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 __bpf_kfunc_start_defs(); 1256 1257 /** 1258 * bpf_lookup_user_key - lookup a key by its serial 1259 * @serial: key handle serial number 1260 * @flags: lookup-specific flags 1261 * 1262 * Search a key with a given *serial* and the provided *flags*. 1263 * If found, increment the reference count of the key by one, and 1264 * return it in the bpf_key structure. 1265 * 1266 * The bpf_key structure must be passed to bpf_key_put() when done 1267 * with it, so that the key reference count is decremented and the 1268 * bpf_key structure is freed. 1269 * 1270 * Permission checks are deferred to the time the key is used by 1271 * one of the available key-specific kfuncs. 1272 * 1273 * Set *flags* with KEY_LOOKUP_CREATE, to attempt creating a requested 1274 * special keyring (e.g. session keyring), if it doesn't yet exist. 1275 * Set *flags* with KEY_LOOKUP_PARTIAL, to lookup a key without waiting 1276 * for the key construction, and to retrieve uninstantiated keys (keys 1277 * without data attached to them). 1278 * 1279 * Return: a bpf_key pointer with a valid key pointer if the key is found, a 1280 * NULL pointer otherwise. 1281 */ 1282 __bpf_kfunc struct bpf_key *bpf_lookup_user_key(u32 serial, u64 flags) 1283 { 1284 key_ref_t key_ref; 1285 struct bpf_key *bkey; 1286 1287 if (flags & ~KEY_LOOKUP_ALL) 1288 return NULL; 1289 1290 /* 1291 * Permission check is deferred until the key is used, as the 1292 * intent of the caller is unknown here. 1293 */ 1294 key_ref = lookup_user_key(serial, flags, KEY_DEFER_PERM_CHECK); 1295 if (IS_ERR(key_ref)) 1296 return NULL; 1297 1298 bkey = kmalloc(sizeof(*bkey), GFP_KERNEL); 1299 if (!bkey) { 1300 key_put(key_ref_to_ptr(key_ref)); 1301 return NULL; 1302 } 1303 1304 bkey->key = key_ref_to_ptr(key_ref); 1305 bkey->has_ref = true; 1306 1307 return bkey; 1308 } 1309 1310 /** 1311 * bpf_lookup_system_key - lookup a key by a system-defined ID 1312 * @id: key ID 1313 * 1314 * Obtain a bpf_key structure with a key pointer set to the passed key ID. 1315 * The key pointer is marked as invalid, to prevent bpf_key_put() from 1316 * attempting to decrement the key reference count on that pointer. The key 1317 * pointer set in such way is currently understood only by 1318 * verify_pkcs7_signature(). 1319 * 1320 * Set *id* to one of the values defined in include/linux/verification.h: 1321 * 0 for the primary keyring (immutable keyring of system keys); 1322 * VERIFY_USE_SECONDARY_KEYRING for both the primary and secondary keyring 1323 * (where keys can be added only if they are vouched for by existing keys 1324 * in those keyrings); VERIFY_USE_PLATFORM_KEYRING for the platform 1325 * keyring (primarily used by the integrity subsystem to verify a kexec'ed 1326 * kerned image and, possibly, the initramfs signature). 1327 * 1328 * Return: a bpf_key pointer with an invalid key pointer set from the 1329 * pre-determined ID on success, a NULL pointer otherwise 1330 */ 1331 __bpf_kfunc struct bpf_key *bpf_lookup_system_key(u64 id) 1332 { 1333 struct bpf_key *bkey; 1334 1335 if (system_keyring_id_check(id) < 0) 1336 return NULL; 1337 1338 bkey = kmalloc(sizeof(*bkey), GFP_ATOMIC); 1339 if (!bkey) 1340 return NULL; 1341 1342 bkey->key = (struct key *)(unsigned long)id; 1343 bkey->has_ref = false; 1344 1345 return bkey; 1346 } 1347 1348 /** 1349 * bpf_key_put - decrement key reference count if key is valid and free bpf_key 1350 * @bkey: bpf_key structure 1351 * 1352 * Decrement the reference count of the key inside *bkey*, if the pointer 1353 * is valid, and free *bkey*. 1354 */ 1355 __bpf_kfunc void bpf_key_put(struct bpf_key *bkey) 1356 { 1357 if (bkey->has_ref) 1358 key_put(bkey->key); 1359 1360 kfree(bkey); 1361 } 1362 1363 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION 1364 /** 1365 * bpf_verify_pkcs7_signature - verify a PKCS#7 signature 1366 * @data_ptr: data to verify 1367 * @sig_ptr: signature of the data 1368 * @trusted_keyring: keyring with keys trusted for signature verification 1369 * 1370 * Verify the PKCS#7 signature *sig_ptr* against the supplied *data_ptr* 1371 * with keys in a keyring referenced by *trusted_keyring*. 1372 * 1373 * Return: 0 on success, a negative value on error. 1374 */ 1375 __bpf_kfunc int bpf_verify_pkcs7_signature(struct bpf_dynptr_kern *data_ptr, 1376 struct bpf_dynptr_kern *sig_ptr, 1377 struct bpf_key *trusted_keyring) 1378 { 1379 const void *data, *sig; 1380 u32 data_len, sig_len; 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 data_len = __bpf_dynptr_size(data_ptr); 1398 data = __bpf_dynptr_data(data_ptr, data_len); 1399 sig_len = __bpf_dynptr_size(sig_ptr); 1400 sig = __bpf_dynptr_data(sig_ptr, sig_len); 1401 1402 return verify_pkcs7_signature(data, data_len, sig, sig_len, 1403 trusted_keyring->key, 1404 VERIFYING_UNSPECIFIED_SIGNATURE, NULL, 1405 NULL); 1406 } 1407 #endif /* CONFIG_SYSTEM_DATA_VERIFICATION */ 1408 1409 __bpf_kfunc_end_defs(); 1410 1411 BTF_SET8_START(key_sig_kfunc_set) 1412 BTF_ID_FLAGS(func, bpf_lookup_user_key, KF_ACQUIRE | KF_RET_NULL | KF_SLEEPABLE) 1413 BTF_ID_FLAGS(func, bpf_lookup_system_key, KF_ACQUIRE | KF_RET_NULL) 1414 BTF_ID_FLAGS(func, bpf_key_put, KF_RELEASE) 1415 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION 1416 BTF_ID_FLAGS(func, bpf_verify_pkcs7_signature, KF_SLEEPABLE) 1417 #endif 1418 BTF_SET8_END(key_sig_kfunc_set) 1419 1420 static const struct btf_kfunc_id_set bpf_key_sig_kfunc_set = { 1421 .owner = THIS_MODULE, 1422 .set = &key_sig_kfunc_set, 1423 }; 1424 1425 static int __init bpf_key_sig_kfuncs_init(void) 1426 { 1427 return register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, 1428 &bpf_key_sig_kfunc_set); 1429 } 1430 1431 late_initcall(bpf_key_sig_kfuncs_init); 1432 #endif /* CONFIG_KEYS */ 1433 1434 static const struct bpf_func_proto * 1435 bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1436 { 1437 switch (func_id) { 1438 case BPF_FUNC_map_lookup_elem: 1439 return &bpf_map_lookup_elem_proto; 1440 case BPF_FUNC_map_update_elem: 1441 return &bpf_map_update_elem_proto; 1442 case BPF_FUNC_map_delete_elem: 1443 return &bpf_map_delete_elem_proto; 1444 case BPF_FUNC_map_push_elem: 1445 return &bpf_map_push_elem_proto; 1446 case BPF_FUNC_map_pop_elem: 1447 return &bpf_map_pop_elem_proto; 1448 case BPF_FUNC_map_peek_elem: 1449 return &bpf_map_peek_elem_proto; 1450 case BPF_FUNC_map_lookup_percpu_elem: 1451 return &bpf_map_lookup_percpu_elem_proto; 1452 case BPF_FUNC_ktime_get_ns: 1453 return &bpf_ktime_get_ns_proto; 1454 case BPF_FUNC_ktime_get_boot_ns: 1455 return &bpf_ktime_get_boot_ns_proto; 1456 case BPF_FUNC_tail_call: 1457 return &bpf_tail_call_proto; 1458 case BPF_FUNC_get_current_pid_tgid: 1459 return &bpf_get_current_pid_tgid_proto; 1460 case BPF_FUNC_get_current_task: 1461 return &bpf_get_current_task_proto; 1462 case BPF_FUNC_get_current_task_btf: 1463 return &bpf_get_current_task_btf_proto; 1464 case BPF_FUNC_task_pt_regs: 1465 return &bpf_task_pt_regs_proto; 1466 case BPF_FUNC_get_current_uid_gid: 1467 return &bpf_get_current_uid_gid_proto; 1468 case BPF_FUNC_get_current_comm: 1469 return &bpf_get_current_comm_proto; 1470 case BPF_FUNC_trace_printk: 1471 return bpf_get_trace_printk_proto(); 1472 case BPF_FUNC_get_smp_processor_id: 1473 return &bpf_get_smp_processor_id_proto; 1474 case BPF_FUNC_get_numa_node_id: 1475 return &bpf_get_numa_node_id_proto; 1476 case BPF_FUNC_perf_event_read: 1477 return &bpf_perf_event_read_proto; 1478 case BPF_FUNC_current_task_under_cgroup: 1479 return &bpf_current_task_under_cgroup_proto; 1480 case BPF_FUNC_get_prandom_u32: 1481 return &bpf_get_prandom_u32_proto; 1482 case BPF_FUNC_probe_write_user: 1483 return security_locked_down(LOCKDOWN_BPF_WRITE_USER) < 0 ? 1484 NULL : bpf_get_probe_write_proto(); 1485 case BPF_FUNC_probe_read_user: 1486 return &bpf_probe_read_user_proto; 1487 case BPF_FUNC_probe_read_kernel: 1488 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1489 NULL : &bpf_probe_read_kernel_proto; 1490 case BPF_FUNC_probe_read_user_str: 1491 return &bpf_probe_read_user_str_proto; 1492 case BPF_FUNC_probe_read_kernel_str: 1493 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1494 NULL : &bpf_probe_read_kernel_str_proto; 1495 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 1496 case BPF_FUNC_probe_read: 1497 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1498 NULL : &bpf_probe_read_compat_proto; 1499 case BPF_FUNC_probe_read_str: 1500 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1501 NULL : &bpf_probe_read_compat_str_proto; 1502 #endif 1503 #ifdef CONFIG_CGROUPS 1504 case BPF_FUNC_cgrp_storage_get: 1505 return &bpf_cgrp_storage_get_proto; 1506 case BPF_FUNC_cgrp_storage_delete: 1507 return &bpf_cgrp_storage_delete_proto; 1508 #endif 1509 case BPF_FUNC_send_signal: 1510 return &bpf_send_signal_proto; 1511 case BPF_FUNC_send_signal_thread: 1512 return &bpf_send_signal_thread_proto; 1513 case BPF_FUNC_perf_event_read_value: 1514 return &bpf_perf_event_read_value_proto; 1515 case BPF_FUNC_get_ns_current_pid_tgid: 1516 return &bpf_get_ns_current_pid_tgid_proto; 1517 case BPF_FUNC_ringbuf_output: 1518 return &bpf_ringbuf_output_proto; 1519 case BPF_FUNC_ringbuf_reserve: 1520 return &bpf_ringbuf_reserve_proto; 1521 case BPF_FUNC_ringbuf_submit: 1522 return &bpf_ringbuf_submit_proto; 1523 case BPF_FUNC_ringbuf_discard: 1524 return &bpf_ringbuf_discard_proto; 1525 case BPF_FUNC_ringbuf_query: 1526 return &bpf_ringbuf_query_proto; 1527 case BPF_FUNC_jiffies64: 1528 return &bpf_jiffies64_proto; 1529 case BPF_FUNC_get_task_stack: 1530 return &bpf_get_task_stack_proto; 1531 case BPF_FUNC_copy_from_user: 1532 return &bpf_copy_from_user_proto; 1533 case BPF_FUNC_copy_from_user_task: 1534 return &bpf_copy_from_user_task_proto; 1535 case BPF_FUNC_snprintf_btf: 1536 return &bpf_snprintf_btf_proto; 1537 case BPF_FUNC_per_cpu_ptr: 1538 return &bpf_per_cpu_ptr_proto; 1539 case BPF_FUNC_this_cpu_ptr: 1540 return &bpf_this_cpu_ptr_proto; 1541 case BPF_FUNC_task_storage_get: 1542 if (bpf_prog_check_recur(prog)) 1543 return &bpf_task_storage_get_recur_proto; 1544 return &bpf_task_storage_get_proto; 1545 case BPF_FUNC_task_storage_delete: 1546 if (bpf_prog_check_recur(prog)) 1547 return &bpf_task_storage_delete_recur_proto; 1548 return &bpf_task_storage_delete_proto; 1549 case BPF_FUNC_for_each_map_elem: 1550 return &bpf_for_each_map_elem_proto; 1551 case BPF_FUNC_snprintf: 1552 return &bpf_snprintf_proto; 1553 case BPF_FUNC_get_func_ip: 1554 return &bpf_get_func_ip_proto_tracing; 1555 case BPF_FUNC_get_branch_snapshot: 1556 return &bpf_get_branch_snapshot_proto; 1557 case BPF_FUNC_find_vma: 1558 return &bpf_find_vma_proto; 1559 case BPF_FUNC_trace_vprintk: 1560 return bpf_get_trace_vprintk_proto(); 1561 default: 1562 return bpf_base_func_proto(func_id); 1563 } 1564 } 1565 1566 static const struct bpf_func_proto * 1567 kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1568 { 1569 switch (func_id) { 1570 case BPF_FUNC_perf_event_output: 1571 return &bpf_perf_event_output_proto; 1572 case BPF_FUNC_get_stackid: 1573 return &bpf_get_stackid_proto; 1574 case BPF_FUNC_get_stack: 1575 return &bpf_get_stack_proto; 1576 #ifdef CONFIG_BPF_KPROBE_OVERRIDE 1577 case BPF_FUNC_override_return: 1578 return &bpf_override_return_proto; 1579 #endif 1580 case BPF_FUNC_get_func_ip: 1581 if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI) 1582 return &bpf_get_func_ip_proto_kprobe_multi; 1583 if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI) 1584 return &bpf_get_func_ip_proto_uprobe_multi; 1585 return &bpf_get_func_ip_proto_kprobe; 1586 case BPF_FUNC_get_attach_cookie: 1587 if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI) 1588 return &bpf_get_attach_cookie_proto_kmulti; 1589 if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI) 1590 return &bpf_get_attach_cookie_proto_umulti; 1591 return &bpf_get_attach_cookie_proto_trace; 1592 default: 1593 return bpf_tracing_func_proto(func_id, prog); 1594 } 1595 } 1596 1597 /* bpf+kprobe programs can access fields of 'struct pt_regs' */ 1598 static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type, 1599 const struct bpf_prog *prog, 1600 struct bpf_insn_access_aux *info) 1601 { 1602 if (off < 0 || off >= sizeof(struct pt_regs)) 1603 return false; 1604 if (type != BPF_READ) 1605 return false; 1606 if (off % size != 0) 1607 return false; 1608 /* 1609 * Assertion for 32 bit to make sure last 8 byte access 1610 * (BPF_DW) to the last 4 byte member is disallowed. 1611 */ 1612 if (off + size > sizeof(struct pt_regs)) 1613 return false; 1614 1615 return true; 1616 } 1617 1618 const struct bpf_verifier_ops kprobe_verifier_ops = { 1619 .get_func_proto = kprobe_prog_func_proto, 1620 .is_valid_access = kprobe_prog_is_valid_access, 1621 }; 1622 1623 const struct bpf_prog_ops kprobe_prog_ops = { 1624 }; 1625 1626 BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map, 1627 u64, flags, void *, data, u64, size) 1628 { 1629 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1630 1631 /* 1632 * r1 points to perf tracepoint buffer where first 8 bytes are hidden 1633 * from bpf program and contain a pointer to 'struct pt_regs'. Fetch it 1634 * from there and call the same bpf_perf_event_output() helper inline. 1635 */ 1636 return ____bpf_perf_event_output(regs, map, flags, data, size); 1637 } 1638 1639 static const struct bpf_func_proto bpf_perf_event_output_proto_tp = { 1640 .func = bpf_perf_event_output_tp, 1641 .gpl_only = true, 1642 .ret_type = RET_INTEGER, 1643 .arg1_type = ARG_PTR_TO_CTX, 1644 .arg2_type = ARG_CONST_MAP_PTR, 1645 .arg3_type = ARG_ANYTHING, 1646 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1647 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 1648 }; 1649 1650 BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map, 1651 u64, flags) 1652 { 1653 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1654 1655 /* 1656 * Same comment as in bpf_perf_event_output_tp(), only that this time 1657 * the other helper's function body cannot be inlined due to being 1658 * external, thus we need to call raw helper function. 1659 */ 1660 return bpf_get_stackid((unsigned long) regs, (unsigned long) map, 1661 flags, 0, 0); 1662 } 1663 1664 static const struct bpf_func_proto bpf_get_stackid_proto_tp = { 1665 .func = bpf_get_stackid_tp, 1666 .gpl_only = true, 1667 .ret_type = RET_INTEGER, 1668 .arg1_type = ARG_PTR_TO_CTX, 1669 .arg2_type = ARG_CONST_MAP_PTR, 1670 .arg3_type = ARG_ANYTHING, 1671 }; 1672 1673 BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size, 1674 u64, flags) 1675 { 1676 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1677 1678 return bpf_get_stack((unsigned long) regs, (unsigned long) buf, 1679 (unsigned long) size, flags, 0); 1680 } 1681 1682 static const struct bpf_func_proto bpf_get_stack_proto_tp = { 1683 .func = bpf_get_stack_tp, 1684 .gpl_only = true, 1685 .ret_type = RET_INTEGER, 1686 .arg1_type = ARG_PTR_TO_CTX, 1687 .arg2_type = ARG_PTR_TO_UNINIT_MEM, 1688 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1689 .arg4_type = ARG_ANYTHING, 1690 }; 1691 1692 static const struct bpf_func_proto * 1693 tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1694 { 1695 switch (func_id) { 1696 case BPF_FUNC_perf_event_output: 1697 return &bpf_perf_event_output_proto_tp; 1698 case BPF_FUNC_get_stackid: 1699 return &bpf_get_stackid_proto_tp; 1700 case BPF_FUNC_get_stack: 1701 return &bpf_get_stack_proto_tp; 1702 case BPF_FUNC_get_attach_cookie: 1703 return &bpf_get_attach_cookie_proto_trace; 1704 default: 1705 return bpf_tracing_func_proto(func_id, prog); 1706 } 1707 } 1708 1709 static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type, 1710 const struct bpf_prog *prog, 1711 struct bpf_insn_access_aux *info) 1712 { 1713 if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE) 1714 return false; 1715 if (type != BPF_READ) 1716 return false; 1717 if (off % size != 0) 1718 return false; 1719 1720 BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(__u64)); 1721 return true; 1722 } 1723 1724 const struct bpf_verifier_ops tracepoint_verifier_ops = { 1725 .get_func_proto = tp_prog_func_proto, 1726 .is_valid_access = tp_prog_is_valid_access, 1727 }; 1728 1729 const struct bpf_prog_ops tracepoint_prog_ops = { 1730 }; 1731 1732 BPF_CALL_3(bpf_perf_prog_read_value, struct bpf_perf_event_data_kern *, ctx, 1733 struct bpf_perf_event_value *, buf, u32, size) 1734 { 1735 int err = -EINVAL; 1736 1737 if (unlikely(size != sizeof(struct bpf_perf_event_value))) 1738 goto clear; 1739 err = perf_event_read_local(ctx->event, &buf->counter, &buf->enabled, 1740 &buf->running); 1741 if (unlikely(err)) 1742 goto clear; 1743 return 0; 1744 clear: 1745 memset(buf, 0, size); 1746 return err; 1747 } 1748 1749 static const struct bpf_func_proto bpf_perf_prog_read_value_proto = { 1750 .func = bpf_perf_prog_read_value, 1751 .gpl_only = true, 1752 .ret_type = RET_INTEGER, 1753 .arg1_type = ARG_PTR_TO_CTX, 1754 .arg2_type = ARG_PTR_TO_UNINIT_MEM, 1755 .arg3_type = ARG_CONST_SIZE, 1756 }; 1757 1758 BPF_CALL_4(bpf_read_branch_records, struct bpf_perf_event_data_kern *, ctx, 1759 void *, buf, u32, size, u64, flags) 1760 { 1761 static const u32 br_entry_size = sizeof(struct perf_branch_entry); 1762 struct perf_branch_stack *br_stack = ctx->data->br_stack; 1763 u32 to_copy; 1764 1765 if (unlikely(flags & ~BPF_F_GET_BRANCH_RECORDS_SIZE)) 1766 return -EINVAL; 1767 1768 if (unlikely(!(ctx->data->sample_flags & PERF_SAMPLE_BRANCH_STACK))) 1769 return -ENOENT; 1770 1771 if (unlikely(!br_stack)) 1772 return -ENOENT; 1773 1774 if (flags & BPF_F_GET_BRANCH_RECORDS_SIZE) 1775 return br_stack->nr * br_entry_size; 1776 1777 if (!buf || (size % br_entry_size != 0)) 1778 return -EINVAL; 1779 1780 to_copy = min_t(u32, br_stack->nr * br_entry_size, size); 1781 memcpy(buf, br_stack->entries, to_copy); 1782 1783 return to_copy; 1784 } 1785 1786 static const struct bpf_func_proto bpf_read_branch_records_proto = { 1787 .func = bpf_read_branch_records, 1788 .gpl_only = true, 1789 .ret_type = RET_INTEGER, 1790 .arg1_type = ARG_PTR_TO_CTX, 1791 .arg2_type = ARG_PTR_TO_MEM_OR_NULL, 1792 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1793 .arg4_type = ARG_ANYTHING, 1794 }; 1795 1796 static const struct bpf_func_proto * 1797 pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1798 { 1799 switch (func_id) { 1800 case BPF_FUNC_perf_event_output: 1801 return &bpf_perf_event_output_proto_tp; 1802 case BPF_FUNC_get_stackid: 1803 return &bpf_get_stackid_proto_pe; 1804 case BPF_FUNC_get_stack: 1805 return &bpf_get_stack_proto_pe; 1806 case BPF_FUNC_perf_prog_read_value: 1807 return &bpf_perf_prog_read_value_proto; 1808 case BPF_FUNC_read_branch_records: 1809 return &bpf_read_branch_records_proto; 1810 case BPF_FUNC_get_attach_cookie: 1811 return &bpf_get_attach_cookie_proto_pe; 1812 default: 1813 return bpf_tracing_func_proto(func_id, prog); 1814 } 1815 } 1816 1817 /* 1818 * bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp 1819 * to avoid potential recursive reuse issue when/if tracepoints are added 1820 * inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack. 1821 * 1822 * Since raw tracepoints run despite bpf_prog_active, support concurrent usage 1823 * in normal, irq, and nmi context. 1824 */ 1825 struct bpf_raw_tp_regs { 1826 struct pt_regs regs[3]; 1827 }; 1828 static DEFINE_PER_CPU(struct bpf_raw_tp_regs, bpf_raw_tp_regs); 1829 static DEFINE_PER_CPU(int, bpf_raw_tp_nest_level); 1830 static struct pt_regs *get_bpf_raw_tp_regs(void) 1831 { 1832 struct bpf_raw_tp_regs *tp_regs = this_cpu_ptr(&bpf_raw_tp_regs); 1833 int nest_level = this_cpu_inc_return(bpf_raw_tp_nest_level); 1834 1835 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(tp_regs->regs))) { 1836 this_cpu_dec(bpf_raw_tp_nest_level); 1837 return ERR_PTR(-EBUSY); 1838 } 1839 1840 return &tp_regs->regs[nest_level - 1]; 1841 } 1842 1843 static void put_bpf_raw_tp_regs(void) 1844 { 1845 this_cpu_dec(bpf_raw_tp_nest_level); 1846 } 1847 1848 BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args, 1849 struct bpf_map *, map, u64, flags, void *, data, u64, size) 1850 { 1851 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1852 int ret; 1853 1854 if (IS_ERR(regs)) 1855 return PTR_ERR(regs); 1856 1857 perf_fetch_caller_regs(regs); 1858 ret = ____bpf_perf_event_output(regs, map, flags, data, size); 1859 1860 put_bpf_raw_tp_regs(); 1861 return ret; 1862 } 1863 1864 static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = { 1865 .func = bpf_perf_event_output_raw_tp, 1866 .gpl_only = true, 1867 .ret_type = RET_INTEGER, 1868 .arg1_type = ARG_PTR_TO_CTX, 1869 .arg2_type = ARG_CONST_MAP_PTR, 1870 .arg3_type = ARG_ANYTHING, 1871 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1872 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 1873 }; 1874 1875 extern const struct bpf_func_proto bpf_skb_output_proto; 1876 extern const struct bpf_func_proto bpf_xdp_output_proto; 1877 extern const struct bpf_func_proto bpf_xdp_get_buff_len_trace_proto; 1878 1879 BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args, 1880 struct bpf_map *, map, u64, flags) 1881 { 1882 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1883 int ret; 1884 1885 if (IS_ERR(regs)) 1886 return PTR_ERR(regs); 1887 1888 perf_fetch_caller_regs(regs); 1889 /* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */ 1890 ret = bpf_get_stackid((unsigned long) regs, (unsigned long) map, 1891 flags, 0, 0); 1892 put_bpf_raw_tp_regs(); 1893 return ret; 1894 } 1895 1896 static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = { 1897 .func = bpf_get_stackid_raw_tp, 1898 .gpl_only = true, 1899 .ret_type = RET_INTEGER, 1900 .arg1_type = ARG_PTR_TO_CTX, 1901 .arg2_type = ARG_CONST_MAP_PTR, 1902 .arg3_type = ARG_ANYTHING, 1903 }; 1904 1905 BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args, 1906 void *, buf, u32, size, u64, flags) 1907 { 1908 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1909 int ret; 1910 1911 if (IS_ERR(regs)) 1912 return PTR_ERR(regs); 1913 1914 perf_fetch_caller_regs(regs); 1915 ret = bpf_get_stack((unsigned long) regs, (unsigned long) buf, 1916 (unsigned long) size, flags, 0); 1917 put_bpf_raw_tp_regs(); 1918 return ret; 1919 } 1920 1921 static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = { 1922 .func = bpf_get_stack_raw_tp, 1923 .gpl_only = true, 1924 .ret_type = RET_INTEGER, 1925 .arg1_type = ARG_PTR_TO_CTX, 1926 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1927 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1928 .arg4_type = ARG_ANYTHING, 1929 }; 1930 1931 static const struct bpf_func_proto * 1932 raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1933 { 1934 switch (func_id) { 1935 case BPF_FUNC_perf_event_output: 1936 return &bpf_perf_event_output_proto_raw_tp; 1937 case BPF_FUNC_get_stackid: 1938 return &bpf_get_stackid_proto_raw_tp; 1939 case BPF_FUNC_get_stack: 1940 return &bpf_get_stack_proto_raw_tp; 1941 default: 1942 return bpf_tracing_func_proto(func_id, prog); 1943 } 1944 } 1945 1946 const struct bpf_func_proto * 1947 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1948 { 1949 const struct bpf_func_proto *fn; 1950 1951 switch (func_id) { 1952 #ifdef CONFIG_NET 1953 case BPF_FUNC_skb_output: 1954 return &bpf_skb_output_proto; 1955 case BPF_FUNC_xdp_output: 1956 return &bpf_xdp_output_proto; 1957 case BPF_FUNC_skc_to_tcp6_sock: 1958 return &bpf_skc_to_tcp6_sock_proto; 1959 case BPF_FUNC_skc_to_tcp_sock: 1960 return &bpf_skc_to_tcp_sock_proto; 1961 case BPF_FUNC_skc_to_tcp_timewait_sock: 1962 return &bpf_skc_to_tcp_timewait_sock_proto; 1963 case BPF_FUNC_skc_to_tcp_request_sock: 1964 return &bpf_skc_to_tcp_request_sock_proto; 1965 case BPF_FUNC_skc_to_udp6_sock: 1966 return &bpf_skc_to_udp6_sock_proto; 1967 case BPF_FUNC_skc_to_unix_sock: 1968 return &bpf_skc_to_unix_sock_proto; 1969 case BPF_FUNC_skc_to_mptcp_sock: 1970 return &bpf_skc_to_mptcp_sock_proto; 1971 case BPF_FUNC_sk_storage_get: 1972 return &bpf_sk_storage_get_tracing_proto; 1973 case BPF_FUNC_sk_storage_delete: 1974 return &bpf_sk_storage_delete_tracing_proto; 1975 case BPF_FUNC_sock_from_file: 1976 return &bpf_sock_from_file_proto; 1977 case BPF_FUNC_get_socket_cookie: 1978 return &bpf_get_socket_ptr_cookie_proto; 1979 case BPF_FUNC_xdp_get_buff_len: 1980 return &bpf_xdp_get_buff_len_trace_proto; 1981 #endif 1982 case BPF_FUNC_seq_printf: 1983 return prog->expected_attach_type == BPF_TRACE_ITER ? 1984 &bpf_seq_printf_proto : 1985 NULL; 1986 case BPF_FUNC_seq_write: 1987 return prog->expected_attach_type == BPF_TRACE_ITER ? 1988 &bpf_seq_write_proto : 1989 NULL; 1990 case BPF_FUNC_seq_printf_btf: 1991 return prog->expected_attach_type == BPF_TRACE_ITER ? 1992 &bpf_seq_printf_btf_proto : 1993 NULL; 1994 case BPF_FUNC_d_path: 1995 return &bpf_d_path_proto; 1996 case BPF_FUNC_get_func_arg: 1997 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_proto : NULL; 1998 case BPF_FUNC_get_func_ret: 1999 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_ret_proto : NULL; 2000 case BPF_FUNC_get_func_arg_cnt: 2001 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_cnt_proto : NULL; 2002 case BPF_FUNC_get_attach_cookie: 2003 return bpf_prog_has_trampoline(prog) ? &bpf_get_attach_cookie_proto_tracing : NULL; 2004 default: 2005 fn = raw_tp_prog_func_proto(func_id, prog); 2006 if (!fn && prog->expected_attach_type == BPF_TRACE_ITER) 2007 fn = bpf_iter_get_func_proto(func_id, prog); 2008 return fn; 2009 } 2010 } 2011 2012 static bool raw_tp_prog_is_valid_access(int off, int size, 2013 enum bpf_access_type type, 2014 const struct bpf_prog *prog, 2015 struct bpf_insn_access_aux *info) 2016 { 2017 return bpf_tracing_ctx_access(off, size, type); 2018 } 2019 2020 static bool tracing_prog_is_valid_access(int off, int size, 2021 enum bpf_access_type type, 2022 const struct bpf_prog *prog, 2023 struct bpf_insn_access_aux *info) 2024 { 2025 return bpf_tracing_btf_ctx_access(off, size, type, prog, info); 2026 } 2027 2028 int __weak bpf_prog_test_run_tracing(struct bpf_prog *prog, 2029 const union bpf_attr *kattr, 2030 union bpf_attr __user *uattr) 2031 { 2032 return -ENOTSUPP; 2033 } 2034 2035 const struct bpf_verifier_ops raw_tracepoint_verifier_ops = { 2036 .get_func_proto = raw_tp_prog_func_proto, 2037 .is_valid_access = raw_tp_prog_is_valid_access, 2038 }; 2039 2040 const struct bpf_prog_ops raw_tracepoint_prog_ops = { 2041 #ifdef CONFIG_NET 2042 .test_run = bpf_prog_test_run_raw_tp, 2043 #endif 2044 }; 2045 2046 const struct bpf_verifier_ops tracing_verifier_ops = { 2047 .get_func_proto = tracing_prog_func_proto, 2048 .is_valid_access = tracing_prog_is_valid_access, 2049 }; 2050 2051 const struct bpf_prog_ops tracing_prog_ops = { 2052 .test_run = bpf_prog_test_run_tracing, 2053 }; 2054 2055 static bool raw_tp_writable_prog_is_valid_access(int off, int size, 2056 enum bpf_access_type type, 2057 const struct bpf_prog *prog, 2058 struct bpf_insn_access_aux *info) 2059 { 2060 if (off == 0) { 2061 if (size != sizeof(u64) || type != BPF_READ) 2062 return false; 2063 info->reg_type = PTR_TO_TP_BUFFER; 2064 } 2065 return raw_tp_prog_is_valid_access(off, size, type, prog, info); 2066 } 2067 2068 const struct bpf_verifier_ops raw_tracepoint_writable_verifier_ops = { 2069 .get_func_proto = raw_tp_prog_func_proto, 2070 .is_valid_access = raw_tp_writable_prog_is_valid_access, 2071 }; 2072 2073 const struct bpf_prog_ops raw_tracepoint_writable_prog_ops = { 2074 }; 2075 2076 static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type, 2077 const struct bpf_prog *prog, 2078 struct bpf_insn_access_aux *info) 2079 { 2080 const int size_u64 = sizeof(u64); 2081 2082 if (off < 0 || off >= sizeof(struct bpf_perf_event_data)) 2083 return false; 2084 if (type != BPF_READ) 2085 return false; 2086 if (off % size != 0) { 2087 if (sizeof(unsigned long) != 4) 2088 return false; 2089 if (size != 8) 2090 return false; 2091 if (off % size != 4) 2092 return false; 2093 } 2094 2095 switch (off) { 2096 case bpf_ctx_range(struct bpf_perf_event_data, sample_period): 2097 bpf_ctx_record_field_size(info, size_u64); 2098 if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) 2099 return false; 2100 break; 2101 case bpf_ctx_range(struct bpf_perf_event_data, addr): 2102 bpf_ctx_record_field_size(info, size_u64); 2103 if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) 2104 return false; 2105 break; 2106 default: 2107 if (size != sizeof(long)) 2108 return false; 2109 } 2110 2111 return true; 2112 } 2113 2114 static u32 pe_prog_convert_ctx_access(enum bpf_access_type type, 2115 const struct bpf_insn *si, 2116 struct bpf_insn *insn_buf, 2117 struct bpf_prog *prog, u32 *target_size) 2118 { 2119 struct bpf_insn *insn = insn_buf; 2120 2121 switch (si->off) { 2122 case offsetof(struct bpf_perf_event_data, sample_period): 2123 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 2124 data), si->dst_reg, si->src_reg, 2125 offsetof(struct bpf_perf_event_data_kern, data)); 2126 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, 2127 bpf_target_off(struct perf_sample_data, period, 8, 2128 target_size)); 2129 break; 2130 case offsetof(struct bpf_perf_event_data, addr): 2131 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 2132 data), si->dst_reg, si->src_reg, 2133 offsetof(struct bpf_perf_event_data_kern, data)); 2134 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, 2135 bpf_target_off(struct perf_sample_data, addr, 8, 2136 target_size)); 2137 break; 2138 default: 2139 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 2140 regs), si->dst_reg, si->src_reg, 2141 offsetof(struct bpf_perf_event_data_kern, regs)); 2142 *insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg, 2143 si->off); 2144 break; 2145 } 2146 2147 return insn - insn_buf; 2148 } 2149 2150 const struct bpf_verifier_ops perf_event_verifier_ops = { 2151 .get_func_proto = pe_prog_func_proto, 2152 .is_valid_access = pe_prog_is_valid_access, 2153 .convert_ctx_access = pe_prog_convert_ctx_access, 2154 }; 2155 2156 const struct bpf_prog_ops perf_event_prog_ops = { 2157 }; 2158 2159 static DEFINE_MUTEX(bpf_event_mutex); 2160 2161 #define BPF_TRACE_MAX_PROGS 64 2162 2163 int perf_event_attach_bpf_prog(struct perf_event *event, 2164 struct bpf_prog *prog, 2165 u64 bpf_cookie) 2166 { 2167 struct bpf_prog_array *old_array; 2168 struct bpf_prog_array *new_array; 2169 int ret = -EEXIST; 2170 2171 /* 2172 * Kprobe override only works if they are on the function entry, 2173 * and only if they are on the opt-in list. 2174 */ 2175 if (prog->kprobe_override && 2176 (!trace_kprobe_on_func_entry(event->tp_event) || 2177 !trace_kprobe_error_injectable(event->tp_event))) 2178 return -EINVAL; 2179 2180 mutex_lock(&bpf_event_mutex); 2181 2182 if (event->prog) 2183 goto unlock; 2184 2185 old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); 2186 if (old_array && 2187 bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) { 2188 ret = -E2BIG; 2189 goto unlock; 2190 } 2191 2192 ret = bpf_prog_array_copy(old_array, NULL, prog, bpf_cookie, &new_array); 2193 if (ret < 0) 2194 goto unlock; 2195 2196 /* set the new array to event->tp_event and set event->prog */ 2197 event->prog = prog; 2198 event->bpf_cookie = bpf_cookie; 2199 rcu_assign_pointer(event->tp_event->prog_array, new_array); 2200 bpf_prog_array_free_sleepable(old_array); 2201 2202 unlock: 2203 mutex_unlock(&bpf_event_mutex); 2204 return ret; 2205 } 2206 2207 void perf_event_detach_bpf_prog(struct perf_event *event) 2208 { 2209 struct bpf_prog_array *old_array; 2210 struct bpf_prog_array *new_array; 2211 int ret; 2212 2213 mutex_lock(&bpf_event_mutex); 2214 2215 if (!event->prog) 2216 goto unlock; 2217 2218 old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); 2219 ret = bpf_prog_array_copy(old_array, event->prog, NULL, 0, &new_array); 2220 if (ret == -ENOENT) 2221 goto unlock; 2222 if (ret < 0) { 2223 bpf_prog_array_delete_safe(old_array, event->prog); 2224 } else { 2225 rcu_assign_pointer(event->tp_event->prog_array, new_array); 2226 bpf_prog_array_free_sleepable(old_array); 2227 } 2228 2229 bpf_prog_put(event->prog); 2230 event->prog = NULL; 2231 2232 unlock: 2233 mutex_unlock(&bpf_event_mutex); 2234 } 2235 2236 int perf_event_query_prog_array(struct perf_event *event, void __user *info) 2237 { 2238 struct perf_event_query_bpf __user *uquery = info; 2239 struct perf_event_query_bpf query = {}; 2240 struct bpf_prog_array *progs; 2241 u32 *ids, prog_cnt, ids_len; 2242 int ret; 2243 2244 if (!perfmon_capable()) 2245 return -EPERM; 2246 if (event->attr.type != PERF_TYPE_TRACEPOINT) 2247 return -EINVAL; 2248 if (copy_from_user(&query, uquery, sizeof(query))) 2249 return -EFAULT; 2250 2251 ids_len = query.ids_len; 2252 if (ids_len > BPF_TRACE_MAX_PROGS) 2253 return -E2BIG; 2254 ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN); 2255 if (!ids) 2256 return -ENOMEM; 2257 /* 2258 * The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which 2259 * is required when user only wants to check for uquery->prog_cnt. 2260 * There is no need to check for it since the case is handled 2261 * gracefully in bpf_prog_array_copy_info. 2262 */ 2263 2264 mutex_lock(&bpf_event_mutex); 2265 progs = bpf_event_rcu_dereference(event->tp_event->prog_array); 2266 ret = bpf_prog_array_copy_info(progs, ids, ids_len, &prog_cnt); 2267 mutex_unlock(&bpf_event_mutex); 2268 2269 if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) || 2270 copy_to_user(uquery->ids, ids, ids_len * sizeof(u32))) 2271 ret = -EFAULT; 2272 2273 kfree(ids); 2274 return ret; 2275 } 2276 2277 extern struct bpf_raw_event_map __start__bpf_raw_tp[]; 2278 extern struct bpf_raw_event_map __stop__bpf_raw_tp[]; 2279 2280 struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name) 2281 { 2282 struct bpf_raw_event_map *btp = __start__bpf_raw_tp; 2283 2284 for (; btp < __stop__bpf_raw_tp; btp++) { 2285 if (!strcmp(btp->tp->name, name)) 2286 return btp; 2287 } 2288 2289 return bpf_get_raw_tracepoint_module(name); 2290 } 2291 2292 void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp) 2293 { 2294 struct module *mod; 2295 2296 preempt_disable(); 2297 mod = __module_address((unsigned long)btp); 2298 module_put(mod); 2299 preempt_enable(); 2300 } 2301 2302 static __always_inline 2303 void __bpf_trace_run(struct bpf_prog *prog, u64 *args) 2304 { 2305 cant_sleep(); 2306 if (unlikely(this_cpu_inc_return(*(prog->active)) != 1)) { 2307 bpf_prog_inc_misses_counter(prog); 2308 goto out; 2309 } 2310 rcu_read_lock(); 2311 (void) bpf_prog_run(prog, args); 2312 rcu_read_unlock(); 2313 out: 2314 this_cpu_dec(*(prog->active)); 2315 } 2316 2317 #define UNPACK(...) __VA_ARGS__ 2318 #define REPEAT_1(FN, DL, X, ...) FN(X) 2319 #define REPEAT_2(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__) 2320 #define REPEAT_3(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_2(FN, DL, __VA_ARGS__) 2321 #define REPEAT_4(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_3(FN, DL, __VA_ARGS__) 2322 #define REPEAT_5(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_4(FN, DL, __VA_ARGS__) 2323 #define REPEAT_6(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_5(FN, DL, __VA_ARGS__) 2324 #define REPEAT_7(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_6(FN, DL, __VA_ARGS__) 2325 #define REPEAT_8(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_7(FN, DL, __VA_ARGS__) 2326 #define REPEAT_9(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_8(FN, DL, __VA_ARGS__) 2327 #define REPEAT_10(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_9(FN, DL, __VA_ARGS__) 2328 #define REPEAT_11(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_10(FN, DL, __VA_ARGS__) 2329 #define REPEAT_12(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_11(FN, DL, __VA_ARGS__) 2330 #define REPEAT(X, FN, DL, ...) REPEAT_##X(FN, DL, __VA_ARGS__) 2331 2332 #define SARG(X) u64 arg##X 2333 #define COPY(X) args[X] = arg##X 2334 2335 #define __DL_COM (,) 2336 #define __DL_SEM (;) 2337 2338 #define __SEQ_0_11 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 2339 2340 #define BPF_TRACE_DEFN_x(x) \ 2341 void bpf_trace_run##x(struct bpf_prog *prog, \ 2342 REPEAT(x, SARG, __DL_COM, __SEQ_0_11)) \ 2343 { \ 2344 u64 args[x]; \ 2345 REPEAT(x, COPY, __DL_SEM, __SEQ_0_11); \ 2346 __bpf_trace_run(prog, args); \ 2347 } \ 2348 EXPORT_SYMBOL_GPL(bpf_trace_run##x) 2349 BPF_TRACE_DEFN_x(1); 2350 BPF_TRACE_DEFN_x(2); 2351 BPF_TRACE_DEFN_x(3); 2352 BPF_TRACE_DEFN_x(4); 2353 BPF_TRACE_DEFN_x(5); 2354 BPF_TRACE_DEFN_x(6); 2355 BPF_TRACE_DEFN_x(7); 2356 BPF_TRACE_DEFN_x(8); 2357 BPF_TRACE_DEFN_x(9); 2358 BPF_TRACE_DEFN_x(10); 2359 BPF_TRACE_DEFN_x(11); 2360 BPF_TRACE_DEFN_x(12); 2361 2362 static int __bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog) 2363 { 2364 struct tracepoint *tp = btp->tp; 2365 2366 /* 2367 * check that program doesn't access arguments beyond what's 2368 * available in this tracepoint 2369 */ 2370 if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64)) 2371 return -EINVAL; 2372 2373 if (prog->aux->max_tp_access > btp->writable_size) 2374 return -EINVAL; 2375 2376 return tracepoint_probe_register_may_exist(tp, (void *)btp->bpf_func, 2377 prog); 2378 } 2379 2380 int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog) 2381 { 2382 return __bpf_probe_register(btp, prog); 2383 } 2384 2385 int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_prog *prog) 2386 { 2387 return tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, prog); 2388 } 2389 2390 int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id, 2391 u32 *fd_type, const char **buf, 2392 u64 *probe_offset, u64 *probe_addr, 2393 unsigned long *missed) 2394 { 2395 bool is_tracepoint, is_syscall_tp; 2396 struct bpf_prog *prog; 2397 int flags, err = 0; 2398 2399 prog = event->prog; 2400 if (!prog) 2401 return -ENOENT; 2402 2403 /* not supporting BPF_PROG_TYPE_PERF_EVENT yet */ 2404 if (prog->type == BPF_PROG_TYPE_PERF_EVENT) 2405 return -EOPNOTSUPP; 2406 2407 *prog_id = prog->aux->id; 2408 flags = event->tp_event->flags; 2409 is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT; 2410 is_syscall_tp = is_syscall_trace_event(event->tp_event); 2411 2412 if (is_tracepoint || is_syscall_tp) { 2413 *buf = is_tracepoint ? event->tp_event->tp->name 2414 : event->tp_event->name; 2415 /* We allow NULL pointer for tracepoint */ 2416 if (fd_type) 2417 *fd_type = BPF_FD_TYPE_TRACEPOINT; 2418 if (probe_offset) 2419 *probe_offset = 0x0; 2420 if (probe_addr) 2421 *probe_addr = 0x0; 2422 } else { 2423 /* kprobe/uprobe */ 2424 err = -EOPNOTSUPP; 2425 #ifdef CONFIG_KPROBE_EVENTS 2426 if (flags & TRACE_EVENT_FL_KPROBE) 2427 err = bpf_get_kprobe_info(event, fd_type, buf, 2428 probe_offset, probe_addr, missed, 2429 event->attr.type == PERF_TYPE_TRACEPOINT); 2430 #endif 2431 #ifdef CONFIG_UPROBE_EVENTS 2432 if (flags & TRACE_EVENT_FL_UPROBE) 2433 err = bpf_get_uprobe_info(event, fd_type, buf, 2434 probe_offset, probe_addr, 2435 event->attr.type == PERF_TYPE_TRACEPOINT); 2436 #endif 2437 } 2438 2439 return err; 2440 } 2441 2442 static int __init send_signal_irq_work_init(void) 2443 { 2444 int cpu; 2445 struct send_signal_irq_work *work; 2446 2447 for_each_possible_cpu(cpu) { 2448 work = per_cpu_ptr(&send_signal_work, cpu); 2449 init_irq_work(&work->irq_work, do_bpf_send_signal); 2450 } 2451 return 0; 2452 } 2453 2454 subsys_initcall(send_signal_irq_work_init); 2455 2456 #ifdef CONFIG_MODULES 2457 static int bpf_event_notify(struct notifier_block *nb, unsigned long op, 2458 void *module) 2459 { 2460 struct bpf_trace_module *btm, *tmp; 2461 struct module *mod = module; 2462 int ret = 0; 2463 2464 if (mod->num_bpf_raw_events == 0 || 2465 (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING)) 2466 goto out; 2467 2468 mutex_lock(&bpf_module_mutex); 2469 2470 switch (op) { 2471 case MODULE_STATE_COMING: 2472 btm = kzalloc(sizeof(*btm), GFP_KERNEL); 2473 if (btm) { 2474 btm->module = module; 2475 list_add(&btm->list, &bpf_trace_modules); 2476 } else { 2477 ret = -ENOMEM; 2478 } 2479 break; 2480 case MODULE_STATE_GOING: 2481 list_for_each_entry_safe(btm, tmp, &bpf_trace_modules, list) { 2482 if (btm->module == module) { 2483 list_del(&btm->list); 2484 kfree(btm); 2485 break; 2486 } 2487 } 2488 break; 2489 } 2490 2491 mutex_unlock(&bpf_module_mutex); 2492 2493 out: 2494 return notifier_from_errno(ret); 2495 } 2496 2497 static struct notifier_block bpf_module_nb = { 2498 .notifier_call = bpf_event_notify, 2499 }; 2500 2501 static int __init bpf_event_init(void) 2502 { 2503 register_module_notifier(&bpf_module_nb); 2504 return 0; 2505 } 2506 2507 fs_initcall(bpf_event_init); 2508 #endif /* CONFIG_MODULES */ 2509 2510 #ifdef CONFIG_FPROBE 2511 struct bpf_kprobe_multi_link { 2512 struct bpf_link link; 2513 struct fprobe fp; 2514 unsigned long *addrs; 2515 u64 *cookies; 2516 u32 cnt; 2517 u32 mods_cnt; 2518 struct module **mods; 2519 u32 flags; 2520 }; 2521 2522 struct bpf_kprobe_multi_run_ctx { 2523 struct bpf_run_ctx run_ctx; 2524 struct bpf_kprobe_multi_link *link; 2525 unsigned long entry_ip; 2526 }; 2527 2528 struct user_syms { 2529 const char **syms; 2530 char *buf; 2531 }; 2532 2533 static int copy_user_syms(struct user_syms *us, unsigned long __user *usyms, u32 cnt) 2534 { 2535 unsigned long __user usymbol; 2536 const char **syms = NULL; 2537 char *buf = NULL, *p; 2538 int err = -ENOMEM; 2539 unsigned int i; 2540 2541 syms = kvmalloc_array(cnt, sizeof(*syms), GFP_KERNEL); 2542 if (!syms) 2543 goto error; 2544 2545 buf = kvmalloc_array(cnt, KSYM_NAME_LEN, GFP_KERNEL); 2546 if (!buf) 2547 goto error; 2548 2549 for (p = buf, i = 0; i < cnt; i++) { 2550 if (__get_user(usymbol, usyms + i)) { 2551 err = -EFAULT; 2552 goto error; 2553 } 2554 err = strncpy_from_user(p, (const char __user *) usymbol, KSYM_NAME_LEN); 2555 if (err == KSYM_NAME_LEN) 2556 err = -E2BIG; 2557 if (err < 0) 2558 goto error; 2559 syms[i] = p; 2560 p += err + 1; 2561 } 2562 2563 us->syms = syms; 2564 us->buf = buf; 2565 return 0; 2566 2567 error: 2568 if (err) { 2569 kvfree(syms); 2570 kvfree(buf); 2571 } 2572 return err; 2573 } 2574 2575 static void kprobe_multi_put_modules(struct module **mods, u32 cnt) 2576 { 2577 u32 i; 2578 2579 for (i = 0; i < cnt; i++) 2580 module_put(mods[i]); 2581 } 2582 2583 static void free_user_syms(struct user_syms *us) 2584 { 2585 kvfree(us->syms); 2586 kvfree(us->buf); 2587 } 2588 2589 static void bpf_kprobe_multi_link_release(struct bpf_link *link) 2590 { 2591 struct bpf_kprobe_multi_link *kmulti_link; 2592 2593 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); 2594 unregister_fprobe(&kmulti_link->fp); 2595 kprobe_multi_put_modules(kmulti_link->mods, kmulti_link->mods_cnt); 2596 } 2597 2598 static void bpf_kprobe_multi_link_dealloc(struct bpf_link *link) 2599 { 2600 struct bpf_kprobe_multi_link *kmulti_link; 2601 2602 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); 2603 kvfree(kmulti_link->addrs); 2604 kvfree(kmulti_link->cookies); 2605 kfree(kmulti_link->mods); 2606 kfree(kmulti_link); 2607 } 2608 2609 static int bpf_kprobe_multi_link_fill_link_info(const struct bpf_link *link, 2610 struct bpf_link_info *info) 2611 { 2612 u64 __user *uaddrs = u64_to_user_ptr(info->kprobe_multi.addrs); 2613 struct bpf_kprobe_multi_link *kmulti_link; 2614 u32 ucount = info->kprobe_multi.count; 2615 int err = 0, i; 2616 2617 if (!uaddrs ^ !ucount) 2618 return -EINVAL; 2619 2620 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); 2621 info->kprobe_multi.count = kmulti_link->cnt; 2622 info->kprobe_multi.flags = kmulti_link->flags; 2623 info->kprobe_multi.missed = kmulti_link->fp.nmissed; 2624 2625 if (!uaddrs) 2626 return 0; 2627 if (ucount < kmulti_link->cnt) 2628 err = -ENOSPC; 2629 else 2630 ucount = kmulti_link->cnt; 2631 2632 if (kallsyms_show_value(current_cred())) { 2633 if (copy_to_user(uaddrs, kmulti_link->addrs, ucount * sizeof(u64))) 2634 return -EFAULT; 2635 } else { 2636 for (i = 0; i < ucount; i++) { 2637 if (put_user(0, uaddrs + i)) 2638 return -EFAULT; 2639 } 2640 } 2641 return err; 2642 } 2643 2644 static const struct bpf_link_ops bpf_kprobe_multi_link_lops = { 2645 .release = bpf_kprobe_multi_link_release, 2646 .dealloc = bpf_kprobe_multi_link_dealloc, 2647 .fill_link_info = bpf_kprobe_multi_link_fill_link_info, 2648 }; 2649 2650 static void bpf_kprobe_multi_cookie_swap(void *a, void *b, int size, const void *priv) 2651 { 2652 const struct bpf_kprobe_multi_link *link = priv; 2653 unsigned long *addr_a = a, *addr_b = b; 2654 u64 *cookie_a, *cookie_b; 2655 2656 cookie_a = link->cookies + (addr_a - link->addrs); 2657 cookie_b = link->cookies + (addr_b - link->addrs); 2658 2659 /* swap addr_a/addr_b and cookie_a/cookie_b values */ 2660 swap(*addr_a, *addr_b); 2661 swap(*cookie_a, *cookie_b); 2662 } 2663 2664 static int bpf_kprobe_multi_addrs_cmp(const void *a, const void *b) 2665 { 2666 const unsigned long *addr_a = a, *addr_b = b; 2667 2668 if (*addr_a == *addr_b) 2669 return 0; 2670 return *addr_a < *addr_b ? -1 : 1; 2671 } 2672 2673 static int bpf_kprobe_multi_cookie_cmp(const void *a, const void *b, const void *priv) 2674 { 2675 return bpf_kprobe_multi_addrs_cmp(a, b); 2676 } 2677 2678 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx) 2679 { 2680 struct bpf_kprobe_multi_run_ctx *run_ctx; 2681 struct bpf_kprobe_multi_link *link; 2682 u64 *cookie, entry_ip; 2683 unsigned long *addr; 2684 2685 if (WARN_ON_ONCE(!ctx)) 2686 return 0; 2687 run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, run_ctx); 2688 link = run_ctx->link; 2689 if (!link->cookies) 2690 return 0; 2691 entry_ip = run_ctx->entry_ip; 2692 addr = bsearch(&entry_ip, link->addrs, link->cnt, sizeof(entry_ip), 2693 bpf_kprobe_multi_addrs_cmp); 2694 if (!addr) 2695 return 0; 2696 cookie = link->cookies + (addr - link->addrs); 2697 return *cookie; 2698 } 2699 2700 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 2701 { 2702 struct bpf_kprobe_multi_run_ctx *run_ctx; 2703 2704 run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, run_ctx); 2705 return run_ctx->entry_ip; 2706 } 2707 2708 static int 2709 kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link, 2710 unsigned long entry_ip, struct pt_regs *regs) 2711 { 2712 struct bpf_kprobe_multi_run_ctx run_ctx = { 2713 .link = link, 2714 .entry_ip = entry_ip, 2715 }; 2716 struct bpf_run_ctx *old_run_ctx; 2717 int err; 2718 2719 if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) { 2720 bpf_prog_inc_misses_counter(link->link.prog); 2721 err = 0; 2722 goto out; 2723 } 2724 2725 migrate_disable(); 2726 rcu_read_lock(); 2727 old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx); 2728 err = bpf_prog_run(link->link.prog, regs); 2729 bpf_reset_run_ctx(old_run_ctx); 2730 rcu_read_unlock(); 2731 migrate_enable(); 2732 2733 out: 2734 __this_cpu_dec(bpf_prog_active); 2735 return err; 2736 } 2737 2738 static int 2739 kprobe_multi_link_handler(struct fprobe *fp, unsigned long fentry_ip, 2740 unsigned long ret_ip, struct pt_regs *regs, 2741 void *data) 2742 { 2743 struct bpf_kprobe_multi_link *link; 2744 2745 link = container_of(fp, struct bpf_kprobe_multi_link, fp); 2746 kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), regs); 2747 return 0; 2748 } 2749 2750 static void 2751 kprobe_multi_link_exit_handler(struct fprobe *fp, unsigned long fentry_ip, 2752 unsigned long ret_ip, struct pt_regs *regs, 2753 void *data) 2754 { 2755 struct bpf_kprobe_multi_link *link; 2756 2757 link = container_of(fp, struct bpf_kprobe_multi_link, fp); 2758 kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), regs); 2759 } 2760 2761 static int symbols_cmp_r(const void *a, const void *b, const void *priv) 2762 { 2763 const char **str_a = (const char **) a; 2764 const char **str_b = (const char **) b; 2765 2766 return strcmp(*str_a, *str_b); 2767 } 2768 2769 struct multi_symbols_sort { 2770 const char **funcs; 2771 u64 *cookies; 2772 }; 2773 2774 static void symbols_swap_r(void *a, void *b, int size, const void *priv) 2775 { 2776 const struct multi_symbols_sort *data = priv; 2777 const char **name_a = a, **name_b = b; 2778 2779 swap(*name_a, *name_b); 2780 2781 /* If defined, swap also related cookies. */ 2782 if (data->cookies) { 2783 u64 *cookie_a, *cookie_b; 2784 2785 cookie_a = data->cookies + (name_a - data->funcs); 2786 cookie_b = data->cookies + (name_b - data->funcs); 2787 swap(*cookie_a, *cookie_b); 2788 } 2789 } 2790 2791 struct modules_array { 2792 struct module **mods; 2793 int mods_cnt; 2794 int mods_cap; 2795 }; 2796 2797 static int add_module(struct modules_array *arr, struct module *mod) 2798 { 2799 struct module **mods; 2800 2801 if (arr->mods_cnt == arr->mods_cap) { 2802 arr->mods_cap = max(16, arr->mods_cap * 3 / 2); 2803 mods = krealloc_array(arr->mods, arr->mods_cap, sizeof(*mods), GFP_KERNEL); 2804 if (!mods) 2805 return -ENOMEM; 2806 arr->mods = mods; 2807 } 2808 2809 arr->mods[arr->mods_cnt] = mod; 2810 arr->mods_cnt++; 2811 return 0; 2812 } 2813 2814 static bool has_module(struct modules_array *arr, struct module *mod) 2815 { 2816 int i; 2817 2818 for (i = arr->mods_cnt - 1; i >= 0; i--) { 2819 if (arr->mods[i] == mod) 2820 return true; 2821 } 2822 return false; 2823 } 2824 2825 static int get_modules_for_addrs(struct module ***mods, unsigned long *addrs, u32 addrs_cnt) 2826 { 2827 struct modules_array arr = {}; 2828 u32 i, err = 0; 2829 2830 for (i = 0; i < addrs_cnt; i++) { 2831 struct module *mod; 2832 2833 preempt_disable(); 2834 mod = __module_address(addrs[i]); 2835 /* Either no module or we it's already stored */ 2836 if (!mod || has_module(&arr, mod)) { 2837 preempt_enable(); 2838 continue; 2839 } 2840 if (!try_module_get(mod)) 2841 err = -EINVAL; 2842 preempt_enable(); 2843 if (err) 2844 break; 2845 err = add_module(&arr, mod); 2846 if (err) { 2847 module_put(mod); 2848 break; 2849 } 2850 } 2851 2852 /* We return either err < 0 in case of error, ... */ 2853 if (err) { 2854 kprobe_multi_put_modules(arr.mods, arr.mods_cnt); 2855 kfree(arr.mods); 2856 return err; 2857 } 2858 2859 /* or number of modules found if everything is ok. */ 2860 *mods = arr.mods; 2861 return arr.mods_cnt; 2862 } 2863 2864 static int addrs_check_error_injection_list(unsigned long *addrs, u32 cnt) 2865 { 2866 u32 i; 2867 2868 for (i = 0; i < cnt; i++) { 2869 if (!within_error_injection_list(addrs[i])) 2870 return -EINVAL; 2871 } 2872 return 0; 2873 } 2874 2875 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 2876 { 2877 struct bpf_kprobe_multi_link *link = NULL; 2878 struct bpf_link_primer link_primer; 2879 void __user *ucookies; 2880 unsigned long *addrs; 2881 u32 flags, cnt, size; 2882 void __user *uaddrs; 2883 u64 *cookies = NULL; 2884 void __user *usyms; 2885 int err; 2886 2887 /* no support for 32bit archs yet */ 2888 if (sizeof(u64) != sizeof(void *)) 2889 return -EOPNOTSUPP; 2890 2891 if (prog->expected_attach_type != BPF_TRACE_KPROBE_MULTI) 2892 return -EINVAL; 2893 2894 flags = attr->link_create.kprobe_multi.flags; 2895 if (flags & ~BPF_F_KPROBE_MULTI_RETURN) 2896 return -EINVAL; 2897 2898 uaddrs = u64_to_user_ptr(attr->link_create.kprobe_multi.addrs); 2899 usyms = u64_to_user_ptr(attr->link_create.kprobe_multi.syms); 2900 if (!!uaddrs == !!usyms) 2901 return -EINVAL; 2902 2903 cnt = attr->link_create.kprobe_multi.cnt; 2904 if (!cnt) 2905 return -EINVAL; 2906 2907 size = cnt * sizeof(*addrs); 2908 addrs = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL); 2909 if (!addrs) 2910 return -ENOMEM; 2911 2912 ucookies = u64_to_user_ptr(attr->link_create.kprobe_multi.cookies); 2913 if (ucookies) { 2914 cookies = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL); 2915 if (!cookies) { 2916 err = -ENOMEM; 2917 goto error; 2918 } 2919 if (copy_from_user(cookies, ucookies, size)) { 2920 err = -EFAULT; 2921 goto error; 2922 } 2923 } 2924 2925 if (uaddrs) { 2926 if (copy_from_user(addrs, uaddrs, size)) { 2927 err = -EFAULT; 2928 goto error; 2929 } 2930 } else { 2931 struct multi_symbols_sort data = { 2932 .cookies = cookies, 2933 }; 2934 struct user_syms us; 2935 2936 err = copy_user_syms(&us, usyms, cnt); 2937 if (err) 2938 goto error; 2939 2940 if (cookies) 2941 data.funcs = us.syms; 2942 2943 sort_r(us.syms, cnt, sizeof(*us.syms), symbols_cmp_r, 2944 symbols_swap_r, &data); 2945 2946 err = ftrace_lookup_symbols(us.syms, cnt, addrs); 2947 free_user_syms(&us); 2948 if (err) 2949 goto error; 2950 } 2951 2952 if (prog->kprobe_override && addrs_check_error_injection_list(addrs, cnt)) { 2953 err = -EINVAL; 2954 goto error; 2955 } 2956 2957 link = kzalloc(sizeof(*link), GFP_KERNEL); 2958 if (!link) { 2959 err = -ENOMEM; 2960 goto error; 2961 } 2962 2963 bpf_link_init(&link->link, BPF_LINK_TYPE_KPROBE_MULTI, 2964 &bpf_kprobe_multi_link_lops, prog); 2965 2966 err = bpf_link_prime(&link->link, &link_primer); 2967 if (err) 2968 goto error; 2969 2970 if (flags & BPF_F_KPROBE_MULTI_RETURN) 2971 link->fp.exit_handler = kprobe_multi_link_exit_handler; 2972 else 2973 link->fp.entry_handler = kprobe_multi_link_handler; 2974 2975 link->addrs = addrs; 2976 link->cookies = cookies; 2977 link->cnt = cnt; 2978 link->flags = flags; 2979 2980 if (cookies) { 2981 /* 2982 * Sorting addresses will trigger sorting cookies as well 2983 * (check bpf_kprobe_multi_cookie_swap). This way we can 2984 * find cookie based on the address in bpf_get_attach_cookie 2985 * helper. 2986 */ 2987 sort_r(addrs, cnt, sizeof(*addrs), 2988 bpf_kprobe_multi_cookie_cmp, 2989 bpf_kprobe_multi_cookie_swap, 2990 link); 2991 } 2992 2993 err = get_modules_for_addrs(&link->mods, addrs, cnt); 2994 if (err < 0) { 2995 bpf_link_cleanup(&link_primer); 2996 return err; 2997 } 2998 link->mods_cnt = err; 2999 3000 err = register_fprobe_ips(&link->fp, addrs, cnt); 3001 if (err) { 3002 kprobe_multi_put_modules(link->mods, link->mods_cnt); 3003 bpf_link_cleanup(&link_primer); 3004 return err; 3005 } 3006 3007 return bpf_link_settle(&link_primer); 3008 3009 error: 3010 kfree(link); 3011 kvfree(addrs); 3012 kvfree(cookies); 3013 return err; 3014 } 3015 #else /* !CONFIG_FPROBE */ 3016 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 3017 { 3018 return -EOPNOTSUPP; 3019 } 3020 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx) 3021 { 3022 return 0; 3023 } 3024 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 3025 { 3026 return 0; 3027 } 3028 #endif 3029 3030 #ifdef CONFIG_UPROBES 3031 struct bpf_uprobe_multi_link; 3032 3033 struct bpf_uprobe { 3034 struct bpf_uprobe_multi_link *link; 3035 loff_t offset; 3036 unsigned long ref_ctr_offset; 3037 u64 cookie; 3038 struct uprobe_consumer consumer; 3039 }; 3040 3041 struct bpf_uprobe_multi_link { 3042 struct path path; 3043 struct bpf_link link; 3044 u32 cnt; 3045 u32 flags; 3046 struct bpf_uprobe *uprobes; 3047 struct task_struct *task; 3048 }; 3049 3050 struct bpf_uprobe_multi_run_ctx { 3051 struct bpf_run_ctx run_ctx; 3052 unsigned long entry_ip; 3053 struct bpf_uprobe *uprobe; 3054 }; 3055 3056 static void bpf_uprobe_unregister(struct path *path, struct bpf_uprobe *uprobes, 3057 u32 cnt) 3058 { 3059 u32 i; 3060 3061 for (i = 0; i < cnt; i++) { 3062 uprobe_unregister(d_real_inode(path->dentry), uprobes[i].offset, 3063 &uprobes[i].consumer); 3064 } 3065 } 3066 3067 static void bpf_uprobe_multi_link_release(struct bpf_link *link) 3068 { 3069 struct bpf_uprobe_multi_link *umulti_link; 3070 3071 umulti_link = container_of(link, struct bpf_uprobe_multi_link, link); 3072 bpf_uprobe_unregister(&umulti_link->path, umulti_link->uprobes, umulti_link->cnt); 3073 } 3074 3075 static void bpf_uprobe_multi_link_dealloc(struct bpf_link *link) 3076 { 3077 struct bpf_uprobe_multi_link *umulti_link; 3078 3079 umulti_link = container_of(link, struct bpf_uprobe_multi_link, link); 3080 if (umulti_link->task) 3081 put_task_struct(umulti_link->task); 3082 path_put(&umulti_link->path); 3083 kvfree(umulti_link->uprobes); 3084 kfree(umulti_link); 3085 } 3086 3087 static int bpf_uprobe_multi_link_fill_link_info(const struct bpf_link *link, 3088 struct bpf_link_info *info) 3089 { 3090 u64 __user *uref_ctr_offsets = u64_to_user_ptr(info->uprobe_multi.ref_ctr_offsets); 3091 u64 __user *ucookies = u64_to_user_ptr(info->uprobe_multi.cookies); 3092 u64 __user *uoffsets = u64_to_user_ptr(info->uprobe_multi.offsets); 3093 u64 __user *upath = u64_to_user_ptr(info->uprobe_multi.path); 3094 u32 upath_size = info->uprobe_multi.path_size; 3095 struct bpf_uprobe_multi_link *umulti_link; 3096 u32 ucount = info->uprobe_multi.count; 3097 int err = 0, i; 3098 long left; 3099 3100 if (!upath ^ !upath_size) 3101 return -EINVAL; 3102 3103 if ((uoffsets || uref_ctr_offsets || ucookies) && !ucount) 3104 return -EINVAL; 3105 3106 umulti_link = container_of(link, struct bpf_uprobe_multi_link, link); 3107 info->uprobe_multi.count = umulti_link->cnt; 3108 info->uprobe_multi.flags = umulti_link->flags; 3109 info->uprobe_multi.pid = umulti_link->task ? 3110 task_pid_nr_ns(umulti_link->task, task_active_pid_ns(current)) : 0; 3111 3112 if (upath) { 3113 char *p, *buf; 3114 3115 upath_size = min_t(u32, upath_size, PATH_MAX); 3116 3117 buf = kmalloc(upath_size, GFP_KERNEL); 3118 if (!buf) 3119 return -ENOMEM; 3120 p = d_path(&umulti_link->path, buf, upath_size); 3121 if (IS_ERR(p)) { 3122 kfree(buf); 3123 return PTR_ERR(p); 3124 } 3125 upath_size = buf + upath_size - p; 3126 left = copy_to_user(upath, p, upath_size); 3127 kfree(buf); 3128 if (left) 3129 return -EFAULT; 3130 info->uprobe_multi.path_size = upath_size; 3131 } 3132 3133 if (!uoffsets && !ucookies && !uref_ctr_offsets) 3134 return 0; 3135 3136 if (ucount < umulti_link->cnt) 3137 err = -ENOSPC; 3138 else 3139 ucount = umulti_link->cnt; 3140 3141 for (i = 0; i < ucount; i++) { 3142 if (uoffsets && 3143 put_user(umulti_link->uprobes[i].offset, uoffsets + i)) 3144 return -EFAULT; 3145 if (uref_ctr_offsets && 3146 put_user(umulti_link->uprobes[i].ref_ctr_offset, uref_ctr_offsets + i)) 3147 return -EFAULT; 3148 if (ucookies && 3149 put_user(umulti_link->uprobes[i].cookie, ucookies + i)) 3150 return -EFAULT; 3151 } 3152 3153 return err; 3154 } 3155 3156 static const struct bpf_link_ops bpf_uprobe_multi_link_lops = { 3157 .release = bpf_uprobe_multi_link_release, 3158 .dealloc = bpf_uprobe_multi_link_dealloc, 3159 .fill_link_info = bpf_uprobe_multi_link_fill_link_info, 3160 }; 3161 3162 static int uprobe_prog_run(struct bpf_uprobe *uprobe, 3163 unsigned long entry_ip, 3164 struct pt_regs *regs) 3165 { 3166 struct bpf_uprobe_multi_link *link = uprobe->link; 3167 struct bpf_uprobe_multi_run_ctx run_ctx = { 3168 .entry_ip = entry_ip, 3169 .uprobe = uprobe, 3170 }; 3171 struct bpf_prog *prog = link->link.prog; 3172 bool sleepable = prog->aux->sleepable; 3173 struct bpf_run_ctx *old_run_ctx; 3174 int err = 0; 3175 3176 if (link->task && current != link->task) 3177 return 0; 3178 3179 if (sleepable) 3180 rcu_read_lock_trace(); 3181 else 3182 rcu_read_lock(); 3183 3184 migrate_disable(); 3185 3186 old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx); 3187 err = bpf_prog_run(link->link.prog, regs); 3188 bpf_reset_run_ctx(old_run_ctx); 3189 3190 migrate_enable(); 3191 3192 if (sleepable) 3193 rcu_read_unlock_trace(); 3194 else 3195 rcu_read_unlock(); 3196 return err; 3197 } 3198 3199 static bool 3200 uprobe_multi_link_filter(struct uprobe_consumer *con, enum uprobe_filter_ctx ctx, 3201 struct mm_struct *mm) 3202 { 3203 struct bpf_uprobe *uprobe; 3204 3205 uprobe = container_of(con, struct bpf_uprobe, consumer); 3206 return uprobe->link->task->mm == mm; 3207 } 3208 3209 static int 3210 uprobe_multi_link_handler(struct uprobe_consumer *con, struct pt_regs *regs) 3211 { 3212 struct bpf_uprobe *uprobe; 3213 3214 uprobe = container_of(con, struct bpf_uprobe, consumer); 3215 return uprobe_prog_run(uprobe, instruction_pointer(regs), regs); 3216 } 3217 3218 static int 3219 uprobe_multi_link_ret_handler(struct uprobe_consumer *con, unsigned long func, struct pt_regs *regs) 3220 { 3221 struct bpf_uprobe *uprobe; 3222 3223 uprobe = container_of(con, struct bpf_uprobe, consumer); 3224 return uprobe_prog_run(uprobe, func, regs); 3225 } 3226 3227 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 3228 { 3229 struct bpf_uprobe_multi_run_ctx *run_ctx; 3230 3231 run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx, run_ctx); 3232 return run_ctx->entry_ip; 3233 } 3234 3235 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx) 3236 { 3237 struct bpf_uprobe_multi_run_ctx *run_ctx; 3238 3239 run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx, run_ctx); 3240 return run_ctx->uprobe->cookie; 3241 } 3242 3243 int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 3244 { 3245 struct bpf_uprobe_multi_link *link = NULL; 3246 unsigned long __user *uref_ctr_offsets; 3247 struct bpf_link_primer link_primer; 3248 struct bpf_uprobe *uprobes = NULL; 3249 struct task_struct *task = NULL; 3250 unsigned long __user *uoffsets; 3251 u64 __user *ucookies; 3252 void __user *upath; 3253 u32 flags, cnt, i; 3254 struct path path; 3255 char *name; 3256 pid_t pid; 3257 int err; 3258 3259 /* no support for 32bit archs yet */ 3260 if (sizeof(u64) != sizeof(void *)) 3261 return -EOPNOTSUPP; 3262 3263 if (prog->expected_attach_type != BPF_TRACE_UPROBE_MULTI) 3264 return -EINVAL; 3265 3266 flags = attr->link_create.uprobe_multi.flags; 3267 if (flags & ~BPF_F_UPROBE_MULTI_RETURN) 3268 return -EINVAL; 3269 3270 /* 3271 * path, offsets and cnt are mandatory, 3272 * ref_ctr_offsets and cookies are optional 3273 */ 3274 upath = u64_to_user_ptr(attr->link_create.uprobe_multi.path); 3275 uoffsets = u64_to_user_ptr(attr->link_create.uprobe_multi.offsets); 3276 cnt = attr->link_create.uprobe_multi.cnt; 3277 3278 if (!upath || !uoffsets || !cnt) 3279 return -EINVAL; 3280 3281 uref_ctr_offsets = u64_to_user_ptr(attr->link_create.uprobe_multi.ref_ctr_offsets); 3282 ucookies = u64_to_user_ptr(attr->link_create.uprobe_multi.cookies); 3283 3284 name = strndup_user(upath, PATH_MAX); 3285 if (IS_ERR(name)) { 3286 err = PTR_ERR(name); 3287 return err; 3288 } 3289 3290 err = kern_path(name, LOOKUP_FOLLOW, &path); 3291 kfree(name); 3292 if (err) 3293 return err; 3294 3295 if (!d_is_reg(path.dentry)) { 3296 err = -EBADF; 3297 goto error_path_put; 3298 } 3299 3300 pid = attr->link_create.uprobe_multi.pid; 3301 if (pid) { 3302 rcu_read_lock(); 3303 task = get_pid_task(find_vpid(pid), PIDTYPE_PID); 3304 rcu_read_unlock(); 3305 if (!task) { 3306 err = -ESRCH; 3307 goto error_path_put; 3308 } 3309 } 3310 3311 err = -ENOMEM; 3312 3313 link = kzalloc(sizeof(*link), GFP_KERNEL); 3314 uprobes = kvcalloc(cnt, sizeof(*uprobes), GFP_KERNEL); 3315 3316 if (!uprobes || !link) 3317 goto error_free; 3318 3319 for (i = 0; i < cnt; i++) { 3320 if (ucookies && __get_user(uprobes[i].cookie, ucookies + i)) { 3321 err = -EFAULT; 3322 goto error_free; 3323 } 3324 if (uref_ctr_offsets && __get_user(uprobes[i].ref_ctr_offset, uref_ctr_offsets + i)) { 3325 err = -EFAULT; 3326 goto error_free; 3327 } 3328 if (__get_user(uprobes[i].offset, uoffsets + i)) { 3329 err = -EFAULT; 3330 goto error_free; 3331 } 3332 3333 uprobes[i].link = link; 3334 3335 if (flags & BPF_F_UPROBE_MULTI_RETURN) 3336 uprobes[i].consumer.ret_handler = uprobe_multi_link_ret_handler; 3337 else 3338 uprobes[i].consumer.handler = uprobe_multi_link_handler; 3339 3340 if (pid) 3341 uprobes[i].consumer.filter = uprobe_multi_link_filter; 3342 } 3343 3344 link->cnt = cnt; 3345 link->uprobes = uprobes; 3346 link->path = path; 3347 link->task = task; 3348 link->flags = flags; 3349 3350 bpf_link_init(&link->link, BPF_LINK_TYPE_UPROBE_MULTI, 3351 &bpf_uprobe_multi_link_lops, prog); 3352 3353 for (i = 0; i < cnt; i++) { 3354 err = uprobe_register_refctr(d_real_inode(link->path.dentry), 3355 uprobes[i].offset, 3356 uprobes[i].ref_ctr_offset, 3357 &uprobes[i].consumer); 3358 if (err) { 3359 bpf_uprobe_unregister(&path, uprobes, i); 3360 goto error_free; 3361 } 3362 } 3363 3364 err = bpf_link_prime(&link->link, &link_primer); 3365 if (err) 3366 goto error_free; 3367 3368 return bpf_link_settle(&link_primer); 3369 3370 error_free: 3371 kvfree(uprobes); 3372 kfree(link); 3373 if (task) 3374 put_task_struct(task); 3375 error_path_put: 3376 path_put(&path); 3377 return err; 3378 } 3379 #else /* !CONFIG_UPROBES */ 3380 int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 3381 { 3382 return -EOPNOTSUPP; 3383 } 3384 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx) 3385 { 3386 return 0; 3387 } 3388 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 3389 { 3390 return 0; 3391 } 3392 #endif /* CONFIG_UPROBES */ 3393