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 perf_event_output(event, sd, regs); 435 return 0; 436 } 437 438 BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map, 439 u64, flags, void *, data, u64, size) 440 { 441 struct perf_sample_data *sd = this_cpu_ptr(&bpf_trace_sd); 442 struct perf_raw_record raw = { 443 .frag = { 444 .size = size, 445 .data = data, 446 }, 447 }; 448 449 if (unlikely(flags & ~(BPF_F_INDEX_MASK))) 450 return -EINVAL; 451 452 perf_sample_data_init(sd, 0, 0); 453 sd->raw = &raw; 454 455 return __bpf_perf_event_output(regs, map, flags, sd); 456 } 457 458 static const struct bpf_func_proto bpf_perf_event_output_proto = { 459 .func = bpf_perf_event_output, 460 .gpl_only = true, 461 .ret_type = RET_INTEGER, 462 .arg1_type = ARG_PTR_TO_CTX, 463 .arg2_type = ARG_CONST_MAP_PTR, 464 .arg3_type = ARG_ANYTHING, 465 .arg4_type = ARG_PTR_TO_MEM, 466 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 467 }; 468 469 static DEFINE_PER_CPU(struct pt_regs, bpf_pt_regs); 470 static DEFINE_PER_CPU(struct perf_sample_data, bpf_misc_sd); 471 472 u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size, 473 void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy) 474 { 475 struct perf_sample_data *sd = this_cpu_ptr(&bpf_misc_sd); 476 struct pt_regs *regs = this_cpu_ptr(&bpf_pt_regs); 477 struct perf_raw_frag frag = { 478 .copy = ctx_copy, 479 .size = ctx_size, 480 .data = ctx, 481 }; 482 struct perf_raw_record raw = { 483 .frag = { 484 { 485 .next = ctx_size ? &frag : NULL, 486 }, 487 .size = meta_size, 488 .data = meta, 489 }, 490 }; 491 492 perf_fetch_caller_regs(regs); 493 perf_sample_data_init(sd, 0, 0); 494 sd->raw = &raw; 495 496 return __bpf_perf_event_output(regs, map, flags, sd); 497 } 498 499 BPF_CALL_0(bpf_get_current_task) 500 { 501 return (long) current; 502 } 503 504 static const struct bpf_func_proto bpf_get_current_task_proto = { 505 .func = bpf_get_current_task, 506 .gpl_only = true, 507 .ret_type = RET_INTEGER, 508 }; 509 510 BPF_CALL_2(bpf_current_task_under_cgroup, struct bpf_map *, map, u32, idx) 511 { 512 struct bpf_array *array = container_of(map, struct bpf_array, map); 513 struct cgroup *cgrp; 514 515 if (unlikely(idx >= array->map.max_entries)) 516 return -E2BIG; 517 518 cgrp = READ_ONCE(array->ptrs[idx]); 519 if (unlikely(!cgrp)) 520 return -EAGAIN; 521 522 return task_under_cgroup_hierarchy(current, cgrp); 523 } 524 525 static const struct bpf_func_proto bpf_current_task_under_cgroup_proto = { 526 .func = bpf_current_task_under_cgroup, 527 .gpl_only = false, 528 .ret_type = RET_INTEGER, 529 .arg1_type = ARG_CONST_MAP_PTR, 530 .arg2_type = ARG_ANYTHING, 531 }; 532 533 BPF_CALL_3(bpf_probe_read_str, void *, dst, u32, size, 534 const void *, unsafe_ptr) 535 { 536 int ret; 537 538 /* 539 * The strncpy_from_unsafe() call will likely not fill the entire 540 * buffer, but that's okay in this circumstance as we're probing 541 * arbitrary memory anyway similar to bpf_probe_read() and might 542 * as well probe the stack. Thus, memory is explicitly cleared 543 * only in error case, so that improper users ignoring return 544 * code altogether don't copy garbage; otherwise length of string 545 * is returned that can be used for bpf_perf_event_output() et al. 546 */ 547 ret = strncpy_from_unsafe(dst, unsafe_ptr, size); 548 if (unlikely(ret < 0)) 549 memset(dst, 0, size); 550 551 return ret; 552 } 553 554 static const struct bpf_func_proto bpf_probe_read_str_proto = { 555 .func = bpf_probe_read_str, 556 .gpl_only = true, 557 .ret_type = RET_INTEGER, 558 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 559 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 560 .arg3_type = ARG_ANYTHING, 561 }; 562 563 static const struct bpf_func_proto * 564 tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 565 { 566 switch (func_id) { 567 case BPF_FUNC_map_lookup_elem: 568 return &bpf_map_lookup_elem_proto; 569 case BPF_FUNC_map_update_elem: 570 return &bpf_map_update_elem_proto; 571 case BPF_FUNC_map_delete_elem: 572 return &bpf_map_delete_elem_proto; 573 case BPF_FUNC_probe_read: 574 return &bpf_probe_read_proto; 575 case BPF_FUNC_ktime_get_ns: 576 return &bpf_ktime_get_ns_proto; 577 case BPF_FUNC_tail_call: 578 return &bpf_tail_call_proto; 579 case BPF_FUNC_get_current_pid_tgid: 580 return &bpf_get_current_pid_tgid_proto; 581 case BPF_FUNC_get_current_task: 582 return &bpf_get_current_task_proto; 583 case BPF_FUNC_get_current_uid_gid: 584 return &bpf_get_current_uid_gid_proto; 585 case BPF_FUNC_get_current_comm: 586 return &bpf_get_current_comm_proto; 587 case BPF_FUNC_trace_printk: 588 return bpf_get_trace_printk_proto(); 589 case BPF_FUNC_get_smp_processor_id: 590 return &bpf_get_smp_processor_id_proto; 591 case BPF_FUNC_get_numa_node_id: 592 return &bpf_get_numa_node_id_proto; 593 case BPF_FUNC_perf_event_read: 594 return &bpf_perf_event_read_proto; 595 case BPF_FUNC_probe_write_user: 596 return bpf_get_probe_write_proto(); 597 case BPF_FUNC_current_task_under_cgroup: 598 return &bpf_current_task_under_cgroup_proto; 599 case BPF_FUNC_get_prandom_u32: 600 return &bpf_get_prandom_u32_proto; 601 case BPF_FUNC_probe_read_str: 602 return &bpf_probe_read_str_proto; 603 #ifdef CONFIG_CGROUPS 604 case BPF_FUNC_get_current_cgroup_id: 605 return &bpf_get_current_cgroup_id_proto; 606 #endif 607 default: 608 return NULL; 609 } 610 } 611 612 static const struct bpf_func_proto * 613 kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 614 { 615 switch (func_id) { 616 case BPF_FUNC_perf_event_output: 617 return &bpf_perf_event_output_proto; 618 case BPF_FUNC_get_stackid: 619 return &bpf_get_stackid_proto; 620 case BPF_FUNC_get_stack: 621 return &bpf_get_stack_proto; 622 case BPF_FUNC_perf_event_read_value: 623 return &bpf_perf_event_read_value_proto; 624 #ifdef CONFIG_BPF_KPROBE_OVERRIDE 625 case BPF_FUNC_override_return: 626 return &bpf_override_return_proto; 627 #endif 628 default: 629 return tracing_func_proto(func_id, prog); 630 } 631 } 632 633 /* bpf+kprobe programs can access fields of 'struct pt_regs' */ 634 static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type, 635 const struct bpf_prog *prog, 636 struct bpf_insn_access_aux *info) 637 { 638 if (off < 0 || off >= sizeof(struct pt_regs)) 639 return false; 640 if (type != BPF_READ) 641 return false; 642 if (off % size != 0) 643 return false; 644 /* 645 * Assertion for 32 bit to make sure last 8 byte access 646 * (BPF_DW) to the last 4 byte member is disallowed. 647 */ 648 if (off + size > sizeof(struct pt_regs)) 649 return false; 650 651 return true; 652 } 653 654 const struct bpf_verifier_ops kprobe_verifier_ops = { 655 .get_func_proto = kprobe_prog_func_proto, 656 .is_valid_access = kprobe_prog_is_valid_access, 657 }; 658 659 const struct bpf_prog_ops kprobe_prog_ops = { 660 }; 661 662 BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map, 663 u64, flags, void *, data, u64, size) 664 { 665 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 666 667 /* 668 * r1 points to perf tracepoint buffer where first 8 bytes are hidden 669 * from bpf program and contain a pointer to 'struct pt_regs'. Fetch it 670 * from there and call the same bpf_perf_event_output() helper inline. 671 */ 672 return ____bpf_perf_event_output(regs, map, flags, data, size); 673 } 674 675 static const struct bpf_func_proto bpf_perf_event_output_proto_tp = { 676 .func = bpf_perf_event_output_tp, 677 .gpl_only = true, 678 .ret_type = RET_INTEGER, 679 .arg1_type = ARG_PTR_TO_CTX, 680 .arg2_type = ARG_CONST_MAP_PTR, 681 .arg3_type = ARG_ANYTHING, 682 .arg4_type = ARG_PTR_TO_MEM, 683 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 684 }; 685 686 BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map, 687 u64, flags) 688 { 689 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 690 691 /* 692 * Same comment as in bpf_perf_event_output_tp(), only that this time 693 * the other helper's function body cannot be inlined due to being 694 * external, thus we need to call raw helper function. 695 */ 696 return bpf_get_stackid((unsigned long) regs, (unsigned long) map, 697 flags, 0, 0); 698 } 699 700 static const struct bpf_func_proto bpf_get_stackid_proto_tp = { 701 .func = bpf_get_stackid_tp, 702 .gpl_only = true, 703 .ret_type = RET_INTEGER, 704 .arg1_type = ARG_PTR_TO_CTX, 705 .arg2_type = ARG_CONST_MAP_PTR, 706 .arg3_type = ARG_ANYTHING, 707 }; 708 709 BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size, 710 u64, flags) 711 { 712 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 713 714 return bpf_get_stack((unsigned long) regs, (unsigned long) buf, 715 (unsigned long) size, flags, 0); 716 } 717 718 static const struct bpf_func_proto bpf_get_stack_proto_tp = { 719 .func = bpf_get_stack_tp, 720 .gpl_only = true, 721 .ret_type = RET_INTEGER, 722 .arg1_type = ARG_PTR_TO_CTX, 723 .arg2_type = ARG_PTR_TO_UNINIT_MEM, 724 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 725 .arg4_type = ARG_ANYTHING, 726 }; 727 728 static const struct bpf_func_proto * 729 tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 730 { 731 switch (func_id) { 732 case BPF_FUNC_perf_event_output: 733 return &bpf_perf_event_output_proto_tp; 734 case BPF_FUNC_get_stackid: 735 return &bpf_get_stackid_proto_tp; 736 case BPF_FUNC_get_stack: 737 return &bpf_get_stack_proto_tp; 738 default: 739 return tracing_func_proto(func_id, prog); 740 } 741 } 742 743 static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type, 744 const struct bpf_prog *prog, 745 struct bpf_insn_access_aux *info) 746 { 747 if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE) 748 return false; 749 if (type != BPF_READ) 750 return false; 751 if (off % size != 0) 752 return false; 753 754 BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(__u64)); 755 return true; 756 } 757 758 const struct bpf_verifier_ops tracepoint_verifier_ops = { 759 .get_func_proto = tp_prog_func_proto, 760 .is_valid_access = tp_prog_is_valid_access, 761 }; 762 763 const struct bpf_prog_ops tracepoint_prog_ops = { 764 }; 765 766 BPF_CALL_3(bpf_perf_prog_read_value, struct bpf_perf_event_data_kern *, ctx, 767 struct bpf_perf_event_value *, buf, u32, size) 768 { 769 int err = -EINVAL; 770 771 if (unlikely(size != sizeof(struct bpf_perf_event_value))) 772 goto clear; 773 err = perf_event_read_local(ctx->event, &buf->counter, &buf->enabled, 774 &buf->running); 775 if (unlikely(err)) 776 goto clear; 777 return 0; 778 clear: 779 memset(buf, 0, size); 780 return err; 781 } 782 783 static const struct bpf_func_proto bpf_perf_prog_read_value_proto = { 784 .func = bpf_perf_prog_read_value, 785 .gpl_only = true, 786 .ret_type = RET_INTEGER, 787 .arg1_type = ARG_PTR_TO_CTX, 788 .arg2_type = ARG_PTR_TO_UNINIT_MEM, 789 .arg3_type = ARG_CONST_SIZE, 790 }; 791 792 static const struct bpf_func_proto * 793 pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 794 { 795 switch (func_id) { 796 case BPF_FUNC_perf_event_output: 797 return &bpf_perf_event_output_proto_tp; 798 case BPF_FUNC_get_stackid: 799 return &bpf_get_stackid_proto_tp; 800 case BPF_FUNC_get_stack: 801 return &bpf_get_stack_proto_tp; 802 case BPF_FUNC_perf_prog_read_value: 803 return &bpf_perf_prog_read_value_proto; 804 default: 805 return tracing_func_proto(func_id, prog); 806 } 807 } 808 809 /* 810 * bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp 811 * to avoid potential recursive reuse issue when/if tracepoints are added 812 * inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack 813 */ 814 static DEFINE_PER_CPU(struct pt_regs, bpf_raw_tp_regs); 815 BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args, 816 struct bpf_map *, map, u64, flags, void *, data, u64, size) 817 { 818 struct pt_regs *regs = this_cpu_ptr(&bpf_raw_tp_regs); 819 820 perf_fetch_caller_regs(regs); 821 return ____bpf_perf_event_output(regs, map, flags, data, size); 822 } 823 824 static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = { 825 .func = bpf_perf_event_output_raw_tp, 826 .gpl_only = true, 827 .ret_type = RET_INTEGER, 828 .arg1_type = ARG_PTR_TO_CTX, 829 .arg2_type = ARG_CONST_MAP_PTR, 830 .arg3_type = ARG_ANYTHING, 831 .arg4_type = ARG_PTR_TO_MEM, 832 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 833 }; 834 835 BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args, 836 struct bpf_map *, map, u64, flags) 837 { 838 struct pt_regs *regs = this_cpu_ptr(&bpf_raw_tp_regs); 839 840 perf_fetch_caller_regs(regs); 841 /* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */ 842 return bpf_get_stackid((unsigned long) regs, (unsigned long) map, 843 flags, 0, 0); 844 } 845 846 static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = { 847 .func = bpf_get_stackid_raw_tp, 848 .gpl_only = true, 849 .ret_type = RET_INTEGER, 850 .arg1_type = ARG_PTR_TO_CTX, 851 .arg2_type = ARG_CONST_MAP_PTR, 852 .arg3_type = ARG_ANYTHING, 853 }; 854 855 BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args, 856 void *, buf, u32, size, u64, flags) 857 { 858 struct pt_regs *regs = this_cpu_ptr(&bpf_raw_tp_regs); 859 860 perf_fetch_caller_regs(regs); 861 return bpf_get_stack((unsigned long) regs, (unsigned long) buf, 862 (unsigned long) size, flags, 0); 863 } 864 865 static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = { 866 .func = bpf_get_stack_raw_tp, 867 .gpl_only = true, 868 .ret_type = RET_INTEGER, 869 .arg1_type = ARG_PTR_TO_CTX, 870 .arg2_type = ARG_PTR_TO_MEM, 871 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 872 .arg4_type = ARG_ANYTHING, 873 }; 874 875 static const struct bpf_func_proto * 876 raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 877 { 878 switch (func_id) { 879 case BPF_FUNC_perf_event_output: 880 return &bpf_perf_event_output_proto_raw_tp; 881 case BPF_FUNC_get_stackid: 882 return &bpf_get_stackid_proto_raw_tp; 883 case BPF_FUNC_get_stack: 884 return &bpf_get_stack_proto_raw_tp; 885 default: 886 return tracing_func_proto(func_id, prog); 887 } 888 } 889 890 static bool raw_tp_prog_is_valid_access(int off, int size, 891 enum bpf_access_type type, 892 const struct bpf_prog *prog, 893 struct bpf_insn_access_aux *info) 894 { 895 /* largest tracepoint in the kernel has 12 args */ 896 if (off < 0 || off >= sizeof(__u64) * 12) 897 return false; 898 if (type != BPF_READ) 899 return false; 900 if (off % size != 0) 901 return false; 902 return true; 903 } 904 905 const struct bpf_verifier_ops raw_tracepoint_verifier_ops = { 906 .get_func_proto = raw_tp_prog_func_proto, 907 .is_valid_access = raw_tp_prog_is_valid_access, 908 }; 909 910 const struct bpf_prog_ops raw_tracepoint_prog_ops = { 911 }; 912 913 static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type, 914 const struct bpf_prog *prog, 915 struct bpf_insn_access_aux *info) 916 { 917 const int size_u64 = sizeof(u64); 918 919 if (off < 0 || off >= sizeof(struct bpf_perf_event_data)) 920 return false; 921 if (type != BPF_READ) 922 return false; 923 if (off % size != 0) { 924 if (sizeof(unsigned long) != 4) 925 return false; 926 if (size != 8) 927 return false; 928 if (off % size != 4) 929 return false; 930 } 931 932 switch (off) { 933 case bpf_ctx_range(struct bpf_perf_event_data, sample_period): 934 bpf_ctx_record_field_size(info, size_u64); 935 if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) 936 return false; 937 break; 938 case bpf_ctx_range(struct bpf_perf_event_data, addr): 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 default: 944 if (size != sizeof(long)) 945 return false; 946 } 947 948 return true; 949 } 950 951 static u32 pe_prog_convert_ctx_access(enum bpf_access_type type, 952 const struct bpf_insn *si, 953 struct bpf_insn *insn_buf, 954 struct bpf_prog *prog, u32 *target_size) 955 { 956 struct bpf_insn *insn = insn_buf; 957 958 switch (si->off) { 959 case offsetof(struct bpf_perf_event_data, sample_period): 960 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 961 data), si->dst_reg, si->src_reg, 962 offsetof(struct bpf_perf_event_data_kern, data)); 963 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, 964 bpf_target_off(struct perf_sample_data, period, 8, 965 target_size)); 966 break; 967 case offsetof(struct bpf_perf_event_data, addr): 968 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 969 data), si->dst_reg, si->src_reg, 970 offsetof(struct bpf_perf_event_data_kern, data)); 971 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, 972 bpf_target_off(struct perf_sample_data, addr, 8, 973 target_size)); 974 break; 975 default: 976 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 977 regs), si->dst_reg, si->src_reg, 978 offsetof(struct bpf_perf_event_data_kern, regs)); 979 *insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg, 980 si->off); 981 break; 982 } 983 984 return insn - insn_buf; 985 } 986 987 const struct bpf_verifier_ops perf_event_verifier_ops = { 988 .get_func_proto = pe_prog_func_proto, 989 .is_valid_access = pe_prog_is_valid_access, 990 .convert_ctx_access = pe_prog_convert_ctx_access, 991 }; 992 993 const struct bpf_prog_ops perf_event_prog_ops = { 994 }; 995 996 static DEFINE_MUTEX(bpf_event_mutex); 997 998 #define BPF_TRACE_MAX_PROGS 64 999 1000 int perf_event_attach_bpf_prog(struct perf_event *event, 1001 struct bpf_prog *prog) 1002 { 1003 struct bpf_prog_array __rcu *old_array; 1004 struct bpf_prog_array *new_array; 1005 int ret = -EEXIST; 1006 1007 /* 1008 * Kprobe override only works if they are on the function entry, 1009 * and only if they are on the opt-in list. 1010 */ 1011 if (prog->kprobe_override && 1012 (!trace_kprobe_on_func_entry(event->tp_event) || 1013 !trace_kprobe_error_injectable(event->tp_event))) 1014 return -EINVAL; 1015 1016 mutex_lock(&bpf_event_mutex); 1017 1018 if (event->prog) 1019 goto unlock; 1020 1021 old_array = event->tp_event->prog_array; 1022 if (old_array && 1023 bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) { 1024 ret = -E2BIG; 1025 goto unlock; 1026 } 1027 1028 ret = bpf_prog_array_copy(old_array, NULL, prog, &new_array); 1029 if (ret < 0) 1030 goto unlock; 1031 1032 /* set the new array to event->tp_event and set event->prog */ 1033 event->prog = prog; 1034 rcu_assign_pointer(event->tp_event->prog_array, new_array); 1035 bpf_prog_array_free(old_array); 1036 1037 unlock: 1038 mutex_unlock(&bpf_event_mutex); 1039 return ret; 1040 } 1041 1042 void perf_event_detach_bpf_prog(struct perf_event *event) 1043 { 1044 struct bpf_prog_array __rcu *old_array; 1045 struct bpf_prog_array *new_array; 1046 int ret; 1047 1048 mutex_lock(&bpf_event_mutex); 1049 1050 if (!event->prog) 1051 goto unlock; 1052 1053 old_array = event->tp_event->prog_array; 1054 ret = bpf_prog_array_copy(old_array, event->prog, NULL, &new_array); 1055 if (ret == -ENOENT) 1056 goto unlock; 1057 if (ret < 0) { 1058 bpf_prog_array_delete_safe(old_array, event->prog); 1059 } else { 1060 rcu_assign_pointer(event->tp_event->prog_array, new_array); 1061 bpf_prog_array_free(old_array); 1062 } 1063 1064 bpf_prog_put(event->prog); 1065 event->prog = NULL; 1066 1067 unlock: 1068 mutex_unlock(&bpf_event_mutex); 1069 } 1070 1071 int perf_event_query_prog_array(struct perf_event *event, void __user *info) 1072 { 1073 struct perf_event_query_bpf __user *uquery = info; 1074 struct perf_event_query_bpf query = {}; 1075 u32 *ids, prog_cnt, ids_len; 1076 int ret; 1077 1078 if (!capable(CAP_SYS_ADMIN)) 1079 return -EPERM; 1080 if (event->attr.type != PERF_TYPE_TRACEPOINT) 1081 return -EINVAL; 1082 if (copy_from_user(&query, uquery, sizeof(query))) 1083 return -EFAULT; 1084 1085 ids_len = query.ids_len; 1086 if (ids_len > BPF_TRACE_MAX_PROGS) 1087 return -E2BIG; 1088 ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN); 1089 if (!ids) 1090 return -ENOMEM; 1091 /* 1092 * The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which 1093 * is required when user only wants to check for uquery->prog_cnt. 1094 * There is no need to check for it since the case is handled 1095 * gracefully in bpf_prog_array_copy_info. 1096 */ 1097 1098 mutex_lock(&bpf_event_mutex); 1099 ret = bpf_prog_array_copy_info(event->tp_event->prog_array, 1100 ids, 1101 ids_len, 1102 &prog_cnt); 1103 mutex_unlock(&bpf_event_mutex); 1104 1105 if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) || 1106 copy_to_user(uquery->ids, ids, ids_len * sizeof(u32))) 1107 ret = -EFAULT; 1108 1109 kfree(ids); 1110 return ret; 1111 } 1112 1113 extern struct bpf_raw_event_map __start__bpf_raw_tp[]; 1114 extern struct bpf_raw_event_map __stop__bpf_raw_tp[]; 1115 1116 struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name) 1117 { 1118 struct bpf_raw_event_map *btp = __start__bpf_raw_tp; 1119 1120 for (; btp < __stop__bpf_raw_tp; btp++) { 1121 if (!strcmp(btp->tp->name, name)) 1122 return btp; 1123 } 1124 1125 return bpf_get_raw_tracepoint_module(name); 1126 } 1127 1128 void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp) 1129 { 1130 struct module *mod = __module_address((unsigned long)btp); 1131 1132 if (mod) 1133 module_put(mod); 1134 } 1135 1136 static __always_inline 1137 void __bpf_trace_run(struct bpf_prog *prog, u64 *args) 1138 { 1139 rcu_read_lock(); 1140 preempt_disable(); 1141 (void) BPF_PROG_RUN(prog, args); 1142 preempt_enable(); 1143 rcu_read_unlock(); 1144 } 1145 1146 #define UNPACK(...) __VA_ARGS__ 1147 #define REPEAT_1(FN, DL, X, ...) FN(X) 1148 #define REPEAT_2(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__) 1149 #define REPEAT_3(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_2(FN, DL, __VA_ARGS__) 1150 #define REPEAT_4(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_3(FN, DL, __VA_ARGS__) 1151 #define REPEAT_5(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_4(FN, DL, __VA_ARGS__) 1152 #define REPEAT_6(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_5(FN, DL, __VA_ARGS__) 1153 #define REPEAT_7(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_6(FN, DL, __VA_ARGS__) 1154 #define REPEAT_8(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_7(FN, DL, __VA_ARGS__) 1155 #define REPEAT_9(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_8(FN, DL, __VA_ARGS__) 1156 #define REPEAT_10(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_9(FN, DL, __VA_ARGS__) 1157 #define REPEAT_11(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_10(FN, DL, __VA_ARGS__) 1158 #define REPEAT_12(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_11(FN, DL, __VA_ARGS__) 1159 #define REPEAT(X, FN, DL, ...) REPEAT_##X(FN, DL, __VA_ARGS__) 1160 1161 #define SARG(X) u64 arg##X 1162 #define COPY(X) args[X] = arg##X 1163 1164 #define __DL_COM (,) 1165 #define __DL_SEM (;) 1166 1167 #define __SEQ_0_11 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 1168 1169 #define BPF_TRACE_DEFN_x(x) \ 1170 void bpf_trace_run##x(struct bpf_prog *prog, \ 1171 REPEAT(x, SARG, __DL_COM, __SEQ_0_11)) \ 1172 { \ 1173 u64 args[x]; \ 1174 REPEAT(x, COPY, __DL_SEM, __SEQ_0_11); \ 1175 __bpf_trace_run(prog, args); \ 1176 } \ 1177 EXPORT_SYMBOL_GPL(bpf_trace_run##x) 1178 BPF_TRACE_DEFN_x(1); 1179 BPF_TRACE_DEFN_x(2); 1180 BPF_TRACE_DEFN_x(3); 1181 BPF_TRACE_DEFN_x(4); 1182 BPF_TRACE_DEFN_x(5); 1183 BPF_TRACE_DEFN_x(6); 1184 BPF_TRACE_DEFN_x(7); 1185 BPF_TRACE_DEFN_x(8); 1186 BPF_TRACE_DEFN_x(9); 1187 BPF_TRACE_DEFN_x(10); 1188 BPF_TRACE_DEFN_x(11); 1189 BPF_TRACE_DEFN_x(12); 1190 1191 static int __bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog) 1192 { 1193 struct tracepoint *tp = btp->tp; 1194 1195 /* 1196 * check that program doesn't access arguments beyond what's 1197 * available in this tracepoint 1198 */ 1199 if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64)) 1200 return -EINVAL; 1201 1202 return tracepoint_probe_register(tp, (void *)btp->bpf_func, prog); 1203 } 1204 1205 int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog) 1206 { 1207 int err; 1208 1209 mutex_lock(&bpf_event_mutex); 1210 err = __bpf_probe_register(btp, prog); 1211 mutex_unlock(&bpf_event_mutex); 1212 return err; 1213 } 1214 1215 int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_prog *prog) 1216 { 1217 int err; 1218 1219 mutex_lock(&bpf_event_mutex); 1220 err = tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, prog); 1221 mutex_unlock(&bpf_event_mutex); 1222 return err; 1223 } 1224 1225 int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id, 1226 u32 *fd_type, const char **buf, 1227 u64 *probe_offset, u64 *probe_addr) 1228 { 1229 bool is_tracepoint, is_syscall_tp; 1230 struct bpf_prog *prog; 1231 int flags, err = 0; 1232 1233 prog = event->prog; 1234 if (!prog) 1235 return -ENOENT; 1236 1237 /* not supporting BPF_PROG_TYPE_PERF_EVENT yet */ 1238 if (prog->type == BPF_PROG_TYPE_PERF_EVENT) 1239 return -EOPNOTSUPP; 1240 1241 *prog_id = prog->aux->id; 1242 flags = event->tp_event->flags; 1243 is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT; 1244 is_syscall_tp = is_syscall_trace_event(event->tp_event); 1245 1246 if (is_tracepoint || is_syscall_tp) { 1247 *buf = is_tracepoint ? event->tp_event->tp->name 1248 : event->tp_event->name; 1249 *fd_type = BPF_FD_TYPE_TRACEPOINT; 1250 *probe_offset = 0x0; 1251 *probe_addr = 0x0; 1252 } else { 1253 /* kprobe/uprobe */ 1254 err = -EOPNOTSUPP; 1255 #ifdef CONFIG_KPROBE_EVENTS 1256 if (flags & TRACE_EVENT_FL_KPROBE) 1257 err = bpf_get_kprobe_info(event, fd_type, buf, 1258 probe_offset, probe_addr, 1259 event->attr.type == PERF_TYPE_TRACEPOINT); 1260 #endif 1261 #ifdef CONFIG_UPROBE_EVENTS 1262 if (flags & TRACE_EVENT_FL_UPROBE) 1263 err = bpf_get_uprobe_info(event, fd_type, buf, 1264 probe_offset, 1265 event->attr.type == PERF_TYPE_TRACEPOINT); 1266 #endif 1267 } 1268 1269 return err; 1270 } 1271 1272 #ifdef CONFIG_MODULES 1273 int bpf_event_notify(struct notifier_block *nb, unsigned long op, void *module) 1274 { 1275 struct bpf_trace_module *btm, *tmp; 1276 struct module *mod = module; 1277 1278 if (mod->num_bpf_raw_events == 0 || 1279 (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING)) 1280 return 0; 1281 1282 mutex_lock(&bpf_module_mutex); 1283 1284 switch (op) { 1285 case MODULE_STATE_COMING: 1286 btm = kzalloc(sizeof(*btm), GFP_KERNEL); 1287 if (btm) { 1288 btm->module = module; 1289 list_add(&btm->list, &bpf_trace_modules); 1290 } 1291 break; 1292 case MODULE_STATE_GOING: 1293 list_for_each_entry_safe(btm, tmp, &bpf_trace_modules, list) { 1294 if (btm->module == module) { 1295 list_del(&btm->list); 1296 kfree(btm); 1297 break; 1298 } 1299 } 1300 break; 1301 } 1302 1303 mutex_unlock(&bpf_module_mutex); 1304 1305 return 0; 1306 } 1307 1308 static struct notifier_block bpf_module_nb = { 1309 .notifier_call = bpf_event_notify, 1310 }; 1311 1312 int __init bpf_event_init(void) 1313 { 1314 register_module_notifier(&bpf_module_nb); 1315 return 0; 1316 } 1317 1318 fs_initcall(bpf_event_init); 1319 #endif /* CONFIG_MODULES */ 1320