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