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 /* Being extra safe in here in case entry ip is on the page-edge. */ 1057 if (get_kernel_nofault(instr, (u32 *) fentry_ip - 1)) 1058 return fentry_ip; 1059 if (is_endbr(instr)) 1060 fentry_ip -= ENDBR_INSN_SIZE; 1061 return fentry_ip; 1062 } 1063 #else 1064 #define get_entry_ip(fentry_ip) fentry_ip 1065 #endif 1066 1067 BPF_CALL_1(bpf_get_func_ip_kprobe, struct pt_regs *, regs) 1068 { 1069 struct bpf_trace_run_ctx *run_ctx __maybe_unused; 1070 struct kprobe *kp; 1071 1072 #ifdef CONFIG_UPROBES 1073 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); 1074 if (run_ctx->is_uprobe) 1075 return ((struct uprobe_dispatch_data *)current->utask->vaddr)->bp_addr; 1076 #endif 1077 1078 kp = kprobe_running(); 1079 1080 if (!kp || !(kp->flags & KPROBE_FLAG_ON_FUNC_ENTRY)) 1081 return 0; 1082 1083 return get_entry_ip((uintptr_t)kp->addr); 1084 } 1085 1086 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe = { 1087 .func = bpf_get_func_ip_kprobe, 1088 .gpl_only = true, 1089 .ret_type = RET_INTEGER, 1090 .arg1_type = ARG_PTR_TO_CTX, 1091 }; 1092 1093 BPF_CALL_1(bpf_get_func_ip_kprobe_multi, struct pt_regs *, regs) 1094 { 1095 return bpf_kprobe_multi_entry_ip(current->bpf_ctx); 1096 } 1097 1098 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe_multi = { 1099 .func = bpf_get_func_ip_kprobe_multi, 1100 .gpl_only = false, 1101 .ret_type = RET_INTEGER, 1102 .arg1_type = ARG_PTR_TO_CTX, 1103 }; 1104 1105 BPF_CALL_1(bpf_get_attach_cookie_kprobe_multi, struct pt_regs *, regs) 1106 { 1107 return bpf_kprobe_multi_cookie(current->bpf_ctx); 1108 } 1109 1110 static const struct bpf_func_proto bpf_get_attach_cookie_proto_kmulti = { 1111 .func = bpf_get_attach_cookie_kprobe_multi, 1112 .gpl_only = false, 1113 .ret_type = RET_INTEGER, 1114 .arg1_type = ARG_PTR_TO_CTX, 1115 }; 1116 1117 BPF_CALL_1(bpf_get_func_ip_uprobe_multi, struct pt_regs *, regs) 1118 { 1119 return bpf_uprobe_multi_entry_ip(current->bpf_ctx); 1120 } 1121 1122 static const struct bpf_func_proto bpf_get_func_ip_proto_uprobe_multi = { 1123 .func = bpf_get_func_ip_uprobe_multi, 1124 .gpl_only = false, 1125 .ret_type = RET_INTEGER, 1126 .arg1_type = ARG_PTR_TO_CTX, 1127 }; 1128 1129 BPF_CALL_1(bpf_get_attach_cookie_uprobe_multi, struct pt_regs *, regs) 1130 { 1131 return bpf_uprobe_multi_cookie(current->bpf_ctx); 1132 } 1133 1134 static const struct bpf_func_proto bpf_get_attach_cookie_proto_umulti = { 1135 .func = bpf_get_attach_cookie_uprobe_multi, 1136 .gpl_only = false, 1137 .ret_type = RET_INTEGER, 1138 .arg1_type = ARG_PTR_TO_CTX, 1139 }; 1140 1141 BPF_CALL_1(bpf_get_attach_cookie_trace, void *, ctx) 1142 { 1143 struct bpf_trace_run_ctx *run_ctx; 1144 1145 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); 1146 return run_ctx->bpf_cookie; 1147 } 1148 1149 static const struct bpf_func_proto bpf_get_attach_cookie_proto_trace = { 1150 .func = bpf_get_attach_cookie_trace, 1151 .gpl_only = false, 1152 .ret_type = RET_INTEGER, 1153 .arg1_type = ARG_PTR_TO_CTX, 1154 }; 1155 1156 BPF_CALL_1(bpf_get_attach_cookie_pe, struct bpf_perf_event_data_kern *, ctx) 1157 { 1158 return ctx->event->bpf_cookie; 1159 } 1160 1161 static const struct bpf_func_proto bpf_get_attach_cookie_proto_pe = { 1162 .func = bpf_get_attach_cookie_pe, 1163 .gpl_only = false, 1164 .ret_type = RET_INTEGER, 1165 .arg1_type = ARG_PTR_TO_CTX, 1166 }; 1167 1168 BPF_CALL_1(bpf_get_attach_cookie_tracing, void *, ctx) 1169 { 1170 struct bpf_trace_run_ctx *run_ctx; 1171 1172 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); 1173 return run_ctx->bpf_cookie; 1174 } 1175 1176 static const struct bpf_func_proto bpf_get_attach_cookie_proto_tracing = { 1177 .func = bpf_get_attach_cookie_tracing, 1178 .gpl_only = false, 1179 .ret_type = RET_INTEGER, 1180 .arg1_type = ARG_PTR_TO_CTX, 1181 }; 1182 1183 BPF_CALL_3(bpf_get_branch_snapshot, void *, buf, u32, size, u64, flags) 1184 { 1185 #ifndef CONFIG_X86 1186 return -ENOENT; 1187 #else 1188 static const u32 br_entry_size = sizeof(struct perf_branch_entry); 1189 u32 entry_cnt = size / br_entry_size; 1190 1191 entry_cnt = static_call(perf_snapshot_branch_stack)(buf, entry_cnt); 1192 1193 if (unlikely(flags)) 1194 return -EINVAL; 1195 1196 if (!entry_cnt) 1197 return -ENOENT; 1198 1199 return entry_cnt * br_entry_size; 1200 #endif 1201 } 1202 1203 static const struct bpf_func_proto bpf_get_branch_snapshot_proto = { 1204 .func = bpf_get_branch_snapshot, 1205 .gpl_only = true, 1206 .ret_type = RET_INTEGER, 1207 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 1208 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 1209 }; 1210 1211 BPF_CALL_3(get_func_arg, void *, ctx, u32, n, u64 *, value) 1212 { 1213 /* This helper call is inlined by verifier. */ 1214 u64 nr_args = ((u64 *)ctx)[-1]; 1215 1216 if ((u64) n >= nr_args) 1217 return -EINVAL; 1218 *value = ((u64 *)ctx)[n]; 1219 return 0; 1220 } 1221 1222 static const struct bpf_func_proto bpf_get_func_arg_proto = { 1223 .func = get_func_arg, 1224 .ret_type = RET_INTEGER, 1225 .arg1_type = ARG_PTR_TO_CTX, 1226 .arg2_type = ARG_ANYTHING, 1227 .arg3_type = ARG_PTR_TO_LONG, 1228 }; 1229 1230 BPF_CALL_2(get_func_ret, void *, ctx, u64 *, value) 1231 { 1232 /* This helper call is inlined by verifier. */ 1233 u64 nr_args = ((u64 *)ctx)[-1]; 1234 1235 *value = ((u64 *)ctx)[nr_args]; 1236 return 0; 1237 } 1238 1239 static const struct bpf_func_proto bpf_get_func_ret_proto = { 1240 .func = get_func_ret, 1241 .ret_type = RET_INTEGER, 1242 .arg1_type = ARG_PTR_TO_CTX, 1243 .arg2_type = ARG_PTR_TO_LONG, 1244 }; 1245 1246 BPF_CALL_1(get_func_arg_cnt, void *, ctx) 1247 { 1248 /* This helper call is inlined by verifier. */ 1249 return ((u64 *)ctx)[-1]; 1250 } 1251 1252 static const struct bpf_func_proto bpf_get_func_arg_cnt_proto = { 1253 .func = get_func_arg_cnt, 1254 .ret_type = RET_INTEGER, 1255 .arg1_type = ARG_PTR_TO_CTX, 1256 }; 1257 1258 #ifdef CONFIG_KEYS 1259 __bpf_kfunc_start_defs(); 1260 1261 /** 1262 * bpf_lookup_user_key - lookup a key by its serial 1263 * @serial: key handle serial number 1264 * @flags: lookup-specific flags 1265 * 1266 * Search a key with a given *serial* and the provided *flags*. 1267 * If found, increment the reference count of the key by one, and 1268 * return it in the bpf_key structure. 1269 * 1270 * The bpf_key structure must be passed to bpf_key_put() when done 1271 * with it, so that the key reference count is decremented and the 1272 * bpf_key structure is freed. 1273 * 1274 * Permission checks are deferred to the time the key is used by 1275 * one of the available key-specific kfuncs. 1276 * 1277 * Set *flags* with KEY_LOOKUP_CREATE, to attempt creating a requested 1278 * special keyring (e.g. session keyring), if it doesn't yet exist. 1279 * Set *flags* with KEY_LOOKUP_PARTIAL, to lookup a key without waiting 1280 * for the key construction, and to retrieve uninstantiated keys (keys 1281 * without data attached to them). 1282 * 1283 * Return: a bpf_key pointer with a valid key pointer if the key is found, a 1284 * NULL pointer otherwise. 1285 */ 1286 __bpf_kfunc struct bpf_key *bpf_lookup_user_key(u32 serial, u64 flags) 1287 { 1288 key_ref_t key_ref; 1289 struct bpf_key *bkey; 1290 1291 if (flags & ~KEY_LOOKUP_ALL) 1292 return NULL; 1293 1294 /* 1295 * Permission check is deferred until the key is used, as the 1296 * intent of the caller is unknown here. 1297 */ 1298 key_ref = lookup_user_key(serial, flags, KEY_DEFER_PERM_CHECK); 1299 if (IS_ERR(key_ref)) 1300 return NULL; 1301 1302 bkey = kmalloc(sizeof(*bkey), GFP_KERNEL); 1303 if (!bkey) { 1304 key_put(key_ref_to_ptr(key_ref)); 1305 return NULL; 1306 } 1307 1308 bkey->key = key_ref_to_ptr(key_ref); 1309 bkey->has_ref = true; 1310 1311 return bkey; 1312 } 1313 1314 /** 1315 * bpf_lookup_system_key - lookup a key by a system-defined ID 1316 * @id: key ID 1317 * 1318 * Obtain a bpf_key structure with a key pointer set to the passed key ID. 1319 * The key pointer is marked as invalid, to prevent bpf_key_put() from 1320 * attempting to decrement the key reference count on that pointer. The key 1321 * pointer set in such way is currently understood only by 1322 * verify_pkcs7_signature(). 1323 * 1324 * Set *id* to one of the values defined in include/linux/verification.h: 1325 * 0 for the primary keyring (immutable keyring of system keys); 1326 * VERIFY_USE_SECONDARY_KEYRING for both the primary and secondary keyring 1327 * (where keys can be added only if they are vouched for by existing keys 1328 * in those keyrings); VERIFY_USE_PLATFORM_KEYRING for the platform 1329 * keyring (primarily used by the integrity subsystem to verify a kexec'ed 1330 * kerned image and, possibly, the initramfs signature). 1331 * 1332 * Return: a bpf_key pointer with an invalid key pointer set from the 1333 * pre-determined ID on success, a NULL pointer otherwise 1334 */ 1335 __bpf_kfunc struct bpf_key *bpf_lookup_system_key(u64 id) 1336 { 1337 struct bpf_key *bkey; 1338 1339 if (system_keyring_id_check(id) < 0) 1340 return NULL; 1341 1342 bkey = kmalloc(sizeof(*bkey), GFP_ATOMIC); 1343 if (!bkey) 1344 return NULL; 1345 1346 bkey->key = (struct key *)(unsigned long)id; 1347 bkey->has_ref = false; 1348 1349 return bkey; 1350 } 1351 1352 /** 1353 * bpf_key_put - decrement key reference count if key is valid and free bpf_key 1354 * @bkey: bpf_key structure 1355 * 1356 * Decrement the reference count of the key inside *bkey*, if the pointer 1357 * is valid, and free *bkey*. 1358 */ 1359 __bpf_kfunc void bpf_key_put(struct bpf_key *bkey) 1360 { 1361 if (bkey->has_ref) 1362 key_put(bkey->key); 1363 1364 kfree(bkey); 1365 } 1366 1367 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION 1368 /** 1369 * bpf_verify_pkcs7_signature - verify a PKCS#7 signature 1370 * @data_ptr: data to verify 1371 * @sig_ptr: signature of the data 1372 * @trusted_keyring: keyring with keys trusted for signature verification 1373 * 1374 * Verify the PKCS#7 signature *sig_ptr* against the supplied *data_ptr* 1375 * with keys in a keyring referenced by *trusted_keyring*. 1376 * 1377 * Return: 0 on success, a negative value on error. 1378 */ 1379 __bpf_kfunc int bpf_verify_pkcs7_signature(struct bpf_dynptr_kern *data_ptr, 1380 struct bpf_dynptr_kern *sig_ptr, 1381 struct bpf_key *trusted_keyring) 1382 { 1383 const void *data, *sig; 1384 u32 data_len, sig_len; 1385 int ret; 1386 1387 if (trusted_keyring->has_ref) { 1388 /* 1389 * Do the permission check deferred in bpf_lookup_user_key(). 1390 * See bpf_lookup_user_key() for more details. 1391 * 1392 * A call to key_task_permission() here would be redundant, as 1393 * it is already done by keyring_search() called by 1394 * find_asymmetric_key(). 1395 */ 1396 ret = key_validate(trusted_keyring->key); 1397 if (ret < 0) 1398 return ret; 1399 } 1400 1401 data_len = __bpf_dynptr_size(data_ptr); 1402 data = __bpf_dynptr_data(data_ptr, data_len); 1403 sig_len = __bpf_dynptr_size(sig_ptr); 1404 sig = __bpf_dynptr_data(sig_ptr, sig_len); 1405 1406 return verify_pkcs7_signature(data, data_len, sig, sig_len, 1407 trusted_keyring->key, 1408 VERIFYING_UNSPECIFIED_SIGNATURE, NULL, 1409 NULL); 1410 } 1411 #endif /* CONFIG_SYSTEM_DATA_VERIFICATION */ 1412 1413 __bpf_kfunc_end_defs(); 1414 1415 BTF_SET8_START(key_sig_kfunc_set) 1416 BTF_ID_FLAGS(func, bpf_lookup_user_key, KF_ACQUIRE | KF_RET_NULL | KF_SLEEPABLE) 1417 BTF_ID_FLAGS(func, bpf_lookup_system_key, KF_ACQUIRE | KF_RET_NULL) 1418 BTF_ID_FLAGS(func, bpf_key_put, KF_RELEASE) 1419 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION 1420 BTF_ID_FLAGS(func, bpf_verify_pkcs7_signature, KF_SLEEPABLE) 1421 #endif 1422 BTF_SET8_END(key_sig_kfunc_set) 1423 1424 static const struct btf_kfunc_id_set bpf_key_sig_kfunc_set = { 1425 .owner = THIS_MODULE, 1426 .set = &key_sig_kfunc_set, 1427 }; 1428 1429 static int __init bpf_key_sig_kfuncs_init(void) 1430 { 1431 return register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, 1432 &bpf_key_sig_kfunc_set); 1433 } 1434 1435 late_initcall(bpf_key_sig_kfuncs_init); 1436 #endif /* CONFIG_KEYS */ 1437 1438 /* filesystem kfuncs */ 1439 __bpf_kfunc_start_defs(); 1440 1441 /** 1442 * bpf_get_file_xattr - get xattr of a file 1443 * @file: file to get xattr from 1444 * @name__str: name of the xattr 1445 * @value_ptr: output buffer of the xattr value 1446 * 1447 * Get xattr *name__str* of *file* and store the output in *value_ptr*. 1448 * 1449 * For security reasons, only *name__str* with prefix "user." is allowed. 1450 * 1451 * Return: 0 on success, a negative value on error. 1452 */ 1453 __bpf_kfunc int bpf_get_file_xattr(struct file *file, const char *name__str, 1454 struct bpf_dynptr_kern *value_ptr) 1455 { 1456 struct dentry *dentry; 1457 u32 value_len; 1458 void *value; 1459 int ret; 1460 1461 if (strncmp(name__str, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN)) 1462 return -EPERM; 1463 1464 value_len = __bpf_dynptr_size(value_ptr); 1465 value = __bpf_dynptr_data_rw(value_ptr, value_len); 1466 if (!value) 1467 return -EINVAL; 1468 1469 dentry = file_dentry(file); 1470 ret = inode_permission(&nop_mnt_idmap, dentry->d_inode, MAY_READ); 1471 if (ret) 1472 return ret; 1473 return __vfs_getxattr(dentry, dentry->d_inode, name__str, value, value_len); 1474 } 1475 1476 __bpf_kfunc_end_defs(); 1477 1478 BTF_SET8_START(fs_kfunc_set_ids) 1479 BTF_ID_FLAGS(func, bpf_get_file_xattr, KF_SLEEPABLE | KF_TRUSTED_ARGS) 1480 BTF_SET8_END(fs_kfunc_set_ids) 1481 1482 static int bpf_get_file_xattr_filter(const struct bpf_prog *prog, u32 kfunc_id) 1483 { 1484 if (!btf_id_set8_contains(&fs_kfunc_set_ids, kfunc_id)) 1485 return 0; 1486 1487 /* Only allow to attach from LSM hooks, to avoid recursion */ 1488 return prog->type != BPF_PROG_TYPE_LSM ? -EACCES : 0; 1489 } 1490 1491 static const struct btf_kfunc_id_set bpf_fs_kfunc_set = { 1492 .owner = THIS_MODULE, 1493 .set = &fs_kfunc_set_ids, 1494 .filter = bpf_get_file_xattr_filter, 1495 }; 1496 1497 static int __init bpf_fs_kfuncs_init(void) 1498 { 1499 return register_btf_kfunc_id_set(BPF_PROG_TYPE_LSM, &bpf_fs_kfunc_set); 1500 } 1501 1502 late_initcall(bpf_fs_kfuncs_init); 1503 1504 static const struct bpf_func_proto * 1505 bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1506 { 1507 switch (func_id) { 1508 case BPF_FUNC_map_lookup_elem: 1509 return &bpf_map_lookup_elem_proto; 1510 case BPF_FUNC_map_update_elem: 1511 return &bpf_map_update_elem_proto; 1512 case BPF_FUNC_map_delete_elem: 1513 return &bpf_map_delete_elem_proto; 1514 case BPF_FUNC_map_push_elem: 1515 return &bpf_map_push_elem_proto; 1516 case BPF_FUNC_map_pop_elem: 1517 return &bpf_map_pop_elem_proto; 1518 case BPF_FUNC_map_peek_elem: 1519 return &bpf_map_peek_elem_proto; 1520 case BPF_FUNC_map_lookup_percpu_elem: 1521 return &bpf_map_lookup_percpu_elem_proto; 1522 case BPF_FUNC_ktime_get_ns: 1523 return &bpf_ktime_get_ns_proto; 1524 case BPF_FUNC_ktime_get_boot_ns: 1525 return &bpf_ktime_get_boot_ns_proto; 1526 case BPF_FUNC_tail_call: 1527 return &bpf_tail_call_proto; 1528 case BPF_FUNC_get_current_pid_tgid: 1529 return &bpf_get_current_pid_tgid_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_get_ns_current_pid_tgid: 1586 return &bpf_get_ns_current_pid_tgid_proto; 1587 case BPF_FUNC_ringbuf_output: 1588 return &bpf_ringbuf_output_proto; 1589 case BPF_FUNC_ringbuf_reserve: 1590 return &bpf_ringbuf_reserve_proto; 1591 case BPF_FUNC_ringbuf_submit: 1592 return &bpf_ringbuf_submit_proto; 1593 case BPF_FUNC_ringbuf_discard: 1594 return &bpf_ringbuf_discard_proto; 1595 case BPF_FUNC_ringbuf_query: 1596 return &bpf_ringbuf_query_proto; 1597 case BPF_FUNC_jiffies64: 1598 return &bpf_jiffies64_proto; 1599 case BPF_FUNC_get_task_stack: 1600 return &bpf_get_task_stack_proto; 1601 case BPF_FUNC_copy_from_user: 1602 return &bpf_copy_from_user_proto; 1603 case BPF_FUNC_copy_from_user_task: 1604 return &bpf_copy_from_user_task_proto; 1605 case BPF_FUNC_snprintf_btf: 1606 return &bpf_snprintf_btf_proto; 1607 case BPF_FUNC_per_cpu_ptr: 1608 return &bpf_per_cpu_ptr_proto; 1609 case BPF_FUNC_this_cpu_ptr: 1610 return &bpf_this_cpu_ptr_proto; 1611 case BPF_FUNC_task_storage_get: 1612 if (bpf_prog_check_recur(prog)) 1613 return &bpf_task_storage_get_recur_proto; 1614 return &bpf_task_storage_get_proto; 1615 case BPF_FUNC_task_storage_delete: 1616 if (bpf_prog_check_recur(prog)) 1617 return &bpf_task_storage_delete_recur_proto; 1618 return &bpf_task_storage_delete_proto; 1619 case BPF_FUNC_for_each_map_elem: 1620 return &bpf_for_each_map_elem_proto; 1621 case BPF_FUNC_snprintf: 1622 return &bpf_snprintf_proto; 1623 case BPF_FUNC_get_func_ip: 1624 return &bpf_get_func_ip_proto_tracing; 1625 case BPF_FUNC_get_branch_snapshot: 1626 return &bpf_get_branch_snapshot_proto; 1627 case BPF_FUNC_find_vma: 1628 return &bpf_find_vma_proto; 1629 case BPF_FUNC_trace_vprintk: 1630 return bpf_get_trace_vprintk_proto(); 1631 default: 1632 return bpf_base_func_proto(func_id); 1633 } 1634 } 1635 1636 static const struct bpf_func_proto * 1637 kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1638 { 1639 switch (func_id) { 1640 case BPF_FUNC_perf_event_output: 1641 return &bpf_perf_event_output_proto; 1642 case BPF_FUNC_get_stackid: 1643 return &bpf_get_stackid_proto; 1644 case BPF_FUNC_get_stack: 1645 return &bpf_get_stack_proto; 1646 #ifdef CONFIG_BPF_KPROBE_OVERRIDE 1647 case BPF_FUNC_override_return: 1648 return &bpf_override_return_proto; 1649 #endif 1650 case BPF_FUNC_get_func_ip: 1651 if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI) 1652 return &bpf_get_func_ip_proto_kprobe_multi; 1653 if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI) 1654 return &bpf_get_func_ip_proto_uprobe_multi; 1655 return &bpf_get_func_ip_proto_kprobe; 1656 case BPF_FUNC_get_attach_cookie: 1657 if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI) 1658 return &bpf_get_attach_cookie_proto_kmulti; 1659 if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI) 1660 return &bpf_get_attach_cookie_proto_umulti; 1661 return &bpf_get_attach_cookie_proto_trace; 1662 default: 1663 return bpf_tracing_func_proto(func_id, prog); 1664 } 1665 } 1666 1667 /* bpf+kprobe programs can access fields of 'struct pt_regs' */ 1668 static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type, 1669 const struct bpf_prog *prog, 1670 struct bpf_insn_access_aux *info) 1671 { 1672 if (off < 0 || off >= sizeof(struct pt_regs)) 1673 return false; 1674 if (type != BPF_READ) 1675 return false; 1676 if (off % size != 0) 1677 return false; 1678 /* 1679 * Assertion for 32 bit to make sure last 8 byte access 1680 * (BPF_DW) to the last 4 byte member is disallowed. 1681 */ 1682 if (off + size > sizeof(struct pt_regs)) 1683 return false; 1684 1685 return true; 1686 } 1687 1688 const struct bpf_verifier_ops kprobe_verifier_ops = { 1689 .get_func_proto = kprobe_prog_func_proto, 1690 .is_valid_access = kprobe_prog_is_valid_access, 1691 }; 1692 1693 const struct bpf_prog_ops kprobe_prog_ops = { 1694 }; 1695 1696 BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map, 1697 u64, flags, void *, data, u64, size) 1698 { 1699 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1700 1701 /* 1702 * r1 points to perf tracepoint buffer where first 8 bytes are hidden 1703 * from bpf program and contain a pointer to 'struct pt_regs'. Fetch it 1704 * from there and call the same bpf_perf_event_output() helper inline. 1705 */ 1706 return ____bpf_perf_event_output(regs, map, flags, data, size); 1707 } 1708 1709 static const struct bpf_func_proto bpf_perf_event_output_proto_tp = { 1710 .func = bpf_perf_event_output_tp, 1711 .gpl_only = true, 1712 .ret_type = RET_INTEGER, 1713 .arg1_type = ARG_PTR_TO_CTX, 1714 .arg2_type = ARG_CONST_MAP_PTR, 1715 .arg3_type = ARG_ANYTHING, 1716 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1717 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 1718 }; 1719 1720 BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map, 1721 u64, flags) 1722 { 1723 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1724 1725 /* 1726 * Same comment as in bpf_perf_event_output_tp(), only that this time 1727 * the other helper's function body cannot be inlined due to being 1728 * external, thus we need to call raw helper function. 1729 */ 1730 return bpf_get_stackid((unsigned long) regs, (unsigned long) map, 1731 flags, 0, 0); 1732 } 1733 1734 static const struct bpf_func_proto bpf_get_stackid_proto_tp = { 1735 .func = bpf_get_stackid_tp, 1736 .gpl_only = true, 1737 .ret_type = RET_INTEGER, 1738 .arg1_type = ARG_PTR_TO_CTX, 1739 .arg2_type = ARG_CONST_MAP_PTR, 1740 .arg3_type = ARG_ANYTHING, 1741 }; 1742 1743 BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size, 1744 u64, flags) 1745 { 1746 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1747 1748 return bpf_get_stack((unsigned long) regs, (unsigned long) buf, 1749 (unsigned long) size, flags, 0); 1750 } 1751 1752 static const struct bpf_func_proto bpf_get_stack_proto_tp = { 1753 .func = bpf_get_stack_tp, 1754 .gpl_only = true, 1755 .ret_type = RET_INTEGER, 1756 .arg1_type = ARG_PTR_TO_CTX, 1757 .arg2_type = ARG_PTR_TO_UNINIT_MEM, 1758 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1759 .arg4_type = ARG_ANYTHING, 1760 }; 1761 1762 static const struct bpf_func_proto * 1763 tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1764 { 1765 switch (func_id) { 1766 case BPF_FUNC_perf_event_output: 1767 return &bpf_perf_event_output_proto_tp; 1768 case BPF_FUNC_get_stackid: 1769 return &bpf_get_stackid_proto_tp; 1770 case BPF_FUNC_get_stack: 1771 return &bpf_get_stack_proto_tp; 1772 case BPF_FUNC_get_attach_cookie: 1773 return &bpf_get_attach_cookie_proto_trace; 1774 default: 1775 return bpf_tracing_func_proto(func_id, prog); 1776 } 1777 } 1778 1779 static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type, 1780 const struct bpf_prog *prog, 1781 struct bpf_insn_access_aux *info) 1782 { 1783 if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE) 1784 return false; 1785 if (type != BPF_READ) 1786 return false; 1787 if (off % size != 0) 1788 return false; 1789 1790 BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(__u64)); 1791 return true; 1792 } 1793 1794 const struct bpf_verifier_ops tracepoint_verifier_ops = { 1795 .get_func_proto = tp_prog_func_proto, 1796 .is_valid_access = tp_prog_is_valid_access, 1797 }; 1798 1799 const struct bpf_prog_ops tracepoint_prog_ops = { 1800 }; 1801 1802 BPF_CALL_3(bpf_perf_prog_read_value, struct bpf_perf_event_data_kern *, ctx, 1803 struct bpf_perf_event_value *, buf, u32, size) 1804 { 1805 int err = -EINVAL; 1806 1807 if (unlikely(size != sizeof(struct bpf_perf_event_value))) 1808 goto clear; 1809 err = perf_event_read_local(ctx->event, &buf->counter, &buf->enabled, 1810 &buf->running); 1811 if (unlikely(err)) 1812 goto clear; 1813 return 0; 1814 clear: 1815 memset(buf, 0, size); 1816 return err; 1817 } 1818 1819 static const struct bpf_func_proto bpf_perf_prog_read_value_proto = { 1820 .func = bpf_perf_prog_read_value, 1821 .gpl_only = true, 1822 .ret_type = RET_INTEGER, 1823 .arg1_type = ARG_PTR_TO_CTX, 1824 .arg2_type = ARG_PTR_TO_UNINIT_MEM, 1825 .arg3_type = ARG_CONST_SIZE, 1826 }; 1827 1828 BPF_CALL_4(bpf_read_branch_records, struct bpf_perf_event_data_kern *, ctx, 1829 void *, buf, u32, size, u64, flags) 1830 { 1831 static const u32 br_entry_size = sizeof(struct perf_branch_entry); 1832 struct perf_branch_stack *br_stack = ctx->data->br_stack; 1833 u32 to_copy; 1834 1835 if (unlikely(flags & ~BPF_F_GET_BRANCH_RECORDS_SIZE)) 1836 return -EINVAL; 1837 1838 if (unlikely(!(ctx->data->sample_flags & PERF_SAMPLE_BRANCH_STACK))) 1839 return -ENOENT; 1840 1841 if (unlikely(!br_stack)) 1842 return -ENOENT; 1843 1844 if (flags & BPF_F_GET_BRANCH_RECORDS_SIZE) 1845 return br_stack->nr * br_entry_size; 1846 1847 if (!buf || (size % br_entry_size != 0)) 1848 return -EINVAL; 1849 1850 to_copy = min_t(u32, br_stack->nr * br_entry_size, size); 1851 memcpy(buf, br_stack->entries, to_copy); 1852 1853 return to_copy; 1854 } 1855 1856 static const struct bpf_func_proto bpf_read_branch_records_proto = { 1857 .func = bpf_read_branch_records, 1858 .gpl_only = true, 1859 .ret_type = RET_INTEGER, 1860 .arg1_type = ARG_PTR_TO_CTX, 1861 .arg2_type = ARG_PTR_TO_MEM_OR_NULL, 1862 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1863 .arg4_type = ARG_ANYTHING, 1864 }; 1865 1866 static const struct bpf_func_proto * 1867 pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1868 { 1869 switch (func_id) { 1870 case BPF_FUNC_perf_event_output: 1871 return &bpf_perf_event_output_proto_tp; 1872 case BPF_FUNC_get_stackid: 1873 return &bpf_get_stackid_proto_pe; 1874 case BPF_FUNC_get_stack: 1875 return &bpf_get_stack_proto_pe; 1876 case BPF_FUNC_perf_prog_read_value: 1877 return &bpf_perf_prog_read_value_proto; 1878 case BPF_FUNC_read_branch_records: 1879 return &bpf_read_branch_records_proto; 1880 case BPF_FUNC_get_attach_cookie: 1881 return &bpf_get_attach_cookie_proto_pe; 1882 default: 1883 return bpf_tracing_func_proto(func_id, prog); 1884 } 1885 } 1886 1887 /* 1888 * bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp 1889 * to avoid potential recursive reuse issue when/if tracepoints are added 1890 * inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack. 1891 * 1892 * Since raw tracepoints run despite bpf_prog_active, support concurrent usage 1893 * in normal, irq, and nmi context. 1894 */ 1895 struct bpf_raw_tp_regs { 1896 struct pt_regs regs[3]; 1897 }; 1898 static DEFINE_PER_CPU(struct bpf_raw_tp_regs, bpf_raw_tp_regs); 1899 static DEFINE_PER_CPU(int, bpf_raw_tp_nest_level); 1900 static struct pt_regs *get_bpf_raw_tp_regs(void) 1901 { 1902 struct bpf_raw_tp_regs *tp_regs = this_cpu_ptr(&bpf_raw_tp_regs); 1903 int nest_level = this_cpu_inc_return(bpf_raw_tp_nest_level); 1904 1905 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(tp_regs->regs))) { 1906 this_cpu_dec(bpf_raw_tp_nest_level); 1907 return ERR_PTR(-EBUSY); 1908 } 1909 1910 return &tp_regs->regs[nest_level - 1]; 1911 } 1912 1913 static void put_bpf_raw_tp_regs(void) 1914 { 1915 this_cpu_dec(bpf_raw_tp_nest_level); 1916 } 1917 1918 BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args, 1919 struct bpf_map *, map, u64, flags, void *, data, u64, size) 1920 { 1921 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1922 int ret; 1923 1924 if (IS_ERR(regs)) 1925 return PTR_ERR(regs); 1926 1927 perf_fetch_caller_regs(regs); 1928 ret = ____bpf_perf_event_output(regs, map, flags, data, size); 1929 1930 put_bpf_raw_tp_regs(); 1931 return ret; 1932 } 1933 1934 static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = { 1935 .func = bpf_perf_event_output_raw_tp, 1936 .gpl_only = true, 1937 .ret_type = RET_INTEGER, 1938 .arg1_type = ARG_PTR_TO_CTX, 1939 .arg2_type = ARG_CONST_MAP_PTR, 1940 .arg3_type = ARG_ANYTHING, 1941 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1942 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 1943 }; 1944 1945 extern const struct bpf_func_proto bpf_skb_output_proto; 1946 extern const struct bpf_func_proto bpf_xdp_output_proto; 1947 extern const struct bpf_func_proto bpf_xdp_get_buff_len_trace_proto; 1948 1949 BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args, 1950 struct bpf_map *, map, u64, flags) 1951 { 1952 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1953 int ret; 1954 1955 if (IS_ERR(regs)) 1956 return PTR_ERR(regs); 1957 1958 perf_fetch_caller_regs(regs); 1959 /* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */ 1960 ret = bpf_get_stackid((unsigned long) regs, (unsigned long) map, 1961 flags, 0, 0); 1962 put_bpf_raw_tp_regs(); 1963 return ret; 1964 } 1965 1966 static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = { 1967 .func = bpf_get_stackid_raw_tp, 1968 .gpl_only = true, 1969 .ret_type = RET_INTEGER, 1970 .arg1_type = ARG_PTR_TO_CTX, 1971 .arg2_type = ARG_CONST_MAP_PTR, 1972 .arg3_type = ARG_ANYTHING, 1973 }; 1974 1975 BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args, 1976 void *, buf, u32, size, u64, flags) 1977 { 1978 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1979 int ret; 1980 1981 if (IS_ERR(regs)) 1982 return PTR_ERR(regs); 1983 1984 perf_fetch_caller_regs(regs); 1985 ret = bpf_get_stack((unsigned long) regs, (unsigned long) buf, 1986 (unsigned long) size, flags, 0); 1987 put_bpf_raw_tp_regs(); 1988 return ret; 1989 } 1990 1991 static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = { 1992 .func = bpf_get_stack_raw_tp, 1993 .gpl_only = true, 1994 .ret_type = RET_INTEGER, 1995 .arg1_type = ARG_PTR_TO_CTX, 1996 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1997 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1998 .arg4_type = ARG_ANYTHING, 1999 }; 2000 2001 static const struct bpf_func_proto * 2002 raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 2003 { 2004 switch (func_id) { 2005 case BPF_FUNC_perf_event_output: 2006 return &bpf_perf_event_output_proto_raw_tp; 2007 case BPF_FUNC_get_stackid: 2008 return &bpf_get_stackid_proto_raw_tp; 2009 case BPF_FUNC_get_stack: 2010 return &bpf_get_stack_proto_raw_tp; 2011 default: 2012 return bpf_tracing_func_proto(func_id, prog); 2013 } 2014 } 2015 2016 const struct bpf_func_proto * 2017 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 2018 { 2019 const struct bpf_func_proto *fn; 2020 2021 switch (func_id) { 2022 #ifdef CONFIG_NET 2023 case BPF_FUNC_skb_output: 2024 return &bpf_skb_output_proto; 2025 case BPF_FUNC_xdp_output: 2026 return &bpf_xdp_output_proto; 2027 case BPF_FUNC_skc_to_tcp6_sock: 2028 return &bpf_skc_to_tcp6_sock_proto; 2029 case BPF_FUNC_skc_to_tcp_sock: 2030 return &bpf_skc_to_tcp_sock_proto; 2031 case BPF_FUNC_skc_to_tcp_timewait_sock: 2032 return &bpf_skc_to_tcp_timewait_sock_proto; 2033 case BPF_FUNC_skc_to_tcp_request_sock: 2034 return &bpf_skc_to_tcp_request_sock_proto; 2035 case BPF_FUNC_skc_to_udp6_sock: 2036 return &bpf_skc_to_udp6_sock_proto; 2037 case BPF_FUNC_skc_to_unix_sock: 2038 return &bpf_skc_to_unix_sock_proto; 2039 case BPF_FUNC_skc_to_mptcp_sock: 2040 return &bpf_skc_to_mptcp_sock_proto; 2041 case BPF_FUNC_sk_storage_get: 2042 return &bpf_sk_storage_get_tracing_proto; 2043 case BPF_FUNC_sk_storage_delete: 2044 return &bpf_sk_storage_delete_tracing_proto; 2045 case BPF_FUNC_sock_from_file: 2046 return &bpf_sock_from_file_proto; 2047 case BPF_FUNC_get_socket_cookie: 2048 return &bpf_get_socket_ptr_cookie_proto; 2049 case BPF_FUNC_xdp_get_buff_len: 2050 return &bpf_xdp_get_buff_len_trace_proto; 2051 #endif 2052 case BPF_FUNC_seq_printf: 2053 return prog->expected_attach_type == BPF_TRACE_ITER ? 2054 &bpf_seq_printf_proto : 2055 NULL; 2056 case BPF_FUNC_seq_write: 2057 return prog->expected_attach_type == BPF_TRACE_ITER ? 2058 &bpf_seq_write_proto : 2059 NULL; 2060 case BPF_FUNC_seq_printf_btf: 2061 return prog->expected_attach_type == BPF_TRACE_ITER ? 2062 &bpf_seq_printf_btf_proto : 2063 NULL; 2064 case BPF_FUNC_d_path: 2065 return &bpf_d_path_proto; 2066 case BPF_FUNC_get_func_arg: 2067 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_proto : NULL; 2068 case BPF_FUNC_get_func_ret: 2069 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_ret_proto : NULL; 2070 case BPF_FUNC_get_func_arg_cnt: 2071 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_cnt_proto : NULL; 2072 case BPF_FUNC_get_attach_cookie: 2073 return bpf_prog_has_trampoline(prog) ? &bpf_get_attach_cookie_proto_tracing : NULL; 2074 default: 2075 fn = raw_tp_prog_func_proto(func_id, prog); 2076 if (!fn && prog->expected_attach_type == BPF_TRACE_ITER) 2077 fn = bpf_iter_get_func_proto(func_id, prog); 2078 return fn; 2079 } 2080 } 2081 2082 static bool raw_tp_prog_is_valid_access(int off, int size, 2083 enum bpf_access_type type, 2084 const struct bpf_prog *prog, 2085 struct bpf_insn_access_aux *info) 2086 { 2087 return bpf_tracing_ctx_access(off, size, type); 2088 } 2089 2090 static bool tracing_prog_is_valid_access(int off, int size, 2091 enum bpf_access_type type, 2092 const struct bpf_prog *prog, 2093 struct bpf_insn_access_aux *info) 2094 { 2095 return bpf_tracing_btf_ctx_access(off, size, type, prog, info); 2096 } 2097 2098 int __weak bpf_prog_test_run_tracing(struct bpf_prog *prog, 2099 const union bpf_attr *kattr, 2100 union bpf_attr __user *uattr) 2101 { 2102 return -ENOTSUPP; 2103 } 2104 2105 const struct bpf_verifier_ops raw_tracepoint_verifier_ops = { 2106 .get_func_proto = raw_tp_prog_func_proto, 2107 .is_valid_access = raw_tp_prog_is_valid_access, 2108 }; 2109 2110 const struct bpf_prog_ops raw_tracepoint_prog_ops = { 2111 #ifdef CONFIG_NET 2112 .test_run = bpf_prog_test_run_raw_tp, 2113 #endif 2114 }; 2115 2116 const struct bpf_verifier_ops tracing_verifier_ops = { 2117 .get_func_proto = tracing_prog_func_proto, 2118 .is_valid_access = tracing_prog_is_valid_access, 2119 }; 2120 2121 const struct bpf_prog_ops tracing_prog_ops = { 2122 .test_run = bpf_prog_test_run_tracing, 2123 }; 2124 2125 static bool raw_tp_writable_prog_is_valid_access(int off, int size, 2126 enum bpf_access_type type, 2127 const struct bpf_prog *prog, 2128 struct bpf_insn_access_aux *info) 2129 { 2130 if (off == 0) { 2131 if (size != sizeof(u64) || type != BPF_READ) 2132 return false; 2133 info->reg_type = PTR_TO_TP_BUFFER; 2134 } 2135 return raw_tp_prog_is_valid_access(off, size, type, prog, info); 2136 } 2137 2138 const struct bpf_verifier_ops raw_tracepoint_writable_verifier_ops = { 2139 .get_func_proto = raw_tp_prog_func_proto, 2140 .is_valid_access = raw_tp_writable_prog_is_valid_access, 2141 }; 2142 2143 const struct bpf_prog_ops raw_tracepoint_writable_prog_ops = { 2144 }; 2145 2146 static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type, 2147 const struct bpf_prog *prog, 2148 struct bpf_insn_access_aux *info) 2149 { 2150 const int size_u64 = sizeof(u64); 2151 2152 if (off < 0 || off >= sizeof(struct bpf_perf_event_data)) 2153 return false; 2154 if (type != BPF_READ) 2155 return false; 2156 if (off % size != 0) { 2157 if (sizeof(unsigned long) != 4) 2158 return false; 2159 if (size != 8) 2160 return false; 2161 if (off % size != 4) 2162 return false; 2163 } 2164 2165 switch (off) { 2166 case bpf_ctx_range(struct bpf_perf_event_data, sample_period): 2167 bpf_ctx_record_field_size(info, size_u64); 2168 if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) 2169 return false; 2170 break; 2171 case bpf_ctx_range(struct bpf_perf_event_data, addr): 2172 bpf_ctx_record_field_size(info, size_u64); 2173 if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) 2174 return false; 2175 break; 2176 default: 2177 if (size != sizeof(long)) 2178 return false; 2179 } 2180 2181 return true; 2182 } 2183 2184 static u32 pe_prog_convert_ctx_access(enum bpf_access_type type, 2185 const struct bpf_insn *si, 2186 struct bpf_insn *insn_buf, 2187 struct bpf_prog *prog, u32 *target_size) 2188 { 2189 struct bpf_insn *insn = insn_buf; 2190 2191 switch (si->off) { 2192 case offsetof(struct bpf_perf_event_data, sample_period): 2193 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 2194 data), si->dst_reg, si->src_reg, 2195 offsetof(struct bpf_perf_event_data_kern, data)); 2196 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, 2197 bpf_target_off(struct perf_sample_data, period, 8, 2198 target_size)); 2199 break; 2200 case offsetof(struct bpf_perf_event_data, addr): 2201 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 2202 data), si->dst_reg, si->src_reg, 2203 offsetof(struct bpf_perf_event_data_kern, data)); 2204 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, 2205 bpf_target_off(struct perf_sample_data, addr, 8, 2206 target_size)); 2207 break; 2208 default: 2209 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 2210 regs), si->dst_reg, si->src_reg, 2211 offsetof(struct bpf_perf_event_data_kern, regs)); 2212 *insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg, 2213 si->off); 2214 break; 2215 } 2216 2217 return insn - insn_buf; 2218 } 2219 2220 const struct bpf_verifier_ops perf_event_verifier_ops = { 2221 .get_func_proto = pe_prog_func_proto, 2222 .is_valid_access = pe_prog_is_valid_access, 2223 .convert_ctx_access = pe_prog_convert_ctx_access, 2224 }; 2225 2226 const struct bpf_prog_ops perf_event_prog_ops = { 2227 }; 2228 2229 static DEFINE_MUTEX(bpf_event_mutex); 2230 2231 #define BPF_TRACE_MAX_PROGS 64 2232 2233 int perf_event_attach_bpf_prog(struct perf_event *event, 2234 struct bpf_prog *prog, 2235 u64 bpf_cookie) 2236 { 2237 struct bpf_prog_array *old_array; 2238 struct bpf_prog_array *new_array; 2239 int ret = -EEXIST; 2240 2241 /* 2242 * Kprobe override only works if they are on the function entry, 2243 * and only if they are on the opt-in list. 2244 */ 2245 if (prog->kprobe_override && 2246 (!trace_kprobe_on_func_entry(event->tp_event) || 2247 !trace_kprobe_error_injectable(event->tp_event))) 2248 return -EINVAL; 2249 2250 mutex_lock(&bpf_event_mutex); 2251 2252 if (event->prog) 2253 goto unlock; 2254 2255 old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); 2256 if (old_array && 2257 bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) { 2258 ret = -E2BIG; 2259 goto unlock; 2260 } 2261 2262 ret = bpf_prog_array_copy(old_array, NULL, prog, bpf_cookie, &new_array); 2263 if (ret < 0) 2264 goto unlock; 2265 2266 /* set the new array to event->tp_event and set event->prog */ 2267 event->prog = prog; 2268 event->bpf_cookie = bpf_cookie; 2269 rcu_assign_pointer(event->tp_event->prog_array, new_array); 2270 bpf_prog_array_free_sleepable(old_array); 2271 2272 unlock: 2273 mutex_unlock(&bpf_event_mutex); 2274 return ret; 2275 } 2276 2277 void perf_event_detach_bpf_prog(struct perf_event *event) 2278 { 2279 struct bpf_prog_array *old_array; 2280 struct bpf_prog_array *new_array; 2281 int ret; 2282 2283 mutex_lock(&bpf_event_mutex); 2284 2285 if (!event->prog) 2286 goto unlock; 2287 2288 old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); 2289 ret = bpf_prog_array_copy(old_array, event->prog, NULL, 0, &new_array); 2290 if (ret == -ENOENT) 2291 goto unlock; 2292 if (ret < 0) { 2293 bpf_prog_array_delete_safe(old_array, event->prog); 2294 } else { 2295 rcu_assign_pointer(event->tp_event->prog_array, new_array); 2296 bpf_prog_array_free_sleepable(old_array); 2297 } 2298 2299 bpf_prog_put(event->prog); 2300 event->prog = NULL; 2301 2302 unlock: 2303 mutex_unlock(&bpf_event_mutex); 2304 } 2305 2306 int perf_event_query_prog_array(struct perf_event *event, void __user *info) 2307 { 2308 struct perf_event_query_bpf __user *uquery = info; 2309 struct perf_event_query_bpf query = {}; 2310 struct bpf_prog_array *progs; 2311 u32 *ids, prog_cnt, ids_len; 2312 int ret; 2313 2314 if (!perfmon_capable()) 2315 return -EPERM; 2316 if (event->attr.type != PERF_TYPE_TRACEPOINT) 2317 return -EINVAL; 2318 if (copy_from_user(&query, uquery, sizeof(query))) 2319 return -EFAULT; 2320 2321 ids_len = query.ids_len; 2322 if (ids_len > BPF_TRACE_MAX_PROGS) 2323 return -E2BIG; 2324 ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN); 2325 if (!ids) 2326 return -ENOMEM; 2327 /* 2328 * The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which 2329 * is required when user only wants to check for uquery->prog_cnt. 2330 * There is no need to check for it since the case is handled 2331 * gracefully in bpf_prog_array_copy_info. 2332 */ 2333 2334 mutex_lock(&bpf_event_mutex); 2335 progs = bpf_event_rcu_dereference(event->tp_event->prog_array); 2336 ret = bpf_prog_array_copy_info(progs, ids, ids_len, &prog_cnt); 2337 mutex_unlock(&bpf_event_mutex); 2338 2339 if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) || 2340 copy_to_user(uquery->ids, ids, ids_len * sizeof(u32))) 2341 ret = -EFAULT; 2342 2343 kfree(ids); 2344 return ret; 2345 } 2346 2347 extern struct bpf_raw_event_map __start__bpf_raw_tp[]; 2348 extern struct bpf_raw_event_map __stop__bpf_raw_tp[]; 2349 2350 struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name) 2351 { 2352 struct bpf_raw_event_map *btp = __start__bpf_raw_tp; 2353 2354 for (; btp < __stop__bpf_raw_tp; btp++) { 2355 if (!strcmp(btp->tp->name, name)) 2356 return btp; 2357 } 2358 2359 return bpf_get_raw_tracepoint_module(name); 2360 } 2361 2362 void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp) 2363 { 2364 struct module *mod; 2365 2366 preempt_disable(); 2367 mod = __module_address((unsigned long)btp); 2368 module_put(mod); 2369 preempt_enable(); 2370 } 2371 2372 static __always_inline 2373 void __bpf_trace_run(struct bpf_prog *prog, u64 *args) 2374 { 2375 cant_sleep(); 2376 if (unlikely(this_cpu_inc_return(*(prog->active)) != 1)) { 2377 bpf_prog_inc_misses_counter(prog); 2378 goto out; 2379 } 2380 rcu_read_lock(); 2381 (void) bpf_prog_run(prog, args); 2382 rcu_read_unlock(); 2383 out: 2384 this_cpu_dec(*(prog->active)); 2385 } 2386 2387 #define UNPACK(...) __VA_ARGS__ 2388 #define REPEAT_1(FN, DL, X, ...) FN(X) 2389 #define REPEAT_2(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__) 2390 #define REPEAT_3(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_2(FN, DL, __VA_ARGS__) 2391 #define REPEAT_4(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_3(FN, DL, __VA_ARGS__) 2392 #define REPEAT_5(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_4(FN, DL, __VA_ARGS__) 2393 #define REPEAT_6(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_5(FN, DL, __VA_ARGS__) 2394 #define REPEAT_7(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_6(FN, DL, __VA_ARGS__) 2395 #define REPEAT_8(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_7(FN, DL, __VA_ARGS__) 2396 #define REPEAT_9(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_8(FN, DL, __VA_ARGS__) 2397 #define REPEAT_10(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_9(FN, DL, __VA_ARGS__) 2398 #define REPEAT_11(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_10(FN, DL, __VA_ARGS__) 2399 #define REPEAT_12(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_11(FN, DL, __VA_ARGS__) 2400 #define REPEAT(X, FN, DL, ...) REPEAT_##X(FN, DL, __VA_ARGS__) 2401 2402 #define SARG(X) u64 arg##X 2403 #define COPY(X) args[X] = arg##X 2404 2405 #define __DL_COM (,) 2406 #define __DL_SEM (;) 2407 2408 #define __SEQ_0_11 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 2409 2410 #define BPF_TRACE_DEFN_x(x) \ 2411 void bpf_trace_run##x(struct bpf_prog *prog, \ 2412 REPEAT(x, SARG, __DL_COM, __SEQ_0_11)) \ 2413 { \ 2414 u64 args[x]; \ 2415 REPEAT(x, COPY, __DL_SEM, __SEQ_0_11); \ 2416 __bpf_trace_run(prog, args); \ 2417 } \ 2418 EXPORT_SYMBOL_GPL(bpf_trace_run##x) 2419 BPF_TRACE_DEFN_x(1); 2420 BPF_TRACE_DEFN_x(2); 2421 BPF_TRACE_DEFN_x(3); 2422 BPF_TRACE_DEFN_x(4); 2423 BPF_TRACE_DEFN_x(5); 2424 BPF_TRACE_DEFN_x(6); 2425 BPF_TRACE_DEFN_x(7); 2426 BPF_TRACE_DEFN_x(8); 2427 BPF_TRACE_DEFN_x(9); 2428 BPF_TRACE_DEFN_x(10); 2429 BPF_TRACE_DEFN_x(11); 2430 BPF_TRACE_DEFN_x(12); 2431 2432 static int __bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog) 2433 { 2434 struct tracepoint *tp = btp->tp; 2435 2436 /* 2437 * check that program doesn't access arguments beyond what's 2438 * available in this tracepoint 2439 */ 2440 if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64)) 2441 return -EINVAL; 2442 2443 if (prog->aux->max_tp_access > btp->writable_size) 2444 return -EINVAL; 2445 2446 return tracepoint_probe_register_may_exist(tp, (void *)btp->bpf_func, 2447 prog); 2448 } 2449 2450 int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog) 2451 { 2452 return __bpf_probe_register(btp, prog); 2453 } 2454 2455 int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_prog *prog) 2456 { 2457 return tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, prog); 2458 } 2459 2460 int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id, 2461 u32 *fd_type, const char **buf, 2462 u64 *probe_offset, u64 *probe_addr, 2463 unsigned long *missed) 2464 { 2465 bool is_tracepoint, is_syscall_tp; 2466 struct bpf_prog *prog; 2467 int flags, err = 0; 2468 2469 prog = event->prog; 2470 if (!prog) 2471 return -ENOENT; 2472 2473 /* not supporting BPF_PROG_TYPE_PERF_EVENT yet */ 2474 if (prog->type == BPF_PROG_TYPE_PERF_EVENT) 2475 return -EOPNOTSUPP; 2476 2477 *prog_id = prog->aux->id; 2478 flags = event->tp_event->flags; 2479 is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT; 2480 is_syscall_tp = is_syscall_trace_event(event->tp_event); 2481 2482 if (is_tracepoint || is_syscall_tp) { 2483 *buf = is_tracepoint ? event->tp_event->tp->name 2484 : event->tp_event->name; 2485 /* We allow NULL pointer for tracepoint */ 2486 if (fd_type) 2487 *fd_type = BPF_FD_TYPE_TRACEPOINT; 2488 if (probe_offset) 2489 *probe_offset = 0x0; 2490 if (probe_addr) 2491 *probe_addr = 0x0; 2492 } else { 2493 /* kprobe/uprobe */ 2494 err = -EOPNOTSUPP; 2495 #ifdef CONFIG_KPROBE_EVENTS 2496 if (flags & TRACE_EVENT_FL_KPROBE) 2497 err = bpf_get_kprobe_info(event, fd_type, buf, 2498 probe_offset, probe_addr, missed, 2499 event->attr.type == PERF_TYPE_TRACEPOINT); 2500 #endif 2501 #ifdef CONFIG_UPROBE_EVENTS 2502 if (flags & TRACE_EVENT_FL_UPROBE) 2503 err = bpf_get_uprobe_info(event, fd_type, buf, 2504 probe_offset, probe_addr, 2505 event->attr.type == PERF_TYPE_TRACEPOINT); 2506 #endif 2507 } 2508 2509 return err; 2510 } 2511 2512 static int __init send_signal_irq_work_init(void) 2513 { 2514 int cpu; 2515 struct send_signal_irq_work *work; 2516 2517 for_each_possible_cpu(cpu) { 2518 work = per_cpu_ptr(&send_signal_work, cpu); 2519 init_irq_work(&work->irq_work, do_bpf_send_signal); 2520 } 2521 return 0; 2522 } 2523 2524 subsys_initcall(send_signal_irq_work_init); 2525 2526 #ifdef CONFIG_MODULES 2527 static int bpf_event_notify(struct notifier_block *nb, unsigned long op, 2528 void *module) 2529 { 2530 struct bpf_trace_module *btm, *tmp; 2531 struct module *mod = module; 2532 int ret = 0; 2533 2534 if (mod->num_bpf_raw_events == 0 || 2535 (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING)) 2536 goto out; 2537 2538 mutex_lock(&bpf_module_mutex); 2539 2540 switch (op) { 2541 case MODULE_STATE_COMING: 2542 btm = kzalloc(sizeof(*btm), GFP_KERNEL); 2543 if (btm) { 2544 btm->module = module; 2545 list_add(&btm->list, &bpf_trace_modules); 2546 } else { 2547 ret = -ENOMEM; 2548 } 2549 break; 2550 case MODULE_STATE_GOING: 2551 list_for_each_entry_safe(btm, tmp, &bpf_trace_modules, list) { 2552 if (btm->module == module) { 2553 list_del(&btm->list); 2554 kfree(btm); 2555 break; 2556 } 2557 } 2558 break; 2559 } 2560 2561 mutex_unlock(&bpf_module_mutex); 2562 2563 out: 2564 return notifier_from_errno(ret); 2565 } 2566 2567 static struct notifier_block bpf_module_nb = { 2568 .notifier_call = bpf_event_notify, 2569 }; 2570 2571 static int __init bpf_event_init(void) 2572 { 2573 register_module_notifier(&bpf_module_nb); 2574 return 0; 2575 } 2576 2577 fs_initcall(bpf_event_init); 2578 #endif /* CONFIG_MODULES */ 2579 2580 #ifdef CONFIG_FPROBE 2581 struct bpf_kprobe_multi_link { 2582 struct bpf_link link; 2583 struct fprobe fp; 2584 unsigned long *addrs; 2585 u64 *cookies; 2586 u32 cnt; 2587 u32 mods_cnt; 2588 struct module **mods; 2589 u32 flags; 2590 }; 2591 2592 struct bpf_kprobe_multi_run_ctx { 2593 struct bpf_run_ctx run_ctx; 2594 struct bpf_kprobe_multi_link *link; 2595 unsigned long entry_ip; 2596 }; 2597 2598 struct user_syms { 2599 const char **syms; 2600 char *buf; 2601 }; 2602 2603 static int copy_user_syms(struct user_syms *us, unsigned long __user *usyms, u32 cnt) 2604 { 2605 unsigned long __user usymbol; 2606 const char **syms = NULL; 2607 char *buf = NULL, *p; 2608 int err = -ENOMEM; 2609 unsigned int i; 2610 2611 syms = kvmalloc_array(cnt, sizeof(*syms), GFP_KERNEL); 2612 if (!syms) 2613 goto error; 2614 2615 buf = kvmalloc_array(cnt, KSYM_NAME_LEN, GFP_KERNEL); 2616 if (!buf) 2617 goto error; 2618 2619 for (p = buf, i = 0; i < cnt; i++) { 2620 if (__get_user(usymbol, usyms + i)) { 2621 err = -EFAULT; 2622 goto error; 2623 } 2624 err = strncpy_from_user(p, (const char __user *) usymbol, KSYM_NAME_LEN); 2625 if (err == KSYM_NAME_LEN) 2626 err = -E2BIG; 2627 if (err < 0) 2628 goto error; 2629 syms[i] = p; 2630 p += err + 1; 2631 } 2632 2633 us->syms = syms; 2634 us->buf = buf; 2635 return 0; 2636 2637 error: 2638 if (err) { 2639 kvfree(syms); 2640 kvfree(buf); 2641 } 2642 return err; 2643 } 2644 2645 static void kprobe_multi_put_modules(struct module **mods, u32 cnt) 2646 { 2647 u32 i; 2648 2649 for (i = 0; i < cnt; i++) 2650 module_put(mods[i]); 2651 } 2652 2653 static void free_user_syms(struct user_syms *us) 2654 { 2655 kvfree(us->syms); 2656 kvfree(us->buf); 2657 } 2658 2659 static void bpf_kprobe_multi_link_release(struct bpf_link *link) 2660 { 2661 struct bpf_kprobe_multi_link *kmulti_link; 2662 2663 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); 2664 unregister_fprobe(&kmulti_link->fp); 2665 kprobe_multi_put_modules(kmulti_link->mods, kmulti_link->mods_cnt); 2666 } 2667 2668 static void bpf_kprobe_multi_link_dealloc(struct bpf_link *link) 2669 { 2670 struct bpf_kprobe_multi_link *kmulti_link; 2671 2672 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); 2673 kvfree(kmulti_link->addrs); 2674 kvfree(kmulti_link->cookies); 2675 kfree(kmulti_link->mods); 2676 kfree(kmulti_link); 2677 } 2678 2679 static int bpf_kprobe_multi_link_fill_link_info(const struct bpf_link *link, 2680 struct bpf_link_info *info) 2681 { 2682 u64 __user *uaddrs = u64_to_user_ptr(info->kprobe_multi.addrs); 2683 struct bpf_kprobe_multi_link *kmulti_link; 2684 u32 ucount = info->kprobe_multi.count; 2685 int err = 0, i; 2686 2687 if (!uaddrs ^ !ucount) 2688 return -EINVAL; 2689 2690 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); 2691 info->kprobe_multi.count = kmulti_link->cnt; 2692 info->kprobe_multi.flags = kmulti_link->flags; 2693 info->kprobe_multi.missed = kmulti_link->fp.nmissed; 2694 2695 if (!uaddrs) 2696 return 0; 2697 if (ucount < kmulti_link->cnt) 2698 err = -ENOSPC; 2699 else 2700 ucount = kmulti_link->cnt; 2701 2702 if (kallsyms_show_value(current_cred())) { 2703 if (copy_to_user(uaddrs, kmulti_link->addrs, ucount * sizeof(u64))) 2704 return -EFAULT; 2705 } else { 2706 for (i = 0; i < ucount; i++) { 2707 if (put_user(0, uaddrs + i)) 2708 return -EFAULT; 2709 } 2710 } 2711 return err; 2712 } 2713 2714 static const struct bpf_link_ops bpf_kprobe_multi_link_lops = { 2715 .release = bpf_kprobe_multi_link_release, 2716 .dealloc = bpf_kprobe_multi_link_dealloc, 2717 .fill_link_info = bpf_kprobe_multi_link_fill_link_info, 2718 }; 2719 2720 static void bpf_kprobe_multi_cookie_swap(void *a, void *b, int size, const void *priv) 2721 { 2722 const struct bpf_kprobe_multi_link *link = priv; 2723 unsigned long *addr_a = a, *addr_b = b; 2724 u64 *cookie_a, *cookie_b; 2725 2726 cookie_a = link->cookies + (addr_a - link->addrs); 2727 cookie_b = link->cookies + (addr_b - link->addrs); 2728 2729 /* swap addr_a/addr_b and cookie_a/cookie_b values */ 2730 swap(*addr_a, *addr_b); 2731 swap(*cookie_a, *cookie_b); 2732 } 2733 2734 static int bpf_kprobe_multi_addrs_cmp(const void *a, const void *b) 2735 { 2736 const unsigned long *addr_a = a, *addr_b = b; 2737 2738 if (*addr_a == *addr_b) 2739 return 0; 2740 return *addr_a < *addr_b ? -1 : 1; 2741 } 2742 2743 static int bpf_kprobe_multi_cookie_cmp(const void *a, const void *b, const void *priv) 2744 { 2745 return bpf_kprobe_multi_addrs_cmp(a, b); 2746 } 2747 2748 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx) 2749 { 2750 struct bpf_kprobe_multi_run_ctx *run_ctx; 2751 struct bpf_kprobe_multi_link *link; 2752 u64 *cookie, entry_ip; 2753 unsigned long *addr; 2754 2755 if (WARN_ON_ONCE(!ctx)) 2756 return 0; 2757 run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, run_ctx); 2758 link = run_ctx->link; 2759 if (!link->cookies) 2760 return 0; 2761 entry_ip = run_ctx->entry_ip; 2762 addr = bsearch(&entry_ip, link->addrs, link->cnt, sizeof(entry_ip), 2763 bpf_kprobe_multi_addrs_cmp); 2764 if (!addr) 2765 return 0; 2766 cookie = link->cookies + (addr - link->addrs); 2767 return *cookie; 2768 } 2769 2770 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 2771 { 2772 struct bpf_kprobe_multi_run_ctx *run_ctx; 2773 2774 run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, run_ctx); 2775 return run_ctx->entry_ip; 2776 } 2777 2778 static int 2779 kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link, 2780 unsigned long entry_ip, struct pt_regs *regs) 2781 { 2782 struct bpf_kprobe_multi_run_ctx run_ctx = { 2783 .link = link, 2784 .entry_ip = entry_ip, 2785 }; 2786 struct bpf_run_ctx *old_run_ctx; 2787 int err; 2788 2789 if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) { 2790 bpf_prog_inc_misses_counter(link->link.prog); 2791 err = 0; 2792 goto out; 2793 } 2794 2795 migrate_disable(); 2796 rcu_read_lock(); 2797 old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx); 2798 err = bpf_prog_run(link->link.prog, regs); 2799 bpf_reset_run_ctx(old_run_ctx); 2800 rcu_read_unlock(); 2801 migrate_enable(); 2802 2803 out: 2804 __this_cpu_dec(bpf_prog_active); 2805 return err; 2806 } 2807 2808 static int 2809 kprobe_multi_link_handler(struct fprobe *fp, unsigned long fentry_ip, 2810 unsigned long ret_ip, struct pt_regs *regs, 2811 void *data) 2812 { 2813 struct bpf_kprobe_multi_link *link; 2814 2815 link = container_of(fp, struct bpf_kprobe_multi_link, fp); 2816 kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), regs); 2817 return 0; 2818 } 2819 2820 static void 2821 kprobe_multi_link_exit_handler(struct fprobe *fp, unsigned long fentry_ip, 2822 unsigned long ret_ip, struct pt_regs *regs, 2823 void *data) 2824 { 2825 struct bpf_kprobe_multi_link *link; 2826 2827 link = container_of(fp, struct bpf_kprobe_multi_link, fp); 2828 kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), regs); 2829 } 2830 2831 static int symbols_cmp_r(const void *a, const void *b, const void *priv) 2832 { 2833 const char **str_a = (const char **) a; 2834 const char **str_b = (const char **) b; 2835 2836 return strcmp(*str_a, *str_b); 2837 } 2838 2839 struct multi_symbols_sort { 2840 const char **funcs; 2841 u64 *cookies; 2842 }; 2843 2844 static void symbols_swap_r(void *a, void *b, int size, const void *priv) 2845 { 2846 const struct multi_symbols_sort *data = priv; 2847 const char **name_a = a, **name_b = b; 2848 2849 swap(*name_a, *name_b); 2850 2851 /* If defined, swap also related cookies. */ 2852 if (data->cookies) { 2853 u64 *cookie_a, *cookie_b; 2854 2855 cookie_a = data->cookies + (name_a - data->funcs); 2856 cookie_b = data->cookies + (name_b - data->funcs); 2857 swap(*cookie_a, *cookie_b); 2858 } 2859 } 2860 2861 struct modules_array { 2862 struct module **mods; 2863 int mods_cnt; 2864 int mods_cap; 2865 }; 2866 2867 static int add_module(struct modules_array *arr, struct module *mod) 2868 { 2869 struct module **mods; 2870 2871 if (arr->mods_cnt == arr->mods_cap) { 2872 arr->mods_cap = max(16, arr->mods_cap * 3 / 2); 2873 mods = krealloc_array(arr->mods, arr->mods_cap, sizeof(*mods), GFP_KERNEL); 2874 if (!mods) 2875 return -ENOMEM; 2876 arr->mods = mods; 2877 } 2878 2879 arr->mods[arr->mods_cnt] = mod; 2880 arr->mods_cnt++; 2881 return 0; 2882 } 2883 2884 static bool has_module(struct modules_array *arr, struct module *mod) 2885 { 2886 int i; 2887 2888 for (i = arr->mods_cnt - 1; i >= 0; i--) { 2889 if (arr->mods[i] == mod) 2890 return true; 2891 } 2892 return false; 2893 } 2894 2895 static int get_modules_for_addrs(struct module ***mods, unsigned long *addrs, u32 addrs_cnt) 2896 { 2897 struct modules_array arr = {}; 2898 u32 i, err = 0; 2899 2900 for (i = 0; i < addrs_cnt; i++) { 2901 struct module *mod; 2902 2903 preempt_disable(); 2904 mod = __module_address(addrs[i]); 2905 /* Either no module or we it's already stored */ 2906 if (!mod || has_module(&arr, mod)) { 2907 preempt_enable(); 2908 continue; 2909 } 2910 if (!try_module_get(mod)) 2911 err = -EINVAL; 2912 preempt_enable(); 2913 if (err) 2914 break; 2915 err = add_module(&arr, mod); 2916 if (err) { 2917 module_put(mod); 2918 break; 2919 } 2920 } 2921 2922 /* We return either err < 0 in case of error, ... */ 2923 if (err) { 2924 kprobe_multi_put_modules(arr.mods, arr.mods_cnt); 2925 kfree(arr.mods); 2926 return err; 2927 } 2928 2929 /* or number of modules found if everything is ok. */ 2930 *mods = arr.mods; 2931 return arr.mods_cnt; 2932 } 2933 2934 static int addrs_check_error_injection_list(unsigned long *addrs, u32 cnt) 2935 { 2936 u32 i; 2937 2938 for (i = 0; i < cnt; i++) { 2939 if (!within_error_injection_list(addrs[i])) 2940 return -EINVAL; 2941 } 2942 return 0; 2943 } 2944 2945 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 2946 { 2947 struct bpf_kprobe_multi_link *link = NULL; 2948 struct bpf_link_primer link_primer; 2949 void __user *ucookies; 2950 unsigned long *addrs; 2951 u32 flags, cnt, size; 2952 void __user *uaddrs; 2953 u64 *cookies = NULL; 2954 void __user *usyms; 2955 int err; 2956 2957 /* no support for 32bit archs yet */ 2958 if (sizeof(u64) != sizeof(void *)) 2959 return -EOPNOTSUPP; 2960 2961 if (prog->expected_attach_type != BPF_TRACE_KPROBE_MULTI) 2962 return -EINVAL; 2963 2964 flags = attr->link_create.kprobe_multi.flags; 2965 if (flags & ~BPF_F_KPROBE_MULTI_RETURN) 2966 return -EINVAL; 2967 2968 uaddrs = u64_to_user_ptr(attr->link_create.kprobe_multi.addrs); 2969 usyms = u64_to_user_ptr(attr->link_create.kprobe_multi.syms); 2970 if (!!uaddrs == !!usyms) 2971 return -EINVAL; 2972 2973 cnt = attr->link_create.kprobe_multi.cnt; 2974 if (!cnt) 2975 return -EINVAL; 2976 if (cnt > MAX_KPROBE_MULTI_CNT) 2977 return -E2BIG; 2978 2979 size = cnt * sizeof(*addrs); 2980 addrs = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL); 2981 if (!addrs) 2982 return -ENOMEM; 2983 2984 ucookies = u64_to_user_ptr(attr->link_create.kprobe_multi.cookies); 2985 if (ucookies) { 2986 cookies = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL); 2987 if (!cookies) { 2988 err = -ENOMEM; 2989 goto error; 2990 } 2991 if (copy_from_user(cookies, ucookies, size)) { 2992 err = -EFAULT; 2993 goto error; 2994 } 2995 } 2996 2997 if (uaddrs) { 2998 if (copy_from_user(addrs, uaddrs, size)) { 2999 err = -EFAULT; 3000 goto error; 3001 } 3002 } else { 3003 struct multi_symbols_sort data = { 3004 .cookies = cookies, 3005 }; 3006 struct user_syms us; 3007 3008 err = copy_user_syms(&us, usyms, cnt); 3009 if (err) 3010 goto error; 3011 3012 if (cookies) 3013 data.funcs = us.syms; 3014 3015 sort_r(us.syms, cnt, sizeof(*us.syms), symbols_cmp_r, 3016 symbols_swap_r, &data); 3017 3018 err = ftrace_lookup_symbols(us.syms, cnt, addrs); 3019 free_user_syms(&us); 3020 if (err) 3021 goto error; 3022 } 3023 3024 if (prog->kprobe_override && addrs_check_error_injection_list(addrs, cnt)) { 3025 err = -EINVAL; 3026 goto error; 3027 } 3028 3029 link = kzalloc(sizeof(*link), GFP_KERNEL); 3030 if (!link) { 3031 err = -ENOMEM; 3032 goto error; 3033 } 3034 3035 bpf_link_init(&link->link, BPF_LINK_TYPE_KPROBE_MULTI, 3036 &bpf_kprobe_multi_link_lops, prog); 3037 3038 err = bpf_link_prime(&link->link, &link_primer); 3039 if (err) 3040 goto error; 3041 3042 if (flags & BPF_F_KPROBE_MULTI_RETURN) 3043 link->fp.exit_handler = kprobe_multi_link_exit_handler; 3044 else 3045 link->fp.entry_handler = kprobe_multi_link_handler; 3046 3047 link->addrs = addrs; 3048 link->cookies = cookies; 3049 link->cnt = cnt; 3050 link->flags = flags; 3051 3052 if (cookies) { 3053 /* 3054 * Sorting addresses will trigger sorting cookies as well 3055 * (check bpf_kprobe_multi_cookie_swap). This way we can 3056 * find cookie based on the address in bpf_get_attach_cookie 3057 * helper. 3058 */ 3059 sort_r(addrs, cnt, sizeof(*addrs), 3060 bpf_kprobe_multi_cookie_cmp, 3061 bpf_kprobe_multi_cookie_swap, 3062 link); 3063 } 3064 3065 err = get_modules_for_addrs(&link->mods, addrs, cnt); 3066 if (err < 0) { 3067 bpf_link_cleanup(&link_primer); 3068 return err; 3069 } 3070 link->mods_cnt = err; 3071 3072 err = register_fprobe_ips(&link->fp, addrs, cnt); 3073 if (err) { 3074 kprobe_multi_put_modules(link->mods, link->mods_cnt); 3075 bpf_link_cleanup(&link_primer); 3076 return err; 3077 } 3078 3079 return bpf_link_settle(&link_primer); 3080 3081 error: 3082 kfree(link); 3083 kvfree(addrs); 3084 kvfree(cookies); 3085 return err; 3086 } 3087 #else /* !CONFIG_FPROBE */ 3088 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 3089 { 3090 return -EOPNOTSUPP; 3091 } 3092 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx) 3093 { 3094 return 0; 3095 } 3096 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 3097 { 3098 return 0; 3099 } 3100 #endif 3101 3102 #ifdef CONFIG_UPROBES 3103 struct bpf_uprobe_multi_link; 3104 3105 struct bpf_uprobe { 3106 struct bpf_uprobe_multi_link *link; 3107 loff_t offset; 3108 unsigned long ref_ctr_offset; 3109 u64 cookie; 3110 struct uprobe_consumer consumer; 3111 }; 3112 3113 struct bpf_uprobe_multi_link { 3114 struct path path; 3115 struct bpf_link link; 3116 u32 cnt; 3117 u32 flags; 3118 struct bpf_uprobe *uprobes; 3119 struct task_struct *task; 3120 }; 3121 3122 struct bpf_uprobe_multi_run_ctx { 3123 struct bpf_run_ctx run_ctx; 3124 unsigned long entry_ip; 3125 struct bpf_uprobe *uprobe; 3126 }; 3127 3128 static void bpf_uprobe_unregister(struct path *path, struct bpf_uprobe *uprobes, 3129 u32 cnt) 3130 { 3131 u32 i; 3132 3133 for (i = 0; i < cnt; i++) { 3134 uprobe_unregister(d_real_inode(path->dentry), uprobes[i].offset, 3135 &uprobes[i].consumer); 3136 } 3137 } 3138 3139 static void bpf_uprobe_multi_link_release(struct bpf_link *link) 3140 { 3141 struct bpf_uprobe_multi_link *umulti_link; 3142 3143 umulti_link = container_of(link, struct bpf_uprobe_multi_link, link); 3144 bpf_uprobe_unregister(&umulti_link->path, umulti_link->uprobes, umulti_link->cnt); 3145 } 3146 3147 static void bpf_uprobe_multi_link_dealloc(struct bpf_link *link) 3148 { 3149 struct bpf_uprobe_multi_link *umulti_link; 3150 3151 umulti_link = container_of(link, struct bpf_uprobe_multi_link, link); 3152 if (umulti_link->task) 3153 put_task_struct(umulti_link->task); 3154 path_put(&umulti_link->path); 3155 kvfree(umulti_link->uprobes); 3156 kfree(umulti_link); 3157 } 3158 3159 static int bpf_uprobe_multi_link_fill_link_info(const struct bpf_link *link, 3160 struct bpf_link_info *info) 3161 { 3162 u64 __user *uref_ctr_offsets = u64_to_user_ptr(info->uprobe_multi.ref_ctr_offsets); 3163 u64 __user *ucookies = u64_to_user_ptr(info->uprobe_multi.cookies); 3164 u64 __user *uoffsets = u64_to_user_ptr(info->uprobe_multi.offsets); 3165 u64 __user *upath = u64_to_user_ptr(info->uprobe_multi.path); 3166 u32 upath_size = info->uprobe_multi.path_size; 3167 struct bpf_uprobe_multi_link *umulti_link; 3168 u32 ucount = info->uprobe_multi.count; 3169 int err = 0, i; 3170 long left; 3171 3172 if (!upath ^ !upath_size) 3173 return -EINVAL; 3174 3175 if ((uoffsets || uref_ctr_offsets || ucookies) && !ucount) 3176 return -EINVAL; 3177 3178 umulti_link = container_of(link, struct bpf_uprobe_multi_link, link); 3179 info->uprobe_multi.count = umulti_link->cnt; 3180 info->uprobe_multi.flags = umulti_link->flags; 3181 info->uprobe_multi.pid = umulti_link->task ? 3182 task_pid_nr_ns(umulti_link->task, task_active_pid_ns(current)) : 0; 3183 3184 if (upath) { 3185 char *p, *buf; 3186 3187 upath_size = min_t(u32, upath_size, PATH_MAX); 3188 3189 buf = kmalloc(upath_size, GFP_KERNEL); 3190 if (!buf) 3191 return -ENOMEM; 3192 p = d_path(&umulti_link->path, buf, upath_size); 3193 if (IS_ERR(p)) { 3194 kfree(buf); 3195 return PTR_ERR(p); 3196 } 3197 upath_size = buf + upath_size - p; 3198 left = copy_to_user(upath, p, upath_size); 3199 kfree(buf); 3200 if (left) 3201 return -EFAULT; 3202 info->uprobe_multi.path_size = upath_size; 3203 } 3204 3205 if (!uoffsets && !ucookies && !uref_ctr_offsets) 3206 return 0; 3207 3208 if (ucount < umulti_link->cnt) 3209 err = -ENOSPC; 3210 else 3211 ucount = umulti_link->cnt; 3212 3213 for (i = 0; i < ucount; i++) { 3214 if (uoffsets && 3215 put_user(umulti_link->uprobes[i].offset, uoffsets + i)) 3216 return -EFAULT; 3217 if (uref_ctr_offsets && 3218 put_user(umulti_link->uprobes[i].ref_ctr_offset, uref_ctr_offsets + i)) 3219 return -EFAULT; 3220 if (ucookies && 3221 put_user(umulti_link->uprobes[i].cookie, ucookies + i)) 3222 return -EFAULT; 3223 } 3224 3225 return err; 3226 } 3227 3228 static const struct bpf_link_ops bpf_uprobe_multi_link_lops = { 3229 .release = bpf_uprobe_multi_link_release, 3230 .dealloc = bpf_uprobe_multi_link_dealloc, 3231 .fill_link_info = bpf_uprobe_multi_link_fill_link_info, 3232 }; 3233 3234 static int uprobe_prog_run(struct bpf_uprobe *uprobe, 3235 unsigned long entry_ip, 3236 struct pt_regs *regs) 3237 { 3238 struct bpf_uprobe_multi_link *link = uprobe->link; 3239 struct bpf_uprobe_multi_run_ctx run_ctx = { 3240 .entry_ip = entry_ip, 3241 .uprobe = uprobe, 3242 }; 3243 struct bpf_prog *prog = link->link.prog; 3244 bool sleepable = prog->aux->sleepable; 3245 struct bpf_run_ctx *old_run_ctx; 3246 int err = 0; 3247 3248 if (link->task && current != link->task) 3249 return 0; 3250 3251 if (sleepable) 3252 rcu_read_lock_trace(); 3253 else 3254 rcu_read_lock(); 3255 3256 migrate_disable(); 3257 3258 old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx); 3259 err = bpf_prog_run(link->link.prog, regs); 3260 bpf_reset_run_ctx(old_run_ctx); 3261 3262 migrate_enable(); 3263 3264 if (sleepable) 3265 rcu_read_unlock_trace(); 3266 else 3267 rcu_read_unlock(); 3268 return err; 3269 } 3270 3271 static bool 3272 uprobe_multi_link_filter(struct uprobe_consumer *con, enum uprobe_filter_ctx ctx, 3273 struct mm_struct *mm) 3274 { 3275 struct bpf_uprobe *uprobe; 3276 3277 uprobe = container_of(con, struct bpf_uprobe, consumer); 3278 return uprobe->link->task->mm == mm; 3279 } 3280 3281 static int 3282 uprobe_multi_link_handler(struct uprobe_consumer *con, struct pt_regs *regs) 3283 { 3284 struct bpf_uprobe *uprobe; 3285 3286 uprobe = container_of(con, struct bpf_uprobe, consumer); 3287 return uprobe_prog_run(uprobe, instruction_pointer(regs), regs); 3288 } 3289 3290 static int 3291 uprobe_multi_link_ret_handler(struct uprobe_consumer *con, unsigned long func, struct pt_regs *regs) 3292 { 3293 struct bpf_uprobe *uprobe; 3294 3295 uprobe = container_of(con, struct bpf_uprobe, consumer); 3296 return uprobe_prog_run(uprobe, func, regs); 3297 } 3298 3299 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 3300 { 3301 struct bpf_uprobe_multi_run_ctx *run_ctx; 3302 3303 run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx, run_ctx); 3304 return run_ctx->entry_ip; 3305 } 3306 3307 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx) 3308 { 3309 struct bpf_uprobe_multi_run_ctx *run_ctx; 3310 3311 run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx, run_ctx); 3312 return run_ctx->uprobe->cookie; 3313 } 3314 3315 int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 3316 { 3317 struct bpf_uprobe_multi_link *link = NULL; 3318 unsigned long __user *uref_ctr_offsets; 3319 struct bpf_link_primer link_primer; 3320 struct bpf_uprobe *uprobes = NULL; 3321 struct task_struct *task = NULL; 3322 unsigned long __user *uoffsets; 3323 u64 __user *ucookies; 3324 void __user *upath; 3325 u32 flags, cnt, i; 3326 struct path path; 3327 char *name; 3328 pid_t pid; 3329 int err; 3330 3331 /* no support for 32bit archs yet */ 3332 if (sizeof(u64) != sizeof(void *)) 3333 return -EOPNOTSUPP; 3334 3335 if (prog->expected_attach_type != BPF_TRACE_UPROBE_MULTI) 3336 return -EINVAL; 3337 3338 flags = attr->link_create.uprobe_multi.flags; 3339 if (flags & ~BPF_F_UPROBE_MULTI_RETURN) 3340 return -EINVAL; 3341 3342 /* 3343 * path, offsets and cnt are mandatory, 3344 * ref_ctr_offsets and cookies are optional 3345 */ 3346 upath = u64_to_user_ptr(attr->link_create.uprobe_multi.path); 3347 uoffsets = u64_to_user_ptr(attr->link_create.uprobe_multi.offsets); 3348 cnt = attr->link_create.uprobe_multi.cnt; 3349 3350 if (!upath || !uoffsets || !cnt) 3351 return -EINVAL; 3352 if (cnt > MAX_UPROBE_MULTI_CNT) 3353 return -E2BIG; 3354 3355 uref_ctr_offsets = u64_to_user_ptr(attr->link_create.uprobe_multi.ref_ctr_offsets); 3356 ucookies = u64_to_user_ptr(attr->link_create.uprobe_multi.cookies); 3357 3358 name = strndup_user(upath, PATH_MAX); 3359 if (IS_ERR(name)) { 3360 err = PTR_ERR(name); 3361 return err; 3362 } 3363 3364 err = kern_path(name, LOOKUP_FOLLOW, &path); 3365 kfree(name); 3366 if (err) 3367 return err; 3368 3369 if (!d_is_reg(path.dentry)) { 3370 err = -EBADF; 3371 goto error_path_put; 3372 } 3373 3374 pid = attr->link_create.uprobe_multi.pid; 3375 if (pid) { 3376 rcu_read_lock(); 3377 task = get_pid_task(find_vpid(pid), PIDTYPE_PID); 3378 rcu_read_unlock(); 3379 if (!task) { 3380 err = -ESRCH; 3381 goto error_path_put; 3382 } 3383 } 3384 3385 err = -ENOMEM; 3386 3387 link = kzalloc(sizeof(*link), GFP_KERNEL); 3388 uprobes = kvcalloc(cnt, sizeof(*uprobes), GFP_KERNEL); 3389 3390 if (!uprobes || !link) 3391 goto error_free; 3392 3393 for (i = 0; i < cnt; i++) { 3394 if (__get_user(uprobes[i].offset, uoffsets + i)) { 3395 err = -EFAULT; 3396 goto error_free; 3397 } 3398 if (uprobes[i].offset < 0) { 3399 err = -EINVAL; 3400 goto error_free; 3401 } 3402 if (uref_ctr_offsets && __get_user(uprobes[i].ref_ctr_offset, uref_ctr_offsets + i)) { 3403 err = -EFAULT; 3404 goto error_free; 3405 } 3406 if (ucookies && __get_user(uprobes[i].cookie, ucookies + i)) { 3407 err = -EFAULT; 3408 goto error_free; 3409 } 3410 3411 uprobes[i].link = link; 3412 3413 if (flags & BPF_F_UPROBE_MULTI_RETURN) 3414 uprobes[i].consumer.ret_handler = uprobe_multi_link_ret_handler; 3415 else 3416 uprobes[i].consumer.handler = uprobe_multi_link_handler; 3417 3418 if (pid) 3419 uprobes[i].consumer.filter = uprobe_multi_link_filter; 3420 } 3421 3422 link->cnt = cnt; 3423 link->uprobes = uprobes; 3424 link->path = path; 3425 link->task = task; 3426 link->flags = flags; 3427 3428 bpf_link_init(&link->link, BPF_LINK_TYPE_UPROBE_MULTI, 3429 &bpf_uprobe_multi_link_lops, prog); 3430 3431 for (i = 0; i < cnt; i++) { 3432 err = uprobe_register_refctr(d_real_inode(link->path.dentry), 3433 uprobes[i].offset, 3434 uprobes[i].ref_ctr_offset, 3435 &uprobes[i].consumer); 3436 if (err) { 3437 bpf_uprobe_unregister(&path, uprobes, i); 3438 goto error_free; 3439 } 3440 } 3441 3442 err = bpf_link_prime(&link->link, &link_primer); 3443 if (err) 3444 goto error_free; 3445 3446 return bpf_link_settle(&link_primer); 3447 3448 error_free: 3449 kvfree(uprobes); 3450 kfree(link); 3451 if (task) 3452 put_task_struct(task); 3453 error_path_put: 3454 path_put(&path); 3455 return err; 3456 } 3457 #else /* !CONFIG_UPROBES */ 3458 int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 3459 { 3460 return -EOPNOTSUPP; 3461 } 3462 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx) 3463 { 3464 return 0; 3465 } 3466 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 3467 { 3468 return 0; 3469 } 3470 #endif /* CONFIG_UPROBES */ 3471