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 = this_cpu_ptr(&bpf_trace_sds); 665 int nest_level = this_cpu_inc_return(bpf_trace_nest_level); 666 struct perf_raw_record raw = { 667 .frag = { 668 .size = size, 669 .data = data, 670 }, 671 }; 672 struct perf_sample_data *sd; 673 int err; 674 675 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(sds->sds))) { 676 err = -EBUSY; 677 goto out; 678 } 679 680 sd = &sds->sds[nest_level - 1]; 681 682 if (unlikely(flags & ~(BPF_F_INDEX_MASK))) { 683 err = -EINVAL; 684 goto out; 685 } 686 687 perf_sample_data_init(sd, 0, 0); 688 perf_sample_save_raw_data(sd, &raw); 689 690 err = __bpf_perf_event_output(regs, map, flags, sd); 691 692 out: 693 this_cpu_dec(bpf_trace_nest_level); 694 return err; 695 } 696 697 static const struct bpf_func_proto bpf_perf_event_output_proto = { 698 .func = bpf_perf_event_output, 699 .gpl_only = true, 700 .ret_type = RET_INTEGER, 701 .arg1_type = ARG_PTR_TO_CTX, 702 .arg2_type = ARG_CONST_MAP_PTR, 703 .arg3_type = ARG_ANYTHING, 704 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, 705 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 706 }; 707 708 static DEFINE_PER_CPU(int, bpf_event_output_nest_level); 709 struct bpf_nested_pt_regs { 710 struct pt_regs regs[3]; 711 }; 712 static DEFINE_PER_CPU(struct bpf_nested_pt_regs, bpf_pt_regs); 713 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_misc_sds); 714 715 u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size, 716 void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy) 717 { 718 int nest_level = this_cpu_inc_return(bpf_event_output_nest_level); 719 struct perf_raw_frag frag = { 720 .copy = ctx_copy, 721 .size = ctx_size, 722 .data = ctx, 723 }; 724 struct perf_raw_record raw = { 725 .frag = { 726 { 727 .next = ctx_size ? &frag : NULL, 728 }, 729 .size = meta_size, 730 .data = meta, 731 }, 732 }; 733 struct perf_sample_data *sd; 734 struct pt_regs *regs; 735 u64 ret; 736 737 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(bpf_misc_sds.sds))) { 738 ret = -EBUSY; 739 goto out; 740 } 741 sd = this_cpu_ptr(&bpf_misc_sds.sds[nest_level - 1]); 742 regs = this_cpu_ptr(&bpf_pt_regs.regs[nest_level - 1]); 743 744 perf_fetch_caller_regs(regs); 745 perf_sample_data_init(sd, 0, 0); 746 perf_sample_save_raw_data(sd, &raw); 747 748 ret = __bpf_perf_event_output(regs, map, flags, sd); 749 out: 750 this_cpu_dec(bpf_event_output_nest_level); 751 return ret; 752 } 753 754 BPF_CALL_0(bpf_get_current_task) 755 { 756 return (long) current; 757 } 758 759 const struct bpf_func_proto bpf_get_current_task_proto = { 760 .func = bpf_get_current_task, 761 .gpl_only = true, 762 .ret_type = RET_INTEGER, 763 }; 764 765 BPF_CALL_0(bpf_get_current_task_btf) 766 { 767 return (unsigned long) current; 768 } 769 770 const struct bpf_func_proto bpf_get_current_task_btf_proto = { 771 .func = bpf_get_current_task_btf, 772 .gpl_only = true, 773 .ret_type = RET_PTR_TO_BTF_ID_TRUSTED, 774 .ret_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK], 775 }; 776 777 BPF_CALL_1(bpf_task_pt_regs, struct task_struct *, task) 778 { 779 return (unsigned long) task_pt_regs(task); 780 } 781 782 BTF_ID_LIST(bpf_task_pt_regs_ids) 783 BTF_ID(struct, pt_regs) 784 785 const struct bpf_func_proto bpf_task_pt_regs_proto = { 786 .func = bpf_task_pt_regs, 787 .gpl_only = true, 788 .arg1_type = ARG_PTR_TO_BTF_ID, 789 .arg1_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK], 790 .ret_type = RET_PTR_TO_BTF_ID, 791 .ret_btf_id = &bpf_task_pt_regs_ids[0], 792 }; 793 794 BPF_CALL_2(bpf_current_task_under_cgroup, struct bpf_map *, map, u32, idx) 795 { 796 struct bpf_array *array = container_of(map, struct bpf_array, map); 797 struct cgroup *cgrp; 798 799 if (unlikely(idx >= array->map.max_entries)) 800 return -E2BIG; 801 802 cgrp = READ_ONCE(array->ptrs[idx]); 803 if (unlikely(!cgrp)) 804 return -EAGAIN; 805 806 return task_under_cgroup_hierarchy(current, cgrp); 807 } 808 809 static const struct bpf_func_proto bpf_current_task_under_cgroup_proto = { 810 .func = bpf_current_task_under_cgroup, 811 .gpl_only = false, 812 .ret_type = RET_INTEGER, 813 .arg1_type = ARG_CONST_MAP_PTR, 814 .arg2_type = ARG_ANYTHING, 815 }; 816 817 struct send_signal_irq_work { 818 struct irq_work irq_work; 819 struct task_struct *task; 820 u32 sig; 821 enum pid_type type; 822 }; 823 824 static DEFINE_PER_CPU(struct send_signal_irq_work, send_signal_work); 825 826 static void do_bpf_send_signal(struct irq_work *entry) 827 { 828 struct send_signal_irq_work *work; 829 830 work = container_of(entry, struct send_signal_irq_work, irq_work); 831 group_send_sig_info(work->sig, SEND_SIG_PRIV, work->task, work->type); 832 put_task_struct(work->task); 833 } 834 835 static int bpf_send_signal_common(u32 sig, enum pid_type type) 836 { 837 struct send_signal_irq_work *work = NULL; 838 839 /* Similar to bpf_probe_write_user, task needs to be 840 * in a sound condition and kernel memory access be 841 * permitted in order to send signal to the current 842 * task. 843 */ 844 if (unlikely(current->flags & (PF_KTHREAD | PF_EXITING))) 845 return -EPERM; 846 if (unlikely(!nmi_uaccess_okay())) 847 return -EPERM; 848 /* Task should not be pid=1 to avoid kernel panic. */ 849 if (unlikely(is_global_init(current))) 850 return -EPERM; 851 852 if (irqs_disabled()) { 853 /* Do an early check on signal validity. Otherwise, 854 * the error is lost in deferred irq_work. 855 */ 856 if (unlikely(!valid_signal(sig))) 857 return -EINVAL; 858 859 work = this_cpu_ptr(&send_signal_work); 860 if (irq_work_is_busy(&work->irq_work)) 861 return -EBUSY; 862 863 /* Add the current task, which is the target of sending signal, 864 * to the irq_work. The current task may change when queued 865 * irq works get executed. 866 */ 867 work->task = get_task_struct(current); 868 work->sig = sig; 869 work->type = type; 870 irq_work_queue(&work->irq_work); 871 return 0; 872 } 873 874 return group_send_sig_info(sig, SEND_SIG_PRIV, current, type); 875 } 876 877 BPF_CALL_1(bpf_send_signal, u32, sig) 878 { 879 return bpf_send_signal_common(sig, PIDTYPE_TGID); 880 } 881 882 static const struct bpf_func_proto bpf_send_signal_proto = { 883 .func = bpf_send_signal, 884 .gpl_only = false, 885 .ret_type = RET_INTEGER, 886 .arg1_type = ARG_ANYTHING, 887 }; 888 889 BPF_CALL_1(bpf_send_signal_thread, u32, sig) 890 { 891 return bpf_send_signal_common(sig, PIDTYPE_PID); 892 } 893 894 static const struct bpf_func_proto bpf_send_signal_thread_proto = { 895 .func = bpf_send_signal_thread, 896 .gpl_only = false, 897 .ret_type = RET_INTEGER, 898 .arg1_type = ARG_ANYTHING, 899 }; 900 901 BPF_CALL_3(bpf_d_path, struct path *, path, char *, buf, u32, sz) 902 { 903 long len; 904 char *p; 905 906 if (!sz) 907 return 0; 908 909 p = d_path(path, buf, sz); 910 if (IS_ERR(p)) { 911 len = PTR_ERR(p); 912 } else { 913 len = buf + sz - p; 914 memmove(buf, p, len); 915 } 916 917 return len; 918 } 919 920 BTF_SET_START(btf_allowlist_d_path) 921 #ifdef CONFIG_SECURITY 922 BTF_ID(func, security_file_permission) 923 BTF_ID(func, security_inode_getattr) 924 BTF_ID(func, security_file_open) 925 #endif 926 #ifdef CONFIG_SECURITY_PATH 927 BTF_ID(func, security_path_truncate) 928 #endif 929 BTF_ID(func, vfs_truncate) 930 BTF_ID(func, vfs_fallocate) 931 BTF_ID(func, dentry_open) 932 BTF_ID(func, vfs_getattr) 933 BTF_ID(func, filp_close) 934 BTF_SET_END(btf_allowlist_d_path) 935 936 static bool bpf_d_path_allowed(const struct bpf_prog *prog) 937 { 938 if (prog->type == BPF_PROG_TYPE_TRACING && 939 prog->expected_attach_type == BPF_TRACE_ITER) 940 return true; 941 942 if (prog->type == BPF_PROG_TYPE_LSM) 943 return bpf_lsm_is_sleepable_hook(prog->aux->attach_btf_id); 944 945 return btf_id_set_contains(&btf_allowlist_d_path, 946 prog->aux->attach_btf_id); 947 } 948 949 BTF_ID_LIST_SINGLE(bpf_d_path_btf_ids, struct, path) 950 951 static const struct bpf_func_proto bpf_d_path_proto = { 952 .func = bpf_d_path, 953 .gpl_only = false, 954 .ret_type = RET_INTEGER, 955 .arg1_type = ARG_PTR_TO_BTF_ID, 956 .arg1_btf_id = &bpf_d_path_btf_ids[0], 957 .arg2_type = ARG_PTR_TO_MEM, 958 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 959 .allowed = bpf_d_path_allowed, 960 }; 961 962 #define BTF_F_ALL (BTF_F_COMPACT | BTF_F_NONAME | \ 963 BTF_F_PTR_RAW | BTF_F_ZERO) 964 965 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size, 966 u64 flags, const struct btf **btf, 967 s32 *btf_id) 968 { 969 const struct btf_type *t; 970 971 if (unlikely(flags & ~(BTF_F_ALL))) 972 return -EINVAL; 973 974 if (btf_ptr_size != sizeof(struct btf_ptr)) 975 return -EINVAL; 976 977 *btf = bpf_get_btf_vmlinux(); 978 979 if (IS_ERR_OR_NULL(*btf)) 980 return IS_ERR(*btf) ? PTR_ERR(*btf) : -EINVAL; 981 982 if (ptr->type_id > 0) 983 *btf_id = ptr->type_id; 984 else 985 return -EINVAL; 986 987 if (*btf_id > 0) 988 t = btf_type_by_id(*btf, *btf_id); 989 if (*btf_id <= 0 || !t) 990 return -ENOENT; 991 992 return 0; 993 } 994 995 BPF_CALL_5(bpf_snprintf_btf, char *, str, u32, str_size, struct btf_ptr *, ptr, 996 u32, btf_ptr_size, u64, flags) 997 { 998 const struct btf *btf; 999 s32 btf_id; 1000 int ret; 1001 1002 ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id); 1003 if (ret) 1004 return ret; 1005 1006 return btf_type_snprintf_show(btf, btf_id, ptr->ptr, str, str_size, 1007 flags); 1008 } 1009 1010 const struct bpf_func_proto bpf_snprintf_btf_proto = { 1011 .func = bpf_snprintf_btf, 1012 .gpl_only = false, 1013 .ret_type = RET_INTEGER, 1014 .arg1_type = ARG_PTR_TO_MEM, 1015 .arg2_type = ARG_CONST_SIZE, 1016 .arg3_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1017 .arg4_type = ARG_CONST_SIZE, 1018 .arg5_type = ARG_ANYTHING, 1019 }; 1020 1021 BPF_CALL_1(bpf_get_func_ip_tracing, void *, ctx) 1022 { 1023 /* This helper call is inlined by verifier. */ 1024 return ((u64 *)ctx)[-2]; 1025 } 1026 1027 static const struct bpf_func_proto bpf_get_func_ip_proto_tracing = { 1028 .func = bpf_get_func_ip_tracing, 1029 .gpl_only = true, 1030 .ret_type = RET_INTEGER, 1031 .arg1_type = ARG_PTR_TO_CTX, 1032 }; 1033 1034 #ifdef CONFIG_X86_KERNEL_IBT 1035 static unsigned long get_entry_ip(unsigned long fentry_ip) 1036 { 1037 u32 instr; 1038 1039 /* Being extra safe in here in case entry ip is on the page-edge. */ 1040 if (get_kernel_nofault(instr, (u32 *) fentry_ip - 1)) 1041 return fentry_ip; 1042 if (is_endbr(instr)) 1043 fentry_ip -= ENDBR_INSN_SIZE; 1044 return fentry_ip; 1045 } 1046 #else 1047 #define get_entry_ip(fentry_ip) fentry_ip 1048 #endif 1049 1050 BPF_CALL_1(bpf_get_func_ip_kprobe, struct pt_regs *, regs) 1051 { 1052 struct kprobe *kp = kprobe_running(); 1053 1054 if (!kp || !(kp->flags & KPROBE_FLAG_ON_FUNC_ENTRY)) 1055 return 0; 1056 1057 return get_entry_ip((uintptr_t)kp->addr); 1058 } 1059 1060 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe = { 1061 .func = bpf_get_func_ip_kprobe, 1062 .gpl_only = true, 1063 .ret_type = RET_INTEGER, 1064 .arg1_type = ARG_PTR_TO_CTX, 1065 }; 1066 1067 BPF_CALL_1(bpf_get_func_ip_kprobe_multi, struct pt_regs *, regs) 1068 { 1069 return bpf_kprobe_multi_entry_ip(current->bpf_ctx); 1070 } 1071 1072 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe_multi = { 1073 .func = bpf_get_func_ip_kprobe_multi, 1074 .gpl_only = false, 1075 .ret_type = RET_INTEGER, 1076 .arg1_type = ARG_PTR_TO_CTX, 1077 }; 1078 1079 BPF_CALL_1(bpf_get_attach_cookie_kprobe_multi, struct pt_regs *, regs) 1080 { 1081 return bpf_kprobe_multi_cookie(current->bpf_ctx); 1082 } 1083 1084 static const struct bpf_func_proto bpf_get_attach_cookie_proto_kmulti = { 1085 .func = bpf_get_attach_cookie_kprobe_multi, 1086 .gpl_only = false, 1087 .ret_type = RET_INTEGER, 1088 .arg1_type = ARG_PTR_TO_CTX, 1089 }; 1090 1091 BPF_CALL_1(bpf_get_attach_cookie_trace, void *, ctx) 1092 { 1093 struct bpf_trace_run_ctx *run_ctx; 1094 1095 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); 1096 return run_ctx->bpf_cookie; 1097 } 1098 1099 static const struct bpf_func_proto bpf_get_attach_cookie_proto_trace = { 1100 .func = bpf_get_attach_cookie_trace, 1101 .gpl_only = false, 1102 .ret_type = RET_INTEGER, 1103 .arg1_type = ARG_PTR_TO_CTX, 1104 }; 1105 1106 BPF_CALL_1(bpf_get_attach_cookie_pe, struct bpf_perf_event_data_kern *, ctx) 1107 { 1108 return ctx->event->bpf_cookie; 1109 } 1110 1111 static const struct bpf_func_proto bpf_get_attach_cookie_proto_pe = { 1112 .func = bpf_get_attach_cookie_pe, 1113 .gpl_only = false, 1114 .ret_type = RET_INTEGER, 1115 .arg1_type = ARG_PTR_TO_CTX, 1116 }; 1117 1118 BPF_CALL_1(bpf_get_attach_cookie_tracing, void *, ctx) 1119 { 1120 struct bpf_trace_run_ctx *run_ctx; 1121 1122 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); 1123 return run_ctx->bpf_cookie; 1124 } 1125 1126 static const struct bpf_func_proto bpf_get_attach_cookie_proto_tracing = { 1127 .func = bpf_get_attach_cookie_tracing, 1128 .gpl_only = false, 1129 .ret_type = RET_INTEGER, 1130 .arg1_type = ARG_PTR_TO_CTX, 1131 }; 1132 1133 BPF_CALL_3(bpf_get_branch_snapshot, void *, buf, u32, size, u64, flags) 1134 { 1135 #ifndef CONFIG_X86 1136 return -ENOENT; 1137 #else 1138 static const u32 br_entry_size = sizeof(struct perf_branch_entry); 1139 u32 entry_cnt = size / br_entry_size; 1140 1141 entry_cnt = static_call(perf_snapshot_branch_stack)(buf, entry_cnt); 1142 1143 if (unlikely(flags)) 1144 return -EINVAL; 1145 1146 if (!entry_cnt) 1147 return -ENOENT; 1148 1149 return entry_cnt * br_entry_size; 1150 #endif 1151 } 1152 1153 static const struct bpf_func_proto bpf_get_branch_snapshot_proto = { 1154 .func = bpf_get_branch_snapshot, 1155 .gpl_only = true, 1156 .ret_type = RET_INTEGER, 1157 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 1158 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 1159 }; 1160 1161 BPF_CALL_3(get_func_arg, void *, ctx, u32, n, u64 *, value) 1162 { 1163 /* This helper call is inlined by verifier. */ 1164 u64 nr_args = ((u64 *)ctx)[-1]; 1165 1166 if ((u64) n >= nr_args) 1167 return -EINVAL; 1168 *value = ((u64 *)ctx)[n]; 1169 return 0; 1170 } 1171 1172 static const struct bpf_func_proto bpf_get_func_arg_proto = { 1173 .func = get_func_arg, 1174 .ret_type = RET_INTEGER, 1175 .arg1_type = ARG_PTR_TO_CTX, 1176 .arg2_type = ARG_ANYTHING, 1177 .arg3_type = ARG_PTR_TO_LONG, 1178 }; 1179 1180 BPF_CALL_2(get_func_ret, void *, ctx, u64 *, value) 1181 { 1182 /* This helper call is inlined by verifier. */ 1183 u64 nr_args = ((u64 *)ctx)[-1]; 1184 1185 *value = ((u64 *)ctx)[nr_args]; 1186 return 0; 1187 } 1188 1189 static const struct bpf_func_proto bpf_get_func_ret_proto = { 1190 .func = get_func_ret, 1191 .ret_type = RET_INTEGER, 1192 .arg1_type = ARG_PTR_TO_CTX, 1193 .arg2_type = ARG_PTR_TO_LONG, 1194 }; 1195 1196 BPF_CALL_1(get_func_arg_cnt, void *, ctx) 1197 { 1198 /* This helper call is inlined by verifier. */ 1199 return ((u64 *)ctx)[-1]; 1200 } 1201 1202 static const struct bpf_func_proto bpf_get_func_arg_cnt_proto = { 1203 .func = get_func_arg_cnt, 1204 .ret_type = RET_INTEGER, 1205 .arg1_type = ARG_PTR_TO_CTX, 1206 }; 1207 1208 #ifdef CONFIG_KEYS 1209 __diag_push(); 1210 __diag_ignore_all("-Wmissing-prototypes", 1211 "kfuncs which will be used in BPF programs"); 1212 1213 /** 1214 * bpf_lookup_user_key - lookup a key by its serial 1215 * @serial: key handle serial number 1216 * @flags: lookup-specific flags 1217 * 1218 * Search a key with a given *serial* and the provided *flags*. 1219 * If found, increment the reference count of the key by one, and 1220 * return it in the bpf_key structure. 1221 * 1222 * The bpf_key structure must be passed to bpf_key_put() when done 1223 * with it, so that the key reference count is decremented and the 1224 * bpf_key structure is freed. 1225 * 1226 * Permission checks are deferred to the time the key is used by 1227 * one of the available key-specific kfuncs. 1228 * 1229 * Set *flags* with KEY_LOOKUP_CREATE, to attempt creating a requested 1230 * special keyring (e.g. session keyring), if it doesn't yet exist. 1231 * Set *flags* with KEY_LOOKUP_PARTIAL, to lookup a key without waiting 1232 * for the key construction, and to retrieve uninstantiated keys (keys 1233 * without data attached to them). 1234 * 1235 * Return: a bpf_key pointer with a valid key pointer if the key is found, a 1236 * NULL pointer otherwise. 1237 */ 1238 __bpf_kfunc struct bpf_key *bpf_lookup_user_key(u32 serial, u64 flags) 1239 { 1240 key_ref_t key_ref; 1241 struct bpf_key *bkey; 1242 1243 if (flags & ~KEY_LOOKUP_ALL) 1244 return NULL; 1245 1246 /* 1247 * Permission check is deferred until the key is used, as the 1248 * intent of the caller is unknown here. 1249 */ 1250 key_ref = lookup_user_key(serial, flags, KEY_DEFER_PERM_CHECK); 1251 if (IS_ERR(key_ref)) 1252 return NULL; 1253 1254 bkey = kmalloc(sizeof(*bkey), GFP_KERNEL); 1255 if (!bkey) { 1256 key_put(key_ref_to_ptr(key_ref)); 1257 return NULL; 1258 } 1259 1260 bkey->key = key_ref_to_ptr(key_ref); 1261 bkey->has_ref = true; 1262 1263 return bkey; 1264 } 1265 1266 /** 1267 * bpf_lookup_system_key - lookup a key by a system-defined ID 1268 * @id: key ID 1269 * 1270 * Obtain a bpf_key structure with a key pointer set to the passed key ID. 1271 * The key pointer is marked as invalid, to prevent bpf_key_put() from 1272 * attempting to decrement the key reference count on that pointer. The key 1273 * pointer set in such way is currently understood only by 1274 * verify_pkcs7_signature(). 1275 * 1276 * Set *id* to one of the values defined in include/linux/verification.h: 1277 * 0 for the primary keyring (immutable keyring of system keys); 1278 * VERIFY_USE_SECONDARY_KEYRING for both the primary and secondary keyring 1279 * (where keys can be added only if they are vouched for by existing keys 1280 * in those keyrings); VERIFY_USE_PLATFORM_KEYRING for the platform 1281 * keyring (primarily used by the integrity subsystem to verify a kexec'ed 1282 * kerned image and, possibly, the initramfs signature). 1283 * 1284 * Return: a bpf_key pointer with an invalid key pointer set from the 1285 * pre-determined ID on success, a NULL pointer otherwise 1286 */ 1287 __bpf_kfunc struct bpf_key *bpf_lookup_system_key(u64 id) 1288 { 1289 struct bpf_key *bkey; 1290 1291 if (system_keyring_id_check(id) < 0) 1292 return NULL; 1293 1294 bkey = kmalloc(sizeof(*bkey), GFP_ATOMIC); 1295 if (!bkey) 1296 return NULL; 1297 1298 bkey->key = (struct key *)(unsigned long)id; 1299 bkey->has_ref = false; 1300 1301 return bkey; 1302 } 1303 1304 /** 1305 * bpf_key_put - decrement key reference count if key is valid and free bpf_key 1306 * @bkey: bpf_key structure 1307 * 1308 * Decrement the reference count of the key inside *bkey*, if the pointer 1309 * is valid, and free *bkey*. 1310 */ 1311 __bpf_kfunc void bpf_key_put(struct bpf_key *bkey) 1312 { 1313 if (bkey->has_ref) 1314 key_put(bkey->key); 1315 1316 kfree(bkey); 1317 } 1318 1319 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION 1320 /** 1321 * bpf_verify_pkcs7_signature - verify a PKCS#7 signature 1322 * @data_ptr: data to verify 1323 * @sig_ptr: signature of the data 1324 * @trusted_keyring: keyring with keys trusted for signature verification 1325 * 1326 * Verify the PKCS#7 signature *sig_ptr* against the supplied *data_ptr* 1327 * with keys in a keyring referenced by *trusted_keyring*. 1328 * 1329 * Return: 0 on success, a negative value on error. 1330 */ 1331 __bpf_kfunc int bpf_verify_pkcs7_signature(struct bpf_dynptr_kern *data_ptr, 1332 struct bpf_dynptr_kern *sig_ptr, 1333 struct bpf_key *trusted_keyring) 1334 { 1335 int ret; 1336 1337 if (trusted_keyring->has_ref) { 1338 /* 1339 * Do the permission check deferred in bpf_lookup_user_key(). 1340 * See bpf_lookup_user_key() for more details. 1341 * 1342 * A call to key_task_permission() here would be redundant, as 1343 * it is already done by keyring_search() called by 1344 * find_asymmetric_key(). 1345 */ 1346 ret = key_validate(trusted_keyring->key); 1347 if (ret < 0) 1348 return ret; 1349 } 1350 1351 return verify_pkcs7_signature(data_ptr->data, 1352 bpf_dynptr_get_size(data_ptr), 1353 sig_ptr->data, 1354 bpf_dynptr_get_size(sig_ptr), 1355 trusted_keyring->key, 1356 VERIFYING_UNSPECIFIED_SIGNATURE, NULL, 1357 NULL); 1358 } 1359 #endif /* CONFIG_SYSTEM_DATA_VERIFICATION */ 1360 1361 __diag_pop(); 1362 1363 BTF_SET8_START(key_sig_kfunc_set) 1364 BTF_ID_FLAGS(func, bpf_lookup_user_key, KF_ACQUIRE | KF_RET_NULL | KF_SLEEPABLE) 1365 BTF_ID_FLAGS(func, bpf_lookup_system_key, KF_ACQUIRE | KF_RET_NULL) 1366 BTF_ID_FLAGS(func, bpf_key_put, KF_RELEASE) 1367 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION 1368 BTF_ID_FLAGS(func, bpf_verify_pkcs7_signature, KF_SLEEPABLE) 1369 #endif 1370 BTF_SET8_END(key_sig_kfunc_set) 1371 1372 static const struct btf_kfunc_id_set bpf_key_sig_kfunc_set = { 1373 .owner = THIS_MODULE, 1374 .set = &key_sig_kfunc_set, 1375 }; 1376 1377 static int __init bpf_key_sig_kfuncs_init(void) 1378 { 1379 return register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, 1380 &bpf_key_sig_kfunc_set); 1381 } 1382 1383 late_initcall(bpf_key_sig_kfuncs_init); 1384 #endif /* CONFIG_KEYS */ 1385 1386 static const struct bpf_func_proto * 1387 bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1388 { 1389 switch (func_id) { 1390 case BPF_FUNC_map_lookup_elem: 1391 return &bpf_map_lookup_elem_proto; 1392 case BPF_FUNC_map_update_elem: 1393 return &bpf_map_update_elem_proto; 1394 case BPF_FUNC_map_delete_elem: 1395 return &bpf_map_delete_elem_proto; 1396 case BPF_FUNC_map_push_elem: 1397 return &bpf_map_push_elem_proto; 1398 case BPF_FUNC_map_pop_elem: 1399 return &bpf_map_pop_elem_proto; 1400 case BPF_FUNC_map_peek_elem: 1401 return &bpf_map_peek_elem_proto; 1402 case BPF_FUNC_map_lookup_percpu_elem: 1403 return &bpf_map_lookup_percpu_elem_proto; 1404 case BPF_FUNC_ktime_get_ns: 1405 return &bpf_ktime_get_ns_proto; 1406 case BPF_FUNC_ktime_get_boot_ns: 1407 return &bpf_ktime_get_boot_ns_proto; 1408 case BPF_FUNC_tail_call: 1409 return &bpf_tail_call_proto; 1410 case BPF_FUNC_get_current_pid_tgid: 1411 return &bpf_get_current_pid_tgid_proto; 1412 case BPF_FUNC_get_current_task: 1413 return &bpf_get_current_task_proto; 1414 case BPF_FUNC_get_current_task_btf: 1415 return &bpf_get_current_task_btf_proto; 1416 case BPF_FUNC_task_pt_regs: 1417 return &bpf_task_pt_regs_proto; 1418 case BPF_FUNC_get_current_uid_gid: 1419 return &bpf_get_current_uid_gid_proto; 1420 case BPF_FUNC_get_current_comm: 1421 return &bpf_get_current_comm_proto; 1422 case BPF_FUNC_trace_printk: 1423 return bpf_get_trace_printk_proto(); 1424 case BPF_FUNC_get_smp_processor_id: 1425 return &bpf_get_smp_processor_id_proto; 1426 case BPF_FUNC_get_numa_node_id: 1427 return &bpf_get_numa_node_id_proto; 1428 case BPF_FUNC_perf_event_read: 1429 return &bpf_perf_event_read_proto; 1430 case BPF_FUNC_current_task_under_cgroup: 1431 return &bpf_current_task_under_cgroup_proto; 1432 case BPF_FUNC_get_prandom_u32: 1433 return &bpf_get_prandom_u32_proto; 1434 case BPF_FUNC_probe_write_user: 1435 return security_locked_down(LOCKDOWN_BPF_WRITE_USER) < 0 ? 1436 NULL : bpf_get_probe_write_proto(); 1437 case BPF_FUNC_probe_read_user: 1438 return &bpf_probe_read_user_proto; 1439 case BPF_FUNC_probe_read_kernel: 1440 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1441 NULL : &bpf_probe_read_kernel_proto; 1442 case BPF_FUNC_probe_read_user_str: 1443 return &bpf_probe_read_user_str_proto; 1444 case BPF_FUNC_probe_read_kernel_str: 1445 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1446 NULL : &bpf_probe_read_kernel_str_proto; 1447 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 1448 case BPF_FUNC_probe_read: 1449 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1450 NULL : &bpf_probe_read_compat_proto; 1451 case BPF_FUNC_probe_read_str: 1452 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1453 NULL : &bpf_probe_read_compat_str_proto; 1454 #endif 1455 #ifdef CONFIG_CGROUPS 1456 case BPF_FUNC_cgrp_storage_get: 1457 return &bpf_cgrp_storage_get_proto; 1458 case BPF_FUNC_cgrp_storage_delete: 1459 return &bpf_cgrp_storage_delete_proto; 1460 #endif 1461 case BPF_FUNC_send_signal: 1462 return &bpf_send_signal_proto; 1463 case BPF_FUNC_send_signal_thread: 1464 return &bpf_send_signal_thread_proto; 1465 case BPF_FUNC_perf_event_read_value: 1466 return &bpf_perf_event_read_value_proto; 1467 case BPF_FUNC_get_ns_current_pid_tgid: 1468 return &bpf_get_ns_current_pid_tgid_proto; 1469 case BPF_FUNC_ringbuf_output: 1470 return &bpf_ringbuf_output_proto; 1471 case BPF_FUNC_ringbuf_reserve: 1472 return &bpf_ringbuf_reserve_proto; 1473 case BPF_FUNC_ringbuf_submit: 1474 return &bpf_ringbuf_submit_proto; 1475 case BPF_FUNC_ringbuf_discard: 1476 return &bpf_ringbuf_discard_proto; 1477 case BPF_FUNC_ringbuf_query: 1478 return &bpf_ringbuf_query_proto; 1479 case BPF_FUNC_jiffies64: 1480 return &bpf_jiffies64_proto; 1481 case BPF_FUNC_get_task_stack: 1482 return &bpf_get_task_stack_proto; 1483 case BPF_FUNC_copy_from_user: 1484 return &bpf_copy_from_user_proto; 1485 case BPF_FUNC_copy_from_user_task: 1486 return &bpf_copy_from_user_task_proto; 1487 case BPF_FUNC_snprintf_btf: 1488 return &bpf_snprintf_btf_proto; 1489 case BPF_FUNC_per_cpu_ptr: 1490 return &bpf_per_cpu_ptr_proto; 1491 case BPF_FUNC_this_cpu_ptr: 1492 return &bpf_this_cpu_ptr_proto; 1493 case BPF_FUNC_task_storage_get: 1494 if (bpf_prog_check_recur(prog)) 1495 return &bpf_task_storage_get_recur_proto; 1496 return &bpf_task_storage_get_proto; 1497 case BPF_FUNC_task_storage_delete: 1498 if (bpf_prog_check_recur(prog)) 1499 return &bpf_task_storage_delete_recur_proto; 1500 return &bpf_task_storage_delete_proto; 1501 case BPF_FUNC_for_each_map_elem: 1502 return &bpf_for_each_map_elem_proto; 1503 case BPF_FUNC_snprintf: 1504 return &bpf_snprintf_proto; 1505 case BPF_FUNC_get_func_ip: 1506 return &bpf_get_func_ip_proto_tracing; 1507 case BPF_FUNC_get_branch_snapshot: 1508 return &bpf_get_branch_snapshot_proto; 1509 case BPF_FUNC_find_vma: 1510 return &bpf_find_vma_proto; 1511 case BPF_FUNC_trace_vprintk: 1512 return bpf_get_trace_vprintk_proto(); 1513 default: 1514 return bpf_base_func_proto(func_id); 1515 } 1516 } 1517 1518 static const struct bpf_func_proto * 1519 kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1520 { 1521 switch (func_id) { 1522 case BPF_FUNC_perf_event_output: 1523 return &bpf_perf_event_output_proto; 1524 case BPF_FUNC_get_stackid: 1525 return &bpf_get_stackid_proto; 1526 case BPF_FUNC_get_stack: 1527 return &bpf_get_stack_proto; 1528 #ifdef CONFIG_BPF_KPROBE_OVERRIDE 1529 case BPF_FUNC_override_return: 1530 return &bpf_override_return_proto; 1531 #endif 1532 case BPF_FUNC_get_func_ip: 1533 return prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI ? 1534 &bpf_get_func_ip_proto_kprobe_multi : 1535 &bpf_get_func_ip_proto_kprobe; 1536 case BPF_FUNC_get_attach_cookie: 1537 return prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI ? 1538 &bpf_get_attach_cookie_proto_kmulti : 1539 &bpf_get_attach_cookie_proto_trace; 1540 default: 1541 return bpf_tracing_func_proto(func_id, prog); 1542 } 1543 } 1544 1545 /* bpf+kprobe programs can access fields of 'struct pt_regs' */ 1546 static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type, 1547 const struct bpf_prog *prog, 1548 struct bpf_insn_access_aux *info) 1549 { 1550 if (off < 0 || off >= sizeof(struct pt_regs)) 1551 return false; 1552 if (type != BPF_READ) 1553 return false; 1554 if (off % size != 0) 1555 return false; 1556 /* 1557 * Assertion for 32 bit to make sure last 8 byte access 1558 * (BPF_DW) to the last 4 byte member is disallowed. 1559 */ 1560 if (off + size > sizeof(struct pt_regs)) 1561 return false; 1562 1563 return true; 1564 } 1565 1566 const struct bpf_verifier_ops kprobe_verifier_ops = { 1567 .get_func_proto = kprobe_prog_func_proto, 1568 .is_valid_access = kprobe_prog_is_valid_access, 1569 }; 1570 1571 const struct bpf_prog_ops kprobe_prog_ops = { 1572 }; 1573 1574 BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map, 1575 u64, flags, void *, data, u64, size) 1576 { 1577 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1578 1579 /* 1580 * r1 points to perf tracepoint buffer where first 8 bytes are hidden 1581 * from bpf program and contain a pointer to 'struct pt_regs'. Fetch it 1582 * from there and call the same bpf_perf_event_output() helper inline. 1583 */ 1584 return ____bpf_perf_event_output(regs, map, flags, data, size); 1585 } 1586 1587 static const struct bpf_func_proto bpf_perf_event_output_proto_tp = { 1588 .func = bpf_perf_event_output_tp, 1589 .gpl_only = true, 1590 .ret_type = RET_INTEGER, 1591 .arg1_type = ARG_PTR_TO_CTX, 1592 .arg2_type = ARG_CONST_MAP_PTR, 1593 .arg3_type = ARG_ANYTHING, 1594 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1595 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 1596 }; 1597 1598 BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map, 1599 u64, flags) 1600 { 1601 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1602 1603 /* 1604 * Same comment as in bpf_perf_event_output_tp(), only that this time 1605 * the other helper's function body cannot be inlined due to being 1606 * external, thus we need to call raw helper function. 1607 */ 1608 return bpf_get_stackid((unsigned long) regs, (unsigned long) map, 1609 flags, 0, 0); 1610 } 1611 1612 static const struct bpf_func_proto bpf_get_stackid_proto_tp = { 1613 .func = bpf_get_stackid_tp, 1614 .gpl_only = true, 1615 .ret_type = RET_INTEGER, 1616 .arg1_type = ARG_PTR_TO_CTX, 1617 .arg2_type = ARG_CONST_MAP_PTR, 1618 .arg3_type = ARG_ANYTHING, 1619 }; 1620 1621 BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size, 1622 u64, flags) 1623 { 1624 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1625 1626 return bpf_get_stack((unsigned long) regs, (unsigned long) buf, 1627 (unsigned long) size, flags, 0); 1628 } 1629 1630 static const struct bpf_func_proto bpf_get_stack_proto_tp = { 1631 .func = bpf_get_stack_tp, 1632 .gpl_only = true, 1633 .ret_type = RET_INTEGER, 1634 .arg1_type = ARG_PTR_TO_CTX, 1635 .arg2_type = ARG_PTR_TO_UNINIT_MEM, 1636 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1637 .arg4_type = ARG_ANYTHING, 1638 }; 1639 1640 static const struct bpf_func_proto * 1641 tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1642 { 1643 switch (func_id) { 1644 case BPF_FUNC_perf_event_output: 1645 return &bpf_perf_event_output_proto_tp; 1646 case BPF_FUNC_get_stackid: 1647 return &bpf_get_stackid_proto_tp; 1648 case BPF_FUNC_get_stack: 1649 return &bpf_get_stack_proto_tp; 1650 case BPF_FUNC_get_attach_cookie: 1651 return &bpf_get_attach_cookie_proto_trace; 1652 default: 1653 return bpf_tracing_func_proto(func_id, prog); 1654 } 1655 } 1656 1657 static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type, 1658 const struct bpf_prog *prog, 1659 struct bpf_insn_access_aux *info) 1660 { 1661 if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE) 1662 return false; 1663 if (type != BPF_READ) 1664 return false; 1665 if (off % size != 0) 1666 return false; 1667 1668 BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(__u64)); 1669 return true; 1670 } 1671 1672 const struct bpf_verifier_ops tracepoint_verifier_ops = { 1673 .get_func_proto = tp_prog_func_proto, 1674 .is_valid_access = tp_prog_is_valid_access, 1675 }; 1676 1677 const struct bpf_prog_ops tracepoint_prog_ops = { 1678 }; 1679 1680 BPF_CALL_3(bpf_perf_prog_read_value, struct bpf_perf_event_data_kern *, ctx, 1681 struct bpf_perf_event_value *, buf, u32, size) 1682 { 1683 int err = -EINVAL; 1684 1685 if (unlikely(size != sizeof(struct bpf_perf_event_value))) 1686 goto clear; 1687 err = perf_event_read_local(ctx->event, &buf->counter, &buf->enabled, 1688 &buf->running); 1689 if (unlikely(err)) 1690 goto clear; 1691 return 0; 1692 clear: 1693 memset(buf, 0, size); 1694 return err; 1695 } 1696 1697 static const struct bpf_func_proto bpf_perf_prog_read_value_proto = { 1698 .func = bpf_perf_prog_read_value, 1699 .gpl_only = true, 1700 .ret_type = RET_INTEGER, 1701 .arg1_type = ARG_PTR_TO_CTX, 1702 .arg2_type = ARG_PTR_TO_UNINIT_MEM, 1703 .arg3_type = ARG_CONST_SIZE, 1704 }; 1705 1706 BPF_CALL_4(bpf_read_branch_records, struct bpf_perf_event_data_kern *, ctx, 1707 void *, buf, u32, size, u64, flags) 1708 { 1709 static const u32 br_entry_size = sizeof(struct perf_branch_entry); 1710 struct perf_branch_stack *br_stack = ctx->data->br_stack; 1711 u32 to_copy; 1712 1713 if (unlikely(flags & ~BPF_F_GET_BRANCH_RECORDS_SIZE)) 1714 return -EINVAL; 1715 1716 if (unlikely(!(ctx->data->sample_flags & PERF_SAMPLE_BRANCH_STACK))) 1717 return -ENOENT; 1718 1719 if (unlikely(!br_stack)) 1720 return -ENOENT; 1721 1722 if (flags & BPF_F_GET_BRANCH_RECORDS_SIZE) 1723 return br_stack->nr * br_entry_size; 1724 1725 if (!buf || (size % br_entry_size != 0)) 1726 return -EINVAL; 1727 1728 to_copy = min_t(u32, br_stack->nr * br_entry_size, size); 1729 memcpy(buf, br_stack->entries, to_copy); 1730 1731 return to_copy; 1732 } 1733 1734 static const struct bpf_func_proto bpf_read_branch_records_proto = { 1735 .func = bpf_read_branch_records, 1736 .gpl_only = true, 1737 .ret_type = RET_INTEGER, 1738 .arg1_type = ARG_PTR_TO_CTX, 1739 .arg2_type = ARG_PTR_TO_MEM_OR_NULL, 1740 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1741 .arg4_type = ARG_ANYTHING, 1742 }; 1743 1744 static const struct bpf_func_proto * 1745 pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1746 { 1747 switch (func_id) { 1748 case BPF_FUNC_perf_event_output: 1749 return &bpf_perf_event_output_proto_tp; 1750 case BPF_FUNC_get_stackid: 1751 return &bpf_get_stackid_proto_pe; 1752 case BPF_FUNC_get_stack: 1753 return &bpf_get_stack_proto_pe; 1754 case BPF_FUNC_perf_prog_read_value: 1755 return &bpf_perf_prog_read_value_proto; 1756 case BPF_FUNC_read_branch_records: 1757 return &bpf_read_branch_records_proto; 1758 case BPF_FUNC_get_attach_cookie: 1759 return &bpf_get_attach_cookie_proto_pe; 1760 default: 1761 return bpf_tracing_func_proto(func_id, prog); 1762 } 1763 } 1764 1765 /* 1766 * bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp 1767 * to avoid potential recursive reuse issue when/if tracepoints are added 1768 * inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack. 1769 * 1770 * Since raw tracepoints run despite bpf_prog_active, support concurrent usage 1771 * in normal, irq, and nmi context. 1772 */ 1773 struct bpf_raw_tp_regs { 1774 struct pt_regs regs[3]; 1775 }; 1776 static DEFINE_PER_CPU(struct bpf_raw_tp_regs, bpf_raw_tp_regs); 1777 static DEFINE_PER_CPU(int, bpf_raw_tp_nest_level); 1778 static struct pt_regs *get_bpf_raw_tp_regs(void) 1779 { 1780 struct bpf_raw_tp_regs *tp_regs = this_cpu_ptr(&bpf_raw_tp_regs); 1781 int nest_level = this_cpu_inc_return(bpf_raw_tp_nest_level); 1782 1783 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(tp_regs->regs))) { 1784 this_cpu_dec(bpf_raw_tp_nest_level); 1785 return ERR_PTR(-EBUSY); 1786 } 1787 1788 return &tp_regs->regs[nest_level - 1]; 1789 } 1790 1791 static void put_bpf_raw_tp_regs(void) 1792 { 1793 this_cpu_dec(bpf_raw_tp_nest_level); 1794 } 1795 1796 BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args, 1797 struct bpf_map *, map, u64, flags, void *, data, u64, size) 1798 { 1799 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1800 int ret; 1801 1802 if (IS_ERR(regs)) 1803 return PTR_ERR(regs); 1804 1805 perf_fetch_caller_regs(regs); 1806 ret = ____bpf_perf_event_output(regs, map, flags, data, size); 1807 1808 put_bpf_raw_tp_regs(); 1809 return ret; 1810 } 1811 1812 static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = { 1813 .func = bpf_perf_event_output_raw_tp, 1814 .gpl_only = true, 1815 .ret_type = RET_INTEGER, 1816 .arg1_type = ARG_PTR_TO_CTX, 1817 .arg2_type = ARG_CONST_MAP_PTR, 1818 .arg3_type = ARG_ANYTHING, 1819 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1820 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 1821 }; 1822 1823 extern const struct bpf_func_proto bpf_skb_output_proto; 1824 extern const struct bpf_func_proto bpf_xdp_output_proto; 1825 extern const struct bpf_func_proto bpf_xdp_get_buff_len_trace_proto; 1826 1827 BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args, 1828 struct bpf_map *, map, u64, flags) 1829 { 1830 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1831 int ret; 1832 1833 if (IS_ERR(regs)) 1834 return PTR_ERR(regs); 1835 1836 perf_fetch_caller_regs(regs); 1837 /* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */ 1838 ret = bpf_get_stackid((unsigned long) regs, (unsigned long) map, 1839 flags, 0, 0); 1840 put_bpf_raw_tp_regs(); 1841 return ret; 1842 } 1843 1844 static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = { 1845 .func = bpf_get_stackid_raw_tp, 1846 .gpl_only = true, 1847 .ret_type = RET_INTEGER, 1848 .arg1_type = ARG_PTR_TO_CTX, 1849 .arg2_type = ARG_CONST_MAP_PTR, 1850 .arg3_type = ARG_ANYTHING, 1851 }; 1852 1853 BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args, 1854 void *, buf, u32, size, u64, flags) 1855 { 1856 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1857 int ret; 1858 1859 if (IS_ERR(regs)) 1860 return PTR_ERR(regs); 1861 1862 perf_fetch_caller_regs(regs); 1863 ret = bpf_get_stack((unsigned long) regs, (unsigned long) buf, 1864 (unsigned long) size, flags, 0); 1865 put_bpf_raw_tp_regs(); 1866 return ret; 1867 } 1868 1869 static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = { 1870 .func = bpf_get_stack_raw_tp, 1871 .gpl_only = true, 1872 .ret_type = RET_INTEGER, 1873 .arg1_type = ARG_PTR_TO_CTX, 1874 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1875 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1876 .arg4_type = ARG_ANYTHING, 1877 }; 1878 1879 static const struct bpf_func_proto * 1880 raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1881 { 1882 switch (func_id) { 1883 case BPF_FUNC_perf_event_output: 1884 return &bpf_perf_event_output_proto_raw_tp; 1885 case BPF_FUNC_get_stackid: 1886 return &bpf_get_stackid_proto_raw_tp; 1887 case BPF_FUNC_get_stack: 1888 return &bpf_get_stack_proto_raw_tp; 1889 default: 1890 return bpf_tracing_func_proto(func_id, prog); 1891 } 1892 } 1893 1894 const struct bpf_func_proto * 1895 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1896 { 1897 const struct bpf_func_proto *fn; 1898 1899 switch (func_id) { 1900 #ifdef CONFIG_NET 1901 case BPF_FUNC_skb_output: 1902 return &bpf_skb_output_proto; 1903 case BPF_FUNC_xdp_output: 1904 return &bpf_xdp_output_proto; 1905 case BPF_FUNC_skc_to_tcp6_sock: 1906 return &bpf_skc_to_tcp6_sock_proto; 1907 case BPF_FUNC_skc_to_tcp_sock: 1908 return &bpf_skc_to_tcp_sock_proto; 1909 case BPF_FUNC_skc_to_tcp_timewait_sock: 1910 return &bpf_skc_to_tcp_timewait_sock_proto; 1911 case BPF_FUNC_skc_to_tcp_request_sock: 1912 return &bpf_skc_to_tcp_request_sock_proto; 1913 case BPF_FUNC_skc_to_udp6_sock: 1914 return &bpf_skc_to_udp6_sock_proto; 1915 case BPF_FUNC_skc_to_unix_sock: 1916 return &bpf_skc_to_unix_sock_proto; 1917 case BPF_FUNC_skc_to_mptcp_sock: 1918 return &bpf_skc_to_mptcp_sock_proto; 1919 case BPF_FUNC_sk_storage_get: 1920 return &bpf_sk_storage_get_tracing_proto; 1921 case BPF_FUNC_sk_storage_delete: 1922 return &bpf_sk_storage_delete_tracing_proto; 1923 case BPF_FUNC_sock_from_file: 1924 return &bpf_sock_from_file_proto; 1925 case BPF_FUNC_get_socket_cookie: 1926 return &bpf_get_socket_ptr_cookie_proto; 1927 case BPF_FUNC_xdp_get_buff_len: 1928 return &bpf_xdp_get_buff_len_trace_proto; 1929 #endif 1930 case BPF_FUNC_seq_printf: 1931 return prog->expected_attach_type == BPF_TRACE_ITER ? 1932 &bpf_seq_printf_proto : 1933 NULL; 1934 case BPF_FUNC_seq_write: 1935 return prog->expected_attach_type == BPF_TRACE_ITER ? 1936 &bpf_seq_write_proto : 1937 NULL; 1938 case BPF_FUNC_seq_printf_btf: 1939 return prog->expected_attach_type == BPF_TRACE_ITER ? 1940 &bpf_seq_printf_btf_proto : 1941 NULL; 1942 case BPF_FUNC_d_path: 1943 return &bpf_d_path_proto; 1944 case BPF_FUNC_get_func_arg: 1945 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_proto : NULL; 1946 case BPF_FUNC_get_func_ret: 1947 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_ret_proto : NULL; 1948 case BPF_FUNC_get_func_arg_cnt: 1949 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_cnt_proto : NULL; 1950 case BPF_FUNC_get_attach_cookie: 1951 return bpf_prog_has_trampoline(prog) ? &bpf_get_attach_cookie_proto_tracing : NULL; 1952 default: 1953 fn = raw_tp_prog_func_proto(func_id, prog); 1954 if (!fn && prog->expected_attach_type == BPF_TRACE_ITER) 1955 fn = bpf_iter_get_func_proto(func_id, prog); 1956 return fn; 1957 } 1958 } 1959 1960 static bool raw_tp_prog_is_valid_access(int off, int size, 1961 enum bpf_access_type type, 1962 const struct bpf_prog *prog, 1963 struct bpf_insn_access_aux *info) 1964 { 1965 return bpf_tracing_ctx_access(off, size, type); 1966 } 1967 1968 static bool tracing_prog_is_valid_access(int off, int size, 1969 enum bpf_access_type type, 1970 const struct bpf_prog *prog, 1971 struct bpf_insn_access_aux *info) 1972 { 1973 return bpf_tracing_btf_ctx_access(off, size, type, prog, info); 1974 } 1975 1976 int __weak bpf_prog_test_run_tracing(struct bpf_prog *prog, 1977 const union bpf_attr *kattr, 1978 union bpf_attr __user *uattr) 1979 { 1980 return -ENOTSUPP; 1981 } 1982 1983 const struct bpf_verifier_ops raw_tracepoint_verifier_ops = { 1984 .get_func_proto = raw_tp_prog_func_proto, 1985 .is_valid_access = raw_tp_prog_is_valid_access, 1986 }; 1987 1988 const struct bpf_prog_ops raw_tracepoint_prog_ops = { 1989 #ifdef CONFIG_NET 1990 .test_run = bpf_prog_test_run_raw_tp, 1991 #endif 1992 }; 1993 1994 const struct bpf_verifier_ops tracing_verifier_ops = { 1995 .get_func_proto = tracing_prog_func_proto, 1996 .is_valid_access = tracing_prog_is_valid_access, 1997 }; 1998 1999 const struct bpf_prog_ops tracing_prog_ops = { 2000 .test_run = bpf_prog_test_run_tracing, 2001 }; 2002 2003 static bool raw_tp_writable_prog_is_valid_access(int off, int size, 2004 enum bpf_access_type type, 2005 const struct bpf_prog *prog, 2006 struct bpf_insn_access_aux *info) 2007 { 2008 if (off == 0) { 2009 if (size != sizeof(u64) || type != BPF_READ) 2010 return false; 2011 info->reg_type = PTR_TO_TP_BUFFER; 2012 } 2013 return raw_tp_prog_is_valid_access(off, size, type, prog, info); 2014 } 2015 2016 const struct bpf_verifier_ops raw_tracepoint_writable_verifier_ops = { 2017 .get_func_proto = raw_tp_prog_func_proto, 2018 .is_valid_access = raw_tp_writable_prog_is_valid_access, 2019 }; 2020 2021 const struct bpf_prog_ops raw_tracepoint_writable_prog_ops = { 2022 }; 2023 2024 static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type, 2025 const struct bpf_prog *prog, 2026 struct bpf_insn_access_aux *info) 2027 { 2028 const int size_u64 = sizeof(u64); 2029 2030 if (off < 0 || off >= sizeof(struct bpf_perf_event_data)) 2031 return false; 2032 if (type != BPF_READ) 2033 return false; 2034 if (off % size != 0) { 2035 if (sizeof(unsigned long) != 4) 2036 return false; 2037 if (size != 8) 2038 return false; 2039 if (off % size != 4) 2040 return false; 2041 } 2042 2043 switch (off) { 2044 case bpf_ctx_range(struct bpf_perf_event_data, sample_period): 2045 bpf_ctx_record_field_size(info, size_u64); 2046 if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) 2047 return false; 2048 break; 2049 case bpf_ctx_range(struct bpf_perf_event_data, addr): 2050 bpf_ctx_record_field_size(info, size_u64); 2051 if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) 2052 return false; 2053 break; 2054 default: 2055 if (size != sizeof(long)) 2056 return false; 2057 } 2058 2059 return true; 2060 } 2061 2062 static u32 pe_prog_convert_ctx_access(enum bpf_access_type type, 2063 const struct bpf_insn *si, 2064 struct bpf_insn *insn_buf, 2065 struct bpf_prog *prog, u32 *target_size) 2066 { 2067 struct bpf_insn *insn = insn_buf; 2068 2069 switch (si->off) { 2070 case offsetof(struct bpf_perf_event_data, sample_period): 2071 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 2072 data), si->dst_reg, si->src_reg, 2073 offsetof(struct bpf_perf_event_data_kern, data)); 2074 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, 2075 bpf_target_off(struct perf_sample_data, period, 8, 2076 target_size)); 2077 break; 2078 case offsetof(struct bpf_perf_event_data, addr): 2079 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 2080 data), si->dst_reg, si->src_reg, 2081 offsetof(struct bpf_perf_event_data_kern, data)); 2082 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, 2083 bpf_target_off(struct perf_sample_data, addr, 8, 2084 target_size)); 2085 break; 2086 default: 2087 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 2088 regs), si->dst_reg, si->src_reg, 2089 offsetof(struct bpf_perf_event_data_kern, regs)); 2090 *insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg, 2091 si->off); 2092 break; 2093 } 2094 2095 return insn - insn_buf; 2096 } 2097 2098 const struct bpf_verifier_ops perf_event_verifier_ops = { 2099 .get_func_proto = pe_prog_func_proto, 2100 .is_valid_access = pe_prog_is_valid_access, 2101 .convert_ctx_access = pe_prog_convert_ctx_access, 2102 }; 2103 2104 const struct bpf_prog_ops perf_event_prog_ops = { 2105 }; 2106 2107 static DEFINE_MUTEX(bpf_event_mutex); 2108 2109 #define BPF_TRACE_MAX_PROGS 64 2110 2111 int perf_event_attach_bpf_prog(struct perf_event *event, 2112 struct bpf_prog *prog, 2113 u64 bpf_cookie) 2114 { 2115 struct bpf_prog_array *old_array; 2116 struct bpf_prog_array *new_array; 2117 int ret = -EEXIST; 2118 2119 /* 2120 * Kprobe override only works if they are on the function entry, 2121 * and only if they are on the opt-in list. 2122 */ 2123 if (prog->kprobe_override && 2124 (!trace_kprobe_on_func_entry(event->tp_event) || 2125 !trace_kprobe_error_injectable(event->tp_event))) 2126 return -EINVAL; 2127 2128 mutex_lock(&bpf_event_mutex); 2129 2130 if (event->prog) 2131 goto unlock; 2132 2133 old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); 2134 if (old_array && 2135 bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) { 2136 ret = -E2BIG; 2137 goto unlock; 2138 } 2139 2140 ret = bpf_prog_array_copy(old_array, NULL, prog, bpf_cookie, &new_array); 2141 if (ret < 0) 2142 goto unlock; 2143 2144 /* set the new array to event->tp_event and set event->prog */ 2145 event->prog = prog; 2146 event->bpf_cookie = bpf_cookie; 2147 rcu_assign_pointer(event->tp_event->prog_array, new_array); 2148 bpf_prog_array_free_sleepable(old_array); 2149 2150 unlock: 2151 mutex_unlock(&bpf_event_mutex); 2152 return ret; 2153 } 2154 2155 void perf_event_detach_bpf_prog(struct perf_event *event) 2156 { 2157 struct bpf_prog_array *old_array; 2158 struct bpf_prog_array *new_array; 2159 int ret; 2160 2161 mutex_lock(&bpf_event_mutex); 2162 2163 if (!event->prog) 2164 goto unlock; 2165 2166 old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); 2167 ret = bpf_prog_array_copy(old_array, event->prog, NULL, 0, &new_array); 2168 if (ret == -ENOENT) 2169 goto unlock; 2170 if (ret < 0) { 2171 bpf_prog_array_delete_safe(old_array, event->prog); 2172 } else { 2173 rcu_assign_pointer(event->tp_event->prog_array, new_array); 2174 bpf_prog_array_free_sleepable(old_array); 2175 } 2176 2177 bpf_prog_put(event->prog); 2178 event->prog = NULL; 2179 2180 unlock: 2181 mutex_unlock(&bpf_event_mutex); 2182 } 2183 2184 int perf_event_query_prog_array(struct perf_event *event, void __user *info) 2185 { 2186 struct perf_event_query_bpf __user *uquery = info; 2187 struct perf_event_query_bpf query = {}; 2188 struct bpf_prog_array *progs; 2189 u32 *ids, prog_cnt, ids_len; 2190 int ret; 2191 2192 if (!perfmon_capable()) 2193 return -EPERM; 2194 if (event->attr.type != PERF_TYPE_TRACEPOINT) 2195 return -EINVAL; 2196 if (copy_from_user(&query, uquery, sizeof(query))) 2197 return -EFAULT; 2198 2199 ids_len = query.ids_len; 2200 if (ids_len > BPF_TRACE_MAX_PROGS) 2201 return -E2BIG; 2202 ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN); 2203 if (!ids) 2204 return -ENOMEM; 2205 /* 2206 * The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which 2207 * is required when user only wants to check for uquery->prog_cnt. 2208 * There is no need to check for it since the case is handled 2209 * gracefully in bpf_prog_array_copy_info. 2210 */ 2211 2212 mutex_lock(&bpf_event_mutex); 2213 progs = bpf_event_rcu_dereference(event->tp_event->prog_array); 2214 ret = bpf_prog_array_copy_info(progs, ids, ids_len, &prog_cnt); 2215 mutex_unlock(&bpf_event_mutex); 2216 2217 if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) || 2218 copy_to_user(uquery->ids, ids, ids_len * sizeof(u32))) 2219 ret = -EFAULT; 2220 2221 kfree(ids); 2222 return ret; 2223 } 2224 2225 extern struct bpf_raw_event_map __start__bpf_raw_tp[]; 2226 extern struct bpf_raw_event_map __stop__bpf_raw_tp[]; 2227 2228 struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name) 2229 { 2230 struct bpf_raw_event_map *btp = __start__bpf_raw_tp; 2231 2232 for (; btp < __stop__bpf_raw_tp; btp++) { 2233 if (!strcmp(btp->tp->name, name)) 2234 return btp; 2235 } 2236 2237 return bpf_get_raw_tracepoint_module(name); 2238 } 2239 2240 void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp) 2241 { 2242 struct module *mod; 2243 2244 preempt_disable(); 2245 mod = __module_address((unsigned long)btp); 2246 module_put(mod); 2247 preempt_enable(); 2248 } 2249 2250 static __always_inline 2251 void __bpf_trace_run(struct bpf_prog *prog, u64 *args) 2252 { 2253 cant_sleep(); 2254 if (unlikely(this_cpu_inc_return(*(prog->active)) != 1)) { 2255 bpf_prog_inc_misses_counter(prog); 2256 goto out; 2257 } 2258 rcu_read_lock(); 2259 (void) bpf_prog_run(prog, args); 2260 rcu_read_unlock(); 2261 out: 2262 this_cpu_dec(*(prog->active)); 2263 } 2264 2265 #define UNPACK(...) __VA_ARGS__ 2266 #define REPEAT_1(FN, DL, X, ...) FN(X) 2267 #define REPEAT_2(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__) 2268 #define REPEAT_3(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_2(FN, DL, __VA_ARGS__) 2269 #define REPEAT_4(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_3(FN, DL, __VA_ARGS__) 2270 #define REPEAT_5(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_4(FN, DL, __VA_ARGS__) 2271 #define REPEAT_6(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_5(FN, DL, __VA_ARGS__) 2272 #define REPEAT_7(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_6(FN, DL, __VA_ARGS__) 2273 #define REPEAT_8(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_7(FN, DL, __VA_ARGS__) 2274 #define REPEAT_9(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_8(FN, DL, __VA_ARGS__) 2275 #define REPEAT_10(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_9(FN, DL, __VA_ARGS__) 2276 #define REPEAT_11(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_10(FN, DL, __VA_ARGS__) 2277 #define REPEAT_12(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_11(FN, DL, __VA_ARGS__) 2278 #define REPEAT(X, FN, DL, ...) REPEAT_##X(FN, DL, __VA_ARGS__) 2279 2280 #define SARG(X) u64 arg##X 2281 #define COPY(X) args[X] = arg##X 2282 2283 #define __DL_COM (,) 2284 #define __DL_SEM (;) 2285 2286 #define __SEQ_0_11 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 2287 2288 #define BPF_TRACE_DEFN_x(x) \ 2289 void bpf_trace_run##x(struct bpf_prog *prog, \ 2290 REPEAT(x, SARG, __DL_COM, __SEQ_0_11)) \ 2291 { \ 2292 u64 args[x]; \ 2293 REPEAT(x, COPY, __DL_SEM, __SEQ_0_11); \ 2294 __bpf_trace_run(prog, args); \ 2295 } \ 2296 EXPORT_SYMBOL_GPL(bpf_trace_run##x) 2297 BPF_TRACE_DEFN_x(1); 2298 BPF_TRACE_DEFN_x(2); 2299 BPF_TRACE_DEFN_x(3); 2300 BPF_TRACE_DEFN_x(4); 2301 BPF_TRACE_DEFN_x(5); 2302 BPF_TRACE_DEFN_x(6); 2303 BPF_TRACE_DEFN_x(7); 2304 BPF_TRACE_DEFN_x(8); 2305 BPF_TRACE_DEFN_x(9); 2306 BPF_TRACE_DEFN_x(10); 2307 BPF_TRACE_DEFN_x(11); 2308 BPF_TRACE_DEFN_x(12); 2309 2310 static int __bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog) 2311 { 2312 struct tracepoint *tp = btp->tp; 2313 2314 /* 2315 * check that program doesn't access arguments beyond what's 2316 * available in this tracepoint 2317 */ 2318 if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64)) 2319 return -EINVAL; 2320 2321 if (prog->aux->max_tp_access > btp->writable_size) 2322 return -EINVAL; 2323 2324 return tracepoint_probe_register_may_exist(tp, (void *)btp->bpf_func, 2325 prog); 2326 } 2327 2328 int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog) 2329 { 2330 return __bpf_probe_register(btp, prog); 2331 } 2332 2333 int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_prog *prog) 2334 { 2335 return tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, prog); 2336 } 2337 2338 int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id, 2339 u32 *fd_type, const char **buf, 2340 u64 *probe_offset, u64 *probe_addr) 2341 { 2342 bool is_tracepoint, is_syscall_tp; 2343 struct bpf_prog *prog; 2344 int flags, err = 0; 2345 2346 prog = event->prog; 2347 if (!prog) 2348 return -ENOENT; 2349 2350 /* not supporting BPF_PROG_TYPE_PERF_EVENT yet */ 2351 if (prog->type == BPF_PROG_TYPE_PERF_EVENT) 2352 return -EOPNOTSUPP; 2353 2354 *prog_id = prog->aux->id; 2355 flags = event->tp_event->flags; 2356 is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT; 2357 is_syscall_tp = is_syscall_trace_event(event->tp_event); 2358 2359 if (is_tracepoint || is_syscall_tp) { 2360 *buf = is_tracepoint ? event->tp_event->tp->name 2361 : event->tp_event->name; 2362 *fd_type = BPF_FD_TYPE_TRACEPOINT; 2363 *probe_offset = 0x0; 2364 *probe_addr = 0x0; 2365 } else { 2366 /* kprobe/uprobe */ 2367 err = -EOPNOTSUPP; 2368 #ifdef CONFIG_KPROBE_EVENTS 2369 if (flags & TRACE_EVENT_FL_KPROBE) 2370 err = bpf_get_kprobe_info(event, fd_type, buf, 2371 probe_offset, probe_addr, 2372 event->attr.type == PERF_TYPE_TRACEPOINT); 2373 #endif 2374 #ifdef CONFIG_UPROBE_EVENTS 2375 if (flags & TRACE_EVENT_FL_UPROBE) 2376 err = bpf_get_uprobe_info(event, fd_type, buf, 2377 probe_offset, 2378 event->attr.type == PERF_TYPE_TRACEPOINT); 2379 #endif 2380 } 2381 2382 return err; 2383 } 2384 2385 static int __init send_signal_irq_work_init(void) 2386 { 2387 int cpu; 2388 struct send_signal_irq_work *work; 2389 2390 for_each_possible_cpu(cpu) { 2391 work = per_cpu_ptr(&send_signal_work, cpu); 2392 init_irq_work(&work->irq_work, do_bpf_send_signal); 2393 } 2394 return 0; 2395 } 2396 2397 subsys_initcall(send_signal_irq_work_init); 2398 2399 #ifdef CONFIG_MODULES 2400 static int bpf_event_notify(struct notifier_block *nb, unsigned long op, 2401 void *module) 2402 { 2403 struct bpf_trace_module *btm, *tmp; 2404 struct module *mod = module; 2405 int ret = 0; 2406 2407 if (mod->num_bpf_raw_events == 0 || 2408 (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING)) 2409 goto out; 2410 2411 mutex_lock(&bpf_module_mutex); 2412 2413 switch (op) { 2414 case MODULE_STATE_COMING: 2415 btm = kzalloc(sizeof(*btm), GFP_KERNEL); 2416 if (btm) { 2417 btm->module = module; 2418 list_add(&btm->list, &bpf_trace_modules); 2419 } else { 2420 ret = -ENOMEM; 2421 } 2422 break; 2423 case MODULE_STATE_GOING: 2424 list_for_each_entry_safe(btm, tmp, &bpf_trace_modules, list) { 2425 if (btm->module == module) { 2426 list_del(&btm->list); 2427 kfree(btm); 2428 break; 2429 } 2430 } 2431 break; 2432 } 2433 2434 mutex_unlock(&bpf_module_mutex); 2435 2436 out: 2437 return notifier_from_errno(ret); 2438 } 2439 2440 static struct notifier_block bpf_module_nb = { 2441 .notifier_call = bpf_event_notify, 2442 }; 2443 2444 static int __init bpf_event_init(void) 2445 { 2446 register_module_notifier(&bpf_module_nb); 2447 return 0; 2448 } 2449 2450 fs_initcall(bpf_event_init); 2451 #endif /* CONFIG_MODULES */ 2452 2453 #ifdef CONFIG_FPROBE 2454 struct bpf_kprobe_multi_link { 2455 struct bpf_link link; 2456 struct fprobe fp; 2457 unsigned long *addrs; 2458 u64 *cookies; 2459 u32 cnt; 2460 u32 mods_cnt; 2461 struct module **mods; 2462 }; 2463 2464 struct bpf_kprobe_multi_run_ctx { 2465 struct bpf_run_ctx run_ctx; 2466 struct bpf_kprobe_multi_link *link; 2467 unsigned long entry_ip; 2468 }; 2469 2470 struct user_syms { 2471 const char **syms; 2472 char *buf; 2473 }; 2474 2475 static int copy_user_syms(struct user_syms *us, unsigned long __user *usyms, u32 cnt) 2476 { 2477 unsigned long __user usymbol; 2478 const char **syms = NULL; 2479 char *buf = NULL, *p; 2480 int err = -ENOMEM; 2481 unsigned int i; 2482 2483 syms = kvmalloc_array(cnt, sizeof(*syms), GFP_KERNEL); 2484 if (!syms) 2485 goto error; 2486 2487 buf = kvmalloc_array(cnt, KSYM_NAME_LEN, GFP_KERNEL); 2488 if (!buf) 2489 goto error; 2490 2491 for (p = buf, i = 0; i < cnt; i++) { 2492 if (__get_user(usymbol, usyms + i)) { 2493 err = -EFAULT; 2494 goto error; 2495 } 2496 err = strncpy_from_user(p, (const char __user *) usymbol, KSYM_NAME_LEN); 2497 if (err == KSYM_NAME_LEN) 2498 err = -E2BIG; 2499 if (err < 0) 2500 goto error; 2501 syms[i] = p; 2502 p += err + 1; 2503 } 2504 2505 us->syms = syms; 2506 us->buf = buf; 2507 return 0; 2508 2509 error: 2510 if (err) { 2511 kvfree(syms); 2512 kvfree(buf); 2513 } 2514 return err; 2515 } 2516 2517 static void kprobe_multi_put_modules(struct module **mods, u32 cnt) 2518 { 2519 u32 i; 2520 2521 for (i = 0; i < cnt; i++) 2522 module_put(mods[i]); 2523 } 2524 2525 static void free_user_syms(struct user_syms *us) 2526 { 2527 kvfree(us->syms); 2528 kvfree(us->buf); 2529 } 2530 2531 static void bpf_kprobe_multi_link_release(struct bpf_link *link) 2532 { 2533 struct bpf_kprobe_multi_link *kmulti_link; 2534 2535 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); 2536 unregister_fprobe(&kmulti_link->fp); 2537 kprobe_multi_put_modules(kmulti_link->mods, kmulti_link->mods_cnt); 2538 } 2539 2540 static void bpf_kprobe_multi_link_dealloc(struct bpf_link *link) 2541 { 2542 struct bpf_kprobe_multi_link *kmulti_link; 2543 2544 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); 2545 kvfree(kmulti_link->addrs); 2546 kvfree(kmulti_link->cookies); 2547 kfree(kmulti_link->mods); 2548 kfree(kmulti_link); 2549 } 2550 2551 static const struct bpf_link_ops bpf_kprobe_multi_link_lops = { 2552 .release = bpf_kprobe_multi_link_release, 2553 .dealloc = bpf_kprobe_multi_link_dealloc, 2554 }; 2555 2556 static void bpf_kprobe_multi_cookie_swap(void *a, void *b, int size, const void *priv) 2557 { 2558 const struct bpf_kprobe_multi_link *link = priv; 2559 unsigned long *addr_a = a, *addr_b = b; 2560 u64 *cookie_a, *cookie_b; 2561 2562 cookie_a = link->cookies + (addr_a - link->addrs); 2563 cookie_b = link->cookies + (addr_b - link->addrs); 2564 2565 /* swap addr_a/addr_b and cookie_a/cookie_b values */ 2566 swap(*addr_a, *addr_b); 2567 swap(*cookie_a, *cookie_b); 2568 } 2569 2570 static int bpf_kprobe_multi_addrs_cmp(const void *a, const void *b) 2571 { 2572 const unsigned long *addr_a = a, *addr_b = b; 2573 2574 if (*addr_a == *addr_b) 2575 return 0; 2576 return *addr_a < *addr_b ? -1 : 1; 2577 } 2578 2579 static int bpf_kprobe_multi_cookie_cmp(const void *a, const void *b, const void *priv) 2580 { 2581 return bpf_kprobe_multi_addrs_cmp(a, b); 2582 } 2583 2584 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx) 2585 { 2586 struct bpf_kprobe_multi_run_ctx *run_ctx; 2587 struct bpf_kprobe_multi_link *link; 2588 u64 *cookie, entry_ip; 2589 unsigned long *addr; 2590 2591 if (WARN_ON_ONCE(!ctx)) 2592 return 0; 2593 run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, run_ctx); 2594 link = run_ctx->link; 2595 if (!link->cookies) 2596 return 0; 2597 entry_ip = run_ctx->entry_ip; 2598 addr = bsearch(&entry_ip, link->addrs, link->cnt, sizeof(entry_ip), 2599 bpf_kprobe_multi_addrs_cmp); 2600 if (!addr) 2601 return 0; 2602 cookie = link->cookies + (addr - link->addrs); 2603 return *cookie; 2604 } 2605 2606 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 2607 { 2608 struct bpf_kprobe_multi_run_ctx *run_ctx; 2609 2610 run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, run_ctx); 2611 return run_ctx->entry_ip; 2612 } 2613 2614 static int 2615 kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link, 2616 unsigned long entry_ip, struct pt_regs *regs) 2617 { 2618 struct bpf_kprobe_multi_run_ctx run_ctx = { 2619 .link = link, 2620 .entry_ip = entry_ip, 2621 }; 2622 struct bpf_run_ctx *old_run_ctx; 2623 int err; 2624 2625 if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) { 2626 err = 0; 2627 goto out; 2628 } 2629 2630 migrate_disable(); 2631 rcu_read_lock(); 2632 old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx); 2633 err = bpf_prog_run(link->link.prog, regs); 2634 bpf_reset_run_ctx(old_run_ctx); 2635 rcu_read_unlock(); 2636 migrate_enable(); 2637 2638 out: 2639 __this_cpu_dec(bpf_prog_active); 2640 return err; 2641 } 2642 2643 static int 2644 kprobe_multi_link_handler(struct fprobe *fp, unsigned long fentry_ip, 2645 struct pt_regs *regs, void *data) 2646 { 2647 struct bpf_kprobe_multi_link *link; 2648 2649 link = container_of(fp, struct bpf_kprobe_multi_link, fp); 2650 kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), regs); 2651 return 0; 2652 } 2653 2654 static void 2655 kprobe_multi_link_exit_handler(struct fprobe *fp, unsigned long fentry_ip, 2656 struct pt_regs *regs, void *data) 2657 { 2658 struct bpf_kprobe_multi_link *link; 2659 2660 link = container_of(fp, struct bpf_kprobe_multi_link, fp); 2661 kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), regs); 2662 } 2663 2664 static int symbols_cmp_r(const void *a, const void *b, const void *priv) 2665 { 2666 const char **str_a = (const char **) a; 2667 const char **str_b = (const char **) b; 2668 2669 return strcmp(*str_a, *str_b); 2670 } 2671 2672 struct multi_symbols_sort { 2673 const char **funcs; 2674 u64 *cookies; 2675 }; 2676 2677 static void symbols_swap_r(void *a, void *b, int size, const void *priv) 2678 { 2679 const struct multi_symbols_sort *data = priv; 2680 const char **name_a = a, **name_b = b; 2681 2682 swap(*name_a, *name_b); 2683 2684 /* If defined, swap also related cookies. */ 2685 if (data->cookies) { 2686 u64 *cookie_a, *cookie_b; 2687 2688 cookie_a = data->cookies + (name_a - data->funcs); 2689 cookie_b = data->cookies + (name_b - data->funcs); 2690 swap(*cookie_a, *cookie_b); 2691 } 2692 } 2693 2694 struct modules_array { 2695 struct module **mods; 2696 int mods_cnt; 2697 int mods_cap; 2698 }; 2699 2700 static int add_module(struct modules_array *arr, struct module *mod) 2701 { 2702 struct module **mods; 2703 2704 if (arr->mods_cnt == arr->mods_cap) { 2705 arr->mods_cap = max(16, arr->mods_cap * 3 / 2); 2706 mods = krealloc_array(arr->mods, arr->mods_cap, sizeof(*mods), GFP_KERNEL); 2707 if (!mods) 2708 return -ENOMEM; 2709 arr->mods = mods; 2710 } 2711 2712 arr->mods[arr->mods_cnt] = mod; 2713 arr->mods_cnt++; 2714 return 0; 2715 } 2716 2717 static bool has_module(struct modules_array *arr, struct module *mod) 2718 { 2719 int i; 2720 2721 for (i = arr->mods_cnt - 1; i >= 0; i--) { 2722 if (arr->mods[i] == mod) 2723 return true; 2724 } 2725 return false; 2726 } 2727 2728 static int get_modules_for_addrs(struct module ***mods, unsigned long *addrs, u32 addrs_cnt) 2729 { 2730 struct modules_array arr = {}; 2731 u32 i, err = 0; 2732 2733 for (i = 0; i < addrs_cnt; i++) { 2734 struct module *mod; 2735 2736 preempt_disable(); 2737 mod = __module_address(addrs[i]); 2738 /* Either no module or we it's already stored */ 2739 if (!mod || has_module(&arr, mod)) { 2740 preempt_enable(); 2741 continue; 2742 } 2743 if (!try_module_get(mod)) 2744 err = -EINVAL; 2745 preempt_enable(); 2746 if (err) 2747 break; 2748 err = add_module(&arr, mod); 2749 if (err) { 2750 module_put(mod); 2751 break; 2752 } 2753 } 2754 2755 /* We return either err < 0 in case of error, ... */ 2756 if (err) { 2757 kprobe_multi_put_modules(arr.mods, arr.mods_cnt); 2758 kfree(arr.mods); 2759 return err; 2760 } 2761 2762 /* or number of modules found if everything is ok. */ 2763 *mods = arr.mods; 2764 return arr.mods_cnt; 2765 } 2766 2767 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 2768 { 2769 struct bpf_kprobe_multi_link *link = NULL; 2770 struct bpf_link_primer link_primer; 2771 void __user *ucookies; 2772 unsigned long *addrs; 2773 u32 flags, cnt, size; 2774 void __user *uaddrs; 2775 u64 *cookies = NULL; 2776 void __user *usyms; 2777 int err; 2778 2779 /* no support for 32bit archs yet */ 2780 if (sizeof(u64) != sizeof(void *)) 2781 return -EOPNOTSUPP; 2782 2783 if (prog->expected_attach_type != BPF_TRACE_KPROBE_MULTI) 2784 return -EINVAL; 2785 2786 flags = attr->link_create.kprobe_multi.flags; 2787 if (flags & ~BPF_F_KPROBE_MULTI_RETURN) 2788 return -EINVAL; 2789 2790 uaddrs = u64_to_user_ptr(attr->link_create.kprobe_multi.addrs); 2791 usyms = u64_to_user_ptr(attr->link_create.kprobe_multi.syms); 2792 if (!!uaddrs == !!usyms) 2793 return -EINVAL; 2794 2795 cnt = attr->link_create.kprobe_multi.cnt; 2796 if (!cnt) 2797 return -EINVAL; 2798 2799 size = cnt * sizeof(*addrs); 2800 addrs = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL); 2801 if (!addrs) 2802 return -ENOMEM; 2803 2804 ucookies = u64_to_user_ptr(attr->link_create.kprobe_multi.cookies); 2805 if (ucookies) { 2806 cookies = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL); 2807 if (!cookies) { 2808 err = -ENOMEM; 2809 goto error; 2810 } 2811 if (copy_from_user(cookies, ucookies, size)) { 2812 err = -EFAULT; 2813 goto error; 2814 } 2815 } 2816 2817 if (uaddrs) { 2818 if (copy_from_user(addrs, uaddrs, size)) { 2819 err = -EFAULT; 2820 goto error; 2821 } 2822 } else { 2823 struct multi_symbols_sort data = { 2824 .cookies = cookies, 2825 }; 2826 struct user_syms us; 2827 2828 err = copy_user_syms(&us, usyms, cnt); 2829 if (err) 2830 goto error; 2831 2832 if (cookies) 2833 data.funcs = us.syms; 2834 2835 sort_r(us.syms, cnt, sizeof(*us.syms), symbols_cmp_r, 2836 symbols_swap_r, &data); 2837 2838 err = ftrace_lookup_symbols(us.syms, cnt, addrs); 2839 free_user_syms(&us); 2840 if (err) 2841 goto error; 2842 } 2843 2844 link = kzalloc(sizeof(*link), GFP_KERNEL); 2845 if (!link) { 2846 err = -ENOMEM; 2847 goto error; 2848 } 2849 2850 bpf_link_init(&link->link, BPF_LINK_TYPE_KPROBE_MULTI, 2851 &bpf_kprobe_multi_link_lops, prog); 2852 2853 err = bpf_link_prime(&link->link, &link_primer); 2854 if (err) 2855 goto error; 2856 2857 if (flags & BPF_F_KPROBE_MULTI_RETURN) 2858 link->fp.exit_handler = kprobe_multi_link_exit_handler; 2859 else 2860 link->fp.entry_handler = kprobe_multi_link_handler; 2861 2862 link->addrs = addrs; 2863 link->cookies = cookies; 2864 link->cnt = cnt; 2865 2866 if (cookies) { 2867 /* 2868 * Sorting addresses will trigger sorting cookies as well 2869 * (check bpf_kprobe_multi_cookie_swap). This way we can 2870 * find cookie based on the address in bpf_get_attach_cookie 2871 * helper. 2872 */ 2873 sort_r(addrs, cnt, sizeof(*addrs), 2874 bpf_kprobe_multi_cookie_cmp, 2875 bpf_kprobe_multi_cookie_swap, 2876 link); 2877 } 2878 2879 err = get_modules_for_addrs(&link->mods, addrs, cnt); 2880 if (err < 0) { 2881 bpf_link_cleanup(&link_primer); 2882 return err; 2883 } 2884 link->mods_cnt = err; 2885 2886 err = register_fprobe_ips(&link->fp, addrs, cnt); 2887 if (err) { 2888 kprobe_multi_put_modules(link->mods, link->mods_cnt); 2889 bpf_link_cleanup(&link_primer); 2890 return err; 2891 } 2892 2893 return bpf_link_settle(&link_primer); 2894 2895 error: 2896 kfree(link); 2897 kvfree(addrs); 2898 kvfree(cookies); 2899 return err; 2900 } 2901 #else /* !CONFIG_FPROBE */ 2902 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 2903 { 2904 return -EOPNOTSUPP; 2905 } 2906 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx) 2907 { 2908 return 0; 2909 } 2910 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 2911 { 2912 return 0; 2913 } 2914 #endif 2915