xref: /openbmc/linux/kernel/trace/bpf_trace.c (revision b9dd2add)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2011-2015 PLUMgrid, http://plumgrid.com
3  * Copyright (c) 2016 Facebook
4  */
5 #include <linux/kernel.h>
6 #include <linux/types.h>
7 #include <linux/slab.h>
8 #include <linux/bpf.h>
9 #include <linux/bpf_perf_event.h>
10 #include <linux/btf.h>
11 #include <linux/filter.h>
12 #include <linux/uaccess.h>
13 #include <linux/ctype.h>
14 #include <linux/kprobes.h>
15 #include <linux/spinlock.h>
16 #include <linux/syscalls.h>
17 #include <linux/error-injection.h>
18 #include <linux/btf_ids.h>
19 #include <linux/bpf_lsm.h>
20 
21 #include <net/bpf_sk_storage.h>
22 
23 #include <uapi/linux/bpf.h>
24 #include <uapi/linux/btf.h>
25 
26 #include <asm/tlb.h>
27 
28 #include "trace_probe.h"
29 #include "trace.h"
30 
31 #define CREATE_TRACE_POINTS
32 #include "bpf_trace.h"
33 
34 #define bpf_event_rcu_dereference(p)					\
35 	rcu_dereference_protected(p, lockdep_is_held(&bpf_event_mutex))
36 
37 #ifdef CONFIG_MODULES
38 struct bpf_trace_module {
39 	struct module *module;
40 	struct list_head list;
41 };
42 
43 static LIST_HEAD(bpf_trace_modules);
44 static DEFINE_MUTEX(bpf_module_mutex);
45 
46 static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name)
47 {
48 	struct bpf_raw_event_map *btp, *ret = NULL;
49 	struct bpf_trace_module *btm;
50 	unsigned int i;
51 
52 	mutex_lock(&bpf_module_mutex);
53 	list_for_each_entry(btm, &bpf_trace_modules, list) {
54 		for (i = 0; i < btm->module->num_bpf_raw_events; ++i) {
55 			btp = &btm->module->bpf_raw_events[i];
56 			if (!strcmp(btp->tp->name, name)) {
57 				if (try_module_get(btm->module))
58 					ret = btp;
59 				goto out;
60 			}
61 		}
62 	}
63 out:
64 	mutex_unlock(&bpf_module_mutex);
65 	return ret;
66 }
67 #else
68 static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name)
69 {
70 	return NULL;
71 }
72 #endif /* CONFIG_MODULES */
73 
74 u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
75 u64 bpf_get_stack(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
76 
77 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size,
78 				  u64 flags, const struct btf **btf,
79 				  s32 *btf_id);
80 
81 /**
82  * trace_call_bpf - invoke BPF program
83  * @call: tracepoint event
84  * @ctx: opaque context pointer
85  *
86  * kprobe handlers execute BPF programs via this helper.
87  * Can be used from static tracepoints in the future.
88  *
89  * Return: BPF programs always return an integer which is interpreted by
90  * kprobe handler as:
91  * 0 - return from kprobe (event is filtered out)
92  * 1 - store kprobe event into ring buffer
93  * Other values are reserved and currently alias to 1
94  */
95 unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx)
96 {
97 	unsigned int ret;
98 
99 	if (in_nmi()) /* not supported yet */
100 		return 1;
101 
102 	cant_sleep();
103 
104 	if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) {
105 		/*
106 		 * since some bpf program is already running on this cpu,
107 		 * don't call into another bpf program (same or different)
108 		 * and don't send kprobe event into ring-buffer,
109 		 * so return zero here
110 		 */
111 		ret = 0;
112 		goto out;
113 	}
114 
115 	/*
116 	 * Instead of moving rcu_read_lock/rcu_dereference/rcu_read_unlock
117 	 * to all call sites, we did a bpf_prog_array_valid() there to check
118 	 * whether call->prog_array is empty or not, which is
119 	 * a heuristic to speed up execution.
120 	 *
121 	 * If bpf_prog_array_valid() fetched prog_array was
122 	 * non-NULL, we go into trace_call_bpf() and do the actual
123 	 * proper rcu_dereference() under RCU lock.
124 	 * If it turns out that prog_array is NULL then, we bail out.
125 	 * For the opposite, if the bpf_prog_array_valid() fetched pointer
126 	 * was NULL, you'll skip the prog_array with the risk of missing
127 	 * out of events when it was updated in between this and the
128 	 * rcu_dereference() which is accepted risk.
129 	 */
130 	ret = BPF_PROG_RUN_ARRAY_CHECK(call->prog_array, ctx, BPF_PROG_RUN);
131 
132  out:
133 	__this_cpu_dec(bpf_prog_active);
134 
135 	return ret;
136 }
137 
138 #ifdef CONFIG_BPF_KPROBE_OVERRIDE
139 BPF_CALL_2(bpf_override_return, struct pt_regs *, regs, unsigned long, rc)
140 {
141 	regs_set_return_value(regs, rc);
142 	override_function_with_return(regs);
143 	return 0;
144 }
145 
146 static const struct bpf_func_proto bpf_override_return_proto = {
147 	.func		= bpf_override_return,
148 	.gpl_only	= true,
149 	.ret_type	= RET_INTEGER,
150 	.arg1_type	= ARG_PTR_TO_CTX,
151 	.arg2_type	= ARG_ANYTHING,
152 };
153 #endif
154 
155 static __always_inline int
156 bpf_probe_read_user_common(void *dst, u32 size, const void __user *unsafe_ptr)
157 {
158 	int ret;
159 
160 	ret = copy_from_user_nofault(dst, unsafe_ptr, size);
161 	if (unlikely(ret < 0))
162 		memset(dst, 0, size);
163 	return ret;
164 }
165 
166 BPF_CALL_3(bpf_probe_read_user, void *, dst, u32, size,
167 	   const void __user *, unsafe_ptr)
168 {
169 	return bpf_probe_read_user_common(dst, size, unsafe_ptr);
170 }
171 
172 const struct bpf_func_proto bpf_probe_read_user_proto = {
173 	.func		= bpf_probe_read_user,
174 	.gpl_only	= true,
175 	.ret_type	= RET_INTEGER,
176 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
177 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
178 	.arg3_type	= ARG_ANYTHING,
179 };
180 
181 static __always_inline int
182 bpf_probe_read_user_str_common(void *dst, u32 size,
183 			       const void __user *unsafe_ptr)
184 {
185 	int ret;
186 
187 	/*
188 	 * NB: We rely on strncpy_from_user() not copying junk past the NUL
189 	 * terminator into `dst`.
190 	 *
191 	 * strncpy_from_user() does long-sized strides in the fast path. If the
192 	 * strncpy does not mask out the bytes after the NUL in `unsafe_ptr`,
193 	 * then there could be junk after the NUL in `dst`. If user takes `dst`
194 	 * and keys a hash map with it, then semantically identical strings can
195 	 * occupy multiple entries in the map.
196 	 */
197 	ret = strncpy_from_user_nofault(dst, unsafe_ptr, size);
198 	if (unlikely(ret < 0))
199 		memset(dst, 0, size);
200 	return ret;
201 }
202 
203 BPF_CALL_3(bpf_probe_read_user_str, void *, dst, u32, size,
204 	   const void __user *, unsafe_ptr)
205 {
206 	return bpf_probe_read_user_str_common(dst, size, unsafe_ptr);
207 }
208 
209 const struct bpf_func_proto bpf_probe_read_user_str_proto = {
210 	.func		= bpf_probe_read_user_str,
211 	.gpl_only	= true,
212 	.ret_type	= RET_INTEGER,
213 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
214 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
215 	.arg3_type	= ARG_ANYTHING,
216 };
217 
218 static __always_inline int
219 bpf_probe_read_kernel_common(void *dst, u32 size, const void *unsafe_ptr)
220 {
221 	int ret = security_locked_down(LOCKDOWN_BPF_READ);
222 
223 	if (unlikely(ret < 0))
224 		goto fail;
225 	ret = copy_from_kernel_nofault(dst, unsafe_ptr, size);
226 	if (unlikely(ret < 0))
227 		goto fail;
228 	return ret;
229 fail:
230 	memset(dst, 0, size);
231 	return ret;
232 }
233 
234 BPF_CALL_3(bpf_probe_read_kernel, void *, dst, u32, size,
235 	   const void *, unsafe_ptr)
236 {
237 	return bpf_probe_read_kernel_common(dst, size, unsafe_ptr);
238 }
239 
240 const struct bpf_func_proto bpf_probe_read_kernel_proto = {
241 	.func		= bpf_probe_read_kernel,
242 	.gpl_only	= true,
243 	.ret_type	= RET_INTEGER,
244 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
245 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
246 	.arg3_type	= ARG_ANYTHING,
247 };
248 
249 static __always_inline int
250 bpf_probe_read_kernel_str_common(void *dst, u32 size, const void *unsafe_ptr)
251 {
252 	int ret = security_locked_down(LOCKDOWN_BPF_READ);
253 
254 	if (unlikely(ret < 0))
255 		goto fail;
256 
257 	/*
258 	 * The strncpy_from_kernel_nofault() call will likely not fill the
259 	 * entire buffer, but that's okay in this circumstance as we're probing
260 	 * arbitrary memory anyway similar to bpf_probe_read_*() and might
261 	 * as well probe the stack. Thus, memory is explicitly cleared
262 	 * only in error case, so that improper users ignoring return
263 	 * code altogether don't copy garbage; otherwise length of string
264 	 * is returned that can be used for bpf_perf_event_output() et al.
265 	 */
266 	ret = strncpy_from_kernel_nofault(dst, unsafe_ptr, size);
267 	if (unlikely(ret < 0))
268 		goto fail;
269 
270 	return ret;
271 fail:
272 	memset(dst, 0, size);
273 	return ret;
274 }
275 
276 BPF_CALL_3(bpf_probe_read_kernel_str, void *, dst, u32, size,
277 	   const void *, unsafe_ptr)
278 {
279 	return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr);
280 }
281 
282 const struct bpf_func_proto bpf_probe_read_kernel_str_proto = {
283 	.func		= bpf_probe_read_kernel_str,
284 	.gpl_only	= true,
285 	.ret_type	= RET_INTEGER,
286 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
287 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
288 	.arg3_type	= ARG_ANYTHING,
289 };
290 
291 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
292 BPF_CALL_3(bpf_probe_read_compat, void *, dst, u32, size,
293 	   const void *, unsafe_ptr)
294 {
295 	if ((unsigned long)unsafe_ptr < TASK_SIZE) {
296 		return bpf_probe_read_user_common(dst, size,
297 				(__force void __user *)unsafe_ptr);
298 	}
299 	return bpf_probe_read_kernel_common(dst, size, unsafe_ptr);
300 }
301 
302 static const struct bpf_func_proto bpf_probe_read_compat_proto = {
303 	.func		= bpf_probe_read_compat,
304 	.gpl_only	= true,
305 	.ret_type	= RET_INTEGER,
306 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
307 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
308 	.arg3_type	= ARG_ANYTHING,
309 };
310 
311 BPF_CALL_3(bpf_probe_read_compat_str, void *, dst, u32, size,
312 	   const void *, unsafe_ptr)
313 {
314 	if ((unsigned long)unsafe_ptr < TASK_SIZE) {
315 		return bpf_probe_read_user_str_common(dst, size,
316 				(__force void __user *)unsafe_ptr);
317 	}
318 	return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr);
319 }
320 
321 static const struct bpf_func_proto bpf_probe_read_compat_str_proto = {
322 	.func		= bpf_probe_read_compat_str,
323 	.gpl_only	= true,
324 	.ret_type	= RET_INTEGER,
325 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
326 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
327 	.arg3_type	= ARG_ANYTHING,
328 };
329 #endif /* CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE */
330 
331 BPF_CALL_3(bpf_probe_write_user, void __user *, unsafe_ptr, const void *, src,
332 	   u32, size)
333 {
334 	/*
335 	 * Ensure we're in user context which is safe for the helper to
336 	 * run. This helper has no business in a kthread.
337 	 *
338 	 * access_ok() should prevent writing to non-user memory, but in
339 	 * some situations (nommu, temporary switch, etc) access_ok() does
340 	 * not provide enough validation, hence the check on KERNEL_DS.
341 	 *
342 	 * nmi_uaccess_okay() ensures the probe is not run in an interim
343 	 * state, when the task or mm are switched. This is specifically
344 	 * required to prevent the use of temporary mm.
345 	 */
346 
347 	if (unlikely(in_interrupt() ||
348 		     current->flags & (PF_KTHREAD | PF_EXITING)))
349 		return -EPERM;
350 	if (unlikely(uaccess_kernel()))
351 		return -EPERM;
352 	if (unlikely(!nmi_uaccess_okay()))
353 		return -EPERM;
354 
355 	return copy_to_user_nofault(unsafe_ptr, src, size);
356 }
357 
358 static const struct bpf_func_proto bpf_probe_write_user_proto = {
359 	.func		= bpf_probe_write_user,
360 	.gpl_only	= true,
361 	.ret_type	= RET_INTEGER,
362 	.arg1_type	= ARG_ANYTHING,
363 	.arg2_type	= ARG_PTR_TO_MEM,
364 	.arg3_type	= ARG_CONST_SIZE,
365 };
366 
367 static const struct bpf_func_proto *bpf_get_probe_write_proto(void)
368 {
369 	if (!capable(CAP_SYS_ADMIN))
370 		return NULL;
371 
372 	pr_warn_ratelimited("%s[%d] is installing a program with bpf_probe_write_user helper that may corrupt user memory!",
373 			    current->comm, task_pid_nr(current));
374 
375 	return &bpf_probe_write_user_proto;
376 }
377 
378 static void bpf_trace_copy_string(char *buf, void *unsafe_ptr, char fmt_ptype,
379 		size_t bufsz)
380 {
381 	void __user *user_ptr = (__force void __user *)unsafe_ptr;
382 
383 	buf[0] = 0;
384 
385 	switch (fmt_ptype) {
386 	case 's':
387 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
388 		if ((unsigned long)unsafe_ptr < TASK_SIZE) {
389 			strncpy_from_user_nofault(buf, user_ptr, bufsz);
390 			break;
391 		}
392 		fallthrough;
393 #endif
394 	case 'k':
395 		strncpy_from_kernel_nofault(buf, unsafe_ptr, bufsz);
396 		break;
397 	case 'u':
398 		strncpy_from_user_nofault(buf, user_ptr, bufsz);
399 		break;
400 	}
401 }
402 
403 static DEFINE_RAW_SPINLOCK(trace_printk_lock);
404 
405 #define BPF_TRACE_PRINTK_SIZE   1024
406 
407 static __printf(1, 0) int bpf_do_trace_printk(const char *fmt, ...)
408 {
409 	static char buf[BPF_TRACE_PRINTK_SIZE];
410 	unsigned long flags;
411 	va_list ap;
412 	int ret;
413 
414 	raw_spin_lock_irqsave(&trace_printk_lock, flags);
415 	va_start(ap, fmt);
416 	ret = vsnprintf(buf, sizeof(buf), fmt, ap);
417 	va_end(ap);
418 	/* vsnprintf() will not append null for zero-length strings */
419 	if (ret == 0)
420 		buf[0] = '\0';
421 	trace_bpf_trace_printk(buf);
422 	raw_spin_unlock_irqrestore(&trace_printk_lock, flags);
423 
424 	return ret;
425 }
426 
427 /*
428  * Only limited trace_printk() conversion specifiers allowed:
429  * %d %i %u %x %ld %li %lu %lx %lld %lli %llu %llx %p %pB %pks %pus %s
430  */
431 BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1,
432 	   u64, arg2, u64, arg3)
433 {
434 	int i, mod[3] = {}, fmt_cnt = 0;
435 	char buf[64], fmt_ptype;
436 	void *unsafe_ptr = NULL;
437 	bool str_seen = false;
438 
439 	/*
440 	 * bpf_check()->check_func_arg()->check_stack_boundary()
441 	 * guarantees that fmt points to bpf program stack,
442 	 * fmt_size bytes of it were initialized and fmt_size > 0
443 	 */
444 	if (fmt[--fmt_size] != 0)
445 		return -EINVAL;
446 
447 	/* check format string for allowed specifiers */
448 	for (i = 0; i < fmt_size; i++) {
449 		if ((!isprint(fmt[i]) && !isspace(fmt[i])) || !isascii(fmt[i]))
450 			return -EINVAL;
451 
452 		if (fmt[i] != '%')
453 			continue;
454 
455 		if (fmt_cnt >= 3)
456 			return -EINVAL;
457 
458 		/* fmt[i] != 0 && fmt[last] == 0, so we can access fmt[i + 1] */
459 		i++;
460 		if (fmt[i] == 'l') {
461 			mod[fmt_cnt]++;
462 			i++;
463 		} else if (fmt[i] == 'p') {
464 			mod[fmt_cnt]++;
465 			if ((fmt[i + 1] == 'k' ||
466 			     fmt[i + 1] == 'u') &&
467 			    fmt[i + 2] == 's') {
468 				fmt_ptype = fmt[i + 1];
469 				i += 2;
470 				goto fmt_str;
471 			}
472 
473 			if (fmt[i + 1] == 'B') {
474 				i++;
475 				goto fmt_next;
476 			}
477 
478 			/* disallow any further format extensions */
479 			if (fmt[i + 1] != 0 &&
480 			    !isspace(fmt[i + 1]) &&
481 			    !ispunct(fmt[i + 1]))
482 				return -EINVAL;
483 
484 			goto fmt_next;
485 		} else if (fmt[i] == 's') {
486 			mod[fmt_cnt]++;
487 			fmt_ptype = fmt[i];
488 fmt_str:
489 			if (str_seen)
490 				/* allow only one '%s' per fmt string */
491 				return -EINVAL;
492 			str_seen = true;
493 
494 			if (fmt[i + 1] != 0 &&
495 			    !isspace(fmt[i + 1]) &&
496 			    !ispunct(fmt[i + 1]))
497 				return -EINVAL;
498 
499 			switch (fmt_cnt) {
500 			case 0:
501 				unsafe_ptr = (void *)(long)arg1;
502 				arg1 = (long)buf;
503 				break;
504 			case 1:
505 				unsafe_ptr = (void *)(long)arg2;
506 				arg2 = (long)buf;
507 				break;
508 			case 2:
509 				unsafe_ptr = (void *)(long)arg3;
510 				arg3 = (long)buf;
511 				break;
512 			}
513 
514 			bpf_trace_copy_string(buf, unsafe_ptr, fmt_ptype,
515 					sizeof(buf));
516 			goto fmt_next;
517 		}
518 
519 		if (fmt[i] == 'l') {
520 			mod[fmt_cnt]++;
521 			i++;
522 		}
523 
524 		if (fmt[i] != 'i' && fmt[i] != 'd' &&
525 		    fmt[i] != 'u' && fmt[i] != 'x')
526 			return -EINVAL;
527 fmt_next:
528 		fmt_cnt++;
529 	}
530 
531 /* Horrid workaround for getting va_list handling working with different
532  * argument type combinations generically for 32 and 64 bit archs.
533  */
534 #define __BPF_TP_EMIT()	__BPF_ARG3_TP()
535 #define __BPF_TP(...)							\
536 	bpf_do_trace_printk(fmt, ##__VA_ARGS__)
537 
538 #define __BPF_ARG1_TP(...)						\
539 	((mod[0] == 2 || (mod[0] == 1 && __BITS_PER_LONG == 64))	\
540 	  ? __BPF_TP(arg1, ##__VA_ARGS__)				\
541 	  : ((mod[0] == 1 || (mod[0] == 0 && __BITS_PER_LONG == 32))	\
542 	      ? __BPF_TP((long)arg1, ##__VA_ARGS__)			\
543 	      : __BPF_TP((u32)arg1, ##__VA_ARGS__)))
544 
545 #define __BPF_ARG2_TP(...)						\
546 	((mod[1] == 2 || (mod[1] == 1 && __BITS_PER_LONG == 64))	\
547 	  ? __BPF_ARG1_TP(arg2, ##__VA_ARGS__)				\
548 	  : ((mod[1] == 1 || (mod[1] == 0 && __BITS_PER_LONG == 32))	\
549 	      ? __BPF_ARG1_TP((long)arg2, ##__VA_ARGS__)		\
550 	      : __BPF_ARG1_TP((u32)arg2, ##__VA_ARGS__)))
551 
552 #define __BPF_ARG3_TP(...)						\
553 	((mod[2] == 2 || (mod[2] == 1 && __BITS_PER_LONG == 64))	\
554 	  ? __BPF_ARG2_TP(arg3, ##__VA_ARGS__)				\
555 	  : ((mod[2] == 1 || (mod[2] == 0 && __BITS_PER_LONG == 32))	\
556 	      ? __BPF_ARG2_TP((long)arg3, ##__VA_ARGS__)		\
557 	      : __BPF_ARG2_TP((u32)arg3, ##__VA_ARGS__)))
558 
559 	return __BPF_TP_EMIT();
560 }
561 
562 static const struct bpf_func_proto bpf_trace_printk_proto = {
563 	.func		= bpf_trace_printk,
564 	.gpl_only	= true,
565 	.ret_type	= RET_INTEGER,
566 	.arg1_type	= ARG_PTR_TO_MEM,
567 	.arg2_type	= ARG_CONST_SIZE,
568 };
569 
570 const struct bpf_func_proto *bpf_get_trace_printk_proto(void)
571 {
572 	/*
573 	 * This program might be calling bpf_trace_printk,
574 	 * so enable the associated bpf_trace/bpf_trace_printk event.
575 	 * Repeat this each time as it is possible a user has
576 	 * disabled bpf_trace_printk events.  By loading a program
577 	 * calling bpf_trace_printk() however the user has expressed
578 	 * the intent to see such events.
579 	 */
580 	if (trace_set_clr_event("bpf_trace", "bpf_trace_printk", 1))
581 		pr_warn_ratelimited("could not enable bpf_trace_printk events");
582 
583 	return &bpf_trace_printk_proto;
584 }
585 
586 #define MAX_SEQ_PRINTF_VARARGS		12
587 #define MAX_SEQ_PRINTF_MAX_MEMCPY	6
588 #define MAX_SEQ_PRINTF_STR_LEN		128
589 
590 struct bpf_seq_printf_buf {
591 	char buf[MAX_SEQ_PRINTF_MAX_MEMCPY][MAX_SEQ_PRINTF_STR_LEN];
592 };
593 static DEFINE_PER_CPU(struct bpf_seq_printf_buf, bpf_seq_printf_buf);
594 static DEFINE_PER_CPU(int, bpf_seq_printf_buf_used);
595 
596 BPF_CALL_5(bpf_seq_printf, struct seq_file *, m, char *, fmt, u32, fmt_size,
597 	   const void *, data, u32, data_len)
598 {
599 	int err = -EINVAL, fmt_cnt = 0, memcpy_cnt = 0;
600 	int i, buf_used, copy_size, num_args;
601 	u64 params[MAX_SEQ_PRINTF_VARARGS];
602 	struct bpf_seq_printf_buf *bufs;
603 	const u64 *args = data;
604 
605 	buf_used = this_cpu_inc_return(bpf_seq_printf_buf_used);
606 	if (WARN_ON_ONCE(buf_used > 1)) {
607 		err = -EBUSY;
608 		goto out;
609 	}
610 
611 	bufs = this_cpu_ptr(&bpf_seq_printf_buf);
612 
613 	/*
614 	 * bpf_check()->check_func_arg()->check_stack_boundary()
615 	 * guarantees that fmt points to bpf program stack,
616 	 * fmt_size bytes of it were initialized and fmt_size > 0
617 	 */
618 	if (fmt[--fmt_size] != 0)
619 		goto out;
620 
621 	if (data_len & 7)
622 		goto out;
623 
624 	for (i = 0; i < fmt_size; i++) {
625 		if (fmt[i] == '%') {
626 			if (fmt[i + 1] == '%')
627 				i++;
628 			else if (!data || !data_len)
629 				goto out;
630 		}
631 	}
632 
633 	num_args = data_len / 8;
634 
635 	/* check format string for allowed specifiers */
636 	for (i = 0; i < fmt_size; i++) {
637 		/* only printable ascii for now. */
638 		if ((!isprint(fmt[i]) && !isspace(fmt[i])) || !isascii(fmt[i])) {
639 			err = -EINVAL;
640 			goto out;
641 		}
642 
643 		if (fmt[i] != '%')
644 			continue;
645 
646 		if (fmt[i + 1] == '%') {
647 			i++;
648 			continue;
649 		}
650 
651 		if (fmt_cnt >= MAX_SEQ_PRINTF_VARARGS) {
652 			err = -E2BIG;
653 			goto out;
654 		}
655 
656 		if (fmt_cnt >= num_args) {
657 			err = -EINVAL;
658 			goto out;
659 		}
660 
661 		/* fmt[i] != 0 && fmt[last] == 0, so we can access fmt[i + 1] */
662 		i++;
663 
664 		/* skip optional "[0 +-][num]" width formating field */
665 		while (fmt[i] == '0' || fmt[i] == '+'  || fmt[i] == '-' ||
666 		       fmt[i] == ' ')
667 			i++;
668 		if (fmt[i] >= '1' && fmt[i] <= '9') {
669 			i++;
670 			while (fmt[i] >= '0' && fmt[i] <= '9')
671 				i++;
672 		}
673 
674 		if (fmt[i] == 's') {
675 			void *unsafe_ptr;
676 
677 			/* try our best to copy */
678 			if (memcpy_cnt >= MAX_SEQ_PRINTF_MAX_MEMCPY) {
679 				err = -E2BIG;
680 				goto out;
681 			}
682 
683 			unsafe_ptr = (void *)(long)args[fmt_cnt];
684 			err = strncpy_from_kernel_nofault(bufs->buf[memcpy_cnt],
685 					unsafe_ptr, MAX_SEQ_PRINTF_STR_LEN);
686 			if (err < 0)
687 				bufs->buf[memcpy_cnt][0] = '\0';
688 			params[fmt_cnt] = (u64)(long)bufs->buf[memcpy_cnt];
689 
690 			fmt_cnt++;
691 			memcpy_cnt++;
692 			continue;
693 		}
694 
695 		if (fmt[i] == 'p') {
696 			if (fmt[i + 1] == 0 ||
697 			    fmt[i + 1] == 'K' ||
698 			    fmt[i + 1] == 'x' ||
699 			    fmt[i + 1] == 'B') {
700 				/* just kernel pointers */
701 				params[fmt_cnt] = args[fmt_cnt];
702 				fmt_cnt++;
703 				continue;
704 			}
705 
706 			/* only support "%pI4", "%pi4", "%pI6" and "%pi6". */
707 			if (fmt[i + 1] != 'i' && fmt[i + 1] != 'I') {
708 				err = -EINVAL;
709 				goto out;
710 			}
711 			if (fmt[i + 2] != '4' && fmt[i + 2] != '6') {
712 				err = -EINVAL;
713 				goto out;
714 			}
715 
716 			if (memcpy_cnt >= MAX_SEQ_PRINTF_MAX_MEMCPY) {
717 				err = -E2BIG;
718 				goto out;
719 			}
720 
721 
722 			copy_size = (fmt[i + 2] == '4') ? 4 : 16;
723 
724 			err = copy_from_kernel_nofault(bufs->buf[memcpy_cnt],
725 						(void *) (long) args[fmt_cnt],
726 						copy_size);
727 			if (err < 0)
728 				memset(bufs->buf[memcpy_cnt], 0, copy_size);
729 			params[fmt_cnt] = (u64)(long)bufs->buf[memcpy_cnt];
730 
731 			i += 2;
732 			fmt_cnt++;
733 			memcpy_cnt++;
734 			continue;
735 		}
736 
737 		if (fmt[i] == 'l') {
738 			i++;
739 			if (fmt[i] == 'l')
740 				i++;
741 		}
742 
743 		if (fmt[i] != 'i' && fmt[i] != 'd' &&
744 		    fmt[i] != 'u' && fmt[i] != 'x' &&
745 		    fmt[i] != 'X') {
746 			err = -EINVAL;
747 			goto out;
748 		}
749 
750 		params[fmt_cnt] = args[fmt_cnt];
751 		fmt_cnt++;
752 	}
753 
754 	/* Maximumly we can have MAX_SEQ_PRINTF_VARARGS parameter, just give
755 	 * all of them to seq_printf().
756 	 */
757 	seq_printf(m, fmt, params[0], params[1], params[2], params[3],
758 		   params[4], params[5], params[6], params[7], params[8],
759 		   params[9], params[10], params[11]);
760 
761 	err = seq_has_overflowed(m) ? -EOVERFLOW : 0;
762 out:
763 	this_cpu_dec(bpf_seq_printf_buf_used);
764 	return err;
765 }
766 
767 BTF_ID_LIST_SINGLE(btf_seq_file_ids, struct, seq_file)
768 
769 static const struct bpf_func_proto bpf_seq_printf_proto = {
770 	.func		= bpf_seq_printf,
771 	.gpl_only	= true,
772 	.ret_type	= RET_INTEGER,
773 	.arg1_type	= ARG_PTR_TO_BTF_ID,
774 	.arg1_btf_id	= &btf_seq_file_ids[0],
775 	.arg2_type	= ARG_PTR_TO_MEM,
776 	.arg3_type	= ARG_CONST_SIZE,
777 	.arg4_type      = ARG_PTR_TO_MEM_OR_NULL,
778 	.arg5_type      = ARG_CONST_SIZE_OR_ZERO,
779 };
780 
781 BPF_CALL_3(bpf_seq_write, struct seq_file *, m, const void *, data, u32, len)
782 {
783 	return seq_write(m, data, len) ? -EOVERFLOW : 0;
784 }
785 
786 static const struct bpf_func_proto bpf_seq_write_proto = {
787 	.func		= bpf_seq_write,
788 	.gpl_only	= true,
789 	.ret_type	= RET_INTEGER,
790 	.arg1_type	= ARG_PTR_TO_BTF_ID,
791 	.arg1_btf_id	= &btf_seq_file_ids[0],
792 	.arg2_type	= ARG_PTR_TO_MEM,
793 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
794 };
795 
796 BPF_CALL_4(bpf_seq_printf_btf, struct seq_file *, m, struct btf_ptr *, ptr,
797 	   u32, btf_ptr_size, u64, flags)
798 {
799 	const struct btf *btf;
800 	s32 btf_id;
801 	int ret;
802 
803 	ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id);
804 	if (ret)
805 		return ret;
806 
807 	return btf_type_seq_show_flags(btf, btf_id, ptr->ptr, m, flags);
808 }
809 
810 static const struct bpf_func_proto bpf_seq_printf_btf_proto = {
811 	.func		= bpf_seq_printf_btf,
812 	.gpl_only	= true,
813 	.ret_type	= RET_INTEGER,
814 	.arg1_type	= ARG_PTR_TO_BTF_ID,
815 	.arg1_btf_id	= &btf_seq_file_ids[0],
816 	.arg2_type	= ARG_PTR_TO_MEM,
817 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
818 	.arg4_type	= ARG_ANYTHING,
819 };
820 
821 static __always_inline int
822 get_map_perf_counter(struct bpf_map *map, u64 flags,
823 		     u64 *value, u64 *enabled, u64 *running)
824 {
825 	struct bpf_array *array = container_of(map, struct bpf_array, map);
826 	unsigned int cpu = smp_processor_id();
827 	u64 index = flags & BPF_F_INDEX_MASK;
828 	struct bpf_event_entry *ee;
829 
830 	if (unlikely(flags & ~(BPF_F_INDEX_MASK)))
831 		return -EINVAL;
832 	if (index == BPF_F_CURRENT_CPU)
833 		index = cpu;
834 	if (unlikely(index >= array->map.max_entries))
835 		return -E2BIG;
836 
837 	ee = READ_ONCE(array->ptrs[index]);
838 	if (!ee)
839 		return -ENOENT;
840 
841 	return perf_event_read_local(ee->event, value, enabled, running);
842 }
843 
844 BPF_CALL_2(bpf_perf_event_read, struct bpf_map *, map, u64, flags)
845 {
846 	u64 value = 0;
847 	int err;
848 
849 	err = get_map_perf_counter(map, flags, &value, NULL, NULL);
850 	/*
851 	 * this api is ugly since we miss [-22..-2] range of valid
852 	 * counter values, but that's uapi
853 	 */
854 	if (err)
855 		return err;
856 	return value;
857 }
858 
859 static const struct bpf_func_proto bpf_perf_event_read_proto = {
860 	.func		= bpf_perf_event_read,
861 	.gpl_only	= true,
862 	.ret_type	= RET_INTEGER,
863 	.arg1_type	= ARG_CONST_MAP_PTR,
864 	.arg2_type	= ARG_ANYTHING,
865 };
866 
867 BPF_CALL_4(bpf_perf_event_read_value, struct bpf_map *, map, u64, flags,
868 	   struct bpf_perf_event_value *, buf, u32, size)
869 {
870 	int err = -EINVAL;
871 
872 	if (unlikely(size != sizeof(struct bpf_perf_event_value)))
873 		goto clear;
874 	err = get_map_perf_counter(map, flags, &buf->counter, &buf->enabled,
875 				   &buf->running);
876 	if (unlikely(err))
877 		goto clear;
878 	return 0;
879 clear:
880 	memset(buf, 0, size);
881 	return err;
882 }
883 
884 static const struct bpf_func_proto bpf_perf_event_read_value_proto = {
885 	.func		= bpf_perf_event_read_value,
886 	.gpl_only	= true,
887 	.ret_type	= RET_INTEGER,
888 	.arg1_type	= ARG_CONST_MAP_PTR,
889 	.arg2_type	= ARG_ANYTHING,
890 	.arg3_type	= ARG_PTR_TO_UNINIT_MEM,
891 	.arg4_type	= ARG_CONST_SIZE,
892 };
893 
894 static __always_inline u64
895 __bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map,
896 			u64 flags, struct perf_sample_data *sd)
897 {
898 	struct bpf_array *array = container_of(map, struct bpf_array, map);
899 	unsigned int cpu = smp_processor_id();
900 	u64 index = flags & BPF_F_INDEX_MASK;
901 	struct bpf_event_entry *ee;
902 	struct perf_event *event;
903 
904 	if (index == BPF_F_CURRENT_CPU)
905 		index = cpu;
906 	if (unlikely(index >= array->map.max_entries))
907 		return -E2BIG;
908 
909 	ee = READ_ONCE(array->ptrs[index]);
910 	if (!ee)
911 		return -ENOENT;
912 
913 	event = ee->event;
914 	if (unlikely(event->attr.type != PERF_TYPE_SOFTWARE ||
915 		     event->attr.config != PERF_COUNT_SW_BPF_OUTPUT))
916 		return -EINVAL;
917 
918 	if (unlikely(event->oncpu != cpu))
919 		return -EOPNOTSUPP;
920 
921 	return perf_event_output(event, sd, regs);
922 }
923 
924 /*
925  * Support executing tracepoints in normal, irq, and nmi context that each call
926  * bpf_perf_event_output
927  */
928 struct bpf_trace_sample_data {
929 	struct perf_sample_data sds[3];
930 };
931 
932 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_trace_sds);
933 static DEFINE_PER_CPU(int, bpf_trace_nest_level);
934 BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map,
935 	   u64, flags, void *, data, u64, size)
936 {
937 	struct bpf_trace_sample_data *sds = this_cpu_ptr(&bpf_trace_sds);
938 	int nest_level = this_cpu_inc_return(bpf_trace_nest_level);
939 	struct perf_raw_record raw = {
940 		.frag = {
941 			.size = size,
942 			.data = data,
943 		},
944 	};
945 	struct perf_sample_data *sd;
946 	int err;
947 
948 	if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(sds->sds))) {
949 		err = -EBUSY;
950 		goto out;
951 	}
952 
953 	sd = &sds->sds[nest_level - 1];
954 
955 	if (unlikely(flags & ~(BPF_F_INDEX_MASK))) {
956 		err = -EINVAL;
957 		goto out;
958 	}
959 
960 	perf_sample_data_init(sd, 0, 0);
961 	sd->raw = &raw;
962 
963 	err = __bpf_perf_event_output(regs, map, flags, sd);
964 
965 out:
966 	this_cpu_dec(bpf_trace_nest_level);
967 	return err;
968 }
969 
970 static const struct bpf_func_proto bpf_perf_event_output_proto = {
971 	.func		= bpf_perf_event_output,
972 	.gpl_only	= true,
973 	.ret_type	= RET_INTEGER,
974 	.arg1_type	= ARG_PTR_TO_CTX,
975 	.arg2_type	= ARG_CONST_MAP_PTR,
976 	.arg3_type	= ARG_ANYTHING,
977 	.arg4_type	= ARG_PTR_TO_MEM,
978 	.arg5_type	= ARG_CONST_SIZE_OR_ZERO,
979 };
980 
981 static DEFINE_PER_CPU(int, bpf_event_output_nest_level);
982 struct bpf_nested_pt_regs {
983 	struct pt_regs regs[3];
984 };
985 static DEFINE_PER_CPU(struct bpf_nested_pt_regs, bpf_pt_regs);
986 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_misc_sds);
987 
988 u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
989 		     void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy)
990 {
991 	int nest_level = this_cpu_inc_return(bpf_event_output_nest_level);
992 	struct perf_raw_frag frag = {
993 		.copy		= ctx_copy,
994 		.size		= ctx_size,
995 		.data		= ctx,
996 	};
997 	struct perf_raw_record raw = {
998 		.frag = {
999 			{
1000 				.next	= ctx_size ? &frag : NULL,
1001 			},
1002 			.size	= meta_size,
1003 			.data	= meta,
1004 		},
1005 	};
1006 	struct perf_sample_data *sd;
1007 	struct pt_regs *regs;
1008 	u64 ret;
1009 
1010 	if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(bpf_misc_sds.sds))) {
1011 		ret = -EBUSY;
1012 		goto out;
1013 	}
1014 	sd = this_cpu_ptr(&bpf_misc_sds.sds[nest_level - 1]);
1015 	regs = this_cpu_ptr(&bpf_pt_regs.regs[nest_level - 1]);
1016 
1017 	perf_fetch_caller_regs(regs);
1018 	perf_sample_data_init(sd, 0, 0);
1019 	sd->raw = &raw;
1020 
1021 	ret = __bpf_perf_event_output(regs, map, flags, sd);
1022 out:
1023 	this_cpu_dec(bpf_event_output_nest_level);
1024 	return ret;
1025 }
1026 
1027 BPF_CALL_0(bpf_get_current_task)
1028 {
1029 	return (long) current;
1030 }
1031 
1032 const struct bpf_func_proto bpf_get_current_task_proto = {
1033 	.func		= bpf_get_current_task,
1034 	.gpl_only	= true,
1035 	.ret_type	= RET_INTEGER,
1036 };
1037 
1038 BPF_CALL_0(bpf_get_current_task_btf)
1039 {
1040 	return (unsigned long) current;
1041 }
1042 
1043 BTF_ID_LIST_SINGLE(bpf_get_current_btf_ids, struct, task_struct)
1044 
1045 static const struct bpf_func_proto bpf_get_current_task_btf_proto = {
1046 	.func		= bpf_get_current_task_btf,
1047 	.gpl_only	= true,
1048 	.ret_type	= RET_PTR_TO_BTF_ID,
1049 	.ret_btf_id	= &bpf_get_current_btf_ids[0],
1050 };
1051 
1052 BPF_CALL_2(bpf_current_task_under_cgroup, struct bpf_map *, map, u32, idx)
1053 {
1054 	struct bpf_array *array = container_of(map, struct bpf_array, map);
1055 	struct cgroup *cgrp;
1056 
1057 	if (unlikely(idx >= array->map.max_entries))
1058 		return -E2BIG;
1059 
1060 	cgrp = READ_ONCE(array->ptrs[idx]);
1061 	if (unlikely(!cgrp))
1062 		return -EAGAIN;
1063 
1064 	return task_under_cgroup_hierarchy(current, cgrp);
1065 }
1066 
1067 static const struct bpf_func_proto bpf_current_task_under_cgroup_proto = {
1068 	.func           = bpf_current_task_under_cgroup,
1069 	.gpl_only       = false,
1070 	.ret_type       = RET_INTEGER,
1071 	.arg1_type      = ARG_CONST_MAP_PTR,
1072 	.arg2_type      = ARG_ANYTHING,
1073 };
1074 
1075 struct send_signal_irq_work {
1076 	struct irq_work irq_work;
1077 	struct task_struct *task;
1078 	u32 sig;
1079 	enum pid_type type;
1080 };
1081 
1082 static DEFINE_PER_CPU(struct send_signal_irq_work, send_signal_work);
1083 
1084 static void do_bpf_send_signal(struct irq_work *entry)
1085 {
1086 	struct send_signal_irq_work *work;
1087 
1088 	work = container_of(entry, struct send_signal_irq_work, irq_work);
1089 	group_send_sig_info(work->sig, SEND_SIG_PRIV, work->task, work->type);
1090 }
1091 
1092 static int bpf_send_signal_common(u32 sig, enum pid_type type)
1093 {
1094 	struct send_signal_irq_work *work = NULL;
1095 
1096 	/* Similar to bpf_probe_write_user, task needs to be
1097 	 * in a sound condition and kernel memory access be
1098 	 * permitted in order to send signal to the current
1099 	 * task.
1100 	 */
1101 	if (unlikely(current->flags & (PF_KTHREAD | PF_EXITING)))
1102 		return -EPERM;
1103 	if (unlikely(uaccess_kernel()))
1104 		return -EPERM;
1105 	if (unlikely(!nmi_uaccess_okay()))
1106 		return -EPERM;
1107 
1108 	if (irqs_disabled()) {
1109 		/* Do an early check on signal validity. Otherwise,
1110 		 * the error is lost in deferred irq_work.
1111 		 */
1112 		if (unlikely(!valid_signal(sig)))
1113 			return -EINVAL;
1114 
1115 		work = this_cpu_ptr(&send_signal_work);
1116 		if (irq_work_is_busy(&work->irq_work))
1117 			return -EBUSY;
1118 
1119 		/* Add the current task, which is the target of sending signal,
1120 		 * to the irq_work. The current task may change when queued
1121 		 * irq works get executed.
1122 		 */
1123 		work->task = current;
1124 		work->sig = sig;
1125 		work->type = type;
1126 		irq_work_queue(&work->irq_work);
1127 		return 0;
1128 	}
1129 
1130 	return group_send_sig_info(sig, SEND_SIG_PRIV, current, type);
1131 }
1132 
1133 BPF_CALL_1(bpf_send_signal, u32, sig)
1134 {
1135 	return bpf_send_signal_common(sig, PIDTYPE_TGID);
1136 }
1137 
1138 static const struct bpf_func_proto bpf_send_signal_proto = {
1139 	.func		= bpf_send_signal,
1140 	.gpl_only	= false,
1141 	.ret_type	= RET_INTEGER,
1142 	.arg1_type	= ARG_ANYTHING,
1143 };
1144 
1145 BPF_CALL_1(bpf_send_signal_thread, u32, sig)
1146 {
1147 	return bpf_send_signal_common(sig, PIDTYPE_PID);
1148 }
1149 
1150 static const struct bpf_func_proto bpf_send_signal_thread_proto = {
1151 	.func		= bpf_send_signal_thread,
1152 	.gpl_only	= false,
1153 	.ret_type	= RET_INTEGER,
1154 	.arg1_type	= ARG_ANYTHING,
1155 };
1156 
1157 BPF_CALL_3(bpf_d_path, struct path *, path, char *, buf, u32, sz)
1158 {
1159 	long len;
1160 	char *p;
1161 
1162 	if (!sz)
1163 		return 0;
1164 
1165 	p = d_path(path, buf, sz);
1166 	if (IS_ERR(p)) {
1167 		len = PTR_ERR(p);
1168 	} else {
1169 		len = buf + sz - p;
1170 		memmove(buf, p, len);
1171 	}
1172 
1173 	return len;
1174 }
1175 
1176 BTF_SET_START(btf_allowlist_d_path)
1177 #ifdef CONFIG_SECURITY
1178 BTF_ID(func, security_file_permission)
1179 BTF_ID(func, security_inode_getattr)
1180 BTF_ID(func, security_file_open)
1181 #endif
1182 #ifdef CONFIG_SECURITY_PATH
1183 BTF_ID(func, security_path_truncate)
1184 #endif
1185 BTF_ID(func, vfs_truncate)
1186 BTF_ID(func, vfs_fallocate)
1187 BTF_ID(func, dentry_open)
1188 BTF_ID(func, vfs_getattr)
1189 BTF_ID(func, filp_close)
1190 BTF_SET_END(btf_allowlist_d_path)
1191 
1192 static bool bpf_d_path_allowed(const struct bpf_prog *prog)
1193 {
1194 	if (prog->type == BPF_PROG_TYPE_LSM)
1195 		return bpf_lsm_is_sleepable_hook(prog->aux->attach_btf_id);
1196 
1197 	return btf_id_set_contains(&btf_allowlist_d_path,
1198 				   prog->aux->attach_btf_id);
1199 }
1200 
1201 BTF_ID_LIST_SINGLE(bpf_d_path_btf_ids, struct, path)
1202 
1203 static const struct bpf_func_proto bpf_d_path_proto = {
1204 	.func		= bpf_d_path,
1205 	.gpl_only	= false,
1206 	.ret_type	= RET_INTEGER,
1207 	.arg1_type	= ARG_PTR_TO_BTF_ID,
1208 	.arg1_btf_id	= &bpf_d_path_btf_ids[0],
1209 	.arg2_type	= ARG_PTR_TO_MEM,
1210 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
1211 	.allowed	= bpf_d_path_allowed,
1212 };
1213 
1214 #define BTF_F_ALL	(BTF_F_COMPACT  | BTF_F_NONAME | \
1215 			 BTF_F_PTR_RAW | BTF_F_ZERO)
1216 
1217 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size,
1218 				  u64 flags, const struct btf **btf,
1219 				  s32 *btf_id)
1220 {
1221 	const struct btf_type *t;
1222 
1223 	if (unlikely(flags & ~(BTF_F_ALL)))
1224 		return -EINVAL;
1225 
1226 	if (btf_ptr_size != sizeof(struct btf_ptr))
1227 		return -EINVAL;
1228 
1229 	*btf = bpf_get_btf_vmlinux();
1230 
1231 	if (IS_ERR_OR_NULL(*btf))
1232 		return IS_ERR(*btf) ? PTR_ERR(*btf) : -EINVAL;
1233 
1234 	if (ptr->type_id > 0)
1235 		*btf_id = ptr->type_id;
1236 	else
1237 		return -EINVAL;
1238 
1239 	if (*btf_id > 0)
1240 		t = btf_type_by_id(*btf, *btf_id);
1241 	if (*btf_id <= 0 || !t)
1242 		return -ENOENT;
1243 
1244 	return 0;
1245 }
1246 
1247 BPF_CALL_5(bpf_snprintf_btf, char *, str, u32, str_size, struct btf_ptr *, ptr,
1248 	   u32, btf_ptr_size, u64, flags)
1249 {
1250 	const struct btf *btf;
1251 	s32 btf_id;
1252 	int ret;
1253 
1254 	ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id);
1255 	if (ret)
1256 		return ret;
1257 
1258 	return btf_type_snprintf_show(btf, btf_id, ptr->ptr, str, str_size,
1259 				      flags);
1260 }
1261 
1262 const struct bpf_func_proto bpf_snprintf_btf_proto = {
1263 	.func		= bpf_snprintf_btf,
1264 	.gpl_only	= false,
1265 	.ret_type	= RET_INTEGER,
1266 	.arg1_type	= ARG_PTR_TO_MEM,
1267 	.arg2_type	= ARG_CONST_SIZE,
1268 	.arg3_type	= ARG_PTR_TO_MEM,
1269 	.arg4_type	= ARG_CONST_SIZE,
1270 	.arg5_type	= ARG_ANYTHING,
1271 };
1272 
1273 const struct bpf_func_proto *
1274 bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1275 {
1276 	switch (func_id) {
1277 	case BPF_FUNC_map_lookup_elem:
1278 		return &bpf_map_lookup_elem_proto;
1279 	case BPF_FUNC_map_update_elem:
1280 		return &bpf_map_update_elem_proto;
1281 	case BPF_FUNC_map_delete_elem:
1282 		return &bpf_map_delete_elem_proto;
1283 	case BPF_FUNC_map_push_elem:
1284 		return &bpf_map_push_elem_proto;
1285 	case BPF_FUNC_map_pop_elem:
1286 		return &bpf_map_pop_elem_proto;
1287 	case BPF_FUNC_map_peek_elem:
1288 		return &bpf_map_peek_elem_proto;
1289 	case BPF_FUNC_ktime_get_ns:
1290 		return &bpf_ktime_get_ns_proto;
1291 	case BPF_FUNC_ktime_get_boot_ns:
1292 		return &bpf_ktime_get_boot_ns_proto;
1293 	case BPF_FUNC_ktime_get_coarse_ns:
1294 		return &bpf_ktime_get_coarse_ns_proto;
1295 	case BPF_FUNC_tail_call:
1296 		return &bpf_tail_call_proto;
1297 	case BPF_FUNC_get_current_pid_tgid:
1298 		return &bpf_get_current_pid_tgid_proto;
1299 	case BPF_FUNC_get_current_task:
1300 		return &bpf_get_current_task_proto;
1301 	case BPF_FUNC_get_current_task_btf:
1302 		return &bpf_get_current_task_btf_proto;
1303 	case BPF_FUNC_get_current_uid_gid:
1304 		return &bpf_get_current_uid_gid_proto;
1305 	case BPF_FUNC_get_current_comm:
1306 		return &bpf_get_current_comm_proto;
1307 	case BPF_FUNC_trace_printk:
1308 		return bpf_get_trace_printk_proto();
1309 	case BPF_FUNC_get_smp_processor_id:
1310 		return &bpf_get_smp_processor_id_proto;
1311 	case BPF_FUNC_get_numa_node_id:
1312 		return &bpf_get_numa_node_id_proto;
1313 	case BPF_FUNC_perf_event_read:
1314 		return &bpf_perf_event_read_proto;
1315 	case BPF_FUNC_probe_write_user:
1316 		return bpf_get_probe_write_proto();
1317 	case BPF_FUNC_current_task_under_cgroup:
1318 		return &bpf_current_task_under_cgroup_proto;
1319 	case BPF_FUNC_get_prandom_u32:
1320 		return &bpf_get_prandom_u32_proto;
1321 	case BPF_FUNC_probe_read_user:
1322 		return &bpf_probe_read_user_proto;
1323 	case BPF_FUNC_probe_read_kernel:
1324 		return &bpf_probe_read_kernel_proto;
1325 	case BPF_FUNC_probe_read_user_str:
1326 		return &bpf_probe_read_user_str_proto;
1327 	case BPF_FUNC_probe_read_kernel_str:
1328 		return &bpf_probe_read_kernel_str_proto;
1329 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
1330 	case BPF_FUNC_probe_read:
1331 		return &bpf_probe_read_compat_proto;
1332 	case BPF_FUNC_probe_read_str:
1333 		return &bpf_probe_read_compat_str_proto;
1334 #endif
1335 #ifdef CONFIG_CGROUPS
1336 	case BPF_FUNC_get_current_cgroup_id:
1337 		return &bpf_get_current_cgroup_id_proto;
1338 #endif
1339 	case BPF_FUNC_send_signal:
1340 		return &bpf_send_signal_proto;
1341 	case BPF_FUNC_send_signal_thread:
1342 		return &bpf_send_signal_thread_proto;
1343 	case BPF_FUNC_perf_event_read_value:
1344 		return &bpf_perf_event_read_value_proto;
1345 	case BPF_FUNC_get_ns_current_pid_tgid:
1346 		return &bpf_get_ns_current_pid_tgid_proto;
1347 	case BPF_FUNC_ringbuf_output:
1348 		return &bpf_ringbuf_output_proto;
1349 	case BPF_FUNC_ringbuf_reserve:
1350 		return &bpf_ringbuf_reserve_proto;
1351 	case BPF_FUNC_ringbuf_submit:
1352 		return &bpf_ringbuf_submit_proto;
1353 	case BPF_FUNC_ringbuf_discard:
1354 		return &bpf_ringbuf_discard_proto;
1355 	case BPF_FUNC_ringbuf_query:
1356 		return &bpf_ringbuf_query_proto;
1357 	case BPF_FUNC_jiffies64:
1358 		return &bpf_jiffies64_proto;
1359 	case BPF_FUNC_get_task_stack:
1360 		return &bpf_get_task_stack_proto;
1361 	case BPF_FUNC_copy_from_user:
1362 		return prog->aux->sleepable ? &bpf_copy_from_user_proto : NULL;
1363 	case BPF_FUNC_snprintf_btf:
1364 		return &bpf_snprintf_btf_proto;
1365 	case BPF_FUNC_per_cpu_ptr:
1366 		return &bpf_per_cpu_ptr_proto;
1367 	case BPF_FUNC_this_cpu_ptr:
1368 		return &bpf_this_cpu_ptr_proto;
1369 	default:
1370 		return NULL;
1371 	}
1372 }
1373 
1374 static const struct bpf_func_proto *
1375 kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1376 {
1377 	switch (func_id) {
1378 	case BPF_FUNC_perf_event_output:
1379 		return &bpf_perf_event_output_proto;
1380 	case BPF_FUNC_get_stackid:
1381 		return &bpf_get_stackid_proto;
1382 	case BPF_FUNC_get_stack:
1383 		return &bpf_get_stack_proto;
1384 #ifdef CONFIG_BPF_KPROBE_OVERRIDE
1385 	case BPF_FUNC_override_return:
1386 		return &bpf_override_return_proto;
1387 #endif
1388 	default:
1389 		return bpf_tracing_func_proto(func_id, prog);
1390 	}
1391 }
1392 
1393 /* bpf+kprobe programs can access fields of 'struct pt_regs' */
1394 static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
1395 					const struct bpf_prog *prog,
1396 					struct bpf_insn_access_aux *info)
1397 {
1398 	if (off < 0 || off >= sizeof(struct pt_regs))
1399 		return false;
1400 	if (type != BPF_READ)
1401 		return false;
1402 	if (off % size != 0)
1403 		return false;
1404 	/*
1405 	 * Assertion for 32 bit to make sure last 8 byte access
1406 	 * (BPF_DW) to the last 4 byte member is disallowed.
1407 	 */
1408 	if (off + size > sizeof(struct pt_regs))
1409 		return false;
1410 
1411 	return true;
1412 }
1413 
1414 const struct bpf_verifier_ops kprobe_verifier_ops = {
1415 	.get_func_proto  = kprobe_prog_func_proto,
1416 	.is_valid_access = kprobe_prog_is_valid_access,
1417 };
1418 
1419 const struct bpf_prog_ops kprobe_prog_ops = {
1420 };
1421 
1422 BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map,
1423 	   u64, flags, void *, data, u64, size)
1424 {
1425 	struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1426 
1427 	/*
1428 	 * r1 points to perf tracepoint buffer where first 8 bytes are hidden
1429 	 * from bpf program and contain a pointer to 'struct pt_regs'. Fetch it
1430 	 * from there and call the same bpf_perf_event_output() helper inline.
1431 	 */
1432 	return ____bpf_perf_event_output(regs, map, flags, data, size);
1433 }
1434 
1435 static const struct bpf_func_proto bpf_perf_event_output_proto_tp = {
1436 	.func		= bpf_perf_event_output_tp,
1437 	.gpl_only	= true,
1438 	.ret_type	= RET_INTEGER,
1439 	.arg1_type	= ARG_PTR_TO_CTX,
1440 	.arg2_type	= ARG_CONST_MAP_PTR,
1441 	.arg3_type	= ARG_ANYTHING,
1442 	.arg4_type	= ARG_PTR_TO_MEM,
1443 	.arg5_type	= ARG_CONST_SIZE_OR_ZERO,
1444 };
1445 
1446 BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map,
1447 	   u64, flags)
1448 {
1449 	struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1450 
1451 	/*
1452 	 * Same comment as in bpf_perf_event_output_tp(), only that this time
1453 	 * the other helper's function body cannot be inlined due to being
1454 	 * external, thus we need to call raw helper function.
1455 	 */
1456 	return bpf_get_stackid((unsigned long) regs, (unsigned long) map,
1457 			       flags, 0, 0);
1458 }
1459 
1460 static const struct bpf_func_proto bpf_get_stackid_proto_tp = {
1461 	.func		= bpf_get_stackid_tp,
1462 	.gpl_only	= true,
1463 	.ret_type	= RET_INTEGER,
1464 	.arg1_type	= ARG_PTR_TO_CTX,
1465 	.arg2_type	= ARG_CONST_MAP_PTR,
1466 	.arg3_type	= ARG_ANYTHING,
1467 };
1468 
1469 BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size,
1470 	   u64, flags)
1471 {
1472 	struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1473 
1474 	return bpf_get_stack((unsigned long) regs, (unsigned long) buf,
1475 			     (unsigned long) size, flags, 0);
1476 }
1477 
1478 static const struct bpf_func_proto bpf_get_stack_proto_tp = {
1479 	.func		= bpf_get_stack_tp,
1480 	.gpl_only	= true,
1481 	.ret_type	= RET_INTEGER,
1482 	.arg1_type	= ARG_PTR_TO_CTX,
1483 	.arg2_type	= ARG_PTR_TO_UNINIT_MEM,
1484 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
1485 	.arg4_type	= ARG_ANYTHING,
1486 };
1487 
1488 static const struct bpf_func_proto *
1489 tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1490 {
1491 	switch (func_id) {
1492 	case BPF_FUNC_perf_event_output:
1493 		return &bpf_perf_event_output_proto_tp;
1494 	case BPF_FUNC_get_stackid:
1495 		return &bpf_get_stackid_proto_tp;
1496 	case BPF_FUNC_get_stack:
1497 		return &bpf_get_stack_proto_tp;
1498 	default:
1499 		return bpf_tracing_func_proto(func_id, prog);
1500 	}
1501 }
1502 
1503 static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type,
1504 				    const struct bpf_prog *prog,
1505 				    struct bpf_insn_access_aux *info)
1506 {
1507 	if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE)
1508 		return false;
1509 	if (type != BPF_READ)
1510 		return false;
1511 	if (off % size != 0)
1512 		return false;
1513 
1514 	BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(__u64));
1515 	return true;
1516 }
1517 
1518 const struct bpf_verifier_ops tracepoint_verifier_ops = {
1519 	.get_func_proto  = tp_prog_func_proto,
1520 	.is_valid_access = tp_prog_is_valid_access,
1521 };
1522 
1523 const struct bpf_prog_ops tracepoint_prog_ops = {
1524 };
1525 
1526 BPF_CALL_3(bpf_perf_prog_read_value, struct bpf_perf_event_data_kern *, ctx,
1527 	   struct bpf_perf_event_value *, buf, u32, size)
1528 {
1529 	int err = -EINVAL;
1530 
1531 	if (unlikely(size != sizeof(struct bpf_perf_event_value)))
1532 		goto clear;
1533 	err = perf_event_read_local(ctx->event, &buf->counter, &buf->enabled,
1534 				    &buf->running);
1535 	if (unlikely(err))
1536 		goto clear;
1537 	return 0;
1538 clear:
1539 	memset(buf, 0, size);
1540 	return err;
1541 }
1542 
1543 static const struct bpf_func_proto bpf_perf_prog_read_value_proto = {
1544          .func           = bpf_perf_prog_read_value,
1545          .gpl_only       = true,
1546          .ret_type       = RET_INTEGER,
1547          .arg1_type      = ARG_PTR_TO_CTX,
1548          .arg2_type      = ARG_PTR_TO_UNINIT_MEM,
1549          .arg3_type      = ARG_CONST_SIZE,
1550 };
1551 
1552 BPF_CALL_4(bpf_read_branch_records, struct bpf_perf_event_data_kern *, ctx,
1553 	   void *, buf, u32, size, u64, flags)
1554 {
1555 #ifndef CONFIG_X86
1556 	return -ENOENT;
1557 #else
1558 	static const u32 br_entry_size = sizeof(struct perf_branch_entry);
1559 	struct perf_branch_stack *br_stack = ctx->data->br_stack;
1560 	u32 to_copy;
1561 
1562 	if (unlikely(flags & ~BPF_F_GET_BRANCH_RECORDS_SIZE))
1563 		return -EINVAL;
1564 
1565 	if (unlikely(!br_stack))
1566 		return -EINVAL;
1567 
1568 	if (flags & BPF_F_GET_BRANCH_RECORDS_SIZE)
1569 		return br_stack->nr * br_entry_size;
1570 
1571 	if (!buf || (size % br_entry_size != 0))
1572 		return -EINVAL;
1573 
1574 	to_copy = min_t(u32, br_stack->nr * br_entry_size, size);
1575 	memcpy(buf, br_stack->entries, to_copy);
1576 
1577 	return to_copy;
1578 #endif
1579 }
1580 
1581 static const struct bpf_func_proto bpf_read_branch_records_proto = {
1582 	.func           = bpf_read_branch_records,
1583 	.gpl_only       = true,
1584 	.ret_type       = RET_INTEGER,
1585 	.arg1_type      = ARG_PTR_TO_CTX,
1586 	.arg2_type      = ARG_PTR_TO_MEM_OR_NULL,
1587 	.arg3_type      = ARG_CONST_SIZE_OR_ZERO,
1588 	.arg4_type      = ARG_ANYTHING,
1589 };
1590 
1591 static const struct bpf_func_proto *
1592 pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1593 {
1594 	switch (func_id) {
1595 	case BPF_FUNC_perf_event_output:
1596 		return &bpf_perf_event_output_proto_tp;
1597 	case BPF_FUNC_get_stackid:
1598 		return &bpf_get_stackid_proto_pe;
1599 	case BPF_FUNC_get_stack:
1600 		return &bpf_get_stack_proto_pe;
1601 	case BPF_FUNC_perf_prog_read_value:
1602 		return &bpf_perf_prog_read_value_proto;
1603 	case BPF_FUNC_read_branch_records:
1604 		return &bpf_read_branch_records_proto;
1605 	default:
1606 		return bpf_tracing_func_proto(func_id, prog);
1607 	}
1608 }
1609 
1610 /*
1611  * bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp
1612  * to avoid potential recursive reuse issue when/if tracepoints are added
1613  * inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack.
1614  *
1615  * Since raw tracepoints run despite bpf_prog_active, support concurrent usage
1616  * in normal, irq, and nmi context.
1617  */
1618 struct bpf_raw_tp_regs {
1619 	struct pt_regs regs[3];
1620 };
1621 static DEFINE_PER_CPU(struct bpf_raw_tp_regs, bpf_raw_tp_regs);
1622 static DEFINE_PER_CPU(int, bpf_raw_tp_nest_level);
1623 static struct pt_regs *get_bpf_raw_tp_regs(void)
1624 {
1625 	struct bpf_raw_tp_regs *tp_regs = this_cpu_ptr(&bpf_raw_tp_regs);
1626 	int nest_level = this_cpu_inc_return(bpf_raw_tp_nest_level);
1627 
1628 	if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(tp_regs->regs))) {
1629 		this_cpu_dec(bpf_raw_tp_nest_level);
1630 		return ERR_PTR(-EBUSY);
1631 	}
1632 
1633 	return &tp_regs->regs[nest_level - 1];
1634 }
1635 
1636 static void put_bpf_raw_tp_regs(void)
1637 {
1638 	this_cpu_dec(bpf_raw_tp_nest_level);
1639 }
1640 
1641 BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args,
1642 	   struct bpf_map *, map, u64, flags, void *, data, u64, size)
1643 {
1644 	struct pt_regs *regs = get_bpf_raw_tp_regs();
1645 	int ret;
1646 
1647 	if (IS_ERR(regs))
1648 		return PTR_ERR(regs);
1649 
1650 	perf_fetch_caller_regs(regs);
1651 	ret = ____bpf_perf_event_output(regs, map, flags, data, size);
1652 
1653 	put_bpf_raw_tp_regs();
1654 	return ret;
1655 }
1656 
1657 static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = {
1658 	.func		= bpf_perf_event_output_raw_tp,
1659 	.gpl_only	= true,
1660 	.ret_type	= RET_INTEGER,
1661 	.arg1_type	= ARG_PTR_TO_CTX,
1662 	.arg2_type	= ARG_CONST_MAP_PTR,
1663 	.arg3_type	= ARG_ANYTHING,
1664 	.arg4_type	= ARG_PTR_TO_MEM,
1665 	.arg5_type	= ARG_CONST_SIZE_OR_ZERO,
1666 };
1667 
1668 extern const struct bpf_func_proto bpf_skb_output_proto;
1669 extern const struct bpf_func_proto bpf_xdp_output_proto;
1670 
1671 BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args,
1672 	   struct bpf_map *, map, u64, flags)
1673 {
1674 	struct pt_regs *regs = get_bpf_raw_tp_regs();
1675 	int ret;
1676 
1677 	if (IS_ERR(regs))
1678 		return PTR_ERR(regs);
1679 
1680 	perf_fetch_caller_regs(regs);
1681 	/* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */
1682 	ret = bpf_get_stackid((unsigned long) regs, (unsigned long) map,
1683 			      flags, 0, 0);
1684 	put_bpf_raw_tp_regs();
1685 	return ret;
1686 }
1687 
1688 static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = {
1689 	.func		= bpf_get_stackid_raw_tp,
1690 	.gpl_only	= true,
1691 	.ret_type	= RET_INTEGER,
1692 	.arg1_type	= ARG_PTR_TO_CTX,
1693 	.arg2_type	= ARG_CONST_MAP_PTR,
1694 	.arg3_type	= ARG_ANYTHING,
1695 };
1696 
1697 BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args,
1698 	   void *, buf, u32, size, u64, flags)
1699 {
1700 	struct pt_regs *regs = get_bpf_raw_tp_regs();
1701 	int ret;
1702 
1703 	if (IS_ERR(regs))
1704 		return PTR_ERR(regs);
1705 
1706 	perf_fetch_caller_regs(regs);
1707 	ret = bpf_get_stack((unsigned long) regs, (unsigned long) buf,
1708 			    (unsigned long) size, flags, 0);
1709 	put_bpf_raw_tp_regs();
1710 	return ret;
1711 }
1712 
1713 static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = {
1714 	.func		= bpf_get_stack_raw_tp,
1715 	.gpl_only	= true,
1716 	.ret_type	= RET_INTEGER,
1717 	.arg1_type	= ARG_PTR_TO_CTX,
1718 	.arg2_type	= ARG_PTR_TO_MEM,
1719 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
1720 	.arg4_type	= ARG_ANYTHING,
1721 };
1722 
1723 static const struct bpf_func_proto *
1724 raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1725 {
1726 	switch (func_id) {
1727 	case BPF_FUNC_perf_event_output:
1728 		return &bpf_perf_event_output_proto_raw_tp;
1729 	case BPF_FUNC_get_stackid:
1730 		return &bpf_get_stackid_proto_raw_tp;
1731 	case BPF_FUNC_get_stack:
1732 		return &bpf_get_stack_proto_raw_tp;
1733 	default:
1734 		return bpf_tracing_func_proto(func_id, prog);
1735 	}
1736 }
1737 
1738 const struct bpf_func_proto *
1739 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1740 {
1741 	switch (func_id) {
1742 #ifdef CONFIG_NET
1743 	case BPF_FUNC_skb_output:
1744 		return &bpf_skb_output_proto;
1745 	case BPF_FUNC_xdp_output:
1746 		return &bpf_xdp_output_proto;
1747 	case BPF_FUNC_skc_to_tcp6_sock:
1748 		return &bpf_skc_to_tcp6_sock_proto;
1749 	case BPF_FUNC_skc_to_tcp_sock:
1750 		return &bpf_skc_to_tcp_sock_proto;
1751 	case BPF_FUNC_skc_to_tcp_timewait_sock:
1752 		return &bpf_skc_to_tcp_timewait_sock_proto;
1753 	case BPF_FUNC_skc_to_tcp_request_sock:
1754 		return &bpf_skc_to_tcp_request_sock_proto;
1755 	case BPF_FUNC_skc_to_udp6_sock:
1756 		return &bpf_skc_to_udp6_sock_proto;
1757 	case BPF_FUNC_sk_storage_get:
1758 		return &bpf_sk_storage_get_tracing_proto;
1759 	case BPF_FUNC_sk_storage_delete:
1760 		return &bpf_sk_storage_delete_tracing_proto;
1761 	case BPF_FUNC_sock_from_file:
1762 		return &bpf_sock_from_file_proto;
1763 #endif
1764 	case BPF_FUNC_seq_printf:
1765 		return prog->expected_attach_type == BPF_TRACE_ITER ?
1766 		       &bpf_seq_printf_proto :
1767 		       NULL;
1768 	case BPF_FUNC_seq_write:
1769 		return prog->expected_attach_type == BPF_TRACE_ITER ?
1770 		       &bpf_seq_write_proto :
1771 		       NULL;
1772 	case BPF_FUNC_seq_printf_btf:
1773 		return prog->expected_attach_type == BPF_TRACE_ITER ?
1774 		       &bpf_seq_printf_btf_proto :
1775 		       NULL;
1776 	case BPF_FUNC_d_path:
1777 		return &bpf_d_path_proto;
1778 	default:
1779 		return raw_tp_prog_func_proto(func_id, prog);
1780 	}
1781 }
1782 
1783 static bool raw_tp_prog_is_valid_access(int off, int size,
1784 					enum bpf_access_type type,
1785 					const struct bpf_prog *prog,
1786 					struct bpf_insn_access_aux *info)
1787 {
1788 	if (off < 0 || off >= sizeof(__u64) * MAX_BPF_FUNC_ARGS)
1789 		return false;
1790 	if (type != BPF_READ)
1791 		return false;
1792 	if (off % size != 0)
1793 		return false;
1794 	return true;
1795 }
1796 
1797 static bool tracing_prog_is_valid_access(int off, int size,
1798 					 enum bpf_access_type type,
1799 					 const struct bpf_prog *prog,
1800 					 struct bpf_insn_access_aux *info)
1801 {
1802 	if (off < 0 || off >= sizeof(__u64) * MAX_BPF_FUNC_ARGS)
1803 		return false;
1804 	if (type != BPF_READ)
1805 		return false;
1806 	if (off % size != 0)
1807 		return false;
1808 	return btf_ctx_access(off, size, type, prog, info);
1809 }
1810 
1811 int __weak bpf_prog_test_run_tracing(struct bpf_prog *prog,
1812 				     const union bpf_attr *kattr,
1813 				     union bpf_attr __user *uattr)
1814 {
1815 	return -ENOTSUPP;
1816 }
1817 
1818 const struct bpf_verifier_ops raw_tracepoint_verifier_ops = {
1819 	.get_func_proto  = raw_tp_prog_func_proto,
1820 	.is_valid_access = raw_tp_prog_is_valid_access,
1821 };
1822 
1823 const struct bpf_prog_ops raw_tracepoint_prog_ops = {
1824 #ifdef CONFIG_NET
1825 	.test_run = bpf_prog_test_run_raw_tp,
1826 #endif
1827 };
1828 
1829 const struct bpf_verifier_ops tracing_verifier_ops = {
1830 	.get_func_proto  = tracing_prog_func_proto,
1831 	.is_valid_access = tracing_prog_is_valid_access,
1832 };
1833 
1834 const struct bpf_prog_ops tracing_prog_ops = {
1835 	.test_run = bpf_prog_test_run_tracing,
1836 };
1837 
1838 static bool raw_tp_writable_prog_is_valid_access(int off, int size,
1839 						 enum bpf_access_type type,
1840 						 const struct bpf_prog *prog,
1841 						 struct bpf_insn_access_aux *info)
1842 {
1843 	if (off == 0) {
1844 		if (size != sizeof(u64) || type != BPF_READ)
1845 			return false;
1846 		info->reg_type = PTR_TO_TP_BUFFER;
1847 	}
1848 	return raw_tp_prog_is_valid_access(off, size, type, prog, info);
1849 }
1850 
1851 const struct bpf_verifier_ops raw_tracepoint_writable_verifier_ops = {
1852 	.get_func_proto  = raw_tp_prog_func_proto,
1853 	.is_valid_access = raw_tp_writable_prog_is_valid_access,
1854 };
1855 
1856 const struct bpf_prog_ops raw_tracepoint_writable_prog_ops = {
1857 };
1858 
1859 static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
1860 				    const struct bpf_prog *prog,
1861 				    struct bpf_insn_access_aux *info)
1862 {
1863 	const int size_u64 = sizeof(u64);
1864 
1865 	if (off < 0 || off >= sizeof(struct bpf_perf_event_data))
1866 		return false;
1867 	if (type != BPF_READ)
1868 		return false;
1869 	if (off % size != 0) {
1870 		if (sizeof(unsigned long) != 4)
1871 			return false;
1872 		if (size != 8)
1873 			return false;
1874 		if (off % size != 4)
1875 			return false;
1876 	}
1877 
1878 	switch (off) {
1879 	case bpf_ctx_range(struct bpf_perf_event_data, sample_period):
1880 		bpf_ctx_record_field_size(info, size_u64);
1881 		if (!bpf_ctx_narrow_access_ok(off, size, size_u64))
1882 			return false;
1883 		break;
1884 	case bpf_ctx_range(struct bpf_perf_event_data, addr):
1885 		bpf_ctx_record_field_size(info, size_u64);
1886 		if (!bpf_ctx_narrow_access_ok(off, size, size_u64))
1887 			return false;
1888 		break;
1889 	default:
1890 		if (size != sizeof(long))
1891 			return false;
1892 	}
1893 
1894 	return true;
1895 }
1896 
1897 static u32 pe_prog_convert_ctx_access(enum bpf_access_type type,
1898 				      const struct bpf_insn *si,
1899 				      struct bpf_insn *insn_buf,
1900 				      struct bpf_prog *prog, u32 *target_size)
1901 {
1902 	struct bpf_insn *insn = insn_buf;
1903 
1904 	switch (si->off) {
1905 	case offsetof(struct bpf_perf_event_data, sample_period):
1906 		*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
1907 						       data), si->dst_reg, si->src_reg,
1908 				      offsetof(struct bpf_perf_event_data_kern, data));
1909 		*insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg,
1910 				      bpf_target_off(struct perf_sample_data, period, 8,
1911 						     target_size));
1912 		break;
1913 	case offsetof(struct bpf_perf_event_data, addr):
1914 		*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
1915 						       data), si->dst_reg, si->src_reg,
1916 				      offsetof(struct bpf_perf_event_data_kern, data));
1917 		*insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg,
1918 				      bpf_target_off(struct perf_sample_data, addr, 8,
1919 						     target_size));
1920 		break;
1921 	default:
1922 		*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
1923 						       regs), si->dst_reg, si->src_reg,
1924 				      offsetof(struct bpf_perf_event_data_kern, regs));
1925 		*insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg,
1926 				      si->off);
1927 		break;
1928 	}
1929 
1930 	return insn - insn_buf;
1931 }
1932 
1933 const struct bpf_verifier_ops perf_event_verifier_ops = {
1934 	.get_func_proto		= pe_prog_func_proto,
1935 	.is_valid_access	= pe_prog_is_valid_access,
1936 	.convert_ctx_access	= pe_prog_convert_ctx_access,
1937 };
1938 
1939 const struct bpf_prog_ops perf_event_prog_ops = {
1940 };
1941 
1942 static DEFINE_MUTEX(bpf_event_mutex);
1943 
1944 #define BPF_TRACE_MAX_PROGS 64
1945 
1946 int perf_event_attach_bpf_prog(struct perf_event *event,
1947 			       struct bpf_prog *prog)
1948 {
1949 	struct bpf_prog_array *old_array;
1950 	struct bpf_prog_array *new_array;
1951 	int ret = -EEXIST;
1952 
1953 	/*
1954 	 * Kprobe override only works if they are on the function entry,
1955 	 * and only if they are on the opt-in list.
1956 	 */
1957 	if (prog->kprobe_override &&
1958 	    (!trace_kprobe_on_func_entry(event->tp_event) ||
1959 	     !trace_kprobe_error_injectable(event->tp_event)))
1960 		return -EINVAL;
1961 
1962 	mutex_lock(&bpf_event_mutex);
1963 
1964 	if (event->prog)
1965 		goto unlock;
1966 
1967 	old_array = bpf_event_rcu_dereference(event->tp_event->prog_array);
1968 	if (old_array &&
1969 	    bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) {
1970 		ret = -E2BIG;
1971 		goto unlock;
1972 	}
1973 
1974 	ret = bpf_prog_array_copy(old_array, NULL, prog, &new_array);
1975 	if (ret < 0)
1976 		goto unlock;
1977 
1978 	/* set the new array to event->tp_event and set event->prog */
1979 	event->prog = prog;
1980 	rcu_assign_pointer(event->tp_event->prog_array, new_array);
1981 	bpf_prog_array_free(old_array);
1982 
1983 unlock:
1984 	mutex_unlock(&bpf_event_mutex);
1985 	return ret;
1986 }
1987 
1988 void perf_event_detach_bpf_prog(struct perf_event *event)
1989 {
1990 	struct bpf_prog_array *old_array;
1991 	struct bpf_prog_array *new_array;
1992 	int ret;
1993 
1994 	mutex_lock(&bpf_event_mutex);
1995 
1996 	if (!event->prog)
1997 		goto unlock;
1998 
1999 	old_array = bpf_event_rcu_dereference(event->tp_event->prog_array);
2000 	ret = bpf_prog_array_copy(old_array, event->prog, NULL, &new_array);
2001 	if (ret == -ENOENT)
2002 		goto unlock;
2003 	if (ret < 0) {
2004 		bpf_prog_array_delete_safe(old_array, event->prog);
2005 	} else {
2006 		rcu_assign_pointer(event->tp_event->prog_array, new_array);
2007 		bpf_prog_array_free(old_array);
2008 	}
2009 
2010 	bpf_prog_put(event->prog);
2011 	event->prog = NULL;
2012 
2013 unlock:
2014 	mutex_unlock(&bpf_event_mutex);
2015 }
2016 
2017 int perf_event_query_prog_array(struct perf_event *event, void __user *info)
2018 {
2019 	struct perf_event_query_bpf __user *uquery = info;
2020 	struct perf_event_query_bpf query = {};
2021 	struct bpf_prog_array *progs;
2022 	u32 *ids, prog_cnt, ids_len;
2023 	int ret;
2024 
2025 	if (!perfmon_capable())
2026 		return -EPERM;
2027 	if (event->attr.type != PERF_TYPE_TRACEPOINT)
2028 		return -EINVAL;
2029 	if (copy_from_user(&query, uquery, sizeof(query)))
2030 		return -EFAULT;
2031 
2032 	ids_len = query.ids_len;
2033 	if (ids_len > BPF_TRACE_MAX_PROGS)
2034 		return -E2BIG;
2035 	ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN);
2036 	if (!ids)
2037 		return -ENOMEM;
2038 	/*
2039 	 * The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which
2040 	 * is required when user only wants to check for uquery->prog_cnt.
2041 	 * There is no need to check for it since the case is handled
2042 	 * gracefully in bpf_prog_array_copy_info.
2043 	 */
2044 
2045 	mutex_lock(&bpf_event_mutex);
2046 	progs = bpf_event_rcu_dereference(event->tp_event->prog_array);
2047 	ret = bpf_prog_array_copy_info(progs, ids, ids_len, &prog_cnt);
2048 	mutex_unlock(&bpf_event_mutex);
2049 
2050 	if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) ||
2051 	    copy_to_user(uquery->ids, ids, ids_len * sizeof(u32)))
2052 		ret = -EFAULT;
2053 
2054 	kfree(ids);
2055 	return ret;
2056 }
2057 
2058 extern struct bpf_raw_event_map __start__bpf_raw_tp[];
2059 extern struct bpf_raw_event_map __stop__bpf_raw_tp[];
2060 
2061 struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name)
2062 {
2063 	struct bpf_raw_event_map *btp = __start__bpf_raw_tp;
2064 
2065 	for (; btp < __stop__bpf_raw_tp; btp++) {
2066 		if (!strcmp(btp->tp->name, name))
2067 			return btp;
2068 	}
2069 
2070 	return bpf_get_raw_tracepoint_module(name);
2071 }
2072 
2073 void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp)
2074 {
2075 	struct module *mod;
2076 
2077 	preempt_disable();
2078 	mod = __module_address((unsigned long)btp);
2079 	module_put(mod);
2080 	preempt_enable();
2081 }
2082 
2083 static __always_inline
2084 void __bpf_trace_run(struct bpf_prog *prog, u64 *args)
2085 {
2086 	cant_sleep();
2087 	rcu_read_lock();
2088 	(void) BPF_PROG_RUN(prog, args);
2089 	rcu_read_unlock();
2090 }
2091 
2092 #define UNPACK(...)			__VA_ARGS__
2093 #define REPEAT_1(FN, DL, X, ...)	FN(X)
2094 #define REPEAT_2(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__)
2095 #define REPEAT_3(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_2(FN, DL, __VA_ARGS__)
2096 #define REPEAT_4(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_3(FN, DL, __VA_ARGS__)
2097 #define REPEAT_5(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_4(FN, DL, __VA_ARGS__)
2098 #define REPEAT_6(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_5(FN, DL, __VA_ARGS__)
2099 #define REPEAT_7(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_6(FN, DL, __VA_ARGS__)
2100 #define REPEAT_8(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_7(FN, DL, __VA_ARGS__)
2101 #define REPEAT_9(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_8(FN, DL, __VA_ARGS__)
2102 #define REPEAT_10(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_9(FN, DL, __VA_ARGS__)
2103 #define REPEAT_11(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_10(FN, DL, __VA_ARGS__)
2104 #define REPEAT_12(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_11(FN, DL, __VA_ARGS__)
2105 #define REPEAT(X, FN, DL, ...)		REPEAT_##X(FN, DL, __VA_ARGS__)
2106 
2107 #define SARG(X)		u64 arg##X
2108 #define COPY(X)		args[X] = arg##X
2109 
2110 #define __DL_COM	(,)
2111 #define __DL_SEM	(;)
2112 
2113 #define __SEQ_0_11	0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11
2114 
2115 #define BPF_TRACE_DEFN_x(x)						\
2116 	void bpf_trace_run##x(struct bpf_prog *prog,			\
2117 			      REPEAT(x, SARG, __DL_COM, __SEQ_0_11))	\
2118 	{								\
2119 		u64 args[x];						\
2120 		REPEAT(x, COPY, __DL_SEM, __SEQ_0_11);			\
2121 		__bpf_trace_run(prog, args);				\
2122 	}								\
2123 	EXPORT_SYMBOL_GPL(bpf_trace_run##x)
2124 BPF_TRACE_DEFN_x(1);
2125 BPF_TRACE_DEFN_x(2);
2126 BPF_TRACE_DEFN_x(3);
2127 BPF_TRACE_DEFN_x(4);
2128 BPF_TRACE_DEFN_x(5);
2129 BPF_TRACE_DEFN_x(6);
2130 BPF_TRACE_DEFN_x(7);
2131 BPF_TRACE_DEFN_x(8);
2132 BPF_TRACE_DEFN_x(9);
2133 BPF_TRACE_DEFN_x(10);
2134 BPF_TRACE_DEFN_x(11);
2135 BPF_TRACE_DEFN_x(12);
2136 
2137 static int __bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog)
2138 {
2139 	struct tracepoint *tp = btp->tp;
2140 
2141 	/*
2142 	 * check that program doesn't access arguments beyond what's
2143 	 * available in this tracepoint
2144 	 */
2145 	if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64))
2146 		return -EINVAL;
2147 
2148 	if (prog->aux->max_tp_access > btp->writable_size)
2149 		return -EINVAL;
2150 
2151 	return tracepoint_probe_register(tp, (void *)btp->bpf_func, prog);
2152 }
2153 
2154 int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog)
2155 {
2156 	return __bpf_probe_register(btp, prog);
2157 }
2158 
2159 int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_prog *prog)
2160 {
2161 	return tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, prog);
2162 }
2163 
2164 int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id,
2165 			    u32 *fd_type, const char **buf,
2166 			    u64 *probe_offset, u64 *probe_addr)
2167 {
2168 	bool is_tracepoint, is_syscall_tp;
2169 	struct bpf_prog *prog;
2170 	int flags, err = 0;
2171 
2172 	prog = event->prog;
2173 	if (!prog)
2174 		return -ENOENT;
2175 
2176 	/* not supporting BPF_PROG_TYPE_PERF_EVENT yet */
2177 	if (prog->type == BPF_PROG_TYPE_PERF_EVENT)
2178 		return -EOPNOTSUPP;
2179 
2180 	*prog_id = prog->aux->id;
2181 	flags = event->tp_event->flags;
2182 	is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT;
2183 	is_syscall_tp = is_syscall_trace_event(event->tp_event);
2184 
2185 	if (is_tracepoint || is_syscall_tp) {
2186 		*buf = is_tracepoint ? event->tp_event->tp->name
2187 				     : event->tp_event->name;
2188 		*fd_type = BPF_FD_TYPE_TRACEPOINT;
2189 		*probe_offset = 0x0;
2190 		*probe_addr = 0x0;
2191 	} else {
2192 		/* kprobe/uprobe */
2193 		err = -EOPNOTSUPP;
2194 #ifdef CONFIG_KPROBE_EVENTS
2195 		if (flags & TRACE_EVENT_FL_KPROBE)
2196 			err = bpf_get_kprobe_info(event, fd_type, buf,
2197 						  probe_offset, probe_addr,
2198 						  event->attr.type == PERF_TYPE_TRACEPOINT);
2199 #endif
2200 #ifdef CONFIG_UPROBE_EVENTS
2201 		if (flags & TRACE_EVENT_FL_UPROBE)
2202 			err = bpf_get_uprobe_info(event, fd_type, buf,
2203 						  probe_offset,
2204 						  event->attr.type == PERF_TYPE_TRACEPOINT);
2205 #endif
2206 	}
2207 
2208 	return err;
2209 }
2210 
2211 static int __init send_signal_irq_work_init(void)
2212 {
2213 	int cpu;
2214 	struct send_signal_irq_work *work;
2215 
2216 	for_each_possible_cpu(cpu) {
2217 		work = per_cpu_ptr(&send_signal_work, cpu);
2218 		init_irq_work(&work->irq_work, do_bpf_send_signal);
2219 	}
2220 	return 0;
2221 }
2222 
2223 subsys_initcall(send_signal_irq_work_init);
2224 
2225 #ifdef CONFIG_MODULES
2226 static int bpf_event_notify(struct notifier_block *nb, unsigned long op,
2227 			    void *module)
2228 {
2229 	struct bpf_trace_module *btm, *tmp;
2230 	struct module *mod = module;
2231 	int ret = 0;
2232 
2233 	if (mod->num_bpf_raw_events == 0 ||
2234 	    (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING))
2235 		goto out;
2236 
2237 	mutex_lock(&bpf_module_mutex);
2238 
2239 	switch (op) {
2240 	case MODULE_STATE_COMING:
2241 		btm = kzalloc(sizeof(*btm), GFP_KERNEL);
2242 		if (btm) {
2243 			btm->module = module;
2244 			list_add(&btm->list, &bpf_trace_modules);
2245 		} else {
2246 			ret = -ENOMEM;
2247 		}
2248 		break;
2249 	case MODULE_STATE_GOING:
2250 		list_for_each_entry_safe(btm, tmp, &bpf_trace_modules, list) {
2251 			if (btm->module == module) {
2252 				list_del(&btm->list);
2253 				kfree(btm);
2254 				break;
2255 			}
2256 		}
2257 		break;
2258 	}
2259 
2260 	mutex_unlock(&bpf_module_mutex);
2261 
2262 out:
2263 	return notifier_from_errno(ret);
2264 }
2265 
2266 static struct notifier_block bpf_module_nb = {
2267 	.notifier_call = bpf_event_notify,
2268 };
2269 
2270 static int __init bpf_event_init(void)
2271 {
2272 	register_module_notifier(&bpf_module_nb);
2273 	return 0;
2274 }
2275 
2276 fs_initcall(bpf_event_init);
2277 #endif /* CONFIG_MODULES */
2278