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/namei.h> 26 27 #include <net/bpf_sk_storage.h> 28 29 #include <uapi/linux/bpf.h> 30 #include <uapi/linux/btf.h> 31 32 #include <asm/tlb.h> 33 34 #include "trace_probe.h" 35 #include "trace.h" 36 37 #define CREATE_TRACE_POINTS 38 #include "bpf_trace.h" 39 40 #define bpf_event_rcu_dereference(p) \ 41 rcu_dereference_protected(p, lockdep_is_held(&bpf_event_mutex)) 42 43 #define MAX_UPROBE_MULTI_CNT (1U << 20) 44 #define MAX_KPROBE_MULTI_CNT (1U << 20) 45 46 #ifdef CONFIG_MODULES 47 struct bpf_trace_module { 48 struct module *module; 49 struct list_head list; 50 }; 51 52 static LIST_HEAD(bpf_trace_modules); 53 static DEFINE_MUTEX(bpf_module_mutex); 54 55 static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name) 56 { 57 struct bpf_raw_event_map *btp, *ret = NULL; 58 struct bpf_trace_module *btm; 59 unsigned int i; 60 61 mutex_lock(&bpf_module_mutex); 62 list_for_each_entry(btm, &bpf_trace_modules, list) { 63 for (i = 0; i < btm->module->num_bpf_raw_events; ++i) { 64 btp = &btm->module->bpf_raw_events[i]; 65 if (!strcmp(btp->tp->name, name)) { 66 if (try_module_get(btm->module)) 67 ret = btp; 68 goto out; 69 } 70 } 71 } 72 out: 73 mutex_unlock(&bpf_module_mutex); 74 return ret; 75 } 76 #else 77 static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name) 78 { 79 return NULL; 80 } 81 #endif /* CONFIG_MODULES */ 82 83 u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); 84 u64 bpf_get_stack(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); 85 86 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size, 87 u64 flags, const struct btf **btf, 88 s32 *btf_id); 89 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx); 90 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx); 91 92 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx); 93 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx); 94 95 /** 96 * trace_call_bpf - invoke BPF program 97 * @call: tracepoint event 98 * @ctx: opaque context pointer 99 * 100 * kprobe handlers execute BPF programs via this helper. 101 * Can be used from static tracepoints in the future. 102 * 103 * Return: BPF programs always return an integer which is interpreted by 104 * kprobe handler as: 105 * 0 - return from kprobe (event is filtered out) 106 * 1 - store kprobe event into ring buffer 107 * Other values are reserved and currently alias to 1 108 */ 109 unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx) 110 { 111 unsigned int ret; 112 113 cant_sleep(); 114 115 if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) { 116 /* 117 * since some bpf program is already running on this cpu, 118 * don't call into another bpf program (same or different) 119 * and don't send kprobe event into ring-buffer, 120 * so return zero here 121 */ 122 rcu_read_lock(); 123 bpf_prog_inc_misses_counters(rcu_dereference(call->prog_array)); 124 rcu_read_unlock(); 125 ret = 0; 126 goto out; 127 } 128 129 /* 130 * Instead of moving rcu_read_lock/rcu_dereference/rcu_read_unlock 131 * to all call sites, we did a bpf_prog_array_valid() there to check 132 * whether call->prog_array is empty or not, which is 133 * a heuristic to speed up execution. 134 * 135 * If bpf_prog_array_valid() fetched prog_array was 136 * non-NULL, we go into trace_call_bpf() and do the actual 137 * proper rcu_dereference() under RCU lock. 138 * If it turns out that prog_array is NULL then, we bail out. 139 * For the opposite, if the bpf_prog_array_valid() fetched pointer 140 * was NULL, you'll skip the prog_array with the risk of missing 141 * out of events when it was updated in between this and the 142 * rcu_dereference() which is accepted risk. 143 */ 144 rcu_read_lock(); 145 ret = bpf_prog_run_array(rcu_dereference(call->prog_array), 146 ctx, bpf_prog_run); 147 rcu_read_unlock(); 148 149 out: 150 __this_cpu_dec(bpf_prog_active); 151 152 return ret; 153 } 154 155 #ifdef CONFIG_BPF_KPROBE_OVERRIDE 156 BPF_CALL_2(bpf_override_return, struct pt_regs *, regs, unsigned long, rc) 157 { 158 regs_set_return_value(regs, rc); 159 override_function_with_return(regs); 160 return 0; 161 } 162 163 static const struct bpf_func_proto bpf_override_return_proto = { 164 .func = bpf_override_return, 165 .gpl_only = true, 166 .ret_type = RET_INTEGER, 167 .arg1_type = ARG_PTR_TO_CTX, 168 .arg2_type = ARG_ANYTHING, 169 }; 170 #endif 171 172 static __always_inline int 173 bpf_probe_read_user_common(void *dst, u32 size, const void __user *unsafe_ptr) 174 { 175 int ret; 176 177 ret = copy_from_user_nofault(dst, unsafe_ptr, size); 178 if (unlikely(ret < 0)) 179 memset(dst, 0, size); 180 return ret; 181 } 182 183 BPF_CALL_3(bpf_probe_read_user, void *, dst, u32, size, 184 const void __user *, unsafe_ptr) 185 { 186 return bpf_probe_read_user_common(dst, size, unsafe_ptr); 187 } 188 189 const struct bpf_func_proto bpf_probe_read_user_proto = { 190 .func = bpf_probe_read_user, 191 .gpl_only = true, 192 .ret_type = RET_INTEGER, 193 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 194 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 195 .arg3_type = ARG_ANYTHING, 196 }; 197 198 static __always_inline int 199 bpf_probe_read_user_str_common(void *dst, u32 size, 200 const void __user *unsafe_ptr) 201 { 202 int ret; 203 204 /* 205 * NB: We rely on strncpy_from_user() not copying junk past the NUL 206 * terminator into `dst`. 207 * 208 * strncpy_from_user() does long-sized strides in the fast path. If the 209 * strncpy does not mask out the bytes after the NUL in `unsafe_ptr`, 210 * then there could be junk after the NUL in `dst`. If user takes `dst` 211 * and keys a hash map with it, then semantically identical strings can 212 * occupy multiple entries in the map. 213 */ 214 ret = strncpy_from_user_nofault(dst, unsafe_ptr, size); 215 if (unlikely(ret < 0)) 216 memset(dst, 0, size); 217 return ret; 218 } 219 220 BPF_CALL_3(bpf_probe_read_user_str, void *, dst, u32, size, 221 const void __user *, unsafe_ptr) 222 { 223 return bpf_probe_read_user_str_common(dst, size, unsafe_ptr); 224 } 225 226 const struct bpf_func_proto bpf_probe_read_user_str_proto = { 227 .func = bpf_probe_read_user_str, 228 .gpl_only = true, 229 .ret_type = RET_INTEGER, 230 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 231 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 232 .arg3_type = ARG_ANYTHING, 233 }; 234 235 BPF_CALL_3(bpf_probe_read_kernel, void *, dst, u32, size, 236 const void *, unsafe_ptr) 237 { 238 return bpf_probe_read_kernel_common(dst, size, unsafe_ptr); 239 } 240 241 const struct bpf_func_proto bpf_probe_read_kernel_proto = { 242 .func = bpf_probe_read_kernel, 243 .gpl_only = true, 244 .ret_type = RET_INTEGER, 245 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 246 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 247 .arg3_type = ARG_ANYTHING, 248 }; 249 250 static __always_inline int 251 bpf_probe_read_kernel_str_common(void *dst, u32 size, const void *unsafe_ptr) 252 { 253 int ret; 254 255 /* 256 * The strncpy_from_kernel_nofault() call will likely not fill the 257 * entire buffer, but that's okay in this circumstance as we're probing 258 * arbitrary memory anyway similar to bpf_probe_read_*() and might 259 * as well probe the stack. Thus, memory is explicitly cleared 260 * only in error case, so that improper users ignoring return 261 * code altogether don't copy garbage; otherwise length of string 262 * is returned that can be used for bpf_perf_event_output() et al. 263 */ 264 ret = strncpy_from_kernel_nofault(dst, unsafe_ptr, size); 265 if (unlikely(ret < 0)) 266 memset(dst, 0, size); 267 return ret; 268 } 269 270 BPF_CALL_3(bpf_probe_read_kernel_str, void *, dst, u32, size, 271 const void *, unsafe_ptr) 272 { 273 return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr); 274 } 275 276 const struct bpf_func_proto bpf_probe_read_kernel_str_proto = { 277 .func = bpf_probe_read_kernel_str, 278 .gpl_only = true, 279 .ret_type = RET_INTEGER, 280 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 281 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 282 .arg3_type = ARG_ANYTHING, 283 }; 284 285 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 286 BPF_CALL_3(bpf_probe_read_compat, void *, dst, u32, size, 287 const void *, unsafe_ptr) 288 { 289 if ((unsigned long)unsafe_ptr < TASK_SIZE) { 290 return bpf_probe_read_user_common(dst, size, 291 (__force void __user *)unsafe_ptr); 292 } 293 return bpf_probe_read_kernel_common(dst, size, unsafe_ptr); 294 } 295 296 static const struct bpf_func_proto bpf_probe_read_compat_proto = { 297 .func = bpf_probe_read_compat, 298 .gpl_only = true, 299 .ret_type = RET_INTEGER, 300 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 301 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 302 .arg3_type = ARG_ANYTHING, 303 }; 304 305 BPF_CALL_3(bpf_probe_read_compat_str, void *, dst, u32, size, 306 const void *, unsafe_ptr) 307 { 308 if ((unsigned long)unsafe_ptr < TASK_SIZE) { 309 return bpf_probe_read_user_str_common(dst, size, 310 (__force void __user *)unsafe_ptr); 311 } 312 return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr); 313 } 314 315 static const struct bpf_func_proto bpf_probe_read_compat_str_proto = { 316 .func = bpf_probe_read_compat_str, 317 .gpl_only = true, 318 .ret_type = RET_INTEGER, 319 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 320 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 321 .arg3_type = ARG_ANYTHING, 322 }; 323 #endif /* CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE */ 324 325 BPF_CALL_3(bpf_probe_write_user, void __user *, unsafe_ptr, const void *, src, 326 u32, size) 327 { 328 /* 329 * Ensure we're in user context which is safe for the helper to 330 * run. This helper has no business in a kthread. 331 * 332 * access_ok() should prevent writing to non-user memory, but in 333 * some situations (nommu, temporary switch, etc) access_ok() does 334 * not provide enough validation, hence the check on KERNEL_DS. 335 * 336 * nmi_uaccess_okay() ensures the probe is not run in an interim 337 * state, when the task or mm are switched. This is specifically 338 * required to prevent the use of temporary mm. 339 */ 340 341 if (unlikely(in_interrupt() || 342 current->flags & (PF_KTHREAD | PF_EXITING))) 343 return -EPERM; 344 if (unlikely(!nmi_uaccess_okay())) 345 return -EPERM; 346 347 return copy_to_user_nofault(unsafe_ptr, src, size); 348 } 349 350 static const struct bpf_func_proto bpf_probe_write_user_proto = { 351 .func = bpf_probe_write_user, 352 .gpl_only = true, 353 .ret_type = RET_INTEGER, 354 .arg1_type = ARG_ANYTHING, 355 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 356 .arg3_type = ARG_CONST_SIZE, 357 }; 358 359 #define MAX_TRACE_PRINTK_VARARGS 3 360 #define BPF_TRACE_PRINTK_SIZE 1024 361 362 BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1, 363 u64, arg2, u64, arg3) 364 { 365 u64 args[MAX_TRACE_PRINTK_VARARGS] = { arg1, arg2, arg3 }; 366 struct bpf_bprintf_data data = { 367 .get_bin_args = true, 368 .get_buf = true, 369 }; 370 int ret; 371 372 ret = bpf_bprintf_prepare(fmt, fmt_size, args, 373 MAX_TRACE_PRINTK_VARARGS, &data); 374 if (ret < 0) 375 return ret; 376 377 ret = bstr_printf(data.buf, MAX_BPRINTF_BUF, fmt, data.bin_args); 378 379 trace_bpf_trace_printk(data.buf); 380 381 bpf_bprintf_cleanup(&data); 382 383 return ret; 384 } 385 386 static const struct bpf_func_proto bpf_trace_printk_proto = { 387 .func = bpf_trace_printk, 388 .gpl_only = true, 389 .ret_type = RET_INTEGER, 390 .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY, 391 .arg2_type = ARG_CONST_SIZE, 392 }; 393 394 static void __set_printk_clr_event(struct work_struct *work) 395 { 396 /* 397 * This program might be calling bpf_trace_printk, 398 * so enable the associated bpf_trace/bpf_trace_printk event. 399 * Repeat this each time as it is possible a user has 400 * disabled bpf_trace_printk events. By loading a program 401 * calling bpf_trace_printk() however the user has expressed 402 * the intent to see such events. 403 */ 404 if (trace_set_clr_event("bpf_trace", "bpf_trace_printk", 1)) 405 pr_warn_ratelimited("could not enable bpf_trace_printk events"); 406 } 407 static DECLARE_WORK(set_printk_work, __set_printk_clr_event); 408 409 const struct bpf_func_proto *bpf_get_trace_printk_proto(void) 410 { 411 schedule_work(&set_printk_work); 412 return &bpf_trace_printk_proto; 413 } 414 415 BPF_CALL_4(bpf_trace_vprintk, char *, fmt, u32, fmt_size, const void *, args, 416 u32, data_len) 417 { 418 struct bpf_bprintf_data data = { 419 .get_bin_args = true, 420 .get_buf = true, 421 }; 422 int ret, num_args; 423 424 if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 || 425 (data_len && !args)) 426 return -EINVAL; 427 num_args = data_len / 8; 428 429 ret = bpf_bprintf_prepare(fmt, fmt_size, args, num_args, &data); 430 if (ret < 0) 431 return ret; 432 433 ret = bstr_printf(data.buf, MAX_BPRINTF_BUF, fmt, data.bin_args); 434 435 trace_bpf_trace_printk(data.buf); 436 437 bpf_bprintf_cleanup(&data); 438 439 return ret; 440 } 441 442 static const struct bpf_func_proto bpf_trace_vprintk_proto = { 443 .func = bpf_trace_vprintk, 444 .gpl_only = true, 445 .ret_type = RET_INTEGER, 446 .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY, 447 .arg2_type = ARG_CONST_SIZE, 448 .arg3_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY, 449 .arg4_type = ARG_CONST_SIZE_OR_ZERO, 450 }; 451 452 const struct bpf_func_proto *bpf_get_trace_vprintk_proto(void) 453 { 454 schedule_work(&set_printk_work); 455 return &bpf_trace_vprintk_proto; 456 } 457 458 BPF_CALL_5(bpf_seq_printf, struct seq_file *, m, char *, fmt, u32, fmt_size, 459 const void *, args, u32, data_len) 460 { 461 struct bpf_bprintf_data data = { 462 .get_bin_args = true, 463 }; 464 int err, num_args; 465 466 if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 || 467 (data_len && !args)) 468 return -EINVAL; 469 num_args = data_len / 8; 470 471 err = bpf_bprintf_prepare(fmt, fmt_size, args, num_args, &data); 472 if (err < 0) 473 return err; 474 475 seq_bprintf(m, fmt, data.bin_args); 476 477 bpf_bprintf_cleanup(&data); 478 479 return seq_has_overflowed(m) ? -EOVERFLOW : 0; 480 } 481 482 BTF_ID_LIST_SINGLE(btf_seq_file_ids, struct, seq_file) 483 484 static const struct bpf_func_proto bpf_seq_printf_proto = { 485 .func = bpf_seq_printf, 486 .gpl_only = true, 487 .ret_type = RET_INTEGER, 488 .arg1_type = ARG_PTR_TO_BTF_ID, 489 .arg1_btf_id = &btf_seq_file_ids[0], 490 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 491 .arg3_type = ARG_CONST_SIZE, 492 .arg4_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY, 493 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 494 }; 495 496 BPF_CALL_3(bpf_seq_write, struct seq_file *, m, const void *, data, u32, len) 497 { 498 return seq_write(m, data, len) ? -EOVERFLOW : 0; 499 } 500 501 static const struct bpf_func_proto bpf_seq_write_proto = { 502 .func = bpf_seq_write, 503 .gpl_only = true, 504 .ret_type = RET_INTEGER, 505 .arg1_type = ARG_PTR_TO_BTF_ID, 506 .arg1_btf_id = &btf_seq_file_ids[0], 507 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 508 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 509 }; 510 511 BPF_CALL_4(bpf_seq_printf_btf, struct seq_file *, m, struct btf_ptr *, ptr, 512 u32, btf_ptr_size, u64, flags) 513 { 514 const struct btf *btf; 515 s32 btf_id; 516 int ret; 517 518 ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id); 519 if (ret) 520 return ret; 521 522 return btf_type_seq_show_flags(btf, btf_id, ptr->ptr, m, flags); 523 } 524 525 static const struct bpf_func_proto bpf_seq_printf_btf_proto = { 526 .func = bpf_seq_printf_btf, 527 .gpl_only = true, 528 .ret_type = RET_INTEGER, 529 .arg1_type = ARG_PTR_TO_BTF_ID, 530 .arg1_btf_id = &btf_seq_file_ids[0], 531 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 532 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 533 .arg4_type = ARG_ANYTHING, 534 }; 535 536 static __always_inline int 537 get_map_perf_counter(struct bpf_map *map, u64 flags, 538 u64 *value, u64 *enabled, u64 *running) 539 { 540 struct bpf_array *array = container_of(map, struct bpf_array, map); 541 unsigned int cpu = smp_processor_id(); 542 u64 index = flags & BPF_F_INDEX_MASK; 543 struct bpf_event_entry *ee; 544 545 if (unlikely(flags & ~(BPF_F_INDEX_MASK))) 546 return -EINVAL; 547 if (index == BPF_F_CURRENT_CPU) 548 index = cpu; 549 if (unlikely(index >= array->map.max_entries)) 550 return -E2BIG; 551 552 ee = READ_ONCE(array->ptrs[index]); 553 if (!ee) 554 return -ENOENT; 555 556 return perf_event_read_local(ee->event, value, enabled, running); 557 } 558 559 BPF_CALL_2(bpf_perf_event_read, struct bpf_map *, map, u64, flags) 560 { 561 u64 value = 0; 562 int err; 563 564 err = get_map_perf_counter(map, flags, &value, NULL, NULL); 565 /* 566 * this api is ugly since we miss [-22..-2] range of valid 567 * counter values, but that's uapi 568 */ 569 if (err) 570 return err; 571 return value; 572 } 573 574 const struct bpf_func_proto bpf_perf_event_read_proto = { 575 .func = bpf_perf_event_read, 576 .gpl_only = true, 577 .ret_type = RET_INTEGER, 578 .arg1_type = ARG_CONST_MAP_PTR, 579 .arg2_type = ARG_ANYTHING, 580 }; 581 582 BPF_CALL_4(bpf_perf_event_read_value, struct bpf_map *, map, u64, flags, 583 struct bpf_perf_event_value *, buf, u32, size) 584 { 585 int err = -EINVAL; 586 587 if (unlikely(size != sizeof(struct bpf_perf_event_value))) 588 goto clear; 589 err = get_map_perf_counter(map, flags, &buf->counter, &buf->enabled, 590 &buf->running); 591 if (unlikely(err)) 592 goto clear; 593 return 0; 594 clear: 595 memset(buf, 0, size); 596 return err; 597 } 598 599 static const struct bpf_func_proto bpf_perf_event_read_value_proto = { 600 .func = bpf_perf_event_read_value, 601 .gpl_only = true, 602 .ret_type = RET_INTEGER, 603 .arg1_type = ARG_CONST_MAP_PTR, 604 .arg2_type = ARG_ANYTHING, 605 .arg3_type = ARG_PTR_TO_UNINIT_MEM, 606 .arg4_type = ARG_CONST_SIZE, 607 }; 608 609 const struct bpf_func_proto *bpf_get_perf_event_read_value_proto(void) 610 { 611 return &bpf_perf_event_read_value_proto; 612 } 613 614 static __always_inline u64 615 __bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map, 616 u64 flags, struct perf_raw_record *raw, 617 struct perf_sample_data *sd) 618 { 619 struct bpf_array *array = container_of(map, struct bpf_array, map); 620 unsigned int cpu = smp_processor_id(); 621 u64 index = flags & BPF_F_INDEX_MASK; 622 struct bpf_event_entry *ee; 623 struct perf_event *event; 624 625 if (index == BPF_F_CURRENT_CPU) 626 index = cpu; 627 if (unlikely(index >= array->map.max_entries)) 628 return -E2BIG; 629 630 ee = READ_ONCE(array->ptrs[index]); 631 if (!ee) 632 return -ENOENT; 633 634 event = ee->event; 635 if (unlikely(event->attr.type != PERF_TYPE_SOFTWARE || 636 event->attr.config != PERF_COUNT_SW_BPF_OUTPUT)) 637 return -EINVAL; 638 639 if (unlikely(event->oncpu != cpu)) 640 return -EOPNOTSUPP; 641 642 perf_sample_save_raw_data(sd, event, raw); 643 644 return perf_event_output(event, sd, regs); 645 } 646 647 /* 648 * Support executing tracepoints in normal, irq, and nmi context that each call 649 * bpf_perf_event_output 650 */ 651 struct bpf_trace_sample_data { 652 struct perf_sample_data sds[3]; 653 }; 654 655 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_trace_sds); 656 static DEFINE_PER_CPU(int, bpf_trace_nest_level); 657 BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map, 658 u64, flags, void *, data, u64, size) 659 { 660 struct bpf_trace_sample_data *sds; 661 struct perf_raw_record raw = { 662 .frag = { 663 .size = size, 664 .data = data, 665 }, 666 }; 667 struct perf_sample_data *sd; 668 int nest_level, err; 669 670 preempt_disable(); 671 sds = this_cpu_ptr(&bpf_trace_sds); 672 nest_level = this_cpu_inc_return(bpf_trace_nest_level); 673 674 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(sds->sds))) { 675 err = -EBUSY; 676 goto out; 677 } 678 679 sd = &sds->sds[nest_level - 1]; 680 681 if (unlikely(flags & ~(BPF_F_INDEX_MASK))) { 682 err = -EINVAL; 683 goto out; 684 } 685 686 perf_sample_data_init(sd, 0, 0); 687 688 err = __bpf_perf_event_output(regs, map, flags, &raw, sd); 689 out: 690 this_cpu_dec(bpf_trace_nest_level); 691 preempt_enable(); 692 return err; 693 } 694 695 static const struct bpf_func_proto bpf_perf_event_output_proto = { 696 .func = bpf_perf_event_output, 697 .gpl_only = true, 698 .ret_type = RET_INTEGER, 699 .arg1_type = ARG_PTR_TO_CTX, 700 .arg2_type = ARG_CONST_MAP_PTR, 701 .arg3_type = ARG_ANYTHING, 702 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, 703 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 704 }; 705 706 static DEFINE_PER_CPU(int, bpf_event_output_nest_level); 707 struct bpf_nested_pt_regs { 708 struct pt_regs regs[3]; 709 }; 710 static DEFINE_PER_CPU(struct bpf_nested_pt_regs, bpf_pt_regs); 711 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_misc_sds); 712 713 u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size, 714 void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy) 715 { 716 struct perf_raw_frag frag = { 717 .copy = ctx_copy, 718 .size = ctx_size, 719 .data = ctx, 720 }; 721 struct perf_raw_record raw = { 722 .frag = { 723 { 724 .next = ctx_size ? &frag : NULL, 725 }, 726 .size = meta_size, 727 .data = meta, 728 }, 729 }; 730 struct perf_sample_data *sd; 731 struct pt_regs *regs; 732 int nest_level; 733 u64 ret; 734 735 preempt_disable(); 736 nest_level = this_cpu_inc_return(bpf_event_output_nest_level); 737 738 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(bpf_misc_sds.sds))) { 739 ret = -EBUSY; 740 goto out; 741 } 742 sd = this_cpu_ptr(&bpf_misc_sds.sds[nest_level - 1]); 743 regs = this_cpu_ptr(&bpf_pt_regs.regs[nest_level - 1]); 744 745 perf_fetch_caller_regs(regs); 746 perf_sample_data_init(sd, 0, 0); 747 748 ret = __bpf_perf_event_output(regs, map, flags, &raw, sd); 749 out: 750 this_cpu_dec(bpf_event_output_nest_level); 751 preempt_enable(); 752 return ret; 753 } 754 755 BPF_CALL_0(bpf_get_current_task) 756 { 757 return (long) current; 758 } 759 760 const struct bpf_func_proto bpf_get_current_task_proto = { 761 .func = bpf_get_current_task, 762 .gpl_only = true, 763 .ret_type = RET_INTEGER, 764 }; 765 766 BPF_CALL_0(bpf_get_current_task_btf) 767 { 768 return (unsigned long) current; 769 } 770 771 const struct bpf_func_proto bpf_get_current_task_btf_proto = { 772 .func = bpf_get_current_task_btf, 773 .gpl_only = true, 774 .ret_type = RET_PTR_TO_BTF_ID_TRUSTED, 775 .ret_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK], 776 }; 777 778 BPF_CALL_1(bpf_task_pt_regs, struct task_struct *, task) 779 { 780 return (unsigned long) task_pt_regs(task); 781 } 782 783 BTF_ID_LIST_SINGLE(bpf_task_pt_regs_ids, struct, pt_regs) 784 785 const struct bpf_func_proto bpf_task_pt_regs_proto = { 786 .func = bpf_task_pt_regs, 787 .gpl_only = true, 788 .arg1_type = ARG_PTR_TO_BTF_ID, 789 .arg1_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK], 790 .ret_type = RET_PTR_TO_BTF_ID, 791 .ret_btf_id = &bpf_task_pt_regs_ids[0], 792 }; 793 794 struct send_signal_irq_work { 795 struct irq_work irq_work; 796 struct task_struct *task; 797 u32 sig; 798 enum pid_type type; 799 bool has_siginfo; 800 struct kernel_siginfo info; 801 }; 802 803 static DEFINE_PER_CPU(struct send_signal_irq_work, send_signal_work); 804 805 static void do_bpf_send_signal(struct irq_work *entry) 806 { 807 struct send_signal_irq_work *work; 808 struct kernel_siginfo *siginfo; 809 810 work = container_of(entry, struct send_signal_irq_work, irq_work); 811 siginfo = work->has_siginfo ? &work->info : SEND_SIG_PRIV; 812 813 group_send_sig_info(work->sig, siginfo, work->task, work->type); 814 put_task_struct(work->task); 815 } 816 817 static int bpf_send_signal_common(u32 sig, enum pid_type type, struct task_struct *task, u64 value) 818 { 819 struct send_signal_irq_work *work = NULL; 820 struct kernel_siginfo info; 821 struct kernel_siginfo *siginfo; 822 823 if (!task) { 824 task = current; 825 siginfo = SEND_SIG_PRIV; 826 } else { 827 clear_siginfo(&info); 828 info.si_signo = sig; 829 info.si_errno = 0; 830 info.si_code = SI_KERNEL; 831 info.si_pid = 0; 832 info.si_uid = 0; 833 info.si_value.sival_ptr = (void *)(unsigned long)value; 834 siginfo = &info; 835 } 836 837 /* Similar to bpf_probe_write_user, task needs to be 838 * in a sound condition and kernel memory access be 839 * permitted in order to send signal to the current 840 * task. 841 */ 842 if (unlikely(task->flags & (PF_KTHREAD | PF_EXITING))) 843 return -EPERM; 844 if (unlikely(!nmi_uaccess_okay())) 845 return -EPERM; 846 /* Task should not be pid=1 to avoid kernel panic. */ 847 if (unlikely(is_global_init(task))) 848 return -EPERM; 849 850 if (preempt_count() != 0 || irqs_disabled()) { 851 /* Do an early check on signal validity. Otherwise, 852 * the error is lost in deferred irq_work. 853 */ 854 if (unlikely(!valid_signal(sig))) 855 return -EINVAL; 856 857 work = this_cpu_ptr(&send_signal_work); 858 if (irq_work_is_busy(&work->irq_work)) 859 return -EBUSY; 860 861 /* Add the current task, which is the target of sending signal, 862 * to the irq_work. The current task may change when queued 863 * irq works get executed. 864 */ 865 work->task = get_task_struct(task); 866 work->has_siginfo = siginfo == &info; 867 if (work->has_siginfo) 868 copy_siginfo(&work->info, &info); 869 work->sig = sig; 870 work->type = type; 871 irq_work_queue(&work->irq_work); 872 return 0; 873 } 874 875 return group_send_sig_info(sig, siginfo, task, type); 876 } 877 878 BPF_CALL_1(bpf_send_signal, u32, sig) 879 { 880 return bpf_send_signal_common(sig, PIDTYPE_TGID, NULL, 0); 881 } 882 883 const struct bpf_func_proto bpf_send_signal_proto = { 884 .func = bpf_send_signal, 885 .gpl_only = false, 886 .ret_type = RET_INTEGER, 887 .arg1_type = ARG_ANYTHING, 888 }; 889 890 BPF_CALL_1(bpf_send_signal_thread, u32, sig) 891 { 892 return bpf_send_signal_common(sig, PIDTYPE_PID, NULL, 0); 893 } 894 895 const struct bpf_func_proto bpf_send_signal_thread_proto = { 896 .func = bpf_send_signal_thread, 897 .gpl_only = false, 898 .ret_type = RET_INTEGER, 899 .arg1_type = ARG_ANYTHING, 900 }; 901 902 BPF_CALL_3(bpf_d_path, struct path *, path, char *, buf, u32, sz) 903 { 904 struct path copy; 905 long len; 906 char *p; 907 908 if (!sz) 909 return 0; 910 911 /* 912 * The path pointer is verified as trusted and safe to use, 913 * but let's double check it's valid anyway to workaround 914 * potentially broken verifier. 915 */ 916 len = copy_from_kernel_nofault(©, path, sizeof(*path)); 917 if (len < 0) 918 return len; 919 920 p = d_path(©, buf, sz); 921 if (IS_ERR(p)) { 922 len = PTR_ERR(p); 923 } else { 924 len = buf + sz - p; 925 memmove(buf, p, len); 926 } 927 928 return len; 929 } 930 931 BTF_SET_START(btf_allowlist_d_path) 932 #ifdef CONFIG_SECURITY 933 BTF_ID(func, security_file_permission) 934 BTF_ID(func, security_inode_getattr) 935 BTF_ID(func, security_file_open) 936 #endif 937 #ifdef CONFIG_SECURITY_PATH 938 BTF_ID(func, security_path_truncate) 939 #endif 940 BTF_ID(func, vfs_truncate) 941 BTF_ID(func, vfs_fallocate) 942 BTF_ID(func, dentry_open) 943 BTF_ID(func, vfs_getattr) 944 BTF_ID(func, filp_close) 945 BTF_SET_END(btf_allowlist_d_path) 946 947 static bool bpf_d_path_allowed(const struct bpf_prog *prog) 948 { 949 if (prog->type == BPF_PROG_TYPE_TRACING && 950 prog->expected_attach_type == BPF_TRACE_ITER) 951 return true; 952 953 if (prog->type == BPF_PROG_TYPE_LSM) 954 return bpf_lsm_is_sleepable_hook(prog->aux->attach_btf_id); 955 956 return btf_id_set_contains(&btf_allowlist_d_path, 957 prog->aux->attach_btf_id); 958 } 959 960 BTF_ID_LIST_SINGLE(bpf_d_path_btf_ids, struct, path) 961 962 static const struct bpf_func_proto bpf_d_path_proto = { 963 .func = bpf_d_path, 964 .gpl_only = false, 965 .ret_type = RET_INTEGER, 966 .arg1_type = ARG_PTR_TO_BTF_ID, 967 .arg1_btf_id = &bpf_d_path_btf_ids[0], 968 .arg2_type = ARG_PTR_TO_MEM, 969 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 970 .allowed = bpf_d_path_allowed, 971 }; 972 973 #define BTF_F_ALL (BTF_F_COMPACT | BTF_F_NONAME | \ 974 BTF_F_PTR_RAW | BTF_F_ZERO) 975 976 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size, 977 u64 flags, const struct btf **btf, 978 s32 *btf_id) 979 { 980 const struct btf_type *t; 981 982 if (unlikely(flags & ~(BTF_F_ALL))) 983 return -EINVAL; 984 985 if (btf_ptr_size != sizeof(struct btf_ptr)) 986 return -EINVAL; 987 988 *btf = bpf_get_btf_vmlinux(); 989 990 if (IS_ERR_OR_NULL(*btf)) 991 return IS_ERR(*btf) ? PTR_ERR(*btf) : -EINVAL; 992 993 if (ptr->type_id > 0) 994 *btf_id = ptr->type_id; 995 else 996 return -EINVAL; 997 998 if (*btf_id > 0) 999 t = btf_type_by_id(*btf, *btf_id); 1000 if (*btf_id <= 0 || !t) 1001 return -ENOENT; 1002 1003 return 0; 1004 } 1005 1006 BPF_CALL_5(bpf_snprintf_btf, char *, str, u32, str_size, struct btf_ptr *, ptr, 1007 u32, btf_ptr_size, u64, flags) 1008 { 1009 const struct btf *btf; 1010 s32 btf_id; 1011 int ret; 1012 1013 ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id); 1014 if (ret) 1015 return ret; 1016 1017 return btf_type_snprintf_show(btf, btf_id, ptr->ptr, str, str_size, 1018 flags); 1019 } 1020 1021 const struct bpf_func_proto bpf_snprintf_btf_proto = { 1022 .func = bpf_snprintf_btf, 1023 .gpl_only = false, 1024 .ret_type = RET_INTEGER, 1025 .arg1_type = ARG_PTR_TO_MEM, 1026 .arg2_type = ARG_CONST_SIZE, 1027 .arg3_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1028 .arg4_type = ARG_CONST_SIZE, 1029 .arg5_type = ARG_ANYTHING, 1030 }; 1031 1032 BPF_CALL_1(bpf_get_func_ip_tracing, void *, ctx) 1033 { 1034 /* This helper call is inlined by verifier. */ 1035 return ((u64 *)ctx)[-2]; 1036 } 1037 1038 static const struct bpf_func_proto bpf_get_func_ip_proto_tracing = { 1039 .func = bpf_get_func_ip_tracing, 1040 .gpl_only = true, 1041 .ret_type = RET_INTEGER, 1042 .arg1_type = ARG_PTR_TO_CTX, 1043 }; 1044 1045 static inline unsigned long get_entry_ip(unsigned long fentry_ip) 1046 { 1047 #ifdef CONFIG_X86_KERNEL_IBT 1048 if (is_endbr((void *)(fentry_ip - ENDBR_INSN_SIZE))) 1049 fentry_ip -= ENDBR_INSN_SIZE; 1050 #endif 1051 return fentry_ip; 1052 } 1053 1054 BPF_CALL_1(bpf_get_func_ip_kprobe, struct pt_regs *, regs) 1055 { 1056 struct bpf_trace_run_ctx *run_ctx __maybe_unused; 1057 struct kprobe *kp; 1058 1059 #ifdef CONFIG_UPROBES 1060 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); 1061 if (run_ctx->is_uprobe) 1062 return ((struct uprobe_dispatch_data *)current->utask->vaddr)->bp_addr; 1063 #endif 1064 1065 kp = kprobe_running(); 1066 1067 if (!kp || !(kp->flags & KPROBE_FLAG_ON_FUNC_ENTRY)) 1068 return 0; 1069 1070 return get_entry_ip((uintptr_t)kp->addr); 1071 } 1072 1073 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe = { 1074 .func = bpf_get_func_ip_kprobe, 1075 .gpl_only = true, 1076 .ret_type = RET_INTEGER, 1077 .arg1_type = ARG_PTR_TO_CTX, 1078 }; 1079 1080 BPF_CALL_1(bpf_get_func_ip_kprobe_multi, struct pt_regs *, regs) 1081 { 1082 return bpf_kprobe_multi_entry_ip(current->bpf_ctx); 1083 } 1084 1085 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe_multi = { 1086 .func = bpf_get_func_ip_kprobe_multi, 1087 .gpl_only = false, 1088 .ret_type = RET_INTEGER, 1089 .arg1_type = ARG_PTR_TO_CTX, 1090 }; 1091 1092 BPF_CALL_1(bpf_get_attach_cookie_kprobe_multi, struct pt_regs *, regs) 1093 { 1094 return bpf_kprobe_multi_cookie(current->bpf_ctx); 1095 } 1096 1097 static const struct bpf_func_proto bpf_get_attach_cookie_proto_kmulti = { 1098 .func = bpf_get_attach_cookie_kprobe_multi, 1099 .gpl_only = false, 1100 .ret_type = RET_INTEGER, 1101 .arg1_type = ARG_PTR_TO_CTX, 1102 }; 1103 1104 BPF_CALL_1(bpf_get_func_ip_uprobe_multi, struct pt_regs *, regs) 1105 { 1106 return bpf_uprobe_multi_entry_ip(current->bpf_ctx); 1107 } 1108 1109 static const struct bpf_func_proto bpf_get_func_ip_proto_uprobe_multi = { 1110 .func = bpf_get_func_ip_uprobe_multi, 1111 .gpl_only = false, 1112 .ret_type = RET_INTEGER, 1113 .arg1_type = ARG_PTR_TO_CTX, 1114 }; 1115 1116 BPF_CALL_1(bpf_get_attach_cookie_uprobe_multi, struct pt_regs *, regs) 1117 { 1118 return bpf_uprobe_multi_cookie(current->bpf_ctx); 1119 } 1120 1121 static const struct bpf_func_proto bpf_get_attach_cookie_proto_umulti = { 1122 .func = bpf_get_attach_cookie_uprobe_multi, 1123 .gpl_only = false, 1124 .ret_type = RET_INTEGER, 1125 .arg1_type = ARG_PTR_TO_CTX, 1126 }; 1127 1128 BPF_CALL_1(bpf_get_attach_cookie_trace, void *, ctx) 1129 { 1130 struct bpf_trace_run_ctx *run_ctx; 1131 1132 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); 1133 return run_ctx->bpf_cookie; 1134 } 1135 1136 static const struct bpf_func_proto bpf_get_attach_cookie_proto_trace = { 1137 .func = bpf_get_attach_cookie_trace, 1138 .gpl_only = false, 1139 .ret_type = RET_INTEGER, 1140 .arg1_type = ARG_PTR_TO_CTX, 1141 }; 1142 1143 BPF_CALL_1(bpf_get_attach_cookie_pe, struct bpf_perf_event_data_kern *, ctx) 1144 { 1145 return ctx->event->bpf_cookie; 1146 } 1147 1148 static const struct bpf_func_proto bpf_get_attach_cookie_proto_pe = { 1149 .func = bpf_get_attach_cookie_pe, 1150 .gpl_only = false, 1151 .ret_type = RET_INTEGER, 1152 .arg1_type = ARG_PTR_TO_CTX, 1153 }; 1154 1155 BPF_CALL_1(bpf_get_attach_cookie_tracing, void *, ctx) 1156 { 1157 struct bpf_trace_run_ctx *run_ctx; 1158 1159 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); 1160 return run_ctx->bpf_cookie; 1161 } 1162 1163 static const struct bpf_func_proto bpf_get_attach_cookie_proto_tracing = { 1164 .func = bpf_get_attach_cookie_tracing, 1165 .gpl_only = false, 1166 .ret_type = RET_INTEGER, 1167 .arg1_type = ARG_PTR_TO_CTX, 1168 }; 1169 1170 BPF_CALL_3(bpf_get_branch_snapshot, void *, buf, u32, size, u64, flags) 1171 { 1172 static const u32 br_entry_size = sizeof(struct perf_branch_entry); 1173 u32 entry_cnt = size / br_entry_size; 1174 1175 entry_cnt = static_call(perf_snapshot_branch_stack)(buf, entry_cnt); 1176 1177 if (unlikely(flags)) 1178 return -EINVAL; 1179 1180 if (!entry_cnt) 1181 return -ENOENT; 1182 1183 return entry_cnt * br_entry_size; 1184 } 1185 1186 const struct bpf_func_proto bpf_get_branch_snapshot_proto = { 1187 .func = bpf_get_branch_snapshot, 1188 .gpl_only = true, 1189 .ret_type = RET_INTEGER, 1190 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 1191 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 1192 }; 1193 1194 BPF_CALL_3(get_func_arg, void *, ctx, u32, n, u64 *, value) 1195 { 1196 /* This helper call is inlined by verifier. */ 1197 u64 nr_args = ((u64 *)ctx)[-1]; 1198 1199 if ((u64) n >= nr_args) 1200 return -EINVAL; 1201 *value = ((u64 *)ctx)[n]; 1202 return 0; 1203 } 1204 1205 static const struct bpf_func_proto bpf_get_func_arg_proto = { 1206 .func = get_func_arg, 1207 .ret_type = RET_INTEGER, 1208 .arg1_type = ARG_PTR_TO_CTX, 1209 .arg2_type = ARG_ANYTHING, 1210 .arg3_type = ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED, 1211 .arg3_size = sizeof(u64), 1212 }; 1213 1214 BPF_CALL_2(get_func_ret, void *, ctx, u64 *, value) 1215 { 1216 /* This helper call is inlined by verifier. */ 1217 u64 nr_args = ((u64 *)ctx)[-1]; 1218 1219 *value = ((u64 *)ctx)[nr_args]; 1220 return 0; 1221 } 1222 1223 static const struct bpf_func_proto bpf_get_func_ret_proto = { 1224 .func = get_func_ret, 1225 .ret_type = RET_INTEGER, 1226 .arg1_type = ARG_PTR_TO_CTX, 1227 .arg2_type = ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED, 1228 .arg2_size = sizeof(u64), 1229 }; 1230 1231 BPF_CALL_1(get_func_arg_cnt, void *, ctx) 1232 { 1233 /* This helper call is inlined by verifier. */ 1234 return ((u64 *)ctx)[-1]; 1235 } 1236 1237 static const struct bpf_func_proto bpf_get_func_arg_cnt_proto = { 1238 .func = get_func_arg_cnt, 1239 .ret_type = RET_INTEGER, 1240 .arg1_type = ARG_PTR_TO_CTX, 1241 }; 1242 1243 static const struct bpf_func_proto * 1244 bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1245 { 1246 const struct bpf_func_proto *func_proto; 1247 1248 switch (func_id) { 1249 case BPF_FUNC_get_smp_processor_id: 1250 return &bpf_get_smp_processor_id_proto; 1251 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 1252 case BPF_FUNC_probe_read: 1253 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1254 NULL : &bpf_probe_read_compat_proto; 1255 case BPF_FUNC_probe_read_str: 1256 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1257 NULL : &bpf_probe_read_compat_str_proto; 1258 #endif 1259 case BPF_FUNC_get_func_ip: 1260 return &bpf_get_func_ip_proto_tracing; 1261 default: 1262 break; 1263 } 1264 1265 func_proto = bpf_base_func_proto(func_id, prog); 1266 if (func_proto) 1267 return func_proto; 1268 1269 if (!bpf_token_capable(prog->aux->token, CAP_SYS_ADMIN)) 1270 return NULL; 1271 1272 switch (func_id) { 1273 case BPF_FUNC_probe_write_user: 1274 return security_locked_down(LOCKDOWN_BPF_WRITE_USER) < 0 ? 1275 NULL : &bpf_probe_write_user_proto; 1276 default: 1277 return NULL; 1278 } 1279 } 1280 1281 static bool is_kprobe_multi(const struct bpf_prog *prog) 1282 { 1283 return prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI || 1284 prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION; 1285 } 1286 1287 static inline bool is_kprobe_session(const struct bpf_prog *prog) 1288 { 1289 return prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION; 1290 } 1291 1292 static inline bool is_uprobe_multi(const struct bpf_prog *prog) 1293 { 1294 return prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI || 1295 prog->expected_attach_type == BPF_TRACE_UPROBE_SESSION; 1296 } 1297 1298 static inline bool is_uprobe_session(const struct bpf_prog *prog) 1299 { 1300 return prog->expected_attach_type == BPF_TRACE_UPROBE_SESSION; 1301 } 1302 1303 static const struct bpf_func_proto * 1304 kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1305 { 1306 switch (func_id) { 1307 case BPF_FUNC_perf_event_output: 1308 return &bpf_perf_event_output_proto; 1309 case BPF_FUNC_get_stackid: 1310 return &bpf_get_stackid_proto; 1311 case BPF_FUNC_get_stack: 1312 return prog->sleepable ? &bpf_get_stack_sleepable_proto : &bpf_get_stack_proto; 1313 #ifdef CONFIG_BPF_KPROBE_OVERRIDE 1314 case BPF_FUNC_override_return: 1315 return &bpf_override_return_proto; 1316 #endif 1317 case BPF_FUNC_get_func_ip: 1318 if (is_kprobe_multi(prog)) 1319 return &bpf_get_func_ip_proto_kprobe_multi; 1320 if (is_uprobe_multi(prog)) 1321 return &bpf_get_func_ip_proto_uprobe_multi; 1322 return &bpf_get_func_ip_proto_kprobe; 1323 case BPF_FUNC_get_attach_cookie: 1324 if (is_kprobe_multi(prog)) 1325 return &bpf_get_attach_cookie_proto_kmulti; 1326 if (is_uprobe_multi(prog)) 1327 return &bpf_get_attach_cookie_proto_umulti; 1328 return &bpf_get_attach_cookie_proto_trace; 1329 default: 1330 return bpf_tracing_func_proto(func_id, prog); 1331 } 1332 } 1333 1334 /* bpf+kprobe programs can access fields of 'struct pt_regs' */ 1335 static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type, 1336 const struct bpf_prog *prog, 1337 struct bpf_insn_access_aux *info) 1338 { 1339 if (off < 0 || off >= sizeof(struct pt_regs)) 1340 return false; 1341 if (off % size != 0) 1342 return false; 1343 /* 1344 * Assertion for 32 bit to make sure last 8 byte access 1345 * (BPF_DW) to the last 4 byte member is disallowed. 1346 */ 1347 if (off + size > sizeof(struct pt_regs)) 1348 return false; 1349 1350 if (type == BPF_WRITE) 1351 prog->aux->kprobe_write_ctx = true; 1352 1353 return true; 1354 } 1355 1356 const struct bpf_verifier_ops kprobe_verifier_ops = { 1357 .get_func_proto = kprobe_prog_func_proto, 1358 .is_valid_access = kprobe_prog_is_valid_access, 1359 }; 1360 1361 const struct bpf_prog_ops kprobe_prog_ops = { 1362 }; 1363 1364 BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map, 1365 u64, flags, void *, data, u64, size) 1366 { 1367 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1368 1369 /* 1370 * r1 points to perf tracepoint buffer where first 8 bytes are hidden 1371 * from bpf program and contain a pointer to 'struct pt_regs'. Fetch it 1372 * from there and call the same bpf_perf_event_output() helper inline. 1373 */ 1374 return ____bpf_perf_event_output(regs, map, flags, data, size); 1375 } 1376 1377 static const struct bpf_func_proto bpf_perf_event_output_proto_tp = { 1378 .func = bpf_perf_event_output_tp, 1379 .gpl_only = true, 1380 .ret_type = RET_INTEGER, 1381 .arg1_type = ARG_PTR_TO_CTX, 1382 .arg2_type = ARG_CONST_MAP_PTR, 1383 .arg3_type = ARG_ANYTHING, 1384 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1385 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 1386 }; 1387 1388 BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map, 1389 u64, flags) 1390 { 1391 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1392 1393 /* 1394 * Same comment as in bpf_perf_event_output_tp(), only that this time 1395 * the other helper's function body cannot be inlined due to being 1396 * external, thus we need to call raw helper function. 1397 */ 1398 return bpf_get_stackid((unsigned long) regs, (unsigned long) map, 1399 flags, 0, 0); 1400 } 1401 1402 static const struct bpf_func_proto bpf_get_stackid_proto_tp = { 1403 .func = bpf_get_stackid_tp, 1404 .gpl_only = true, 1405 .ret_type = RET_INTEGER, 1406 .arg1_type = ARG_PTR_TO_CTX, 1407 .arg2_type = ARG_CONST_MAP_PTR, 1408 .arg3_type = ARG_ANYTHING, 1409 }; 1410 1411 BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size, 1412 u64, flags) 1413 { 1414 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1415 1416 return bpf_get_stack((unsigned long) regs, (unsigned long) buf, 1417 (unsigned long) size, flags, 0); 1418 } 1419 1420 static const struct bpf_func_proto bpf_get_stack_proto_tp = { 1421 .func = bpf_get_stack_tp, 1422 .gpl_only = true, 1423 .ret_type = RET_INTEGER, 1424 .arg1_type = ARG_PTR_TO_CTX, 1425 .arg2_type = ARG_PTR_TO_UNINIT_MEM, 1426 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1427 .arg4_type = ARG_ANYTHING, 1428 }; 1429 1430 static const struct bpf_func_proto * 1431 tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1432 { 1433 switch (func_id) { 1434 case BPF_FUNC_perf_event_output: 1435 return &bpf_perf_event_output_proto_tp; 1436 case BPF_FUNC_get_stackid: 1437 return &bpf_get_stackid_proto_tp; 1438 case BPF_FUNC_get_stack: 1439 return &bpf_get_stack_proto_tp; 1440 case BPF_FUNC_get_attach_cookie: 1441 return &bpf_get_attach_cookie_proto_trace; 1442 default: 1443 return bpf_tracing_func_proto(func_id, prog); 1444 } 1445 } 1446 1447 static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type, 1448 const struct bpf_prog *prog, 1449 struct bpf_insn_access_aux *info) 1450 { 1451 if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE) 1452 return false; 1453 if (type != BPF_READ) 1454 return false; 1455 if (off % size != 0) 1456 return false; 1457 1458 BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(__u64)); 1459 return true; 1460 } 1461 1462 const struct bpf_verifier_ops tracepoint_verifier_ops = { 1463 .get_func_proto = tp_prog_func_proto, 1464 .is_valid_access = tp_prog_is_valid_access, 1465 }; 1466 1467 const struct bpf_prog_ops tracepoint_prog_ops = { 1468 }; 1469 1470 BPF_CALL_3(bpf_perf_prog_read_value, struct bpf_perf_event_data_kern *, ctx, 1471 struct bpf_perf_event_value *, buf, u32, size) 1472 { 1473 int err = -EINVAL; 1474 1475 if (unlikely(size != sizeof(struct bpf_perf_event_value))) 1476 goto clear; 1477 err = perf_event_read_local(ctx->event, &buf->counter, &buf->enabled, 1478 &buf->running); 1479 if (unlikely(err)) 1480 goto clear; 1481 return 0; 1482 clear: 1483 memset(buf, 0, size); 1484 return err; 1485 } 1486 1487 static const struct bpf_func_proto bpf_perf_prog_read_value_proto = { 1488 .func = bpf_perf_prog_read_value, 1489 .gpl_only = true, 1490 .ret_type = RET_INTEGER, 1491 .arg1_type = ARG_PTR_TO_CTX, 1492 .arg2_type = ARG_PTR_TO_UNINIT_MEM, 1493 .arg3_type = ARG_CONST_SIZE, 1494 }; 1495 1496 BPF_CALL_4(bpf_read_branch_records, struct bpf_perf_event_data_kern *, ctx, 1497 void *, buf, u32, size, u64, flags) 1498 { 1499 static const u32 br_entry_size = sizeof(struct perf_branch_entry); 1500 struct perf_branch_stack *br_stack = ctx->data->br_stack; 1501 u32 to_copy; 1502 1503 if (unlikely(flags & ~BPF_F_GET_BRANCH_RECORDS_SIZE)) 1504 return -EINVAL; 1505 1506 if (unlikely(!(ctx->data->sample_flags & PERF_SAMPLE_BRANCH_STACK))) 1507 return -ENOENT; 1508 1509 if (unlikely(!br_stack)) 1510 return -ENOENT; 1511 1512 if (flags & BPF_F_GET_BRANCH_RECORDS_SIZE) 1513 return br_stack->nr * br_entry_size; 1514 1515 if (!buf || (size % br_entry_size != 0)) 1516 return -EINVAL; 1517 1518 to_copy = min_t(u32, br_stack->nr * br_entry_size, size); 1519 memcpy(buf, br_stack->entries, to_copy); 1520 1521 return to_copy; 1522 } 1523 1524 static const struct bpf_func_proto bpf_read_branch_records_proto = { 1525 .func = bpf_read_branch_records, 1526 .gpl_only = true, 1527 .ret_type = RET_INTEGER, 1528 .arg1_type = ARG_PTR_TO_CTX, 1529 .arg2_type = ARG_PTR_TO_MEM_OR_NULL, 1530 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1531 .arg4_type = ARG_ANYTHING, 1532 }; 1533 1534 static const struct bpf_func_proto * 1535 pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1536 { 1537 switch (func_id) { 1538 case BPF_FUNC_perf_event_output: 1539 return &bpf_perf_event_output_proto_tp; 1540 case BPF_FUNC_get_stackid: 1541 return &bpf_get_stackid_proto_pe; 1542 case BPF_FUNC_get_stack: 1543 return &bpf_get_stack_proto_pe; 1544 case BPF_FUNC_perf_prog_read_value: 1545 return &bpf_perf_prog_read_value_proto; 1546 case BPF_FUNC_read_branch_records: 1547 return &bpf_read_branch_records_proto; 1548 case BPF_FUNC_get_attach_cookie: 1549 return &bpf_get_attach_cookie_proto_pe; 1550 default: 1551 return bpf_tracing_func_proto(func_id, prog); 1552 } 1553 } 1554 1555 /* 1556 * bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp 1557 * to avoid potential recursive reuse issue when/if tracepoints are added 1558 * inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack. 1559 * 1560 * Since raw tracepoints run despite bpf_prog_active, support concurrent usage 1561 * in normal, irq, and nmi context. 1562 */ 1563 struct bpf_raw_tp_regs { 1564 struct pt_regs regs[3]; 1565 }; 1566 static DEFINE_PER_CPU(struct bpf_raw_tp_regs, bpf_raw_tp_regs); 1567 static DEFINE_PER_CPU(int, bpf_raw_tp_nest_level); 1568 static struct pt_regs *get_bpf_raw_tp_regs(void) 1569 { 1570 struct bpf_raw_tp_regs *tp_regs = this_cpu_ptr(&bpf_raw_tp_regs); 1571 int nest_level = this_cpu_inc_return(bpf_raw_tp_nest_level); 1572 1573 if (nest_level > ARRAY_SIZE(tp_regs->regs)) { 1574 this_cpu_dec(bpf_raw_tp_nest_level); 1575 return ERR_PTR(-EBUSY); 1576 } 1577 1578 return &tp_regs->regs[nest_level - 1]; 1579 } 1580 1581 static void put_bpf_raw_tp_regs(void) 1582 { 1583 this_cpu_dec(bpf_raw_tp_nest_level); 1584 } 1585 1586 BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args, 1587 struct bpf_map *, map, u64, flags, void *, data, u64, size) 1588 { 1589 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1590 int ret; 1591 1592 if (IS_ERR(regs)) 1593 return PTR_ERR(regs); 1594 1595 perf_fetch_caller_regs(regs); 1596 ret = ____bpf_perf_event_output(regs, map, flags, data, size); 1597 1598 put_bpf_raw_tp_regs(); 1599 return ret; 1600 } 1601 1602 static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = { 1603 .func = bpf_perf_event_output_raw_tp, 1604 .gpl_only = true, 1605 .ret_type = RET_INTEGER, 1606 .arg1_type = ARG_PTR_TO_CTX, 1607 .arg2_type = ARG_CONST_MAP_PTR, 1608 .arg3_type = ARG_ANYTHING, 1609 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1610 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 1611 }; 1612 1613 extern const struct bpf_func_proto bpf_skb_output_proto; 1614 extern const struct bpf_func_proto bpf_xdp_output_proto; 1615 extern const struct bpf_func_proto bpf_xdp_get_buff_len_trace_proto; 1616 1617 BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args, 1618 struct bpf_map *, map, u64, flags) 1619 { 1620 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1621 int ret; 1622 1623 if (IS_ERR(regs)) 1624 return PTR_ERR(regs); 1625 1626 perf_fetch_caller_regs(regs); 1627 /* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */ 1628 ret = bpf_get_stackid((unsigned long) regs, (unsigned long) map, 1629 flags, 0, 0); 1630 put_bpf_raw_tp_regs(); 1631 return ret; 1632 } 1633 1634 static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = { 1635 .func = bpf_get_stackid_raw_tp, 1636 .gpl_only = true, 1637 .ret_type = RET_INTEGER, 1638 .arg1_type = ARG_PTR_TO_CTX, 1639 .arg2_type = ARG_CONST_MAP_PTR, 1640 .arg3_type = ARG_ANYTHING, 1641 }; 1642 1643 BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args, 1644 void *, buf, u32, size, u64, flags) 1645 { 1646 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1647 int ret; 1648 1649 if (IS_ERR(regs)) 1650 return PTR_ERR(regs); 1651 1652 perf_fetch_caller_regs(regs); 1653 ret = bpf_get_stack((unsigned long) regs, (unsigned long) buf, 1654 (unsigned long) size, flags, 0); 1655 put_bpf_raw_tp_regs(); 1656 return ret; 1657 } 1658 1659 static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = { 1660 .func = bpf_get_stack_raw_tp, 1661 .gpl_only = true, 1662 .ret_type = RET_INTEGER, 1663 .arg1_type = ARG_PTR_TO_CTX, 1664 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1665 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1666 .arg4_type = ARG_ANYTHING, 1667 }; 1668 1669 static const struct bpf_func_proto * 1670 raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1671 { 1672 switch (func_id) { 1673 case BPF_FUNC_perf_event_output: 1674 return &bpf_perf_event_output_proto_raw_tp; 1675 case BPF_FUNC_get_stackid: 1676 return &bpf_get_stackid_proto_raw_tp; 1677 case BPF_FUNC_get_stack: 1678 return &bpf_get_stack_proto_raw_tp; 1679 case BPF_FUNC_get_attach_cookie: 1680 return &bpf_get_attach_cookie_proto_tracing; 1681 default: 1682 return bpf_tracing_func_proto(func_id, prog); 1683 } 1684 } 1685 1686 const struct bpf_func_proto * 1687 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1688 { 1689 const struct bpf_func_proto *fn; 1690 1691 switch (func_id) { 1692 #ifdef CONFIG_NET 1693 case BPF_FUNC_skb_output: 1694 return &bpf_skb_output_proto; 1695 case BPF_FUNC_xdp_output: 1696 return &bpf_xdp_output_proto; 1697 case BPF_FUNC_skc_to_tcp6_sock: 1698 return &bpf_skc_to_tcp6_sock_proto; 1699 case BPF_FUNC_skc_to_tcp_sock: 1700 return &bpf_skc_to_tcp_sock_proto; 1701 case BPF_FUNC_skc_to_tcp_timewait_sock: 1702 return &bpf_skc_to_tcp_timewait_sock_proto; 1703 case BPF_FUNC_skc_to_tcp_request_sock: 1704 return &bpf_skc_to_tcp_request_sock_proto; 1705 case BPF_FUNC_skc_to_udp6_sock: 1706 return &bpf_skc_to_udp6_sock_proto; 1707 case BPF_FUNC_skc_to_unix_sock: 1708 return &bpf_skc_to_unix_sock_proto; 1709 case BPF_FUNC_skc_to_mptcp_sock: 1710 return &bpf_skc_to_mptcp_sock_proto; 1711 case BPF_FUNC_sk_storage_get: 1712 return &bpf_sk_storage_get_tracing_proto; 1713 case BPF_FUNC_sk_storage_delete: 1714 return &bpf_sk_storage_delete_tracing_proto; 1715 case BPF_FUNC_sock_from_file: 1716 return &bpf_sock_from_file_proto; 1717 case BPF_FUNC_get_socket_cookie: 1718 return &bpf_get_socket_ptr_cookie_proto; 1719 case BPF_FUNC_xdp_get_buff_len: 1720 return &bpf_xdp_get_buff_len_trace_proto; 1721 #endif 1722 case BPF_FUNC_seq_printf: 1723 return prog->expected_attach_type == BPF_TRACE_ITER ? 1724 &bpf_seq_printf_proto : 1725 NULL; 1726 case BPF_FUNC_seq_write: 1727 return prog->expected_attach_type == BPF_TRACE_ITER ? 1728 &bpf_seq_write_proto : 1729 NULL; 1730 case BPF_FUNC_seq_printf_btf: 1731 return prog->expected_attach_type == BPF_TRACE_ITER ? 1732 &bpf_seq_printf_btf_proto : 1733 NULL; 1734 case BPF_FUNC_d_path: 1735 return &bpf_d_path_proto; 1736 case BPF_FUNC_get_func_arg: 1737 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_proto : NULL; 1738 case BPF_FUNC_get_func_ret: 1739 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_ret_proto : NULL; 1740 case BPF_FUNC_get_func_arg_cnt: 1741 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_cnt_proto : NULL; 1742 case BPF_FUNC_get_attach_cookie: 1743 if (prog->type == BPF_PROG_TYPE_TRACING && 1744 prog->expected_attach_type == BPF_TRACE_RAW_TP) 1745 return &bpf_get_attach_cookie_proto_tracing; 1746 return bpf_prog_has_trampoline(prog) ? &bpf_get_attach_cookie_proto_tracing : NULL; 1747 default: 1748 fn = raw_tp_prog_func_proto(func_id, prog); 1749 if (!fn && prog->expected_attach_type == BPF_TRACE_ITER) 1750 fn = bpf_iter_get_func_proto(func_id, prog); 1751 return fn; 1752 } 1753 } 1754 1755 static bool raw_tp_prog_is_valid_access(int off, int size, 1756 enum bpf_access_type type, 1757 const struct bpf_prog *prog, 1758 struct bpf_insn_access_aux *info) 1759 { 1760 return bpf_tracing_ctx_access(off, size, type); 1761 } 1762 1763 static bool tracing_prog_is_valid_access(int off, int size, 1764 enum bpf_access_type type, 1765 const struct bpf_prog *prog, 1766 struct bpf_insn_access_aux *info) 1767 { 1768 return bpf_tracing_btf_ctx_access(off, size, type, prog, info); 1769 } 1770 1771 int __weak bpf_prog_test_run_tracing(struct bpf_prog *prog, 1772 const union bpf_attr *kattr, 1773 union bpf_attr __user *uattr) 1774 { 1775 return -ENOTSUPP; 1776 } 1777 1778 const struct bpf_verifier_ops raw_tracepoint_verifier_ops = { 1779 .get_func_proto = raw_tp_prog_func_proto, 1780 .is_valid_access = raw_tp_prog_is_valid_access, 1781 }; 1782 1783 const struct bpf_prog_ops raw_tracepoint_prog_ops = { 1784 #ifdef CONFIG_NET 1785 .test_run = bpf_prog_test_run_raw_tp, 1786 #endif 1787 }; 1788 1789 const struct bpf_verifier_ops tracing_verifier_ops = { 1790 .get_func_proto = tracing_prog_func_proto, 1791 .is_valid_access = tracing_prog_is_valid_access, 1792 }; 1793 1794 const struct bpf_prog_ops tracing_prog_ops = { 1795 .test_run = bpf_prog_test_run_tracing, 1796 }; 1797 1798 static bool raw_tp_writable_prog_is_valid_access(int off, int size, 1799 enum bpf_access_type type, 1800 const struct bpf_prog *prog, 1801 struct bpf_insn_access_aux *info) 1802 { 1803 if (off == 0) { 1804 if (size != sizeof(u64) || type != BPF_READ) 1805 return false; 1806 info->reg_type = PTR_TO_TP_BUFFER; 1807 } 1808 return raw_tp_prog_is_valid_access(off, size, type, prog, info); 1809 } 1810 1811 const struct bpf_verifier_ops raw_tracepoint_writable_verifier_ops = { 1812 .get_func_proto = raw_tp_prog_func_proto, 1813 .is_valid_access = raw_tp_writable_prog_is_valid_access, 1814 }; 1815 1816 const struct bpf_prog_ops raw_tracepoint_writable_prog_ops = { 1817 }; 1818 1819 static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type, 1820 const struct bpf_prog *prog, 1821 struct bpf_insn_access_aux *info) 1822 { 1823 const int size_u64 = sizeof(u64); 1824 1825 if (off < 0 || off >= sizeof(struct bpf_perf_event_data)) 1826 return false; 1827 if (type != BPF_READ) 1828 return false; 1829 if (off % size != 0) { 1830 if (sizeof(unsigned long) != 4) 1831 return false; 1832 if (size != 8) 1833 return false; 1834 if (off % size != 4) 1835 return false; 1836 } 1837 1838 switch (off) { 1839 case bpf_ctx_range(struct bpf_perf_event_data, sample_period): 1840 bpf_ctx_record_field_size(info, size_u64); 1841 if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) 1842 return false; 1843 break; 1844 case bpf_ctx_range(struct bpf_perf_event_data, addr): 1845 bpf_ctx_record_field_size(info, size_u64); 1846 if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) 1847 return false; 1848 break; 1849 default: 1850 if (size != sizeof(long)) 1851 return false; 1852 } 1853 1854 return true; 1855 } 1856 1857 static u32 pe_prog_convert_ctx_access(enum bpf_access_type type, 1858 const struct bpf_insn *si, 1859 struct bpf_insn *insn_buf, 1860 struct bpf_prog *prog, u32 *target_size) 1861 { 1862 struct bpf_insn *insn = insn_buf; 1863 1864 switch (si->off) { 1865 case offsetof(struct bpf_perf_event_data, sample_period): 1866 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 1867 data), si->dst_reg, si->src_reg, 1868 offsetof(struct bpf_perf_event_data_kern, data)); 1869 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, 1870 bpf_target_off(struct perf_sample_data, period, 8, 1871 target_size)); 1872 break; 1873 case offsetof(struct bpf_perf_event_data, addr): 1874 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 1875 data), si->dst_reg, si->src_reg, 1876 offsetof(struct bpf_perf_event_data_kern, data)); 1877 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, 1878 bpf_target_off(struct perf_sample_data, addr, 8, 1879 target_size)); 1880 break; 1881 default: 1882 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 1883 regs), si->dst_reg, si->src_reg, 1884 offsetof(struct bpf_perf_event_data_kern, regs)); 1885 *insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg, 1886 si->off); 1887 break; 1888 } 1889 1890 return insn - insn_buf; 1891 } 1892 1893 const struct bpf_verifier_ops perf_event_verifier_ops = { 1894 .get_func_proto = pe_prog_func_proto, 1895 .is_valid_access = pe_prog_is_valid_access, 1896 .convert_ctx_access = pe_prog_convert_ctx_access, 1897 }; 1898 1899 const struct bpf_prog_ops perf_event_prog_ops = { 1900 }; 1901 1902 static DEFINE_MUTEX(bpf_event_mutex); 1903 1904 #define BPF_TRACE_MAX_PROGS 64 1905 1906 int perf_event_attach_bpf_prog(struct perf_event *event, 1907 struct bpf_prog *prog, 1908 u64 bpf_cookie) 1909 { 1910 struct bpf_prog_array *old_array; 1911 struct bpf_prog_array *new_array; 1912 int ret = -EEXIST; 1913 1914 /* 1915 * Kprobe override only works if they are on the function entry, 1916 * and only if they are on the opt-in list. 1917 */ 1918 if (prog->kprobe_override && 1919 (!trace_kprobe_on_func_entry(event->tp_event) || 1920 !trace_kprobe_error_injectable(event->tp_event))) 1921 return -EINVAL; 1922 1923 mutex_lock(&bpf_event_mutex); 1924 1925 if (event->prog) 1926 goto unlock; 1927 1928 old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); 1929 if (old_array && 1930 bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) { 1931 ret = -E2BIG; 1932 goto unlock; 1933 } 1934 1935 ret = bpf_prog_array_copy(old_array, NULL, prog, bpf_cookie, &new_array); 1936 if (ret < 0) 1937 goto unlock; 1938 1939 /* set the new array to event->tp_event and set event->prog */ 1940 event->prog = prog; 1941 event->bpf_cookie = bpf_cookie; 1942 rcu_assign_pointer(event->tp_event->prog_array, new_array); 1943 bpf_prog_array_free_sleepable(old_array); 1944 1945 unlock: 1946 mutex_unlock(&bpf_event_mutex); 1947 return ret; 1948 } 1949 1950 void perf_event_detach_bpf_prog(struct perf_event *event) 1951 { 1952 struct bpf_prog_array *old_array; 1953 struct bpf_prog_array *new_array; 1954 struct bpf_prog *prog = NULL; 1955 int ret; 1956 1957 mutex_lock(&bpf_event_mutex); 1958 1959 if (!event->prog) 1960 goto unlock; 1961 1962 old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); 1963 if (!old_array) 1964 goto put; 1965 1966 ret = bpf_prog_array_copy(old_array, event->prog, NULL, 0, &new_array); 1967 if (ret < 0) { 1968 bpf_prog_array_delete_safe(old_array, event->prog); 1969 } else { 1970 rcu_assign_pointer(event->tp_event->prog_array, new_array); 1971 bpf_prog_array_free_sleepable(old_array); 1972 } 1973 1974 put: 1975 prog = event->prog; 1976 event->prog = NULL; 1977 1978 unlock: 1979 mutex_unlock(&bpf_event_mutex); 1980 1981 if (prog) { 1982 /* 1983 * It could be that the bpf_prog is not sleepable (and will be freed 1984 * via normal RCU), but is called from a point that supports sleepable 1985 * programs and uses tasks-trace-RCU. 1986 */ 1987 synchronize_rcu_tasks_trace(); 1988 1989 bpf_prog_put(prog); 1990 } 1991 } 1992 1993 int perf_event_query_prog_array(struct perf_event *event, void __user *info) 1994 { 1995 struct perf_event_query_bpf __user *uquery = info; 1996 struct perf_event_query_bpf query = {}; 1997 struct bpf_prog_array *progs; 1998 u32 *ids, prog_cnt, ids_len; 1999 int ret; 2000 2001 if (!perfmon_capable()) 2002 return -EPERM; 2003 if (event->attr.type != PERF_TYPE_TRACEPOINT) 2004 return -EINVAL; 2005 if (copy_from_user(&query, uquery, sizeof(query))) 2006 return -EFAULT; 2007 2008 ids_len = query.ids_len; 2009 if (ids_len > BPF_TRACE_MAX_PROGS) 2010 return -E2BIG; 2011 ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN); 2012 if (!ids) 2013 return -ENOMEM; 2014 /* 2015 * The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which 2016 * is required when user only wants to check for uquery->prog_cnt. 2017 * There is no need to check for it since the case is handled 2018 * gracefully in bpf_prog_array_copy_info. 2019 */ 2020 2021 mutex_lock(&bpf_event_mutex); 2022 progs = bpf_event_rcu_dereference(event->tp_event->prog_array); 2023 ret = bpf_prog_array_copy_info(progs, ids, ids_len, &prog_cnt); 2024 mutex_unlock(&bpf_event_mutex); 2025 2026 if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) || 2027 copy_to_user(uquery->ids, ids, ids_len * sizeof(u32))) 2028 ret = -EFAULT; 2029 2030 kfree(ids); 2031 return ret; 2032 } 2033 2034 extern struct bpf_raw_event_map __start__bpf_raw_tp[]; 2035 extern struct bpf_raw_event_map __stop__bpf_raw_tp[]; 2036 2037 struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name) 2038 { 2039 struct bpf_raw_event_map *btp = __start__bpf_raw_tp; 2040 2041 for (; btp < __stop__bpf_raw_tp; btp++) { 2042 if (!strcmp(btp->tp->name, name)) 2043 return btp; 2044 } 2045 2046 return bpf_get_raw_tracepoint_module(name); 2047 } 2048 2049 void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp) 2050 { 2051 struct module *mod; 2052 2053 guard(rcu)(); 2054 mod = __module_address((unsigned long)btp); 2055 module_put(mod); 2056 } 2057 2058 static __always_inline 2059 void __bpf_trace_run(struct bpf_raw_tp_link *link, u64 *args) 2060 { 2061 struct bpf_prog *prog = link->link.prog; 2062 struct bpf_run_ctx *old_run_ctx; 2063 struct bpf_trace_run_ctx run_ctx; 2064 2065 cant_sleep(); 2066 if (unlikely(this_cpu_inc_return(*(prog->active)) != 1)) { 2067 bpf_prog_inc_misses_counter(prog); 2068 goto out; 2069 } 2070 2071 run_ctx.bpf_cookie = link->cookie; 2072 old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx); 2073 2074 rcu_read_lock(); 2075 (void) bpf_prog_run(prog, args); 2076 rcu_read_unlock(); 2077 2078 bpf_reset_run_ctx(old_run_ctx); 2079 out: 2080 this_cpu_dec(*(prog->active)); 2081 } 2082 2083 #define UNPACK(...) __VA_ARGS__ 2084 #define REPEAT_1(FN, DL, X, ...) FN(X) 2085 #define REPEAT_2(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__) 2086 #define REPEAT_3(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_2(FN, DL, __VA_ARGS__) 2087 #define REPEAT_4(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_3(FN, DL, __VA_ARGS__) 2088 #define REPEAT_5(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_4(FN, DL, __VA_ARGS__) 2089 #define REPEAT_6(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_5(FN, DL, __VA_ARGS__) 2090 #define REPEAT_7(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_6(FN, DL, __VA_ARGS__) 2091 #define REPEAT_8(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_7(FN, DL, __VA_ARGS__) 2092 #define REPEAT_9(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_8(FN, DL, __VA_ARGS__) 2093 #define REPEAT_10(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_9(FN, DL, __VA_ARGS__) 2094 #define REPEAT_11(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_10(FN, DL, __VA_ARGS__) 2095 #define REPEAT_12(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_11(FN, DL, __VA_ARGS__) 2096 #define REPEAT(X, FN, DL, ...) REPEAT_##X(FN, DL, __VA_ARGS__) 2097 2098 #define SARG(X) u64 arg##X 2099 #define COPY(X) args[X] = arg##X 2100 2101 #define __DL_COM (,) 2102 #define __DL_SEM (;) 2103 2104 #define __SEQ_0_11 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 2105 2106 #define BPF_TRACE_DEFN_x(x) \ 2107 void bpf_trace_run##x(struct bpf_raw_tp_link *link, \ 2108 REPEAT(x, SARG, __DL_COM, __SEQ_0_11)) \ 2109 { \ 2110 u64 args[x]; \ 2111 REPEAT(x, COPY, __DL_SEM, __SEQ_0_11); \ 2112 __bpf_trace_run(link, args); \ 2113 } \ 2114 EXPORT_SYMBOL_GPL(bpf_trace_run##x) 2115 BPF_TRACE_DEFN_x(1); 2116 BPF_TRACE_DEFN_x(2); 2117 BPF_TRACE_DEFN_x(3); 2118 BPF_TRACE_DEFN_x(4); 2119 BPF_TRACE_DEFN_x(5); 2120 BPF_TRACE_DEFN_x(6); 2121 BPF_TRACE_DEFN_x(7); 2122 BPF_TRACE_DEFN_x(8); 2123 BPF_TRACE_DEFN_x(9); 2124 BPF_TRACE_DEFN_x(10); 2125 BPF_TRACE_DEFN_x(11); 2126 BPF_TRACE_DEFN_x(12); 2127 2128 int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_raw_tp_link *link) 2129 { 2130 struct tracepoint *tp = btp->tp; 2131 struct bpf_prog *prog = link->link.prog; 2132 2133 /* 2134 * check that program doesn't access arguments beyond what's 2135 * available in this tracepoint 2136 */ 2137 if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64)) 2138 return -EINVAL; 2139 2140 if (prog->aux->max_tp_access > btp->writable_size) 2141 return -EINVAL; 2142 2143 return tracepoint_probe_register_may_exist(tp, (void *)btp->bpf_func, link); 2144 } 2145 2146 int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_raw_tp_link *link) 2147 { 2148 return tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, link); 2149 } 2150 2151 int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id, 2152 u32 *fd_type, const char **buf, 2153 u64 *probe_offset, u64 *probe_addr, 2154 unsigned long *missed) 2155 { 2156 bool is_tracepoint, is_syscall_tp; 2157 struct bpf_prog *prog; 2158 int flags, err = 0; 2159 2160 prog = event->prog; 2161 if (!prog) 2162 return -ENOENT; 2163 2164 /* not supporting BPF_PROG_TYPE_PERF_EVENT yet */ 2165 if (prog->type == BPF_PROG_TYPE_PERF_EVENT) 2166 return -EOPNOTSUPP; 2167 2168 *prog_id = prog->aux->id; 2169 flags = event->tp_event->flags; 2170 is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT; 2171 is_syscall_tp = is_syscall_trace_event(event->tp_event); 2172 2173 if (is_tracepoint || is_syscall_tp) { 2174 *buf = is_tracepoint ? event->tp_event->tp->name 2175 : event->tp_event->name; 2176 /* We allow NULL pointer for tracepoint */ 2177 if (fd_type) 2178 *fd_type = BPF_FD_TYPE_TRACEPOINT; 2179 if (probe_offset) 2180 *probe_offset = 0x0; 2181 if (probe_addr) 2182 *probe_addr = 0x0; 2183 } else { 2184 /* kprobe/uprobe */ 2185 err = -EOPNOTSUPP; 2186 #ifdef CONFIG_KPROBE_EVENTS 2187 if (flags & TRACE_EVENT_FL_KPROBE) 2188 err = bpf_get_kprobe_info(event, fd_type, buf, 2189 probe_offset, probe_addr, missed, 2190 event->attr.type == PERF_TYPE_TRACEPOINT); 2191 #endif 2192 #ifdef CONFIG_UPROBE_EVENTS 2193 if (flags & TRACE_EVENT_FL_UPROBE) 2194 err = bpf_get_uprobe_info(event, fd_type, buf, 2195 probe_offset, probe_addr, 2196 event->attr.type == PERF_TYPE_TRACEPOINT); 2197 #endif 2198 } 2199 2200 return err; 2201 } 2202 2203 static int __init send_signal_irq_work_init(void) 2204 { 2205 int cpu; 2206 struct send_signal_irq_work *work; 2207 2208 for_each_possible_cpu(cpu) { 2209 work = per_cpu_ptr(&send_signal_work, cpu); 2210 init_irq_work(&work->irq_work, do_bpf_send_signal); 2211 } 2212 return 0; 2213 } 2214 2215 subsys_initcall(send_signal_irq_work_init); 2216 2217 #ifdef CONFIG_MODULES 2218 static int bpf_event_notify(struct notifier_block *nb, unsigned long op, 2219 void *module) 2220 { 2221 struct bpf_trace_module *btm, *tmp; 2222 struct module *mod = module; 2223 int ret = 0; 2224 2225 if (mod->num_bpf_raw_events == 0 || 2226 (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING)) 2227 goto out; 2228 2229 mutex_lock(&bpf_module_mutex); 2230 2231 switch (op) { 2232 case MODULE_STATE_COMING: 2233 btm = kzalloc(sizeof(*btm), GFP_KERNEL); 2234 if (btm) { 2235 btm->module = module; 2236 list_add(&btm->list, &bpf_trace_modules); 2237 } else { 2238 ret = -ENOMEM; 2239 } 2240 break; 2241 case MODULE_STATE_GOING: 2242 list_for_each_entry_safe(btm, tmp, &bpf_trace_modules, list) { 2243 if (btm->module == module) { 2244 list_del(&btm->list); 2245 kfree(btm); 2246 break; 2247 } 2248 } 2249 break; 2250 } 2251 2252 mutex_unlock(&bpf_module_mutex); 2253 2254 out: 2255 return notifier_from_errno(ret); 2256 } 2257 2258 static struct notifier_block bpf_module_nb = { 2259 .notifier_call = bpf_event_notify, 2260 }; 2261 2262 static int __init bpf_event_init(void) 2263 { 2264 register_module_notifier(&bpf_module_nb); 2265 return 0; 2266 } 2267 2268 fs_initcall(bpf_event_init); 2269 #endif /* CONFIG_MODULES */ 2270 2271 struct bpf_session_run_ctx { 2272 struct bpf_run_ctx run_ctx; 2273 bool is_return; 2274 void *data; 2275 }; 2276 2277 #ifdef CONFIG_FPROBE 2278 struct bpf_kprobe_multi_link { 2279 struct bpf_link link; 2280 struct fprobe fp; 2281 unsigned long *addrs; 2282 u64 *cookies; 2283 u32 cnt; 2284 u32 mods_cnt; 2285 struct module **mods; 2286 }; 2287 2288 struct bpf_kprobe_multi_run_ctx { 2289 struct bpf_session_run_ctx session_ctx; 2290 struct bpf_kprobe_multi_link *link; 2291 unsigned long entry_ip; 2292 }; 2293 2294 struct user_syms { 2295 const char **syms; 2296 char *buf; 2297 }; 2298 2299 #ifndef CONFIG_HAVE_FTRACE_REGS_HAVING_PT_REGS 2300 static DEFINE_PER_CPU(struct pt_regs, bpf_kprobe_multi_pt_regs); 2301 #define bpf_kprobe_multi_pt_regs_ptr() this_cpu_ptr(&bpf_kprobe_multi_pt_regs) 2302 #else 2303 #define bpf_kprobe_multi_pt_regs_ptr() (NULL) 2304 #endif 2305 2306 static unsigned long ftrace_get_entry_ip(unsigned long fentry_ip) 2307 { 2308 unsigned long ip = ftrace_get_symaddr(fentry_ip); 2309 2310 return ip ? : fentry_ip; 2311 } 2312 2313 static int copy_user_syms(struct user_syms *us, unsigned long __user *usyms, u32 cnt) 2314 { 2315 unsigned long __user usymbol; 2316 const char **syms = NULL; 2317 char *buf = NULL, *p; 2318 int err = -ENOMEM; 2319 unsigned int i; 2320 2321 syms = kvmalloc_array(cnt, sizeof(*syms), GFP_KERNEL); 2322 if (!syms) 2323 goto error; 2324 2325 buf = kvmalloc_array(cnt, KSYM_NAME_LEN, GFP_KERNEL); 2326 if (!buf) 2327 goto error; 2328 2329 for (p = buf, i = 0; i < cnt; i++) { 2330 if (__get_user(usymbol, usyms + i)) { 2331 err = -EFAULT; 2332 goto error; 2333 } 2334 err = strncpy_from_user(p, (const char __user *) usymbol, KSYM_NAME_LEN); 2335 if (err == KSYM_NAME_LEN) 2336 err = -E2BIG; 2337 if (err < 0) 2338 goto error; 2339 syms[i] = p; 2340 p += err + 1; 2341 } 2342 2343 us->syms = syms; 2344 us->buf = buf; 2345 return 0; 2346 2347 error: 2348 if (err) { 2349 kvfree(syms); 2350 kvfree(buf); 2351 } 2352 return err; 2353 } 2354 2355 static void kprobe_multi_put_modules(struct module **mods, u32 cnt) 2356 { 2357 u32 i; 2358 2359 for (i = 0; i < cnt; i++) 2360 module_put(mods[i]); 2361 } 2362 2363 static void free_user_syms(struct user_syms *us) 2364 { 2365 kvfree(us->syms); 2366 kvfree(us->buf); 2367 } 2368 2369 static void bpf_kprobe_multi_link_release(struct bpf_link *link) 2370 { 2371 struct bpf_kprobe_multi_link *kmulti_link; 2372 2373 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); 2374 unregister_fprobe(&kmulti_link->fp); 2375 kprobe_multi_put_modules(kmulti_link->mods, kmulti_link->mods_cnt); 2376 } 2377 2378 static void bpf_kprobe_multi_link_dealloc(struct bpf_link *link) 2379 { 2380 struct bpf_kprobe_multi_link *kmulti_link; 2381 2382 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); 2383 kvfree(kmulti_link->addrs); 2384 kvfree(kmulti_link->cookies); 2385 kfree(kmulti_link->mods); 2386 kfree(kmulti_link); 2387 } 2388 2389 static int bpf_kprobe_multi_link_fill_link_info(const struct bpf_link *link, 2390 struct bpf_link_info *info) 2391 { 2392 u64 __user *ucookies = u64_to_user_ptr(info->kprobe_multi.cookies); 2393 u64 __user *uaddrs = u64_to_user_ptr(info->kprobe_multi.addrs); 2394 struct bpf_kprobe_multi_link *kmulti_link; 2395 u32 ucount = info->kprobe_multi.count; 2396 int err = 0, i; 2397 2398 if (!uaddrs ^ !ucount) 2399 return -EINVAL; 2400 if (ucookies && !ucount) 2401 return -EINVAL; 2402 2403 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); 2404 info->kprobe_multi.count = kmulti_link->cnt; 2405 info->kprobe_multi.flags = kmulti_link->link.flags; 2406 info->kprobe_multi.missed = kmulti_link->fp.nmissed; 2407 2408 if (!uaddrs) 2409 return 0; 2410 if (ucount < kmulti_link->cnt) 2411 err = -ENOSPC; 2412 else 2413 ucount = kmulti_link->cnt; 2414 2415 if (ucookies) { 2416 if (kmulti_link->cookies) { 2417 if (copy_to_user(ucookies, kmulti_link->cookies, ucount * sizeof(u64))) 2418 return -EFAULT; 2419 } else { 2420 for (i = 0; i < ucount; i++) { 2421 if (put_user(0, ucookies + i)) 2422 return -EFAULT; 2423 } 2424 } 2425 } 2426 2427 if (kallsyms_show_value(current_cred())) { 2428 if (copy_to_user(uaddrs, kmulti_link->addrs, ucount * sizeof(u64))) 2429 return -EFAULT; 2430 } else { 2431 for (i = 0; i < ucount; i++) { 2432 if (put_user(0, uaddrs + i)) 2433 return -EFAULT; 2434 } 2435 } 2436 return err; 2437 } 2438 2439 #ifdef CONFIG_PROC_FS 2440 static void bpf_kprobe_multi_show_fdinfo(const struct bpf_link *link, 2441 struct seq_file *seq) 2442 { 2443 struct bpf_kprobe_multi_link *kmulti_link; 2444 2445 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); 2446 2447 seq_printf(seq, 2448 "kprobe_cnt:\t%u\n" 2449 "missed:\t%lu\n", 2450 kmulti_link->cnt, 2451 kmulti_link->fp.nmissed); 2452 2453 seq_printf(seq, "%s\t %s\n", "cookie", "func"); 2454 for (int i = 0; i < kmulti_link->cnt; i++) { 2455 seq_printf(seq, 2456 "%llu\t %pS\n", 2457 kmulti_link->cookies[i], 2458 (void *)kmulti_link->addrs[i]); 2459 } 2460 } 2461 #endif 2462 2463 static const struct bpf_link_ops bpf_kprobe_multi_link_lops = { 2464 .release = bpf_kprobe_multi_link_release, 2465 .dealloc_deferred = bpf_kprobe_multi_link_dealloc, 2466 .fill_link_info = bpf_kprobe_multi_link_fill_link_info, 2467 #ifdef CONFIG_PROC_FS 2468 .show_fdinfo = bpf_kprobe_multi_show_fdinfo, 2469 #endif 2470 }; 2471 2472 static void bpf_kprobe_multi_cookie_swap(void *a, void *b, int size, const void *priv) 2473 { 2474 const struct bpf_kprobe_multi_link *link = priv; 2475 unsigned long *addr_a = a, *addr_b = b; 2476 u64 *cookie_a, *cookie_b; 2477 2478 cookie_a = link->cookies + (addr_a - link->addrs); 2479 cookie_b = link->cookies + (addr_b - link->addrs); 2480 2481 /* swap addr_a/addr_b and cookie_a/cookie_b values */ 2482 swap(*addr_a, *addr_b); 2483 swap(*cookie_a, *cookie_b); 2484 } 2485 2486 static int bpf_kprobe_multi_addrs_cmp(const void *a, const void *b) 2487 { 2488 const unsigned long *addr_a = a, *addr_b = b; 2489 2490 if (*addr_a == *addr_b) 2491 return 0; 2492 return *addr_a < *addr_b ? -1 : 1; 2493 } 2494 2495 static int bpf_kprobe_multi_cookie_cmp(const void *a, const void *b, const void *priv) 2496 { 2497 return bpf_kprobe_multi_addrs_cmp(a, b); 2498 } 2499 2500 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx) 2501 { 2502 struct bpf_kprobe_multi_run_ctx *run_ctx; 2503 struct bpf_kprobe_multi_link *link; 2504 u64 *cookie, entry_ip; 2505 unsigned long *addr; 2506 2507 if (WARN_ON_ONCE(!ctx)) 2508 return 0; 2509 run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, 2510 session_ctx.run_ctx); 2511 link = run_ctx->link; 2512 if (!link->cookies) 2513 return 0; 2514 entry_ip = run_ctx->entry_ip; 2515 addr = bsearch(&entry_ip, link->addrs, link->cnt, sizeof(entry_ip), 2516 bpf_kprobe_multi_addrs_cmp); 2517 if (!addr) 2518 return 0; 2519 cookie = link->cookies + (addr - link->addrs); 2520 return *cookie; 2521 } 2522 2523 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 2524 { 2525 struct bpf_kprobe_multi_run_ctx *run_ctx; 2526 2527 run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, 2528 session_ctx.run_ctx); 2529 return run_ctx->entry_ip; 2530 } 2531 2532 static int 2533 kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link, 2534 unsigned long entry_ip, struct ftrace_regs *fregs, 2535 bool is_return, void *data) 2536 { 2537 struct bpf_kprobe_multi_run_ctx run_ctx = { 2538 .session_ctx = { 2539 .is_return = is_return, 2540 .data = data, 2541 }, 2542 .link = link, 2543 .entry_ip = entry_ip, 2544 }; 2545 struct bpf_run_ctx *old_run_ctx; 2546 struct pt_regs *regs; 2547 int err; 2548 2549 /* 2550 * graph tracer framework ensures we won't migrate, so there is no need 2551 * to use migrate_disable for bpf_prog_run again. The check here just for 2552 * __this_cpu_inc_return. 2553 */ 2554 cant_sleep(); 2555 2556 if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) { 2557 bpf_prog_inc_misses_counter(link->link.prog); 2558 err = 1; 2559 goto out; 2560 } 2561 2562 rcu_read_lock(); 2563 regs = ftrace_partial_regs(fregs, bpf_kprobe_multi_pt_regs_ptr()); 2564 old_run_ctx = bpf_set_run_ctx(&run_ctx.session_ctx.run_ctx); 2565 err = bpf_prog_run(link->link.prog, regs); 2566 bpf_reset_run_ctx(old_run_ctx); 2567 rcu_read_unlock(); 2568 2569 out: 2570 __this_cpu_dec(bpf_prog_active); 2571 return err; 2572 } 2573 2574 static int 2575 kprobe_multi_link_handler(struct fprobe *fp, unsigned long fentry_ip, 2576 unsigned long ret_ip, struct ftrace_regs *fregs, 2577 void *data) 2578 { 2579 struct bpf_kprobe_multi_link *link; 2580 int err; 2581 2582 link = container_of(fp, struct bpf_kprobe_multi_link, fp); 2583 err = kprobe_multi_link_prog_run(link, ftrace_get_entry_ip(fentry_ip), 2584 fregs, false, data); 2585 return is_kprobe_session(link->link.prog) ? err : 0; 2586 } 2587 2588 static void 2589 kprobe_multi_link_exit_handler(struct fprobe *fp, unsigned long fentry_ip, 2590 unsigned long ret_ip, struct ftrace_regs *fregs, 2591 void *data) 2592 { 2593 struct bpf_kprobe_multi_link *link; 2594 2595 link = container_of(fp, struct bpf_kprobe_multi_link, fp); 2596 kprobe_multi_link_prog_run(link, ftrace_get_entry_ip(fentry_ip), 2597 fregs, true, data); 2598 } 2599 2600 static int symbols_cmp_r(const void *a, const void *b, const void *priv) 2601 { 2602 const char **str_a = (const char **) a; 2603 const char **str_b = (const char **) b; 2604 2605 return strcmp(*str_a, *str_b); 2606 } 2607 2608 struct multi_symbols_sort { 2609 const char **funcs; 2610 u64 *cookies; 2611 }; 2612 2613 static void symbols_swap_r(void *a, void *b, int size, const void *priv) 2614 { 2615 const struct multi_symbols_sort *data = priv; 2616 const char **name_a = a, **name_b = b; 2617 2618 swap(*name_a, *name_b); 2619 2620 /* If defined, swap also related cookies. */ 2621 if (data->cookies) { 2622 u64 *cookie_a, *cookie_b; 2623 2624 cookie_a = data->cookies + (name_a - data->funcs); 2625 cookie_b = data->cookies + (name_b - data->funcs); 2626 swap(*cookie_a, *cookie_b); 2627 } 2628 } 2629 2630 struct modules_array { 2631 struct module **mods; 2632 int mods_cnt; 2633 int mods_cap; 2634 }; 2635 2636 static int add_module(struct modules_array *arr, struct module *mod) 2637 { 2638 struct module **mods; 2639 2640 if (arr->mods_cnt == arr->mods_cap) { 2641 arr->mods_cap = max(16, arr->mods_cap * 3 / 2); 2642 mods = krealloc_array(arr->mods, arr->mods_cap, sizeof(*mods), GFP_KERNEL); 2643 if (!mods) 2644 return -ENOMEM; 2645 arr->mods = mods; 2646 } 2647 2648 arr->mods[arr->mods_cnt] = mod; 2649 arr->mods_cnt++; 2650 return 0; 2651 } 2652 2653 static bool has_module(struct modules_array *arr, struct module *mod) 2654 { 2655 int i; 2656 2657 for (i = arr->mods_cnt - 1; i >= 0; i--) { 2658 if (arr->mods[i] == mod) 2659 return true; 2660 } 2661 return false; 2662 } 2663 2664 static int get_modules_for_addrs(struct module ***mods, unsigned long *addrs, u32 addrs_cnt) 2665 { 2666 struct modules_array arr = {}; 2667 u32 i, err = 0; 2668 2669 for (i = 0; i < addrs_cnt; i++) { 2670 bool skip_add = false; 2671 struct module *mod; 2672 2673 scoped_guard(rcu) { 2674 mod = __module_address(addrs[i]); 2675 /* Either no module or it's already stored */ 2676 if (!mod || has_module(&arr, mod)) { 2677 skip_add = true; 2678 break; /* scoped_guard */ 2679 } 2680 if (!try_module_get(mod)) 2681 err = -EINVAL; 2682 } 2683 if (skip_add) 2684 continue; 2685 if (err) 2686 break; 2687 err = add_module(&arr, mod); 2688 if (err) { 2689 module_put(mod); 2690 break; 2691 } 2692 } 2693 2694 /* We return either err < 0 in case of error, ... */ 2695 if (err) { 2696 kprobe_multi_put_modules(arr.mods, arr.mods_cnt); 2697 kfree(arr.mods); 2698 return err; 2699 } 2700 2701 /* or number of modules found if everything is ok. */ 2702 *mods = arr.mods; 2703 return arr.mods_cnt; 2704 } 2705 2706 static int addrs_check_error_injection_list(unsigned long *addrs, u32 cnt) 2707 { 2708 u32 i; 2709 2710 for (i = 0; i < cnt; i++) { 2711 if (!within_error_injection_list(addrs[i])) 2712 return -EINVAL; 2713 } 2714 return 0; 2715 } 2716 2717 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 2718 { 2719 struct bpf_kprobe_multi_link *link = NULL; 2720 struct bpf_link_primer link_primer; 2721 void __user *ucookies; 2722 unsigned long *addrs; 2723 u32 flags, cnt, size; 2724 void __user *uaddrs; 2725 u64 *cookies = NULL; 2726 void __user *usyms; 2727 int err; 2728 2729 /* no support for 32bit archs yet */ 2730 if (sizeof(u64) != sizeof(void *)) 2731 return -EOPNOTSUPP; 2732 2733 if (attr->link_create.flags) 2734 return -EINVAL; 2735 2736 if (!is_kprobe_multi(prog)) 2737 return -EINVAL; 2738 2739 /* Writing to context is not allowed for kprobes. */ 2740 if (prog->aux->kprobe_write_ctx) 2741 return -EINVAL; 2742 2743 flags = attr->link_create.kprobe_multi.flags; 2744 if (flags & ~BPF_F_KPROBE_MULTI_RETURN) 2745 return -EINVAL; 2746 2747 uaddrs = u64_to_user_ptr(attr->link_create.kprobe_multi.addrs); 2748 usyms = u64_to_user_ptr(attr->link_create.kprobe_multi.syms); 2749 if (!!uaddrs == !!usyms) 2750 return -EINVAL; 2751 2752 cnt = attr->link_create.kprobe_multi.cnt; 2753 if (!cnt) 2754 return -EINVAL; 2755 if (cnt > MAX_KPROBE_MULTI_CNT) 2756 return -E2BIG; 2757 2758 size = cnt * sizeof(*addrs); 2759 addrs = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL); 2760 if (!addrs) 2761 return -ENOMEM; 2762 2763 ucookies = u64_to_user_ptr(attr->link_create.kprobe_multi.cookies); 2764 if (ucookies) { 2765 cookies = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL); 2766 if (!cookies) { 2767 err = -ENOMEM; 2768 goto error; 2769 } 2770 if (copy_from_user(cookies, ucookies, size)) { 2771 err = -EFAULT; 2772 goto error; 2773 } 2774 } 2775 2776 if (uaddrs) { 2777 if (copy_from_user(addrs, uaddrs, size)) { 2778 err = -EFAULT; 2779 goto error; 2780 } 2781 } else { 2782 struct multi_symbols_sort data = { 2783 .cookies = cookies, 2784 }; 2785 struct user_syms us; 2786 2787 err = copy_user_syms(&us, usyms, cnt); 2788 if (err) 2789 goto error; 2790 2791 if (cookies) 2792 data.funcs = us.syms; 2793 2794 sort_r(us.syms, cnt, sizeof(*us.syms), symbols_cmp_r, 2795 symbols_swap_r, &data); 2796 2797 err = ftrace_lookup_symbols(us.syms, cnt, addrs); 2798 free_user_syms(&us); 2799 if (err) 2800 goto error; 2801 } 2802 2803 if (prog->kprobe_override && addrs_check_error_injection_list(addrs, cnt)) { 2804 err = -EINVAL; 2805 goto error; 2806 } 2807 2808 link = kzalloc(sizeof(*link), GFP_KERNEL); 2809 if (!link) { 2810 err = -ENOMEM; 2811 goto error; 2812 } 2813 2814 bpf_link_init(&link->link, BPF_LINK_TYPE_KPROBE_MULTI, 2815 &bpf_kprobe_multi_link_lops, prog, attr->link_create.attach_type); 2816 2817 err = bpf_link_prime(&link->link, &link_primer); 2818 if (err) 2819 goto error; 2820 2821 if (!(flags & BPF_F_KPROBE_MULTI_RETURN)) 2822 link->fp.entry_handler = kprobe_multi_link_handler; 2823 if ((flags & BPF_F_KPROBE_MULTI_RETURN) || is_kprobe_session(prog)) 2824 link->fp.exit_handler = kprobe_multi_link_exit_handler; 2825 if (is_kprobe_session(prog)) 2826 link->fp.entry_data_size = sizeof(u64); 2827 2828 link->addrs = addrs; 2829 link->cookies = cookies; 2830 link->cnt = cnt; 2831 link->link.flags = flags; 2832 2833 if (cookies) { 2834 /* 2835 * Sorting addresses will trigger sorting cookies as well 2836 * (check bpf_kprobe_multi_cookie_swap). This way we can 2837 * find cookie based on the address in bpf_get_attach_cookie 2838 * helper. 2839 */ 2840 sort_r(addrs, cnt, sizeof(*addrs), 2841 bpf_kprobe_multi_cookie_cmp, 2842 bpf_kprobe_multi_cookie_swap, 2843 link); 2844 } 2845 2846 err = get_modules_for_addrs(&link->mods, addrs, cnt); 2847 if (err < 0) { 2848 bpf_link_cleanup(&link_primer); 2849 return err; 2850 } 2851 link->mods_cnt = err; 2852 2853 err = register_fprobe_ips(&link->fp, addrs, cnt); 2854 if (err) { 2855 kprobe_multi_put_modules(link->mods, link->mods_cnt); 2856 bpf_link_cleanup(&link_primer); 2857 return err; 2858 } 2859 2860 return bpf_link_settle(&link_primer); 2861 2862 error: 2863 kfree(link); 2864 kvfree(addrs); 2865 kvfree(cookies); 2866 return err; 2867 } 2868 #else /* !CONFIG_FPROBE */ 2869 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 2870 { 2871 return -EOPNOTSUPP; 2872 } 2873 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx) 2874 { 2875 return 0; 2876 } 2877 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 2878 { 2879 return 0; 2880 } 2881 #endif 2882 2883 #ifdef CONFIG_UPROBES 2884 struct bpf_uprobe_multi_link; 2885 2886 struct bpf_uprobe { 2887 struct bpf_uprobe_multi_link *link; 2888 loff_t offset; 2889 unsigned long ref_ctr_offset; 2890 u64 cookie; 2891 struct uprobe *uprobe; 2892 struct uprobe_consumer consumer; 2893 bool session; 2894 }; 2895 2896 struct bpf_uprobe_multi_link { 2897 struct path path; 2898 struct bpf_link link; 2899 u32 cnt; 2900 struct bpf_uprobe *uprobes; 2901 struct task_struct *task; 2902 }; 2903 2904 struct bpf_uprobe_multi_run_ctx { 2905 struct bpf_session_run_ctx session_ctx; 2906 unsigned long entry_ip; 2907 struct bpf_uprobe *uprobe; 2908 }; 2909 2910 static void bpf_uprobe_unregister(struct bpf_uprobe *uprobes, u32 cnt) 2911 { 2912 u32 i; 2913 2914 for (i = 0; i < cnt; i++) 2915 uprobe_unregister_nosync(uprobes[i].uprobe, &uprobes[i].consumer); 2916 2917 if (cnt) 2918 uprobe_unregister_sync(); 2919 } 2920 2921 static void bpf_uprobe_multi_link_release(struct bpf_link *link) 2922 { 2923 struct bpf_uprobe_multi_link *umulti_link; 2924 2925 umulti_link = container_of(link, struct bpf_uprobe_multi_link, link); 2926 bpf_uprobe_unregister(umulti_link->uprobes, umulti_link->cnt); 2927 if (umulti_link->task) 2928 put_task_struct(umulti_link->task); 2929 path_put(&umulti_link->path); 2930 } 2931 2932 static void bpf_uprobe_multi_link_dealloc(struct bpf_link *link) 2933 { 2934 struct bpf_uprobe_multi_link *umulti_link; 2935 2936 umulti_link = container_of(link, struct bpf_uprobe_multi_link, link); 2937 kvfree(umulti_link->uprobes); 2938 kfree(umulti_link); 2939 } 2940 2941 static int bpf_uprobe_multi_link_fill_link_info(const struct bpf_link *link, 2942 struct bpf_link_info *info) 2943 { 2944 u64 __user *uref_ctr_offsets = u64_to_user_ptr(info->uprobe_multi.ref_ctr_offsets); 2945 u64 __user *ucookies = u64_to_user_ptr(info->uprobe_multi.cookies); 2946 u64 __user *uoffsets = u64_to_user_ptr(info->uprobe_multi.offsets); 2947 u64 __user *upath = u64_to_user_ptr(info->uprobe_multi.path); 2948 u32 upath_size = info->uprobe_multi.path_size; 2949 struct bpf_uprobe_multi_link *umulti_link; 2950 u32 ucount = info->uprobe_multi.count; 2951 int err = 0, i; 2952 char *p, *buf; 2953 long left = 0; 2954 2955 if (!upath ^ !upath_size) 2956 return -EINVAL; 2957 2958 if ((uoffsets || uref_ctr_offsets || ucookies) && !ucount) 2959 return -EINVAL; 2960 2961 umulti_link = container_of(link, struct bpf_uprobe_multi_link, link); 2962 info->uprobe_multi.count = umulti_link->cnt; 2963 info->uprobe_multi.flags = umulti_link->link.flags; 2964 info->uprobe_multi.pid = umulti_link->task ? 2965 task_pid_nr_ns(umulti_link->task, task_active_pid_ns(current)) : 0; 2966 2967 upath_size = upath_size ? min_t(u32, upath_size, PATH_MAX) : PATH_MAX; 2968 buf = kmalloc(upath_size, GFP_KERNEL); 2969 if (!buf) 2970 return -ENOMEM; 2971 p = d_path(&umulti_link->path, buf, upath_size); 2972 if (IS_ERR(p)) { 2973 kfree(buf); 2974 return PTR_ERR(p); 2975 } 2976 upath_size = buf + upath_size - p; 2977 2978 if (upath) 2979 left = copy_to_user(upath, p, upath_size); 2980 kfree(buf); 2981 if (left) 2982 return -EFAULT; 2983 info->uprobe_multi.path_size = upath_size; 2984 2985 if (!uoffsets && !ucookies && !uref_ctr_offsets) 2986 return 0; 2987 2988 if (ucount < umulti_link->cnt) 2989 err = -ENOSPC; 2990 else 2991 ucount = umulti_link->cnt; 2992 2993 for (i = 0; i < ucount; i++) { 2994 if (uoffsets && 2995 put_user(umulti_link->uprobes[i].offset, uoffsets + i)) 2996 return -EFAULT; 2997 if (uref_ctr_offsets && 2998 put_user(umulti_link->uprobes[i].ref_ctr_offset, uref_ctr_offsets + i)) 2999 return -EFAULT; 3000 if (ucookies && 3001 put_user(umulti_link->uprobes[i].cookie, ucookies + i)) 3002 return -EFAULT; 3003 } 3004 3005 return err; 3006 } 3007 3008 #ifdef CONFIG_PROC_FS 3009 static void bpf_uprobe_multi_show_fdinfo(const struct bpf_link *link, 3010 struct seq_file *seq) 3011 { 3012 struct bpf_uprobe_multi_link *umulti_link; 3013 char *p, *buf; 3014 pid_t pid; 3015 3016 umulti_link = container_of(link, struct bpf_uprobe_multi_link, link); 3017 3018 buf = kmalloc(PATH_MAX, GFP_KERNEL); 3019 if (!buf) 3020 return; 3021 3022 p = d_path(&umulti_link->path, buf, PATH_MAX); 3023 if (IS_ERR(p)) { 3024 kfree(buf); 3025 return; 3026 } 3027 3028 pid = umulti_link->task ? 3029 task_pid_nr_ns(umulti_link->task, task_active_pid_ns(current)) : 0; 3030 seq_printf(seq, 3031 "uprobe_cnt:\t%u\n" 3032 "pid:\t%u\n" 3033 "path:\t%s\n", 3034 umulti_link->cnt, pid, p); 3035 3036 seq_printf(seq, "%s\t %s\t %s\n", "cookie", "offset", "ref_ctr_offset"); 3037 for (int i = 0; i < umulti_link->cnt; i++) { 3038 seq_printf(seq, 3039 "%llu\t %#llx\t %#lx\n", 3040 umulti_link->uprobes[i].cookie, 3041 umulti_link->uprobes[i].offset, 3042 umulti_link->uprobes[i].ref_ctr_offset); 3043 } 3044 3045 kfree(buf); 3046 } 3047 #endif 3048 3049 static const struct bpf_link_ops bpf_uprobe_multi_link_lops = { 3050 .release = bpf_uprobe_multi_link_release, 3051 .dealloc_deferred = bpf_uprobe_multi_link_dealloc, 3052 .fill_link_info = bpf_uprobe_multi_link_fill_link_info, 3053 #ifdef CONFIG_PROC_FS 3054 .show_fdinfo = bpf_uprobe_multi_show_fdinfo, 3055 #endif 3056 }; 3057 3058 static int uprobe_prog_run(struct bpf_uprobe *uprobe, 3059 unsigned long entry_ip, 3060 struct pt_regs *regs, 3061 bool is_return, void *data) 3062 { 3063 struct bpf_uprobe_multi_link *link = uprobe->link; 3064 struct bpf_uprobe_multi_run_ctx run_ctx = { 3065 .session_ctx = { 3066 .is_return = is_return, 3067 .data = data, 3068 }, 3069 .entry_ip = entry_ip, 3070 .uprobe = uprobe, 3071 }; 3072 struct bpf_prog *prog = link->link.prog; 3073 bool sleepable = prog->sleepable; 3074 struct bpf_run_ctx *old_run_ctx; 3075 int err; 3076 3077 if (link->task && !same_thread_group(current, link->task)) 3078 return 0; 3079 3080 if (sleepable) 3081 rcu_read_lock_trace(); 3082 else 3083 rcu_read_lock(); 3084 3085 migrate_disable(); 3086 3087 old_run_ctx = bpf_set_run_ctx(&run_ctx.session_ctx.run_ctx); 3088 err = bpf_prog_run(link->link.prog, regs); 3089 bpf_reset_run_ctx(old_run_ctx); 3090 3091 migrate_enable(); 3092 3093 if (sleepable) 3094 rcu_read_unlock_trace(); 3095 else 3096 rcu_read_unlock(); 3097 return err; 3098 } 3099 3100 static bool 3101 uprobe_multi_link_filter(struct uprobe_consumer *con, struct mm_struct *mm) 3102 { 3103 struct bpf_uprobe *uprobe; 3104 3105 uprobe = container_of(con, struct bpf_uprobe, consumer); 3106 return uprobe->link->task->mm == mm; 3107 } 3108 3109 static int 3110 uprobe_multi_link_handler(struct uprobe_consumer *con, struct pt_regs *regs, 3111 __u64 *data) 3112 { 3113 struct bpf_uprobe *uprobe; 3114 int ret; 3115 3116 uprobe = container_of(con, struct bpf_uprobe, consumer); 3117 ret = uprobe_prog_run(uprobe, instruction_pointer(regs), regs, false, data); 3118 if (uprobe->session) 3119 return ret ? UPROBE_HANDLER_IGNORE : 0; 3120 return 0; 3121 } 3122 3123 static int 3124 uprobe_multi_link_ret_handler(struct uprobe_consumer *con, unsigned long func, struct pt_regs *regs, 3125 __u64 *data) 3126 { 3127 struct bpf_uprobe *uprobe; 3128 3129 uprobe = container_of(con, struct bpf_uprobe, consumer); 3130 uprobe_prog_run(uprobe, func, regs, true, data); 3131 return 0; 3132 } 3133 3134 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 3135 { 3136 struct bpf_uprobe_multi_run_ctx *run_ctx; 3137 3138 run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx, 3139 session_ctx.run_ctx); 3140 return run_ctx->entry_ip; 3141 } 3142 3143 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx) 3144 { 3145 struct bpf_uprobe_multi_run_ctx *run_ctx; 3146 3147 run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx, 3148 session_ctx.run_ctx); 3149 return run_ctx->uprobe->cookie; 3150 } 3151 3152 int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 3153 { 3154 struct bpf_uprobe_multi_link *link = NULL; 3155 unsigned long __user *uref_ctr_offsets; 3156 struct bpf_link_primer link_primer; 3157 struct bpf_uprobe *uprobes = NULL; 3158 struct task_struct *task = NULL; 3159 unsigned long __user *uoffsets; 3160 u64 __user *ucookies; 3161 void __user *upath; 3162 u32 flags, cnt, i; 3163 struct path path; 3164 char *name; 3165 pid_t pid; 3166 int err; 3167 3168 /* no support for 32bit archs yet */ 3169 if (sizeof(u64) != sizeof(void *)) 3170 return -EOPNOTSUPP; 3171 3172 if (attr->link_create.flags) 3173 return -EINVAL; 3174 3175 if (!is_uprobe_multi(prog)) 3176 return -EINVAL; 3177 3178 flags = attr->link_create.uprobe_multi.flags; 3179 if (flags & ~BPF_F_UPROBE_MULTI_RETURN) 3180 return -EINVAL; 3181 3182 /* 3183 * path, offsets and cnt are mandatory, 3184 * ref_ctr_offsets and cookies are optional 3185 */ 3186 upath = u64_to_user_ptr(attr->link_create.uprobe_multi.path); 3187 uoffsets = u64_to_user_ptr(attr->link_create.uprobe_multi.offsets); 3188 cnt = attr->link_create.uprobe_multi.cnt; 3189 pid = attr->link_create.uprobe_multi.pid; 3190 3191 if (!upath || !uoffsets || !cnt || pid < 0) 3192 return -EINVAL; 3193 if (cnt > MAX_UPROBE_MULTI_CNT) 3194 return -E2BIG; 3195 3196 uref_ctr_offsets = u64_to_user_ptr(attr->link_create.uprobe_multi.ref_ctr_offsets); 3197 ucookies = u64_to_user_ptr(attr->link_create.uprobe_multi.cookies); 3198 3199 name = strndup_user(upath, PATH_MAX); 3200 if (IS_ERR(name)) { 3201 err = PTR_ERR(name); 3202 return err; 3203 } 3204 3205 err = kern_path(name, LOOKUP_FOLLOW, &path); 3206 kfree(name); 3207 if (err) 3208 return err; 3209 3210 if (!d_is_reg(path.dentry)) { 3211 err = -EBADF; 3212 goto error_path_put; 3213 } 3214 3215 if (pid) { 3216 rcu_read_lock(); 3217 task = get_pid_task(find_vpid(pid), PIDTYPE_TGID); 3218 rcu_read_unlock(); 3219 if (!task) { 3220 err = -ESRCH; 3221 goto error_path_put; 3222 } 3223 } 3224 3225 err = -ENOMEM; 3226 3227 link = kzalloc(sizeof(*link), GFP_KERNEL); 3228 uprobes = kvcalloc(cnt, sizeof(*uprobes), GFP_KERNEL); 3229 3230 if (!uprobes || !link) 3231 goto error_free; 3232 3233 for (i = 0; i < cnt; i++) { 3234 if (__get_user(uprobes[i].offset, uoffsets + i)) { 3235 err = -EFAULT; 3236 goto error_free; 3237 } 3238 if (uprobes[i].offset < 0) { 3239 err = -EINVAL; 3240 goto error_free; 3241 } 3242 if (uref_ctr_offsets && __get_user(uprobes[i].ref_ctr_offset, uref_ctr_offsets + i)) { 3243 err = -EFAULT; 3244 goto error_free; 3245 } 3246 if (ucookies && __get_user(uprobes[i].cookie, ucookies + i)) { 3247 err = -EFAULT; 3248 goto error_free; 3249 } 3250 3251 uprobes[i].link = link; 3252 3253 if (!(flags & BPF_F_UPROBE_MULTI_RETURN)) 3254 uprobes[i].consumer.handler = uprobe_multi_link_handler; 3255 if (flags & BPF_F_UPROBE_MULTI_RETURN || is_uprobe_session(prog)) 3256 uprobes[i].consumer.ret_handler = uprobe_multi_link_ret_handler; 3257 if (is_uprobe_session(prog)) 3258 uprobes[i].session = true; 3259 if (pid) 3260 uprobes[i].consumer.filter = uprobe_multi_link_filter; 3261 } 3262 3263 link->cnt = cnt; 3264 link->uprobes = uprobes; 3265 link->path = path; 3266 link->task = task; 3267 link->link.flags = flags; 3268 3269 bpf_link_init(&link->link, BPF_LINK_TYPE_UPROBE_MULTI, 3270 &bpf_uprobe_multi_link_lops, prog, attr->link_create.attach_type); 3271 3272 for (i = 0; i < cnt; i++) { 3273 uprobes[i].uprobe = uprobe_register(d_real_inode(link->path.dentry), 3274 uprobes[i].offset, 3275 uprobes[i].ref_ctr_offset, 3276 &uprobes[i].consumer); 3277 if (IS_ERR(uprobes[i].uprobe)) { 3278 err = PTR_ERR(uprobes[i].uprobe); 3279 link->cnt = i; 3280 goto error_unregister; 3281 } 3282 } 3283 3284 err = bpf_link_prime(&link->link, &link_primer); 3285 if (err) 3286 goto error_unregister; 3287 3288 return bpf_link_settle(&link_primer); 3289 3290 error_unregister: 3291 bpf_uprobe_unregister(uprobes, link->cnt); 3292 3293 error_free: 3294 kvfree(uprobes); 3295 kfree(link); 3296 if (task) 3297 put_task_struct(task); 3298 error_path_put: 3299 path_put(&path); 3300 return err; 3301 } 3302 #else /* !CONFIG_UPROBES */ 3303 int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 3304 { 3305 return -EOPNOTSUPP; 3306 } 3307 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx) 3308 { 3309 return 0; 3310 } 3311 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 3312 { 3313 return 0; 3314 } 3315 #endif /* CONFIG_UPROBES */ 3316 3317 __bpf_kfunc_start_defs(); 3318 3319 __bpf_kfunc bool bpf_session_is_return(void) 3320 { 3321 struct bpf_session_run_ctx *session_ctx; 3322 3323 session_ctx = container_of(current->bpf_ctx, struct bpf_session_run_ctx, run_ctx); 3324 return session_ctx->is_return; 3325 } 3326 3327 __bpf_kfunc __u64 *bpf_session_cookie(void) 3328 { 3329 struct bpf_session_run_ctx *session_ctx; 3330 3331 session_ctx = container_of(current->bpf_ctx, struct bpf_session_run_ctx, run_ctx); 3332 return session_ctx->data; 3333 } 3334 3335 __bpf_kfunc_end_defs(); 3336 3337 BTF_KFUNCS_START(kprobe_multi_kfunc_set_ids) 3338 BTF_ID_FLAGS(func, bpf_session_is_return) 3339 BTF_ID_FLAGS(func, bpf_session_cookie) 3340 BTF_KFUNCS_END(kprobe_multi_kfunc_set_ids) 3341 3342 static int bpf_kprobe_multi_filter(const struct bpf_prog *prog, u32 kfunc_id) 3343 { 3344 if (!btf_id_set8_contains(&kprobe_multi_kfunc_set_ids, kfunc_id)) 3345 return 0; 3346 3347 if (!is_kprobe_session(prog) && !is_uprobe_session(prog)) 3348 return -EACCES; 3349 3350 return 0; 3351 } 3352 3353 static const struct btf_kfunc_id_set bpf_kprobe_multi_kfunc_set = { 3354 .owner = THIS_MODULE, 3355 .set = &kprobe_multi_kfunc_set_ids, 3356 .filter = bpf_kprobe_multi_filter, 3357 }; 3358 3359 static int __init bpf_kprobe_multi_kfuncs_init(void) 3360 { 3361 return register_btf_kfunc_id_set(BPF_PROG_TYPE_KPROBE, &bpf_kprobe_multi_kfunc_set); 3362 } 3363 3364 late_initcall(bpf_kprobe_multi_kfuncs_init); 3365 3366 typedef int (*copy_fn_t)(void *dst, const void *src, u32 size, struct task_struct *tsk); 3367 3368 /* 3369 * The __always_inline is to make sure the compiler doesn't 3370 * generate indirect calls into callbacks, which is expensive, 3371 * on some kernel configurations. This allows compiler to put 3372 * direct calls into all the specific callback implementations 3373 * (copy_user_data_sleepable, copy_user_data_nofault, and so on) 3374 */ 3375 static __always_inline int __bpf_dynptr_copy_str(struct bpf_dynptr *dptr, u32 doff, u32 size, 3376 const void *unsafe_src, 3377 copy_fn_t str_copy_fn, 3378 struct task_struct *tsk) 3379 { 3380 struct bpf_dynptr_kern *dst; 3381 u32 chunk_sz, off; 3382 void *dst_slice; 3383 int cnt, err; 3384 char buf[256]; 3385 3386 dst_slice = bpf_dynptr_slice_rdwr(dptr, doff, NULL, size); 3387 if (likely(dst_slice)) 3388 return str_copy_fn(dst_slice, unsafe_src, size, tsk); 3389 3390 dst = (struct bpf_dynptr_kern *)dptr; 3391 if (bpf_dynptr_check_off_len(dst, doff, size)) 3392 return -E2BIG; 3393 3394 for (off = 0; off < size; off += chunk_sz - 1) { 3395 chunk_sz = min_t(u32, sizeof(buf), size - off); 3396 /* Expect str_copy_fn to return count of copied bytes, including 3397 * zero terminator. Next iteration increment off by chunk_sz - 1 to 3398 * overwrite NUL. 3399 */ 3400 cnt = str_copy_fn(buf, unsafe_src + off, chunk_sz, tsk); 3401 if (cnt < 0) 3402 return cnt; 3403 err = __bpf_dynptr_write(dst, doff + off, buf, cnt, 0); 3404 if (err) 3405 return err; 3406 if (cnt < chunk_sz || chunk_sz == 1) /* we are done */ 3407 return off + cnt; 3408 } 3409 return off; 3410 } 3411 3412 static __always_inline int __bpf_dynptr_copy(const struct bpf_dynptr *dptr, u32 doff, 3413 u32 size, const void *unsafe_src, 3414 copy_fn_t copy_fn, struct task_struct *tsk) 3415 { 3416 struct bpf_dynptr_kern *dst; 3417 void *dst_slice; 3418 char buf[256]; 3419 u32 off, chunk_sz; 3420 int err; 3421 3422 dst_slice = bpf_dynptr_slice_rdwr(dptr, doff, NULL, size); 3423 if (likely(dst_slice)) 3424 return copy_fn(dst_slice, unsafe_src, size, tsk); 3425 3426 dst = (struct bpf_dynptr_kern *)dptr; 3427 if (bpf_dynptr_check_off_len(dst, doff, size)) 3428 return -E2BIG; 3429 3430 for (off = 0; off < size; off += chunk_sz) { 3431 chunk_sz = min_t(u32, sizeof(buf), size - off); 3432 err = copy_fn(buf, unsafe_src + off, chunk_sz, tsk); 3433 if (err) 3434 return err; 3435 err = __bpf_dynptr_write(dst, doff + off, buf, chunk_sz, 0); 3436 if (err) 3437 return err; 3438 } 3439 return 0; 3440 } 3441 3442 static __always_inline int copy_user_data_nofault(void *dst, const void *unsafe_src, 3443 u32 size, struct task_struct *tsk) 3444 { 3445 return copy_from_user_nofault(dst, (const void __user *)unsafe_src, size); 3446 } 3447 3448 static __always_inline int copy_user_data_sleepable(void *dst, const void *unsafe_src, 3449 u32 size, struct task_struct *tsk) 3450 { 3451 int ret; 3452 3453 if (!tsk) { /* Read from the current task */ 3454 ret = copy_from_user(dst, (const void __user *)unsafe_src, size); 3455 if (ret) 3456 return -EFAULT; 3457 return 0; 3458 } 3459 3460 ret = access_process_vm(tsk, (unsigned long)unsafe_src, dst, size, 0); 3461 if (ret != size) 3462 return -EFAULT; 3463 return 0; 3464 } 3465 3466 static __always_inline int copy_kernel_data_nofault(void *dst, const void *unsafe_src, 3467 u32 size, struct task_struct *tsk) 3468 { 3469 return copy_from_kernel_nofault(dst, unsafe_src, size); 3470 } 3471 3472 static __always_inline int copy_user_str_nofault(void *dst, const void *unsafe_src, 3473 u32 size, struct task_struct *tsk) 3474 { 3475 return strncpy_from_user_nofault(dst, (const void __user *)unsafe_src, size); 3476 } 3477 3478 static __always_inline int copy_user_str_sleepable(void *dst, const void *unsafe_src, 3479 u32 size, struct task_struct *tsk) 3480 { 3481 int ret; 3482 3483 if (unlikely(size == 0)) 3484 return 0; 3485 3486 if (tsk) { 3487 ret = copy_remote_vm_str(tsk, (unsigned long)unsafe_src, dst, size, 0); 3488 } else { 3489 ret = strncpy_from_user(dst, (const void __user *)unsafe_src, size - 1); 3490 /* strncpy_from_user does not guarantee NUL termination */ 3491 if (ret >= 0) 3492 ((char *)dst)[ret] = '\0'; 3493 } 3494 3495 if (ret < 0) 3496 return ret; 3497 return ret + 1; 3498 } 3499 3500 static __always_inline int copy_kernel_str_nofault(void *dst, const void *unsafe_src, 3501 u32 size, struct task_struct *tsk) 3502 { 3503 return strncpy_from_kernel_nofault(dst, unsafe_src, size); 3504 } 3505 3506 __bpf_kfunc_start_defs(); 3507 3508 __bpf_kfunc int bpf_send_signal_task(struct task_struct *task, int sig, enum pid_type type, 3509 u64 value) 3510 { 3511 if (type != PIDTYPE_PID && type != PIDTYPE_TGID) 3512 return -EINVAL; 3513 3514 return bpf_send_signal_common(sig, type, task, value); 3515 } 3516 3517 __bpf_kfunc int bpf_probe_read_user_dynptr(struct bpf_dynptr *dptr, u32 off, 3518 u32 size, const void __user *unsafe_ptr__ign) 3519 { 3520 return __bpf_dynptr_copy(dptr, off, size, (const void *)unsafe_ptr__ign, 3521 copy_user_data_nofault, NULL); 3522 } 3523 3524 __bpf_kfunc int bpf_probe_read_kernel_dynptr(struct bpf_dynptr *dptr, u32 off, 3525 u32 size, const void *unsafe_ptr__ign) 3526 { 3527 return __bpf_dynptr_copy(dptr, off, size, unsafe_ptr__ign, 3528 copy_kernel_data_nofault, NULL); 3529 } 3530 3531 __bpf_kfunc int bpf_probe_read_user_str_dynptr(struct bpf_dynptr *dptr, u32 off, 3532 u32 size, const void __user *unsafe_ptr__ign) 3533 { 3534 return __bpf_dynptr_copy_str(dptr, off, size, (const void *)unsafe_ptr__ign, 3535 copy_user_str_nofault, NULL); 3536 } 3537 3538 __bpf_kfunc int bpf_probe_read_kernel_str_dynptr(struct bpf_dynptr *dptr, u32 off, 3539 u32 size, const void *unsafe_ptr__ign) 3540 { 3541 return __bpf_dynptr_copy_str(dptr, off, size, unsafe_ptr__ign, 3542 copy_kernel_str_nofault, NULL); 3543 } 3544 3545 __bpf_kfunc int bpf_copy_from_user_dynptr(struct bpf_dynptr *dptr, u32 off, 3546 u32 size, const void __user *unsafe_ptr__ign) 3547 { 3548 return __bpf_dynptr_copy(dptr, off, size, (const void *)unsafe_ptr__ign, 3549 copy_user_data_sleepable, NULL); 3550 } 3551 3552 __bpf_kfunc int bpf_copy_from_user_str_dynptr(struct bpf_dynptr *dptr, u32 off, 3553 u32 size, const void __user *unsafe_ptr__ign) 3554 { 3555 return __bpf_dynptr_copy_str(dptr, off, size, (const void *)unsafe_ptr__ign, 3556 copy_user_str_sleepable, NULL); 3557 } 3558 3559 __bpf_kfunc int bpf_copy_from_user_task_dynptr(struct bpf_dynptr *dptr, u32 off, 3560 u32 size, const void __user *unsafe_ptr__ign, 3561 struct task_struct *tsk) 3562 { 3563 return __bpf_dynptr_copy(dptr, off, size, (const void *)unsafe_ptr__ign, 3564 copy_user_data_sleepable, tsk); 3565 } 3566 3567 __bpf_kfunc int bpf_copy_from_user_task_str_dynptr(struct bpf_dynptr *dptr, u32 off, 3568 u32 size, const void __user *unsafe_ptr__ign, 3569 struct task_struct *tsk) 3570 { 3571 return __bpf_dynptr_copy_str(dptr, off, size, (const void *)unsafe_ptr__ign, 3572 copy_user_str_sleepable, tsk); 3573 } 3574 3575 __bpf_kfunc_end_defs(); 3576