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 #include <linux/namei.h> 27 28 #include <net/bpf_sk_storage.h> 29 30 #include <uapi/linux/bpf.h> 31 #include <uapi/linux/btf.h> 32 33 #include <asm/tlb.h> 34 35 #include "trace_probe.h" 36 #include "trace.h" 37 38 #define CREATE_TRACE_POINTS 39 #include "bpf_trace.h" 40 41 #define bpf_event_rcu_dereference(p) \ 42 rcu_dereference_protected(p, lockdep_is_held(&bpf_event_mutex)) 43 44 #ifdef CONFIG_MODULES 45 struct bpf_trace_module { 46 struct module *module; 47 struct list_head list; 48 }; 49 50 static LIST_HEAD(bpf_trace_modules); 51 static DEFINE_MUTEX(bpf_module_mutex); 52 53 static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name) 54 { 55 struct bpf_raw_event_map *btp, *ret = NULL; 56 struct bpf_trace_module *btm; 57 unsigned int i; 58 59 mutex_lock(&bpf_module_mutex); 60 list_for_each_entry(btm, &bpf_trace_modules, list) { 61 for (i = 0; i < btm->module->num_bpf_raw_events; ++i) { 62 btp = &btm->module->bpf_raw_events[i]; 63 if (!strcmp(btp->tp->name, name)) { 64 if (try_module_get(btm->module)) 65 ret = btp; 66 goto out; 67 } 68 } 69 } 70 out: 71 mutex_unlock(&bpf_module_mutex); 72 return ret; 73 } 74 #else 75 static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name) 76 { 77 return NULL; 78 } 79 #endif /* CONFIG_MODULES */ 80 81 u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); 82 u64 bpf_get_stack(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); 83 84 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size, 85 u64 flags, const struct btf **btf, 86 s32 *btf_id); 87 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx); 88 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx); 89 90 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx); 91 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx); 92 93 /** 94 * trace_call_bpf - invoke BPF program 95 * @call: tracepoint event 96 * @ctx: opaque context pointer 97 * 98 * kprobe handlers execute BPF programs via this helper. 99 * Can be used from static tracepoints in the future. 100 * 101 * Return: BPF programs always return an integer which is interpreted by 102 * kprobe handler as: 103 * 0 - return from kprobe (event is filtered out) 104 * 1 - store kprobe event into ring buffer 105 * Other values are reserved and currently alias to 1 106 */ 107 unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx) 108 { 109 unsigned int ret; 110 111 cant_sleep(); 112 113 if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) { 114 /* 115 * since some bpf program is already running on this cpu, 116 * don't call into another bpf program (same or different) 117 * and don't send kprobe event into ring-buffer, 118 * so return zero here 119 */ 120 rcu_read_lock(); 121 bpf_prog_inc_misses_counters(rcu_dereference(call->prog_array)); 122 rcu_read_unlock(); 123 ret = 0; 124 goto out; 125 } 126 127 /* 128 * Instead of moving rcu_read_lock/rcu_dereference/rcu_read_unlock 129 * to all call sites, we did a bpf_prog_array_valid() there to check 130 * whether call->prog_array is empty or not, which is 131 * a heuristic to speed up execution. 132 * 133 * If bpf_prog_array_valid() fetched prog_array was 134 * non-NULL, we go into trace_call_bpf() and do the actual 135 * proper rcu_dereference() under RCU lock. 136 * If it turns out that prog_array is NULL then, we bail out. 137 * For the opposite, if the bpf_prog_array_valid() fetched pointer 138 * was NULL, you'll skip the prog_array with the risk of missing 139 * out of events when it was updated in between this and the 140 * rcu_dereference() which is accepted risk. 141 */ 142 rcu_read_lock(); 143 ret = bpf_prog_run_array(rcu_dereference(call->prog_array), 144 ctx, bpf_prog_run); 145 rcu_read_unlock(); 146 147 out: 148 __this_cpu_dec(bpf_prog_active); 149 150 return ret; 151 } 152 153 #ifdef CONFIG_BPF_KPROBE_OVERRIDE 154 BPF_CALL_2(bpf_override_return, struct pt_regs *, regs, unsigned long, rc) 155 { 156 regs_set_return_value(regs, rc); 157 override_function_with_return(regs); 158 return 0; 159 } 160 161 static const struct bpf_func_proto bpf_override_return_proto = { 162 .func = bpf_override_return, 163 .gpl_only = true, 164 .ret_type = RET_INTEGER, 165 .arg1_type = ARG_PTR_TO_CTX, 166 .arg2_type = ARG_ANYTHING, 167 }; 168 #endif 169 170 static __always_inline int 171 bpf_probe_read_user_common(void *dst, u32 size, const void __user *unsafe_ptr) 172 { 173 int ret; 174 175 ret = copy_from_user_nofault(dst, unsafe_ptr, size); 176 if (unlikely(ret < 0)) 177 memset(dst, 0, size); 178 return ret; 179 } 180 181 BPF_CALL_3(bpf_probe_read_user, void *, dst, u32, size, 182 const void __user *, unsafe_ptr) 183 { 184 return bpf_probe_read_user_common(dst, size, unsafe_ptr); 185 } 186 187 const struct bpf_func_proto bpf_probe_read_user_proto = { 188 .func = bpf_probe_read_user, 189 .gpl_only = true, 190 .ret_type = RET_INTEGER, 191 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 192 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 193 .arg3_type = ARG_ANYTHING, 194 }; 195 196 static __always_inline int 197 bpf_probe_read_user_str_common(void *dst, u32 size, 198 const void __user *unsafe_ptr) 199 { 200 int ret; 201 202 /* 203 * NB: We rely on strncpy_from_user() not copying junk past the NUL 204 * terminator into `dst`. 205 * 206 * strncpy_from_user() does long-sized strides in the fast path. If the 207 * strncpy does not mask out the bytes after the NUL in `unsafe_ptr`, 208 * then there could be junk after the NUL in `dst`. If user takes `dst` 209 * and keys a hash map with it, then semantically identical strings can 210 * occupy multiple entries in the map. 211 */ 212 ret = strncpy_from_user_nofault(dst, unsafe_ptr, size); 213 if (unlikely(ret < 0)) 214 memset(dst, 0, size); 215 return ret; 216 } 217 218 BPF_CALL_3(bpf_probe_read_user_str, void *, dst, u32, size, 219 const void __user *, unsafe_ptr) 220 { 221 return bpf_probe_read_user_str_common(dst, size, unsafe_ptr); 222 } 223 224 const struct bpf_func_proto bpf_probe_read_user_str_proto = { 225 .func = bpf_probe_read_user_str, 226 .gpl_only = true, 227 .ret_type = RET_INTEGER, 228 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 229 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 230 .arg3_type = ARG_ANYTHING, 231 }; 232 233 BPF_CALL_3(bpf_probe_read_kernel, void *, dst, u32, size, 234 const void *, unsafe_ptr) 235 { 236 return bpf_probe_read_kernel_common(dst, size, unsafe_ptr); 237 } 238 239 const struct bpf_func_proto bpf_probe_read_kernel_proto = { 240 .func = bpf_probe_read_kernel, 241 .gpl_only = true, 242 .ret_type = RET_INTEGER, 243 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 244 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 245 .arg3_type = ARG_ANYTHING, 246 }; 247 248 static __always_inline int 249 bpf_probe_read_kernel_str_common(void *dst, u32 size, const void *unsafe_ptr) 250 { 251 int ret; 252 253 /* 254 * The strncpy_from_kernel_nofault() call will likely not fill the 255 * entire buffer, but that's okay in this circumstance as we're probing 256 * arbitrary memory anyway similar to bpf_probe_read_*() and might 257 * as well probe the stack. Thus, memory is explicitly cleared 258 * only in error case, so that improper users ignoring return 259 * code altogether don't copy garbage; otherwise length of string 260 * is returned that can be used for bpf_perf_event_output() et al. 261 */ 262 ret = strncpy_from_kernel_nofault(dst, unsafe_ptr, size); 263 if (unlikely(ret < 0)) 264 memset(dst, 0, size); 265 return ret; 266 } 267 268 BPF_CALL_3(bpf_probe_read_kernel_str, void *, dst, u32, size, 269 const void *, unsafe_ptr) 270 { 271 return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr); 272 } 273 274 const struct bpf_func_proto bpf_probe_read_kernel_str_proto = { 275 .func = bpf_probe_read_kernel_str, 276 .gpl_only = true, 277 .ret_type = RET_INTEGER, 278 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 279 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 280 .arg3_type = ARG_ANYTHING, 281 }; 282 283 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 284 BPF_CALL_3(bpf_probe_read_compat, void *, dst, u32, size, 285 const void *, unsafe_ptr) 286 { 287 if ((unsigned long)unsafe_ptr < TASK_SIZE) { 288 return bpf_probe_read_user_common(dst, size, 289 (__force void __user *)unsafe_ptr); 290 } 291 return bpf_probe_read_kernel_common(dst, size, unsafe_ptr); 292 } 293 294 static const struct bpf_func_proto bpf_probe_read_compat_proto = { 295 .func = bpf_probe_read_compat, 296 .gpl_only = true, 297 .ret_type = RET_INTEGER, 298 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 299 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 300 .arg3_type = ARG_ANYTHING, 301 }; 302 303 BPF_CALL_3(bpf_probe_read_compat_str, void *, dst, u32, size, 304 const void *, unsafe_ptr) 305 { 306 if ((unsigned long)unsafe_ptr < TASK_SIZE) { 307 return bpf_probe_read_user_str_common(dst, size, 308 (__force void __user *)unsafe_ptr); 309 } 310 return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr); 311 } 312 313 static const struct bpf_func_proto bpf_probe_read_compat_str_proto = { 314 .func = bpf_probe_read_compat_str, 315 .gpl_only = true, 316 .ret_type = RET_INTEGER, 317 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 318 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 319 .arg3_type = ARG_ANYTHING, 320 }; 321 #endif /* CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE */ 322 323 BPF_CALL_3(bpf_probe_write_user, void __user *, unsafe_ptr, const void *, src, 324 u32, size) 325 { 326 /* 327 * Ensure we're in user context which is safe for the helper to 328 * run. This helper has no business in a kthread. 329 * 330 * access_ok() should prevent writing to non-user memory, but in 331 * some situations (nommu, temporary switch, etc) access_ok() does 332 * not provide enough validation, hence the check on KERNEL_DS. 333 * 334 * nmi_uaccess_okay() ensures the probe is not run in an interim 335 * state, when the task or mm are switched. This is specifically 336 * required to prevent the use of temporary mm. 337 */ 338 339 if (unlikely(in_interrupt() || 340 current->flags & (PF_KTHREAD | PF_EXITING))) 341 return -EPERM; 342 if (unlikely(!nmi_uaccess_okay())) 343 return -EPERM; 344 345 return copy_to_user_nofault(unsafe_ptr, src, size); 346 } 347 348 static const struct bpf_func_proto bpf_probe_write_user_proto = { 349 .func = bpf_probe_write_user, 350 .gpl_only = true, 351 .ret_type = RET_INTEGER, 352 .arg1_type = ARG_ANYTHING, 353 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 354 .arg3_type = ARG_CONST_SIZE, 355 }; 356 357 static const struct bpf_func_proto *bpf_get_probe_write_proto(void) 358 { 359 if (!capable(CAP_SYS_ADMIN)) 360 return NULL; 361 362 pr_warn_ratelimited("%s[%d] is installing a program with bpf_probe_write_user helper that may corrupt user memory!", 363 current->comm, task_pid_nr(current)); 364 365 return &bpf_probe_write_user_proto; 366 } 367 368 #define MAX_TRACE_PRINTK_VARARGS 3 369 #define BPF_TRACE_PRINTK_SIZE 1024 370 371 BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1, 372 u64, arg2, u64, arg3) 373 { 374 u64 args[MAX_TRACE_PRINTK_VARARGS] = { arg1, arg2, arg3 }; 375 struct bpf_bprintf_data data = { 376 .get_bin_args = true, 377 .get_buf = true, 378 }; 379 int ret; 380 381 ret = bpf_bprintf_prepare(fmt, fmt_size, args, 382 MAX_TRACE_PRINTK_VARARGS, &data); 383 if (ret < 0) 384 return ret; 385 386 ret = bstr_printf(data.buf, MAX_BPRINTF_BUF, fmt, data.bin_args); 387 388 trace_bpf_trace_printk(data.buf); 389 390 bpf_bprintf_cleanup(&data); 391 392 return ret; 393 } 394 395 static const struct bpf_func_proto bpf_trace_printk_proto = { 396 .func = bpf_trace_printk, 397 .gpl_only = true, 398 .ret_type = RET_INTEGER, 399 .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY, 400 .arg2_type = ARG_CONST_SIZE, 401 }; 402 403 static void __set_printk_clr_event(void) 404 { 405 /* 406 * This program might be calling bpf_trace_printk, 407 * so enable the associated bpf_trace/bpf_trace_printk event. 408 * Repeat this each time as it is possible a user has 409 * disabled bpf_trace_printk events. By loading a program 410 * calling bpf_trace_printk() however the user has expressed 411 * the intent to see such events. 412 */ 413 if (trace_set_clr_event("bpf_trace", "bpf_trace_printk", 1)) 414 pr_warn_ratelimited("could not enable bpf_trace_printk events"); 415 } 416 417 const struct bpf_func_proto *bpf_get_trace_printk_proto(void) 418 { 419 __set_printk_clr_event(); 420 return &bpf_trace_printk_proto; 421 } 422 423 BPF_CALL_4(bpf_trace_vprintk, char *, fmt, u32, fmt_size, const void *, args, 424 u32, data_len) 425 { 426 struct bpf_bprintf_data data = { 427 .get_bin_args = true, 428 .get_buf = true, 429 }; 430 int ret, num_args; 431 432 if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 || 433 (data_len && !args)) 434 return -EINVAL; 435 num_args = data_len / 8; 436 437 ret = bpf_bprintf_prepare(fmt, fmt_size, args, num_args, &data); 438 if (ret < 0) 439 return ret; 440 441 ret = bstr_printf(data.buf, MAX_BPRINTF_BUF, fmt, data.bin_args); 442 443 trace_bpf_trace_printk(data.buf); 444 445 bpf_bprintf_cleanup(&data); 446 447 return ret; 448 } 449 450 static const struct bpf_func_proto bpf_trace_vprintk_proto = { 451 .func = bpf_trace_vprintk, 452 .gpl_only = true, 453 .ret_type = RET_INTEGER, 454 .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY, 455 .arg2_type = ARG_CONST_SIZE, 456 .arg3_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY, 457 .arg4_type = ARG_CONST_SIZE_OR_ZERO, 458 }; 459 460 const struct bpf_func_proto *bpf_get_trace_vprintk_proto(void) 461 { 462 __set_printk_clr_event(); 463 return &bpf_trace_vprintk_proto; 464 } 465 466 BPF_CALL_5(bpf_seq_printf, struct seq_file *, m, char *, fmt, u32, fmt_size, 467 const void *, args, u32, data_len) 468 { 469 struct bpf_bprintf_data data = { 470 .get_bin_args = true, 471 }; 472 int err, num_args; 473 474 if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 || 475 (data_len && !args)) 476 return -EINVAL; 477 num_args = data_len / 8; 478 479 err = bpf_bprintf_prepare(fmt, fmt_size, args, num_args, &data); 480 if (err < 0) 481 return err; 482 483 seq_bprintf(m, fmt, data.bin_args); 484 485 bpf_bprintf_cleanup(&data); 486 487 return seq_has_overflowed(m) ? -EOVERFLOW : 0; 488 } 489 490 BTF_ID_LIST_SINGLE(btf_seq_file_ids, struct, seq_file) 491 492 static const struct bpf_func_proto bpf_seq_printf_proto = { 493 .func = bpf_seq_printf, 494 .gpl_only = true, 495 .ret_type = RET_INTEGER, 496 .arg1_type = ARG_PTR_TO_BTF_ID, 497 .arg1_btf_id = &btf_seq_file_ids[0], 498 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 499 .arg3_type = ARG_CONST_SIZE, 500 .arg4_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY, 501 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 502 }; 503 504 BPF_CALL_3(bpf_seq_write, struct seq_file *, m, const void *, data, u32, len) 505 { 506 return seq_write(m, data, len) ? -EOVERFLOW : 0; 507 } 508 509 static const struct bpf_func_proto bpf_seq_write_proto = { 510 .func = bpf_seq_write, 511 .gpl_only = true, 512 .ret_type = RET_INTEGER, 513 .arg1_type = ARG_PTR_TO_BTF_ID, 514 .arg1_btf_id = &btf_seq_file_ids[0], 515 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 516 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 517 }; 518 519 BPF_CALL_4(bpf_seq_printf_btf, struct seq_file *, m, struct btf_ptr *, ptr, 520 u32, btf_ptr_size, u64, flags) 521 { 522 const struct btf *btf; 523 s32 btf_id; 524 int ret; 525 526 ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id); 527 if (ret) 528 return ret; 529 530 return btf_type_seq_show_flags(btf, btf_id, ptr->ptr, m, flags); 531 } 532 533 static const struct bpf_func_proto bpf_seq_printf_btf_proto = { 534 .func = bpf_seq_printf_btf, 535 .gpl_only = true, 536 .ret_type = RET_INTEGER, 537 .arg1_type = ARG_PTR_TO_BTF_ID, 538 .arg1_btf_id = &btf_seq_file_ids[0], 539 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 540 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 541 .arg4_type = ARG_ANYTHING, 542 }; 543 544 static __always_inline int 545 get_map_perf_counter(struct bpf_map *map, u64 flags, 546 u64 *value, u64 *enabled, u64 *running) 547 { 548 struct bpf_array *array = container_of(map, struct bpf_array, map); 549 unsigned int cpu = smp_processor_id(); 550 u64 index = flags & BPF_F_INDEX_MASK; 551 struct bpf_event_entry *ee; 552 553 if (unlikely(flags & ~(BPF_F_INDEX_MASK))) 554 return -EINVAL; 555 if (index == BPF_F_CURRENT_CPU) 556 index = cpu; 557 if (unlikely(index >= array->map.max_entries)) 558 return -E2BIG; 559 560 ee = READ_ONCE(array->ptrs[index]); 561 if (!ee) 562 return -ENOENT; 563 564 return perf_event_read_local(ee->event, value, enabled, running); 565 } 566 567 BPF_CALL_2(bpf_perf_event_read, struct bpf_map *, map, u64, flags) 568 { 569 u64 value = 0; 570 int err; 571 572 err = get_map_perf_counter(map, flags, &value, NULL, NULL); 573 /* 574 * this api is ugly since we miss [-22..-2] range of valid 575 * counter values, but that's uapi 576 */ 577 if (err) 578 return err; 579 return value; 580 } 581 582 static const struct bpf_func_proto bpf_perf_event_read_proto = { 583 .func = bpf_perf_event_read, 584 .gpl_only = true, 585 .ret_type = RET_INTEGER, 586 .arg1_type = ARG_CONST_MAP_PTR, 587 .arg2_type = ARG_ANYTHING, 588 }; 589 590 BPF_CALL_4(bpf_perf_event_read_value, struct bpf_map *, map, u64, flags, 591 struct bpf_perf_event_value *, buf, u32, size) 592 { 593 int err = -EINVAL; 594 595 if (unlikely(size != sizeof(struct bpf_perf_event_value))) 596 goto clear; 597 err = get_map_perf_counter(map, flags, &buf->counter, &buf->enabled, 598 &buf->running); 599 if (unlikely(err)) 600 goto clear; 601 return 0; 602 clear: 603 memset(buf, 0, size); 604 return err; 605 } 606 607 static const struct bpf_func_proto bpf_perf_event_read_value_proto = { 608 .func = bpf_perf_event_read_value, 609 .gpl_only = true, 610 .ret_type = RET_INTEGER, 611 .arg1_type = ARG_CONST_MAP_PTR, 612 .arg2_type = ARG_ANYTHING, 613 .arg3_type = ARG_PTR_TO_UNINIT_MEM, 614 .arg4_type = ARG_CONST_SIZE, 615 }; 616 617 static __always_inline u64 618 __bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map, 619 u64 flags, struct perf_sample_data *sd) 620 { 621 struct bpf_array *array = container_of(map, struct bpf_array, map); 622 unsigned int cpu = smp_processor_id(); 623 u64 index = flags & BPF_F_INDEX_MASK; 624 struct bpf_event_entry *ee; 625 struct perf_event *event; 626 627 if (index == BPF_F_CURRENT_CPU) 628 index = cpu; 629 if (unlikely(index >= array->map.max_entries)) 630 return -E2BIG; 631 632 ee = READ_ONCE(array->ptrs[index]); 633 if (!ee) 634 return -ENOENT; 635 636 event = ee->event; 637 if (unlikely(event->attr.type != PERF_TYPE_SOFTWARE || 638 event->attr.config != PERF_COUNT_SW_BPF_OUTPUT)) 639 return -EINVAL; 640 641 if (unlikely(event->oncpu != cpu)) 642 return -EOPNOTSUPP; 643 644 return perf_event_output(event, sd, regs); 645 } 646 647 /* 648 * Support executing tracepoints in normal, irq, and nmi context that each call 649 * bpf_perf_event_output 650 */ 651 struct bpf_trace_sample_data { 652 struct perf_sample_data sds[3]; 653 }; 654 655 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_trace_sds); 656 static DEFINE_PER_CPU(int, bpf_trace_nest_level); 657 BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map, 658 u64, flags, void *, data, u64, size) 659 { 660 struct bpf_trace_sample_data *sds; 661 struct perf_raw_record raw = { 662 .frag = { 663 .size = size, 664 .data = data, 665 }, 666 }; 667 struct perf_sample_data *sd; 668 int nest_level, err; 669 670 preempt_disable(); 671 sds = this_cpu_ptr(&bpf_trace_sds); 672 nest_level = this_cpu_inc_return(bpf_trace_nest_level); 673 674 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(sds->sds))) { 675 err = -EBUSY; 676 goto out; 677 } 678 679 sd = &sds->sds[nest_level - 1]; 680 681 if (unlikely(flags & ~(BPF_F_INDEX_MASK))) { 682 err = -EINVAL; 683 goto out; 684 } 685 686 perf_sample_data_init(sd, 0, 0); 687 perf_sample_save_raw_data(sd, &raw); 688 689 err = __bpf_perf_event_output(regs, map, flags, sd); 690 out: 691 this_cpu_dec(bpf_trace_nest_level); 692 preempt_enable(); 693 return err; 694 } 695 696 static const struct bpf_func_proto bpf_perf_event_output_proto = { 697 .func = bpf_perf_event_output, 698 .gpl_only = true, 699 .ret_type = RET_INTEGER, 700 .arg1_type = ARG_PTR_TO_CTX, 701 .arg2_type = ARG_CONST_MAP_PTR, 702 .arg3_type = ARG_ANYTHING, 703 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, 704 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 705 }; 706 707 static DEFINE_PER_CPU(int, bpf_event_output_nest_level); 708 struct bpf_nested_pt_regs { 709 struct pt_regs regs[3]; 710 }; 711 static DEFINE_PER_CPU(struct bpf_nested_pt_regs, bpf_pt_regs); 712 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_misc_sds); 713 714 u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size, 715 void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy) 716 { 717 struct perf_raw_frag frag = { 718 .copy = ctx_copy, 719 .size = ctx_size, 720 .data = ctx, 721 }; 722 struct perf_raw_record raw = { 723 .frag = { 724 { 725 .next = ctx_size ? &frag : NULL, 726 }, 727 .size = meta_size, 728 .data = meta, 729 }, 730 }; 731 struct perf_sample_data *sd; 732 struct pt_regs *regs; 733 int nest_level; 734 u64 ret; 735 736 preempt_disable(); 737 nest_level = this_cpu_inc_return(bpf_event_output_nest_level); 738 739 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(bpf_misc_sds.sds))) { 740 ret = -EBUSY; 741 goto out; 742 } 743 sd = this_cpu_ptr(&bpf_misc_sds.sds[nest_level - 1]); 744 regs = this_cpu_ptr(&bpf_pt_regs.regs[nest_level - 1]); 745 746 perf_fetch_caller_regs(regs); 747 perf_sample_data_init(sd, 0, 0); 748 perf_sample_save_raw_data(sd, &raw); 749 750 ret = __bpf_perf_event_output(regs, map, flags, sd); 751 out: 752 this_cpu_dec(bpf_event_output_nest_level); 753 preempt_enable(); 754 return ret; 755 } 756 757 BPF_CALL_0(bpf_get_current_task) 758 { 759 return (long) current; 760 } 761 762 const struct bpf_func_proto bpf_get_current_task_proto = { 763 .func = bpf_get_current_task, 764 .gpl_only = true, 765 .ret_type = RET_INTEGER, 766 }; 767 768 BPF_CALL_0(bpf_get_current_task_btf) 769 { 770 return (unsigned long) current; 771 } 772 773 const struct bpf_func_proto bpf_get_current_task_btf_proto = { 774 .func = bpf_get_current_task_btf, 775 .gpl_only = true, 776 .ret_type = RET_PTR_TO_BTF_ID_TRUSTED, 777 .ret_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK], 778 }; 779 780 BPF_CALL_1(bpf_task_pt_regs, struct task_struct *, task) 781 { 782 return (unsigned long) task_pt_regs(task); 783 } 784 785 BTF_ID_LIST(bpf_task_pt_regs_ids) 786 BTF_ID(struct, pt_regs) 787 788 const struct bpf_func_proto bpf_task_pt_regs_proto = { 789 .func = bpf_task_pt_regs, 790 .gpl_only = true, 791 .arg1_type = ARG_PTR_TO_BTF_ID, 792 .arg1_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK], 793 .ret_type = RET_PTR_TO_BTF_ID, 794 .ret_btf_id = &bpf_task_pt_regs_ids[0], 795 }; 796 797 BPF_CALL_2(bpf_current_task_under_cgroup, struct bpf_map *, map, u32, idx) 798 { 799 struct bpf_array *array = container_of(map, struct bpf_array, map); 800 struct cgroup *cgrp; 801 802 if (unlikely(idx >= array->map.max_entries)) 803 return -E2BIG; 804 805 cgrp = READ_ONCE(array->ptrs[idx]); 806 if (unlikely(!cgrp)) 807 return -EAGAIN; 808 809 return task_under_cgroup_hierarchy(current, cgrp); 810 } 811 812 static const struct bpf_func_proto bpf_current_task_under_cgroup_proto = { 813 .func = bpf_current_task_under_cgroup, 814 .gpl_only = false, 815 .ret_type = RET_INTEGER, 816 .arg1_type = ARG_CONST_MAP_PTR, 817 .arg2_type = ARG_ANYTHING, 818 }; 819 820 struct send_signal_irq_work { 821 struct irq_work irq_work; 822 struct task_struct *task; 823 u32 sig; 824 enum pid_type type; 825 }; 826 827 static DEFINE_PER_CPU(struct send_signal_irq_work, send_signal_work); 828 829 static void do_bpf_send_signal(struct irq_work *entry) 830 { 831 struct send_signal_irq_work *work; 832 833 work = container_of(entry, struct send_signal_irq_work, irq_work); 834 group_send_sig_info(work->sig, SEND_SIG_PRIV, work->task, work->type); 835 put_task_struct(work->task); 836 } 837 838 static int bpf_send_signal_common(u32 sig, enum pid_type type) 839 { 840 struct send_signal_irq_work *work = NULL; 841 842 /* Similar to bpf_probe_write_user, task needs to be 843 * in a sound condition and kernel memory access be 844 * permitted in order to send signal to the current 845 * task. 846 */ 847 if (unlikely(current->flags & (PF_KTHREAD | PF_EXITING))) 848 return -EPERM; 849 if (unlikely(!nmi_uaccess_okay())) 850 return -EPERM; 851 /* Task should not be pid=1 to avoid kernel panic. */ 852 if (unlikely(is_global_init(current))) 853 return -EPERM; 854 855 if (irqs_disabled()) { 856 /* Do an early check on signal validity. Otherwise, 857 * the error is lost in deferred irq_work. 858 */ 859 if (unlikely(!valid_signal(sig))) 860 return -EINVAL; 861 862 work = this_cpu_ptr(&send_signal_work); 863 if (irq_work_is_busy(&work->irq_work)) 864 return -EBUSY; 865 866 /* Add the current task, which is the target of sending signal, 867 * to the irq_work. The current task may change when queued 868 * irq works get executed. 869 */ 870 work->task = get_task_struct(current); 871 work->sig = sig; 872 work->type = type; 873 irq_work_queue(&work->irq_work); 874 return 0; 875 } 876 877 return group_send_sig_info(sig, SEND_SIG_PRIV, current, type); 878 } 879 880 BPF_CALL_1(bpf_send_signal, u32, sig) 881 { 882 return bpf_send_signal_common(sig, PIDTYPE_TGID); 883 } 884 885 static const struct bpf_func_proto bpf_send_signal_proto = { 886 .func = bpf_send_signal, 887 .gpl_only = false, 888 .ret_type = RET_INTEGER, 889 .arg1_type = ARG_ANYTHING, 890 }; 891 892 BPF_CALL_1(bpf_send_signal_thread, u32, sig) 893 { 894 return bpf_send_signal_common(sig, PIDTYPE_PID); 895 } 896 897 static const struct bpf_func_proto bpf_send_signal_thread_proto = { 898 .func = bpf_send_signal_thread, 899 .gpl_only = false, 900 .ret_type = RET_INTEGER, 901 .arg1_type = ARG_ANYTHING, 902 }; 903 904 BPF_CALL_3(bpf_d_path, struct path *, path, char *, buf, u32, sz) 905 { 906 struct path copy; 907 long len; 908 char *p; 909 910 if (!sz) 911 return 0; 912 913 /* 914 * The path pointer is verified as trusted and safe to use, 915 * but let's double check it's valid anyway to workaround 916 * potentially broken verifier. 917 */ 918 len = copy_from_kernel_nofault(©, path, sizeof(*path)); 919 if (len < 0) 920 return len; 921 922 p = d_path(©, buf, sz); 923 if (IS_ERR(p)) { 924 len = PTR_ERR(p); 925 } else { 926 len = buf + sz - p; 927 memmove(buf, p, len); 928 } 929 930 return len; 931 } 932 933 BTF_SET_START(btf_allowlist_d_path) 934 #ifdef CONFIG_SECURITY 935 BTF_ID(func, security_file_permission) 936 BTF_ID(func, security_inode_getattr) 937 BTF_ID(func, security_file_open) 938 #endif 939 #ifdef CONFIG_SECURITY_PATH 940 BTF_ID(func, security_path_truncate) 941 #endif 942 BTF_ID(func, vfs_truncate) 943 BTF_ID(func, vfs_fallocate) 944 BTF_ID(func, dentry_open) 945 BTF_ID(func, vfs_getattr) 946 BTF_ID(func, filp_close) 947 BTF_SET_END(btf_allowlist_d_path) 948 949 static bool bpf_d_path_allowed(const struct bpf_prog *prog) 950 { 951 if (prog->type == BPF_PROG_TYPE_TRACING && 952 prog->expected_attach_type == BPF_TRACE_ITER) 953 return true; 954 955 if (prog->type == BPF_PROG_TYPE_LSM) 956 return bpf_lsm_is_sleepable_hook(prog->aux->attach_btf_id); 957 958 return btf_id_set_contains(&btf_allowlist_d_path, 959 prog->aux->attach_btf_id); 960 } 961 962 BTF_ID_LIST_SINGLE(bpf_d_path_btf_ids, struct, path) 963 964 static const struct bpf_func_proto bpf_d_path_proto = { 965 .func = bpf_d_path, 966 .gpl_only = false, 967 .ret_type = RET_INTEGER, 968 .arg1_type = ARG_PTR_TO_BTF_ID, 969 .arg1_btf_id = &bpf_d_path_btf_ids[0], 970 .arg2_type = ARG_PTR_TO_MEM, 971 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 972 .allowed = bpf_d_path_allowed, 973 }; 974 975 #define BTF_F_ALL (BTF_F_COMPACT | BTF_F_NONAME | \ 976 BTF_F_PTR_RAW | BTF_F_ZERO) 977 978 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size, 979 u64 flags, const struct btf **btf, 980 s32 *btf_id) 981 { 982 const struct btf_type *t; 983 984 if (unlikely(flags & ~(BTF_F_ALL))) 985 return -EINVAL; 986 987 if (btf_ptr_size != sizeof(struct btf_ptr)) 988 return -EINVAL; 989 990 *btf = bpf_get_btf_vmlinux(); 991 992 if (IS_ERR_OR_NULL(*btf)) 993 return IS_ERR(*btf) ? PTR_ERR(*btf) : -EINVAL; 994 995 if (ptr->type_id > 0) 996 *btf_id = ptr->type_id; 997 else 998 return -EINVAL; 999 1000 if (*btf_id > 0) 1001 t = btf_type_by_id(*btf, *btf_id); 1002 if (*btf_id <= 0 || !t) 1003 return -ENOENT; 1004 1005 return 0; 1006 } 1007 1008 BPF_CALL_5(bpf_snprintf_btf, char *, str, u32, str_size, struct btf_ptr *, ptr, 1009 u32, btf_ptr_size, u64, flags) 1010 { 1011 const struct btf *btf; 1012 s32 btf_id; 1013 int ret; 1014 1015 ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id); 1016 if (ret) 1017 return ret; 1018 1019 return btf_type_snprintf_show(btf, btf_id, ptr->ptr, str, str_size, 1020 flags); 1021 } 1022 1023 const struct bpf_func_proto bpf_snprintf_btf_proto = { 1024 .func = bpf_snprintf_btf, 1025 .gpl_only = false, 1026 .ret_type = RET_INTEGER, 1027 .arg1_type = ARG_PTR_TO_MEM, 1028 .arg2_type = ARG_CONST_SIZE, 1029 .arg3_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1030 .arg4_type = ARG_CONST_SIZE, 1031 .arg5_type = ARG_ANYTHING, 1032 }; 1033 1034 BPF_CALL_1(bpf_get_func_ip_tracing, void *, ctx) 1035 { 1036 /* This helper call is inlined by verifier. */ 1037 return ((u64 *)ctx)[-2]; 1038 } 1039 1040 static const struct bpf_func_proto bpf_get_func_ip_proto_tracing = { 1041 .func = bpf_get_func_ip_tracing, 1042 .gpl_only = true, 1043 .ret_type = RET_INTEGER, 1044 .arg1_type = ARG_PTR_TO_CTX, 1045 }; 1046 1047 #ifdef CONFIG_X86_KERNEL_IBT 1048 static unsigned long get_entry_ip(unsigned long fentry_ip) 1049 { 1050 u32 instr; 1051 1052 /* Being extra safe in here in case entry ip is on the page-edge. */ 1053 if (get_kernel_nofault(instr, (u32 *) fentry_ip - 1)) 1054 return fentry_ip; 1055 if (is_endbr(instr)) 1056 fentry_ip -= ENDBR_INSN_SIZE; 1057 return fentry_ip; 1058 } 1059 #else 1060 #define get_entry_ip(fentry_ip) fentry_ip 1061 #endif 1062 1063 BPF_CALL_1(bpf_get_func_ip_kprobe, struct pt_regs *, regs) 1064 { 1065 struct bpf_trace_run_ctx *run_ctx __maybe_unused; 1066 struct kprobe *kp; 1067 1068 #ifdef CONFIG_UPROBES 1069 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); 1070 if (run_ctx->is_uprobe) 1071 return ((struct uprobe_dispatch_data *)current->utask->vaddr)->bp_addr; 1072 #endif 1073 1074 kp = kprobe_running(); 1075 1076 if (!kp || !(kp->flags & KPROBE_FLAG_ON_FUNC_ENTRY)) 1077 return 0; 1078 1079 return get_entry_ip((uintptr_t)kp->addr); 1080 } 1081 1082 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe = { 1083 .func = bpf_get_func_ip_kprobe, 1084 .gpl_only = true, 1085 .ret_type = RET_INTEGER, 1086 .arg1_type = ARG_PTR_TO_CTX, 1087 }; 1088 1089 BPF_CALL_1(bpf_get_func_ip_kprobe_multi, struct pt_regs *, regs) 1090 { 1091 return bpf_kprobe_multi_entry_ip(current->bpf_ctx); 1092 } 1093 1094 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe_multi = { 1095 .func = bpf_get_func_ip_kprobe_multi, 1096 .gpl_only = false, 1097 .ret_type = RET_INTEGER, 1098 .arg1_type = ARG_PTR_TO_CTX, 1099 }; 1100 1101 BPF_CALL_1(bpf_get_attach_cookie_kprobe_multi, struct pt_regs *, regs) 1102 { 1103 return bpf_kprobe_multi_cookie(current->bpf_ctx); 1104 } 1105 1106 static const struct bpf_func_proto bpf_get_attach_cookie_proto_kmulti = { 1107 .func = bpf_get_attach_cookie_kprobe_multi, 1108 .gpl_only = false, 1109 .ret_type = RET_INTEGER, 1110 .arg1_type = ARG_PTR_TO_CTX, 1111 }; 1112 1113 BPF_CALL_1(bpf_get_func_ip_uprobe_multi, struct pt_regs *, regs) 1114 { 1115 return bpf_uprobe_multi_entry_ip(current->bpf_ctx); 1116 } 1117 1118 static const struct bpf_func_proto bpf_get_func_ip_proto_uprobe_multi = { 1119 .func = bpf_get_func_ip_uprobe_multi, 1120 .gpl_only = false, 1121 .ret_type = RET_INTEGER, 1122 .arg1_type = ARG_PTR_TO_CTX, 1123 }; 1124 1125 BPF_CALL_1(bpf_get_attach_cookie_uprobe_multi, struct pt_regs *, regs) 1126 { 1127 return bpf_uprobe_multi_cookie(current->bpf_ctx); 1128 } 1129 1130 static const struct bpf_func_proto bpf_get_attach_cookie_proto_umulti = { 1131 .func = bpf_get_attach_cookie_uprobe_multi, 1132 .gpl_only = false, 1133 .ret_type = RET_INTEGER, 1134 .arg1_type = ARG_PTR_TO_CTX, 1135 }; 1136 1137 BPF_CALL_1(bpf_get_attach_cookie_trace, void *, ctx) 1138 { 1139 struct bpf_trace_run_ctx *run_ctx; 1140 1141 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); 1142 return run_ctx->bpf_cookie; 1143 } 1144 1145 static const struct bpf_func_proto bpf_get_attach_cookie_proto_trace = { 1146 .func = bpf_get_attach_cookie_trace, 1147 .gpl_only = false, 1148 .ret_type = RET_INTEGER, 1149 .arg1_type = ARG_PTR_TO_CTX, 1150 }; 1151 1152 BPF_CALL_1(bpf_get_attach_cookie_pe, struct bpf_perf_event_data_kern *, ctx) 1153 { 1154 return ctx->event->bpf_cookie; 1155 } 1156 1157 static const struct bpf_func_proto bpf_get_attach_cookie_proto_pe = { 1158 .func = bpf_get_attach_cookie_pe, 1159 .gpl_only = false, 1160 .ret_type = RET_INTEGER, 1161 .arg1_type = ARG_PTR_TO_CTX, 1162 }; 1163 1164 BPF_CALL_1(bpf_get_attach_cookie_tracing, void *, ctx) 1165 { 1166 struct bpf_trace_run_ctx *run_ctx; 1167 1168 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); 1169 return run_ctx->bpf_cookie; 1170 } 1171 1172 static const struct bpf_func_proto bpf_get_attach_cookie_proto_tracing = { 1173 .func = bpf_get_attach_cookie_tracing, 1174 .gpl_only = false, 1175 .ret_type = RET_INTEGER, 1176 .arg1_type = ARG_PTR_TO_CTX, 1177 }; 1178 1179 BPF_CALL_3(bpf_get_branch_snapshot, void *, buf, u32, size, u64, flags) 1180 { 1181 #ifndef CONFIG_X86 1182 return -ENOENT; 1183 #else 1184 static const u32 br_entry_size = sizeof(struct perf_branch_entry); 1185 u32 entry_cnt = size / br_entry_size; 1186 1187 entry_cnt = static_call(perf_snapshot_branch_stack)(buf, entry_cnt); 1188 1189 if (unlikely(flags)) 1190 return -EINVAL; 1191 1192 if (!entry_cnt) 1193 return -ENOENT; 1194 1195 return entry_cnt * br_entry_size; 1196 #endif 1197 } 1198 1199 static const struct bpf_func_proto bpf_get_branch_snapshot_proto = { 1200 .func = bpf_get_branch_snapshot, 1201 .gpl_only = true, 1202 .ret_type = RET_INTEGER, 1203 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 1204 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 1205 }; 1206 1207 BPF_CALL_3(get_func_arg, void *, ctx, u32, n, u64 *, value) 1208 { 1209 /* This helper call is inlined by verifier. */ 1210 u64 nr_args = ((u64 *)ctx)[-1]; 1211 1212 if ((u64) n >= nr_args) 1213 return -EINVAL; 1214 *value = ((u64 *)ctx)[n]; 1215 return 0; 1216 } 1217 1218 static const struct bpf_func_proto bpf_get_func_arg_proto = { 1219 .func = get_func_arg, 1220 .ret_type = RET_INTEGER, 1221 .arg1_type = ARG_PTR_TO_CTX, 1222 .arg2_type = ARG_ANYTHING, 1223 .arg3_type = ARG_PTR_TO_LONG, 1224 }; 1225 1226 BPF_CALL_2(get_func_ret, void *, ctx, u64 *, value) 1227 { 1228 /* This helper call is inlined by verifier. */ 1229 u64 nr_args = ((u64 *)ctx)[-1]; 1230 1231 *value = ((u64 *)ctx)[nr_args]; 1232 return 0; 1233 } 1234 1235 static const struct bpf_func_proto bpf_get_func_ret_proto = { 1236 .func = get_func_ret, 1237 .ret_type = RET_INTEGER, 1238 .arg1_type = ARG_PTR_TO_CTX, 1239 .arg2_type = ARG_PTR_TO_LONG, 1240 }; 1241 1242 BPF_CALL_1(get_func_arg_cnt, void *, ctx) 1243 { 1244 /* This helper call is inlined by verifier. */ 1245 return ((u64 *)ctx)[-1]; 1246 } 1247 1248 static const struct bpf_func_proto bpf_get_func_arg_cnt_proto = { 1249 .func = get_func_arg_cnt, 1250 .ret_type = RET_INTEGER, 1251 .arg1_type = ARG_PTR_TO_CTX, 1252 }; 1253 1254 #ifdef CONFIG_KEYS 1255 __diag_push(); 1256 __diag_ignore_all("-Wmissing-prototypes", 1257 "kfuncs which will be used in BPF programs"); 1258 1259 /** 1260 * bpf_lookup_user_key - lookup a key by its serial 1261 * @serial: key handle serial number 1262 * @flags: lookup-specific flags 1263 * 1264 * Search a key with a given *serial* and the provided *flags*. 1265 * If found, increment the reference count of the key by one, and 1266 * return it in the bpf_key structure. 1267 * 1268 * The bpf_key structure must be passed to bpf_key_put() when done 1269 * with it, so that the key reference count is decremented and the 1270 * bpf_key structure is freed. 1271 * 1272 * Permission checks are deferred to the time the key is used by 1273 * one of the available key-specific kfuncs. 1274 * 1275 * Set *flags* with KEY_LOOKUP_CREATE, to attempt creating a requested 1276 * special keyring (e.g. session keyring), if it doesn't yet exist. 1277 * Set *flags* with KEY_LOOKUP_PARTIAL, to lookup a key without waiting 1278 * for the key construction, and to retrieve uninstantiated keys (keys 1279 * without data attached to them). 1280 * 1281 * Return: a bpf_key pointer with a valid key pointer if the key is found, a 1282 * NULL pointer otherwise. 1283 */ 1284 __bpf_kfunc struct bpf_key *bpf_lookup_user_key(u32 serial, u64 flags) 1285 { 1286 key_ref_t key_ref; 1287 struct bpf_key *bkey; 1288 1289 if (flags & ~KEY_LOOKUP_ALL) 1290 return NULL; 1291 1292 /* 1293 * Permission check is deferred until the key is used, as the 1294 * intent of the caller is unknown here. 1295 */ 1296 key_ref = lookup_user_key(serial, flags, KEY_DEFER_PERM_CHECK); 1297 if (IS_ERR(key_ref)) 1298 return NULL; 1299 1300 bkey = kmalloc(sizeof(*bkey), GFP_KERNEL); 1301 if (!bkey) { 1302 key_put(key_ref_to_ptr(key_ref)); 1303 return NULL; 1304 } 1305 1306 bkey->key = key_ref_to_ptr(key_ref); 1307 bkey->has_ref = true; 1308 1309 return bkey; 1310 } 1311 1312 /** 1313 * bpf_lookup_system_key - lookup a key by a system-defined ID 1314 * @id: key ID 1315 * 1316 * Obtain a bpf_key structure with a key pointer set to the passed key ID. 1317 * The key pointer is marked as invalid, to prevent bpf_key_put() from 1318 * attempting to decrement the key reference count on that pointer. The key 1319 * pointer set in such way is currently understood only by 1320 * verify_pkcs7_signature(). 1321 * 1322 * Set *id* to one of the values defined in include/linux/verification.h: 1323 * 0 for the primary keyring (immutable keyring of system keys); 1324 * VERIFY_USE_SECONDARY_KEYRING for both the primary and secondary keyring 1325 * (where keys can be added only if they are vouched for by existing keys 1326 * in those keyrings); VERIFY_USE_PLATFORM_KEYRING for the platform 1327 * keyring (primarily used by the integrity subsystem to verify a kexec'ed 1328 * kerned image and, possibly, the initramfs signature). 1329 * 1330 * Return: a bpf_key pointer with an invalid key pointer set from the 1331 * pre-determined ID on success, a NULL pointer otherwise 1332 */ 1333 __bpf_kfunc struct bpf_key *bpf_lookup_system_key(u64 id) 1334 { 1335 struct bpf_key *bkey; 1336 1337 if (system_keyring_id_check(id) < 0) 1338 return NULL; 1339 1340 bkey = kmalloc(sizeof(*bkey), GFP_ATOMIC); 1341 if (!bkey) 1342 return NULL; 1343 1344 bkey->key = (struct key *)(unsigned long)id; 1345 bkey->has_ref = false; 1346 1347 return bkey; 1348 } 1349 1350 /** 1351 * bpf_key_put - decrement key reference count if key is valid and free bpf_key 1352 * @bkey: bpf_key structure 1353 * 1354 * Decrement the reference count of the key inside *bkey*, if the pointer 1355 * is valid, and free *bkey*. 1356 */ 1357 __bpf_kfunc void bpf_key_put(struct bpf_key *bkey) 1358 { 1359 if (bkey->has_ref) 1360 key_put(bkey->key); 1361 1362 kfree(bkey); 1363 } 1364 1365 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION 1366 /** 1367 * bpf_verify_pkcs7_signature - verify a PKCS#7 signature 1368 * @data_ptr: data to verify 1369 * @sig_ptr: signature of the data 1370 * @trusted_keyring: keyring with keys trusted for signature verification 1371 * 1372 * Verify the PKCS#7 signature *sig_ptr* against the supplied *data_ptr* 1373 * with keys in a keyring referenced by *trusted_keyring*. 1374 * 1375 * Return: 0 on success, a negative value on error. 1376 */ 1377 __bpf_kfunc int bpf_verify_pkcs7_signature(struct bpf_dynptr_kern *data_ptr, 1378 struct bpf_dynptr_kern *sig_ptr, 1379 struct bpf_key *trusted_keyring) 1380 { 1381 int ret; 1382 1383 if (trusted_keyring->has_ref) { 1384 /* 1385 * Do the permission check deferred in bpf_lookup_user_key(). 1386 * See bpf_lookup_user_key() for more details. 1387 * 1388 * A call to key_task_permission() here would be redundant, as 1389 * it is already done by keyring_search() called by 1390 * find_asymmetric_key(). 1391 */ 1392 ret = key_validate(trusted_keyring->key); 1393 if (ret < 0) 1394 return ret; 1395 } 1396 1397 return verify_pkcs7_signature(data_ptr->data, 1398 __bpf_dynptr_size(data_ptr), 1399 sig_ptr->data, 1400 __bpf_dynptr_size(sig_ptr), 1401 trusted_keyring->key, 1402 VERIFYING_UNSPECIFIED_SIGNATURE, NULL, 1403 NULL); 1404 } 1405 #endif /* CONFIG_SYSTEM_DATA_VERIFICATION */ 1406 1407 __diag_pop(); 1408 1409 BTF_SET8_START(key_sig_kfunc_set) 1410 BTF_ID_FLAGS(func, bpf_lookup_user_key, KF_ACQUIRE | KF_RET_NULL | KF_SLEEPABLE) 1411 BTF_ID_FLAGS(func, bpf_lookup_system_key, KF_ACQUIRE | KF_RET_NULL) 1412 BTF_ID_FLAGS(func, bpf_key_put, KF_RELEASE) 1413 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION 1414 BTF_ID_FLAGS(func, bpf_verify_pkcs7_signature, KF_SLEEPABLE) 1415 #endif 1416 BTF_SET8_END(key_sig_kfunc_set) 1417 1418 static const struct btf_kfunc_id_set bpf_key_sig_kfunc_set = { 1419 .owner = THIS_MODULE, 1420 .set = &key_sig_kfunc_set, 1421 }; 1422 1423 static int __init bpf_key_sig_kfuncs_init(void) 1424 { 1425 return register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, 1426 &bpf_key_sig_kfunc_set); 1427 } 1428 1429 late_initcall(bpf_key_sig_kfuncs_init); 1430 #endif /* CONFIG_KEYS */ 1431 1432 static const struct bpf_func_proto * 1433 bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1434 { 1435 switch (func_id) { 1436 case BPF_FUNC_map_lookup_elem: 1437 return &bpf_map_lookup_elem_proto; 1438 case BPF_FUNC_map_update_elem: 1439 return &bpf_map_update_elem_proto; 1440 case BPF_FUNC_map_delete_elem: 1441 return &bpf_map_delete_elem_proto; 1442 case BPF_FUNC_map_push_elem: 1443 return &bpf_map_push_elem_proto; 1444 case BPF_FUNC_map_pop_elem: 1445 return &bpf_map_pop_elem_proto; 1446 case BPF_FUNC_map_peek_elem: 1447 return &bpf_map_peek_elem_proto; 1448 case BPF_FUNC_map_lookup_percpu_elem: 1449 return &bpf_map_lookup_percpu_elem_proto; 1450 case BPF_FUNC_ktime_get_ns: 1451 return &bpf_ktime_get_ns_proto; 1452 case BPF_FUNC_ktime_get_boot_ns: 1453 return &bpf_ktime_get_boot_ns_proto; 1454 case BPF_FUNC_tail_call: 1455 return &bpf_tail_call_proto; 1456 case BPF_FUNC_get_current_pid_tgid: 1457 return &bpf_get_current_pid_tgid_proto; 1458 case BPF_FUNC_get_current_task: 1459 return &bpf_get_current_task_proto; 1460 case BPF_FUNC_get_current_task_btf: 1461 return &bpf_get_current_task_btf_proto; 1462 case BPF_FUNC_task_pt_regs: 1463 return &bpf_task_pt_regs_proto; 1464 case BPF_FUNC_get_current_uid_gid: 1465 return &bpf_get_current_uid_gid_proto; 1466 case BPF_FUNC_get_current_comm: 1467 return &bpf_get_current_comm_proto; 1468 case BPF_FUNC_trace_printk: 1469 return bpf_get_trace_printk_proto(); 1470 case BPF_FUNC_get_smp_processor_id: 1471 return &bpf_get_smp_processor_id_proto; 1472 case BPF_FUNC_get_numa_node_id: 1473 return &bpf_get_numa_node_id_proto; 1474 case BPF_FUNC_perf_event_read: 1475 return &bpf_perf_event_read_proto; 1476 case BPF_FUNC_current_task_under_cgroup: 1477 return &bpf_current_task_under_cgroup_proto; 1478 case BPF_FUNC_get_prandom_u32: 1479 return &bpf_get_prandom_u32_proto; 1480 case BPF_FUNC_probe_write_user: 1481 return security_locked_down(LOCKDOWN_BPF_WRITE_USER) < 0 ? 1482 NULL : bpf_get_probe_write_proto(); 1483 case BPF_FUNC_probe_read_user: 1484 return &bpf_probe_read_user_proto; 1485 case BPF_FUNC_probe_read_kernel: 1486 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1487 NULL : &bpf_probe_read_kernel_proto; 1488 case BPF_FUNC_probe_read_user_str: 1489 return &bpf_probe_read_user_str_proto; 1490 case BPF_FUNC_probe_read_kernel_str: 1491 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1492 NULL : &bpf_probe_read_kernel_str_proto; 1493 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 1494 case BPF_FUNC_probe_read: 1495 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1496 NULL : &bpf_probe_read_compat_proto; 1497 case BPF_FUNC_probe_read_str: 1498 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1499 NULL : &bpf_probe_read_compat_str_proto; 1500 #endif 1501 #ifdef CONFIG_CGROUPS 1502 case BPF_FUNC_cgrp_storage_get: 1503 return &bpf_cgrp_storage_get_proto; 1504 case BPF_FUNC_cgrp_storage_delete: 1505 return &bpf_cgrp_storage_delete_proto; 1506 #endif 1507 case BPF_FUNC_send_signal: 1508 return &bpf_send_signal_proto; 1509 case BPF_FUNC_send_signal_thread: 1510 return &bpf_send_signal_thread_proto; 1511 case BPF_FUNC_perf_event_read_value: 1512 return &bpf_perf_event_read_value_proto; 1513 case BPF_FUNC_get_ns_current_pid_tgid: 1514 return &bpf_get_ns_current_pid_tgid_proto; 1515 case BPF_FUNC_ringbuf_output: 1516 return &bpf_ringbuf_output_proto; 1517 case BPF_FUNC_ringbuf_reserve: 1518 return &bpf_ringbuf_reserve_proto; 1519 case BPF_FUNC_ringbuf_submit: 1520 return &bpf_ringbuf_submit_proto; 1521 case BPF_FUNC_ringbuf_discard: 1522 return &bpf_ringbuf_discard_proto; 1523 case BPF_FUNC_ringbuf_query: 1524 return &bpf_ringbuf_query_proto; 1525 case BPF_FUNC_jiffies64: 1526 return &bpf_jiffies64_proto; 1527 case BPF_FUNC_get_task_stack: 1528 return &bpf_get_task_stack_proto; 1529 case BPF_FUNC_copy_from_user: 1530 return &bpf_copy_from_user_proto; 1531 case BPF_FUNC_copy_from_user_task: 1532 return &bpf_copy_from_user_task_proto; 1533 case BPF_FUNC_snprintf_btf: 1534 return &bpf_snprintf_btf_proto; 1535 case BPF_FUNC_per_cpu_ptr: 1536 return &bpf_per_cpu_ptr_proto; 1537 case BPF_FUNC_this_cpu_ptr: 1538 return &bpf_this_cpu_ptr_proto; 1539 case BPF_FUNC_task_storage_get: 1540 if (bpf_prog_check_recur(prog)) 1541 return &bpf_task_storage_get_recur_proto; 1542 return &bpf_task_storage_get_proto; 1543 case BPF_FUNC_task_storage_delete: 1544 if (bpf_prog_check_recur(prog)) 1545 return &bpf_task_storage_delete_recur_proto; 1546 return &bpf_task_storage_delete_proto; 1547 case BPF_FUNC_for_each_map_elem: 1548 return &bpf_for_each_map_elem_proto; 1549 case BPF_FUNC_snprintf: 1550 return &bpf_snprintf_proto; 1551 case BPF_FUNC_get_func_ip: 1552 return &bpf_get_func_ip_proto_tracing; 1553 case BPF_FUNC_get_branch_snapshot: 1554 return &bpf_get_branch_snapshot_proto; 1555 case BPF_FUNC_find_vma: 1556 return &bpf_find_vma_proto; 1557 case BPF_FUNC_trace_vprintk: 1558 return bpf_get_trace_vprintk_proto(); 1559 default: 1560 return bpf_base_func_proto(func_id); 1561 } 1562 } 1563 1564 static const struct bpf_func_proto * 1565 kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1566 { 1567 switch (func_id) { 1568 case BPF_FUNC_perf_event_output: 1569 return &bpf_perf_event_output_proto; 1570 case BPF_FUNC_get_stackid: 1571 return &bpf_get_stackid_proto; 1572 case BPF_FUNC_get_stack: 1573 return &bpf_get_stack_proto; 1574 #ifdef CONFIG_BPF_KPROBE_OVERRIDE 1575 case BPF_FUNC_override_return: 1576 return &bpf_override_return_proto; 1577 #endif 1578 case BPF_FUNC_get_func_ip: 1579 if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI) 1580 return &bpf_get_func_ip_proto_kprobe_multi; 1581 if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI) 1582 return &bpf_get_func_ip_proto_uprobe_multi; 1583 return &bpf_get_func_ip_proto_kprobe; 1584 case BPF_FUNC_get_attach_cookie: 1585 if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI) 1586 return &bpf_get_attach_cookie_proto_kmulti; 1587 if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI) 1588 return &bpf_get_attach_cookie_proto_umulti; 1589 return &bpf_get_attach_cookie_proto_trace; 1590 default: 1591 return bpf_tracing_func_proto(func_id, prog); 1592 } 1593 } 1594 1595 /* bpf+kprobe programs can access fields of 'struct pt_regs' */ 1596 static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type, 1597 const struct bpf_prog *prog, 1598 struct bpf_insn_access_aux *info) 1599 { 1600 if (off < 0 || off >= sizeof(struct pt_regs)) 1601 return false; 1602 if (type != BPF_READ) 1603 return false; 1604 if (off % size != 0) 1605 return false; 1606 /* 1607 * Assertion for 32 bit to make sure last 8 byte access 1608 * (BPF_DW) to the last 4 byte member is disallowed. 1609 */ 1610 if (off + size > sizeof(struct pt_regs)) 1611 return false; 1612 1613 return true; 1614 } 1615 1616 const struct bpf_verifier_ops kprobe_verifier_ops = { 1617 .get_func_proto = kprobe_prog_func_proto, 1618 .is_valid_access = kprobe_prog_is_valid_access, 1619 }; 1620 1621 const struct bpf_prog_ops kprobe_prog_ops = { 1622 }; 1623 1624 BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map, 1625 u64, flags, void *, data, u64, size) 1626 { 1627 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1628 1629 /* 1630 * r1 points to perf tracepoint buffer where first 8 bytes are hidden 1631 * from bpf program and contain a pointer to 'struct pt_regs'. Fetch it 1632 * from there and call the same bpf_perf_event_output() helper inline. 1633 */ 1634 return ____bpf_perf_event_output(regs, map, flags, data, size); 1635 } 1636 1637 static const struct bpf_func_proto bpf_perf_event_output_proto_tp = { 1638 .func = bpf_perf_event_output_tp, 1639 .gpl_only = true, 1640 .ret_type = RET_INTEGER, 1641 .arg1_type = ARG_PTR_TO_CTX, 1642 .arg2_type = ARG_CONST_MAP_PTR, 1643 .arg3_type = ARG_ANYTHING, 1644 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1645 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 1646 }; 1647 1648 BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map, 1649 u64, flags) 1650 { 1651 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1652 1653 /* 1654 * Same comment as in bpf_perf_event_output_tp(), only that this time 1655 * the other helper's function body cannot be inlined due to being 1656 * external, thus we need to call raw helper function. 1657 */ 1658 return bpf_get_stackid((unsigned long) regs, (unsigned long) map, 1659 flags, 0, 0); 1660 } 1661 1662 static const struct bpf_func_proto bpf_get_stackid_proto_tp = { 1663 .func = bpf_get_stackid_tp, 1664 .gpl_only = true, 1665 .ret_type = RET_INTEGER, 1666 .arg1_type = ARG_PTR_TO_CTX, 1667 .arg2_type = ARG_CONST_MAP_PTR, 1668 .arg3_type = ARG_ANYTHING, 1669 }; 1670 1671 BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size, 1672 u64, flags) 1673 { 1674 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1675 1676 return bpf_get_stack((unsigned long) regs, (unsigned long) buf, 1677 (unsigned long) size, flags, 0); 1678 } 1679 1680 static const struct bpf_func_proto bpf_get_stack_proto_tp = { 1681 .func = bpf_get_stack_tp, 1682 .gpl_only = true, 1683 .ret_type = RET_INTEGER, 1684 .arg1_type = ARG_PTR_TO_CTX, 1685 .arg2_type = ARG_PTR_TO_UNINIT_MEM, 1686 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1687 .arg4_type = ARG_ANYTHING, 1688 }; 1689 1690 static const struct bpf_func_proto * 1691 tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1692 { 1693 switch (func_id) { 1694 case BPF_FUNC_perf_event_output: 1695 return &bpf_perf_event_output_proto_tp; 1696 case BPF_FUNC_get_stackid: 1697 return &bpf_get_stackid_proto_tp; 1698 case BPF_FUNC_get_stack: 1699 return &bpf_get_stack_proto_tp; 1700 case BPF_FUNC_get_attach_cookie: 1701 return &bpf_get_attach_cookie_proto_trace; 1702 default: 1703 return bpf_tracing_func_proto(func_id, prog); 1704 } 1705 } 1706 1707 static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type, 1708 const struct bpf_prog *prog, 1709 struct bpf_insn_access_aux *info) 1710 { 1711 if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE) 1712 return false; 1713 if (type != BPF_READ) 1714 return false; 1715 if (off % size != 0) 1716 return false; 1717 1718 BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(__u64)); 1719 return true; 1720 } 1721 1722 const struct bpf_verifier_ops tracepoint_verifier_ops = { 1723 .get_func_proto = tp_prog_func_proto, 1724 .is_valid_access = tp_prog_is_valid_access, 1725 }; 1726 1727 const struct bpf_prog_ops tracepoint_prog_ops = { 1728 }; 1729 1730 BPF_CALL_3(bpf_perf_prog_read_value, struct bpf_perf_event_data_kern *, ctx, 1731 struct bpf_perf_event_value *, buf, u32, size) 1732 { 1733 int err = -EINVAL; 1734 1735 if (unlikely(size != sizeof(struct bpf_perf_event_value))) 1736 goto clear; 1737 err = perf_event_read_local(ctx->event, &buf->counter, &buf->enabled, 1738 &buf->running); 1739 if (unlikely(err)) 1740 goto clear; 1741 return 0; 1742 clear: 1743 memset(buf, 0, size); 1744 return err; 1745 } 1746 1747 static const struct bpf_func_proto bpf_perf_prog_read_value_proto = { 1748 .func = bpf_perf_prog_read_value, 1749 .gpl_only = true, 1750 .ret_type = RET_INTEGER, 1751 .arg1_type = ARG_PTR_TO_CTX, 1752 .arg2_type = ARG_PTR_TO_UNINIT_MEM, 1753 .arg3_type = ARG_CONST_SIZE, 1754 }; 1755 1756 BPF_CALL_4(bpf_read_branch_records, struct bpf_perf_event_data_kern *, ctx, 1757 void *, buf, u32, size, u64, flags) 1758 { 1759 static const u32 br_entry_size = sizeof(struct perf_branch_entry); 1760 struct perf_branch_stack *br_stack = ctx->data->br_stack; 1761 u32 to_copy; 1762 1763 if (unlikely(flags & ~BPF_F_GET_BRANCH_RECORDS_SIZE)) 1764 return -EINVAL; 1765 1766 if (unlikely(!(ctx->data->sample_flags & PERF_SAMPLE_BRANCH_STACK))) 1767 return -ENOENT; 1768 1769 if (unlikely(!br_stack)) 1770 return -ENOENT; 1771 1772 if (flags & BPF_F_GET_BRANCH_RECORDS_SIZE) 1773 return br_stack->nr * br_entry_size; 1774 1775 if (!buf || (size % br_entry_size != 0)) 1776 return -EINVAL; 1777 1778 to_copy = min_t(u32, br_stack->nr * br_entry_size, size); 1779 memcpy(buf, br_stack->entries, to_copy); 1780 1781 return to_copy; 1782 } 1783 1784 static const struct bpf_func_proto bpf_read_branch_records_proto = { 1785 .func = bpf_read_branch_records, 1786 .gpl_only = true, 1787 .ret_type = RET_INTEGER, 1788 .arg1_type = ARG_PTR_TO_CTX, 1789 .arg2_type = ARG_PTR_TO_MEM_OR_NULL, 1790 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1791 .arg4_type = ARG_ANYTHING, 1792 }; 1793 1794 static const struct bpf_func_proto * 1795 pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1796 { 1797 switch (func_id) { 1798 case BPF_FUNC_perf_event_output: 1799 return &bpf_perf_event_output_proto_tp; 1800 case BPF_FUNC_get_stackid: 1801 return &bpf_get_stackid_proto_pe; 1802 case BPF_FUNC_get_stack: 1803 return &bpf_get_stack_proto_pe; 1804 case BPF_FUNC_perf_prog_read_value: 1805 return &bpf_perf_prog_read_value_proto; 1806 case BPF_FUNC_read_branch_records: 1807 return &bpf_read_branch_records_proto; 1808 case BPF_FUNC_get_attach_cookie: 1809 return &bpf_get_attach_cookie_proto_pe; 1810 default: 1811 return bpf_tracing_func_proto(func_id, prog); 1812 } 1813 } 1814 1815 /* 1816 * bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp 1817 * to avoid potential recursive reuse issue when/if tracepoints are added 1818 * inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack. 1819 * 1820 * Since raw tracepoints run despite bpf_prog_active, support concurrent usage 1821 * in normal, irq, and nmi context. 1822 */ 1823 struct bpf_raw_tp_regs { 1824 struct pt_regs regs[3]; 1825 }; 1826 static DEFINE_PER_CPU(struct bpf_raw_tp_regs, bpf_raw_tp_regs); 1827 static DEFINE_PER_CPU(int, bpf_raw_tp_nest_level); 1828 static struct pt_regs *get_bpf_raw_tp_regs(void) 1829 { 1830 struct bpf_raw_tp_regs *tp_regs = this_cpu_ptr(&bpf_raw_tp_regs); 1831 int nest_level = this_cpu_inc_return(bpf_raw_tp_nest_level); 1832 1833 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(tp_regs->regs))) { 1834 this_cpu_dec(bpf_raw_tp_nest_level); 1835 return ERR_PTR(-EBUSY); 1836 } 1837 1838 return &tp_regs->regs[nest_level - 1]; 1839 } 1840 1841 static void put_bpf_raw_tp_regs(void) 1842 { 1843 this_cpu_dec(bpf_raw_tp_nest_level); 1844 } 1845 1846 BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args, 1847 struct bpf_map *, map, u64, flags, void *, data, u64, size) 1848 { 1849 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1850 int ret; 1851 1852 if (IS_ERR(regs)) 1853 return PTR_ERR(regs); 1854 1855 perf_fetch_caller_regs(regs); 1856 ret = ____bpf_perf_event_output(regs, map, flags, data, size); 1857 1858 put_bpf_raw_tp_regs(); 1859 return ret; 1860 } 1861 1862 static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = { 1863 .func = bpf_perf_event_output_raw_tp, 1864 .gpl_only = true, 1865 .ret_type = RET_INTEGER, 1866 .arg1_type = ARG_PTR_TO_CTX, 1867 .arg2_type = ARG_CONST_MAP_PTR, 1868 .arg3_type = ARG_ANYTHING, 1869 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1870 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 1871 }; 1872 1873 extern const struct bpf_func_proto bpf_skb_output_proto; 1874 extern const struct bpf_func_proto bpf_xdp_output_proto; 1875 extern const struct bpf_func_proto bpf_xdp_get_buff_len_trace_proto; 1876 1877 BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args, 1878 struct bpf_map *, map, u64, flags) 1879 { 1880 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1881 int ret; 1882 1883 if (IS_ERR(regs)) 1884 return PTR_ERR(regs); 1885 1886 perf_fetch_caller_regs(regs); 1887 /* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */ 1888 ret = bpf_get_stackid((unsigned long) regs, (unsigned long) map, 1889 flags, 0, 0); 1890 put_bpf_raw_tp_regs(); 1891 return ret; 1892 } 1893 1894 static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = { 1895 .func = bpf_get_stackid_raw_tp, 1896 .gpl_only = true, 1897 .ret_type = RET_INTEGER, 1898 .arg1_type = ARG_PTR_TO_CTX, 1899 .arg2_type = ARG_CONST_MAP_PTR, 1900 .arg3_type = ARG_ANYTHING, 1901 }; 1902 1903 BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args, 1904 void *, buf, u32, size, u64, flags) 1905 { 1906 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1907 int ret; 1908 1909 if (IS_ERR(regs)) 1910 return PTR_ERR(regs); 1911 1912 perf_fetch_caller_regs(regs); 1913 ret = bpf_get_stack((unsigned long) regs, (unsigned long) buf, 1914 (unsigned long) size, flags, 0); 1915 put_bpf_raw_tp_regs(); 1916 return ret; 1917 } 1918 1919 static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = { 1920 .func = bpf_get_stack_raw_tp, 1921 .gpl_only = true, 1922 .ret_type = RET_INTEGER, 1923 .arg1_type = ARG_PTR_TO_CTX, 1924 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1925 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1926 .arg4_type = ARG_ANYTHING, 1927 }; 1928 1929 static const struct bpf_func_proto * 1930 raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1931 { 1932 switch (func_id) { 1933 case BPF_FUNC_perf_event_output: 1934 return &bpf_perf_event_output_proto_raw_tp; 1935 case BPF_FUNC_get_stackid: 1936 return &bpf_get_stackid_proto_raw_tp; 1937 case BPF_FUNC_get_stack: 1938 return &bpf_get_stack_proto_raw_tp; 1939 default: 1940 return bpf_tracing_func_proto(func_id, prog); 1941 } 1942 } 1943 1944 const struct bpf_func_proto * 1945 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1946 { 1947 const struct bpf_func_proto *fn; 1948 1949 switch (func_id) { 1950 #ifdef CONFIG_NET 1951 case BPF_FUNC_skb_output: 1952 return &bpf_skb_output_proto; 1953 case BPF_FUNC_xdp_output: 1954 return &bpf_xdp_output_proto; 1955 case BPF_FUNC_skc_to_tcp6_sock: 1956 return &bpf_skc_to_tcp6_sock_proto; 1957 case BPF_FUNC_skc_to_tcp_sock: 1958 return &bpf_skc_to_tcp_sock_proto; 1959 case BPF_FUNC_skc_to_tcp_timewait_sock: 1960 return &bpf_skc_to_tcp_timewait_sock_proto; 1961 case BPF_FUNC_skc_to_tcp_request_sock: 1962 return &bpf_skc_to_tcp_request_sock_proto; 1963 case BPF_FUNC_skc_to_udp6_sock: 1964 return &bpf_skc_to_udp6_sock_proto; 1965 case BPF_FUNC_skc_to_unix_sock: 1966 return &bpf_skc_to_unix_sock_proto; 1967 case BPF_FUNC_skc_to_mptcp_sock: 1968 return &bpf_skc_to_mptcp_sock_proto; 1969 case BPF_FUNC_sk_storage_get: 1970 return &bpf_sk_storage_get_tracing_proto; 1971 case BPF_FUNC_sk_storage_delete: 1972 return &bpf_sk_storage_delete_tracing_proto; 1973 case BPF_FUNC_sock_from_file: 1974 return &bpf_sock_from_file_proto; 1975 case BPF_FUNC_get_socket_cookie: 1976 return &bpf_get_socket_ptr_cookie_proto; 1977 case BPF_FUNC_xdp_get_buff_len: 1978 return &bpf_xdp_get_buff_len_trace_proto; 1979 #endif 1980 case BPF_FUNC_seq_printf: 1981 return prog->expected_attach_type == BPF_TRACE_ITER ? 1982 &bpf_seq_printf_proto : 1983 NULL; 1984 case BPF_FUNC_seq_write: 1985 return prog->expected_attach_type == BPF_TRACE_ITER ? 1986 &bpf_seq_write_proto : 1987 NULL; 1988 case BPF_FUNC_seq_printf_btf: 1989 return prog->expected_attach_type == BPF_TRACE_ITER ? 1990 &bpf_seq_printf_btf_proto : 1991 NULL; 1992 case BPF_FUNC_d_path: 1993 return &bpf_d_path_proto; 1994 case BPF_FUNC_get_func_arg: 1995 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_proto : NULL; 1996 case BPF_FUNC_get_func_ret: 1997 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_ret_proto : NULL; 1998 case BPF_FUNC_get_func_arg_cnt: 1999 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_cnt_proto : NULL; 2000 case BPF_FUNC_get_attach_cookie: 2001 return bpf_prog_has_trampoline(prog) ? &bpf_get_attach_cookie_proto_tracing : NULL; 2002 default: 2003 fn = raw_tp_prog_func_proto(func_id, prog); 2004 if (!fn && prog->expected_attach_type == BPF_TRACE_ITER) 2005 fn = bpf_iter_get_func_proto(func_id, prog); 2006 return fn; 2007 } 2008 } 2009 2010 static bool raw_tp_prog_is_valid_access(int off, int size, 2011 enum bpf_access_type type, 2012 const struct bpf_prog *prog, 2013 struct bpf_insn_access_aux *info) 2014 { 2015 return bpf_tracing_ctx_access(off, size, type); 2016 } 2017 2018 static bool tracing_prog_is_valid_access(int off, int size, 2019 enum bpf_access_type type, 2020 const struct bpf_prog *prog, 2021 struct bpf_insn_access_aux *info) 2022 { 2023 return bpf_tracing_btf_ctx_access(off, size, type, prog, info); 2024 } 2025 2026 int __weak bpf_prog_test_run_tracing(struct bpf_prog *prog, 2027 const union bpf_attr *kattr, 2028 union bpf_attr __user *uattr) 2029 { 2030 return -ENOTSUPP; 2031 } 2032 2033 const struct bpf_verifier_ops raw_tracepoint_verifier_ops = { 2034 .get_func_proto = raw_tp_prog_func_proto, 2035 .is_valid_access = raw_tp_prog_is_valid_access, 2036 }; 2037 2038 const struct bpf_prog_ops raw_tracepoint_prog_ops = { 2039 #ifdef CONFIG_NET 2040 .test_run = bpf_prog_test_run_raw_tp, 2041 #endif 2042 }; 2043 2044 const struct bpf_verifier_ops tracing_verifier_ops = { 2045 .get_func_proto = tracing_prog_func_proto, 2046 .is_valid_access = tracing_prog_is_valid_access, 2047 }; 2048 2049 const struct bpf_prog_ops tracing_prog_ops = { 2050 .test_run = bpf_prog_test_run_tracing, 2051 }; 2052 2053 static bool raw_tp_writable_prog_is_valid_access(int off, int size, 2054 enum bpf_access_type type, 2055 const struct bpf_prog *prog, 2056 struct bpf_insn_access_aux *info) 2057 { 2058 if (off == 0) { 2059 if (size != sizeof(u64) || type != BPF_READ) 2060 return false; 2061 info->reg_type = PTR_TO_TP_BUFFER; 2062 } 2063 return raw_tp_prog_is_valid_access(off, size, type, prog, info); 2064 } 2065 2066 const struct bpf_verifier_ops raw_tracepoint_writable_verifier_ops = { 2067 .get_func_proto = raw_tp_prog_func_proto, 2068 .is_valid_access = raw_tp_writable_prog_is_valid_access, 2069 }; 2070 2071 const struct bpf_prog_ops raw_tracepoint_writable_prog_ops = { 2072 }; 2073 2074 static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type, 2075 const struct bpf_prog *prog, 2076 struct bpf_insn_access_aux *info) 2077 { 2078 const int size_u64 = sizeof(u64); 2079 2080 if (off < 0 || off >= sizeof(struct bpf_perf_event_data)) 2081 return false; 2082 if (type != BPF_READ) 2083 return false; 2084 if (off % size != 0) { 2085 if (sizeof(unsigned long) != 4) 2086 return false; 2087 if (size != 8) 2088 return false; 2089 if (off % size != 4) 2090 return false; 2091 } 2092 2093 switch (off) { 2094 case bpf_ctx_range(struct bpf_perf_event_data, sample_period): 2095 bpf_ctx_record_field_size(info, size_u64); 2096 if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) 2097 return false; 2098 break; 2099 case bpf_ctx_range(struct bpf_perf_event_data, addr): 2100 bpf_ctx_record_field_size(info, size_u64); 2101 if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) 2102 return false; 2103 break; 2104 default: 2105 if (size != sizeof(long)) 2106 return false; 2107 } 2108 2109 return true; 2110 } 2111 2112 static u32 pe_prog_convert_ctx_access(enum bpf_access_type type, 2113 const struct bpf_insn *si, 2114 struct bpf_insn *insn_buf, 2115 struct bpf_prog *prog, u32 *target_size) 2116 { 2117 struct bpf_insn *insn = insn_buf; 2118 2119 switch (si->off) { 2120 case offsetof(struct bpf_perf_event_data, sample_period): 2121 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 2122 data), si->dst_reg, si->src_reg, 2123 offsetof(struct bpf_perf_event_data_kern, data)); 2124 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, 2125 bpf_target_off(struct perf_sample_data, period, 8, 2126 target_size)); 2127 break; 2128 case offsetof(struct bpf_perf_event_data, addr): 2129 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 2130 data), si->dst_reg, si->src_reg, 2131 offsetof(struct bpf_perf_event_data_kern, data)); 2132 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, 2133 bpf_target_off(struct perf_sample_data, addr, 8, 2134 target_size)); 2135 break; 2136 default: 2137 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 2138 regs), si->dst_reg, si->src_reg, 2139 offsetof(struct bpf_perf_event_data_kern, regs)); 2140 *insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg, 2141 si->off); 2142 break; 2143 } 2144 2145 return insn - insn_buf; 2146 } 2147 2148 const struct bpf_verifier_ops perf_event_verifier_ops = { 2149 .get_func_proto = pe_prog_func_proto, 2150 .is_valid_access = pe_prog_is_valid_access, 2151 .convert_ctx_access = pe_prog_convert_ctx_access, 2152 }; 2153 2154 const struct bpf_prog_ops perf_event_prog_ops = { 2155 }; 2156 2157 static DEFINE_MUTEX(bpf_event_mutex); 2158 2159 #define BPF_TRACE_MAX_PROGS 64 2160 2161 int perf_event_attach_bpf_prog(struct perf_event *event, 2162 struct bpf_prog *prog, 2163 u64 bpf_cookie) 2164 { 2165 struct bpf_prog_array *old_array; 2166 struct bpf_prog_array *new_array; 2167 int ret = -EEXIST; 2168 2169 /* 2170 * Kprobe override only works if they are on the function entry, 2171 * and only if they are on the opt-in list. 2172 */ 2173 if (prog->kprobe_override && 2174 (!trace_kprobe_on_func_entry(event->tp_event) || 2175 !trace_kprobe_error_injectable(event->tp_event))) 2176 return -EINVAL; 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 if (old_array && 2185 bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) { 2186 ret = -E2BIG; 2187 goto unlock; 2188 } 2189 2190 ret = bpf_prog_array_copy(old_array, NULL, prog, bpf_cookie, &new_array); 2191 if (ret < 0) 2192 goto unlock; 2193 2194 /* set the new array to event->tp_event and set event->prog */ 2195 event->prog = prog; 2196 event->bpf_cookie = bpf_cookie; 2197 rcu_assign_pointer(event->tp_event->prog_array, new_array); 2198 bpf_prog_array_free_sleepable(old_array); 2199 2200 unlock: 2201 mutex_unlock(&bpf_event_mutex); 2202 return ret; 2203 } 2204 2205 void perf_event_detach_bpf_prog(struct perf_event *event) 2206 { 2207 struct bpf_prog_array *old_array; 2208 struct bpf_prog_array *new_array; 2209 int ret; 2210 2211 mutex_lock(&bpf_event_mutex); 2212 2213 if (!event->prog) 2214 goto unlock; 2215 2216 old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); 2217 ret = bpf_prog_array_copy(old_array, event->prog, NULL, 0, &new_array); 2218 if (ret == -ENOENT) 2219 goto unlock; 2220 if (ret < 0) { 2221 bpf_prog_array_delete_safe(old_array, event->prog); 2222 } else { 2223 rcu_assign_pointer(event->tp_event->prog_array, new_array); 2224 bpf_prog_array_free_sleepable(old_array); 2225 } 2226 2227 bpf_prog_put(event->prog); 2228 event->prog = NULL; 2229 2230 unlock: 2231 mutex_unlock(&bpf_event_mutex); 2232 } 2233 2234 int perf_event_query_prog_array(struct perf_event *event, void __user *info) 2235 { 2236 struct perf_event_query_bpf __user *uquery = info; 2237 struct perf_event_query_bpf query = {}; 2238 struct bpf_prog_array *progs; 2239 u32 *ids, prog_cnt, ids_len; 2240 int ret; 2241 2242 if (!perfmon_capable()) 2243 return -EPERM; 2244 if (event->attr.type != PERF_TYPE_TRACEPOINT) 2245 return -EINVAL; 2246 if (copy_from_user(&query, uquery, sizeof(query))) 2247 return -EFAULT; 2248 2249 ids_len = query.ids_len; 2250 if (ids_len > BPF_TRACE_MAX_PROGS) 2251 return -E2BIG; 2252 ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN); 2253 if (!ids) 2254 return -ENOMEM; 2255 /* 2256 * The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which 2257 * is required when user only wants to check for uquery->prog_cnt. 2258 * There is no need to check for it since the case is handled 2259 * gracefully in bpf_prog_array_copy_info. 2260 */ 2261 2262 mutex_lock(&bpf_event_mutex); 2263 progs = bpf_event_rcu_dereference(event->tp_event->prog_array); 2264 ret = bpf_prog_array_copy_info(progs, ids, ids_len, &prog_cnt); 2265 mutex_unlock(&bpf_event_mutex); 2266 2267 if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) || 2268 copy_to_user(uquery->ids, ids, ids_len * sizeof(u32))) 2269 ret = -EFAULT; 2270 2271 kfree(ids); 2272 return ret; 2273 } 2274 2275 extern struct bpf_raw_event_map __start__bpf_raw_tp[]; 2276 extern struct bpf_raw_event_map __stop__bpf_raw_tp[]; 2277 2278 struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name) 2279 { 2280 struct bpf_raw_event_map *btp = __start__bpf_raw_tp; 2281 2282 for (; btp < __stop__bpf_raw_tp; btp++) { 2283 if (!strcmp(btp->tp->name, name)) 2284 return btp; 2285 } 2286 2287 return bpf_get_raw_tracepoint_module(name); 2288 } 2289 2290 void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp) 2291 { 2292 struct module *mod; 2293 2294 preempt_disable(); 2295 mod = __module_address((unsigned long)btp); 2296 module_put(mod); 2297 preempt_enable(); 2298 } 2299 2300 static __always_inline 2301 void __bpf_trace_run(struct bpf_prog *prog, u64 *args) 2302 { 2303 cant_sleep(); 2304 if (unlikely(this_cpu_inc_return(*(prog->active)) != 1)) { 2305 bpf_prog_inc_misses_counter(prog); 2306 goto out; 2307 } 2308 rcu_read_lock(); 2309 (void) bpf_prog_run(prog, args); 2310 rcu_read_unlock(); 2311 out: 2312 this_cpu_dec(*(prog->active)); 2313 } 2314 2315 #define UNPACK(...) __VA_ARGS__ 2316 #define REPEAT_1(FN, DL, X, ...) FN(X) 2317 #define REPEAT_2(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__) 2318 #define REPEAT_3(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_2(FN, DL, __VA_ARGS__) 2319 #define REPEAT_4(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_3(FN, DL, __VA_ARGS__) 2320 #define REPEAT_5(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_4(FN, DL, __VA_ARGS__) 2321 #define REPEAT_6(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_5(FN, DL, __VA_ARGS__) 2322 #define REPEAT_7(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_6(FN, DL, __VA_ARGS__) 2323 #define REPEAT_8(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_7(FN, DL, __VA_ARGS__) 2324 #define REPEAT_9(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_8(FN, DL, __VA_ARGS__) 2325 #define REPEAT_10(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_9(FN, DL, __VA_ARGS__) 2326 #define REPEAT_11(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_10(FN, DL, __VA_ARGS__) 2327 #define REPEAT_12(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_11(FN, DL, __VA_ARGS__) 2328 #define REPEAT(X, FN, DL, ...) REPEAT_##X(FN, DL, __VA_ARGS__) 2329 2330 #define SARG(X) u64 arg##X 2331 #define COPY(X) args[X] = arg##X 2332 2333 #define __DL_COM (,) 2334 #define __DL_SEM (;) 2335 2336 #define __SEQ_0_11 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 2337 2338 #define BPF_TRACE_DEFN_x(x) \ 2339 void bpf_trace_run##x(struct bpf_prog *prog, \ 2340 REPEAT(x, SARG, __DL_COM, __SEQ_0_11)) \ 2341 { \ 2342 u64 args[x]; \ 2343 REPEAT(x, COPY, __DL_SEM, __SEQ_0_11); \ 2344 __bpf_trace_run(prog, args); \ 2345 } \ 2346 EXPORT_SYMBOL_GPL(bpf_trace_run##x) 2347 BPF_TRACE_DEFN_x(1); 2348 BPF_TRACE_DEFN_x(2); 2349 BPF_TRACE_DEFN_x(3); 2350 BPF_TRACE_DEFN_x(4); 2351 BPF_TRACE_DEFN_x(5); 2352 BPF_TRACE_DEFN_x(6); 2353 BPF_TRACE_DEFN_x(7); 2354 BPF_TRACE_DEFN_x(8); 2355 BPF_TRACE_DEFN_x(9); 2356 BPF_TRACE_DEFN_x(10); 2357 BPF_TRACE_DEFN_x(11); 2358 BPF_TRACE_DEFN_x(12); 2359 2360 static int __bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog) 2361 { 2362 struct tracepoint *tp = btp->tp; 2363 2364 /* 2365 * check that program doesn't access arguments beyond what's 2366 * available in this tracepoint 2367 */ 2368 if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64)) 2369 return -EINVAL; 2370 2371 if (prog->aux->max_tp_access > btp->writable_size) 2372 return -EINVAL; 2373 2374 return tracepoint_probe_register_may_exist(tp, (void *)btp->bpf_func, 2375 prog); 2376 } 2377 2378 int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog) 2379 { 2380 return __bpf_probe_register(btp, prog); 2381 } 2382 2383 int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_prog *prog) 2384 { 2385 return tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, prog); 2386 } 2387 2388 int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id, 2389 u32 *fd_type, const char **buf, 2390 u64 *probe_offset, u64 *probe_addr, 2391 unsigned long *missed) 2392 { 2393 bool is_tracepoint, is_syscall_tp; 2394 struct bpf_prog *prog; 2395 int flags, err = 0; 2396 2397 prog = event->prog; 2398 if (!prog) 2399 return -ENOENT; 2400 2401 /* not supporting BPF_PROG_TYPE_PERF_EVENT yet */ 2402 if (prog->type == BPF_PROG_TYPE_PERF_EVENT) 2403 return -EOPNOTSUPP; 2404 2405 *prog_id = prog->aux->id; 2406 flags = event->tp_event->flags; 2407 is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT; 2408 is_syscall_tp = is_syscall_trace_event(event->tp_event); 2409 2410 if (is_tracepoint || is_syscall_tp) { 2411 *buf = is_tracepoint ? event->tp_event->tp->name 2412 : event->tp_event->name; 2413 /* We allow NULL pointer for tracepoint */ 2414 if (fd_type) 2415 *fd_type = BPF_FD_TYPE_TRACEPOINT; 2416 if (probe_offset) 2417 *probe_offset = 0x0; 2418 if (probe_addr) 2419 *probe_addr = 0x0; 2420 } else { 2421 /* kprobe/uprobe */ 2422 err = -EOPNOTSUPP; 2423 #ifdef CONFIG_KPROBE_EVENTS 2424 if (flags & TRACE_EVENT_FL_KPROBE) 2425 err = bpf_get_kprobe_info(event, fd_type, buf, 2426 probe_offset, probe_addr, missed, 2427 event->attr.type == PERF_TYPE_TRACEPOINT); 2428 #endif 2429 #ifdef CONFIG_UPROBE_EVENTS 2430 if (flags & TRACE_EVENT_FL_UPROBE) 2431 err = bpf_get_uprobe_info(event, fd_type, buf, 2432 probe_offset, probe_addr, 2433 event->attr.type == PERF_TYPE_TRACEPOINT); 2434 #endif 2435 } 2436 2437 return err; 2438 } 2439 2440 static int __init send_signal_irq_work_init(void) 2441 { 2442 int cpu; 2443 struct send_signal_irq_work *work; 2444 2445 for_each_possible_cpu(cpu) { 2446 work = per_cpu_ptr(&send_signal_work, cpu); 2447 init_irq_work(&work->irq_work, do_bpf_send_signal); 2448 } 2449 return 0; 2450 } 2451 2452 subsys_initcall(send_signal_irq_work_init); 2453 2454 #ifdef CONFIG_MODULES 2455 static int bpf_event_notify(struct notifier_block *nb, unsigned long op, 2456 void *module) 2457 { 2458 struct bpf_trace_module *btm, *tmp; 2459 struct module *mod = module; 2460 int ret = 0; 2461 2462 if (mod->num_bpf_raw_events == 0 || 2463 (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING)) 2464 goto out; 2465 2466 mutex_lock(&bpf_module_mutex); 2467 2468 switch (op) { 2469 case MODULE_STATE_COMING: 2470 btm = kzalloc(sizeof(*btm), GFP_KERNEL); 2471 if (btm) { 2472 btm->module = module; 2473 list_add(&btm->list, &bpf_trace_modules); 2474 } else { 2475 ret = -ENOMEM; 2476 } 2477 break; 2478 case MODULE_STATE_GOING: 2479 list_for_each_entry_safe(btm, tmp, &bpf_trace_modules, list) { 2480 if (btm->module == module) { 2481 list_del(&btm->list); 2482 kfree(btm); 2483 break; 2484 } 2485 } 2486 break; 2487 } 2488 2489 mutex_unlock(&bpf_module_mutex); 2490 2491 out: 2492 return notifier_from_errno(ret); 2493 } 2494 2495 static struct notifier_block bpf_module_nb = { 2496 .notifier_call = bpf_event_notify, 2497 }; 2498 2499 static int __init bpf_event_init(void) 2500 { 2501 register_module_notifier(&bpf_module_nb); 2502 return 0; 2503 } 2504 2505 fs_initcall(bpf_event_init); 2506 #endif /* CONFIG_MODULES */ 2507 2508 #ifdef CONFIG_FPROBE 2509 struct bpf_kprobe_multi_link { 2510 struct bpf_link link; 2511 struct fprobe fp; 2512 unsigned long *addrs; 2513 u64 *cookies; 2514 u32 cnt; 2515 u32 mods_cnt; 2516 struct module **mods; 2517 u32 flags; 2518 }; 2519 2520 struct bpf_kprobe_multi_run_ctx { 2521 struct bpf_run_ctx run_ctx; 2522 struct bpf_kprobe_multi_link *link; 2523 unsigned long entry_ip; 2524 }; 2525 2526 struct user_syms { 2527 const char **syms; 2528 char *buf; 2529 }; 2530 2531 static int copy_user_syms(struct user_syms *us, unsigned long __user *usyms, u32 cnt) 2532 { 2533 unsigned long __user usymbol; 2534 const char **syms = NULL; 2535 char *buf = NULL, *p; 2536 int err = -ENOMEM; 2537 unsigned int i; 2538 2539 syms = kvmalloc_array(cnt, sizeof(*syms), GFP_KERNEL); 2540 if (!syms) 2541 goto error; 2542 2543 buf = kvmalloc_array(cnt, KSYM_NAME_LEN, GFP_KERNEL); 2544 if (!buf) 2545 goto error; 2546 2547 for (p = buf, i = 0; i < cnt; i++) { 2548 if (__get_user(usymbol, usyms + i)) { 2549 err = -EFAULT; 2550 goto error; 2551 } 2552 err = strncpy_from_user(p, (const char __user *) usymbol, KSYM_NAME_LEN); 2553 if (err == KSYM_NAME_LEN) 2554 err = -E2BIG; 2555 if (err < 0) 2556 goto error; 2557 syms[i] = p; 2558 p += err + 1; 2559 } 2560 2561 us->syms = syms; 2562 us->buf = buf; 2563 return 0; 2564 2565 error: 2566 if (err) { 2567 kvfree(syms); 2568 kvfree(buf); 2569 } 2570 return err; 2571 } 2572 2573 static void kprobe_multi_put_modules(struct module **mods, u32 cnt) 2574 { 2575 u32 i; 2576 2577 for (i = 0; i < cnt; i++) 2578 module_put(mods[i]); 2579 } 2580 2581 static void free_user_syms(struct user_syms *us) 2582 { 2583 kvfree(us->syms); 2584 kvfree(us->buf); 2585 } 2586 2587 static void bpf_kprobe_multi_link_release(struct bpf_link *link) 2588 { 2589 struct bpf_kprobe_multi_link *kmulti_link; 2590 2591 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); 2592 unregister_fprobe(&kmulti_link->fp); 2593 kprobe_multi_put_modules(kmulti_link->mods, kmulti_link->mods_cnt); 2594 } 2595 2596 static void bpf_kprobe_multi_link_dealloc(struct bpf_link *link) 2597 { 2598 struct bpf_kprobe_multi_link *kmulti_link; 2599 2600 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); 2601 kvfree(kmulti_link->addrs); 2602 kvfree(kmulti_link->cookies); 2603 kfree(kmulti_link->mods); 2604 kfree(kmulti_link); 2605 } 2606 2607 static int bpf_kprobe_multi_link_fill_link_info(const struct bpf_link *link, 2608 struct bpf_link_info *info) 2609 { 2610 u64 __user *uaddrs = u64_to_user_ptr(info->kprobe_multi.addrs); 2611 struct bpf_kprobe_multi_link *kmulti_link; 2612 u32 ucount = info->kprobe_multi.count; 2613 int err = 0, i; 2614 2615 if (!uaddrs ^ !ucount) 2616 return -EINVAL; 2617 2618 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); 2619 info->kprobe_multi.count = kmulti_link->cnt; 2620 info->kprobe_multi.flags = kmulti_link->flags; 2621 info->kprobe_multi.missed = kmulti_link->fp.nmissed; 2622 2623 if (!uaddrs) 2624 return 0; 2625 if (ucount < kmulti_link->cnt) 2626 err = -ENOSPC; 2627 else 2628 ucount = kmulti_link->cnt; 2629 2630 if (kallsyms_show_value(current_cred())) { 2631 if (copy_to_user(uaddrs, kmulti_link->addrs, ucount * sizeof(u64))) 2632 return -EFAULT; 2633 } else { 2634 for (i = 0; i < ucount; i++) { 2635 if (put_user(0, uaddrs + i)) 2636 return -EFAULT; 2637 } 2638 } 2639 return err; 2640 } 2641 2642 static const struct bpf_link_ops bpf_kprobe_multi_link_lops = { 2643 .release = bpf_kprobe_multi_link_release, 2644 .dealloc = bpf_kprobe_multi_link_dealloc, 2645 .fill_link_info = bpf_kprobe_multi_link_fill_link_info, 2646 }; 2647 2648 static void bpf_kprobe_multi_cookie_swap(void *a, void *b, int size, const void *priv) 2649 { 2650 const struct bpf_kprobe_multi_link *link = priv; 2651 unsigned long *addr_a = a, *addr_b = b; 2652 u64 *cookie_a, *cookie_b; 2653 2654 cookie_a = link->cookies + (addr_a - link->addrs); 2655 cookie_b = link->cookies + (addr_b - link->addrs); 2656 2657 /* swap addr_a/addr_b and cookie_a/cookie_b values */ 2658 swap(*addr_a, *addr_b); 2659 swap(*cookie_a, *cookie_b); 2660 } 2661 2662 static int bpf_kprobe_multi_addrs_cmp(const void *a, const void *b) 2663 { 2664 const unsigned long *addr_a = a, *addr_b = b; 2665 2666 if (*addr_a == *addr_b) 2667 return 0; 2668 return *addr_a < *addr_b ? -1 : 1; 2669 } 2670 2671 static int bpf_kprobe_multi_cookie_cmp(const void *a, const void *b, const void *priv) 2672 { 2673 return bpf_kprobe_multi_addrs_cmp(a, b); 2674 } 2675 2676 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx) 2677 { 2678 struct bpf_kprobe_multi_run_ctx *run_ctx; 2679 struct bpf_kprobe_multi_link *link; 2680 u64 *cookie, entry_ip; 2681 unsigned long *addr; 2682 2683 if (WARN_ON_ONCE(!ctx)) 2684 return 0; 2685 run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, run_ctx); 2686 link = run_ctx->link; 2687 if (!link->cookies) 2688 return 0; 2689 entry_ip = run_ctx->entry_ip; 2690 addr = bsearch(&entry_ip, link->addrs, link->cnt, sizeof(entry_ip), 2691 bpf_kprobe_multi_addrs_cmp); 2692 if (!addr) 2693 return 0; 2694 cookie = link->cookies + (addr - link->addrs); 2695 return *cookie; 2696 } 2697 2698 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 2699 { 2700 struct bpf_kprobe_multi_run_ctx *run_ctx; 2701 2702 run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, run_ctx); 2703 return run_ctx->entry_ip; 2704 } 2705 2706 static int 2707 kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link, 2708 unsigned long entry_ip, struct pt_regs *regs) 2709 { 2710 struct bpf_kprobe_multi_run_ctx run_ctx = { 2711 .link = link, 2712 .entry_ip = entry_ip, 2713 }; 2714 struct bpf_run_ctx *old_run_ctx; 2715 int err; 2716 2717 if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) { 2718 bpf_prog_inc_misses_counter(link->link.prog); 2719 err = 0; 2720 goto out; 2721 } 2722 2723 migrate_disable(); 2724 rcu_read_lock(); 2725 old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx); 2726 err = bpf_prog_run(link->link.prog, regs); 2727 bpf_reset_run_ctx(old_run_ctx); 2728 rcu_read_unlock(); 2729 migrate_enable(); 2730 2731 out: 2732 __this_cpu_dec(bpf_prog_active); 2733 return err; 2734 } 2735 2736 static int 2737 kprobe_multi_link_handler(struct fprobe *fp, unsigned long fentry_ip, 2738 unsigned long ret_ip, struct pt_regs *regs, 2739 void *data) 2740 { 2741 struct bpf_kprobe_multi_link *link; 2742 2743 link = container_of(fp, struct bpf_kprobe_multi_link, fp); 2744 kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), regs); 2745 return 0; 2746 } 2747 2748 static void 2749 kprobe_multi_link_exit_handler(struct fprobe *fp, unsigned long fentry_ip, 2750 unsigned long ret_ip, struct pt_regs *regs, 2751 void *data) 2752 { 2753 struct bpf_kprobe_multi_link *link; 2754 2755 link = container_of(fp, struct bpf_kprobe_multi_link, fp); 2756 kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), regs); 2757 } 2758 2759 static int symbols_cmp_r(const void *a, const void *b, const void *priv) 2760 { 2761 const char **str_a = (const char **) a; 2762 const char **str_b = (const char **) b; 2763 2764 return strcmp(*str_a, *str_b); 2765 } 2766 2767 struct multi_symbols_sort { 2768 const char **funcs; 2769 u64 *cookies; 2770 }; 2771 2772 static void symbols_swap_r(void *a, void *b, int size, const void *priv) 2773 { 2774 const struct multi_symbols_sort *data = priv; 2775 const char **name_a = a, **name_b = b; 2776 2777 swap(*name_a, *name_b); 2778 2779 /* If defined, swap also related cookies. */ 2780 if (data->cookies) { 2781 u64 *cookie_a, *cookie_b; 2782 2783 cookie_a = data->cookies + (name_a - data->funcs); 2784 cookie_b = data->cookies + (name_b - data->funcs); 2785 swap(*cookie_a, *cookie_b); 2786 } 2787 } 2788 2789 struct modules_array { 2790 struct module **mods; 2791 int mods_cnt; 2792 int mods_cap; 2793 }; 2794 2795 static int add_module(struct modules_array *arr, struct module *mod) 2796 { 2797 struct module **mods; 2798 2799 if (arr->mods_cnt == arr->mods_cap) { 2800 arr->mods_cap = max(16, arr->mods_cap * 3 / 2); 2801 mods = krealloc_array(arr->mods, arr->mods_cap, sizeof(*mods), GFP_KERNEL); 2802 if (!mods) 2803 return -ENOMEM; 2804 arr->mods = mods; 2805 } 2806 2807 arr->mods[arr->mods_cnt] = mod; 2808 arr->mods_cnt++; 2809 return 0; 2810 } 2811 2812 static bool has_module(struct modules_array *arr, struct module *mod) 2813 { 2814 int i; 2815 2816 for (i = arr->mods_cnt - 1; i >= 0; i--) { 2817 if (arr->mods[i] == mod) 2818 return true; 2819 } 2820 return false; 2821 } 2822 2823 static int get_modules_for_addrs(struct module ***mods, unsigned long *addrs, u32 addrs_cnt) 2824 { 2825 struct modules_array arr = {}; 2826 u32 i, err = 0; 2827 2828 for (i = 0; i < addrs_cnt; i++) { 2829 struct module *mod; 2830 2831 preempt_disable(); 2832 mod = __module_address(addrs[i]); 2833 /* Either no module or we it's already stored */ 2834 if (!mod || has_module(&arr, mod)) { 2835 preempt_enable(); 2836 continue; 2837 } 2838 if (!try_module_get(mod)) 2839 err = -EINVAL; 2840 preempt_enable(); 2841 if (err) 2842 break; 2843 err = add_module(&arr, mod); 2844 if (err) { 2845 module_put(mod); 2846 break; 2847 } 2848 } 2849 2850 /* We return either err < 0 in case of error, ... */ 2851 if (err) { 2852 kprobe_multi_put_modules(arr.mods, arr.mods_cnt); 2853 kfree(arr.mods); 2854 return err; 2855 } 2856 2857 /* or number of modules found if everything is ok. */ 2858 *mods = arr.mods; 2859 return arr.mods_cnt; 2860 } 2861 2862 static int addrs_check_error_injection_list(unsigned long *addrs, u32 cnt) 2863 { 2864 u32 i; 2865 2866 for (i = 0; i < cnt; i++) { 2867 if (!within_error_injection_list(addrs[i])) 2868 return -EINVAL; 2869 } 2870 return 0; 2871 } 2872 2873 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 2874 { 2875 struct bpf_kprobe_multi_link *link = NULL; 2876 struct bpf_link_primer link_primer; 2877 void __user *ucookies; 2878 unsigned long *addrs; 2879 u32 flags, cnt, size; 2880 void __user *uaddrs; 2881 u64 *cookies = NULL; 2882 void __user *usyms; 2883 int err; 2884 2885 /* no support for 32bit archs yet */ 2886 if (sizeof(u64) != sizeof(void *)) 2887 return -EOPNOTSUPP; 2888 2889 if (prog->expected_attach_type != BPF_TRACE_KPROBE_MULTI) 2890 return -EINVAL; 2891 2892 flags = attr->link_create.kprobe_multi.flags; 2893 if (flags & ~BPF_F_KPROBE_MULTI_RETURN) 2894 return -EINVAL; 2895 2896 uaddrs = u64_to_user_ptr(attr->link_create.kprobe_multi.addrs); 2897 usyms = u64_to_user_ptr(attr->link_create.kprobe_multi.syms); 2898 if (!!uaddrs == !!usyms) 2899 return -EINVAL; 2900 2901 cnt = attr->link_create.kprobe_multi.cnt; 2902 if (!cnt) 2903 return -EINVAL; 2904 2905 size = cnt * sizeof(*addrs); 2906 addrs = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL); 2907 if (!addrs) 2908 return -ENOMEM; 2909 2910 ucookies = u64_to_user_ptr(attr->link_create.kprobe_multi.cookies); 2911 if (ucookies) { 2912 cookies = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL); 2913 if (!cookies) { 2914 err = -ENOMEM; 2915 goto error; 2916 } 2917 if (copy_from_user(cookies, ucookies, size)) { 2918 err = -EFAULT; 2919 goto error; 2920 } 2921 } 2922 2923 if (uaddrs) { 2924 if (copy_from_user(addrs, uaddrs, size)) { 2925 err = -EFAULT; 2926 goto error; 2927 } 2928 } else { 2929 struct multi_symbols_sort data = { 2930 .cookies = cookies, 2931 }; 2932 struct user_syms us; 2933 2934 err = copy_user_syms(&us, usyms, cnt); 2935 if (err) 2936 goto error; 2937 2938 if (cookies) 2939 data.funcs = us.syms; 2940 2941 sort_r(us.syms, cnt, sizeof(*us.syms), symbols_cmp_r, 2942 symbols_swap_r, &data); 2943 2944 err = ftrace_lookup_symbols(us.syms, cnt, addrs); 2945 free_user_syms(&us); 2946 if (err) 2947 goto error; 2948 } 2949 2950 if (prog->kprobe_override && addrs_check_error_injection_list(addrs, cnt)) { 2951 err = -EINVAL; 2952 goto error; 2953 } 2954 2955 link = kzalloc(sizeof(*link), GFP_KERNEL); 2956 if (!link) { 2957 err = -ENOMEM; 2958 goto error; 2959 } 2960 2961 bpf_link_init(&link->link, BPF_LINK_TYPE_KPROBE_MULTI, 2962 &bpf_kprobe_multi_link_lops, prog); 2963 2964 err = bpf_link_prime(&link->link, &link_primer); 2965 if (err) 2966 goto error; 2967 2968 if (flags & BPF_F_KPROBE_MULTI_RETURN) 2969 link->fp.exit_handler = kprobe_multi_link_exit_handler; 2970 else 2971 link->fp.entry_handler = kprobe_multi_link_handler; 2972 2973 link->addrs = addrs; 2974 link->cookies = cookies; 2975 link->cnt = cnt; 2976 link->flags = flags; 2977 2978 if (cookies) { 2979 /* 2980 * Sorting addresses will trigger sorting cookies as well 2981 * (check bpf_kprobe_multi_cookie_swap). This way we can 2982 * find cookie based on the address in bpf_get_attach_cookie 2983 * helper. 2984 */ 2985 sort_r(addrs, cnt, sizeof(*addrs), 2986 bpf_kprobe_multi_cookie_cmp, 2987 bpf_kprobe_multi_cookie_swap, 2988 link); 2989 } 2990 2991 err = get_modules_for_addrs(&link->mods, addrs, cnt); 2992 if (err < 0) { 2993 bpf_link_cleanup(&link_primer); 2994 return err; 2995 } 2996 link->mods_cnt = err; 2997 2998 err = register_fprobe_ips(&link->fp, addrs, cnt); 2999 if (err) { 3000 kprobe_multi_put_modules(link->mods, link->mods_cnt); 3001 bpf_link_cleanup(&link_primer); 3002 return err; 3003 } 3004 3005 return bpf_link_settle(&link_primer); 3006 3007 error: 3008 kfree(link); 3009 kvfree(addrs); 3010 kvfree(cookies); 3011 return err; 3012 } 3013 #else /* !CONFIG_FPROBE */ 3014 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 3015 { 3016 return -EOPNOTSUPP; 3017 } 3018 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx) 3019 { 3020 return 0; 3021 } 3022 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 3023 { 3024 return 0; 3025 } 3026 #endif 3027 3028 #ifdef CONFIG_UPROBES 3029 struct bpf_uprobe_multi_link; 3030 3031 struct bpf_uprobe { 3032 struct bpf_uprobe_multi_link *link; 3033 loff_t offset; 3034 u64 cookie; 3035 struct uprobe_consumer consumer; 3036 }; 3037 3038 struct bpf_uprobe_multi_link { 3039 struct path path; 3040 struct bpf_link link; 3041 u32 cnt; 3042 struct bpf_uprobe *uprobes; 3043 struct task_struct *task; 3044 }; 3045 3046 struct bpf_uprobe_multi_run_ctx { 3047 struct bpf_run_ctx run_ctx; 3048 unsigned long entry_ip; 3049 struct bpf_uprobe *uprobe; 3050 }; 3051 3052 static void bpf_uprobe_unregister(struct path *path, struct bpf_uprobe *uprobes, 3053 u32 cnt) 3054 { 3055 u32 i; 3056 3057 for (i = 0; i < cnt; i++) { 3058 uprobe_unregister(d_real_inode(path->dentry), uprobes[i].offset, 3059 &uprobes[i].consumer); 3060 } 3061 } 3062 3063 static void bpf_uprobe_multi_link_release(struct bpf_link *link) 3064 { 3065 struct bpf_uprobe_multi_link *umulti_link; 3066 3067 umulti_link = container_of(link, struct bpf_uprobe_multi_link, link); 3068 bpf_uprobe_unregister(&umulti_link->path, umulti_link->uprobes, umulti_link->cnt); 3069 } 3070 3071 static void bpf_uprobe_multi_link_dealloc(struct bpf_link *link) 3072 { 3073 struct bpf_uprobe_multi_link *umulti_link; 3074 3075 umulti_link = container_of(link, struct bpf_uprobe_multi_link, link); 3076 if (umulti_link->task) 3077 put_task_struct(umulti_link->task); 3078 path_put(&umulti_link->path); 3079 kvfree(umulti_link->uprobes); 3080 kfree(umulti_link); 3081 } 3082 3083 static const struct bpf_link_ops bpf_uprobe_multi_link_lops = { 3084 .release = bpf_uprobe_multi_link_release, 3085 .dealloc = bpf_uprobe_multi_link_dealloc, 3086 }; 3087 3088 static int uprobe_prog_run(struct bpf_uprobe *uprobe, 3089 unsigned long entry_ip, 3090 struct pt_regs *regs) 3091 { 3092 struct bpf_uprobe_multi_link *link = uprobe->link; 3093 struct bpf_uprobe_multi_run_ctx run_ctx = { 3094 .entry_ip = entry_ip, 3095 .uprobe = uprobe, 3096 }; 3097 struct bpf_prog *prog = link->link.prog; 3098 bool sleepable = prog->aux->sleepable; 3099 struct bpf_run_ctx *old_run_ctx; 3100 int err = 0; 3101 3102 if (link->task && current != link->task) 3103 return 0; 3104 3105 if (sleepable) 3106 rcu_read_lock_trace(); 3107 else 3108 rcu_read_lock(); 3109 3110 migrate_disable(); 3111 3112 old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx); 3113 err = bpf_prog_run(link->link.prog, regs); 3114 bpf_reset_run_ctx(old_run_ctx); 3115 3116 migrate_enable(); 3117 3118 if (sleepable) 3119 rcu_read_unlock_trace(); 3120 else 3121 rcu_read_unlock(); 3122 return err; 3123 } 3124 3125 static bool 3126 uprobe_multi_link_filter(struct uprobe_consumer *con, enum uprobe_filter_ctx ctx, 3127 struct mm_struct *mm) 3128 { 3129 struct bpf_uprobe *uprobe; 3130 3131 uprobe = container_of(con, struct bpf_uprobe, consumer); 3132 return uprobe->link->task->mm == mm; 3133 } 3134 3135 static int 3136 uprobe_multi_link_handler(struct uprobe_consumer *con, struct pt_regs *regs) 3137 { 3138 struct bpf_uprobe *uprobe; 3139 3140 uprobe = container_of(con, struct bpf_uprobe, consumer); 3141 return uprobe_prog_run(uprobe, instruction_pointer(regs), regs); 3142 } 3143 3144 static int 3145 uprobe_multi_link_ret_handler(struct uprobe_consumer *con, unsigned long func, struct pt_regs *regs) 3146 { 3147 struct bpf_uprobe *uprobe; 3148 3149 uprobe = container_of(con, struct bpf_uprobe, consumer); 3150 return uprobe_prog_run(uprobe, func, regs); 3151 } 3152 3153 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 3154 { 3155 struct bpf_uprobe_multi_run_ctx *run_ctx; 3156 3157 run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx, run_ctx); 3158 return run_ctx->entry_ip; 3159 } 3160 3161 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx) 3162 { 3163 struct bpf_uprobe_multi_run_ctx *run_ctx; 3164 3165 run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx, run_ctx); 3166 return run_ctx->uprobe->cookie; 3167 } 3168 3169 int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 3170 { 3171 struct bpf_uprobe_multi_link *link = NULL; 3172 unsigned long __user *uref_ctr_offsets; 3173 unsigned long *ref_ctr_offsets = NULL; 3174 struct bpf_link_primer link_primer; 3175 struct bpf_uprobe *uprobes = NULL; 3176 struct task_struct *task = NULL; 3177 unsigned long __user *uoffsets; 3178 u64 __user *ucookies; 3179 void __user *upath; 3180 u32 flags, cnt, i; 3181 struct path path; 3182 char *name; 3183 pid_t pid; 3184 int err; 3185 3186 /* no support for 32bit archs yet */ 3187 if (sizeof(u64) != sizeof(void *)) 3188 return -EOPNOTSUPP; 3189 3190 if (prog->expected_attach_type != BPF_TRACE_UPROBE_MULTI) 3191 return -EINVAL; 3192 3193 flags = attr->link_create.uprobe_multi.flags; 3194 if (flags & ~BPF_F_UPROBE_MULTI_RETURN) 3195 return -EINVAL; 3196 3197 /* 3198 * path, offsets and cnt are mandatory, 3199 * ref_ctr_offsets and cookies are optional 3200 */ 3201 upath = u64_to_user_ptr(attr->link_create.uprobe_multi.path); 3202 uoffsets = u64_to_user_ptr(attr->link_create.uprobe_multi.offsets); 3203 cnt = attr->link_create.uprobe_multi.cnt; 3204 3205 if (!upath || !uoffsets || !cnt) 3206 return -EINVAL; 3207 3208 uref_ctr_offsets = u64_to_user_ptr(attr->link_create.uprobe_multi.ref_ctr_offsets); 3209 ucookies = u64_to_user_ptr(attr->link_create.uprobe_multi.cookies); 3210 3211 name = strndup_user(upath, PATH_MAX); 3212 if (IS_ERR(name)) { 3213 err = PTR_ERR(name); 3214 return err; 3215 } 3216 3217 err = kern_path(name, LOOKUP_FOLLOW, &path); 3218 kfree(name); 3219 if (err) 3220 return err; 3221 3222 if (!d_is_reg(path.dentry)) { 3223 err = -EBADF; 3224 goto error_path_put; 3225 } 3226 3227 pid = attr->link_create.uprobe_multi.pid; 3228 if (pid) { 3229 rcu_read_lock(); 3230 task = get_pid_task(find_vpid(pid), PIDTYPE_PID); 3231 rcu_read_unlock(); 3232 if (!task) { 3233 err = -ESRCH; 3234 goto error_path_put; 3235 } 3236 } 3237 3238 err = -ENOMEM; 3239 3240 link = kzalloc(sizeof(*link), GFP_KERNEL); 3241 uprobes = kvcalloc(cnt, sizeof(*uprobes), GFP_KERNEL); 3242 3243 if (!uprobes || !link) 3244 goto error_free; 3245 3246 if (uref_ctr_offsets) { 3247 ref_ctr_offsets = kvcalloc(cnt, sizeof(*ref_ctr_offsets), GFP_KERNEL); 3248 if (!ref_ctr_offsets) 3249 goto error_free; 3250 } 3251 3252 for (i = 0; i < cnt; i++) { 3253 if (ucookies && __get_user(uprobes[i].cookie, ucookies + i)) { 3254 err = -EFAULT; 3255 goto error_free; 3256 } 3257 if (uref_ctr_offsets && __get_user(ref_ctr_offsets[i], uref_ctr_offsets + i)) { 3258 err = -EFAULT; 3259 goto error_free; 3260 } 3261 if (__get_user(uprobes[i].offset, uoffsets + i)) { 3262 err = -EFAULT; 3263 goto error_free; 3264 } 3265 3266 uprobes[i].link = link; 3267 3268 if (flags & BPF_F_UPROBE_MULTI_RETURN) 3269 uprobes[i].consumer.ret_handler = uprobe_multi_link_ret_handler; 3270 else 3271 uprobes[i].consumer.handler = uprobe_multi_link_handler; 3272 3273 if (pid) 3274 uprobes[i].consumer.filter = uprobe_multi_link_filter; 3275 } 3276 3277 link->cnt = cnt; 3278 link->uprobes = uprobes; 3279 link->path = path; 3280 link->task = task; 3281 3282 bpf_link_init(&link->link, BPF_LINK_TYPE_UPROBE_MULTI, 3283 &bpf_uprobe_multi_link_lops, prog); 3284 3285 for (i = 0; i < cnt; i++) { 3286 err = uprobe_register_refctr(d_real_inode(link->path.dentry), 3287 uprobes[i].offset, 3288 ref_ctr_offsets ? ref_ctr_offsets[i] : 0, 3289 &uprobes[i].consumer); 3290 if (err) { 3291 bpf_uprobe_unregister(&path, uprobes, i); 3292 goto error_free; 3293 } 3294 } 3295 3296 err = bpf_link_prime(&link->link, &link_primer); 3297 if (err) 3298 goto error_free; 3299 3300 kvfree(ref_ctr_offsets); 3301 return bpf_link_settle(&link_primer); 3302 3303 error_free: 3304 kvfree(ref_ctr_offsets); 3305 kvfree(uprobes); 3306 kfree(link); 3307 if (task) 3308 put_task_struct(task); 3309 error_path_put: 3310 path_put(&path); 3311 return err; 3312 } 3313 #else /* !CONFIG_UPROBES */ 3314 int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 3315 { 3316 return -EOPNOTSUPP; 3317 } 3318 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx) 3319 { 3320 return 0; 3321 } 3322 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 3323 { 3324 return 0; 3325 } 3326 #endif /* CONFIG_UPROBES */ 3327