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         cant_sleep();
  97
  98         if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) {
  99                 /*
 100                  * since some bpf program is already running on this cpu,
 101                  * don't call into another bpf program (same or different)
 102                  * and don't send kprobe event into ring-buffer,
 103                  * so return zero here
 104                  */
 105                 ret = 0;
 106                 goto out;
 107         }
 108
 109         /*
 110          * Instead of moving rcu_read_lock/rcu_dereference/rcu_read_unlock
 111          * to all call sites, we did a bpf_prog_array_valid() there to check
 112          * whether call->prog_array is empty or not, which is
 113          * a heurisitc to speed up execution.
 114          *
 115          * If bpf_prog_array_valid() fetched prog_array was
 116          * non-NULL, we go into trace_call_bpf() and do the actual
 117          * proper rcu_dereference() under RCU lock.
 118          * If it turns out that prog_array is NULL then, we bail out.
 119          * For the opposite, if the bpf_prog_array_valid() fetched pointer
 120          * was NULL, you'll skip the prog_array with the risk of missing
 121          * out of events when it was updated in between this and the
 122          * rcu_dereference() which is accepted risk.
 123          */
 124         ret = BPF_PROG_RUN_ARRAY_CHECK(call->prog_array, ctx, BPF_PROG_RUN);
 125
 126  out:
 127         __this_cpu_dec(bpf_prog_active);
 128
 129         return ret;
 130 }
 131
 132 #ifdef CONFIG_BPF_KPROBE_OVERRIDE
 133 BPF_CALL_2(bpf_override_return, struct pt_regs *, regs, unsigned long, rc)
 134 {
 135         regs_set_return_value(regs, rc);
 136         override_function_with_return(regs);
 137         return 0;
 138 }
 139
 140 static const struct bpf_func_proto bpf_override_return_proto = {
 141         .func           = bpf_override_return,
 142         .gpl_only       = true,
 143         .ret_type       = RET_INTEGER,
 144         .arg1_type      = ARG_PTR_TO_CTX,
 145         .arg2_type      = ARG_ANYTHING,
 146 };
 147 #endif
 148
 149 static __always_inline int
 150 bpf_probe_read_user_common(void *dst, u32 size, const void __user *unsafe_ptr)
 151 {
 152         int ret;
 153
 154         ret = copy_from_user_nofault(dst, unsafe_ptr, size);
 155         if (unlikely(ret < 0))
 156                 memset(dst, 0, size);
 157         return ret;
 158 }
 159
 160 BPF_CALL_3(bpf_probe_read_user, void *, dst, u32, size,
 161            const void __user *, unsafe_ptr)
 162 {
 163         return bpf_probe_read_user_common(dst, size, unsafe_ptr);
 164 }
 165
 166 const struct bpf_func_proto bpf_probe_read_user_proto = {
 167         .func           = bpf_probe_read_user,
 168         .gpl_only       = true,
 169         .ret_type       = RET_INTEGER,
 170         .arg1_type      = ARG_PTR_TO_UNINIT_MEM,
 171         .arg2_type      = ARG_CONST_SIZE_OR_ZERO,
 172         .arg3_type      = ARG_ANYTHING,
 173 };
 174
 175 static __always_inline int
 176 bpf_probe_read_user_str_common(void *dst, u32 size,
 177                                const void __user *unsafe_ptr)
 178 {
 179         int ret;
 180
 181         /*
 182          * NB: We rely on strncpy_from_user() not copying junk past the NUL
 183          * terminator into `dst`.
 184          *
 185          * strncpy_from_user() does long-sized strides in the fast path. If the
 186          * strncpy does not mask out the bytes after the NUL in `unsafe_ptr`,
 187          * then there could be junk after the NUL in `dst`. If user takes `dst`
 188          * and keys a hash map with it, then semantically identical strings can
 189          * occupy multiple entries in the map.
 190          */
 191         ret = strncpy_from_user_nofault(dst, unsafe_ptr, size);
 192         if (unlikely(ret < 0))
 193                 memset(dst, 0, size);
 194         return ret;
 195 }
 196
 197 BPF_CALL_3(bpf_probe_read_user_str, void *, dst, u32, size,
 198            const void __user *, unsafe_ptr)
 199 {
 200         return bpf_probe_read_user_str_common(dst, size, unsafe_ptr);
 201 }
 202
 203 const struct bpf_func_proto bpf_probe_read_user_str_proto = {
 204         .func           = bpf_probe_read_user_str,
 205         .gpl_only       = true,
 206         .ret_type       = RET_INTEGER,
 207         .arg1_type      = ARG_PTR_TO_UNINIT_MEM,
 208         .arg2_type      = ARG_CONST_SIZE_OR_ZERO,
 209         .arg3_type      = ARG_ANYTHING,
 210 };
 211
 212 static __always_inline int
 213 bpf_probe_read_kernel_common(void *dst, u32 size, const void *unsafe_ptr)
 214 {
 215         int ret;
 216
 217         ret = copy_from_kernel_nofault(dst, unsafe_ptr, size);
 218         if (unlikely(ret < 0))
 219                 memset(dst, 0, size);
 220         return ret;
 221 }
 222
 223 BPF_CALL_3(bpf_probe_read_kernel, void *, dst, u32, size,
 224            const void *, unsafe_ptr)
 225 {
 226         return bpf_probe_read_kernel_common(dst, size, unsafe_ptr);
 227 }
 228
 229 const struct bpf_func_proto bpf_probe_read_kernel_proto = {
 230         .func           = bpf_probe_read_kernel,
 231         .gpl_only       = true,
 232         .ret_type       = RET_INTEGER,
 233         .arg1_type      = ARG_PTR_TO_UNINIT_MEM,
 234         .arg2_type      = ARG_CONST_SIZE_OR_ZERO,
 235         .arg3_type      = ARG_ANYTHING,
 236 };
 237
 238 static __always_inline int
 239 bpf_probe_read_kernel_str_common(void *dst, u32 size, const void *unsafe_ptr)
 240 {
 241         int ret;
 242
 243         /*
 244          * The strncpy_from_kernel_nofault() call will likely not fill the
 245          * entire buffer, but that's okay in this circumstance as we're probing
 246          * arbitrary memory anyway similar to bpf_probe_read_*() and might
 247          * as well probe the stack. Thus, memory is explicitly cleared
 248          * only in error case, so that improper users ignoring return
 249          * code altogether don't copy garbage; otherwise length of string
 250          * is returned that can be used for bpf_perf_event_output() et al.
 251          */
 252         ret = strncpy_from_kernel_nofault(dst, unsafe_ptr, size);
 253         if (unlikely(ret < 0))
 254                 memset(dst, 0, size);
 255         return ret;
 256 }
 257
 258 BPF_CALL_3(bpf_probe_read_kernel_str, void *, dst, u32, size,
 259            const void *, unsafe_ptr)
 260 {
 261         return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr);
 262 }
 263
 264 const struct bpf_func_proto bpf_probe_read_kernel_str_proto = {
 265         .func           = bpf_probe_read_kernel_str,
 266         .gpl_only       = true,
 267         .ret_type       = RET_INTEGER,
 268         .arg1_type      = ARG_PTR_TO_UNINIT_MEM,
 269         .arg2_type      = ARG_CONST_SIZE_OR_ZERO,
 270         .arg3_type      = ARG_ANYTHING,
 271 };
 272
 273 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
 274 BPF_CALL_3(bpf_probe_read_compat, void *, dst, u32, size,
 275            const void *, unsafe_ptr)
 276 {
 277         if ((unsigned long)unsafe_ptr < TASK_SIZE) {
 278                 return bpf_probe_read_user_common(dst, size,
 279                                 (__force void __user *)unsafe_ptr);
 280         }
 281         return bpf_probe_read_kernel_common(dst, size, unsafe_ptr);
 282 }
 283
 284 static const struct bpf_func_proto bpf_probe_read_compat_proto = {
 285         .func           = bpf_probe_read_compat,
 286         .gpl_only       = true,
 287         .ret_type       = RET_INTEGER,
 288         .arg1_type      = ARG_PTR_TO_UNINIT_MEM,
 289         .arg2_type      = ARG_CONST_SIZE_OR_ZERO,
 290         .arg3_type      = ARG_ANYTHING,
 291 };
 292
 293 BPF_CALL_3(bpf_probe_read_compat_str, void *, dst, u32, size,
 294            const void *, unsafe_ptr)
 295 {
 296         if ((unsigned long)unsafe_ptr < TASK_SIZE) {
 297                 return bpf_probe_read_user_str_common(dst, size,
 298                                 (__force void __user *)unsafe_ptr);
 299         }
 300         return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr);
 301 }
 302
 303 static const struct bpf_func_proto bpf_probe_read_compat_str_proto = {
 304         .func           = bpf_probe_read_compat_str,
 305         .gpl_only       = true,
 306         .ret_type       = RET_INTEGER,
 307         .arg1_type      = ARG_PTR_TO_UNINIT_MEM,
 308         .arg2_type      = ARG_CONST_SIZE_OR_ZERO,
 309         .arg3_type      = ARG_ANYTHING,
 310 };
 311 #endif /* CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE */
 312
 313 BPF_CALL_3(bpf_probe_write_user, void __user *, unsafe_ptr, const void *, src,
 314            u32, size)
 315 {
 316         /*
 317          * Ensure we're in user context which is safe for the helper to
 318          * run. This helper has no business in a kthread.
 319          *
 320          * access_ok() should prevent writing to non-user memory, but in
 321          * some situations (nommu, temporary switch, etc) access_ok() does
 322          * not provide enough validation, hence the check on KERNEL_DS.
 323          *
 324          * nmi_uaccess_okay() ensures the probe is not run in an interim
 325          * state, when the task or mm are switched. This is specifically
 326          * required to prevent the use of temporary mm.
 327          */
 328
 329         if (unlikely(in_interrupt() ||
 330                      current->flags & (PF_KTHREAD | PF_EXITING)))
 331                 return -EPERM;
 332         if (unlikely(uaccess_kernel()))
 333                 return -EPERM;
 334         if (unlikely(!nmi_uaccess_okay()))
 335                 return -EPERM;
 336
 337         return copy_to_user_nofault(unsafe_ptr, src, size);
 338 }
 339
 340 static const struct bpf_func_proto bpf_probe_write_user_proto = {
 341         .func           = bpf_probe_write_user,
 342         .gpl_only       = true,
 343         .ret_type       = RET_INTEGER,
 344         .arg1_type      = ARG_ANYTHING,
 345         .arg2_type      = ARG_PTR_TO_MEM,
 346         .arg3_type      = ARG_CONST_SIZE,
 347 };
 348
 349 static const struct bpf_func_proto *bpf_get_probe_write_proto(void)
 350 {
 351         if (!capable(CAP_SYS_ADMIN))
 352                 return NULL;
 353
 354         pr_warn_ratelimited("%s[%d] is installing a program with bpf_probe_write_user helper that may corrupt user memory!",
 355                             current->comm, task_pid_nr(current));
 356
 357         return &bpf_probe_write_user_proto;
 358 }
 359
 360 static void bpf_trace_copy_string(char *buf, void *unsafe_ptr, char fmt_ptype,
 361                 size_t bufsz)
 362 {
 363         void __user *user_ptr = (__force void __user *)unsafe_ptr;
 364
 365         buf[0] = 0;
 366
 367         switch (fmt_ptype) {
 368         case 's':
 369 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
 370                 if ((unsigned long)unsafe_ptr < TASK_SIZE) {
 371                         strncpy_from_user_nofault(buf, user_ptr, bufsz);
 372                         break;
 373                 }
 374                 fallthrough;
 375 #endif
 376         case 'k':
 377                 strncpy_from_kernel_nofault(buf, unsafe_ptr, bufsz);
 378                 break;
 379         case 'u':
 380                 strncpy_from_user_nofault(buf, user_ptr, bufsz);
 381                 break;
 382         }
 383 }
 384
 385 static DEFINE_RAW_SPINLOCK(trace_printk_lock);
 386
 387 #define BPF_TRACE_PRINTK_SIZE   1024
 388
 389 static __printf(1, 0) int bpf_do_trace_printk(const char *fmt, ...)
 390 {
 391         static char buf[BPF_TRACE_PRINTK_SIZE];
 392         unsigned long flags;
 393         va_list ap;
 394         int ret;
 395
 396         raw_spin_lock_irqsave(&trace_printk_lock, flags);
 397         va_start(ap, fmt);
 398         ret = vsnprintf(buf, sizeof(buf), fmt, ap);
 399         va_end(ap);
 400         /* vsnprintf() will not append null for zero-length strings */
 401         if (ret == 0)
 402                 buf[0] = '\0';
 403         trace_bpf_trace_printk(buf);
 404         raw_spin_unlock_irqrestore(&trace_printk_lock, flags);
 405
 406         return ret;
 407 }
 408
 409 /*
 410  * Only limited trace_printk() conversion specifiers allowed:
 411  * %d %i %u %x %ld %li %lu %lx %lld %lli %llu %llx %p %pB %pks %pus %s
 412  */
 413 BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1,
 414            u64, arg2, u64, arg3)
 415 {
 416         int i, mod[3] = {}, fmt_cnt = 0;
 417         char buf[64], fmt_ptype;
 418         void *unsafe_ptr = NULL;
 419         bool str_seen = false;
 420
 421         /*
 422          * bpf_check()->check_func_arg()->check_stack_boundary()
 423          * guarantees that fmt points to bpf program stack,
 424          * fmt_size bytes of it were initialized and fmt_size > 0
 425          */
 426         if (fmt[--fmt_size] != 0)
 427                 return -EINVAL;
 428
 429         /* check format string for allowed specifiers */
 430         for (i = 0; i < fmt_size; i++) {
 431                 if ((!isprint(fmt[i]) && !isspace(fmt[i])) || !isascii(fmt[i]))
 432                         return -EINVAL;
 433
 434                 if (fmt[i] != '%')
 435                         continue;
 436
 437                 if (fmt_cnt >= 3)
 438                         return -EINVAL;
 439
 440                 /* fmt[i] != 0 && fmt[last] == 0, so we can access fmt[i + 1] */
 441                 i++;
 442                 if (fmt[i] == 'l') {
 443                         mod[fmt_cnt]++;
 444                         i++;
 445                 } else if (fmt[i] == 'p') {
 446                         mod[fmt_cnt]++;
 447                         if ((fmt[i + 1] == 'k' ||
 448                              fmt[i + 1] == 'u') &&
 449                             fmt[i + 2] == 's') {
 450                                 fmt_ptype = fmt[i + 1];
 451                                 i += 2;
 452                                 goto fmt_str;
 453                         }
 454
 455                         if (fmt[i + 1] == 'B') {
 456                                 i++;
 457                                 goto fmt_next;
 458                         }
 459
 460                         /* disallow any further format extensions */
 461                         if (fmt[i + 1] != 0 &&
 462                             !isspace(fmt[i + 1]) &&
 463                             !ispunct(fmt[i + 1]))
 464                                 return -EINVAL;
 465
 466                         goto fmt_next;
 467                 } else if (fmt[i] == 's') {
 468                         mod[fmt_cnt]++;
 469                         fmt_ptype = fmt[i];
 470 fmt_str:
 471                         if (str_seen)
 472                                 /* allow only one '%s' per fmt string */
 473                                 return -EINVAL;
 474                         str_seen = true;
 475
 476                         if (fmt[i + 1] != 0 &&
 477                             !isspace(fmt[i + 1]) &&
 478                             !ispunct(fmt[i + 1]))
 479                                 return -EINVAL;
 480
 481                         switch (fmt_cnt) {
 482                         case 0:
 483                                 unsafe_ptr = (void *)(long)arg1;
 484                                 arg1 = (long)buf;
 485                                 break;
 486                         case 1:
 487                                 unsafe_ptr = (void *)(long)arg2;
 488                                 arg2 = (long)buf;
 489                                 break;
 490                         case 2:
 491                                 unsafe_ptr = (void *)(long)arg3;
 492                                 arg3 = (long)buf;
 493                                 break;
 494                         }
 495
 496                         bpf_trace_copy_string(buf, unsafe_ptr, fmt_ptype,
 497                                         sizeof(buf));
 498                         goto fmt_next;
 499                 }
 500
 501                 if (fmt[i] == 'l') {
 502                         mod[fmt_cnt]++;
 503                         i++;
 504                 }
 505
 506                 if (fmt[i] != 'i' && fmt[i] != 'd' &&
 507                     fmt[i] != 'u' && fmt[i] != 'x')
 508                         return -EINVAL;
 509 fmt_next:
 510                 fmt_cnt++;
 511         }
 512
 513 /* Horrid workaround for getting va_list handling working with different
 514  * argument type combinations generically for 32 and 64 bit archs.
 515  */
 516 #define __BPF_TP_EMIT() __BPF_ARG3_TP()
 517 #define __BPF_TP(...)                                                   \
 518         bpf_do_trace_printk(fmt, ##__VA_ARGS__)
 519
 520 #define __BPF_ARG1_TP(...)                                              \
 521         ((mod[0] == 2 || (mod[0] == 1 && __BITS_PER_LONG == 64))        \
 522           ? __BPF_TP(arg1, ##__VA_ARGS__)                               \
 523           : ((mod[0] == 1 || (mod[0] == 0 && __BITS_PER_LONG == 32))    \
 524               ? __BPF_TP((long)arg1, ##__VA_ARGS__)                     \
 525               : __BPF_TP((u32)arg1, ##__VA_ARGS__)))
 526
 527 #define __BPF_ARG2_TP(...)                                              \
 528         ((mod[1] == 2 || (mod[1] == 1 && __BITS_PER_LONG == 64))        \
 529           ? __BPF_ARG1_TP(arg2, ##__VA_ARGS__)                          \
 530           : ((mod[1] == 1 || (mod[1] == 0 && __BITS_PER_LONG == 32))    \
 531               ? __BPF_ARG1_TP((long)arg2, ##__VA_ARGS__)                \
 532               : __BPF_ARG1_TP((u32)arg2, ##__VA_ARGS__)))
 533
 534 #define __BPF_ARG3_TP(...)                                              \
 535         ((mod[2] == 2 || (mod[2] == 1 && __BITS_PER_LONG == 64))        \
 536           ? __BPF_ARG2_TP(arg3, ##__VA_ARGS__)                          \
 537           : ((mod[2] == 1 || (mod[2] == 0 && __BITS_PER_LONG == 32))    \
 538               ? __BPF_ARG2_TP((long)arg3, ##__VA_ARGS__)                \
 539               : __BPF_ARG2_TP((u32)arg3, ##__VA_ARGS__)))
 540
 541         return __BPF_TP_EMIT();
 542 }
 543
 544 static const struct bpf_func_proto bpf_trace_printk_proto = {
 545         .func           = bpf_trace_printk,
 546         .gpl_only       = true,
 547         .ret_type       = RET_INTEGER,
 548         .arg1_type      = ARG_PTR_TO_MEM,
 549         .arg2_type      = ARG_CONST_SIZE,
 550 };
 551
 552 const struct bpf_func_proto *bpf_get_trace_printk_proto(void)
 553 {
 554         /*
 555          * This program might be calling bpf_trace_printk,
 556          * so enable the associated bpf_trace/bpf_trace_printk event.
 557          * Repeat this each time as it is possible a user has
 558          * disabled bpf_trace_printk events.  By loading a program
 559          * calling bpf_trace_printk() however the user has expressed
 560          * the intent to see such events.
 561          */
 562         if (trace_set_clr_event("bpf_trace", "bpf_trace_printk", 1))
 563                 pr_warn_ratelimited("could not enable bpf_trace_printk events");
 564
 565         return &bpf_trace_printk_proto;
 566 }
 567
 568 #define MAX_SEQ_PRINTF_VARARGS          12
 569 #define MAX_SEQ_PRINTF_MAX_MEMCPY       6
 570 #define MAX_SEQ_PRINTF_STR_LEN          128
 571
 572 struct bpf_seq_printf_buf {
 573         char buf[MAX_SEQ_PRINTF_MAX_MEMCPY][MAX_SEQ_PRINTF_STR_LEN];
 574 };
 575 static DEFINE_PER_CPU(struct bpf_seq_printf_buf, bpf_seq_printf_buf);
 576 static DEFINE_PER_CPU(int, bpf_seq_printf_buf_used);
 577
 578 BPF_CALL_5(bpf_seq_printf, struct seq_file *, m, char *, fmt, u32, fmt_size,
 579            const void *, data, u32, data_len)
 580 {
 581         int err = -EINVAL, fmt_cnt = 0, memcpy_cnt = 0;
 582         int i, buf_used, copy_size, num_args;
 583         u64 params[MAX_SEQ_PRINTF_VARARGS];
 584         struct bpf_seq_printf_buf *bufs;
 585         const u64 *args = data;
 586
 587         buf_used = this_cpu_inc_return(bpf_seq_printf_buf_used);
 588         if (WARN_ON_ONCE(buf_used > 1)) {
 589                 err = -EBUSY;
 590                 goto out;
 591         }
 592
 593         bufs = this_cpu_ptr(&bpf_seq_printf_buf);
 594
 595         /*
 596          * bpf_check()->check_func_arg()->check_stack_boundary()
 597          * guarantees that fmt points to bpf program stack,
 598          * fmt_size bytes of it were initialized and fmt_size > 0
 599          */
 600         if (fmt[--fmt_size] != 0)
 601                 goto out;
 602
 603         if (data_len & 7)
 604                 goto out;
 605
 606         for (i = 0; i < fmt_size; i++) {
 607                 if (fmt[i] == '%') {
 608                         if (fmt[i + 1] == '%')
 609                                 i++;
 610                         else if (!data || !data_len)
 611                                 goto out;
 612                 }
 613         }
 614
 615         num_args = data_len / 8;
 616
 617         /* check format string for allowed specifiers */
 618         for (i = 0; i < fmt_size; i++) {
 619                 /* only printable ascii for now. */
 620                 if ((!isprint(fmt[i]) && !isspace(fmt[i])) || !isascii(fmt[i])) {
 621                         err = -EINVAL;
 622                         goto out;
 623                 }
 624
 625                 if (fmt[i] != '%')
 626                         continue;
 627
 628                 if (fmt[i + 1] == '%') {
 629                         i++;
 630                         continue;
 631                 }
 632
 633                 if (fmt_cnt >= MAX_SEQ_PRINTF_VARARGS) {
 634                         err = -E2BIG;
 635                         goto out;
 636                 }
 637
 638                 if (fmt_cnt >= num_args) {
 639                         err = -EINVAL;
 640                         goto out;
 641                 }
 642
 643                 /* fmt[i] != 0 && fmt[last] == 0, so we can access fmt[i + 1] */
 644                 i++;
 645
 646                 /* skip optional "[0 +-][num]" width formating field */
 647                 while (fmt[i] == '0' || fmt[i] == '+'  || fmt[i] == '-' ||
 648                        fmt[i] == ' ')
 649                         i++;
 650                 if (fmt[i] >= '1' && fmt[i] <= '9') {
 651                         i++;
 652                         while (fmt[i] >= '0' && fmt[i] <= '9')
 653                                 i++;
 654                 }
 655
 656                 if (fmt[i] == 's') {
 657                         void *unsafe_ptr;
 658
 659                         /* try our best to copy */
 660                         if (memcpy_cnt >= MAX_SEQ_PRINTF_MAX_MEMCPY) {
 661                                 err = -E2BIG;
 662                                 goto out;
 663                         }
 664
 665                         unsafe_ptr = (void *)(long)args[fmt_cnt];
 666                         err = strncpy_from_kernel_nofault(bufs->buf[memcpy_cnt],
 667                                         unsafe_ptr, MAX_SEQ_PRINTF_STR_LEN);
 668                         if (err < 0)
 669                                 bufs->buf[memcpy_cnt][0] = '\0';
 670                         params[fmt_cnt] = (u64)(long)bufs->buf[memcpy_cnt];
 671
 672                         fmt_cnt++;
 673                         memcpy_cnt++;
 674                         continue;
 675                 }
 676
 677                 if (fmt[i] == 'p') {
 678                         if (fmt[i + 1] == 0 ||
 679                             fmt[i + 1] == 'K' ||
 680                             fmt[i + 1] == 'x' ||
 681                             fmt[i + 1] == 'B') {
 682                                 /* just kernel pointers */
 683                                 params[fmt_cnt] = args[fmt_cnt];
 684                                 fmt_cnt++;
 685                                 continue;
 686                         }
 687
 688                         /* only support "%pI4", "%pi4", "%pI6" and "%pi6". */
 689                         if (fmt[i + 1] != 'i' && fmt[i + 1] != 'I') {
 690                                 err = -EINVAL;
 691                                 goto out;
 692                         }
 693                         if (fmt[i + 2] != '4' && fmt[i + 2] != '6') {
 694                                 err = -EINVAL;
 695                                 goto out;
 696                         }
 697
 698                         if (memcpy_cnt >= MAX_SEQ_PRINTF_MAX_MEMCPY) {
 699                                 err = -E2BIG;
 700                                 goto out;
 701                         }
 702
 703
 704                         copy_size = (fmt[i + 2] == '4') ? 4 : 16;
 705
 706                         err = copy_from_kernel_nofault(bufs->buf[memcpy_cnt],
 707                                                 (void *) (long) args[fmt_cnt],
 708                                                 copy_size);
 709                         if (err < 0)
 710                                 memset(bufs->buf[memcpy_cnt], 0, copy_size);
 711                         params[fmt_cnt] = (u64)(long)bufs->buf[memcpy_cnt];
 712
 713                         i += 2;
 714                         fmt_cnt++;
 715                         memcpy_cnt++;
 716                         continue;
 717                 }
 718
 719                 if (fmt[i] == 'l') {
 720                         i++;
 721                         if (fmt[i] == 'l')
 722                                 i++;
 723                 }
 724
 725                 if (fmt[i] != 'i' && fmt[i] != 'd' &&
 726                     fmt[i] != 'u' && fmt[i] != 'x' &&
 727                     fmt[i] != 'X') {
 728                         err = -EINVAL;
 729                         goto out;
 730                 }
 731
 732                 params[fmt_cnt] = args[fmt_cnt];
 733                 fmt_cnt++;
 734         }
 735
 736         /* Maximumly we can have MAX_SEQ_PRINTF_VARARGS parameter, just give
 737          * all of them to seq_printf().
 738          */
 739         seq_printf(m, fmt, params[0], params[1], params[2], params[3],
 740                    params[4], params[5], params[6], params[7], params[8],
 741                    params[9], params[10], params[11]);
 742
 743         err = seq_has_overflowed(m) ? -EOVERFLOW : 0;
 744 out:
 745         this_cpu_dec(bpf_seq_printf_buf_used);
 746         return err;
 747 }
 748
 749 BTF_ID_LIST_SINGLE(btf_seq_file_ids, struct, seq_file)
 750
 751 static const struct bpf_func_proto bpf_seq_printf_proto = {
 752         .func           = bpf_seq_printf,
 753         .gpl_only       = true,
 754         .ret_type       = RET_INTEGER,
 755         .arg1_type      = ARG_PTR_TO_BTF_ID,
 756         .arg1_btf_id    = &btf_seq_file_ids[0],
 757         .arg2_type      = ARG_PTR_TO_MEM,
 758         .arg3_type      = ARG_CONST_SIZE,
 759         .arg4_type      = ARG_PTR_TO_MEM_OR_NULL,
 760         .arg5_type      = ARG_CONST_SIZE_OR_ZERO,
 761 };
 762
 763 BPF_CALL_3(bpf_seq_write, struct seq_file *, m, const void *, data, u32, len)
 764 {
 765         return seq_write(m, data, len) ? -EOVERFLOW : 0;
 766 }
 767
 768 static const struct bpf_func_proto bpf_seq_write_proto = {
 769         .func           = bpf_seq_write,
 770         .gpl_only       = true,
 771         .ret_type       = RET_INTEGER,
 772         .arg1_type      = ARG_PTR_TO_BTF_ID,
 773         .arg1_btf_id    = &btf_seq_file_ids[0],
 774         .arg2_type      = ARG_PTR_TO_MEM,
 775         .arg3_type      = ARG_CONST_SIZE_OR_ZERO,
 776 };
 777
 778 BPF_CALL_4(bpf_seq_printf_btf, struct seq_file *, m, struct btf_ptr *, ptr,
 779            u32, btf_ptr_size, u64, flags)
 780 {
 781         const struct btf *btf;
 782         s32 btf_id;
 783         int ret;
 784
 785         ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id);
 786         if (ret)
 787                 return ret;
 788
 789         return btf_type_seq_show_flags(btf, btf_id, ptr->ptr, m, flags);
 790 }
 791
 792 static const struct bpf_func_proto bpf_seq_printf_btf_proto = {
 793         .func           = bpf_seq_printf_btf,
 794         .gpl_only       = true,
 795         .ret_type       = RET_INTEGER,
 796         .arg1_type      = ARG_PTR_TO_BTF_ID,
 797         .arg1_btf_id    = &btf_seq_file_ids[0],
 798         .arg2_type      = ARG_PTR_TO_MEM,
 799         .arg3_type      = ARG_CONST_SIZE_OR_ZERO,
 800         .arg4_type      = ARG_ANYTHING,
 801 };
 802
 803 static __always_inline int
 804 get_map_perf_counter(struct bpf_map *map, u64 flags,
 805                      u64 *value, u64 *enabled, u64 *running)
 806 {
 807         struct bpf_array *array = container_of(map, struct bpf_array, map);
 808         unsigned int cpu = smp_processor_id();
 809         u64 index = flags & BPF_F_INDEX_MASK;
 810         struct bpf_event_entry *ee;
 811
 812         if (unlikely(flags & ~(BPF_F_INDEX_MASK)))
 813                 return -EINVAL;
 814         if (index == BPF_F_CURRENT_CPU)
 815                 index = cpu;
 816         if (unlikely(index >= array->map.max_entries))
 817                 return -E2BIG;
 818
 819         ee = READ_ONCE(array->ptrs[index]);
 820         if (!ee)
 821                 return -ENOENT;
 822
 823         return perf_event_read_local(ee->event, value, enabled, running);
 824 }
 825
 826 BPF_CALL_2(bpf_perf_event_read, struct bpf_map *, map, u64, flags)
 827 {
 828         u64 value = 0;
 829         int err;
 830
 831         err = get_map_perf_counter(map, flags, &value, NULL, NULL);
 832         /*
 833          * this api is ugly since we miss [-22..-2] range of valid
 834          * counter values, but that's uapi
 835          */
 836         if (err)
 837                 return err;
 838         return value;
 839 }
 840
 841 static const struct bpf_func_proto bpf_perf_event_read_proto = {
 842         .func           = bpf_perf_event_read,
 843         .gpl_only       = true,
 844         .ret_type       = RET_INTEGER,
 845         .arg1_type      = ARG_CONST_MAP_PTR,
 846         .arg2_type      = ARG_ANYTHING,
 847 };
 848
 849 BPF_CALL_4(bpf_perf_event_read_value, struct bpf_map *, map, u64, flags,
 850            struct bpf_perf_event_value *, buf, u32, size)
 851 {
 852         int err = -EINVAL;
 853
 854         if (unlikely(size != sizeof(struct bpf_perf_event_value)))
 855                 goto clear;
 856         err = get_map_perf_counter(map, flags, &buf->counter, &buf->enabled,
 857                                    &buf->running);
 858         if (unlikely(err))
 859                 goto clear;
 860         return 0;
 861 clear:
 862         memset(buf, 0, size);
 863         return err;
 864 }
 865
 866 static const struct bpf_func_proto bpf_perf_event_read_value_proto = {
 867         .func           = bpf_perf_event_read_value,
 868         .gpl_only       = true,
 869         .ret_type       = RET_INTEGER,
 870         .arg1_type      = ARG_CONST_MAP_PTR,
 871         .arg2_type      = ARG_ANYTHING,
 872         .arg3_type      = ARG_PTR_TO_UNINIT_MEM,
 873         .arg4_type      = ARG_CONST_SIZE,
 874 };
 875
 876 static __always_inline u64
 877 __bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map,
 878                         u64 flags, struct perf_sample_data *sd)
 879 {
 880         struct bpf_array *array = container_of(map, struct bpf_array, map);
 881         unsigned int cpu = smp_processor_id();
 882         u64 index = flags & BPF_F_INDEX_MASK;
 883         struct bpf_event_entry *ee;
 884         struct perf_event *event;
 885
 886         if (index == BPF_F_CURRENT_CPU)
 887                 index = cpu;
 888         if (unlikely(index >= array->map.max_entries))
 889                 return -E2BIG;
 890
 891         ee = READ_ONCE(array->ptrs[index]);
 892         if (!ee)
 893                 return -ENOENT;
 894
 895         event = ee->event;
 896         if (unlikely(event->attr.type != PERF_TYPE_SOFTWARE ||
 897                      event->attr.config != PERF_COUNT_SW_BPF_OUTPUT))
 898                 return -EINVAL;
 899
 900         if (unlikely(event->oncpu != cpu))
 901                 return -EOPNOTSUPP;
 902
 903         return perf_event_output(event, sd, regs);
 904 }
 905
 906 /*
 907  * Support executing tracepoints in normal, irq, and nmi context that each call
 908  * bpf_perf_event_output
 909  */
 910 struct bpf_trace_sample_data {
 911         struct perf_sample_data sds[3];
 912 };
 913
 914 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_trace_sds);
 915 static DEFINE_PER_CPU(int, bpf_trace_nest_level);
 916 BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map,
 917            u64, flags, void *, data, u64, size)
 918 {
 919         struct bpf_trace_sample_data *sds = this_cpu_ptr(&bpf_trace_sds);
 920         int nest_level = this_cpu_inc_return(bpf_trace_nest_level);
 921         struct perf_raw_record raw = {
 922                 .frag = {
 923                         .size = size,
 924                         .data = data,
 925                 },
 926         };
 927         struct perf_sample_data *sd;
 928         int err;
 929
 930         if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(sds->sds))) {
 931                 err = -EBUSY;
 932                 goto out;
 933         }
 934
 935         sd = &sds->sds[nest_level - 1];
 936
 937         if (unlikely(flags & ~(BPF_F_INDEX_MASK))) {
 938                 err = -EINVAL;
 939                 goto out;
 940         }
 941
 942         perf_sample_data_init(sd, 0, 0);
 943         sd->raw = &raw;
 944
 945         err = __bpf_perf_event_output(regs, map, flags, sd);
 946
 947 out:
 948         this_cpu_dec(bpf_trace_nest_level);
 949         return err;
 950 }
 951
 952 static const struct bpf_func_proto bpf_perf_event_output_proto = {
 953         .func           = bpf_perf_event_output,
 954         .gpl_only       = true,
 955         .ret_type       = RET_INTEGER,
 956         .arg1_type      = ARG_PTR_TO_CTX,
 957         .arg2_type      = ARG_CONST_MAP_PTR,
 958         .arg3_type      = ARG_ANYTHING,
 959         .arg4_type      = ARG_PTR_TO_MEM,
 960         .arg5_type      = ARG_CONST_SIZE_OR_ZERO,
 961 };
 962
 963 static DEFINE_PER_CPU(int, bpf_event_output_nest_level);
 964 struct bpf_nested_pt_regs {
 965         struct pt_regs regs[3];
 966 };
 967 static DEFINE_PER_CPU(struct bpf_nested_pt_regs, bpf_pt_regs);
 968 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_misc_sds);
 969
 970 u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
 971                      void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy)
 972 {
 973         struct perf_raw_frag frag = {
 974                 .copy           = ctx_copy,
 975                 .size           = ctx_size,
 976                 .data           = ctx,
 977         };
 978         struct perf_raw_record raw = {
 979                 .frag = {
 980                         {
 981                                 .next   = ctx_size ? &frag : NULL,
 982                         },
 983                         .size   = meta_size,
 984                         .data   = meta,
 985                 },
 986         };
 987         struct perf_sample_data *sd;
 988         struct pt_regs *regs;
 989         int nest_level;
 990         u64 ret;
 991
 992         preempt_disable();
 993         nest_level = this_cpu_inc_return(bpf_event_output_nest_level);
 994
 995         if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(bpf_misc_sds.sds))) {
 996                 ret = -EBUSY;
 997                 goto out;
 998         }
 999         sd = this_cpu_ptr(&bpf_misc_sds.sds[nest_level - 1]);
1000         regs = this_cpu_ptr(&bpf_pt_regs.regs[nest_level - 1]);
1001
1002         perf_fetch_caller_regs(regs);
1003         perf_sample_data_init(sd, 0, 0);
1004         sd->raw = &raw;
1005
1006         ret = __bpf_perf_event_output(regs, map, flags, sd);
1007 out:
1008         this_cpu_dec(bpf_event_output_nest_level);
1009         preempt_enable();
1010         return ret;
1011 }
1012
1013 BPF_CALL_0(bpf_get_current_task)
1014 {
1015         return (long) current;
1016 }
1017
1018 const struct bpf_func_proto bpf_get_current_task_proto = {
1019         .func           = bpf_get_current_task,
1020         .gpl_only       = true,
1021         .ret_type       = RET_INTEGER,
1022 };
1023
1024 BPF_CALL_2(bpf_current_task_under_cgroup, struct bpf_map *, map, u32, idx)
1025 {
1026         struct bpf_array *array = container_of(map, struct bpf_array, map);
1027         struct cgroup *cgrp;
1028
1029         if (unlikely(idx >= array->map.max_entries))
1030                 return -E2BIG;
1031
1032         cgrp = READ_ONCE(array->ptrs[idx]);
1033         if (unlikely(!cgrp))
1034                 return -EAGAIN;
1035
1036         return task_under_cgroup_hierarchy(current, cgrp);
1037 }
1038
1039 static const struct bpf_func_proto bpf_current_task_under_cgroup_proto = {
1040         .func           = bpf_current_task_under_cgroup,
1041         .gpl_only       = false,
1042         .ret_type       = RET_INTEGER,
1043         .arg1_type      = ARG_CONST_MAP_PTR,
1044         .arg2_type      = ARG_ANYTHING,
1045 };
1046
1047 struct send_signal_irq_work {
1048         struct irq_work irq_work;
1049         struct task_struct *task;
1050         u32 sig;
1051         enum pid_type type;
1052 };
1053
1054 static DEFINE_PER_CPU(struct send_signal_irq_work, send_signal_work);
1055
1056 static void do_bpf_send_signal(struct irq_work *entry)
1057 {
1058         struct send_signal_irq_work *work;
1059
1060         work = container_of(entry, struct send_signal_irq_work, irq_work);
1061         group_send_sig_info(work->sig, SEND_SIG_PRIV, work->task, work->type);
1062         put_task_struct(work->task);
1063 }
1064
1065 static int bpf_send_signal_common(u32 sig, enum pid_type type)
1066 {
1067         struct send_signal_irq_work *work = NULL;
1068
1069         /* Similar to bpf_probe_write_user, task needs to be
1070          * in a sound condition and kernel memory access be
1071          * permitted in order to send signal to the current
1072          * task.
1073          */
1074         if (unlikely(current->flags & (PF_KTHREAD | PF_EXITING)))
1075                 return -EPERM;
1076         if (unlikely(uaccess_kernel()))
1077                 return -EPERM;
1078         if (unlikely(!nmi_uaccess_okay()))
1079                 return -EPERM;
1080         /* Task should not be pid=1 to avoid kernel panic. */
1081         if (unlikely(is_global_init(current)))
1082                 return -EPERM;
1083
1084         if (irqs_disabled()) {
1085                 /* Do an early check on signal validity. Otherwise,
1086                  * the error is lost in deferred irq_work.
1087                  */
1088                 if (unlikely(!valid_signal(sig)))
1089                         return -EINVAL;
1090
1091                 work = this_cpu_ptr(&send_signal_work);
1092                 if (atomic_read(&work->irq_work.flags) & IRQ_WORK_BUSY)
1093                         return -EBUSY;
1094
1095                 /* Add the current task, which is the target of sending signal,
1096                  * to the irq_work. The current task may change when queued
1097                  * irq works get executed.
1098                  */
1099                 work->task = get_task_struct(current);
1100                 work->sig = sig;
1101                 work->type = type;
1102                 irq_work_queue(&work->irq_work);
1103                 return 0;
1104         }
1105
1106         return group_send_sig_info(sig, SEND_SIG_PRIV, current, type);
1107 }
1108
1109 BPF_CALL_1(bpf_send_signal, u32, sig)
1110 {
1111         return bpf_send_signal_common(sig, PIDTYPE_TGID);
1112 }
1113
1114 static const struct bpf_func_proto bpf_send_signal_proto = {
1115         .func           = bpf_send_signal,
1116         .gpl_only       = false,
1117         .ret_type       = RET_INTEGER,
1118         .arg1_type      = ARG_ANYTHING,
1119 };
1120
1121 BPF_CALL_1(bpf_send_signal_thread, u32, sig)
1122 {
1123         return bpf_send_signal_common(sig, PIDTYPE_PID);
1124 }
1125
1126 static const struct bpf_func_proto bpf_send_signal_thread_proto = {
1127         .func           = bpf_send_signal_thread,
1128         .gpl_only       = false,
1129         .ret_type       = RET_INTEGER,
1130         .arg1_type      = ARG_ANYTHING,
1131 };
1132
1133 BPF_CALL_3(bpf_d_path, struct path *, path, char *, buf, u32, sz)
1134 {
1135         struct path copy;
1136         long len;
1137         char *p;
1138
1139         if (!sz)
1140                 return 0;
1141
1142         /*
1143          * The path pointer is verified as trusted and safe to use,
1144          * but let's double check it's valid anyway to workaround
1145          * potentially broken verifier.
1146          */
1147         len = copy_from_kernel_nofault(&copy, path, sizeof(*path));
1148         if (len < 0)
1149                 return len;
1150
1151         p = d_path(&copy, buf, sz);
1152         if (IS_ERR(p)) {
1153                 len = PTR_ERR(p);
1154         } else {
1155                 len = buf + sz - p;
1156                 memmove(buf, p, len);
1157         }
1158
1159         return len;
1160 }
1161
1162 BTF_SET_START(btf_allowlist_d_path)
1163 #ifdef CONFIG_SECURITY
1164 BTF_ID(func, security_file_permission)
1165 BTF_ID(func, security_inode_getattr)
1166 BTF_ID(func, security_file_open)
1167 #endif
1168 #ifdef CONFIG_SECURITY_PATH
1169 BTF_ID(func, security_path_truncate)
1170 #endif
1171 BTF_ID(func, vfs_truncate)
1172 BTF_ID(func, vfs_fallocate)
1173 BTF_ID(func, dentry_open)
1174 BTF_ID(func, vfs_getattr)
1175 BTF_ID(func, filp_close)
1176 BTF_SET_END(btf_allowlist_d_path)
1177
1178 static bool bpf_d_path_allowed(const struct bpf_prog *prog)
1179 {
1180         return btf_id_set_contains(&btf_allowlist_d_path, prog->aux->attach_btf_id);
1181 }
1182
1183 BTF_ID_LIST_SINGLE(bpf_d_path_btf_ids, struct, path)
1184
1185 static const struct bpf_func_proto bpf_d_path_proto = {
1186         .func           = bpf_d_path,
1187         .gpl_only       = false,
1188         .ret_type       = RET_INTEGER,
1189         .arg1_type      = ARG_PTR_TO_BTF_ID,
1190         .arg1_btf_id    = &bpf_d_path_btf_ids[0],
1191         .arg2_type      = ARG_PTR_TO_MEM,
1192         .arg3_type      = ARG_CONST_SIZE_OR_ZERO,
1193         .allowed        = bpf_d_path_allowed,
1194 };
1195
1196 #define BTF_F_ALL       (BTF_F_COMPACT  | BTF_F_NONAME | \
1197                          BTF_F_PTR_RAW | BTF_F_ZERO)
1198
1199 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size,
1200                                   u64 flags, const struct btf **btf,
1201                                   s32 *btf_id)
1202 {
1203         const struct btf_type *t;
1204
1205         if (unlikely(flags & ~(BTF_F_ALL)))
1206                 return -EINVAL;
1207
1208         if (btf_ptr_size != sizeof(struct btf_ptr))
1209                 return -EINVAL;
1210
1211         *btf = bpf_get_btf_vmlinux();
1212
1213         if (IS_ERR_OR_NULL(*btf))
1214                 return IS_ERR(*btf) ? PTR_ERR(*btf) : -EINVAL;
1215
1216         if (ptr->type_id > 0)
1217                 *btf_id = ptr->type_id;
1218         else
1219                 return -EINVAL;
1220
1221         if (*btf_id > 0)
1222                 t = btf_type_by_id(*btf, *btf_id);
1223         if (*btf_id <= 0 || !t)
1224                 return -ENOENT;
1225
1226         return 0;
1227 }
1228
1229 BPF_CALL_5(bpf_snprintf_btf, char *, str, u32, str_size, struct btf_ptr *, ptr,
1230            u32, btf_ptr_size, u64, flags)
1231 {
1232         const struct btf *btf;
1233         s32 btf_id;
1234         int ret;
1235
1236         ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id);
1237         if (ret)
1238                 return ret;
1239
1240         return btf_type_snprintf_show(btf, btf_id, ptr->ptr, str, str_size,
1241                                       flags);
1242 }
1243
1244 const struct bpf_func_proto bpf_snprintf_btf_proto = {
1245         .func           = bpf_snprintf_btf,
1246         .gpl_only       = false,
1247         .ret_type       = RET_INTEGER,
1248         .arg1_type      = ARG_PTR_TO_MEM,
1249         .arg2_type      = ARG_CONST_SIZE,
1250         .arg3_type      = ARG_PTR_TO_MEM,
1251         .arg4_type      = ARG_CONST_SIZE,
1252         .arg5_type      = ARG_ANYTHING,
1253 };
1254
1255 const struct bpf_func_proto *
1256 bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1257 {
1258         switch (func_id) {
1259         case BPF_FUNC_map_lookup_elem:
1260                 return &bpf_map_lookup_elem_proto;
1261         case BPF_FUNC_map_update_elem:
1262                 return &bpf_map_update_elem_proto;
1263         case BPF_FUNC_map_delete_elem:
1264                 return &bpf_map_delete_elem_proto;
1265         case BPF_FUNC_map_push_elem:
1266                 return &bpf_map_push_elem_proto;
1267         case BPF_FUNC_map_pop_elem:
1268                 return &bpf_map_pop_elem_proto;
1269         case BPF_FUNC_map_peek_elem:
1270                 return &bpf_map_peek_elem_proto;
1271         case BPF_FUNC_ktime_get_ns:
1272                 return &bpf_ktime_get_ns_proto;
1273         case BPF_FUNC_ktime_get_boot_ns:
1274                 return &bpf_ktime_get_boot_ns_proto;
1275         case BPF_FUNC_tail_call:
1276                 return &bpf_tail_call_proto;
1277         case BPF_FUNC_get_current_pid_tgid:
1278                 return &bpf_get_current_pid_tgid_proto;
1279         case BPF_FUNC_get_current_task:
1280                 return &bpf_get_current_task_proto;
1281         case BPF_FUNC_get_current_uid_gid:
1282                 return &bpf_get_current_uid_gid_proto;
1283         case BPF_FUNC_get_current_comm:
1284                 return &bpf_get_current_comm_proto;
1285         case BPF_FUNC_trace_printk:
1286                 return bpf_get_trace_printk_proto();
1287         case BPF_FUNC_get_smp_processor_id:
1288                 return &bpf_get_smp_processor_id_proto;
1289         case BPF_FUNC_get_numa_node_id:
1290                 return &bpf_get_numa_node_id_proto;
1291         case BPF_FUNC_perf_event_read:
1292                 return &bpf_perf_event_read_proto;
1293         case BPF_FUNC_current_task_under_cgroup:
1294                 return &bpf_current_task_under_cgroup_proto;
1295         case BPF_FUNC_get_prandom_u32:
1296                 return &bpf_get_prandom_u32_proto;
1297         case BPF_FUNC_probe_write_user:
1298                 return security_locked_down(LOCKDOWN_BPF_WRITE_USER) < 0 ?
1299                        NULL : bpf_get_probe_write_proto();
1300         case BPF_FUNC_probe_read_user:
1301                 return &bpf_probe_read_user_proto;
1302         case BPF_FUNC_probe_read_kernel:
1303                 return security_locked_down(LOCKDOWN_BPF_READ) < 0 ?
1304                        NULL : &bpf_probe_read_kernel_proto;
1305         case BPF_FUNC_probe_read_user_str:
1306                 return &bpf_probe_read_user_str_proto;
1307         case BPF_FUNC_probe_read_kernel_str:
1308                 return security_locked_down(LOCKDOWN_BPF_READ) < 0 ?
1309                        NULL : &bpf_probe_read_kernel_str_proto;
1310 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
1311         case BPF_FUNC_probe_read:
1312                 return security_locked_down(LOCKDOWN_BPF_READ) < 0 ?
1313                        NULL : &bpf_probe_read_compat_proto;
1314         case BPF_FUNC_probe_read_str:
1315                 return security_locked_down(LOCKDOWN_BPF_READ) < 0 ?
1316                        NULL : &bpf_probe_read_compat_str_proto;
1317 #endif
1318 #ifdef CONFIG_CGROUPS
1319         case BPF_FUNC_get_current_cgroup_id:
1320                 return &bpf_get_current_cgroup_id_proto;
1321 #endif
1322         case BPF_FUNC_send_signal:
1323                 return &bpf_send_signal_proto;
1324         case BPF_FUNC_send_signal_thread:
1325                 return &bpf_send_signal_thread_proto;
1326         case BPF_FUNC_perf_event_read_value:
1327                 return &bpf_perf_event_read_value_proto;
1328         case BPF_FUNC_get_ns_current_pid_tgid:
1329                 return &bpf_get_ns_current_pid_tgid_proto;
1330         case BPF_FUNC_ringbuf_output:
1331                 return &bpf_ringbuf_output_proto;
1332         case BPF_FUNC_ringbuf_reserve:
1333                 return &bpf_ringbuf_reserve_proto;
1334         case BPF_FUNC_ringbuf_submit:
1335                 return &bpf_ringbuf_submit_proto;
1336         case BPF_FUNC_ringbuf_discard:
1337                 return &bpf_ringbuf_discard_proto;
1338         case BPF_FUNC_ringbuf_query:
1339                 return &bpf_ringbuf_query_proto;
1340         case BPF_FUNC_jiffies64:
1341                 return &bpf_jiffies64_proto;
1342         case BPF_FUNC_get_task_stack:
1343                 return &bpf_get_task_stack_proto;
1344         case BPF_FUNC_copy_from_user:
1345                 return prog->aux->sleepable ? &bpf_copy_from_user_proto : NULL;
1346         case BPF_FUNC_snprintf_btf:
1347                 return &bpf_snprintf_btf_proto;
1348         case BPF_FUNC_per_cpu_ptr:
1349                 return &bpf_per_cpu_ptr_proto;
1350         case BPF_FUNC_this_cpu_ptr:
1351                 return &bpf_this_cpu_ptr_proto;
1352         default:
1353                 return NULL;
1354         }
1355 }
1356
1357 static const struct bpf_func_proto *
1358 kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1359 {
1360         switch (func_id) {
1361         case BPF_FUNC_perf_event_output:
1362                 return &bpf_perf_event_output_proto;
1363         case BPF_FUNC_get_stackid:
1364                 return &bpf_get_stackid_proto;
1365         case BPF_FUNC_get_stack:
1366                 return &bpf_get_stack_proto;
1367 #ifdef CONFIG_BPF_KPROBE_OVERRIDE
1368         case BPF_FUNC_override_return:
1369                 return &bpf_override_return_proto;
1370 #endif
1371         default:
1372                 return bpf_tracing_func_proto(func_id, prog);
1373         }
1374 }
1375
1376 /* bpf+kprobe programs can access fields of 'struct pt_regs' */
1377 static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
1378                                         const struct bpf_prog *prog,
1379                                         struct bpf_insn_access_aux *info)
1380 {
1381         if (off < 0 || off >= sizeof(struct pt_regs))
1382                 return false;
1383         if (type != BPF_READ)
1384                 return false;
1385         if (off % size != 0)
1386                 return false;
1387         /*
1388          * Assertion for 32 bit to make sure last 8 byte access
1389          * (BPF_DW) to the last 4 byte member is disallowed.
1390          */
1391         if (off + size > sizeof(struct pt_regs))
1392                 return false;
1393
1394         return true;
1395 }
1396
1397 const struct bpf_verifier_ops kprobe_verifier_ops = {
1398         .get_func_proto  = kprobe_prog_func_proto,
1399         .is_valid_access = kprobe_prog_is_valid_access,
1400 };
1401
1402 const struct bpf_prog_ops kprobe_prog_ops = {
1403 };
1404
1405 BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map,
1406            u64, flags, void *, data, u64, size)
1407 {
1408         struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1409
1410         /*
1411          * r1 points to perf tracepoint buffer where first 8 bytes are hidden
1412          * from bpf program and contain a pointer to 'struct pt_regs'. Fetch it
1413          * from there and call the same bpf_perf_event_output() helper inline.
1414          */
1415         return ____bpf_perf_event_output(regs, map, flags, data, size);
1416 }
1417
1418 static const struct bpf_func_proto bpf_perf_event_output_proto_tp = {
1419         .func           = bpf_perf_event_output_tp,
1420         .gpl_only       = true,
1421         .ret_type       = RET_INTEGER,
1422         .arg1_type      = ARG_PTR_TO_CTX,
1423         .arg2_type      = ARG_CONST_MAP_PTR,
1424         .arg3_type      = ARG_ANYTHING,
1425         .arg4_type      = ARG_PTR_TO_MEM,
1426         .arg5_type      = ARG_CONST_SIZE_OR_ZERO,
1427 };
1428
1429 BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map,
1430            u64, flags)
1431 {
1432         struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1433
1434         /*
1435          * Same comment as in bpf_perf_event_output_tp(), only that this time
1436          * the other helper's function body cannot be inlined due to being
1437          * external, thus we need to call raw helper function.
1438          */
1439         return bpf_get_stackid((unsigned long) regs, (unsigned long) map,
1440                                flags, 0, 0);
1441 }
1442
1443 static const struct bpf_func_proto bpf_get_stackid_proto_tp = {
1444         .func           = bpf_get_stackid_tp,
1445         .gpl_only       = true,
1446         .ret_type       = RET_INTEGER,
1447         .arg1_type      = ARG_PTR_TO_CTX,
1448         .arg2_type      = ARG_CONST_MAP_PTR,
1449         .arg3_type      = ARG_ANYTHING,
1450 };
1451
1452 BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size,
1453            u64, flags)
1454 {
1455         struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1456
1457         return bpf_get_stack((unsigned long) regs, (unsigned long) buf,
1458                              (unsigned long) size, flags, 0);
1459 }
1460
1461 static const struct bpf_func_proto bpf_get_stack_proto_tp = {
1462         .func           = bpf_get_stack_tp,
1463         .gpl_only       = true,
1464         .ret_type       = RET_INTEGER,
1465         .arg1_type      = ARG_PTR_TO_CTX,
1466         .arg2_type      = ARG_PTR_TO_UNINIT_MEM,
1467         .arg3_type      = ARG_CONST_SIZE_OR_ZERO,
1468         .arg4_type      = ARG_ANYTHING,
1469 };
1470
1471 static const struct bpf_func_proto *
1472 tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1473 {
1474         switch (func_id) {
1475         case BPF_FUNC_perf_event_output:
1476                 return &bpf_perf_event_output_proto_tp;
1477         case BPF_FUNC_get_stackid:
1478                 return &bpf_get_stackid_proto_tp;
1479         case BPF_FUNC_get_stack:
1480                 return &bpf_get_stack_proto_tp;
1481         default:
1482                 return bpf_tracing_func_proto(func_id, prog);
1483         }
1484 }
1485
1486 static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type,
1487                                     const struct bpf_prog *prog,
1488                                     struct bpf_insn_access_aux *info)
1489 {
1490         if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE)
1491                 return false;
1492         if (type != BPF_READ)
1493                 return false;
1494         if (off % size != 0)
1495                 return false;
1496
1497         BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(__u64));
1498         return true;
1499 }
1500
1501 const struct bpf_verifier_ops tracepoint_verifier_ops = {
1502         .get_func_proto  = tp_prog_func_proto,
1503         .is_valid_access = tp_prog_is_valid_access,
1504 };
1505
1506 const struct bpf_prog_ops tracepoint_prog_ops = {
1507 };
1508
1509 BPF_CALL_3(bpf_perf_prog_read_value, struct bpf_perf_event_data_kern *, ctx,
1510            struct bpf_perf_event_value *, buf, u32, size)
1511 {
1512         int err = -EINVAL;
1513
1514         if (unlikely(size != sizeof(struct bpf_perf_event_value)))
1515                 goto clear;
1516         err = perf_event_read_local(ctx->event, &buf->counter, &buf->enabled,
1517                                     &buf->running);
1518         if (unlikely(err))
1519                 goto clear;
1520         return 0;
1521 clear:
1522         memset(buf, 0, size);
1523         return err;
1524 }
1525
1526 static const struct bpf_func_proto bpf_perf_prog_read_value_proto = {
1527          .func           = bpf_perf_prog_read_value,
1528          .gpl_only       = true,
1529          .ret_type       = RET_INTEGER,
1530          .arg1_type      = ARG_PTR_TO_CTX,
1531          .arg2_type      = ARG_PTR_TO_UNINIT_MEM,
1532          .arg3_type      = ARG_CONST_SIZE,
1533 };
1534
1535 BPF_CALL_4(bpf_read_branch_records, struct bpf_perf_event_data_kern *, ctx,
1536            void *, buf, u32, size, u64, flags)
1537 {
1538         static const u32 br_entry_size = sizeof(struct perf_branch_entry);
1539         struct perf_branch_stack *br_stack = ctx->data->br_stack;
1540         u32 to_copy;
1541
1542         if (unlikely(flags & ~BPF_F_GET_BRANCH_RECORDS_SIZE))
1543                 return -EINVAL;
1544
1545         if (unlikely(!br_stack))
1546                 return -ENOENT;
1547
1548         if (flags & BPF_F_GET_BRANCH_RECORDS_SIZE)
1549                 return br_stack->nr * br_entry_size;
1550
1551         if (!buf || (size % br_entry_size != 0))
1552                 return -EINVAL;
1553
1554         to_copy = min_t(u32, br_stack->nr * br_entry_size, size);
1555         memcpy(buf, br_stack->entries, to_copy);
1556
1557         return to_copy;
1558 }
1559
1560 static const struct bpf_func_proto bpf_read_branch_records_proto = {
1561         .func           = bpf_read_branch_records,
1562         .gpl_only       = true,
1563         .ret_type       = RET_INTEGER,
1564         .arg1_type      = ARG_PTR_TO_CTX,
1565         .arg2_type      = ARG_PTR_TO_MEM_OR_NULL,
1566         .arg3_type      = ARG_CONST_SIZE_OR_ZERO,
1567         .arg4_type      = ARG_ANYTHING,
1568 };
1569
1570 static const struct bpf_func_proto *
1571 pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1572 {
1573         switch (func_id) {
1574         case BPF_FUNC_perf_event_output:
1575                 return &bpf_perf_event_output_proto_tp;
1576         case BPF_FUNC_get_stackid:
1577                 return &bpf_get_stackid_proto_pe;
1578         case BPF_FUNC_get_stack:
1579                 return &bpf_get_stack_proto_pe;
1580         case BPF_FUNC_perf_prog_read_value:
1581                 return &bpf_perf_prog_read_value_proto;
1582         case BPF_FUNC_read_branch_records:
1583                 return &bpf_read_branch_records_proto;
1584         default:
1585                 return bpf_tracing_func_proto(func_id, prog);
1586         }
1587 }
1588
1589 /*
1590  * bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp
1591  * to avoid potential recursive reuse issue when/if tracepoints are added
1592  * inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack.
1593  *
1594  * Since raw tracepoints run despite bpf_prog_active, support concurrent usage
1595  * in normal, irq, and nmi context.
1596  */
1597 struct bpf_raw_tp_regs {
1598         struct pt_regs regs[3];
1599 };
1600 static DEFINE_PER_CPU(struct bpf_raw_tp_regs, bpf_raw_tp_regs);
1601 static DEFINE_PER_CPU(int, bpf_raw_tp_nest_level);
1602 static struct pt_regs *get_bpf_raw_tp_regs(void)
1603 {
1604         struct bpf_raw_tp_regs *tp_regs = this_cpu_ptr(&bpf_raw_tp_regs);
1605         int nest_level = this_cpu_inc_return(bpf_raw_tp_nest_level);
1606
1607         if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(tp_regs->regs))) {
1608                 this_cpu_dec(bpf_raw_tp_nest_level);
1609                 return ERR_PTR(-EBUSY);
1610         }
1611
1612         return &tp_regs->regs[nest_level - 1];
1613 }
1614
1615 static void put_bpf_raw_tp_regs(void)
1616 {
1617         this_cpu_dec(bpf_raw_tp_nest_level);
1618 }
1619
1620 BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args,
1621            struct bpf_map *, map, u64, flags, void *, data, u64, size)
1622 {
1623         struct pt_regs *regs = get_bpf_raw_tp_regs();
1624         int ret;
1625
1626         if (IS_ERR(regs))
1627                 return PTR_ERR(regs);
1628
1629         perf_fetch_caller_regs(regs);
1630         ret = ____bpf_perf_event_output(regs, map, flags, data, size);
1631
1632         put_bpf_raw_tp_regs();
1633         return ret;
1634 }
1635
1636 static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = {
1637         .func           = bpf_perf_event_output_raw_tp,
1638         .gpl_only       = true,
1639         .ret_type       = RET_INTEGER,
1640         .arg1_type      = ARG_PTR_TO_CTX,
1641         .arg2_type      = ARG_CONST_MAP_PTR,
1642         .arg3_type      = ARG_ANYTHING,
1643         .arg4_type      = ARG_PTR_TO_MEM,
1644         .arg5_type      = ARG_CONST_SIZE_OR_ZERO,
1645 };
1646
1647 extern const struct bpf_func_proto bpf_skb_output_proto;
1648 extern const struct bpf_func_proto bpf_xdp_output_proto;
1649
1650 BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args,
1651            struct bpf_map *, map, u64, flags)
1652 {
1653         struct pt_regs *regs = get_bpf_raw_tp_regs();
1654         int ret;
1655
1656         if (IS_ERR(regs))
1657                 return PTR_ERR(regs);
1658
1659         perf_fetch_caller_regs(regs);
1660         /* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */
1661         ret = bpf_get_stackid((unsigned long) regs, (unsigned long) map,
1662                               flags, 0, 0);
1663         put_bpf_raw_tp_regs();
1664         return ret;
1665 }
1666
1667 static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = {
1668         .func           = bpf_get_stackid_raw_tp,
1669         .gpl_only       = true,
1670         .ret_type       = RET_INTEGER,
1671         .arg1_type      = ARG_PTR_TO_CTX,
1672         .arg2_type      = ARG_CONST_MAP_PTR,
1673         .arg3_type      = ARG_ANYTHING,
1674 };
1675
1676 BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args,
1677            void *, buf, u32, size, u64, flags)
1678 {
1679         struct pt_regs *regs = get_bpf_raw_tp_regs();
1680         int ret;
1681
1682         if (IS_ERR(regs))
1683                 return PTR_ERR(regs);
1684
1685         perf_fetch_caller_regs(regs);
1686         ret = bpf_get_stack((unsigned long) regs, (unsigned long) buf,
1687                             (unsigned long) size, flags, 0);
1688         put_bpf_raw_tp_regs();
1689         return ret;
1690 }
1691
1692 static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = {
1693         .func           = bpf_get_stack_raw_tp,
1694         .gpl_only       = true,
1695         .ret_type       = RET_INTEGER,
1696         .arg1_type      = ARG_PTR_TO_CTX,
1697         .arg2_type      = ARG_PTR_TO_MEM,
1698         .arg3_type      = ARG_CONST_SIZE_OR_ZERO,
1699         .arg4_type      = ARG_ANYTHING,
1700 };
1701
1702 static const struct bpf_func_proto *
1703 raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1704 {
1705         switch (func_id) {
1706         case BPF_FUNC_perf_event_output:
1707                 return &bpf_perf_event_output_proto_raw_tp;
1708         case BPF_FUNC_get_stackid:
1709                 return &bpf_get_stackid_proto_raw_tp;
1710         case BPF_FUNC_get_stack:
1711                 return &bpf_get_stack_proto_raw_tp;
1712         default:
1713                 return bpf_tracing_func_proto(func_id, prog);
1714         }
1715 }
1716
1717 const struct bpf_func_proto *
1718 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1719 {
1720         switch (func_id) {
1721 #ifdef CONFIG_NET
1722         case BPF_FUNC_skb_output:
1723                 return &bpf_skb_output_proto;
1724         case BPF_FUNC_xdp_output:
1725                 return &bpf_xdp_output_proto;
1726         case BPF_FUNC_skc_to_tcp6_sock:
1727                 return &bpf_skc_to_tcp6_sock_proto;
1728         case BPF_FUNC_skc_to_tcp_sock:
1729                 return &bpf_skc_to_tcp_sock_proto;
1730         case BPF_FUNC_skc_to_tcp_timewait_sock:
1731                 return &bpf_skc_to_tcp_timewait_sock_proto;
1732         case BPF_FUNC_skc_to_tcp_request_sock:
1733                 return &bpf_skc_to_tcp_request_sock_proto;
1734         case BPF_FUNC_skc_to_udp6_sock:
1735                 return &bpf_skc_to_udp6_sock_proto;
1736 #endif
1737         case BPF_FUNC_seq_printf:
1738                 return prog->expected_attach_type == BPF_TRACE_ITER ?
1739                        &bpf_seq_printf_proto :
1740                        NULL;
1741         case BPF_FUNC_seq_write:
1742                 return prog->expected_attach_type == BPF_TRACE_ITER ?
1743                        &bpf_seq_write_proto :
1744                        NULL;
1745         case BPF_FUNC_seq_printf_btf:
1746                 return prog->expected_attach_type == BPF_TRACE_ITER ?
1747                        &bpf_seq_printf_btf_proto :
1748                        NULL;
1749         case BPF_FUNC_d_path:
1750                 return &bpf_d_path_proto;
1751         default:
1752                 return raw_tp_prog_func_proto(func_id, prog);
1753         }
1754 }
1755
1756 static bool raw_tp_prog_is_valid_access(int off, int size,
1757                                         enum bpf_access_type type,
1758                                         const struct bpf_prog *prog,
1759                                         struct bpf_insn_access_aux *info)
1760 {
1761         if (off < 0 || off >= sizeof(__u64) * MAX_BPF_FUNC_ARGS)
1762                 return false;
1763         if (type != BPF_READ)
1764                 return false;
1765         if (off % size != 0)
1766                 return false;
1767         return true;
1768 }
1769
1770 static bool tracing_prog_is_valid_access(int off, int size,
1771                                          enum bpf_access_type type,
1772                                          const struct bpf_prog *prog,
1773                                          struct bpf_insn_access_aux *info)
1774 {
1775         if (off < 0 || off >= sizeof(__u64) * MAX_BPF_FUNC_ARGS)
1776                 return false;
1777         if (type != BPF_READ)
1778                 return false;
1779         if (off % size != 0)
1780                 return false;
1781         return btf_ctx_access(off, size, type, prog, info);
1782 }
1783
1784 int __weak bpf_prog_test_run_tracing(struct bpf_prog *prog,
1785                                      const union bpf_attr *kattr,
1786                                      union bpf_attr __user *uattr)
1787 {
1788         return -ENOTSUPP;
1789 }
1790
1791 const struct bpf_verifier_ops raw_tracepoint_verifier_ops = {
1792         .get_func_proto  = raw_tp_prog_func_proto,
1793         .is_valid_access = raw_tp_prog_is_valid_access,
1794 };
1795
1796 const struct bpf_prog_ops raw_tracepoint_prog_ops = {
1797 #ifdef CONFIG_NET
1798         .test_run = bpf_prog_test_run_raw_tp,
1799 #endif
1800 };
1801
1802 const struct bpf_verifier_ops tracing_verifier_ops = {
1803         .get_func_proto  = tracing_prog_func_proto,
1804         .is_valid_access = tracing_prog_is_valid_access,
1805 };
1806
1807 const struct bpf_prog_ops tracing_prog_ops = {
1808         .test_run = bpf_prog_test_run_tracing,
1809 };
1810
1811 static bool raw_tp_writable_prog_is_valid_access(int off, int size,
1812                                                  enum bpf_access_type type,
1813                                                  const struct bpf_prog *prog,
1814                                                  struct bpf_insn_access_aux *info)
1815 {
1816         if (off == 0) {
1817                 if (size != sizeof(u64) || type != BPF_READ)
1818                         return false;
1819                 info->reg_type = PTR_TO_TP_BUFFER;
1820         }
1821         return raw_tp_prog_is_valid_access(off, size, type, prog, info);
1822 }
1823
1824 const struct bpf_verifier_ops raw_tracepoint_writable_verifier_ops = {
1825         .get_func_proto  = raw_tp_prog_func_proto,
1826         .is_valid_access = raw_tp_writable_prog_is_valid_access,
1827 };
1828
1829 const struct bpf_prog_ops raw_tracepoint_writable_prog_ops = {
1830 };
1831
1832 static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
1833                                     const struct bpf_prog *prog,
1834                                     struct bpf_insn_access_aux *info)
1835 {
1836         const int size_u64 = sizeof(u64);
1837
1838         if (off < 0 || off >= sizeof(struct bpf_perf_event_data))
1839                 return false;
1840         if (type != BPF_READ)
1841                 return false;
1842         if (off % size != 0) {
1843                 if (sizeof(unsigned long) != 4)
1844                         return false;
1845                 if (size != 8)
1846                         return false;
1847                 if (off % size != 4)
1848                         return false;
1849         }
1850
1851         switch (off) {
1852         case bpf_ctx_range(struct bpf_perf_event_data, sample_period):
1853                 bpf_ctx_record_field_size(info, size_u64);
1854                 if (!bpf_ctx_narrow_access_ok(off, size, size_u64))
1855                         return false;
1856                 break;
1857         case bpf_ctx_range(struct bpf_perf_event_data, addr):
1858                 bpf_ctx_record_field_size(info, size_u64);
1859                 if (!bpf_ctx_narrow_access_ok(off, size, size_u64))
1860                         return false;
1861                 break;
1862         default:
1863                 if (size != sizeof(long))
1864                         return false;
1865         }
1866
1867         return true;
1868 }
1869
1870 static u32 pe_prog_convert_ctx_access(enum bpf_access_type type,
1871                                       const struct bpf_insn *si,
1872                                       struct bpf_insn *insn_buf,
1873                                       struct bpf_prog *prog, u32 *target_size)
1874 {
1875         struct bpf_insn *insn = insn_buf;
1876
1877         switch (si->off) {
1878         case offsetof(struct bpf_perf_event_data, sample_period):
1879                 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
1880                                                        data), si->dst_reg, si->src_reg,
1881                                       offsetof(struct bpf_perf_event_data_kern, data));
1882                 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg,
1883                                       bpf_target_off(struct perf_sample_data, period, 8,
1884                                                      target_size));
1885                 break;
1886         case offsetof(struct bpf_perf_event_data, addr):
1887                 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
1888                                                        data), si->dst_reg, si->src_reg,
1889                                       offsetof(struct bpf_perf_event_data_kern, data));
1890                 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg,
1891                                       bpf_target_off(struct perf_sample_data, addr, 8,
1892                                                      target_size));
1893                 break;
1894         default:
1895                 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
1896                                                        regs), si->dst_reg, si->src_reg,
1897                                       offsetof(struct bpf_perf_event_data_kern, regs));
1898                 *insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg,
1899                                       si->off);
1900                 break;
1901         }
1902
1903         return insn - insn_buf;
1904 }
1905
1906 const struct bpf_verifier_ops perf_event_verifier_ops = {
1907         .get_func_proto         = pe_prog_func_proto,
1908         .is_valid_access        = pe_prog_is_valid_access,
1909         .convert_ctx_access     = pe_prog_convert_ctx_access,
1910 };
1911
1912 const struct bpf_prog_ops perf_event_prog_ops = {
1913 };
1914
1915 static DEFINE_MUTEX(bpf_event_mutex);
1916
1917 #define BPF_TRACE_MAX_PROGS 64
1918
1919 int perf_event_attach_bpf_prog(struct perf_event *event,
1920                                struct bpf_prog *prog)
1921 {
1922         struct bpf_prog_array *old_array;
1923         struct bpf_prog_array *new_array;
1924         int ret = -EEXIST;
1925
1926         /*
1927          * Kprobe override only works if they are on the function entry,
1928          * and only if they are on the opt-in list.
1929          */
1930         if (prog->kprobe_override &&
1931             (!trace_kprobe_on_func_entry(event->tp_event) ||
1932              !trace_kprobe_error_injectable(event->tp_event)))
1933                 return -EINVAL;
1934
1935         mutex_lock(&bpf_event_mutex);
1936
1937         if (event->prog)
1938                 goto unlock;
1939
1940         old_array = bpf_event_rcu_dereference(event->tp_event->prog_array);
1941         if (old_array &&
1942             bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) {
1943                 ret = -E2BIG;
1944                 goto unlock;
1945         }
1946
1947         ret = bpf_prog_array_copy(old_array, NULL, prog, &new_array);
1948         if (ret < 0)
1949                 goto unlock;
1950
1951         /* set the new array to event->tp_event and set event->prog */
1952         event->prog = prog;
1953         rcu_assign_pointer(event->tp_event->prog_array, new_array);
1954         bpf_prog_array_free(old_array);
1955
1956 unlock:
1957         mutex_unlock(&bpf_event_mutex);
1958         return ret;
1959 }
1960
1961 void perf_event_detach_bpf_prog(struct perf_event *event)
1962 {
1963         struct bpf_prog_array *old_array;
1964         struct bpf_prog_array *new_array;
1965         int ret;
1966
1967         mutex_lock(&bpf_event_mutex);
1968
1969         if (!event->prog)
1970                 goto unlock;
1971
1972         old_array = bpf_event_rcu_dereference(event->tp_event->prog_array);
1973         ret = bpf_prog_array_copy(old_array, event->prog, NULL, &new_array);
1974         if (ret == -ENOENT)
1975                 goto unlock;
1976         if (ret < 0) {
1977                 bpf_prog_array_delete_safe(old_array, event->prog);
1978         } else {
1979                 rcu_assign_pointer(event->tp_event->prog_array, new_array);
1980                 bpf_prog_array_free(old_array);
1981         }
1982
1983         bpf_prog_put(event->prog);
1984         event->prog = NULL;
1985
1986 unlock:
1987         mutex_unlock(&bpf_event_mutex);
1988 }
1989
1990 int perf_event_query_prog_array(struct perf_event *event, void __user *info)
1991 {
1992         struct perf_event_query_bpf __user *uquery = info;
1993         struct perf_event_query_bpf query = {};
1994         struct bpf_prog_array *progs;
1995         u32 *ids, prog_cnt, ids_len;
1996         int ret;
1997
1998         if (!perfmon_capable())
1999                 return -EPERM;
2000         if (event->attr.type != PERF_TYPE_TRACEPOINT)
2001                 return -EINVAL;
2002         if (copy_from_user(&query, uquery, sizeof(query)))
2003                 return -EFAULT;
2004
2005         ids_len = query.ids_len;
2006         if (ids_len > BPF_TRACE_MAX_PROGS)
2007                 return -E2BIG;
2008         ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN);
2009         if (!ids)
2010                 return -ENOMEM;
2011         /*
2012          * The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which
2013          * is required when user only wants to check for uquery->prog_cnt.
2014          * There is no need to check for it since the case is handled
2015          * gracefully in bpf_prog_array_copy_info.
2016          */
2017
2018         mutex_lock(&bpf_event_mutex);
2019         progs = bpf_event_rcu_dereference(event->tp_event->prog_array);
2020         ret = bpf_prog_array_copy_info(progs, ids, ids_len, &prog_cnt);
2021         mutex_unlock(&bpf_event_mutex);
2022
2023         if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) ||
2024             copy_to_user(uquery->ids, ids, ids_len * sizeof(u32)))
2025                 ret = -EFAULT;
2026
2027         kfree(ids);
2028         return ret;
2029 }
2030
2031 extern struct bpf_raw_event_map __start__bpf_raw_tp[];
2032 extern struct bpf_raw_event_map __stop__bpf_raw_tp[];
2033
2034 struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name)
2035 {
2036         struct bpf_raw_event_map *btp = __start__bpf_raw_tp;
2037
2038         for (; btp < __stop__bpf_raw_tp; btp++) {
2039                 if (!strcmp(btp->tp->name, name))
2040                         return btp;
2041         }
2042
2043         return bpf_get_raw_tracepoint_module(name);
2044 }
2045
2046 void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp)
2047 {
2048         struct module *mod;
2049
2050         preempt_disable();
2051         mod = __module_address((unsigned long)btp);
2052         module_put(mod);
2053         preempt_enable();
2054 }
2055
2056 static __always_inline
2057 void __bpf_trace_run(struct bpf_prog *prog, u64 *args)
2058 {
2059         cant_sleep();
2060         rcu_read_lock();
2061         (void) BPF_PROG_RUN(prog, args);
2062         rcu_read_unlock();
2063 }
2064
2065 #define UNPACK(...)                     __VA_ARGS__
2066 #define REPEAT_1(FN, DL, X, ...)        FN(X)
2067 #define REPEAT_2(FN, DL, X, ...)        FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__)
2068 #define REPEAT_3(FN, DL, X, ...)        FN(X) UNPACK DL REPEAT_2(FN, DL, __VA_ARGS__)
2069 #define REPEAT_4(FN, DL, X, ...)        FN(X) UNPACK DL REPEAT_3(FN, DL, __VA_ARGS__)
2070 #define REPEAT_5(FN, DL, X, ...)        FN(X) UNPACK DL REPEAT_4(FN, DL, __VA_ARGS__)
2071 #define REPEAT_6(FN, DL, X, ...)        FN(X) UNPACK DL REPEAT_5(FN, DL, __VA_ARGS__)
2072 #define REPEAT_7(FN, DL, X, ...)        FN(X) UNPACK DL REPEAT_6(FN, DL, __VA_ARGS__)
2073 #define REPEAT_8(FN, DL, X, ...)        FN(X) UNPACK DL REPEAT_7(FN, DL, __VA_ARGS__)
2074 #define REPEAT_9(FN, DL, X, ...)        FN(X) UNPACK DL REPEAT_8(FN, DL, __VA_ARGS__)
2075 #define REPEAT_10(FN, DL, X, ...)       FN(X) UNPACK DL REPEAT_9(FN, DL, __VA_ARGS__)
2076 #define REPEAT_11(FN, DL, X, ...)       FN(X) UNPACK DL REPEAT_10(FN, DL, __VA_ARGS__)
2077 #define REPEAT_12(FN, DL, X, ...)       FN(X) UNPACK DL REPEAT_11(FN, DL, __VA_ARGS__)
2078 #define REPEAT(X, FN, DL, ...)          REPEAT_##X(FN, DL, __VA_ARGS__)
2079
2080 #define SARG(X)         u64 arg##X
2081 #define COPY(X)         args[X] = arg##X
2082
2083 #define __DL_COM        (,)
2084 #define __DL_SEM        (;)
2085
2086 #define __SEQ_0_11      0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11
2087
2088 #define BPF_TRACE_DEFN_x(x)                                             \
2089         void bpf_trace_run##x(struct bpf_prog *prog,                    \
2090                               REPEAT(x, SARG, __DL_COM, __SEQ_0_11))    \
2091         {                                                               \
2092                 u64 args[x];                                            \
2093                 REPEAT(x, COPY, __DL_SEM, __SEQ_0_11);                  \
2094                 __bpf_trace_run(prog, args);                            \
2095         }                                                               \
2096         EXPORT_SYMBOL_GPL(bpf_trace_run##x)
2097 BPF_TRACE_DEFN_x(1);
2098 BPF_TRACE_DEFN_x(2);
2099 BPF_TRACE_DEFN_x(3);
2100 BPF_TRACE_DEFN_x(4);
2101 BPF_TRACE_DEFN_x(5);
2102 BPF_TRACE_DEFN_x(6);
2103 BPF_TRACE_DEFN_x(7);
2104 BPF_TRACE_DEFN_x(8);
2105 BPF_TRACE_DEFN_x(9);
2106 BPF_TRACE_DEFN_x(10);
2107 BPF_TRACE_DEFN_x(11);
2108 BPF_TRACE_DEFN_x(12);
2109
2110 static int __bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog)
2111 {
2112         struct tracepoint *tp = btp->tp;
2113
2114         /*
2115          * check that program doesn't access arguments beyond what's
2116          * available in this tracepoint
2117          */
2118         if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64))
2119                 return -EINVAL;
2120
2121         if (prog->aux->max_tp_access > btp->writable_size)
2122                 return -EINVAL;
2123
2124         return tracepoint_probe_register_may_exist(tp, (void *)btp->bpf_func,
2125                                                    prog);
2126 }
2127
2128 int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog)
2129 {
2130         return __bpf_probe_register(btp, prog);
2131 }
2132
2133 int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_prog *prog)
2134 {
2135         return tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, prog);
2136 }
2137
2138 int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id,
2139                             u32 *fd_type, const char **buf,
2140                             u64 *probe_offset, u64 *probe_addr)
2141 {
2142         bool is_tracepoint, is_syscall_tp;
2143         struct bpf_prog *prog;
2144         int flags, err = 0;
2145
2146         prog = event->prog;
2147         if (!prog)
2148                 return -ENOENT;
2149
2150         /* not supporting BPF_PROG_TYPE_PERF_EVENT yet */
2151         if (prog->type == BPF_PROG_TYPE_PERF_EVENT)
2152                 return -EOPNOTSUPP;
2153
2154         *prog_id = prog->aux->id;
2155         flags = event->tp_event->flags;
2156         is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT;
2157         is_syscall_tp = is_syscall_trace_event(event->tp_event);
2158
2159         if (is_tracepoint || is_syscall_tp) {
2160                 *buf = is_tracepoint ? event->tp_event->tp->name
2161                                      : event->tp_event->name;
2162                 *fd_type = BPF_FD_TYPE_TRACEPOINT;
2163                 *probe_offset = 0x0;
2164                 *probe_addr = 0x0;
2165         } else {
2166                 /* kprobe/uprobe */
2167                 err = -EOPNOTSUPP;
2168 #ifdef CONFIG_KPROBE_EVENTS
2169                 if (flags & TRACE_EVENT_FL_KPROBE)
2170                         err = bpf_get_kprobe_info(event, fd_type, buf,
2171                                                   probe_offset, probe_addr,
2172                                                   event->attr.type == PERF_TYPE_TRACEPOINT);
2173 #endif
2174 #ifdef CONFIG_UPROBE_EVENTS
2175                 if (flags & TRACE_EVENT_FL_UPROBE)
2176                         err = bpf_get_uprobe_info(event, fd_type, buf,
2177                                                   probe_offset, probe_addr,
2178                                                   event->attr.type == PERF_TYPE_TRACEPOINT);
2179 #endif
2180         }
2181
2182         return err;
2183 }
2184
2185 static int __init send_signal_irq_work_init(void)
2186 {
2187         int cpu;
2188         struct send_signal_irq_work *work;
2189
2190         for_each_possible_cpu(cpu) {
2191                 work = per_cpu_ptr(&send_signal_work, cpu);
2192                 init_irq_work(&work->irq_work, do_bpf_send_signal);
2193         }
2194         return 0;
2195 }
2196
2197 subsys_initcall(send_signal_irq_work_init);
2198
2199 #ifdef CONFIG_MODULES
2200 static int bpf_event_notify(struct notifier_block *nb, unsigned long op,
2201                             void *module)
2202 {
2203         struct bpf_trace_module *btm, *tmp;
2204         struct module *mod = module;
2205         int ret = 0;
2206
2207         if (mod->num_bpf_raw_events == 0 ||
2208             (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING))
2209                 goto out;
2210
2211         mutex_lock(&bpf_module_mutex);
2212
2213         switch (op) {
2214         case MODULE_STATE_COMING:
2215                 btm = kzalloc(sizeof(*btm), GFP_KERNEL);
2216                 if (btm) {
2217                         btm->module = module;
2218                         list_add(&btm->list, &bpf_trace_modules);
2219                 } else {
2220                         ret = -ENOMEM;
2221                 }
2222                 break;
2223         case MODULE_STATE_GOING:
2224                 list_for_each_entry_safe(btm, tmp, &bpf_trace_modules, list) {
2225                         if (btm->module == module) {
2226                                 list_del(&btm->list);
2227                                 kfree(btm);
2228                                 break;
2229                         }
2230                 }
2231                 break;
2232         }
2233
2234         mutex_unlock(&bpf_module_mutex);
2235
2236 out:
2237         return notifier_from_errno(ret);
2238 }
2239
2240 static struct notifier_block bpf_module_nb = {
2241         .notifier_call = bpf_event_notify,
2242 };
2243
2244 static int __init bpf_event_init(void)
2245 {
2246         register_module_notifier(&bpf_module_nb);
2247         return 0;
2248 }
2249
2250 fs_initcall(bpf_event_init);
2251 #endif /* CONFIG_MODULES */