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_perf_event.h> 10 #include <linux/btf.h> 11 #include <linux/filter.h> 12 #include <linux/uaccess.h> 13 #include <linux/ctype.h> 14 #include <linux/kprobes.h> 15 #include <linux/spinlock.h> 16 #include <linux/syscalls.h> 17 #include <linux/error-injection.h> 18 #include <linux/btf_ids.h> 19 #include <linux/bpf_lsm.h> 20 #include <linux/fprobe.h> 21 #include <linux/bsearch.h> 22 #include <linux/sort.h> 23 #include <linux/key.h> 24 #include <linux/verification.h> 25 26 #include <net/bpf_sk_storage.h> 27 28 #include <uapi/linux/bpf.h> 29 #include <uapi/linux/btf.h> 30 31 #include <asm/tlb.h> 32 33 #include "trace_probe.h" 34 #include "trace.h" 35 36 #define CREATE_TRACE_POINTS 37 #include "bpf_trace.h" 38 39 #define bpf_event_rcu_dereference(p) \ 40 rcu_dereference_protected(p, lockdep_is_held(&bpf_event_mutex)) 41 42 #ifdef CONFIG_MODULES 43 struct bpf_trace_module { 44 struct module *module; 45 struct list_head list; 46 }; 47 48 static LIST_HEAD(bpf_trace_modules); 49 static DEFINE_MUTEX(bpf_module_mutex); 50 51 static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name) 52 { 53 struct bpf_raw_event_map *btp, *ret = NULL; 54 struct bpf_trace_module *btm; 55 unsigned int i; 56 57 mutex_lock(&bpf_module_mutex); 58 list_for_each_entry(btm, &bpf_trace_modules, list) { 59 for (i = 0; i < btm->module->num_bpf_raw_events; ++i) { 60 btp = &btm->module->bpf_raw_events[i]; 61 if (!strcmp(btp->tp->name, name)) { 62 if (try_module_get(btm->module)) 63 ret = btp; 64 goto out; 65 } 66 } 67 } 68 out: 69 mutex_unlock(&bpf_module_mutex); 70 return ret; 71 } 72 #else 73 static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name) 74 { 75 return NULL; 76 } 77 #endif /* CONFIG_MODULES */ 78 79 u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); 80 u64 bpf_get_stack(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); 81 82 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size, 83 u64 flags, const struct btf **btf, 84 s32 *btf_id); 85 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx); 86 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx); 87 88 /** 89 * trace_call_bpf - invoke BPF program 90 * @call: tracepoint event 91 * @ctx: opaque context pointer 92 * 93 * kprobe handlers execute BPF programs via this helper. 94 * Can be used from static tracepoints in the future. 95 * 96 * Return: BPF programs always return an integer which is interpreted by 97 * kprobe handler as: 98 * 0 - return from kprobe (event is filtered out) 99 * 1 - store kprobe event into ring buffer 100 * Other values are reserved and currently alias to 1 101 */ 102 unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx) 103 { 104 unsigned int ret; 105 106 cant_sleep(); 107 108 if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) { 109 /* 110 * since some bpf program is already running on this cpu, 111 * don't call into another bpf program (same or different) 112 * and don't send kprobe event into ring-buffer, 113 * so return zero here 114 */ 115 ret = 0; 116 goto out; 117 } 118 119 /* 120 * Instead of moving rcu_read_lock/rcu_dereference/rcu_read_unlock 121 * to all call sites, we did a bpf_prog_array_valid() there to check 122 * whether call->prog_array is empty or not, which is 123 * a heuristic to speed up execution. 124 * 125 * If bpf_prog_array_valid() fetched prog_array was 126 * non-NULL, we go into trace_call_bpf() and do the actual 127 * proper rcu_dereference() under RCU lock. 128 * If it turns out that prog_array is NULL then, we bail out. 129 * For the opposite, if the bpf_prog_array_valid() fetched pointer 130 * was NULL, you'll skip the prog_array with the risk of missing 131 * out of events when it was updated in between this and the 132 * rcu_dereference() which is accepted risk. 133 */ 134 rcu_read_lock(); 135 ret = bpf_prog_run_array(rcu_dereference(call->prog_array), 136 ctx, bpf_prog_run); 137 rcu_read_unlock(); 138 139 out: 140 __this_cpu_dec(bpf_prog_active); 141 142 return ret; 143 } 144 145 #ifdef CONFIG_BPF_KPROBE_OVERRIDE 146 BPF_CALL_2(bpf_override_return, struct pt_regs *, regs, unsigned long, rc) 147 { 148 regs_set_return_value(regs, rc); 149 override_function_with_return(regs); 150 return 0; 151 } 152 153 static const struct bpf_func_proto bpf_override_return_proto = { 154 .func = bpf_override_return, 155 .gpl_only = true, 156 .ret_type = RET_INTEGER, 157 .arg1_type = ARG_PTR_TO_CTX, 158 .arg2_type = ARG_ANYTHING, 159 }; 160 #endif 161 162 static __always_inline int 163 bpf_probe_read_user_common(void *dst, u32 size, const void __user *unsafe_ptr) 164 { 165 int ret; 166 167 ret = copy_from_user_nofault(dst, unsafe_ptr, size); 168 if (unlikely(ret < 0)) 169 memset(dst, 0, size); 170 return ret; 171 } 172 173 BPF_CALL_3(bpf_probe_read_user, void *, dst, u32, size, 174 const void __user *, unsafe_ptr) 175 { 176 return bpf_probe_read_user_common(dst, size, unsafe_ptr); 177 } 178 179 const struct bpf_func_proto bpf_probe_read_user_proto = { 180 .func = bpf_probe_read_user, 181 .gpl_only = true, 182 .ret_type = RET_INTEGER, 183 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 184 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 185 .arg3_type = ARG_ANYTHING, 186 }; 187 188 static __always_inline int 189 bpf_probe_read_user_str_common(void *dst, u32 size, 190 const void __user *unsafe_ptr) 191 { 192 int ret; 193 194 /* 195 * NB: We rely on strncpy_from_user() not copying junk past the NUL 196 * terminator into `dst`. 197 * 198 * strncpy_from_user() does long-sized strides in the fast path. If the 199 * strncpy does not mask out the bytes after the NUL in `unsafe_ptr`, 200 * then there could be junk after the NUL in `dst`. If user takes `dst` 201 * and keys a hash map with it, then semantically identical strings can 202 * occupy multiple entries in the map. 203 */ 204 ret = strncpy_from_user_nofault(dst, unsafe_ptr, size); 205 if (unlikely(ret < 0)) 206 memset(dst, 0, size); 207 return ret; 208 } 209 210 BPF_CALL_3(bpf_probe_read_user_str, void *, dst, u32, size, 211 const void __user *, unsafe_ptr) 212 { 213 return bpf_probe_read_user_str_common(dst, size, unsafe_ptr); 214 } 215 216 const struct bpf_func_proto bpf_probe_read_user_str_proto = { 217 .func = bpf_probe_read_user_str, 218 .gpl_only = true, 219 .ret_type = RET_INTEGER, 220 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 221 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 222 .arg3_type = ARG_ANYTHING, 223 }; 224 225 static __always_inline int 226 bpf_probe_read_kernel_common(void *dst, u32 size, const void *unsafe_ptr) 227 { 228 int ret; 229 230 ret = copy_from_kernel_nofault(dst, unsafe_ptr, size); 231 if (unlikely(ret < 0)) 232 memset(dst, 0, size); 233 return ret; 234 } 235 236 BPF_CALL_3(bpf_probe_read_kernel, void *, dst, u32, size, 237 const void *, unsafe_ptr) 238 { 239 return bpf_probe_read_kernel_common(dst, size, unsafe_ptr); 240 } 241 242 const struct bpf_func_proto bpf_probe_read_kernel_proto = { 243 .func = bpf_probe_read_kernel, 244 .gpl_only = true, 245 .ret_type = RET_INTEGER, 246 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 247 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 248 .arg3_type = ARG_ANYTHING, 249 }; 250 251 static __always_inline int 252 bpf_probe_read_kernel_str_common(void *dst, u32 size, const void *unsafe_ptr) 253 { 254 int ret; 255 256 /* 257 * The strncpy_from_kernel_nofault() call will likely not fill the 258 * entire buffer, but that's okay in this circumstance as we're probing 259 * arbitrary memory anyway similar to bpf_probe_read_*() and might 260 * as well probe the stack. Thus, memory is explicitly cleared 261 * only in error case, so that improper users ignoring return 262 * code altogether don't copy garbage; otherwise length of string 263 * is returned that can be used for bpf_perf_event_output() et al. 264 */ 265 ret = strncpy_from_kernel_nofault(dst, unsafe_ptr, size); 266 if (unlikely(ret < 0)) 267 memset(dst, 0, size); 268 return ret; 269 } 270 271 BPF_CALL_3(bpf_probe_read_kernel_str, void *, dst, u32, size, 272 const void *, unsafe_ptr) 273 { 274 return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr); 275 } 276 277 const struct bpf_func_proto bpf_probe_read_kernel_str_proto = { 278 .func = bpf_probe_read_kernel_str, 279 .gpl_only = true, 280 .ret_type = RET_INTEGER, 281 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 282 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 283 .arg3_type = ARG_ANYTHING, 284 }; 285 286 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 287 BPF_CALL_3(bpf_probe_read_compat, void *, dst, u32, size, 288 const void *, unsafe_ptr) 289 { 290 if ((unsigned long)unsafe_ptr < TASK_SIZE) { 291 return bpf_probe_read_user_common(dst, size, 292 (__force void __user *)unsafe_ptr); 293 } 294 return bpf_probe_read_kernel_common(dst, size, unsafe_ptr); 295 } 296 297 static const struct bpf_func_proto bpf_probe_read_compat_proto = { 298 .func = bpf_probe_read_compat, 299 .gpl_only = true, 300 .ret_type = RET_INTEGER, 301 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 302 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 303 .arg3_type = ARG_ANYTHING, 304 }; 305 306 BPF_CALL_3(bpf_probe_read_compat_str, void *, dst, u32, size, 307 const void *, unsafe_ptr) 308 { 309 if ((unsigned long)unsafe_ptr < TASK_SIZE) { 310 return bpf_probe_read_user_str_common(dst, size, 311 (__force void __user *)unsafe_ptr); 312 } 313 return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr); 314 } 315 316 static const struct bpf_func_proto bpf_probe_read_compat_str_proto = { 317 .func = bpf_probe_read_compat_str, 318 .gpl_only = true, 319 .ret_type = RET_INTEGER, 320 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 321 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 322 .arg3_type = ARG_ANYTHING, 323 }; 324 #endif /* CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE */ 325 326 BPF_CALL_3(bpf_probe_write_user, void __user *, unsafe_ptr, const void *, src, 327 u32, size) 328 { 329 /* 330 * Ensure we're in user context which is safe for the helper to 331 * run. This helper has no business in a kthread. 332 * 333 * access_ok() should prevent writing to non-user memory, but in 334 * some situations (nommu, temporary switch, etc) access_ok() does 335 * not provide enough validation, hence the check on KERNEL_DS. 336 * 337 * nmi_uaccess_okay() ensures the probe is not run in an interim 338 * state, when the task or mm are switched. This is specifically 339 * required to prevent the use of temporary mm. 340 */ 341 342 if (unlikely(in_interrupt() || 343 current->flags & (PF_KTHREAD | PF_EXITING))) 344 return -EPERM; 345 if (unlikely(!nmi_uaccess_okay())) 346 return -EPERM; 347 348 return copy_to_user_nofault(unsafe_ptr, src, size); 349 } 350 351 static const struct bpf_func_proto bpf_probe_write_user_proto = { 352 .func = bpf_probe_write_user, 353 .gpl_only = true, 354 .ret_type = RET_INTEGER, 355 .arg1_type = ARG_ANYTHING, 356 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 357 .arg3_type = ARG_CONST_SIZE, 358 }; 359 360 static const struct bpf_func_proto *bpf_get_probe_write_proto(void) 361 { 362 if (!capable(CAP_SYS_ADMIN)) 363 return NULL; 364 365 pr_warn_ratelimited("%s[%d] is installing a program with bpf_probe_write_user helper that may corrupt user memory!", 366 current->comm, task_pid_nr(current)); 367 368 return &bpf_probe_write_user_proto; 369 } 370 371 static DEFINE_RAW_SPINLOCK(trace_printk_lock); 372 373 #define MAX_TRACE_PRINTK_VARARGS 3 374 #define BPF_TRACE_PRINTK_SIZE 1024 375 376 BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1, 377 u64, arg2, u64, arg3) 378 { 379 u64 args[MAX_TRACE_PRINTK_VARARGS] = { arg1, arg2, arg3 }; 380 u32 *bin_args; 381 static char buf[BPF_TRACE_PRINTK_SIZE]; 382 unsigned long flags; 383 int ret; 384 385 ret = bpf_bprintf_prepare(fmt, fmt_size, args, &bin_args, 386 MAX_TRACE_PRINTK_VARARGS); 387 if (ret < 0) 388 return ret; 389 390 raw_spin_lock_irqsave(&trace_printk_lock, flags); 391 ret = bstr_printf(buf, sizeof(buf), fmt, bin_args); 392 393 trace_bpf_trace_printk(buf); 394 raw_spin_unlock_irqrestore(&trace_printk_lock, flags); 395 396 bpf_bprintf_cleanup(); 397 398 return ret; 399 } 400 401 static const struct bpf_func_proto bpf_trace_printk_proto = { 402 .func = bpf_trace_printk, 403 .gpl_only = true, 404 .ret_type = RET_INTEGER, 405 .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY, 406 .arg2_type = ARG_CONST_SIZE, 407 }; 408 409 static void __set_printk_clr_event(void) 410 { 411 /* 412 * This program might be calling bpf_trace_printk, 413 * so enable the associated bpf_trace/bpf_trace_printk event. 414 * Repeat this each time as it is possible a user has 415 * disabled bpf_trace_printk events. By loading a program 416 * calling bpf_trace_printk() however the user has expressed 417 * the intent to see such events. 418 */ 419 if (trace_set_clr_event("bpf_trace", "bpf_trace_printk", 1)) 420 pr_warn_ratelimited("could not enable bpf_trace_printk events"); 421 } 422 423 const struct bpf_func_proto *bpf_get_trace_printk_proto(void) 424 { 425 __set_printk_clr_event(); 426 return &bpf_trace_printk_proto; 427 } 428 429 BPF_CALL_4(bpf_trace_vprintk, char *, fmt, u32, fmt_size, const void *, data, 430 u32, data_len) 431 { 432 static char buf[BPF_TRACE_PRINTK_SIZE]; 433 unsigned long flags; 434 int ret, num_args; 435 u32 *bin_args; 436 437 if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 || 438 (data_len && !data)) 439 return -EINVAL; 440 num_args = data_len / 8; 441 442 ret = bpf_bprintf_prepare(fmt, fmt_size, data, &bin_args, num_args); 443 if (ret < 0) 444 return ret; 445 446 raw_spin_lock_irqsave(&trace_printk_lock, flags); 447 ret = bstr_printf(buf, sizeof(buf), fmt, bin_args); 448 449 trace_bpf_trace_printk(buf); 450 raw_spin_unlock_irqrestore(&trace_printk_lock, flags); 451 452 bpf_bprintf_cleanup(); 453 454 return ret; 455 } 456 457 static const struct bpf_func_proto bpf_trace_vprintk_proto = { 458 .func = bpf_trace_vprintk, 459 .gpl_only = true, 460 .ret_type = RET_INTEGER, 461 .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY, 462 .arg2_type = ARG_CONST_SIZE, 463 .arg3_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY, 464 .arg4_type = ARG_CONST_SIZE_OR_ZERO, 465 }; 466 467 const struct bpf_func_proto *bpf_get_trace_vprintk_proto(void) 468 { 469 __set_printk_clr_event(); 470 return &bpf_trace_vprintk_proto; 471 } 472 473 BPF_CALL_5(bpf_seq_printf, struct seq_file *, m, char *, fmt, u32, fmt_size, 474 const void *, data, u32, data_len) 475 { 476 int err, num_args; 477 u32 *bin_args; 478 479 if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 || 480 (data_len && !data)) 481 return -EINVAL; 482 num_args = data_len / 8; 483 484 err = bpf_bprintf_prepare(fmt, fmt_size, data, &bin_args, num_args); 485 if (err < 0) 486 return err; 487 488 seq_bprintf(m, fmt, bin_args); 489 490 bpf_bprintf_cleanup(); 491 492 return seq_has_overflowed(m) ? -EOVERFLOW : 0; 493 } 494 495 BTF_ID_LIST_SINGLE(btf_seq_file_ids, struct, seq_file) 496 497 static const struct bpf_func_proto bpf_seq_printf_proto = { 498 .func = bpf_seq_printf, 499 .gpl_only = true, 500 .ret_type = RET_INTEGER, 501 .arg1_type = ARG_PTR_TO_BTF_ID, 502 .arg1_btf_id = &btf_seq_file_ids[0], 503 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 504 .arg3_type = ARG_CONST_SIZE, 505 .arg4_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY, 506 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 507 }; 508 509 BPF_CALL_3(bpf_seq_write, struct seq_file *, m, const void *, data, u32, len) 510 { 511 return seq_write(m, data, len) ? -EOVERFLOW : 0; 512 } 513 514 static const struct bpf_func_proto bpf_seq_write_proto = { 515 .func = bpf_seq_write, 516 .gpl_only = true, 517 .ret_type = RET_INTEGER, 518 .arg1_type = ARG_PTR_TO_BTF_ID, 519 .arg1_btf_id = &btf_seq_file_ids[0], 520 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 521 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 522 }; 523 524 BPF_CALL_4(bpf_seq_printf_btf, struct seq_file *, m, struct btf_ptr *, ptr, 525 u32, btf_ptr_size, u64, flags) 526 { 527 const struct btf *btf; 528 s32 btf_id; 529 int ret; 530 531 ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id); 532 if (ret) 533 return ret; 534 535 return btf_type_seq_show_flags(btf, btf_id, ptr->ptr, m, flags); 536 } 537 538 static const struct bpf_func_proto bpf_seq_printf_btf_proto = { 539 .func = bpf_seq_printf_btf, 540 .gpl_only = true, 541 .ret_type = RET_INTEGER, 542 .arg1_type = ARG_PTR_TO_BTF_ID, 543 .arg1_btf_id = &btf_seq_file_ids[0], 544 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 545 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 546 .arg4_type = ARG_ANYTHING, 547 }; 548 549 static __always_inline int 550 get_map_perf_counter(struct bpf_map *map, u64 flags, 551 u64 *value, u64 *enabled, u64 *running) 552 { 553 struct bpf_array *array = container_of(map, struct bpf_array, map); 554 unsigned int cpu = smp_processor_id(); 555 u64 index = flags & BPF_F_INDEX_MASK; 556 struct bpf_event_entry *ee; 557 558 if (unlikely(flags & ~(BPF_F_INDEX_MASK))) 559 return -EINVAL; 560 if (index == BPF_F_CURRENT_CPU) 561 index = cpu; 562 if (unlikely(index >= array->map.max_entries)) 563 return -E2BIG; 564 565 ee = READ_ONCE(array->ptrs[index]); 566 if (!ee) 567 return -ENOENT; 568 569 return perf_event_read_local(ee->event, value, enabled, running); 570 } 571 572 BPF_CALL_2(bpf_perf_event_read, struct bpf_map *, map, u64, flags) 573 { 574 u64 value = 0; 575 int err; 576 577 err = get_map_perf_counter(map, flags, &value, NULL, NULL); 578 /* 579 * this api is ugly since we miss [-22..-2] range of valid 580 * counter values, but that's uapi 581 */ 582 if (err) 583 return err; 584 return value; 585 } 586 587 static const struct bpf_func_proto bpf_perf_event_read_proto = { 588 .func = bpf_perf_event_read, 589 .gpl_only = true, 590 .ret_type = RET_INTEGER, 591 .arg1_type = ARG_CONST_MAP_PTR, 592 .arg2_type = ARG_ANYTHING, 593 }; 594 595 BPF_CALL_4(bpf_perf_event_read_value, struct bpf_map *, map, u64, flags, 596 struct bpf_perf_event_value *, buf, u32, size) 597 { 598 int err = -EINVAL; 599 600 if (unlikely(size != sizeof(struct bpf_perf_event_value))) 601 goto clear; 602 err = get_map_perf_counter(map, flags, &buf->counter, &buf->enabled, 603 &buf->running); 604 if (unlikely(err)) 605 goto clear; 606 return 0; 607 clear: 608 memset(buf, 0, size); 609 return err; 610 } 611 612 static const struct bpf_func_proto bpf_perf_event_read_value_proto = { 613 .func = bpf_perf_event_read_value, 614 .gpl_only = true, 615 .ret_type = RET_INTEGER, 616 .arg1_type = ARG_CONST_MAP_PTR, 617 .arg2_type = ARG_ANYTHING, 618 .arg3_type = ARG_PTR_TO_UNINIT_MEM, 619 .arg4_type = ARG_CONST_SIZE, 620 }; 621 622 static __always_inline u64 623 __bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map, 624 u64 flags, struct perf_sample_data *sd) 625 { 626 struct bpf_array *array = container_of(map, struct bpf_array, map); 627 unsigned int cpu = smp_processor_id(); 628 u64 index = flags & BPF_F_INDEX_MASK; 629 struct bpf_event_entry *ee; 630 struct perf_event *event; 631 632 if (index == BPF_F_CURRENT_CPU) 633 index = cpu; 634 if (unlikely(index >= array->map.max_entries)) 635 return -E2BIG; 636 637 ee = READ_ONCE(array->ptrs[index]); 638 if (!ee) 639 return -ENOENT; 640 641 event = ee->event; 642 if (unlikely(event->attr.type != PERF_TYPE_SOFTWARE || 643 event->attr.config != PERF_COUNT_SW_BPF_OUTPUT)) 644 return -EINVAL; 645 646 if (unlikely(event->oncpu != cpu)) 647 return -EOPNOTSUPP; 648 649 return perf_event_output(event, sd, regs); 650 } 651 652 /* 653 * Support executing tracepoints in normal, irq, and nmi context that each call 654 * bpf_perf_event_output 655 */ 656 struct bpf_trace_sample_data { 657 struct perf_sample_data sds[3]; 658 }; 659 660 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_trace_sds); 661 static DEFINE_PER_CPU(int, bpf_trace_nest_level); 662 BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map, 663 u64, flags, void *, data, u64, size) 664 { 665 struct bpf_trace_sample_data *sds = this_cpu_ptr(&bpf_trace_sds); 666 int nest_level = this_cpu_inc_return(bpf_trace_nest_level); 667 struct perf_raw_record raw = { 668 .frag = { 669 .size = size, 670 .data = data, 671 }, 672 }; 673 struct perf_sample_data *sd; 674 int err; 675 676 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(sds->sds))) { 677 err = -EBUSY; 678 goto out; 679 } 680 681 sd = &sds->sds[nest_level - 1]; 682 683 if (unlikely(flags & ~(BPF_F_INDEX_MASK))) { 684 err = -EINVAL; 685 goto out; 686 } 687 688 perf_sample_data_init(sd, 0, 0); 689 sd->raw = &raw; 690 sd->sample_flags |= PERF_SAMPLE_RAW; 691 692 err = __bpf_perf_event_output(regs, map, flags, sd); 693 694 out: 695 this_cpu_dec(bpf_trace_nest_level); 696 return err; 697 } 698 699 static const struct bpf_func_proto bpf_perf_event_output_proto = { 700 .func = bpf_perf_event_output, 701 .gpl_only = true, 702 .ret_type = RET_INTEGER, 703 .arg1_type = ARG_PTR_TO_CTX, 704 .arg2_type = ARG_CONST_MAP_PTR, 705 .arg3_type = ARG_ANYTHING, 706 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, 707 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 708 }; 709 710 static DEFINE_PER_CPU(int, bpf_event_output_nest_level); 711 struct bpf_nested_pt_regs { 712 struct pt_regs regs[3]; 713 }; 714 static DEFINE_PER_CPU(struct bpf_nested_pt_regs, bpf_pt_regs); 715 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_misc_sds); 716 717 u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size, 718 void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy) 719 { 720 int nest_level = this_cpu_inc_return(bpf_event_output_nest_level); 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 u64 ret; 738 739 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(bpf_misc_sds.sds))) { 740 ret = -EBUSY; 741 goto out; 742 } 743 sd = this_cpu_ptr(&bpf_misc_sds.sds[nest_level - 1]); 744 regs = this_cpu_ptr(&bpf_pt_regs.regs[nest_level - 1]); 745 746 perf_fetch_caller_regs(regs); 747 perf_sample_data_init(sd, 0, 0); 748 sd->raw = &raw; 749 sd->sample_flags |= PERF_SAMPLE_RAW; 750 751 ret = __bpf_perf_event_output(regs, map, flags, sd); 752 out: 753 this_cpu_dec(bpf_event_output_nest_level); 754 return ret; 755 } 756 757 BPF_CALL_0(bpf_get_current_task) 758 { 759 return (long) current; 760 } 761 762 const struct bpf_func_proto bpf_get_current_task_proto = { 763 .func = bpf_get_current_task, 764 .gpl_only = true, 765 .ret_type = RET_INTEGER, 766 }; 767 768 BPF_CALL_0(bpf_get_current_task_btf) 769 { 770 return (unsigned long) current; 771 } 772 773 const struct bpf_func_proto bpf_get_current_task_btf_proto = { 774 .func = bpf_get_current_task_btf, 775 .gpl_only = true, 776 .ret_type = RET_PTR_TO_BTF_ID, 777 .ret_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK], 778 }; 779 780 BPF_CALL_1(bpf_task_pt_regs, struct task_struct *, task) 781 { 782 return (unsigned long) task_pt_regs(task); 783 } 784 785 BTF_ID_LIST(bpf_task_pt_regs_ids) 786 BTF_ID(struct, pt_regs) 787 788 const struct bpf_func_proto bpf_task_pt_regs_proto = { 789 .func = bpf_task_pt_regs, 790 .gpl_only = true, 791 .arg1_type = ARG_PTR_TO_BTF_ID, 792 .arg1_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK], 793 .ret_type = RET_PTR_TO_BTF_ID, 794 .ret_btf_id = &bpf_task_pt_regs_ids[0], 795 }; 796 797 BPF_CALL_2(bpf_current_task_under_cgroup, struct bpf_map *, map, u32, idx) 798 { 799 struct bpf_array *array = container_of(map, struct bpf_array, map); 800 struct cgroup *cgrp; 801 802 if (unlikely(idx >= array->map.max_entries)) 803 return -E2BIG; 804 805 cgrp = READ_ONCE(array->ptrs[idx]); 806 if (unlikely(!cgrp)) 807 return -EAGAIN; 808 809 return task_under_cgroup_hierarchy(current, cgrp); 810 } 811 812 static const struct bpf_func_proto bpf_current_task_under_cgroup_proto = { 813 .func = bpf_current_task_under_cgroup, 814 .gpl_only = false, 815 .ret_type = RET_INTEGER, 816 .arg1_type = ARG_CONST_MAP_PTR, 817 .arg2_type = ARG_ANYTHING, 818 }; 819 820 struct send_signal_irq_work { 821 struct irq_work irq_work; 822 struct task_struct *task; 823 u32 sig; 824 enum pid_type type; 825 }; 826 827 static DEFINE_PER_CPU(struct send_signal_irq_work, send_signal_work); 828 829 static void do_bpf_send_signal(struct irq_work *entry) 830 { 831 struct send_signal_irq_work *work; 832 833 work = container_of(entry, struct send_signal_irq_work, irq_work); 834 group_send_sig_info(work->sig, SEND_SIG_PRIV, work->task, work->type); 835 } 836 837 static int bpf_send_signal_common(u32 sig, enum pid_type type) 838 { 839 struct send_signal_irq_work *work = NULL; 840 841 /* Similar to bpf_probe_write_user, task needs to be 842 * in a sound condition and kernel memory access be 843 * permitted in order to send signal to the current 844 * task. 845 */ 846 if (unlikely(current->flags & (PF_KTHREAD | PF_EXITING))) 847 return -EPERM; 848 if (unlikely(!nmi_uaccess_okay())) 849 return -EPERM; 850 851 if (irqs_disabled()) { 852 /* Do an early check on signal validity. Otherwise, 853 * the error is lost in deferred irq_work. 854 */ 855 if (unlikely(!valid_signal(sig))) 856 return -EINVAL; 857 858 work = this_cpu_ptr(&send_signal_work); 859 if (irq_work_is_busy(&work->irq_work)) 860 return -EBUSY; 861 862 /* Add the current task, which is the target of sending signal, 863 * to the irq_work. The current task may change when queued 864 * irq works get executed. 865 */ 866 work->task = current; 867 work->sig = sig; 868 work->type = type; 869 irq_work_queue(&work->irq_work); 870 return 0; 871 } 872 873 return group_send_sig_info(sig, SEND_SIG_PRIV, current, type); 874 } 875 876 BPF_CALL_1(bpf_send_signal, u32, sig) 877 { 878 return bpf_send_signal_common(sig, PIDTYPE_TGID); 879 } 880 881 static const struct bpf_func_proto bpf_send_signal_proto = { 882 .func = bpf_send_signal, 883 .gpl_only = false, 884 .ret_type = RET_INTEGER, 885 .arg1_type = ARG_ANYTHING, 886 }; 887 888 BPF_CALL_1(bpf_send_signal_thread, u32, sig) 889 { 890 return bpf_send_signal_common(sig, PIDTYPE_PID); 891 } 892 893 static const struct bpf_func_proto bpf_send_signal_thread_proto = { 894 .func = bpf_send_signal_thread, 895 .gpl_only = false, 896 .ret_type = RET_INTEGER, 897 .arg1_type = ARG_ANYTHING, 898 }; 899 900 BPF_CALL_3(bpf_d_path, struct path *, path, char *, buf, u32, sz) 901 { 902 long len; 903 char *p; 904 905 if (!sz) 906 return 0; 907 908 p = d_path(path, buf, sz); 909 if (IS_ERR(p)) { 910 len = PTR_ERR(p); 911 } else { 912 len = buf + sz - p; 913 memmove(buf, p, len); 914 } 915 916 return len; 917 } 918 919 BTF_SET_START(btf_allowlist_d_path) 920 #ifdef CONFIG_SECURITY 921 BTF_ID(func, security_file_permission) 922 BTF_ID(func, security_inode_getattr) 923 BTF_ID(func, security_file_open) 924 #endif 925 #ifdef CONFIG_SECURITY_PATH 926 BTF_ID(func, security_path_truncate) 927 #endif 928 BTF_ID(func, vfs_truncate) 929 BTF_ID(func, vfs_fallocate) 930 BTF_ID(func, dentry_open) 931 BTF_ID(func, vfs_getattr) 932 BTF_ID(func, filp_close) 933 BTF_SET_END(btf_allowlist_d_path) 934 935 static bool bpf_d_path_allowed(const struct bpf_prog *prog) 936 { 937 if (prog->type == BPF_PROG_TYPE_TRACING && 938 prog->expected_attach_type == BPF_TRACE_ITER) 939 return true; 940 941 if (prog->type == BPF_PROG_TYPE_LSM) 942 return bpf_lsm_is_sleepable_hook(prog->aux->attach_btf_id); 943 944 return btf_id_set_contains(&btf_allowlist_d_path, 945 prog->aux->attach_btf_id); 946 } 947 948 BTF_ID_LIST_SINGLE(bpf_d_path_btf_ids, struct, path) 949 950 static const struct bpf_func_proto bpf_d_path_proto = { 951 .func = bpf_d_path, 952 .gpl_only = false, 953 .ret_type = RET_INTEGER, 954 .arg1_type = ARG_PTR_TO_BTF_ID, 955 .arg1_btf_id = &bpf_d_path_btf_ids[0], 956 .arg2_type = ARG_PTR_TO_MEM, 957 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 958 .allowed = bpf_d_path_allowed, 959 }; 960 961 #define BTF_F_ALL (BTF_F_COMPACT | BTF_F_NONAME | \ 962 BTF_F_PTR_RAW | BTF_F_ZERO) 963 964 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size, 965 u64 flags, const struct btf **btf, 966 s32 *btf_id) 967 { 968 const struct btf_type *t; 969 970 if (unlikely(flags & ~(BTF_F_ALL))) 971 return -EINVAL; 972 973 if (btf_ptr_size != sizeof(struct btf_ptr)) 974 return -EINVAL; 975 976 *btf = bpf_get_btf_vmlinux(); 977 978 if (IS_ERR_OR_NULL(*btf)) 979 return IS_ERR(*btf) ? PTR_ERR(*btf) : -EINVAL; 980 981 if (ptr->type_id > 0) 982 *btf_id = ptr->type_id; 983 else 984 return -EINVAL; 985 986 if (*btf_id > 0) 987 t = btf_type_by_id(*btf, *btf_id); 988 if (*btf_id <= 0 || !t) 989 return -ENOENT; 990 991 return 0; 992 } 993 994 BPF_CALL_5(bpf_snprintf_btf, char *, str, u32, str_size, struct btf_ptr *, ptr, 995 u32, btf_ptr_size, u64, flags) 996 { 997 const struct btf *btf; 998 s32 btf_id; 999 int ret; 1000 1001 ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id); 1002 if (ret) 1003 return ret; 1004 1005 return btf_type_snprintf_show(btf, btf_id, ptr->ptr, str, str_size, 1006 flags); 1007 } 1008 1009 const struct bpf_func_proto bpf_snprintf_btf_proto = { 1010 .func = bpf_snprintf_btf, 1011 .gpl_only = false, 1012 .ret_type = RET_INTEGER, 1013 .arg1_type = ARG_PTR_TO_MEM, 1014 .arg2_type = ARG_CONST_SIZE, 1015 .arg3_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1016 .arg4_type = ARG_CONST_SIZE, 1017 .arg5_type = ARG_ANYTHING, 1018 }; 1019 1020 BPF_CALL_1(bpf_get_func_ip_tracing, void *, ctx) 1021 { 1022 /* This helper call is inlined by verifier. */ 1023 return ((u64 *)ctx)[-2]; 1024 } 1025 1026 static const struct bpf_func_proto bpf_get_func_ip_proto_tracing = { 1027 .func = bpf_get_func_ip_tracing, 1028 .gpl_only = true, 1029 .ret_type = RET_INTEGER, 1030 .arg1_type = ARG_PTR_TO_CTX, 1031 }; 1032 1033 #ifdef CONFIG_X86_KERNEL_IBT 1034 static unsigned long get_entry_ip(unsigned long fentry_ip) 1035 { 1036 u32 instr; 1037 1038 /* Being extra safe in here in case entry ip is on the page-edge. */ 1039 if (get_kernel_nofault(instr, (u32 *) fentry_ip - 1)) 1040 return fentry_ip; 1041 if (is_endbr(instr)) 1042 fentry_ip -= ENDBR_INSN_SIZE; 1043 return fentry_ip; 1044 } 1045 #else 1046 #define get_entry_ip(fentry_ip) fentry_ip 1047 #endif 1048 1049 BPF_CALL_1(bpf_get_func_ip_kprobe, struct pt_regs *, regs) 1050 { 1051 struct kprobe *kp = kprobe_running(); 1052 1053 if (!kp || !(kp->flags & KPROBE_FLAG_ON_FUNC_ENTRY)) 1054 return 0; 1055 1056 return get_entry_ip((uintptr_t)kp->addr); 1057 } 1058 1059 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe = { 1060 .func = bpf_get_func_ip_kprobe, 1061 .gpl_only = true, 1062 .ret_type = RET_INTEGER, 1063 .arg1_type = ARG_PTR_TO_CTX, 1064 }; 1065 1066 BPF_CALL_1(bpf_get_func_ip_kprobe_multi, struct pt_regs *, regs) 1067 { 1068 return bpf_kprobe_multi_entry_ip(current->bpf_ctx); 1069 } 1070 1071 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe_multi = { 1072 .func = bpf_get_func_ip_kprobe_multi, 1073 .gpl_only = false, 1074 .ret_type = RET_INTEGER, 1075 .arg1_type = ARG_PTR_TO_CTX, 1076 }; 1077 1078 BPF_CALL_1(bpf_get_attach_cookie_kprobe_multi, struct pt_regs *, regs) 1079 { 1080 return bpf_kprobe_multi_cookie(current->bpf_ctx); 1081 } 1082 1083 static const struct bpf_func_proto bpf_get_attach_cookie_proto_kmulti = { 1084 .func = bpf_get_attach_cookie_kprobe_multi, 1085 .gpl_only = false, 1086 .ret_type = RET_INTEGER, 1087 .arg1_type = ARG_PTR_TO_CTX, 1088 }; 1089 1090 BPF_CALL_1(bpf_get_attach_cookie_trace, void *, ctx) 1091 { 1092 struct bpf_trace_run_ctx *run_ctx; 1093 1094 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); 1095 return run_ctx->bpf_cookie; 1096 } 1097 1098 static const struct bpf_func_proto bpf_get_attach_cookie_proto_trace = { 1099 .func = bpf_get_attach_cookie_trace, 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_pe, struct bpf_perf_event_data_kern *, ctx) 1106 { 1107 return ctx->event->bpf_cookie; 1108 } 1109 1110 static const struct bpf_func_proto bpf_get_attach_cookie_proto_pe = { 1111 .func = bpf_get_attach_cookie_pe, 1112 .gpl_only = false, 1113 .ret_type = RET_INTEGER, 1114 .arg1_type = ARG_PTR_TO_CTX, 1115 }; 1116 1117 BPF_CALL_1(bpf_get_attach_cookie_tracing, void *, ctx) 1118 { 1119 struct bpf_trace_run_ctx *run_ctx; 1120 1121 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); 1122 return run_ctx->bpf_cookie; 1123 } 1124 1125 static const struct bpf_func_proto bpf_get_attach_cookie_proto_tracing = { 1126 .func = bpf_get_attach_cookie_tracing, 1127 .gpl_only = false, 1128 .ret_type = RET_INTEGER, 1129 .arg1_type = ARG_PTR_TO_CTX, 1130 }; 1131 1132 BPF_CALL_3(bpf_get_branch_snapshot, void *, buf, u32, size, u64, flags) 1133 { 1134 #ifndef CONFIG_X86 1135 return -ENOENT; 1136 #else 1137 static const u32 br_entry_size = sizeof(struct perf_branch_entry); 1138 u32 entry_cnt = size / br_entry_size; 1139 1140 entry_cnt = static_call(perf_snapshot_branch_stack)(buf, entry_cnt); 1141 1142 if (unlikely(flags)) 1143 return -EINVAL; 1144 1145 if (!entry_cnt) 1146 return -ENOENT; 1147 1148 return entry_cnt * br_entry_size; 1149 #endif 1150 } 1151 1152 static const struct bpf_func_proto bpf_get_branch_snapshot_proto = { 1153 .func = bpf_get_branch_snapshot, 1154 .gpl_only = true, 1155 .ret_type = RET_INTEGER, 1156 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 1157 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 1158 }; 1159 1160 BPF_CALL_3(get_func_arg, void *, ctx, u32, n, u64 *, value) 1161 { 1162 /* This helper call is inlined by verifier. */ 1163 u64 nr_args = ((u64 *)ctx)[-1]; 1164 1165 if ((u64) n >= nr_args) 1166 return -EINVAL; 1167 *value = ((u64 *)ctx)[n]; 1168 return 0; 1169 } 1170 1171 static const struct bpf_func_proto bpf_get_func_arg_proto = { 1172 .func = get_func_arg, 1173 .ret_type = RET_INTEGER, 1174 .arg1_type = ARG_PTR_TO_CTX, 1175 .arg2_type = ARG_ANYTHING, 1176 .arg3_type = ARG_PTR_TO_LONG, 1177 }; 1178 1179 BPF_CALL_2(get_func_ret, void *, ctx, u64 *, value) 1180 { 1181 /* This helper call is inlined by verifier. */ 1182 u64 nr_args = ((u64 *)ctx)[-1]; 1183 1184 *value = ((u64 *)ctx)[nr_args]; 1185 return 0; 1186 } 1187 1188 static const struct bpf_func_proto bpf_get_func_ret_proto = { 1189 .func = get_func_ret, 1190 .ret_type = RET_INTEGER, 1191 .arg1_type = ARG_PTR_TO_CTX, 1192 .arg2_type = ARG_PTR_TO_LONG, 1193 }; 1194 1195 BPF_CALL_1(get_func_arg_cnt, void *, ctx) 1196 { 1197 /* This helper call is inlined by verifier. */ 1198 return ((u64 *)ctx)[-1]; 1199 } 1200 1201 static const struct bpf_func_proto bpf_get_func_arg_cnt_proto = { 1202 .func = get_func_arg_cnt, 1203 .ret_type = RET_INTEGER, 1204 .arg1_type = ARG_PTR_TO_CTX, 1205 }; 1206 1207 #ifdef CONFIG_KEYS 1208 __diag_push(); 1209 __diag_ignore_all("-Wmissing-prototypes", 1210 "kfuncs which will be used in BPF programs"); 1211 1212 /** 1213 * bpf_lookup_user_key - lookup a key by its serial 1214 * @serial: key handle serial number 1215 * @flags: lookup-specific flags 1216 * 1217 * Search a key with a given *serial* and the provided *flags*. 1218 * If found, increment the reference count of the key by one, and 1219 * return it in the bpf_key structure. 1220 * 1221 * The bpf_key structure must be passed to bpf_key_put() when done 1222 * with it, so that the key reference count is decremented and the 1223 * bpf_key structure is freed. 1224 * 1225 * Permission checks are deferred to the time the key is used by 1226 * one of the available key-specific kfuncs. 1227 * 1228 * Set *flags* with KEY_LOOKUP_CREATE, to attempt creating a requested 1229 * special keyring (e.g. session keyring), if it doesn't yet exist. 1230 * Set *flags* with KEY_LOOKUP_PARTIAL, to lookup a key without waiting 1231 * for the key construction, and to retrieve uninstantiated keys (keys 1232 * without data attached to them). 1233 * 1234 * Return: a bpf_key pointer with a valid key pointer if the key is found, a 1235 * NULL pointer otherwise. 1236 */ 1237 struct bpf_key *bpf_lookup_user_key(u32 serial, u64 flags) 1238 { 1239 key_ref_t key_ref; 1240 struct bpf_key *bkey; 1241 1242 if (flags & ~KEY_LOOKUP_ALL) 1243 return NULL; 1244 1245 /* 1246 * Permission check is deferred until the key is used, as the 1247 * intent of the caller is unknown here. 1248 */ 1249 key_ref = lookup_user_key(serial, flags, KEY_DEFER_PERM_CHECK); 1250 if (IS_ERR(key_ref)) 1251 return NULL; 1252 1253 bkey = kmalloc(sizeof(*bkey), GFP_KERNEL); 1254 if (!bkey) { 1255 key_put(key_ref_to_ptr(key_ref)); 1256 return NULL; 1257 } 1258 1259 bkey->key = key_ref_to_ptr(key_ref); 1260 bkey->has_ref = true; 1261 1262 return bkey; 1263 } 1264 1265 /** 1266 * bpf_lookup_system_key - lookup a key by a system-defined ID 1267 * @id: key ID 1268 * 1269 * Obtain a bpf_key structure with a key pointer set to the passed key ID. 1270 * The key pointer is marked as invalid, to prevent bpf_key_put() from 1271 * attempting to decrement the key reference count on that pointer. The key 1272 * pointer set in such way is currently understood only by 1273 * verify_pkcs7_signature(). 1274 * 1275 * Set *id* to one of the values defined in include/linux/verification.h: 1276 * 0 for the primary keyring (immutable keyring of system keys); 1277 * VERIFY_USE_SECONDARY_KEYRING for both the primary and secondary keyring 1278 * (where keys can be added only if they are vouched for by existing keys 1279 * in those keyrings); VERIFY_USE_PLATFORM_KEYRING for the platform 1280 * keyring (primarily used by the integrity subsystem to verify a kexec'ed 1281 * kerned image and, possibly, the initramfs signature). 1282 * 1283 * Return: a bpf_key pointer with an invalid key pointer set from the 1284 * pre-determined ID on success, a NULL pointer otherwise 1285 */ 1286 struct bpf_key *bpf_lookup_system_key(u64 id) 1287 { 1288 struct bpf_key *bkey; 1289 1290 if (system_keyring_id_check(id) < 0) 1291 return NULL; 1292 1293 bkey = kmalloc(sizeof(*bkey), GFP_ATOMIC); 1294 if (!bkey) 1295 return NULL; 1296 1297 bkey->key = (struct key *)(unsigned long)id; 1298 bkey->has_ref = false; 1299 1300 return bkey; 1301 } 1302 1303 /** 1304 * bpf_key_put - decrement key reference count if key is valid and free bpf_key 1305 * @bkey: bpf_key structure 1306 * 1307 * Decrement the reference count of the key inside *bkey*, if the pointer 1308 * is valid, and free *bkey*. 1309 */ 1310 void bpf_key_put(struct bpf_key *bkey) 1311 { 1312 if (bkey->has_ref) 1313 key_put(bkey->key); 1314 1315 kfree(bkey); 1316 } 1317 1318 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION 1319 /** 1320 * bpf_verify_pkcs7_signature - verify a PKCS#7 signature 1321 * @data_ptr: data to verify 1322 * @sig_ptr: signature of the data 1323 * @trusted_keyring: keyring with keys trusted for signature verification 1324 * 1325 * Verify the PKCS#7 signature *sig_ptr* against the supplied *data_ptr* 1326 * with keys in a keyring referenced by *trusted_keyring*. 1327 * 1328 * Return: 0 on success, a negative value on error. 1329 */ 1330 int bpf_verify_pkcs7_signature(struct bpf_dynptr_kern *data_ptr, 1331 struct bpf_dynptr_kern *sig_ptr, 1332 struct bpf_key *trusted_keyring) 1333 { 1334 int ret; 1335 1336 if (trusted_keyring->has_ref) { 1337 /* 1338 * Do the permission check deferred in bpf_lookup_user_key(). 1339 * See bpf_lookup_user_key() for more details. 1340 * 1341 * A call to key_task_permission() here would be redundant, as 1342 * it is already done by keyring_search() called by 1343 * find_asymmetric_key(). 1344 */ 1345 ret = key_validate(trusted_keyring->key); 1346 if (ret < 0) 1347 return ret; 1348 } 1349 1350 return verify_pkcs7_signature(data_ptr->data, 1351 bpf_dynptr_get_size(data_ptr), 1352 sig_ptr->data, 1353 bpf_dynptr_get_size(sig_ptr), 1354 trusted_keyring->key, 1355 VERIFYING_UNSPECIFIED_SIGNATURE, NULL, 1356 NULL); 1357 } 1358 #endif /* CONFIG_SYSTEM_DATA_VERIFICATION */ 1359 1360 __diag_pop(); 1361 1362 BTF_SET8_START(key_sig_kfunc_set) 1363 BTF_ID_FLAGS(func, bpf_lookup_user_key, KF_ACQUIRE | KF_RET_NULL | KF_SLEEPABLE) 1364 BTF_ID_FLAGS(func, bpf_lookup_system_key, KF_ACQUIRE | KF_RET_NULL) 1365 BTF_ID_FLAGS(func, bpf_key_put, KF_RELEASE) 1366 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION 1367 BTF_ID_FLAGS(func, bpf_verify_pkcs7_signature, KF_SLEEPABLE) 1368 #endif 1369 BTF_SET8_END(key_sig_kfunc_set) 1370 1371 static const struct btf_kfunc_id_set bpf_key_sig_kfunc_set = { 1372 .owner = THIS_MODULE, 1373 .set = &key_sig_kfunc_set, 1374 }; 1375 1376 static int __init bpf_key_sig_kfuncs_init(void) 1377 { 1378 return register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, 1379 &bpf_key_sig_kfunc_set); 1380 } 1381 1382 late_initcall(bpf_key_sig_kfuncs_init); 1383 #endif /* CONFIG_KEYS */ 1384 1385 static const struct bpf_func_proto * 1386 bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1387 { 1388 switch (func_id) { 1389 case BPF_FUNC_map_lookup_elem: 1390 return &bpf_map_lookup_elem_proto; 1391 case BPF_FUNC_map_update_elem: 1392 return &bpf_map_update_elem_proto; 1393 case BPF_FUNC_map_delete_elem: 1394 return &bpf_map_delete_elem_proto; 1395 case BPF_FUNC_map_push_elem: 1396 return &bpf_map_push_elem_proto; 1397 case BPF_FUNC_map_pop_elem: 1398 return &bpf_map_pop_elem_proto; 1399 case BPF_FUNC_map_peek_elem: 1400 return &bpf_map_peek_elem_proto; 1401 case BPF_FUNC_map_lookup_percpu_elem: 1402 return &bpf_map_lookup_percpu_elem_proto; 1403 case BPF_FUNC_ktime_get_ns: 1404 return &bpf_ktime_get_ns_proto; 1405 case BPF_FUNC_ktime_get_boot_ns: 1406 return &bpf_ktime_get_boot_ns_proto; 1407 case BPF_FUNC_tail_call: 1408 return &bpf_tail_call_proto; 1409 case BPF_FUNC_get_current_pid_tgid: 1410 return &bpf_get_current_pid_tgid_proto; 1411 case BPF_FUNC_get_current_task: 1412 return &bpf_get_current_task_proto; 1413 case BPF_FUNC_get_current_task_btf: 1414 return &bpf_get_current_task_btf_proto; 1415 case BPF_FUNC_task_pt_regs: 1416 return &bpf_task_pt_regs_proto; 1417 case BPF_FUNC_get_current_uid_gid: 1418 return &bpf_get_current_uid_gid_proto; 1419 case BPF_FUNC_get_current_comm: 1420 return &bpf_get_current_comm_proto; 1421 case BPF_FUNC_trace_printk: 1422 return bpf_get_trace_printk_proto(); 1423 case BPF_FUNC_get_smp_processor_id: 1424 return &bpf_get_smp_processor_id_proto; 1425 case BPF_FUNC_get_numa_node_id: 1426 return &bpf_get_numa_node_id_proto; 1427 case BPF_FUNC_perf_event_read: 1428 return &bpf_perf_event_read_proto; 1429 case BPF_FUNC_current_task_under_cgroup: 1430 return &bpf_current_task_under_cgroup_proto; 1431 case BPF_FUNC_get_prandom_u32: 1432 return &bpf_get_prandom_u32_proto; 1433 case BPF_FUNC_probe_write_user: 1434 return security_locked_down(LOCKDOWN_BPF_WRITE_USER) < 0 ? 1435 NULL : bpf_get_probe_write_proto(); 1436 case BPF_FUNC_probe_read_user: 1437 return &bpf_probe_read_user_proto; 1438 case BPF_FUNC_probe_read_kernel: 1439 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1440 NULL : &bpf_probe_read_kernel_proto; 1441 case BPF_FUNC_probe_read_user_str: 1442 return &bpf_probe_read_user_str_proto; 1443 case BPF_FUNC_probe_read_kernel_str: 1444 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1445 NULL : &bpf_probe_read_kernel_str_proto; 1446 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 1447 case BPF_FUNC_probe_read: 1448 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1449 NULL : &bpf_probe_read_compat_proto; 1450 case BPF_FUNC_probe_read_str: 1451 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1452 NULL : &bpf_probe_read_compat_str_proto; 1453 #endif 1454 #ifdef CONFIG_CGROUPS 1455 case BPF_FUNC_get_current_cgroup_id: 1456 return &bpf_get_current_cgroup_id_proto; 1457 case BPF_FUNC_get_current_ancestor_cgroup_id: 1458 return &bpf_get_current_ancestor_cgroup_id_proto; 1459 #endif 1460 case BPF_FUNC_send_signal: 1461 return &bpf_send_signal_proto; 1462 case BPF_FUNC_send_signal_thread: 1463 return &bpf_send_signal_thread_proto; 1464 case BPF_FUNC_perf_event_read_value: 1465 return &bpf_perf_event_read_value_proto; 1466 case BPF_FUNC_get_ns_current_pid_tgid: 1467 return &bpf_get_ns_current_pid_tgid_proto; 1468 case BPF_FUNC_ringbuf_output: 1469 return &bpf_ringbuf_output_proto; 1470 case BPF_FUNC_ringbuf_reserve: 1471 return &bpf_ringbuf_reserve_proto; 1472 case BPF_FUNC_ringbuf_submit: 1473 return &bpf_ringbuf_submit_proto; 1474 case BPF_FUNC_ringbuf_discard: 1475 return &bpf_ringbuf_discard_proto; 1476 case BPF_FUNC_ringbuf_query: 1477 return &bpf_ringbuf_query_proto; 1478 case BPF_FUNC_jiffies64: 1479 return &bpf_jiffies64_proto; 1480 case BPF_FUNC_get_task_stack: 1481 return &bpf_get_task_stack_proto; 1482 case BPF_FUNC_copy_from_user: 1483 return prog->aux->sleepable ? &bpf_copy_from_user_proto : NULL; 1484 case BPF_FUNC_copy_from_user_task: 1485 return prog->aux->sleepable ? &bpf_copy_from_user_task_proto : NULL; 1486 case BPF_FUNC_snprintf_btf: 1487 return &bpf_snprintf_btf_proto; 1488 case BPF_FUNC_per_cpu_ptr: 1489 return &bpf_per_cpu_ptr_proto; 1490 case BPF_FUNC_this_cpu_ptr: 1491 return &bpf_this_cpu_ptr_proto; 1492 case BPF_FUNC_task_storage_get: 1493 return &bpf_task_storage_get_proto; 1494 case BPF_FUNC_task_storage_delete: 1495 return &bpf_task_storage_delete_proto; 1496 case BPF_FUNC_for_each_map_elem: 1497 return &bpf_for_each_map_elem_proto; 1498 case BPF_FUNC_snprintf: 1499 return &bpf_snprintf_proto; 1500 case BPF_FUNC_get_func_ip: 1501 return &bpf_get_func_ip_proto_tracing; 1502 case BPF_FUNC_get_branch_snapshot: 1503 return &bpf_get_branch_snapshot_proto; 1504 case BPF_FUNC_find_vma: 1505 return &bpf_find_vma_proto; 1506 case BPF_FUNC_trace_vprintk: 1507 return bpf_get_trace_vprintk_proto(); 1508 default: 1509 return bpf_base_func_proto(func_id); 1510 } 1511 } 1512 1513 static const struct bpf_func_proto * 1514 kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1515 { 1516 switch (func_id) { 1517 case BPF_FUNC_perf_event_output: 1518 return &bpf_perf_event_output_proto; 1519 case BPF_FUNC_get_stackid: 1520 return &bpf_get_stackid_proto; 1521 case BPF_FUNC_get_stack: 1522 return &bpf_get_stack_proto; 1523 #ifdef CONFIG_BPF_KPROBE_OVERRIDE 1524 case BPF_FUNC_override_return: 1525 return &bpf_override_return_proto; 1526 #endif 1527 case BPF_FUNC_get_func_ip: 1528 return prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI ? 1529 &bpf_get_func_ip_proto_kprobe_multi : 1530 &bpf_get_func_ip_proto_kprobe; 1531 case BPF_FUNC_get_attach_cookie: 1532 return prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI ? 1533 &bpf_get_attach_cookie_proto_kmulti : 1534 &bpf_get_attach_cookie_proto_trace; 1535 default: 1536 return bpf_tracing_func_proto(func_id, prog); 1537 } 1538 } 1539 1540 /* bpf+kprobe programs can access fields of 'struct pt_regs' */ 1541 static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type, 1542 const struct bpf_prog *prog, 1543 struct bpf_insn_access_aux *info) 1544 { 1545 if (off < 0 || off >= sizeof(struct pt_regs)) 1546 return false; 1547 if (type != BPF_READ) 1548 return false; 1549 if (off % size != 0) 1550 return false; 1551 /* 1552 * Assertion for 32 bit to make sure last 8 byte access 1553 * (BPF_DW) to the last 4 byte member is disallowed. 1554 */ 1555 if (off + size > sizeof(struct pt_regs)) 1556 return false; 1557 1558 return true; 1559 } 1560 1561 const struct bpf_verifier_ops kprobe_verifier_ops = { 1562 .get_func_proto = kprobe_prog_func_proto, 1563 .is_valid_access = kprobe_prog_is_valid_access, 1564 }; 1565 1566 const struct bpf_prog_ops kprobe_prog_ops = { 1567 }; 1568 1569 BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map, 1570 u64, flags, void *, data, u64, size) 1571 { 1572 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1573 1574 /* 1575 * r1 points to perf tracepoint buffer where first 8 bytes are hidden 1576 * from bpf program and contain a pointer to 'struct pt_regs'. Fetch it 1577 * from there and call the same bpf_perf_event_output() helper inline. 1578 */ 1579 return ____bpf_perf_event_output(regs, map, flags, data, size); 1580 } 1581 1582 static const struct bpf_func_proto bpf_perf_event_output_proto_tp = { 1583 .func = bpf_perf_event_output_tp, 1584 .gpl_only = true, 1585 .ret_type = RET_INTEGER, 1586 .arg1_type = ARG_PTR_TO_CTX, 1587 .arg2_type = ARG_CONST_MAP_PTR, 1588 .arg3_type = ARG_ANYTHING, 1589 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1590 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 1591 }; 1592 1593 BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map, 1594 u64, flags) 1595 { 1596 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1597 1598 /* 1599 * Same comment as in bpf_perf_event_output_tp(), only that this time 1600 * the other helper's function body cannot be inlined due to being 1601 * external, thus we need to call raw helper function. 1602 */ 1603 return bpf_get_stackid((unsigned long) regs, (unsigned long) map, 1604 flags, 0, 0); 1605 } 1606 1607 static const struct bpf_func_proto bpf_get_stackid_proto_tp = { 1608 .func = bpf_get_stackid_tp, 1609 .gpl_only = true, 1610 .ret_type = RET_INTEGER, 1611 .arg1_type = ARG_PTR_TO_CTX, 1612 .arg2_type = ARG_CONST_MAP_PTR, 1613 .arg3_type = ARG_ANYTHING, 1614 }; 1615 1616 BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size, 1617 u64, flags) 1618 { 1619 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1620 1621 return bpf_get_stack((unsigned long) regs, (unsigned long) buf, 1622 (unsigned long) size, flags, 0); 1623 } 1624 1625 static const struct bpf_func_proto bpf_get_stack_proto_tp = { 1626 .func = bpf_get_stack_tp, 1627 .gpl_only = true, 1628 .ret_type = RET_INTEGER, 1629 .arg1_type = ARG_PTR_TO_CTX, 1630 .arg2_type = ARG_PTR_TO_UNINIT_MEM, 1631 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1632 .arg4_type = ARG_ANYTHING, 1633 }; 1634 1635 static const struct bpf_func_proto * 1636 tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1637 { 1638 switch (func_id) { 1639 case BPF_FUNC_perf_event_output: 1640 return &bpf_perf_event_output_proto_tp; 1641 case BPF_FUNC_get_stackid: 1642 return &bpf_get_stackid_proto_tp; 1643 case BPF_FUNC_get_stack: 1644 return &bpf_get_stack_proto_tp; 1645 case BPF_FUNC_get_attach_cookie: 1646 return &bpf_get_attach_cookie_proto_trace; 1647 default: 1648 return bpf_tracing_func_proto(func_id, prog); 1649 } 1650 } 1651 1652 static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type, 1653 const struct bpf_prog *prog, 1654 struct bpf_insn_access_aux *info) 1655 { 1656 if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE) 1657 return false; 1658 if (type != BPF_READ) 1659 return false; 1660 if (off % size != 0) 1661 return false; 1662 1663 BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(__u64)); 1664 return true; 1665 } 1666 1667 const struct bpf_verifier_ops tracepoint_verifier_ops = { 1668 .get_func_proto = tp_prog_func_proto, 1669 .is_valid_access = tp_prog_is_valid_access, 1670 }; 1671 1672 const struct bpf_prog_ops tracepoint_prog_ops = { 1673 }; 1674 1675 BPF_CALL_3(bpf_perf_prog_read_value, struct bpf_perf_event_data_kern *, ctx, 1676 struct bpf_perf_event_value *, buf, u32, size) 1677 { 1678 int err = -EINVAL; 1679 1680 if (unlikely(size != sizeof(struct bpf_perf_event_value))) 1681 goto clear; 1682 err = perf_event_read_local(ctx->event, &buf->counter, &buf->enabled, 1683 &buf->running); 1684 if (unlikely(err)) 1685 goto clear; 1686 return 0; 1687 clear: 1688 memset(buf, 0, size); 1689 return err; 1690 } 1691 1692 static const struct bpf_func_proto bpf_perf_prog_read_value_proto = { 1693 .func = bpf_perf_prog_read_value, 1694 .gpl_only = true, 1695 .ret_type = RET_INTEGER, 1696 .arg1_type = ARG_PTR_TO_CTX, 1697 .arg2_type = ARG_PTR_TO_UNINIT_MEM, 1698 .arg3_type = ARG_CONST_SIZE, 1699 }; 1700 1701 BPF_CALL_4(bpf_read_branch_records, struct bpf_perf_event_data_kern *, ctx, 1702 void *, buf, u32, size, u64, flags) 1703 { 1704 static const u32 br_entry_size = sizeof(struct perf_branch_entry); 1705 struct perf_branch_stack *br_stack = ctx->data->br_stack; 1706 u32 to_copy; 1707 1708 if (unlikely(flags & ~BPF_F_GET_BRANCH_RECORDS_SIZE)) 1709 return -EINVAL; 1710 1711 if (unlikely(!(ctx->data->sample_flags & PERF_SAMPLE_BRANCH_STACK))) 1712 return -ENOENT; 1713 1714 if (unlikely(!br_stack)) 1715 return -ENOENT; 1716 1717 if (flags & BPF_F_GET_BRANCH_RECORDS_SIZE) 1718 return br_stack->nr * br_entry_size; 1719 1720 if (!buf || (size % br_entry_size != 0)) 1721 return -EINVAL; 1722 1723 to_copy = min_t(u32, br_stack->nr * br_entry_size, size); 1724 memcpy(buf, br_stack->entries, to_copy); 1725 1726 return to_copy; 1727 } 1728 1729 static const struct bpf_func_proto bpf_read_branch_records_proto = { 1730 .func = bpf_read_branch_records, 1731 .gpl_only = true, 1732 .ret_type = RET_INTEGER, 1733 .arg1_type = ARG_PTR_TO_CTX, 1734 .arg2_type = ARG_PTR_TO_MEM_OR_NULL, 1735 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1736 .arg4_type = ARG_ANYTHING, 1737 }; 1738 1739 static const struct bpf_func_proto * 1740 pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1741 { 1742 switch (func_id) { 1743 case BPF_FUNC_perf_event_output: 1744 return &bpf_perf_event_output_proto_tp; 1745 case BPF_FUNC_get_stackid: 1746 return &bpf_get_stackid_proto_pe; 1747 case BPF_FUNC_get_stack: 1748 return &bpf_get_stack_proto_pe; 1749 case BPF_FUNC_perf_prog_read_value: 1750 return &bpf_perf_prog_read_value_proto; 1751 case BPF_FUNC_read_branch_records: 1752 return &bpf_read_branch_records_proto; 1753 case BPF_FUNC_get_attach_cookie: 1754 return &bpf_get_attach_cookie_proto_pe; 1755 default: 1756 return bpf_tracing_func_proto(func_id, prog); 1757 } 1758 } 1759 1760 /* 1761 * bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp 1762 * to avoid potential recursive reuse issue when/if tracepoints are added 1763 * inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack. 1764 * 1765 * Since raw tracepoints run despite bpf_prog_active, support concurrent usage 1766 * in normal, irq, and nmi context. 1767 */ 1768 struct bpf_raw_tp_regs { 1769 struct pt_regs regs[3]; 1770 }; 1771 static DEFINE_PER_CPU(struct bpf_raw_tp_regs, bpf_raw_tp_regs); 1772 static DEFINE_PER_CPU(int, bpf_raw_tp_nest_level); 1773 static struct pt_regs *get_bpf_raw_tp_regs(void) 1774 { 1775 struct bpf_raw_tp_regs *tp_regs = this_cpu_ptr(&bpf_raw_tp_regs); 1776 int nest_level = this_cpu_inc_return(bpf_raw_tp_nest_level); 1777 1778 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(tp_regs->regs))) { 1779 this_cpu_dec(bpf_raw_tp_nest_level); 1780 return ERR_PTR(-EBUSY); 1781 } 1782 1783 return &tp_regs->regs[nest_level - 1]; 1784 } 1785 1786 static void put_bpf_raw_tp_regs(void) 1787 { 1788 this_cpu_dec(bpf_raw_tp_nest_level); 1789 } 1790 1791 BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args, 1792 struct bpf_map *, map, u64, flags, void *, data, u64, size) 1793 { 1794 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1795 int ret; 1796 1797 if (IS_ERR(regs)) 1798 return PTR_ERR(regs); 1799 1800 perf_fetch_caller_regs(regs); 1801 ret = ____bpf_perf_event_output(regs, map, flags, data, size); 1802 1803 put_bpf_raw_tp_regs(); 1804 return ret; 1805 } 1806 1807 static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = { 1808 .func = bpf_perf_event_output_raw_tp, 1809 .gpl_only = true, 1810 .ret_type = RET_INTEGER, 1811 .arg1_type = ARG_PTR_TO_CTX, 1812 .arg2_type = ARG_CONST_MAP_PTR, 1813 .arg3_type = ARG_ANYTHING, 1814 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1815 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 1816 }; 1817 1818 extern const struct bpf_func_proto bpf_skb_output_proto; 1819 extern const struct bpf_func_proto bpf_xdp_output_proto; 1820 extern const struct bpf_func_proto bpf_xdp_get_buff_len_trace_proto; 1821 1822 BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args, 1823 struct bpf_map *, map, u64, flags) 1824 { 1825 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1826 int ret; 1827 1828 if (IS_ERR(regs)) 1829 return PTR_ERR(regs); 1830 1831 perf_fetch_caller_regs(regs); 1832 /* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */ 1833 ret = bpf_get_stackid((unsigned long) regs, (unsigned long) map, 1834 flags, 0, 0); 1835 put_bpf_raw_tp_regs(); 1836 return ret; 1837 } 1838 1839 static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = { 1840 .func = bpf_get_stackid_raw_tp, 1841 .gpl_only = true, 1842 .ret_type = RET_INTEGER, 1843 .arg1_type = ARG_PTR_TO_CTX, 1844 .arg2_type = ARG_CONST_MAP_PTR, 1845 .arg3_type = ARG_ANYTHING, 1846 }; 1847 1848 BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args, 1849 void *, buf, u32, size, u64, flags) 1850 { 1851 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1852 int ret; 1853 1854 if (IS_ERR(regs)) 1855 return PTR_ERR(regs); 1856 1857 perf_fetch_caller_regs(regs); 1858 ret = bpf_get_stack((unsigned long) regs, (unsigned long) buf, 1859 (unsigned long) size, flags, 0); 1860 put_bpf_raw_tp_regs(); 1861 return ret; 1862 } 1863 1864 static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = { 1865 .func = bpf_get_stack_raw_tp, 1866 .gpl_only = true, 1867 .ret_type = RET_INTEGER, 1868 .arg1_type = ARG_PTR_TO_CTX, 1869 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1870 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1871 .arg4_type = ARG_ANYTHING, 1872 }; 1873 1874 static const struct bpf_func_proto * 1875 raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1876 { 1877 switch (func_id) { 1878 case BPF_FUNC_perf_event_output: 1879 return &bpf_perf_event_output_proto_raw_tp; 1880 case BPF_FUNC_get_stackid: 1881 return &bpf_get_stackid_proto_raw_tp; 1882 case BPF_FUNC_get_stack: 1883 return &bpf_get_stack_proto_raw_tp; 1884 default: 1885 return bpf_tracing_func_proto(func_id, prog); 1886 } 1887 } 1888 1889 const struct bpf_func_proto * 1890 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1891 { 1892 const struct bpf_func_proto *fn; 1893 1894 switch (func_id) { 1895 #ifdef CONFIG_NET 1896 case BPF_FUNC_skb_output: 1897 return &bpf_skb_output_proto; 1898 case BPF_FUNC_xdp_output: 1899 return &bpf_xdp_output_proto; 1900 case BPF_FUNC_skc_to_tcp6_sock: 1901 return &bpf_skc_to_tcp6_sock_proto; 1902 case BPF_FUNC_skc_to_tcp_sock: 1903 return &bpf_skc_to_tcp_sock_proto; 1904 case BPF_FUNC_skc_to_tcp_timewait_sock: 1905 return &bpf_skc_to_tcp_timewait_sock_proto; 1906 case BPF_FUNC_skc_to_tcp_request_sock: 1907 return &bpf_skc_to_tcp_request_sock_proto; 1908 case BPF_FUNC_skc_to_udp6_sock: 1909 return &bpf_skc_to_udp6_sock_proto; 1910 case BPF_FUNC_skc_to_unix_sock: 1911 return &bpf_skc_to_unix_sock_proto; 1912 case BPF_FUNC_skc_to_mptcp_sock: 1913 return &bpf_skc_to_mptcp_sock_proto; 1914 case BPF_FUNC_sk_storage_get: 1915 return &bpf_sk_storage_get_tracing_proto; 1916 case BPF_FUNC_sk_storage_delete: 1917 return &bpf_sk_storage_delete_tracing_proto; 1918 case BPF_FUNC_sock_from_file: 1919 return &bpf_sock_from_file_proto; 1920 case BPF_FUNC_get_socket_cookie: 1921 return &bpf_get_socket_ptr_cookie_proto; 1922 case BPF_FUNC_xdp_get_buff_len: 1923 return &bpf_xdp_get_buff_len_trace_proto; 1924 #endif 1925 case BPF_FUNC_seq_printf: 1926 return prog->expected_attach_type == BPF_TRACE_ITER ? 1927 &bpf_seq_printf_proto : 1928 NULL; 1929 case BPF_FUNC_seq_write: 1930 return prog->expected_attach_type == BPF_TRACE_ITER ? 1931 &bpf_seq_write_proto : 1932 NULL; 1933 case BPF_FUNC_seq_printf_btf: 1934 return prog->expected_attach_type == BPF_TRACE_ITER ? 1935 &bpf_seq_printf_btf_proto : 1936 NULL; 1937 case BPF_FUNC_d_path: 1938 return &bpf_d_path_proto; 1939 case BPF_FUNC_get_func_arg: 1940 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_proto : NULL; 1941 case BPF_FUNC_get_func_ret: 1942 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_ret_proto : NULL; 1943 case BPF_FUNC_get_func_arg_cnt: 1944 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_cnt_proto : NULL; 1945 case BPF_FUNC_get_attach_cookie: 1946 return bpf_prog_has_trampoline(prog) ? &bpf_get_attach_cookie_proto_tracing : NULL; 1947 default: 1948 fn = raw_tp_prog_func_proto(func_id, prog); 1949 if (!fn && prog->expected_attach_type == BPF_TRACE_ITER) 1950 fn = bpf_iter_get_func_proto(func_id, prog); 1951 return fn; 1952 } 1953 } 1954 1955 static bool raw_tp_prog_is_valid_access(int off, int size, 1956 enum bpf_access_type type, 1957 const struct bpf_prog *prog, 1958 struct bpf_insn_access_aux *info) 1959 { 1960 return bpf_tracing_ctx_access(off, size, type); 1961 } 1962 1963 static bool tracing_prog_is_valid_access(int off, int size, 1964 enum bpf_access_type type, 1965 const struct bpf_prog *prog, 1966 struct bpf_insn_access_aux *info) 1967 { 1968 return bpf_tracing_btf_ctx_access(off, size, type, prog, info); 1969 } 1970 1971 int __weak bpf_prog_test_run_tracing(struct bpf_prog *prog, 1972 const union bpf_attr *kattr, 1973 union bpf_attr __user *uattr) 1974 { 1975 return -ENOTSUPP; 1976 } 1977 1978 const struct bpf_verifier_ops raw_tracepoint_verifier_ops = { 1979 .get_func_proto = raw_tp_prog_func_proto, 1980 .is_valid_access = raw_tp_prog_is_valid_access, 1981 }; 1982 1983 const struct bpf_prog_ops raw_tracepoint_prog_ops = { 1984 #ifdef CONFIG_NET 1985 .test_run = bpf_prog_test_run_raw_tp, 1986 #endif 1987 }; 1988 1989 const struct bpf_verifier_ops tracing_verifier_ops = { 1990 .get_func_proto = tracing_prog_func_proto, 1991 .is_valid_access = tracing_prog_is_valid_access, 1992 }; 1993 1994 const struct bpf_prog_ops tracing_prog_ops = { 1995 .test_run = bpf_prog_test_run_tracing, 1996 }; 1997 1998 static bool raw_tp_writable_prog_is_valid_access(int off, int size, 1999 enum bpf_access_type type, 2000 const struct bpf_prog *prog, 2001 struct bpf_insn_access_aux *info) 2002 { 2003 if (off == 0) { 2004 if (size != sizeof(u64) || type != BPF_READ) 2005 return false; 2006 info->reg_type = PTR_TO_TP_BUFFER; 2007 } 2008 return raw_tp_prog_is_valid_access(off, size, type, prog, info); 2009 } 2010 2011 const struct bpf_verifier_ops raw_tracepoint_writable_verifier_ops = { 2012 .get_func_proto = raw_tp_prog_func_proto, 2013 .is_valid_access = raw_tp_writable_prog_is_valid_access, 2014 }; 2015 2016 const struct bpf_prog_ops raw_tracepoint_writable_prog_ops = { 2017 }; 2018 2019 static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type, 2020 const struct bpf_prog *prog, 2021 struct bpf_insn_access_aux *info) 2022 { 2023 const int size_u64 = sizeof(u64); 2024 2025 if (off < 0 || off >= sizeof(struct bpf_perf_event_data)) 2026 return false; 2027 if (type != BPF_READ) 2028 return false; 2029 if (off % size != 0) { 2030 if (sizeof(unsigned long) != 4) 2031 return false; 2032 if (size != 8) 2033 return false; 2034 if (off % size != 4) 2035 return false; 2036 } 2037 2038 switch (off) { 2039 case bpf_ctx_range(struct bpf_perf_event_data, sample_period): 2040 bpf_ctx_record_field_size(info, size_u64); 2041 if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) 2042 return false; 2043 break; 2044 case bpf_ctx_range(struct bpf_perf_event_data, addr): 2045 bpf_ctx_record_field_size(info, size_u64); 2046 if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) 2047 return false; 2048 break; 2049 default: 2050 if (size != sizeof(long)) 2051 return false; 2052 } 2053 2054 return true; 2055 } 2056 2057 static u32 pe_prog_convert_ctx_access(enum bpf_access_type type, 2058 const struct bpf_insn *si, 2059 struct bpf_insn *insn_buf, 2060 struct bpf_prog *prog, u32 *target_size) 2061 { 2062 struct bpf_insn *insn = insn_buf; 2063 2064 switch (si->off) { 2065 case offsetof(struct bpf_perf_event_data, sample_period): 2066 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 2067 data), si->dst_reg, si->src_reg, 2068 offsetof(struct bpf_perf_event_data_kern, data)); 2069 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, 2070 bpf_target_off(struct perf_sample_data, period, 8, 2071 target_size)); 2072 break; 2073 case offsetof(struct bpf_perf_event_data, addr): 2074 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 2075 data), si->dst_reg, si->src_reg, 2076 offsetof(struct bpf_perf_event_data_kern, data)); 2077 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, 2078 bpf_target_off(struct perf_sample_data, addr, 8, 2079 target_size)); 2080 break; 2081 default: 2082 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 2083 regs), si->dst_reg, si->src_reg, 2084 offsetof(struct bpf_perf_event_data_kern, regs)); 2085 *insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg, 2086 si->off); 2087 break; 2088 } 2089 2090 return insn - insn_buf; 2091 } 2092 2093 const struct bpf_verifier_ops perf_event_verifier_ops = { 2094 .get_func_proto = pe_prog_func_proto, 2095 .is_valid_access = pe_prog_is_valid_access, 2096 .convert_ctx_access = pe_prog_convert_ctx_access, 2097 }; 2098 2099 const struct bpf_prog_ops perf_event_prog_ops = { 2100 }; 2101 2102 static DEFINE_MUTEX(bpf_event_mutex); 2103 2104 #define BPF_TRACE_MAX_PROGS 64 2105 2106 int perf_event_attach_bpf_prog(struct perf_event *event, 2107 struct bpf_prog *prog, 2108 u64 bpf_cookie) 2109 { 2110 struct bpf_prog_array *old_array; 2111 struct bpf_prog_array *new_array; 2112 int ret = -EEXIST; 2113 2114 /* 2115 * Kprobe override only works if they are on the function entry, 2116 * and only if they are on the opt-in list. 2117 */ 2118 if (prog->kprobe_override && 2119 (!trace_kprobe_on_func_entry(event->tp_event) || 2120 !trace_kprobe_error_injectable(event->tp_event))) 2121 return -EINVAL; 2122 2123 mutex_lock(&bpf_event_mutex); 2124 2125 if (event->prog) 2126 goto unlock; 2127 2128 old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); 2129 if (old_array && 2130 bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) { 2131 ret = -E2BIG; 2132 goto unlock; 2133 } 2134 2135 ret = bpf_prog_array_copy(old_array, NULL, prog, bpf_cookie, &new_array); 2136 if (ret < 0) 2137 goto unlock; 2138 2139 /* set the new array to event->tp_event and set event->prog */ 2140 event->prog = prog; 2141 event->bpf_cookie = bpf_cookie; 2142 rcu_assign_pointer(event->tp_event->prog_array, new_array); 2143 bpf_prog_array_free_sleepable(old_array); 2144 2145 unlock: 2146 mutex_unlock(&bpf_event_mutex); 2147 return ret; 2148 } 2149 2150 void perf_event_detach_bpf_prog(struct perf_event *event) 2151 { 2152 struct bpf_prog_array *old_array; 2153 struct bpf_prog_array *new_array; 2154 int ret; 2155 2156 mutex_lock(&bpf_event_mutex); 2157 2158 if (!event->prog) 2159 goto unlock; 2160 2161 old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); 2162 ret = bpf_prog_array_copy(old_array, event->prog, NULL, 0, &new_array); 2163 if (ret == -ENOENT) 2164 goto unlock; 2165 if (ret < 0) { 2166 bpf_prog_array_delete_safe(old_array, event->prog); 2167 } else { 2168 rcu_assign_pointer(event->tp_event->prog_array, new_array); 2169 bpf_prog_array_free_sleepable(old_array); 2170 } 2171 2172 bpf_prog_put(event->prog); 2173 event->prog = NULL; 2174 2175 unlock: 2176 mutex_unlock(&bpf_event_mutex); 2177 } 2178 2179 int perf_event_query_prog_array(struct perf_event *event, void __user *info) 2180 { 2181 struct perf_event_query_bpf __user *uquery = info; 2182 struct perf_event_query_bpf query = {}; 2183 struct bpf_prog_array *progs; 2184 u32 *ids, prog_cnt, ids_len; 2185 int ret; 2186 2187 if (!perfmon_capable()) 2188 return -EPERM; 2189 if (event->attr.type != PERF_TYPE_TRACEPOINT) 2190 return -EINVAL; 2191 if (copy_from_user(&query, uquery, sizeof(query))) 2192 return -EFAULT; 2193 2194 ids_len = query.ids_len; 2195 if (ids_len > BPF_TRACE_MAX_PROGS) 2196 return -E2BIG; 2197 ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN); 2198 if (!ids) 2199 return -ENOMEM; 2200 /* 2201 * The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which 2202 * is required when user only wants to check for uquery->prog_cnt. 2203 * There is no need to check for it since the case is handled 2204 * gracefully in bpf_prog_array_copy_info. 2205 */ 2206 2207 mutex_lock(&bpf_event_mutex); 2208 progs = bpf_event_rcu_dereference(event->tp_event->prog_array); 2209 ret = bpf_prog_array_copy_info(progs, ids, ids_len, &prog_cnt); 2210 mutex_unlock(&bpf_event_mutex); 2211 2212 if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) || 2213 copy_to_user(uquery->ids, ids, ids_len * sizeof(u32))) 2214 ret = -EFAULT; 2215 2216 kfree(ids); 2217 return ret; 2218 } 2219 2220 extern struct bpf_raw_event_map __start__bpf_raw_tp[]; 2221 extern struct bpf_raw_event_map __stop__bpf_raw_tp[]; 2222 2223 struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name) 2224 { 2225 struct bpf_raw_event_map *btp = __start__bpf_raw_tp; 2226 2227 for (; btp < __stop__bpf_raw_tp; btp++) { 2228 if (!strcmp(btp->tp->name, name)) 2229 return btp; 2230 } 2231 2232 return bpf_get_raw_tracepoint_module(name); 2233 } 2234 2235 void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp) 2236 { 2237 struct module *mod; 2238 2239 preempt_disable(); 2240 mod = __module_address((unsigned long)btp); 2241 module_put(mod); 2242 preempt_enable(); 2243 } 2244 2245 static __always_inline 2246 void __bpf_trace_run(struct bpf_prog *prog, u64 *args) 2247 { 2248 cant_sleep(); 2249 if (unlikely(this_cpu_inc_return(*(prog->active)) != 1)) { 2250 bpf_prog_inc_misses_counter(prog); 2251 goto out; 2252 } 2253 rcu_read_lock(); 2254 (void) bpf_prog_run(prog, args); 2255 rcu_read_unlock(); 2256 out: 2257 this_cpu_dec(*(prog->active)); 2258 } 2259 2260 #define UNPACK(...) __VA_ARGS__ 2261 #define REPEAT_1(FN, DL, X, ...) FN(X) 2262 #define REPEAT_2(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__) 2263 #define REPEAT_3(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_2(FN, DL, __VA_ARGS__) 2264 #define REPEAT_4(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_3(FN, DL, __VA_ARGS__) 2265 #define REPEAT_5(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_4(FN, DL, __VA_ARGS__) 2266 #define REPEAT_6(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_5(FN, DL, __VA_ARGS__) 2267 #define REPEAT_7(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_6(FN, DL, __VA_ARGS__) 2268 #define REPEAT_8(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_7(FN, DL, __VA_ARGS__) 2269 #define REPEAT_9(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_8(FN, DL, __VA_ARGS__) 2270 #define REPEAT_10(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_9(FN, DL, __VA_ARGS__) 2271 #define REPEAT_11(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_10(FN, DL, __VA_ARGS__) 2272 #define REPEAT_12(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_11(FN, DL, __VA_ARGS__) 2273 #define REPEAT(X, FN, DL, ...) REPEAT_##X(FN, DL, __VA_ARGS__) 2274 2275 #define SARG(X) u64 arg##X 2276 #define COPY(X) args[X] = arg##X 2277 2278 #define __DL_COM (,) 2279 #define __DL_SEM (;) 2280 2281 #define __SEQ_0_11 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 2282 2283 #define BPF_TRACE_DEFN_x(x) \ 2284 void bpf_trace_run##x(struct bpf_prog *prog, \ 2285 REPEAT(x, SARG, __DL_COM, __SEQ_0_11)) \ 2286 { \ 2287 u64 args[x]; \ 2288 REPEAT(x, COPY, __DL_SEM, __SEQ_0_11); \ 2289 __bpf_trace_run(prog, args); \ 2290 } \ 2291 EXPORT_SYMBOL_GPL(bpf_trace_run##x) 2292 BPF_TRACE_DEFN_x(1); 2293 BPF_TRACE_DEFN_x(2); 2294 BPF_TRACE_DEFN_x(3); 2295 BPF_TRACE_DEFN_x(4); 2296 BPF_TRACE_DEFN_x(5); 2297 BPF_TRACE_DEFN_x(6); 2298 BPF_TRACE_DEFN_x(7); 2299 BPF_TRACE_DEFN_x(8); 2300 BPF_TRACE_DEFN_x(9); 2301 BPF_TRACE_DEFN_x(10); 2302 BPF_TRACE_DEFN_x(11); 2303 BPF_TRACE_DEFN_x(12); 2304 2305 static int __bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog) 2306 { 2307 struct tracepoint *tp = btp->tp; 2308 2309 /* 2310 * check that program doesn't access arguments beyond what's 2311 * available in this tracepoint 2312 */ 2313 if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64)) 2314 return -EINVAL; 2315 2316 if (prog->aux->max_tp_access > btp->writable_size) 2317 return -EINVAL; 2318 2319 return tracepoint_probe_register_may_exist(tp, (void *)btp->bpf_func, 2320 prog); 2321 } 2322 2323 int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog) 2324 { 2325 return __bpf_probe_register(btp, prog); 2326 } 2327 2328 int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_prog *prog) 2329 { 2330 return tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, prog); 2331 } 2332 2333 int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id, 2334 u32 *fd_type, const char **buf, 2335 u64 *probe_offset, u64 *probe_addr) 2336 { 2337 bool is_tracepoint, is_syscall_tp; 2338 struct bpf_prog *prog; 2339 int flags, err = 0; 2340 2341 prog = event->prog; 2342 if (!prog) 2343 return -ENOENT; 2344 2345 /* not supporting BPF_PROG_TYPE_PERF_EVENT yet */ 2346 if (prog->type == BPF_PROG_TYPE_PERF_EVENT) 2347 return -EOPNOTSUPP; 2348 2349 *prog_id = prog->aux->id; 2350 flags = event->tp_event->flags; 2351 is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT; 2352 is_syscall_tp = is_syscall_trace_event(event->tp_event); 2353 2354 if (is_tracepoint || is_syscall_tp) { 2355 *buf = is_tracepoint ? event->tp_event->tp->name 2356 : event->tp_event->name; 2357 *fd_type = BPF_FD_TYPE_TRACEPOINT; 2358 *probe_offset = 0x0; 2359 *probe_addr = 0x0; 2360 } else { 2361 /* kprobe/uprobe */ 2362 err = -EOPNOTSUPP; 2363 #ifdef CONFIG_KPROBE_EVENTS 2364 if (flags & TRACE_EVENT_FL_KPROBE) 2365 err = bpf_get_kprobe_info(event, fd_type, buf, 2366 probe_offset, probe_addr, 2367 event->attr.type == PERF_TYPE_TRACEPOINT); 2368 #endif 2369 #ifdef CONFIG_UPROBE_EVENTS 2370 if (flags & TRACE_EVENT_FL_UPROBE) 2371 err = bpf_get_uprobe_info(event, fd_type, buf, 2372 probe_offset, 2373 event->attr.type == PERF_TYPE_TRACEPOINT); 2374 #endif 2375 } 2376 2377 return err; 2378 } 2379 2380 static int __init send_signal_irq_work_init(void) 2381 { 2382 int cpu; 2383 struct send_signal_irq_work *work; 2384 2385 for_each_possible_cpu(cpu) { 2386 work = per_cpu_ptr(&send_signal_work, cpu); 2387 init_irq_work(&work->irq_work, do_bpf_send_signal); 2388 } 2389 return 0; 2390 } 2391 2392 subsys_initcall(send_signal_irq_work_init); 2393 2394 #ifdef CONFIG_MODULES 2395 static int bpf_event_notify(struct notifier_block *nb, unsigned long op, 2396 void *module) 2397 { 2398 struct bpf_trace_module *btm, *tmp; 2399 struct module *mod = module; 2400 int ret = 0; 2401 2402 if (mod->num_bpf_raw_events == 0 || 2403 (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING)) 2404 goto out; 2405 2406 mutex_lock(&bpf_module_mutex); 2407 2408 switch (op) { 2409 case MODULE_STATE_COMING: 2410 btm = kzalloc(sizeof(*btm), GFP_KERNEL); 2411 if (btm) { 2412 btm->module = module; 2413 list_add(&btm->list, &bpf_trace_modules); 2414 } else { 2415 ret = -ENOMEM; 2416 } 2417 break; 2418 case MODULE_STATE_GOING: 2419 list_for_each_entry_safe(btm, tmp, &bpf_trace_modules, list) { 2420 if (btm->module == module) { 2421 list_del(&btm->list); 2422 kfree(btm); 2423 break; 2424 } 2425 } 2426 break; 2427 } 2428 2429 mutex_unlock(&bpf_module_mutex); 2430 2431 out: 2432 return notifier_from_errno(ret); 2433 } 2434 2435 static struct notifier_block bpf_module_nb = { 2436 .notifier_call = bpf_event_notify, 2437 }; 2438 2439 static int __init bpf_event_init(void) 2440 { 2441 register_module_notifier(&bpf_module_nb); 2442 return 0; 2443 } 2444 2445 fs_initcall(bpf_event_init); 2446 #endif /* CONFIG_MODULES */ 2447 2448 #ifdef CONFIG_FPROBE 2449 struct bpf_kprobe_multi_link { 2450 struct bpf_link link; 2451 struct fprobe fp; 2452 unsigned long *addrs; 2453 u64 *cookies; 2454 u32 cnt; 2455 }; 2456 2457 struct bpf_kprobe_multi_run_ctx { 2458 struct bpf_run_ctx run_ctx; 2459 struct bpf_kprobe_multi_link *link; 2460 unsigned long entry_ip; 2461 }; 2462 2463 struct user_syms { 2464 const char **syms; 2465 char *buf; 2466 }; 2467 2468 static int copy_user_syms(struct user_syms *us, unsigned long __user *usyms, u32 cnt) 2469 { 2470 unsigned long __user usymbol; 2471 const char **syms = NULL; 2472 char *buf = NULL, *p; 2473 int err = -ENOMEM; 2474 unsigned int i; 2475 2476 syms = kvmalloc_array(cnt, sizeof(*syms), GFP_KERNEL); 2477 if (!syms) 2478 goto error; 2479 2480 buf = kvmalloc_array(cnt, KSYM_NAME_LEN, GFP_KERNEL); 2481 if (!buf) 2482 goto error; 2483 2484 for (p = buf, i = 0; i < cnt; i++) { 2485 if (__get_user(usymbol, usyms + i)) { 2486 err = -EFAULT; 2487 goto error; 2488 } 2489 err = strncpy_from_user(p, (const char __user *) usymbol, KSYM_NAME_LEN); 2490 if (err == KSYM_NAME_LEN) 2491 err = -E2BIG; 2492 if (err < 0) 2493 goto error; 2494 syms[i] = p; 2495 p += err + 1; 2496 } 2497 2498 us->syms = syms; 2499 us->buf = buf; 2500 return 0; 2501 2502 error: 2503 if (err) { 2504 kvfree(syms); 2505 kvfree(buf); 2506 } 2507 return err; 2508 } 2509 2510 static void free_user_syms(struct user_syms *us) 2511 { 2512 kvfree(us->syms); 2513 kvfree(us->buf); 2514 } 2515 2516 static void bpf_kprobe_multi_link_release(struct bpf_link *link) 2517 { 2518 struct bpf_kprobe_multi_link *kmulti_link; 2519 2520 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); 2521 unregister_fprobe(&kmulti_link->fp); 2522 } 2523 2524 static void bpf_kprobe_multi_link_dealloc(struct bpf_link *link) 2525 { 2526 struct bpf_kprobe_multi_link *kmulti_link; 2527 2528 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); 2529 kvfree(kmulti_link->addrs); 2530 kvfree(kmulti_link->cookies); 2531 kfree(kmulti_link); 2532 } 2533 2534 static const struct bpf_link_ops bpf_kprobe_multi_link_lops = { 2535 .release = bpf_kprobe_multi_link_release, 2536 .dealloc = bpf_kprobe_multi_link_dealloc, 2537 }; 2538 2539 static void bpf_kprobe_multi_cookie_swap(void *a, void *b, int size, const void *priv) 2540 { 2541 const struct bpf_kprobe_multi_link *link = priv; 2542 unsigned long *addr_a = a, *addr_b = b; 2543 u64 *cookie_a, *cookie_b; 2544 2545 cookie_a = link->cookies + (addr_a - link->addrs); 2546 cookie_b = link->cookies + (addr_b - link->addrs); 2547 2548 /* swap addr_a/addr_b and cookie_a/cookie_b values */ 2549 swap(*addr_a, *addr_b); 2550 swap(*cookie_a, *cookie_b); 2551 } 2552 2553 static int __bpf_kprobe_multi_cookie_cmp(const void *a, const void *b) 2554 { 2555 const unsigned long *addr_a = a, *addr_b = b; 2556 2557 if (*addr_a == *addr_b) 2558 return 0; 2559 return *addr_a < *addr_b ? -1 : 1; 2560 } 2561 2562 static int bpf_kprobe_multi_cookie_cmp(const void *a, const void *b, const void *priv) 2563 { 2564 return __bpf_kprobe_multi_cookie_cmp(a, b); 2565 } 2566 2567 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx) 2568 { 2569 struct bpf_kprobe_multi_run_ctx *run_ctx; 2570 struct bpf_kprobe_multi_link *link; 2571 u64 *cookie, entry_ip; 2572 unsigned long *addr; 2573 2574 if (WARN_ON_ONCE(!ctx)) 2575 return 0; 2576 run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, run_ctx); 2577 link = run_ctx->link; 2578 if (!link->cookies) 2579 return 0; 2580 entry_ip = run_ctx->entry_ip; 2581 addr = bsearch(&entry_ip, link->addrs, link->cnt, sizeof(entry_ip), 2582 __bpf_kprobe_multi_cookie_cmp); 2583 if (!addr) 2584 return 0; 2585 cookie = link->cookies + (addr - link->addrs); 2586 return *cookie; 2587 } 2588 2589 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 2590 { 2591 struct bpf_kprobe_multi_run_ctx *run_ctx; 2592 2593 run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, run_ctx); 2594 return run_ctx->entry_ip; 2595 } 2596 2597 static int 2598 kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link, 2599 unsigned long entry_ip, struct pt_regs *regs) 2600 { 2601 struct bpf_kprobe_multi_run_ctx run_ctx = { 2602 .link = link, 2603 .entry_ip = entry_ip, 2604 }; 2605 struct bpf_run_ctx *old_run_ctx; 2606 int err; 2607 2608 if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) { 2609 err = 0; 2610 goto out; 2611 } 2612 2613 migrate_disable(); 2614 rcu_read_lock(); 2615 old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx); 2616 err = bpf_prog_run(link->link.prog, regs); 2617 bpf_reset_run_ctx(old_run_ctx); 2618 rcu_read_unlock(); 2619 migrate_enable(); 2620 2621 out: 2622 __this_cpu_dec(bpf_prog_active); 2623 return err; 2624 } 2625 2626 static void 2627 kprobe_multi_link_handler(struct fprobe *fp, unsigned long fentry_ip, 2628 struct pt_regs *regs) 2629 { 2630 struct bpf_kprobe_multi_link *link; 2631 2632 link = container_of(fp, struct bpf_kprobe_multi_link, fp); 2633 kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), regs); 2634 } 2635 2636 static int symbols_cmp_r(const void *a, const void *b, const void *priv) 2637 { 2638 const char **str_a = (const char **) a; 2639 const char **str_b = (const char **) b; 2640 2641 return strcmp(*str_a, *str_b); 2642 } 2643 2644 struct multi_symbols_sort { 2645 const char **funcs; 2646 u64 *cookies; 2647 }; 2648 2649 static void symbols_swap_r(void *a, void *b, int size, const void *priv) 2650 { 2651 const struct multi_symbols_sort *data = priv; 2652 const char **name_a = a, **name_b = b; 2653 2654 swap(*name_a, *name_b); 2655 2656 /* If defined, swap also related cookies. */ 2657 if (data->cookies) { 2658 u64 *cookie_a, *cookie_b; 2659 2660 cookie_a = data->cookies + (name_a - data->funcs); 2661 cookie_b = data->cookies + (name_b - data->funcs); 2662 swap(*cookie_a, *cookie_b); 2663 } 2664 } 2665 2666 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 2667 { 2668 struct bpf_kprobe_multi_link *link = NULL; 2669 struct bpf_link_primer link_primer; 2670 void __user *ucookies; 2671 unsigned long *addrs; 2672 u32 flags, cnt, size; 2673 void __user *uaddrs; 2674 u64 *cookies = NULL; 2675 void __user *usyms; 2676 int err; 2677 2678 /* no support for 32bit archs yet */ 2679 if (sizeof(u64) != sizeof(void *)) 2680 return -EOPNOTSUPP; 2681 2682 if (prog->expected_attach_type != BPF_TRACE_KPROBE_MULTI) 2683 return -EINVAL; 2684 2685 flags = attr->link_create.kprobe_multi.flags; 2686 if (flags & ~BPF_F_KPROBE_MULTI_RETURN) 2687 return -EINVAL; 2688 2689 uaddrs = u64_to_user_ptr(attr->link_create.kprobe_multi.addrs); 2690 usyms = u64_to_user_ptr(attr->link_create.kprobe_multi.syms); 2691 if (!!uaddrs == !!usyms) 2692 return -EINVAL; 2693 2694 cnt = attr->link_create.kprobe_multi.cnt; 2695 if (!cnt) 2696 return -EINVAL; 2697 2698 size = cnt * sizeof(*addrs); 2699 addrs = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL); 2700 if (!addrs) 2701 return -ENOMEM; 2702 2703 ucookies = u64_to_user_ptr(attr->link_create.kprobe_multi.cookies); 2704 if (ucookies) { 2705 cookies = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL); 2706 if (!cookies) { 2707 err = -ENOMEM; 2708 goto error; 2709 } 2710 if (copy_from_user(cookies, ucookies, size)) { 2711 err = -EFAULT; 2712 goto error; 2713 } 2714 } 2715 2716 if (uaddrs) { 2717 if (copy_from_user(addrs, uaddrs, size)) { 2718 err = -EFAULT; 2719 goto error; 2720 } 2721 } else { 2722 struct multi_symbols_sort data = { 2723 .cookies = cookies, 2724 }; 2725 struct user_syms us; 2726 2727 err = copy_user_syms(&us, usyms, cnt); 2728 if (err) 2729 goto error; 2730 2731 if (cookies) 2732 data.funcs = us.syms; 2733 2734 sort_r(us.syms, cnt, sizeof(*us.syms), symbols_cmp_r, 2735 symbols_swap_r, &data); 2736 2737 err = ftrace_lookup_symbols(us.syms, cnt, addrs); 2738 free_user_syms(&us); 2739 if (err) 2740 goto error; 2741 } 2742 2743 link = kzalloc(sizeof(*link), GFP_KERNEL); 2744 if (!link) { 2745 err = -ENOMEM; 2746 goto error; 2747 } 2748 2749 bpf_link_init(&link->link, BPF_LINK_TYPE_KPROBE_MULTI, 2750 &bpf_kprobe_multi_link_lops, prog); 2751 2752 err = bpf_link_prime(&link->link, &link_primer); 2753 if (err) 2754 goto error; 2755 2756 if (flags & BPF_F_KPROBE_MULTI_RETURN) 2757 link->fp.exit_handler = kprobe_multi_link_handler; 2758 else 2759 link->fp.entry_handler = kprobe_multi_link_handler; 2760 2761 link->addrs = addrs; 2762 link->cookies = cookies; 2763 link->cnt = cnt; 2764 2765 if (cookies) { 2766 /* 2767 * Sorting addresses will trigger sorting cookies as well 2768 * (check bpf_kprobe_multi_cookie_swap). This way we can 2769 * find cookie based on the address in bpf_get_attach_cookie 2770 * helper. 2771 */ 2772 sort_r(addrs, cnt, sizeof(*addrs), 2773 bpf_kprobe_multi_cookie_cmp, 2774 bpf_kprobe_multi_cookie_swap, 2775 link); 2776 } 2777 2778 err = register_fprobe_ips(&link->fp, addrs, cnt); 2779 if (err) { 2780 bpf_link_cleanup(&link_primer); 2781 return err; 2782 } 2783 2784 return bpf_link_settle(&link_primer); 2785 2786 error: 2787 kfree(link); 2788 kvfree(addrs); 2789 kvfree(cookies); 2790 return err; 2791 } 2792 #else /* !CONFIG_FPROBE */ 2793 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 2794 { 2795 return -EOPNOTSUPP; 2796 } 2797 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx) 2798 { 2799 return 0; 2800 } 2801 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 2802 { 2803 return 0; 2804 } 2805 #endif 2806