cnt, ids_len; 1075 int ret; 1076 1077 if (!capable(CAP_SYS_ADMIN)) 1078 return -EPERM; 1079 if (event->attr.type != PERF_TYPE_TRACEPOINT) 1080 return -EINVAL; 1081 if (copy_from_user(&query, uquery, sizeof(query))) 1082 return -EFAULT; 1083 1084 ids_len = query.ids_len; 1085 if (ids_len > BPF_TRACE_MAX_PROGS) 1086 return -E2BIG; 1087 ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN); 1088 if (!ids) 1089 return -ENOMEM; 1090 /* 1091 * The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which 1092 * is required when user only wants to check for uquery->prog_cnt. 1093 * There is no need to check for it since the case is handled 1094 * gracefully in bpf_prog_array_copy_info. 1095 */ 1096 1097 mutex_lock(&bpf_event_mutex); 1098 ret = bpf_prog_array_copy_info(event->tp_event->prog_array, 1099 ids, 1100 ids_len, 1101 &prog_cnt); 1102 mutex_unlock(&bpf_event_mutex); 1103 1104 if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) || 1105 copy_to_user(uquery->ids, ids, ids_len * sizeof(u32))) 1106 ret = -EFAULT; 1107 1108 kfree(ids); 1109 return ret; 1110 } 1111 1112 extern struct bpf_raw_event_map __start__bpf_raw_tp[]; 1113 extern struct bpf_raw_event_map __stop__bpf_raw_tp[]; 1114 1115 struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name) 1116 { 1117 struct bpf_raw_event_map *btp = __start__bpf_raw_tp; 1118 1119 for (; btp < __stop__bpf_raw_tp; btp++) { 1120 if (!strcmp(btp->tp->name, name)) 1121 return btp; 1122 } 1123 1124 return bpf_get_raw_tracepoint_module(name); 1125 } 1126 1127 void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp) 1128 { 1129 struct module *mod = __module_address((unsigned long)btp); 1130 1131 if (mod) 1132 module_put(mod); 1133 } 1134 1135 static __always_inline 1136 void __bpf_trace_run(struct bpf_prog *prog, u64 *args) 1137 { 1138 rcu_read_lock(); 1139 preempt_disable(); 1140 (void) BPF_PROG_RUN(prog, args); 1141 preempt_enable(); 1142 rcu_read_unlock(); 1143 } 1144 1145 #define UNPACK(...) __VA_ARGS__ 1146 #define REPEAT_1(FN, DL, X, ...) FN(X) 1147 #define REPEAT_2(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__) 1148 #define REPEAT_3(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_2(FN, DL, __VA_ARGS__) 1149 #define REPEAT_4(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_3(FN, DL, __VA_ARGS__) 1150 #define REPEAT_5(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_4(FN, DL, __VA_ARGS__) 1151 #define REPEAT_6(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_5(FN, DL, __VA_ARGS__) 1152 #define REPEAT_7(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_6(FN, DL, __VA_ARGS__) 1153 #define REPEAT_8(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_7(FN, DL, __VA_ARGS__) 1154 #define REPEAT_9(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_8(FN, DL, __VA_ARGS__) 1155 #define REPEAT_10(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_9(FN, DL, __VA_ARGS__) 1156 #define REPEAT_11(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_10(FN, DL, __VA_ARGS__) 1157 #define REPEAT_12(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_11(FN, DL, __VA_ARGS__) 1158 #define REPEAT(X, FN, DL, ...) REPEAT_##X(FN, DL, __VA_ARGS__) 1159 1160 #define SARG(X) u64 arg##X 1161 #define COPY(X) args[X] = arg##X 1162 1163 #define __DL_COM (,) 1164 #define __DL_SEM (;) 1165 1166 #define __SEQ_0_11 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 1167 1168 #define BPF_TRACE_DEFN_x(x) \ 1169 void bpf_trace_run##x(struct bpf_prog *prog, \ 1170 REPEAT(x, SARG, __DL_COM, __SEQ_0_11)) \ 1171 { \ 1172 u64 args[x]; \ 1173 REPEAT(x, COPY, __DL_SEM, __SEQ_0_11); \ 1174 __bpf_trace_run(prog, args); \ 1175 } \ 1176 EXPORT_SYMBOL_GPL(bpf_trace_run##x) 1177 BPF_TRACE_DEFN_x(1); 1178 BPF_TRACE_DEFN_x(2); 1179 BPF_TRACE_DEFN_x(3); 1180 BPF_TRACE_DEFN_x(4); 1181 BPF_TRACE_DEFN_x(5); 1182 BPF_TRACE_DEFN_x(6); 1183 BPF_TRACE_DEFN_x(7); 1184 BPF_TRACE_DEFN_x(8); 1185 BPF_TRACE_DEFN_x(9); 1186 BPF_TRACE_DEFN_x(10); 1187 BPF_TRACE_DEFN_x(11); 1188 BPF_TRACE_DEFN_x(12); 1189 1190 static int __bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog) 1191 { 1192 struct tracepoint *tp = btp->tp; 1193 1194 /* 1195 * check that program doesn't access arguments beyond what's 1196 * available in this tracepoint 1197 */ 1198 if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64)) 1199 return -EINVAL; 1200 1201 return tracepoint_probe_register(tp, (void *)btp->bpf_func, prog); 1202 } 1203 1204 int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog) 1205 { 1206 return __bpf_probe_register(btp, prog); 1207 } 1208 1209 int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_prog *prog) 1210 { 1211 return tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, prog); 1212 } 1213 1214 int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id, 1215 u32 *fd_type, const char **buf, 1216 u64 *probe_offset, u64 *probe_addr) 1217 { 1218 bool is_tracepoint, is_syscall_tp; 1219 struct bpf_prog *prog; 1220 int flags, err = 0; 1221 1222 prog = event->prog; 1223 if (!prog) 1224 return -ENOENT; 1225 1226 /* not supporting BPF_PROG_TYPE_PERF_EVENT yet */ 1227 if (prog->type == BPF_PROG_TYPE_PERF_EVENT) 1228 return -EOPNOTSUPP; 1229 1230 *prog_id = prog->aux->id; 1231 flags = event->tp_event->flags; 1232 is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT; 1233 is_syscall_tp = is_syscall_trace_event(event->tp_event); 1234 1235 if (is_tracepoint || is_syscall_tp) { 1236 *buf = is_tracepoint ? event->tp_event->tp->name 1237 : event->tp_event->name; 1238 *fd_type = BPF_FD_TYPE_TRACEPOINT; 1239 *probe_offset = 0x0; 1240 *probe_addr = 0x0; 1241 } else { 1242 /* kprobe/uprobe */ 1243 err = -EOPNOTSUPP; 1244 #ifdef CONFIG_KPROBE_EVENTS 1245 if (flags & TRACE_EVENT_FL_KPROBE) 1246 err = bpf_get_kprobe_info(event, fd_type, buf, 1247 probe_offset, probe_addr, 1248 event->attr.type == PERF_TYPE_TRACEPOINT); 1249 #endif 1250 #ifdef CONFIG_UPROBE_EVENTS 1251 if (flags & TRACE_EVENT_FL_UPROBE) 1252 err = bpf_get_uprobe_info(event, fd_type, buf, 1253 probe_offset, 1254 event->attr.type == PERF_TYPE_TRACEPOINT); 1255 #endif 1256 } 1257 1258 return err; 1259 } 1260 1261 #ifdef CONFIG_MODULES 1262 int bpf_event_notify(struct notifier_block *nb, unsigned long op, void *module) 1263 { 1264 struct bpf_trace_module *btm, *tmp; 1265 struct module *mod = module; 1266 1267 if (mod->num_bpf_raw_events == 0 || 1268 (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING)) 1269 return 0; 1270 1271 mutex_lock(&bpf_module_mutex); 1272 1273 switch (op) { 1274 case MODULE_STATE_COMING: 1275 btm = kzalloc(sizeof(*btm), GFP_KERNEL); 1276 if (btm) { 1277 btm->module = module; 1278 list_add(&btm->list, &bpf_trace_modules); 1279 } 1280 break; 1281 case MODULE_STATE_GOING: 1282 list_for_each_entry_safe(btm, tmp, &bpf_trace_modules, list) { 1283 if (btm->module == module) { 1284 list_del(&btm->list); 1285 kfree(btm); 1286 break; 1287 } 1288 } 1289 break; 1290 } 1291 1292 mutex_unlock(&bpf_module_mutex); 1293 1294 return 0; 1295 } 1296 1297 static struct notifier_block bpf_module_nb = { 1298 .notifier_call = bpf_event_notify, 1299 }; 1300 1301 int __init bpf_event_init(void) 1302 { 1303 register_module_notifier(&bpf_module_nb); 1304 return 0; 1305 } 1306 1307 fs_initcall(bpf_event_init); 1308 #endif /* CONFIG_MODULES */ 1309