| 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_verifier.h> |
| 10 | #include <linux/bpf_perf_event.h> |
| 11 | #include <linux/btf.h> |
| 12 | #include <linux/filter.h> |
| 13 | #include <linux/uaccess.h> |
| 14 | #include <linux/ctype.h> |
| 15 | #include <linux/kprobes.h> |
| 16 | #include <linux/spinlock.h> |
| 17 | #include <linux/syscalls.h> |
| 18 | #include <linux/error-injection.h> |
| 19 | #include <linux/btf_ids.h> |
| 20 | #include <linux/bpf_lsm.h> |
| 21 | #include <linux/fprobe.h> |
| 22 | #include <linux/bsearch.h> |
| 23 | #include <linux/sort.h> |
| 24 | #include <linux/key.h> |
| 25 | #include <linux/verification.h> |
| 26 | #include <linux/namei.h> |
| 27 | |
| 28 | #include <net/bpf_sk_storage.h> |
| 29 | |
| 30 | #include <uapi/linux/bpf.h> |
| 31 | #include <uapi/linux/btf.h> |
| 32 | |
| 33 | #include <asm/tlb.h> |
| 34 | |
| 35 | #include "trace_probe.h" |
| 36 | #include "trace.h" |
| 37 | |
| 38 | #define CREATE_TRACE_POINTS |
| 39 | #include "bpf_trace.h" |
| 40 | |
| 41 | #define bpf_event_rcu_dereference(p) \ |
| 42 | rcu_dereference_protected(p, lockdep_is_held(&bpf_event_mutex)) |
| 43 | |
| 44 | #define MAX_UPROBE_MULTI_CNT (1U << 20) |
| 45 | #define MAX_KPROBE_MULTI_CNT (1U << 20) |
| 46 | |
| 47 | #ifdef CONFIG_MODULES |
| 48 | struct bpf_trace_module { |
| 49 | struct module *module; |
| 50 | struct list_head list; |
| 51 | }; |
| 52 | |
| 53 | static LIST_HEAD(bpf_trace_modules); |
| 54 | static DEFINE_MUTEX(bpf_module_mutex); |
| 55 | |
| 56 | static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name) |
| 57 | { |
| 58 | struct bpf_raw_event_map *btp, *ret = NULL; |
| 59 | struct bpf_trace_module *btm; |
| 60 | unsigned int i; |
| 61 | |
| 62 | mutex_lock(&bpf_module_mutex); |
| 63 | list_for_each_entry(btm, &bpf_trace_modules, list) { |
| 64 | for (i = 0; i < btm->module->num_bpf_raw_events; ++i) { |
| 65 | btp = &btm->module->bpf_raw_events[i]; |
| 66 | if (!strcmp(btp->tp->name, name)) { |
| 67 | if (try_module_get(btm->module)) |
| 68 | ret = btp; |
| 69 | goto out; |
| 70 | } |
| 71 | } |
| 72 | } |
| 73 | out: |
| 74 | mutex_unlock(&bpf_module_mutex); |
| 75 | return ret; |
| 76 | } |
| 77 | #else |
| 78 | static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name) |
| 79 | { |
| 80 | return NULL; |
| 81 | } |
| 82 | #endif /* CONFIG_MODULES */ |
| 83 | |
| 84 | u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); |
| 85 | u64 bpf_get_stack(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); |
| 86 | |
| 87 | static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size, |
| 88 | u64 flags, const struct btf **btf, |
| 89 | s32 *btf_id); |
| 90 | static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx); |
| 91 | static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx); |
| 92 | |
| 93 | static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx); |
| 94 | static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx); |
| 95 | |
| 96 | /** |
| 97 | * trace_call_bpf - invoke BPF program |
| 98 | * @call: tracepoint event |
| 99 | * @ctx: opaque context pointer |
| 100 | * |
| 101 | * kprobe handlers execute BPF programs via this helper. |
| 102 | * Can be used from static tracepoints in the future. |
| 103 | * |
| 104 | * Return: BPF programs always return an integer which is interpreted by |
| 105 | * kprobe handler as: |
| 106 | * 0 - return from kprobe (event is filtered out) |
| 107 | * 1 - store kprobe event into ring buffer |
| 108 | * Other values are reserved and currently alias to 1 |
| 109 | */ |
| 110 | unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx) |
| 111 | { |
| 112 | unsigned int ret; |
| 113 | |
| 114 | cant_sleep(); |
| 115 | |
| 116 | if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) { |
| 117 | /* |
| 118 | * since some bpf program is already running on this cpu, |
| 119 | * don't call into another bpf program (same or different) |
| 120 | * and don't send kprobe event into ring-buffer, |
| 121 | * so return zero here |
| 122 | */ |
| 123 | rcu_read_lock(); |
| 124 | bpf_prog_inc_misses_counters(rcu_dereference(call->prog_array)); |
| 125 | rcu_read_unlock(); |
| 126 | ret = 0; |
| 127 | goto out; |
| 128 | } |
| 129 | |
| 130 | /* |
| 131 | * Instead of moving rcu_read_lock/rcu_dereference/rcu_read_unlock |
| 132 | * to all call sites, we did a bpf_prog_array_valid() there to check |
| 133 | * whether call->prog_array is empty or not, which is |
| 134 | * a heuristic to speed up execution. |
| 135 | * |
| 136 | * If bpf_prog_array_valid() fetched prog_array was |
| 137 | * non-NULL, we go into trace_call_bpf() and do the actual |
| 138 | * proper rcu_dereference() under RCU lock. |
| 139 | * If it turns out that prog_array is NULL then, we bail out. |
| 140 | * For the opposite, if the bpf_prog_array_valid() fetched pointer |
| 141 | * was NULL, you'll skip the prog_array with the risk of missing |
| 142 | * out of events when it was updated in between this and the |
| 143 | * rcu_dereference() which is accepted risk. |
| 144 | */ |
| 145 | rcu_read_lock(); |
| 146 | ret = bpf_prog_run_array(rcu_dereference(call->prog_array), |
| 147 | ctx, bpf_prog_run); |
| 148 | rcu_read_unlock(); |
| 149 | |
| 150 | out: |
| 151 | __this_cpu_dec(bpf_prog_active); |
| 152 | |
| 153 | return ret; |
| 154 | } |
| 155 | |
| 156 | #ifdef CONFIG_BPF_KPROBE_OVERRIDE |
| 157 | BPF_CALL_2(bpf_override_return, struct pt_regs *, regs, unsigned long, rc) |
| 158 | { |
| 159 | regs_set_return_value(regs, rc); |
| 160 | override_function_with_return(regs); |
| 161 | return 0; |
| 162 | } |
| 163 | |
| 164 | static const struct bpf_func_proto bpf_override_return_proto = { |
| 165 | .func = bpf_override_return, |
| 166 | .gpl_only = true, |
| 167 | .ret_type = RET_INTEGER, |
| 168 | .arg1_type = ARG_PTR_TO_CTX, |
| 169 | .arg2_type = ARG_ANYTHING, |
| 170 | }; |
| 171 | #endif |
| 172 | |
| 173 | static __always_inline int |
| 174 | bpf_probe_read_user_common(void *dst, u32 size, const void __user *unsafe_ptr) |
| 175 | { |
| 176 | int ret; |
| 177 | |
| 178 | ret = copy_from_user_nofault(dst, unsafe_ptr, size); |
| 179 | if (unlikely(ret < 0)) |
| 180 | memset(dst, 0, size); |
| 181 | return ret; |
| 182 | } |
| 183 | |
| 184 | BPF_CALL_3(bpf_probe_read_user, void *, dst, u32, size, |
| 185 | const void __user *, unsafe_ptr) |
| 186 | { |
| 187 | return bpf_probe_read_user_common(dst, size, unsafe_ptr); |
| 188 | } |
| 189 | |
| 190 | const struct bpf_func_proto bpf_probe_read_user_proto = { |
| 191 | .func = bpf_probe_read_user, |
| 192 | .gpl_only = true, |
| 193 | .ret_type = RET_INTEGER, |
| 194 | .arg1_type = ARG_PTR_TO_UNINIT_MEM, |
| 195 | .arg2_type = ARG_CONST_SIZE_OR_ZERO, |
| 196 | .arg3_type = ARG_ANYTHING, |
| 197 | }; |
| 198 | |
| 199 | static __always_inline int |
| 200 | bpf_probe_read_user_str_common(void *dst, u32 size, |
| 201 | const void __user *unsafe_ptr) |
| 202 | { |
| 203 | int ret; |
| 204 | |
| 205 | /* |
| 206 | * NB: We rely on strncpy_from_user() not copying junk past the NUL |
| 207 | * terminator into `dst`. |
| 208 | * |
| 209 | * strncpy_from_user() does long-sized strides in the fast path. If the |
| 210 | * strncpy does not mask out the bytes after the NUL in `unsafe_ptr`, |
| 211 | * then there could be junk after the NUL in `dst`. If user takes `dst` |
| 212 | * and keys a hash map with it, then semantically identical strings can |
| 213 | * occupy multiple entries in the map. |
| 214 | */ |
| 215 | ret = strncpy_from_user_nofault(dst, unsafe_ptr, size); |
| 216 | if (unlikely(ret < 0)) |
| 217 | memset(dst, 0, size); |
| 218 | return ret; |
| 219 | } |
| 220 | |
| 221 | BPF_CALL_3(bpf_probe_read_user_str, void *, dst, u32, size, |
| 222 | const void __user *, unsafe_ptr) |
| 223 | { |
| 224 | return bpf_probe_read_user_str_common(dst, size, unsafe_ptr); |
| 225 | } |
| 226 | |
| 227 | const struct bpf_func_proto bpf_probe_read_user_str_proto = { |
| 228 | .func = bpf_probe_read_user_str, |
| 229 | .gpl_only = true, |
| 230 | .ret_type = RET_INTEGER, |
| 231 | .arg1_type = ARG_PTR_TO_UNINIT_MEM, |
| 232 | .arg2_type = ARG_CONST_SIZE_OR_ZERO, |
| 233 | .arg3_type = ARG_ANYTHING, |
| 234 | }; |
| 235 | |
| 236 | BPF_CALL_3(bpf_probe_read_kernel, void *, dst, u32, size, |
| 237 | const void *, unsafe_ptr) |
| 238 | { |
| 239 | return bpf_probe_read_kernel_common(dst, size, unsafe_ptr); |
| 240 | } |
| 241 | |
| 242 | const struct bpf_func_proto bpf_probe_read_kernel_proto = { |
| 243 | .func = bpf_probe_read_kernel, |
| 244 | .gpl_only = true, |
| 245 | .ret_type = RET_INTEGER, |
| 246 | .arg1_type = ARG_PTR_TO_UNINIT_MEM, |
| 247 | .arg2_type = ARG_CONST_SIZE_OR_ZERO, |
| 248 | .arg3_type = ARG_ANYTHING, |
| 249 | }; |
| 250 | |
| 251 | static __always_inline int |
| 252 | bpf_probe_read_kernel_str_common(void *dst, u32 size, const void *unsafe_ptr) |
| 253 | { |
| 254 | int ret; |
| 255 | |
| 256 | /* |
| 257 | * The strncpy_from_kernel_nofault() call will likely not fill the |
| 258 | * entire buffer, but that's okay in this circumstance as we're probing |
| 259 | * arbitrary memory anyway similar to bpf_probe_read_*() and might |
| 260 | * as well probe the stack. Thus, memory is explicitly cleared |
| 261 | * only in error case, so that improper users ignoring return |
| 262 | * code altogether don't copy garbage; otherwise length of string |
| 263 | * is returned that can be used for bpf_perf_event_output() et al. |
| 264 | */ |
| 265 | ret = strncpy_from_kernel_nofault(dst, unsafe_ptr, size); |
| 266 | if (unlikely(ret < 0)) |
| 267 | memset(dst, 0, size); |
| 268 | return ret; |
| 269 | } |
| 270 | |
| 271 | BPF_CALL_3(bpf_probe_read_kernel_str, void *, dst, u32, size, |
| 272 | const void *, unsafe_ptr) |
| 273 | { |
| 274 | return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr); |
| 275 | } |
| 276 | |
| 277 | const struct bpf_func_proto bpf_probe_read_kernel_str_proto = { |
| 278 | .func = bpf_probe_read_kernel_str, |
| 279 | .gpl_only = true, |
| 280 | .ret_type = RET_INTEGER, |
| 281 | .arg1_type = ARG_PTR_TO_UNINIT_MEM, |
| 282 | .arg2_type = ARG_CONST_SIZE_OR_ZERO, |
| 283 | .arg3_type = ARG_ANYTHING, |
| 284 | }; |
| 285 | |
| 286 | #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE |
| 287 | BPF_CALL_3(bpf_probe_read_compat, void *, dst, u32, size, |
| 288 | const void *, unsafe_ptr) |
| 289 | { |
| 290 | if ((unsigned long)unsafe_ptr < TASK_SIZE) { |
| 291 | return bpf_probe_read_user_common(dst, size, |
| 292 | (__force void __user *)unsafe_ptr); |
| 293 | } |
| 294 | return bpf_probe_read_kernel_common(dst, size, unsafe_ptr); |
| 295 | } |
| 296 | |
| 297 | static const struct bpf_func_proto bpf_probe_read_compat_proto = { |
| 298 | .func = bpf_probe_read_compat, |
| 299 | .gpl_only = true, |
| 300 | .ret_type = RET_INTEGER, |
| 301 | .arg1_type = ARG_PTR_TO_UNINIT_MEM, |
| 302 | .arg2_type = ARG_CONST_SIZE_OR_ZERO, |
| 303 | .arg3_type = ARG_ANYTHING, |
| 304 | }; |
| 305 | |
| 306 | BPF_CALL_3(bpf_probe_read_compat_str, void *, dst, u32, size, |
| 307 | const void *, unsafe_ptr) |
| 308 | { |
| 309 | if ((unsigned long)unsafe_ptr < TASK_SIZE) { |
| 310 | return bpf_probe_read_user_str_common(dst, size, |
| 311 | (__force void __user *)unsafe_ptr); |
| 312 | } |
| 313 | return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr); |
| 314 | } |
| 315 | |
| 316 | static const struct bpf_func_proto bpf_probe_read_compat_str_proto = { |
| 317 | .func = bpf_probe_read_compat_str, |
| 318 | .gpl_only = true, |
| 319 | .ret_type = RET_INTEGER, |
| 320 | .arg1_type = ARG_PTR_TO_UNINIT_MEM, |
| 321 | .arg2_type = ARG_CONST_SIZE_OR_ZERO, |
| 322 | .arg3_type = ARG_ANYTHING, |
| 323 | }; |
| 324 | #endif /* CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE */ |
| 325 | |
| 326 | BPF_CALL_3(bpf_probe_write_user, void __user *, unsafe_ptr, const void *, src, |
| 327 | u32, size) |
| 328 | { |
| 329 | /* |
| 330 | * Ensure we're in user context which is safe for the helper to |
| 331 | * run. This helper has no business in a kthread. |
| 332 | * |
| 333 | * access_ok() should prevent writing to non-user memory, but in |
| 334 | * some situations (nommu, temporary switch, etc) access_ok() does |
| 335 | * not provide enough validation, hence the check on KERNEL_DS. |
| 336 | * |
| 337 | * nmi_uaccess_okay() ensures the probe is not run in an interim |
| 338 | * state, when the task or mm are switched. This is specifically |
| 339 | * required to prevent the use of temporary mm. |
| 340 | */ |
| 341 | |
| 342 | if (unlikely(in_interrupt() || |
| 343 | current->flags & (PF_KTHREAD | PF_EXITING))) |
| 344 | return -EPERM; |
| 345 | if (unlikely(!nmi_uaccess_okay())) |
| 346 | return -EPERM; |
| 347 | |
| 348 | return copy_to_user_nofault(unsafe_ptr, src, size); |
| 349 | } |
| 350 | |
| 351 | static const struct bpf_func_proto bpf_probe_write_user_proto = { |
| 352 | .func = bpf_probe_write_user, |
| 353 | .gpl_only = true, |
| 354 | .ret_type = RET_INTEGER, |
| 355 | .arg1_type = ARG_ANYTHING, |
| 356 | .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, |
| 357 | .arg3_type = ARG_CONST_SIZE, |
| 358 | }; |
| 359 | |
| 360 | #define MAX_TRACE_PRINTK_VARARGS 3 |
| 361 | #define BPF_TRACE_PRINTK_SIZE 1024 |
| 362 | |
| 363 | BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1, |
| 364 | u64, arg2, u64, arg3) |
| 365 | { |
| 366 | u64 args[MAX_TRACE_PRINTK_VARARGS] = { arg1, arg2, arg3 }; |
| 367 | struct bpf_bprintf_data data = { |
| 368 | .get_bin_args = true, |
| 369 | .get_buf = true, |
| 370 | }; |
| 371 | int ret; |
| 372 | |
| 373 | ret = bpf_bprintf_prepare(fmt, fmt_size, args, |
| 374 | MAX_TRACE_PRINTK_VARARGS, &data); |
| 375 | if (ret < 0) |
| 376 | return ret; |
| 377 | |
| 378 | ret = bstr_printf(data.buf, MAX_BPRINTF_BUF, fmt, data.bin_args); |
| 379 | |
| 380 | trace_bpf_trace_printk(data.buf); |
| 381 | |
| 382 | bpf_bprintf_cleanup(&data); |
| 383 | |
| 384 | return ret; |
| 385 | } |
| 386 | |
| 387 | static const struct bpf_func_proto bpf_trace_printk_proto = { |
| 388 | .func = bpf_trace_printk, |
| 389 | .gpl_only = true, |
| 390 | .ret_type = RET_INTEGER, |
| 391 | .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY, |
| 392 | .arg2_type = ARG_CONST_SIZE, |
| 393 | }; |
| 394 | |
| 395 | static void __set_printk_clr_event(struct work_struct *work) |
| 396 | { |
| 397 | /* |
| 398 | * This program might be calling bpf_trace_printk, |
| 399 | * so enable the associated bpf_trace/bpf_trace_printk event. |
| 400 | * Repeat this each time as it is possible a user has |
| 401 | * disabled bpf_trace_printk events. By loading a program |
| 402 | * calling bpf_trace_printk() however the user has expressed |
| 403 | * the intent to see such events. |
| 404 | */ |
| 405 | if (trace_set_clr_event("bpf_trace", "bpf_trace_printk", 1)) |
| 406 | pr_warn_ratelimited("could not enable bpf_trace_printk events"); |
| 407 | } |
| 408 | static DECLARE_WORK(set_printk_work, __set_printk_clr_event); |
| 409 | |
| 410 | const struct bpf_func_proto *bpf_get_trace_printk_proto(void) |
| 411 | { |
| 412 | schedule_work(&set_printk_work); |
| 413 | return &bpf_trace_printk_proto; |
| 414 | } |
| 415 | |
| 416 | BPF_CALL_4(bpf_trace_vprintk, char *, fmt, u32, fmt_size, const void *, args, |
| 417 | u32, data_len) |
| 418 | { |
| 419 | struct bpf_bprintf_data data = { |
| 420 | .get_bin_args = true, |
| 421 | .get_buf = true, |
| 422 | }; |
| 423 | int ret, num_args; |
| 424 | |
| 425 | if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 || |
| 426 | (data_len && !args)) |
| 427 | return -EINVAL; |
| 428 | num_args = data_len / 8; |
| 429 | |
| 430 | ret = bpf_bprintf_prepare(fmt, fmt_size, args, num_args, &data); |
| 431 | if (ret < 0) |
| 432 | return ret; |
| 433 | |
| 434 | ret = bstr_printf(data.buf, MAX_BPRINTF_BUF, fmt, data.bin_args); |
| 435 | |
| 436 | trace_bpf_trace_printk(data.buf); |
| 437 | |
| 438 | bpf_bprintf_cleanup(&data); |
| 439 | |
| 440 | return ret; |
| 441 | } |
| 442 | |
| 443 | static const struct bpf_func_proto bpf_trace_vprintk_proto = { |
| 444 | .func = bpf_trace_vprintk, |
| 445 | .gpl_only = true, |
| 446 | .ret_type = RET_INTEGER, |
| 447 | .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY, |
| 448 | .arg2_type = ARG_CONST_SIZE, |
| 449 | .arg3_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY, |
| 450 | .arg4_type = ARG_CONST_SIZE_OR_ZERO, |
| 451 | }; |
| 452 | |
| 453 | const struct bpf_func_proto *bpf_get_trace_vprintk_proto(void) |
| 454 | { |
| 455 | schedule_work(&set_printk_work); |
| 456 | return &bpf_trace_vprintk_proto; |
| 457 | } |
| 458 | |
| 459 | BPF_CALL_5(bpf_seq_printf, struct seq_file *, m, char *, fmt, u32, fmt_size, |
| 460 | const void *, args, u32, data_len) |
| 461 | { |
| 462 | struct bpf_bprintf_data data = { |
| 463 | .get_bin_args = true, |
| 464 | }; |
| 465 | int err, num_args; |
| 466 | |
| 467 | if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 || |
| 468 | (data_len && !args)) |
| 469 | return -EINVAL; |
| 470 | num_args = data_len / 8; |
| 471 | |
| 472 | err = bpf_bprintf_prepare(fmt, fmt_size, args, num_args, &data); |
| 473 | if (err < 0) |
| 474 | return err; |
| 475 | |
| 476 | seq_bprintf(m, fmt, data.bin_args); |
| 477 | |
| 478 | bpf_bprintf_cleanup(&data); |
| 479 | |
| 480 | return seq_has_overflowed(m) ? -EOVERFLOW : 0; |
| 481 | } |
| 482 | |
| 483 | BTF_ID_LIST_SINGLE(btf_seq_file_ids, struct, seq_file) |
| 484 | |
| 485 | static const struct bpf_func_proto bpf_seq_printf_proto = { |
| 486 | .func = bpf_seq_printf, |
| 487 | .gpl_only = true, |
| 488 | .ret_type = RET_INTEGER, |
| 489 | .arg1_type = ARG_PTR_TO_BTF_ID, |
| 490 | .arg1_btf_id = &btf_seq_file_ids[0], |
| 491 | .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, |
| 492 | .arg3_type = ARG_CONST_SIZE, |
| 493 | .arg4_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY, |
| 494 | .arg5_type = ARG_CONST_SIZE_OR_ZERO, |
| 495 | }; |
| 496 | |
| 497 | BPF_CALL_3(bpf_seq_write, struct seq_file *, m, const void *, data, u32, len) |
| 498 | { |
| 499 | return seq_write(m, data, len) ? -EOVERFLOW : 0; |
| 500 | } |
| 501 | |
| 502 | static const struct bpf_func_proto bpf_seq_write_proto = { |
| 503 | .func = bpf_seq_write, |
| 504 | .gpl_only = true, |
| 505 | .ret_type = RET_INTEGER, |
| 506 | .arg1_type = ARG_PTR_TO_BTF_ID, |
| 507 | .arg1_btf_id = &btf_seq_file_ids[0], |
| 508 | .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, |
| 509 | .arg3_type = ARG_CONST_SIZE_OR_ZERO, |
| 510 | }; |
| 511 | |
| 512 | BPF_CALL_4(bpf_seq_printf_btf, struct seq_file *, m, struct btf_ptr *, ptr, |
| 513 | u32, btf_ptr_size, u64, flags) |
| 514 | { |
| 515 | const struct btf *btf; |
| 516 | s32 btf_id; |
| 517 | int ret; |
| 518 | |
| 519 | ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id); |
| 520 | if (ret) |
| 521 | return ret; |
| 522 | |
| 523 | return btf_type_seq_show_flags(btf, btf_id, ptr->ptr, m, flags); |
| 524 | } |
| 525 | |
| 526 | static const struct bpf_func_proto bpf_seq_printf_btf_proto = { |
| 527 | .func = bpf_seq_printf_btf, |
| 528 | .gpl_only = true, |
| 529 | .ret_type = RET_INTEGER, |
| 530 | .arg1_type = ARG_PTR_TO_BTF_ID, |
| 531 | .arg1_btf_id = &btf_seq_file_ids[0], |
| 532 | .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, |
| 533 | .arg3_type = ARG_CONST_SIZE_OR_ZERO, |
| 534 | .arg4_type = ARG_ANYTHING, |
| 535 | }; |
| 536 | |
| 537 | static __always_inline int |
| 538 | get_map_perf_counter(struct bpf_map *map, u64 flags, |
| 539 | u64 *value, u64 *enabled, u64 *running) |
| 540 | { |
| 541 | struct bpf_array *array = container_of(map, struct bpf_array, map); |
| 542 | unsigned int cpu = smp_processor_id(); |
| 543 | u64 index = flags & BPF_F_INDEX_MASK; |
| 544 | struct bpf_event_entry *ee; |
| 545 | |
| 546 | if (unlikely(flags & ~(BPF_F_INDEX_MASK))) |
| 547 | return -EINVAL; |
| 548 | if (index == BPF_F_CURRENT_CPU) |
| 549 | index = cpu; |
| 550 | if (unlikely(index >= array->map.max_entries)) |
| 551 | return -E2BIG; |
| 552 | |
| 553 | ee = READ_ONCE(array->ptrs[index]); |
| 554 | if (!ee) |
| 555 | return -ENOENT; |
| 556 | |
| 557 | return perf_event_read_local(ee->event, value, enabled, running); |
| 558 | } |
| 559 | |
| 560 | BPF_CALL_2(bpf_perf_event_read, struct bpf_map *, map, u64, flags) |
| 561 | { |
| 562 | u64 value = 0; |
| 563 | int err; |
| 564 | |
| 565 | err = get_map_perf_counter(map, flags, &value, NULL, NULL); |
| 566 | /* |
| 567 | * this api is ugly since we miss [-22..-2] range of valid |
| 568 | * counter values, but that's uapi |
| 569 | */ |
| 570 | if (err) |
| 571 | return err; |
| 572 | return value; |
| 573 | } |
| 574 | |
| 575 | const struct bpf_func_proto bpf_perf_event_read_proto = { |
| 576 | .func = bpf_perf_event_read, |
| 577 | .gpl_only = true, |
| 578 | .ret_type = RET_INTEGER, |
| 579 | .arg1_type = ARG_CONST_MAP_PTR, |
| 580 | .arg2_type = ARG_ANYTHING, |
| 581 | }; |
| 582 | |
| 583 | BPF_CALL_4(bpf_perf_event_read_value, struct bpf_map *, map, u64, flags, |
| 584 | struct bpf_perf_event_value *, buf, u32, size) |
| 585 | { |
| 586 | int err = -EINVAL; |
| 587 | |
| 588 | if (unlikely(size != sizeof(struct bpf_perf_event_value))) |
| 589 | goto clear; |
| 590 | err = get_map_perf_counter(map, flags, &buf->counter, &buf->enabled, |
| 591 | &buf->running); |
| 592 | if (unlikely(err)) |
| 593 | goto clear; |
| 594 | return 0; |
| 595 | clear: |
| 596 | memset(buf, 0, size); |
| 597 | return err; |
| 598 | } |
| 599 | |
| 600 | static const struct bpf_func_proto bpf_perf_event_read_value_proto = { |
| 601 | .func = bpf_perf_event_read_value, |
| 602 | .gpl_only = true, |
| 603 | .ret_type = RET_INTEGER, |
| 604 | .arg1_type = ARG_CONST_MAP_PTR, |
| 605 | .arg2_type = ARG_ANYTHING, |
| 606 | .arg3_type = ARG_PTR_TO_UNINIT_MEM, |
| 607 | .arg4_type = ARG_CONST_SIZE, |
| 608 | }; |
| 609 | |
| 610 | const struct bpf_func_proto *bpf_get_perf_event_read_value_proto(void) |
| 611 | { |
| 612 | return &bpf_perf_event_read_value_proto; |
| 613 | } |
| 614 | |
| 615 | static __always_inline u64 |
| 616 | __bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map, |
| 617 | u64 flags, struct perf_raw_record *raw, |
| 618 | struct perf_sample_data *sd) |
| 619 | { |
| 620 | struct bpf_array *array = container_of(map, struct bpf_array, map); |
| 621 | unsigned int cpu = smp_processor_id(); |
| 622 | u64 index = flags & BPF_F_INDEX_MASK; |
| 623 | struct bpf_event_entry *ee; |
| 624 | struct perf_event *event; |
| 625 | |
| 626 | if (index == BPF_F_CURRENT_CPU) |
| 627 | index = cpu; |
| 628 | if (unlikely(index >= array->map.max_entries)) |
| 629 | return -E2BIG; |
| 630 | |
| 631 | ee = READ_ONCE(array->ptrs[index]); |
| 632 | if (!ee) |
| 633 | return -ENOENT; |
| 634 | |
| 635 | event = ee->event; |
| 636 | if (unlikely(event->attr.type != PERF_TYPE_SOFTWARE || |
| 637 | event->attr.config != PERF_COUNT_SW_BPF_OUTPUT)) |
| 638 | return -EINVAL; |
| 639 | |
| 640 | if (unlikely(event->oncpu != cpu)) |
| 641 | return -EOPNOTSUPP; |
| 642 | |
| 643 | perf_sample_save_raw_data(sd, event, raw); |
| 644 | |
| 645 | return perf_event_output(event, sd, regs); |
| 646 | } |
| 647 | |
| 648 | /* |
| 649 | * Support executing tracepoints in normal, irq, and nmi context that each call |
| 650 | * bpf_perf_event_output |
| 651 | */ |
| 652 | struct bpf_trace_sample_data { |
| 653 | struct perf_sample_data sds[3]; |
| 654 | }; |
| 655 | |
| 656 | static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_trace_sds); |
| 657 | static DEFINE_PER_CPU(int, bpf_trace_nest_level); |
| 658 | BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map, |
| 659 | u64, flags, void *, data, u64, size) |
| 660 | { |
| 661 | struct bpf_trace_sample_data *sds; |
| 662 | struct perf_raw_record raw = { |
| 663 | .frag = { |
| 664 | .size = size, |
| 665 | .data = data, |
| 666 | }, |
| 667 | }; |
| 668 | struct perf_sample_data *sd; |
| 669 | int nest_level, err; |
| 670 | |
| 671 | preempt_disable(); |
| 672 | sds = this_cpu_ptr(&bpf_trace_sds); |
| 673 | nest_level = this_cpu_inc_return(bpf_trace_nest_level); |
| 674 | |
| 675 | if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(sds->sds))) { |
| 676 | err = -EBUSY; |
| 677 | goto out; |
| 678 | } |
| 679 | |
| 680 | sd = &sds->sds[nest_level - 1]; |
| 681 | |
| 682 | if (unlikely(flags & ~(BPF_F_INDEX_MASK))) { |
| 683 | err = -EINVAL; |
| 684 | goto out; |
| 685 | } |
| 686 | |
| 687 | perf_sample_data_init(sd, 0, 0); |
| 688 | |
| 689 | err = __bpf_perf_event_output(regs, map, flags, &raw, sd); |
| 690 | out: |
| 691 | this_cpu_dec(bpf_trace_nest_level); |
| 692 | preempt_enable(); |
| 693 | return err; |
| 694 | } |
| 695 | |
| 696 | static const struct bpf_func_proto bpf_perf_event_output_proto = { |
| 697 | .func = bpf_perf_event_output, |
| 698 | .gpl_only = true, |
| 699 | .ret_type = RET_INTEGER, |
| 700 | .arg1_type = ARG_PTR_TO_CTX, |
| 701 | .arg2_type = ARG_CONST_MAP_PTR, |
| 702 | .arg3_type = ARG_ANYTHING, |
| 703 | .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, |
| 704 | .arg5_type = ARG_CONST_SIZE_OR_ZERO, |
| 705 | }; |
| 706 | |
| 707 | static DEFINE_PER_CPU(int, bpf_event_output_nest_level); |
| 708 | struct bpf_nested_pt_regs { |
| 709 | struct pt_regs regs[3]; |
| 710 | }; |
| 711 | static DEFINE_PER_CPU(struct bpf_nested_pt_regs, bpf_pt_regs); |
| 712 | static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_misc_sds); |
| 713 | |
| 714 | u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size, |
| 715 | void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy) |
| 716 | { |
| 717 | struct perf_raw_frag frag = { |
| 718 | .copy = ctx_copy, |
| 719 | .size = ctx_size, |
| 720 | .data = ctx, |
| 721 | }; |
| 722 | struct perf_raw_record raw = { |
| 723 | .frag = { |
| 724 | { |
| 725 | .next = ctx_size ? &frag : NULL, |
| 726 | }, |
| 727 | .size = meta_size, |
| 728 | .data = meta, |
| 729 | }, |
| 730 | }; |
| 731 | struct perf_sample_data *sd; |
| 732 | struct pt_regs *regs; |
| 733 | int nest_level; |
| 734 | u64 ret; |
| 735 | |
| 736 | preempt_disable(); |
| 737 | nest_level = this_cpu_inc_return(bpf_event_output_nest_level); |
| 738 | |
| 739 | if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(bpf_misc_sds.sds))) { |
| 740 | ret = -EBUSY; |
| 741 | goto out; |
| 742 | } |
| 743 | sd = this_cpu_ptr(&bpf_misc_sds.sds[nest_level - 1]); |
| 744 | regs = this_cpu_ptr(&bpf_pt_regs.regs[nest_level - 1]); |
| 745 | |
| 746 | perf_fetch_caller_regs(regs); |
| 747 | perf_sample_data_init(sd, 0, 0); |
| 748 | |
| 749 | ret = __bpf_perf_event_output(regs, map, flags, &raw, sd); |
| 750 | out: |
| 751 | this_cpu_dec(bpf_event_output_nest_level); |
| 752 | preempt_enable(); |
| 753 | return ret; |
| 754 | } |
| 755 | |
| 756 | BPF_CALL_0(bpf_get_current_task) |
| 757 | { |
| 758 | return (long) current; |
| 759 | } |
| 760 | |
| 761 | const struct bpf_func_proto bpf_get_current_task_proto = { |
| 762 | .func = bpf_get_current_task, |
| 763 | .gpl_only = true, |
| 764 | .ret_type = RET_INTEGER, |
| 765 | }; |
| 766 | |
| 767 | BPF_CALL_0(bpf_get_current_task_btf) |
| 768 | { |
| 769 | return (unsigned long) current; |
| 770 | } |
| 771 | |
| 772 | const struct bpf_func_proto bpf_get_current_task_btf_proto = { |
| 773 | .func = bpf_get_current_task_btf, |
| 774 | .gpl_only = true, |
| 775 | .ret_type = RET_PTR_TO_BTF_ID_TRUSTED, |
| 776 | .ret_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK], |
| 777 | }; |
| 778 | |
| 779 | BPF_CALL_1(bpf_task_pt_regs, struct task_struct *, task) |
| 780 | { |
| 781 | return (unsigned long) task_pt_regs(task); |
| 782 | } |
| 783 | |
| 784 | BTF_ID_LIST(bpf_task_pt_regs_ids) |
| 785 | BTF_ID(struct, pt_regs) |
| 786 | |
| 787 | const struct bpf_func_proto bpf_task_pt_regs_proto = { |
| 788 | .func = bpf_task_pt_regs, |
| 789 | .gpl_only = true, |
| 790 | .arg1_type = ARG_PTR_TO_BTF_ID, |
| 791 | .arg1_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK], |
| 792 | .ret_type = RET_PTR_TO_BTF_ID, |
| 793 | .ret_btf_id = &bpf_task_pt_regs_ids[0], |
| 794 | }; |
| 795 | |
| 796 | struct send_signal_irq_work { |
| 797 | struct irq_work irq_work; |
| 798 | struct task_struct *task; |
| 799 | u32 sig; |
| 800 | enum pid_type type; |
| 801 | bool has_siginfo; |
| 802 | struct kernel_siginfo info; |
| 803 | }; |
| 804 | |
| 805 | static DEFINE_PER_CPU(struct send_signal_irq_work, send_signal_work); |
| 806 | |
| 807 | static void do_bpf_send_signal(struct irq_work *entry) |
| 808 | { |
| 809 | struct send_signal_irq_work *work; |
| 810 | struct kernel_siginfo *siginfo; |
| 811 | |
| 812 | work = container_of(entry, struct send_signal_irq_work, irq_work); |
| 813 | siginfo = work->has_siginfo ? &work->info : SEND_SIG_PRIV; |
| 814 | |
| 815 | group_send_sig_info(work->sig, siginfo, work->task, work->type); |
| 816 | put_task_struct(work->task); |
| 817 | } |
| 818 | |
| 819 | static int bpf_send_signal_common(u32 sig, enum pid_type type, struct task_struct *task, u64 value) |
| 820 | { |
| 821 | struct send_signal_irq_work *work = NULL; |
| 822 | struct kernel_siginfo info; |
| 823 | struct kernel_siginfo *siginfo; |
| 824 | |
| 825 | if (!task) { |
| 826 | task = current; |
| 827 | siginfo = SEND_SIG_PRIV; |
| 828 | } else { |
| 829 | clear_siginfo(&info); |
| 830 | info.si_signo = sig; |
| 831 | info.si_errno = 0; |
| 832 | info.si_code = SI_KERNEL; |
| 833 | info.si_pid = 0; |
| 834 | info.si_uid = 0; |
| 835 | info.si_value.sival_ptr = (void *)(unsigned long)value; |
| 836 | siginfo = &info; |
| 837 | } |
| 838 | |
| 839 | /* Similar to bpf_probe_write_user, task needs to be |
| 840 | * in a sound condition and kernel memory access be |
| 841 | * permitted in order to send signal to the current |
| 842 | * task. |
| 843 | */ |
| 844 | if (unlikely(task->flags & (PF_KTHREAD | PF_EXITING))) |
| 845 | return -EPERM; |
| 846 | if (unlikely(!nmi_uaccess_okay())) |
| 847 | return -EPERM; |
| 848 | /* Task should not be pid=1 to avoid kernel panic. */ |
| 849 | if (unlikely(is_global_init(task))) |
| 850 | return -EPERM; |
| 851 | |
| 852 | if (preempt_count() != 0 || irqs_disabled()) { |
| 853 | /* Do an early check on signal validity. Otherwise, |
| 854 | * the error is lost in deferred irq_work. |
| 855 | */ |
| 856 | if (unlikely(!valid_signal(sig))) |
| 857 | return -EINVAL; |
| 858 | |
| 859 | work = this_cpu_ptr(&send_signal_work); |
| 860 | if (irq_work_is_busy(&work->irq_work)) |
| 861 | return -EBUSY; |
| 862 | |
| 863 | /* Add the current task, which is the target of sending signal, |
| 864 | * to the irq_work. The current task may change when queued |
| 865 | * irq works get executed. |
| 866 | */ |
| 867 | work->task = get_task_struct(task); |
| 868 | work->has_siginfo = siginfo == &info; |
| 869 | if (work->has_siginfo) |
| 870 | copy_siginfo(&work->info, &info); |
| 871 | work->sig = sig; |
| 872 | work->type = type; |
| 873 | irq_work_queue(&work->irq_work); |
| 874 | return 0; |
| 875 | } |
| 876 | |
| 877 | return group_send_sig_info(sig, siginfo, task, type); |
| 878 | } |
| 879 | |
| 880 | BPF_CALL_1(bpf_send_signal, u32, sig) |
| 881 | { |
| 882 | return bpf_send_signal_common(sig, PIDTYPE_TGID, NULL, 0); |
| 883 | } |
| 884 | |
| 885 | const struct bpf_func_proto bpf_send_signal_proto = { |
| 886 | .func = bpf_send_signal, |
| 887 | .gpl_only = false, |
| 888 | .ret_type = RET_INTEGER, |
| 889 | .arg1_type = ARG_ANYTHING, |
| 890 | }; |
| 891 | |
| 892 | BPF_CALL_1(bpf_send_signal_thread, u32, sig) |
| 893 | { |
| 894 | return bpf_send_signal_common(sig, PIDTYPE_PID, NULL, 0); |
| 895 | } |
| 896 | |
| 897 | const struct bpf_func_proto bpf_send_signal_thread_proto = { |
| 898 | .func = bpf_send_signal_thread, |
| 899 | .gpl_only = false, |
| 900 | .ret_type = RET_INTEGER, |
| 901 | .arg1_type = ARG_ANYTHING, |
| 902 | }; |
| 903 | |
| 904 | BPF_CALL_3(bpf_d_path, struct path *, path, char *, buf, u32, sz) |
| 905 | { |
| 906 | struct path copy; |
| 907 | long len; |
| 908 | char *p; |
| 909 | |
| 910 | if (!sz) |
| 911 | return 0; |
| 912 | |
| 913 | /* |
| 914 | * The path pointer is verified as trusted and safe to use, |
| 915 | * but let's double check it's valid anyway to workaround |
| 916 | * potentially broken verifier. |
| 917 | */ |
| 918 | len = copy_from_kernel_nofault(©, path, sizeof(*path)); |
| 919 | if (len < 0) |
| 920 | return len; |
| 921 | |
| 922 | p = d_path(©, buf, sz); |
| 923 | if (IS_ERR(p)) { |
| 924 | len = PTR_ERR(p); |
| 925 | } else { |
| 926 | len = buf + sz - p; |
| 927 | memmove(buf, p, len); |
| 928 | } |
| 929 | |
| 930 | return len; |
| 931 | } |
| 932 | |
| 933 | BTF_SET_START(btf_allowlist_d_path) |
| 934 | #ifdef CONFIG_SECURITY |
| 935 | BTF_ID(func, security_file_permission) |
| 936 | BTF_ID(func, security_inode_getattr) |
| 937 | BTF_ID(func, security_file_open) |
| 938 | #endif |
| 939 | #ifdef CONFIG_SECURITY_PATH |
| 940 | BTF_ID(func, security_path_truncate) |
| 941 | #endif |
| 942 | BTF_ID(func, vfs_truncate) |
| 943 | BTF_ID(func, vfs_fallocate) |
| 944 | BTF_ID(func, dentry_open) |
| 945 | BTF_ID(func, vfs_getattr) |
| 946 | BTF_ID(func, filp_close) |
| 947 | BTF_SET_END(btf_allowlist_d_path) |
| 948 | |
| 949 | static bool bpf_d_path_allowed(const struct bpf_prog *prog) |
| 950 | { |
| 951 | if (prog->type == BPF_PROG_TYPE_TRACING && |
| 952 | prog->expected_attach_type == BPF_TRACE_ITER) |
| 953 | return true; |
| 954 | |
| 955 | if (prog->type == BPF_PROG_TYPE_LSM) |
| 956 | return bpf_lsm_is_sleepable_hook(prog->aux->attach_btf_id); |
| 957 | |
| 958 | return btf_id_set_contains(&btf_allowlist_d_path, |
| 959 | prog->aux->attach_btf_id); |
| 960 | } |
| 961 | |
| 962 | BTF_ID_LIST_SINGLE(bpf_d_path_btf_ids, struct, path) |
| 963 | |
| 964 | static const struct bpf_func_proto bpf_d_path_proto = { |
| 965 | .func = bpf_d_path, |
| 966 | .gpl_only = false, |
| 967 | .ret_type = RET_INTEGER, |
| 968 | .arg1_type = ARG_PTR_TO_BTF_ID, |
| 969 | .arg1_btf_id = &bpf_d_path_btf_ids[0], |
| 970 | .arg2_type = ARG_PTR_TO_MEM, |
| 971 | .arg3_type = ARG_CONST_SIZE_OR_ZERO, |
| 972 | .allowed = bpf_d_path_allowed, |
| 973 | }; |
| 974 | |
| 975 | #define BTF_F_ALL (BTF_F_COMPACT | BTF_F_NONAME | \ |
| 976 | BTF_F_PTR_RAW | BTF_F_ZERO) |
| 977 | |
| 978 | static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size, |
| 979 | u64 flags, const struct btf **btf, |
| 980 | s32 *btf_id) |
| 981 | { |
| 982 | const struct btf_type *t; |
| 983 | |
| 984 | if (unlikely(flags & ~(BTF_F_ALL))) |
| 985 | return -EINVAL; |
| 986 | |
| 987 | if (btf_ptr_size != sizeof(struct btf_ptr)) |
| 988 | return -EINVAL; |
| 989 | |
| 990 | *btf = bpf_get_btf_vmlinux(); |
| 991 | |
| 992 | if (IS_ERR_OR_NULL(*btf)) |
| 993 | return IS_ERR(*btf) ? PTR_ERR(*btf) : -EINVAL; |
| 994 | |
| 995 | if (ptr->type_id > 0) |
| 996 | *btf_id = ptr->type_id; |
| 997 | else |
| 998 | return -EINVAL; |
| 999 | |
| 1000 | if (*btf_id > 0) |
| 1001 | t = btf_type_by_id(*btf, *btf_id); |
| 1002 | if (*btf_id <= 0 || !t) |
| 1003 | return -ENOENT; |
| 1004 | |
| 1005 | return 0; |
| 1006 | } |
| 1007 | |
| 1008 | BPF_CALL_5(bpf_snprintf_btf, char *, str, u32, str_size, struct btf_ptr *, ptr, |
| 1009 | u32, btf_ptr_size, u64, flags) |
| 1010 | { |
| 1011 | const struct btf *btf; |
| 1012 | s32 btf_id; |
| 1013 | int ret; |
| 1014 | |
| 1015 | ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id); |
| 1016 | if (ret) |
| 1017 | return ret; |
| 1018 | |
| 1019 | return btf_type_snprintf_show(btf, btf_id, ptr->ptr, str, str_size, |
| 1020 | flags); |
| 1021 | } |
| 1022 | |
| 1023 | const struct bpf_func_proto bpf_snprintf_btf_proto = { |
| 1024 | .func = bpf_snprintf_btf, |
| 1025 | .gpl_only = false, |
| 1026 | .ret_type = RET_INTEGER, |
| 1027 | .arg1_type = ARG_PTR_TO_MEM, |
| 1028 | .arg2_type = ARG_CONST_SIZE, |
| 1029 | .arg3_type = ARG_PTR_TO_MEM | MEM_RDONLY, |
| 1030 | .arg4_type = ARG_CONST_SIZE, |
| 1031 | .arg5_type = ARG_ANYTHING, |
| 1032 | }; |
| 1033 | |
| 1034 | BPF_CALL_1(bpf_get_func_ip_tracing, void *, ctx) |
| 1035 | { |
| 1036 | /* This helper call is inlined by verifier. */ |
| 1037 | return ((u64 *)ctx)[-2]; |
| 1038 | } |
| 1039 | |
| 1040 | static const struct bpf_func_proto bpf_get_func_ip_proto_tracing = { |
| 1041 | .func = bpf_get_func_ip_tracing, |
| 1042 | .gpl_only = true, |
| 1043 | .ret_type = RET_INTEGER, |
| 1044 | .arg1_type = ARG_PTR_TO_CTX, |
| 1045 | }; |
| 1046 | |
| 1047 | static inline unsigned long get_entry_ip(unsigned long fentry_ip) |
| 1048 | { |
| 1049 | #ifdef CONFIG_X86_KERNEL_IBT |
| 1050 | if (is_endbr((void *)(fentry_ip - ENDBR_INSN_SIZE))) |
| 1051 | fentry_ip -= ENDBR_INSN_SIZE; |
| 1052 | #endif |
| 1053 | return fentry_ip; |
| 1054 | } |
| 1055 | |
| 1056 | BPF_CALL_1(bpf_get_func_ip_kprobe, struct pt_regs *, regs) |
| 1057 | { |
| 1058 | struct bpf_trace_run_ctx *run_ctx __maybe_unused; |
| 1059 | struct kprobe *kp; |
| 1060 | |
| 1061 | #ifdef CONFIG_UPROBES |
| 1062 | run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); |
| 1063 | if (run_ctx->is_uprobe) |
| 1064 | return ((struct uprobe_dispatch_data *)current->utask->vaddr)->bp_addr; |
| 1065 | #endif |
| 1066 | |
| 1067 | kp = kprobe_running(); |
| 1068 | |
| 1069 | if (!kp || !(kp->flags & KPROBE_FLAG_ON_FUNC_ENTRY)) |
| 1070 | return 0; |
| 1071 | |
| 1072 | return get_entry_ip((uintptr_t)kp->addr); |
| 1073 | } |
| 1074 | |
| 1075 | static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe = { |
| 1076 | .func = bpf_get_func_ip_kprobe, |
| 1077 | .gpl_only = true, |
| 1078 | .ret_type = RET_INTEGER, |
| 1079 | .arg1_type = ARG_PTR_TO_CTX, |
| 1080 | }; |
| 1081 | |
| 1082 | BPF_CALL_1(bpf_get_func_ip_kprobe_multi, struct pt_regs *, regs) |
| 1083 | { |
| 1084 | return bpf_kprobe_multi_entry_ip(current->bpf_ctx); |
| 1085 | } |
| 1086 | |
| 1087 | static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe_multi = { |
| 1088 | .func = bpf_get_func_ip_kprobe_multi, |
| 1089 | .gpl_only = false, |
| 1090 | .ret_type = RET_INTEGER, |
| 1091 | .arg1_type = ARG_PTR_TO_CTX, |
| 1092 | }; |
| 1093 | |
| 1094 | BPF_CALL_1(bpf_get_attach_cookie_kprobe_multi, struct pt_regs *, regs) |
| 1095 | { |
| 1096 | return bpf_kprobe_multi_cookie(current->bpf_ctx); |
| 1097 | } |
| 1098 | |
| 1099 | static const struct bpf_func_proto bpf_get_attach_cookie_proto_kmulti = { |
| 1100 | .func = bpf_get_attach_cookie_kprobe_multi, |
| 1101 | .gpl_only = false, |
| 1102 | .ret_type = RET_INTEGER, |
| 1103 | .arg1_type = ARG_PTR_TO_CTX, |
| 1104 | }; |
| 1105 | |
| 1106 | BPF_CALL_1(bpf_get_func_ip_uprobe_multi, struct pt_regs *, regs) |
| 1107 | { |
| 1108 | return bpf_uprobe_multi_entry_ip(current->bpf_ctx); |
| 1109 | } |
| 1110 | |
| 1111 | static const struct bpf_func_proto bpf_get_func_ip_proto_uprobe_multi = { |
| 1112 | .func = bpf_get_func_ip_uprobe_multi, |
| 1113 | .gpl_only = false, |
| 1114 | .ret_type = RET_INTEGER, |
| 1115 | .arg1_type = ARG_PTR_TO_CTX, |
| 1116 | }; |
| 1117 | |
| 1118 | BPF_CALL_1(bpf_get_attach_cookie_uprobe_multi, struct pt_regs *, regs) |
| 1119 | { |
| 1120 | return bpf_uprobe_multi_cookie(current->bpf_ctx); |
| 1121 | } |
| 1122 | |
| 1123 | static const struct bpf_func_proto bpf_get_attach_cookie_proto_umulti = { |
| 1124 | .func = bpf_get_attach_cookie_uprobe_multi, |
| 1125 | .gpl_only = false, |
| 1126 | .ret_type = RET_INTEGER, |
| 1127 | .arg1_type = ARG_PTR_TO_CTX, |
| 1128 | }; |
| 1129 | |
| 1130 | BPF_CALL_1(bpf_get_attach_cookie_trace, void *, ctx) |
| 1131 | { |
| 1132 | struct bpf_trace_run_ctx *run_ctx; |
| 1133 | |
| 1134 | run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); |
| 1135 | return run_ctx->bpf_cookie; |
| 1136 | } |
| 1137 | |
| 1138 | static const struct bpf_func_proto bpf_get_attach_cookie_proto_trace = { |
| 1139 | .func = bpf_get_attach_cookie_trace, |
| 1140 | .gpl_only = false, |
| 1141 | .ret_type = RET_INTEGER, |
| 1142 | .arg1_type = ARG_PTR_TO_CTX, |
| 1143 | }; |
| 1144 | |
| 1145 | BPF_CALL_1(bpf_get_attach_cookie_pe, struct bpf_perf_event_data_kern *, ctx) |
| 1146 | { |
| 1147 | return ctx->event->bpf_cookie; |
| 1148 | } |
| 1149 | |
| 1150 | static const struct bpf_func_proto bpf_get_attach_cookie_proto_pe = { |
| 1151 | .func = bpf_get_attach_cookie_pe, |
| 1152 | .gpl_only = false, |
| 1153 | .ret_type = RET_INTEGER, |
| 1154 | .arg1_type = ARG_PTR_TO_CTX, |
| 1155 | }; |
| 1156 | |
| 1157 | BPF_CALL_1(bpf_get_attach_cookie_tracing, void *, ctx) |
| 1158 | { |
| 1159 | struct bpf_trace_run_ctx *run_ctx; |
| 1160 | |
| 1161 | run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); |
| 1162 | return run_ctx->bpf_cookie; |
| 1163 | } |
| 1164 | |
| 1165 | static const struct bpf_func_proto bpf_get_attach_cookie_proto_tracing = { |
| 1166 | .func = bpf_get_attach_cookie_tracing, |
| 1167 | .gpl_only = false, |
| 1168 | .ret_type = RET_INTEGER, |
| 1169 | .arg1_type = ARG_PTR_TO_CTX, |
| 1170 | }; |
| 1171 | |
| 1172 | BPF_CALL_3(bpf_get_branch_snapshot, void *, buf, u32, size, u64, flags) |
| 1173 | { |
| 1174 | static const u32 br_entry_size = sizeof(struct perf_branch_entry); |
| 1175 | u32 entry_cnt = size / br_entry_size; |
| 1176 | |
| 1177 | entry_cnt = static_call(perf_snapshot_branch_stack)(buf, entry_cnt); |
| 1178 | |
| 1179 | if (unlikely(flags)) |
| 1180 | return -EINVAL; |
| 1181 | |
| 1182 | if (!entry_cnt) |
| 1183 | return -ENOENT; |
| 1184 | |
| 1185 | return entry_cnt * br_entry_size; |
| 1186 | } |
| 1187 | |
| 1188 | const struct bpf_func_proto bpf_get_branch_snapshot_proto = { |
| 1189 | .func = bpf_get_branch_snapshot, |
| 1190 | .gpl_only = true, |
| 1191 | .ret_type = RET_INTEGER, |
| 1192 | .arg1_type = ARG_PTR_TO_UNINIT_MEM, |
| 1193 | .arg2_type = ARG_CONST_SIZE_OR_ZERO, |
| 1194 | }; |
| 1195 | |
| 1196 | BPF_CALL_3(get_func_arg, void *, ctx, u32, n, u64 *, value) |
| 1197 | { |
| 1198 | /* This helper call is inlined by verifier. */ |
| 1199 | u64 nr_args = ((u64 *)ctx)[-1]; |
| 1200 | |
| 1201 | if ((u64) n >= nr_args) |
| 1202 | return -EINVAL; |
| 1203 | *value = ((u64 *)ctx)[n]; |
| 1204 | return 0; |
| 1205 | } |
| 1206 | |
| 1207 | static const struct bpf_func_proto bpf_get_func_arg_proto = { |
| 1208 | .func = get_func_arg, |
| 1209 | .ret_type = RET_INTEGER, |
| 1210 | .arg1_type = ARG_PTR_TO_CTX, |
| 1211 | .arg2_type = ARG_ANYTHING, |
| 1212 | .arg3_type = ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED, |
| 1213 | .arg3_size = sizeof(u64), |
| 1214 | }; |
| 1215 | |
| 1216 | BPF_CALL_2(get_func_ret, void *, ctx, u64 *, value) |
| 1217 | { |
| 1218 | /* This helper call is inlined by verifier. */ |
| 1219 | u64 nr_args = ((u64 *)ctx)[-1]; |
| 1220 | |
| 1221 | *value = ((u64 *)ctx)[nr_args]; |
| 1222 | return 0; |
| 1223 | } |
| 1224 | |
| 1225 | static const struct bpf_func_proto bpf_get_func_ret_proto = { |
| 1226 | .func = get_func_ret, |
| 1227 | .ret_type = RET_INTEGER, |
| 1228 | .arg1_type = ARG_PTR_TO_CTX, |
| 1229 | .arg2_type = ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED, |
| 1230 | .arg2_size = sizeof(u64), |
| 1231 | }; |
| 1232 | |
| 1233 | BPF_CALL_1(get_func_arg_cnt, void *, ctx) |
| 1234 | { |
| 1235 | /* This helper call is inlined by verifier. */ |
| 1236 | return ((u64 *)ctx)[-1]; |
| 1237 | } |
| 1238 | |
| 1239 | static const struct bpf_func_proto bpf_get_func_arg_cnt_proto = { |
| 1240 | .func = get_func_arg_cnt, |
| 1241 | .ret_type = RET_INTEGER, |
| 1242 | .arg1_type = ARG_PTR_TO_CTX, |
| 1243 | }; |
| 1244 | |
| 1245 | #ifdef CONFIG_KEYS |
| 1246 | __bpf_kfunc_start_defs(); |
| 1247 | |
| 1248 | /** |
| 1249 | * bpf_lookup_user_key - lookup a key by its serial |
| 1250 | * @serial: key handle serial number |
| 1251 | * @flags: lookup-specific flags |
| 1252 | * |
| 1253 | * Search a key with a given *serial* and the provided *flags*. |
| 1254 | * If found, increment the reference count of the key by one, and |
| 1255 | * return it in the bpf_key structure. |
| 1256 | * |
| 1257 | * The bpf_key structure must be passed to bpf_key_put() when done |
| 1258 | * with it, so that the key reference count is decremented and the |
| 1259 | * bpf_key structure is freed. |
| 1260 | * |
| 1261 | * Permission checks are deferred to the time the key is used by |
| 1262 | * one of the available key-specific kfuncs. |
| 1263 | * |
| 1264 | * Set *flags* with KEY_LOOKUP_CREATE, to attempt creating a requested |
| 1265 | * special keyring (e.g. session keyring), if it doesn't yet exist. |
| 1266 | * Set *flags* with KEY_LOOKUP_PARTIAL, to lookup a key without waiting |
| 1267 | * for the key construction, and to retrieve uninstantiated keys (keys |
| 1268 | * without data attached to them). |
| 1269 | * |
| 1270 | * Return: a bpf_key pointer with a valid key pointer if the key is found, a |
| 1271 | * NULL pointer otherwise. |
| 1272 | */ |
| 1273 | __bpf_kfunc struct bpf_key *bpf_lookup_user_key(u32 serial, u64 flags) |
| 1274 | { |
| 1275 | key_ref_t key_ref; |
| 1276 | struct bpf_key *bkey; |
| 1277 | |
| 1278 | if (flags & ~KEY_LOOKUP_ALL) |
| 1279 | return NULL; |
| 1280 | |
| 1281 | /* |
| 1282 | * Permission check is deferred until the key is used, as the |
| 1283 | * intent of the caller is unknown here. |
| 1284 | */ |
| 1285 | key_ref = lookup_user_key(serial, flags, KEY_DEFER_PERM_CHECK); |
| 1286 | if (IS_ERR(key_ref)) |
| 1287 | return NULL; |
| 1288 | |
| 1289 | bkey = kmalloc(sizeof(*bkey), GFP_KERNEL); |
| 1290 | if (!bkey) { |
| 1291 | key_put(key_ref_to_ptr(key_ref)); |
| 1292 | return NULL; |
| 1293 | } |
| 1294 | |
| 1295 | bkey->key = key_ref_to_ptr(key_ref); |
| 1296 | bkey->has_ref = true; |
| 1297 | |
| 1298 | return bkey; |
| 1299 | } |
| 1300 | |
| 1301 | /** |
| 1302 | * bpf_lookup_system_key - lookup a key by a system-defined ID |
| 1303 | * @id: key ID |
| 1304 | * |
| 1305 | * Obtain a bpf_key structure with a key pointer set to the passed key ID. |
| 1306 | * The key pointer is marked as invalid, to prevent bpf_key_put() from |
| 1307 | * attempting to decrement the key reference count on that pointer. The key |
| 1308 | * pointer set in such way is currently understood only by |
| 1309 | * verify_pkcs7_signature(). |
| 1310 | * |
| 1311 | * Set *id* to one of the values defined in include/linux/verification.h: |
| 1312 | * 0 for the primary keyring (immutable keyring of system keys); |
| 1313 | * VERIFY_USE_SECONDARY_KEYRING for both the primary and secondary keyring |
| 1314 | * (where keys can be added only if they are vouched for by existing keys |
| 1315 | * in those keyrings); VERIFY_USE_PLATFORM_KEYRING for the platform |
| 1316 | * keyring (primarily used by the integrity subsystem to verify a kexec'ed |
| 1317 | * kerned image and, possibly, the initramfs signature). |
| 1318 | * |
| 1319 | * Return: a bpf_key pointer with an invalid key pointer set from the |
| 1320 | * pre-determined ID on success, a NULL pointer otherwise |
| 1321 | */ |
| 1322 | __bpf_kfunc struct bpf_key *bpf_lookup_system_key(u64 id) |
| 1323 | { |
| 1324 | struct bpf_key *bkey; |
| 1325 | |
| 1326 | if (system_keyring_id_check(id) < 0) |
| 1327 | return NULL; |
| 1328 | |
| 1329 | bkey = kmalloc(sizeof(*bkey), GFP_ATOMIC); |
| 1330 | if (!bkey) |
| 1331 | return NULL; |
| 1332 | |
| 1333 | bkey->key = (struct key *)(unsigned long)id; |
| 1334 | bkey->has_ref = false; |
| 1335 | |
| 1336 | return bkey; |
| 1337 | } |
| 1338 | |
| 1339 | /** |
| 1340 | * bpf_key_put - decrement key reference count if key is valid and free bpf_key |
| 1341 | * @bkey: bpf_key structure |
| 1342 | * |
| 1343 | * Decrement the reference count of the key inside *bkey*, if the pointer |
| 1344 | * is valid, and free *bkey*. |
| 1345 | */ |
| 1346 | __bpf_kfunc void bpf_key_put(struct bpf_key *bkey) |
| 1347 | { |
| 1348 | if (bkey->has_ref) |
| 1349 | key_put(bkey->key); |
| 1350 | |
| 1351 | kfree(bkey); |
| 1352 | } |
| 1353 | |
| 1354 | #ifdef CONFIG_SYSTEM_DATA_VERIFICATION |
| 1355 | /** |
| 1356 | * bpf_verify_pkcs7_signature - verify a PKCS#7 signature |
| 1357 | * @data_p: data to verify |
| 1358 | * @sig_p: signature of the data |
| 1359 | * @trusted_keyring: keyring with keys trusted for signature verification |
| 1360 | * |
| 1361 | * Verify the PKCS#7 signature *sig_ptr* against the supplied *data_ptr* |
| 1362 | * with keys in a keyring referenced by *trusted_keyring*. |
| 1363 | * |
| 1364 | * Return: 0 on success, a negative value on error. |
| 1365 | */ |
| 1366 | __bpf_kfunc int bpf_verify_pkcs7_signature(struct bpf_dynptr *data_p, |
| 1367 | struct bpf_dynptr *sig_p, |
| 1368 | struct bpf_key *trusted_keyring) |
| 1369 | { |
| 1370 | struct bpf_dynptr_kern *data_ptr = (struct bpf_dynptr_kern *)data_p; |
| 1371 | struct bpf_dynptr_kern *sig_ptr = (struct bpf_dynptr_kern *)sig_p; |
| 1372 | const void *data, *sig; |
| 1373 | u32 data_len, sig_len; |
| 1374 | int ret; |
| 1375 | |
| 1376 | if (trusted_keyring->has_ref) { |
| 1377 | /* |
| 1378 | * Do the permission check deferred in bpf_lookup_user_key(). |
| 1379 | * See bpf_lookup_user_key() for more details. |
| 1380 | * |
| 1381 | * A call to key_task_permission() here would be redundant, as |
| 1382 | * it is already done by keyring_search() called by |
| 1383 | * find_asymmetric_key(). |
| 1384 | */ |
| 1385 | ret = key_validate(trusted_keyring->key); |
| 1386 | if (ret < 0) |
| 1387 | return ret; |
| 1388 | } |
| 1389 | |
| 1390 | data_len = __bpf_dynptr_size(data_ptr); |
| 1391 | data = __bpf_dynptr_data(data_ptr, data_len); |
| 1392 | sig_len = __bpf_dynptr_size(sig_ptr); |
| 1393 | sig = __bpf_dynptr_data(sig_ptr, sig_len); |
| 1394 | |
| 1395 | return verify_pkcs7_signature(data, data_len, sig, sig_len, |
| 1396 | trusted_keyring->key, |
| 1397 | VERIFYING_UNSPECIFIED_SIGNATURE, NULL, |
| 1398 | NULL); |
| 1399 | } |
| 1400 | #endif /* CONFIG_SYSTEM_DATA_VERIFICATION */ |
| 1401 | |
| 1402 | __bpf_kfunc_end_defs(); |
| 1403 | |
| 1404 | BTF_KFUNCS_START(key_sig_kfunc_set) |
| 1405 | BTF_ID_FLAGS(func, bpf_lookup_user_key, KF_ACQUIRE | KF_RET_NULL | KF_SLEEPABLE) |
| 1406 | BTF_ID_FLAGS(func, bpf_lookup_system_key, KF_ACQUIRE | KF_RET_NULL) |
| 1407 | BTF_ID_FLAGS(func, bpf_key_put, KF_RELEASE) |
| 1408 | #ifdef CONFIG_SYSTEM_DATA_VERIFICATION |
| 1409 | BTF_ID_FLAGS(func, bpf_verify_pkcs7_signature, KF_SLEEPABLE) |
| 1410 | #endif |
| 1411 | BTF_KFUNCS_END(key_sig_kfunc_set) |
| 1412 | |
| 1413 | static const struct btf_kfunc_id_set bpf_key_sig_kfunc_set = { |
| 1414 | .owner = THIS_MODULE, |
| 1415 | .set = &key_sig_kfunc_set, |
| 1416 | }; |
| 1417 | |
| 1418 | static int __init bpf_key_sig_kfuncs_init(void) |
| 1419 | { |
| 1420 | return register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, |
| 1421 | &bpf_key_sig_kfunc_set); |
| 1422 | } |
| 1423 | |
| 1424 | late_initcall(bpf_key_sig_kfuncs_init); |
| 1425 | #endif /* CONFIG_KEYS */ |
| 1426 | |
| 1427 | static const struct bpf_func_proto * |
| 1428 | bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) |
| 1429 | { |
| 1430 | const struct bpf_func_proto *func_proto; |
| 1431 | |
| 1432 | switch (func_id) { |
| 1433 | case BPF_FUNC_get_smp_processor_id: |
| 1434 | return &bpf_get_smp_processor_id_proto; |
| 1435 | #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE |
| 1436 | case BPF_FUNC_probe_read: |
| 1437 | return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? |
| 1438 | NULL : &bpf_probe_read_compat_proto; |
| 1439 | case BPF_FUNC_probe_read_str: |
| 1440 | return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? |
| 1441 | NULL : &bpf_probe_read_compat_str_proto; |
| 1442 | #endif |
| 1443 | case BPF_FUNC_get_func_ip: |
| 1444 | return &bpf_get_func_ip_proto_tracing; |
| 1445 | default: |
| 1446 | break; |
| 1447 | } |
| 1448 | |
| 1449 | func_proto = bpf_base_func_proto(func_id, prog); |
| 1450 | if (func_proto) |
| 1451 | return func_proto; |
| 1452 | |
| 1453 | if (!bpf_token_capable(prog->aux->token, CAP_SYS_ADMIN)) |
| 1454 | return NULL; |
| 1455 | |
| 1456 | switch (func_id) { |
| 1457 | case BPF_FUNC_probe_write_user: |
| 1458 | return security_locked_down(LOCKDOWN_BPF_WRITE_USER) < 0 ? |
| 1459 | NULL : &bpf_probe_write_user_proto; |
| 1460 | default: |
| 1461 | return NULL; |
| 1462 | } |
| 1463 | } |
| 1464 | |
| 1465 | static bool is_kprobe_multi(const struct bpf_prog *prog) |
| 1466 | { |
| 1467 | return prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI || |
| 1468 | prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION; |
| 1469 | } |
| 1470 | |
| 1471 | static inline bool is_kprobe_session(const struct bpf_prog *prog) |
| 1472 | { |
| 1473 | return prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION; |
| 1474 | } |
| 1475 | |
| 1476 | static inline bool is_uprobe_multi(const struct bpf_prog *prog) |
| 1477 | { |
| 1478 | return prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI || |
| 1479 | prog->expected_attach_type == BPF_TRACE_UPROBE_SESSION; |
| 1480 | } |
| 1481 | |
| 1482 | static inline bool is_uprobe_session(const struct bpf_prog *prog) |
| 1483 | { |
| 1484 | return prog->expected_attach_type == BPF_TRACE_UPROBE_SESSION; |
| 1485 | } |
| 1486 | |
| 1487 | static const struct bpf_func_proto * |
| 1488 | kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) |
| 1489 | { |
| 1490 | switch (func_id) { |
| 1491 | case BPF_FUNC_perf_event_output: |
| 1492 | return &bpf_perf_event_output_proto; |
| 1493 | case BPF_FUNC_get_stackid: |
| 1494 | return &bpf_get_stackid_proto; |
| 1495 | case BPF_FUNC_get_stack: |
| 1496 | return prog->sleepable ? &bpf_get_stack_sleepable_proto : &bpf_get_stack_proto; |
| 1497 | #ifdef CONFIG_BPF_KPROBE_OVERRIDE |
| 1498 | case BPF_FUNC_override_return: |
| 1499 | return &bpf_override_return_proto; |
| 1500 | #endif |
| 1501 | case BPF_FUNC_get_func_ip: |
| 1502 | if (is_kprobe_multi(prog)) |
| 1503 | return &bpf_get_func_ip_proto_kprobe_multi; |
| 1504 | if (is_uprobe_multi(prog)) |
| 1505 | return &bpf_get_func_ip_proto_uprobe_multi; |
| 1506 | return &bpf_get_func_ip_proto_kprobe; |
| 1507 | case BPF_FUNC_get_attach_cookie: |
| 1508 | if (is_kprobe_multi(prog)) |
| 1509 | return &bpf_get_attach_cookie_proto_kmulti; |
| 1510 | if (is_uprobe_multi(prog)) |
| 1511 | return &bpf_get_attach_cookie_proto_umulti; |
| 1512 | return &bpf_get_attach_cookie_proto_trace; |
| 1513 | default: |
| 1514 | return bpf_tracing_func_proto(func_id, prog); |
| 1515 | } |
| 1516 | } |
| 1517 | |
| 1518 | /* bpf+kprobe programs can access fields of 'struct pt_regs' */ |
| 1519 | static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type, |
| 1520 | const struct bpf_prog *prog, |
| 1521 | struct bpf_insn_access_aux *info) |
| 1522 | { |
| 1523 | if (off < 0 || off >= sizeof(struct pt_regs)) |
| 1524 | return false; |
| 1525 | if (type != BPF_READ) |
| 1526 | return false; |
| 1527 | if (off % size != 0) |
| 1528 | return false; |
| 1529 | /* |
| 1530 | * Assertion for 32 bit to make sure last 8 byte access |
| 1531 | * (BPF_DW) to the last 4 byte member is disallowed. |
| 1532 | */ |
| 1533 | if (off + size > sizeof(struct pt_regs)) |
| 1534 | return false; |
| 1535 | |
| 1536 | return true; |
| 1537 | } |
| 1538 | |
| 1539 | const struct bpf_verifier_ops kprobe_verifier_ops = { |
| 1540 | .get_func_proto = kprobe_prog_func_proto, |
| 1541 | .is_valid_access = kprobe_prog_is_valid_access, |
| 1542 | }; |
| 1543 | |
| 1544 | const struct bpf_prog_ops kprobe_prog_ops = { |
| 1545 | }; |
| 1546 | |
| 1547 | BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map, |
| 1548 | u64, flags, void *, data, u64, size) |
| 1549 | { |
| 1550 | struct pt_regs *regs = *(struct pt_regs **)tp_buff; |
| 1551 | |
| 1552 | /* |
| 1553 | * r1 points to perf tracepoint buffer where first 8 bytes are hidden |
| 1554 | * from bpf program and contain a pointer to 'struct pt_regs'. Fetch it |
| 1555 | * from there and call the same bpf_perf_event_output() helper inline. |
| 1556 | */ |
| 1557 | return ____bpf_perf_event_output(regs, map, flags, data, size); |
| 1558 | } |
| 1559 | |
| 1560 | static const struct bpf_func_proto bpf_perf_event_output_proto_tp = { |
| 1561 | .func = bpf_perf_event_output_tp, |
| 1562 | .gpl_only = true, |
| 1563 | .ret_type = RET_INTEGER, |
| 1564 | .arg1_type = ARG_PTR_TO_CTX, |
| 1565 | .arg2_type = ARG_CONST_MAP_PTR, |
| 1566 | .arg3_type = ARG_ANYTHING, |
| 1567 | .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, |
| 1568 | .arg5_type = ARG_CONST_SIZE_OR_ZERO, |
| 1569 | }; |
| 1570 | |
| 1571 | BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map, |
| 1572 | u64, flags) |
| 1573 | { |
| 1574 | struct pt_regs *regs = *(struct pt_regs **)tp_buff; |
| 1575 | |
| 1576 | /* |
| 1577 | * Same comment as in bpf_perf_event_output_tp(), only that this time |
| 1578 | * the other helper's function body cannot be inlined due to being |
| 1579 | * external, thus we need to call raw helper function. |
| 1580 | */ |
| 1581 | return bpf_get_stackid((unsigned long) regs, (unsigned long) map, |
| 1582 | flags, 0, 0); |
| 1583 | } |
| 1584 | |
| 1585 | static const struct bpf_func_proto bpf_get_stackid_proto_tp = { |
| 1586 | .func = bpf_get_stackid_tp, |
| 1587 | .gpl_only = true, |
| 1588 | .ret_type = RET_INTEGER, |
| 1589 | .arg1_type = ARG_PTR_TO_CTX, |
| 1590 | .arg2_type = ARG_CONST_MAP_PTR, |
| 1591 | .arg3_type = ARG_ANYTHING, |
| 1592 | }; |
| 1593 | |
| 1594 | BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size, |
| 1595 | u64, flags) |
| 1596 | { |
| 1597 | struct pt_regs *regs = *(struct pt_regs **)tp_buff; |
| 1598 | |
| 1599 | return bpf_get_stack((unsigned long) regs, (unsigned long) buf, |
| 1600 | (unsigned long) size, flags, 0); |
| 1601 | } |
| 1602 | |
| 1603 | static const struct bpf_func_proto bpf_get_stack_proto_tp = { |
| 1604 | .func = bpf_get_stack_tp, |
| 1605 | .gpl_only = true, |
| 1606 | .ret_type = RET_INTEGER, |
| 1607 | .arg1_type = ARG_PTR_TO_CTX, |
| 1608 | .arg2_type = ARG_PTR_TO_UNINIT_MEM, |
| 1609 | .arg3_type = ARG_CONST_SIZE_OR_ZERO, |
| 1610 | .arg4_type = ARG_ANYTHING, |
| 1611 | }; |
| 1612 | |
| 1613 | static const struct bpf_func_proto * |
| 1614 | tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) |
| 1615 | { |
| 1616 | switch (func_id) { |
| 1617 | case BPF_FUNC_perf_event_output: |
| 1618 | return &bpf_perf_event_output_proto_tp; |
| 1619 | case BPF_FUNC_get_stackid: |
| 1620 | return &bpf_get_stackid_proto_tp; |
| 1621 | case BPF_FUNC_get_stack: |
| 1622 | return &bpf_get_stack_proto_tp; |
| 1623 | case BPF_FUNC_get_attach_cookie: |
| 1624 | return &bpf_get_attach_cookie_proto_trace; |
| 1625 | default: |
| 1626 | return bpf_tracing_func_proto(func_id, prog); |
| 1627 | } |
| 1628 | } |
| 1629 | |
| 1630 | static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type, |
| 1631 | const struct bpf_prog *prog, |
| 1632 | struct bpf_insn_access_aux *info) |
| 1633 | { |
| 1634 | if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE) |
| 1635 | return false; |
| 1636 | if (type != BPF_READ) |
| 1637 | return false; |
| 1638 | if (off % size != 0) |
| 1639 | return false; |
| 1640 | |
| 1641 | BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(__u64)); |
| 1642 | return true; |
| 1643 | } |
| 1644 | |
| 1645 | const struct bpf_verifier_ops tracepoint_verifier_ops = { |
| 1646 | .get_func_proto = tp_prog_func_proto, |
| 1647 | .is_valid_access = tp_prog_is_valid_access, |
| 1648 | }; |
| 1649 | |
| 1650 | const struct bpf_prog_ops tracepoint_prog_ops = { |
| 1651 | }; |
| 1652 | |
| 1653 | BPF_CALL_3(bpf_perf_prog_read_value, struct bpf_perf_event_data_kern *, ctx, |
| 1654 | struct bpf_perf_event_value *, buf, u32, size) |
| 1655 | { |
| 1656 | int err = -EINVAL; |
| 1657 | |
| 1658 | if (unlikely(size != sizeof(struct bpf_perf_event_value))) |
| 1659 | goto clear; |
| 1660 | err = perf_event_read_local(ctx->event, &buf->counter, &buf->enabled, |
| 1661 | &buf->running); |
| 1662 | if (unlikely(err)) |
| 1663 | goto clear; |
| 1664 | return 0; |
| 1665 | clear: |
| 1666 | memset(buf, 0, size); |
| 1667 | return err; |
| 1668 | } |
| 1669 | |
| 1670 | static const struct bpf_func_proto bpf_perf_prog_read_value_proto = { |
| 1671 | .func = bpf_perf_prog_read_value, |
| 1672 | .gpl_only = true, |
| 1673 | .ret_type = RET_INTEGER, |
| 1674 | .arg1_type = ARG_PTR_TO_CTX, |
| 1675 | .arg2_type = ARG_PTR_TO_UNINIT_MEM, |
| 1676 | .arg3_type = ARG_CONST_SIZE, |
| 1677 | }; |
| 1678 | |
| 1679 | BPF_CALL_4(bpf_read_branch_records, struct bpf_perf_event_data_kern *, ctx, |
| 1680 | void *, buf, u32, size, u64, flags) |
| 1681 | { |
| 1682 | static const u32 br_entry_size = sizeof(struct perf_branch_entry); |
| 1683 | struct perf_branch_stack *br_stack = ctx->data->br_stack; |
| 1684 | u32 to_copy; |
| 1685 | |
| 1686 | if (unlikely(flags & ~BPF_F_GET_BRANCH_RECORDS_SIZE)) |
| 1687 | return -EINVAL; |
| 1688 | |
| 1689 | if (unlikely(!(ctx->data->sample_flags & PERF_SAMPLE_BRANCH_STACK))) |
| 1690 | return -ENOENT; |
| 1691 | |
| 1692 | if (unlikely(!br_stack)) |
| 1693 | return -ENOENT; |
| 1694 | |
| 1695 | if (flags & BPF_F_GET_BRANCH_RECORDS_SIZE) |
| 1696 | return br_stack->nr * br_entry_size; |
| 1697 | |
| 1698 | if (!buf || (size % br_entry_size != 0)) |
| 1699 | return -EINVAL; |
| 1700 | |
| 1701 | to_copy = min_t(u32, br_stack->nr * br_entry_size, size); |
| 1702 | memcpy(buf, br_stack->entries, to_copy); |
| 1703 | |
| 1704 | return to_copy; |
| 1705 | } |
| 1706 | |
| 1707 | static const struct bpf_func_proto bpf_read_branch_records_proto = { |
| 1708 | .func = bpf_read_branch_records, |
| 1709 | .gpl_only = true, |
| 1710 | .ret_type = RET_INTEGER, |
| 1711 | .arg1_type = ARG_PTR_TO_CTX, |
| 1712 | .arg2_type = ARG_PTR_TO_MEM_OR_NULL, |
| 1713 | .arg3_type = ARG_CONST_SIZE_OR_ZERO, |
| 1714 | .arg4_type = ARG_ANYTHING, |
| 1715 | }; |
| 1716 | |
| 1717 | static const struct bpf_func_proto * |
| 1718 | pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) |
| 1719 | { |
| 1720 | switch (func_id) { |
| 1721 | case BPF_FUNC_perf_event_output: |
| 1722 | return &bpf_perf_event_output_proto_tp; |
| 1723 | case BPF_FUNC_get_stackid: |
| 1724 | return &bpf_get_stackid_proto_pe; |
| 1725 | case BPF_FUNC_get_stack: |
| 1726 | return &bpf_get_stack_proto_pe; |
| 1727 | case BPF_FUNC_perf_prog_read_value: |
| 1728 | return &bpf_perf_prog_read_value_proto; |
| 1729 | case BPF_FUNC_read_branch_records: |
| 1730 | return &bpf_read_branch_records_proto; |
| 1731 | case BPF_FUNC_get_attach_cookie: |
| 1732 | return &bpf_get_attach_cookie_proto_pe; |
| 1733 | default: |
| 1734 | return bpf_tracing_func_proto(func_id, prog); |
| 1735 | } |
| 1736 | } |
| 1737 | |
| 1738 | /* |
| 1739 | * bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp |
| 1740 | * to avoid potential recursive reuse issue when/if tracepoints are added |
| 1741 | * inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack. |
| 1742 | * |
| 1743 | * Since raw tracepoints run despite bpf_prog_active, support concurrent usage |
| 1744 | * in normal, irq, and nmi context. |
| 1745 | */ |
| 1746 | struct bpf_raw_tp_regs { |
| 1747 | struct pt_regs regs[3]; |
| 1748 | }; |
| 1749 | static DEFINE_PER_CPU(struct bpf_raw_tp_regs, bpf_raw_tp_regs); |
| 1750 | static DEFINE_PER_CPU(int, bpf_raw_tp_nest_level); |
| 1751 | static struct pt_regs *get_bpf_raw_tp_regs(void) |
| 1752 | { |
| 1753 | struct bpf_raw_tp_regs *tp_regs = this_cpu_ptr(&bpf_raw_tp_regs); |
| 1754 | int nest_level = this_cpu_inc_return(bpf_raw_tp_nest_level); |
| 1755 | |
| 1756 | if (nest_level > ARRAY_SIZE(tp_regs->regs)) { |
| 1757 | this_cpu_dec(bpf_raw_tp_nest_level); |
| 1758 | return ERR_PTR(-EBUSY); |
| 1759 | } |
| 1760 | |
| 1761 | return &tp_regs->regs[nest_level - 1]; |
| 1762 | } |
| 1763 | |
| 1764 | static void put_bpf_raw_tp_regs(void) |
| 1765 | { |
| 1766 | this_cpu_dec(bpf_raw_tp_nest_level); |
| 1767 | } |
| 1768 | |
| 1769 | BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args, |
| 1770 | struct bpf_map *, map, u64, flags, void *, data, u64, size) |
| 1771 | { |
| 1772 | struct pt_regs *regs = get_bpf_raw_tp_regs(); |
| 1773 | int ret; |
| 1774 | |
| 1775 | if (IS_ERR(regs)) |
| 1776 | return PTR_ERR(regs); |
| 1777 | |
| 1778 | perf_fetch_caller_regs(regs); |
| 1779 | ret = ____bpf_perf_event_output(regs, map, flags, data, size); |
| 1780 | |
| 1781 | put_bpf_raw_tp_regs(); |
| 1782 | return ret; |
| 1783 | } |
| 1784 | |
| 1785 | static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = { |
| 1786 | .func = bpf_perf_event_output_raw_tp, |
| 1787 | .gpl_only = true, |
| 1788 | .ret_type = RET_INTEGER, |
| 1789 | .arg1_type = ARG_PTR_TO_CTX, |
| 1790 | .arg2_type = ARG_CONST_MAP_PTR, |
| 1791 | .arg3_type = ARG_ANYTHING, |
| 1792 | .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, |
| 1793 | .arg5_type = ARG_CONST_SIZE_OR_ZERO, |
| 1794 | }; |
| 1795 | |
| 1796 | extern const struct bpf_func_proto bpf_skb_output_proto; |
| 1797 | extern const struct bpf_func_proto bpf_xdp_output_proto; |
| 1798 | extern const struct bpf_func_proto bpf_xdp_get_buff_len_trace_proto; |
| 1799 | |
| 1800 | BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args, |
| 1801 | struct bpf_map *, map, u64, flags) |
| 1802 | { |
| 1803 | struct pt_regs *regs = get_bpf_raw_tp_regs(); |
| 1804 | int ret; |
| 1805 | |
| 1806 | if (IS_ERR(regs)) |
| 1807 | return PTR_ERR(regs); |
| 1808 | |
| 1809 | perf_fetch_caller_regs(regs); |
| 1810 | /* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */ |
| 1811 | ret = bpf_get_stackid((unsigned long) regs, (unsigned long) map, |
| 1812 | flags, 0, 0); |
| 1813 | put_bpf_raw_tp_regs(); |
| 1814 | return ret; |
| 1815 | } |
| 1816 | |
| 1817 | static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = { |
| 1818 | .func = bpf_get_stackid_raw_tp, |
| 1819 | .gpl_only = true, |
| 1820 | .ret_type = RET_INTEGER, |
| 1821 | .arg1_type = ARG_PTR_TO_CTX, |
| 1822 | .arg2_type = ARG_CONST_MAP_PTR, |
| 1823 | .arg3_type = ARG_ANYTHING, |
| 1824 | }; |
| 1825 | |
| 1826 | BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args, |
| 1827 | void *, buf, u32, size, u64, flags) |
| 1828 | { |
| 1829 | struct pt_regs *regs = get_bpf_raw_tp_regs(); |
| 1830 | int ret; |
| 1831 | |
| 1832 | if (IS_ERR(regs)) |
| 1833 | return PTR_ERR(regs); |
| 1834 | |
| 1835 | perf_fetch_caller_regs(regs); |
| 1836 | ret = bpf_get_stack((unsigned long) regs, (unsigned long) buf, |
| 1837 | (unsigned long) size, flags, 0); |
| 1838 | put_bpf_raw_tp_regs(); |
| 1839 | return ret; |
| 1840 | } |
| 1841 | |
| 1842 | static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = { |
| 1843 | .func = bpf_get_stack_raw_tp, |
| 1844 | .gpl_only = true, |
| 1845 | .ret_type = RET_INTEGER, |
| 1846 | .arg1_type = ARG_PTR_TO_CTX, |
| 1847 | .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, |
| 1848 | .arg3_type = ARG_CONST_SIZE_OR_ZERO, |
| 1849 | .arg4_type = ARG_ANYTHING, |
| 1850 | }; |
| 1851 | |
| 1852 | static const struct bpf_func_proto * |
| 1853 | raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) |
| 1854 | { |
| 1855 | switch (func_id) { |
| 1856 | case BPF_FUNC_perf_event_output: |
| 1857 | return &bpf_perf_event_output_proto_raw_tp; |
| 1858 | case BPF_FUNC_get_stackid: |
| 1859 | return &bpf_get_stackid_proto_raw_tp; |
| 1860 | case BPF_FUNC_get_stack: |
| 1861 | return &bpf_get_stack_proto_raw_tp; |
| 1862 | case BPF_FUNC_get_attach_cookie: |
| 1863 | return &bpf_get_attach_cookie_proto_tracing; |
| 1864 | default: |
| 1865 | return bpf_tracing_func_proto(func_id, prog); |
| 1866 | } |
| 1867 | } |
| 1868 | |
| 1869 | const struct bpf_func_proto * |
| 1870 | tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) |
| 1871 | { |
| 1872 | const struct bpf_func_proto *fn; |
| 1873 | |
| 1874 | switch (func_id) { |
| 1875 | #ifdef CONFIG_NET |
| 1876 | case BPF_FUNC_skb_output: |
| 1877 | return &bpf_skb_output_proto; |
| 1878 | case BPF_FUNC_xdp_output: |
| 1879 | return &bpf_xdp_output_proto; |
| 1880 | case BPF_FUNC_skc_to_tcp6_sock: |
| 1881 | return &bpf_skc_to_tcp6_sock_proto; |
| 1882 | case BPF_FUNC_skc_to_tcp_sock: |
| 1883 | return &bpf_skc_to_tcp_sock_proto; |
| 1884 | case BPF_FUNC_skc_to_tcp_timewait_sock: |
| 1885 | return &bpf_skc_to_tcp_timewait_sock_proto; |
| 1886 | case BPF_FUNC_skc_to_tcp_request_sock: |
| 1887 | return &bpf_skc_to_tcp_request_sock_proto; |
| 1888 | case BPF_FUNC_skc_to_udp6_sock: |
| 1889 | return &bpf_skc_to_udp6_sock_proto; |
| 1890 | case BPF_FUNC_skc_to_unix_sock: |
| 1891 | return &bpf_skc_to_unix_sock_proto; |
| 1892 | case BPF_FUNC_skc_to_mptcp_sock: |
| 1893 | return &bpf_skc_to_mptcp_sock_proto; |
| 1894 | case BPF_FUNC_sk_storage_get: |
| 1895 | return &bpf_sk_storage_get_tracing_proto; |
| 1896 | case BPF_FUNC_sk_storage_delete: |
| 1897 | return &bpf_sk_storage_delete_tracing_proto; |
| 1898 | case BPF_FUNC_sock_from_file: |
| 1899 | return &bpf_sock_from_file_proto; |
| 1900 | case BPF_FUNC_get_socket_cookie: |
| 1901 | return &bpf_get_socket_ptr_cookie_proto; |
| 1902 | case BPF_FUNC_xdp_get_buff_len: |
| 1903 | return &bpf_xdp_get_buff_len_trace_proto; |
| 1904 | #endif |
| 1905 | case BPF_FUNC_seq_printf: |
| 1906 | return prog->expected_attach_type == BPF_TRACE_ITER ? |
| 1907 | &bpf_seq_printf_proto : |
| 1908 | NULL; |
| 1909 | case BPF_FUNC_seq_write: |
| 1910 | return prog->expected_attach_type == BPF_TRACE_ITER ? |
| 1911 | &bpf_seq_write_proto : |
| 1912 | NULL; |
| 1913 | case BPF_FUNC_seq_printf_btf: |
| 1914 | return prog->expected_attach_type == BPF_TRACE_ITER ? |
| 1915 | &bpf_seq_printf_btf_proto : |
| 1916 | NULL; |
| 1917 | case BPF_FUNC_d_path: |
| 1918 | return &bpf_d_path_proto; |
| 1919 | case BPF_FUNC_get_func_arg: |
| 1920 | return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_proto : NULL; |
| 1921 | case BPF_FUNC_get_func_ret: |
| 1922 | return bpf_prog_has_trampoline(prog) ? &bpf_get_func_ret_proto : NULL; |
| 1923 | case BPF_FUNC_get_func_arg_cnt: |
| 1924 | return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_cnt_proto : NULL; |
| 1925 | case BPF_FUNC_get_attach_cookie: |
| 1926 | if (prog->type == BPF_PROG_TYPE_TRACING && |
| 1927 | prog->expected_attach_type == BPF_TRACE_RAW_TP) |
| 1928 | return &bpf_get_attach_cookie_proto_tracing; |
| 1929 | return bpf_prog_has_trampoline(prog) ? &bpf_get_attach_cookie_proto_tracing : NULL; |
| 1930 | default: |
| 1931 | fn = raw_tp_prog_func_proto(func_id, prog); |
| 1932 | if (!fn && prog->expected_attach_type == BPF_TRACE_ITER) |
| 1933 | fn = bpf_iter_get_func_proto(func_id, prog); |
| 1934 | return fn; |
| 1935 | } |
| 1936 | } |
| 1937 | |
| 1938 | static bool raw_tp_prog_is_valid_access(int off, int size, |
| 1939 | enum bpf_access_type type, |
| 1940 | const struct bpf_prog *prog, |
| 1941 | struct bpf_insn_access_aux *info) |
| 1942 | { |
| 1943 | return bpf_tracing_ctx_access(off, size, type); |
| 1944 | } |
| 1945 | |
| 1946 | static bool tracing_prog_is_valid_access(int off, int size, |
| 1947 | enum bpf_access_type type, |
| 1948 | const struct bpf_prog *prog, |
| 1949 | struct bpf_insn_access_aux *info) |
| 1950 | { |
| 1951 | return bpf_tracing_btf_ctx_access(off, size, type, prog, info); |
| 1952 | } |
| 1953 | |
| 1954 | int __weak bpf_prog_test_run_tracing(struct bpf_prog *prog, |
| 1955 | const union bpf_attr *kattr, |
| 1956 | union bpf_attr __user *uattr) |
| 1957 | { |
| 1958 | return -ENOTSUPP; |
| 1959 | } |
| 1960 | |
| 1961 | const struct bpf_verifier_ops raw_tracepoint_verifier_ops = { |
| 1962 | .get_func_proto = raw_tp_prog_func_proto, |
| 1963 | .is_valid_access = raw_tp_prog_is_valid_access, |
| 1964 | }; |
| 1965 | |
| 1966 | const struct bpf_prog_ops raw_tracepoint_prog_ops = { |
| 1967 | #ifdef CONFIG_NET |
| 1968 | .test_run = bpf_prog_test_run_raw_tp, |
| 1969 | #endif |
| 1970 | }; |
| 1971 | |
| 1972 | const struct bpf_verifier_ops tracing_verifier_ops = { |
| 1973 | .get_func_proto = tracing_prog_func_proto, |
| 1974 | .is_valid_access = tracing_prog_is_valid_access, |
| 1975 | }; |
| 1976 | |
| 1977 | const struct bpf_prog_ops tracing_prog_ops = { |
| 1978 | .test_run = bpf_prog_test_run_tracing, |
| 1979 | }; |
| 1980 | |
| 1981 | static bool raw_tp_writable_prog_is_valid_access(int off, int size, |
| 1982 | enum bpf_access_type type, |
| 1983 | const struct bpf_prog *prog, |
| 1984 | struct bpf_insn_access_aux *info) |
| 1985 | { |
| 1986 | if (off == 0) { |
| 1987 | if (size != sizeof(u64) || type != BPF_READ) |
| 1988 | return false; |
| 1989 | info->reg_type = PTR_TO_TP_BUFFER; |
| 1990 | } |
| 1991 | return raw_tp_prog_is_valid_access(off, size, type, prog, info); |
| 1992 | } |
| 1993 | |
| 1994 | const struct bpf_verifier_ops raw_tracepoint_writable_verifier_ops = { |
| 1995 | .get_func_proto = raw_tp_prog_func_proto, |
| 1996 | .is_valid_access = raw_tp_writable_prog_is_valid_access, |
| 1997 | }; |
| 1998 | |
| 1999 | const struct bpf_prog_ops raw_tracepoint_writable_prog_ops = { |
| 2000 | }; |
| 2001 | |
| 2002 | static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type, |
| 2003 | const struct bpf_prog *prog, |
| 2004 | struct bpf_insn_access_aux *info) |
| 2005 | { |
| 2006 | const int size_u64 = sizeof(u64); |
| 2007 | |
| 2008 | if (off < 0 || off >= sizeof(struct bpf_perf_event_data)) |
| 2009 | return false; |
| 2010 | if (type != BPF_READ) |
| 2011 | return false; |
| 2012 | if (off % size != 0) { |
| 2013 | if (sizeof(unsigned long) != 4) |
| 2014 | return false; |
| 2015 | if (size != 8) |
| 2016 | return false; |
| 2017 | if (off % size != 4) |
| 2018 | return false; |
| 2019 | } |
| 2020 | |
| 2021 | switch (off) { |
| 2022 | case bpf_ctx_range(struct bpf_perf_event_data, sample_period): |
| 2023 | bpf_ctx_record_field_size(info, size_u64); |
| 2024 | if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) |
| 2025 | return false; |
| 2026 | break; |
| 2027 | case bpf_ctx_range(struct bpf_perf_event_data, addr): |
| 2028 | bpf_ctx_record_field_size(info, size_u64); |
| 2029 | if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) |
| 2030 | return false; |
| 2031 | break; |
| 2032 | default: |
| 2033 | if (size != sizeof(long)) |
| 2034 | return false; |
| 2035 | } |
| 2036 | |
| 2037 | return true; |
| 2038 | } |
| 2039 | |
| 2040 | static u32 pe_prog_convert_ctx_access(enum bpf_access_type type, |
| 2041 | const struct bpf_insn *si, |
| 2042 | struct bpf_insn *insn_buf, |
| 2043 | struct bpf_prog *prog, u32 *target_size) |
| 2044 | { |
| 2045 | struct bpf_insn *insn = insn_buf; |
| 2046 | |
| 2047 | switch (si->off) { |
| 2048 | case offsetof(struct bpf_perf_event_data, sample_period): |
| 2049 | *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, |
| 2050 | data), si->dst_reg, si->src_reg, |
| 2051 | offsetof(struct bpf_perf_event_data_kern, data)); |
| 2052 | *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, |
| 2053 | bpf_target_off(struct perf_sample_data, period, 8, |
| 2054 | target_size)); |
| 2055 | break; |
| 2056 | case offsetof(struct bpf_perf_event_data, addr): |
| 2057 | *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, |
| 2058 | data), si->dst_reg, si->src_reg, |
| 2059 | offsetof(struct bpf_perf_event_data_kern, data)); |
| 2060 | *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, |
| 2061 | bpf_target_off(struct perf_sample_data, addr, 8, |
| 2062 | target_size)); |
| 2063 | break; |
| 2064 | default: |
| 2065 | *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, |
| 2066 | regs), si->dst_reg, si->src_reg, |
| 2067 | offsetof(struct bpf_perf_event_data_kern, regs)); |
| 2068 | *insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg, |
| 2069 | si->off); |
| 2070 | break; |
| 2071 | } |
| 2072 | |
| 2073 | return insn - insn_buf; |
| 2074 | } |
| 2075 | |
| 2076 | const struct bpf_verifier_ops perf_event_verifier_ops = { |
| 2077 | .get_func_proto = pe_prog_func_proto, |
| 2078 | .is_valid_access = pe_prog_is_valid_access, |
| 2079 | .convert_ctx_access = pe_prog_convert_ctx_access, |
| 2080 | }; |
| 2081 | |
| 2082 | const struct bpf_prog_ops perf_event_prog_ops = { |
| 2083 | }; |
| 2084 | |
| 2085 | static DEFINE_MUTEX(bpf_event_mutex); |
| 2086 | |
| 2087 | #define BPF_TRACE_MAX_PROGS 64 |
| 2088 | |
| 2089 | int perf_event_attach_bpf_prog(struct perf_event *event, |
| 2090 | struct bpf_prog *prog, |
| 2091 | u64 bpf_cookie) |
| 2092 | { |
| 2093 | struct bpf_prog_array *old_array; |
| 2094 | struct bpf_prog_array *new_array; |
| 2095 | int ret = -EEXIST; |
| 2096 | |
| 2097 | /* |
| 2098 | * Kprobe override only works if they are on the function entry, |
| 2099 | * and only if they are on the opt-in list. |
| 2100 | */ |
| 2101 | if (prog->kprobe_override && |
| 2102 | (!trace_kprobe_on_func_entry(event->tp_event) || |
| 2103 | !trace_kprobe_error_injectable(event->tp_event))) |
| 2104 | return -EINVAL; |
| 2105 | |
| 2106 | mutex_lock(&bpf_event_mutex); |
| 2107 | |
| 2108 | if (event->prog) |
| 2109 | goto unlock; |
| 2110 | |
| 2111 | old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); |
| 2112 | if (old_array && |
| 2113 | bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) { |
| 2114 | ret = -E2BIG; |
| 2115 | goto unlock; |
| 2116 | } |
| 2117 | |
| 2118 | ret = bpf_prog_array_copy(old_array, NULL, prog, bpf_cookie, &new_array); |
| 2119 | if (ret < 0) |
| 2120 | goto unlock; |
| 2121 | |
| 2122 | /* set the new array to event->tp_event and set event->prog */ |
| 2123 | event->prog = prog; |
| 2124 | event->bpf_cookie = bpf_cookie; |
| 2125 | rcu_assign_pointer(event->tp_event->prog_array, new_array); |
| 2126 | bpf_prog_array_free_sleepable(old_array); |
| 2127 | |
| 2128 | unlock: |
| 2129 | mutex_unlock(&bpf_event_mutex); |
| 2130 | return ret; |
| 2131 | } |
| 2132 | |
| 2133 | void perf_event_detach_bpf_prog(struct perf_event *event) |
| 2134 | { |
| 2135 | struct bpf_prog_array *old_array; |
| 2136 | struct bpf_prog_array *new_array; |
| 2137 | struct bpf_prog *prog = NULL; |
| 2138 | int ret; |
| 2139 | |
| 2140 | mutex_lock(&bpf_event_mutex); |
| 2141 | |
| 2142 | if (!event->prog) |
| 2143 | goto unlock; |
| 2144 | |
| 2145 | old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); |
| 2146 | if (!old_array) |
| 2147 | goto put; |
| 2148 | |
| 2149 | ret = bpf_prog_array_copy(old_array, event->prog, NULL, 0, &new_array); |
| 2150 | if (ret < 0) { |
| 2151 | bpf_prog_array_delete_safe(old_array, event->prog); |
| 2152 | } else { |
| 2153 | rcu_assign_pointer(event->tp_event->prog_array, new_array); |
| 2154 | bpf_prog_array_free_sleepable(old_array); |
| 2155 | } |
| 2156 | |
| 2157 | put: |
| 2158 | prog = event->prog; |
| 2159 | event->prog = NULL; |
| 2160 | |
| 2161 | unlock: |
| 2162 | mutex_unlock(&bpf_event_mutex); |
| 2163 | |
| 2164 | if (prog) { |
| 2165 | /* |
| 2166 | * It could be that the bpf_prog is not sleepable (and will be freed |
| 2167 | * via normal RCU), but is called from a point that supports sleepable |
| 2168 | * programs and uses tasks-trace-RCU. |
| 2169 | */ |
| 2170 | synchronize_rcu_tasks_trace(); |
| 2171 | |
| 2172 | bpf_prog_put(prog); |
| 2173 | } |
| 2174 | } |
| 2175 | |
| 2176 | int perf_event_query_prog_array(struct perf_event *event, void __user *info) |
| 2177 | { |
| 2178 | struct perf_event_query_bpf __user *uquery = info; |
| 2179 | struct perf_event_query_bpf query = {}; |
| 2180 | struct bpf_prog_array *progs; |
| 2181 | u32 *ids, prog_cnt, ids_len; |
| 2182 | int ret; |
| 2183 | |
| 2184 | if (!perfmon_capable()) |
| 2185 | return -EPERM; |
| 2186 | if (event->attr.type != PERF_TYPE_TRACEPOINT) |
| 2187 | return -EINVAL; |
| 2188 | if (copy_from_user(&query, uquery, sizeof(query))) |
| 2189 | return -EFAULT; |
| 2190 | |
| 2191 | ids_len = query.ids_len; |
| 2192 | if (ids_len > BPF_TRACE_MAX_PROGS) |
| 2193 | return -E2BIG; |
| 2194 | ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN); |
| 2195 | if (!ids) |
| 2196 | return -ENOMEM; |
| 2197 | /* |
| 2198 | * The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which |
| 2199 | * is required when user only wants to check for uquery->prog_cnt. |
| 2200 | * There is no need to check for it since the case is handled |
| 2201 | * gracefully in bpf_prog_array_copy_info. |
| 2202 | */ |
| 2203 | |
| 2204 | mutex_lock(&bpf_event_mutex); |
| 2205 | progs = bpf_event_rcu_dereference(event->tp_event->prog_array); |
| 2206 | ret = bpf_prog_array_copy_info(progs, ids, ids_len, &prog_cnt); |
| 2207 | mutex_unlock(&bpf_event_mutex); |
| 2208 | |
| 2209 | if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) || |
| 2210 | copy_to_user(uquery->ids, ids, ids_len * sizeof(u32))) |
| 2211 | ret = -EFAULT; |
| 2212 | |
| 2213 | kfree(ids); |
| 2214 | return ret; |
| 2215 | } |
| 2216 | |
| 2217 | extern struct bpf_raw_event_map __start__bpf_raw_tp[]; |
| 2218 | extern struct bpf_raw_event_map __stop__bpf_raw_tp[]; |
| 2219 | |
| 2220 | struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name) |
| 2221 | { |
| 2222 | struct bpf_raw_event_map *btp = __start__bpf_raw_tp; |
| 2223 | |
| 2224 | for (; btp < __stop__bpf_raw_tp; btp++) { |
| 2225 | if (!strcmp(btp->tp->name, name)) |
| 2226 | return btp; |
| 2227 | } |
| 2228 | |
| 2229 | return bpf_get_raw_tracepoint_module(name); |
| 2230 | } |
| 2231 | |
| 2232 | void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp) |
| 2233 | { |
| 2234 | struct module *mod; |
| 2235 | |
| 2236 | guard(rcu)(); |
| 2237 | mod = __module_address((unsigned long)btp); |
| 2238 | module_put(mod); |
| 2239 | } |
| 2240 | |
| 2241 | static __always_inline |
| 2242 | void __bpf_trace_run(struct bpf_raw_tp_link *link, u64 *args) |
| 2243 | { |
| 2244 | struct bpf_prog *prog = link->link.prog; |
| 2245 | struct bpf_run_ctx *old_run_ctx; |
| 2246 | struct bpf_trace_run_ctx run_ctx; |
| 2247 | |
| 2248 | cant_sleep(); |
| 2249 | if (unlikely(this_cpu_inc_return(*(prog->active)) != 1)) { |
| 2250 | bpf_prog_inc_misses_counter(prog); |
| 2251 | goto out; |
| 2252 | } |
| 2253 | |
| 2254 | run_ctx.bpf_cookie = link->cookie; |
| 2255 | old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx); |
| 2256 | |
| 2257 | rcu_read_lock(); |
| 2258 | (void) bpf_prog_run(prog, args); |
| 2259 | rcu_read_unlock(); |
| 2260 | |
| 2261 | bpf_reset_run_ctx(old_run_ctx); |
| 2262 | out: |
| 2263 | this_cpu_dec(*(prog->active)); |
| 2264 | } |
| 2265 | |
| 2266 | #define UNPACK(...) __VA_ARGS__ |
| 2267 | #define REPEAT_1(FN, DL, X, ...) FN(X) |
| 2268 | #define REPEAT_2(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__) |
| 2269 | #define REPEAT_3(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_2(FN, DL, __VA_ARGS__) |
| 2270 | #define REPEAT_4(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_3(FN, DL, __VA_ARGS__) |
| 2271 | #define REPEAT_5(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_4(FN, DL, __VA_ARGS__) |
| 2272 | #define REPEAT_6(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_5(FN, DL, __VA_ARGS__) |
| 2273 | #define REPEAT_7(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_6(FN, DL, __VA_ARGS__) |
| 2274 | #define REPEAT_8(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_7(FN, DL, __VA_ARGS__) |
| 2275 | #define REPEAT_9(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_8(FN, DL, __VA_ARGS__) |
| 2276 | #define REPEAT_10(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_9(FN, DL, __VA_ARGS__) |
| 2277 | #define REPEAT_11(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_10(FN, DL, __VA_ARGS__) |
| 2278 | #define REPEAT_12(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_11(FN, DL, __VA_ARGS__) |
| 2279 | #define REPEAT(X, FN, DL, ...) REPEAT_##X(FN, DL, __VA_ARGS__) |
| 2280 | |
| 2281 | #define SARG(X) u64 arg##X |
| 2282 | #define COPY(X) args[X] = arg##X |
| 2283 | |
| 2284 | #define __DL_COM (,) |
| 2285 | #define __DL_SEM (;) |
| 2286 | |
| 2287 | #define __SEQ_0_11 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 |
| 2288 | |
| 2289 | #define BPF_TRACE_DEFN_x(x) \ |
| 2290 | void bpf_trace_run##x(struct bpf_raw_tp_link *link, \ |
| 2291 | REPEAT(x, SARG, __DL_COM, __SEQ_0_11)) \ |
| 2292 | { \ |
| 2293 | u64 args[x]; \ |
| 2294 | REPEAT(x, COPY, __DL_SEM, __SEQ_0_11); \ |
| 2295 | __bpf_trace_run(link, args); \ |
| 2296 | } \ |
| 2297 | EXPORT_SYMBOL_GPL(bpf_trace_run##x) |
| 2298 | BPF_TRACE_DEFN_x(1); |
| 2299 | BPF_TRACE_DEFN_x(2); |
| 2300 | BPF_TRACE_DEFN_x(3); |
| 2301 | BPF_TRACE_DEFN_x(4); |
| 2302 | BPF_TRACE_DEFN_x(5); |
| 2303 | BPF_TRACE_DEFN_x(6); |
| 2304 | BPF_TRACE_DEFN_x(7); |
| 2305 | BPF_TRACE_DEFN_x(8); |
| 2306 | BPF_TRACE_DEFN_x(9); |
| 2307 | BPF_TRACE_DEFN_x(10); |
| 2308 | BPF_TRACE_DEFN_x(11); |
| 2309 | BPF_TRACE_DEFN_x(12); |
| 2310 | |
| 2311 | int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_raw_tp_link *link) |
| 2312 | { |
| 2313 | struct tracepoint *tp = btp->tp; |
| 2314 | struct bpf_prog *prog = link->link.prog; |
| 2315 | |
| 2316 | /* |
| 2317 | * check that program doesn't access arguments beyond what's |
| 2318 | * available in this tracepoint |
| 2319 | */ |
| 2320 | if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64)) |
| 2321 | return -EINVAL; |
| 2322 | |
| 2323 | if (prog->aux->max_tp_access > btp->writable_size) |
| 2324 | return -EINVAL; |
| 2325 | |
| 2326 | return tracepoint_probe_register_may_exist(tp, (void *)btp->bpf_func, link); |
| 2327 | } |
| 2328 | |
| 2329 | int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_raw_tp_link *link) |
| 2330 | { |
| 2331 | return tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, link); |
| 2332 | } |
| 2333 | |
| 2334 | int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id, |
| 2335 | u32 *fd_type, const char **buf, |
| 2336 | u64 *probe_offset, u64 *probe_addr, |
| 2337 | unsigned long *missed) |
| 2338 | { |
| 2339 | bool is_tracepoint, is_syscall_tp; |
| 2340 | struct bpf_prog *prog; |
| 2341 | int flags, err = 0; |
| 2342 | |
| 2343 | prog = event->prog; |
| 2344 | if (!prog) |
| 2345 | return -ENOENT; |
| 2346 | |
| 2347 | /* not supporting BPF_PROG_TYPE_PERF_EVENT yet */ |
| 2348 | if (prog->type == BPF_PROG_TYPE_PERF_EVENT) |
| 2349 | return -EOPNOTSUPP; |
| 2350 | |
| 2351 | *prog_id = prog->aux->id; |
| 2352 | flags = event->tp_event->flags; |
| 2353 | is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT; |
| 2354 | is_syscall_tp = is_syscall_trace_event(event->tp_event); |
| 2355 | |
| 2356 | if (is_tracepoint || is_syscall_tp) { |
| 2357 | *buf = is_tracepoint ? event->tp_event->tp->name |
| 2358 | : event->tp_event->name; |
| 2359 | /* We allow NULL pointer for tracepoint */ |
| 2360 | if (fd_type) |
| 2361 | *fd_type = BPF_FD_TYPE_TRACEPOINT; |
| 2362 | if (probe_offset) |
| 2363 | *probe_offset = 0x0; |
| 2364 | if (probe_addr) |
| 2365 | *probe_addr = 0x0; |
| 2366 | } else { |
| 2367 | /* kprobe/uprobe */ |
| 2368 | err = -EOPNOTSUPP; |
| 2369 | #ifdef CONFIG_KPROBE_EVENTS |
| 2370 | if (flags & TRACE_EVENT_FL_KPROBE) |
| 2371 | err = bpf_get_kprobe_info(event, fd_type, buf, |
| 2372 | probe_offset, probe_addr, missed, |
| 2373 | event->attr.type == PERF_TYPE_TRACEPOINT); |
| 2374 | #endif |
| 2375 | #ifdef CONFIG_UPROBE_EVENTS |
| 2376 | if (flags & TRACE_EVENT_FL_UPROBE) |
| 2377 | err = bpf_get_uprobe_info(event, fd_type, buf, |
| 2378 | probe_offset, probe_addr, |
| 2379 | event->attr.type == PERF_TYPE_TRACEPOINT); |
| 2380 | #endif |
| 2381 | } |
| 2382 | |
| 2383 | return err; |
| 2384 | } |
| 2385 | |
| 2386 | static int __init send_signal_irq_work_init(void) |
| 2387 | { |
| 2388 | int cpu; |
| 2389 | struct send_signal_irq_work *work; |
| 2390 | |
| 2391 | for_each_possible_cpu(cpu) { |
| 2392 | work = per_cpu_ptr(&send_signal_work, cpu); |
| 2393 | init_irq_work(&work->irq_work, do_bpf_send_signal); |
| 2394 | } |
| 2395 | return 0; |
| 2396 | } |
| 2397 | |
| 2398 | subsys_initcall(send_signal_irq_work_init); |
| 2399 | |
| 2400 | #ifdef CONFIG_MODULES |
| 2401 | static int bpf_event_notify(struct notifier_block *nb, unsigned long op, |
| 2402 | void *module) |
| 2403 | { |
| 2404 | struct bpf_trace_module *btm, *tmp; |
| 2405 | struct module *mod = module; |
| 2406 | int ret = 0; |
| 2407 | |
| 2408 | if (mod->num_bpf_raw_events == 0 || |
| 2409 | (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING)) |
| 2410 | goto out; |
| 2411 | |
| 2412 | mutex_lock(&bpf_module_mutex); |
| 2413 | |
| 2414 | switch (op) { |
| 2415 | case MODULE_STATE_COMING: |
| 2416 | btm = kzalloc(sizeof(*btm), GFP_KERNEL); |
| 2417 | if (btm) { |
| 2418 | btm->module = module; |
| 2419 | list_add(&btm->list, &bpf_trace_modules); |
| 2420 | } else { |
| 2421 | ret = -ENOMEM; |
| 2422 | } |
| 2423 | break; |
| 2424 | case MODULE_STATE_GOING: |
| 2425 | list_for_each_entry_safe(btm, tmp, &bpf_trace_modules, list) { |
| 2426 | if (btm->module == module) { |
| 2427 | list_del(&btm->list); |
| 2428 | kfree(btm); |
| 2429 | break; |
| 2430 | } |
| 2431 | } |
| 2432 | break; |
| 2433 | } |
| 2434 | |
| 2435 | mutex_unlock(&bpf_module_mutex); |
| 2436 | |
| 2437 | out: |
| 2438 | return notifier_from_errno(ret); |
| 2439 | } |
| 2440 | |
| 2441 | static struct notifier_block bpf_module_nb = { |
| 2442 | .notifier_call = bpf_event_notify, |
| 2443 | }; |
| 2444 | |
| 2445 | static int __init bpf_event_init(void) |
| 2446 | { |
| 2447 | register_module_notifier(&bpf_module_nb); |
| 2448 | return 0; |
| 2449 | } |
| 2450 | |
| 2451 | fs_initcall(bpf_event_init); |
| 2452 | #endif /* CONFIG_MODULES */ |
| 2453 | |
| 2454 | struct bpf_session_run_ctx { |
| 2455 | struct bpf_run_ctx run_ctx; |
| 2456 | bool is_return; |
| 2457 | void *data; |
| 2458 | }; |
| 2459 | |
| 2460 | #ifdef CONFIG_FPROBE |
| 2461 | struct bpf_kprobe_multi_link { |
| 2462 | struct bpf_link link; |
| 2463 | struct fprobe fp; |
| 2464 | unsigned long *addrs; |
| 2465 | u64 *cookies; |
| 2466 | u32 cnt; |
| 2467 | u32 mods_cnt; |
| 2468 | struct module **mods; |
| 2469 | u32 flags; |
| 2470 | }; |
| 2471 | |
| 2472 | struct bpf_kprobe_multi_run_ctx { |
| 2473 | struct bpf_session_run_ctx session_ctx; |
| 2474 | struct bpf_kprobe_multi_link *link; |
| 2475 | unsigned long entry_ip; |
| 2476 | }; |
| 2477 | |
| 2478 | struct user_syms { |
| 2479 | const char **syms; |
| 2480 | char *buf; |
| 2481 | }; |
| 2482 | |
| 2483 | #ifndef CONFIG_HAVE_FTRACE_REGS_HAVING_PT_REGS |
| 2484 | static DEFINE_PER_CPU(struct pt_regs, bpf_kprobe_multi_pt_regs); |
| 2485 | #define bpf_kprobe_multi_pt_regs_ptr() this_cpu_ptr(&bpf_kprobe_multi_pt_regs) |
| 2486 | #else |
| 2487 | #define bpf_kprobe_multi_pt_regs_ptr() (NULL) |
| 2488 | #endif |
| 2489 | |
| 2490 | static unsigned long ftrace_get_entry_ip(unsigned long fentry_ip) |
| 2491 | { |
| 2492 | unsigned long ip = ftrace_get_symaddr(fentry_ip); |
| 2493 | |
| 2494 | return ip ? : fentry_ip; |
| 2495 | } |
| 2496 | |
| 2497 | static int copy_user_syms(struct user_syms *us, unsigned long __user *usyms, u32 cnt) |
| 2498 | { |
| 2499 | unsigned long __user usymbol; |
| 2500 | const char **syms = NULL; |
| 2501 | char *buf = NULL, *p; |
| 2502 | int err = -ENOMEM; |
| 2503 | unsigned int i; |
| 2504 | |
| 2505 | syms = kvmalloc_array(cnt, sizeof(*syms), GFP_KERNEL); |
| 2506 | if (!syms) |
| 2507 | goto error; |
| 2508 | |
| 2509 | buf = kvmalloc_array(cnt, KSYM_NAME_LEN, GFP_KERNEL); |
| 2510 | if (!buf) |
| 2511 | goto error; |
| 2512 | |
| 2513 | for (p = buf, i = 0; i < cnt; i++) { |
| 2514 | if (__get_user(usymbol, usyms + i)) { |
| 2515 | err = -EFAULT; |
| 2516 | goto error; |
| 2517 | } |
| 2518 | err = strncpy_from_user(p, (const char __user *) usymbol, KSYM_NAME_LEN); |
| 2519 | if (err == KSYM_NAME_LEN) |
| 2520 | err = -E2BIG; |
| 2521 | if (err < 0) |
| 2522 | goto error; |
| 2523 | syms[i] = p; |
| 2524 | p += err + 1; |
| 2525 | } |
| 2526 | |
| 2527 | us->syms = syms; |
| 2528 | us->buf = buf; |
| 2529 | return 0; |
| 2530 | |
| 2531 | error: |
| 2532 | if (err) { |
| 2533 | kvfree(syms); |
| 2534 | kvfree(buf); |
| 2535 | } |
| 2536 | return err; |
| 2537 | } |
| 2538 | |
| 2539 | static void kprobe_multi_put_modules(struct module **mods, u32 cnt) |
| 2540 | { |
| 2541 | u32 i; |
| 2542 | |
| 2543 | for (i = 0; i < cnt; i++) |
| 2544 | module_put(mods[i]); |
| 2545 | } |
| 2546 | |
| 2547 | static void free_user_syms(struct user_syms *us) |
| 2548 | { |
| 2549 | kvfree(us->syms); |
| 2550 | kvfree(us->buf); |
| 2551 | } |
| 2552 | |
| 2553 | static void bpf_kprobe_multi_link_release(struct bpf_link *link) |
| 2554 | { |
| 2555 | struct bpf_kprobe_multi_link *kmulti_link; |
| 2556 | |
| 2557 | kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); |
| 2558 | unregister_fprobe(&kmulti_link->fp); |
| 2559 | kprobe_multi_put_modules(kmulti_link->mods, kmulti_link->mods_cnt); |
| 2560 | } |
| 2561 | |
| 2562 | static void bpf_kprobe_multi_link_dealloc(struct bpf_link *link) |
| 2563 | { |
| 2564 | struct bpf_kprobe_multi_link *kmulti_link; |
| 2565 | |
| 2566 | kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); |
| 2567 | kvfree(kmulti_link->addrs); |
| 2568 | kvfree(kmulti_link->cookies); |
| 2569 | kfree(kmulti_link->mods); |
| 2570 | kfree(kmulti_link); |
| 2571 | } |
| 2572 | |
| 2573 | static int bpf_kprobe_multi_link_fill_link_info(const struct bpf_link *link, |
| 2574 | struct bpf_link_info *info) |
| 2575 | { |
| 2576 | u64 __user *ucookies = u64_to_user_ptr(info->kprobe_multi.cookies); |
| 2577 | u64 __user *uaddrs = u64_to_user_ptr(info->kprobe_multi.addrs); |
| 2578 | struct bpf_kprobe_multi_link *kmulti_link; |
| 2579 | u32 ucount = info->kprobe_multi.count; |
| 2580 | int err = 0, i; |
| 2581 | |
| 2582 | if (!uaddrs ^ !ucount) |
| 2583 | return -EINVAL; |
| 2584 | if (ucookies && !ucount) |
| 2585 | return -EINVAL; |
| 2586 | |
| 2587 | kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); |
| 2588 | info->kprobe_multi.count = kmulti_link->cnt; |
| 2589 | info->kprobe_multi.flags = kmulti_link->flags; |
| 2590 | info->kprobe_multi.missed = kmulti_link->fp.nmissed; |
| 2591 | |
| 2592 | if (!uaddrs) |
| 2593 | return 0; |
| 2594 | if (ucount < kmulti_link->cnt) |
| 2595 | err = -ENOSPC; |
| 2596 | else |
| 2597 | ucount = kmulti_link->cnt; |
| 2598 | |
| 2599 | if (ucookies) { |
| 2600 | if (kmulti_link->cookies) { |
| 2601 | if (copy_to_user(ucookies, kmulti_link->cookies, ucount * sizeof(u64))) |
| 2602 | return -EFAULT; |
| 2603 | } else { |
| 2604 | for (i = 0; i < ucount; i++) { |
| 2605 | if (put_user(0, ucookies + i)) |
| 2606 | return -EFAULT; |
| 2607 | } |
| 2608 | } |
| 2609 | } |
| 2610 | |
| 2611 | if (kallsyms_show_value(current_cred())) { |
| 2612 | if (copy_to_user(uaddrs, kmulti_link->addrs, ucount * sizeof(u64))) |
| 2613 | return -EFAULT; |
| 2614 | } else { |
| 2615 | for (i = 0; i < ucount; i++) { |
| 2616 | if (put_user(0, uaddrs + i)) |
| 2617 | return -EFAULT; |
| 2618 | } |
| 2619 | } |
| 2620 | return err; |
| 2621 | } |
| 2622 | |
| 2623 | static const struct bpf_link_ops bpf_kprobe_multi_link_lops = { |
| 2624 | .release = bpf_kprobe_multi_link_release, |
| 2625 | .dealloc_deferred = bpf_kprobe_multi_link_dealloc, |
| 2626 | .fill_link_info = bpf_kprobe_multi_link_fill_link_info, |
| 2627 | }; |
| 2628 | |
| 2629 | static void bpf_kprobe_multi_cookie_swap(void *a, void *b, int size, const void *priv) |
| 2630 | { |
| 2631 | const struct bpf_kprobe_multi_link *link = priv; |
| 2632 | unsigned long *addr_a = a, *addr_b = b; |
| 2633 | u64 *cookie_a, *cookie_b; |
| 2634 | |
| 2635 | cookie_a = link->cookies + (addr_a - link->addrs); |
| 2636 | cookie_b = link->cookies + (addr_b - link->addrs); |
| 2637 | |
| 2638 | /* swap addr_a/addr_b and cookie_a/cookie_b values */ |
| 2639 | swap(*addr_a, *addr_b); |
| 2640 | swap(*cookie_a, *cookie_b); |
| 2641 | } |
| 2642 | |
| 2643 | static int bpf_kprobe_multi_addrs_cmp(const void *a, const void *b) |
| 2644 | { |
| 2645 | const unsigned long *addr_a = a, *addr_b = b; |
| 2646 | |
| 2647 | if (*addr_a == *addr_b) |
| 2648 | return 0; |
| 2649 | return *addr_a < *addr_b ? -1 : 1; |
| 2650 | } |
| 2651 | |
| 2652 | static int bpf_kprobe_multi_cookie_cmp(const void *a, const void *b, const void *priv) |
| 2653 | { |
| 2654 | return bpf_kprobe_multi_addrs_cmp(a, b); |
| 2655 | } |
| 2656 | |
| 2657 | static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx) |
| 2658 | { |
| 2659 | struct bpf_kprobe_multi_run_ctx *run_ctx; |
| 2660 | struct bpf_kprobe_multi_link *link; |
| 2661 | u64 *cookie, entry_ip; |
| 2662 | unsigned long *addr; |
| 2663 | |
| 2664 | if (WARN_ON_ONCE(!ctx)) |
| 2665 | return 0; |
| 2666 | run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, |
| 2667 | session_ctx.run_ctx); |
| 2668 | link = run_ctx->link; |
| 2669 | if (!link->cookies) |
| 2670 | return 0; |
| 2671 | entry_ip = run_ctx->entry_ip; |
| 2672 | addr = bsearch(&entry_ip, link->addrs, link->cnt, sizeof(entry_ip), |
| 2673 | bpf_kprobe_multi_addrs_cmp); |
| 2674 | if (!addr) |
| 2675 | return 0; |
| 2676 | cookie = link->cookies + (addr - link->addrs); |
| 2677 | return *cookie; |
| 2678 | } |
| 2679 | |
| 2680 | static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx) |
| 2681 | { |
| 2682 | struct bpf_kprobe_multi_run_ctx *run_ctx; |
| 2683 | |
| 2684 | run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, |
| 2685 | session_ctx.run_ctx); |
| 2686 | return run_ctx->entry_ip; |
| 2687 | } |
| 2688 | |
| 2689 | static int |
| 2690 | kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link, |
| 2691 | unsigned long entry_ip, struct ftrace_regs *fregs, |
| 2692 | bool is_return, void *data) |
| 2693 | { |
| 2694 | struct bpf_kprobe_multi_run_ctx run_ctx = { |
| 2695 | .session_ctx = { |
| 2696 | .is_return = is_return, |
| 2697 | .data = data, |
| 2698 | }, |
| 2699 | .link = link, |
| 2700 | .entry_ip = entry_ip, |
| 2701 | }; |
| 2702 | struct bpf_run_ctx *old_run_ctx; |
| 2703 | struct pt_regs *regs; |
| 2704 | int err; |
| 2705 | |
| 2706 | if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) { |
| 2707 | bpf_prog_inc_misses_counter(link->link.prog); |
| 2708 | err = 1; |
| 2709 | goto out; |
| 2710 | } |
| 2711 | |
| 2712 | migrate_disable(); |
| 2713 | rcu_read_lock(); |
| 2714 | regs = ftrace_partial_regs(fregs, bpf_kprobe_multi_pt_regs_ptr()); |
| 2715 | old_run_ctx = bpf_set_run_ctx(&run_ctx.session_ctx.run_ctx); |
| 2716 | err = bpf_prog_run(link->link.prog, regs); |
| 2717 | bpf_reset_run_ctx(old_run_ctx); |
| 2718 | rcu_read_unlock(); |
| 2719 | migrate_enable(); |
| 2720 | |
| 2721 | out: |
| 2722 | __this_cpu_dec(bpf_prog_active); |
| 2723 | return err; |
| 2724 | } |
| 2725 | |
| 2726 | static int |
| 2727 | kprobe_multi_link_handler(struct fprobe *fp, unsigned long fentry_ip, |
| 2728 | unsigned long ret_ip, struct ftrace_regs *fregs, |
| 2729 | void *data) |
| 2730 | { |
| 2731 | struct bpf_kprobe_multi_link *link; |
| 2732 | int err; |
| 2733 | |
| 2734 | link = container_of(fp, struct bpf_kprobe_multi_link, fp); |
| 2735 | err = kprobe_multi_link_prog_run(link, ftrace_get_entry_ip(fentry_ip), |
| 2736 | fregs, false, data); |
| 2737 | return is_kprobe_session(link->link.prog) ? err : 0; |
| 2738 | } |
| 2739 | |
| 2740 | static void |
| 2741 | kprobe_multi_link_exit_handler(struct fprobe *fp, unsigned long fentry_ip, |
| 2742 | unsigned long ret_ip, struct ftrace_regs *fregs, |
| 2743 | void *data) |
| 2744 | { |
| 2745 | struct bpf_kprobe_multi_link *link; |
| 2746 | |
| 2747 | link = container_of(fp, struct bpf_kprobe_multi_link, fp); |
| 2748 | kprobe_multi_link_prog_run(link, ftrace_get_entry_ip(fentry_ip), |
| 2749 | fregs, true, data); |
| 2750 | } |
| 2751 | |
| 2752 | static int symbols_cmp_r(const void *a, const void *b, const void *priv) |
| 2753 | { |
| 2754 | const char **str_a = (const char **) a; |
| 2755 | const char **str_b = (const char **) b; |
| 2756 | |
| 2757 | return strcmp(*str_a, *str_b); |
| 2758 | } |
| 2759 | |
| 2760 | struct multi_symbols_sort { |
| 2761 | const char **funcs; |
| 2762 | u64 *cookies; |
| 2763 | }; |
| 2764 | |
| 2765 | static void symbols_swap_r(void *a, void *b, int size, const void *priv) |
| 2766 | { |
| 2767 | const struct multi_symbols_sort *data = priv; |
| 2768 | const char **name_a = a, **name_b = b; |
| 2769 | |
| 2770 | swap(*name_a, *name_b); |
| 2771 | |
| 2772 | /* If defined, swap also related cookies. */ |
| 2773 | if (data->cookies) { |
| 2774 | u64 *cookie_a, *cookie_b; |
| 2775 | |
| 2776 | cookie_a = data->cookies + (name_a - data->funcs); |
| 2777 | cookie_b = data->cookies + (name_b - data->funcs); |
| 2778 | swap(*cookie_a, *cookie_b); |
| 2779 | } |
| 2780 | } |
| 2781 | |
| 2782 | struct modules_array { |
| 2783 | struct module **mods; |
| 2784 | int mods_cnt; |
| 2785 | int mods_cap; |
| 2786 | }; |
| 2787 | |
| 2788 | static int add_module(struct modules_array *arr, struct module *mod) |
| 2789 | { |
| 2790 | struct module **mods; |
| 2791 | |
| 2792 | if (arr->mods_cnt == arr->mods_cap) { |
| 2793 | arr->mods_cap = max(16, arr->mods_cap * 3 / 2); |
| 2794 | mods = krealloc_array(arr->mods, arr->mods_cap, sizeof(*mods), GFP_KERNEL); |
| 2795 | if (!mods) |
| 2796 | return -ENOMEM; |
| 2797 | arr->mods = mods; |
| 2798 | } |
| 2799 | |
| 2800 | arr->mods[arr->mods_cnt] = mod; |
| 2801 | arr->mods_cnt++; |
| 2802 | return 0; |
| 2803 | } |
| 2804 | |
| 2805 | static bool has_module(struct modules_array *arr, struct module *mod) |
| 2806 | { |
| 2807 | int i; |
| 2808 | |
| 2809 | for (i = arr->mods_cnt - 1; i >= 0; i--) { |
| 2810 | if (arr->mods[i] == mod) |
| 2811 | return true; |
| 2812 | } |
| 2813 | return false; |
| 2814 | } |
| 2815 | |
| 2816 | static int get_modules_for_addrs(struct module ***mods, unsigned long *addrs, u32 addrs_cnt) |
| 2817 | { |
| 2818 | struct modules_array arr = {}; |
| 2819 | u32 i, err = 0; |
| 2820 | |
| 2821 | for (i = 0; i < addrs_cnt; i++) { |
| 2822 | bool skip_add = false; |
| 2823 | struct module *mod; |
| 2824 | |
| 2825 | scoped_guard(rcu) { |
| 2826 | mod = __module_address(addrs[i]); |
| 2827 | /* Either no module or it's already stored */ |
| 2828 | if (!mod || has_module(&arr, mod)) { |
| 2829 | skip_add = true; |
| 2830 | break; /* scoped_guard */ |
| 2831 | } |
| 2832 | if (!try_module_get(mod)) |
| 2833 | err = -EINVAL; |
| 2834 | } |
| 2835 | if (skip_add) |
| 2836 | continue; |
| 2837 | if (err) |
| 2838 | break; |
| 2839 | err = add_module(&arr, mod); |
| 2840 | if (err) { |
| 2841 | module_put(mod); |
| 2842 | break; |
| 2843 | } |
| 2844 | } |
| 2845 | |
| 2846 | /* We return either err < 0 in case of error, ... */ |
| 2847 | if (err) { |
| 2848 | kprobe_multi_put_modules(arr.mods, arr.mods_cnt); |
| 2849 | kfree(arr.mods); |
| 2850 | return err; |
| 2851 | } |
| 2852 | |
| 2853 | /* or number of modules found if everything is ok. */ |
| 2854 | *mods = arr.mods; |
| 2855 | return arr.mods_cnt; |
| 2856 | } |
| 2857 | |
| 2858 | static int addrs_check_error_injection_list(unsigned long *addrs, u32 cnt) |
| 2859 | { |
| 2860 | u32 i; |
| 2861 | |
| 2862 | for (i = 0; i < cnt; i++) { |
| 2863 | if (!within_error_injection_list(addrs[i])) |
| 2864 | return -EINVAL; |
| 2865 | } |
| 2866 | return 0; |
| 2867 | } |
| 2868 | |
| 2869 | int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) |
| 2870 | { |
| 2871 | struct bpf_kprobe_multi_link *link = NULL; |
| 2872 | struct bpf_link_primer link_primer; |
| 2873 | void __user *ucookies; |
| 2874 | unsigned long *addrs; |
| 2875 | u32 flags, cnt, size; |
| 2876 | void __user *uaddrs; |
| 2877 | u64 *cookies = NULL; |
| 2878 | void __user *usyms; |
| 2879 | int err; |
| 2880 | |
| 2881 | /* no support for 32bit archs yet */ |
| 2882 | if (sizeof(u64) != sizeof(void *)) |
| 2883 | return -EOPNOTSUPP; |
| 2884 | |
| 2885 | if (attr->link_create.flags) |
| 2886 | return -EINVAL; |
| 2887 | |
| 2888 | if (!is_kprobe_multi(prog)) |
| 2889 | return -EINVAL; |
| 2890 | |
| 2891 | flags = attr->link_create.kprobe_multi.flags; |
| 2892 | if (flags & ~BPF_F_KPROBE_MULTI_RETURN) |
| 2893 | return -EINVAL; |
| 2894 | |
| 2895 | uaddrs = u64_to_user_ptr(attr->link_create.kprobe_multi.addrs); |
| 2896 | usyms = u64_to_user_ptr(attr->link_create.kprobe_multi.syms); |
| 2897 | if (!!uaddrs == !!usyms) |
| 2898 | return -EINVAL; |
| 2899 | |
| 2900 | cnt = attr->link_create.kprobe_multi.cnt; |
| 2901 | if (!cnt) |
| 2902 | return -EINVAL; |
| 2903 | if (cnt > MAX_KPROBE_MULTI_CNT) |
| 2904 | return -E2BIG; |
| 2905 | |
| 2906 | size = cnt * sizeof(*addrs); |
| 2907 | addrs = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL); |
| 2908 | if (!addrs) |
| 2909 | return -ENOMEM; |
| 2910 | |
| 2911 | ucookies = u64_to_user_ptr(attr->link_create.kprobe_multi.cookies); |
| 2912 | if (ucookies) { |
| 2913 | cookies = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL); |
| 2914 | if (!cookies) { |
| 2915 | err = -ENOMEM; |
| 2916 | goto error; |
| 2917 | } |
| 2918 | if (copy_from_user(cookies, ucookies, size)) { |
| 2919 | err = -EFAULT; |
| 2920 | goto error; |
| 2921 | } |
| 2922 | } |
| 2923 | |
| 2924 | if (uaddrs) { |
| 2925 | if (copy_from_user(addrs, uaddrs, size)) { |
| 2926 | err = -EFAULT; |
| 2927 | goto error; |
| 2928 | } |
| 2929 | } else { |
| 2930 | struct multi_symbols_sort data = { |
| 2931 | .cookies = cookies, |
| 2932 | }; |
| 2933 | struct user_syms us; |
| 2934 | |
| 2935 | err = copy_user_syms(&us, usyms, cnt); |
| 2936 | if (err) |
| 2937 | goto error; |
| 2938 | |
| 2939 | if (cookies) |
| 2940 | data.funcs = us.syms; |
| 2941 | |
| 2942 | sort_r(us.syms, cnt, sizeof(*us.syms), symbols_cmp_r, |
| 2943 | symbols_swap_r, &data); |
| 2944 | |
| 2945 | err = ftrace_lookup_symbols(us.syms, cnt, addrs); |
| 2946 | free_user_syms(&us); |
| 2947 | if (err) |
| 2948 | goto error; |
| 2949 | } |
| 2950 | |
| 2951 | if (prog->kprobe_override && addrs_check_error_injection_list(addrs, cnt)) { |
| 2952 | err = -EINVAL; |
| 2953 | goto error; |
| 2954 | } |
| 2955 | |
| 2956 | link = kzalloc(sizeof(*link), GFP_KERNEL); |
| 2957 | if (!link) { |
| 2958 | err = -ENOMEM; |
| 2959 | goto error; |
| 2960 | } |
| 2961 | |
| 2962 | bpf_link_init(&link->link, BPF_LINK_TYPE_KPROBE_MULTI, |
| 2963 | &bpf_kprobe_multi_link_lops, prog); |
| 2964 | |
| 2965 | err = bpf_link_prime(&link->link, &link_primer); |
| 2966 | if (err) |
| 2967 | goto error; |
| 2968 | |
| 2969 | if (!(flags & BPF_F_KPROBE_MULTI_RETURN)) |
| 2970 | link->fp.entry_handler = kprobe_multi_link_handler; |
| 2971 | if ((flags & BPF_F_KPROBE_MULTI_RETURN) || is_kprobe_session(prog)) |
| 2972 | link->fp.exit_handler = kprobe_multi_link_exit_handler; |
| 2973 | if (is_kprobe_session(prog)) |
| 2974 | link->fp.entry_data_size = sizeof(u64); |
| 2975 | |
| 2976 | link->addrs = addrs; |
| 2977 | link->cookies = cookies; |
| 2978 | link->cnt = cnt; |
| 2979 | link->flags = flags; |
| 2980 | |
| 2981 | if (cookies) { |
| 2982 | /* |
| 2983 | * Sorting addresses will trigger sorting cookies as well |
| 2984 | * (check bpf_kprobe_multi_cookie_swap). This way we can |
| 2985 | * find cookie based on the address in bpf_get_attach_cookie |
| 2986 | * helper. |
| 2987 | */ |
| 2988 | sort_r(addrs, cnt, sizeof(*addrs), |
| 2989 | bpf_kprobe_multi_cookie_cmp, |
| 2990 | bpf_kprobe_multi_cookie_swap, |
| 2991 | link); |
| 2992 | } |
| 2993 | |
| 2994 | err = get_modules_for_addrs(&link->mods, addrs, cnt); |
| 2995 | if (err < 0) { |
| 2996 | bpf_link_cleanup(&link_primer); |
| 2997 | return err; |
| 2998 | } |
| 2999 | link->mods_cnt = err; |
| 3000 | |
| 3001 | err = register_fprobe_ips(&link->fp, addrs, cnt); |
| 3002 | if (err) { |
| 3003 | kprobe_multi_put_modules(link->mods, link->mods_cnt); |
| 3004 | bpf_link_cleanup(&link_primer); |
| 3005 | return err; |
| 3006 | } |
| 3007 | |
| 3008 | return bpf_link_settle(&link_primer); |
| 3009 | |
| 3010 | error: |
| 3011 | kfree(link); |
| 3012 | kvfree(addrs); |
| 3013 | kvfree(cookies); |
| 3014 | return err; |
| 3015 | } |
| 3016 | #else /* !CONFIG_FPROBE */ |
| 3017 | int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) |
| 3018 | { |
| 3019 | return -EOPNOTSUPP; |
| 3020 | } |
| 3021 | static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx) |
| 3022 | { |
| 3023 | return 0; |
| 3024 | } |
| 3025 | static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx) |
| 3026 | { |
| 3027 | return 0; |
| 3028 | } |
| 3029 | #endif |
| 3030 | |
| 3031 | #ifdef CONFIG_UPROBES |
| 3032 | struct bpf_uprobe_multi_link; |
| 3033 | |
| 3034 | struct bpf_uprobe { |
| 3035 | struct bpf_uprobe_multi_link *link; |
| 3036 | loff_t offset; |
| 3037 | unsigned long ref_ctr_offset; |
| 3038 | u64 cookie; |
| 3039 | struct uprobe *uprobe; |
| 3040 | struct uprobe_consumer consumer; |
| 3041 | bool session; |
| 3042 | }; |
| 3043 | |
| 3044 | struct bpf_uprobe_multi_link { |
| 3045 | struct path path; |
| 3046 | struct bpf_link link; |
| 3047 | u32 cnt; |
| 3048 | u32 flags; |
| 3049 | struct bpf_uprobe *uprobes; |
| 3050 | struct task_struct *task; |
| 3051 | }; |
| 3052 | |
| 3053 | struct bpf_uprobe_multi_run_ctx { |
| 3054 | struct bpf_session_run_ctx session_ctx; |
| 3055 | unsigned long entry_ip; |
| 3056 | struct bpf_uprobe *uprobe; |
| 3057 | }; |
| 3058 | |
| 3059 | static void bpf_uprobe_unregister(struct bpf_uprobe *uprobes, u32 cnt) |
| 3060 | { |
| 3061 | u32 i; |
| 3062 | |
| 3063 | for (i = 0; i < cnt; i++) |
| 3064 | uprobe_unregister_nosync(uprobes[i].uprobe, &uprobes[i].consumer); |
| 3065 | |
| 3066 | if (cnt) |
| 3067 | uprobe_unregister_sync(); |
| 3068 | } |
| 3069 | |
| 3070 | static void bpf_uprobe_multi_link_release(struct bpf_link *link) |
| 3071 | { |
| 3072 | struct bpf_uprobe_multi_link *umulti_link; |
| 3073 | |
| 3074 | umulti_link = container_of(link, struct bpf_uprobe_multi_link, link); |
| 3075 | bpf_uprobe_unregister(umulti_link->uprobes, umulti_link->cnt); |
| 3076 | if (umulti_link->task) |
| 3077 | put_task_struct(umulti_link->task); |
| 3078 | path_put(&umulti_link->path); |
| 3079 | } |
| 3080 | |
| 3081 | static void bpf_uprobe_multi_link_dealloc(struct bpf_link *link) |
| 3082 | { |
| 3083 | struct bpf_uprobe_multi_link *umulti_link; |
| 3084 | |
| 3085 | umulti_link = container_of(link, struct bpf_uprobe_multi_link, link); |
| 3086 | kvfree(umulti_link->uprobes); |
| 3087 | kfree(umulti_link); |
| 3088 | } |
| 3089 | |
| 3090 | static int bpf_uprobe_multi_link_fill_link_info(const struct bpf_link *link, |
| 3091 | struct bpf_link_info *info) |
| 3092 | { |
| 3093 | u64 __user *uref_ctr_offsets = u64_to_user_ptr(info->uprobe_multi.ref_ctr_offsets); |
| 3094 | u64 __user *ucookies = u64_to_user_ptr(info->uprobe_multi.cookies); |
| 3095 | u64 __user *uoffsets = u64_to_user_ptr(info->uprobe_multi.offsets); |
| 3096 | u64 __user *upath = u64_to_user_ptr(info->uprobe_multi.path); |
| 3097 | u32 upath_size = info->uprobe_multi.path_size; |
| 3098 | struct bpf_uprobe_multi_link *umulti_link; |
| 3099 | u32 ucount = info->uprobe_multi.count; |
| 3100 | int err = 0, i; |
| 3101 | char *p, *buf; |
| 3102 | long left = 0; |
| 3103 | |
| 3104 | if (!upath ^ !upath_size) |
| 3105 | return -EINVAL; |
| 3106 | |
| 3107 | if ((uoffsets || uref_ctr_offsets || ucookies) && !ucount) |
| 3108 | return -EINVAL; |
| 3109 | |
| 3110 | umulti_link = container_of(link, struct bpf_uprobe_multi_link, link); |
| 3111 | info->uprobe_multi.count = umulti_link->cnt; |
| 3112 | info->uprobe_multi.flags = umulti_link->flags; |
| 3113 | info->uprobe_multi.pid = umulti_link->task ? |
| 3114 | task_pid_nr_ns(umulti_link->task, task_active_pid_ns(current)) : 0; |
| 3115 | |
| 3116 | upath_size = upath_size ? min_t(u32, upath_size, PATH_MAX) : PATH_MAX; |
| 3117 | buf = kmalloc(upath_size, GFP_KERNEL); |
| 3118 | if (!buf) |
| 3119 | return -ENOMEM; |
| 3120 | p = d_path(&umulti_link->path, buf, upath_size); |
| 3121 | if (IS_ERR(p)) { |
| 3122 | kfree(buf); |
| 3123 | return PTR_ERR(p); |
| 3124 | } |
| 3125 | upath_size = buf + upath_size - p; |
| 3126 | |
| 3127 | if (upath) |
| 3128 | left = copy_to_user(upath, p, upath_size); |
| 3129 | kfree(buf); |
| 3130 | if (left) |
| 3131 | return -EFAULT; |
| 3132 | info->uprobe_multi.path_size = upath_size; |
| 3133 | |
| 3134 | if (!uoffsets && !ucookies && !uref_ctr_offsets) |
| 3135 | return 0; |
| 3136 | |
| 3137 | if (ucount < umulti_link->cnt) |
| 3138 | err = -ENOSPC; |
| 3139 | else |
| 3140 | ucount = umulti_link->cnt; |
| 3141 | |
| 3142 | for (i = 0; i < ucount; i++) { |
| 3143 | if (uoffsets && |
| 3144 | put_user(umulti_link->uprobes[i].offset, uoffsets + i)) |
| 3145 | return -EFAULT; |
| 3146 | if (uref_ctr_offsets && |
| 3147 | put_user(umulti_link->uprobes[i].ref_ctr_offset, uref_ctr_offsets + i)) |
| 3148 | return -EFAULT; |
| 3149 | if (ucookies && |
| 3150 | put_user(umulti_link->uprobes[i].cookie, ucookies + i)) |
| 3151 | return -EFAULT; |
| 3152 | } |
| 3153 | |
| 3154 | return err; |
| 3155 | } |
| 3156 | |
| 3157 | static const struct bpf_link_ops bpf_uprobe_multi_link_lops = { |
| 3158 | .release = bpf_uprobe_multi_link_release, |
| 3159 | .dealloc_deferred = bpf_uprobe_multi_link_dealloc, |
| 3160 | .fill_link_info = bpf_uprobe_multi_link_fill_link_info, |
| 3161 | }; |
| 3162 | |
| 3163 | static int uprobe_prog_run(struct bpf_uprobe *uprobe, |
| 3164 | unsigned long entry_ip, |
| 3165 | struct pt_regs *regs, |
| 3166 | bool is_return, void *data) |
| 3167 | { |
| 3168 | struct bpf_uprobe_multi_link *link = uprobe->link; |
| 3169 | struct bpf_uprobe_multi_run_ctx run_ctx = { |
| 3170 | .session_ctx = { |
| 3171 | .is_return = is_return, |
| 3172 | .data = data, |
| 3173 | }, |
| 3174 | .entry_ip = entry_ip, |
| 3175 | .uprobe = uprobe, |
| 3176 | }; |
| 3177 | struct bpf_prog *prog = link->link.prog; |
| 3178 | bool sleepable = prog->sleepable; |
| 3179 | struct bpf_run_ctx *old_run_ctx; |
| 3180 | int err; |
| 3181 | |
| 3182 | if (link->task && !same_thread_group(current, link->task)) |
| 3183 | return 0; |
| 3184 | |
| 3185 | if (sleepable) |
| 3186 | rcu_read_lock_trace(); |
| 3187 | else |
| 3188 | rcu_read_lock(); |
| 3189 | |
| 3190 | migrate_disable(); |
| 3191 | |
| 3192 | old_run_ctx = bpf_set_run_ctx(&run_ctx.session_ctx.run_ctx); |
| 3193 | err = bpf_prog_run(link->link.prog, regs); |
| 3194 | bpf_reset_run_ctx(old_run_ctx); |
| 3195 | |
| 3196 | migrate_enable(); |
| 3197 | |
| 3198 | if (sleepable) |
| 3199 | rcu_read_unlock_trace(); |
| 3200 | else |
| 3201 | rcu_read_unlock(); |
| 3202 | return err; |
| 3203 | } |
| 3204 | |
| 3205 | static bool |
| 3206 | uprobe_multi_link_filter(struct uprobe_consumer *con, struct mm_struct *mm) |
| 3207 | { |
| 3208 | struct bpf_uprobe *uprobe; |
| 3209 | |
| 3210 | uprobe = container_of(con, struct bpf_uprobe, consumer); |
| 3211 | return uprobe->link->task->mm == mm; |
| 3212 | } |
| 3213 | |
| 3214 | static int |
| 3215 | uprobe_multi_link_handler(struct uprobe_consumer *con, struct pt_regs *regs, |
| 3216 | __u64 *data) |
| 3217 | { |
| 3218 | struct bpf_uprobe *uprobe; |
| 3219 | int ret; |
| 3220 | |
| 3221 | uprobe = container_of(con, struct bpf_uprobe, consumer); |
| 3222 | ret = uprobe_prog_run(uprobe, instruction_pointer(regs), regs, false, data); |
| 3223 | if (uprobe->session) |
| 3224 | return ret ? UPROBE_HANDLER_IGNORE : 0; |
| 3225 | return 0; |
| 3226 | } |
| 3227 | |
| 3228 | static int |
| 3229 | uprobe_multi_link_ret_handler(struct uprobe_consumer *con, unsigned long func, struct pt_regs *regs, |
| 3230 | __u64 *data) |
| 3231 | { |
| 3232 | struct bpf_uprobe *uprobe; |
| 3233 | |
| 3234 | uprobe = container_of(con, struct bpf_uprobe, consumer); |
| 3235 | uprobe_prog_run(uprobe, func, regs, true, data); |
| 3236 | return 0; |
| 3237 | } |
| 3238 | |
| 3239 | static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx) |
| 3240 | { |
| 3241 | struct bpf_uprobe_multi_run_ctx *run_ctx; |
| 3242 | |
| 3243 | run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx, |
| 3244 | session_ctx.run_ctx); |
| 3245 | return run_ctx->entry_ip; |
| 3246 | } |
| 3247 | |
| 3248 | static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx) |
| 3249 | { |
| 3250 | struct bpf_uprobe_multi_run_ctx *run_ctx; |
| 3251 | |
| 3252 | run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx, |
| 3253 | session_ctx.run_ctx); |
| 3254 | return run_ctx->uprobe->cookie; |
| 3255 | } |
| 3256 | |
| 3257 | int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) |
| 3258 | { |
| 3259 | struct bpf_uprobe_multi_link *link = NULL; |
| 3260 | unsigned long __user *uref_ctr_offsets; |
| 3261 | struct bpf_link_primer link_primer; |
| 3262 | struct bpf_uprobe *uprobes = NULL; |
| 3263 | struct task_struct *task = NULL; |
| 3264 | unsigned long __user *uoffsets; |
| 3265 | u64 __user *ucookies; |
| 3266 | void __user *upath; |
| 3267 | u32 flags, cnt, i; |
| 3268 | struct path path; |
| 3269 | char *name; |
| 3270 | pid_t pid; |
| 3271 | int err; |
| 3272 | |
| 3273 | /* no support for 32bit archs yet */ |
| 3274 | if (sizeof(u64) != sizeof(void *)) |
| 3275 | return -EOPNOTSUPP; |
| 3276 | |
| 3277 | if (attr->link_create.flags) |
| 3278 | return -EINVAL; |
| 3279 | |
| 3280 | if (!is_uprobe_multi(prog)) |
| 3281 | return -EINVAL; |
| 3282 | |
| 3283 | flags = attr->link_create.uprobe_multi.flags; |
| 3284 | if (flags & ~BPF_F_UPROBE_MULTI_RETURN) |
| 3285 | return -EINVAL; |
| 3286 | |
| 3287 | /* |
| 3288 | * path, offsets and cnt are mandatory, |
| 3289 | * ref_ctr_offsets and cookies are optional |
| 3290 | */ |
| 3291 | upath = u64_to_user_ptr(attr->link_create.uprobe_multi.path); |
| 3292 | uoffsets = u64_to_user_ptr(attr->link_create.uprobe_multi.offsets); |
| 3293 | cnt = attr->link_create.uprobe_multi.cnt; |
| 3294 | pid = attr->link_create.uprobe_multi.pid; |
| 3295 | |
| 3296 | if (!upath || !uoffsets || !cnt || pid < 0) |
| 3297 | return -EINVAL; |
| 3298 | if (cnt > MAX_UPROBE_MULTI_CNT) |
| 3299 | return -E2BIG; |
| 3300 | |
| 3301 | uref_ctr_offsets = u64_to_user_ptr(attr->link_create.uprobe_multi.ref_ctr_offsets); |
| 3302 | ucookies = u64_to_user_ptr(attr->link_create.uprobe_multi.cookies); |
| 3303 | |
| 3304 | name = strndup_user(upath, PATH_MAX); |
| 3305 | if (IS_ERR(name)) { |
| 3306 | err = PTR_ERR(name); |
| 3307 | return err; |
| 3308 | } |
| 3309 | |
| 3310 | err = kern_path(name, LOOKUP_FOLLOW, &path); |
| 3311 | kfree(name); |
| 3312 | if (err) |
| 3313 | return err; |
| 3314 | |
| 3315 | if (!d_is_reg(path.dentry)) { |
| 3316 | err = -EBADF; |
| 3317 | goto error_path_put; |
| 3318 | } |
| 3319 | |
| 3320 | if (pid) { |
| 3321 | rcu_read_lock(); |
| 3322 | task = get_pid_task(find_vpid(pid), PIDTYPE_TGID); |
| 3323 | rcu_read_unlock(); |
| 3324 | if (!task) { |
| 3325 | err = -ESRCH; |
| 3326 | goto error_path_put; |
| 3327 | } |
| 3328 | } |
| 3329 | |
| 3330 | err = -ENOMEM; |
| 3331 | |
| 3332 | link = kzalloc(sizeof(*link), GFP_KERNEL); |
| 3333 | uprobes = kvcalloc(cnt, sizeof(*uprobes), GFP_KERNEL); |
| 3334 | |
| 3335 | if (!uprobes || !link) |
| 3336 | goto error_free; |
| 3337 | |
| 3338 | for (i = 0; i < cnt; i++) { |
| 3339 | if (__get_user(uprobes[i].offset, uoffsets + i)) { |
| 3340 | err = -EFAULT; |
| 3341 | goto error_free; |
| 3342 | } |
| 3343 | if (uprobes[i].offset < 0) { |
| 3344 | err = -EINVAL; |
| 3345 | goto error_free; |
| 3346 | } |
| 3347 | if (uref_ctr_offsets && __get_user(uprobes[i].ref_ctr_offset, uref_ctr_offsets + i)) { |
| 3348 | err = -EFAULT; |
| 3349 | goto error_free; |
| 3350 | } |
| 3351 | if (ucookies && __get_user(uprobes[i].cookie, ucookies + i)) { |
| 3352 | err = -EFAULT; |
| 3353 | goto error_free; |
| 3354 | } |
| 3355 | |
| 3356 | uprobes[i].link = link; |
| 3357 | |
| 3358 | if (!(flags & BPF_F_UPROBE_MULTI_RETURN)) |
| 3359 | uprobes[i].consumer.handler = uprobe_multi_link_handler; |
| 3360 | if (flags & BPF_F_UPROBE_MULTI_RETURN || is_uprobe_session(prog)) |
| 3361 | uprobes[i].consumer.ret_handler = uprobe_multi_link_ret_handler; |
| 3362 | if (is_uprobe_session(prog)) |
| 3363 | uprobes[i].session = true; |
| 3364 | if (pid) |
| 3365 | uprobes[i].consumer.filter = uprobe_multi_link_filter; |
| 3366 | } |
| 3367 | |
| 3368 | link->cnt = cnt; |
| 3369 | link->uprobes = uprobes; |
| 3370 | link->path = path; |
| 3371 | link->task = task; |
| 3372 | link->flags = flags; |
| 3373 | |
| 3374 | bpf_link_init(&link->link, BPF_LINK_TYPE_UPROBE_MULTI, |
| 3375 | &bpf_uprobe_multi_link_lops, prog); |
| 3376 | |
| 3377 | for (i = 0; i < cnt; i++) { |
| 3378 | uprobes[i].uprobe = uprobe_register(d_real_inode(link->path.dentry), |
| 3379 | uprobes[i].offset, |
| 3380 | uprobes[i].ref_ctr_offset, |
| 3381 | &uprobes[i].consumer); |
| 3382 | if (IS_ERR(uprobes[i].uprobe)) { |
| 3383 | err = PTR_ERR(uprobes[i].uprobe); |
| 3384 | link->cnt = i; |
| 3385 | goto error_unregister; |
| 3386 | } |
| 3387 | } |
| 3388 | |
| 3389 | err = bpf_link_prime(&link->link, &link_primer); |
| 3390 | if (err) |
| 3391 | goto error_unregister; |
| 3392 | |
| 3393 | return bpf_link_settle(&link_primer); |
| 3394 | |
| 3395 | error_unregister: |
| 3396 | bpf_uprobe_unregister(uprobes, link->cnt); |
| 3397 | |
| 3398 | error_free: |
| 3399 | kvfree(uprobes); |
| 3400 | kfree(link); |
| 3401 | if (task) |
| 3402 | put_task_struct(task); |
| 3403 | error_path_put: |
| 3404 | path_put(&path); |
| 3405 | return err; |
| 3406 | } |
| 3407 | #else /* !CONFIG_UPROBES */ |
| 3408 | int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) |
| 3409 | { |
| 3410 | return -EOPNOTSUPP; |
| 3411 | } |
| 3412 | static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx) |
| 3413 | { |
| 3414 | return 0; |
| 3415 | } |
| 3416 | static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx) |
| 3417 | { |
| 3418 | return 0; |
| 3419 | } |
| 3420 | #endif /* CONFIG_UPROBES */ |
| 3421 | |
| 3422 | __bpf_kfunc_start_defs(); |
| 3423 | |
| 3424 | __bpf_kfunc bool bpf_session_is_return(void) |
| 3425 | { |
| 3426 | struct bpf_session_run_ctx *session_ctx; |
| 3427 | |
| 3428 | session_ctx = container_of(current->bpf_ctx, struct bpf_session_run_ctx, run_ctx); |
| 3429 | return session_ctx->is_return; |
| 3430 | } |
| 3431 | |
| 3432 | __bpf_kfunc __u64 *bpf_session_cookie(void) |
| 3433 | { |
| 3434 | struct bpf_session_run_ctx *session_ctx; |
| 3435 | |
| 3436 | session_ctx = container_of(current->bpf_ctx, struct bpf_session_run_ctx, run_ctx); |
| 3437 | return session_ctx->data; |
| 3438 | } |
| 3439 | |
| 3440 | __bpf_kfunc_end_defs(); |
| 3441 | |
| 3442 | BTF_KFUNCS_START(kprobe_multi_kfunc_set_ids) |
| 3443 | BTF_ID_FLAGS(func, bpf_session_is_return) |
| 3444 | BTF_ID_FLAGS(func, bpf_session_cookie) |
| 3445 | BTF_KFUNCS_END(kprobe_multi_kfunc_set_ids) |
| 3446 | |
| 3447 | static int bpf_kprobe_multi_filter(const struct bpf_prog *prog, u32 kfunc_id) |
| 3448 | { |
| 3449 | if (!btf_id_set8_contains(&kprobe_multi_kfunc_set_ids, kfunc_id)) |
| 3450 | return 0; |
| 3451 | |
| 3452 | if (!is_kprobe_session(prog) && !is_uprobe_session(prog)) |
| 3453 | return -EACCES; |
| 3454 | |
| 3455 | return 0; |
| 3456 | } |
| 3457 | |
| 3458 | static const struct btf_kfunc_id_set bpf_kprobe_multi_kfunc_set = { |
| 3459 | .owner = THIS_MODULE, |
| 3460 | .set = &kprobe_multi_kfunc_set_ids, |
| 3461 | .filter = bpf_kprobe_multi_filter, |
| 3462 | }; |
| 3463 | |
| 3464 | static int __init bpf_kprobe_multi_kfuncs_init(void) |
| 3465 | { |
| 3466 | return register_btf_kfunc_id_set(BPF_PROG_TYPE_KPROBE, &bpf_kprobe_multi_kfunc_set); |
| 3467 | } |
| 3468 | |
| 3469 | late_initcall(bpf_kprobe_multi_kfuncs_init); |
| 3470 | |
| 3471 | typedef int (*copy_fn_t)(void *dst, const void *src, u32 size, struct task_struct *tsk); |
| 3472 | |
| 3473 | /* |
| 3474 | * The __always_inline is to make sure the compiler doesn't |
| 3475 | * generate indirect calls into callbacks, which is expensive, |
| 3476 | * on some kernel configurations. This allows compiler to put |
| 3477 | * direct calls into all the specific callback implementations |
| 3478 | * (copy_user_data_sleepable, copy_user_data_nofault, and so on) |
| 3479 | */ |
| 3480 | static __always_inline int __bpf_dynptr_copy_str(struct bpf_dynptr *dptr, u32 doff, u32 size, |
| 3481 | const void *unsafe_src, |
| 3482 | copy_fn_t str_copy_fn, |
| 3483 | struct task_struct *tsk) |
| 3484 | { |
| 3485 | struct bpf_dynptr_kern *dst; |
| 3486 | u32 chunk_sz, off; |
| 3487 | void *dst_slice; |
| 3488 | int cnt, err; |
| 3489 | char buf[256]; |
| 3490 | |
| 3491 | dst_slice = bpf_dynptr_slice_rdwr(dptr, doff, NULL, size); |
| 3492 | if (likely(dst_slice)) |
| 3493 | return str_copy_fn(dst_slice, unsafe_src, size, tsk); |
| 3494 | |
| 3495 | dst = (struct bpf_dynptr_kern *)dptr; |
| 3496 | if (bpf_dynptr_check_off_len(dst, doff, size)) |
| 3497 | return -E2BIG; |
| 3498 | |
| 3499 | for (off = 0; off < size; off += chunk_sz - 1) { |
| 3500 | chunk_sz = min_t(u32, sizeof(buf), size - off); |
| 3501 | /* Expect str_copy_fn to return count of copied bytes, including |
| 3502 | * zero terminator. Next iteration increment off by chunk_sz - 1 to |
| 3503 | * overwrite NUL. |
| 3504 | */ |
| 3505 | cnt = str_copy_fn(buf, unsafe_src + off, chunk_sz, tsk); |
| 3506 | if (cnt < 0) |
| 3507 | return cnt; |
| 3508 | err = __bpf_dynptr_write(dst, doff + off, buf, cnt, 0); |
| 3509 | if (err) |
| 3510 | return err; |
| 3511 | if (cnt < chunk_sz || chunk_sz == 1) /* we are done */ |
| 3512 | return off + cnt; |
| 3513 | } |
| 3514 | return off; |
| 3515 | } |
| 3516 | |
| 3517 | static __always_inline int __bpf_dynptr_copy(const struct bpf_dynptr *dptr, u32 doff, |
| 3518 | u32 size, const void *unsafe_src, |
| 3519 | copy_fn_t copy_fn, struct task_struct *tsk) |
| 3520 | { |
| 3521 | struct bpf_dynptr_kern *dst; |
| 3522 | void *dst_slice; |
| 3523 | char buf[256]; |
| 3524 | u32 off, chunk_sz; |
| 3525 | int err; |
| 3526 | |
| 3527 | dst_slice = bpf_dynptr_slice_rdwr(dptr, doff, NULL, size); |
| 3528 | if (likely(dst_slice)) |
| 3529 | return copy_fn(dst_slice, unsafe_src, size, tsk); |
| 3530 | |
| 3531 | dst = (struct bpf_dynptr_kern *)dptr; |
| 3532 | if (bpf_dynptr_check_off_len(dst, doff, size)) |
| 3533 | return -E2BIG; |
| 3534 | |
| 3535 | for (off = 0; off < size; off += chunk_sz) { |
| 3536 | chunk_sz = min_t(u32, sizeof(buf), size - off); |
| 3537 | err = copy_fn(buf, unsafe_src + off, chunk_sz, tsk); |
| 3538 | if (err) |
| 3539 | return err; |
| 3540 | err = __bpf_dynptr_write(dst, doff + off, buf, chunk_sz, 0); |
| 3541 | if (err) |
| 3542 | return err; |
| 3543 | } |
| 3544 | return 0; |
| 3545 | } |
| 3546 | |
| 3547 | static __always_inline int copy_user_data_nofault(void *dst, const void *unsafe_src, |
| 3548 | u32 size, struct task_struct *tsk) |
| 3549 | { |
| 3550 | return copy_from_user_nofault(dst, (const void __user *)unsafe_src, size); |
| 3551 | } |
| 3552 | |
| 3553 | static __always_inline int copy_user_data_sleepable(void *dst, const void *unsafe_src, |
| 3554 | u32 size, struct task_struct *tsk) |
| 3555 | { |
| 3556 | int ret; |
| 3557 | |
| 3558 | if (!tsk) { /* Read from the current task */ |
| 3559 | ret = copy_from_user(dst, (const void __user *)unsafe_src, size); |
| 3560 | if (ret) |
| 3561 | return -EFAULT; |
| 3562 | return 0; |
| 3563 | } |
| 3564 | |
| 3565 | ret = access_process_vm(tsk, (unsigned long)unsafe_src, dst, size, 0); |
| 3566 | if (ret != size) |
| 3567 | return -EFAULT; |
| 3568 | return 0; |
| 3569 | } |
| 3570 | |
| 3571 | static __always_inline int copy_kernel_data_nofault(void *dst, const void *unsafe_src, |
| 3572 | u32 size, struct task_struct *tsk) |
| 3573 | { |
| 3574 | return copy_from_kernel_nofault(dst, unsafe_src, size); |
| 3575 | } |
| 3576 | |
| 3577 | static __always_inline int copy_user_str_nofault(void *dst, const void *unsafe_src, |
| 3578 | u32 size, struct task_struct *tsk) |
| 3579 | { |
| 3580 | return strncpy_from_user_nofault(dst, (const void __user *)unsafe_src, size); |
| 3581 | } |
| 3582 | |
| 3583 | static __always_inline int copy_user_str_sleepable(void *dst, const void *unsafe_src, |
| 3584 | u32 size, struct task_struct *tsk) |
| 3585 | { |
| 3586 | int ret; |
| 3587 | |
| 3588 | if (unlikely(size == 0)) |
| 3589 | return 0; |
| 3590 | |
| 3591 | if (tsk) { |
| 3592 | ret = copy_remote_vm_str(tsk, (unsigned long)unsafe_src, dst, size, 0); |
| 3593 | } else { |
| 3594 | ret = strncpy_from_user(dst, (const void __user *)unsafe_src, size - 1); |
| 3595 | /* strncpy_from_user does not guarantee NUL termination */ |
| 3596 | if (ret >= 0) |
| 3597 | ((char *)dst)[ret] = '\0'; |
| 3598 | } |
| 3599 | |
| 3600 | if (ret < 0) |
| 3601 | return ret; |
| 3602 | return ret + 1; |
| 3603 | } |
| 3604 | |
| 3605 | static __always_inline int copy_kernel_str_nofault(void *dst, const void *unsafe_src, |
| 3606 | u32 size, struct task_struct *tsk) |
| 3607 | { |
| 3608 | return strncpy_from_kernel_nofault(dst, unsafe_src, size); |
| 3609 | } |
| 3610 | |
| 3611 | __bpf_kfunc_start_defs(); |
| 3612 | |
| 3613 | __bpf_kfunc int bpf_send_signal_task(struct task_struct *task, int sig, enum pid_type type, |
| 3614 | u64 value) |
| 3615 | { |
| 3616 | if (type != PIDTYPE_PID && type != PIDTYPE_TGID) |
| 3617 | return -EINVAL; |
| 3618 | |
| 3619 | return bpf_send_signal_common(sig, type, task, value); |
| 3620 | } |
| 3621 | |
| 3622 | __bpf_kfunc int bpf_probe_read_user_dynptr(struct bpf_dynptr *dptr, u32 off, |
| 3623 | u32 size, const void __user *unsafe_ptr__ign) |
| 3624 | { |
| 3625 | return __bpf_dynptr_copy(dptr, off, size, (const void *)unsafe_ptr__ign, |
| 3626 | copy_user_data_nofault, NULL); |
| 3627 | } |
| 3628 | |
| 3629 | __bpf_kfunc int bpf_probe_read_kernel_dynptr(struct bpf_dynptr *dptr, u32 off, |
| 3630 | u32 size, const void *unsafe_ptr__ign) |
| 3631 | { |
| 3632 | return __bpf_dynptr_copy(dptr, off, size, unsafe_ptr__ign, |
| 3633 | copy_kernel_data_nofault, NULL); |
| 3634 | } |
| 3635 | |
| 3636 | __bpf_kfunc int bpf_probe_read_user_str_dynptr(struct bpf_dynptr *dptr, u32 off, |
| 3637 | u32 size, const void __user *unsafe_ptr__ign) |
| 3638 | { |
| 3639 | return __bpf_dynptr_copy_str(dptr, off, size, (const void *)unsafe_ptr__ign, |
| 3640 | copy_user_str_nofault, NULL); |
| 3641 | } |
| 3642 | |
| 3643 | __bpf_kfunc int bpf_probe_read_kernel_str_dynptr(struct bpf_dynptr *dptr, u32 off, |
| 3644 | u32 size, const void *unsafe_ptr__ign) |
| 3645 | { |
| 3646 | return __bpf_dynptr_copy_str(dptr, off, size, unsafe_ptr__ign, |
| 3647 | copy_kernel_str_nofault, NULL); |
| 3648 | } |
| 3649 | |
| 3650 | __bpf_kfunc int bpf_copy_from_user_dynptr(struct bpf_dynptr *dptr, u32 off, |
| 3651 | u32 size, const void __user *unsafe_ptr__ign) |
| 3652 | { |
| 3653 | return __bpf_dynptr_copy(dptr, off, size, (const void *)unsafe_ptr__ign, |
| 3654 | copy_user_data_sleepable, NULL); |
| 3655 | } |
| 3656 | |
| 3657 | __bpf_kfunc int bpf_copy_from_user_str_dynptr(struct bpf_dynptr *dptr, u32 off, |
| 3658 | u32 size, const void __user *unsafe_ptr__ign) |
| 3659 | { |
| 3660 | return __bpf_dynptr_copy_str(dptr, off, size, (const void *)unsafe_ptr__ign, |
| 3661 | copy_user_str_sleepable, NULL); |
| 3662 | } |
| 3663 | |
| 3664 | __bpf_kfunc int bpf_copy_from_user_task_dynptr(struct bpf_dynptr *dptr, u32 off, |
| 3665 | u32 size, const void __user *unsafe_ptr__ign, |
| 3666 | struct task_struct *tsk) |
| 3667 | { |
| 3668 | return __bpf_dynptr_copy(dptr, off, size, (const void *)unsafe_ptr__ign, |
| 3669 | copy_user_data_sleepable, tsk); |
| 3670 | } |
| 3671 | |
| 3672 | __bpf_kfunc int bpf_copy_from_user_task_str_dynptr(struct bpf_dynptr *dptr, u32 off, |
| 3673 | u32 size, const void __user *unsafe_ptr__ign, |
| 3674 | struct task_struct *tsk) |
| 3675 | { |
| 3676 | return __bpf_dynptr_copy_str(dptr, off, size, (const void *)unsafe_ptr__ign, |
| 3677 | copy_user_str_sleepable, tsk); |
| 3678 | } |
| 3679 | |
| 3680 | __bpf_kfunc_end_defs(); |