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 ret = 0; 121 goto out; 122 } 123 124 /* 125 * Instead of moving rcu_read_lock/rcu_dereference/rcu_read_unlock 126 * to all call sites, we did a bpf_prog_array_valid() there to check 127 * whether call->prog_array is empty or not, which is 128 * a heuristic to speed up execution. 129 * 130 * If bpf_prog_array_valid() fetched prog_array was 131 * non-NULL, we go into trace_call_bpf() and do the actual 132 * proper rcu_dereference() under RCU lock. 133 * If it turns out that prog_array is NULL then, we bail out. 134 * For the opposite, if the bpf_prog_array_valid() fetched pointer 135 * was NULL, you'll skip the prog_array with the risk of missing 136 * out of events when it was updated in between this and the 137 * rcu_dereference() which is accepted risk. 138 */ 139 rcu_read_lock(); 140 ret = bpf_prog_run_array(rcu_dereference(call->prog_array), 141 ctx, bpf_prog_run); 142 rcu_read_unlock(); 143 144 out: 145 __this_cpu_dec(bpf_prog_active); 146 147 return ret; 148 } 149 150 #ifdef CONFIG_BPF_KPROBE_OVERRIDE 151 BPF_CALL_2(bpf_override_return, struct pt_regs *, regs, unsigned long, rc) 152 { 153 regs_set_return_value(regs, rc); 154 override_function_with_return(regs); 155 return 0; 156 } 157 158 static const struct bpf_func_proto bpf_override_return_proto = { 159 .func = bpf_override_return, 160 .gpl_only = true, 161 .ret_type = RET_INTEGER, 162 .arg1_type = ARG_PTR_TO_CTX, 163 .arg2_type = ARG_ANYTHING, 164 }; 165 #endif 166 167 static __always_inline int 168 bpf_probe_read_user_common(void *dst, u32 size, const void __user *unsafe_ptr) 169 { 170 int ret; 171 172 ret = copy_from_user_nofault(dst, unsafe_ptr, size); 173 if (unlikely(ret < 0)) 174 memset(dst, 0, size); 175 return ret; 176 } 177 178 BPF_CALL_3(bpf_probe_read_user, void *, dst, u32, size, 179 const void __user *, unsafe_ptr) 180 { 181 return bpf_probe_read_user_common(dst, size, unsafe_ptr); 182 } 183 184 const struct bpf_func_proto bpf_probe_read_user_proto = { 185 .func = bpf_probe_read_user, 186 .gpl_only = true, 187 .ret_type = RET_INTEGER, 188 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 189 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 190 .arg3_type = ARG_ANYTHING, 191 }; 192 193 static __always_inline int 194 bpf_probe_read_user_str_common(void *dst, u32 size, 195 const void __user *unsafe_ptr) 196 { 197 int ret; 198 199 /* 200 * NB: We rely on strncpy_from_user() not copying junk past the NUL 201 * terminator into `dst`. 202 * 203 * strncpy_from_user() does long-sized strides in the fast path. If the 204 * strncpy does not mask out the bytes after the NUL in `unsafe_ptr`, 205 * then there could be junk after the NUL in `dst`. If user takes `dst` 206 * and keys a hash map with it, then semantically identical strings can 207 * occupy multiple entries in the map. 208 */ 209 ret = strncpy_from_user_nofault(dst, unsafe_ptr, size); 210 if (unlikely(ret < 0)) 211 memset(dst, 0, size); 212 return ret; 213 } 214 215 BPF_CALL_3(bpf_probe_read_user_str, void *, dst, u32, size, 216 const void __user *, unsafe_ptr) 217 { 218 return bpf_probe_read_user_str_common(dst, size, unsafe_ptr); 219 } 220 221 const struct bpf_func_proto bpf_probe_read_user_str_proto = { 222 .func = bpf_probe_read_user_str, 223 .gpl_only = true, 224 .ret_type = RET_INTEGER, 225 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 226 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 227 .arg3_type = ARG_ANYTHING, 228 }; 229 230 BPF_CALL_3(bpf_probe_read_kernel, void *, dst, u32, size, 231 const void *, unsafe_ptr) 232 { 233 return bpf_probe_read_kernel_common(dst, size, unsafe_ptr); 234 } 235 236 const struct bpf_func_proto bpf_probe_read_kernel_proto = { 237 .func = bpf_probe_read_kernel, 238 .gpl_only = true, 239 .ret_type = RET_INTEGER, 240 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 241 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 242 .arg3_type = ARG_ANYTHING, 243 }; 244 245 static __always_inline int 246 bpf_probe_read_kernel_str_common(void *dst, u32 size, const void *unsafe_ptr) 247 { 248 int ret; 249 250 /* 251 * The strncpy_from_kernel_nofault() call will likely not fill the 252 * entire buffer, but that's okay in this circumstance as we're probing 253 * arbitrary memory anyway similar to bpf_probe_read_*() and might 254 * as well probe the stack. Thus, memory is explicitly cleared 255 * only in error case, so that improper users ignoring return 256 * code altogether don't copy garbage; otherwise length of string 257 * is returned that can be used for bpf_perf_event_output() et al. 258 */ 259 ret = strncpy_from_kernel_nofault(dst, unsafe_ptr, size); 260 if (unlikely(ret < 0)) 261 memset(dst, 0, size); 262 return ret; 263 } 264 265 BPF_CALL_3(bpf_probe_read_kernel_str, void *, dst, u32, size, 266 const void *, unsafe_ptr) 267 { 268 return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr); 269 } 270 271 const struct bpf_func_proto bpf_probe_read_kernel_str_proto = { 272 .func = bpf_probe_read_kernel_str, 273 .gpl_only = true, 274 .ret_type = RET_INTEGER, 275 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 276 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 277 .arg3_type = ARG_ANYTHING, 278 }; 279 280 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 281 BPF_CALL_3(bpf_probe_read_compat, void *, dst, u32, size, 282 const void *, unsafe_ptr) 283 { 284 if ((unsigned long)unsafe_ptr < TASK_SIZE) { 285 return bpf_probe_read_user_common(dst, size, 286 (__force void __user *)unsafe_ptr); 287 } 288 return bpf_probe_read_kernel_common(dst, size, unsafe_ptr); 289 } 290 291 static const struct bpf_func_proto bpf_probe_read_compat_proto = { 292 .func = bpf_probe_read_compat, 293 .gpl_only = true, 294 .ret_type = RET_INTEGER, 295 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 296 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 297 .arg3_type = ARG_ANYTHING, 298 }; 299 300 BPF_CALL_3(bpf_probe_read_compat_str, void *, dst, u32, size, 301 const void *, unsafe_ptr) 302 { 303 if ((unsigned long)unsafe_ptr < TASK_SIZE) { 304 return bpf_probe_read_user_str_common(dst, size, 305 (__force void __user *)unsafe_ptr); 306 } 307 return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr); 308 } 309 310 static const struct bpf_func_proto bpf_probe_read_compat_str_proto = { 311 .func = bpf_probe_read_compat_str, 312 .gpl_only = true, 313 .ret_type = RET_INTEGER, 314 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 315 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 316 .arg3_type = ARG_ANYTHING, 317 }; 318 #endif /* CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE */ 319 320 BPF_CALL_3(bpf_probe_write_user, void __user *, unsafe_ptr, const void *, src, 321 u32, size) 322 { 323 /* 324 * Ensure we're in user context which is safe for the helper to 325 * run. This helper has no business in a kthread. 326 * 327 * access_ok() should prevent writing to non-user memory, but in 328 * some situations (nommu, temporary switch, etc) access_ok() does 329 * not provide enough validation, hence the check on KERNEL_DS. 330 * 331 * nmi_uaccess_okay() ensures the probe is not run in an interim 332 * state, when the task or mm are switched. This is specifically 333 * required to prevent the use of temporary mm. 334 */ 335 336 if (unlikely(in_interrupt() || 337 current->flags & (PF_KTHREAD | PF_EXITING))) 338 return -EPERM; 339 if (unlikely(!nmi_uaccess_okay())) 340 return -EPERM; 341 342 return copy_to_user_nofault(unsafe_ptr, src, size); 343 } 344 345 static const struct bpf_func_proto bpf_probe_write_user_proto = { 346 .func = bpf_probe_write_user, 347 .gpl_only = true, 348 .ret_type = RET_INTEGER, 349 .arg1_type = ARG_ANYTHING, 350 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 351 .arg3_type = ARG_CONST_SIZE, 352 }; 353 354 static const struct bpf_func_proto *bpf_get_probe_write_proto(void) 355 { 356 if (!capable(CAP_SYS_ADMIN)) 357 return NULL; 358 359 pr_warn_ratelimited("%s[%d] is installing a program with bpf_probe_write_user helper that may corrupt user memory!", 360 current->comm, task_pid_nr(current)); 361 362 return &bpf_probe_write_user_proto; 363 } 364 365 #define MAX_TRACE_PRINTK_VARARGS 3 366 #define BPF_TRACE_PRINTK_SIZE 1024 367 368 BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1, 369 u64, arg2, u64, arg3) 370 { 371 u64 args[MAX_TRACE_PRINTK_VARARGS] = { arg1, arg2, arg3 }; 372 struct bpf_bprintf_data data = { 373 .get_bin_args = true, 374 .get_buf = true, 375 }; 376 int ret; 377 378 ret = bpf_bprintf_prepare(fmt, fmt_size, args, 379 MAX_TRACE_PRINTK_VARARGS, &data); 380 if (ret < 0) 381 return ret; 382 383 ret = bstr_printf(data.buf, MAX_BPRINTF_BUF, fmt, data.bin_args); 384 385 trace_bpf_trace_printk(data.buf); 386 387 bpf_bprintf_cleanup(&data); 388 389 return ret; 390 } 391 392 static const struct bpf_func_proto bpf_trace_printk_proto = { 393 .func = bpf_trace_printk, 394 .gpl_only = true, 395 .ret_type = RET_INTEGER, 396 .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY, 397 .arg2_type = ARG_CONST_SIZE, 398 }; 399 400 static void __set_printk_clr_event(void) 401 { 402 /* 403 * This program might be calling bpf_trace_printk, 404 * so enable the associated bpf_trace/bpf_trace_printk event. 405 * Repeat this each time as it is possible a user has 406 * disabled bpf_trace_printk events. By loading a program 407 * calling bpf_trace_printk() however the user has expressed 408 * the intent to see such events. 409 */ 410 if (trace_set_clr_event("bpf_trace", "bpf_trace_printk", 1)) 411 pr_warn_ratelimited("could not enable bpf_trace_printk events"); 412 } 413 414 const struct bpf_func_proto *bpf_get_trace_printk_proto(void) 415 { 416 __set_printk_clr_event(); 417 return &bpf_trace_printk_proto; 418 } 419 420 BPF_CALL_4(bpf_trace_vprintk, char *, fmt, u32, fmt_size, const void *, args, 421 u32, data_len) 422 { 423 struct bpf_bprintf_data data = { 424 .get_bin_args = true, 425 .get_buf = true, 426 }; 427 int ret, num_args; 428 429 if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 || 430 (data_len && !args)) 431 return -EINVAL; 432 num_args = data_len / 8; 433 434 ret = bpf_bprintf_prepare(fmt, fmt_size, args, num_args, &data); 435 if (ret < 0) 436 return ret; 437 438 ret = bstr_printf(data.buf, MAX_BPRINTF_BUF, fmt, data.bin_args); 439 440 trace_bpf_trace_printk(data.buf); 441 442 bpf_bprintf_cleanup(&data); 443 444 return ret; 445 } 446 447 static const struct bpf_func_proto bpf_trace_vprintk_proto = { 448 .func = bpf_trace_vprintk, 449 .gpl_only = true, 450 .ret_type = RET_INTEGER, 451 .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY, 452 .arg2_type = ARG_CONST_SIZE, 453 .arg3_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY, 454 .arg4_type = ARG_CONST_SIZE_OR_ZERO, 455 }; 456 457 const struct bpf_func_proto *bpf_get_trace_vprintk_proto(void) 458 { 459 __set_printk_clr_event(); 460 return &bpf_trace_vprintk_proto; 461 } 462 463 BPF_CALL_5(bpf_seq_printf, struct seq_file *, m, char *, fmt, u32, fmt_size, 464 const void *, args, u32, data_len) 465 { 466 struct bpf_bprintf_data data = { 467 .get_bin_args = true, 468 }; 469 int err, num_args; 470 471 if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 || 472 (data_len && !args)) 473 return -EINVAL; 474 num_args = data_len / 8; 475 476 err = bpf_bprintf_prepare(fmt, fmt_size, args, num_args, &data); 477 if (err < 0) 478 return err; 479 480 seq_bprintf(m, fmt, data.bin_args); 481 482 bpf_bprintf_cleanup(&data); 483 484 return seq_has_overflowed(m) ? -EOVERFLOW : 0; 485 } 486 487 BTF_ID_LIST_SINGLE(btf_seq_file_ids, struct, seq_file) 488 489 static const struct bpf_func_proto bpf_seq_printf_proto = { 490 .func = bpf_seq_printf, 491 .gpl_only = true, 492 .ret_type = RET_INTEGER, 493 .arg1_type = ARG_PTR_TO_BTF_ID, 494 .arg1_btf_id = &btf_seq_file_ids[0], 495 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 496 .arg3_type = ARG_CONST_SIZE, 497 .arg4_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY, 498 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 499 }; 500 501 BPF_CALL_3(bpf_seq_write, struct seq_file *, m, const void *, data, u32, len) 502 { 503 return seq_write(m, data, len) ? -EOVERFLOW : 0; 504 } 505 506 static const struct bpf_func_proto bpf_seq_write_proto = { 507 .func = bpf_seq_write, 508 .gpl_only = true, 509 .ret_type = RET_INTEGER, 510 .arg1_type = ARG_PTR_TO_BTF_ID, 511 .arg1_btf_id = &btf_seq_file_ids[0], 512 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 513 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 514 }; 515 516 BPF_CALL_4(bpf_seq_printf_btf, struct seq_file *, m, struct btf_ptr *, ptr, 517 u32, btf_ptr_size, u64, flags) 518 { 519 const struct btf *btf; 520 s32 btf_id; 521 int ret; 522 523 ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id); 524 if (ret) 525 return ret; 526 527 return btf_type_seq_show_flags(btf, btf_id, ptr->ptr, m, flags); 528 } 529 530 static const struct bpf_func_proto bpf_seq_printf_btf_proto = { 531 .func = bpf_seq_printf_btf, 532 .gpl_only = true, 533 .ret_type = RET_INTEGER, 534 .arg1_type = ARG_PTR_TO_BTF_ID, 535 .arg1_btf_id = &btf_seq_file_ids[0], 536 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 537 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 538 .arg4_type = ARG_ANYTHING, 539 }; 540 541 static __always_inline int 542 get_map_perf_counter(struct bpf_map *map, u64 flags, 543 u64 *value, u64 *enabled, u64 *running) 544 { 545 struct bpf_array *array = container_of(map, struct bpf_array, map); 546 unsigned int cpu = smp_processor_id(); 547 u64 index = flags & BPF_F_INDEX_MASK; 548 struct bpf_event_entry *ee; 549 550 if (unlikely(flags & ~(BPF_F_INDEX_MASK))) 551 return -EINVAL; 552 if (index == BPF_F_CURRENT_CPU) 553 index = cpu; 554 if (unlikely(index >= array->map.max_entries)) 555 return -E2BIG; 556 557 ee = READ_ONCE(array->ptrs[index]); 558 if (!ee) 559 return -ENOENT; 560 561 return perf_event_read_local(ee->event, value, enabled, running); 562 } 563 564 BPF_CALL_2(bpf_perf_event_read, struct bpf_map *, map, u64, flags) 565 { 566 u64 value = 0; 567 int err; 568 569 err = get_map_perf_counter(map, flags, &value, NULL, NULL); 570 /* 571 * this api is ugly since we miss [-22..-2] range of valid 572 * counter values, but that's uapi 573 */ 574 if (err) 575 return err; 576 return value; 577 } 578 579 static const struct bpf_func_proto bpf_perf_event_read_proto = { 580 .func = bpf_perf_event_read, 581 .gpl_only = true, 582 .ret_type = RET_INTEGER, 583 .arg1_type = ARG_CONST_MAP_PTR, 584 .arg2_type = ARG_ANYTHING, 585 }; 586 587 BPF_CALL_4(bpf_perf_event_read_value, struct bpf_map *, map, u64, flags, 588 struct bpf_perf_event_value *, buf, u32, size) 589 { 590 int err = -EINVAL; 591 592 if (unlikely(size != sizeof(struct bpf_perf_event_value))) 593 goto clear; 594 err = get_map_perf_counter(map, flags, &buf->counter, &buf->enabled, 595 &buf->running); 596 if (unlikely(err)) 597 goto clear; 598 return 0; 599 clear: 600 memset(buf, 0, size); 601 return err; 602 } 603 604 static const struct bpf_func_proto bpf_perf_event_read_value_proto = { 605 .func = bpf_perf_event_read_value, 606 .gpl_only = true, 607 .ret_type = RET_INTEGER, 608 .arg1_type = ARG_CONST_MAP_PTR, 609 .arg2_type = ARG_ANYTHING, 610 .arg3_type = ARG_PTR_TO_UNINIT_MEM, 611 .arg4_type = ARG_CONST_SIZE, 612 }; 613 614 static __always_inline u64 615 __bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map, 616 u64 flags, struct perf_sample_data *sd) 617 { 618 struct bpf_array *array = container_of(map, struct bpf_array, map); 619 unsigned int cpu = smp_processor_id(); 620 u64 index = flags & BPF_F_INDEX_MASK; 621 struct bpf_event_entry *ee; 622 struct perf_event *event; 623 624 if (index == BPF_F_CURRENT_CPU) 625 index = cpu; 626 if (unlikely(index >= array->map.max_entries)) 627 return -E2BIG; 628 629 ee = READ_ONCE(array->ptrs[index]); 630 if (!ee) 631 return -ENOENT; 632 633 event = ee->event; 634 if (unlikely(event->attr.type != PERF_TYPE_SOFTWARE || 635 event->attr.config != PERF_COUNT_SW_BPF_OUTPUT)) 636 return -EINVAL; 637 638 if (unlikely(event->oncpu != cpu)) 639 return -EOPNOTSUPP; 640 641 return perf_event_output(event, sd, regs); 642 } 643 644 /* 645 * Support executing tracepoints in normal, irq, and nmi context that each call 646 * bpf_perf_event_output 647 */ 648 struct bpf_trace_sample_data { 649 struct perf_sample_data sds[3]; 650 }; 651 652 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_trace_sds); 653 static DEFINE_PER_CPU(int, bpf_trace_nest_level); 654 BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map, 655 u64, flags, void *, data, u64, size) 656 { 657 struct bpf_trace_sample_data *sds; 658 struct perf_raw_record raw = { 659 .frag = { 660 .size = size, 661 .data = data, 662 }, 663 }; 664 struct perf_sample_data *sd; 665 int nest_level, err; 666 667 preempt_disable(); 668 sds = this_cpu_ptr(&bpf_trace_sds); 669 nest_level = this_cpu_inc_return(bpf_trace_nest_level); 670 671 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(sds->sds))) { 672 err = -EBUSY; 673 goto out; 674 } 675 676 sd = &sds->sds[nest_level - 1]; 677 678 if (unlikely(flags & ~(BPF_F_INDEX_MASK))) { 679 err = -EINVAL; 680 goto out; 681 } 682 683 perf_sample_data_init(sd, 0, 0); 684 perf_sample_save_raw_data(sd, &raw); 685 686 err = __bpf_perf_event_output(regs, map, flags, sd); 687 out: 688 this_cpu_dec(bpf_trace_nest_level); 689 preempt_enable(); 690 return err; 691 } 692 693 static const struct bpf_func_proto bpf_perf_event_output_proto = { 694 .func = bpf_perf_event_output, 695 .gpl_only = true, 696 .ret_type = RET_INTEGER, 697 .arg1_type = ARG_PTR_TO_CTX, 698 .arg2_type = ARG_CONST_MAP_PTR, 699 .arg3_type = ARG_ANYTHING, 700 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, 701 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 702 }; 703 704 static DEFINE_PER_CPU(int, bpf_event_output_nest_level); 705 struct bpf_nested_pt_regs { 706 struct pt_regs regs[3]; 707 }; 708 static DEFINE_PER_CPU(struct bpf_nested_pt_regs, bpf_pt_regs); 709 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_misc_sds); 710 711 u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size, 712 void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy) 713 { 714 struct perf_raw_frag frag = { 715 .copy = ctx_copy, 716 .size = ctx_size, 717 .data = ctx, 718 }; 719 struct perf_raw_record raw = { 720 .frag = { 721 { 722 .next = ctx_size ? &frag : NULL, 723 }, 724 .size = meta_size, 725 .data = meta, 726 }, 727 }; 728 struct perf_sample_data *sd; 729 struct pt_regs *regs; 730 int nest_level; 731 u64 ret; 732 733 preempt_disable(); 734 nest_level = this_cpu_inc_return(bpf_event_output_nest_level); 735 736 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(bpf_misc_sds.sds))) { 737 ret = -EBUSY; 738 goto out; 739 } 740 sd = this_cpu_ptr(&bpf_misc_sds.sds[nest_level - 1]); 741 regs = this_cpu_ptr(&bpf_pt_regs.regs[nest_level - 1]); 742 743 perf_fetch_caller_regs(regs); 744 perf_sample_data_init(sd, 0, 0); 745 perf_sample_save_raw_data(sd, &raw); 746 747 ret = __bpf_perf_event_output(regs, map, flags, sd); 748 out: 749 this_cpu_dec(bpf_event_output_nest_level); 750 preempt_enable(); 751 return ret; 752 } 753 754 BPF_CALL_0(bpf_get_current_task) 755 { 756 return (long) current; 757 } 758 759 const struct bpf_func_proto bpf_get_current_task_proto = { 760 .func = bpf_get_current_task, 761 .gpl_only = true, 762 .ret_type = RET_INTEGER, 763 }; 764 765 BPF_CALL_0(bpf_get_current_task_btf) 766 { 767 return (unsigned long) current; 768 } 769 770 const struct bpf_func_proto bpf_get_current_task_btf_proto = { 771 .func = bpf_get_current_task_btf, 772 .gpl_only = true, 773 .ret_type = RET_PTR_TO_BTF_ID_TRUSTED, 774 .ret_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK], 775 }; 776 777 BPF_CALL_1(bpf_task_pt_regs, struct task_struct *, task) 778 { 779 return (unsigned long) task_pt_regs(task); 780 } 781 782 BTF_ID_LIST(bpf_task_pt_regs_ids) 783 BTF_ID(struct, pt_regs) 784 785 const struct bpf_func_proto bpf_task_pt_regs_proto = { 786 .func = bpf_task_pt_regs, 787 .gpl_only = true, 788 .arg1_type = ARG_PTR_TO_BTF_ID, 789 .arg1_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK], 790 .ret_type = RET_PTR_TO_BTF_ID, 791 .ret_btf_id = &bpf_task_pt_regs_ids[0], 792 }; 793 794 BPF_CALL_2(bpf_current_task_under_cgroup, struct bpf_map *, map, u32, idx) 795 { 796 struct bpf_array *array = container_of(map, struct bpf_array, map); 797 struct cgroup *cgrp; 798 799 if (unlikely(idx >= array->map.max_entries)) 800 return -E2BIG; 801 802 cgrp = READ_ONCE(array->ptrs[idx]); 803 if (unlikely(!cgrp)) 804 return -EAGAIN; 805 806 return task_under_cgroup_hierarchy(current, cgrp); 807 } 808 809 static const struct bpf_func_proto bpf_current_task_under_cgroup_proto = { 810 .func = bpf_current_task_under_cgroup, 811 .gpl_only = false, 812 .ret_type = RET_INTEGER, 813 .arg1_type = ARG_CONST_MAP_PTR, 814 .arg2_type = ARG_ANYTHING, 815 }; 816 817 struct send_signal_irq_work { 818 struct irq_work irq_work; 819 struct task_struct *task; 820 u32 sig; 821 enum pid_type type; 822 }; 823 824 static DEFINE_PER_CPU(struct send_signal_irq_work, send_signal_work); 825 826 static void do_bpf_send_signal(struct irq_work *entry) 827 { 828 struct send_signal_irq_work *work; 829 830 work = container_of(entry, struct send_signal_irq_work, irq_work); 831 group_send_sig_info(work->sig, SEND_SIG_PRIV, work->task, work->type); 832 put_task_struct(work->task); 833 } 834 835 static int bpf_send_signal_common(u32 sig, enum pid_type type) 836 { 837 struct send_signal_irq_work *work = NULL; 838 839 /* Similar to bpf_probe_write_user, task needs to be 840 * in a sound condition and kernel memory access be 841 * permitted in order to send signal to the current 842 * task. 843 */ 844 if (unlikely(current->flags & (PF_KTHREAD | PF_EXITING))) 845 return -EPERM; 846 if (unlikely(!nmi_uaccess_okay())) 847 return -EPERM; 848 /* Task should not be pid=1 to avoid kernel panic. */ 849 if (unlikely(is_global_init(current))) 850 return -EPERM; 851 852 if (irqs_disabled()) { 853 /* Do an early check on signal validity. Otherwise, 854 * the error is lost in deferred irq_work. 855 */ 856 if (unlikely(!valid_signal(sig))) 857 return -EINVAL; 858 859 work = this_cpu_ptr(&send_signal_work); 860 if (irq_work_is_busy(&work->irq_work)) 861 return -EBUSY; 862 863 /* Add the current task, which is the target of sending signal, 864 * to the irq_work. The current task may change when queued 865 * irq works get executed. 866 */ 867 work->task = get_task_struct(current); 868 work->sig = sig; 869 work->type = type; 870 irq_work_queue(&work->irq_work); 871 return 0; 872 } 873 874 return group_send_sig_info(sig, SEND_SIG_PRIV, current, type); 875 } 876 877 BPF_CALL_1(bpf_send_signal, u32, sig) 878 { 879 return bpf_send_signal_common(sig, PIDTYPE_TGID); 880 } 881 882 static const struct bpf_func_proto bpf_send_signal_proto = { 883 .func = bpf_send_signal, 884 .gpl_only = false, 885 .ret_type = RET_INTEGER, 886 .arg1_type = ARG_ANYTHING, 887 }; 888 889 BPF_CALL_1(bpf_send_signal_thread, u32, sig) 890 { 891 return bpf_send_signal_common(sig, PIDTYPE_PID); 892 } 893 894 static const struct bpf_func_proto bpf_send_signal_thread_proto = { 895 .func = bpf_send_signal_thread, 896 .gpl_only = false, 897 .ret_type = RET_INTEGER, 898 .arg1_type = ARG_ANYTHING, 899 }; 900 901 BPF_CALL_3(bpf_d_path, struct path *, path, char *, buf, u32, sz) 902 { 903 struct path copy; 904 long len; 905 char *p; 906 907 if (!sz) 908 return 0; 909 910 /* 911 * The path pointer is verified as trusted and safe to use, 912 * but let's double check it's valid anyway to workaround 913 * potentially broken verifier. 914 */ 915 len = copy_from_kernel_nofault(©, path, sizeof(*path)); 916 if (len < 0) 917 return len; 918 919 p = d_path(©, buf, sz); 920 if (IS_ERR(p)) { 921 len = PTR_ERR(p); 922 } else { 923 len = buf + sz - p; 924 memmove(buf, p, len); 925 } 926 927 return len; 928 } 929 930 BTF_SET_START(btf_allowlist_d_path) 931 #ifdef CONFIG_SECURITY 932 BTF_ID(func, security_file_permission) 933 BTF_ID(func, security_inode_getattr) 934 BTF_ID(func, security_file_open) 935 #endif 936 #ifdef CONFIG_SECURITY_PATH 937 BTF_ID(func, security_path_truncate) 938 #endif 939 BTF_ID(func, vfs_truncate) 940 BTF_ID(func, vfs_fallocate) 941 BTF_ID(func, dentry_open) 942 BTF_ID(func, vfs_getattr) 943 BTF_ID(func, filp_close) 944 BTF_SET_END(btf_allowlist_d_path) 945 946 static bool bpf_d_path_allowed(const struct bpf_prog *prog) 947 { 948 if (prog->type == BPF_PROG_TYPE_TRACING && 949 prog->expected_attach_type == BPF_TRACE_ITER) 950 return true; 951 952 if (prog->type == BPF_PROG_TYPE_LSM) 953 return bpf_lsm_is_sleepable_hook(prog->aux->attach_btf_id); 954 955 return btf_id_set_contains(&btf_allowlist_d_path, 956 prog->aux->attach_btf_id); 957 } 958 959 BTF_ID_LIST_SINGLE(bpf_d_path_btf_ids, struct, path) 960 961 static const struct bpf_func_proto bpf_d_path_proto = { 962 .func = bpf_d_path, 963 .gpl_only = false, 964 .ret_type = RET_INTEGER, 965 .arg1_type = ARG_PTR_TO_BTF_ID, 966 .arg1_btf_id = &bpf_d_path_btf_ids[0], 967 .arg2_type = ARG_PTR_TO_MEM, 968 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 969 .allowed = bpf_d_path_allowed, 970 }; 971 972 #define BTF_F_ALL (BTF_F_COMPACT | BTF_F_NONAME | \ 973 BTF_F_PTR_RAW | BTF_F_ZERO) 974 975 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size, 976 u64 flags, const struct btf **btf, 977 s32 *btf_id) 978 { 979 const struct btf_type *t; 980 981 if (unlikely(flags & ~(BTF_F_ALL))) 982 return -EINVAL; 983 984 if (btf_ptr_size != sizeof(struct btf_ptr)) 985 return -EINVAL; 986 987 *btf = bpf_get_btf_vmlinux(); 988 989 if (IS_ERR_OR_NULL(*btf)) 990 return IS_ERR(*btf) ? PTR_ERR(*btf) : -EINVAL; 991 992 if (ptr->type_id > 0) 993 *btf_id = ptr->type_id; 994 else 995 return -EINVAL; 996 997 if (*btf_id > 0) 998 t = btf_type_by_id(*btf, *btf_id); 999 if (*btf_id <= 0 || !t) 1000 return -ENOENT; 1001 1002 return 0; 1003 } 1004 1005 BPF_CALL_5(bpf_snprintf_btf, char *, str, u32, str_size, struct btf_ptr *, ptr, 1006 u32, btf_ptr_size, u64, flags) 1007 { 1008 const struct btf *btf; 1009 s32 btf_id; 1010 int ret; 1011 1012 ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id); 1013 if (ret) 1014 return ret; 1015 1016 return btf_type_snprintf_show(btf, btf_id, ptr->ptr, str, str_size, 1017 flags); 1018 } 1019 1020 const struct bpf_func_proto bpf_snprintf_btf_proto = { 1021 .func = bpf_snprintf_btf, 1022 .gpl_only = false, 1023 .ret_type = RET_INTEGER, 1024 .arg1_type = ARG_PTR_TO_MEM, 1025 .arg2_type = ARG_CONST_SIZE, 1026 .arg3_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1027 .arg4_type = ARG_CONST_SIZE, 1028 .arg5_type = ARG_ANYTHING, 1029 }; 1030 1031 BPF_CALL_1(bpf_get_func_ip_tracing, void *, ctx) 1032 { 1033 /* This helper call is inlined by verifier. */ 1034 return ((u64 *)ctx)[-2]; 1035 } 1036 1037 static const struct bpf_func_proto bpf_get_func_ip_proto_tracing = { 1038 .func = bpf_get_func_ip_tracing, 1039 .gpl_only = true, 1040 .ret_type = RET_INTEGER, 1041 .arg1_type = ARG_PTR_TO_CTX, 1042 }; 1043 1044 #ifdef CONFIG_X86_KERNEL_IBT 1045 static unsigned long get_entry_ip(unsigned long fentry_ip) 1046 { 1047 u32 instr; 1048 1049 /* Being extra safe in here in case entry ip is on the page-edge. */ 1050 if (get_kernel_nofault(instr, (u32 *) fentry_ip - 1)) 1051 return fentry_ip; 1052 if (is_endbr(instr)) 1053 fentry_ip -= ENDBR_INSN_SIZE; 1054 return fentry_ip; 1055 } 1056 #else 1057 #define get_entry_ip(fentry_ip) fentry_ip 1058 #endif 1059 1060 BPF_CALL_1(bpf_get_func_ip_kprobe, struct pt_regs *, regs) 1061 { 1062 struct bpf_trace_run_ctx *run_ctx __maybe_unused; 1063 struct kprobe *kp; 1064 1065 #ifdef CONFIG_UPROBES 1066 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); 1067 if (run_ctx->is_uprobe) 1068 return ((struct uprobe_dispatch_data *)current->utask->vaddr)->bp_addr; 1069 #endif 1070 1071 kp = kprobe_running(); 1072 1073 if (!kp || !(kp->flags & KPROBE_FLAG_ON_FUNC_ENTRY)) 1074 return 0; 1075 1076 return get_entry_ip((uintptr_t)kp->addr); 1077 } 1078 1079 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe = { 1080 .func = bpf_get_func_ip_kprobe, 1081 .gpl_only = true, 1082 .ret_type = RET_INTEGER, 1083 .arg1_type = ARG_PTR_TO_CTX, 1084 }; 1085 1086 BPF_CALL_1(bpf_get_func_ip_kprobe_multi, struct pt_regs *, regs) 1087 { 1088 return bpf_kprobe_multi_entry_ip(current->bpf_ctx); 1089 } 1090 1091 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe_multi = { 1092 .func = bpf_get_func_ip_kprobe_multi, 1093 .gpl_only = false, 1094 .ret_type = RET_INTEGER, 1095 .arg1_type = ARG_PTR_TO_CTX, 1096 }; 1097 1098 BPF_CALL_1(bpf_get_attach_cookie_kprobe_multi, struct pt_regs *, regs) 1099 { 1100 return bpf_kprobe_multi_cookie(current->bpf_ctx); 1101 } 1102 1103 static const struct bpf_func_proto bpf_get_attach_cookie_proto_kmulti = { 1104 .func = bpf_get_attach_cookie_kprobe_multi, 1105 .gpl_only = false, 1106 .ret_type = RET_INTEGER, 1107 .arg1_type = ARG_PTR_TO_CTX, 1108 }; 1109 1110 BPF_CALL_1(bpf_get_func_ip_uprobe_multi, struct pt_regs *, regs) 1111 { 1112 return bpf_uprobe_multi_entry_ip(current->bpf_ctx); 1113 } 1114 1115 static const struct bpf_func_proto bpf_get_func_ip_proto_uprobe_multi = { 1116 .func = bpf_get_func_ip_uprobe_multi, 1117 .gpl_only = false, 1118 .ret_type = RET_INTEGER, 1119 .arg1_type = ARG_PTR_TO_CTX, 1120 }; 1121 1122 BPF_CALL_1(bpf_get_attach_cookie_uprobe_multi, struct pt_regs *, regs) 1123 { 1124 return bpf_uprobe_multi_cookie(current->bpf_ctx); 1125 } 1126 1127 static const struct bpf_func_proto bpf_get_attach_cookie_proto_umulti = { 1128 .func = bpf_get_attach_cookie_uprobe_multi, 1129 .gpl_only = false, 1130 .ret_type = RET_INTEGER, 1131 .arg1_type = ARG_PTR_TO_CTX, 1132 }; 1133 1134 BPF_CALL_1(bpf_get_attach_cookie_trace, void *, ctx) 1135 { 1136 struct bpf_trace_run_ctx *run_ctx; 1137 1138 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); 1139 return run_ctx->bpf_cookie; 1140 } 1141 1142 static const struct bpf_func_proto bpf_get_attach_cookie_proto_trace = { 1143 .func = bpf_get_attach_cookie_trace, 1144 .gpl_only = false, 1145 .ret_type = RET_INTEGER, 1146 .arg1_type = ARG_PTR_TO_CTX, 1147 }; 1148 1149 BPF_CALL_1(bpf_get_attach_cookie_pe, struct bpf_perf_event_data_kern *, ctx) 1150 { 1151 return ctx->event->bpf_cookie; 1152 } 1153 1154 static const struct bpf_func_proto bpf_get_attach_cookie_proto_pe = { 1155 .func = bpf_get_attach_cookie_pe, 1156 .gpl_only = false, 1157 .ret_type = RET_INTEGER, 1158 .arg1_type = ARG_PTR_TO_CTX, 1159 }; 1160 1161 BPF_CALL_1(bpf_get_attach_cookie_tracing, void *, ctx) 1162 { 1163 struct bpf_trace_run_ctx *run_ctx; 1164 1165 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); 1166 return run_ctx->bpf_cookie; 1167 } 1168 1169 static const struct bpf_func_proto bpf_get_attach_cookie_proto_tracing = { 1170 .func = bpf_get_attach_cookie_tracing, 1171 .gpl_only = false, 1172 .ret_type = RET_INTEGER, 1173 .arg1_type = ARG_PTR_TO_CTX, 1174 }; 1175 1176 BPF_CALL_3(bpf_get_branch_snapshot, void *, buf, u32, size, u64, flags) 1177 { 1178 #ifndef CONFIG_X86 1179 return -ENOENT; 1180 #else 1181 static const u32 br_entry_size = sizeof(struct perf_branch_entry); 1182 u32 entry_cnt = size / br_entry_size; 1183 1184 entry_cnt = static_call(perf_snapshot_branch_stack)(buf, entry_cnt); 1185 1186 if (unlikely(flags)) 1187 return -EINVAL; 1188 1189 if (!entry_cnt) 1190 return -ENOENT; 1191 1192 return entry_cnt * br_entry_size; 1193 #endif 1194 } 1195 1196 static const struct bpf_func_proto bpf_get_branch_snapshot_proto = { 1197 .func = bpf_get_branch_snapshot, 1198 .gpl_only = true, 1199 .ret_type = RET_INTEGER, 1200 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 1201 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 1202 }; 1203 1204 BPF_CALL_3(get_func_arg, void *, ctx, u32, n, u64 *, value) 1205 { 1206 /* This helper call is inlined by verifier. */ 1207 u64 nr_args = ((u64 *)ctx)[-1]; 1208 1209 if ((u64) n >= nr_args) 1210 return -EINVAL; 1211 *value = ((u64 *)ctx)[n]; 1212 return 0; 1213 } 1214 1215 static const struct bpf_func_proto bpf_get_func_arg_proto = { 1216 .func = get_func_arg, 1217 .ret_type = RET_INTEGER, 1218 .arg1_type = ARG_PTR_TO_CTX, 1219 .arg2_type = ARG_ANYTHING, 1220 .arg3_type = ARG_PTR_TO_LONG, 1221 }; 1222 1223 BPF_CALL_2(get_func_ret, void *, ctx, u64 *, value) 1224 { 1225 /* This helper call is inlined by verifier. */ 1226 u64 nr_args = ((u64 *)ctx)[-1]; 1227 1228 *value = ((u64 *)ctx)[nr_args]; 1229 return 0; 1230 } 1231 1232 static const struct bpf_func_proto bpf_get_func_ret_proto = { 1233 .func = get_func_ret, 1234 .ret_type = RET_INTEGER, 1235 .arg1_type = ARG_PTR_TO_CTX, 1236 .arg2_type = ARG_PTR_TO_LONG, 1237 }; 1238 1239 BPF_CALL_1(get_func_arg_cnt, void *, ctx) 1240 { 1241 /* This helper call is inlined by verifier. */ 1242 return ((u64 *)ctx)[-1]; 1243 } 1244 1245 static const struct bpf_func_proto bpf_get_func_arg_cnt_proto = { 1246 .func = get_func_arg_cnt, 1247 .ret_type = RET_INTEGER, 1248 .arg1_type = ARG_PTR_TO_CTX, 1249 }; 1250 1251 #ifdef CONFIG_KEYS 1252 __diag_push(); 1253 __diag_ignore_all("-Wmissing-prototypes", 1254 "kfuncs which will be used in BPF programs"); 1255 1256 /** 1257 * bpf_lookup_user_key - lookup a key by its serial 1258 * @serial: key handle serial number 1259 * @flags: lookup-specific flags 1260 * 1261 * Search a key with a given *serial* and the provided *flags*. 1262 * If found, increment the reference count of the key by one, and 1263 * return it in the bpf_key structure. 1264 * 1265 * The bpf_key structure must be passed to bpf_key_put() when done 1266 * with it, so that the key reference count is decremented and the 1267 * bpf_key structure is freed. 1268 * 1269 * Permission checks are deferred to the time the key is used by 1270 * one of the available key-specific kfuncs. 1271 * 1272 * Set *flags* with KEY_LOOKUP_CREATE, to attempt creating a requested 1273 * special keyring (e.g. session keyring), if it doesn't yet exist. 1274 * Set *flags* with KEY_LOOKUP_PARTIAL, to lookup a key without waiting 1275 * for the key construction, and to retrieve uninstantiated keys (keys 1276 * without data attached to them). 1277 * 1278 * Return: a bpf_key pointer with a valid key pointer if the key is found, a 1279 * NULL pointer otherwise. 1280 */ 1281 __bpf_kfunc struct bpf_key *bpf_lookup_user_key(u32 serial, u64 flags) 1282 { 1283 key_ref_t key_ref; 1284 struct bpf_key *bkey; 1285 1286 if (flags & ~KEY_LOOKUP_ALL) 1287 return NULL; 1288 1289 /* 1290 * Permission check is deferred until the key is used, as the 1291 * intent of the caller is unknown here. 1292 */ 1293 key_ref = lookup_user_key(serial, flags, KEY_DEFER_PERM_CHECK); 1294 if (IS_ERR(key_ref)) 1295 return NULL; 1296 1297 bkey = kmalloc(sizeof(*bkey), GFP_KERNEL); 1298 if (!bkey) { 1299 key_put(key_ref_to_ptr(key_ref)); 1300 return NULL; 1301 } 1302 1303 bkey->key = key_ref_to_ptr(key_ref); 1304 bkey->has_ref = true; 1305 1306 return bkey; 1307 } 1308 1309 /** 1310 * bpf_lookup_system_key - lookup a key by a system-defined ID 1311 * @id: key ID 1312 * 1313 * Obtain a bpf_key structure with a key pointer set to the passed key ID. 1314 * The key pointer is marked as invalid, to prevent bpf_key_put() from 1315 * attempting to decrement the key reference count on that pointer. The key 1316 * pointer set in such way is currently understood only by 1317 * verify_pkcs7_signature(). 1318 * 1319 * Set *id* to one of the values defined in include/linux/verification.h: 1320 * 0 for the primary keyring (immutable keyring of system keys); 1321 * VERIFY_USE_SECONDARY_KEYRING for both the primary and secondary keyring 1322 * (where keys can be added only if they are vouched for by existing keys 1323 * in those keyrings); VERIFY_USE_PLATFORM_KEYRING for the platform 1324 * keyring (primarily used by the integrity subsystem to verify a kexec'ed 1325 * kerned image and, possibly, the initramfs signature). 1326 * 1327 * Return: a bpf_key pointer with an invalid key pointer set from the 1328 * pre-determined ID on success, a NULL pointer otherwise 1329 */ 1330 __bpf_kfunc struct bpf_key *bpf_lookup_system_key(u64 id) 1331 { 1332 struct bpf_key *bkey; 1333 1334 if (system_keyring_id_check(id) < 0) 1335 return NULL; 1336 1337 bkey = kmalloc(sizeof(*bkey), GFP_ATOMIC); 1338 if (!bkey) 1339 return NULL; 1340 1341 bkey->key = (struct key *)(unsigned long)id; 1342 bkey->has_ref = false; 1343 1344 return bkey; 1345 } 1346 1347 /** 1348 * bpf_key_put - decrement key reference count if key is valid and free bpf_key 1349 * @bkey: bpf_key structure 1350 * 1351 * Decrement the reference count of the key inside *bkey*, if the pointer 1352 * is valid, and free *bkey*. 1353 */ 1354 __bpf_kfunc void bpf_key_put(struct bpf_key *bkey) 1355 { 1356 if (bkey->has_ref) 1357 key_put(bkey->key); 1358 1359 kfree(bkey); 1360 } 1361 1362 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION 1363 /** 1364 * bpf_verify_pkcs7_signature - verify a PKCS#7 signature 1365 * @data_ptr: data to verify 1366 * @sig_ptr: signature of the data 1367 * @trusted_keyring: keyring with keys trusted for signature verification 1368 * 1369 * Verify the PKCS#7 signature *sig_ptr* against the supplied *data_ptr* 1370 * with keys in a keyring referenced by *trusted_keyring*. 1371 * 1372 * Return: 0 on success, a negative value on error. 1373 */ 1374 __bpf_kfunc int bpf_verify_pkcs7_signature(struct bpf_dynptr_kern *data_ptr, 1375 struct bpf_dynptr_kern *sig_ptr, 1376 struct bpf_key *trusted_keyring) 1377 { 1378 int ret; 1379 1380 if (trusted_keyring->has_ref) { 1381 /* 1382 * Do the permission check deferred in bpf_lookup_user_key(). 1383 * See bpf_lookup_user_key() for more details. 1384 * 1385 * A call to key_task_permission() here would be redundant, as 1386 * it is already done by keyring_search() called by 1387 * find_asymmetric_key(). 1388 */ 1389 ret = key_validate(trusted_keyring->key); 1390 if (ret < 0) 1391 return ret; 1392 } 1393 1394 return verify_pkcs7_signature(data_ptr->data, 1395 __bpf_dynptr_size(data_ptr), 1396 sig_ptr->data, 1397 __bpf_dynptr_size(sig_ptr), 1398 trusted_keyring->key, 1399 VERIFYING_UNSPECIFIED_SIGNATURE, NULL, 1400 NULL); 1401 } 1402 #endif /* CONFIG_SYSTEM_DATA_VERIFICATION */ 1403 1404 __diag_pop(); 1405 1406 BTF_SET8_START(key_sig_kfunc_set) 1407 BTF_ID_FLAGS(func, bpf_lookup_user_key, KF_ACQUIRE | KF_RET_NULL | KF_SLEEPABLE) 1408 BTF_ID_FLAGS(func, bpf_lookup_system_key, KF_ACQUIRE | KF_RET_NULL) 1409 BTF_ID_FLAGS(func, bpf_key_put, KF_RELEASE) 1410 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION 1411 BTF_ID_FLAGS(func, bpf_verify_pkcs7_signature, KF_SLEEPABLE) 1412 #endif 1413 BTF_SET8_END(key_sig_kfunc_set) 1414 1415 static const struct btf_kfunc_id_set bpf_key_sig_kfunc_set = { 1416 .owner = THIS_MODULE, 1417 .set = &key_sig_kfunc_set, 1418 }; 1419 1420 static int __init bpf_key_sig_kfuncs_init(void) 1421 { 1422 return register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, 1423 &bpf_key_sig_kfunc_set); 1424 } 1425 1426 late_initcall(bpf_key_sig_kfuncs_init); 1427 #endif /* CONFIG_KEYS */ 1428 1429 static const struct bpf_func_proto * 1430 bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1431 { 1432 switch (func_id) { 1433 case BPF_FUNC_map_lookup_elem: 1434 return &bpf_map_lookup_elem_proto; 1435 case BPF_FUNC_map_update_elem: 1436 return &bpf_map_update_elem_proto; 1437 case BPF_FUNC_map_delete_elem: 1438 return &bpf_map_delete_elem_proto; 1439 case BPF_FUNC_map_push_elem: 1440 return &bpf_map_push_elem_proto; 1441 case BPF_FUNC_map_pop_elem: 1442 return &bpf_map_pop_elem_proto; 1443 case BPF_FUNC_map_peek_elem: 1444 return &bpf_map_peek_elem_proto; 1445 case BPF_FUNC_map_lookup_percpu_elem: 1446 return &bpf_map_lookup_percpu_elem_proto; 1447 case BPF_FUNC_ktime_get_ns: 1448 return &bpf_ktime_get_ns_proto; 1449 case BPF_FUNC_ktime_get_boot_ns: 1450 return &bpf_ktime_get_boot_ns_proto; 1451 case BPF_FUNC_tail_call: 1452 return &bpf_tail_call_proto; 1453 case BPF_FUNC_get_current_pid_tgid: 1454 return &bpf_get_current_pid_tgid_proto; 1455 case BPF_FUNC_get_current_task: 1456 return &bpf_get_current_task_proto; 1457 case BPF_FUNC_get_current_task_btf: 1458 return &bpf_get_current_task_btf_proto; 1459 case BPF_FUNC_task_pt_regs: 1460 return &bpf_task_pt_regs_proto; 1461 case BPF_FUNC_get_current_uid_gid: 1462 return &bpf_get_current_uid_gid_proto; 1463 case BPF_FUNC_get_current_comm: 1464 return &bpf_get_current_comm_proto; 1465 case BPF_FUNC_trace_printk: 1466 return bpf_get_trace_printk_proto(); 1467 case BPF_FUNC_get_smp_processor_id: 1468 return &bpf_get_smp_processor_id_proto; 1469 case BPF_FUNC_get_numa_node_id: 1470 return &bpf_get_numa_node_id_proto; 1471 case BPF_FUNC_perf_event_read: 1472 return &bpf_perf_event_read_proto; 1473 case BPF_FUNC_current_task_under_cgroup: 1474 return &bpf_current_task_under_cgroup_proto; 1475 case BPF_FUNC_get_prandom_u32: 1476 return &bpf_get_prandom_u32_proto; 1477 case BPF_FUNC_probe_write_user: 1478 return security_locked_down(LOCKDOWN_BPF_WRITE_USER) < 0 ? 1479 NULL : bpf_get_probe_write_proto(); 1480 case BPF_FUNC_probe_read_user: 1481 return &bpf_probe_read_user_proto; 1482 case BPF_FUNC_probe_read_kernel: 1483 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1484 NULL : &bpf_probe_read_kernel_proto; 1485 case BPF_FUNC_probe_read_user_str: 1486 return &bpf_probe_read_user_str_proto; 1487 case BPF_FUNC_probe_read_kernel_str: 1488 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1489 NULL : &bpf_probe_read_kernel_str_proto; 1490 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 1491 case BPF_FUNC_probe_read: 1492 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1493 NULL : &bpf_probe_read_compat_proto; 1494 case BPF_FUNC_probe_read_str: 1495 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1496 NULL : &bpf_probe_read_compat_str_proto; 1497 #endif 1498 #ifdef CONFIG_CGROUPS 1499 case BPF_FUNC_cgrp_storage_get: 1500 return &bpf_cgrp_storage_get_proto; 1501 case BPF_FUNC_cgrp_storage_delete: 1502 return &bpf_cgrp_storage_delete_proto; 1503 #endif 1504 case BPF_FUNC_send_signal: 1505 return &bpf_send_signal_proto; 1506 case BPF_FUNC_send_signal_thread: 1507 return &bpf_send_signal_thread_proto; 1508 case BPF_FUNC_perf_event_read_value: 1509 return &bpf_perf_event_read_value_proto; 1510 case BPF_FUNC_get_ns_current_pid_tgid: 1511 return &bpf_get_ns_current_pid_tgid_proto; 1512 case BPF_FUNC_ringbuf_output: 1513 return &bpf_ringbuf_output_proto; 1514 case BPF_FUNC_ringbuf_reserve: 1515 return &bpf_ringbuf_reserve_proto; 1516 case BPF_FUNC_ringbuf_submit: 1517 return &bpf_ringbuf_submit_proto; 1518 case BPF_FUNC_ringbuf_discard: 1519 return &bpf_ringbuf_discard_proto; 1520 case BPF_FUNC_ringbuf_query: 1521 return &bpf_ringbuf_query_proto; 1522 case BPF_FUNC_jiffies64: 1523 return &bpf_jiffies64_proto; 1524 case BPF_FUNC_get_task_stack: 1525 return &bpf_get_task_stack_proto; 1526 case BPF_FUNC_copy_from_user: 1527 return &bpf_copy_from_user_proto; 1528 case BPF_FUNC_copy_from_user_task: 1529 return &bpf_copy_from_user_task_proto; 1530 case BPF_FUNC_snprintf_btf: 1531 return &bpf_snprintf_btf_proto; 1532 case BPF_FUNC_per_cpu_ptr: 1533 return &bpf_per_cpu_ptr_proto; 1534 case BPF_FUNC_this_cpu_ptr: 1535 return &bpf_this_cpu_ptr_proto; 1536 case BPF_FUNC_task_storage_get: 1537 if (bpf_prog_check_recur(prog)) 1538 return &bpf_task_storage_get_recur_proto; 1539 return &bpf_task_storage_get_proto; 1540 case BPF_FUNC_task_storage_delete: 1541 if (bpf_prog_check_recur(prog)) 1542 return &bpf_task_storage_delete_recur_proto; 1543 return &bpf_task_storage_delete_proto; 1544 case BPF_FUNC_for_each_map_elem: 1545 return &bpf_for_each_map_elem_proto; 1546 case BPF_FUNC_snprintf: 1547 return &bpf_snprintf_proto; 1548 case BPF_FUNC_get_func_ip: 1549 return &bpf_get_func_ip_proto_tracing; 1550 case BPF_FUNC_get_branch_snapshot: 1551 return &bpf_get_branch_snapshot_proto; 1552 case BPF_FUNC_find_vma: 1553 return &bpf_find_vma_proto; 1554 case BPF_FUNC_trace_vprintk: 1555 return bpf_get_trace_vprintk_proto(); 1556 default: 1557 return bpf_base_func_proto(func_id); 1558 } 1559 } 1560 1561 static const struct bpf_func_proto * 1562 kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1563 { 1564 switch (func_id) { 1565 case BPF_FUNC_perf_event_output: 1566 return &bpf_perf_event_output_proto; 1567 case BPF_FUNC_get_stackid: 1568 return &bpf_get_stackid_proto; 1569 case BPF_FUNC_get_stack: 1570 return &bpf_get_stack_proto; 1571 #ifdef CONFIG_BPF_KPROBE_OVERRIDE 1572 case BPF_FUNC_override_return: 1573 return &bpf_override_return_proto; 1574 #endif 1575 case BPF_FUNC_get_func_ip: 1576 if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI) 1577 return &bpf_get_func_ip_proto_kprobe_multi; 1578 if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI) 1579 return &bpf_get_func_ip_proto_uprobe_multi; 1580 return &bpf_get_func_ip_proto_kprobe; 1581 case BPF_FUNC_get_attach_cookie: 1582 if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI) 1583 return &bpf_get_attach_cookie_proto_kmulti; 1584 if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI) 1585 return &bpf_get_attach_cookie_proto_umulti; 1586 return &bpf_get_attach_cookie_proto_trace; 1587 default: 1588 return bpf_tracing_func_proto(func_id, prog); 1589 } 1590 } 1591 1592 /* bpf+kprobe programs can access fields of 'struct pt_regs' */ 1593 static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type, 1594 const struct bpf_prog *prog, 1595 struct bpf_insn_access_aux *info) 1596 { 1597 if (off < 0 || off >= sizeof(struct pt_regs)) 1598 return false; 1599 if (type != BPF_READ) 1600 return false; 1601 if (off % size != 0) 1602 return false; 1603 /* 1604 * Assertion for 32 bit to make sure last 8 byte access 1605 * (BPF_DW) to the last 4 byte member is disallowed. 1606 */ 1607 if (off + size > sizeof(struct pt_regs)) 1608 return false; 1609 1610 return true; 1611 } 1612 1613 const struct bpf_verifier_ops kprobe_verifier_ops = { 1614 .get_func_proto = kprobe_prog_func_proto, 1615 .is_valid_access = kprobe_prog_is_valid_access, 1616 }; 1617 1618 const struct bpf_prog_ops kprobe_prog_ops = { 1619 }; 1620 1621 BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map, 1622 u64, flags, void *, data, u64, size) 1623 { 1624 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1625 1626 /* 1627 * r1 points to perf tracepoint buffer where first 8 bytes are hidden 1628 * from bpf program and contain a pointer to 'struct pt_regs'. Fetch it 1629 * from there and call the same bpf_perf_event_output() helper inline. 1630 */ 1631 return ____bpf_perf_event_output(regs, map, flags, data, size); 1632 } 1633 1634 static const struct bpf_func_proto bpf_perf_event_output_proto_tp = { 1635 .func = bpf_perf_event_output_tp, 1636 .gpl_only = true, 1637 .ret_type = RET_INTEGER, 1638 .arg1_type = ARG_PTR_TO_CTX, 1639 .arg2_type = ARG_CONST_MAP_PTR, 1640 .arg3_type = ARG_ANYTHING, 1641 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1642 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 1643 }; 1644 1645 BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map, 1646 u64, flags) 1647 { 1648 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1649 1650 /* 1651 * Same comment as in bpf_perf_event_output_tp(), only that this time 1652 * the other helper's function body cannot be inlined due to being 1653 * external, thus we need to call raw helper function. 1654 */ 1655 return bpf_get_stackid((unsigned long) regs, (unsigned long) map, 1656 flags, 0, 0); 1657 } 1658 1659 static const struct bpf_func_proto bpf_get_stackid_proto_tp = { 1660 .func = bpf_get_stackid_tp, 1661 .gpl_only = true, 1662 .ret_type = RET_INTEGER, 1663 .arg1_type = ARG_PTR_TO_CTX, 1664 .arg2_type = ARG_CONST_MAP_PTR, 1665 .arg3_type = ARG_ANYTHING, 1666 }; 1667 1668 BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size, 1669 u64, flags) 1670 { 1671 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1672 1673 return bpf_get_stack((unsigned long) regs, (unsigned long) buf, 1674 (unsigned long) size, flags, 0); 1675 } 1676 1677 static const struct bpf_func_proto bpf_get_stack_proto_tp = { 1678 .func = bpf_get_stack_tp, 1679 .gpl_only = true, 1680 .ret_type = RET_INTEGER, 1681 .arg1_type = ARG_PTR_TO_CTX, 1682 .arg2_type = ARG_PTR_TO_UNINIT_MEM, 1683 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1684 .arg4_type = ARG_ANYTHING, 1685 }; 1686 1687 static const struct bpf_func_proto * 1688 tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1689 { 1690 switch (func_id) { 1691 case BPF_FUNC_perf_event_output: 1692 return &bpf_perf_event_output_proto_tp; 1693 case BPF_FUNC_get_stackid: 1694 return &bpf_get_stackid_proto_tp; 1695 case BPF_FUNC_get_stack: 1696 return &bpf_get_stack_proto_tp; 1697 case BPF_FUNC_get_attach_cookie: 1698 return &bpf_get_attach_cookie_proto_trace; 1699 default: 1700 return bpf_tracing_func_proto(func_id, prog); 1701 } 1702 } 1703 1704 static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type, 1705 const struct bpf_prog *prog, 1706 struct bpf_insn_access_aux *info) 1707 { 1708 if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE) 1709 return false; 1710 if (type != BPF_READ) 1711 return false; 1712 if (off % size != 0) 1713 return false; 1714 1715 BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(__u64)); 1716 return true; 1717 } 1718 1719 const struct bpf_verifier_ops tracepoint_verifier_ops = { 1720 .get_func_proto = tp_prog_func_proto, 1721 .is_valid_access = tp_prog_is_valid_access, 1722 }; 1723 1724 const struct bpf_prog_ops tracepoint_prog_ops = { 1725 }; 1726 1727 BPF_CALL_3(bpf_perf_prog_read_value, struct bpf_perf_event_data_kern *, ctx, 1728 struct bpf_perf_event_value *, buf, u32, size) 1729 { 1730 int err = -EINVAL; 1731 1732 if (unlikely(size != sizeof(struct bpf_perf_event_value))) 1733 goto clear; 1734 err = perf_event_read_local(ctx->event, &buf->counter, &buf->enabled, 1735 &buf->running); 1736 if (unlikely(err)) 1737 goto clear; 1738 return 0; 1739 clear: 1740 memset(buf, 0, size); 1741 return err; 1742 } 1743 1744 static const struct bpf_func_proto bpf_perf_prog_read_value_proto = { 1745 .func = bpf_perf_prog_read_value, 1746 .gpl_only = true, 1747 .ret_type = RET_INTEGER, 1748 .arg1_type = ARG_PTR_TO_CTX, 1749 .arg2_type = ARG_PTR_TO_UNINIT_MEM, 1750 .arg3_type = ARG_CONST_SIZE, 1751 }; 1752 1753 BPF_CALL_4(bpf_read_branch_records, struct bpf_perf_event_data_kern *, ctx, 1754 void *, buf, u32, size, u64, flags) 1755 { 1756 static const u32 br_entry_size = sizeof(struct perf_branch_entry); 1757 struct perf_branch_stack *br_stack = ctx->data->br_stack; 1758 u32 to_copy; 1759 1760 if (unlikely(flags & ~BPF_F_GET_BRANCH_RECORDS_SIZE)) 1761 return -EINVAL; 1762 1763 if (unlikely(!(ctx->data->sample_flags & PERF_SAMPLE_BRANCH_STACK))) 1764 return -ENOENT; 1765 1766 if (unlikely(!br_stack)) 1767 return -ENOENT; 1768 1769 if (flags & BPF_F_GET_BRANCH_RECORDS_SIZE) 1770 return br_stack->nr * br_entry_size; 1771 1772 if (!buf || (size % br_entry_size != 0)) 1773 return -EINVAL; 1774 1775 to_copy = min_t(u32, br_stack->nr * br_entry_size, size); 1776 memcpy(buf, br_stack->entries, to_copy); 1777 1778 return to_copy; 1779 } 1780 1781 static const struct bpf_func_proto bpf_read_branch_records_proto = { 1782 .func = bpf_read_branch_records, 1783 .gpl_only = true, 1784 .ret_type = RET_INTEGER, 1785 .arg1_type = ARG_PTR_TO_CTX, 1786 .arg2_type = ARG_PTR_TO_MEM_OR_NULL, 1787 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1788 .arg4_type = ARG_ANYTHING, 1789 }; 1790 1791 static const struct bpf_func_proto * 1792 pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1793 { 1794 switch (func_id) { 1795 case BPF_FUNC_perf_event_output: 1796 return &bpf_perf_event_output_proto_tp; 1797 case BPF_FUNC_get_stackid: 1798 return &bpf_get_stackid_proto_pe; 1799 case BPF_FUNC_get_stack: 1800 return &bpf_get_stack_proto_pe; 1801 case BPF_FUNC_perf_prog_read_value: 1802 return &bpf_perf_prog_read_value_proto; 1803 case BPF_FUNC_read_branch_records: 1804 return &bpf_read_branch_records_proto; 1805 case BPF_FUNC_get_attach_cookie: 1806 return &bpf_get_attach_cookie_proto_pe; 1807 default: 1808 return bpf_tracing_func_proto(func_id, prog); 1809 } 1810 } 1811 1812 /* 1813 * bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp 1814 * to avoid potential recursive reuse issue when/if tracepoints are added 1815 * inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack. 1816 * 1817 * Since raw tracepoints run despite bpf_prog_active, support concurrent usage 1818 * in normal, irq, and nmi context. 1819 */ 1820 struct bpf_raw_tp_regs { 1821 struct pt_regs regs[3]; 1822 }; 1823 static DEFINE_PER_CPU(struct bpf_raw_tp_regs, bpf_raw_tp_regs); 1824 static DEFINE_PER_CPU(int, bpf_raw_tp_nest_level); 1825 static struct pt_regs *get_bpf_raw_tp_regs(void) 1826 { 1827 struct bpf_raw_tp_regs *tp_regs = this_cpu_ptr(&bpf_raw_tp_regs); 1828 int nest_level = this_cpu_inc_return(bpf_raw_tp_nest_level); 1829 1830 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(tp_regs->regs))) { 1831 this_cpu_dec(bpf_raw_tp_nest_level); 1832 return ERR_PTR(-EBUSY); 1833 } 1834 1835 return &tp_regs->regs[nest_level - 1]; 1836 } 1837 1838 static void put_bpf_raw_tp_regs(void) 1839 { 1840 this_cpu_dec(bpf_raw_tp_nest_level); 1841 } 1842 1843 BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args, 1844 struct bpf_map *, map, u64, flags, void *, data, u64, size) 1845 { 1846 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1847 int ret; 1848 1849 if (IS_ERR(regs)) 1850 return PTR_ERR(regs); 1851 1852 perf_fetch_caller_regs(regs); 1853 ret = ____bpf_perf_event_output(regs, map, flags, data, size); 1854 1855 put_bpf_raw_tp_regs(); 1856 return ret; 1857 } 1858 1859 static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = { 1860 .func = bpf_perf_event_output_raw_tp, 1861 .gpl_only = true, 1862 .ret_type = RET_INTEGER, 1863 .arg1_type = ARG_PTR_TO_CTX, 1864 .arg2_type = ARG_CONST_MAP_PTR, 1865 .arg3_type = ARG_ANYTHING, 1866 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1867 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 1868 }; 1869 1870 extern const struct bpf_func_proto bpf_skb_output_proto; 1871 extern const struct bpf_func_proto bpf_xdp_output_proto; 1872 extern const struct bpf_func_proto bpf_xdp_get_buff_len_trace_proto; 1873 1874 BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args, 1875 struct bpf_map *, map, u64, flags) 1876 { 1877 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1878 int ret; 1879 1880 if (IS_ERR(regs)) 1881 return PTR_ERR(regs); 1882 1883 perf_fetch_caller_regs(regs); 1884 /* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */ 1885 ret = bpf_get_stackid((unsigned long) regs, (unsigned long) map, 1886 flags, 0, 0); 1887 put_bpf_raw_tp_regs(); 1888 return ret; 1889 } 1890 1891 static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = { 1892 .func = bpf_get_stackid_raw_tp, 1893 .gpl_only = true, 1894 .ret_type = RET_INTEGER, 1895 .arg1_type = ARG_PTR_TO_CTX, 1896 .arg2_type = ARG_CONST_MAP_PTR, 1897 .arg3_type = ARG_ANYTHING, 1898 }; 1899 1900 BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args, 1901 void *, buf, u32, size, u64, flags) 1902 { 1903 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1904 int ret; 1905 1906 if (IS_ERR(regs)) 1907 return PTR_ERR(regs); 1908 1909 perf_fetch_caller_regs(regs); 1910 ret = bpf_get_stack((unsigned long) regs, (unsigned long) buf, 1911 (unsigned long) size, flags, 0); 1912 put_bpf_raw_tp_regs(); 1913 return ret; 1914 } 1915 1916 static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = { 1917 .func = bpf_get_stack_raw_tp, 1918 .gpl_only = true, 1919 .ret_type = RET_INTEGER, 1920 .arg1_type = ARG_PTR_TO_CTX, 1921 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1922 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1923 .arg4_type = ARG_ANYTHING, 1924 }; 1925 1926 static const struct bpf_func_proto * 1927 raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1928 { 1929 switch (func_id) { 1930 case BPF_FUNC_perf_event_output: 1931 return &bpf_perf_event_output_proto_raw_tp; 1932 case BPF_FUNC_get_stackid: 1933 return &bpf_get_stackid_proto_raw_tp; 1934 case BPF_FUNC_get_stack: 1935 return &bpf_get_stack_proto_raw_tp; 1936 default: 1937 return bpf_tracing_func_proto(func_id, prog); 1938 } 1939 } 1940 1941 const struct bpf_func_proto * 1942 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1943 { 1944 const struct bpf_func_proto *fn; 1945 1946 switch (func_id) { 1947 #ifdef CONFIG_NET 1948 case BPF_FUNC_skb_output: 1949 return &bpf_skb_output_proto; 1950 case BPF_FUNC_xdp_output: 1951 return &bpf_xdp_output_proto; 1952 case BPF_FUNC_skc_to_tcp6_sock: 1953 return &bpf_skc_to_tcp6_sock_proto; 1954 case BPF_FUNC_skc_to_tcp_sock: 1955 return &bpf_skc_to_tcp_sock_proto; 1956 case BPF_FUNC_skc_to_tcp_timewait_sock: 1957 return &bpf_skc_to_tcp_timewait_sock_proto; 1958 case BPF_FUNC_skc_to_tcp_request_sock: 1959 return &bpf_skc_to_tcp_request_sock_proto; 1960 case BPF_FUNC_skc_to_udp6_sock: 1961 return &bpf_skc_to_udp6_sock_proto; 1962 case BPF_FUNC_skc_to_unix_sock: 1963 return &bpf_skc_to_unix_sock_proto; 1964 case BPF_FUNC_skc_to_mptcp_sock: 1965 return &bpf_skc_to_mptcp_sock_proto; 1966 case BPF_FUNC_sk_storage_get: 1967 return &bpf_sk_storage_get_tracing_proto; 1968 case BPF_FUNC_sk_storage_delete: 1969 return &bpf_sk_storage_delete_tracing_proto; 1970 case BPF_FUNC_sock_from_file: 1971 return &bpf_sock_from_file_proto; 1972 case BPF_FUNC_get_socket_cookie: 1973 return &bpf_get_socket_ptr_cookie_proto; 1974 case BPF_FUNC_xdp_get_buff_len: 1975 return &bpf_xdp_get_buff_len_trace_proto; 1976 #endif 1977 case BPF_FUNC_seq_printf: 1978 return prog->expected_attach_type == BPF_TRACE_ITER ? 1979 &bpf_seq_printf_proto : 1980 NULL; 1981 case BPF_FUNC_seq_write: 1982 return prog->expected_attach_type == BPF_TRACE_ITER ? 1983 &bpf_seq_write_proto : 1984 NULL; 1985 case BPF_FUNC_seq_printf_btf: 1986 return prog->expected_attach_type == BPF_TRACE_ITER ? 1987 &bpf_seq_printf_btf_proto : 1988 NULL; 1989 case BPF_FUNC_d_path: 1990 return &bpf_d_path_proto; 1991 case BPF_FUNC_get_func_arg: 1992 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_proto : NULL; 1993 case BPF_FUNC_get_func_ret: 1994 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_ret_proto : NULL; 1995 case BPF_FUNC_get_func_arg_cnt: 1996 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_cnt_proto : NULL; 1997 case BPF_FUNC_get_attach_cookie: 1998 return bpf_prog_has_trampoline(prog) ? &bpf_get_attach_cookie_proto_tracing : NULL; 1999 default: 2000 fn = raw_tp_prog_func_proto(func_id, prog); 2001 if (!fn && prog->expected_attach_type == BPF_TRACE_ITER) 2002 fn = bpf_iter_get_func_proto(func_id, prog); 2003 return fn; 2004 } 2005 } 2006 2007 static bool raw_tp_prog_is_valid_access(int off, int size, 2008 enum bpf_access_type type, 2009 const struct bpf_prog *prog, 2010 struct bpf_insn_access_aux *info) 2011 { 2012 return bpf_tracing_ctx_access(off, size, type); 2013 } 2014 2015 static bool tracing_prog_is_valid_access(int off, int size, 2016 enum bpf_access_type type, 2017 const struct bpf_prog *prog, 2018 struct bpf_insn_access_aux *info) 2019 { 2020 return bpf_tracing_btf_ctx_access(off, size, type, prog, info); 2021 } 2022 2023 int __weak bpf_prog_test_run_tracing(struct bpf_prog *prog, 2024 const union bpf_attr *kattr, 2025 union bpf_attr __user *uattr) 2026 { 2027 return -ENOTSUPP; 2028 } 2029 2030 const struct bpf_verifier_ops raw_tracepoint_verifier_ops = { 2031 .get_func_proto = raw_tp_prog_func_proto, 2032 .is_valid_access = raw_tp_prog_is_valid_access, 2033 }; 2034 2035 const struct bpf_prog_ops raw_tracepoint_prog_ops = { 2036 #ifdef CONFIG_NET 2037 .test_run = bpf_prog_test_run_raw_tp, 2038 #endif 2039 }; 2040 2041 const struct bpf_verifier_ops tracing_verifier_ops = { 2042 .get_func_proto = tracing_prog_func_proto, 2043 .is_valid_access = tracing_prog_is_valid_access, 2044 }; 2045 2046 const struct bpf_prog_ops tracing_prog_ops = { 2047 .test_run = bpf_prog_test_run_tracing, 2048 }; 2049 2050 static bool raw_tp_writable_prog_is_valid_access(int off, int size, 2051 enum bpf_access_type type, 2052 const struct bpf_prog *prog, 2053 struct bpf_insn_access_aux *info) 2054 { 2055 if (off == 0) { 2056 if (size != sizeof(u64) || type != BPF_READ) 2057 return false; 2058 info->reg_type = PTR_TO_TP_BUFFER; 2059 } 2060 return raw_tp_prog_is_valid_access(off, size, type, prog, info); 2061 } 2062 2063 const struct bpf_verifier_ops raw_tracepoint_writable_verifier_ops = { 2064 .get_func_proto = raw_tp_prog_func_proto, 2065 .is_valid_access = raw_tp_writable_prog_is_valid_access, 2066 }; 2067 2068 const struct bpf_prog_ops raw_tracepoint_writable_prog_ops = { 2069 }; 2070 2071 static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type, 2072 const struct bpf_prog *prog, 2073 struct bpf_insn_access_aux *info) 2074 { 2075 const int size_u64 = sizeof(u64); 2076 2077 if (off < 0 || off >= sizeof(struct bpf_perf_event_data)) 2078 return false; 2079 if (type != BPF_READ) 2080 return false; 2081 if (off % size != 0) { 2082 if (sizeof(unsigned long) != 4) 2083 return false; 2084 if (size != 8) 2085 return false; 2086 if (off % size != 4) 2087 return false; 2088 } 2089 2090 switch (off) { 2091 case bpf_ctx_range(struct bpf_perf_event_data, sample_period): 2092 bpf_ctx_record_field_size(info, size_u64); 2093 if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) 2094 return false; 2095 break; 2096 case bpf_ctx_range(struct bpf_perf_event_data, addr): 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 default: 2102 if (size != sizeof(long)) 2103 return false; 2104 } 2105 2106 return true; 2107 } 2108 2109 static u32 pe_prog_convert_ctx_access(enum bpf_access_type type, 2110 const struct bpf_insn *si, 2111 struct bpf_insn *insn_buf, 2112 struct bpf_prog *prog, u32 *target_size) 2113 { 2114 struct bpf_insn *insn = insn_buf; 2115 2116 switch (si->off) { 2117 case offsetof(struct bpf_perf_event_data, sample_period): 2118 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 2119 data), si->dst_reg, si->src_reg, 2120 offsetof(struct bpf_perf_event_data_kern, data)); 2121 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, 2122 bpf_target_off(struct perf_sample_data, period, 8, 2123 target_size)); 2124 break; 2125 case offsetof(struct bpf_perf_event_data, addr): 2126 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 2127 data), si->dst_reg, si->src_reg, 2128 offsetof(struct bpf_perf_event_data_kern, data)); 2129 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, 2130 bpf_target_off(struct perf_sample_data, addr, 8, 2131 target_size)); 2132 break; 2133 default: 2134 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 2135 regs), si->dst_reg, si->src_reg, 2136 offsetof(struct bpf_perf_event_data_kern, regs)); 2137 *insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg, 2138 si->off); 2139 break; 2140 } 2141 2142 return insn - insn_buf; 2143 } 2144 2145 const struct bpf_verifier_ops perf_event_verifier_ops = { 2146 .get_func_proto = pe_prog_func_proto, 2147 .is_valid_access = pe_prog_is_valid_access, 2148 .convert_ctx_access = pe_prog_convert_ctx_access, 2149 }; 2150 2151 const struct bpf_prog_ops perf_event_prog_ops = { 2152 }; 2153 2154 static DEFINE_MUTEX(bpf_event_mutex); 2155 2156 #define BPF_TRACE_MAX_PROGS 64 2157 2158 int perf_event_attach_bpf_prog(struct perf_event *event, 2159 struct bpf_prog *prog, 2160 u64 bpf_cookie) 2161 { 2162 struct bpf_prog_array *old_array; 2163 struct bpf_prog_array *new_array; 2164 int ret = -EEXIST; 2165 2166 /* 2167 * Kprobe override only works if they are on the function entry, 2168 * and only if they are on the opt-in list. 2169 */ 2170 if (prog->kprobe_override && 2171 (!trace_kprobe_on_func_entry(event->tp_event) || 2172 !trace_kprobe_error_injectable(event->tp_event))) 2173 return -EINVAL; 2174 2175 mutex_lock(&bpf_event_mutex); 2176 2177 if (event->prog) 2178 goto unlock; 2179 2180 old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); 2181 if (old_array && 2182 bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) { 2183 ret = -E2BIG; 2184 goto unlock; 2185 } 2186 2187 ret = bpf_prog_array_copy(old_array, NULL, prog, bpf_cookie, &new_array); 2188 if (ret < 0) 2189 goto unlock; 2190 2191 /* set the new array to event->tp_event and set event->prog */ 2192 event->prog = prog; 2193 event->bpf_cookie = bpf_cookie; 2194 rcu_assign_pointer(event->tp_event->prog_array, new_array); 2195 bpf_prog_array_free_sleepable(old_array); 2196 2197 unlock: 2198 mutex_unlock(&bpf_event_mutex); 2199 return ret; 2200 } 2201 2202 void perf_event_detach_bpf_prog(struct perf_event *event) 2203 { 2204 struct bpf_prog_array *old_array; 2205 struct bpf_prog_array *new_array; 2206 int ret; 2207 2208 mutex_lock(&bpf_event_mutex); 2209 2210 if (!event->prog) 2211 goto unlock; 2212 2213 old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); 2214 ret = bpf_prog_array_copy(old_array, event->prog, NULL, 0, &new_array); 2215 if (ret == -ENOENT) 2216 goto unlock; 2217 if (ret < 0) { 2218 bpf_prog_array_delete_safe(old_array, event->prog); 2219 } else { 2220 rcu_assign_pointer(event->tp_event->prog_array, new_array); 2221 bpf_prog_array_free_sleepable(old_array); 2222 } 2223 2224 bpf_prog_put(event->prog); 2225 event->prog = NULL; 2226 2227 unlock: 2228 mutex_unlock(&bpf_event_mutex); 2229 } 2230 2231 int perf_event_query_prog_array(struct perf_event *event, void __user *info) 2232 { 2233 struct perf_event_query_bpf __user *uquery = info; 2234 struct perf_event_query_bpf query = {}; 2235 struct bpf_prog_array *progs; 2236 u32 *ids, prog_cnt, ids_len; 2237 int ret; 2238 2239 if (!perfmon_capable()) 2240 return -EPERM; 2241 if (event->attr.type != PERF_TYPE_TRACEPOINT) 2242 return -EINVAL; 2243 if (copy_from_user(&query, uquery, sizeof(query))) 2244 return -EFAULT; 2245 2246 ids_len = query.ids_len; 2247 if (ids_len > BPF_TRACE_MAX_PROGS) 2248 return -E2BIG; 2249 ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN); 2250 if (!ids) 2251 return -ENOMEM; 2252 /* 2253 * The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which 2254 * is required when user only wants to check for uquery->prog_cnt. 2255 * There is no need to check for it since the case is handled 2256 * gracefully in bpf_prog_array_copy_info. 2257 */ 2258 2259 mutex_lock(&bpf_event_mutex); 2260 progs = bpf_event_rcu_dereference(event->tp_event->prog_array); 2261 ret = bpf_prog_array_copy_info(progs, ids, ids_len, &prog_cnt); 2262 mutex_unlock(&bpf_event_mutex); 2263 2264 if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) || 2265 copy_to_user(uquery->ids, ids, ids_len * sizeof(u32))) 2266 ret = -EFAULT; 2267 2268 kfree(ids); 2269 return ret; 2270 } 2271 2272 extern struct bpf_raw_event_map __start__bpf_raw_tp[]; 2273 extern struct bpf_raw_event_map __stop__bpf_raw_tp[]; 2274 2275 struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name) 2276 { 2277 struct bpf_raw_event_map *btp = __start__bpf_raw_tp; 2278 2279 for (; btp < __stop__bpf_raw_tp; btp++) { 2280 if (!strcmp(btp->tp->name, name)) 2281 return btp; 2282 } 2283 2284 return bpf_get_raw_tracepoint_module(name); 2285 } 2286 2287 void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp) 2288 { 2289 struct module *mod; 2290 2291 preempt_disable(); 2292 mod = __module_address((unsigned long)btp); 2293 module_put(mod); 2294 preempt_enable(); 2295 } 2296 2297 static __always_inline 2298 void __bpf_trace_run(struct bpf_prog *prog, u64 *args) 2299 { 2300 cant_sleep(); 2301 if (unlikely(this_cpu_inc_return(*(prog->active)) != 1)) { 2302 bpf_prog_inc_misses_counter(prog); 2303 goto out; 2304 } 2305 rcu_read_lock(); 2306 (void) bpf_prog_run(prog, args); 2307 rcu_read_unlock(); 2308 out: 2309 this_cpu_dec(*(prog->active)); 2310 } 2311 2312 #define UNPACK(...) __VA_ARGS__ 2313 #define REPEAT_1(FN, DL, X, ...) FN(X) 2314 #define REPEAT_2(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__) 2315 #define REPEAT_3(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_2(FN, DL, __VA_ARGS__) 2316 #define REPEAT_4(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_3(FN, DL, __VA_ARGS__) 2317 #define REPEAT_5(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_4(FN, DL, __VA_ARGS__) 2318 #define REPEAT_6(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_5(FN, DL, __VA_ARGS__) 2319 #define REPEAT_7(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_6(FN, DL, __VA_ARGS__) 2320 #define REPEAT_8(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_7(FN, DL, __VA_ARGS__) 2321 #define REPEAT_9(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_8(FN, DL, __VA_ARGS__) 2322 #define REPEAT_10(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_9(FN, DL, __VA_ARGS__) 2323 #define REPEAT_11(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_10(FN, DL, __VA_ARGS__) 2324 #define REPEAT_12(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_11(FN, DL, __VA_ARGS__) 2325 #define REPEAT(X, FN, DL, ...) REPEAT_##X(FN, DL, __VA_ARGS__) 2326 2327 #define SARG(X) u64 arg##X 2328 #define COPY(X) args[X] = arg##X 2329 2330 #define __DL_COM (,) 2331 #define __DL_SEM (;) 2332 2333 #define __SEQ_0_11 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 2334 2335 #define BPF_TRACE_DEFN_x(x) \ 2336 void bpf_trace_run##x(struct bpf_prog *prog, \ 2337 REPEAT(x, SARG, __DL_COM, __SEQ_0_11)) \ 2338 { \ 2339 u64 args[x]; \ 2340 REPEAT(x, COPY, __DL_SEM, __SEQ_0_11); \ 2341 __bpf_trace_run(prog, args); \ 2342 } \ 2343 EXPORT_SYMBOL_GPL(bpf_trace_run##x) 2344 BPF_TRACE_DEFN_x(1); 2345 BPF_TRACE_DEFN_x(2); 2346 BPF_TRACE_DEFN_x(3); 2347 BPF_TRACE_DEFN_x(4); 2348 BPF_TRACE_DEFN_x(5); 2349 BPF_TRACE_DEFN_x(6); 2350 BPF_TRACE_DEFN_x(7); 2351 BPF_TRACE_DEFN_x(8); 2352 BPF_TRACE_DEFN_x(9); 2353 BPF_TRACE_DEFN_x(10); 2354 BPF_TRACE_DEFN_x(11); 2355 BPF_TRACE_DEFN_x(12); 2356 2357 static int __bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog) 2358 { 2359 struct tracepoint *tp = btp->tp; 2360 2361 /* 2362 * check that program doesn't access arguments beyond what's 2363 * available in this tracepoint 2364 */ 2365 if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64)) 2366 return -EINVAL; 2367 2368 if (prog->aux->max_tp_access > btp->writable_size) 2369 return -EINVAL; 2370 2371 return tracepoint_probe_register_may_exist(tp, (void *)btp->bpf_func, 2372 prog); 2373 } 2374 2375 int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog) 2376 { 2377 return __bpf_probe_register(btp, prog); 2378 } 2379 2380 int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_prog *prog) 2381 { 2382 return tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, prog); 2383 } 2384 2385 int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id, 2386 u32 *fd_type, const char **buf, 2387 u64 *probe_offset, u64 *probe_addr) 2388 { 2389 bool is_tracepoint, is_syscall_tp; 2390 struct bpf_prog *prog; 2391 int flags, err = 0; 2392 2393 prog = event->prog; 2394 if (!prog) 2395 return -ENOENT; 2396 2397 /* not supporting BPF_PROG_TYPE_PERF_EVENT yet */ 2398 if (prog->type == BPF_PROG_TYPE_PERF_EVENT) 2399 return -EOPNOTSUPP; 2400 2401 *prog_id = prog->aux->id; 2402 flags = event->tp_event->flags; 2403 is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT; 2404 is_syscall_tp = is_syscall_trace_event(event->tp_event); 2405 2406 if (is_tracepoint || is_syscall_tp) { 2407 *buf = is_tracepoint ? event->tp_event->tp->name 2408 : event->tp_event->name; 2409 /* We allow NULL pointer for tracepoint */ 2410 if (fd_type) 2411 *fd_type = BPF_FD_TYPE_TRACEPOINT; 2412 if (probe_offset) 2413 *probe_offset = 0x0; 2414 if (probe_addr) 2415 *probe_addr = 0x0; 2416 } else { 2417 /* kprobe/uprobe */ 2418 err = -EOPNOTSUPP; 2419 #ifdef CONFIG_KPROBE_EVENTS 2420 if (flags & TRACE_EVENT_FL_KPROBE) 2421 err = bpf_get_kprobe_info(event, fd_type, buf, 2422 probe_offset, probe_addr, 2423 event->attr.type == PERF_TYPE_TRACEPOINT); 2424 #endif 2425 #ifdef CONFIG_UPROBE_EVENTS 2426 if (flags & TRACE_EVENT_FL_UPROBE) 2427 err = bpf_get_uprobe_info(event, fd_type, buf, 2428 probe_offset, probe_addr, 2429 event->attr.type == PERF_TYPE_TRACEPOINT); 2430 #endif 2431 } 2432 2433 return err; 2434 } 2435 2436 static int __init send_signal_irq_work_init(void) 2437 { 2438 int cpu; 2439 struct send_signal_irq_work *work; 2440 2441 for_each_possible_cpu(cpu) { 2442 work = per_cpu_ptr(&send_signal_work, cpu); 2443 init_irq_work(&work->irq_work, do_bpf_send_signal); 2444 } 2445 return 0; 2446 } 2447 2448 subsys_initcall(send_signal_irq_work_init); 2449 2450 #ifdef CONFIG_MODULES 2451 static int bpf_event_notify(struct notifier_block *nb, unsigned long op, 2452 void *module) 2453 { 2454 struct bpf_trace_module *btm, *tmp; 2455 struct module *mod = module; 2456 int ret = 0; 2457 2458 if (mod->num_bpf_raw_events == 0 || 2459 (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING)) 2460 goto out; 2461 2462 mutex_lock(&bpf_module_mutex); 2463 2464 switch (op) { 2465 case MODULE_STATE_COMING: 2466 btm = kzalloc(sizeof(*btm), GFP_KERNEL); 2467 if (btm) { 2468 btm->module = module; 2469 list_add(&btm->list, &bpf_trace_modules); 2470 } else { 2471 ret = -ENOMEM; 2472 } 2473 break; 2474 case MODULE_STATE_GOING: 2475 list_for_each_entry_safe(btm, tmp, &bpf_trace_modules, list) { 2476 if (btm->module == module) { 2477 list_del(&btm->list); 2478 kfree(btm); 2479 break; 2480 } 2481 } 2482 break; 2483 } 2484 2485 mutex_unlock(&bpf_module_mutex); 2486 2487 out: 2488 return notifier_from_errno(ret); 2489 } 2490 2491 static struct notifier_block bpf_module_nb = { 2492 .notifier_call = bpf_event_notify, 2493 }; 2494 2495 static int __init bpf_event_init(void) 2496 { 2497 register_module_notifier(&bpf_module_nb); 2498 return 0; 2499 } 2500 2501 fs_initcall(bpf_event_init); 2502 #endif /* CONFIG_MODULES */ 2503 2504 #ifdef CONFIG_FPROBE 2505 struct bpf_kprobe_multi_link { 2506 struct bpf_link link; 2507 struct fprobe fp; 2508 unsigned long *addrs; 2509 u64 *cookies; 2510 u32 cnt; 2511 u32 mods_cnt; 2512 struct module **mods; 2513 u32 flags; 2514 }; 2515 2516 struct bpf_kprobe_multi_run_ctx { 2517 struct bpf_run_ctx run_ctx; 2518 struct bpf_kprobe_multi_link *link; 2519 unsigned long entry_ip; 2520 }; 2521 2522 struct user_syms { 2523 const char **syms; 2524 char *buf; 2525 }; 2526 2527 static int copy_user_syms(struct user_syms *us, unsigned long __user *usyms, u32 cnt) 2528 { 2529 unsigned long __user usymbol; 2530 const char **syms = NULL; 2531 char *buf = NULL, *p; 2532 int err = -ENOMEM; 2533 unsigned int i; 2534 2535 syms = kvmalloc_array(cnt, sizeof(*syms), GFP_KERNEL); 2536 if (!syms) 2537 goto error; 2538 2539 buf = kvmalloc_array(cnt, KSYM_NAME_LEN, GFP_KERNEL); 2540 if (!buf) 2541 goto error; 2542 2543 for (p = buf, i = 0; i < cnt; i++) { 2544 if (__get_user(usymbol, usyms + i)) { 2545 err = -EFAULT; 2546 goto error; 2547 } 2548 err = strncpy_from_user(p, (const char __user *) usymbol, KSYM_NAME_LEN); 2549 if (err == KSYM_NAME_LEN) 2550 err = -E2BIG; 2551 if (err < 0) 2552 goto error; 2553 syms[i] = p; 2554 p += err + 1; 2555 } 2556 2557 us->syms = syms; 2558 us->buf = buf; 2559 return 0; 2560 2561 error: 2562 if (err) { 2563 kvfree(syms); 2564 kvfree(buf); 2565 } 2566 return err; 2567 } 2568 2569 static void kprobe_multi_put_modules(struct module **mods, u32 cnt) 2570 { 2571 u32 i; 2572 2573 for (i = 0; i < cnt; i++) 2574 module_put(mods[i]); 2575 } 2576 2577 static void free_user_syms(struct user_syms *us) 2578 { 2579 kvfree(us->syms); 2580 kvfree(us->buf); 2581 } 2582 2583 static void bpf_kprobe_multi_link_release(struct bpf_link *link) 2584 { 2585 struct bpf_kprobe_multi_link *kmulti_link; 2586 2587 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); 2588 unregister_fprobe(&kmulti_link->fp); 2589 kprobe_multi_put_modules(kmulti_link->mods, kmulti_link->mods_cnt); 2590 } 2591 2592 static void bpf_kprobe_multi_link_dealloc(struct bpf_link *link) 2593 { 2594 struct bpf_kprobe_multi_link *kmulti_link; 2595 2596 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); 2597 kvfree(kmulti_link->addrs); 2598 kvfree(kmulti_link->cookies); 2599 kfree(kmulti_link->mods); 2600 kfree(kmulti_link); 2601 } 2602 2603 static int bpf_kprobe_multi_link_fill_link_info(const struct bpf_link *link, 2604 struct bpf_link_info *info) 2605 { 2606 u64 __user *uaddrs = u64_to_user_ptr(info->kprobe_multi.addrs); 2607 struct bpf_kprobe_multi_link *kmulti_link; 2608 u32 ucount = info->kprobe_multi.count; 2609 int err = 0, i; 2610 2611 if (!uaddrs ^ !ucount) 2612 return -EINVAL; 2613 2614 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); 2615 info->kprobe_multi.count = kmulti_link->cnt; 2616 info->kprobe_multi.flags = kmulti_link->flags; 2617 2618 if (!uaddrs) 2619 return 0; 2620 if (ucount < kmulti_link->cnt) 2621 err = -ENOSPC; 2622 else 2623 ucount = kmulti_link->cnt; 2624 2625 if (kallsyms_show_value(current_cred())) { 2626 if (copy_to_user(uaddrs, kmulti_link->addrs, ucount * sizeof(u64))) 2627 return -EFAULT; 2628 } else { 2629 for (i = 0; i < ucount; i++) { 2630 if (put_user(0, uaddrs + i)) 2631 return -EFAULT; 2632 } 2633 } 2634 return err; 2635 } 2636 2637 static const struct bpf_link_ops bpf_kprobe_multi_link_lops = { 2638 .release = bpf_kprobe_multi_link_release, 2639 .dealloc = bpf_kprobe_multi_link_dealloc, 2640 .fill_link_info = bpf_kprobe_multi_link_fill_link_info, 2641 }; 2642 2643 static void bpf_kprobe_multi_cookie_swap(void *a, void *b, int size, const void *priv) 2644 { 2645 const struct bpf_kprobe_multi_link *link = priv; 2646 unsigned long *addr_a = a, *addr_b = b; 2647 u64 *cookie_a, *cookie_b; 2648 2649 cookie_a = link->cookies + (addr_a - link->addrs); 2650 cookie_b = link->cookies + (addr_b - link->addrs); 2651 2652 /* swap addr_a/addr_b and cookie_a/cookie_b values */ 2653 swap(*addr_a, *addr_b); 2654 swap(*cookie_a, *cookie_b); 2655 } 2656 2657 static int bpf_kprobe_multi_addrs_cmp(const void *a, const void *b) 2658 { 2659 const unsigned long *addr_a = a, *addr_b = b; 2660 2661 if (*addr_a == *addr_b) 2662 return 0; 2663 return *addr_a < *addr_b ? -1 : 1; 2664 } 2665 2666 static int bpf_kprobe_multi_cookie_cmp(const void *a, const void *b, const void *priv) 2667 { 2668 return bpf_kprobe_multi_addrs_cmp(a, b); 2669 } 2670 2671 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx) 2672 { 2673 struct bpf_kprobe_multi_run_ctx *run_ctx; 2674 struct bpf_kprobe_multi_link *link; 2675 u64 *cookie, entry_ip; 2676 unsigned long *addr; 2677 2678 if (WARN_ON_ONCE(!ctx)) 2679 return 0; 2680 run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, run_ctx); 2681 link = run_ctx->link; 2682 if (!link->cookies) 2683 return 0; 2684 entry_ip = run_ctx->entry_ip; 2685 addr = bsearch(&entry_ip, link->addrs, link->cnt, sizeof(entry_ip), 2686 bpf_kprobe_multi_addrs_cmp); 2687 if (!addr) 2688 return 0; 2689 cookie = link->cookies + (addr - link->addrs); 2690 return *cookie; 2691 } 2692 2693 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 2694 { 2695 struct bpf_kprobe_multi_run_ctx *run_ctx; 2696 2697 run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, run_ctx); 2698 return run_ctx->entry_ip; 2699 } 2700 2701 static int 2702 kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link, 2703 unsigned long entry_ip, struct pt_regs *regs) 2704 { 2705 struct bpf_kprobe_multi_run_ctx run_ctx = { 2706 .link = link, 2707 .entry_ip = entry_ip, 2708 }; 2709 struct bpf_run_ctx *old_run_ctx; 2710 int err; 2711 2712 if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) { 2713 err = 0; 2714 goto out; 2715 } 2716 2717 migrate_disable(); 2718 rcu_read_lock(); 2719 old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx); 2720 err = bpf_prog_run(link->link.prog, regs); 2721 bpf_reset_run_ctx(old_run_ctx); 2722 rcu_read_unlock(); 2723 migrate_enable(); 2724 2725 out: 2726 __this_cpu_dec(bpf_prog_active); 2727 return err; 2728 } 2729 2730 static int 2731 kprobe_multi_link_handler(struct fprobe *fp, unsigned long fentry_ip, 2732 unsigned long ret_ip, struct pt_regs *regs, 2733 void *data) 2734 { 2735 struct bpf_kprobe_multi_link *link; 2736 2737 link = container_of(fp, struct bpf_kprobe_multi_link, fp); 2738 kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), regs); 2739 return 0; 2740 } 2741 2742 static void 2743 kprobe_multi_link_exit_handler(struct fprobe *fp, unsigned long fentry_ip, 2744 unsigned long ret_ip, struct pt_regs *regs, 2745 void *data) 2746 { 2747 struct bpf_kprobe_multi_link *link; 2748 2749 link = container_of(fp, struct bpf_kprobe_multi_link, fp); 2750 kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), regs); 2751 } 2752 2753 static int symbols_cmp_r(const void *a, const void *b, const void *priv) 2754 { 2755 const char **str_a = (const char **) a; 2756 const char **str_b = (const char **) b; 2757 2758 return strcmp(*str_a, *str_b); 2759 } 2760 2761 struct multi_symbols_sort { 2762 const char **funcs; 2763 u64 *cookies; 2764 }; 2765 2766 static void symbols_swap_r(void *a, void *b, int size, const void *priv) 2767 { 2768 const struct multi_symbols_sort *data = priv; 2769 const char **name_a = a, **name_b = b; 2770 2771 swap(*name_a, *name_b); 2772 2773 /* If defined, swap also related cookies. */ 2774 if (data->cookies) { 2775 u64 *cookie_a, *cookie_b; 2776 2777 cookie_a = data->cookies + (name_a - data->funcs); 2778 cookie_b = data->cookies + (name_b - data->funcs); 2779 swap(*cookie_a, *cookie_b); 2780 } 2781 } 2782 2783 struct modules_array { 2784 struct module **mods; 2785 int mods_cnt; 2786 int mods_cap; 2787 }; 2788 2789 static int add_module(struct modules_array *arr, struct module *mod) 2790 { 2791 struct module **mods; 2792 2793 if (arr->mods_cnt == arr->mods_cap) { 2794 arr->mods_cap = max(16, arr->mods_cap * 3 / 2); 2795 mods = krealloc_array(arr->mods, arr->mods_cap, sizeof(*mods), GFP_KERNEL); 2796 if (!mods) 2797 return -ENOMEM; 2798 arr->mods = mods; 2799 } 2800 2801 arr->mods[arr->mods_cnt] = mod; 2802 arr->mods_cnt++; 2803 return 0; 2804 } 2805 2806 static bool has_module(struct modules_array *arr, struct module *mod) 2807 { 2808 int i; 2809 2810 for (i = arr->mods_cnt - 1; i >= 0; i--) { 2811 if (arr->mods[i] == mod) 2812 return true; 2813 } 2814 return false; 2815 } 2816 2817 static int get_modules_for_addrs(struct module ***mods, unsigned long *addrs, u32 addrs_cnt) 2818 { 2819 struct modules_array arr = {}; 2820 u32 i, err = 0; 2821 2822 for (i = 0; i < addrs_cnt; i++) { 2823 struct module *mod; 2824 2825 preempt_disable(); 2826 mod = __module_address(addrs[i]); 2827 /* Either no module or we it's already stored */ 2828 if (!mod || has_module(&arr, mod)) { 2829 preempt_enable(); 2830 continue; 2831 } 2832 if (!try_module_get(mod)) 2833 err = -EINVAL; 2834 preempt_enable(); 2835 if (err) 2836 break; 2837 err = add_module(&arr, mod); 2838 if (err) { 2839 module_put(mod); 2840 break; 2841 } 2842 } 2843 2844 /* We return either err < 0 in case of error, ... */ 2845 if (err) { 2846 kprobe_multi_put_modules(arr.mods, arr.mods_cnt); 2847 kfree(arr.mods); 2848 return err; 2849 } 2850 2851 /* or number of modules found if everything is ok. */ 2852 *mods = arr.mods; 2853 return arr.mods_cnt; 2854 } 2855 2856 static int addrs_check_error_injection_list(unsigned long *addrs, u32 cnt) 2857 { 2858 u32 i; 2859 2860 for (i = 0; i < cnt; i++) { 2861 if (!within_error_injection_list(addrs[i])) 2862 return -EINVAL; 2863 } 2864 return 0; 2865 } 2866 2867 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 2868 { 2869 struct bpf_kprobe_multi_link *link = NULL; 2870 struct bpf_link_primer link_primer; 2871 void __user *ucookies; 2872 unsigned long *addrs; 2873 u32 flags, cnt, size; 2874 void __user *uaddrs; 2875 u64 *cookies = NULL; 2876 void __user *usyms; 2877 int err; 2878 2879 /* no support for 32bit archs yet */ 2880 if (sizeof(u64) != sizeof(void *)) 2881 return -EOPNOTSUPP; 2882 2883 if (prog->expected_attach_type != BPF_TRACE_KPROBE_MULTI) 2884 return -EINVAL; 2885 2886 flags = attr->link_create.kprobe_multi.flags; 2887 if (flags & ~BPF_F_KPROBE_MULTI_RETURN) 2888 return -EINVAL; 2889 2890 uaddrs = u64_to_user_ptr(attr->link_create.kprobe_multi.addrs); 2891 usyms = u64_to_user_ptr(attr->link_create.kprobe_multi.syms); 2892 if (!!uaddrs == !!usyms) 2893 return -EINVAL; 2894 2895 cnt = attr->link_create.kprobe_multi.cnt; 2896 if (!cnt) 2897 return -EINVAL; 2898 2899 size = cnt * sizeof(*addrs); 2900 addrs = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL); 2901 if (!addrs) 2902 return -ENOMEM; 2903 2904 ucookies = u64_to_user_ptr(attr->link_create.kprobe_multi.cookies); 2905 if (ucookies) { 2906 cookies = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL); 2907 if (!cookies) { 2908 err = -ENOMEM; 2909 goto error; 2910 } 2911 if (copy_from_user(cookies, ucookies, size)) { 2912 err = -EFAULT; 2913 goto error; 2914 } 2915 } 2916 2917 if (uaddrs) { 2918 if (copy_from_user(addrs, uaddrs, size)) { 2919 err = -EFAULT; 2920 goto error; 2921 } 2922 } else { 2923 struct multi_symbols_sort data = { 2924 .cookies = cookies, 2925 }; 2926 struct user_syms us; 2927 2928 err = copy_user_syms(&us, usyms, cnt); 2929 if (err) 2930 goto error; 2931 2932 if (cookies) 2933 data.funcs = us.syms; 2934 2935 sort_r(us.syms, cnt, sizeof(*us.syms), symbols_cmp_r, 2936 symbols_swap_r, &data); 2937 2938 err = ftrace_lookup_symbols(us.syms, cnt, addrs); 2939 free_user_syms(&us); 2940 if (err) 2941 goto error; 2942 } 2943 2944 if (prog->kprobe_override && addrs_check_error_injection_list(addrs, cnt)) { 2945 err = -EINVAL; 2946 goto error; 2947 } 2948 2949 link = kzalloc(sizeof(*link), GFP_KERNEL); 2950 if (!link) { 2951 err = -ENOMEM; 2952 goto error; 2953 } 2954 2955 bpf_link_init(&link->link, BPF_LINK_TYPE_KPROBE_MULTI, 2956 &bpf_kprobe_multi_link_lops, prog); 2957 2958 err = bpf_link_prime(&link->link, &link_primer); 2959 if (err) 2960 goto error; 2961 2962 if (flags & BPF_F_KPROBE_MULTI_RETURN) 2963 link->fp.exit_handler = kprobe_multi_link_exit_handler; 2964 else 2965 link->fp.entry_handler = kprobe_multi_link_handler; 2966 2967 link->addrs = addrs; 2968 link->cookies = cookies; 2969 link->cnt = cnt; 2970 link->flags = flags; 2971 2972 if (cookies) { 2973 /* 2974 * Sorting addresses will trigger sorting cookies as well 2975 * (check bpf_kprobe_multi_cookie_swap). This way we can 2976 * find cookie based on the address in bpf_get_attach_cookie 2977 * helper. 2978 */ 2979 sort_r(addrs, cnt, sizeof(*addrs), 2980 bpf_kprobe_multi_cookie_cmp, 2981 bpf_kprobe_multi_cookie_swap, 2982 link); 2983 } 2984 2985 err = get_modules_for_addrs(&link->mods, addrs, cnt); 2986 if (err < 0) { 2987 bpf_link_cleanup(&link_primer); 2988 return err; 2989 } 2990 link->mods_cnt = err; 2991 2992 err = register_fprobe_ips(&link->fp, addrs, cnt); 2993 if (err) { 2994 kprobe_multi_put_modules(link->mods, link->mods_cnt); 2995 bpf_link_cleanup(&link_primer); 2996 return err; 2997 } 2998 2999 return bpf_link_settle(&link_primer); 3000 3001 error: 3002 kfree(link); 3003 kvfree(addrs); 3004 kvfree(cookies); 3005 return err; 3006 } 3007 #else /* !CONFIG_FPROBE */ 3008 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 3009 { 3010 return -EOPNOTSUPP; 3011 } 3012 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx) 3013 { 3014 return 0; 3015 } 3016 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 3017 { 3018 return 0; 3019 } 3020 #endif 3021 3022 #ifdef CONFIG_UPROBES 3023 struct bpf_uprobe_multi_link; 3024 3025 struct bpf_uprobe { 3026 struct bpf_uprobe_multi_link *link; 3027 loff_t offset; 3028 u64 cookie; 3029 struct uprobe_consumer consumer; 3030 }; 3031 3032 struct bpf_uprobe_multi_link { 3033 struct path path; 3034 struct bpf_link link; 3035 u32 cnt; 3036 struct bpf_uprobe *uprobes; 3037 struct task_struct *task; 3038 }; 3039 3040 struct bpf_uprobe_multi_run_ctx { 3041 struct bpf_run_ctx run_ctx; 3042 unsigned long entry_ip; 3043 struct bpf_uprobe *uprobe; 3044 }; 3045 3046 static void bpf_uprobe_unregister(struct path *path, struct bpf_uprobe *uprobes, 3047 u32 cnt) 3048 { 3049 u32 i; 3050 3051 for (i = 0; i < cnt; i++) { 3052 uprobe_unregister(d_real_inode(path->dentry), uprobes[i].offset, 3053 &uprobes[i].consumer); 3054 } 3055 } 3056 3057 static void bpf_uprobe_multi_link_release(struct bpf_link *link) 3058 { 3059 struct bpf_uprobe_multi_link *umulti_link; 3060 3061 umulti_link = container_of(link, struct bpf_uprobe_multi_link, link); 3062 bpf_uprobe_unregister(&umulti_link->path, umulti_link->uprobes, umulti_link->cnt); 3063 } 3064 3065 static void bpf_uprobe_multi_link_dealloc(struct bpf_link *link) 3066 { 3067 struct bpf_uprobe_multi_link *umulti_link; 3068 3069 umulti_link = container_of(link, struct bpf_uprobe_multi_link, link); 3070 if (umulti_link->task) 3071 put_task_struct(umulti_link->task); 3072 path_put(&umulti_link->path); 3073 kvfree(umulti_link->uprobes); 3074 kfree(umulti_link); 3075 } 3076 3077 static const struct bpf_link_ops bpf_uprobe_multi_link_lops = { 3078 .release = bpf_uprobe_multi_link_release, 3079 .dealloc = bpf_uprobe_multi_link_dealloc, 3080 }; 3081 3082 static int uprobe_prog_run(struct bpf_uprobe *uprobe, 3083 unsigned long entry_ip, 3084 struct pt_regs *regs) 3085 { 3086 struct bpf_uprobe_multi_link *link = uprobe->link; 3087 struct bpf_uprobe_multi_run_ctx run_ctx = { 3088 .entry_ip = entry_ip, 3089 .uprobe = uprobe, 3090 }; 3091 struct bpf_prog *prog = link->link.prog; 3092 bool sleepable = prog->aux->sleepable; 3093 struct bpf_run_ctx *old_run_ctx; 3094 int err = 0; 3095 3096 if (link->task && current != link->task) 3097 return 0; 3098 3099 if (sleepable) 3100 rcu_read_lock_trace(); 3101 else 3102 rcu_read_lock(); 3103 3104 migrate_disable(); 3105 3106 old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx); 3107 err = bpf_prog_run(link->link.prog, regs); 3108 bpf_reset_run_ctx(old_run_ctx); 3109 3110 migrate_enable(); 3111 3112 if (sleepable) 3113 rcu_read_unlock_trace(); 3114 else 3115 rcu_read_unlock(); 3116 return err; 3117 } 3118 3119 static bool 3120 uprobe_multi_link_filter(struct uprobe_consumer *con, enum uprobe_filter_ctx ctx, 3121 struct mm_struct *mm) 3122 { 3123 struct bpf_uprobe *uprobe; 3124 3125 uprobe = container_of(con, struct bpf_uprobe, consumer); 3126 return uprobe->link->task->mm == mm; 3127 } 3128 3129 static int 3130 uprobe_multi_link_handler(struct uprobe_consumer *con, struct pt_regs *regs) 3131 { 3132 struct bpf_uprobe *uprobe; 3133 3134 uprobe = container_of(con, struct bpf_uprobe, consumer); 3135 return uprobe_prog_run(uprobe, instruction_pointer(regs), regs); 3136 } 3137 3138 static int 3139 uprobe_multi_link_ret_handler(struct uprobe_consumer *con, unsigned long func, struct pt_regs *regs) 3140 { 3141 struct bpf_uprobe *uprobe; 3142 3143 uprobe = container_of(con, struct bpf_uprobe, consumer); 3144 return uprobe_prog_run(uprobe, func, regs); 3145 } 3146 3147 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 3148 { 3149 struct bpf_uprobe_multi_run_ctx *run_ctx; 3150 3151 run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx, run_ctx); 3152 return run_ctx->entry_ip; 3153 } 3154 3155 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx) 3156 { 3157 struct bpf_uprobe_multi_run_ctx *run_ctx; 3158 3159 run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx, run_ctx); 3160 return run_ctx->uprobe->cookie; 3161 } 3162 3163 int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 3164 { 3165 struct bpf_uprobe_multi_link *link = NULL; 3166 unsigned long __user *uref_ctr_offsets; 3167 unsigned long *ref_ctr_offsets = NULL; 3168 struct bpf_link_primer link_primer; 3169 struct bpf_uprobe *uprobes = NULL; 3170 struct task_struct *task = NULL; 3171 unsigned long __user *uoffsets; 3172 u64 __user *ucookies; 3173 void __user *upath; 3174 u32 flags, cnt, i; 3175 struct path path; 3176 char *name; 3177 pid_t pid; 3178 int err; 3179 3180 /* no support for 32bit archs yet */ 3181 if (sizeof(u64) != sizeof(void *)) 3182 return -EOPNOTSUPP; 3183 3184 if (prog->expected_attach_type != BPF_TRACE_UPROBE_MULTI) 3185 return -EINVAL; 3186 3187 flags = attr->link_create.uprobe_multi.flags; 3188 if (flags & ~BPF_F_UPROBE_MULTI_RETURN) 3189 return -EINVAL; 3190 3191 /* 3192 * path, offsets and cnt are mandatory, 3193 * ref_ctr_offsets and cookies are optional 3194 */ 3195 upath = u64_to_user_ptr(attr->link_create.uprobe_multi.path); 3196 uoffsets = u64_to_user_ptr(attr->link_create.uprobe_multi.offsets); 3197 cnt = attr->link_create.uprobe_multi.cnt; 3198 3199 if (!upath || !uoffsets || !cnt) 3200 return -EINVAL; 3201 3202 uref_ctr_offsets = u64_to_user_ptr(attr->link_create.uprobe_multi.ref_ctr_offsets); 3203 ucookies = u64_to_user_ptr(attr->link_create.uprobe_multi.cookies); 3204 3205 name = strndup_user(upath, PATH_MAX); 3206 if (IS_ERR(name)) { 3207 err = PTR_ERR(name); 3208 return err; 3209 } 3210 3211 err = kern_path(name, LOOKUP_FOLLOW, &path); 3212 kfree(name); 3213 if (err) 3214 return err; 3215 3216 if (!d_is_reg(path.dentry)) { 3217 err = -EBADF; 3218 goto error_path_put; 3219 } 3220 3221 pid = attr->link_create.uprobe_multi.pid; 3222 if (pid) { 3223 rcu_read_lock(); 3224 task = get_pid_task(find_vpid(pid), PIDTYPE_PID); 3225 rcu_read_unlock(); 3226 if (!task) { 3227 err = -ESRCH; 3228 goto error_path_put; 3229 } 3230 } 3231 3232 err = -ENOMEM; 3233 3234 link = kzalloc(sizeof(*link), GFP_KERNEL); 3235 uprobes = kvcalloc(cnt, sizeof(*uprobes), GFP_KERNEL); 3236 3237 if (!uprobes || !link) 3238 goto error_free; 3239 3240 if (uref_ctr_offsets) { 3241 ref_ctr_offsets = kvcalloc(cnt, sizeof(*ref_ctr_offsets), GFP_KERNEL); 3242 if (!ref_ctr_offsets) 3243 goto error_free; 3244 } 3245 3246 for (i = 0; i < cnt; i++) { 3247 if (ucookies && __get_user(uprobes[i].cookie, ucookies + i)) { 3248 err = -EFAULT; 3249 goto error_free; 3250 } 3251 if (uref_ctr_offsets && __get_user(ref_ctr_offsets[i], uref_ctr_offsets + i)) { 3252 err = -EFAULT; 3253 goto error_free; 3254 } 3255 if (__get_user(uprobes[i].offset, uoffsets + i)) { 3256 err = -EFAULT; 3257 goto error_free; 3258 } 3259 3260 uprobes[i].link = link; 3261 3262 if (flags & BPF_F_UPROBE_MULTI_RETURN) 3263 uprobes[i].consumer.ret_handler = uprobe_multi_link_ret_handler; 3264 else 3265 uprobes[i].consumer.handler = uprobe_multi_link_handler; 3266 3267 if (pid) 3268 uprobes[i].consumer.filter = uprobe_multi_link_filter; 3269 } 3270 3271 link->cnt = cnt; 3272 link->uprobes = uprobes; 3273 link->path = path; 3274 link->task = task; 3275 3276 bpf_link_init(&link->link, BPF_LINK_TYPE_UPROBE_MULTI, 3277 &bpf_uprobe_multi_link_lops, prog); 3278 3279 for (i = 0; i < cnt; i++) { 3280 err = uprobe_register_refctr(d_real_inode(link->path.dentry), 3281 uprobes[i].offset, 3282 ref_ctr_offsets ? ref_ctr_offsets[i] : 0, 3283 &uprobes[i].consumer); 3284 if (err) { 3285 bpf_uprobe_unregister(&path, uprobes, i); 3286 goto error_free; 3287 } 3288 } 3289 3290 err = bpf_link_prime(&link->link, &link_primer); 3291 if (err) 3292 goto error_free; 3293 3294 kvfree(ref_ctr_offsets); 3295 return bpf_link_settle(&link_primer); 3296 3297 error_free: 3298 kvfree(ref_ctr_offsets); 3299 kvfree(uprobes); 3300 kfree(link); 3301 if (task) 3302 put_task_struct(task); 3303 error_path_put: 3304 path_put(&path); 3305 return err; 3306 } 3307 #else /* !CONFIG_UPROBES */ 3308 int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 3309 { 3310 return -EOPNOTSUPP; 3311 } 3312 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx) 3313 { 3314 return 0; 3315 } 3316 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 3317 { 3318 return 0; 3319 } 3320 #endif /* CONFIG_UPROBES */ 3321