xref: /linux/kernel/trace/bpf_trace.c (revision c1639be98b4281ac537f2ed77b0afaa1d336ce6c)
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 heurisitc 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 	ret = strncpy_from_user_nofault(dst, unsafe_ptr, size);
188 	if (unlikely(ret < 0))
189 		memset(dst, 0, size);
190 	return ret;
191 }
192 
193 BPF_CALL_3(bpf_probe_read_user_str, void *, dst, u32, size,
194 	   const void __user *, unsafe_ptr)
195 {
196 	return bpf_probe_read_user_str_common(dst, size, unsafe_ptr);
197 }
198 
199 const struct bpf_func_proto bpf_probe_read_user_str_proto = {
200 	.func		= bpf_probe_read_user_str,
201 	.gpl_only	= true,
202 	.ret_type	= RET_INTEGER,
203 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
204 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
205 	.arg3_type	= ARG_ANYTHING,
206 };
207 
208 static __always_inline int
209 bpf_probe_read_kernel_common(void *dst, u32 size, const void *unsafe_ptr)
210 {
211 	int ret = security_locked_down(LOCKDOWN_BPF_READ);
212 
213 	if (unlikely(ret < 0))
214 		goto fail;
215 	ret = copy_from_kernel_nofault(dst, unsafe_ptr, size);
216 	if (unlikely(ret < 0))
217 		goto fail;
218 	return ret;
219 fail:
220 	memset(dst, 0, size);
221 	return ret;
222 }
223 
224 BPF_CALL_3(bpf_probe_read_kernel, void *, dst, u32, size,
225 	   const void *, unsafe_ptr)
226 {
227 	return bpf_probe_read_kernel_common(dst, size, unsafe_ptr);
228 }
229 
230 const struct bpf_func_proto bpf_probe_read_kernel_proto = {
231 	.func		= bpf_probe_read_kernel,
232 	.gpl_only	= true,
233 	.ret_type	= RET_INTEGER,
234 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
235 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
236 	.arg3_type	= ARG_ANYTHING,
237 };
238 
239 static __always_inline int
240 bpf_probe_read_kernel_str_common(void *dst, u32 size, const void *unsafe_ptr)
241 {
242 	int ret = security_locked_down(LOCKDOWN_BPF_READ);
243 
244 	if (unlikely(ret < 0))
245 		goto fail;
246 
247 	/*
248 	 * The strncpy_from_kernel_nofault() call will likely not fill the
249 	 * entire buffer, but that's okay in this circumstance as we're probing
250 	 * arbitrary memory anyway similar to bpf_probe_read_*() and might
251 	 * as well probe the stack. Thus, memory is explicitly cleared
252 	 * only in error case, so that improper users ignoring return
253 	 * code altogether don't copy garbage; otherwise length of string
254 	 * is returned that can be used for bpf_perf_event_output() et al.
255 	 */
256 	ret = strncpy_from_kernel_nofault(dst, unsafe_ptr, size);
257 	if (unlikely(ret < 0))
258 		goto fail;
259 
260 	return ret;
261 fail:
262 	memset(dst, 0, size);
263 	return ret;
264 }
265 
266 BPF_CALL_3(bpf_probe_read_kernel_str, void *, dst, u32, size,
267 	   const void *, unsafe_ptr)
268 {
269 	return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr);
270 }
271 
272 const struct bpf_func_proto bpf_probe_read_kernel_str_proto = {
273 	.func		= bpf_probe_read_kernel_str,
274 	.gpl_only	= true,
275 	.ret_type	= RET_INTEGER,
276 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
277 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
278 	.arg3_type	= ARG_ANYTHING,
279 };
280 
281 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
282 BPF_CALL_3(bpf_probe_read_compat, void *, dst, u32, size,
283 	   const void *, unsafe_ptr)
284 {
285 	if ((unsigned long)unsafe_ptr < TASK_SIZE) {
286 		return bpf_probe_read_user_common(dst, size,
287 				(__force void __user *)unsafe_ptr);
288 	}
289 	return bpf_probe_read_kernel_common(dst, size, unsafe_ptr);
290 }
291 
292 static const struct bpf_func_proto bpf_probe_read_compat_proto = {
293 	.func		= bpf_probe_read_compat,
294 	.gpl_only	= true,
295 	.ret_type	= RET_INTEGER,
296 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
297 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
298 	.arg3_type	= ARG_ANYTHING,
299 };
300 
301 BPF_CALL_3(bpf_probe_read_compat_str, void *, dst, u32, size,
302 	   const void *, unsafe_ptr)
303 {
304 	if ((unsigned long)unsafe_ptr < TASK_SIZE) {
305 		return bpf_probe_read_user_str_common(dst, size,
306 				(__force void __user *)unsafe_ptr);
307 	}
308 	return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr);
309 }
310 
311 static const struct bpf_func_proto bpf_probe_read_compat_str_proto = {
312 	.func		= bpf_probe_read_compat_str,
313 	.gpl_only	= true,
314 	.ret_type	= RET_INTEGER,
315 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
316 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
317 	.arg3_type	= ARG_ANYTHING,
318 };
319 #endif /* CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE */
320 
321 BPF_CALL_3(bpf_probe_write_user, void __user *, unsafe_ptr, const void *, src,
322 	   u32, size)
323 {
324 	/*
325 	 * Ensure we're in user context which is safe for the helper to
326 	 * run. This helper has no business in a kthread.
327 	 *
328 	 * access_ok() should prevent writing to non-user memory, but in
329 	 * some situations (nommu, temporary switch, etc) access_ok() does
330 	 * not provide enough validation, hence the check on KERNEL_DS.
331 	 *
332 	 * nmi_uaccess_okay() ensures the probe is not run in an interim
333 	 * state, when the task or mm are switched. This is specifically
334 	 * required to prevent the use of temporary mm.
335 	 */
336 
337 	if (unlikely(in_interrupt() ||
338 		     current->flags & (PF_KTHREAD | PF_EXITING)))
339 		return -EPERM;
340 	if (unlikely(uaccess_kernel()))
341 		return -EPERM;
342 	if (unlikely(!nmi_uaccess_okay()))
343 		return -EPERM;
344 
345 	return copy_to_user_nofault(unsafe_ptr, src, size);
346 }
347 
348 static const struct bpf_func_proto bpf_probe_write_user_proto = {
349 	.func		= bpf_probe_write_user,
350 	.gpl_only	= true,
351 	.ret_type	= RET_INTEGER,
352 	.arg1_type	= ARG_ANYTHING,
353 	.arg2_type	= ARG_PTR_TO_MEM,
354 	.arg3_type	= ARG_CONST_SIZE,
355 };
356 
357 static const struct bpf_func_proto *bpf_get_probe_write_proto(void)
358 {
359 	if (!capable(CAP_SYS_ADMIN))
360 		return NULL;
361 
362 	pr_warn_ratelimited("%s[%d] is installing a program with bpf_probe_write_user helper that may corrupt user memory!",
363 			    current->comm, task_pid_nr(current));
364 
365 	return &bpf_probe_write_user_proto;
366 }
367 
368 static void bpf_trace_copy_string(char *buf, void *unsafe_ptr, char fmt_ptype,
369 		size_t bufsz)
370 {
371 	void __user *user_ptr = (__force void __user *)unsafe_ptr;
372 
373 	buf[0] = 0;
374 
375 	switch (fmt_ptype) {
376 	case 's':
377 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
378 		if ((unsigned long)unsafe_ptr < TASK_SIZE) {
379 			strncpy_from_user_nofault(buf, user_ptr, bufsz);
380 			break;
381 		}
382 		fallthrough;
383 #endif
384 	case 'k':
385 		strncpy_from_kernel_nofault(buf, unsafe_ptr, bufsz);
386 		break;
387 	case 'u':
388 		strncpy_from_user_nofault(buf, user_ptr, bufsz);
389 		break;
390 	}
391 }
392 
393 static DEFINE_RAW_SPINLOCK(trace_printk_lock);
394 
395 #define BPF_TRACE_PRINTK_SIZE   1024
396 
397 static __printf(1, 0) int bpf_do_trace_printk(const char *fmt, ...)
398 {
399 	static char buf[BPF_TRACE_PRINTK_SIZE];
400 	unsigned long flags;
401 	va_list ap;
402 	int ret;
403 
404 	raw_spin_lock_irqsave(&trace_printk_lock, flags);
405 	va_start(ap, fmt);
406 	ret = vsnprintf(buf, sizeof(buf), fmt, ap);
407 	va_end(ap);
408 	/* vsnprintf() will not append null for zero-length strings */
409 	if (ret == 0)
410 		buf[0] = '\0';
411 	trace_bpf_trace_printk(buf);
412 	raw_spin_unlock_irqrestore(&trace_printk_lock, flags);
413 
414 	return ret;
415 }
416 
417 /*
418  * Only limited trace_printk() conversion specifiers allowed:
419  * %d %i %u %x %ld %li %lu %lx %lld %lli %llu %llx %p %pB %pks %pus %s
420  */
421 BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1,
422 	   u64, arg2, u64, arg3)
423 {
424 	int i, mod[3] = {}, fmt_cnt = 0;
425 	char buf[64], fmt_ptype;
426 	void *unsafe_ptr = NULL;
427 	bool str_seen = false;
428 
429 	/*
430 	 * bpf_check()->check_func_arg()->check_stack_boundary()
431 	 * guarantees that fmt points to bpf program stack,
432 	 * fmt_size bytes of it were initialized and fmt_size > 0
433 	 */
434 	if (fmt[--fmt_size] != 0)
435 		return -EINVAL;
436 
437 	/* check format string for allowed specifiers */
438 	for (i = 0; i < fmt_size; i++) {
439 		if ((!isprint(fmt[i]) && !isspace(fmt[i])) || !isascii(fmt[i]))
440 			return -EINVAL;
441 
442 		if (fmt[i] != '%')
443 			continue;
444 
445 		if (fmt_cnt >= 3)
446 			return -EINVAL;
447 
448 		/* fmt[i] != 0 && fmt[last] == 0, so we can access fmt[i + 1] */
449 		i++;
450 		if (fmt[i] == 'l') {
451 			mod[fmt_cnt]++;
452 			i++;
453 		} else if (fmt[i] == 'p') {
454 			mod[fmt_cnt]++;
455 			if ((fmt[i + 1] == 'k' ||
456 			     fmt[i + 1] == 'u') &&
457 			    fmt[i + 2] == 's') {
458 				fmt_ptype = fmt[i + 1];
459 				i += 2;
460 				goto fmt_str;
461 			}
462 
463 			if (fmt[i + 1] == 'B') {
464 				i++;
465 				goto fmt_next;
466 			}
467 
468 			/* disallow any further format extensions */
469 			if (fmt[i + 1] != 0 &&
470 			    !isspace(fmt[i + 1]) &&
471 			    !ispunct(fmt[i + 1]))
472 				return -EINVAL;
473 
474 			goto fmt_next;
475 		} else if (fmt[i] == 's') {
476 			mod[fmt_cnt]++;
477 			fmt_ptype = fmt[i];
478 fmt_str:
479 			if (str_seen)
480 				/* allow only one '%s' per fmt string */
481 				return -EINVAL;
482 			str_seen = true;
483 
484 			if (fmt[i + 1] != 0 &&
485 			    !isspace(fmt[i + 1]) &&
486 			    !ispunct(fmt[i + 1]))
487 				return -EINVAL;
488 
489 			switch (fmt_cnt) {
490 			case 0:
491 				unsafe_ptr = (void *)(long)arg1;
492 				arg1 = (long)buf;
493 				break;
494 			case 1:
495 				unsafe_ptr = (void *)(long)arg2;
496 				arg2 = (long)buf;
497 				break;
498 			case 2:
499 				unsafe_ptr = (void *)(long)arg3;
500 				arg3 = (long)buf;
501 				break;
502 			}
503 
504 			bpf_trace_copy_string(buf, unsafe_ptr, fmt_ptype,
505 					sizeof(buf));
506 			goto fmt_next;
507 		}
508 
509 		if (fmt[i] == 'l') {
510 			mod[fmt_cnt]++;
511 			i++;
512 		}
513 
514 		if (fmt[i] != 'i' && fmt[i] != 'd' &&
515 		    fmt[i] != 'u' && fmt[i] != 'x')
516 			return -EINVAL;
517 fmt_next:
518 		fmt_cnt++;
519 	}
520 
521 /* Horrid workaround for getting va_list handling working with different
522  * argument type combinations generically for 32 and 64 bit archs.
523  */
524 #define __BPF_TP_EMIT()	__BPF_ARG3_TP()
525 #define __BPF_TP(...)							\
526 	bpf_do_trace_printk(fmt, ##__VA_ARGS__)
527 
528 #define __BPF_ARG1_TP(...)						\
529 	((mod[0] == 2 || (mod[0] == 1 && __BITS_PER_LONG == 64))	\
530 	  ? __BPF_TP(arg1, ##__VA_ARGS__)				\
531 	  : ((mod[0] == 1 || (mod[0] == 0 && __BITS_PER_LONG == 32))	\
532 	      ? __BPF_TP((long)arg1, ##__VA_ARGS__)			\
533 	      : __BPF_TP((u32)arg1, ##__VA_ARGS__)))
534 
535 #define __BPF_ARG2_TP(...)						\
536 	((mod[1] == 2 || (mod[1] == 1 && __BITS_PER_LONG == 64))	\
537 	  ? __BPF_ARG1_TP(arg2, ##__VA_ARGS__)				\
538 	  : ((mod[1] == 1 || (mod[1] == 0 && __BITS_PER_LONG == 32))	\
539 	      ? __BPF_ARG1_TP((long)arg2, ##__VA_ARGS__)		\
540 	      : __BPF_ARG1_TP((u32)arg2, ##__VA_ARGS__)))
541 
542 #define __BPF_ARG3_TP(...)						\
543 	((mod[2] == 2 || (mod[2] == 1 && __BITS_PER_LONG == 64))	\
544 	  ? __BPF_ARG2_TP(arg3, ##__VA_ARGS__)				\
545 	  : ((mod[2] == 1 || (mod[2] == 0 && __BITS_PER_LONG == 32))	\
546 	      ? __BPF_ARG2_TP((long)arg3, ##__VA_ARGS__)		\
547 	      : __BPF_ARG2_TP((u32)arg3, ##__VA_ARGS__)))
548 
549 	return __BPF_TP_EMIT();
550 }
551 
552 static const struct bpf_func_proto bpf_trace_printk_proto = {
553 	.func		= bpf_trace_printk,
554 	.gpl_only	= true,
555 	.ret_type	= RET_INTEGER,
556 	.arg1_type	= ARG_PTR_TO_MEM,
557 	.arg2_type	= ARG_CONST_SIZE,
558 };
559 
560 const struct bpf_func_proto *bpf_get_trace_printk_proto(void)
561 {
562 	/*
563 	 * This program might be calling bpf_trace_printk,
564 	 * so enable the associated bpf_trace/bpf_trace_printk event.
565 	 * Repeat this each time as it is possible a user has
566 	 * disabled bpf_trace_printk events.  By loading a program
567 	 * calling bpf_trace_printk() however the user has expressed
568 	 * the intent to see such events.
569 	 */
570 	if (trace_set_clr_event("bpf_trace", "bpf_trace_printk", 1))
571 		pr_warn_ratelimited("could not enable bpf_trace_printk events");
572 
573 	return &bpf_trace_printk_proto;
574 }
575 
576 #define MAX_SEQ_PRINTF_VARARGS		12
577 #define MAX_SEQ_PRINTF_MAX_MEMCPY	6
578 #define MAX_SEQ_PRINTF_STR_LEN		128
579 
580 struct bpf_seq_printf_buf {
581 	char buf[MAX_SEQ_PRINTF_MAX_MEMCPY][MAX_SEQ_PRINTF_STR_LEN];
582 };
583 static DEFINE_PER_CPU(struct bpf_seq_printf_buf, bpf_seq_printf_buf);
584 static DEFINE_PER_CPU(int, bpf_seq_printf_buf_used);
585 
586 BPF_CALL_5(bpf_seq_printf, struct seq_file *, m, char *, fmt, u32, fmt_size,
587 	   const void *, data, u32, data_len)
588 {
589 	int err = -EINVAL, fmt_cnt = 0, memcpy_cnt = 0;
590 	int i, buf_used, copy_size, num_args;
591 	u64 params[MAX_SEQ_PRINTF_VARARGS];
592 	struct bpf_seq_printf_buf *bufs;
593 	const u64 *args = data;
594 
595 	buf_used = this_cpu_inc_return(bpf_seq_printf_buf_used);
596 	if (WARN_ON_ONCE(buf_used > 1)) {
597 		err = -EBUSY;
598 		goto out;
599 	}
600 
601 	bufs = this_cpu_ptr(&bpf_seq_printf_buf);
602 
603 	/*
604 	 * bpf_check()->check_func_arg()->check_stack_boundary()
605 	 * guarantees that fmt points to bpf program stack,
606 	 * fmt_size bytes of it were initialized and fmt_size > 0
607 	 */
608 	if (fmt[--fmt_size] != 0)
609 		goto out;
610 
611 	if (data_len & 7)
612 		goto out;
613 
614 	for (i = 0; i < fmt_size; i++) {
615 		if (fmt[i] == '%') {
616 			if (fmt[i + 1] == '%')
617 				i++;
618 			else if (!data || !data_len)
619 				goto out;
620 		}
621 	}
622 
623 	num_args = data_len / 8;
624 
625 	/* check format string for allowed specifiers */
626 	for (i = 0; i < fmt_size; i++) {
627 		/* only printable ascii for now. */
628 		if ((!isprint(fmt[i]) && !isspace(fmt[i])) || !isascii(fmt[i])) {
629 			err = -EINVAL;
630 			goto out;
631 		}
632 
633 		if (fmt[i] != '%')
634 			continue;
635 
636 		if (fmt[i + 1] == '%') {
637 			i++;
638 			continue;
639 		}
640 
641 		if (fmt_cnt >= MAX_SEQ_PRINTF_VARARGS) {
642 			err = -E2BIG;
643 			goto out;
644 		}
645 
646 		if (fmt_cnt >= num_args) {
647 			err = -EINVAL;
648 			goto out;
649 		}
650 
651 		/* fmt[i] != 0 && fmt[last] == 0, so we can access fmt[i + 1] */
652 		i++;
653 
654 		/* skip optional "[0 +-][num]" width formating field */
655 		while (fmt[i] == '0' || fmt[i] == '+'  || fmt[i] == '-' ||
656 		       fmt[i] == ' ')
657 			i++;
658 		if (fmt[i] >= '1' && fmt[i] <= '9') {
659 			i++;
660 			while (fmt[i] >= '0' && fmt[i] <= '9')
661 				i++;
662 		}
663 
664 		if (fmt[i] == 's') {
665 			void *unsafe_ptr;
666 
667 			/* try our best to copy */
668 			if (memcpy_cnt >= MAX_SEQ_PRINTF_MAX_MEMCPY) {
669 				err = -E2BIG;
670 				goto out;
671 			}
672 
673 			unsafe_ptr = (void *)(long)args[fmt_cnt];
674 			err = strncpy_from_kernel_nofault(bufs->buf[memcpy_cnt],
675 					unsafe_ptr, MAX_SEQ_PRINTF_STR_LEN);
676 			if (err < 0)
677 				bufs->buf[memcpy_cnt][0] = '\0';
678 			params[fmt_cnt] = (u64)(long)bufs->buf[memcpy_cnt];
679 
680 			fmt_cnt++;
681 			memcpy_cnt++;
682 			continue;
683 		}
684 
685 		if (fmt[i] == 'p') {
686 			if (fmt[i + 1] == 0 ||
687 			    fmt[i + 1] == 'K' ||
688 			    fmt[i + 1] == 'x' ||
689 			    fmt[i + 1] == 'B') {
690 				/* just kernel pointers */
691 				params[fmt_cnt] = args[fmt_cnt];
692 				fmt_cnt++;
693 				continue;
694 			}
695 
696 			/* only support "%pI4", "%pi4", "%pI6" and "%pi6". */
697 			if (fmt[i + 1] != 'i' && fmt[i + 1] != 'I') {
698 				err = -EINVAL;
699 				goto out;
700 			}
701 			if (fmt[i + 2] != '4' && fmt[i + 2] != '6') {
702 				err = -EINVAL;
703 				goto out;
704 			}
705 
706 			if (memcpy_cnt >= MAX_SEQ_PRINTF_MAX_MEMCPY) {
707 				err = -E2BIG;
708 				goto out;
709 			}
710 
711 
712 			copy_size = (fmt[i + 2] == '4') ? 4 : 16;
713 
714 			err = copy_from_kernel_nofault(bufs->buf[memcpy_cnt],
715 						(void *) (long) args[fmt_cnt],
716 						copy_size);
717 			if (err < 0)
718 				memset(bufs->buf[memcpy_cnt], 0, copy_size);
719 			params[fmt_cnt] = (u64)(long)bufs->buf[memcpy_cnt];
720 
721 			i += 2;
722 			fmt_cnt++;
723 			memcpy_cnt++;
724 			continue;
725 		}
726 
727 		if (fmt[i] == 'l') {
728 			i++;
729 			if (fmt[i] == 'l')
730 				i++;
731 		}
732 
733 		if (fmt[i] != 'i' && fmt[i] != 'd' &&
734 		    fmt[i] != 'u' && fmt[i] != 'x' &&
735 		    fmt[i] != 'X') {
736 			err = -EINVAL;
737 			goto out;
738 		}
739 
740 		params[fmt_cnt] = args[fmt_cnt];
741 		fmt_cnt++;
742 	}
743 
744 	/* Maximumly we can have MAX_SEQ_PRINTF_VARARGS parameter, just give
745 	 * all of them to seq_printf().
746 	 */
747 	seq_printf(m, fmt, params[0], params[1], params[2], params[3],
748 		   params[4], params[5], params[6], params[7], params[8],
749 		   params[9], params[10], params[11]);
750 
751 	err = seq_has_overflowed(m) ? -EOVERFLOW : 0;
752 out:
753 	this_cpu_dec(bpf_seq_printf_buf_used);
754 	return err;
755 }
756 
757 BTF_ID_LIST_SINGLE(btf_seq_file_ids, struct, seq_file)
758 
759 static const struct bpf_func_proto bpf_seq_printf_proto = {
760 	.func		= bpf_seq_printf,
761 	.gpl_only	= true,
762 	.ret_type	= RET_INTEGER,
763 	.arg1_type	= ARG_PTR_TO_BTF_ID,
764 	.arg1_btf_id	= &btf_seq_file_ids[0],
765 	.arg2_type	= ARG_PTR_TO_MEM,
766 	.arg3_type	= ARG_CONST_SIZE,
767 	.arg4_type      = ARG_PTR_TO_MEM_OR_NULL,
768 	.arg5_type      = ARG_CONST_SIZE_OR_ZERO,
769 };
770 
771 BPF_CALL_3(bpf_seq_write, struct seq_file *, m, const void *, data, u32, len)
772 {
773 	return seq_write(m, data, len) ? -EOVERFLOW : 0;
774 }
775 
776 static const struct bpf_func_proto bpf_seq_write_proto = {
777 	.func		= bpf_seq_write,
778 	.gpl_only	= true,
779 	.ret_type	= RET_INTEGER,
780 	.arg1_type	= ARG_PTR_TO_BTF_ID,
781 	.arg1_btf_id	= &btf_seq_file_ids[0],
782 	.arg2_type	= ARG_PTR_TO_MEM,
783 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
784 };
785 
786 BPF_CALL_4(bpf_seq_printf_btf, struct seq_file *, m, struct btf_ptr *, ptr,
787 	   u32, btf_ptr_size, u64, flags)
788 {
789 	const struct btf *btf;
790 	s32 btf_id;
791 	int ret;
792 
793 	ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id);
794 	if (ret)
795 		return ret;
796 
797 	return btf_type_seq_show_flags(btf, btf_id, ptr->ptr, m, flags);
798 }
799 
800 static const struct bpf_func_proto bpf_seq_printf_btf_proto = {
801 	.func		= bpf_seq_printf_btf,
802 	.gpl_only	= true,
803 	.ret_type	= RET_INTEGER,
804 	.arg1_type	= ARG_PTR_TO_BTF_ID,
805 	.arg1_btf_id	= &btf_seq_file_ids[0],
806 	.arg2_type	= ARG_PTR_TO_MEM,
807 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
808 	.arg4_type	= ARG_ANYTHING,
809 };
810 
811 static __always_inline int
812 get_map_perf_counter(struct bpf_map *map, u64 flags,
813 		     u64 *value, u64 *enabled, u64 *running)
814 {
815 	struct bpf_array *array = container_of(map, struct bpf_array, map);
816 	unsigned int cpu = smp_processor_id();
817 	u64 index = flags & BPF_F_INDEX_MASK;
818 	struct bpf_event_entry *ee;
819 
820 	if (unlikely(flags & ~(BPF_F_INDEX_MASK)))
821 		return -EINVAL;
822 	if (index == BPF_F_CURRENT_CPU)
823 		index = cpu;
824 	if (unlikely(index >= array->map.max_entries))
825 		return -E2BIG;
826 
827 	ee = READ_ONCE(array->ptrs[index]);
828 	if (!ee)
829 		return -ENOENT;
830 
831 	return perf_event_read_local(ee->event, value, enabled, running);
832 }
833 
834 BPF_CALL_2(bpf_perf_event_read, struct bpf_map *, map, u64, flags)
835 {
836 	u64 value = 0;
837 	int err;
838 
839 	err = get_map_perf_counter(map, flags, &value, NULL, NULL);
840 	/*
841 	 * this api is ugly since we miss [-22..-2] range of valid
842 	 * counter values, but that's uapi
843 	 */
844 	if (err)
845 		return err;
846 	return value;
847 }
848 
849 static const struct bpf_func_proto bpf_perf_event_read_proto = {
850 	.func		= bpf_perf_event_read,
851 	.gpl_only	= true,
852 	.ret_type	= RET_INTEGER,
853 	.arg1_type	= ARG_CONST_MAP_PTR,
854 	.arg2_type	= ARG_ANYTHING,
855 };
856 
857 BPF_CALL_4(bpf_perf_event_read_value, struct bpf_map *, map, u64, flags,
858 	   struct bpf_perf_event_value *, buf, u32, size)
859 {
860 	int err = -EINVAL;
861 
862 	if (unlikely(size != sizeof(struct bpf_perf_event_value)))
863 		goto clear;
864 	err = get_map_perf_counter(map, flags, &buf->counter, &buf->enabled,
865 				   &buf->running);
866 	if (unlikely(err))
867 		goto clear;
868 	return 0;
869 clear:
870 	memset(buf, 0, size);
871 	return err;
872 }
873 
874 static const struct bpf_func_proto bpf_perf_event_read_value_proto = {
875 	.func		= bpf_perf_event_read_value,
876 	.gpl_only	= true,
877 	.ret_type	= RET_INTEGER,
878 	.arg1_type	= ARG_CONST_MAP_PTR,
879 	.arg2_type	= ARG_ANYTHING,
880 	.arg3_type	= ARG_PTR_TO_UNINIT_MEM,
881 	.arg4_type	= ARG_CONST_SIZE,
882 };
883 
884 static __always_inline u64
885 __bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map,
886 			u64 flags, struct perf_sample_data *sd)
887 {
888 	struct bpf_array *array = container_of(map, struct bpf_array, map);
889 	unsigned int cpu = smp_processor_id();
890 	u64 index = flags & BPF_F_INDEX_MASK;
891 	struct bpf_event_entry *ee;
892 	struct perf_event *event;
893 
894 	if (index == BPF_F_CURRENT_CPU)
895 		index = cpu;
896 	if (unlikely(index >= array->map.max_entries))
897 		return -E2BIG;
898 
899 	ee = READ_ONCE(array->ptrs[index]);
900 	if (!ee)
901 		return -ENOENT;
902 
903 	event = ee->event;
904 	if (unlikely(event->attr.type != PERF_TYPE_SOFTWARE ||
905 		     event->attr.config != PERF_COUNT_SW_BPF_OUTPUT))
906 		return -EINVAL;
907 
908 	if (unlikely(event->oncpu != cpu))
909 		return -EOPNOTSUPP;
910 
911 	return perf_event_output(event, sd, regs);
912 }
913 
914 /*
915  * Support executing tracepoints in normal, irq, and nmi context that each call
916  * bpf_perf_event_output
917  */
918 struct bpf_trace_sample_data {
919 	struct perf_sample_data sds[3];
920 };
921 
922 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_trace_sds);
923 static DEFINE_PER_CPU(int, bpf_trace_nest_level);
924 BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map,
925 	   u64, flags, void *, data, u64, size)
926 {
927 	struct bpf_trace_sample_data *sds = this_cpu_ptr(&bpf_trace_sds);
928 	int nest_level = this_cpu_inc_return(bpf_trace_nest_level);
929 	struct perf_raw_record raw = {
930 		.frag = {
931 			.size = size,
932 			.data = data,
933 		},
934 	};
935 	struct perf_sample_data *sd;
936 	int err;
937 
938 	if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(sds->sds))) {
939 		err = -EBUSY;
940 		goto out;
941 	}
942 
943 	sd = &sds->sds[nest_level - 1];
944 
945 	if (unlikely(flags & ~(BPF_F_INDEX_MASK))) {
946 		err = -EINVAL;
947 		goto out;
948 	}
949 
950 	perf_sample_data_init(sd, 0, 0);
951 	sd->raw = &raw;
952 
953 	err = __bpf_perf_event_output(regs, map, flags, sd);
954 
955 out:
956 	this_cpu_dec(bpf_trace_nest_level);
957 	return err;
958 }
959 
960 static const struct bpf_func_proto bpf_perf_event_output_proto = {
961 	.func		= bpf_perf_event_output,
962 	.gpl_only	= true,
963 	.ret_type	= RET_INTEGER,
964 	.arg1_type	= ARG_PTR_TO_CTX,
965 	.arg2_type	= ARG_CONST_MAP_PTR,
966 	.arg3_type	= ARG_ANYTHING,
967 	.arg4_type	= ARG_PTR_TO_MEM,
968 	.arg5_type	= ARG_CONST_SIZE_OR_ZERO,
969 };
970 
971 static DEFINE_PER_CPU(int, bpf_event_output_nest_level);
972 struct bpf_nested_pt_regs {
973 	struct pt_regs regs[3];
974 };
975 static DEFINE_PER_CPU(struct bpf_nested_pt_regs, bpf_pt_regs);
976 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_misc_sds);
977 
978 u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
979 		     void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy)
980 {
981 	int nest_level = this_cpu_inc_return(bpf_event_output_nest_level);
982 	struct perf_raw_frag frag = {
983 		.copy		= ctx_copy,
984 		.size		= ctx_size,
985 		.data		= ctx,
986 	};
987 	struct perf_raw_record raw = {
988 		.frag = {
989 			{
990 				.next	= ctx_size ? &frag : NULL,
991 			},
992 			.size	= meta_size,
993 			.data	= meta,
994 		},
995 	};
996 	struct perf_sample_data *sd;
997 	struct pt_regs *regs;
998 	u64 ret;
999 
1000 	if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(bpf_misc_sds.sds))) {
1001 		ret = -EBUSY;
1002 		goto out;
1003 	}
1004 	sd = this_cpu_ptr(&bpf_misc_sds.sds[nest_level - 1]);
1005 	regs = this_cpu_ptr(&bpf_pt_regs.regs[nest_level - 1]);
1006 
1007 	perf_fetch_caller_regs(regs);
1008 	perf_sample_data_init(sd, 0, 0);
1009 	sd->raw = &raw;
1010 
1011 	ret = __bpf_perf_event_output(regs, map, flags, sd);
1012 out:
1013 	this_cpu_dec(bpf_event_output_nest_level);
1014 	return ret;
1015 }
1016 
1017 BPF_CALL_0(bpf_get_current_task)
1018 {
1019 	return (long) current;
1020 }
1021 
1022 const struct bpf_func_proto bpf_get_current_task_proto = {
1023 	.func		= bpf_get_current_task,
1024 	.gpl_only	= true,
1025 	.ret_type	= RET_INTEGER,
1026 };
1027 
1028 BPF_CALL_0(bpf_get_current_task_btf)
1029 {
1030 	return (unsigned long) current;
1031 }
1032 
1033 BTF_ID_LIST_SINGLE(bpf_get_current_btf_ids, struct, task_struct)
1034 
1035 static const struct bpf_func_proto bpf_get_current_task_btf_proto = {
1036 	.func		= bpf_get_current_task_btf,
1037 	.gpl_only	= true,
1038 	.ret_type	= RET_PTR_TO_BTF_ID,
1039 	.ret_btf_id	= &bpf_get_current_btf_ids[0],
1040 };
1041 
1042 BPF_CALL_2(bpf_current_task_under_cgroup, struct bpf_map *, map, u32, idx)
1043 {
1044 	struct bpf_array *array = container_of(map, struct bpf_array, map);
1045 	struct cgroup *cgrp;
1046 
1047 	if (unlikely(idx >= array->map.max_entries))
1048 		return -E2BIG;
1049 
1050 	cgrp = READ_ONCE(array->ptrs[idx]);
1051 	if (unlikely(!cgrp))
1052 		return -EAGAIN;
1053 
1054 	return task_under_cgroup_hierarchy(current, cgrp);
1055 }
1056 
1057 static const struct bpf_func_proto bpf_current_task_under_cgroup_proto = {
1058 	.func           = bpf_current_task_under_cgroup,
1059 	.gpl_only       = false,
1060 	.ret_type       = RET_INTEGER,
1061 	.arg1_type      = ARG_CONST_MAP_PTR,
1062 	.arg2_type      = ARG_ANYTHING,
1063 };
1064 
1065 struct send_signal_irq_work {
1066 	struct irq_work irq_work;
1067 	struct task_struct *task;
1068 	u32 sig;
1069 	enum pid_type type;
1070 };
1071 
1072 static DEFINE_PER_CPU(struct send_signal_irq_work, send_signal_work);
1073 
1074 static void do_bpf_send_signal(struct irq_work *entry)
1075 {
1076 	struct send_signal_irq_work *work;
1077 
1078 	work = container_of(entry, struct send_signal_irq_work, irq_work);
1079 	group_send_sig_info(work->sig, SEND_SIG_PRIV, work->task, work->type);
1080 }
1081 
1082 static int bpf_send_signal_common(u32 sig, enum pid_type type)
1083 {
1084 	struct send_signal_irq_work *work = NULL;
1085 
1086 	/* Similar to bpf_probe_write_user, task needs to be
1087 	 * in a sound condition and kernel memory access be
1088 	 * permitted in order to send signal to the current
1089 	 * task.
1090 	 */
1091 	if (unlikely(current->flags & (PF_KTHREAD | PF_EXITING)))
1092 		return -EPERM;
1093 	if (unlikely(uaccess_kernel()))
1094 		return -EPERM;
1095 	if (unlikely(!nmi_uaccess_okay()))
1096 		return -EPERM;
1097 
1098 	if (irqs_disabled()) {
1099 		/* Do an early check on signal validity. Otherwise,
1100 		 * the error is lost in deferred irq_work.
1101 		 */
1102 		if (unlikely(!valid_signal(sig)))
1103 			return -EINVAL;
1104 
1105 		work = this_cpu_ptr(&send_signal_work);
1106 		if (atomic_read(&work->irq_work.flags) & IRQ_WORK_BUSY)
1107 			return -EBUSY;
1108 
1109 		/* Add the current task, which is the target of sending signal,
1110 		 * to the irq_work. The current task may change when queued
1111 		 * irq works get executed.
1112 		 */
1113 		work->task = current;
1114 		work->sig = sig;
1115 		work->type = type;
1116 		irq_work_queue(&work->irq_work);
1117 		return 0;
1118 	}
1119 
1120 	return group_send_sig_info(sig, SEND_SIG_PRIV, current, type);
1121 }
1122 
1123 BPF_CALL_1(bpf_send_signal, u32, sig)
1124 {
1125 	return bpf_send_signal_common(sig, PIDTYPE_TGID);
1126 }
1127 
1128 static const struct bpf_func_proto bpf_send_signal_proto = {
1129 	.func		= bpf_send_signal,
1130 	.gpl_only	= false,
1131 	.ret_type	= RET_INTEGER,
1132 	.arg1_type	= ARG_ANYTHING,
1133 };
1134 
1135 BPF_CALL_1(bpf_send_signal_thread, u32, sig)
1136 {
1137 	return bpf_send_signal_common(sig, PIDTYPE_PID);
1138 }
1139 
1140 static const struct bpf_func_proto bpf_send_signal_thread_proto = {
1141 	.func		= bpf_send_signal_thread,
1142 	.gpl_only	= false,
1143 	.ret_type	= RET_INTEGER,
1144 	.arg1_type	= ARG_ANYTHING,
1145 };
1146 
1147 BPF_CALL_3(bpf_d_path, struct path *, path, char *, buf, u32, sz)
1148 {
1149 	long len;
1150 	char *p;
1151 
1152 	if (!sz)
1153 		return 0;
1154 
1155 	p = d_path(path, buf, sz);
1156 	if (IS_ERR(p)) {
1157 		len = PTR_ERR(p);
1158 	} else {
1159 		len = buf + sz - p;
1160 		memmove(buf, p, len);
1161 	}
1162 
1163 	return len;
1164 }
1165 
1166 BTF_SET_START(btf_allowlist_d_path)
1167 #ifdef CONFIG_SECURITY
1168 BTF_ID(func, security_file_permission)
1169 BTF_ID(func, security_inode_getattr)
1170 BTF_ID(func, security_file_open)
1171 #endif
1172 #ifdef CONFIG_SECURITY_PATH
1173 BTF_ID(func, security_path_truncate)
1174 #endif
1175 BTF_ID(func, vfs_truncate)
1176 BTF_ID(func, vfs_fallocate)
1177 BTF_ID(func, dentry_open)
1178 BTF_ID(func, vfs_getattr)
1179 BTF_ID(func, filp_close)
1180 BTF_SET_END(btf_allowlist_d_path)
1181 
1182 static bool bpf_d_path_allowed(const struct bpf_prog *prog)
1183 {
1184 	if (prog->type == BPF_PROG_TYPE_LSM)
1185 		return bpf_lsm_is_sleepable_hook(prog->aux->attach_btf_id);
1186 
1187 	return btf_id_set_contains(&btf_allowlist_d_path,
1188 				   prog->aux->attach_btf_id);
1189 }
1190 
1191 BTF_ID_LIST_SINGLE(bpf_d_path_btf_ids, struct, path)
1192 
1193 static const struct bpf_func_proto bpf_d_path_proto = {
1194 	.func		= bpf_d_path,
1195 	.gpl_only	= false,
1196 	.ret_type	= RET_INTEGER,
1197 	.arg1_type	= ARG_PTR_TO_BTF_ID,
1198 	.arg1_btf_id	= &bpf_d_path_btf_ids[0],
1199 	.arg2_type	= ARG_PTR_TO_MEM,
1200 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
1201 	.allowed	= bpf_d_path_allowed,
1202 };
1203 
1204 #define BTF_F_ALL	(BTF_F_COMPACT  | BTF_F_NONAME | \
1205 			 BTF_F_PTR_RAW | BTF_F_ZERO)
1206 
1207 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size,
1208 				  u64 flags, const struct btf **btf,
1209 				  s32 *btf_id)
1210 {
1211 	const struct btf_type *t;
1212 
1213 	if (unlikely(flags & ~(BTF_F_ALL)))
1214 		return -EINVAL;
1215 
1216 	if (btf_ptr_size != sizeof(struct btf_ptr))
1217 		return -EINVAL;
1218 
1219 	*btf = bpf_get_btf_vmlinux();
1220 
1221 	if (IS_ERR_OR_NULL(*btf))
1222 		return PTR_ERR(*btf);
1223 
1224 	if (ptr->type_id > 0)
1225 		*btf_id = ptr->type_id;
1226 	else
1227 		return -EINVAL;
1228 
1229 	if (*btf_id > 0)
1230 		t = btf_type_by_id(*btf, *btf_id);
1231 	if (*btf_id <= 0 || !t)
1232 		return -ENOENT;
1233 
1234 	return 0;
1235 }
1236 
1237 BPF_CALL_5(bpf_snprintf_btf, char *, str, u32, str_size, struct btf_ptr *, ptr,
1238 	   u32, btf_ptr_size, u64, flags)
1239 {
1240 	const struct btf *btf;
1241 	s32 btf_id;
1242 	int ret;
1243 
1244 	ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id);
1245 	if (ret)
1246 		return ret;
1247 
1248 	return btf_type_snprintf_show(btf, btf_id, ptr->ptr, str, str_size,
1249 				      flags);
1250 }
1251 
1252 const struct bpf_func_proto bpf_snprintf_btf_proto = {
1253 	.func		= bpf_snprintf_btf,
1254 	.gpl_only	= false,
1255 	.ret_type	= RET_INTEGER,
1256 	.arg1_type	= ARG_PTR_TO_MEM,
1257 	.arg2_type	= ARG_CONST_SIZE,
1258 	.arg3_type	= ARG_PTR_TO_MEM,
1259 	.arg4_type	= ARG_CONST_SIZE,
1260 	.arg5_type	= ARG_ANYTHING,
1261 };
1262 
1263 const struct bpf_func_proto *
1264 bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1265 {
1266 	switch (func_id) {
1267 	case BPF_FUNC_map_lookup_elem:
1268 		return &bpf_map_lookup_elem_proto;
1269 	case BPF_FUNC_map_update_elem:
1270 		return &bpf_map_update_elem_proto;
1271 	case BPF_FUNC_map_delete_elem:
1272 		return &bpf_map_delete_elem_proto;
1273 	case BPF_FUNC_map_push_elem:
1274 		return &bpf_map_push_elem_proto;
1275 	case BPF_FUNC_map_pop_elem:
1276 		return &bpf_map_pop_elem_proto;
1277 	case BPF_FUNC_map_peek_elem:
1278 		return &bpf_map_peek_elem_proto;
1279 	case BPF_FUNC_ktime_get_ns:
1280 		return &bpf_ktime_get_ns_proto;
1281 	case BPF_FUNC_ktime_get_boot_ns:
1282 		return &bpf_ktime_get_boot_ns_proto;
1283 	case BPF_FUNC_tail_call:
1284 		return &bpf_tail_call_proto;
1285 	case BPF_FUNC_get_current_pid_tgid:
1286 		return &bpf_get_current_pid_tgid_proto;
1287 	case BPF_FUNC_get_current_task:
1288 		return &bpf_get_current_task_proto;
1289 	case BPF_FUNC_get_current_task_btf:
1290 		return &bpf_get_current_task_btf_proto;
1291 	case BPF_FUNC_get_current_uid_gid:
1292 		return &bpf_get_current_uid_gid_proto;
1293 	case BPF_FUNC_get_current_comm:
1294 		return &bpf_get_current_comm_proto;
1295 	case BPF_FUNC_trace_printk:
1296 		return bpf_get_trace_printk_proto();
1297 	case BPF_FUNC_get_smp_processor_id:
1298 		return &bpf_get_smp_processor_id_proto;
1299 	case BPF_FUNC_get_numa_node_id:
1300 		return &bpf_get_numa_node_id_proto;
1301 	case BPF_FUNC_perf_event_read:
1302 		return &bpf_perf_event_read_proto;
1303 	case BPF_FUNC_probe_write_user:
1304 		return bpf_get_probe_write_proto();
1305 	case BPF_FUNC_current_task_under_cgroup:
1306 		return &bpf_current_task_under_cgroup_proto;
1307 	case BPF_FUNC_get_prandom_u32:
1308 		return &bpf_get_prandom_u32_proto;
1309 	case BPF_FUNC_probe_read_user:
1310 		return &bpf_probe_read_user_proto;
1311 	case BPF_FUNC_probe_read_kernel:
1312 		return &bpf_probe_read_kernel_proto;
1313 	case BPF_FUNC_probe_read_user_str:
1314 		return &bpf_probe_read_user_str_proto;
1315 	case BPF_FUNC_probe_read_kernel_str:
1316 		return &bpf_probe_read_kernel_str_proto;
1317 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
1318 	case BPF_FUNC_probe_read:
1319 		return &bpf_probe_read_compat_proto;
1320 	case BPF_FUNC_probe_read_str:
1321 		return &bpf_probe_read_compat_str_proto;
1322 #endif
1323 #ifdef CONFIG_CGROUPS
1324 	case BPF_FUNC_get_current_cgroup_id:
1325 		return &bpf_get_current_cgroup_id_proto;
1326 #endif
1327 	case BPF_FUNC_send_signal:
1328 		return &bpf_send_signal_proto;
1329 	case BPF_FUNC_send_signal_thread:
1330 		return &bpf_send_signal_thread_proto;
1331 	case BPF_FUNC_perf_event_read_value:
1332 		return &bpf_perf_event_read_value_proto;
1333 	case BPF_FUNC_get_ns_current_pid_tgid:
1334 		return &bpf_get_ns_current_pid_tgid_proto;
1335 	case BPF_FUNC_ringbuf_output:
1336 		return &bpf_ringbuf_output_proto;
1337 	case BPF_FUNC_ringbuf_reserve:
1338 		return &bpf_ringbuf_reserve_proto;
1339 	case BPF_FUNC_ringbuf_submit:
1340 		return &bpf_ringbuf_submit_proto;
1341 	case BPF_FUNC_ringbuf_discard:
1342 		return &bpf_ringbuf_discard_proto;
1343 	case BPF_FUNC_ringbuf_query:
1344 		return &bpf_ringbuf_query_proto;
1345 	case BPF_FUNC_jiffies64:
1346 		return &bpf_jiffies64_proto;
1347 	case BPF_FUNC_get_task_stack:
1348 		return &bpf_get_task_stack_proto;
1349 	case BPF_FUNC_copy_from_user:
1350 		return prog->aux->sleepable ? &bpf_copy_from_user_proto : NULL;
1351 	case BPF_FUNC_snprintf_btf:
1352 		return &bpf_snprintf_btf_proto;
1353 	case BPF_FUNC_bpf_per_cpu_ptr:
1354 		return &bpf_per_cpu_ptr_proto;
1355 	case BPF_FUNC_bpf_this_cpu_ptr:
1356 		return &bpf_this_cpu_ptr_proto;
1357 	default:
1358 		return NULL;
1359 	}
1360 }
1361 
1362 static const struct bpf_func_proto *
1363 kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1364 {
1365 	switch (func_id) {
1366 	case BPF_FUNC_perf_event_output:
1367 		return &bpf_perf_event_output_proto;
1368 	case BPF_FUNC_get_stackid:
1369 		return &bpf_get_stackid_proto;
1370 	case BPF_FUNC_get_stack:
1371 		return &bpf_get_stack_proto;
1372 #ifdef CONFIG_BPF_KPROBE_OVERRIDE
1373 	case BPF_FUNC_override_return:
1374 		return &bpf_override_return_proto;
1375 #endif
1376 	default:
1377 		return bpf_tracing_func_proto(func_id, prog);
1378 	}
1379 }
1380 
1381 /* bpf+kprobe programs can access fields of 'struct pt_regs' */
1382 static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
1383 					const struct bpf_prog *prog,
1384 					struct bpf_insn_access_aux *info)
1385 {
1386 	if (off < 0 || off >= sizeof(struct pt_regs))
1387 		return false;
1388 	if (type != BPF_READ)
1389 		return false;
1390 	if (off % size != 0)
1391 		return false;
1392 	/*
1393 	 * Assertion for 32 bit to make sure last 8 byte access
1394 	 * (BPF_DW) to the last 4 byte member is disallowed.
1395 	 */
1396 	if (off + size > sizeof(struct pt_regs))
1397 		return false;
1398 
1399 	return true;
1400 }
1401 
1402 const struct bpf_verifier_ops kprobe_verifier_ops = {
1403 	.get_func_proto  = kprobe_prog_func_proto,
1404 	.is_valid_access = kprobe_prog_is_valid_access,
1405 };
1406 
1407 const struct bpf_prog_ops kprobe_prog_ops = {
1408 };
1409 
1410 BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map,
1411 	   u64, flags, void *, data, u64, size)
1412 {
1413 	struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1414 
1415 	/*
1416 	 * r1 points to perf tracepoint buffer where first 8 bytes are hidden
1417 	 * from bpf program and contain a pointer to 'struct pt_regs'. Fetch it
1418 	 * from there and call the same bpf_perf_event_output() helper inline.
1419 	 */
1420 	return ____bpf_perf_event_output(regs, map, flags, data, size);
1421 }
1422 
1423 static const struct bpf_func_proto bpf_perf_event_output_proto_tp = {
1424 	.func		= bpf_perf_event_output_tp,
1425 	.gpl_only	= true,
1426 	.ret_type	= RET_INTEGER,
1427 	.arg1_type	= ARG_PTR_TO_CTX,
1428 	.arg2_type	= ARG_CONST_MAP_PTR,
1429 	.arg3_type	= ARG_ANYTHING,
1430 	.arg4_type	= ARG_PTR_TO_MEM,
1431 	.arg5_type	= ARG_CONST_SIZE_OR_ZERO,
1432 };
1433 
1434 BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map,
1435 	   u64, flags)
1436 {
1437 	struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1438 
1439 	/*
1440 	 * Same comment as in bpf_perf_event_output_tp(), only that this time
1441 	 * the other helper's function body cannot be inlined due to being
1442 	 * external, thus we need to call raw helper function.
1443 	 */
1444 	return bpf_get_stackid((unsigned long) regs, (unsigned long) map,
1445 			       flags, 0, 0);
1446 }
1447 
1448 static const struct bpf_func_proto bpf_get_stackid_proto_tp = {
1449 	.func		= bpf_get_stackid_tp,
1450 	.gpl_only	= true,
1451 	.ret_type	= RET_INTEGER,
1452 	.arg1_type	= ARG_PTR_TO_CTX,
1453 	.arg2_type	= ARG_CONST_MAP_PTR,
1454 	.arg3_type	= ARG_ANYTHING,
1455 };
1456 
1457 BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size,
1458 	   u64, flags)
1459 {
1460 	struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1461 
1462 	return bpf_get_stack((unsigned long) regs, (unsigned long) buf,
1463 			     (unsigned long) size, flags, 0);
1464 }
1465 
1466 static const struct bpf_func_proto bpf_get_stack_proto_tp = {
1467 	.func		= bpf_get_stack_tp,
1468 	.gpl_only	= true,
1469 	.ret_type	= RET_INTEGER,
1470 	.arg1_type	= ARG_PTR_TO_CTX,
1471 	.arg2_type	= ARG_PTR_TO_UNINIT_MEM,
1472 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
1473 	.arg4_type	= ARG_ANYTHING,
1474 };
1475 
1476 static const struct bpf_func_proto *
1477 tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1478 {
1479 	switch (func_id) {
1480 	case BPF_FUNC_perf_event_output:
1481 		return &bpf_perf_event_output_proto_tp;
1482 	case BPF_FUNC_get_stackid:
1483 		return &bpf_get_stackid_proto_tp;
1484 	case BPF_FUNC_get_stack:
1485 		return &bpf_get_stack_proto_tp;
1486 	default:
1487 		return bpf_tracing_func_proto(func_id, prog);
1488 	}
1489 }
1490 
1491 static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type,
1492 				    const struct bpf_prog *prog,
1493 				    struct bpf_insn_access_aux *info)
1494 {
1495 	if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE)
1496 		return false;
1497 	if (type != BPF_READ)
1498 		return false;
1499 	if (off % size != 0)
1500 		return false;
1501 
1502 	BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(__u64));
1503 	return true;
1504 }
1505 
1506 const struct bpf_verifier_ops tracepoint_verifier_ops = {
1507 	.get_func_proto  = tp_prog_func_proto,
1508 	.is_valid_access = tp_prog_is_valid_access,
1509 };
1510 
1511 const struct bpf_prog_ops tracepoint_prog_ops = {
1512 };
1513 
1514 BPF_CALL_3(bpf_perf_prog_read_value, struct bpf_perf_event_data_kern *, ctx,
1515 	   struct bpf_perf_event_value *, buf, u32, size)
1516 {
1517 	int err = -EINVAL;
1518 
1519 	if (unlikely(size != sizeof(struct bpf_perf_event_value)))
1520 		goto clear;
1521 	err = perf_event_read_local(ctx->event, &buf->counter, &buf->enabled,
1522 				    &buf->running);
1523 	if (unlikely(err))
1524 		goto clear;
1525 	return 0;
1526 clear:
1527 	memset(buf, 0, size);
1528 	return err;
1529 }
1530 
1531 static const struct bpf_func_proto bpf_perf_prog_read_value_proto = {
1532          .func           = bpf_perf_prog_read_value,
1533          .gpl_only       = true,
1534          .ret_type       = RET_INTEGER,
1535          .arg1_type      = ARG_PTR_TO_CTX,
1536          .arg2_type      = ARG_PTR_TO_UNINIT_MEM,
1537          .arg3_type      = ARG_CONST_SIZE,
1538 };
1539 
1540 BPF_CALL_4(bpf_read_branch_records, struct bpf_perf_event_data_kern *, ctx,
1541 	   void *, buf, u32, size, u64, flags)
1542 {
1543 #ifndef CONFIG_X86
1544 	return -ENOENT;
1545 #else
1546 	static const u32 br_entry_size = sizeof(struct perf_branch_entry);
1547 	struct perf_branch_stack *br_stack = ctx->data->br_stack;
1548 	u32 to_copy;
1549 
1550 	if (unlikely(flags & ~BPF_F_GET_BRANCH_RECORDS_SIZE))
1551 		return -EINVAL;
1552 
1553 	if (unlikely(!br_stack))
1554 		return -EINVAL;
1555 
1556 	if (flags & BPF_F_GET_BRANCH_RECORDS_SIZE)
1557 		return br_stack->nr * br_entry_size;
1558 
1559 	if (!buf || (size % br_entry_size != 0))
1560 		return -EINVAL;
1561 
1562 	to_copy = min_t(u32, br_stack->nr * br_entry_size, size);
1563 	memcpy(buf, br_stack->entries, to_copy);
1564 
1565 	return to_copy;
1566 #endif
1567 }
1568 
1569 static const struct bpf_func_proto bpf_read_branch_records_proto = {
1570 	.func           = bpf_read_branch_records,
1571 	.gpl_only       = true,
1572 	.ret_type       = RET_INTEGER,
1573 	.arg1_type      = ARG_PTR_TO_CTX,
1574 	.arg2_type      = ARG_PTR_TO_MEM_OR_NULL,
1575 	.arg3_type      = ARG_CONST_SIZE_OR_ZERO,
1576 	.arg4_type      = ARG_ANYTHING,
1577 };
1578 
1579 static const struct bpf_func_proto *
1580 pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1581 {
1582 	switch (func_id) {
1583 	case BPF_FUNC_perf_event_output:
1584 		return &bpf_perf_event_output_proto_tp;
1585 	case BPF_FUNC_get_stackid:
1586 		return &bpf_get_stackid_proto_pe;
1587 	case BPF_FUNC_get_stack:
1588 		return &bpf_get_stack_proto_pe;
1589 	case BPF_FUNC_perf_prog_read_value:
1590 		return &bpf_perf_prog_read_value_proto;
1591 	case BPF_FUNC_read_branch_records:
1592 		return &bpf_read_branch_records_proto;
1593 	default:
1594 		return bpf_tracing_func_proto(func_id, prog);
1595 	}
1596 }
1597 
1598 /*
1599  * bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp
1600  * to avoid potential recursive reuse issue when/if tracepoints are added
1601  * inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack.
1602  *
1603  * Since raw tracepoints run despite bpf_prog_active, support concurrent usage
1604  * in normal, irq, and nmi context.
1605  */
1606 struct bpf_raw_tp_regs {
1607 	struct pt_regs regs[3];
1608 };
1609 static DEFINE_PER_CPU(struct bpf_raw_tp_regs, bpf_raw_tp_regs);
1610 static DEFINE_PER_CPU(int, bpf_raw_tp_nest_level);
1611 static struct pt_regs *get_bpf_raw_tp_regs(void)
1612 {
1613 	struct bpf_raw_tp_regs *tp_regs = this_cpu_ptr(&bpf_raw_tp_regs);
1614 	int nest_level = this_cpu_inc_return(bpf_raw_tp_nest_level);
1615 
1616 	if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(tp_regs->regs))) {
1617 		this_cpu_dec(bpf_raw_tp_nest_level);
1618 		return ERR_PTR(-EBUSY);
1619 	}
1620 
1621 	return &tp_regs->regs[nest_level - 1];
1622 }
1623 
1624 static void put_bpf_raw_tp_regs(void)
1625 {
1626 	this_cpu_dec(bpf_raw_tp_nest_level);
1627 }
1628 
1629 BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args,
1630 	   struct bpf_map *, map, u64, flags, void *, data, u64, size)
1631 {
1632 	struct pt_regs *regs = get_bpf_raw_tp_regs();
1633 	int ret;
1634 
1635 	if (IS_ERR(regs))
1636 		return PTR_ERR(regs);
1637 
1638 	perf_fetch_caller_regs(regs);
1639 	ret = ____bpf_perf_event_output(regs, map, flags, data, size);
1640 
1641 	put_bpf_raw_tp_regs();
1642 	return ret;
1643 }
1644 
1645 static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = {
1646 	.func		= bpf_perf_event_output_raw_tp,
1647 	.gpl_only	= true,
1648 	.ret_type	= RET_INTEGER,
1649 	.arg1_type	= ARG_PTR_TO_CTX,
1650 	.arg2_type	= ARG_CONST_MAP_PTR,
1651 	.arg3_type	= ARG_ANYTHING,
1652 	.arg4_type	= ARG_PTR_TO_MEM,
1653 	.arg5_type	= ARG_CONST_SIZE_OR_ZERO,
1654 };
1655 
1656 extern const struct bpf_func_proto bpf_skb_output_proto;
1657 extern const struct bpf_func_proto bpf_xdp_output_proto;
1658 
1659 BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args,
1660 	   struct bpf_map *, map, u64, flags)
1661 {
1662 	struct pt_regs *regs = get_bpf_raw_tp_regs();
1663 	int ret;
1664 
1665 	if (IS_ERR(regs))
1666 		return PTR_ERR(regs);
1667 
1668 	perf_fetch_caller_regs(regs);
1669 	/* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */
1670 	ret = bpf_get_stackid((unsigned long) regs, (unsigned long) map,
1671 			      flags, 0, 0);
1672 	put_bpf_raw_tp_regs();
1673 	return ret;
1674 }
1675 
1676 static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = {
1677 	.func		= bpf_get_stackid_raw_tp,
1678 	.gpl_only	= true,
1679 	.ret_type	= RET_INTEGER,
1680 	.arg1_type	= ARG_PTR_TO_CTX,
1681 	.arg2_type	= ARG_CONST_MAP_PTR,
1682 	.arg3_type	= ARG_ANYTHING,
1683 };
1684 
1685 BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args,
1686 	   void *, buf, u32, size, u64, flags)
1687 {
1688 	struct pt_regs *regs = get_bpf_raw_tp_regs();
1689 	int ret;
1690 
1691 	if (IS_ERR(regs))
1692 		return PTR_ERR(regs);
1693 
1694 	perf_fetch_caller_regs(regs);
1695 	ret = bpf_get_stack((unsigned long) regs, (unsigned long) buf,
1696 			    (unsigned long) size, flags, 0);
1697 	put_bpf_raw_tp_regs();
1698 	return ret;
1699 }
1700 
1701 static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = {
1702 	.func		= bpf_get_stack_raw_tp,
1703 	.gpl_only	= true,
1704 	.ret_type	= RET_INTEGER,
1705 	.arg1_type	= ARG_PTR_TO_CTX,
1706 	.arg2_type	= ARG_PTR_TO_MEM,
1707 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
1708 	.arg4_type	= ARG_ANYTHING,
1709 };
1710 
1711 static const struct bpf_func_proto *
1712 raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1713 {
1714 	switch (func_id) {
1715 	case BPF_FUNC_perf_event_output:
1716 		return &bpf_perf_event_output_proto_raw_tp;
1717 	case BPF_FUNC_get_stackid:
1718 		return &bpf_get_stackid_proto_raw_tp;
1719 	case BPF_FUNC_get_stack:
1720 		return &bpf_get_stack_proto_raw_tp;
1721 	default:
1722 		return bpf_tracing_func_proto(func_id, prog);
1723 	}
1724 }
1725 
1726 const struct bpf_func_proto *
1727 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1728 {
1729 	switch (func_id) {
1730 #ifdef CONFIG_NET
1731 	case BPF_FUNC_skb_output:
1732 		return &bpf_skb_output_proto;
1733 	case BPF_FUNC_xdp_output:
1734 		return &bpf_xdp_output_proto;
1735 	case BPF_FUNC_skc_to_tcp6_sock:
1736 		return &bpf_skc_to_tcp6_sock_proto;
1737 	case BPF_FUNC_skc_to_tcp_sock:
1738 		return &bpf_skc_to_tcp_sock_proto;
1739 	case BPF_FUNC_skc_to_tcp_timewait_sock:
1740 		return &bpf_skc_to_tcp_timewait_sock_proto;
1741 	case BPF_FUNC_skc_to_tcp_request_sock:
1742 		return &bpf_skc_to_tcp_request_sock_proto;
1743 	case BPF_FUNC_skc_to_udp6_sock:
1744 		return &bpf_skc_to_udp6_sock_proto;
1745 	case BPF_FUNC_sk_storage_get:
1746 		return &bpf_sk_storage_get_tracing_proto;
1747 	case BPF_FUNC_sk_storage_delete:
1748 		return &bpf_sk_storage_delete_tracing_proto;
1749 #endif
1750 	case BPF_FUNC_seq_printf:
1751 		return prog->expected_attach_type == BPF_TRACE_ITER ?
1752 		       &bpf_seq_printf_proto :
1753 		       NULL;
1754 	case BPF_FUNC_seq_write:
1755 		return prog->expected_attach_type == BPF_TRACE_ITER ?
1756 		       &bpf_seq_write_proto :
1757 		       NULL;
1758 	case BPF_FUNC_seq_printf_btf:
1759 		return prog->expected_attach_type == BPF_TRACE_ITER ?
1760 		       &bpf_seq_printf_btf_proto :
1761 		       NULL;
1762 	case BPF_FUNC_d_path:
1763 		return &bpf_d_path_proto;
1764 	default:
1765 		return raw_tp_prog_func_proto(func_id, prog);
1766 	}
1767 }
1768 
1769 static bool raw_tp_prog_is_valid_access(int off, int size,
1770 					enum bpf_access_type type,
1771 					const struct bpf_prog *prog,
1772 					struct bpf_insn_access_aux *info)
1773 {
1774 	if (off < 0 || off >= sizeof(__u64) * MAX_BPF_FUNC_ARGS)
1775 		return false;
1776 	if (type != BPF_READ)
1777 		return false;
1778 	if (off % size != 0)
1779 		return false;
1780 	return true;
1781 }
1782 
1783 static bool tracing_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 btf_ctx_access(off, size, type, prog, info);
1795 }
1796 
1797 int __weak bpf_prog_test_run_tracing(struct bpf_prog *prog,
1798 				     const union bpf_attr *kattr,
1799 				     union bpf_attr __user *uattr)
1800 {
1801 	return -ENOTSUPP;
1802 }
1803 
1804 const struct bpf_verifier_ops raw_tracepoint_verifier_ops = {
1805 	.get_func_proto  = raw_tp_prog_func_proto,
1806 	.is_valid_access = raw_tp_prog_is_valid_access,
1807 };
1808 
1809 const struct bpf_prog_ops raw_tracepoint_prog_ops = {
1810 #ifdef CONFIG_NET
1811 	.test_run = bpf_prog_test_run_raw_tp,
1812 #endif
1813 };
1814 
1815 const struct bpf_verifier_ops tracing_verifier_ops = {
1816 	.get_func_proto  = tracing_prog_func_proto,
1817 	.is_valid_access = tracing_prog_is_valid_access,
1818 };
1819 
1820 const struct bpf_prog_ops tracing_prog_ops = {
1821 	.test_run = bpf_prog_test_run_tracing,
1822 };
1823 
1824 static bool raw_tp_writable_prog_is_valid_access(int off, int size,
1825 						 enum bpf_access_type type,
1826 						 const struct bpf_prog *prog,
1827 						 struct bpf_insn_access_aux *info)
1828 {
1829 	if (off == 0) {
1830 		if (size != sizeof(u64) || type != BPF_READ)
1831 			return false;
1832 		info->reg_type = PTR_TO_TP_BUFFER;
1833 	}
1834 	return raw_tp_prog_is_valid_access(off, size, type, prog, info);
1835 }
1836 
1837 const struct bpf_verifier_ops raw_tracepoint_writable_verifier_ops = {
1838 	.get_func_proto  = raw_tp_prog_func_proto,
1839 	.is_valid_access = raw_tp_writable_prog_is_valid_access,
1840 };
1841 
1842 const struct bpf_prog_ops raw_tracepoint_writable_prog_ops = {
1843 };
1844 
1845 static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
1846 				    const struct bpf_prog *prog,
1847 				    struct bpf_insn_access_aux *info)
1848 {
1849 	const int size_u64 = sizeof(u64);
1850 
1851 	if (off < 0 || off >= sizeof(struct bpf_perf_event_data))
1852 		return false;
1853 	if (type != BPF_READ)
1854 		return false;
1855 	if (off % size != 0) {
1856 		if (sizeof(unsigned long) != 4)
1857 			return false;
1858 		if (size != 8)
1859 			return false;
1860 		if (off % size != 4)
1861 			return false;
1862 	}
1863 
1864 	switch (off) {
1865 	case bpf_ctx_range(struct bpf_perf_event_data, sample_period):
1866 		bpf_ctx_record_field_size(info, size_u64);
1867 		if (!bpf_ctx_narrow_access_ok(off, size, size_u64))
1868 			return false;
1869 		break;
1870 	case bpf_ctx_range(struct bpf_perf_event_data, addr):
1871 		bpf_ctx_record_field_size(info, size_u64);
1872 		if (!bpf_ctx_narrow_access_ok(off, size, size_u64))
1873 			return false;
1874 		break;
1875 	default:
1876 		if (size != sizeof(long))
1877 			return false;
1878 	}
1879 
1880 	return true;
1881 }
1882 
1883 static u32 pe_prog_convert_ctx_access(enum bpf_access_type type,
1884 				      const struct bpf_insn *si,
1885 				      struct bpf_insn *insn_buf,
1886 				      struct bpf_prog *prog, u32 *target_size)
1887 {
1888 	struct bpf_insn *insn = insn_buf;
1889 
1890 	switch (si->off) {
1891 	case offsetof(struct bpf_perf_event_data, sample_period):
1892 		*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
1893 						       data), si->dst_reg, si->src_reg,
1894 				      offsetof(struct bpf_perf_event_data_kern, data));
1895 		*insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg,
1896 				      bpf_target_off(struct perf_sample_data, period, 8,
1897 						     target_size));
1898 		break;
1899 	case offsetof(struct bpf_perf_event_data, addr):
1900 		*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
1901 						       data), si->dst_reg, si->src_reg,
1902 				      offsetof(struct bpf_perf_event_data_kern, data));
1903 		*insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg,
1904 				      bpf_target_off(struct perf_sample_data, addr, 8,
1905 						     target_size));
1906 		break;
1907 	default:
1908 		*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
1909 						       regs), si->dst_reg, si->src_reg,
1910 				      offsetof(struct bpf_perf_event_data_kern, regs));
1911 		*insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg,
1912 				      si->off);
1913 		break;
1914 	}
1915 
1916 	return insn - insn_buf;
1917 }
1918 
1919 const struct bpf_verifier_ops perf_event_verifier_ops = {
1920 	.get_func_proto		= pe_prog_func_proto,
1921 	.is_valid_access	= pe_prog_is_valid_access,
1922 	.convert_ctx_access	= pe_prog_convert_ctx_access,
1923 };
1924 
1925 const struct bpf_prog_ops perf_event_prog_ops = {
1926 };
1927 
1928 static DEFINE_MUTEX(bpf_event_mutex);
1929 
1930 #define BPF_TRACE_MAX_PROGS 64
1931 
1932 int perf_event_attach_bpf_prog(struct perf_event *event,
1933 			       struct bpf_prog *prog)
1934 {
1935 	struct bpf_prog_array *old_array;
1936 	struct bpf_prog_array *new_array;
1937 	int ret = -EEXIST;
1938 
1939 	/*
1940 	 * Kprobe override only works if they are on the function entry,
1941 	 * and only if they are on the opt-in list.
1942 	 */
1943 	if (prog->kprobe_override &&
1944 	    (!trace_kprobe_on_func_entry(event->tp_event) ||
1945 	     !trace_kprobe_error_injectable(event->tp_event)))
1946 		return -EINVAL;
1947 
1948 	mutex_lock(&bpf_event_mutex);
1949 
1950 	if (event->prog)
1951 		goto unlock;
1952 
1953 	old_array = bpf_event_rcu_dereference(event->tp_event->prog_array);
1954 	if (old_array &&
1955 	    bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) {
1956 		ret = -E2BIG;
1957 		goto unlock;
1958 	}
1959 
1960 	ret = bpf_prog_array_copy(old_array, NULL, prog, &new_array);
1961 	if (ret < 0)
1962 		goto unlock;
1963 
1964 	/* set the new array to event->tp_event and set event->prog */
1965 	event->prog = prog;
1966 	rcu_assign_pointer(event->tp_event->prog_array, new_array);
1967 	bpf_prog_array_free(old_array);
1968 
1969 unlock:
1970 	mutex_unlock(&bpf_event_mutex);
1971 	return ret;
1972 }
1973 
1974 void perf_event_detach_bpf_prog(struct perf_event *event)
1975 {
1976 	struct bpf_prog_array *old_array;
1977 	struct bpf_prog_array *new_array;
1978 	int ret;
1979 
1980 	mutex_lock(&bpf_event_mutex);
1981 
1982 	if (!event->prog)
1983 		goto unlock;
1984 
1985 	old_array = bpf_event_rcu_dereference(event->tp_event->prog_array);
1986 	ret = bpf_prog_array_copy(old_array, event->prog, NULL, &new_array);
1987 	if (ret == -ENOENT)
1988 		goto unlock;
1989 	if (ret < 0) {
1990 		bpf_prog_array_delete_safe(old_array, event->prog);
1991 	} else {
1992 		rcu_assign_pointer(event->tp_event->prog_array, new_array);
1993 		bpf_prog_array_free(old_array);
1994 	}
1995 
1996 	bpf_prog_put(event->prog);
1997 	event->prog = NULL;
1998 
1999 unlock:
2000 	mutex_unlock(&bpf_event_mutex);
2001 }
2002 
2003 int perf_event_query_prog_array(struct perf_event *event, void __user *info)
2004 {
2005 	struct perf_event_query_bpf __user *uquery = info;
2006 	struct perf_event_query_bpf query = {};
2007 	struct bpf_prog_array *progs;
2008 	u32 *ids, prog_cnt, ids_len;
2009 	int ret;
2010 
2011 	if (!perfmon_capable())
2012 		return -EPERM;
2013 	if (event->attr.type != PERF_TYPE_TRACEPOINT)
2014 		return -EINVAL;
2015 	if (copy_from_user(&query, uquery, sizeof(query)))
2016 		return -EFAULT;
2017 
2018 	ids_len = query.ids_len;
2019 	if (ids_len > BPF_TRACE_MAX_PROGS)
2020 		return -E2BIG;
2021 	ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN);
2022 	if (!ids)
2023 		return -ENOMEM;
2024 	/*
2025 	 * The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which
2026 	 * is required when user only wants to check for uquery->prog_cnt.
2027 	 * There is no need to check for it since the case is handled
2028 	 * gracefully in bpf_prog_array_copy_info.
2029 	 */
2030 
2031 	mutex_lock(&bpf_event_mutex);
2032 	progs = bpf_event_rcu_dereference(event->tp_event->prog_array);
2033 	ret = bpf_prog_array_copy_info(progs, ids, ids_len, &prog_cnt);
2034 	mutex_unlock(&bpf_event_mutex);
2035 
2036 	if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) ||
2037 	    copy_to_user(uquery->ids, ids, ids_len * sizeof(u32)))
2038 		ret = -EFAULT;
2039 
2040 	kfree(ids);
2041 	return ret;
2042 }
2043 
2044 extern struct bpf_raw_event_map __start__bpf_raw_tp[];
2045 extern struct bpf_raw_event_map __stop__bpf_raw_tp[];
2046 
2047 struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name)
2048 {
2049 	struct bpf_raw_event_map *btp = __start__bpf_raw_tp;
2050 
2051 	for (; btp < __stop__bpf_raw_tp; btp++) {
2052 		if (!strcmp(btp->tp->name, name))
2053 			return btp;
2054 	}
2055 
2056 	return bpf_get_raw_tracepoint_module(name);
2057 }
2058 
2059 void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp)
2060 {
2061 	struct module *mod = __module_address((unsigned long)btp);
2062 
2063 	if (mod)
2064 		module_put(mod);
2065 }
2066 
2067 static __always_inline
2068 void __bpf_trace_run(struct bpf_prog *prog, u64 *args)
2069 {
2070 	cant_sleep();
2071 	rcu_read_lock();
2072 	(void) BPF_PROG_RUN(prog, args);
2073 	rcu_read_unlock();
2074 }
2075 
2076 #define UNPACK(...)			__VA_ARGS__
2077 #define REPEAT_1(FN, DL, X, ...)	FN(X)
2078 #define REPEAT_2(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__)
2079 #define REPEAT_3(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_2(FN, DL, __VA_ARGS__)
2080 #define REPEAT_4(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_3(FN, DL, __VA_ARGS__)
2081 #define REPEAT_5(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_4(FN, DL, __VA_ARGS__)
2082 #define REPEAT_6(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_5(FN, DL, __VA_ARGS__)
2083 #define REPEAT_7(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_6(FN, DL, __VA_ARGS__)
2084 #define REPEAT_8(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_7(FN, DL, __VA_ARGS__)
2085 #define REPEAT_9(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_8(FN, DL, __VA_ARGS__)
2086 #define REPEAT_10(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_9(FN, DL, __VA_ARGS__)
2087 #define REPEAT_11(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_10(FN, DL, __VA_ARGS__)
2088 #define REPEAT_12(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_11(FN, DL, __VA_ARGS__)
2089 #define REPEAT(X, FN, DL, ...)		REPEAT_##X(FN, DL, __VA_ARGS__)
2090 
2091 #define SARG(X)		u64 arg##X
2092 #define COPY(X)		args[X] = arg##X
2093 
2094 #define __DL_COM	(,)
2095 #define __DL_SEM	(;)
2096 
2097 #define __SEQ_0_11	0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11
2098 
2099 #define BPF_TRACE_DEFN_x(x)						\
2100 	void bpf_trace_run##x(struct bpf_prog *prog,			\
2101 			      REPEAT(x, SARG, __DL_COM, __SEQ_0_11))	\
2102 	{								\
2103 		u64 args[x];						\
2104 		REPEAT(x, COPY, __DL_SEM, __SEQ_0_11);			\
2105 		__bpf_trace_run(prog, args);				\
2106 	}								\
2107 	EXPORT_SYMBOL_GPL(bpf_trace_run##x)
2108 BPF_TRACE_DEFN_x(1);
2109 BPF_TRACE_DEFN_x(2);
2110 BPF_TRACE_DEFN_x(3);
2111 BPF_TRACE_DEFN_x(4);
2112 BPF_TRACE_DEFN_x(5);
2113 BPF_TRACE_DEFN_x(6);
2114 BPF_TRACE_DEFN_x(7);
2115 BPF_TRACE_DEFN_x(8);
2116 BPF_TRACE_DEFN_x(9);
2117 BPF_TRACE_DEFN_x(10);
2118 BPF_TRACE_DEFN_x(11);
2119 BPF_TRACE_DEFN_x(12);
2120 
2121 static int __bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog)
2122 {
2123 	struct tracepoint *tp = btp->tp;
2124 
2125 	/*
2126 	 * check that program doesn't access arguments beyond what's
2127 	 * available in this tracepoint
2128 	 */
2129 	if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64))
2130 		return -EINVAL;
2131 
2132 	if (prog->aux->max_tp_access > btp->writable_size)
2133 		return -EINVAL;
2134 
2135 	return tracepoint_probe_register(tp, (void *)btp->bpf_func, prog);
2136 }
2137 
2138 int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog)
2139 {
2140 	return __bpf_probe_register(btp, prog);
2141 }
2142 
2143 int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_prog *prog)
2144 {
2145 	return tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, prog);
2146 }
2147 
2148 int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id,
2149 			    u32 *fd_type, const char **buf,
2150 			    u64 *probe_offset, u64 *probe_addr)
2151 {
2152 	bool is_tracepoint, is_syscall_tp;
2153 	struct bpf_prog *prog;
2154 	int flags, err = 0;
2155 
2156 	prog = event->prog;
2157 	if (!prog)
2158 		return -ENOENT;
2159 
2160 	/* not supporting BPF_PROG_TYPE_PERF_EVENT yet */
2161 	if (prog->type == BPF_PROG_TYPE_PERF_EVENT)
2162 		return -EOPNOTSUPP;
2163 
2164 	*prog_id = prog->aux->id;
2165 	flags = event->tp_event->flags;
2166 	is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT;
2167 	is_syscall_tp = is_syscall_trace_event(event->tp_event);
2168 
2169 	if (is_tracepoint || is_syscall_tp) {
2170 		*buf = is_tracepoint ? event->tp_event->tp->name
2171 				     : event->tp_event->name;
2172 		*fd_type = BPF_FD_TYPE_TRACEPOINT;
2173 		*probe_offset = 0x0;
2174 		*probe_addr = 0x0;
2175 	} else {
2176 		/* kprobe/uprobe */
2177 		err = -EOPNOTSUPP;
2178 #ifdef CONFIG_KPROBE_EVENTS
2179 		if (flags & TRACE_EVENT_FL_KPROBE)
2180 			err = bpf_get_kprobe_info(event, fd_type, buf,
2181 						  probe_offset, probe_addr,
2182 						  event->attr.type == PERF_TYPE_TRACEPOINT);
2183 #endif
2184 #ifdef CONFIG_UPROBE_EVENTS
2185 		if (flags & TRACE_EVENT_FL_UPROBE)
2186 			err = bpf_get_uprobe_info(event, fd_type, buf,
2187 						  probe_offset,
2188 						  event->attr.type == PERF_TYPE_TRACEPOINT);
2189 #endif
2190 	}
2191 
2192 	return err;
2193 }
2194 
2195 static int __init send_signal_irq_work_init(void)
2196 {
2197 	int cpu;
2198 	struct send_signal_irq_work *work;
2199 
2200 	for_each_possible_cpu(cpu) {
2201 		work = per_cpu_ptr(&send_signal_work, cpu);
2202 		init_irq_work(&work->irq_work, do_bpf_send_signal);
2203 	}
2204 	return 0;
2205 }
2206 
2207 subsys_initcall(send_signal_irq_work_init);
2208 
2209 #ifdef CONFIG_MODULES
2210 static int bpf_event_notify(struct notifier_block *nb, unsigned long op,
2211 			    void *module)
2212 {
2213 	struct bpf_trace_module *btm, *tmp;
2214 	struct module *mod = module;
2215 	int ret = 0;
2216 
2217 	if (mod->num_bpf_raw_events == 0 ||
2218 	    (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING))
2219 		goto out;
2220 
2221 	mutex_lock(&bpf_module_mutex);
2222 
2223 	switch (op) {
2224 	case MODULE_STATE_COMING:
2225 		btm = kzalloc(sizeof(*btm), GFP_KERNEL);
2226 		if (btm) {
2227 			btm->module = module;
2228 			list_add(&btm->list, &bpf_trace_modules);
2229 		} else {
2230 			ret = -ENOMEM;
2231 		}
2232 		break;
2233 	case MODULE_STATE_GOING:
2234 		list_for_each_entry_safe(btm, tmp, &bpf_trace_modules, list) {
2235 			if (btm->module == module) {
2236 				list_del(&btm->list);
2237 				kfree(btm);
2238 				break;
2239 			}
2240 		}
2241 		break;
2242 	}
2243 
2244 	mutex_unlock(&bpf_module_mutex);
2245 
2246 out:
2247 	return notifier_from_errno(ret);
2248 }
2249 
2250 static struct notifier_block bpf_module_nb = {
2251 	.notifier_call = bpf_event_notify,
2252 };
2253 
2254 static int __init bpf_event_init(void)
2255 {
2256 	register_module_notifier(&bpf_module_nb);
2257 	return 0;
2258 }
2259 
2260 fs_initcall(bpf_event_init);
2261 #endif /* CONFIG_MODULES */
2262