1 // SPDX-License-Identifier: GPL-2.0 2 /* Copyright (c) 2011-2015 PLUMgrid, http://plumgrid.com 3 * Copyright (c) 2016 Facebook 4 */ 5 #include <linux/kernel.h> 6 #include <linux/types.h> 7 #include <linux/slab.h> 8 #include <linux/bpf.h> 9 #include <linux/bpf_verifier.h> 10 #include <linux/bpf_perf_event.h> 11 #include <linux/btf.h> 12 #include <linux/filter.h> 13 #include <linux/uaccess.h> 14 #include <linux/ctype.h> 15 #include <linux/kprobes.h> 16 #include <linux/spinlock.h> 17 #include <linux/syscalls.h> 18 #include <linux/error-injection.h> 19 #include <linux/btf_ids.h> 20 #include <linux/bpf_lsm.h> 21 #include <linux/fprobe.h> 22 #include <linux/bsearch.h> 23 #include <linux/sort.h> 24 #include <linux/key.h> 25 #include <linux/verification.h> 26 #include <linux/namei.h> 27 28 #include <net/bpf_sk_storage.h> 29 30 #include <uapi/linux/bpf.h> 31 #include <uapi/linux/btf.h> 32 33 #include <asm/tlb.h> 34 35 #include "trace_probe.h" 36 #include "trace.h" 37 38 #define CREATE_TRACE_POINTS 39 #include "bpf_trace.h" 40 41 #define bpf_event_rcu_dereference(p) \ 42 rcu_dereference_protected(p, lockdep_is_held(&bpf_event_mutex)) 43 44 #define MAX_UPROBE_MULTI_CNT (1U << 20) 45 #define MAX_KPROBE_MULTI_CNT (1U << 20) 46 47 #ifdef CONFIG_MODULES 48 struct bpf_trace_module { 49 struct module *module; 50 struct list_head list; 51 }; 52 53 static LIST_HEAD(bpf_trace_modules); 54 static DEFINE_MUTEX(bpf_module_mutex); 55 56 static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name) 57 { 58 struct bpf_raw_event_map *btp, *ret = NULL; 59 struct bpf_trace_module *btm; 60 unsigned int i; 61 62 mutex_lock(&bpf_module_mutex); 63 list_for_each_entry(btm, &bpf_trace_modules, list) { 64 for (i = 0; i < btm->module->num_bpf_raw_events; ++i) { 65 btp = &btm->module->bpf_raw_events[i]; 66 if (!strcmp(btp->tp->name, name)) { 67 if (try_module_get(btm->module)) 68 ret = btp; 69 goto out; 70 } 71 } 72 } 73 out: 74 mutex_unlock(&bpf_module_mutex); 75 return ret; 76 } 77 #else 78 static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name) 79 { 80 return NULL; 81 } 82 #endif /* CONFIG_MODULES */ 83 84 u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); 85 u64 bpf_get_stack(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); 86 87 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size, 88 u64 flags, const struct btf **btf, 89 s32 *btf_id); 90 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx); 91 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx); 92 93 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx); 94 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx); 95 96 /** 97 * trace_call_bpf - invoke BPF program 98 * @call: tracepoint event 99 * @ctx: opaque context pointer 100 * 101 * kprobe handlers execute BPF programs via this helper. 102 * Can be used from static tracepoints in the future. 103 * 104 * Return: BPF programs always return an integer which is interpreted by 105 * kprobe handler as: 106 * 0 - return from kprobe (event is filtered out) 107 * 1 - store kprobe event into ring buffer 108 * Other values are reserved and currently alias to 1 109 */ 110 unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx) 111 { 112 unsigned int ret; 113 114 cant_sleep(); 115 116 if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) { 117 /* 118 * since some bpf program is already running on this cpu, 119 * don't call into another bpf program (same or different) 120 * and don't send kprobe event into ring-buffer, 121 * so return zero here 122 */ 123 rcu_read_lock(); 124 bpf_prog_inc_misses_counters(rcu_dereference(call->prog_array)); 125 rcu_read_unlock(); 126 ret = 0; 127 goto out; 128 } 129 130 /* 131 * Instead of moving rcu_read_lock/rcu_dereference/rcu_read_unlock 132 * to all call sites, we did a bpf_prog_array_valid() there to check 133 * whether call->prog_array is empty or not, which is 134 * a heuristic to speed up execution. 135 * 136 * If bpf_prog_array_valid() fetched prog_array was 137 * non-NULL, we go into trace_call_bpf() and do the actual 138 * proper rcu_dereference() under RCU lock. 139 * If it turns out that prog_array is NULL then, we bail out. 140 * For the opposite, if the bpf_prog_array_valid() fetched pointer 141 * was NULL, you'll skip the prog_array with the risk of missing 142 * out of events when it was updated in between this and the 143 * rcu_dereference() which is accepted risk. 144 */ 145 rcu_read_lock(); 146 ret = bpf_prog_run_array(rcu_dereference(call->prog_array), 147 ctx, bpf_prog_run); 148 rcu_read_unlock(); 149 150 out: 151 __this_cpu_dec(bpf_prog_active); 152 153 return ret; 154 } 155 156 #ifdef CONFIG_BPF_KPROBE_OVERRIDE 157 BPF_CALL_2(bpf_override_return, struct pt_regs *, regs, unsigned long, rc) 158 { 159 regs_set_return_value(regs, rc); 160 override_function_with_return(regs); 161 return 0; 162 } 163 164 static const struct bpf_func_proto bpf_override_return_proto = { 165 .func = bpf_override_return, 166 .gpl_only = true, 167 .ret_type = RET_INTEGER, 168 .arg1_type = ARG_PTR_TO_CTX, 169 .arg2_type = ARG_ANYTHING, 170 }; 171 #endif 172 173 static __always_inline int 174 bpf_probe_read_user_common(void *dst, u32 size, const void __user *unsafe_ptr) 175 { 176 int ret; 177 178 ret = copy_from_user_nofault(dst, unsafe_ptr, size); 179 if (unlikely(ret < 0)) 180 memset(dst, 0, size); 181 return ret; 182 } 183 184 BPF_CALL_3(bpf_probe_read_user, void *, dst, u32, size, 185 const void __user *, unsafe_ptr) 186 { 187 return bpf_probe_read_user_common(dst, size, unsafe_ptr); 188 } 189 190 const struct bpf_func_proto bpf_probe_read_user_proto = { 191 .func = bpf_probe_read_user, 192 .gpl_only = true, 193 .ret_type = RET_INTEGER, 194 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 195 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 196 .arg3_type = ARG_ANYTHING, 197 }; 198 199 static __always_inline int 200 bpf_probe_read_user_str_common(void *dst, u32 size, 201 const void __user *unsafe_ptr) 202 { 203 int ret; 204 205 /* 206 * NB: We rely on strncpy_from_user() not copying junk past the NUL 207 * terminator into `dst`. 208 * 209 * strncpy_from_user() does long-sized strides in the fast path. If the 210 * strncpy does not mask out the bytes after the NUL in `unsafe_ptr`, 211 * then there could be junk after the NUL in `dst`. If user takes `dst` 212 * and keys a hash map with it, then semantically identical strings can 213 * occupy multiple entries in the map. 214 */ 215 ret = strncpy_from_user_nofault(dst, unsafe_ptr, size); 216 if (unlikely(ret < 0)) 217 memset(dst, 0, size); 218 return ret; 219 } 220 221 BPF_CALL_3(bpf_probe_read_user_str, void *, dst, u32, size, 222 const void __user *, unsafe_ptr) 223 { 224 return bpf_probe_read_user_str_common(dst, size, unsafe_ptr); 225 } 226 227 const struct bpf_func_proto bpf_probe_read_user_str_proto = { 228 .func = bpf_probe_read_user_str, 229 .gpl_only = true, 230 .ret_type = RET_INTEGER, 231 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 232 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 233 .arg3_type = ARG_ANYTHING, 234 }; 235 236 BPF_CALL_3(bpf_probe_read_kernel, void *, dst, u32, size, 237 const void *, unsafe_ptr) 238 { 239 return bpf_probe_read_kernel_common(dst, size, unsafe_ptr); 240 } 241 242 const struct bpf_func_proto bpf_probe_read_kernel_proto = { 243 .func = bpf_probe_read_kernel, 244 .gpl_only = true, 245 .ret_type = RET_INTEGER, 246 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 247 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 248 .arg3_type = ARG_ANYTHING, 249 }; 250 251 static __always_inline int 252 bpf_probe_read_kernel_str_common(void *dst, u32 size, const void *unsafe_ptr) 253 { 254 int ret; 255 256 /* 257 * The strncpy_from_kernel_nofault() call will likely not fill the 258 * entire buffer, but that's okay in this circumstance as we're probing 259 * arbitrary memory anyway similar to bpf_probe_read_*() and might 260 * as well probe the stack. Thus, memory is explicitly cleared 261 * only in error case, so that improper users ignoring return 262 * code altogether don't copy garbage; otherwise length of string 263 * is returned that can be used for bpf_perf_event_output() et al. 264 */ 265 ret = strncpy_from_kernel_nofault(dst, unsafe_ptr, size); 266 if (unlikely(ret < 0)) 267 memset(dst, 0, size); 268 return ret; 269 } 270 271 BPF_CALL_3(bpf_probe_read_kernel_str, void *, dst, u32, size, 272 const void *, unsafe_ptr) 273 { 274 return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr); 275 } 276 277 const struct bpf_func_proto bpf_probe_read_kernel_str_proto = { 278 .func = bpf_probe_read_kernel_str, 279 .gpl_only = true, 280 .ret_type = RET_INTEGER, 281 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 282 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 283 .arg3_type = ARG_ANYTHING, 284 }; 285 286 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 287 BPF_CALL_3(bpf_probe_read_compat, void *, dst, u32, size, 288 const void *, unsafe_ptr) 289 { 290 if ((unsigned long)unsafe_ptr < TASK_SIZE) { 291 return bpf_probe_read_user_common(dst, size, 292 (__force void __user *)unsafe_ptr); 293 } 294 return bpf_probe_read_kernel_common(dst, size, unsafe_ptr); 295 } 296 297 static const struct bpf_func_proto bpf_probe_read_compat_proto = { 298 .func = bpf_probe_read_compat, 299 .gpl_only = true, 300 .ret_type = RET_INTEGER, 301 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 302 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 303 .arg3_type = ARG_ANYTHING, 304 }; 305 306 BPF_CALL_3(bpf_probe_read_compat_str, void *, dst, u32, size, 307 const void *, unsafe_ptr) 308 { 309 if ((unsigned long)unsafe_ptr < TASK_SIZE) { 310 return bpf_probe_read_user_str_common(dst, size, 311 (__force void __user *)unsafe_ptr); 312 } 313 return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr); 314 } 315 316 static const struct bpf_func_proto bpf_probe_read_compat_str_proto = { 317 .func = bpf_probe_read_compat_str, 318 .gpl_only = true, 319 .ret_type = RET_INTEGER, 320 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 321 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 322 .arg3_type = ARG_ANYTHING, 323 }; 324 #endif /* CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE */ 325 326 BPF_CALL_3(bpf_probe_write_user, void __user *, unsafe_ptr, const void *, src, 327 u32, size) 328 { 329 /* 330 * Ensure we're in user context which is safe for the helper to 331 * run. This helper has no business in a kthread. 332 * 333 * access_ok() should prevent writing to non-user memory, but in 334 * some situations (nommu, temporary switch, etc) access_ok() does 335 * not provide enough validation, hence the check on KERNEL_DS. 336 * 337 * nmi_uaccess_okay() ensures the probe is not run in an interim 338 * state, when the task or mm are switched. This is specifically 339 * required to prevent the use of temporary mm. 340 */ 341 342 if (unlikely(in_interrupt() || 343 current->flags & (PF_KTHREAD | PF_EXITING))) 344 return -EPERM; 345 if (unlikely(!nmi_uaccess_okay())) 346 return -EPERM; 347 348 return copy_to_user_nofault(unsafe_ptr, src, size); 349 } 350 351 static const struct bpf_func_proto bpf_probe_write_user_proto = { 352 .func = bpf_probe_write_user, 353 .gpl_only = true, 354 .ret_type = RET_INTEGER, 355 .arg1_type = ARG_ANYTHING, 356 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 357 .arg3_type = ARG_CONST_SIZE, 358 }; 359 360 #define MAX_TRACE_PRINTK_VARARGS 3 361 #define BPF_TRACE_PRINTK_SIZE 1024 362 363 BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1, 364 u64, arg2, u64, arg3) 365 { 366 u64 args[MAX_TRACE_PRINTK_VARARGS] = { arg1, arg2, arg3 }; 367 struct bpf_bprintf_data data = { 368 .get_bin_args = true, 369 .get_buf = true, 370 }; 371 int ret; 372 373 ret = bpf_bprintf_prepare(fmt, fmt_size, args, 374 MAX_TRACE_PRINTK_VARARGS, &data); 375 if (ret < 0) 376 return ret; 377 378 ret = bstr_printf(data.buf, MAX_BPRINTF_BUF, fmt, data.bin_args); 379 380 trace_bpf_trace_printk(data.buf); 381 382 bpf_bprintf_cleanup(&data); 383 384 return ret; 385 } 386 387 static const struct bpf_func_proto bpf_trace_printk_proto = { 388 .func = bpf_trace_printk, 389 .gpl_only = true, 390 .ret_type = RET_INTEGER, 391 .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY, 392 .arg2_type = ARG_CONST_SIZE, 393 }; 394 395 static void __set_printk_clr_event(struct work_struct *work) 396 { 397 /* 398 * This program might be calling bpf_trace_printk, 399 * so enable the associated bpf_trace/bpf_trace_printk event. 400 * Repeat this each time as it is possible a user has 401 * disabled bpf_trace_printk events. By loading a program 402 * calling bpf_trace_printk() however the user has expressed 403 * the intent to see such events. 404 */ 405 if (trace_set_clr_event("bpf_trace", "bpf_trace_printk", 1)) 406 pr_warn_ratelimited("could not enable bpf_trace_printk events"); 407 } 408 static DECLARE_WORK(set_printk_work, __set_printk_clr_event); 409 410 const struct bpf_func_proto *bpf_get_trace_printk_proto(void) 411 { 412 schedule_work(&set_printk_work); 413 return &bpf_trace_printk_proto; 414 } 415 416 BPF_CALL_4(bpf_trace_vprintk, char *, fmt, u32, fmt_size, const void *, args, 417 u32, data_len) 418 { 419 struct bpf_bprintf_data data = { 420 .get_bin_args = true, 421 .get_buf = true, 422 }; 423 int ret, num_args; 424 425 if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 || 426 (data_len && !args)) 427 return -EINVAL; 428 num_args = data_len / 8; 429 430 ret = bpf_bprintf_prepare(fmt, fmt_size, args, num_args, &data); 431 if (ret < 0) 432 return ret; 433 434 ret = bstr_printf(data.buf, MAX_BPRINTF_BUF, fmt, data.bin_args); 435 436 trace_bpf_trace_printk(data.buf); 437 438 bpf_bprintf_cleanup(&data); 439 440 return ret; 441 } 442 443 static const struct bpf_func_proto bpf_trace_vprintk_proto = { 444 .func = bpf_trace_vprintk, 445 .gpl_only = true, 446 .ret_type = RET_INTEGER, 447 .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY, 448 .arg2_type = ARG_CONST_SIZE, 449 .arg3_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY, 450 .arg4_type = ARG_CONST_SIZE_OR_ZERO, 451 }; 452 453 const struct bpf_func_proto *bpf_get_trace_vprintk_proto(void) 454 { 455 schedule_work(&set_printk_work); 456 return &bpf_trace_vprintk_proto; 457 } 458 459 BPF_CALL_5(bpf_seq_printf, struct seq_file *, m, char *, fmt, u32, fmt_size, 460 const void *, args, u32, data_len) 461 { 462 struct bpf_bprintf_data data = { 463 .get_bin_args = true, 464 }; 465 int err, num_args; 466 467 if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 || 468 (data_len && !args)) 469 return -EINVAL; 470 num_args = data_len / 8; 471 472 err = bpf_bprintf_prepare(fmt, fmt_size, args, num_args, &data); 473 if (err < 0) 474 return err; 475 476 seq_bprintf(m, fmt, data.bin_args); 477 478 bpf_bprintf_cleanup(&data); 479 480 return seq_has_overflowed(m) ? -EOVERFLOW : 0; 481 } 482 483 BTF_ID_LIST_SINGLE(btf_seq_file_ids, struct, seq_file) 484 485 static const struct bpf_func_proto bpf_seq_printf_proto = { 486 .func = bpf_seq_printf, 487 .gpl_only = true, 488 .ret_type = RET_INTEGER, 489 .arg1_type = ARG_PTR_TO_BTF_ID, 490 .arg1_btf_id = &btf_seq_file_ids[0], 491 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 492 .arg3_type = ARG_CONST_SIZE, 493 .arg4_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY, 494 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 495 }; 496 497 BPF_CALL_3(bpf_seq_write, struct seq_file *, m, const void *, data, u32, len) 498 { 499 return seq_write(m, data, len) ? -EOVERFLOW : 0; 500 } 501 502 static const struct bpf_func_proto bpf_seq_write_proto = { 503 .func = bpf_seq_write, 504 .gpl_only = true, 505 .ret_type = RET_INTEGER, 506 .arg1_type = ARG_PTR_TO_BTF_ID, 507 .arg1_btf_id = &btf_seq_file_ids[0], 508 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 509 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 510 }; 511 512 BPF_CALL_4(bpf_seq_printf_btf, struct seq_file *, m, struct btf_ptr *, ptr, 513 u32, btf_ptr_size, u64, flags) 514 { 515 const struct btf *btf; 516 s32 btf_id; 517 int ret; 518 519 ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id); 520 if (ret) 521 return ret; 522 523 return btf_type_seq_show_flags(btf, btf_id, ptr->ptr, m, flags); 524 } 525 526 static const struct bpf_func_proto bpf_seq_printf_btf_proto = { 527 .func = bpf_seq_printf_btf, 528 .gpl_only = true, 529 .ret_type = RET_INTEGER, 530 .arg1_type = ARG_PTR_TO_BTF_ID, 531 .arg1_btf_id = &btf_seq_file_ids[0], 532 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 533 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 534 .arg4_type = ARG_ANYTHING, 535 }; 536 537 static __always_inline int 538 get_map_perf_counter(struct bpf_map *map, u64 flags, 539 u64 *value, u64 *enabled, u64 *running) 540 { 541 struct bpf_array *array = container_of(map, struct bpf_array, map); 542 unsigned int cpu = smp_processor_id(); 543 u64 index = flags & BPF_F_INDEX_MASK; 544 struct bpf_event_entry *ee; 545 546 if (unlikely(flags & ~(BPF_F_INDEX_MASK))) 547 return -EINVAL; 548 if (index == BPF_F_CURRENT_CPU) 549 index = cpu; 550 if (unlikely(index >= array->map.max_entries)) 551 return -E2BIG; 552 553 ee = READ_ONCE(array->ptrs[index]); 554 if (!ee) 555 return -ENOENT; 556 557 return perf_event_read_local(ee->event, value, enabled, running); 558 } 559 560 BPF_CALL_2(bpf_perf_event_read, struct bpf_map *, map, u64, flags) 561 { 562 u64 value = 0; 563 int err; 564 565 err = get_map_perf_counter(map, flags, &value, NULL, NULL); 566 /* 567 * this api is ugly since we miss [-22..-2] range of valid 568 * counter values, but that's uapi 569 */ 570 if (err) 571 return err; 572 return value; 573 } 574 575 static const struct bpf_func_proto bpf_perf_event_read_proto = { 576 .func = bpf_perf_event_read, 577 .gpl_only = true, 578 .ret_type = RET_INTEGER, 579 .arg1_type = ARG_CONST_MAP_PTR, 580 .arg2_type = ARG_ANYTHING, 581 }; 582 583 BPF_CALL_4(bpf_perf_event_read_value, struct bpf_map *, map, u64, flags, 584 struct bpf_perf_event_value *, buf, u32, size) 585 { 586 int err = -EINVAL; 587 588 if (unlikely(size != sizeof(struct bpf_perf_event_value))) 589 goto clear; 590 err = get_map_perf_counter(map, flags, &buf->counter, &buf->enabled, 591 &buf->running); 592 if (unlikely(err)) 593 goto clear; 594 return 0; 595 clear: 596 memset(buf, 0, size); 597 return err; 598 } 599 600 static const struct bpf_func_proto bpf_perf_event_read_value_proto = { 601 .func = bpf_perf_event_read_value, 602 .gpl_only = true, 603 .ret_type = RET_INTEGER, 604 .arg1_type = ARG_CONST_MAP_PTR, 605 .arg2_type = ARG_ANYTHING, 606 .arg3_type = ARG_PTR_TO_UNINIT_MEM, 607 .arg4_type = ARG_CONST_SIZE, 608 }; 609 610 const struct bpf_func_proto *bpf_get_perf_event_read_value_proto(void) 611 { 612 return &bpf_perf_event_read_value_proto; 613 } 614 615 static __always_inline u64 616 __bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map, 617 u64 flags, struct perf_raw_record *raw, 618 struct perf_sample_data *sd) 619 { 620 struct bpf_array *array = container_of(map, struct bpf_array, map); 621 unsigned int cpu = smp_processor_id(); 622 u64 index = flags & BPF_F_INDEX_MASK; 623 struct bpf_event_entry *ee; 624 struct perf_event *event; 625 626 if (index == BPF_F_CURRENT_CPU) 627 index = cpu; 628 if (unlikely(index >= array->map.max_entries)) 629 return -E2BIG; 630 631 ee = READ_ONCE(array->ptrs[index]); 632 if (!ee) 633 return -ENOENT; 634 635 event = ee->event; 636 if (unlikely(event->attr.type != PERF_TYPE_SOFTWARE || 637 event->attr.config != PERF_COUNT_SW_BPF_OUTPUT)) 638 return -EINVAL; 639 640 if (unlikely(event->oncpu != cpu)) 641 return -EOPNOTSUPP; 642 643 perf_sample_save_raw_data(sd, event, raw); 644 645 return perf_event_output(event, sd, regs); 646 } 647 648 /* 649 * Support executing tracepoints in normal, irq, and nmi context that each call 650 * bpf_perf_event_output 651 */ 652 struct bpf_trace_sample_data { 653 struct perf_sample_data sds[3]; 654 }; 655 656 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_trace_sds); 657 static DEFINE_PER_CPU(int, bpf_trace_nest_level); 658 BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map, 659 u64, flags, void *, data, u64, size) 660 { 661 struct bpf_trace_sample_data *sds; 662 struct perf_raw_record raw = { 663 .frag = { 664 .size = size, 665 .data = data, 666 }, 667 }; 668 struct perf_sample_data *sd; 669 int nest_level, err; 670 671 preempt_disable(); 672 sds = this_cpu_ptr(&bpf_trace_sds); 673 nest_level = this_cpu_inc_return(bpf_trace_nest_level); 674 675 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(sds->sds))) { 676 err = -EBUSY; 677 goto out; 678 } 679 680 sd = &sds->sds[nest_level - 1]; 681 682 if (unlikely(flags & ~(BPF_F_INDEX_MASK))) { 683 err = -EINVAL; 684 goto out; 685 } 686 687 perf_sample_data_init(sd, 0, 0); 688 689 err = __bpf_perf_event_output(regs, map, flags, &raw, sd); 690 out: 691 this_cpu_dec(bpf_trace_nest_level); 692 preempt_enable(); 693 return err; 694 } 695 696 static const struct bpf_func_proto bpf_perf_event_output_proto = { 697 .func = bpf_perf_event_output, 698 .gpl_only = true, 699 .ret_type = RET_INTEGER, 700 .arg1_type = ARG_PTR_TO_CTX, 701 .arg2_type = ARG_CONST_MAP_PTR, 702 .arg3_type = ARG_ANYTHING, 703 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, 704 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 705 }; 706 707 static DEFINE_PER_CPU(int, bpf_event_output_nest_level); 708 struct bpf_nested_pt_regs { 709 struct pt_regs regs[3]; 710 }; 711 static DEFINE_PER_CPU(struct bpf_nested_pt_regs, bpf_pt_regs); 712 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_misc_sds); 713 714 u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size, 715 void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy) 716 { 717 struct perf_raw_frag frag = { 718 .copy = ctx_copy, 719 .size = ctx_size, 720 .data = ctx, 721 }; 722 struct perf_raw_record raw = { 723 .frag = { 724 { 725 .next = ctx_size ? &frag : NULL, 726 }, 727 .size = meta_size, 728 .data = meta, 729 }, 730 }; 731 struct perf_sample_data *sd; 732 struct pt_regs *regs; 733 int nest_level; 734 u64 ret; 735 736 preempt_disable(); 737 nest_level = this_cpu_inc_return(bpf_event_output_nest_level); 738 739 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(bpf_misc_sds.sds))) { 740 ret = -EBUSY; 741 goto out; 742 } 743 sd = this_cpu_ptr(&bpf_misc_sds.sds[nest_level - 1]); 744 regs = this_cpu_ptr(&bpf_pt_regs.regs[nest_level - 1]); 745 746 perf_fetch_caller_regs(regs); 747 perf_sample_data_init(sd, 0, 0); 748 749 ret = __bpf_perf_event_output(regs, map, flags, &raw, sd); 750 out: 751 this_cpu_dec(bpf_event_output_nest_level); 752 preempt_enable(); 753 return ret; 754 } 755 756 BPF_CALL_0(bpf_get_current_task) 757 { 758 return (long) current; 759 } 760 761 const struct bpf_func_proto bpf_get_current_task_proto = { 762 .func = bpf_get_current_task, 763 .gpl_only = true, 764 .ret_type = RET_INTEGER, 765 }; 766 767 BPF_CALL_0(bpf_get_current_task_btf) 768 { 769 return (unsigned long) current; 770 } 771 772 const struct bpf_func_proto bpf_get_current_task_btf_proto = { 773 .func = bpf_get_current_task_btf, 774 .gpl_only = true, 775 .ret_type = RET_PTR_TO_BTF_ID_TRUSTED, 776 .ret_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK], 777 }; 778 779 BPF_CALL_1(bpf_task_pt_regs, struct task_struct *, task) 780 { 781 return (unsigned long) task_pt_regs(task); 782 } 783 784 BTF_ID_LIST(bpf_task_pt_regs_ids) 785 BTF_ID(struct, pt_regs) 786 787 const struct bpf_func_proto bpf_task_pt_regs_proto = { 788 .func = bpf_task_pt_regs, 789 .gpl_only = true, 790 .arg1_type = ARG_PTR_TO_BTF_ID, 791 .arg1_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK], 792 .ret_type = RET_PTR_TO_BTF_ID, 793 .ret_btf_id = &bpf_task_pt_regs_ids[0], 794 }; 795 796 struct send_signal_irq_work { 797 struct irq_work irq_work; 798 struct task_struct *task; 799 u32 sig; 800 enum pid_type type; 801 bool has_siginfo; 802 struct kernel_siginfo info; 803 }; 804 805 static DEFINE_PER_CPU(struct send_signal_irq_work, send_signal_work); 806 807 static void do_bpf_send_signal(struct irq_work *entry) 808 { 809 struct send_signal_irq_work *work; 810 struct kernel_siginfo *siginfo; 811 812 work = container_of(entry, struct send_signal_irq_work, irq_work); 813 siginfo = work->has_siginfo ? &work->info : SEND_SIG_PRIV; 814 815 group_send_sig_info(work->sig, siginfo, work->task, work->type); 816 put_task_struct(work->task); 817 } 818 819 static int bpf_send_signal_common(u32 sig, enum pid_type type, struct task_struct *task, u64 value) 820 { 821 struct send_signal_irq_work *work = NULL; 822 struct kernel_siginfo info; 823 struct kernel_siginfo *siginfo; 824 825 if (!task) { 826 task = current; 827 siginfo = SEND_SIG_PRIV; 828 } else { 829 clear_siginfo(&info); 830 info.si_signo = sig; 831 info.si_errno = 0; 832 info.si_code = SI_KERNEL; 833 info.si_pid = 0; 834 info.si_uid = 0; 835 info.si_value.sival_ptr = (void *)(unsigned long)value; 836 siginfo = &info; 837 } 838 839 /* Similar to bpf_probe_write_user, task needs to be 840 * in a sound condition and kernel memory access be 841 * permitted in order to send signal to the current 842 * task. 843 */ 844 if (unlikely(task->flags & (PF_KTHREAD | PF_EXITING))) 845 return -EPERM; 846 if (unlikely(!nmi_uaccess_okay())) 847 return -EPERM; 848 /* Task should not be pid=1 to avoid kernel panic. */ 849 if (unlikely(is_global_init(task))) 850 return -EPERM; 851 852 if (preempt_count() != 0 || irqs_disabled()) { 853 /* Do an early check on signal validity. Otherwise, 854 * the error is lost in deferred irq_work. 855 */ 856 if (unlikely(!valid_signal(sig))) 857 return -EINVAL; 858 859 work = this_cpu_ptr(&send_signal_work); 860 if (irq_work_is_busy(&work->irq_work)) 861 return -EBUSY; 862 863 /* Add the current task, which is the target of sending signal, 864 * to the irq_work. The current task may change when queued 865 * irq works get executed. 866 */ 867 work->task = get_task_struct(task); 868 work->has_siginfo = siginfo == &info; 869 if (work->has_siginfo) 870 copy_siginfo(&work->info, &info); 871 work->sig = sig; 872 work->type = type; 873 irq_work_queue(&work->irq_work); 874 return 0; 875 } 876 877 return group_send_sig_info(sig, siginfo, task, type); 878 } 879 880 BPF_CALL_1(bpf_send_signal, u32, sig) 881 { 882 return bpf_send_signal_common(sig, PIDTYPE_TGID, NULL, 0); 883 } 884 885 static const struct bpf_func_proto bpf_send_signal_proto = { 886 .func = bpf_send_signal, 887 .gpl_only = false, 888 .ret_type = RET_INTEGER, 889 .arg1_type = ARG_ANYTHING, 890 }; 891 892 BPF_CALL_1(bpf_send_signal_thread, u32, sig) 893 { 894 return bpf_send_signal_common(sig, PIDTYPE_PID, NULL, 0); 895 } 896 897 static const struct bpf_func_proto bpf_send_signal_thread_proto = { 898 .func = bpf_send_signal_thread, 899 .gpl_only = false, 900 .ret_type = RET_INTEGER, 901 .arg1_type = ARG_ANYTHING, 902 }; 903 904 BPF_CALL_3(bpf_d_path, struct path *, path, char *, buf, u32, sz) 905 { 906 struct path copy; 907 long len; 908 char *p; 909 910 if (!sz) 911 return 0; 912 913 /* 914 * The path pointer is verified as trusted and safe to use, 915 * but let's double check it's valid anyway to workaround 916 * potentially broken verifier. 917 */ 918 len = copy_from_kernel_nofault(©, path, sizeof(*path)); 919 if (len < 0) 920 return len; 921 922 p = d_path(©, buf, sz); 923 if (IS_ERR(p)) { 924 len = PTR_ERR(p); 925 } else { 926 len = buf + sz - p; 927 memmove(buf, p, len); 928 } 929 930 return len; 931 } 932 933 BTF_SET_START(btf_allowlist_d_path) 934 #ifdef CONFIG_SECURITY 935 BTF_ID(func, security_file_permission) 936 BTF_ID(func, security_inode_getattr) 937 BTF_ID(func, security_file_open) 938 #endif 939 #ifdef CONFIG_SECURITY_PATH 940 BTF_ID(func, security_path_truncate) 941 #endif 942 BTF_ID(func, vfs_truncate) 943 BTF_ID(func, vfs_fallocate) 944 BTF_ID(func, dentry_open) 945 BTF_ID(func, vfs_getattr) 946 BTF_ID(func, filp_close) 947 BTF_SET_END(btf_allowlist_d_path) 948 949 static bool bpf_d_path_allowed(const struct bpf_prog *prog) 950 { 951 if (prog->type == BPF_PROG_TYPE_TRACING && 952 prog->expected_attach_type == BPF_TRACE_ITER) 953 return true; 954 955 if (prog->type == BPF_PROG_TYPE_LSM) 956 return bpf_lsm_is_sleepable_hook(prog->aux->attach_btf_id); 957 958 return btf_id_set_contains(&btf_allowlist_d_path, 959 prog->aux->attach_btf_id); 960 } 961 962 BTF_ID_LIST_SINGLE(bpf_d_path_btf_ids, struct, path) 963 964 static const struct bpf_func_proto bpf_d_path_proto = { 965 .func = bpf_d_path, 966 .gpl_only = false, 967 .ret_type = RET_INTEGER, 968 .arg1_type = ARG_PTR_TO_BTF_ID, 969 .arg1_btf_id = &bpf_d_path_btf_ids[0], 970 .arg2_type = ARG_PTR_TO_MEM, 971 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 972 .allowed = bpf_d_path_allowed, 973 }; 974 975 #define BTF_F_ALL (BTF_F_COMPACT | BTF_F_NONAME | \ 976 BTF_F_PTR_RAW | BTF_F_ZERO) 977 978 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size, 979 u64 flags, const struct btf **btf, 980 s32 *btf_id) 981 { 982 const struct btf_type *t; 983 984 if (unlikely(flags & ~(BTF_F_ALL))) 985 return -EINVAL; 986 987 if (btf_ptr_size != sizeof(struct btf_ptr)) 988 return -EINVAL; 989 990 *btf = bpf_get_btf_vmlinux(); 991 992 if (IS_ERR_OR_NULL(*btf)) 993 return IS_ERR(*btf) ? PTR_ERR(*btf) : -EINVAL; 994 995 if (ptr->type_id > 0) 996 *btf_id = ptr->type_id; 997 else 998 return -EINVAL; 999 1000 if (*btf_id > 0) 1001 t = btf_type_by_id(*btf, *btf_id); 1002 if (*btf_id <= 0 || !t) 1003 return -ENOENT; 1004 1005 return 0; 1006 } 1007 1008 BPF_CALL_5(bpf_snprintf_btf, char *, str, u32, str_size, struct btf_ptr *, ptr, 1009 u32, btf_ptr_size, u64, flags) 1010 { 1011 const struct btf *btf; 1012 s32 btf_id; 1013 int ret; 1014 1015 ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id); 1016 if (ret) 1017 return ret; 1018 1019 return btf_type_snprintf_show(btf, btf_id, ptr->ptr, str, str_size, 1020 flags); 1021 } 1022 1023 const struct bpf_func_proto bpf_snprintf_btf_proto = { 1024 .func = bpf_snprintf_btf, 1025 .gpl_only = false, 1026 .ret_type = RET_INTEGER, 1027 .arg1_type = ARG_PTR_TO_MEM, 1028 .arg2_type = ARG_CONST_SIZE, 1029 .arg3_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1030 .arg4_type = ARG_CONST_SIZE, 1031 .arg5_type = ARG_ANYTHING, 1032 }; 1033 1034 BPF_CALL_1(bpf_get_func_ip_tracing, void *, ctx) 1035 { 1036 /* This helper call is inlined by verifier. */ 1037 return ((u64 *)ctx)[-2]; 1038 } 1039 1040 static const struct bpf_func_proto bpf_get_func_ip_proto_tracing = { 1041 .func = bpf_get_func_ip_tracing, 1042 .gpl_only = true, 1043 .ret_type = RET_INTEGER, 1044 .arg1_type = ARG_PTR_TO_CTX, 1045 }; 1046 1047 static inline unsigned long get_entry_ip(unsigned long fentry_ip) 1048 { 1049 #ifdef CONFIG_X86_KERNEL_IBT 1050 if (is_endbr((void *)(fentry_ip - ENDBR_INSN_SIZE))) 1051 fentry_ip -= ENDBR_INSN_SIZE; 1052 #endif 1053 return fentry_ip; 1054 } 1055 1056 BPF_CALL_1(bpf_get_func_ip_kprobe, struct pt_regs *, regs) 1057 { 1058 struct bpf_trace_run_ctx *run_ctx __maybe_unused; 1059 struct kprobe *kp; 1060 1061 #ifdef CONFIG_UPROBES 1062 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); 1063 if (run_ctx->is_uprobe) 1064 return ((struct uprobe_dispatch_data *)current->utask->vaddr)->bp_addr; 1065 #endif 1066 1067 kp = kprobe_running(); 1068 1069 if (!kp || !(kp->flags & KPROBE_FLAG_ON_FUNC_ENTRY)) 1070 return 0; 1071 1072 return get_entry_ip((uintptr_t)kp->addr); 1073 } 1074 1075 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe = { 1076 .func = bpf_get_func_ip_kprobe, 1077 .gpl_only = true, 1078 .ret_type = RET_INTEGER, 1079 .arg1_type = ARG_PTR_TO_CTX, 1080 }; 1081 1082 BPF_CALL_1(bpf_get_func_ip_kprobe_multi, struct pt_regs *, regs) 1083 { 1084 return bpf_kprobe_multi_entry_ip(current->bpf_ctx); 1085 } 1086 1087 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe_multi = { 1088 .func = bpf_get_func_ip_kprobe_multi, 1089 .gpl_only = false, 1090 .ret_type = RET_INTEGER, 1091 .arg1_type = ARG_PTR_TO_CTX, 1092 }; 1093 1094 BPF_CALL_1(bpf_get_attach_cookie_kprobe_multi, struct pt_regs *, regs) 1095 { 1096 return bpf_kprobe_multi_cookie(current->bpf_ctx); 1097 } 1098 1099 static const struct bpf_func_proto bpf_get_attach_cookie_proto_kmulti = { 1100 .func = bpf_get_attach_cookie_kprobe_multi, 1101 .gpl_only = false, 1102 .ret_type = RET_INTEGER, 1103 .arg1_type = ARG_PTR_TO_CTX, 1104 }; 1105 1106 BPF_CALL_1(bpf_get_func_ip_uprobe_multi, struct pt_regs *, regs) 1107 { 1108 return bpf_uprobe_multi_entry_ip(current->bpf_ctx); 1109 } 1110 1111 static const struct bpf_func_proto bpf_get_func_ip_proto_uprobe_multi = { 1112 .func = bpf_get_func_ip_uprobe_multi, 1113 .gpl_only = false, 1114 .ret_type = RET_INTEGER, 1115 .arg1_type = ARG_PTR_TO_CTX, 1116 }; 1117 1118 BPF_CALL_1(bpf_get_attach_cookie_uprobe_multi, struct pt_regs *, regs) 1119 { 1120 return bpf_uprobe_multi_cookie(current->bpf_ctx); 1121 } 1122 1123 static const struct bpf_func_proto bpf_get_attach_cookie_proto_umulti = { 1124 .func = bpf_get_attach_cookie_uprobe_multi, 1125 .gpl_only = false, 1126 .ret_type = RET_INTEGER, 1127 .arg1_type = ARG_PTR_TO_CTX, 1128 }; 1129 1130 BPF_CALL_1(bpf_get_attach_cookie_trace, void *, ctx) 1131 { 1132 struct bpf_trace_run_ctx *run_ctx; 1133 1134 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); 1135 return run_ctx->bpf_cookie; 1136 } 1137 1138 static const struct bpf_func_proto bpf_get_attach_cookie_proto_trace = { 1139 .func = bpf_get_attach_cookie_trace, 1140 .gpl_only = false, 1141 .ret_type = RET_INTEGER, 1142 .arg1_type = ARG_PTR_TO_CTX, 1143 }; 1144 1145 BPF_CALL_1(bpf_get_attach_cookie_pe, struct bpf_perf_event_data_kern *, ctx) 1146 { 1147 return ctx->event->bpf_cookie; 1148 } 1149 1150 static const struct bpf_func_proto bpf_get_attach_cookie_proto_pe = { 1151 .func = bpf_get_attach_cookie_pe, 1152 .gpl_only = false, 1153 .ret_type = RET_INTEGER, 1154 .arg1_type = ARG_PTR_TO_CTX, 1155 }; 1156 1157 BPF_CALL_1(bpf_get_attach_cookie_tracing, void *, ctx) 1158 { 1159 struct bpf_trace_run_ctx *run_ctx; 1160 1161 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); 1162 return run_ctx->bpf_cookie; 1163 } 1164 1165 static const struct bpf_func_proto bpf_get_attach_cookie_proto_tracing = { 1166 .func = bpf_get_attach_cookie_tracing, 1167 .gpl_only = false, 1168 .ret_type = RET_INTEGER, 1169 .arg1_type = ARG_PTR_TO_CTX, 1170 }; 1171 1172 BPF_CALL_3(bpf_get_branch_snapshot, void *, buf, u32, size, u64, flags) 1173 { 1174 static const u32 br_entry_size = sizeof(struct perf_branch_entry); 1175 u32 entry_cnt = size / br_entry_size; 1176 1177 entry_cnt = static_call(perf_snapshot_branch_stack)(buf, entry_cnt); 1178 1179 if (unlikely(flags)) 1180 return -EINVAL; 1181 1182 if (!entry_cnt) 1183 return -ENOENT; 1184 1185 return entry_cnt * br_entry_size; 1186 } 1187 1188 static const struct bpf_func_proto bpf_get_branch_snapshot_proto = { 1189 .func = bpf_get_branch_snapshot, 1190 .gpl_only = true, 1191 .ret_type = RET_INTEGER, 1192 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 1193 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 1194 }; 1195 1196 BPF_CALL_3(get_func_arg, void *, ctx, u32, n, u64 *, value) 1197 { 1198 /* This helper call is inlined by verifier. */ 1199 u64 nr_args = ((u64 *)ctx)[-1]; 1200 1201 if ((u64) n >= nr_args) 1202 return -EINVAL; 1203 *value = ((u64 *)ctx)[n]; 1204 return 0; 1205 } 1206 1207 static const struct bpf_func_proto bpf_get_func_arg_proto = { 1208 .func = get_func_arg, 1209 .ret_type = RET_INTEGER, 1210 .arg1_type = ARG_PTR_TO_CTX, 1211 .arg2_type = ARG_ANYTHING, 1212 .arg3_type = ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED, 1213 .arg3_size = sizeof(u64), 1214 }; 1215 1216 BPF_CALL_2(get_func_ret, void *, ctx, u64 *, value) 1217 { 1218 /* This helper call is inlined by verifier. */ 1219 u64 nr_args = ((u64 *)ctx)[-1]; 1220 1221 *value = ((u64 *)ctx)[nr_args]; 1222 return 0; 1223 } 1224 1225 static const struct bpf_func_proto bpf_get_func_ret_proto = { 1226 .func = get_func_ret, 1227 .ret_type = RET_INTEGER, 1228 .arg1_type = ARG_PTR_TO_CTX, 1229 .arg2_type = ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED, 1230 .arg2_size = sizeof(u64), 1231 }; 1232 1233 BPF_CALL_1(get_func_arg_cnt, void *, ctx) 1234 { 1235 /* This helper call is inlined by verifier. */ 1236 return ((u64 *)ctx)[-1]; 1237 } 1238 1239 static const struct bpf_func_proto bpf_get_func_arg_cnt_proto = { 1240 .func = get_func_arg_cnt, 1241 .ret_type = RET_INTEGER, 1242 .arg1_type = ARG_PTR_TO_CTX, 1243 }; 1244 1245 #ifdef CONFIG_KEYS 1246 __bpf_kfunc_start_defs(); 1247 1248 /** 1249 * bpf_lookup_user_key - lookup a key by its serial 1250 * @serial: key handle serial number 1251 * @flags: lookup-specific flags 1252 * 1253 * Search a key with a given *serial* and the provided *flags*. 1254 * If found, increment the reference count of the key by one, and 1255 * return it in the bpf_key structure. 1256 * 1257 * The bpf_key structure must be passed to bpf_key_put() when done 1258 * with it, so that the key reference count is decremented and the 1259 * bpf_key structure is freed. 1260 * 1261 * Permission checks are deferred to the time the key is used by 1262 * one of the available key-specific kfuncs. 1263 * 1264 * Set *flags* with KEY_LOOKUP_CREATE, to attempt creating a requested 1265 * special keyring (e.g. session keyring), if it doesn't yet exist. 1266 * Set *flags* with KEY_LOOKUP_PARTIAL, to lookup a key without waiting 1267 * for the key construction, and to retrieve uninstantiated keys (keys 1268 * without data attached to them). 1269 * 1270 * Return: a bpf_key pointer with a valid key pointer if the key is found, a 1271 * NULL pointer otherwise. 1272 */ 1273 __bpf_kfunc struct bpf_key *bpf_lookup_user_key(u32 serial, u64 flags) 1274 { 1275 key_ref_t key_ref; 1276 struct bpf_key *bkey; 1277 1278 if (flags & ~KEY_LOOKUP_ALL) 1279 return NULL; 1280 1281 /* 1282 * Permission check is deferred until the key is used, as the 1283 * intent of the caller is unknown here. 1284 */ 1285 key_ref = lookup_user_key(serial, flags, KEY_DEFER_PERM_CHECK); 1286 if (IS_ERR(key_ref)) 1287 return NULL; 1288 1289 bkey = kmalloc(sizeof(*bkey), GFP_KERNEL); 1290 if (!bkey) { 1291 key_put(key_ref_to_ptr(key_ref)); 1292 return NULL; 1293 } 1294 1295 bkey->key = key_ref_to_ptr(key_ref); 1296 bkey->has_ref = true; 1297 1298 return bkey; 1299 } 1300 1301 /** 1302 * bpf_lookup_system_key - lookup a key by a system-defined ID 1303 * @id: key ID 1304 * 1305 * Obtain a bpf_key structure with a key pointer set to the passed key ID. 1306 * The key pointer is marked as invalid, to prevent bpf_key_put() from 1307 * attempting to decrement the key reference count on that pointer. The key 1308 * pointer set in such way is currently understood only by 1309 * verify_pkcs7_signature(). 1310 * 1311 * Set *id* to one of the values defined in include/linux/verification.h: 1312 * 0 for the primary keyring (immutable keyring of system keys); 1313 * VERIFY_USE_SECONDARY_KEYRING for both the primary and secondary keyring 1314 * (where keys can be added only if they are vouched for by existing keys 1315 * in those keyrings); VERIFY_USE_PLATFORM_KEYRING for the platform 1316 * keyring (primarily used by the integrity subsystem to verify a kexec'ed 1317 * kerned image and, possibly, the initramfs signature). 1318 * 1319 * Return: a bpf_key pointer with an invalid key pointer set from the 1320 * pre-determined ID on success, a NULL pointer otherwise 1321 */ 1322 __bpf_kfunc struct bpf_key *bpf_lookup_system_key(u64 id) 1323 { 1324 struct bpf_key *bkey; 1325 1326 if (system_keyring_id_check(id) < 0) 1327 return NULL; 1328 1329 bkey = kmalloc(sizeof(*bkey), GFP_ATOMIC); 1330 if (!bkey) 1331 return NULL; 1332 1333 bkey->key = (struct key *)(unsigned long)id; 1334 bkey->has_ref = false; 1335 1336 return bkey; 1337 } 1338 1339 /** 1340 * bpf_key_put - decrement key reference count if key is valid and free bpf_key 1341 * @bkey: bpf_key structure 1342 * 1343 * Decrement the reference count of the key inside *bkey*, if the pointer 1344 * is valid, and free *bkey*. 1345 */ 1346 __bpf_kfunc void bpf_key_put(struct bpf_key *bkey) 1347 { 1348 if (bkey->has_ref) 1349 key_put(bkey->key); 1350 1351 kfree(bkey); 1352 } 1353 1354 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION 1355 /** 1356 * bpf_verify_pkcs7_signature - verify a PKCS#7 signature 1357 * @data_p: data to verify 1358 * @sig_p: signature of the data 1359 * @trusted_keyring: keyring with keys trusted for signature verification 1360 * 1361 * Verify the PKCS#7 signature *sig_ptr* against the supplied *data_ptr* 1362 * with keys in a keyring referenced by *trusted_keyring*. 1363 * 1364 * Return: 0 on success, a negative value on error. 1365 */ 1366 __bpf_kfunc int bpf_verify_pkcs7_signature(struct bpf_dynptr *data_p, 1367 struct bpf_dynptr *sig_p, 1368 struct bpf_key *trusted_keyring) 1369 { 1370 struct bpf_dynptr_kern *data_ptr = (struct bpf_dynptr_kern *)data_p; 1371 struct bpf_dynptr_kern *sig_ptr = (struct bpf_dynptr_kern *)sig_p; 1372 const void *data, *sig; 1373 u32 data_len, sig_len; 1374 int ret; 1375 1376 if (trusted_keyring->has_ref) { 1377 /* 1378 * Do the permission check deferred in bpf_lookup_user_key(). 1379 * See bpf_lookup_user_key() for more details. 1380 * 1381 * A call to key_task_permission() here would be redundant, as 1382 * it is already done by keyring_search() called by 1383 * find_asymmetric_key(). 1384 */ 1385 ret = key_validate(trusted_keyring->key); 1386 if (ret < 0) 1387 return ret; 1388 } 1389 1390 data_len = __bpf_dynptr_size(data_ptr); 1391 data = __bpf_dynptr_data(data_ptr, data_len); 1392 sig_len = __bpf_dynptr_size(sig_ptr); 1393 sig = __bpf_dynptr_data(sig_ptr, sig_len); 1394 1395 return verify_pkcs7_signature(data, data_len, sig, sig_len, 1396 trusted_keyring->key, 1397 VERIFYING_UNSPECIFIED_SIGNATURE, NULL, 1398 NULL); 1399 } 1400 #endif /* CONFIG_SYSTEM_DATA_VERIFICATION */ 1401 1402 __bpf_kfunc_end_defs(); 1403 1404 BTF_KFUNCS_START(key_sig_kfunc_set) 1405 BTF_ID_FLAGS(func, bpf_lookup_user_key, KF_ACQUIRE | KF_RET_NULL | KF_SLEEPABLE) 1406 BTF_ID_FLAGS(func, bpf_lookup_system_key, KF_ACQUIRE | KF_RET_NULL) 1407 BTF_ID_FLAGS(func, bpf_key_put, KF_RELEASE) 1408 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION 1409 BTF_ID_FLAGS(func, bpf_verify_pkcs7_signature, KF_SLEEPABLE) 1410 #endif 1411 BTF_KFUNCS_END(key_sig_kfunc_set) 1412 1413 static const struct btf_kfunc_id_set bpf_key_sig_kfunc_set = { 1414 .owner = THIS_MODULE, 1415 .set = &key_sig_kfunc_set, 1416 }; 1417 1418 static int __init bpf_key_sig_kfuncs_init(void) 1419 { 1420 return register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, 1421 &bpf_key_sig_kfunc_set); 1422 } 1423 1424 late_initcall(bpf_key_sig_kfuncs_init); 1425 #endif /* CONFIG_KEYS */ 1426 1427 static const struct bpf_func_proto * 1428 bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1429 { 1430 const struct bpf_func_proto *func_proto; 1431 1432 switch (func_id) { 1433 case BPF_FUNC_get_current_uid_gid: 1434 return &bpf_get_current_uid_gid_proto; 1435 case BPF_FUNC_get_current_comm: 1436 return &bpf_get_current_comm_proto; 1437 case BPF_FUNC_get_smp_processor_id: 1438 return &bpf_get_smp_processor_id_proto; 1439 case BPF_FUNC_perf_event_read: 1440 return &bpf_perf_event_read_proto; 1441 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 1442 case BPF_FUNC_probe_read: 1443 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1444 NULL : &bpf_probe_read_compat_proto; 1445 case BPF_FUNC_probe_read_str: 1446 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1447 NULL : &bpf_probe_read_compat_str_proto; 1448 #endif 1449 #ifdef CONFIG_CGROUPS 1450 case BPF_FUNC_current_task_under_cgroup: 1451 return &bpf_current_task_under_cgroup_proto; 1452 #endif 1453 case BPF_FUNC_send_signal: 1454 return &bpf_send_signal_proto; 1455 case BPF_FUNC_send_signal_thread: 1456 return &bpf_send_signal_thread_proto; 1457 case BPF_FUNC_get_task_stack: 1458 return prog->sleepable ? &bpf_get_task_stack_sleepable_proto 1459 : &bpf_get_task_stack_proto; 1460 case BPF_FUNC_copy_from_user: 1461 return &bpf_copy_from_user_proto; 1462 case BPF_FUNC_copy_from_user_task: 1463 return &bpf_copy_from_user_task_proto; 1464 case BPF_FUNC_task_storage_get: 1465 if (bpf_prog_check_recur(prog)) 1466 return &bpf_task_storage_get_recur_proto; 1467 return &bpf_task_storage_get_proto; 1468 case BPF_FUNC_task_storage_delete: 1469 if (bpf_prog_check_recur(prog)) 1470 return &bpf_task_storage_delete_recur_proto; 1471 return &bpf_task_storage_delete_proto; 1472 case BPF_FUNC_get_func_ip: 1473 return &bpf_get_func_ip_proto_tracing; 1474 case BPF_FUNC_get_branch_snapshot: 1475 return &bpf_get_branch_snapshot_proto; 1476 case BPF_FUNC_find_vma: 1477 return &bpf_find_vma_proto; 1478 default: 1479 break; 1480 } 1481 1482 func_proto = bpf_base_func_proto(func_id, prog); 1483 if (func_proto) 1484 return func_proto; 1485 1486 if (!bpf_token_capable(prog->aux->token, CAP_SYS_ADMIN)) 1487 return NULL; 1488 1489 switch (func_id) { 1490 case BPF_FUNC_probe_write_user: 1491 return security_locked_down(LOCKDOWN_BPF_WRITE_USER) < 0 ? 1492 NULL : &bpf_probe_write_user_proto; 1493 default: 1494 return NULL; 1495 } 1496 } 1497 1498 static bool is_kprobe_multi(const struct bpf_prog *prog) 1499 { 1500 return prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI || 1501 prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION; 1502 } 1503 1504 static inline bool is_kprobe_session(const struct bpf_prog *prog) 1505 { 1506 return prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION; 1507 } 1508 1509 static inline bool is_uprobe_multi(const struct bpf_prog *prog) 1510 { 1511 return prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI || 1512 prog->expected_attach_type == BPF_TRACE_UPROBE_SESSION; 1513 } 1514 1515 static inline bool is_uprobe_session(const struct bpf_prog *prog) 1516 { 1517 return prog->expected_attach_type == BPF_TRACE_UPROBE_SESSION; 1518 } 1519 1520 static const struct bpf_func_proto * 1521 kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1522 { 1523 switch (func_id) { 1524 case BPF_FUNC_perf_event_output: 1525 return &bpf_perf_event_output_proto; 1526 case BPF_FUNC_get_stackid: 1527 return &bpf_get_stackid_proto; 1528 case BPF_FUNC_get_stack: 1529 return prog->sleepable ? &bpf_get_stack_sleepable_proto : &bpf_get_stack_proto; 1530 #ifdef CONFIG_BPF_KPROBE_OVERRIDE 1531 case BPF_FUNC_override_return: 1532 return &bpf_override_return_proto; 1533 #endif 1534 case BPF_FUNC_get_func_ip: 1535 if (is_kprobe_multi(prog)) 1536 return &bpf_get_func_ip_proto_kprobe_multi; 1537 if (is_uprobe_multi(prog)) 1538 return &bpf_get_func_ip_proto_uprobe_multi; 1539 return &bpf_get_func_ip_proto_kprobe; 1540 case BPF_FUNC_get_attach_cookie: 1541 if (is_kprobe_multi(prog)) 1542 return &bpf_get_attach_cookie_proto_kmulti; 1543 if (is_uprobe_multi(prog)) 1544 return &bpf_get_attach_cookie_proto_umulti; 1545 return &bpf_get_attach_cookie_proto_trace; 1546 default: 1547 return bpf_tracing_func_proto(func_id, prog); 1548 } 1549 } 1550 1551 /* bpf+kprobe programs can access fields of 'struct pt_regs' */ 1552 static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type, 1553 const struct bpf_prog *prog, 1554 struct bpf_insn_access_aux *info) 1555 { 1556 if (off < 0 || off >= sizeof(struct pt_regs)) 1557 return false; 1558 if (type != BPF_READ) 1559 return false; 1560 if (off % size != 0) 1561 return false; 1562 /* 1563 * Assertion for 32 bit to make sure last 8 byte access 1564 * (BPF_DW) to the last 4 byte member is disallowed. 1565 */ 1566 if (off + size > sizeof(struct pt_regs)) 1567 return false; 1568 1569 return true; 1570 } 1571 1572 const struct bpf_verifier_ops kprobe_verifier_ops = { 1573 .get_func_proto = kprobe_prog_func_proto, 1574 .is_valid_access = kprobe_prog_is_valid_access, 1575 }; 1576 1577 const struct bpf_prog_ops kprobe_prog_ops = { 1578 }; 1579 1580 BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map, 1581 u64, flags, void *, data, u64, size) 1582 { 1583 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1584 1585 /* 1586 * r1 points to perf tracepoint buffer where first 8 bytes are hidden 1587 * from bpf program and contain a pointer to 'struct pt_regs'. Fetch it 1588 * from there and call the same bpf_perf_event_output() helper inline. 1589 */ 1590 return ____bpf_perf_event_output(regs, map, flags, data, size); 1591 } 1592 1593 static const struct bpf_func_proto bpf_perf_event_output_proto_tp = { 1594 .func = bpf_perf_event_output_tp, 1595 .gpl_only = true, 1596 .ret_type = RET_INTEGER, 1597 .arg1_type = ARG_PTR_TO_CTX, 1598 .arg2_type = ARG_CONST_MAP_PTR, 1599 .arg3_type = ARG_ANYTHING, 1600 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1601 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 1602 }; 1603 1604 BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map, 1605 u64, flags) 1606 { 1607 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1608 1609 /* 1610 * Same comment as in bpf_perf_event_output_tp(), only that this time 1611 * the other helper's function body cannot be inlined due to being 1612 * external, thus we need to call raw helper function. 1613 */ 1614 return bpf_get_stackid((unsigned long) regs, (unsigned long) map, 1615 flags, 0, 0); 1616 } 1617 1618 static const struct bpf_func_proto bpf_get_stackid_proto_tp = { 1619 .func = bpf_get_stackid_tp, 1620 .gpl_only = true, 1621 .ret_type = RET_INTEGER, 1622 .arg1_type = ARG_PTR_TO_CTX, 1623 .arg2_type = ARG_CONST_MAP_PTR, 1624 .arg3_type = ARG_ANYTHING, 1625 }; 1626 1627 BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size, 1628 u64, flags) 1629 { 1630 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1631 1632 return bpf_get_stack((unsigned long) regs, (unsigned long) buf, 1633 (unsigned long) size, flags, 0); 1634 } 1635 1636 static const struct bpf_func_proto bpf_get_stack_proto_tp = { 1637 .func = bpf_get_stack_tp, 1638 .gpl_only = true, 1639 .ret_type = RET_INTEGER, 1640 .arg1_type = ARG_PTR_TO_CTX, 1641 .arg2_type = ARG_PTR_TO_UNINIT_MEM, 1642 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1643 .arg4_type = ARG_ANYTHING, 1644 }; 1645 1646 static const struct bpf_func_proto * 1647 tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1648 { 1649 switch (func_id) { 1650 case BPF_FUNC_perf_event_output: 1651 return &bpf_perf_event_output_proto_tp; 1652 case BPF_FUNC_get_stackid: 1653 return &bpf_get_stackid_proto_tp; 1654 case BPF_FUNC_get_stack: 1655 return &bpf_get_stack_proto_tp; 1656 case BPF_FUNC_get_attach_cookie: 1657 return &bpf_get_attach_cookie_proto_trace; 1658 default: 1659 return bpf_tracing_func_proto(func_id, prog); 1660 } 1661 } 1662 1663 static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type, 1664 const struct bpf_prog *prog, 1665 struct bpf_insn_access_aux *info) 1666 { 1667 if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE) 1668 return false; 1669 if (type != BPF_READ) 1670 return false; 1671 if (off % size != 0) 1672 return false; 1673 1674 BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(__u64)); 1675 return true; 1676 } 1677 1678 const struct bpf_verifier_ops tracepoint_verifier_ops = { 1679 .get_func_proto = tp_prog_func_proto, 1680 .is_valid_access = tp_prog_is_valid_access, 1681 }; 1682 1683 const struct bpf_prog_ops tracepoint_prog_ops = { 1684 }; 1685 1686 BPF_CALL_3(bpf_perf_prog_read_value, struct bpf_perf_event_data_kern *, ctx, 1687 struct bpf_perf_event_value *, buf, u32, size) 1688 { 1689 int err = -EINVAL; 1690 1691 if (unlikely(size != sizeof(struct bpf_perf_event_value))) 1692 goto clear; 1693 err = perf_event_read_local(ctx->event, &buf->counter, &buf->enabled, 1694 &buf->running); 1695 if (unlikely(err)) 1696 goto clear; 1697 return 0; 1698 clear: 1699 memset(buf, 0, size); 1700 return err; 1701 } 1702 1703 static const struct bpf_func_proto bpf_perf_prog_read_value_proto = { 1704 .func = bpf_perf_prog_read_value, 1705 .gpl_only = true, 1706 .ret_type = RET_INTEGER, 1707 .arg1_type = ARG_PTR_TO_CTX, 1708 .arg2_type = ARG_PTR_TO_UNINIT_MEM, 1709 .arg3_type = ARG_CONST_SIZE, 1710 }; 1711 1712 BPF_CALL_4(bpf_read_branch_records, struct bpf_perf_event_data_kern *, ctx, 1713 void *, buf, u32, size, u64, flags) 1714 { 1715 static const u32 br_entry_size = sizeof(struct perf_branch_entry); 1716 struct perf_branch_stack *br_stack = ctx->data->br_stack; 1717 u32 to_copy; 1718 1719 if (unlikely(flags & ~BPF_F_GET_BRANCH_RECORDS_SIZE)) 1720 return -EINVAL; 1721 1722 if (unlikely(!(ctx->data->sample_flags & PERF_SAMPLE_BRANCH_STACK))) 1723 return -ENOENT; 1724 1725 if (unlikely(!br_stack)) 1726 return -ENOENT; 1727 1728 if (flags & BPF_F_GET_BRANCH_RECORDS_SIZE) 1729 return br_stack->nr * br_entry_size; 1730 1731 if (!buf || (size % br_entry_size != 0)) 1732 return -EINVAL; 1733 1734 to_copy = min_t(u32, br_stack->nr * br_entry_size, size); 1735 memcpy(buf, br_stack->entries, to_copy); 1736 1737 return to_copy; 1738 } 1739 1740 static const struct bpf_func_proto bpf_read_branch_records_proto = { 1741 .func = bpf_read_branch_records, 1742 .gpl_only = true, 1743 .ret_type = RET_INTEGER, 1744 .arg1_type = ARG_PTR_TO_CTX, 1745 .arg2_type = ARG_PTR_TO_MEM_OR_NULL, 1746 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1747 .arg4_type = ARG_ANYTHING, 1748 }; 1749 1750 static const struct bpf_func_proto * 1751 pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1752 { 1753 switch (func_id) { 1754 case BPF_FUNC_perf_event_output: 1755 return &bpf_perf_event_output_proto_tp; 1756 case BPF_FUNC_get_stackid: 1757 return &bpf_get_stackid_proto_pe; 1758 case BPF_FUNC_get_stack: 1759 return &bpf_get_stack_proto_pe; 1760 case BPF_FUNC_perf_prog_read_value: 1761 return &bpf_perf_prog_read_value_proto; 1762 case BPF_FUNC_read_branch_records: 1763 return &bpf_read_branch_records_proto; 1764 case BPF_FUNC_get_attach_cookie: 1765 return &bpf_get_attach_cookie_proto_pe; 1766 default: 1767 return bpf_tracing_func_proto(func_id, prog); 1768 } 1769 } 1770 1771 /* 1772 * bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp 1773 * to avoid potential recursive reuse issue when/if tracepoints are added 1774 * inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack. 1775 * 1776 * Since raw tracepoints run despite bpf_prog_active, support concurrent usage 1777 * in normal, irq, and nmi context. 1778 */ 1779 struct bpf_raw_tp_regs { 1780 struct pt_regs regs[3]; 1781 }; 1782 static DEFINE_PER_CPU(struct bpf_raw_tp_regs, bpf_raw_tp_regs); 1783 static DEFINE_PER_CPU(int, bpf_raw_tp_nest_level); 1784 static struct pt_regs *get_bpf_raw_tp_regs(void) 1785 { 1786 struct bpf_raw_tp_regs *tp_regs = this_cpu_ptr(&bpf_raw_tp_regs); 1787 int nest_level = this_cpu_inc_return(bpf_raw_tp_nest_level); 1788 1789 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(tp_regs->regs))) { 1790 this_cpu_dec(bpf_raw_tp_nest_level); 1791 return ERR_PTR(-EBUSY); 1792 } 1793 1794 return &tp_regs->regs[nest_level - 1]; 1795 } 1796 1797 static void put_bpf_raw_tp_regs(void) 1798 { 1799 this_cpu_dec(bpf_raw_tp_nest_level); 1800 } 1801 1802 BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args, 1803 struct bpf_map *, map, u64, flags, void *, data, u64, size) 1804 { 1805 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1806 int ret; 1807 1808 if (IS_ERR(regs)) 1809 return PTR_ERR(regs); 1810 1811 perf_fetch_caller_regs(regs); 1812 ret = ____bpf_perf_event_output(regs, map, flags, data, size); 1813 1814 put_bpf_raw_tp_regs(); 1815 return ret; 1816 } 1817 1818 static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = { 1819 .func = bpf_perf_event_output_raw_tp, 1820 .gpl_only = true, 1821 .ret_type = RET_INTEGER, 1822 .arg1_type = ARG_PTR_TO_CTX, 1823 .arg2_type = ARG_CONST_MAP_PTR, 1824 .arg3_type = ARG_ANYTHING, 1825 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1826 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 1827 }; 1828 1829 extern const struct bpf_func_proto bpf_skb_output_proto; 1830 extern const struct bpf_func_proto bpf_xdp_output_proto; 1831 extern const struct bpf_func_proto bpf_xdp_get_buff_len_trace_proto; 1832 1833 BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args, 1834 struct bpf_map *, map, u64, flags) 1835 { 1836 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1837 int ret; 1838 1839 if (IS_ERR(regs)) 1840 return PTR_ERR(regs); 1841 1842 perf_fetch_caller_regs(regs); 1843 /* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */ 1844 ret = bpf_get_stackid((unsigned long) regs, (unsigned long) map, 1845 flags, 0, 0); 1846 put_bpf_raw_tp_regs(); 1847 return ret; 1848 } 1849 1850 static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = { 1851 .func = bpf_get_stackid_raw_tp, 1852 .gpl_only = true, 1853 .ret_type = RET_INTEGER, 1854 .arg1_type = ARG_PTR_TO_CTX, 1855 .arg2_type = ARG_CONST_MAP_PTR, 1856 .arg3_type = ARG_ANYTHING, 1857 }; 1858 1859 BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args, 1860 void *, buf, u32, size, u64, flags) 1861 { 1862 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1863 int ret; 1864 1865 if (IS_ERR(regs)) 1866 return PTR_ERR(regs); 1867 1868 perf_fetch_caller_regs(regs); 1869 ret = bpf_get_stack((unsigned long) regs, (unsigned long) buf, 1870 (unsigned long) size, flags, 0); 1871 put_bpf_raw_tp_regs(); 1872 return ret; 1873 } 1874 1875 static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = { 1876 .func = bpf_get_stack_raw_tp, 1877 .gpl_only = true, 1878 .ret_type = RET_INTEGER, 1879 .arg1_type = ARG_PTR_TO_CTX, 1880 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1881 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1882 .arg4_type = ARG_ANYTHING, 1883 }; 1884 1885 static const struct bpf_func_proto * 1886 raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1887 { 1888 switch (func_id) { 1889 case BPF_FUNC_perf_event_output: 1890 return &bpf_perf_event_output_proto_raw_tp; 1891 case BPF_FUNC_get_stackid: 1892 return &bpf_get_stackid_proto_raw_tp; 1893 case BPF_FUNC_get_stack: 1894 return &bpf_get_stack_proto_raw_tp; 1895 case BPF_FUNC_get_attach_cookie: 1896 return &bpf_get_attach_cookie_proto_tracing; 1897 default: 1898 return bpf_tracing_func_proto(func_id, prog); 1899 } 1900 } 1901 1902 const struct bpf_func_proto * 1903 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1904 { 1905 const struct bpf_func_proto *fn; 1906 1907 switch (func_id) { 1908 #ifdef CONFIG_NET 1909 case BPF_FUNC_skb_output: 1910 return &bpf_skb_output_proto; 1911 case BPF_FUNC_xdp_output: 1912 return &bpf_xdp_output_proto; 1913 case BPF_FUNC_skc_to_tcp6_sock: 1914 return &bpf_skc_to_tcp6_sock_proto; 1915 case BPF_FUNC_skc_to_tcp_sock: 1916 return &bpf_skc_to_tcp_sock_proto; 1917 case BPF_FUNC_skc_to_tcp_timewait_sock: 1918 return &bpf_skc_to_tcp_timewait_sock_proto; 1919 case BPF_FUNC_skc_to_tcp_request_sock: 1920 return &bpf_skc_to_tcp_request_sock_proto; 1921 case BPF_FUNC_skc_to_udp6_sock: 1922 return &bpf_skc_to_udp6_sock_proto; 1923 case BPF_FUNC_skc_to_unix_sock: 1924 return &bpf_skc_to_unix_sock_proto; 1925 case BPF_FUNC_skc_to_mptcp_sock: 1926 return &bpf_skc_to_mptcp_sock_proto; 1927 case BPF_FUNC_sk_storage_get: 1928 return &bpf_sk_storage_get_tracing_proto; 1929 case BPF_FUNC_sk_storage_delete: 1930 return &bpf_sk_storage_delete_tracing_proto; 1931 case BPF_FUNC_sock_from_file: 1932 return &bpf_sock_from_file_proto; 1933 case BPF_FUNC_get_socket_cookie: 1934 return &bpf_get_socket_ptr_cookie_proto; 1935 case BPF_FUNC_xdp_get_buff_len: 1936 return &bpf_xdp_get_buff_len_trace_proto; 1937 #endif 1938 case BPF_FUNC_seq_printf: 1939 return prog->expected_attach_type == BPF_TRACE_ITER ? 1940 &bpf_seq_printf_proto : 1941 NULL; 1942 case BPF_FUNC_seq_write: 1943 return prog->expected_attach_type == BPF_TRACE_ITER ? 1944 &bpf_seq_write_proto : 1945 NULL; 1946 case BPF_FUNC_seq_printf_btf: 1947 return prog->expected_attach_type == BPF_TRACE_ITER ? 1948 &bpf_seq_printf_btf_proto : 1949 NULL; 1950 case BPF_FUNC_d_path: 1951 return &bpf_d_path_proto; 1952 case BPF_FUNC_get_func_arg: 1953 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_proto : NULL; 1954 case BPF_FUNC_get_func_ret: 1955 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_ret_proto : NULL; 1956 case BPF_FUNC_get_func_arg_cnt: 1957 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_cnt_proto : NULL; 1958 case BPF_FUNC_get_attach_cookie: 1959 if (prog->type == BPF_PROG_TYPE_TRACING && 1960 prog->expected_attach_type == BPF_TRACE_RAW_TP) 1961 return &bpf_get_attach_cookie_proto_tracing; 1962 return bpf_prog_has_trampoline(prog) ? &bpf_get_attach_cookie_proto_tracing : NULL; 1963 default: 1964 fn = raw_tp_prog_func_proto(func_id, prog); 1965 if (!fn && prog->expected_attach_type == BPF_TRACE_ITER) 1966 fn = bpf_iter_get_func_proto(func_id, prog); 1967 return fn; 1968 } 1969 } 1970 1971 static bool raw_tp_prog_is_valid_access(int off, int size, 1972 enum bpf_access_type type, 1973 const struct bpf_prog *prog, 1974 struct bpf_insn_access_aux *info) 1975 { 1976 return bpf_tracing_ctx_access(off, size, type); 1977 } 1978 1979 static bool tracing_prog_is_valid_access(int off, int size, 1980 enum bpf_access_type type, 1981 const struct bpf_prog *prog, 1982 struct bpf_insn_access_aux *info) 1983 { 1984 return bpf_tracing_btf_ctx_access(off, size, type, prog, info); 1985 } 1986 1987 int __weak bpf_prog_test_run_tracing(struct bpf_prog *prog, 1988 const union bpf_attr *kattr, 1989 union bpf_attr __user *uattr) 1990 { 1991 return -ENOTSUPP; 1992 } 1993 1994 const struct bpf_verifier_ops raw_tracepoint_verifier_ops = { 1995 .get_func_proto = raw_tp_prog_func_proto, 1996 .is_valid_access = raw_tp_prog_is_valid_access, 1997 }; 1998 1999 const struct bpf_prog_ops raw_tracepoint_prog_ops = { 2000 #ifdef CONFIG_NET 2001 .test_run = bpf_prog_test_run_raw_tp, 2002 #endif 2003 }; 2004 2005 const struct bpf_verifier_ops tracing_verifier_ops = { 2006 .get_func_proto = tracing_prog_func_proto, 2007 .is_valid_access = tracing_prog_is_valid_access, 2008 }; 2009 2010 const struct bpf_prog_ops tracing_prog_ops = { 2011 .test_run = bpf_prog_test_run_tracing, 2012 }; 2013 2014 static bool raw_tp_writable_prog_is_valid_access(int off, int size, 2015 enum bpf_access_type type, 2016 const struct bpf_prog *prog, 2017 struct bpf_insn_access_aux *info) 2018 { 2019 if (off == 0) { 2020 if (size != sizeof(u64) || type != BPF_READ) 2021 return false; 2022 info->reg_type = PTR_TO_TP_BUFFER; 2023 } 2024 return raw_tp_prog_is_valid_access(off, size, type, prog, info); 2025 } 2026 2027 const struct bpf_verifier_ops raw_tracepoint_writable_verifier_ops = { 2028 .get_func_proto = raw_tp_prog_func_proto, 2029 .is_valid_access = raw_tp_writable_prog_is_valid_access, 2030 }; 2031 2032 const struct bpf_prog_ops raw_tracepoint_writable_prog_ops = { 2033 }; 2034 2035 static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type, 2036 const struct bpf_prog *prog, 2037 struct bpf_insn_access_aux *info) 2038 { 2039 const int size_u64 = sizeof(u64); 2040 2041 if (off < 0 || off >= sizeof(struct bpf_perf_event_data)) 2042 return false; 2043 if (type != BPF_READ) 2044 return false; 2045 if (off % size != 0) { 2046 if (sizeof(unsigned long) != 4) 2047 return false; 2048 if (size != 8) 2049 return false; 2050 if (off % size != 4) 2051 return false; 2052 } 2053 2054 switch (off) { 2055 case bpf_ctx_range(struct bpf_perf_event_data, sample_period): 2056 bpf_ctx_record_field_size(info, size_u64); 2057 if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) 2058 return false; 2059 break; 2060 case bpf_ctx_range(struct bpf_perf_event_data, addr): 2061 bpf_ctx_record_field_size(info, size_u64); 2062 if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) 2063 return false; 2064 break; 2065 default: 2066 if (size != sizeof(long)) 2067 return false; 2068 } 2069 2070 return true; 2071 } 2072 2073 static u32 pe_prog_convert_ctx_access(enum bpf_access_type type, 2074 const struct bpf_insn *si, 2075 struct bpf_insn *insn_buf, 2076 struct bpf_prog *prog, u32 *target_size) 2077 { 2078 struct bpf_insn *insn = insn_buf; 2079 2080 switch (si->off) { 2081 case offsetof(struct bpf_perf_event_data, sample_period): 2082 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 2083 data), si->dst_reg, si->src_reg, 2084 offsetof(struct bpf_perf_event_data_kern, data)); 2085 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, 2086 bpf_target_off(struct perf_sample_data, period, 8, 2087 target_size)); 2088 break; 2089 case offsetof(struct bpf_perf_event_data, addr): 2090 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 2091 data), si->dst_reg, si->src_reg, 2092 offsetof(struct bpf_perf_event_data_kern, data)); 2093 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, 2094 bpf_target_off(struct perf_sample_data, addr, 8, 2095 target_size)); 2096 break; 2097 default: 2098 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 2099 regs), si->dst_reg, si->src_reg, 2100 offsetof(struct bpf_perf_event_data_kern, regs)); 2101 *insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg, 2102 si->off); 2103 break; 2104 } 2105 2106 return insn - insn_buf; 2107 } 2108 2109 const struct bpf_verifier_ops perf_event_verifier_ops = { 2110 .get_func_proto = pe_prog_func_proto, 2111 .is_valid_access = pe_prog_is_valid_access, 2112 .convert_ctx_access = pe_prog_convert_ctx_access, 2113 }; 2114 2115 const struct bpf_prog_ops perf_event_prog_ops = { 2116 }; 2117 2118 static DEFINE_MUTEX(bpf_event_mutex); 2119 2120 #define BPF_TRACE_MAX_PROGS 64 2121 2122 int perf_event_attach_bpf_prog(struct perf_event *event, 2123 struct bpf_prog *prog, 2124 u64 bpf_cookie) 2125 { 2126 struct bpf_prog_array *old_array; 2127 struct bpf_prog_array *new_array; 2128 int ret = -EEXIST; 2129 2130 /* 2131 * Kprobe override only works if they are on the function entry, 2132 * and only if they are on the opt-in list. 2133 */ 2134 if (prog->kprobe_override && 2135 (!trace_kprobe_on_func_entry(event->tp_event) || 2136 !trace_kprobe_error_injectable(event->tp_event))) 2137 return -EINVAL; 2138 2139 mutex_lock(&bpf_event_mutex); 2140 2141 if (event->prog) 2142 goto unlock; 2143 2144 old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); 2145 if (old_array && 2146 bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) { 2147 ret = -E2BIG; 2148 goto unlock; 2149 } 2150 2151 ret = bpf_prog_array_copy(old_array, NULL, prog, bpf_cookie, &new_array); 2152 if (ret < 0) 2153 goto unlock; 2154 2155 /* set the new array to event->tp_event and set event->prog */ 2156 event->prog = prog; 2157 event->bpf_cookie = bpf_cookie; 2158 rcu_assign_pointer(event->tp_event->prog_array, new_array); 2159 bpf_prog_array_free_sleepable(old_array); 2160 2161 unlock: 2162 mutex_unlock(&bpf_event_mutex); 2163 return ret; 2164 } 2165 2166 void perf_event_detach_bpf_prog(struct perf_event *event) 2167 { 2168 struct bpf_prog_array *old_array; 2169 struct bpf_prog_array *new_array; 2170 struct bpf_prog *prog = NULL; 2171 int ret; 2172 2173 mutex_lock(&bpf_event_mutex); 2174 2175 if (!event->prog) 2176 goto unlock; 2177 2178 old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); 2179 if (!old_array) 2180 goto put; 2181 2182 ret = bpf_prog_array_copy(old_array, event->prog, NULL, 0, &new_array); 2183 if (ret < 0) { 2184 bpf_prog_array_delete_safe(old_array, event->prog); 2185 } else { 2186 rcu_assign_pointer(event->tp_event->prog_array, new_array); 2187 bpf_prog_array_free_sleepable(old_array); 2188 } 2189 2190 put: 2191 prog = event->prog; 2192 event->prog = NULL; 2193 2194 unlock: 2195 mutex_unlock(&bpf_event_mutex); 2196 2197 if (prog) { 2198 /* 2199 * It could be that the bpf_prog is not sleepable (and will be freed 2200 * via normal RCU), but is called from a point that supports sleepable 2201 * programs and uses tasks-trace-RCU. 2202 */ 2203 synchronize_rcu_tasks_trace(); 2204 2205 bpf_prog_put(prog); 2206 } 2207 } 2208 2209 int perf_event_query_prog_array(struct perf_event *event, void __user *info) 2210 { 2211 struct perf_event_query_bpf __user *uquery = info; 2212 struct perf_event_query_bpf query = {}; 2213 struct bpf_prog_array *progs; 2214 u32 *ids, prog_cnt, ids_len; 2215 int ret; 2216 2217 if (!perfmon_capable()) 2218 return -EPERM; 2219 if (event->attr.type != PERF_TYPE_TRACEPOINT) 2220 return -EINVAL; 2221 if (copy_from_user(&query, uquery, sizeof(query))) 2222 return -EFAULT; 2223 2224 ids_len = query.ids_len; 2225 if (ids_len > BPF_TRACE_MAX_PROGS) 2226 return -E2BIG; 2227 ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN); 2228 if (!ids) 2229 return -ENOMEM; 2230 /* 2231 * The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which 2232 * is required when user only wants to check for uquery->prog_cnt. 2233 * There is no need to check for it since the case is handled 2234 * gracefully in bpf_prog_array_copy_info. 2235 */ 2236 2237 mutex_lock(&bpf_event_mutex); 2238 progs = bpf_event_rcu_dereference(event->tp_event->prog_array); 2239 ret = bpf_prog_array_copy_info(progs, ids, ids_len, &prog_cnt); 2240 mutex_unlock(&bpf_event_mutex); 2241 2242 if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) || 2243 copy_to_user(uquery->ids, ids, ids_len * sizeof(u32))) 2244 ret = -EFAULT; 2245 2246 kfree(ids); 2247 return ret; 2248 } 2249 2250 extern struct bpf_raw_event_map __start__bpf_raw_tp[]; 2251 extern struct bpf_raw_event_map __stop__bpf_raw_tp[]; 2252 2253 struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name) 2254 { 2255 struct bpf_raw_event_map *btp = __start__bpf_raw_tp; 2256 2257 for (; btp < __stop__bpf_raw_tp; btp++) { 2258 if (!strcmp(btp->tp->name, name)) 2259 return btp; 2260 } 2261 2262 return bpf_get_raw_tracepoint_module(name); 2263 } 2264 2265 void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp) 2266 { 2267 struct module *mod; 2268 2269 guard(rcu)(); 2270 mod = __module_address((unsigned long)btp); 2271 module_put(mod); 2272 } 2273 2274 static __always_inline 2275 void __bpf_trace_run(struct bpf_raw_tp_link *link, u64 *args) 2276 { 2277 struct bpf_prog *prog = link->link.prog; 2278 struct bpf_run_ctx *old_run_ctx; 2279 struct bpf_trace_run_ctx run_ctx; 2280 2281 cant_sleep(); 2282 if (unlikely(this_cpu_inc_return(*(prog->active)) != 1)) { 2283 bpf_prog_inc_misses_counter(prog); 2284 goto out; 2285 } 2286 2287 run_ctx.bpf_cookie = link->cookie; 2288 old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx); 2289 2290 rcu_read_lock(); 2291 (void) bpf_prog_run(prog, args); 2292 rcu_read_unlock(); 2293 2294 bpf_reset_run_ctx(old_run_ctx); 2295 out: 2296 this_cpu_dec(*(prog->active)); 2297 } 2298 2299 #define UNPACK(...) __VA_ARGS__ 2300 #define REPEAT_1(FN, DL, X, ...) FN(X) 2301 #define REPEAT_2(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__) 2302 #define REPEAT_3(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_2(FN, DL, __VA_ARGS__) 2303 #define REPEAT_4(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_3(FN, DL, __VA_ARGS__) 2304 #define REPEAT_5(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_4(FN, DL, __VA_ARGS__) 2305 #define REPEAT_6(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_5(FN, DL, __VA_ARGS__) 2306 #define REPEAT_7(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_6(FN, DL, __VA_ARGS__) 2307 #define REPEAT_8(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_7(FN, DL, __VA_ARGS__) 2308 #define REPEAT_9(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_8(FN, DL, __VA_ARGS__) 2309 #define REPEAT_10(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_9(FN, DL, __VA_ARGS__) 2310 #define REPEAT_11(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_10(FN, DL, __VA_ARGS__) 2311 #define REPEAT_12(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_11(FN, DL, __VA_ARGS__) 2312 #define REPEAT(X, FN, DL, ...) REPEAT_##X(FN, DL, __VA_ARGS__) 2313 2314 #define SARG(X) u64 arg##X 2315 #define COPY(X) args[X] = arg##X 2316 2317 #define __DL_COM (,) 2318 #define __DL_SEM (;) 2319 2320 #define __SEQ_0_11 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 2321 2322 #define BPF_TRACE_DEFN_x(x) \ 2323 void bpf_trace_run##x(struct bpf_raw_tp_link *link, \ 2324 REPEAT(x, SARG, __DL_COM, __SEQ_0_11)) \ 2325 { \ 2326 u64 args[x]; \ 2327 REPEAT(x, COPY, __DL_SEM, __SEQ_0_11); \ 2328 __bpf_trace_run(link, args); \ 2329 } \ 2330 EXPORT_SYMBOL_GPL(bpf_trace_run##x) 2331 BPF_TRACE_DEFN_x(1); 2332 BPF_TRACE_DEFN_x(2); 2333 BPF_TRACE_DEFN_x(3); 2334 BPF_TRACE_DEFN_x(4); 2335 BPF_TRACE_DEFN_x(5); 2336 BPF_TRACE_DEFN_x(6); 2337 BPF_TRACE_DEFN_x(7); 2338 BPF_TRACE_DEFN_x(8); 2339 BPF_TRACE_DEFN_x(9); 2340 BPF_TRACE_DEFN_x(10); 2341 BPF_TRACE_DEFN_x(11); 2342 BPF_TRACE_DEFN_x(12); 2343 2344 int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_raw_tp_link *link) 2345 { 2346 struct tracepoint *tp = btp->tp; 2347 struct bpf_prog *prog = link->link.prog; 2348 2349 /* 2350 * check that program doesn't access arguments beyond what's 2351 * available in this tracepoint 2352 */ 2353 if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64)) 2354 return -EINVAL; 2355 2356 if (prog->aux->max_tp_access > btp->writable_size) 2357 return -EINVAL; 2358 2359 return tracepoint_probe_register_may_exist(tp, (void *)btp->bpf_func, link); 2360 } 2361 2362 int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_raw_tp_link *link) 2363 { 2364 return tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, link); 2365 } 2366 2367 int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id, 2368 u32 *fd_type, const char **buf, 2369 u64 *probe_offset, u64 *probe_addr, 2370 unsigned long *missed) 2371 { 2372 bool is_tracepoint, is_syscall_tp; 2373 struct bpf_prog *prog; 2374 int flags, err = 0; 2375 2376 prog = event->prog; 2377 if (!prog) 2378 return -ENOENT; 2379 2380 /* not supporting BPF_PROG_TYPE_PERF_EVENT yet */ 2381 if (prog->type == BPF_PROG_TYPE_PERF_EVENT) 2382 return -EOPNOTSUPP; 2383 2384 *prog_id = prog->aux->id; 2385 flags = event->tp_event->flags; 2386 is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT; 2387 is_syscall_tp = is_syscall_trace_event(event->tp_event); 2388 2389 if (is_tracepoint || is_syscall_tp) { 2390 *buf = is_tracepoint ? event->tp_event->tp->name 2391 : event->tp_event->name; 2392 /* We allow NULL pointer for tracepoint */ 2393 if (fd_type) 2394 *fd_type = BPF_FD_TYPE_TRACEPOINT; 2395 if (probe_offset) 2396 *probe_offset = 0x0; 2397 if (probe_addr) 2398 *probe_addr = 0x0; 2399 } else { 2400 /* kprobe/uprobe */ 2401 err = -EOPNOTSUPP; 2402 #ifdef CONFIG_KPROBE_EVENTS 2403 if (flags & TRACE_EVENT_FL_KPROBE) 2404 err = bpf_get_kprobe_info(event, fd_type, buf, 2405 probe_offset, probe_addr, missed, 2406 event->attr.type == PERF_TYPE_TRACEPOINT); 2407 #endif 2408 #ifdef CONFIG_UPROBE_EVENTS 2409 if (flags & TRACE_EVENT_FL_UPROBE) 2410 err = bpf_get_uprobe_info(event, fd_type, buf, 2411 probe_offset, probe_addr, 2412 event->attr.type == PERF_TYPE_TRACEPOINT); 2413 #endif 2414 } 2415 2416 return err; 2417 } 2418 2419 static int __init send_signal_irq_work_init(void) 2420 { 2421 int cpu; 2422 struct send_signal_irq_work *work; 2423 2424 for_each_possible_cpu(cpu) { 2425 work = per_cpu_ptr(&send_signal_work, cpu); 2426 init_irq_work(&work->irq_work, do_bpf_send_signal); 2427 } 2428 return 0; 2429 } 2430 2431 subsys_initcall(send_signal_irq_work_init); 2432 2433 #ifdef CONFIG_MODULES 2434 static int bpf_event_notify(struct notifier_block *nb, unsigned long op, 2435 void *module) 2436 { 2437 struct bpf_trace_module *btm, *tmp; 2438 struct module *mod = module; 2439 int ret = 0; 2440 2441 if (mod->num_bpf_raw_events == 0 || 2442 (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING)) 2443 goto out; 2444 2445 mutex_lock(&bpf_module_mutex); 2446 2447 switch (op) { 2448 case MODULE_STATE_COMING: 2449 btm = kzalloc(sizeof(*btm), GFP_KERNEL); 2450 if (btm) { 2451 btm->module = module; 2452 list_add(&btm->list, &bpf_trace_modules); 2453 } else { 2454 ret = -ENOMEM; 2455 } 2456 break; 2457 case MODULE_STATE_GOING: 2458 list_for_each_entry_safe(btm, tmp, &bpf_trace_modules, list) { 2459 if (btm->module == module) { 2460 list_del(&btm->list); 2461 kfree(btm); 2462 break; 2463 } 2464 } 2465 break; 2466 } 2467 2468 mutex_unlock(&bpf_module_mutex); 2469 2470 out: 2471 return notifier_from_errno(ret); 2472 } 2473 2474 static struct notifier_block bpf_module_nb = { 2475 .notifier_call = bpf_event_notify, 2476 }; 2477 2478 static int __init bpf_event_init(void) 2479 { 2480 register_module_notifier(&bpf_module_nb); 2481 return 0; 2482 } 2483 2484 fs_initcall(bpf_event_init); 2485 #endif /* CONFIG_MODULES */ 2486 2487 struct bpf_session_run_ctx { 2488 struct bpf_run_ctx run_ctx; 2489 bool is_return; 2490 void *data; 2491 }; 2492 2493 #ifdef CONFIG_FPROBE 2494 struct bpf_kprobe_multi_link { 2495 struct bpf_link link; 2496 struct fprobe fp; 2497 unsigned long *addrs; 2498 u64 *cookies; 2499 u32 cnt; 2500 u32 mods_cnt; 2501 struct module **mods; 2502 u32 flags; 2503 }; 2504 2505 struct bpf_kprobe_multi_run_ctx { 2506 struct bpf_session_run_ctx session_ctx; 2507 struct bpf_kprobe_multi_link *link; 2508 unsigned long entry_ip; 2509 }; 2510 2511 struct user_syms { 2512 const char **syms; 2513 char *buf; 2514 }; 2515 2516 #ifndef CONFIG_HAVE_FTRACE_REGS_HAVING_PT_REGS 2517 static DEFINE_PER_CPU(struct pt_regs, bpf_kprobe_multi_pt_regs); 2518 #define bpf_kprobe_multi_pt_regs_ptr() this_cpu_ptr(&bpf_kprobe_multi_pt_regs) 2519 #else 2520 #define bpf_kprobe_multi_pt_regs_ptr() (NULL) 2521 #endif 2522 2523 static unsigned long ftrace_get_entry_ip(unsigned long fentry_ip) 2524 { 2525 unsigned long ip = ftrace_get_symaddr(fentry_ip); 2526 2527 return ip ? : fentry_ip; 2528 } 2529 2530 static int copy_user_syms(struct user_syms *us, unsigned long __user *usyms, u32 cnt) 2531 { 2532 unsigned long __user usymbol; 2533 const char **syms = NULL; 2534 char *buf = NULL, *p; 2535 int err = -ENOMEM; 2536 unsigned int i; 2537 2538 syms = kvmalloc_array(cnt, sizeof(*syms), GFP_KERNEL); 2539 if (!syms) 2540 goto error; 2541 2542 buf = kvmalloc_array(cnt, KSYM_NAME_LEN, GFP_KERNEL); 2543 if (!buf) 2544 goto error; 2545 2546 for (p = buf, i = 0; i < cnt; i++) { 2547 if (__get_user(usymbol, usyms + i)) { 2548 err = -EFAULT; 2549 goto error; 2550 } 2551 err = strncpy_from_user(p, (const char __user *) usymbol, KSYM_NAME_LEN); 2552 if (err == KSYM_NAME_LEN) 2553 err = -E2BIG; 2554 if (err < 0) 2555 goto error; 2556 syms[i] = p; 2557 p += err + 1; 2558 } 2559 2560 us->syms = syms; 2561 us->buf = buf; 2562 return 0; 2563 2564 error: 2565 if (err) { 2566 kvfree(syms); 2567 kvfree(buf); 2568 } 2569 return err; 2570 } 2571 2572 static void kprobe_multi_put_modules(struct module **mods, u32 cnt) 2573 { 2574 u32 i; 2575 2576 for (i = 0; i < cnt; i++) 2577 module_put(mods[i]); 2578 } 2579 2580 static void free_user_syms(struct user_syms *us) 2581 { 2582 kvfree(us->syms); 2583 kvfree(us->buf); 2584 } 2585 2586 static void bpf_kprobe_multi_link_release(struct bpf_link *link) 2587 { 2588 struct bpf_kprobe_multi_link *kmulti_link; 2589 2590 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); 2591 unregister_fprobe(&kmulti_link->fp); 2592 kprobe_multi_put_modules(kmulti_link->mods, kmulti_link->mods_cnt); 2593 } 2594 2595 static void bpf_kprobe_multi_link_dealloc(struct bpf_link *link) 2596 { 2597 struct bpf_kprobe_multi_link *kmulti_link; 2598 2599 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); 2600 kvfree(kmulti_link->addrs); 2601 kvfree(kmulti_link->cookies); 2602 kfree(kmulti_link->mods); 2603 kfree(kmulti_link); 2604 } 2605 2606 static int bpf_kprobe_multi_link_fill_link_info(const struct bpf_link *link, 2607 struct bpf_link_info *info) 2608 { 2609 u64 __user *ucookies = u64_to_user_ptr(info->kprobe_multi.cookies); 2610 u64 __user *uaddrs = u64_to_user_ptr(info->kprobe_multi.addrs); 2611 struct bpf_kprobe_multi_link *kmulti_link; 2612 u32 ucount = info->kprobe_multi.count; 2613 int err = 0, i; 2614 2615 if (!uaddrs ^ !ucount) 2616 return -EINVAL; 2617 if (ucookies && !ucount) 2618 return -EINVAL; 2619 2620 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); 2621 info->kprobe_multi.count = kmulti_link->cnt; 2622 info->kprobe_multi.flags = kmulti_link->flags; 2623 info->kprobe_multi.missed = kmulti_link->fp.nmissed; 2624 2625 if (!uaddrs) 2626 return 0; 2627 if (ucount < kmulti_link->cnt) 2628 err = -ENOSPC; 2629 else 2630 ucount = kmulti_link->cnt; 2631 2632 if (ucookies) { 2633 if (kmulti_link->cookies) { 2634 if (copy_to_user(ucookies, kmulti_link->cookies, ucount * sizeof(u64))) 2635 return -EFAULT; 2636 } else { 2637 for (i = 0; i < ucount; i++) { 2638 if (put_user(0, ucookies + i)) 2639 return -EFAULT; 2640 } 2641 } 2642 } 2643 2644 if (kallsyms_show_value(current_cred())) { 2645 if (copy_to_user(uaddrs, kmulti_link->addrs, ucount * sizeof(u64))) 2646 return -EFAULT; 2647 } else { 2648 for (i = 0; i < ucount; i++) { 2649 if (put_user(0, uaddrs + i)) 2650 return -EFAULT; 2651 } 2652 } 2653 return err; 2654 } 2655 2656 static const struct bpf_link_ops bpf_kprobe_multi_link_lops = { 2657 .release = bpf_kprobe_multi_link_release, 2658 .dealloc_deferred = bpf_kprobe_multi_link_dealloc, 2659 .fill_link_info = bpf_kprobe_multi_link_fill_link_info, 2660 }; 2661 2662 static void bpf_kprobe_multi_cookie_swap(void *a, void *b, int size, const void *priv) 2663 { 2664 const struct bpf_kprobe_multi_link *link = priv; 2665 unsigned long *addr_a = a, *addr_b = b; 2666 u64 *cookie_a, *cookie_b; 2667 2668 cookie_a = link->cookies + (addr_a - link->addrs); 2669 cookie_b = link->cookies + (addr_b - link->addrs); 2670 2671 /* swap addr_a/addr_b and cookie_a/cookie_b values */ 2672 swap(*addr_a, *addr_b); 2673 swap(*cookie_a, *cookie_b); 2674 } 2675 2676 static int bpf_kprobe_multi_addrs_cmp(const void *a, const void *b) 2677 { 2678 const unsigned long *addr_a = a, *addr_b = b; 2679 2680 if (*addr_a == *addr_b) 2681 return 0; 2682 return *addr_a < *addr_b ? -1 : 1; 2683 } 2684 2685 static int bpf_kprobe_multi_cookie_cmp(const void *a, const void *b, const void *priv) 2686 { 2687 return bpf_kprobe_multi_addrs_cmp(a, b); 2688 } 2689 2690 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx) 2691 { 2692 struct bpf_kprobe_multi_run_ctx *run_ctx; 2693 struct bpf_kprobe_multi_link *link; 2694 u64 *cookie, entry_ip; 2695 unsigned long *addr; 2696 2697 if (WARN_ON_ONCE(!ctx)) 2698 return 0; 2699 run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, 2700 session_ctx.run_ctx); 2701 link = run_ctx->link; 2702 if (!link->cookies) 2703 return 0; 2704 entry_ip = run_ctx->entry_ip; 2705 addr = bsearch(&entry_ip, link->addrs, link->cnt, sizeof(entry_ip), 2706 bpf_kprobe_multi_addrs_cmp); 2707 if (!addr) 2708 return 0; 2709 cookie = link->cookies + (addr - link->addrs); 2710 return *cookie; 2711 } 2712 2713 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 2714 { 2715 struct bpf_kprobe_multi_run_ctx *run_ctx; 2716 2717 run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, 2718 session_ctx.run_ctx); 2719 return run_ctx->entry_ip; 2720 } 2721 2722 static int 2723 kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link, 2724 unsigned long entry_ip, struct ftrace_regs *fregs, 2725 bool is_return, void *data) 2726 { 2727 struct bpf_kprobe_multi_run_ctx run_ctx = { 2728 .session_ctx = { 2729 .is_return = is_return, 2730 .data = data, 2731 }, 2732 .link = link, 2733 .entry_ip = entry_ip, 2734 }; 2735 struct bpf_run_ctx *old_run_ctx; 2736 struct pt_regs *regs; 2737 int err; 2738 2739 if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) { 2740 bpf_prog_inc_misses_counter(link->link.prog); 2741 err = 1; 2742 goto out; 2743 } 2744 2745 migrate_disable(); 2746 rcu_read_lock(); 2747 regs = ftrace_partial_regs(fregs, bpf_kprobe_multi_pt_regs_ptr()); 2748 old_run_ctx = bpf_set_run_ctx(&run_ctx.session_ctx.run_ctx); 2749 err = bpf_prog_run(link->link.prog, regs); 2750 bpf_reset_run_ctx(old_run_ctx); 2751 rcu_read_unlock(); 2752 migrate_enable(); 2753 2754 out: 2755 __this_cpu_dec(bpf_prog_active); 2756 return err; 2757 } 2758 2759 static int 2760 kprobe_multi_link_handler(struct fprobe *fp, unsigned long fentry_ip, 2761 unsigned long ret_ip, struct ftrace_regs *fregs, 2762 void *data) 2763 { 2764 struct bpf_kprobe_multi_link *link; 2765 int err; 2766 2767 link = container_of(fp, struct bpf_kprobe_multi_link, fp); 2768 err = kprobe_multi_link_prog_run(link, ftrace_get_entry_ip(fentry_ip), 2769 fregs, false, data); 2770 return is_kprobe_session(link->link.prog) ? err : 0; 2771 } 2772 2773 static void 2774 kprobe_multi_link_exit_handler(struct fprobe *fp, unsigned long fentry_ip, 2775 unsigned long ret_ip, struct ftrace_regs *fregs, 2776 void *data) 2777 { 2778 struct bpf_kprobe_multi_link *link; 2779 2780 link = container_of(fp, struct bpf_kprobe_multi_link, fp); 2781 kprobe_multi_link_prog_run(link, ftrace_get_entry_ip(fentry_ip), 2782 fregs, true, data); 2783 } 2784 2785 static int symbols_cmp_r(const void *a, const void *b, const void *priv) 2786 { 2787 const char **str_a = (const char **) a; 2788 const char **str_b = (const char **) b; 2789 2790 return strcmp(*str_a, *str_b); 2791 } 2792 2793 struct multi_symbols_sort { 2794 const char **funcs; 2795 u64 *cookies; 2796 }; 2797 2798 static void symbols_swap_r(void *a, void *b, int size, const void *priv) 2799 { 2800 const struct multi_symbols_sort *data = priv; 2801 const char **name_a = a, **name_b = b; 2802 2803 swap(*name_a, *name_b); 2804 2805 /* If defined, swap also related cookies. */ 2806 if (data->cookies) { 2807 u64 *cookie_a, *cookie_b; 2808 2809 cookie_a = data->cookies + (name_a - data->funcs); 2810 cookie_b = data->cookies + (name_b - data->funcs); 2811 swap(*cookie_a, *cookie_b); 2812 } 2813 } 2814 2815 struct modules_array { 2816 struct module **mods; 2817 int mods_cnt; 2818 int mods_cap; 2819 }; 2820 2821 static int add_module(struct modules_array *arr, struct module *mod) 2822 { 2823 struct module **mods; 2824 2825 if (arr->mods_cnt == arr->mods_cap) { 2826 arr->mods_cap = max(16, arr->mods_cap * 3 / 2); 2827 mods = krealloc_array(arr->mods, arr->mods_cap, sizeof(*mods), GFP_KERNEL); 2828 if (!mods) 2829 return -ENOMEM; 2830 arr->mods = mods; 2831 } 2832 2833 arr->mods[arr->mods_cnt] = mod; 2834 arr->mods_cnt++; 2835 return 0; 2836 } 2837 2838 static bool has_module(struct modules_array *arr, struct module *mod) 2839 { 2840 int i; 2841 2842 for (i = arr->mods_cnt - 1; i >= 0; i--) { 2843 if (arr->mods[i] == mod) 2844 return true; 2845 } 2846 return false; 2847 } 2848 2849 static int get_modules_for_addrs(struct module ***mods, unsigned long *addrs, u32 addrs_cnt) 2850 { 2851 struct modules_array arr = {}; 2852 u32 i, err = 0; 2853 2854 for (i = 0; i < addrs_cnt; i++) { 2855 bool skip_add = false; 2856 struct module *mod; 2857 2858 scoped_guard(rcu) { 2859 mod = __module_address(addrs[i]); 2860 /* Either no module or it's already stored */ 2861 if (!mod || has_module(&arr, mod)) { 2862 skip_add = true; 2863 break; /* scoped_guard */ 2864 } 2865 if (!try_module_get(mod)) 2866 err = -EINVAL; 2867 } 2868 if (skip_add) 2869 continue; 2870 if (err) 2871 break; 2872 err = add_module(&arr, mod); 2873 if (err) { 2874 module_put(mod); 2875 break; 2876 } 2877 } 2878 2879 /* We return either err < 0 in case of error, ... */ 2880 if (err) { 2881 kprobe_multi_put_modules(arr.mods, arr.mods_cnt); 2882 kfree(arr.mods); 2883 return err; 2884 } 2885 2886 /* or number of modules found if everything is ok. */ 2887 *mods = arr.mods; 2888 return arr.mods_cnt; 2889 } 2890 2891 static int addrs_check_error_injection_list(unsigned long *addrs, u32 cnt) 2892 { 2893 u32 i; 2894 2895 for (i = 0; i < cnt; i++) { 2896 if (!within_error_injection_list(addrs[i])) 2897 return -EINVAL; 2898 } 2899 return 0; 2900 } 2901 2902 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 2903 { 2904 struct bpf_kprobe_multi_link *link = NULL; 2905 struct bpf_link_primer link_primer; 2906 void __user *ucookies; 2907 unsigned long *addrs; 2908 u32 flags, cnt, size; 2909 void __user *uaddrs; 2910 u64 *cookies = NULL; 2911 void __user *usyms; 2912 int err; 2913 2914 /* no support for 32bit archs yet */ 2915 if (sizeof(u64) != sizeof(void *)) 2916 return -EOPNOTSUPP; 2917 2918 if (attr->link_create.flags) 2919 return -EINVAL; 2920 2921 if (!is_kprobe_multi(prog)) 2922 return -EINVAL; 2923 2924 flags = attr->link_create.kprobe_multi.flags; 2925 if (flags & ~BPF_F_KPROBE_MULTI_RETURN) 2926 return -EINVAL; 2927 2928 uaddrs = u64_to_user_ptr(attr->link_create.kprobe_multi.addrs); 2929 usyms = u64_to_user_ptr(attr->link_create.kprobe_multi.syms); 2930 if (!!uaddrs == !!usyms) 2931 return -EINVAL; 2932 2933 cnt = attr->link_create.kprobe_multi.cnt; 2934 if (!cnt) 2935 return -EINVAL; 2936 if (cnt > MAX_KPROBE_MULTI_CNT) 2937 return -E2BIG; 2938 2939 size = cnt * sizeof(*addrs); 2940 addrs = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL); 2941 if (!addrs) 2942 return -ENOMEM; 2943 2944 ucookies = u64_to_user_ptr(attr->link_create.kprobe_multi.cookies); 2945 if (ucookies) { 2946 cookies = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL); 2947 if (!cookies) { 2948 err = -ENOMEM; 2949 goto error; 2950 } 2951 if (copy_from_user(cookies, ucookies, size)) { 2952 err = -EFAULT; 2953 goto error; 2954 } 2955 } 2956 2957 if (uaddrs) { 2958 if (copy_from_user(addrs, uaddrs, size)) { 2959 err = -EFAULT; 2960 goto error; 2961 } 2962 } else { 2963 struct multi_symbols_sort data = { 2964 .cookies = cookies, 2965 }; 2966 struct user_syms us; 2967 2968 err = copy_user_syms(&us, usyms, cnt); 2969 if (err) 2970 goto error; 2971 2972 if (cookies) 2973 data.funcs = us.syms; 2974 2975 sort_r(us.syms, cnt, sizeof(*us.syms), symbols_cmp_r, 2976 symbols_swap_r, &data); 2977 2978 err = ftrace_lookup_symbols(us.syms, cnt, addrs); 2979 free_user_syms(&us); 2980 if (err) 2981 goto error; 2982 } 2983 2984 if (prog->kprobe_override && addrs_check_error_injection_list(addrs, cnt)) { 2985 err = -EINVAL; 2986 goto error; 2987 } 2988 2989 link = kzalloc(sizeof(*link), GFP_KERNEL); 2990 if (!link) { 2991 err = -ENOMEM; 2992 goto error; 2993 } 2994 2995 bpf_link_init(&link->link, BPF_LINK_TYPE_KPROBE_MULTI, 2996 &bpf_kprobe_multi_link_lops, prog); 2997 2998 err = bpf_link_prime(&link->link, &link_primer); 2999 if (err) 3000 goto error; 3001 3002 if (!(flags & BPF_F_KPROBE_MULTI_RETURN)) 3003 link->fp.entry_handler = kprobe_multi_link_handler; 3004 if ((flags & BPF_F_KPROBE_MULTI_RETURN) || is_kprobe_session(prog)) 3005 link->fp.exit_handler = kprobe_multi_link_exit_handler; 3006 if (is_kprobe_session(prog)) 3007 link->fp.entry_data_size = sizeof(u64); 3008 3009 link->addrs = addrs; 3010 link->cookies = cookies; 3011 link->cnt = cnt; 3012 link->flags = flags; 3013 3014 if (cookies) { 3015 /* 3016 * Sorting addresses will trigger sorting cookies as well 3017 * (check bpf_kprobe_multi_cookie_swap). This way we can 3018 * find cookie based on the address in bpf_get_attach_cookie 3019 * helper. 3020 */ 3021 sort_r(addrs, cnt, sizeof(*addrs), 3022 bpf_kprobe_multi_cookie_cmp, 3023 bpf_kprobe_multi_cookie_swap, 3024 link); 3025 } 3026 3027 err = get_modules_for_addrs(&link->mods, addrs, cnt); 3028 if (err < 0) { 3029 bpf_link_cleanup(&link_primer); 3030 return err; 3031 } 3032 link->mods_cnt = err; 3033 3034 err = register_fprobe_ips(&link->fp, addrs, cnt); 3035 if (err) { 3036 kprobe_multi_put_modules(link->mods, link->mods_cnt); 3037 bpf_link_cleanup(&link_primer); 3038 return err; 3039 } 3040 3041 return bpf_link_settle(&link_primer); 3042 3043 error: 3044 kfree(link); 3045 kvfree(addrs); 3046 kvfree(cookies); 3047 return err; 3048 } 3049 #else /* !CONFIG_FPROBE */ 3050 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 3051 { 3052 return -EOPNOTSUPP; 3053 } 3054 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx) 3055 { 3056 return 0; 3057 } 3058 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 3059 { 3060 return 0; 3061 } 3062 #endif 3063 3064 #ifdef CONFIG_UPROBES 3065 struct bpf_uprobe_multi_link; 3066 3067 struct bpf_uprobe { 3068 struct bpf_uprobe_multi_link *link; 3069 loff_t offset; 3070 unsigned long ref_ctr_offset; 3071 u64 cookie; 3072 struct uprobe *uprobe; 3073 struct uprobe_consumer consumer; 3074 bool session; 3075 }; 3076 3077 struct bpf_uprobe_multi_link { 3078 struct path path; 3079 struct bpf_link link; 3080 u32 cnt; 3081 u32 flags; 3082 struct bpf_uprobe *uprobes; 3083 struct task_struct *task; 3084 }; 3085 3086 struct bpf_uprobe_multi_run_ctx { 3087 struct bpf_session_run_ctx session_ctx; 3088 unsigned long entry_ip; 3089 struct bpf_uprobe *uprobe; 3090 }; 3091 3092 static void bpf_uprobe_unregister(struct bpf_uprobe *uprobes, u32 cnt) 3093 { 3094 u32 i; 3095 3096 for (i = 0; i < cnt; i++) 3097 uprobe_unregister_nosync(uprobes[i].uprobe, &uprobes[i].consumer); 3098 3099 if (cnt) 3100 uprobe_unregister_sync(); 3101 } 3102 3103 static void bpf_uprobe_multi_link_release(struct bpf_link *link) 3104 { 3105 struct bpf_uprobe_multi_link *umulti_link; 3106 3107 umulti_link = container_of(link, struct bpf_uprobe_multi_link, link); 3108 bpf_uprobe_unregister(umulti_link->uprobes, umulti_link->cnt); 3109 if (umulti_link->task) 3110 put_task_struct(umulti_link->task); 3111 path_put(&umulti_link->path); 3112 } 3113 3114 static void bpf_uprobe_multi_link_dealloc(struct bpf_link *link) 3115 { 3116 struct bpf_uprobe_multi_link *umulti_link; 3117 3118 umulti_link = container_of(link, struct bpf_uprobe_multi_link, link); 3119 kvfree(umulti_link->uprobes); 3120 kfree(umulti_link); 3121 } 3122 3123 static int bpf_uprobe_multi_link_fill_link_info(const struct bpf_link *link, 3124 struct bpf_link_info *info) 3125 { 3126 u64 __user *uref_ctr_offsets = u64_to_user_ptr(info->uprobe_multi.ref_ctr_offsets); 3127 u64 __user *ucookies = u64_to_user_ptr(info->uprobe_multi.cookies); 3128 u64 __user *uoffsets = u64_to_user_ptr(info->uprobe_multi.offsets); 3129 u64 __user *upath = u64_to_user_ptr(info->uprobe_multi.path); 3130 u32 upath_size = info->uprobe_multi.path_size; 3131 struct bpf_uprobe_multi_link *umulti_link; 3132 u32 ucount = info->uprobe_multi.count; 3133 int err = 0, i; 3134 char *p, *buf; 3135 long left = 0; 3136 3137 if (!upath ^ !upath_size) 3138 return -EINVAL; 3139 3140 if ((uoffsets || uref_ctr_offsets || ucookies) && !ucount) 3141 return -EINVAL; 3142 3143 umulti_link = container_of(link, struct bpf_uprobe_multi_link, link); 3144 info->uprobe_multi.count = umulti_link->cnt; 3145 info->uprobe_multi.flags = umulti_link->flags; 3146 info->uprobe_multi.pid = umulti_link->task ? 3147 task_pid_nr_ns(umulti_link->task, task_active_pid_ns(current)) : 0; 3148 3149 upath_size = upath_size ? min_t(u32, upath_size, PATH_MAX) : PATH_MAX; 3150 buf = kmalloc(upath_size, GFP_KERNEL); 3151 if (!buf) 3152 return -ENOMEM; 3153 p = d_path(&umulti_link->path, buf, upath_size); 3154 if (IS_ERR(p)) { 3155 kfree(buf); 3156 return PTR_ERR(p); 3157 } 3158 upath_size = buf + upath_size - p; 3159 3160 if (upath) 3161 left = copy_to_user(upath, p, upath_size); 3162 kfree(buf); 3163 if (left) 3164 return -EFAULT; 3165 info->uprobe_multi.path_size = upath_size; 3166 3167 if (!uoffsets && !ucookies && !uref_ctr_offsets) 3168 return 0; 3169 3170 if (ucount < umulti_link->cnt) 3171 err = -ENOSPC; 3172 else 3173 ucount = umulti_link->cnt; 3174 3175 for (i = 0; i < ucount; i++) { 3176 if (uoffsets && 3177 put_user(umulti_link->uprobes[i].offset, uoffsets + i)) 3178 return -EFAULT; 3179 if (uref_ctr_offsets && 3180 put_user(umulti_link->uprobes[i].ref_ctr_offset, uref_ctr_offsets + i)) 3181 return -EFAULT; 3182 if (ucookies && 3183 put_user(umulti_link->uprobes[i].cookie, ucookies + i)) 3184 return -EFAULT; 3185 } 3186 3187 return err; 3188 } 3189 3190 static const struct bpf_link_ops bpf_uprobe_multi_link_lops = { 3191 .release = bpf_uprobe_multi_link_release, 3192 .dealloc_deferred = bpf_uprobe_multi_link_dealloc, 3193 .fill_link_info = bpf_uprobe_multi_link_fill_link_info, 3194 }; 3195 3196 static int uprobe_prog_run(struct bpf_uprobe *uprobe, 3197 unsigned long entry_ip, 3198 struct pt_regs *regs, 3199 bool is_return, void *data) 3200 { 3201 struct bpf_uprobe_multi_link *link = uprobe->link; 3202 struct bpf_uprobe_multi_run_ctx run_ctx = { 3203 .session_ctx = { 3204 .is_return = is_return, 3205 .data = data, 3206 }, 3207 .entry_ip = entry_ip, 3208 .uprobe = uprobe, 3209 }; 3210 struct bpf_prog *prog = link->link.prog; 3211 bool sleepable = prog->sleepable; 3212 struct bpf_run_ctx *old_run_ctx; 3213 int err; 3214 3215 if (link->task && !same_thread_group(current, link->task)) 3216 return 0; 3217 3218 if (sleepable) 3219 rcu_read_lock_trace(); 3220 else 3221 rcu_read_lock(); 3222 3223 migrate_disable(); 3224 3225 old_run_ctx = bpf_set_run_ctx(&run_ctx.session_ctx.run_ctx); 3226 err = bpf_prog_run(link->link.prog, regs); 3227 bpf_reset_run_ctx(old_run_ctx); 3228 3229 migrate_enable(); 3230 3231 if (sleepable) 3232 rcu_read_unlock_trace(); 3233 else 3234 rcu_read_unlock(); 3235 return err; 3236 } 3237 3238 static bool 3239 uprobe_multi_link_filter(struct uprobe_consumer *con, struct mm_struct *mm) 3240 { 3241 struct bpf_uprobe *uprobe; 3242 3243 uprobe = container_of(con, struct bpf_uprobe, consumer); 3244 return uprobe->link->task->mm == mm; 3245 } 3246 3247 static int 3248 uprobe_multi_link_handler(struct uprobe_consumer *con, struct pt_regs *regs, 3249 __u64 *data) 3250 { 3251 struct bpf_uprobe *uprobe; 3252 int ret; 3253 3254 uprobe = container_of(con, struct bpf_uprobe, consumer); 3255 ret = uprobe_prog_run(uprobe, instruction_pointer(regs), regs, false, data); 3256 if (uprobe->session) 3257 return ret ? UPROBE_HANDLER_IGNORE : 0; 3258 return 0; 3259 } 3260 3261 static int 3262 uprobe_multi_link_ret_handler(struct uprobe_consumer *con, unsigned long func, struct pt_regs *regs, 3263 __u64 *data) 3264 { 3265 struct bpf_uprobe *uprobe; 3266 3267 uprobe = container_of(con, struct bpf_uprobe, consumer); 3268 uprobe_prog_run(uprobe, func, regs, true, data); 3269 return 0; 3270 } 3271 3272 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 3273 { 3274 struct bpf_uprobe_multi_run_ctx *run_ctx; 3275 3276 run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx, 3277 session_ctx.run_ctx); 3278 return run_ctx->entry_ip; 3279 } 3280 3281 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx) 3282 { 3283 struct bpf_uprobe_multi_run_ctx *run_ctx; 3284 3285 run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx, 3286 session_ctx.run_ctx); 3287 return run_ctx->uprobe->cookie; 3288 } 3289 3290 int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 3291 { 3292 struct bpf_uprobe_multi_link *link = NULL; 3293 unsigned long __user *uref_ctr_offsets; 3294 struct bpf_link_primer link_primer; 3295 struct bpf_uprobe *uprobes = NULL; 3296 struct task_struct *task = NULL; 3297 unsigned long __user *uoffsets; 3298 u64 __user *ucookies; 3299 void __user *upath; 3300 u32 flags, cnt, i; 3301 struct path path; 3302 char *name; 3303 pid_t pid; 3304 int err; 3305 3306 /* no support for 32bit archs yet */ 3307 if (sizeof(u64) != sizeof(void *)) 3308 return -EOPNOTSUPP; 3309 3310 if (attr->link_create.flags) 3311 return -EINVAL; 3312 3313 if (!is_uprobe_multi(prog)) 3314 return -EINVAL; 3315 3316 flags = attr->link_create.uprobe_multi.flags; 3317 if (flags & ~BPF_F_UPROBE_MULTI_RETURN) 3318 return -EINVAL; 3319 3320 /* 3321 * path, offsets and cnt are mandatory, 3322 * ref_ctr_offsets and cookies are optional 3323 */ 3324 upath = u64_to_user_ptr(attr->link_create.uprobe_multi.path); 3325 uoffsets = u64_to_user_ptr(attr->link_create.uprobe_multi.offsets); 3326 cnt = attr->link_create.uprobe_multi.cnt; 3327 pid = attr->link_create.uprobe_multi.pid; 3328 3329 if (!upath || !uoffsets || !cnt || pid < 0) 3330 return -EINVAL; 3331 if (cnt > MAX_UPROBE_MULTI_CNT) 3332 return -E2BIG; 3333 3334 uref_ctr_offsets = u64_to_user_ptr(attr->link_create.uprobe_multi.ref_ctr_offsets); 3335 ucookies = u64_to_user_ptr(attr->link_create.uprobe_multi.cookies); 3336 3337 name = strndup_user(upath, PATH_MAX); 3338 if (IS_ERR(name)) { 3339 err = PTR_ERR(name); 3340 return err; 3341 } 3342 3343 err = kern_path(name, LOOKUP_FOLLOW, &path); 3344 kfree(name); 3345 if (err) 3346 return err; 3347 3348 if (!d_is_reg(path.dentry)) { 3349 err = -EBADF; 3350 goto error_path_put; 3351 } 3352 3353 if (pid) { 3354 task = get_pid_task(find_vpid(pid), PIDTYPE_TGID); 3355 if (!task) { 3356 err = -ESRCH; 3357 goto error_path_put; 3358 } 3359 } 3360 3361 err = -ENOMEM; 3362 3363 link = kzalloc(sizeof(*link), GFP_KERNEL); 3364 uprobes = kvcalloc(cnt, sizeof(*uprobes), GFP_KERNEL); 3365 3366 if (!uprobes || !link) 3367 goto error_free; 3368 3369 for (i = 0; i < cnt; i++) { 3370 if (__get_user(uprobes[i].offset, uoffsets + i)) { 3371 err = -EFAULT; 3372 goto error_free; 3373 } 3374 if (uprobes[i].offset < 0) { 3375 err = -EINVAL; 3376 goto error_free; 3377 } 3378 if (uref_ctr_offsets && __get_user(uprobes[i].ref_ctr_offset, uref_ctr_offsets + i)) { 3379 err = -EFAULT; 3380 goto error_free; 3381 } 3382 if (ucookies && __get_user(uprobes[i].cookie, ucookies + i)) { 3383 err = -EFAULT; 3384 goto error_free; 3385 } 3386 3387 uprobes[i].link = link; 3388 3389 if (!(flags & BPF_F_UPROBE_MULTI_RETURN)) 3390 uprobes[i].consumer.handler = uprobe_multi_link_handler; 3391 if (flags & BPF_F_UPROBE_MULTI_RETURN || is_uprobe_session(prog)) 3392 uprobes[i].consumer.ret_handler = uprobe_multi_link_ret_handler; 3393 if (is_uprobe_session(prog)) 3394 uprobes[i].session = true; 3395 if (pid) 3396 uprobes[i].consumer.filter = uprobe_multi_link_filter; 3397 } 3398 3399 link->cnt = cnt; 3400 link->uprobes = uprobes; 3401 link->path = path; 3402 link->task = task; 3403 link->flags = flags; 3404 3405 bpf_link_init(&link->link, BPF_LINK_TYPE_UPROBE_MULTI, 3406 &bpf_uprobe_multi_link_lops, prog); 3407 3408 for (i = 0; i < cnt; i++) { 3409 uprobes[i].uprobe = uprobe_register(d_real_inode(link->path.dentry), 3410 uprobes[i].offset, 3411 uprobes[i].ref_ctr_offset, 3412 &uprobes[i].consumer); 3413 if (IS_ERR(uprobes[i].uprobe)) { 3414 err = PTR_ERR(uprobes[i].uprobe); 3415 link->cnt = i; 3416 goto error_unregister; 3417 } 3418 } 3419 3420 err = bpf_link_prime(&link->link, &link_primer); 3421 if (err) 3422 goto error_unregister; 3423 3424 return bpf_link_settle(&link_primer); 3425 3426 error_unregister: 3427 bpf_uprobe_unregister(uprobes, link->cnt); 3428 3429 error_free: 3430 kvfree(uprobes); 3431 kfree(link); 3432 if (task) 3433 put_task_struct(task); 3434 error_path_put: 3435 path_put(&path); 3436 return err; 3437 } 3438 #else /* !CONFIG_UPROBES */ 3439 int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 3440 { 3441 return -EOPNOTSUPP; 3442 } 3443 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx) 3444 { 3445 return 0; 3446 } 3447 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 3448 { 3449 return 0; 3450 } 3451 #endif /* CONFIG_UPROBES */ 3452 3453 __bpf_kfunc_start_defs(); 3454 3455 __bpf_kfunc bool bpf_session_is_return(void) 3456 { 3457 struct bpf_session_run_ctx *session_ctx; 3458 3459 session_ctx = container_of(current->bpf_ctx, struct bpf_session_run_ctx, run_ctx); 3460 return session_ctx->is_return; 3461 } 3462 3463 __bpf_kfunc __u64 *bpf_session_cookie(void) 3464 { 3465 struct bpf_session_run_ctx *session_ctx; 3466 3467 session_ctx = container_of(current->bpf_ctx, struct bpf_session_run_ctx, run_ctx); 3468 return session_ctx->data; 3469 } 3470 3471 __bpf_kfunc_end_defs(); 3472 3473 BTF_KFUNCS_START(kprobe_multi_kfunc_set_ids) 3474 BTF_ID_FLAGS(func, bpf_session_is_return) 3475 BTF_ID_FLAGS(func, bpf_session_cookie) 3476 BTF_KFUNCS_END(kprobe_multi_kfunc_set_ids) 3477 3478 static int bpf_kprobe_multi_filter(const struct bpf_prog *prog, u32 kfunc_id) 3479 { 3480 if (!btf_id_set8_contains(&kprobe_multi_kfunc_set_ids, kfunc_id)) 3481 return 0; 3482 3483 if (!is_kprobe_session(prog) && !is_uprobe_session(prog)) 3484 return -EACCES; 3485 3486 return 0; 3487 } 3488 3489 static const struct btf_kfunc_id_set bpf_kprobe_multi_kfunc_set = { 3490 .owner = THIS_MODULE, 3491 .set = &kprobe_multi_kfunc_set_ids, 3492 .filter = bpf_kprobe_multi_filter, 3493 }; 3494 3495 static int __init bpf_kprobe_multi_kfuncs_init(void) 3496 { 3497 return register_btf_kfunc_id_set(BPF_PROG_TYPE_KPROBE, &bpf_kprobe_multi_kfunc_set); 3498 } 3499 3500 late_initcall(bpf_kprobe_multi_kfuncs_init); 3501 3502 __bpf_kfunc_start_defs(); 3503 3504 __bpf_kfunc int bpf_send_signal_task(struct task_struct *task, int sig, enum pid_type type, 3505 u64 value) 3506 { 3507 if (type != PIDTYPE_PID && type != PIDTYPE_TGID) 3508 return -EINVAL; 3509 3510 return bpf_send_signal_common(sig, type, task, value); 3511 } 3512 3513 __bpf_kfunc_end_defs(); 3514