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/btf.h> 11 #include <linux/filter.h> 12 #include <linux/uaccess.h> 13 #include <linux/ctype.h> 14 #include <linux/kprobes.h> 15 #include <linux/spinlock.h> 16 #include <linux/syscalls.h> 17 #include <linux/error-injection.h> 18 #include <linux/btf_ids.h> 19 #include <linux/bpf_lsm.h> 20 21 #include <net/bpf_sk_storage.h> 22 23 #include <uapi/linux/bpf.h> 24 #include <uapi/linux/btf.h> 25 26 #include <asm/tlb.h> 27 28 #include "trace_probe.h" 29 #include "trace.h" 30 31 #define CREATE_TRACE_POINTS 32 #include "bpf_trace.h" 33 34 #define bpf_event_rcu_dereference(p) \ 35 rcu_dereference_protected(p, lockdep_is_held(&bpf_event_mutex)) 36 37 #ifdef CONFIG_MODULES 38 struct bpf_trace_module { 39 struct module *module; 40 struct list_head list; 41 }; 42 43 static LIST_HEAD(bpf_trace_modules); 44 static DEFINE_MUTEX(bpf_module_mutex); 45 46 static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name) 47 { 48 struct bpf_raw_event_map *btp, *ret = NULL; 49 struct bpf_trace_module *btm; 50 unsigned int i; 51 52 mutex_lock(&bpf_module_mutex); 53 list_for_each_entry(btm, &bpf_trace_modules, list) { 54 for (i = 0; i < btm->module->num_bpf_raw_events; ++i) { 55 btp = &btm->module->bpf_raw_events[i]; 56 if (!strcmp(btp->tp->name, name)) { 57 if (try_module_get(btm->module)) 58 ret = btp; 59 goto out; 60 } 61 } 62 } 63 out: 64 mutex_unlock(&bpf_module_mutex); 65 return ret; 66 } 67 #else 68 static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name) 69 { 70 return NULL; 71 } 72 #endif /* CONFIG_MODULES */ 73 74 u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); 75 u64 bpf_get_stack(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); 76 77 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size, 78 u64 flags, const struct btf **btf, 79 s32 *btf_id); 80 81 /** 82 * trace_call_bpf - invoke BPF program 83 * @call: tracepoint event 84 * @ctx: opaque context pointer 85 * 86 * kprobe handlers execute BPF programs via this helper. 87 * Can be used from static tracepoints in the future. 88 * 89 * Return: BPF programs always return an integer which is interpreted by 90 * kprobe handler as: 91 * 0 - return from kprobe (event is filtered out) 92 * 1 - store kprobe event into ring buffer 93 * Other values are reserved and currently alias to 1 94 */ 95 unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx) 96 { 97 unsigned int ret; 98 99 cant_sleep(); 100 101 if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) { 102 /* 103 * since some bpf program is already running on this cpu, 104 * don't call into another bpf program (same or different) 105 * and don't send kprobe event into ring-buffer, 106 * so return zero here 107 */ 108 ret = 0; 109 goto out; 110 } 111 112 /* 113 * Instead of moving rcu_read_lock/rcu_dereference/rcu_read_unlock 114 * to all call sites, we did a bpf_prog_array_valid() there to check 115 * whether call->prog_array is empty or not, which is 116 * a heuristic to speed up execution. 117 * 118 * If bpf_prog_array_valid() fetched prog_array was 119 * non-NULL, we go into trace_call_bpf() and do the actual 120 * proper rcu_dereference() under RCU lock. 121 * If it turns out that prog_array is NULL then, we bail out. 122 * For the opposite, if the bpf_prog_array_valid() fetched pointer 123 * was NULL, you'll skip the prog_array with the risk of missing 124 * out of events when it was updated in between this and the 125 * rcu_dereference() which is accepted risk. 126 */ 127 ret = BPF_PROG_RUN_ARRAY(call->prog_array, ctx, bpf_prog_run); 128 129 out: 130 __this_cpu_dec(bpf_prog_active); 131 132 return ret; 133 } 134 135 #ifdef CONFIG_BPF_KPROBE_OVERRIDE 136 BPF_CALL_2(bpf_override_return, struct pt_regs *, regs, unsigned long, rc) 137 { 138 regs_set_return_value(regs, rc); 139 override_function_with_return(regs); 140 return 0; 141 } 142 143 static const struct bpf_func_proto bpf_override_return_proto = { 144 .func = bpf_override_return, 145 .gpl_only = true, 146 .ret_type = RET_INTEGER, 147 .arg1_type = ARG_PTR_TO_CTX, 148 .arg2_type = ARG_ANYTHING, 149 }; 150 #endif 151 152 static __always_inline int 153 bpf_probe_read_user_common(void *dst, u32 size, const void __user *unsafe_ptr) 154 { 155 int ret; 156 157 ret = copy_from_user_nofault(dst, unsafe_ptr, size); 158 if (unlikely(ret < 0)) 159 memset(dst, 0, size); 160 return ret; 161 } 162 163 BPF_CALL_3(bpf_probe_read_user, void *, dst, u32, size, 164 const void __user *, unsafe_ptr) 165 { 166 return bpf_probe_read_user_common(dst, size, unsafe_ptr); 167 } 168 169 const struct bpf_func_proto bpf_probe_read_user_proto = { 170 .func = bpf_probe_read_user, 171 .gpl_only = true, 172 .ret_type = RET_INTEGER, 173 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 174 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 175 .arg3_type = ARG_ANYTHING, 176 }; 177 178 static __always_inline int 179 bpf_probe_read_user_str_common(void *dst, u32 size, 180 const void __user *unsafe_ptr) 181 { 182 int ret; 183 184 /* 185 * NB: We rely on strncpy_from_user() not copying junk past the NUL 186 * terminator into `dst`. 187 * 188 * strncpy_from_user() does long-sized strides in the fast path. If the 189 * strncpy does not mask out the bytes after the NUL in `unsafe_ptr`, 190 * then there could be junk after the NUL in `dst`. If user takes `dst` 191 * and keys a hash map with it, then semantically identical strings can 192 * occupy multiple entries in the map. 193 */ 194 ret = strncpy_from_user_nofault(dst, unsafe_ptr, size); 195 if (unlikely(ret < 0)) 196 memset(dst, 0, size); 197 return ret; 198 } 199 200 BPF_CALL_3(bpf_probe_read_user_str, void *, dst, u32, size, 201 const void __user *, unsafe_ptr) 202 { 203 return bpf_probe_read_user_str_common(dst, size, unsafe_ptr); 204 } 205 206 const struct bpf_func_proto bpf_probe_read_user_str_proto = { 207 .func = bpf_probe_read_user_str, 208 .gpl_only = true, 209 .ret_type = RET_INTEGER, 210 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 211 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 212 .arg3_type = ARG_ANYTHING, 213 }; 214 215 static __always_inline int 216 bpf_probe_read_kernel_common(void *dst, u32 size, const void *unsafe_ptr) 217 { 218 int ret; 219 220 ret = copy_from_kernel_nofault(dst, unsafe_ptr, size); 221 if (unlikely(ret < 0)) 222 memset(dst, 0, size); 223 return ret; 224 } 225 226 BPF_CALL_3(bpf_probe_read_kernel, void *, dst, u32, size, 227 const void *, unsafe_ptr) 228 { 229 return bpf_probe_read_kernel_common(dst, size, unsafe_ptr); 230 } 231 232 const struct bpf_func_proto bpf_probe_read_kernel_proto = { 233 .func = bpf_probe_read_kernel, 234 .gpl_only = true, 235 .ret_type = RET_INTEGER, 236 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 237 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 238 .arg3_type = ARG_ANYTHING, 239 }; 240 241 static __always_inline int 242 bpf_probe_read_kernel_str_common(void *dst, u32 size, const void *unsafe_ptr) 243 { 244 int ret; 245 246 /* 247 * The strncpy_from_kernel_nofault() call will likely not fill the 248 * entire buffer, but that's okay in this circumstance as we're probing 249 * arbitrary memory anyway similar to bpf_probe_read_*() and might 250 * as well probe the stack. Thus, memory is explicitly cleared 251 * only in error case, so that improper users ignoring return 252 * code altogether don't copy garbage; otherwise length of string 253 * is returned that can be used for bpf_perf_event_output() et al. 254 */ 255 ret = strncpy_from_kernel_nofault(dst, unsafe_ptr, size); 256 if (unlikely(ret < 0)) 257 memset(dst, 0, size); 258 return ret; 259 } 260 261 BPF_CALL_3(bpf_probe_read_kernel_str, void *, dst, u32, size, 262 const void *, unsafe_ptr) 263 { 264 return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr); 265 } 266 267 const struct bpf_func_proto bpf_probe_read_kernel_str_proto = { 268 .func = bpf_probe_read_kernel_str, 269 .gpl_only = true, 270 .ret_type = RET_INTEGER, 271 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 272 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 273 .arg3_type = ARG_ANYTHING, 274 }; 275 276 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 277 BPF_CALL_3(bpf_probe_read_compat, void *, dst, u32, size, 278 const void *, unsafe_ptr) 279 { 280 if ((unsigned long)unsafe_ptr < TASK_SIZE) { 281 return bpf_probe_read_user_common(dst, size, 282 (__force void __user *)unsafe_ptr); 283 } 284 return bpf_probe_read_kernel_common(dst, size, unsafe_ptr); 285 } 286 287 static const struct bpf_func_proto bpf_probe_read_compat_proto = { 288 .func = bpf_probe_read_compat, 289 .gpl_only = true, 290 .ret_type = RET_INTEGER, 291 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 292 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 293 .arg3_type = ARG_ANYTHING, 294 }; 295 296 BPF_CALL_3(bpf_probe_read_compat_str, void *, dst, u32, size, 297 const void *, unsafe_ptr) 298 { 299 if ((unsigned long)unsafe_ptr < TASK_SIZE) { 300 return bpf_probe_read_user_str_common(dst, size, 301 (__force void __user *)unsafe_ptr); 302 } 303 return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr); 304 } 305 306 static const struct bpf_func_proto bpf_probe_read_compat_str_proto = { 307 .func = bpf_probe_read_compat_str, 308 .gpl_only = true, 309 .ret_type = RET_INTEGER, 310 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 311 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 312 .arg3_type = ARG_ANYTHING, 313 }; 314 #endif /* CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE */ 315 316 BPF_CALL_3(bpf_probe_write_user, void __user *, unsafe_ptr, const void *, src, 317 u32, size) 318 { 319 /* 320 * Ensure we're in user context which is safe for the helper to 321 * run. This helper has no business in a kthread. 322 * 323 * access_ok() should prevent writing to non-user memory, but in 324 * some situations (nommu, temporary switch, etc) access_ok() does 325 * not provide enough validation, hence the check on KERNEL_DS. 326 * 327 * nmi_uaccess_okay() ensures the probe is not run in an interim 328 * state, when the task or mm are switched. This is specifically 329 * required to prevent the use of temporary mm. 330 */ 331 332 if (unlikely(in_interrupt() || 333 current->flags & (PF_KTHREAD | PF_EXITING))) 334 return -EPERM; 335 if (unlikely(uaccess_kernel())) 336 return -EPERM; 337 if (unlikely(!nmi_uaccess_okay())) 338 return -EPERM; 339 340 return copy_to_user_nofault(unsafe_ptr, src, size); 341 } 342 343 static const struct bpf_func_proto bpf_probe_write_user_proto = { 344 .func = bpf_probe_write_user, 345 .gpl_only = true, 346 .ret_type = RET_INTEGER, 347 .arg1_type = ARG_ANYTHING, 348 .arg2_type = ARG_PTR_TO_MEM, 349 .arg3_type = ARG_CONST_SIZE, 350 }; 351 352 static const struct bpf_func_proto *bpf_get_probe_write_proto(void) 353 { 354 if (!capable(CAP_SYS_ADMIN)) 355 return NULL; 356 357 pr_warn_ratelimited("%s[%d] is installing a program with bpf_probe_write_user helper that may corrupt user memory!", 358 current->comm, task_pid_nr(current)); 359 360 return &bpf_probe_write_user_proto; 361 } 362 363 static DEFINE_RAW_SPINLOCK(trace_printk_lock); 364 365 #define MAX_TRACE_PRINTK_VARARGS 3 366 #define BPF_TRACE_PRINTK_SIZE 1024 367 368 BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1, 369 u64, arg2, u64, arg3) 370 { 371 u64 args[MAX_TRACE_PRINTK_VARARGS] = { arg1, arg2, arg3 }; 372 u32 *bin_args; 373 static char buf[BPF_TRACE_PRINTK_SIZE]; 374 unsigned long flags; 375 int ret; 376 377 ret = bpf_bprintf_prepare(fmt, fmt_size, args, &bin_args, 378 MAX_TRACE_PRINTK_VARARGS); 379 if (ret < 0) 380 return ret; 381 382 raw_spin_lock_irqsave(&trace_printk_lock, flags); 383 ret = bstr_printf(buf, sizeof(buf), fmt, bin_args); 384 385 trace_bpf_trace_printk(buf); 386 raw_spin_unlock_irqrestore(&trace_printk_lock, flags); 387 388 bpf_bprintf_cleanup(); 389 390 return ret; 391 } 392 393 static const struct bpf_func_proto bpf_trace_printk_proto = { 394 .func = bpf_trace_printk, 395 .gpl_only = true, 396 .ret_type = RET_INTEGER, 397 .arg1_type = ARG_PTR_TO_MEM, 398 .arg2_type = ARG_CONST_SIZE, 399 }; 400 401 static void __set_printk_clr_event(void) 402 { 403 /* 404 * This program might be calling bpf_trace_printk, 405 * so enable the associated bpf_trace/bpf_trace_printk event. 406 * Repeat this each time as it is possible a user has 407 * disabled bpf_trace_printk events. By loading a program 408 * calling bpf_trace_printk() however the user has expressed 409 * the intent to see such events. 410 */ 411 if (trace_set_clr_event("bpf_trace", "bpf_trace_printk", 1)) 412 pr_warn_ratelimited("could not enable bpf_trace_printk events"); 413 } 414 415 const struct bpf_func_proto *bpf_get_trace_printk_proto(void) 416 { 417 __set_printk_clr_event(); 418 return &bpf_trace_printk_proto; 419 } 420 421 BPF_CALL_4(bpf_trace_vprintk, char *, fmt, u32, fmt_size, const void *, data, 422 u32, data_len) 423 { 424 static char buf[BPF_TRACE_PRINTK_SIZE]; 425 unsigned long flags; 426 int ret, num_args; 427 u32 *bin_args; 428 429 if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 || 430 (data_len && !data)) 431 return -EINVAL; 432 num_args = data_len / 8; 433 434 ret = bpf_bprintf_prepare(fmt, fmt_size, data, &bin_args, num_args); 435 if (ret < 0) 436 return ret; 437 438 raw_spin_lock_irqsave(&trace_printk_lock, flags); 439 ret = bstr_printf(buf, sizeof(buf), fmt, bin_args); 440 441 trace_bpf_trace_printk(buf); 442 raw_spin_unlock_irqrestore(&trace_printk_lock, flags); 443 444 bpf_bprintf_cleanup(); 445 446 return ret; 447 } 448 449 static const struct bpf_func_proto bpf_trace_vprintk_proto = { 450 .func = bpf_trace_vprintk, 451 .gpl_only = true, 452 .ret_type = RET_INTEGER, 453 .arg1_type = ARG_PTR_TO_MEM, 454 .arg2_type = ARG_CONST_SIZE, 455 .arg3_type = ARG_PTR_TO_MEM_OR_NULL, 456 .arg4_type = ARG_CONST_SIZE_OR_ZERO, 457 }; 458 459 const struct bpf_func_proto *bpf_get_trace_vprintk_proto(void) 460 { 461 __set_printk_clr_event(); 462 return &bpf_trace_vprintk_proto; 463 } 464 465 BPF_CALL_5(bpf_seq_printf, struct seq_file *, m, char *, fmt, u32, fmt_size, 466 const void *, data, u32, data_len) 467 { 468 int err, num_args; 469 u32 *bin_args; 470 471 if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 || 472 (data_len && !data)) 473 return -EINVAL; 474 num_args = data_len / 8; 475 476 err = bpf_bprintf_prepare(fmt, fmt_size, data, &bin_args, num_args); 477 if (err < 0) 478 return err; 479 480 seq_bprintf(m, fmt, bin_args); 481 482 bpf_bprintf_cleanup(); 483 484 return seq_has_overflowed(m) ? -EOVERFLOW : 0; 485 } 486 487 BTF_ID_LIST_SINGLE(btf_seq_file_ids, struct, seq_file) 488 489 static const struct bpf_func_proto bpf_seq_printf_proto = { 490 .func = bpf_seq_printf, 491 .gpl_only = true, 492 .ret_type = RET_INTEGER, 493 .arg1_type = ARG_PTR_TO_BTF_ID, 494 .arg1_btf_id = &btf_seq_file_ids[0], 495 .arg2_type = ARG_PTR_TO_MEM, 496 .arg3_type = ARG_CONST_SIZE, 497 .arg4_type = ARG_PTR_TO_MEM_OR_NULL, 498 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 499 }; 500 501 BPF_CALL_3(bpf_seq_write, struct seq_file *, m, const void *, data, u32, len) 502 { 503 return seq_write(m, data, len) ? -EOVERFLOW : 0; 504 } 505 506 static const struct bpf_func_proto bpf_seq_write_proto = { 507 .func = bpf_seq_write, 508 .gpl_only = true, 509 .ret_type = RET_INTEGER, 510 .arg1_type = ARG_PTR_TO_BTF_ID, 511 .arg1_btf_id = &btf_seq_file_ids[0], 512 .arg2_type = ARG_PTR_TO_MEM, 513 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 514 }; 515 516 BPF_CALL_4(bpf_seq_printf_btf, struct seq_file *, m, struct btf_ptr *, ptr, 517 u32, btf_ptr_size, u64, flags) 518 { 519 const struct btf *btf; 520 s32 btf_id; 521 int ret; 522 523 ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id); 524 if (ret) 525 return ret; 526 527 return btf_type_seq_show_flags(btf, btf_id, ptr->ptr, m, flags); 528 } 529 530 static const struct bpf_func_proto bpf_seq_printf_btf_proto = { 531 .func = bpf_seq_printf_btf, 532 .gpl_only = true, 533 .ret_type = RET_INTEGER, 534 .arg1_type = ARG_PTR_TO_BTF_ID, 535 .arg1_btf_id = &btf_seq_file_ids[0], 536 .arg2_type = ARG_PTR_TO_MEM, 537 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 538 .arg4_type = ARG_ANYTHING, 539 }; 540 541 static __always_inline int 542 get_map_perf_counter(struct bpf_map *map, u64 flags, 543 u64 *value, u64 *enabled, u64 *running) 544 { 545 struct bpf_array *array = container_of(map, struct bpf_array, map); 546 unsigned int cpu = smp_processor_id(); 547 u64 index = flags & BPF_F_INDEX_MASK; 548 struct bpf_event_entry *ee; 549 550 if (unlikely(flags & ~(BPF_F_INDEX_MASK))) 551 return -EINVAL; 552 if (index == BPF_F_CURRENT_CPU) 553 index = cpu; 554 if (unlikely(index >= array->map.max_entries)) 555 return -E2BIG; 556 557 ee = READ_ONCE(array->ptrs[index]); 558 if (!ee) 559 return -ENOENT; 560 561 return perf_event_read_local(ee->event, value, enabled, running); 562 } 563 564 BPF_CALL_2(bpf_perf_event_read, struct bpf_map *, map, u64, flags) 565 { 566 u64 value = 0; 567 int err; 568 569 err = get_map_perf_counter(map, flags, &value, NULL, NULL); 570 /* 571 * this api is ugly since we miss [-22..-2] range of valid 572 * counter values, but that's uapi 573 */ 574 if (err) 575 return err; 576 return value; 577 } 578 579 static const struct bpf_func_proto bpf_perf_event_read_proto = { 580 .func = bpf_perf_event_read, 581 .gpl_only = true, 582 .ret_type = RET_INTEGER, 583 .arg1_type = ARG_CONST_MAP_PTR, 584 .arg2_type = ARG_ANYTHING, 585 }; 586 587 BPF_CALL_4(bpf_perf_event_read_value, struct bpf_map *, map, u64, flags, 588 struct bpf_perf_event_value *, buf, u32, size) 589 { 590 int err = -EINVAL; 591 592 if (unlikely(size != sizeof(struct bpf_perf_event_value))) 593 goto clear; 594 err = get_map_perf_counter(map, flags, &buf->counter, &buf->enabled, 595 &buf->running); 596 if (unlikely(err)) 597 goto clear; 598 return 0; 599 clear: 600 memset(buf, 0, size); 601 return err; 602 } 603 604 static const struct bpf_func_proto bpf_perf_event_read_value_proto = { 605 .func = bpf_perf_event_read_value, 606 .gpl_only = true, 607 .ret_type = RET_INTEGER, 608 .arg1_type = ARG_CONST_MAP_PTR, 609 .arg2_type = ARG_ANYTHING, 610 .arg3_type = ARG_PTR_TO_UNINIT_MEM, 611 .arg4_type = ARG_CONST_SIZE, 612 }; 613 614 static __always_inline u64 615 __bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map, 616 u64 flags, struct perf_sample_data *sd) 617 { 618 struct bpf_array *array = container_of(map, struct bpf_array, map); 619 unsigned int cpu = smp_processor_id(); 620 u64 index = flags & BPF_F_INDEX_MASK; 621 struct bpf_event_entry *ee; 622 struct perf_event *event; 623 624 if (index == BPF_F_CURRENT_CPU) 625 index = cpu; 626 if (unlikely(index >= array->map.max_entries)) 627 return -E2BIG; 628 629 ee = READ_ONCE(array->ptrs[index]); 630 if (!ee) 631 return -ENOENT; 632 633 event = ee->event; 634 if (unlikely(event->attr.type != PERF_TYPE_SOFTWARE || 635 event->attr.config != PERF_COUNT_SW_BPF_OUTPUT)) 636 return -EINVAL; 637 638 if (unlikely(event->oncpu != cpu)) 639 return -EOPNOTSUPP; 640 641 return perf_event_output(event, sd, regs); 642 } 643 644 /* 645 * Support executing tracepoints in normal, irq, and nmi context that each call 646 * bpf_perf_event_output 647 */ 648 struct bpf_trace_sample_data { 649 struct perf_sample_data sds[3]; 650 }; 651 652 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_trace_sds); 653 static DEFINE_PER_CPU(int, bpf_trace_nest_level); 654 BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map, 655 u64, flags, void *, data, u64, size) 656 { 657 struct bpf_trace_sample_data *sds = this_cpu_ptr(&bpf_trace_sds); 658 int nest_level = this_cpu_inc_return(bpf_trace_nest_level); 659 struct perf_raw_record raw = { 660 .frag = { 661 .size = size, 662 .data = data, 663 }, 664 }; 665 struct perf_sample_data *sd; 666 int err; 667 668 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(sds->sds))) { 669 err = -EBUSY; 670 goto out; 671 } 672 673 sd = &sds->sds[nest_level - 1]; 674 675 if (unlikely(flags & ~(BPF_F_INDEX_MASK))) { 676 err = -EINVAL; 677 goto out; 678 } 679 680 perf_sample_data_init(sd, 0, 0); 681 sd->raw = &raw; 682 683 err = __bpf_perf_event_output(regs, map, flags, sd); 684 685 out: 686 this_cpu_dec(bpf_trace_nest_level); 687 return err; 688 } 689 690 static const struct bpf_func_proto bpf_perf_event_output_proto = { 691 .func = bpf_perf_event_output, 692 .gpl_only = true, 693 .ret_type = RET_INTEGER, 694 .arg1_type = ARG_PTR_TO_CTX, 695 .arg2_type = ARG_CONST_MAP_PTR, 696 .arg3_type = ARG_ANYTHING, 697 .arg4_type = ARG_PTR_TO_MEM, 698 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 699 }; 700 701 static DEFINE_PER_CPU(int, bpf_event_output_nest_level); 702 struct bpf_nested_pt_regs { 703 struct pt_regs regs[3]; 704 }; 705 static DEFINE_PER_CPU(struct bpf_nested_pt_regs, bpf_pt_regs); 706 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_misc_sds); 707 708 u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size, 709 void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy) 710 { 711 int nest_level = this_cpu_inc_return(bpf_event_output_nest_level); 712 struct perf_raw_frag frag = { 713 .copy = ctx_copy, 714 .size = ctx_size, 715 .data = ctx, 716 }; 717 struct perf_raw_record raw = { 718 .frag = { 719 { 720 .next = ctx_size ? &frag : NULL, 721 }, 722 .size = meta_size, 723 .data = meta, 724 }, 725 }; 726 struct perf_sample_data *sd; 727 struct pt_regs *regs; 728 u64 ret; 729 730 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(bpf_misc_sds.sds))) { 731 ret = -EBUSY; 732 goto out; 733 } 734 sd = this_cpu_ptr(&bpf_misc_sds.sds[nest_level - 1]); 735 regs = this_cpu_ptr(&bpf_pt_regs.regs[nest_level - 1]); 736 737 perf_fetch_caller_regs(regs); 738 perf_sample_data_init(sd, 0, 0); 739 sd->raw = &raw; 740 741 ret = __bpf_perf_event_output(regs, map, flags, sd); 742 out: 743 this_cpu_dec(bpf_event_output_nest_level); 744 return ret; 745 } 746 747 BPF_CALL_0(bpf_get_current_task) 748 { 749 return (long) current; 750 } 751 752 const struct bpf_func_proto bpf_get_current_task_proto = { 753 .func = bpf_get_current_task, 754 .gpl_only = true, 755 .ret_type = RET_INTEGER, 756 }; 757 758 BPF_CALL_0(bpf_get_current_task_btf) 759 { 760 return (unsigned long) current; 761 } 762 763 const struct bpf_func_proto bpf_get_current_task_btf_proto = { 764 .func = bpf_get_current_task_btf, 765 .gpl_only = true, 766 .ret_type = RET_PTR_TO_BTF_ID, 767 .ret_btf_id = &btf_task_struct_ids[0], 768 }; 769 770 BPF_CALL_1(bpf_task_pt_regs, struct task_struct *, task) 771 { 772 return (unsigned long) task_pt_regs(task); 773 } 774 775 BTF_ID_LIST(bpf_task_pt_regs_ids) 776 BTF_ID(struct, pt_regs) 777 778 const struct bpf_func_proto bpf_task_pt_regs_proto = { 779 .func = bpf_task_pt_regs, 780 .gpl_only = true, 781 .arg1_type = ARG_PTR_TO_BTF_ID, 782 .arg1_btf_id = &btf_task_struct_ids[0], 783 .ret_type = RET_PTR_TO_BTF_ID, 784 .ret_btf_id = &bpf_task_pt_regs_ids[0], 785 }; 786 787 BPF_CALL_2(bpf_current_task_under_cgroup, struct bpf_map *, map, u32, idx) 788 { 789 struct bpf_array *array = container_of(map, struct bpf_array, map); 790 struct cgroup *cgrp; 791 792 if (unlikely(idx >= array->map.max_entries)) 793 return -E2BIG; 794 795 cgrp = READ_ONCE(array->ptrs[idx]); 796 if (unlikely(!cgrp)) 797 return -EAGAIN; 798 799 return task_under_cgroup_hierarchy(current, cgrp); 800 } 801 802 static const struct bpf_func_proto bpf_current_task_under_cgroup_proto = { 803 .func = bpf_current_task_under_cgroup, 804 .gpl_only = false, 805 .ret_type = RET_INTEGER, 806 .arg1_type = ARG_CONST_MAP_PTR, 807 .arg2_type = ARG_ANYTHING, 808 }; 809 810 struct send_signal_irq_work { 811 struct irq_work irq_work; 812 struct task_struct *task; 813 u32 sig; 814 enum pid_type type; 815 }; 816 817 static DEFINE_PER_CPU(struct send_signal_irq_work, send_signal_work); 818 819 static void do_bpf_send_signal(struct irq_work *entry) 820 { 821 struct send_signal_irq_work *work; 822 823 work = container_of(entry, struct send_signal_irq_work, irq_work); 824 group_send_sig_info(work->sig, SEND_SIG_PRIV, work->task, work->type); 825 } 826 827 static int bpf_send_signal_common(u32 sig, enum pid_type type) 828 { 829 struct send_signal_irq_work *work = NULL; 830 831 /* Similar to bpf_probe_write_user, task needs to be 832 * in a sound condition and kernel memory access be 833 * permitted in order to send signal to the current 834 * task. 835 */ 836 if (unlikely(current->flags & (PF_KTHREAD | PF_EXITING))) 837 return -EPERM; 838 if (unlikely(uaccess_kernel())) 839 return -EPERM; 840 if (unlikely(!nmi_uaccess_okay())) 841 return -EPERM; 842 843 if (irqs_disabled()) { 844 /* Do an early check on signal validity. Otherwise, 845 * the error is lost in deferred irq_work. 846 */ 847 if (unlikely(!valid_signal(sig))) 848 return -EINVAL; 849 850 work = this_cpu_ptr(&send_signal_work); 851 if (irq_work_is_busy(&work->irq_work)) 852 return -EBUSY; 853 854 /* Add the current task, which is the target of sending signal, 855 * to the irq_work. The current task may change when queued 856 * irq works get executed. 857 */ 858 work->task = current; 859 work->sig = sig; 860 work->type = type; 861 irq_work_queue(&work->irq_work); 862 return 0; 863 } 864 865 return group_send_sig_info(sig, SEND_SIG_PRIV, current, type); 866 } 867 868 BPF_CALL_1(bpf_send_signal, u32, sig) 869 { 870 return bpf_send_signal_common(sig, PIDTYPE_TGID); 871 } 872 873 static const struct bpf_func_proto bpf_send_signal_proto = { 874 .func = bpf_send_signal, 875 .gpl_only = false, 876 .ret_type = RET_INTEGER, 877 .arg1_type = ARG_ANYTHING, 878 }; 879 880 BPF_CALL_1(bpf_send_signal_thread, u32, sig) 881 { 882 return bpf_send_signal_common(sig, PIDTYPE_PID); 883 } 884 885 static const struct bpf_func_proto bpf_send_signal_thread_proto = { 886 .func = bpf_send_signal_thread, 887 .gpl_only = false, 888 .ret_type = RET_INTEGER, 889 .arg1_type = ARG_ANYTHING, 890 }; 891 892 BPF_CALL_3(bpf_d_path, struct path *, path, char *, buf, u32, sz) 893 { 894 long len; 895 char *p; 896 897 if (!sz) 898 return 0; 899 900 p = d_path(path, buf, sz); 901 if (IS_ERR(p)) { 902 len = PTR_ERR(p); 903 } else { 904 len = buf + sz - p; 905 memmove(buf, p, len); 906 } 907 908 return len; 909 } 910 911 BTF_SET_START(btf_allowlist_d_path) 912 #ifdef CONFIG_SECURITY 913 BTF_ID(func, security_file_permission) 914 BTF_ID(func, security_inode_getattr) 915 BTF_ID(func, security_file_open) 916 #endif 917 #ifdef CONFIG_SECURITY_PATH 918 BTF_ID(func, security_path_truncate) 919 #endif 920 BTF_ID(func, vfs_truncate) 921 BTF_ID(func, vfs_fallocate) 922 BTF_ID(func, dentry_open) 923 BTF_ID(func, vfs_getattr) 924 BTF_ID(func, filp_close) 925 BTF_SET_END(btf_allowlist_d_path) 926 927 static bool bpf_d_path_allowed(const struct bpf_prog *prog) 928 { 929 if (prog->type == BPF_PROG_TYPE_TRACING && 930 prog->expected_attach_type == BPF_TRACE_ITER) 931 return true; 932 933 if (prog->type == BPF_PROG_TYPE_LSM) 934 return bpf_lsm_is_sleepable_hook(prog->aux->attach_btf_id); 935 936 return btf_id_set_contains(&btf_allowlist_d_path, 937 prog->aux->attach_btf_id); 938 } 939 940 BTF_ID_LIST_SINGLE(bpf_d_path_btf_ids, struct, path) 941 942 static const struct bpf_func_proto bpf_d_path_proto = { 943 .func = bpf_d_path, 944 .gpl_only = false, 945 .ret_type = RET_INTEGER, 946 .arg1_type = ARG_PTR_TO_BTF_ID, 947 .arg1_btf_id = &bpf_d_path_btf_ids[0], 948 .arg2_type = ARG_PTR_TO_MEM, 949 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 950 .allowed = bpf_d_path_allowed, 951 }; 952 953 #define BTF_F_ALL (BTF_F_COMPACT | BTF_F_NONAME | \ 954 BTF_F_PTR_RAW | BTF_F_ZERO) 955 956 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size, 957 u64 flags, const struct btf **btf, 958 s32 *btf_id) 959 { 960 const struct btf_type *t; 961 962 if (unlikely(flags & ~(BTF_F_ALL))) 963 return -EINVAL; 964 965 if (btf_ptr_size != sizeof(struct btf_ptr)) 966 return -EINVAL; 967 968 *btf = bpf_get_btf_vmlinux(); 969 970 if (IS_ERR_OR_NULL(*btf)) 971 return IS_ERR(*btf) ? PTR_ERR(*btf) : -EINVAL; 972 973 if (ptr->type_id > 0) 974 *btf_id = ptr->type_id; 975 else 976 return -EINVAL; 977 978 if (*btf_id > 0) 979 t = btf_type_by_id(*btf, *btf_id); 980 if (*btf_id <= 0 || !t) 981 return -ENOENT; 982 983 return 0; 984 } 985 986 BPF_CALL_5(bpf_snprintf_btf, char *, str, u32, str_size, struct btf_ptr *, ptr, 987 u32, btf_ptr_size, u64, flags) 988 { 989 const struct btf *btf; 990 s32 btf_id; 991 int ret; 992 993 ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id); 994 if (ret) 995 return ret; 996 997 return btf_type_snprintf_show(btf, btf_id, ptr->ptr, str, str_size, 998 flags); 999 } 1000 1001 const struct bpf_func_proto bpf_snprintf_btf_proto = { 1002 .func = bpf_snprintf_btf, 1003 .gpl_only = false, 1004 .ret_type = RET_INTEGER, 1005 .arg1_type = ARG_PTR_TO_MEM, 1006 .arg2_type = ARG_CONST_SIZE, 1007 .arg3_type = ARG_PTR_TO_MEM, 1008 .arg4_type = ARG_CONST_SIZE, 1009 .arg5_type = ARG_ANYTHING, 1010 }; 1011 1012 BPF_CALL_1(bpf_get_func_ip_tracing, void *, ctx) 1013 { 1014 /* This helper call is inlined by verifier. */ 1015 return ((u64 *)ctx)[-1]; 1016 } 1017 1018 static const struct bpf_func_proto bpf_get_func_ip_proto_tracing = { 1019 .func = bpf_get_func_ip_tracing, 1020 .gpl_only = true, 1021 .ret_type = RET_INTEGER, 1022 .arg1_type = ARG_PTR_TO_CTX, 1023 }; 1024 1025 BPF_CALL_1(bpf_get_func_ip_kprobe, struct pt_regs *, regs) 1026 { 1027 struct kprobe *kp = kprobe_running(); 1028 1029 return kp ? (uintptr_t)kp->addr : 0; 1030 } 1031 1032 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe = { 1033 .func = bpf_get_func_ip_kprobe, 1034 .gpl_only = true, 1035 .ret_type = RET_INTEGER, 1036 .arg1_type = ARG_PTR_TO_CTX, 1037 }; 1038 1039 BPF_CALL_1(bpf_get_attach_cookie_trace, void *, ctx) 1040 { 1041 struct bpf_trace_run_ctx *run_ctx; 1042 1043 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); 1044 return run_ctx->bpf_cookie; 1045 } 1046 1047 static const struct bpf_func_proto bpf_get_attach_cookie_proto_trace = { 1048 .func = bpf_get_attach_cookie_trace, 1049 .gpl_only = false, 1050 .ret_type = RET_INTEGER, 1051 .arg1_type = ARG_PTR_TO_CTX, 1052 }; 1053 1054 BPF_CALL_1(bpf_get_attach_cookie_pe, struct bpf_perf_event_data_kern *, ctx) 1055 { 1056 return ctx->event->bpf_cookie; 1057 } 1058 1059 static const struct bpf_func_proto bpf_get_attach_cookie_proto_pe = { 1060 .func = bpf_get_attach_cookie_pe, 1061 .gpl_only = false, 1062 .ret_type = RET_INTEGER, 1063 .arg1_type = ARG_PTR_TO_CTX, 1064 }; 1065 1066 BPF_CALL_3(bpf_get_branch_snapshot, void *, buf, u32, size, u64, flags) 1067 { 1068 #ifndef CONFIG_X86 1069 return -ENOENT; 1070 #else 1071 static const u32 br_entry_size = sizeof(struct perf_branch_entry); 1072 u32 entry_cnt = size / br_entry_size; 1073 1074 entry_cnt = static_call(perf_snapshot_branch_stack)(buf, entry_cnt); 1075 1076 if (unlikely(flags)) 1077 return -EINVAL; 1078 1079 if (!entry_cnt) 1080 return -ENOENT; 1081 1082 return entry_cnt * br_entry_size; 1083 #endif 1084 } 1085 1086 static const struct bpf_func_proto bpf_get_branch_snapshot_proto = { 1087 .func = bpf_get_branch_snapshot, 1088 .gpl_only = true, 1089 .ret_type = RET_INTEGER, 1090 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 1091 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 1092 }; 1093 1094 static const struct bpf_func_proto * 1095 bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1096 { 1097 switch (func_id) { 1098 case BPF_FUNC_map_lookup_elem: 1099 return &bpf_map_lookup_elem_proto; 1100 case BPF_FUNC_map_update_elem: 1101 return &bpf_map_update_elem_proto; 1102 case BPF_FUNC_map_delete_elem: 1103 return &bpf_map_delete_elem_proto; 1104 case BPF_FUNC_map_push_elem: 1105 return &bpf_map_push_elem_proto; 1106 case BPF_FUNC_map_pop_elem: 1107 return &bpf_map_pop_elem_proto; 1108 case BPF_FUNC_map_peek_elem: 1109 return &bpf_map_peek_elem_proto; 1110 case BPF_FUNC_ktime_get_ns: 1111 return &bpf_ktime_get_ns_proto; 1112 case BPF_FUNC_ktime_get_boot_ns: 1113 return &bpf_ktime_get_boot_ns_proto; 1114 case BPF_FUNC_ktime_get_coarse_ns: 1115 return &bpf_ktime_get_coarse_ns_proto; 1116 case BPF_FUNC_tail_call: 1117 return &bpf_tail_call_proto; 1118 case BPF_FUNC_get_current_pid_tgid: 1119 return &bpf_get_current_pid_tgid_proto; 1120 case BPF_FUNC_get_current_task: 1121 return &bpf_get_current_task_proto; 1122 case BPF_FUNC_get_current_task_btf: 1123 return &bpf_get_current_task_btf_proto; 1124 case BPF_FUNC_task_pt_regs: 1125 return &bpf_task_pt_regs_proto; 1126 case BPF_FUNC_get_current_uid_gid: 1127 return &bpf_get_current_uid_gid_proto; 1128 case BPF_FUNC_get_current_comm: 1129 return &bpf_get_current_comm_proto; 1130 case BPF_FUNC_trace_printk: 1131 return bpf_get_trace_printk_proto(); 1132 case BPF_FUNC_get_smp_processor_id: 1133 return &bpf_get_smp_processor_id_proto; 1134 case BPF_FUNC_get_numa_node_id: 1135 return &bpf_get_numa_node_id_proto; 1136 case BPF_FUNC_perf_event_read: 1137 return &bpf_perf_event_read_proto; 1138 case BPF_FUNC_current_task_under_cgroup: 1139 return &bpf_current_task_under_cgroup_proto; 1140 case BPF_FUNC_get_prandom_u32: 1141 return &bpf_get_prandom_u32_proto; 1142 case BPF_FUNC_probe_write_user: 1143 return security_locked_down(LOCKDOWN_BPF_WRITE_USER) < 0 ? 1144 NULL : bpf_get_probe_write_proto(); 1145 case BPF_FUNC_probe_read_user: 1146 return &bpf_probe_read_user_proto; 1147 case BPF_FUNC_probe_read_kernel: 1148 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1149 NULL : &bpf_probe_read_kernel_proto; 1150 case BPF_FUNC_probe_read_user_str: 1151 return &bpf_probe_read_user_str_proto; 1152 case BPF_FUNC_probe_read_kernel_str: 1153 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1154 NULL : &bpf_probe_read_kernel_str_proto; 1155 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 1156 case BPF_FUNC_probe_read: 1157 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1158 NULL : &bpf_probe_read_compat_proto; 1159 case BPF_FUNC_probe_read_str: 1160 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1161 NULL : &bpf_probe_read_compat_str_proto; 1162 #endif 1163 #ifdef CONFIG_CGROUPS 1164 case BPF_FUNC_get_current_cgroup_id: 1165 return &bpf_get_current_cgroup_id_proto; 1166 case BPF_FUNC_get_current_ancestor_cgroup_id: 1167 return &bpf_get_current_ancestor_cgroup_id_proto; 1168 #endif 1169 case BPF_FUNC_send_signal: 1170 return &bpf_send_signal_proto; 1171 case BPF_FUNC_send_signal_thread: 1172 return &bpf_send_signal_thread_proto; 1173 case BPF_FUNC_perf_event_read_value: 1174 return &bpf_perf_event_read_value_proto; 1175 case BPF_FUNC_get_ns_current_pid_tgid: 1176 return &bpf_get_ns_current_pid_tgid_proto; 1177 case BPF_FUNC_ringbuf_output: 1178 return &bpf_ringbuf_output_proto; 1179 case BPF_FUNC_ringbuf_reserve: 1180 return &bpf_ringbuf_reserve_proto; 1181 case BPF_FUNC_ringbuf_submit: 1182 return &bpf_ringbuf_submit_proto; 1183 case BPF_FUNC_ringbuf_discard: 1184 return &bpf_ringbuf_discard_proto; 1185 case BPF_FUNC_ringbuf_query: 1186 return &bpf_ringbuf_query_proto; 1187 case BPF_FUNC_jiffies64: 1188 return &bpf_jiffies64_proto; 1189 case BPF_FUNC_get_task_stack: 1190 return &bpf_get_task_stack_proto; 1191 case BPF_FUNC_copy_from_user: 1192 return prog->aux->sleepable ? &bpf_copy_from_user_proto : NULL; 1193 case BPF_FUNC_snprintf_btf: 1194 return &bpf_snprintf_btf_proto; 1195 case BPF_FUNC_per_cpu_ptr: 1196 return &bpf_per_cpu_ptr_proto; 1197 case BPF_FUNC_this_cpu_ptr: 1198 return &bpf_this_cpu_ptr_proto; 1199 case BPF_FUNC_task_storage_get: 1200 return &bpf_task_storage_get_proto; 1201 case BPF_FUNC_task_storage_delete: 1202 return &bpf_task_storage_delete_proto; 1203 case BPF_FUNC_for_each_map_elem: 1204 return &bpf_for_each_map_elem_proto; 1205 case BPF_FUNC_snprintf: 1206 return &bpf_snprintf_proto; 1207 case BPF_FUNC_get_func_ip: 1208 return &bpf_get_func_ip_proto_tracing; 1209 case BPF_FUNC_get_branch_snapshot: 1210 return &bpf_get_branch_snapshot_proto; 1211 case BPF_FUNC_trace_vprintk: 1212 return bpf_get_trace_vprintk_proto(); 1213 default: 1214 return bpf_base_func_proto(func_id); 1215 } 1216 } 1217 1218 static const struct bpf_func_proto * 1219 kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1220 { 1221 switch (func_id) { 1222 case BPF_FUNC_perf_event_output: 1223 return &bpf_perf_event_output_proto; 1224 case BPF_FUNC_get_stackid: 1225 return &bpf_get_stackid_proto; 1226 case BPF_FUNC_get_stack: 1227 return &bpf_get_stack_proto; 1228 #ifdef CONFIG_BPF_KPROBE_OVERRIDE 1229 case BPF_FUNC_override_return: 1230 return &bpf_override_return_proto; 1231 #endif 1232 case BPF_FUNC_get_func_ip: 1233 return &bpf_get_func_ip_proto_kprobe; 1234 case BPF_FUNC_get_attach_cookie: 1235 return &bpf_get_attach_cookie_proto_trace; 1236 default: 1237 return bpf_tracing_func_proto(func_id, prog); 1238 } 1239 } 1240 1241 /* bpf+kprobe programs can access fields of 'struct pt_regs' */ 1242 static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type, 1243 const struct bpf_prog *prog, 1244 struct bpf_insn_access_aux *info) 1245 { 1246 if (off < 0 || off >= sizeof(struct pt_regs)) 1247 return false; 1248 if (type != BPF_READ) 1249 return false; 1250 if (off % size != 0) 1251 return false; 1252 /* 1253 * Assertion for 32 bit to make sure last 8 byte access 1254 * (BPF_DW) to the last 4 byte member is disallowed. 1255 */ 1256 if (off + size > sizeof(struct pt_regs)) 1257 return false; 1258 1259 return true; 1260 } 1261 1262 const struct bpf_verifier_ops kprobe_verifier_ops = { 1263 .get_func_proto = kprobe_prog_func_proto, 1264 .is_valid_access = kprobe_prog_is_valid_access, 1265 }; 1266 1267 const struct bpf_prog_ops kprobe_prog_ops = { 1268 }; 1269 1270 BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map, 1271 u64, flags, void *, data, u64, size) 1272 { 1273 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1274 1275 /* 1276 * r1 points to perf tracepoint buffer where first 8 bytes are hidden 1277 * from bpf program and contain a pointer to 'struct pt_regs'. Fetch it 1278 * from there and call the same bpf_perf_event_output() helper inline. 1279 */ 1280 return ____bpf_perf_event_output(regs, map, flags, data, size); 1281 } 1282 1283 static const struct bpf_func_proto bpf_perf_event_output_proto_tp = { 1284 .func = bpf_perf_event_output_tp, 1285 .gpl_only = true, 1286 .ret_type = RET_INTEGER, 1287 .arg1_type = ARG_PTR_TO_CTX, 1288 .arg2_type = ARG_CONST_MAP_PTR, 1289 .arg3_type = ARG_ANYTHING, 1290 .arg4_type = ARG_PTR_TO_MEM, 1291 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 1292 }; 1293 1294 BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map, 1295 u64, flags) 1296 { 1297 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1298 1299 /* 1300 * Same comment as in bpf_perf_event_output_tp(), only that this time 1301 * the other helper's function body cannot be inlined due to being 1302 * external, thus we need to call raw helper function. 1303 */ 1304 return bpf_get_stackid((unsigned long) regs, (unsigned long) map, 1305 flags, 0, 0); 1306 } 1307 1308 static const struct bpf_func_proto bpf_get_stackid_proto_tp = { 1309 .func = bpf_get_stackid_tp, 1310 .gpl_only = true, 1311 .ret_type = RET_INTEGER, 1312 .arg1_type = ARG_PTR_TO_CTX, 1313 .arg2_type = ARG_CONST_MAP_PTR, 1314 .arg3_type = ARG_ANYTHING, 1315 }; 1316 1317 BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size, 1318 u64, flags) 1319 { 1320 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1321 1322 return bpf_get_stack((unsigned long) regs, (unsigned long) buf, 1323 (unsigned long) size, flags, 0); 1324 } 1325 1326 static const struct bpf_func_proto bpf_get_stack_proto_tp = { 1327 .func = bpf_get_stack_tp, 1328 .gpl_only = true, 1329 .ret_type = RET_INTEGER, 1330 .arg1_type = ARG_PTR_TO_CTX, 1331 .arg2_type = ARG_PTR_TO_UNINIT_MEM, 1332 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1333 .arg4_type = ARG_ANYTHING, 1334 }; 1335 1336 static const struct bpf_func_proto * 1337 tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1338 { 1339 switch (func_id) { 1340 case BPF_FUNC_perf_event_output: 1341 return &bpf_perf_event_output_proto_tp; 1342 case BPF_FUNC_get_stackid: 1343 return &bpf_get_stackid_proto_tp; 1344 case BPF_FUNC_get_stack: 1345 return &bpf_get_stack_proto_tp; 1346 case BPF_FUNC_get_attach_cookie: 1347 return &bpf_get_attach_cookie_proto_trace; 1348 default: 1349 return bpf_tracing_func_proto(func_id, prog); 1350 } 1351 } 1352 1353 static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type, 1354 const struct bpf_prog *prog, 1355 struct bpf_insn_access_aux *info) 1356 { 1357 if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE) 1358 return false; 1359 if (type != BPF_READ) 1360 return false; 1361 if (off % size != 0) 1362 return false; 1363 1364 BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(__u64)); 1365 return true; 1366 } 1367 1368 const struct bpf_verifier_ops tracepoint_verifier_ops = { 1369 .get_func_proto = tp_prog_func_proto, 1370 .is_valid_access = tp_prog_is_valid_access, 1371 }; 1372 1373 const struct bpf_prog_ops tracepoint_prog_ops = { 1374 }; 1375 1376 BPF_CALL_3(bpf_perf_prog_read_value, struct bpf_perf_event_data_kern *, ctx, 1377 struct bpf_perf_event_value *, buf, u32, size) 1378 { 1379 int err = -EINVAL; 1380 1381 if (unlikely(size != sizeof(struct bpf_perf_event_value))) 1382 goto clear; 1383 err = perf_event_read_local(ctx->event, &buf->counter, &buf->enabled, 1384 &buf->running); 1385 if (unlikely(err)) 1386 goto clear; 1387 return 0; 1388 clear: 1389 memset(buf, 0, size); 1390 return err; 1391 } 1392 1393 static const struct bpf_func_proto bpf_perf_prog_read_value_proto = { 1394 .func = bpf_perf_prog_read_value, 1395 .gpl_only = true, 1396 .ret_type = RET_INTEGER, 1397 .arg1_type = ARG_PTR_TO_CTX, 1398 .arg2_type = ARG_PTR_TO_UNINIT_MEM, 1399 .arg3_type = ARG_CONST_SIZE, 1400 }; 1401 1402 BPF_CALL_4(bpf_read_branch_records, struct bpf_perf_event_data_kern *, ctx, 1403 void *, buf, u32, size, u64, flags) 1404 { 1405 #ifndef CONFIG_X86 1406 return -ENOENT; 1407 #else 1408 static const u32 br_entry_size = sizeof(struct perf_branch_entry); 1409 struct perf_branch_stack *br_stack = ctx->data->br_stack; 1410 u32 to_copy; 1411 1412 if (unlikely(flags & ~BPF_F_GET_BRANCH_RECORDS_SIZE)) 1413 return -EINVAL; 1414 1415 if (unlikely(!br_stack)) 1416 return -EINVAL; 1417 1418 if (flags & BPF_F_GET_BRANCH_RECORDS_SIZE) 1419 return br_stack->nr * br_entry_size; 1420 1421 if (!buf || (size % br_entry_size != 0)) 1422 return -EINVAL; 1423 1424 to_copy = min_t(u32, br_stack->nr * br_entry_size, size); 1425 memcpy(buf, br_stack->entries, to_copy); 1426 1427 return to_copy; 1428 #endif 1429 } 1430 1431 static const struct bpf_func_proto bpf_read_branch_records_proto = { 1432 .func = bpf_read_branch_records, 1433 .gpl_only = true, 1434 .ret_type = RET_INTEGER, 1435 .arg1_type = ARG_PTR_TO_CTX, 1436 .arg2_type = ARG_PTR_TO_MEM_OR_NULL, 1437 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1438 .arg4_type = ARG_ANYTHING, 1439 }; 1440 1441 static const struct bpf_func_proto * 1442 pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1443 { 1444 switch (func_id) { 1445 case BPF_FUNC_perf_event_output: 1446 return &bpf_perf_event_output_proto_tp; 1447 case BPF_FUNC_get_stackid: 1448 return &bpf_get_stackid_proto_pe; 1449 case BPF_FUNC_get_stack: 1450 return &bpf_get_stack_proto_pe; 1451 case BPF_FUNC_perf_prog_read_value: 1452 return &bpf_perf_prog_read_value_proto; 1453 case BPF_FUNC_read_branch_records: 1454 return &bpf_read_branch_records_proto; 1455 case BPF_FUNC_get_attach_cookie: 1456 return &bpf_get_attach_cookie_proto_pe; 1457 default: 1458 return bpf_tracing_func_proto(func_id, prog); 1459 } 1460 } 1461 1462 /* 1463 * bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp 1464 * to avoid potential recursive reuse issue when/if tracepoints are added 1465 * inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack. 1466 * 1467 * Since raw tracepoints run despite bpf_prog_active, support concurrent usage 1468 * in normal, irq, and nmi context. 1469 */ 1470 struct bpf_raw_tp_regs { 1471 struct pt_regs regs[3]; 1472 }; 1473 static DEFINE_PER_CPU(struct bpf_raw_tp_regs, bpf_raw_tp_regs); 1474 static DEFINE_PER_CPU(int, bpf_raw_tp_nest_level); 1475 static struct pt_regs *get_bpf_raw_tp_regs(void) 1476 { 1477 struct bpf_raw_tp_regs *tp_regs = this_cpu_ptr(&bpf_raw_tp_regs); 1478 int nest_level = this_cpu_inc_return(bpf_raw_tp_nest_level); 1479 1480 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(tp_regs->regs))) { 1481 this_cpu_dec(bpf_raw_tp_nest_level); 1482 return ERR_PTR(-EBUSY); 1483 } 1484 1485 return &tp_regs->regs[nest_level - 1]; 1486 } 1487 1488 static void put_bpf_raw_tp_regs(void) 1489 { 1490 this_cpu_dec(bpf_raw_tp_nest_level); 1491 } 1492 1493 BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args, 1494 struct bpf_map *, map, u64, flags, void *, data, u64, size) 1495 { 1496 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1497 int ret; 1498 1499 if (IS_ERR(regs)) 1500 return PTR_ERR(regs); 1501 1502 perf_fetch_caller_regs(regs); 1503 ret = ____bpf_perf_event_output(regs, map, flags, data, size); 1504 1505 put_bpf_raw_tp_regs(); 1506 return ret; 1507 } 1508 1509 static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = { 1510 .func = bpf_perf_event_output_raw_tp, 1511 .gpl_only = true, 1512 .ret_type = RET_INTEGER, 1513 .arg1_type = ARG_PTR_TO_CTX, 1514 .arg2_type = ARG_CONST_MAP_PTR, 1515 .arg3_type = ARG_ANYTHING, 1516 .arg4_type = ARG_PTR_TO_MEM, 1517 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 1518 }; 1519 1520 extern const struct bpf_func_proto bpf_skb_output_proto; 1521 extern const struct bpf_func_proto bpf_xdp_output_proto; 1522 1523 BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args, 1524 struct bpf_map *, map, u64, flags) 1525 { 1526 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1527 int ret; 1528 1529 if (IS_ERR(regs)) 1530 return PTR_ERR(regs); 1531 1532 perf_fetch_caller_regs(regs); 1533 /* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */ 1534 ret = bpf_get_stackid((unsigned long) regs, (unsigned long) map, 1535 flags, 0, 0); 1536 put_bpf_raw_tp_regs(); 1537 return ret; 1538 } 1539 1540 static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = { 1541 .func = bpf_get_stackid_raw_tp, 1542 .gpl_only = true, 1543 .ret_type = RET_INTEGER, 1544 .arg1_type = ARG_PTR_TO_CTX, 1545 .arg2_type = ARG_CONST_MAP_PTR, 1546 .arg3_type = ARG_ANYTHING, 1547 }; 1548 1549 BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args, 1550 void *, buf, u32, size, u64, flags) 1551 { 1552 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1553 int ret; 1554 1555 if (IS_ERR(regs)) 1556 return PTR_ERR(regs); 1557 1558 perf_fetch_caller_regs(regs); 1559 ret = bpf_get_stack((unsigned long) regs, (unsigned long) buf, 1560 (unsigned long) size, flags, 0); 1561 put_bpf_raw_tp_regs(); 1562 return ret; 1563 } 1564 1565 static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = { 1566 .func = bpf_get_stack_raw_tp, 1567 .gpl_only = true, 1568 .ret_type = RET_INTEGER, 1569 .arg1_type = ARG_PTR_TO_CTX, 1570 .arg2_type = ARG_PTR_TO_MEM, 1571 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1572 .arg4_type = ARG_ANYTHING, 1573 }; 1574 1575 static const struct bpf_func_proto * 1576 raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1577 { 1578 switch (func_id) { 1579 case BPF_FUNC_perf_event_output: 1580 return &bpf_perf_event_output_proto_raw_tp; 1581 case BPF_FUNC_get_stackid: 1582 return &bpf_get_stackid_proto_raw_tp; 1583 case BPF_FUNC_get_stack: 1584 return &bpf_get_stack_proto_raw_tp; 1585 default: 1586 return bpf_tracing_func_proto(func_id, prog); 1587 } 1588 } 1589 1590 const struct bpf_func_proto * 1591 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1592 { 1593 const struct bpf_func_proto *fn; 1594 1595 switch (func_id) { 1596 #ifdef CONFIG_NET 1597 case BPF_FUNC_skb_output: 1598 return &bpf_skb_output_proto; 1599 case BPF_FUNC_xdp_output: 1600 return &bpf_xdp_output_proto; 1601 case BPF_FUNC_skc_to_tcp6_sock: 1602 return &bpf_skc_to_tcp6_sock_proto; 1603 case BPF_FUNC_skc_to_tcp_sock: 1604 return &bpf_skc_to_tcp_sock_proto; 1605 case BPF_FUNC_skc_to_tcp_timewait_sock: 1606 return &bpf_skc_to_tcp_timewait_sock_proto; 1607 case BPF_FUNC_skc_to_tcp_request_sock: 1608 return &bpf_skc_to_tcp_request_sock_proto; 1609 case BPF_FUNC_skc_to_udp6_sock: 1610 return &bpf_skc_to_udp6_sock_proto; 1611 case BPF_FUNC_sk_storage_get: 1612 return &bpf_sk_storage_get_tracing_proto; 1613 case BPF_FUNC_sk_storage_delete: 1614 return &bpf_sk_storage_delete_tracing_proto; 1615 case BPF_FUNC_sock_from_file: 1616 return &bpf_sock_from_file_proto; 1617 case BPF_FUNC_get_socket_cookie: 1618 return &bpf_get_socket_ptr_cookie_proto; 1619 #endif 1620 case BPF_FUNC_seq_printf: 1621 return prog->expected_attach_type == BPF_TRACE_ITER ? 1622 &bpf_seq_printf_proto : 1623 NULL; 1624 case BPF_FUNC_seq_write: 1625 return prog->expected_attach_type == BPF_TRACE_ITER ? 1626 &bpf_seq_write_proto : 1627 NULL; 1628 case BPF_FUNC_seq_printf_btf: 1629 return prog->expected_attach_type == BPF_TRACE_ITER ? 1630 &bpf_seq_printf_btf_proto : 1631 NULL; 1632 case BPF_FUNC_d_path: 1633 return &bpf_d_path_proto; 1634 default: 1635 fn = raw_tp_prog_func_proto(func_id, prog); 1636 if (!fn && prog->expected_attach_type == BPF_TRACE_ITER) 1637 fn = bpf_iter_get_func_proto(func_id, prog); 1638 return fn; 1639 } 1640 } 1641 1642 static bool raw_tp_prog_is_valid_access(int off, int size, 1643 enum bpf_access_type type, 1644 const struct bpf_prog *prog, 1645 struct bpf_insn_access_aux *info) 1646 { 1647 if (off < 0 || off >= sizeof(__u64) * MAX_BPF_FUNC_ARGS) 1648 return false; 1649 if (type != BPF_READ) 1650 return false; 1651 if (off % size != 0) 1652 return false; 1653 return true; 1654 } 1655 1656 static bool tracing_prog_is_valid_access(int off, int size, 1657 enum bpf_access_type type, 1658 const struct bpf_prog *prog, 1659 struct bpf_insn_access_aux *info) 1660 { 1661 if (off < 0 || off >= sizeof(__u64) * MAX_BPF_FUNC_ARGS) 1662 return false; 1663 if (type != BPF_READ) 1664 return false; 1665 if (off % size != 0) 1666 return false; 1667 return btf_ctx_access(off, size, type, prog, info); 1668 } 1669 1670 int __weak bpf_prog_test_run_tracing(struct bpf_prog *prog, 1671 const union bpf_attr *kattr, 1672 union bpf_attr __user *uattr) 1673 { 1674 return -ENOTSUPP; 1675 } 1676 1677 const struct bpf_verifier_ops raw_tracepoint_verifier_ops = { 1678 .get_func_proto = raw_tp_prog_func_proto, 1679 .is_valid_access = raw_tp_prog_is_valid_access, 1680 }; 1681 1682 const struct bpf_prog_ops raw_tracepoint_prog_ops = { 1683 #ifdef CONFIG_NET 1684 .test_run = bpf_prog_test_run_raw_tp, 1685 #endif 1686 }; 1687 1688 const struct bpf_verifier_ops tracing_verifier_ops = { 1689 .get_func_proto = tracing_prog_func_proto, 1690 .is_valid_access = tracing_prog_is_valid_access, 1691 }; 1692 1693 const struct bpf_prog_ops tracing_prog_ops = { 1694 .test_run = bpf_prog_test_run_tracing, 1695 }; 1696 1697 static bool raw_tp_writable_prog_is_valid_access(int off, int size, 1698 enum bpf_access_type type, 1699 const struct bpf_prog *prog, 1700 struct bpf_insn_access_aux *info) 1701 { 1702 if (off == 0) { 1703 if (size != sizeof(u64) || type != BPF_READ) 1704 return false; 1705 info->reg_type = PTR_TO_TP_BUFFER; 1706 } 1707 return raw_tp_prog_is_valid_access(off, size, type, prog, info); 1708 } 1709 1710 const struct bpf_verifier_ops raw_tracepoint_writable_verifier_ops = { 1711 .get_func_proto = raw_tp_prog_func_proto, 1712 .is_valid_access = raw_tp_writable_prog_is_valid_access, 1713 }; 1714 1715 const struct bpf_prog_ops raw_tracepoint_writable_prog_ops = { 1716 }; 1717 1718 static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type, 1719 const struct bpf_prog *prog, 1720 struct bpf_insn_access_aux *info) 1721 { 1722 const int size_u64 = sizeof(u64); 1723 1724 if (off < 0 || off >= sizeof(struct bpf_perf_event_data)) 1725 return false; 1726 if (type != BPF_READ) 1727 return false; 1728 if (off % size != 0) { 1729 if (sizeof(unsigned long) != 4) 1730 return false; 1731 if (size != 8) 1732 return false; 1733 if (off % size != 4) 1734 return false; 1735 } 1736 1737 switch (off) { 1738 case bpf_ctx_range(struct bpf_perf_event_data, sample_period): 1739 bpf_ctx_record_field_size(info, size_u64); 1740 if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) 1741 return false; 1742 break; 1743 case bpf_ctx_range(struct bpf_perf_event_data, addr): 1744 bpf_ctx_record_field_size(info, size_u64); 1745 if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) 1746 return false; 1747 break; 1748 default: 1749 if (size != sizeof(long)) 1750 return false; 1751 } 1752 1753 return true; 1754 } 1755 1756 static u32 pe_prog_convert_ctx_access(enum bpf_access_type type, 1757 const struct bpf_insn *si, 1758 struct bpf_insn *insn_buf, 1759 struct bpf_prog *prog, u32 *target_size) 1760 { 1761 struct bpf_insn *insn = insn_buf; 1762 1763 switch (si->off) { 1764 case offsetof(struct bpf_perf_event_data, sample_period): 1765 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 1766 data), si->dst_reg, si->src_reg, 1767 offsetof(struct bpf_perf_event_data_kern, data)); 1768 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, 1769 bpf_target_off(struct perf_sample_data, period, 8, 1770 target_size)); 1771 break; 1772 case offsetof(struct bpf_perf_event_data, addr): 1773 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 1774 data), si->dst_reg, si->src_reg, 1775 offsetof(struct bpf_perf_event_data_kern, data)); 1776 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, 1777 bpf_target_off(struct perf_sample_data, addr, 8, 1778 target_size)); 1779 break; 1780 default: 1781 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 1782 regs), si->dst_reg, si->src_reg, 1783 offsetof(struct bpf_perf_event_data_kern, regs)); 1784 *insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg, 1785 si->off); 1786 break; 1787 } 1788 1789 return insn - insn_buf; 1790 } 1791 1792 const struct bpf_verifier_ops perf_event_verifier_ops = { 1793 .get_func_proto = pe_prog_func_proto, 1794 .is_valid_access = pe_prog_is_valid_access, 1795 .convert_ctx_access = pe_prog_convert_ctx_access, 1796 }; 1797 1798 const struct bpf_prog_ops perf_event_prog_ops = { 1799 }; 1800 1801 static DEFINE_MUTEX(bpf_event_mutex); 1802 1803 #define BPF_TRACE_MAX_PROGS 64 1804 1805 int perf_event_attach_bpf_prog(struct perf_event *event, 1806 struct bpf_prog *prog, 1807 u64 bpf_cookie) 1808 { 1809 struct bpf_prog_array *old_array; 1810 struct bpf_prog_array *new_array; 1811 int ret = -EEXIST; 1812 1813 /* 1814 * Kprobe override only works if they are on the function entry, 1815 * and only if they are on the opt-in list. 1816 */ 1817 if (prog->kprobe_override && 1818 (!trace_kprobe_on_func_entry(event->tp_event) || 1819 !trace_kprobe_error_injectable(event->tp_event))) 1820 return -EINVAL; 1821 1822 mutex_lock(&bpf_event_mutex); 1823 1824 if (event->prog) 1825 goto unlock; 1826 1827 old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); 1828 if (old_array && 1829 bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) { 1830 ret = -E2BIG; 1831 goto unlock; 1832 } 1833 1834 ret = bpf_prog_array_copy(old_array, NULL, prog, bpf_cookie, &new_array); 1835 if (ret < 0) 1836 goto unlock; 1837 1838 /* set the new array to event->tp_event and set event->prog */ 1839 event->prog = prog; 1840 event->bpf_cookie = bpf_cookie; 1841 rcu_assign_pointer(event->tp_event->prog_array, new_array); 1842 bpf_prog_array_free(old_array); 1843 1844 unlock: 1845 mutex_unlock(&bpf_event_mutex); 1846 return ret; 1847 } 1848 1849 void perf_event_detach_bpf_prog(struct perf_event *event) 1850 { 1851 struct bpf_prog_array *old_array; 1852 struct bpf_prog_array *new_array; 1853 int ret; 1854 1855 mutex_lock(&bpf_event_mutex); 1856 1857 if (!event->prog) 1858 goto unlock; 1859 1860 old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); 1861 ret = bpf_prog_array_copy(old_array, event->prog, NULL, 0, &new_array); 1862 if (ret == -ENOENT) 1863 goto unlock; 1864 if (ret < 0) { 1865 bpf_prog_array_delete_safe(old_array, event->prog); 1866 } else { 1867 rcu_assign_pointer(event->tp_event->prog_array, new_array); 1868 bpf_prog_array_free(old_array); 1869 } 1870 1871 bpf_prog_put(event->prog); 1872 event->prog = NULL; 1873 1874 unlock: 1875 mutex_unlock(&bpf_event_mutex); 1876 } 1877 1878 int perf_event_query_prog_array(struct perf_event *event, void __user *info) 1879 { 1880 struct perf_event_query_bpf __user *uquery = info; 1881 struct perf_event_query_bpf query = {}; 1882 struct bpf_prog_array *progs; 1883 u32 *ids, prog_cnt, ids_len; 1884 int ret; 1885 1886 if (!perfmon_capable()) 1887 return -EPERM; 1888 if (event->attr.type != PERF_TYPE_TRACEPOINT) 1889 return -EINVAL; 1890 if (copy_from_user(&query, uquery, sizeof(query))) 1891 return -EFAULT; 1892 1893 ids_len = query.ids_len; 1894 if (ids_len > BPF_TRACE_MAX_PROGS) 1895 return -E2BIG; 1896 ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN); 1897 if (!ids) 1898 return -ENOMEM; 1899 /* 1900 * The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which 1901 * is required when user only wants to check for uquery->prog_cnt. 1902 * There is no need to check for it since the case is handled 1903 * gracefully in bpf_prog_array_copy_info. 1904 */ 1905 1906 mutex_lock(&bpf_event_mutex); 1907 progs = bpf_event_rcu_dereference(event->tp_event->prog_array); 1908 ret = bpf_prog_array_copy_info(progs, ids, ids_len, &prog_cnt); 1909 mutex_unlock(&bpf_event_mutex); 1910 1911 if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) || 1912 copy_to_user(uquery->ids, ids, ids_len * sizeof(u32))) 1913 ret = -EFAULT; 1914 1915 kfree(ids); 1916 return ret; 1917 } 1918 1919 extern struct bpf_raw_event_map __start__bpf_raw_tp[]; 1920 extern struct bpf_raw_event_map __stop__bpf_raw_tp[]; 1921 1922 struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name) 1923 { 1924 struct bpf_raw_event_map *btp = __start__bpf_raw_tp; 1925 1926 for (; btp < __stop__bpf_raw_tp; btp++) { 1927 if (!strcmp(btp->tp->name, name)) 1928 return btp; 1929 } 1930 1931 return bpf_get_raw_tracepoint_module(name); 1932 } 1933 1934 void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp) 1935 { 1936 struct module *mod; 1937 1938 preempt_disable(); 1939 mod = __module_address((unsigned long)btp); 1940 module_put(mod); 1941 preempt_enable(); 1942 } 1943 1944 static __always_inline 1945 void __bpf_trace_run(struct bpf_prog *prog, u64 *args) 1946 { 1947 cant_sleep(); 1948 rcu_read_lock(); 1949 (void) bpf_prog_run(prog, args); 1950 rcu_read_unlock(); 1951 } 1952 1953 #define UNPACK(...) __VA_ARGS__ 1954 #define REPEAT_1(FN, DL, X, ...) FN(X) 1955 #define REPEAT_2(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__) 1956 #define REPEAT_3(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_2(FN, DL, __VA_ARGS__) 1957 #define REPEAT_4(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_3(FN, DL, __VA_ARGS__) 1958 #define REPEAT_5(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_4(FN, DL, __VA_ARGS__) 1959 #define REPEAT_6(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_5(FN, DL, __VA_ARGS__) 1960 #define REPEAT_7(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_6(FN, DL, __VA_ARGS__) 1961 #define REPEAT_8(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_7(FN, DL, __VA_ARGS__) 1962 #define REPEAT_9(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_8(FN, DL, __VA_ARGS__) 1963 #define REPEAT_10(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_9(FN, DL, __VA_ARGS__) 1964 #define REPEAT_11(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_10(FN, DL, __VA_ARGS__) 1965 #define REPEAT_12(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_11(FN, DL, __VA_ARGS__) 1966 #define REPEAT(X, FN, DL, ...) REPEAT_##X(FN, DL, __VA_ARGS__) 1967 1968 #define SARG(X) u64 arg##X 1969 #define COPY(X) args[X] = arg##X 1970 1971 #define __DL_COM (,) 1972 #define __DL_SEM (;) 1973 1974 #define __SEQ_0_11 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 1975 1976 #define BPF_TRACE_DEFN_x(x) \ 1977 void bpf_trace_run##x(struct bpf_prog *prog, \ 1978 REPEAT(x, SARG, __DL_COM, __SEQ_0_11)) \ 1979 { \ 1980 u64 args[x]; \ 1981 REPEAT(x, COPY, __DL_SEM, __SEQ_0_11); \ 1982 __bpf_trace_run(prog, args); \ 1983 } \ 1984 EXPORT_SYMBOL_GPL(bpf_trace_run##x) 1985 BPF_TRACE_DEFN_x(1); 1986 BPF_TRACE_DEFN_x(2); 1987 BPF_TRACE_DEFN_x(3); 1988 BPF_TRACE_DEFN_x(4); 1989 BPF_TRACE_DEFN_x(5); 1990 BPF_TRACE_DEFN_x(6); 1991 BPF_TRACE_DEFN_x(7); 1992 BPF_TRACE_DEFN_x(8); 1993 BPF_TRACE_DEFN_x(9); 1994 BPF_TRACE_DEFN_x(10); 1995 BPF_TRACE_DEFN_x(11); 1996 BPF_TRACE_DEFN_x(12); 1997 1998 static int __bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog) 1999 { 2000 struct tracepoint *tp = btp->tp; 2001 2002 /* 2003 * check that program doesn't access arguments beyond what's 2004 * available in this tracepoint 2005 */ 2006 if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64)) 2007 return -EINVAL; 2008 2009 if (prog->aux->max_tp_access > btp->writable_size) 2010 return -EINVAL; 2011 2012 return tracepoint_probe_register_may_exist(tp, (void *)btp->bpf_func, 2013 prog); 2014 } 2015 2016 int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog) 2017 { 2018 return __bpf_probe_register(btp, prog); 2019 } 2020 2021 int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_prog *prog) 2022 { 2023 return tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, prog); 2024 } 2025 2026 int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id, 2027 u32 *fd_type, const char **buf, 2028 u64 *probe_offset, u64 *probe_addr) 2029 { 2030 bool is_tracepoint, is_syscall_tp; 2031 struct bpf_prog *prog; 2032 int flags, err = 0; 2033 2034 prog = event->prog; 2035 if (!prog) 2036 return -ENOENT; 2037 2038 /* not supporting BPF_PROG_TYPE_PERF_EVENT yet */ 2039 if (prog->type == BPF_PROG_TYPE_PERF_EVENT) 2040 return -EOPNOTSUPP; 2041 2042 *prog_id = prog->aux->id; 2043 flags = event->tp_event->flags; 2044 is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT; 2045 is_syscall_tp = is_syscall_trace_event(event->tp_event); 2046 2047 if (is_tracepoint || is_syscall_tp) { 2048 *buf = is_tracepoint ? event->tp_event->tp->name 2049 : event->tp_event->name; 2050 *fd_type = BPF_FD_TYPE_TRACEPOINT; 2051 *probe_offset = 0x0; 2052 *probe_addr = 0x0; 2053 } else { 2054 /* kprobe/uprobe */ 2055 err = -EOPNOTSUPP; 2056 #ifdef CONFIG_KPROBE_EVENTS 2057 if (flags & TRACE_EVENT_FL_KPROBE) 2058 err = bpf_get_kprobe_info(event, fd_type, buf, 2059 probe_offset, probe_addr, 2060 event->attr.type == PERF_TYPE_TRACEPOINT); 2061 #endif 2062 #ifdef CONFIG_UPROBE_EVENTS 2063 if (flags & TRACE_EVENT_FL_UPROBE) 2064 err = bpf_get_uprobe_info(event, fd_type, buf, 2065 probe_offset, 2066 event->attr.type == PERF_TYPE_TRACEPOINT); 2067 #endif 2068 } 2069 2070 return err; 2071 } 2072 2073 static int __init send_signal_irq_work_init(void) 2074 { 2075 int cpu; 2076 struct send_signal_irq_work *work; 2077 2078 for_each_possible_cpu(cpu) { 2079 work = per_cpu_ptr(&send_signal_work, cpu); 2080 init_irq_work(&work->irq_work, do_bpf_send_signal); 2081 } 2082 return 0; 2083 } 2084 2085 subsys_initcall(send_signal_irq_work_init); 2086 2087 #ifdef CONFIG_MODULES 2088 static int bpf_event_notify(struct notifier_block *nb, unsigned long op, 2089 void *module) 2090 { 2091 struct bpf_trace_module *btm, *tmp; 2092 struct module *mod = module; 2093 int ret = 0; 2094 2095 if (mod->num_bpf_raw_events == 0 || 2096 (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING)) 2097 goto out; 2098 2099 mutex_lock(&bpf_module_mutex); 2100 2101 switch (op) { 2102 case MODULE_STATE_COMING: 2103 btm = kzalloc(sizeof(*btm), GFP_KERNEL); 2104 if (btm) { 2105 btm->module = module; 2106 list_add(&btm->list, &bpf_trace_modules); 2107 } else { 2108 ret = -ENOMEM; 2109 } 2110 break; 2111 case MODULE_STATE_GOING: 2112 list_for_each_entry_safe(btm, tmp, &bpf_trace_modules, list) { 2113 if (btm->module == module) { 2114 list_del(&btm->list); 2115 kfree(btm); 2116 break; 2117 } 2118 } 2119 break; 2120 } 2121 2122 mutex_unlock(&bpf_module_mutex); 2123 2124 out: 2125 return notifier_from_errno(ret); 2126 } 2127 2128 static struct notifier_block bpf_module_nb = { 2129 .notifier_call = bpf_event_notify, 2130 }; 2131 2132 static int __init bpf_event_init(void) 2133 { 2134 register_module_notifier(&bpf_module_nb); 2135 return 0; 2136 } 2137 2138 fs_initcall(bpf_event_init); 2139 #endif /* CONFIG_MODULES */ 2140