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(void) 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 } 408 409 const struct bpf_func_proto *bpf_get_trace_printk_proto(void) 410 { 411 __set_printk_clr_event(); 412 return &bpf_trace_printk_proto; 413 } 414 415 BPF_CALL_4(bpf_trace_vprintk, char *, fmt, u32, fmt_size, const void *, args, 416 u32, data_len) 417 { 418 struct bpf_bprintf_data data = { 419 .get_bin_args = true, 420 .get_buf = true, 421 }; 422 int ret, num_args; 423 424 if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 || 425 (data_len && !args)) 426 return -EINVAL; 427 num_args = data_len / 8; 428 429 ret = bpf_bprintf_prepare(fmt, fmt_size, args, num_args, &data); 430 if (ret < 0) 431 return ret; 432 433 ret = bstr_printf(data.buf, MAX_BPRINTF_BUF, fmt, data.bin_args); 434 435 trace_bpf_trace_printk(data.buf); 436 437 bpf_bprintf_cleanup(&data); 438 439 return ret; 440 } 441 442 static const struct bpf_func_proto bpf_trace_vprintk_proto = { 443 .func = bpf_trace_vprintk, 444 .gpl_only = true, 445 .ret_type = RET_INTEGER, 446 .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY, 447 .arg2_type = ARG_CONST_SIZE, 448 .arg3_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY, 449 .arg4_type = ARG_CONST_SIZE_OR_ZERO, 450 }; 451 452 const struct bpf_func_proto *bpf_get_trace_vprintk_proto(void) 453 { 454 __set_printk_clr_event(); 455 return &bpf_trace_vprintk_proto; 456 } 457 458 BPF_CALL_5(bpf_seq_printf, struct seq_file *, m, char *, fmt, u32, fmt_size, 459 const void *, args, u32, data_len) 460 { 461 struct bpf_bprintf_data data = { 462 .get_bin_args = true, 463 }; 464 int err, num_args; 465 466 if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 || 467 (data_len && !args)) 468 return -EINVAL; 469 num_args = data_len / 8; 470 471 err = bpf_bprintf_prepare(fmt, fmt_size, args, num_args, &data); 472 if (err < 0) 473 return err; 474 475 seq_bprintf(m, fmt, data.bin_args); 476 477 bpf_bprintf_cleanup(&data); 478 479 return seq_has_overflowed(m) ? -EOVERFLOW : 0; 480 } 481 482 BTF_ID_LIST_SINGLE(btf_seq_file_ids, struct, seq_file) 483 484 static const struct bpf_func_proto bpf_seq_printf_proto = { 485 .func = bpf_seq_printf, 486 .gpl_only = true, 487 .ret_type = RET_INTEGER, 488 .arg1_type = ARG_PTR_TO_BTF_ID, 489 .arg1_btf_id = &btf_seq_file_ids[0], 490 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 491 .arg3_type = ARG_CONST_SIZE, 492 .arg4_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY, 493 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 494 }; 495 496 BPF_CALL_3(bpf_seq_write, struct seq_file *, m, const void *, data, u32, len) 497 { 498 return seq_write(m, data, len) ? -EOVERFLOW : 0; 499 } 500 501 static const struct bpf_func_proto bpf_seq_write_proto = { 502 .func = bpf_seq_write, 503 .gpl_only = true, 504 .ret_type = RET_INTEGER, 505 .arg1_type = ARG_PTR_TO_BTF_ID, 506 .arg1_btf_id = &btf_seq_file_ids[0], 507 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 508 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 509 }; 510 511 BPF_CALL_4(bpf_seq_printf_btf, struct seq_file *, m, struct btf_ptr *, ptr, 512 u32, btf_ptr_size, u64, flags) 513 { 514 const struct btf *btf; 515 s32 btf_id; 516 int ret; 517 518 ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id); 519 if (ret) 520 return ret; 521 522 return btf_type_seq_show_flags(btf, btf_id, ptr->ptr, m, flags); 523 } 524 525 static const struct bpf_func_proto bpf_seq_printf_btf_proto = { 526 .func = bpf_seq_printf_btf, 527 .gpl_only = true, 528 .ret_type = RET_INTEGER, 529 .arg1_type = ARG_PTR_TO_BTF_ID, 530 .arg1_btf_id = &btf_seq_file_ids[0], 531 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 532 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 533 .arg4_type = ARG_ANYTHING, 534 }; 535 536 static __always_inline int 537 get_map_perf_counter(struct bpf_map *map, u64 flags, 538 u64 *value, u64 *enabled, u64 *running) 539 { 540 struct bpf_array *array = container_of(map, struct bpf_array, map); 541 unsigned int cpu = smp_processor_id(); 542 u64 index = flags & BPF_F_INDEX_MASK; 543 struct bpf_event_entry *ee; 544 545 if (unlikely(flags & ~(BPF_F_INDEX_MASK))) 546 return -EINVAL; 547 if (index == BPF_F_CURRENT_CPU) 548 index = cpu; 549 if (unlikely(index >= array->map.max_entries)) 550 return -E2BIG; 551 552 ee = READ_ONCE(array->ptrs[index]); 553 if (!ee) 554 return -ENOENT; 555 556 return perf_event_read_local(ee->event, value, enabled, running); 557 } 558 559 BPF_CALL_2(bpf_perf_event_read, struct bpf_map *, map, u64, flags) 560 { 561 u64 value = 0; 562 int err; 563 564 err = get_map_perf_counter(map, flags, &value, NULL, NULL); 565 /* 566 * this api is ugly since we miss [-22..-2] range of valid 567 * counter values, but that's uapi 568 */ 569 if (err) 570 return err; 571 return value; 572 } 573 574 static const struct bpf_func_proto bpf_perf_event_read_proto = { 575 .func = bpf_perf_event_read, 576 .gpl_only = true, 577 .ret_type = RET_INTEGER, 578 .arg1_type = ARG_CONST_MAP_PTR, 579 .arg2_type = ARG_ANYTHING, 580 }; 581 582 BPF_CALL_4(bpf_perf_event_read_value, struct bpf_map *, map, u64, flags, 583 struct bpf_perf_event_value *, buf, u32, size) 584 { 585 int err = -EINVAL; 586 587 if (unlikely(size != sizeof(struct bpf_perf_event_value))) 588 goto clear; 589 err = get_map_perf_counter(map, flags, &buf->counter, &buf->enabled, 590 &buf->running); 591 if (unlikely(err)) 592 goto clear; 593 return 0; 594 clear: 595 memset(buf, 0, size); 596 return err; 597 } 598 599 static const struct bpf_func_proto bpf_perf_event_read_value_proto = { 600 .func = bpf_perf_event_read_value, 601 .gpl_only = true, 602 .ret_type = RET_INTEGER, 603 .arg1_type = ARG_CONST_MAP_PTR, 604 .arg2_type = ARG_ANYTHING, 605 .arg3_type = ARG_PTR_TO_UNINIT_MEM, 606 .arg4_type = ARG_CONST_SIZE, 607 }; 608 609 static __always_inline u64 610 __bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map, 611 u64 flags, struct perf_sample_data *sd) 612 { 613 struct bpf_array *array = container_of(map, struct bpf_array, map); 614 unsigned int cpu = smp_processor_id(); 615 u64 index = flags & BPF_F_INDEX_MASK; 616 struct bpf_event_entry *ee; 617 struct perf_event *event; 618 619 if (index == BPF_F_CURRENT_CPU) 620 index = cpu; 621 if (unlikely(index >= array->map.max_entries)) 622 return -E2BIG; 623 624 ee = READ_ONCE(array->ptrs[index]); 625 if (!ee) 626 return -ENOENT; 627 628 event = ee->event; 629 if (unlikely(event->attr.type != PERF_TYPE_SOFTWARE || 630 event->attr.config != PERF_COUNT_SW_BPF_OUTPUT)) 631 return -EINVAL; 632 633 if (unlikely(event->oncpu != cpu)) 634 return -EOPNOTSUPP; 635 636 return perf_event_output(event, sd, regs); 637 } 638 639 /* 640 * Support executing tracepoints in normal, irq, and nmi context that each call 641 * bpf_perf_event_output 642 */ 643 struct bpf_trace_sample_data { 644 struct perf_sample_data sds[3]; 645 }; 646 647 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_trace_sds); 648 static DEFINE_PER_CPU(int, bpf_trace_nest_level); 649 BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map, 650 u64, flags, void *, data, u64, size) 651 { 652 struct bpf_trace_sample_data *sds; 653 struct perf_raw_record raw = { 654 .frag = { 655 .size = size, 656 .data = data, 657 }, 658 }; 659 struct perf_sample_data *sd; 660 int nest_level, err; 661 662 preempt_disable(); 663 sds = this_cpu_ptr(&bpf_trace_sds); 664 nest_level = this_cpu_inc_return(bpf_trace_nest_level); 665 666 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(sds->sds))) { 667 err = -EBUSY; 668 goto out; 669 } 670 671 sd = &sds->sds[nest_level - 1]; 672 673 if (unlikely(flags & ~(BPF_F_INDEX_MASK))) { 674 err = -EINVAL; 675 goto out; 676 } 677 678 perf_sample_data_init(sd, 0, 0); 679 perf_sample_save_raw_data(sd, &raw); 680 681 err = __bpf_perf_event_output(regs, map, flags, sd); 682 out: 683 this_cpu_dec(bpf_trace_nest_level); 684 preempt_enable(); 685 return err; 686 } 687 688 static const struct bpf_func_proto bpf_perf_event_output_proto = { 689 .func = bpf_perf_event_output, 690 .gpl_only = true, 691 .ret_type = RET_INTEGER, 692 .arg1_type = ARG_PTR_TO_CTX, 693 .arg2_type = ARG_CONST_MAP_PTR, 694 .arg3_type = ARG_ANYTHING, 695 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, 696 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 697 }; 698 699 static DEFINE_PER_CPU(int, bpf_event_output_nest_level); 700 struct bpf_nested_pt_regs { 701 struct pt_regs regs[3]; 702 }; 703 static DEFINE_PER_CPU(struct bpf_nested_pt_regs, bpf_pt_regs); 704 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_misc_sds); 705 706 u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size, 707 void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy) 708 { 709 struct perf_raw_frag frag = { 710 .copy = ctx_copy, 711 .size = ctx_size, 712 .data = ctx, 713 }; 714 struct perf_raw_record raw = { 715 .frag = { 716 { 717 .next = ctx_size ? &frag : NULL, 718 }, 719 .size = meta_size, 720 .data = meta, 721 }, 722 }; 723 struct perf_sample_data *sd; 724 struct pt_regs *regs; 725 int nest_level; 726 u64 ret; 727 728 preempt_disable(); 729 nest_level = this_cpu_inc_return(bpf_event_output_nest_level); 730 731 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(bpf_misc_sds.sds))) { 732 ret = -EBUSY; 733 goto out; 734 } 735 sd = this_cpu_ptr(&bpf_misc_sds.sds[nest_level - 1]); 736 regs = this_cpu_ptr(&bpf_pt_regs.regs[nest_level - 1]); 737 738 perf_fetch_caller_regs(regs); 739 perf_sample_data_init(sd, 0, 0); 740 perf_sample_save_raw_data(sd, &raw); 741 742 ret = __bpf_perf_event_output(regs, map, flags, sd); 743 out: 744 this_cpu_dec(bpf_event_output_nest_level); 745 preempt_enable(); 746 return ret; 747 } 748 749 BPF_CALL_0(bpf_get_current_task) 750 { 751 return (long) current; 752 } 753 754 const struct bpf_func_proto bpf_get_current_task_proto = { 755 .func = bpf_get_current_task, 756 .gpl_only = true, 757 .ret_type = RET_INTEGER, 758 }; 759 760 BPF_CALL_0(bpf_get_current_task_btf) 761 { 762 return (unsigned long) current; 763 } 764 765 const struct bpf_func_proto bpf_get_current_task_btf_proto = { 766 .func = bpf_get_current_task_btf, 767 .gpl_only = true, 768 .ret_type = RET_PTR_TO_BTF_ID_TRUSTED, 769 .ret_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK], 770 }; 771 772 BPF_CALL_1(bpf_task_pt_regs, struct task_struct *, task) 773 { 774 return (unsigned long) task_pt_regs(task); 775 } 776 777 BTF_ID_LIST(bpf_task_pt_regs_ids) 778 BTF_ID(struct, pt_regs) 779 780 const struct bpf_func_proto bpf_task_pt_regs_proto = { 781 .func = bpf_task_pt_regs, 782 .gpl_only = true, 783 .arg1_type = ARG_PTR_TO_BTF_ID, 784 .arg1_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK], 785 .ret_type = RET_PTR_TO_BTF_ID, 786 .ret_btf_id = &bpf_task_pt_regs_ids[0], 787 }; 788 789 struct send_signal_irq_work { 790 struct irq_work irq_work; 791 struct task_struct *task; 792 u32 sig; 793 enum pid_type type; 794 bool has_siginfo; 795 struct kernel_siginfo info; 796 }; 797 798 static DEFINE_PER_CPU(struct send_signal_irq_work, send_signal_work); 799 800 static void do_bpf_send_signal(struct irq_work *entry) 801 { 802 struct send_signal_irq_work *work; 803 struct kernel_siginfo *siginfo; 804 805 work = container_of(entry, struct send_signal_irq_work, irq_work); 806 siginfo = work->has_siginfo ? &work->info : SEND_SIG_PRIV; 807 808 group_send_sig_info(work->sig, siginfo, work->task, work->type); 809 put_task_struct(work->task); 810 } 811 812 static int bpf_send_signal_common(u32 sig, enum pid_type type, struct task_struct *task, u64 value) 813 { 814 struct send_signal_irq_work *work = NULL; 815 struct kernel_siginfo info; 816 struct kernel_siginfo *siginfo; 817 818 if (!task) { 819 task = current; 820 siginfo = SEND_SIG_PRIV; 821 } else { 822 clear_siginfo(&info); 823 info.si_signo = sig; 824 info.si_errno = 0; 825 info.si_code = SI_KERNEL; 826 info.si_pid = 0; 827 info.si_uid = 0; 828 info.si_value.sival_ptr = (void *)(unsigned long)value; 829 siginfo = &info; 830 } 831 832 /* Similar to bpf_probe_write_user, task needs to be 833 * in a sound condition and kernel memory access be 834 * permitted in order to send signal to the current 835 * task. 836 */ 837 if (unlikely(task->flags & (PF_KTHREAD | PF_EXITING))) 838 return -EPERM; 839 if (unlikely(!nmi_uaccess_okay())) 840 return -EPERM; 841 /* Task should not be pid=1 to avoid kernel panic. */ 842 if (unlikely(is_global_init(task))) 843 return -EPERM; 844 845 if (irqs_disabled()) { 846 /* Do an early check on signal validity. Otherwise, 847 * the error is lost in deferred irq_work. 848 */ 849 if (unlikely(!valid_signal(sig))) 850 return -EINVAL; 851 852 work = this_cpu_ptr(&send_signal_work); 853 if (irq_work_is_busy(&work->irq_work)) 854 return -EBUSY; 855 856 /* Add the current task, which is the target of sending signal, 857 * to the irq_work. The current task may change when queued 858 * irq works get executed. 859 */ 860 work->task = get_task_struct(task); 861 work->has_siginfo = siginfo == &info; 862 if (work->has_siginfo) 863 copy_siginfo(&work->info, &info); 864 work->sig = sig; 865 work->type = type; 866 irq_work_queue(&work->irq_work); 867 return 0; 868 } 869 870 return group_send_sig_info(sig, siginfo, task, type); 871 } 872 873 BPF_CALL_1(bpf_send_signal, u32, sig) 874 { 875 return bpf_send_signal_common(sig, PIDTYPE_TGID, NULL, 0); 876 } 877 878 static const struct bpf_func_proto bpf_send_signal_proto = { 879 .func = bpf_send_signal, 880 .gpl_only = false, 881 .ret_type = RET_INTEGER, 882 .arg1_type = ARG_ANYTHING, 883 }; 884 885 BPF_CALL_1(bpf_send_signal_thread, u32, sig) 886 { 887 return bpf_send_signal_common(sig, PIDTYPE_PID, NULL, 0); 888 } 889 890 static const struct bpf_func_proto bpf_send_signal_thread_proto = { 891 .func = bpf_send_signal_thread, 892 .gpl_only = false, 893 .ret_type = RET_INTEGER, 894 .arg1_type = ARG_ANYTHING, 895 }; 896 897 BPF_CALL_3(bpf_d_path, struct path *, path, char *, buf, u32, sz) 898 { 899 struct path copy; 900 long len; 901 char *p; 902 903 if (!sz) 904 return 0; 905 906 /* 907 * The path pointer is verified as trusted and safe to use, 908 * but let's double check it's valid anyway to workaround 909 * potentially broken verifier. 910 */ 911 len = copy_from_kernel_nofault(©, path, sizeof(*path)); 912 if (len < 0) 913 return len; 914 915 p = d_path(©, buf, sz); 916 if (IS_ERR(p)) { 917 len = PTR_ERR(p); 918 } else { 919 len = buf + sz - p; 920 memmove(buf, p, len); 921 } 922 923 return len; 924 } 925 926 BTF_SET_START(btf_allowlist_d_path) 927 #ifdef CONFIG_SECURITY 928 BTF_ID(func, security_file_permission) 929 BTF_ID(func, security_inode_getattr) 930 BTF_ID(func, security_file_open) 931 #endif 932 #ifdef CONFIG_SECURITY_PATH 933 BTF_ID(func, security_path_truncate) 934 #endif 935 BTF_ID(func, vfs_truncate) 936 BTF_ID(func, vfs_fallocate) 937 BTF_ID(func, dentry_open) 938 BTF_ID(func, vfs_getattr) 939 BTF_ID(func, filp_close) 940 BTF_SET_END(btf_allowlist_d_path) 941 942 static bool bpf_d_path_allowed(const struct bpf_prog *prog) 943 { 944 if (prog->type == BPF_PROG_TYPE_TRACING && 945 prog->expected_attach_type == BPF_TRACE_ITER) 946 return true; 947 948 if (prog->type == BPF_PROG_TYPE_LSM) 949 return bpf_lsm_is_sleepable_hook(prog->aux->attach_btf_id); 950 951 return btf_id_set_contains(&btf_allowlist_d_path, 952 prog->aux->attach_btf_id); 953 } 954 955 BTF_ID_LIST_SINGLE(bpf_d_path_btf_ids, struct, path) 956 957 static const struct bpf_func_proto bpf_d_path_proto = { 958 .func = bpf_d_path, 959 .gpl_only = false, 960 .ret_type = RET_INTEGER, 961 .arg1_type = ARG_PTR_TO_BTF_ID, 962 .arg1_btf_id = &bpf_d_path_btf_ids[0], 963 .arg2_type = ARG_PTR_TO_MEM, 964 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 965 .allowed = bpf_d_path_allowed, 966 }; 967 968 #define BTF_F_ALL (BTF_F_COMPACT | BTF_F_NONAME | \ 969 BTF_F_PTR_RAW | BTF_F_ZERO) 970 971 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size, 972 u64 flags, const struct btf **btf, 973 s32 *btf_id) 974 { 975 const struct btf_type *t; 976 977 if (unlikely(flags & ~(BTF_F_ALL))) 978 return -EINVAL; 979 980 if (btf_ptr_size != sizeof(struct btf_ptr)) 981 return -EINVAL; 982 983 *btf = bpf_get_btf_vmlinux(); 984 985 if (IS_ERR_OR_NULL(*btf)) 986 return IS_ERR(*btf) ? PTR_ERR(*btf) : -EINVAL; 987 988 if (ptr->type_id > 0) 989 *btf_id = ptr->type_id; 990 else 991 return -EINVAL; 992 993 if (*btf_id > 0) 994 t = btf_type_by_id(*btf, *btf_id); 995 if (*btf_id <= 0 || !t) 996 return -ENOENT; 997 998 return 0; 999 } 1000 1001 BPF_CALL_5(bpf_snprintf_btf, char *, str, u32, str_size, struct btf_ptr *, ptr, 1002 u32, btf_ptr_size, u64, flags) 1003 { 1004 const struct btf *btf; 1005 s32 btf_id; 1006 int ret; 1007 1008 ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id); 1009 if (ret) 1010 return ret; 1011 1012 return btf_type_snprintf_show(btf, btf_id, ptr->ptr, str, str_size, 1013 flags); 1014 } 1015 1016 const struct bpf_func_proto bpf_snprintf_btf_proto = { 1017 .func = bpf_snprintf_btf, 1018 .gpl_only = false, 1019 .ret_type = RET_INTEGER, 1020 .arg1_type = ARG_PTR_TO_MEM, 1021 .arg2_type = ARG_CONST_SIZE, 1022 .arg3_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1023 .arg4_type = ARG_CONST_SIZE, 1024 .arg5_type = ARG_ANYTHING, 1025 }; 1026 1027 BPF_CALL_1(bpf_get_func_ip_tracing, void *, ctx) 1028 { 1029 /* This helper call is inlined by verifier. */ 1030 return ((u64 *)ctx)[-2]; 1031 } 1032 1033 static const struct bpf_func_proto bpf_get_func_ip_proto_tracing = { 1034 .func = bpf_get_func_ip_tracing, 1035 .gpl_only = true, 1036 .ret_type = RET_INTEGER, 1037 .arg1_type = ARG_PTR_TO_CTX, 1038 }; 1039 1040 #ifdef CONFIG_X86_KERNEL_IBT 1041 static unsigned long get_entry_ip(unsigned long fentry_ip) 1042 { 1043 u32 instr; 1044 1045 /* We want to be extra safe in case entry ip is on the page edge, 1046 * but otherwise we need to avoid get_kernel_nofault()'s overhead. 1047 */ 1048 if ((fentry_ip & ~PAGE_MASK) < ENDBR_INSN_SIZE) { 1049 if (get_kernel_nofault(instr, (u32 *)(fentry_ip - ENDBR_INSN_SIZE))) 1050 return fentry_ip; 1051 } else { 1052 instr = *(u32 *)(fentry_ip - ENDBR_INSN_SIZE); 1053 } 1054 if (is_endbr(instr)) 1055 fentry_ip -= ENDBR_INSN_SIZE; 1056 return fentry_ip; 1057 } 1058 #else 1059 #define get_entry_ip(fentry_ip) fentry_ip 1060 #endif 1061 1062 BPF_CALL_1(bpf_get_func_ip_kprobe, struct pt_regs *, regs) 1063 { 1064 struct bpf_trace_run_ctx *run_ctx __maybe_unused; 1065 struct kprobe *kp; 1066 1067 #ifdef CONFIG_UPROBES 1068 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); 1069 if (run_ctx->is_uprobe) 1070 return ((struct uprobe_dispatch_data *)current->utask->vaddr)->bp_addr; 1071 #endif 1072 1073 kp = kprobe_running(); 1074 1075 if (!kp || !(kp->flags & KPROBE_FLAG_ON_FUNC_ENTRY)) 1076 return 0; 1077 1078 return get_entry_ip((uintptr_t)kp->addr); 1079 } 1080 1081 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe = { 1082 .func = bpf_get_func_ip_kprobe, 1083 .gpl_only = true, 1084 .ret_type = RET_INTEGER, 1085 .arg1_type = ARG_PTR_TO_CTX, 1086 }; 1087 1088 BPF_CALL_1(bpf_get_func_ip_kprobe_multi, struct pt_regs *, regs) 1089 { 1090 return bpf_kprobe_multi_entry_ip(current->bpf_ctx); 1091 } 1092 1093 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe_multi = { 1094 .func = bpf_get_func_ip_kprobe_multi, 1095 .gpl_only = false, 1096 .ret_type = RET_INTEGER, 1097 .arg1_type = ARG_PTR_TO_CTX, 1098 }; 1099 1100 BPF_CALL_1(bpf_get_attach_cookie_kprobe_multi, struct pt_regs *, regs) 1101 { 1102 return bpf_kprobe_multi_cookie(current->bpf_ctx); 1103 } 1104 1105 static const struct bpf_func_proto bpf_get_attach_cookie_proto_kmulti = { 1106 .func = bpf_get_attach_cookie_kprobe_multi, 1107 .gpl_only = false, 1108 .ret_type = RET_INTEGER, 1109 .arg1_type = ARG_PTR_TO_CTX, 1110 }; 1111 1112 BPF_CALL_1(bpf_get_func_ip_uprobe_multi, struct pt_regs *, regs) 1113 { 1114 return bpf_uprobe_multi_entry_ip(current->bpf_ctx); 1115 } 1116 1117 static const struct bpf_func_proto bpf_get_func_ip_proto_uprobe_multi = { 1118 .func = bpf_get_func_ip_uprobe_multi, 1119 .gpl_only = false, 1120 .ret_type = RET_INTEGER, 1121 .arg1_type = ARG_PTR_TO_CTX, 1122 }; 1123 1124 BPF_CALL_1(bpf_get_attach_cookie_uprobe_multi, struct pt_regs *, regs) 1125 { 1126 return bpf_uprobe_multi_cookie(current->bpf_ctx); 1127 } 1128 1129 static const struct bpf_func_proto bpf_get_attach_cookie_proto_umulti = { 1130 .func = bpf_get_attach_cookie_uprobe_multi, 1131 .gpl_only = false, 1132 .ret_type = RET_INTEGER, 1133 .arg1_type = ARG_PTR_TO_CTX, 1134 }; 1135 1136 BPF_CALL_1(bpf_get_attach_cookie_trace, void *, ctx) 1137 { 1138 struct bpf_trace_run_ctx *run_ctx; 1139 1140 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); 1141 return run_ctx->bpf_cookie; 1142 } 1143 1144 static const struct bpf_func_proto bpf_get_attach_cookie_proto_trace = { 1145 .func = bpf_get_attach_cookie_trace, 1146 .gpl_only = false, 1147 .ret_type = RET_INTEGER, 1148 .arg1_type = ARG_PTR_TO_CTX, 1149 }; 1150 1151 BPF_CALL_1(bpf_get_attach_cookie_pe, struct bpf_perf_event_data_kern *, ctx) 1152 { 1153 return ctx->event->bpf_cookie; 1154 } 1155 1156 static const struct bpf_func_proto bpf_get_attach_cookie_proto_pe = { 1157 .func = bpf_get_attach_cookie_pe, 1158 .gpl_only = false, 1159 .ret_type = RET_INTEGER, 1160 .arg1_type = ARG_PTR_TO_CTX, 1161 }; 1162 1163 BPF_CALL_1(bpf_get_attach_cookie_tracing, void *, ctx) 1164 { 1165 struct bpf_trace_run_ctx *run_ctx; 1166 1167 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); 1168 return run_ctx->bpf_cookie; 1169 } 1170 1171 static const struct bpf_func_proto bpf_get_attach_cookie_proto_tracing = { 1172 .func = bpf_get_attach_cookie_tracing, 1173 .gpl_only = false, 1174 .ret_type = RET_INTEGER, 1175 .arg1_type = ARG_PTR_TO_CTX, 1176 }; 1177 1178 BPF_CALL_3(bpf_get_branch_snapshot, void *, buf, u32, size, u64, flags) 1179 { 1180 static const u32 br_entry_size = sizeof(struct perf_branch_entry); 1181 u32 entry_cnt = size / br_entry_size; 1182 1183 entry_cnt = static_call(perf_snapshot_branch_stack)(buf, entry_cnt); 1184 1185 if (unlikely(flags)) 1186 return -EINVAL; 1187 1188 if (!entry_cnt) 1189 return -ENOENT; 1190 1191 return entry_cnt * br_entry_size; 1192 } 1193 1194 static const struct bpf_func_proto bpf_get_branch_snapshot_proto = { 1195 .func = bpf_get_branch_snapshot, 1196 .gpl_only = true, 1197 .ret_type = RET_INTEGER, 1198 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 1199 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 1200 }; 1201 1202 BPF_CALL_3(get_func_arg, void *, ctx, u32, n, u64 *, value) 1203 { 1204 /* This helper call is inlined by verifier. */ 1205 u64 nr_args = ((u64 *)ctx)[-1]; 1206 1207 if ((u64) n >= nr_args) 1208 return -EINVAL; 1209 *value = ((u64 *)ctx)[n]; 1210 return 0; 1211 } 1212 1213 static const struct bpf_func_proto bpf_get_func_arg_proto = { 1214 .func = get_func_arg, 1215 .ret_type = RET_INTEGER, 1216 .arg1_type = ARG_PTR_TO_CTX, 1217 .arg2_type = ARG_ANYTHING, 1218 .arg3_type = ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED, 1219 .arg3_size = sizeof(u64), 1220 }; 1221 1222 BPF_CALL_2(get_func_ret, void *, ctx, u64 *, value) 1223 { 1224 /* This helper call is inlined by verifier. */ 1225 u64 nr_args = ((u64 *)ctx)[-1]; 1226 1227 *value = ((u64 *)ctx)[nr_args]; 1228 return 0; 1229 } 1230 1231 static const struct bpf_func_proto bpf_get_func_ret_proto = { 1232 .func = get_func_ret, 1233 .ret_type = RET_INTEGER, 1234 .arg1_type = ARG_PTR_TO_CTX, 1235 .arg2_type = ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED, 1236 .arg2_size = sizeof(u64), 1237 }; 1238 1239 BPF_CALL_1(get_func_arg_cnt, void *, ctx) 1240 { 1241 /* This helper call is inlined by verifier. */ 1242 return ((u64 *)ctx)[-1]; 1243 } 1244 1245 static const struct bpf_func_proto bpf_get_func_arg_cnt_proto = { 1246 .func = get_func_arg_cnt, 1247 .ret_type = RET_INTEGER, 1248 .arg1_type = ARG_PTR_TO_CTX, 1249 }; 1250 1251 #ifdef CONFIG_KEYS 1252 __bpf_kfunc_start_defs(); 1253 1254 /** 1255 * bpf_lookup_user_key - lookup a key by its serial 1256 * @serial: key handle serial number 1257 * @flags: lookup-specific flags 1258 * 1259 * Search a key with a given *serial* and the provided *flags*. 1260 * If found, increment the reference count of the key by one, and 1261 * return it in the bpf_key structure. 1262 * 1263 * The bpf_key structure must be passed to bpf_key_put() when done 1264 * with it, so that the key reference count is decremented and the 1265 * bpf_key structure is freed. 1266 * 1267 * Permission checks are deferred to the time the key is used by 1268 * one of the available key-specific kfuncs. 1269 * 1270 * Set *flags* with KEY_LOOKUP_CREATE, to attempt creating a requested 1271 * special keyring (e.g. session keyring), if it doesn't yet exist. 1272 * Set *flags* with KEY_LOOKUP_PARTIAL, to lookup a key without waiting 1273 * for the key construction, and to retrieve uninstantiated keys (keys 1274 * without data attached to them). 1275 * 1276 * Return: a bpf_key pointer with a valid key pointer if the key is found, a 1277 * NULL pointer otherwise. 1278 */ 1279 __bpf_kfunc struct bpf_key *bpf_lookup_user_key(u32 serial, u64 flags) 1280 { 1281 key_ref_t key_ref; 1282 struct bpf_key *bkey; 1283 1284 if (flags & ~KEY_LOOKUP_ALL) 1285 return NULL; 1286 1287 /* 1288 * Permission check is deferred until the key is used, as the 1289 * intent of the caller is unknown here. 1290 */ 1291 key_ref = lookup_user_key(serial, flags, KEY_DEFER_PERM_CHECK); 1292 if (IS_ERR(key_ref)) 1293 return NULL; 1294 1295 bkey = kmalloc(sizeof(*bkey), GFP_KERNEL); 1296 if (!bkey) { 1297 key_put(key_ref_to_ptr(key_ref)); 1298 return NULL; 1299 } 1300 1301 bkey->key = key_ref_to_ptr(key_ref); 1302 bkey->has_ref = true; 1303 1304 return bkey; 1305 } 1306 1307 /** 1308 * bpf_lookup_system_key - lookup a key by a system-defined ID 1309 * @id: key ID 1310 * 1311 * Obtain a bpf_key structure with a key pointer set to the passed key ID. 1312 * The key pointer is marked as invalid, to prevent bpf_key_put() from 1313 * attempting to decrement the key reference count on that pointer. The key 1314 * pointer set in such way is currently understood only by 1315 * verify_pkcs7_signature(). 1316 * 1317 * Set *id* to one of the values defined in include/linux/verification.h: 1318 * 0 for the primary keyring (immutable keyring of system keys); 1319 * VERIFY_USE_SECONDARY_KEYRING for both the primary and secondary keyring 1320 * (where keys can be added only if they are vouched for by existing keys 1321 * in those keyrings); VERIFY_USE_PLATFORM_KEYRING for the platform 1322 * keyring (primarily used by the integrity subsystem to verify a kexec'ed 1323 * kerned image and, possibly, the initramfs signature). 1324 * 1325 * Return: a bpf_key pointer with an invalid key pointer set from the 1326 * pre-determined ID on success, a NULL pointer otherwise 1327 */ 1328 __bpf_kfunc struct bpf_key *bpf_lookup_system_key(u64 id) 1329 { 1330 struct bpf_key *bkey; 1331 1332 if (system_keyring_id_check(id) < 0) 1333 return NULL; 1334 1335 bkey = kmalloc(sizeof(*bkey), GFP_ATOMIC); 1336 if (!bkey) 1337 return NULL; 1338 1339 bkey->key = (struct key *)(unsigned long)id; 1340 bkey->has_ref = false; 1341 1342 return bkey; 1343 } 1344 1345 /** 1346 * bpf_key_put - decrement key reference count if key is valid and free bpf_key 1347 * @bkey: bpf_key structure 1348 * 1349 * Decrement the reference count of the key inside *bkey*, if the pointer 1350 * is valid, and free *bkey*. 1351 */ 1352 __bpf_kfunc void bpf_key_put(struct bpf_key *bkey) 1353 { 1354 if (bkey->has_ref) 1355 key_put(bkey->key); 1356 1357 kfree(bkey); 1358 } 1359 1360 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION 1361 /** 1362 * bpf_verify_pkcs7_signature - verify a PKCS#7 signature 1363 * @data_p: data to verify 1364 * @sig_p: signature of the data 1365 * @trusted_keyring: keyring with keys trusted for signature verification 1366 * 1367 * Verify the PKCS#7 signature *sig_ptr* against the supplied *data_ptr* 1368 * with keys in a keyring referenced by *trusted_keyring*. 1369 * 1370 * Return: 0 on success, a negative value on error. 1371 */ 1372 __bpf_kfunc int bpf_verify_pkcs7_signature(struct bpf_dynptr *data_p, 1373 struct bpf_dynptr *sig_p, 1374 struct bpf_key *trusted_keyring) 1375 { 1376 struct bpf_dynptr_kern *data_ptr = (struct bpf_dynptr_kern *)data_p; 1377 struct bpf_dynptr_kern *sig_ptr = (struct bpf_dynptr_kern *)sig_p; 1378 const void *data, *sig; 1379 u32 data_len, sig_len; 1380 int ret; 1381 1382 if (trusted_keyring->has_ref) { 1383 /* 1384 * Do the permission check deferred in bpf_lookup_user_key(). 1385 * See bpf_lookup_user_key() for more details. 1386 * 1387 * A call to key_task_permission() here would be redundant, as 1388 * it is already done by keyring_search() called by 1389 * find_asymmetric_key(). 1390 */ 1391 ret = key_validate(trusted_keyring->key); 1392 if (ret < 0) 1393 return ret; 1394 } 1395 1396 data_len = __bpf_dynptr_size(data_ptr); 1397 data = __bpf_dynptr_data(data_ptr, data_len); 1398 sig_len = __bpf_dynptr_size(sig_ptr); 1399 sig = __bpf_dynptr_data(sig_ptr, sig_len); 1400 1401 return verify_pkcs7_signature(data, data_len, sig, sig_len, 1402 trusted_keyring->key, 1403 VERIFYING_UNSPECIFIED_SIGNATURE, NULL, 1404 NULL); 1405 } 1406 #endif /* CONFIG_SYSTEM_DATA_VERIFICATION */ 1407 1408 __bpf_kfunc_end_defs(); 1409 1410 BTF_KFUNCS_START(key_sig_kfunc_set) 1411 BTF_ID_FLAGS(func, bpf_lookup_user_key, KF_ACQUIRE | KF_RET_NULL | KF_SLEEPABLE) 1412 BTF_ID_FLAGS(func, bpf_lookup_system_key, KF_ACQUIRE | KF_RET_NULL) 1413 BTF_ID_FLAGS(func, bpf_key_put, KF_RELEASE) 1414 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION 1415 BTF_ID_FLAGS(func, bpf_verify_pkcs7_signature, KF_SLEEPABLE) 1416 #endif 1417 BTF_KFUNCS_END(key_sig_kfunc_set) 1418 1419 static const struct btf_kfunc_id_set bpf_key_sig_kfunc_set = { 1420 .owner = THIS_MODULE, 1421 .set = &key_sig_kfunc_set, 1422 }; 1423 1424 static int __init bpf_key_sig_kfuncs_init(void) 1425 { 1426 return register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, 1427 &bpf_key_sig_kfunc_set); 1428 } 1429 1430 late_initcall(bpf_key_sig_kfuncs_init); 1431 #endif /* CONFIG_KEYS */ 1432 1433 static const struct bpf_func_proto * 1434 bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1435 { 1436 const struct bpf_func_proto *func_proto; 1437 1438 switch (func_id) { 1439 case BPF_FUNC_map_lookup_elem: 1440 return &bpf_map_lookup_elem_proto; 1441 case BPF_FUNC_map_update_elem: 1442 return &bpf_map_update_elem_proto; 1443 case BPF_FUNC_map_delete_elem: 1444 return &bpf_map_delete_elem_proto; 1445 case BPF_FUNC_map_push_elem: 1446 return &bpf_map_push_elem_proto; 1447 case BPF_FUNC_map_pop_elem: 1448 return &bpf_map_pop_elem_proto; 1449 case BPF_FUNC_map_peek_elem: 1450 return &bpf_map_peek_elem_proto; 1451 case BPF_FUNC_map_lookup_percpu_elem: 1452 return &bpf_map_lookup_percpu_elem_proto; 1453 case BPF_FUNC_ktime_get_ns: 1454 return &bpf_ktime_get_ns_proto; 1455 case BPF_FUNC_ktime_get_boot_ns: 1456 return &bpf_ktime_get_boot_ns_proto; 1457 case BPF_FUNC_tail_call: 1458 return &bpf_tail_call_proto; 1459 case BPF_FUNC_get_current_task: 1460 return &bpf_get_current_task_proto; 1461 case BPF_FUNC_get_current_task_btf: 1462 return &bpf_get_current_task_btf_proto; 1463 case BPF_FUNC_task_pt_regs: 1464 return &bpf_task_pt_regs_proto; 1465 case BPF_FUNC_get_current_uid_gid: 1466 return &bpf_get_current_uid_gid_proto; 1467 case BPF_FUNC_get_current_comm: 1468 return &bpf_get_current_comm_proto; 1469 case BPF_FUNC_trace_printk: 1470 return bpf_get_trace_printk_proto(); 1471 case BPF_FUNC_get_smp_processor_id: 1472 return &bpf_get_smp_processor_id_proto; 1473 case BPF_FUNC_get_numa_node_id: 1474 return &bpf_get_numa_node_id_proto; 1475 case BPF_FUNC_perf_event_read: 1476 return &bpf_perf_event_read_proto; 1477 case BPF_FUNC_get_prandom_u32: 1478 return &bpf_get_prandom_u32_proto; 1479 case BPF_FUNC_probe_read_user: 1480 return &bpf_probe_read_user_proto; 1481 case BPF_FUNC_probe_read_kernel: 1482 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1483 NULL : &bpf_probe_read_kernel_proto; 1484 case BPF_FUNC_probe_read_user_str: 1485 return &bpf_probe_read_user_str_proto; 1486 case BPF_FUNC_probe_read_kernel_str: 1487 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1488 NULL : &bpf_probe_read_kernel_str_proto; 1489 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 1490 case BPF_FUNC_probe_read: 1491 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1492 NULL : &bpf_probe_read_compat_proto; 1493 case BPF_FUNC_probe_read_str: 1494 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1495 NULL : &bpf_probe_read_compat_str_proto; 1496 #endif 1497 #ifdef CONFIG_CGROUPS 1498 case BPF_FUNC_cgrp_storage_get: 1499 return &bpf_cgrp_storage_get_proto; 1500 case BPF_FUNC_cgrp_storage_delete: 1501 return &bpf_cgrp_storage_delete_proto; 1502 case BPF_FUNC_current_task_under_cgroup: 1503 return &bpf_current_task_under_cgroup_proto; 1504 #endif 1505 case BPF_FUNC_send_signal: 1506 return &bpf_send_signal_proto; 1507 case BPF_FUNC_send_signal_thread: 1508 return &bpf_send_signal_thread_proto; 1509 case BPF_FUNC_perf_event_read_value: 1510 return &bpf_perf_event_read_value_proto; 1511 case BPF_FUNC_ringbuf_output: 1512 return &bpf_ringbuf_output_proto; 1513 case BPF_FUNC_ringbuf_reserve: 1514 return &bpf_ringbuf_reserve_proto; 1515 case BPF_FUNC_ringbuf_submit: 1516 return &bpf_ringbuf_submit_proto; 1517 case BPF_FUNC_ringbuf_discard: 1518 return &bpf_ringbuf_discard_proto; 1519 case BPF_FUNC_ringbuf_query: 1520 return &bpf_ringbuf_query_proto; 1521 case BPF_FUNC_jiffies64: 1522 return &bpf_jiffies64_proto; 1523 case BPF_FUNC_get_task_stack: 1524 return prog->sleepable ? &bpf_get_task_stack_sleepable_proto 1525 : &bpf_get_task_stack_proto; 1526 case BPF_FUNC_copy_from_user: 1527 return &bpf_copy_from_user_proto; 1528 case BPF_FUNC_copy_from_user_task: 1529 return &bpf_copy_from_user_task_proto; 1530 case BPF_FUNC_snprintf_btf: 1531 return &bpf_snprintf_btf_proto; 1532 case BPF_FUNC_per_cpu_ptr: 1533 return &bpf_per_cpu_ptr_proto; 1534 case BPF_FUNC_this_cpu_ptr: 1535 return &bpf_this_cpu_ptr_proto; 1536 case BPF_FUNC_task_storage_get: 1537 if (bpf_prog_check_recur(prog)) 1538 return &bpf_task_storage_get_recur_proto; 1539 return &bpf_task_storage_get_proto; 1540 case BPF_FUNC_task_storage_delete: 1541 if (bpf_prog_check_recur(prog)) 1542 return &bpf_task_storage_delete_recur_proto; 1543 return &bpf_task_storage_delete_proto; 1544 case BPF_FUNC_for_each_map_elem: 1545 return &bpf_for_each_map_elem_proto; 1546 case BPF_FUNC_snprintf: 1547 return &bpf_snprintf_proto; 1548 case BPF_FUNC_get_func_ip: 1549 return &bpf_get_func_ip_proto_tracing; 1550 case BPF_FUNC_get_branch_snapshot: 1551 return &bpf_get_branch_snapshot_proto; 1552 case BPF_FUNC_find_vma: 1553 return &bpf_find_vma_proto; 1554 case BPF_FUNC_trace_vprintk: 1555 return bpf_get_trace_vprintk_proto(); 1556 default: 1557 break; 1558 } 1559 1560 func_proto = bpf_base_func_proto(func_id, prog); 1561 if (func_proto) 1562 return func_proto; 1563 1564 if (!bpf_token_capable(prog->aux->token, CAP_SYS_ADMIN)) 1565 return NULL; 1566 1567 switch (func_id) { 1568 case BPF_FUNC_probe_write_user: 1569 return security_locked_down(LOCKDOWN_BPF_WRITE_USER) < 0 ? 1570 NULL : &bpf_probe_write_user_proto; 1571 default: 1572 return NULL; 1573 } 1574 } 1575 1576 static bool is_kprobe_multi(const struct bpf_prog *prog) 1577 { 1578 return prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI || 1579 prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION; 1580 } 1581 1582 static inline bool is_kprobe_session(const struct bpf_prog *prog) 1583 { 1584 return prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION; 1585 } 1586 1587 static inline bool is_uprobe_multi(const struct bpf_prog *prog) 1588 { 1589 return prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI || 1590 prog->expected_attach_type == BPF_TRACE_UPROBE_SESSION; 1591 } 1592 1593 static inline bool is_uprobe_session(const struct bpf_prog *prog) 1594 { 1595 return prog->expected_attach_type == BPF_TRACE_UPROBE_SESSION; 1596 } 1597 1598 static const struct bpf_func_proto * 1599 kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1600 { 1601 switch (func_id) { 1602 case BPF_FUNC_perf_event_output: 1603 return &bpf_perf_event_output_proto; 1604 case BPF_FUNC_get_stackid: 1605 return &bpf_get_stackid_proto; 1606 case BPF_FUNC_get_stack: 1607 return prog->sleepable ? &bpf_get_stack_sleepable_proto : &bpf_get_stack_proto; 1608 #ifdef CONFIG_BPF_KPROBE_OVERRIDE 1609 case BPF_FUNC_override_return: 1610 return &bpf_override_return_proto; 1611 #endif 1612 case BPF_FUNC_get_func_ip: 1613 if (is_kprobe_multi(prog)) 1614 return &bpf_get_func_ip_proto_kprobe_multi; 1615 if (is_uprobe_multi(prog)) 1616 return &bpf_get_func_ip_proto_uprobe_multi; 1617 return &bpf_get_func_ip_proto_kprobe; 1618 case BPF_FUNC_get_attach_cookie: 1619 if (is_kprobe_multi(prog)) 1620 return &bpf_get_attach_cookie_proto_kmulti; 1621 if (is_uprobe_multi(prog)) 1622 return &bpf_get_attach_cookie_proto_umulti; 1623 return &bpf_get_attach_cookie_proto_trace; 1624 default: 1625 return bpf_tracing_func_proto(func_id, prog); 1626 } 1627 } 1628 1629 /* bpf+kprobe programs can access fields of 'struct pt_regs' */ 1630 static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type, 1631 const struct bpf_prog *prog, 1632 struct bpf_insn_access_aux *info) 1633 { 1634 if (off < 0 || off >= sizeof(struct pt_regs)) 1635 return false; 1636 if (type != BPF_READ) 1637 return false; 1638 if (off % size != 0) 1639 return false; 1640 /* 1641 * Assertion for 32 bit to make sure last 8 byte access 1642 * (BPF_DW) to the last 4 byte member is disallowed. 1643 */ 1644 if (off + size > sizeof(struct pt_regs)) 1645 return false; 1646 1647 return true; 1648 } 1649 1650 const struct bpf_verifier_ops kprobe_verifier_ops = { 1651 .get_func_proto = kprobe_prog_func_proto, 1652 .is_valid_access = kprobe_prog_is_valid_access, 1653 }; 1654 1655 const struct bpf_prog_ops kprobe_prog_ops = { 1656 }; 1657 1658 BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map, 1659 u64, flags, void *, data, u64, size) 1660 { 1661 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1662 1663 /* 1664 * r1 points to perf tracepoint buffer where first 8 bytes are hidden 1665 * from bpf program and contain a pointer to 'struct pt_regs'. Fetch it 1666 * from there and call the same bpf_perf_event_output() helper inline. 1667 */ 1668 return ____bpf_perf_event_output(regs, map, flags, data, size); 1669 } 1670 1671 static const struct bpf_func_proto bpf_perf_event_output_proto_tp = { 1672 .func = bpf_perf_event_output_tp, 1673 .gpl_only = true, 1674 .ret_type = RET_INTEGER, 1675 .arg1_type = ARG_PTR_TO_CTX, 1676 .arg2_type = ARG_CONST_MAP_PTR, 1677 .arg3_type = ARG_ANYTHING, 1678 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1679 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 1680 }; 1681 1682 BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map, 1683 u64, flags) 1684 { 1685 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1686 1687 /* 1688 * Same comment as in bpf_perf_event_output_tp(), only that this time 1689 * the other helper's function body cannot be inlined due to being 1690 * external, thus we need to call raw helper function. 1691 */ 1692 return bpf_get_stackid((unsigned long) regs, (unsigned long) map, 1693 flags, 0, 0); 1694 } 1695 1696 static const struct bpf_func_proto bpf_get_stackid_proto_tp = { 1697 .func = bpf_get_stackid_tp, 1698 .gpl_only = true, 1699 .ret_type = RET_INTEGER, 1700 .arg1_type = ARG_PTR_TO_CTX, 1701 .arg2_type = ARG_CONST_MAP_PTR, 1702 .arg3_type = ARG_ANYTHING, 1703 }; 1704 1705 BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size, 1706 u64, flags) 1707 { 1708 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1709 1710 return bpf_get_stack((unsigned long) regs, (unsigned long) buf, 1711 (unsigned long) size, flags, 0); 1712 } 1713 1714 static const struct bpf_func_proto bpf_get_stack_proto_tp = { 1715 .func = bpf_get_stack_tp, 1716 .gpl_only = true, 1717 .ret_type = RET_INTEGER, 1718 .arg1_type = ARG_PTR_TO_CTX, 1719 .arg2_type = ARG_PTR_TO_UNINIT_MEM, 1720 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1721 .arg4_type = ARG_ANYTHING, 1722 }; 1723 1724 static const struct bpf_func_proto * 1725 tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1726 { 1727 switch (func_id) { 1728 case BPF_FUNC_perf_event_output: 1729 return &bpf_perf_event_output_proto_tp; 1730 case BPF_FUNC_get_stackid: 1731 return &bpf_get_stackid_proto_tp; 1732 case BPF_FUNC_get_stack: 1733 return &bpf_get_stack_proto_tp; 1734 case BPF_FUNC_get_attach_cookie: 1735 return &bpf_get_attach_cookie_proto_trace; 1736 default: 1737 return bpf_tracing_func_proto(func_id, prog); 1738 } 1739 } 1740 1741 static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type, 1742 const struct bpf_prog *prog, 1743 struct bpf_insn_access_aux *info) 1744 { 1745 if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE) 1746 return false; 1747 if (type != BPF_READ) 1748 return false; 1749 if (off % size != 0) 1750 return false; 1751 1752 BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(__u64)); 1753 return true; 1754 } 1755 1756 const struct bpf_verifier_ops tracepoint_verifier_ops = { 1757 .get_func_proto = tp_prog_func_proto, 1758 .is_valid_access = tp_prog_is_valid_access, 1759 }; 1760 1761 const struct bpf_prog_ops tracepoint_prog_ops = { 1762 }; 1763 1764 BPF_CALL_3(bpf_perf_prog_read_value, struct bpf_perf_event_data_kern *, ctx, 1765 struct bpf_perf_event_value *, buf, u32, size) 1766 { 1767 int err = -EINVAL; 1768 1769 if (unlikely(size != sizeof(struct bpf_perf_event_value))) 1770 goto clear; 1771 err = perf_event_read_local(ctx->event, &buf->counter, &buf->enabled, 1772 &buf->running); 1773 if (unlikely(err)) 1774 goto clear; 1775 return 0; 1776 clear: 1777 memset(buf, 0, size); 1778 return err; 1779 } 1780 1781 static const struct bpf_func_proto bpf_perf_prog_read_value_proto = { 1782 .func = bpf_perf_prog_read_value, 1783 .gpl_only = true, 1784 .ret_type = RET_INTEGER, 1785 .arg1_type = ARG_PTR_TO_CTX, 1786 .arg2_type = ARG_PTR_TO_UNINIT_MEM, 1787 .arg3_type = ARG_CONST_SIZE, 1788 }; 1789 1790 BPF_CALL_4(bpf_read_branch_records, struct bpf_perf_event_data_kern *, ctx, 1791 void *, buf, u32, size, u64, flags) 1792 { 1793 static const u32 br_entry_size = sizeof(struct perf_branch_entry); 1794 struct perf_branch_stack *br_stack = ctx->data->br_stack; 1795 u32 to_copy; 1796 1797 if (unlikely(flags & ~BPF_F_GET_BRANCH_RECORDS_SIZE)) 1798 return -EINVAL; 1799 1800 if (unlikely(!(ctx->data->sample_flags & PERF_SAMPLE_BRANCH_STACK))) 1801 return -ENOENT; 1802 1803 if (unlikely(!br_stack)) 1804 return -ENOENT; 1805 1806 if (flags & BPF_F_GET_BRANCH_RECORDS_SIZE) 1807 return br_stack->nr * br_entry_size; 1808 1809 if (!buf || (size % br_entry_size != 0)) 1810 return -EINVAL; 1811 1812 to_copy = min_t(u32, br_stack->nr * br_entry_size, size); 1813 memcpy(buf, br_stack->entries, to_copy); 1814 1815 return to_copy; 1816 } 1817 1818 static const struct bpf_func_proto bpf_read_branch_records_proto = { 1819 .func = bpf_read_branch_records, 1820 .gpl_only = true, 1821 .ret_type = RET_INTEGER, 1822 .arg1_type = ARG_PTR_TO_CTX, 1823 .arg2_type = ARG_PTR_TO_MEM_OR_NULL, 1824 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1825 .arg4_type = ARG_ANYTHING, 1826 }; 1827 1828 static const struct bpf_func_proto * 1829 pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1830 { 1831 switch (func_id) { 1832 case BPF_FUNC_perf_event_output: 1833 return &bpf_perf_event_output_proto_tp; 1834 case BPF_FUNC_get_stackid: 1835 return &bpf_get_stackid_proto_pe; 1836 case BPF_FUNC_get_stack: 1837 return &bpf_get_stack_proto_pe; 1838 case BPF_FUNC_perf_prog_read_value: 1839 return &bpf_perf_prog_read_value_proto; 1840 case BPF_FUNC_read_branch_records: 1841 return &bpf_read_branch_records_proto; 1842 case BPF_FUNC_get_attach_cookie: 1843 return &bpf_get_attach_cookie_proto_pe; 1844 default: 1845 return bpf_tracing_func_proto(func_id, prog); 1846 } 1847 } 1848 1849 /* 1850 * bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp 1851 * to avoid potential recursive reuse issue when/if tracepoints are added 1852 * inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack. 1853 * 1854 * Since raw tracepoints run despite bpf_prog_active, support concurrent usage 1855 * in normal, irq, and nmi context. 1856 */ 1857 struct bpf_raw_tp_regs { 1858 struct pt_regs regs[3]; 1859 }; 1860 static DEFINE_PER_CPU(struct bpf_raw_tp_regs, bpf_raw_tp_regs); 1861 static DEFINE_PER_CPU(int, bpf_raw_tp_nest_level); 1862 static struct pt_regs *get_bpf_raw_tp_regs(void) 1863 { 1864 struct bpf_raw_tp_regs *tp_regs = this_cpu_ptr(&bpf_raw_tp_regs); 1865 int nest_level = this_cpu_inc_return(bpf_raw_tp_nest_level); 1866 1867 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(tp_regs->regs))) { 1868 this_cpu_dec(bpf_raw_tp_nest_level); 1869 return ERR_PTR(-EBUSY); 1870 } 1871 1872 return &tp_regs->regs[nest_level - 1]; 1873 } 1874 1875 static void put_bpf_raw_tp_regs(void) 1876 { 1877 this_cpu_dec(bpf_raw_tp_nest_level); 1878 } 1879 1880 BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args, 1881 struct bpf_map *, map, u64, flags, void *, data, u64, size) 1882 { 1883 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1884 int ret; 1885 1886 if (IS_ERR(regs)) 1887 return PTR_ERR(regs); 1888 1889 perf_fetch_caller_regs(regs); 1890 ret = ____bpf_perf_event_output(regs, map, flags, data, size); 1891 1892 put_bpf_raw_tp_regs(); 1893 return ret; 1894 } 1895 1896 static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = { 1897 .func = bpf_perf_event_output_raw_tp, 1898 .gpl_only = true, 1899 .ret_type = RET_INTEGER, 1900 .arg1_type = ARG_PTR_TO_CTX, 1901 .arg2_type = ARG_CONST_MAP_PTR, 1902 .arg3_type = ARG_ANYTHING, 1903 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1904 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 1905 }; 1906 1907 extern const struct bpf_func_proto bpf_skb_output_proto; 1908 extern const struct bpf_func_proto bpf_xdp_output_proto; 1909 extern const struct bpf_func_proto bpf_xdp_get_buff_len_trace_proto; 1910 1911 BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args, 1912 struct bpf_map *, map, u64, flags) 1913 { 1914 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1915 int ret; 1916 1917 if (IS_ERR(regs)) 1918 return PTR_ERR(regs); 1919 1920 perf_fetch_caller_regs(regs); 1921 /* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */ 1922 ret = bpf_get_stackid((unsigned long) regs, (unsigned long) map, 1923 flags, 0, 0); 1924 put_bpf_raw_tp_regs(); 1925 return ret; 1926 } 1927 1928 static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = { 1929 .func = bpf_get_stackid_raw_tp, 1930 .gpl_only = true, 1931 .ret_type = RET_INTEGER, 1932 .arg1_type = ARG_PTR_TO_CTX, 1933 .arg2_type = ARG_CONST_MAP_PTR, 1934 .arg3_type = ARG_ANYTHING, 1935 }; 1936 1937 BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args, 1938 void *, buf, u32, size, u64, flags) 1939 { 1940 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1941 int ret; 1942 1943 if (IS_ERR(regs)) 1944 return PTR_ERR(regs); 1945 1946 perf_fetch_caller_regs(regs); 1947 ret = bpf_get_stack((unsigned long) regs, (unsigned long) buf, 1948 (unsigned long) size, flags, 0); 1949 put_bpf_raw_tp_regs(); 1950 return ret; 1951 } 1952 1953 static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = { 1954 .func = bpf_get_stack_raw_tp, 1955 .gpl_only = true, 1956 .ret_type = RET_INTEGER, 1957 .arg1_type = ARG_PTR_TO_CTX, 1958 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1959 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1960 .arg4_type = ARG_ANYTHING, 1961 }; 1962 1963 static const struct bpf_func_proto * 1964 raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1965 { 1966 switch (func_id) { 1967 case BPF_FUNC_perf_event_output: 1968 return &bpf_perf_event_output_proto_raw_tp; 1969 case BPF_FUNC_get_stackid: 1970 return &bpf_get_stackid_proto_raw_tp; 1971 case BPF_FUNC_get_stack: 1972 return &bpf_get_stack_proto_raw_tp; 1973 case BPF_FUNC_get_attach_cookie: 1974 return &bpf_get_attach_cookie_proto_tracing; 1975 default: 1976 return bpf_tracing_func_proto(func_id, prog); 1977 } 1978 } 1979 1980 const struct bpf_func_proto * 1981 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1982 { 1983 const struct bpf_func_proto *fn; 1984 1985 switch (func_id) { 1986 #ifdef CONFIG_NET 1987 case BPF_FUNC_skb_output: 1988 return &bpf_skb_output_proto; 1989 case BPF_FUNC_xdp_output: 1990 return &bpf_xdp_output_proto; 1991 case BPF_FUNC_skc_to_tcp6_sock: 1992 return &bpf_skc_to_tcp6_sock_proto; 1993 case BPF_FUNC_skc_to_tcp_sock: 1994 return &bpf_skc_to_tcp_sock_proto; 1995 case BPF_FUNC_skc_to_tcp_timewait_sock: 1996 return &bpf_skc_to_tcp_timewait_sock_proto; 1997 case BPF_FUNC_skc_to_tcp_request_sock: 1998 return &bpf_skc_to_tcp_request_sock_proto; 1999 case BPF_FUNC_skc_to_udp6_sock: 2000 return &bpf_skc_to_udp6_sock_proto; 2001 case BPF_FUNC_skc_to_unix_sock: 2002 return &bpf_skc_to_unix_sock_proto; 2003 case BPF_FUNC_skc_to_mptcp_sock: 2004 return &bpf_skc_to_mptcp_sock_proto; 2005 case BPF_FUNC_sk_storage_get: 2006 return &bpf_sk_storage_get_tracing_proto; 2007 case BPF_FUNC_sk_storage_delete: 2008 return &bpf_sk_storage_delete_tracing_proto; 2009 case BPF_FUNC_sock_from_file: 2010 return &bpf_sock_from_file_proto; 2011 case BPF_FUNC_get_socket_cookie: 2012 return &bpf_get_socket_ptr_cookie_proto; 2013 case BPF_FUNC_xdp_get_buff_len: 2014 return &bpf_xdp_get_buff_len_trace_proto; 2015 #endif 2016 case BPF_FUNC_seq_printf: 2017 return prog->expected_attach_type == BPF_TRACE_ITER ? 2018 &bpf_seq_printf_proto : 2019 NULL; 2020 case BPF_FUNC_seq_write: 2021 return prog->expected_attach_type == BPF_TRACE_ITER ? 2022 &bpf_seq_write_proto : 2023 NULL; 2024 case BPF_FUNC_seq_printf_btf: 2025 return prog->expected_attach_type == BPF_TRACE_ITER ? 2026 &bpf_seq_printf_btf_proto : 2027 NULL; 2028 case BPF_FUNC_d_path: 2029 return &bpf_d_path_proto; 2030 case BPF_FUNC_get_func_arg: 2031 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_proto : NULL; 2032 case BPF_FUNC_get_func_ret: 2033 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_ret_proto : NULL; 2034 case BPF_FUNC_get_func_arg_cnt: 2035 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_cnt_proto : NULL; 2036 case BPF_FUNC_get_attach_cookie: 2037 if (prog->type == BPF_PROG_TYPE_TRACING && 2038 prog->expected_attach_type == BPF_TRACE_RAW_TP) 2039 return &bpf_get_attach_cookie_proto_tracing; 2040 return bpf_prog_has_trampoline(prog) ? &bpf_get_attach_cookie_proto_tracing : NULL; 2041 default: 2042 fn = raw_tp_prog_func_proto(func_id, prog); 2043 if (!fn && prog->expected_attach_type == BPF_TRACE_ITER) 2044 fn = bpf_iter_get_func_proto(func_id, prog); 2045 return fn; 2046 } 2047 } 2048 2049 static bool raw_tp_prog_is_valid_access(int off, int size, 2050 enum bpf_access_type type, 2051 const struct bpf_prog *prog, 2052 struct bpf_insn_access_aux *info) 2053 { 2054 return bpf_tracing_ctx_access(off, size, type); 2055 } 2056 2057 static bool tracing_prog_is_valid_access(int off, int size, 2058 enum bpf_access_type type, 2059 const struct bpf_prog *prog, 2060 struct bpf_insn_access_aux *info) 2061 { 2062 return bpf_tracing_btf_ctx_access(off, size, type, prog, info); 2063 } 2064 2065 int __weak bpf_prog_test_run_tracing(struct bpf_prog *prog, 2066 const union bpf_attr *kattr, 2067 union bpf_attr __user *uattr) 2068 { 2069 return -ENOTSUPP; 2070 } 2071 2072 const struct bpf_verifier_ops raw_tracepoint_verifier_ops = { 2073 .get_func_proto = raw_tp_prog_func_proto, 2074 .is_valid_access = raw_tp_prog_is_valid_access, 2075 }; 2076 2077 const struct bpf_prog_ops raw_tracepoint_prog_ops = { 2078 #ifdef CONFIG_NET 2079 .test_run = bpf_prog_test_run_raw_tp, 2080 #endif 2081 }; 2082 2083 const struct bpf_verifier_ops tracing_verifier_ops = { 2084 .get_func_proto = tracing_prog_func_proto, 2085 .is_valid_access = tracing_prog_is_valid_access, 2086 }; 2087 2088 const struct bpf_prog_ops tracing_prog_ops = { 2089 .test_run = bpf_prog_test_run_tracing, 2090 }; 2091 2092 static bool raw_tp_writable_prog_is_valid_access(int off, int size, 2093 enum bpf_access_type type, 2094 const struct bpf_prog *prog, 2095 struct bpf_insn_access_aux *info) 2096 { 2097 if (off == 0) { 2098 if (size != sizeof(u64) || type != BPF_READ) 2099 return false; 2100 info->reg_type = PTR_TO_TP_BUFFER; 2101 } 2102 return raw_tp_prog_is_valid_access(off, size, type, prog, info); 2103 } 2104 2105 const struct bpf_verifier_ops raw_tracepoint_writable_verifier_ops = { 2106 .get_func_proto = raw_tp_prog_func_proto, 2107 .is_valid_access = raw_tp_writable_prog_is_valid_access, 2108 }; 2109 2110 const struct bpf_prog_ops raw_tracepoint_writable_prog_ops = { 2111 }; 2112 2113 static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type, 2114 const struct bpf_prog *prog, 2115 struct bpf_insn_access_aux *info) 2116 { 2117 const int size_u64 = sizeof(u64); 2118 2119 if (off < 0 || off >= sizeof(struct bpf_perf_event_data)) 2120 return false; 2121 if (type != BPF_READ) 2122 return false; 2123 if (off % size != 0) { 2124 if (sizeof(unsigned long) != 4) 2125 return false; 2126 if (size != 8) 2127 return false; 2128 if (off % size != 4) 2129 return false; 2130 } 2131 2132 switch (off) { 2133 case bpf_ctx_range(struct bpf_perf_event_data, sample_period): 2134 bpf_ctx_record_field_size(info, size_u64); 2135 if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) 2136 return false; 2137 break; 2138 case bpf_ctx_range(struct bpf_perf_event_data, addr): 2139 bpf_ctx_record_field_size(info, size_u64); 2140 if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) 2141 return false; 2142 break; 2143 default: 2144 if (size != sizeof(long)) 2145 return false; 2146 } 2147 2148 return true; 2149 } 2150 2151 static u32 pe_prog_convert_ctx_access(enum bpf_access_type type, 2152 const struct bpf_insn *si, 2153 struct bpf_insn *insn_buf, 2154 struct bpf_prog *prog, u32 *target_size) 2155 { 2156 struct bpf_insn *insn = insn_buf; 2157 2158 switch (si->off) { 2159 case offsetof(struct bpf_perf_event_data, sample_period): 2160 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 2161 data), si->dst_reg, si->src_reg, 2162 offsetof(struct bpf_perf_event_data_kern, data)); 2163 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, 2164 bpf_target_off(struct perf_sample_data, period, 8, 2165 target_size)); 2166 break; 2167 case offsetof(struct bpf_perf_event_data, addr): 2168 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 2169 data), si->dst_reg, si->src_reg, 2170 offsetof(struct bpf_perf_event_data_kern, data)); 2171 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, 2172 bpf_target_off(struct perf_sample_data, addr, 8, 2173 target_size)); 2174 break; 2175 default: 2176 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 2177 regs), si->dst_reg, si->src_reg, 2178 offsetof(struct bpf_perf_event_data_kern, regs)); 2179 *insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg, 2180 si->off); 2181 break; 2182 } 2183 2184 return insn - insn_buf; 2185 } 2186 2187 const struct bpf_verifier_ops perf_event_verifier_ops = { 2188 .get_func_proto = pe_prog_func_proto, 2189 .is_valid_access = pe_prog_is_valid_access, 2190 .convert_ctx_access = pe_prog_convert_ctx_access, 2191 }; 2192 2193 const struct bpf_prog_ops perf_event_prog_ops = { 2194 }; 2195 2196 static DEFINE_MUTEX(bpf_event_mutex); 2197 2198 #define BPF_TRACE_MAX_PROGS 64 2199 2200 int perf_event_attach_bpf_prog(struct perf_event *event, 2201 struct bpf_prog *prog, 2202 u64 bpf_cookie) 2203 { 2204 struct bpf_prog_array *old_array; 2205 struct bpf_prog_array *new_array; 2206 int ret = -EEXIST; 2207 2208 /* 2209 * Kprobe override only works if they are on the function entry, 2210 * and only if they are on the opt-in list. 2211 */ 2212 if (prog->kprobe_override && 2213 (!trace_kprobe_on_func_entry(event->tp_event) || 2214 !trace_kprobe_error_injectable(event->tp_event))) 2215 return -EINVAL; 2216 2217 mutex_lock(&bpf_event_mutex); 2218 2219 if (event->prog) 2220 goto unlock; 2221 2222 old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); 2223 if (old_array && 2224 bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) { 2225 ret = -E2BIG; 2226 goto unlock; 2227 } 2228 2229 ret = bpf_prog_array_copy(old_array, NULL, prog, bpf_cookie, &new_array); 2230 if (ret < 0) 2231 goto unlock; 2232 2233 /* set the new array to event->tp_event and set event->prog */ 2234 event->prog = prog; 2235 event->bpf_cookie = bpf_cookie; 2236 rcu_assign_pointer(event->tp_event->prog_array, new_array); 2237 bpf_prog_array_free_sleepable(old_array); 2238 2239 unlock: 2240 mutex_unlock(&bpf_event_mutex); 2241 return ret; 2242 } 2243 2244 void perf_event_detach_bpf_prog(struct perf_event *event) 2245 { 2246 struct bpf_prog_array *old_array; 2247 struct bpf_prog_array *new_array; 2248 int ret; 2249 2250 mutex_lock(&bpf_event_mutex); 2251 2252 if (!event->prog) 2253 goto unlock; 2254 2255 old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); 2256 ret = bpf_prog_array_copy(old_array, event->prog, NULL, 0, &new_array); 2257 if (ret < 0) { 2258 bpf_prog_array_delete_safe(old_array, event->prog); 2259 } else { 2260 rcu_assign_pointer(event->tp_event->prog_array, new_array); 2261 bpf_prog_array_free_sleepable(old_array); 2262 } 2263 2264 bpf_prog_put(event->prog); 2265 event->prog = NULL; 2266 2267 unlock: 2268 mutex_unlock(&bpf_event_mutex); 2269 } 2270 2271 int perf_event_query_prog_array(struct perf_event *event, void __user *info) 2272 { 2273 struct perf_event_query_bpf __user *uquery = info; 2274 struct perf_event_query_bpf query = {}; 2275 struct bpf_prog_array *progs; 2276 u32 *ids, prog_cnt, ids_len; 2277 int ret; 2278 2279 if (!perfmon_capable()) 2280 return -EPERM; 2281 if (event->attr.type != PERF_TYPE_TRACEPOINT) 2282 return -EINVAL; 2283 if (copy_from_user(&query, uquery, sizeof(query))) 2284 return -EFAULT; 2285 2286 ids_len = query.ids_len; 2287 if (ids_len > BPF_TRACE_MAX_PROGS) 2288 return -E2BIG; 2289 ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN); 2290 if (!ids) 2291 return -ENOMEM; 2292 /* 2293 * The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which 2294 * is required when user only wants to check for uquery->prog_cnt. 2295 * There is no need to check for it since the case is handled 2296 * gracefully in bpf_prog_array_copy_info. 2297 */ 2298 2299 mutex_lock(&bpf_event_mutex); 2300 progs = bpf_event_rcu_dereference(event->tp_event->prog_array); 2301 ret = bpf_prog_array_copy_info(progs, ids, ids_len, &prog_cnt); 2302 mutex_unlock(&bpf_event_mutex); 2303 2304 if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) || 2305 copy_to_user(uquery->ids, ids, ids_len * sizeof(u32))) 2306 ret = -EFAULT; 2307 2308 kfree(ids); 2309 return ret; 2310 } 2311 2312 extern struct bpf_raw_event_map __start__bpf_raw_tp[]; 2313 extern struct bpf_raw_event_map __stop__bpf_raw_tp[]; 2314 2315 struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name) 2316 { 2317 struct bpf_raw_event_map *btp = __start__bpf_raw_tp; 2318 2319 for (; btp < __stop__bpf_raw_tp; btp++) { 2320 if (!strcmp(btp->tp->name, name)) 2321 return btp; 2322 } 2323 2324 return bpf_get_raw_tracepoint_module(name); 2325 } 2326 2327 void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp) 2328 { 2329 struct module *mod; 2330 2331 preempt_disable(); 2332 mod = __module_address((unsigned long)btp); 2333 module_put(mod); 2334 preempt_enable(); 2335 } 2336 2337 static __always_inline 2338 void __bpf_trace_run(struct bpf_raw_tp_link *link, u64 *args) 2339 { 2340 struct bpf_prog *prog = link->link.prog; 2341 struct bpf_run_ctx *old_run_ctx; 2342 struct bpf_trace_run_ctx run_ctx; 2343 2344 cant_sleep(); 2345 if (unlikely(this_cpu_inc_return(*(prog->active)) != 1)) { 2346 bpf_prog_inc_misses_counter(prog); 2347 goto out; 2348 } 2349 2350 run_ctx.bpf_cookie = link->cookie; 2351 old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx); 2352 2353 rcu_read_lock(); 2354 (void) bpf_prog_run(prog, args); 2355 rcu_read_unlock(); 2356 2357 bpf_reset_run_ctx(old_run_ctx); 2358 out: 2359 this_cpu_dec(*(prog->active)); 2360 } 2361 2362 #define UNPACK(...) __VA_ARGS__ 2363 #define REPEAT_1(FN, DL, X, ...) FN(X) 2364 #define REPEAT_2(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__) 2365 #define REPEAT_3(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_2(FN, DL, __VA_ARGS__) 2366 #define REPEAT_4(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_3(FN, DL, __VA_ARGS__) 2367 #define REPEAT_5(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_4(FN, DL, __VA_ARGS__) 2368 #define REPEAT_6(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_5(FN, DL, __VA_ARGS__) 2369 #define REPEAT_7(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_6(FN, DL, __VA_ARGS__) 2370 #define REPEAT_8(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_7(FN, DL, __VA_ARGS__) 2371 #define REPEAT_9(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_8(FN, DL, __VA_ARGS__) 2372 #define REPEAT_10(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_9(FN, DL, __VA_ARGS__) 2373 #define REPEAT_11(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_10(FN, DL, __VA_ARGS__) 2374 #define REPEAT_12(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_11(FN, DL, __VA_ARGS__) 2375 #define REPEAT(X, FN, DL, ...) REPEAT_##X(FN, DL, __VA_ARGS__) 2376 2377 #define SARG(X) u64 arg##X 2378 #define COPY(X) args[X] = arg##X 2379 2380 #define __DL_COM (,) 2381 #define __DL_SEM (;) 2382 2383 #define __SEQ_0_11 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 2384 2385 #define BPF_TRACE_DEFN_x(x) \ 2386 void bpf_trace_run##x(struct bpf_raw_tp_link *link, \ 2387 REPEAT(x, SARG, __DL_COM, __SEQ_0_11)) \ 2388 { \ 2389 u64 args[x]; \ 2390 REPEAT(x, COPY, __DL_SEM, __SEQ_0_11); \ 2391 __bpf_trace_run(link, args); \ 2392 } \ 2393 EXPORT_SYMBOL_GPL(bpf_trace_run##x) 2394 BPF_TRACE_DEFN_x(1); 2395 BPF_TRACE_DEFN_x(2); 2396 BPF_TRACE_DEFN_x(3); 2397 BPF_TRACE_DEFN_x(4); 2398 BPF_TRACE_DEFN_x(5); 2399 BPF_TRACE_DEFN_x(6); 2400 BPF_TRACE_DEFN_x(7); 2401 BPF_TRACE_DEFN_x(8); 2402 BPF_TRACE_DEFN_x(9); 2403 BPF_TRACE_DEFN_x(10); 2404 BPF_TRACE_DEFN_x(11); 2405 BPF_TRACE_DEFN_x(12); 2406 2407 int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_raw_tp_link *link) 2408 { 2409 struct tracepoint *tp = btp->tp; 2410 struct bpf_prog *prog = link->link.prog; 2411 2412 /* 2413 * check that program doesn't access arguments beyond what's 2414 * available in this tracepoint 2415 */ 2416 if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64)) 2417 return -EINVAL; 2418 2419 if (prog->aux->max_tp_access > btp->writable_size) 2420 return -EINVAL; 2421 2422 return tracepoint_probe_register_may_exist(tp, (void *)btp->bpf_func, link); 2423 } 2424 2425 int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_raw_tp_link *link) 2426 { 2427 return tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, link); 2428 } 2429 2430 int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id, 2431 u32 *fd_type, const char **buf, 2432 u64 *probe_offset, u64 *probe_addr, 2433 unsigned long *missed) 2434 { 2435 bool is_tracepoint, is_syscall_tp; 2436 struct bpf_prog *prog; 2437 int flags, err = 0; 2438 2439 prog = event->prog; 2440 if (!prog) 2441 return -ENOENT; 2442 2443 /* not supporting BPF_PROG_TYPE_PERF_EVENT yet */ 2444 if (prog->type == BPF_PROG_TYPE_PERF_EVENT) 2445 return -EOPNOTSUPP; 2446 2447 *prog_id = prog->aux->id; 2448 flags = event->tp_event->flags; 2449 is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT; 2450 is_syscall_tp = is_syscall_trace_event(event->tp_event); 2451 2452 if (is_tracepoint || is_syscall_tp) { 2453 *buf = is_tracepoint ? event->tp_event->tp->name 2454 : event->tp_event->name; 2455 /* We allow NULL pointer for tracepoint */ 2456 if (fd_type) 2457 *fd_type = BPF_FD_TYPE_TRACEPOINT; 2458 if (probe_offset) 2459 *probe_offset = 0x0; 2460 if (probe_addr) 2461 *probe_addr = 0x0; 2462 } else { 2463 /* kprobe/uprobe */ 2464 err = -EOPNOTSUPP; 2465 #ifdef CONFIG_KPROBE_EVENTS 2466 if (flags & TRACE_EVENT_FL_KPROBE) 2467 err = bpf_get_kprobe_info(event, fd_type, buf, 2468 probe_offset, probe_addr, missed, 2469 event->attr.type == PERF_TYPE_TRACEPOINT); 2470 #endif 2471 #ifdef CONFIG_UPROBE_EVENTS 2472 if (flags & TRACE_EVENT_FL_UPROBE) 2473 err = bpf_get_uprobe_info(event, fd_type, buf, 2474 probe_offset, probe_addr, 2475 event->attr.type == PERF_TYPE_TRACEPOINT); 2476 #endif 2477 } 2478 2479 return err; 2480 } 2481 2482 static int __init send_signal_irq_work_init(void) 2483 { 2484 int cpu; 2485 struct send_signal_irq_work *work; 2486 2487 for_each_possible_cpu(cpu) { 2488 work = per_cpu_ptr(&send_signal_work, cpu); 2489 init_irq_work(&work->irq_work, do_bpf_send_signal); 2490 } 2491 return 0; 2492 } 2493 2494 subsys_initcall(send_signal_irq_work_init); 2495 2496 #ifdef CONFIG_MODULES 2497 static int bpf_event_notify(struct notifier_block *nb, unsigned long op, 2498 void *module) 2499 { 2500 struct bpf_trace_module *btm, *tmp; 2501 struct module *mod = module; 2502 int ret = 0; 2503 2504 if (mod->num_bpf_raw_events == 0 || 2505 (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING)) 2506 goto out; 2507 2508 mutex_lock(&bpf_module_mutex); 2509 2510 switch (op) { 2511 case MODULE_STATE_COMING: 2512 btm = kzalloc(sizeof(*btm), GFP_KERNEL); 2513 if (btm) { 2514 btm->module = module; 2515 list_add(&btm->list, &bpf_trace_modules); 2516 } else { 2517 ret = -ENOMEM; 2518 } 2519 break; 2520 case MODULE_STATE_GOING: 2521 list_for_each_entry_safe(btm, tmp, &bpf_trace_modules, list) { 2522 if (btm->module == module) { 2523 list_del(&btm->list); 2524 kfree(btm); 2525 break; 2526 } 2527 } 2528 break; 2529 } 2530 2531 mutex_unlock(&bpf_module_mutex); 2532 2533 out: 2534 return notifier_from_errno(ret); 2535 } 2536 2537 static struct notifier_block bpf_module_nb = { 2538 .notifier_call = bpf_event_notify, 2539 }; 2540 2541 static int __init bpf_event_init(void) 2542 { 2543 register_module_notifier(&bpf_module_nb); 2544 return 0; 2545 } 2546 2547 fs_initcall(bpf_event_init); 2548 #endif /* CONFIG_MODULES */ 2549 2550 struct bpf_session_run_ctx { 2551 struct bpf_run_ctx run_ctx; 2552 bool is_return; 2553 void *data; 2554 }; 2555 2556 #ifdef CONFIG_FPROBE 2557 struct bpf_kprobe_multi_link { 2558 struct bpf_link link; 2559 struct fprobe fp; 2560 unsigned long *addrs; 2561 u64 *cookies; 2562 u32 cnt; 2563 u32 mods_cnt; 2564 struct module **mods; 2565 u32 flags; 2566 }; 2567 2568 struct bpf_kprobe_multi_run_ctx { 2569 struct bpf_session_run_ctx session_ctx; 2570 struct bpf_kprobe_multi_link *link; 2571 unsigned long entry_ip; 2572 }; 2573 2574 struct user_syms { 2575 const char **syms; 2576 char *buf; 2577 }; 2578 2579 static int copy_user_syms(struct user_syms *us, unsigned long __user *usyms, u32 cnt) 2580 { 2581 unsigned long __user usymbol; 2582 const char **syms = NULL; 2583 char *buf = NULL, *p; 2584 int err = -ENOMEM; 2585 unsigned int i; 2586 2587 syms = kvmalloc_array(cnt, sizeof(*syms), GFP_KERNEL); 2588 if (!syms) 2589 goto error; 2590 2591 buf = kvmalloc_array(cnt, KSYM_NAME_LEN, GFP_KERNEL); 2592 if (!buf) 2593 goto error; 2594 2595 for (p = buf, i = 0; i < cnt; i++) { 2596 if (__get_user(usymbol, usyms + i)) { 2597 err = -EFAULT; 2598 goto error; 2599 } 2600 err = strncpy_from_user(p, (const char __user *) usymbol, KSYM_NAME_LEN); 2601 if (err == KSYM_NAME_LEN) 2602 err = -E2BIG; 2603 if (err < 0) 2604 goto error; 2605 syms[i] = p; 2606 p += err + 1; 2607 } 2608 2609 us->syms = syms; 2610 us->buf = buf; 2611 return 0; 2612 2613 error: 2614 if (err) { 2615 kvfree(syms); 2616 kvfree(buf); 2617 } 2618 return err; 2619 } 2620 2621 static void kprobe_multi_put_modules(struct module **mods, u32 cnt) 2622 { 2623 u32 i; 2624 2625 for (i = 0; i < cnt; i++) 2626 module_put(mods[i]); 2627 } 2628 2629 static void free_user_syms(struct user_syms *us) 2630 { 2631 kvfree(us->syms); 2632 kvfree(us->buf); 2633 } 2634 2635 static void bpf_kprobe_multi_link_release(struct bpf_link *link) 2636 { 2637 struct bpf_kprobe_multi_link *kmulti_link; 2638 2639 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); 2640 unregister_fprobe(&kmulti_link->fp); 2641 kprobe_multi_put_modules(kmulti_link->mods, kmulti_link->mods_cnt); 2642 } 2643 2644 static void bpf_kprobe_multi_link_dealloc(struct bpf_link *link) 2645 { 2646 struct bpf_kprobe_multi_link *kmulti_link; 2647 2648 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); 2649 kvfree(kmulti_link->addrs); 2650 kvfree(kmulti_link->cookies); 2651 kfree(kmulti_link->mods); 2652 kfree(kmulti_link); 2653 } 2654 2655 static int bpf_kprobe_multi_link_fill_link_info(const struct bpf_link *link, 2656 struct bpf_link_info *info) 2657 { 2658 u64 __user *ucookies = u64_to_user_ptr(info->kprobe_multi.cookies); 2659 u64 __user *uaddrs = u64_to_user_ptr(info->kprobe_multi.addrs); 2660 struct bpf_kprobe_multi_link *kmulti_link; 2661 u32 ucount = info->kprobe_multi.count; 2662 int err = 0, i; 2663 2664 if (!uaddrs ^ !ucount) 2665 return -EINVAL; 2666 if (ucookies && !ucount) 2667 return -EINVAL; 2668 2669 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); 2670 info->kprobe_multi.count = kmulti_link->cnt; 2671 info->kprobe_multi.flags = kmulti_link->flags; 2672 info->kprobe_multi.missed = kmulti_link->fp.nmissed; 2673 2674 if (!uaddrs) 2675 return 0; 2676 if (ucount < kmulti_link->cnt) 2677 err = -ENOSPC; 2678 else 2679 ucount = kmulti_link->cnt; 2680 2681 if (ucookies) { 2682 if (kmulti_link->cookies) { 2683 if (copy_to_user(ucookies, kmulti_link->cookies, ucount * sizeof(u64))) 2684 return -EFAULT; 2685 } else { 2686 for (i = 0; i < ucount; i++) { 2687 if (put_user(0, ucookies + i)) 2688 return -EFAULT; 2689 } 2690 } 2691 } 2692 2693 if (kallsyms_show_value(current_cred())) { 2694 if (copy_to_user(uaddrs, kmulti_link->addrs, ucount * sizeof(u64))) 2695 return -EFAULT; 2696 } else { 2697 for (i = 0; i < ucount; i++) { 2698 if (put_user(0, uaddrs + i)) 2699 return -EFAULT; 2700 } 2701 } 2702 return err; 2703 } 2704 2705 static const struct bpf_link_ops bpf_kprobe_multi_link_lops = { 2706 .release = bpf_kprobe_multi_link_release, 2707 .dealloc_deferred = bpf_kprobe_multi_link_dealloc, 2708 .fill_link_info = bpf_kprobe_multi_link_fill_link_info, 2709 }; 2710 2711 static void bpf_kprobe_multi_cookie_swap(void *a, void *b, int size, const void *priv) 2712 { 2713 const struct bpf_kprobe_multi_link *link = priv; 2714 unsigned long *addr_a = a, *addr_b = b; 2715 u64 *cookie_a, *cookie_b; 2716 2717 cookie_a = link->cookies + (addr_a - link->addrs); 2718 cookie_b = link->cookies + (addr_b - link->addrs); 2719 2720 /* swap addr_a/addr_b and cookie_a/cookie_b values */ 2721 swap(*addr_a, *addr_b); 2722 swap(*cookie_a, *cookie_b); 2723 } 2724 2725 static int bpf_kprobe_multi_addrs_cmp(const void *a, const void *b) 2726 { 2727 const unsigned long *addr_a = a, *addr_b = b; 2728 2729 if (*addr_a == *addr_b) 2730 return 0; 2731 return *addr_a < *addr_b ? -1 : 1; 2732 } 2733 2734 static int bpf_kprobe_multi_cookie_cmp(const void *a, const void *b, const void *priv) 2735 { 2736 return bpf_kprobe_multi_addrs_cmp(a, b); 2737 } 2738 2739 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx) 2740 { 2741 struct bpf_kprobe_multi_run_ctx *run_ctx; 2742 struct bpf_kprobe_multi_link *link; 2743 u64 *cookie, entry_ip; 2744 unsigned long *addr; 2745 2746 if (WARN_ON_ONCE(!ctx)) 2747 return 0; 2748 run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, 2749 session_ctx.run_ctx); 2750 link = run_ctx->link; 2751 if (!link->cookies) 2752 return 0; 2753 entry_ip = run_ctx->entry_ip; 2754 addr = bsearch(&entry_ip, link->addrs, link->cnt, sizeof(entry_ip), 2755 bpf_kprobe_multi_addrs_cmp); 2756 if (!addr) 2757 return 0; 2758 cookie = link->cookies + (addr - link->addrs); 2759 return *cookie; 2760 } 2761 2762 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 2763 { 2764 struct bpf_kprobe_multi_run_ctx *run_ctx; 2765 2766 run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, 2767 session_ctx.run_ctx); 2768 return run_ctx->entry_ip; 2769 } 2770 2771 static int 2772 kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link, 2773 unsigned long entry_ip, struct pt_regs *regs, 2774 bool is_return, void *data) 2775 { 2776 struct bpf_kprobe_multi_run_ctx run_ctx = { 2777 .session_ctx = { 2778 .is_return = is_return, 2779 .data = data, 2780 }, 2781 .link = link, 2782 .entry_ip = entry_ip, 2783 }; 2784 struct bpf_run_ctx *old_run_ctx; 2785 int err; 2786 2787 if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) { 2788 bpf_prog_inc_misses_counter(link->link.prog); 2789 err = 0; 2790 goto out; 2791 } 2792 2793 migrate_disable(); 2794 rcu_read_lock(); 2795 old_run_ctx = bpf_set_run_ctx(&run_ctx.session_ctx.run_ctx); 2796 err = bpf_prog_run(link->link.prog, regs); 2797 bpf_reset_run_ctx(old_run_ctx); 2798 rcu_read_unlock(); 2799 migrate_enable(); 2800 2801 out: 2802 __this_cpu_dec(bpf_prog_active); 2803 return err; 2804 } 2805 2806 static int 2807 kprobe_multi_link_handler(struct fprobe *fp, unsigned long fentry_ip, 2808 unsigned long ret_ip, struct pt_regs *regs, 2809 void *data) 2810 { 2811 struct bpf_kprobe_multi_link *link; 2812 int err; 2813 2814 link = container_of(fp, struct bpf_kprobe_multi_link, fp); 2815 err = kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), regs, false, data); 2816 return is_kprobe_session(link->link.prog) ? err : 0; 2817 } 2818 2819 static void 2820 kprobe_multi_link_exit_handler(struct fprobe *fp, unsigned long fentry_ip, 2821 unsigned long ret_ip, struct pt_regs *regs, 2822 void *data) 2823 { 2824 struct bpf_kprobe_multi_link *link; 2825 2826 link = container_of(fp, struct bpf_kprobe_multi_link, fp); 2827 kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), regs, true, data); 2828 } 2829 2830 static int symbols_cmp_r(const void *a, const void *b, const void *priv) 2831 { 2832 const char **str_a = (const char **) a; 2833 const char **str_b = (const char **) b; 2834 2835 return strcmp(*str_a, *str_b); 2836 } 2837 2838 struct multi_symbols_sort { 2839 const char **funcs; 2840 u64 *cookies; 2841 }; 2842 2843 static void symbols_swap_r(void *a, void *b, int size, const void *priv) 2844 { 2845 const struct multi_symbols_sort *data = priv; 2846 const char **name_a = a, **name_b = b; 2847 2848 swap(*name_a, *name_b); 2849 2850 /* If defined, swap also related cookies. */ 2851 if (data->cookies) { 2852 u64 *cookie_a, *cookie_b; 2853 2854 cookie_a = data->cookies + (name_a - data->funcs); 2855 cookie_b = data->cookies + (name_b - data->funcs); 2856 swap(*cookie_a, *cookie_b); 2857 } 2858 } 2859 2860 struct modules_array { 2861 struct module **mods; 2862 int mods_cnt; 2863 int mods_cap; 2864 }; 2865 2866 static int add_module(struct modules_array *arr, struct module *mod) 2867 { 2868 struct module **mods; 2869 2870 if (arr->mods_cnt == arr->mods_cap) { 2871 arr->mods_cap = max(16, arr->mods_cap * 3 / 2); 2872 mods = krealloc_array(arr->mods, arr->mods_cap, sizeof(*mods), GFP_KERNEL); 2873 if (!mods) 2874 return -ENOMEM; 2875 arr->mods = mods; 2876 } 2877 2878 arr->mods[arr->mods_cnt] = mod; 2879 arr->mods_cnt++; 2880 return 0; 2881 } 2882 2883 static bool has_module(struct modules_array *arr, struct module *mod) 2884 { 2885 int i; 2886 2887 for (i = arr->mods_cnt - 1; i >= 0; i--) { 2888 if (arr->mods[i] == mod) 2889 return true; 2890 } 2891 return false; 2892 } 2893 2894 static int get_modules_for_addrs(struct module ***mods, unsigned long *addrs, u32 addrs_cnt) 2895 { 2896 struct modules_array arr = {}; 2897 u32 i, err = 0; 2898 2899 for (i = 0; i < addrs_cnt; i++) { 2900 struct module *mod; 2901 2902 preempt_disable(); 2903 mod = __module_address(addrs[i]); 2904 /* Either no module or we it's already stored */ 2905 if (!mod || has_module(&arr, mod)) { 2906 preempt_enable(); 2907 continue; 2908 } 2909 if (!try_module_get(mod)) 2910 err = -EINVAL; 2911 preempt_enable(); 2912 if (err) 2913 break; 2914 err = add_module(&arr, mod); 2915 if (err) { 2916 module_put(mod); 2917 break; 2918 } 2919 } 2920 2921 /* We return either err < 0 in case of error, ... */ 2922 if (err) { 2923 kprobe_multi_put_modules(arr.mods, arr.mods_cnt); 2924 kfree(arr.mods); 2925 return err; 2926 } 2927 2928 /* or number of modules found if everything is ok. */ 2929 *mods = arr.mods; 2930 return arr.mods_cnt; 2931 } 2932 2933 static int addrs_check_error_injection_list(unsigned long *addrs, u32 cnt) 2934 { 2935 u32 i; 2936 2937 for (i = 0; i < cnt; i++) { 2938 if (!within_error_injection_list(addrs[i])) 2939 return -EINVAL; 2940 } 2941 return 0; 2942 } 2943 2944 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 2945 { 2946 struct bpf_kprobe_multi_link *link = NULL; 2947 struct bpf_link_primer link_primer; 2948 void __user *ucookies; 2949 unsigned long *addrs; 2950 u32 flags, cnt, size; 2951 void __user *uaddrs; 2952 u64 *cookies = NULL; 2953 void __user *usyms; 2954 int err; 2955 2956 /* no support for 32bit archs yet */ 2957 if (sizeof(u64) != sizeof(void *)) 2958 return -EOPNOTSUPP; 2959 2960 if (!is_kprobe_multi(prog)) 2961 return -EINVAL; 2962 2963 flags = attr->link_create.kprobe_multi.flags; 2964 if (flags & ~BPF_F_KPROBE_MULTI_RETURN) 2965 return -EINVAL; 2966 2967 uaddrs = u64_to_user_ptr(attr->link_create.kprobe_multi.addrs); 2968 usyms = u64_to_user_ptr(attr->link_create.kprobe_multi.syms); 2969 if (!!uaddrs == !!usyms) 2970 return -EINVAL; 2971 2972 cnt = attr->link_create.kprobe_multi.cnt; 2973 if (!cnt) 2974 return -EINVAL; 2975 if (cnt > MAX_KPROBE_MULTI_CNT) 2976 return -E2BIG; 2977 2978 size = cnt * sizeof(*addrs); 2979 addrs = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL); 2980 if (!addrs) 2981 return -ENOMEM; 2982 2983 ucookies = u64_to_user_ptr(attr->link_create.kprobe_multi.cookies); 2984 if (ucookies) { 2985 cookies = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL); 2986 if (!cookies) { 2987 err = -ENOMEM; 2988 goto error; 2989 } 2990 if (copy_from_user(cookies, ucookies, size)) { 2991 err = -EFAULT; 2992 goto error; 2993 } 2994 } 2995 2996 if (uaddrs) { 2997 if (copy_from_user(addrs, uaddrs, size)) { 2998 err = -EFAULT; 2999 goto error; 3000 } 3001 } else { 3002 struct multi_symbols_sort data = { 3003 .cookies = cookies, 3004 }; 3005 struct user_syms us; 3006 3007 err = copy_user_syms(&us, usyms, cnt); 3008 if (err) 3009 goto error; 3010 3011 if (cookies) 3012 data.funcs = us.syms; 3013 3014 sort_r(us.syms, cnt, sizeof(*us.syms), symbols_cmp_r, 3015 symbols_swap_r, &data); 3016 3017 err = ftrace_lookup_symbols(us.syms, cnt, addrs); 3018 free_user_syms(&us); 3019 if (err) 3020 goto error; 3021 } 3022 3023 if (prog->kprobe_override && addrs_check_error_injection_list(addrs, cnt)) { 3024 err = -EINVAL; 3025 goto error; 3026 } 3027 3028 link = kzalloc(sizeof(*link), GFP_KERNEL); 3029 if (!link) { 3030 err = -ENOMEM; 3031 goto error; 3032 } 3033 3034 bpf_link_init(&link->link, BPF_LINK_TYPE_KPROBE_MULTI, 3035 &bpf_kprobe_multi_link_lops, prog); 3036 3037 err = bpf_link_prime(&link->link, &link_primer); 3038 if (err) 3039 goto error; 3040 3041 if (!(flags & BPF_F_KPROBE_MULTI_RETURN)) 3042 link->fp.entry_handler = kprobe_multi_link_handler; 3043 if ((flags & BPF_F_KPROBE_MULTI_RETURN) || is_kprobe_session(prog)) 3044 link->fp.exit_handler = kprobe_multi_link_exit_handler; 3045 if (is_kprobe_session(prog)) 3046 link->fp.entry_data_size = sizeof(u64); 3047 3048 link->addrs = addrs; 3049 link->cookies = cookies; 3050 link->cnt = cnt; 3051 link->flags = flags; 3052 3053 if (cookies) { 3054 /* 3055 * Sorting addresses will trigger sorting cookies as well 3056 * (check bpf_kprobe_multi_cookie_swap). This way we can 3057 * find cookie based on the address in bpf_get_attach_cookie 3058 * helper. 3059 */ 3060 sort_r(addrs, cnt, sizeof(*addrs), 3061 bpf_kprobe_multi_cookie_cmp, 3062 bpf_kprobe_multi_cookie_swap, 3063 link); 3064 } 3065 3066 err = get_modules_for_addrs(&link->mods, addrs, cnt); 3067 if (err < 0) { 3068 bpf_link_cleanup(&link_primer); 3069 return err; 3070 } 3071 link->mods_cnt = err; 3072 3073 err = register_fprobe_ips(&link->fp, addrs, cnt); 3074 if (err) { 3075 kprobe_multi_put_modules(link->mods, link->mods_cnt); 3076 bpf_link_cleanup(&link_primer); 3077 return err; 3078 } 3079 3080 return bpf_link_settle(&link_primer); 3081 3082 error: 3083 kfree(link); 3084 kvfree(addrs); 3085 kvfree(cookies); 3086 return err; 3087 } 3088 #else /* !CONFIG_FPROBE */ 3089 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 3090 { 3091 return -EOPNOTSUPP; 3092 } 3093 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx) 3094 { 3095 return 0; 3096 } 3097 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 3098 { 3099 return 0; 3100 } 3101 #endif 3102 3103 #ifdef CONFIG_UPROBES 3104 struct bpf_uprobe_multi_link; 3105 3106 struct bpf_uprobe { 3107 struct bpf_uprobe_multi_link *link; 3108 loff_t offset; 3109 unsigned long ref_ctr_offset; 3110 u64 cookie; 3111 struct uprobe *uprobe; 3112 struct uprobe_consumer consumer; 3113 bool session; 3114 }; 3115 3116 struct bpf_uprobe_multi_link { 3117 struct path path; 3118 struct bpf_link link; 3119 u32 cnt; 3120 u32 flags; 3121 struct bpf_uprobe *uprobes; 3122 struct task_struct *task; 3123 }; 3124 3125 struct bpf_uprobe_multi_run_ctx { 3126 struct bpf_session_run_ctx session_ctx; 3127 unsigned long entry_ip; 3128 struct bpf_uprobe *uprobe; 3129 }; 3130 3131 static void bpf_uprobe_unregister(struct bpf_uprobe *uprobes, u32 cnt) 3132 { 3133 u32 i; 3134 3135 for (i = 0; i < cnt; i++) 3136 uprobe_unregister_nosync(uprobes[i].uprobe, &uprobes[i].consumer); 3137 3138 if (cnt) 3139 uprobe_unregister_sync(); 3140 } 3141 3142 static void bpf_uprobe_multi_link_release(struct bpf_link *link) 3143 { 3144 struct bpf_uprobe_multi_link *umulti_link; 3145 3146 umulti_link = container_of(link, struct bpf_uprobe_multi_link, link); 3147 bpf_uprobe_unregister(umulti_link->uprobes, umulti_link->cnt); 3148 if (umulti_link->task) 3149 put_task_struct(umulti_link->task); 3150 path_put(&umulti_link->path); 3151 } 3152 3153 static void bpf_uprobe_multi_link_dealloc(struct bpf_link *link) 3154 { 3155 struct bpf_uprobe_multi_link *umulti_link; 3156 3157 umulti_link = container_of(link, struct bpf_uprobe_multi_link, link); 3158 kvfree(umulti_link->uprobes); 3159 kfree(umulti_link); 3160 } 3161 3162 static int bpf_uprobe_multi_link_fill_link_info(const struct bpf_link *link, 3163 struct bpf_link_info *info) 3164 { 3165 u64 __user *uref_ctr_offsets = u64_to_user_ptr(info->uprobe_multi.ref_ctr_offsets); 3166 u64 __user *ucookies = u64_to_user_ptr(info->uprobe_multi.cookies); 3167 u64 __user *uoffsets = u64_to_user_ptr(info->uprobe_multi.offsets); 3168 u64 __user *upath = u64_to_user_ptr(info->uprobe_multi.path); 3169 u32 upath_size = info->uprobe_multi.path_size; 3170 struct bpf_uprobe_multi_link *umulti_link; 3171 u32 ucount = info->uprobe_multi.count; 3172 int err = 0, i; 3173 char *p, *buf; 3174 long left = 0; 3175 3176 if (!upath ^ !upath_size) 3177 return -EINVAL; 3178 3179 if ((uoffsets || uref_ctr_offsets || ucookies) && !ucount) 3180 return -EINVAL; 3181 3182 umulti_link = container_of(link, struct bpf_uprobe_multi_link, link); 3183 info->uprobe_multi.count = umulti_link->cnt; 3184 info->uprobe_multi.flags = umulti_link->flags; 3185 info->uprobe_multi.pid = umulti_link->task ? 3186 task_pid_nr_ns(umulti_link->task, task_active_pid_ns(current)) : 0; 3187 3188 upath_size = upath_size ? min_t(u32, upath_size, PATH_MAX) : PATH_MAX; 3189 buf = kmalloc(upath_size, GFP_KERNEL); 3190 if (!buf) 3191 return -ENOMEM; 3192 p = d_path(&umulti_link->path, buf, upath_size); 3193 if (IS_ERR(p)) { 3194 kfree(buf); 3195 return PTR_ERR(p); 3196 } 3197 upath_size = buf + upath_size - p; 3198 3199 if (upath) 3200 left = copy_to_user(upath, p, upath_size); 3201 kfree(buf); 3202 if (left) 3203 return -EFAULT; 3204 info->uprobe_multi.path_size = upath_size; 3205 3206 if (!uoffsets && !ucookies && !uref_ctr_offsets) 3207 return 0; 3208 3209 if (ucount < umulti_link->cnt) 3210 err = -ENOSPC; 3211 else 3212 ucount = umulti_link->cnt; 3213 3214 for (i = 0; i < ucount; i++) { 3215 if (uoffsets && 3216 put_user(umulti_link->uprobes[i].offset, uoffsets + i)) 3217 return -EFAULT; 3218 if (uref_ctr_offsets && 3219 put_user(umulti_link->uprobes[i].ref_ctr_offset, uref_ctr_offsets + i)) 3220 return -EFAULT; 3221 if (ucookies && 3222 put_user(umulti_link->uprobes[i].cookie, ucookies + i)) 3223 return -EFAULT; 3224 } 3225 3226 return err; 3227 } 3228 3229 static const struct bpf_link_ops bpf_uprobe_multi_link_lops = { 3230 .release = bpf_uprobe_multi_link_release, 3231 .dealloc_deferred = bpf_uprobe_multi_link_dealloc, 3232 .fill_link_info = bpf_uprobe_multi_link_fill_link_info, 3233 }; 3234 3235 static int uprobe_prog_run(struct bpf_uprobe *uprobe, 3236 unsigned long entry_ip, 3237 struct pt_regs *regs, 3238 bool is_return, void *data) 3239 { 3240 struct bpf_uprobe_multi_link *link = uprobe->link; 3241 struct bpf_uprobe_multi_run_ctx run_ctx = { 3242 .session_ctx = { 3243 .is_return = is_return, 3244 .data = data, 3245 }, 3246 .entry_ip = entry_ip, 3247 .uprobe = uprobe, 3248 }; 3249 struct bpf_prog *prog = link->link.prog; 3250 bool sleepable = prog->sleepable; 3251 struct bpf_run_ctx *old_run_ctx; 3252 int err; 3253 3254 if (link->task && !same_thread_group(current, link->task)) 3255 return 0; 3256 3257 if (sleepable) 3258 rcu_read_lock_trace(); 3259 else 3260 rcu_read_lock(); 3261 3262 migrate_disable(); 3263 3264 old_run_ctx = bpf_set_run_ctx(&run_ctx.session_ctx.run_ctx); 3265 err = bpf_prog_run(link->link.prog, regs); 3266 bpf_reset_run_ctx(old_run_ctx); 3267 3268 migrate_enable(); 3269 3270 if (sleepable) 3271 rcu_read_unlock_trace(); 3272 else 3273 rcu_read_unlock(); 3274 return err; 3275 } 3276 3277 static bool 3278 uprobe_multi_link_filter(struct uprobe_consumer *con, struct mm_struct *mm) 3279 { 3280 struct bpf_uprobe *uprobe; 3281 3282 uprobe = container_of(con, struct bpf_uprobe, consumer); 3283 return uprobe->link->task->mm == mm; 3284 } 3285 3286 static int 3287 uprobe_multi_link_handler(struct uprobe_consumer *con, struct pt_regs *regs, 3288 __u64 *data) 3289 { 3290 struct bpf_uprobe *uprobe; 3291 int ret; 3292 3293 uprobe = container_of(con, struct bpf_uprobe, consumer); 3294 ret = uprobe_prog_run(uprobe, instruction_pointer(regs), regs, false, data); 3295 if (uprobe->session) 3296 return ret ? UPROBE_HANDLER_IGNORE : 0; 3297 return 0; 3298 } 3299 3300 static int 3301 uprobe_multi_link_ret_handler(struct uprobe_consumer *con, unsigned long func, struct pt_regs *regs, 3302 __u64 *data) 3303 { 3304 struct bpf_uprobe *uprobe; 3305 3306 uprobe = container_of(con, struct bpf_uprobe, consumer); 3307 uprobe_prog_run(uprobe, func, regs, true, data); 3308 return 0; 3309 } 3310 3311 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 3312 { 3313 struct bpf_uprobe_multi_run_ctx *run_ctx; 3314 3315 run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx, 3316 session_ctx.run_ctx); 3317 return run_ctx->entry_ip; 3318 } 3319 3320 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx) 3321 { 3322 struct bpf_uprobe_multi_run_ctx *run_ctx; 3323 3324 run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx, 3325 session_ctx.run_ctx); 3326 return run_ctx->uprobe->cookie; 3327 } 3328 3329 int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 3330 { 3331 struct bpf_uprobe_multi_link *link = NULL; 3332 unsigned long __user *uref_ctr_offsets; 3333 struct bpf_link_primer link_primer; 3334 struct bpf_uprobe *uprobes = NULL; 3335 struct task_struct *task = NULL; 3336 unsigned long __user *uoffsets; 3337 u64 __user *ucookies; 3338 void __user *upath; 3339 u32 flags, cnt, i; 3340 struct path path; 3341 char *name; 3342 pid_t pid; 3343 int err; 3344 3345 /* no support for 32bit archs yet */ 3346 if (sizeof(u64) != sizeof(void *)) 3347 return -EOPNOTSUPP; 3348 3349 if (!is_uprobe_multi(prog)) 3350 return -EINVAL; 3351 3352 flags = attr->link_create.uprobe_multi.flags; 3353 if (flags & ~BPF_F_UPROBE_MULTI_RETURN) 3354 return -EINVAL; 3355 3356 /* 3357 * path, offsets and cnt are mandatory, 3358 * ref_ctr_offsets and cookies are optional 3359 */ 3360 upath = u64_to_user_ptr(attr->link_create.uprobe_multi.path); 3361 uoffsets = u64_to_user_ptr(attr->link_create.uprobe_multi.offsets); 3362 cnt = attr->link_create.uprobe_multi.cnt; 3363 pid = attr->link_create.uprobe_multi.pid; 3364 3365 if (!upath || !uoffsets || !cnt || pid < 0) 3366 return -EINVAL; 3367 if (cnt > MAX_UPROBE_MULTI_CNT) 3368 return -E2BIG; 3369 3370 uref_ctr_offsets = u64_to_user_ptr(attr->link_create.uprobe_multi.ref_ctr_offsets); 3371 ucookies = u64_to_user_ptr(attr->link_create.uprobe_multi.cookies); 3372 3373 name = strndup_user(upath, PATH_MAX); 3374 if (IS_ERR(name)) { 3375 err = PTR_ERR(name); 3376 return err; 3377 } 3378 3379 err = kern_path(name, LOOKUP_FOLLOW, &path); 3380 kfree(name); 3381 if (err) 3382 return err; 3383 3384 if (!d_is_reg(path.dentry)) { 3385 err = -EBADF; 3386 goto error_path_put; 3387 } 3388 3389 if (pid) { 3390 task = get_pid_task(find_vpid(pid), PIDTYPE_TGID); 3391 if (!task) { 3392 err = -ESRCH; 3393 goto error_path_put; 3394 } 3395 } 3396 3397 err = -ENOMEM; 3398 3399 link = kzalloc(sizeof(*link), GFP_KERNEL); 3400 uprobes = kvcalloc(cnt, sizeof(*uprobes), GFP_KERNEL); 3401 3402 if (!uprobes || !link) 3403 goto error_free; 3404 3405 for (i = 0; i < cnt; i++) { 3406 if (__get_user(uprobes[i].offset, uoffsets + i)) { 3407 err = -EFAULT; 3408 goto error_free; 3409 } 3410 if (uprobes[i].offset < 0) { 3411 err = -EINVAL; 3412 goto error_free; 3413 } 3414 if (uref_ctr_offsets && __get_user(uprobes[i].ref_ctr_offset, uref_ctr_offsets + i)) { 3415 err = -EFAULT; 3416 goto error_free; 3417 } 3418 if (ucookies && __get_user(uprobes[i].cookie, ucookies + i)) { 3419 err = -EFAULT; 3420 goto error_free; 3421 } 3422 3423 uprobes[i].link = link; 3424 3425 if (!(flags & BPF_F_UPROBE_MULTI_RETURN)) 3426 uprobes[i].consumer.handler = uprobe_multi_link_handler; 3427 if (flags & BPF_F_UPROBE_MULTI_RETURN || is_uprobe_session(prog)) 3428 uprobes[i].consumer.ret_handler = uprobe_multi_link_ret_handler; 3429 if (is_uprobe_session(prog)) 3430 uprobes[i].session = true; 3431 if (pid) 3432 uprobes[i].consumer.filter = uprobe_multi_link_filter; 3433 } 3434 3435 link->cnt = cnt; 3436 link->uprobes = uprobes; 3437 link->path = path; 3438 link->task = task; 3439 link->flags = flags; 3440 3441 bpf_link_init(&link->link, BPF_LINK_TYPE_UPROBE_MULTI, 3442 &bpf_uprobe_multi_link_lops, prog); 3443 3444 for (i = 0; i < cnt; i++) { 3445 uprobes[i].uprobe = uprobe_register(d_real_inode(link->path.dentry), 3446 uprobes[i].offset, 3447 uprobes[i].ref_ctr_offset, 3448 &uprobes[i].consumer); 3449 if (IS_ERR(uprobes[i].uprobe)) { 3450 err = PTR_ERR(uprobes[i].uprobe); 3451 link->cnt = i; 3452 goto error_unregister; 3453 } 3454 } 3455 3456 err = bpf_link_prime(&link->link, &link_primer); 3457 if (err) 3458 goto error_unregister; 3459 3460 return bpf_link_settle(&link_primer); 3461 3462 error_unregister: 3463 bpf_uprobe_unregister(uprobes, link->cnt); 3464 3465 error_free: 3466 kvfree(uprobes); 3467 kfree(link); 3468 if (task) 3469 put_task_struct(task); 3470 error_path_put: 3471 path_put(&path); 3472 return err; 3473 } 3474 #else /* !CONFIG_UPROBES */ 3475 int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 3476 { 3477 return -EOPNOTSUPP; 3478 } 3479 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx) 3480 { 3481 return 0; 3482 } 3483 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 3484 { 3485 return 0; 3486 } 3487 #endif /* CONFIG_UPROBES */ 3488 3489 __bpf_kfunc_start_defs(); 3490 3491 __bpf_kfunc bool bpf_session_is_return(void) 3492 { 3493 struct bpf_session_run_ctx *session_ctx; 3494 3495 session_ctx = container_of(current->bpf_ctx, struct bpf_session_run_ctx, run_ctx); 3496 return session_ctx->is_return; 3497 } 3498 3499 __bpf_kfunc __u64 *bpf_session_cookie(void) 3500 { 3501 struct bpf_session_run_ctx *session_ctx; 3502 3503 session_ctx = container_of(current->bpf_ctx, struct bpf_session_run_ctx, run_ctx); 3504 return session_ctx->data; 3505 } 3506 3507 __bpf_kfunc_end_defs(); 3508 3509 BTF_KFUNCS_START(kprobe_multi_kfunc_set_ids) 3510 BTF_ID_FLAGS(func, bpf_session_is_return) 3511 BTF_ID_FLAGS(func, bpf_session_cookie) 3512 BTF_KFUNCS_END(kprobe_multi_kfunc_set_ids) 3513 3514 static int bpf_kprobe_multi_filter(const struct bpf_prog *prog, u32 kfunc_id) 3515 { 3516 if (!btf_id_set8_contains(&kprobe_multi_kfunc_set_ids, kfunc_id)) 3517 return 0; 3518 3519 if (!is_kprobe_session(prog) && !is_uprobe_session(prog)) 3520 return -EACCES; 3521 3522 return 0; 3523 } 3524 3525 static const struct btf_kfunc_id_set bpf_kprobe_multi_kfunc_set = { 3526 .owner = THIS_MODULE, 3527 .set = &kprobe_multi_kfunc_set_ids, 3528 .filter = bpf_kprobe_multi_filter, 3529 }; 3530 3531 static int __init bpf_kprobe_multi_kfuncs_init(void) 3532 { 3533 return register_btf_kfunc_id_set(BPF_PROG_TYPE_KPROBE, &bpf_kprobe_multi_kfunc_set); 3534 } 3535 3536 late_initcall(bpf_kprobe_multi_kfuncs_init); 3537 3538 __bpf_kfunc_start_defs(); 3539 3540 __bpf_kfunc int bpf_send_signal_task(struct task_struct *task, int sig, enum pid_type type, 3541 u64 value) 3542 { 3543 if (type != PIDTYPE_PID && type != PIDTYPE_TGID) 3544 return -EINVAL; 3545 3546 return bpf_send_signal_common(sig, type, task, value); 3547 } 3548 3549 __bpf_kfunc_end_defs(); 3550