xref: /openbmc/linux/kernel/trace/bpf_trace.c (revision abcda807)
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 
20 #include <uapi/linux/bpf.h>
21 #include <uapi/linux/btf.h>
22 
23 #include <asm/tlb.h>
24 
25 #include "trace_probe.h"
26 #include "trace.h"
27 
28 #define CREATE_TRACE_POINTS
29 #include "bpf_trace.h"
30 
31 #define bpf_event_rcu_dereference(p)					\
32 	rcu_dereference_protected(p, lockdep_is_held(&bpf_event_mutex))
33 
34 #ifdef CONFIG_MODULES
35 struct bpf_trace_module {
36 	struct module *module;
37 	struct list_head list;
38 };
39 
40 static LIST_HEAD(bpf_trace_modules);
41 static DEFINE_MUTEX(bpf_module_mutex);
42 
43 static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name)
44 {
45 	struct bpf_raw_event_map *btp, *ret = NULL;
46 	struct bpf_trace_module *btm;
47 	unsigned int i;
48 
49 	mutex_lock(&bpf_module_mutex);
50 	list_for_each_entry(btm, &bpf_trace_modules, list) {
51 		for (i = 0; i < btm->module->num_bpf_raw_events; ++i) {
52 			btp = &btm->module->bpf_raw_events[i];
53 			if (!strcmp(btp->tp->name, name)) {
54 				if (try_module_get(btm->module))
55 					ret = btp;
56 				goto out;
57 			}
58 		}
59 	}
60 out:
61 	mutex_unlock(&bpf_module_mutex);
62 	return ret;
63 }
64 #else
65 static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name)
66 {
67 	return NULL;
68 }
69 #endif /* CONFIG_MODULES */
70 
71 u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
72 u64 bpf_get_stack(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
73 
74 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size,
75 				  u64 flags, const struct btf **btf,
76 				  s32 *btf_id);
77 
78 /**
79  * trace_call_bpf - invoke BPF program
80  * @call: tracepoint event
81  * @ctx: opaque context pointer
82  *
83  * kprobe handlers execute BPF programs via this helper.
84  * Can be used from static tracepoints in the future.
85  *
86  * Return: BPF programs always return an integer which is interpreted by
87  * kprobe handler as:
88  * 0 - return from kprobe (event is filtered out)
89  * 1 - store kprobe event into ring buffer
90  * Other values are reserved and currently alias to 1
91  */
92 unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx)
93 {
94 	unsigned int ret;
95 
96 	if (in_nmi()) /* not supported yet */
97 		return 1;
98 
99 	cant_sleep();
100 
101 	if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) {
102 		/*
103 		 * since some bpf program is already running on this cpu,
104 		 * don't call into another bpf program (same or different)
105 		 * and don't send kprobe event into ring-buffer,
106 		 * so return zero here
107 		 */
108 		ret = 0;
109 		goto out;
110 	}
111 
112 	/*
113 	 * Instead of moving rcu_read_lock/rcu_dereference/rcu_read_unlock
114 	 * to all call sites, we did a bpf_prog_array_valid() there to check
115 	 * whether call->prog_array is empty or not, which is
116 	 * a heurisitc to speed up execution.
117 	 *
118 	 * If bpf_prog_array_valid() fetched prog_array was
119 	 * non-NULL, we go into trace_call_bpf() and do the actual
120 	 * proper rcu_dereference() under RCU lock.
121 	 * If it turns out that prog_array is NULL then, we bail out.
122 	 * For the opposite, if the bpf_prog_array_valid() fetched pointer
123 	 * was NULL, you'll skip the prog_array with the risk of missing
124 	 * out of events when it was updated in between this and the
125 	 * rcu_dereference() which is accepted risk.
126 	 */
127 	ret = BPF_PROG_RUN_ARRAY_CHECK(call->prog_array, ctx, BPF_PROG_RUN);
128 
129  out:
130 	__this_cpu_dec(bpf_prog_active);
131 
132 	return ret;
133 }
134 
135 #ifdef CONFIG_BPF_KPROBE_OVERRIDE
136 BPF_CALL_2(bpf_override_return, struct pt_regs *, regs, unsigned long, rc)
137 {
138 	regs_set_return_value(regs, rc);
139 	override_function_with_return(regs);
140 	return 0;
141 }
142 
143 static const struct bpf_func_proto bpf_override_return_proto = {
144 	.func		= bpf_override_return,
145 	.gpl_only	= true,
146 	.ret_type	= RET_INTEGER,
147 	.arg1_type	= ARG_PTR_TO_CTX,
148 	.arg2_type	= ARG_ANYTHING,
149 };
150 #endif
151 
152 static __always_inline int
153 bpf_probe_read_user_common(void *dst, u32 size, const void __user *unsafe_ptr)
154 {
155 	int ret;
156 
157 	ret = copy_from_user_nofault(dst, unsafe_ptr, size);
158 	if (unlikely(ret < 0))
159 		memset(dst, 0, size);
160 	return ret;
161 }
162 
163 BPF_CALL_3(bpf_probe_read_user, void *, dst, u32, size,
164 	   const void __user *, unsafe_ptr)
165 {
166 	return bpf_probe_read_user_common(dst, size, unsafe_ptr);
167 }
168 
169 const struct bpf_func_proto bpf_probe_read_user_proto = {
170 	.func		= bpf_probe_read_user,
171 	.gpl_only	= true,
172 	.ret_type	= RET_INTEGER,
173 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
174 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
175 	.arg3_type	= ARG_ANYTHING,
176 };
177 
178 static __always_inline int
179 bpf_probe_read_user_str_common(void *dst, u32 size,
180 			       const void __user *unsafe_ptr)
181 {
182 	int ret;
183 
184 	ret = strncpy_from_user_nofault(dst, unsafe_ptr, size);
185 	if (unlikely(ret < 0))
186 		memset(dst, 0, size);
187 	return ret;
188 }
189 
190 BPF_CALL_3(bpf_probe_read_user_str, void *, dst, u32, size,
191 	   const void __user *, unsafe_ptr)
192 {
193 	return bpf_probe_read_user_str_common(dst, size, unsafe_ptr);
194 }
195 
196 const struct bpf_func_proto bpf_probe_read_user_str_proto = {
197 	.func		= bpf_probe_read_user_str,
198 	.gpl_only	= true,
199 	.ret_type	= RET_INTEGER,
200 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
201 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
202 	.arg3_type	= ARG_ANYTHING,
203 };
204 
205 static __always_inline int
206 bpf_probe_read_kernel_common(void *dst, u32 size, const void *unsafe_ptr)
207 {
208 	int ret = security_locked_down(LOCKDOWN_BPF_READ);
209 
210 	if (unlikely(ret < 0))
211 		goto fail;
212 	ret = copy_from_kernel_nofault(dst, unsafe_ptr, size);
213 	if (unlikely(ret < 0))
214 		goto fail;
215 	return ret;
216 fail:
217 	memset(dst, 0, size);
218 	return ret;
219 }
220 
221 BPF_CALL_3(bpf_probe_read_kernel, void *, dst, u32, size,
222 	   const void *, unsafe_ptr)
223 {
224 	return bpf_probe_read_kernel_common(dst, size, unsafe_ptr);
225 }
226 
227 const struct bpf_func_proto bpf_probe_read_kernel_proto = {
228 	.func		= bpf_probe_read_kernel,
229 	.gpl_only	= true,
230 	.ret_type	= RET_INTEGER,
231 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
232 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
233 	.arg3_type	= ARG_ANYTHING,
234 };
235 
236 static __always_inline int
237 bpf_probe_read_kernel_str_common(void *dst, u32 size, const void *unsafe_ptr)
238 {
239 	int ret = security_locked_down(LOCKDOWN_BPF_READ);
240 
241 	if (unlikely(ret < 0))
242 		goto fail;
243 
244 	/*
245 	 * The strncpy_from_kernel_nofault() call will likely not fill the
246 	 * entire buffer, but that's okay in this circumstance as we're probing
247 	 * arbitrary memory anyway similar to bpf_probe_read_*() and might
248 	 * as well probe the stack. Thus, memory is explicitly cleared
249 	 * only in error case, so that improper users ignoring return
250 	 * code altogether don't copy garbage; otherwise length of string
251 	 * is returned that can be used for bpf_perf_event_output() et al.
252 	 */
253 	ret = strncpy_from_kernel_nofault(dst, unsafe_ptr, size);
254 	if (unlikely(ret < 0))
255 		goto fail;
256 
257 	return ret;
258 fail:
259 	memset(dst, 0, size);
260 	return ret;
261 }
262 
263 BPF_CALL_3(bpf_probe_read_kernel_str, void *, dst, u32, size,
264 	   const void *, unsafe_ptr)
265 {
266 	return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr);
267 }
268 
269 const struct bpf_func_proto bpf_probe_read_kernel_str_proto = {
270 	.func		= bpf_probe_read_kernel_str,
271 	.gpl_only	= true,
272 	.ret_type	= RET_INTEGER,
273 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
274 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
275 	.arg3_type	= ARG_ANYTHING,
276 };
277 
278 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
279 BPF_CALL_3(bpf_probe_read_compat, void *, dst, u32, size,
280 	   const void *, unsafe_ptr)
281 {
282 	if ((unsigned long)unsafe_ptr < TASK_SIZE) {
283 		return bpf_probe_read_user_common(dst, size,
284 				(__force void __user *)unsafe_ptr);
285 	}
286 	return bpf_probe_read_kernel_common(dst, size, unsafe_ptr);
287 }
288 
289 static const struct bpf_func_proto bpf_probe_read_compat_proto = {
290 	.func		= bpf_probe_read_compat,
291 	.gpl_only	= true,
292 	.ret_type	= RET_INTEGER,
293 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
294 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
295 	.arg3_type	= ARG_ANYTHING,
296 };
297 
298 BPF_CALL_3(bpf_probe_read_compat_str, void *, dst, u32, size,
299 	   const void *, unsafe_ptr)
300 {
301 	if ((unsigned long)unsafe_ptr < TASK_SIZE) {
302 		return bpf_probe_read_user_str_common(dst, size,
303 				(__force void __user *)unsafe_ptr);
304 	}
305 	return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr);
306 }
307 
308 static const struct bpf_func_proto bpf_probe_read_compat_str_proto = {
309 	.func		= bpf_probe_read_compat_str,
310 	.gpl_only	= true,
311 	.ret_type	= RET_INTEGER,
312 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
313 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
314 	.arg3_type	= ARG_ANYTHING,
315 };
316 #endif /* CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE */
317 
318 BPF_CALL_3(bpf_probe_write_user, void __user *, unsafe_ptr, const void *, src,
319 	   u32, size)
320 {
321 	/*
322 	 * Ensure we're in user context which is safe for the helper to
323 	 * run. This helper has no business in a kthread.
324 	 *
325 	 * access_ok() should prevent writing to non-user memory, but in
326 	 * some situations (nommu, temporary switch, etc) access_ok() does
327 	 * not provide enough validation, hence the check on KERNEL_DS.
328 	 *
329 	 * nmi_uaccess_okay() ensures the probe is not run in an interim
330 	 * state, when the task or mm are switched. This is specifically
331 	 * required to prevent the use of temporary mm.
332 	 */
333 
334 	if (unlikely(in_interrupt() ||
335 		     current->flags & (PF_KTHREAD | PF_EXITING)))
336 		return -EPERM;
337 	if (unlikely(uaccess_kernel()))
338 		return -EPERM;
339 	if (unlikely(!nmi_uaccess_okay()))
340 		return -EPERM;
341 
342 	return copy_to_user_nofault(unsafe_ptr, src, size);
343 }
344 
345 static const struct bpf_func_proto bpf_probe_write_user_proto = {
346 	.func		= bpf_probe_write_user,
347 	.gpl_only	= true,
348 	.ret_type	= RET_INTEGER,
349 	.arg1_type	= ARG_ANYTHING,
350 	.arg2_type	= ARG_PTR_TO_MEM,
351 	.arg3_type	= ARG_CONST_SIZE,
352 };
353 
354 static const struct bpf_func_proto *bpf_get_probe_write_proto(void)
355 {
356 	if (!capable(CAP_SYS_ADMIN))
357 		return NULL;
358 
359 	pr_warn_ratelimited("%s[%d] is installing a program with bpf_probe_write_user helper that may corrupt user memory!",
360 			    current->comm, task_pid_nr(current));
361 
362 	return &bpf_probe_write_user_proto;
363 }
364 
365 static void bpf_trace_copy_string(char *buf, void *unsafe_ptr, char fmt_ptype,
366 		size_t bufsz)
367 {
368 	void __user *user_ptr = (__force void __user *)unsafe_ptr;
369 
370 	buf[0] = 0;
371 
372 	switch (fmt_ptype) {
373 	case 's':
374 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
375 		if ((unsigned long)unsafe_ptr < TASK_SIZE) {
376 			strncpy_from_user_nofault(buf, user_ptr, bufsz);
377 			break;
378 		}
379 		fallthrough;
380 #endif
381 	case 'k':
382 		strncpy_from_kernel_nofault(buf, unsafe_ptr, bufsz);
383 		break;
384 	case 'u':
385 		strncpy_from_user_nofault(buf, user_ptr, bufsz);
386 		break;
387 	}
388 }
389 
390 static DEFINE_RAW_SPINLOCK(trace_printk_lock);
391 
392 #define BPF_TRACE_PRINTK_SIZE   1024
393 
394 static __printf(1, 0) int bpf_do_trace_printk(const char *fmt, ...)
395 {
396 	static char buf[BPF_TRACE_PRINTK_SIZE];
397 	unsigned long flags;
398 	va_list ap;
399 	int ret;
400 
401 	raw_spin_lock_irqsave(&trace_printk_lock, flags);
402 	va_start(ap, fmt);
403 	ret = vsnprintf(buf, sizeof(buf), fmt, ap);
404 	va_end(ap);
405 	/* vsnprintf() will not append null for zero-length strings */
406 	if (ret == 0)
407 		buf[0] = '\0';
408 	trace_bpf_trace_printk(buf);
409 	raw_spin_unlock_irqrestore(&trace_printk_lock, flags);
410 
411 	return ret;
412 }
413 
414 /*
415  * Only limited trace_printk() conversion specifiers allowed:
416  * %d %i %u %x %ld %li %lu %lx %lld %lli %llu %llx %p %pB %pks %pus %s
417  */
418 BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1,
419 	   u64, arg2, u64, arg3)
420 {
421 	int i, mod[3] = {}, fmt_cnt = 0;
422 	char buf[64], fmt_ptype;
423 	void *unsafe_ptr = NULL;
424 	bool str_seen = false;
425 
426 	/*
427 	 * bpf_check()->check_func_arg()->check_stack_boundary()
428 	 * guarantees that fmt points to bpf program stack,
429 	 * fmt_size bytes of it were initialized and fmt_size > 0
430 	 */
431 	if (fmt[--fmt_size] != 0)
432 		return -EINVAL;
433 
434 	/* check format string for allowed specifiers */
435 	for (i = 0; i < fmt_size; i++) {
436 		if ((!isprint(fmt[i]) && !isspace(fmt[i])) || !isascii(fmt[i]))
437 			return -EINVAL;
438 
439 		if (fmt[i] != '%')
440 			continue;
441 
442 		if (fmt_cnt >= 3)
443 			return -EINVAL;
444 
445 		/* fmt[i] != 0 && fmt[last] == 0, so we can access fmt[i + 1] */
446 		i++;
447 		if (fmt[i] == 'l') {
448 			mod[fmt_cnt]++;
449 			i++;
450 		} else if (fmt[i] == 'p') {
451 			mod[fmt_cnt]++;
452 			if ((fmt[i + 1] == 'k' ||
453 			     fmt[i + 1] == 'u') &&
454 			    fmt[i + 2] == 's') {
455 				fmt_ptype = fmt[i + 1];
456 				i += 2;
457 				goto fmt_str;
458 			}
459 
460 			if (fmt[i + 1] == 'B') {
461 				i++;
462 				goto fmt_next;
463 			}
464 
465 			/* disallow any further format extensions */
466 			if (fmt[i + 1] != 0 &&
467 			    !isspace(fmt[i + 1]) &&
468 			    !ispunct(fmt[i + 1]))
469 				return -EINVAL;
470 
471 			goto fmt_next;
472 		} else if (fmt[i] == 's') {
473 			mod[fmt_cnt]++;
474 			fmt_ptype = fmt[i];
475 fmt_str:
476 			if (str_seen)
477 				/* allow only one '%s' per fmt string */
478 				return -EINVAL;
479 			str_seen = true;
480 
481 			if (fmt[i + 1] != 0 &&
482 			    !isspace(fmt[i + 1]) &&
483 			    !ispunct(fmt[i + 1]))
484 				return -EINVAL;
485 
486 			switch (fmt_cnt) {
487 			case 0:
488 				unsafe_ptr = (void *)(long)arg1;
489 				arg1 = (long)buf;
490 				break;
491 			case 1:
492 				unsafe_ptr = (void *)(long)arg2;
493 				arg2 = (long)buf;
494 				break;
495 			case 2:
496 				unsafe_ptr = (void *)(long)arg3;
497 				arg3 = (long)buf;
498 				break;
499 			}
500 
501 			bpf_trace_copy_string(buf, unsafe_ptr, fmt_ptype,
502 					sizeof(buf));
503 			goto fmt_next;
504 		}
505 
506 		if (fmt[i] == 'l') {
507 			mod[fmt_cnt]++;
508 			i++;
509 		}
510 
511 		if (fmt[i] != 'i' && fmt[i] != 'd' &&
512 		    fmt[i] != 'u' && fmt[i] != 'x')
513 			return -EINVAL;
514 fmt_next:
515 		fmt_cnt++;
516 	}
517 
518 /* Horrid workaround for getting va_list handling working with different
519  * argument type combinations generically for 32 and 64 bit archs.
520  */
521 #define __BPF_TP_EMIT()	__BPF_ARG3_TP()
522 #define __BPF_TP(...)							\
523 	bpf_do_trace_printk(fmt, ##__VA_ARGS__)
524 
525 #define __BPF_ARG1_TP(...)						\
526 	((mod[0] == 2 || (mod[0] == 1 && __BITS_PER_LONG == 64))	\
527 	  ? __BPF_TP(arg1, ##__VA_ARGS__)				\
528 	  : ((mod[0] == 1 || (mod[0] == 0 && __BITS_PER_LONG == 32))	\
529 	      ? __BPF_TP((long)arg1, ##__VA_ARGS__)			\
530 	      : __BPF_TP((u32)arg1, ##__VA_ARGS__)))
531 
532 #define __BPF_ARG2_TP(...)						\
533 	((mod[1] == 2 || (mod[1] == 1 && __BITS_PER_LONG == 64))	\
534 	  ? __BPF_ARG1_TP(arg2, ##__VA_ARGS__)				\
535 	  : ((mod[1] == 1 || (mod[1] == 0 && __BITS_PER_LONG == 32))	\
536 	      ? __BPF_ARG1_TP((long)arg2, ##__VA_ARGS__)		\
537 	      : __BPF_ARG1_TP((u32)arg2, ##__VA_ARGS__)))
538 
539 #define __BPF_ARG3_TP(...)						\
540 	((mod[2] == 2 || (mod[2] == 1 && __BITS_PER_LONG == 64))	\
541 	  ? __BPF_ARG2_TP(arg3, ##__VA_ARGS__)				\
542 	  : ((mod[2] == 1 || (mod[2] == 0 && __BITS_PER_LONG == 32))	\
543 	      ? __BPF_ARG2_TP((long)arg3, ##__VA_ARGS__)		\
544 	      : __BPF_ARG2_TP((u32)arg3, ##__VA_ARGS__)))
545 
546 	return __BPF_TP_EMIT();
547 }
548 
549 static const struct bpf_func_proto bpf_trace_printk_proto = {
550 	.func		= bpf_trace_printk,
551 	.gpl_only	= true,
552 	.ret_type	= RET_INTEGER,
553 	.arg1_type	= ARG_PTR_TO_MEM,
554 	.arg2_type	= ARG_CONST_SIZE,
555 };
556 
557 const struct bpf_func_proto *bpf_get_trace_printk_proto(void)
558 {
559 	/*
560 	 * This program might be calling bpf_trace_printk,
561 	 * so enable the associated bpf_trace/bpf_trace_printk event.
562 	 * Repeat this each time as it is possible a user has
563 	 * disabled bpf_trace_printk events.  By loading a program
564 	 * calling bpf_trace_printk() however the user has expressed
565 	 * the intent to see such events.
566 	 */
567 	if (trace_set_clr_event("bpf_trace", "bpf_trace_printk", 1))
568 		pr_warn_ratelimited("could not enable bpf_trace_printk events");
569 
570 	return &bpf_trace_printk_proto;
571 }
572 
573 #define MAX_SEQ_PRINTF_VARARGS		12
574 #define MAX_SEQ_PRINTF_MAX_MEMCPY	6
575 #define MAX_SEQ_PRINTF_STR_LEN		128
576 
577 struct bpf_seq_printf_buf {
578 	char buf[MAX_SEQ_PRINTF_MAX_MEMCPY][MAX_SEQ_PRINTF_STR_LEN];
579 };
580 static DEFINE_PER_CPU(struct bpf_seq_printf_buf, bpf_seq_printf_buf);
581 static DEFINE_PER_CPU(int, bpf_seq_printf_buf_used);
582 
583 BPF_CALL_5(bpf_seq_printf, struct seq_file *, m, char *, fmt, u32, fmt_size,
584 	   const void *, data, u32, data_len)
585 {
586 	int err = -EINVAL, fmt_cnt = 0, memcpy_cnt = 0;
587 	int i, buf_used, copy_size, num_args;
588 	u64 params[MAX_SEQ_PRINTF_VARARGS];
589 	struct bpf_seq_printf_buf *bufs;
590 	const u64 *args = data;
591 
592 	buf_used = this_cpu_inc_return(bpf_seq_printf_buf_used);
593 	if (WARN_ON_ONCE(buf_used > 1)) {
594 		err = -EBUSY;
595 		goto out;
596 	}
597 
598 	bufs = this_cpu_ptr(&bpf_seq_printf_buf);
599 
600 	/*
601 	 * bpf_check()->check_func_arg()->check_stack_boundary()
602 	 * guarantees that fmt points to bpf program stack,
603 	 * fmt_size bytes of it were initialized and fmt_size > 0
604 	 */
605 	if (fmt[--fmt_size] != 0)
606 		goto out;
607 
608 	if (data_len & 7)
609 		goto out;
610 
611 	for (i = 0; i < fmt_size; i++) {
612 		if (fmt[i] == '%') {
613 			if (fmt[i + 1] == '%')
614 				i++;
615 			else if (!data || !data_len)
616 				goto out;
617 		}
618 	}
619 
620 	num_args = data_len / 8;
621 
622 	/* check format string for allowed specifiers */
623 	for (i = 0; i < fmt_size; i++) {
624 		/* only printable ascii for now. */
625 		if ((!isprint(fmt[i]) && !isspace(fmt[i])) || !isascii(fmt[i])) {
626 			err = -EINVAL;
627 			goto out;
628 		}
629 
630 		if (fmt[i] != '%')
631 			continue;
632 
633 		if (fmt[i + 1] == '%') {
634 			i++;
635 			continue;
636 		}
637 
638 		if (fmt_cnt >= MAX_SEQ_PRINTF_VARARGS) {
639 			err = -E2BIG;
640 			goto out;
641 		}
642 
643 		if (fmt_cnt >= num_args) {
644 			err = -EINVAL;
645 			goto out;
646 		}
647 
648 		/* fmt[i] != 0 && fmt[last] == 0, so we can access fmt[i + 1] */
649 		i++;
650 
651 		/* skip optional "[0 +-][num]" width formating field */
652 		while (fmt[i] == '0' || fmt[i] == '+'  || fmt[i] == '-' ||
653 		       fmt[i] == ' ')
654 			i++;
655 		if (fmt[i] >= '1' && fmt[i] <= '9') {
656 			i++;
657 			while (fmt[i] >= '0' && fmt[i] <= '9')
658 				i++;
659 		}
660 
661 		if (fmt[i] == 's') {
662 			void *unsafe_ptr;
663 
664 			/* try our best to copy */
665 			if (memcpy_cnt >= MAX_SEQ_PRINTF_MAX_MEMCPY) {
666 				err = -E2BIG;
667 				goto out;
668 			}
669 
670 			unsafe_ptr = (void *)(long)args[fmt_cnt];
671 			err = strncpy_from_kernel_nofault(bufs->buf[memcpy_cnt],
672 					unsafe_ptr, MAX_SEQ_PRINTF_STR_LEN);
673 			if (err < 0)
674 				bufs->buf[memcpy_cnt][0] = '\0';
675 			params[fmt_cnt] = (u64)(long)bufs->buf[memcpy_cnt];
676 
677 			fmt_cnt++;
678 			memcpy_cnt++;
679 			continue;
680 		}
681 
682 		if (fmt[i] == 'p') {
683 			if (fmt[i + 1] == 0 ||
684 			    fmt[i + 1] == 'K' ||
685 			    fmt[i + 1] == 'x' ||
686 			    fmt[i + 1] == 'B') {
687 				/* just kernel pointers */
688 				params[fmt_cnt] = args[fmt_cnt];
689 				fmt_cnt++;
690 				continue;
691 			}
692 
693 			/* only support "%pI4", "%pi4", "%pI6" and "%pi6". */
694 			if (fmt[i + 1] != 'i' && fmt[i + 1] != 'I') {
695 				err = -EINVAL;
696 				goto out;
697 			}
698 			if (fmt[i + 2] != '4' && fmt[i + 2] != '6') {
699 				err = -EINVAL;
700 				goto out;
701 			}
702 
703 			if (memcpy_cnt >= MAX_SEQ_PRINTF_MAX_MEMCPY) {
704 				err = -E2BIG;
705 				goto out;
706 			}
707 
708 
709 			copy_size = (fmt[i + 2] == '4') ? 4 : 16;
710 
711 			err = copy_from_kernel_nofault(bufs->buf[memcpy_cnt],
712 						(void *) (long) args[fmt_cnt],
713 						copy_size);
714 			if (err < 0)
715 				memset(bufs->buf[memcpy_cnt], 0, copy_size);
716 			params[fmt_cnt] = (u64)(long)bufs->buf[memcpy_cnt];
717 
718 			i += 2;
719 			fmt_cnt++;
720 			memcpy_cnt++;
721 			continue;
722 		}
723 
724 		if (fmt[i] == 'l') {
725 			i++;
726 			if (fmt[i] == 'l')
727 				i++;
728 		}
729 
730 		if (fmt[i] != 'i' && fmt[i] != 'd' &&
731 		    fmt[i] != 'u' && fmt[i] != 'x' &&
732 		    fmt[i] != 'X') {
733 			err = -EINVAL;
734 			goto out;
735 		}
736 
737 		params[fmt_cnt] = args[fmt_cnt];
738 		fmt_cnt++;
739 	}
740 
741 	/* Maximumly we can have MAX_SEQ_PRINTF_VARARGS parameter, just give
742 	 * all of them to seq_printf().
743 	 */
744 	seq_printf(m, fmt, params[0], params[1], params[2], params[3],
745 		   params[4], params[5], params[6], params[7], params[8],
746 		   params[9], params[10], params[11]);
747 
748 	err = seq_has_overflowed(m) ? -EOVERFLOW : 0;
749 out:
750 	this_cpu_dec(bpf_seq_printf_buf_used);
751 	return err;
752 }
753 
754 BTF_ID_LIST_SINGLE(btf_seq_file_ids, struct, seq_file)
755 
756 static const struct bpf_func_proto bpf_seq_printf_proto = {
757 	.func		= bpf_seq_printf,
758 	.gpl_only	= true,
759 	.ret_type	= RET_INTEGER,
760 	.arg1_type	= ARG_PTR_TO_BTF_ID,
761 	.arg1_btf_id	= &btf_seq_file_ids[0],
762 	.arg2_type	= ARG_PTR_TO_MEM,
763 	.arg3_type	= ARG_CONST_SIZE,
764 	.arg4_type      = ARG_PTR_TO_MEM_OR_NULL,
765 	.arg5_type      = ARG_CONST_SIZE_OR_ZERO,
766 };
767 
768 BPF_CALL_3(bpf_seq_write, struct seq_file *, m, const void *, data, u32, len)
769 {
770 	return seq_write(m, data, len) ? -EOVERFLOW : 0;
771 }
772 
773 static const struct bpf_func_proto bpf_seq_write_proto = {
774 	.func		= bpf_seq_write,
775 	.gpl_only	= true,
776 	.ret_type	= RET_INTEGER,
777 	.arg1_type	= ARG_PTR_TO_BTF_ID,
778 	.arg1_btf_id	= &btf_seq_file_ids[0],
779 	.arg2_type	= ARG_PTR_TO_MEM,
780 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
781 };
782 
783 BPF_CALL_4(bpf_seq_printf_btf, struct seq_file *, m, struct btf_ptr *, ptr,
784 	   u32, btf_ptr_size, u64, flags)
785 {
786 	const struct btf *btf;
787 	s32 btf_id;
788 	int ret;
789 
790 	ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id);
791 	if (ret)
792 		return ret;
793 
794 	return btf_type_seq_show_flags(btf, btf_id, ptr->ptr, m, flags);
795 }
796 
797 static const struct bpf_func_proto bpf_seq_printf_btf_proto = {
798 	.func		= bpf_seq_printf_btf,
799 	.gpl_only	= true,
800 	.ret_type	= RET_INTEGER,
801 	.arg1_type	= ARG_PTR_TO_BTF_ID,
802 	.arg1_btf_id	= &btf_seq_file_ids[0],
803 	.arg2_type	= ARG_PTR_TO_MEM,
804 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
805 	.arg4_type	= ARG_ANYTHING,
806 };
807 
808 static __always_inline int
809 get_map_perf_counter(struct bpf_map *map, u64 flags,
810 		     u64 *value, u64 *enabled, u64 *running)
811 {
812 	struct bpf_array *array = container_of(map, struct bpf_array, map);
813 	unsigned int cpu = smp_processor_id();
814 	u64 index = flags & BPF_F_INDEX_MASK;
815 	struct bpf_event_entry *ee;
816 
817 	if (unlikely(flags & ~(BPF_F_INDEX_MASK)))
818 		return -EINVAL;
819 	if (index == BPF_F_CURRENT_CPU)
820 		index = cpu;
821 	if (unlikely(index >= array->map.max_entries))
822 		return -E2BIG;
823 
824 	ee = READ_ONCE(array->ptrs[index]);
825 	if (!ee)
826 		return -ENOENT;
827 
828 	return perf_event_read_local(ee->event, value, enabled, running);
829 }
830 
831 BPF_CALL_2(bpf_perf_event_read, struct bpf_map *, map, u64, flags)
832 {
833 	u64 value = 0;
834 	int err;
835 
836 	err = get_map_perf_counter(map, flags, &value, NULL, NULL);
837 	/*
838 	 * this api is ugly since we miss [-22..-2] range of valid
839 	 * counter values, but that's uapi
840 	 */
841 	if (err)
842 		return err;
843 	return value;
844 }
845 
846 static const struct bpf_func_proto bpf_perf_event_read_proto = {
847 	.func		= bpf_perf_event_read,
848 	.gpl_only	= true,
849 	.ret_type	= RET_INTEGER,
850 	.arg1_type	= ARG_CONST_MAP_PTR,
851 	.arg2_type	= ARG_ANYTHING,
852 };
853 
854 BPF_CALL_4(bpf_perf_event_read_value, struct bpf_map *, map, u64, flags,
855 	   struct bpf_perf_event_value *, buf, u32, size)
856 {
857 	int err = -EINVAL;
858 
859 	if (unlikely(size != sizeof(struct bpf_perf_event_value)))
860 		goto clear;
861 	err = get_map_perf_counter(map, flags, &buf->counter, &buf->enabled,
862 				   &buf->running);
863 	if (unlikely(err))
864 		goto clear;
865 	return 0;
866 clear:
867 	memset(buf, 0, size);
868 	return err;
869 }
870 
871 static const struct bpf_func_proto bpf_perf_event_read_value_proto = {
872 	.func		= bpf_perf_event_read_value,
873 	.gpl_only	= true,
874 	.ret_type	= RET_INTEGER,
875 	.arg1_type	= ARG_CONST_MAP_PTR,
876 	.arg2_type	= ARG_ANYTHING,
877 	.arg3_type	= ARG_PTR_TO_UNINIT_MEM,
878 	.arg4_type	= ARG_CONST_SIZE,
879 };
880 
881 static __always_inline u64
882 __bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map,
883 			u64 flags, struct perf_sample_data *sd)
884 {
885 	struct bpf_array *array = container_of(map, struct bpf_array, map);
886 	unsigned int cpu = smp_processor_id();
887 	u64 index = flags & BPF_F_INDEX_MASK;
888 	struct bpf_event_entry *ee;
889 	struct perf_event *event;
890 
891 	if (index == BPF_F_CURRENT_CPU)
892 		index = cpu;
893 	if (unlikely(index >= array->map.max_entries))
894 		return -E2BIG;
895 
896 	ee = READ_ONCE(array->ptrs[index]);
897 	if (!ee)
898 		return -ENOENT;
899 
900 	event = ee->event;
901 	if (unlikely(event->attr.type != PERF_TYPE_SOFTWARE ||
902 		     event->attr.config != PERF_COUNT_SW_BPF_OUTPUT))
903 		return -EINVAL;
904 
905 	if (unlikely(event->oncpu != cpu))
906 		return -EOPNOTSUPP;
907 
908 	return perf_event_output(event, sd, regs);
909 }
910 
911 /*
912  * Support executing tracepoints in normal, irq, and nmi context that each call
913  * bpf_perf_event_output
914  */
915 struct bpf_trace_sample_data {
916 	struct perf_sample_data sds[3];
917 };
918 
919 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_trace_sds);
920 static DEFINE_PER_CPU(int, bpf_trace_nest_level);
921 BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map,
922 	   u64, flags, void *, data, u64, size)
923 {
924 	struct bpf_trace_sample_data *sds = this_cpu_ptr(&bpf_trace_sds);
925 	int nest_level = this_cpu_inc_return(bpf_trace_nest_level);
926 	struct perf_raw_record raw = {
927 		.frag = {
928 			.size = size,
929 			.data = data,
930 		},
931 	};
932 	struct perf_sample_data *sd;
933 	int err;
934 
935 	if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(sds->sds))) {
936 		err = -EBUSY;
937 		goto out;
938 	}
939 
940 	sd = &sds->sds[nest_level - 1];
941 
942 	if (unlikely(flags & ~(BPF_F_INDEX_MASK))) {
943 		err = -EINVAL;
944 		goto out;
945 	}
946 
947 	perf_sample_data_init(sd, 0, 0);
948 	sd->raw = &raw;
949 
950 	err = __bpf_perf_event_output(regs, map, flags, sd);
951 
952 out:
953 	this_cpu_dec(bpf_trace_nest_level);
954 	return err;
955 }
956 
957 static const struct bpf_func_proto bpf_perf_event_output_proto = {
958 	.func		= bpf_perf_event_output,
959 	.gpl_only	= true,
960 	.ret_type	= RET_INTEGER,
961 	.arg1_type	= ARG_PTR_TO_CTX,
962 	.arg2_type	= ARG_CONST_MAP_PTR,
963 	.arg3_type	= ARG_ANYTHING,
964 	.arg4_type	= ARG_PTR_TO_MEM,
965 	.arg5_type	= ARG_CONST_SIZE_OR_ZERO,
966 };
967 
968 static DEFINE_PER_CPU(int, bpf_event_output_nest_level);
969 struct bpf_nested_pt_regs {
970 	struct pt_regs regs[3];
971 };
972 static DEFINE_PER_CPU(struct bpf_nested_pt_regs, bpf_pt_regs);
973 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_misc_sds);
974 
975 u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
976 		     void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy)
977 {
978 	int nest_level = this_cpu_inc_return(bpf_event_output_nest_level);
979 	struct perf_raw_frag frag = {
980 		.copy		= ctx_copy,
981 		.size		= ctx_size,
982 		.data		= ctx,
983 	};
984 	struct perf_raw_record raw = {
985 		.frag = {
986 			{
987 				.next	= ctx_size ? &frag : NULL,
988 			},
989 			.size	= meta_size,
990 			.data	= meta,
991 		},
992 	};
993 	struct perf_sample_data *sd;
994 	struct pt_regs *regs;
995 	u64 ret;
996 
997 	if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(bpf_misc_sds.sds))) {
998 		ret = -EBUSY;
999 		goto out;
1000 	}
1001 	sd = this_cpu_ptr(&bpf_misc_sds.sds[nest_level - 1]);
1002 	regs = this_cpu_ptr(&bpf_pt_regs.regs[nest_level - 1]);
1003 
1004 	perf_fetch_caller_regs(regs);
1005 	perf_sample_data_init(sd, 0, 0);
1006 	sd->raw = &raw;
1007 
1008 	ret = __bpf_perf_event_output(regs, map, flags, sd);
1009 out:
1010 	this_cpu_dec(bpf_event_output_nest_level);
1011 	return ret;
1012 }
1013 
1014 BPF_CALL_0(bpf_get_current_task)
1015 {
1016 	return (long) current;
1017 }
1018 
1019 const struct bpf_func_proto bpf_get_current_task_proto = {
1020 	.func		= bpf_get_current_task,
1021 	.gpl_only	= true,
1022 	.ret_type	= RET_INTEGER,
1023 };
1024 
1025 BPF_CALL_2(bpf_current_task_under_cgroup, struct bpf_map *, map, u32, idx)
1026 {
1027 	struct bpf_array *array = container_of(map, struct bpf_array, map);
1028 	struct cgroup *cgrp;
1029 
1030 	if (unlikely(idx >= array->map.max_entries))
1031 		return -E2BIG;
1032 
1033 	cgrp = READ_ONCE(array->ptrs[idx]);
1034 	if (unlikely(!cgrp))
1035 		return -EAGAIN;
1036 
1037 	return task_under_cgroup_hierarchy(current, cgrp);
1038 }
1039 
1040 static const struct bpf_func_proto bpf_current_task_under_cgroup_proto = {
1041 	.func           = bpf_current_task_under_cgroup,
1042 	.gpl_only       = false,
1043 	.ret_type       = RET_INTEGER,
1044 	.arg1_type      = ARG_CONST_MAP_PTR,
1045 	.arg2_type      = ARG_ANYTHING,
1046 };
1047 
1048 struct send_signal_irq_work {
1049 	struct irq_work irq_work;
1050 	struct task_struct *task;
1051 	u32 sig;
1052 	enum pid_type type;
1053 };
1054 
1055 static DEFINE_PER_CPU(struct send_signal_irq_work, send_signal_work);
1056 
1057 static void do_bpf_send_signal(struct irq_work *entry)
1058 {
1059 	struct send_signal_irq_work *work;
1060 
1061 	work = container_of(entry, struct send_signal_irq_work, irq_work);
1062 	group_send_sig_info(work->sig, SEND_SIG_PRIV, work->task, work->type);
1063 }
1064 
1065 static int bpf_send_signal_common(u32 sig, enum pid_type type)
1066 {
1067 	struct send_signal_irq_work *work = NULL;
1068 
1069 	/* Similar to bpf_probe_write_user, task needs to be
1070 	 * in a sound condition and kernel memory access be
1071 	 * permitted in order to send signal to the current
1072 	 * task.
1073 	 */
1074 	if (unlikely(current->flags & (PF_KTHREAD | PF_EXITING)))
1075 		return -EPERM;
1076 	if (unlikely(uaccess_kernel()))
1077 		return -EPERM;
1078 	if (unlikely(!nmi_uaccess_okay()))
1079 		return -EPERM;
1080 
1081 	if (irqs_disabled()) {
1082 		/* Do an early check on signal validity. Otherwise,
1083 		 * the error is lost in deferred irq_work.
1084 		 */
1085 		if (unlikely(!valid_signal(sig)))
1086 			return -EINVAL;
1087 
1088 		work = this_cpu_ptr(&send_signal_work);
1089 		if (atomic_read(&work->irq_work.flags) & IRQ_WORK_BUSY)
1090 			return -EBUSY;
1091 
1092 		/* Add the current task, which is the target of sending signal,
1093 		 * to the irq_work. The current task may change when queued
1094 		 * irq works get executed.
1095 		 */
1096 		work->task = current;
1097 		work->sig = sig;
1098 		work->type = type;
1099 		irq_work_queue(&work->irq_work);
1100 		return 0;
1101 	}
1102 
1103 	return group_send_sig_info(sig, SEND_SIG_PRIV, current, type);
1104 }
1105 
1106 BPF_CALL_1(bpf_send_signal, u32, sig)
1107 {
1108 	return bpf_send_signal_common(sig, PIDTYPE_TGID);
1109 }
1110 
1111 static const struct bpf_func_proto bpf_send_signal_proto = {
1112 	.func		= bpf_send_signal,
1113 	.gpl_only	= false,
1114 	.ret_type	= RET_INTEGER,
1115 	.arg1_type	= ARG_ANYTHING,
1116 };
1117 
1118 BPF_CALL_1(bpf_send_signal_thread, u32, sig)
1119 {
1120 	return bpf_send_signal_common(sig, PIDTYPE_PID);
1121 }
1122 
1123 static const struct bpf_func_proto bpf_send_signal_thread_proto = {
1124 	.func		= bpf_send_signal_thread,
1125 	.gpl_only	= false,
1126 	.ret_type	= RET_INTEGER,
1127 	.arg1_type	= ARG_ANYTHING,
1128 };
1129 
1130 BPF_CALL_3(bpf_d_path, struct path *, path, char *, buf, u32, sz)
1131 {
1132 	long len;
1133 	char *p;
1134 
1135 	if (!sz)
1136 		return 0;
1137 
1138 	p = d_path(path, buf, sz);
1139 	if (IS_ERR(p)) {
1140 		len = PTR_ERR(p);
1141 	} else {
1142 		len = buf + sz - p;
1143 		memmove(buf, p, len);
1144 	}
1145 
1146 	return len;
1147 }
1148 
1149 BTF_SET_START(btf_allowlist_d_path)
1150 #ifdef CONFIG_SECURITY
1151 BTF_ID(func, security_file_permission)
1152 BTF_ID(func, security_inode_getattr)
1153 BTF_ID(func, security_file_open)
1154 #endif
1155 #ifdef CONFIG_SECURITY_PATH
1156 BTF_ID(func, security_path_truncate)
1157 #endif
1158 BTF_ID(func, vfs_truncate)
1159 BTF_ID(func, vfs_fallocate)
1160 BTF_ID(func, dentry_open)
1161 BTF_ID(func, vfs_getattr)
1162 BTF_ID(func, filp_close)
1163 BTF_SET_END(btf_allowlist_d_path)
1164 
1165 static bool bpf_d_path_allowed(const struct bpf_prog *prog)
1166 {
1167 	return btf_id_set_contains(&btf_allowlist_d_path, prog->aux->attach_btf_id);
1168 }
1169 
1170 BTF_ID_LIST_SINGLE(bpf_d_path_btf_ids, struct, path)
1171 
1172 static const struct bpf_func_proto bpf_d_path_proto = {
1173 	.func		= bpf_d_path,
1174 	.gpl_only	= false,
1175 	.ret_type	= RET_INTEGER,
1176 	.arg1_type	= ARG_PTR_TO_BTF_ID,
1177 	.arg1_btf_id	= &bpf_d_path_btf_ids[0],
1178 	.arg2_type	= ARG_PTR_TO_MEM,
1179 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
1180 	.allowed	= bpf_d_path_allowed,
1181 };
1182 
1183 #define BTF_F_ALL	(BTF_F_COMPACT  | BTF_F_NONAME | \
1184 			 BTF_F_PTR_RAW | BTF_F_ZERO)
1185 
1186 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size,
1187 				  u64 flags, const struct btf **btf,
1188 				  s32 *btf_id)
1189 {
1190 	const struct btf_type *t;
1191 
1192 	if (unlikely(flags & ~(BTF_F_ALL)))
1193 		return -EINVAL;
1194 
1195 	if (btf_ptr_size != sizeof(struct btf_ptr))
1196 		return -EINVAL;
1197 
1198 	*btf = bpf_get_btf_vmlinux();
1199 
1200 	if (IS_ERR_OR_NULL(*btf))
1201 		return PTR_ERR(*btf);
1202 
1203 	if (ptr->type_id > 0)
1204 		*btf_id = ptr->type_id;
1205 	else
1206 		return -EINVAL;
1207 
1208 	if (*btf_id > 0)
1209 		t = btf_type_by_id(*btf, *btf_id);
1210 	if (*btf_id <= 0 || !t)
1211 		return -ENOENT;
1212 
1213 	return 0;
1214 }
1215 
1216 BPF_CALL_5(bpf_snprintf_btf, char *, str, u32, str_size, struct btf_ptr *, ptr,
1217 	   u32, btf_ptr_size, u64, flags)
1218 {
1219 	const struct btf *btf;
1220 	s32 btf_id;
1221 	int ret;
1222 
1223 	ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id);
1224 	if (ret)
1225 		return ret;
1226 
1227 	return btf_type_snprintf_show(btf, btf_id, ptr->ptr, str, str_size,
1228 				      flags);
1229 }
1230 
1231 const struct bpf_func_proto bpf_snprintf_btf_proto = {
1232 	.func		= bpf_snprintf_btf,
1233 	.gpl_only	= false,
1234 	.ret_type	= RET_INTEGER,
1235 	.arg1_type	= ARG_PTR_TO_MEM,
1236 	.arg2_type	= ARG_CONST_SIZE,
1237 	.arg3_type	= ARG_PTR_TO_MEM,
1238 	.arg4_type	= ARG_CONST_SIZE,
1239 	.arg5_type	= ARG_ANYTHING,
1240 };
1241 
1242 const struct bpf_func_proto *
1243 bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1244 {
1245 	switch (func_id) {
1246 	case BPF_FUNC_map_lookup_elem:
1247 		return &bpf_map_lookup_elem_proto;
1248 	case BPF_FUNC_map_update_elem:
1249 		return &bpf_map_update_elem_proto;
1250 	case BPF_FUNC_map_delete_elem:
1251 		return &bpf_map_delete_elem_proto;
1252 	case BPF_FUNC_map_push_elem:
1253 		return &bpf_map_push_elem_proto;
1254 	case BPF_FUNC_map_pop_elem:
1255 		return &bpf_map_pop_elem_proto;
1256 	case BPF_FUNC_map_peek_elem:
1257 		return &bpf_map_peek_elem_proto;
1258 	case BPF_FUNC_ktime_get_ns:
1259 		return &bpf_ktime_get_ns_proto;
1260 	case BPF_FUNC_ktime_get_boot_ns:
1261 		return &bpf_ktime_get_boot_ns_proto;
1262 	case BPF_FUNC_tail_call:
1263 		return &bpf_tail_call_proto;
1264 	case BPF_FUNC_get_current_pid_tgid:
1265 		return &bpf_get_current_pid_tgid_proto;
1266 	case BPF_FUNC_get_current_task:
1267 		return &bpf_get_current_task_proto;
1268 	case BPF_FUNC_get_current_uid_gid:
1269 		return &bpf_get_current_uid_gid_proto;
1270 	case BPF_FUNC_get_current_comm:
1271 		return &bpf_get_current_comm_proto;
1272 	case BPF_FUNC_trace_printk:
1273 		return bpf_get_trace_printk_proto();
1274 	case BPF_FUNC_get_smp_processor_id:
1275 		return &bpf_get_smp_processor_id_proto;
1276 	case BPF_FUNC_get_numa_node_id:
1277 		return &bpf_get_numa_node_id_proto;
1278 	case BPF_FUNC_perf_event_read:
1279 		return &bpf_perf_event_read_proto;
1280 	case BPF_FUNC_probe_write_user:
1281 		return bpf_get_probe_write_proto();
1282 	case BPF_FUNC_current_task_under_cgroup:
1283 		return &bpf_current_task_under_cgroup_proto;
1284 	case BPF_FUNC_get_prandom_u32:
1285 		return &bpf_get_prandom_u32_proto;
1286 	case BPF_FUNC_probe_read_user:
1287 		return &bpf_probe_read_user_proto;
1288 	case BPF_FUNC_probe_read_kernel:
1289 		return &bpf_probe_read_kernel_proto;
1290 	case BPF_FUNC_probe_read_user_str:
1291 		return &bpf_probe_read_user_str_proto;
1292 	case BPF_FUNC_probe_read_kernel_str:
1293 		return &bpf_probe_read_kernel_str_proto;
1294 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
1295 	case BPF_FUNC_probe_read:
1296 		return &bpf_probe_read_compat_proto;
1297 	case BPF_FUNC_probe_read_str:
1298 		return &bpf_probe_read_compat_str_proto;
1299 #endif
1300 #ifdef CONFIG_CGROUPS
1301 	case BPF_FUNC_get_current_cgroup_id:
1302 		return &bpf_get_current_cgroup_id_proto;
1303 #endif
1304 	case BPF_FUNC_send_signal:
1305 		return &bpf_send_signal_proto;
1306 	case BPF_FUNC_send_signal_thread:
1307 		return &bpf_send_signal_thread_proto;
1308 	case BPF_FUNC_perf_event_read_value:
1309 		return &bpf_perf_event_read_value_proto;
1310 	case BPF_FUNC_get_ns_current_pid_tgid:
1311 		return &bpf_get_ns_current_pid_tgid_proto;
1312 	case BPF_FUNC_ringbuf_output:
1313 		return &bpf_ringbuf_output_proto;
1314 	case BPF_FUNC_ringbuf_reserve:
1315 		return &bpf_ringbuf_reserve_proto;
1316 	case BPF_FUNC_ringbuf_submit:
1317 		return &bpf_ringbuf_submit_proto;
1318 	case BPF_FUNC_ringbuf_discard:
1319 		return &bpf_ringbuf_discard_proto;
1320 	case BPF_FUNC_ringbuf_query:
1321 		return &bpf_ringbuf_query_proto;
1322 	case BPF_FUNC_jiffies64:
1323 		return &bpf_jiffies64_proto;
1324 	case BPF_FUNC_get_task_stack:
1325 		return &bpf_get_task_stack_proto;
1326 	case BPF_FUNC_copy_from_user:
1327 		return prog->aux->sleepable ? &bpf_copy_from_user_proto : NULL;
1328 	case BPF_FUNC_snprintf_btf:
1329 		return &bpf_snprintf_btf_proto;
1330 	case BPF_FUNC_bpf_per_cpu_ptr:
1331 		return &bpf_per_cpu_ptr_proto;
1332 	case BPF_FUNC_bpf_this_cpu_ptr:
1333 		return &bpf_this_cpu_ptr_proto;
1334 	default:
1335 		return NULL;
1336 	}
1337 }
1338 
1339 static const struct bpf_func_proto *
1340 kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1341 {
1342 	switch (func_id) {
1343 	case BPF_FUNC_perf_event_output:
1344 		return &bpf_perf_event_output_proto;
1345 	case BPF_FUNC_get_stackid:
1346 		return &bpf_get_stackid_proto;
1347 	case BPF_FUNC_get_stack:
1348 		return &bpf_get_stack_proto;
1349 #ifdef CONFIG_BPF_KPROBE_OVERRIDE
1350 	case BPF_FUNC_override_return:
1351 		return &bpf_override_return_proto;
1352 #endif
1353 	default:
1354 		return bpf_tracing_func_proto(func_id, prog);
1355 	}
1356 }
1357 
1358 /* bpf+kprobe programs can access fields of 'struct pt_regs' */
1359 static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
1360 					const struct bpf_prog *prog,
1361 					struct bpf_insn_access_aux *info)
1362 {
1363 	if (off < 0 || off >= sizeof(struct pt_regs))
1364 		return false;
1365 	if (type != BPF_READ)
1366 		return false;
1367 	if (off % size != 0)
1368 		return false;
1369 	/*
1370 	 * Assertion for 32 bit to make sure last 8 byte access
1371 	 * (BPF_DW) to the last 4 byte member is disallowed.
1372 	 */
1373 	if (off + size > sizeof(struct pt_regs))
1374 		return false;
1375 
1376 	return true;
1377 }
1378 
1379 const struct bpf_verifier_ops kprobe_verifier_ops = {
1380 	.get_func_proto  = kprobe_prog_func_proto,
1381 	.is_valid_access = kprobe_prog_is_valid_access,
1382 };
1383 
1384 const struct bpf_prog_ops kprobe_prog_ops = {
1385 };
1386 
1387 BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map,
1388 	   u64, flags, void *, data, u64, size)
1389 {
1390 	struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1391 
1392 	/*
1393 	 * r1 points to perf tracepoint buffer where first 8 bytes are hidden
1394 	 * from bpf program and contain a pointer to 'struct pt_regs'. Fetch it
1395 	 * from there and call the same bpf_perf_event_output() helper inline.
1396 	 */
1397 	return ____bpf_perf_event_output(regs, map, flags, data, size);
1398 }
1399 
1400 static const struct bpf_func_proto bpf_perf_event_output_proto_tp = {
1401 	.func		= bpf_perf_event_output_tp,
1402 	.gpl_only	= true,
1403 	.ret_type	= RET_INTEGER,
1404 	.arg1_type	= ARG_PTR_TO_CTX,
1405 	.arg2_type	= ARG_CONST_MAP_PTR,
1406 	.arg3_type	= ARG_ANYTHING,
1407 	.arg4_type	= ARG_PTR_TO_MEM,
1408 	.arg5_type	= ARG_CONST_SIZE_OR_ZERO,
1409 };
1410 
1411 BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map,
1412 	   u64, flags)
1413 {
1414 	struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1415 
1416 	/*
1417 	 * Same comment as in bpf_perf_event_output_tp(), only that this time
1418 	 * the other helper's function body cannot be inlined due to being
1419 	 * external, thus we need to call raw helper function.
1420 	 */
1421 	return bpf_get_stackid((unsigned long) regs, (unsigned long) map,
1422 			       flags, 0, 0);
1423 }
1424 
1425 static const struct bpf_func_proto bpf_get_stackid_proto_tp = {
1426 	.func		= bpf_get_stackid_tp,
1427 	.gpl_only	= true,
1428 	.ret_type	= RET_INTEGER,
1429 	.arg1_type	= ARG_PTR_TO_CTX,
1430 	.arg2_type	= ARG_CONST_MAP_PTR,
1431 	.arg3_type	= ARG_ANYTHING,
1432 };
1433 
1434 BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size,
1435 	   u64, flags)
1436 {
1437 	struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1438 
1439 	return bpf_get_stack((unsigned long) regs, (unsigned long) buf,
1440 			     (unsigned long) size, flags, 0);
1441 }
1442 
1443 static const struct bpf_func_proto bpf_get_stack_proto_tp = {
1444 	.func		= bpf_get_stack_tp,
1445 	.gpl_only	= true,
1446 	.ret_type	= RET_INTEGER,
1447 	.arg1_type	= ARG_PTR_TO_CTX,
1448 	.arg2_type	= ARG_PTR_TO_UNINIT_MEM,
1449 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
1450 	.arg4_type	= ARG_ANYTHING,
1451 };
1452 
1453 static const struct bpf_func_proto *
1454 tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1455 {
1456 	switch (func_id) {
1457 	case BPF_FUNC_perf_event_output:
1458 		return &bpf_perf_event_output_proto_tp;
1459 	case BPF_FUNC_get_stackid:
1460 		return &bpf_get_stackid_proto_tp;
1461 	case BPF_FUNC_get_stack:
1462 		return &bpf_get_stack_proto_tp;
1463 	default:
1464 		return bpf_tracing_func_proto(func_id, prog);
1465 	}
1466 }
1467 
1468 static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type,
1469 				    const struct bpf_prog *prog,
1470 				    struct bpf_insn_access_aux *info)
1471 {
1472 	if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE)
1473 		return false;
1474 	if (type != BPF_READ)
1475 		return false;
1476 	if (off % size != 0)
1477 		return false;
1478 
1479 	BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(__u64));
1480 	return true;
1481 }
1482 
1483 const struct bpf_verifier_ops tracepoint_verifier_ops = {
1484 	.get_func_proto  = tp_prog_func_proto,
1485 	.is_valid_access = tp_prog_is_valid_access,
1486 };
1487 
1488 const struct bpf_prog_ops tracepoint_prog_ops = {
1489 };
1490 
1491 BPF_CALL_3(bpf_perf_prog_read_value, struct bpf_perf_event_data_kern *, ctx,
1492 	   struct bpf_perf_event_value *, buf, u32, size)
1493 {
1494 	int err = -EINVAL;
1495 
1496 	if (unlikely(size != sizeof(struct bpf_perf_event_value)))
1497 		goto clear;
1498 	err = perf_event_read_local(ctx->event, &buf->counter, &buf->enabled,
1499 				    &buf->running);
1500 	if (unlikely(err))
1501 		goto clear;
1502 	return 0;
1503 clear:
1504 	memset(buf, 0, size);
1505 	return err;
1506 }
1507 
1508 static const struct bpf_func_proto bpf_perf_prog_read_value_proto = {
1509          .func           = bpf_perf_prog_read_value,
1510          .gpl_only       = true,
1511          .ret_type       = RET_INTEGER,
1512          .arg1_type      = ARG_PTR_TO_CTX,
1513          .arg2_type      = ARG_PTR_TO_UNINIT_MEM,
1514          .arg3_type      = ARG_CONST_SIZE,
1515 };
1516 
1517 BPF_CALL_4(bpf_read_branch_records, struct bpf_perf_event_data_kern *, ctx,
1518 	   void *, buf, u32, size, u64, flags)
1519 {
1520 #ifndef CONFIG_X86
1521 	return -ENOENT;
1522 #else
1523 	static const u32 br_entry_size = sizeof(struct perf_branch_entry);
1524 	struct perf_branch_stack *br_stack = ctx->data->br_stack;
1525 	u32 to_copy;
1526 
1527 	if (unlikely(flags & ~BPF_F_GET_BRANCH_RECORDS_SIZE))
1528 		return -EINVAL;
1529 
1530 	if (unlikely(!br_stack))
1531 		return -EINVAL;
1532 
1533 	if (flags & BPF_F_GET_BRANCH_RECORDS_SIZE)
1534 		return br_stack->nr * br_entry_size;
1535 
1536 	if (!buf || (size % br_entry_size != 0))
1537 		return -EINVAL;
1538 
1539 	to_copy = min_t(u32, br_stack->nr * br_entry_size, size);
1540 	memcpy(buf, br_stack->entries, to_copy);
1541 
1542 	return to_copy;
1543 #endif
1544 }
1545 
1546 static const struct bpf_func_proto bpf_read_branch_records_proto = {
1547 	.func           = bpf_read_branch_records,
1548 	.gpl_only       = true,
1549 	.ret_type       = RET_INTEGER,
1550 	.arg1_type      = ARG_PTR_TO_CTX,
1551 	.arg2_type      = ARG_PTR_TO_MEM_OR_NULL,
1552 	.arg3_type      = ARG_CONST_SIZE_OR_ZERO,
1553 	.arg4_type      = ARG_ANYTHING,
1554 };
1555 
1556 static const struct bpf_func_proto *
1557 pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1558 {
1559 	switch (func_id) {
1560 	case BPF_FUNC_perf_event_output:
1561 		return &bpf_perf_event_output_proto_tp;
1562 	case BPF_FUNC_get_stackid:
1563 		return &bpf_get_stackid_proto_pe;
1564 	case BPF_FUNC_get_stack:
1565 		return &bpf_get_stack_proto_pe;
1566 	case BPF_FUNC_perf_prog_read_value:
1567 		return &bpf_perf_prog_read_value_proto;
1568 	case BPF_FUNC_read_branch_records:
1569 		return &bpf_read_branch_records_proto;
1570 	default:
1571 		return bpf_tracing_func_proto(func_id, prog);
1572 	}
1573 }
1574 
1575 /*
1576  * bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp
1577  * to avoid potential recursive reuse issue when/if tracepoints are added
1578  * inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack.
1579  *
1580  * Since raw tracepoints run despite bpf_prog_active, support concurrent usage
1581  * in normal, irq, and nmi context.
1582  */
1583 struct bpf_raw_tp_regs {
1584 	struct pt_regs regs[3];
1585 };
1586 static DEFINE_PER_CPU(struct bpf_raw_tp_regs, bpf_raw_tp_regs);
1587 static DEFINE_PER_CPU(int, bpf_raw_tp_nest_level);
1588 static struct pt_regs *get_bpf_raw_tp_regs(void)
1589 {
1590 	struct bpf_raw_tp_regs *tp_regs = this_cpu_ptr(&bpf_raw_tp_regs);
1591 	int nest_level = this_cpu_inc_return(bpf_raw_tp_nest_level);
1592 
1593 	if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(tp_regs->regs))) {
1594 		this_cpu_dec(bpf_raw_tp_nest_level);
1595 		return ERR_PTR(-EBUSY);
1596 	}
1597 
1598 	return &tp_regs->regs[nest_level - 1];
1599 }
1600 
1601 static void put_bpf_raw_tp_regs(void)
1602 {
1603 	this_cpu_dec(bpf_raw_tp_nest_level);
1604 }
1605 
1606 BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args,
1607 	   struct bpf_map *, map, u64, flags, void *, data, u64, size)
1608 {
1609 	struct pt_regs *regs = get_bpf_raw_tp_regs();
1610 	int ret;
1611 
1612 	if (IS_ERR(regs))
1613 		return PTR_ERR(regs);
1614 
1615 	perf_fetch_caller_regs(regs);
1616 	ret = ____bpf_perf_event_output(regs, map, flags, data, size);
1617 
1618 	put_bpf_raw_tp_regs();
1619 	return ret;
1620 }
1621 
1622 static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = {
1623 	.func		= bpf_perf_event_output_raw_tp,
1624 	.gpl_only	= true,
1625 	.ret_type	= RET_INTEGER,
1626 	.arg1_type	= ARG_PTR_TO_CTX,
1627 	.arg2_type	= ARG_CONST_MAP_PTR,
1628 	.arg3_type	= ARG_ANYTHING,
1629 	.arg4_type	= ARG_PTR_TO_MEM,
1630 	.arg5_type	= ARG_CONST_SIZE_OR_ZERO,
1631 };
1632 
1633 extern const struct bpf_func_proto bpf_skb_output_proto;
1634 extern const struct bpf_func_proto bpf_xdp_output_proto;
1635 
1636 BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args,
1637 	   struct bpf_map *, map, u64, flags)
1638 {
1639 	struct pt_regs *regs = get_bpf_raw_tp_regs();
1640 	int ret;
1641 
1642 	if (IS_ERR(regs))
1643 		return PTR_ERR(regs);
1644 
1645 	perf_fetch_caller_regs(regs);
1646 	/* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */
1647 	ret = bpf_get_stackid((unsigned long) regs, (unsigned long) map,
1648 			      flags, 0, 0);
1649 	put_bpf_raw_tp_regs();
1650 	return ret;
1651 }
1652 
1653 static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = {
1654 	.func		= bpf_get_stackid_raw_tp,
1655 	.gpl_only	= true,
1656 	.ret_type	= RET_INTEGER,
1657 	.arg1_type	= ARG_PTR_TO_CTX,
1658 	.arg2_type	= ARG_CONST_MAP_PTR,
1659 	.arg3_type	= ARG_ANYTHING,
1660 };
1661 
1662 BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args,
1663 	   void *, buf, u32, size, u64, flags)
1664 {
1665 	struct pt_regs *regs = get_bpf_raw_tp_regs();
1666 	int ret;
1667 
1668 	if (IS_ERR(regs))
1669 		return PTR_ERR(regs);
1670 
1671 	perf_fetch_caller_regs(regs);
1672 	ret = bpf_get_stack((unsigned long) regs, (unsigned long) buf,
1673 			    (unsigned long) size, flags, 0);
1674 	put_bpf_raw_tp_regs();
1675 	return ret;
1676 }
1677 
1678 static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = {
1679 	.func		= bpf_get_stack_raw_tp,
1680 	.gpl_only	= true,
1681 	.ret_type	= RET_INTEGER,
1682 	.arg1_type	= ARG_PTR_TO_CTX,
1683 	.arg2_type	= ARG_PTR_TO_MEM,
1684 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
1685 	.arg4_type	= ARG_ANYTHING,
1686 };
1687 
1688 static const struct bpf_func_proto *
1689 raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1690 {
1691 	switch (func_id) {
1692 	case BPF_FUNC_perf_event_output:
1693 		return &bpf_perf_event_output_proto_raw_tp;
1694 	case BPF_FUNC_get_stackid:
1695 		return &bpf_get_stackid_proto_raw_tp;
1696 	case BPF_FUNC_get_stack:
1697 		return &bpf_get_stack_proto_raw_tp;
1698 	default:
1699 		return bpf_tracing_func_proto(func_id, prog);
1700 	}
1701 }
1702 
1703 const struct bpf_func_proto *
1704 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1705 {
1706 	switch (func_id) {
1707 #ifdef CONFIG_NET
1708 	case BPF_FUNC_skb_output:
1709 		return &bpf_skb_output_proto;
1710 	case BPF_FUNC_xdp_output:
1711 		return &bpf_xdp_output_proto;
1712 	case BPF_FUNC_skc_to_tcp6_sock:
1713 		return &bpf_skc_to_tcp6_sock_proto;
1714 	case BPF_FUNC_skc_to_tcp_sock:
1715 		return &bpf_skc_to_tcp_sock_proto;
1716 	case BPF_FUNC_skc_to_tcp_timewait_sock:
1717 		return &bpf_skc_to_tcp_timewait_sock_proto;
1718 	case BPF_FUNC_skc_to_tcp_request_sock:
1719 		return &bpf_skc_to_tcp_request_sock_proto;
1720 	case BPF_FUNC_skc_to_udp6_sock:
1721 		return &bpf_skc_to_udp6_sock_proto;
1722 #endif
1723 	case BPF_FUNC_seq_printf:
1724 		return prog->expected_attach_type == BPF_TRACE_ITER ?
1725 		       &bpf_seq_printf_proto :
1726 		       NULL;
1727 	case BPF_FUNC_seq_write:
1728 		return prog->expected_attach_type == BPF_TRACE_ITER ?
1729 		       &bpf_seq_write_proto :
1730 		       NULL;
1731 	case BPF_FUNC_seq_printf_btf:
1732 		return prog->expected_attach_type == BPF_TRACE_ITER ?
1733 		       &bpf_seq_printf_btf_proto :
1734 		       NULL;
1735 	case BPF_FUNC_d_path:
1736 		return &bpf_d_path_proto;
1737 	default:
1738 		return raw_tp_prog_func_proto(func_id, prog);
1739 	}
1740 }
1741 
1742 static bool raw_tp_prog_is_valid_access(int off, int size,
1743 					enum bpf_access_type type,
1744 					const struct bpf_prog *prog,
1745 					struct bpf_insn_access_aux *info)
1746 {
1747 	if (off < 0 || off >= sizeof(__u64) * MAX_BPF_FUNC_ARGS)
1748 		return false;
1749 	if (type != BPF_READ)
1750 		return false;
1751 	if (off % size != 0)
1752 		return false;
1753 	return true;
1754 }
1755 
1756 static bool tracing_prog_is_valid_access(int off, int size,
1757 					 enum bpf_access_type type,
1758 					 const struct bpf_prog *prog,
1759 					 struct bpf_insn_access_aux *info)
1760 {
1761 	if (off < 0 || off >= sizeof(__u64) * MAX_BPF_FUNC_ARGS)
1762 		return false;
1763 	if (type != BPF_READ)
1764 		return false;
1765 	if (off % size != 0)
1766 		return false;
1767 	return btf_ctx_access(off, size, type, prog, info);
1768 }
1769 
1770 int __weak bpf_prog_test_run_tracing(struct bpf_prog *prog,
1771 				     const union bpf_attr *kattr,
1772 				     union bpf_attr __user *uattr)
1773 {
1774 	return -ENOTSUPP;
1775 }
1776 
1777 const struct bpf_verifier_ops raw_tracepoint_verifier_ops = {
1778 	.get_func_proto  = raw_tp_prog_func_proto,
1779 	.is_valid_access = raw_tp_prog_is_valid_access,
1780 };
1781 
1782 const struct bpf_prog_ops raw_tracepoint_prog_ops = {
1783 #ifdef CONFIG_NET
1784 	.test_run = bpf_prog_test_run_raw_tp,
1785 #endif
1786 };
1787 
1788 const struct bpf_verifier_ops tracing_verifier_ops = {
1789 	.get_func_proto  = tracing_prog_func_proto,
1790 	.is_valid_access = tracing_prog_is_valid_access,
1791 };
1792 
1793 const struct bpf_prog_ops tracing_prog_ops = {
1794 	.test_run = bpf_prog_test_run_tracing,
1795 };
1796 
1797 static bool raw_tp_writable_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) {
1803 		if (size != sizeof(u64) || type != BPF_READ)
1804 			return false;
1805 		info->reg_type = PTR_TO_TP_BUFFER;
1806 	}
1807 	return raw_tp_prog_is_valid_access(off, size, type, prog, info);
1808 }
1809 
1810 const struct bpf_verifier_ops raw_tracepoint_writable_verifier_ops = {
1811 	.get_func_proto  = raw_tp_prog_func_proto,
1812 	.is_valid_access = raw_tp_writable_prog_is_valid_access,
1813 };
1814 
1815 const struct bpf_prog_ops raw_tracepoint_writable_prog_ops = {
1816 };
1817 
1818 static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
1819 				    const struct bpf_prog *prog,
1820 				    struct bpf_insn_access_aux *info)
1821 {
1822 	const int size_u64 = sizeof(u64);
1823 
1824 	if (off < 0 || off >= sizeof(struct bpf_perf_event_data))
1825 		return false;
1826 	if (type != BPF_READ)
1827 		return false;
1828 	if (off % size != 0) {
1829 		if (sizeof(unsigned long) != 4)
1830 			return false;
1831 		if (size != 8)
1832 			return false;
1833 		if (off % size != 4)
1834 			return false;
1835 	}
1836 
1837 	switch (off) {
1838 	case bpf_ctx_range(struct bpf_perf_event_data, sample_period):
1839 		bpf_ctx_record_field_size(info, size_u64);
1840 		if (!bpf_ctx_narrow_access_ok(off, size, size_u64))
1841 			return false;
1842 		break;
1843 	case bpf_ctx_range(struct bpf_perf_event_data, addr):
1844 		bpf_ctx_record_field_size(info, size_u64);
1845 		if (!bpf_ctx_narrow_access_ok(off, size, size_u64))
1846 			return false;
1847 		break;
1848 	default:
1849 		if (size != sizeof(long))
1850 			return false;
1851 	}
1852 
1853 	return true;
1854 }
1855 
1856 static u32 pe_prog_convert_ctx_access(enum bpf_access_type type,
1857 				      const struct bpf_insn *si,
1858 				      struct bpf_insn *insn_buf,
1859 				      struct bpf_prog *prog, u32 *target_size)
1860 {
1861 	struct bpf_insn *insn = insn_buf;
1862 
1863 	switch (si->off) {
1864 	case offsetof(struct bpf_perf_event_data, sample_period):
1865 		*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
1866 						       data), si->dst_reg, si->src_reg,
1867 				      offsetof(struct bpf_perf_event_data_kern, data));
1868 		*insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg,
1869 				      bpf_target_off(struct perf_sample_data, period, 8,
1870 						     target_size));
1871 		break;
1872 	case offsetof(struct bpf_perf_event_data, addr):
1873 		*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
1874 						       data), si->dst_reg, si->src_reg,
1875 				      offsetof(struct bpf_perf_event_data_kern, data));
1876 		*insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg,
1877 				      bpf_target_off(struct perf_sample_data, addr, 8,
1878 						     target_size));
1879 		break;
1880 	default:
1881 		*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
1882 						       regs), si->dst_reg, si->src_reg,
1883 				      offsetof(struct bpf_perf_event_data_kern, regs));
1884 		*insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg,
1885 				      si->off);
1886 		break;
1887 	}
1888 
1889 	return insn - insn_buf;
1890 }
1891 
1892 const struct bpf_verifier_ops perf_event_verifier_ops = {
1893 	.get_func_proto		= pe_prog_func_proto,
1894 	.is_valid_access	= pe_prog_is_valid_access,
1895 	.convert_ctx_access	= pe_prog_convert_ctx_access,
1896 };
1897 
1898 const struct bpf_prog_ops perf_event_prog_ops = {
1899 };
1900 
1901 static DEFINE_MUTEX(bpf_event_mutex);
1902 
1903 #define BPF_TRACE_MAX_PROGS 64
1904 
1905 int perf_event_attach_bpf_prog(struct perf_event *event,
1906 			       struct bpf_prog *prog)
1907 {
1908 	struct bpf_prog_array *old_array;
1909 	struct bpf_prog_array *new_array;
1910 	int ret = -EEXIST;
1911 
1912 	/*
1913 	 * Kprobe override only works if they are on the function entry,
1914 	 * and only if they are on the opt-in list.
1915 	 */
1916 	if (prog->kprobe_override &&
1917 	    (!trace_kprobe_on_func_entry(event->tp_event) ||
1918 	     !trace_kprobe_error_injectable(event->tp_event)))
1919 		return -EINVAL;
1920 
1921 	mutex_lock(&bpf_event_mutex);
1922 
1923 	if (event->prog)
1924 		goto unlock;
1925 
1926 	old_array = bpf_event_rcu_dereference(event->tp_event->prog_array);
1927 	if (old_array &&
1928 	    bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) {
1929 		ret = -E2BIG;
1930 		goto unlock;
1931 	}
1932 
1933 	ret = bpf_prog_array_copy(old_array, NULL, prog, &new_array);
1934 	if (ret < 0)
1935 		goto unlock;
1936 
1937 	/* set the new array to event->tp_event and set event->prog */
1938 	event->prog = prog;
1939 	rcu_assign_pointer(event->tp_event->prog_array, new_array);
1940 	bpf_prog_array_free(old_array);
1941 
1942 unlock:
1943 	mutex_unlock(&bpf_event_mutex);
1944 	return ret;
1945 }
1946 
1947 void perf_event_detach_bpf_prog(struct perf_event *event)
1948 {
1949 	struct bpf_prog_array *old_array;
1950 	struct bpf_prog_array *new_array;
1951 	int ret;
1952 
1953 	mutex_lock(&bpf_event_mutex);
1954 
1955 	if (!event->prog)
1956 		goto unlock;
1957 
1958 	old_array = bpf_event_rcu_dereference(event->tp_event->prog_array);
1959 	ret = bpf_prog_array_copy(old_array, event->prog, NULL, &new_array);
1960 	if (ret == -ENOENT)
1961 		goto unlock;
1962 	if (ret < 0) {
1963 		bpf_prog_array_delete_safe(old_array, event->prog);
1964 	} else {
1965 		rcu_assign_pointer(event->tp_event->prog_array, new_array);
1966 		bpf_prog_array_free(old_array);
1967 	}
1968 
1969 	bpf_prog_put(event->prog);
1970 	event->prog = NULL;
1971 
1972 unlock:
1973 	mutex_unlock(&bpf_event_mutex);
1974 }
1975 
1976 int perf_event_query_prog_array(struct perf_event *event, void __user *info)
1977 {
1978 	struct perf_event_query_bpf __user *uquery = info;
1979 	struct perf_event_query_bpf query = {};
1980 	struct bpf_prog_array *progs;
1981 	u32 *ids, prog_cnt, ids_len;
1982 	int ret;
1983 
1984 	if (!perfmon_capable())
1985 		return -EPERM;
1986 	if (event->attr.type != PERF_TYPE_TRACEPOINT)
1987 		return -EINVAL;
1988 	if (copy_from_user(&query, uquery, sizeof(query)))
1989 		return -EFAULT;
1990 
1991 	ids_len = query.ids_len;
1992 	if (ids_len > BPF_TRACE_MAX_PROGS)
1993 		return -E2BIG;
1994 	ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN);
1995 	if (!ids)
1996 		return -ENOMEM;
1997 	/*
1998 	 * The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which
1999 	 * is required when user only wants to check for uquery->prog_cnt.
2000 	 * There is no need to check for it since the case is handled
2001 	 * gracefully in bpf_prog_array_copy_info.
2002 	 */
2003 
2004 	mutex_lock(&bpf_event_mutex);
2005 	progs = bpf_event_rcu_dereference(event->tp_event->prog_array);
2006 	ret = bpf_prog_array_copy_info(progs, ids, ids_len, &prog_cnt);
2007 	mutex_unlock(&bpf_event_mutex);
2008 
2009 	if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) ||
2010 	    copy_to_user(uquery->ids, ids, ids_len * sizeof(u32)))
2011 		ret = -EFAULT;
2012 
2013 	kfree(ids);
2014 	return ret;
2015 }
2016 
2017 extern struct bpf_raw_event_map __start__bpf_raw_tp[];
2018 extern struct bpf_raw_event_map __stop__bpf_raw_tp[];
2019 
2020 struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name)
2021 {
2022 	struct bpf_raw_event_map *btp = __start__bpf_raw_tp;
2023 
2024 	for (; btp < __stop__bpf_raw_tp; btp++) {
2025 		if (!strcmp(btp->tp->name, name))
2026 			return btp;
2027 	}
2028 
2029 	return bpf_get_raw_tracepoint_module(name);
2030 }
2031 
2032 void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp)
2033 {
2034 	struct module *mod = __module_address((unsigned long)btp);
2035 
2036 	if (mod)
2037 		module_put(mod);
2038 }
2039 
2040 static __always_inline
2041 void __bpf_trace_run(struct bpf_prog *prog, u64 *args)
2042 {
2043 	cant_sleep();
2044 	rcu_read_lock();
2045 	(void) BPF_PROG_RUN(prog, args);
2046 	rcu_read_unlock();
2047 }
2048 
2049 #define UNPACK(...)			__VA_ARGS__
2050 #define REPEAT_1(FN, DL, X, ...)	FN(X)
2051 #define REPEAT_2(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__)
2052 #define REPEAT_3(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_2(FN, DL, __VA_ARGS__)
2053 #define REPEAT_4(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_3(FN, DL, __VA_ARGS__)
2054 #define REPEAT_5(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_4(FN, DL, __VA_ARGS__)
2055 #define REPEAT_6(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_5(FN, DL, __VA_ARGS__)
2056 #define REPEAT_7(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_6(FN, DL, __VA_ARGS__)
2057 #define REPEAT_8(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_7(FN, DL, __VA_ARGS__)
2058 #define REPEAT_9(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_8(FN, DL, __VA_ARGS__)
2059 #define REPEAT_10(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_9(FN, DL, __VA_ARGS__)
2060 #define REPEAT_11(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_10(FN, DL, __VA_ARGS__)
2061 #define REPEAT_12(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_11(FN, DL, __VA_ARGS__)
2062 #define REPEAT(X, FN, DL, ...)		REPEAT_##X(FN, DL, __VA_ARGS__)
2063 
2064 #define SARG(X)		u64 arg##X
2065 #define COPY(X)		args[X] = arg##X
2066 
2067 #define __DL_COM	(,)
2068 #define __DL_SEM	(;)
2069 
2070 #define __SEQ_0_11	0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11
2071 
2072 #define BPF_TRACE_DEFN_x(x)						\
2073 	void bpf_trace_run##x(struct bpf_prog *prog,			\
2074 			      REPEAT(x, SARG, __DL_COM, __SEQ_0_11))	\
2075 	{								\
2076 		u64 args[x];						\
2077 		REPEAT(x, COPY, __DL_SEM, __SEQ_0_11);			\
2078 		__bpf_trace_run(prog, args);				\
2079 	}								\
2080 	EXPORT_SYMBOL_GPL(bpf_trace_run##x)
2081 BPF_TRACE_DEFN_x(1);
2082 BPF_TRACE_DEFN_x(2);
2083 BPF_TRACE_DEFN_x(3);
2084 BPF_TRACE_DEFN_x(4);
2085 BPF_TRACE_DEFN_x(5);
2086 BPF_TRACE_DEFN_x(6);
2087 BPF_TRACE_DEFN_x(7);
2088 BPF_TRACE_DEFN_x(8);
2089 BPF_TRACE_DEFN_x(9);
2090 BPF_TRACE_DEFN_x(10);
2091 BPF_TRACE_DEFN_x(11);
2092 BPF_TRACE_DEFN_x(12);
2093 
2094 static int __bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog)
2095 {
2096 	struct tracepoint *tp = btp->tp;
2097 
2098 	/*
2099 	 * check that program doesn't access arguments beyond what's
2100 	 * available in this tracepoint
2101 	 */
2102 	if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64))
2103 		return -EINVAL;
2104 
2105 	if (prog->aux->max_tp_access > btp->writable_size)
2106 		return -EINVAL;
2107 
2108 	return tracepoint_probe_register(tp, (void *)btp->bpf_func, prog);
2109 }
2110 
2111 int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog)
2112 {
2113 	return __bpf_probe_register(btp, prog);
2114 }
2115 
2116 int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_prog *prog)
2117 {
2118 	return tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, prog);
2119 }
2120 
2121 int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id,
2122 			    u32 *fd_type, const char **buf,
2123 			    u64 *probe_offset, u64 *probe_addr)
2124 {
2125 	bool is_tracepoint, is_syscall_tp;
2126 	struct bpf_prog *prog;
2127 	int flags, err = 0;
2128 
2129 	prog = event->prog;
2130 	if (!prog)
2131 		return -ENOENT;
2132 
2133 	/* not supporting BPF_PROG_TYPE_PERF_EVENT yet */
2134 	if (prog->type == BPF_PROG_TYPE_PERF_EVENT)
2135 		return -EOPNOTSUPP;
2136 
2137 	*prog_id = prog->aux->id;
2138 	flags = event->tp_event->flags;
2139 	is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT;
2140 	is_syscall_tp = is_syscall_trace_event(event->tp_event);
2141 
2142 	if (is_tracepoint || is_syscall_tp) {
2143 		*buf = is_tracepoint ? event->tp_event->tp->name
2144 				     : event->tp_event->name;
2145 		*fd_type = BPF_FD_TYPE_TRACEPOINT;
2146 		*probe_offset = 0x0;
2147 		*probe_addr = 0x0;
2148 	} else {
2149 		/* kprobe/uprobe */
2150 		err = -EOPNOTSUPP;
2151 #ifdef CONFIG_KPROBE_EVENTS
2152 		if (flags & TRACE_EVENT_FL_KPROBE)
2153 			err = bpf_get_kprobe_info(event, fd_type, buf,
2154 						  probe_offset, probe_addr,
2155 						  event->attr.type == PERF_TYPE_TRACEPOINT);
2156 #endif
2157 #ifdef CONFIG_UPROBE_EVENTS
2158 		if (flags & TRACE_EVENT_FL_UPROBE)
2159 			err = bpf_get_uprobe_info(event, fd_type, buf,
2160 						  probe_offset,
2161 						  event->attr.type == PERF_TYPE_TRACEPOINT);
2162 #endif
2163 	}
2164 
2165 	return err;
2166 }
2167 
2168 static int __init send_signal_irq_work_init(void)
2169 {
2170 	int cpu;
2171 	struct send_signal_irq_work *work;
2172 
2173 	for_each_possible_cpu(cpu) {
2174 		work = per_cpu_ptr(&send_signal_work, cpu);
2175 		init_irq_work(&work->irq_work, do_bpf_send_signal);
2176 	}
2177 	return 0;
2178 }
2179 
2180 subsys_initcall(send_signal_irq_work_init);
2181 
2182 #ifdef CONFIG_MODULES
2183 static int bpf_event_notify(struct notifier_block *nb, unsigned long op,
2184 			    void *module)
2185 {
2186 	struct bpf_trace_module *btm, *tmp;
2187 	struct module *mod = module;
2188 	int ret = 0;
2189 
2190 	if (mod->num_bpf_raw_events == 0 ||
2191 	    (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING))
2192 		goto out;
2193 
2194 	mutex_lock(&bpf_module_mutex);
2195 
2196 	switch (op) {
2197 	case MODULE_STATE_COMING:
2198 		btm = kzalloc(sizeof(*btm), GFP_KERNEL);
2199 		if (btm) {
2200 			btm->module = module;
2201 			list_add(&btm->list, &bpf_trace_modules);
2202 		} else {
2203 			ret = -ENOMEM;
2204 		}
2205 		break;
2206 	case MODULE_STATE_GOING:
2207 		list_for_each_entry_safe(btm, tmp, &bpf_trace_modules, list) {
2208 			if (btm->module == module) {
2209 				list_del(&btm->list);
2210 				kfree(btm);
2211 				break;
2212 			}
2213 		}
2214 		break;
2215 	}
2216 
2217 	mutex_unlock(&bpf_module_mutex);
2218 
2219 out:
2220 	return notifier_from_errno(ret);
2221 }
2222 
2223 static struct notifier_block bpf_module_nb = {
2224 	.notifier_call = bpf_event_notify,
2225 };
2226 
2227 static int __init bpf_event_init(void)
2228 {
2229 	register_module_notifier(&bpf_module_nb);
2230 	return 0;
2231 }
2232 
2233 fs_initcall(bpf_event_init);
2234 #endif /* CONFIG_MODULES */
2235