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 #include <linux/fileattr.h> 28 29 #include <net/bpf_sk_storage.h> 30 31 #include <uapi/linux/bpf.h> 32 #include <uapi/linux/btf.h> 33 34 #include <asm/tlb.h> 35 36 #include "trace_probe.h" 37 #include "trace.h" 38 39 #define CREATE_TRACE_POINTS 40 #include "bpf_trace.h" 41 42 #define bpf_event_rcu_dereference(p) \ 43 rcu_dereference_protected(p, lockdep_is_held(&bpf_event_mutex)) 44 45 #define MAX_UPROBE_MULTI_CNT (1U << 20) 46 #define MAX_KPROBE_MULTI_CNT (1U << 20) 47 48 #ifdef CONFIG_MODULES 49 struct bpf_trace_module { 50 struct module *module; 51 struct list_head list; 52 }; 53 54 static LIST_HEAD(bpf_trace_modules); 55 static DEFINE_MUTEX(bpf_module_mutex); 56 57 static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name) 58 { 59 struct bpf_raw_event_map *btp, *ret = NULL; 60 struct bpf_trace_module *btm; 61 unsigned int i; 62 63 mutex_lock(&bpf_module_mutex); 64 list_for_each_entry(btm, &bpf_trace_modules, list) { 65 for (i = 0; i < btm->module->num_bpf_raw_events; ++i) { 66 btp = &btm->module->bpf_raw_events[i]; 67 if (!strcmp(btp->tp->name, name)) { 68 if (try_module_get(btm->module)) 69 ret = btp; 70 goto out; 71 } 72 } 73 } 74 out: 75 mutex_unlock(&bpf_module_mutex); 76 return ret; 77 } 78 #else 79 static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name) 80 { 81 return NULL; 82 } 83 #endif /* CONFIG_MODULES */ 84 85 u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); 86 u64 bpf_get_stack(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); 87 88 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size, 89 u64 flags, const struct btf **btf, 90 s32 *btf_id); 91 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx); 92 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx); 93 94 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx); 95 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx); 96 97 /** 98 * trace_call_bpf - invoke BPF program 99 * @call: tracepoint event 100 * @ctx: opaque context pointer 101 * 102 * kprobe handlers execute BPF programs via this helper. 103 * Can be used from static tracepoints in the future. 104 * 105 * Return: BPF programs always return an integer which is interpreted by 106 * kprobe handler as: 107 * 0 - return from kprobe (event is filtered out) 108 * 1 - store kprobe event into ring buffer 109 * Other values are reserved and currently alias to 1 110 */ 111 unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx) 112 { 113 unsigned int ret; 114 115 cant_sleep(); 116 117 if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) { 118 /* 119 * since some bpf program is already running on this cpu, 120 * don't call into another bpf program (same or different) 121 * and don't send kprobe event into ring-buffer, 122 * so return zero here 123 */ 124 rcu_read_lock(); 125 bpf_prog_inc_misses_counters(rcu_dereference(call->prog_array)); 126 rcu_read_unlock(); 127 ret = 0; 128 goto out; 129 } 130 131 /* 132 * Instead of moving rcu_read_lock/rcu_dereference/rcu_read_unlock 133 * to all call sites, we did a bpf_prog_array_valid() there to check 134 * whether call->prog_array is empty or not, which is 135 * a heuristic to speed up execution. 136 * 137 * If bpf_prog_array_valid() fetched prog_array was 138 * non-NULL, we go into trace_call_bpf() and do the actual 139 * proper rcu_dereference() under RCU lock. 140 * If it turns out that prog_array is NULL then, we bail out. 141 * For the opposite, if the bpf_prog_array_valid() fetched pointer 142 * was NULL, you'll skip the prog_array with the risk of missing 143 * out of events when it was updated in between this and the 144 * rcu_dereference() which is accepted risk. 145 */ 146 rcu_read_lock(); 147 ret = bpf_prog_run_array(rcu_dereference(call->prog_array), 148 ctx, bpf_prog_run); 149 rcu_read_unlock(); 150 151 out: 152 __this_cpu_dec(bpf_prog_active); 153 154 return ret; 155 } 156 157 #ifdef CONFIG_BPF_KPROBE_OVERRIDE 158 BPF_CALL_2(bpf_override_return, struct pt_regs *, regs, unsigned long, rc) 159 { 160 regs_set_return_value(regs, rc); 161 override_function_with_return(regs); 162 return 0; 163 } 164 165 static const struct bpf_func_proto bpf_override_return_proto = { 166 .func = bpf_override_return, 167 .gpl_only = true, 168 .ret_type = RET_INTEGER, 169 .arg1_type = ARG_PTR_TO_CTX, 170 .arg2_type = ARG_ANYTHING, 171 }; 172 #endif 173 174 static __always_inline int 175 bpf_probe_read_user_common(void *dst, u32 size, const void __user *unsafe_ptr) 176 { 177 int ret; 178 179 ret = copy_from_user_nofault(dst, unsafe_ptr, size); 180 if (unlikely(ret < 0)) 181 memset(dst, 0, size); 182 return ret; 183 } 184 185 BPF_CALL_3(bpf_probe_read_user, void *, dst, u32, size, 186 const void __user *, unsafe_ptr) 187 { 188 return bpf_probe_read_user_common(dst, size, unsafe_ptr); 189 } 190 191 const struct bpf_func_proto bpf_probe_read_user_proto = { 192 .func = bpf_probe_read_user, 193 .gpl_only = true, 194 .ret_type = RET_INTEGER, 195 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 196 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 197 .arg3_type = ARG_ANYTHING, 198 }; 199 200 static __always_inline int 201 bpf_probe_read_user_str_common(void *dst, u32 size, 202 const void __user *unsafe_ptr) 203 { 204 int ret; 205 206 /* 207 * NB: We rely on strncpy_from_user() not copying junk past the NUL 208 * terminator into `dst`. 209 * 210 * strncpy_from_user() does long-sized strides in the fast path. If the 211 * strncpy does not mask out the bytes after the NUL in `unsafe_ptr`, 212 * then there could be junk after the NUL in `dst`. If user takes `dst` 213 * and keys a hash map with it, then semantically identical strings can 214 * occupy multiple entries in the map. 215 */ 216 ret = strncpy_from_user_nofault(dst, unsafe_ptr, size); 217 if (unlikely(ret < 0)) 218 memset(dst, 0, size); 219 return ret; 220 } 221 222 BPF_CALL_3(bpf_probe_read_user_str, void *, dst, u32, size, 223 const void __user *, unsafe_ptr) 224 { 225 return bpf_probe_read_user_str_common(dst, size, unsafe_ptr); 226 } 227 228 const struct bpf_func_proto bpf_probe_read_user_str_proto = { 229 .func = bpf_probe_read_user_str, 230 .gpl_only = true, 231 .ret_type = RET_INTEGER, 232 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 233 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 234 .arg3_type = ARG_ANYTHING, 235 }; 236 237 BPF_CALL_3(bpf_probe_read_kernel, void *, dst, u32, size, 238 const void *, unsafe_ptr) 239 { 240 return bpf_probe_read_kernel_common(dst, size, unsafe_ptr); 241 } 242 243 const struct bpf_func_proto bpf_probe_read_kernel_proto = { 244 .func = bpf_probe_read_kernel, 245 .gpl_only = true, 246 .ret_type = RET_INTEGER, 247 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 248 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 249 .arg3_type = ARG_ANYTHING, 250 }; 251 252 static __always_inline int 253 bpf_probe_read_kernel_str_common(void *dst, u32 size, const void *unsafe_ptr) 254 { 255 int ret; 256 257 /* 258 * The strncpy_from_kernel_nofault() call will likely not fill the 259 * entire buffer, but that's okay in this circumstance as we're probing 260 * arbitrary memory anyway similar to bpf_probe_read_*() and might 261 * as well probe the stack. Thus, memory is explicitly cleared 262 * only in error case, so that improper users ignoring return 263 * code altogether don't copy garbage; otherwise length of string 264 * is returned that can be used for bpf_perf_event_output() et al. 265 */ 266 ret = strncpy_from_kernel_nofault(dst, unsafe_ptr, size); 267 if (unlikely(ret < 0)) 268 memset(dst, 0, size); 269 return ret; 270 } 271 272 BPF_CALL_3(bpf_probe_read_kernel_str, void *, dst, u32, size, 273 const void *, unsafe_ptr) 274 { 275 return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr); 276 } 277 278 const struct bpf_func_proto bpf_probe_read_kernel_str_proto = { 279 .func = bpf_probe_read_kernel_str, 280 .gpl_only = true, 281 .ret_type = RET_INTEGER, 282 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 283 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 284 .arg3_type = ARG_ANYTHING, 285 }; 286 287 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 288 BPF_CALL_3(bpf_probe_read_compat, void *, dst, u32, size, 289 const void *, unsafe_ptr) 290 { 291 if ((unsigned long)unsafe_ptr < TASK_SIZE) { 292 return bpf_probe_read_user_common(dst, size, 293 (__force void __user *)unsafe_ptr); 294 } 295 return bpf_probe_read_kernel_common(dst, size, unsafe_ptr); 296 } 297 298 static const struct bpf_func_proto bpf_probe_read_compat_proto = { 299 .func = bpf_probe_read_compat, 300 .gpl_only = true, 301 .ret_type = RET_INTEGER, 302 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 303 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 304 .arg3_type = ARG_ANYTHING, 305 }; 306 307 BPF_CALL_3(bpf_probe_read_compat_str, void *, dst, u32, size, 308 const void *, unsafe_ptr) 309 { 310 if ((unsigned long)unsafe_ptr < TASK_SIZE) { 311 return bpf_probe_read_user_str_common(dst, size, 312 (__force void __user *)unsafe_ptr); 313 } 314 return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr); 315 } 316 317 static const struct bpf_func_proto bpf_probe_read_compat_str_proto = { 318 .func = bpf_probe_read_compat_str, 319 .gpl_only = true, 320 .ret_type = RET_INTEGER, 321 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 322 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 323 .arg3_type = ARG_ANYTHING, 324 }; 325 #endif /* CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE */ 326 327 BPF_CALL_3(bpf_probe_write_user, void __user *, unsafe_ptr, const void *, src, 328 u32, size) 329 { 330 /* 331 * Ensure we're in user context which is safe for the helper to 332 * run. This helper has no business in a kthread. 333 * 334 * access_ok() should prevent writing to non-user memory, but in 335 * some situations (nommu, temporary switch, etc) access_ok() does 336 * not provide enough validation, hence the check on KERNEL_DS. 337 * 338 * nmi_uaccess_okay() ensures the probe is not run in an interim 339 * state, when the task or mm are switched. This is specifically 340 * required to prevent the use of temporary mm. 341 */ 342 343 if (unlikely(in_interrupt() || 344 current->flags & (PF_KTHREAD | PF_EXITING))) 345 return -EPERM; 346 if (unlikely(!nmi_uaccess_okay())) 347 return -EPERM; 348 349 return copy_to_user_nofault(unsafe_ptr, src, size); 350 } 351 352 static const struct bpf_func_proto bpf_probe_write_user_proto = { 353 .func = bpf_probe_write_user, 354 .gpl_only = true, 355 .ret_type = RET_INTEGER, 356 .arg1_type = ARG_ANYTHING, 357 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 358 .arg3_type = ARG_CONST_SIZE, 359 }; 360 361 static const struct bpf_func_proto *bpf_get_probe_write_proto(void) 362 { 363 if (!capable(CAP_SYS_ADMIN)) 364 return NULL; 365 366 pr_warn_ratelimited("%s[%d] is installing a program with bpf_probe_write_user helper that may corrupt user memory!", 367 current->comm, task_pid_nr(current)); 368 369 return &bpf_probe_write_user_proto; 370 } 371 372 #define MAX_TRACE_PRINTK_VARARGS 3 373 #define BPF_TRACE_PRINTK_SIZE 1024 374 375 BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1, 376 u64, arg2, u64, arg3) 377 { 378 u64 args[MAX_TRACE_PRINTK_VARARGS] = { arg1, arg2, arg3 }; 379 struct bpf_bprintf_data data = { 380 .get_bin_args = true, 381 .get_buf = true, 382 }; 383 int ret; 384 385 ret = bpf_bprintf_prepare(fmt, fmt_size, args, 386 MAX_TRACE_PRINTK_VARARGS, &data); 387 if (ret < 0) 388 return ret; 389 390 ret = bstr_printf(data.buf, MAX_BPRINTF_BUF, fmt, data.bin_args); 391 392 trace_bpf_trace_printk(data.buf); 393 394 bpf_bprintf_cleanup(&data); 395 396 return ret; 397 } 398 399 static const struct bpf_func_proto bpf_trace_printk_proto = { 400 .func = bpf_trace_printk, 401 .gpl_only = true, 402 .ret_type = RET_INTEGER, 403 .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY, 404 .arg2_type = ARG_CONST_SIZE, 405 }; 406 407 static void __set_printk_clr_event(void) 408 { 409 /* 410 * This program might be calling bpf_trace_printk, 411 * so enable the associated bpf_trace/bpf_trace_printk event. 412 * Repeat this each time as it is possible a user has 413 * disabled bpf_trace_printk events. By loading a program 414 * calling bpf_trace_printk() however the user has expressed 415 * the intent to see such events. 416 */ 417 if (trace_set_clr_event("bpf_trace", "bpf_trace_printk", 1)) 418 pr_warn_ratelimited("could not enable bpf_trace_printk events"); 419 } 420 421 const struct bpf_func_proto *bpf_get_trace_printk_proto(void) 422 { 423 __set_printk_clr_event(); 424 return &bpf_trace_printk_proto; 425 } 426 427 BPF_CALL_4(bpf_trace_vprintk, char *, fmt, u32, fmt_size, const void *, args, 428 u32, data_len) 429 { 430 struct bpf_bprintf_data data = { 431 .get_bin_args = true, 432 .get_buf = true, 433 }; 434 int ret, num_args; 435 436 if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 || 437 (data_len && !args)) 438 return -EINVAL; 439 num_args = data_len / 8; 440 441 ret = bpf_bprintf_prepare(fmt, fmt_size, args, num_args, &data); 442 if (ret < 0) 443 return ret; 444 445 ret = bstr_printf(data.buf, MAX_BPRINTF_BUF, fmt, data.bin_args); 446 447 trace_bpf_trace_printk(data.buf); 448 449 bpf_bprintf_cleanup(&data); 450 451 return ret; 452 } 453 454 static const struct bpf_func_proto bpf_trace_vprintk_proto = { 455 .func = bpf_trace_vprintk, 456 .gpl_only = true, 457 .ret_type = RET_INTEGER, 458 .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY, 459 .arg2_type = ARG_CONST_SIZE, 460 .arg3_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY, 461 .arg4_type = ARG_CONST_SIZE_OR_ZERO, 462 }; 463 464 const struct bpf_func_proto *bpf_get_trace_vprintk_proto(void) 465 { 466 __set_printk_clr_event(); 467 return &bpf_trace_vprintk_proto; 468 } 469 470 BPF_CALL_5(bpf_seq_printf, struct seq_file *, m, char *, fmt, u32, fmt_size, 471 const void *, args, u32, data_len) 472 { 473 struct bpf_bprintf_data data = { 474 .get_bin_args = true, 475 }; 476 int err, num_args; 477 478 if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 || 479 (data_len && !args)) 480 return -EINVAL; 481 num_args = data_len / 8; 482 483 err = bpf_bprintf_prepare(fmt, fmt_size, args, num_args, &data); 484 if (err < 0) 485 return err; 486 487 seq_bprintf(m, fmt, data.bin_args); 488 489 bpf_bprintf_cleanup(&data); 490 491 return seq_has_overflowed(m) ? -EOVERFLOW : 0; 492 } 493 494 BTF_ID_LIST_SINGLE(btf_seq_file_ids, struct, seq_file) 495 496 static const struct bpf_func_proto bpf_seq_printf_proto = { 497 .func = bpf_seq_printf, 498 .gpl_only = true, 499 .ret_type = RET_INTEGER, 500 .arg1_type = ARG_PTR_TO_BTF_ID, 501 .arg1_btf_id = &btf_seq_file_ids[0], 502 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 503 .arg3_type = ARG_CONST_SIZE, 504 .arg4_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY, 505 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 506 }; 507 508 BPF_CALL_3(bpf_seq_write, struct seq_file *, m, const void *, data, u32, len) 509 { 510 return seq_write(m, data, len) ? -EOVERFLOW : 0; 511 } 512 513 static const struct bpf_func_proto bpf_seq_write_proto = { 514 .func = bpf_seq_write, 515 .gpl_only = true, 516 .ret_type = RET_INTEGER, 517 .arg1_type = ARG_PTR_TO_BTF_ID, 518 .arg1_btf_id = &btf_seq_file_ids[0], 519 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 520 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 521 }; 522 523 BPF_CALL_4(bpf_seq_printf_btf, struct seq_file *, m, struct btf_ptr *, ptr, 524 u32, btf_ptr_size, u64, flags) 525 { 526 const struct btf *btf; 527 s32 btf_id; 528 int ret; 529 530 ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id); 531 if (ret) 532 return ret; 533 534 return btf_type_seq_show_flags(btf, btf_id, ptr->ptr, m, flags); 535 } 536 537 static const struct bpf_func_proto bpf_seq_printf_btf_proto = { 538 .func = bpf_seq_printf_btf, 539 .gpl_only = true, 540 .ret_type = RET_INTEGER, 541 .arg1_type = ARG_PTR_TO_BTF_ID, 542 .arg1_btf_id = &btf_seq_file_ids[0], 543 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 544 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 545 .arg4_type = ARG_ANYTHING, 546 }; 547 548 static __always_inline int 549 get_map_perf_counter(struct bpf_map *map, u64 flags, 550 u64 *value, u64 *enabled, u64 *running) 551 { 552 struct bpf_array *array = container_of(map, struct bpf_array, map); 553 unsigned int cpu = smp_processor_id(); 554 u64 index = flags & BPF_F_INDEX_MASK; 555 struct bpf_event_entry *ee; 556 557 if (unlikely(flags & ~(BPF_F_INDEX_MASK))) 558 return -EINVAL; 559 if (index == BPF_F_CURRENT_CPU) 560 index = cpu; 561 if (unlikely(index >= array->map.max_entries)) 562 return -E2BIG; 563 564 ee = READ_ONCE(array->ptrs[index]); 565 if (!ee) 566 return -ENOENT; 567 568 return perf_event_read_local(ee->event, value, enabled, running); 569 } 570 571 BPF_CALL_2(bpf_perf_event_read, struct bpf_map *, map, u64, flags) 572 { 573 u64 value = 0; 574 int err; 575 576 err = get_map_perf_counter(map, flags, &value, NULL, NULL); 577 /* 578 * this api is ugly since we miss [-22..-2] range of valid 579 * counter values, but that's uapi 580 */ 581 if (err) 582 return err; 583 return value; 584 } 585 586 static const struct bpf_func_proto bpf_perf_event_read_proto = { 587 .func = bpf_perf_event_read, 588 .gpl_only = true, 589 .ret_type = RET_INTEGER, 590 .arg1_type = ARG_CONST_MAP_PTR, 591 .arg2_type = ARG_ANYTHING, 592 }; 593 594 BPF_CALL_4(bpf_perf_event_read_value, struct bpf_map *, map, u64, flags, 595 struct bpf_perf_event_value *, buf, u32, size) 596 { 597 int err = -EINVAL; 598 599 if (unlikely(size != sizeof(struct bpf_perf_event_value))) 600 goto clear; 601 err = get_map_perf_counter(map, flags, &buf->counter, &buf->enabled, 602 &buf->running); 603 if (unlikely(err)) 604 goto clear; 605 return 0; 606 clear: 607 memset(buf, 0, size); 608 return err; 609 } 610 611 static const struct bpf_func_proto bpf_perf_event_read_value_proto = { 612 .func = bpf_perf_event_read_value, 613 .gpl_only = true, 614 .ret_type = RET_INTEGER, 615 .arg1_type = ARG_CONST_MAP_PTR, 616 .arg2_type = ARG_ANYTHING, 617 .arg3_type = ARG_PTR_TO_UNINIT_MEM, 618 .arg4_type = ARG_CONST_SIZE, 619 }; 620 621 static __always_inline u64 622 __bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map, 623 u64 flags, struct perf_sample_data *sd) 624 { 625 struct bpf_array *array = container_of(map, struct bpf_array, map); 626 unsigned int cpu = smp_processor_id(); 627 u64 index = flags & BPF_F_INDEX_MASK; 628 struct bpf_event_entry *ee; 629 struct perf_event *event; 630 631 if (index == BPF_F_CURRENT_CPU) 632 index = cpu; 633 if (unlikely(index >= array->map.max_entries)) 634 return -E2BIG; 635 636 ee = READ_ONCE(array->ptrs[index]); 637 if (!ee) 638 return -ENOENT; 639 640 event = ee->event; 641 if (unlikely(event->attr.type != PERF_TYPE_SOFTWARE || 642 event->attr.config != PERF_COUNT_SW_BPF_OUTPUT)) 643 return -EINVAL; 644 645 if (unlikely(event->oncpu != cpu)) 646 return -EOPNOTSUPP; 647 648 return perf_event_output(event, sd, regs); 649 } 650 651 /* 652 * Support executing tracepoints in normal, irq, and nmi context that each call 653 * bpf_perf_event_output 654 */ 655 struct bpf_trace_sample_data { 656 struct perf_sample_data sds[3]; 657 }; 658 659 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_trace_sds); 660 static DEFINE_PER_CPU(int, bpf_trace_nest_level); 661 BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map, 662 u64, flags, void *, data, u64, size) 663 { 664 struct bpf_trace_sample_data *sds; 665 struct perf_raw_record raw = { 666 .frag = { 667 .size = size, 668 .data = data, 669 }, 670 }; 671 struct perf_sample_data *sd; 672 int nest_level, err; 673 674 preempt_disable(); 675 sds = this_cpu_ptr(&bpf_trace_sds); 676 nest_level = this_cpu_inc_return(bpf_trace_nest_level); 677 678 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(sds->sds))) { 679 err = -EBUSY; 680 goto out; 681 } 682 683 sd = &sds->sds[nest_level - 1]; 684 685 if (unlikely(flags & ~(BPF_F_INDEX_MASK))) { 686 err = -EINVAL; 687 goto out; 688 } 689 690 perf_sample_data_init(sd, 0, 0); 691 perf_sample_save_raw_data(sd, &raw); 692 693 err = __bpf_perf_event_output(regs, map, flags, sd); 694 out: 695 this_cpu_dec(bpf_trace_nest_level); 696 preempt_enable(); 697 return err; 698 } 699 700 static const struct bpf_func_proto bpf_perf_event_output_proto = { 701 .func = bpf_perf_event_output, 702 .gpl_only = true, 703 .ret_type = RET_INTEGER, 704 .arg1_type = ARG_PTR_TO_CTX, 705 .arg2_type = ARG_CONST_MAP_PTR, 706 .arg3_type = ARG_ANYTHING, 707 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, 708 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 709 }; 710 711 static DEFINE_PER_CPU(int, bpf_event_output_nest_level); 712 struct bpf_nested_pt_regs { 713 struct pt_regs regs[3]; 714 }; 715 static DEFINE_PER_CPU(struct bpf_nested_pt_regs, bpf_pt_regs); 716 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_misc_sds); 717 718 u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size, 719 void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy) 720 { 721 struct perf_raw_frag frag = { 722 .copy = ctx_copy, 723 .size = ctx_size, 724 .data = ctx, 725 }; 726 struct perf_raw_record raw = { 727 .frag = { 728 { 729 .next = ctx_size ? &frag : NULL, 730 }, 731 .size = meta_size, 732 .data = meta, 733 }, 734 }; 735 struct perf_sample_data *sd; 736 struct pt_regs *regs; 737 int nest_level; 738 u64 ret; 739 740 preempt_disable(); 741 nest_level = this_cpu_inc_return(bpf_event_output_nest_level); 742 743 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(bpf_misc_sds.sds))) { 744 ret = -EBUSY; 745 goto out; 746 } 747 sd = this_cpu_ptr(&bpf_misc_sds.sds[nest_level - 1]); 748 regs = this_cpu_ptr(&bpf_pt_regs.regs[nest_level - 1]); 749 750 perf_fetch_caller_regs(regs); 751 perf_sample_data_init(sd, 0, 0); 752 perf_sample_save_raw_data(sd, &raw); 753 754 ret = __bpf_perf_event_output(regs, map, flags, sd); 755 out: 756 this_cpu_dec(bpf_event_output_nest_level); 757 preempt_enable(); 758 return ret; 759 } 760 761 BPF_CALL_0(bpf_get_current_task) 762 { 763 return (long) current; 764 } 765 766 const struct bpf_func_proto bpf_get_current_task_proto = { 767 .func = bpf_get_current_task, 768 .gpl_only = true, 769 .ret_type = RET_INTEGER, 770 }; 771 772 BPF_CALL_0(bpf_get_current_task_btf) 773 { 774 return (unsigned long) current; 775 } 776 777 const struct bpf_func_proto bpf_get_current_task_btf_proto = { 778 .func = bpf_get_current_task_btf, 779 .gpl_only = true, 780 .ret_type = RET_PTR_TO_BTF_ID_TRUSTED, 781 .ret_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK], 782 }; 783 784 BPF_CALL_1(bpf_task_pt_regs, struct task_struct *, task) 785 { 786 return (unsigned long) task_pt_regs(task); 787 } 788 789 BTF_ID_LIST(bpf_task_pt_regs_ids) 790 BTF_ID(struct, pt_regs) 791 792 const struct bpf_func_proto bpf_task_pt_regs_proto = { 793 .func = bpf_task_pt_regs, 794 .gpl_only = true, 795 .arg1_type = ARG_PTR_TO_BTF_ID, 796 .arg1_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK], 797 .ret_type = RET_PTR_TO_BTF_ID, 798 .ret_btf_id = &bpf_task_pt_regs_ids[0], 799 }; 800 801 BPF_CALL_2(bpf_current_task_under_cgroup, struct bpf_map *, map, u32, idx) 802 { 803 struct bpf_array *array = container_of(map, struct bpf_array, map); 804 struct cgroup *cgrp; 805 806 if (unlikely(idx >= array->map.max_entries)) 807 return -E2BIG; 808 809 cgrp = READ_ONCE(array->ptrs[idx]); 810 if (unlikely(!cgrp)) 811 return -EAGAIN; 812 813 return task_under_cgroup_hierarchy(current, cgrp); 814 } 815 816 static const struct bpf_func_proto bpf_current_task_under_cgroup_proto = { 817 .func = bpf_current_task_under_cgroup, 818 .gpl_only = false, 819 .ret_type = RET_INTEGER, 820 .arg1_type = ARG_CONST_MAP_PTR, 821 .arg2_type = ARG_ANYTHING, 822 }; 823 824 struct send_signal_irq_work { 825 struct irq_work irq_work; 826 struct task_struct *task; 827 u32 sig; 828 enum pid_type type; 829 }; 830 831 static DEFINE_PER_CPU(struct send_signal_irq_work, send_signal_work); 832 833 static void do_bpf_send_signal(struct irq_work *entry) 834 { 835 struct send_signal_irq_work *work; 836 837 work = container_of(entry, struct send_signal_irq_work, irq_work); 838 group_send_sig_info(work->sig, SEND_SIG_PRIV, work->task, work->type); 839 put_task_struct(work->task); 840 } 841 842 static int bpf_send_signal_common(u32 sig, enum pid_type type) 843 { 844 struct send_signal_irq_work *work = NULL; 845 846 /* Similar to bpf_probe_write_user, task needs to be 847 * in a sound condition and kernel memory access be 848 * permitted in order to send signal to the current 849 * task. 850 */ 851 if (unlikely(current->flags & (PF_KTHREAD | PF_EXITING))) 852 return -EPERM; 853 if (unlikely(!nmi_uaccess_okay())) 854 return -EPERM; 855 /* Task should not be pid=1 to avoid kernel panic. */ 856 if (unlikely(is_global_init(current))) 857 return -EPERM; 858 859 if (irqs_disabled()) { 860 /* Do an early check on signal validity. Otherwise, 861 * the error is lost in deferred irq_work. 862 */ 863 if (unlikely(!valid_signal(sig))) 864 return -EINVAL; 865 866 work = this_cpu_ptr(&send_signal_work); 867 if (irq_work_is_busy(&work->irq_work)) 868 return -EBUSY; 869 870 /* Add the current task, which is the target of sending signal, 871 * to the irq_work. The current task may change when queued 872 * irq works get executed. 873 */ 874 work->task = get_task_struct(current); 875 work->sig = sig; 876 work->type = type; 877 irq_work_queue(&work->irq_work); 878 return 0; 879 } 880 881 return group_send_sig_info(sig, SEND_SIG_PRIV, current, type); 882 } 883 884 BPF_CALL_1(bpf_send_signal, u32, sig) 885 { 886 return bpf_send_signal_common(sig, PIDTYPE_TGID); 887 } 888 889 static const struct bpf_func_proto bpf_send_signal_proto = { 890 .func = bpf_send_signal, 891 .gpl_only = false, 892 .ret_type = RET_INTEGER, 893 .arg1_type = ARG_ANYTHING, 894 }; 895 896 BPF_CALL_1(bpf_send_signal_thread, u32, sig) 897 { 898 return bpf_send_signal_common(sig, PIDTYPE_PID); 899 } 900 901 static const struct bpf_func_proto bpf_send_signal_thread_proto = { 902 .func = bpf_send_signal_thread, 903 .gpl_only = false, 904 .ret_type = RET_INTEGER, 905 .arg1_type = ARG_ANYTHING, 906 }; 907 908 BPF_CALL_3(bpf_d_path, struct path *, path, char *, buf, u32, sz) 909 { 910 struct path copy; 911 long len; 912 char *p; 913 914 if (!sz) 915 return 0; 916 917 /* 918 * The path pointer is verified as trusted and safe to use, 919 * but let's double check it's valid anyway to workaround 920 * potentially broken verifier. 921 */ 922 len = copy_from_kernel_nofault(©, path, sizeof(*path)); 923 if (len < 0) 924 return len; 925 926 p = d_path(©, buf, sz); 927 if (IS_ERR(p)) { 928 len = PTR_ERR(p); 929 } else { 930 len = buf + sz - p; 931 memmove(buf, p, len); 932 } 933 934 return len; 935 } 936 937 BTF_SET_START(btf_allowlist_d_path) 938 #ifdef CONFIG_SECURITY 939 BTF_ID(func, security_file_permission) 940 BTF_ID(func, security_inode_getattr) 941 BTF_ID(func, security_file_open) 942 #endif 943 #ifdef CONFIG_SECURITY_PATH 944 BTF_ID(func, security_path_truncate) 945 #endif 946 BTF_ID(func, vfs_truncate) 947 BTF_ID(func, vfs_fallocate) 948 BTF_ID(func, dentry_open) 949 BTF_ID(func, vfs_getattr) 950 BTF_ID(func, filp_close) 951 BTF_SET_END(btf_allowlist_d_path) 952 953 static bool bpf_d_path_allowed(const struct bpf_prog *prog) 954 { 955 if (prog->type == BPF_PROG_TYPE_TRACING && 956 prog->expected_attach_type == BPF_TRACE_ITER) 957 return true; 958 959 if (prog->type == BPF_PROG_TYPE_LSM) 960 return bpf_lsm_is_sleepable_hook(prog->aux->attach_btf_id); 961 962 return btf_id_set_contains(&btf_allowlist_d_path, 963 prog->aux->attach_btf_id); 964 } 965 966 BTF_ID_LIST_SINGLE(bpf_d_path_btf_ids, struct, path) 967 968 static const struct bpf_func_proto bpf_d_path_proto = { 969 .func = bpf_d_path, 970 .gpl_only = false, 971 .ret_type = RET_INTEGER, 972 .arg1_type = ARG_PTR_TO_BTF_ID, 973 .arg1_btf_id = &bpf_d_path_btf_ids[0], 974 .arg2_type = ARG_PTR_TO_MEM, 975 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 976 .allowed = bpf_d_path_allowed, 977 }; 978 979 #define BTF_F_ALL (BTF_F_COMPACT | BTF_F_NONAME | \ 980 BTF_F_PTR_RAW | BTF_F_ZERO) 981 982 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size, 983 u64 flags, const struct btf **btf, 984 s32 *btf_id) 985 { 986 const struct btf_type *t; 987 988 if (unlikely(flags & ~(BTF_F_ALL))) 989 return -EINVAL; 990 991 if (btf_ptr_size != sizeof(struct btf_ptr)) 992 return -EINVAL; 993 994 *btf = bpf_get_btf_vmlinux(); 995 996 if (IS_ERR_OR_NULL(*btf)) 997 return IS_ERR(*btf) ? PTR_ERR(*btf) : -EINVAL; 998 999 if (ptr->type_id > 0) 1000 *btf_id = ptr->type_id; 1001 else 1002 return -EINVAL; 1003 1004 if (*btf_id > 0) 1005 t = btf_type_by_id(*btf, *btf_id); 1006 if (*btf_id <= 0 || !t) 1007 return -ENOENT; 1008 1009 return 0; 1010 } 1011 1012 BPF_CALL_5(bpf_snprintf_btf, char *, str, u32, str_size, struct btf_ptr *, ptr, 1013 u32, btf_ptr_size, u64, flags) 1014 { 1015 const struct btf *btf; 1016 s32 btf_id; 1017 int ret; 1018 1019 ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id); 1020 if (ret) 1021 return ret; 1022 1023 return btf_type_snprintf_show(btf, btf_id, ptr->ptr, str, str_size, 1024 flags); 1025 } 1026 1027 const struct bpf_func_proto bpf_snprintf_btf_proto = { 1028 .func = bpf_snprintf_btf, 1029 .gpl_only = false, 1030 .ret_type = RET_INTEGER, 1031 .arg1_type = ARG_PTR_TO_MEM, 1032 .arg2_type = ARG_CONST_SIZE, 1033 .arg3_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1034 .arg4_type = ARG_CONST_SIZE, 1035 .arg5_type = ARG_ANYTHING, 1036 }; 1037 1038 BPF_CALL_1(bpf_get_func_ip_tracing, void *, ctx) 1039 { 1040 /* This helper call is inlined by verifier. */ 1041 return ((u64 *)ctx)[-2]; 1042 } 1043 1044 static const struct bpf_func_proto bpf_get_func_ip_proto_tracing = { 1045 .func = bpf_get_func_ip_tracing, 1046 .gpl_only = true, 1047 .ret_type = RET_INTEGER, 1048 .arg1_type = ARG_PTR_TO_CTX, 1049 }; 1050 1051 #ifdef CONFIG_X86_KERNEL_IBT 1052 static unsigned long get_entry_ip(unsigned long fentry_ip) 1053 { 1054 u32 instr; 1055 1056 /* We want to be extra safe in case entry ip is on the page edge, 1057 * but otherwise we need to avoid get_kernel_nofault()'s overhead. 1058 */ 1059 if ((fentry_ip & ~PAGE_MASK) < ENDBR_INSN_SIZE) { 1060 if (get_kernel_nofault(instr, (u32 *)(fentry_ip - ENDBR_INSN_SIZE))) 1061 return fentry_ip; 1062 } else { 1063 instr = *(u32 *)(fentry_ip - ENDBR_INSN_SIZE); 1064 } 1065 if (is_endbr(instr)) 1066 fentry_ip -= ENDBR_INSN_SIZE; 1067 return fentry_ip; 1068 } 1069 #else 1070 #define get_entry_ip(fentry_ip) fentry_ip 1071 #endif 1072 1073 BPF_CALL_1(bpf_get_func_ip_kprobe, struct pt_regs *, regs) 1074 { 1075 struct bpf_trace_run_ctx *run_ctx __maybe_unused; 1076 struct kprobe *kp; 1077 1078 #ifdef CONFIG_UPROBES 1079 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); 1080 if (run_ctx->is_uprobe) 1081 return ((struct uprobe_dispatch_data *)current->utask->vaddr)->bp_addr; 1082 #endif 1083 1084 kp = kprobe_running(); 1085 1086 if (!kp || !(kp->flags & KPROBE_FLAG_ON_FUNC_ENTRY)) 1087 return 0; 1088 1089 return get_entry_ip((uintptr_t)kp->addr); 1090 } 1091 1092 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe = { 1093 .func = bpf_get_func_ip_kprobe, 1094 .gpl_only = true, 1095 .ret_type = RET_INTEGER, 1096 .arg1_type = ARG_PTR_TO_CTX, 1097 }; 1098 1099 BPF_CALL_1(bpf_get_func_ip_kprobe_multi, struct pt_regs *, regs) 1100 { 1101 return bpf_kprobe_multi_entry_ip(current->bpf_ctx); 1102 } 1103 1104 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe_multi = { 1105 .func = bpf_get_func_ip_kprobe_multi, 1106 .gpl_only = false, 1107 .ret_type = RET_INTEGER, 1108 .arg1_type = ARG_PTR_TO_CTX, 1109 }; 1110 1111 BPF_CALL_1(bpf_get_attach_cookie_kprobe_multi, struct pt_regs *, regs) 1112 { 1113 return bpf_kprobe_multi_cookie(current->bpf_ctx); 1114 } 1115 1116 static const struct bpf_func_proto bpf_get_attach_cookie_proto_kmulti = { 1117 .func = bpf_get_attach_cookie_kprobe_multi, 1118 .gpl_only = false, 1119 .ret_type = RET_INTEGER, 1120 .arg1_type = ARG_PTR_TO_CTX, 1121 }; 1122 1123 BPF_CALL_1(bpf_get_func_ip_uprobe_multi, struct pt_regs *, regs) 1124 { 1125 return bpf_uprobe_multi_entry_ip(current->bpf_ctx); 1126 } 1127 1128 static const struct bpf_func_proto bpf_get_func_ip_proto_uprobe_multi = { 1129 .func = bpf_get_func_ip_uprobe_multi, 1130 .gpl_only = false, 1131 .ret_type = RET_INTEGER, 1132 .arg1_type = ARG_PTR_TO_CTX, 1133 }; 1134 1135 BPF_CALL_1(bpf_get_attach_cookie_uprobe_multi, struct pt_regs *, regs) 1136 { 1137 return bpf_uprobe_multi_cookie(current->bpf_ctx); 1138 } 1139 1140 static const struct bpf_func_proto bpf_get_attach_cookie_proto_umulti = { 1141 .func = bpf_get_attach_cookie_uprobe_multi, 1142 .gpl_only = false, 1143 .ret_type = RET_INTEGER, 1144 .arg1_type = ARG_PTR_TO_CTX, 1145 }; 1146 1147 BPF_CALL_1(bpf_get_attach_cookie_trace, void *, ctx) 1148 { 1149 struct bpf_trace_run_ctx *run_ctx; 1150 1151 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); 1152 return run_ctx->bpf_cookie; 1153 } 1154 1155 static const struct bpf_func_proto bpf_get_attach_cookie_proto_trace = { 1156 .func = bpf_get_attach_cookie_trace, 1157 .gpl_only = false, 1158 .ret_type = RET_INTEGER, 1159 .arg1_type = ARG_PTR_TO_CTX, 1160 }; 1161 1162 BPF_CALL_1(bpf_get_attach_cookie_pe, struct bpf_perf_event_data_kern *, ctx) 1163 { 1164 return ctx->event->bpf_cookie; 1165 } 1166 1167 static const struct bpf_func_proto bpf_get_attach_cookie_proto_pe = { 1168 .func = bpf_get_attach_cookie_pe, 1169 .gpl_only = false, 1170 .ret_type = RET_INTEGER, 1171 .arg1_type = ARG_PTR_TO_CTX, 1172 }; 1173 1174 BPF_CALL_1(bpf_get_attach_cookie_tracing, void *, ctx) 1175 { 1176 struct bpf_trace_run_ctx *run_ctx; 1177 1178 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); 1179 return run_ctx->bpf_cookie; 1180 } 1181 1182 static const struct bpf_func_proto bpf_get_attach_cookie_proto_tracing = { 1183 .func = bpf_get_attach_cookie_tracing, 1184 .gpl_only = false, 1185 .ret_type = RET_INTEGER, 1186 .arg1_type = ARG_PTR_TO_CTX, 1187 }; 1188 1189 BPF_CALL_3(bpf_get_branch_snapshot, void *, buf, u32, size, u64, flags) 1190 { 1191 static const u32 br_entry_size = sizeof(struct perf_branch_entry); 1192 u32 entry_cnt = size / br_entry_size; 1193 1194 entry_cnt = static_call(perf_snapshot_branch_stack)(buf, entry_cnt); 1195 1196 if (unlikely(flags)) 1197 return -EINVAL; 1198 1199 if (!entry_cnt) 1200 return -ENOENT; 1201 1202 return entry_cnt * br_entry_size; 1203 } 1204 1205 static const struct bpf_func_proto bpf_get_branch_snapshot_proto = { 1206 .func = bpf_get_branch_snapshot, 1207 .gpl_only = true, 1208 .ret_type = RET_INTEGER, 1209 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 1210 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 1211 }; 1212 1213 BPF_CALL_3(get_func_arg, void *, ctx, u32, n, u64 *, value) 1214 { 1215 /* This helper call is inlined by verifier. */ 1216 u64 nr_args = ((u64 *)ctx)[-1]; 1217 1218 if ((u64) n >= nr_args) 1219 return -EINVAL; 1220 *value = ((u64 *)ctx)[n]; 1221 return 0; 1222 } 1223 1224 static const struct bpf_func_proto bpf_get_func_arg_proto = { 1225 .func = get_func_arg, 1226 .ret_type = RET_INTEGER, 1227 .arg1_type = ARG_PTR_TO_CTX, 1228 .arg2_type = ARG_ANYTHING, 1229 .arg3_type = ARG_PTR_TO_LONG, 1230 }; 1231 1232 BPF_CALL_2(get_func_ret, void *, ctx, u64 *, value) 1233 { 1234 /* This helper call is inlined by verifier. */ 1235 u64 nr_args = ((u64 *)ctx)[-1]; 1236 1237 *value = ((u64 *)ctx)[nr_args]; 1238 return 0; 1239 } 1240 1241 static const struct bpf_func_proto bpf_get_func_ret_proto = { 1242 .func = get_func_ret, 1243 .ret_type = RET_INTEGER, 1244 .arg1_type = ARG_PTR_TO_CTX, 1245 .arg2_type = ARG_PTR_TO_LONG, 1246 }; 1247 1248 BPF_CALL_1(get_func_arg_cnt, void *, ctx) 1249 { 1250 /* This helper call is inlined by verifier. */ 1251 return ((u64 *)ctx)[-1]; 1252 } 1253 1254 static const struct bpf_func_proto bpf_get_func_arg_cnt_proto = { 1255 .func = get_func_arg_cnt, 1256 .ret_type = RET_INTEGER, 1257 .arg1_type = ARG_PTR_TO_CTX, 1258 }; 1259 1260 #ifdef CONFIG_KEYS 1261 __bpf_kfunc_start_defs(); 1262 1263 /** 1264 * bpf_lookup_user_key - lookup a key by its serial 1265 * @serial: key handle serial number 1266 * @flags: lookup-specific flags 1267 * 1268 * Search a key with a given *serial* and the provided *flags*. 1269 * If found, increment the reference count of the key by one, and 1270 * return it in the bpf_key structure. 1271 * 1272 * The bpf_key structure must be passed to bpf_key_put() when done 1273 * with it, so that the key reference count is decremented and the 1274 * bpf_key structure is freed. 1275 * 1276 * Permission checks are deferred to the time the key is used by 1277 * one of the available key-specific kfuncs. 1278 * 1279 * Set *flags* with KEY_LOOKUP_CREATE, to attempt creating a requested 1280 * special keyring (e.g. session keyring), if it doesn't yet exist. 1281 * Set *flags* with KEY_LOOKUP_PARTIAL, to lookup a key without waiting 1282 * for the key construction, and to retrieve uninstantiated keys (keys 1283 * without data attached to them). 1284 * 1285 * Return: a bpf_key pointer with a valid key pointer if the key is found, a 1286 * NULL pointer otherwise. 1287 */ 1288 __bpf_kfunc struct bpf_key *bpf_lookup_user_key(u32 serial, u64 flags) 1289 { 1290 key_ref_t key_ref; 1291 struct bpf_key *bkey; 1292 1293 if (flags & ~KEY_LOOKUP_ALL) 1294 return NULL; 1295 1296 /* 1297 * Permission check is deferred until the key is used, as the 1298 * intent of the caller is unknown here. 1299 */ 1300 key_ref = lookup_user_key(serial, flags, KEY_DEFER_PERM_CHECK); 1301 if (IS_ERR(key_ref)) 1302 return NULL; 1303 1304 bkey = kmalloc(sizeof(*bkey), GFP_KERNEL); 1305 if (!bkey) { 1306 key_put(key_ref_to_ptr(key_ref)); 1307 return NULL; 1308 } 1309 1310 bkey->key = key_ref_to_ptr(key_ref); 1311 bkey->has_ref = true; 1312 1313 return bkey; 1314 } 1315 1316 /** 1317 * bpf_lookup_system_key - lookup a key by a system-defined ID 1318 * @id: key ID 1319 * 1320 * Obtain a bpf_key structure with a key pointer set to the passed key ID. 1321 * The key pointer is marked as invalid, to prevent bpf_key_put() from 1322 * attempting to decrement the key reference count on that pointer. The key 1323 * pointer set in such way is currently understood only by 1324 * verify_pkcs7_signature(). 1325 * 1326 * Set *id* to one of the values defined in include/linux/verification.h: 1327 * 0 for the primary keyring (immutable keyring of system keys); 1328 * VERIFY_USE_SECONDARY_KEYRING for both the primary and secondary keyring 1329 * (where keys can be added only if they are vouched for by existing keys 1330 * in those keyrings); VERIFY_USE_PLATFORM_KEYRING for the platform 1331 * keyring (primarily used by the integrity subsystem to verify a kexec'ed 1332 * kerned image and, possibly, the initramfs signature). 1333 * 1334 * Return: a bpf_key pointer with an invalid key pointer set from the 1335 * pre-determined ID on success, a NULL pointer otherwise 1336 */ 1337 __bpf_kfunc struct bpf_key *bpf_lookup_system_key(u64 id) 1338 { 1339 struct bpf_key *bkey; 1340 1341 if (system_keyring_id_check(id) < 0) 1342 return NULL; 1343 1344 bkey = kmalloc(sizeof(*bkey), GFP_ATOMIC); 1345 if (!bkey) 1346 return NULL; 1347 1348 bkey->key = (struct key *)(unsigned long)id; 1349 bkey->has_ref = false; 1350 1351 return bkey; 1352 } 1353 1354 /** 1355 * bpf_key_put - decrement key reference count if key is valid and free bpf_key 1356 * @bkey: bpf_key structure 1357 * 1358 * Decrement the reference count of the key inside *bkey*, if the pointer 1359 * is valid, and free *bkey*. 1360 */ 1361 __bpf_kfunc void bpf_key_put(struct bpf_key *bkey) 1362 { 1363 if (bkey->has_ref) 1364 key_put(bkey->key); 1365 1366 kfree(bkey); 1367 } 1368 1369 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION 1370 /** 1371 * bpf_verify_pkcs7_signature - verify a PKCS#7 signature 1372 * @data_ptr: data to verify 1373 * @sig_ptr: signature of the data 1374 * @trusted_keyring: keyring with keys trusted for signature verification 1375 * 1376 * Verify the PKCS#7 signature *sig_ptr* against the supplied *data_ptr* 1377 * with keys in a keyring referenced by *trusted_keyring*. 1378 * 1379 * Return: 0 on success, a negative value on error. 1380 */ 1381 __bpf_kfunc int bpf_verify_pkcs7_signature(struct bpf_dynptr_kern *data_ptr, 1382 struct bpf_dynptr_kern *sig_ptr, 1383 struct bpf_key *trusted_keyring) 1384 { 1385 const void *data, *sig; 1386 u32 data_len, sig_len; 1387 int ret; 1388 1389 if (trusted_keyring->has_ref) { 1390 /* 1391 * Do the permission check deferred in bpf_lookup_user_key(). 1392 * See bpf_lookup_user_key() for more details. 1393 * 1394 * A call to key_task_permission() here would be redundant, as 1395 * it is already done by keyring_search() called by 1396 * find_asymmetric_key(). 1397 */ 1398 ret = key_validate(trusted_keyring->key); 1399 if (ret < 0) 1400 return ret; 1401 } 1402 1403 data_len = __bpf_dynptr_size(data_ptr); 1404 data = __bpf_dynptr_data(data_ptr, data_len); 1405 sig_len = __bpf_dynptr_size(sig_ptr); 1406 sig = __bpf_dynptr_data(sig_ptr, sig_len); 1407 1408 return verify_pkcs7_signature(data, data_len, sig, sig_len, 1409 trusted_keyring->key, 1410 VERIFYING_UNSPECIFIED_SIGNATURE, NULL, 1411 NULL); 1412 } 1413 #endif /* CONFIG_SYSTEM_DATA_VERIFICATION */ 1414 1415 __bpf_kfunc_end_defs(); 1416 1417 BTF_KFUNCS_START(key_sig_kfunc_set) 1418 BTF_ID_FLAGS(func, bpf_lookup_user_key, KF_ACQUIRE | KF_RET_NULL | KF_SLEEPABLE) 1419 BTF_ID_FLAGS(func, bpf_lookup_system_key, KF_ACQUIRE | KF_RET_NULL) 1420 BTF_ID_FLAGS(func, bpf_key_put, KF_RELEASE) 1421 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION 1422 BTF_ID_FLAGS(func, bpf_verify_pkcs7_signature, KF_SLEEPABLE) 1423 #endif 1424 BTF_KFUNCS_END(key_sig_kfunc_set) 1425 1426 static const struct btf_kfunc_id_set bpf_key_sig_kfunc_set = { 1427 .owner = THIS_MODULE, 1428 .set = &key_sig_kfunc_set, 1429 }; 1430 1431 static int __init bpf_key_sig_kfuncs_init(void) 1432 { 1433 return register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, 1434 &bpf_key_sig_kfunc_set); 1435 } 1436 1437 late_initcall(bpf_key_sig_kfuncs_init); 1438 #endif /* CONFIG_KEYS */ 1439 1440 /* filesystem kfuncs */ 1441 __bpf_kfunc_start_defs(); 1442 1443 /** 1444 * bpf_get_file_xattr - get xattr of a file 1445 * @file: file to get xattr from 1446 * @name__str: name of the xattr 1447 * @value_ptr: output buffer of the xattr value 1448 * 1449 * Get xattr *name__str* of *file* and store the output in *value_ptr*. 1450 * 1451 * For security reasons, only *name__str* with prefix "user." is allowed. 1452 * 1453 * Return: 0 on success, a negative value on error. 1454 */ 1455 __bpf_kfunc int bpf_get_file_xattr(struct file *file, const char *name__str, 1456 struct bpf_dynptr_kern *value_ptr) 1457 { 1458 struct dentry *dentry; 1459 u32 value_len; 1460 void *value; 1461 int ret; 1462 1463 if (strncmp(name__str, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN)) 1464 return -EPERM; 1465 1466 value_len = __bpf_dynptr_size(value_ptr); 1467 value = __bpf_dynptr_data_rw(value_ptr, value_len); 1468 if (!value) 1469 return -EINVAL; 1470 1471 dentry = file_dentry(file); 1472 ret = inode_permission(&nop_mnt_idmap, dentry->d_inode, MAY_READ); 1473 if (ret) 1474 return ret; 1475 return __vfs_getxattr(dentry, dentry->d_inode, name__str, value, value_len); 1476 } 1477 1478 __bpf_kfunc_end_defs(); 1479 1480 BTF_KFUNCS_START(fs_kfunc_set_ids) 1481 BTF_ID_FLAGS(func, bpf_get_file_xattr, KF_SLEEPABLE | KF_TRUSTED_ARGS) 1482 BTF_KFUNCS_END(fs_kfunc_set_ids) 1483 1484 static int bpf_get_file_xattr_filter(const struct bpf_prog *prog, u32 kfunc_id) 1485 { 1486 if (!btf_id_set8_contains(&fs_kfunc_set_ids, kfunc_id)) 1487 return 0; 1488 1489 /* Only allow to attach from LSM hooks, to avoid recursion */ 1490 return prog->type != BPF_PROG_TYPE_LSM ? -EACCES : 0; 1491 } 1492 1493 static const struct btf_kfunc_id_set bpf_fs_kfunc_set = { 1494 .owner = THIS_MODULE, 1495 .set = &fs_kfunc_set_ids, 1496 .filter = bpf_get_file_xattr_filter, 1497 }; 1498 1499 static int __init bpf_fs_kfuncs_init(void) 1500 { 1501 return register_btf_kfunc_id_set(BPF_PROG_TYPE_LSM, &bpf_fs_kfunc_set); 1502 } 1503 1504 late_initcall(bpf_fs_kfuncs_init); 1505 1506 static const struct bpf_func_proto * 1507 bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1508 { 1509 switch (func_id) { 1510 case BPF_FUNC_map_lookup_elem: 1511 return &bpf_map_lookup_elem_proto; 1512 case BPF_FUNC_map_update_elem: 1513 return &bpf_map_update_elem_proto; 1514 case BPF_FUNC_map_delete_elem: 1515 return &bpf_map_delete_elem_proto; 1516 case BPF_FUNC_map_push_elem: 1517 return &bpf_map_push_elem_proto; 1518 case BPF_FUNC_map_pop_elem: 1519 return &bpf_map_pop_elem_proto; 1520 case BPF_FUNC_map_peek_elem: 1521 return &bpf_map_peek_elem_proto; 1522 case BPF_FUNC_map_lookup_percpu_elem: 1523 return &bpf_map_lookup_percpu_elem_proto; 1524 case BPF_FUNC_ktime_get_ns: 1525 return &bpf_ktime_get_ns_proto; 1526 case BPF_FUNC_ktime_get_boot_ns: 1527 return &bpf_ktime_get_boot_ns_proto; 1528 case BPF_FUNC_tail_call: 1529 return &bpf_tail_call_proto; 1530 case BPF_FUNC_get_current_task: 1531 return &bpf_get_current_task_proto; 1532 case BPF_FUNC_get_current_task_btf: 1533 return &bpf_get_current_task_btf_proto; 1534 case BPF_FUNC_task_pt_regs: 1535 return &bpf_task_pt_regs_proto; 1536 case BPF_FUNC_get_current_uid_gid: 1537 return &bpf_get_current_uid_gid_proto; 1538 case BPF_FUNC_get_current_comm: 1539 return &bpf_get_current_comm_proto; 1540 case BPF_FUNC_trace_printk: 1541 return bpf_get_trace_printk_proto(); 1542 case BPF_FUNC_get_smp_processor_id: 1543 return &bpf_get_smp_processor_id_proto; 1544 case BPF_FUNC_get_numa_node_id: 1545 return &bpf_get_numa_node_id_proto; 1546 case BPF_FUNC_perf_event_read: 1547 return &bpf_perf_event_read_proto; 1548 case BPF_FUNC_current_task_under_cgroup: 1549 return &bpf_current_task_under_cgroup_proto; 1550 case BPF_FUNC_get_prandom_u32: 1551 return &bpf_get_prandom_u32_proto; 1552 case BPF_FUNC_probe_write_user: 1553 return security_locked_down(LOCKDOWN_BPF_WRITE_USER) < 0 ? 1554 NULL : bpf_get_probe_write_proto(); 1555 case BPF_FUNC_probe_read_user: 1556 return &bpf_probe_read_user_proto; 1557 case BPF_FUNC_probe_read_kernel: 1558 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1559 NULL : &bpf_probe_read_kernel_proto; 1560 case BPF_FUNC_probe_read_user_str: 1561 return &bpf_probe_read_user_str_proto; 1562 case BPF_FUNC_probe_read_kernel_str: 1563 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1564 NULL : &bpf_probe_read_kernel_str_proto; 1565 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 1566 case BPF_FUNC_probe_read: 1567 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1568 NULL : &bpf_probe_read_compat_proto; 1569 case BPF_FUNC_probe_read_str: 1570 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1571 NULL : &bpf_probe_read_compat_str_proto; 1572 #endif 1573 #ifdef CONFIG_CGROUPS 1574 case BPF_FUNC_cgrp_storage_get: 1575 return &bpf_cgrp_storage_get_proto; 1576 case BPF_FUNC_cgrp_storage_delete: 1577 return &bpf_cgrp_storage_delete_proto; 1578 #endif 1579 case BPF_FUNC_send_signal: 1580 return &bpf_send_signal_proto; 1581 case BPF_FUNC_send_signal_thread: 1582 return &bpf_send_signal_thread_proto; 1583 case BPF_FUNC_perf_event_read_value: 1584 return &bpf_perf_event_read_value_proto; 1585 case BPF_FUNC_ringbuf_output: 1586 return &bpf_ringbuf_output_proto; 1587 case BPF_FUNC_ringbuf_reserve: 1588 return &bpf_ringbuf_reserve_proto; 1589 case BPF_FUNC_ringbuf_submit: 1590 return &bpf_ringbuf_submit_proto; 1591 case BPF_FUNC_ringbuf_discard: 1592 return &bpf_ringbuf_discard_proto; 1593 case BPF_FUNC_ringbuf_query: 1594 return &bpf_ringbuf_query_proto; 1595 case BPF_FUNC_jiffies64: 1596 return &bpf_jiffies64_proto; 1597 case BPF_FUNC_get_task_stack: 1598 return &bpf_get_task_stack_proto; 1599 case BPF_FUNC_copy_from_user: 1600 return &bpf_copy_from_user_proto; 1601 case BPF_FUNC_copy_from_user_task: 1602 return &bpf_copy_from_user_task_proto; 1603 case BPF_FUNC_snprintf_btf: 1604 return &bpf_snprintf_btf_proto; 1605 case BPF_FUNC_per_cpu_ptr: 1606 return &bpf_per_cpu_ptr_proto; 1607 case BPF_FUNC_this_cpu_ptr: 1608 return &bpf_this_cpu_ptr_proto; 1609 case BPF_FUNC_task_storage_get: 1610 if (bpf_prog_check_recur(prog)) 1611 return &bpf_task_storage_get_recur_proto; 1612 return &bpf_task_storage_get_proto; 1613 case BPF_FUNC_task_storage_delete: 1614 if (bpf_prog_check_recur(prog)) 1615 return &bpf_task_storage_delete_recur_proto; 1616 return &bpf_task_storage_delete_proto; 1617 case BPF_FUNC_for_each_map_elem: 1618 return &bpf_for_each_map_elem_proto; 1619 case BPF_FUNC_snprintf: 1620 return &bpf_snprintf_proto; 1621 case BPF_FUNC_get_func_ip: 1622 return &bpf_get_func_ip_proto_tracing; 1623 case BPF_FUNC_get_branch_snapshot: 1624 return &bpf_get_branch_snapshot_proto; 1625 case BPF_FUNC_find_vma: 1626 return &bpf_find_vma_proto; 1627 case BPF_FUNC_trace_vprintk: 1628 return bpf_get_trace_vprintk_proto(); 1629 default: 1630 return bpf_base_func_proto(func_id, prog); 1631 } 1632 } 1633 1634 static bool is_kprobe_multi(const struct bpf_prog *prog) 1635 { 1636 return prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI || 1637 prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION; 1638 } 1639 1640 static inline bool is_kprobe_session(const struct bpf_prog *prog) 1641 { 1642 return prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION; 1643 } 1644 1645 static const struct bpf_func_proto * 1646 kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1647 { 1648 switch (func_id) { 1649 case BPF_FUNC_perf_event_output: 1650 return &bpf_perf_event_output_proto; 1651 case BPF_FUNC_get_stackid: 1652 return &bpf_get_stackid_proto; 1653 case BPF_FUNC_get_stack: 1654 return &bpf_get_stack_proto; 1655 #ifdef CONFIG_BPF_KPROBE_OVERRIDE 1656 case BPF_FUNC_override_return: 1657 return &bpf_override_return_proto; 1658 #endif 1659 case BPF_FUNC_get_func_ip: 1660 if (is_kprobe_multi(prog)) 1661 return &bpf_get_func_ip_proto_kprobe_multi; 1662 if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI) 1663 return &bpf_get_func_ip_proto_uprobe_multi; 1664 return &bpf_get_func_ip_proto_kprobe; 1665 case BPF_FUNC_get_attach_cookie: 1666 if (is_kprobe_multi(prog)) 1667 return &bpf_get_attach_cookie_proto_kmulti; 1668 if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI) 1669 return &bpf_get_attach_cookie_proto_umulti; 1670 return &bpf_get_attach_cookie_proto_trace; 1671 default: 1672 return bpf_tracing_func_proto(func_id, prog); 1673 } 1674 } 1675 1676 /* bpf+kprobe programs can access fields of 'struct pt_regs' */ 1677 static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type, 1678 const struct bpf_prog *prog, 1679 struct bpf_insn_access_aux *info) 1680 { 1681 if (off < 0 || off >= sizeof(struct pt_regs)) 1682 return false; 1683 if (type != BPF_READ) 1684 return false; 1685 if (off % size != 0) 1686 return false; 1687 /* 1688 * Assertion for 32 bit to make sure last 8 byte access 1689 * (BPF_DW) to the last 4 byte member is disallowed. 1690 */ 1691 if (off + size > sizeof(struct pt_regs)) 1692 return false; 1693 1694 return true; 1695 } 1696 1697 const struct bpf_verifier_ops kprobe_verifier_ops = { 1698 .get_func_proto = kprobe_prog_func_proto, 1699 .is_valid_access = kprobe_prog_is_valid_access, 1700 }; 1701 1702 const struct bpf_prog_ops kprobe_prog_ops = { 1703 }; 1704 1705 BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map, 1706 u64, flags, void *, data, u64, size) 1707 { 1708 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1709 1710 /* 1711 * r1 points to perf tracepoint buffer where first 8 bytes are hidden 1712 * from bpf program and contain a pointer to 'struct pt_regs'. Fetch it 1713 * from there and call the same bpf_perf_event_output() helper inline. 1714 */ 1715 return ____bpf_perf_event_output(regs, map, flags, data, size); 1716 } 1717 1718 static const struct bpf_func_proto bpf_perf_event_output_proto_tp = { 1719 .func = bpf_perf_event_output_tp, 1720 .gpl_only = true, 1721 .ret_type = RET_INTEGER, 1722 .arg1_type = ARG_PTR_TO_CTX, 1723 .arg2_type = ARG_CONST_MAP_PTR, 1724 .arg3_type = ARG_ANYTHING, 1725 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1726 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 1727 }; 1728 1729 BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map, 1730 u64, flags) 1731 { 1732 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1733 1734 /* 1735 * Same comment as in bpf_perf_event_output_tp(), only that this time 1736 * the other helper's function body cannot be inlined due to being 1737 * external, thus we need to call raw helper function. 1738 */ 1739 return bpf_get_stackid((unsigned long) regs, (unsigned long) map, 1740 flags, 0, 0); 1741 } 1742 1743 static const struct bpf_func_proto bpf_get_stackid_proto_tp = { 1744 .func = bpf_get_stackid_tp, 1745 .gpl_only = true, 1746 .ret_type = RET_INTEGER, 1747 .arg1_type = ARG_PTR_TO_CTX, 1748 .arg2_type = ARG_CONST_MAP_PTR, 1749 .arg3_type = ARG_ANYTHING, 1750 }; 1751 1752 BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size, 1753 u64, flags) 1754 { 1755 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1756 1757 return bpf_get_stack((unsigned long) regs, (unsigned long) buf, 1758 (unsigned long) size, flags, 0); 1759 } 1760 1761 static const struct bpf_func_proto bpf_get_stack_proto_tp = { 1762 .func = bpf_get_stack_tp, 1763 .gpl_only = true, 1764 .ret_type = RET_INTEGER, 1765 .arg1_type = ARG_PTR_TO_CTX, 1766 .arg2_type = ARG_PTR_TO_UNINIT_MEM, 1767 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1768 .arg4_type = ARG_ANYTHING, 1769 }; 1770 1771 static const struct bpf_func_proto * 1772 tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1773 { 1774 switch (func_id) { 1775 case BPF_FUNC_perf_event_output: 1776 return &bpf_perf_event_output_proto_tp; 1777 case BPF_FUNC_get_stackid: 1778 return &bpf_get_stackid_proto_tp; 1779 case BPF_FUNC_get_stack: 1780 return &bpf_get_stack_proto_tp; 1781 case BPF_FUNC_get_attach_cookie: 1782 return &bpf_get_attach_cookie_proto_trace; 1783 default: 1784 return bpf_tracing_func_proto(func_id, prog); 1785 } 1786 } 1787 1788 static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type, 1789 const struct bpf_prog *prog, 1790 struct bpf_insn_access_aux *info) 1791 { 1792 if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE) 1793 return false; 1794 if (type != BPF_READ) 1795 return false; 1796 if (off % size != 0) 1797 return false; 1798 1799 BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(__u64)); 1800 return true; 1801 } 1802 1803 const struct bpf_verifier_ops tracepoint_verifier_ops = { 1804 .get_func_proto = tp_prog_func_proto, 1805 .is_valid_access = tp_prog_is_valid_access, 1806 }; 1807 1808 const struct bpf_prog_ops tracepoint_prog_ops = { 1809 }; 1810 1811 BPF_CALL_3(bpf_perf_prog_read_value, struct bpf_perf_event_data_kern *, ctx, 1812 struct bpf_perf_event_value *, buf, u32, size) 1813 { 1814 int err = -EINVAL; 1815 1816 if (unlikely(size != sizeof(struct bpf_perf_event_value))) 1817 goto clear; 1818 err = perf_event_read_local(ctx->event, &buf->counter, &buf->enabled, 1819 &buf->running); 1820 if (unlikely(err)) 1821 goto clear; 1822 return 0; 1823 clear: 1824 memset(buf, 0, size); 1825 return err; 1826 } 1827 1828 static const struct bpf_func_proto bpf_perf_prog_read_value_proto = { 1829 .func = bpf_perf_prog_read_value, 1830 .gpl_only = true, 1831 .ret_type = RET_INTEGER, 1832 .arg1_type = ARG_PTR_TO_CTX, 1833 .arg2_type = ARG_PTR_TO_UNINIT_MEM, 1834 .arg3_type = ARG_CONST_SIZE, 1835 }; 1836 1837 BPF_CALL_4(bpf_read_branch_records, struct bpf_perf_event_data_kern *, ctx, 1838 void *, buf, u32, size, u64, flags) 1839 { 1840 static const u32 br_entry_size = sizeof(struct perf_branch_entry); 1841 struct perf_branch_stack *br_stack = ctx->data->br_stack; 1842 u32 to_copy; 1843 1844 if (unlikely(flags & ~BPF_F_GET_BRANCH_RECORDS_SIZE)) 1845 return -EINVAL; 1846 1847 if (unlikely(!(ctx->data->sample_flags & PERF_SAMPLE_BRANCH_STACK))) 1848 return -ENOENT; 1849 1850 if (unlikely(!br_stack)) 1851 return -ENOENT; 1852 1853 if (flags & BPF_F_GET_BRANCH_RECORDS_SIZE) 1854 return br_stack->nr * br_entry_size; 1855 1856 if (!buf || (size % br_entry_size != 0)) 1857 return -EINVAL; 1858 1859 to_copy = min_t(u32, br_stack->nr * br_entry_size, size); 1860 memcpy(buf, br_stack->entries, to_copy); 1861 1862 return to_copy; 1863 } 1864 1865 static const struct bpf_func_proto bpf_read_branch_records_proto = { 1866 .func = bpf_read_branch_records, 1867 .gpl_only = true, 1868 .ret_type = RET_INTEGER, 1869 .arg1_type = ARG_PTR_TO_CTX, 1870 .arg2_type = ARG_PTR_TO_MEM_OR_NULL, 1871 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1872 .arg4_type = ARG_ANYTHING, 1873 }; 1874 1875 static const struct bpf_func_proto * 1876 pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1877 { 1878 switch (func_id) { 1879 case BPF_FUNC_perf_event_output: 1880 return &bpf_perf_event_output_proto_tp; 1881 case BPF_FUNC_get_stackid: 1882 return &bpf_get_stackid_proto_pe; 1883 case BPF_FUNC_get_stack: 1884 return &bpf_get_stack_proto_pe; 1885 case BPF_FUNC_perf_prog_read_value: 1886 return &bpf_perf_prog_read_value_proto; 1887 case BPF_FUNC_read_branch_records: 1888 return &bpf_read_branch_records_proto; 1889 case BPF_FUNC_get_attach_cookie: 1890 return &bpf_get_attach_cookie_proto_pe; 1891 default: 1892 return bpf_tracing_func_proto(func_id, prog); 1893 } 1894 } 1895 1896 /* 1897 * bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp 1898 * to avoid potential recursive reuse issue when/if tracepoints are added 1899 * inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack. 1900 * 1901 * Since raw tracepoints run despite bpf_prog_active, support concurrent usage 1902 * in normal, irq, and nmi context. 1903 */ 1904 struct bpf_raw_tp_regs { 1905 struct pt_regs regs[3]; 1906 }; 1907 static DEFINE_PER_CPU(struct bpf_raw_tp_regs, bpf_raw_tp_regs); 1908 static DEFINE_PER_CPU(int, bpf_raw_tp_nest_level); 1909 static struct pt_regs *get_bpf_raw_tp_regs(void) 1910 { 1911 struct bpf_raw_tp_regs *tp_regs = this_cpu_ptr(&bpf_raw_tp_regs); 1912 int nest_level = this_cpu_inc_return(bpf_raw_tp_nest_level); 1913 1914 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(tp_regs->regs))) { 1915 this_cpu_dec(bpf_raw_tp_nest_level); 1916 return ERR_PTR(-EBUSY); 1917 } 1918 1919 return &tp_regs->regs[nest_level - 1]; 1920 } 1921 1922 static void put_bpf_raw_tp_regs(void) 1923 { 1924 this_cpu_dec(bpf_raw_tp_nest_level); 1925 } 1926 1927 BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args, 1928 struct bpf_map *, map, u64, flags, void *, data, u64, size) 1929 { 1930 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1931 int ret; 1932 1933 if (IS_ERR(regs)) 1934 return PTR_ERR(regs); 1935 1936 perf_fetch_caller_regs(regs); 1937 ret = ____bpf_perf_event_output(regs, map, flags, data, size); 1938 1939 put_bpf_raw_tp_regs(); 1940 return ret; 1941 } 1942 1943 static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = { 1944 .func = bpf_perf_event_output_raw_tp, 1945 .gpl_only = true, 1946 .ret_type = RET_INTEGER, 1947 .arg1_type = ARG_PTR_TO_CTX, 1948 .arg2_type = ARG_CONST_MAP_PTR, 1949 .arg3_type = ARG_ANYTHING, 1950 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1951 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 1952 }; 1953 1954 extern const struct bpf_func_proto bpf_skb_output_proto; 1955 extern const struct bpf_func_proto bpf_xdp_output_proto; 1956 extern const struct bpf_func_proto bpf_xdp_get_buff_len_trace_proto; 1957 1958 BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args, 1959 struct bpf_map *, map, u64, flags) 1960 { 1961 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1962 int ret; 1963 1964 if (IS_ERR(regs)) 1965 return PTR_ERR(regs); 1966 1967 perf_fetch_caller_regs(regs); 1968 /* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */ 1969 ret = bpf_get_stackid((unsigned long) regs, (unsigned long) map, 1970 flags, 0, 0); 1971 put_bpf_raw_tp_regs(); 1972 return ret; 1973 } 1974 1975 static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = { 1976 .func = bpf_get_stackid_raw_tp, 1977 .gpl_only = true, 1978 .ret_type = RET_INTEGER, 1979 .arg1_type = ARG_PTR_TO_CTX, 1980 .arg2_type = ARG_CONST_MAP_PTR, 1981 .arg3_type = ARG_ANYTHING, 1982 }; 1983 1984 BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args, 1985 void *, buf, u32, size, u64, flags) 1986 { 1987 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1988 int ret; 1989 1990 if (IS_ERR(regs)) 1991 return PTR_ERR(regs); 1992 1993 perf_fetch_caller_regs(regs); 1994 ret = bpf_get_stack((unsigned long) regs, (unsigned long) buf, 1995 (unsigned long) size, flags, 0); 1996 put_bpf_raw_tp_regs(); 1997 return ret; 1998 } 1999 2000 static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = { 2001 .func = bpf_get_stack_raw_tp, 2002 .gpl_only = true, 2003 .ret_type = RET_INTEGER, 2004 .arg1_type = ARG_PTR_TO_CTX, 2005 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 2006 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 2007 .arg4_type = ARG_ANYTHING, 2008 }; 2009 2010 static const struct bpf_func_proto * 2011 raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 2012 { 2013 switch (func_id) { 2014 case BPF_FUNC_perf_event_output: 2015 return &bpf_perf_event_output_proto_raw_tp; 2016 case BPF_FUNC_get_stackid: 2017 return &bpf_get_stackid_proto_raw_tp; 2018 case BPF_FUNC_get_stack: 2019 return &bpf_get_stack_proto_raw_tp; 2020 case BPF_FUNC_get_attach_cookie: 2021 return &bpf_get_attach_cookie_proto_tracing; 2022 default: 2023 return bpf_tracing_func_proto(func_id, prog); 2024 } 2025 } 2026 2027 const struct bpf_func_proto * 2028 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 2029 { 2030 const struct bpf_func_proto *fn; 2031 2032 switch (func_id) { 2033 #ifdef CONFIG_NET 2034 case BPF_FUNC_skb_output: 2035 return &bpf_skb_output_proto; 2036 case BPF_FUNC_xdp_output: 2037 return &bpf_xdp_output_proto; 2038 case BPF_FUNC_skc_to_tcp6_sock: 2039 return &bpf_skc_to_tcp6_sock_proto; 2040 case BPF_FUNC_skc_to_tcp_sock: 2041 return &bpf_skc_to_tcp_sock_proto; 2042 case BPF_FUNC_skc_to_tcp_timewait_sock: 2043 return &bpf_skc_to_tcp_timewait_sock_proto; 2044 case BPF_FUNC_skc_to_tcp_request_sock: 2045 return &bpf_skc_to_tcp_request_sock_proto; 2046 case BPF_FUNC_skc_to_udp6_sock: 2047 return &bpf_skc_to_udp6_sock_proto; 2048 case BPF_FUNC_skc_to_unix_sock: 2049 return &bpf_skc_to_unix_sock_proto; 2050 case BPF_FUNC_skc_to_mptcp_sock: 2051 return &bpf_skc_to_mptcp_sock_proto; 2052 case BPF_FUNC_sk_storage_get: 2053 return &bpf_sk_storage_get_tracing_proto; 2054 case BPF_FUNC_sk_storage_delete: 2055 return &bpf_sk_storage_delete_tracing_proto; 2056 case BPF_FUNC_sock_from_file: 2057 return &bpf_sock_from_file_proto; 2058 case BPF_FUNC_get_socket_cookie: 2059 return &bpf_get_socket_ptr_cookie_proto; 2060 case BPF_FUNC_xdp_get_buff_len: 2061 return &bpf_xdp_get_buff_len_trace_proto; 2062 #endif 2063 case BPF_FUNC_seq_printf: 2064 return prog->expected_attach_type == BPF_TRACE_ITER ? 2065 &bpf_seq_printf_proto : 2066 NULL; 2067 case BPF_FUNC_seq_write: 2068 return prog->expected_attach_type == BPF_TRACE_ITER ? 2069 &bpf_seq_write_proto : 2070 NULL; 2071 case BPF_FUNC_seq_printf_btf: 2072 return prog->expected_attach_type == BPF_TRACE_ITER ? 2073 &bpf_seq_printf_btf_proto : 2074 NULL; 2075 case BPF_FUNC_d_path: 2076 return &bpf_d_path_proto; 2077 case BPF_FUNC_get_func_arg: 2078 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_proto : NULL; 2079 case BPF_FUNC_get_func_ret: 2080 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_ret_proto : NULL; 2081 case BPF_FUNC_get_func_arg_cnt: 2082 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_cnt_proto : NULL; 2083 case BPF_FUNC_get_attach_cookie: 2084 if (prog->type == BPF_PROG_TYPE_TRACING && 2085 prog->expected_attach_type == BPF_TRACE_RAW_TP) 2086 return &bpf_get_attach_cookie_proto_tracing; 2087 return bpf_prog_has_trampoline(prog) ? &bpf_get_attach_cookie_proto_tracing : NULL; 2088 default: 2089 fn = raw_tp_prog_func_proto(func_id, prog); 2090 if (!fn && prog->expected_attach_type == BPF_TRACE_ITER) 2091 fn = bpf_iter_get_func_proto(func_id, prog); 2092 return fn; 2093 } 2094 } 2095 2096 static bool raw_tp_prog_is_valid_access(int off, int size, 2097 enum bpf_access_type type, 2098 const struct bpf_prog *prog, 2099 struct bpf_insn_access_aux *info) 2100 { 2101 return bpf_tracing_ctx_access(off, size, type); 2102 } 2103 2104 static bool tracing_prog_is_valid_access(int off, int size, 2105 enum bpf_access_type type, 2106 const struct bpf_prog *prog, 2107 struct bpf_insn_access_aux *info) 2108 { 2109 return bpf_tracing_btf_ctx_access(off, size, type, prog, info); 2110 } 2111 2112 int __weak bpf_prog_test_run_tracing(struct bpf_prog *prog, 2113 const union bpf_attr *kattr, 2114 union bpf_attr __user *uattr) 2115 { 2116 return -ENOTSUPP; 2117 } 2118 2119 const struct bpf_verifier_ops raw_tracepoint_verifier_ops = { 2120 .get_func_proto = raw_tp_prog_func_proto, 2121 .is_valid_access = raw_tp_prog_is_valid_access, 2122 }; 2123 2124 const struct bpf_prog_ops raw_tracepoint_prog_ops = { 2125 #ifdef CONFIG_NET 2126 .test_run = bpf_prog_test_run_raw_tp, 2127 #endif 2128 }; 2129 2130 const struct bpf_verifier_ops tracing_verifier_ops = { 2131 .get_func_proto = tracing_prog_func_proto, 2132 .is_valid_access = tracing_prog_is_valid_access, 2133 }; 2134 2135 const struct bpf_prog_ops tracing_prog_ops = { 2136 .test_run = bpf_prog_test_run_tracing, 2137 }; 2138 2139 static bool raw_tp_writable_prog_is_valid_access(int off, int size, 2140 enum bpf_access_type type, 2141 const struct bpf_prog *prog, 2142 struct bpf_insn_access_aux *info) 2143 { 2144 if (off == 0) { 2145 if (size != sizeof(u64) || type != BPF_READ) 2146 return false; 2147 info->reg_type = PTR_TO_TP_BUFFER; 2148 } 2149 return raw_tp_prog_is_valid_access(off, size, type, prog, info); 2150 } 2151 2152 const struct bpf_verifier_ops raw_tracepoint_writable_verifier_ops = { 2153 .get_func_proto = raw_tp_prog_func_proto, 2154 .is_valid_access = raw_tp_writable_prog_is_valid_access, 2155 }; 2156 2157 const struct bpf_prog_ops raw_tracepoint_writable_prog_ops = { 2158 }; 2159 2160 static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type, 2161 const struct bpf_prog *prog, 2162 struct bpf_insn_access_aux *info) 2163 { 2164 const int size_u64 = sizeof(u64); 2165 2166 if (off < 0 || off >= sizeof(struct bpf_perf_event_data)) 2167 return false; 2168 if (type != BPF_READ) 2169 return false; 2170 if (off % size != 0) { 2171 if (sizeof(unsigned long) != 4) 2172 return false; 2173 if (size != 8) 2174 return false; 2175 if (off % size != 4) 2176 return false; 2177 } 2178 2179 switch (off) { 2180 case bpf_ctx_range(struct bpf_perf_event_data, sample_period): 2181 bpf_ctx_record_field_size(info, size_u64); 2182 if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) 2183 return false; 2184 break; 2185 case bpf_ctx_range(struct bpf_perf_event_data, addr): 2186 bpf_ctx_record_field_size(info, size_u64); 2187 if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) 2188 return false; 2189 break; 2190 default: 2191 if (size != sizeof(long)) 2192 return false; 2193 } 2194 2195 return true; 2196 } 2197 2198 static u32 pe_prog_convert_ctx_access(enum bpf_access_type type, 2199 const struct bpf_insn *si, 2200 struct bpf_insn *insn_buf, 2201 struct bpf_prog *prog, u32 *target_size) 2202 { 2203 struct bpf_insn *insn = insn_buf; 2204 2205 switch (si->off) { 2206 case offsetof(struct bpf_perf_event_data, sample_period): 2207 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 2208 data), si->dst_reg, si->src_reg, 2209 offsetof(struct bpf_perf_event_data_kern, data)); 2210 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, 2211 bpf_target_off(struct perf_sample_data, period, 8, 2212 target_size)); 2213 break; 2214 case offsetof(struct bpf_perf_event_data, addr): 2215 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 2216 data), si->dst_reg, si->src_reg, 2217 offsetof(struct bpf_perf_event_data_kern, data)); 2218 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, 2219 bpf_target_off(struct perf_sample_data, addr, 8, 2220 target_size)); 2221 break; 2222 default: 2223 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 2224 regs), si->dst_reg, si->src_reg, 2225 offsetof(struct bpf_perf_event_data_kern, regs)); 2226 *insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg, 2227 si->off); 2228 break; 2229 } 2230 2231 return insn - insn_buf; 2232 } 2233 2234 const struct bpf_verifier_ops perf_event_verifier_ops = { 2235 .get_func_proto = pe_prog_func_proto, 2236 .is_valid_access = pe_prog_is_valid_access, 2237 .convert_ctx_access = pe_prog_convert_ctx_access, 2238 }; 2239 2240 const struct bpf_prog_ops perf_event_prog_ops = { 2241 }; 2242 2243 static DEFINE_MUTEX(bpf_event_mutex); 2244 2245 #define BPF_TRACE_MAX_PROGS 64 2246 2247 int perf_event_attach_bpf_prog(struct perf_event *event, 2248 struct bpf_prog *prog, 2249 u64 bpf_cookie) 2250 { 2251 struct bpf_prog_array *old_array; 2252 struct bpf_prog_array *new_array; 2253 int ret = -EEXIST; 2254 2255 /* 2256 * Kprobe override only works if they are on the function entry, 2257 * and only if they are on the opt-in list. 2258 */ 2259 if (prog->kprobe_override && 2260 (!trace_kprobe_on_func_entry(event->tp_event) || 2261 !trace_kprobe_error_injectable(event->tp_event))) 2262 return -EINVAL; 2263 2264 mutex_lock(&bpf_event_mutex); 2265 2266 if (event->prog) 2267 goto unlock; 2268 2269 old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); 2270 if (old_array && 2271 bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) { 2272 ret = -E2BIG; 2273 goto unlock; 2274 } 2275 2276 ret = bpf_prog_array_copy(old_array, NULL, prog, bpf_cookie, &new_array); 2277 if (ret < 0) 2278 goto unlock; 2279 2280 /* set the new array to event->tp_event and set event->prog */ 2281 event->prog = prog; 2282 event->bpf_cookie = bpf_cookie; 2283 rcu_assign_pointer(event->tp_event->prog_array, new_array); 2284 bpf_prog_array_free_sleepable(old_array); 2285 2286 unlock: 2287 mutex_unlock(&bpf_event_mutex); 2288 return ret; 2289 } 2290 2291 void perf_event_detach_bpf_prog(struct perf_event *event) 2292 { 2293 struct bpf_prog_array *old_array; 2294 struct bpf_prog_array *new_array; 2295 int ret; 2296 2297 mutex_lock(&bpf_event_mutex); 2298 2299 if (!event->prog) 2300 goto unlock; 2301 2302 old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); 2303 ret = bpf_prog_array_copy(old_array, event->prog, NULL, 0, &new_array); 2304 if (ret == -ENOENT) 2305 goto unlock; 2306 if (ret < 0) { 2307 bpf_prog_array_delete_safe(old_array, event->prog); 2308 } else { 2309 rcu_assign_pointer(event->tp_event->prog_array, new_array); 2310 bpf_prog_array_free_sleepable(old_array); 2311 } 2312 2313 bpf_prog_put(event->prog); 2314 event->prog = NULL; 2315 2316 unlock: 2317 mutex_unlock(&bpf_event_mutex); 2318 } 2319 2320 int perf_event_query_prog_array(struct perf_event *event, void __user *info) 2321 { 2322 struct perf_event_query_bpf __user *uquery = info; 2323 struct perf_event_query_bpf query = {}; 2324 struct bpf_prog_array *progs; 2325 u32 *ids, prog_cnt, ids_len; 2326 int ret; 2327 2328 if (!perfmon_capable()) 2329 return -EPERM; 2330 if (event->attr.type != PERF_TYPE_TRACEPOINT) 2331 return -EINVAL; 2332 if (copy_from_user(&query, uquery, sizeof(query))) 2333 return -EFAULT; 2334 2335 ids_len = query.ids_len; 2336 if (ids_len > BPF_TRACE_MAX_PROGS) 2337 return -E2BIG; 2338 ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN); 2339 if (!ids) 2340 return -ENOMEM; 2341 /* 2342 * The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which 2343 * is required when user only wants to check for uquery->prog_cnt. 2344 * There is no need to check for it since the case is handled 2345 * gracefully in bpf_prog_array_copy_info. 2346 */ 2347 2348 mutex_lock(&bpf_event_mutex); 2349 progs = bpf_event_rcu_dereference(event->tp_event->prog_array); 2350 ret = bpf_prog_array_copy_info(progs, ids, ids_len, &prog_cnt); 2351 mutex_unlock(&bpf_event_mutex); 2352 2353 if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) || 2354 copy_to_user(uquery->ids, ids, ids_len * sizeof(u32))) 2355 ret = -EFAULT; 2356 2357 kfree(ids); 2358 return ret; 2359 } 2360 2361 extern struct bpf_raw_event_map __start__bpf_raw_tp[]; 2362 extern struct bpf_raw_event_map __stop__bpf_raw_tp[]; 2363 2364 struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name) 2365 { 2366 struct bpf_raw_event_map *btp = __start__bpf_raw_tp; 2367 2368 for (; btp < __stop__bpf_raw_tp; btp++) { 2369 if (!strcmp(btp->tp->name, name)) 2370 return btp; 2371 } 2372 2373 return bpf_get_raw_tracepoint_module(name); 2374 } 2375 2376 void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp) 2377 { 2378 struct module *mod; 2379 2380 preempt_disable(); 2381 mod = __module_address((unsigned long)btp); 2382 module_put(mod); 2383 preempt_enable(); 2384 } 2385 2386 static __always_inline 2387 void __bpf_trace_run(struct bpf_raw_tp_link *link, u64 *args) 2388 { 2389 struct bpf_prog *prog = link->link.prog; 2390 struct bpf_run_ctx *old_run_ctx; 2391 struct bpf_trace_run_ctx run_ctx; 2392 2393 cant_sleep(); 2394 if (unlikely(this_cpu_inc_return(*(prog->active)) != 1)) { 2395 bpf_prog_inc_misses_counter(prog); 2396 goto out; 2397 } 2398 2399 run_ctx.bpf_cookie = link->cookie; 2400 old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx); 2401 2402 rcu_read_lock(); 2403 (void) bpf_prog_run(prog, args); 2404 rcu_read_unlock(); 2405 2406 bpf_reset_run_ctx(old_run_ctx); 2407 out: 2408 this_cpu_dec(*(prog->active)); 2409 } 2410 2411 #define UNPACK(...) __VA_ARGS__ 2412 #define REPEAT_1(FN, DL, X, ...) FN(X) 2413 #define REPEAT_2(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__) 2414 #define REPEAT_3(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_2(FN, DL, __VA_ARGS__) 2415 #define REPEAT_4(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_3(FN, DL, __VA_ARGS__) 2416 #define REPEAT_5(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_4(FN, DL, __VA_ARGS__) 2417 #define REPEAT_6(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_5(FN, DL, __VA_ARGS__) 2418 #define REPEAT_7(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_6(FN, DL, __VA_ARGS__) 2419 #define REPEAT_8(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_7(FN, DL, __VA_ARGS__) 2420 #define REPEAT_9(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_8(FN, DL, __VA_ARGS__) 2421 #define REPEAT_10(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_9(FN, DL, __VA_ARGS__) 2422 #define REPEAT_11(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_10(FN, DL, __VA_ARGS__) 2423 #define REPEAT_12(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_11(FN, DL, __VA_ARGS__) 2424 #define REPEAT(X, FN, DL, ...) REPEAT_##X(FN, DL, __VA_ARGS__) 2425 2426 #define SARG(X) u64 arg##X 2427 #define COPY(X) args[X] = arg##X 2428 2429 #define __DL_COM (,) 2430 #define __DL_SEM (;) 2431 2432 #define __SEQ_0_11 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 2433 2434 #define BPF_TRACE_DEFN_x(x) \ 2435 void bpf_trace_run##x(struct bpf_raw_tp_link *link, \ 2436 REPEAT(x, SARG, __DL_COM, __SEQ_0_11)) \ 2437 { \ 2438 u64 args[x]; \ 2439 REPEAT(x, COPY, __DL_SEM, __SEQ_0_11); \ 2440 __bpf_trace_run(link, args); \ 2441 } \ 2442 EXPORT_SYMBOL_GPL(bpf_trace_run##x) 2443 BPF_TRACE_DEFN_x(1); 2444 BPF_TRACE_DEFN_x(2); 2445 BPF_TRACE_DEFN_x(3); 2446 BPF_TRACE_DEFN_x(4); 2447 BPF_TRACE_DEFN_x(5); 2448 BPF_TRACE_DEFN_x(6); 2449 BPF_TRACE_DEFN_x(7); 2450 BPF_TRACE_DEFN_x(8); 2451 BPF_TRACE_DEFN_x(9); 2452 BPF_TRACE_DEFN_x(10); 2453 BPF_TRACE_DEFN_x(11); 2454 BPF_TRACE_DEFN_x(12); 2455 2456 int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_raw_tp_link *link) 2457 { 2458 struct tracepoint *tp = btp->tp; 2459 struct bpf_prog *prog = link->link.prog; 2460 2461 /* 2462 * check that program doesn't access arguments beyond what's 2463 * available in this tracepoint 2464 */ 2465 if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64)) 2466 return -EINVAL; 2467 2468 if (prog->aux->max_tp_access > btp->writable_size) 2469 return -EINVAL; 2470 2471 return tracepoint_probe_register_may_exist(tp, (void *)btp->bpf_func, link); 2472 } 2473 2474 int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_raw_tp_link *link) 2475 { 2476 return tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, link); 2477 } 2478 2479 int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id, 2480 u32 *fd_type, const char **buf, 2481 u64 *probe_offset, u64 *probe_addr, 2482 unsigned long *missed) 2483 { 2484 bool is_tracepoint, is_syscall_tp; 2485 struct bpf_prog *prog; 2486 int flags, err = 0; 2487 2488 prog = event->prog; 2489 if (!prog) 2490 return -ENOENT; 2491 2492 /* not supporting BPF_PROG_TYPE_PERF_EVENT yet */ 2493 if (prog->type == BPF_PROG_TYPE_PERF_EVENT) 2494 return -EOPNOTSUPP; 2495 2496 *prog_id = prog->aux->id; 2497 flags = event->tp_event->flags; 2498 is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT; 2499 is_syscall_tp = is_syscall_trace_event(event->tp_event); 2500 2501 if (is_tracepoint || is_syscall_tp) { 2502 *buf = is_tracepoint ? event->tp_event->tp->name 2503 : event->tp_event->name; 2504 /* We allow NULL pointer for tracepoint */ 2505 if (fd_type) 2506 *fd_type = BPF_FD_TYPE_TRACEPOINT; 2507 if (probe_offset) 2508 *probe_offset = 0x0; 2509 if (probe_addr) 2510 *probe_addr = 0x0; 2511 } else { 2512 /* kprobe/uprobe */ 2513 err = -EOPNOTSUPP; 2514 #ifdef CONFIG_KPROBE_EVENTS 2515 if (flags & TRACE_EVENT_FL_KPROBE) 2516 err = bpf_get_kprobe_info(event, fd_type, buf, 2517 probe_offset, probe_addr, missed, 2518 event->attr.type == PERF_TYPE_TRACEPOINT); 2519 #endif 2520 #ifdef CONFIG_UPROBE_EVENTS 2521 if (flags & TRACE_EVENT_FL_UPROBE) 2522 err = bpf_get_uprobe_info(event, fd_type, buf, 2523 probe_offset, probe_addr, 2524 event->attr.type == PERF_TYPE_TRACEPOINT); 2525 #endif 2526 } 2527 2528 return err; 2529 } 2530 2531 static int __init send_signal_irq_work_init(void) 2532 { 2533 int cpu; 2534 struct send_signal_irq_work *work; 2535 2536 for_each_possible_cpu(cpu) { 2537 work = per_cpu_ptr(&send_signal_work, cpu); 2538 init_irq_work(&work->irq_work, do_bpf_send_signal); 2539 } 2540 return 0; 2541 } 2542 2543 subsys_initcall(send_signal_irq_work_init); 2544 2545 #ifdef CONFIG_MODULES 2546 static int bpf_event_notify(struct notifier_block *nb, unsigned long op, 2547 void *module) 2548 { 2549 struct bpf_trace_module *btm, *tmp; 2550 struct module *mod = module; 2551 int ret = 0; 2552 2553 if (mod->num_bpf_raw_events == 0 || 2554 (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING)) 2555 goto out; 2556 2557 mutex_lock(&bpf_module_mutex); 2558 2559 switch (op) { 2560 case MODULE_STATE_COMING: 2561 btm = kzalloc(sizeof(*btm), GFP_KERNEL); 2562 if (btm) { 2563 btm->module = module; 2564 list_add(&btm->list, &bpf_trace_modules); 2565 } else { 2566 ret = -ENOMEM; 2567 } 2568 break; 2569 case MODULE_STATE_GOING: 2570 list_for_each_entry_safe(btm, tmp, &bpf_trace_modules, list) { 2571 if (btm->module == module) { 2572 list_del(&btm->list); 2573 kfree(btm); 2574 break; 2575 } 2576 } 2577 break; 2578 } 2579 2580 mutex_unlock(&bpf_module_mutex); 2581 2582 out: 2583 return notifier_from_errno(ret); 2584 } 2585 2586 static struct notifier_block bpf_module_nb = { 2587 .notifier_call = bpf_event_notify, 2588 }; 2589 2590 static int __init bpf_event_init(void) 2591 { 2592 register_module_notifier(&bpf_module_nb); 2593 return 0; 2594 } 2595 2596 fs_initcall(bpf_event_init); 2597 #endif /* CONFIG_MODULES */ 2598 2599 struct bpf_session_run_ctx { 2600 struct bpf_run_ctx run_ctx; 2601 bool is_return; 2602 void *data; 2603 }; 2604 2605 #ifdef CONFIG_FPROBE 2606 struct bpf_kprobe_multi_link { 2607 struct bpf_link link; 2608 struct fprobe fp; 2609 unsigned long *addrs; 2610 u64 *cookies; 2611 u32 cnt; 2612 u32 mods_cnt; 2613 struct module **mods; 2614 u32 flags; 2615 }; 2616 2617 struct bpf_kprobe_multi_run_ctx { 2618 struct bpf_session_run_ctx session_ctx; 2619 struct bpf_kprobe_multi_link *link; 2620 unsigned long entry_ip; 2621 }; 2622 2623 struct user_syms { 2624 const char **syms; 2625 char *buf; 2626 }; 2627 2628 static int copy_user_syms(struct user_syms *us, unsigned long __user *usyms, u32 cnt) 2629 { 2630 unsigned long __user usymbol; 2631 const char **syms = NULL; 2632 char *buf = NULL, *p; 2633 int err = -ENOMEM; 2634 unsigned int i; 2635 2636 syms = kvmalloc_array(cnt, sizeof(*syms), GFP_KERNEL); 2637 if (!syms) 2638 goto error; 2639 2640 buf = kvmalloc_array(cnt, KSYM_NAME_LEN, GFP_KERNEL); 2641 if (!buf) 2642 goto error; 2643 2644 for (p = buf, i = 0; i < cnt; i++) { 2645 if (__get_user(usymbol, usyms + i)) { 2646 err = -EFAULT; 2647 goto error; 2648 } 2649 err = strncpy_from_user(p, (const char __user *) usymbol, KSYM_NAME_LEN); 2650 if (err == KSYM_NAME_LEN) 2651 err = -E2BIG; 2652 if (err < 0) 2653 goto error; 2654 syms[i] = p; 2655 p += err + 1; 2656 } 2657 2658 us->syms = syms; 2659 us->buf = buf; 2660 return 0; 2661 2662 error: 2663 if (err) { 2664 kvfree(syms); 2665 kvfree(buf); 2666 } 2667 return err; 2668 } 2669 2670 static void kprobe_multi_put_modules(struct module **mods, u32 cnt) 2671 { 2672 u32 i; 2673 2674 for (i = 0; i < cnt; i++) 2675 module_put(mods[i]); 2676 } 2677 2678 static void free_user_syms(struct user_syms *us) 2679 { 2680 kvfree(us->syms); 2681 kvfree(us->buf); 2682 } 2683 2684 static void bpf_kprobe_multi_link_release(struct bpf_link *link) 2685 { 2686 struct bpf_kprobe_multi_link *kmulti_link; 2687 2688 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); 2689 unregister_fprobe(&kmulti_link->fp); 2690 kprobe_multi_put_modules(kmulti_link->mods, kmulti_link->mods_cnt); 2691 } 2692 2693 static void bpf_kprobe_multi_link_dealloc(struct bpf_link *link) 2694 { 2695 struct bpf_kprobe_multi_link *kmulti_link; 2696 2697 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); 2698 kvfree(kmulti_link->addrs); 2699 kvfree(kmulti_link->cookies); 2700 kfree(kmulti_link->mods); 2701 kfree(kmulti_link); 2702 } 2703 2704 static int bpf_kprobe_multi_link_fill_link_info(const struct bpf_link *link, 2705 struct bpf_link_info *info) 2706 { 2707 u64 __user *ucookies = u64_to_user_ptr(info->kprobe_multi.cookies); 2708 u64 __user *uaddrs = u64_to_user_ptr(info->kprobe_multi.addrs); 2709 struct bpf_kprobe_multi_link *kmulti_link; 2710 u32 ucount = info->kprobe_multi.count; 2711 int err = 0, i; 2712 2713 if (!uaddrs ^ !ucount) 2714 return -EINVAL; 2715 if (ucookies && !ucount) 2716 return -EINVAL; 2717 2718 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); 2719 info->kprobe_multi.count = kmulti_link->cnt; 2720 info->kprobe_multi.flags = kmulti_link->flags; 2721 info->kprobe_multi.missed = kmulti_link->fp.nmissed; 2722 2723 if (!uaddrs) 2724 return 0; 2725 if (ucount < kmulti_link->cnt) 2726 err = -ENOSPC; 2727 else 2728 ucount = kmulti_link->cnt; 2729 2730 if (ucookies) { 2731 if (kmulti_link->cookies) { 2732 if (copy_to_user(ucookies, kmulti_link->cookies, ucount * sizeof(u64))) 2733 return -EFAULT; 2734 } else { 2735 for (i = 0; i < ucount; i++) { 2736 if (put_user(0, ucookies + i)) 2737 return -EFAULT; 2738 } 2739 } 2740 } 2741 2742 if (kallsyms_show_value(current_cred())) { 2743 if (copy_to_user(uaddrs, kmulti_link->addrs, ucount * sizeof(u64))) 2744 return -EFAULT; 2745 } else { 2746 for (i = 0; i < ucount; i++) { 2747 if (put_user(0, uaddrs + i)) 2748 return -EFAULT; 2749 } 2750 } 2751 return err; 2752 } 2753 2754 static const struct bpf_link_ops bpf_kprobe_multi_link_lops = { 2755 .release = bpf_kprobe_multi_link_release, 2756 .dealloc_deferred = bpf_kprobe_multi_link_dealloc, 2757 .fill_link_info = bpf_kprobe_multi_link_fill_link_info, 2758 }; 2759 2760 static void bpf_kprobe_multi_cookie_swap(void *a, void *b, int size, const void *priv) 2761 { 2762 const struct bpf_kprobe_multi_link *link = priv; 2763 unsigned long *addr_a = a, *addr_b = b; 2764 u64 *cookie_a, *cookie_b; 2765 2766 cookie_a = link->cookies + (addr_a - link->addrs); 2767 cookie_b = link->cookies + (addr_b - link->addrs); 2768 2769 /* swap addr_a/addr_b and cookie_a/cookie_b values */ 2770 swap(*addr_a, *addr_b); 2771 swap(*cookie_a, *cookie_b); 2772 } 2773 2774 static int bpf_kprobe_multi_addrs_cmp(const void *a, const void *b) 2775 { 2776 const unsigned long *addr_a = a, *addr_b = b; 2777 2778 if (*addr_a == *addr_b) 2779 return 0; 2780 return *addr_a < *addr_b ? -1 : 1; 2781 } 2782 2783 static int bpf_kprobe_multi_cookie_cmp(const void *a, const void *b, const void *priv) 2784 { 2785 return bpf_kprobe_multi_addrs_cmp(a, b); 2786 } 2787 2788 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx) 2789 { 2790 struct bpf_kprobe_multi_run_ctx *run_ctx; 2791 struct bpf_kprobe_multi_link *link; 2792 u64 *cookie, entry_ip; 2793 unsigned long *addr; 2794 2795 if (WARN_ON_ONCE(!ctx)) 2796 return 0; 2797 run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, 2798 session_ctx.run_ctx); 2799 link = run_ctx->link; 2800 if (!link->cookies) 2801 return 0; 2802 entry_ip = run_ctx->entry_ip; 2803 addr = bsearch(&entry_ip, link->addrs, link->cnt, sizeof(entry_ip), 2804 bpf_kprobe_multi_addrs_cmp); 2805 if (!addr) 2806 return 0; 2807 cookie = link->cookies + (addr - link->addrs); 2808 return *cookie; 2809 } 2810 2811 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 2812 { 2813 struct bpf_kprobe_multi_run_ctx *run_ctx; 2814 2815 run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, 2816 session_ctx.run_ctx); 2817 return run_ctx->entry_ip; 2818 } 2819 2820 static int 2821 kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link, 2822 unsigned long entry_ip, struct pt_regs *regs, 2823 bool is_return, void *data) 2824 { 2825 struct bpf_kprobe_multi_run_ctx run_ctx = { 2826 .session_ctx = { 2827 .is_return = is_return, 2828 .data = data, 2829 }, 2830 .link = link, 2831 .entry_ip = entry_ip, 2832 }; 2833 struct bpf_run_ctx *old_run_ctx; 2834 int err; 2835 2836 if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) { 2837 bpf_prog_inc_misses_counter(link->link.prog); 2838 err = 0; 2839 goto out; 2840 } 2841 2842 migrate_disable(); 2843 rcu_read_lock(); 2844 old_run_ctx = bpf_set_run_ctx(&run_ctx.session_ctx.run_ctx); 2845 err = bpf_prog_run(link->link.prog, regs); 2846 bpf_reset_run_ctx(old_run_ctx); 2847 rcu_read_unlock(); 2848 migrate_enable(); 2849 2850 out: 2851 __this_cpu_dec(bpf_prog_active); 2852 return err; 2853 } 2854 2855 static int 2856 kprobe_multi_link_handler(struct fprobe *fp, unsigned long fentry_ip, 2857 unsigned long ret_ip, struct pt_regs *regs, 2858 void *data) 2859 { 2860 struct bpf_kprobe_multi_link *link; 2861 int err; 2862 2863 link = container_of(fp, struct bpf_kprobe_multi_link, fp); 2864 err = kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), regs, false, data); 2865 return is_kprobe_session(link->link.prog) ? err : 0; 2866 } 2867 2868 static void 2869 kprobe_multi_link_exit_handler(struct fprobe *fp, unsigned long fentry_ip, 2870 unsigned long ret_ip, struct pt_regs *regs, 2871 void *data) 2872 { 2873 struct bpf_kprobe_multi_link *link; 2874 2875 link = container_of(fp, struct bpf_kprobe_multi_link, fp); 2876 kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), regs, true, data); 2877 } 2878 2879 static int symbols_cmp_r(const void *a, const void *b, const void *priv) 2880 { 2881 const char **str_a = (const char **) a; 2882 const char **str_b = (const char **) b; 2883 2884 return strcmp(*str_a, *str_b); 2885 } 2886 2887 struct multi_symbols_sort { 2888 const char **funcs; 2889 u64 *cookies; 2890 }; 2891 2892 static void symbols_swap_r(void *a, void *b, int size, const void *priv) 2893 { 2894 const struct multi_symbols_sort *data = priv; 2895 const char **name_a = a, **name_b = b; 2896 2897 swap(*name_a, *name_b); 2898 2899 /* If defined, swap also related cookies. */ 2900 if (data->cookies) { 2901 u64 *cookie_a, *cookie_b; 2902 2903 cookie_a = data->cookies + (name_a - data->funcs); 2904 cookie_b = data->cookies + (name_b - data->funcs); 2905 swap(*cookie_a, *cookie_b); 2906 } 2907 } 2908 2909 struct modules_array { 2910 struct module **mods; 2911 int mods_cnt; 2912 int mods_cap; 2913 }; 2914 2915 static int add_module(struct modules_array *arr, struct module *mod) 2916 { 2917 struct module **mods; 2918 2919 if (arr->mods_cnt == arr->mods_cap) { 2920 arr->mods_cap = max(16, arr->mods_cap * 3 / 2); 2921 mods = krealloc_array(arr->mods, arr->mods_cap, sizeof(*mods), GFP_KERNEL); 2922 if (!mods) 2923 return -ENOMEM; 2924 arr->mods = mods; 2925 } 2926 2927 arr->mods[arr->mods_cnt] = mod; 2928 arr->mods_cnt++; 2929 return 0; 2930 } 2931 2932 static bool has_module(struct modules_array *arr, struct module *mod) 2933 { 2934 int i; 2935 2936 for (i = arr->mods_cnt - 1; i >= 0; i--) { 2937 if (arr->mods[i] == mod) 2938 return true; 2939 } 2940 return false; 2941 } 2942 2943 static int get_modules_for_addrs(struct module ***mods, unsigned long *addrs, u32 addrs_cnt) 2944 { 2945 struct modules_array arr = {}; 2946 u32 i, err = 0; 2947 2948 for (i = 0; i < addrs_cnt; i++) { 2949 struct module *mod; 2950 2951 preempt_disable(); 2952 mod = __module_address(addrs[i]); 2953 /* Either no module or we it's already stored */ 2954 if (!mod || has_module(&arr, mod)) { 2955 preempt_enable(); 2956 continue; 2957 } 2958 if (!try_module_get(mod)) 2959 err = -EINVAL; 2960 preempt_enable(); 2961 if (err) 2962 break; 2963 err = add_module(&arr, mod); 2964 if (err) { 2965 module_put(mod); 2966 break; 2967 } 2968 } 2969 2970 /* We return either err < 0 in case of error, ... */ 2971 if (err) { 2972 kprobe_multi_put_modules(arr.mods, arr.mods_cnt); 2973 kfree(arr.mods); 2974 return err; 2975 } 2976 2977 /* or number of modules found if everything is ok. */ 2978 *mods = arr.mods; 2979 return arr.mods_cnt; 2980 } 2981 2982 static int addrs_check_error_injection_list(unsigned long *addrs, u32 cnt) 2983 { 2984 u32 i; 2985 2986 for (i = 0; i < cnt; i++) { 2987 if (!within_error_injection_list(addrs[i])) 2988 return -EINVAL; 2989 } 2990 return 0; 2991 } 2992 2993 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 2994 { 2995 struct bpf_kprobe_multi_link *link = NULL; 2996 struct bpf_link_primer link_primer; 2997 void __user *ucookies; 2998 unsigned long *addrs; 2999 u32 flags, cnt, size; 3000 void __user *uaddrs; 3001 u64 *cookies = NULL; 3002 void __user *usyms; 3003 int err; 3004 3005 /* no support for 32bit archs yet */ 3006 if (sizeof(u64) != sizeof(void *)) 3007 return -EOPNOTSUPP; 3008 3009 if (!is_kprobe_multi(prog)) 3010 return -EINVAL; 3011 3012 flags = attr->link_create.kprobe_multi.flags; 3013 if (flags & ~BPF_F_KPROBE_MULTI_RETURN) 3014 return -EINVAL; 3015 3016 uaddrs = u64_to_user_ptr(attr->link_create.kprobe_multi.addrs); 3017 usyms = u64_to_user_ptr(attr->link_create.kprobe_multi.syms); 3018 if (!!uaddrs == !!usyms) 3019 return -EINVAL; 3020 3021 cnt = attr->link_create.kprobe_multi.cnt; 3022 if (!cnt) 3023 return -EINVAL; 3024 if (cnt > MAX_KPROBE_MULTI_CNT) 3025 return -E2BIG; 3026 3027 size = cnt * sizeof(*addrs); 3028 addrs = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL); 3029 if (!addrs) 3030 return -ENOMEM; 3031 3032 ucookies = u64_to_user_ptr(attr->link_create.kprobe_multi.cookies); 3033 if (ucookies) { 3034 cookies = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL); 3035 if (!cookies) { 3036 err = -ENOMEM; 3037 goto error; 3038 } 3039 if (copy_from_user(cookies, ucookies, size)) { 3040 err = -EFAULT; 3041 goto error; 3042 } 3043 } 3044 3045 if (uaddrs) { 3046 if (copy_from_user(addrs, uaddrs, size)) { 3047 err = -EFAULT; 3048 goto error; 3049 } 3050 } else { 3051 struct multi_symbols_sort data = { 3052 .cookies = cookies, 3053 }; 3054 struct user_syms us; 3055 3056 err = copy_user_syms(&us, usyms, cnt); 3057 if (err) 3058 goto error; 3059 3060 if (cookies) 3061 data.funcs = us.syms; 3062 3063 sort_r(us.syms, cnt, sizeof(*us.syms), symbols_cmp_r, 3064 symbols_swap_r, &data); 3065 3066 err = ftrace_lookup_symbols(us.syms, cnt, addrs); 3067 free_user_syms(&us); 3068 if (err) 3069 goto error; 3070 } 3071 3072 if (prog->kprobe_override && addrs_check_error_injection_list(addrs, cnt)) { 3073 err = -EINVAL; 3074 goto error; 3075 } 3076 3077 link = kzalloc(sizeof(*link), GFP_KERNEL); 3078 if (!link) { 3079 err = -ENOMEM; 3080 goto error; 3081 } 3082 3083 bpf_link_init(&link->link, BPF_LINK_TYPE_KPROBE_MULTI, 3084 &bpf_kprobe_multi_link_lops, prog); 3085 3086 err = bpf_link_prime(&link->link, &link_primer); 3087 if (err) 3088 goto error; 3089 3090 if (!(flags & BPF_F_KPROBE_MULTI_RETURN)) 3091 link->fp.entry_handler = kprobe_multi_link_handler; 3092 if ((flags & BPF_F_KPROBE_MULTI_RETURN) || is_kprobe_session(prog)) 3093 link->fp.exit_handler = kprobe_multi_link_exit_handler; 3094 if (is_kprobe_session(prog)) 3095 link->fp.entry_data_size = sizeof(u64); 3096 3097 link->addrs = addrs; 3098 link->cookies = cookies; 3099 link->cnt = cnt; 3100 link->flags = flags; 3101 3102 if (cookies) { 3103 /* 3104 * Sorting addresses will trigger sorting cookies as well 3105 * (check bpf_kprobe_multi_cookie_swap). This way we can 3106 * find cookie based on the address in bpf_get_attach_cookie 3107 * helper. 3108 */ 3109 sort_r(addrs, cnt, sizeof(*addrs), 3110 bpf_kprobe_multi_cookie_cmp, 3111 bpf_kprobe_multi_cookie_swap, 3112 link); 3113 } 3114 3115 err = get_modules_for_addrs(&link->mods, addrs, cnt); 3116 if (err < 0) { 3117 bpf_link_cleanup(&link_primer); 3118 return err; 3119 } 3120 link->mods_cnt = err; 3121 3122 err = register_fprobe_ips(&link->fp, addrs, cnt); 3123 if (err) { 3124 kprobe_multi_put_modules(link->mods, link->mods_cnt); 3125 bpf_link_cleanup(&link_primer); 3126 return err; 3127 } 3128 3129 return bpf_link_settle(&link_primer); 3130 3131 error: 3132 kfree(link); 3133 kvfree(addrs); 3134 kvfree(cookies); 3135 return err; 3136 } 3137 #else /* !CONFIG_FPROBE */ 3138 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 3139 { 3140 return -EOPNOTSUPP; 3141 } 3142 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx) 3143 { 3144 return 0; 3145 } 3146 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 3147 { 3148 return 0; 3149 } 3150 #endif 3151 3152 #ifdef CONFIG_UPROBES 3153 struct bpf_uprobe_multi_link; 3154 3155 struct bpf_uprobe { 3156 struct bpf_uprobe_multi_link *link; 3157 loff_t offset; 3158 unsigned long ref_ctr_offset; 3159 u64 cookie; 3160 struct uprobe_consumer consumer; 3161 }; 3162 3163 struct bpf_uprobe_multi_link { 3164 struct path path; 3165 struct bpf_link link; 3166 u32 cnt; 3167 u32 flags; 3168 struct bpf_uprobe *uprobes; 3169 struct task_struct *task; 3170 }; 3171 3172 struct bpf_uprobe_multi_run_ctx { 3173 struct bpf_run_ctx run_ctx; 3174 unsigned long entry_ip; 3175 struct bpf_uprobe *uprobe; 3176 }; 3177 3178 static void bpf_uprobe_unregister(struct path *path, struct bpf_uprobe *uprobes, 3179 u32 cnt) 3180 { 3181 u32 i; 3182 3183 for (i = 0; i < cnt; i++) { 3184 uprobe_unregister(d_real_inode(path->dentry), uprobes[i].offset, 3185 &uprobes[i].consumer); 3186 } 3187 } 3188 3189 static void bpf_uprobe_multi_link_release(struct bpf_link *link) 3190 { 3191 struct bpf_uprobe_multi_link *umulti_link; 3192 3193 umulti_link = container_of(link, struct bpf_uprobe_multi_link, link); 3194 bpf_uprobe_unregister(&umulti_link->path, umulti_link->uprobes, umulti_link->cnt); 3195 if (umulti_link->task) 3196 put_task_struct(umulti_link->task); 3197 path_put(&umulti_link->path); 3198 } 3199 3200 static void bpf_uprobe_multi_link_dealloc(struct bpf_link *link) 3201 { 3202 struct bpf_uprobe_multi_link *umulti_link; 3203 3204 umulti_link = container_of(link, struct bpf_uprobe_multi_link, link); 3205 kvfree(umulti_link->uprobes); 3206 kfree(umulti_link); 3207 } 3208 3209 static int bpf_uprobe_multi_link_fill_link_info(const struct bpf_link *link, 3210 struct bpf_link_info *info) 3211 { 3212 u64 __user *uref_ctr_offsets = u64_to_user_ptr(info->uprobe_multi.ref_ctr_offsets); 3213 u64 __user *ucookies = u64_to_user_ptr(info->uprobe_multi.cookies); 3214 u64 __user *uoffsets = u64_to_user_ptr(info->uprobe_multi.offsets); 3215 u64 __user *upath = u64_to_user_ptr(info->uprobe_multi.path); 3216 u32 upath_size = info->uprobe_multi.path_size; 3217 struct bpf_uprobe_multi_link *umulti_link; 3218 u32 ucount = info->uprobe_multi.count; 3219 int err = 0, i; 3220 long left; 3221 3222 if (!upath ^ !upath_size) 3223 return -EINVAL; 3224 3225 if ((uoffsets || uref_ctr_offsets || ucookies) && !ucount) 3226 return -EINVAL; 3227 3228 umulti_link = container_of(link, struct bpf_uprobe_multi_link, link); 3229 info->uprobe_multi.count = umulti_link->cnt; 3230 info->uprobe_multi.flags = umulti_link->flags; 3231 info->uprobe_multi.pid = umulti_link->task ? 3232 task_pid_nr_ns(umulti_link->task, task_active_pid_ns(current)) : 0; 3233 3234 if (upath) { 3235 char *p, *buf; 3236 3237 upath_size = min_t(u32, upath_size, PATH_MAX); 3238 3239 buf = kmalloc(upath_size, GFP_KERNEL); 3240 if (!buf) 3241 return -ENOMEM; 3242 p = d_path(&umulti_link->path, buf, upath_size); 3243 if (IS_ERR(p)) { 3244 kfree(buf); 3245 return PTR_ERR(p); 3246 } 3247 upath_size = buf + upath_size - p; 3248 left = copy_to_user(upath, p, upath_size); 3249 kfree(buf); 3250 if (left) 3251 return -EFAULT; 3252 info->uprobe_multi.path_size = upath_size; 3253 } 3254 3255 if (!uoffsets && !ucookies && !uref_ctr_offsets) 3256 return 0; 3257 3258 if (ucount < umulti_link->cnt) 3259 err = -ENOSPC; 3260 else 3261 ucount = umulti_link->cnt; 3262 3263 for (i = 0; i < ucount; i++) { 3264 if (uoffsets && 3265 put_user(umulti_link->uprobes[i].offset, uoffsets + i)) 3266 return -EFAULT; 3267 if (uref_ctr_offsets && 3268 put_user(umulti_link->uprobes[i].ref_ctr_offset, uref_ctr_offsets + i)) 3269 return -EFAULT; 3270 if (ucookies && 3271 put_user(umulti_link->uprobes[i].cookie, ucookies + i)) 3272 return -EFAULT; 3273 } 3274 3275 return err; 3276 } 3277 3278 static const struct bpf_link_ops bpf_uprobe_multi_link_lops = { 3279 .release = bpf_uprobe_multi_link_release, 3280 .dealloc_deferred = bpf_uprobe_multi_link_dealloc, 3281 .fill_link_info = bpf_uprobe_multi_link_fill_link_info, 3282 }; 3283 3284 static int uprobe_prog_run(struct bpf_uprobe *uprobe, 3285 unsigned long entry_ip, 3286 struct pt_regs *regs) 3287 { 3288 struct bpf_uprobe_multi_link *link = uprobe->link; 3289 struct bpf_uprobe_multi_run_ctx run_ctx = { 3290 .entry_ip = entry_ip, 3291 .uprobe = uprobe, 3292 }; 3293 struct bpf_prog *prog = link->link.prog; 3294 bool sleepable = prog->sleepable; 3295 struct bpf_run_ctx *old_run_ctx; 3296 int err = 0; 3297 3298 if (link->task && current->mm != link->task->mm) 3299 return 0; 3300 3301 if (sleepable) 3302 rcu_read_lock_trace(); 3303 else 3304 rcu_read_lock(); 3305 3306 migrate_disable(); 3307 3308 old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx); 3309 err = bpf_prog_run(link->link.prog, regs); 3310 bpf_reset_run_ctx(old_run_ctx); 3311 3312 migrate_enable(); 3313 3314 if (sleepable) 3315 rcu_read_unlock_trace(); 3316 else 3317 rcu_read_unlock(); 3318 return err; 3319 } 3320 3321 static bool 3322 uprobe_multi_link_filter(struct uprobe_consumer *con, enum uprobe_filter_ctx ctx, 3323 struct mm_struct *mm) 3324 { 3325 struct bpf_uprobe *uprobe; 3326 3327 uprobe = container_of(con, struct bpf_uprobe, consumer); 3328 return uprobe->link->task->mm == mm; 3329 } 3330 3331 static int 3332 uprobe_multi_link_handler(struct uprobe_consumer *con, struct pt_regs *regs) 3333 { 3334 struct bpf_uprobe *uprobe; 3335 3336 uprobe = container_of(con, struct bpf_uprobe, consumer); 3337 return uprobe_prog_run(uprobe, instruction_pointer(regs), regs); 3338 } 3339 3340 static int 3341 uprobe_multi_link_ret_handler(struct uprobe_consumer *con, unsigned long func, struct pt_regs *regs) 3342 { 3343 struct bpf_uprobe *uprobe; 3344 3345 uprobe = container_of(con, struct bpf_uprobe, consumer); 3346 return uprobe_prog_run(uprobe, func, regs); 3347 } 3348 3349 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 3350 { 3351 struct bpf_uprobe_multi_run_ctx *run_ctx; 3352 3353 run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx, run_ctx); 3354 return run_ctx->entry_ip; 3355 } 3356 3357 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx) 3358 { 3359 struct bpf_uprobe_multi_run_ctx *run_ctx; 3360 3361 run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx, run_ctx); 3362 return run_ctx->uprobe->cookie; 3363 } 3364 3365 int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 3366 { 3367 struct bpf_uprobe_multi_link *link = NULL; 3368 unsigned long __user *uref_ctr_offsets; 3369 struct bpf_link_primer link_primer; 3370 struct bpf_uprobe *uprobes = NULL; 3371 struct task_struct *task = NULL; 3372 unsigned long __user *uoffsets; 3373 u64 __user *ucookies; 3374 void __user *upath; 3375 u32 flags, cnt, i; 3376 struct path path; 3377 char *name; 3378 pid_t pid; 3379 int err; 3380 3381 /* no support for 32bit archs yet */ 3382 if (sizeof(u64) != sizeof(void *)) 3383 return -EOPNOTSUPP; 3384 3385 if (prog->expected_attach_type != BPF_TRACE_UPROBE_MULTI) 3386 return -EINVAL; 3387 3388 flags = attr->link_create.uprobe_multi.flags; 3389 if (flags & ~BPF_F_UPROBE_MULTI_RETURN) 3390 return -EINVAL; 3391 3392 /* 3393 * path, offsets and cnt are mandatory, 3394 * ref_ctr_offsets and cookies are optional 3395 */ 3396 upath = u64_to_user_ptr(attr->link_create.uprobe_multi.path); 3397 uoffsets = u64_to_user_ptr(attr->link_create.uprobe_multi.offsets); 3398 cnt = attr->link_create.uprobe_multi.cnt; 3399 pid = attr->link_create.uprobe_multi.pid; 3400 3401 if (!upath || !uoffsets || !cnt || pid < 0) 3402 return -EINVAL; 3403 if (cnt > MAX_UPROBE_MULTI_CNT) 3404 return -E2BIG; 3405 3406 uref_ctr_offsets = u64_to_user_ptr(attr->link_create.uprobe_multi.ref_ctr_offsets); 3407 ucookies = u64_to_user_ptr(attr->link_create.uprobe_multi.cookies); 3408 3409 name = strndup_user(upath, PATH_MAX); 3410 if (IS_ERR(name)) { 3411 err = PTR_ERR(name); 3412 return err; 3413 } 3414 3415 err = kern_path(name, LOOKUP_FOLLOW, &path); 3416 kfree(name); 3417 if (err) 3418 return err; 3419 3420 if (!d_is_reg(path.dentry)) { 3421 err = -EBADF; 3422 goto error_path_put; 3423 } 3424 3425 if (pid) { 3426 task = get_pid_task(find_vpid(pid), PIDTYPE_TGID); 3427 if (!task) { 3428 err = -ESRCH; 3429 goto error_path_put; 3430 } 3431 } 3432 3433 err = -ENOMEM; 3434 3435 link = kzalloc(sizeof(*link), GFP_KERNEL); 3436 uprobes = kvcalloc(cnt, sizeof(*uprobes), GFP_KERNEL); 3437 3438 if (!uprobes || !link) 3439 goto error_free; 3440 3441 for (i = 0; i < cnt; i++) { 3442 if (__get_user(uprobes[i].offset, uoffsets + i)) { 3443 err = -EFAULT; 3444 goto error_free; 3445 } 3446 if (uprobes[i].offset < 0) { 3447 err = -EINVAL; 3448 goto error_free; 3449 } 3450 if (uref_ctr_offsets && __get_user(uprobes[i].ref_ctr_offset, uref_ctr_offsets + i)) { 3451 err = -EFAULT; 3452 goto error_free; 3453 } 3454 if (ucookies && __get_user(uprobes[i].cookie, ucookies + i)) { 3455 err = -EFAULT; 3456 goto error_free; 3457 } 3458 3459 uprobes[i].link = link; 3460 3461 if (flags & BPF_F_UPROBE_MULTI_RETURN) 3462 uprobes[i].consumer.ret_handler = uprobe_multi_link_ret_handler; 3463 else 3464 uprobes[i].consumer.handler = uprobe_multi_link_handler; 3465 3466 if (pid) 3467 uprobes[i].consumer.filter = uprobe_multi_link_filter; 3468 } 3469 3470 link->cnt = cnt; 3471 link->uprobes = uprobes; 3472 link->path = path; 3473 link->task = task; 3474 link->flags = flags; 3475 3476 bpf_link_init(&link->link, BPF_LINK_TYPE_UPROBE_MULTI, 3477 &bpf_uprobe_multi_link_lops, prog); 3478 3479 for (i = 0; i < cnt; i++) { 3480 err = uprobe_register_refctr(d_real_inode(link->path.dentry), 3481 uprobes[i].offset, 3482 uprobes[i].ref_ctr_offset, 3483 &uprobes[i].consumer); 3484 if (err) { 3485 bpf_uprobe_unregister(&path, uprobes, i); 3486 goto error_free; 3487 } 3488 } 3489 3490 err = bpf_link_prime(&link->link, &link_primer); 3491 if (err) 3492 goto error_free; 3493 3494 return bpf_link_settle(&link_primer); 3495 3496 error_free: 3497 kvfree(uprobes); 3498 kfree(link); 3499 if (task) 3500 put_task_struct(task); 3501 error_path_put: 3502 path_put(&path); 3503 return err; 3504 } 3505 #else /* !CONFIG_UPROBES */ 3506 int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 3507 { 3508 return -EOPNOTSUPP; 3509 } 3510 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx) 3511 { 3512 return 0; 3513 } 3514 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 3515 { 3516 return 0; 3517 } 3518 #endif /* CONFIG_UPROBES */ 3519 3520 __bpf_kfunc_start_defs(); 3521 3522 __bpf_kfunc bool bpf_session_is_return(void) 3523 { 3524 struct bpf_session_run_ctx *session_ctx; 3525 3526 session_ctx = container_of(current->bpf_ctx, struct bpf_session_run_ctx, run_ctx); 3527 return session_ctx->is_return; 3528 } 3529 3530 __bpf_kfunc __u64 *bpf_session_cookie(void) 3531 { 3532 struct bpf_session_run_ctx *session_ctx; 3533 3534 session_ctx = container_of(current->bpf_ctx, struct bpf_session_run_ctx, run_ctx); 3535 return session_ctx->data; 3536 } 3537 3538 __bpf_kfunc_end_defs(); 3539 3540 BTF_KFUNCS_START(kprobe_multi_kfunc_set_ids) 3541 BTF_ID_FLAGS(func, bpf_session_is_return) 3542 BTF_ID_FLAGS(func, bpf_session_cookie) 3543 BTF_KFUNCS_END(kprobe_multi_kfunc_set_ids) 3544 3545 static int bpf_kprobe_multi_filter(const struct bpf_prog *prog, u32 kfunc_id) 3546 { 3547 if (!btf_id_set8_contains(&kprobe_multi_kfunc_set_ids, kfunc_id)) 3548 return 0; 3549 3550 if (!is_kprobe_session(prog)) 3551 return -EACCES; 3552 3553 return 0; 3554 } 3555 3556 static const struct btf_kfunc_id_set bpf_kprobe_multi_kfunc_set = { 3557 .owner = THIS_MODULE, 3558 .set = &kprobe_multi_kfunc_set_ids, 3559 .filter = bpf_kprobe_multi_filter, 3560 }; 3561 3562 static int __init bpf_kprobe_multi_kfuncs_init(void) 3563 { 3564 return register_btf_kfunc_id_set(BPF_PROG_TYPE_KPROBE, &bpf_kprobe_multi_kfunc_set); 3565 } 3566 3567 late_initcall(bpf_kprobe_multi_kfuncs_init); 3568