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 (type != BPF_READ) 1342 return false; 1343 if (off % size != 0) 1344 return false; 1345 /* 1346 * Assertion for 32 bit to make sure last 8 byte access 1347 * (BPF_DW) to the last 4 byte member is disallowed. 1348 */ 1349 if (off + size > sizeof(struct pt_regs)) 1350 return false; 1351 1352 return true; 1353 } 1354 1355 const struct bpf_verifier_ops kprobe_verifier_ops = { 1356 .get_func_proto = kprobe_prog_func_proto, 1357 .is_valid_access = kprobe_prog_is_valid_access, 1358 }; 1359 1360 const struct bpf_prog_ops kprobe_prog_ops = { 1361 }; 1362 1363 BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map, 1364 u64, flags, void *, data, u64, size) 1365 { 1366 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1367 1368 /* 1369 * r1 points to perf tracepoint buffer where first 8 bytes are hidden 1370 * from bpf program and contain a pointer to 'struct pt_regs'. Fetch it 1371 * from there and call the same bpf_perf_event_output() helper inline. 1372 */ 1373 return ____bpf_perf_event_output(regs, map, flags, data, size); 1374 } 1375 1376 static const struct bpf_func_proto bpf_perf_event_output_proto_tp = { 1377 .func = bpf_perf_event_output_tp, 1378 .gpl_only = true, 1379 .ret_type = RET_INTEGER, 1380 .arg1_type = ARG_PTR_TO_CTX, 1381 .arg2_type = ARG_CONST_MAP_PTR, 1382 .arg3_type = ARG_ANYTHING, 1383 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1384 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 1385 }; 1386 1387 BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map, 1388 u64, flags) 1389 { 1390 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1391 1392 /* 1393 * Same comment as in bpf_perf_event_output_tp(), only that this time 1394 * the other helper's function body cannot be inlined due to being 1395 * external, thus we need to call raw helper function. 1396 */ 1397 return bpf_get_stackid((unsigned long) regs, (unsigned long) map, 1398 flags, 0, 0); 1399 } 1400 1401 static const struct bpf_func_proto bpf_get_stackid_proto_tp = { 1402 .func = bpf_get_stackid_tp, 1403 .gpl_only = true, 1404 .ret_type = RET_INTEGER, 1405 .arg1_type = ARG_PTR_TO_CTX, 1406 .arg2_type = ARG_CONST_MAP_PTR, 1407 .arg3_type = ARG_ANYTHING, 1408 }; 1409 1410 BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size, 1411 u64, flags) 1412 { 1413 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1414 1415 return bpf_get_stack((unsigned long) regs, (unsigned long) buf, 1416 (unsigned long) size, flags, 0); 1417 } 1418 1419 static const struct bpf_func_proto bpf_get_stack_proto_tp = { 1420 .func = bpf_get_stack_tp, 1421 .gpl_only = true, 1422 .ret_type = RET_INTEGER, 1423 .arg1_type = ARG_PTR_TO_CTX, 1424 .arg2_type = ARG_PTR_TO_UNINIT_MEM, 1425 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1426 .arg4_type = ARG_ANYTHING, 1427 }; 1428 1429 static const struct bpf_func_proto * 1430 tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1431 { 1432 switch (func_id) { 1433 case BPF_FUNC_perf_event_output: 1434 return &bpf_perf_event_output_proto_tp; 1435 case BPF_FUNC_get_stackid: 1436 return &bpf_get_stackid_proto_tp; 1437 case BPF_FUNC_get_stack: 1438 return &bpf_get_stack_proto_tp; 1439 case BPF_FUNC_get_attach_cookie: 1440 return &bpf_get_attach_cookie_proto_trace; 1441 default: 1442 return bpf_tracing_func_proto(func_id, prog); 1443 } 1444 } 1445 1446 static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type, 1447 const struct bpf_prog *prog, 1448 struct bpf_insn_access_aux *info) 1449 { 1450 if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE) 1451 return false; 1452 if (type != BPF_READ) 1453 return false; 1454 if (off % size != 0) 1455 return false; 1456 1457 BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(__u64)); 1458 return true; 1459 } 1460 1461 const struct bpf_verifier_ops tracepoint_verifier_ops = { 1462 .get_func_proto = tp_prog_func_proto, 1463 .is_valid_access = tp_prog_is_valid_access, 1464 }; 1465 1466 const struct bpf_prog_ops tracepoint_prog_ops = { 1467 }; 1468 1469 BPF_CALL_3(bpf_perf_prog_read_value, struct bpf_perf_event_data_kern *, ctx, 1470 struct bpf_perf_event_value *, buf, u32, size) 1471 { 1472 int err = -EINVAL; 1473 1474 if (unlikely(size != sizeof(struct bpf_perf_event_value))) 1475 goto clear; 1476 err = perf_event_read_local(ctx->event, &buf->counter, &buf->enabled, 1477 &buf->running); 1478 if (unlikely(err)) 1479 goto clear; 1480 return 0; 1481 clear: 1482 memset(buf, 0, size); 1483 return err; 1484 } 1485 1486 static const struct bpf_func_proto bpf_perf_prog_read_value_proto = { 1487 .func = bpf_perf_prog_read_value, 1488 .gpl_only = true, 1489 .ret_type = RET_INTEGER, 1490 .arg1_type = ARG_PTR_TO_CTX, 1491 .arg2_type = ARG_PTR_TO_UNINIT_MEM, 1492 .arg3_type = ARG_CONST_SIZE, 1493 }; 1494 1495 BPF_CALL_4(bpf_read_branch_records, struct bpf_perf_event_data_kern *, ctx, 1496 void *, buf, u32, size, u64, flags) 1497 { 1498 static const u32 br_entry_size = sizeof(struct perf_branch_entry); 1499 struct perf_branch_stack *br_stack = ctx->data->br_stack; 1500 u32 to_copy; 1501 1502 if (unlikely(flags & ~BPF_F_GET_BRANCH_RECORDS_SIZE)) 1503 return -EINVAL; 1504 1505 if (unlikely(!(ctx->data->sample_flags & PERF_SAMPLE_BRANCH_STACK))) 1506 return -ENOENT; 1507 1508 if (unlikely(!br_stack)) 1509 return -ENOENT; 1510 1511 if (flags & BPF_F_GET_BRANCH_RECORDS_SIZE) 1512 return br_stack->nr * br_entry_size; 1513 1514 if (!buf || (size % br_entry_size != 0)) 1515 return -EINVAL; 1516 1517 to_copy = min_t(u32, br_stack->nr * br_entry_size, size); 1518 memcpy(buf, br_stack->entries, to_copy); 1519 1520 return to_copy; 1521 } 1522 1523 static const struct bpf_func_proto bpf_read_branch_records_proto = { 1524 .func = bpf_read_branch_records, 1525 .gpl_only = true, 1526 .ret_type = RET_INTEGER, 1527 .arg1_type = ARG_PTR_TO_CTX, 1528 .arg2_type = ARG_PTR_TO_MEM_OR_NULL, 1529 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1530 .arg4_type = ARG_ANYTHING, 1531 }; 1532 1533 static const struct bpf_func_proto * 1534 pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1535 { 1536 switch (func_id) { 1537 case BPF_FUNC_perf_event_output: 1538 return &bpf_perf_event_output_proto_tp; 1539 case BPF_FUNC_get_stackid: 1540 return &bpf_get_stackid_proto_pe; 1541 case BPF_FUNC_get_stack: 1542 return &bpf_get_stack_proto_pe; 1543 case BPF_FUNC_perf_prog_read_value: 1544 return &bpf_perf_prog_read_value_proto; 1545 case BPF_FUNC_read_branch_records: 1546 return &bpf_read_branch_records_proto; 1547 case BPF_FUNC_get_attach_cookie: 1548 return &bpf_get_attach_cookie_proto_pe; 1549 default: 1550 return bpf_tracing_func_proto(func_id, prog); 1551 } 1552 } 1553 1554 /* 1555 * bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp 1556 * to avoid potential recursive reuse issue when/if tracepoints are added 1557 * inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack. 1558 * 1559 * Since raw tracepoints run despite bpf_prog_active, support concurrent usage 1560 * in normal, irq, and nmi context. 1561 */ 1562 struct bpf_raw_tp_regs { 1563 struct pt_regs regs[3]; 1564 }; 1565 static DEFINE_PER_CPU(struct bpf_raw_tp_regs, bpf_raw_tp_regs); 1566 static DEFINE_PER_CPU(int, bpf_raw_tp_nest_level); 1567 static struct pt_regs *get_bpf_raw_tp_regs(void) 1568 { 1569 struct bpf_raw_tp_regs *tp_regs = this_cpu_ptr(&bpf_raw_tp_regs); 1570 int nest_level = this_cpu_inc_return(bpf_raw_tp_nest_level); 1571 1572 if (nest_level > ARRAY_SIZE(tp_regs->regs)) { 1573 this_cpu_dec(bpf_raw_tp_nest_level); 1574 return ERR_PTR(-EBUSY); 1575 } 1576 1577 return &tp_regs->regs[nest_level - 1]; 1578 } 1579 1580 static void put_bpf_raw_tp_regs(void) 1581 { 1582 this_cpu_dec(bpf_raw_tp_nest_level); 1583 } 1584 1585 BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args, 1586 struct bpf_map *, map, u64, flags, void *, data, u64, size) 1587 { 1588 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1589 int ret; 1590 1591 if (IS_ERR(regs)) 1592 return PTR_ERR(regs); 1593 1594 perf_fetch_caller_regs(regs); 1595 ret = ____bpf_perf_event_output(regs, map, flags, data, size); 1596 1597 put_bpf_raw_tp_regs(); 1598 return ret; 1599 } 1600 1601 static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = { 1602 .func = bpf_perf_event_output_raw_tp, 1603 .gpl_only = true, 1604 .ret_type = RET_INTEGER, 1605 .arg1_type = ARG_PTR_TO_CTX, 1606 .arg2_type = ARG_CONST_MAP_PTR, 1607 .arg3_type = ARG_ANYTHING, 1608 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1609 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 1610 }; 1611 1612 extern const struct bpf_func_proto bpf_skb_output_proto; 1613 extern const struct bpf_func_proto bpf_xdp_output_proto; 1614 extern const struct bpf_func_proto bpf_xdp_get_buff_len_trace_proto; 1615 1616 BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args, 1617 struct bpf_map *, map, u64, flags) 1618 { 1619 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1620 int ret; 1621 1622 if (IS_ERR(regs)) 1623 return PTR_ERR(regs); 1624 1625 perf_fetch_caller_regs(regs); 1626 /* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */ 1627 ret = bpf_get_stackid((unsigned long) regs, (unsigned long) map, 1628 flags, 0, 0); 1629 put_bpf_raw_tp_regs(); 1630 return ret; 1631 } 1632 1633 static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = { 1634 .func = bpf_get_stackid_raw_tp, 1635 .gpl_only = true, 1636 .ret_type = RET_INTEGER, 1637 .arg1_type = ARG_PTR_TO_CTX, 1638 .arg2_type = ARG_CONST_MAP_PTR, 1639 .arg3_type = ARG_ANYTHING, 1640 }; 1641 1642 BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args, 1643 void *, buf, u32, size, u64, flags) 1644 { 1645 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1646 int ret; 1647 1648 if (IS_ERR(regs)) 1649 return PTR_ERR(regs); 1650 1651 perf_fetch_caller_regs(regs); 1652 ret = bpf_get_stack((unsigned long) regs, (unsigned long) buf, 1653 (unsigned long) size, flags, 0); 1654 put_bpf_raw_tp_regs(); 1655 return ret; 1656 } 1657 1658 static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = { 1659 .func = bpf_get_stack_raw_tp, 1660 .gpl_only = true, 1661 .ret_type = RET_INTEGER, 1662 .arg1_type = ARG_PTR_TO_CTX, 1663 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1664 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1665 .arg4_type = ARG_ANYTHING, 1666 }; 1667 1668 static const struct bpf_func_proto * 1669 raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1670 { 1671 switch (func_id) { 1672 case BPF_FUNC_perf_event_output: 1673 return &bpf_perf_event_output_proto_raw_tp; 1674 case BPF_FUNC_get_stackid: 1675 return &bpf_get_stackid_proto_raw_tp; 1676 case BPF_FUNC_get_stack: 1677 return &bpf_get_stack_proto_raw_tp; 1678 case BPF_FUNC_get_attach_cookie: 1679 return &bpf_get_attach_cookie_proto_tracing; 1680 default: 1681 return bpf_tracing_func_proto(func_id, prog); 1682 } 1683 } 1684 1685 const struct bpf_func_proto * 1686 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1687 { 1688 const struct bpf_func_proto *fn; 1689 1690 switch (func_id) { 1691 #ifdef CONFIG_NET 1692 case BPF_FUNC_skb_output: 1693 return &bpf_skb_output_proto; 1694 case BPF_FUNC_xdp_output: 1695 return &bpf_xdp_output_proto; 1696 case BPF_FUNC_skc_to_tcp6_sock: 1697 return &bpf_skc_to_tcp6_sock_proto; 1698 case BPF_FUNC_skc_to_tcp_sock: 1699 return &bpf_skc_to_tcp_sock_proto; 1700 case BPF_FUNC_skc_to_tcp_timewait_sock: 1701 return &bpf_skc_to_tcp_timewait_sock_proto; 1702 case BPF_FUNC_skc_to_tcp_request_sock: 1703 return &bpf_skc_to_tcp_request_sock_proto; 1704 case BPF_FUNC_skc_to_udp6_sock: 1705 return &bpf_skc_to_udp6_sock_proto; 1706 case BPF_FUNC_skc_to_unix_sock: 1707 return &bpf_skc_to_unix_sock_proto; 1708 case BPF_FUNC_skc_to_mptcp_sock: 1709 return &bpf_skc_to_mptcp_sock_proto; 1710 case BPF_FUNC_sk_storage_get: 1711 return &bpf_sk_storage_get_tracing_proto; 1712 case BPF_FUNC_sk_storage_delete: 1713 return &bpf_sk_storage_delete_tracing_proto; 1714 case BPF_FUNC_sock_from_file: 1715 return &bpf_sock_from_file_proto; 1716 case BPF_FUNC_get_socket_cookie: 1717 return &bpf_get_socket_ptr_cookie_proto; 1718 case BPF_FUNC_xdp_get_buff_len: 1719 return &bpf_xdp_get_buff_len_trace_proto; 1720 #endif 1721 case BPF_FUNC_seq_printf: 1722 return prog->expected_attach_type == BPF_TRACE_ITER ? 1723 &bpf_seq_printf_proto : 1724 NULL; 1725 case BPF_FUNC_seq_write: 1726 return prog->expected_attach_type == BPF_TRACE_ITER ? 1727 &bpf_seq_write_proto : 1728 NULL; 1729 case BPF_FUNC_seq_printf_btf: 1730 return prog->expected_attach_type == BPF_TRACE_ITER ? 1731 &bpf_seq_printf_btf_proto : 1732 NULL; 1733 case BPF_FUNC_d_path: 1734 return &bpf_d_path_proto; 1735 case BPF_FUNC_get_func_arg: 1736 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_proto : NULL; 1737 case BPF_FUNC_get_func_ret: 1738 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_ret_proto : NULL; 1739 case BPF_FUNC_get_func_arg_cnt: 1740 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_cnt_proto : NULL; 1741 case BPF_FUNC_get_attach_cookie: 1742 if (prog->type == BPF_PROG_TYPE_TRACING && 1743 prog->expected_attach_type == BPF_TRACE_RAW_TP) 1744 return &bpf_get_attach_cookie_proto_tracing; 1745 return bpf_prog_has_trampoline(prog) ? &bpf_get_attach_cookie_proto_tracing : NULL; 1746 default: 1747 fn = raw_tp_prog_func_proto(func_id, prog); 1748 if (!fn && prog->expected_attach_type == BPF_TRACE_ITER) 1749 fn = bpf_iter_get_func_proto(func_id, prog); 1750 return fn; 1751 } 1752 } 1753 1754 static bool raw_tp_prog_is_valid_access(int off, int size, 1755 enum bpf_access_type type, 1756 const struct bpf_prog *prog, 1757 struct bpf_insn_access_aux *info) 1758 { 1759 return bpf_tracing_ctx_access(off, size, type); 1760 } 1761 1762 static bool tracing_prog_is_valid_access(int off, int size, 1763 enum bpf_access_type type, 1764 const struct bpf_prog *prog, 1765 struct bpf_insn_access_aux *info) 1766 { 1767 return bpf_tracing_btf_ctx_access(off, size, type, prog, info); 1768 } 1769 1770 int __weak bpf_prog_test_run_tracing(struct bpf_prog *prog, 1771 const union bpf_attr *kattr, 1772 union bpf_attr __user *uattr) 1773 { 1774 return -ENOTSUPP; 1775 } 1776 1777 const struct bpf_verifier_ops raw_tracepoint_verifier_ops = { 1778 .get_func_proto = raw_tp_prog_func_proto, 1779 .is_valid_access = raw_tp_prog_is_valid_access, 1780 }; 1781 1782 const struct bpf_prog_ops raw_tracepoint_prog_ops = { 1783 #ifdef CONFIG_NET 1784 .test_run = bpf_prog_test_run_raw_tp, 1785 #endif 1786 }; 1787 1788 const struct bpf_verifier_ops tracing_verifier_ops = { 1789 .get_func_proto = tracing_prog_func_proto, 1790 .is_valid_access = tracing_prog_is_valid_access, 1791 }; 1792 1793 const struct bpf_prog_ops tracing_prog_ops = { 1794 .test_run = bpf_prog_test_run_tracing, 1795 }; 1796 1797 static bool raw_tp_writable_prog_is_valid_access(int off, int size, 1798 enum bpf_access_type type, 1799 const struct bpf_prog *prog, 1800 struct bpf_insn_access_aux *info) 1801 { 1802 if (off == 0) { 1803 if (size != sizeof(u64) || type != BPF_READ) 1804 return false; 1805 info->reg_type = PTR_TO_TP_BUFFER; 1806 } 1807 return raw_tp_prog_is_valid_access(off, size, type, prog, info); 1808 } 1809 1810 const struct bpf_verifier_ops raw_tracepoint_writable_verifier_ops = { 1811 .get_func_proto = raw_tp_prog_func_proto, 1812 .is_valid_access = raw_tp_writable_prog_is_valid_access, 1813 }; 1814 1815 const struct bpf_prog_ops raw_tracepoint_writable_prog_ops = { 1816 }; 1817 1818 static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type, 1819 const struct bpf_prog *prog, 1820 struct bpf_insn_access_aux *info) 1821 { 1822 const int size_u64 = sizeof(u64); 1823 1824 if (off < 0 || off >= sizeof(struct bpf_perf_event_data)) 1825 return false; 1826 if (type != BPF_READ) 1827 return false; 1828 if (off % size != 0) { 1829 if (sizeof(unsigned long) != 4) 1830 return false; 1831 if (size != 8) 1832 return false; 1833 if (off % size != 4) 1834 return false; 1835 } 1836 1837 switch (off) { 1838 case bpf_ctx_range(struct bpf_perf_event_data, sample_period): 1839 bpf_ctx_record_field_size(info, size_u64); 1840 if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) 1841 return false; 1842 break; 1843 case bpf_ctx_range(struct bpf_perf_event_data, addr): 1844 bpf_ctx_record_field_size(info, size_u64); 1845 if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) 1846 return false; 1847 break; 1848 default: 1849 if (size != sizeof(long)) 1850 return false; 1851 } 1852 1853 return true; 1854 } 1855 1856 static u32 pe_prog_convert_ctx_access(enum bpf_access_type type, 1857 const struct bpf_insn *si, 1858 struct bpf_insn *insn_buf, 1859 struct bpf_prog *prog, u32 *target_size) 1860 { 1861 struct bpf_insn *insn = insn_buf; 1862 1863 switch (si->off) { 1864 case offsetof(struct bpf_perf_event_data, sample_period): 1865 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 1866 data), si->dst_reg, si->src_reg, 1867 offsetof(struct bpf_perf_event_data_kern, data)); 1868 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, 1869 bpf_target_off(struct perf_sample_data, period, 8, 1870 target_size)); 1871 break; 1872 case offsetof(struct bpf_perf_event_data, addr): 1873 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 1874 data), si->dst_reg, si->src_reg, 1875 offsetof(struct bpf_perf_event_data_kern, data)); 1876 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, 1877 bpf_target_off(struct perf_sample_data, addr, 8, 1878 target_size)); 1879 break; 1880 default: 1881 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 1882 regs), si->dst_reg, si->src_reg, 1883 offsetof(struct bpf_perf_event_data_kern, regs)); 1884 *insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg, 1885 si->off); 1886 break; 1887 } 1888 1889 return insn - insn_buf; 1890 } 1891 1892 const struct bpf_verifier_ops perf_event_verifier_ops = { 1893 .get_func_proto = pe_prog_func_proto, 1894 .is_valid_access = pe_prog_is_valid_access, 1895 .convert_ctx_access = pe_prog_convert_ctx_access, 1896 }; 1897 1898 const struct bpf_prog_ops perf_event_prog_ops = { 1899 }; 1900 1901 static DEFINE_MUTEX(bpf_event_mutex); 1902 1903 #define BPF_TRACE_MAX_PROGS 64 1904 1905 int perf_event_attach_bpf_prog(struct perf_event *event, 1906 struct bpf_prog *prog, 1907 u64 bpf_cookie) 1908 { 1909 struct bpf_prog_array *old_array; 1910 struct bpf_prog_array *new_array; 1911 int ret = -EEXIST; 1912 1913 /* 1914 * Kprobe override only works if they are on the function entry, 1915 * and only if they are on the opt-in list. 1916 */ 1917 if (prog->kprobe_override && 1918 (!trace_kprobe_on_func_entry(event->tp_event) || 1919 !trace_kprobe_error_injectable(event->tp_event))) 1920 return -EINVAL; 1921 1922 mutex_lock(&bpf_event_mutex); 1923 1924 if (event->prog) 1925 goto unlock; 1926 1927 old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); 1928 if (old_array && 1929 bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) { 1930 ret = -E2BIG; 1931 goto unlock; 1932 } 1933 1934 ret = bpf_prog_array_copy(old_array, NULL, prog, bpf_cookie, &new_array); 1935 if (ret < 0) 1936 goto unlock; 1937 1938 /* set the new array to event->tp_event and set event->prog */ 1939 event->prog = prog; 1940 event->bpf_cookie = bpf_cookie; 1941 rcu_assign_pointer(event->tp_event->prog_array, new_array); 1942 bpf_prog_array_free_sleepable(old_array); 1943 1944 unlock: 1945 mutex_unlock(&bpf_event_mutex); 1946 return ret; 1947 } 1948 1949 void perf_event_detach_bpf_prog(struct perf_event *event) 1950 { 1951 struct bpf_prog_array *old_array; 1952 struct bpf_prog_array *new_array; 1953 struct bpf_prog *prog = NULL; 1954 int ret; 1955 1956 mutex_lock(&bpf_event_mutex); 1957 1958 if (!event->prog) 1959 goto unlock; 1960 1961 old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); 1962 if (!old_array) 1963 goto put; 1964 1965 ret = bpf_prog_array_copy(old_array, event->prog, NULL, 0, &new_array); 1966 if (ret < 0) { 1967 bpf_prog_array_delete_safe(old_array, event->prog); 1968 } else { 1969 rcu_assign_pointer(event->tp_event->prog_array, new_array); 1970 bpf_prog_array_free_sleepable(old_array); 1971 } 1972 1973 put: 1974 prog = event->prog; 1975 event->prog = NULL; 1976 1977 unlock: 1978 mutex_unlock(&bpf_event_mutex); 1979 1980 if (prog) { 1981 /* 1982 * It could be that the bpf_prog is not sleepable (and will be freed 1983 * via normal RCU), but is called from a point that supports sleepable 1984 * programs and uses tasks-trace-RCU. 1985 */ 1986 synchronize_rcu_tasks_trace(); 1987 1988 bpf_prog_put(prog); 1989 } 1990 } 1991 1992 int perf_event_query_prog_array(struct perf_event *event, void __user *info) 1993 { 1994 struct perf_event_query_bpf __user *uquery = info; 1995 struct perf_event_query_bpf query = {}; 1996 struct bpf_prog_array *progs; 1997 u32 *ids, prog_cnt, ids_len; 1998 int ret; 1999 2000 if (!perfmon_capable()) 2001 return -EPERM; 2002 if (event->attr.type != PERF_TYPE_TRACEPOINT) 2003 return -EINVAL; 2004 if (copy_from_user(&query, uquery, sizeof(query))) 2005 return -EFAULT; 2006 2007 ids_len = query.ids_len; 2008 if (ids_len > BPF_TRACE_MAX_PROGS) 2009 return -E2BIG; 2010 ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN); 2011 if (!ids) 2012 return -ENOMEM; 2013 /* 2014 * The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which 2015 * is required when user only wants to check for uquery->prog_cnt. 2016 * There is no need to check for it since the case is handled 2017 * gracefully in bpf_prog_array_copy_info. 2018 */ 2019 2020 mutex_lock(&bpf_event_mutex); 2021 progs = bpf_event_rcu_dereference(event->tp_event->prog_array); 2022 ret = bpf_prog_array_copy_info(progs, ids, ids_len, &prog_cnt); 2023 mutex_unlock(&bpf_event_mutex); 2024 2025 if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) || 2026 copy_to_user(uquery->ids, ids, ids_len * sizeof(u32))) 2027 ret = -EFAULT; 2028 2029 kfree(ids); 2030 return ret; 2031 } 2032 2033 extern struct bpf_raw_event_map __start__bpf_raw_tp[]; 2034 extern struct bpf_raw_event_map __stop__bpf_raw_tp[]; 2035 2036 struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name) 2037 { 2038 struct bpf_raw_event_map *btp = __start__bpf_raw_tp; 2039 2040 for (; btp < __stop__bpf_raw_tp; btp++) { 2041 if (!strcmp(btp->tp->name, name)) 2042 return btp; 2043 } 2044 2045 return bpf_get_raw_tracepoint_module(name); 2046 } 2047 2048 void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp) 2049 { 2050 struct module *mod; 2051 2052 guard(rcu)(); 2053 mod = __module_address((unsigned long)btp); 2054 module_put(mod); 2055 } 2056 2057 static __always_inline 2058 void __bpf_trace_run(struct bpf_raw_tp_link *link, u64 *args) 2059 { 2060 struct bpf_prog *prog = link->link.prog; 2061 struct bpf_run_ctx *old_run_ctx; 2062 struct bpf_trace_run_ctx run_ctx; 2063 2064 cant_sleep(); 2065 if (unlikely(this_cpu_inc_return(*(prog->active)) != 1)) { 2066 bpf_prog_inc_misses_counter(prog); 2067 goto out; 2068 } 2069 2070 run_ctx.bpf_cookie = link->cookie; 2071 old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx); 2072 2073 rcu_read_lock(); 2074 (void) bpf_prog_run(prog, args); 2075 rcu_read_unlock(); 2076 2077 bpf_reset_run_ctx(old_run_ctx); 2078 out: 2079 this_cpu_dec(*(prog->active)); 2080 } 2081 2082 #define UNPACK(...) __VA_ARGS__ 2083 #define REPEAT_1(FN, DL, X, ...) FN(X) 2084 #define REPEAT_2(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__) 2085 #define REPEAT_3(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_2(FN, DL, __VA_ARGS__) 2086 #define REPEAT_4(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_3(FN, DL, __VA_ARGS__) 2087 #define REPEAT_5(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_4(FN, DL, __VA_ARGS__) 2088 #define REPEAT_6(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_5(FN, DL, __VA_ARGS__) 2089 #define REPEAT_7(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_6(FN, DL, __VA_ARGS__) 2090 #define REPEAT_8(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_7(FN, DL, __VA_ARGS__) 2091 #define REPEAT_9(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_8(FN, DL, __VA_ARGS__) 2092 #define REPEAT_10(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_9(FN, DL, __VA_ARGS__) 2093 #define REPEAT_11(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_10(FN, DL, __VA_ARGS__) 2094 #define REPEAT_12(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_11(FN, DL, __VA_ARGS__) 2095 #define REPEAT(X, FN, DL, ...) REPEAT_##X(FN, DL, __VA_ARGS__) 2096 2097 #define SARG(X) u64 arg##X 2098 #define COPY(X) args[X] = arg##X 2099 2100 #define __DL_COM (,) 2101 #define __DL_SEM (;) 2102 2103 #define __SEQ_0_11 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 2104 2105 #define BPF_TRACE_DEFN_x(x) \ 2106 void bpf_trace_run##x(struct bpf_raw_tp_link *link, \ 2107 REPEAT(x, SARG, __DL_COM, __SEQ_0_11)) \ 2108 { \ 2109 u64 args[x]; \ 2110 REPEAT(x, COPY, __DL_SEM, __SEQ_0_11); \ 2111 __bpf_trace_run(link, args); \ 2112 } \ 2113 EXPORT_SYMBOL_GPL(bpf_trace_run##x) 2114 BPF_TRACE_DEFN_x(1); 2115 BPF_TRACE_DEFN_x(2); 2116 BPF_TRACE_DEFN_x(3); 2117 BPF_TRACE_DEFN_x(4); 2118 BPF_TRACE_DEFN_x(5); 2119 BPF_TRACE_DEFN_x(6); 2120 BPF_TRACE_DEFN_x(7); 2121 BPF_TRACE_DEFN_x(8); 2122 BPF_TRACE_DEFN_x(9); 2123 BPF_TRACE_DEFN_x(10); 2124 BPF_TRACE_DEFN_x(11); 2125 BPF_TRACE_DEFN_x(12); 2126 2127 int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_raw_tp_link *link) 2128 { 2129 struct tracepoint *tp = btp->tp; 2130 struct bpf_prog *prog = link->link.prog; 2131 2132 /* 2133 * check that program doesn't access arguments beyond what's 2134 * available in this tracepoint 2135 */ 2136 if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64)) 2137 return -EINVAL; 2138 2139 if (prog->aux->max_tp_access > btp->writable_size) 2140 return -EINVAL; 2141 2142 return tracepoint_probe_register_may_exist(tp, (void *)btp->bpf_func, link); 2143 } 2144 2145 int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_raw_tp_link *link) 2146 { 2147 return tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, link); 2148 } 2149 2150 int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id, 2151 u32 *fd_type, const char **buf, 2152 u64 *probe_offset, u64 *probe_addr, 2153 unsigned long *missed) 2154 { 2155 bool is_tracepoint, is_syscall_tp; 2156 struct bpf_prog *prog; 2157 int flags, err = 0; 2158 2159 prog = event->prog; 2160 if (!prog) 2161 return -ENOENT; 2162 2163 /* not supporting BPF_PROG_TYPE_PERF_EVENT yet */ 2164 if (prog->type == BPF_PROG_TYPE_PERF_EVENT) 2165 return -EOPNOTSUPP; 2166 2167 *prog_id = prog->aux->id; 2168 flags = event->tp_event->flags; 2169 is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT; 2170 is_syscall_tp = is_syscall_trace_event(event->tp_event); 2171 2172 if (is_tracepoint || is_syscall_tp) { 2173 *buf = is_tracepoint ? event->tp_event->tp->name 2174 : event->tp_event->name; 2175 /* We allow NULL pointer for tracepoint */ 2176 if (fd_type) 2177 *fd_type = BPF_FD_TYPE_TRACEPOINT; 2178 if (probe_offset) 2179 *probe_offset = 0x0; 2180 if (probe_addr) 2181 *probe_addr = 0x0; 2182 } else { 2183 /* kprobe/uprobe */ 2184 err = -EOPNOTSUPP; 2185 #ifdef CONFIG_KPROBE_EVENTS 2186 if (flags & TRACE_EVENT_FL_KPROBE) 2187 err = bpf_get_kprobe_info(event, fd_type, buf, 2188 probe_offset, probe_addr, missed, 2189 event->attr.type == PERF_TYPE_TRACEPOINT); 2190 #endif 2191 #ifdef CONFIG_UPROBE_EVENTS 2192 if (flags & TRACE_EVENT_FL_UPROBE) 2193 err = bpf_get_uprobe_info(event, fd_type, buf, 2194 probe_offset, probe_addr, 2195 event->attr.type == PERF_TYPE_TRACEPOINT); 2196 #endif 2197 } 2198 2199 return err; 2200 } 2201 2202 static int __init send_signal_irq_work_init(void) 2203 { 2204 int cpu; 2205 struct send_signal_irq_work *work; 2206 2207 for_each_possible_cpu(cpu) { 2208 work = per_cpu_ptr(&send_signal_work, cpu); 2209 init_irq_work(&work->irq_work, do_bpf_send_signal); 2210 } 2211 return 0; 2212 } 2213 2214 subsys_initcall(send_signal_irq_work_init); 2215 2216 #ifdef CONFIG_MODULES 2217 static int bpf_event_notify(struct notifier_block *nb, unsigned long op, 2218 void *module) 2219 { 2220 struct bpf_trace_module *btm, *tmp; 2221 struct module *mod = module; 2222 int ret = 0; 2223 2224 if (mod->num_bpf_raw_events == 0 || 2225 (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING)) 2226 goto out; 2227 2228 mutex_lock(&bpf_module_mutex); 2229 2230 switch (op) { 2231 case MODULE_STATE_COMING: 2232 btm = kzalloc(sizeof(*btm), GFP_KERNEL); 2233 if (btm) { 2234 btm->module = module; 2235 list_add(&btm->list, &bpf_trace_modules); 2236 } else { 2237 ret = -ENOMEM; 2238 } 2239 break; 2240 case MODULE_STATE_GOING: 2241 list_for_each_entry_safe(btm, tmp, &bpf_trace_modules, list) { 2242 if (btm->module == module) { 2243 list_del(&btm->list); 2244 kfree(btm); 2245 break; 2246 } 2247 } 2248 break; 2249 } 2250 2251 mutex_unlock(&bpf_module_mutex); 2252 2253 out: 2254 return notifier_from_errno(ret); 2255 } 2256 2257 static struct notifier_block bpf_module_nb = { 2258 .notifier_call = bpf_event_notify, 2259 }; 2260 2261 static int __init bpf_event_init(void) 2262 { 2263 register_module_notifier(&bpf_module_nb); 2264 return 0; 2265 } 2266 2267 fs_initcall(bpf_event_init); 2268 #endif /* CONFIG_MODULES */ 2269 2270 struct bpf_session_run_ctx { 2271 struct bpf_run_ctx run_ctx; 2272 bool is_return; 2273 void *data; 2274 }; 2275 2276 #ifdef CONFIG_FPROBE 2277 struct bpf_kprobe_multi_link { 2278 struct bpf_link link; 2279 struct fprobe fp; 2280 unsigned long *addrs; 2281 u64 *cookies; 2282 u32 cnt; 2283 u32 mods_cnt; 2284 struct module **mods; 2285 }; 2286 2287 struct bpf_kprobe_multi_run_ctx { 2288 struct bpf_session_run_ctx session_ctx; 2289 struct bpf_kprobe_multi_link *link; 2290 unsigned long entry_ip; 2291 }; 2292 2293 struct user_syms { 2294 const char **syms; 2295 char *buf; 2296 }; 2297 2298 #ifndef CONFIG_HAVE_FTRACE_REGS_HAVING_PT_REGS 2299 static DEFINE_PER_CPU(struct pt_regs, bpf_kprobe_multi_pt_regs); 2300 #define bpf_kprobe_multi_pt_regs_ptr() this_cpu_ptr(&bpf_kprobe_multi_pt_regs) 2301 #else 2302 #define bpf_kprobe_multi_pt_regs_ptr() (NULL) 2303 #endif 2304 2305 static unsigned long ftrace_get_entry_ip(unsigned long fentry_ip) 2306 { 2307 unsigned long ip = ftrace_get_symaddr(fentry_ip); 2308 2309 return ip ? : fentry_ip; 2310 } 2311 2312 static int copy_user_syms(struct user_syms *us, unsigned long __user *usyms, u32 cnt) 2313 { 2314 unsigned long __user usymbol; 2315 const char **syms = NULL; 2316 char *buf = NULL, *p; 2317 int err = -ENOMEM; 2318 unsigned int i; 2319 2320 syms = kvmalloc_array(cnt, sizeof(*syms), GFP_KERNEL); 2321 if (!syms) 2322 goto error; 2323 2324 buf = kvmalloc_array(cnt, KSYM_NAME_LEN, GFP_KERNEL); 2325 if (!buf) 2326 goto error; 2327 2328 for (p = buf, i = 0; i < cnt; i++) { 2329 if (__get_user(usymbol, usyms + i)) { 2330 err = -EFAULT; 2331 goto error; 2332 } 2333 err = strncpy_from_user(p, (const char __user *) usymbol, KSYM_NAME_LEN); 2334 if (err == KSYM_NAME_LEN) 2335 err = -E2BIG; 2336 if (err < 0) 2337 goto error; 2338 syms[i] = p; 2339 p += err + 1; 2340 } 2341 2342 us->syms = syms; 2343 us->buf = buf; 2344 return 0; 2345 2346 error: 2347 if (err) { 2348 kvfree(syms); 2349 kvfree(buf); 2350 } 2351 return err; 2352 } 2353 2354 static void kprobe_multi_put_modules(struct module **mods, u32 cnt) 2355 { 2356 u32 i; 2357 2358 for (i = 0; i < cnt; i++) 2359 module_put(mods[i]); 2360 } 2361 2362 static void free_user_syms(struct user_syms *us) 2363 { 2364 kvfree(us->syms); 2365 kvfree(us->buf); 2366 } 2367 2368 static void bpf_kprobe_multi_link_release(struct bpf_link *link) 2369 { 2370 struct bpf_kprobe_multi_link *kmulti_link; 2371 2372 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); 2373 unregister_fprobe(&kmulti_link->fp); 2374 kprobe_multi_put_modules(kmulti_link->mods, kmulti_link->mods_cnt); 2375 } 2376 2377 static void bpf_kprobe_multi_link_dealloc(struct bpf_link *link) 2378 { 2379 struct bpf_kprobe_multi_link *kmulti_link; 2380 2381 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); 2382 kvfree(kmulti_link->addrs); 2383 kvfree(kmulti_link->cookies); 2384 kfree(kmulti_link->mods); 2385 kfree(kmulti_link); 2386 } 2387 2388 static int bpf_kprobe_multi_link_fill_link_info(const struct bpf_link *link, 2389 struct bpf_link_info *info) 2390 { 2391 u64 __user *ucookies = u64_to_user_ptr(info->kprobe_multi.cookies); 2392 u64 __user *uaddrs = u64_to_user_ptr(info->kprobe_multi.addrs); 2393 struct bpf_kprobe_multi_link *kmulti_link; 2394 u32 ucount = info->kprobe_multi.count; 2395 int err = 0, i; 2396 2397 if (!uaddrs ^ !ucount) 2398 return -EINVAL; 2399 if (ucookies && !ucount) 2400 return -EINVAL; 2401 2402 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); 2403 info->kprobe_multi.count = kmulti_link->cnt; 2404 info->kprobe_multi.flags = kmulti_link->link.flags; 2405 info->kprobe_multi.missed = kmulti_link->fp.nmissed; 2406 2407 if (!uaddrs) 2408 return 0; 2409 if (ucount < kmulti_link->cnt) 2410 err = -ENOSPC; 2411 else 2412 ucount = kmulti_link->cnt; 2413 2414 if (ucookies) { 2415 if (kmulti_link->cookies) { 2416 if (copy_to_user(ucookies, kmulti_link->cookies, ucount * sizeof(u64))) 2417 return -EFAULT; 2418 } else { 2419 for (i = 0; i < ucount; i++) { 2420 if (put_user(0, ucookies + i)) 2421 return -EFAULT; 2422 } 2423 } 2424 } 2425 2426 if (kallsyms_show_value(current_cred())) { 2427 if (copy_to_user(uaddrs, kmulti_link->addrs, ucount * sizeof(u64))) 2428 return -EFAULT; 2429 } else { 2430 for (i = 0; i < ucount; i++) { 2431 if (put_user(0, uaddrs + i)) 2432 return -EFAULT; 2433 } 2434 } 2435 return err; 2436 } 2437 2438 #ifdef CONFIG_PROC_FS 2439 static void bpf_kprobe_multi_show_fdinfo(const struct bpf_link *link, 2440 struct seq_file *seq) 2441 { 2442 struct bpf_kprobe_multi_link *kmulti_link; 2443 2444 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); 2445 2446 seq_printf(seq, 2447 "kprobe_cnt:\t%u\n" 2448 "missed:\t%lu\n", 2449 kmulti_link->cnt, 2450 kmulti_link->fp.nmissed); 2451 2452 seq_printf(seq, "%s\t %s\n", "cookie", "func"); 2453 for (int i = 0; i < kmulti_link->cnt; i++) { 2454 seq_printf(seq, 2455 "%llu\t %pS\n", 2456 kmulti_link->cookies[i], 2457 (void *)kmulti_link->addrs[i]); 2458 } 2459 } 2460 #endif 2461 2462 static const struct bpf_link_ops bpf_kprobe_multi_link_lops = { 2463 .release = bpf_kprobe_multi_link_release, 2464 .dealloc_deferred = bpf_kprobe_multi_link_dealloc, 2465 .fill_link_info = bpf_kprobe_multi_link_fill_link_info, 2466 #ifdef CONFIG_PROC_FS 2467 .show_fdinfo = bpf_kprobe_multi_show_fdinfo, 2468 #endif 2469 }; 2470 2471 static void bpf_kprobe_multi_cookie_swap(void *a, void *b, int size, const void *priv) 2472 { 2473 const struct bpf_kprobe_multi_link *link = priv; 2474 unsigned long *addr_a = a, *addr_b = b; 2475 u64 *cookie_a, *cookie_b; 2476 2477 cookie_a = link->cookies + (addr_a - link->addrs); 2478 cookie_b = link->cookies + (addr_b - link->addrs); 2479 2480 /* swap addr_a/addr_b and cookie_a/cookie_b values */ 2481 swap(*addr_a, *addr_b); 2482 swap(*cookie_a, *cookie_b); 2483 } 2484 2485 static int bpf_kprobe_multi_addrs_cmp(const void *a, const void *b) 2486 { 2487 const unsigned long *addr_a = a, *addr_b = b; 2488 2489 if (*addr_a == *addr_b) 2490 return 0; 2491 return *addr_a < *addr_b ? -1 : 1; 2492 } 2493 2494 static int bpf_kprobe_multi_cookie_cmp(const void *a, const void *b, const void *priv) 2495 { 2496 return bpf_kprobe_multi_addrs_cmp(a, b); 2497 } 2498 2499 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx) 2500 { 2501 struct bpf_kprobe_multi_run_ctx *run_ctx; 2502 struct bpf_kprobe_multi_link *link; 2503 u64 *cookie, entry_ip; 2504 unsigned long *addr; 2505 2506 if (WARN_ON_ONCE(!ctx)) 2507 return 0; 2508 run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, 2509 session_ctx.run_ctx); 2510 link = run_ctx->link; 2511 if (!link->cookies) 2512 return 0; 2513 entry_ip = run_ctx->entry_ip; 2514 addr = bsearch(&entry_ip, link->addrs, link->cnt, sizeof(entry_ip), 2515 bpf_kprobe_multi_addrs_cmp); 2516 if (!addr) 2517 return 0; 2518 cookie = link->cookies + (addr - link->addrs); 2519 return *cookie; 2520 } 2521 2522 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 2523 { 2524 struct bpf_kprobe_multi_run_ctx *run_ctx; 2525 2526 run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, 2527 session_ctx.run_ctx); 2528 return run_ctx->entry_ip; 2529 } 2530 2531 static int 2532 kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link, 2533 unsigned long entry_ip, struct ftrace_regs *fregs, 2534 bool is_return, void *data) 2535 { 2536 struct bpf_kprobe_multi_run_ctx run_ctx = { 2537 .session_ctx = { 2538 .is_return = is_return, 2539 .data = data, 2540 }, 2541 .link = link, 2542 .entry_ip = entry_ip, 2543 }; 2544 struct bpf_run_ctx *old_run_ctx; 2545 struct pt_regs *regs; 2546 int err; 2547 2548 /* 2549 * graph tracer framework ensures we won't migrate, so there is no need 2550 * to use migrate_disable for bpf_prog_run again. The check here just for 2551 * __this_cpu_inc_return. 2552 */ 2553 cant_sleep(); 2554 2555 if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) { 2556 bpf_prog_inc_misses_counter(link->link.prog); 2557 err = 1; 2558 goto out; 2559 } 2560 2561 rcu_read_lock(); 2562 regs = ftrace_partial_regs(fregs, bpf_kprobe_multi_pt_regs_ptr()); 2563 old_run_ctx = bpf_set_run_ctx(&run_ctx.session_ctx.run_ctx); 2564 err = bpf_prog_run(link->link.prog, regs); 2565 bpf_reset_run_ctx(old_run_ctx); 2566 rcu_read_unlock(); 2567 2568 out: 2569 __this_cpu_dec(bpf_prog_active); 2570 return err; 2571 } 2572 2573 static int 2574 kprobe_multi_link_handler(struct fprobe *fp, unsigned long fentry_ip, 2575 unsigned long ret_ip, struct ftrace_regs *fregs, 2576 void *data) 2577 { 2578 struct bpf_kprobe_multi_link *link; 2579 int err; 2580 2581 link = container_of(fp, struct bpf_kprobe_multi_link, fp); 2582 err = kprobe_multi_link_prog_run(link, ftrace_get_entry_ip(fentry_ip), 2583 fregs, false, data); 2584 return is_kprobe_session(link->link.prog) ? err : 0; 2585 } 2586 2587 static void 2588 kprobe_multi_link_exit_handler(struct fprobe *fp, unsigned long fentry_ip, 2589 unsigned long ret_ip, struct ftrace_regs *fregs, 2590 void *data) 2591 { 2592 struct bpf_kprobe_multi_link *link; 2593 2594 link = container_of(fp, struct bpf_kprobe_multi_link, fp); 2595 kprobe_multi_link_prog_run(link, ftrace_get_entry_ip(fentry_ip), 2596 fregs, true, data); 2597 } 2598 2599 static int symbols_cmp_r(const void *a, const void *b, const void *priv) 2600 { 2601 const char **str_a = (const char **) a; 2602 const char **str_b = (const char **) b; 2603 2604 return strcmp(*str_a, *str_b); 2605 } 2606 2607 struct multi_symbols_sort { 2608 const char **funcs; 2609 u64 *cookies; 2610 }; 2611 2612 static void symbols_swap_r(void *a, void *b, int size, const void *priv) 2613 { 2614 const struct multi_symbols_sort *data = priv; 2615 const char **name_a = a, **name_b = b; 2616 2617 swap(*name_a, *name_b); 2618 2619 /* If defined, swap also related cookies. */ 2620 if (data->cookies) { 2621 u64 *cookie_a, *cookie_b; 2622 2623 cookie_a = data->cookies + (name_a - data->funcs); 2624 cookie_b = data->cookies + (name_b - data->funcs); 2625 swap(*cookie_a, *cookie_b); 2626 } 2627 } 2628 2629 struct modules_array { 2630 struct module **mods; 2631 int mods_cnt; 2632 int mods_cap; 2633 }; 2634 2635 static int add_module(struct modules_array *arr, struct module *mod) 2636 { 2637 struct module **mods; 2638 2639 if (arr->mods_cnt == arr->mods_cap) { 2640 arr->mods_cap = max(16, arr->mods_cap * 3 / 2); 2641 mods = krealloc_array(arr->mods, arr->mods_cap, sizeof(*mods), GFP_KERNEL); 2642 if (!mods) 2643 return -ENOMEM; 2644 arr->mods = mods; 2645 } 2646 2647 arr->mods[arr->mods_cnt] = mod; 2648 arr->mods_cnt++; 2649 return 0; 2650 } 2651 2652 static bool has_module(struct modules_array *arr, struct module *mod) 2653 { 2654 int i; 2655 2656 for (i = arr->mods_cnt - 1; i >= 0; i--) { 2657 if (arr->mods[i] == mod) 2658 return true; 2659 } 2660 return false; 2661 } 2662 2663 static int get_modules_for_addrs(struct module ***mods, unsigned long *addrs, u32 addrs_cnt) 2664 { 2665 struct modules_array arr = {}; 2666 u32 i, err = 0; 2667 2668 for (i = 0; i < addrs_cnt; i++) { 2669 bool skip_add = false; 2670 struct module *mod; 2671 2672 scoped_guard(rcu) { 2673 mod = __module_address(addrs[i]); 2674 /* Either no module or it's already stored */ 2675 if (!mod || has_module(&arr, mod)) { 2676 skip_add = true; 2677 break; /* scoped_guard */ 2678 } 2679 if (!try_module_get(mod)) 2680 err = -EINVAL; 2681 } 2682 if (skip_add) 2683 continue; 2684 if (err) 2685 break; 2686 err = add_module(&arr, mod); 2687 if (err) { 2688 module_put(mod); 2689 break; 2690 } 2691 } 2692 2693 /* We return either err < 0 in case of error, ... */ 2694 if (err) { 2695 kprobe_multi_put_modules(arr.mods, arr.mods_cnt); 2696 kfree(arr.mods); 2697 return err; 2698 } 2699 2700 /* or number of modules found if everything is ok. */ 2701 *mods = arr.mods; 2702 return arr.mods_cnt; 2703 } 2704 2705 static int addrs_check_error_injection_list(unsigned long *addrs, u32 cnt) 2706 { 2707 u32 i; 2708 2709 for (i = 0; i < cnt; i++) { 2710 if (!within_error_injection_list(addrs[i])) 2711 return -EINVAL; 2712 } 2713 return 0; 2714 } 2715 2716 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 2717 { 2718 struct bpf_kprobe_multi_link *link = NULL; 2719 struct bpf_link_primer link_primer; 2720 void __user *ucookies; 2721 unsigned long *addrs; 2722 u32 flags, cnt, size; 2723 void __user *uaddrs; 2724 u64 *cookies = NULL; 2725 void __user *usyms; 2726 int err; 2727 2728 /* no support for 32bit archs yet */ 2729 if (sizeof(u64) != sizeof(void *)) 2730 return -EOPNOTSUPP; 2731 2732 if (attr->link_create.flags) 2733 return -EINVAL; 2734 2735 if (!is_kprobe_multi(prog)) 2736 return -EINVAL; 2737 2738 flags = attr->link_create.kprobe_multi.flags; 2739 if (flags & ~BPF_F_KPROBE_MULTI_RETURN) 2740 return -EINVAL; 2741 2742 uaddrs = u64_to_user_ptr(attr->link_create.kprobe_multi.addrs); 2743 usyms = u64_to_user_ptr(attr->link_create.kprobe_multi.syms); 2744 if (!!uaddrs == !!usyms) 2745 return -EINVAL; 2746 2747 cnt = attr->link_create.kprobe_multi.cnt; 2748 if (!cnt) 2749 return -EINVAL; 2750 if (cnt > MAX_KPROBE_MULTI_CNT) 2751 return -E2BIG; 2752 2753 size = cnt * sizeof(*addrs); 2754 addrs = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL); 2755 if (!addrs) 2756 return -ENOMEM; 2757 2758 ucookies = u64_to_user_ptr(attr->link_create.kprobe_multi.cookies); 2759 if (ucookies) { 2760 cookies = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL); 2761 if (!cookies) { 2762 err = -ENOMEM; 2763 goto error; 2764 } 2765 if (copy_from_user(cookies, ucookies, size)) { 2766 err = -EFAULT; 2767 goto error; 2768 } 2769 } 2770 2771 if (uaddrs) { 2772 if (copy_from_user(addrs, uaddrs, size)) { 2773 err = -EFAULT; 2774 goto error; 2775 } 2776 } else { 2777 struct multi_symbols_sort data = { 2778 .cookies = cookies, 2779 }; 2780 struct user_syms us; 2781 2782 err = copy_user_syms(&us, usyms, cnt); 2783 if (err) 2784 goto error; 2785 2786 if (cookies) 2787 data.funcs = us.syms; 2788 2789 sort_r(us.syms, cnt, sizeof(*us.syms), symbols_cmp_r, 2790 symbols_swap_r, &data); 2791 2792 err = ftrace_lookup_symbols(us.syms, cnt, addrs); 2793 free_user_syms(&us); 2794 if (err) 2795 goto error; 2796 } 2797 2798 if (prog->kprobe_override && addrs_check_error_injection_list(addrs, cnt)) { 2799 err = -EINVAL; 2800 goto error; 2801 } 2802 2803 link = kzalloc(sizeof(*link), GFP_KERNEL); 2804 if (!link) { 2805 err = -ENOMEM; 2806 goto error; 2807 } 2808 2809 bpf_link_init(&link->link, BPF_LINK_TYPE_KPROBE_MULTI, 2810 &bpf_kprobe_multi_link_lops, prog, attr->link_create.attach_type); 2811 2812 err = bpf_link_prime(&link->link, &link_primer); 2813 if (err) 2814 goto error; 2815 2816 if (!(flags & BPF_F_KPROBE_MULTI_RETURN)) 2817 link->fp.entry_handler = kprobe_multi_link_handler; 2818 if ((flags & BPF_F_KPROBE_MULTI_RETURN) || is_kprobe_session(prog)) 2819 link->fp.exit_handler = kprobe_multi_link_exit_handler; 2820 if (is_kprobe_session(prog)) 2821 link->fp.entry_data_size = sizeof(u64); 2822 2823 link->addrs = addrs; 2824 link->cookies = cookies; 2825 link->cnt = cnt; 2826 link->link.flags = flags; 2827 2828 if (cookies) { 2829 /* 2830 * Sorting addresses will trigger sorting cookies as well 2831 * (check bpf_kprobe_multi_cookie_swap). This way we can 2832 * find cookie based on the address in bpf_get_attach_cookie 2833 * helper. 2834 */ 2835 sort_r(addrs, cnt, sizeof(*addrs), 2836 bpf_kprobe_multi_cookie_cmp, 2837 bpf_kprobe_multi_cookie_swap, 2838 link); 2839 } 2840 2841 err = get_modules_for_addrs(&link->mods, addrs, cnt); 2842 if (err < 0) { 2843 bpf_link_cleanup(&link_primer); 2844 return err; 2845 } 2846 link->mods_cnt = err; 2847 2848 err = register_fprobe_ips(&link->fp, addrs, cnt); 2849 if (err) { 2850 kprobe_multi_put_modules(link->mods, link->mods_cnt); 2851 bpf_link_cleanup(&link_primer); 2852 return err; 2853 } 2854 2855 return bpf_link_settle(&link_primer); 2856 2857 error: 2858 kfree(link); 2859 kvfree(addrs); 2860 kvfree(cookies); 2861 return err; 2862 } 2863 #else /* !CONFIG_FPROBE */ 2864 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 2865 { 2866 return -EOPNOTSUPP; 2867 } 2868 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx) 2869 { 2870 return 0; 2871 } 2872 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 2873 { 2874 return 0; 2875 } 2876 #endif 2877 2878 #ifdef CONFIG_UPROBES 2879 struct bpf_uprobe_multi_link; 2880 2881 struct bpf_uprobe { 2882 struct bpf_uprobe_multi_link *link; 2883 loff_t offset; 2884 unsigned long ref_ctr_offset; 2885 u64 cookie; 2886 struct uprobe *uprobe; 2887 struct uprobe_consumer consumer; 2888 bool session; 2889 }; 2890 2891 struct bpf_uprobe_multi_link { 2892 struct path path; 2893 struct bpf_link link; 2894 u32 cnt; 2895 struct bpf_uprobe *uprobes; 2896 struct task_struct *task; 2897 }; 2898 2899 struct bpf_uprobe_multi_run_ctx { 2900 struct bpf_session_run_ctx session_ctx; 2901 unsigned long entry_ip; 2902 struct bpf_uprobe *uprobe; 2903 }; 2904 2905 static void bpf_uprobe_unregister(struct bpf_uprobe *uprobes, u32 cnt) 2906 { 2907 u32 i; 2908 2909 for (i = 0; i < cnt; i++) 2910 uprobe_unregister_nosync(uprobes[i].uprobe, &uprobes[i].consumer); 2911 2912 if (cnt) 2913 uprobe_unregister_sync(); 2914 } 2915 2916 static void bpf_uprobe_multi_link_release(struct bpf_link *link) 2917 { 2918 struct bpf_uprobe_multi_link *umulti_link; 2919 2920 umulti_link = container_of(link, struct bpf_uprobe_multi_link, link); 2921 bpf_uprobe_unregister(umulti_link->uprobes, umulti_link->cnt); 2922 if (umulti_link->task) 2923 put_task_struct(umulti_link->task); 2924 path_put(&umulti_link->path); 2925 } 2926 2927 static void bpf_uprobe_multi_link_dealloc(struct bpf_link *link) 2928 { 2929 struct bpf_uprobe_multi_link *umulti_link; 2930 2931 umulti_link = container_of(link, struct bpf_uprobe_multi_link, link); 2932 kvfree(umulti_link->uprobes); 2933 kfree(umulti_link); 2934 } 2935 2936 static int bpf_uprobe_multi_link_fill_link_info(const struct bpf_link *link, 2937 struct bpf_link_info *info) 2938 { 2939 u64 __user *uref_ctr_offsets = u64_to_user_ptr(info->uprobe_multi.ref_ctr_offsets); 2940 u64 __user *ucookies = u64_to_user_ptr(info->uprobe_multi.cookies); 2941 u64 __user *uoffsets = u64_to_user_ptr(info->uprobe_multi.offsets); 2942 u64 __user *upath = u64_to_user_ptr(info->uprobe_multi.path); 2943 u32 upath_size = info->uprobe_multi.path_size; 2944 struct bpf_uprobe_multi_link *umulti_link; 2945 u32 ucount = info->uprobe_multi.count; 2946 int err = 0, i; 2947 char *p, *buf; 2948 long left = 0; 2949 2950 if (!upath ^ !upath_size) 2951 return -EINVAL; 2952 2953 if ((uoffsets || uref_ctr_offsets || ucookies) && !ucount) 2954 return -EINVAL; 2955 2956 umulti_link = container_of(link, struct bpf_uprobe_multi_link, link); 2957 info->uprobe_multi.count = umulti_link->cnt; 2958 info->uprobe_multi.flags = umulti_link->link.flags; 2959 info->uprobe_multi.pid = umulti_link->task ? 2960 task_pid_nr_ns(umulti_link->task, task_active_pid_ns(current)) : 0; 2961 2962 upath_size = upath_size ? min_t(u32, upath_size, PATH_MAX) : PATH_MAX; 2963 buf = kmalloc(upath_size, GFP_KERNEL); 2964 if (!buf) 2965 return -ENOMEM; 2966 p = d_path(&umulti_link->path, buf, upath_size); 2967 if (IS_ERR(p)) { 2968 kfree(buf); 2969 return PTR_ERR(p); 2970 } 2971 upath_size = buf + upath_size - p; 2972 2973 if (upath) 2974 left = copy_to_user(upath, p, upath_size); 2975 kfree(buf); 2976 if (left) 2977 return -EFAULT; 2978 info->uprobe_multi.path_size = upath_size; 2979 2980 if (!uoffsets && !ucookies && !uref_ctr_offsets) 2981 return 0; 2982 2983 if (ucount < umulti_link->cnt) 2984 err = -ENOSPC; 2985 else 2986 ucount = umulti_link->cnt; 2987 2988 for (i = 0; i < ucount; i++) { 2989 if (uoffsets && 2990 put_user(umulti_link->uprobes[i].offset, uoffsets + i)) 2991 return -EFAULT; 2992 if (uref_ctr_offsets && 2993 put_user(umulti_link->uprobes[i].ref_ctr_offset, uref_ctr_offsets + i)) 2994 return -EFAULT; 2995 if (ucookies && 2996 put_user(umulti_link->uprobes[i].cookie, ucookies + i)) 2997 return -EFAULT; 2998 } 2999 3000 return err; 3001 } 3002 3003 #ifdef CONFIG_PROC_FS 3004 static void bpf_uprobe_multi_show_fdinfo(const struct bpf_link *link, 3005 struct seq_file *seq) 3006 { 3007 struct bpf_uprobe_multi_link *umulti_link; 3008 char *p, *buf; 3009 pid_t pid; 3010 3011 umulti_link = container_of(link, struct bpf_uprobe_multi_link, link); 3012 3013 buf = kmalloc(PATH_MAX, GFP_KERNEL); 3014 if (!buf) 3015 return; 3016 3017 p = d_path(&umulti_link->path, buf, PATH_MAX); 3018 if (IS_ERR(p)) { 3019 kfree(buf); 3020 return; 3021 } 3022 3023 pid = umulti_link->task ? 3024 task_pid_nr_ns(umulti_link->task, task_active_pid_ns(current)) : 0; 3025 seq_printf(seq, 3026 "uprobe_cnt:\t%u\n" 3027 "pid:\t%u\n" 3028 "path:\t%s\n", 3029 umulti_link->cnt, pid, p); 3030 3031 seq_printf(seq, "%s\t %s\t %s\n", "cookie", "offset", "ref_ctr_offset"); 3032 for (int i = 0; i < umulti_link->cnt; i++) { 3033 seq_printf(seq, 3034 "%llu\t %#llx\t %#lx\n", 3035 umulti_link->uprobes[i].cookie, 3036 umulti_link->uprobes[i].offset, 3037 umulti_link->uprobes[i].ref_ctr_offset); 3038 } 3039 3040 kfree(buf); 3041 } 3042 #endif 3043 3044 static const struct bpf_link_ops bpf_uprobe_multi_link_lops = { 3045 .release = bpf_uprobe_multi_link_release, 3046 .dealloc_deferred = bpf_uprobe_multi_link_dealloc, 3047 .fill_link_info = bpf_uprobe_multi_link_fill_link_info, 3048 #ifdef CONFIG_PROC_FS 3049 .show_fdinfo = bpf_uprobe_multi_show_fdinfo, 3050 #endif 3051 }; 3052 3053 static int uprobe_prog_run(struct bpf_uprobe *uprobe, 3054 unsigned long entry_ip, 3055 struct pt_regs *regs, 3056 bool is_return, void *data) 3057 { 3058 struct bpf_uprobe_multi_link *link = uprobe->link; 3059 struct bpf_uprobe_multi_run_ctx run_ctx = { 3060 .session_ctx = { 3061 .is_return = is_return, 3062 .data = data, 3063 }, 3064 .entry_ip = entry_ip, 3065 .uprobe = uprobe, 3066 }; 3067 struct bpf_prog *prog = link->link.prog; 3068 bool sleepable = prog->sleepable; 3069 struct bpf_run_ctx *old_run_ctx; 3070 int err; 3071 3072 if (link->task && !same_thread_group(current, link->task)) 3073 return 0; 3074 3075 if (sleepable) 3076 rcu_read_lock_trace(); 3077 else 3078 rcu_read_lock(); 3079 3080 migrate_disable(); 3081 3082 old_run_ctx = bpf_set_run_ctx(&run_ctx.session_ctx.run_ctx); 3083 err = bpf_prog_run(link->link.prog, regs); 3084 bpf_reset_run_ctx(old_run_ctx); 3085 3086 migrate_enable(); 3087 3088 if (sleepable) 3089 rcu_read_unlock_trace(); 3090 else 3091 rcu_read_unlock(); 3092 return err; 3093 } 3094 3095 static bool 3096 uprobe_multi_link_filter(struct uprobe_consumer *con, struct mm_struct *mm) 3097 { 3098 struct bpf_uprobe *uprobe; 3099 3100 uprobe = container_of(con, struct bpf_uprobe, consumer); 3101 return uprobe->link->task->mm == mm; 3102 } 3103 3104 static int 3105 uprobe_multi_link_handler(struct uprobe_consumer *con, struct pt_regs *regs, 3106 __u64 *data) 3107 { 3108 struct bpf_uprobe *uprobe; 3109 int ret; 3110 3111 uprobe = container_of(con, struct bpf_uprobe, consumer); 3112 ret = uprobe_prog_run(uprobe, instruction_pointer(regs), regs, false, data); 3113 if (uprobe->session) 3114 return ret ? UPROBE_HANDLER_IGNORE : 0; 3115 return 0; 3116 } 3117 3118 static int 3119 uprobe_multi_link_ret_handler(struct uprobe_consumer *con, unsigned long func, struct pt_regs *regs, 3120 __u64 *data) 3121 { 3122 struct bpf_uprobe *uprobe; 3123 3124 uprobe = container_of(con, struct bpf_uprobe, consumer); 3125 uprobe_prog_run(uprobe, func, regs, true, data); 3126 return 0; 3127 } 3128 3129 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 3130 { 3131 struct bpf_uprobe_multi_run_ctx *run_ctx; 3132 3133 run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx, 3134 session_ctx.run_ctx); 3135 return run_ctx->entry_ip; 3136 } 3137 3138 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx) 3139 { 3140 struct bpf_uprobe_multi_run_ctx *run_ctx; 3141 3142 run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx, 3143 session_ctx.run_ctx); 3144 return run_ctx->uprobe->cookie; 3145 } 3146 3147 int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 3148 { 3149 struct bpf_uprobe_multi_link *link = NULL; 3150 unsigned long __user *uref_ctr_offsets; 3151 struct bpf_link_primer link_primer; 3152 struct bpf_uprobe *uprobes = NULL; 3153 struct task_struct *task = NULL; 3154 unsigned long __user *uoffsets; 3155 u64 __user *ucookies; 3156 void __user *upath; 3157 u32 flags, cnt, i; 3158 struct path path; 3159 char *name; 3160 pid_t pid; 3161 int err; 3162 3163 /* no support for 32bit archs yet */ 3164 if (sizeof(u64) != sizeof(void *)) 3165 return -EOPNOTSUPP; 3166 3167 if (attr->link_create.flags) 3168 return -EINVAL; 3169 3170 if (!is_uprobe_multi(prog)) 3171 return -EINVAL; 3172 3173 flags = attr->link_create.uprobe_multi.flags; 3174 if (flags & ~BPF_F_UPROBE_MULTI_RETURN) 3175 return -EINVAL; 3176 3177 /* 3178 * path, offsets and cnt are mandatory, 3179 * ref_ctr_offsets and cookies are optional 3180 */ 3181 upath = u64_to_user_ptr(attr->link_create.uprobe_multi.path); 3182 uoffsets = u64_to_user_ptr(attr->link_create.uprobe_multi.offsets); 3183 cnt = attr->link_create.uprobe_multi.cnt; 3184 pid = attr->link_create.uprobe_multi.pid; 3185 3186 if (!upath || !uoffsets || !cnt || pid < 0) 3187 return -EINVAL; 3188 if (cnt > MAX_UPROBE_MULTI_CNT) 3189 return -E2BIG; 3190 3191 uref_ctr_offsets = u64_to_user_ptr(attr->link_create.uprobe_multi.ref_ctr_offsets); 3192 ucookies = u64_to_user_ptr(attr->link_create.uprobe_multi.cookies); 3193 3194 name = strndup_user(upath, PATH_MAX); 3195 if (IS_ERR(name)) { 3196 err = PTR_ERR(name); 3197 return err; 3198 } 3199 3200 err = kern_path(name, LOOKUP_FOLLOW, &path); 3201 kfree(name); 3202 if (err) 3203 return err; 3204 3205 if (!d_is_reg(path.dentry)) { 3206 err = -EBADF; 3207 goto error_path_put; 3208 } 3209 3210 if (pid) { 3211 rcu_read_lock(); 3212 task = get_pid_task(find_vpid(pid), PIDTYPE_TGID); 3213 rcu_read_unlock(); 3214 if (!task) { 3215 err = -ESRCH; 3216 goto error_path_put; 3217 } 3218 } 3219 3220 err = -ENOMEM; 3221 3222 link = kzalloc(sizeof(*link), GFP_KERNEL); 3223 uprobes = kvcalloc(cnt, sizeof(*uprobes), GFP_KERNEL); 3224 3225 if (!uprobes || !link) 3226 goto error_free; 3227 3228 for (i = 0; i < cnt; i++) { 3229 if (__get_user(uprobes[i].offset, uoffsets + i)) { 3230 err = -EFAULT; 3231 goto error_free; 3232 } 3233 if (uprobes[i].offset < 0) { 3234 err = -EINVAL; 3235 goto error_free; 3236 } 3237 if (uref_ctr_offsets && __get_user(uprobes[i].ref_ctr_offset, uref_ctr_offsets + i)) { 3238 err = -EFAULT; 3239 goto error_free; 3240 } 3241 if (ucookies && __get_user(uprobes[i].cookie, ucookies + i)) { 3242 err = -EFAULT; 3243 goto error_free; 3244 } 3245 3246 uprobes[i].link = link; 3247 3248 if (!(flags & BPF_F_UPROBE_MULTI_RETURN)) 3249 uprobes[i].consumer.handler = uprobe_multi_link_handler; 3250 if (flags & BPF_F_UPROBE_MULTI_RETURN || is_uprobe_session(prog)) 3251 uprobes[i].consumer.ret_handler = uprobe_multi_link_ret_handler; 3252 if (is_uprobe_session(prog)) 3253 uprobes[i].session = true; 3254 if (pid) 3255 uprobes[i].consumer.filter = uprobe_multi_link_filter; 3256 } 3257 3258 link->cnt = cnt; 3259 link->uprobes = uprobes; 3260 link->path = path; 3261 link->task = task; 3262 link->link.flags = flags; 3263 3264 bpf_link_init(&link->link, BPF_LINK_TYPE_UPROBE_MULTI, 3265 &bpf_uprobe_multi_link_lops, prog, attr->link_create.attach_type); 3266 3267 for (i = 0; i < cnt; i++) { 3268 uprobes[i].uprobe = uprobe_register(d_real_inode(link->path.dentry), 3269 uprobes[i].offset, 3270 uprobes[i].ref_ctr_offset, 3271 &uprobes[i].consumer); 3272 if (IS_ERR(uprobes[i].uprobe)) { 3273 err = PTR_ERR(uprobes[i].uprobe); 3274 link->cnt = i; 3275 goto error_unregister; 3276 } 3277 } 3278 3279 err = bpf_link_prime(&link->link, &link_primer); 3280 if (err) 3281 goto error_unregister; 3282 3283 return bpf_link_settle(&link_primer); 3284 3285 error_unregister: 3286 bpf_uprobe_unregister(uprobes, link->cnt); 3287 3288 error_free: 3289 kvfree(uprobes); 3290 kfree(link); 3291 if (task) 3292 put_task_struct(task); 3293 error_path_put: 3294 path_put(&path); 3295 return err; 3296 } 3297 #else /* !CONFIG_UPROBES */ 3298 int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 3299 { 3300 return -EOPNOTSUPP; 3301 } 3302 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx) 3303 { 3304 return 0; 3305 } 3306 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 3307 { 3308 return 0; 3309 } 3310 #endif /* CONFIG_UPROBES */ 3311 3312 __bpf_kfunc_start_defs(); 3313 3314 __bpf_kfunc bool bpf_session_is_return(void) 3315 { 3316 struct bpf_session_run_ctx *session_ctx; 3317 3318 session_ctx = container_of(current->bpf_ctx, struct bpf_session_run_ctx, run_ctx); 3319 return session_ctx->is_return; 3320 } 3321 3322 __bpf_kfunc __u64 *bpf_session_cookie(void) 3323 { 3324 struct bpf_session_run_ctx *session_ctx; 3325 3326 session_ctx = container_of(current->bpf_ctx, struct bpf_session_run_ctx, run_ctx); 3327 return session_ctx->data; 3328 } 3329 3330 __bpf_kfunc_end_defs(); 3331 3332 BTF_KFUNCS_START(kprobe_multi_kfunc_set_ids) 3333 BTF_ID_FLAGS(func, bpf_session_is_return) 3334 BTF_ID_FLAGS(func, bpf_session_cookie) 3335 BTF_KFUNCS_END(kprobe_multi_kfunc_set_ids) 3336 3337 static int bpf_kprobe_multi_filter(const struct bpf_prog *prog, u32 kfunc_id) 3338 { 3339 if (!btf_id_set8_contains(&kprobe_multi_kfunc_set_ids, kfunc_id)) 3340 return 0; 3341 3342 if (!is_kprobe_session(prog) && !is_uprobe_session(prog)) 3343 return -EACCES; 3344 3345 return 0; 3346 } 3347 3348 static const struct btf_kfunc_id_set bpf_kprobe_multi_kfunc_set = { 3349 .owner = THIS_MODULE, 3350 .set = &kprobe_multi_kfunc_set_ids, 3351 .filter = bpf_kprobe_multi_filter, 3352 }; 3353 3354 static int __init bpf_kprobe_multi_kfuncs_init(void) 3355 { 3356 return register_btf_kfunc_id_set(BPF_PROG_TYPE_KPROBE, &bpf_kprobe_multi_kfunc_set); 3357 } 3358 3359 late_initcall(bpf_kprobe_multi_kfuncs_init); 3360 3361 typedef int (*copy_fn_t)(void *dst, const void *src, u32 size, struct task_struct *tsk); 3362 3363 /* 3364 * The __always_inline is to make sure the compiler doesn't 3365 * generate indirect calls into callbacks, which is expensive, 3366 * on some kernel configurations. This allows compiler to put 3367 * direct calls into all the specific callback implementations 3368 * (copy_user_data_sleepable, copy_user_data_nofault, and so on) 3369 */ 3370 static __always_inline int __bpf_dynptr_copy_str(struct bpf_dynptr *dptr, u32 doff, u32 size, 3371 const void *unsafe_src, 3372 copy_fn_t str_copy_fn, 3373 struct task_struct *tsk) 3374 { 3375 struct bpf_dynptr_kern *dst; 3376 u32 chunk_sz, off; 3377 void *dst_slice; 3378 int cnt, err; 3379 char buf[256]; 3380 3381 dst_slice = bpf_dynptr_slice_rdwr(dptr, doff, NULL, size); 3382 if (likely(dst_slice)) 3383 return str_copy_fn(dst_slice, unsafe_src, size, tsk); 3384 3385 dst = (struct bpf_dynptr_kern *)dptr; 3386 if (bpf_dynptr_check_off_len(dst, doff, size)) 3387 return -E2BIG; 3388 3389 for (off = 0; off < size; off += chunk_sz - 1) { 3390 chunk_sz = min_t(u32, sizeof(buf), size - off); 3391 /* Expect str_copy_fn to return count of copied bytes, including 3392 * zero terminator. Next iteration increment off by chunk_sz - 1 to 3393 * overwrite NUL. 3394 */ 3395 cnt = str_copy_fn(buf, unsafe_src + off, chunk_sz, tsk); 3396 if (cnt < 0) 3397 return cnt; 3398 err = __bpf_dynptr_write(dst, doff + off, buf, cnt, 0); 3399 if (err) 3400 return err; 3401 if (cnt < chunk_sz || chunk_sz == 1) /* we are done */ 3402 return off + cnt; 3403 } 3404 return off; 3405 } 3406 3407 static __always_inline int __bpf_dynptr_copy(const struct bpf_dynptr *dptr, u32 doff, 3408 u32 size, const void *unsafe_src, 3409 copy_fn_t copy_fn, struct task_struct *tsk) 3410 { 3411 struct bpf_dynptr_kern *dst; 3412 void *dst_slice; 3413 char buf[256]; 3414 u32 off, chunk_sz; 3415 int err; 3416 3417 dst_slice = bpf_dynptr_slice_rdwr(dptr, doff, NULL, size); 3418 if (likely(dst_slice)) 3419 return copy_fn(dst_slice, unsafe_src, size, tsk); 3420 3421 dst = (struct bpf_dynptr_kern *)dptr; 3422 if (bpf_dynptr_check_off_len(dst, doff, size)) 3423 return -E2BIG; 3424 3425 for (off = 0; off < size; off += chunk_sz) { 3426 chunk_sz = min_t(u32, sizeof(buf), size - off); 3427 err = copy_fn(buf, unsafe_src + off, chunk_sz, tsk); 3428 if (err) 3429 return err; 3430 err = __bpf_dynptr_write(dst, doff + off, buf, chunk_sz, 0); 3431 if (err) 3432 return err; 3433 } 3434 return 0; 3435 } 3436 3437 static __always_inline int copy_user_data_nofault(void *dst, const void *unsafe_src, 3438 u32 size, struct task_struct *tsk) 3439 { 3440 return copy_from_user_nofault(dst, (const void __user *)unsafe_src, size); 3441 } 3442 3443 static __always_inline int copy_user_data_sleepable(void *dst, const void *unsafe_src, 3444 u32 size, struct task_struct *tsk) 3445 { 3446 int ret; 3447 3448 if (!tsk) { /* Read from the current task */ 3449 ret = copy_from_user(dst, (const void __user *)unsafe_src, size); 3450 if (ret) 3451 return -EFAULT; 3452 return 0; 3453 } 3454 3455 ret = access_process_vm(tsk, (unsigned long)unsafe_src, dst, size, 0); 3456 if (ret != size) 3457 return -EFAULT; 3458 return 0; 3459 } 3460 3461 static __always_inline int copy_kernel_data_nofault(void *dst, const void *unsafe_src, 3462 u32 size, struct task_struct *tsk) 3463 { 3464 return copy_from_kernel_nofault(dst, unsafe_src, size); 3465 } 3466 3467 static __always_inline int copy_user_str_nofault(void *dst, const void *unsafe_src, 3468 u32 size, struct task_struct *tsk) 3469 { 3470 return strncpy_from_user_nofault(dst, (const void __user *)unsafe_src, size); 3471 } 3472 3473 static __always_inline int copy_user_str_sleepable(void *dst, const void *unsafe_src, 3474 u32 size, struct task_struct *tsk) 3475 { 3476 int ret; 3477 3478 if (unlikely(size == 0)) 3479 return 0; 3480 3481 if (tsk) { 3482 ret = copy_remote_vm_str(tsk, (unsigned long)unsafe_src, dst, size, 0); 3483 } else { 3484 ret = strncpy_from_user(dst, (const void __user *)unsafe_src, size - 1); 3485 /* strncpy_from_user does not guarantee NUL termination */ 3486 if (ret >= 0) 3487 ((char *)dst)[ret] = '\0'; 3488 } 3489 3490 if (ret < 0) 3491 return ret; 3492 return ret + 1; 3493 } 3494 3495 static __always_inline int copy_kernel_str_nofault(void *dst, const void *unsafe_src, 3496 u32 size, struct task_struct *tsk) 3497 { 3498 return strncpy_from_kernel_nofault(dst, unsafe_src, size); 3499 } 3500 3501 __bpf_kfunc_start_defs(); 3502 3503 __bpf_kfunc int bpf_send_signal_task(struct task_struct *task, int sig, enum pid_type type, 3504 u64 value) 3505 { 3506 if (type != PIDTYPE_PID && type != PIDTYPE_TGID) 3507 return -EINVAL; 3508 3509 return bpf_send_signal_common(sig, type, task, value); 3510 } 3511 3512 __bpf_kfunc int bpf_probe_read_user_dynptr(struct bpf_dynptr *dptr, u32 off, 3513 u32 size, const void __user *unsafe_ptr__ign) 3514 { 3515 return __bpf_dynptr_copy(dptr, off, size, (const void *)unsafe_ptr__ign, 3516 copy_user_data_nofault, NULL); 3517 } 3518 3519 __bpf_kfunc int bpf_probe_read_kernel_dynptr(struct bpf_dynptr *dptr, u32 off, 3520 u32 size, const void *unsafe_ptr__ign) 3521 { 3522 return __bpf_dynptr_copy(dptr, off, size, unsafe_ptr__ign, 3523 copy_kernel_data_nofault, NULL); 3524 } 3525 3526 __bpf_kfunc int bpf_probe_read_user_str_dynptr(struct bpf_dynptr *dptr, u32 off, 3527 u32 size, const void __user *unsafe_ptr__ign) 3528 { 3529 return __bpf_dynptr_copy_str(dptr, off, size, (const void *)unsafe_ptr__ign, 3530 copy_user_str_nofault, NULL); 3531 } 3532 3533 __bpf_kfunc int bpf_probe_read_kernel_str_dynptr(struct bpf_dynptr *dptr, u32 off, 3534 u32 size, const void *unsafe_ptr__ign) 3535 { 3536 return __bpf_dynptr_copy_str(dptr, off, size, unsafe_ptr__ign, 3537 copy_kernel_str_nofault, NULL); 3538 } 3539 3540 __bpf_kfunc int bpf_copy_from_user_dynptr(struct bpf_dynptr *dptr, u32 off, 3541 u32 size, const void __user *unsafe_ptr__ign) 3542 { 3543 return __bpf_dynptr_copy(dptr, off, size, (const void *)unsafe_ptr__ign, 3544 copy_user_data_sleepable, NULL); 3545 } 3546 3547 __bpf_kfunc int bpf_copy_from_user_str_dynptr(struct bpf_dynptr *dptr, u32 off, 3548 u32 size, const void __user *unsafe_ptr__ign) 3549 { 3550 return __bpf_dynptr_copy_str(dptr, off, size, (const void *)unsafe_ptr__ign, 3551 copy_user_str_sleepable, NULL); 3552 } 3553 3554 __bpf_kfunc int bpf_copy_from_user_task_dynptr(struct bpf_dynptr *dptr, u32 off, 3555 u32 size, const void __user *unsafe_ptr__ign, 3556 struct task_struct *tsk) 3557 { 3558 return __bpf_dynptr_copy(dptr, off, size, (const void *)unsafe_ptr__ign, 3559 copy_user_data_sleepable, tsk); 3560 } 3561 3562 __bpf_kfunc int bpf_copy_from_user_task_str_dynptr(struct bpf_dynptr *dptr, u32 off, 3563 u32 size, const void __user *unsafe_ptr__ign, 3564 struct task_struct *tsk) 3565 { 3566 return __bpf_dynptr_copy_str(dptr, off, size, (const void *)unsafe_ptr__ign, 3567 copy_user_str_sleepable, tsk); 3568 } 3569 3570 __bpf_kfunc_end_defs(); 3571