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; 690 691 err = __bpf_perf_event_output(regs, map, flags, sd); 692 693 out: 694 this_cpu_dec(bpf_trace_nest_level); 695 return err; 696 } 697 698 static const struct bpf_func_proto bpf_perf_event_output_proto = { 699 .func = bpf_perf_event_output, 700 .gpl_only = true, 701 .ret_type = RET_INTEGER, 702 .arg1_type = ARG_PTR_TO_CTX, 703 .arg2_type = ARG_CONST_MAP_PTR, 704 .arg3_type = ARG_ANYTHING, 705 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, 706 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 707 }; 708 709 static DEFINE_PER_CPU(int, bpf_event_output_nest_level); 710 struct bpf_nested_pt_regs { 711 struct pt_regs regs[3]; 712 }; 713 static DEFINE_PER_CPU(struct bpf_nested_pt_regs, bpf_pt_regs); 714 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_misc_sds); 715 716 u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size, 717 void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy) 718 { 719 int nest_level = this_cpu_inc_return(bpf_event_output_nest_level); 720 struct perf_raw_frag frag = { 721 .copy = ctx_copy, 722 .size = ctx_size, 723 .data = ctx, 724 }; 725 struct perf_raw_record raw = { 726 .frag = { 727 { 728 .next = ctx_size ? &frag : NULL, 729 }, 730 .size = meta_size, 731 .data = meta, 732 }, 733 }; 734 struct perf_sample_data *sd; 735 struct pt_regs *regs; 736 u64 ret; 737 738 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(bpf_misc_sds.sds))) { 739 ret = -EBUSY; 740 goto out; 741 } 742 sd = this_cpu_ptr(&bpf_misc_sds.sds[nest_level - 1]); 743 regs = this_cpu_ptr(&bpf_pt_regs.regs[nest_level - 1]); 744 745 perf_fetch_caller_regs(regs); 746 perf_sample_data_init(sd, 0, 0); 747 sd->raw = &raw; 748 749 ret = __bpf_perf_event_output(regs, map, flags, sd); 750 out: 751 this_cpu_dec(bpf_event_output_nest_level); 752 return ret; 753 } 754 755 BPF_CALL_0(bpf_get_current_task) 756 { 757 return (long) current; 758 } 759 760 const struct bpf_func_proto bpf_get_current_task_proto = { 761 .func = bpf_get_current_task, 762 .gpl_only = true, 763 .ret_type = RET_INTEGER, 764 }; 765 766 BPF_CALL_0(bpf_get_current_task_btf) 767 { 768 return (unsigned long) current; 769 } 770 771 const struct bpf_func_proto bpf_get_current_task_btf_proto = { 772 .func = bpf_get_current_task_btf, 773 .gpl_only = true, 774 .ret_type = RET_PTR_TO_BTF_ID, 775 .ret_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK], 776 }; 777 778 BPF_CALL_1(bpf_task_pt_regs, struct task_struct *, task) 779 { 780 return (unsigned long) task_pt_regs(task); 781 } 782 783 BTF_ID_LIST(bpf_task_pt_regs_ids) 784 BTF_ID(struct, pt_regs) 785 786 const struct bpf_func_proto bpf_task_pt_regs_proto = { 787 .func = bpf_task_pt_regs, 788 .gpl_only = true, 789 .arg1_type = ARG_PTR_TO_BTF_ID, 790 .arg1_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK], 791 .ret_type = RET_PTR_TO_BTF_ID, 792 .ret_btf_id = &bpf_task_pt_regs_ids[0], 793 }; 794 795 BPF_CALL_2(bpf_current_task_under_cgroup, struct bpf_map *, map, u32, idx) 796 { 797 struct bpf_array *array = container_of(map, struct bpf_array, map); 798 struct cgroup *cgrp; 799 800 if (unlikely(idx >= array->map.max_entries)) 801 return -E2BIG; 802 803 cgrp = READ_ONCE(array->ptrs[idx]); 804 if (unlikely(!cgrp)) 805 return -EAGAIN; 806 807 return task_under_cgroup_hierarchy(current, cgrp); 808 } 809 810 static const struct bpf_func_proto bpf_current_task_under_cgroup_proto = { 811 .func = bpf_current_task_under_cgroup, 812 .gpl_only = false, 813 .ret_type = RET_INTEGER, 814 .arg1_type = ARG_CONST_MAP_PTR, 815 .arg2_type = ARG_ANYTHING, 816 }; 817 818 struct send_signal_irq_work { 819 struct irq_work irq_work; 820 struct task_struct *task; 821 u32 sig; 822 enum pid_type type; 823 }; 824 825 static DEFINE_PER_CPU(struct send_signal_irq_work, send_signal_work); 826 827 static void do_bpf_send_signal(struct irq_work *entry) 828 { 829 struct send_signal_irq_work *work; 830 831 work = container_of(entry, struct send_signal_irq_work, irq_work); 832 group_send_sig_info(work->sig, SEND_SIG_PRIV, work->task, work->type); 833 } 834 835 static int bpf_send_signal_common(u32 sig, enum pid_type type) 836 { 837 struct send_signal_irq_work *work = NULL; 838 839 /* Similar to bpf_probe_write_user, task needs to be 840 * in a sound condition and kernel memory access be 841 * permitted in order to send signal to the current 842 * task. 843 */ 844 if (unlikely(current->flags & (PF_KTHREAD | PF_EXITING))) 845 return -EPERM; 846 if (unlikely(!nmi_uaccess_okay())) 847 return -EPERM; 848 849 if (irqs_disabled()) { 850 /* Do an early check on signal validity. Otherwise, 851 * the error is lost in deferred irq_work. 852 */ 853 if (unlikely(!valid_signal(sig))) 854 return -EINVAL; 855 856 work = this_cpu_ptr(&send_signal_work); 857 if (irq_work_is_busy(&work->irq_work)) 858 return -EBUSY; 859 860 /* Add the current task, which is the target of sending signal, 861 * to the irq_work. The current task may change when queued 862 * irq works get executed. 863 */ 864 work->task = current; 865 work->sig = sig; 866 work->type = type; 867 irq_work_queue(&work->irq_work); 868 return 0; 869 } 870 871 return group_send_sig_info(sig, SEND_SIG_PRIV, current, type); 872 } 873 874 BPF_CALL_1(bpf_send_signal, u32, sig) 875 { 876 return bpf_send_signal_common(sig, PIDTYPE_TGID); 877 } 878 879 static const struct bpf_func_proto bpf_send_signal_proto = { 880 .func = bpf_send_signal, 881 .gpl_only = false, 882 .ret_type = RET_INTEGER, 883 .arg1_type = ARG_ANYTHING, 884 }; 885 886 BPF_CALL_1(bpf_send_signal_thread, u32, sig) 887 { 888 return bpf_send_signal_common(sig, PIDTYPE_PID); 889 } 890 891 static const struct bpf_func_proto bpf_send_signal_thread_proto = { 892 .func = bpf_send_signal_thread, 893 .gpl_only = false, 894 .ret_type = RET_INTEGER, 895 .arg1_type = ARG_ANYTHING, 896 }; 897 898 BPF_CALL_3(bpf_d_path, struct path *, path, char *, buf, u32, sz) 899 { 900 long len; 901 char *p; 902 903 if (!sz) 904 return 0; 905 906 p = d_path(path, buf, sz); 907 if (IS_ERR(p)) { 908 len = PTR_ERR(p); 909 } else { 910 len = buf + sz - p; 911 memmove(buf, p, len); 912 } 913 914 return len; 915 } 916 917 BTF_SET_START(btf_allowlist_d_path) 918 #ifdef CONFIG_SECURITY 919 BTF_ID(func, security_file_permission) 920 BTF_ID(func, security_inode_getattr) 921 BTF_ID(func, security_file_open) 922 #endif 923 #ifdef CONFIG_SECURITY_PATH 924 BTF_ID(func, security_path_truncate) 925 #endif 926 BTF_ID(func, vfs_truncate) 927 BTF_ID(func, vfs_fallocate) 928 BTF_ID(func, dentry_open) 929 BTF_ID(func, vfs_getattr) 930 BTF_ID(func, filp_close) 931 BTF_SET_END(btf_allowlist_d_path) 932 933 static bool bpf_d_path_allowed(const struct bpf_prog *prog) 934 { 935 if (prog->type == BPF_PROG_TYPE_TRACING && 936 prog->expected_attach_type == BPF_TRACE_ITER) 937 return true; 938 939 if (prog->type == BPF_PROG_TYPE_LSM) 940 return bpf_lsm_is_sleepable_hook(prog->aux->attach_btf_id); 941 942 return btf_id_set_contains(&btf_allowlist_d_path, 943 prog->aux->attach_btf_id); 944 } 945 946 BTF_ID_LIST_SINGLE(bpf_d_path_btf_ids, struct, path) 947 948 static const struct bpf_func_proto bpf_d_path_proto = { 949 .func = bpf_d_path, 950 .gpl_only = false, 951 .ret_type = RET_INTEGER, 952 .arg1_type = ARG_PTR_TO_BTF_ID, 953 .arg1_btf_id = &bpf_d_path_btf_ids[0], 954 .arg2_type = ARG_PTR_TO_MEM, 955 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 956 .allowed = bpf_d_path_allowed, 957 }; 958 959 #define BTF_F_ALL (BTF_F_COMPACT | BTF_F_NONAME | \ 960 BTF_F_PTR_RAW | BTF_F_ZERO) 961 962 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size, 963 u64 flags, const struct btf **btf, 964 s32 *btf_id) 965 { 966 const struct btf_type *t; 967 968 if (unlikely(flags & ~(BTF_F_ALL))) 969 return -EINVAL; 970 971 if (btf_ptr_size != sizeof(struct btf_ptr)) 972 return -EINVAL; 973 974 *btf = bpf_get_btf_vmlinux(); 975 976 if (IS_ERR_OR_NULL(*btf)) 977 return IS_ERR(*btf) ? PTR_ERR(*btf) : -EINVAL; 978 979 if (ptr->type_id > 0) 980 *btf_id = ptr->type_id; 981 else 982 return -EINVAL; 983 984 if (*btf_id > 0) 985 t = btf_type_by_id(*btf, *btf_id); 986 if (*btf_id <= 0 || !t) 987 return -ENOENT; 988 989 return 0; 990 } 991 992 BPF_CALL_5(bpf_snprintf_btf, char *, str, u32, str_size, struct btf_ptr *, ptr, 993 u32, btf_ptr_size, u64, flags) 994 { 995 const struct btf *btf; 996 s32 btf_id; 997 int ret; 998 999 ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id); 1000 if (ret) 1001 return ret; 1002 1003 return btf_type_snprintf_show(btf, btf_id, ptr->ptr, str, str_size, 1004 flags); 1005 } 1006 1007 const struct bpf_func_proto bpf_snprintf_btf_proto = { 1008 .func = bpf_snprintf_btf, 1009 .gpl_only = false, 1010 .ret_type = RET_INTEGER, 1011 .arg1_type = ARG_PTR_TO_MEM, 1012 .arg2_type = ARG_CONST_SIZE, 1013 .arg3_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1014 .arg4_type = ARG_CONST_SIZE, 1015 .arg5_type = ARG_ANYTHING, 1016 }; 1017 1018 BPF_CALL_1(bpf_get_func_ip_tracing, void *, ctx) 1019 { 1020 /* This helper call is inlined by verifier. */ 1021 return ((u64 *)ctx)[-2]; 1022 } 1023 1024 static const struct bpf_func_proto bpf_get_func_ip_proto_tracing = { 1025 .func = bpf_get_func_ip_tracing, 1026 .gpl_only = true, 1027 .ret_type = RET_INTEGER, 1028 .arg1_type = ARG_PTR_TO_CTX, 1029 }; 1030 1031 #ifdef CONFIG_X86_KERNEL_IBT 1032 static unsigned long get_entry_ip(unsigned long fentry_ip) 1033 { 1034 u32 instr; 1035 1036 /* Being extra safe in here in case entry ip is on the page-edge. */ 1037 if (get_kernel_nofault(instr, (u32 *) fentry_ip - 1)) 1038 return fentry_ip; 1039 if (is_endbr(instr)) 1040 fentry_ip -= ENDBR_INSN_SIZE; 1041 return fentry_ip; 1042 } 1043 #else 1044 #define get_entry_ip(fentry_ip) fentry_ip 1045 #endif 1046 1047 BPF_CALL_1(bpf_get_func_ip_kprobe, struct pt_regs *, regs) 1048 { 1049 struct kprobe *kp = kprobe_running(); 1050 1051 if (!kp || !(kp->flags & KPROBE_FLAG_ON_FUNC_ENTRY)) 1052 return 0; 1053 1054 return get_entry_ip((uintptr_t)kp->addr); 1055 } 1056 1057 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe = { 1058 .func = bpf_get_func_ip_kprobe, 1059 .gpl_only = true, 1060 .ret_type = RET_INTEGER, 1061 .arg1_type = ARG_PTR_TO_CTX, 1062 }; 1063 1064 BPF_CALL_1(bpf_get_func_ip_kprobe_multi, struct pt_regs *, regs) 1065 { 1066 return bpf_kprobe_multi_entry_ip(current->bpf_ctx); 1067 } 1068 1069 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe_multi = { 1070 .func = bpf_get_func_ip_kprobe_multi, 1071 .gpl_only = false, 1072 .ret_type = RET_INTEGER, 1073 .arg1_type = ARG_PTR_TO_CTX, 1074 }; 1075 1076 BPF_CALL_1(bpf_get_attach_cookie_kprobe_multi, struct pt_regs *, regs) 1077 { 1078 return bpf_kprobe_multi_cookie(current->bpf_ctx); 1079 } 1080 1081 static const struct bpf_func_proto bpf_get_attach_cookie_proto_kmulti = { 1082 .func = bpf_get_attach_cookie_kprobe_multi, 1083 .gpl_only = false, 1084 .ret_type = RET_INTEGER, 1085 .arg1_type = ARG_PTR_TO_CTX, 1086 }; 1087 1088 BPF_CALL_1(bpf_get_attach_cookie_trace, void *, ctx) 1089 { 1090 struct bpf_trace_run_ctx *run_ctx; 1091 1092 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); 1093 return run_ctx->bpf_cookie; 1094 } 1095 1096 static const struct bpf_func_proto bpf_get_attach_cookie_proto_trace = { 1097 .func = bpf_get_attach_cookie_trace, 1098 .gpl_only = false, 1099 .ret_type = RET_INTEGER, 1100 .arg1_type = ARG_PTR_TO_CTX, 1101 }; 1102 1103 BPF_CALL_1(bpf_get_attach_cookie_pe, struct bpf_perf_event_data_kern *, ctx) 1104 { 1105 return ctx->event->bpf_cookie; 1106 } 1107 1108 static const struct bpf_func_proto bpf_get_attach_cookie_proto_pe = { 1109 .func = bpf_get_attach_cookie_pe, 1110 .gpl_only = false, 1111 .ret_type = RET_INTEGER, 1112 .arg1_type = ARG_PTR_TO_CTX, 1113 }; 1114 1115 BPF_CALL_1(bpf_get_attach_cookie_tracing, void *, ctx) 1116 { 1117 struct bpf_trace_run_ctx *run_ctx; 1118 1119 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); 1120 return run_ctx->bpf_cookie; 1121 } 1122 1123 static const struct bpf_func_proto bpf_get_attach_cookie_proto_tracing = { 1124 .func = bpf_get_attach_cookie_tracing, 1125 .gpl_only = false, 1126 .ret_type = RET_INTEGER, 1127 .arg1_type = ARG_PTR_TO_CTX, 1128 }; 1129 1130 BPF_CALL_3(bpf_get_branch_snapshot, void *, buf, u32, size, u64, flags) 1131 { 1132 #ifndef CONFIG_X86 1133 return -ENOENT; 1134 #else 1135 static const u32 br_entry_size = sizeof(struct perf_branch_entry); 1136 u32 entry_cnt = size / br_entry_size; 1137 1138 entry_cnt = static_call(perf_snapshot_branch_stack)(buf, entry_cnt); 1139 1140 if (unlikely(flags)) 1141 return -EINVAL; 1142 1143 if (!entry_cnt) 1144 return -ENOENT; 1145 1146 return entry_cnt * br_entry_size; 1147 #endif 1148 } 1149 1150 static const struct bpf_func_proto bpf_get_branch_snapshot_proto = { 1151 .func = bpf_get_branch_snapshot, 1152 .gpl_only = true, 1153 .ret_type = RET_INTEGER, 1154 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 1155 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 1156 }; 1157 1158 BPF_CALL_3(get_func_arg, void *, ctx, u32, n, u64 *, value) 1159 { 1160 /* This helper call is inlined by verifier. */ 1161 u64 nr_args = ((u64 *)ctx)[-1]; 1162 1163 if ((u64) n >= nr_args) 1164 return -EINVAL; 1165 *value = ((u64 *)ctx)[n]; 1166 return 0; 1167 } 1168 1169 static const struct bpf_func_proto bpf_get_func_arg_proto = { 1170 .func = get_func_arg, 1171 .ret_type = RET_INTEGER, 1172 .arg1_type = ARG_PTR_TO_CTX, 1173 .arg2_type = ARG_ANYTHING, 1174 .arg3_type = ARG_PTR_TO_LONG, 1175 }; 1176 1177 BPF_CALL_2(get_func_ret, void *, ctx, u64 *, value) 1178 { 1179 /* This helper call is inlined by verifier. */ 1180 u64 nr_args = ((u64 *)ctx)[-1]; 1181 1182 *value = ((u64 *)ctx)[nr_args]; 1183 return 0; 1184 } 1185 1186 static const struct bpf_func_proto bpf_get_func_ret_proto = { 1187 .func = get_func_ret, 1188 .ret_type = RET_INTEGER, 1189 .arg1_type = ARG_PTR_TO_CTX, 1190 .arg2_type = ARG_PTR_TO_LONG, 1191 }; 1192 1193 BPF_CALL_1(get_func_arg_cnt, void *, ctx) 1194 { 1195 /* This helper call is inlined by verifier. */ 1196 return ((u64 *)ctx)[-1]; 1197 } 1198 1199 static const struct bpf_func_proto bpf_get_func_arg_cnt_proto = { 1200 .func = get_func_arg_cnt, 1201 .ret_type = RET_INTEGER, 1202 .arg1_type = ARG_PTR_TO_CTX, 1203 }; 1204 1205 #ifdef CONFIG_KEYS 1206 __diag_push(); 1207 __diag_ignore_all("-Wmissing-prototypes", 1208 "kfuncs which will be used in BPF programs"); 1209 1210 /** 1211 * bpf_lookup_user_key - lookup a key by its serial 1212 * @serial: key handle serial number 1213 * @flags: lookup-specific flags 1214 * 1215 * Search a key with a given *serial* and the provided *flags*. 1216 * If found, increment the reference count of the key by one, and 1217 * return it in the bpf_key structure. 1218 * 1219 * The bpf_key structure must be passed to bpf_key_put() when done 1220 * with it, so that the key reference count is decremented and the 1221 * bpf_key structure is freed. 1222 * 1223 * Permission checks are deferred to the time the key is used by 1224 * one of the available key-specific kfuncs. 1225 * 1226 * Set *flags* with KEY_LOOKUP_CREATE, to attempt creating a requested 1227 * special keyring (e.g. session keyring), if it doesn't yet exist. 1228 * Set *flags* with KEY_LOOKUP_PARTIAL, to lookup a key without waiting 1229 * for the key construction, and to retrieve uninstantiated keys (keys 1230 * without data attached to them). 1231 * 1232 * Return: a bpf_key pointer with a valid key pointer if the key is found, a 1233 * NULL pointer otherwise. 1234 */ 1235 struct bpf_key *bpf_lookup_user_key(u32 serial, u64 flags) 1236 { 1237 key_ref_t key_ref; 1238 struct bpf_key *bkey; 1239 1240 if (flags & ~KEY_LOOKUP_ALL) 1241 return NULL; 1242 1243 /* 1244 * Permission check is deferred until the key is used, as the 1245 * intent of the caller is unknown here. 1246 */ 1247 key_ref = lookup_user_key(serial, flags, KEY_DEFER_PERM_CHECK); 1248 if (IS_ERR(key_ref)) 1249 return NULL; 1250 1251 bkey = kmalloc(sizeof(*bkey), GFP_KERNEL); 1252 if (!bkey) { 1253 key_put(key_ref_to_ptr(key_ref)); 1254 return NULL; 1255 } 1256 1257 bkey->key = key_ref_to_ptr(key_ref); 1258 bkey->has_ref = true; 1259 1260 return bkey; 1261 } 1262 1263 /** 1264 * bpf_lookup_system_key - lookup a key by a system-defined ID 1265 * @id: key ID 1266 * 1267 * Obtain a bpf_key structure with a key pointer set to the passed key ID. 1268 * The key pointer is marked as invalid, to prevent bpf_key_put() from 1269 * attempting to decrement the key reference count on that pointer. The key 1270 * pointer set in such way is currently understood only by 1271 * verify_pkcs7_signature(). 1272 * 1273 * Set *id* to one of the values defined in include/linux/verification.h: 1274 * 0 for the primary keyring (immutable keyring of system keys); 1275 * VERIFY_USE_SECONDARY_KEYRING for both the primary and secondary keyring 1276 * (where keys can be added only if they are vouched for by existing keys 1277 * in those keyrings); VERIFY_USE_PLATFORM_KEYRING for the platform 1278 * keyring (primarily used by the integrity subsystem to verify a kexec'ed 1279 * kerned image and, possibly, the initramfs signature). 1280 * 1281 * Return: a bpf_key pointer with an invalid key pointer set from the 1282 * pre-determined ID on success, a NULL pointer otherwise 1283 */ 1284 struct bpf_key *bpf_lookup_system_key(u64 id) 1285 { 1286 struct bpf_key *bkey; 1287 1288 if (system_keyring_id_check(id) < 0) 1289 return NULL; 1290 1291 bkey = kmalloc(sizeof(*bkey), GFP_ATOMIC); 1292 if (!bkey) 1293 return NULL; 1294 1295 bkey->key = (struct key *)(unsigned long)id; 1296 bkey->has_ref = false; 1297 1298 return bkey; 1299 } 1300 1301 /** 1302 * bpf_key_put - decrement key reference count if key is valid and free bpf_key 1303 * @bkey: bpf_key structure 1304 * 1305 * Decrement the reference count of the key inside *bkey*, if the pointer 1306 * is valid, and free *bkey*. 1307 */ 1308 void bpf_key_put(struct bpf_key *bkey) 1309 { 1310 if (bkey->has_ref) 1311 key_put(bkey->key); 1312 1313 kfree(bkey); 1314 } 1315 1316 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION 1317 /** 1318 * bpf_verify_pkcs7_signature - verify a PKCS#7 signature 1319 * @data_ptr: data to verify 1320 * @sig_ptr: signature of the data 1321 * @trusted_keyring: keyring with keys trusted for signature verification 1322 * 1323 * Verify the PKCS#7 signature *sig_ptr* against the supplied *data_ptr* 1324 * with keys in a keyring referenced by *trusted_keyring*. 1325 * 1326 * Return: 0 on success, a negative value on error. 1327 */ 1328 int bpf_verify_pkcs7_signature(struct bpf_dynptr_kern *data_ptr, 1329 struct bpf_dynptr_kern *sig_ptr, 1330 struct bpf_key *trusted_keyring) 1331 { 1332 int ret; 1333 1334 if (trusted_keyring->has_ref) { 1335 /* 1336 * Do the permission check deferred in bpf_lookup_user_key(). 1337 * See bpf_lookup_user_key() for more details. 1338 * 1339 * A call to key_task_permission() here would be redundant, as 1340 * it is already done by keyring_search() called by 1341 * find_asymmetric_key(). 1342 */ 1343 ret = key_validate(trusted_keyring->key); 1344 if (ret < 0) 1345 return ret; 1346 } 1347 1348 return verify_pkcs7_signature(data_ptr->data, 1349 bpf_dynptr_get_size(data_ptr), 1350 sig_ptr->data, 1351 bpf_dynptr_get_size(sig_ptr), 1352 trusted_keyring->key, 1353 VERIFYING_UNSPECIFIED_SIGNATURE, NULL, 1354 NULL); 1355 } 1356 #endif /* CONFIG_SYSTEM_DATA_VERIFICATION */ 1357 1358 __diag_pop(); 1359 1360 BTF_SET8_START(key_sig_kfunc_set) 1361 BTF_ID_FLAGS(func, bpf_lookup_user_key, KF_ACQUIRE | KF_RET_NULL | KF_SLEEPABLE) 1362 BTF_ID_FLAGS(func, bpf_lookup_system_key, KF_ACQUIRE | KF_RET_NULL) 1363 BTF_ID_FLAGS(func, bpf_key_put, KF_RELEASE) 1364 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION 1365 BTF_ID_FLAGS(func, bpf_verify_pkcs7_signature, KF_SLEEPABLE) 1366 #endif 1367 BTF_SET8_END(key_sig_kfunc_set) 1368 1369 static const struct btf_kfunc_id_set bpf_key_sig_kfunc_set = { 1370 .owner = THIS_MODULE, 1371 .set = &key_sig_kfunc_set, 1372 }; 1373 1374 static int __init bpf_key_sig_kfuncs_init(void) 1375 { 1376 return register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, 1377 &bpf_key_sig_kfunc_set); 1378 } 1379 1380 late_initcall(bpf_key_sig_kfuncs_init); 1381 #endif /* CONFIG_KEYS */ 1382 1383 static const struct bpf_func_proto * 1384 bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1385 { 1386 switch (func_id) { 1387 case BPF_FUNC_map_lookup_elem: 1388 return &bpf_map_lookup_elem_proto; 1389 case BPF_FUNC_map_update_elem: 1390 return &bpf_map_update_elem_proto; 1391 case BPF_FUNC_map_delete_elem: 1392 return &bpf_map_delete_elem_proto; 1393 case BPF_FUNC_map_push_elem: 1394 return &bpf_map_push_elem_proto; 1395 case BPF_FUNC_map_pop_elem: 1396 return &bpf_map_pop_elem_proto; 1397 case BPF_FUNC_map_peek_elem: 1398 return &bpf_map_peek_elem_proto; 1399 case BPF_FUNC_map_lookup_percpu_elem: 1400 return &bpf_map_lookup_percpu_elem_proto; 1401 case BPF_FUNC_ktime_get_ns: 1402 return &bpf_ktime_get_ns_proto; 1403 case BPF_FUNC_ktime_get_boot_ns: 1404 return &bpf_ktime_get_boot_ns_proto; 1405 case BPF_FUNC_tail_call: 1406 return &bpf_tail_call_proto; 1407 case BPF_FUNC_get_current_pid_tgid: 1408 return &bpf_get_current_pid_tgid_proto; 1409 case BPF_FUNC_get_current_task: 1410 return &bpf_get_current_task_proto; 1411 case BPF_FUNC_get_current_task_btf: 1412 return &bpf_get_current_task_btf_proto; 1413 case BPF_FUNC_task_pt_regs: 1414 return &bpf_task_pt_regs_proto; 1415 case BPF_FUNC_get_current_uid_gid: 1416 return &bpf_get_current_uid_gid_proto; 1417 case BPF_FUNC_get_current_comm: 1418 return &bpf_get_current_comm_proto; 1419 case BPF_FUNC_trace_printk: 1420 return bpf_get_trace_printk_proto(); 1421 case BPF_FUNC_get_smp_processor_id: 1422 return &bpf_get_smp_processor_id_proto; 1423 case BPF_FUNC_get_numa_node_id: 1424 return &bpf_get_numa_node_id_proto; 1425 case BPF_FUNC_perf_event_read: 1426 return &bpf_perf_event_read_proto; 1427 case BPF_FUNC_current_task_under_cgroup: 1428 return &bpf_current_task_under_cgroup_proto; 1429 case BPF_FUNC_get_prandom_u32: 1430 return &bpf_get_prandom_u32_proto; 1431 case BPF_FUNC_probe_write_user: 1432 return security_locked_down(LOCKDOWN_BPF_WRITE_USER) < 0 ? 1433 NULL : bpf_get_probe_write_proto(); 1434 case BPF_FUNC_probe_read_user: 1435 return &bpf_probe_read_user_proto; 1436 case BPF_FUNC_probe_read_kernel: 1437 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1438 NULL : &bpf_probe_read_kernel_proto; 1439 case BPF_FUNC_probe_read_user_str: 1440 return &bpf_probe_read_user_str_proto; 1441 case BPF_FUNC_probe_read_kernel_str: 1442 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1443 NULL : &bpf_probe_read_kernel_str_proto; 1444 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 1445 case BPF_FUNC_probe_read: 1446 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1447 NULL : &bpf_probe_read_compat_proto; 1448 case BPF_FUNC_probe_read_str: 1449 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1450 NULL : &bpf_probe_read_compat_str_proto; 1451 #endif 1452 #ifdef CONFIG_CGROUPS 1453 case BPF_FUNC_get_current_cgroup_id: 1454 return &bpf_get_current_cgroup_id_proto; 1455 case BPF_FUNC_get_current_ancestor_cgroup_id: 1456 return &bpf_get_current_ancestor_cgroup_id_proto; 1457 #endif 1458 case BPF_FUNC_send_signal: 1459 return &bpf_send_signal_proto; 1460 case BPF_FUNC_send_signal_thread: 1461 return &bpf_send_signal_thread_proto; 1462 case BPF_FUNC_perf_event_read_value: 1463 return &bpf_perf_event_read_value_proto; 1464 case BPF_FUNC_get_ns_current_pid_tgid: 1465 return &bpf_get_ns_current_pid_tgid_proto; 1466 case BPF_FUNC_ringbuf_output: 1467 return &bpf_ringbuf_output_proto; 1468 case BPF_FUNC_ringbuf_reserve: 1469 return &bpf_ringbuf_reserve_proto; 1470 case BPF_FUNC_ringbuf_submit: 1471 return &bpf_ringbuf_submit_proto; 1472 case BPF_FUNC_ringbuf_discard: 1473 return &bpf_ringbuf_discard_proto; 1474 case BPF_FUNC_ringbuf_query: 1475 return &bpf_ringbuf_query_proto; 1476 case BPF_FUNC_jiffies64: 1477 return &bpf_jiffies64_proto; 1478 case BPF_FUNC_get_task_stack: 1479 return &bpf_get_task_stack_proto; 1480 case BPF_FUNC_copy_from_user: 1481 return prog->aux->sleepable ? &bpf_copy_from_user_proto : NULL; 1482 case BPF_FUNC_copy_from_user_task: 1483 return prog->aux->sleepable ? &bpf_copy_from_user_task_proto : NULL; 1484 case BPF_FUNC_snprintf_btf: 1485 return &bpf_snprintf_btf_proto; 1486 case BPF_FUNC_per_cpu_ptr: 1487 return &bpf_per_cpu_ptr_proto; 1488 case BPF_FUNC_this_cpu_ptr: 1489 return &bpf_this_cpu_ptr_proto; 1490 case BPF_FUNC_task_storage_get: 1491 return &bpf_task_storage_get_proto; 1492 case BPF_FUNC_task_storage_delete: 1493 return &bpf_task_storage_delete_proto; 1494 case BPF_FUNC_for_each_map_elem: 1495 return &bpf_for_each_map_elem_proto; 1496 case BPF_FUNC_snprintf: 1497 return &bpf_snprintf_proto; 1498 case BPF_FUNC_get_func_ip: 1499 return &bpf_get_func_ip_proto_tracing; 1500 case BPF_FUNC_get_branch_snapshot: 1501 return &bpf_get_branch_snapshot_proto; 1502 case BPF_FUNC_find_vma: 1503 return &bpf_find_vma_proto; 1504 case BPF_FUNC_trace_vprintk: 1505 return bpf_get_trace_vprintk_proto(); 1506 default: 1507 return bpf_base_func_proto(func_id); 1508 } 1509 } 1510 1511 static const struct bpf_func_proto * 1512 kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1513 { 1514 switch (func_id) { 1515 case BPF_FUNC_perf_event_output: 1516 return &bpf_perf_event_output_proto; 1517 case BPF_FUNC_get_stackid: 1518 return &bpf_get_stackid_proto; 1519 case BPF_FUNC_get_stack: 1520 return &bpf_get_stack_proto; 1521 #ifdef CONFIG_BPF_KPROBE_OVERRIDE 1522 case BPF_FUNC_override_return: 1523 return &bpf_override_return_proto; 1524 #endif 1525 case BPF_FUNC_get_func_ip: 1526 return prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI ? 1527 &bpf_get_func_ip_proto_kprobe_multi : 1528 &bpf_get_func_ip_proto_kprobe; 1529 case BPF_FUNC_get_attach_cookie: 1530 return prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI ? 1531 &bpf_get_attach_cookie_proto_kmulti : 1532 &bpf_get_attach_cookie_proto_trace; 1533 default: 1534 return bpf_tracing_func_proto(func_id, prog); 1535 } 1536 } 1537 1538 /* bpf+kprobe programs can access fields of 'struct pt_regs' */ 1539 static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type, 1540 const struct bpf_prog *prog, 1541 struct bpf_insn_access_aux *info) 1542 { 1543 if (off < 0 || off >= sizeof(struct pt_regs)) 1544 return false; 1545 if (type != BPF_READ) 1546 return false; 1547 if (off % size != 0) 1548 return false; 1549 /* 1550 * Assertion for 32 bit to make sure last 8 byte access 1551 * (BPF_DW) to the last 4 byte member is disallowed. 1552 */ 1553 if (off + size > sizeof(struct pt_regs)) 1554 return false; 1555 1556 return true; 1557 } 1558 1559 const struct bpf_verifier_ops kprobe_verifier_ops = { 1560 .get_func_proto = kprobe_prog_func_proto, 1561 .is_valid_access = kprobe_prog_is_valid_access, 1562 }; 1563 1564 const struct bpf_prog_ops kprobe_prog_ops = { 1565 }; 1566 1567 BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map, 1568 u64, flags, void *, data, u64, size) 1569 { 1570 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1571 1572 /* 1573 * r1 points to perf tracepoint buffer where first 8 bytes are hidden 1574 * from bpf program and contain a pointer to 'struct pt_regs'. Fetch it 1575 * from there and call the same bpf_perf_event_output() helper inline. 1576 */ 1577 return ____bpf_perf_event_output(regs, map, flags, data, size); 1578 } 1579 1580 static const struct bpf_func_proto bpf_perf_event_output_proto_tp = { 1581 .func = bpf_perf_event_output_tp, 1582 .gpl_only = true, 1583 .ret_type = RET_INTEGER, 1584 .arg1_type = ARG_PTR_TO_CTX, 1585 .arg2_type = ARG_CONST_MAP_PTR, 1586 .arg3_type = ARG_ANYTHING, 1587 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1588 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 1589 }; 1590 1591 BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map, 1592 u64, flags) 1593 { 1594 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1595 1596 /* 1597 * Same comment as in bpf_perf_event_output_tp(), only that this time 1598 * the other helper's function body cannot be inlined due to being 1599 * external, thus we need to call raw helper function. 1600 */ 1601 return bpf_get_stackid((unsigned long) regs, (unsigned long) map, 1602 flags, 0, 0); 1603 } 1604 1605 static const struct bpf_func_proto bpf_get_stackid_proto_tp = { 1606 .func = bpf_get_stackid_tp, 1607 .gpl_only = true, 1608 .ret_type = RET_INTEGER, 1609 .arg1_type = ARG_PTR_TO_CTX, 1610 .arg2_type = ARG_CONST_MAP_PTR, 1611 .arg3_type = ARG_ANYTHING, 1612 }; 1613 1614 BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size, 1615 u64, flags) 1616 { 1617 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1618 1619 return bpf_get_stack((unsigned long) regs, (unsigned long) buf, 1620 (unsigned long) size, flags, 0); 1621 } 1622 1623 static const struct bpf_func_proto bpf_get_stack_proto_tp = { 1624 .func = bpf_get_stack_tp, 1625 .gpl_only = true, 1626 .ret_type = RET_INTEGER, 1627 .arg1_type = ARG_PTR_TO_CTX, 1628 .arg2_type = ARG_PTR_TO_UNINIT_MEM, 1629 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1630 .arg4_type = ARG_ANYTHING, 1631 }; 1632 1633 static const struct bpf_func_proto * 1634 tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1635 { 1636 switch (func_id) { 1637 case BPF_FUNC_perf_event_output: 1638 return &bpf_perf_event_output_proto_tp; 1639 case BPF_FUNC_get_stackid: 1640 return &bpf_get_stackid_proto_tp; 1641 case BPF_FUNC_get_stack: 1642 return &bpf_get_stack_proto_tp; 1643 case BPF_FUNC_get_attach_cookie: 1644 return &bpf_get_attach_cookie_proto_trace; 1645 default: 1646 return bpf_tracing_func_proto(func_id, prog); 1647 } 1648 } 1649 1650 static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type, 1651 const struct bpf_prog *prog, 1652 struct bpf_insn_access_aux *info) 1653 { 1654 if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE) 1655 return false; 1656 if (type != BPF_READ) 1657 return false; 1658 if (off % size != 0) 1659 return false; 1660 1661 BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(__u64)); 1662 return true; 1663 } 1664 1665 const struct bpf_verifier_ops tracepoint_verifier_ops = { 1666 .get_func_proto = tp_prog_func_proto, 1667 .is_valid_access = tp_prog_is_valid_access, 1668 }; 1669 1670 const struct bpf_prog_ops tracepoint_prog_ops = { 1671 }; 1672 1673 BPF_CALL_3(bpf_perf_prog_read_value, struct bpf_perf_event_data_kern *, ctx, 1674 struct bpf_perf_event_value *, buf, u32, size) 1675 { 1676 int err = -EINVAL; 1677 1678 if (unlikely(size != sizeof(struct bpf_perf_event_value))) 1679 goto clear; 1680 err = perf_event_read_local(ctx->event, &buf->counter, &buf->enabled, 1681 &buf->running); 1682 if (unlikely(err)) 1683 goto clear; 1684 return 0; 1685 clear: 1686 memset(buf, 0, size); 1687 return err; 1688 } 1689 1690 static const struct bpf_func_proto bpf_perf_prog_read_value_proto = { 1691 .func = bpf_perf_prog_read_value, 1692 .gpl_only = true, 1693 .ret_type = RET_INTEGER, 1694 .arg1_type = ARG_PTR_TO_CTX, 1695 .arg2_type = ARG_PTR_TO_UNINIT_MEM, 1696 .arg3_type = ARG_CONST_SIZE, 1697 }; 1698 1699 BPF_CALL_4(bpf_read_branch_records, struct bpf_perf_event_data_kern *, ctx, 1700 void *, buf, u32, size, u64, flags) 1701 { 1702 static const u32 br_entry_size = sizeof(struct perf_branch_entry); 1703 struct perf_branch_stack *br_stack = ctx->data->br_stack; 1704 u32 to_copy; 1705 1706 if (unlikely(flags & ~BPF_F_GET_BRANCH_RECORDS_SIZE)) 1707 return -EINVAL; 1708 1709 if (unlikely(!(ctx->data->sample_flags & PERF_SAMPLE_BRANCH_STACK))) 1710 return -ENOENT; 1711 1712 if (unlikely(!br_stack)) 1713 return -ENOENT; 1714 1715 if (flags & BPF_F_GET_BRANCH_RECORDS_SIZE) 1716 return br_stack->nr * br_entry_size; 1717 1718 if (!buf || (size % br_entry_size != 0)) 1719 return -EINVAL; 1720 1721 to_copy = min_t(u32, br_stack->nr * br_entry_size, size); 1722 memcpy(buf, br_stack->entries, to_copy); 1723 1724 return to_copy; 1725 } 1726 1727 static const struct bpf_func_proto bpf_read_branch_records_proto = { 1728 .func = bpf_read_branch_records, 1729 .gpl_only = true, 1730 .ret_type = RET_INTEGER, 1731 .arg1_type = ARG_PTR_TO_CTX, 1732 .arg2_type = ARG_PTR_TO_MEM_OR_NULL, 1733 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1734 .arg4_type = ARG_ANYTHING, 1735 }; 1736 1737 static const struct bpf_func_proto * 1738 pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1739 { 1740 switch (func_id) { 1741 case BPF_FUNC_perf_event_output: 1742 return &bpf_perf_event_output_proto_tp; 1743 case BPF_FUNC_get_stackid: 1744 return &bpf_get_stackid_proto_pe; 1745 case BPF_FUNC_get_stack: 1746 return &bpf_get_stack_proto_pe; 1747 case BPF_FUNC_perf_prog_read_value: 1748 return &bpf_perf_prog_read_value_proto; 1749 case BPF_FUNC_read_branch_records: 1750 return &bpf_read_branch_records_proto; 1751 case BPF_FUNC_get_attach_cookie: 1752 return &bpf_get_attach_cookie_proto_pe; 1753 default: 1754 return bpf_tracing_func_proto(func_id, prog); 1755 } 1756 } 1757 1758 /* 1759 * bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp 1760 * to avoid potential recursive reuse issue when/if tracepoints are added 1761 * inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack. 1762 * 1763 * Since raw tracepoints run despite bpf_prog_active, support concurrent usage 1764 * in normal, irq, and nmi context. 1765 */ 1766 struct bpf_raw_tp_regs { 1767 struct pt_regs regs[3]; 1768 }; 1769 static DEFINE_PER_CPU(struct bpf_raw_tp_regs, bpf_raw_tp_regs); 1770 static DEFINE_PER_CPU(int, bpf_raw_tp_nest_level); 1771 static struct pt_regs *get_bpf_raw_tp_regs(void) 1772 { 1773 struct bpf_raw_tp_regs *tp_regs = this_cpu_ptr(&bpf_raw_tp_regs); 1774 int nest_level = this_cpu_inc_return(bpf_raw_tp_nest_level); 1775 1776 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(tp_regs->regs))) { 1777 this_cpu_dec(bpf_raw_tp_nest_level); 1778 return ERR_PTR(-EBUSY); 1779 } 1780 1781 return &tp_regs->regs[nest_level - 1]; 1782 } 1783 1784 static void put_bpf_raw_tp_regs(void) 1785 { 1786 this_cpu_dec(bpf_raw_tp_nest_level); 1787 } 1788 1789 BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args, 1790 struct bpf_map *, map, u64, flags, void *, data, u64, size) 1791 { 1792 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1793 int ret; 1794 1795 if (IS_ERR(regs)) 1796 return PTR_ERR(regs); 1797 1798 perf_fetch_caller_regs(regs); 1799 ret = ____bpf_perf_event_output(regs, map, flags, data, size); 1800 1801 put_bpf_raw_tp_regs(); 1802 return ret; 1803 } 1804 1805 static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = { 1806 .func = bpf_perf_event_output_raw_tp, 1807 .gpl_only = true, 1808 .ret_type = RET_INTEGER, 1809 .arg1_type = ARG_PTR_TO_CTX, 1810 .arg2_type = ARG_CONST_MAP_PTR, 1811 .arg3_type = ARG_ANYTHING, 1812 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1813 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 1814 }; 1815 1816 extern const struct bpf_func_proto bpf_skb_output_proto; 1817 extern const struct bpf_func_proto bpf_xdp_output_proto; 1818 extern const struct bpf_func_proto bpf_xdp_get_buff_len_trace_proto; 1819 1820 BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args, 1821 struct bpf_map *, map, u64, flags) 1822 { 1823 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1824 int ret; 1825 1826 if (IS_ERR(regs)) 1827 return PTR_ERR(regs); 1828 1829 perf_fetch_caller_regs(regs); 1830 /* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */ 1831 ret = bpf_get_stackid((unsigned long) regs, (unsigned long) map, 1832 flags, 0, 0); 1833 put_bpf_raw_tp_regs(); 1834 return ret; 1835 } 1836 1837 static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = { 1838 .func = bpf_get_stackid_raw_tp, 1839 .gpl_only = true, 1840 .ret_type = RET_INTEGER, 1841 .arg1_type = ARG_PTR_TO_CTX, 1842 .arg2_type = ARG_CONST_MAP_PTR, 1843 .arg3_type = ARG_ANYTHING, 1844 }; 1845 1846 BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args, 1847 void *, buf, u32, size, u64, flags) 1848 { 1849 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1850 int ret; 1851 1852 if (IS_ERR(regs)) 1853 return PTR_ERR(regs); 1854 1855 perf_fetch_caller_regs(regs); 1856 ret = bpf_get_stack((unsigned long) regs, (unsigned long) buf, 1857 (unsigned long) size, flags, 0); 1858 put_bpf_raw_tp_regs(); 1859 return ret; 1860 } 1861 1862 static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = { 1863 .func = bpf_get_stack_raw_tp, 1864 .gpl_only = true, 1865 .ret_type = RET_INTEGER, 1866 .arg1_type = ARG_PTR_TO_CTX, 1867 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1868 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1869 .arg4_type = ARG_ANYTHING, 1870 }; 1871 1872 static const struct bpf_func_proto * 1873 raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1874 { 1875 switch (func_id) { 1876 case BPF_FUNC_perf_event_output: 1877 return &bpf_perf_event_output_proto_raw_tp; 1878 case BPF_FUNC_get_stackid: 1879 return &bpf_get_stackid_proto_raw_tp; 1880 case BPF_FUNC_get_stack: 1881 return &bpf_get_stack_proto_raw_tp; 1882 default: 1883 return bpf_tracing_func_proto(func_id, prog); 1884 } 1885 } 1886 1887 const struct bpf_func_proto * 1888 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1889 { 1890 const struct bpf_func_proto *fn; 1891 1892 switch (func_id) { 1893 #ifdef CONFIG_NET 1894 case BPF_FUNC_skb_output: 1895 return &bpf_skb_output_proto; 1896 case BPF_FUNC_xdp_output: 1897 return &bpf_xdp_output_proto; 1898 case BPF_FUNC_skc_to_tcp6_sock: 1899 return &bpf_skc_to_tcp6_sock_proto; 1900 case BPF_FUNC_skc_to_tcp_sock: 1901 return &bpf_skc_to_tcp_sock_proto; 1902 case BPF_FUNC_skc_to_tcp_timewait_sock: 1903 return &bpf_skc_to_tcp_timewait_sock_proto; 1904 case BPF_FUNC_skc_to_tcp_request_sock: 1905 return &bpf_skc_to_tcp_request_sock_proto; 1906 case BPF_FUNC_skc_to_udp6_sock: 1907 return &bpf_skc_to_udp6_sock_proto; 1908 case BPF_FUNC_skc_to_unix_sock: 1909 return &bpf_skc_to_unix_sock_proto; 1910 case BPF_FUNC_skc_to_mptcp_sock: 1911 return &bpf_skc_to_mptcp_sock_proto; 1912 case BPF_FUNC_sk_storage_get: 1913 return &bpf_sk_storage_get_tracing_proto; 1914 case BPF_FUNC_sk_storage_delete: 1915 return &bpf_sk_storage_delete_tracing_proto; 1916 case BPF_FUNC_sock_from_file: 1917 return &bpf_sock_from_file_proto; 1918 case BPF_FUNC_get_socket_cookie: 1919 return &bpf_get_socket_ptr_cookie_proto; 1920 case BPF_FUNC_xdp_get_buff_len: 1921 return &bpf_xdp_get_buff_len_trace_proto; 1922 #endif 1923 case BPF_FUNC_seq_printf: 1924 return prog->expected_attach_type == BPF_TRACE_ITER ? 1925 &bpf_seq_printf_proto : 1926 NULL; 1927 case BPF_FUNC_seq_write: 1928 return prog->expected_attach_type == BPF_TRACE_ITER ? 1929 &bpf_seq_write_proto : 1930 NULL; 1931 case BPF_FUNC_seq_printf_btf: 1932 return prog->expected_attach_type == BPF_TRACE_ITER ? 1933 &bpf_seq_printf_btf_proto : 1934 NULL; 1935 case BPF_FUNC_d_path: 1936 return &bpf_d_path_proto; 1937 case BPF_FUNC_get_func_arg: 1938 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_proto : NULL; 1939 case BPF_FUNC_get_func_ret: 1940 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_ret_proto : NULL; 1941 case BPF_FUNC_get_func_arg_cnt: 1942 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_cnt_proto : NULL; 1943 case BPF_FUNC_get_attach_cookie: 1944 return bpf_prog_has_trampoline(prog) ? &bpf_get_attach_cookie_proto_tracing : NULL; 1945 default: 1946 fn = raw_tp_prog_func_proto(func_id, prog); 1947 if (!fn && prog->expected_attach_type == BPF_TRACE_ITER) 1948 fn = bpf_iter_get_func_proto(func_id, prog); 1949 return fn; 1950 } 1951 } 1952 1953 static bool raw_tp_prog_is_valid_access(int off, int size, 1954 enum bpf_access_type type, 1955 const struct bpf_prog *prog, 1956 struct bpf_insn_access_aux *info) 1957 { 1958 return bpf_tracing_ctx_access(off, size, type); 1959 } 1960 1961 static bool tracing_prog_is_valid_access(int off, int size, 1962 enum bpf_access_type type, 1963 const struct bpf_prog *prog, 1964 struct bpf_insn_access_aux *info) 1965 { 1966 return bpf_tracing_btf_ctx_access(off, size, type, prog, info); 1967 } 1968 1969 int __weak bpf_prog_test_run_tracing(struct bpf_prog *prog, 1970 const union bpf_attr *kattr, 1971 union bpf_attr __user *uattr) 1972 { 1973 return -ENOTSUPP; 1974 } 1975 1976 const struct bpf_verifier_ops raw_tracepoint_verifier_ops = { 1977 .get_func_proto = raw_tp_prog_func_proto, 1978 .is_valid_access = raw_tp_prog_is_valid_access, 1979 }; 1980 1981 const struct bpf_prog_ops raw_tracepoint_prog_ops = { 1982 #ifdef CONFIG_NET 1983 .test_run = bpf_prog_test_run_raw_tp, 1984 #endif 1985 }; 1986 1987 const struct bpf_verifier_ops tracing_verifier_ops = { 1988 .get_func_proto = tracing_prog_func_proto, 1989 .is_valid_access = tracing_prog_is_valid_access, 1990 }; 1991 1992 const struct bpf_prog_ops tracing_prog_ops = { 1993 .test_run = bpf_prog_test_run_tracing, 1994 }; 1995 1996 static bool raw_tp_writable_prog_is_valid_access(int off, int size, 1997 enum bpf_access_type type, 1998 const struct bpf_prog *prog, 1999 struct bpf_insn_access_aux *info) 2000 { 2001 if (off == 0) { 2002 if (size != sizeof(u64) || type != BPF_READ) 2003 return false; 2004 info->reg_type = PTR_TO_TP_BUFFER; 2005 } 2006 return raw_tp_prog_is_valid_access(off, size, type, prog, info); 2007 } 2008 2009 const struct bpf_verifier_ops raw_tracepoint_writable_verifier_ops = { 2010 .get_func_proto = raw_tp_prog_func_proto, 2011 .is_valid_access = raw_tp_writable_prog_is_valid_access, 2012 }; 2013 2014 const struct bpf_prog_ops raw_tracepoint_writable_prog_ops = { 2015 }; 2016 2017 static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type, 2018 const struct bpf_prog *prog, 2019 struct bpf_insn_access_aux *info) 2020 { 2021 const int size_u64 = sizeof(u64); 2022 2023 if (off < 0 || off >= sizeof(struct bpf_perf_event_data)) 2024 return false; 2025 if (type != BPF_READ) 2026 return false; 2027 if (off % size != 0) { 2028 if (sizeof(unsigned long) != 4) 2029 return false; 2030 if (size != 8) 2031 return false; 2032 if (off % size != 4) 2033 return false; 2034 } 2035 2036 switch (off) { 2037 case bpf_ctx_range(struct bpf_perf_event_data, sample_period): 2038 bpf_ctx_record_field_size(info, size_u64); 2039 if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) 2040 return false; 2041 break; 2042 case bpf_ctx_range(struct bpf_perf_event_data, addr): 2043 bpf_ctx_record_field_size(info, size_u64); 2044 if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) 2045 return false; 2046 break; 2047 default: 2048 if (size != sizeof(long)) 2049 return false; 2050 } 2051 2052 return true; 2053 } 2054 2055 static u32 pe_prog_convert_ctx_access(enum bpf_access_type type, 2056 const struct bpf_insn *si, 2057 struct bpf_insn *insn_buf, 2058 struct bpf_prog *prog, u32 *target_size) 2059 { 2060 struct bpf_insn *insn = insn_buf; 2061 2062 switch (si->off) { 2063 case offsetof(struct bpf_perf_event_data, sample_period): 2064 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 2065 data), si->dst_reg, si->src_reg, 2066 offsetof(struct bpf_perf_event_data_kern, data)); 2067 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, 2068 bpf_target_off(struct perf_sample_data, period, 8, 2069 target_size)); 2070 break; 2071 case offsetof(struct bpf_perf_event_data, addr): 2072 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 2073 data), si->dst_reg, si->src_reg, 2074 offsetof(struct bpf_perf_event_data_kern, data)); 2075 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, 2076 bpf_target_off(struct perf_sample_data, addr, 8, 2077 target_size)); 2078 break; 2079 default: 2080 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 2081 regs), si->dst_reg, si->src_reg, 2082 offsetof(struct bpf_perf_event_data_kern, regs)); 2083 *insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg, 2084 si->off); 2085 break; 2086 } 2087 2088 return insn - insn_buf; 2089 } 2090 2091 const struct bpf_verifier_ops perf_event_verifier_ops = { 2092 .get_func_proto = pe_prog_func_proto, 2093 .is_valid_access = pe_prog_is_valid_access, 2094 .convert_ctx_access = pe_prog_convert_ctx_access, 2095 }; 2096 2097 const struct bpf_prog_ops perf_event_prog_ops = { 2098 }; 2099 2100 static DEFINE_MUTEX(bpf_event_mutex); 2101 2102 #define BPF_TRACE_MAX_PROGS 64 2103 2104 int perf_event_attach_bpf_prog(struct perf_event *event, 2105 struct bpf_prog *prog, 2106 u64 bpf_cookie) 2107 { 2108 struct bpf_prog_array *old_array; 2109 struct bpf_prog_array *new_array; 2110 int ret = -EEXIST; 2111 2112 /* 2113 * Kprobe override only works if they are on the function entry, 2114 * and only if they are on the opt-in list. 2115 */ 2116 if (prog->kprobe_override && 2117 (!trace_kprobe_on_func_entry(event->tp_event) || 2118 !trace_kprobe_error_injectable(event->tp_event))) 2119 return -EINVAL; 2120 2121 mutex_lock(&bpf_event_mutex); 2122 2123 if (event->prog) 2124 goto unlock; 2125 2126 old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); 2127 if (old_array && 2128 bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) { 2129 ret = -E2BIG; 2130 goto unlock; 2131 } 2132 2133 ret = bpf_prog_array_copy(old_array, NULL, prog, bpf_cookie, &new_array); 2134 if (ret < 0) 2135 goto unlock; 2136 2137 /* set the new array to event->tp_event and set event->prog */ 2138 event->prog = prog; 2139 event->bpf_cookie = bpf_cookie; 2140 rcu_assign_pointer(event->tp_event->prog_array, new_array); 2141 bpf_prog_array_free_sleepable(old_array); 2142 2143 unlock: 2144 mutex_unlock(&bpf_event_mutex); 2145 return ret; 2146 } 2147 2148 void perf_event_detach_bpf_prog(struct perf_event *event) 2149 { 2150 struct bpf_prog_array *old_array; 2151 struct bpf_prog_array *new_array; 2152 int ret; 2153 2154 mutex_lock(&bpf_event_mutex); 2155 2156 if (!event->prog) 2157 goto unlock; 2158 2159 old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); 2160 ret = bpf_prog_array_copy(old_array, event->prog, NULL, 0, &new_array); 2161 if (ret == -ENOENT) 2162 goto unlock; 2163 if (ret < 0) { 2164 bpf_prog_array_delete_safe(old_array, event->prog); 2165 } else { 2166 rcu_assign_pointer(event->tp_event->prog_array, new_array); 2167 bpf_prog_array_free_sleepable(old_array); 2168 } 2169 2170 bpf_prog_put(event->prog); 2171 event->prog = NULL; 2172 2173 unlock: 2174 mutex_unlock(&bpf_event_mutex); 2175 } 2176 2177 int perf_event_query_prog_array(struct perf_event *event, void __user *info) 2178 { 2179 struct perf_event_query_bpf __user *uquery = info; 2180 struct perf_event_query_bpf query = {}; 2181 struct bpf_prog_array *progs; 2182 u32 *ids, prog_cnt, ids_len; 2183 int ret; 2184 2185 if (!perfmon_capable()) 2186 return -EPERM; 2187 if (event->attr.type != PERF_TYPE_TRACEPOINT) 2188 return -EINVAL; 2189 if (copy_from_user(&query, uquery, sizeof(query))) 2190 return -EFAULT; 2191 2192 ids_len = query.ids_len; 2193 if (ids_len > BPF_TRACE_MAX_PROGS) 2194 return -E2BIG; 2195 ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN); 2196 if (!ids) 2197 return -ENOMEM; 2198 /* 2199 * The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which 2200 * is required when user only wants to check for uquery->prog_cnt. 2201 * There is no need to check for it since the case is handled 2202 * gracefully in bpf_prog_array_copy_info. 2203 */ 2204 2205 mutex_lock(&bpf_event_mutex); 2206 progs = bpf_event_rcu_dereference(event->tp_event->prog_array); 2207 ret = bpf_prog_array_copy_info(progs, ids, ids_len, &prog_cnt); 2208 mutex_unlock(&bpf_event_mutex); 2209 2210 if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) || 2211 copy_to_user(uquery->ids, ids, ids_len * sizeof(u32))) 2212 ret = -EFAULT; 2213 2214 kfree(ids); 2215 return ret; 2216 } 2217 2218 extern struct bpf_raw_event_map __start__bpf_raw_tp[]; 2219 extern struct bpf_raw_event_map __stop__bpf_raw_tp[]; 2220 2221 struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name) 2222 { 2223 struct bpf_raw_event_map *btp = __start__bpf_raw_tp; 2224 2225 for (; btp < __stop__bpf_raw_tp; btp++) { 2226 if (!strcmp(btp->tp->name, name)) 2227 return btp; 2228 } 2229 2230 return bpf_get_raw_tracepoint_module(name); 2231 } 2232 2233 void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp) 2234 { 2235 struct module *mod; 2236 2237 preempt_disable(); 2238 mod = __module_address((unsigned long)btp); 2239 module_put(mod); 2240 preempt_enable(); 2241 } 2242 2243 static __always_inline 2244 void __bpf_trace_run(struct bpf_prog *prog, u64 *args) 2245 { 2246 cant_sleep(); 2247 if (unlikely(this_cpu_inc_return(*(prog->active)) != 1)) { 2248 bpf_prog_inc_misses_counter(prog); 2249 goto out; 2250 } 2251 rcu_read_lock(); 2252 (void) bpf_prog_run(prog, args); 2253 rcu_read_unlock(); 2254 out: 2255 this_cpu_dec(*(prog->active)); 2256 } 2257 2258 #define UNPACK(...) __VA_ARGS__ 2259 #define REPEAT_1(FN, DL, X, ...) FN(X) 2260 #define REPEAT_2(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__) 2261 #define REPEAT_3(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_2(FN, DL, __VA_ARGS__) 2262 #define REPEAT_4(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_3(FN, DL, __VA_ARGS__) 2263 #define REPEAT_5(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_4(FN, DL, __VA_ARGS__) 2264 #define REPEAT_6(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_5(FN, DL, __VA_ARGS__) 2265 #define REPEAT_7(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_6(FN, DL, __VA_ARGS__) 2266 #define REPEAT_8(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_7(FN, DL, __VA_ARGS__) 2267 #define REPEAT_9(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_8(FN, DL, __VA_ARGS__) 2268 #define REPEAT_10(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_9(FN, DL, __VA_ARGS__) 2269 #define REPEAT_11(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_10(FN, DL, __VA_ARGS__) 2270 #define REPEAT_12(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_11(FN, DL, __VA_ARGS__) 2271 #define REPEAT(X, FN, DL, ...) REPEAT_##X(FN, DL, __VA_ARGS__) 2272 2273 #define SARG(X) u64 arg##X 2274 #define COPY(X) args[X] = arg##X 2275 2276 #define __DL_COM (,) 2277 #define __DL_SEM (;) 2278 2279 #define __SEQ_0_11 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 2280 2281 #define BPF_TRACE_DEFN_x(x) \ 2282 void bpf_trace_run##x(struct bpf_prog *prog, \ 2283 REPEAT(x, SARG, __DL_COM, __SEQ_0_11)) \ 2284 { \ 2285 u64 args[x]; \ 2286 REPEAT(x, COPY, __DL_SEM, __SEQ_0_11); \ 2287 __bpf_trace_run(prog, args); \ 2288 } \ 2289 EXPORT_SYMBOL_GPL(bpf_trace_run##x) 2290 BPF_TRACE_DEFN_x(1); 2291 BPF_TRACE_DEFN_x(2); 2292 BPF_TRACE_DEFN_x(3); 2293 BPF_TRACE_DEFN_x(4); 2294 BPF_TRACE_DEFN_x(5); 2295 BPF_TRACE_DEFN_x(6); 2296 BPF_TRACE_DEFN_x(7); 2297 BPF_TRACE_DEFN_x(8); 2298 BPF_TRACE_DEFN_x(9); 2299 BPF_TRACE_DEFN_x(10); 2300 BPF_TRACE_DEFN_x(11); 2301 BPF_TRACE_DEFN_x(12); 2302 2303 static int __bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog) 2304 { 2305 struct tracepoint *tp = btp->tp; 2306 2307 /* 2308 * check that program doesn't access arguments beyond what's 2309 * available in this tracepoint 2310 */ 2311 if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64)) 2312 return -EINVAL; 2313 2314 if (prog->aux->max_tp_access > btp->writable_size) 2315 return -EINVAL; 2316 2317 return tracepoint_probe_register_may_exist(tp, (void *)btp->bpf_func, 2318 prog); 2319 } 2320 2321 int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog) 2322 { 2323 return __bpf_probe_register(btp, prog); 2324 } 2325 2326 int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_prog *prog) 2327 { 2328 return tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, prog); 2329 } 2330 2331 int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id, 2332 u32 *fd_type, const char **buf, 2333 u64 *probe_offset, u64 *probe_addr) 2334 { 2335 bool is_tracepoint, is_syscall_tp; 2336 struct bpf_prog *prog; 2337 int flags, err = 0; 2338 2339 prog = event->prog; 2340 if (!prog) 2341 return -ENOENT; 2342 2343 /* not supporting BPF_PROG_TYPE_PERF_EVENT yet */ 2344 if (prog->type == BPF_PROG_TYPE_PERF_EVENT) 2345 return -EOPNOTSUPP; 2346 2347 *prog_id = prog->aux->id; 2348 flags = event->tp_event->flags; 2349 is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT; 2350 is_syscall_tp = is_syscall_trace_event(event->tp_event); 2351 2352 if (is_tracepoint || is_syscall_tp) { 2353 *buf = is_tracepoint ? event->tp_event->tp->name 2354 : event->tp_event->name; 2355 *fd_type = BPF_FD_TYPE_TRACEPOINT; 2356 *probe_offset = 0x0; 2357 *probe_addr = 0x0; 2358 } else { 2359 /* kprobe/uprobe */ 2360 err = -EOPNOTSUPP; 2361 #ifdef CONFIG_KPROBE_EVENTS 2362 if (flags & TRACE_EVENT_FL_KPROBE) 2363 err = bpf_get_kprobe_info(event, fd_type, buf, 2364 probe_offset, probe_addr, 2365 event->attr.type == PERF_TYPE_TRACEPOINT); 2366 #endif 2367 #ifdef CONFIG_UPROBE_EVENTS 2368 if (flags & TRACE_EVENT_FL_UPROBE) 2369 err = bpf_get_uprobe_info(event, fd_type, buf, 2370 probe_offset, 2371 event->attr.type == PERF_TYPE_TRACEPOINT); 2372 #endif 2373 } 2374 2375 return err; 2376 } 2377 2378 static int __init send_signal_irq_work_init(void) 2379 { 2380 int cpu; 2381 struct send_signal_irq_work *work; 2382 2383 for_each_possible_cpu(cpu) { 2384 work = per_cpu_ptr(&send_signal_work, cpu); 2385 init_irq_work(&work->irq_work, do_bpf_send_signal); 2386 } 2387 return 0; 2388 } 2389 2390 subsys_initcall(send_signal_irq_work_init); 2391 2392 #ifdef CONFIG_MODULES 2393 static int bpf_event_notify(struct notifier_block *nb, unsigned long op, 2394 void *module) 2395 { 2396 struct bpf_trace_module *btm, *tmp; 2397 struct module *mod = module; 2398 int ret = 0; 2399 2400 if (mod->num_bpf_raw_events == 0 || 2401 (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING)) 2402 goto out; 2403 2404 mutex_lock(&bpf_module_mutex); 2405 2406 switch (op) { 2407 case MODULE_STATE_COMING: 2408 btm = kzalloc(sizeof(*btm), GFP_KERNEL); 2409 if (btm) { 2410 btm->module = module; 2411 list_add(&btm->list, &bpf_trace_modules); 2412 } else { 2413 ret = -ENOMEM; 2414 } 2415 break; 2416 case MODULE_STATE_GOING: 2417 list_for_each_entry_safe(btm, tmp, &bpf_trace_modules, list) { 2418 if (btm->module == module) { 2419 list_del(&btm->list); 2420 kfree(btm); 2421 break; 2422 } 2423 } 2424 break; 2425 } 2426 2427 mutex_unlock(&bpf_module_mutex); 2428 2429 out: 2430 return notifier_from_errno(ret); 2431 } 2432 2433 static struct notifier_block bpf_module_nb = { 2434 .notifier_call = bpf_event_notify, 2435 }; 2436 2437 static int __init bpf_event_init(void) 2438 { 2439 register_module_notifier(&bpf_module_nb); 2440 return 0; 2441 } 2442 2443 fs_initcall(bpf_event_init); 2444 #endif /* CONFIG_MODULES */ 2445 2446 #ifdef CONFIG_FPROBE 2447 struct bpf_kprobe_multi_link { 2448 struct bpf_link link; 2449 struct fprobe fp; 2450 unsigned long *addrs; 2451 u64 *cookies; 2452 u32 cnt; 2453 }; 2454 2455 struct bpf_kprobe_multi_run_ctx { 2456 struct bpf_run_ctx run_ctx; 2457 struct bpf_kprobe_multi_link *link; 2458 unsigned long entry_ip; 2459 }; 2460 2461 struct user_syms { 2462 const char **syms; 2463 char *buf; 2464 }; 2465 2466 static int copy_user_syms(struct user_syms *us, unsigned long __user *usyms, u32 cnt) 2467 { 2468 unsigned long __user usymbol; 2469 const char **syms = NULL; 2470 char *buf = NULL, *p; 2471 int err = -ENOMEM; 2472 unsigned int i; 2473 2474 syms = kvmalloc_array(cnt, sizeof(*syms), GFP_KERNEL); 2475 if (!syms) 2476 goto error; 2477 2478 buf = kvmalloc_array(cnt, KSYM_NAME_LEN, GFP_KERNEL); 2479 if (!buf) 2480 goto error; 2481 2482 for (p = buf, i = 0; i < cnt; i++) { 2483 if (__get_user(usymbol, usyms + i)) { 2484 err = -EFAULT; 2485 goto error; 2486 } 2487 err = strncpy_from_user(p, (const char __user *) usymbol, KSYM_NAME_LEN); 2488 if (err == KSYM_NAME_LEN) 2489 err = -E2BIG; 2490 if (err < 0) 2491 goto error; 2492 syms[i] = p; 2493 p += err + 1; 2494 } 2495 2496 us->syms = syms; 2497 us->buf = buf; 2498 return 0; 2499 2500 error: 2501 if (err) { 2502 kvfree(syms); 2503 kvfree(buf); 2504 } 2505 return err; 2506 } 2507 2508 static void free_user_syms(struct user_syms *us) 2509 { 2510 kvfree(us->syms); 2511 kvfree(us->buf); 2512 } 2513 2514 static void bpf_kprobe_multi_link_release(struct bpf_link *link) 2515 { 2516 struct bpf_kprobe_multi_link *kmulti_link; 2517 2518 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); 2519 unregister_fprobe(&kmulti_link->fp); 2520 } 2521 2522 static void bpf_kprobe_multi_link_dealloc(struct bpf_link *link) 2523 { 2524 struct bpf_kprobe_multi_link *kmulti_link; 2525 2526 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); 2527 kvfree(kmulti_link->addrs); 2528 kvfree(kmulti_link->cookies); 2529 kfree(kmulti_link); 2530 } 2531 2532 static const struct bpf_link_ops bpf_kprobe_multi_link_lops = { 2533 .release = bpf_kprobe_multi_link_release, 2534 .dealloc = bpf_kprobe_multi_link_dealloc, 2535 }; 2536 2537 static void bpf_kprobe_multi_cookie_swap(void *a, void *b, int size, const void *priv) 2538 { 2539 const struct bpf_kprobe_multi_link *link = priv; 2540 unsigned long *addr_a = a, *addr_b = b; 2541 u64 *cookie_a, *cookie_b; 2542 2543 cookie_a = link->cookies + (addr_a - link->addrs); 2544 cookie_b = link->cookies + (addr_b - link->addrs); 2545 2546 /* swap addr_a/addr_b and cookie_a/cookie_b values */ 2547 swap(*addr_a, *addr_b); 2548 swap(*cookie_a, *cookie_b); 2549 } 2550 2551 static int __bpf_kprobe_multi_cookie_cmp(const void *a, const void *b) 2552 { 2553 const unsigned long *addr_a = a, *addr_b = b; 2554 2555 if (*addr_a == *addr_b) 2556 return 0; 2557 return *addr_a < *addr_b ? -1 : 1; 2558 } 2559 2560 static int bpf_kprobe_multi_cookie_cmp(const void *a, const void *b, const void *priv) 2561 { 2562 return __bpf_kprobe_multi_cookie_cmp(a, b); 2563 } 2564 2565 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx) 2566 { 2567 struct bpf_kprobe_multi_run_ctx *run_ctx; 2568 struct bpf_kprobe_multi_link *link; 2569 u64 *cookie, entry_ip; 2570 unsigned long *addr; 2571 2572 if (WARN_ON_ONCE(!ctx)) 2573 return 0; 2574 run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, run_ctx); 2575 link = run_ctx->link; 2576 if (!link->cookies) 2577 return 0; 2578 entry_ip = run_ctx->entry_ip; 2579 addr = bsearch(&entry_ip, link->addrs, link->cnt, sizeof(entry_ip), 2580 __bpf_kprobe_multi_cookie_cmp); 2581 if (!addr) 2582 return 0; 2583 cookie = link->cookies + (addr - link->addrs); 2584 return *cookie; 2585 } 2586 2587 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 2588 { 2589 struct bpf_kprobe_multi_run_ctx *run_ctx; 2590 2591 run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, run_ctx); 2592 return run_ctx->entry_ip; 2593 } 2594 2595 static int 2596 kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link, 2597 unsigned long entry_ip, struct pt_regs *regs) 2598 { 2599 struct bpf_kprobe_multi_run_ctx run_ctx = { 2600 .link = link, 2601 .entry_ip = entry_ip, 2602 }; 2603 struct bpf_run_ctx *old_run_ctx; 2604 int err; 2605 2606 if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) { 2607 err = 0; 2608 goto out; 2609 } 2610 2611 migrate_disable(); 2612 rcu_read_lock(); 2613 old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx); 2614 err = bpf_prog_run(link->link.prog, regs); 2615 bpf_reset_run_ctx(old_run_ctx); 2616 rcu_read_unlock(); 2617 migrate_enable(); 2618 2619 out: 2620 __this_cpu_dec(bpf_prog_active); 2621 return err; 2622 } 2623 2624 static void 2625 kprobe_multi_link_handler(struct fprobe *fp, unsigned long fentry_ip, 2626 struct pt_regs *regs) 2627 { 2628 struct bpf_kprobe_multi_link *link; 2629 2630 link = container_of(fp, struct bpf_kprobe_multi_link, fp); 2631 kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), regs); 2632 } 2633 2634 static int symbols_cmp_r(const void *a, const void *b, const void *priv) 2635 { 2636 const char **str_a = (const char **) a; 2637 const char **str_b = (const char **) b; 2638 2639 return strcmp(*str_a, *str_b); 2640 } 2641 2642 struct multi_symbols_sort { 2643 const char **funcs; 2644 u64 *cookies; 2645 }; 2646 2647 static void symbols_swap_r(void *a, void *b, int size, const void *priv) 2648 { 2649 const struct multi_symbols_sort *data = priv; 2650 const char **name_a = a, **name_b = b; 2651 2652 swap(*name_a, *name_b); 2653 2654 /* If defined, swap also related cookies. */ 2655 if (data->cookies) { 2656 u64 *cookie_a, *cookie_b; 2657 2658 cookie_a = data->cookies + (name_a - data->funcs); 2659 cookie_b = data->cookies + (name_b - data->funcs); 2660 swap(*cookie_a, *cookie_b); 2661 } 2662 } 2663 2664 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 2665 { 2666 struct bpf_kprobe_multi_link *link = NULL; 2667 struct bpf_link_primer link_primer; 2668 void __user *ucookies; 2669 unsigned long *addrs; 2670 u32 flags, cnt, size; 2671 void __user *uaddrs; 2672 u64 *cookies = NULL; 2673 void __user *usyms; 2674 int err; 2675 2676 /* no support for 32bit archs yet */ 2677 if (sizeof(u64) != sizeof(void *)) 2678 return -EOPNOTSUPP; 2679 2680 if (prog->expected_attach_type != BPF_TRACE_KPROBE_MULTI) 2681 return -EINVAL; 2682 2683 flags = attr->link_create.kprobe_multi.flags; 2684 if (flags & ~BPF_F_KPROBE_MULTI_RETURN) 2685 return -EINVAL; 2686 2687 uaddrs = u64_to_user_ptr(attr->link_create.kprobe_multi.addrs); 2688 usyms = u64_to_user_ptr(attr->link_create.kprobe_multi.syms); 2689 if (!!uaddrs == !!usyms) 2690 return -EINVAL; 2691 2692 cnt = attr->link_create.kprobe_multi.cnt; 2693 if (!cnt) 2694 return -EINVAL; 2695 2696 size = cnt * sizeof(*addrs); 2697 addrs = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL); 2698 if (!addrs) 2699 return -ENOMEM; 2700 2701 ucookies = u64_to_user_ptr(attr->link_create.kprobe_multi.cookies); 2702 if (ucookies) { 2703 cookies = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL); 2704 if (!cookies) { 2705 err = -ENOMEM; 2706 goto error; 2707 } 2708 if (copy_from_user(cookies, ucookies, size)) { 2709 err = -EFAULT; 2710 goto error; 2711 } 2712 } 2713 2714 if (uaddrs) { 2715 if (copy_from_user(addrs, uaddrs, size)) { 2716 err = -EFAULT; 2717 goto error; 2718 } 2719 } else { 2720 struct multi_symbols_sort data = { 2721 .cookies = cookies, 2722 }; 2723 struct user_syms us; 2724 2725 err = copy_user_syms(&us, usyms, cnt); 2726 if (err) 2727 goto error; 2728 2729 if (cookies) 2730 data.funcs = us.syms; 2731 2732 sort_r(us.syms, cnt, sizeof(*us.syms), symbols_cmp_r, 2733 symbols_swap_r, &data); 2734 2735 err = ftrace_lookup_symbols(us.syms, cnt, addrs); 2736 free_user_syms(&us); 2737 if (err) 2738 goto error; 2739 } 2740 2741 link = kzalloc(sizeof(*link), GFP_KERNEL); 2742 if (!link) { 2743 err = -ENOMEM; 2744 goto error; 2745 } 2746 2747 bpf_link_init(&link->link, BPF_LINK_TYPE_KPROBE_MULTI, 2748 &bpf_kprobe_multi_link_lops, prog); 2749 2750 err = bpf_link_prime(&link->link, &link_primer); 2751 if (err) 2752 goto error; 2753 2754 if (flags & BPF_F_KPROBE_MULTI_RETURN) 2755 link->fp.exit_handler = kprobe_multi_link_handler; 2756 else 2757 link->fp.entry_handler = kprobe_multi_link_handler; 2758 2759 link->addrs = addrs; 2760 link->cookies = cookies; 2761 link->cnt = cnt; 2762 2763 if (cookies) { 2764 /* 2765 * Sorting addresses will trigger sorting cookies as well 2766 * (check bpf_kprobe_multi_cookie_swap). This way we can 2767 * find cookie based on the address in bpf_get_attach_cookie 2768 * helper. 2769 */ 2770 sort_r(addrs, cnt, sizeof(*addrs), 2771 bpf_kprobe_multi_cookie_cmp, 2772 bpf_kprobe_multi_cookie_swap, 2773 link); 2774 } 2775 2776 err = register_fprobe_ips(&link->fp, addrs, cnt); 2777 if (err) { 2778 bpf_link_cleanup(&link_primer); 2779 return err; 2780 } 2781 2782 return bpf_link_settle(&link_primer); 2783 2784 error: 2785 kfree(link); 2786 kvfree(addrs); 2787 kvfree(cookies); 2788 return err; 2789 } 2790 #else /* !CONFIG_FPROBE */ 2791 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 2792 { 2793 return -EOPNOTSUPP; 2794 } 2795 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx) 2796 { 2797 return 0; 2798 } 2799 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 2800 { 2801 return 0; 2802 } 2803 #endif 2804