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_map_push_elem: 573 return &bpf_map_push_elem_proto; 574 case BPF_FUNC_map_pop_elem: 575 return &bpf_map_pop_elem_proto; 576 case BPF_FUNC_map_peek_elem: 577 return &bpf_map_peek_elem_proto; 578 case BPF_FUNC_probe_read: 579 return &bpf_probe_read_proto; 580 case BPF_FUNC_ktime_get_ns: 581 return &bpf_ktime_get_ns_proto; 582 case BPF_FUNC_tail_call: 583 return &bpf_tail_call_proto; 584 case BPF_FUNC_get_current_pid_tgid: 585 return &bpf_get_current_pid_tgid_proto; 586 case BPF_FUNC_get_current_task: 587 return &bpf_get_current_task_proto; 588 case BPF_FUNC_get_current_uid_gid: 589 return &bpf_get_current_uid_gid_proto; 590 case BPF_FUNC_get_current_comm: 591 return &bpf_get_current_comm_proto; 592 case BPF_FUNC_trace_printk: 593 return bpf_get_trace_printk_proto(); 594 case BPF_FUNC_get_smp_processor_id: 595 return &bpf_get_smp_processor_id_proto; 596 case BPF_FUNC_get_numa_node_id: 597 return &bpf_get_numa_node_id_proto; 598 case BPF_FUNC_perf_event_read: 599 return &bpf_perf_event_read_proto; 600 case BPF_FUNC_probe_write_user: 601 return bpf_get_probe_write_proto(); 602 case BPF_FUNC_current_task_under_cgroup: 603 return &bpf_current_task_under_cgroup_proto; 604 case BPF_FUNC_get_prandom_u32: 605 return &bpf_get_prandom_u32_proto; 606 case BPF_FUNC_probe_read_str: 607 return &bpf_probe_read_str_proto; 608 #ifdef CONFIG_CGROUPS 609 case BPF_FUNC_get_current_cgroup_id: 610 return &bpf_get_current_cgroup_id_proto; 611 #endif 612 default: 613 return NULL; 614 } 615 } 616 617 static const struct bpf_func_proto * 618 kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 619 { 620 switch (func_id) { 621 case BPF_FUNC_perf_event_output: 622 return &bpf_perf_event_output_proto; 623 case BPF_FUNC_get_stackid: 624 return &bpf_get_stackid_proto; 625 case BPF_FUNC_get_stack: 626 return &bpf_get_stack_proto; 627 case BPF_FUNC_perf_event_read_value: 628 return &bpf_perf_event_read_value_proto; 629 #ifdef CONFIG_BPF_KPROBE_OVERRIDE 630 case BPF_FUNC_override_return: 631 return &bpf_override_return_proto; 632 #endif 633 default: 634 return tracing_func_proto(func_id, prog); 635 } 636 } 637 638 /* bpf+kprobe programs can access fields of 'struct pt_regs' */ 639 static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type, 640 const struct bpf_prog *prog, 641 struct bpf_insn_access_aux *info) 642 { 643 if (off < 0 || off >= sizeof(struct pt_regs)) 644 return false; 645 if (type != BPF_READ) 646 return false; 647 if (off % size != 0) 648 return false; 649 /* 650 * Assertion for 32 bit to make sure last 8 byte access 651 * (BPF_DW) to the last 4 byte member is disallowed. 652 */ 653 if (off + size > sizeof(struct pt_regs)) 654 return false; 655 656 return true; 657 } 658 659 const struct bpf_verifier_ops kprobe_verifier_ops = { 660 .get_func_proto = kprobe_prog_func_proto, 661 .is_valid_access = kprobe_prog_is_valid_access, 662 }; 663 664 const struct bpf_prog_ops kprobe_prog_ops = { 665 }; 666 667 BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map, 668 u64, flags, void *, data, u64, size) 669 { 670 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 671 672 /* 673 * r1 points to perf tracepoint buffer where first 8 bytes are hidden 674 * from bpf program and contain a pointer to 'struct pt_regs'. Fetch it 675 * from there and call the same bpf_perf_event_output() helper inline. 676 */ 677 return ____bpf_perf_event_output(regs, map, flags, data, size); 678 } 679 680 static const struct bpf_func_proto bpf_perf_event_output_proto_tp = { 681 .func = bpf_perf_event_output_tp, 682 .gpl_only = true, 683 .ret_type = RET_INTEGER, 684 .arg1_type = ARG_PTR_TO_CTX, 685 .arg2_type = ARG_CONST_MAP_PTR, 686 .arg3_type = ARG_ANYTHING, 687 .arg4_type = ARG_PTR_TO_MEM, 688 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 689 }; 690 691 BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map, 692 u64, flags) 693 { 694 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 695 696 /* 697 * Same comment as in bpf_perf_event_output_tp(), only that this time 698 * the other helper's function body cannot be inlined due to being 699 * external, thus we need to call raw helper function. 700 */ 701 return bpf_get_stackid((unsigned long) regs, (unsigned long) map, 702 flags, 0, 0); 703 } 704 705 static const struct bpf_func_proto bpf_get_stackid_proto_tp = { 706 .func = bpf_get_stackid_tp, 707 .gpl_only = true, 708 .ret_type = RET_INTEGER, 709 .arg1_type = ARG_PTR_TO_CTX, 710 .arg2_type = ARG_CONST_MAP_PTR, 711 .arg3_type = ARG_ANYTHING, 712 }; 713 714 BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size, 715 u64, flags) 716 { 717 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 718 719 return bpf_get_stack((unsigned long) regs, (unsigned long) buf, 720 (unsigned long) size, flags, 0); 721 } 722 723 static const struct bpf_func_proto bpf_get_stack_proto_tp = { 724 .func = bpf_get_stack_tp, 725 .gpl_only = true, 726 .ret_type = RET_INTEGER, 727 .arg1_type = ARG_PTR_TO_CTX, 728 .arg2_type = ARG_PTR_TO_UNINIT_MEM, 729 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 730 .arg4_type = ARG_ANYTHING, 731 }; 732 733 static const struct bpf_func_proto * 734 tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 735 { 736 switch (func_id) { 737 case BPF_FUNC_perf_event_output: 738 return &bpf_perf_event_output_proto_tp; 739 case BPF_FUNC_get_stackid: 740 return &bpf_get_stackid_proto_tp; 741 case BPF_FUNC_get_stack: 742 return &bpf_get_stack_proto_tp; 743 default: 744 return tracing_func_proto(func_id, prog); 745 } 746 } 747 748 static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type, 749 const struct bpf_prog *prog, 750 struct bpf_insn_access_aux *info) 751 { 752 if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE) 753 return false; 754 if (type != BPF_READ) 755 return false; 756 if (off % size != 0) 757 return false; 758 759 BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(__u64)); 760 return true; 761 } 762 763 const struct bpf_verifier_ops tracepoint_verifier_ops = { 764 .get_func_proto = tp_prog_func_proto, 765 .is_valid_access = tp_prog_is_valid_access, 766 }; 767 768 const struct bpf_prog_ops tracepoint_prog_ops = { 769 }; 770 771 BPF_CALL_3(bpf_perf_prog_read_value, struct bpf_perf_event_data_kern *, ctx, 772 struct bpf_perf_event_value *, buf, u32, size) 773 { 774 int err = -EINVAL; 775 776 if (unlikely(size != sizeof(struct bpf_perf_event_value))) 777 goto clear; 778 err = perf_event_read_local(ctx->event, &buf->counter, &buf->enabled, 779 &buf->running); 780 if (unlikely(err)) 781 goto clear; 782 return 0; 783 clear: 784 memset(buf, 0, size); 785 return err; 786 } 787 788 static const struct bpf_func_proto bpf_perf_prog_read_value_proto = { 789 .func = bpf_perf_prog_read_value, 790 .gpl_only = true, 791 .ret_type = RET_INTEGER, 792 .arg1_type = ARG_PTR_TO_CTX, 793 .arg2_type = ARG_PTR_TO_UNINIT_MEM, 794 .arg3_type = ARG_CONST_SIZE, 795 }; 796 797 static const struct bpf_func_proto * 798 pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 799 { 800 switch (func_id) { 801 case BPF_FUNC_perf_event_output: 802 return &bpf_perf_event_output_proto_tp; 803 case BPF_FUNC_get_stackid: 804 return &bpf_get_stackid_proto_tp; 805 case BPF_FUNC_get_stack: 806 return &bpf_get_stack_proto_tp; 807 case BPF_FUNC_perf_prog_read_value: 808 return &bpf_perf_prog_read_value_proto; 809 default: 810 return tracing_func_proto(func_id, prog); 811 } 812 } 813 814 /* 815 * bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp 816 * to avoid potential recursive reuse issue when/if tracepoints are added 817 * inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack 818 */ 819 static DEFINE_PER_CPU(struct pt_regs, bpf_raw_tp_regs); 820 BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args, 821 struct bpf_map *, map, u64, flags, void *, data, u64, size) 822 { 823 struct pt_regs *regs = this_cpu_ptr(&bpf_raw_tp_regs); 824 825 perf_fetch_caller_regs(regs); 826 return ____bpf_perf_event_output(regs, map, flags, data, size); 827 } 828 829 static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = { 830 .func = bpf_perf_event_output_raw_tp, 831 .gpl_only = true, 832 .ret_type = RET_INTEGER, 833 .arg1_type = ARG_PTR_TO_CTX, 834 .arg2_type = ARG_CONST_MAP_PTR, 835 .arg3_type = ARG_ANYTHING, 836 .arg4_type = ARG_PTR_TO_MEM, 837 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 838 }; 839 840 BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args, 841 struct bpf_map *, map, u64, flags) 842 { 843 struct pt_regs *regs = this_cpu_ptr(&bpf_raw_tp_regs); 844 845 perf_fetch_caller_regs(regs); 846 /* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */ 847 return bpf_get_stackid((unsigned long) regs, (unsigned long) map, 848 flags, 0, 0); 849 } 850 851 static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = { 852 .func = bpf_get_stackid_raw_tp, 853 .gpl_only = true, 854 .ret_type = RET_INTEGER, 855 .arg1_type = ARG_PTR_TO_CTX, 856 .arg2_type = ARG_CONST_MAP_PTR, 857 .arg3_type = ARG_ANYTHING, 858 }; 859 860 BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args, 861 void *, buf, u32, size, u64, flags) 862 { 863 struct pt_regs *regs = this_cpu_ptr(&bpf_raw_tp_regs); 864 865 perf_fetch_caller_regs(regs); 866 return bpf_get_stack((unsigned long) regs, (unsigned long) buf, 867 (unsigned long) size, flags, 0); 868 } 869 870 static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = { 871 .func = bpf_get_stack_raw_tp, 872 .gpl_only = true, 873 .ret_type = RET_INTEGER, 874 .arg1_type = ARG_PTR_TO_CTX, 875 .arg2_type = ARG_PTR_TO_MEM, 876 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 877 .arg4_type = ARG_ANYTHING, 878 }; 879 880 static const struct bpf_func_proto * 881 raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 882 { 883 switch (func_id) { 884 case BPF_FUNC_perf_event_output: 885 return &bpf_perf_event_output_proto_raw_tp; 886 case BPF_FUNC_get_stackid: 887 return &bpf_get_stackid_proto_raw_tp; 888 case BPF_FUNC_get_stack: 889 return &bpf_get_stack_proto_raw_tp; 890 default: 891 return tracing_func_proto(func_id, prog); 892 } 893 } 894 895 static bool raw_tp_prog_is_valid_access(int off, int size, 896 enum bpf_access_type type, 897 const struct bpf_prog *prog, 898 struct bpf_insn_access_aux *info) 899 { 900 /* largest tracepoint in the kernel has 12 args */ 901 if (off < 0 || off >= sizeof(__u64) * 12) 902 return false; 903 if (type != BPF_READ) 904 return false; 905 if (off % size != 0) 906 return false; 907 return true; 908 } 909 910 const struct bpf_verifier_ops raw_tracepoint_verifier_ops = { 911 .get_func_proto = raw_tp_prog_func_proto, 912 .is_valid_access = raw_tp_prog_is_valid_access, 913 }; 914 915 const struct bpf_prog_ops raw_tracepoint_prog_ops = { 916 }; 917 918 static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type, 919 const struct bpf_prog *prog, 920 struct bpf_insn_access_aux *info) 921 { 922 const int size_u64 = sizeof(u64); 923 924 if (off < 0 || off >= sizeof(struct bpf_perf_event_data)) 925 return false; 926 if (type != BPF_READ) 927 return false; 928 if (off % size != 0) { 929 if (sizeof(unsigned long) != 4) 930 return false; 931 if (size != 8) 932 return false; 933 if (off % size != 4) 934 return false; 935 } 936 937 switch (off) { 938 case bpf_ctx_range(struct bpf_perf_event_data, sample_period): 939 bpf_ctx_record_field_size(info, size_u64); 940 if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) 941 return false; 942 break; 943 case bpf_ctx_range(struct bpf_perf_event_data, addr): 944 bpf_ctx_record_field_size(info, size_u64); 945 if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) 946 return false; 947 break; 948 default: 949 if (size != sizeof(long)) 950 return false; 951 } 952 953 return true; 954 } 955 956 static u32 pe_prog_convert_ctx_access(enum bpf_access_type type, 957 const struct bpf_insn *si, 958 struct bpf_insn *insn_buf, 959 struct bpf_prog *prog, u32 *target_size) 960 { 961 struct bpf_insn *insn = insn_buf; 962 963 switch (si->off) { 964 case offsetof(struct bpf_perf_event_data, sample_period): 965 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 966 data), si->dst_reg, si->src_reg, 967 offsetof(struct bpf_perf_event_data_kern, data)); 968 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, 969 bpf_target_off(struct perf_sample_data, period, 8, 970 target_size)); 971 break; 972 case offsetof(struct bpf_perf_event_data, addr): 973 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 974 data), si->dst_reg, si->src_reg, 975 offsetof(struct bpf_perf_event_data_kern, data)); 976 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, 977 bpf_target_off(struct perf_sample_data, addr, 8, 978 target_size)); 979 break; 980 default: 981 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 982 regs), si->dst_reg, si->src_reg, 983 offsetof(struct bpf_perf_event_data_kern, regs)); 984 *insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg, 985 si->off); 986 break; 987 } 988 989 return insn - insn_buf; 990 } 991 992 const struct bpf_verifier_ops perf_event_verifier_ops = { 993 .get_func_proto = pe_prog_func_proto, 994 .is_valid_access = pe_prog_is_valid_access, 995 .convert_ctx_access = pe_prog_convert_ctx_access, 996 }; 997 998 const struct bpf_prog_ops perf_event_prog_ops = { 999 }; 1000 1001 static DEFINE_MUTEX(bpf_event_mutex); 1002 1003 #define BPF_TRACE_MAX_PROGS 64 1004 1005 int perf_event_attach_bpf_prog(struct perf_event *event, 1006 struct bpf_prog *prog) 1007 { 1008 struct bpf_prog_array __rcu *old_array; 1009 struct bpf_prog_array *new_array; 1010 int ret = -EEXIST; 1011 1012 /* 1013 * Kprobe override only works if they are on the function entry, 1014 * and only if they are on the opt-in list. 1015 */ 1016 if (prog->kprobe_override && 1017 (!trace_kprobe_on_func_entry(event->tp_event) || 1018 !trace_kprobe_error_injectable(event->tp_event))) 1019 return -EINVAL; 1020 1021 mutex_lock(&bpf_event_mutex); 1022 1023 if (event->prog) 1024 goto unlock; 1025 1026 old_array = event->tp_event->prog_array; 1027 if (old_array && 1028 bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) { 1029 ret = -E2BIG; 1030 goto unlock; 1031 } 1032 1033 ret = bpf_prog_array_copy(old_array, NULL, prog, &new_array); 1034 if (ret < 0) 1035 goto unlock; 1036 1037 /* set the new array to event->tp_event and set event->prog */ 1038 event->prog = prog; 1039 rcu_assign_pointer(event->tp_event->prog_array, new_array); 1040 bpf_prog_array_free(old_array); 1041 1042 unlock: 1043 mutex_unlock(&bpf_event_mutex); 1044 return ret; 1045 } 1046 1047 void perf_event_detach_bpf_prog(struct perf_event *event) 1048 { 1049 struct bpf_prog_array __rcu *old_array; 1050 struct bpf_prog_array *new_array; 1051 int ret; 1052 1053 mutex_lock(&bpf_event_mutex); 1054 1055 if (!event->prog) 1056 goto unlock; 1057 1058 old_array = event->tp_event->prog_array; 1059 ret = bpf_prog_array_copy(old_array, event->prog, NULL, &new_array); 1060 if (ret == -ENOENT) 1061 goto unlock; 1062 if (ret < 0) { 1063 bpf_prog_array_delete_safe(old_array, event->prog); 1064 } else { 1065 rcu_assign_pointer(event->tp_event->prog_array, new_array); 1066 bpf_prog_array_free(old_array); 1067 } 1068 1069 bpf_prog_put(event->prog); 1070 event->prog = NULL; 1071 1072 unlock: 1073 mutex_unlock(&bpf_event_mutex); 1074 } 1075 1076 int perf_event_query_prog_array(struct perf_event *event, void __user *info) 1077 { 1078 struct perf_event_query_bpf __user *uquery = info; 1079 struct perf_event_query_bpf query = {}; 1080 u32 *ids, prog_cnt, ids_len; 1081 int ret; 1082 1083 if (!capable(CAP_SYS_ADMIN)) 1084 return -EPERM; 1085 if (event->attr.type != PERF_TYPE_TRACEPOINT) 1086 return -EINVAL; 1087 if (copy_from_user(&query, uquery, sizeof(query))) 1088 return -EFAULT; 1089 1090 ids_len = query.ids_len; 1091 if (ids_len > BPF_TRACE_MAX_PROGS) 1092 return -E2BIG; 1093 ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN); 1094 if (!ids) 1095 return -ENOMEM; 1096 /* 1097 * The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which 1098 * is required when user only wants to check for uquery->prog_cnt. 1099 * There is no need to check for it since the case is handled 1100 * gracefully in bpf_prog_array_copy_info. 1101 */ 1102 1103 mutex_lock(&bpf_event_mutex); 1104 ret = bpf_prog_array_copy_info(event->tp_event->prog_array, 1105 ids, 1106 ids_len, 1107 &prog_cnt); 1108 mutex_unlock(&bpf_event_mutex); 1109 1110 if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) || 1111 copy_to_user(uquery->ids, ids, ids_len * sizeof(u32))) 1112 ret = -EFAULT; 1113 1114 kfree(ids); 1115 return ret; 1116 } 1117 1118 extern struct bpf_raw_event_map __start__bpf_raw_tp[]; 1119 extern struct bpf_raw_event_map __stop__bpf_raw_tp[]; 1120 1121 struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name) 1122 { 1123 struct bpf_raw_event_map *btp = __start__bpf_raw_tp; 1124 1125 for (; btp < __stop__bpf_raw_tp; btp++) { 1126 if (!strcmp(btp->tp->name, name)) 1127 return btp; 1128 } 1129 1130 return bpf_get_raw_tracepoint_module(name); 1131 } 1132 1133 void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp) 1134 { 1135 struct module *mod = __module_address((unsigned long)btp); 1136 1137 if (mod) 1138 module_put(mod); 1139 } 1140 1141 static __always_inline 1142 void __bpf_trace_run(struct bpf_prog *prog, u64 *args) 1143 { 1144 rcu_read_lock(); 1145 preempt_disable(); 1146 (void) BPF_PROG_RUN(prog, args); 1147 preempt_enable(); 1148 rcu_read_unlock(); 1149 } 1150 1151 #define UNPACK(...) __VA_ARGS__ 1152 #define REPEAT_1(FN, DL, X, ...) FN(X) 1153 #define REPEAT_2(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__) 1154 #define REPEAT_3(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_2(FN, DL, __VA_ARGS__) 1155 #define REPEAT_4(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_3(FN, DL, __VA_ARGS__) 1156 #define REPEAT_5(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_4(FN, DL, __VA_ARGS__) 1157 #define REPEAT_6(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_5(FN, DL, __VA_ARGS__) 1158 #define REPEAT_7(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_6(FN, DL, __VA_ARGS__) 1159 #define REPEAT_8(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_7(FN, DL, __VA_ARGS__) 1160 #define REPEAT_9(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_8(FN, DL, __VA_ARGS__) 1161 #define REPEAT_10(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_9(FN, DL, __VA_ARGS__) 1162 #define REPEAT_11(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_10(FN, DL, __VA_ARGS__) 1163 #define REPEAT_12(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_11(FN, DL, __VA_ARGS__) 1164 #define REPEAT(X, FN, DL, ...) REPEAT_##X(FN, DL, __VA_ARGS__) 1165 1166 #define SARG(X) u64 arg##X 1167 #define COPY(X) args[X] = arg##X 1168 1169 #define __DL_COM (,) 1170 #define __DL_SEM (;) 1171 1172 #define __SEQ_0_11 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 1173 1174 #define BPF_TRACE_DEFN_x(x) \ 1175 void bpf_trace_run##x(struct bpf_prog *prog, \ 1176 REPEAT(x, SARG, __DL_COM, __SEQ_0_11)) \ 1177 { \ 1178 u64 args[x]; \ 1179 REPEAT(x, COPY, __DL_SEM, __SEQ_0_11); \ 1180 __bpf_trace_run(prog, args); \ 1181 } \ 1182 EXPORT_SYMBOL_GPL(bpf_trace_run##x) 1183 BPF_TRACE_DEFN_x(1); 1184 BPF_TRACE_DEFN_x(2); 1185 BPF_TRACE_DEFN_x(3); 1186 BPF_TRACE_DEFN_x(4); 1187 BPF_TRACE_DEFN_x(5); 1188 BPF_TRACE_DEFN_x(6); 1189 BPF_TRACE_DEFN_x(7); 1190 BPF_TRACE_DEFN_x(8); 1191 BPF_TRACE_DEFN_x(9); 1192 BPF_TRACE_DEFN_x(10); 1193 BPF_TRACE_DEFN_x(11); 1194 BPF_TRACE_DEFN_x(12); 1195 1196 static int __bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog) 1197 { 1198 struct tracepoint *tp = btp->tp; 1199 1200 /* 1201 * check that program doesn't access arguments beyond what's 1202 * available in this tracepoint 1203 */ 1204 if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64)) 1205 return -EINVAL; 1206 1207 return tracepoint_probe_register(tp, (void *)btp->bpf_func, prog); 1208 } 1209 1210 int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog) 1211 { 1212 return __bpf_probe_register(btp, prog); 1213 } 1214 1215 int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_prog *prog) 1216 { 1217 return tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, prog); 1218 } 1219 1220 int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id, 1221 u32 *fd_type, const char **buf, 1222 u64 *probe_offset, u64 *probe_addr) 1223 { 1224 bool is_tracepoint, is_syscall_tp; 1225 struct bpf_prog *prog; 1226 int flags, err = 0; 1227 1228 prog = event->prog; 1229 if (!prog) 1230 return -ENOENT; 1231 1232 /* not supporting BPF_PROG_TYPE_PERF_EVENT yet */ 1233 if (prog->type == BPF_PROG_TYPE_PERF_EVENT) 1234 return -EOPNOTSUPP; 1235 1236 *prog_id = prog->aux->id; 1237 flags = event->tp_event->flags; 1238 is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT; 1239 is_syscall_tp = is_syscall_trace_event(event->tp_event); 1240 1241 if (is_tracepoint || is_syscall_tp) { 1242 *buf = is_tracepoint ? event->tp_event->tp->name 1243 : event->tp_event->name; 1244 *fd_type = BPF_FD_TYPE_TRACEPOINT; 1245 *probe_offset = 0x0; 1246 *probe_addr = 0x0; 1247 } else { 1248 /* kprobe/uprobe */ 1249 err = -EOPNOTSUPP; 1250 #ifdef CONFIG_KPROBE_EVENTS 1251 if (flags & TRACE_EVENT_FL_KPROBE) 1252 err = bpf_get_kprobe_info(event, fd_type, buf, 1253 probe_offset, probe_addr, 1254 event->attr.type == PERF_TYPE_TRACEPOINT); 1255 #endif 1256 #ifdef CONFIG_UPROBE_EVENTS 1257 if (flags & TRACE_EVENT_FL_UPROBE) 1258 err = bpf_get_uprobe_info(event, fd_type, buf, 1259 probe_offset, 1260 event->attr.type == PERF_TYPE_TRACEPOINT); 1261 #endif 1262 } 1263 1264 return err; 1265 } 1266 1267 #ifdef CONFIG_MODULES 1268 int bpf_event_notify(struct notifier_block *nb, unsigned long op, void *module) 1269 { 1270 struct bpf_trace_module *btm, *tmp; 1271 struct module *mod = module; 1272 1273 if (mod->num_bpf_raw_events == 0 || 1274 (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING)) 1275 return 0; 1276 1277 mutex_lock(&bpf_module_mutex); 1278 1279 switch (op) { 1280 case MODULE_STATE_COMING: 1281 btm = kzalloc(sizeof(*btm), GFP_KERNEL); 1282 if (btm) { 1283 btm->module = module; 1284 list_add(&btm->list, &bpf_trace_modules); 1285 } 1286 break; 1287 case MODULE_STATE_GOING: 1288 list_for_each_entry_safe(btm, tmp, &bpf_trace_modules, list) { 1289 if (btm->module == module) { 1290 list_del(&btm->list); 1291 kfree(btm); 1292 break; 1293 } 1294 } 1295 break; 1296 } 1297 1298 mutex_unlock(&bpf_module_mutex); 1299 1300 return 0; 1301 } 1302 1303 static struct notifier_block bpf_module_nb = { 1304 .notifier_call = bpf_event_notify, 1305 }; 1306 1307 int __init bpf_event_init(void) 1308 { 1309 register_module_notifier(&bpf_module_nb); 1310 return 0; 1311 } 1312 1313 fs_initcall(bpf_event_init); 1314 #endif /* CONFIG_MODULES */ 1315