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 27 #include <net/bpf_sk_storage.h> 28 29 #include <uapi/linux/bpf.h> 30 #include <uapi/linux/btf.h> 31 32 #include <asm/tlb.h> 33 34 #include "trace_probe.h" 35 #include "trace.h" 36 37 #define CREATE_TRACE_POINTS 38 #include "bpf_trace.h" 39 40 #define bpf_event_rcu_dereference(p) \ 41 rcu_dereference_protected(p, lockdep_is_held(&bpf_event_mutex)) 42 43 #ifdef CONFIG_MODULES 44 struct bpf_trace_module { 45 struct module *module; 46 struct list_head list; 47 }; 48 49 static LIST_HEAD(bpf_trace_modules); 50 static DEFINE_MUTEX(bpf_module_mutex); 51 52 static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name) 53 { 54 struct bpf_raw_event_map *btp, *ret = NULL; 55 struct bpf_trace_module *btm; 56 unsigned int i; 57 58 mutex_lock(&bpf_module_mutex); 59 list_for_each_entry(btm, &bpf_trace_modules, list) { 60 for (i = 0; i < btm->module->num_bpf_raw_events; ++i) { 61 btp = &btm->module->bpf_raw_events[i]; 62 if (!strcmp(btp->tp->name, name)) { 63 if (try_module_get(btm->module)) 64 ret = btp; 65 goto out; 66 } 67 } 68 } 69 out: 70 mutex_unlock(&bpf_module_mutex); 71 return ret; 72 } 73 #else 74 static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name) 75 { 76 return NULL; 77 } 78 #endif /* CONFIG_MODULES */ 79 80 u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); 81 u64 bpf_get_stack(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); 82 83 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size, 84 u64 flags, const struct btf **btf, 85 s32 *btf_id); 86 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx); 87 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx); 88 89 /** 90 * trace_call_bpf - invoke BPF program 91 * @call: tracepoint event 92 * @ctx: opaque context pointer 93 * 94 * kprobe handlers execute BPF programs via this helper. 95 * Can be used from static tracepoints in the future. 96 * 97 * Return: BPF programs always return an integer which is interpreted by 98 * kprobe handler as: 99 * 0 - return from kprobe (event is filtered out) 100 * 1 - store kprobe event into ring buffer 101 * Other values are reserved and currently alias to 1 102 */ 103 unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx) 104 { 105 unsigned int ret; 106 107 cant_sleep(); 108 109 if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) { 110 /* 111 * since some bpf program is already running on this cpu, 112 * don't call into another bpf program (same or different) 113 * and don't send kprobe event into ring-buffer, 114 * so return zero here 115 */ 116 ret = 0; 117 goto out; 118 } 119 120 /* 121 * Instead of moving rcu_read_lock/rcu_dereference/rcu_read_unlock 122 * to all call sites, we did a bpf_prog_array_valid() there to check 123 * whether call->prog_array is empty or not, which is 124 * a heuristic to speed up execution. 125 * 126 * If bpf_prog_array_valid() fetched prog_array was 127 * non-NULL, we go into trace_call_bpf() and do the actual 128 * proper rcu_dereference() under RCU lock. 129 * If it turns out that prog_array is NULL then, we bail out. 130 * For the opposite, if the bpf_prog_array_valid() fetched pointer 131 * was NULL, you'll skip the prog_array with the risk of missing 132 * out of events when it was updated in between this and the 133 * rcu_dereference() which is accepted risk. 134 */ 135 rcu_read_lock(); 136 ret = bpf_prog_run_array(rcu_dereference(call->prog_array), 137 ctx, bpf_prog_run); 138 rcu_read_unlock(); 139 140 out: 141 __this_cpu_dec(bpf_prog_active); 142 143 return ret; 144 } 145 146 #ifdef CONFIG_BPF_KPROBE_OVERRIDE 147 BPF_CALL_2(bpf_override_return, struct pt_regs *, regs, unsigned long, rc) 148 { 149 regs_set_return_value(regs, rc); 150 override_function_with_return(regs); 151 return 0; 152 } 153 154 static const struct bpf_func_proto bpf_override_return_proto = { 155 .func = bpf_override_return, 156 .gpl_only = true, 157 .ret_type = RET_INTEGER, 158 .arg1_type = ARG_PTR_TO_CTX, 159 .arg2_type = ARG_ANYTHING, 160 }; 161 #endif 162 163 static __always_inline int 164 bpf_probe_read_user_common(void *dst, u32 size, const void __user *unsafe_ptr) 165 { 166 int ret; 167 168 ret = copy_from_user_nofault(dst, unsafe_ptr, size); 169 if (unlikely(ret < 0)) 170 memset(dst, 0, size); 171 return ret; 172 } 173 174 BPF_CALL_3(bpf_probe_read_user, void *, dst, u32, size, 175 const void __user *, unsafe_ptr) 176 { 177 return bpf_probe_read_user_common(dst, size, unsafe_ptr); 178 } 179 180 const struct bpf_func_proto bpf_probe_read_user_proto = { 181 .func = bpf_probe_read_user, 182 .gpl_only = true, 183 .ret_type = RET_INTEGER, 184 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 185 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 186 .arg3_type = ARG_ANYTHING, 187 }; 188 189 static __always_inline int 190 bpf_probe_read_user_str_common(void *dst, u32 size, 191 const void __user *unsafe_ptr) 192 { 193 int ret; 194 195 /* 196 * NB: We rely on strncpy_from_user() not copying junk past the NUL 197 * terminator into `dst`. 198 * 199 * strncpy_from_user() does long-sized strides in the fast path. If the 200 * strncpy does not mask out the bytes after the NUL in `unsafe_ptr`, 201 * then there could be junk after the NUL in `dst`. If user takes `dst` 202 * and keys a hash map with it, then semantically identical strings can 203 * occupy multiple entries in the map. 204 */ 205 ret = strncpy_from_user_nofault(dst, unsafe_ptr, size); 206 if (unlikely(ret < 0)) 207 memset(dst, 0, size); 208 return ret; 209 } 210 211 BPF_CALL_3(bpf_probe_read_user_str, void *, dst, u32, size, 212 const void __user *, unsafe_ptr) 213 { 214 return bpf_probe_read_user_str_common(dst, size, unsafe_ptr); 215 } 216 217 const struct bpf_func_proto bpf_probe_read_user_str_proto = { 218 .func = bpf_probe_read_user_str, 219 .gpl_only = true, 220 .ret_type = RET_INTEGER, 221 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 222 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 223 .arg3_type = ARG_ANYTHING, 224 }; 225 226 static __always_inline int 227 bpf_probe_read_kernel_common(void *dst, u32 size, const void *unsafe_ptr) 228 { 229 int ret; 230 231 ret = copy_from_kernel_nofault(dst, unsafe_ptr, size); 232 if (unlikely(ret < 0)) 233 memset(dst, 0, size); 234 return ret; 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 static DEFINE_RAW_SPINLOCK(trace_printk_lock); 373 374 #define MAX_TRACE_PRINTK_VARARGS 3 375 #define BPF_TRACE_PRINTK_SIZE 1024 376 377 BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1, 378 u64, arg2, u64, arg3) 379 { 380 u64 args[MAX_TRACE_PRINTK_VARARGS] = { arg1, arg2, arg3 }; 381 u32 *bin_args; 382 static char buf[BPF_TRACE_PRINTK_SIZE]; 383 unsigned long flags; 384 int ret; 385 386 ret = bpf_bprintf_prepare(fmt, fmt_size, args, &bin_args, 387 MAX_TRACE_PRINTK_VARARGS); 388 if (ret < 0) 389 return ret; 390 391 raw_spin_lock_irqsave(&trace_printk_lock, flags); 392 ret = bstr_printf(buf, sizeof(buf), fmt, bin_args); 393 394 trace_bpf_trace_printk(buf); 395 raw_spin_unlock_irqrestore(&trace_printk_lock, flags); 396 397 bpf_bprintf_cleanup(); 398 399 return ret; 400 } 401 402 static const struct bpf_func_proto bpf_trace_printk_proto = { 403 .func = bpf_trace_printk, 404 .gpl_only = true, 405 .ret_type = RET_INTEGER, 406 .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY, 407 .arg2_type = ARG_CONST_SIZE, 408 }; 409 410 static void __set_printk_clr_event(void) 411 { 412 /* 413 * This program might be calling bpf_trace_printk, 414 * so enable the associated bpf_trace/bpf_trace_printk event. 415 * Repeat this each time as it is possible a user has 416 * disabled bpf_trace_printk events. By loading a program 417 * calling bpf_trace_printk() however the user has expressed 418 * the intent to see such events. 419 */ 420 if (trace_set_clr_event("bpf_trace", "bpf_trace_printk", 1)) 421 pr_warn_ratelimited("could not enable bpf_trace_printk events"); 422 } 423 424 const struct bpf_func_proto *bpf_get_trace_printk_proto(void) 425 { 426 __set_printk_clr_event(); 427 return &bpf_trace_printk_proto; 428 } 429 430 BPF_CALL_4(bpf_trace_vprintk, char *, fmt, u32, fmt_size, const void *, data, 431 u32, data_len) 432 { 433 static char buf[BPF_TRACE_PRINTK_SIZE]; 434 unsigned long flags; 435 int ret, num_args; 436 u32 *bin_args; 437 438 if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 || 439 (data_len && !data)) 440 return -EINVAL; 441 num_args = data_len / 8; 442 443 ret = bpf_bprintf_prepare(fmt, fmt_size, data, &bin_args, num_args); 444 if (ret < 0) 445 return ret; 446 447 raw_spin_lock_irqsave(&trace_printk_lock, flags); 448 ret = bstr_printf(buf, sizeof(buf), fmt, bin_args); 449 450 trace_bpf_trace_printk(buf); 451 raw_spin_unlock_irqrestore(&trace_printk_lock, flags); 452 453 bpf_bprintf_cleanup(); 454 455 return ret; 456 } 457 458 static const struct bpf_func_proto bpf_trace_vprintk_proto = { 459 .func = bpf_trace_vprintk, 460 .gpl_only = true, 461 .ret_type = RET_INTEGER, 462 .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY, 463 .arg2_type = ARG_CONST_SIZE, 464 .arg3_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY, 465 .arg4_type = ARG_CONST_SIZE_OR_ZERO, 466 }; 467 468 const struct bpf_func_proto *bpf_get_trace_vprintk_proto(void) 469 { 470 __set_printk_clr_event(); 471 return &bpf_trace_vprintk_proto; 472 } 473 474 BPF_CALL_5(bpf_seq_printf, struct seq_file *, m, char *, fmt, u32, fmt_size, 475 const void *, data, u32, data_len) 476 { 477 int err, num_args; 478 u32 *bin_args; 479 480 if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 || 481 (data_len && !data)) 482 return -EINVAL; 483 num_args = data_len / 8; 484 485 err = bpf_bprintf_prepare(fmt, fmt_size, data, &bin_args, num_args); 486 if (err < 0) 487 return err; 488 489 seq_bprintf(m, fmt, bin_args); 490 491 bpf_bprintf_cleanup(); 492 493 return seq_has_overflowed(m) ? -EOVERFLOW : 0; 494 } 495 496 BTF_ID_LIST_SINGLE(btf_seq_file_ids, struct, seq_file) 497 498 static const struct bpf_func_proto bpf_seq_printf_proto = { 499 .func = bpf_seq_printf, 500 .gpl_only = true, 501 .ret_type = RET_INTEGER, 502 .arg1_type = ARG_PTR_TO_BTF_ID, 503 .arg1_btf_id = &btf_seq_file_ids[0], 504 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 505 .arg3_type = ARG_CONST_SIZE, 506 .arg4_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY, 507 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 508 }; 509 510 BPF_CALL_3(bpf_seq_write, struct seq_file *, m, const void *, data, u32, len) 511 { 512 return seq_write(m, data, len) ? -EOVERFLOW : 0; 513 } 514 515 static const struct bpf_func_proto bpf_seq_write_proto = { 516 .func = bpf_seq_write, 517 .gpl_only = true, 518 .ret_type = RET_INTEGER, 519 .arg1_type = ARG_PTR_TO_BTF_ID, 520 .arg1_btf_id = &btf_seq_file_ids[0], 521 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 522 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 523 }; 524 525 BPF_CALL_4(bpf_seq_printf_btf, struct seq_file *, m, struct btf_ptr *, ptr, 526 u32, btf_ptr_size, u64, flags) 527 { 528 const struct btf *btf; 529 s32 btf_id; 530 int ret; 531 532 ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id); 533 if (ret) 534 return ret; 535 536 return btf_type_seq_show_flags(btf, btf_id, ptr->ptr, m, flags); 537 } 538 539 static const struct bpf_func_proto bpf_seq_printf_btf_proto = { 540 .func = bpf_seq_printf_btf, 541 .gpl_only = true, 542 .ret_type = RET_INTEGER, 543 .arg1_type = ARG_PTR_TO_BTF_ID, 544 .arg1_btf_id = &btf_seq_file_ids[0], 545 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 546 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 547 .arg4_type = ARG_ANYTHING, 548 }; 549 550 static __always_inline int 551 get_map_perf_counter(struct bpf_map *map, u64 flags, 552 u64 *value, u64 *enabled, u64 *running) 553 { 554 struct bpf_array *array = container_of(map, struct bpf_array, map); 555 unsigned int cpu = smp_processor_id(); 556 u64 index = flags & BPF_F_INDEX_MASK; 557 struct bpf_event_entry *ee; 558 559 if (unlikely(flags & ~(BPF_F_INDEX_MASK))) 560 return -EINVAL; 561 if (index == BPF_F_CURRENT_CPU) 562 index = cpu; 563 if (unlikely(index >= array->map.max_entries)) 564 return -E2BIG; 565 566 ee = READ_ONCE(array->ptrs[index]); 567 if (!ee) 568 return -ENOENT; 569 570 return perf_event_read_local(ee->event, value, enabled, running); 571 } 572 573 BPF_CALL_2(bpf_perf_event_read, struct bpf_map *, map, u64, flags) 574 { 575 u64 value = 0; 576 int err; 577 578 err = get_map_perf_counter(map, flags, &value, NULL, NULL); 579 /* 580 * this api is ugly since we miss [-22..-2] range of valid 581 * counter values, but that's uapi 582 */ 583 if (err) 584 return err; 585 return value; 586 } 587 588 static const struct bpf_func_proto bpf_perf_event_read_proto = { 589 .func = bpf_perf_event_read, 590 .gpl_only = true, 591 .ret_type = RET_INTEGER, 592 .arg1_type = ARG_CONST_MAP_PTR, 593 .arg2_type = ARG_ANYTHING, 594 }; 595 596 BPF_CALL_4(bpf_perf_event_read_value, struct bpf_map *, map, u64, flags, 597 struct bpf_perf_event_value *, buf, u32, size) 598 { 599 int err = -EINVAL; 600 601 if (unlikely(size != sizeof(struct bpf_perf_event_value))) 602 goto clear; 603 err = get_map_perf_counter(map, flags, &buf->counter, &buf->enabled, 604 &buf->running); 605 if (unlikely(err)) 606 goto clear; 607 return 0; 608 clear: 609 memset(buf, 0, size); 610 return err; 611 } 612 613 static const struct bpf_func_proto bpf_perf_event_read_value_proto = { 614 .func = bpf_perf_event_read_value, 615 .gpl_only = true, 616 .ret_type = RET_INTEGER, 617 .arg1_type = ARG_CONST_MAP_PTR, 618 .arg2_type = ARG_ANYTHING, 619 .arg3_type = ARG_PTR_TO_UNINIT_MEM, 620 .arg4_type = ARG_CONST_SIZE, 621 }; 622 623 static __always_inline u64 624 __bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map, 625 u64 flags, struct perf_sample_data *sd) 626 { 627 struct bpf_array *array = container_of(map, struct bpf_array, map); 628 unsigned int cpu = smp_processor_id(); 629 u64 index = flags & BPF_F_INDEX_MASK; 630 struct bpf_event_entry *ee; 631 struct perf_event *event; 632 633 if (index == BPF_F_CURRENT_CPU) 634 index = cpu; 635 if (unlikely(index >= array->map.max_entries)) 636 return -E2BIG; 637 638 ee = READ_ONCE(array->ptrs[index]); 639 if (!ee) 640 return -ENOENT; 641 642 event = ee->event; 643 if (unlikely(event->attr.type != PERF_TYPE_SOFTWARE || 644 event->attr.config != PERF_COUNT_SW_BPF_OUTPUT)) 645 return -EINVAL; 646 647 if (unlikely(event->oncpu != cpu)) 648 return -EOPNOTSUPP; 649 650 return perf_event_output(event, sd, regs); 651 } 652 653 /* 654 * Support executing tracepoints in normal, irq, and nmi context that each call 655 * bpf_perf_event_output 656 */ 657 struct bpf_trace_sample_data { 658 struct perf_sample_data sds[3]; 659 }; 660 661 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_trace_sds); 662 static DEFINE_PER_CPU(int, bpf_trace_nest_level); 663 BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map, 664 u64, flags, void *, data, u64, size) 665 { 666 struct bpf_trace_sample_data *sds = this_cpu_ptr(&bpf_trace_sds); 667 int nest_level = this_cpu_inc_return(bpf_trace_nest_level); 668 struct perf_raw_record raw = { 669 .frag = { 670 .size = size, 671 .data = data, 672 }, 673 }; 674 struct perf_sample_data *sd; 675 int err; 676 677 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(sds->sds))) { 678 err = -EBUSY; 679 goto out; 680 } 681 682 sd = &sds->sds[nest_level - 1]; 683 684 if (unlikely(flags & ~(BPF_F_INDEX_MASK))) { 685 err = -EINVAL; 686 goto out; 687 } 688 689 perf_sample_data_init(sd, 0, 0); 690 sd->raw = &raw; 691 sd->sample_flags |= PERF_SAMPLE_RAW; 692 693 err = __bpf_perf_event_output(regs, map, flags, sd); 694 695 out: 696 this_cpu_dec(bpf_trace_nest_level); 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 int nest_level = this_cpu_inc_return(bpf_event_output_nest_level); 722 struct perf_raw_frag frag = { 723 .copy = ctx_copy, 724 .size = ctx_size, 725 .data = ctx, 726 }; 727 struct perf_raw_record raw = { 728 .frag = { 729 { 730 .next = ctx_size ? &frag : NULL, 731 }, 732 .size = meta_size, 733 .data = meta, 734 }, 735 }; 736 struct perf_sample_data *sd; 737 struct pt_regs *regs; 738 u64 ret; 739 740 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(bpf_misc_sds.sds))) { 741 ret = -EBUSY; 742 goto out; 743 } 744 sd = this_cpu_ptr(&bpf_misc_sds.sds[nest_level - 1]); 745 regs = this_cpu_ptr(&bpf_pt_regs.regs[nest_level - 1]); 746 747 perf_fetch_caller_regs(regs); 748 perf_sample_data_init(sd, 0, 0); 749 sd->raw = &raw; 750 sd->sample_flags |= PERF_SAMPLE_RAW; 751 752 ret = __bpf_perf_event_output(regs, map, flags, sd); 753 out: 754 this_cpu_dec(bpf_event_output_nest_level); 755 return ret; 756 } 757 758 BPF_CALL_0(bpf_get_current_task) 759 { 760 return (long) current; 761 } 762 763 const struct bpf_func_proto bpf_get_current_task_proto = { 764 .func = bpf_get_current_task, 765 .gpl_only = true, 766 .ret_type = RET_INTEGER, 767 }; 768 769 BPF_CALL_0(bpf_get_current_task_btf) 770 { 771 return (unsigned long) current; 772 } 773 774 const struct bpf_func_proto bpf_get_current_task_btf_proto = { 775 .func = bpf_get_current_task_btf, 776 .gpl_only = true, 777 .ret_type = RET_PTR_TO_BTF_ID_TRUSTED, 778 .ret_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK], 779 }; 780 781 BPF_CALL_1(bpf_task_pt_regs, struct task_struct *, task) 782 { 783 return (unsigned long) task_pt_regs(task); 784 } 785 786 BTF_ID_LIST(bpf_task_pt_regs_ids) 787 BTF_ID(struct, pt_regs) 788 789 const struct bpf_func_proto bpf_task_pt_regs_proto = { 790 .func = bpf_task_pt_regs, 791 .gpl_only = true, 792 .arg1_type = ARG_PTR_TO_BTF_ID, 793 .arg1_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK], 794 .ret_type = RET_PTR_TO_BTF_ID, 795 .ret_btf_id = &bpf_task_pt_regs_ids[0], 796 }; 797 798 BPF_CALL_2(bpf_current_task_under_cgroup, struct bpf_map *, map, u32, idx) 799 { 800 struct bpf_array *array = container_of(map, struct bpf_array, map); 801 struct cgroup *cgrp; 802 803 if (unlikely(idx >= array->map.max_entries)) 804 return -E2BIG; 805 806 cgrp = READ_ONCE(array->ptrs[idx]); 807 if (unlikely(!cgrp)) 808 return -EAGAIN; 809 810 return task_under_cgroup_hierarchy(current, cgrp); 811 } 812 813 static const struct bpf_func_proto bpf_current_task_under_cgroup_proto = { 814 .func = bpf_current_task_under_cgroup, 815 .gpl_only = false, 816 .ret_type = RET_INTEGER, 817 .arg1_type = ARG_CONST_MAP_PTR, 818 .arg2_type = ARG_ANYTHING, 819 }; 820 821 struct send_signal_irq_work { 822 struct irq_work irq_work; 823 struct task_struct *task; 824 u32 sig; 825 enum pid_type type; 826 }; 827 828 static DEFINE_PER_CPU(struct send_signal_irq_work, send_signal_work); 829 830 static void do_bpf_send_signal(struct irq_work *entry) 831 { 832 struct send_signal_irq_work *work; 833 834 work = container_of(entry, struct send_signal_irq_work, irq_work); 835 group_send_sig_info(work->sig, SEND_SIG_PRIV, work->task, work->type); 836 put_task_struct(work->task); 837 } 838 839 static int bpf_send_signal_common(u32 sig, enum pid_type type) 840 { 841 struct send_signal_irq_work *work = NULL; 842 843 /* Similar to bpf_probe_write_user, task needs to be 844 * in a sound condition and kernel memory access be 845 * permitted in order to send signal to the current 846 * task. 847 */ 848 if (unlikely(current->flags & (PF_KTHREAD | PF_EXITING))) 849 return -EPERM; 850 if (unlikely(!nmi_uaccess_okay())) 851 return -EPERM; 852 /* Task should not be pid=1 to avoid kernel panic. */ 853 if (unlikely(is_global_init(current))) 854 return -EPERM; 855 856 if (irqs_disabled()) { 857 /* Do an early check on signal validity. Otherwise, 858 * the error is lost in deferred irq_work. 859 */ 860 if (unlikely(!valid_signal(sig))) 861 return -EINVAL; 862 863 work = this_cpu_ptr(&send_signal_work); 864 if (irq_work_is_busy(&work->irq_work)) 865 return -EBUSY; 866 867 /* Add the current task, which is the target of sending signal, 868 * to the irq_work. The current task may change when queued 869 * irq works get executed. 870 */ 871 work->task = get_task_struct(current); 872 work->sig = sig; 873 work->type = type; 874 irq_work_queue(&work->irq_work); 875 return 0; 876 } 877 878 return group_send_sig_info(sig, SEND_SIG_PRIV, current, type); 879 } 880 881 BPF_CALL_1(bpf_send_signal, u32, sig) 882 { 883 return bpf_send_signal_common(sig, PIDTYPE_TGID); 884 } 885 886 static const struct bpf_func_proto bpf_send_signal_proto = { 887 .func = bpf_send_signal, 888 .gpl_only = false, 889 .ret_type = RET_INTEGER, 890 .arg1_type = ARG_ANYTHING, 891 }; 892 893 BPF_CALL_1(bpf_send_signal_thread, u32, sig) 894 { 895 return bpf_send_signal_common(sig, PIDTYPE_PID); 896 } 897 898 static const struct bpf_func_proto bpf_send_signal_thread_proto = { 899 .func = bpf_send_signal_thread, 900 .gpl_only = false, 901 .ret_type = RET_INTEGER, 902 .arg1_type = ARG_ANYTHING, 903 }; 904 905 BPF_CALL_3(bpf_d_path, struct path *, path, char *, buf, u32, sz) 906 { 907 long len; 908 char *p; 909 910 if (!sz) 911 return 0; 912 913 p = d_path(path, buf, sz); 914 if (IS_ERR(p)) { 915 len = PTR_ERR(p); 916 } else { 917 len = buf + sz - p; 918 memmove(buf, p, len); 919 } 920 921 return len; 922 } 923 924 BTF_SET_START(btf_allowlist_d_path) 925 #ifdef CONFIG_SECURITY 926 BTF_ID(func, security_file_permission) 927 BTF_ID(func, security_inode_getattr) 928 BTF_ID(func, security_file_open) 929 #endif 930 #ifdef CONFIG_SECURITY_PATH 931 BTF_ID(func, security_path_truncate) 932 #endif 933 BTF_ID(func, vfs_truncate) 934 BTF_ID(func, vfs_fallocate) 935 BTF_ID(func, dentry_open) 936 BTF_ID(func, vfs_getattr) 937 BTF_ID(func, filp_close) 938 BTF_SET_END(btf_allowlist_d_path) 939 940 static bool bpf_d_path_allowed(const struct bpf_prog *prog) 941 { 942 if (prog->type == BPF_PROG_TYPE_TRACING && 943 prog->expected_attach_type == BPF_TRACE_ITER) 944 return true; 945 946 if (prog->type == BPF_PROG_TYPE_LSM) 947 return bpf_lsm_is_sleepable_hook(prog->aux->attach_btf_id); 948 949 return btf_id_set_contains(&btf_allowlist_d_path, 950 prog->aux->attach_btf_id); 951 } 952 953 BTF_ID_LIST_SINGLE(bpf_d_path_btf_ids, struct, path) 954 955 static const struct bpf_func_proto bpf_d_path_proto = { 956 .func = bpf_d_path, 957 .gpl_only = false, 958 .ret_type = RET_INTEGER, 959 .arg1_type = ARG_PTR_TO_BTF_ID, 960 .arg1_btf_id = &bpf_d_path_btf_ids[0], 961 .arg2_type = ARG_PTR_TO_MEM, 962 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 963 .allowed = bpf_d_path_allowed, 964 }; 965 966 #define BTF_F_ALL (BTF_F_COMPACT | BTF_F_NONAME | \ 967 BTF_F_PTR_RAW | BTF_F_ZERO) 968 969 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size, 970 u64 flags, const struct btf **btf, 971 s32 *btf_id) 972 { 973 const struct btf_type *t; 974 975 if (unlikely(flags & ~(BTF_F_ALL))) 976 return -EINVAL; 977 978 if (btf_ptr_size != sizeof(struct btf_ptr)) 979 return -EINVAL; 980 981 *btf = bpf_get_btf_vmlinux(); 982 983 if (IS_ERR_OR_NULL(*btf)) 984 return IS_ERR(*btf) ? PTR_ERR(*btf) : -EINVAL; 985 986 if (ptr->type_id > 0) 987 *btf_id = ptr->type_id; 988 else 989 return -EINVAL; 990 991 if (*btf_id > 0) 992 t = btf_type_by_id(*btf, *btf_id); 993 if (*btf_id <= 0 || !t) 994 return -ENOENT; 995 996 return 0; 997 } 998 999 BPF_CALL_5(bpf_snprintf_btf, char *, str, u32, str_size, struct btf_ptr *, ptr, 1000 u32, btf_ptr_size, u64, flags) 1001 { 1002 const struct btf *btf; 1003 s32 btf_id; 1004 int ret; 1005 1006 ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id); 1007 if (ret) 1008 return ret; 1009 1010 return btf_type_snprintf_show(btf, btf_id, ptr->ptr, str, str_size, 1011 flags); 1012 } 1013 1014 const struct bpf_func_proto bpf_snprintf_btf_proto = { 1015 .func = bpf_snprintf_btf, 1016 .gpl_only = false, 1017 .ret_type = RET_INTEGER, 1018 .arg1_type = ARG_PTR_TO_MEM, 1019 .arg2_type = ARG_CONST_SIZE, 1020 .arg3_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1021 .arg4_type = ARG_CONST_SIZE, 1022 .arg5_type = ARG_ANYTHING, 1023 }; 1024 1025 BPF_CALL_1(bpf_get_func_ip_tracing, void *, ctx) 1026 { 1027 /* This helper call is inlined by verifier. */ 1028 return ((u64 *)ctx)[-2]; 1029 } 1030 1031 static const struct bpf_func_proto bpf_get_func_ip_proto_tracing = { 1032 .func = bpf_get_func_ip_tracing, 1033 .gpl_only = true, 1034 .ret_type = RET_INTEGER, 1035 .arg1_type = ARG_PTR_TO_CTX, 1036 }; 1037 1038 #ifdef CONFIG_X86_KERNEL_IBT 1039 static unsigned long get_entry_ip(unsigned long fentry_ip) 1040 { 1041 u32 instr; 1042 1043 /* Being extra safe in here in case entry ip is on the page-edge. */ 1044 if (get_kernel_nofault(instr, (u32 *) fentry_ip - 1)) 1045 return fentry_ip; 1046 if (is_endbr(instr)) 1047 fentry_ip -= ENDBR_INSN_SIZE; 1048 return fentry_ip; 1049 } 1050 #else 1051 #define get_entry_ip(fentry_ip) fentry_ip 1052 #endif 1053 1054 BPF_CALL_1(bpf_get_func_ip_kprobe, struct pt_regs *, regs) 1055 { 1056 struct kprobe *kp = kprobe_running(); 1057 1058 if (!kp || !(kp->flags & KPROBE_FLAG_ON_FUNC_ENTRY)) 1059 return 0; 1060 1061 return get_entry_ip((uintptr_t)kp->addr); 1062 } 1063 1064 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe = { 1065 .func = bpf_get_func_ip_kprobe, 1066 .gpl_only = true, 1067 .ret_type = RET_INTEGER, 1068 .arg1_type = ARG_PTR_TO_CTX, 1069 }; 1070 1071 BPF_CALL_1(bpf_get_func_ip_kprobe_multi, struct pt_regs *, regs) 1072 { 1073 return bpf_kprobe_multi_entry_ip(current->bpf_ctx); 1074 } 1075 1076 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe_multi = { 1077 .func = bpf_get_func_ip_kprobe_multi, 1078 .gpl_only = false, 1079 .ret_type = RET_INTEGER, 1080 .arg1_type = ARG_PTR_TO_CTX, 1081 }; 1082 1083 BPF_CALL_1(bpf_get_attach_cookie_kprobe_multi, struct pt_regs *, regs) 1084 { 1085 return bpf_kprobe_multi_cookie(current->bpf_ctx); 1086 } 1087 1088 static const struct bpf_func_proto bpf_get_attach_cookie_proto_kmulti = { 1089 .func = bpf_get_attach_cookie_kprobe_multi, 1090 .gpl_only = false, 1091 .ret_type = RET_INTEGER, 1092 .arg1_type = ARG_PTR_TO_CTX, 1093 }; 1094 1095 BPF_CALL_1(bpf_get_attach_cookie_trace, void *, ctx) 1096 { 1097 struct bpf_trace_run_ctx *run_ctx; 1098 1099 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); 1100 return run_ctx->bpf_cookie; 1101 } 1102 1103 static const struct bpf_func_proto bpf_get_attach_cookie_proto_trace = { 1104 .func = bpf_get_attach_cookie_trace, 1105 .gpl_only = false, 1106 .ret_type = RET_INTEGER, 1107 .arg1_type = ARG_PTR_TO_CTX, 1108 }; 1109 1110 BPF_CALL_1(bpf_get_attach_cookie_pe, struct bpf_perf_event_data_kern *, ctx) 1111 { 1112 return ctx->event->bpf_cookie; 1113 } 1114 1115 static const struct bpf_func_proto bpf_get_attach_cookie_proto_pe = { 1116 .func = bpf_get_attach_cookie_pe, 1117 .gpl_only = false, 1118 .ret_type = RET_INTEGER, 1119 .arg1_type = ARG_PTR_TO_CTX, 1120 }; 1121 1122 BPF_CALL_1(bpf_get_attach_cookie_tracing, void *, ctx) 1123 { 1124 struct bpf_trace_run_ctx *run_ctx; 1125 1126 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); 1127 return run_ctx->bpf_cookie; 1128 } 1129 1130 static const struct bpf_func_proto bpf_get_attach_cookie_proto_tracing = { 1131 .func = bpf_get_attach_cookie_tracing, 1132 .gpl_only = false, 1133 .ret_type = RET_INTEGER, 1134 .arg1_type = ARG_PTR_TO_CTX, 1135 }; 1136 1137 BPF_CALL_3(bpf_get_branch_snapshot, void *, buf, u32, size, u64, flags) 1138 { 1139 #ifndef CONFIG_X86 1140 return -ENOENT; 1141 #else 1142 static const u32 br_entry_size = sizeof(struct perf_branch_entry); 1143 u32 entry_cnt = size / br_entry_size; 1144 1145 entry_cnt = static_call(perf_snapshot_branch_stack)(buf, entry_cnt); 1146 1147 if (unlikely(flags)) 1148 return -EINVAL; 1149 1150 if (!entry_cnt) 1151 return -ENOENT; 1152 1153 return entry_cnt * br_entry_size; 1154 #endif 1155 } 1156 1157 static const struct bpf_func_proto bpf_get_branch_snapshot_proto = { 1158 .func = bpf_get_branch_snapshot, 1159 .gpl_only = true, 1160 .ret_type = RET_INTEGER, 1161 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 1162 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 1163 }; 1164 1165 BPF_CALL_3(get_func_arg, void *, ctx, u32, n, u64 *, value) 1166 { 1167 /* This helper call is inlined by verifier. */ 1168 u64 nr_args = ((u64 *)ctx)[-1]; 1169 1170 if ((u64) n >= nr_args) 1171 return -EINVAL; 1172 *value = ((u64 *)ctx)[n]; 1173 return 0; 1174 } 1175 1176 static const struct bpf_func_proto bpf_get_func_arg_proto = { 1177 .func = get_func_arg, 1178 .ret_type = RET_INTEGER, 1179 .arg1_type = ARG_PTR_TO_CTX, 1180 .arg2_type = ARG_ANYTHING, 1181 .arg3_type = ARG_PTR_TO_LONG, 1182 }; 1183 1184 BPF_CALL_2(get_func_ret, void *, ctx, u64 *, value) 1185 { 1186 /* This helper call is inlined by verifier. */ 1187 u64 nr_args = ((u64 *)ctx)[-1]; 1188 1189 *value = ((u64 *)ctx)[nr_args]; 1190 return 0; 1191 } 1192 1193 static const struct bpf_func_proto bpf_get_func_ret_proto = { 1194 .func = get_func_ret, 1195 .ret_type = RET_INTEGER, 1196 .arg1_type = ARG_PTR_TO_CTX, 1197 .arg2_type = ARG_PTR_TO_LONG, 1198 }; 1199 1200 BPF_CALL_1(get_func_arg_cnt, void *, ctx) 1201 { 1202 /* This helper call is inlined by verifier. */ 1203 return ((u64 *)ctx)[-1]; 1204 } 1205 1206 static const struct bpf_func_proto bpf_get_func_arg_cnt_proto = { 1207 .func = get_func_arg_cnt, 1208 .ret_type = RET_INTEGER, 1209 .arg1_type = ARG_PTR_TO_CTX, 1210 }; 1211 1212 #ifdef CONFIG_KEYS 1213 __diag_push(); 1214 __diag_ignore_all("-Wmissing-prototypes", 1215 "kfuncs which will be used in BPF programs"); 1216 1217 /** 1218 * bpf_lookup_user_key - lookup a key by its serial 1219 * @serial: key handle serial number 1220 * @flags: lookup-specific flags 1221 * 1222 * Search a key with a given *serial* and the provided *flags*. 1223 * If found, increment the reference count of the key by one, and 1224 * return it in the bpf_key structure. 1225 * 1226 * The bpf_key structure must be passed to bpf_key_put() when done 1227 * with it, so that the key reference count is decremented and the 1228 * bpf_key structure is freed. 1229 * 1230 * Permission checks are deferred to the time the key is used by 1231 * one of the available key-specific kfuncs. 1232 * 1233 * Set *flags* with KEY_LOOKUP_CREATE, to attempt creating a requested 1234 * special keyring (e.g. session keyring), if it doesn't yet exist. 1235 * Set *flags* with KEY_LOOKUP_PARTIAL, to lookup a key without waiting 1236 * for the key construction, and to retrieve uninstantiated keys (keys 1237 * without data attached to them). 1238 * 1239 * Return: a bpf_key pointer with a valid key pointer if the key is found, a 1240 * NULL pointer otherwise. 1241 */ 1242 struct bpf_key *bpf_lookup_user_key(u32 serial, u64 flags) 1243 { 1244 key_ref_t key_ref; 1245 struct bpf_key *bkey; 1246 1247 if (flags & ~KEY_LOOKUP_ALL) 1248 return NULL; 1249 1250 /* 1251 * Permission check is deferred until the key is used, as the 1252 * intent of the caller is unknown here. 1253 */ 1254 key_ref = lookup_user_key(serial, flags, KEY_DEFER_PERM_CHECK); 1255 if (IS_ERR(key_ref)) 1256 return NULL; 1257 1258 bkey = kmalloc(sizeof(*bkey), GFP_KERNEL); 1259 if (!bkey) { 1260 key_put(key_ref_to_ptr(key_ref)); 1261 return NULL; 1262 } 1263 1264 bkey->key = key_ref_to_ptr(key_ref); 1265 bkey->has_ref = true; 1266 1267 return bkey; 1268 } 1269 1270 /** 1271 * bpf_lookup_system_key - lookup a key by a system-defined ID 1272 * @id: key ID 1273 * 1274 * Obtain a bpf_key structure with a key pointer set to the passed key ID. 1275 * The key pointer is marked as invalid, to prevent bpf_key_put() from 1276 * attempting to decrement the key reference count on that pointer. The key 1277 * pointer set in such way is currently understood only by 1278 * verify_pkcs7_signature(). 1279 * 1280 * Set *id* to one of the values defined in include/linux/verification.h: 1281 * 0 for the primary keyring (immutable keyring of system keys); 1282 * VERIFY_USE_SECONDARY_KEYRING for both the primary and secondary keyring 1283 * (where keys can be added only if they are vouched for by existing keys 1284 * in those keyrings); VERIFY_USE_PLATFORM_KEYRING for the platform 1285 * keyring (primarily used by the integrity subsystem to verify a kexec'ed 1286 * kerned image and, possibly, the initramfs signature). 1287 * 1288 * Return: a bpf_key pointer with an invalid key pointer set from the 1289 * pre-determined ID on success, a NULL pointer otherwise 1290 */ 1291 struct bpf_key *bpf_lookup_system_key(u64 id) 1292 { 1293 struct bpf_key *bkey; 1294 1295 if (system_keyring_id_check(id) < 0) 1296 return NULL; 1297 1298 bkey = kmalloc(sizeof(*bkey), GFP_ATOMIC); 1299 if (!bkey) 1300 return NULL; 1301 1302 bkey->key = (struct key *)(unsigned long)id; 1303 bkey->has_ref = false; 1304 1305 return bkey; 1306 } 1307 1308 /** 1309 * bpf_key_put - decrement key reference count if key is valid and free bpf_key 1310 * @bkey: bpf_key structure 1311 * 1312 * Decrement the reference count of the key inside *bkey*, if the pointer 1313 * is valid, and free *bkey*. 1314 */ 1315 void bpf_key_put(struct bpf_key *bkey) 1316 { 1317 if (bkey->has_ref) 1318 key_put(bkey->key); 1319 1320 kfree(bkey); 1321 } 1322 1323 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION 1324 /** 1325 * bpf_verify_pkcs7_signature - verify a PKCS#7 signature 1326 * @data_ptr: data to verify 1327 * @sig_ptr: signature of the data 1328 * @trusted_keyring: keyring with keys trusted for signature verification 1329 * 1330 * Verify the PKCS#7 signature *sig_ptr* against the supplied *data_ptr* 1331 * with keys in a keyring referenced by *trusted_keyring*. 1332 * 1333 * Return: 0 on success, a negative value on error. 1334 */ 1335 int bpf_verify_pkcs7_signature(struct bpf_dynptr_kern *data_ptr, 1336 struct bpf_dynptr_kern *sig_ptr, 1337 struct bpf_key *trusted_keyring) 1338 { 1339 int ret; 1340 1341 if (trusted_keyring->has_ref) { 1342 /* 1343 * Do the permission check deferred in bpf_lookup_user_key(). 1344 * See bpf_lookup_user_key() for more details. 1345 * 1346 * A call to key_task_permission() here would be redundant, as 1347 * it is already done by keyring_search() called by 1348 * find_asymmetric_key(). 1349 */ 1350 ret = key_validate(trusted_keyring->key); 1351 if (ret < 0) 1352 return ret; 1353 } 1354 1355 return verify_pkcs7_signature(data_ptr->data, 1356 bpf_dynptr_get_size(data_ptr), 1357 sig_ptr->data, 1358 bpf_dynptr_get_size(sig_ptr), 1359 trusted_keyring->key, 1360 VERIFYING_UNSPECIFIED_SIGNATURE, NULL, 1361 NULL); 1362 } 1363 #endif /* CONFIG_SYSTEM_DATA_VERIFICATION */ 1364 1365 __diag_pop(); 1366 1367 BTF_SET8_START(key_sig_kfunc_set) 1368 BTF_ID_FLAGS(func, bpf_lookup_user_key, KF_ACQUIRE | KF_RET_NULL | KF_SLEEPABLE) 1369 BTF_ID_FLAGS(func, bpf_lookup_system_key, KF_ACQUIRE | KF_RET_NULL) 1370 BTF_ID_FLAGS(func, bpf_key_put, KF_RELEASE) 1371 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION 1372 BTF_ID_FLAGS(func, bpf_verify_pkcs7_signature, KF_SLEEPABLE) 1373 #endif 1374 BTF_SET8_END(key_sig_kfunc_set) 1375 1376 static const struct btf_kfunc_id_set bpf_key_sig_kfunc_set = { 1377 .owner = THIS_MODULE, 1378 .set = &key_sig_kfunc_set, 1379 }; 1380 1381 static int __init bpf_key_sig_kfuncs_init(void) 1382 { 1383 return register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, 1384 &bpf_key_sig_kfunc_set); 1385 } 1386 1387 late_initcall(bpf_key_sig_kfuncs_init); 1388 #endif /* CONFIG_KEYS */ 1389 1390 static const struct bpf_func_proto * 1391 bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1392 { 1393 switch (func_id) { 1394 case BPF_FUNC_map_lookup_elem: 1395 return &bpf_map_lookup_elem_proto; 1396 case BPF_FUNC_map_update_elem: 1397 return &bpf_map_update_elem_proto; 1398 case BPF_FUNC_map_delete_elem: 1399 return &bpf_map_delete_elem_proto; 1400 case BPF_FUNC_map_push_elem: 1401 return &bpf_map_push_elem_proto; 1402 case BPF_FUNC_map_pop_elem: 1403 return &bpf_map_pop_elem_proto; 1404 case BPF_FUNC_map_peek_elem: 1405 return &bpf_map_peek_elem_proto; 1406 case BPF_FUNC_map_lookup_percpu_elem: 1407 return &bpf_map_lookup_percpu_elem_proto; 1408 case BPF_FUNC_ktime_get_ns: 1409 return &bpf_ktime_get_ns_proto; 1410 case BPF_FUNC_ktime_get_boot_ns: 1411 return &bpf_ktime_get_boot_ns_proto; 1412 case BPF_FUNC_tail_call: 1413 return &bpf_tail_call_proto; 1414 case BPF_FUNC_get_current_pid_tgid: 1415 return &bpf_get_current_pid_tgid_proto; 1416 case BPF_FUNC_get_current_task: 1417 return &bpf_get_current_task_proto; 1418 case BPF_FUNC_get_current_task_btf: 1419 return &bpf_get_current_task_btf_proto; 1420 case BPF_FUNC_task_pt_regs: 1421 return &bpf_task_pt_regs_proto; 1422 case BPF_FUNC_get_current_uid_gid: 1423 return &bpf_get_current_uid_gid_proto; 1424 case BPF_FUNC_get_current_comm: 1425 return &bpf_get_current_comm_proto; 1426 case BPF_FUNC_trace_printk: 1427 return bpf_get_trace_printk_proto(); 1428 case BPF_FUNC_get_smp_processor_id: 1429 return &bpf_get_smp_processor_id_proto; 1430 case BPF_FUNC_get_numa_node_id: 1431 return &bpf_get_numa_node_id_proto; 1432 case BPF_FUNC_perf_event_read: 1433 return &bpf_perf_event_read_proto; 1434 case BPF_FUNC_current_task_under_cgroup: 1435 return &bpf_current_task_under_cgroup_proto; 1436 case BPF_FUNC_get_prandom_u32: 1437 return &bpf_get_prandom_u32_proto; 1438 case BPF_FUNC_probe_write_user: 1439 return security_locked_down(LOCKDOWN_BPF_WRITE_USER) < 0 ? 1440 NULL : bpf_get_probe_write_proto(); 1441 case BPF_FUNC_probe_read_user: 1442 return &bpf_probe_read_user_proto; 1443 case BPF_FUNC_probe_read_kernel: 1444 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1445 NULL : &bpf_probe_read_kernel_proto; 1446 case BPF_FUNC_probe_read_user_str: 1447 return &bpf_probe_read_user_str_proto; 1448 case BPF_FUNC_probe_read_kernel_str: 1449 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1450 NULL : &bpf_probe_read_kernel_str_proto; 1451 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 1452 case BPF_FUNC_probe_read: 1453 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1454 NULL : &bpf_probe_read_compat_proto; 1455 case BPF_FUNC_probe_read_str: 1456 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1457 NULL : &bpf_probe_read_compat_str_proto; 1458 #endif 1459 #ifdef CONFIG_CGROUPS 1460 case BPF_FUNC_get_current_cgroup_id: 1461 return &bpf_get_current_cgroup_id_proto; 1462 case BPF_FUNC_get_current_ancestor_cgroup_id: 1463 return &bpf_get_current_ancestor_cgroup_id_proto; 1464 case BPF_FUNC_cgrp_storage_get: 1465 return &bpf_cgrp_storage_get_proto; 1466 case BPF_FUNC_cgrp_storage_delete: 1467 return &bpf_cgrp_storage_delete_proto; 1468 #endif 1469 case BPF_FUNC_send_signal: 1470 return &bpf_send_signal_proto; 1471 case BPF_FUNC_send_signal_thread: 1472 return &bpf_send_signal_thread_proto; 1473 case BPF_FUNC_perf_event_read_value: 1474 return &bpf_perf_event_read_value_proto; 1475 case BPF_FUNC_get_ns_current_pid_tgid: 1476 return &bpf_get_ns_current_pid_tgid_proto; 1477 case BPF_FUNC_ringbuf_output: 1478 return &bpf_ringbuf_output_proto; 1479 case BPF_FUNC_ringbuf_reserve: 1480 return &bpf_ringbuf_reserve_proto; 1481 case BPF_FUNC_ringbuf_submit: 1482 return &bpf_ringbuf_submit_proto; 1483 case BPF_FUNC_ringbuf_discard: 1484 return &bpf_ringbuf_discard_proto; 1485 case BPF_FUNC_ringbuf_query: 1486 return &bpf_ringbuf_query_proto; 1487 case BPF_FUNC_jiffies64: 1488 return &bpf_jiffies64_proto; 1489 case BPF_FUNC_get_task_stack: 1490 return &bpf_get_task_stack_proto; 1491 case BPF_FUNC_copy_from_user: 1492 return &bpf_copy_from_user_proto; 1493 case BPF_FUNC_copy_from_user_task: 1494 return &bpf_copy_from_user_task_proto; 1495 case BPF_FUNC_snprintf_btf: 1496 return &bpf_snprintf_btf_proto; 1497 case BPF_FUNC_per_cpu_ptr: 1498 return &bpf_per_cpu_ptr_proto; 1499 case BPF_FUNC_this_cpu_ptr: 1500 return &bpf_this_cpu_ptr_proto; 1501 case BPF_FUNC_task_storage_get: 1502 if (bpf_prog_check_recur(prog)) 1503 return &bpf_task_storage_get_recur_proto; 1504 return &bpf_task_storage_get_proto; 1505 case BPF_FUNC_task_storage_delete: 1506 if (bpf_prog_check_recur(prog)) 1507 return &bpf_task_storage_delete_recur_proto; 1508 return &bpf_task_storage_delete_proto; 1509 case BPF_FUNC_for_each_map_elem: 1510 return &bpf_for_each_map_elem_proto; 1511 case BPF_FUNC_snprintf: 1512 return &bpf_snprintf_proto; 1513 case BPF_FUNC_get_func_ip: 1514 return &bpf_get_func_ip_proto_tracing; 1515 case BPF_FUNC_get_branch_snapshot: 1516 return &bpf_get_branch_snapshot_proto; 1517 case BPF_FUNC_find_vma: 1518 return &bpf_find_vma_proto; 1519 case BPF_FUNC_trace_vprintk: 1520 return bpf_get_trace_vprintk_proto(); 1521 default: 1522 return bpf_base_func_proto(func_id); 1523 } 1524 } 1525 1526 static const struct bpf_func_proto * 1527 kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1528 { 1529 switch (func_id) { 1530 case BPF_FUNC_perf_event_output: 1531 return &bpf_perf_event_output_proto; 1532 case BPF_FUNC_get_stackid: 1533 return &bpf_get_stackid_proto; 1534 case BPF_FUNC_get_stack: 1535 return &bpf_get_stack_proto; 1536 #ifdef CONFIG_BPF_KPROBE_OVERRIDE 1537 case BPF_FUNC_override_return: 1538 return &bpf_override_return_proto; 1539 #endif 1540 case BPF_FUNC_get_func_ip: 1541 return prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI ? 1542 &bpf_get_func_ip_proto_kprobe_multi : 1543 &bpf_get_func_ip_proto_kprobe; 1544 case BPF_FUNC_get_attach_cookie: 1545 return prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI ? 1546 &bpf_get_attach_cookie_proto_kmulti : 1547 &bpf_get_attach_cookie_proto_trace; 1548 default: 1549 return bpf_tracing_func_proto(func_id, prog); 1550 } 1551 } 1552 1553 /* bpf+kprobe programs can access fields of 'struct pt_regs' */ 1554 static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type, 1555 const struct bpf_prog *prog, 1556 struct bpf_insn_access_aux *info) 1557 { 1558 if (off < 0 || off >= sizeof(struct pt_regs)) 1559 return false; 1560 if (type != BPF_READ) 1561 return false; 1562 if (off % size != 0) 1563 return false; 1564 /* 1565 * Assertion for 32 bit to make sure last 8 byte access 1566 * (BPF_DW) to the last 4 byte member is disallowed. 1567 */ 1568 if (off + size > sizeof(struct pt_regs)) 1569 return false; 1570 1571 return true; 1572 } 1573 1574 const struct bpf_verifier_ops kprobe_verifier_ops = { 1575 .get_func_proto = kprobe_prog_func_proto, 1576 .is_valid_access = kprobe_prog_is_valid_access, 1577 }; 1578 1579 const struct bpf_prog_ops kprobe_prog_ops = { 1580 }; 1581 1582 BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map, 1583 u64, flags, void *, data, u64, size) 1584 { 1585 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1586 1587 /* 1588 * r1 points to perf tracepoint buffer where first 8 bytes are hidden 1589 * from bpf program and contain a pointer to 'struct pt_regs'. Fetch it 1590 * from there and call the same bpf_perf_event_output() helper inline. 1591 */ 1592 return ____bpf_perf_event_output(regs, map, flags, data, size); 1593 } 1594 1595 static const struct bpf_func_proto bpf_perf_event_output_proto_tp = { 1596 .func = bpf_perf_event_output_tp, 1597 .gpl_only = true, 1598 .ret_type = RET_INTEGER, 1599 .arg1_type = ARG_PTR_TO_CTX, 1600 .arg2_type = ARG_CONST_MAP_PTR, 1601 .arg3_type = ARG_ANYTHING, 1602 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1603 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 1604 }; 1605 1606 BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map, 1607 u64, flags) 1608 { 1609 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1610 1611 /* 1612 * Same comment as in bpf_perf_event_output_tp(), only that this time 1613 * the other helper's function body cannot be inlined due to being 1614 * external, thus we need to call raw helper function. 1615 */ 1616 return bpf_get_stackid((unsigned long) regs, (unsigned long) map, 1617 flags, 0, 0); 1618 } 1619 1620 static const struct bpf_func_proto bpf_get_stackid_proto_tp = { 1621 .func = bpf_get_stackid_tp, 1622 .gpl_only = true, 1623 .ret_type = RET_INTEGER, 1624 .arg1_type = ARG_PTR_TO_CTX, 1625 .arg2_type = ARG_CONST_MAP_PTR, 1626 .arg3_type = ARG_ANYTHING, 1627 }; 1628 1629 BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size, 1630 u64, flags) 1631 { 1632 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1633 1634 return bpf_get_stack((unsigned long) regs, (unsigned long) buf, 1635 (unsigned long) size, flags, 0); 1636 } 1637 1638 static const struct bpf_func_proto bpf_get_stack_proto_tp = { 1639 .func = bpf_get_stack_tp, 1640 .gpl_only = true, 1641 .ret_type = RET_INTEGER, 1642 .arg1_type = ARG_PTR_TO_CTX, 1643 .arg2_type = ARG_PTR_TO_UNINIT_MEM, 1644 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1645 .arg4_type = ARG_ANYTHING, 1646 }; 1647 1648 static const struct bpf_func_proto * 1649 tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1650 { 1651 switch (func_id) { 1652 case BPF_FUNC_perf_event_output: 1653 return &bpf_perf_event_output_proto_tp; 1654 case BPF_FUNC_get_stackid: 1655 return &bpf_get_stackid_proto_tp; 1656 case BPF_FUNC_get_stack: 1657 return &bpf_get_stack_proto_tp; 1658 case BPF_FUNC_get_attach_cookie: 1659 return &bpf_get_attach_cookie_proto_trace; 1660 default: 1661 return bpf_tracing_func_proto(func_id, prog); 1662 } 1663 } 1664 1665 static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type, 1666 const struct bpf_prog *prog, 1667 struct bpf_insn_access_aux *info) 1668 { 1669 if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE) 1670 return false; 1671 if (type != BPF_READ) 1672 return false; 1673 if (off % size != 0) 1674 return false; 1675 1676 BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(__u64)); 1677 return true; 1678 } 1679 1680 const struct bpf_verifier_ops tracepoint_verifier_ops = { 1681 .get_func_proto = tp_prog_func_proto, 1682 .is_valid_access = tp_prog_is_valid_access, 1683 }; 1684 1685 const struct bpf_prog_ops tracepoint_prog_ops = { 1686 }; 1687 1688 BPF_CALL_3(bpf_perf_prog_read_value, struct bpf_perf_event_data_kern *, ctx, 1689 struct bpf_perf_event_value *, buf, u32, size) 1690 { 1691 int err = -EINVAL; 1692 1693 if (unlikely(size != sizeof(struct bpf_perf_event_value))) 1694 goto clear; 1695 err = perf_event_read_local(ctx->event, &buf->counter, &buf->enabled, 1696 &buf->running); 1697 if (unlikely(err)) 1698 goto clear; 1699 return 0; 1700 clear: 1701 memset(buf, 0, size); 1702 return err; 1703 } 1704 1705 static const struct bpf_func_proto bpf_perf_prog_read_value_proto = { 1706 .func = bpf_perf_prog_read_value, 1707 .gpl_only = true, 1708 .ret_type = RET_INTEGER, 1709 .arg1_type = ARG_PTR_TO_CTX, 1710 .arg2_type = ARG_PTR_TO_UNINIT_MEM, 1711 .arg3_type = ARG_CONST_SIZE, 1712 }; 1713 1714 BPF_CALL_4(bpf_read_branch_records, struct bpf_perf_event_data_kern *, ctx, 1715 void *, buf, u32, size, u64, flags) 1716 { 1717 static const u32 br_entry_size = sizeof(struct perf_branch_entry); 1718 struct perf_branch_stack *br_stack = ctx->data->br_stack; 1719 u32 to_copy; 1720 1721 if (unlikely(flags & ~BPF_F_GET_BRANCH_RECORDS_SIZE)) 1722 return -EINVAL; 1723 1724 if (unlikely(!(ctx->data->sample_flags & PERF_SAMPLE_BRANCH_STACK))) 1725 return -ENOENT; 1726 1727 if (unlikely(!br_stack)) 1728 return -ENOENT; 1729 1730 if (flags & BPF_F_GET_BRANCH_RECORDS_SIZE) 1731 return br_stack->nr * br_entry_size; 1732 1733 if (!buf || (size % br_entry_size != 0)) 1734 return -EINVAL; 1735 1736 to_copy = min_t(u32, br_stack->nr * br_entry_size, size); 1737 memcpy(buf, br_stack->entries, to_copy); 1738 1739 return to_copy; 1740 } 1741 1742 static const struct bpf_func_proto bpf_read_branch_records_proto = { 1743 .func = bpf_read_branch_records, 1744 .gpl_only = true, 1745 .ret_type = RET_INTEGER, 1746 .arg1_type = ARG_PTR_TO_CTX, 1747 .arg2_type = ARG_PTR_TO_MEM_OR_NULL, 1748 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1749 .arg4_type = ARG_ANYTHING, 1750 }; 1751 1752 static const struct bpf_func_proto * 1753 pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1754 { 1755 switch (func_id) { 1756 case BPF_FUNC_perf_event_output: 1757 return &bpf_perf_event_output_proto_tp; 1758 case BPF_FUNC_get_stackid: 1759 return &bpf_get_stackid_proto_pe; 1760 case BPF_FUNC_get_stack: 1761 return &bpf_get_stack_proto_pe; 1762 case BPF_FUNC_perf_prog_read_value: 1763 return &bpf_perf_prog_read_value_proto; 1764 case BPF_FUNC_read_branch_records: 1765 return &bpf_read_branch_records_proto; 1766 case BPF_FUNC_get_attach_cookie: 1767 return &bpf_get_attach_cookie_proto_pe; 1768 default: 1769 return bpf_tracing_func_proto(func_id, prog); 1770 } 1771 } 1772 1773 /* 1774 * bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp 1775 * to avoid potential recursive reuse issue when/if tracepoints are added 1776 * inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack. 1777 * 1778 * Since raw tracepoints run despite bpf_prog_active, support concurrent usage 1779 * in normal, irq, and nmi context. 1780 */ 1781 struct bpf_raw_tp_regs { 1782 struct pt_regs regs[3]; 1783 }; 1784 static DEFINE_PER_CPU(struct bpf_raw_tp_regs, bpf_raw_tp_regs); 1785 static DEFINE_PER_CPU(int, bpf_raw_tp_nest_level); 1786 static struct pt_regs *get_bpf_raw_tp_regs(void) 1787 { 1788 struct bpf_raw_tp_regs *tp_regs = this_cpu_ptr(&bpf_raw_tp_regs); 1789 int nest_level = this_cpu_inc_return(bpf_raw_tp_nest_level); 1790 1791 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(tp_regs->regs))) { 1792 this_cpu_dec(bpf_raw_tp_nest_level); 1793 return ERR_PTR(-EBUSY); 1794 } 1795 1796 return &tp_regs->regs[nest_level - 1]; 1797 } 1798 1799 static void put_bpf_raw_tp_regs(void) 1800 { 1801 this_cpu_dec(bpf_raw_tp_nest_level); 1802 } 1803 1804 BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args, 1805 struct bpf_map *, map, u64, flags, void *, data, u64, size) 1806 { 1807 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1808 int ret; 1809 1810 if (IS_ERR(regs)) 1811 return PTR_ERR(regs); 1812 1813 perf_fetch_caller_regs(regs); 1814 ret = ____bpf_perf_event_output(regs, map, flags, data, size); 1815 1816 put_bpf_raw_tp_regs(); 1817 return ret; 1818 } 1819 1820 static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = { 1821 .func = bpf_perf_event_output_raw_tp, 1822 .gpl_only = true, 1823 .ret_type = RET_INTEGER, 1824 .arg1_type = ARG_PTR_TO_CTX, 1825 .arg2_type = ARG_CONST_MAP_PTR, 1826 .arg3_type = ARG_ANYTHING, 1827 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1828 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 1829 }; 1830 1831 extern const struct bpf_func_proto bpf_skb_output_proto; 1832 extern const struct bpf_func_proto bpf_xdp_output_proto; 1833 extern const struct bpf_func_proto bpf_xdp_get_buff_len_trace_proto; 1834 1835 BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args, 1836 struct bpf_map *, map, u64, flags) 1837 { 1838 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1839 int ret; 1840 1841 if (IS_ERR(regs)) 1842 return PTR_ERR(regs); 1843 1844 perf_fetch_caller_regs(regs); 1845 /* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */ 1846 ret = bpf_get_stackid((unsigned long) regs, (unsigned long) map, 1847 flags, 0, 0); 1848 put_bpf_raw_tp_regs(); 1849 return ret; 1850 } 1851 1852 static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = { 1853 .func = bpf_get_stackid_raw_tp, 1854 .gpl_only = true, 1855 .ret_type = RET_INTEGER, 1856 .arg1_type = ARG_PTR_TO_CTX, 1857 .arg2_type = ARG_CONST_MAP_PTR, 1858 .arg3_type = ARG_ANYTHING, 1859 }; 1860 1861 BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args, 1862 void *, buf, u32, size, u64, flags) 1863 { 1864 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1865 int ret; 1866 1867 if (IS_ERR(regs)) 1868 return PTR_ERR(regs); 1869 1870 perf_fetch_caller_regs(regs); 1871 ret = bpf_get_stack((unsigned long) regs, (unsigned long) buf, 1872 (unsigned long) size, flags, 0); 1873 put_bpf_raw_tp_regs(); 1874 return ret; 1875 } 1876 1877 static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = { 1878 .func = bpf_get_stack_raw_tp, 1879 .gpl_only = true, 1880 .ret_type = RET_INTEGER, 1881 .arg1_type = ARG_PTR_TO_CTX, 1882 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1883 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1884 .arg4_type = ARG_ANYTHING, 1885 }; 1886 1887 static const struct bpf_func_proto * 1888 raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1889 { 1890 switch (func_id) { 1891 case BPF_FUNC_perf_event_output: 1892 return &bpf_perf_event_output_proto_raw_tp; 1893 case BPF_FUNC_get_stackid: 1894 return &bpf_get_stackid_proto_raw_tp; 1895 case BPF_FUNC_get_stack: 1896 return &bpf_get_stack_proto_raw_tp; 1897 default: 1898 return bpf_tracing_func_proto(func_id, prog); 1899 } 1900 } 1901 1902 const struct bpf_func_proto * 1903 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1904 { 1905 const struct bpf_func_proto *fn; 1906 1907 switch (func_id) { 1908 #ifdef CONFIG_NET 1909 case BPF_FUNC_skb_output: 1910 return &bpf_skb_output_proto; 1911 case BPF_FUNC_xdp_output: 1912 return &bpf_xdp_output_proto; 1913 case BPF_FUNC_skc_to_tcp6_sock: 1914 return &bpf_skc_to_tcp6_sock_proto; 1915 case BPF_FUNC_skc_to_tcp_sock: 1916 return &bpf_skc_to_tcp_sock_proto; 1917 case BPF_FUNC_skc_to_tcp_timewait_sock: 1918 return &bpf_skc_to_tcp_timewait_sock_proto; 1919 case BPF_FUNC_skc_to_tcp_request_sock: 1920 return &bpf_skc_to_tcp_request_sock_proto; 1921 case BPF_FUNC_skc_to_udp6_sock: 1922 return &bpf_skc_to_udp6_sock_proto; 1923 case BPF_FUNC_skc_to_unix_sock: 1924 return &bpf_skc_to_unix_sock_proto; 1925 case BPF_FUNC_skc_to_mptcp_sock: 1926 return &bpf_skc_to_mptcp_sock_proto; 1927 case BPF_FUNC_sk_storage_get: 1928 return &bpf_sk_storage_get_tracing_proto; 1929 case BPF_FUNC_sk_storage_delete: 1930 return &bpf_sk_storage_delete_tracing_proto; 1931 case BPF_FUNC_sock_from_file: 1932 return &bpf_sock_from_file_proto; 1933 case BPF_FUNC_get_socket_cookie: 1934 return &bpf_get_socket_ptr_cookie_proto; 1935 case BPF_FUNC_xdp_get_buff_len: 1936 return &bpf_xdp_get_buff_len_trace_proto; 1937 #endif 1938 case BPF_FUNC_seq_printf: 1939 return prog->expected_attach_type == BPF_TRACE_ITER ? 1940 &bpf_seq_printf_proto : 1941 NULL; 1942 case BPF_FUNC_seq_write: 1943 return prog->expected_attach_type == BPF_TRACE_ITER ? 1944 &bpf_seq_write_proto : 1945 NULL; 1946 case BPF_FUNC_seq_printf_btf: 1947 return prog->expected_attach_type == BPF_TRACE_ITER ? 1948 &bpf_seq_printf_btf_proto : 1949 NULL; 1950 case BPF_FUNC_d_path: 1951 return &bpf_d_path_proto; 1952 case BPF_FUNC_get_func_arg: 1953 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_proto : NULL; 1954 case BPF_FUNC_get_func_ret: 1955 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_ret_proto : NULL; 1956 case BPF_FUNC_get_func_arg_cnt: 1957 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_cnt_proto : NULL; 1958 case BPF_FUNC_get_attach_cookie: 1959 return bpf_prog_has_trampoline(prog) ? &bpf_get_attach_cookie_proto_tracing : NULL; 1960 default: 1961 fn = raw_tp_prog_func_proto(func_id, prog); 1962 if (!fn && prog->expected_attach_type == BPF_TRACE_ITER) 1963 fn = bpf_iter_get_func_proto(func_id, prog); 1964 return fn; 1965 } 1966 } 1967 1968 static bool raw_tp_prog_is_valid_access(int off, int size, 1969 enum bpf_access_type type, 1970 const struct bpf_prog *prog, 1971 struct bpf_insn_access_aux *info) 1972 { 1973 return bpf_tracing_ctx_access(off, size, type); 1974 } 1975 1976 static bool tracing_prog_is_valid_access(int off, int size, 1977 enum bpf_access_type type, 1978 const struct bpf_prog *prog, 1979 struct bpf_insn_access_aux *info) 1980 { 1981 return bpf_tracing_btf_ctx_access(off, size, type, prog, info); 1982 } 1983 1984 int __weak bpf_prog_test_run_tracing(struct bpf_prog *prog, 1985 const union bpf_attr *kattr, 1986 union bpf_attr __user *uattr) 1987 { 1988 return -ENOTSUPP; 1989 } 1990 1991 const struct bpf_verifier_ops raw_tracepoint_verifier_ops = { 1992 .get_func_proto = raw_tp_prog_func_proto, 1993 .is_valid_access = raw_tp_prog_is_valid_access, 1994 }; 1995 1996 const struct bpf_prog_ops raw_tracepoint_prog_ops = { 1997 #ifdef CONFIG_NET 1998 .test_run = bpf_prog_test_run_raw_tp, 1999 #endif 2000 }; 2001 2002 const struct bpf_verifier_ops tracing_verifier_ops = { 2003 .get_func_proto = tracing_prog_func_proto, 2004 .is_valid_access = tracing_prog_is_valid_access, 2005 }; 2006 2007 const struct bpf_prog_ops tracing_prog_ops = { 2008 .test_run = bpf_prog_test_run_tracing, 2009 }; 2010 2011 static bool raw_tp_writable_prog_is_valid_access(int off, int size, 2012 enum bpf_access_type type, 2013 const struct bpf_prog *prog, 2014 struct bpf_insn_access_aux *info) 2015 { 2016 if (off == 0) { 2017 if (size != sizeof(u64) || type != BPF_READ) 2018 return false; 2019 info->reg_type = PTR_TO_TP_BUFFER; 2020 } 2021 return raw_tp_prog_is_valid_access(off, size, type, prog, info); 2022 } 2023 2024 const struct bpf_verifier_ops raw_tracepoint_writable_verifier_ops = { 2025 .get_func_proto = raw_tp_prog_func_proto, 2026 .is_valid_access = raw_tp_writable_prog_is_valid_access, 2027 }; 2028 2029 const struct bpf_prog_ops raw_tracepoint_writable_prog_ops = { 2030 }; 2031 2032 static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type, 2033 const struct bpf_prog *prog, 2034 struct bpf_insn_access_aux *info) 2035 { 2036 const int size_u64 = sizeof(u64); 2037 2038 if (off < 0 || off >= sizeof(struct bpf_perf_event_data)) 2039 return false; 2040 if (type != BPF_READ) 2041 return false; 2042 if (off % size != 0) { 2043 if (sizeof(unsigned long) != 4) 2044 return false; 2045 if (size != 8) 2046 return false; 2047 if (off % size != 4) 2048 return false; 2049 } 2050 2051 switch (off) { 2052 case bpf_ctx_range(struct bpf_perf_event_data, sample_period): 2053 bpf_ctx_record_field_size(info, size_u64); 2054 if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) 2055 return false; 2056 break; 2057 case bpf_ctx_range(struct bpf_perf_event_data, addr): 2058 bpf_ctx_record_field_size(info, size_u64); 2059 if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) 2060 return false; 2061 break; 2062 default: 2063 if (size != sizeof(long)) 2064 return false; 2065 } 2066 2067 return true; 2068 } 2069 2070 static u32 pe_prog_convert_ctx_access(enum bpf_access_type type, 2071 const struct bpf_insn *si, 2072 struct bpf_insn *insn_buf, 2073 struct bpf_prog *prog, u32 *target_size) 2074 { 2075 struct bpf_insn *insn = insn_buf; 2076 2077 switch (si->off) { 2078 case offsetof(struct bpf_perf_event_data, sample_period): 2079 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 2080 data), si->dst_reg, si->src_reg, 2081 offsetof(struct bpf_perf_event_data_kern, data)); 2082 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, 2083 bpf_target_off(struct perf_sample_data, period, 8, 2084 target_size)); 2085 break; 2086 case offsetof(struct bpf_perf_event_data, addr): 2087 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 2088 data), si->dst_reg, si->src_reg, 2089 offsetof(struct bpf_perf_event_data_kern, data)); 2090 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, 2091 bpf_target_off(struct perf_sample_data, addr, 8, 2092 target_size)); 2093 break; 2094 default: 2095 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 2096 regs), si->dst_reg, si->src_reg, 2097 offsetof(struct bpf_perf_event_data_kern, regs)); 2098 *insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg, 2099 si->off); 2100 break; 2101 } 2102 2103 return insn - insn_buf; 2104 } 2105 2106 const struct bpf_verifier_ops perf_event_verifier_ops = { 2107 .get_func_proto = pe_prog_func_proto, 2108 .is_valid_access = pe_prog_is_valid_access, 2109 .convert_ctx_access = pe_prog_convert_ctx_access, 2110 }; 2111 2112 const struct bpf_prog_ops perf_event_prog_ops = { 2113 }; 2114 2115 static DEFINE_MUTEX(bpf_event_mutex); 2116 2117 #define BPF_TRACE_MAX_PROGS 64 2118 2119 int perf_event_attach_bpf_prog(struct perf_event *event, 2120 struct bpf_prog *prog, 2121 u64 bpf_cookie) 2122 { 2123 struct bpf_prog_array *old_array; 2124 struct bpf_prog_array *new_array; 2125 int ret = -EEXIST; 2126 2127 /* 2128 * Kprobe override only works if they are on the function entry, 2129 * and only if they are on the opt-in list. 2130 */ 2131 if (prog->kprobe_override && 2132 (!trace_kprobe_on_func_entry(event->tp_event) || 2133 !trace_kprobe_error_injectable(event->tp_event))) 2134 return -EINVAL; 2135 2136 mutex_lock(&bpf_event_mutex); 2137 2138 if (event->prog) 2139 goto unlock; 2140 2141 old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); 2142 if (old_array && 2143 bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) { 2144 ret = -E2BIG; 2145 goto unlock; 2146 } 2147 2148 ret = bpf_prog_array_copy(old_array, NULL, prog, bpf_cookie, &new_array); 2149 if (ret < 0) 2150 goto unlock; 2151 2152 /* set the new array to event->tp_event and set event->prog */ 2153 event->prog = prog; 2154 event->bpf_cookie = bpf_cookie; 2155 rcu_assign_pointer(event->tp_event->prog_array, new_array); 2156 bpf_prog_array_free_sleepable(old_array); 2157 2158 unlock: 2159 mutex_unlock(&bpf_event_mutex); 2160 return ret; 2161 } 2162 2163 void perf_event_detach_bpf_prog(struct perf_event *event) 2164 { 2165 struct bpf_prog_array *old_array; 2166 struct bpf_prog_array *new_array; 2167 int ret; 2168 2169 mutex_lock(&bpf_event_mutex); 2170 2171 if (!event->prog) 2172 goto unlock; 2173 2174 old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); 2175 ret = bpf_prog_array_copy(old_array, event->prog, NULL, 0, &new_array); 2176 if (ret == -ENOENT) 2177 goto unlock; 2178 if (ret < 0) { 2179 bpf_prog_array_delete_safe(old_array, event->prog); 2180 } else { 2181 rcu_assign_pointer(event->tp_event->prog_array, new_array); 2182 bpf_prog_array_free_sleepable(old_array); 2183 } 2184 2185 bpf_prog_put(event->prog); 2186 event->prog = NULL; 2187 2188 unlock: 2189 mutex_unlock(&bpf_event_mutex); 2190 } 2191 2192 int perf_event_query_prog_array(struct perf_event *event, void __user *info) 2193 { 2194 struct perf_event_query_bpf __user *uquery = info; 2195 struct perf_event_query_bpf query = {}; 2196 struct bpf_prog_array *progs; 2197 u32 *ids, prog_cnt, ids_len; 2198 int ret; 2199 2200 if (!perfmon_capable()) 2201 return -EPERM; 2202 if (event->attr.type != PERF_TYPE_TRACEPOINT) 2203 return -EINVAL; 2204 if (copy_from_user(&query, uquery, sizeof(query))) 2205 return -EFAULT; 2206 2207 ids_len = query.ids_len; 2208 if (ids_len > BPF_TRACE_MAX_PROGS) 2209 return -E2BIG; 2210 ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN); 2211 if (!ids) 2212 return -ENOMEM; 2213 /* 2214 * The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which 2215 * is required when user only wants to check for uquery->prog_cnt. 2216 * There is no need to check for it since the case is handled 2217 * gracefully in bpf_prog_array_copy_info. 2218 */ 2219 2220 mutex_lock(&bpf_event_mutex); 2221 progs = bpf_event_rcu_dereference(event->tp_event->prog_array); 2222 ret = bpf_prog_array_copy_info(progs, ids, ids_len, &prog_cnt); 2223 mutex_unlock(&bpf_event_mutex); 2224 2225 if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) || 2226 copy_to_user(uquery->ids, ids, ids_len * sizeof(u32))) 2227 ret = -EFAULT; 2228 2229 kfree(ids); 2230 return ret; 2231 } 2232 2233 extern struct bpf_raw_event_map __start__bpf_raw_tp[]; 2234 extern struct bpf_raw_event_map __stop__bpf_raw_tp[]; 2235 2236 struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name) 2237 { 2238 struct bpf_raw_event_map *btp = __start__bpf_raw_tp; 2239 2240 for (; btp < __stop__bpf_raw_tp; btp++) { 2241 if (!strcmp(btp->tp->name, name)) 2242 return btp; 2243 } 2244 2245 return bpf_get_raw_tracepoint_module(name); 2246 } 2247 2248 void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp) 2249 { 2250 struct module *mod; 2251 2252 preempt_disable(); 2253 mod = __module_address((unsigned long)btp); 2254 module_put(mod); 2255 preempt_enable(); 2256 } 2257 2258 static __always_inline 2259 void __bpf_trace_run(struct bpf_prog *prog, u64 *args) 2260 { 2261 cant_sleep(); 2262 if (unlikely(this_cpu_inc_return(*(prog->active)) != 1)) { 2263 bpf_prog_inc_misses_counter(prog); 2264 goto out; 2265 } 2266 rcu_read_lock(); 2267 (void) bpf_prog_run(prog, args); 2268 rcu_read_unlock(); 2269 out: 2270 this_cpu_dec(*(prog->active)); 2271 } 2272 2273 #define UNPACK(...) __VA_ARGS__ 2274 #define REPEAT_1(FN, DL, X, ...) FN(X) 2275 #define REPEAT_2(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__) 2276 #define REPEAT_3(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_2(FN, DL, __VA_ARGS__) 2277 #define REPEAT_4(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_3(FN, DL, __VA_ARGS__) 2278 #define REPEAT_5(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_4(FN, DL, __VA_ARGS__) 2279 #define REPEAT_6(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_5(FN, DL, __VA_ARGS__) 2280 #define REPEAT_7(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_6(FN, DL, __VA_ARGS__) 2281 #define REPEAT_8(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_7(FN, DL, __VA_ARGS__) 2282 #define REPEAT_9(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_8(FN, DL, __VA_ARGS__) 2283 #define REPEAT_10(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_9(FN, DL, __VA_ARGS__) 2284 #define REPEAT_11(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_10(FN, DL, __VA_ARGS__) 2285 #define REPEAT_12(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_11(FN, DL, __VA_ARGS__) 2286 #define REPEAT(X, FN, DL, ...) REPEAT_##X(FN, DL, __VA_ARGS__) 2287 2288 #define SARG(X) u64 arg##X 2289 #define COPY(X) args[X] = arg##X 2290 2291 #define __DL_COM (,) 2292 #define __DL_SEM (;) 2293 2294 #define __SEQ_0_11 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 2295 2296 #define BPF_TRACE_DEFN_x(x) \ 2297 void bpf_trace_run##x(struct bpf_prog *prog, \ 2298 REPEAT(x, SARG, __DL_COM, __SEQ_0_11)) \ 2299 { \ 2300 u64 args[x]; \ 2301 REPEAT(x, COPY, __DL_SEM, __SEQ_0_11); \ 2302 __bpf_trace_run(prog, args); \ 2303 } \ 2304 EXPORT_SYMBOL_GPL(bpf_trace_run##x) 2305 BPF_TRACE_DEFN_x(1); 2306 BPF_TRACE_DEFN_x(2); 2307 BPF_TRACE_DEFN_x(3); 2308 BPF_TRACE_DEFN_x(4); 2309 BPF_TRACE_DEFN_x(5); 2310 BPF_TRACE_DEFN_x(6); 2311 BPF_TRACE_DEFN_x(7); 2312 BPF_TRACE_DEFN_x(8); 2313 BPF_TRACE_DEFN_x(9); 2314 BPF_TRACE_DEFN_x(10); 2315 BPF_TRACE_DEFN_x(11); 2316 BPF_TRACE_DEFN_x(12); 2317 2318 static int __bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog) 2319 { 2320 struct tracepoint *tp = btp->tp; 2321 2322 /* 2323 * check that program doesn't access arguments beyond what's 2324 * available in this tracepoint 2325 */ 2326 if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64)) 2327 return -EINVAL; 2328 2329 if (prog->aux->max_tp_access > btp->writable_size) 2330 return -EINVAL; 2331 2332 return tracepoint_probe_register_may_exist(tp, (void *)btp->bpf_func, 2333 prog); 2334 } 2335 2336 int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog) 2337 { 2338 return __bpf_probe_register(btp, prog); 2339 } 2340 2341 int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_prog *prog) 2342 { 2343 return tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, prog); 2344 } 2345 2346 int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id, 2347 u32 *fd_type, const char **buf, 2348 u64 *probe_offset, u64 *probe_addr) 2349 { 2350 bool is_tracepoint, is_syscall_tp; 2351 struct bpf_prog *prog; 2352 int flags, err = 0; 2353 2354 prog = event->prog; 2355 if (!prog) 2356 return -ENOENT; 2357 2358 /* not supporting BPF_PROG_TYPE_PERF_EVENT yet */ 2359 if (prog->type == BPF_PROG_TYPE_PERF_EVENT) 2360 return -EOPNOTSUPP; 2361 2362 *prog_id = prog->aux->id; 2363 flags = event->tp_event->flags; 2364 is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT; 2365 is_syscall_tp = is_syscall_trace_event(event->tp_event); 2366 2367 if (is_tracepoint || is_syscall_tp) { 2368 *buf = is_tracepoint ? event->tp_event->tp->name 2369 : event->tp_event->name; 2370 *fd_type = BPF_FD_TYPE_TRACEPOINT; 2371 *probe_offset = 0x0; 2372 *probe_addr = 0x0; 2373 } else { 2374 /* kprobe/uprobe */ 2375 err = -EOPNOTSUPP; 2376 #ifdef CONFIG_KPROBE_EVENTS 2377 if (flags & TRACE_EVENT_FL_KPROBE) 2378 err = bpf_get_kprobe_info(event, fd_type, buf, 2379 probe_offset, probe_addr, 2380 event->attr.type == PERF_TYPE_TRACEPOINT); 2381 #endif 2382 #ifdef CONFIG_UPROBE_EVENTS 2383 if (flags & TRACE_EVENT_FL_UPROBE) 2384 err = bpf_get_uprobe_info(event, fd_type, buf, 2385 probe_offset, 2386 event->attr.type == PERF_TYPE_TRACEPOINT); 2387 #endif 2388 } 2389 2390 return err; 2391 } 2392 2393 static int __init send_signal_irq_work_init(void) 2394 { 2395 int cpu; 2396 struct send_signal_irq_work *work; 2397 2398 for_each_possible_cpu(cpu) { 2399 work = per_cpu_ptr(&send_signal_work, cpu); 2400 init_irq_work(&work->irq_work, do_bpf_send_signal); 2401 } 2402 return 0; 2403 } 2404 2405 subsys_initcall(send_signal_irq_work_init); 2406 2407 #ifdef CONFIG_MODULES 2408 static int bpf_event_notify(struct notifier_block *nb, unsigned long op, 2409 void *module) 2410 { 2411 struct bpf_trace_module *btm, *tmp; 2412 struct module *mod = module; 2413 int ret = 0; 2414 2415 if (mod->num_bpf_raw_events == 0 || 2416 (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING)) 2417 goto out; 2418 2419 mutex_lock(&bpf_module_mutex); 2420 2421 switch (op) { 2422 case MODULE_STATE_COMING: 2423 btm = kzalloc(sizeof(*btm), GFP_KERNEL); 2424 if (btm) { 2425 btm->module = module; 2426 list_add(&btm->list, &bpf_trace_modules); 2427 } else { 2428 ret = -ENOMEM; 2429 } 2430 break; 2431 case MODULE_STATE_GOING: 2432 list_for_each_entry_safe(btm, tmp, &bpf_trace_modules, list) { 2433 if (btm->module == module) { 2434 list_del(&btm->list); 2435 kfree(btm); 2436 break; 2437 } 2438 } 2439 break; 2440 } 2441 2442 mutex_unlock(&bpf_module_mutex); 2443 2444 out: 2445 return notifier_from_errno(ret); 2446 } 2447 2448 static struct notifier_block bpf_module_nb = { 2449 .notifier_call = bpf_event_notify, 2450 }; 2451 2452 static int __init bpf_event_init(void) 2453 { 2454 register_module_notifier(&bpf_module_nb); 2455 return 0; 2456 } 2457 2458 fs_initcall(bpf_event_init); 2459 #endif /* CONFIG_MODULES */ 2460 2461 #ifdef CONFIG_FPROBE 2462 struct bpf_kprobe_multi_link { 2463 struct bpf_link link; 2464 struct fprobe fp; 2465 unsigned long *addrs; 2466 u64 *cookies; 2467 u32 cnt; 2468 u32 mods_cnt; 2469 struct module **mods; 2470 }; 2471 2472 struct bpf_kprobe_multi_run_ctx { 2473 struct bpf_run_ctx run_ctx; 2474 struct bpf_kprobe_multi_link *link; 2475 unsigned long entry_ip; 2476 }; 2477 2478 struct user_syms { 2479 const char **syms; 2480 char *buf; 2481 }; 2482 2483 static int copy_user_syms(struct user_syms *us, unsigned long __user *usyms, u32 cnt) 2484 { 2485 unsigned long __user usymbol; 2486 const char **syms = NULL; 2487 char *buf = NULL, *p; 2488 int err = -ENOMEM; 2489 unsigned int i; 2490 2491 syms = kvmalloc_array(cnt, sizeof(*syms), GFP_KERNEL); 2492 if (!syms) 2493 goto error; 2494 2495 buf = kvmalloc_array(cnt, KSYM_NAME_LEN, GFP_KERNEL); 2496 if (!buf) 2497 goto error; 2498 2499 for (p = buf, i = 0; i < cnt; i++) { 2500 if (__get_user(usymbol, usyms + i)) { 2501 err = -EFAULT; 2502 goto error; 2503 } 2504 err = strncpy_from_user(p, (const char __user *) usymbol, KSYM_NAME_LEN); 2505 if (err == KSYM_NAME_LEN) 2506 err = -E2BIG; 2507 if (err < 0) 2508 goto error; 2509 syms[i] = p; 2510 p += err + 1; 2511 } 2512 2513 us->syms = syms; 2514 us->buf = buf; 2515 return 0; 2516 2517 error: 2518 if (err) { 2519 kvfree(syms); 2520 kvfree(buf); 2521 } 2522 return err; 2523 } 2524 2525 static void kprobe_multi_put_modules(struct module **mods, u32 cnt) 2526 { 2527 u32 i; 2528 2529 for (i = 0; i < cnt; i++) 2530 module_put(mods[i]); 2531 } 2532 2533 static void free_user_syms(struct user_syms *us) 2534 { 2535 kvfree(us->syms); 2536 kvfree(us->buf); 2537 } 2538 2539 static void bpf_kprobe_multi_link_release(struct bpf_link *link) 2540 { 2541 struct bpf_kprobe_multi_link *kmulti_link; 2542 2543 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); 2544 unregister_fprobe(&kmulti_link->fp); 2545 kprobe_multi_put_modules(kmulti_link->mods, kmulti_link->mods_cnt); 2546 } 2547 2548 static void bpf_kprobe_multi_link_dealloc(struct bpf_link *link) 2549 { 2550 struct bpf_kprobe_multi_link *kmulti_link; 2551 2552 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); 2553 kvfree(kmulti_link->addrs); 2554 kvfree(kmulti_link->cookies); 2555 kfree(kmulti_link->mods); 2556 kfree(kmulti_link); 2557 } 2558 2559 static const struct bpf_link_ops bpf_kprobe_multi_link_lops = { 2560 .release = bpf_kprobe_multi_link_release, 2561 .dealloc = bpf_kprobe_multi_link_dealloc, 2562 }; 2563 2564 static void bpf_kprobe_multi_cookie_swap(void *a, void *b, int size, const void *priv) 2565 { 2566 const struct bpf_kprobe_multi_link *link = priv; 2567 unsigned long *addr_a = a, *addr_b = b; 2568 u64 *cookie_a, *cookie_b; 2569 2570 cookie_a = link->cookies + (addr_a - link->addrs); 2571 cookie_b = link->cookies + (addr_b - link->addrs); 2572 2573 /* swap addr_a/addr_b and cookie_a/cookie_b values */ 2574 swap(*addr_a, *addr_b); 2575 swap(*cookie_a, *cookie_b); 2576 } 2577 2578 static int bpf_kprobe_multi_addrs_cmp(const void *a, const void *b) 2579 { 2580 const unsigned long *addr_a = a, *addr_b = b; 2581 2582 if (*addr_a == *addr_b) 2583 return 0; 2584 return *addr_a < *addr_b ? -1 : 1; 2585 } 2586 2587 static int bpf_kprobe_multi_cookie_cmp(const void *a, const void *b, const void *priv) 2588 { 2589 return bpf_kprobe_multi_addrs_cmp(a, b); 2590 } 2591 2592 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx) 2593 { 2594 struct bpf_kprobe_multi_run_ctx *run_ctx; 2595 struct bpf_kprobe_multi_link *link; 2596 u64 *cookie, entry_ip; 2597 unsigned long *addr; 2598 2599 if (WARN_ON_ONCE(!ctx)) 2600 return 0; 2601 run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, run_ctx); 2602 link = run_ctx->link; 2603 if (!link->cookies) 2604 return 0; 2605 entry_ip = run_ctx->entry_ip; 2606 addr = bsearch(&entry_ip, link->addrs, link->cnt, sizeof(entry_ip), 2607 bpf_kprobe_multi_addrs_cmp); 2608 if (!addr) 2609 return 0; 2610 cookie = link->cookies + (addr - link->addrs); 2611 return *cookie; 2612 } 2613 2614 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 2615 { 2616 struct bpf_kprobe_multi_run_ctx *run_ctx; 2617 2618 run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, run_ctx); 2619 return run_ctx->entry_ip; 2620 } 2621 2622 static int 2623 kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link, 2624 unsigned long entry_ip, struct pt_regs *regs) 2625 { 2626 struct bpf_kprobe_multi_run_ctx run_ctx = { 2627 .link = link, 2628 .entry_ip = entry_ip, 2629 }; 2630 struct bpf_run_ctx *old_run_ctx; 2631 int err; 2632 2633 if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) { 2634 err = 0; 2635 goto out; 2636 } 2637 2638 migrate_disable(); 2639 rcu_read_lock(); 2640 old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx); 2641 err = bpf_prog_run(link->link.prog, regs); 2642 bpf_reset_run_ctx(old_run_ctx); 2643 rcu_read_unlock(); 2644 migrate_enable(); 2645 2646 out: 2647 __this_cpu_dec(bpf_prog_active); 2648 return err; 2649 } 2650 2651 static void 2652 kprobe_multi_link_handler(struct fprobe *fp, unsigned long fentry_ip, 2653 struct pt_regs *regs) 2654 { 2655 struct bpf_kprobe_multi_link *link; 2656 2657 link = container_of(fp, struct bpf_kprobe_multi_link, fp); 2658 kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), regs); 2659 } 2660 2661 static int symbols_cmp_r(const void *a, const void *b, const void *priv) 2662 { 2663 const char **str_a = (const char **) a; 2664 const char **str_b = (const char **) b; 2665 2666 return strcmp(*str_a, *str_b); 2667 } 2668 2669 struct multi_symbols_sort { 2670 const char **funcs; 2671 u64 *cookies; 2672 }; 2673 2674 static void symbols_swap_r(void *a, void *b, int size, const void *priv) 2675 { 2676 const struct multi_symbols_sort *data = priv; 2677 const char **name_a = a, **name_b = b; 2678 2679 swap(*name_a, *name_b); 2680 2681 /* If defined, swap also related cookies. */ 2682 if (data->cookies) { 2683 u64 *cookie_a, *cookie_b; 2684 2685 cookie_a = data->cookies + (name_a - data->funcs); 2686 cookie_b = data->cookies + (name_b - data->funcs); 2687 swap(*cookie_a, *cookie_b); 2688 } 2689 } 2690 2691 struct module_addr_args { 2692 unsigned long *addrs; 2693 u32 addrs_cnt; 2694 struct module **mods; 2695 int mods_cnt; 2696 int mods_cap; 2697 }; 2698 2699 static int module_callback(void *data, const char *name, 2700 struct module *mod, unsigned long addr) 2701 { 2702 struct module_addr_args *args = data; 2703 struct module **mods; 2704 2705 /* We iterate all modules symbols and for each we: 2706 * - search for it in provided addresses array 2707 * - if found we check if we already have the module pointer stored 2708 * (we iterate modules sequentially, so we can check just the last 2709 * module pointer) 2710 * - take module reference and store it 2711 */ 2712 if (!bsearch(&addr, args->addrs, args->addrs_cnt, sizeof(addr), 2713 bpf_kprobe_multi_addrs_cmp)) 2714 return 0; 2715 2716 if (args->mods && args->mods[args->mods_cnt - 1] == mod) 2717 return 0; 2718 2719 if (args->mods_cnt == args->mods_cap) { 2720 args->mods_cap = max(16, args->mods_cap * 3 / 2); 2721 mods = krealloc_array(args->mods, args->mods_cap, sizeof(*mods), GFP_KERNEL); 2722 if (!mods) 2723 return -ENOMEM; 2724 args->mods = mods; 2725 } 2726 2727 if (!try_module_get(mod)) 2728 return -EINVAL; 2729 2730 args->mods[args->mods_cnt] = mod; 2731 args->mods_cnt++; 2732 return 0; 2733 } 2734 2735 static int get_modules_for_addrs(struct module ***mods, unsigned long *addrs, u32 addrs_cnt) 2736 { 2737 struct module_addr_args args = { 2738 .addrs = addrs, 2739 .addrs_cnt = addrs_cnt, 2740 }; 2741 int err; 2742 2743 /* We return either err < 0 in case of error, ... */ 2744 err = module_kallsyms_on_each_symbol(module_callback, &args); 2745 if (err) { 2746 kprobe_multi_put_modules(args.mods, args.mods_cnt); 2747 kfree(args.mods); 2748 return err; 2749 } 2750 2751 /* or number of modules found if everything is ok. */ 2752 *mods = args.mods; 2753 return args.mods_cnt; 2754 } 2755 2756 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 2757 { 2758 struct bpf_kprobe_multi_link *link = NULL; 2759 struct bpf_link_primer link_primer; 2760 void __user *ucookies; 2761 unsigned long *addrs; 2762 u32 flags, cnt, size; 2763 void __user *uaddrs; 2764 u64 *cookies = NULL; 2765 void __user *usyms; 2766 int err; 2767 2768 /* no support for 32bit archs yet */ 2769 if (sizeof(u64) != sizeof(void *)) 2770 return -EOPNOTSUPP; 2771 2772 if (prog->expected_attach_type != BPF_TRACE_KPROBE_MULTI) 2773 return -EINVAL; 2774 2775 flags = attr->link_create.kprobe_multi.flags; 2776 if (flags & ~BPF_F_KPROBE_MULTI_RETURN) 2777 return -EINVAL; 2778 2779 uaddrs = u64_to_user_ptr(attr->link_create.kprobe_multi.addrs); 2780 usyms = u64_to_user_ptr(attr->link_create.kprobe_multi.syms); 2781 if (!!uaddrs == !!usyms) 2782 return -EINVAL; 2783 2784 cnt = attr->link_create.kprobe_multi.cnt; 2785 if (!cnt) 2786 return -EINVAL; 2787 2788 size = cnt * sizeof(*addrs); 2789 addrs = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL); 2790 if (!addrs) 2791 return -ENOMEM; 2792 2793 ucookies = u64_to_user_ptr(attr->link_create.kprobe_multi.cookies); 2794 if (ucookies) { 2795 cookies = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL); 2796 if (!cookies) { 2797 err = -ENOMEM; 2798 goto error; 2799 } 2800 if (copy_from_user(cookies, ucookies, size)) { 2801 err = -EFAULT; 2802 goto error; 2803 } 2804 } 2805 2806 if (uaddrs) { 2807 if (copy_from_user(addrs, uaddrs, size)) { 2808 err = -EFAULT; 2809 goto error; 2810 } 2811 } else { 2812 struct multi_symbols_sort data = { 2813 .cookies = cookies, 2814 }; 2815 struct user_syms us; 2816 2817 err = copy_user_syms(&us, usyms, cnt); 2818 if (err) 2819 goto error; 2820 2821 if (cookies) 2822 data.funcs = us.syms; 2823 2824 sort_r(us.syms, cnt, sizeof(*us.syms), symbols_cmp_r, 2825 symbols_swap_r, &data); 2826 2827 err = ftrace_lookup_symbols(us.syms, cnt, addrs); 2828 free_user_syms(&us); 2829 if (err) 2830 goto error; 2831 } 2832 2833 link = kzalloc(sizeof(*link), GFP_KERNEL); 2834 if (!link) { 2835 err = -ENOMEM; 2836 goto error; 2837 } 2838 2839 bpf_link_init(&link->link, BPF_LINK_TYPE_KPROBE_MULTI, 2840 &bpf_kprobe_multi_link_lops, prog); 2841 2842 err = bpf_link_prime(&link->link, &link_primer); 2843 if (err) 2844 goto error; 2845 2846 if (flags & BPF_F_KPROBE_MULTI_RETURN) 2847 link->fp.exit_handler = kprobe_multi_link_handler; 2848 else 2849 link->fp.entry_handler = kprobe_multi_link_handler; 2850 2851 link->addrs = addrs; 2852 link->cookies = cookies; 2853 link->cnt = cnt; 2854 2855 if (cookies) { 2856 /* 2857 * Sorting addresses will trigger sorting cookies as well 2858 * (check bpf_kprobe_multi_cookie_swap). This way we can 2859 * find cookie based on the address in bpf_get_attach_cookie 2860 * helper. 2861 */ 2862 sort_r(addrs, cnt, sizeof(*addrs), 2863 bpf_kprobe_multi_cookie_cmp, 2864 bpf_kprobe_multi_cookie_swap, 2865 link); 2866 } else { 2867 /* 2868 * We need to sort addrs array even if there are no cookies 2869 * provided, to allow bsearch in get_modules_for_addrs. 2870 */ 2871 sort(addrs, cnt, sizeof(*addrs), 2872 bpf_kprobe_multi_addrs_cmp, NULL); 2873 } 2874 2875 err = get_modules_for_addrs(&link->mods, addrs, cnt); 2876 if (err < 0) { 2877 bpf_link_cleanup(&link_primer); 2878 return err; 2879 } 2880 link->mods_cnt = err; 2881 2882 err = register_fprobe_ips(&link->fp, addrs, cnt); 2883 if (err) { 2884 kprobe_multi_put_modules(link->mods, link->mods_cnt); 2885 bpf_link_cleanup(&link_primer); 2886 return err; 2887 } 2888 2889 return bpf_link_settle(&link_primer); 2890 2891 error: 2892 kfree(link); 2893 kvfree(addrs); 2894 kvfree(cookies); 2895 return err; 2896 } 2897 #else /* !CONFIG_FPROBE */ 2898 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 2899 { 2900 return -EOPNOTSUPP; 2901 } 2902 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx) 2903 { 2904 return 0; 2905 } 2906 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 2907 { 2908 return 0; 2909 } 2910 #endif 2911