kernel/trace/bpf_trace.c

   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_perf_event.h>
  10 #include <linux/btf.h>
  11 #include <linux/filter.h>
  12 #include <linux/uaccess.h>
  13 #include <linux/ctype.h>
  14 #include <linux/kprobes.h>
  15 #include <linux/spinlock.h>
  16 #include <linux/syscalls.h>
  17 #include <linux/error-injection.h>
  18 #include <linux/btf_ids.h>
  19
  20 #include <uapi/linux/bpf.h>
  21 #include <uapi/linux/btf.h>
  22
  23 #include <asm/tlb.h>
  24
  25 #include "trace_probe.h"
  26 #include "trace.h"
  27
  28 #define CREATE_TRACE_POINTS
  29 #include "bpf_trace.h"
  30
  31 #define bpf_event_rcu_dereference(p)                                    \
  32         rcu_dereference_protected(p, lockdep_is_held(&bpf_event_mutex))
  33
  34 #ifdef CONFIG_MODULES
  35 struct bpf_trace_module {
  36         struct module *module;
  37         struct list_head list;
  38 };
  39
  40 static LIST_HEAD(bpf_trace_modules);
  41 static DEFINE_MUTEX(bpf_module_mutex);
  42
  43 static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name)
  44 {
  45         struct bpf_raw_event_map *btp, *ret = NULL;
  46         struct bpf_trace_module *btm;
  47         unsigned int i;
  48
  49         mutex_lock(&bpf_module_mutex);
  50         list_for_each_entry(btm, &bpf_trace_modules, list) {
  51                 for (i = 0; i < btm->module->num_bpf_raw_events; ++i) {
  52                         btp = &btm->module->bpf_raw_events[i];
  53                         if (!strcmp(btp->tp->name, name)) {
  54                                 if (try_module_get(btm->module))
  55                                         ret = btp;
  56                                 goto out;
  57                         }
  58                 }
  59         }
  60 out:
  61         mutex_unlock(&bpf_module_mutex);
  62         return ret;
  63 }
  64 #else
  65 static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name)
  66 {
  67         return NULL;
  68 }
  69 #endif /* CONFIG_MODULES */
  70
  71 u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
  72 u64 bpf_get_stack(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
  73
  74 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size,
  75                                   u64 flags, const struct btf **btf,
  76                                   s32 *btf_id);
  77
  78 /**
  79  * trace_call_bpf - invoke BPF program
  80  * @call: tracepoint event
  81  * @ctx: opaque context pointer
  82  *
  83  * kprobe handlers execute BPF programs via this helper.
  84  * Can be used from static tracepoints in the future.
  85  *
  86  * Return: BPF programs always return an integer which is interpreted by
  87  * kprobe handler as:
  88  * 0 - return from kprobe (event is filtered out)
  89  * 1 - store kprobe event into ring buffer
  90  * Other values are reserved and currently alias to 1
  91  */
  92 unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx)
  93 {
  94         unsigned int ret;
  95
  96         if (in_nmi()) /* not supported yet */
  97                 return 1;
  98
  99         cant_sleep();
 100
 101         if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) {
 102                 /*
 103                  * since some bpf program is already running on this cpu,
 104                  * don't call into another bpf program (same or different)
 105                  * and don't send kprobe event into ring-buffer,
 106                  * so return zero here
 107                  */
 108                 ret = 0;
 109                 goto out;
 110         }
 111
 112         /*
 113          * Instead of moving rcu_read_lock/rcu_dereference/rcu_read_unlock
 114          * to all call sites, we did a bpf_prog_array_valid() there to check
 115          * whether call->prog_array is empty or not, which is
 116          * a heurisitc to speed up execution.
 117          *
 118          * If bpf_prog_array_valid() fetched prog_array was
 119          * non-NULL, we go into trace_call_bpf() and do the actual
 120          * proper rcu_dereference() under RCU lock.
 121          * If it turns out that prog_array is NULL then, we bail out.
 122          * For the opposite, if the bpf_prog_array_valid() fetched pointer
 123          * was NULL, you'll skip the prog_array with the risk of missing
 124          * out of events when it was updated in between this and the
 125          * rcu_dereference() which is accepted risk.
 126          */
 127         ret = BPF_PROG_RUN_ARRAY_CHECK(call->prog_array, ctx, BPF_PROG_RUN);
 128
 129  out:
 130         __this_cpu_dec(bpf_prog_active);
 131
 132         return ret;
 133 }
 134
 135 #ifdef CONFIG_BPF_KPROBE_OVERRIDE
 136 BPF_CALL_2(bpf_override_return, struct pt_regs *, regs, unsigned long, rc)
 137 {
 138         regs_set_return_value(regs, rc);
 139         override_function_with_return(regs);
 140         return 0;
 141 }
 142
 143 static const struct bpf_func_proto bpf_override_return_proto = {
 144         .func           = bpf_override_return,
 145         .gpl_only       = true,
 146         .ret_type       = RET_INTEGER,
 147         .arg1_type      = ARG_PTR_TO_CTX,
 148         .arg2_type      = ARG_ANYTHING,
 149 };
 150 #endif
 151
 152 static __always_inline int
 153 bpf_probe_read_user_common(void *dst, u32 size, const void __user *unsafe_ptr)
 154 {
 155         int ret;
 156
 157         ret = copy_from_user_nofault(dst, unsafe_ptr, size);
 158         if (unlikely(ret < 0))
 159                 memset(dst, 0, size);
 160         return ret;
 161 }
 162
 163 BPF_CALL_3(bpf_probe_read_user, void *, dst, u32, size,
 164            const void __user *, unsafe_ptr)
 165 {
 166         return bpf_probe_read_user_common(dst, size, unsafe_ptr);
 167 }
 168
 169 const struct bpf_func_proto bpf_probe_read_user_proto = {
 170         .func           = bpf_probe_read_user,
 171         .gpl_only       = true,
 172         .ret_type       = RET_INTEGER,
 173         .arg1_type      = ARG_PTR_TO_UNINIT_MEM,
 174         .arg2_type      = ARG_CONST_SIZE_OR_ZERO,
 175         .arg3_type      = ARG_ANYTHING,
 176 };
 177
 178 static __always_inline int
 179 bpf_probe_read_user_str_common(void *dst, u32 size,
 180                                const void __user *unsafe_ptr)
 181 {
 182         int ret;
 183
 184         /*
 185          * NB: We rely on strncpy_from_user() not copying junk past the NUL
 186          * terminator into `dst`.
 187          *
 188          * strncpy_from_user() does long-sized strides in the fast path. If the
 189          * strncpy does not mask out the bytes after the NUL in `unsafe_ptr`,
 190          * then there could be junk after the NUL in `dst`. If user takes `dst`
 191          * and keys a hash map with it, then semantically identical strings can
 192          * occupy multiple entries in the map.
 193          */
 194         ret = strncpy_from_user_nofault(dst, unsafe_ptr, size);
 195         if (unlikely(ret < 0))
 196                 memset(dst, 0, size);
 197         return ret;
 198 }
 199
 200 BPF_CALL_3(bpf_probe_read_user_str, void *, dst, u32, size,
 201            const void __user *, unsafe_ptr)
 202 {
 203         return bpf_probe_read_user_str_common(dst, size, unsafe_ptr);
 204 }
 205
 206 const struct bpf_func_proto bpf_probe_read_user_str_proto = {
 207         .func           = bpf_probe_read_user_str,
 208         .gpl_only       = true,
 209         .ret_type       = RET_INTEGER,
 210         .arg1_type      = ARG_PTR_TO_UNINIT_MEM,
 211         .arg2_type      = ARG_CONST_SIZE_OR_ZERO,
 212         .arg3_type      = ARG_ANYTHING,
 213 };
 214
 215 static __always_inline int
 216 bpf_probe_read_kernel_common(void *dst, u32 size, const void *unsafe_ptr)
 217 {
 218         int ret = security_locked_down(LOCKDOWN_BPF_READ);
 219
 220         if (unlikely(ret < 0))
 221                 goto fail;
 222         ret = copy_from_kernel_nofault(dst, unsafe_ptr, size);
 223         if (unlikely(ret < 0))
 224                 goto fail;
 225         return ret;
 226 fail:
 227         memset(dst, 0, size);
 228         return ret;
 229 }
 230
 231 BPF_CALL_3(bpf_probe_read_kernel, void *, dst, u32, size,
 232            const void *, unsafe_ptr)
 233 {
 234         return bpf_probe_read_kernel_common(dst, size, unsafe_ptr);
 235 }
 236
 237 const struct bpf_func_proto bpf_probe_read_kernel_proto = {
 238         .func           = bpf_probe_read_kernel,
 239         .gpl_only       = true,
 240         .ret_type       = RET_INTEGER,
 241         .arg1_type      = ARG_PTR_TO_UNINIT_MEM,
 242         .arg2_type      = ARG_CONST_SIZE_OR_ZERO,
 243         .arg3_type      = ARG_ANYTHING,
 244 };
 245
 246 static __always_inline int
 247 bpf_probe_read_kernel_str_common(void *dst, u32 size, const void *unsafe_ptr)
 248 {
 249         int ret = security_locked_down(LOCKDOWN_BPF_READ);
 250
 251         if (unlikely(ret < 0))
 252                 goto fail;
 253
 254         /*
 255          * The strncpy_from_kernel_nofault() call will likely not fill the
 256          * entire buffer, but that's okay in this circumstance as we're probing
 257          * arbitrary memory anyway similar to bpf_probe_read_*() and might
 258          * as well probe the stack. Thus, memory is explicitly cleared
 259          * only in error case, so that improper users ignoring return
 260          * code altogether don't copy garbage; otherwise length of string
 261          * is returned that can be used for bpf_perf_event_output() et al.
 262          */
 263         ret = strncpy_from_kernel_nofault(dst, unsafe_ptr, size);
 264         if (unlikely(ret < 0))
 265                 goto fail;
 266
 267         return ret;
 268 fail:
 269         memset(dst, 0, size);
 270         return ret;
 271 }
 272
 273 BPF_CALL_3(bpf_probe_read_kernel_str, void *, dst, u32, size,
 274            const void *, unsafe_ptr)
 275 {
 276         return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr);
 277 }
 278
 279 const struct bpf_func_proto bpf_probe_read_kernel_str_proto = {
 280         .func           = bpf_probe_read_kernel_str,
 281         .gpl_only       = true,
 282         .ret_type       = RET_INTEGER,
 283         .arg1_type      = ARG_PTR_TO_UNINIT_MEM,
 284         .arg2_type      = ARG_CONST_SIZE_OR_ZERO,
 285         .arg3_type      = ARG_ANYTHING,
 286 };
 287
 288 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
 289 BPF_CALL_3(bpf_probe_read_compat, void *, dst, u32, size,
 290            const void *, unsafe_ptr)
 291 {
 292         if ((unsigned long)unsafe_ptr < TASK_SIZE) {
 293                 return bpf_probe_read_user_common(dst, size,
 294                                 (__force void __user *)unsafe_ptr);
 295         }
 296         return bpf_probe_read_kernel_common(dst, size, unsafe_ptr);
 297 }
 298
 299 static const struct bpf_func_proto bpf_probe_read_compat_proto = {
 300         .func           = bpf_probe_read_compat,
 301         .gpl_only       = true,
 302         .ret_type       = RET_INTEGER,
 303         .arg1_type      = ARG_PTR_TO_UNINIT_MEM,
 304         .arg2_type      = ARG_CONST_SIZE_OR_ZERO,
 305         .arg3_type      = ARG_ANYTHING,
 306 };
 307
 308 BPF_CALL_3(bpf_probe_read_compat_str, void *, dst, u32, size,
 309            const void *, unsafe_ptr)
 310 {
 311         if ((unsigned long)unsafe_ptr < TASK_SIZE) {
 312                 return bpf_probe_read_user_str_common(dst, size,
 313                                 (__force void __user *)unsafe_ptr);
 314         }
 315         return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr);
 316 }
 317
 318 static const struct bpf_func_proto bpf_probe_read_compat_str_proto = {
 319         .func           = bpf_probe_read_compat_str,
 320         .gpl_only       = true,
 321         .ret_type       = RET_INTEGER,
 322         .arg1_type      = ARG_PTR_TO_UNINIT_MEM,
 323         .arg2_type      = ARG_CONST_SIZE_OR_ZERO,
 324         .arg3_type      = ARG_ANYTHING,
 325 };
 326 #endif /* CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE */
 327
 328 BPF_CALL_3(bpf_probe_write_user, void __user *, unsafe_ptr, const void *, src,
 329            u32, size)
 330 {
 331         /*
 332          * Ensure we're in user context which is safe for the helper to
 333          * run. This helper has no business in a kthread.
 334          *
 335          * access_ok() should prevent writing to non-user memory, but in
 336          * some situations (nommu, temporary switch, etc) access_ok() does
 337          * not provide enough validation, hence the check on KERNEL_DS.
 338          *
 339          * nmi_uaccess_okay() ensures the probe is not run in an interim
 340          * state, when the task or mm are switched. This is specifically
 341          * required to prevent the use of temporary mm.
 342          */
 343
 344         if (unlikely(in_interrupt() ||
 345                      current->flags & (PF_KTHREAD | PF_EXITING)))
 346                 return -EPERM;
 347         if (unlikely(uaccess_kernel()))
 348                 return -EPERM;
 349         if (unlikely(!nmi_uaccess_okay()))
 350                 return -EPERM;
 351
 352         return copy_to_user_nofault(unsafe_ptr, src, size);
 353 }
 354
 355 static const struct bpf_func_proto bpf_probe_write_user_proto = {
 356         .func           = bpf_probe_write_user,
 357         .gpl_only       = true,
 358         .ret_type       = RET_INTEGER,
 359         .arg1_type      = ARG_ANYTHING,
 360         .arg2_type      = ARG_PTR_TO_MEM,
 361         .arg3_type      = ARG_CONST_SIZE,
 362 };
 363
 364 static const struct bpf_func_proto *bpf_get_probe_write_proto(void)
 365 {
 366         if (!capable(CAP_SYS_ADMIN))
 367                 return NULL;
 368
 369         pr_warn_ratelimited("%s[%d] is installing a program with bpf_probe_write_user helper that may corrupt user memory!",
 370                             current->comm, task_pid_nr(current));
 371
 372         return &bpf_probe_write_user_proto;
 373 }
 374
 375 static void bpf_trace_copy_string(char *buf, void *unsafe_ptr, char fmt_ptype,
 376                 size_t bufsz)
 377 {
 378         void __user *user_ptr = (__force void __user *)unsafe_ptr;
 379
 380         buf[0] = 0;
 381
 382         switch (fmt_ptype) {
 383         case 's':
 384 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
 385                 if ((unsigned long)unsafe_ptr < TASK_SIZE) {
 386                         strncpy_from_user_nofault(buf, user_ptr, bufsz);
 387                         break;
 388                 }
 389                 fallthrough;
 390 #endif
 391         case 'k':
 392                 strncpy_from_kernel_nofault(buf, unsafe_ptr, bufsz);
 393                 break;
 394         case 'u':
 395                 strncpy_from_user_nofault(buf, user_ptr, bufsz);
 396                 break;
 397         }
 398 }
 399
 400 static DEFINE_RAW_SPINLOCK(trace_printk_lock);
 401
 402 #define BPF_TRACE_PRINTK_SIZE   1024
 403
 404 static __printf(1, 0) int bpf_do_trace_printk(const char *fmt, ...)
 405 {
 406         static char buf[BPF_TRACE_PRINTK_SIZE];
 407         unsigned long flags;
 408         va_list ap;
 409         int ret;
 410
 411         raw_spin_lock_irqsave(&trace_printk_lock, flags);
 412         va_start(ap, fmt);
 413         ret = vsnprintf(buf, sizeof(buf), fmt, ap);
 414         va_end(ap);
 415         /* vsnprintf() will not append null for zero-length strings */
 416         if (ret == 0)
 417                 buf[0] = '\0';
 418         trace_bpf_trace_printk(buf);
 419         raw_spin_unlock_irqrestore(&trace_printk_lock, flags);
 420
 421         return ret;
 422 }
 423
 424 /*
 425  * Only limited trace_printk() conversion specifiers allowed:
 426  * %d %i %u %x %ld %li %lu %lx %lld %lli %llu %llx %p %pB %pks %pus %s
 427  */
 428 BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1,
 429            u64, arg2, u64, arg3)
 430 {
 431         int i, mod[3] = {}, fmt_cnt = 0;
 432         char buf[64], fmt_ptype;
 433         void *unsafe_ptr = NULL;
 434         bool str_seen = false;
 435
 436         /*
 437          * bpf_check()->check_func_arg()->check_stack_boundary()
 438          * guarantees that fmt points to bpf program stack,
 439          * fmt_size bytes of it were initialized and fmt_size > 0
 440          */
 441         if (fmt[--fmt_size] != 0)
 442                 return -EINVAL;
 443
 444         /* check format string for allowed specifiers */
 445         for (i = 0; i < fmt_size; i++) {
 446                 if ((!isprint(fmt[i]) && !isspace(fmt[i])) || !isascii(fmt[i]))
 447                         return -EINVAL;
 448
 449                 if (fmt[i] != '%')
 450                         continue;
 451
 452                 if (fmt_cnt >= 3)
 453                         return -EINVAL;
 454
 455                 /* fmt[i] != 0 && fmt[last] == 0, so we can access fmt[i + 1] */
 456                 i++;
 457                 if (fmt[i] == 'l') {
 458                         mod[fmt_cnt]++;
 459                         i++;
 460                 } else if (fmt[i] == 'p') {
 461                         mod[fmt_cnt]++;
 462                         if ((fmt[i + 1] == 'k' ||
 463                              fmt[i + 1] == 'u') &&
 464                             fmt[i + 2] == 's') {
 465                                 fmt_ptype = fmt[i + 1];
 466                                 i += 2;
 467                                 goto fmt_str;
 468                         }
 469
 470                         if (fmt[i + 1] == 'B') {
 471                                 i++;
 472                                 goto fmt_next;
 473                         }
 474
 475                         /* disallow any further format extensions */
 476                         if (fmt[i + 1] != 0 &&
 477                             !isspace(fmt[i + 1]) &&
 478                             !ispunct(fmt[i + 1]))
 479                                 return -EINVAL;
 480
 481                         goto fmt_next;
 482                 } else if (fmt[i] == 's') {
 483                         mod[fmt_cnt]++;
 484                         fmt_ptype = fmt[i];
 485 fmt_str:
 486                         if (str_seen)
 487                                 /* allow only one '%s' per fmt string */
 488                                 return -EINVAL;
 489                         str_seen = true;
 490
 491                         if (fmt[i + 1] != 0 &&
 492                             !isspace(fmt[i + 1]) &&
 493                             !ispunct(fmt[i + 1]))
 494                                 return -EINVAL;
 495
 496                         switch (fmt_cnt) {
 497                         case 0:
 498                                 unsafe_ptr = (void *)(long)arg1;
 499                                 arg1 = (long)buf;
 500                                 break;
 501                         case 1:
 502                                 unsafe_ptr = (void *)(long)arg2;
 503                                 arg2 = (long)buf;
 504                                 break;
 505                         case 2:
 506                                 unsafe_ptr = (void *)(long)arg3;
 507                                 arg3 = (long)buf;
 508                                 break;
 509                         }
 510
 511                         bpf_trace_copy_string(buf, unsafe_ptr, fmt_ptype,
 512                                         sizeof(buf));
 513                         goto fmt_next;
 514                 }
 515
 516                 if (fmt[i] == 'l') {
 517                         mod[fmt_cnt]++;
 518                         i++;
 519                 }
 520
 521                 if (fmt[i] != 'i' && fmt[i] != 'd' &&
 522                     fmt[i] != 'u' && fmt[i] != 'x')
 523                         return -EINVAL;
 524 fmt_next:
 525                 fmt_cnt++;
 526         }
 527
 528 /* Horrid workaround for getting va_list handling working with different
 529  * argument type combinations generically for 32 and 64 bit archs.
 530  */
 531 #define __BPF_TP_EMIT() __BPF_ARG3_TP()
 532 #define __BPF_TP(...)                                                   \
 533         bpf_do_trace_printk(fmt, ##__VA_ARGS__)
 534
 535 #define __BPF_ARG1_TP(...)                                              \
 536         ((mod[0] == 2 || (mod[0] == 1 && __BITS_PER_LONG == 64))        \
 537           ? __BPF_TP(arg1, ##__VA_ARGS__)                               \
 538           : ((mod[0] == 1 || (mod[0] == 0 && __BITS_PER_LONG == 32))    \
 539               ? __BPF_TP((long)arg1, ##__VA_ARGS__)                     \
 540               : __BPF_TP((u32)arg1, ##__VA_ARGS__)))
 541
 542 #define __BPF_ARG2_TP(...)                                              \
 543         ((mod[1] == 2 || (mod[1] == 1 && __BITS_PER_LONG == 64))        \
 544           ? __BPF_ARG1_TP(arg2, ##__VA_ARGS__)                          \
 545           : ((mod[1] == 1 || (mod[1] == 0 && __BITS_PER_LONG == 32))    \
 546               ? __BPF_ARG1_TP((long)arg2, ##__VA_ARGS__)                \
 547               : __BPF_ARG1_TP((u32)arg2, ##__VA_ARGS__)))
 548
 549 #define __BPF_ARG3_TP(...)                                              \
 550         ((mod[2] == 2 || (mod[2] == 1 && __BITS_PER_LONG == 64))        \
 551           ? __BPF_ARG2_TP(arg3, ##__VA_ARGS__)                          \
 552           : ((mod[2] == 1 || (mod[2] == 0 && __BITS_PER_LONG == 32))    \
 553               ? __BPF_ARG2_TP((long)arg3, ##__VA_ARGS__)                \
 554               : __BPF_ARG2_TP((u32)arg3, ##__VA_ARGS__)))
 555
 556         return __BPF_TP_EMIT();
 557 }
 558
 559 static const struct bpf_func_proto bpf_trace_printk_proto = {
 560         .func           = bpf_trace_printk,
 561         .gpl_only       = true,
 562         .ret_type       = RET_INTEGER,
 563         .arg1_type      = ARG_PTR_TO_MEM,
 564         .arg2_type      = ARG_CONST_SIZE,
 565 };
 566
 567 const struct bpf_func_proto *bpf_get_trace_printk_proto(void)
 568 {
 569         /*
 570          * This program might be calling bpf_trace_printk,
 571          * so enable the associated bpf_trace/bpf_trace_printk event.
 572          * Repeat this each time as it is possible a user has
 573          * disabled bpf_trace_printk events.  By loading a program
 574          * calling bpf_trace_printk() however the user has expressed
 575          * the intent to see such events.
 576          */
 577         if (trace_set_clr_event("bpf_trace", "bpf_trace_printk", 1))
 578                 pr_warn_ratelimited("could not enable bpf_trace_printk events");
 579
 580         return &bpf_trace_printk_proto;
 581 }
 582
 583 #define MAX_SEQ_PRINTF_VARARGS          12
 584 #define MAX_SEQ_PRINTF_MAX_MEMCPY       6
 585 #define MAX_SEQ_PRINTF_STR_LEN          128
 586
 587 struct bpf_seq_printf_buf {
 588         char buf[MAX_SEQ_PRINTF_MAX_MEMCPY][MAX_SEQ_PRINTF_STR_LEN];
 589 };
 590 static DEFINE_PER_CPU(struct bpf_seq_printf_buf, bpf_seq_printf_buf);
 591 static DEFINE_PER_CPU(int, bpf_seq_printf_buf_used);
 592
 593 BPF_CALL_5(bpf_seq_printf, struct seq_file *, m, char *, fmt, u32, fmt_size,
 594            const void *, data, u32, data_len)
 595 {
 596         int err = -EINVAL, fmt_cnt = 0, memcpy_cnt = 0;
 597         int i, buf_used, copy_size, num_args;
 598         u64 params[MAX_SEQ_PRINTF_VARARGS];
 599         struct bpf_seq_printf_buf *bufs;
 600         const u64 *args = data;
 601
 602         buf_used = this_cpu_inc_return(bpf_seq_printf_buf_used);
 603         if (WARN_ON_ONCE(buf_used > 1)) {
 604                 err = -EBUSY;
 605                 goto out;
 606         }
 607
 608         bufs = this_cpu_ptr(&bpf_seq_printf_buf);
 609
 610         /*
 611          * bpf_check()->check_func_arg()->check_stack_boundary()
 612          * guarantees that fmt points to bpf program stack,
 613          * fmt_size bytes of it were initialized and fmt_size > 0
 614          */
 615         if (fmt[--fmt_size] != 0)
 616                 goto out;
 617
 618         if (data_len & 7)
 619                 goto out;
 620
 621         for (i = 0; i < fmt_size; i++) {
 622                 if (fmt[i] == '%') {
 623                         if (fmt[i + 1] == '%')
 624                                 i++;
 625                         else if (!data || !data_len)
 626                                 goto out;
 627                 }
 628         }
 629
 630         num_args = data_len / 8;
 631
 632         /* check format string for allowed specifiers */
 633         for (i = 0; i < fmt_size; i++) {
 634                 /* only printable ascii for now. */
 635                 if ((!isprint(fmt[i]) && !isspace(fmt[i])) || !isascii(fmt[i])) {
 636                         err = -EINVAL;
 637                         goto out;
 638                 }
 639
 640                 if (fmt[i] != '%')
 641                         continue;
 642
 643                 if (fmt[i + 1] == '%') {
 644                         i++;
 645                         continue;
 646                 }
 647
 648                 if (fmt_cnt >= MAX_SEQ_PRINTF_VARARGS) {
 649                         err = -E2BIG;
 650                         goto out;
 651                 }
 652
 653                 if (fmt_cnt >= num_args) {
 654                         err = -EINVAL;
 655                         goto out;
 656                 }
 657
 658                 /* fmt[i] != 0 && fmt[last] == 0, so we can access fmt[i + 1] */
 659                 i++;
 660
 661                 /* skip optional "[0 +-][num]" width formating field */
 662                 while (fmt[i] == '0' || fmt[i] == '+'  || fmt[i] == '-' ||
 663                        fmt[i] == ' ')
 664                         i++;
 665                 if (fmt[i] >= '1' && fmt[i] <= '9') {
 666                         i++;
 667                         while (fmt[i] >= '0' && fmt[i] <= '9')
 668                                 i++;
 669                 }
 670
 671                 if (fmt[i] == 's') {
 672                         void *unsafe_ptr;
 673
 674                         /* try our best to copy */
 675                         if (memcpy_cnt >= MAX_SEQ_PRINTF_MAX_MEMCPY) {
 676                                 err = -E2BIG;
 677                                 goto out;
 678                         }
 679
 680                         unsafe_ptr = (void *)(long)args[fmt_cnt];
 681                         err = strncpy_from_kernel_nofault(bufs->buf[memcpy_cnt],
 682                                         unsafe_ptr, MAX_SEQ_PRINTF_STR_LEN);
 683                         if (err < 0)
 684                                 bufs->buf[memcpy_cnt][0] = '\0';
 685                         params[fmt_cnt] = (u64)(long)bufs->buf[memcpy_cnt];
 686
 687                         fmt_cnt++;
 688                         memcpy_cnt++;
 689                         continue;
 690                 }
 691
 692                 if (fmt[i] == 'p') {
 693                         if (fmt[i + 1] == 0 ||
 694                             fmt[i + 1] == 'K' ||
 695                             fmt[i + 1] == 'x' ||
 696                             fmt[i + 1] == 'B') {
 697                                 /* just kernel pointers */
 698                                 params[fmt_cnt] = args[fmt_cnt];
 699                                 fmt_cnt++;
 700                                 continue;
 701                         }
 702
 703                         /* only support "%pI4", "%pi4", "%pI6" and "%pi6". */
 704                         if (fmt[i + 1] != 'i' && fmt[i + 1] != 'I') {
 705                                 err = -EINVAL;
 706                                 goto out;
 707                         }
 708                         if (fmt[i + 2] != '4' && fmt[i + 2] != '6') {
 709                                 err = -EINVAL;
 710                                 goto out;
 711                         }
 712
 713                         if (memcpy_cnt >= MAX_SEQ_PRINTF_MAX_MEMCPY) {
 714                                 err = -E2BIG;
 715                                 goto out;
 716                         }
 717
 718
 719                         copy_size = (fmt[i + 2] == '4') ? 4 : 16;
 720
 721                         err = copy_from_kernel_nofault(bufs->buf[memcpy_cnt],
 722                                                 (void *) (long) args[fmt_cnt],
 723                                                 copy_size);
 724                         if (err < 0)
 725                                 memset(bufs->buf[memcpy_cnt], 0, copy_size);
 726                         params[fmt_cnt] = (u64)(long)bufs->buf[memcpy_cnt];
 727
 728                         i += 2;
 729                         fmt_cnt++;
 730                         memcpy_cnt++;
 731                         continue;
 732                 }
 733
 734                 if (fmt[i] == 'l') {
 735                         i++;
 736                         if (fmt[i] == 'l')
 737                                 i++;
 738                 }
 739
 740                 if (fmt[i] != 'i' && fmt[i] != 'd' &&
 741                     fmt[i] != 'u' && fmt[i] != 'x' &&
 742                     fmt[i] != 'X') {
 743                         err = -EINVAL;
 744                         goto out;
 745                 }
 746
 747                 params[fmt_cnt] = args[fmt_cnt];
 748                 fmt_cnt++;
 749         }
 750
 751         /* Maximumly we can have MAX_SEQ_PRINTF_VARARGS parameter, just give
 752          * all of them to seq_printf().
 753          */
 754         seq_printf(m, fmt, params[0], params[1], params[2], params[3],
 755                    params[4], params[5], params[6], params[7], params[8],
 756                    params[9], params[10], params[11]);
 757
 758         err = seq_has_overflowed(m) ? -EOVERFLOW : 0;
 759 out:
 760         this_cpu_dec(bpf_seq_printf_buf_used);
 761         return err;
 762 }
 763
 764 BTF_ID_LIST_SINGLE(btf_seq_file_ids, struct, seq_file)
 765
 766 static const struct bpf_func_proto bpf_seq_printf_proto = {
 767         .func           = bpf_seq_printf,
 768         .gpl_only       = true,
 769         .ret_type       = RET_INTEGER,
 770         .arg1_type      = ARG_PTR_TO_BTF_ID,
 771         .arg1_btf_id    = &btf_seq_file_ids[0],
 772         .arg2_type      = ARG_PTR_TO_MEM,
 773         .arg3_type      = ARG_CONST_SIZE,
 774         .arg4_type      = ARG_PTR_TO_MEM_OR_NULL,
 775         .arg5_type      = ARG_CONST_SIZE_OR_ZERO,
 776 };
 777
 778 BPF_CALL_3(bpf_seq_write, struct seq_file *, m, const void *, data, u32, len)
 779 {
 780         return seq_write(m, data, len) ? -EOVERFLOW : 0;
 781 }
 782
 783 static const struct bpf_func_proto bpf_seq_write_proto = {
 784         .func           = bpf_seq_write,
 785         .gpl_only       = true,
 786         .ret_type       = RET_INTEGER,
 787         .arg1_type      = ARG_PTR_TO_BTF_ID,
 788         .arg1_btf_id    = &btf_seq_file_ids[0],
 789         .arg2_type      = ARG_PTR_TO_MEM,
 790         .arg3_type      = ARG_CONST_SIZE_OR_ZERO,
 791 };
 792
 793 BPF_CALL_4(bpf_seq_printf_btf, struct seq_file *, m, struct btf_ptr *, ptr,
 794            u32, btf_ptr_size, u64, flags)
 795 {
 796         const struct btf *btf;
 797         s32 btf_id;
 798         int ret;
 799
 800         ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id);
 801         if (ret)
 802                 return ret;
 803
 804         return btf_type_seq_show_flags(btf, btf_id, ptr->ptr, m, flags);
 805 }
 806
 807 static const struct bpf_func_proto bpf_seq_printf_btf_proto = {
 808         .func           = bpf_seq_printf_btf,
 809         .gpl_only       = true,
 810         .ret_type       = RET_INTEGER,
 811         .arg1_type      = ARG_PTR_TO_BTF_ID,
 812         .arg1_btf_id    = &btf_seq_file_ids[0],
 813         .arg2_type      = ARG_PTR_TO_MEM,
 814         .arg3_type      = ARG_CONST_SIZE_OR_ZERO,
 815         .arg4_type      = ARG_ANYTHING,
 816 };
 817
 818 static __always_inline int
 819 get_map_perf_counter(struct bpf_map *map, u64 flags,
 820                      u64 *value, u64 *enabled, u64 *running)
 821 {
 822         struct bpf_array *array = container_of(map, struct bpf_array, map);
 823         unsigned int cpu = smp_processor_id();
 824         u64 index = flags & BPF_F_INDEX_MASK;
 825         struct bpf_event_entry *ee;
 826
 827         if (unlikely(flags & ~(BPF_F_INDEX_MASK)))
 828                 return -EINVAL;
 829         if (index == BPF_F_CURRENT_CPU)
 830                 index = cpu;
 831         if (unlikely(index >= array->map.max_entries))
 832                 return -E2BIG;
 833
 834         ee = READ_ONCE(array->ptrs[index]);
 835         if (!ee)
 836                 return -ENOENT;
 837
 838         return perf_event_read_local(ee->event, value, enabled, running);
 839 }
 840
 841 BPF_CALL_2(bpf_perf_event_read, struct bpf_map *, map, u64, flags)
 842 {
 843         u64 value = 0;
 844         int err;
 845
 846         err = get_map_perf_counter(map, flags, &value, NULL, NULL);
 847         /*
 848          * this api is ugly since we miss [-22..-2] range of valid
 849          * counter values, but that's uapi
 850          */
 851         if (err)
 852                 return err;
 853         return value;
 854 }
 855
 856 static const struct bpf_func_proto bpf_perf_event_read_proto = {
 857         .func           = bpf_perf_event_read,
 858         .gpl_only       = true,
 859         .ret_type       = RET_INTEGER,
 860         .arg1_type      = ARG_CONST_MAP_PTR,
 861         .arg2_type      = ARG_ANYTHING,
 862 };
 863
 864 BPF_CALL_4(bpf_perf_event_read_value, struct bpf_map *, map, u64, flags,
 865            struct bpf_perf_event_value *, buf, u32, size)
 866 {
 867         int err = -EINVAL;
 868
 869         if (unlikely(size != sizeof(struct bpf_perf_event_value)))
 870                 goto clear;
 871         err = get_map_perf_counter(map, flags, &buf->counter, &buf->enabled,
 872                                    &buf->running);
 873         if (unlikely(err))
 874                 goto clear;
 875         return 0;
 876 clear:
 877         memset(buf, 0, size);
 878         return err;
 879 }
 880
 881 static const struct bpf_func_proto bpf_perf_event_read_value_proto = {
 882         .func           = bpf_perf_event_read_value,
 883         .gpl_only       = true,
 884         .ret_type       = RET_INTEGER,
 885         .arg1_type      = ARG_CONST_MAP_PTR,
 886         .arg2_type      = ARG_ANYTHING,
 887         .arg3_type      = ARG_PTR_TO_UNINIT_MEM,
 888         .arg4_type      = ARG_CONST_SIZE,
 889 };
 890
 891 static __always_inline u64
 892 __bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map,
 893                         u64 flags, struct perf_sample_data *sd)
 894 {
 895         struct bpf_array *array = container_of(map, struct bpf_array, map);
 896         unsigned int cpu = smp_processor_id();
 897         u64 index = flags & BPF_F_INDEX_MASK;
 898         struct bpf_event_entry *ee;
 899         struct perf_event *event;
 900
 901         if (index == BPF_F_CURRENT_CPU)
 902                 index = cpu;
 903         if (unlikely(index >= array->map.max_entries))
 904                 return -E2BIG;
 905
 906         ee = READ_ONCE(array->ptrs[index]);
 907         if (!ee)
 908                 return -ENOENT;
 909
 910         event = ee->event;
 911         if (unlikely(event->attr.type != PERF_TYPE_SOFTWARE ||
 912                      event->attr.config != PERF_COUNT_SW_BPF_OUTPUT))
 913                 return -EINVAL;
 914
 915         if (unlikely(event->oncpu != cpu))
 916                 return -EOPNOTSUPP;
 917
 918         return perf_event_output(event, sd, regs);
 919 }
 920
 921 /*
 922  * Support executing tracepoints in normal, irq, and nmi context that each call
 923  * bpf_perf_event_output
 924  */
 925 struct bpf_trace_sample_data {
 926         struct perf_sample_data sds[3];
 927 };
 928
 929 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_trace_sds);
 930 static DEFINE_PER_CPU(int, bpf_trace_nest_level);
 931 BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map,
 932            u64, flags, void *, data, u64, size)
 933 {
 934         struct bpf_trace_sample_data *sds = this_cpu_ptr(&bpf_trace_sds);
 935         int nest_level = this_cpu_inc_return(bpf_trace_nest_level);
 936         struct perf_raw_record raw = {
 937                 .frag = {
 938                         .size = size,
 939                         .data = data,
 940                 },
 941         };
 942         struct perf_sample_data *sd;
 943         int err;
 944
 945         if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(sds->sds))) {
 946                 err = -EBUSY;
 947                 goto out;
 948         }
 949
 950         sd = &sds->sds[nest_level - 1];
 951
 952         if (unlikely(flags & ~(BPF_F_INDEX_MASK))) {
 953                 err = -EINVAL;
 954                 goto out;
 955         }
 956
 957         perf_sample_data_init(sd, 0, 0);
 958         sd->raw = &raw;
 959
 960         err = __bpf_perf_event_output(regs, map, flags, sd);
 961
 962 out:
 963         this_cpu_dec(bpf_trace_nest_level);
 964         return err;
 965 }
 966
 967 static const struct bpf_func_proto bpf_perf_event_output_proto = {
 968         .func           = bpf_perf_event_output,
 969         .gpl_only       = true,
 970         .ret_type       = RET_INTEGER,
 971         .arg1_type      = ARG_PTR_TO_CTX,
 972         .arg2_type      = ARG_CONST_MAP_PTR,
 973         .arg3_type      = ARG_ANYTHING,
 974         .arg4_type      = ARG_PTR_TO_MEM,
 975         .arg5_type      = ARG_CONST_SIZE_OR_ZERO,
 976 };
 977
 978 static DEFINE_PER_CPU(int, bpf_event_output_nest_level);
 979 struct bpf_nested_pt_regs {
 980         struct pt_regs regs[3];
 981 };
 982 static DEFINE_PER_CPU(struct bpf_nested_pt_regs, bpf_pt_regs);
 983 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_misc_sds);
 984
 985 u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
 986                      void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy)
 987 {
 988         int nest_level = this_cpu_inc_return(bpf_event_output_nest_level);
 989         struct perf_raw_frag frag = {
 990                 .copy           = ctx_copy,
 991                 .size           = ctx_size,
 992                 .data           = ctx,
 993         };
 994         struct perf_raw_record raw = {
 995                 .frag = {
 996                         {
 997                                 .next   = ctx_size ? &frag : NULL,
 998                         },
 999                         .size   = meta_size,
1000                         .data   = meta,
1001                 },
1002         };
1003         struct perf_sample_data *sd;
1004         struct pt_regs *regs;
1005         u64 ret;
1006
1007         if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(bpf_misc_sds.sds))) {
1008                 ret = -EBUSY;
1009                 goto out;
1010         }
1011         sd = this_cpu_ptr(&bpf_misc_sds.sds[nest_level - 1]);
1012         regs = this_cpu_ptr(&bpf_pt_regs.regs[nest_level - 1]);
1013
1014         perf_fetch_caller_regs(regs);
1015         perf_sample_data_init(sd, 0, 0);
1016         sd->raw = &raw;
1017
1018         ret = __bpf_perf_event_output(regs, map, flags, sd);
1019 out:
1020         this_cpu_dec(bpf_event_output_nest_level);
1021         return ret;
1022 }
1023
1024 BPF_CALL_0(bpf_get_current_task)
1025 {
1026         return (long) current;
1027 }
1028
1029 const struct bpf_func_proto bpf_get_current_task_proto = {
1030         .func           = bpf_get_current_task,
1031         .gpl_only       = true,
1032         .ret_type       = RET_INTEGER,
1033 };
1034
1035 BPF_CALL_2(bpf_current_task_under_cgroup, struct bpf_map *, map, u32, idx)
1036 {
1037         struct bpf_array *array = container_of(map, struct bpf_array, map);
1038         struct cgroup *cgrp;
1039
1040         if (unlikely(idx >= array->map.max_entries))
1041                 return -E2BIG;
1042
1043         cgrp = READ_ONCE(array->ptrs[idx]);
1044         if (unlikely(!cgrp))
1045                 return -EAGAIN;
1046
1047         return task_under_cgroup_hierarchy(current, cgrp);
1048 }
1049
1050 static const struct bpf_func_proto bpf_current_task_under_cgroup_proto = {
1051         .func           = bpf_current_task_under_cgroup,
1052         .gpl_only       = false,
1053         .ret_type       = RET_INTEGER,
1054         .arg1_type      = ARG_CONST_MAP_PTR,
1055         .arg2_type      = ARG_ANYTHING,
1056 };
1057
1058 struct send_signal_irq_work {
1059         struct irq_work irq_work;
1060         struct task_struct *task;
1061         u32 sig;
1062         enum pid_type type;
1063 };
1064
1065 static DEFINE_PER_CPU(struct send_signal_irq_work, send_signal_work);
1066
1067 static void do_bpf_send_signal(struct irq_work *entry)
1068 {
1069         struct send_signal_irq_work *work;
1070
1071         work = container_of(entry, struct send_signal_irq_work, irq_work);
1072         group_send_sig_info(work->sig, SEND_SIG_PRIV, work->task, work->type);
1073 }
1074
1075 static int bpf_send_signal_common(u32 sig, enum pid_type type)
1076 {
1077         struct send_signal_irq_work *work = NULL;
1078
1079         /* Similar to bpf_probe_write_user, task needs to be
1080          * in a sound condition and kernel memory access be
1081          * permitted in order to send signal to the current
1082          * task.
1083          */
1084         if (unlikely(current->flags & (PF_KTHREAD | PF_EXITING)))
1085                 return -EPERM;
1086         if (unlikely(uaccess_kernel()))
1087                 return -EPERM;
1088         if (unlikely(!nmi_uaccess_okay()))
1089                 return -EPERM;
1090
1091         if (irqs_disabled()) {
1092                 /* Do an early check on signal validity. Otherwise,
1093                  * the error is lost in deferred irq_work.
1094                  */
1095                 if (unlikely(!valid_signal(sig)))
1096                         return -EINVAL;
1097
1098                 work = this_cpu_ptr(&send_signal_work);
1099                 if (atomic_read(&work->irq_work.flags) & IRQ_WORK_BUSY)
1100                         return -EBUSY;
1101
1102                 /* Add the current task, which is the target of sending signal,
1103                  * to the irq_work. The current task may change when queued
1104                  * irq works get executed.
1105                  */
1106                 work->task = current;
1107                 work->sig = sig;
1108                 work->type = type;
1109                 irq_work_queue(&work->irq_work);
1110                 return 0;
1111         }
1112
1113         return group_send_sig_info(sig, SEND_SIG_PRIV, current, type);
1114 }
1115
1116 BPF_CALL_1(bpf_send_signal, u32, sig)
1117 {
1118         return bpf_send_signal_common(sig, PIDTYPE_TGID);
1119 }
1120
1121 static const struct bpf_func_proto bpf_send_signal_proto = {
1122         .func           = bpf_send_signal,
1123         .gpl_only       = false,
1124         .ret_type       = RET_INTEGER,
1125         .arg1_type      = ARG_ANYTHING,
1126 };
1127
1128 BPF_CALL_1(bpf_send_signal_thread, u32, sig)
1129 {
1130         return bpf_send_signal_common(sig, PIDTYPE_PID);
1131 }
1132
1133 static const struct bpf_func_proto bpf_send_signal_thread_proto = {
1134         .func           = bpf_send_signal_thread,
1135         .gpl_only       = false,
1136         .ret_type       = RET_INTEGER,
1137         .arg1_type      = ARG_ANYTHING,
1138 };
1139
1140 BPF_CALL_3(bpf_d_path, struct path *, path, char *, buf, u32, sz)
1141 {
1142         long len;
1143         char *p;
1144
1145         if (!sz)
1146                 return 0;
1147
1148         p = d_path(path, buf, sz);
1149         if (IS_ERR(p)) {
1150                 len = PTR_ERR(p);
1151         } else {
1152                 len = buf + sz - p;
1153                 memmove(buf, p, len);
1154         }
1155
1156         return len;
1157 }
1158
1159 BTF_SET_START(btf_allowlist_d_path)
1160 #ifdef CONFIG_SECURITY
1161 BTF_ID(func, security_file_permission)
1162 BTF_ID(func, security_inode_getattr)
1163 BTF_ID(func, security_file_open)
1164 #endif
1165 #ifdef CONFIG_SECURITY_PATH
1166 BTF_ID(func, security_path_truncate)
1167 #endif
1168 BTF_ID(func, vfs_truncate)
1169 BTF_ID(func, vfs_fallocate)
1170 BTF_ID(func, dentry_open)
1171 BTF_ID(func, vfs_getattr)
1172 BTF_ID(func, filp_close)
1173 BTF_SET_END(btf_allowlist_d_path)
1174
1175 static bool bpf_d_path_allowed(const struct bpf_prog *prog)
1176 {
1177         return btf_id_set_contains(&btf_allowlist_d_path, prog->aux->attach_btf_id);
1178 }
1179
1180 BTF_ID_LIST_SINGLE(bpf_d_path_btf_ids, struct, path)
1181
1182 static const struct bpf_func_proto bpf_d_path_proto = {
1183         .func           = bpf_d_path,
1184         .gpl_only       = false,
1185         .ret_type       = RET_INTEGER,
1186         .arg1_type      = ARG_PTR_TO_BTF_ID,
1187         .arg1_btf_id    = &bpf_d_path_btf_ids[0],
1188         .arg2_type      = ARG_PTR_TO_MEM,
1189         .arg3_type      = ARG_CONST_SIZE_OR_ZERO,
1190         .allowed        = bpf_d_path_allowed,
1191 };
1192
1193 #define BTF_F_ALL       (BTF_F_COMPACT  | BTF_F_NONAME | \
1194                          BTF_F_PTR_RAW | BTF_F_ZERO)
1195
1196 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size,
1197                                   u64 flags, const struct btf **btf,
1198                                   s32 *btf_id)
1199 {
1200         const struct btf_type *t;
1201
1202         if (unlikely(flags & ~(BTF_F_ALL)))
1203                 return -EINVAL;
1204
1205         if (btf_ptr_size != sizeof(struct btf_ptr))
1206                 return -EINVAL;
1207
1208         *btf = bpf_get_btf_vmlinux();
1209
1210         if (IS_ERR_OR_NULL(*btf))
1211                 return IS_ERR(*btf) ? PTR_ERR(*btf) : -EINVAL;
1212
1213         if (ptr->type_id > 0)
1214                 *btf_id = ptr->type_id;
1215         else
1216                 return -EINVAL;
1217
1218         if (*btf_id > 0)
1219                 t = btf_type_by_id(*btf, *btf_id);
1220         if (*btf_id <= 0 || !t)
1221                 return -ENOENT;
1222
1223         return 0;
1224 }
1225
1226 BPF_CALL_5(bpf_snprintf_btf, char *, str, u32, str_size, struct btf_ptr *, ptr,
1227            u32, btf_ptr_size, u64, flags)
1228 {
1229         const struct btf *btf;
1230         s32 btf_id;
1231         int ret;
1232
1233         ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id);
1234         if (ret)
1235                 return ret;
1236
1237         return btf_type_snprintf_show(btf, btf_id, ptr->ptr, str, str_size,
1238                                       flags);
1239 }
1240
1241 const struct bpf_func_proto bpf_snprintf_btf_proto = {
1242         .func           = bpf_snprintf_btf,
1243         .gpl_only       = false,
1244         .ret_type       = RET_INTEGER,
1245         .arg1_type      = ARG_PTR_TO_MEM,
1246         .arg2_type      = ARG_CONST_SIZE,
1247         .arg3_type      = ARG_PTR_TO_MEM,
1248         .arg4_type      = ARG_CONST_SIZE,
1249         .arg5_type      = ARG_ANYTHING,
1250 };
1251
1252 const struct bpf_func_proto *
1253 bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1254 {
1255         switch (func_id) {
1256         case BPF_FUNC_map_lookup_elem:
1257                 return &bpf_map_lookup_elem_proto;
1258         case BPF_FUNC_map_update_elem:
1259                 return &bpf_map_update_elem_proto;
1260         case BPF_FUNC_map_delete_elem:
1261                 return &bpf_map_delete_elem_proto;
1262         case BPF_FUNC_map_push_elem:
1263                 return &bpf_map_push_elem_proto;
1264         case BPF_FUNC_map_pop_elem:
1265                 return &bpf_map_pop_elem_proto;
1266         case BPF_FUNC_map_peek_elem:
1267                 return &bpf_map_peek_elem_proto;
1268         case BPF_FUNC_ktime_get_ns:
1269                 return &bpf_ktime_get_ns_proto;
1270         case BPF_FUNC_ktime_get_boot_ns:
1271                 return &bpf_ktime_get_boot_ns_proto;
1272         case BPF_FUNC_tail_call:
1273                 return &bpf_tail_call_proto;
1274         case BPF_FUNC_get_current_pid_tgid:
1275                 return &bpf_get_current_pid_tgid_proto;
1276         case BPF_FUNC_get_current_task:
1277                 return &bpf_get_current_task_proto;
1278         case BPF_FUNC_get_current_uid_gid:
1279                 return &bpf_get_current_uid_gid_proto;
1280         case BPF_FUNC_get_current_comm:
1281                 return &bpf_get_current_comm_proto;
1282         case BPF_FUNC_trace_printk:
1283                 return bpf_get_trace_printk_proto();
1284         case BPF_FUNC_get_smp_processor_id:
1285                 return &bpf_get_smp_processor_id_proto;
1286         case BPF_FUNC_get_numa_node_id:
1287                 return &bpf_get_numa_node_id_proto;
1288         case BPF_FUNC_perf_event_read:
1289                 return &bpf_perf_event_read_proto;
1290         case BPF_FUNC_probe_write_user:
1291                 return bpf_get_probe_write_proto();
1292         case BPF_FUNC_current_task_under_cgroup:
1293                 return &bpf_current_task_under_cgroup_proto;
1294         case BPF_FUNC_get_prandom_u32:
1295                 return &bpf_get_prandom_u32_proto;
1296         case BPF_FUNC_probe_read_user:
1297                 return &bpf_probe_read_user_proto;
1298         case BPF_FUNC_probe_read_kernel:
1299                 return &bpf_probe_read_kernel_proto;
1300         case BPF_FUNC_probe_read_user_str:
1301                 return &bpf_probe_read_user_str_proto;
1302         case BPF_FUNC_probe_read_kernel_str:
1303                 return &bpf_probe_read_kernel_str_proto;
1304 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
1305         case BPF_FUNC_probe_read:
1306                 return &bpf_probe_read_compat_proto;
1307         case BPF_FUNC_probe_read_str:
1308                 return &bpf_probe_read_compat_str_proto;
1309 #endif
1310 #ifdef CONFIG_CGROUPS
1311         case BPF_FUNC_get_current_cgroup_id:
1312                 return &bpf_get_current_cgroup_id_proto;
1313 #endif
1314         case BPF_FUNC_send_signal:
1315                 return &bpf_send_signal_proto;
1316         case BPF_FUNC_send_signal_thread:
1317                 return &bpf_send_signal_thread_proto;
1318         case BPF_FUNC_perf_event_read_value:
1319                 return &bpf_perf_event_read_value_proto;
1320         case BPF_FUNC_get_ns_current_pid_tgid:
1321                 return &bpf_get_ns_current_pid_tgid_proto;
1322         case BPF_FUNC_ringbuf_output:
1323                 return &bpf_ringbuf_output_proto;
1324         case BPF_FUNC_ringbuf_reserve:
1325                 return &bpf_ringbuf_reserve_proto;
1326         case BPF_FUNC_ringbuf_submit:
1327                 return &bpf_ringbuf_submit_proto;
1328         case BPF_FUNC_ringbuf_discard:
1329                 return &bpf_ringbuf_discard_proto;
1330         case BPF_FUNC_ringbuf_query:
1331                 return &bpf_ringbuf_query_proto;
1332         case BPF_FUNC_jiffies64:
1333                 return &bpf_jiffies64_proto;
1334         case BPF_FUNC_get_task_stack:
1335                 return &bpf_get_task_stack_proto;
1336         case BPF_FUNC_copy_from_user:
1337                 return prog->aux->sleepable ? &bpf_copy_from_user_proto : NULL;
1338         case BPF_FUNC_snprintf_btf:
1339                 return &bpf_snprintf_btf_proto;
1340         case BPF_FUNC_bpf_per_cpu_ptr:
1341                 return &bpf_per_cpu_ptr_proto;
1342         case BPF_FUNC_bpf_this_cpu_ptr:
1343                 return &bpf_this_cpu_ptr_proto;
1344         default:
1345                 return NULL;
1346         }
1347 }
1348
1349 static const struct bpf_func_proto *
1350 kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1351 {
1352         switch (func_id) {
1353         case BPF_FUNC_perf_event_output:
1354                 return &bpf_perf_event_output_proto;
1355         case BPF_FUNC_get_stackid:
1356                 return &bpf_get_stackid_proto;
1357         case BPF_FUNC_get_stack:
1358                 return &bpf_get_stack_proto;
1359 #ifdef CONFIG_BPF_KPROBE_OVERRIDE
1360         case BPF_FUNC_override_return:
1361                 return &bpf_override_return_proto;
1362 #endif
1363         default:
1364                 return bpf_tracing_func_proto(func_id, prog);
1365         }
1366 }
1367
1368 /* bpf+kprobe programs can access fields of 'struct pt_regs' */
1369 static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
1370                                         const struct bpf_prog *prog,
1371                                         struct bpf_insn_access_aux *info)
1372 {
1373         if (off < 0 || off >= sizeof(struct pt_regs))
1374                 return false;
1375         if (type != BPF_READ)
1376                 return false;
1377         if (off % size != 0)
1378                 return false;
1379         /*
1380          * Assertion for 32 bit to make sure last 8 byte access
1381          * (BPF_DW) to the last 4 byte member is disallowed.
1382          */
1383         if (off + size > sizeof(struct pt_regs))
1384                 return false;
1385
1386         return true;
1387 }
1388
1389 const struct bpf_verifier_ops kprobe_verifier_ops = {
1390         .get_func_proto  = kprobe_prog_func_proto,
1391         .is_valid_access = kprobe_prog_is_valid_access,
1392 };
1393
1394 const struct bpf_prog_ops kprobe_prog_ops = {
1395 };
1396
1397 BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map,
1398            u64, flags, void *, data, u64, size)
1399 {
1400         struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1401
1402         /*
1403          * r1 points to perf tracepoint buffer where first 8 bytes are hidden
1404          * from bpf program and contain a pointer to 'struct pt_regs'. Fetch it
1405          * from there and call the same bpf_perf_event_output() helper inline.
1406          */
1407         return ____bpf_perf_event_output(regs, map, flags, data, size);
1408 }
1409
1410 static const struct bpf_func_proto bpf_perf_event_output_proto_tp = {
1411         .func           = bpf_perf_event_output_tp,
1412         .gpl_only       = true,
1413         .ret_type       = RET_INTEGER,
1414         .arg1_type      = ARG_PTR_TO_CTX,
1415         .arg2_type      = ARG_CONST_MAP_PTR,
1416         .arg3_type      = ARG_ANYTHING,
1417         .arg4_type      = ARG_PTR_TO_MEM,
1418         .arg5_type      = ARG_CONST_SIZE_OR_ZERO,
1419 };
1420
1421 BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map,
1422            u64, flags)
1423 {
1424         struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1425
1426         /*
1427          * Same comment as in bpf_perf_event_output_tp(), only that this time
1428          * the other helper's function body cannot be inlined due to being
1429          * external, thus we need to call raw helper function.
1430          */
1431         return bpf_get_stackid((unsigned long) regs, (unsigned long) map,
1432                                flags, 0, 0);
1433 }
1434
1435 static const struct bpf_func_proto bpf_get_stackid_proto_tp = {
1436         .func           = bpf_get_stackid_tp,
1437         .gpl_only       = true,
1438         .ret_type       = RET_INTEGER,
1439         .arg1_type      = ARG_PTR_TO_CTX,
1440         .arg2_type      = ARG_CONST_MAP_PTR,
1441         .arg3_type      = ARG_ANYTHING,
1442 };
1443
1444 BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size,
1445            u64, flags)
1446 {
1447         struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1448
1449         return bpf_get_stack((unsigned long) regs, (unsigned long) buf,
1450                              (unsigned long) size, flags, 0);
1451 }
1452
1453 static const struct bpf_func_proto bpf_get_stack_proto_tp = {
1454         .func           = bpf_get_stack_tp,
1455         .gpl_only       = true,
1456         .ret_type       = RET_INTEGER,
1457         .arg1_type      = ARG_PTR_TO_CTX,
1458         .arg2_type      = ARG_PTR_TO_UNINIT_MEM,
1459         .arg3_type      = ARG_CONST_SIZE_OR_ZERO,
1460         .arg4_type      = ARG_ANYTHING,
1461 };
1462
1463 static const struct bpf_func_proto *
1464 tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1465 {
1466         switch (func_id) {
1467         case BPF_FUNC_perf_event_output:
1468                 return &bpf_perf_event_output_proto_tp;
1469         case BPF_FUNC_get_stackid:
1470                 return &bpf_get_stackid_proto_tp;
1471         case BPF_FUNC_get_stack:
1472                 return &bpf_get_stack_proto_tp;
1473         default:
1474                 return bpf_tracing_func_proto(func_id, prog);
1475         }
1476 }
1477
1478 static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type,
1479                                     const struct bpf_prog *prog,
1480                                     struct bpf_insn_access_aux *info)
1481 {
1482         if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE)
1483                 return false;
1484         if (type != BPF_READ)
1485                 return false;
1486         if (off % size != 0)
1487                 return false;
1488
1489         BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(__u64));
1490         return true;
1491 }
1492
1493 const struct bpf_verifier_ops tracepoint_verifier_ops = {
1494         .get_func_proto  = tp_prog_func_proto,
1495         .is_valid_access = tp_prog_is_valid_access,
1496 };
1497
1498 const struct bpf_prog_ops tracepoint_prog_ops = {
1499 };
1500
1501 BPF_CALL_3(bpf_perf_prog_read_value, struct bpf_perf_event_data_kern *, ctx,
1502            struct bpf_perf_event_value *, buf, u32, size)
1503 {
1504         int err = -EINVAL;
1505
1506         if (unlikely(size != sizeof(struct bpf_perf_event_value)))
1507                 goto clear;
1508         err = perf_event_read_local(ctx->event, &buf->counter, &buf->enabled,
1509                                     &buf->running);
1510         if (unlikely(err))
1511                 goto clear;
1512         return 0;
1513 clear:
1514         memset(buf, 0, size);
1515         return err;
1516 }
1517
1518 static const struct bpf_func_proto bpf_perf_prog_read_value_proto = {
1519          .func           = bpf_perf_prog_read_value,
1520          .gpl_only       = true,
1521          .ret_type       = RET_INTEGER,
1522          .arg1_type      = ARG_PTR_TO_CTX,
1523          .arg2_type      = ARG_PTR_TO_UNINIT_MEM,
1524          .arg3_type      = ARG_CONST_SIZE,
1525 };
1526
1527 BPF_CALL_4(bpf_read_branch_records, struct bpf_perf_event_data_kern *, ctx,
1528            void *, buf, u32, size, u64, flags)
1529 {
1530 #ifndef CONFIG_X86
1531         return -ENOENT;
1532 #else
1533         static const u32 br_entry_size = sizeof(struct perf_branch_entry);
1534         struct perf_branch_stack *br_stack = ctx->data->br_stack;
1535         u32 to_copy;
1536
1537         if (unlikely(flags & ~BPF_F_GET_BRANCH_RECORDS_SIZE))
1538                 return -EINVAL;
1539
1540         if (unlikely(!br_stack))
1541                 return -EINVAL;
1542
1543         if (flags & BPF_F_GET_BRANCH_RECORDS_SIZE)
1544                 return br_stack->nr * br_entry_size;
1545
1546         if (!buf || (size % br_entry_size != 0))
1547                 return -EINVAL;
1548
1549         to_copy = min_t(u32, br_stack->nr * br_entry_size, size);
1550         memcpy(buf, br_stack->entries, to_copy);
1551
1552         return to_copy;
1553 #endif
1554 }
1555
1556 static const struct bpf_func_proto bpf_read_branch_records_proto = {
1557         .func           = bpf_read_branch_records,
1558         .gpl_only       = true,
1559         .ret_type       = RET_INTEGER,
1560         .arg1_type      = ARG_PTR_TO_CTX,
1561         .arg2_type      = ARG_PTR_TO_MEM_OR_NULL,
1562         .arg3_type      = ARG_CONST_SIZE_OR_ZERO,
1563         .arg4_type      = ARG_ANYTHING,
1564 };
1565
1566 static const struct bpf_func_proto *
1567 pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1568 {
1569         switch (func_id) {
1570         case BPF_FUNC_perf_event_output:
1571                 return &bpf_perf_event_output_proto_tp;
1572         case BPF_FUNC_get_stackid:
1573                 return &bpf_get_stackid_proto_pe;
1574         case BPF_FUNC_get_stack:
1575                 return &bpf_get_stack_proto_pe;
1576         case BPF_FUNC_perf_prog_read_value:
1577                 return &bpf_perf_prog_read_value_proto;
1578         case BPF_FUNC_read_branch_records:
1579                 return &bpf_read_branch_records_proto;
1580         default:
1581                 return bpf_tracing_func_proto(func_id, prog);
1582         }
1583 }
1584
1585 /*
1586  * bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp
1587  * to avoid potential recursive reuse issue when/if tracepoints are added
1588  * inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack.
1589  *
1590  * Since raw tracepoints run despite bpf_prog_active, support concurrent usage
1591  * in normal, irq, and nmi context.
1592  */
1593 struct bpf_raw_tp_regs {
1594         struct pt_regs regs[3];
1595 };
1596 static DEFINE_PER_CPU(struct bpf_raw_tp_regs, bpf_raw_tp_regs);
1597 static DEFINE_PER_CPU(int, bpf_raw_tp_nest_level);
1598 static struct pt_regs *get_bpf_raw_tp_regs(void)
1599 {
1600         struct bpf_raw_tp_regs *tp_regs = this_cpu_ptr(&bpf_raw_tp_regs);
1601         int nest_level = this_cpu_inc_return(bpf_raw_tp_nest_level);
1602
1603         if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(tp_regs->regs))) {
1604                 this_cpu_dec(bpf_raw_tp_nest_level);
1605                 return ERR_PTR(-EBUSY);
1606         }
1607
1608         return &tp_regs->regs[nest_level - 1];
1609 }
1610
1611 static void put_bpf_raw_tp_regs(void)
1612 {
1613         this_cpu_dec(bpf_raw_tp_nest_level);
1614 }
1615
1616 BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args,
1617            struct bpf_map *, map, u64, flags, void *, data, u64, size)
1618 {
1619         struct pt_regs *regs = get_bpf_raw_tp_regs();
1620         int ret;
1621
1622         if (IS_ERR(regs))
1623                 return PTR_ERR(regs);
1624
1625         perf_fetch_caller_regs(regs);
1626         ret = ____bpf_perf_event_output(regs, map, flags, data, size);
1627
1628         put_bpf_raw_tp_regs();
1629         return ret;
1630 }
1631
1632 static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = {
1633         .func           = bpf_perf_event_output_raw_tp,
1634         .gpl_only       = true,
1635         .ret_type       = RET_INTEGER,
1636         .arg1_type      = ARG_PTR_TO_CTX,
1637         .arg2_type      = ARG_CONST_MAP_PTR,
1638         .arg3_type      = ARG_ANYTHING,
1639         .arg4_type      = ARG_PTR_TO_MEM,
1640         .arg5_type      = ARG_CONST_SIZE_OR_ZERO,
1641 };
1642
1643 extern const struct bpf_func_proto bpf_skb_output_proto;
1644 extern const struct bpf_func_proto bpf_xdp_output_proto;
1645
1646 BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args,
1647            struct bpf_map *, map, u64, flags)
1648 {
1649         struct pt_regs *regs = get_bpf_raw_tp_regs();
1650         int ret;
1651
1652         if (IS_ERR(regs))
1653                 return PTR_ERR(regs);
1654
1655         perf_fetch_caller_regs(regs);
1656         /* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */
1657         ret = bpf_get_stackid((unsigned long) regs, (unsigned long) map,
1658                               flags, 0, 0);
1659         put_bpf_raw_tp_regs();
1660         return ret;
1661 }
1662
1663 static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = {
1664         .func           = bpf_get_stackid_raw_tp,
1665         .gpl_only       = true,
1666         .ret_type       = RET_INTEGER,
1667         .arg1_type      = ARG_PTR_TO_CTX,
1668         .arg2_type      = ARG_CONST_MAP_PTR,
1669         .arg3_type      = ARG_ANYTHING,
1670 };
1671
1672 BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args,
1673            void *, buf, u32, size, u64, flags)
1674 {
1675         struct pt_regs *regs = get_bpf_raw_tp_regs();
1676         int ret;
1677
1678         if (IS_ERR(regs))
1679                 return PTR_ERR(regs);
1680
1681         perf_fetch_caller_regs(regs);
1682         ret = bpf_get_stack((unsigned long) regs, (unsigned long) buf,
1683                             (unsigned long) size, flags, 0);
1684         put_bpf_raw_tp_regs();
1685         return ret;
1686 }
1687
1688 static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = {
1689         .func           = bpf_get_stack_raw_tp,
1690         .gpl_only       = true,
1691         .ret_type       = RET_INTEGER,
1692         .arg1_type      = ARG_PTR_TO_CTX,
1693         .arg2_type      = ARG_PTR_TO_MEM,
1694         .arg3_type      = ARG_CONST_SIZE_OR_ZERO,
1695         .arg4_type      = ARG_ANYTHING,
1696 };
1697
1698 static const struct bpf_func_proto *
1699 raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1700 {
1701         switch (func_id) {
1702         case BPF_FUNC_perf_event_output:
1703                 return &bpf_perf_event_output_proto_raw_tp;
1704         case BPF_FUNC_get_stackid:
1705                 return &bpf_get_stackid_proto_raw_tp;
1706         case BPF_FUNC_get_stack:
1707                 return &bpf_get_stack_proto_raw_tp;
1708         default:
1709                 return bpf_tracing_func_proto(func_id, prog);
1710         }
1711 }
1712
1713 const struct bpf_func_proto *
1714 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1715 {
1716         switch (func_id) {
1717 #ifdef CONFIG_NET
1718         case BPF_FUNC_skb_output:
1719                 return &bpf_skb_output_proto;
1720         case BPF_FUNC_xdp_output:
1721                 return &bpf_xdp_output_proto;
1722         case BPF_FUNC_skc_to_tcp6_sock:
1723                 return &bpf_skc_to_tcp6_sock_proto;
1724         case BPF_FUNC_skc_to_tcp_sock:
1725                 return &bpf_skc_to_tcp_sock_proto;
1726         case BPF_FUNC_skc_to_tcp_timewait_sock:
1727                 return &bpf_skc_to_tcp_timewait_sock_proto;
1728         case BPF_FUNC_skc_to_tcp_request_sock:
1729                 return &bpf_skc_to_tcp_request_sock_proto;
1730         case BPF_FUNC_skc_to_udp6_sock:
1731                 return &bpf_skc_to_udp6_sock_proto;
1732 #endif
1733         case BPF_FUNC_seq_printf:
1734                 return prog->expected_attach_type == BPF_TRACE_ITER ?
1735                        &bpf_seq_printf_proto :
1736                        NULL;
1737         case BPF_FUNC_seq_write:
1738                 return prog->expected_attach_type == BPF_TRACE_ITER ?
1739                        &bpf_seq_write_proto :
1740                        NULL;
1741         case BPF_FUNC_seq_printf_btf:
1742                 return prog->expected_attach_type == BPF_TRACE_ITER ?
1743                        &bpf_seq_printf_btf_proto :
1744                        NULL;
1745         case BPF_FUNC_d_path:
1746                 return &bpf_d_path_proto;
1747         default:
1748                 return raw_tp_prog_func_proto(func_id, prog);
1749         }
1750 }
1751
1752 static bool raw_tp_prog_is_valid_access(int off, int size,
1753                                         enum bpf_access_type type,
1754                                         const struct bpf_prog *prog,
1755                                         struct bpf_insn_access_aux *info)
1756 {
1757         if (off < 0 || off >= sizeof(__u64) * MAX_BPF_FUNC_ARGS)
1758                 return false;
1759         if (type != BPF_READ)
1760                 return false;
1761         if (off % size != 0)
1762                 return false;
1763         return true;
1764 }
1765
1766 static bool tracing_prog_is_valid_access(int off, int size,
1767                                          enum bpf_access_type type,
1768                                          const struct bpf_prog *prog,
1769                                          struct bpf_insn_access_aux *info)
1770 {
1771         if (off < 0 || off >= sizeof(__u64) * MAX_BPF_FUNC_ARGS)
1772                 return false;
1773         if (type != BPF_READ)
1774                 return false;
1775         if (off % size != 0)
1776                 return false;
1777         return btf_ctx_access(off, size, type, prog, info);
1778 }
1779
1780 int __weak bpf_prog_test_run_tracing(struct bpf_prog *prog,
1781                                      const union bpf_attr *kattr,
1782                                      union bpf_attr __user *uattr)
1783 {
1784         return -ENOTSUPP;
1785 }
1786
1787 const struct bpf_verifier_ops raw_tracepoint_verifier_ops = {
1788         .get_func_proto  = raw_tp_prog_func_proto,
1789         .is_valid_access = raw_tp_prog_is_valid_access,
1790 };
1791
1792 const struct bpf_prog_ops raw_tracepoint_prog_ops = {
1793 #ifdef CONFIG_NET
1794         .test_run = bpf_prog_test_run_raw_tp,
1795 #endif
1796 };
1797
1798 const struct bpf_verifier_ops tracing_verifier_ops = {
1799         .get_func_proto  = tracing_prog_func_proto,
1800         .is_valid_access = tracing_prog_is_valid_access,
1801 };
1802
1803 const struct bpf_prog_ops tracing_prog_ops = {
1804         .test_run = bpf_prog_test_run_tracing,
1805 };
1806
1807 static bool raw_tp_writable_prog_is_valid_access(int off, int size,
1808                                                  enum bpf_access_type type,
1809                                                  const struct bpf_prog *prog,
1810                                                  struct bpf_insn_access_aux *info)
1811 {
1812         if (off == 0) {
1813                 if (size != sizeof(u64) || type != BPF_READ)
1814                         return false;
1815                 info->reg_type = PTR_TO_TP_BUFFER;
1816         }
1817         return raw_tp_prog_is_valid_access(off, size, type, prog, info);
1818 }
1819
1820 const struct bpf_verifier_ops raw_tracepoint_writable_verifier_ops = {
1821         .get_func_proto  = raw_tp_prog_func_proto,
1822         .is_valid_access = raw_tp_writable_prog_is_valid_access,
1823 };
1824
1825 const struct bpf_prog_ops raw_tracepoint_writable_prog_ops = {
1826 };
1827
1828 static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
1829                                     const struct bpf_prog *prog,
1830                                     struct bpf_insn_access_aux *info)
1831 {
1832         const int size_u64 = sizeof(u64);
1833
1834         if (off < 0 || off >= sizeof(struct bpf_perf_event_data))
1835                 return false;
1836         if (type != BPF_READ)
1837                 return false;
1838         if (off % size != 0) {
1839                 if (sizeof(unsigned long) != 4)
1840                         return false;
1841                 if (size != 8)
1842                         return false;
1843                 if (off % size != 4)
1844                         return false;
1845         }
1846
1847         switch (off) {
1848         case bpf_ctx_range(struct bpf_perf_event_data, sample_period):
1849                 bpf_ctx_record_field_size(info, size_u64);
1850                 if (!bpf_ctx_narrow_access_ok(off, size, size_u64))
1851                         return false;
1852                 break;
1853         case bpf_ctx_range(struct bpf_perf_event_data, addr):
1854                 bpf_ctx_record_field_size(info, size_u64);
1855                 if (!bpf_ctx_narrow_access_ok(off, size, size_u64))
1856                         return false;
1857                 break;
1858         default:
1859                 if (size != sizeof(long))
1860                         return false;
1861         }
1862
1863         return true;
1864 }
1865
1866 static u32 pe_prog_convert_ctx_access(enum bpf_access_type type,
1867                                       const struct bpf_insn *si,
1868                                       struct bpf_insn *insn_buf,
1869                                       struct bpf_prog *prog, u32 *target_size)
1870 {
1871         struct bpf_insn *insn = insn_buf;
1872
1873         switch (si->off) {
1874         case offsetof(struct bpf_perf_event_data, sample_period):
1875                 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
1876                                                        data), si->dst_reg, si->src_reg,
1877                                       offsetof(struct bpf_perf_event_data_kern, data));
1878                 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg,
1879                                       bpf_target_off(struct perf_sample_data, period, 8,
1880                                                      target_size));
1881                 break;
1882         case offsetof(struct bpf_perf_event_data, addr):
1883                 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
1884                                                        data), si->dst_reg, si->src_reg,
1885                                       offsetof(struct bpf_perf_event_data_kern, data));
1886                 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg,
1887                                       bpf_target_off(struct perf_sample_data, addr, 8,
1888                                                      target_size));
1889                 break;
1890         default:
1891                 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
1892                                                        regs), si->dst_reg, si->src_reg,
1893                                       offsetof(struct bpf_perf_event_data_kern, regs));
1894                 *insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg,
1895                                       si->off);
1896                 break;
1897         }
1898
1899         return insn - insn_buf;
1900 }
1901
1902 const struct bpf_verifier_ops perf_event_verifier_ops = {
1903         .get_func_proto         = pe_prog_func_proto,
1904         .is_valid_access        = pe_prog_is_valid_access,
1905         .convert_ctx_access     = pe_prog_convert_ctx_access,
1906 };
1907
1908 const struct bpf_prog_ops perf_event_prog_ops = {
1909 };
1910
1911 static DEFINE_MUTEX(bpf_event_mutex);
1912
1913 #define BPF_TRACE_MAX_PROGS 64
1914
1915 int perf_event_attach_bpf_prog(struct perf_event *event,
1916                                struct bpf_prog *prog)
1917 {
1918         struct bpf_prog_array *old_array;
1919         struct bpf_prog_array *new_array;
1920         int ret = -EEXIST;
1921
1922         /*
1923          * Kprobe override only works if they are on the function entry,
1924          * and only if they are on the opt-in list.
1925          */
1926         if (prog->kprobe_override &&
1927             (!trace_kprobe_on_func_entry(event->tp_event) ||
1928              !trace_kprobe_error_injectable(event->tp_event)))
1929                 return -EINVAL;
1930
1931         mutex_lock(&bpf_event_mutex);
1932
1933         if (event->prog)
1934                 goto unlock;
1935
1936         old_array = bpf_event_rcu_dereference(event->tp_event->prog_array);
1937         if (old_array &&
1938             bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) {
1939                 ret = -E2BIG;
1940                 goto unlock;
1941         }
1942
1943         ret = bpf_prog_array_copy(old_array, NULL, prog, &new_array);
1944         if (ret < 0)
1945                 goto unlock;
1946
1947         /* set the new array to event->tp_event and set event->prog */
1948         event->prog = prog;
1949         rcu_assign_pointer(event->tp_event->prog_array, new_array);
1950         bpf_prog_array_free(old_array);
1951
1952 unlock:
1953         mutex_unlock(&bpf_event_mutex);
1954         return ret;
1955 }
1956
1957 void perf_event_detach_bpf_prog(struct perf_event *event)
1958 {
1959         struct bpf_prog_array *old_array;
1960         struct bpf_prog_array *new_array;
1961         int ret;
1962
1963         mutex_lock(&bpf_event_mutex);
1964
1965         if (!event->prog)
1966                 goto unlock;
1967
1968         old_array = bpf_event_rcu_dereference(event->tp_event->prog_array);
1969         ret = bpf_prog_array_copy(old_array, event->prog, NULL, &new_array);
1970         if (ret == -ENOENT)
1971                 goto unlock;
1972         if (ret < 0) {
1973                 bpf_prog_array_delete_safe(old_array, event->prog);
1974         } else {
1975                 rcu_assign_pointer(event->tp_event->prog_array, new_array);
1976                 bpf_prog_array_free(old_array);
1977         }
1978
1979         bpf_prog_put(event->prog);
1980         event->prog = NULL;
1981
1982 unlock:
1983         mutex_unlock(&bpf_event_mutex);
1984 }
1985
1986 int perf_event_query_prog_array(struct perf_event *event, void __user *info)
1987 {
1988         struct perf_event_query_bpf __user *uquery = info;
1989         struct perf_event_query_bpf query = {};
1990         struct bpf_prog_array *progs;
1991         u32 *ids, prog_cnt, ids_len;
1992         int ret;
1993
1994         if (!perfmon_capable())
1995                 return -EPERM;
1996         if (event->attr.type != PERF_TYPE_TRACEPOINT)
1997                 return -EINVAL;
1998         if (copy_from_user(&query, uquery, sizeof(query)))
1999                 return -EFAULT;
2000
2001         ids_len = query.ids_len;
2002         if (ids_len > BPF_TRACE_MAX_PROGS)
2003                 return -E2BIG;
2004         ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN);
2005         if (!ids)
2006                 return -ENOMEM;
2007         /*
2008          * The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which
2009          * is required when user only wants to check for uquery->prog_cnt.
2010          * There is no need to check for it since the case is handled
2011          * gracefully in bpf_prog_array_copy_info.
2012          */
2013
2014         mutex_lock(&bpf_event_mutex);
2015         progs = bpf_event_rcu_dereference(event->tp_event->prog_array);
2016         ret = bpf_prog_array_copy_info(progs, ids, ids_len, &prog_cnt);
2017         mutex_unlock(&bpf_event_mutex);
2018
2019         if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) ||
2020             copy_to_user(uquery->ids, ids, ids_len * sizeof(u32)))
2021                 ret = -EFAULT;
2022
2023         kfree(ids);
2024         return ret;
2025 }
2026
2027 extern struct bpf_raw_event_map __start__bpf_raw_tp[];
2028 extern struct bpf_raw_event_map __stop__bpf_raw_tp[];
2029
2030 struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name)
2031 {
2032         struct bpf_raw_event_map *btp = __start__bpf_raw_tp;
2033
2034         for (; btp < __stop__bpf_raw_tp; btp++) {
2035                 if (!strcmp(btp->tp->name, name))
2036                         return btp;
2037         }
2038
2039         return bpf_get_raw_tracepoint_module(name);
2040 }
2041
2042 void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp)
2043 {
2044         struct module *mod = __module_address((unsigned long)btp);
2045
2046         if (mod)
2047                 module_put(mod);
2048 }
2049
2050 static __always_inline
2051 void __bpf_trace_run(struct bpf_prog *prog, u64 *args)
2052 {
2053         cant_sleep();
2054         rcu_read_lock();
2055         (void) BPF_PROG_RUN(prog, args);
2056         rcu_read_unlock();
2057 }
2058
2059 #define UNPACK(...)                     __VA_ARGS__
2060 #define REPEAT_1(FN, DL, X, ...)        FN(X)
2061 #define REPEAT_2(FN, DL, X, ...)        FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__)
2062 #define REPEAT_3(FN, DL, X, ...)        FN(X) UNPACK DL REPEAT_2(FN, DL, __VA_ARGS__)
2063 #define REPEAT_4(FN, DL, X, ...)        FN(X) UNPACK DL REPEAT_3(FN, DL, __VA_ARGS__)
2064 #define REPEAT_5(FN, DL, X, ...)        FN(X) UNPACK DL REPEAT_4(FN, DL, __VA_ARGS__)
2065 #define REPEAT_6(FN, DL, X, ...)        FN(X) UNPACK DL REPEAT_5(FN, DL, __VA_ARGS__)
2066 #define REPEAT_7(FN, DL, X, ...)        FN(X) UNPACK DL REPEAT_6(FN, DL, __VA_ARGS__)
2067 #define REPEAT_8(FN, DL, X, ...)        FN(X) UNPACK DL REPEAT_7(FN, DL, __VA_ARGS__)
2068 #define REPEAT_9(FN, DL, X, ...)        FN(X) UNPACK DL REPEAT_8(FN, DL, __VA_ARGS__)
2069 #define REPEAT_10(FN, DL, X, ...)       FN(X) UNPACK DL REPEAT_9(FN, DL, __VA_ARGS__)
2070 #define REPEAT_11(FN, DL, X, ...)       FN(X) UNPACK DL REPEAT_10(FN, DL, __VA_ARGS__)
2071 #define REPEAT_12(FN, DL, X, ...)       FN(X) UNPACK DL REPEAT_11(FN, DL, __VA_ARGS__)
2072 #define REPEAT(X, FN, DL, ...)          REPEAT_##X(FN, DL, __VA_ARGS__)
2073
2074 #define SARG(X)         u64 arg##X
2075 #define COPY(X)         args[X] = arg##X
2076
2077 #define __DL_COM        (,)
2078 #define __DL_SEM        (;)
2079
2080 #define __SEQ_0_11      0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11
2081
2082 #define BPF_TRACE_DEFN_x(x)                                             \
2083         void bpf_trace_run##x(struct bpf_prog *prog,                    \
2084                               REPEAT(x, SARG, __DL_COM, __SEQ_0_11))    \
2085         {                                                               \
2086                 u64 args[x];                                            \
2087                 REPEAT(x, COPY, __DL_SEM, __SEQ_0_11);                  \
2088                 __bpf_trace_run(prog, args);                            \
2089         }                                                               \
2090         EXPORT_SYMBOL_GPL(bpf_trace_run##x)
2091 BPF_TRACE_DEFN_x(1);
2092 BPF_TRACE_DEFN_x(2);
2093 BPF_TRACE_DEFN_x(3);
2094 BPF_TRACE_DEFN_x(4);
2095 BPF_TRACE_DEFN_x(5);
2096 BPF_TRACE_DEFN_x(6);
2097 BPF_TRACE_DEFN_x(7);
2098 BPF_TRACE_DEFN_x(8);
2099 BPF_TRACE_DEFN_x(9);
2100 BPF_TRACE_DEFN_x(10);
2101 BPF_TRACE_DEFN_x(11);
2102 BPF_TRACE_DEFN_x(12);
2103
2104 static int __bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog)
2105 {
2106         struct tracepoint *tp = btp->tp;
2107
2108         /*
2109          * check that program doesn't access arguments beyond what's
2110          * available in this tracepoint
2111          */
2112         if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64))
2113                 return -EINVAL;
2114
2115         if (prog->aux->max_tp_access > btp->writable_size)
2116                 return -EINVAL;
2117
2118         return tracepoint_probe_register(tp, (void *)btp->bpf_func, prog);
2119 }
2120
2121 int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog)
2122 {
2123         return __bpf_probe_register(btp, prog);
2124 }
2125
2126 int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_prog *prog)
2127 {
2128         return tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, prog);
2129 }
2130
2131 int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id,
2132                             u32 *fd_type, const char **buf,
2133                             u64 *probe_offset, u64 *probe_addr)
2134 {
2135         bool is_tracepoint, is_syscall_tp;
2136         struct bpf_prog *prog;
2137         int flags, err = 0;
2138
2139         prog = event->prog;
2140         if (!prog)
2141                 return -ENOENT;
2142
2143         /* not supporting BPF_PROG_TYPE_PERF_EVENT yet */
2144         if (prog->type == BPF_PROG_TYPE_PERF_EVENT)
2145                 return -EOPNOTSUPP;
2146
2147         *prog_id = prog->aux->id;
2148         flags = event->tp_event->flags;
2149         is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT;
2150         is_syscall_tp = is_syscall_trace_event(event->tp_event);
2151
2152         if (is_tracepoint || is_syscall_tp) {
2153                 *buf = is_tracepoint ? event->tp_event->tp->name
2154                                      : event->tp_event->name;
2155                 *fd_type = BPF_FD_TYPE_TRACEPOINT;
2156                 *probe_offset = 0x0;
2157                 *probe_addr = 0x0;
2158         } else {
2159                 /* kprobe/uprobe */
2160                 err = -EOPNOTSUPP;
2161 #ifdef CONFIG_KPROBE_EVENTS
2162                 if (flags & TRACE_EVENT_FL_KPROBE)
2163                         err = bpf_get_kprobe_info(event, fd_type, buf,
2164                                                   probe_offset, probe_addr,
2165                                                   event->attr.type == PERF_TYPE_TRACEPOINT);
2166 #endif
2167 #ifdef CONFIG_UPROBE_EVENTS
2168                 if (flags & TRACE_EVENT_FL_UPROBE)
2169                         err = bpf_get_uprobe_info(event, fd_type, buf,
2170                                                   probe_offset,
2171                                                   event->attr.type == PERF_TYPE_TRACEPOINT);
2172 #endif
2173         }
2174
2175         return err;
2176 }
2177
2178 static int __init send_signal_irq_work_init(void)
2179 {
2180         int cpu;
2181         struct send_signal_irq_work *work;
2182
2183         for_each_possible_cpu(cpu) {
2184                 work = per_cpu_ptr(&send_signal_work, cpu);
2185                 init_irq_work(&work->irq_work, do_bpf_send_signal);
2186         }
2187         return 0;
2188 }
2189
2190 subsys_initcall(send_signal_irq_work_init);
2191
2192 #ifdef CONFIG_MODULES
2193 static int bpf_event_notify(struct notifier_block *nb, unsigned long op,
2194                             void *module)
2195 {
2196         struct bpf_trace_module *btm, *tmp;
2197         struct module *mod = module;
2198         int ret = 0;
2199
2200         if (mod->num_bpf_raw_events == 0 ||
2201             (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING))
2202                 goto out;
2203
2204         mutex_lock(&bpf_module_mutex);
2205
2206         switch (op) {
2207         case MODULE_STATE_COMING:
2208                 btm = kzalloc(sizeof(*btm), GFP_KERNEL);
2209                 if (btm) {
2210                         btm->module = module;
2211                         list_add(&btm->list, &bpf_trace_modules);
2212                 } else {
2213                         ret = -ENOMEM;
2214                 }
2215                 break;
2216         case MODULE_STATE_GOING:
2217                 list_for_each_entry_safe(btm, tmp, &bpf_trace_modules, list) {
2218                         if (btm->module == module) {
2219                                 list_del(&btm->list);
2220                                 kfree(btm);
2221                                 break;
2222                         }
2223                 }
2224                 break;
2225         }
2226
2227         mutex_unlock(&bpf_module_mutex);
2228
2229 out:
2230         return notifier_from_errno(ret);
2231 }
2232
2233 static struct notifier_block bpf_module_nb = {
2234         .notifier_call = bpf_event_notify,
2235 };
2236
2237 static int __init bpf_event_init(void)
2238 {
2239         register_module_notifier(&bpf_module_nb);
2240         return 0;
2241 }
2242
2243 fs_initcall(bpf_event_init);
2244 #endif /* CONFIG_MODULES */