| 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 | preempt_disable(); |
| 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 | preempt_enable(); |
| 119 | |
| 120 | return ret; |
| 121 | } |
| 122 | EXPORT_SYMBOL_GPL(trace_call_bpf); |
| 123 | |
| 124 | #ifdef CONFIG_BPF_KPROBE_OVERRIDE |
| 125 | BPF_CALL_2(bpf_override_return, struct pt_regs *, regs, unsigned long, rc) |
| 126 | { |
| 127 | regs_set_return_value(regs, rc); |
| 128 | override_function_with_return(regs); |
| 129 | return 0; |
| 130 | } |
| 131 | |
| 132 | static const struct bpf_func_proto bpf_override_return_proto = { |
| 133 | .func = bpf_override_return, |
| 134 | .gpl_only = true, |
| 135 | .ret_type = RET_INTEGER, |
| 136 | .arg1_type = ARG_PTR_TO_CTX, |
| 137 | .arg2_type = ARG_ANYTHING, |
| 138 | }; |
| 139 | #endif |
| 140 | |
| 141 | BPF_CALL_3(bpf_probe_read_user, void *, dst, u32, size, |
| 142 | const void __user *, unsafe_ptr) |
| 143 | { |
| 144 | int ret = probe_user_read(dst, unsafe_ptr, size); |
| 145 | |
| 146 | if (unlikely(ret < 0)) |
| 147 | memset(dst, 0, size); |
| 148 | |
| 149 | return ret; |
| 150 | } |
| 151 | |
| 152 | static const struct bpf_func_proto bpf_probe_read_user_proto = { |
| 153 | .func = bpf_probe_read_user, |
| 154 | .gpl_only = true, |
| 155 | .ret_type = RET_INTEGER, |
| 156 | .arg1_type = ARG_PTR_TO_UNINIT_MEM, |
| 157 | .arg2_type = ARG_CONST_SIZE_OR_ZERO, |
| 158 | .arg3_type = ARG_ANYTHING, |
| 159 | }; |
| 160 | |
| 161 | BPF_CALL_3(bpf_probe_read_user_str, void *, dst, u32, size, |
| 162 | const void __user *, unsafe_ptr) |
| 163 | { |
| 164 | int ret = strncpy_from_unsafe_user(dst, unsafe_ptr, size); |
| 165 | |
| 166 | if (unlikely(ret < 0)) |
| 167 | memset(dst, 0, size); |
| 168 | |
| 169 | return ret; |
| 170 | } |
| 171 | |
| 172 | static const struct bpf_func_proto bpf_probe_read_user_str_proto = { |
| 173 | .func = bpf_probe_read_user_str, |
| 174 | .gpl_only = true, |
| 175 | .ret_type = RET_INTEGER, |
| 176 | .arg1_type = ARG_PTR_TO_UNINIT_MEM, |
| 177 | .arg2_type = ARG_CONST_SIZE_OR_ZERO, |
| 178 | .arg3_type = ARG_ANYTHING, |
| 179 | }; |
| 180 | |
| 181 | static __always_inline int |
| 182 | bpf_probe_read_kernel_common(void *dst, u32 size, const void *unsafe_ptr, |
| 183 | const bool compat) |
| 184 | { |
| 185 | int ret = security_locked_down(LOCKDOWN_BPF_READ); |
| 186 | |
| 187 | if (unlikely(ret < 0)) |
| 188 | goto out; |
| 189 | ret = compat ? probe_kernel_read(dst, unsafe_ptr, size) : |
| 190 | probe_kernel_read_strict(dst, unsafe_ptr, size); |
| 191 | if (unlikely(ret < 0)) |
| 192 | out: |
| 193 | memset(dst, 0, size); |
| 194 | return ret; |
| 195 | } |
| 196 | |
| 197 | BPF_CALL_3(bpf_probe_read_kernel, void *, dst, u32, size, |
| 198 | const void *, unsafe_ptr) |
| 199 | { |
| 200 | return bpf_probe_read_kernel_common(dst, size, unsafe_ptr, false); |
| 201 | } |
| 202 | |
| 203 | static const struct bpf_func_proto bpf_probe_read_kernel_proto = { |
| 204 | .func = bpf_probe_read_kernel, |
| 205 | .gpl_only = true, |
| 206 | .ret_type = RET_INTEGER, |
| 207 | .arg1_type = ARG_PTR_TO_UNINIT_MEM, |
| 208 | .arg2_type = ARG_CONST_SIZE_OR_ZERO, |
| 209 | .arg3_type = ARG_ANYTHING, |
| 210 | }; |
| 211 | |
| 212 | BPF_CALL_3(bpf_probe_read_compat, void *, dst, u32, size, |
| 213 | const void *, unsafe_ptr) |
| 214 | { |
| 215 | return bpf_probe_read_kernel_common(dst, size, unsafe_ptr, true); |
| 216 | } |
| 217 | |
| 218 | static const struct bpf_func_proto bpf_probe_read_compat_proto = { |
| 219 | .func = bpf_probe_read_compat, |
| 220 | .gpl_only = true, |
| 221 | .ret_type = RET_INTEGER, |
| 222 | .arg1_type = ARG_PTR_TO_UNINIT_MEM, |
| 223 | .arg2_type = ARG_CONST_SIZE_OR_ZERO, |
| 224 | .arg3_type = ARG_ANYTHING, |
| 225 | }; |
| 226 | |
| 227 | static __always_inline int |
| 228 | bpf_probe_read_kernel_str_common(void *dst, u32 size, const void *unsafe_ptr, |
| 229 | const bool compat) |
| 230 | { |
| 231 | int ret = security_locked_down(LOCKDOWN_BPF_READ); |
| 232 | |
| 233 | if (unlikely(ret < 0)) |
| 234 | goto out; |
| 235 | /* |
| 236 | * The strncpy_from_unsafe_*() call will likely not fill the entire |
| 237 | * buffer, but that's okay in this circumstance as we're probing |
| 238 | * arbitrary memory anyway similar to bpf_probe_read_*() and might |
| 239 | * as well probe the stack. Thus, memory is explicitly cleared |
| 240 | * only in error case, so that improper users ignoring return |
| 241 | * code altogether don't copy garbage; otherwise length of string |
| 242 | * is returned that can be used for bpf_perf_event_output() et al. |
| 243 | */ |
| 244 | ret = compat ? strncpy_from_unsafe(dst, unsafe_ptr, size) : |
| 245 | strncpy_from_unsafe_strict(dst, unsafe_ptr, size); |
| 246 | if (unlikely(ret < 0)) |
| 247 | out: |
| 248 | memset(dst, 0, size); |
| 249 | return ret; |
| 250 | } |
| 251 | |
| 252 | BPF_CALL_3(bpf_probe_read_kernel_str, void *, dst, u32, size, |
| 253 | const void *, unsafe_ptr) |
| 254 | { |
| 255 | return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr, false); |
| 256 | } |
| 257 | |
| 258 | static const struct bpf_func_proto bpf_probe_read_kernel_str_proto = { |
| 259 | .func = bpf_probe_read_kernel_str, |
| 260 | .gpl_only = true, |
| 261 | .ret_type = RET_INTEGER, |
| 262 | .arg1_type = ARG_PTR_TO_UNINIT_MEM, |
| 263 | .arg2_type = ARG_CONST_SIZE_OR_ZERO, |
| 264 | .arg3_type = ARG_ANYTHING, |
| 265 | }; |
| 266 | |
| 267 | BPF_CALL_3(bpf_probe_read_compat_str, void *, dst, u32, size, |
| 268 | const void *, unsafe_ptr) |
| 269 | { |
| 270 | return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr, true); |
| 271 | } |
| 272 | |
| 273 | static const struct bpf_func_proto bpf_probe_read_compat_str_proto = { |
| 274 | .func = bpf_probe_read_compat_str, |
| 275 | .gpl_only = true, |
| 276 | .ret_type = RET_INTEGER, |
| 277 | .arg1_type = ARG_PTR_TO_UNINIT_MEM, |
| 278 | .arg2_type = ARG_CONST_SIZE_OR_ZERO, |
| 279 | .arg3_type = ARG_ANYTHING, |
| 280 | }; |
| 281 | |
| 282 | BPF_CALL_3(bpf_probe_write_user, void __user *, unsafe_ptr, const void *, src, |
| 283 | u32, size) |
| 284 | { |
| 285 | /* |
| 286 | * Ensure we're in user context which is safe for the helper to |
| 287 | * run. This helper has no business in a kthread. |
| 288 | * |
| 289 | * access_ok() should prevent writing to non-user memory, but in |
| 290 | * some situations (nommu, temporary switch, etc) access_ok() does |
| 291 | * not provide enough validation, hence the check on KERNEL_DS. |
| 292 | * |
| 293 | * nmi_uaccess_okay() ensures the probe is not run in an interim |
| 294 | * state, when the task or mm are switched. This is specifically |
| 295 | * required to prevent the use of temporary mm. |
| 296 | */ |
| 297 | |
| 298 | if (unlikely(in_interrupt() || |
| 299 | current->flags & (PF_KTHREAD | PF_EXITING))) |
| 300 | return -EPERM; |
| 301 | if (unlikely(uaccess_kernel())) |
| 302 | return -EPERM; |
| 303 | if (unlikely(!nmi_uaccess_okay())) |
| 304 | return -EPERM; |
| 305 | |
| 306 | return probe_user_write(unsafe_ptr, src, size); |
| 307 | } |
| 308 | |
| 309 | static const struct bpf_func_proto bpf_probe_write_user_proto = { |
| 310 | .func = bpf_probe_write_user, |
| 311 | .gpl_only = true, |
| 312 | .ret_type = RET_INTEGER, |
| 313 | .arg1_type = ARG_ANYTHING, |
| 314 | .arg2_type = ARG_PTR_TO_MEM, |
| 315 | .arg3_type = ARG_CONST_SIZE, |
| 316 | }; |
| 317 | |
| 318 | static const struct bpf_func_proto *bpf_get_probe_write_proto(void) |
| 319 | { |
| 320 | pr_warn_ratelimited("%s[%d] is installing a program with bpf_probe_write_user helper that may corrupt user memory!", |
| 321 | current->comm, task_pid_nr(current)); |
| 322 | |
| 323 | return &bpf_probe_write_user_proto; |
| 324 | } |
| 325 | |
| 326 | /* |
| 327 | * Only limited trace_printk() conversion specifiers allowed: |
| 328 | * %d %i %u %x %ld %li %lu %lx %lld %lli %llu %llx %p %s |
| 329 | */ |
| 330 | BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1, |
| 331 | u64, arg2, u64, arg3) |
| 332 | { |
| 333 | bool str_seen = false; |
| 334 | int mod[3] = {}; |
| 335 | int fmt_cnt = 0; |
| 336 | u64 unsafe_addr; |
| 337 | char buf[64]; |
| 338 | int i; |
| 339 | |
| 340 | /* |
| 341 | * bpf_check()->check_func_arg()->check_stack_boundary() |
| 342 | * guarantees that fmt points to bpf program stack, |
| 343 | * fmt_size bytes of it were initialized and fmt_size > 0 |
| 344 | */ |
| 345 | if (fmt[--fmt_size] != 0) |
| 346 | return -EINVAL; |
| 347 | |
| 348 | /* check format string for allowed specifiers */ |
| 349 | for (i = 0; i < fmt_size; i++) { |
| 350 | if ((!isprint(fmt[i]) && !isspace(fmt[i])) || !isascii(fmt[i])) |
| 351 | return -EINVAL; |
| 352 | |
| 353 | if (fmt[i] != '%') |
| 354 | continue; |
| 355 | |
| 356 | if (fmt_cnt >= 3) |
| 357 | return -EINVAL; |
| 358 | |
| 359 | /* fmt[i] != 0 && fmt[last] == 0, so we can access fmt[i + 1] */ |
| 360 | i++; |
| 361 | if (fmt[i] == 'l') { |
| 362 | mod[fmt_cnt]++; |
| 363 | i++; |
| 364 | } else if (fmt[i] == 'p' || fmt[i] == 's') { |
| 365 | mod[fmt_cnt]++; |
| 366 | /* disallow any further format extensions */ |
| 367 | if (fmt[i + 1] != 0 && |
| 368 | !isspace(fmt[i + 1]) && |
| 369 | !ispunct(fmt[i + 1])) |
| 370 | return -EINVAL; |
| 371 | fmt_cnt++; |
| 372 | if (fmt[i] == 's') { |
| 373 | if (str_seen) |
| 374 | /* allow only one '%s' per fmt string */ |
| 375 | return -EINVAL; |
| 376 | str_seen = true; |
| 377 | |
| 378 | switch (fmt_cnt) { |
| 379 | case 1: |
| 380 | unsafe_addr = arg1; |
| 381 | arg1 = (long) buf; |
| 382 | break; |
| 383 | case 2: |
| 384 | unsafe_addr = arg2; |
| 385 | arg2 = (long) buf; |
| 386 | break; |
| 387 | case 3: |
| 388 | unsafe_addr = arg3; |
| 389 | arg3 = (long) buf; |
| 390 | break; |
| 391 | } |
| 392 | buf[0] = 0; |
| 393 | strncpy_from_unsafe(buf, |
| 394 | (void *) (long) unsafe_addr, |
| 395 | sizeof(buf)); |
| 396 | } |
| 397 | continue; |
| 398 | } |
| 399 | |
| 400 | if (fmt[i] == 'l') { |
| 401 | mod[fmt_cnt]++; |
| 402 | i++; |
| 403 | } |
| 404 | |
| 405 | if (fmt[i] != 'i' && fmt[i] != 'd' && |
| 406 | fmt[i] != 'u' && fmt[i] != 'x') |
| 407 | return -EINVAL; |
| 408 | fmt_cnt++; |
| 409 | } |
| 410 | |
| 411 | /* Horrid workaround for getting va_list handling working with different |
| 412 | * argument type combinations generically for 32 and 64 bit archs. |
| 413 | */ |
| 414 | #define __BPF_TP_EMIT() __BPF_ARG3_TP() |
| 415 | #define __BPF_TP(...) \ |
| 416 | __trace_printk(0 /* Fake ip */, \ |
| 417 | fmt, ##__VA_ARGS__) |
| 418 | |
| 419 | #define __BPF_ARG1_TP(...) \ |
| 420 | ((mod[0] == 2 || (mod[0] == 1 && __BITS_PER_LONG == 64)) \ |
| 421 | ? __BPF_TP(arg1, ##__VA_ARGS__) \ |
| 422 | : ((mod[0] == 1 || (mod[0] == 0 && __BITS_PER_LONG == 32)) \ |
| 423 | ? __BPF_TP((long)arg1, ##__VA_ARGS__) \ |
| 424 | : __BPF_TP((u32)arg1, ##__VA_ARGS__))) |
| 425 | |
| 426 | #define __BPF_ARG2_TP(...) \ |
| 427 | ((mod[1] == 2 || (mod[1] == 1 && __BITS_PER_LONG == 64)) \ |
| 428 | ? __BPF_ARG1_TP(arg2, ##__VA_ARGS__) \ |
| 429 | : ((mod[1] == 1 || (mod[1] == 0 && __BITS_PER_LONG == 32)) \ |
| 430 | ? __BPF_ARG1_TP((long)arg2, ##__VA_ARGS__) \ |
| 431 | : __BPF_ARG1_TP((u32)arg2, ##__VA_ARGS__))) |
| 432 | |
| 433 | #define __BPF_ARG3_TP(...) \ |
| 434 | ((mod[2] == 2 || (mod[2] == 1 && __BITS_PER_LONG == 64)) \ |
| 435 | ? __BPF_ARG2_TP(arg3, ##__VA_ARGS__) \ |
| 436 | : ((mod[2] == 1 || (mod[2] == 0 && __BITS_PER_LONG == 32)) \ |
| 437 | ? __BPF_ARG2_TP((long)arg3, ##__VA_ARGS__) \ |
| 438 | : __BPF_ARG2_TP((u32)arg3, ##__VA_ARGS__))) |
| 439 | |
| 440 | return __BPF_TP_EMIT(); |
| 441 | } |
| 442 | |
| 443 | static const struct bpf_func_proto bpf_trace_printk_proto = { |
| 444 | .func = bpf_trace_printk, |
| 445 | .gpl_only = true, |
| 446 | .ret_type = RET_INTEGER, |
| 447 | .arg1_type = ARG_PTR_TO_MEM, |
| 448 | .arg2_type = ARG_CONST_SIZE, |
| 449 | }; |
| 450 | |
| 451 | const struct bpf_func_proto *bpf_get_trace_printk_proto(void) |
| 452 | { |
| 453 | /* |
| 454 | * this program might be calling bpf_trace_printk, |
| 455 | * so allocate per-cpu printk buffers |
| 456 | */ |
| 457 | trace_printk_init_buffers(); |
| 458 | |
| 459 | return &bpf_trace_printk_proto; |
| 460 | } |
| 461 | |
| 462 | static __always_inline int |
| 463 | get_map_perf_counter(struct bpf_map *map, u64 flags, |
| 464 | u64 *value, u64 *enabled, u64 *running) |
| 465 | { |
| 466 | struct bpf_array *array = container_of(map, struct bpf_array, map); |
| 467 | unsigned int cpu = smp_processor_id(); |
| 468 | u64 index = flags & BPF_F_INDEX_MASK; |
| 469 | struct bpf_event_entry *ee; |
| 470 | |
| 471 | if (unlikely(flags & ~(BPF_F_INDEX_MASK))) |
| 472 | return -EINVAL; |
| 473 | if (index == BPF_F_CURRENT_CPU) |
| 474 | index = cpu; |
| 475 | if (unlikely(index >= array->map.max_entries)) |
| 476 | return -E2BIG; |
| 477 | |
| 478 | ee = READ_ONCE(array->ptrs[index]); |
| 479 | if (!ee) |
| 480 | return -ENOENT; |
| 481 | |
| 482 | return perf_event_read_local(ee->event, value, enabled, running); |
| 483 | } |
| 484 | |
| 485 | BPF_CALL_2(bpf_perf_event_read, struct bpf_map *, map, u64, flags) |
| 486 | { |
| 487 | u64 value = 0; |
| 488 | int err; |
| 489 | |
| 490 | err = get_map_perf_counter(map, flags, &value, NULL, NULL); |
| 491 | /* |
| 492 | * this api is ugly since we miss [-22..-2] range of valid |
| 493 | * counter values, but that's uapi |
| 494 | */ |
| 495 | if (err) |
| 496 | return err; |
| 497 | return value; |
| 498 | } |
| 499 | |
| 500 | static const struct bpf_func_proto bpf_perf_event_read_proto = { |
| 501 | .func = bpf_perf_event_read, |
| 502 | .gpl_only = true, |
| 503 | .ret_type = RET_INTEGER, |
| 504 | .arg1_type = ARG_CONST_MAP_PTR, |
| 505 | .arg2_type = ARG_ANYTHING, |
| 506 | }; |
| 507 | |
| 508 | BPF_CALL_4(bpf_perf_event_read_value, struct bpf_map *, map, u64, flags, |
| 509 | struct bpf_perf_event_value *, buf, u32, size) |
| 510 | { |
| 511 | int err = -EINVAL; |
| 512 | |
| 513 | if (unlikely(size != sizeof(struct bpf_perf_event_value))) |
| 514 | goto clear; |
| 515 | err = get_map_perf_counter(map, flags, &buf->counter, &buf->enabled, |
| 516 | &buf->running); |
| 517 | if (unlikely(err)) |
| 518 | goto clear; |
| 519 | return 0; |
| 520 | clear: |
| 521 | memset(buf, 0, size); |
| 522 | return err; |
| 523 | } |
| 524 | |
| 525 | static const struct bpf_func_proto bpf_perf_event_read_value_proto = { |
| 526 | .func = bpf_perf_event_read_value, |
| 527 | .gpl_only = true, |
| 528 | .ret_type = RET_INTEGER, |
| 529 | .arg1_type = ARG_CONST_MAP_PTR, |
| 530 | .arg2_type = ARG_ANYTHING, |
| 531 | .arg3_type = ARG_PTR_TO_UNINIT_MEM, |
| 532 | .arg4_type = ARG_CONST_SIZE, |
| 533 | }; |
| 534 | |
| 535 | static __always_inline u64 |
| 536 | __bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map, |
| 537 | u64 flags, struct perf_sample_data *sd) |
| 538 | { |
| 539 | struct bpf_array *array = container_of(map, struct bpf_array, map); |
| 540 | unsigned int cpu = smp_processor_id(); |
| 541 | u64 index = flags & BPF_F_INDEX_MASK; |
| 542 | struct bpf_event_entry *ee; |
| 543 | struct perf_event *event; |
| 544 | |
| 545 | if (index == BPF_F_CURRENT_CPU) |
| 546 | index = cpu; |
| 547 | if (unlikely(index >= array->map.max_entries)) |
| 548 | return -E2BIG; |
| 549 | |
| 550 | ee = READ_ONCE(array->ptrs[index]); |
| 551 | if (!ee) |
| 552 | return -ENOENT; |
| 553 | |
| 554 | event = ee->event; |
| 555 | if (unlikely(event->attr.type != PERF_TYPE_SOFTWARE || |
| 556 | event->attr.config != PERF_COUNT_SW_BPF_OUTPUT)) |
| 557 | return -EINVAL; |
| 558 | |
| 559 | if (unlikely(event->oncpu != cpu)) |
| 560 | return -EOPNOTSUPP; |
| 561 | |
| 562 | return perf_event_output(event, sd, regs); |
| 563 | } |
| 564 | |
| 565 | /* |
| 566 | * Support executing tracepoints in normal, irq, and nmi context that each call |
| 567 | * bpf_perf_event_output |
| 568 | */ |
| 569 | struct bpf_trace_sample_data { |
| 570 | struct perf_sample_data sds[3]; |
| 571 | }; |
| 572 | |
| 573 | static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_trace_sds); |
| 574 | static DEFINE_PER_CPU(int, bpf_trace_nest_level); |
| 575 | BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map, |
| 576 | u64, flags, void *, data, u64, size) |
| 577 | { |
| 578 | struct bpf_trace_sample_data *sds = this_cpu_ptr(&bpf_trace_sds); |
| 579 | int nest_level = this_cpu_inc_return(bpf_trace_nest_level); |
| 580 | struct perf_raw_record raw = { |
| 581 | .frag = { |
| 582 | .size = size, |
| 583 | .data = data, |
| 584 | }, |
| 585 | }; |
| 586 | struct perf_sample_data *sd; |
| 587 | int err; |
| 588 | |
| 589 | if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(sds->sds))) { |
| 590 | err = -EBUSY; |
| 591 | goto out; |
| 592 | } |
| 593 | |
| 594 | sd = &sds->sds[nest_level - 1]; |
| 595 | |
| 596 | if (unlikely(flags & ~(BPF_F_INDEX_MASK))) { |
| 597 | err = -EINVAL; |
| 598 | goto out; |
| 599 | } |
| 600 | |
| 601 | perf_sample_data_init(sd, 0, 0); |
| 602 | sd->raw = &raw; |
| 603 | |
| 604 | err = __bpf_perf_event_output(regs, map, flags, sd); |
| 605 | |
| 606 | out: |
| 607 | this_cpu_dec(bpf_trace_nest_level); |
| 608 | return err; |
| 609 | } |
| 610 | |
| 611 | static const struct bpf_func_proto bpf_perf_event_output_proto = { |
| 612 | .func = bpf_perf_event_output, |
| 613 | .gpl_only = true, |
| 614 | .ret_type = RET_INTEGER, |
| 615 | .arg1_type = ARG_PTR_TO_CTX, |
| 616 | .arg2_type = ARG_CONST_MAP_PTR, |
| 617 | .arg3_type = ARG_ANYTHING, |
| 618 | .arg4_type = ARG_PTR_TO_MEM, |
| 619 | .arg5_type = ARG_CONST_SIZE_OR_ZERO, |
| 620 | }; |
| 621 | |
| 622 | static DEFINE_PER_CPU(int, bpf_event_output_nest_level); |
| 623 | struct bpf_nested_pt_regs { |
| 624 | struct pt_regs regs[3]; |
| 625 | }; |
| 626 | static DEFINE_PER_CPU(struct bpf_nested_pt_regs, bpf_pt_regs); |
| 627 | static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_misc_sds); |
| 628 | |
| 629 | u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size, |
| 630 | void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy) |
| 631 | { |
| 632 | int nest_level = this_cpu_inc_return(bpf_event_output_nest_level); |
| 633 | struct perf_raw_frag frag = { |
| 634 | .copy = ctx_copy, |
| 635 | .size = ctx_size, |
| 636 | .data = ctx, |
| 637 | }; |
| 638 | struct perf_raw_record raw = { |
| 639 | .frag = { |
| 640 | { |
| 641 | .next = ctx_size ? &frag : NULL, |
| 642 | }, |
| 643 | .size = meta_size, |
| 644 | .data = meta, |
| 645 | }, |
| 646 | }; |
| 647 | struct perf_sample_data *sd; |
| 648 | struct pt_regs *regs; |
| 649 | u64 ret; |
| 650 | |
| 651 | if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(bpf_misc_sds.sds))) { |
| 652 | ret = -EBUSY; |
| 653 | goto out; |
| 654 | } |
| 655 | sd = this_cpu_ptr(&bpf_misc_sds.sds[nest_level - 1]); |
| 656 | regs = this_cpu_ptr(&bpf_pt_regs.regs[nest_level - 1]); |
| 657 | |
| 658 | perf_fetch_caller_regs(regs); |
| 659 | perf_sample_data_init(sd, 0, 0); |
| 660 | sd->raw = &raw; |
| 661 | |
| 662 | ret = __bpf_perf_event_output(regs, map, flags, sd); |
| 663 | out: |
| 664 | this_cpu_dec(bpf_event_output_nest_level); |
| 665 | return ret; |
| 666 | } |
| 667 | |
| 668 | BPF_CALL_0(bpf_get_current_task) |
| 669 | { |
| 670 | return (long) current; |
| 671 | } |
| 672 | |
| 673 | static const struct bpf_func_proto bpf_get_current_task_proto = { |
| 674 | .func = bpf_get_current_task, |
| 675 | .gpl_only = true, |
| 676 | .ret_type = RET_INTEGER, |
| 677 | }; |
| 678 | |
| 679 | BPF_CALL_2(bpf_current_task_under_cgroup, struct bpf_map *, map, u32, idx) |
| 680 | { |
| 681 | struct bpf_array *array = container_of(map, struct bpf_array, map); |
| 682 | struct cgroup *cgrp; |
| 683 | |
| 684 | if (unlikely(idx >= array->map.max_entries)) |
| 685 | return -E2BIG; |
| 686 | |
| 687 | cgrp = READ_ONCE(array->ptrs[idx]); |
| 688 | if (unlikely(!cgrp)) |
| 689 | return -EAGAIN; |
| 690 | |
| 691 | return task_under_cgroup_hierarchy(current, cgrp); |
| 692 | } |
| 693 | |
| 694 | static const struct bpf_func_proto bpf_current_task_under_cgroup_proto = { |
| 695 | .func = bpf_current_task_under_cgroup, |
| 696 | .gpl_only = false, |
| 697 | .ret_type = RET_INTEGER, |
| 698 | .arg1_type = ARG_CONST_MAP_PTR, |
| 699 | .arg2_type = ARG_ANYTHING, |
| 700 | }; |
| 701 | |
| 702 | struct send_signal_irq_work { |
| 703 | struct irq_work irq_work; |
| 704 | struct task_struct *task; |
| 705 | u32 sig; |
| 706 | }; |
| 707 | |
| 708 | static DEFINE_PER_CPU(struct send_signal_irq_work, send_signal_work); |
| 709 | |
| 710 | static void do_bpf_send_signal(struct irq_work *entry) |
| 711 | { |
| 712 | struct send_signal_irq_work *work; |
| 713 | |
| 714 | work = container_of(entry, struct send_signal_irq_work, irq_work); |
| 715 | group_send_sig_info(work->sig, SEND_SIG_PRIV, work->task, PIDTYPE_TGID); |
| 716 | } |
| 717 | |
| 718 | BPF_CALL_1(bpf_send_signal, u32, sig) |
| 719 | { |
| 720 | struct send_signal_irq_work *work = NULL; |
| 721 | |
| 722 | /* Similar to bpf_probe_write_user, task needs to be |
| 723 | * in a sound condition and kernel memory access be |
| 724 | * permitted in order to send signal to the current |
| 725 | * task. |
| 726 | */ |
| 727 | if (unlikely(current->flags & (PF_KTHREAD | PF_EXITING))) |
| 728 | return -EPERM; |
| 729 | if (unlikely(uaccess_kernel())) |
| 730 | return -EPERM; |
| 731 | if (unlikely(!nmi_uaccess_okay())) |
| 732 | return -EPERM; |
| 733 | |
| 734 | if (in_nmi()) { |
| 735 | /* Do an early check on signal validity. Otherwise, |
| 736 | * the error is lost in deferred irq_work. |
| 737 | */ |
| 738 | if (unlikely(!valid_signal(sig))) |
| 739 | return -EINVAL; |
| 740 | |
| 741 | work = this_cpu_ptr(&send_signal_work); |
| 742 | if (atomic_read(&work->irq_work.flags) & IRQ_WORK_BUSY) |
| 743 | return -EBUSY; |
| 744 | |
| 745 | /* Add the current task, which is the target of sending signal, |
| 746 | * to the irq_work. The current task may change when queued |
| 747 | * irq works get executed. |
| 748 | */ |
| 749 | work->task = current; |
| 750 | work->sig = sig; |
| 751 | irq_work_queue(&work->irq_work); |
| 752 | return 0; |
| 753 | } |
| 754 | |
| 755 | return group_send_sig_info(sig, SEND_SIG_PRIV, current, PIDTYPE_TGID); |
| 756 | } |
| 757 | |
| 758 | static const struct bpf_func_proto bpf_send_signal_proto = { |
| 759 | .func = bpf_send_signal, |
| 760 | .gpl_only = false, |
| 761 | .ret_type = RET_INTEGER, |
| 762 | .arg1_type = ARG_ANYTHING, |
| 763 | }; |
| 764 | |
| 765 | static const struct bpf_func_proto * |
| 766 | tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) |
| 767 | { |
| 768 | switch (func_id) { |
| 769 | case BPF_FUNC_map_lookup_elem: |
| 770 | return &bpf_map_lookup_elem_proto; |
| 771 | case BPF_FUNC_map_update_elem: |
| 772 | return &bpf_map_update_elem_proto; |
| 773 | case BPF_FUNC_map_delete_elem: |
| 774 | return &bpf_map_delete_elem_proto; |
| 775 | case BPF_FUNC_map_push_elem: |
| 776 | return &bpf_map_push_elem_proto; |
| 777 | case BPF_FUNC_map_pop_elem: |
| 778 | return &bpf_map_pop_elem_proto; |
| 779 | case BPF_FUNC_map_peek_elem: |
| 780 | return &bpf_map_peek_elem_proto; |
| 781 | case BPF_FUNC_ktime_get_ns: |
| 782 | return &bpf_ktime_get_ns_proto; |
| 783 | case BPF_FUNC_tail_call: |
| 784 | return &bpf_tail_call_proto; |
| 785 | case BPF_FUNC_get_current_pid_tgid: |
| 786 | return &bpf_get_current_pid_tgid_proto; |
| 787 | case BPF_FUNC_get_current_task: |
| 788 | return &bpf_get_current_task_proto; |
| 789 | case BPF_FUNC_get_current_uid_gid: |
| 790 | return &bpf_get_current_uid_gid_proto; |
| 791 | case BPF_FUNC_get_current_comm: |
| 792 | return &bpf_get_current_comm_proto; |
| 793 | case BPF_FUNC_trace_printk: |
| 794 | return bpf_get_trace_printk_proto(); |
| 795 | case BPF_FUNC_get_smp_processor_id: |
| 796 | return &bpf_get_smp_processor_id_proto; |
| 797 | case BPF_FUNC_get_numa_node_id: |
| 798 | return &bpf_get_numa_node_id_proto; |
| 799 | case BPF_FUNC_perf_event_read: |
| 800 | return &bpf_perf_event_read_proto; |
| 801 | case BPF_FUNC_probe_write_user: |
| 802 | return bpf_get_probe_write_proto(); |
| 803 | case BPF_FUNC_current_task_under_cgroup: |
| 804 | return &bpf_current_task_under_cgroup_proto; |
| 805 | case BPF_FUNC_get_prandom_u32: |
| 806 | return &bpf_get_prandom_u32_proto; |
| 807 | case BPF_FUNC_probe_read_user: |
| 808 | return &bpf_probe_read_user_proto; |
| 809 | case BPF_FUNC_probe_read_kernel: |
| 810 | return &bpf_probe_read_kernel_proto; |
| 811 | case BPF_FUNC_probe_read: |
| 812 | return &bpf_probe_read_compat_proto; |
| 813 | case BPF_FUNC_probe_read_user_str: |
| 814 | return &bpf_probe_read_user_str_proto; |
| 815 | case BPF_FUNC_probe_read_kernel_str: |
| 816 | return &bpf_probe_read_kernel_str_proto; |
| 817 | case BPF_FUNC_probe_read_str: |
| 818 | return &bpf_probe_read_compat_str_proto; |
| 819 | #ifdef CONFIG_CGROUPS |
| 820 | case BPF_FUNC_get_current_cgroup_id: |
| 821 | return &bpf_get_current_cgroup_id_proto; |
| 822 | #endif |
| 823 | case BPF_FUNC_send_signal: |
| 824 | return &bpf_send_signal_proto; |
| 825 | default: |
| 826 | return NULL; |
| 827 | } |
| 828 | } |
| 829 | |
| 830 | static const struct bpf_func_proto * |
| 831 | kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) |
| 832 | { |
| 833 | switch (func_id) { |
| 834 | case BPF_FUNC_perf_event_output: |
| 835 | return &bpf_perf_event_output_proto; |
| 836 | case BPF_FUNC_get_stackid: |
| 837 | return &bpf_get_stackid_proto; |
| 838 | case BPF_FUNC_get_stack: |
| 839 | return &bpf_get_stack_proto; |
| 840 | case BPF_FUNC_perf_event_read_value: |
| 841 | return &bpf_perf_event_read_value_proto; |
| 842 | #ifdef CONFIG_BPF_KPROBE_OVERRIDE |
| 843 | case BPF_FUNC_override_return: |
| 844 | return &bpf_override_return_proto; |
| 845 | #endif |
| 846 | default: |
| 847 | return tracing_func_proto(func_id, prog); |
| 848 | } |
| 849 | } |
| 850 | |
| 851 | /* bpf+kprobe programs can access fields of 'struct pt_regs' */ |
| 852 | static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type, |
| 853 | const struct bpf_prog *prog, |
| 854 | struct bpf_insn_access_aux *info) |
| 855 | { |
| 856 | if (off < 0 || off >= sizeof(struct pt_regs)) |
| 857 | return false; |
| 858 | if (type != BPF_READ) |
| 859 | return false; |
| 860 | if (off % size != 0) |
| 861 | return false; |
| 862 | /* |
| 863 | * Assertion for 32 bit to make sure last 8 byte access |
| 864 | * (BPF_DW) to the last 4 byte member is disallowed. |
| 865 | */ |
| 866 | if (off + size > sizeof(struct pt_regs)) |
| 867 | return false; |
| 868 | |
| 869 | return true; |
| 870 | } |
| 871 | |
| 872 | const struct bpf_verifier_ops kprobe_verifier_ops = { |
| 873 | .get_func_proto = kprobe_prog_func_proto, |
| 874 | .is_valid_access = kprobe_prog_is_valid_access, |
| 875 | }; |
| 876 | |
| 877 | const struct bpf_prog_ops kprobe_prog_ops = { |
| 878 | }; |
| 879 | |
| 880 | BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map, |
| 881 | u64, flags, void *, data, u64, size) |
| 882 | { |
| 883 | struct pt_regs *regs = *(struct pt_regs **)tp_buff; |
| 884 | |
| 885 | /* |
| 886 | * r1 points to perf tracepoint buffer where first 8 bytes are hidden |
| 887 | * from bpf program and contain a pointer to 'struct pt_regs'. Fetch it |
| 888 | * from there and call the same bpf_perf_event_output() helper inline. |
| 889 | */ |
| 890 | return ____bpf_perf_event_output(regs, map, flags, data, size); |
| 891 | } |
| 892 | |
| 893 | static const struct bpf_func_proto bpf_perf_event_output_proto_tp = { |
| 894 | .func = bpf_perf_event_output_tp, |
| 895 | .gpl_only = true, |
| 896 | .ret_type = RET_INTEGER, |
| 897 | .arg1_type = ARG_PTR_TO_CTX, |
| 898 | .arg2_type = ARG_CONST_MAP_PTR, |
| 899 | .arg3_type = ARG_ANYTHING, |
| 900 | .arg4_type = ARG_PTR_TO_MEM, |
| 901 | .arg5_type = ARG_CONST_SIZE_OR_ZERO, |
| 902 | }; |
| 903 | |
| 904 | BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map, |
| 905 | u64, flags) |
| 906 | { |
| 907 | struct pt_regs *regs = *(struct pt_regs **)tp_buff; |
| 908 | |
| 909 | /* |
| 910 | * Same comment as in bpf_perf_event_output_tp(), only that this time |
| 911 | * the other helper's function body cannot be inlined due to being |
| 912 | * external, thus we need to call raw helper function. |
| 913 | */ |
| 914 | return bpf_get_stackid((unsigned long) regs, (unsigned long) map, |
| 915 | flags, 0, 0); |
| 916 | } |
| 917 | |
| 918 | static const struct bpf_func_proto bpf_get_stackid_proto_tp = { |
| 919 | .func = bpf_get_stackid_tp, |
| 920 | .gpl_only = true, |
| 921 | .ret_type = RET_INTEGER, |
| 922 | .arg1_type = ARG_PTR_TO_CTX, |
| 923 | .arg2_type = ARG_CONST_MAP_PTR, |
| 924 | .arg3_type = ARG_ANYTHING, |
| 925 | }; |
| 926 | |
| 927 | BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size, |
| 928 | u64, flags) |
| 929 | { |
| 930 | struct pt_regs *regs = *(struct pt_regs **)tp_buff; |
| 931 | |
| 932 | return bpf_get_stack((unsigned long) regs, (unsigned long) buf, |
| 933 | (unsigned long) size, flags, 0); |
| 934 | } |
| 935 | |
| 936 | static const struct bpf_func_proto bpf_get_stack_proto_tp = { |
| 937 | .func = bpf_get_stack_tp, |
| 938 | .gpl_only = true, |
| 939 | .ret_type = RET_INTEGER, |
| 940 | .arg1_type = ARG_PTR_TO_CTX, |
| 941 | .arg2_type = ARG_PTR_TO_UNINIT_MEM, |
| 942 | .arg3_type = ARG_CONST_SIZE_OR_ZERO, |
| 943 | .arg4_type = ARG_ANYTHING, |
| 944 | }; |
| 945 | |
| 946 | static const struct bpf_func_proto * |
| 947 | tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) |
| 948 | { |
| 949 | switch (func_id) { |
| 950 | case BPF_FUNC_perf_event_output: |
| 951 | return &bpf_perf_event_output_proto_tp; |
| 952 | case BPF_FUNC_get_stackid: |
| 953 | return &bpf_get_stackid_proto_tp; |
| 954 | case BPF_FUNC_get_stack: |
| 955 | return &bpf_get_stack_proto_tp; |
| 956 | default: |
| 957 | return tracing_func_proto(func_id, prog); |
| 958 | } |
| 959 | } |
| 960 | |
| 961 | static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type, |
| 962 | const struct bpf_prog *prog, |
| 963 | struct bpf_insn_access_aux *info) |
| 964 | { |
| 965 | if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE) |
| 966 | return false; |
| 967 | if (type != BPF_READ) |
| 968 | return false; |
| 969 | if (off % size != 0) |
| 970 | return false; |
| 971 | |
| 972 | BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(__u64)); |
| 973 | return true; |
| 974 | } |
| 975 | |
| 976 | const struct bpf_verifier_ops tracepoint_verifier_ops = { |
| 977 | .get_func_proto = tp_prog_func_proto, |
| 978 | .is_valid_access = tp_prog_is_valid_access, |
| 979 | }; |
| 980 | |
| 981 | const struct bpf_prog_ops tracepoint_prog_ops = { |
| 982 | }; |
| 983 | |
| 984 | BPF_CALL_3(bpf_perf_prog_read_value, struct bpf_perf_event_data_kern *, ctx, |
| 985 | struct bpf_perf_event_value *, buf, u32, size) |
| 986 | { |
| 987 | int err = -EINVAL; |
| 988 | |
| 989 | if (unlikely(size != sizeof(struct bpf_perf_event_value))) |
| 990 | goto clear; |
| 991 | err = perf_event_read_local(ctx->event, &buf->counter, &buf->enabled, |
| 992 | &buf->running); |
| 993 | if (unlikely(err)) |
| 994 | goto clear; |
| 995 | return 0; |
| 996 | clear: |
| 997 | memset(buf, 0, size); |
| 998 | return err; |
| 999 | } |
| 1000 | |
| 1001 | static const struct bpf_func_proto bpf_perf_prog_read_value_proto = { |
| 1002 | .func = bpf_perf_prog_read_value, |
| 1003 | .gpl_only = true, |
| 1004 | .ret_type = RET_INTEGER, |
| 1005 | .arg1_type = ARG_PTR_TO_CTX, |
| 1006 | .arg2_type = ARG_PTR_TO_UNINIT_MEM, |
| 1007 | .arg3_type = ARG_CONST_SIZE, |
| 1008 | }; |
| 1009 | |
| 1010 | static const struct bpf_func_proto * |
| 1011 | pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) |
| 1012 | { |
| 1013 | switch (func_id) { |
| 1014 | case BPF_FUNC_perf_event_output: |
| 1015 | return &bpf_perf_event_output_proto_tp; |
| 1016 | case BPF_FUNC_get_stackid: |
| 1017 | return &bpf_get_stackid_proto_tp; |
| 1018 | case BPF_FUNC_get_stack: |
| 1019 | return &bpf_get_stack_proto_tp; |
| 1020 | case BPF_FUNC_perf_prog_read_value: |
| 1021 | return &bpf_perf_prog_read_value_proto; |
| 1022 | default: |
| 1023 | return tracing_func_proto(func_id, prog); |
| 1024 | } |
| 1025 | } |
| 1026 | |
| 1027 | /* |
| 1028 | * bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp |
| 1029 | * to avoid potential recursive reuse issue when/if tracepoints are added |
| 1030 | * inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack. |
| 1031 | * |
| 1032 | * Since raw tracepoints run despite bpf_prog_active, support concurrent usage |
| 1033 | * in normal, irq, and nmi context. |
| 1034 | */ |
| 1035 | struct bpf_raw_tp_regs { |
| 1036 | struct pt_regs regs[3]; |
| 1037 | }; |
| 1038 | static DEFINE_PER_CPU(struct bpf_raw_tp_regs, bpf_raw_tp_regs); |
| 1039 | static DEFINE_PER_CPU(int, bpf_raw_tp_nest_level); |
| 1040 | static struct pt_regs *get_bpf_raw_tp_regs(void) |
| 1041 | { |
| 1042 | struct bpf_raw_tp_regs *tp_regs = this_cpu_ptr(&bpf_raw_tp_regs); |
| 1043 | int nest_level = this_cpu_inc_return(bpf_raw_tp_nest_level); |
| 1044 | |
| 1045 | if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(tp_regs->regs))) { |
| 1046 | this_cpu_dec(bpf_raw_tp_nest_level); |
| 1047 | return ERR_PTR(-EBUSY); |
| 1048 | } |
| 1049 | |
| 1050 | return &tp_regs->regs[nest_level - 1]; |
| 1051 | } |
| 1052 | |
| 1053 | static void put_bpf_raw_tp_regs(void) |
| 1054 | { |
| 1055 | this_cpu_dec(bpf_raw_tp_nest_level); |
| 1056 | } |
| 1057 | |
| 1058 | BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args, |
| 1059 | struct bpf_map *, map, u64, flags, void *, data, u64, size) |
| 1060 | { |
| 1061 | struct pt_regs *regs = get_bpf_raw_tp_regs(); |
| 1062 | int ret; |
| 1063 | |
| 1064 | if (IS_ERR(regs)) |
| 1065 | return PTR_ERR(regs); |
| 1066 | |
| 1067 | perf_fetch_caller_regs(regs); |
| 1068 | ret = ____bpf_perf_event_output(regs, map, flags, data, size); |
| 1069 | |
| 1070 | put_bpf_raw_tp_regs(); |
| 1071 | return ret; |
| 1072 | } |
| 1073 | |
| 1074 | static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = { |
| 1075 | .func = bpf_perf_event_output_raw_tp, |
| 1076 | .gpl_only = true, |
| 1077 | .ret_type = RET_INTEGER, |
| 1078 | .arg1_type = ARG_PTR_TO_CTX, |
| 1079 | .arg2_type = ARG_CONST_MAP_PTR, |
| 1080 | .arg3_type = ARG_ANYTHING, |
| 1081 | .arg4_type = ARG_PTR_TO_MEM, |
| 1082 | .arg5_type = ARG_CONST_SIZE_OR_ZERO, |
| 1083 | }; |
| 1084 | |
| 1085 | extern const struct bpf_func_proto bpf_skb_output_proto; |
| 1086 | |
| 1087 | BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args, |
| 1088 | struct bpf_map *, map, u64, flags) |
| 1089 | { |
| 1090 | struct pt_regs *regs = get_bpf_raw_tp_regs(); |
| 1091 | int ret; |
| 1092 | |
| 1093 | if (IS_ERR(regs)) |
| 1094 | return PTR_ERR(regs); |
| 1095 | |
| 1096 | perf_fetch_caller_regs(regs); |
| 1097 | /* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */ |
| 1098 | ret = bpf_get_stackid((unsigned long) regs, (unsigned long) map, |
| 1099 | flags, 0, 0); |
| 1100 | put_bpf_raw_tp_regs(); |
| 1101 | return ret; |
| 1102 | } |
| 1103 | |
| 1104 | static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = { |
| 1105 | .func = bpf_get_stackid_raw_tp, |
| 1106 | .gpl_only = true, |
| 1107 | .ret_type = RET_INTEGER, |
| 1108 | .arg1_type = ARG_PTR_TO_CTX, |
| 1109 | .arg2_type = ARG_CONST_MAP_PTR, |
| 1110 | .arg3_type = ARG_ANYTHING, |
| 1111 | }; |
| 1112 | |
| 1113 | BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args, |
| 1114 | void *, buf, u32, size, u64, flags) |
| 1115 | { |
| 1116 | struct pt_regs *regs = get_bpf_raw_tp_regs(); |
| 1117 | int ret; |
| 1118 | |
| 1119 | if (IS_ERR(regs)) |
| 1120 | return PTR_ERR(regs); |
| 1121 | |
| 1122 | perf_fetch_caller_regs(regs); |
| 1123 | ret = bpf_get_stack((unsigned long) regs, (unsigned long) buf, |
| 1124 | (unsigned long) size, flags, 0); |
| 1125 | put_bpf_raw_tp_regs(); |
| 1126 | return ret; |
| 1127 | } |
| 1128 | |
| 1129 | static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = { |
| 1130 | .func = bpf_get_stack_raw_tp, |
| 1131 | .gpl_only = true, |
| 1132 | .ret_type = RET_INTEGER, |
| 1133 | .arg1_type = ARG_PTR_TO_CTX, |
| 1134 | .arg2_type = ARG_PTR_TO_MEM, |
| 1135 | .arg3_type = ARG_CONST_SIZE_OR_ZERO, |
| 1136 | .arg4_type = ARG_ANYTHING, |
| 1137 | }; |
| 1138 | |
| 1139 | static const struct bpf_func_proto * |
| 1140 | raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) |
| 1141 | { |
| 1142 | switch (func_id) { |
| 1143 | case BPF_FUNC_perf_event_output: |
| 1144 | return &bpf_perf_event_output_proto_raw_tp; |
| 1145 | case BPF_FUNC_get_stackid: |
| 1146 | return &bpf_get_stackid_proto_raw_tp; |
| 1147 | case BPF_FUNC_get_stack: |
| 1148 | return &bpf_get_stack_proto_raw_tp; |
| 1149 | default: |
| 1150 | return tracing_func_proto(func_id, prog); |
| 1151 | } |
| 1152 | } |
| 1153 | |
| 1154 | static const struct bpf_func_proto * |
| 1155 | tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) |
| 1156 | { |
| 1157 | switch (func_id) { |
| 1158 | #ifdef CONFIG_NET |
| 1159 | case BPF_FUNC_skb_output: |
| 1160 | return &bpf_skb_output_proto; |
| 1161 | #endif |
| 1162 | default: |
| 1163 | return raw_tp_prog_func_proto(func_id, prog); |
| 1164 | } |
| 1165 | } |
| 1166 | |
| 1167 | static bool raw_tp_prog_is_valid_access(int off, int size, |
| 1168 | enum bpf_access_type type, |
| 1169 | const struct bpf_prog *prog, |
| 1170 | struct bpf_insn_access_aux *info) |
| 1171 | { |
| 1172 | if (off < 0 || off >= sizeof(__u64) * MAX_BPF_FUNC_ARGS) |
| 1173 | return false; |
| 1174 | if (type != BPF_READ) |
| 1175 | return false; |
| 1176 | if (off % size != 0) |
| 1177 | return false; |
| 1178 | return true; |
| 1179 | } |
| 1180 | |
| 1181 | static bool tracing_prog_is_valid_access(int off, int size, |
| 1182 | enum bpf_access_type type, |
| 1183 | const struct bpf_prog *prog, |
| 1184 | struct bpf_insn_access_aux *info) |
| 1185 | { |
| 1186 | if (off < 0 || off >= sizeof(__u64) * MAX_BPF_FUNC_ARGS) |
| 1187 | return false; |
| 1188 | if (type != BPF_READ) |
| 1189 | return false; |
| 1190 | if (off % size != 0) |
| 1191 | return false; |
| 1192 | return btf_ctx_access(off, size, type, prog, info); |
| 1193 | } |
| 1194 | |
| 1195 | const struct bpf_verifier_ops raw_tracepoint_verifier_ops = { |
| 1196 | .get_func_proto = raw_tp_prog_func_proto, |
| 1197 | .is_valid_access = raw_tp_prog_is_valid_access, |
| 1198 | }; |
| 1199 | |
| 1200 | const struct bpf_prog_ops raw_tracepoint_prog_ops = { |
| 1201 | }; |
| 1202 | |
| 1203 | const struct bpf_verifier_ops tracing_verifier_ops = { |
| 1204 | .get_func_proto = tracing_prog_func_proto, |
| 1205 | .is_valid_access = tracing_prog_is_valid_access, |
| 1206 | }; |
| 1207 | |
| 1208 | const struct bpf_prog_ops tracing_prog_ops = { |
| 1209 | }; |
| 1210 | |
| 1211 | static bool raw_tp_writable_prog_is_valid_access(int off, int size, |
| 1212 | enum bpf_access_type type, |
| 1213 | const struct bpf_prog *prog, |
| 1214 | struct bpf_insn_access_aux *info) |
| 1215 | { |
| 1216 | if (off == 0) { |
| 1217 | if (size != sizeof(u64) || type != BPF_READ) |
| 1218 | return false; |
| 1219 | info->reg_type = PTR_TO_TP_BUFFER; |
| 1220 | } |
| 1221 | return raw_tp_prog_is_valid_access(off, size, type, prog, info); |
| 1222 | } |
| 1223 | |
| 1224 | const struct bpf_verifier_ops raw_tracepoint_writable_verifier_ops = { |
| 1225 | .get_func_proto = raw_tp_prog_func_proto, |
| 1226 | .is_valid_access = raw_tp_writable_prog_is_valid_access, |
| 1227 | }; |
| 1228 | |
| 1229 | const struct bpf_prog_ops raw_tracepoint_writable_prog_ops = { |
| 1230 | }; |
| 1231 | |
| 1232 | static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type, |
| 1233 | const struct bpf_prog *prog, |
| 1234 | struct bpf_insn_access_aux *info) |
| 1235 | { |
| 1236 | const int size_u64 = sizeof(u64); |
| 1237 | |
| 1238 | if (off < 0 || off >= sizeof(struct bpf_perf_event_data)) |
| 1239 | return false; |
| 1240 | if (type != BPF_READ) |
| 1241 | return false; |
| 1242 | if (off % size != 0) { |
| 1243 | if (sizeof(unsigned long) != 4) |
| 1244 | return false; |
| 1245 | if (size != 8) |
| 1246 | return false; |
| 1247 | if (off % size != 4) |
| 1248 | return false; |
| 1249 | } |
| 1250 | |
| 1251 | switch (off) { |
| 1252 | case bpf_ctx_range(struct bpf_perf_event_data, sample_period): |
| 1253 | bpf_ctx_record_field_size(info, size_u64); |
| 1254 | if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) |
| 1255 | return false; |
| 1256 | break; |
| 1257 | case bpf_ctx_range(struct bpf_perf_event_data, addr): |
| 1258 | bpf_ctx_record_field_size(info, size_u64); |
| 1259 | if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) |
| 1260 | return false; |
| 1261 | break; |
| 1262 | default: |
| 1263 | if (size != sizeof(long)) |
| 1264 | return false; |
| 1265 | } |
| 1266 | |
| 1267 | return true; |
| 1268 | } |
| 1269 | |
| 1270 | static u32 pe_prog_convert_ctx_access(enum bpf_access_type type, |
| 1271 | const struct bpf_insn *si, |
| 1272 | struct bpf_insn *insn_buf, |
| 1273 | struct bpf_prog *prog, u32 *target_size) |
| 1274 | { |
| 1275 | struct bpf_insn *insn = insn_buf; |
| 1276 | |
| 1277 | switch (si->off) { |
| 1278 | case offsetof(struct bpf_perf_event_data, sample_period): |
| 1279 | *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, |
| 1280 | data), si->dst_reg, si->src_reg, |
| 1281 | offsetof(struct bpf_perf_event_data_kern, data)); |
| 1282 | *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, |
| 1283 | bpf_target_off(struct perf_sample_data, period, 8, |
| 1284 | target_size)); |
| 1285 | break; |
| 1286 | case offsetof(struct bpf_perf_event_data, addr): |
| 1287 | *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, |
| 1288 | data), si->dst_reg, si->src_reg, |
| 1289 | offsetof(struct bpf_perf_event_data_kern, data)); |
| 1290 | *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, |
| 1291 | bpf_target_off(struct perf_sample_data, addr, 8, |
| 1292 | target_size)); |
| 1293 | break; |
| 1294 | default: |
| 1295 | *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, |
| 1296 | regs), si->dst_reg, si->src_reg, |
| 1297 | offsetof(struct bpf_perf_event_data_kern, regs)); |
| 1298 | *insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg, |
| 1299 | si->off); |
| 1300 | break; |
| 1301 | } |
| 1302 | |
| 1303 | return insn - insn_buf; |
| 1304 | } |
| 1305 | |
| 1306 | const struct bpf_verifier_ops perf_event_verifier_ops = { |
| 1307 | .get_func_proto = pe_prog_func_proto, |
| 1308 | .is_valid_access = pe_prog_is_valid_access, |
| 1309 | .convert_ctx_access = pe_prog_convert_ctx_access, |
| 1310 | }; |
| 1311 | |
| 1312 | const struct bpf_prog_ops perf_event_prog_ops = { |
| 1313 | }; |
| 1314 | |
| 1315 | static DEFINE_MUTEX(bpf_event_mutex); |
| 1316 | |
| 1317 | #define BPF_TRACE_MAX_PROGS 64 |
| 1318 | |
| 1319 | int perf_event_attach_bpf_prog(struct perf_event *event, |
| 1320 | struct bpf_prog *prog) |
| 1321 | { |
| 1322 | struct bpf_prog_array *old_array; |
| 1323 | struct bpf_prog_array *new_array; |
| 1324 | int ret = -EEXIST; |
| 1325 | |
| 1326 | /* |
| 1327 | * Kprobe override only works if they are on the function entry, |
| 1328 | * and only if they are on the opt-in list. |
| 1329 | */ |
| 1330 | if (prog->kprobe_override && |
| 1331 | (!trace_kprobe_on_func_entry(event->tp_event) || |
| 1332 | !trace_kprobe_error_injectable(event->tp_event))) |
| 1333 | return -EINVAL; |
| 1334 | |
| 1335 | mutex_lock(&bpf_event_mutex); |
| 1336 | |
| 1337 | if (event->prog) |
| 1338 | goto unlock; |
| 1339 | |
| 1340 | old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); |
| 1341 | if (old_array && |
| 1342 | bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) { |
| 1343 | ret = -E2BIG; |
| 1344 | goto unlock; |
| 1345 | } |
| 1346 | |
| 1347 | ret = bpf_prog_array_copy(old_array, NULL, prog, &new_array); |
| 1348 | if (ret < 0) |
| 1349 | goto unlock; |
| 1350 | |
| 1351 | /* set the new array to event->tp_event and set event->prog */ |
| 1352 | event->prog = prog; |
| 1353 | rcu_assign_pointer(event->tp_event->prog_array, new_array); |
| 1354 | bpf_prog_array_free(old_array); |
| 1355 | |
| 1356 | unlock: |
| 1357 | mutex_unlock(&bpf_event_mutex); |
| 1358 | return ret; |
| 1359 | } |
| 1360 | |
| 1361 | void perf_event_detach_bpf_prog(struct perf_event *event) |
| 1362 | { |
| 1363 | struct bpf_prog_array *old_array; |
| 1364 | struct bpf_prog_array *new_array; |
| 1365 | int ret; |
| 1366 | |
| 1367 | mutex_lock(&bpf_event_mutex); |
| 1368 | |
| 1369 | if (!event->prog) |
| 1370 | goto unlock; |
| 1371 | |
| 1372 | old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); |
| 1373 | ret = bpf_prog_array_copy(old_array, event->prog, NULL, &new_array); |
| 1374 | if (ret == -ENOENT) |
| 1375 | goto unlock; |
| 1376 | if (ret < 0) { |
| 1377 | bpf_prog_array_delete_safe(old_array, event->prog); |
| 1378 | } else { |
| 1379 | rcu_assign_pointer(event->tp_event->prog_array, new_array); |
| 1380 | bpf_prog_array_free(old_array); |
| 1381 | } |
| 1382 | |
| 1383 | bpf_prog_put(event->prog); |
| 1384 | event->prog = NULL; |
| 1385 | |
| 1386 | unlock: |
| 1387 | mutex_unlock(&bpf_event_mutex); |
| 1388 | } |
| 1389 | |
| 1390 | int perf_event_query_prog_array(struct perf_event *event, void __user *info) |
| 1391 | { |
| 1392 | struct perf_event_query_bpf __user *uquery = info; |
| 1393 | struct perf_event_query_bpf query = {}; |
| 1394 | struct bpf_prog_array *progs; |
| 1395 | u32 *ids, prog_cnt, ids_len; |
| 1396 | int ret; |
| 1397 | |
| 1398 | if (!capable(CAP_SYS_ADMIN)) |
| 1399 | return -EPERM; |
| 1400 | if (event->attr.type != PERF_TYPE_TRACEPOINT) |
| 1401 | return -EINVAL; |
| 1402 | if (copy_from_user(&query, uquery, sizeof(query))) |
| 1403 | return -EFAULT; |
| 1404 | |
| 1405 | ids_len = query.ids_len; |
| 1406 | if (ids_len > BPF_TRACE_MAX_PROGS) |
| 1407 | return -E2BIG; |
| 1408 | ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN); |
| 1409 | if (!ids) |
| 1410 | return -ENOMEM; |
| 1411 | /* |
| 1412 | * The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which |
| 1413 | * is required when user only wants to check for uquery->prog_cnt. |
| 1414 | * There is no need to check for it since the case is handled |
| 1415 | * gracefully in bpf_prog_array_copy_info. |
| 1416 | */ |
| 1417 | |
| 1418 | mutex_lock(&bpf_event_mutex); |
| 1419 | progs = bpf_event_rcu_dereference(event->tp_event->prog_array); |
| 1420 | ret = bpf_prog_array_copy_info(progs, ids, ids_len, &prog_cnt); |
| 1421 | mutex_unlock(&bpf_event_mutex); |
| 1422 | |
| 1423 | if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) || |
| 1424 | copy_to_user(uquery->ids, ids, ids_len * sizeof(u32))) |
| 1425 | ret = -EFAULT; |
| 1426 | |
| 1427 | kfree(ids); |
| 1428 | return ret; |
| 1429 | } |
| 1430 | |
| 1431 | extern struct bpf_raw_event_map __start__bpf_raw_tp[]; |
| 1432 | extern struct bpf_raw_event_map __stop__bpf_raw_tp[]; |
| 1433 | |
| 1434 | struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name) |
| 1435 | { |
| 1436 | struct bpf_raw_event_map *btp = __start__bpf_raw_tp; |
| 1437 | |
| 1438 | for (; btp < __stop__bpf_raw_tp; btp++) { |
| 1439 | if (!strcmp(btp->tp->name, name)) |
| 1440 | return btp; |
| 1441 | } |
| 1442 | |
| 1443 | return bpf_get_raw_tracepoint_module(name); |
| 1444 | } |
| 1445 | |
| 1446 | void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp) |
| 1447 | { |
| 1448 | struct module *mod = __module_address((unsigned long)btp); |
| 1449 | |
| 1450 | if (mod) |
| 1451 | module_put(mod); |
| 1452 | } |
| 1453 | |
| 1454 | static __always_inline |
| 1455 | void __bpf_trace_run(struct bpf_prog *prog, u64 *args) |
| 1456 | { |
| 1457 | rcu_read_lock(); |
| 1458 | preempt_disable(); |
| 1459 | (void) BPF_PROG_RUN(prog, args); |
| 1460 | preempt_enable(); |
| 1461 | rcu_read_unlock(); |
| 1462 | } |
| 1463 | |
| 1464 | #define UNPACK(...) __VA_ARGS__ |
| 1465 | #define REPEAT_1(FN, DL, X, ...) FN(X) |
| 1466 | #define REPEAT_2(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__) |
| 1467 | #define REPEAT_3(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_2(FN, DL, __VA_ARGS__) |
| 1468 | #define REPEAT_4(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_3(FN, DL, __VA_ARGS__) |
| 1469 | #define REPEAT_5(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_4(FN, DL, __VA_ARGS__) |
| 1470 | #define REPEAT_6(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_5(FN, DL, __VA_ARGS__) |
| 1471 | #define REPEAT_7(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_6(FN, DL, __VA_ARGS__) |
| 1472 | #define REPEAT_8(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_7(FN, DL, __VA_ARGS__) |
| 1473 | #define REPEAT_9(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_8(FN, DL, __VA_ARGS__) |
| 1474 | #define REPEAT_10(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_9(FN, DL, __VA_ARGS__) |
| 1475 | #define REPEAT_11(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_10(FN, DL, __VA_ARGS__) |
| 1476 | #define REPEAT_12(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_11(FN, DL, __VA_ARGS__) |
| 1477 | #define REPEAT(X, FN, DL, ...) REPEAT_##X(FN, DL, __VA_ARGS__) |
| 1478 | |
| 1479 | #define SARG(X) u64 arg##X |
| 1480 | #define COPY(X) args[X] = arg##X |
| 1481 | |
| 1482 | #define __DL_COM (,) |
| 1483 | #define __DL_SEM (;) |
| 1484 | |
| 1485 | #define __SEQ_0_11 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 |
| 1486 | |
| 1487 | #define BPF_TRACE_DEFN_x(x) \ |
| 1488 | void bpf_trace_run##x(struct bpf_prog *prog, \ |
| 1489 | REPEAT(x, SARG, __DL_COM, __SEQ_0_11)) \ |
| 1490 | { \ |
| 1491 | u64 args[x]; \ |
| 1492 | REPEAT(x, COPY, __DL_SEM, __SEQ_0_11); \ |
| 1493 | __bpf_trace_run(prog, args); \ |
| 1494 | } \ |
| 1495 | EXPORT_SYMBOL_GPL(bpf_trace_run##x) |
| 1496 | BPF_TRACE_DEFN_x(1); |
| 1497 | BPF_TRACE_DEFN_x(2); |
| 1498 | BPF_TRACE_DEFN_x(3); |
| 1499 | BPF_TRACE_DEFN_x(4); |
| 1500 | BPF_TRACE_DEFN_x(5); |
| 1501 | BPF_TRACE_DEFN_x(6); |
| 1502 | BPF_TRACE_DEFN_x(7); |
| 1503 | BPF_TRACE_DEFN_x(8); |
| 1504 | BPF_TRACE_DEFN_x(9); |
| 1505 | BPF_TRACE_DEFN_x(10); |
| 1506 | BPF_TRACE_DEFN_x(11); |
| 1507 | BPF_TRACE_DEFN_x(12); |
| 1508 | |
| 1509 | static int __bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog) |
| 1510 | { |
| 1511 | struct tracepoint *tp = btp->tp; |
| 1512 | |
| 1513 | /* |
| 1514 | * check that program doesn't access arguments beyond what's |
| 1515 | * available in this tracepoint |
| 1516 | */ |
| 1517 | if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64)) |
| 1518 | return -EINVAL; |
| 1519 | |
| 1520 | if (prog->aux->max_tp_access > btp->writable_size) |
| 1521 | return -EINVAL; |
| 1522 | |
| 1523 | return tracepoint_probe_register(tp, (void *)btp->bpf_func, prog); |
| 1524 | } |
| 1525 | |
| 1526 | int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog) |
| 1527 | { |
| 1528 | return __bpf_probe_register(btp, prog); |
| 1529 | } |
| 1530 | |
| 1531 | int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_prog *prog) |
| 1532 | { |
| 1533 | return tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, prog); |
| 1534 | } |
| 1535 | |
| 1536 | int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id, |
| 1537 | u32 *fd_type, const char **buf, |
| 1538 | u64 *probe_offset, u64 *probe_addr) |
| 1539 | { |
| 1540 | bool is_tracepoint, is_syscall_tp; |
| 1541 | struct bpf_prog *prog; |
| 1542 | int flags, err = 0; |
| 1543 | |
| 1544 | prog = event->prog; |
| 1545 | if (!prog) |
| 1546 | return -ENOENT; |
| 1547 | |
| 1548 | /* not supporting BPF_PROG_TYPE_PERF_EVENT yet */ |
| 1549 | if (prog->type == BPF_PROG_TYPE_PERF_EVENT) |
| 1550 | return -EOPNOTSUPP; |
| 1551 | |
| 1552 | *prog_id = prog->aux->id; |
| 1553 | flags = event->tp_event->flags; |
| 1554 | is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT; |
| 1555 | is_syscall_tp = is_syscall_trace_event(event->tp_event); |
| 1556 | |
| 1557 | if (is_tracepoint || is_syscall_tp) { |
| 1558 | *buf = is_tracepoint ? event->tp_event->tp->name |
| 1559 | : event->tp_event->name; |
| 1560 | *fd_type = BPF_FD_TYPE_TRACEPOINT; |
| 1561 | *probe_offset = 0x0; |
| 1562 | *probe_addr = 0x0; |
| 1563 | } else { |
| 1564 | /* kprobe/uprobe */ |
| 1565 | err = -EOPNOTSUPP; |
| 1566 | #ifdef CONFIG_KPROBE_EVENTS |
| 1567 | if (flags & TRACE_EVENT_FL_KPROBE) |
| 1568 | err = bpf_get_kprobe_info(event, fd_type, buf, |
| 1569 | probe_offset, probe_addr, |
| 1570 | event->attr.type == PERF_TYPE_TRACEPOINT); |
| 1571 | #endif |
| 1572 | #ifdef CONFIG_UPROBE_EVENTS |
| 1573 | if (flags & TRACE_EVENT_FL_UPROBE) |
| 1574 | err = bpf_get_uprobe_info(event, fd_type, buf, |
| 1575 | probe_offset, |
| 1576 | event->attr.type == PERF_TYPE_TRACEPOINT); |
| 1577 | #endif |
| 1578 | } |
| 1579 | |
| 1580 | return err; |
| 1581 | } |
| 1582 | |
| 1583 | static int __init send_signal_irq_work_init(void) |
| 1584 | { |
| 1585 | int cpu; |
| 1586 | struct send_signal_irq_work *work; |
| 1587 | |
| 1588 | for_each_possible_cpu(cpu) { |
| 1589 | work = per_cpu_ptr(&send_signal_work, cpu); |
| 1590 | init_irq_work(&work->irq_work, do_bpf_send_signal); |
| 1591 | } |
| 1592 | return 0; |
| 1593 | } |
| 1594 | |
| 1595 | subsys_initcall(send_signal_irq_work_init); |
| 1596 | |
| 1597 | #ifdef CONFIG_MODULES |
| 1598 | static int bpf_event_notify(struct notifier_block *nb, unsigned long op, |
| 1599 | void *module) |
| 1600 | { |
| 1601 | struct bpf_trace_module *btm, *tmp; |
| 1602 | struct module *mod = module; |
| 1603 | |
| 1604 | if (mod->num_bpf_raw_events == 0 || |
| 1605 | (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING)) |
| 1606 | return 0; |
| 1607 | |
| 1608 | mutex_lock(&bpf_module_mutex); |
| 1609 | |
| 1610 | switch (op) { |
| 1611 | case MODULE_STATE_COMING: |
| 1612 | btm = kzalloc(sizeof(*btm), GFP_KERNEL); |
| 1613 | if (btm) { |
| 1614 | btm->module = module; |
| 1615 | list_add(&btm->list, &bpf_trace_modules); |
| 1616 | } |
| 1617 | break; |
| 1618 | case MODULE_STATE_GOING: |
| 1619 | list_for_each_entry_safe(btm, tmp, &bpf_trace_modules, list) { |
| 1620 | if (btm->module == module) { |
| 1621 | list_del(&btm->list); |
| 1622 | kfree(btm); |
| 1623 | break; |
| 1624 | } |
| 1625 | } |
| 1626 | break; |
| 1627 | } |
| 1628 | |
| 1629 | mutex_unlock(&bpf_module_mutex); |
| 1630 | |
| 1631 | return 0; |
| 1632 | } |
| 1633 | |
| 1634 | static struct notifier_block bpf_module_nb = { |
| 1635 | .notifier_call = bpf_event_notify, |
| 1636 | }; |
| 1637 | |
| 1638 | static int __init bpf_event_init(void) |
| 1639 | { |
| 1640 | register_module_notifier(&bpf_module_nb); |
| 1641 | return 0; |
| 1642 | } |
| 1643 | |
| 1644 | fs_initcall(bpf_event_init); |
| 1645 | #endif /* CONFIG_MODULES */ |