1 // SPDX-License-Identifier: GPL-2.0 2 /* Copyright (c) 2011-2015 PLUMgrid, http://plumgrid.com 3 * Copyright (c) 2016 Facebook 4 */ 5 #include <linux/kernel.h> 6 #include <linux/types.h> 7 #include <linux/slab.h> 8 #include <linux/bpf.h> 9 #include <linux/bpf_verifier.h> 10 #include <linux/bpf_perf_event.h> 11 #include <linux/btf.h> 12 #include <linux/filter.h> 13 #include <linux/uaccess.h> 14 #include <linux/ctype.h> 15 #include <linux/kprobes.h> 16 #include <linux/spinlock.h> 17 #include <linux/syscalls.h> 18 #include <linux/error-injection.h> 19 #include <linux/btf_ids.h> 20 #include <linux/bpf_lsm.h> 21 #include <linux/fprobe.h> 22 #include <linux/bsearch.h> 23 #include <linux/sort.h> 24 #include <linux/key.h> 25 #include <linux/verification.h> 26 #include <linux/namei.h> 27 28 #include <net/bpf_sk_storage.h> 29 30 #include <uapi/linux/bpf.h> 31 #include <uapi/linux/btf.h> 32 33 #include <asm/tlb.h> 34 35 #include "trace_probe.h" 36 #include "trace.h" 37 38 #define CREATE_TRACE_POINTS 39 #include "bpf_trace.h" 40 41 #define bpf_event_rcu_dereference(p) \ 42 rcu_dereference_protected(p, lockdep_is_held(&bpf_event_mutex)) 43 44 #define MAX_UPROBE_MULTI_CNT (1U << 20) 45 #define MAX_KPROBE_MULTI_CNT (1U << 20) 46 47 #ifdef CONFIG_MODULES 48 struct bpf_trace_module { 49 struct module *module; 50 struct list_head list; 51 }; 52 53 static LIST_HEAD(bpf_trace_modules); 54 static DEFINE_MUTEX(bpf_module_mutex); 55 56 static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name) 57 { 58 struct bpf_raw_event_map *btp, *ret = NULL; 59 struct bpf_trace_module *btm; 60 unsigned int i; 61 62 mutex_lock(&bpf_module_mutex); 63 list_for_each_entry(btm, &bpf_trace_modules, list) { 64 for (i = 0; i < btm->module->num_bpf_raw_events; ++i) { 65 btp = &btm->module->bpf_raw_events[i]; 66 if (!strcmp(btp->tp->name, name)) { 67 if (try_module_get(btm->module)) 68 ret = btp; 69 goto out; 70 } 71 } 72 } 73 out: 74 mutex_unlock(&bpf_module_mutex); 75 return ret; 76 } 77 #else 78 static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name) 79 { 80 return NULL; 81 } 82 #endif /* CONFIG_MODULES */ 83 84 u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); 85 u64 bpf_get_stack(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); 86 87 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size, 88 u64 flags, const struct btf **btf, 89 s32 *btf_id); 90 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx); 91 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx); 92 93 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx); 94 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx); 95 96 /** 97 * trace_call_bpf - invoke BPF program 98 * @call: tracepoint event 99 * @ctx: opaque context pointer 100 * 101 * kprobe handlers execute BPF programs via this helper. 102 * Can be used from static tracepoints in the future. 103 * 104 * Return: BPF programs always return an integer which is interpreted by 105 * kprobe handler as: 106 * 0 - return from kprobe (event is filtered out) 107 * 1 - store kprobe event into ring buffer 108 * Other values are reserved and currently alias to 1 109 */ 110 unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx) 111 { 112 unsigned int ret; 113 114 cant_sleep(); 115 116 if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) { 117 /* 118 * since some bpf program is already running on this cpu, 119 * don't call into another bpf program (same or different) 120 * and don't send kprobe event into ring-buffer, 121 * so return zero here 122 */ 123 rcu_read_lock(); 124 bpf_prog_inc_misses_counters(rcu_dereference(call->prog_array)); 125 rcu_read_unlock(); 126 ret = 0; 127 goto out; 128 } 129 130 /* 131 * Instead of moving rcu_read_lock/rcu_dereference/rcu_read_unlock 132 * to all call sites, we did a bpf_prog_array_valid() there to check 133 * whether call->prog_array is empty or not, which is 134 * a heuristic to speed up execution. 135 * 136 * If bpf_prog_array_valid() fetched prog_array was 137 * non-NULL, we go into trace_call_bpf() and do the actual 138 * proper rcu_dereference() under RCU lock. 139 * If it turns out that prog_array is NULL then, we bail out. 140 * For the opposite, if the bpf_prog_array_valid() fetched pointer 141 * was NULL, you'll skip the prog_array with the risk of missing 142 * out of events when it was updated in between this and the 143 * rcu_dereference() which is accepted risk. 144 */ 145 rcu_read_lock(); 146 ret = bpf_prog_run_array(rcu_dereference(call->prog_array), 147 ctx, bpf_prog_run); 148 rcu_read_unlock(); 149 150 out: 151 __this_cpu_dec(bpf_prog_active); 152 153 return ret; 154 } 155 156 #ifdef CONFIG_BPF_KPROBE_OVERRIDE 157 BPF_CALL_2(bpf_override_return, struct pt_regs *, regs, unsigned long, rc) 158 { 159 regs_set_return_value(regs, rc); 160 override_function_with_return(regs); 161 return 0; 162 } 163 164 static const struct bpf_func_proto bpf_override_return_proto = { 165 .func = bpf_override_return, 166 .gpl_only = true, 167 .ret_type = RET_INTEGER, 168 .arg1_type = ARG_PTR_TO_CTX, 169 .arg2_type = ARG_ANYTHING, 170 }; 171 #endif 172 173 static __always_inline int 174 bpf_probe_read_user_common(void *dst, u32 size, const void __user *unsafe_ptr) 175 { 176 int ret; 177 178 ret = copy_from_user_nofault(dst, unsafe_ptr, size); 179 if (unlikely(ret < 0)) 180 memset(dst, 0, size); 181 return ret; 182 } 183 184 BPF_CALL_3(bpf_probe_read_user, void *, dst, u32, size, 185 const void __user *, unsafe_ptr) 186 { 187 return bpf_probe_read_user_common(dst, size, unsafe_ptr); 188 } 189 190 const struct bpf_func_proto bpf_probe_read_user_proto = { 191 .func = bpf_probe_read_user, 192 .gpl_only = true, 193 .ret_type = RET_INTEGER, 194 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 195 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 196 .arg3_type = ARG_ANYTHING, 197 }; 198 199 static __always_inline int 200 bpf_probe_read_user_str_common(void *dst, u32 size, 201 const void __user *unsafe_ptr) 202 { 203 int ret; 204 205 /* 206 * NB: We rely on strncpy_from_user() not copying junk past the NUL 207 * terminator into `dst`. 208 * 209 * strncpy_from_user() does long-sized strides in the fast path. If the 210 * strncpy does not mask out the bytes after the NUL in `unsafe_ptr`, 211 * then there could be junk after the NUL in `dst`. If user takes `dst` 212 * and keys a hash map with it, then semantically identical strings can 213 * occupy multiple entries in the map. 214 */ 215 ret = strncpy_from_user_nofault(dst, unsafe_ptr, size); 216 if (unlikely(ret < 0)) 217 memset(dst, 0, size); 218 return ret; 219 } 220 221 BPF_CALL_3(bpf_probe_read_user_str, void *, dst, u32, size, 222 const void __user *, unsafe_ptr) 223 { 224 return bpf_probe_read_user_str_common(dst, size, unsafe_ptr); 225 } 226 227 const struct bpf_func_proto bpf_probe_read_user_str_proto = { 228 .func = bpf_probe_read_user_str, 229 .gpl_only = true, 230 .ret_type = RET_INTEGER, 231 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 232 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 233 .arg3_type = ARG_ANYTHING, 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 #define MAX_TRACE_PRINTK_VARARGS 3 361 #define BPF_TRACE_PRINTK_SIZE 1024 362 363 BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1, 364 u64, arg2, u64, arg3) 365 { 366 u64 args[MAX_TRACE_PRINTK_VARARGS] = { arg1, arg2, arg3 }; 367 struct bpf_bprintf_data data = { 368 .get_bin_args = true, 369 .get_buf = true, 370 }; 371 int ret; 372 373 ret = bpf_bprintf_prepare(fmt, fmt_size, args, 374 MAX_TRACE_PRINTK_VARARGS, &data); 375 if (ret < 0) 376 return ret; 377 378 ret = bstr_printf(data.buf, MAX_BPRINTF_BUF, fmt, data.bin_args); 379 380 trace_bpf_trace_printk(data.buf); 381 382 bpf_bprintf_cleanup(&data); 383 384 return ret; 385 } 386 387 static const struct bpf_func_proto bpf_trace_printk_proto = { 388 .func = bpf_trace_printk, 389 .gpl_only = true, 390 .ret_type = RET_INTEGER, 391 .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY, 392 .arg2_type = ARG_CONST_SIZE, 393 }; 394 395 static void __set_printk_clr_event(struct work_struct *work) 396 { 397 /* 398 * This program might be calling bpf_trace_printk, 399 * so enable the associated bpf_trace/bpf_trace_printk event. 400 * Repeat this each time as it is possible a user has 401 * disabled bpf_trace_printk events. By loading a program 402 * calling bpf_trace_printk() however the user has expressed 403 * the intent to see such events. 404 */ 405 if (trace_set_clr_event("bpf_trace", "bpf_trace_printk", 1)) 406 pr_warn_ratelimited("could not enable bpf_trace_printk events"); 407 } 408 static DECLARE_WORK(set_printk_work, __set_printk_clr_event); 409 410 const struct bpf_func_proto *bpf_get_trace_printk_proto(void) 411 { 412 schedule_work(&set_printk_work); 413 return &bpf_trace_printk_proto; 414 } 415 416 BPF_CALL_4(bpf_trace_vprintk, char *, fmt, u32, fmt_size, const void *, args, 417 u32, data_len) 418 { 419 struct bpf_bprintf_data data = { 420 .get_bin_args = true, 421 .get_buf = true, 422 }; 423 int ret, num_args; 424 425 if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 || 426 (data_len && !args)) 427 return -EINVAL; 428 num_args = data_len / 8; 429 430 ret = bpf_bprintf_prepare(fmt, fmt_size, args, num_args, &data); 431 if (ret < 0) 432 return ret; 433 434 ret = bstr_printf(data.buf, MAX_BPRINTF_BUF, fmt, data.bin_args); 435 436 trace_bpf_trace_printk(data.buf); 437 438 bpf_bprintf_cleanup(&data); 439 440 return ret; 441 } 442 443 static const struct bpf_func_proto bpf_trace_vprintk_proto = { 444 .func = bpf_trace_vprintk, 445 .gpl_only = true, 446 .ret_type = RET_INTEGER, 447 .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY, 448 .arg2_type = ARG_CONST_SIZE, 449 .arg3_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY, 450 .arg4_type = ARG_CONST_SIZE_OR_ZERO, 451 }; 452 453 const struct bpf_func_proto *bpf_get_trace_vprintk_proto(void) 454 { 455 schedule_work(&set_printk_work); 456 return &bpf_trace_vprintk_proto; 457 } 458 459 BPF_CALL_5(bpf_seq_printf, struct seq_file *, m, char *, fmt, u32, fmt_size, 460 const void *, args, u32, data_len) 461 { 462 struct bpf_bprintf_data data = { 463 .get_bin_args = true, 464 }; 465 int err, num_args; 466 467 if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 || 468 (data_len && !args)) 469 return -EINVAL; 470 num_args = data_len / 8; 471 472 err = bpf_bprintf_prepare(fmt, fmt_size, args, num_args, &data); 473 if (err < 0) 474 return err; 475 476 seq_bprintf(m, fmt, data.bin_args); 477 478 bpf_bprintf_cleanup(&data); 479 480 return seq_has_overflowed(m) ? -EOVERFLOW : 0; 481 } 482 483 BTF_ID_LIST_SINGLE(btf_seq_file_ids, struct, seq_file) 484 485 static const struct bpf_func_proto bpf_seq_printf_proto = { 486 .func = bpf_seq_printf, 487 .gpl_only = true, 488 .ret_type = RET_INTEGER, 489 .arg1_type = ARG_PTR_TO_BTF_ID, 490 .arg1_btf_id = &btf_seq_file_ids[0], 491 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 492 .arg3_type = ARG_CONST_SIZE, 493 .arg4_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY, 494 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 495 }; 496 497 BPF_CALL_3(bpf_seq_write, struct seq_file *, m, const void *, data, u32, len) 498 { 499 return seq_write(m, data, len) ? -EOVERFLOW : 0; 500 } 501 502 static const struct bpf_func_proto bpf_seq_write_proto = { 503 .func = bpf_seq_write, 504 .gpl_only = true, 505 .ret_type = RET_INTEGER, 506 .arg1_type = ARG_PTR_TO_BTF_ID, 507 .arg1_btf_id = &btf_seq_file_ids[0], 508 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 509 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 510 }; 511 512 BPF_CALL_4(bpf_seq_printf_btf, struct seq_file *, m, struct btf_ptr *, ptr, 513 u32, btf_ptr_size, u64, flags) 514 { 515 const struct btf *btf; 516 s32 btf_id; 517 int ret; 518 519 ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id); 520 if (ret) 521 return ret; 522 523 return btf_type_seq_show_flags(btf, btf_id, ptr->ptr, m, flags); 524 } 525 526 static const struct bpf_func_proto bpf_seq_printf_btf_proto = { 527 .func = bpf_seq_printf_btf, 528 .gpl_only = true, 529 .ret_type = RET_INTEGER, 530 .arg1_type = ARG_PTR_TO_BTF_ID, 531 .arg1_btf_id = &btf_seq_file_ids[0], 532 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 533 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 534 .arg4_type = ARG_ANYTHING, 535 }; 536 537 static __always_inline int 538 get_map_perf_counter(struct bpf_map *map, u64 flags, 539 u64 *value, u64 *enabled, u64 *running) 540 { 541 struct bpf_array *array = container_of(map, struct bpf_array, map); 542 unsigned int cpu = smp_processor_id(); 543 u64 index = flags & BPF_F_INDEX_MASK; 544 struct bpf_event_entry *ee; 545 546 if (unlikely(flags & ~(BPF_F_INDEX_MASK))) 547 return -EINVAL; 548 if (index == BPF_F_CURRENT_CPU) 549 index = cpu; 550 if (unlikely(index >= array->map.max_entries)) 551 return -E2BIG; 552 553 ee = READ_ONCE(array->ptrs[index]); 554 if (!ee) 555 return -ENOENT; 556 557 return perf_event_read_local(ee->event, value, enabled, running); 558 } 559 560 BPF_CALL_2(bpf_perf_event_read, struct bpf_map *, map, u64, flags) 561 { 562 u64 value = 0; 563 int err; 564 565 err = get_map_perf_counter(map, flags, &value, NULL, NULL); 566 /* 567 * this api is ugly since we miss [-22..-2] range of valid 568 * counter values, but that's uapi 569 */ 570 if (err) 571 return err; 572 return value; 573 } 574 575 static const struct bpf_func_proto bpf_perf_event_read_proto = { 576 .func = bpf_perf_event_read, 577 .gpl_only = true, 578 .ret_type = RET_INTEGER, 579 .arg1_type = ARG_CONST_MAP_PTR, 580 .arg2_type = ARG_ANYTHING, 581 }; 582 583 BPF_CALL_4(bpf_perf_event_read_value, struct bpf_map *, map, u64, flags, 584 struct bpf_perf_event_value *, buf, u32, size) 585 { 586 int err = -EINVAL; 587 588 if (unlikely(size != sizeof(struct bpf_perf_event_value))) 589 goto clear; 590 err = get_map_perf_counter(map, flags, &buf->counter, &buf->enabled, 591 &buf->running); 592 if (unlikely(err)) 593 goto clear; 594 return 0; 595 clear: 596 memset(buf, 0, size); 597 return err; 598 } 599 600 static const struct bpf_func_proto bpf_perf_event_read_value_proto = { 601 .func = bpf_perf_event_read_value, 602 .gpl_only = true, 603 .ret_type = RET_INTEGER, 604 .arg1_type = ARG_CONST_MAP_PTR, 605 .arg2_type = ARG_ANYTHING, 606 .arg3_type = ARG_PTR_TO_UNINIT_MEM, 607 .arg4_type = ARG_CONST_SIZE, 608 }; 609 610 const struct bpf_func_proto *bpf_get_perf_event_read_value_proto(void) 611 { 612 return &bpf_perf_event_read_value_proto; 613 } 614 615 static __always_inline u64 616 __bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map, 617 u64 flags, struct perf_raw_record *raw, 618 struct perf_sample_data *sd) 619 { 620 struct bpf_array *array = container_of(map, struct bpf_array, map); 621 unsigned int cpu = smp_processor_id(); 622 u64 index = flags & BPF_F_INDEX_MASK; 623 struct bpf_event_entry *ee; 624 struct perf_event *event; 625 626 if (index == BPF_F_CURRENT_CPU) 627 index = cpu; 628 if (unlikely(index >= array->map.max_entries)) 629 return -E2BIG; 630 631 ee = READ_ONCE(array->ptrs[index]); 632 if (!ee) 633 return -ENOENT; 634 635 event = ee->event; 636 if (unlikely(event->attr.type != PERF_TYPE_SOFTWARE || 637 event->attr.config != PERF_COUNT_SW_BPF_OUTPUT)) 638 return -EINVAL; 639 640 if (unlikely(event->oncpu != cpu)) 641 return -EOPNOTSUPP; 642 643 perf_sample_save_raw_data(sd, event, raw); 644 645 return perf_event_output(event, sd, regs); 646 } 647 648 /* 649 * Support executing tracepoints in normal, irq, and nmi context that each call 650 * bpf_perf_event_output 651 */ 652 struct bpf_trace_sample_data { 653 struct perf_sample_data sds[3]; 654 }; 655 656 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_trace_sds); 657 static DEFINE_PER_CPU(int, bpf_trace_nest_level); 658 BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map, 659 u64, flags, void *, data, u64, size) 660 { 661 struct bpf_trace_sample_data *sds; 662 struct perf_raw_record raw = { 663 .frag = { 664 .size = size, 665 .data = data, 666 }, 667 }; 668 struct perf_sample_data *sd; 669 int nest_level, err; 670 671 preempt_disable(); 672 sds = this_cpu_ptr(&bpf_trace_sds); 673 nest_level = this_cpu_inc_return(bpf_trace_nest_level); 674 675 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(sds->sds))) { 676 err = -EBUSY; 677 goto out; 678 } 679 680 sd = &sds->sds[nest_level - 1]; 681 682 if (unlikely(flags & ~(BPF_F_INDEX_MASK))) { 683 err = -EINVAL; 684 goto out; 685 } 686 687 perf_sample_data_init(sd, 0, 0); 688 689 err = __bpf_perf_event_output(regs, map, flags, &raw, sd); 690 out: 691 this_cpu_dec(bpf_trace_nest_level); 692 preempt_enable(); 693 return err; 694 } 695 696 static const struct bpf_func_proto bpf_perf_event_output_proto = { 697 .func = bpf_perf_event_output, 698 .gpl_only = true, 699 .ret_type = RET_INTEGER, 700 .arg1_type = ARG_PTR_TO_CTX, 701 .arg2_type = ARG_CONST_MAP_PTR, 702 .arg3_type = ARG_ANYTHING, 703 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, 704 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 705 }; 706 707 static DEFINE_PER_CPU(int, bpf_event_output_nest_level); 708 struct bpf_nested_pt_regs { 709 struct pt_regs regs[3]; 710 }; 711 static DEFINE_PER_CPU(struct bpf_nested_pt_regs, bpf_pt_regs); 712 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_misc_sds); 713 714 u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size, 715 void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy) 716 { 717 struct perf_raw_frag frag = { 718 .copy = ctx_copy, 719 .size = ctx_size, 720 .data = ctx, 721 }; 722 struct perf_raw_record raw = { 723 .frag = { 724 { 725 .next = ctx_size ? &frag : NULL, 726 }, 727 .size = meta_size, 728 .data = meta, 729 }, 730 }; 731 struct perf_sample_data *sd; 732 struct pt_regs *regs; 733 int nest_level; 734 u64 ret; 735 736 preempt_disable(); 737 nest_level = this_cpu_inc_return(bpf_event_output_nest_level); 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); 748 749 ret = __bpf_perf_event_output(regs, map, flags, &raw, sd); 750 out: 751 this_cpu_dec(bpf_event_output_nest_level); 752 preempt_enable(); 753 return ret; 754 } 755 756 BPF_CALL_0(bpf_get_current_task) 757 { 758 return (long) current; 759 } 760 761 const struct bpf_func_proto bpf_get_current_task_proto = { 762 .func = bpf_get_current_task, 763 .gpl_only = true, 764 .ret_type = RET_INTEGER, 765 }; 766 767 BPF_CALL_0(bpf_get_current_task_btf) 768 { 769 return (unsigned long) current; 770 } 771 772 const struct bpf_func_proto bpf_get_current_task_btf_proto = { 773 .func = bpf_get_current_task_btf, 774 .gpl_only = true, 775 .ret_type = RET_PTR_TO_BTF_ID_TRUSTED, 776 .ret_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK], 777 }; 778 779 BPF_CALL_1(bpf_task_pt_regs, struct task_struct *, task) 780 { 781 return (unsigned long) task_pt_regs(task); 782 } 783 784 BTF_ID_LIST(bpf_task_pt_regs_ids) 785 BTF_ID(struct, pt_regs) 786 787 const struct bpf_func_proto bpf_task_pt_regs_proto = { 788 .func = bpf_task_pt_regs, 789 .gpl_only = true, 790 .arg1_type = ARG_PTR_TO_BTF_ID, 791 .arg1_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK], 792 .ret_type = RET_PTR_TO_BTF_ID, 793 .ret_btf_id = &bpf_task_pt_regs_ids[0], 794 }; 795 796 struct send_signal_irq_work { 797 struct irq_work irq_work; 798 struct task_struct *task; 799 u32 sig; 800 enum pid_type type; 801 bool has_siginfo; 802 struct kernel_siginfo info; 803 }; 804 805 static DEFINE_PER_CPU(struct send_signal_irq_work, send_signal_work); 806 807 static void do_bpf_send_signal(struct irq_work *entry) 808 { 809 struct send_signal_irq_work *work; 810 struct kernel_siginfo *siginfo; 811 812 work = container_of(entry, struct send_signal_irq_work, irq_work); 813 siginfo = work->has_siginfo ? &work->info : SEND_SIG_PRIV; 814 815 group_send_sig_info(work->sig, siginfo, work->task, work->type); 816 put_task_struct(work->task); 817 } 818 819 static int bpf_send_signal_common(u32 sig, enum pid_type type, struct task_struct *task, u64 value) 820 { 821 struct send_signal_irq_work *work = NULL; 822 struct kernel_siginfo info; 823 struct kernel_siginfo *siginfo; 824 825 if (!task) { 826 task = current; 827 siginfo = SEND_SIG_PRIV; 828 } else { 829 clear_siginfo(&info); 830 info.si_signo = sig; 831 info.si_errno = 0; 832 info.si_code = SI_KERNEL; 833 info.si_pid = 0; 834 info.si_uid = 0; 835 info.si_value.sival_ptr = (void *)(unsigned long)value; 836 siginfo = &info; 837 } 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(task->flags & (PF_KTHREAD | PF_EXITING))) 845 return -EPERM; 846 if (unlikely(!nmi_uaccess_okay())) 847 return -EPERM; 848 /* Task should not be pid=1 to avoid kernel panic. */ 849 if (unlikely(is_global_init(task))) 850 return -EPERM; 851 852 if (preempt_count() != 0 || irqs_disabled()) { 853 /* Do an early check on signal validity. Otherwise, 854 * the error is lost in deferred irq_work. 855 */ 856 if (unlikely(!valid_signal(sig))) 857 return -EINVAL; 858 859 work = this_cpu_ptr(&send_signal_work); 860 if (irq_work_is_busy(&work->irq_work)) 861 return -EBUSY; 862 863 /* Add the current task, which is the target of sending signal, 864 * to the irq_work. The current task may change when queued 865 * irq works get executed. 866 */ 867 work->task = get_task_struct(task); 868 work->has_siginfo = siginfo == &info; 869 if (work->has_siginfo) 870 copy_siginfo(&work->info, &info); 871 work->sig = sig; 872 work->type = type; 873 irq_work_queue(&work->irq_work); 874 return 0; 875 } 876 877 return group_send_sig_info(sig, siginfo, task, type); 878 } 879 880 BPF_CALL_1(bpf_send_signal, u32, sig) 881 { 882 return bpf_send_signal_common(sig, PIDTYPE_TGID, NULL, 0); 883 } 884 885 static const struct bpf_func_proto bpf_send_signal_proto = { 886 .func = bpf_send_signal, 887 .gpl_only = false, 888 .ret_type = RET_INTEGER, 889 .arg1_type = ARG_ANYTHING, 890 }; 891 892 BPF_CALL_1(bpf_send_signal_thread, u32, sig) 893 { 894 return bpf_send_signal_common(sig, PIDTYPE_PID, NULL, 0); 895 } 896 897 static const struct bpf_func_proto bpf_send_signal_thread_proto = { 898 .func = bpf_send_signal_thread, 899 .gpl_only = false, 900 .ret_type = RET_INTEGER, 901 .arg1_type = ARG_ANYTHING, 902 }; 903 904 BPF_CALL_3(bpf_d_path, struct path *, path, char *, buf, u32, sz) 905 { 906 struct path copy; 907 long len; 908 char *p; 909 910 if (!sz) 911 return 0; 912 913 /* 914 * The path pointer is verified as trusted and safe to use, 915 * but let's double check it's valid anyway to workaround 916 * potentially broken verifier. 917 */ 918 len = copy_from_kernel_nofault(©, path, sizeof(*path)); 919 if (len < 0) 920 return len; 921 922 p = d_path(©, buf, sz); 923 if (IS_ERR(p)) { 924 len = PTR_ERR(p); 925 } else { 926 len = buf + sz - p; 927 memmove(buf, p, len); 928 } 929 930 return len; 931 } 932 933 BTF_SET_START(btf_allowlist_d_path) 934 #ifdef CONFIG_SECURITY 935 BTF_ID(func, security_file_permission) 936 BTF_ID(func, security_inode_getattr) 937 BTF_ID(func, security_file_open) 938 #endif 939 #ifdef CONFIG_SECURITY_PATH 940 BTF_ID(func, security_path_truncate) 941 #endif 942 BTF_ID(func, vfs_truncate) 943 BTF_ID(func, vfs_fallocate) 944 BTF_ID(func, dentry_open) 945 BTF_ID(func, vfs_getattr) 946 BTF_ID(func, filp_close) 947 BTF_SET_END(btf_allowlist_d_path) 948 949 static bool bpf_d_path_allowed(const struct bpf_prog *prog) 950 { 951 if (prog->type == BPF_PROG_TYPE_TRACING && 952 prog->expected_attach_type == BPF_TRACE_ITER) 953 return true; 954 955 if (prog->type == BPF_PROG_TYPE_LSM) 956 return bpf_lsm_is_sleepable_hook(prog->aux->attach_btf_id); 957 958 return btf_id_set_contains(&btf_allowlist_d_path, 959 prog->aux->attach_btf_id); 960 } 961 962 BTF_ID_LIST_SINGLE(bpf_d_path_btf_ids, struct, path) 963 964 static const struct bpf_func_proto bpf_d_path_proto = { 965 .func = bpf_d_path, 966 .gpl_only = false, 967 .ret_type = RET_INTEGER, 968 .arg1_type = ARG_PTR_TO_BTF_ID, 969 .arg1_btf_id = &bpf_d_path_btf_ids[0], 970 .arg2_type = ARG_PTR_TO_MEM, 971 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 972 .allowed = bpf_d_path_allowed, 973 }; 974 975 #define BTF_F_ALL (BTF_F_COMPACT | BTF_F_NONAME | \ 976 BTF_F_PTR_RAW | BTF_F_ZERO) 977 978 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size, 979 u64 flags, const struct btf **btf, 980 s32 *btf_id) 981 { 982 const struct btf_type *t; 983 984 if (unlikely(flags & ~(BTF_F_ALL))) 985 return -EINVAL; 986 987 if (btf_ptr_size != sizeof(struct btf_ptr)) 988 return -EINVAL; 989 990 *btf = bpf_get_btf_vmlinux(); 991 992 if (IS_ERR_OR_NULL(*btf)) 993 return IS_ERR(*btf) ? PTR_ERR(*btf) : -EINVAL; 994 995 if (ptr->type_id > 0) 996 *btf_id = ptr->type_id; 997 else 998 return -EINVAL; 999 1000 if (*btf_id > 0) 1001 t = btf_type_by_id(*btf, *btf_id); 1002 if (*btf_id <= 0 || !t) 1003 return -ENOENT; 1004 1005 return 0; 1006 } 1007 1008 BPF_CALL_5(bpf_snprintf_btf, char *, str, u32, str_size, struct btf_ptr *, ptr, 1009 u32, btf_ptr_size, u64, flags) 1010 { 1011 const struct btf *btf; 1012 s32 btf_id; 1013 int ret; 1014 1015 ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id); 1016 if (ret) 1017 return ret; 1018 1019 return btf_type_snprintf_show(btf, btf_id, ptr->ptr, str, str_size, 1020 flags); 1021 } 1022 1023 const struct bpf_func_proto bpf_snprintf_btf_proto = { 1024 .func = bpf_snprintf_btf, 1025 .gpl_only = false, 1026 .ret_type = RET_INTEGER, 1027 .arg1_type = ARG_PTR_TO_MEM, 1028 .arg2_type = ARG_CONST_SIZE, 1029 .arg3_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1030 .arg4_type = ARG_CONST_SIZE, 1031 .arg5_type = ARG_ANYTHING, 1032 }; 1033 1034 BPF_CALL_1(bpf_get_func_ip_tracing, void *, ctx) 1035 { 1036 /* This helper call is inlined by verifier. */ 1037 return ((u64 *)ctx)[-2]; 1038 } 1039 1040 static const struct bpf_func_proto bpf_get_func_ip_proto_tracing = { 1041 .func = bpf_get_func_ip_tracing, 1042 .gpl_only = true, 1043 .ret_type = RET_INTEGER, 1044 .arg1_type = ARG_PTR_TO_CTX, 1045 }; 1046 1047 static inline unsigned long get_entry_ip(unsigned long fentry_ip) 1048 { 1049 #ifdef CONFIG_X86_KERNEL_IBT 1050 if (is_endbr((void *)(fentry_ip - ENDBR_INSN_SIZE))) 1051 fentry_ip -= ENDBR_INSN_SIZE; 1052 #endif 1053 return fentry_ip; 1054 } 1055 1056 BPF_CALL_1(bpf_get_func_ip_kprobe, struct pt_regs *, regs) 1057 { 1058 struct bpf_trace_run_ctx *run_ctx __maybe_unused; 1059 struct kprobe *kp; 1060 1061 #ifdef CONFIG_UPROBES 1062 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); 1063 if (run_ctx->is_uprobe) 1064 return ((struct uprobe_dispatch_data *)current->utask->vaddr)->bp_addr; 1065 #endif 1066 1067 kp = kprobe_running(); 1068 1069 if (!kp || !(kp->flags & KPROBE_FLAG_ON_FUNC_ENTRY)) 1070 return 0; 1071 1072 return get_entry_ip((uintptr_t)kp->addr); 1073 } 1074 1075 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe = { 1076 .func = bpf_get_func_ip_kprobe, 1077 .gpl_only = true, 1078 .ret_type = RET_INTEGER, 1079 .arg1_type = ARG_PTR_TO_CTX, 1080 }; 1081 1082 BPF_CALL_1(bpf_get_func_ip_kprobe_multi, struct pt_regs *, regs) 1083 { 1084 return bpf_kprobe_multi_entry_ip(current->bpf_ctx); 1085 } 1086 1087 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe_multi = { 1088 .func = bpf_get_func_ip_kprobe_multi, 1089 .gpl_only = false, 1090 .ret_type = RET_INTEGER, 1091 .arg1_type = ARG_PTR_TO_CTX, 1092 }; 1093 1094 BPF_CALL_1(bpf_get_attach_cookie_kprobe_multi, struct pt_regs *, regs) 1095 { 1096 return bpf_kprobe_multi_cookie(current->bpf_ctx); 1097 } 1098 1099 static const struct bpf_func_proto bpf_get_attach_cookie_proto_kmulti = { 1100 .func = bpf_get_attach_cookie_kprobe_multi, 1101 .gpl_only = false, 1102 .ret_type = RET_INTEGER, 1103 .arg1_type = ARG_PTR_TO_CTX, 1104 }; 1105 1106 BPF_CALL_1(bpf_get_func_ip_uprobe_multi, struct pt_regs *, regs) 1107 { 1108 return bpf_uprobe_multi_entry_ip(current->bpf_ctx); 1109 } 1110 1111 static const struct bpf_func_proto bpf_get_func_ip_proto_uprobe_multi = { 1112 .func = bpf_get_func_ip_uprobe_multi, 1113 .gpl_only = false, 1114 .ret_type = RET_INTEGER, 1115 .arg1_type = ARG_PTR_TO_CTX, 1116 }; 1117 1118 BPF_CALL_1(bpf_get_attach_cookie_uprobe_multi, struct pt_regs *, regs) 1119 { 1120 return bpf_uprobe_multi_cookie(current->bpf_ctx); 1121 } 1122 1123 static const struct bpf_func_proto bpf_get_attach_cookie_proto_umulti = { 1124 .func = bpf_get_attach_cookie_uprobe_multi, 1125 .gpl_only = false, 1126 .ret_type = RET_INTEGER, 1127 .arg1_type = ARG_PTR_TO_CTX, 1128 }; 1129 1130 BPF_CALL_1(bpf_get_attach_cookie_trace, void *, ctx) 1131 { 1132 struct bpf_trace_run_ctx *run_ctx; 1133 1134 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); 1135 return run_ctx->bpf_cookie; 1136 } 1137 1138 static const struct bpf_func_proto bpf_get_attach_cookie_proto_trace = { 1139 .func = bpf_get_attach_cookie_trace, 1140 .gpl_only = false, 1141 .ret_type = RET_INTEGER, 1142 .arg1_type = ARG_PTR_TO_CTX, 1143 }; 1144 1145 BPF_CALL_1(bpf_get_attach_cookie_pe, struct bpf_perf_event_data_kern *, ctx) 1146 { 1147 return ctx->event->bpf_cookie; 1148 } 1149 1150 static const struct bpf_func_proto bpf_get_attach_cookie_proto_pe = { 1151 .func = bpf_get_attach_cookie_pe, 1152 .gpl_only = false, 1153 .ret_type = RET_INTEGER, 1154 .arg1_type = ARG_PTR_TO_CTX, 1155 }; 1156 1157 BPF_CALL_1(bpf_get_attach_cookie_tracing, void *, ctx) 1158 { 1159 struct bpf_trace_run_ctx *run_ctx; 1160 1161 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); 1162 return run_ctx->bpf_cookie; 1163 } 1164 1165 static const struct bpf_func_proto bpf_get_attach_cookie_proto_tracing = { 1166 .func = bpf_get_attach_cookie_tracing, 1167 .gpl_only = false, 1168 .ret_type = RET_INTEGER, 1169 .arg1_type = ARG_PTR_TO_CTX, 1170 }; 1171 1172 BPF_CALL_3(bpf_get_branch_snapshot, void *, buf, u32, size, u64, flags) 1173 { 1174 static const u32 br_entry_size = sizeof(struct perf_branch_entry); 1175 u32 entry_cnt = size / br_entry_size; 1176 1177 entry_cnt = static_call(perf_snapshot_branch_stack)(buf, entry_cnt); 1178 1179 if (unlikely(flags)) 1180 return -EINVAL; 1181 1182 if (!entry_cnt) 1183 return -ENOENT; 1184 1185 return entry_cnt * br_entry_size; 1186 } 1187 1188 static const struct bpf_func_proto bpf_get_branch_snapshot_proto = { 1189 .func = bpf_get_branch_snapshot, 1190 .gpl_only = true, 1191 .ret_type = RET_INTEGER, 1192 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 1193 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 1194 }; 1195 1196 BPF_CALL_3(get_func_arg, void *, ctx, u32, n, u64 *, value) 1197 { 1198 /* This helper call is inlined by verifier. */ 1199 u64 nr_args = ((u64 *)ctx)[-1]; 1200 1201 if ((u64) n >= nr_args) 1202 return -EINVAL; 1203 *value = ((u64 *)ctx)[n]; 1204 return 0; 1205 } 1206 1207 static const struct bpf_func_proto bpf_get_func_arg_proto = { 1208 .func = get_func_arg, 1209 .ret_type = RET_INTEGER, 1210 .arg1_type = ARG_PTR_TO_CTX, 1211 .arg2_type = ARG_ANYTHING, 1212 .arg3_type = ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED, 1213 .arg3_size = sizeof(u64), 1214 }; 1215 1216 BPF_CALL_2(get_func_ret, void *, ctx, u64 *, value) 1217 { 1218 /* This helper call is inlined by verifier. */ 1219 u64 nr_args = ((u64 *)ctx)[-1]; 1220 1221 *value = ((u64 *)ctx)[nr_args]; 1222 return 0; 1223 } 1224 1225 static const struct bpf_func_proto bpf_get_func_ret_proto = { 1226 .func = get_func_ret, 1227 .ret_type = RET_INTEGER, 1228 .arg1_type = ARG_PTR_TO_CTX, 1229 .arg2_type = ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED, 1230 .arg2_size = sizeof(u64), 1231 }; 1232 1233 BPF_CALL_1(get_func_arg_cnt, void *, ctx) 1234 { 1235 /* This helper call is inlined by verifier. */ 1236 return ((u64 *)ctx)[-1]; 1237 } 1238 1239 static const struct bpf_func_proto bpf_get_func_arg_cnt_proto = { 1240 .func = get_func_arg_cnt, 1241 .ret_type = RET_INTEGER, 1242 .arg1_type = ARG_PTR_TO_CTX, 1243 }; 1244 1245 #ifdef CONFIG_KEYS 1246 __bpf_kfunc_start_defs(); 1247 1248 /** 1249 * bpf_lookup_user_key - lookup a key by its serial 1250 * @serial: key handle serial number 1251 * @flags: lookup-specific flags 1252 * 1253 * Search a key with a given *serial* and the provided *flags*. 1254 * If found, increment the reference count of the key by one, and 1255 * return it in the bpf_key structure. 1256 * 1257 * The bpf_key structure must be passed to bpf_key_put() when done 1258 * with it, so that the key reference count is decremented and the 1259 * bpf_key structure is freed. 1260 * 1261 * Permission checks are deferred to the time the key is used by 1262 * one of the available key-specific kfuncs. 1263 * 1264 * Set *flags* with KEY_LOOKUP_CREATE, to attempt creating a requested 1265 * special keyring (e.g. session keyring), if it doesn't yet exist. 1266 * Set *flags* with KEY_LOOKUP_PARTIAL, to lookup a key without waiting 1267 * for the key construction, and to retrieve uninstantiated keys (keys 1268 * without data attached to them). 1269 * 1270 * Return: a bpf_key pointer with a valid key pointer if the key is found, a 1271 * NULL pointer otherwise. 1272 */ 1273 __bpf_kfunc struct bpf_key *bpf_lookup_user_key(u32 serial, u64 flags) 1274 { 1275 key_ref_t key_ref; 1276 struct bpf_key *bkey; 1277 1278 if (flags & ~KEY_LOOKUP_ALL) 1279 return NULL; 1280 1281 /* 1282 * Permission check is deferred until the key is used, as the 1283 * intent of the caller is unknown here. 1284 */ 1285 key_ref = lookup_user_key(serial, flags, KEY_DEFER_PERM_CHECK); 1286 if (IS_ERR(key_ref)) 1287 return NULL; 1288 1289 bkey = kmalloc(sizeof(*bkey), GFP_KERNEL); 1290 if (!bkey) { 1291 key_put(key_ref_to_ptr(key_ref)); 1292 return NULL; 1293 } 1294 1295 bkey->key = key_ref_to_ptr(key_ref); 1296 bkey->has_ref = true; 1297 1298 return bkey; 1299 } 1300 1301 /** 1302 * bpf_lookup_system_key - lookup a key by a system-defined ID 1303 * @id: key ID 1304 * 1305 * Obtain a bpf_key structure with a key pointer set to the passed key ID. 1306 * The key pointer is marked as invalid, to prevent bpf_key_put() from 1307 * attempting to decrement the key reference count on that pointer. The key 1308 * pointer set in such way is currently understood only by 1309 * verify_pkcs7_signature(). 1310 * 1311 * Set *id* to one of the values defined in include/linux/verification.h: 1312 * 0 for the primary keyring (immutable keyring of system keys); 1313 * VERIFY_USE_SECONDARY_KEYRING for both the primary and secondary keyring 1314 * (where keys can be added only if they are vouched for by existing keys 1315 * in those keyrings); VERIFY_USE_PLATFORM_KEYRING for the platform 1316 * keyring (primarily used by the integrity subsystem to verify a kexec'ed 1317 * kerned image and, possibly, the initramfs signature). 1318 * 1319 * Return: a bpf_key pointer with an invalid key pointer set from the 1320 * pre-determined ID on success, a NULL pointer otherwise 1321 */ 1322 __bpf_kfunc struct bpf_key *bpf_lookup_system_key(u64 id) 1323 { 1324 struct bpf_key *bkey; 1325 1326 if (system_keyring_id_check(id) < 0) 1327 return NULL; 1328 1329 bkey = kmalloc(sizeof(*bkey), GFP_ATOMIC); 1330 if (!bkey) 1331 return NULL; 1332 1333 bkey->key = (struct key *)(unsigned long)id; 1334 bkey->has_ref = false; 1335 1336 return bkey; 1337 } 1338 1339 /** 1340 * bpf_key_put - decrement key reference count if key is valid and free bpf_key 1341 * @bkey: bpf_key structure 1342 * 1343 * Decrement the reference count of the key inside *bkey*, if the pointer 1344 * is valid, and free *bkey*. 1345 */ 1346 __bpf_kfunc void bpf_key_put(struct bpf_key *bkey) 1347 { 1348 if (bkey->has_ref) 1349 key_put(bkey->key); 1350 1351 kfree(bkey); 1352 } 1353 1354 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION 1355 /** 1356 * bpf_verify_pkcs7_signature - verify a PKCS#7 signature 1357 * @data_p: data to verify 1358 * @sig_p: signature of the data 1359 * @trusted_keyring: keyring with keys trusted for signature verification 1360 * 1361 * Verify the PKCS#7 signature *sig_ptr* against the supplied *data_ptr* 1362 * with keys in a keyring referenced by *trusted_keyring*. 1363 * 1364 * Return: 0 on success, a negative value on error. 1365 */ 1366 __bpf_kfunc int bpf_verify_pkcs7_signature(struct bpf_dynptr *data_p, 1367 struct bpf_dynptr *sig_p, 1368 struct bpf_key *trusted_keyring) 1369 { 1370 struct bpf_dynptr_kern *data_ptr = (struct bpf_dynptr_kern *)data_p; 1371 struct bpf_dynptr_kern *sig_ptr = (struct bpf_dynptr_kern *)sig_p; 1372 const void *data, *sig; 1373 u32 data_len, sig_len; 1374 int ret; 1375 1376 if (trusted_keyring->has_ref) { 1377 /* 1378 * Do the permission check deferred in bpf_lookup_user_key(). 1379 * See bpf_lookup_user_key() for more details. 1380 * 1381 * A call to key_task_permission() here would be redundant, as 1382 * it is already done by keyring_search() called by 1383 * find_asymmetric_key(). 1384 */ 1385 ret = key_validate(trusted_keyring->key); 1386 if (ret < 0) 1387 return ret; 1388 } 1389 1390 data_len = __bpf_dynptr_size(data_ptr); 1391 data = __bpf_dynptr_data(data_ptr, data_len); 1392 sig_len = __bpf_dynptr_size(sig_ptr); 1393 sig = __bpf_dynptr_data(sig_ptr, sig_len); 1394 1395 return verify_pkcs7_signature(data, data_len, sig, sig_len, 1396 trusted_keyring->key, 1397 VERIFYING_UNSPECIFIED_SIGNATURE, NULL, 1398 NULL); 1399 } 1400 #endif /* CONFIG_SYSTEM_DATA_VERIFICATION */ 1401 1402 __bpf_kfunc_end_defs(); 1403 1404 BTF_KFUNCS_START(key_sig_kfunc_set) 1405 BTF_ID_FLAGS(func, bpf_lookup_user_key, KF_ACQUIRE | KF_RET_NULL | KF_SLEEPABLE) 1406 BTF_ID_FLAGS(func, bpf_lookup_system_key, KF_ACQUIRE | KF_RET_NULL) 1407 BTF_ID_FLAGS(func, bpf_key_put, KF_RELEASE) 1408 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION 1409 BTF_ID_FLAGS(func, bpf_verify_pkcs7_signature, KF_SLEEPABLE) 1410 #endif 1411 BTF_KFUNCS_END(key_sig_kfunc_set) 1412 1413 static const struct btf_kfunc_id_set bpf_key_sig_kfunc_set = { 1414 .owner = THIS_MODULE, 1415 .set = &key_sig_kfunc_set, 1416 }; 1417 1418 static int __init bpf_key_sig_kfuncs_init(void) 1419 { 1420 return register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, 1421 &bpf_key_sig_kfunc_set); 1422 } 1423 1424 late_initcall(bpf_key_sig_kfuncs_init); 1425 #endif /* CONFIG_KEYS */ 1426 1427 static const struct bpf_func_proto * 1428 bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1429 { 1430 const struct bpf_func_proto *func_proto; 1431 1432 switch (func_id) { 1433 case BPF_FUNC_map_lookup_elem: 1434 return &bpf_map_lookup_elem_proto; 1435 case BPF_FUNC_map_update_elem: 1436 return &bpf_map_update_elem_proto; 1437 case BPF_FUNC_map_delete_elem: 1438 return &bpf_map_delete_elem_proto; 1439 case BPF_FUNC_map_push_elem: 1440 return &bpf_map_push_elem_proto; 1441 case BPF_FUNC_map_pop_elem: 1442 return &bpf_map_pop_elem_proto; 1443 case BPF_FUNC_map_peek_elem: 1444 return &bpf_map_peek_elem_proto; 1445 case BPF_FUNC_map_lookup_percpu_elem: 1446 return &bpf_map_lookup_percpu_elem_proto; 1447 case BPF_FUNC_ktime_get_ns: 1448 return &bpf_ktime_get_ns_proto; 1449 case BPF_FUNC_ktime_get_boot_ns: 1450 return &bpf_ktime_get_boot_ns_proto; 1451 case BPF_FUNC_tail_call: 1452 return &bpf_tail_call_proto; 1453 case BPF_FUNC_get_current_task: 1454 return &bpf_get_current_task_proto; 1455 case BPF_FUNC_get_current_task_btf: 1456 return &bpf_get_current_task_btf_proto; 1457 case BPF_FUNC_task_pt_regs: 1458 return &bpf_task_pt_regs_proto; 1459 case BPF_FUNC_get_current_uid_gid: 1460 return &bpf_get_current_uid_gid_proto; 1461 case BPF_FUNC_get_current_comm: 1462 return &bpf_get_current_comm_proto; 1463 case BPF_FUNC_trace_printk: 1464 return bpf_get_trace_printk_proto(); 1465 case BPF_FUNC_get_smp_processor_id: 1466 return &bpf_get_smp_processor_id_proto; 1467 case BPF_FUNC_get_numa_node_id: 1468 return &bpf_get_numa_node_id_proto; 1469 case BPF_FUNC_perf_event_read: 1470 return &bpf_perf_event_read_proto; 1471 case BPF_FUNC_get_prandom_u32: 1472 return &bpf_get_prandom_u32_proto; 1473 case BPF_FUNC_probe_read_user: 1474 return &bpf_probe_read_user_proto; 1475 case BPF_FUNC_probe_read_kernel: 1476 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1477 NULL : &bpf_probe_read_kernel_proto; 1478 case BPF_FUNC_probe_read_user_str: 1479 return &bpf_probe_read_user_str_proto; 1480 case BPF_FUNC_probe_read_kernel_str: 1481 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1482 NULL : &bpf_probe_read_kernel_str_proto; 1483 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 1484 case BPF_FUNC_probe_read: 1485 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1486 NULL : &bpf_probe_read_compat_proto; 1487 case BPF_FUNC_probe_read_str: 1488 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1489 NULL : &bpf_probe_read_compat_str_proto; 1490 #endif 1491 #ifdef CONFIG_CGROUPS 1492 case BPF_FUNC_cgrp_storage_get: 1493 return &bpf_cgrp_storage_get_proto; 1494 case BPF_FUNC_cgrp_storage_delete: 1495 return &bpf_cgrp_storage_delete_proto; 1496 case BPF_FUNC_current_task_under_cgroup: 1497 return &bpf_current_task_under_cgroup_proto; 1498 #endif 1499 case BPF_FUNC_send_signal: 1500 return &bpf_send_signal_proto; 1501 case BPF_FUNC_send_signal_thread: 1502 return &bpf_send_signal_thread_proto; 1503 case BPF_FUNC_perf_event_read_value: 1504 return &bpf_perf_event_read_value_proto; 1505 case BPF_FUNC_ringbuf_output: 1506 return &bpf_ringbuf_output_proto; 1507 case BPF_FUNC_ringbuf_reserve: 1508 return &bpf_ringbuf_reserve_proto; 1509 case BPF_FUNC_ringbuf_submit: 1510 return &bpf_ringbuf_submit_proto; 1511 case BPF_FUNC_ringbuf_discard: 1512 return &bpf_ringbuf_discard_proto; 1513 case BPF_FUNC_ringbuf_query: 1514 return &bpf_ringbuf_query_proto; 1515 case BPF_FUNC_jiffies64: 1516 return &bpf_jiffies64_proto; 1517 case BPF_FUNC_get_task_stack: 1518 return prog->sleepable ? &bpf_get_task_stack_sleepable_proto 1519 : &bpf_get_task_stack_proto; 1520 case BPF_FUNC_copy_from_user: 1521 return &bpf_copy_from_user_proto; 1522 case BPF_FUNC_copy_from_user_task: 1523 return &bpf_copy_from_user_task_proto; 1524 case BPF_FUNC_snprintf_btf: 1525 return &bpf_snprintf_btf_proto; 1526 case BPF_FUNC_per_cpu_ptr: 1527 return &bpf_per_cpu_ptr_proto; 1528 case BPF_FUNC_this_cpu_ptr: 1529 return &bpf_this_cpu_ptr_proto; 1530 case BPF_FUNC_task_storage_get: 1531 if (bpf_prog_check_recur(prog)) 1532 return &bpf_task_storage_get_recur_proto; 1533 return &bpf_task_storage_get_proto; 1534 case BPF_FUNC_task_storage_delete: 1535 if (bpf_prog_check_recur(prog)) 1536 return &bpf_task_storage_delete_recur_proto; 1537 return &bpf_task_storage_delete_proto; 1538 case BPF_FUNC_for_each_map_elem: 1539 return &bpf_for_each_map_elem_proto; 1540 case BPF_FUNC_snprintf: 1541 return &bpf_snprintf_proto; 1542 case BPF_FUNC_get_func_ip: 1543 return &bpf_get_func_ip_proto_tracing; 1544 case BPF_FUNC_get_branch_snapshot: 1545 return &bpf_get_branch_snapshot_proto; 1546 case BPF_FUNC_find_vma: 1547 return &bpf_find_vma_proto; 1548 case BPF_FUNC_trace_vprintk: 1549 return bpf_get_trace_vprintk_proto(); 1550 default: 1551 break; 1552 } 1553 1554 func_proto = bpf_base_func_proto(func_id, prog); 1555 if (func_proto) 1556 return func_proto; 1557 1558 if (!bpf_token_capable(prog->aux->token, CAP_SYS_ADMIN)) 1559 return NULL; 1560 1561 switch (func_id) { 1562 case BPF_FUNC_probe_write_user: 1563 return security_locked_down(LOCKDOWN_BPF_WRITE_USER) < 0 ? 1564 NULL : &bpf_probe_write_user_proto; 1565 default: 1566 return NULL; 1567 } 1568 } 1569 1570 static bool is_kprobe_multi(const struct bpf_prog *prog) 1571 { 1572 return prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI || 1573 prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION; 1574 } 1575 1576 static inline bool is_kprobe_session(const struct bpf_prog *prog) 1577 { 1578 return prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION; 1579 } 1580 1581 static inline bool is_uprobe_multi(const struct bpf_prog *prog) 1582 { 1583 return prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI || 1584 prog->expected_attach_type == BPF_TRACE_UPROBE_SESSION; 1585 } 1586 1587 static inline bool is_uprobe_session(const struct bpf_prog *prog) 1588 { 1589 return prog->expected_attach_type == BPF_TRACE_UPROBE_SESSION; 1590 } 1591 1592 static const struct bpf_func_proto * 1593 kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1594 { 1595 switch (func_id) { 1596 case BPF_FUNC_perf_event_output: 1597 return &bpf_perf_event_output_proto; 1598 case BPF_FUNC_get_stackid: 1599 return &bpf_get_stackid_proto; 1600 case BPF_FUNC_get_stack: 1601 return prog->sleepable ? &bpf_get_stack_sleepable_proto : &bpf_get_stack_proto; 1602 #ifdef CONFIG_BPF_KPROBE_OVERRIDE 1603 case BPF_FUNC_override_return: 1604 return &bpf_override_return_proto; 1605 #endif 1606 case BPF_FUNC_get_func_ip: 1607 if (is_kprobe_multi(prog)) 1608 return &bpf_get_func_ip_proto_kprobe_multi; 1609 if (is_uprobe_multi(prog)) 1610 return &bpf_get_func_ip_proto_uprobe_multi; 1611 return &bpf_get_func_ip_proto_kprobe; 1612 case BPF_FUNC_get_attach_cookie: 1613 if (is_kprobe_multi(prog)) 1614 return &bpf_get_attach_cookie_proto_kmulti; 1615 if (is_uprobe_multi(prog)) 1616 return &bpf_get_attach_cookie_proto_umulti; 1617 return &bpf_get_attach_cookie_proto_trace; 1618 default: 1619 return bpf_tracing_func_proto(func_id, prog); 1620 } 1621 } 1622 1623 /* bpf+kprobe programs can access fields of 'struct pt_regs' */ 1624 static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type, 1625 const struct bpf_prog *prog, 1626 struct bpf_insn_access_aux *info) 1627 { 1628 if (off < 0 || off >= sizeof(struct pt_regs)) 1629 return false; 1630 if (type != BPF_READ) 1631 return false; 1632 if (off % size != 0) 1633 return false; 1634 /* 1635 * Assertion for 32 bit to make sure last 8 byte access 1636 * (BPF_DW) to the last 4 byte member is disallowed. 1637 */ 1638 if (off + size > sizeof(struct pt_regs)) 1639 return false; 1640 1641 return true; 1642 } 1643 1644 const struct bpf_verifier_ops kprobe_verifier_ops = { 1645 .get_func_proto = kprobe_prog_func_proto, 1646 .is_valid_access = kprobe_prog_is_valid_access, 1647 }; 1648 1649 const struct bpf_prog_ops kprobe_prog_ops = { 1650 }; 1651 1652 BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map, 1653 u64, flags, void *, data, u64, size) 1654 { 1655 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1656 1657 /* 1658 * r1 points to perf tracepoint buffer where first 8 bytes are hidden 1659 * from bpf program and contain a pointer to 'struct pt_regs'. Fetch it 1660 * from there and call the same bpf_perf_event_output() helper inline. 1661 */ 1662 return ____bpf_perf_event_output(regs, map, flags, data, size); 1663 } 1664 1665 static const struct bpf_func_proto bpf_perf_event_output_proto_tp = { 1666 .func = bpf_perf_event_output_tp, 1667 .gpl_only = true, 1668 .ret_type = RET_INTEGER, 1669 .arg1_type = ARG_PTR_TO_CTX, 1670 .arg2_type = ARG_CONST_MAP_PTR, 1671 .arg3_type = ARG_ANYTHING, 1672 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1673 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 1674 }; 1675 1676 BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map, 1677 u64, flags) 1678 { 1679 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1680 1681 /* 1682 * Same comment as in bpf_perf_event_output_tp(), only that this time 1683 * the other helper's function body cannot be inlined due to being 1684 * external, thus we need to call raw helper function. 1685 */ 1686 return bpf_get_stackid((unsigned long) regs, (unsigned long) map, 1687 flags, 0, 0); 1688 } 1689 1690 static const struct bpf_func_proto bpf_get_stackid_proto_tp = { 1691 .func = bpf_get_stackid_tp, 1692 .gpl_only = true, 1693 .ret_type = RET_INTEGER, 1694 .arg1_type = ARG_PTR_TO_CTX, 1695 .arg2_type = ARG_CONST_MAP_PTR, 1696 .arg3_type = ARG_ANYTHING, 1697 }; 1698 1699 BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size, 1700 u64, flags) 1701 { 1702 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1703 1704 return bpf_get_stack((unsigned long) regs, (unsigned long) buf, 1705 (unsigned long) size, flags, 0); 1706 } 1707 1708 static const struct bpf_func_proto bpf_get_stack_proto_tp = { 1709 .func = bpf_get_stack_tp, 1710 .gpl_only = true, 1711 .ret_type = RET_INTEGER, 1712 .arg1_type = ARG_PTR_TO_CTX, 1713 .arg2_type = ARG_PTR_TO_UNINIT_MEM, 1714 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1715 .arg4_type = ARG_ANYTHING, 1716 }; 1717 1718 static const struct bpf_func_proto * 1719 tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1720 { 1721 switch (func_id) { 1722 case BPF_FUNC_perf_event_output: 1723 return &bpf_perf_event_output_proto_tp; 1724 case BPF_FUNC_get_stackid: 1725 return &bpf_get_stackid_proto_tp; 1726 case BPF_FUNC_get_stack: 1727 return &bpf_get_stack_proto_tp; 1728 case BPF_FUNC_get_attach_cookie: 1729 return &bpf_get_attach_cookie_proto_trace; 1730 default: 1731 return bpf_tracing_func_proto(func_id, prog); 1732 } 1733 } 1734 1735 static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type, 1736 const struct bpf_prog *prog, 1737 struct bpf_insn_access_aux *info) 1738 { 1739 if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE) 1740 return false; 1741 if (type != BPF_READ) 1742 return false; 1743 if (off % size != 0) 1744 return false; 1745 1746 BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(__u64)); 1747 return true; 1748 } 1749 1750 const struct bpf_verifier_ops tracepoint_verifier_ops = { 1751 .get_func_proto = tp_prog_func_proto, 1752 .is_valid_access = tp_prog_is_valid_access, 1753 }; 1754 1755 const struct bpf_prog_ops tracepoint_prog_ops = { 1756 }; 1757 1758 BPF_CALL_3(bpf_perf_prog_read_value, struct bpf_perf_event_data_kern *, ctx, 1759 struct bpf_perf_event_value *, buf, u32, size) 1760 { 1761 int err = -EINVAL; 1762 1763 if (unlikely(size != sizeof(struct bpf_perf_event_value))) 1764 goto clear; 1765 err = perf_event_read_local(ctx->event, &buf->counter, &buf->enabled, 1766 &buf->running); 1767 if (unlikely(err)) 1768 goto clear; 1769 return 0; 1770 clear: 1771 memset(buf, 0, size); 1772 return err; 1773 } 1774 1775 static const struct bpf_func_proto bpf_perf_prog_read_value_proto = { 1776 .func = bpf_perf_prog_read_value, 1777 .gpl_only = true, 1778 .ret_type = RET_INTEGER, 1779 .arg1_type = ARG_PTR_TO_CTX, 1780 .arg2_type = ARG_PTR_TO_UNINIT_MEM, 1781 .arg3_type = ARG_CONST_SIZE, 1782 }; 1783 1784 BPF_CALL_4(bpf_read_branch_records, struct bpf_perf_event_data_kern *, ctx, 1785 void *, buf, u32, size, u64, flags) 1786 { 1787 static const u32 br_entry_size = sizeof(struct perf_branch_entry); 1788 struct perf_branch_stack *br_stack = ctx->data->br_stack; 1789 u32 to_copy; 1790 1791 if (unlikely(flags & ~BPF_F_GET_BRANCH_RECORDS_SIZE)) 1792 return -EINVAL; 1793 1794 if (unlikely(!(ctx->data->sample_flags & PERF_SAMPLE_BRANCH_STACK))) 1795 return -ENOENT; 1796 1797 if (unlikely(!br_stack)) 1798 return -ENOENT; 1799 1800 if (flags & BPF_F_GET_BRANCH_RECORDS_SIZE) 1801 return br_stack->nr * br_entry_size; 1802 1803 if (!buf || (size % br_entry_size != 0)) 1804 return -EINVAL; 1805 1806 to_copy = min_t(u32, br_stack->nr * br_entry_size, size); 1807 memcpy(buf, br_stack->entries, to_copy); 1808 1809 return to_copy; 1810 } 1811 1812 static const struct bpf_func_proto bpf_read_branch_records_proto = { 1813 .func = bpf_read_branch_records, 1814 .gpl_only = true, 1815 .ret_type = RET_INTEGER, 1816 .arg1_type = ARG_PTR_TO_CTX, 1817 .arg2_type = ARG_PTR_TO_MEM_OR_NULL, 1818 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1819 .arg4_type = ARG_ANYTHING, 1820 }; 1821 1822 static const struct bpf_func_proto * 1823 pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1824 { 1825 switch (func_id) { 1826 case BPF_FUNC_perf_event_output: 1827 return &bpf_perf_event_output_proto_tp; 1828 case BPF_FUNC_get_stackid: 1829 return &bpf_get_stackid_proto_pe; 1830 case BPF_FUNC_get_stack: 1831 return &bpf_get_stack_proto_pe; 1832 case BPF_FUNC_perf_prog_read_value: 1833 return &bpf_perf_prog_read_value_proto; 1834 case BPF_FUNC_read_branch_records: 1835 return &bpf_read_branch_records_proto; 1836 case BPF_FUNC_get_attach_cookie: 1837 return &bpf_get_attach_cookie_proto_pe; 1838 default: 1839 return bpf_tracing_func_proto(func_id, prog); 1840 } 1841 } 1842 1843 /* 1844 * bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp 1845 * to avoid potential recursive reuse issue when/if tracepoints are added 1846 * inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack. 1847 * 1848 * Since raw tracepoints run despite bpf_prog_active, support concurrent usage 1849 * in normal, irq, and nmi context. 1850 */ 1851 struct bpf_raw_tp_regs { 1852 struct pt_regs regs[3]; 1853 }; 1854 static DEFINE_PER_CPU(struct bpf_raw_tp_regs, bpf_raw_tp_regs); 1855 static DEFINE_PER_CPU(int, bpf_raw_tp_nest_level); 1856 static struct pt_regs *get_bpf_raw_tp_regs(void) 1857 { 1858 struct bpf_raw_tp_regs *tp_regs = this_cpu_ptr(&bpf_raw_tp_regs); 1859 int nest_level = this_cpu_inc_return(bpf_raw_tp_nest_level); 1860 1861 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(tp_regs->regs))) { 1862 this_cpu_dec(bpf_raw_tp_nest_level); 1863 return ERR_PTR(-EBUSY); 1864 } 1865 1866 return &tp_regs->regs[nest_level - 1]; 1867 } 1868 1869 static void put_bpf_raw_tp_regs(void) 1870 { 1871 this_cpu_dec(bpf_raw_tp_nest_level); 1872 } 1873 1874 BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args, 1875 struct bpf_map *, map, u64, flags, void *, data, u64, size) 1876 { 1877 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1878 int ret; 1879 1880 if (IS_ERR(regs)) 1881 return PTR_ERR(regs); 1882 1883 perf_fetch_caller_regs(regs); 1884 ret = ____bpf_perf_event_output(regs, map, flags, data, size); 1885 1886 put_bpf_raw_tp_regs(); 1887 return ret; 1888 } 1889 1890 static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = { 1891 .func = bpf_perf_event_output_raw_tp, 1892 .gpl_only = true, 1893 .ret_type = RET_INTEGER, 1894 .arg1_type = ARG_PTR_TO_CTX, 1895 .arg2_type = ARG_CONST_MAP_PTR, 1896 .arg3_type = ARG_ANYTHING, 1897 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1898 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 1899 }; 1900 1901 extern const struct bpf_func_proto bpf_skb_output_proto; 1902 extern const struct bpf_func_proto bpf_xdp_output_proto; 1903 extern const struct bpf_func_proto bpf_xdp_get_buff_len_trace_proto; 1904 1905 BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args, 1906 struct bpf_map *, map, u64, flags) 1907 { 1908 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1909 int ret; 1910 1911 if (IS_ERR(regs)) 1912 return PTR_ERR(regs); 1913 1914 perf_fetch_caller_regs(regs); 1915 /* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */ 1916 ret = bpf_get_stackid((unsigned long) regs, (unsigned long) map, 1917 flags, 0, 0); 1918 put_bpf_raw_tp_regs(); 1919 return ret; 1920 } 1921 1922 static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = { 1923 .func = bpf_get_stackid_raw_tp, 1924 .gpl_only = true, 1925 .ret_type = RET_INTEGER, 1926 .arg1_type = ARG_PTR_TO_CTX, 1927 .arg2_type = ARG_CONST_MAP_PTR, 1928 .arg3_type = ARG_ANYTHING, 1929 }; 1930 1931 BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args, 1932 void *, buf, u32, size, u64, flags) 1933 { 1934 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1935 int ret; 1936 1937 if (IS_ERR(regs)) 1938 return PTR_ERR(regs); 1939 1940 perf_fetch_caller_regs(regs); 1941 ret = bpf_get_stack((unsigned long) regs, (unsigned long) buf, 1942 (unsigned long) size, flags, 0); 1943 put_bpf_raw_tp_regs(); 1944 return ret; 1945 } 1946 1947 static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = { 1948 .func = bpf_get_stack_raw_tp, 1949 .gpl_only = true, 1950 .ret_type = RET_INTEGER, 1951 .arg1_type = ARG_PTR_TO_CTX, 1952 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1953 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1954 .arg4_type = ARG_ANYTHING, 1955 }; 1956 1957 static const struct bpf_func_proto * 1958 raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1959 { 1960 switch (func_id) { 1961 case BPF_FUNC_perf_event_output: 1962 return &bpf_perf_event_output_proto_raw_tp; 1963 case BPF_FUNC_get_stackid: 1964 return &bpf_get_stackid_proto_raw_tp; 1965 case BPF_FUNC_get_stack: 1966 return &bpf_get_stack_proto_raw_tp; 1967 case BPF_FUNC_get_attach_cookie: 1968 return &bpf_get_attach_cookie_proto_tracing; 1969 default: 1970 return bpf_tracing_func_proto(func_id, prog); 1971 } 1972 } 1973 1974 const struct bpf_func_proto * 1975 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1976 { 1977 const struct bpf_func_proto *fn; 1978 1979 switch (func_id) { 1980 #ifdef CONFIG_NET 1981 case BPF_FUNC_skb_output: 1982 return &bpf_skb_output_proto; 1983 case BPF_FUNC_xdp_output: 1984 return &bpf_xdp_output_proto; 1985 case BPF_FUNC_skc_to_tcp6_sock: 1986 return &bpf_skc_to_tcp6_sock_proto; 1987 case BPF_FUNC_skc_to_tcp_sock: 1988 return &bpf_skc_to_tcp_sock_proto; 1989 case BPF_FUNC_skc_to_tcp_timewait_sock: 1990 return &bpf_skc_to_tcp_timewait_sock_proto; 1991 case BPF_FUNC_skc_to_tcp_request_sock: 1992 return &bpf_skc_to_tcp_request_sock_proto; 1993 case BPF_FUNC_skc_to_udp6_sock: 1994 return &bpf_skc_to_udp6_sock_proto; 1995 case BPF_FUNC_skc_to_unix_sock: 1996 return &bpf_skc_to_unix_sock_proto; 1997 case BPF_FUNC_skc_to_mptcp_sock: 1998 return &bpf_skc_to_mptcp_sock_proto; 1999 case BPF_FUNC_sk_storage_get: 2000 return &bpf_sk_storage_get_tracing_proto; 2001 case BPF_FUNC_sk_storage_delete: 2002 return &bpf_sk_storage_delete_tracing_proto; 2003 case BPF_FUNC_sock_from_file: 2004 return &bpf_sock_from_file_proto; 2005 case BPF_FUNC_get_socket_cookie: 2006 return &bpf_get_socket_ptr_cookie_proto; 2007 case BPF_FUNC_xdp_get_buff_len: 2008 return &bpf_xdp_get_buff_len_trace_proto; 2009 #endif 2010 case BPF_FUNC_seq_printf: 2011 return prog->expected_attach_type == BPF_TRACE_ITER ? 2012 &bpf_seq_printf_proto : 2013 NULL; 2014 case BPF_FUNC_seq_write: 2015 return prog->expected_attach_type == BPF_TRACE_ITER ? 2016 &bpf_seq_write_proto : 2017 NULL; 2018 case BPF_FUNC_seq_printf_btf: 2019 return prog->expected_attach_type == BPF_TRACE_ITER ? 2020 &bpf_seq_printf_btf_proto : 2021 NULL; 2022 case BPF_FUNC_d_path: 2023 return &bpf_d_path_proto; 2024 case BPF_FUNC_get_func_arg: 2025 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_proto : NULL; 2026 case BPF_FUNC_get_func_ret: 2027 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_ret_proto : NULL; 2028 case BPF_FUNC_get_func_arg_cnt: 2029 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_cnt_proto : NULL; 2030 case BPF_FUNC_get_attach_cookie: 2031 if (prog->type == BPF_PROG_TYPE_TRACING && 2032 prog->expected_attach_type == BPF_TRACE_RAW_TP) 2033 return &bpf_get_attach_cookie_proto_tracing; 2034 return bpf_prog_has_trampoline(prog) ? &bpf_get_attach_cookie_proto_tracing : NULL; 2035 default: 2036 fn = raw_tp_prog_func_proto(func_id, prog); 2037 if (!fn && prog->expected_attach_type == BPF_TRACE_ITER) 2038 fn = bpf_iter_get_func_proto(func_id, prog); 2039 return fn; 2040 } 2041 } 2042 2043 static bool raw_tp_prog_is_valid_access(int off, int size, 2044 enum bpf_access_type type, 2045 const struct bpf_prog *prog, 2046 struct bpf_insn_access_aux *info) 2047 { 2048 return bpf_tracing_ctx_access(off, size, type); 2049 } 2050 2051 static bool tracing_prog_is_valid_access(int off, int size, 2052 enum bpf_access_type type, 2053 const struct bpf_prog *prog, 2054 struct bpf_insn_access_aux *info) 2055 { 2056 return bpf_tracing_btf_ctx_access(off, size, type, prog, info); 2057 } 2058 2059 int __weak bpf_prog_test_run_tracing(struct bpf_prog *prog, 2060 const union bpf_attr *kattr, 2061 union bpf_attr __user *uattr) 2062 { 2063 return -ENOTSUPP; 2064 } 2065 2066 const struct bpf_verifier_ops raw_tracepoint_verifier_ops = { 2067 .get_func_proto = raw_tp_prog_func_proto, 2068 .is_valid_access = raw_tp_prog_is_valid_access, 2069 }; 2070 2071 const struct bpf_prog_ops raw_tracepoint_prog_ops = { 2072 #ifdef CONFIG_NET 2073 .test_run = bpf_prog_test_run_raw_tp, 2074 #endif 2075 }; 2076 2077 const struct bpf_verifier_ops tracing_verifier_ops = { 2078 .get_func_proto = tracing_prog_func_proto, 2079 .is_valid_access = tracing_prog_is_valid_access, 2080 }; 2081 2082 const struct bpf_prog_ops tracing_prog_ops = { 2083 .test_run = bpf_prog_test_run_tracing, 2084 }; 2085 2086 static bool raw_tp_writable_prog_is_valid_access(int off, int size, 2087 enum bpf_access_type type, 2088 const struct bpf_prog *prog, 2089 struct bpf_insn_access_aux *info) 2090 { 2091 if (off == 0) { 2092 if (size != sizeof(u64) || type != BPF_READ) 2093 return false; 2094 info->reg_type = PTR_TO_TP_BUFFER; 2095 } 2096 return raw_tp_prog_is_valid_access(off, size, type, prog, info); 2097 } 2098 2099 const struct bpf_verifier_ops raw_tracepoint_writable_verifier_ops = { 2100 .get_func_proto = raw_tp_prog_func_proto, 2101 .is_valid_access = raw_tp_writable_prog_is_valid_access, 2102 }; 2103 2104 const struct bpf_prog_ops raw_tracepoint_writable_prog_ops = { 2105 }; 2106 2107 static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type, 2108 const struct bpf_prog *prog, 2109 struct bpf_insn_access_aux *info) 2110 { 2111 const int size_u64 = sizeof(u64); 2112 2113 if (off < 0 || off >= sizeof(struct bpf_perf_event_data)) 2114 return false; 2115 if (type != BPF_READ) 2116 return false; 2117 if (off % size != 0) { 2118 if (sizeof(unsigned long) != 4) 2119 return false; 2120 if (size != 8) 2121 return false; 2122 if (off % size != 4) 2123 return false; 2124 } 2125 2126 switch (off) { 2127 case bpf_ctx_range(struct bpf_perf_event_data, sample_period): 2128 bpf_ctx_record_field_size(info, size_u64); 2129 if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) 2130 return false; 2131 break; 2132 case bpf_ctx_range(struct bpf_perf_event_data, addr): 2133 bpf_ctx_record_field_size(info, size_u64); 2134 if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) 2135 return false; 2136 break; 2137 default: 2138 if (size != sizeof(long)) 2139 return false; 2140 } 2141 2142 return true; 2143 } 2144 2145 static u32 pe_prog_convert_ctx_access(enum bpf_access_type type, 2146 const struct bpf_insn *si, 2147 struct bpf_insn *insn_buf, 2148 struct bpf_prog *prog, u32 *target_size) 2149 { 2150 struct bpf_insn *insn = insn_buf; 2151 2152 switch (si->off) { 2153 case offsetof(struct bpf_perf_event_data, sample_period): 2154 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 2155 data), si->dst_reg, si->src_reg, 2156 offsetof(struct bpf_perf_event_data_kern, data)); 2157 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, 2158 bpf_target_off(struct perf_sample_data, period, 8, 2159 target_size)); 2160 break; 2161 case offsetof(struct bpf_perf_event_data, addr): 2162 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 2163 data), si->dst_reg, si->src_reg, 2164 offsetof(struct bpf_perf_event_data_kern, data)); 2165 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, 2166 bpf_target_off(struct perf_sample_data, addr, 8, 2167 target_size)); 2168 break; 2169 default: 2170 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 2171 regs), si->dst_reg, si->src_reg, 2172 offsetof(struct bpf_perf_event_data_kern, regs)); 2173 *insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg, 2174 si->off); 2175 break; 2176 } 2177 2178 return insn - insn_buf; 2179 } 2180 2181 const struct bpf_verifier_ops perf_event_verifier_ops = { 2182 .get_func_proto = pe_prog_func_proto, 2183 .is_valid_access = pe_prog_is_valid_access, 2184 .convert_ctx_access = pe_prog_convert_ctx_access, 2185 }; 2186 2187 const struct bpf_prog_ops perf_event_prog_ops = { 2188 }; 2189 2190 static DEFINE_MUTEX(bpf_event_mutex); 2191 2192 #define BPF_TRACE_MAX_PROGS 64 2193 2194 int perf_event_attach_bpf_prog(struct perf_event *event, 2195 struct bpf_prog *prog, 2196 u64 bpf_cookie) 2197 { 2198 struct bpf_prog_array *old_array; 2199 struct bpf_prog_array *new_array; 2200 int ret = -EEXIST; 2201 2202 /* 2203 * Kprobe override only works if they are on the function entry, 2204 * and only if they are on the opt-in list. 2205 */ 2206 if (prog->kprobe_override && 2207 (!trace_kprobe_on_func_entry(event->tp_event) || 2208 !trace_kprobe_error_injectable(event->tp_event))) 2209 return -EINVAL; 2210 2211 mutex_lock(&bpf_event_mutex); 2212 2213 if (event->prog) 2214 goto unlock; 2215 2216 old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); 2217 if (old_array && 2218 bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) { 2219 ret = -E2BIG; 2220 goto unlock; 2221 } 2222 2223 ret = bpf_prog_array_copy(old_array, NULL, prog, bpf_cookie, &new_array); 2224 if (ret < 0) 2225 goto unlock; 2226 2227 /* set the new array to event->tp_event and set event->prog */ 2228 event->prog = prog; 2229 event->bpf_cookie = bpf_cookie; 2230 rcu_assign_pointer(event->tp_event->prog_array, new_array); 2231 bpf_prog_array_free_sleepable(old_array); 2232 2233 unlock: 2234 mutex_unlock(&bpf_event_mutex); 2235 return ret; 2236 } 2237 2238 void perf_event_detach_bpf_prog(struct perf_event *event) 2239 { 2240 struct bpf_prog_array *old_array; 2241 struct bpf_prog_array *new_array; 2242 struct bpf_prog *prog = NULL; 2243 int ret; 2244 2245 mutex_lock(&bpf_event_mutex); 2246 2247 if (!event->prog) 2248 goto unlock; 2249 2250 old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); 2251 if (!old_array) 2252 goto put; 2253 2254 ret = bpf_prog_array_copy(old_array, event->prog, NULL, 0, &new_array); 2255 if (ret < 0) { 2256 bpf_prog_array_delete_safe(old_array, event->prog); 2257 } else { 2258 rcu_assign_pointer(event->tp_event->prog_array, new_array); 2259 bpf_prog_array_free_sleepable(old_array); 2260 } 2261 2262 put: 2263 prog = event->prog; 2264 event->prog = NULL; 2265 2266 unlock: 2267 mutex_unlock(&bpf_event_mutex); 2268 2269 if (prog) { 2270 /* 2271 * It could be that the bpf_prog is not sleepable (and will be freed 2272 * via normal RCU), but is called from a point that supports sleepable 2273 * programs and uses tasks-trace-RCU. 2274 */ 2275 synchronize_rcu_tasks_trace(); 2276 2277 bpf_prog_put(prog); 2278 } 2279 } 2280 2281 int perf_event_query_prog_array(struct perf_event *event, void __user *info) 2282 { 2283 struct perf_event_query_bpf __user *uquery = info; 2284 struct perf_event_query_bpf query = {}; 2285 struct bpf_prog_array *progs; 2286 u32 *ids, prog_cnt, ids_len; 2287 int ret; 2288 2289 if (!perfmon_capable()) 2290 return -EPERM; 2291 if (event->attr.type != PERF_TYPE_TRACEPOINT) 2292 return -EINVAL; 2293 if (copy_from_user(&query, uquery, sizeof(query))) 2294 return -EFAULT; 2295 2296 ids_len = query.ids_len; 2297 if (ids_len > BPF_TRACE_MAX_PROGS) 2298 return -E2BIG; 2299 ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN); 2300 if (!ids) 2301 return -ENOMEM; 2302 /* 2303 * The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which 2304 * is required when user only wants to check for uquery->prog_cnt. 2305 * There is no need to check for it since the case is handled 2306 * gracefully in bpf_prog_array_copy_info. 2307 */ 2308 2309 mutex_lock(&bpf_event_mutex); 2310 progs = bpf_event_rcu_dereference(event->tp_event->prog_array); 2311 ret = bpf_prog_array_copy_info(progs, ids, ids_len, &prog_cnt); 2312 mutex_unlock(&bpf_event_mutex); 2313 2314 if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) || 2315 copy_to_user(uquery->ids, ids, ids_len * sizeof(u32))) 2316 ret = -EFAULT; 2317 2318 kfree(ids); 2319 return ret; 2320 } 2321 2322 extern struct bpf_raw_event_map __start__bpf_raw_tp[]; 2323 extern struct bpf_raw_event_map __stop__bpf_raw_tp[]; 2324 2325 struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name) 2326 { 2327 struct bpf_raw_event_map *btp = __start__bpf_raw_tp; 2328 2329 for (; btp < __stop__bpf_raw_tp; btp++) { 2330 if (!strcmp(btp->tp->name, name)) 2331 return btp; 2332 } 2333 2334 return bpf_get_raw_tracepoint_module(name); 2335 } 2336 2337 void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp) 2338 { 2339 struct module *mod; 2340 2341 guard(rcu)(); 2342 mod = __module_address((unsigned long)btp); 2343 module_put(mod); 2344 } 2345 2346 static __always_inline 2347 void __bpf_trace_run(struct bpf_raw_tp_link *link, u64 *args) 2348 { 2349 struct bpf_prog *prog = link->link.prog; 2350 struct bpf_run_ctx *old_run_ctx; 2351 struct bpf_trace_run_ctx run_ctx; 2352 2353 cant_sleep(); 2354 if (unlikely(this_cpu_inc_return(*(prog->active)) != 1)) { 2355 bpf_prog_inc_misses_counter(prog); 2356 goto out; 2357 } 2358 2359 run_ctx.bpf_cookie = link->cookie; 2360 old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx); 2361 2362 rcu_read_lock(); 2363 (void) bpf_prog_run(prog, args); 2364 rcu_read_unlock(); 2365 2366 bpf_reset_run_ctx(old_run_ctx); 2367 out: 2368 this_cpu_dec(*(prog->active)); 2369 } 2370 2371 #define UNPACK(...) __VA_ARGS__ 2372 #define REPEAT_1(FN, DL, X, ...) FN(X) 2373 #define REPEAT_2(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__) 2374 #define REPEAT_3(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_2(FN, DL, __VA_ARGS__) 2375 #define REPEAT_4(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_3(FN, DL, __VA_ARGS__) 2376 #define REPEAT_5(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_4(FN, DL, __VA_ARGS__) 2377 #define REPEAT_6(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_5(FN, DL, __VA_ARGS__) 2378 #define REPEAT_7(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_6(FN, DL, __VA_ARGS__) 2379 #define REPEAT_8(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_7(FN, DL, __VA_ARGS__) 2380 #define REPEAT_9(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_8(FN, DL, __VA_ARGS__) 2381 #define REPEAT_10(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_9(FN, DL, __VA_ARGS__) 2382 #define REPEAT_11(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_10(FN, DL, __VA_ARGS__) 2383 #define REPEAT_12(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_11(FN, DL, __VA_ARGS__) 2384 #define REPEAT(X, FN, DL, ...) REPEAT_##X(FN, DL, __VA_ARGS__) 2385 2386 #define SARG(X) u64 arg##X 2387 #define COPY(X) args[X] = arg##X 2388 2389 #define __DL_COM (,) 2390 #define __DL_SEM (;) 2391 2392 #define __SEQ_0_11 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 2393 2394 #define BPF_TRACE_DEFN_x(x) \ 2395 void bpf_trace_run##x(struct bpf_raw_tp_link *link, \ 2396 REPEAT(x, SARG, __DL_COM, __SEQ_0_11)) \ 2397 { \ 2398 u64 args[x]; \ 2399 REPEAT(x, COPY, __DL_SEM, __SEQ_0_11); \ 2400 __bpf_trace_run(link, args); \ 2401 } \ 2402 EXPORT_SYMBOL_GPL(bpf_trace_run##x) 2403 BPF_TRACE_DEFN_x(1); 2404 BPF_TRACE_DEFN_x(2); 2405 BPF_TRACE_DEFN_x(3); 2406 BPF_TRACE_DEFN_x(4); 2407 BPF_TRACE_DEFN_x(5); 2408 BPF_TRACE_DEFN_x(6); 2409 BPF_TRACE_DEFN_x(7); 2410 BPF_TRACE_DEFN_x(8); 2411 BPF_TRACE_DEFN_x(9); 2412 BPF_TRACE_DEFN_x(10); 2413 BPF_TRACE_DEFN_x(11); 2414 BPF_TRACE_DEFN_x(12); 2415 2416 int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_raw_tp_link *link) 2417 { 2418 struct tracepoint *tp = btp->tp; 2419 struct bpf_prog *prog = link->link.prog; 2420 2421 /* 2422 * check that program doesn't access arguments beyond what's 2423 * available in this tracepoint 2424 */ 2425 if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64)) 2426 return -EINVAL; 2427 2428 if (prog->aux->max_tp_access > btp->writable_size) 2429 return -EINVAL; 2430 2431 return tracepoint_probe_register_may_exist(tp, (void *)btp->bpf_func, link); 2432 } 2433 2434 int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_raw_tp_link *link) 2435 { 2436 return tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, link); 2437 } 2438 2439 int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id, 2440 u32 *fd_type, const char **buf, 2441 u64 *probe_offset, u64 *probe_addr, 2442 unsigned long *missed) 2443 { 2444 bool is_tracepoint, is_syscall_tp; 2445 struct bpf_prog *prog; 2446 int flags, err = 0; 2447 2448 prog = event->prog; 2449 if (!prog) 2450 return -ENOENT; 2451 2452 /* not supporting BPF_PROG_TYPE_PERF_EVENT yet */ 2453 if (prog->type == BPF_PROG_TYPE_PERF_EVENT) 2454 return -EOPNOTSUPP; 2455 2456 *prog_id = prog->aux->id; 2457 flags = event->tp_event->flags; 2458 is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT; 2459 is_syscall_tp = is_syscall_trace_event(event->tp_event); 2460 2461 if (is_tracepoint || is_syscall_tp) { 2462 *buf = is_tracepoint ? event->tp_event->tp->name 2463 : event->tp_event->name; 2464 /* We allow NULL pointer for tracepoint */ 2465 if (fd_type) 2466 *fd_type = BPF_FD_TYPE_TRACEPOINT; 2467 if (probe_offset) 2468 *probe_offset = 0x0; 2469 if (probe_addr) 2470 *probe_addr = 0x0; 2471 } else { 2472 /* kprobe/uprobe */ 2473 err = -EOPNOTSUPP; 2474 #ifdef CONFIG_KPROBE_EVENTS 2475 if (flags & TRACE_EVENT_FL_KPROBE) 2476 err = bpf_get_kprobe_info(event, fd_type, buf, 2477 probe_offset, probe_addr, missed, 2478 event->attr.type == PERF_TYPE_TRACEPOINT); 2479 #endif 2480 #ifdef CONFIG_UPROBE_EVENTS 2481 if (flags & TRACE_EVENT_FL_UPROBE) 2482 err = bpf_get_uprobe_info(event, fd_type, buf, 2483 probe_offset, probe_addr, 2484 event->attr.type == PERF_TYPE_TRACEPOINT); 2485 #endif 2486 } 2487 2488 return err; 2489 } 2490 2491 static int __init send_signal_irq_work_init(void) 2492 { 2493 int cpu; 2494 struct send_signal_irq_work *work; 2495 2496 for_each_possible_cpu(cpu) { 2497 work = per_cpu_ptr(&send_signal_work, cpu); 2498 init_irq_work(&work->irq_work, do_bpf_send_signal); 2499 } 2500 return 0; 2501 } 2502 2503 subsys_initcall(send_signal_irq_work_init); 2504 2505 #ifdef CONFIG_MODULES 2506 static int bpf_event_notify(struct notifier_block *nb, unsigned long op, 2507 void *module) 2508 { 2509 struct bpf_trace_module *btm, *tmp; 2510 struct module *mod = module; 2511 int ret = 0; 2512 2513 if (mod->num_bpf_raw_events == 0 || 2514 (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING)) 2515 goto out; 2516 2517 mutex_lock(&bpf_module_mutex); 2518 2519 switch (op) { 2520 case MODULE_STATE_COMING: 2521 btm = kzalloc(sizeof(*btm), GFP_KERNEL); 2522 if (btm) { 2523 btm->module = module; 2524 list_add(&btm->list, &bpf_trace_modules); 2525 } else { 2526 ret = -ENOMEM; 2527 } 2528 break; 2529 case MODULE_STATE_GOING: 2530 list_for_each_entry_safe(btm, tmp, &bpf_trace_modules, list) { 2531 if (btm->module == module) { 2532 list_del(&btm->list); 2533 kfree(btm); 2534 break; 2535 } 2536 } 2537 break; 2538 } 2539 2540 mutex_unlock(&bpf_module_mutex); 2541 2542 out: 2543 return notifier_from_errno(ret); 2544 } 2545 2546 static struct notifier_block bpf_module_nb = { 2547 .notifier_call = bpf_event_notify, 2548 }; 2549 2550 static int __init bpf_event_init(void) 2551 { 2552 register_module_notifier(&bpf_module_nb); 2553 return 0; 2554 } 2555 2556 fs_initcall(bpf_event_init); 2557 #endif /* CONFIG_MODULES */ 2558 2559 struct bpf_session_run_ctx { 2560 struct bpf_run_ctx run_ctx; 2561 bool is_return; 2562 void *data; 2563 }; 2564 2565 #ifdef CONFIG_FPROBE 2566 struct bpf_kprobe_multi_link { 2567 struct bpf_link link; 2568 struct fprobe fp; 2569 unsigned long *addrs; 2570 u64 *cookies; 2571 u32 cnt; 2572 u32 mods_cnt; 2573 struct module **mods; 2574 u32 flags; 2575 }; 2576 2577 struct bpf_kprobe_multi_run_ctx { 2578 struct bpf_session_run_ctx session_ctx; 2579 struct bpf_kprobe_multi_link *link; 2580 unsigned long entry_ip; 2581 }; 2582 2583 struct user_syms { 2584 const char **syms; 2585 char *buf; 2586 }; 2587 2588 #ifndef CONFIG_HAVE_FTRACE_REGS_HAVING_PT_REGS 2589 static DEFINE_PER_CPU(struct pt_regs, bpf_kprobe_multi_pt_regs); 2590 #define bpf_kprobe_multi_pt_regs_ptr() this_cpu_ptr(&bpf_kprobe_multi_pt_regs) 2591 #else 2592 #define bpf_kprobe_multi_pt_regs_ptr() (NULL) 2593 #endif 2594 2595 static unsigned long ftrace_get_entry_ip(unsigned long fentry_ip) 2596 { 2597 unsigned long ip = ftrace_get_symaddr(fentry_ip); 2598 2599 return ip ? : fentry_ip; 2600 } 2601 2602 static int copy_user_syms(struct user_syms *us, unsigned long __user *usyms, u32 cnt) 2603 { 2604 unsigned long __user usymbol; 2605 const char **syms = NULL; 2606 char *buf = NULL, *p; 2607 int err = -ENOMEM; 2608 unsigned int i; 2609 2610 syms = kvmalloc_array(cnt, sizeof(*syms), GFP_KERNEL); 2611 if (!syms) 2612 goto error; 2613 2614 buf = kvmalloc_array(cnt, KSYM_NAME_LEN, GFP_KERNEL); 2615 if (!buf) 2616 goto error; 2617 2618 for (p = buf, i = 0; i < cnt; i++) { 2619 if (__get_user(usymbol, usyms + i)) { 2620 err = -EFAULT; 2621 goto error; 2622 } 2623 err = strncpy_from_user(p, (const char __user *) usymbol, KSYM_NAME_LEN); 2624 if (err == KSYM_NAME_LEN) 2625 err = -E2BIG; 2626 if (err < 0) 2627 goto error; 2628 syms[i] = p; 2629 p += err + 1; 2630 } 2631 2632 us->syms = syms; 2633 us->buf = buf; 2634 return 0; 2635 2636 error: 2637 if (err) { 2638 kvfree(syms); 2639 kvfree(buf); 2640 } 2641 return err; 2642 } 2643 2644 static void kprobe_multi_put_modules(struct module **mods, u32 cnt) 2645 { 2646 u32 i; 2647 2648 for (i = 0; i < cnt; i++) 2649 module_put(mods[i]); 2650 } 2651 2652 static void free_user_syms(struct user_syms *us) 2653 { 2654 kvfree(us->syms); 2655 kvfree(us->buf); 2656 } 2657 2658 static void bpf_kprobe_multi_link_release(struct bpf_link *link) 2659 { 2660 struct bpf_kprobe_multi_link *kmulti_link; 2661 2662 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); 2663 unregister_fprobe(&kmulti_link->fp); 2664 kprobe_multi_put_modules(kmulti_link->mods, kmulti_link->mods_cnt); 2665 } 2666 2667 static void bpf_kprobe_multi_link_dealloc(struct bpf_link *link) 2668 { 2669 struct bpf_kprobe_multi_link *kmulti_link; 2670 2671 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); 2672 kvfree(kmulti_link->addrs); 2673 kvfree(kmulti_link->cookies); 2674 kfree(kmulti_link->mods); 2675 kfree(kmulti_link); 2676 } 2677 2678 static int bpf_kprobe_multi_link_fill_link_info(const struct bpf_link *link, 2679 struct bpf_link_info *info) 2680 { 2681 u64 __user *ucookies = u64_to_user_ptr(info->kprobe_multi.cookies); 2682 u64 __user *uaddrs = u64_to_user_ptr(info->kprobe_multi.addrs); 2683 struct bpf_kprobe_multi_link *kmulti_link; 2684 u32 ucount = info->kprobe_multi.count; 2685 int err = 0, i; 2686 2687 if (!uaddrs ^ !ucount) 2688 return -EINVAL; 2689 if (ucookies && !ucount) 2690 return -EINVAL; 2691 2692 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); 2693 info->kprobe_multi.count = kmulti_link->cnt; 2694 info->kprobe_multi.flags = kmulti_link->flags; 2695 info->kprobe_multi.missed = kmulti_link->fp.nmissed; 2696 2697 if (!uaddrs) 2698 return 0; 2699 if (ucount < kmulti_link->cnt) 2700 err = -ENOSPC; 2701 else 2702 ucount = kmulti_link->cnt; 2703 2704 if (ucookies) { 2705 if (kmulti_link->cookies) { 2706 if (copy_to_user(ucookies, kmulti_link->cookies, ucount * sizeof(u64))) 2707 return -EFAULT; 2708 } else { 2709 for (i = 0; i < ucount; i++) { 2710 if (put_user(0, ucookies + i)) 2711 return -EFAULT; 2712 } 2713 } 2714 } 2715 2716 if (kallsyms_show_value(current_cred())) { 2717 if (copy_to_user(uaddrs, kmulti_link->addrs, ucount * sizeof(u64))) 2718 return -EFAULT; 2719 } else { 2720 for (i = 0; i < ucount; i++) { 2721 if (put_user(0, uaddrs + i)) 2722 return -EFAULT; 2723 } 2724 } 2725 return err; 2726 } 2727 2728 static const struct bpf_link_ops bpf_kprobe_multi_link_lops = { 2729 .release = bpf_kprobe_multi_link_release, 2730 .dealloc_deferred = bpf_kprobe_multi_link_dealloc, 2731 .fill_link_info = bpf_kprobe_multi_link_fill_link_info, 2732 }; 2733 2734 static void bpf_kprobe_multi_cookie_swap(void *a, void *b, int size, const void *priv) 2735 { 2736 const struct bpf_kprobe_multi_link *link = priv; 2737 unsigned long *addr_a = a, *addr_b = b; 2738 u64 *cookie_a, *cookie_b; 2739 2740 cookie_a = link->cookies + (addr_a - link->addrs); 2741 cookie_b = link->cookies + (addr_b - link->addrs); 2742 2743 /* swap addr_a/addr_b and cookie_a/cookie_b values */ 2744 swap(*addr_a, *addr_b); 2745 swap(*cookie_a, *cookie_b); 2746 } 2747 2748 static int bpf_kprobe_multi_addrs_cmp(const void *a, const void *b) 2749 { 2750 const unsigned long *addr_a = a, *addr_b = b; 2751 2752 if (*addr_a == *addr_b) 2753 return 0; 2754 return *addr_a < *addr_b ? -1 : 1; 2755 } 2756 2757 static int bpf_kprobe_multi_cookie_cmp(const void *a, const void *b, const void *priv) 2758 { 2759 return bpf_kprobe_multi_addrs_cmp(a, b); 2760 } 2761 2762 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx) 2763 { 2764 struct bpf_kprobe_multi_run_ctx *run_ctx; 2765 struct bpf_kprobe_multi_link *link; 2766 u64 *cookie, entry_ip; 2767 unsigned long *addr; 2768 2769 if (WARN_ON_ONCE(!ctx)) 2770 return 0; 2771 run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, 2772 session_ctx.run_ctx); 2773 link = run_ctx->link; 2774 if (!link->cookies) 2775 return 0; 2776 entry_ip = run_ctx->entry_ip; 2777 addr = bsearch(&entry_ip, link->addrs, link->cnt, sizeof(entry_ip), 2778 bpf_kprobe_multi_addrs_cmp); 2779 if (!addr) 2780 return 0; 2781 cookie = link->cookies + (addr - link->addrs); 2782 return *cookie; 2783 } 2784 2785 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 2786 { 2787 struct bpf_kprobe_multi_run_ctx *run_ctx; 2788 2789 run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, 2790 session_ctx.run_ctx); 2791 return run_ctx->entry_ip; 2792 } 2793 2794 static int 2795 kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link, 2796 unsigned long entry_ip, struct ftrace_regs *fregs, 2797 bool is_return, void *data) 2798 { 2799 struct bpf_kprobe_multi_run_ctx run_ctx = { 2800 .session_ctx = { 2801 .is_return = is_return, 2802 .data = data, 2803 }, 2804 .link = link, 2805 .entry_ip = entry_ip, 2806 }; 2807 struct bpf_run_ctx *old_run_ctx; 2808 struct pt_regs *regs; 2809 int err; 2810 2811 if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) { 2812 bpf_prog_inc_misses_counter(link->link.prog); 2813 err = 1; 2814 goto out; 2815 } 2816 2817 migrate_disable(); 2818 rcu_read_lock(); 2819 regs = ftrace_partial_regs(fregs, bpf_kprobe_multi_pt_regs_ptr()); 2820 old_run_ctx = bpf_set_run_ctx(&run_ctx.session_ctx.run_ctx); 2821 err = bpf_prog_run(link->link.prog, regs); 2822 bpf_reset_run_ctx(old_run_ctx); 2823 rcu_read_unlock(); 2824 migrate_enable(); 2825 2826 out: 2827 __this_cpu_dec(bpf_prog_active); 2828 return err; 2829 } 2830 2831 static int 2832 kprobe_multi_link_handler(struct fprobe *fp, unsigned long fentry_ip, 2833 unsigned long ret_ip, struct ftrace_regs *fregs, 2834 void *data) 2835 { 2836 struct bpf_kprobe_multi_link *link; 2837 int err; 2838 2839 link = container_of(fp, struct bpf_kprobe_multi_link, fp); 2840 err = kprobe_multi_link_prog_run(link, ftrace_get_entry_ip(fentry_ip), 2841 fregs, false, data); 2842 return is_kprobe_session(link->link.prog) ? err : 0; 2843 } 2844 2845 static void 2846 kprobe_multi_link_exit_handler(struct fprobe *fp, unsigned long fentry_ip, 2847 unsigned long ret_ip, struct ftrace_regs *fregs, 2848 void *data) 2849 { 2850 struct bpf_kprobe_multi_link *link; 2851 2852 link = container_of(fp, struct bpf_kprobe_multi_link, fp); 2853 kprobe_multi_link_prog_run(link, ftrace_get_entry_ip(fentry_ip), 2854 fregs, true, data); 2855 } 2856 2857 static int symbols_cmp_r(const void *a, const void *b, const void *priv) 2858 { 2859 const char **str_a = (const char **) a; 2860 const char **str_b = (const char **) b; 2861 2862 return strcmp(*str_a, *str_b); 2863 } 2864 2865 struct multi_symbols_sort { 2866 const char **funcs; 2867 u64 *cookies; 2868 }; 2869 2870 static void symbols_swap_r(void *a, void *b, int size, const void *priv) 2871 { 2872 const struct multi_symbols_sort *data = priv; 2873 const char **name_a = a, **name_b = b; 2874 2875 swap(*name_a, *name_b); 2876 2877 /* If defined, swap also related cookies. */ 2878 if (data->cookies) { 2879 u64 *cookie_a, *cookie_b; 2880 2881 cookie_a = data->cookies + (name_a - data->funcs); 2882 cookie_b = data->cookies + (name_b - data->funcs); 2883 swap(*cookie_a, *cookie_b); 2884 } 2885 } 2886 2887 struct modules_array { 2888 struct module **mods; 2889 int mods_cnt; 2890 int mods_cap; 2891 }; 2892 2893 static int add_module(struct modules_array *arr, struct module *mod) 2894 { 2895 struct module **mods; 2896 2897 if (arr->mods_cnt == arr->mods_cap) { 2898 arr->mods_cap = max(16, arr->mods_cap * 3 / 2); 2899 mods = krealloc_array(arr->mods, arr->mods_cap, sizeof(*mods), GFP_KERNEL); 2900 if (!mods) 2901 return -ENOMEM; 2902 arr->mods = mods; 2903 } 2904 2905 arr->mods[arr->mods_cnt] = mod; 2906 arr->mods_cnt++; 2907 return 0; 2908 } 2909 2910 static bool has_module(struct modules_array *arr, struct module *mod) 2911 { 2912 int i; 2913 2914 for (i = arr->mods_cnt - 1; i >= 0; i--) { 2915 if (arr->mods[i] == mod) 2916 return true; 2917 } 2918 return false; 2919 } 2920 2921 static int get_modules_for_addrs(struct module ***mods, unsigned long *addrs, u32 addrs_cnt) 2922 { 2923 struct modules_array arr = {}; 2924 u32 i, err = 0; 2925 2926 for (i = 0; i < addrs_cnt; i++) { 2927 bool skip_add = false; 2928 struct module *mod; 2929 2930 scoped_guard(rcu) { 2931 mod = __module_address(addrs[i]); 2932 /* Either no module or it's already stored */ 2933 if (!mod || has_module(&arr, mod)) { 2934 skip_add = true; 2935 break; /* scoped_guard */ 2936 } 2937 if (!try_module_get(mod)) 2938 err = -EINVAL; 2939 } 2940 if (skip_add) 2941 continue; 2942 if (err) 2943 break; 2944 err = add_module(&arr, mod); 2945 if (err) { 2946 module_put(mod); 2947 break; 2948 } 2949 } 2950 2951 /* We return either err < 0 in case of error, ... */ 2952 if (err) { 2953 kprobe_multi_put_modules(arr.mods, arr.mods_cnt); 2954 kfree(arr.mods); 2955 return err; 2956 } 2957 2958 /* or number of modules found if everything is ok. */ 2959 *mods = arr.mods; 2960 return arr.mods_cnt; 2961 } 2962 2963 static int addrs_check_error_injection_list(unsigned long *addrs, u32 cnt) 2964 { 2965 u32 i; 2966 2967 for (i = 0; i < cnt; i++) { 2968 if (!within_error_injection_list(addrs[i])) 2969 return -EINVAL; 2970 } 2971 return 0; 2972 } 2973 2974 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 2975 { 2976 struct bpf_kprobe_multi_link *link = NULL; 2977 struct bpf_link_primer link_primer; 2978 void __user *ucookies; 2979 unsigned long *addrs; 2980 u32 flags, cnt, size; 2981 void __user *uaddrs; 2982 u64 *cookies = NULL; 2983 void __user *usyms; 2984 int err; 2985 2986 /* no support for 32bit archs yet */ 2987 if (sizeof(u64) != sizeof(void *)) 2988 return -EOPNOTSUPP; 2989 2990 if (!is_kprobe_multi(prog)) 2991 return -EINVAL; 2992 2993 flags = attr->link_create.kprobe_multi.flags; 2994 if (flags & ~BPF_F_KPROBE_MULTI_RETURN) 2995 return -EINVAL; 2996 2997 uaddrs = u64_to_user_ptr(attr->link_create.kprobe_multi.addrs); 2998 usyms = u64_to_user_ptr(attr->link_create.kprobe_multi.syms); 2999 if (!!uaddrs == !!usyms) 3000 return -EINVAL; 3001 3002 cnt = attr->link_create.kprobe_multi.cnt; 3003 if (!cnt) 3004 return -EINVAL; 3005 if (cnt > MAX_KPROBE_MULTI_CNT) 3006 return -E2BIG; 3007 3008 size = cnt * sizeof(*addrs); 3009 addrs = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL); 3010 if (!addrs) 3011 return -ENOMEM; 3012 3013 ucookies = u64_to_user_ptr(attr->link_create.kprobe_multi.cookies); 3014 if (ucookies) { 3015 cookies = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL); 3016 if (!cookies) { 3017 err = -ENOMEM; 3018 goto error; 3019 } 3020 if (copy_from_user(cookies, ucookies, size)) { 3021 err = -EFAULT; 3022 goto error; 3023 } 3024 } 3025 3026 if (uaddrs) { 3027 if (copy_from_user(addrs, uaddrs, size)) { 3028 err = -EFAULT; 3029 goto error; 3030 } 3031 } else { 3032 struct multi_symbols_sort data = { 3033 .cookies = cookies, 3034 }; 3035 struct user_syms us; 3036 3037 err = copy_user_syms(&us, usyms, cnt); 3038 if (err) 3039 goto error; 3040 3041 if (cookies) 3042 data.funcs = us.syms; 3043 3044 sort_r(us.syms, cnt, sizeof(*us.syms), symbols_cmp_r, 3045 symbols_swap_r, &data); 3046 3047 err = ftrace_lookup_symbols(us.syms, cnt, addrs); 3048 free_user_syms(&us); 3049 if (err) 3050 goto error; 3051 } 3052 3053 if (prog->kprobe_override && addrs_check_error_injection_list(addrs, cnt)) { 3054 err = -EINVAL; 3055 goto error; 3056 } 3057 3058 link = kzalloc(sizeof(*link), GFP_KERNEL); 3059 if (!link) { 3060 err = -ENOMEM; 3061 goto error; 3062 } 3063 3064 bpf_link_init(&link->link, BPF_LINK_TYPE_KPROBE_MULTI, 3065 &bpf_kprobe_multi_link_lops, prog); 3066 3067 err = bpf_link_prime(&link->link, &link_primer); 3068 if (err) 3069 goto error; 3070 3071 if (!(flags & BPF_F_KPROBE_MULTI_RETURN)) 3072 link->fp.entry_handler = kprobe_multi_link_handler; 3073 if ((flags & BPF_F_KPROBE_MULTI_RETURN) || is_kprobe_session(prog)) 3074 link->fp.exit_handler = kprobe_multi_link_exit_handler; 3075 if (is_kprobe_session(prog)) 3076 link->fp.entry_data_size = sizeof(u64); 3077 3078 link->addrs = addrs; 3079 link->cookies = cookies; 3080 link->cnt = cnt; 3081 link->flags = flags; 3082 3083 if (cookies) { 3084 /* 3085 * Sorting addresses will trigger sorting cookies as well 3086 * (check bpf_kprobe_multi_cookie_swap). This way we can 3087 * find cookie based on the address in bpf_get_attach_cookie 3088 * helper. 3089 */ 3090 sort_r(addrs, cnt, sizeof(*addrs), 3091 bpf_kprobe_multi_cookie_cmp, 3092 bpf_kprobe_multi_cookie_swap, 3093 link); 3094 } 3095 3096 err = get_modules_for_addrs(&link->mods, addrs, cnt); 3097 if (err < 0) { 3098 bpf_link_cleanup(&link_primer); 3099 return err; 3100 } 3101 link->mods_cnt = err; 3102 3103 err = register_fprobe_ips(&link->fp, addrs, cnt); 3104 if (err) { 3105 kprobe_multi_put_modules(link->mods, link->mods_cnt); 3106 bpf_link_cleanup(&link_primer); 3107 return err; 3108 } 3109 3110 return bpf_link_settle(&link_primer); 3111 3112 error: 3113 kfree(link); 3114 kvfree(addrs); 3115 kvfree(cookies); 3116 return err; 3117 } 3118 #else /* !CONFIG_FPROBE */ 3119 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 3120 { 3121 return -EOPNOTSUPP; 3122 } 3123 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx) 3124 { 3125 return 0; 3126 } 3127 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 3128 { 3129 return 0; 3130 } 3131 #endif 3132 3133 #ifdef CONFIG_UPROBES 3134 struct bpf_uprobe_multi_link; 3135 3136 struct bpf_uprobe { 3137 struct bpf_uprobe_multi_link *link; 3138 loff_t offset; 3139 unsigned long ref_ctr_offset; 3140 u64 cookie; 3141 struct uprobe *uprobe; 3142 struct uprobe_consumer consumer; 3143 bool session; 3144 }; 3145 3146 struct bpf_uprobe_multi_link { 3147 struct path path; 3148 struct bpf_link link; 3149 u32 cnt; 3150 u32 flags; 3151 struct bpf_uprobe *uprobes; 3152 struct task_struct *task; 3153 }; 3154 3155 struct bpf_uprobe_multi_run_ctx { 3156 struct bpf_session_run_ctx session_ctx; 3157 unsigned long entry_ip; 3158 struct bpf_uprobe *uprobe; 3159 }; 3160 3161 static void bpf_uprobe_unregister(struct bpf_uprobe *uprobes, u32 cnt) 3162 { 3163 u32 i; 3164 3165 for (i = 0; i < cnt; i++) 3166 uprobe_unregister_nosync(uprobes[i].uprobe, &uprobes[i].consumer); 3167 3168 if (cnt) 3169 uprobe_unregister_sync(); 3170 } 3171 3172 static void bpf_uprobe_multi_link_release(struct bpf_link *link) 3173 { 3174 struct bpf_uprobe_multi_link *umulti_link; 3175 3176 umulti_link = container_of(link, struct bpf_uprobe_multi_link, link); 3177 bpf_uprobe_unregister(umulti_link->uprobes, umulti_link->cnt); 3178 if (umulti_link->task) 3179 put_task_struct(umulti_link->task); 3180 path_put(&umulti_link->path); 3181 } 3182 3183 static void bpf_uprobe_multi_link_dealloc(struct bpf_link *link) 3184 { 3185 struct bpf_uprobe_multi_link *umulti_link; 3186 3187 umulti_link = container_of(link, struct bpf_uprobe_multi_link, link); 3188 kvfree(umulti_link->uprobes); 3189 kfree(umulti_link); 3190 } 3191 3192 static int bpf_uprobe_multi_link_fill_link_info(const struct bpf_link *link, 3193 struct bpf_link_info *info) 3194 { 3195 u64 __user *uref_ctr_offsets = u64_to_user_ptr(info->uprobe_multi.ref_ctr_offsets); 3196 u64 __user *ucookies = u64_to_user_ptr(info->uprobe_multi.cookies); 3197 u64 __user *uoffsets = u64_to_user_ptr(info->uprobe_multi.offsets); 3198 u64 __user *upath = u64_to_user_ptr(info->uprobe_multi.path); 3199 u32 upath_size = info->uprobe_multi.path_size; 3200 struct bpf_uprobe_multi_link *umulti_link; 3201 u32 ucount = info->uprobe_multi.count; 3202 int err = 0, i; 3203 char *p, *buf; 3204 long left = 0; 3205 3206 if (!upath ^ !upath_size) 3207 return -EINVAL; 3208 3209 if ((uoffsets || uref_ctr_offsets || ucookies) && !ucount) 3210 return -EINVAL; 3211 3212 umulti_link = container_of(link, struct bpf_uprobe_multi_link, link); 3213 info->uprobe_multi.count = umulti_link->cnt; 3214 info->uprobe_multi.flags = umulti_link->flags; 3215 info->uprobe_multi.pid = umulti_link->task ? 3216 task_pid_nr_ns(umulti_link->task, task_active_pid_ns(current)) : 0; 3217 3218 upath_size = upath_size ? min_t(u32, upath_size, PATH_MAX) : PATH_MAX; 3219 buf = kmalloc(upath_size, GFP_KERNEL); 3220 if (!buf) 3221 return -ENOMEM; 3222 p = d_path(&umulti_link->path, buf, upath_size); 3223 if (IS_ERR(p)) { 3224 kfree(buf); 3225 return PTR_ERR(p); 3226 } 3227 upath_size = buf + upath_size - p; 3228 3229 if (upath) 3230 left = copy_to_user(upath, p, upath_size); 3231 kfree(buf); 3232 if (left) 3233 return -EFAULT; 3234 info->uprobe_multi.path_size = upath_size; 3235 3236 if (!uoffsets && !ucookies && !uref_ctr_offsets) 3237 return 0; 3238 3239 if (ucount < umulti_link->cnt) 3240 err = -ENOSPC; 3241 else 3242 ucount = umulti_link->cnt; 3243 3244 for (i = 0; i < ucount; i++) { 3245 if (uoffsets && 3246 put_user(umulti_link->uprobes[i].offset, uoffsets + i)) 3247 return -EFAULT; 3248 if (uref_ctr_offsets && 3249 put_user(umulti_link->uprobes[i].ref_ctr_offset, uref_ctr_offsets + i)) 3250 return -EFAULT; 3251 if (ucookies && 3252 put_user(umulti_link->uprobes[i].cookie, ucookies + i)) 3253 return -EFAULT; 3254 } 3255 3256 return err; 3257 } 3258 3259 static const struct bpf_link_ops bpf_uprobe_multi_link_lops = { 3260 .release = bpf_uprobe_multi_link_release, 3261 .dealloc_deferred = bpf_uprobe_multi_link_dealloc, 3262 .fill_link_info = bpf_uprobe_multi_link_fill_link_info, 3263 }; 3264 3265 static int uprobe_prog_run(struct bpf_uprobe *uprobe, 3266 unsigned long entry_ip, 3267 struct pt_regs *regs, 3268 bool is_return, void *data) 3269 { 3270 struct bpf_uprobe_multi_link *link = uprobe->link; 3271 struct bpf_uprobe_multi_run_ctx run_ctx = { 3272 .session_ctx = { 3273 .is_return = is_return, 3274 .data = data, 3275 }, 3276 .entry_ip = entry_ip, 3277 .uprobe = uprobe, 3278 }; 3279 struct bpf_prog *prog = link->link.prog; 3280 bool sleepable = prog->sleepable; 3281 struct bpf_run_ctx *old_run_ctx; 3282 int err; 3283 3284 if (link->task && !same_thread_group(current, link->task)) 3285 return 0; 3286 3287 if (sleepable) 3288 rcu_read_lock_trace(); 3289 else 3290 rcu_read_lock(); 3291 3292 migrate_disable(); 3293 3294 old_run_ctx = bpf_set_run_ctx(&run_ctx.session_ctx.run_ctx); 3295 err = bpf_prog_run(link->link.prog, regs); 3296 bpf_reset_run_ctx(old_run_ctx); 3297 3298 migrate_enable(); 3299 3300 if (sleepable) 3301 rcu_read_unlock_trace(); 3302 else 3303 rcu_read_unlock(); 3304 return err; 3305 } 3306 3307 static bool 3308 uprobe_multi_link_filter(struct uprobe_consumer *con, struct mm_struct *mm) 3309 { 3310 struct bpf_uprobe *uprobe; 3311 3312 uprobe = container_of(con, struct bpf_uprobe, consumer); 3313 return uprobe->link->task->mm == mm; 3314 } 3315 3316 static int 3317 uprobe_multi_link_handler(struct uprobe_consumer *con, struct pt_regs *regs, 3318 __u64 *data) 3319 { 3320 struct bpf_uprobe *uprobe; 3321 int ret; 3322 3323 uprobe = container_of(con, struct bpf_uprobe, consumer); 3324 ret = uprobe_prog_run(uprobe, instruction_pointer(regs), regs, false, data); 3325 if (uprobe->session) 3326 return ret ? UPROBE_HANDLER_IGNORE : 0; 3327 return 0; 3328 } 3329 3330 static int 3331 uprobe_multi_link_ret_handler(struct uprobe_consumer *con, unsigned long func, struct pt_regs *regs, 3332 __u64 *data) 3333 { 3334 struct bpf_uprobe *uprobe; 3335 3336 uprobe = container_of(con, struct bpf_uprobe, consumer); 3337 uprobe_prog_run(uprobe, func, regs, true, data); 3338 return 0; 3339 } 3340 3341 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 3342 { 3343 struct bpf_uprobe_multi_run_ctx *run_ctx; 3344 3345 run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx, 3346 session_ctx.run_ctx); 3347 return run_ctx->entry_ip; 3348 } 3349 3350 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx) 3351 { 3352 struct bpf_uprobe_multi_run_ctx *run_ctx; 3353 3354 run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx, 3355 session_ctx.run_ctx); 3356 return run_ctx->uprobe->cookie; 3357 } 3358 3359 int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 3360 { 3361 struct bpf_uprobe_multi_link *link = NULL; 3362 unsigned long __user *uref_ctr_offsets; 3363 struct bpf_link_primer link_primer; 3364 struct bpf_uprobe *uprobes = NULL; 3365 struct task_struct *task = NULL; 3366 unsigned long __user *uoffsets; 3367 u64 __user *ucookies; 3368 void __user *upath; 3369 u32 flags, cnt, i; 3370 struct path path; 3371 char *name; 3372 pid_t pid; 3373 int err; 3374 3375 /* no support for 32bit archs yet */ 3376 if (sizeof(u64) != sizeof(void *)) 3377 return -EOPNOTSUPP; 3378 3379 if (!is_uprobe_multi(prog)) 3380 return -EINVAL; 3381 3382 flags = attr->link_create.uprobe_multi.flags; 3383 if (flags & ~BPF_F_UPROBE_MULTI_RETURN) 3384 return -EINVAL; 3385 3386 /* 3387 * path, offsets and cnt are mandatory, 3388 * ref_ctr_offsets and cookies are optional 3389 */ 3390 upath = u64_to_user_ptr(attr->link_create.uprobe_multi.path); 3391 uoffsets = u64_to_user_ptr(attr->link_create.uprobe_multi.offsets); 3392 cnt = attr->link_create.uprobe_multi.cnt; 3393 pid = attr->link_create.uprobe_multi.pid; 3394 3395 if (!upath || !uoffsets || !cnt || pid < 0) 3396 return -EINVAL; 3397 if (cnt > MAX_UPROBE_MULTI_CNT) 3398 return -E2BIG; 3399 3400 uref_ctr_offsets = u64_to_user_ptr(attr->link_create.uprobe_multi.ref_ctr_offsets); 3401 ucookies = u64_to_user_ptr(attr->link_create.uprobe_multi.cookies); 3402 3403 name = strndup_user(upath, PATH_MAX); 3404 if (IS_ERR(name)) { 3405 err = PTR_ERR(name); 3406 return err; 3407 } 3408 3409 err = kern_path(name, LOOKUP_FOLLOW, &path); 3410 kfree(name); 3411 if (err) 3412 return err; 3413 3414 if (!d_is_reg(path.dentry)) { 3415 err = -EBADF; 3416 goto error_path_put; 3417 } 3418 3419 if (pid) { 3420 task = get_pid_task(find_vpid(pid), PIDTYPE_TGID); 3421 if (!task) { 3422 err = -ESRCH; 3423 goto error_path_put; 3424 } 3425 } 3426 3427 err = -ENOMEM; 3428 3429 link = kzalloc(sizeof(*link), GFP_KERNEL); 3430 uprobes = kvcalloc(cnt, sizeof(*uprobes), GFP_KERNEL); 3431 3432 if (!uprobes || !link) 3433 goto error_free; 3434 3435 for (i = 0; i < cnt; i++) { 3436 if (__get_user(uprobes[i].offset, uoffsets + i)) { 3437 err = -EFAULT; 3438 goto error_free; 3439 } 3440 if (uprobes[i].offset < 0) { 3441 err = -EINVAL; 3442 goto error_free; 3443 } 3444 if (uref_ctr_offsets && __get_user(uprobes[i].ref_ctr_offset, uref_ctr_offsets + i)) { 3445 err = -EFAULT; 3446 goto error_free; 3447 } 3448 if (ucookies && __get_user(uprobes[i].cookie, ucookies + i)) { 3449 err = -EFAULT; 3450 goto error_free; 3451 } 3452 3453 uprobes[i].link = link; 3454 3455 if (!(flags & BPF_F_UPROBE_MULTI_RETURN)) 3456 uprobes[i].consumer.handler = uprobe_multi_link_handler; 3457 if (flags & BPF_F_UPROBE_MULTI_RETURN || is_uprobe_session(prog)) 3458 uprobes[i].consumer.ret_handler = uprobe_multi_link_ret_handler; 3459 if (is_uprobe_session(prog)) 3460 uprobes[i].session = true; 3461 if (pid) 3462 uprobes[i].consumer.filter = uprobe_multi_link_filter; 3463 } 3464 3465 link->cnt = cnt; 3466 link->uprobes = uprobes; 3467 link->path = path; 3468 link->task = task; 3469 link->flags = flags; 3470 3471 bpf_link_init(&link->link, BPF_LINK_TYPE_UPROBE_MULTI, 3472 &bpf_uprobe_multi_link_lops, prog); 3473 3474 for (i = 0; i < cnt; i++) { 3475 uprobes[i].uprobe = uprobe_register(d_real_inode(link->path.dentry), 3476 uprobes[i].offset, 3477 uprobes[i].ref_ctr_offset, 3478 &uprobes[i].consumer); 3479 if (IS_ERR(uprobes[i].uprobe)) { 3480 err = PTR_ERR(uprobes[i].uprobe); 3481 link->cnt = i; 3482 goto error_unregister; 3483 } 3484 } 3485 3486 err = bpf_link_prime(&link->link, &link_primer); 3487 if (err) 3488 goto error_unregister; 3489 3490 return bpf_link_settle(&link_primer); 3491 3492 error_unregister: 3493 bpf_uprobe_unregister(uprobes, link->cnt); 3494 3495 error_free: 3496 kvfree(uprobes); 3497 kfree(link); 3498 if (task) 3499 put_task_struct(task); 3500 error_path_put: 3501 path_put(&path); 3502 return err; 3503 } 3504 #else /* !CONFIG_UPROBES */ 3505 int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 3506 { 3507 return -EOPNOTSUPP; 3508 } 3509 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx) 3510 { 3511 return 0; 3512 } 3513 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 3514 { 3515 return 0; 3516 } 3517 #endif /* CONFIG_UPROBES */ 3518 3519 __bpf_kfunc_start_defs(); 3520 3521 __bpf_kfunc bool bpf_session_is_return(void) 3522 { 3523 struct bpf_session_run_ctx *session_ctx; 3524 3525 session_ctx = container_of(current->bpf_ctx, struct bpf_session_run_ctx, run_ctx); 3526 return session_ctx->is_return; 3527 } 3528 3529 __bpf_kfunc __u64 *bpf_session_cookie(void) 3530 { 3531 struct bpf_session_run_ctx *session_ctx; 3532 3533 session_ctx = container_of(current->bpf_ctx, struct bpf_session_run_ctx, run_ctx); 3534 return session_ctx->data; 3535 } 3536 3537 __bpf_kfunc_end_defs(); 3538 3539 BTF_KFUNCS_START(kprobe_multi_kfunc_set_ids) 3540 BTF_ID_FLAGS(func, bpf_session_is_return) 3541 BTF_ID_FLAGS(func, bpf_session_cookie) 3542 BTF_KFUNCS_END(kprobe_multi_kfunc_set_ids) 3543 3544 static int bpf_kprobe_multi_filter(const struct bpf_prog *prog, u32 kfunc_id) 3545 { 3546 if (!btf_id_set8_contains(&kprobe_multi_kfunc_set_ids, kfunc_id)) 3547 return 0; 3548 3549 if (!is_kprobe_session(prog) && !is_uprobe_session(prog)) 3550 return -EACCES; 3551 3552 return 0; 3553 } 3554 3555 static const struct btf_kfunc_id_set bpf_kprobe_multi_kfunc_set = { 3556 .owner = THIS_MODULE, 3557 .set = &kprobe_multi_kfunc_set_ids, 3558 .filter = bpf_kprobe_multi_filter, 3559 }; 3560 3561 static int __init bpf_kprobe_multi_kfuncs_init(void) 3562 { 3563 return register_btf_kfunc_id_set(BPF_PROG_TYPE_KPROBE, &bpf_kprobe_multi_kfunc_set); 3564 } 3565 3566 late_initcall(bpf_kprobe_multi_kfuncs_init); 3567 3568 __bpf_kfunc_start_defs(); 3569 3570 __bpf_kfunc int bpf_send_signal_task(struct task_struct *task, int sig, enum pid_type type, 3571 u64 value) 3572 { 3573 if (type != PIDTYPE_PID && type != PIDTYPE_TGID) 3574 return -EINVAL; 3575 3576 return bpf_send_signal_common(sig, type, task, value); 3577 } 3578 3579 __bpf_kfunc_end_defs(); 3580