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