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_verifier.h> 10 #include <linux/bpf_perf_event.h> 11 #include <linux/btf.h> 12 #include <linux/filter.h> 13 #include <linux/uaccess.h> 14 #include <linux/ctype.h> 15 #include <linux/kprobes.h> 16 #include <linux/spinlock.h> 17 #include <linux/syscalls.h> 18 #include <linux/error-injection.h> 19 #include <linux/btf_ids.h> 20 #include <linux/bpf_lsm.h> 21 #include <linux/fprobe.h> 22 #include <linux/bsearch.h> 23 #include <linux/sort.h> 24 #include <linux/key.h> 25 #include <linux/verification.h> 26 27 #include <net/bpf_sk_storage.h> 28 29 #include <uapi/linux/bpf.h> 30 #include <uapi/linux/btf.h> 31 32 #include <asm/tlb.h> 33 34 #include "trace_probe.h" 35 #include "trace.h" 36 37 #define CREATE_TRACE_POINTS 38 #include "bpf_trace.h" 39 40 #define bpf_event_rcu_dereference(p) \ 41 rcu_dereference_protected(p, lockdep_is_held(&bpf_event_mutex)) 42 43 #ifdef CONFIG_MODULES 44 struct bpf_trace_module { 45 struct module *module; 46 struct list_head list; 47 }; 48 49 static LIST_HEAD(bpf_trace_modules); 50 static DEFINE_MUTEX(bpf_module_mutex); 51 52 static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name) 53 { 54 struct bpf_raw_event_map *btp, *ret = NULL; 55 struct bpf_trace_module *btm; 56 unsigned int i; 57 58 mutex_lock(&bpf_module_mutex); 59 list_for_each_entry(btm, &bpf_trace_modules, list) { 60 for (i = 0; i < btm->module->num_bpf_raw_events; ++i) { 61 btp = &btm->module->bpf_raw_events[i]; 62 if (!strcmp(btp->tp->name, name)) { 63 if (try_module_get(btm->module)) 64 ret = btp; 65 goto out; 66 } 67 } 68 } 69 out: 70 mutex_unlock(&bpf_module_mutex); 71 return ret; 72 } 73 #else 74 static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name) 75 { 76 return NULL; 77 } 78 #endif /* CONFIG_MODULES */ 79 80 u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); 81 u64 bpf_get_stack(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); 82 83 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size, 84 u64 flags, const struct btf **btf, 85 s32 *btf_id); 86 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx); 87 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx); 88 89 /** 90 * trace_call_bpf - invoke BPF program 91 * @call: tracepoint event 92 * @ctx: opaque context pointer 93 * 94 * kprobe handlers execute BPF programs via this helper. 95 * Can be used from static tracepoints in the future. 96 * 97 * Return: BPF programs always return an integer which is interpreted by 98 * kprobe handler as: 99 * 0 - return from kprobe (event is filtered out) 100 * 1 - store kprobe event into ring buffer 101 * Other values are reserved and currently alias to 1 102 */ 103 unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx) 104 { 105 unsigned int ret; 106 107 cant_sleep(); 108 109 if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) { 110 /* 111 * since some bpf program is already running on this cpu, 112 * don't call into another bpf program (same or different) 113 * and don't send kprobe event into ring-buffer, 114 * so return zero here 115 */ 116 ret = 0; 117 goto out; 118 } 119 120 /* 121 * Instead of moving rcu_read_lock/rcu_dereference/rcu_read_unlock 122 * to all call sites, we did a bpf_prog_array_valid() there to check 123 * whether call->prog_array is empty or not, which is 124 * a heuristic to speed up execution. 125 * 126 * If bpf_prog_array_valid() fetched prog_array was 127 * non-NULL, we go into trace_call_bpf() and do the actual 128 * proper rcu_dereference() under RCU lock. 129 * If it turns out that prog_array is NULL then, we bail out. 130 * For the opposite, if the bpf_prog_array_valid() fetched pointer 131 * was NULL, you'll skip the prog_array with the risk of missing 132 * out of events when it was updated in between this and the 133 * rcu_dereference() which is accepted risk. 134 */ 135 rcu_read_lock(); 136 ret = bpf_prog_run_array(rcu_dereference(call->prog_array), 137 ctx, bpf_prog_run); 138 rcu_read_unlock(); 139 140 out: 141 __this_cpu_dec(bpf_prog_active); 142 143 return ret; 144 } 145 146 #ifdef CONFIG_BPF_KPROBE_OVERRIDE 147 BPF_CALL_2(bpf_override_return, struct pt_regs *, regs, unsigned long, rc) 148 { 149 regs_set_return_value(regs, rc); 150 override_function_with_return(regs); 151 return 0; 152 } 153 154 static const struct bpf_func_proto bpf_override_return_proto = { 155 .func = bpf_override_return, 156 .gpl_only = true, 157 .ret_type = RET_INTEGER, 158 .arg1_type = ARG_PTR_TO_CTX, 159 .arg2_type = ARG_ANYTHING, 160 }; 161 #endif 162 163 static __always_inline int 164 bpf_probe_read_user_common(void *dst, u32 size, const void __user *unsafe_ptr) 165 { 166 int ret; 167 168 ret = copy_from_user_nofault(dst, unsafe_ptr, size); 169 if (unlikely(ret < 0)) 170 memset(dst, 0, size); 171 return ret; 172 } 173 174 BPF_CALL_3(bpf_probe_read_user, void *, dst, u32, size, 175 const void __user *, unsafe_ptr) 176 { 177 return bpf_probe_read_user_common(dst, size, unsafe_ptr); 178 } 179 180 const struct bpf_func_proto bpf_probe_read_user_proto = { 181 .func = bpf_probe_read_user, 182 .gpl_only = true, 183 .ret_type = RET_INTEGER, 184 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 185 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 186 .arg3_type = ARG_ANYTHING, 187 }; 188 189 static __always_inline int 190 bpf_probe_read_user_str_common(void *dst, u32 size, 191 const void __user *unsafe_ptr) 192 { 193 int ret; 194 195 /* 196 * NB: We rely on strncpy_from_user() not copying junk past the NUL 197 * terminator into `dst`. 198 * 199 * strncpy_from_user() does long-sized strides in the fast path. If the 200 * strncpy does not mask out the bytes after the NUL in `unsafe_ptr`, 201 * then there could be junk after the NUL in `dst`. If user takes `dst` 202 * and keys a hash map with it, then semantically identical strings can 203 * occupy multiple entries in the map. 204 */ 205 ret = strncpy_from_user_nofault(dst, unsafe_ptr, size); 206 if (unlikely(ret < 0)) 207 memset(dst, 0, size); 208 return ret; 209 } 210 211 BPF_CALL_3(bpf_probe_read_user_str, void *, dst, u32, size, 212 const void __user *, unsafe_ptr) 213 { 214 return bpf_probe_read_user_str_common(dst, size, unsafe_ptr); 215 } 216 217 const struct bpf_func_proto bpf_probe_read_user_str_proto = { 218 .func = bpf_probe_read_user_str, 219 .gpl_only = true, 220 .ret_type = RET_INTEGER, 221 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 222 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 223 .arg3_type = ARG_ANYTHING, 224 }; 225 226 static __always_inline int 227 bpf_probe_read_kernel_common(void *dst, u32 size, const void *unsafe_ptr) 228 { 229 int ret; 230 231 ret = copy_from_kernel_nofault(dst, unsafe_ptr, size); 232 if (unlikely(ret < 0)) 233 memset(dst, 0, size); 234 return ret; 235 } 236 237 BPF_CALL_3(bpf_probe_read_kernel, void *, dst, u32, size, 238 const void *, unsafe_ptr) 239 { 240 return bpf_probe_read_kernel_common(dst, size, unsafe_ptr); 241 } 242 243 const struct bpf_func_proto bpf_probe_read_kernel_proto = { 244 .func = bpf_probe_read_kernel, 245 .gpl_only = true, 246 .ret_type = RET_INTEGER, 247 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 248 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 249 .arg3_type = ARG_ANYTHING, 250 }; 251 252 static __always_inline int 253 bpf_probe_read_kernel_str_common(void *dst, u32 size, const void *unsafe_ptr) 254 { 255 int ret; 256 257 /* 258 * The strncpy_from_kernel_nofault() call will likely not fill the 259 * entire buffer, but that's okay in this circumstance as we're probing 260 * arbitrary memory anyway similar to bpf_probe_read_*() and might 261 * as well probe the stack. Thus, memory is explicitly cleared 262 * only in error case, so that improper users ignoring return 263 * code altogether don't copy garbage; otherwise length of string 264 * is returned that can be used for bpf_perf_event_output() et al. 265 */ 266 ret = strncpy_from_kernel_nofault(dst, unsafe_ptr, size); 267 if (unlikely(ret < 0)) 268 memset(dst, 0, size); 269 return ret; 270 } 271 272 BPF_CALL_3(bpf_probe_read_kernel_str, void *, dst, u32, size, 273 const void *, unsafe_ptr) 274 { 275 return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr); 276 } 277 278 const struct bpf_func_proto bpf_probe_read_kernel_str_proto = { 279 .func = bpf_probe_read_kernel_str, 280 .gpl_only = true, 281 .ret_type = RET_INTEGER, 282 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 283 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 284 .arg3_type = ARG_ANYTHING, 285 }; 286 287 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 288 BPF_CALL_3(bpf_probe_read_compat, void *, dst, u32, size, 289 const void *, unsafe_ptr) 290 { 291 if ((unsigned long)unsafe_ptr < TASK_SIZE) { 292 return bpf_probe_read_user_common(dst, size, 293 (__force void __user *)unsafe_ptr); 294 } 295 return bpf_probe_read_kernel_common(dst, size, unsafe_ptr); 296 } 297 298 static const struct bpf_func_proto bpf_probe_read_compat_proto = { 299 .func = bpf_probe_read_compat, 300 .gpl_only = true, 301 .ret_type = RET_INTEGER, 302 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 303 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 304 .arg3_type = ARG_ANYTHING, 305 }; 306 307 BPF_CALL_3(bpf_probe_read_compat_str, void *, dst, u32, size, 308 const void *, unsafe_ptr) 309 { 310 if ((unsigned long)unsafe_ptr < TASK_SIZE) { 311 return bpf_probe_read_user_str_common(dst, size, 312 (__force void __user *)unsafe_ptr); 313 } 314 return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr); 315 } 316 317 static const struct bpf_func_proto bpf_probe_read_compat_str_proto = { 318 .func = bpf_probe_read_compat_str, 319 .gpl_only = true, 320 .ret_type = RET_INTEGER, 321 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 322 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 323 .arg3_type = ARG_ANYTHING, 324 }; 325 #endif /* CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE */ 326 327 BPF_CALL_3(bpf_probe_write_user, void __user *, unsafe_ptr, const void *, src, 328 u32, size) 329 { 330 /* 331 * Ensure we're in user context which is safe for the helper to 332 * run. This helper has no business in a kthread. 333 * 334 * access_ok() should prevent writing to non-user memory, but in 335 * some situations (nommu, temporary switch, etc) access_ok() does 336 * not provide enough validation, hence the check on KERNEL_DS. 337 * 338 * nmi_uaccess_okay() ensures the probe is not run in an interim 339 * state, when the task or mm are switched. This is specifically 340 * required to prevent the use of temporary mm. 341 */ 342 343 if (unlikely(in_interrupt() || 344 current->flags & (PF_KTHREAD | PF_EXITING))) 345 return -EPERM; 346 if (unlikely(!nmi_uaccess_okay())) 347 return -EPERM; 348 349 return copy_to_user_nofault(unsafe_ptr, src, size); 350 } 351 352 static const struct bpf_func_proto bpf_probe_write_user_proto = { 353 .func = bpf_probe_write_user, 354 .gpl_only = true, 355 .ret_type = RET_INTEGER, 356 .arg1_type = ARG_ANYTHING, 357 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 358 .arg3_type = ARG_CONST_SIZE, 359 }; 360 361 static const struct bpf_func_proto *bpf_get_probe_write_proto(void) 362 { 363 if (!capable(CAP_SYS_ADMIN)) 364 return NULL; 365 366 pr_warn_ratelimited("%s[%d] is installing a program with bpf_probe_write_user helper that may corrupt user memory!", 367 current->comm, task_pid_nr(current)); 368 369 return &bpf_probe_write_user_proto; 370 } 371 372 #define MAX_TRACE_PRINTK_VARARGS 3 373 #define BPF_TRACE_PRINTK_SIZE 1024 374 375 BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1, 376 u64, arg2, u64, arg3) 377 { 378 u64 args[MAX_TRACE_PRINTK_VARARGS] = { arg1, arg2, arg3 }; 379 struct bpf_bprintf_data data = { 380 .get_bin_args = true, 381 .get_buf = true, 382 }; 383 int ret; 384 385 ret = bpf_bprintf_prepare(fmt, fmt_size, args, 386 MAX_TRACE_PRINTK_VARARGS, &data); 387 if (ret < 0) 388 return ret; 389 390 ret = bstr_printf(data.buf, MAX_BPRINTF_BUF, fmt, data.bin_args); 391 392 trace_bpf_trace_printk(data.buf); 393 394 bpf_bprintf_cleanup(&data); 395 396 return ret; 397 } 398 399 static const struct bpf_func_proto bpf_trace_printk_proto = { 400 .func = bpf_trace_printk, 401 .gpl_only = true, 402 .ret_type = RET_INTEGER, 403 .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY, 404 .arg2_type = ARG_CONST_SIZE, 405 }; 406 407 static void __set_printk_clr_event(void) 408 { 409 /* 410 * This program might be calling bpf_trace_printk, 411 * so enable the associated bpf_trace/bpf_trace_printk event. 412 * Repeat this each time as it is possible a user has 413 * disabled bpf_trace_printk events. By loading a program 414 * calling bpf_trace_printk() however the user has expressed 415 * the intent to see such events. 416 */ 417 if (trace_set_clr_event("bpf_trace", "bpf_trace_printk", 1)) 418 pr_warn_ratelimited("could not enable bpf_trace_printk events"); 419 } 420 421 const struct bpf_func_proto *bpf_get_trace_printk_proto(void) 422 { 423 __set_printk_clr_event(); 424 return &bpf_trace_printk_proto; 425 } 426 427 BPF_CALL_4(bpf_trace_vprintk, char *, fmt, u32, fmt_size, const void *, args, 428 u32, data_len) 429 { 430 struct bpf_bprintf_data data = { 431 .get_bin_args = true, 432 .get_buf = true, 433 }; 434 int ret, num_args; 435 436 if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 || 437 (data_len && !args)) 438 return -EINVAL; 439 num_args = data_len / 8; 440 441 ret = bpf_bprintf_prepare(fmt, fmt_size, args, num_args, &data); 442 if (ret < 0) 443 return ret; 444 445 ret = bstr_printf(data.buf, MAX_BPRINTF_BUF, fmt, data.bin_args); 446 447 trace_bpf_trace_printk(data.buf); 448 449 bpf_bprintf_cleanup(&data); 450 451 return ret; 452 } 453 454 static const struct bpf_func_proto bpf_trace_vprintk_proto = { 455 .func = bpf_trace_vprintk, 456 .gpl_only = true, 457 .ret_type = RET_INTEGER, 458 .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY, 459 .arg2_type = ARG_CONST_SIZE, 460 .arg3_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY, 461 .arg4_type = ARG_CONST_SIZE_OR_ZERO, 462 }; 463 464 const struct bpf_func_proto *bpf_get_trace_vprintk_proto(void) 465 { 466 __set_printk_clr_event(); 467 return &bpf_trace_vprintk_proto; 468 } 469 470 BPF_CALL_5(bpf_seq_printf, struct seq_file *, m, char *, fmt, u32, fmt_size, 471 const void *, args, u32, data_len) 472 { 473 struct bpf_bprintf_data data = { 474 .get_bin_args = true, 475 }; 476 int err, num_args; 477 478 if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 || 479 (data_len && !args)) 480 return -EINVAL; 481 num_args = data_len / 8; 482 483 err = bpf_bprintf_prepare(fmt, fmt_size, args, num_args, &data); 484 if (err < 0) 485 return err; 486 487 seq_bprintf(m, fmt, data.bin_args); 488 489 bpf_bprintf_cleanup(&data); 490 491 return seq_has_overflowed(m) ? -EOVERFLOW : 0; 492 } 493 494 BTF_ID_LIST_SINGLE(btf_seq_file_ids, struct, seq_file) 495 496 static const struct bpf_func_proto bpf_seq_printf_proto = { 497 .func = bpf_seq_printf, 498 .gpl_only = true, 499 .ret_type = RET_INTEGER, 500 .arg1_type = ARG_PTR_TO_BTF_ID, 501 .arg1_btf_id = &btf_seq_file_ids[0], 502 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 503 .arg3_type = ARG_CONST_SIZE, 504 .arg4_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY, 505 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 506 }; 507 508 BPF_CALL_3(bpf_seq_write, struct seq_file *, m, const void *, data, u32, len) 509 { 510 return seq_write(m, data, len) ? -EOVERFLOW : 0; 511 } 512 513 static const struct bpf_func_proto bpf_seq_write_proto = { 514 .func = bpf_seq_write, 515 .gpl_only = true, 516 .ret_type = RET_INTEGER, 517 .arg1_type = ARG_PTR_TO_BTF_ID, 518 .arg1_btf_id = &btf_seq_file_ids[0], 519 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 520 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 521 }; 522 523 BPF_CALL_4(bpf_seq_printf_btf, struct seq_file *, m, struct btf_ptr *, ptr, 524 u32, btf_ptr_size, u64, flags) 525 { 526 const struct btf *btf; 527 s32 btf_id; 528 int ret; 529 530 ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id); 531 if (ret) 532 return ret; 533 534 return btf_type_seq_show_flags(btf, btf_id, ptr->ptr, m, flags); 535 } 536 537 static const struct bpf_func_proto bpf_seq_printf_btf_proto = { 538 .func = bpf_seq_printf_btf, 539 .gpl_only = true, 540 .ret_type = RET_INTEGER, 541 .arg1_type = ARG_PTR_TO_BTF_ID, 542 .arg1_btf_id = &btf_seq_file_ids[0], 543 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 544 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 545 .arg4_type = ARG_ANYTHING, 546 }; 547 548 static __always_inline int 549 get_map_perf_counter(struct bpf_map *map, u64 flags, 550 u64 *value, u64 *enabled, u64 *running) 551 { 552 struct bpf_array *array = container_of(map, struct bpf_array, map); 553 unsigned int cpu = smp_processor_id(); 554 u64 index = flags & BPF_F_INDEX_MASK; 555 struct bpf_event_entry *ee; 556 557 if (unlikely(flags & ~(BPF_F_INDEX_MASK))) 558 return -EINVAL; 559 if (index == BPF_F_CURRENT_CPU) 560 index = cpu; 561 if (unlikely(index >= array->map.max_entries)) 562 return -E2BIG; 563 564 ee = READ_ONCE(array->ptrs[index]); 565 if (!ee) 566 return -ENOENT; 567 568 return perf_event_read_local(ee->event, value, enabled, running); 569 } 570 571 BPF_CALL_2(bpf_perf_event_read, struct bpf_map *, map, u64, flags) 572 { 573 u64 value = 0; 574 int err; 575 576 err = get_map_perf_counter(map, flags, &value, NULL, NULL); 577 /* 578 * this api is ugly since we miss [-22..-2] range of valid 579 * counter values, but that's uapi 580 */ 581 if (err) 582 return err; 583 return value; 584 } 585 586 static const struct bpf_func_proto bpf_perf_event_read_proto = { 587 .func = bpf_perf_event_read, 588 .gpl_only = true, 589 .ret_type = RET_INTEGER, 590 .arg1_type = ARG_CONST_MAP_PTR, 591 .arg2_type = ARG_ANYTHING, 592 }; 593 594 BPF_CALL_4(bpf_perf_event_read_value, struct bpf_map *, map, u64, flags, 595 struct bpf_perf_event_value *, buf, u32, size) 596 { 597 int err = -EINVAL; 598 599 if (unlikely(size != sizeof(struct bpf_perf_event_value))) 600 goto clear; 601 err = get_map_perf_counter(map, flags, &buf->counter, &buf->enabled, 602 &buf->running); 603 if (unlikely(err)) 604 goto clear; 605 return 0; 606 clear: 607 memset(buf, 0, size); 608 return err; 609 } 610 611 static const struct bpf_func_proto bpf_perf_event_read_value_proto = { 612 .func = bpf_perf_event_read_value, 613 .gpl_only = true, 614 .ret_type = RET_INTEGER, 615 .arg1_type = ARG_CONST_MAP_PTR, 616 .arg2_type = ARG_ANYTHING, 617 .arg3_type = ARG_PTR_TO_UNINIT_MEM, 618 .arg4_type = ARG_CONST_SIZE, 619 }; 620 621 static __always_inline u64 622 __bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map, 623 u64 flags, struct perf_sample_data *sd) 624 { 625 struct bpf_array *array = container_of(map, struct bpf_array, map); 626 unsigned int cpu = smp_processor_id(); 627 u64 index = flags & BPF_F_INDEX_MASK; 628 struct bpf_event_entry *ee; 629 struct perf_event *event; 630 631 if (index == BPF_F_CURRENT_CPU) 632 index = cpu; 633 if (unlikely(index >= array->map.max_entries)) 634 return -E2BIG; 635 636 ee = READ_ONCE(array->ptrs[index]); 637 if (!ee) 638 return -ENOENT; 639 640 event = ee->event; 641 if (unlikely(event->attr.type != PERF_TYPE_SOFTWARE || 642 event->attr.config != PERF_COUNT_SW_BPF_OUTPUT)) 643 return -EINVAL; 644 645 if (unlikely(event->oncpu != cpu)) 646 return -EOPNOTSUPP; 647 648 return perf_event_output(event, sd, regs); 649 } 650 651 /* 652 * Support executing tracepoints in normal, irq, and nmi context that each call 653 * bpf_perf_event_output 654 */ 655 struct bpf_trace_sample_data { 656 struct perf_sample_data sds[3]; 657 }; 658 659 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_trace_sds); 660 static DEFINE_PER_CPU(int, bpf_trace_nest_level); 661 BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map, 662 u64, flags, void *, data, u64, size) 663 { 664 struct bpf_trace_sample_data *sds; 665 struct perf_raw_record raw = { 666 .frag = { 667 .size = size, 668 .data = data, 669 }, 670 }; 671 struct perf_sample_data *sd; 672 int nest_level, err; 673 674 preempt_disable(); 675 sds = this_cpu_ptr(&bpf_trace_sds); 676 nest_level = this_cpu_inc_return(bpf_trace_nest_level); 677 678 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(sds->sds))) { 679 err = -EBUSY; 680 goto out; 681 } 682 683 sd = &sds->sds[nest_level - 1]; 684 685 if (unlikely(flags & ~(BPF_F_INDEX_MASK))) { 686 err = -EINVAL; 687 goto out; 688 } 689 690 perf_sample_data_init(sd, 0, 0); 691 perf_sample_save_raw_data(sd, &raw); 692 693 err = __bpf_perf_event_output(regs, map, flags, sd); 694 out: 695 this_cpu_dec(bpf_trace_nest_level); 696 preempt_enable(); 697 return err; 698 } 699 700 static const struct bpf_func_proto bpf_perf_event_output_proto = { 701 .func = bpf_perf_event_output, 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 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, 708 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 709 }; 710 711 static DEFINE_PER_CPU(int, bpf_event_output_nest_level); 712 struct bpf_nested_pt_regs { 713 struct pt_regs regs[3]; 714 }; 715 static DEFINE_PER_CPU(struct bpf_nested_pt_regs, bpf_pt_regs); 716 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_misc_sds); 717 718 u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size, 719 void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy) 720 { 721 struct perf_raw_frag frag = { 722 .copy = ctx_copy, 723 .size = ctx_size, 724 .data = ctx, 725 }; 726 struct perf_raw_record raw = { 727 .frag = { 728 { 729 .next = ctx_size ? &frag : NULL, 730 }, 731 .size = meta_size, 732 .data = meta, 733 }, 734 }; 735 struct perf_sample_data *sd; 736 struct pt_regs *regs; 737 int nest_level; 738 u64 ret; 739 740 preempt_disable(); 741 nest_level = this_cpu_inc_return(bpf_event_output_nest_level); 742 743 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(bpf_misc_sds.sds))) { 744 ret = -EBUSY; 745 goto out; 746 } 747 sd = this_cpu_ptr(&bpf_misc_sds.sds[nest_level - 1]); 748 regs = this_cpu_ptr(&bpf_pt_regs.regs[nest_level - 1]); 749 750 perf_fetch_caller_regs(regs); 751 perf_sample_data_init(sd, 0, 0); 752 perf_sample_save_raw_data(sd, &raw); 753 754 ret = __bpf_perf_event_output(regs, map, flags, sd); 755 out: 756 this_cpu_dec(bpf_event_output_nest_level); 757 preempt_enable(); 758 return ret; 759 } 760 761 BPF_CALL_0(bpf_get_current_task) 762 { 763 return (long) current; 764 } 765 766 const struct bpf_func_proto bpf_get_current_task_proto = { 767 .func = bpf_get_current_task, 768 .gpl_only = true, 769 .ret_type = RET_INTEGER, 770 }; 771 772 BPF_CALL_0(bpf_get_current_task_btf) 773 { 774 return (unsigned long) current; 775 } 776 777 const struct bpf_func_proto bpf_get_current_task_btf_proto = { 778 .func = bpf_get_current_task_btf, 779 .gpl_only = true, 780 .ret_type = RET_PTR_TO_BTF_ID_TRUSTED, 781 .ret_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK], 782 }; 783 784 BPF_CALL_1(bpf_task_pt_regs, struct task_struct *, task) 785 { 786 return (unsigned long) task_pt_regs(task); 787 } 788 789 BTF_ID_LIST(bpf_task_pt_regs_ids) 790 BTF_ID(struct, pt_regs) 791 792 const struct bpf_func_proto bpf_task_pt_regs_proto = { 793 .func = bpf_task_pt_regs, 794 .gpl_only = true, 795 .arg1_type = ARG_PTR_TO_BTF_ID, 796 .arg1_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK], 797 .ret_type = RET_PTR_TO_BTF_ID, 798 .ret_btf_id = &bpf_task_pt_regs_ids[0], 799 }; 800 801 BPF_CALL_2(bpf_current_task_under_cgroup, struct bpf_map *, map, u32, idx) 802 { 803 struct bpf_array *array = container_of(map, struct bpf_array, map); 804 struct cgroup *cgrp; 805 806 if (unlikely(idx >= array->map.max_entries)) 807 return -E2BIG; 808 809 cgrp = READ_ONCE(array->ptrs[idx]); 810 if (unlikely(!cgrp)) 811 return -EAGAIN; 812 813 return task_under_cgroup_hierarchy(current, cgrp); 814 } 815 816 static const struct bpf_func_proto bpf_current_task_under_cgroup_proto = { 817 .func = bpf_current_task_under_cgroup, 818 .gpl_only = false, 819 .ret_type = RET_INTEGER, 820 .arg1_type = ARG_CONST_MAP_PTR, 821 .arg2_type = ARG_ANYTHING, 822 }; 823 824 struct send_signal_irq_work { 825 struct irq_work irq_work; 826 struct task_struct *task; 827 u32 sig; 828 enum pid_type type; 829 }; 830 831 static DEFINE_PER_CPU(struct send_signal_irq_work, send_signal_work); 832 833 static void do_bpf_send_signal(struct irq_work *entry) 834 { 835 struct send_signal_irq_work *work; 836 837 work = container_of(entry, struct send_signal_irq_work, irq_work); 838 group_send_sig_info(work->sig, SEND_SIG_PRIV, work->task, work->type); 839 put_task_struct(work->task); 840 } 841 842 static int bpf_send_signal_common(u32 sig, enum pid_type type) 843 { 844 struct send_signal_irq_work *work = NULL; 845 846 /* Similar to bpf_probe_write_user, task needs to be 847 * in a sound condition and kernel memory access be 848 * permitted in order to send signal to the current 849 * task. 850 */ 851 if (unlikely(current->flags & (PF_KTHREAD | PF_EXITING))) 852 return -EPERM; 853 if (unlikely(!nmi_uaccess_okay())) 854 return -EPERM; 855 /* Task should not be pid=1 to avoid kernel panic. */ 856 if (unlikely(is_global_init(current))) 857 return -EPERM; 858 859 if (irqs_disabled()) { 860 /* Do an early check on signal validity. Otherwise, 861 * the error is lost in deferred irq_work. 862 */ 863 if (unlikely(!valid_signal(sig))) 864 return -EINVAL; 865 866 work = this_cpu_ptr(&send_signal_work); 867 if (irq_work_is_busy(&work->irq_work)) 868 return -EBUSY; 869 870 /* Add the current task, which is the target of sending signal, 871 * to the irq_work. The current task may change when queued 872 * irq works get executed. 873 */ 874 work->task = get_task_struct(current); 875 work->sig = sig; 876 work->type = type; 877 irq_work_queue(&work->irq_work); 878 return 0; 879 } 880 881 return group_send_sig_info(sig, SEND_SIG_PRIV, current, type); 882 } 883 884 BPF_CALL_1(bpf_send_signal, u32, sig) 885 { 886 return bpf_send_signal_common(sig, PIDTYPE_TGID); 887 } 888 889 static const struct bpf_func_proto bpf_send_signal_proto = { 890 .func = bpf_send_signal, 891 .gpl_only = false, 892 .ret_type = RET_INTEGER, 893 .arg1_type = ARG_ANYTHING, 894 }; 895 896 BPF_CALL_1(bpf_send_signal_thread, u32, sig) 897 { 898 return bpf_send_signal_common(sig, PIDTYPE_PID); 899 } 900 901 static const struct bpf_func_proto bpf_send_signal_thread_proto = { 902 .func = bpf_send_signal_thread, 903 .gpl_only = false, 904 .ret_type = RET_INTEGER, 905 .arg1_type = ARG_ANYTHING, 906 }; 907 908 BPF_CALL_3(bpf_d_path, struct path *, path, char *, buf, u32, sz) 909 { 910 struct path copy; 911 long len; 912 char *p; 913 914 if (!sz) 915 return 0; 916 917 /* 918 * The path pointer is verified as trusted and safe to use, 919 * but let's double check it's valid anyway to workaround 920 * potentially broken verifier. 921 */ 922 len = copy_from_kernel_nofault(©, path, sizeof(*path)); 923 if (len < 0) 924 return len; 925 926 p = d_path(©, buf, sz); 927 if (IS_ERR(p)) { 928 len = PTR_ERR(p); 929 } else { 930 len = buf + sz - p; 931 memmove(buf, p, len); 932 } 933 934 return len; 935 } 936 937 BTF_SET_START(btf_allowlist_d_path) 938 #ifdef CONFIG_SECURITY 939 BTF_ID(func, security_file_permission) 940 BTF_ID(func, security_inode_getattr) 941 BTF_ID(func, security_file_open) 942 #endif 943 #ifdef CONFIG_SECURITY_PATH 944 BTF_ID(func, security_path_truncate) 945 #endif 946 BTF_ID(func, vfs_truncate) 947 BTF_ID(func, vfs_fallocate) 948 BTF_ID(func, dentry_open) 949 BTF_ID(func, vfs_getattr) 950 BTF_ID(func, filp_close) 951 BTF_SET_END(btf_allowlist_d_path) 952 953 static bool bpf_d_path_allowed(const struct bpf_prog *prog) 954 { 955 if (prog->type == BPF_PROG_TYPE_TRACING && 956 prog->expected_attach_type == BPF_TRACE_ITER) 957 return true; 958 959 if (prog->type == BPF_PROG_TYPE_LSM) 960 return bpf_lsm_is_sleepable_hook(prog->aux->attach_btf_id); 961 962 return btf_id_set_contains(&btf_allowlist_d_path, 963 prog->aux->attach_btf_id); 964 } 965 966 BTF_ID_LIST_SINGLE(bpf_d_path_btf_ids, struct, path) 967 968 static const struct bpf_func_proto bpf_d_path_proto = { 969 .func = bpf_d_path, 970 .gpl_only = false, 971 .ret_type = RET_INTEGER, 972 .arg1_type = ARG_PTR_TO_BTF_ID, 973 .arg1_btf_id = &bpf_d_path_btf_ids[0], 974 .arg2_type = ARG_PTR_TO_MEM, 975 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 976 .allowed = bpf_d_path_allowed, 977 }; 978 979 #define BTF_F_ALL (BTF_F_COMPACT | BTF_F_NONAME | \ 980 BTF_F_PTR_RAW | BTF_F_ZERO) 981 982 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size, 983 u64 flags, const struct btf **btf, 984 s32 *btf_id) 985 { 986 const struct btf_type *t; 987 988 if (unlikely(flags & ~(BTF_F_ALL))) 989 return -EINVAL; 990 991 if (btf_ptr_size != sizeof(struct btf_ptr)) 992 return -EINVAL; 993 994 *btf = bpf_get_btf_vmlinux(); 995 996 if (IS_ERR_OR_NULL(*btf)) 997 return IS_ERR(*btf) ? PTR_ERR(*btf) : -EINVAL; 998 999 if (ptr->type_id > 0) 1000 *btf_id = ptr->type_id; 1001 else 1002 return -EINVAL; 1003 1004 if (*btf_id > 0) 1005 t = btf_type_by_id(*btf, *btf_id); 1006 if (*btf_id <= 0 || !t) 1007 return -ENOENT; 1008 1009 return 0; 1010 } 1011 1012 BPF_CALL_5(bpf_snprintf_btf, char *, str, u32, str_size, struct btf_ptr *, ptr, 1013 u32, btf_ptr_size, u64, flags) 1014 { 1015 const struct btf *btf; 1016 s32 btf_id; 1017 int ret; 1018 1019 ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id); 1020 if (ret) 1021 return ret; 1022 1023 return btf_type_snprintf_show(btf, btf_id, ptr->ptr, str, str_size, 1024 flags); 1025 } 1026 1027 const struct bpf_func_proto bpf_snprintf_btf_proto = { 1028 .func = bpf_snprintf_btf, 1029 .gpl_only = false, 1030 .ret_type = RET_INTEGER, 1031 .arg1_type = ARG_PTR_TO_MEM, 1032 .arg2_type = ARG_CONST_SIZE, 1033 .arg3_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1034 .arg4_type = ARG_CONST_SIZE, 1035 .arg5_type = ARG_ANYTHING, 1036 }; 1037 1038 BPF_CALL_1(bpf_get_func_ip_tracing, void *, ctx) 1039 { 1040 /* This helper call is inlined by verifier. */ 1041 return ((u64 *)ctx)[-2]; 1042 } 1043 1044 static const struct bpf_func_proto bpf_get_func_ip_proto_tracing = { 1045 .func = bpf_get_func_ip_tracing, 1046 .gpl_only = true, 1047 .ret_type = RET_INTEGER, 1048 .arg1_type = ARG_PTR_TO_CTX, 1049 }; 1050 1051 #ifdef CONFIG_X86_KERNEL_IBT 1052 static unsigned long get_entry_ip(unsigned long fentry_ip) 1053 { 1054 u32 instr; 1055 1056 /* Being extra safe in here in case entry ip is on the page-edge. */ 1057 if (get_kernel_nofault(instr, (u32 *) fentry_ip - 1)) 1058 return fentry_ip; 1059 if (is_endbr(instr)) 1060 fentry_ip -= ENDBR_INSN_SIZE; 1061 return fentry_ip; 1062 } 1063 #else 1064 #define get_entry_ip(fentry_ip) fentry_ip 1065 #endif 1066 1067 BPF_CALL_1(bpf_get_func_ip_kprobe, struct pt_regs *, regs) 1068 { 1069 struct kprobe *kp = kprobe_running(); 1070 1071 if (!kp || !(kp->flags & KPROBE_FLAG_ON_FUNC_ENTRY)) 1072 return 0; 1073 1074 return get_entry_ip((uintptr_t)kp->addr); 1075 } 1076 1077 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe = { 1078 .func = bpf_get_func_ip_kprobe, 1079 .gpl_only = true, 1080 .ret_type = RET_INTEGER, 1081 .arg1_type = ARG_PTR_TO_CTX, 1082 }; 1083 1084 BPF_CALL_1(bpf_get_func_ip_kprobe_multi, struct pt_regs *, regs) 1085 { 1086 return bpf_kprobe_multi_entry_ip(current->bpf_ctx); 1087 } 1088 1089 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe_multi = { 1090 .func = bpf_get_func_ip_kprobe_multi, 1091 .gpl_only = false, 1092 .ret_type = RET_INTEGER, 1093 .arg1_type = ARG_PTR_TO_CTX, 1094 }; 1095 1096 BPF_CALL_1(bpf_get_attach_cookie_kprobe_multi, struct pt_regs *, regs) 1097 { 1098 return bpf_kprobe_multi_cookie(current->bpf_ctx); 1099 } 1100 1101 static const struct bpf_func_proto bpf_get_attach_cookie_proto_kmulti = { 1102 .func = bpf_get_attach_cookie_kprobe_multi, 1103 .gpl_only = false, 1104 .ret_type = RET_INTEGER, 1105 .arg1_type = ARG_PTR_TO_CTX, 1106 }; 1107 1108 BPF_CALL_1(bpf_get_attach_cookie_trace, void *, ctx) 1109 { 1110 struct bpf_trace_run_ctx *run_ctx; 1111 1112 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); 1113 return run_ctx->bpf_cookie; 1114 } 1115 1116 static const struct bpf_func_proto bpf_get_attach_cookie_proto_trace = { 1117 .func = bpf_get_attach_cookie_trace, 1118 .gpl_only = false, 1119 .ret_type = RET_INTEGER, 1120 .arg1_type = ARG_PTR_TO_CTX, 1121 }; 1122 1123 BPF_CALL_1(bpf_get_attach_cookie_pe, struct bpf_perf_event_data_kern *, ctx) 1124 { 1125 return ctx->event->bpf_cookie; 1126 } 1127 1128 static const struct bpf_func_proto bpf_get_attach_cookie_proto_pe = { 1129 .func = bpf_get_attach_cookie_pe, 1130 .gpl_only = false, 1131 .ret_type = RET_INTEGER, 1132 .arg1_type = ARG_PTR_TO_CTX, 1133 }; 1134 1135 BPF_CALL_1(bpf_get_attach_cookie_tracing, void *, ctx) 1136 { 1137 struct bpf_trace_run_ctx *run_ctx; 1138 1139 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); 1140 return run_ctx->bpf_cookie; 1141 } 1142 1143 static const struct bpf_func_proto bpf_get_attach_cookie_proto_tracing = { 1144 .func = bpf_get_attach_cookie_tracing, 1145 .gpl_only = false, 1146 .ret_type = RET_INTEGER, 1147 .arg1_type = ARG_PTR_TO_CTX, 1148 }; 1149 1150 BPF_CALL_3(bpf_get_branch_snapshot, void *, buf, u32, size, u64, flags) 1151 { 1152 #ifndef CONFIG_X86 1153 return -ENOENT; 1154 #else 1155 static const u32 br_entry_size = sizeof(struct perf_branch_entry); 1156 u32 entry_cnt = size / br_entry_size; 1157 1158 entry_cnt = static_call(perf_snapshot_branch_stack)(buf, entry_cnt); 1159 1160 if (unlikely(flags)) 1161 return -EINVAL; 1162 1163 if (!entry_cnt) 1164 return -ENOENT; 1165 1166 return entry_cnt * br_entry_size; 1167 #endif 1168 } 1169 1170 static const struct bpf_func_proto bpf_get_branch_snapshot_proto = { 1171 .func = bpf_get_branch_snapshot, 1172 .gpl_only = true, 1173 .ret_type = RET_INTEGER, 1174 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 1175 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 1176 }; 1177 1178 BPF_CALL_3(get_func_arg, void *, ctx, u32, n, u64 *, value) 1179 { 1180 /* This helper call is inlined by verifier. */ 1181 u64 nr_args = ((u64 *)ctx)[-1]; 1182 1183 if ((u64) n >= nr_args) 1184 return -EINVAL; 1185 *value = ((u64 *)ctx)[n]; 1186 return 0; 1187 } 1188 1189 static const struct bpf_func_proto bpf_get_func_arg_proto = { 1190 .func = get_func_arg, 1191 .ret_type = RET_INTEGER, 1192 .arg1_type = ARG_PTR_TO_CTX, 1193 .arg2_type = ARG_ANYTHING, 1194 .arg3_type = ARG_PTR_TO_LONG, 1195 }; 1196 1197 BPF_CALL_2(get_func_ret, void *, ctx, u64 *, value) 1198 { 1199 /* This helper call is inlined by verifier. */ 1200 u64 nr_args = ((u64 *)ctx)[-1]; 1201 1202 *value = ((u64 *)ctx)[nr_args]; 1203 return 0; 1204 } 1205 1206 static const struct bpf_func_proto bpf_get_func_ret_proto = { 1207 .func = get_func_ret, 1208 .ret_type = RET_INTEGER, 1209 .arg1_type = ARG_PTR_TO_CTX, 1210 .arg2_type = ARG_PTR_TO_LONG, 1211 }; 1212 1213 BPF_CALL_1(get_func_arg_cnt, void *, ctx) 1214 { 1215 /* This helper call is inlined by verifier. */ 1216 return ((u64 *)ctx)[-1]; 1217 } 1218 1219 static const struct bpf_func_proto bpf_get_func_arg_cnt_proto = { 1220 .func = get_func_arg_cnt, 1221 .ret_type = RET_INTEGER, 1222 .arg1_type = ARG_PTR_TO_CTX, 1223 }; 1224 1225 #ifdef CONFIG_KEYS 1226 __diag_push(); 1227 __diag_ignore_all("-Wmissing-prototypes", 1228 "kfuncs which will be used in BPF programs"); 1229 1230 /** 1231 * bpf_lookup_user_key - lookup a key by its serial 1232 * @serial: key handle serial number 1233 * @flags: lookup-specific flags 1234 * 1235 * Search a key with a given *serial* and the provided *flags*. 1236 * If found, increment the reference count of the key by one, and 1237 * return it in the bpf_key structure. 1238 * 1239 * The bpf_key structure must be passed to bpf_key_put() when done 1240 * with it, so that the key reference count is decremented and the 1241 * bpf_key structure is freed. 1242 * 1243 * Permission checks are deferred to the time the key is used by 1244 * one of the available key-specific kfuncs. 1245 * 1246 * Set *flags* with KEY_LOOKUP_CREATE, to attempt creating a requested 1247 * special keyring (e.g. session keyring), if it doesn't yet exist. 1248 * Set *flags* with KEY_LOOKUP_PARTIAL, to lookup a key without waiting 1249 * for the key construction, and to retrieve uninstantiated keys (keys 1250 * without data attached to them). 1251 * 1252 * Return: a bpf_key pointer with a valid key pointer if the key is found, a 1253 * NULL pointer otherwise. 1254 */ 1255 __bpf_kfunc struct bpf_key *bpf_lookup_user_key(u32 serial, u64 flags) 1256 { 1257 key_ref_t key_ref; 1258 struct bpf_key *bkey; 1259 1260 if (flags & ~KEY_LOOKUP_ALL) 1261 return NULL; 1262 1263 /* 1264 * Permission check is deferred until the key is used, as the 1265 * intent of the caller is unknown here. 1266 */ 1267 key_ref = lookup_user_key(serial, flags, KEY_DEFER_PERM_CHECK); 1268 if (IS_ERR(key_ref)) 1269 return NULL; 1270 1271 bkey = kmalloc(sizeof(*bkey), GFP_KERNEL); 1272 if (!bkey) { 1273 key_put(key_ref_to_ptr(key_ref)); 1274 return NULL; 1275 } 1276 1277 bkey->key = key_ref_to_ptr(key_ref); 1278 bkey->has_ref = true; 1279 1280 return bkey; 1281 } 1282 1283 /** 1284 * bpf_lookup_system_key - lookup a key by a system-defined ID 1285 * @id: key ID 1286 * 1287 * Obtain a bpf_key structure with a key pointer set to the passed key ID. 1288 * The key pointer is marked as invalid, to prevent bpf_key_put() from 1289 * attempting to decrement the key reference count on that pointer. The key 1290 * pointer set in such way is currently understood only by 1291 * verify_pkcs7_signature(). 1292 * 1293 * Set *id* to one of the values defined in include/linux/verification.h: 1294 * 0 for the primary keyring (immutable keyring of system keys); 1295 * VERIFY_USE_SECONDARY_KEYRING for both the primary and secondary keyring 1296 * (where keys can be added only if they are vouched for by existing keys 1297 * in those keyrings); VERIFY_USE_PLATFORM_KEYRING for the platform 1298 * keyring (primarily used by the integrity subsystem to verify a kexec'ed 1299 * kerned image and, possibly, the initramfs signature). 1300 * 1301 * Return: a bpf_key pointer with an invalid key pointer set from the 1302 * pre-determined ID on success, a NULL pointer otherwise 1303 */ 1304 __bpf_kfunc struct bpf_key *bpf_lookup_system_key(u64 id) 1305 { 1306 struct bpf_key *bkey; 1307 1308 if (system_keyring_id_check(id) < 0) 1309 return NULL; 1310 1311 bkey = kmalloc(sizeof(*bkey), GFP_ATOMIC); 1312 if (!bkey) 1313 return NULL; 1314 1315 bkey->key = (struct key *)(unsigned long)id; 1316 bkey->has_ref = false; 1317 1318 return bkey; 1319 } 1320 1321 /** 1322 * bpf_key_put - decrement key reference count if key is valid and free bpf_key 1323 * @bkey: bpf_key structure 1324 * 1325 * Decrement the reference count of the key inside *bkey*, if the pointer 1326 * is valid, and free *bkey*. 1327 */ 1328 __bpf_kfunc void bpf_key_put(struct bpf_key *bkey) 1329 { 1330 if (bkey->has_ref) 1331 key_put(bkey->key); 1332 1333 kfree(bkey); 1334 } 1335 1336 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION 1337 /** 1338 * bpf_verify_pkcs7_signature - verify a PKCS#7 signature 1339 * @data_ptr: data to verify 1340 * @sig_ptr: signature of the data 1341 * @trusted_keyring: keyring with keys trusted for signature verification 1342 * 1343 * Verify the PKCS#7 signature *sig_ptr* against the supplied *data_ptr* 1344 * with keys in a keyring referenced by *trusted_keyring*. 1345 * 1346 * Return: 0 on success, a negative value on error. 1347 */ 1348 __bpf_kfunc int bpf_verify_pkcs7_signature(struct bpf_dynptr_kern *data_ptr, 1349 struct bpf_dynptr_kern *sig_ptr, 1350 struct bpf_key *trusted_keyring) 1351 { 1352 int ret; 1353 1354 if (trusted_keyring->has_ref) { 1355 /* 1356 * Do the permission check deferred in bpf_lookup_user_key(). 1357 * See bpf_lookup_user_key() for more details. 1358 * 1359 * A call to key_task_permission() here would be redundant, as 1360 * it is already done by keyring_search() called by 1361 * find_asymmetric_key(). 1362 */ 1363 ret = key_validate(trusted_keyring->key); 1364 if (ret < 0) 1365 return ret; 1366 } 1367 1368 return verify_pkcs7_signature(data_ptr->data, 1369 __bpf_dynptr_size(data_ptr), 1370 sig_ptr->data, 1371 __bpf_dynptr_size(sig_ptr), 1372 trusted_keyring->key, 1373 VERIFYING_UNSPECIFIED_SIGNATURE, NULL, 1374 NULL); 1375 } 1376 #endif /* CONFIG_SYSTEM_DATA_VERIFICATION */ 1377 1378 __diag_pop(); 1379 1380 BTF_SET8_START(key_sig_kfunc_set) 1381 BTF_ID_FLAGS(func, bpf_lookup_user_key, KF_ACQUIRE | KF_RET_NULL | KF_SLEEPABLE) 1382 BTF_ID_FLAGS(func, bpf_lookup_system_key, KF_ACQUIRE | KF_RET_NULL) 1383 BTF_ID_FLAGS(func, bpf_key_put, KF_RELEASE) 1384 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION 1385 BTF_ID_FLAGS(func, bpf_verify_pkcs7_signature, KF_SLEEPABLE) 1386 #endif 1387 BTF_SET8_END(key_sig_kfunc_set) 1388 1389 static const struct btf_kfunc_id_set bpf_key_sig_kfunc_set = { 1390 .owner = THIS_MODULE, 1391 .set = &key_sig_kfunc_set, 1392 }; 1393 1394 static int __init bpf_key_sig_kfuncs_init(void) 1395 { 1396 return register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, 1397 &bpf_key_sig_kfunc_set); 1398 } 1399 1400 late_initcall(bpf_key_sig_kfuncs_init); 1401 #endif /* CONFIG_KEYS */ 1402 1403 static const struct bpf_func_proto * 1404 bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1405 { 1406 switch (func_id) { 1407 case BPF_FUNC_map_lookup_elem: 1408 return &bpf_map_lookup_elem_proto; 1409 case BPF_FUNC_map_update_elem: 1410 return &bpf_map_update_elem_proto; 1411 case BPF_FUNC_map_delete_elem: 1412 return &bpf_map_delete_elem_proto; 1413 case BPF_FUNC_map_push_elem: 1414 return &bpf_map_push_elem_proto; 1415 case BPF_FUNC_map_pop_elem: 1416 return &bpf_map_pop_elem_proto; 1417 case BPF_FUNC_map_peek_elem: 1418 return &bpf_map_peek_elem_proto; 1419 case BPF_FUNC_map_lookup_percpu_elem: 1420 return &bpf_map_lookup_percpu_elem_proto; 1421 case BPF_FUNC_ktime_get_ns: 1422 return &bpf_ktime_get_ns_proto; 1423 case BPF_FUNC_ktime_get_boot_ns: 1424 return &bpf_ktime_get_boot_ns_proto; 1425 case BPF_FUNC_tail_call: 1426 return &bpf_tail_call_proto; 1427 case BPF_FUNC_get_current_pid_tgid: 1428 return &bpf_get_current_pid_tgid_proto; 1429 case BPF_FUNC_get_current_task: 1430 return &bpf_get_current_task_proto; 1431 case BPF_FUNC_get_current_task_btf: 1432 return &bpf_get_current_task_btf_proto; 1433 case BPF_FUNC_task_pt_regs: 1434 return &bpf_task_pt_regs_proto; 1435 case BPF_FUNC_get_current_uid_gid: 1436 return &bpf_get_current_uid_gid_proto; 1437 case BPF_FUNC_get_current_comm: 1438 return &bpf_get_current_comm_proto; 1439 case BPF_FUNC_trace_printk: 1440 return bpf_get_trace_printk_proto(); 1441 case BPF_FUNC_get_smp_processor_id: 1442 return &bpf_get_smp_processor_id_proto; 1443 case BPF_FUNC_get_numa_node_id: 1444 return &bpf_get_numa_node_id_proto; 1445 case BPF_FUNC_perf_event_read: 1446 return &bpf_perf_event_read_proto; 1447 case BPF_FUNC_current_task_under_cgroup: 1448 return &bpf_current_task_under_cgroup_proto; 1449 case BPF_FUNC_get_prandom_u32: 1450 return &bpf_get_prandom_u32_proto; 1451 case BPF_FUNC_probe_write_user: 1452 return security_locked_down(LOCKDOWN_BPF_WRITE_USER) < 0 ? 1453 NULL : bpf_get_probe_write_proto(); 1454 case BPF_FUNC_probe_read_user: 1455 return &bpf_probe_read_user_proto; 1456 case BPF_FUNC_probe_read_kernel: 1457 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1458 NULL : &bpf_probe_read_kernel_proto; 1459 case BPF_FUNC_probe_read_user_str: 1460 return &bpf_probe_read_user_str_proto; 1461 case BPF_FUNC_probe_read_kernel_str: 1462 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1463 NULL : &bpf_probe_read_kernel_str_proto; 1464 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 1465 case BPF_FUNC_probe_read: 1466 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1467 NULL : &bpf_probe_read_compat_proto; 1468 case BPF_FUNC_probe_read_str: 1469 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1470 NULL : &bpf_probe_read_compat_str_proto; 1471 #endif 1472 #ifdef CONFIG_CGROUPS 1473 case BPF_FUNC_cgrp_storage_get: 1474 return &bpf_cgrp_storage_get_proto; 1475 case BPF_FUNC_cgrp_storage_delete: 1476 return &bpf_cgrp_storage_delete_proto; 1477 #endif 1478 case BPF_FUNC_send_signal: 1479 return &bpf_send_signal_proto; 1480 case BPF_FUNC_send_signal_thread: 1481 return &bpf_send_signal_thread_proto; 1482 case BPF_FUNC_perf_event_read_value: 1483 return &bpf_perf_event_read_value_proto; 1484 case BPF_FUNC_get_ns_current_pid_tgid: 1485 return &bpf_get_ns_current_pid_tgid_proto; 1486 case BPF_FUNC_ringbuf_output: 1487 return &bpf_ringbuf_output_proto; 1488 case BPF_FUNC_ringbuf_reserve: 1489 return &bpf_ringbuf_reserve_proto; 1490 case BPF_FUNC_ringbuf_submit: 1491 return &bpf_ringbuf_submit_proto; 1492 case BPF_FUNC_ringbuf_discard: 1493 return &bpf_ringbuf_discard_proto; 1494 case BPF_FUNC_ringbuf_query: 1495 return &bpf_ringbuf_query_proto; 1496 case BPF_FUNC_jiffies64: 1497 return &bpf_jiffies64_proto; 1498 case BPF_FUNC_get_task_stack: 1499 return &bpf_get_task_stack_proto; 1500 case BPF_FUNC_copy_from_user: 1501 return &bpf_copy_from_user_proto; 1502 case BPF_FUNC_copy_from_user_task: 1503 return &bpf_copy_from_user_task_proto; 1504 case BPF_FUNC_snprintf_btf: 1505 return &bpf_snprintf_btf_proto; 1506 case BPF_FUNC_per_cpu_ptr: 1507 return &bpf_per_cpu_ptr_proto; 1508 case BPF_FUNC_this_cpu_ptr: 1509 return &bpf_this_cpu_ptr_proto; 1510 case BPF_FUNC_task_storage_get: 1511 if (bpf_prog_check_recur(prog)) 1512 return &bpf_task_storage_get_recur_proto; 1513 return &bpf_task_storage_get_proto; 1514 case BPF_FUNC_task_storage_delete: 1515 if (bpf_prog_check_recur(prog)) 1516 return &bpf_task_storage_delete_recur_proto; 1517 return &bpf_task_storage_delete_proto; 1518 case BPF_FUNC_for_each_map_elem: 1519 return &bpf_for_each_map_elem_proto; 1520 case BPF_FUNC_snprintf: 1521 return &bpf_snprintf_proto; 1522 case BPF_FUNC_get_func_ip: 1523 return &bpf_get_func_ip_proto_tracing; 1524 case BPF_FUNC_get_branch_snapshot: 1525 return &bpf_get_branch_snapshot_proto; 1526 case BPF_FUNC_find_vma: 1527 return &bpf_find_vma_proto; 1528 case BPF_FUNC_trace_vprintk: 1529 return bpf_get_trace_vprintk_proto(); 1530 default: 1531 return bpf_base_func_proto(func_id); 1532 } 1533 } 1534 1535 static const struct bpf_func_proto * 1536 kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1537 { 1538 switch (func_id) { 1539 case BPF_FUNC_perf_event_output: 1540 return &bpf_perf_event_output_proto; 1541 case BPF_FUNC_get_stackid: 1542 return &bpf_get_stackid_proto; 1543 case BPF_FUNC_get_stack: 1544 return &bpf_get_stack_proto; 1545 #ifdef CONFIG_BPF_KPROBE_OVERRIDE 1546 case BPF_FUNC_override_return: 1547 return &bpf_override_return_proto; 1548 #endif 1549 case BPF_FUNC_get_func_ip: 1550 return prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI ? 1551 &bpf_get_func_ip_proto_kprobe_multi : 1552 &bpf_get_func_ip_proto_kprobe; 1553 case BPF_FUNC_get_attach_cookie: 1554 return prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI ? 1555 &bpf_get_attach_cookie_proto_kmulti : 1556 &bpf_get_attach_cookie_proto_trace; 1557 default: 1558 return bpf_tracing_func_proto(func_id, prog); 1559 } 1560 } 1561 1562 /* bpf+kprobe programs can access fields of 'struct pt_regs' */ 1563 static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type, 1564 const struct bpf_prog *prog, 1565 struct bpf_insn_access_aux *info) 1566 { 1567 if (off < 0 || off >= sizeof(struct pt_regs)) 1568 return false; 1569 if (type != BPF_READ) 1570 return false; 1571 if (off % size != 0) 1572 return false; 1573 /* 1574 * Assertion for 32 bit to make sure last 8 byte access 1575 * (BPF_DW) to the last 4 byte member is disallowed. 1576 */ 1577 if (off + size > sizeof(struct pt_regs)) 1578 return false; 1579 1580 return true; 1581 } 1582 1583 const struct bpf_verifier_ops kprobe_verifier_ops = { 1584 .get_func_proto = kprobe_prog_func_proto, 1585 .is_valid_access = kprobe_prog_is_valid_access, 1586 }; 1587 1588 const struct bpf_prog_ops kprobe_prog_ops = { 1589 }; 1590 1591 BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map, 1592 u64, flags, void *, data, u64, size) 1593 { 1594 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1595 1596 /* 1597 * r1 points to perf tracepoint buffer where first 8 bytes are hidden 1598 * from bpf program and contain a pointer to 'struct pt_regs'. Fetch it 1599 * from there and call the same bpf_perf_event_output() helper inline. 1600 */ 1601 return ____bpf_perf_event_output(regs, map, flags, data, size); 1602 } 1603 1604 static const struct bpf_func_proto bpf_perf_event_output_proto_tp = { 1605 .func = bpf_perf_event_output_tp, 1606 .gpl_only = true, 1607 .ret_type = RET_INTEGER, 1608 .arg1_type = ARG_PTR_TO_CTX, 1609 .arg2_type = ARG_CONST_MAP_PTR, 1610 .arg3_type = ARG_ANYTHING, 1611 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1612 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 1613 }; 1614 1615 BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map, 1616 u64, flags) 1617 { 1618 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1619 1620 /* 1621 * Same comment as in bpf_perf_event_output_tp(), only that this time 1622 * the other helper's function body cannot be inlined due to being 1623 * external, thus we need to call raw helper function. 1624 */ 1625 return bpf_get_stackid((unsigned long) regs, (unsigned long) map, 1626 flags, 0, 0); 1627 } 1628 1629 static const struct bpf_func_proto bpf_get_stackid_proto_tp = { 1630 .func = bpf_get_stackid_tp, 1631 .gpl_only = true, 1632 .ret_type = RET_INTEGER, 1633 .arg1_type = ARG_PTR_TO_CTX, 1634 .arg2_type = ARG_CONST_MAP_PTR, 1635 .arg3_type = ARG_ANYTHING, 1636 }; 1637 1638 BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size, 1639 u64, flags) 1640 { 1641 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1642 1643 return bpf_get_stack((unsigned long) regs, (unsigned long) buf, 1644 (unsigned long) size, flags, 0); 1645 } 1646 1647 static const struct bpf_func_proto bpf_get_stack_proto_tp = { 1648 .func = bpf_get_stack_tp, 1649 .gpl_only = true, 1650 .ret_type = RET_INTEGER, 1651 .arg1_type = ARG_PTR_TO_CTX, 1652 .arg2_type = ARG_PTR_TO_UNINIT_MEM, 1653 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1654 .arg4_type = ARG_ANYTHING, 1655 }; 1656 1657 static const struct bpf_func_proto * 1658 tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1659 { 1660 switch (func_id) { 1661 case BPF_FUNC_perf_event_output: 1662 return &bpf_perf_event_output_proto_tp; 1663 case BPF_FUNC_get_stackid: 1664 return &bpf_get_stackid_proto_tp; 1665 case BPF_FUNC_get_stack: 1666 return &bpf_get_stack_proto_tp; 1667 case BPF_FUNC_get_attach_cookie: 1668 return &bpf_get_attach_cookie_proto_trace; 1669 default: 1670 return bpf_tracing_func_proto(func_id, prog); 1671 } 1672 } 1673 1674 static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type, 1675 const struct bpf_prog *prog, 1676 struct bpf_insn_access_aux *info) 1677 { 1678 if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE) 1679 return false; 1680 if (type != BPF_READ) 1681 return false; 1682 if (off % size != 0) 1683 return false; 1684 1685 BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(__u64)); 1686 return true; 1687 } 1688 1689 const struct bpf_verifier_ops tracepoint_verifier_ops = { 1690 .get_func_proto = tp_prog_func_proto, 1691 .is_valid_access = tp_prog_is_valid_access, 1692 }; 1693 1694 const struct bpf_prog_ops tracepoint_prog_ops = { 1695 }; 1696 1697 BPF_CALL_3(bpf_perf_prog_read_value, struct bpf_perf_event_data_kern *, ctx, 1698 struct bpf_perf_event_value *, buf, u32, size) 1699 { 1700 int err = -EINVAL; 1701 1702 if (unlikely(size != sizeof(struct bpf_perf_event_value))) 1703 goto clear; 1704 err = perf_event_read_local(ctx->event, &buf->counter, &buf->enabled, 1705 &buf->running); 1706 if (unlikely(err)) 1707 goto clear; 1708 return 0; 1709 clear: 1710 memset(buf, 0, size); 1711 return err; 1712 } 1713 1714 static const struct bpf_func_proto bpf_perf_prog_read_value_proto = { 1715 .func = bpf_perf_prog_read_value, 1716 .gpl_only = true, 1717 .ret_type = RET_INTEGER, 1718 .arg1_type = ARG_PTR_TO_CTX, 1719 .arg2_type = ARG_PTR_TO_UNINIT_MEM, 1720 .arg3_type = ARG_CONST_SIZE, 1721 }; 1722 1723 BPF_CALL_4(bpf_read_branch_records, struct bpf_perf_event_data_kern *, ctx, 1724 void *, buf, u32, size, u64, flags) 1725 { 1726 static const u32 br_entry_size = sizeof(struct perf_branch_entry); 1727 struct perf_branch_stack *br_stack = ctx->data->br_stack; 1728 u32 to_copy; 1729 1730 if (unlikely(flags & ~BPF_F_GET_BRANCH_RECORDS_SIZE)) 1731 return -EINVAL; 1732 1733 if (unlikely(!(ctx->data->sample_flags & PERF_SAMPLE_BRANCH_STACK))) 1734 return -ENOENT; 1735 1736 if (unlikely(!br_stack)) 1737 return -ENOENT; 1738 1739 if (flags & BPF_F_GET_BRANCH_RECORDS_SIZE) 1740 return br_stack->nr * br_entry_size; 1741 1742 if (!buf || (size % br_entry_size != 0)) 1743 return -EINVAL; 1744 1745 to_copy = min_t(u32, br_stack->nr * br_entry_size, size); 1746 memcpy(buf, br_stack->entries, to_copy); 1747 1748 return to_copy; 1749 } 1750 1751 static const struct bpf_func_proto bpf_read_branch_records_proto = { 1752 .func = bpf_read_branch_records, 1753 .gpl_only = true, 1754 .ret_type = RET_INTEGER, 1755 .arg1_type = ARG_PTR_TO_CTX, 1756 .arg2_type = ARG_PTR_TO_MEM_OR_NULL, 1757 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1758 .arg4_type = ARG_ANYTHING, 1759 }; 1760 1761 static const struct bpf_func_proto * 1762 pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1763 { 1764 switch (func_id) { 1765 case BPF_FUNC_perf_event_output: 1766 return &bpf_perf_event_output_proto_tp; 1767 case BPF_FUNC_get_stackid: 1768 return &bpf_get_stackid_proto_pe; 1769 case BPF_FUNC_get_stack: 1770 return &bpf_get_stack_proto_pe; 1771 case BPF_FUNC_perf_prog_read_value: 1772 return &bpf_perf_prog_read_value_proto; 1773 case BPF_FUNC_read_branch_records: 1774 return &bpf_read_branch_records_proto; 1775 case BPF_FUNC_get_attach_cookie: 1776 return &bpf_get_attach_cookie_proto_pe; 1777 default: 1778 return bpf_tracing_func_proto(func_id, prog); 1779 } 1780 } 1781 1782 /* 1783 * bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp 1784 * to avoid potential recursive reuse issue when/if tracepoints are added 1785 * inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack. 1786 * 1787 * Since raw tracepoints run despite bpf_prog_active, support concurrent usage 1788 * in normal, irq, and nmi context. 1789 */ 1790 struct bpf_raw_tp_regs { 1791 struct pt_regs regs[3]; 1792 }; 1793 static DEFINE_PER_CPU(struct bpf_raw_tp_regs, bpf_raw_tp_regs); 1794 static DEFINE_PER_CPU(int, bpf_raw_tp_nest_level); 1795 static struct pt_regs *get_bpf_raw_tp_regs(void) 1796 { 1797 struct bpf_raw_tp_regs *tp_regs = this_cpu_ptr(&bpf_raw_tp_regs); 1798 int nest_level = this_cpu_inc_return(bpf_raw_tp_nest_level); 1799 1800 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(tp_regs->regs))) { 1801 this_cpu_dec(bpf_raw_tp_nest_level); 1802 return ERR_PTR(-EBUSY); 1803 } 1804 1805 return &tp_regs->regs[nest_level - 1]; 1806 } 1807 1808 static void put_bpf_raw_tp_regs(void) 1809 { 1810 this_cpu_dec(bpf_raw_tp_nest_level); 1811 } 1812 1813 BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args, 1814 struct bpf_map *, map, u64, flags, void *, data, u64, size) 1815 { 1816 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1817 int ret; 1818 1819 if (IS_ERR(regs)) 1820 return PTR_ERR(regs); 1821 1822 perf_fetch_caller_regs(regs); 1823 ret = ____bpf_perf_event_output(regs, map, flags, data, size); 1824 1825 put_bpf_raw_tp_regs(); 1826 return ret; 1827 } 1828 1829 static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = { 1830 .func = bpf_perf_event_output_raw_tp, 1831 .gpl_only = true, 1832 .ret_type = RET_INTEGER, 1833 .arg1_type = ARG_PTR_TO_CTX, 1834 .arg2_type = ARG_CONST_MAP_PTR, 1835 .arg3_type = ARG_ANYTHING, 1836 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1837 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 1838 }; 1839 1840 extern const struct bpf_func_proto bpf_skb_output_proto; 1841 extern const struct bpf_func_proto bpf_xdp_output_proto; 1842 extern const struct bpf_func_proto bpf_xdp_get_buff_len_trace_proto; 1843 1844 BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args, 1845 struct bpf_map *, map, u64, flags) 1846 { 1847 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1848 int ret; 1849 1850 if (IS_ERR(regs)) 1851 return PTR_ERR(regs); 1852 1853 perf_fetch_caller_regs(regs); 1854 /* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */ 1855 ret = bpf_get_stackid((unsigned long) regs, (unsigned long) map, 1856 flags, 0, 0); 1857 put_bpf_raw_tp_regs(); 1858 return ret; 1859 } 1860 1861 static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = { 1862 .func = bpf_get_stackid_raw_tp, 1863 .gpl_only = true, 1864 .ret_type = RET_INTEGER, 1865 .arg1_type = ARG_PTR_TO_CTX, 1866 .arg2_type = ARG_CONST_MAP_PTR, 1867 .arg3_type = ARG_ANYTHING, 1868 }; 1869 1870 BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args, 1871 void *, buf, u32, size, u64, flags) 1872 { 1873 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1874 int ret; 1875 1876 if (IS_ERR(regs)) 1877 return PTR_ERR(regs); 1878 1879 perf_fetch_caller_regs(regs); 1880 ret = bpf_get_stack((unsigned long) regs, (unsigned long) buf, 1881 (unsigned long) size, flags, 0); 1882 put_bpf_raw_tp_regs(); 1883 return ret; 1884 } 1885 1886 static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = { 1887 .func = bpf_get_stack_raw_tp, 1888 .gpl_only = true, 1889 .ret_type = RET_INTEGER, 1890 .arg1_type = ARG_PTR_TO_CTX, 1891 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1892 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1893 .arg4_type = ARG_ANYTHING, 1894 }; 1895 1896 static const struct bpf_func_proto * 1897 raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1898 { 1899 switch (func_id) { 1900 case BPF_FUNC_perf_event_output: 1901 return &bpf_perf_event_output_proto_raw_tp; 1902 case BPF_FUNC_get_stackid: 1903 return &bpf_get_stackid_proto_raw_tp; 1904 case BPF_FUNC_get_stack: 1905 return &bpf_get_stack_proto_raw_tp; 1906 default: 1907 return bpf_tracing_func_proto(func_id, prog); 1908 } 1909 } 1910 1911 const struct bpf_func_proto * 1912 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1913 { 1914 const struct bpf_func_proto *fn; 1915 1916 switch (func_id) { 1917 #ifdef CONFIG_NET 1918 case BPF_FUNC_skb_output: 1919 return &bpf_skb_output_proto; 1920 case BPF_FUNC_xdp_output: 1921 return &bpf_xdp_output_proto; 1922 case BPF_FUNC_skc_to_tcp6_sock: 1923 return &bpf_skc_to_tcp6_sock_proto; 1924 case BPF_FUNC_skc_to_tcp_sock: 1925 return &bpf_skc_to_tcp_sock_proto; 1926 case BPF_FUNC_skc_to_tcp_timewait_sock: 1927 return &bpf_skc_to_tcp_timewait_sock_proto; 1928 case BPF_FUNC_skc_to_tcp_request_sock: 1929 return &bpf_skc_to_tcp_request_sock_proto; 1930 case BPF_FUNC_skc_to_udp6_sock: 1931 return &bpf_skc_to_udp6_sock_proto; 1932 case BPF_FUNC_skc_to_unix_sock: 1933 return &bpf_skc_to_unix_sock_proto; 1934 case BPF_FUNC_skc_to_mptcp_sock: 1935 return &bpf_skc_to_mptcp_sock_proto; 1936 case BPF_FUNC_sk_storage_get: 1937 return &bpf_sk_storage_get_tracing_proto; 1938 case BPF_FUNC_sk_storage_delete: 1939 return &bpf_sk_storage_delete_tracing_proto; 1940 case BPF_FUNC_sock_from_file: 1941 return &bpf_sock_from_file_proto; 1942 case BPF_FUNC_get_socket_cookie: 1943 return &bpf_get_socket_ptr_cookie_proto; 1944 case BPF_FUNC_xdp_get_buff_len: 1945 return &bpf_xdp_get_buff_len_trace_proto; 1946 #endif 1947 case BPF_FUNC_seq_printf: 1948 return prog->expected_attach_type == BPF_TRACE_ITER ? 1949 &bpf_seq_printf_proto : 1950 NULL; 1951 case BPF_FUNC_seq_write: 1952 return prog->expected_attach_type == BPF_TRACE_ITER ? 1953 &bpf_seq_write_proto : 1954 NULL; 1955 case BPF_FUNC_seq_printf_btf: 1956 return prog->expected_attach_type == BPF_TRACE_ITER ? 1957 &bpf_seq_printf_btf_proto : 1958 NULL; 1959 case BPF_FUNC_d_path: 1960 return &bpf_d_path_proto; 1961 case BPF_FUNC_get_func_arg: 1962 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_proto : NULL; 1963 case BPF_FUNC_get_func_ret: 1964 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_ret_proto : NULL; 1965 case BPF_FUNC_get_func_arg_cnt: 1966 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_cnt_proto : NULL; 1967 case BPF_FUNC_get_attach_cookie: 1968 return bpf_prog_has_trampoline(prog) ? &bpf_get_attach_cookie_proto_tracing : NULL; 1969 default: 1970 fn = raw_tp_prog_func_proto(func_id, prog); 1971 if (!fn && prog->expected_attach_type == BPF_TRACE_ITER) 1972 fn = bpf_iter_get_func_proto(func_id, prog); 1973 return fn; 1974 } 1975 } 1976 1977 static bool raw_tp_prog_is_valid_access(int off, int size, 1978 enum bpf_access_type type, 1979 const struct bpf_prog *prog, 1980 struct bpf_insn_access_aux *info) 1981 { 1982 return bpf_tracing_ctx_access(off, size, type); 1983 } 1984 1985 static bool tracing_prog_is_valid_access(int off, int size, 1986 enum bpf_access_type type, 1987 const struct bpf_prog *prog, 1988 struct bpf_insn_access_aux *info) 1989 { 1990 return bpf_tracing_btf_ctx_access(off, size, type, prog, info); 1991 } 1992 1993 int __weak bpf_prog_test_run_tracing(struct bpf_prog *prog, 1994 const union bpf_attr *kattr, 1995 union bpf_attr __user *uattr) 1996 { 1997 return -ENOTSUPP; 1998 } 1999 2000 const struct bpf_verifier_ops raw_tracepoint_verifier_ops = { 2001 .get_func_proto = raw_tp_prog_func_proto, 2002 .is_valid_access = raw_tp_prog_is_valid_access, 2003 }; 2004 2005 const struct bpf_prog_ops raw_tracepoint_prog_ops = { 2006 #ifdef CONFIG_NET 2007 .test_run = bpf_prog_test_run_raw_tp, 2008 #endif 2009 }; 2010 2011 const struct bpf_verifier_ops tracing_verifier_ops = { 2012 .get_func_proto = tracing_prog_func_proto, 2013 .is_valid_access = tracing_prog_is_valid_access, 2014 }; 2015 2016 const struct bpf_prog_ops tracing_prog_ops = { 2017 .test_run = bpf_prog_test_run_tracing, 2018 }; 2019 2020 static bool raw_tp_writable_prog_is_valid_access(int off, int size, 2021 enum bpf_access_type type, 2022 const struct bpf_prog *prog, 2023 struct bpf_insn_access_aux *info) 2024 { 2025 if (off == 0) { 2026 if (size != sizeof(u64) || type != BPF_READ) 2027 return false; 2028 info->reg_type = PTR_TO_TP_BUFFER; 2029 } 2030 return raw_tp_prog_is_valid_access(off, size, type, prog, info); 2031 } 2032 2033 const struct bpf_verifier_ops raw_tracepoint_writable_verifier_ops = { 2034 .get_func_proto = raw_tp_prog_func_proto, 2035 .is_valid_access = raw_tp_writable_prog_is_valid_access, 2036 }; 2037 2038 const struct bpf_prog_ops raw_tracepoint_writable_prog_ops = { 2039 }; 2040 2041 static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type, 2042 const struct bpf_prog *prog, 2043 struct bpf_insn_access_aux *info) 2044 { 2045 const int size_u64 = sizeof(u64); 2046 2047 if (off < 0 || off >= sizeof(struct bpf_perf_event_data)) 2048 return false; 2049 if (type != BPF_READ) 2050 return false; 2051 if (off % size != 0) { 2052 if (sizeof(unsigned long) != 4) 2053 return false; 2054 if (size != 8) 2055 return false; 2056 if (off % size != 4) 2057 return false; 2058 } 2059 2060 switch (off) { 2061 case bpf_ctx_range(struct bpf_perf_event_data, sample_period): 2062 bpf_ctx_record_field_size(info, size_u64); 2063 if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) 2064 return false; 2065 break; 2066 case bpf_ctx_range(struct bpf_perf_event_data, addr): 2067 bpf_ctx_record_field_size(info, size_u64); 2068 if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) 2069 return false; 2070 break; 2071 default: 2072 if (size != sizeof(long)) 2073 return false; 2074 } 2075 2076 return true; 2077 } 2078 2079 static u32 pe_prog_convert_ctx_access(enum bpf_access_type type, 2080 const struct bpf_insn *si, 2081 struct bpf_insn *insn_buf, 2082 struct bpf_prog *prog, u32 *target_size) 2083 { 2084 struct bpf_insn *insn = insn_buf; 2085 2086 switch (si->off) { 2087 case offsetof(struct bpf_perf_event_data, sample_period): 2088 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 2089 data), si->dst_reg, si->src_reg, 2090 offsetof(struct bpf_perf_event_data_kern, data)); 2091 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, 2092 bpf_target_off(struct perf_sample_data, period, 8, 2093 target_size)); 2094 break; 2095 case offsetof(struct bpf_perf_event_data, addr): 2096 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 2097 data), si->dst_reg, si->src_reg, 2098 offsetof(struct bpf_perf_event_data_kern, data)); 2099 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, 2100 bpf_target_off(struct perf_sample_data, addr, 8, 2101 target_size)); 2102 break; 2103 default: 2104 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 2105 regs), si->dst_reg, si->src_reg, 2106 offsetof(struct bpf_perf_event_data_kern, regs)); 2107 *insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg, 2108 si->off); 2109 break; 2110 } 2111 2112 return insn - insn_buf; 2113 } 2114 2115 const struct bpf_verifier_ops perf_event_verifier_ops = { 2116 .get_func_proto = pe_prog_func_proto, 2117 .is_valid_access = pe_prog_is_valid_access, 2118 .convert_ctx_access = pe_prog_convert_ctx_access, 2119 }; 2120 2121 const struct bpf_prog_ops perf_event_prog_ops = { 2122 }; 2123 2124 static DEFINE_MUTEX(bpf_event_mutex); 2125 2126 #define BPF_TRACE_MAX_PROGS 64 2127 2128 int perf_event_attach_bpf_prog(struct perf_event *event, 2129 struct bpf_prog *prog, 2130 u64 bpf_cookie) 2131 { 2132 struct bpf_prog_array *old_array; 2133 struct bpf_prog_array *new_array; 2134 int ret = -EEXIST; 2135 2136 /* 2137 * Kprobe override only works if they are on the function entry, 2138 * and only if they are on the opt-in list. 2139 */ 2140 if (prog->kprobe_override && 2141 (!trace_kprobe_on_func_entry(event->tp_event) || 2142 !trace_kprobe_error_injectable(event->tp_event))) 2143 return -EINVAL; 2144 2145 mutex_lock(&bpf_event_mutex); 2146 2147 if (event->prog) 2148 goto unlock; 2149 2150 old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); 2151 if (old_array && 2152 bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) { 2153 ret = -E2BIG; 2154 goto unlock; 2155 } 2156 2157 ret = bpf_prog_array_copy(old_array, NULL, prog, bpf_cookie, &new_array); 2158 if (ret < 0) 2159 goto unlock; 2160 2161 /* set the new array to event->tp_event and set event->prog */ 2162 event->prog = prog; 2163 event->bpf_cookie = bpf_cookie; 2164 rcu_assign_pointer(event->tp_event->prog_array, new_array); 2165 bpf_prog_array_free_sleepable(old_array); 2166 2167 unlock: 2168 mutex_unlock(&bpf_event_mutex); 2169 return ret; 2170 } 2171 2172 void perf_event_detach_bpf_prog(struct perf_event *event) 2173 { 2174 struct bpf_prog_array *old_array; 2175 struct bpf_prog_array *new_array; 2176 int ret; 2177 2178 mutex_lock(&bpf_event_mutex); 2179 2180 if (!event->prog) 2181 goto unlock; 2182 2183 old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); 2184 ret = bpf_prog_array_copy(old_array, event->prog, NULL, 0, &new_array); 2185 if (ret == -ENOENT) 2186 goto unlock; 2187 if (ret < 0) { 2188 bpf_prog_array_delete_safe(old_array, event->prog); 2189 } else { 2190 rcu_assign_pointer(event->tp_event->prog_array, new_array); 2191 bpf_prog_array_free_sleepable(old_array); 2192 } 2193 2194 bpf_prog_put(event->prog); 2195 event->prog = NULL; 2196 2197 unlock: 2198 mutex_unlock(&bpf_event_mutex); 2199 } 2200 2201 int perf_event_query_prog_array(struct perf_event *event, void __user *info) 2202 { 2203 struct perf_event_query_bpf __user *uquery = info; 2204 struct perf_event_query_bpf query = {}; 2205 struct bpf_prog_array *progs; 2206 u32 *ids, prog_cnt, ids_len; 2207 int ret; 2208 2209 if (!perfmon_capable()) 2210 return -EPERM; 2211 if (event->attr.type != PERF_TYPE_TRACEPOINT) 2212 return -EINVAL; 2213 if (copy_from_user(&query, uquery, sizeof(query))) 2214 return -EFAULT; 2215 2216 ids_len = query.ids_len; 2217 if (ids_len > BPF_TRACE_MAX_PROGS) 2218 return -E2BIG; 2219 ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN); 2220 if (!ids) 2221 return -ENOMEM; 2222 /* 2223 * The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which 2224 * is required when user only wants to check for uquery->prog_cnt. 2225 * There is no need to check for it since the case is handled 2226 * gracefully in bpf_prog_array_copy_info. 2227 */ 2228 2229 mutex_lock(&bpf_event_mutex); 2230 progs = bpf_event_rcu_dereference(event->tp_event->prog_array); 2231 ret = bpf_prog_array_copy_info(progs, ids, ids_len, &prog_cnt); 2232 mutex_unlock(&bpf_event_mutex); 2233 2234 if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) || 2235 copy_to_user(uquery->ids, ids, ids_len * sizeof(u32))) 2236 ret = -EFAULT; 2237 2238 kfree(ids); 2239 return ret; 2240 } 2241 2242 extern struct bpf_raw_event_map __start__bpf_raw_tp[]; 2243 extern struct bpf_raw_event_map __stop__bpf_raw_tp[]; 2244 2245 struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name) 2246 { 2247 struct bpf_raw_event_map *btp = __start__bpf_raw_tp; 2248 2249 for (; btp < __stop__bpf_raw_tp; btp++) { 2250 if (!strcmp(btp->tp->name, name)) 2251 return btp; 2252 } 2253 2254 return bpf_get_raw_tracepoint_module(name); 2255 } 2256 2257 void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp) 2258 { 2259 struct module *mod; 2260 2261 preempt_disable(); 2262 mod = __module_address((unsigned long)btp); 2263 module_put(mod); 2264 preempt_enable(); 2265 } 2266 2267 static __always_inline 2268 void __bpf_trace_run(struct bpf_prog *prog, u64 *args) 2269 { 2270 cant_sleep(); 2271 if (unlikely(this_cpu_inc_return(*(prog->active)) != 1)) { 2272 bpf_prog_inc_misses_counter(prog); 2273 goto out; 2274 } 2275 rcu_read_lock(); 2276 (void) bpf_prog_run(prog, args); 2277 rcu_read_unlock(); 2278 out: 2279 this_cpu_dec(*(prog->active)); 2280 } 2281 2282 #define UNPACK(...) __VA_ARGS__ 2283 #define REPEAT_1(FN, DL, X, ...) FN(X) 2284 #define REPEAT_2(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__) 2285 #define REPEAT_3(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_2(FN, DL, __VA_ARGS__) 2286 #define REPEAT_4(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_3(FN, DL, __VA_ARGS__) 2287 #define REPEAT_5(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_4(FN, DL, __VA_ARGS__) 2288 #define REPEAT_6(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_5(FN, DL, __VA_ARGS__) 2289 #define REPEAT_7(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_6(FN, DL, __VA_ARGS__) 2290 #define REPEAT_8(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_7(FN, DL, __VA_ARGS__) 2291 #define REPEAT_9(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_8(FN, DL, __VA_ARGS__) 2292 #define REPEAT_10(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_9(FN, DL, __VA_ARGS__) 2293 #define REPEAT_11(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_10(FN, DL, __VA_ARGS__) 2294 #define REPEAT_12(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_11(FN, DL, __VA_ARGS__) 2295 #define REPEAT(X, FN, DL, ...) REPEAT_##X(FN, DL, __VA_ARGS__) 2296 2297 #define SARG(X) u64 arg##X 2298 #define COPY(X) args[X] = arg##X 2299 2300 #define __DL_COM (,) 2301 #define __DL_SEM (;) 2302 2303 #define __SEQ_0_11 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 2304 2305 #define BPF_TRACE_DEFN_x(x) \ 2306 void bpf_trace_run##x(struct bpf_prog *prog, \ 2307 REPEAT(x, SARG, __DL_COM, __SEQ_0_11)) \ 2308 { \ 2309 u64 args[x]; \ 2310 REPEAT(x, COPY, __DL_SEM, __SEQ_0_11); \ 2311 __bpf_trace_run(prog, args); \ 2312 } \ 2313 EXPORT_SYMBOL_GPL(bpf_trace_run##x) 2314 BPF_TRACE_DEFN_x(1); 2315 BPF_TRACE_DEFN_x(2); 2316 BPF_TRACE_DEFN_x(3); 2317 BPF_TRACE_DEFN_x(4); 2318 BPF_TRACE_DEFN_x(5); 2319 BPF_TRACE_DEFN_x(6); 2320 BPF_TRACE_DEFN_x(7); 2321 BPF_TRACE_DEFN_x(8); 2322 BPF_TRACE_DEFN_x(9); 2323 BPF_TRACE_DEFN_x(10); 2324 BPF_TRACE_DEFN_x(11); 2325 BPF_TRACE_DEFN_x(12); 2326 2327 static int __bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog) 2328 { 2329 struct tracepoint *tp = btp->tp; 2330 2331 /* 2332 * check that program doesn't access arguments beyond what's 2333 * available in this tracepoint 2334 */ 2335 if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64)) 2336 return -EINVAL; 2337 2338 if (prog->aux->max_tp_access > btp->writable_size) 2339 return -EINVAL; 2340 2341 return tracepoint_probe_register_may_exist(tp, (void *)btp->bpf_func, 2342 prog); 2343 } 2344 2345 int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog) 2346 { 2347 return __bpf_probe_register(btp, prog); 2348 } 2349 2350 int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_prog *prog) 2351 { 2352 return tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, prog); 2353 } 2354 2355 int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id, 2356 u32 *fd_type, const char **buf, 2357 u64 *probe_offset, u64 *probe_addr) 2358 { 2359 bool is_tracepoint, is_syscall_tp; 2360 struct bpf_prog *prog; 2361 int flags, err = 0; 2362 2363 prog = event->prog; 2364 if (!prog) 2365 return -ENOENT; 2366 2367 /* not supporting BPF_PROG_TYPE_PERF_EVENT yet */ 2368 if (prog->type == BPF_PROG_TYPE_PERF_EVENT) 2369 return -EOPNOTSUPP; 2370 2371 *prog_id = prog->aux->id; 2372 flags = event->tp_event->flags; 2373 is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT; 2374 is_syscall_tp = is_syscall_trace_event(event->tp_event); 2375 2376 if (is_tracepoint || is_syscall_tp) { 2377 *buf = is_tracepoint ? event->tp_event->tp->name 2378 : event->tp_event->name; 2379 *fd_type = BPF_FD_TYPE_TRACEPOINT; 2380 *probe_offset = 0x0; 2381 *probe_addr = 0x0; 2382 } else { 2383 /* kprobe/uprobe */ 2384 err = -EOPNOTSUPP; 2385 #ifdef CONFIG_KPROBE_EVENTS 2386 if (flags & TRACE_EVENT_FL_KPROBE) 2387 err = bpf_get_kprobe_info(event, fd_type, buf, 2388 probe_offset, probe_addr, 2389 event->attr.type == PERF_TYPE_TRACEPOINT); 2390 #endif 2391 #ifdef CONFIG_UPROBE_EVENTS 2392 if (flags & TRACE_EVENT_FL_UPROBE) 2393 err = bpf_get_uprobe_info(event, fd_type, buf, 2394 probe_offset, 2395 event->attr.type == PERF_TYPE_TRACEPOINT); 2396 #endif 2397 } 2398 2399 return err; 2400 } 2401 2402 static int __init send_signal_irq_work_init(void) 2403 { 2404 int cpu; 2405 struct send_signal_irq_work *work; 2406 2407 for_each_possible_cpu(cpu) { 2408 work = per_cpu_ptr(&send_signal_work, cpu); 2409 init_irq_work(&work->irq_work, do_bpf_send_signal); 2410 } 2411 return 0; 2412 } 2413 2414 subsys_initcall(send_signal_irq_work_init); 2415 2416 #ifdef CONFIG_MODULES 2417 static int bpf_event_notify(struct notifier_block *nb, unsigned long op, 2418 void *module) 2419 { 2420 struct bpf_trace_module *btm, *tmp; 2421 struct module *mod = module; 2422 int ret = 0; 2423 2424 if (mod->num_bpf_raw_events == 0 || 2425 (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING)) 2426 goto out; 2427 2428 mutex_lock(&bpf_module_mutex); 2429 2430 switch (op) { 2431 case MODULE_STATE_COMING: 2432 btm = kzalloc(sizeof(*btm), GFP_KERNEL); 2433 if (btm) { 2434 btm->module = module; 2435 list_add(&btm->list, &bpf_trace_modules); 2436 } else { 2437 ret = -ENOMEM; 2438 } 2439 break; 2440 case MODULE_STATE_GOING: 2441 list_for_each_entry_safe(btm, tmp, &bpf_trace_modules, list) { 2442 if (btm->module == module) { 2443 list_del(&btm->list); 2444 kfree(btm); 2445 break; 2446 } 2447 } 2448 break; 2449 } 2450 2451 mutex_unlock(&bpf_module_mutex); 2452 2453 out: 2454 return notifier_from_errno(ret); 2455 } 2456 2457 static struct notifier_block bpf_module_nb = { 2458 .notifier_call = bpf_event_notify, 2459 }; 2460 2461 static int __init bpf_event_init(void) 2462 { 2463 register_module_notifier(&bpf_module_nb); 2464 return 0; 2465 } 2466 2467 fs_initcall(bpf_event_init); 2468 #endif /* CONFIG_MODULES */ 2469 2470 #ifdef CONFIG_FPROBE 2471 struct bpf_kprobe_multi_link { 2472 struct bpf_link link; 2473 struct fprobe fp; 2474 unsigned long *addrs; 2475 u64 *cookies; 2476 u32 cnt; 2477 u32 mods_cnt; 2478 struct module **mods; 2479 }; 2480 2481 struct bpf_kprobe_multi_run_ctx { 2482 struct bpf_run_ctx run_ctx; 2483 struct bpf_kprobe_multi_link *link; 2484 unsigned long entry_ip; 2485 }; 2486 2487 struct user_syms { 2488 const char **syms; 2489 char *buf; 2490 }; 2491 2492 static int copy_user_syms(struct user_syms *us, unsigned long __user *usyms, u32 cnt) 2493 { 2494 unsigned long __user usymbol; 2495 const char **syms = NULL; 2496 char *buf = NULL, *p; 2497 int err = -ENOMEM; 2498 unsigned int i; 2499 2500 syms = kvmalloc_array(cnt, sizeof(*syms), GFP_KERNEL); 2501 if (!syms) 2502 goto error; 2503 2504 buf = kvmalloc_array(cnt, KSYM_NAME_LEN, GFP_KERNEL); 2505 if (!buf) 2506 goto error; 2507 2508 for (p = buf, i = 0; i < cnt; i++) { 2509 if (__get_user(usymbol, usyms + i)) { 2510 err = -EFAULT; 2511 goto error; 2512 } 2513 err = strncpy_from_user(p, (const char __user *) usymbol, KSYM_NAME_LEN); 2514 if (err == KSYM_NAME_LEN) 2515 err = -E2BIG; 2516 if (err < 0) 2517 goto error; 2518 syms[i] = p; 2519 p += err + 1; 2520 } 2521 2522 us->syms = syms; 2523 us->buf = buf; 2524 return 0; 2525 2526 error: 2527 if (err) { 2528 kvfree(syms); 2529 kvfree(buf); 2530 } 2531 return err; 2532 } 2533 2534 static void kprobe_multi_put_modules(struct module **mods, u32 cnt) 2535 { 2536 u32 i; 2537 2538 for (i = 0; i < cnt; i++) 2539 module_put(mods[i]); 2540 } 2541 2542 static void free_user_syms(struct user_syms *us) 2543 { 2544 kvfree(us->syms); 2545 kvfree(us->buf); 2546 } 2547 2548 static void bpf_kprobe_multi_link_release(struct bpf_link *link) 2549 { 2550 struct bpf_kprobe_multi_link *kmulti_link; 2551 2552 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); 2553 unregister_fprobe(&kmulti_link->fp); 2554 kprobe_multi_put_modules(kmulti_link->mods, kmulti_link->mods_cnt); 2555 } 2556 2557 static void bpf_kprobe_multi_link_dealloc(struct bpf_link *link) 2558 { 2559 struct bpf_kprobe_multi_link *kmulti_link; 2560 2561 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); 2562 kvfree(kmulti_link->addrs); 2563 kvfree(kmulti_link->cookies); 2564 kfree(kmulti_link->mods); 2565 kfree(kmulti_link); 2566 } 2567 2568 static const struct bpf_link_ops bpf_kprobe_multi_link_lops = { 2569 .release = bpf_kprobe_multi_link_release, 2570 .dealloc = bpf_kprobe_multi_link_dealloc, 2571 }; 2572 2573 static void bpf_kprobe_multi_cookie_swap(void *a, void *b, int size, const void *priv) 2574 { 2575 const struct bpf_kprobe_multi_link *link = priv; 2576 unsigned long *addr_a = a, *addr_b = b; 2577 u64 *cookie_a, *cookie_b; 2578 2579 cookie_a = link->cookies + (addr_a - link->addrs); 2580 cookie_b = link->cookies + (addr_b - link->addrs); 2581 2582 /* swap addr_a/addr_b and cookie_a/cookie_b values */ 2583 swap(*addr_a, *addr_b); 2584 swap(*cookie_a, *cookie_b); 2585 } 2586 2587 static int bpf_kprobe_multi_addrs_cmp(const void *a, const void *b) 2588 { 2589 const unsigned long *addr_a = a, *addr_b = b; 2590 2591 if (*addr_a == *addr_b) 2592 return 0; 2593 return *addr_a < *addr_b ? -1 : 1; 2594 } 2595 2596 static int bpf_kprobe_multi_cookie_cmp(const void *a, const void *b, const void *priv) 2597 { 2598 return bpf_kprobe_multi_addrs_cmp(a, b); 2599 } 2600 2601 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx) 2602 { 2603 struct bpf_kprobe_multi_run_ctx *run_ctx; 2604 struct bpf_kprobe_multi_link *link; 2605 u64 *cookie, entry_ip; 2606 unsigned long *addr; 2607 2608 if (WARN_ON_ONCE(!ctx)) 2609 return 0; 2610 run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, run_ctx); 2611 link = run_ctx->link; 2612 if (!link->cookies) 2613 return 0; 2614 entry_ip = run_ctx->entry_ip; 2615 addr = bsearch(&entry_ip, link->addrs, link->cnt, sizeof(entry_ip), 2616 bpf_kprobe_multi_addrs_cmp); 2617 if (!addr) 2618 return 0; 2619 cookie = link->cookies + (addr - link->addrs); 2620 return *cookie; 2621 } 2622 2623 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 2624 { 2625 struct bpf_kprobe_multi_run_ctx *run_ctx; 2626 2627 run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, run_ctx); 2628 return run_ctx->entry_ip; 2629 } 2630 2631 static int 2632 kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link, 2633 unsigned long entry_ip, struct pt_regs *regs) 2634 { 2635 struct bpf_kprobe_multi_run_ctx run_ctx = { 2636 .link = link, 2637 .entry_ip = entry_ip, 2638 }; 2639 struct bpf_run_ctx *old_run_ctx; 2640 int err; 2641 2642 if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) { 2643 err = 0; 2644 goto out; 2645 } 2646 2647 migrate_disable(); 2648 rcu_read_lock(); 2649 old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx); 2650 err = bpf_prog_run(link->link.prog, regs); 2651 bpf_reset_run_ctx(old_run_ctx); 2652 rcu_read_unlock(); 2653 migrate_enable(); 2654 2655 out: 2656 __this_cpu_dec(bpf_prog_active); 2657 return err; 2658 } 2659 2660 static int 2661 kprobe_multi_link_handler(struct fprobe *fp, unsigned long fentry_ip, 2662 unsigned long ret_ip, struct pt_regs *regs, 2663 void *data) 2664 { 2665 struct bpf_kprobe_multi_link *link; 2666 2667 link = container_of(fp, struct bpf_kprobe_multi_link, fp); 2668 kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), regs); 2669 return 0; 2670 } 2671 2672 static void 2673 kprobe_multi_link_exit_handler(struct fprobe *fp, unsigned long fentry_ip, 2674 unsigned long ret_ip, struct pt_regs *regs, 2675 void *data) 2676 { 2677 struct bpf_kprobe_multi_link *link; 2678 2679 link = container_of(fp, struct bpf_kprobe_multi_link, fp); 2680 kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), regs); 2681 } 2682 2683 static int symbols_cmp_r(const void *a, const void *b, const void *priv) 2684 { 2685 const char **str_a = (const char **) a; 2686 const char **str_b = (const char **) b; 2687 2688 return strcmp(*str_a, *str_b); 2689 } 2690 2691 struct multi_symbols_sort { 2692 const char **funcs; 2693 u64 *cookies; 2694 }; 2695 2696 static void symbols_swap_r(void *a, void *b, int size, const void *priv) 2697 { 2698 const struct multi_symbols_sort *data = priv; 2699 const char **name_a = a, **name_b = b; 2700 2701 swap(*name_a, *name_b); 2702 2703 /* If defined, swap also related cookies. */ 2704 if (data->cookies) { 2705 u64 *cookie_a, *cookie_b; 2706 2707 cookie_a = data->cookies + (name_a - data->funcs); 2708 cookie_b = data->cookies + (name_b - data->funcs); 2709 swap(*cookie_a, *cookie_b); 2710 } 2711 } 2712 2713 struct modules_array { 2714 struct module **mods; 2715 int mods_cnt; 2716 int mods_cap; 2717 }; 2718 2719 static int add_module(struct modules_array *arr, struct module *mod) 2720 { 2721 struct module **mods; 2722 2723 if (arr->mods_cnt == arr->mods_cap) { 2724 arr->mods_cap = max(16, arr->mods_cap * 3 / 2); 2725 mods = krealloc_array(arr->mods, arr->mods_cap, sizeof(*mods), GFP_KERNEL); 2726 if (!mods) 2727 return -ENOMEM; 2728 arr->mods = mods; 2729 } 2730 2731 arr->mods[arr->mods_cnt] = mod; 2732 arr->mods_cnt++; 2733 return 0; 2734 } 2735 2736 static bool has_module(struct modules_array *arr, struct module *mod) 2737 { 2738 int i; 2739 2740 for (i = arr->mods_cnt - 1; i >= 0; i--) { 2741 if (arr->mods[i] == mod) 2742 return true; 2743 } 2744 return false; 2745 } 2746 2747 static int get_modules_for_addrs(struct module ***mods, unsigned long *addrs, u32 addrs_cnt) 2748 { 2749 struct modules_array arr = {}; 2750 u32 i, err = 0; 2751 2752 for (i = 0; i < addrs_cnt; i++) { 2753 struct module *mod; 2754 2755 preempt_disable(); 2756 mod = __module_address(addrs[i]); 2757 /* Either no module or we it's already stored */ 2758 if (!mod || has_module(&arr, mod)) { 2759 preempt_enable(); 2760 continue; 2761 } 2762 if (!try_module_get(mod)) 2763 err = -EINVAL; 2764 preempt_enable(); 2765 if (err) 2766 break; 2767 err = add_module(&arr, mod); 2768 if (err) { 2769 module_put(mod); 2770 break; 2771 } 2772 } 2773 2774 /* We return either err < 0 in case of error, ... */ 2775 if (err) { 2776 kprobe_multi_put_modules(arr.mods, arr.mods_cnt); 2777 kfree(arr.mods); 2778 return err; 2779 } 2780 2781 /* or number of modules found if everything is ok. */ 2782 *mods = arr.mods; 2783 return arr.mods_cnt; 2784 } 2785 2786 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 2787 { 2788 struct bpf_kprobe_multi_link *link = NULL; 2789 struct bpf_link_primer link_primer; 2790 void __user *ucookies; 2791 unsigned long *addrs; 2792 u32 flags, cnt, size; 2793 void __user *uaddrs; 2794 u64 *cookies = NULL; 2795 void __user *usyms; 2796 int err; 2797 2798 /* no support for 32bit archs yet */ 2799 if (sizeof(u64) != sizeof(void *)) 2800 return -EOPNOTSUPP; 2801 2802 if (prog->expected_attach_type != BPF_TRACE_KPROBE_MULTI) 2803 return -EINVAL; 2804 2805 flags = attr->link_create.kprobe_multi.flags; 2806 if (flags & ~BPF_F_KPROBE_MULTI_RETURN) 2807 return -EINVAL; 2808 2809 uaddrs = u64_to_user_ptr(attr->link_create.kprobe_multi.addrs); 2810 usyms = u64_to_user_ptr(attr->link_create.kprobe_multi.syms); 2811 if (!!uaddrs == !!usyms) 2812 return -EINVAL; 2813 2814 cnt = attr->link_create.kprobe_multi.cnt; 2815 if (!cnt) 2816 return -EINVAL; 2817 2818 size = cnt * sizeof(*addrs); 2819 addrs = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL); 2820 if (!addrs) 2821 return -ENOMEM; 2822 2823 ucookies = u64_to_user_ptr(attr->link_create.kprobe_multi.cookies); 2824 if (ucookies) { 2825 cookies = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL); 2826 if (!cookies) { 2827 err = -ENOMEM; 2828 goto error; 2829 } 2830 if (copy_from_user(cookies, ucookies, size)) { 2831 err = -EFAULT; 2832 goto error; 2833 } 2834 } 2835 2836 if (uaddrs) { 2837 if (copy_from_user(addrs, uaddrs, size)) { 2838 err = -EFAULT; 2839 goto error; 2840 } 2841 } else { 2842 struct multi_symbols_sort data = { 2843 .cookies = cookies, 2844 }; 2845 struct user_syms us; 2846 2847 err = copy_user_syms(&us, usyms, cnt); 2848 if (err) 2849 goto error; 2850 2851 if (cookies) 2852 data.funcs = us.syms; 2853 2854 sort_r(us.syms, cnt, sizeof(*us.syms), symbols_cmp_r, 2855 symbols_swap_r, &data); 2856 2857 err = ftrace_lookup_symbols(us.syms, cnt, addrs); 2858 free_user_syms(&us); 2859 if (err) 2860 goto error; 2861 } 2862 2863 link = kzalloc(sizeof(*link), GFP_KERNEL); 2864 if (!link) { 2865 err = -ENOMEM; 2866 goto error; 2867 } 2868 2869 bpf_link_init(&link->link, BPF_LINK_TYPE_KPROBE_MULTI, 2870 &bpf_kprobe_multi_link_lops, prog); 2871 2872 err = bpf_link_prime(&link->link, &link_primer); 2873 if (err) 2874 goto error; 2875 2876 if (flags & BPF_F_KPROBE_MULTI_RETURN) 2877 link->fp.exit_handler = kprobe_multi_link_exit_handler; 2878 else 2879 link->fp.entry_handler = kprobe_multi_link_handler; 2880 2881 link->addrs = addrs; 2882 link->cookies = cookies; 2883 link->cnt = cnt; 2884 2885 if (cookies) { 2886 /* 2887 * Sorting addresses will trigger sorting cookies as well 2888 * (check bpf_kprobe_multi_cookie_swap). This way we can 2889 * find cookie based on the address in bpf_get_attach_cookie 2890 * helper. 2891 */ 2892 sort_r(addrs, cnt, sizeof(*addrs), 2893 bpf_kprobe_multi_cookie_cmp, 2894 bpf_kprobe_multi_cookie_swap, 2895 link); 2896 } 2897 2898 err = get_modules_for_addrs(&link->mods, addrs, cnt); 2899 if (err < 0) { 2900 bpf_link_cleanup(&link_primer); 2901 return err; 2902 } 2903 link->mods_cnt = err; 2904 2905 err = register_fprobe_ips(&link->fp, addrs, cnt); 2906 if (err) { 2907 kprobe_multi_put_modules(link->mods, link->mods_cnt); 2908 bpf_link_cleanup(&link_primer); 2909 return err; 2910 } 2911 2912 return bpf_link_settle(&link_primer); 2913 2914 error: 2915 kfree(link); 2916 kvfree(addrs); 2917 kvfree(cookies); 2918 return err; 2919 } 2920 #else /* !CONFIG_FPROBE */ 2921 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 2922 { 2923 return -EOPNOTSUPP; 2924 } 2925 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx) 2926 { 2927 return 0; 2928 } 2929 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 2930 { 2931 return 0; 2932 } 2933 #endif 2934