xref: /openbmc/linux/kernel/trace/bpf_trace.c (revision 2425c81f)
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 #include <linux/fprobe.h>
21 #include <linux/bsearch.h>
22 #include <linux/sort.h>
23 
24 #include <net/bpf_sk_storage.h>
25 
26 #include <uapi/linux/bpf.h>
27 #include <uapi/linux/btf.h>
28 
29 #include <asm/tlb.h>
30 
31 #include "trace_probe.h"
32 #include "trace.h"
33 
34 #define CREATE_TRACE_POINTS
35 #include "bpf_trace.h"
36 
37 #define bpf_event_rcu_dereference(p)					\
38 	rcu_dereference_protected(p, lockdep_is_held(&bpf_event_mutex))
39 
40 #ifdef CONFIG_MODULES
41 struct bpf_trace_module {
42 	struct module *module;
43 	struct list_head list;
44 };
45 
46 static LIST_HEAD(bpf_trace_modules);
47 static DEFINE_MUTEX(bpf_module_mutex);
48 
49 static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name)
50 {
51 	struct bpf_raw_event_map *btp, *ret = NULL;
52 	struct bpf_trace_module *btm;
53 	unsigned int i;
54 
55 	mutex_lock(&bpf_module_mutex);
56 	list_for_each_entry(btm, &bpf_trace_modules, list) {
57 		for (i = 0; i < btm->module->num_bpf_raw_events; ++i) {
58 			btp = &btm->module->bpf_raw_events[i];
59 			if (!strcmp(btp->tp->name, name)) {
60 				if (try_module_get(btm->module))
61 					ret = btp;
62 				goto out;
63 			}
64 		}
65 	}
66 out:
67 	mutex_unlock(&bpf_module_mutex);
68 	return ret;
69 }
70 #else
71 static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name)
72 {
73 	return NULL;
74 }
75 #endif /* CONFIG_MODULES */
76 
77 u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
78 u64 bpf_get_stack(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
79 
80 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size,
81 				  u64 flags, const struct btf **btf,
82 				  s32 *btf_id);
83 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx);
84 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx);
85 
86 /**
87  * trace_call_bpf - invoke BPF program
88  * @call: tracepoint event
89  * @ctx: opaque context pointer
90  *
91  * kprobe handlers execute BPF programs via this helper.
92  * Can be used from static tracepoints in the future.
93  *
94  * Return: BPF programs always return an integer which is interpreted by
95  * kprobe handler as:
96  * 0 - return from kprobe (event is filtered out)
97  * 1 - store kprobe event into ring buffer
98  * Other values are reserved and currently alias to 1
99  */
100 unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx)
101 {
102 	unsigned int ret;
103 
104 	cant_sleep();
105 
106 	if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) {
107 		/*
108 		 * since some bpf program is already running on this cpu,
109 		 * don't call into another bpf program (same or different)
110 		 * and don't send kprobe event into ring-buffer,
111 		 * so return zero here
112 		 */
113 		ret = 0;
114 		goto out;
115 	}
116 
117 	/*
118 	 * Instead of moving rcu_read_lock/rcu_dereference/rcu_read_unlock
119 	 * to all call sites, we did a bpf_prog_array_valid() there to check
120 	 * whether call->prog_array is empty or not, which is
121 	 * a heuristic to speed up execution.
122 	 *
123 	 * If bpf_prog_array_valid() fetched prog_array was
124 	 * non-NULL, we go into trace_call_bpf() and do the actual
125 	 * proper rcu_dereference() under RCU lock.
126 	 * If it turns out that prog_array is NULL then, we bail out.
127 	 * For the opposite, if the bpf_prog_array_valid() fetched pointer
128 	 * was NULL, you'll skip the prog_array with the risk of missing
129 	 * out of events when it was updated in between this and the
130 	 * rcu_dereference() which is accepted risk.
131 	 */
132 	ret = BPF_PROG_RUN_ARRAY(call->prog_array, ctx, bpf_prog_run);
133 
134  out:
135 	__this_cpu_dec(bpf_prog_active);
136 
137 	return ret;
138 }
139 
140 #ifdef CONFIG_BPF_KPROBE_OVERRIDE
141 BPF_CALL_2(bpf_override_return, struct pt_regs *, regs, unsigned long, rc)
142 {
143 	regs_set_return_value(regs, rc);
144 	override_function_with_return(regs);
145 	return 0;
146 }
147 
148 static const struct bpf_func_proto bpf_override_return_proto = {
149 	.func		= bpf_override_return,
150 	.gpl_only	= true,
151 	.ret_type	= RET_INTEGER,
152 	.arg1_type	= ARG_PTR_TO_CTX,
153 	.arg2_type	= ARG_ANYTHING,
154 };
155 #endif
156 
157 static __always_inline int
158 bpf_probe_read_user_common(void *dst, u32 size, const void __user *unsafe_ptr)
159 {
160 	int ret;
161 
162 	ret = copy_from_user_nofault(dst, unsafe_ptr, size);
163 	if (unlikely(ret < 0))
164 		memset(dst, 0, size);
165 	return ret;
166 }
167 
168 BPF_CALL_3(bpf_probe_read_user, void *, dst, u32, size,
169 	   const void __user *, unsafe_ptr)
170 {
171 	return bpf_probe_read_user_common(dst, size, unsafe_ptr);
172 }
173 
174 const struct bpf_func_proto bpf_probe_read_user_proto = {
175 	.func		= bpf_probe_read_user,
176 	.gpl_only	= true,
177 	.ret_type	= RET_INTEGER,
178 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
179 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
180 	.arg3_type	= ARG_ANYTHING,
181 };
182 
183 static __always_inline int
184 bpf_probe_read_user_str_common(void *dst, u32 size,
185 			       const void __user *unsafe_ptr)
186 {
187 	int ret;
188 
189 	/*
190 	 * NB: We rely on strncpy_from_user() not copying junk past the NUL
191 	 * terminator into `dst`.
192 	 *
193 	 * strncpy_from_user() does long-sized strides in the fast path. If the
194 	 * strncpy does not mask out the bytes after the NUL in `unsafe_ptr`,
195 	 * then there could be junk after the NUL in `dst`. If user takes `dst`
196 	 * and keys a hash map with it, then semantically identical strings can
197 	 * occupy multiple entries in the map.
198 	 */
199 	ret = strncpy_from_user_nofault(dst, unsafe_ptr, size);
200 	if (unlikely(ret < 0))
201 		memset(dst, 0, size);
202 	return ret;
203 }
204 
205 BPF_CALL_3(bpf_probe_read_user_str, void *, dst, u32, size,
206 	   const void __user *, unsafe_ptr)
207 {
208 	return bpf_probe_read_user_str_common(dst, size, unsafe_ptr);
209 }
210 
211 const struct bpf_func_proto bpf_probe_read_user_str_proto = {
212 	.func		= bpf_probe_read_user_str,
213 	.gpl_only	= true,
214 	.ret_type	= RET_INTEGER,
215 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
216 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
217 	.arg3_type	= ARG_ANYTHING,
218 };
219 
220 static __always_inline int
221 bpf_probe_read_kernel_common(void *dst, u32 size, const void *unsafe_ptr)
222 {
223 	int ret;
224 
225 	ret = copy_from_kernel_nofault(dst, unsafe_ptr, size);
226 	if (unlikely(ret < 0))
227 		memset(dst, 0, size);
228 	return ret;
229 }
230 
231 BPF_CALL_3(bpf_probe_read_kernel, void *, dst, u32, size,
232 	   const void *, unsafe_ptr)
233 {
234 	return bpf_probe_read_kernel_common(dst, size, unsafe_ptr);
235 }
236 
237 const struct bpf_func_proto bpf_probe_read_kernel_proto = {
238 	.func		= bpf_probe_read_kernel,
239 	.gpl_only	= true,
240 	.ret_type	= RET_INTEGER,
241 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
242 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
243 	.arg3_type	= ARG_ANYTHING,
244 };
245 
246 static __always_inline int
247 bpf_probe_read_kernel_str_common(void *dst, u32 size, const void *unsafe_ptr)
248 {
249 	int ret;
250 
251 	/*
252 	 * The strncpy_from_kernel_nofault() call will likely not fill the
253 	 * entire buffer, but that's okay in this circumstance as we're probing
254 	 * arbitrary memory anyway similar to bpf_probe_read_*() and might
255 	 * as well probe the stack. Thus, memory is explicitly cleared
256 	 * only in error case, so that improper users ignoring return
257 	 * code altogether don't copy garbage; otherwise length of string
258 	 * is returned that can be used for bpf_perf_event_output() et al.
259 	 */
260 	ret = strncpy_from_kernel_nofault(dst, unsafe_ptr, size);
261 	if (unlikely(ret < 0))
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(!nmi_uaccess_okay()))
341 		return -EPERM;
342 
343 	return copy_to_user_nofault(unsafe_ptr, src, size);
344 }
345 
346 static const struct bpf_func_proto bpf_probe_write_user_proto = {
347 	.func		= bpf_probe_write_user,
348 	.gpl_only	= true,
349 	.ret_type	= RET_INTEGER,
350 	.arg1_type	= ARG_ANYTHING,
351 	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
352 	.arg3_type	= ARG_CONST_SIZE,
353 };
354 
355 static const struct bpf_func_proto *bpf_get_probe_write_proto(void)
356 {
357 	if (!capable(CAP_SYS_ADMIN))
358 		return NULL;
359 
360 	pr_warn_ratelimited("%s[%d] is installing a program with bpf_probe_write_user helper that may corrupt user memory!",
361 			    current->comm, task_pid_nr(current));
362 
363 	return &bpf_probe_write_user_proto;
364 }
365 
366 static DEFINE_RAW_SPINLOCK(trace_printk_lock);
367 
368 #define MAX_TRACE_PRINTK_VARARGS	3
369 #define BPF_TRACE_PRINTK_SIZE		1024
370 
371 BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1,
372 	   u64, arg2, u64, arg3)
373 {
374 	u64 args[MAX_TRACE_PRINTK_VARARGS] = { arg1, arg2, arg3 };
375 	u32 *bin_args;
376 	static char buf[BPF_TRACE_PRINTK_SIZE];
377 	unsigned long flags;
378 	int ret;
379 
380 	ret = bpf_bprintf_prepare(fmt, fmt_size, args, &bin_args,
381 				  MAX_TRACE_PRINTK_VARARGS);
382 	if (ret < 0)
383 		return ret;
384 
385 	raw_spin_lock_irqsave(&trace_printk_lock, flags);
386 	ret = bstr_printf(buf, sizeof(buf), fmt, bin_args);
387 
388 	trace_bpf_trace_printk(buf);
389 	raw_spin_unlock_irqrestore(&trace_printk_lock, flags);
390 
391 	bpf_bprintf_cleanup();
392 
393 	return ret;
394 }
395 
396 static const struct bpf_func_proto bpf_trace_printk_proto = {
397 	.func		= bpf_trace_printk,
398 	.gpl_only	= true,
399 	.ret_type	= RET_INTEGER,
400 	.arg1_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
401 	.arg2_type	= ARG_CONST_SIZE,
402 };
403 
404 static void __set_printk_clr_event(void)
405 {
406 	/*
407 	 * This program might be calling bpf_trace_printk,
408 	 * so enable the associated bpf_trace/bpf_trace_printk event.
409 	 * Repeat this each time as it is possible a user has
410 	 * disabled bpf_trace_printk events.  By loading a program
411 	 * calling bpf_trace_printk() however the user has expressed
412 	 * the intent to see such events.
413 	 */
414 	if (trace_set_clr_event("bpf_trace", "bpf_trace_printk", 1))
415 		pr_warn_ratelimited("could not enable bpf_trace_printk events");
416 }
417 
418 const struct bpf_func_proto *bpf_get_trace_printk_proto(void)
419 {
420 	__set_printk_clr_event();
421 	return &bpf_trace_printk_proto;
422 }
423 
424 BPF_CALL_4(bpf_trace_vprintk, char *, fmt, u32, fmt_size, const void *, data,
425 	   u32, data_len)
426 {
427 	static char buf[BPF_TRACE_PRINTK_SIZE];
428 	unsigned long flags;
429 	int ret, num_args;
430 	u32 *bin_args;
431 
432 	if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 ||
433 	    (data_len && !data))
434 		return -EINVAL;
435 	num_args = data_len / 8;
436 
437 	ret = bpf_bprintf_prepare(fmt, fmt_size, data, &bin_args, num_args);
438 	if (ret < 0)
439 		return ret;
440 
441 	raw_spin_lock_irqsave(&trace_printk_lock, flags);
442 	ret = bstr_printf(buf, sizeof(buf), fmt, bin_args);
443 
444 	trace_bpf_trace_printk(buf);
445 	raw_spin_unlock_irqrestore(&trace_printk_lock, flags);
446 
447 	bpf_bprintf_cleanup();
448 
449 	return ret;
450 }
451 
452 static const struct bpf_func_proto bpf_trace_vprintk_proto = {
453 	.func		= bpf_trace_vprintk,
454 	.gpl_only	= true,
455 	.ret_type	= RET_INTEGER,
456 	.arg1_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
457 	.arg2_type	= ARG_CONST_SIZE,
458 	.arg3_type	= ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY,
459 	.arg4_type	= ARG_CONST_SIZE_OR_ZERO,
460 };
461 
462 const struct bpf_func_proto *bpf_get_trace_vprintk_proto(void)
463 {
464 	__set_printk_clr_event();
465 	return &bpf_trace_vprintk_proto;
466 }
467 
468 BPF_CALL_5(bpf_seq_printf, struct seq_file *, m, char *, fmt, u32, fmt_size,
469 	   const void *, data, u32, data_len)
470 {
471 	int err, num_args;
472 	u32 *bin_args;
473 
474 	if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 ||
475 	    (data_len && !data))
476 		return -EINVAL;
477 	num_args = data_len / 8;
478 
479 	err = bpf_bprintf_prepare(fmt, fmt_size, data, &bin_args, num_args);
480 	if (err < 0)
481 		return err;
482 
483 	seq_bprintf(m, fmt, bin_args);
484 
485 	bpf_bprintf_cleanup();
486 
487 	return seq_has_overflowed(m) ? -EOVERFLOW : 0;
488 }
489 
490 BTF_ID_LIST_SINGLE(btf_seq_file_ids, struct, seq_file)
491 
492 static const struct bpf_func_proto bpf_seq_printf_proto = {
493 	.func		= bpf_seq_printf,
494 	.gpl_only	= true,
495 	.ret_type	= RET_INTEGER,
496 	.arg1_type	= ARG_PTR_TO_BTF_ID,
497 	.arg1_btf_id	= &btf_seq_file_ids[0],
498 	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
499 	.arg3_type	= ARG_CONST_SIZE,
500 	.arg4_type      = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY,
501 	.arg5_type      = ARG_CONST_SIZE_OR_ZERO,
502 };
503 
504 BPF_CALL_3(bpf_seq_write, struct seq_file *, m, const void *, data, u32, len)
505 {
506 	return seq_write(m, data, len) ? -EOVERFLOW : 0;
507 }
508 
509 static const struct bpf_func_proto bpf_seq_write_proto = {
510 	.func		= bpf_seq_write,
511 	.gpl_only	= true,
512 	.ret_type	= RET_INTEGER,
513 	.arg1_type	= ARG_PTR_TO_BTF_ID,
514 	.arg1_btf_id	= &btf_seq_file_ids[0],
515 	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
516 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
517 };
518 
519 BPF_CALL_4(bpf_seq_printf_btf, struct seq_file *, m, struct btf_ptr *, ptr,
520 	   u32, btf_ptr_size, u64, flags)
521 {
522 	const struct btf *btf;
523 	s32 btf_id;
524 	int ret;
525 
526 	ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id);
527 	if (ret)
528 		return ret;
529 
530 	return btf_type_seq_show_flags(btf, btf_id, ptr->ptr, m, flags);
531 }
532 
533 static const struct bpf_func_proto bpf_seq_printf_btf_proto = {
534 	.func		= bpf_seq_printf_btf,
535 	.gpl_only	= true,
536 	.ret_type	= RET_INTEGER,
537 	.arg1_type	= ARG_PTR_TO_BTF_ID,
538 	.arg1_btf_id	= &btf_seq_file_ids[0],
539 	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
540 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
541 	.arg4_type	= ARG_ANYTHING,
542 };
543 
544 static __always_inline int
545 get_map_perf_counter(struct bpf_map *map, u64 flags,
546 		     u64 *value, u64 *enabled, u64 *running)
547 {
548 	struct bpf_array *array = container_of(map, struct bpf_array, map);
549 	unsigned int cpu = smp_processor_id();
550 	u64 index = flags & BPF_F_INDEX_MASK;
551 	struct bpf_event_entry *ee;
552 
553 	if (unlikely(flags & ~(BPF_F_INDEX_MASK)))
554 		return -EINVAL;
555 	if (index == BPF_F_CURRENT_CPU)
556 		index = cpu;
557 	if (unlikely(index >= array->map.max_entries))
558 		return -E2BIG;
559 
560 	ee = READ_ONCE(array->ptrs[index]);
561 	if (!ee)
562 		return -ENOENT;
563 
564 	return perf_event_read_local(ee->event, value, enabled, running);
565 }
566 
567 BPF_CALL_2(bpf_perf_event_read, struct bpf_map *, map, u64, flags)
568 {
569 	u64 value = 0;
570 	int err;
571 
572 	err = get_map_perf_counter(map, flags, &value, NULL, NULL);
573 	/*
574 	 * this api is ugly since we miss [-22..-2] range of valid
575 	 * counter values, but that's uapi
576 	 */
577 	if (err)
578 		return err;
579 	return value;
580 }
581 
582 static const struct bpf_func_proto bpf_perf_event_read_proto = {
583 	.func		= bpf_perf_event_read,
584 	.gpl_only	= true,
585 	.ret_type	= RET_INTEGER,
586 	.arg1_type	= ARG_CONST_MAP_PTR,
587 	.arg2_type	= ARG_ANYTHING,
588 };
589 
590 BPF_CALL_4(bpf_perf_event_read_value, struct bpf_map *, map, u64, flags,
591 	   struct bpf_perf_event_value *, buf, u32, size)
592 {
593 	int err = -EINVAL;
594 
595 	if (unlikely(size != sizeof(struct bpf_perf_event_value)))
596 		goto clear;
597 	err = get_map_perf_counter(map, flags, &buf->counter, &buf->enabled,
598 				   &buf->running);
599 	if (unlikely(err))
600 		goto clear;
601 	return 0;
602 clear:
603 	memset(buf, 0, size);
604 	return err;
605 }
606 
607 static const struct bpf_func_proto bpf_perf_event_read_value_proto = {
608 	.func		= bpf_perf_event_read_value,
609 	.gpl_only	= true,
610 	.ret_type	= RET_INTEGER,
611 	.arg1_type	= ARG_CONST_MAP_PTR,
612 	.arg2_type	= ARG_ANYTHING,
613 	.arg3_type	= ARG_PTR_TO_UNINIT_MEM,
614 	.arg4_type	= ARG_CONST_SIZE,
615 };
616 
617 static __always_inline u64
618 __bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map,
619 			u64 flags, struct perf_sample_data *sd)
620 {
621 	struct bpf_array *array = container_of(map, struct bpf_array, map);
622 	unsigned int cpu = smp_processor_id();
623 	u64 index = flags & BPF_F_INDEX_MASK;
624 	struct bpf_event_entry *ee;
625 	struct perf_event *event;
626 
627 	if (index == BPF_F_CURRENT_CPU)
628 		index = cpu;
629 	if (unlikely(index >= array->map.max_entries))
630 		return -E2BIG;
631 
632 	ee = READ_ONCE(array->ptrs[index]);
633 	if (!ee)
634 		return -ENOENT;
635 
636 	event = ee->event;
637 	if (unlikely(event->attr.type != PERF_TYPE_SOFTWARE ||
638 		     event->attr.config != PERF_COUNT_SW_BPF_OUTPUT))
639 		return -EINVAL;
640 
641 	if (unlikely(event->oncpu != cpu))
642 		return -EOPNOTSUPP;
643 
644 	return perf_event_output(event, sd, regs);
645 }
646 
647 /*
648  * Support executing tracepoints in normal, irq, and nmi context that each call
649  * bpf_perf_event_output
650  */
651 struct bpf_trace_sample_data {
652 	struct perf_sample_data sds[3];
653 };
654 
655 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_trace_sds);
656 static DEFINE_PER_CPU(int, bpf_trace_nest_level);
657 BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map,
658 	   u64, flags, void *, data, u64, size)
659 {
660 	struct bpf_trace_sample_data *sds = this_cpu_ptr(&bpf_trace_sds);
661 	int nest_level = this_cpu_inc_return(bpf_trace_nest_level);
662 	struct perf_raw_record raw = {
663 		.frag = {
664 			.size = size,
665 			.data = data,
666 		},
667 	};
668 	struct perf_sample_data *sd;
669 	int err;
670 
671 	if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(sds->sds))) {
672 		err = -EBUSY;
673 		goto out;
674 	}
675 
676 	sd = &sds->sds[nest_level - 1];
677 
678 	if (unlikely(flags & ~(BPF_F_INDEX_MASK))) {
679 		err = -EINVAL;
680 		goto out;
681 	}
682 
683 	perf_sample_data_init(sd, 0, 0);
684 	sd->raw = &raw;
685 
686 	err = __bpf_perf_event_output(regs, map, flags, sd);
687 
688 out:
689 	this_cpu_dec(bpf_trace_nest_level);
690 	return err;
691 }
692 
693 static const struct bpf_func_proto bpf_perf_event_output_proto = {
694 	.func		= bpf_perf_event_output,
695 	.gpl_only	= true,
696 	.ret_type	= RET_INTEGER,
697 	.arg1_type	= ARG_PTR_TO_CTX,
698 	.arg2_type	= ARG_CONST_MAP_PTR,
699 	.arg3_type	= ARG_ANYTHING,
700 	.arg4_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
701 	.arg5_type	= ARG_CONST_SIZE_OR_ZERO,
702 };
703 
704 static DEFINE_PER_CPU(int, bpf_event_output_nest_level);
705 struct bpf_nested_pt_regs {
706 	struct pt_regs regs[3];
707 };
708 static DEFINE_PER_CPU(struct bpf_nested_pt_regs, bpf_pt_regs);
709 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_misc_sds);
710 
711 u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
712 		     void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy)
713 {
714 	int nest_level = this_cpu_inc_return(bpf_event_output_nest_level);
715 	struct perf_raw_frag frag = {
716 		.copy		= ctx_copy,
717 		.size		= ctx_size,
718 		.data		= ctx,
719 	};
720 	struct perf_raw_record raw = {
721 		.frag = {
722 			{
723 				.next	= ctx_size ? &frag : NULL,
724 			},
725 			.size	= meta_size,
726 			.data	= meta,
727 		},
728 	};
729 	struct perf_sample_data *sd;
730 	struct pt_regs *regs;
731 	u64 ret;
732 
733 	if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(bpf_misc_sds.sds))) {
734 		ret = -EBUSY;
735 		goto out;
736 	}
737 	sd = this_cpu_ptr(&bpf_misc_sds.sds[nest_level - 1]);
738 	regs = this_cpu_ptr(&bpf_pt_regs.regs[nest_level - 1]);
739 
740 	perf_fetch_caller_regs(regs);
741 	perf_sample_data_init(sd, 0, 0);
742 	sd->raw = &raw;
743 
744 	ret = __bpf_perf_event_output(regs, map, flags, sd);
745 out:
746 	this_cpu_dec(bpf_event_output_nest_level);
747 	return ret;
748 }
749 
750 BPF_CALL_0(bpf_get_current_task)
751 {
752 	return (long) current;
753 }
754 
755 const struct bpf_func_proto bpf_get_current_task_proto = {
756 	.func		= bpf_get_current_task,
757 	.gpl_only	= true,
758 	.ret_type	= RET_INTEGER,
759 };
760 
761 BPF_CALL_0(bpf_get_current_task_btf)
762 {
763 	return (unsigned long) current;
764 }
765 
766 const struct bpf_func_proto bpf_get_current_task_btf_proto = {
767 	.func		= bpf_get_current_task_btf,
768 	.gpl_only	= true,
769 	.ret_type	= RET_PTR_TO_BTF_ID,
770 	.ret_btf_id	= &btf_tracing_ids[BTF_TRACING_TYPE_TASK],
771 };
772 
773 BPF_CALL_1(bpf_task_pt_regs, struct task_struct *, task)
774 {
775 	return (unsigned long) task_pt_regs(task);
776 }
777 
778 BTF_ID_LIST(bpf_task_pt_regs_ids)
779 BTF_ID(struct, pt_regs)
780 
781 const struct bpf_func_proto bpf_task_pt_regs_proto = {
782 	.func		= bpf_task_pt_regs,
783 	.gpl_only	= true,
784 	.arg1_type	= ARG_PTR_TO_BTF_ID,
785 	.arg1_btf_id	= &btf_tracing_ids[BTF_TRACING_TYPE_TASK],
786 	.ret_type	= RET_PTR_TO_BTF_ID,
787 	.ret_btf_id	= &bpf_task_pt_regs_ids[0],
788 };
789 
790 BPF_CALL_2(bpf_current_task_under_cgroup, struct bpf_map *, map, u32, idx)
791 {
792 	struct bpf_array *array = container_of(map, struct bpf_array, map);
793 	struct cgroup *cgrp;
794 
795 	if (unlikely(idx >= array->map.max_entries))
796 		return -E2BIG;
797 
798 	cgrp = READ_ONCE(array->ptrs[idx]);
799 	if (unlikely(!cgrp))
800 		return -EAGAIN;
801 
802 	return task_under_cgroup_hierarchy(current, cgrp);
803 }
804 
805 static const struct bpf_func_proto bpf_current_task_under_cgroup_proto = {
806 	.func           = bpf_current_task_under_cgroup,
807 	.gpl_only       = false,
808 	.ret_type       = RET_INTEGER,
809 	.arg1_type      = ARG_CONST_MAP_PTR,
810 	.arg2_type      = ARG_ANYTHING,
811 };
812 
813 struct send_signal_irq_work {
814 	struct irq_work irq_work;
815 	struct task_struct *task;
816 	u32 sig;
817 	enum pid_type type;
818 };
819 
820 static DEFINE_PER_CPU(struct send_signal_irq_work, send_signal_work);
821 
822 static void do_bpf_send_signal(struct irq_work *entry)
823 {
824 	struct send_signal_irq_work *work;
825 
826 	work = container_of(entry, struct send_signal_irq_work, irq_work);
827 	group_send_sig_info(work->sig, SEND_SIG_PRIV, work->task, work->type);
828 }
829 
830 static int bpf_send_signal_common(u32 sig, enum pid_type type)
831 {
832 	struct send_signal_irq_work *work = NULL;
833 
834 	/* Similar to bpf_probe_write_user, task needs to be
835 	 * in a sound condition and kernel memory access be
836 	 * permitted in order to send signal to the current
837 	 * task.
838 	 */
839 	if (unlikely(current->flags & (PF_KTHREAD | PF_EXITING)))
840 		return -EPERM;
841 	if (unlikely(!nmi_uaccess_okay()))
842 		return -EPERM;
843 
844 	if (irqs_disabled()) {
845 		/* Do an early check on signal validity. Otherwise,
846 		 * the error is lost in deferred irq_work.
847 		 */
848 		if (unlikely(!valid_signal(sig)))
849 			return -EINVAL;
850 
851 		work = this_cpu_ptr(&send_signal_work);
852 		if (irq_work_is_busy(&work->irq_work))
853 			return -EBUSY;
854 
855 		/* Add the current task, which is the target of sending signal,
856 		 * to the irq_work. The current task may change when queued
857 		 * irq works get executed.
858 		 */
859 		work->task = current;
860 		work->sig = sig;
861 		work->type = type;
862 		irq_work_queue(&work->irq_work);
863 		return 0;
864 	}
865 
866 	return group_send_sig_info(sig, SEND_SIG_PRIV, current, type);
867 }
868 
869 BPF_CALL_1(bpf_send_signal, u32, sig)
870 {
871 	return bpf_send_signal_common(sig, PIDTYPE_TGID);
872 }
873 
874 static const struct bpf_func_proto bpf_send_signal_proto = {
875 	.func		= bpf_send_signal,
876 	.gpl_only	= false,
877 	.ret_type	= RET_INTEGER,
878 	.arg1_type	= ARG_ANYTHING,
879 };
880 
881 BPF_CALL_1(bpf_send_signal_thread, u32, sig)
882 {
883 	return bpf_send_signal_common(sig, PIDTYPE_PID);
884 }
885 
886 static const struct bpf_func_proto bpf_send_signal_thread_proto = {
887 	.func		= bpf_send_signal_thread,
888 	.gpl_only	= false,
889 	.ret_type	= RET_INTEGER,
890 	.arg1_type	= ARG_ANYTHING,
891 };
892 
893 BPF_CALL_3(bpf_d_path, struct path *, path, char *, buf, u32, sz)
894 {
895 	long len;
896 	char *p;
897 
898 	if (!sz)
899 		return 0;
900 
901 	p = d_path(path, buf, sz);
902 	if (IS_ERR(p)) {
903 		len = PTR_ERR(p);
904 	} else {
905 		len = buf + sz - p;
906 		memmove(buf, p, len);
907 	}
908 
909 	return len;
910 }
911 
912 BTF_SET_START(btf_allowlist_d_path)
913 #ifdef CONFIG_SECURITY
914 BTF_ID(func, security_file_permission)
915 BTF_ID(func, security_inode_getattr)
916 BTF_ID(func, security_file_open)
917 #endif
918 #ifdef CONFIG_SECURITY_PATH
919 BTF_ID(func, security_path_truncate)
920 #endif
921 BTF_ID(func, vfs_truncate)
922 BTF_ID(func, vfs_fallocate)
923 BTF_ID(func, dentry_open)
924 BTF_ID(func, vfs_getattr)
925 BTF_ID(func, filp_close)
926 BTF_SET_END(btf_allowlist_d_path)
927 
928 static bool bpf_d_path_allowed(const struct bpf_prog *prog)
929 {
930 	if (prog->type == BPF_PROG_TYPE_TRACING &&
931 	    prog->expected_attach_type == BPF_TRACE_ITER)
932 		return true;
933 
934 	if (prog->type == BPF_PROG_TYPE_LSM)
935 		return bpf_lsm_is_sleepable_hook(prog->aux->attach_btf_id);
936 
937 	return btf_id_set_contains(&btf_allowlist_d_path,
938 				   prog->aux->attach_btf_id);
939 }
940 
941 BTF_ID_LIST_SINGLE(bpf_d_path_btf_ids, struct, path)
942 
943 static const struct bpf_func_proto bpf_d_path_proto = {
944 	.func		= bpf_d_path,
945 	.gpl_only	= false,
946 	.ret_type	= RET_INTEGER,
947 	.arg1_type	= ARG_PTR_TO_BTF_ID,
948 	.arg1_btf_id	= &bpf_d_path_btf_ids[0],
949 	.arg2_type	= ARG_PTR_TO_MEM,
950 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
951 	.allowed	= bpf_d_path_allowed,
952 };
953 
954 #define BTF_F_ALL	(BTF_F_COMPACT  | BTF_F_NONAME | \
955 			 BTF_F_PTR_RAW | BTF_F_ZERO)
956 
957 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size,
958 				  u64 flags, const struct btf **btf,
959 				  s32 *btf_id)
960 {
961 	const struct btf_type *t;
962 
963 	if (unlikely(flags & ~(BTF_F_ALL)))
964 		return -EINVAL;
965 
966 	if (btf_ptr_size != sizeof(struct btf_ptr))
967 		return -EINVAL;
968 
969 	*btf = bpf_get_btf_vmlinux();
970 
971 	if (IS_ERR_OR_NULL(*btf))
972 		return IS_ERR(*btf) ? PTR_ERR(*btf) : -EINVAL;
973 
974 	if (ptr->type_id > 0)
975 		*btf_id = ptr->type_id;
976 	else
977 		return -EINVAL;
978 
979 	if (*btf_id > 0)
980 		t = btf_type_by_id(*btf, *btf_id);
981 	if (*btf_id <= 0 || !t)
982 		return -ENOENT;
983 
984 	return 0;
985 }
986 
987 BPF_CALL_5(bpf_snprintf_btf, char *, str, u32, str_size, struct btf_ptr *, ptr,
988 	   u32, btf_ptr_size, u64, flags)
989 {
990 	const struct btf *btf;
991 	s32 btf_id;
992 	int ret;
993 
994 	ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id);
995 	if (ret)
996 		return ret;
997 
998 	return btf_type_snprintf_show(btf, btf_id, ptr->ptr, str, str_size,
999 				      flags);
1000 }
1001 
1002 const struct bpf_func_proto bpf_snprintf_btf_proto = {
1003 	.func		= bpf_snprintf_btf,
1004 	.gpl_only	= false,
1005 	.ret_type	= RET_INTEGER,
1006 	.arg1_type	= ARG_PTR_TO_MEM,
1007 	.arg2_type	= ARG_CONST_SIZE,
1008 	.arg3_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
1009 	.arg4_type	= ARG_CONST_SIZE,
1010 	.arg5_type	= ARG_ANYTHING,
1011 };
1012 
1013 BPF_CALL_1(bpf_get_func_ip_tracing, void *, ctx)
1014 {
1015 	/* This helper call is inlined by verifier. */
1016 	return ((u64 *)ctx)[-2];
1017 }
1018 
1019 static const struct bpf_func_proto bpf_get_func_ip_proto_tracing = {
1020 	.func		= bpf_get_func_ip_tracing,
1021 	.gpl_only	= true,
1022 	.ret_type	= RET_INTEGER,
1023 	.arg1_type	= ARG_PTR_TO_CTX,
1024 };
1025 
1026 BPF_CALL_1(bpf_get_func_ip_kprobe, struct pt_regs *, regs)
1027 {
1028 	struct kprobe *kp = kprobe_running();
1029 
1030 	return kp ? (uintptr_t)kp->addr : 0;
1031 }
1032 
1033 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe = {
1034 	.func		= bpf_get_func_ip_kprobe,
1035 	.gpl_only	= true,
1036 	.ret_type	= RET_INTEGER,
1037 	.arg1_type	= ARG_PTR_TO_CTX,
1038 };
1039 
1040 BPF_CALL_1(bpf_get_func_ip_kprobe_multi, struct pt_regs *, regs)
1041 {
1042 	return bpf_kprobe_multi_entry_ip(current->bpf_ctx);
1043 }
1044 
1045 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe_multi = {
1046 	.func		= bpf_get_func_ip_kprobe_multi,
1047 	.gpl_only	= false,
1048 	.ret_type	= RET_INTEGER,
1049 	.arg1_type	= ARG_PTR_TO_CTX,
1050 };
1051 
1052 BPF_CALL_1(bpf_get_attach_cookie_kprobe_multi, struct pt_regs *, regs)
1053 {
1054 	return bpf_kprobe_multi_cookie(current->bpf_ctx);
1055 }
1056 
1057 static const struct bpf_func_proto bpf_get_attach_cookie_proto_kmulti = {
1058 	.func		= bpf_get_attach_cookie_kprobe_multi,
1059 	.gpl_only	= false,
1060 	.ret_type	= RET_INTEGER,
1061 	.arg1_type	= ARG_PTR_TO_CTX,
1062 };
1063 
1064 BPF_CALL_1(bpf_get_attach_cookie_trace, void *, ctx)
1065 {
1066 	struct bpf_trace_run_ctx *run_ctx;
1067 
1068 	run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx);
1069 	return run_ctx->bpf_cookie;
1070 }
1071 
1072 static const struct bpf_func_proto bpf_get_attach_cookie_proto_trace = {
1073 	.func		= bpf_get_attach_cookie_trace,
1074 	.gpl_only	= false,
1075 	.ret_type	= RET_INTEGER,
1076 	.arg1_type	= ARG_PTR_TO_CTX,
1077 };
1078 
1079 BPF_CALL_1(bpf_get_attach_cookie_pe, struct bpf_perf_event_data_kern *, ctx)
1080 {
1081 	return ctx->event->bpf_cookie;
1082 }
1083 
1084 static const struct bpf_func_proto bpf_get_attach_cookie_proto_pe = {
1085 	.func		= bpf_get_attach_cookie_pe,
1086 	.gpl_only	= false,
1087 	.ret_type	= RET_INTEGER,
1088 	.arg1_type	= ARG_PTR_TO_CTX,
1089 };
1090 
1091 BPF_CALL_3(bpf_get_branch_snapshot, void *, buf, u32, size, u64, flags)
1092 {
1093 #ifndef CONFIG_X86
1094 	return -ENOENT;
1095 #else
1096 	static const u32 br_entry_size = sizeof(struct perf_branch_entry);
1097 	u32 entry_cnt = size / br_entry_size;
1098 
1099 	entry_cnt = static_call(perf_snapshot_branch_stack)(buf, entry_cnt);
1100 
1101 	if (unlikely(flags))
1102 		return -EINVAL;
1103 
1104 	if (!entry_cnt)
1105 		return -ENOENT;
1106 
1107 	return entry_cnt * br_entry_size;
1108 #endif
1109 }
1110 
1111 static const struct bpf_func_proto bpf_get_branch_snapshot_proto = {
1112 	.func		= bpf_get_branch_snapshot,
1113 	.gpl_only	= true,
1114 	.ret_type	= RET_INTEGER,
1115 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
1116 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
1117 };
1118 
1119 BPF_CALL_3(get_func_arg, void *, ctx, u32, n, u64 *, value)
1120 {
1121 	/* This helper call is inlined by verifier. */
1122 	u64 nr_args = ((u64 *)ctx)[-1];
1123 
1124 	if ((u64) n >= nr_args)
1125 		return -EINVAL;
1126 	*value = ((u64 *)ctx)[n];
1127 	return 0;
1128 }
1129 
1130 static const struct bpf_func_proto bpf_get_func_arg_proto = {
1131 	.func		= get_func_arg,
1132 	.ret_type	= RET_INTEGER,
1133 	.arg1_type	= ARG_PTR_TO_CTX,
1134 	.arg2_type	= ARG_ANYTHING,
1135 	.arg3_type	= ARG_PTR_TO_LONG,
1136 };
1137 
1138 BPF_CALL_2(get_func_ret, void *, ctx, u64 *, value)
1139 {
1140 	/* This helper call is inlined by verifier. */
1141 	u64 nr_args = ((u64 *)ctx)[-1];
1142 
1143 	*value = ((u64 *)ctx)[nr_args];
1144 	return 0;
1145 }
1146 
1147 static const struct bpf_func_proto bpf_get_func_ret_proto = {
1148 	.func		= get_func_ret,
1149 	.ret_type	= RET_INTEGER,
1150 	.arg1_type	= ARG_PTR_TO_CTX,
1151 	.arg2_type	= ARG_PTR_TO_LONG,
1152 };
1153 
1154 BPF_CALL_1(get_func_arg_cnt, void *, ctx)
1155 {
1156 	/* This helper call is inlined by verifier. */
1157 	return ((u64 *)ctx)[-1];
1158 }
1159 
1160 static const struct bpf_func_proto bpf_get_func_arg_cnt_proto = {
1161 	.func		= get_func_arg_cnt,
1162 	.ret_type	= RET_INTEGER,
1163 	.arg1_type	= ARG_PTR_TO_CTX,
1164 };
1165 
1166 static const struct bpf_func_proto *
1167 bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1168 {
1169 	switch (func_id) {
1170 	case BPF_FUNC_map_lookup_elem:
1171 		return &bpf_map_lookup_elem_proto;
1172 	case BPF_FUNC_map_update_elem:
1173 		return &bpf_map_update_elem_proto;
1174 	case BPF_FUNC_map_delete_elem:
1175 		return &bpf_map_delete_elem_proto;
1176 	case BPF_FUNC_map_push_elem:
1177 		return &bpf_map_push_elem_proto;
1178 	case BPF_FUNC_map_pop_elem:
1179 		return &bpf_map_pop_elem_proto;
1180 	case BPF_FUNC_map_peek_elem:
1181 		return &bpf_map_peek_elem_proto;
1182 	case BPF_FUNC_ktime_get_ns:
1183 		return &bpf_ktime_get_ns_proto;
1184 	case BPF_FUNC_ktime_get_boot_ns:
1185 		return &bpf_ktime_get_boot_ns_proto;
1186 	case BPF_FUNC_tail_call:
1187 		return &bpf_tail_call_proto;
1188 	case BPF_FUNC_get_current_pid_tgid:
1189 		return &bpf_get_current_pid_tgid_proto;
1190 	case BPF_FUNC_get_current_task:
1191 		return &bpf_get_current_task_proto;
1192 	case BPF_FUNC_get_current_task_btf:
1193 		return &bpf_get_current_task_btf_proto;
1194 	case BPF_FUNC_task_pt_regs:
1195 		return &bpf_task_pt_regs_proto;
1196 	case BPF_FUNC_get_current_uid_gid:
1197 		return &bpf_get_current_uid_gid_proto;
1198 	case BPF_FUNC_get_current_comm:
1199 		return &bpf_get_current_comm_proto;
1200 	case BPF_FUNC_trace_printk:
1201 		return bpf_get_trace_printk_proto();
1202 	case BPF_FUNC_get_smp_processor_id:
1203 		return &bpf_get_smp_processor_id_proto;
1204 	case BPF_FUNC_get_numa_node_id:
1205 		return &bpf_get_numa_node_id_proto;
1206 	case BPF_FUNC_perf_event_read:
1207 		return &bpf_perf_event_read_proto;
1208 	case BPF_FUNC_current_task_under_cgroup:
1209 		return &bpf_current_task_under_cgroup_proto;
1210 	case BPF_FUNC_get_prandom_u32:
1211 		return &bpf_get_prandom_u32_proto;
1212 	case BPF_FUNC_probe_write_user:
1213 		return security_locked_down(LOCKDOWN_BPF_WRITE_USER) < 0 ?
1214 		       NULL : bpf_get_probe_write_proto();
1215 	case BPF_FUNC_probe_read_user:
1216 		return &bpf_probe_read_user_proto;
1217 	case BPF_FUNC_probe_read_kernel:
1218 		return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
1219 		       NULL : &bpf_probe_read_kernel_proto;
1220 	case BPF_FUNC_probe_read_user_str:
1221 		return &bpf_probe_read_user_str_proto;
1222 	case BPF_FUNC_probe_read_kernel_str:
1223 		return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
1224 		       NULL : &bpf_probe_read_kernel_str_proto;
1225 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
1226 	case BPF_FUNC_probe_read:
1227 		return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
1228 		       NULL : &bpf_probe_read_compat_proto;
1229 	case BPF_FUNC_probe_read_str:
1230 		return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
1231 		       NULL : &bpf_probe_read_compat_str_proto;
1232 #endif
1233 #ifdef CONFIG_CGROUPS
1234 	case BPF_FUNC_get_current_cgroup_id:
1235 		return &bpf_get_current_cgroup_id_proto;
1236 	case BPF_FUNC_get_current_ancestor_cgroup_id:
1237 		return &bpf_get_current_ancestor_cgroup_id_proto;
1238 #endif
1239 	case BPF_FUNC_send_signal:
1240 		return &bpf_send_signal_proto;
1241 	case BPF_FUNC_send_signal_thread:
1242 		return &bpf_send_signal_thread_proto;
1243 	case BPF_FUNC_perf_event_read_value:
1244 		return &bpf_perf_event_read_value_proto;
1245 	case BPF_FUNC_get_ns_current_pid_tgid:
1246 		return &bpf_get_ns_current_pid_tgid_proto;
1247 	case BPF_FUNC_ringbuf_output:
1248 		return &bpf_ringbuf_output_proto;
1249 	case BPF_FUNC_ringbuf_reserve:
1250 		return &bpf_ringbuf_reserve_proto;
1251 	case BPF_FUNC_ringbuf_submit:
1252 		return &bpf_ringbuf_submit_proto;
1253 	case BPF_FUNC_ringbuf_discard:
1254 		return &bpf_ringbuf_discard_proto;
1255 	case BPF_FUNC_ringbuf_query:
1256 		return &bpf_ringbuf_query_proto;
1257 	case BPF_FUNC_jiffies64:
1258 		return &bpf_jiffies64_proto;
1259 	case BPF_FUNC_get_task_stack:
1260 		return &bpf_get_task_stack_proto;
1261 	case BPF_FUNC_copy_from_user:
1262 		return prog->aux->sleepable ? &bpf_copy_from_user_proto : NULL;
1263 	case BPF_FUNC_copy_from_user_task:
1264 		return prog->aux->sleepable ? &bpf_copy_from_user_task_proto : NULL;
1265 	case BPF_FUNC_snprintf_btf:
1266 		return &bpf_snprintf_btf_proto;
1267 	case BPF_FUNC_per_cpu_ptr:
1268 		return &bpf_per_cpu_ptr_proto;
1269 	case BPF_FUNC_this_cpu_ptr:
1270 		return &bpf_this_cpu_ptr_proto;
1271 	case BPF_FUNC_task_storage_get:
1272 		return &bpf_task_storage_get_proto;
1273 	case BPF_FUNC_task_storage_delete:
1274 		return &bpf_task_storage_delete_proto;
1275 	case BPF_FUNC_for_each_map_elem:
1276 		return &bpf_for_each_map_elem_proto;
1277 	case BPF_FUNC_snprintf:
1278 		return &bpf_snprintf_proto;
1279 	case BPF_FUNC_get_func_ip:
1280 		return &bpf_get_func_ip_proto_tracing;
1281 	case BPF_FUNC_get_branch_snapshot:
1282 		return &bpf_get_branch_snapshot_proto;
1283 	case BPF_FUNC_find_vma:
1284 		return &bpf_find_vma_proto;
1285 	case BPF_FUNC_trace_vprintk:
1286 		return bpf_get_trace_vprintk_proto();
1287 	default:
1288 		return bpf_base_func_proto(func_id);
1289 	}
1290 }
1291 
1292 static const struct bpf_func_proto *
1293 kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1294 {
1295 	switch (func_id) {
1296 	case BPF_FUNC_perf_event_output:
1297 		return &bpf_perf_event_output_proto;
1298 	case BPF_FUNC_get_stackid:
1299 		return &bpf_get_stackid_proto;
1300 	case BPF_FUNC_get_stack:
1301 		return &bpf_get_stack_proto;
1302 #ifdef CONFIG_BPF_KPROBE_OVERRIDE
1303 	case BPF_FUNC_override_return:
1304 		return &bpf_override_return_proto;
1305 #endif
1306 	case BPF_FUNC_get_func_ip:
1307 		return prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI ?
1308 			&bpf_get_func_ip_proto_kprobe_multi :
1309 			&bpf_get_func_ip_proto_kprobe;
1310 	case BPF_FUNC_get_attach_cookie:
1311 		return prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI ?
1312 			&bpf_get_attach_cookie_proto_kmulti :
1313 			&bpf_get_attach_cookie_proto_trace;
1314 	default:
1315 		return bpf_tracing_func_proto(func_id, prog);
1316 	}
1317 }
1318 
1319 /* bpf+kprobe programs can access fields of 'struct pt_regs' */
1320 static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
1321 					const struct bpf_prog *prog,
1322 					struct bpf_insn_access_aux *info)
1323 {
1324 	if (off < 0 || off >= sizeof(struct pt_regs))
1325 		return false;
1326 	if (type != BPF_READ)
1327 		return false;
1328 	if (off % size != 0)
1329 		return false;
1330 	/*
1331 	 * Assertion for 32 bit to make sure last 8 byte access
1332 	 * (BPF_DW) to the last 4 byte member is disallowed.
1333 	 */
1334 	if (off + size > sizeof(struct pt_regs))
1335 		return false;
1336 
1337 	return true;
1338 }
1339 
1340 const struct bpf_verifier_ops kprobe_verifier_ops = {
1341 	.get_func_proto  = kprobe_prog_func_proto,
1342 	.is_valid_access = kprobe_prog_is_valid_access,
1343 };
1344 
1345 const struct bpf_prog_ops kprobe_prog_ops = {
1346 };
1347 
1348 BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map,
1349 	   u64, flags, void *, data, u64, size)
1350 {
1351 	struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1352 
1353 	/*
1354 	 * r1 points to perf tracepoint buffer where first 8 bytes are hidden
1355 	 * from bpf program and contain a pointer to 'struct pt_regs'. Fetch it
1356 	 * from there and call the same bpf_perf_event_output() helper inline.
1357 	 */
1358 	return ____bpf_perf_event_output(regs, map, flags, data, size);
1359 }
1360 
1361 static const struct bpf_func_proto bpf_perf_event_output_proto_tp = {
1362 	.func		= bpf_perf_event_output_tp,
1363 	.gpl_only	= true,
1364 	.ret_type	= RET_INTEGER,
1365 	.arg1_type	= ARG_PTR_TO_CTX,
1366 	.arg2_type	= ARG_CONST_MAP_PTR,
1367 	.arg3_type	= ARG_ANYTHING,
1368 	.arg4_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
1369 	.arg5_type	= ARG_CONST_SIZE_OR_ZERO,
1370 };
1371 
1372 BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map,
1373 	   u64, flags)
1374 {
1375 	struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1376 
1377 	/*
1378 	 * Same comment as in bpf_perf_event_output_tp(), only that this time
1379 	 * the other helper's function body cannot be inlined due to being
1380 	 * external, thus we need to call raw helper function.
1381 	 */
1382 	return bpf_get_stackid((unsigned long) regs, (unsigned long) map,
1383 			       flags, 0, 0);
1384 }
1385 
1386 static const struct bpf_func_proto bpf_get_stackid_proto_tp = {
1387 	.func		= bpf_get_stackid_tp,
1388 	.gpl_only	= true,
1389 	.ret_type	= RET_INTEGER,
1390 	.arg1_type	= ARG_PTR_TO_CTX,
1391 	.arg2_type	= ARG_CONST_MAP_PTR,
1392 	.arg3_type	= ARG_ANYTHING,
1393 };
1394 
1395 BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size,
1396 	   u64, flags)
1397 {
1398 	struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1399 
1400 	return bpf_get_stack((unsigned long) regs, (unsigned long) buf,
1401 			     (unsigned long) size, flags, 0);
1402 }
1403 
1404 static const struct bpf_func_proto bpf_get_stack_proto_tp = {
1405 	.func		= bpf_get_stack_tp,
1406 	.gpl_only	= true,
1407 	.ret_type	= RET_INTEGER,
1408 	.arg1_type	= ARG_PTR_TO_CTX,
1409 	.arg2_type	= ARG_PTR_TO_UNINIT_MEM,
1410 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
1411 	.arg4_type	= ARG_ANYTHING,
1412 };
1413 
1414 static const struct bpf_func_proto *
1415 tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1416 {
1417 	switch (func_id) {
1418 	case BPF_FUNC_perf_event_output:
1419 		return &bpf_perf_event_output_proto_tp;
1420 	case BPF_FUNC_get_stackid:
1421 		return &bpf_get_stackid_proto_tp;
1422 	case BPF_FUNC_get_stack:
1423 		return &bpf_get_stack_proto_tp;
1424 	case BPF_FUNC_get_attach_cookie:
1425 		return &bpf_get_attach_cookie_proto_trace;
1426 	default:
1427 		return bpf_tracing_func_proto(func_id, prog);
1428 	}
1429 }
1430 
1431 static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type,
1432 				    const struct bpf_prog *prog,
1433 				    struct bpf_insn_access_aux *info)
1434 {
1435 	if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE)
1436 		return false;
1437 	if (type != BPF_READ)
1438 		return false;
1439 	if (off % size != 0)
1440 		return false;
1441 
1442 	BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(__u64));
1443 	return true;
1444 }
1445 
1446 const struct bpf_verifier_ops tracepoint_verifier_ops = {
1447 	.get_func_proto  = tp_prog_func_proto,
1448 	.is_valid_access = tp_prog_is_valid_access,
1449 };
1450 
1451 const struct bpf_prog_ops tracepoint_prog_ops = {
1452 };
1453 
1454 BPF_CALL_3(bpf_perf_prog_read_value, struct bpf_perf_event_data_kern *, ctx,
1455 	   struct bpf_perf_event_value *, buf, u32, size)
1456 {
1457 	int err = -EINVAL;
1458 
1459 	if (unlikely(size != sizeof(struct bpf_perf_event_value)))
1460 		goto clear;
1461 	err = perf_event_read_local(ctx->event, &buf->counter, &buf->enabled,
1462 				    &buf->running);
1463 	if (unlikely(err))
1464 		goto clear;
1465 	return 0;
1466 clear:
1467 	memset(buf, 0, size);
1468 	return err;
1469 }
1470 
1471 static const struct bpf_func_proto bpf_perf_prog_read_value_proto = {
1472          .func           = bpf_perf_prog_read_value,
1473          .gpl_only       = true,
1474          .ret_type       = RET_INTEGER,
1475          .arg1_type      = ARG_PTR_TO_CTX,
1476          .arg2_type      = ARG_PTR_TO_UNINIT_MEM,
1477          .arg3_type      = ARG_CONST_SIZE,
1478 };
1479 
1480 BPF_CALL_4(bpf_read_branch_records, struct bpf_perf_event_data_kern *, ctx,
1481 	   void *, buf, u32, size, u64, flags)
1482 {
1483 	static const u32 br_entry_size = sizeof(struct perf_branch_entry);
1484 	struct perf_branch_stack *br_stack = ctx->data->br_stack;
1485 	u32 to_copy;
1486 
1487 	if (unlikely(flags & ~BPF_F_GET_BRANCH_RECORDS_SIZE))
1488 		return -EINVAL;
1489 
1490 	if (unlikely(!br_stack))
1491 		return -ENOENT;
1492 
1493 	if (flags & BPF_F_GET_BRANCH_RECORDS_SIZE)
1494 		return br_stack->nr * br_entry_size;
1495 
1496 	if (!buf || (size % br_entry_size != 0))
1497 		return -EINVAL;
1498 
1499 	to_copy = min_t(u32, br_stack->nr * br_entry_size, size);
1500 	memcpy(buf, br_stack->entries, to_copy);
1501 
1502 	return to_copy;
1503 }
1504 
1505 static const struct bpf_func_proto bpf_read_branch_records_proto = {
1506 	.func           = bpf_read_branch_records,
1507 	.gpl_only       = true,
1508 	.ret_type       = RET_INTEGER,
1509 	.arg1_type      = ARG_PTR_TO_CTX,
1510 	.arg2_type      = ARG_PTR_TO_MEM_OR_NULL,
1511 	.arg3_type      = ARG_CONST_SIZE_OR_ZERO,
1512 	.arg4_type      = ARG_ANYTHING,
1513 };
1514 
1515 static const struct bpf_func_proto *
1516 pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1517 {
1518 	switch (func_id) {
1519 	case BPF_FUNC_perf_event_output:
1520 		return &bpf_perf_event_output_proto_tp;
1521 	case BPF_FUNC_get_stackid:
1522 		return &bpf_get_stackid_proto_pe;
1523 	case BPF_FUNC_get_stack:
1524 		return &bpf_get_stack_proto_pe;
1525 	case BPF_FUNC_perf_prog_read_value:
1526 		return &bpf_perf_prog_read_value_proto;
1527 	case BPF_FUNC_read_branch_records:
1528 		return &bpf_read_branch_records_proto;
1529 	case BPF_FUNC_get_attach_cookie:
1530 		return &bpf_get_attach_cookie_proto_pe;
1531 	default:
1532 		return bpf_tracing_func_proto(func_id, prog);
1533 	}
1534 }
1535 
1536 /*
1537  * bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp
1538  * to avoid potential recursive reuse issue when/if tracepoints are added
1539  * inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack.
1540  *
1541  * Since raw tracepoints run despite bpf_prog_active, support concurrent usage
1542  * in normal, irq, and nmi context.
1543  */
1544 struct bpf_raw_tp_regs {
1545 	struct pt_regs regs[3];
1546 };
1547 static DEFINE_PER_CPU(struct bpf_raw_tp_regs, bpf_raw_tp_regs);
1548 static DEFINE_PER_CPU(int, bpf_raw_tp_nest_level);
1549 static struct pt_regs *get_bpf_raw_tp_regs(void)
1550 {
1551 	struct bpf_raw_tp_regs *tp_regs = this_cpu_ptr(&bpf_raw_tp_regs);
1552 	int nest_level = this_cpu_inc_return(bpf_raw_tp_nest_level);
1553 
1554 	if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(tp_regs->regs))) {
1555 		this_cpu_dec(bpf_raw_tp_nest_level);
1556 		return ERR_PTR(-EBUSY);
1557 	}
1558 
1559 	return &tp_regs->regs[nest_level - 1];
1560 }
1561 
1562 static void put_bpf_raw_tp_regs(void)
1563 {
1564 	this_cpu_dec(bpf_raw_tp_nest_level);
1565 }
1566 
1567 BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args,
1568 	   struct bpf_map *, map, u64, flags, void *, data, u64, size)
1569 {
1570 	struct pt_regs *regs = get_bpf_raw_tp_regs();
1571 	int ret;
1572 
1573 	if (IS_ERR(regs))
1574 		return PTR_ERR(regs);
1575 
1576 	perf_fetch_caller_regs(regs);
1577 	ret = ____bpf_perf_event_output(regs, map, flags, data, size);
1578 
1579 	put_bpf_raw_tp_regs();
1580 	return ret;
1581 }
1582 
1583 static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = {
1584 	.func		= bpf_perf_event_output_raw_tp,
1585 	.gpl_only	= true,
1586 	.ret_type	= RET_INTEGER,
1587 	.arg1_type	= ARG_PTR_TO_CTX,
1588 	.arg2_type	= ARG_CONST_MAP_PTR,
1589 	.arg3_type	= ARG_ANYTHING,
1590 	.arg4_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
1591 	.arg5_type	= ARG_CONST_SIZE_OR_ZERO,
1592 };
1593 
1594 extern const struct bpf_func_proto bpf_skb_output_proto;
1595 extern const struct bpf_func_proto bpf_xdp_output_proto;
1596 extern const struct bpf_func_proto bpf_xdp_get_buff_len_trace_proto;
1597 
1598 BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args,
1599 	   struct bpf_map *, map, u64, flags)
1600 {
1601 	struct pt_regs *regs = get_bpf_raw_tp_regs();
1602 	int ret;
1603 
1604 	if (IS_ERR(regs))
1605 		return PTR_ERR(regs);
1606 
1607 	perf_fetch_caller_regs(regs);
1608 	/* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */
1609 	ret = bpf_get_stackid((unsigned long) regs, (unsigned long) map,
1610 			      flags, 0, 0);
1611 	put_bpf_raw_tp_regs();
1612 	return ret;
1613 }
1614 
1615 static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = {
1616 	.func		= bpf_get_stackid_raw_tp,
1617 	.gpl_only	= true,
1618 	.ret_type	= RET_INTEGER,
1619 	.arg1_type	= ARG_PTR_TO_CTX,
1620 	.arg2_type	= ARG_CONST_MAP_PTR,
1621 	.arg3_type	= ARG_ANYTHING,
1622 };
1623 
1624 BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args,
1625 	   void *, buf, u32, size, u64, flags)
1626 {
1627 	struct pt_regs *regs = get_bpf_raw_tp_regs();
1628 	int ret;
1629 
1630 	if (IS_ERR(regs))
1631 		return PTR_ERR(regs);
1632 
1633 	perf_fetch_caller_regs(regs);
1634 	ret = bpf_get_stack((unsigned long) regs, (unsigned long) buf,
1635 			    (unsigned long) size, flags, 0);
1636 	put_bpf_raw_tp_regs();
1637 	return ret;
1638 }
1639 
1640 static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = {
1641 	.func		= bpf_get_stack_raw_tp,
1642 	.gpl_only	= true,
1643 	.ret_type	= RET_INTEGER,
1644 	.arg1_type	= ARG_PTR_TO_CTX,
1645 	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
1646 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
1647 	.arg4_type	= ARG_ANYTHING,
1648 };
1649 
1650 static const struct bpf_func_proto *
1651 raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1652 {
1653 	switch (func_id) {
1654 	case BPF_FUNC_perf_event_output:
1655 		return &bpf_perf_event_output_proto_raw_tp;
1656 	case BPF_FUNC_get_stackid:
1657 		return &bpf_get_stackid_proto_raw_tp;
1658 	case BPF_FUNC_get_stack:
1659 		return &bpf_get_stack_proto_raw_tp;
1660 	default:
1661 		return bpf_tracing_func_proto(func_id, prog);
1662 	}
1663 }
1664 
1665 const struct bpf_func_proto *
1666 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1667 {
1668 	const struct bpf_func_proto *fn;
1669 
1670 	switch (func_id) {
1671 #ifdef CONFIG_NET
1672 	case BPF_FUNC_skb_output:
1673 		return &bpf_skb_output_proto;
1674 	case BPF_FUNC_xdp_output:
1675 		return &bpf_xdp_output_proto;
1676 	case BPF_FUNC_skc_to_tcp6_sock:
1677 		return &bpf_skc_to_tcp6_sock_proto;
1678 	case BPF_FUNC_skc_to_tcp_sock:
1679 		return &bpf_skc_to_tcp_sock_proto;
1680 	case BPF_FUNC_skc_to_tcp_timewait_sock:
1681 		return &bpf_skc_to_tcp_timewait_sock_proto;
1682 	case BPF_FUNC_skc_to_tcp_request_sock:
1683 		return &bpf_skc_to_tcp_request_sock_proto;
1684 	case BPF_FUNC_skc_to_udp6_sock:
1685 		return &bpf_skc_to_udp6_sock_proto;
1686 	case BPF_FUNC_skc_to_unix_sock:
1687 		return &bpf_skc_to_unix_sock_proto;
1688 	case BPF_FUNC_sk_storage_get:
1689 		return &bpf_sk_storage_get_tracing_proto;
1690 	case BPF_FUNC_sk_storage_delete:
1691 		return &bpf_sk_storage_delete_tracing_proto;
1692 	case BPF_FUNC_sock_from_file:
1693 		return &bpf_sock_from_file_proto;
1694 	case BPF_FUNC_get_socket_cookie:
1695 		return &bpf_get_socket_ptr_cookie_proto;
1696 	case BPF_FUNC_xdp_get_buff_len:
1697 		return &bpf_xdp_get_buff_len_trace_proto;
1698 #endif
1699 	case BPF_FUNC_seq_printf:
1700 		return prog->expected_attach_type == BPF_TRACE_ITER ?
1701 		       &bpf_seq_printf_proto :
1702 		       NULL;
1703 	case BPF_FUNC_seq_write:
1704 		return prog->expected_attach_type == BPF_TRACE_ITER ?
1705 		       &bpf_seq_write_proto :
1706 		       NULL;
1707 	case BPF_FUNC_seq_printf_btf:
1708 		return prog->expected_attach_type == BPF_TRACE_ITER ?
1709 		       &bpf_seq_printf_btf_proto :
1710 		       NULL;
1711 	case BPF_FUNC_d_path:
1712 		return &bpf_d_path_proto;
1713 	case BPF_FUNC_get_func_arg:
1714 		return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_proto : NULL;
1715 	case BPF_FUNC_get_func_ret:
1716 		return bpf_prog_has_trampoline(prog) ? &bpf_get_func_ret_proto : NULL;
1717 	case BPF_FUNC_get_func_arg_cnt:
1718 		return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_cnt_proto : NULL;
1719 	default:
1720 		fn = raw_tp_prog_func_proto(func_id, prog);
1721 		if (!fn && prog->expected_attach_type == BPF_TRACE_ITER)
1722 			fn = bpf_iter_get_func_proto(func_id, prog);
1723 		return fn;
1724 	}
1725 }
1726 
1727 static bool raw_tp_prog_is_valid_access(int off, int size,
1728 					enum bpf_access_type type,
1729 					const struct bpf_prog *prog,
1730 					struct bpf_insn_access_aux *info)
1731 {
1732 	return bpf_tracing_ctx_access(off, size, type);
1733 }
1734 
1735 static bool tracing_prog_is_valid_access(int off, int size,
1736 					 enum bpf_access_type type,
1737 					 const struct bpf_prog *prog,
1738 					 struct bpf_insn_access_aux *info)
1739 {
1740 	return bpf_tracing_btf_ctx_access(off, size, type, prog, info);
1741 }
1742 
1743 int __weak bpf_prog_test_run_tracing(struct bpf_prog *prog,
1744 				     const union bpf_attr *kattr,
1745 				     union bpf_attr __user *uattr)
1746 {
1747 	return -ENOTSUPP;
1748 }
1749 
1750 const struct bpf_verifier_ops raw_tracepoint_verifier_ops = {
1751 	.get_func_proto  = raw_tp_prog_func_proto,
1752 	.is_valid_access = raw_tp_prog_is_valid_access,
1753 };
1754 
1755 const struct bpf_prog_ops raw_tracepoint_prog_ops = {
1756 #ifdef CONFIG_NET
1757 	.test_run = bpf_prog_test_run_raw_tp,
1758 #endif
1759 };
1760 
1761 const struct bpf_verifier_ops tracing_verifier_ops = {
1762 	.get_func_proto  = tracing_prog_func_proto,
1763 	.is_valid_access = tracing_prog_is_valid_access,
1764 };
1765 
1766 const struct bpf_prog_ops tracing_prog_ops = {
1767 	.test_run = bpf_prog_test_run_tracing,
1768 };
1769 
1770 static bool raw_tp_writable_prog_is_valid_access(int off, int size,
1771 						 enum bpf_access_type type,
1772 						 const struct bpf_prog *prog,
1773 						 struct bpf_insn_access_aux *info)
1774 {
1775 	if (off == 0) {
1776 		if (size != sizeof(u64) || type != BPF_READ)
1777 			return false;
1778 		info->reg_type = PTR_TO_TP_BUFFER;
1779 	}
1780 	return raw_tp_prog_is_valid_access(off, size, type, prog, info);
1781 }
1782 
1783 const struct bpf_verifier_ops raw_tracepoint_writable_verifier_ops = {
1784 	.get_func_proto  = raw_tp_prog_func_proto,
1785 	.is_valid_access = raw_tp_writable_prog_is_valid_access,
1786 };
1787 
1788 const struct bpf_prog_ops raw_tracepoint_writable_prog_ops = {
1789 };
1790 
1791 static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
1792 				    const struct bpf_prog *prog,
1793 				    struct bpf_insn_access_aux *info)
1794 {
1795 	const int size_u64 = sizeof(u64);
1796 
1797 	if (off < 0 || off >= sizeof(struct bpf_perf_event_data))
1798 		return false;
1799 	if (type != BPF_READ)
1800 		return false;
1801 	if (off % size != 0) {
1802 		if (sizeof(unsigned long) != 4)
1803 			return false;
1804 		if (size != 8)
1805 			return false;
1806 		if (off % size != 4)
1807 			return false;
1808 	}
1809 
1810 	switch (off) {
1811 	case bpf_ctx_range(struct bpf_perf_event_data, sample_period):
1812 		bpf_ctx_record_field_size(info, size_u64);
1813 		if (!bpf_ctx_narrow_access_ok(off, size, size_u64))
1814 			return false;
1815 		break;
1816 	case bpf_ctx_range(struct bpf_perf_event_data, addr):
1817 		bpf_ctx_record_field_size(info, size_u64);
1818 		if (!bpf_ctx_narrow_access_ok(off, size, size_u64))
1819 			return false;
1820 		break;
1821 	default:
1822 		if (size != sizeof(long))
1823 			return false;
1824 	}
1825 
1826 	return true;
1827 }
1828 
1829 static u32 pe_prog_convert_ctx_access(enum bpf_access_type type,
1830 				      const struct bpf_insn *si,
1831 				      struct bpf_insn *insn_buf,
1832 				      struct bpf_prog *prog, u32 *target_size)
1833 {
1834 	struct bpf_insn *insn = insn_buf;
1835 
1836 	switch (si->off) {
1837 	case offsetof(struct bpf_perf_event_data, sample_period):
1838 		*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
1839 						       data), si->dst_reg, si->src_reg,
1840 				      offsetof(struct bpf_perf_event_data_kern, data));
1841 		*insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg,
1842 				      bpf_target_off(struct perf_sample_data, period, 8,
1843 						     target_size));
1844 		break;
1845 	case offsetof(struct bpf_perf_event_data, addr):
1846 		*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
1847 						       data), si->dst_reg, si->src_reg,
1848 				      offsetof(struct bpf_perf_event_data_kern, data));
1849 		*insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg,
1850 				      bpf_target_off(struct perf_sample_data, addr, 8,
1851 						     target_size));
1852 		break;
1853 	default:
1854 		*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
1855 						       regs), si->dst_reg, si->src_reg,
1856 				      offsetof(struct bpf_perf_event_data_kern, regs));
1857 		*insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg,
1858 				      si->off);
1859 		break;
1860 	}
1861 
1862 	return insn - insn_buf;
1863 }
1864 
1865 const struct bpf_verifier_ops perf_event_verifier_ops = {
1866 	.get_func_proto		= pe_prog_func_proto,
1867 	.is_valid_access	= pe_prog_is_valid_access,
1868 	.convert_ctx_access	= pe_prog_convert_ctx_access,
1869 };
1870 
1871 const struct bpf_prog_ops perf_event_prog_ops = {
1872 };
1873 
1874 static DEFINE_MUTEX(bpf_event_mutex);
1875 
1876 #define BPF_TRACE_MAX_PROGS 64
1877 
1878 int perf_event_attach_bpf_prog(struct perf_event *event,
1879 			       struct bpf_prog *prog,
1880 			       u64 bpf_cookie)
1881 {
1882 	struct bpf_prog_array *old_array;
1883 	struct bpf_prog_array *new_array;
1884 	int ret = -EEXIST;
1885 
1886 	/*
1887 	 * Kprobe override only works if they are on the function entry,
1888 	 * and only if they are on the opt-in list.
1889 	 */
1890 	if (prog->kprobe_override &&
1891 	    (!trace_kprobe_on_func_entry(event->tp_event) ||
1892 	     !trace_kprobe_error_injectable(event->tp_event)))
1893 		return -EINVAL;
1894 
1895 	mutex_lock(&bpf_event_mutex);
1896 
1897 	if (event->prog)
1898 		goto unlock;
1899 
1900 	old_array = bpf_event_rcu_dereference(event->tp_event->prog_array);
1901 	if (old_array &&
1902 	    bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) {
1903 		ret = -E2BIG;
1904 		goto unlock;
1905 	}
1906 
1907 	ret = bpf_prog_array_copy(old_array, NULL, prog, bpf_cookie, &new_array);
1908 	if (ret < 0)
1909 		goto unlock;
1910 
1911 	/* set the new array to event->tp_event and set event->prog */
1912 	event->prog = prog;
1913 	event->bpf_cookie = bpf_cookie;
1914 	rcu_assign_pointer(event->tp_event->prog_array, new_array);
1915 	bpf_prog_array_free(old_array);
1916 
1917 unlock:
1918 	mutex_unlock(&bpf_event_mutex);
1919 	return ret;
1920 }
1921 
1922 void perf_event_detach_bpf_prog(struct perf_event *event)
1923 {
1924 	struct bpf_prog_array *old_array;
1925 	struct bpf_prog_array *new_array;
1926 	int ret;
1927 
1928 	mutex_lock(&bpf_event_mutex);
1929 
1930 	if (!event->prog)
1931 		goto unlock;
1932 
1933 	old_array = bpf_event_rcu_dereference(event->tp_event->prog_array);
1934 	ret = bpf_prog_array_copy(old_array, event->prog, NULL, 0, &new_array);
1935 	if (ret == -ENOENT)
1936 		goto unlock;
1937 	if (ret < 0) {
1938 		bpf_prog_array_delete_safe(old_array, event->prog);
1939 	} else {
1940 		rcu_assign_pointer(event->tp_event->prog_array, new_array);
1941 		bpf_prog_array_free(old_array);
1942 	}
1943 
1944 	bpf_prog_put(event->prog);
1945 	event->prog = NULL;
1946 
1947 unlock:
1948 	mutex_unlock(&bpf_event_mutex);
1949 }
1950 
1951 int perf_event_query_prog_array(struct perf_event *event, void __user *info)
1952 {
1953 	struct perf_event_query_bpf __user *uquery = info;
1954 	struct perf_event_query_bpf query = {};
1955 	struct bpf_prog_array *progs;
1956 	u32 *ids, prog_cnt, ids_len;
1957 	int ret;
1958 
1959 	if (!perfmon_capable())
1960 		return -EPERM;
1961 	if (event->attr.type != PERF_TYPE_TRACEPOINT)
1962 		return -EINVAL;
1963 	if (copy_from_user(&query, uquery, sizeof(query)))
1964 		return -EFAULT;
1965 
1966 	ids_len = query.ids_len;
1967 	if (ids_len > BPF_TRACE_MAX_PROGS)
1968 		return -E2BIG;
1969 	ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN);
1970 	if (!ids)
1971 		return -ENOMEM;
1972 	/*
1973 	 * The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which
1974 	 * is required when user only wants to check for uquery->prog_cnt.
1975 	 * There is no need to check for it since the case is handled
1976 	 * gracefully in bpf_prog_array_copy_info.
1977 	 */
1978 
1979 	mutex_lock(&bpf_event_mutex);
1980 	progs = bpf_event_rcu_dereference(event->tp_event->prog_array);
1981 	ret = bpf_prog_array_copy_info(progs, ids, ids_len, &prog_cnt);
1982 	mutex_unlock(&bpf_event_mutex);
1983 
1984 	if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) ||
1985 	    copy_to_user(uquery->ids, ids, ids_len * sizeof(u32)))
1986 		ret = -EFAULT;
1987 
1988 	kfree(ids);
1989 	return ret;
1990 }
1991 
1992 extern struct bpf_raw_event_map __start__bpf_raw_tp[];
1993 extern struct bpf_raw_event_map __stop__bpf_raw_tp[];
1994 
1995 struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name)
1996 {
1997 	struct bpf_raw_event_map *btp = __start__bpf_raw_tp;
1998 
1999 	for (; btp < __stop__bpf_raw_tp; btp++) {
2000 		if (!strcmp(btp->tp->name, name))
2001 			return btp;
2002 	}
2003 
2004 	return bpf_get_raw_tracepoint_module(name);
2005 }
2006 
2007 void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp)
2008 {
2009 	struct module *mod;
2010 
2011 	preempt_disable();
2012 	mod = __module_address((unsigned long)btp);
2013 	module_put(mod);
2014 	preempt_enable();
2015 }
2016 
2017 static __always_inline
2018 void __bpf_trace_run(struct bpf_prog *prog, u64 *args)
2019 {
2020 	cant_sleep();
2021 	rcu_read_lock();
2022 	(void) bpf_prog_run(prog, args);
2023 	rcu_read_unlock();
2024 }
2025 
2026 #define UNPACK(...)			__VA_ARGS__
2027 #define REPEAT_1(FN, DL, X, ...)	FN(X)
2028 #define REPEAT_2(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__)
2029 #define REPEAT_3(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_2(FN, DL, __VA_ARGS__)
2030 #define REPEAT_4(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_3(FN, DL, __VA_ARGS__)
2031 #define REPEAT_5(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_4(FN, DL, __VA_ARGS__)
2032 #define REPEAT_6(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_5(FN, DL, __VA_ARGS__)
2033 #define REPEAT_7(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_6(FN, DL, __VA_ARGS__)
2034 #define REPEAT_8(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_7(FN, DL, __VA_ARGS__)
2035 #define REPEAT_9(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_8(FN, DL, __VA_ARGS__)
2036 #define REPEAT_10(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_9(FN, DL, __VA_ARGS__)
2037 #define REPEAT_11(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_10(FN, DL, __VA_ARGS__)
2038 #define REPEAT_12(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_11(FN, DL, __VA_ARGS__)
2039 #define REPEAT(X, FN, DL, ...)		REPEAT_##X(FN, DL, __VA_ARGS__)
2040 
2041 #define SARG(X)		u64 arg##X
2042 #define COPY(X)		args[X] = arg##X
2043 
2044 #define __DL_COM	(,)
2045 #define __DL_SEM	(;)
2046 
2047 #define __SEQ_0_11	0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11
2048 
2049 #define BPF_TRACE_DEFN_x(x)						\
2050 	void bpf_trace_run##x(struct bpf_prog *prog,			\
2051 			      REPEAT(x, SARG, __DL_COM, __SEQ_0_11))	\
2052 	{								\
2053 		u64 args[x];						\
2054 		REPEAT(x, COPY, __DL_SEM, __SEQ_0_11);			\
2055 		__bpf_trace_run(prog, args);				\
2056 	}								\
2057 	EXPORT_SYMBOL_GPL(bpf_trace_run##x)
2058 BPF_TRACE_DEFN_x(1);
2059 BPF_TRACE_DEFN_x(2);
2060 BPF_TRACE_DEFN_x(3);
2061 BPF_TRACE_DEFN_x(4);
2062 BPF_TRACE_DEFN_x(5);
2063 BPF_TRACE_DEFN_x(6);
2064 BPF_TRACE_DEFN_x(7);
2065 BPF_TRACE_DEFN_x(8);
2066 BPF_TRACE_DEFN_x(9);
2067 BPF_TRACE_DEFN_x(10);
2068 BPF_TRACE_DEFN_x(11);
2069 BPF_TRACE_DEFN_x(12);
2070 
2071 static int __bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog)
2072 {
2073 	struct tracepoint *tp = btp->tp;
2074 
2075 	/*
2076 	 * check that program doesn't access arguments beyond what's
2077 	 * available in this tracepoint
2078 	 */
2079 	if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64))
2080 		return -EINVAL;
2081 
2082 	if (prog->aux->max_tp_access > btp->writable_size)
2083 		return -EINVAL;
2084 
2085 	return tracepoint_probe_register_may_exist(tp, (void *)btp->bpf_func,
2086 						   prog);
2087 }
2088 
2089 int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog)
2090 {
2091 	return __bpf_probe_register(btp, prog);
2092 }
2093 
2094 int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_prog *prog)
2095 {
2096 	return tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, prog);
2097 }
2098 
2099 int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id,
2100 			    u32 *fd_type, const char **buf,
2101 			    u64 *probe_offset, u64 *probe_addr)
2102 {
2103 	bool is_tracepoint, is_syscall_tp;
2104 	struct bpf_prog *prog;
2105 	int flags, err = 0;
2106 
2107 	prog = event->prog;
2108 	if (!prog)
2109 		return -ENOENT;
2110 
2111 	/* not supporting BPF_PROG_TYPE_PERF_EVENT yet */
2112 	if (prog->type == BPF_PROG_TYPE_PERF_EVENT)
2113 		return -EOPNOTSUPP;
2114 
2115 	*prog_id = prog->aux->id;
2116 	flags = event->tp_event->flags;
2117 	is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT;
2118 	is_syscall_tp = is_syscall_trace_event(event->tp_event);
2119 
2120 	if (is_tracepoint || is_syscall_tp) {
2121 		*buf = is_tracepoint ? event->tp_event->tp->name
2122 				     : event->tp_event->name;
2123 		*fd_type = BPF_FD_TYPE_TRACEPOINT;
2124 		*probe_offset = 0x0;
2125 		*probe_addr = 0x0;
2126 	} else {
2127 		/* kprobe/uprobe */
2128 		err = -EOPNOTSUPP;
2129 #ifdef CONFIG_KPROBE_EVENTS
2130 		if (flags & TRACE_EVENT_FL_KPROBE)
2131 			err = bpf_get_kprobe_info(event, fd_type, buf,
2132 						  probe_offset, probe_addr,
2133 						  event->attr.type == PERF_TYPE_TRACEPOINT);
2134 #endif
2135 #ifdef CONFIG_UPROBE_EVENTS
2136 		if (flags & TRACE_EVENT_FL_UPROBE)
2137 			err = bpf_get_uprobe_info(event, fd_type, buf,
2138 						  probe_offset,
2139 						  event->attr.type == PERF_TYPE_TRACEPOINT);
2140 #endif
2141 	}
2142 
2143 	return err;
2144 }
2145 
2146 static int __init send_signal_irq_work_init(void)
2147 {
2148 	int cpu;
2149 	struct send_signal_irq_work *work;
2150 
2151 	for_each_possible_cpu(cpu) {
2152 		work = per_cpu_ptr(&send_signal_work, cpu);
2153 		init_irq_work(&work->irq_work, do_bpf_send_signal);
2154 	}
2155 	return 0;
2156 }
2157 
2158 subsys_initcall(send_signal_irq_work_init);
2159 
2160 #ifdef CONFIG_MODULES
2161 static int bpf_event_notify(struct notifier_block *nb, unsigned long op,
2162 			    void *module)
2163 {
2164 	struct bpf_trace_module *btm, *tmp;
2165 	struct module *mod = module;
2166 	int ret = 0;
2167 
2168 	if (mod->num_bpf_raw_events == 0 ||
2169 	    (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING))
2170 		goto out;
2171 
2172 	mutex_lock(&bpf_module_mutex);
2173 
2174 	switch (op) {
2175 	case MODULE_STATE_COMING:
2176 		btm = kzalloc(sizeof(*btm), GFP_KERNEL);
2177 		if (btm) {
2178 			btm->module = module;
2179 			list_add(&btm->list, &bpf_trace_modules);
2180 		} else {
2181 			ret = -ENOMEM;
2182 		}
2183 		break;
2184 	case MODULE_STATE_GOING:
2185 		list_for_each_entry_safe(btm, tmp, &bpf_trace_modules, list) {
2186 			if (btm->module == module) {
2187 				list_del(&btm->list);
2188 				kfree(btm);
2189 				break;
2190 			}
2191 		}
2192 		break;
2193 	}
2194 
2195 	mutex_unlock(&bpf_module_mutex);
2196 
2197 out:
2198 	return notifier_from_errno(ret);
2199 }
2200 
2201 static struct notifier_block bpf_module_nb = {
2202 	.notifier_call = bpf_event_notify,
2203 };
2204 
2205 static int __init bpf_event_init(void)
2206 {
2207 	register_module_notifier(&bpf_module_nb);
2208 	return 0;
2209 }
2210 
2211 fs_initcall(bpf_event_init);
2212 #endif /* CONFIG_MODULES */
2213 
2214 #ifdef CONFIG_FPROBE
2215 struct bpf_kprobe_multi_link {
2216 	struct bpf_link link;
2217 	struct fprobe fp;
2218 	unsigned long *addrs;
2219 	u64 *cookies;
2220 	u32 cnt;
2221 };
2222 
2223 struct bpf_kprobe_multi_run_ctx {
2224 	struct bpf_run_ctx run_ctx;
2225 	struct bpf_kprobe_multi_link *link;
2226 	unsigned long entry_ip;
2227 };
2228 
2229 static void bpf_kprobe_multi_link_release(struct bpf_link *link)
2230 {
2231 	struct bpf_kprobe_multi_link *kmulti_link;
2232 
2233 	kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);
2234 	unregister_fprobe(&kmulti_link->fp);
2235 }
2236 
2237 static void bpf_kprobe_multi_link_dealloc(struct bpf_link *link)
2238 {
2239 	struct bpf_kprobe_multi_link *kmulti_link;
2240 
2241 	kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);
2242 	kvfree(kmulti_link->addrs);
2243 	kvfree(kmulti_link->cookies);
2244 	kfree(kmulti_link);
2245 }
2246 
2247 static const struct bpf_link_ops bpf_kprobe_multi_link_lops = {
2248 	.release = bpf_kprobe_multi_link_release,
2249 	.dealloc = bpf_kprobe_multi_link_dealloc,
2250 };
2251 
2252 static void bpf_kprobe_multi_cookie_swap(void *a, void *b, int size, const void *priv)
2253 {
2254 	const struct bpf_kprobe_multi_link *link = priv;
2255 	unsigned long *addr_a = a, *addr_b = b;
2256 	u64 *cookie_a, *cookie_b;
2257 	unsigned long tmp1;
2258 	u64 tmp2;
2259 
2260 	cookie_a = link->cookies + (addr_a - link->addrs);
2261 	cookie_b = link->cookies + (addr_b - link->addrs);
2262 
2263 	/* swap addr_a/addr_b and cookie_a/cookie_b values */
2264 	tmp1 = *addr_a; *addr_a = *addr_b; *addr_b = tmp1;
2265 	tmp2 = *cookie_a; *cookie_a = *cookie_b; *cookie_b = tmp2;
2266 }
2267 
2268 static int __bpf_kprobe_multi_cookie_cmp(const void *a, const void *b)
2269 {
2270 	const unsigned long *addr_a = a, *addr_b = b;
2271 
2272 	if (*addr_a == *addr_b)
2273 		return 0;
2274 	return *addr_a < *addr_b ? -1 : 1;
2275 }
2276 
2277 static int bpf_kprobe_multi_cookie_cmp(const void *a, const void *b, const void *priv)
2278 {
2279 	return __bpf_kprobe_multi_cookie_cmp(a, b);
2280 }
2281 
2282 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx)
2283 {
2284 	struct bpf_kprobe_multi_run_ctx *run_ctx;
2285 	struct bpf_kprobe_multi_link *link;
2286 	u64 *cookie, entry_ip;
2287 	unsigned long *addr;
2288 
2289 	if (WARN_ON_ONCE(!ctx))
2290 		return 0;
2291 	run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, run_ctx);
2292 	link = run_ctx->link;
2293 	if (!link->cookies)
2294 		return 0;
2295 	entry_ip = run_ctx->entry_ip;
2296 	addr = bsearch(&entry_ip, link->addrs, link->cnt, sizeof(entry_ip),
2297 		       __bpf_kprobe_multi_cookie_cmp);
2298 	if (!addr)
2299 		return 0;
2300 	cookie = link->cookies + (addr - link->addrs);
2301 	return *cookie;
2302 }
2303 
2304 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
2305 {
2306 	struct bpf_kprobe_multi_run_ctx *run_ctx;
2307 
2308 	run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, run_ctx);
2309 	return run_ctx->entry_ip;
2310 }
2311 
2312 static int
2313 kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link,
2314 			   unsigned long entry_ip, struct pt_regs *regs)
2315 {
2316 	struct bpf_kprobe_multi_run_ctx run_ctx = {
2317 		.link = link,
2318 		.entry_ip = entry_ip,
2319 	};
2320 	struct bpf_run_ctx *old_run_ctx;
2321 	int err;
2322 
2323 	if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) {
2324 		err = 0;
2325 		goto out;
2326 	}
2327 
2328 	migrate_disable();
2329 	rcu_read_lock();
2330 	old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx);
2331 	err = bpf_prog_run(link->link.prog, regs);
2332 	bpf_reset_run_ctx(old_run_ctx);
2333 	rcu_read_unlock();
2334 	migrate_enable();
2335 
2336  out:
2337 	__this_cpu_dec(bpf_prog_active);
2338 	return err;
2339 }
2340 
2341 static void
2342 kprobe_multi_link_handler(struct fprobe *fp, unsigned long entry_ip,
2343 			  struct pt_regs *regs)
2344 {
2345 	struct bpf_kprobe_multi_link *link;
2346 
2347 	link = container_of(fp, struct bpf_kprobe_multi_link, fp);
2348 	kprobe_multi_link_prog_run(link, entry_ip, regs);
2349 }
2350 
2351 static int
2352 kprobe_multi_resolve_syms(const void __user *usyms, u32 cnt,
2353 			  unsigned long *addrs)
2354 {
2355 	unsigned long addr, size;
2356 	const char __user **syms;
2357 	int err = -ENOMEM;
2358 	unsigned int i;
2359 	char *func;
2360 
2361 	size = cnt * sizeof(*syms);
2362 	syms = kvzalloc(size, GFP_KERNEL);
2363 	if (!syms)
2364 		return -ENOMEM;
2365 
2366 	func = kmalloc(KSYM_NAME_LEN, GFP_KERNEL);
2367 	if (!func)
2368 		goto error;
2369 
2370 	if (copy_from_user(syms, usyms, size)) {
2371 		err = -EFAULT;
2372 		goto error;
2373 	}
2374 
2375 	for (i = 0; i < cnt; i++) {
2376 		err = strncpy_from_user(func, syms[i], KSYM_NAME_LEN);
2377 		if (err == KSYM_NAME_LEN)
2378 			err = -E2BIG;
2379 		if (err < 0)
2380 			goto error;
2381 		err = -EINVAL;
2382 		addr = kallsyms_lookup_name(func);
2383 		if (!addr)
2384 			goto error;
2385 		if (!kallsyms_lookup_size_offset(addr, &size, NULL))
2386 			goto error;
2387 		addr = ftrace_location_range(addr, addr + size - 1);
2388 		if (!addr)
2389 			goto error;
2390 		addrs[i] = addr;
2391 	}
2392 
2393 	err = 0;
2394 error:
2395 	kvfree(syms);
2396 	kfree(func);
2397 	return err;
2398 }
2399 
2400 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
2401 {
2402 	struct bpf_kprobe_multi_link *link = NULL;
2403 	struct bpf_link_primer link_primer;
2404 	void __user *ucookies;
2405 	unsigned long *addrs;
2406 	u32 flags, cnt, size;
2407 	void __user *uaddrs;
2408 	u64 *cookies = NULL;
2409 	void __user *usyms;
2410 	int err;
2411 
2412 	/* no support for 32bit archs yet */
2413 	if (sizeof(u64) != sizeof(void *))
2414 		return -EOPNOTSUPP;
2415 
2416 	if (prog->expected_attach_type != BPF_TRACE_KPROBE_MULTI)
2417 		return -EINVAL;
2418 
2419 	flags = attr->link_create.kprobe_multi.flags;
2420 	if (flags & ~BPF_F_KPROBE_MULTI_RETURN)
2421 		return -EINVAL;
2422 
2423 	uaddrs = u64_to_user_ptr(attr->link_create.kprobe_multi.addrs);
2424 	usyms = u64_to_user_ptr(attr->link_create.kprobe_multi.syms);
2425 	if (!!uaddrs == !!usyms)
2426 		return -EINVAL;
2427 
2428 	cnt = attr->link_create.kprobe_multi.cnt;
2429 	if (!cnt)
2430 		return -EINVAL;
2431 
2432 	size = cnt * sizeof(*addrs);
2433 	addrs = kvmalloc(size, GFP_KERNEL);
2434 	if (!addrs)
2435 		return -ENOMEM;
2436 
2437 	if (uaddrs) {
2438 		if (copy_from_user(addrs, uaddrs, size)) {
2439 			err = -EFAULT;
2440 			goto error;
2441 		}
2442 	} else {
2443 		err = kprobe_multi_resolve_syms(usyms, cnt, addrs);
2444 		if (err)
2445 			goto error;
2446 	}
2447 
2448 	ucookies = u64_to_user_ptr(attr->link_create.kprobe_multi.cookies);
2449 	if (ucookies) {
2450 		cookies = kvmalloc(size, GFP_KERNEL);
2451 		if (!cookies) {
2452 			err = -ENOMEM;
2453 			goto error;
2454 		}
2455 		if (copy_from_user(cookies, ucookies, size)) {
2456 			err = -EFAULT;
2457 			goto error;
2458 		}
2459 	}
2460 
2461 	link = kzalloc(sizeof(*link), GFP_KERNEL);
2462 	if (!link) {
2463 		err = -ENOMEM;
2464 		goto error;
2465 	}
2466 
2467 	bpf_link_init(&link->link, BPF_LINK_TYPE_KPROBE_MULTI,
2468 		      &bpf_kprobe_multi_link_lops, prog);
2469 
2470 	err = bpf_link_prime(&link->link, &link_primer);
2471 	if (err)
2472 		goto error;
2473 
2474 	if (flags & BPF_F_KPROBE_MULTI_RETURN)
2475 		link->fp.exit_handler = kprobe_multi_link_handler;
2476 	else
2477 		link->fp.entry_handler = kprobe_multi_link_handler;
2478 
2479 	link->addrs = addrs;
2480 	link->cookies = cookies;
2481 	link->cnt = cnt;
2482 
2483 	if (cookies) {
2484 		/*
2485 		 * Sorting addresses will trigger sorting cookies as well
2486 		 * (check bpf_kprobe_multi_cookie_swap). This way we can
2487 		 * find cookie based on the address in bpf_get_attach_cookie
2488 		 * helper.
2489 		 */
2490 		sort_r(addrs, cnt, sizeof(*addrs),
2491 		       bpf_kprobe_multi_cookie_cmp,
2492 		       bpf_kprobe_multi_cookie_swap,
2493 		       link);
2494 	}
2495 
2496 	err = register_fprobe_ips(&link->fp, addrs, cnt);
2497 	if (err) {
2498 		bpf_link_cleanup(&link_primer);
2499 		return err;
2500 	}
2501 
2502 	return bpf_link_settle(&link_primer);
2503 
2504 error:
2505 	kfree(link);
2506 	kvfree(addrs);
2507 	kvfree(cookies);
2508 	return err;
2509 }
2510 #else /* !CONFIG_FPROBE */
2511 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
2512 {
2513 	return -EOPNOTSUPP;
2514 }
2515 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx)
2516 {
2517 	return 0;
2518 }
2519 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
2520 {
2521 	return 0;
2522 }
2523 #endif
2524