1 // SPDX-License-Identifier: GPL-2.0 2 /* Copyright (c) 2011-2015 PLUMgrid, http://plumgrid.com 3 * Copyright (c) 2016 Facebook 4 */ 5 #include <linux/kernel.h> 6 #include <linux/types.h> 7 #include <linux/slab.h> 8 #include <linux/bpf.h> 9 #include <linux/bpf_verifier.h> 10 #include <linux/bpf_perf_event.h> 11 #include <linux/btf.h> 12 #include <linux/filter.h> 13 #include <linux/uaccess.h> 14 #include <linux/ctype.h> 15 #include <linux/kprobes.h> 16 #include <linux/spinlock.h> 17 #include <linux/syscalls.h> 18 #include <linux/error-injection.h> 19 #include <linux/btf_ids.h> 20 #include <linux/bpf_lsm.h> 21 #include <linux/fprobe.h> 22 #include <linux/bsearch.h> 23 #include <linux/sort.h> 24 #include <linux/key.h> 25 #include <linux/verification.h> 26 #include <linux/namei.h> 27 28 #include <net/bpf_sk_storage.h> 29 30 #include <uapi/linux/bpf.h> 31 #include <uapi/linux/btf.h> 32 33 #include <asm/tlb.h> 34 35 #include "trace_probe.h" 36 #include "trace.h" 37 38 #define CREATE_TRACE_POINTS 39 #include "bpf_trace.h" 40 41 #define bpf_event_rcu_dereference(p) \ 42 rcu_dereference_protected(p, lockdep_is_held(&bpf_event_mutex)) 43 44 #define MAX_UPROBE_MULTI_CNT (1U << 20) 45 #define MAX_KPROBE_MULTI_CNT (1U << 20) 46 47 #ifdef CONFIG_MODULES 48 struct bpf_trace_module { 49 struct module *module; 50 struct list_head list; 51 }; 52 53 static LIST_HEAD(bpf_trace_modules); 54 static DEFINE_MUTEX(bpf_module_mutex); 55 56 static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name) 57 { 58 struct bpf_raw_event_map *btp, *ret = NULL; 59 struct bpf_trace_module *btm; 60 unsigned int i; 61 62 mutex_lock(&bpf_module_mutex); 63 list_for_each_entry(btm, &bpf_trace_modules, list) { 64 for (i = 0; i < btm->module->num_bpf_raw_events; ++i) { 65 btp = &btm->module->bpf_raw_events[i]; 66 if (!strcmp(btp->tp->name, name)) { 67 if (try_module_get(btm->module)) 68 ret = btp; 69 goto out; 70 } 71 } 72 } 73 out: 74 mutex_unlock(&bpf_module_mutex); 75 return ret; 76 } 77 #else 78 static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name) 79 { 80 return NULL; 81 } 82 #endif /* CONFIG_MODULES */ 83 84 u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); 85 u64 bpf_get_stack(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); 86 87 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size, 88 u64 flags, const struct btf **btf, 89 s32 *btf_id); 90 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx); 91 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx); 92 93 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx); 94 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx); 95 96 /** 97 * trace_call_bpf - invoke BPF program 98 * @call: tracepoint event 99 * @ctx: opaque context pointer 100 * 101 * kprobe handlers execute BPF programs via this helper. 102 * Can be used from static tracepoints in the future. 103 * 104 * Return: BPF programs always return an integer which is interpreted by 105 * kprobe handler as: 106 * 0 - return from kprobe (event is filtered out) 107 * 1 - store kprobe event into ring buffer 108 * Other values are reserved and currently alias to 1 109 */ 110 unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx) 111 { 112 unsigned int ret; 113 114 cant_sleep(); 115 116 if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) { 117 /* 118 * since some bpf program is already running on this cpu, 119 * don't call into another bpf program (same or different) 120 * and don't send kprobe event into ring-buffer, 121 * so return zero here 122 */ 123 rcu_read_lock(); 124 bpf_prog_inc_misses_counters(rcu_dereference(call->prog_array)); 125 rcu_read_unlock(); 126 ret = 0; 127 goto out; 128 } 129 130 /* 131 * Instead of moving rcu_read_lock/rcu_dereference/rcu_read_unlock 132 * to all call sites, we did a bpf_prog_array_valid() there to check 133 * whether call->prog_array is empty or not, which is 134 * a heuristic to speed up execution. 135 * 136 * If bpf_prog_array_valid() fetched prog_array was 137 * non-NULL, we go into trace_call_bpf() and do the actual 138 * proper rcu_dereference() under RCU lock. 139 * If it turns out that prog_array is NULL then, we bail out. 140 * For the opposite, if the bpf_prog_array_valid() fetched pointer 141 * was NULL, you'll skip the prog_array with the risk of missing 142 * out of events when it was updated in between this and the 143 * rcu_dereference() which is accepted risk. 144 */ 145 rcu_read_lock(); 146 ret = bpf_prog_run_array(rcu_dereference(call->prog_array), 147 ctx, bpf_prog_run); 148 rcu_read_unlock(); 149 150 out: 151 __this_cpu_dec(bpf_prog_active); 152 153 return ret; 154 } 155 156 #ifdef CONFIG_BPF_KPROBE_OVERRIDE 157 BPF_CALL_2(bpf_override_return, struct pt_regs *, regs, unsigned long, rc) 158 { 159 regs_set_return_value(regs, rc); 160 override_function_with_return(regs); 161 return 0; 162 } 163 164 static const struct bpf_func_proto bpf_override_return_proto = { 165 .func = bpf_override_return, 166 .gpl_only = true, 167 .ret_type = RET_INTEGER, 168 .arg1_type = ARG_PTR_TO_CTX, 169 .arg2_type = ARG_ANYTHING, 170 }; 171 #endif 172 173 static __always_inline int 174 bpf_probe_read_user_common(void *dst, u32 size, const void __user *unsafe_ptr) 175 { 176 int ret; 177 178 ret = copy_from_user_nofault(dst, unsafe_ptr, size); 179 if (unlikely(ret < 0)) 180 memset(dst, 0, size); 181 return ret; 182 } 183 184 BPF_CALL_3(bpf_probe_read_user, void *, dst, u32, size, 185 const void __user *, unsafe_ptr) 186 { 187 return bpf_probe_read_user_common(dst, size, unsafe_ptr); 188 } 189 190 const struct bpf_func_proto bpf_probe_read_user_proto = { 191 .func = bpf_probe_read_user, 192 .gpl_only = true, 193 .ret_type = RET_INTEGER, 194 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 195 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 196 .arg3_type = ARG_ANYTHING, 197 }; 198 199 static __always_inline int 200 bpf_probe_read_user_str_common(void *dst, u32 size, 201 const void __user *unsafe_ptr) 202 { 203 int ret; 204 205 /* 206 * NB: We rely on strncpy_from_user() not copying junk past the NUL 207 * terminator into `dst`. 208 * 209 * strncpy_from_user() does long-sized strides in the fast path. If the 210 * strncpy does not mask out the bytes after the NUL in `unsafe_ptr`, 211 * then there could be junk after the NUL in `dst`. If user takes `dst` 212 * and keys a hash map with it, then semantically identical strings can 213 * occupy multiple entries in the map. 214 */ 215 ret = strncpy_from_user_nofault(dst, unsafe_ptr, size); 216 if (unlikely(ret < 0)) 217 memset(dst, 0, size); 218 return ret; 219 } 220 221 BPF_CALL_3(bpf_probe_read_user_str, void *, dst, u32, size, 222 const void __user *, unsafe_ptr) 223 { 224 return bpf_probe_read_user_str_common(dst, size, unsafe_ptr); 225 } 226 227 const struct bpf_func_proto bpf_probe_read_user_str_proto = { 228 .func = bpf_probe_read_user_str, 229 .gpl_only = true, 230 .ret_type = RET_INTEGER, 231 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 232 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 233 .arg3_type = ARG_ANYTHING, 234 }; 235 236 BPF_CALL_3(bpf_probe_read_kernel, void *, dst, u32, size, 237 const void *, unsafe_ptr) 238 { 239 return bpf_probe_read_kernel_common(dst, size, unsafe_ptr); 240 } 241 242 const struct bpf_func_proto bpf_probe_read_kernel_proto = { 243 .func = bpf_probe_read_kernel, 244 .gpl_only = true, 245 .ret_type = RET_INTEGER, 246 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 247 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 248 .arg3_type = ARG_ANYTHING, 249 }; 250 251 static __always_inline int 252 bpf_probe_read_kernel_str_common(void *dst, u32 size, const void *unsafe_ptr) 253 { 254 int ret; 255 256 /* 257 * The strncpy_from_kernel_nofault() call will likely not fill the 258 * entire buffer, but that's okay in this circumstance as we're probing 259 * arbitrary memory anyway similar to bpf_probe_read_*() and might 260 * as well probe the stack. Thus, memory is explicitly cleared 261 * only in error case, so that improper users ignoring return 262 * code altogether don't copy garbage; otherwise length of string 263 * is returned that can be used for bpf_perf_event_output() et al. 264 */ 265 ret = strncpy_from_kernel_nofault(dst, unsafe_ptr, size); 266 if (unlikely(ret < 0)) 267 memset(dst, 0, size); 268 return ret; 269 } 270 271 BPF_CALL_3(bpf_probe_read_kernel_str, void *, dst, u32, size, 272 const void *, unsafe_ptr) 273 { 274 return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr); 275 } 276 277 const struct bpf_func_proto bpf_probe_read_kernel_str_proto = { 278 .func = bpf_probe_read_kernel_str, 279 .gpl_only = true, 280 .ret_type = RET_INTEGER, 281 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 282 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 283 .arg3_type = ARG_ANYTHING, 284 }; 285 286 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 287 BPF_CALL_3(bpf_probe_read_compat, void *, dst, u32, size, 288 const void *, unsafe_ptr) 289 { 290 if ((unsigned long)unsafe_ptr < TASK_SIZE) { 291 return bpf_probe_read_user_common(dst, size, 292 (__force void __user *)unsafe_ptr); 293 } 294 return bpf_probe_read_kernel_common(dst, size, unsafe_ptr); 295 } 296 297 static const struct bpf_func_proto bpf_probe_read_compat_proto = { 298 .func = bpf_probe_read_compat, 299 .gpl_only = true, 300 .ret_type = RET_INTEGER, 301 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 302 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 303 .arg3_type = ARG_ANYTHING, 304 }; 305 306 BPF_CALL_3(bpf_probe_read_compat_str, void *, dst, u32, size, 307 const void *, unsafe_ptr) 308 { 309 if ((unsigned long)unsafe_ptr < TASK_SIZE) { 310 return bpf_probe_read_user_str_common(dst, size, 311 (__force void __user *)unsafe_ptr); 312 } 313 return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr); 314 } 315 316 static const struct bpf_func_proto bpf_probe_read_compat_str_proto = { 317 .func = bpf_probe_read_compat_str, 318 .gpl_only = true, 319 .ret_type = RET_INTEGER, 320 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 321 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 322 .arg3_type = ARG_ANYTHING, 323 }; 324 #endif /* CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE */ 325 326 BPF_CALL_3(bpf_probe_write_user, void __user *, unsafe_ptr, const void *, src, 327 u32, size) 328 { 329 /* 330 * Ensure we're in user context which is safe for the helper to 331 * run. This helper has no business in a kthread. 332 * 333 * access_ok() should prevent writing to non-user memory, but in 334 * some situations (nommu, temporary switch, etc) access_ok() does 335 * not provide enough validation, hence the check on KERNEL_DS. 336 * 337 * nmi_uaccess_okay() ensures the probe is not run in an interim 338 * state, when the task or mm are switched. This is specifically 339 * required to prevent the use of temporary mm. 340 */ 341 342 if (unlikely(in_interrupt() || 343 current->flags & (PF_KTHREAD | PF_EXITING))) 344 return -EPERM; 345 if (unlikely(!nmi_uaccess_okay())) 346 return -EPERM; 347 348 return copy_to_user_nofault(unsafe_ptr, src, size); 349 } 350 351 static const struct bpf_func_proto bpf_probe_write_user_proto = { 352 .func = bpf_probe_write_user, 353 .gpl_only = true, 354 .ret_type = RET_INTEGER, 355 .arg1_type = ARG_ANYTHING, 356 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 357 .arg3_type = ARG_CONST_SIZE, 358 }; 359 360 #define MAX_TRACE_PRINTK_VARARGS 3 361 #define BPF_TRACE_PRINTK_SIZE 1024 362 363 BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1, 364 u64, arg2, u64, arg3) 365 { 366 u64 args[MAX_TRACE_PRINTK_VARARGS] = { arg1, arg2, arg3 }; 367 struct bpf_bprintf_data data = { 368 .get_bin_args = true, 369 .get_buf = true, 370 }; 371 int ret; 372 373 ret = bpf_bprintf_prepare(fmt, fmt_size, args, 374 MAX_TRACE_PRINTK_VARARGS, &data); 375 if (ret < 0) 376 return ret; 377 378 ret = bstr_printf(data.buf, MAX_BPRINTF_BUF, fmt, data.bin_args); 379 380 trace_bpf_trace_printk(data.buf); 381 382 bpf_bprintf_cleanup(&data); 383 384 return ret; 385 } 386 387 static const struct bpf_func_proto bpf_trace_printk_proto = { 388 .func = bpf_trace_printk, 389 .gpl_only = true, 390 .ret_type = RET_INTEGER, 391 .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY, 392 .arg2_type = ARG_CONST_SIZE, 393 }; 394 395 static void __set_printk_clr_event(struct work_struct *work) 396 { 397 /* 398 * This program might be calling bpf_trace_printk, 399 * so enable the associated bpf_trace/bpf_trace_printk event. 400 * Repeat this each time as it is possible a user has 401 * disabled bpf_trace_printk events. By loading a program 402 * calling bpf_trace_printk() however the user has expressed 403 * the intent to see such events. 404 */ 405 if (trace_set_clr_event("bpf_trace", "bpf_trace_printk", 1)) 406 pr_warn_ratelimited("could not enable bpf_trace_printk events"); 407 } 408 static DECLARE_WORK(set_printk_work, __set_printk_clr_event); 409 410 const struct bpf_func_proto *bpf_get_trace_printk_proto(void) 411 { 412 schedule_work(&set_printk_work); 413 return &bpf_trace_printk_proto; 414 } 415 416 BPF_CALL_4(bpf_trace_vprintk, char *, fmt, u32, fmt_size, const void *, args, 417 u32, data_len) 418 { 419 struct bpf_bprintf_data data = { 420 .get_bin_args = true, 421 .get_buf = true, 422 }; 423 int ret, num_args; 424 425 if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 || 426 (data_len && !args)) 427 return -EINVAL; 428 num_args = data_len / 8; 429 430 ret = bpf_bprintf_prepare(fmt, fmt_size, args, num_args, &data); 431 if (ret < 0) 432 return ret; 433 434 ret = bstr_printf(data.buf, MAX_BPRINTF_BUF, fmt, data.bin_args); 435 436 trace_bpf_trace_printk(data.buf); 437 438 bpf_bprintf_cleanup(&data); 439 440 return ret; 441 } 442 443 static const struct bpf_func_proto bpf_trace_vprintk_proto = { 444 .func = bpf_trace_vprintk, 445 .gpl_only = true, 446 .ret_type = RET_INTEGER, 447 .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY, 448 .arg2_type = ARG_CONST_SIZE, 449 .arg3_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY, 450 .arg4_type = ARG_CONST_SIZE_OR_ZERO, 451 }; 452 453 const struct bpf_func_proto *bpf_get_trace_vprintk_proto(void) 454 { 455 schedule_work(&set_printk_work); 456 return &bpf_trace_vprintk_proto; 457 } 458 459 BPF_CALL_5(bpf_seq_printf, struct seq_file *, m, char *, fmt, u32, fmt_size, 460 const void *, args, u32, data_len) 461 { 462 struct bpf_bprintf_data data = { 463 .get_bin_args = true, 464 }; 465 int err, num_args; 466 467 if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 || 468 (data_len && !args)) 469 return -EINVAL; 470 num_args = data_len / 8; 471 472 err = bpf_bprintf_prepare(fmt, fmt_size, args, num_args, &data); 473 if (err < 0) 474 return err; 475 476 seq_bprintf(m, fmt, data.bin_args); 477 478 bpf_bprintf_cleanup(&data); 479 480 return seq_has_overflowed(m) ? -EOVERFLOW : 0; 481 } 482 483 BTF_ID_LIST_SINGLE(btf_seq_file_ids, struct, seq_file) 484 485 static const struct bpf_func_proto bpf_seq_printf_proto = { 486 .func = bpf_seq_printf, 487 .gpl_only = true, 488 .ret_type = RET_INTEGER, 489 .arg1_type = ARG_PTR_TO_BTF_ID, 490 .arg1_btf_id = &btf_seq_file_ids[0], 491 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 492 .arg3_type = ARG_CONST_SIZE, 493 .arg4_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY, 494 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 495 }; 496 497 BPF_CALL_3(bpf_seq_write, struct seq_file *, m, const void *, data, u32, len) 498 { 499 return seq_write(m, data, len) ? -EOVERFLOW : 0; 500 } 501 502 static const struct bpf_func_proto bpf_seq_write_proto = { 503 .func = bpf_seq_write, 504 .gpl_only = true, 505 .ret_type = RET_INTEGER, 506 .arg1_type = ARG_PTR_TO_BTF_ID, 507 .arg1_btf_id = &btf_seq_file_ids[0], 508 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 509 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 510 }; 511 512 BPF_CALL_4(bpf_seq_printf_btf, struct seq_file *, m, struct btf_ptr *, ptr, 513 u32, btf_ptr_size, u64, flags) 514 { 515 const struct btf *btf; 516 s32 btf_id; 517 int ret; 518 519 ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id); 520 if (ret) 521 return ret; 522 523 return btf_type_seq_show_flags(btf, btf_id, ptr->ptr, m, flags); 524 } 525 526 static const struct bpf_func_proto bpf_seq_printf_btf_proto = { 527 .func = bpf_seq_printf_btf, 528 .gpl_only = true, 529 .ret_type = RET_INTEGER, 530 .arg1_type = ARG_PTR_TO_BTF_ID, 531 .arg1_btf_id = &btf_seq_file_ids[0], 532 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 533 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 534 .arg4_type = ARG_ANYTHING, 535 }; 536 537 static __always_inline int 538 get_map_perf_counter(struct bpf_map *map, u64 flags, 539 u64 *value, u64 *enabled, u64 *running) 540 { 541 struct bpf_array *array = container_of(map, struct bpf_array, map); 542 unsigned int cpu = smp_processor_id(); 543 u64 index = flags & BPF_F_INDEX_MASK; 544 struct bpf_event_entry *ee; 545 546 if (unlikely(flags & ~(BPF_F_INDEX_MASK))) 547 return -EINVAL; 548 if (index == BPF_F_CURRENT_CPU) 549 index = cpu; 550 if (unlikely(index >= array->map.max_entries)) 551 return -E2BIG; 552 553 ee = READ_ONCE(array->ptrs[index]); 554 if (!ee) 555 return -ENOENT; 556 557 return perf_event_read_local(ee->event, value, enabled, running); 558 } 559 560 BPF_CALL_2(bpf_perf_event_read, struct bpf_map *, map, u64, flags) 561 { 562 u64 value = 0; 563 int err; 564 565 err = get_map_perf_counter(map, flags, &value, NULL, NULL); 566 /* 567 * this api is ugly since we miss [-22..-2] range of valid 568 * counter values, but that's uapi 569 */ 570 if (err) 571 return err; 572 return value; 573 } 574 575 static const struct bpf_func_proto bpf_perf_event_read_proto = { 576 .func = bpf_perf_event_read, 577 .gpl_only = true, 578 .ret_type = RET_INTEGER, 579 .arg1_type = ARG_CONST_MAP_PTR, 580 .arg2_type = ARG_ANYTHING, 581 }; 582 583 BPF_CALL_4(bpf_perf_event_read_value, struct bpf_map *, map, u64, flags, 584 struct bpf_perf_event_value *, buf, u32, size) 585 { 586 int err = -EINVAL; 587 588 if (unlikely(size != sizeof(struct bpf_perf_event_value))) 589 goto clear; 590 err = get_map_perf_counter(map, flags, &buf->counter, &buf->enabled, 591 &buf->running); 592 if (unlikely(err)) 593 goto clear; 594 return 0; 595 clear: 596 memset(buf, 0, size); 597 return err; 598 } 599 600 static const struct bpf_func_proto bpf_perf_event_read_value_proto = { 601 .func = bpf_perf_event_read_value, 602 .gpl_only = true, 603 .ret_type = RET_INTEGER, 604 .arg1_type = ARG_CONST_MAP_PTR, 605 .arg2_type = ARG_ANYTHING, 606 .arg3_type = ARG_PTR_TO_UNINIT_MEM, 607 .arg4_type = ARG_CONST_SIZE, 608 }; 609 610 const struct bpf_func_proto *bpf_get_perf_event_read_value_proto(void) 611 { 612 return &bpf_perf_event_read_value_proto; 613 } 614 615 static __always_inline u64 616 __bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map, 617 u64 flags, struct perf_raw_record *raw, 618 struct perf_sample_data *sd) 619 { 620 struct bpf_array *array = container_of(map, struct bpf_array, map); 621 unsigned int cpu = smp_processor_id(); 622 u64 index = flags & BPF_F_INDEX_MASK; 623 struct bpf_event_entry *ee; 624 struct perf_event *event; 625 626 if (index == BPF_F_CURRENT_CPU) 627 index = cpu; 628 if (unlikely(index >= array->map.max_entries)) 629 return -E2BIG; 630 631 ee = READ_ONCE(array->ptrs[index]); 632 if (!ee) 633 return -ENOENT; 634 635 event = ee->event; 636 if (unlikely(event->attr.type != PERF_TYPE_SOFTWARE || 637 event->attr.config != PERF_COUNT_SW_BPF_OUTPUT)) 638 return -EINVAL; 639 640 if (unlikely(event->oncpu != cpu)) 641 return -EOPNOTSUPP; 642 643 perf_sample_save_raw_data(sd, event, raw); 644 645 return perf_event_output(event, sd, regs); 646 } 647 648 /* 649 * Support executing tracepoints in normal, irq, and nmi context that each call 650 * bpf_perf_event_output 651 */ 652 struct bpf_trace_sample_data { 653 struct perf_sample_data sds[3]; 654 }; 655 656 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_trace_sds); 657 static DEFINE_PER_CPU(int, bpf_trace_nest_level); 658 BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map, 659 u64, flags, void *, data, u64, size) 660 { 661 struct bpf_trace_sample_data *sds; 662 struct perf_raw_record raw = { 663 .frag = { 664 .size = size, 665 .data = data, 666 }, 667 }; 668 struct perf_sample_data *sd; 669 int nest_level, err; 670 671 preempt_disable(); 672 sds = this_cpu_ptr(&bpf_trace_sds); 673 nest_level = this_cpu_inc_return(bpf_trace_nest_level); 674 675 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(sds->sds))) { 676 err = -EBUSY; 677 goto out; 678 } 679 680 sd = &sds->sds[nest_level - 1]; 681 682 if (unlikely(flags & ~(BPF_F_INDEX_MASK))) { 683 err = -EINVAL; 684 goto out; 685 } 686 687 perf_sample_data_init(sd, 0, 0); 688 689 err = __bpf_perf_event_output(regs, map, flags, &raw, sd); 690 out: 691 this_cpu_dec(bpf_trace_nest_level); 692 preempt_enable(); 693 return err; 694 } 695 696 static const struct bpf_func_proto bpf_perf_event_output_proto = { 697 .func = bpf_perf_event_output, 698 .gpl_only = true, 699 .ret_type = RET_INTEGER, 700 .arg1_type = ARG_PTR_TO_CTX, 701 .arg2_type = ARG_CONST_MAP_PTR, 702 .arg3_type = ARG_ANYTHING, 703 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, 704 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 705 }; 706 707 static DEFINE_PER_CPU(int, bpf_event_output_nest_level); 708 struct bpf_nested_pt_regs { 709 struct pt_regs regs[3]; 710 }; 711 static DEFINE_PER_CPU(struct bpf_nested_pt_regs, bpf_pt_regs); 712 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_misc_sds); 713 714 u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size, 715 void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy) 716 { 717 struct perf_raw_frag frag = { 718 .copy = ctx_copy, 719 .size = ctx_size, 720 .data = ctx, 721 }; 722 struct perf_raw_record raw = { 723 .frag = { 724 { 725 .next = ctx_size ? &frag : NULL, 726 }, 727 .size = meta_size, 728 .data = meta, 729 }, 730 }; 731 struct perf_sample_data *sd; 732 struct pt_regs *regs; 733 int nest_level; 734 u64 ret; 735 736 preempt_disable(); 737 nest_level = this_cpu_inc_return(bpf_event_output_nest_level); 738 739 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(bpf_misc_sds.sds))) { 740 ret = -EBUSY; 741 goto out; 742 } 743 sd = this_cpu_ptr(&bpf_misc_sds.sds[nest_level - 1]); 744 regs = this_cpu_ptr(&bpf_pt_regs.regs[nest_level - 1]); 745 746 perf_fetch_caller_regs(regs); 747 perf_sample_data_init(sd, 0, 0); 748 749 ret = __bpf_perf_event_output(regs, map, flags, &raw, sd); 750 out: 751 this_cpu_dec(bpf_event_output_nest_level); 752 preempt_enable(); 753 return ret; 754 } 755 756 BPF_CALL_0(bpf_get_current_task) 757 { 758 return (long) current; 759 } 760 761 const struct bpf_func_proto bpf_get_current_task_proto = { 762 .func = bpf_get_current_task, 763 .gpl_only = true, 764 .ret_type = RET_INTEGER, 765 }; 766 767 BPF_CALL_0(bpf_get_current_task_btf) 768 { 769 return (unsigned long) current; 770 } 771 772 const struct bpf_func_proto bpf_get_current_task_btf_proto = { 773 .func = bpf_get_current_task_btf, 774 .gpl_only = true, 775 .ret_type = RET_PTR_TO_BTF_ID_TRUSTED, 776 .ret_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK], 777 }; 778 779 BPF_CALL_1(bpf_task_pt_regs, struct task_struct *, task) 780 { 781 return (unsigned long) task_pt_regs(task); 782 } 783 784 BTF_ID_LIST(bpf_task_pt_regs_ids) 785 BTF_ID(struct, pt_regs) 786 787 const struct bpf_func_proto bpf_task_pt_regs_proto = { 788 .func = bpf_task_pt_regs, 789 .gpl_only = true, 790 .arg1_type = ARG_PTR_TO_BTF_ID, 791 .arg1_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK], 792 .ret_type = RET_PTR_TO_BTF_ID, 793 .ret_btf_id = &bpf_task_pt_regs_ids[0], 794 }; 795 796 struct send_signal_irq_work { 797 struct irq_work irq_work; 798 struct task_struct *task; 799 u32 sig; 800 enum pid_type type; 801 bool has_siginfo; 802 struct kernel_siginfo info; 803 }; 804 805 static DEFINE_PER_CPU(struct send_signal_irq_work, send_signal_work); 806 807 static void do_bpf_send_signal(struct irq_work *entry) 808 { 809 struct send_signal_irq_work *work; 810 struct kernel_siginfo *siginfo; 811 812 work = container_of(entry, struct send_signal_irq_work, irq_work); 813 siginfo = work->has_siginfo ? &work->info : SEND_SIG_PRIV; 814 815 group_send_sig_info(work->sig, siginfo, work->task, work->type); 816 put_task_struct(work->task); 817 } 818 819 static int bpf_send_signal_common(u32 sig, enum pid_type type, struct task_struct *task, u64 value) 820 { 821 struct send_signal_irq_work *work = NULL; 822 struct kernel_siginfo info; 823 struct kernel_siginfo *siginfo; 824 825 if (!task) { 826 task = current; 827 siginfo = SEND_SIG_PRIV; 828 } else { 829 clear_siginfo(&info); 830 info.si_signo = sig; 831 info.si_errno = 0; 832 info.si_code = SI_KERNEL; 833 info.si_pid = 0; 834 info.si_uid = 0; 835 info.si_value.sival_ptr = (void *)(unsigned long)value; 836 siginfo = &info; 837 } 838 839 /* Similar to bpf_probe_write_user, task needs to be 840 * in a sound condition and kernel memory access be 841 * permitted in order to send signal to the current 842 * task. 843 */ 844 if (unlikely(task->flags & (PF_KTHREAD | PF_EXITING))) 845 return -EPERM; 846 if (unlikely(!nmi_uaccess_okay())) 847 return -EPERM; 848 /* Task should not be pid=1 to avoid kernel panic. */ 849 if (unlikely(is_global_init(task))) 850 return -EPERM; 851 852 if (preempt_count() != 0 || irqs_disabled()) { 853 /* Do an early check on signal validity. Otherwise, 854 * the error is lost in deferred irq_work. 855 */ 856 if (unlikely(!valid_signal(sig))) 857 return -EINVAL; 858 859 work = this_cpu_ptr(&send_signal_work); 860 if (irq_work_is_busy(&work->irq_work)) 861 return -EBUSY; 862 863 /* Add the current task, which is the target of sending signal, 864 * to the irq_work. The current task may change when queued 865 * irq works get executed. 866 */ 867 work->task = get_task_struct(task); 868 work->has_siginfo = siginfo == &info; 869 if (work->has_siginfo) 870 copy_siginfo(&work->info, &info); 871 work->sig = sig; 872 work->type = type; 873 irq_work_queue(&work->irq_work); 874 return 0; 875 } 876 877 return group_send_sig_info(sig, siginfo, task, type); 878 } 879 880 BPF_CALL_1(bpf_send_signal, u32, sig) 881 { 882 return bpf_send_signal_common(sig, PIDTYPE_TGID, NULL, 0); 883 } 884 885 static const struct bpf_func_proto bpf_send_signal_proto = { 886 .func = bpf_send_signal, 887 .gpl_only = false, 888 .ret_type = RET_INTEGER, 889 .arg1_type = ARG_ANYTHING, 890 }; 891 892 BPF_CALL_1(bpf_send_signal_thread, u32, sig) 893 { 894 return bpf_send_signal_common(sig, PIDTYPE_PID, NULL, 0); 895 } 896 897 static const struct bpf_func_proto bpf_send_signal_thread_proto = { 898 .func = bpf_send_signal_thread, 899 .gpl_only = false, 900 .ret_type = RET_INTEGER, 901 .arg1_type = ARG_ANYTHING, 902 }; 903 904 BPF_CALL_3(bpf_d_path, struct path *, path, char *, buf, u32, sz) 905 { 906 struct path copy; 907 long len; 908 char *p; 909 910 if (!sz) 911 return 0; 912 913 /* 914 * The path pointer is verified as trusted and safe to use, 915 * but let's double check it's valid anyway to workaround 916 * potentially broken verifier. 917 */ 918 len = copy_from_kernel_nofault(©, path, sizeof(*path)); 919 if (len < 0) 920 return len; 921 922 p = d_path(©, buf, sz); 923 if (IS_ERR(p)) { 924 len = PTR_ERR(p); 925 } else { 926 len = buf + sz - p; 927 memmove(buf, p, len); 928 } 929 930 return len; 931 } 932 933 BTF_SET_START(btf_allowlist_d_path) 934 #ifdef CONFIG_SECURITY 935 BTF_ID(func, security_file_permission) 936 BTF_ID(func, security_inode_getattr) 937 BTF_ID(func, security_file_open) 938 #endif 939 #ifdef CONFIG_SECURITY_PATH 940 BTF_ID(func, security_path_truncate) 941 #endif 942 BTF_ID(func, vfs_truncate) 943 BTF_ID(func, vfs_fallocate) 944 BTF_ID(func, dentry_open) 945 BTF_ID(func, vfs_getattr) 946 BTF_ID(func, filp_close) 947 BTF_SET_END(btf_allowlist_d_path) 948 949 static bool bpf_d_path_allowed(const struct bpf_prog *prog) 950 { 951 if (prog->type == BPF_PROG_TYPE_TRACING && 952 prog->expected_attach_type == BPF_TRACE_ITER) 953 return true; 954 955 if (prog->type == BPF_PROG_TYPE_LSM) 956 return bpf_lsm_is_sleepable_hook(prog->aux->attach_btf_id); 957 958 return btf_id_set_contains(&btf_allowlist_d_path, 959 prog->aux->attach_btf_id); 960 } 961 962 BTF_ID_LIST_SINGLE(bpf_d_path_btf_ids, struct, path) 963 964 static const struct bpf_func_proto bpf_d_path_proto = { 965 .func = bpf_d_path, 966 .gpl_only = false, 967 .ret_type = RET_INTEGER, 968 .arg1_type = ARG_PTR_TO_BTF_ID, 969 .arg1_btf_id = &bpf_d_path_btf_ids[0], 970 .arg2_type = ARG_PTR_TO_MEM, 971 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 972 .allowed = bpf_d_path_allowed, 973 }; 974 975 #define BTF_F_ALL (BTF_F_COMPACT | BTF_F_NONAME | \ 976 BTF_F_PTR_RAW | BTF_F_ZERO) 977 978 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size, 979 u64 flags, const struct btf **btf, 980 s32 *btf_id) 981 { 982 const struct btf_type *t; 983 984 if (unlikely(flags & ~(BTF_F_ALL))) 985 return -EINVAL; 986 987 if (btf_ptr_size != sizeof(struct btf_ptr)) 988 return -EINVAL; 989 990 *btf = bpf_get_btf_vmlinux(); 991 992 if (IS_ERR_OR_NULL(*btf)) 993 return IS_ERR(*btf) ? PTR_ERR(*btf) : -EINVAL; 994 995 if (ptr->type_id > 0) 996 *btf_id = ptr->type_id; 997 else 998 return -EINVAL; 999 1000 if (*btf_id > 0) 1001 t = btf_type_by_id(*btf, *btf_id); 1002 if (*btf_id <= 0 || !t) 1003 return -ENOENT; 1004 1005 return 0; 1006 } 1007 1008 BPF_CALL_5(bpf_snprintf_btf, char *, str, u32, str_size, struct btf_ptr *, ptr, 1009 u32, btf_ptr_size, u64, flags) 1010 { 1011 const struct btf *btf; 1012 s32 btf_id; 1013 int ret; 1014 1015 ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id); 1016 if (ret) 1017 return ret; 1018 1019 return btf_type_snprintf_show(btf, btf_id, ptr->ptr, str, str_size, 1020 flags); 1021 } 1022 1023 const struct bpf_func_proto bpf_snprintf_btf_proto = { 1024 .func = bpf_snprintf_btf, 1025 .gpl_only = false, 1026 .ret_type = RET_INTEGER, 1027 .arg1_type = ARG_PTR_TO_MEM, 1028 .arg2_type = ARG_CONST_SIZE, 1029 .arg3_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1030 .arg4_type = ARG_CONST_SIZE, 1031 .arg5_type = ARG_ANYTHING, 1032 }; 1033 1034 BPF_CALL_1(bpf_get_func_ip_tracing, void *, ctx) 1035 { 1036 /* This helper call is inlined by verifier. */ 1037 return ((u64 *)ctx)[-2]; 1038 } 1039 1040 static const struct bpf_func_proto bpf_get_func_ip_proto_tracing = { 1041 .func = bpf_get_func_ip_tracing, 1042 .gpl_only = true, 1043 .ret_type = RET_INTEGER, 1044 .arg1_type = ARG_PTR_TO_CTX, 1045 }; 1046 1047 #ifdef CONFIG_X86_KERNEL_IBT 1048 static unsigned long get_entry_ip(unsigned long fentry_ip) 1049 { 1050 u32 instr; 1051 1052 /* We want to be extra safe in case entry ip is on the page edge, 1053 * but otherwise we need to avoid get_kernel_nofault()'s overhead. 1054 */ 1055 if ((fentry_ip & ~PAGE_MASK) < ENDBR_INSN_SIZE) { 1056 if (get_kernel_nofault(instr, (u32 *)(fentry_ip - ENDBR_INSN_SIZE))) 1057 return fentry_ip; 1058 } else { 1059 instr = *(u32 *)(fentry_ip - ENDBR_INSN_SIZE); 1060 } 1061 if (is_endbr(instr)) 1062 fentry_ip -= ENDBR_INSN_SIZE; 1063 return fentry_ip; 1064 } 1065 #else 1066 #define get_entry_ip(fentry_ip) fentry_ip 1067 #endif 1068 1069 BPF_CALL_1(bpf_get_func_ip_kprobe, struct pt_regs *, regs) 1070 { 1071 struct bpf_trace_run_ctx *run_ctx __maybe_unused; 1072 struct kprobe *kp; 1073 1074 #ifdef CONFIG_UPROBES 1075 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); 1076 if (run_ctx->is_uprobe) 1077 return ((struct uprobe_dispatch_data *)current->utask->vaddr)->bp_addr; 1078 #endif 1079 1080 kp = kprobe_running(); 1081 1082 if (!kp || !(kp->flags & KPROBE_FLAG_ON_FUNC_ENTRY)) 1083 return 0; 1084 1085 return get_entry_ip((uintptr_t)kp->addr); 1086 } 1087 1088 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe = { 1089 .func = bpf_get_func_ip_kprobe, 1090 .gpl_only = true, 1091 .ret_type = RET_INTEGER, 1092 .arg1_type = ARG_PTR_TO_CTX, 1093 }; 1094 1095 BPF_CALL_1(bpf_get_func_ip_kprobe_multi, struct pt_regs *, regs) 1096 { 1097 return bpf_kprobe_multi_entry_ip(current->bpf_ctx); 1098 } 1099 1100 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe_multi = { 1101 .func = bpf_get_func_ip_kprobe_multi, 1102 .gpl_only = false, 1103 .ret_type = RET_INTEGER, 1104 .arg1_type = ARG_PTR_TO_CTX, 1105 }; 1106 1107 BPF_CALL_1(bpf_get_attach_cookie_kprobe_multi, struct pt_regs *, regs) 1108 { 1109 return bpf_kprobe_multi_cookie(current->bpf_ctx); 1110 } 1111 1112 static const struct bpf_func_proto bpf_get_attach_cookie_proto_kmulti = { 1113 .func = bpf_get_attach_cookie_kprobe_multi, 1114 .gpl_only = false, 1115 .ret_type = RET_INTEGER, 1116 .arg1_type = ARG_PTR_TO_CTX, 1117 }; 1118 1119 BPF_CALL_1(bpf_get_func_ip_uprobe_multi, struct pt_regs *, regs) 1120 { 1121 return bpf_uprobe_multi_entry_ip(current->bpf_ctx); 1122 } 1123 1124 static const struct bpf_func_proto bpf_get_func_ip_proto_uprobe_multi = { 1125 .func = bpf_get_func_ip_uprobe_multi, 1126 .gpl_only = false, 1127 .ret_type = RET_INTEGER, 1128 .arg1_type = ARG_PTR_TO_CTX, 1129 }; 1130 1131 BPF_CALL_1(bpf_get_attach_cookie_uprobe_multi, struct pt_regs *, regs) 1132 { 1133 return bpf_uprobe_multi_cookie(current->bpf_ctx); 1134 } 1135 1136 static const struct bpf_func_proto bpf_get_attach_cookie_proto_umulti = { 1137 .func = bpf_get_attach_cookie_uprobe_multi, 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_trace, void *, ctx) 1144 { 1145 struct bpf_trace_run_ctx *run_ctx; 1146 1147 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); 1148 return run_ctx->bpf_cookie; 1149 } 1150 1151 static const struct bpf_func_proto bpf_get_attach_cookie_proto_trace = { 1152 .func = bpf_get_attach_cookie_trace, 1153 .gpl_only = false, 1154 .ret_type = RET_INTEGER, 1155 .arg1_type = ARG_PTR_TO_CTX, 1156 }; 1157 1158 BPF_CALL_1(bpf_get_attach_cookie_pe, struct bpf_perf_event_data_kern *, ctx) 1159 { 1160 return ctx->event->bpf_cookie; 1161 } 1162 1163 static const struct bpf_func_proto bpf_get_attach_cookie_proto_pe = { 1164 .func = bpf_get_attach_cookie_pe, 1165 .gpl_only = false, 1166 .ret_type = RET_INTEGER, 1167 .arg1_type = ARG_PTR_TO_CTX, 1168 }; 1169 1170 BPF_CALL_1(bpf_get_attach_cookie_tracing, void *, ctx) 1171 { 1172 struct bpf_trace_run_ctx *run_ctx; 1173 1174 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); 1175 return run_ctx->bpf_cookie; 1176 } 1177 1178 static const struct bpf_func_proto bpf_get_attach_cookie_proto_tracing = { 1179 .func = bpf_get_attach_cookie_tracing, 1180 .gpl_only = false, 1181 .ret_type = RET_INTEGER, 1182 .arg1_type = ARG_PTR_TO_CTX, 1183 }; 1184 1185 BPF_CALL_3(bpf_get_branch_snapshot, void *, buf, u32, size, u64, flags) 1186 { 1187 static const u32 br_entry_size = sizeof(struct perf_branch_entry); 1188 u32 entry_cnt = size / br_entry_size; 1189 1190 entry_cnt = static_call(perf_snapshot_branch_stack)(buf, entry_cnt); 1191 1192 if (unlikely(flags)) 1193 return -EINVAL; 1194 1195 if (!entry_cnt) 1196 return -ENOENT; 1197 1198 return entry_cnt * br_entry_size; 1199 } 1200 1201 static const struct bpf_func_proto bpf_get_branch_snapshot_proto = { 1202 .func = bpf_get_branch_snapshot, 1203 .gpl_only = true, 1204 .ret_type = RET_INTEGER, 1205 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 1206 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 1207 }; 1208 1209 BPF_CALL_3(get_func_arg, void *, ctx, u32, n, u64 *, value) 1210 { 1211 /* This helper call is inlined by verifier. */ 1212 u64 nr_args = ((u64 *)ctx)[-1]; 1213 1214 if ((u64) n >= nr_args) 1215 return -EINVAL; 1216 *value = ((u64 *)ctx)[n]; 1217 return 0; 1218 } 1219 1220 static const struct bpf_func_proto bpf_get_func_arg_proto = { 1221 .func = get_func_arg, 1222 .ret_type = RET_INTEGER, 1223 .arg1_type = ARG_PTR_TO_CTX, 1224 .arg2_type = ARG_ANYTHING, 1225 .arg3_type = ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED, 1226 .arg3_size = sizeof(u64), 1227 }; 1228 1229 BPF_CALL_2(get_func_ret, void *, ctx, u64 *, value) 1230 { 1231 /* This helper call is inlined by verifier. */ 1232 u64 nr_args = ((u64 *)ctx)[-1]; 1233 1234 *value = ((u64 *)ctx)[nr_args]; 1235 return 0; 1236 } 1237 1238 static const struct bpf_func_proto bpf_get_func_ret_proto = { 1239 .func = get_func_ret, 1240 .ret_type = RET_INTEGER, 1241 .arg1_type = ARG_PTR_TO_CTX, 1242 .arg2_type = ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED, 1243 .arg2_size = sizeof(u64), 1244 }; 1245 1246 BPF_CALL_1(get_func_arg_cnt, void *, ctx) 1247 { 1248 /* This helper call is inlined by verifier. */ 1249 return ((u64 *)ctx)[-1]; 1250 } 1251 1252 static const struct bpf_func_proto bpf_get_func_arg_cnt_proto = { 1253 .func = get_func_arg_cnt, 1254 .ret_type = RET_INTEGER, 1255 .arg1_type = ARG_PTR_TO_CTX, 1256 }; 1257 1258 #ifdef CONFIG_KEYS 1259 __bpf_kfunc_start_defs(); 1260 1261 /** 1262 * bpf_lookup_user_key - lookup a key by its serial 1263 * @serial: key handle serial number 1264 * @flags: lookup-specific flags 1265 * 1266 * Search a key with a given *serial* and the provided *flags*. 1267 * If found, increment the reference count of the key by one, and 1268 * return it in the bpf_key structure. 1269 * 1270 * The bpf_key structure must be passed to bpf_key_put() when done 1271 * with it, so that the key reference count is decremented and the 1272 * bpf_key structure is freed. 1273 * 1274 * Permission checks are deferred to the time the key is used by 1275 * one of the available key-specific kfuncs. 1276 * 1277 * Set *flags* with KEY_LOOKUP_CREATE, to attempt creating a requested 1278 * special keyring (e.g. session keyring), if it doesn't yet exist. 1279 * Set *flags* with KEY_LOOKUP_PARTIAL, to lookup a key without waiting 1280 * for the key construction, and to retrieve uninstantiated keys (keys 1281 * without data attached to them). 1282 * 1283 * Return: a bpf_key pointer with a valid key pointer if the key is found, a 1284 * NULL pointer otherwise. 1285 */ 1286 __bpf_kfunc struct bpf_key *bpf_lookup_user_key(u32 serial, u64 flags) 1287 { 1288 key_ref_t key_ref; 1289 struct bpf_key *bkey; 1290 1291 if (flags & ~KEY_LOOKUP_ALL) 1292 return NULL; 1293 1294 /* 1295 * Permission check is deferred until the key is used, as the 1296 * intent of the caller is unknown here. 1297 */ 1298 key_ref = lookup_user_key(serial, flags, KEY_DEFER_PERM_CHECK); 1299 if (IS_ERR(key_ref)) 1300 return NULL; 1301 1302 bkey = kmalloc(sizeof(*bkey), GFP_KERNEL); 1303 if (!bkey) { 1304 key_put(key_ref_to_ptr(key_ref)); 1305 return NULL; 1306 } 1307 1308 bkey->key = key_ref_to_ptr(key_ref); 1309 bkey->has_ref = true; 1310 1311 return bkey; 1312 } 1313 1314 /** 1315 * bpf_lookup_system_key - lookup a key by a system-defined ID 1316 * @id: key ID 1317 * 1318 * Obtain a bpf_key structure with a key pointer set to the passed key ID. 1319 * The key pointer is marked as invalid, to prevent bpf_key_put() from 1320 * attempting to decrement the key reference count on that pointer. The key 1321 * pointer set in such way is currently understood only by 1322 * verify_pkcs7_signature(). 1323 * 1324 * Set *id* to one of the values defined in include/linux/verification.h: 1325 * 0 for the primary keyring (immutable keyring of system keys); 1326 * VERIFY_USE_SECONDARY_KEYRING for both the primary and secondary keyring 1327 * (where keys can be added only if they are vouched for by existing keys 1328 * in those keyrings); VERIFY_USE_PLATFORM_KEYRING for the platform 1329 * keyring (primarily used by the integrity subsystem to verify a kexec'ed 1330 * kerned image and, possibly, the initramfs signature). 1331 * 1332 * Return: a bpf_key pointer with an invalid key pointer set from the 1333 * pre-determined ID on success, a NULL pointer otherwise 1334 */ 1335 __bpf_kfunc struct bpf_key *bpf_lookup_system_key(u64 id) 1336 { 1337 struct bpf_key *bkey; 1338 1339 if (system_keyring_id_check(id) < 0) 1340 return NULL; 1341 1342 bkey = kmalloc(sizeof(*bkey), GFP_ATOMIC); 1343 if (!bkey) 1344 return NULL; 1345 1346 bkey->key = (struct key *)(unsigned long)id; 1347 bkey->has_ref = false; 1348 1349 return bkey; 1350 } 1351 1352 /** 1353 * bpf_key_put - decrement key reference count if key is valid and free bpf_key 1354 * @bkey: bpf_key structure 1355 * 1356 * Decrement the reference count of the key inside *bkey*, if the pointer 1357 * is valid, and free *bkey*. 1358 */ 1359 __bpf_kfunc void bpf_key_put(struct bpf_key *bkey) 1360 { 1361 if (bkey->has_ref) 1362 key_put(bkey->key); 1363 1364 kfree(bkey); 1365 } 1366 1367 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION 1368 /** 1369 * bpf_verify_pkcs7_signature - verify a PKCS#7 signature 1370 * @data_p: data to verify 1371 * @sig_p: signature of the data 1372 * @trusted_keyring: keyring with keys trusted for signature verification 1373 * 1374 * Verify the PKCS#7 signature *sig_ptr* against the supplied *data_ptr* 1375 * with keys in a keyring referenced by *trusted_keyring*. 1376 * 1377 * Return: 0 on success, a negative value on error. 1378 */ 1379 __bpf_kfunc int bpf_verify_pkcs7_signature(struct bpf_dynptr *data_p, 1380 struct bpf_dynptr *sig_p, 1381 struct bpf_key *trusted_keyring) 1382 { 1383 struct bpf_dynptr_kern *data_ptr = (struct bpf_dynptr_kern *)data_p; 1384 struct bpf_dynptr_kern *sig_ptr = (struct bpf_dynptr_kern *)sig_p; 1385 const void *data, *sig; 1386 u32 data_len, sig_len; 1387 int ret; 1388 1389 if (trusted_keyring->has_ref) { 1390 /* 1391 * Do the permission check deferred in bpf_lookup_user_key(). 1392 * See bpf_lookup_user_key() for more details. 1393 * 1394 * A call to key_task_permission() here would be redundant, as 1395 * it is already done by keyring_search() called by 1396 * find_asymmetric_key(). 1397 */ 1398 ret = key_validate(trusted_keyring->key); 1399 if (ret < 0) 1400 return ret; 1401 } 1402 1403 data_len = __bpf_dynptr_size(data_ptr); 1404 data = __bpf_dynptr_data(data_ptr, data_len); 1405 sig_len = __bpf_dynptr_size(sig_ptr); 1406 sig = __bpf_dynptr_data(sig_ptr, sig_len); 1407 1408 return verify_pkcs7_signature(data, data_len, sig, sig_len, 1409 trusted_keyring->key, 1410 VERIFYING_UNSPECIFIED_SIGNATURE, NULL, 1411 NULL); 1412 } 1413 #endif /* CONFIG_SYSTEM_DATA_VERIFICATION */ 1414 1415 __bpf_kfunc_end_defs(); 1416 1417 BTF_KFUNCS_START(key_sig_kfunc_set) 1418 BTF_ID_FLAGS(func, bpf_lookup_user_key, KF_ACQUIRE | KF_RET_NULL | KF_SLEEPABLE) 1419 BTF_ID_FLAGS(func, bpf_lookup_system_key, KF_ACQUIRE | KF_RET_NULL) 1420 BTF_ID_FLAGS(func, bpf_key_put, KF_RELEASE) 1421 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION 1422 BTF_ID_FLAGS(func, bpf_verify_pkcs7_signature, KF_SLEEPABLE) 1423 #endif 1424 BTF_KFUNCS_END(key_sig_kfunc_set) 1425 1426 static const struct btf_kfunc_id_set bpf_key_sig_kfunc_set = { 1427 .owner = THIS_MODULE, 1428 .set = &key_sig_kfunc_set, 1429 }; 1430 1431 static int __init bpf_key_sig_kfuncs_init(void) 1432 { 1433 return register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, 1434 &bpf_key_sig_kfunc_set); 1435 } 1436 1437 late_initcall(bpf_key_sig_kfuncs_init); 1438 #endif /* CONFIG_KEYS */ 1439 1440 static const struct bpf_func_proto * 1441 bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1442 { 1443 const struct bpf_func_proto *func_proto; 1444 1445 switch (func_id) { 1446 case BPF_FUNC_map_lookup_elem: 1447 return &bpf_map_lookup_elem_proto; 1448 case BPF_FUNC_map_update_elem: 1449 return &bpf_map_update_elem_proto; 1450 case BPF_FUNC_map_delete_elem: 1451 return &bpf_map_delete_elem_proto; 1452 case BPF_FUNC_map_push_elem: 1453 return &bpf_map_push_elem_proto; 1454 case BPF_FUNC_map_pop_elem: 1455 return &bpf_map_pop_elem_proto; 1456 case BPF_FUNC_map_peek_elem: 1457 return &bpf_map_peek_elem_proto; 1458 case BPF_FUNC_map_lookup_percpu_elem: 1459 return &bpf_map_lookup_percpu_elem_proto; 1460 case BPF_FUNC_ktime_get_ns: 1461 return &bpf_ktime_get_ns_proto; 1462 case BPF_FUNC_ktime_get_boot_ns: 1463 return &bpf_ktime_get_boot_ns_proto; 1464 case BPF_FUNC_tail_call: 1465 return &bpf_tail_call_proto; 1466 case BPF_FUNC_get_current_task: 1467 return &bpf_get_current_task_proto; 1468 case BPF_FUNC_get_current_task_btf: 1469 return &bpf_get_current_task_btf_proto; 1470 case BPF_FUNC_task_pt_regs: 1471 return &bpf_task_pt_regs_proto; 1472 case BPF_FUNC_get_current_uid_gid: 1473 return &bpf_get_current_uid_gid_proto; 1474 case BPF_FUNC_get_current_comm: 1475 return &bpf_get_current_comm_proto; 1476 case BPF_FUNC_trace_printk: 1477 return bpf_get_trace_printk_proto(); 1478 case BPF_FUNC_get_smp_processor_id: 1479 return &bpf_get_smp_processor_id_proto; 1480 case BPF_FUNC_get_numa_node_id: 1481 return &bpf_get_numa_node_id_proto; 1482 case BPF_FUNC_perf_event_read: 1483 return &bpf_perf_event_read_proto; 1484 case BPF_FUNC_get_prandom_u32: 1485 return &bpf_get_prandom_u32_proto; 1486 case BPF_FUNC_probe_read_user: 1487 return &bpf_probe_read_user_proto; 1488 case BPF_FUNC_probe_read_kernel: 1489 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1490 NULL : &bpf_probe_read_kernel_proto; 1491 case BPF_FUNC_probe_read_user_str: 1492 return &bpf_probe_read_user_str_proto; 1493 case BPF_FUNC_probe_read_kernel_str: 1494 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1495 NULL : &bpf_probe_read_kernel_str_proto; 1496 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 1497 case BPF_FUNC_probe_read: 1498 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1499 NULL : &bpf_probe_read_compat_proto; 1500 case BPF_FUNC_probe_read_str: 1501 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1502 NULL : &bpf_probe_read_compat_str_proto; 1503 #endif 1504 #ifdef CONFIG_CGROUPS 1505 case BPF_FUNC_cgrp_storage_get: 1506 return &bpf_cgrp_storage_get_proto; 1507 case BPF_FUNC_cgrp_storage_delete: 1508 return &bpf_cgrp_storage_delete_proto; 1509 case BPF_FUNC_current_task_under_cgroup: 1510 return &bpf_current_task_under_cgroup_proto; 1511 #endif 1512 case BPF_FUNC_send_signal: 1513 return &bpf_send_signal_proto; 1514 case BPF_FUNC_send_signal_thread: 1515 return &bpf_send_signal_thread_proto; 1516 case BPF_FUNC_perf_event_read_value: 1517 return &bpf_perf_event_read_value_proto; 1518 case BPF_FUNC_ringbuf_output: 1519 return &bpf_ringbuf_output_proto; 1520 case BPF_FUNC_ringbuf_reserve: 1521 return &bpf_ringbuf_reserve_proto; 1522 case BPF_FUNC_ringbuf_submit: 1523 return &bpf_ringbuf_submit_proto; 1524 case BPF_FUNC_ringbuf_discard: 1525 return &bpf_ringbuf_discard_proto; 1526 case BPF_FUNC_ringbuf_query: 1527 return &bpf_ringbuf_query_proto; 1528 case BPF_FUNC_jiffies64: 1529 return &bpf_jiffies64_proto; 1530 case BPF_FUNC_get_task_stack: 1531 return prog->sleepable ? &bpf_get_task_stack_sleepable_proto 1532 : &bpf_get_task_stack_proto; 1533 case BPF_FUNC_copy_from_user: 1534 return &bpf_copy_from_user_proto; 1535 case BPF_FUNC_copy_from_user_task: 1536 return &bpf_copy_from_user_task_proto; 1537 case BPF_FUNC_snprintf_btf: 1538 return &bpf_snprintf_btf_proto; 1539 case BPF_FUNC_per_cpu_ptr: 1540 return &bpf_per_cpu_ptr_proto; 1541 case BPF_FUNC_this_cpu_ptr: 1542 return &bpf_this_cpu_ptr_proto; 1543 case BPF_FUNC_task_storage_get: 1544 if (bpf_prog_check_recur(prog)) 1545 return &bpf_task_storage_get_recur_proto; 1546 return &bpf_task_storage_get_proto; 1547 case BPF_FUNC_task_storage_delete: 1548 if (bpf_prog_check_recur(prog)) 1549 return &bpf_task_storage_delete_recur_proto; 1550 return &bpf_task_storage_delete_proto; 1551 case BPF_FUNC_for_each_map_elem: 1552 return &bpf_for_each_map_elem_proto; 1553 case BPF_FUNC_snprintf: 1554 return &bpf_snprintf_proto; 1555 case BPF_FUNC_get_func_ip: 1556 return &bpf_get_func_ip_proto_tracing; 1557 case BPF_FUNC_get_branch_snapshot: 1558 return &bpf_get_branch_snapshot_proto; 1559 case BPF_FUNC_find_vma: 1560 return &bpf_find_vma_proto; 1561 case BPF_FUNC_trace_vprintk: 1562 return bpf_get_trace_vprintk_proto(); 1563 default: 1564 break; 1565 } 1566 1567 func_proto = bpf_base_func_proto(func_id, prog); 1568 if (func_proto) 1569 return func_proto; 1570 1571 if (!bpf_token_capable(prog->aux->token, CAP_SYS_ADMIN)) 1572 return NULL; 1573 1574 switch (func_id) { 1575 case BPF_FUNC_probe_write_user: 1576 return security_locked_down(LOCKDOWN_BPF_WRITE_USER) < 0 ? 1577 NULL : &bpf_probe_write_user_proto; 1578 default: 1579 return NULL; 1580 } 1581 } 1582 1583 static bool is_kprobe_multi(const struct bpf_prog *prog) 1584 { 1585 return prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI || 1586 prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION; 1587 } 1588 1589 static inline bool is_kprobe_session(const struct bpf_prog *prog) 1590 { 1591 return prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION; 1592 } 1593 1594 static inline bool is_uprobe_multi(const struct bpf_prog *prog) 1595 { 1596 return prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI || 1597 prog->expected_attach_type == BPF_TRACE_UPROBE_SESSION; 1598 } 1599 1600 static inline bool is_uprobe_session(const struct bpf_prog *prog) 1601 { 1602 return prog->expected_attach_type == BPF_TRACE_UPROBE_SESSION; 1603 } 1604 1605 static const struct bpf_func_proto * 1606 kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1607 { 1608 switch (func_id) { 1609 case BPF_FUNC_perf_event_output: 1610 return &bpf_perf_event_output_proto; 1611 case BPF_FUNC_get_stackid: 1612 return &bpf_get_stackid_proto; 1613 case BPF_FUNC_get_stack: 1614 return prog->sleepable ? &bpf_get_stack_sleepable_proto : &bpf_get_stack_proto; 1615 #ifdef CONFIG_BPF_KPROBE_OVERRIDE 1616 case BPF_FUNC_override_return: 1617 return &bpf_override_return_proto; 1618 #endif 1619 case BPF_FUNC_get_func_ip: 1620 if (is_kprobe_multi(prog)) 1621 return &bpf_get_func_ip_proto_kprobe_multi; 1622 if (is_uprobe_multi(prog)) 1623 return &bpf_get_func_ip_proto_uprobe_multi; 1624 return &bpf_get_func_ip_proto_kprobe; 1625 case BPF_FUNC_get_attach_cookie: 1626 if (is_kprobe_multi(prog)) 1627 return &bpf_get_attach_cookie_proto_kmulti; 1628 if (is_uprobe_multi(prog)) 1629 return &bpf_get_attach_cookie_proto_umulti; 1630 return &bpf_get_attach_cookie_proto_trace; 1631 default: 1632 return bpf_tracing_func_proto(func_id, prog); 1633 } 1634 } 1635 1636 /* bpf+kprobe programs can access fields of 'struct pt_regs' */ 1637 static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type, 1638 const struct bpf_prog *prog, 1639 struct bpf_insn_access_aux *info) 1640 { 1641 if (off < 0 || off >= sizeof(struct pt_regs)) 1642 return false; 1643 if (type != BPF_READ) 1644 return false; 1645 if (off % size != 0) 1646 return false; 1647 /* 1648 * Assertion for 32 bit to make sure last 8 byte access 1649 * (BPF_DW) to the last 4 byte member is disallowed. 1650 */ 1651 if (off + size > sizeof(struct pt_regs)) 1652 return false; 1653 1654 return true; 1655 } 1656 1657 const struct bpf_verifier_ops kprobe_verifier_ops = { 1658 .get_func_proto = kprobe_prog_func_proto, 1659 .is_valid_access = kprobe_prog_is_valid_access, 1660 }; 1661 1662 const struct bpf_prog_ops kprobe_prog_ops = { 1663 }; 1664 1665 BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map, 1666 u64, flags, void *, data, u64, size) 1667 { 1668 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1669 1670 /* 1671 * r1 points to perf tracepoint buffer where first 8 bytes are hidden 1672 * from bpf program and contain a pointer to 'struct pt_regs'. Fetch it 1673 * from there and call the same bpf_perf_event_output() helper inline. 1674 */ 1675 return ____bpf_perf_event_output(regs, map, flags, data, size); 1676 } 1677 1678 static const struct bpf_func_proto bpf_perf_event_output_proto_tp = { 1679 .func = bpf_perf_event_output_tp, 1680 .gpl_only = true, 1681 .ret_type = RET_INTEGER, 1682 .arg1_type = ARG_PTR_TO_CTX, 1683 .arg2_type = ARG_CONST_MAP_PTR, 1684 .arg3_type = ARG_ANYTHING, 1685 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1686 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 1687 }; 1688 1689 BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map, 1690 u64, flags) 1691 { 1692 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1693 1694 /* 1695 * Same comment as in bpf_perf_event_output_tp(), only that this time 1696 * the other helper's function body cannot be inlined due to being 1697 * external, thus we need to call raw helper function. 1698 */ 1699 return bpf_get_stackid((unsigned long) regs, (unsigned long) map, 1700 flags, 0, 0); 1701 } 1702 1703 static const struct bpf_func_proto bpf_get_stackid_proto_tp = { 1704 .func = bpf_get_stackid_tp, 1705 .gpl_only = true, 1706 .ret_type = RET_INTEGER, 1707 .arg1_type = ARG_PTR_TO_CTX, 1708 .arg2_type = ARG_CONST_MAP_PTR, 1709 .arg3_type = ARG_ANYTHING, 1710 }; 1711 1712 BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size, 1713 u64, flags) 1714 { 1715 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1716 1717 return bpf_get_stack((unsigned long) regs, (unsigned long) buf, 1718 (unsigned long) size, flags, 0); 1719 } 1720 1721 static const struct bpf_func_proto bpf_get_stack_proto_tp = { 1722 .func = bpf_get_stack_tp, 1723 .gpl_only = true, 1724 .ret_type = RET_INTEGER, 1725 .arg1_type = ARG_PTR_TO_CTX, 1726 .arg2_type = ARG_PTR_TO_UNINIT_MEM, 1727 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1728 .arg4_type = ARG_ANYTHING, 1729 }; 1730 1731 static const struct bpf_func_proto * 1732 tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1733 { 1734 switch (func_id) { 1735 case BPF_FUNC_perf_event_output: 1736 return &bpf_perf_event_output_proto_tp; 1737 case BPF_FUNC_get_stackid: 1738 return &bpf_get_stackid_proto_tp; 1739 case BPF_FUNC_get_stack: 1740 return &bpf_get_stack_proto_tp; 1741 case BPF_FUNC_get_attach_cookie: 1742 return &bpf_get_attach_cookie_proto_trace; 1743 default: 1744 return bpf_tracing_func_proto(func_id, prog); 1745 } 1746 } 1747 1748 static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type, 1749 const struct bpf_prog *prog, 1750 struct bpf_insn_access_aux *info) 1751 { 1752 if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE) 1753 return false; 1754 if (type != BPF_READ) 1755 return false; 1756 if (off % size != 0) 1757 return false; 1758 1759 BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(__u64)); 1760 return true; 1761 } 1762 1763 const struct bpf_verifier_ops tracepoint_verifier_ops = { 1764 .get_func_proto = tp_prog_func_proto, 1765 .is_valid_access = tp_prog_is_valid_access, 1766 }; 1767 1768 const struct bpf_prog_ops tracepoint_prog_ops = { 1769 }; 1770 1771 BPF_CALL_3(bpf_perf_prog_read_value, struct bpf_perf_event_data_kern *, ctx, 1772 struct bpf_perf_event_value *, buf, u32, size) 1773 { 1774 int err = -EINVAL; 1775 1776 if (unlikely(size != sizeof(struct bpf_perf_event_value))) 1777 goto clear; 1778 err = perf_event_read_local(ctx->event, &buf->counter, &buf->enabled, 1779 &buf->running); 1780 if (unlikely(err)) 1781 goto clear; 1782 return 0; 1783 clear: 1784 memset(buf, 0, size); 1785 return err; 1786 } 1787 1788 static const struct bpf_func_proto bpf_perf_prog_read_value_proto = { 1789 .func = bpf_perf_prog_read_value, 1790 .gpl_only = true, 1791 .ret_type = RET_INTEGER, 1792 .arg1_type = ARG_PTR_TO_CTX, 1793 .arg2_type = ARG_PTR_TO_UNINIT_MEM, 1794 .arg3_type = ARG_CONST_SIZE, 1795 }; 1796 1797 BPF_CALL_4(bpf_read_branch_records, struct bpf_perf_event_data_kern *, ctx, 1798 void *, buf, u32, size, u64, flags) 1799 { 1800 static const u32 br_entry_size = sizeof(struct perf_branch_entry); 1801 struct perf_branch_stack *br_stack = ctx->data->br_stack; 1802 u32 to_copy; 1803 1804 if (unlikely(flags & ~BPF_F_GET_BRANCH_RECORDS_SIZE)) 1805 return -EINVAL; 1806 1807 if (unlikely(!(ctx->data->sample_flags & PERF_SAMPLE_BRANCH_STACK))) 1808 return -ENOENT; 1809 1810 if (unlikely(!br_stack)) 1811 return -ENOENT; 1812 1813 if (flags & BPF_F_GET_BRANCH_RECORDS_SIZE) 1814 return br_stack->nr * br_entry_size; 1815 1816 if (!buf || (size % br_entry_size != 0)) 1817 return -EINVAL; 1818 1819 to_copy = min_t(u32, br_stack->nr * br_entry_size, size); 1820 memcpy(buf, br_stack->entries, to_copy); 1821 1822 return to_copy; 1823 } 1824 1825 static const struct bpf_func_proto bpf_read_branch_records_proto = { 1826 .func = bpf_read_branch_records, 1827 .gpl_only = true, 1828 .ret_type = RET_INTEGER, 1829 .arg1_type = ARG_PTR_TO_CTX, 1830 .arg2_type = ARG_PTR_TO_MEM_OR_NULL, 1831 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1832 .arg4_type = ARG_ANYTHING, 1833 }; 1834 1835 static const struct bpf_func_proto * 1836 pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1837 { 1838 switch (func_id) { 1839 case BPF_FUNC_perf_event_output: 1840 return &bpf_perf_event_output_proto_tp; 1841 case BPF_FUNC_get_stackid: 1842 return &bpf_get_stackid_proto_pe; 1843 case BPF_FUNC_get_stack: 1844 return &bpf_get_stack_proto_pe; 1845 case BPF_FUNC_perf_prog_read_value: 1846 return &bpf_perf_prog_read_value_proto; 1847 case BPF_FUNC_read_branch_records: 1848 return &bpf_read_branch_records_proto; 1849 case BPF_FUNC_get_attach_cookie: 1850 return &bpf_get_attach_cookie_proto_pe; 1851 default: 1852 return bpf_tracing_func_proto(func_id, prog); 1853 } 1854 } 1855 1856 /* 1857 * bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp 1858 * to avoid potential recursive reuse issue when/if tracepoints are added 1859 * inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack. 1860 * 1861 * Since raw tracepoints run despite bpf_prog_active, support concurrent usage 1862 * in normal, irq, and nmi context. 1863 */ 1864 struct bpf_raw_tp_regs { 1865 struct pt_regs regs[3]; 1866 }; 1867 static DEFINE_PER_CPU(struct bpf_raw_tp_regs, bpf_raw_tp_regs); 1868 static DEFINE_PER_CPU(int, bpf_raw_tp_nest_level); 1869 static struct pt_regs *get_bpf_raw_tp_regs(void) 1870 { 1871 struct bpf_raw_tp_regs *tp_regs = this_cpu_ptr(&bpf_raw_tp_regs); 1872 int nest_level = this_cpu_inc_return(bpf_raw_tp_nest_level); 1873 1874 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(tp_regs->regs))) { 1875 this_cpu_dec(bpf_raw_tp_nest_level); 1876 return ERR_PTR(-EBUSY); 1877 } 1878 1879 return &tp_regs->regs[nest_level - 1]; 1880 } 1881 1882 static void put_bpf_raw_tp_regs(void) 1883 { 1884 this_cpu_dec(bpf_raw_tp_nest_level); 1885 } 1886 1887 BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args, 1888 struct bpf_map *, map, u64, flags, void *, data, u64, size) 1889 { 1890 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1891 int ret; 1892 1893 if (IS_ERR(regs)) 1894 return PTR_ERR(regs); 1895 1896 perf_fetch_caller_regs(regs); 1897 ret = ____bpf_perf_event_output(regs, map, flags, data, size); 1898 1899 put_bpf_raw_tp_regs(); 1900 return ret; 1901 } 1902 1903 static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = { 1904 .func = bpf_perf_event_output_raw_tp, 1905 .gpl_only = true, 1906 .ret_type = RET_INTEGER, 1907 .arg1_type = ARG_PTR_TO_CTX, 1908 .arg2_type = ARG_CONST_MAP_PTR, 1909 .arg3_type = ARG_ANYTHING, 1910 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1911 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 1912 }; 1913 1914 extern const struct bpf_func_proto bpf_skb_output_proto; 1915 extern const struct bpf_func_proto bpf_xdp_output_proto; 1916 extern const struct bpf_func_proto bpf_xdp_get_buff_len_trace_proto; 1917 1918 BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args, 1919 struct bpf_map *, map, u64, flags) 1920 { 1921 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1922 int ret; 1923 1924 if (IS_ERR(regs)) 1925 return PTR_ERR(regs); 1926 1927 perf_fetch_caller_regs(regs); 1928 /* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */ 1929 ret = bpf_get_stackid((unsigned long) regs, (unsigned long) map, 1930 flags, 0, 0); 1931 put_bpf_raw_tp_regs(); 1932 return ret; 1933 } 1934 1935 static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = { 1936 .func = bpf_get_stackid_raw_tp, 1937 .gpl_only = true, 1938 .ret_type = RET_INTEGER, 1939 .arg1_type = ARG_PTR_TO_CTX, 1940 .arg2_type = ARG_CONST_MAP_PTR, 1941 .arg3_type = ARG_ANYTHING, 1942 }; 1943 1944 BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args, 1945 void *, buf, u32, size, u64, flags) 1946 { 1947 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1948 int ret; 1949 1950 if (IS_ERR(regs)) 1951 return PTR_ERR(regs); 1952 1953 perf_fetch_caller_regs(regs); 1954 ret = bpf_get_stack((unsigned long) regs, (unsigned long) buf, 1955 (unsigned long) size, flags, 0); 1956 put_bpf_raw_tp_regs(); 1957 return ret; 1958 } 1959 1960 static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = { 1961 .func = bpf_get_stack_raw_tp, 1962 .gpl_only = true, 1963 .ret_type = RET_INTEGER, 1964 .arg1_type = ARG_PTR_TO_CTX, 1965 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1966 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1967 .arg4_type = ARG_ANYTHING, 1968 }; 1969 1970 static const struct bpf_func_proto * 1971 raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1972 { 1973 switch (func_id) { 1974 case BPF_FUNC_perf_event_output: 1975 return &bpf_perf_event_output_proto_raw_tp; 1976 case BPF_FUNC_get_stackid: 1977 return &bpf_get_stackid_proto_raw_tp; 1978 case BPF_FUNC_get_stack: 1979 return &bpf_get_stack_proto_raw_tp; 1980 case BPF_FUNC_get_attach_cookie: 1981 return &bpf_get_attach_cookie_proto_tracing; 1982 default: 1983 return bpf_tracing_func_proto(func_id, prog); 1984 } 1985 } 1986 1987 const struct bpf_func_proto * 1988 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1989 { 1990 const struct bpf_func_proto *fn; 1991 1992 switch (func_id) { 1993 #ifdef CONFIG_NET 1994 case BPF_FUNC_skb_output: 1995 return &bpf_skb_output_proto; 1996 case BPF_FUNC_xdp_output: 1997 return &bpf_xdp_output_proto; 1998 case BPF_FUNC_skc_to_tcp6_sock: 1999 return &bpf_skc_to_tcp6_sock_proto; 2000 case BPF_FUNC_skc_to_tcp_sock: 2001 return &bpf_skc_to_tcp_sock_proto; 2002 case BPF_FUNC_skc_to_tcp_timewait_sock: 2003 return &bpf_skc_to_tcp_timewait_sock_proto; 2004 case BPF_FUNC_skc_to_tcp_request_sock: 2005 return &bpf_skc_to_tcp_request_sock_proto; 2006 case BPF_FUNC_skc_to_udp6_sock: 2007 return &bpf_skc_to_udp6_sock_proto; 2008 case BPF_FUNC_skc_to_unix_sock: 2009 return &bpf_skc_to_unix_sock_proto; 2010 case BPF_FUNC_skc_to_mptcp_sock: 2011 return &bpf_skc_to_mptcp_sock_proto; 2012 case BPF_FUNC_sk_storage_get: 2013 return &bpf_sk_storage_get_tracing_proto; 2014 case BPF_FUNC_sk_storage_delete: 2015 return &bpf_sk_storage_delete_tracing_proto; 2016 case BPF_FUNC_sock_from_file: 2017 return &bpf_sock_from_file_proto; 2018 case BPF_FUNC_get_socket_cookie: 2019 return &bpf_get_socket_ptr_cookie_proto; 2020 case BPF_FUNC_xdp_get_buff_len: 2021 return &bpf_xdp_get_buff_len_trace_proto; 2022 #endif 2023 case BPF_FUNC_seq_printf: 2024 return prog->expected_attach_type == BPF_TRACE_ITER ? 2025 &bpf_seq_printf_proto : 2026 NULL; 2027 case BPF_FUNC_seq_write: 2028 return prog->expected_attach_type == BPF_TRACE_ITER ? 2029 &bpf_seq_write_proto : 2030 NULL; 2031 case BPF_FUNC_seq_printf_btf: 2032 return prog->expected_attach_type == BPF_TRACE_ITER ? 2033 &bpf_seq_printf_btf_proto : 2034 NULL; 2035 case BPF_FUNC_d_path: 2036 return &bpf_d_path_proto; 2037 case BPF_FUNC_get_func_arg: 2038 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_proto : NULL; 2039 case BPF_FUNC_get_func_ret: 2040 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_ret_proto : NULL; 2041 case BPF_FUNC_get_func_arg_cnt: 2042 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_cnt_proto : NULL; 2043 case BPF_FUNC_get_attach_cookie: 2044 if (prog->type == BPF_PROG_TYPE_TRACING && 2045 prog->expected_attach_type == BPF_TRACE_RAW_TP) 2046 return &bpf_get_attach_cookie_proto_tracing; 2047 return bpf_prog_has_trampoline(prog) ? &bpf_get_attach_cookie_proto_tracing : NULL; 2048 default: 2049 fn = raw_tp_prog_func_proto(func_id, prog); 2050 if (!fn && prog->expected_attach_type == BPF_TRACE_ITER) 2051 fn = bpf_iter_get_func_proto(func_id, prog); 2052 return fn; 2053 } 2054 } 2055 2056 static bool raw_tp_prog_is_valid_access(int off, int size, 2057 enum bpf_access_type type, 2058 const struct bpf_prog *prog, 2059 struct bpf_insn_access_aux *info) 2060 { 2061 return bpf_tracing_ctx_access(off, size, type); 2062 } 2063 2064 static bool tracing_prog_is_valid_access(int off, int size, 2065 enum bpf_access_type type, 2066 const struct bpf_prog *prog, 2067 struct bpf_insn_access_aux *info) 2068 { 2069 return bpf_tracing_btf_ctx_access(off, size, type, prog, info); 2070 } 2071 2072 int __weak bpf_prog_test_run_tracing(struct bpf_prog *prog, 2073 const union bpf_attr *kattr, 2074 union bpf_attr __user *uattr) 2075 { 2076 return -ENOTSUPP; 2077 } 2078 2079 const struct bpf_verifier_ops raw_tracepoint_verifier_ops = { 2080 .get_func_proto = raw_tp_prog_func_proto, 2081 .is_valid_access = raw_tp_prog_is_valid_access, 2082 }; 2083 2084 const struct bpf_prog_ops raw_tracepoint_prog_ops = { 2085 #ifdef CONFIG_NET 2086 .test_run = bpf_prog_test_run_raw_tp, 2087 #endif 2088 }; 2089 2090 const struct bpf_verifier_ops tracing_verifier_ops = { 2091 .get_func_proto = tracing_prog_func_proto, 2092 .is_valid_access = tracing_prog_is_valid_access, 2093 }; 2094 2095 const struct bpf_prog_ops tracing_prog_ops = { 2096 .test_run = bpf_prog_test_run_tracing, 2097 }; 2098 2099 static bool raw_tp_writable_prog_is_valid_access(int off, int size, 2100 enum bpf_access_type type, 2101 const struct bpf_prog *prog, 2102 struct bpf_insn_access_aux *info) 2103 { 2104 if (off == 0) { 2105 if (size != sizeof(u64) || type != BPF_READ) 2106 return false; 2107 info->reg_type = PTR_TO_TP_BUFFER; 2108 } 2109 return raw_tp_prog_is_valid_access(off, size, type, prog, info); 2110 } 2111 2112 const struct bpf_verifier_ops raw_tracepoint_writable_verifier_ops = { 2113 .get_func_proto = raw_tp_prog_func_proto, 2114 .is_valid_access = raw_tp_writable_prog_is_valid_access, 2115 }; 2116 2117 const struct bpf_prog_ops raw_tracepoint_writable_prog_ops = { 2118 }; 2119 2120 static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type, 2121 const struct bpf_prog *prog, 2122 struct bpf_insn_access_aux *info) 2123 { 2124 const int size_u64 = sizeof(u64); 2125 2126 if (off < 0 || off >= sizeof(struct bpf_perf_event_data)) 2127 return false; 2128 if (type != BPF_READ) 2129 return false; 2130 if (off % size != 0) { 2131 if (sizeof(unsigned long) != 4) 2132 return false; 2133 if (size != 8) 2134 return false; 2135 if (off % size != 4) 2136 return false; 2137 } 2138 2139 switch (off) { 2140 case bpf_ctx_range(struct bpf_perf_event_data, sample_period): 2141 bpf_ctx_record_field_size(info, size_u64); 2142 if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) 2143 return false; 2144 break; 2145 case bpf_ctx_range(struct bpf_perf_event_data, addr): 2146 bpf_ctx_record_field_size(info, size_u64); 2147 if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) 2148 return false; 2149 break; 2150 default: 2151 if (size != sizeof(long)) 2152 return false; 2153 } 2154 2155 return true; 2156 } 2157 2158 static u32 pe_prog_convert_ctx_access(enum bpf_access_type type, 2159 const struct bpf_insn *si, 2160 struct bpf_insn *insn_buf, 2161 struct bpf_prog *prog, u32 *target_size) 2162 { 2163 struct bpf_insn *insn = insn_buf; 2164 2165 switch (si->off) { 2166 case offsetof(struct bpf_perf_event_data, sample_period): 2167 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 2168 data), si->dst_reg, si->src_reg, 2169 offsetof(struct bpf_perf_event_data_kern, data)); 2170 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, 2171 bpf_target_off(struct perf_sample_data, period, 8, 2172 target_size)); 2173 break; 2174 case offsetof(struct bpf_perf_event_data, addr): 2175 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 2176 data), si->dst_reg, si->src_reg, 2177 offsetof(struct bpf_perf_event_data_kern, data)); 2178 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, 2179 bpf_target_off(struct perf_sample_data, addr, 8, 2180 target_size)); 2181 break; 2182 default: 2183 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 2184 regs), si->dst_reg, si->src_reg, 2185 offsetof(struct bpf_perf_event_data_kern, regs)); 2186 *insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg, 2187 si->off); 2188 break; 2189 } 2190 2191 return insn - insn_buf; 2192 } 2193 2194 const struct bpf_verifier_ops perf_event_verifier_ops = { 2195 .get_func_proto = pe_prog_func_proto, 2196 .is_valid_access = pe_prog_is_valid_access, 2197 .convert_ctx_access = pe_prog_convert_ctx_access, 2198 }; 2199 2200 const struct bpf_prog_ops perf_event_prog_ops = { 2201 }; 2202 2203 static DEFINE_MUTEX(bpf_event_mutex); 2204 2205 #define BPF_TRACE_MAX_PROGS 64 2206 2207 int perf_event_attach_bpf_prog(struct perf_event *event, 2208 struct bpf_prog *prog, 2209 u64 bpf_cookie) 2210 { 2211 struct bpf_prog_array *old_array; 2212 struct bpf_prog_array *new_array; 2213 int ret = -EEXIST; 2214 2215 /* 2216 * Kprobe override only works if they are on the function entry, 2217 * and only if they are on the opt-in list. 2218 */ 2219 if (prog->kprobe_override && 2220 (!trace_kprobe_on_func_entry(event->tp_event) || 2221 !trace_kprobe_error_injectable(event->tp_event))) 2222 return -EINVAL; 2223 2224 mutex_lock(&bpf_event_mutex); 2225 2226 if (event->prog) 2227 goto unlock; 2228 2229 old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); 2230 if (old_array && 2231 bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) { 2232 ret = -E2BIG; 2233 goto unlock; 2234 } 2235 2236 ret = bpf_prog_array_copy(old_array, NULL, prog, bpf_cookie, &new_array); 2237 if (ret < 0) 2238 goto unlock; 2239 2240 /* set the new array to event->tp_event and set event->prog */ 2241 event->prog = prog; 2242 event->bpf_cookie = bpf_cookie; 2243 rcu_assign_pointer(event->tp_event->prog_array, new_array); 2244 bpf_prog_array_free_sleepable(old_array); 2245 2246 unlock: 2247 mutex_unlock(&bpf_event_mutex); 2248 return ret; 2249 } 2250 2251 void perf_event_detach_bpf_prog(struct perf_event *event) 2252 { 2253 struct bpf_prog_array *old_array; 2254 struct bpf_prog_array *new_array; 2255 struct bpf_prog *prog = NULL; 2256 int ret; 2257 2258 mutex_lock(&bpf_event_mutex); 2259 2260 if (!event->prog) 2261 goto unlock; 2262 2263 old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); 2264 if (!old_array) 2265 goto put; 2266 2267 ret = bpf_prog_array_copy(old_array, event->prog, NULL, 0, &new_array); 2268 if (ret < 0) { 2269 bpf_prog_array_delete_safe(old_array, event->prog); 2270 } else { 2271 rcu_assign_pointer(event->tp_event->prog_array, new_array); 2272 bpf_prog_array_free_sleepable(old_array); 2273 } 2274 2275 put: 2276 prog = event->prog; 2277 event->prog = NULL; 2278 2279 unlock: 2280 mutex_unlock(&bpf_event_mutex); 2281 2282 if (prog) { 2283 /* 2284 * It could be that the bpf_prog is not sleepable (and will be freed 2285 * via normal RCU), but is called from a point that supports sleepable 2286 * programs and uses tasks-trace-RCU. 2287 */ 2288 synchronize_rcu_tasks_trace(); 2289 2290 bpf_prog_put(prog); 2291 } 2292 } 2293 2294 int perf_event_query_prog_array(struct perf_event *event, void __user *info) 2295 { 2296 struct perf_event_query_bpf __user *uquery = info; 2297 struct perf_event_query_bpf query = {}; 2298 struct bpf_prog_array *progs; 2299 u32 *ids, prog_cnt, ids_len; 2300 int ret; 2301 2302 if (!perfmon_capable()) 2303 return -EPERM; 2304 if (event->attr.type != PERF_TYPE_TRACEPOINT) 2305 return -EINVAL; 2306 if (copy_from_user(&query, uquery, sizeof(query))) 2307 return -EFAULT; 2308 2309 ids_len = query.ids_len; 2310 if (ids_len > BPF_TRACE_MAX_PROGS) 2311 return -E2BIG; 2312 ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN); 2313 if (!ids) 2314 return -ENOMEM; 2315 /* 2316 * The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which 2317 * is required when user only wants to check for uquery->prog_cnt. 2318 * There is no need to check for it since the case is handled 2319 * gracefully in bpf_prog_array_copy_info. 2320 */ 2321 2322 mutex_lock(&bpf_event_mutex); 2323 progs = bpf_event_rcu_dereference(event->tp_event->prog_array); 2324 ret = bpf_prog_array_copy_info(progs, ids, ids_len, &prog_cnt); 2325 mutex_unlock(&bpf_event_mutex); 2326 2327 if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) || 2328 copy_to_user(uquery->ids, ids, ids_len * sizeof(u32))) 2329 ret = -EFAULT; 2330 2331 kfree(ids); 2332 return ret; 2333 } 2334 2335 extern struct bpf_raw_event_map __start__bpf_raw_tp[]; 2336 extern struct bpf_raw_event_map __stop__bpf_raw_tp[]; 2337 2338 struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name) 2339 { 2340 struct bpf_raw_event_map *btp = __start__bpf_raw_tp; 2341 2342 for (; btp < __stop__bpf_raw_tp; btp++) { 2343 if (!strcmp(btp->tp->name, name)) 2344 return btp; 2345 } 2346 2347 return bpf_get_raw_tracepoint_module(name); 2348 } 2349 2350 void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp) 2351 { 2352 struct module *mod; 2353 2354 preempt_disable(); 2355 mod = __module_address((unsigned long)btp); 2356 module_put(mod); 2357 preempt_enable(); 2358 } 2359 2360 static __always_inline 2361 void __bpf_trace_run(struct bpf_raw_tp_link *link, u64 *args) 2362 { 2363 struct bpf_prog *prog = link->link.prog; 2364 struct bpf_run_ctx *old_run_ctx; 2365 struct bpf_trace_run_ctx run_ctx; 2366 2367 cant_sleep(); 2368 if (unlikely(this_cpu_inc_return(*(prog->active)) != 1)) { 2369 bpf_prog_inc_misses_counter(prog); 2370 goto out; 2371 } 2372 2373 run_ctx.bpf_cookie = link->cookie; 2374 old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx); 2375 2376 rcu_read_lock(); 2377 (void) bpf_prog_run(prog, args); 2378 rcu_read_unlock(); 2379 2380 bpf_reset_run_ctx(old_run_ctx); 2381 out: 2382 this_cpu_dec(*(prog->active)); 2383 } 2384 2385 #define UNPACK(...) __VA_ARGS__ 2386 #define REPEAT_1(FN, DL, X, ...) FN(X) 2387 #define REPEAT_2(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__) 2388 #define REPEAT_3(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_2(FN, DL, __VA_ARGS__) 2389 #define REPEAT_4(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_3(FN, DL, __VA_ARGS__) 2390 #define REPEAT_5(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_4(FN, DL, __VA_ARGS__) 2391 #define REPEAT_6(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_5(FN, DL, __VA_ARGS__) 2392 #define REPEAT_7(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_6(FN, DL, __VA_ARGS__) 2393 #define REPEAT_8(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_7(FN, DL, __VA_ARGS__) 2394 #define REPEAT_9(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_8(FN, DL, __VA_ARGS__) 2395 #define REPEAT_10(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_9(FN, DL, __VA_ARGS__) 2396 #define REPEAT_11(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_10(FN, DL, __VA_ARGS__) 2397 #define REPEAT_12(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_11(FN, DL, __VA_ARGS__) 2398 #define REPEAT(X, FN, DL, ...) REPEAT_##X(FN, DL, __VA_ARGS__) 2399 2400 #define SARG(X) u64 arg##X 2401 #define COPY(X) args[X] = arg##X 2402 2403 #define __DL_COM (,) 2404 #define __DL_SEM (;) 2405 2406 #define __SEQ_0_11 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 2407 2408 #define BPF_TRACE_DEFN_x(x) \ 2409 void bpf_trace_run##x(struct bpf_raw_tp_link *link, \ 2410 REPEAT(x, SARG, __DL_COM, __SEQ_0_11)) \ 2411 { \ 2412 u64 args[x]; \ 2413 REPEAT(x, COPY, __DL_SEM, __SEQ_0_11); \ 2414 __bpf_trace_run(link, args); \ 2415 } \ 2416 EXPORT_SYMBOL_GPL(bpf_trace_run##x) 2417 BPF_TRACE_DEFN_x(1); 2418 BPF_TRACE_DEFN_x(2); 2419 BPF_TRACE_DEFN_x(3); 2420 BPF_TRACE_DEFN_x(4); 2421 BPF_TRACE_DEFN_x(5); 2422 BPF_TRACE_DEFN_x(6); 2423 BPF_TRACE_DEFN_x(7); 2424 BPF_TRACE_DEFN_x(8); 2425 BPF_TRACE_DEFN_x(9); 2426 BPF_TRACE_DEFN_x(10); 2427 BPF_TRACE_DEFN_x(11); 2428 BPF_TRACE_DEFN_x(12); 2429 2430 int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_raw_tp_link *link) 2431 { 2432 struct tracepoint *tp = btp->tp; 2433 struct bpf_prog *prog = link->link.prog; 2434 2435 /* 2436 * check that program doesn't access arguments beyond what's 2437 * available in this tracepoint 2438 */ 2439 if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64)) 2440 return -EINVAL; 2441 2442 if (prog->aux->max_tp_access > btp->writable_size) 2443 return -EINVAL; 2444 2445 return tracepoint_probe_register_may_exist(tp, (void *)btp->bpf_func, link); 2446 } 2447 2448 int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_raw_tp_link *link) 2449 { 2450 return tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, link); 2451 } 2452 2453 int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id, 2454 u32 *fd_type, const char **buf, 2455 u64 *probe_offset, u64 *probe_addr, 2456 unsigned long *missed) 2457 { 2458 bool is_tracepoint, is_syscall_tp; 2459 struct bpf_prog *prog; 2460 int flags, err = 0; 2461 2462 prog = event->prog; 2463 if (!prog) 2464 return -ENOENT; 2465 2466 /* not supporting BPF_PROG_TYPE_PERF_EVENT yet */ 2467 if (prog->type == BPF_PROG_TYPE_PERF_EVENT) 2468 return -EOPNOTSUPP; 2469 2470 *prog_id = prog->aux->id; 2471 flags = event->tp_event->flags; 2472 is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT; 2473 is_syscall_tp = is_syscall_trace_event(event->tp_event); 2474 2475 if (is_tracepoint || is_syscall_tp) { 2476 *buf = is_tracepoint ? event->tp_event->tp->name 2477 : event->tp_event->name; 2478 /* We allow NULL pointer for tracepoint */ 2479 if (fd_type) 2480 *fd_type = BPF_FD_TYPE_TRACEPOINT; 2481 if (probe_offset) 2482 *probe_offset = 0x0; 2483 if (probe_addr) 2484 *probe_addr = 0x0; 2485 } else { 2486 /* kprobe/uprobe */ 2487 err = -EOPNOTSUPP; 2488 #ifdef CONFIG_KPROBE_EVENTS 2489 if (flags & TRACE_EVENT_FL_KPROBE) 2490 err = bpf_get_kprobe_info(event, fd_type, buf, 2491 probe_offset, probe_addr, missed, 2492 event->attr.type == PERF_TYPE_TRACEPOINT); 2493 #endif 2494 #ifdef CONFIG_UPROBE_EVENTS 2495 if (flags & TRACE_EVENT_FL_UPROBE) 2496 err = bpf_get_uprobe_info(event, fd_type, buf, 2497 probe_offset, probe_addr, 2498 event->attr.type == PERF_TYPE_TRACEPOINT); 2499 #endif 2500 } 2501 2502 return err; 2503 } 2504 2505 static int __init send_signal_irq_work_init(void) 2506 { 2507 int cpu; 2508 struct send_signal_irq_work *work; 2509 2510 for_each_possible_cpu(cpu) { 2511 work = per_cpu_ptr(&send_signal_work, cpu); 2512 init_irq_work(&work->irq_work, do_bpf_send_signal); 2513 } 2514 return 0; 2515 } 2516 2517 subsys_initcall(send_signal_irq_work_init); 2518 2519 #ifdef CONFIG_MODULES 2520 static int bpf_event_notify(struct notifier_block *nb, unsigned long op, 2521 void *module) 2522 { 2523 struct bpf_trace_module *btm, *tmp; 2524 struct module *mod = module; 2525 int ret = 0; 2526 2527 if (mod->num_bpf_raw_events == 0 || 2528 (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING)) 2529 goto out; 2530 2531 mutex_lock(&bpf_module_mutex); 2532 2533 switch (op) { 2534 case MODULE_STATE_COMING: 2535 btm = kzalloc(sizeof(*btm), GFP_KERNEL); 2536 if (btm) { 2537 btm->module = module; 2538 list_add(&btm->list, &bpf_trace_modules); 2539 } else { 2540 ret = -ENOMEM; 2541 } 2542 break; 2543 case MODULE_STATE_GOING: 2544 list_for_each_entry_safe(btm, tmp, &bpf_trace_modules, list) { 2545 if (btm->module == module) { 2546 list_del(&btm->list); 2547 kfree(btm); 2548 break; 2549 } 2550 } 2551 break; 2552 } 2553 2554 mutex_unlock(&bpf_module_mutex); 2555 2556 out: 2557 return notifier_from_errno(ret); 2558 } 2559 2560 static struct notifier_block bpf_module_nb = { 2561 .notifier_call = bpf_event_notify, 2562 }; 2563 2564 static int __init bpf_event_init(void) 2565 { 2566 register_module_notifier(&bpf_module_nb); 2567 return 0; 2568 } 2569 2570 fs_initcall(bpf_event_init); 2571 #endif /* CONFIG_MODULES */ 2572 2573 struct bpf_session_run_ctx { 2574 struct bpf_run_ctx run_ctx; 2575 bool is_return; 2576 void *data; 2577 }; 2578 2579 #ifdef CONFIG_FPROBE 2580 struct bpf_kprobe_multi_link { 2581 struct bpf_link link; 2582 struct fprobe fp; 2583 unsigned long *addrs; 2584 u64 *cookies; 2585 u32 cnt; 2586 u32 mods_cnt; 2587 struct module **mods; 2588 u32 flags; 2589 }; 2590 2591 struct bpf_kprobe_multi_run_ctx { 2592 struct bpf_session_run_ctx session_ctx; 2593 struct bpf_kprobe_multi_link *link; 2594 unsigned long entry_ip; 2595 }; 2596 2597 struct user_syms { 2598 const char **syms; 2599 char *buf; 2600 }; 2601 2602 #ifndef CONFIG_HAVE_FTRACE_REGS_HAVING_PT_REGS 2603 static DEFINE_PER_CPU(struct pt_regs, bpf_kprobe_multi_pt_regs); 2604 #define bpf_kprobe_multi_pt_regs_ptr() this_cpu_ptr(&bpf_kprobe_multi_pt_regs) 2605 #else 2606 #define bpf_kprobe_multi_pt_regs_ptr() (NULL) 2607 #endif 2608 2609 static unsigned long ftrace_get_entry_ip(unsigned long fentry_ip) 2610 { 2611 unsigned long ip = ftrace_get_symaddr(fentry_ip); 2612 2613 return ip ? : fentry_ip; 2614 } 2615 2616 static int copy_user_syms(struct user_syms *us, unsigned long __user *usyms, u32 cnt) 2617 { 2618 unsigned long __user usymbol; 2619 const char **syms = NULL; 2620 char *buf = NULL, *p; 2621 int err = -ENOMEM; 2622 unsigned int i; 2623 2624 syms = kvmalloc_array(cnt, sizeof(*syms), GFP_KERNEL); 2625 if (!syms) 2626 goto error; 2627 2628 buf = kvmalloc_array(cnt, KSYM_NAME_LEN, GFP_KERNEL); 2629 if (!buf) 2630 goto error; 2631 2632 for (p = buf, i = 0; i < cnt; i++) { 2633 if (__get_user(usymbol, usyms + i)) { 2634 err = -EFAULT; 2635 goto error; 2636 } 2637 err = strncpy_from_user(p, (const char __user *) usymbol, KSYM_NAME_LEN); 2638 if (err == KSYM_NAME_LEN) 2639 err = -E2BIG; 2640 if (err < 0) 2641 goto error; 2642 syms[i] = p; 2643 p += err + 1; 2644 } 2645 2646 us->syms = syms; 2647 us->buf = buf; 2648 return 0; 2649 2650 error: 2651 if (err) { 2652 kvfree(syms); 2653 kvfree(buf); 2654 } 2655 return err; 2656 } 2657 2658 static void kprobe_multi_put_modules(struct module **mods, u32 cnt) 2659 { 2660 u32 i; 2661 2662 for (i = 0; i < cnt; i++) 2663 module_put(mods[i]); 2664 } 2665 2666 static void free_user_syms(struct user_syms *us) 2667 { 2668 kvfree(us->syms); 2669 kvfree(us->buf); 2670 } 2671 2672 static void bpf_kprobe_multi_link_release(struct bpf_link *link) 2673 { 2674 struct bpf_kprobe_multi_link *kmulti_link; 2675 2676 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); 2677 unregister_fprobe(&kmulti_link->fp); 2678 kprobe_multi_put_modules(kmulti_link->mods, kmulti_link->mods_cnt); 2679 } 2680 2681 static void bpf_kprobe_multi_link_dealloc(struct bpf_link *link) 2682 { 2683 struct bpf_kprobe_multi_link *kmulti_link; 2684 2685 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); 2686 kvfree(kmulti_link->addrs); 2687 kvfree(kmulti_link->cookies); 2688 kfree(kmulti_link->mods); 2689 kfree(kmulti_link); 2690 } 2691 2692 static int bpf_kprobe_multi_link_fill_link_info(const struct bpf_link *link, 2693 struct bpf_link_info *info) 2694 { 2695 u64 __user *ucookies = u64_to_user_ptr(info->kprobe_multi.cookies); 2696 u64 __user *uaddrs = u64_to_user_ptr(info->kprobe_multi.addrs); 2697 struct bpf_kprobe_multi_link *kmulti_link; 2698 u32 ucount = info->kprobe_multi.count; 2699 int err = 0, i; 2700 2701 if (!uaddrs ^ !ucount) 2702 return -EINVAL; 2703 if (ucookies && !ucount) 2704 return -EINVAL; 2705 2706 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); 2707 info->kprobe_multi.count = kmulti_link->cnt; 2708 info->kprobe_multi.flags = kmulti_link->flags; 2709 info->kprobe_multi.missed = kmulti_link->fp.nmissed; 2710 2711 if (!uaddrs) 2712 return 0; 2713 if (ucount < kmulti_link->cnt) 2714 err = -ENOSPC; 2715 else 2716 ucount = kmulti_link->cnt; 2717 2718 if (ucookies) { 2719 if (kmulti_link->cookies) { 2720 if (copy_to_user(ucookies, kmulti_link->cookies, ucount * sizeof(u64))) 2721 return -EFAULT; 2722 } else { 2723 for (i = 0; i < ucount; i++) { 2724 if (put_user(0, ucookies + i)) 2725 return -EFAULT; 2726 } 2727 } 2728 } 2729 2730 if (kallsyms_show_value(current_cred())) { 2731 if (copy_to_user(uaddrs, kmulti_link->addrs, ucount * sizeof(u64))) 2732 return -EFAULT; 2733 } else { 2734 for (i = 0; i < ucount; i++) { 2735 if (put_user(0, uaddrs + i)) 2736 return -EFAULT; 2737 } 2738 } 2739 return err; 2740 } 2741 2742 static const struct bpf_link_ops bpf_kprobe_multi_link_lops = { 2743 .release = bpf_kprobe_multi_link_release, 2744 .dealloc_deferred = bpf_kprobe_multi_link_dealloc, 2745 .fill_link_info = bpf_kprobe_multi_link_fill_link_info, 2746 }; 2747 2748 static void bpf_kprobe_multi_cookie_swap(void *a, void *b, int size, const void *priv) 2749 { 2750 const struct bpf_kprobe_multi_link *link = priv; 2751 unsigned long *addr_a = a, *addr_b = b; 2752 u64 *cookie_a, *cookie_b; 2753 2754 cookie_a = link->cookies + (addr_a - link->addrs); 2755 cookie_b = link->cookies + (addr_b - link->addrs); 2756 2757 /* swap addr_a/addr_b and cookie_a/cookie_b values */ 2758 swap(*addr_a, *addr_b); 2759 swap(*cookie_a, *cookie_b); 2760 } 2761 2762 static int bpf_kprobe_multi_addrs_cmp(const void *a, const void *b) 2763 { 2764 const unsigned long *addr_a = a, *addr_b = b; 2765 2766 if (*addr_a == *addr_b) 2767 return 0; 2768 return *addr_a < *addr_b ? -1 : 1; 2769 } 2770 2771 static int bpf_kprobe_multi_cookie_cmp(const void *a, const void *b, const void *priv) 2772 { 2773 return bpf_kprobe_multi_addrs_cmp(a, b); 2774 } 2775 2776 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx) 2777 { 2778 struct bpf_kprobe_multi_run_ctx *run_ctx; 2779 struct bpf_kprobe_multi_link *link; 2780 u64 *cookie, entry_ip; 2781 unsigned long *addr; 2782 2783 if (WARN_ON_ONCE(!ctx)) 2784 return 0; 2785 run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, 2786 session_ctx.run_ctx); 2787 link = run_ctx->link; 2788 if (!link->cookies) 2789 return 0; 2790 entry_ip = run_ctx->entry_ip; 2791 addr = bsearch(&entry_ip, link->addrs, link->cnt, sizeof(entry_ip), 2792 bpf_kprobe_multi_addrs_cmp); 2793 if (!addr) 2794 return 0; 2795 cookie = link->cookies + (addr - link->addrs); 2796 return *cookie; 2797 } 2798 2799 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 2800 { 2801 struct bpf_kprobe_multi_run_ctx *run_ctx; 2802 2803 run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, 2804 session_ctx.run_ctx); 2805 return run_ctx->entry_ip; 2806 } 2807 2808 static int 2809 kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link, 2810 unsigned long entry_ip, struct ftrace_regs *fregs, 2811 bool is_return, void *data) 2812 { 2813 struct bpf_kprobe_multi_run_ctx run_ctx = { 2814 .session_ctx = { 2815 .is_return = is_return, 2816 .data = data, 2817 }, 2818 .link = link, 2819 .entry_ip = entry_ip, 2820 }; 2821 struct bpf_run_ctx *old_run_ctx; 2822 struct pt_regs *regs; 2823 int err; 2824 2825 if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) { 2826 bpf_prog_inc_misses_counter(link->link.prog); 2827 err = 1; 2828 goto out; 2829 } 2830 2831 migrate_disable(); 2832 rcu_read_lock(); 2833 regs = ftrace_partial_regs(fregs, bpf_kprobe_multi_pt_regs_ptr()); 2834 old_run_ctx = bpf_set_run_ctx(&run_ctx.session_ctx.run_ctx); 2835 err = bpf_prog_run(link->link.prog, regs); 2836 bpf_reset_run_ctx(old_run_ctx); 2837 rcu_read_unlock(); 2838 migrate_enable(); 2839 2840 out: 2841 __this_cpu_dec(bpf_prog_active); 2842 return err; 2843 } 2844 2845 static int 2846 kprobe_multi_link_handler(struct fprobe *fp, unsigned long fentry_ip, 2847 unsigned long ret_ip, struct ftrace_regs *fregs, 2848 void *data) 2849 { 2850 struct bpf_kprobe_multi_link *link; 2851 int err; 2852 2853 link = container_of(fp, struct bpf_kprobe_multi_link, fp); 2854 err = kprobe_multi_link_prog_run(link, ftrace_get_entry_ip(fentry_ip), 2855 fregs, false, data); 2856 return is_kprobe_session(link->link.prog) ? err : 0; 2857 } 2858 2859 static void 2860 kprobe_multi_link_exit_handler(struct fprobe *fp, unsigned long fentry_ip, 2861 unsigned long ret_ip, struct ftrace_regs *fregs, 2862 void *data) 2863 { 2864 struct bpf_kprobe_multi_link *link; 2865 2866 link = container_of(fp, struct bpf_kprobe_multi_link, fp); 2867 kprobe_multi_link_prog_run(link, ftrace_get_entry_ip(fentry_ip), 2868 fregs, true, data); 2869 } 2870 2871 static int symbols_cmp_r(const void *a, const void *b, const void *priv) 2872 { 2873 const char **str_a = (const char **) a; 2874 const char **str_b = (const char **) b; 2875 2876 return strcmp(*str_a, *str_b); 2877 } 2878 2879 struct multi_symbols_sort { 2880 const char **funcs; 2881 u64 *cookies; 2882 }; 2883 2884 static void symbols_swap_r(void *a, void *b, int size, const void *priv) 2885 { 2886 const struct multi_symbols_sort *data = priv; 2887 const char **name_a = a, **name_b = b; 2888 2889 swap(*name_a, *name_b); 2890 2891 /* If defined, swap also related cookies. */ 2892 if (data->cookies) { 2893 u64 *cookie_a, *cookie_b; 2894 2895 cookie_a = data->cookies + (name_a - data->funcs); 2896 cookie_b = data->cookies + (name_b - data->funcs); 2897 swap(*cookie_a, *cookie_b); 2898 } 2899 } 2900 2901 struct modules_array { 2902 struct module **mods; 2903 int mods_cnt; 2904 int mods_cap; 2905 }; 2906 2907 static int add_module(struct modules_array *arr, struct module *mod) 2908 { 2909 struct module **mods; 2910 2911 if (arr->mods_cnt == arr->mods_cap) { 2912 arr->mods_cap = max(16, arr->mods_cap * 3 / 2); 2913 mods = krealloc_array(arr->mods, arr->mods_cap, sizeof(*mods), GFP_KERNEL); 2914 if (!mods) 2915 return -ENOMEM; 2916 arr->mods = mods; 2917 } 2918 2919 arr->mods[arr->mods_cnt] = mod; 2920 arr->mods_cnt++; 2921 return 0; 2922 } 2923 2924 static bool has_module(struct modules_array *arr, struct module *mod) 2925 { 2926 int i; 2927 2928 for (i = arr->mods_cnt - 1; i >= 0; i--) { 2929 if (arr->mods[i] == mod) 2930 return true; 2931 } 2932 return false; 2933 } 2934 2935 static int get_modules_for_addrs(struct module ***mods, unsigned long *addrs, u32 addrs_cnt) 2936 { 2937 struct modules_array arr = {}; 2938 u32 i, err = 0; 2939 2940 for (i = 0; i < addrs_cnt; i++) { 2941 struct module *mod; 2942 2943 preempt_disable(); 2944 mod = __module_address(addrs[i]); 2945 /* Either no module or we it's already stored */ 2946 if (!mod || has_module(&arr, mod)) { 2947 preempt_enable(); 2948 continue; 2949 } 2950 if (!try_module_get(mod)) 2951 err = -EINVAL; 2952 preempt_enable(); 2953 if (err) 2954 break; 2955 err = add_module(&arr, mod); 2956 if (err) { 2957 module_put(mod); 2958 break; 2959 } 2960 } 2961 2962 /* We return either err < 0 in case of error, ... */ 2963 if (err) { 2964 kprobe_multi_put_modules(arr.mods, arr.mods_cnt); 2965 kfree(arr.mods); 2966 return err; 2967 } 2968 2969 /* or number of modules found if everything is ok. */ 2970 *mods = arr.mods; 2971 return arr.mods_cnt; 2972 } 2973 2974 static int addrs_check_error_injection_list(unsigned long *addrs, u32 cnt) 2975 { 2976 u32 i; 2977 2978 for (i = 0; i < cnt; i++) { 2979 if (!within_error_injection_list(addrs[i])) 2980 return -EINVAL; 2981 } 2982 return 0; 2983 } 2984 2985 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 2986 { 2987 struct bpf_kprobe_multi_link *link = NULL; 2988 struct bpf_link_primer link_primer; 2989 void __user *ucookies; 2990 unsigned long *addrs; 2991 u32 flags, cnt, size; 2992 void __user *uaddrs; 2993 u64 *cookies = NULL; 2994 void __user *usyms; 2995 int err; 2996 2997 /* no support for 32bit archs yet */ 2998 if (sizeof(u64) != sizeof(void *)) 2999 return -EOPNOTSUPP; 3000 3001 if (!is_kprobe_multi(prog)) 3002 return -EINVAL; 3003 3004 flags = attr->link_create.kprobe_multi.flags; 3005 if (flags & ~BPF_F_KPROBE_MULTI_RETURN) 3006 return -EINVAL; 3007 3008 uaddrs = u64_to_user_ptr(attr->link_create.kprobe_multi.addrs); 3009 usyms = u64_to_user_ptr(attr->link_create.kprobe_multi.syms); 3010 if (!!uaddrs == !!usyms) 3011 return -EINVAL; 3012 3013 cnt = attr->link_create.kprobe_multi.cnt; 3014 if (!cnt) 3015 return -EINVAL; 3016 if (cnt > MAX_KPROBE_MULTI_CNT) 3017 return -E2BIG; 3018 3019 size = cnt * sizeof(*addrs); 3020 addrs = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL); 3021 if (!addrs) 3022 return -ENOMEM; 3023 3024 ucookies = u64_to_user_ptr(attr->link_create.kprobe_multi.cookies); 3025 if (ucookies) { 3026 cookies = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL); 3027 if (!cookies) { 3028 err = -ENOMEM; 3029 goto error; 3030 } 3031 if (copy_from_user(cookies, ucookies, size)) { 3032 err = -EFAULT; 3033 goto error; 3034 } 3035 } 3036 3037 if (uaddrs) { 3038 if (copy_from_user(addrs, uaddrs, size)) { 3039 err = -EFAULT; 3040 goto error; 3041 } 3042 } else { 3043 struct multi_symbols_sort data = { 3044 .cookies = cookies, 3045 }; 3046 struct user_syms us; 3047 3048 err = copy_user_syms(&us, usyms, cnt); 3049 if (err) 3050 goto error; 3051 3052 if (cookies) 3053 data.funcs = us.syms; 3054 3055 sort_r(us.syms, cnt, sizeof(*us.syms), symbols_cmp_r, 3056 symbols_swap_r, &data); 3057 3058 err = ftrace_lookup_symbols(us.syms, cnt, addrs); 3059 free_user_syms(&us); 3060 if (err) 3061 goto error; 3062 } 3063 3064 if (prog->kprobe_override && addrs_check_error_injection_list(addrs, cnt)) { 3065 err = -EINVAL; 3066 goto error; 3067 } 3068 3069 link = kzalloc(sizeof(*link), GFP_KERNEL); 3070 if (!link) { 3071 err = -ENOMEM; 3072 goto error; 3073 } 3074 3075 bpf_link_init(&link->link, BPF_LINK_TYPE_KPROBE_MULTI, 3076 &bpf_kprobe_multi_link_lops, prog); 3077 3078 err = bpf_link_prime(&link->link, &link_primer); 3079 if (err) 3080 goto error; 3081 3082 if (!(flags & BPF_F_KPROBE_MULTI_RETURN)) 3083 link->fp.entry_handler = kprobe_multi_link_handler; 3084 if ((flags & BPF_F_KPROBE_MULTI_RETURN) || is_kprobe_session(prog)) 3085 link->fp.exit_handler = kprobe_multi_link_exit_handler; 3086 if (is_kprobe_session(prog)) 3087 link->fp.entry_data_size = sizeof(u64); 3088 3089 link->addrs = addrs; 3090 link->cookies = cookies; 3091 link->cnt = cnt; 3092 link->flags = flags; 3093 3094 if (cookies) { 3095 /* 3096 * Sorting addresses will trigger sorting cookies as well 3097 * (check bpf_kprobe_multi_cookie_swap). This way we can 3098 * find cookie based on the address in bpf_get_attach_cookie 3099 * helper. 3100 */ 3101 sort_r(addrs, cnt, sizeof(*addrs), 3102 bpf_kprobe_multi_cookie_cmp, 3103 bpf_kprobe_multi_cookie_swap, 3104 link); 3105 } 3106 3107 err = get_modules_for_addrs(&link->mods, addrs, cnt); 3108 if (err < 0) { 3109 bpf_link_cleanup(&link_primer); 3110 return err; 3111 } 3112 link->mods_cnt = err; 3113 3114 err = register_fprobe_ips(&link->fp, addrs, cnt); 3115 if (err) { 3116 kprobe_multi_put_modules(link->mods, link->mods_cnt); 3117 bpf_link_cleanup(&link_primer); 3118 return err; 3119 } 3120 3121 return bpf_link_settle(&link_primer); 3122 3123 error: 3124 kfree(link); 3125 kvfree(addrs); 3126 kvfree(cookies); 3127 return err; 3128 } 3129 #else /* !CONFIG_FPROBE */ 3130 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 3131 { 3132 return -EOPNOTSUPP; 3133 } 3134 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx) 3135 { 3136 return 0; 3137 } 3138 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 3139 { 3140 return 0; 3141 } 3142 #endif 3143 3144 #ifdef CONFIG_UPROBES 3145 struct bpf_uprobe_multi_link; 3146 3147 struct bpf_uprobe { 3148 struct bpf_uprobe_multi_link *link; 3149 loff_t offset; 3150 unsigned long ref_ctr_offset; 3151 u64 cookie; 3152 struct uprobe *uprobe; 3153 struct uprobe_consumer consumer; 3154 bool session; 3155 }; 3156 3157 struct bpf_uprobe_multi_link { 3158 struct path path; 3159 struct bpf_link link; 3160 u32 cnt; 3161 u32 flags; 3162 struct bpf_uprobe *uprobes; 3163 struct task_struct *task; 3164 }; 3165 3166 struct bpf_uprobe_multi_run_ctx { 3167 struct bpf_session_run_ctx session_ctx; 3168 unsigned long entry_ip; 3169 struct bpf_uprobe *uprobe; 3170 }; 3171 3172 static void bpf_uprobe_unregister(struct bpf_uprobe *uprobes, u32 cnt) 3173 { 3174 u32 i; 3175 3176 for (i = 0; i < cnt; i++) 3177 uprobe_unregister_nosync(uprobes[i].uprobe, &uprobes[i].consumer); 3178 3179 if (cnt) 3180 uprobe_unregister_sync(); 3181 } 3182 3183 static void bpf_uprobe_multi_link_release(struct bpf_link *link) 3184 { 3185 struct bpf_uprobe_multi_link *umulti_link; 3186 3187 umulti_link = container_of(link, struct bpf_uprobe_multi_link, link); 3188 bpf_uprobe_unregister(umulti_link->uprobes, umulti_link->cnt); 3189 if (umulti_link->task) 3190 put_task_struct(umulti_link->task); 3191 path_put(&umulti_link->path); 3192 } 3193 3194 static void bpf_uprobe_multi_link_dealloc(struct bpf_link *link) 3195 { 3196 struct bpf_uprobe_multi_link *umulti_link; 3197 3198 umulti_link = container_of(link, struct bpf_uprobe_multi_link, link); 3199 kvfree(umulti_link->uprobes); 3200 kfree(umulti_link); 3201 } 3202 3203 static int bpf_uprobe_multi_link_fill_link_info(const struct bpf_link *link, 3204 struct bpf_link_info *info) 3205 { 3206 u64 __user *uref_ctr_offsets = u64_to_user_ptr(info->uprobe_multi.ref_ctr_offsets); 3207 u64 __user *ucookies = u64_to_user_ptr(info->uprobe_multi.cookies); 3208 u64 __user *uoffsets = u64_to_user_ptr(info->uprobe_multi.offsets); 3209 u64 __user *upath = u64_to_user_ptr(info->uprobe_multi.path); 3210 u32 upath_size = info->uprobe_multi.path_size; 3211 struct bpf_uprobe_multi_link *umulti_link; 3212 u32 ucount = info->uprobe_multi.count; 3213 int err = 0, i; 3214 char *p, *buf; 3215 long left = 0; 3216 3217 if (!upath ^ !upath_size) 3218 return -EINVAL; 3219 3220 if ((uoffsets || uref_ctr_offsets || ucookies) && !ucount) 3221 return -EINVAL; 3222 3223 umulti_link = container_of(link, struct bpf_uprobe_multi_link, link); 3224 info->uprobe_multi.count = umulti_link->cnt; 3225 info->uprobe_multi.flags = umulti_link->flags; 3226 info->uprobe_multi.pid = umulti_link->task ? 3227 task_pid_nr_ns(umulti_link->task, task_active_pid_ns(current)) : 0; 3228 3229 upath_size = upath_size ? min_t(u32, upath_size, PATH_MAX) : PATH_MAX; 3230 buf = kmalloc(upath_size, GFP_KERNEL); 3231 if (!buf) 3232 return -ENOMEM; 3233 p = d_path(&umulti_link->path, buf, upath_size); 3234 if (IS_ERR(p)) { 3235 kfree(buf); 3236 return PTR_ERR(p); 3237 } 3238 upath_size = buf + upath_size - p; 3239 3240 if (upath) 3241 left = copy_to_user(upath, p, upath_size); 3242 kfree(buf); 3243 if (left) 3244 return -EFAULT; 3245 info->uprobe_multi.path_size = upath_size; 3246 3247 if (!uoffsets && !ucookies && !uref_ctr_offsets) 3248 return 0; 3249 3250 if (ucount < umulti_link->cnt) 3251 err = -ENOSPC; 3252 else 3253 ucount = umulti_link->cnt; 3254 3255 for (i = 0; i < ucount; i++) { 3256 if (uoffsets && 3257 put_user(umulti_link->uprobes[i].offset, uoffsets + i)) 3258 return -EFAULT; 3259 if (uref_ctr_offsets && 3260 put_user(umulti_link->uprobes[i].ref_ctr_offset, uref_ctr_offsets + i)) 3261 return -EFAULT; 3262 if (ucookies && 3263 put_user(umulti_link->uprobes[i].cookie, ucookies + i)) 3264 return -EFAULT; 3265 } 3266 3267 return err; 3268 } 3269 3270 static const struct bpf_link_ops bpf_uprobe_multi_link_lops = { 3271 .release = bpf_uprobe_multi_link_release, 3272 .dealloc_deferred = bpf_uprobe_multi_link_dealloc, 3273 .fill_link_info = bpf_uprobe_multi_link_fill_link_info, 3274 }; 3275 3276 static int uprobe_prog_run(struct bpf_uprobe *uprobe, 3277 unsigned long entry_ip, 3278 struct pt_regs *regs, 3279 bool is_return, void *data) 3280 { 3281 struct bpf_uprobe_multi_link *link = uprobe->link; 3282 struct bpf_uprobe_multi_run_ctx run_ctx = { 3283 .session_ctx = { 3284 .is_return = is_return, 3285 .data = data, 3286 }, 3287 .entry_ip = entry_ip, 3288 .uprobe = uprobe, 3289 }; 3290 struct bpf_prog *prog = link->link.prog; 3291 bool sleepable = prog->sleepable; 3292 struct bpf_run_ctx *old_run_ctx; 3293 int err; 3294 3295 if (link->task && !same_thread_group(current, link->task)) 3296 return 0; 3297 3298 if (sleepable) 3299 rcu_read_lock_trace(); 3300 else 3301 rcu_read_lock(); 3302 3303 migrate_disable(); 3304 3305 old_run_ctx = bpf_set_run_ctx(&run_ctx.session_ctx.run_ctx); 3306 err = bpf_prog_run(link->link.prog, regs); 3307 bpf_reset_run_ctx(old_run_ctx); 3308 3309 migrate_enable(); 3310 3311 if (sleepable) 3312 rcu_read_unlock_trace(); 3313 else 3314 rcu_read_unlock(); 3315 return err; 3316 } 3317 3318 static bool 3319 uprobe_multi_link_filter(struct uprobe_consumer *con, struct mm_struct *mm) 3320 { 3321 struct bpf_uprobe *uprobe; 3322 3323 uprobe = container_of(con, struct bpf_uprobe, consumer); 3324 return uprobe->link->task->mm == mm; 3325 } 3326 3327 static int 3328 uprobe_multi_link_handler(struct uprobe_consumer *con, struct pt_regs *regs, 3329 __u64 *data) 3330 { 3331 struct bpf_uprobe *uprobe; 3332 int ret; 3333 3334 uprobe = container_of(con, struct bpf_uprobe, consumer); 3335 ret = uprobe_prog_run(uprobe, instruction_pointer(regs), regs, false, data); 3336 if (uprobe->session) 3337 return ret ? UPROBE_HANDLER_IGNORE : 0; 3338 return 0; 3339 } 3340 3341 static int 3342 uprobe_multi_link_ret_handler(struct uprobe_consumer *con, unsigned long func, struct pt_regs *regs, 3343 __u64 *data) 3344 { 3345 struct bpf_uprobe *uprobe; 3346 3347 uprobe = container_of(con, struct bpf_uprobe, consumer); 3348 uprobe_prog_run(uprobe, func, regs, true, data); 3349 return 0; 3350 } 3351 3352 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 3353 { 3354 struct bpf_uprobe_multi_run_ctx *run_ctx; 3355 3356 run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx, 3357 session_ctx.run_ctx); 3358 return run_ctx->entry_ip; 3359 } 3360 3361 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx) 3362 { 3363 struct bpf_uprobe_multi_run_ctx *run_ctx; 3364 3365 run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx, 3366 session_ctx.run_ctx); 3367 return run_ctx->uprobe->cookie; 3368 } 3369 3370 int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 3371 { 3372 struct bpf_uprobe_multi_link *link = NULL; 3373 unsigned long __user *uref_ctr_offsets; 3374 struct bpf_link_primer link_primer; 3375 struct bpf_uprobe *uprobes = NULL; 3376 struct task_struct *task = NULL; 3377 unsigned long __user *uoffsets; 3378 u64 __user *ucookies; 3379 void __user *upath; 3380 u32 flags, cnt, i; 3381 struct path path; 3382 char *name; 3383 pid_t pid; 3384 int err; 3385 3386 /* no support for 32bit archs yet */ 3387 if (sizeof(u64) != sizeof(void *)) 3388 return -EOPNOTSUPP; 3389 3390 if (!is_uprobe_multi(prog)) 3391 return -EINVAL; 3392 3393 flags = attr->link_create.uprobe_multi.flags; 3394 if (flags & ~BPF_F_UPROBE_MULTI_RETURN) 3395 return -EINVAL; 3396 3397 /* 3398 * path, offsets and cnt are mandatory, 3399 * ref_ctr_offsets and cookies are optional 3400 */ 3401 upath = u64_to_user_ptr(attr->link_create.uprobe_multi.path); 3402 uoffsets = u64_to_user_ptr(attr->link_create.uprobe_multi.offsets); 3403 cnt = attr->link_create.uprobe_multi.cnt; 3404 pid = attr->link_create.uprobe_multi.pid; 3405 3406 if (!upath || !uoffsets || !cnt || pid < 0) 3407 return -EINVAL; 3408 if (cnt > MAX_UPROBE_MULTI_CNT) 3409 return -E2BIG; 3410 3411 uref_ctr_offsets = u64_to_user_ptr(attr->link_create.uprobe_multi.ref_ctr_offsets); 3412 ucookies = u64_to_user_ptr(attr->link_create.uprobe_multi.cookies); 3413 3414 name = strndup_user(upath, PATH_MAX); 3415 if (IS_ERR(name)) { 3416 err = PTR_ERR(name); 3417 return err; 3418 } 3419 3420 err = kern_path(name, LOOKUP_FOLLOW, &path); 3421 kfree(name); 3422 if (err) 3423 return err; 3424 3425 if (!d_is_reg(path.dentry)) { 3426 err = -EBADF; 3427 goto error_path_put; 3428 } 3429 3430 if (pid) { 3431 task = get_pid_task(find_vpid(pid), PIDTYPE_TGID); 3432 if (!task) { 3433 err = -ESRCH; 3434 goto error_path_put; 3435 } 3436 } 3437 3438 err = -ENOMEM; 3439 3440 link = kzalloc(sizeof(*link), GFP_KERNEL); 3441 uprobes = kvcalloc(cnt, sizeof(*uprobes), GFP_KERNEL); 3442 3443 if (!uprobes || !link) 3444 goto error_free; 3445 3446 for (i = 0; i < cnt; i++) { 3447 if (__get_user(uprobes[i].offset, uoffsets + i)) { 3448 err = -EFAULT; 3449 goto error_free; 3450 } 3451 if (uprobes[i].offset < 0) { 3452 err = -EINVAL; 3453 goto error_free; 3454 } 3455 if (uref_ctr_offsets && __get_user(uprobes[i].ref_ctr_offset, uref_ctr_offsets + i)) { 3456 err = -EFAULT; 3457 goto error_free; 3458 } 3459 if (ucookies && __get_user(uprobes[i].cookie, ucookies + i)) { 3460 err = -EFAULT; 3461 goto error_free; 3462 } 3463 3464 uprobes[i].link = link; 3465 3466 if (!(flags & BPF_F_UPROBE_MULTI_RETURN)) 3467 uprobes[i].consumer.handler = uprobe_multi_link_handler; 3468 if (flags & BPF_F_UPROBE_MULTI_RETURN || is_uprobe_session(prog)) 3469 uprobes[i].consumer.ret_handler = uprobe_multi_link_ret_handler; 3470 if (is_uprobe_session(prog)) 3471 uprobes[i].session = true; 3472 if (pid) 3473 uprobes[i].consumer.filter = uprobe_multi_link_filter; 3474 } 3475 3476 link->cnt = cnt; 3477 link->uprobes = uprobes; 3478 link->path = path; 3479 link->task = task; 3480 link->flags = flags; 3481 3482 bpf_link_init(&link->link, BPF_LINK_TYPE_UPROBE_MULTI, 3483 &bpf_uprobe_multi_link_lops, prog); 3484 3485 for (i = 0; i < cnt; i++) { 3486 uprobes[i].uprobe = uprobe_register(d_real_inode(link->path.dentry), 3487 uprobes[i].offset, 3488 uprobes[i].ref_ctr_offset, 3489 &uprobes[i].consumer); 3490 if (IS_ERR(uprobes[i].uprobe)) { 3491 err = PTR_ERR(uprobes[i].uprobe); 3492 link->cnt = i; 3493 goto error_unregister; 3494 } 3495 } 3496 3497 err = bpf_link_prime(&link->link, &link_primer); 3498 if (err) 3499 goto error_unregister; 3500 3501 return bpf_link_settle(&link_primer); 3502 3503 error_unregister: 3504 bpf_uprobe_unregister(uprobes, link->cnt); 3505 3506 error_free: 3507 kvfree(uprobes); 3508 kfree(link); 3509 if (task) 3510 put_task_struct(task); 3511 error_path_put: 3512 path_put(&path); 3513 return err; 3514 } 3515 #else /* !CONFIG_UPROBES */ 3516 int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 3517 { 3518 return -EOPNOTSUPP; 3519 } 3520 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx) 3521 { 3522 return 0; 3523 } 3524 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 3525 { 3526 return 0; 3527 } 3528 #endif /* CONFIG_UPROBES */ 3529 3530 __bpf_kfunc_start_defs(); 3531 3532 __bpf_kfunc bool bpf_session_is_return(void) 3533 { 3534 struct bpf_session_run_ctx *session_ctx; 3535 3536 session_ctx = container_of(current->bpf_ctx, struct bpf_session_run_ctx, run_ctx); 3537 return session_ctx->is_return; 3538 } 3539 3540 __bpf_kfunc __u64 *bpf_session_cookie(void) 3541 { 3542 struct bpf_session_run_ctx *session_ctx; 3543 3544 session_ctx = container_of(current->bpf_ctx, struct bpf_session_run_ctx, run_ctx); 3545 return session_ctx->data; 3546 } 3547 3548 __bpf_kfunc_end_defs(); 3549 3550 BTF_KFUNCS_START(kprobe_multi_kfunc_set_ids) 3551 BTF_ID_FLAGS(func, bpf_session_is_return) 3552 BTF_ID_FLAGS(func, bpf_session_cookie) 3553 BTF_KFUNCS_END(kprobe_multi_kfunc_set_ids) 3554 3555 static int bpf_kprobe_multi_filter(const struct bpf_prog *prog, u32 kfunc_id) 3556 { 3557 if (!btf_id_set8_contains(&kprobe_multi_kfunc_set_ids, kfunc_id)) 3558 return 0; 3559 3560 if (!is_kprobe_session(prog) && !is_uprobe_session(prog)) 3561 return -EACCES; 3562 3563 return 0; 3564 } 3565 3566 static const struct btf_kfunc_id_set bpf_kprobe_multi_kfunc_set = { 3567 .owner = THIS_MODULE, 3568 .set = &kprobe_multi_kfunc_set_ids, 3569 .filter = bpf_kprobe_multi_filter, 3570 }; 3571 3572 static int __init bpf_kprobe_multi_kfuncs_init(void) 3573 { 3574 return register_btf_kfunc_id_set(BPF_PROG_TYPE_KPROBE, &bpf_kprobe_multi_kfunc_set); 3575 } 3576 3577 late_initcall(bpf_kprobe_multi_kfuncs_init); 3578 3579 __bpf_kfunc_start_defs(); 3580 3581 __bpf_kfunc int bpf_send_signal_task(struct task_struct *task, int sig, enum pid_type type, 3582 u64 value) 3583 { 3584 if (type != PIDTYPE_PID && type != PIDTYPE_TGID) 3585 return -EINVAL; 3586 3587 return bpf_send_signal_common(sig, type, task, value); 3588 } 3589 3590 __bpf_kfunc_end_defs(); 3591