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 bpf_get_raw_tracepoint_module(const char * name)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 bpf_get_raw_tracepoint_module(const char * name)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 */ trace_call_bpf(struct trace_event_call * call,void * ctx)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 BPF_CALL_2(bpf_override_return,struct pt_regs *,regs,unsigned long,rc)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 bpf_probe_read_user_common(void * dst,u32 size,const void __user * unsafe_ptr)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 BPF_CALL_3(bpf_probe_read_user,void *,dst,u32,size,const void __user *,unsafe_ptr)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 bpf_probe_read_user_str_common(void * dst,u32 size,const void __user * unsafe_ptr)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 BPF_CALL_3(bpf_probe_read_user_str,void *,dst,u32,size,const void __user *,unsafe_ptr)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 BPF_CALL_3(bpf_probe_read_kernel,void *,dst,u32,size,const void *,unsafe_ptr)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 bpf_probe_read_kernel_str_common(void * dst,u32 size,const void * unsafe_ptr)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 BPF_CALL_3(bpf_probe_read_kernel_str,void *,dst,u32,size,const void *,unsafe_ptr)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 BPF_CALL_3(bpf_probe_read_compat,void *,dst,u32,size,const void *,unsafe_ptr)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 BPF_CALL_3(bpf_probe_read_compat_str,void *,dst,u32,size,const void *,unsafe_ptr)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 BPF_CALL_3(bpf_probe_write_user,void __user *,unsafe_ptr,const void *,src,u32,size)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 BPF_CALL_5(bpf_trace_printk,char *,fmt,u32,fmt_size,u64,arg1,u64,arg2,u64,arg3)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 __set_printk_clr_event(void)395 static void __set_printk_clr_event(void) 396 { 397 /* 398 * This program might be calling bpf_trace_printk, 399 * so enable the associated bpf_trace/bpf_trace_printk event. 400 * Repeat this each time as it is possible a user has 401 * disabled bpf_trace_printk events. By loading a program 402 * calling bpf_trace_printk() however the user has expressed 403 * the intent to see such events. 404 */ 405 if (trace_set_clr_event("bpf_trace", "bpf_trace_printk", 1)) 406 pr_warn_ratelimited("could not enable bpf_trace_printk events"); 407 } 408 bpf_get_trace_printk_proto(void)409 const struct bpf_func_proto *bpf_get_trace_printk_proto(void) 410 { 411 __set_printk_clr_event(); 412 return &bpf_trace_printk_proto; 413 } 414 BPF_CALL_4(bpf_trace_vprintk,char *,fmt,u32,fmt_size,const void *,args,u32,data_len)415 BPF_CALL_4(bpf_trace_vprintk, char *, fmt, u32, fmt_size, const void *, args, 416 u32, data_len) 417 { 418 struct bpf_bprintf_data data = { 419 .get_bin_args = true, 420 .get_buf = true, 421 }; 422 int ret, num_args; 423 424 if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 || 425 (data_len && !args)) 426 return -EINVAL; 427 num_args = data_len / 8; 428 429 ret = bpf_bprintf_prepare(fmt, fmt_size, args, num_args, &data); 430 if (ret < 0) 431 return ret; 432 433 ret = bstr_printf(data.buf, MAX_BPRINTF_BUF, fmt, data.bin_args); 434 435 trace_bpf_trace_printk(data.buf); 436 437 bpf_bprintf_cleanup(&data); 438 439 return ret; 440 } 441 442 static const struct bpf_func_proto bpf_trace_vprintk_proto = { 443 .func = bpf_trace_vprintk, 444 .gpl_only = true, 445 .ret_type = RET_INTEGER, 446 .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY, 447 .arg2_type = ARG_CONST_SIZE, 448 .arg3_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY, 449 .arg4_type = ARG_CONST_SIZE_OR_ZERO, 450 }; 451 bpf_get_trace_vprintk_proto(void)452 const struct bpf_func_proto *bpf_get_trace_vprintk_proto(void) 453 { 454 __set_printk_clr_event(); 455 return &bpf_trace_vprintk_proto; 456 } 457 BPF_CALL_5(bpf_seq_printf,struct seq_file *,m,char *,fmt,u32,fmt_size,const void *,args,u32,data_len)458 BPF_CALL_5(bpf_seq_printf, struct seq_file *, m, char *, fmt, u32, fmt_size, 459 const void *, args, u32, data_len) 460 { 461 struct bpf_bprintf_data data = { 462 .get_bin_args = true, 463 }; 464 int err, num_args; 465 466 if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 || 467 (data_len && !args)) 468 return -EINVAL; 469 num_args = data_len / 8; 470 471 err = bpf_bprintf_prepare(fmt, fmt_size, args, num_args, &data); 472 if (err < 0) 473 return err; 474 475 seq_bprintf(m, fmt, data.bin_args); 476 477 bpf_bprintf_cleanup(&data); 478 479 return seq_has_overflowed(m) ? -EOVERFLOW : 0; 480 } 481 482 BTF_ID_LIST_SINGLE(btf_seq_file_ids, struct, seq_file) 483 484 static const struct bpf_func_proto bpf_seq_printf_proto = { 485 .func = bpf_seq_printf, 486 .gpl_only = true, 487 .ret_type = RET_INTEGER, 488 .arg1_type = ARG_PTR_TO_BTF_ID, 489 .arg1_btf_id = &btf_seq_file_ids[0], 490 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 491 .arg3_type = ARG_CONST_SIZE, 492 .arg4_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY, 493 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 494 }; 495 BPF_CALL_3(bpf_seq_write,struct seq_file *,m,const void *,data,u32,len)496 BPF_CALL_3(bpf_seq_write, struct seq_file *, m, const void *, data, u32, len) 497 { 498 return seq_write(m, data, len) ? -EOVERFLOW : 0; 499 } 500 501 static const struct bpf_func_proto bpf_seq_write_proto = { 502 .func = bpf_seq_write, 503 .gpl_only = true, 504 .ret_type = RET_INTEGER, 505 .arg1_type = ARG_PTR_TO_BTF_ID, 506 .arg1_btf_id = &btf_seq_file_ids[0], 507 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 508 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 509 }; 510 BPF_CALL_4(bpf_seq_printf_btf,struct seq_file *,m,struct btf_ptr *,ptr,u32,btf_ptr_size,u64,flags)511 BPF_CALL_4(bpf_seq_printf_btf, struct seq_file *, m, struct btf_ptr *, ptr, 512 u32, btf_ptr_size, u64, flags) 513 { 514 const struct btf *btf; 515 s32 btf_id; 516 int ret; 517 518 ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id); 519 if (ret) 520 return ret; 521 522 return btf_type_seq_show_flags(btf, btf_id, ptr->ptr, m, flags); 523 } 524 525 static const struct bpf_func_proto bpf_seq_printf_btf_proto = { 526 .func = bpf_seq_printf_btf, 527 .gpl_only = true, 528 .ret_type = RET_INTEGER, 529 .arg1_type = ARG_PTR_TO_BTF_ID, 530 .arg1_btf_id = &btf_seq_file_ids[0], 531 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 532 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 533 .arg4_type = ARG_ANYTHING, 534 }; 535 536 static __always_inline int get_map_perf_counter(struct bpf_map * map,u64 flags,u64 * value,u64 * enabled,u64 * running)537 get_map_perf_counter(struct bpf_map *map, u64 flags, 538 u64 *value, u64 *enabled, u64 *running) 539 { 540 struct bpf_array *array = container_of(map, struct bpf_array, map); 541 unsigned int cpu = smp_processor_id(); 542 u64 index = flags & BPF_F_INDEX_MASK; 543 struct bpf_event_entry *ee; 544 545 if (unlikely(flags & ~(BPF_F_INDEX_MASK))) 546 return -EINVAL; 547 if (index == BPF_F_CURRENT_CPU) 548 index = cpu; 549 if (unlikely(index >= array->map.max_entries)) 550 return -E2BIG; 551 552 ee = READ_ONCE(array->ptrs[index]); 553 if (!ee) 554 return -ENOENT; 555 556 return perf_event_read_local(ee->event, value, enabled, running); 557 } 558 BPF_CALL_2(bpf_perf_event_read,struct bpf_map *,map,u64,flags)559 BPF_CALL_2(bpf_perf_event_read, struct bpf_map *, map, u64, flags) 560 { 561 u64 value = 0; 562 int err; 563 564 err = get_map_perf_counter(map, flags, &value, NULL, NULL); 565 /* 566 * this api is ugly since we miss [-22..-2] range of valid 567 * counter values, but that's uapi 568 */ 569 if (err) 570 return err; 571 return value; 572 } 573 574 static const struct bpf_func_proto bpf_perf_event_read_proto = { 575 .func = bpf_perf_event_read, 576 .gpl_only = true, 577 .ret_type = RET_INTEGER, 578 .arg1_type = ARG_CONST_MAP_PTR, 579 .arg2_type = ARG_ANYTHING, 580 }; 581 BPF_CALL_4(bpf_perf_event_read_value,struct bpf_map *,map,u64,flags,struct bpf_perf_event_value *,buf,u32,size)582 BPF_CALL_4(bpf_perf_event_read_value, struct bpf_map *, map, u64, flags, 583 struct bpf_perf_event_value *, buf, u32, size) 584 { 585 int err = -EINVAL; 586 587 if (unlikely(size != sizeof(struct bpf_perf_event_value))) 588 goto clear; 589 err = get_map_perf_counter(map, flags, &buf->counter, &buf->enabled, 590 &buf->running); 591 if (unlikely(err)) 592 goto clear; 593 return 0; 594 clear: 595 memset(buf, 0, size); 596 return err; 597 } 598 599 static const struct bpf_func_proto bpf_perf_event_read_value_proto = { 600 .func = bpf_perf_event_read_value, 601 .gpl_only = true, 602 .ret_type = RET_INTEGER, 603 .arg1_type = ARG_CONST_MAP_PTR, 604 .arg2_type = ARG_ANYTHING, 605 .arg3_type = ARG_PTR_TO_UNINIT_MEM, 606 .arg4_type = ARG_CONST_SIZE, 607 }; 608 609 static __always_inline u64 __bpf_perf_event_output(struct pt_regs * regs,struct bpf_map * map,u64 flags,struct perf_raw_record * raw,struct perf_sample_data * sd)610 __bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map, 611 u64 flags, struct perf_raw_record *raw, 612 struct perf_sample_data *sd) 613 { 614 struct bpf_array *array = container_of(map, struct bpf_array, map); 615 unsigned int cpu = smp_processor_id(); 616 u64 index = flags & BPF_F_INDEX_MASK; 617 struct bpf_event_entry *ee; 618 struct perf_event *event; 619 620 if (index == BPF_F_CURRENT_CPU) 621 index = cpu; 622 if (unlikely(index >= array->map.max_entries)) 623 return -E2BIG; 624 625 ee = READ_ONCE(array->ptrs[index]); 626 if (!ee) 627 return -ENOENT; 628 629 event = ee->event; 630 if (unlikely(event->attr.type != PERF_TYPE_SOFTWARE || 631 event->attr.config != PERF_COUNT_SW_BPF_OUTPUT)) 632 return -EINVAL; 633 634 if (unlikely(event->oncpu != cpu)) 635 return -EOPNOTSUPP; 636 637 perf_sample_save_raw_data(sd, event, raw); 638 639 return perf_event_output(event, sd, regs); 640 } 641 642 /* 643 * Support executing tracepoints in normal, irq, and nmi context that each call 644 * bpf_perf_event_output 645 */ 646 struct bpf_trace_sample_data { 647 struct perf_sample_data sds[3]; 648 }; 649 650 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_trace_sds); 651 static DEFINE_PER_CPU(int, bpf_trace_nest_level); BPF_CALL_5(bpf_perf_event_output,struct pt_regs *,regs,struct bpf_map *,map,u64,flags,void *,data,u64,size)652 BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map, 653 u64, flags, void *, data, u64, size) 654 { 655 struct bpf_trace_sample_data *sds; 656 struct perf_raw_record raw = { 657 .frag = { 658 .size = size, 659 .data = data, 660 }, 661 }; 662 struct perf_sample_data *sd; 663 int nest_level, err; 664 665 preempt_disable(); 666 sds = this_cpu_ptr(&bpf_trace_sds); 667 nest_level = this_cpu_inc_return(bpf_trace_nest_level); 668 669 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(sds->sds))) { 670 err = -EBUSY; 671 goto out; 672 } 673 674 sd = &sds->sds[nest_level - 1]; 675 676 if (unlikely(flags & ~(BPF_F_INDEX_MASK))) { 677 err = -EINVAL; 678 goto out; 679 } 680 681 perf_sample_data_init(sd, 0, 0); 682 683 err = __bpf_perf_event_output(regs, map, flags, &raw, sd); 684 out: 685 this_cpu_dec(bpf_trace_nest_level); 686 preempt_enable(); 687 return err; 688 } 689 690 static const struct bpf_func_proto bpf_perf_event_output_proto = { 691 .func = bpf_perf_event_output, 692 .gpl_only = true, 693 .ret_type = RET_INTEGER, 694 .arg1_type = ARG_PTR_TO_CTX, 695 .arg2_type = ARG_CONST_MAP_PTR, 696 .arg3_type = ARG_ANYTHING, 697 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, 698 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 699 }; 700 701 static DEFINE_PER_CPU(int, bpf_event_output_nest_level); 702 struct bpf_nested_pt_regs { 703 struct pt_regs regs[3]; 704 }; 705 static DEFINE_PER_CPU(struct bpf_nested_pt_regs, bpf_pt_regs); 706 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_misc_sds); 707 bpf_event_output(struct bpf_map * map,u64 flags,void * meta,u64 meta_size,void * ctx,u64 ctx_size,bpf_ctx_copy_t ctx_copy)708 u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size, 709 void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy) 710 { 711 struct perf_raw_frag frag = { 712 .copy = ctx_copy, 713 .size = ctx_size, 714 .data = ctx, 715 }; 716 struct perf_raw_record raw = { 717 .frag = { 718 { 719 .next = ctx_size ? &frag : NULL, 720 }, 721 .size = meta_size, 722 .data = meta, 723 }, 724 }; 725 struct perf_sample_data *sd; 726 struct pt_regs *regs; 727 int nest_level; 728 u64 ret; 729 730 preempt_disable(); 731 nest_level = this_cpu_inc_return(bpf_event_output_nest_level); 732 733 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(bpf_misc_sds.sds))) { 734 ret = -EBUSY; 735 goto out; 736 } 737 sd = this_cpu_ptr(&bpf_misc_sds.sds[nest_level - 1]); 738 regs = this_cpu_ptr(&bpf_pt_regs.regs[nest_level - 1]); 739 740 perf_fetch_caller_regs(regs); 741 perf_sample_data_init(sd, 0, 0); 742 743 ret = __bpf_perf_event_output(regs, map, flags, &raw, sd); 744 out: 745 this_cpu_dec(bpf_event_output_nest_level); 746 preempt_enable(); 747 return ret; 748 } 749 BPF_CALL_0(bpf_get_current_task)750 BPF_CALL_0(bpf_get_current_task) 751 { 752 return (long) current; 753 } 754 755 const struct bpf_func_proto bpf_get_current_task_proto = { 756 .func = bpf_get_current_task, 757 .gpl_only = true, 758 .ret_type = RET_INTEGER, 759 }; 760 BPF_CALL_0(bpf_get_current_task_btf)761 BPF_CALL_0(bpf_get_current_task_btf) 762 { 763 return (unsigned long) current; 764 } 765 766 const struct bpf_func_proto bpf_get_current_task_btf_proto = { 767 .func = bpf_get_current_task_btf, 768 .gpl_only = true, 769 .ret_type = RET_PTR_TO_BTF_ID_TRUSTED, 770 .ret_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK], 771 }; 772 BPF_CALL_1(bpf_task_pt_regs,struct task_struct *,task)773 BPF_CALL_1(bpf_task_pt_regs, struct task_struct *, task) 774 { 775 return (unsigned long) task_pt_regs(task); 776 } 777 778 BTF_ID_LIST(bpf_task_pt_regs_ids) 779 BTF_ID(struct, pt_regs) 780 781 const struct bpf_func_proto bpf_task_pt_regs_proto = { 782 .func = bpf_task_pt_regs, 783 .gpl_only = true, 784 .arg1_type = ARG_PTR_TO_BTF_ID, 785 .arg1_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK], 786 .ret_type = RET_PTR_TO_BTF_ID, 787 .ret_btf_id = &bpf_task_pt_regs_ids[0], 788 }; 789 790 struct send_signal_irq_work { 791 struct irq_work irq_work; 792 struct task_struct *task; 793 u32 sig; 794 enum pid_type type; 795 bool has_siginfo; 796 struct kernel_siginfo info; 797 }; 798 799 static DEFINE_PER_CPU(struct send_signal_irq_work, send_signal_work); 800 do_bpf_send_signal(struct irq_work * entry)801 static void do_bpf_send_signal(struct irq_work *entry) 802 { 803 struct send_signal_irq_work *work; 804 struct kernel_siginfo *siginfo; 805 806 work = container_of(entry, struct send_signal_irq_work, irq_work); 807 siginfo = work->has_siginfo ? &work->info : SEND_SIG_PRIV; 808 809 group_send_sig_info(work->sig, siginfo, work->task, work->type); 810 put_task_struct(work->task); 811 } 812 bpf_send_signal_common(u32 sig,enum pid_type type,struct task_struct * task,u64 value)813 static int bpf_send_signal_common(u32 sig, enum pid_type type, struct task_struct *task, u64 value) 814 { 815 struct send_signal_irq_work *work = NULL; 816 struct kernel_siginfo info; 817 struct kernel_siginfo *siginfo; 818 819 if (!task) { 820 task = current; 821 siginfo = SEND_SIG_PRIV; 822 } else { 823 clear_siginfo(&info); 824 info.si_signo = sig; 825 info.si_errno = 0; 826 info.si_code = SI_KERNEL; 827 info.si_pid = 0; 828 info.si_uid = 0; 829 info.si_value.sival_ptr = (void *)(unsigned long)value; 830 siginfo = &info; 831 } 832 833 /* Similar to bpf_probe_write_user, task needs to be 834 * in a sound condition and kernel memory access be 835 * permitted in order to send signal to the current 836 * task. 837 */ 838 if (unlikely(task->flags & (PF_KTHREAD | PF_EXITING))) 839 return -EPERM; 840 if (unlikely(!nmi_uaccess_okay())) 841 return -EPERM; 842 /* Task should not be pid=1 to avoid kernel panic. */ 843 if (unlikely(is_global_init(task))) 844 return -EPERM; 845 846 if (!preemptible()) { 847 /* Do an early check on signal validity. Otherwise, 848 * the error is lost in deferred irq_work. 849 */ 850 if (unlikely(!valid_signal(sig))) 851 return -EINVAL; 852 853 work = this_cpu_ptr(&send_signal_work); 854 if (irq_work_is_busy(&work->irq_work)) 855 return -EBUSY; 856 857 /* Add the current task, which is the target of sending signal, 858 * to the irq_work. The current task may change when queued 859 * irq works get executed. 860 */ 861 work->task = get_task_struct(task); 862 work->has_siginfo = siginfo == &info; 863 if (work->has_siginfo) 864 copy_siginfo(&work->info, &info); 865 work->sig = sig; 866 work->type = type; 867 irq_work_queue(&work->irq_work); 868 return 0; 869 } 870 871 return group_send_sig_info(sig, siginfo, task, type); 872 } 873 BPF_CALL_1(bpf_send_signal,u32,sig)874 BPF_CALL_1(bpf_send_signal, u32, sig) 875 { 876 return bpf_send_signal_common(sig, PIDTYPE_TGID, NULL, 0); 877 } 878 879 static const struct bpf_func_proto bpf_send_signal_proto = { 880 .func = bpf_send_signal, 881 .gpl_only = false, 882 .ret_type = RET_INTEGER, 883 .arg1_type = ARG_ANYTHING, 884 }; 885 BPF_CALL_1(bpf_send_signal_thread,u32,sig)886 BPF_CALL_1(bpf_send_signal_thread, u32, sig) 887 { 888 return bpf_send_signal_common(sig, PIDTYPE_PID, NULL, 0); 889 } 890 891 static const struct bpf_func_proto bpf_send_signal_thread_proto = { 892 .func = bpf_send_signal_thread, 893 .gpl_only = false, 894 .ret_type = RET_INTEGER, 895 .arg1_type = ARG_ANYTHING, 896 }; 897 BPF_CALL_3(bpf_d_path,struct path *,path,char *,buf,u32,sz)898 BPF_CALL_3(bpf_d_path, struct path *, path, char *, buf, u32, sz) 899 { 900 struct path copy; 901 long len; 902 char *p; 903 904 if (!sz) 905 return 0; 906 907 /* 908 * The path pointer is verified as trusted and safe to use, 909 * but let's double check it's valid anyway to workaround 910 * potentially broken verifier. 911 */ 912 len = copy_from_kernel_nofault(©, path, sizeof(*path)); 913 if (len < 0) 914 return len; 915 916 p = d_path(©, buf, sz); 917 if (IS_ERR(p)) { 918 len = PTR_ERR(p); 919 } else { 920 len = buf + sz - p; 921 memmove(buf, p, len); 922 } 923 924 return len; 925 } 926 927 BTF_SET_START(btf_allowlist_d_path) 928 #ifdef CONFIG_SECURITY BTF_ID(func,security_file_permission)929 BTF_ID(func, security_file_permission) 930 BTF_ID(func, security_inode_getattr) 931 BTF_ID(func, security_file_open) 932 #endif 933 #ifdef CONFIG_SECURITY_PATH 934 BTF_ID(func, security_path_truncate) 935 #endif 936 BTF_ID(func, vfs_truncate) 937 BTF_ID(func, vfs_fallocate) 938 BTF_ID(func, dentry_open) 939 BTF_ID(func, vfs_getattr) 940 BTF_ID(func, filp_close) 941 BTF_SET_END(btf_allowlist_d_path) 942 943 static bool bpf_d_path_allowed(const struct bpf_prog *prog) 944 { 945 if (prog->type == BPF_PROG_TYPE_TRACING && 946 prog->expected_attach_type == BPF_TRACE_ITER) 947 return true; 948 949 if (prog->type == BPF_PROG_TYPE_LSM) 950 return bpf_lsm_is_sleepable_hook(prog->aux->attach_btf_id); 951 952 return btf_id_set_contains(&btf_allowlist_d_path, 953 prog->aux->attach_btf_id); 954 } 955 956 BTF_ID_LIST_SINGLE(bpf_d_path_btf_ids, struct, path) 957 958 static const struct bpf_func_proto bpf_d_path_proto = { 959 .func = bpf_d_path, 960 .gpl_only = false, 961 .ret_type = RET_INTEGER, 962 .arg1_type = ARG_PTR_TO_BTF_ID, 963 .arg1_btf_id = &bpf_d_path_btf_ids[0], 964 .arg2_type = ARG_PTR_TO_MEM, 965 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 966 .allowed = bpf_d_path_allowed, 967 }; 968 969 #define BTF_F_ALL (BTF_F_COMPACT | BTF_F_NONAME | \ 970 BTF_F_PTR_RAW | BTF_F_ZERO) 971 bpf_btf_printf_prepare(struct btf_ptr * ptr,u32 btf_ptr_size,u64 flags,const struct btf ** btf,s32 * btf_id)972 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size, 973 u64 flags, const struct btf **btf, 974 s32 *btf_id) 975 { 976 const struct btf_type *t; 977 978 if (unlikely(flags & ~(BTF_F_ALL))) 979 return -EINVAL; 980 981 if (btf_ptr_size != sizeof(struct btf_ptr)) 982 return -EINVAL; 983 984 *btf = bpf_get_btf_vmlinux(); 985 986 if (IS_ERR_OR_NULL(*btf)) 987 return IS_ERR(*btf) ? PTR_ERR(*btf) : -EINVAL; 988 989 if (ptr->type_id > 0) 990 *btf_id = ptr->type_id; 991 else 992 return -EINVAL; 993 994 if (*btf_id > 0) 995 t = btf_type_by_id(*btf, *btf_id); 996 if (*btf_id <= 0 || !t) 997 return -ENOENT; 998 999 return 0; 1000 } 1001 BPF_CALL_5(bpf_snprintf_btf,char *,str,u32,str_size,struct btf_ptr *,ptr,u32,btf_ptr_size,u64,flags)1002 BPF_CALL_5(bpf_snprintf_btf, char *, str, u32, str_size, struct btf_ptr *, ptr, 1003 u32, btf_ptr_size, u64, flags) 1004 { 1005 const struct btf *btf; 1006 s32 btf_id; 1007 int ret; 1008 1009 ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id); 1010 if (ret) 1011 return ret; 1012 1013 return btf_type_snprintf_show(btf, btf_id, ptr->ptr, str, str_size, 1014 flags); 1015 } 1016 1017 const struct bpf_func_proto bpf_snprintf_btf_proto = { 1018 .func = bpf_snprintf_btf, 1019 .gpl_only = false, 1020 .ret_type = RET_INTEGER, 1021 .arg1_type = ARG_PTR_TO_MEM, 1022 .arg2_type = ARG_CONST_SIZE, 1023 .arg3_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1024 .arg4_type = ARG_CONST_SIZE, 1025 .arg5_type = ARG_ANYTHING, 1026 }; 1027 BPF_CALL_1(bpf_get_func_ip_tracing,void *,ctx)1028 BPF_CALL_1(bpf_get_func_ip_tracing, void *, ctx) 1029 { 1030 /* This helper call is inlined by verifier. */ 1031 return ((u64 *)ctx)[-2]; 1032 } 1033 1034 static const struct bpf_func_proto bpf_get_func_ip_proto_tracing = { 1035 .func = bpf_get_func_ip_tracing, 1036 .gpl_only = true, 1037 .ret_type = RET_INTEGER, 1038 .arg1_type = ARG_PTR_TO_CTX, 1039 }; 1040 get_entry_ip(unsigned long fentry_ip)1041 static inline unsigned long get_entry_ip(unsigned long fentry_ip) 1042 { 1043 #ifdef CONFIG_X86_KERNEL_IBT 1044 if (is_endbr((void *)(fentry_ip - ENDBR_INSN_SIZE))) 1045 fentry_ip -= ENDBR_INSN_SIZE; 1046 #endif 1047 return fentry_ip; 1048 } 1049 BPF_CALL_1(bpf_get_func_ip_kprobe,struct pt_regs *,regs)1050 BPF_CALL_1(bpf_get_func_ip_kprobe, struct pt_regs *, regs) 1051 { 1052 struct bpf_trace_run_ctx *run_ctx __maybe_unused; 1053 struct kprobe *kp; 1054 1055 #ifdef CONFIG_UPROBES 1056 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); 1057 if (run_ctx->is_uprobe) 1058 return ((struct uprobe_dispatch_data *)current->utask->vaddr)->bp_addr; 1059 #endif 1060 1061 kp = kprobe_running(); 1062 1063 if (!kp || !(kp->flags & KPROBE_FLAG_ON_FUNC_ENTRY)) 1064 return 0; 1065 1066 return get_entry_ip((uintptr_t)kp->addr); 1067 } 1068 1069 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe = { 1070 .func = bpf_get_func_ip_kprobe, 1071 .gpl_only = true, 1072 .ret_type = RET_INTEGER, 1073 .arg1_type = ARG_PTR_TO_CTX, 1074 }; 1075 BPF_CALL_1(bpf_get_func_ip_kprobe_multi,struct pt_regs *,regs)1076 BPF_CALL_1(bpf_get_func_ip_kprobe_multi, struct pt_regs *, regs) 1077 { 1078 return bpf_kprobe_multi_entry_ip(current->bpf_ctx); 1079 } 1080 1081 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe_multi = { 1082 .func = bpf_get_func_ip_kprobe_multi, 1083 .gpl_only = false, 1084 .ret_type = RET_INTEGER, 1085 .arg1_type = ARG_PTR_TO_CTX, 1086 }; 1087 BPF_CALL_1(bpf_get_attach_cookie_kprobe_multi,struct pt_regs *,regs)1088 BPF_CALL_1(bpf_get_attach_cookie_kprobe_multi, struct pt_regs *, regs) 1089 { 1090 return bpf_kprobe_multi_cookie(current->bpf_ctx); 1091 } 1092 1093 static const struct bpf_func_proto bpf_get_attach_cookie_proto_kmulti = { 1094 .func = bpf_get_attach_cookie_kprobe_multi, 1095 .gpl_only = false, 1096 .ret_type = RET_INTEGER, 1097 .arg1_type = ARG_PTR_TO_CTX, 1098 }; 1099 BPF_CALL_1(bpf_get_func_ip_uprobe_multi,struct pt_regs *,regs)1100 BPF_CALL_1(bpf_get_func_ip_uprobe_multi, struct pt_regs *, regs) 1101 { 1102 return bpf_uprobe_multi_entry_ip(current->bpf_ctx); 1103 } 1104 1105 static const struct bpf_func_proto bpf_get_func_ip_proto_uprobe_multi = { 1106 .func = bpf_get_func_ip_uprobe_multi, 1107 .gpl_only = false, 1108 .ret_type = RET_INTEGER, 1109 .arg1_type = ARG_PTR_TO_CTX, 1110 }; 1111 BPF_CALL_1(bpf_get_attach_cookie_uprobe_multi,struct pt_regs *,regs)1112 BPF_CALL_1(bpf_get_attach_cookie_uprobe_multi, struct pt_regs *, regs) 1113 { 1114 return bpf_uprobe_multi_cookie(current->bpf_ctx); 1115 } 1116 1117 static const struct bpf_func_proto bpf_get_attach_cookie_proto_umulti = { 1118 .func = bpf_get_attach_cookie_uprobe_multi, 1119 .gpl_only = false, 1120 .ret_type = RET_INTEGER, 1121 .arg1_type = ARG_PTR_TO_CTX, 1122 }; 1123 BPF_CALL_1(bpf_get_attach_cookie_trace,void *,ctx)1124 BPF_CALL_1(bpf_get_attach_cookie_trace, void *, ctx) 1125 { 1126 struct bpf_trace_run_ctx *run_ctx; 1127 1128 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); 1129 return run_ctx->bpf_cookie; 1130 } 1131 1132 static const struct bpf_func_proto bpf_get_attach_cookie_proto_trace = { 1133 .func = bpf_get_attach_cookie_trace, 1134 .gpl_only = false, 1135 .ret_type = RET_INTEGER, 1136 .arg1_type = ARG_PTR_TO_CTX, 1137 }; 1138 BPF_CALL_1(bpf_get_attach_cookie_pe,struct bpf_perf_event_data_kern *,ctx)1139 BPF_CALL_1(bpf_get_attach_cookie_pe, struct bpf_perf_event_data_kern *, ctx) 1140 { 1141 return ctx->event->bpf_cookie; 1142 } 1143 1144 static const struct bpf_func_proto bpf_get_attach_cookie_proto_pe = { 1145 .func = bpf_get_attach_cookie_pe, 1146 .gpl_only = false, 1147 .ret_type = RET_INTEGER, 1148 .arg1_type = ARG_PTR_TO_CTX, 1149 }; 1150 BPF_CALL_1(bpf_get_attach_cookie_tracing,void *,ctx)1151 BPF_CALL_1(bpf_get_attach_cookie_tracing, void *, ctx) 1152 { 1153 struct bpf_trace_run_ctx *run_ctx; 1154 1155 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); 1156 return run_ctx->bpf_cookie; 1157 } 1158 1159 static const struct bpf_func_proto bpf_get_attach_cookie_proto_tracing = { 1160 .func = bpf_get_attach_cookie_tracing, 1161 .gpl_only = false, 1162 .ret_type = RET_INTEGER, 1163 .arg1_type = ARG_PTR_TO_CTX, 1164 }; 1165 BPF_CALL_3(bpf_get_branch_snapshot,void *,buf,u32,size,u64,flags)1166 BPF_CALL_3(bpf_get_branch_snapshot, void *, buf, u32, size, u64, flags) 1167 { 1168 static const u32 br_entry_size = sizeof(struct perf_branch_entry); 1169 u32 entry_cnt = size / br_entry_size; 1170 1171 entry_cnt = static_call(perf_snapshot_branch_stack)(buf, entry_cnt); 1172 1173 if (unlikely(flags)) 1174 return -EINVAL; 1175 1176 if (!entry_cnt) 1177 return -ENOENT; 1178 1179 return entry_cnt * br_entry_size; 1180 } 1181 1182 static const struct bpf_func_proto bpf_get_branch_snapshot_proto = { 1183 .func = bpf_get_branch_snapshot, 1184 .gpl_only = true, 1185 .ret_type = RET_INTEGER, 1186 .arg1_type = ARG_PTR_TO_UNINIT_MEM, 1187 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 1188 }; 1189 BPF_CALL_3(get_func_arg,void *,ctx,u32,n,u64 *,value)1190 BPF_CALL_3(get_func_arg, void *, ctx, u32, n, u64 *, value) 1191 { 1192 /* This helper call is inlined by verifier. */ 1193 u64 nr_args = ((u64 *)ctx)[-1]; 1194 1195 if ((u64) n >= nr_args) 1196 return -EINVAL; 1197 *value = ((u64 *)ctx)[n]; 1198 return 0; 1199 } 1200 1201 static const struct bpf_func_proto bpf_get_func_arg_proto = { 1202 .func = get_func_arg, 1203 .ret_type = RET_INTEGER, 1204 .arg1_type = ARG_PTR_TO_CTX, 1205 .arg2_type = ARG_ANYTHING, 1206 .arg3_type = ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED, 1207 .arg3_size = sizeof(u64), 1208 }; 1209 BPF_CALL_2(get_func_ret,void *,ctx,u64 *,value)1210 BPF_CALL_2(get_func_ret, void *, ctx, u64 *, value) 1211 { 1212 /* This helper call is inlined by verifier. */ 1213 u64 nr_args = ((u64 *)ctx)[-1]; 1214 1215 *value = ((u64 *)ctx)[nr_args]; 1216 return 0; 1217 } 1218 1219 static const struct bpf_func_proto bpf_get_func_ret_proto = { 1220 .func = get_func_ret, 1221 .ret_type = RET_INTEGER, 1222 .arg1_type = ARG_PTR_TO_CTX, 1223 .arg2_type = ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED, 1224 .arg2_size = sizeof(u64), 1225 }; 1226 BPF_CALL_1(get_func_arg_cnt,void *,ctx)1227 BPF_CALL_1(get_func_arg_cnt, void *, ctx) 1228 { 1229 /* This helper call is inlined by verifier. */ 1230 return ((u64 *)ctx)[-1]; 1231 } 1232 1233 static const struct bpf_func_proto bpf_get_func_arg_cnt_proto = { 1234 .func = get_func_arg_cnt, 1235 .ret_type = RET_INTEGER, 1236 .arg1_type = ARG_PTR_TO_CTX, 1237 }; 1238 1239 #ifdef CONFIG_KEYS 1240 __bpf_kfunc_start_defs(); 1241 1242 /** 1243 * bpf_lookup_user_key - lookup a key by its serial 1244 * @serial: key handle serial number 1245 * @flags: lookup-specific flags 1246 * 1247 * Search a key with a given *serial* and the provided *flags*. 1248 * If found, increment the reference count of the key by one, and 1249 * return it in the bpf_key structure. 1250 * 1251 * The bpf_key structure must be passed to bpf_key_put() when done 1252 * with it, so that the key reference count is decremented and the 1253 * bpf_key structure is freed. 1254 * 1255 * Permission checks are deferred to the time the key is used by 1256 * one of the available key-specific kfuncs. 1257 * 1258 * Set *flags* with KEY_LOOKUP_CREATE, to attempt creating a requested 1259 * special keyring (e.g. session keyring), if it doesn't yet exist. 1260 * Set *flags* with KEY_LOOKUP_PARTIAL, to lookup a key without waiting 1261 * for the key construction, and to retrieve uninstantiated keys (keys 1262 * without data attached to them). 1263 * 1264 * Return: a bpf_key pointer with a valid key pointer if the key is found, a 1265 * NULL pointer otherwise. 1266 */ bpf_lookup_user_key(u32 serial,u64 flags)1267 __bpf_kfunc struct bpf_key *bpf_lookup_user_key(u32 serial, u64 flags) 1268 { 1269 key_ref_t key_ref; 1270 struct bpf_key *bkey; 1271 1272 if (flags & ~KEY_LOOKUP_ALL) 1273 return NULL; 1274 1275 /* 1276 * Permission check is deferred until the key is used, as the 1277 * intent of the caller is unknown here. 1278 */ 1279 key_ref = lookup_user_key(serial, flags, KEY_DEFER_PERM_CHECK); 1280 if (IS_ERR(key_ref)) 1281 return NULL; 1282 1283 bkey = kmalloc(sizeof(*bkey), GFP_KERNEL); 1284 if (!bkey) { 1285 key_put(key_ref_to_ptr(key_ref)); 1286 return NULL; 1287 } 1288 1289 bkey->key = key_ref_to_ptr(key_ref); 1290 bkey->has_ref = true; 1291 1292 return bkey; 1293 } 1294 1295 /** 1296 * bpf_lookup_system_key - lookup a key by a system-defined ID 1297 * @id: key ID 1298 * 1299 * Obtain a bpf_key structure with a key pointer set to the passed key ID. 1300 * The key pointer is marked as invalid, to prevent bpf_key_put() from 1301 * attempting to decrement the key reference count on that pointer. The key 1302 * pointer set in such way is currently understood only by 1303 * verify_pkcs7_signature(). 1304 * 1305 * Set *id* to one of the values defined in include/linux/verification.h: 1306 * 0 for the primary keyring (immutable keyring of system keys); 1307 * VERIFY_USE_SECONDARY_KEYRING for both the primary and secondary keyring 1308 * (where keys can be added only if they are vouched for by existing keys 1309 * in those keyrings); VERIFY_USE_PLATFORM_KEYRING for the platform 1310 * keyring (primarily used by the integrity subsystem to verify a kexec'ed 1311 * kerned image and, possibly, the initramfs signature). 1312 * 1313 * Return: a bpf_key pointer with an invalid key pointer set from the 1314 * pre-determined ID on success, a NULL pointer otherwise 1315 */ bpf_lookup_system_key(u64 id)1316 __bpf_kfunc struct bpf_key *bpf_lookup_system_key(u64 id) 1317 { 1318 struct bpf_key *bkey; 1319 1320 if (system_keyring_id_check(id) < 0) 1321 return NULL; 1322 1323 bkey = kmalloc(sizeof(*bkey), GFP_ATOMIC); 1324 if (!bkey) 1325 return NULL; 1326 1327 bkey->key = (struct key *)(unsigned long)id; 1328 bkey->has_ref = false; 1329 1330 return bkey; 1331 } 1332 1333 /** 1334 * bpf_key_put - decrement key reference count if key is valid and free bpf_key 1335 * @bkey: bpf_key structure 1336 * 1337 * Decrement the reference count of the key inside *bkey*, if the pointer 1338 * is valid, and free *bkey*. 1339 */ bpf_key_put(struct bpf_key * bkey)1340 __bpf_kfunc void bpf_key_put(struct bpf_key *bkey) 1341 { 1342 if (bkey->has_ref) 1343 key_put(bkey->key); 1344 1345 kfree(bkey); 1346 } 1347 1348 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION 1349 /** 1350 * bpf_verify_pkcs7_signature - verify a PKCS#7 signature 1351 * @data_p: data to verify 1352 * @sig_p: signature of the data 1353 * @trusted_keyring: keyring with keys trusted for signature verification 1354 * 1355 * Verify the PKCS#7 signature *sig_ptr* against the supplied *data_ptr* 1356 * with keys in a keyring referenced by *trusted_keyring*. 1357 * 1358 * Return: 0 on success, a negative value on error. 1359 */ bpf_verify_pkcs7_signature(struct bpf_dynptr * data_p,struct bpf_dynptr * sig_p,struct bpf_key * trusted_keyring)1360 __bpf_kfunc int bpf_verify_pkcs7_signature(struct bpf_dynptr *data_p, 1361 struct bpf_dynptr *sig_p, 1362 struct bpf_key *trusted_keyring) 1363 { 1364 struct bpf_dynptr_kern *data_ptr = (struct bpf_dynptr_kern *)data_p; 1365 struct bpf_dynptr_kern *sig_ptr = (struct bpf_dynptr_kern *)sig_p; 1366 const void *data, *sig; 1367 u32 data_len, sig_len; 1368 int ret; 1369 1370 if (trusted_keyring->has_ref) { 1371 /* 1372 * Do the permission check deferred in bpf_lookup_user_key(). 1373 * See bpf_lookup_user_key() for more details. 1374 * 1375 * A call to key_task_permission() here would be redundant, as 1376 * it is already done by keyring_search() called by 1377 * find_asymmetric_key(). 1378 */ 1379 ret = key_validate(trusted_keyring->key); 1380 if (ret < 0) 1381 return ret; 1382 } 1383 1384 data_len = __bpf_dynptr_size(data_ptr); 1385 data = __bpf_dynptr_data(data_ptr, data_len); 1386 sig_len = __bpf_dynptr_size(sig_ptr); 1387 sig = __bpf_dynptr_data(sig_ptr, sig_len); 1388 1389 return verify_pkcs7_signature(data, data_len, sig, sig_len, 1390 trusted_keyring->key, 1391 VERIFYING_UNSPECIFIED_SIGNATURE, NULL, 1392 NULL); 1393 } 1394 #endif /* CONFIG_SYSTEM_DATA_VERIFICATION */ 1395 1396 __bpf_kfunc_end_defs(); 1397 1398 BTF_KFUNCS_START(key_sig_kfunc_set) 1399 BTF_ID_FLAGS(func, bpf_lookup_user_key, KF_ACQUIRE | KF_RET_NULL | KF_SLEEPABLE) 1400 BTF_ID_FLAGS(func, bpf_lookup_system_key, KF_ACQUIRE | KF_RET_NULL) 1401 BTF_ID_FLAGS(func, bpf_key_put, KF_RELEASE) 1402 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION 1403 BTF_ID_FLAGS(func, bpf_verify_pkcs7_signature, KF_SLEEPABLE) 1404 #endif 1405 BTF_KFUNCS_END(key_sig_kfunc_set) 1406 1407 static const struct btf_kfunc_id_set bpf_key_sig_kfunc_set = { 1408 .owner = THIS_MODULE, 1409 .set = &key_sig_kfunc_set, 1410 }; 1411 bpf_key_sig_kfuncs_init(void)1412 static int __init bpf_key_sig_kfuncs_init(void) 1413 { 1414 return register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, 1415 &bpf_key_sig_kfunc_set); 1416 } 1417 1418 late_initcall(bpf_key_sig_kfuncs_init); 1419 #endif /* CONFIG_KEYS */ 1420 1421 static const struct bpf_func_proto * bpf_tracing_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1422 bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1423 { 1424 const struct bpf_func_proto *func_proto; 1425 1426 switch (func_id) { 1427 case BPF_FUNC_map_lookup_elem: 1428 return &bpf_map_lookup_elem_proto; 1429 case BPF_FUNC_map_update_elem: 1430 return &bpf_map_update_elem_proto; 1431 case BPF_FUNC_map_delete_elem: 1432 return &bpf_map_delete_elem_proto; 1433 case BPF_FUNC_map_push_elem: 1434 return &bpf_map_push_elem_proto; 1435 case BPF_FUNC_map_pop_elem: 1436 return &bpf_map_pop_elem_proto; 1437 case BPF_FUNC_map_peek_elem: 1438 return &bpf_map_peek_elem_proto; 1439 case BPF_FUNC_map_lookup_percpu_elem: 1440 return &bpf_map_lookup_percpu_elem_proto; 1441 case BPF_FUNC_ktime_get_ns: 1442 return &bpf_ktime_get_ns_proto; 1443 case BPF_FUNC_ktime_get_boot_ns: 1444 return &bpf_ktime_get_boot_ns_proto; 1445 case BPF_FUNC_tail_call: 1446 return &bpf_tail_call_proto; 1447 case BPF_FUNC_get_current_task: 1448 return &bpf_get_current_task_proto; 1449 case BPF_FUNC_get_current_task_btf: 1450 return &bpf_get_current_task_btf_proto; 1451 case BPF_FUNC_task_pt_regs: 1452 return &bpf_task_pt_regs_proto; 1453 case BPF_FUNC_get_current_uid_gid: 1454 return &bpf_get_current_uid_gid_proto; 1455 case BPF_FUNC_get_current_comm: 1456 return &bpf_get_current_comm_proto; 1457 case BPF_FUNC_trace_printk: 1458 return bpf_get_trace_printk_proto(); 1459 case BPF_FUNC_get_smp_processor_id: 1460 return &bpf_get_smp_processor_id_proto; 1461 case BPF_FUNC_get_numa_node_id: 1462 return &bpf_get_numa_node_id_proto; 1463 case BPF_FUNC_perf_event_read: 1464 return &bpf_perf_event_read_proto; 1465 case BPF_FUNC_get_prandom_u32: 1466 return &bpf_get_prandom_u32_proto; 1467 case BPF_FUNC_probe_read_user: 1468 return &bpf_probe_read_user_proto; 1469 case BPF_FUNC_probe_read_kernel: 1470 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1471 NULL : &bpf_probe_read_kernel_proto; 1472 case BPF_FUNC_probe_read_user_str: 1473 return &bpf_probe_read_user_str_proto; 1474 case BPF_FUNC_probe_read_kernel_str: 1475 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1476 NULL : &bpf_probe_read_kernel_str_proto; 1477 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 1478 case BPF_FUNC_probe_read: 1479 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1480 NULL : &bpf_probe_read_compat_proto; 1481 case BPF_FUNC_probe_read_str: 1482 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? 1483 NULL : &bpf_probe_read_compat_str_proto; 1484 #endif 1485 #ifdef CONFIG_CGROUPS 1486 case BPF_FUNC_cgrp_storage_get: 1487 return &bpf_cgrp_storage_get_proto; 1488 case BPF_FUNC_cgrp_storage_delete: 1489 return &bpf_cgrp_storage_delete_proto; 1490 case BPF_FUNC_current_task_under_cgroup: 1491 return &bpf_current_task_under_cgroup_proto; 1492 #endif 1493 case BPF_FUNC_send_signal: 1494 return &bpf_send_signal_proto; 1495 case BPF_FUNC_send_signal_thread: 1496 return &bpf_send_signal_thread_proto; 1497 case BPF_FUNC_perf_event_read_value: 1498 return &bpf_perf_event_read_value_proto; 1499 case BPF_FUNC_ringbuf_output: 1500 return &bpf_ringbuf_output_proto; 1501 case BPF_FUNC_ringbuf_reserve: 1502 return &bpf_ringbuf_reserve_proto; 1503 case BPF_FUNC_ringbuf_submit: 1504 return &bpf_ringbuf_submit_proto; 1505 case BPF_FUNC_ringbuf_discard: 1506 return &bpf_ringbuf_discard_proto; 1507 case BPF_FUNC_ringbuf_query: 1508 return &bpf_ringbuf_query_proto; 1509 case BPF_FUNC_jiffies64: 1510 return &bpf_jiffies64_proto; 1511 case BPF_FUNC_get_task_stack: 1512 return prog->sleepable ? &bpf_get_task_stack_sleepable_proto 1513 : &bpf_get_task_stack_proto; 1514 case BPF_FUNC_copy_from_user: 1515 return &bpf_copy_from_user_proto; 1516 case BPF_FUNC_copy_from_user_task: 1517 return &bpf_copy_from_user_task_proto; 1518 case BPF_FUNC_snprintf_btf: 1519 return &bpf_snprintf_btf_proto; 1520 case BPF_FUNC_per_cpu_ptr: 1521 return &bpf_per_cpu_ptr_proto; 1522 case BPF_FUNC_this_cpu_ptr: 1523 return &bpf_this_cpu_ptr_proto; 1524 case BPF_FUNC_task_storage_get: 1525 if (bpf_prog_check_recur(prog)) 1526 return &bpf_task_storage_get_recur_proto; 1527 return &bpf_task_storage_get_proto; 1528 case BPF_FUNC_task_storage_delete: 1529 if (bpf_prog_check_recur(prog)) 1530 return &bpf_task_storage_delete_recur_proto; 1531 return &bpf_task_storage_delete_proto; 1532 case BPF_FUNC_for_each_map_elem: 1533 return &bpf_for_each_map_elem_proto; 1534 case BPF_FUNC_snprintf: 1535 return &bpf_snprintf_proto; 1536 case BPF_FUNC_get_func_ip: 1537 return &bpf_get_func_ip_proto_tracing; 1538 case BPF_FUNC_get_branch_snapshot: 1539 return &bpf_get_branch_snapshot_proto; 1540 case BPF_FUNC_find_vma: 1541 return &bpf_find_vma_proto; 1542 case BPF_FUNC_trace_vprintk: 1543 return bpf_get_trace_vprintk_proto(); 1544 default: 1545 break; 1546 } 1547 1548 func_proto = bpf_base_func_proto(func_id, prog); 1549 if (func_proto) 1550 return func_proto; 1551 1552 if (!bpf_token_capable(prog->aux->token, CAP_SYS_ADMIN)) 1553 return NULL; 1554 1555 switch (func_id) { 1556 case BPF_FUNC_probe_write_user: 1557 return security_locked_down(LOCKDOWN_BPF_WRITE_USER) < 0 ? 1558 NULL : &bpf_probe_write_user_proto; 1559 default: 1560 return NULL; 1561 } 1562 } 1563 is_kprobe_multi(const struct bpf_prog * prog)1564 static bool is_kprobe_multi(const struct bpf_prog *prog) 1565 { 1566 return prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI || 1567 prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION; 1568 } 1569 is_kprobe_session(const struct bpf_prog * prog)1570 static inline bool is_kprobe_session(const struct bpf_prog *prog) 1571 { 1572 return prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION; 1573 } 1574 is_uprobe_multi(const struct bpf_prog * prog)1575 static inline bool is_uprobe_multi(const struct bpf_prog *prog) 1576 { 1577 return prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI || 1578 prog->expected_attach_type == BPF_TRACE_UPROBE_SESSION; 1579 } 1580 is_uprobe_session(const struct bpf_prog * prog)1581 static inline bool is_uprobe_session(const struct bpf_prog *prog) 1582 { 1583 return prog->expected_attach_type == BPF_TRACE_UPROBE_SESSION; 1584 } 1585 1586 static const struct bpf_func_proto * kprobe_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1587 kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1588 { 1589 switch (func_id) { 1590 case BPF_FUNC_perf_event_output: 1591 return &bpf_perf_event_output_proto; 1592 case BPF_FUNC_get_stackid: 1593 return &bpf_get_stackid_proto; 1594 case BPF_FUNC_get_stack: 1595 return prog->sleepable ? &bpf_get_stack_sleepable_proto : &bpf_get_stack_proto; 1596 #ifdef CONFIG_BPF_KPROBE_OVERRIDE 1597 case BPF_FUNC_override_return: 1598 return &bpf_override_return_proto; 1599 #endif 1600 case BPF_FUNC_get_func_ip: 1601 if (is_kprobe_multi(prog)) 1602 return &bpf_get_func_ip_proto_kprobe_multi; 1603 if (is_uprobe_multi(prog)) 1604 return &bpf_get_func_ip_proto_uprobe_multi; 1605 return &bpf_get_func_ip_proto_kprobe; 1606 case BPF_FUNC_get_attach_cookie: 1607 if (is_kprobe_multi(prog)) 1608 return &bpf_get_attach_cookie_proto_kmulti; 1609 if (is_uprobe_multi(prog)) 1610 return &bpf_get_attach_cookie_proto_umulti; 1611 return &bpf_get_attach_cookie_proto_trace; 1612 default: 1613 return bpf_tracing_func_proto(func_id, prog); 1614 } 1615 } 1616 1617 /* bpf+kprobe programs can access fields of 'struct pt_regs' */ kprobe_prog_is_valid_access(int off,int size,enum bpf_access_type type,const struct bpf_prog * prog,struct bpf_insn_access_aux * info)1618 static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type, 1619 const struct bpf_prog *prog, 1620 struct bpf_insn_access_aux *info) 1621 { 1622 if (off < 0 || off >= sizeof(struct pt_regs)) 1623 return false; 1624 if (type != BPF_READ) 1625 return false; 1626 if (off % size != 0) 1627 return false; 1628 /* 1629 * Assertion for 32 bit to make sure last 8 byte access 1630 * (BPF_DW) to the last 4 byte member is disallowed. 1631 */ 1632 if (off + size > sizeof(struct pt_regs)) 1633 return false; 1634 1635 return true; 1636 } 1637 1638 const struct bpf_verifier_ops kprobe_verifier_ops = { 1639 .get_func_proto = kprobe_prog_func_proto, 1640 .is_valid_access = kprobe_prog_is_valid_access, 1641 }; 1642 1643 const struct bpf_prog_ops kprobe_prog_ops = { 1644 }; 1645 BPF_CALL_5(bpf_perf_event_output_tp,void *,tp_buff,struct bpf_map *,map,u64,flags,void *,data,u64,size)1646 BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map, 1647 u64, flags, void *, data, u64, size) 1648 { 1649 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1650 1651 /* 1652 * r1 points to perf tracepoint buffer where first 8 bytes are hidden 1653 * from bpf program and contain a pointer to 'struct pt_regs'. Fetch it 1654 * from there and call the same bpf_perf_event_output() helper inline. 1655 */ 1656 return ____bpf_perf_event_output(regs, map, flags, data, size); 1657 } 1658 1659 static const struct bpf_func_proto bpf_perf_event_output_proto_tp = { 1660 .func = bpf_perf_event_output_tp, 1661 .gpl_only = true, 1662 .ret_type = RET_INTEGER, 1663 .arg1_type = ARG_PTR_TO_CTX, 1664 .arg2_type = ARG_CONST_MAP_PTR, 1665 .arg3_type = ARG_ANYTHING, 1666 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1667 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 1668 }; 1669 BPF_CALL_3(bpf_get_stackid_tp,void *,tp_buff,struct bpf_map *,map,u64,flags)1670 BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map, 1671 u64, flags) 1672 { 1673 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1674 1675 /* 1676 * Same comment as in bpf_perf_event_output_tp(), only that this time 1677 * the other helper's function body cannot be inlined due to being 1678 * external, thus we need to call raw helper function. 1679 */ 1680 return bpf_get_stackid((unsigned long) regs, (unsigned long) map, 1681 flags, 0, 0); 1682 } 1683 1684 static const struct bpf_func_proto bpf_get_stackid_proto_tp = { 1685 .func = bpf_get_stackid_tp, 1686 .gpl_only = true, 1687 .ret_type = RET_INTEGER, 1688 .arg1_type = ARG_PTR_TO_CTX, 1689 .arg2_type = ARG_CONST_MAP_PTR, 1690 .arg3_type = ARG_ANYTHING, 1691 }; 1692 BPF_CALL_4(bpf_get_stack_tp,void *,tp_buff,void *,buf,u32,size,u64,flags)1693 BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size, 1694 u64, flags) 1695 { 1696 struct pt_regs *regs = *(struct pt_regs **)tp_buff; 1697 1698 return bpf_get_stack((unsigned long) regs, (unsigned long) buf, 1699 (unsigned long) size, flags, 0); 1700 } 1701 1702 static const struct bpf_func_proto bpf_get_stack_proto_tp = { 1703 .func = bpf_get_stack_tp, 1704 .gpl_only = true, 1705 .ret_type = RET_INTEGER, 1706 .arg1_type = ARG_PTR_TO_CTX, 1707 .arg2_type = ARG_PTR_TO_UNINIT_MEM, 1708 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1709 .arg4_type = ARG_ANYTHING, 1710 }; 1711 1712 static const struct bpf_func_proto * tp_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1713 tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1714 { 1715 switch (func_id) { 1716 case BPF_FUNC_perf_event_output: 1717 return &bpf_perf_event_output_proto_tp; 1718 case BPF_FUNC_get_stackid: 1719 return &bpf_get_stackid_proto_tp; 1720 case BPF_FUNC_get_stack: 1721 return &bpf_get_stack_proto_tp; 1722 case BPF_FUNC_get_attach_cookie: 1723 return &bpf_get_attach_cookie_proto_trace; 1724 default: 1725 return bpf_tracing_func_proto(func_id, prog); 1726 } 1727 } 1728 tp_prog_is_valid_access(int off,int size,enum bpf_access_type type,const struct bpf_prog * prog,struct bpf_insn_access_aux * info)1729 static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type, 1730 const struct bpf_prog *prog, 1731 struct bpf_insn_access_aux *info) 1732 { 1733 if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE) 1734 return false; 1735 if (type != BPF_READ) 1736 return false; 1737 if (off % size != 0) 1738 return false; 1739 1740 BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(__u64)); 1741 return true; 1742 } 1743 1744 const struct bpf_verifier_ops tracepoint_verifier_ops = { 1745 .get_func_proto = tp_prog_func_proto, 1746 .is_valid_access = tp_prog_is_valid_access, 1747 }; 1748 1749 const struct bpf_prog_ops tracepoint_prog_ops = { 1750 }; 1751 BPF_CALL_3(bpf_perf_prog_read_value,struct bpf_perf_event_data_kern *,ctx,struct bpf_perf_event_value *,buf,u32,size)1752 BPF_CALL_3(bpf_perf_prog_read_value, struct bpf_perf_event_data_kern *, ctx, 1753 struct bpf_perf_event_value *, buf, u32, size) 1754 { 1755 int err = -EINVAL; 1756 1757 if (unlikely(size != sizeof(struct bpf_perf_event_value))) 1758 goto clear; 1759 err = perf_event_read_local(ctx->event, &buf->counter, &buf->enabled, 1760 &buf->running); 1761 if (unlikely(err)) 1762 goto clear; 1763 return 0; 1764 clear: 1765 memset(buf, 0, size); 1766 return err; 1767 } 1768 1769 static const struct bpf_func_proto bpf_perf_prog_read_value_proto = { 1770 .func = bpf_perf_prog_read_value, 1771 .gpl_only = true, 1772 .ret_type = RET_INTEGER, 1773 .arg1_type = ARG_PTR_TO_CTX, 1774 .arg2_type = ARG_PTR_TO_UNINIT_MEM, 1775 .arg3_type = ARG_CONST_SIZE, 1776 }; 1777 BPF_CALL_4(bpf_read_branch_records,struct bpf_perf_event_data_kern *,ctx,void *,buf,u32,size,u64,flags)1778 BPF_CALL_4(bpf_read_branch_records, struct bpf_perf_event_data_kern *, ctx, 1779 void *, buf, u32, size, u64, flags) 1780 { 1781 static const u32 br_entry_size = sizeof(struct perf_branch_entry); 1782 struct perf_branch_stack *br_stack = ctx->data->br_stack; 1783 u32 to_copy; 1784 1785 if (unlikely(flags & ~BPF_F_GET_BRANCH_RECORDS_SIZE)) 1786 return -EINVAL; 1787 1788 if (unlikely(!(ctx->data->sample_flags & PERF_SAMPLE_BRANCH_STACK))) 1789 return -ENOENT; 1790 1791 if (unlikely(!br_stack)) 1792 return -ENOENT; 1793 1794 if (flags & BPF_F_GET_BRANCH_RECORDS_SIZE) 1795 return br_stack->nr * br_entry_size; 1796 1797 if (!buf || (size % br_entry_size != 0)) 1798 return -EINVAL; 1799 1800 to_copy = min_t(u32, br_stack->nr * br_entry_size, size); 1801 memcpy(buf, br_stack->entries, to_copy); 1802 1803 return to_copy; 1804 } 1805 1806 static const struct bpf_func_proto bpf_read_branch_records_proto = { 1807 .func = bpf_read_branch_records, 1808 .gpl_only = true, 1809 .ret_type = RET_INTEGER, 1810 .arg1_type = ARG_PTR_TO_CTX, 1811 .arg2_type = ARG_PTR_TO_MEM_OR_NULL, 1812 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1813 .arg4_type = ARG_ANYTHING, 1814 }; 1815 1816 static const struct bpf_func_proto * pe_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1817 pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1818 { 1819 switch (func_id) { 1820 case BPF_FUNC_perf_event_output: 1821 return &bpf_perf_event_output_proto_tp; 1822 case BPF_FUNC_get_stackid: 1823 return &bpf_get_stackid_proto_pe; 1824 case BPF_FUNC_get_stack: 1825 return &bpf_get_stack_proto_pe; 1826 case BPF_FUNC_perf_prog_read_value: 1827 return &bpf_perf_prog_read_value_proto; 1828 case BPF_FUNC_read_branch_records: 1829 return &bpf_read_branch_records_proto; 1830 case BPF_FUNC_get_attach_cookie: 1831 return &bpf_get_attach_cookie_proto_pe; 1832 default: 1833 return bpf_tracing_func_proto(func_id, prog); 1834 } 1835 } 1836 1837 /* 1838 * bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp 1839 * to avoid potential recursive reuse issue when/if tracepoints are added 1840 * inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack. 1841 * 1842 * Since raw tracepoints run despite bpf_prog_active, support concurrent usage 1843 * in normal, irq, and nmi context. 1844 */ 1845 struct bpf_raw_tp_regs { 1846 struct pt_regs regs[3]; 1847 }; 1848 static DEFINE_PER_CPU(struct bpf_raw_tp_regs, bpf_raw_tp_regs); 1849 static DEFINE_PER_CPU(int, bpf_raw_tp_nest_level); get_bpf_raw_tp_regs(void)1850 static struct pt_regs *get_bpf_raw_tp_regs(void) 1851 { 1852 struct bpf_raw_tp_regs *tp_regs = this_cpu_ptr(&bpf_raw_tp_regs); 1853 int nest_level = this_cpu_inc_return(bpf_raw_tp_nest_level); 1854 1855 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(tp_regs->regs))) { 1856 this_cpu_dec(bpf_raw_tp_nest_level); 1857 return ERR_PTR(-EBUSY); 1858 } 1859 1860 return &tp_regs->regs[nest_level - 1]; 1861 } 1862 put_bpf_raw_tp_regs(void)1863 static void put_bpf_raw_tp_regs(void) 1864 { 1865 this_cpu_dec(bpf_raw_tp_nest_level); 1866 } 1867 BPF_CALL_5(bpf_perf_event_output_raw_tp,struct bpf_raw_tracepoint_args *,args,struct bpf_map *,map,u64,flags,void *,data,u64,size)1868 BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args, 1869 struct bpf_map *, map, u64, flags, void *, data, u64, size) 1870 { 1871 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1872 int ret; 1873 1874 if (IS_ERR(regs)) 1875 return PTR_ERR(regs); 1876 1877 perf_fetch_caller_regs(regs); 1878 ret = ____bpf_perf_event_output(regs, map, flags, data, size); 1879 1880 put_bpf_raw_tp_regs(); 1881 return ret; 1882 } 1883 1884 static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = { 1885 .func = bpf_perf_event_output_raw_tp, 1886 .gpl_only = true, 1887 .ret_type = RET_INTEGER, 1888 .arg1_type = ARG_PTR_TO_CTX, 1889 .arg2_type = ARG_CONST_MAP_PTR, 1890 .arg3_type = ARG_ANYTHING, 1891 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1892 .arg5_type = ARG_CONST_SIZE_OR_ZERO, 1893 }; 1894 1895 extern const struct bpf_func_proto bpf_skb_output_proto; 1896 extern const struct bpf_func_proto bpf_xdp_output_proto; 1897 extern const struct bpf_func_proto bpf_xdp_get_buff_len_trace_proto; 1898 BPF_CALL_3(bpf_get_stackid_raw_tp,struct bpf_raw_tracepoint_args *,args,struct bpf_map *,map,u64,flags)1899 BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args, 1900 struct bpf_map *, map, u64, flags) 1901 { 1902 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1903 int ret; 1904 1905 if (IS_ERR(regs)) 1906 return PTR_ERR(regs); 1907 1908 perf_fetch_caller_regs(regs); 1909 /* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */ 1910 ret = bpf_get_stackid((unsigned long) regs, (unsigned long) map, 1911 flags, 0, 0); 1912 put_bpf_raw_tp_regs(); 1913 return ret; 1914 } 1915 1916 static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = { 1917 .func = bpf_get_stackid_raw_tp, 1918 .gpl_only = true, 1919 .ret_type = RET_INTEGER, 1920 .arg1_type = ARG_PTR_TO_CTX, 1921 .arg2_type = ARG_CONST_MAP_PTR, 1922 .arg3_type = ARG_ANYTHING, 1923 }; 1924 BPF_CALL_4(bpf_get_stack_raw_tp,struct bpf_raw_tracepoint_args *,args,void *,buf,u32,size,u64,flags)1925 BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args, 1926 void *, buf, u32, size, u64, flags) 1927 { 1928 struct pt_regs *regs = get_bpf_raw_tp_regs(); 1929 int ret; 1930 1931 if (IS_ERR(regs)) 1932 return PTR_ERR(regs); 1933 1934 perf_fetch_caller_regs(regs); 1935 ret = bpf_get_stack((unsigned long) regs, (unsigned long) buf, 1936 (unsigned long) size, flags, 0); 1937 put_bpf_raw_tp_regs(); 1938 return ret; 1939 } 1940 1941 static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = { 1942 .func = bpf_get_stack_raw_tp, 1943 .gpl_only = true, 1944 .ret_type = RET_INTEGER, 1945 .arg1_type = ARG_PTR_TO_CTX, 1946 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 1947 .arg3_type = ARG_CONST_SIZE_OR_ZERO, 1948 .arg4_type = ARG_ANYTHING, 1949 }; 1950 1951 static const struct bpf_func_proto * raw_tp_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1952 raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1953 { 1954 switch (func_id) { 1955 case BPF_FUNC_perf_event_output: 1956 return &bpf_perf_event_output_proto_raw_tp; 1957 case BPF_FUNC_get_stackid: 1958 return &bpf_get_stackid_proto_raw_tp; 1959 case BPF_FUNC_get_stack: 1960 return &bpf_get_stack_proto_raw_tp; 1961 case BPF_FUNC_get_attach_cookie: 1962 return &bpf_get_attach_cookie_proto_tracing; 1963 default: 1964 return bpf_tracing_func_proto(func_id, prog); 1965 } 1966 } 1967 1968 const struct bpf_func_proto * tracing_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1969 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 1970 { 1971 const struct bpf_func_proto *fn; 1972 1973 switch (func_id) { 1974 #ifdef CONFIG_NET 1975 case BPF_FUNC_skb_output: 1976 return &bpf_skb_output_proto; 1977 case BPF_FUNC_xdp_output: 1978 return &bpf_xdp_output_proto; 1979 case BPF_FUNC_skc_to_tcp6_sock: 1980 return &bpf_skc_to_tcp6_sock_proto; 1981 case BPF_FUNC_skc_to_tcp_sock: 1982 return &bpf_skc_to_tcp_sock_proto; 1983 case BPF_FUNC_skc_to_tcp_timewait_sock: 1984 return &bpf_skc_to_tcp_timewait_sock_proto; 1985 case BPF_FUNC_skc_to_tcp_request_sock: 1986 return &bpf_skc_to_tcp_request_sock_proto; 1987 case BPF_FUNC_skc_to_udp6_sock: 1988 return &bpf_skc_to_udp6_sock_proto; 1989 case BPF_FUNC_skc_to_unix_sock: 1990 return &bpf_skc_to_unix_sock_proto; 1991 case BPF_FUNC_skc_to_mptcp_sock: 1992 return &bpf_skc_to_mptcp_sock_proto; 1993 case BPF_FUNC_sk_storage_get: 1994 return &bpf_sk_storage_get_tracing_proto; 1995 case BPF_FUNC_sk_storage_delete: 1996 return &bpf_sk_storage_delete_tracing_proto; 1997 case BPF_FUNC_sock_from_file: 1998 return &bpf_sock_from_file_proto; 1999 case BPF_FUNC_get_socket_cookie: 2000 return &bpf_get_socket_ptr_cookie_proto; 2001 case BPF_FUNC_xdp_get_buff_len: 2002 return &bpf_xdp_get_buff_len_trace_proto; 2003 #endif 2004 case BPF_FUNC_seq_printf: 2005 return prog->expected_attach_type == BPF_TRACE_ITER ? 2006 &bpf_seq_printf_proto : 2007 NULL; 2008 case BPF_FUNC_seq_write: 2009 return prog->expected_attach_type == BPF_TRACE_ITER ? 2010 &bpf_seq_write_proto : 2011 NULL; 2012 case BPF_FUNC_seq_printf_btf: 2013 return prog->expected_attach_type == BPF_TRACE_ITER ? 2014 &bpf_seq_printf_btf_proto : 2015 NULL; 2016 case BPF_FUNC_d_path: 2017 return &bpf_d_path_proto; 2018 case BPF_FUNC_get_func_arg: 2019 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_proto : NULL; 2020 case BPF_FUNC_get_func_ret: 2021 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_ret_proto : NULL; 2022 case BPF_FUNC_get_func_arg_cnt: 2023 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_cnt_proto : NULL; 2024 case BPF_FUNC_get_attach_cookie: 2025 if (prog->type == BPF_PROG_TYPE_TRACING && 2026 prog->expected_attach_type == BPF_TRACE_RAW_TP) 2027 return &bpf_get_attach_cookie_proto_tracing; 2028 return bpf_prog_has_trampoline(prog) ? &bpf_get_attach_cookie_proto_tracing : NULL; 2029 default: 2030 fn = raw_tp_prog_func_proto(func_id, prog); 2031 if (!fn && prog->expected_attach_type == BPF_TRACE_ITER) 2032 fn = bpf_iter_get_func_proto(func_id, prog); 2033 return fn; 2034 } 2035 } 2036 raw_tp_prog_is_valid_access(int off,int size,enum bpf_access_type type,const struct bpf_prog * prog,struct bpf_insn_access_aux * info)2037 static bool raw_tp_prog_is_valid_access(int off, int size, 2038 enum bpf_access_type type, 2039 const struct bpf_prog *prog, 2040 struct bpf_insn_access_aux *info) 2041 { 2042 return bpf_tracing_ctx_access(off, size, type); 2043 } 2044 tracing_prog_is_valid_access(int off,int size,enum bpf_access_type type,const struct bpf_prog * prog,struct bpf_insn_access_aux * info)2045 static bool tracing_prog_is_valid_access(int off, int size, 2046 enum bpf_access_type type, 2047 const struct bpf_prog *prog, 2048 struct bpf_insn_access_aux *info) 2049 { 2050 return bpf_tracing_btf_ctx_access(off, size, type, prog, info); 2051 } 2052 bpf_prog_test_run_tracing(struct bpf_prog * prog,const union bpf_attr * kattr,union bpf_attr __user * uattr)2053 int __weak bpf_prog_test_run_tracing(struct bpf_prog *prog, 2054 const union bpf_attr *kattr, 2055 union bpf_attr __user *uattr) 2056 { 2057 return -ENOTSUPP; 2058 } 2059 2060 const struct bpf_verifier_ops raw_tracepoint_verifier_ops = { 2061 .get_func_proto = raw_tp_prog_func_proto, 2062 .is_valid_access = raw_tp_prog_is_valid_access, 2063 }; 2064 2065 const struct bpf_prog_ops raw_tracepoint_prog_ops = { 2066 #ifdef CONFIG_NET 2067 .test_run = bpf_prog_test_run_raw_tp, 2068 #endif 2069 }; 2070 2071 const struct bpf_verifier_ops tracing_verifier_ops = { 2072 .get_func_proto = tracing_prog_func_proto, 2073 .is_valid_access = tracing_prog_is_valid_access, 2074 }; 2075 2076 const struct bpf_prog_ops tracing_prog_ops = { 2077 .test_run = bpf_prog_test_run_tracing, 2078 }; 2079 raw_tp_writable_prog_is_valid_access(int off,int size,enum bpf_access_type type,const struct bpf_prog * prog,struct bpf_insn_access_aux * info)2080 static bool raw_tp_writable_prog_is_valid_access(int off, int size, 2081 enum bpf_access_type type, 2082 const struct bpf_prog *prog, 2083 struct bpf_insn_access_aux *info) 2084 { 2085 if (off == 0) { 2086 if (size != sizeof(u64) || type != BPF_READ) 2087 return false; 2088 info->reg_type = PTR_TO_TP_BUFFER; 2089 } 2090 return raw_tp_prog_is_valid_access(off, size, type, prog, info); 2091 } 2092 2093 const struct bpf_verifier_ops raw_tracepoint_writable_verifier_ops = { 2094 .get_func_proto = raw_tp_prog_func_proto, 2095 .is_valid_access = raw_tp_writable_prog_is_valid_access, 2096 }; 2097 2098 const struct bpf_prog_ops raw_tracepoint_writable_prog_ops = { 2099 }; 2100 pe_prog_is_valid_access(int off,int size,enum bpf_access_type type,const struct bpf_prog * prog,struct bpf_insn_access_aux * info)2101 static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type, 2102 const struct bpf_prog *prog, 2103 struct bpf_insn_access_aux *info) 2104 { 2105 const int size_u64 = sizeof(u64); 2106 2107 if (off < 0 || off >= sizeof(struct bpf_perf_event_data)) 2108 return false; 2109 if (type != BPF_READ) 2110 return false; 2111 if (off % size != 0) { 2112 if (sizeof(unsigned long) != 4) 2113 return false; 2114 if (size != 8) 2115 return false; 2116 if (off % size != 4) 2117 return false; 2118 } 2119 2120 switch (off) { 2121 case bpf_ctx_range(struct bpf_perf_event_data, sample_period): 2122 bpf_ctx_record_field_size(info, size_u64); 2123 if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) 2124 return false; 2125 break; 2126 case bpf_ctx_range(struct bpf_perf_event_data, addr): 2127 bpf_ctx_record_field_size(info, size_u64); 2128 if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) 2129 return false; 2130 break; 2131 default: 2132 if (size != sizeof(long)) 2133 return false; 2134 } 2135 2136 return true; 2137 } 2138 pe_prog_convert_ctx_access(enum bpf_access_type type,const struct bpf_insn * si,struct bpf_insn * insn_buf,struct bpf_prog * prog,u32 * target_size)2139 static u32 pe_prog_convert_ctx_access(enum bpf_access_type type, 2140 const struct bpf_insn *si, 2141 struct bpf_insn *insn_buf, 2142 struct bpf_prog *prog, u32 *target_size) 2143 { 2144 struct bpf_insn *insn = insn_buf; 2145 2146 switch (si->off) { 2147 case offsetof(struct bpf_perf_event_data, sample_period): 2148 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 2149 data), si->dst_reg, si->src_reg, 2150 offsetof(struct bpf_perf_event_data_kern, data)); 2151 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, 2152 bpf_target_off(struct perf_sample_data, period, 8, 2153 target_size)); 2154 break; 2155 case offsetof(struct bpf_perf_event_data, addr): 2156 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 2157 data), si->dst_reg, si->src_reg, 2158 offsetof(struct bpf_perf_event_data_kern, data)); 2159 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, 2160 bpf_target_off(struct perf_sample_data, addr, 8, 2161 target_size)); 2162 break; 2163 default: 2164 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, 2165 regs), si->dst_reg, si->src_reg, 2166 offsetof(struct bpf_perf_event_data_kern, regs)); 2167 *insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg, 2168 si->off); 2169 break; 2170 } 2171 2172 return insn - insn_buf; 2173 } 2174 2175 const struct bpf_verifier_ops perf_event_verifier_ops = { 2176 .get_func_proto = pe_prog_func_proto, 2177 .is_valid_access = pe_prog_is_valid_access, 2178 .convert_ctx_access = pe_prog_convert_ctx_access, 2179 }; 2180 2181 const struct bpf_prog_ops perf_event_prog_ops = { 2182 }; 2183 2184 static DEFINE_MUTEX(bpf_event_mutex); 2185 2186 #define BPF_TRACE_MAX_PROGS 64 2187 perf_event_attach_bpf_prog(struct perf_event * event,struct bpf_prog * prog,u64 bpf_cookie)2188 int perf_event_attach_bpf_prog(struct perf_event *event, 2189 struct bpf_prog *prog, 2190 u64 bpf_cookie) 2191 { 2192 struct bpf_prog_array *old_array; 2193 struct bpf_prog_array *new_array; 2194 int ret = -EEXIST; 2195 2196 /* 2197 * Kprobe override only works if they are on the function entry, 2198 * and only if they are on the opt-in list. 2199 */ 2200 if (prog->kprobe_override && 2201 (!trace_kprobe_on_func_entry(event->tp_event) || 2202 !trace_kprobe_error_injectable(event->tp_event))) 2203 return -EINVAL; 2204 2205 mutex_lock(&bpf_event_mutex); 2206 2207 if (event->prog) 2208 goto unlock; 2209 2210 old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); 2211 if (old_array && 2212 bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) { 2213 ret = -E2BIG; 2214 goto unlock; 2215 } 2216 2217 ret = bpf_prog_array_copy(old_array, NULL, prog, bpf_cookie, &new_array); 2218 if (ret < 0) 2219 goto unlock; 2220 2221 /* set the new array to event->tp_event and set event->prog */ 2222 event->prog = prog; 2223 event->bpf_cookie = bpf_cookie; 2224 rcu_assign_pointer(event->tp_event->prog_array, new_array); 2225 bpf_prog_array_free_sleepable(old_array); 2226 2227 unlock: 2228 mutex_unlock(&bpf_event_mutex); 2229 return ret; 2230 } 2231 perf_event_detach_bpf_prog(struct perf_event * event)2232 void perf_event_detach_bpf_prog(struct perf_event *event) 2233 { 2234 struct bpf_prog_array *old_array; 2235 struct bpf_prog_array *new_array; 2236 struct bpf_prog *prog = NULL; 2237 int ret; 2238 2239 mutex_lock(&bpf_event_mutex); 2240 2241 if (!event->prog) 2242 goto unlock; 2243 2244 old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); 2245 if (!old_array) 2246 goto put; 2247 2248 ret = bpf_prog_array_copy(old_array, event->prog, NULL, 0, &new_array); 2249 if (ret < 0) { 2250 bpf_prog_array_delete_safe(old_array, event->prog); 2251 } else { 2252 rcu_assign_pointer(event->tp_event->prog_array, new_array); 2253 bpf_prog_array_free_sleepable(old_array); 2254 } 2255 2256 put: 2257 prog = event->prog; 2258 event->prog = NULL; 2259 2260 unlock: 2261 mutex_unlock(&bpf_event_mutex); 2262 2263 if (prog) { 2264 /* 2265 * It could be that the bpf_prog is not sleepable (and will be freed 2266 * via normal RCU), but is called from a point that supports sleepable 2267 * programs and uses tasks-trace-RCU. 2268 */ 2269 synchronize_rcu_tasks_trace(); 2270 2271 bpf_prog_put(prog); 2272 } 2273 } 2274 perf_event_query_prog_array(struct perf_event * event,void __user * info)2275 int perf_event_query_prog_array(struct perf_event *event, void __user *info) 2276 { 2277 struct perf_event_query_bpf __user *uquery = info; 2278 struct perf_event_query_bpf query = {}; 2279 struct bpf_prog_array *progs; 2280 u32 *ids, prog_cnt, ids_len; 2281 int ret; 2282 2283 if (!perfmon_capable()) 2284 return -EPERM; 2285 if (event->attr.type != PERF_TYPE_TRACEPOINT) 2286 return -EINVAL; 2287 if (copy_from_user(&query, uquery, sizeof(query))) 2288 return -EFAULT; 2289 2290 ids_len = query.ids_len; 2291 if (ids_len > BPF_TRACE_MAX_PROGS) 2292 return -E2BIG; 2293 ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN); 2294 if (!ids) 2295 return -ENOMEM; 2296 /* 2297 * The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which 2298 * is required when user only wants to check for uquery->prog_cnt. 2299 * There is no need to check for it since the case is handled 2300 * gracefully in bpf_prog_array_copy_info. 2301 */ 2302 2303 mutex_lock(&bpf_event_mutex); 2304 progs = bpf_event_rcu_dereference(event->tp_event->prog_array); 2305 ret = bpf_prog_array_copy_info(progs, ids, ids_len, &prog_cnt); 2306 mutex_unlock(&bpf_event_mutex); 2307 2308 if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) || 2309 copy_to_user(uquery->ids, ids, ids_len * sizeof(u32))) 2310 ret = -EFAULT; 2311 2312 kfree(ids); 2313 return ret; 2314 } 2315 2316 extern struct bpf_raw_event_map __start__bpf_raw_tp[]; 2317 extern struct bpf_raw_event_map __stop__bpf_raw_tp[]; 2318 bpf_get_raw_tracepoint(const char * name)2319 struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name) 2320 { 2321 struct bpf_raw_event_map *btp = __start__bpf_raw_tp; 2322 2323 for (; btp < __stop__bpf_raw_tp; btp++) { 2324 if (!strcmp(btp->tp->name, name)) 2325 return btp; 2326 } 2327 2328 return bpf_get_raw_tracepoint_module(name); 2329 } 2330 bpf_put_raw_tracepoint(struct bpf_raw_event_map * btp)2331 void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp) 2332 { 2333 struct module *mod; 2334 2335 preempt_disable(); 2336 mod = __module_address((unsigned long)btp); 2337 module_put(mod); 2338 preempt_enable(); 2339 } 2340 2341 static __always_inline __bpf_trace_run(struct bpf_raw_tp_link * link,u64 * args)2342 void __bpf_trace_run(struct bpf_raw_tp_link *link, u64 *args) 2343 { 2344 struct bpf_prog *prog = link->link.prog; 2345 struct bpf_run_ctx *old_run_ctx; 2346 struct bpf_trace_run_ctx run_ctx; 2347 2348 cant_sleep(); 2349 if (unlikely(this_cpu_inc_return(*(prog->active)) != 1)) { 2350 bpf_prog_inc_misses_counter(prog); 2351 goto out; 2352 } 2353 2354 run_ctx.bpf_cookie = link->cookie; 2355 old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx); 2356 2357 rcu_read_lock(); 2358 (void) bpf_prog_run(prog, args); 2359 rcu_read_unlock(); 2360 2361 bpf_reset_run_ctx(old_run_ctx); 2362 out: 2363 this_cpu_dec(*(prog->active)); 2364 } 2365 2366 #define UNPACK(...) __VA_ARGS__ 2367 #define REPEAT_1(FN, DL, X, ...) FN(X) 2368 #define REPEAT_2(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__) 2369 #define REPEAT_3(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_2(FN, DL, __VA_ARGS__) 2370 #define REPEAT_4(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_3(FN, DL, __VA_ARGS__) 2371 #define REPEAT_5(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_4(FN, DL, __VA_ARGS__) 2372 #define REPEAT_6(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_5(FN, DL, __VA_ARGS__) 2373 #define REPEAT_7(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_6(FN, DL, __VA_ARGS__) 2374 #define REPEAT_8(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_7(FN, DL, __VA_ARGS__) 2375 #define REPEAT_9(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_8(FN, DL, __VA_ARGS__) 2376 #define REPEAT_10(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_9(FN, DL, __VA_ARGS__) 2377 #define REPEAT_11(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_10(FN, DL, __VA_ARGS__) 2378 #define REPEAT_12(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_11(FN, DL, __VA_ARGS__) 2379 #define REPEAT(X, FN, DL, ...) REPEAT_##X(FN, DL, __VA_ARGS__) 2380 2381 #define SARG(X) u64 arg##X 2382 #define COPY(X) args[X] = arg##X 2383 2384 #define __DL_COM (,) 2385 #define __DL_SEM (;) 2386 2387 #define __SEQ_0_11 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 2388 2389 #define BPF_TRACE_DEFN_x(x) \ 2390 void bpf_trace_run##x(struct bpf_raw_tp_link *link, \ 2391 REPEAT(x, SARG, __DL_COM, __SEQ_0_11)) \ 2392 { \ 2393 u64 args[x]; \ 2394 REPEAT(x, COPY, __DL_SEM, __SEQ_0_11); \ 2395 __bpf_trace_run(link, args); \ 2396 } \ 2397 EXPORT_SYMBOL_GPL(bpf_trace_run##x) 2398 BPF_TRACE_DEFN_x(1); 2399 BPF_TRACE_DEFN_x(2); 2400 BPF_TRACE_DEFN_x(3); 2401 BPF_TRACE_DEFN_x(4); 2402 BPF_TRACE_DEFN_x(5); 2403 BPF_TRACE_DEFN_x(6); 2404 BPF_TRACE_DEFN_x(7); 2405 BPF_TRACE_DEFN_x(8); 2406 BPF_TRACE_DEFN_x(9); 2407 BPF_TRACE_DEFN_x(10); 2408 BPF_TRACE_DEFN_x(11); 2409 BPF_TRACE_DEFN_x(12); 2410 bpf_probe_register(struct bpf_raw_event_map * btp,struct bpf_raw_tp_link * link)2411 int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_raw_tp_link *link) 2412 { 2413 struct tracepoint *tp = btp->tp; 2414 struct bpf_prog *prog = link->link.prog; 2415 2416 /* 2417 * check that program doesn't access arguments beyond what's 2418 * available in this tracepoint 2419 */ 2420 if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64)) 2421 return -EINVAL; 2422 2423 if (prog->aux->max_tp_access > btp->writable_size) 2424 return -EINVAL; 2425 2426 return tracepoint_probe_register_may_exist(tp, (void *)btp->bpf_func, link); 2427 } 2428 bpf_probe_unregister(struct bpf_raw_event_map * btp,struct bpf_raw_tp_link * link)2429 int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_raw_tp_link *link) 2430 { 2431 return tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, link); 2432 } 2433 bpf_get_perf_event_info(const struct perf_event * event,u32 * prog_id,u32 * fd_type,const char ** buf,u64 * probe_offset,u64 * probe_addr,unsigned long * missed)2434 int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id, 2435 u32 *fd_type, const char **buf, 2436 u64 *probe_offset, u64 *probe_addr, 2437 unsigned long *missed) 2438 { 2439 bool is_tracepoint, is_syscall_tp; 2440 struct bpf_prog *prog; 2441 int flags, err = 0; 2442 2443 prog = event->prog; 2444 if (!prog) 2445 return -ENOENT; 2446 2447 /* not supporting BPF_PROG_TYPE_PERF_EVENT yet */ 2448 if (prog->type == BPF_PROG_TYPE_PERF_EVENT) 2449 return -EOPNOTSUPP; 2450 2451 *prog_id = prog->aux->id; 2452 flags = event->tp_event->flags; 2453 is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT; 2454 is_syscall_tp = is_syscall_trace_event(event->tp_event); 2455 2456 if (is_tracepoint || is_syscall_tp) { 2457 *buf = is_tracepoint ? event->tp_event->tp->name 2458 : event->tp_event->name; 2459 /* We allow NULL pointer for tracepoint */ 2460 if (fd_type) 2461 *fd_type = BPF_FD_TYPE_TRACEPOINT; 2462 if (probe_offset) 2463 *probe_offset = 0x0; 2464 if (probe_addr) 2465 *probe_addr = 0x0; 2466 } else { 2467 /* kprobe/uprobe */ 2468 err = -EOPNOTSUPP; 2469 #ifdef CONFIG_KPROBE_EVENTS 2470 if (flags & TRACE_EVENT_FL_KPROBE) 2471 err = bpf_get_kprobe_info(event, fd_type, buf, 2472 probe_offset, probe_addr, missed, 2473 event->attr.type == PERF_TYPE_TRACEPOINT); 2474 #endif 2475 #ifdef CONFIG_UPROBE_EVENTS 2476 if (flags & TRACE_EVENT_FL_UPROBE) 2477 err = bpf_get_uprobe_info(event, fd_type, buf, 2478 probe_offset, probe_addr, 2479 event->attr.type == PERF_TYPE_TRACEPOINT); 2480 #endif 2481 } 2482 2483 return err; 2484 } 2485 send_signal_irq_work_init(void)2486 static int __init send_signal_irq_work_init(void) 2487 { 2488 int cpu; 2489 struct send_signal_irq_work *work; 2490 2491 for_each_possible_cpu(cpu) { 2492 work = per_cpu_ptr(&send_signal_work, cpu); 2493 init_irq_work(&work->irq_work, do_bpf_send_signal); 2494 } 2495 return 0; 2496 } 2497 2498 subsys_initcall(send_signal_irq_work_init); 2499 2500 #ifdef CONFIG_MODULES bpf_event_notify(struct notifier_block * nb,unsigned long op,void * module)2501 static int bpf_event_notify(struct notifier_block *nb, unsigned long op, 2502 void *module) 2503 { 2504 struct bpf_trace_module *btm, *tmp; 2505 struct module *mod = module; 2506 int ret = 0; 2507 2508 if (mod->num_bpf_raw_events == 0 || 2509 (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING)) 2510 goto out; 2511 2512 mutex_lock(&bpf_module_mutex); 2513 2514 switch (op) { 2515 case MODULE_STATE_COMING: 2516 btm = kzalloc(sizeof(*btm), GFP_KERNEL); 2517 if (btm) { 2518 btm->module = module; 2519 list_add(&btm->list, &bpf_trace_modules); 2520 } else { 2521 ret = -ENOMEM; 2522 } 2523 break; 2524 case MODULE_STATE_GOING: 2525 list_for_each_entry_safe(btm, tmp, &bpf_trace_modules, list) { 2526 if (btm->module == module) { 2527 list_del(&btm->list); 2528 kfree(btm); 2529 break; 2530 } 2531 } 2532 break; 2533 } 2534 2535 mutex_unlock(&bpf_module_mutex); 2536 2537 out: 2538 return notifier_from_errno(ret); 2539 } 2540 2541 static struct notifier_block bpf_module_nb = { 2542 .notifier_call = bpf_event_notify, 2543 }; 2544 bpf_event_init(void)2545 static int __init bpf_event_init(void) 2546 { 2547 register_module_notifier(&bpf_module_nb); 2548 return 0; 2549 } 2550 2551 fs_initcall(bpf_event_init); 2552 #endif /* CONFIG_MODULES */ 2553 2554 struct bpf_session_run_ctx { 2555 struct bpf_run_ctx run_ctx; 2556 bool is_return; 2557 void *data; 2558 }; 2559 2560 #ifdef CONFIG_FPROBE 2561 struct bpf_kprobe_multi_link { 2562 struct bpf_link link; 2563 struct fprobe fp; 2564 unsigned long *addrs; 2565 u64 *cookies; 2566 u32 cnt; 2567 u32 mods_cnt; 2568 struct module **mods; 2569 u32 flags; 2570 }; 2571 2572 struct bpf_kprobe_multi_run_ctx { 2573 struct bpf_session_run_ctx session_ctx; 2574 struct bpf_kprobe_multi_link *link; 2575 unsigned long entry_ip; 2576 }; 2577 2578 struct user_syms { 2579 const char **syms; 2580 char *buf; 2581 }; 2582 2583 #ifndef CONFIG_HAVE_FTRACE_REGS_HAVING_PT_REGS 2584 static DEFINE_PER_CPU(struct pt_regs, bpf_kprobe_multi_pt_regs); 2585 #define bpf_kprobe_multi_pt_regs_ptr() this_cpu_ptr(&bpf_kprobe_multi_pt_regs) 2586 #else 2587 #define bpf_kprobe_multi_pt_regs_ptr() (NULL) 2588 #endif 2589 ftrace_get_entry_ip(unsigned long fentry_ip)2590 static unsigned long ftrace_get_entry_ip(unsigned long fentry_ip) 2591 { 2592 unsigned long ip = ftrace_get_symaddr(fentry_ip); 2593 2594 return ip ? : fentry_ip; 2595 } 2596 copy_user_syms(struct user_syms * us,unsigned long __user * usyms,u32 cnt)2597 static int copy_user_syms(struct user_syms *us, unsigned long __user *usyms, u32 cnt) 2598 { 2599 unsigned long __user usymbol; 2600 const char **syms = NULL; 2601 char *buf = NULL, *p; 2602 int err = -ENOMEM; 2603 unsigned int i; 2604 2605 syms = kvmalloc_array(cnt, sizeof(*syms), GFP_KERNEL); 2606 if (!syms) 2607 goto error; 2608 2609 buf = kvmalloc_array(cnt, KSYM_NAME_LEN, GFP_KERNEL); 2610 if (!buf) 2611 goto error; 2612 2613 for (p = buf, i = 0; i < cnt; i++) { 2614 if (__get_user(usymbol, usyms + i)) { 2615 err = -EFAULT; 2616 goto error; 2617 } 2618 err = strncpy_from_user(p, (const char __user *) usymbol, KSYM_NAME_LEN); 2619 if (err == KSYM_NAME_LEN) 2620 err = -E2BIG; 2621 if (err < 0) 2622 goto error; 2623 syms[i] = p; 2624 p += err + 1; 2625 } 2626 2627 us->syms = syms; 2628 us->buf = buf; 2629 return 0; 2630 2631 error: 2632 if (err) { 2633 kvfree(syms); 2634 kvfree(buf); 2635 } 2636 return err; 2637 } 2638 kprobe_multi_put_modules(struct module ** mods,u32 cnt)2639 static void kprobe_multi_put_modules(struct module **mods, u32 cnt) 2640 { 2641 u32 i; 2642 2643 for (i = 0; i < cnt; i++) 2644 module_put(mods[i]); 2645 } 2646 free_user_syms(struct user_syms * us)2647 static void free_user_syms(struct user_syms *us) 2648 { 2649 kvfree(us->syms); 2650 kvfree(us->buf); 2651 } 2652 bpf_kprobe_multi_link_release(struct bpf_link * link)2653 static void bpf_kprobe_multi_link_release(struct bpf_link *link) 2654 { 2655 struct bpf_kprobe_multi_link *kmulti_link; 2656 2657 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); 2658 unregister_fprobe(&kmulti_link->fp); 2659 kprobe_multi_put_modules(kmulti_link->mods, kmulti_link->mods_cnt); 2660 } 2661 bpf_kprobe_multi_link_dealloc(struct bpf_link * link)2662 static void bpf_kprobe_multi_link_dealloc(struct bpf_link *link) 2663 { 2664 struct bpf_kprobe_multi_link *kmulti_link; 2665 2666 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); 2667 kvfree(kmulti_link->addrs); 2668 kvfree(kmulti_link->cookies); 2669 kfree(kmulti_link->mods); 2670 kfree(kmulti_link); 2671 } 2672 bpf_kprobe_multi_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)2673 static int bpf_kprobe_multi_link_fill_link_info(const struct bpf_link *link, 2674 struct bpf_link_info *info) 2675 { 2676 u64 __user *ucookies = u64_to_user_ptr(info->kprobe_multi.cookies); 2677 u64 __user *uaddrs = u64_to_user_ptr(info->kprobe_multi.addrs); 2678 struct bpf_kprobe_multi_link *kmulti_link; 2679 u32 ucount = info->kprobe_multi.count; 2680 int err = 0, i; 2681 2682 if (!uaddrs ^ !ucount) 2683 return -EINVAL; 2684 if (ucookies && !ucount) 2685 return -EINVAL; 2686 2687 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); 2688 info->kprobe_multi.count = kmulti_link->cnt; 2689 info->kprobe_multi.flags = kmulti_link->flags; 2690 info->kprobe_multi.missed = kmulti_link->fp.nmissed; 2691 2692 if (!uaddrs) 2693 return 0; 2694 if (ucount < kmulti_link->cnt) 2695 err = -ENOSPC; 2696 else 2697 ucount = kmulti_link->cnt; 2698 2699 if (ucookies) { 2700 if (kmulti_link->cookies) { 2701 if (copy_to_user(ucookies, kmulti_link->cookies, ucount * sizeof(u64))) 2702 return -EFAULT; 2703 } else { 2704 for (i = 0; i < ucount; i++) { 2705 if (put_user(0, ucookies + i)) 2706 return -EFAULT; 2707 } 2708 } 2709 } 2710 2711 if (kallsyms_show_value(current_cred())) { 2712 if (copy_to_user(uaddrs, kmulti_link->addrs, ucount * sizeof(u64))) 2713 return -EFAULT; 2714 } else { 2715 for (i = 0; i < ucount; i++) { 2716 if (put_user(0, uaddrs + i)) 2717 return -EFAULT; 2718 } 2719 } 2720 return err; 2721 } 2722 2723 static const struct bpf_link_ops bpf_kprobe_multi_link_lops = { 2724 .release = bpf_kprobe_multi_link_release, 2725 .dealloc_deferred = bpf_kprobe_multi_link_dealloc, 2726 .fill_link_info = bpf_kprobe_multi_link_fill_link_info, 2727 }; 2728 bpf_kprobe_multi_cookie_swap(void * a,void * b,int size,const void * priv)2729 static void bpf_kprobe_multi_cookie_swap(void *a, void *b, int size, const void *priv) 2730 { 2731 const struct bpf_kprobe_multi_link *link = priv; 2732 unsigned long *addr_a = a, *addr_b = b; 2733 u64 *cookie_a, *cookie_b; 2734 2735 cookie_a = link->cookies + (addr_a - link->addrs); 2736 cookie_b = link->cookies + (addr_b - link->addrs); 2737 2738 /* swap addr_a/addr_b and cookie_a/cookie_b values */ 2739 swap(*addr_a, *addr_b); 2740 swap(*cookie_a, *cookie_b); 2741 } 2742 bpf_kprobe_multi_addrs_cmp(const void * a,const void * b)2743 static int bpf_kprobe_multi_addrs_cmp(const void *a, const void *b) 2744 { 2745 const unsigned long *addr_a = a, *addr_b = b; 2746 2747 if (*addr_a == *addr_b) 2748 return 0; 2749 return *addr_a < *addr_b ? -1 : 1; 2750 } 2751 bpf_kprobe_multi_cookie_cmp(const void * a,const void * b,const void * priv)2752 static int bpf_kprobe_multi_cookie_cmp(const void *a, const void *b, const void *priv) 2753 { 2754 return bpf_kprobe_multi_addrs_cmp(a, b); 2755 } 2756 bpf_kprobe_multi_cookie(struct bpf_run_ctx * ctx)2757 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx) 2758 { 2759 struct bpf_kprobe_multi_run_ctx *run_ctx; 2760 struct bpf_kprobe_multi_link *link; 2761 u64 *cookie, entry_ip; 2762 unsigned long *addr; 2763 2764 if (WARN_ON_ONCE(!ctx)) 2765 return 0; 2766 run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, 2767 session_ctx.run_ctx); 2768 link = run_ctx->link; 2769 if (!link->cookies) 2770 return 0; 2771 entry_ip = run_ctx->entry_ip; 2772 addr = bsearch(&entry_ip, link->addrs, link->cnt, sizeof(entry_ip), 2773 bpf_kprobe_multi_addrs_cmp); 2774 if (!addr) 2775 return 0; 2776 cookie = link->cookies + (addr - link->addrs); 2777 return *cookie; 2778 } 2779 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx * ctx)2780 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 2781 { 2782 struct bpf_kprobe_multi_run_ctx *run_ctx; 2783 2784 run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, 2785 session_ctx.run_ctx); 2786 return run_ctx->entry_ip; 2787 } 2788 2789 static int kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link * link,unsigned long entry_ip,struct ftrace_regs * fregs,bool is_return,void * data)2790 kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link, 2791 unsigned long entry_ip, struct ftrace_regs *fregs, 2792 bool is_return, void *data) 2793 { 2794 struct bpf_kprobe_multi_run_ctx run_ctx = { 2795 .session_ctx = { 2796 .is_return = is_return, 2797 .data = data, 2798 }, 2799 .link = link, 2800 .entry_ip = entry_ip, 2801 }; 2802 struct bpf_run_ctx *old_run_ctx; 2803 struct pt_regs *regs; 2804 int err; 2805 2806 if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) { 2807 bpf_prog_inc_misses_counter(link->link.prog); 2808 err = 1; 2809 goto out; 2810 } 2811 2812 migrate_disable(); 2813 rcu_read_lock(); 2814 regs = ftrace_partial_regs(fregs, bpf_kprobe_multi_pt_regs_ptr()); 2815 old_run_ctx = bpf_set_run_ctx(&run_ctx.session_ctx.run_ctx); 2816 err = bpf_prog_run(link->link.prog, regs); 2817 bpf_reset_run_ctx(old_run_ctx); 2818 rcu_read_unlock(); 2819 migrate_enable(); 2820 2821 out: 2822 __this_cpu_dec(bpf_prog_active); 2823 return err; 2824 } 2825 2826 static int kprobe_multi_link_handler(struct fprobe * fp,unsigned long fentry_ip,unsigned long ret_ip,struct ftrace_regs * fregs,void * data)2827 kprobe_multi_link_handler(struct fprobe *fp, unsigned long fentry_ip, 2828 unsigned long ret_ip, struct ftrace_regs *fregs, 2829 void *data) 2830 { 2831 struct bpf_kprobe_multi_link *link; 2832 int err; 2833 2834 link = container_of(fp, struct bpf_kprobe_multi_link, fp); 2835 err = kprobe_multi_link_prog_run(link, ftrace_get_entry_ip(fentry_ip), 2836 fregs, false, data); 2837 return is_kprobe_session(link->link.prog) ? err : 0; 2838 } 2839 2840 static void kprobe_multi_link_exit_handler(struct fprobe * fp,unsigned long fentry_ip,unsigned long ret_ip,struct ftrace_regs * fregs,void * data)2841 kprobe_multi_link_exit_handler(struct fprobe *fp, unsigned long fentry_ip, 2842 unsigned long ret_ip, struct ftrace_regs *fregs, 2843 void *data) 2844 { 2845 struct bpf_kprobe_multi_link *link; 2846 2847 link = container_of(fp, struct bpf_kprobe_multi_link, fp); 2848 kprobe_multi_link_prog_run(link, ftrace_get_entry_ip(fentry_ip), 2849 fregs, true, data); 2850 } 2851 symbols_cmp_r(const void * a,const void * b,const void * priv)2852 static int symbols_cmp_r(const void *a, const void *b, const void *priv) 2853 { 2854 const char **str_a = (const char **) a; 2855 const char **str_b = (const char **) b; 2856 2857 return strcmp(*str_a, *str_b); 2858 } 2859 2860 struct multi_symbols_sort { 2861 const char **funcs; 2862 u64 *cookies; 2863 }; 2864 symbols_swap_r(void * a,void * b,int size,const void * priv)2865 static void symbols_swap_r(void *a, void *b, int size, const void *priv) 2866 { 2867 const struct multi_symbols_sort *data = priv; 2868 const char **name_a = a, **name_b = b; 2869 2870 swap(*name_a, *name_b); 2871 2872 /* If defined, swap also related cookies. */ 2873 if (data->cookies) { 2874 u64 *cookie_a, *cookie_b; 2875 2876 cookie_a = data->cookies + (name_a - data->funcs); 2877 cookie_b = data->cookies + (name_b - data->funcs); 2878 swap(*cookie_a, *cookie_b); 2879 } 2880 } 2881 2882 struct modules_array { 2883 struct module **mods; 2884 int mods_cnt; 2885 int mods_cap; 2886 }; 2887 add_module(struct modules_array * arr,struct module * mod)2888 static int add_module(struct modules_array *arr, struct module *mod) 2889 { 2890 struct module **mods; 2891 2892 if (arr->mods_cnt == arr->mods_cap) { 2893 arr->mods_cap = max(16, arr->mods_cap * 3 / 2); 2894 mods = krealloc_array(arr->mods, arr->mods_cap, sizeof(*mods), GFP_KERNEL); 2895 if (!mods) 2896 return -ENOMEM; 2897 arr->mods = mods; 2898 } 2899 2900 arr->mods[arr->mods_cnt] = mod; 2901 arr->mods_cnt++; 2902 return 0; 2903 } 2904 has_module(struct modules_array * arr,struct module * mod)2905 static bool has_module(struct modules_array *arr, struct module *mod) 2906 { 2907 int i; 2908 2909 for (i = arr->mods_cnt - 1; i >= 0; i--) { 2910 if (arr->mods[i] == mod) 2911 return true; 2912 } 2913 return false; 2914 } 2915 get_modules_for_addrs(struct module *** mods,unsigned long * addrs,u32 addrs_cnt)2916 static int get_modules_for_addrs(struct module ***mods, unsigned long *addrs, u32 addrs_cnt) 2917 { 2918 struct modules_array arr = {}; 2919 u32 i, err = 0; 2920 2921 for (i = 0; i < addrs_cnt; i++) { 2922 struct module *mod; 2923 2924 preempt_disable(); 2925 mod = __module_address(addrs[i]); 2926 /* Either no module or we it's already stored */ 2927 if (!mod || has_module(&arr, mod)) { 2928 preempt_enable(); 2929 continue; 2930 } 2931 if (!try_module_get(mod)) 2932 err = -EINVAL; 2933 preempt_enable(); 2934 if (err) 2935 break; 2936 err = add_module(&arr, mod); 2937 if (err) { 2938 module_put(mod); 2939 break; 2940 } 2941 } 2942 2943 /* We return either err < 0 in case of error, ... */ 2944 if (err) { 2945 kprobe_multi_put_modules(arr.mods, arr.mods_cnt); 2946 kfree(arr.mods); 2947 return err; 2948 } 2949 2950 /* or number of modules found if everything is ok. */ 2951 *mods = arr.mods; 2952 return arr.mods_cnt; 2953 } 2954 addrs_check_error_injection_list(unsigned long * addrs,u32 cnt)2955 static int addrs_check_error_injection_list(unsigned long *addrs, u32 cnt) 2956 { 2957 u32 i; 2958 2959 for (i = 0; i < cnt; i++) { 2960 if (!within_error_injection_list(addrs[i])) 2961 return -EINVAL; 2962 } 2963 return 0; 2964 } 2965 bpf_kprobe_multi_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)2966 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 2967 { 2968 struct bpf_kprobe_multi_link *link = NULL; 2969 struct bpf_link_primer link_primer; 2970 void __user *ucookies; 2971 unsigned long *addrs; 2972 u32 flags, cnt, size; 2973 void __user *uaddrs; 2974 u64 *cookies = NULL; 2975 void __user *usyms; 2976 int err; 2977 2978 /* no support for 32bit archs yet */ 2979 if (sizeof(u64) != sizeof(void *)) 2980 return -EOPNOTSUPP; 2981 2982 if (!is_kprobe_multi(prog)) 2983 return -EINVAL; 2984 2985 flags = attr->link_create.kprobe_multi.flags; 2986 if (flags & ~BPF_F_KPROBE_MULTI_RETURN) 2987 return -EINVAL; 2988 2989 uaddrs = u64_to_user_ptr(attr->link_create.kprobe_multi.addrs); 2990 usyms = u64_to_user_ptr(attr->link_create.kprobe_multi.syms); 2991 if (!!uaddrs == !!usyms) 2992 return -EINVAL; 2993 2994 cnt = attr->link_create.kprobe_multi.cnt; 2995 if (!cnt) 2996 return -EINVAL; 2997 if (cnt > MAX_KPROBE_MULTI_CNT) 2998 return -E2BIG; 2999 3000 size = cnt * sizeof(*addrs); 3001 addrs = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL); 3002 if (!addrs) 3003 return -ENOMEM; 3004 3005 ucookies = u64_to_user_ptr(attr->link_create.kprobe_multi.cookies); 3006 if (ucookies) { 3007 cookies = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL); 3008 if (!cookies) { 3009 err = -ENOMEM; 3010 goto error; 3011 } 3012 if (copy_from_user(cookies, ucookies, size)) { 3013 err = -EFAULT; 3014 goto error; 3015 } 3016 } 3017 3018 if (uaddrs) { 3019 if (copy_from_user(addrs, uaddrs, size)) { 3020 err = -EFAULT; 3021 goto error; 3022 } 3023 } else { 3024 struct multi_symbols_sort data = { 3025 .cookies = cookies, 3026 }; 3027 struct user_syms us; 3028 3029 err = copy_user_syms(&us, usyms, cnt); 3030 if (err) 3031 goto error; 3032 3033 if (cookies) 3034 data.funcs = us.syms; 3035 3036 sort_r(us.syms, cnt, sizeof(*us.syms), symbols_cmp_r, 3037 symbols_swap_r, &data); 3038 3039 err = ftrace_lookup_symbols(us.syms, cnt, addrs); 3040 free_user_syms(&us); 3041 if (err) 3042 goto error; 3043 } 3044 3045 if (prog->kprobe_override && addrs_check_error_injection_list(addrs, cnt)) { 3046 err = -EINVAL; 3047 goto error; 3048 } 3049 3050 link = kzalloc(sizeof(*link), GFP_KERNEL); 3051 if (!link) { 3052 err = -ENOMEM; 3053 goto error; 3054 } 3055 3056 bpf_link_init(&link->link, BPF_LINK_TYPE_KPROBE_MULTI, 3057 &bpf_kprobe_multi_link_lops, prog); 3058 3059 err = bpf_link_prime(&link->link, &link_primer); 3060 if (err) 3061 goto error; 3062 3063 if (!(flags & BPF_F_KPROBE_MULTI_RETURN)) 3064 link->fp.entry_handler = kprobe_multi_link_handler; 3065 if ((flags & BPF_F_KPROBE_MULTI_RETURN) || is_kprobe_session(prog)) 3066 link->fp.exit_handler = kprobe_multi_link_exit_handler; 3067 if (is_kprobe_session(prog)) 3068 link->fp.entry_data_size = sizeof(u64); 3069 3070 link->addrs = addrs; 3071 link->cookies = cookies; 3072 link->cnt = cnt; 3073 link->flags = flags; 3074 3075 if (cookies) { 3076 /* 3077 * Sorting addresses will trigger sorting cookies as well 3078 * (check bpf_kprobe_multi_cookie_swap). This way we can 3079 * find cookie based on the address in bpf_get_attach_cookie 3080 * helper. 3081 */ 3082 sort_r(addrs, cnt, sizeof(*addrs), 3083 bpf_kprobe_multi_cookie_cmp, 3084 bpf_kprobe_multi_cookie_swap, 3085 link); 3086 } 3087 3088 err = get_modules_for_addrs(&link->mods, addrs, cnt); 3089 if (err < 0) { 3090 bpf_link_cleanup(&link_primer); 3091 return err; 3092 } 3093 link->mods_cnt = err; 3094 3095 err = register_fprobe_ips(&link->fp, addrs, cnt); 3096 if (err) { 3097 kprobe_multi_put_modules(link->mods, link->mods_cnt); 3098 bpf_link_cleanup(&link_primer); 3099 return err; 3100 } 3101 3102 return bpf_link_settle(&link_primer); 3103 3104 error: 3105 kfree(link); 3106 kvfree(addrs); 3107 kvfree(cookies); 3108 return err; 3109 } 3110 #else /* !CONFIG_FPROBE */ bpf_kprobe_multi_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)3111 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 3112 { 3113 return -EOPNOTSUPP; 3114 } bpf_kprobe_multi_cookie(struct bpf_run_ctx * ctx)3115 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx) 3116 { 3117 return 0; 3118 } bpf_kprobe_multi_entry_ip(struct bpf_run_ctx * ctx)3119 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 3120 { 3121 return 0; 3122 } 3123 #endif 3124 3125 #ifdef CONFIG_UPROBES 3126 struct bpf_uprobe_multi_link; 3127 3128 struct bpf_uprobe { 3129 struct bpf_uprobe_multi_link *link; 3130 loff_t offset; 3131 unsigned long ref_ctr_offset; 3132 u64 cookie; 3133 struct uprobe *uprobe; 3134 struct uprobe_consumer consumer; 3135 bool session; 3136 }; 3137 3138 struct bpf_uprobe_multi_link { 3139 struct path path; 3140 struct bpf_link link; 3141 u32 cnt; 3142 u32 flags; 3143 struct bpf_uprobe *uprobes; 3144 struct task_struct *task; 3145 }; 3146 3147 struct bpf_uprobe_multi_run_ctx { 3148 struct bpf_session_run_ctx session_ctx; 3149 unsigned long entry_ip; 3150 struct bpf_uprobe *uprobe; 3151 }; 3152 bpf_uprobe_unregister(struct bpf_uprobe * uprobes,u32 cnt)3153 static void bpf_uprobe_unregister(struct bpf_uprobe *uprobes, u32 cnt) 3154 { 3155 u32 i; 3156 3157 for (i = 0; i < cnt; i++) 3158 uprobe_unregister_nosync(uprobes[i].uprobe, &uprobes[i].consumer); 3159 3160 if (cnt) 3161 uprobe_unregister_sync(); 3162 } 3163 bpf_uprobe_multi_link_release(struct bpf_link * link)3164 static void bpf_uprobe_multi_link_release(struct bpf_link *link) 3165 { 3166 struct bpf_uprobe_multi_link *umulti_link; 3167 3168 umulti_link = container_of(link, struct bpf_uprobe_multi_link, link); 3169 bpf_uprobe_unregister(umulti_link->uprobes, umulti_link->cnt); 3170 if (umulti_link->task) 3171 put_task_struct(umulti_link->task); 3172 path_put(&umulti_link->path); 3173 } 3174 bpf_uprobe_multi_link_dealloc(struct bpf_link * link)3175 static void bpf_uprobe_multi_link_dealloc(struct bpf_link *link) 3176 { 3177 struct bpf_uprobe_multi_link *umulti_link; 3178 3179 umulti_link = container_of(link, struct bpf_uprobe_multi_link, link); 3180 kvfree(umulti_link->uprobes); 3181 kfree(umulti_link); 3182 } 3183 bpf_uprobe_multi_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)3184 static int bpf_uprobe_multi_link_fill_link_info(const struct bpf_link *link, 3185 struct bpf_link_info *info) 3186 { 3187 u64 __user *uref_ctr_offsets = u64_to_user_ptr(info->uprobe_multi.ref_ctr_offsets); 3188 u64 __user *ucookies = u64_to_user_ptr(info->uprobe_multi.cookies); 3189 u64 __user *uoffsets = u64_to_user_ptr(info->uprobe_multi.offsets); 3190 u64 __user *upath = u64_to_user_ptr(info->uprobe_multi.path); 3191 u32 upath_size = info->uprobe_multi.path_size; 3192 struct bpf_uprobe_multi_link *umulti_link; 3193 u32 ucount = info->uprobe_multi.count; 3194 int err = 0, i; 3195 char *p, *buf; 3196 long left = 0; 3197 3198 if (!upath ^ !upath_size) 3199 return -EINVAL; 3200 3201 if ((uoffsets || uref_ctr_offsets || ucookies) && !ucount) 3202 return -EINVAL; 3203 3204 umulti_link = container_of(link, struct bpf_uprobe_multi_link, link); 3205 info->uprobe_multi.count = umulti_link->cnt; 3206 info->uprobe_multi.flags = umulti_link->flags; 3207 info->uprobe_multi.pid = umulti_link->task ? 3208 task_pid_nr_ns(umulti_link->task, task_active_pid_ns(current)) : 0; 3209 3210 upath_size = upath_size ? min_t(u32, upath_size, PATH_MAX) : PATH_MAX; 3211 buf = kmalloc(upath_size, GFP_KERNEL); 3212 if (!buf) 3213 return -ENOMEM; 3214 p = d_path(&umulti_link->path, buf, upath_size); 3215 if (IS_ERR(p)) { 3216 kfree(buf); 3217 return PTR_ERR(p); 3218 } 3219 upath_size = buf + upath_size - p; 3220 3221 if (upath) 3222 left = copy_to_user(upath, p, upath_size); 3223 kfree(buf); 3224 if (left) 3225 return -EFAULT; 3226 info->uprobe_multi.path_size = upath_size; 3227 3228 if (!uoffsets && !ucookies && !uref_ctr_offsets) 3229 return 0; 3230 3231 if (ucount < umulti_link->cnt) 3232 err = -ENOSPC; 3233 else 3234 ucount = umulti_link->cnt; 3235 3236 for (i = 0; i < ucount; i++) { 3237 if (uoffsets && 3238 put_user(umulti_link->uprobes[i].offset, uoffsets + i)) 3239 return -EFAULT; 3240 if (uref_ctr_offsets && 3241 put_user(umulti_link->uprobes[i].ref_ctr_offset, uref_ctr_offsets + i)) 3242 return -EFAULT; 3243 if (ucookies && 3244 put_user(umulti_link->uprobes[i].cookie, ucookies + i)) 3245 return -EFAULT; 3246 } 3247 3248 return err; 3249 } 3250 3251 static const struct bpf_link_ops bpf_uprobe_multi_link_lops = { 3252 .release = bpf_uprobe_multi_link_release, 3253 .dealloc_deferred = bpf_uprobe_multi_link_dealloc, 3254 .fill_link_info = bpf_uprobe_multi_link_fill_link_info, 3255 }; 3256 uprobe_prog_run(struct bpf_uprobe * uprobe,unsigned long entry_ip,struct pt_regs * regs,bool is_return,void * data)3257 static int uprobe_prog_run(struct bpf_uprobe *uprobe, 3258 unsigned long entry_ip, 3259 struct pt_regs *regs, 3260 bool is_return, void *data) 3261 { 3262 struct bpf_uprobe_multi_link *link = uprobe->link; 3263 struct bpf_uprobe_multi_run_ctx run_ctx = { 3264 .session_ctx = { 3265 .is_return = is_return, 3266 .data = data, 3267 }, 3268 .entry_ip = entry_ip, 3269 .uprobe = uprobe, 3270 }; 3271 struct bpf_prog *prog = link->link.prog; 3272 bool sleepable = prog->sleepable; 3273 struct bpf_run_ctx *old_run_ctx; 3274 int err; 3275 3276 if (link->task && !same_thread_group(current, link->task)) 3277 return 0; 3278 3279 if (sleepable) 3280 rcu_read_lock_trace(); 3281 else 3282 rcu_read_lock(); 3283 3284 migrate_disable(); 3285 3286 old_run_ctx = bpf_set_run_ctx(&run_ctx.session_ctx.run_ctx); 3287 err = bpf_prog_run(link->link.prog, regs); 3288 bpf_reset_run_ctx(old_run_ctx); 3289 3290 migrate_enable(); 3291 3292 if (sleepable) 3293 rcu_read_unlock_trace(); 3294 else 3295 rcu_read_unlock(); 3296 return err; 3297 } 3298 3299 static bool uprobe_multi_link_filter(struct uprobe_consumer * con,struct mm_struct * mm)3300 uprobe_multi_link_filter(struct uprobe_consumer *con, struct mm_struct *mm) 3301 { 3302 struct bpf_uprobe *uprobe; 3303 3304 uprobe = container_of(con, struct bpf_uprobe, consumer); 3305 return uprobe->link->task->mm == mm; 3306 } 3307 3308 static int uprobe_multi_link_handler(struct uprobe_consumer * con,struct pt_regs * regs,__u64 * data)3309 uprobe_multi_link_handler(struct uprobe_consumer *con, struct pt_regs *regs, 3310 __u64 *data) 3311 { 3312 struct bpf_uprobe *uprobe; 3313 int ret; 3314 3315 uprobe = container_of(con, struct bpf_uprobe, consumer); 3316 ret = uprobe_prog_run(uprobe, instruction_pointer(regs), regs, false, data); 3317 if (uprobe->session) 3318 return ret ? UPROBE_HANDLER_IGNORE : 0; 3319 return 0; 3320 } 3321 3322 static int uprobe_multi_link_ret_handler(struct uprobe_consumer * con,unsigned long func,struct pt_regs * regs,__u64 * data)3323 uprobe_multi_link_ret_handler(struct uprobe_consumer *con, unsigned long func, struct pt_regs *regs, 3324 __u64 *data) 3325 { 3326 struct bpf_uprobe *uprobe; 3327 3328 uprobe = container_of(con, struct bpf_uprobe, consumer); 3329 uprobe_prog_run(uprobe, func, regs, true, data); 3330 return 0; 3331 } 3332 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx * ctx)3333 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 3334 { 3335 struct bpf_uprobe_multi_run_ctx *run_ctx; 3336 3337 run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx, 3338 session_ctx.run_ctx); 3339 return run_ctx->entry_ip; 3340 } 3341 bpf_uprobe_multi_cookie(struct bpf_run_ctx * ctx)3342 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx) 3343 { 3344 struct bpf_uprobe_multi_run_ctx *run_ctx; 3345 3346 run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx, 3347 session_ctx.run_ctx); 3348 return run_ctx->uprobe->cookie; 3349 } 3350 bpf_uprobe_multi_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)3351 int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 3352 { 3353 struct bpf_uprobe_multi_link *link = NULL; 3354 unsigned long __user *uref_ctr_offsets; 3355 struct bpf_link_primer link_primer; 3356 struct bpf_uprobe *uprobes = NULL; 3357 struct task_struct *task = NULL; 3358 unsigned long __user *uoffsets; 3359 u64 __user *ucookies; 3360 void __user *upath; 3361 u32 flags, cnt, i; 3362 struct path path; 3363 char *name; 3364 pid_t pid; 3365 int err; 3366 3367 /* no support for 32bit archs yet */ 3368 if (sizeof(u64) != sizeof(void *)) 3369 return -EOPNOTSUPP; 3370 3371 if (!is_uprobe_multi(prog)) 3372 return -EINVAL; 3373 3374 flags = attr->link_create.uprobe_multi.flags; 3375 if (flags & ~BPF_F_UPROBE_MULTI_RETURN) 3376 return -EINVAL; 3377 3378 /* 3379 * path, offsets and cnt are mandatory, 3380 * ref_ctr_offsets and cookies are optional 3381 */ 3382 upath = u64_to_user_ptr(attr->link_create.uprobe_multi.path); 3383 uoffsets = u64_to_user_ptr(attr->link_create.uprobe_multi.offsets); 3384 cnt = attr->link_create.uprobe_multi.cnt; 3385 pid = attr->link_create.uprobe_multi.pid; 3386 3387 if (!upath || !uoffsets || !cnt || pid < 0) 3388 return -EINVAL; 3389 if (cnt > MAX_UPROBE_MULTI_CNT) 3390 return -E2BIG; 3391 3392 uref_ctr_offsets = u64_to_user_ptr(attr->link_create.uprobe_multi.ref_ctr_offsets); 3393 ucookies = u64_to_user_ptr(attr->link_create.uprobe_multi.cookies); 3394 3395 name = strndup_user(upath, PATH_MAX); 3396 if (IS_ERR(name)) { 3397 err = PTR_ERR(name); 3398 return err; 3399 } 3400 3401 err = kern_path(name, LOOKUP_FOLLOW, &path); 3402 kfree(name); 3403 if (err) 3404 return err; 3405 3406 if (!d_is_reg(path.dentry)) { 3407 err = -EBADF; 3408 goto error_path_put; 3409 } 3410 3411 if (pid) { 3412 task = get_pid_task(find_vpid(pid), PIDTYPE_TGID); 3413 if (!task) { 3414 err = -ESRCH; 3415 goto error_path_put; 3416 } 3417 } 3418 3419 err = -ENOMEM; 3420 3421 link = kzalloc(sizeof(*link), GFP_KERNEL); 3422 uprobes = kvcalloc(cnt, sizeof(*uprobes), GFP_KERNEL); 3423 3424 if (!uprobes || !link) 3425 goto error_free; 3426 3427 for (i = 0; i < cnt; i++) { 3428 if (__get_user(uprobes[i].offset, uoffsets + i)) { 3429 err = -EFAULT; 3430 goto error_free; 3431 } 3432 if (uprobes[i].offset < 0) { 3433 err = -EINVAL; 3434 goto error_free; 3435 } 3436 if (uref_ctr_offsets && __get_user(uprobes[i].ref_ctr_offset, uref_ctr_offsets + i)) { 3437 err = -EFAULT; 3438 goto error_free; 3439 } 3440 if (ucookies && __get_user(uprobes[i].cookie, ucookies + i)) { 3441 err = -EFAULT; 3442 goto error_free; 3443 } 3444 3445 uprobes[i].link = link; 3446 3447 if (!(flags & BPF_F_UPROBE_MULTI_RETURN)) 3448 uprobes[i].consumer.handler = uprobe_multi_link_handler; 3449 if (flags & BPF_F_UPROBE_MULTI_RETURN || is_uprobe_session(prog)) 3450 uprobes[i].consumer.ret_handler = uprobe_multi_link_ret_handler; 3451 if (is_uprobe_session(prog)) 3452 uprobes[i].session = true; 3453 if (pid) 3454 uprobes[i].consumer.filter = uprobe_multi_link_filter; 3455 } 3456 3457 link->cnt = cnt; 3458 link->uprobes = uprobes; 3459 link->path = path; 3460 link->task = task; 3461 link->flags = flags; 3462 3463 bpf_link_init(&link->link, BPF_LINK_TYPE_UPROBE_MULTI, 3464 &bpf_uprobe_multi_link_lops, prog); 3465 3466 for (i = 0; i < cnt; i++) { 3467 uprobes[i].uprobe = uprobe_register(d_real_inode(link->path.dentry), 3468 uprobes[i].offset, 3469 uprobes[i].ref_ctr_offset, 3470 &uprobes[i].consumer); 3471 if (IS_ERR(uprobes[i].uprobe)) { 3472 err = PTR_ERR(uprobes[i].uprobe); 3473 link->cnt = i; 3474 goto error_unregister; 3475 } 3476 } 3477 3478 err = bpf_link_prime(&link->link, &link_primer); 3479 if (err) 3480 goto error_unregister; 3481 3482 return bpf_link_settle(&link_primer); 3483 3484 error_unregister: 3485 bpf_uprobe_unregister(uprobes, link->cnt); 3486 3487 error_free: 3488 kvfree(uprobes); 3489 kfree(link); 3490 if (task) 3491 put_task_struct(task); 3492 error_path_put: 3493 path_put(&path); 3494 return err; 3495 } 3496 #else /* !CONFIG_UPROBES */ bpf_uprobe_multi_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)3497 int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 3498 { 3499 return -EOPNOTSUPP; 3500 } bpf_uprobe_multi_cookie(struct bpf_run_ctx * ctx)3501 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx) 3502 { 3503 return 0; 3504 } bpf_uprobe_multi_entry_ip(struct bpf_run_ctx * ctx)3505 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx) 3506 { 3507 return 0; 3508 } 3509 #endif /* CONFIG_UPROBES */ 3510 3511 __bpf_kfunc_start_defs(); 3512 bpf_session_is_return(void)3513 __bpf_kfunc bool bpf_session_is_return(void) 3514 { 3515 struct bpf_session_run_ctx *session_ctx; 3516 3517 session_ctx = container_of(current->bpf_ctx, struct bpf_session_run_ctx, run_ctx); 3518 return session_ctx->is_return; 3519 } 3520 bpf_session_cookie(void)3521 __bpf_kfunc __u64 *bpf_session_cookie(void) 3522 { 3523 struct bpf_session_run_ctx *session_ctx; 3524 3525 session_ctx = container_of(current->bpf_ctx, struct bpf_session_run_ctx, run_ctx); 3526 return session_ctx->data; 3527 } 3528 3529 __bpf_kfunc_end_defs(); 3530 3531 BTF_KFUNCS_START(kprobe_multi_kfunc_set_ids) BTF_ID_FLAGS(func,bpf_session_is_return)3532 BTF_ID_FLAGS(func, bpf_session_is_return) 3533 BTF_ID_FLAGS(func, bpf_session_cookie) 3534 BTF_KFUNCS_END(kprobe_multi_kfunc_set_ids) 3535 3536 static int bpf_kprobe_multi_filter(const struct bpf_prog *prog, u32 kfunc_id) 3537 { 3538 if (!btf_id_set8_contains(&kprobe_multi_kfunc_set_ids, kfunc_id)) 3539 return 0; 3540 3541 if (!is_kprobe_session(prog) && !is_uprobe_session(prog)) 3542 return -EACCES; 3543 3544 return 0; 3545 } 3546 3547 static const struct btf_kfunc_id_set bpf_kprobe_multi_kfunc_set = { 3548 .owner = THIS_MODULE, 3549 .set = &kprobe_multi_kfunc_set_ids, 3550 .filter = bpf_kprobe_multi_filter, 3551 }; 3552 bpf_kprobe_multi_kfuncs_init(void)3553 static int __init bpf_kprobe_multi_kfuncs_init(void) 3554 { 3555 return register_btf_kfunc_id_set(BPF_PROG_TYPE_KPROBE, &bpf_kprobe_multi_kfunc_set); 3556 } 3557 3558 late_initcall(bpf_kprobe_multi_kfuncs_init); 3559 3560 __bpf_kfunc_start_defs(); 3561 bpf_send_signal_task(struct task_struct * task,int sig,enum pid_type type,u64 value)3562 __bpf_kfunc int bpf_send_signal_task(struct task_struct *task, int sig, enum pid_type type, 3563 u64 value) 3564 { 3565 if (type != PIDTYPE_PID && type != PIDTYPE_TGID) 3566 return -EINVAL; 3567 3568 return bpf_send_signal_common(sig, type, task, value); 3569 } 3570 3571 __bpf_kfunc_end_defs(); 3572