xref: /openbmc/linux/kernel/trace/bpf_trace.c (revision b1c3d2be)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2011-2015 PLUMgrid, http://plumgrid.com
3  * Copyright (c) 2016 Facebook
4  */
5 #include <linux/kernel.h>
6 #include <linux/types.h>
7 #include <linux/slab.h>
8 #include <linux/bpf.h>
9 #include <linux/bpf_verifier.h>
10 #include <linux/bpf_perf_event.h>
11 #include <linux/btf.h>
12 #include <linux/filter.h>
13 #include <linux/uaccess.h>
14 #include <linux/ctype.h>
15 #include <linux/kprobes.h>
16 #include <linux/spinlock.h>
17 #include <linux/syscalls.h>
18 #include <linux/error-injection.h>
19 #include <linux/btf_ids.h>
20 #include <linux/bpf_lsm.h>
21 #include <linux/fprobe.h>
22 #include <linux/bsearch.h>
23 #include <linux/sort.h>
24 #include <linux/key.h>
25 #include <linux/verification.h>
26 
27 #include <net/bpf_sk_storage.h>
28 
29 #include <uapi/linux/bpf.h>
30 #include <uapi/linux/btf.h>
31 
32 #include <asm/tlb.h>
33 
34 #include "trace_probe.h"
35 #include "trace.h"
36 
37 #define CREATE_TRACE_POINTS
38 #include "bpf_trace.h"
39 
40 #define bpf_event_rcu_dereference(p)					\
41 	rcu_dereference_protected(p, lockdep_is_held(&bpf_event_mutex))
42 
43 #ifdef CONFIG_MODULES
44 struct bpf_trace_module {
45 	struct module *module;
46 	struct list_head list;
47 };
48 
49 static LIST_HEAD(bpf_trace_modules);
50 static DEFINE_MUTEX(bpf_module_mutex);
51 
52 static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name)
53 {
54 	struct bpf_raw_event_map *btp, *ret = NULL;
55 	struct bpf_trace_module *btm;
56 	unsigned int i;
57 
58 	mutex_lock(&bpf_module_mutex);
59 	list_for_each_entry(btm, &bpf_trace_modules, list) {
60 		for (i = 0; i < btm->module->num_bpf_raw_events; ++i) {
61 			btp = &btm->module->bpf_raw_events[i];
62 			if (!strcmp(btp->tp->name, name)) {
63 				if (try_module_get(btm->module))
64 					ret = btp;
65 				goto out;
66 			}
67 		}
68 	}
69 out:
70 	mutex_unlock(&bpf_module_mutex);
71 	return ret;
72 }
73 #else
74 static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name)
75 {
76 	return NULL;
77 }
78 #endif /* CONFIG_MODULES */
79 
80 u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
81 u64 bpf_get_stack(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
82 
83 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size,
84 				  u64 flags, const struct btf **btf,
85 				  s32 *btf_id);
86 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx);
87 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx);
88 
89 /**
90  * trace_call_bpf - invoke BPF program
91  * @call: tracepoint event
92  * @ctx: opaque context pointer
93  *
94  * kprobe handlers execute BPF programs via this helper.
95  * Can be used from static tracepoints in the future.
96  *
97  * Return: BPF programs always return an integer which is interpreted by
98  * kprobe handler as:
99  * 0 - return from kprobe (event is filtered out)
100  * 1 - store kprobe event into ring buffer
101  * Other values are reserved and currently alias to 1
102  */
103 unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx)
104 {
105 	unsigned int ret;
106 
107 	cant_sleep();
108 
109 	if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) {
110 		/*
111 		 * since some bpf program is already running on this cpu,
112 		 * don't call into another bpf program (same or different)
113 		 * and don't send kprobe event into ring-buffer,
114 		 * so return zero here
115 		 */
116 		ret = 0;
117 		goto out;
118 	}
119 
120 	/*
121 	 * Instead of moving rcu_read_lock/rcu_dereference/rcu_read_unlock
122 	 * to all call sites, we did a bpf_prog_array_valid() there to check
123 	 * whether call->prog_array is empty or not, which is
124 	 * a heuristic to speed up execution.
125 	 *
126 	 * If bpf_prog_array_valid() fetched prog_array was
127 	 * non-NULL, we go into trace_call_bpf() and do the actual
128 	 * proper rcu_dereference() under RCU lock.
129 	 * If it turns out that prog_array is NULL then, we bail out.
130 	 * For the opposite, if the bpf_prog_array_valid() fetched pointer
131 	 * was NULL, you'll skip the prog_array with the risk of missing
132 	 * out of events when it was updated in between this and the
133 	 * rcu_dereference() which is accepted risk.
134 	 */
135 	rcu_read_lock();
136 	ret = bpf_prog_run_array(rcu_dereference(call->prog_array),
137 				 ctx, bpf_prog_run);
138 	rcu_read_unlock();
139 
140  out:
141 	__this_cpu_dec(bpf_prog_active);
142 
143 	return ret;
144 }
145 
146 #ifdef CONFIG_BPF_KPROBE_OVERRIDE
147 BPF_CALL_2(bpf_override_return, struct pt_regs *, regs, unsigned long, rc)
148 {
149 	regs_set_return_value(regs, rc);
150 	override_function_with_return(regs);
151 	return 0;
152 }
153 
154 static const struct bpf_func_proto bpf_override_return_proto = {
155 	.func		= bpf_override_return,
156 	.gpl_only	= true,
157 	.ret_type	= RET_INTEGER,
158 	.arg1_type	= ARG_PTR_TO_CTX,
159 	.arg2_type	= ARG_ANYTHING,
160 };
161 #endif
162 
163 static __always_inline int
164 bpf_probe_read_user_common(void *dst, u32 size, const void __user *unsafe_ptr)
165 {
166 	int ret;
167 
168 	ret = copy_from_user_nofault(dst, unsafe_ptr, size);
169 	if (unlikely(ret < 0))
170 		memset(dst, 0, size);
171 	return ret;
172 }
173 
174 BPF_CALL_3(bpf_probe_read_user, void *, dst, u32, size,
175 	   const void __user *, unsafe_ptr)
176 {
177 	return bpf_probe_read_user_common(dst, size, unsafe_ptr);
178 }
179 
180 const struct bpf_func_proto bpf_probe_read_user_proto = {
181 	.func		= bpf_probe_read_user,
182 	.gpl_only	= true,
183 	.ret_type	= RET_INTEGER,
184 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
185 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
186 	.arg3_type	= ARG_ANYTHING,
187 };
188 
189 static __always_inline int
190 bpf_probe_read_user_str_common(void *dst, u32 size,
191 			       const void __user *unsafe_ptr)
192 {
193 	int ret;
194 
195 	/*
196 	 * NB: We rely on strncpy_from_user() not copying junk past the NUL
197 	 * terminator into `dst`.
198 	 *
199 	 * strncpy_from_user() does long-sized strides in the fast path. If the
200 	 * strncpy does not mask out the bytes after the NUL in `unsafe_ptr`,
201 	 * then there could be junk after the NUL in `dst`. If user takes `dst`
202 	 * and keys a hash map with it, then semantically identical strings can
203 	 * occupy multiple entries in the map.
204 	 */
205 	ret = strncpy_from_user_nofault(dst, unsafe_ptr, size);
206 	if (unlikely(ret < 0))
207 		memset(dst, 0, size);
208 	return ret;
209 }
210 
211 BPF_CALL_3(bpf_probe_read_user_str, void *, dst, u32, size,
212 	   const void __user *, unsafe_ptr)
213 {
214 	return bpf_probe_read_user_str_common(dst, size, unsafe_ptr);
215 }
216 
217 const struct bpf_func_proto bpf_probe_read_user_str_proto = {
218 	.func		= bpf_probe_read_user_str,
219 	.gpl_only	= true,
220 	.ret_type	= RET_INTEGER,
221 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
222 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
223 	.arg3_type	= ARG_ANYTHING,
224 };
225 
226 static __always_inline int
227 bpf_probe_read_kernel_common(void *dst, u32 size, const void *unsafe_ptr)
228 {
229 	int ret;
230 
231 	ret = copy_from_kernel_nofault(dst, unsafe_ptr, size);
232 	if (unlikely(ret < 0))
233 		memset(dst, 0, size);
234 	return ret;
235 }
236 
237 BPF_CALL_3(bpf_probe_read_kernel, void *, dst, u32, size,
238 	   const void *, unsafe_ptr)
239 {
240 	return bpf_probe_read_kernel_common(dst, size, unsafe_ptr);
241 }
242 
243 const struct bpf_func_proto bpf_probe_read_kernel_proto = {
244 	.func		= bpf_probe_read_kernel,
245 	.gpl_only	= true,
246 	.ret_type	= RET_INTEGER,
247 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
248 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
249 	.arg3_type	= ARG_ANYTHING,
250 };
251 
252 static __always_inline int
253 bpf_probe_read_kernel_str_common(void *dst, u32 size, const void *unsafe_ptr)
254 {
255 	int ret;
256 
257 	/*
258 	 * The strncpy_from_kernel_nofault() call will likely not fill the
259 	 * entire buffer, but that's okay in this circumstance as we're probing
260 	 * arbitrary memory anyway similar to bpf_probe_read_*() and might
261 	 * as well probe the stack. Thus, memory is explicitly cleared
262 	 * only in error case, so that improper users ignoring return
263 	 * code altogether don't copy garbage; otherwise length of string
264 	 * is returned that can be used for bpf_perf_event_output() et al.
265 	 */
266 	ret = strncpy_from_kernel_nofault(dst, unsafe_ptr, size);
267 	if (unlikely(ret < 0))
268 		memset(dst, 0, size);
269 	return ret;
270 }
271 
272 BPF_CALL_3(bpf_probe_read_kernel_str, void *, dst, u32, size,
273 	   const void *, unsafe_ptr)
274 {
275 	return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr);
276 }
277 
278 const struct bpf_func_proto bpf_probe_read_kernel_str_proto = {
279 	.func		= bpf_probe_read_kernel_str,
280 	.gpl_only	= true,
281 	.ret_type	= RET_INTEGER,
282 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
283 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
284 	.arg3_type	= ARG_ANYTHING,
285 };
286 
287 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
288 BPF_CALL_3(bpf_probe_read_compat, void *, dst, u32, size,
289 	   const void *, unsafe_ptr)
290 {
291 	if ((unsigned long)unsafe_ptr < TASK_SIZE) {
292 		return bpf_probe_read_user_common(dst, size,
293 				(__force void __user *)unsafe_ptr);
294 	}
295 	return bpf_probe_read_kernel_common(dst, size, unsafe_ptr);
296 }
297 
298 static const struct bpf_func_proto bpf_probe_read_compat_proto = {
299 	.func		= bpf_probe_read_compat,
300 	.gpl_only	= true,
301 	.ret_type	= RET_INTEGER,
302 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
303 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
304 	.arg3_type	= ARG_ANYTHING,
305 };
306 
307 BPF_CALL_3(bpf_probe_read_compat_str, void *, dst, u32, size,
308 	   const void *, unsafe_ptr)
309 {
310 	if ((unsigned long)unsafe_ptr < TASK_SIZE) {
311 		return bpf_probe_read_user_str_common(dst, size,
312 				(__force void __user *)unsafe_ptr);
313 	}
314 	return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr);
315 }
316 
317 static const struct bpf_func_proto bpf_probe_read_compat_str_proto = {
318 	.func		= bpf_probe_read_compat_str,
319 	.gpl_only	= true,
320 	.ret_type	= RET_INTEGER,
321 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
322 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
323 	.arg3_type	= ARG_ANYTHING,
324 };
325 #endif /* CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE */
326 
327 BPF_CALL_3(bpf_probe_write_user, void __user *, unsafe_ptr, const void *, src,
328 	   u32, size)
329 {
330 	/*
331 	 * Ensure we're in user context which is safe for the helper to
332 	 * run. This helper has no business in a kthread.
333 	 *
334 	 * access_ok() should prevent writing to non-user memory, but in
335 	 * some situations (nommu, temporary switch, etc) access_ok() does
336 	 * not provide enough validation, hence the check on KERNEL_DS.
337 	 *
338 	 * nmi_uaccess_okay() ensures the probe is not run in an interim
339 	 * state, when the task or mm are switched. This is specifically
340 	 * required to prevent the use of temporary mm.
341 	 */
342 
343 	if (unlikely(in_interrupt() ||
344 		     current->flags & (PF_KTHREAD | PF_EXITING)))
345 		return -EPERM;
346 	if (unlikely(!nmi_uaccess_okay()))
347 		return -EPERM;
348 
349 	return copy_to_user_nofault(unsafe_ptr, src, size);
350 }
351 
352 static const struct bpf_func_proto bpf_probe_write_user_proto = {
353 	.func		= bpf_probe_write_user,
354 	.gpl_only	= true,
355 	.ret_type	= RET_INTEGER,
356 	.arg1_type	= ARG_ANYTHING,
357 	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
358 	.arg3_type	= ARG_CONST_SIZE,
359 };
360 
361 static const struct bpf_func_proto *bpf_get_probe_write_proto(void)
362 {
363 	if (!capable(CAP_SYS_ADMIN))
364 		return NULL;
365 
366 	pr_warn_ratelimited("%s[%d] is installing a program with bpf_probe_write_user helper that may corrupt user memory!",
367 			    current->comm, task_pid_nr(current));
368 
369 	return &bpf_probe_write_user_proto;
370 }
371 
372 static DEFINE_RAW_SPINLOCK(trace_printk_lock);
373 
374 #define MAX_TRACE_PRINTK_VARARGS	3
375 #define BPF_TRACE_PRINTK_SIZE		1024
376 
377 BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1,
378 	   u64, arg2, u64, arg3)
379 {
380 	u64 args[MAX_TRACE_PRINTK_VARARGS] = { arg1, arg2, arg3 };
381 	u32 *bin_args;
382 	static char buf[BPF_TRACE_PRINTK_SIZE];
383 	unsigned long flags;
384 	int ret;
385 
386 	ret = bpf_bprintf_prepare(fmt, fmt_size, args, &bin_args,
387 				  MAX_TRACE_PRINTK_VARARGS);
388 	if (ret < 0)
389 		return ret;
390 
391 	raw_spin_lock_irqsave(&trace_printk_lock, flags);
392 	ret = bstr_printf(buf, sizeof(buf), fmt, bin_args);
393 
394 	trace_bpf_trace_printk(buf);
395 	raw_spin_unlock_irqrestore(&trace_printk_lock, flags);
396 
397 	bpf_bprintf_cleanup();
398 
399 	return ret;
400 }
401 
402 static const struct bpf_func_proto bpf_trace_printk_proto = {
403 	.func		= bpf_trace_printk,
404 	.gpl_only	= true,
405 	.ret_type	= RET_INTEGER,
406 	.arg1_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
407 	.arg2_type	= ARG_CONST_SIZE,
408 };
409 
410 static void __set_printk_clr_event(void)
411 {
412 	/*
413 	 * This program might be calling bpf_trace_printk,
414 	 * so enable the associated bpf_trace/bpf_trace_printk event.
415 	 * Repeat this each time as it is possible a user has
416 	 * disabled bpf_trace_printk events.  By loading a program
417 	 * calling bpf_trace_printk() however the user has expressed
418 	 * the intent to see such events.
419 	 */
420 	if (trace_set_clr_event("bpf_trace", "bpf_trace_printk", 1))
421 		pr_warn_ratelimited("could not enable bpf_trace_printk events");
422 }
423 
424 const struct bpf_func_proto *bpf_get_trace_printk_proto(void)
425 {
426 	__set_printk_clr_event();
427 	return &bpf_trace_printk_proto;
428 }
429 
430 BPF_CALL_4(bpf_trace_vprintk, char *, fmt, u32, fmt_size, const void *, data,
431 	   u32, data_len)
432 {
433 	static char buf[BPF_TRACE_PRINTK_SIZE];
434 	unsigned long flags;
435 	int ret, num_args;
436 	u32 *bin_args;
437 
438 	if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 ||
439 	    (data_len && !data))
440 		return -EINVAL;
441 	num_args = data_len / 8;
442 
443 	ret = bpf_bprintf_prepare(fmt, fmt_size, data, &bin_args, num_args);
444 	if (ret < 0)
445 		return ret;
446 
447 	raw_spin_lock_irqsave(&trace_printk_lock, flags);
448 	ret = bstr_printf(buf, sizeof(buf), fmt, bin_args);
449 
450 	trace_bpf_trace_printk(buf);
451 	raw_spin_unlock_irqrestore(&trace_printk_lock, flags);
452 
453 	bpf_bprintf_cleanup();
454 
455 	return ret;
456 }
457 
458 static const struct bpf_func_proto bpf_trace_vprintk_proto = {
459 	.func		= bpf_trace_vprintk,
460 	.gpl_only	= true,
461 	.ret_type	= RET_INTEGER,
462 	.arg1_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
463 	.arg2_type	= ARG_CONST_SIZE,
464 	.arg3_type	= ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY,
465 	.arg4_type	= ARG_CONST_SIZE_OR_ZERO,
466 };
467 
468 const struct bpf_func_proto *bpf_get_trace_vprintk_proto(void)
469 {
470 	__set_printk_clr_event();
471 	return &bpf_trace_vprintk_proto;
472 }
473 
474 BPF_CALL_5(bpf_seq_printf, struct seq_file *, m, char *, fmt, u32, fmt_size,
475 	   const void *, data, u32, data_len)
476 {
477 	int err, num_args;
478 	u32 *bin_args;
479 
480 	if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 ||
481 	    (data_len && !data))
482 		return -EINVAL;
483 	num_args = data_len / 8;
484 
485 	err = bpf_bprintf_prepare(fmt, fmt_size, data, &bin_args, num_args);
486 	if (err < 0)
487 		return err;
488 
489 	seq_bprintf(m, fmt, bin_args);
490 
491 	bpf_bprintf_cleanup();
492 
493 	return seq_has_overflowed(m) ? -EOVERFLOW : 0;
494 }
495 
496 BTF_ID_LIST_SINGLE(btf_seq_file_ids, struct, seq_file)
497 
498 static const struct bpf_func_proto bpf_seq_printf_proto = {
499 	.func		= bpf_seq_printf,
500 	.gpl_only	= true,
501 	.ret_type	= RET_INTEGER,
502 	.arg1_type	= ARG_PTR_TO_BTF_ID,
503 	.arg1_btf_id	= &btf_seq_file_ids[0],
504 	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
505 	.arg3_type	= ARG_CONST_SIZE,
506 	.arg4_type      = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY,
507 	.arg5_type      = ARG_CONST_SIZE_OR_ZERO,
508 };
509 
510 BPF_CALL_3(bpf_seq_write, struct seq_file *, m, const void *, data, u32, len)
511 {
512 	return seq_write(m, data, len) ? -EOVERFLOW : 0;
513 }
514 
515 static const struct bpf_func_proto bpf_seq_write_proto = {
516 	.func		= bpf_seq_write,
517 	.gpl_only	= true,
518 	.ret_type	= RET_INTEGER,
519 	.arg1_type	= ARG_PTR_TO_BTF_ID,
520 	.arg1_btf_id	= &btf_seq_file_ids[0],
521 	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
522 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
523 };
524 
525 BPF_CALL_4(bpf_seq_printf_btf, struct seq_file *, m, struct btf_ptr *, ptr,
526 	   u32, btf_ptr_size, u64, flags)
527 {
528 	const struct btf *btf;
529 	s32 btf_id;
530 	int ret;
531 
532 	ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id);
533 	if (ret)
534 		return ret;
535 
536 	return btf_type_seq_show_flags(btf, btf_id, ptr->ptr, m, flags);
537 }
538 
539 static const struct bpf_func_proto bpf_seq_printf_btf_proto = {
540 	.func		= bpf_seq_printf_btf,
541 	.gpl_only	= true,
542 	.ret_type	= RET_INTEGER,
543 	.arg1_type	= ARG_PTR_TO_BTF_ID,
544 	.arg1_btf_id	= &btf_seq_file_ids[0],
545 	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
546 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
547 	.arg4_type	= ARG_ANYTHING,
548 };
549 
550 static __always_inline int
551 get_map_perf_counter(struct bpf_map *map, u64 flags,
552 		     u64 *value, u64 *enabled, u64 *running)
553 {
554 	struct bpf_array *array = container_of(map, struct bpf_array, map);
555 	unsigned int cpu = smp_processor_id();
556 	u64 index = flags & BPF_F_INDEX_MASK;
557 	struct bpf_event_entry *ee;
558 
559 	if (unlikely(flags & ~(BPF_F_INDEX_MASK)))
560 		return -EINVAL;
561 	if (index == BPF_F_CURRENT_CPU)
562 		index = cpu;
563 	if (unlikely(index >= array->map.max_entries))
564 		return -E2BIG;
565 
566 	ee = READ_ONCE(array->ptrs[index]);
567 	if (!ee)
568 		return -ENOENT;
569 
570 	return perf_event_read_local(ee->event, value, enabled, running);
571 }
572 
573 BPF_CALL_2(bpf_perf_event_read, struct bpf_map *, map, u64, flags)
574 {
575 	u64 value = 0;
576 	int err;
577 
578 	err = get_map_perf_counter(map, flags, &value, NULL, NULL);
579 	/*
580 	 * this api is ugly since we miss [-22..-2] range of valid
581 	 * counter values, but that's uapi
582 	 */
583 	if (err)
584 		return err;
585 	return value;
586 }
587 
588 static const struct bpf_func_proto bpf_perf_event_read_proto = {
589 	.func		= bpf_perf_event_read,
590 	.gpl_only	= true,
591 	.ret_type	= RET_INTEGER,
592 	.arg1_type	= ARG_CONST_MAP_PTR,
593 	.arg2_type	= ARG_ANYTHING,
594 };
595 
596 BPF_CALL_4(bpf_perf_event_read_value, struct bpf_map *, map, u64, flags,
597 	   struct bpf_perf_event_value *, buf, u32, size)
598 {
599 	int err = -EINVAL;
600 
601 	if (unlikely(size != sizeof(struct bpf_perf_event_value)))
602 		goto clear;
603 	err = get_map_perf_counter(map, flags, &buf->counter, &buf->enabled,
604 				   &buf->running);
605 	if (unlikely(err))
606 		goto clear;
607 	return 0;
608 clear:
609 	memset(buf, 0, size);
610 	return err;
611 }
612 
613 static const struct bpf_func_proto bpf_perf_event_read_value_proto = {
614 	.func		= bpf_perf_event_read_value,
615 	.gpl_only	= true,
616 	.ret_type	= RET_INTEGER,
617 	.arg1_type	= ARG_CONST_MAP_PTR,
618 	.arg2_type	= ARG_ANYTHING,
619 	.arg3_type	= ARG_PTR_TO_UNINIT_MEM,
620 	.arg4_type	= ARG_CONST_SIZE,
621 };
622 
623 static __always_inline u64
624 __bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map,
625 			u64 flags, struct perf_sample_data *sd)
626 {
627 	struct bpf_array *array = container_of(map, struct bpf_array, map);
628 	unsigned int cpu = smp_processor_id();
629 	u64 index = flags & BPF_F_INDEX_MASK;
630 	struct bpf_event_entry *ee;
631 	struct perf_event *event;
632 
633 	if (index == BPF_F_CURRENT_CPU)
634 		index = cpu;
635 	if (unlikely(index >= array->map.max_entries))
636 		return -E2BIG;
637 
638 	ee = READ_ONCE(array->ptrs[index]);
639 	if (!ee)
640 		return -ENOENT;
641 
642 	event = ee->event;
643 	if (unlikely(event->attr.type != PERF_TYPE_SOFTWARE ||
644 		     event->attr.config != PERF_COUNT_SW_BPF_OUTPUT))
645 		return -EINVAL;
646 
647 	if (unlikely(event->oncpu != cpu))
648 		return -EOPNOTSUPP;
649 
650 	return perf_event_output(event, sd, regs);
651 }
652 
653 /*
654  * Support executing tracepoints in normal, irq, and nmi context that each call
655  * bpf_perf_event_output
656  */
657 struct bpf_trace_sample_data {
658 	struct perf_sample_data sds[3];
659 };
660 
661 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_trace_sds);
662 static DEFINE_PER_CPU(int, bpf_trace_nest_level);
663 BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map,
664 	   u64, flags, void *, data, u64, size)
665 {
666 	struct bpf_trace_sample_data *sds = this_cpu_ptr(&bpf_trace_sds);
667 	int nest_level = this_cpu_inc_return(bpf_trace_nest_level);
668 	struct perf_raw_record raw = {
669 		.frag = {
670 			.size = size,
671 			.data = data,
672 		},
673 	};
674 	struct perf_sample_data *sd;
675 	int err;
676 
677 	if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(sds->sds))) {
678 		err = -EBUSY;
679 		goto out;
680 	}
681 
682 	sd = &sds->sds[nest_level - 1];
683 
684 	if (unlikely(flags & ~(BPF_F_INDEX_MASK))) {
685 		err = -EINVAL;
686 		goto out;
687 	}
688 
689 	perf_sample_data_init(sd, 0, 0);
690 	sd->raw = &raw;
691 	sd->sample_flags |= PERF_SAMPLE_RAW;
692 
693 	err = __bpf_perf_event_output(regs, map, flags, sd);
694 
695 out:
696 	this_cpu_dec(bpf_trace_nest_level);
697 	return err;
698 }
699 
700 static const struct bpf_func_proto bpf_perf_event_output_proto = {
701 	.func		= bpf_perf_event_output,
702 	.gpl_only	= true,
703 	.ret_type	= RET_INTEGER,
704 	.arg1_type	= ARG_PTR_TO_CTX,
705 	.arg2_type	= ARG_CONST_MAP_PTR,
706 	.arg3_type	= ARG_ANYTHING,
707 	.arg4_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
708 	.arg5_type	= ARG_CONST_SIZE_OR_ZERO,
709 };
710 
711 static DEFINE_PER_CPU(int, bpf_event_output_nest_level);
712 struct bpf_nested_pt_regs {
713 	struct pt_regs regs[3];
714 };
715 static DEFINE_PER_CPU(struct bpf_nested_pt_regs, bpf_pt_regs);
716 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_misc_sds);
717 
718 u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
719 		     void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy)
720 {
721 	int nest_level = this_cpu_inc_return(bpf_event_output_nest_level);
722 	struct perf_raw_frag frag = {
723 		.copy		= ctx_copy,
724 		.size		= ctx_size,
725 		.data		= ctx,
726 	};
727 	struct perf_raw_record raw = {
728 		.frag = {
729 			{
730 				.next	= ctx_size ? &frag : NULL,
731 			},
732 			.size	= meta_size,
733 			.data	= meta,
734 		},
735 	};
736 	struct perf_sample_data *sd;
737 	struct pt_regs *regs;
738 	u64 ret;
739 
740 	if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(bpf_misc_sds.sds))) {
741 		ret = -EBUSY;
742 		goto out;
743 	}
744 	sd = this_cpu_ptr(&bpf_misc_sds.sds[nest_level - 1]);
745 	regs = this_cpu_ptr(&bpf_pt_regs.regs[nest_level - 1]);
746 
747 	perf_fetch_caller_regs(regs);
748 	perf_sample_data_init(sd, 0, 0);
749 	sd->raw = &raw;
750 	sd->sample_flags |= PERF_SAMPLE_RAW;
751 
752 	ret = __bpf_perf_event_output(regs, map, flags, sd);
753 out:
754 	this_cpu_dec(bpf_event_output_nest_level);
755 	return ret;
756 }
757 
758 BPF_CALL_0(bpf_get_current_task)
759 {
760 	return (long) current;
761 }
762 
763 const struct bpf_func_proto bpf_get_current_task_proto = {
764 	.func		= bpf_get_current_task,
765 	.gpl_only	= true,
766 	.ret_type	= RET_INTEGER,
767 };
768 
769 BPF_CALL_0(bpf_get_current_task_btf)
770 {
771 	return (unsigned long) current;
772 }
773 
774 const struct bpf_func_proto bpf_get_current_task_btf_proto = {
775 	.func		= bpf_get_current_task_btf,
776 	.gpl_only	= true,
777 	.ret_type	= RET_PTR_TO_BTF_ID_TRUSTED,
778 	.ret_btf_id	= &btf_tracing_ids[BTF_TRACING_TYPE_TASK],
779 };
780 
781 BPF_CALL_1(bpf_task_pt_regs, struct task_struct *, task)
782 {
783 	return (unsigned long) task_pt_regs(task);
784 }
785 
786 BTF_ID_LIST(bpf_task_pt_regs_ids)
787 BTF_ID(struct, pt_regs)
788 
789 const struct bpf_func_proto bpf_task_pt_regs_proto = {
790 	.func		= bpf_task_pt_regs,
791 	.gpl_only	= true,
792 	.arg1_type	= ARG_PTR_TO_BTF_ID,
793 	.arg1_btf_id	= &btf_tracing_ids[BTF_TRACING_TYPE_TASK],
794 	.ret_type	= RET_PTR_TO_BTF_ID,
795 	.ret_btf_id	= &bpf_task_pt_regs_ids[0],
796 };
797 
798 BPF_CALL_2(bpf_current_task_under_cgroup, struct bpf_map *, map, u32, idx)
799 {
800 	struct bpf_array *array = container_of(map, struct bpf_array, map);
801 	struct cgroup *cgrp;
802 
803 	if (unlikely(idx >= array->map.max_entries))
804 		return -E2BIG;
805 
806 	cgrp = READ_ONCE(array->ptrs[idx]);
807 	if (unlikely(!cgrp))
808 		return -EAGAIN;
809 
810 	return task_under_cgroup_hierarchy(current, cgrp);
811 }
812 
813 static const struct bpf_func_proto bpf_current_task_under_cgroup_proto = {
814 	.func           = bpf_current_task_under_cgroup,
815 	.gpl_only       = false,
816 	.ret_type       = RET_INTEGER,
817 	.arg1_type      = ARG_CONST_MAP_PTR,
818 	.arg2_type      = ARG_ANYTHING,
819 };
820 
821 struct send_signal_irq_work {
822 	struct irq_work irq_work;
823 	struct task_struct *task;
824 	u32 sig;
825 	enum pid_type type;
826 };
827 
828 static DEFINE_PER_CPU(struct send_signal_irq_work, send_signal_work);
829 
830 static void do_bpf_send_signal(struct irq_work *entry)
831 {
832 	struct send_signal_irq_work *work;
833 
834 	work = container_of(entry, struct send_signal_irq_work, irq_work);
835 	group_send_sig_info(work->sig, SEND_SIG_PRIV, work->task, work->type);
836 }
837 
838 static int bpf_send_signal_common(u32 sig, enum pid_type type)
839 {
840 	struct send_signal_irq_work *work = NULL;
841 
842 	/* Similar to bpf_probe_write_user, task needs to be
843 	 * in a sound condition and kernel memory access be
844 	 * permitted in order to send signal to the current
845 	 * task.
846 	 */
847 	if (unlikely(current->flags & (PF_KTHREAD | PF_EXITING)))
848 		return -EPERM;
849 	if (unlikely(!nmi_uaccess_okay()))
850 		return -EPERM;
851 	/* Task should not be pid=1 to avoid kernel panic. */
852 	if (unlikely(is_global_init(current)))
853 		return -EPERM;
854 
855 	if (irqs_disabled()) {
856 		/* Do an early check on signal validity. Otherwise,
857 		 * the error is lost in deferred irq_work.
858 		 */
859 		if (unlikely(!valid_signal(sig)))
860 			return -EINVAL;
861 
862 		work = this_cpu_ptr(&send_signal_work);
863 		if (irq_work_is_busy(&work->irq_work))
864 			return -EBUSY;
865 
866 		/* Add the current task, which is the target of sending signal,
867 		 * to the irq_work. The current task may change when queued
868 		 * irq works get executed.
869 		 */
870 		work->task = current;
871 		work->sig = sig;
872 		work->type = type;
873 		irq_work_queue(&work->irq_work);
874 		return 0;
875 	}
876 
877 	return group_send_sig_info(sig, SEND_SIG_PRIV, current, type);
878 }
879 
880 BPF_CALL_1(bpf_send_signal, u32, sig)
881 {
882 	return bpf_send_signal_common(sig, PIDTYPE_TGID);
883 }
884 
885 static const struct bpf_func_proto bpf_send_signal_proto = {
886 	.func		= bpf_send_signal,
887 	.gpl_only	= false,
888 	.ret_type	= RET_INTEGER,
889 	.arg1_type	= ARG_ANYTHING,
890 };
891 
892 BPF_CALL_1(bpf_send_signal_thread, u32, sig)
893 {
894 	return bpf_send_signal_common(sig, PIDTYPE_PID);
895 }
896 
897 static const struct bpf_func_proto bpf_send_signal_thread_proto = {
898 	.func		= bpf_send_signal_thread,
899 	.gpl_only	= false,
900 	.ret_type	= RET_INTEGER,
901 	.arg1_type	= ARG_ANYTHING,
902 };
903 
904 BPF_CALL_3(bpf_d_path, struct path *, path, char *, buf, u32, sz)
905 {
906 	long len;
907 	char *p;
908 
909 	if (!sz)
910 		return 0;
911 
912 	p = d_path(path, buf, sz);
913 	if (IS_ERR(p)) {
914 		len = PTR_ERR(p);
915 	} else {
916 		len = buf + sz - p;
917 		memmove(buf, p, len);
918 	}
919 
920 	return len;
921 }
922 
923 BTF_SET_START(btf_allowlist_d_path)
924 #ifdef CONFIG_SECURITY
925 BTF_ID(func, security_file_permission)
926 BTF_ID(func, security_inode_getattr)
927 BTF_ID(func, security_file_open)
928 #endif
929 #ifdef CONFIG_SECURITY_PATH
930 BTF_ID(func, security_path_truncate)
931 #endif
932 BTF_ID(func, vfs_truncate)
933 BTF_ID(func, vfs_fallocate)
934 BTF_ID(func, dentry_open)
935 BTF_ID(func, vfs_getattr)
936 BTF_ID(func, filp_close)
937 BTF_SET_END(btf_allowlist_d_path)
938 
939 static bool bpf_d_path_allowed(const struct bpf_prog *prog)
940 {
941 	if (prog->type == BPF_PROG_TYPE_TRACING &&
942 	    prog->expected_attach_type == BPF_TRACE_ITER)
943 		return true;
944 
945 	if (prog->type == BPF_PROG_TYPE_LSM)
946 		return bpf_lsm_is_sleepable_hook(prog->aux->attach_btf_id);
947 
948 	return btf_id_set_contains(&btf_allowlist_d_path,
949 				   prog->aux->attach_btf_id);
950 }
951 
952 BTF_ID_LIST_SINGLE(bpf_d_path_btf_ids, struct, path)
953 
954 static const struct bpf_func_proto bpf_d_path_proto = {
955 	.func		= bpf_d_path,
956 	.gpl_only	= false,
957 	.ret_type	= RET_INTEGER,
958 	.arg1_type	= ARG_PTR_TO_BTF_ID,
959 	.arg1_btf_id	= &bpf_d_path_btf_ids[0],
960 	.arg2_type	= ARG_PTR_TO_MEM,
961 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
962 	.allowed	= bpf_d_path_allowed,
963 };
964 
965 #define BTF_F_ALL	(BTF_F_COMPACT  | BTF_F_NONAME | \
966 			 BTF_F_PTR_RAW | BTF_F_ZERO)
967 
968 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size,
969 				  u64 flags, const struct btf **btf,
970 				  s32 *btf_id)
971 {
972 	const struct btf_type *t;
973 
974 	if (unlikely(flags & ~(BTF_F_ALL)))
975 		return -EINVAL;
976 
977 	if (btf_ptr_size != sizeof(struct btf_ptr))
978 		return -EINVAL;
979 
980 	*btf = bpf_get_btf_vmlinux();
981 
982 	if (IS_ERR_OR_NULL(*btf))
983 		return IS_ERR(*btf) ? PTR_ERR(*btf) : -EINVAL;
984 
985 	if (ptr->type_id > 0)
986 		*btf_id = ptr->type_id;
987 	else
988 		return -EINVAL;
989 
990 	if (*btf_id > 0)
991 		t = btf_type_by_id(*btf, *btf_id);
992 	if (*btf_id <= 0 || !t)
993 		return -ENOENT;
994 
995 	return 0;
996 }
997 
998 BPF_CALL_5(bpf_snprintf_btf, char *, str, u32, str_size, struct btf_ptr *, ptr,
999 	   u32, btf_ptr_size, u64, flags)
1000 {
1001 	const struct btf *btf;
1002 	s32 btf_id;
1003 	int ret;
1004 
1005 	ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id);
1006 	if (ret)
1007 		return ret;
1008 
1009 	return btf_type_snprintf_show(btf, btf_id, ptr->ptr, str, str_size,
1010 				      flags);
1011 }
1012 
1013 const struct bpf_func_proto bpf_snprintf_btf_proto = {
1014 	.func		= bpf_snprintf_btf,
1015 	.gpl_only	= false,
1016 	.ret_type	= RET_INTEGER,
1017 	.arg1_type	= ARG_PTR_TO_MEM,
1018 	.arg2_type	= ARG_CONST_SIZE,
1019 	.arg3_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
1020 	.arg4_type	= ARG_CONST_SIZE,
1021 	.arg5_type	= ARG_ANYTHING,
1022 };
1023 
1024 BPF_CALL_1(bpf_get_func_ip_tracing, void *, ctx)
1025 {
1026 	/* This helper call is inlined by verifier. */
1027 	return ((u64 *)ctx)[-2];
1028 }
1029 
1030 static const struct bpf_func_proto bpf_get_func_ip_proto_tracing = {
1031 	.func		= bpf_get_func_ip_tracing,
1032 	.gpl_only	= true,
1033 	.ret_type	= RET_INTEGER,
1034 	.arg1_type	= ARG_PTR_TO_CTX,
1035 };
1036 
1037 #ifdef CONFIG_X86_KERNEL_IBT
1038 static unsigned long get_entry_ip(unsigned long fentry_ip)
1039 {
1040 	u32 instr;
1041 
1042 	/* Being extra safe in here in case entry ip is on the page-edge. */
1043 	if (get_kernel_nofault(instr, (u32 *) fentry_ip - 1))
1044 		return fentry_ip;
1045 	if (is_endbr(instr))
1046 		fentry_ip -= ENDBR_INSN_SIZE;
1047 	return fentry_ip;
1048 }
1049 #else
1050 #define get_entry_ip(fentry_ip) fentry_ip
1051 #endif
1052 
1053 BPF_CALL_1(bpf_get_func_ip_kprobe, struct pt_regs *, regs)
1054 {
1055 	struct kprobe *kp = kprobe_running();
1056 
1057 	if (!kp || !(kp->flags & KPROBE_FLAG_ON_FUNC_ENTRY))
1058 		return 0;
1059 
1060 	return get_entry_ip((uintptr_t)kp->addr);
1061 }
1062 
1063 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe = {
1064 	.func		= bpf_get_func_ip_kprobe,
1065 	.gpl_only	= true,
1066 	.ret_type	= RET_INTEGER,
1067 	.arg1_type	= ARG_PTR_TO_CTX,
1068 };
1069 
1070 BPF_CALL_1(bpf_get_func_ip_kprobe_multi, struct pt_regs *, regs)
1071 {
1072 	return bpf_kprobe_multi_entry_ip(current->bpf_ctx);
1073 }
1074 
1075 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe_multi = {
1076 	.func		= bpf_get_func_ip_kprobe_multi,
1077 	.gpl_only	= false,
1078 	.ret_type	= RET_INTEGER,
1079 	.arg1_type	= ARG_PTR_TO_CTX,
1080 };
1081 
1082 BPF_CALL_1(bpf_get_attach_cookie_kprobe_multi, struct pt_regs *, regs)
1083 {
1084 	return bpf_kprobe_multi_cookie(current->bpf_ctx);
1085 }
1086 
1087 static const struct bpf_func_proto bpf_get_attach_cookie_proto_kmulti = {
1088 	.func		= bpf_get_attach_cookie_kprobe_multi,
1089 	.gpl_only	= false,
1090 	.ret_type	= RET_INTEGER,
1091 	.arg1_type	= ARG_PTR_TO_CTX,
1092 };
1093 
1094 BPF_CALL_1(bpf_get_attach_cookie_trace, void *, ctx)
1095 {
1096 	struct bpf_trace_run_ctx *run_ctx;
1097 
1098 	run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx);
1099 	return run_ctx->bpf_cookie;
1100 }
1101 
1102 static const struct bpf_func_proto bpf_get_attach_cookie_proto_trace = {
1103 	.func		= bpf_get_attach_cookie_trace,
1104 	.gpl_only	= false,
1105 	.ret_type	= RET_INTEGER,
1106 	.arg1_type	= ARG_PTR_TO_CTX,
1107 };
1108 
1109 BPF_CALL_1(bpf_get_attach_cookie_pe, struct bpf_perf_event_data_kern *, ctx)
1110 {
1111 	return ctx->event->bpf_cookie;
1112 }
1113 
1114 static const struct bpf_func_proto bpf_get_attach_cookie_proto_pe = {
1115 	.func		= bpf_get_attach_cookie_pe,
1116 	.gpl_only	= false,
1117 	.ret_type	= RET_INTEGER,
1118 	.arg1_type	= ARG_PTR_TO_CTX,
1119 };
1120 
1121 BPF_CALL_1(bpf_get_attach_cookie_tracing, void *, ctx)
1122 {
1123 	struct bpf_trace_run_ctx *run_ctx;
1124 
1125 	run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx);
1126 	return run_ctx->bpf_cookie;
1127 }
1128 
1129 static const struct bpf_func_proto bpf_get_attach_cookie_proto_tracing = {
1130 	.func		= bpf_get_attach_cookie_tracing,
1131 	.gpl_only	= false,
1132 	.ret_type	= RET_INTEGER,
1133 	.arg1_type	= ARG_PTR_TO_CTX,
1134 };
1135 
1136 BPF_CALL_3(bpf_get_branch_snapshot, void *, buf, u32, size, u64, flags)
1137 {
1138 #ifndef CONFIG_X86
1139 	return -ENOENT;
1140 #else
1141 	static const u32 br_entry_size = sizeof(struct perf_branch_entry);
1142 	u32 entry_cnt = size / br_entry_size;
1143 
1144 	entry_cnt = static_call(perf_snapshot_branch_stack)(buf, entry_cnt);
1145 
1146 	if (unlikely(flags))
1147 		return -EINVAL;
1148 
1149 	if (!entry_cnt)
1150 		return -ENOENT;
1151 
1152 	return entry_cnt * br_entry_size;
1153 #endif
1154 }
1155 
1156 static const struct bpf_func_proto bpf_get_branch_snapshot_proto = {
1157 	.func		= bpf_get_branch_snapshot,
1158 	.gpl_only	= true,
1159 	.ret_type	= RET_INTEGER,
1160 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
1161 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
1162 };
1163 
1164 BPF_CALL_3(get_func_arg, void *, ctx, u32, n, u64 *, value)
1165 {
1166 	/* This helper call is inlined by verifier. */
1167 	u64 nr_args = ((u64 *)ctx)[-1];
1168 
1169 	if ((u64) n >= nr_args)
1170 		return -EINVAL;
1171 	*value = ((u64 *)ctx)[n];
1172 	return 0;
1173 }
1174 
1175 static const struct bpf_func_proto bpf_get_func_arg_proto = {
1176 	.func		= get_func_arg,
1177 	.ret_type	= RET_INTEGER,
1178 	.arg1_type	= ARG_PTR_TO_CTX,
1179 	.arg2_type	= ARG_ANYTHING,
1180 	.arg3_type	= ARG_PTR_TO_LONG,
1181 };
1182 
1183 BPF_CALL_2(get_func_ret, void *, ctx, u64 *, value)
1184 {
1185 	/* This helper call is inlined by verifier. */
1186 	u64 nr_args = ((u64 *)ctx)[-1];
1187 
1188 	*value = ((u64 *)ctx)[nr_args];
1189 	return 0;
1190 }
1191 
1192 static const struct bpf_func_proto bpf_get_func_ret_proto = {
1193 	.func		= get_func_ret,
1194 	.ret_type	= RET_INTEGER,
1195 	.arg1_type	= ARG_PTR_TO_CTX,
1196 	.arg2_type	= ARG_PTR_TO_LONG,
1197 };
1198 
1199 BPF_CALL_1(get_func_arg_cnt, void *, ctx)
1200 {
1201 	/* This helper call is inlined by verifier. */
1202 	return ((u64 *)ctx)[-1];
1203 }
1204 
1205 static const struct bpf_func_proto bpf_get_func_arg_cnt_proto = {
1206 	.func		= get_func_arg_cnt,
1207 	.ret_type	= RET_INTEGER,
1208 	.arg1_type	= ARG_PTR_TO_CTX,
1209 };
1210 
1211 #ifdef CONFIG_KEYS
1212 __diag_push();
1213 __diag_ignore_all("-Wmissing-prototypes",
1214 		  "kfuncs which will be used in BPF programs");
1215 
1216 /**
1217  * bpf_lookup_user_key - lookup a key by its serial
1218  * @serial: key handle serial number
1219  * @flags: lookup-specific flags
1220  *
1221  * Search a key with a given *serial* and the provided *flags*.
1222  * If found, increment the reference count of the key by one, and
1223  * return it in the bpf_key structure.
1224  *
1225  * The bpf_key structure must be passed to bpf_key_put() when done
1226  * with it, so that the key reference count is decremented and the
1227  * bpf_key structure is freed.
1228  *
1229  * Permission checks are deferred to the time the key is used by
1230  * one of the available key-specific kfuncs.
1231  *
1232  * Set *flags* with KEY_LOOKUP_CREATE, to attempt creating a requested
1233  * special keyring (e.g. session keyring), if it doesn't yet exist.
1234  * Set *flags* with KEY_LOOKUP_PARTIAL, to lookup a key without waiting
1235  * for the key construction, and to retrieve uninstantiated keys (keys
1236  * without data attached to them).
1237  *
1238  * Return: a bpf_key pointer with a valid key pointer if the key is found, a
1239  *         NULL pointer otherwise.
1240  */
1241 struct bpf_key *bpf_lookup_user_key(u32 serial, u64 flags)
1242 {
1243 	key_ref_t key_ref;
1244 	struct bpf_key *bkey;
1245 
1246 	if (flags & ~KEY_LOOKUP_ALL)
1247 		return NULL;
1248 
1249 	/*
1250 	 * Permission check is deferred until the key is used, as the
1251 	 * intent of the caller is unknown here.
1252 	 */
1253 	key_ref = lookup_user_key(serial, flags, KEY_DEFER_PERM_CHECK);
1254 	if (IS_ERR(key_ref))
1255 		return NULL;
1256 
1257 	bkey = kmalloc(sizeof(*bkey), GFP_KERNEL);
1258 	if (!bkey) {
1259 		key_put(key_ref_to_ptr(key_ref));
1260 		return NULL;
1261 	}
1262 
1263 	bkey->key = key_ref_to_ptr(key_ref);
1264 	bkey->has_ref = true;
1265 
1266 	return bkey;
1267 }
1268 
1269 /**
1270  * bpf_lookup_system_key - lookup a key by a system-defined ID
1271  * @id: key ID
1272  *
1273  * Obtain a bpf_key structure with a key pointer set to the passed key ID.
1274  * The key pointer is marked as invalid, to prevent bpf_key_put() from
1275  * attempting to decrement the key reference count on that pointer. The key
1276  * pointer set in such way is currently understood only by
1277  * verify_pkcs7_signature().
1278  *
1279  * Set *id* to one of the values defined in include/linux/verification.h:
1280  * 0 for the primary keyring (immutable keyring of system keys);
1281  * VERIFY_USE_SECONDARY_KEYRING for both the primary and secondary keyring
1282  * (where keys can be added only if they are vouched for by existing keys
1283  * in those keyrings); VERIFY_USE_PLATFORM_KEYRING for the platform
1284  * keyring (primarily used by the integrity subsystem to verify a kexec'ed
1285  * kerned image and, possibly, the initramfs signature).
1286  *
1287  * Return: a bpf_key pointer with an invalid key pointer set from the
1288  *         pre-determined ID on success, a NULL pointer otherwise
1289  */
1290 struct bpf_key *bpf_lookup_system_key(u64 id)
1291 {
1292 	struct bpf_key *bkey;
1293 
1294 	if (system_keyring_id_check(id) < 0)
1295 		return NULL;
1296 
1297 	bkey = kmalloc(sizeof(*bkey), GFP_ATOMIC);
1298 	if (!bkey)
1299 		return NULL;
1300 
1301 	bkey->key = (struct key *)(unsigned long)id;
1302 	bkey->has_ref = false;
1303 
1304 	return bkey;
1305 }
1306 
1307 /**
1308  * bpf_key_put - decrement key reference count if key is valid and free bpf_key
1309  * @bkey: bpf_key structure
1310  *
1311  * Decrement the reference count of the key inside *bkey*, if the pointer
1312  * is valid, and free *bkey*.
1313  */
1314 void bpf_key_put(struct bpf_key *bkey)
1315 {
1316 	if (bkey->has_ref)
1317 		key_put(bkey->key);
1318 
1319 	kfree(bkey);
1320 }
1321 
1322 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION
1323 /**
1324  * bpf_verify_pkcs7_signature - verify a PKCS#7 signature
1325  * @data_ptr: data to verify
1326  * @sig_ptr: signature of the data
1327  * @trusted_keyring: keyring with keys trusted for signature verification
1328  *
1329  * Verify the PKCS#7 signature *sig_ptr* against the supplied *data_ptr*
1330  * with keys in a keyring referenced by *trusted_keyring*.
1331  *
1332  * Return: 0 on success, a negative value on error.
1333  */
1334 int bpf_verify_pkcs7_signature(struct bpf_dynptr_kern *data_ptr,
1335 			       struct bpf_dynptr_kern *sig_ptr,
1336 			       struct bpf_key *trusted_keyring)
1337 {
1338 	int ret;
1339 
1340 	if (trusted_keyring->has_ref) {
1341 		/*
1342 		 * Do the permission check deferred in bpf_lookup_user_key().
1343 		 * See bpf_lookup_user_key() for more details.
1344 		 *
1345 		 * A call to key_task_permission() here would be redundant, as
1346 		 * it is already done by keyring_search() called by
1347 		 * find_asymmetric_key().
1348 		 */
1349 		ret = key_validate(trusted_keyring->key);
1350 		if (ret < 0)
1351 			return ret;
1352 	}
1353 
1354 	return verify_pkcs7_signature(data_ptr->data,
1355 				      bpf_dynptr_get_size(data_ptr),
1356 				      sig_ptr->data,
1357 				      bpf_dynptr_get_size(sig_ptr),
1358 				      trusted_keyring->key,
1359 				      VERIFYING_UNSPECIFIED_SIGNATURE, NULL,
1360 				      NULL);
1361 }
1362 #endif /* CONFIG_SYSTEM_DATA_VERIFICATION */
1363 
1364 __diag_pop();
1365 
1366 BTF_SET8_START(key_sig_kfunc_set)
1367 BTF_ID_FLAGS(func, bpf_lookup_user_key, KF_ACQUIRE | KF_RET_NULL | KF_SLEEPABLE)
1368 BTF_ID_FLAGS(func, bpf_lookup_system_key, KF_ACQUIRE | KF_RET_NULL)
1369 BTF_ID_FLAGS(func, bpf_key_put, KF_RELEASE)
1370 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION
1371 BTF_ID_FLAGS(func, bpf_verify_pkcs7_signature, KF_SLEEPABLE)
1372 #endif
1373 BTF_SET8_END(key_sig_kfunc_set)
1374 
1375 static const struct btf_kfunc_id_set bpf_key_sig_kfunc_set = {
1376 	.owner = THIS_MODULE,
1377 	.set = &key_sig_kfunc_set,
1378 };
1379 
1380 static int __init bpf_key_sig_kfuncs_init(void)
1381 {
1382 	return register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING,
1383 					 &bpf_key_sig_kfunc_set);
1384 }
1385 
1386 late_initcall(bpf_key_sig_kfuncs_init);
1387 #endif /* CONFIG_KEYS */
1388 
1389 static const struct bpf_func_proto *
1390 bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1391 {
1392 	switch (func_id) {
1393 	case BPF_FUNC_map_lookup_elem:
1394 		return &bpf_map_lookup_elem_proto;
1395 	case BPF_FUNC_map_update_elem:
1396 		return &bpf_map_update_elem_proto;
1397 	case BPF_FUNC_map_delete_elem:
1398 		return &bpf_map_delete_elem_proto;
1399 	case BPF_FUNC_map_push_elem:
1400 		return &bpf_map_push_elem_proto;
1401 	case BPF_FUNC_map_pop_elem:
1402 		return &bpf_map_pop_elem_proto;
1403 	case BPF_FUNC_map_peek_elem:
1404 		return &bpf_map_peek_elem_proto;
1405 	case BPF_FUNC_map_lookup_percpu_elem:
1406 		return &bpf_map_lookup_percpu_elem_proto;
1407 	case BPF_FUNC_ktime_get_ns:
1408 		return &bpf_ktime_get_ns_proto;
1409 	case BPF_FUNC_ktime_get_boot_ns:
1410 		return &bpf_ktime_get_boot_ns_proto;
1411 	case BPF_FUNC_tail_call:
1412 		return &bpf_tail_call_proto;
1413 	case BPF_FUNC_get_current_pid_tgid:
1414 		return &bpf_get_current_pid_tgid_proto;
1415 	case BPF_FUNC_get_current_task:
1416 		return &bpf_get_current_task_proto;
1417 	case BPF_FUNC_get_current_task_btf:
1418 		return &bpf_get_current_task_btf_proto;
1419 	case BPF_FUNC_task_pt_regs:
1420 		return &bpf_task_pt_regs_proto;
1421 	case BPF_FUNC_get_current_uid_gid:
1422 		return &bpf_get_current_uid_gid_proto;
1423 	case BPF_FUNC_get_current_comm:
1424 		return &bpf_get_current_comm_proto;
1425 	case BPF_FUNC_trace_printk:
1426 		return bpf_get_trace_printk_proto();
1427 	case BPF_FUNC_get_smp_processor_id:
1428 		return &bpf_get_smp_processor_id_proto;
1429 	case BPF_FUNC_get_numa_node_id:
1430 		return &bpf_get_numa_node_id_proto;
1431 	case BPF_FUNC_perf_event_read:
1432 		return &bpf_perf_event_read_proto;
1433 	case BPF_FUNC_current_task_under_cgroup:
1434 		return &bpf_current_task_under_cgroup_proto;
1435 	case BPF_FUNC_get_prandom_u32:
1436 		return &bpf_get_prandom_u32_proto;
1437 	case BPF_FUNC_probe_write_user:
1438 		return security_locked_down(LOCKDOWN_BPF_WRITE_USER) < 0 ?
1439 		       NULL : bpf_get_probe_write_proto();
1440 	case BPF_FUNC_probe_read_user:
1441 		return &bpf_probe_read_user_proto;
1442 	case BPF_FUNC_probe_read_kernel:
1443 		return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
1444 		       NULL : &bpf_probe_read_kernel_proto;
1445 	case BPF_FUNC_probe_read_user_str:
1446 		return &bpf_probe_read_user_str_proto;
1447 	case BPF_FUNC_probe_read_kernel_str:
1448 		return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
1449 		       NULL : &bpf_probe_read_kernel_str_proto;
1450 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
1451 	case BPF_FUNC_probe_read:
1452 		return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
1453 		       NULL : &bpf_probe_read_compat_proto;
1454 	case BPF_FUNC_probe_read_str:
1455 		return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
1456 		       NULL : &bpf_probe_read_compat_str_proto;
1457 #endif
1458 #ifdef CONFIG_CGROUPS
1459 	case BPF_FUNC_get_current_cgroup_id:
1460 		return &bpf_get_current_cgroup_id_proto;
1461 	case BPF_FUNC_get_current_ancestor_cgroup_id:
1462 		return &bpf_get_current_ancestor_cgroup_id_proto;
1463 	case BPF_FUNC_cgrp_storage_get:
1464 		return &bpf_cgrp_storage_get_proto;
1465 	case BPF_FUNC_cgrp_storage_delete:
1466 		return &bpf_cgrp_storage_delete_proto;
1467 #endif
1468 	case BPF_FUNC_send_signal:
1469 		return &bpf_send_signal_proto;
1470 	case BPF_FUNC_send_signal_thread:
1471 		return &bpf_send_signal_thread_proto;
1472 	case BPF_FUNC_perf_event_read_value:
1473 		return &bpf_perf_event_read_value_proto;
1474 	case BPF_FUNC_get_ns_current_pid_tgid:
1475 		return &bpf_get_ns_current_pid_tgid_proto;
1476 	case BPF_FUNC_ringbuf_output:
1477 		return &bpf_ringbuf_output_proto;
1478 	case BPF_FUNC_ringbuf_reserve:
1479 		return &bpf_ringbuf_reserve_proto;
1480 	case BPF_FUNC_ringbuf_submit:
1481 		return &bpf_ringbuf_submit_proto;
1482 	case BPF_FUNC_ringbuf_discard:
1483 		return &bpf_ringbuf_discard_proto;
1484 	case BPF_FUNC_ringbuf_query:
1485 		return &bpf_ringbuf_query_proto;
1486 	case BPF_FUNC_jiffies64:
1487 		return &bpf_jiffies64_proto;
1488 	case BPF_FUNC_get_task_stack:
1489 		return &bpf_get_task_stack_proto;
1490 	case BPF_FUNC_copy_from_user:
1491 		return &bpf_copy_from_user_proto;
1492 	case BPF_FUNC_copy_from_user_task:
1493 		return &bpf_copy_from_user_task_proto;
1494 	case BPF_FUNC_snprintf_btf:
1495 		return &bpf_snprintf_btf_proto;
1496 	case BPF_FUNC_per_cpu_ptr:
1497 		return &bpf_per_cpu_ptr_proto;
1498 	case BPF_FUNC_this_cpu_ptr:
1499 		return &bpf_this_cpu_ptr_proto;
1500 	case BPF_FUNC_task_storage_get:
1501 		if (bpf_prog_check_recur(prog))
1502 			return &bpf_task_storage_get_recur_proto;
1503 		return &bpf_task_storage_get_proto;
1504 	case BPF_FUNC_task_storage_delete:
1505 		if (bpf_prog_check_recur(prog))
1506 			return &bpf_task_storage_delete_recur_proto;
1507 		return &bpf_task_storage_delete_proto;
1508 	case BPF_FUNC_for_each_map_elem:
1509 		return &bpf_for_each_map_elem_proto;
1510 	case BPF_FUNC_snprintf:
1511 		return &bpf_snprintf_proto;
1512 	case BPF_FUNC_get_func_ip:
1513 		return &bpf_get_func_ip_proto_tracing;
1514 	case BPF_FUNC_get_branch_snapshot:
1515 		return &bpf_get_branch_snapshot_proto;
1516 	case BPF_FUNC_find_vma:
1517 		return &bpf_find_vma_proto;
1518 	case BPF_FUNC_trace_vprintk:
1519 		return bpf_get_trace_vprintk_proto();
1520 	default:
1521 		return bpf_base_func_proto(func_id);
1522 	}
1523 }
1524 
1525 static const struct bpf_func_proto *
1526 kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1527 {
1528 	switch (func_id) {
1529 	case BPF_FUNC_perf_event_output:
1530 		return &bpf_perf_event_output_proto;
1531 	case BPF_FUNC_get_stackid:
1532 		return &bpf_get_stackid_proto;
1533 	case BPF_FUNC_get_stack:
1534 		return &bpf_get_stack_proto;
1535 #ifdef CONFIG_BPF_KPROBE_OVERRIDE
1536 	case BPF_FUNC_override_return:
1537 		return &bpf_override_return_proto;
1538 #endif
1539 	case BPF_FUNC_get_func_ip:
1540 		return prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI ?
1541 			&bpf_get_func_ip_proto_kprobe_multi :
1542 			&bpf_get_func_ip_proto_kprobe;
1543 	case BPF_FUNC_get_attach_cookie:
1544 		return prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI ?
1545 			&bpf_get_attach_cookie_proto_kmulti :
1546 			&bpf_get_attach_cookie_proto_trace;
1547 	default:
1548 		return bpf_tracing_func_proto(func_id, prog);
1549 	}
1550 }
1551 
1552 /* bpf+kprobe programs can access fields of 'struct pt_regs' */
1553 static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
1554 					const struct bpf_prog *prog,
1555 					struct bpf_insn_access_aux *info)
1556 {
1557 	if (off < 0 || off >= sizeof(struct pt_regs))
1558 		return false;
1559 	if (type != BPF_READ)
1560 		return false;
1561 	if (off % size != 0)
1562 		return false;
1563 	/*
1564 	 * Assertion for 32 bit to make sure last 8 byte access
1565 	 * (BPF_DW) to the last 4 byte member is disallowed.
1566 	 */
1567 	if (off + size > sizeof(struct pt_regs))
1568 		return false;
1569 
1570 	return true;
1571 }
1572 
1573 const struct bpf_verifier_ops kprobe_verifier_ops = {
1574 	.get_func_proto  = kprobe_prog_func_proto,
1575 	.is_valid_access = kprobe_prog_is_valid_access,
1576 };
1577 
1578 const struct bpf_prog_ops kprobe_prog_ops = {
1579 };
1580 
1581 BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map,
1582 	   u64, flags, void *, data, u64, size)
1583 {
1584 	struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1585 
1586 	/*
1587 	 * r1 points to perf tracepoint buffer where first 8 bytes are hidden
1588 	 * from bpf program and contain a pointer to 'struct pt_regs'. Fetch it
1589 	 * from there and call the same bpf_perf_event_output() helper inline.
1590 	 */
1591 	return ____bpf_perf_event_output(regs, map, flags, data, size);
1592 }
1593 
1594 static const struct bpf_func_proto bpf_perf_event_output_proto_tp = {
1595 	.func		= bpf_perf_event_output_tp,
1596 	.gpl_only	= true,
1597 	.ret_type	= RET_INTEGER,
1598 	.arg1_type	= ARG_PTR_TO_CTX,
1599 	.arg2_type	= ARG_CONST_MAP_PTR,
1600 	.arg3_type	= ARG_ANYTHING,
1601 	.arg4_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
1602 	.arg5_type	= ARG_CONST_SIZE_OR_ZERO,
1603 };
1604 
1605 BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map,
1606 	   u64, flags)
1607 {
1608 	struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1609 
1610 	/*
1611 	 * Same comment as in bpf_perf_event_output_tp(), only that this time
1612 	 * the other helper's function body cannot be inlined due to being
1613 	 * external, thus we need to call raw helper function.
1614 	 */
1615 	return bpf_get_stackid((unsigned long) regs, (unsigned long) map,
1616 			       flags, 0, 0);
1617 }
1618 
1619 static const struct bpf_func_proto bpf_get_stackid_proto_tp = {
1620 	.func		= bpf_get_stackid_tp,
1621 	.gpl_only	= true,
1622 	.ret_type	= RET_INTEGER,
1623 	.arg1_type	= ARG_PTR_TO_CTX,
1624 	.arg2_type	= ARG_CONST_MAP_PTR,
1625 	.arg3_type	= ARG_ANYTHING,
1626 };
1627 
1628 BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size,
1629 	   u64, flags)
1630 {
1631 	struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1632 
1633 	return bpf_get_stack((unsigned long) regs, (unsigned long) buf,
1634 			     (unsigned long) size, flags, 0);
1635 }
1636 
1637 static const struct bpf_func_proto bpf_get_stack_proto_tp = {
1638 	.func		= bpf_get_stack_tp,
1639 	.gpl_only	= true,
1640 	.ret_type	= RET_INTEGER,
1641 	.arg1_type	= ARG_PTR_TO_CTX,
1642 	.arg2_type	= ARG_PTR_TO_UNINIT_MEM,
1643 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
1644 	.arg4_type	= ARG_ANYTHING,
1645 };
1646 
1647 static const struct bpf_func_proto *
1648 tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1649 {
1650 	switch (func_id) {
1651 	case BPF_FUNC_perf_event_output:
1652 		return &bpf_perf_event_output_proto_tp;
1653 	case BPF_FUNC_get_stackid:
1654 		return &bpf_get_stackid_proto_tp;
1655 	case BPF_FUNC_get_stack:
1656 		return &bpf_get_stack_proto_tp;
1657 	case BPF_FUNC_get_attach_cookie:
1658 		return &bpf_get_attach_cookie_proto_trace;
1659 	default:
1660 		return bpf_tracing_func_proto(func_id, prog);
1661 	}
1662 }
1663 
1664 static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type,
1665 				    const struct bpf_prog *prog,
1666 				    struct bpf_insn_access_aux *info)
1667 {
1668 	if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE)
1669 		return false;
1670 	if (type != BPF_READ)
1671 		return false;
1672 	if (off % size != 0)
1673 		return false;
1674 
1675 	BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(__u64));
1676 	return true;
1677 }
1678 
1679 const struct bpf_verifier_ops tracepoint_verifier_ops = {
1680 	.get_func_proto  = tp_prog_func_proto,
1681 	.is_valid_access = tp_prog_is_valid_access,
1682 };
1683 
1684 const struct bpf_prog_ops tracepoint_prog_ops = {
1685 };
1686 
1687 BPF_CALL_3(bpf_perf_prog_read_value, struct bpf_perf_event_data_kern *, ctx,
1688 	   struct bpf_perf_event_value *, buf, u32, size)
1689 {
1690 	int err = -EINVAL;
1691 
1692 	if (unlikely(size != sizeof(struct bpf_perf_event_value)))
1693 		goto clear;
1694 	err = perf_event_read_local(ctx->event, &buf->counter, &buf->enabled,
1695 				    &buf->running);
1696 	if (unlikely(err))
1697 		goto clear;
1698 	return 0;
1699 clear:
1700 	memset(buf, 0, size);
1701 	return err;
1702 }
1703 
1704 static const struct bpf_func_proto bpf_perf_prog_read_value_proto = {
1705          .func           = bpf_perf_prog_read_value,
1706          .gpl_only       = true,
1707          .ret_type       = RET_INTEGER,
1708          .arg1_type      = ARG_PTR_TO_CTX,
1709          .arg2_type      = ARG_PTR_TO_UNINIT_MEM,
1710          .arg3_type      = ARG_CONST_SIZE,
1711 };
1712 
1713 BPF_CALL_4(bpf_read_branch_records, struct bpf_perf_event_data_kern *, ctx,
1714 	   void *, buf, u32, size, u64, flags)
1715 {
1716 	static const u32 br_entry_size = sizeof(struct perf_branch_entry);
1717 	struct perf_branch_stack *br_stack = ctx->data->br_stack;
1718 	u32 to_copy;
1719 
1720 	if (unlikely(flags & ~BPF_F_GET_BRANCH_RECORDS_SIZE))
1721 		return -EINVAL;
1722 
1723 	if (unlikely(!(ctx->data->sample_flags & PERF_SAMPLE_BRANCH_STACK)))
1724 		return -ENOENT;
1725 
1726 	if (unlikely(!br_stack))
1727 		return -ENOENT;
1728 
1729 	if (flags & BPF_F_GET_BRANCH_RECORDS_SIZE)
1730 		return br_stack->nr * br_entry_size;
1731 
1732 	if (!buf || (size % br_entry_size != 0))
1733 		return -EINVAL;
1734 
1735 	to_copy = min_t(u32, br_stack->nr * br_entry_size, size);
1736 	memcpy(buf, br_stack->entries, to_copy);
1737 
1738 	return to_copy;
1739 }
1740 
1741 static const struct bpf_func_proto bpf_read_branch_records_proto = {
1742 	.func           = bpf_read_branch_records,
1743 	.gpl_only       = true,
1744 	.ret_type       = RET_INTEGER,
1745 	.arg1_type      = ARG_PTR_TO_CTX,
1746 	.arg2_type      = ARG_PTR_TO_MEM_OR_NULL,
1747 	.arg3_type      = ARG_CONST_SIZE_OR_ZERO,
1748 	.arg4_type      = ARG_ANYTHING,
1749 };
1750 
1751 static const struct bpf_func_proto *
1752 pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1753 {
1754 	switch (func_id) {
1755 	case BPF_FUNC_perf_event_output:
1756 		return &bpf_perf_event_output_proto_tp;
1757 	case BPF_FUNC_get_stackid:
1758 		return &bpf_get_stackid_proto_pe;
1759 	case BPF_FUNC_get_stack:
1760 		return &bpf_get_stack_proto_pe;
1761 	case BPF_FUNC_perf_prog_read_value:
1762 		return &bpf_perf_prog_read_value_proto;
1763 	case BPF_FUNC_read_branch_records:
1764 		return &bpf_read_branch_records_proto;
1765 	case BPF_FUNC_get_attach_cookie:
1766 		return &bpf_get_attach_cookie_proto_pe;
1767 	default:
1768 		return bpf_tracing_func_proto(func_id, prog);
1769 	}
1770 }
1771 
1772 /*
1773  * bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp
1774  * to avoid potential recursive reuse issue when/if tracepoints are added
1775  * inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack.
1776  *
1777  * Since raw tracepoints run despite bpf_prog_active, support concurrent usage
1778  * in normal, irq, and nmi context.
1779  */
1780 struct bpf_raw_tp_regs {
1781 	struct pt_regs regs[3];
1782 };
1783 static DEFINE_PER_CPU(struct bpf_raw_tp_regs, bpf_raw_tp_regs);
1784 static DEFINE_PER_CPU(int, bpf_raw_tp_nest_level);
1785 static struct pt_regs *get_bpf_raw_tp_regs(void)
1786 {
1787 	struct bpf_raw_tp_regs *tp_regs = this_cpu_ptr(&bpf_raw_tp_regs);
1788 	int nest_level = this_cpu_inc_return(bpf_raw_tp_nest_level);
1789 
1790 	if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(tp_regs->regs))) {
1791 		this_cpu_dec(bpf_raw_tp_nest_level);
1792 		return ERR_PTR(-EBUSY);
1793 	}
1794 
1795 	return &tp_regs->regs[nest_level - 1];
1796 }
1797 
1798 static void put_bpf_raw_tp_regs(void)
1799 {
1800 	this_cpu_dec(bpf_raw_tp_nest_level);
1801 }
1802 
1803 BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args,
1804 	   struct bpf_map *, map, u64, flags, void *, data, u64, size)
1805 {
1806 	struct pt_regs *regs = get_bpf_raw_tp_regs();
1807 	int ret;
1808 
1809 	if (IS_ERR(regs))
1810 		return PTR_ERR(regs);
1811 
1812 	perf_fetch_caller_regs(regs);
1813 	ret = ____bpf_perf_event_output(regs, map, flags, data, size);
1814 
1815 	put_bpf_raw_tp_regs();
1816 	return ret;
1817 }
1818 
1819 static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = {
1820 	.func		= bpf_perf_event_output_raw_tp,
1821 	.gpl_only	= true,
1822 	.ret_type	= RET_INTEGER,
1823 	.arg1_type	= ARG_PTR_TO_CTX,
1824 	.arg2_type	= ARG_CONST_MAP_PTR,
1825 	.arg3_type	= ARG_ANYTHING,
1826 	.arg4_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
1827 	.arg5_type	= ARG_CONST_SIZE_OR_ZERO,
1828 };
1829 
1830 extern const struct bpf_func_proto bpf_skb_output_proto;
1831 extern const struct bpf_func_proto bpf_xdp_output_proto;
1832 extern const struct bpf_func_proto bpf_xdp_get_buff_len_trace_proto;
1833 
1834 BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args,
1835 	   struct bpf_map *, map, u64, flags)
1836 {
1837 	struct pt_regs *regs = get_bpf_raw_tp_regs();
1838 	int ret;
1839 
1840 	if (IS_ERR(regs))
1841 		return PTR_ERR(regs);
1842 
1843 	perf_fetch_caller_regs(regs);
1844 	/* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */
1845 	ret = bpf_get_stackid((unsigned long) regs, (unsigned long) map,
1846 			      flags, 0, 0);
1847 	put_bpf_raw_tp_regs();
1848 	return ret;
1849 }
1850 
1851 static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = {
1852 	.func		= bpf_get_stackid_raw_tp,
1853 	.gpl_only	= true,
1854 	.ret_type	= RET_INTEGER,
1855 	.arg1_type	= ARG_PTR_TO_CTX,
1856 	.arg2_type	= ARG_CONST_MAP_PTR,
1857 	.arg3_type	= ARG_ANYTHING,
1858 };
1859 
1860 BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args,
1861 	   void *, buf, u32, size, u64, flags)
1862 {
1863 	struct pt_regs *regs = get_bpf_raw_tp_regs();
1864 	int ret;
1865 
1866 	if (IS_ERR(regs))
1867 		return PTR_ERR(regs);
1868 
1869 	perf_fetch_caller_regs(regs);
1870 	ret = bpf_get_stack((unsigned long) regs, (unsigned long) buf,
1871 			    (unsigned long) size, flags, 0);
1872 	put_bpf_raw_tp_regs();
1873 	return ret;
1874 }
1875 
1876 static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = {
1877 	.func		= bpf_get_stack_raw_tp,
1878 	.gpl_only	= true,
1879 	.ret_type	= RET_INTEGER,
1880 	.arg1_type	= ARG_PTR_TO_CTX,
1881 	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
1882 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
1883 	.arg4_type	= ARG_ANYTHING,
1884 };
1885 
1886 static const struct bpf_func_proto *
1887 raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1888 {
1889 	switch (func_id) {
1890 	case BPF_FUNC_perf_event_output:
1891 		return &bpf_perf_event_output_proto_raw_tp;
1892 	case BPF_FUNC_get_stackid:
1893 		return &bpf_get_stackid_proto_raw_tp;
1894 	case BPF_FUNC_get_stack:
1895 		return &bpf_get_stack_proto_raw_tp;
1896 	default:
1897 		return bpf_tracing_func_proto(func_id, prog);
1898 	}
1899 }
1900 
1901 const struct bpf_func_proto *
1902 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1903 {
1904 	const struct bpf_func_proto *fn;
1905 
1906 	switch (func_id) {
1907 #ifdef CONFIG_NET
1908 	case BPF_FUNC_skb_output:
1909 		return &bpf_skb_output_proto;
1910 	case BPF_FUNC_xdp_output:
1911 		return &bpf_xdp_output_proto;
1912 	case BPF_FUNC_skc_to_tcp6_sock:
1913 		return &bpf_skc_to_tcp6_sock_proto;
1914 	case BPF_FUNC_skc_to_tcp_sock:
1915 		return &bpf_skc_to_tcp_sock_proto;
1916 	case BPF_FUNC_skc_to_tcp_timewait_sock:
1917 		return &bpf_skc_to_tcp_timewait_sock_proto;
1918 	case BPF_FUNC_skc_to_tcp_request_sock:
1919 		return &bpf_skc_to_tcp_request_sock_proto;
1920 	case BPF_FUNC_skc_to_udp6_sock:
1921 		return &bpf_skc_to_udp6_sock_proto;
1922 	case BPF_FUNC_skc_to_unix_sock:
1923 		return &bpf_skc_to_unix_sock_proto;
1924 	case BPF_FUNC_skc_to_mptcp_sock:
1925 		return &bpf_skc_to_mptcp_sock_proto;
1926 	case BPF_FUNC_sk_storage_get:
1927 		return &bpf_sk_storage_get_tracing_proto;
1928 	case BPF_FUNC_sk_storage_delete:
1929 		return &bpf_sk_storage_delete_tracing_proto;
1930 	case BPF_FUNC_sock_from_file:
1931 		return &bpf_sock_from_file_proto;
1932 	case BPF_FUNC_get_socket_cookie:
1933 		return &bpf_get_socket_ptr_cookie_proto;
1934 	case BPF_FUNC_xdp_get_buff_len:
1935 		return &bpf_xdp_get_buff_len_trace_proto;
1936 #endif
1937 	case BPF_FUNC_seq_printf:
1938 		return prog->expected_attach_type == BPF_TRACE_ITER ?
1939 		       &bpf_seq_printf_proto :
1940 		       NULL;
1941 	case BPF_FUNC_seq_write:
1942 		return prog->expected_attach_type == BPF_TRACE_ITER ?
1943 		       &bpf_seq_write_proto :
1944 		       NULL;
1945 	case BPF_FUNC_seq_printf_btf:
1946 		return prog->expected_attach_type == BPF_TRACE_ITER ?
1947 		       &bpf_seq_printf_btf_proto :
1948 		       NULL;
1949 	case BPF_FUNC_d_path:
1950 		return &bpf_d_path_proto;
1951 	case BPF_FUNC_get_func_arg:
1952 		return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_proto : NULL;
1953 	case BPF_FUNC_get_func_ret:
1954 		return bpf_prog_has_trampoline(prog) ? &bpf_get_func_ret_proto : NULL;
1955 	case BPF_FUNC_get_func_arg_cnt:
1956 		return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_cnt_proto : NULL;
1957 	case BPF_FUNC_get_attach_cookie:
1958 		return bpf_prog_has_trampoline(prog) ? &bpf_get_attach_cookie_proto_tracing : NULL;
1959 	default:
1960 		fn = raw_tp_prog_func_proto(func_id, prog);
1961 		if (!fn && prog->expected_attach_type == BPF_TRACE_ITER)
1962 			fn = bpf_iter_get_func_proto(func_id, prog);
1963 		return fn;
1964 	}
1965 }
1966 
1967 static bool raw_tp_prog_is_valid_access(int off, int size,
1968 					enum bpf_access_type type,
1969 					const struct bpf_prog *prog,
1970 					struct bpf_insn_access_aux *info)
1971 {
1972 	return bpf_tracing_ctx_access(off, size, type);
1973 }
1974 
1975 static bool tracing_prog_is_valid_access(int off, int size,
1976 					 enum bpf_access_type type,
1977 					 const struct bpf_prog *prog,
1978 					 struct bpf_insn_access_aux *info)
1979 {
1980 	return bpf_tracing_btf_ctx_access(off, size, type, prog, info);
1981 }
1982 
1983 int __weak bpf_prog_test_run_tracing(struct bpf_prog *prog,
1984 				     const union bpf_attr *kattr,
1985 				     union bpf_attr __user *uattr)
1986 {
1987 	return -ENOTSUPP;
1988 }
1989 
1990 const struct bpf_verifier_ops raw_tracepoint_verifier_ops = {
1991 	.get_func_proto  = raw_tp_prog_func_proto,
1992 	.is_valid_access = raw_tp_prog_is_valid_access,
1993 };
1994 
1995 const struct bpf_prog_ops raw_tracepoint_prog_ops = {
1996 #ifdef CONFIG_NET
1997 	.test_run = bpf_prog_test_run_raw_tp,
1998 #endif
1999 };
2000 
2001 const struct bpf_verifier_ops tracing_verifier_ops = {
2002 	.get_func_proto  = tracing_prog_func_proto,
2003 	.is_valid_access = tracing_prog_is_valid_access,
2004 };
2005 
2006 const struct bpf_prog_ops tracing_prog_ops = {
2007 	.test_run = bpf_prog_test_run_tracing,
2008 };
2009 
2010 static bool raw_tp_writable_prog_is_valid_access(int off, int size,
2011 						 enum bpf_access_type type,
2012 						 const struct bpf_prog *prog,
2013 						 struct bpf_insn_access_aux *info)
2014 {
2015 	if (off == 0) {
2016 		if (size != sizeof(u64) || type != BPF_READ)
2017 			return false;
2018 		info->reg_type = PTR_TO_TP_BUFFER;
2019 	}
2020 	return raw_tp_prog_is_valid_access(off, size, type, prog, info);
2021 }
2022 
2023 const struct bpf_verifier_ops raw_tracepoint_writable_verifier_ops = {
2024 	.get_func_proto  = raw_tp_prog_func_proto,
2025 	.is_valid_access = raw_tp_writable_prog_is_valid_access,
2026 };
2027 
2028 const struct bpf_prog_ops raw_tracepoint_writable_prog_ops = {
2029 };
2030 
2031 static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
2032 				    const struct bpf_prog *prog,
2033 				    struct bpf_insn_access_aux *info)
2034 {
2035 	const int size_u64 = sizeof(u64);
2036 
2037 	if (off < 0 || off >= sizeof(struct bpf_perf_event_data))
2038 		return false;
2039 	if (type != BPF_READ)
2040 		return false;
2041 	if (off % size != 0) {
2042 		if (sizeof(unsigned long) != 4)
2043 			return false;
2044 		if (size != 8)
2045 			return false;
2046 		if (off % size != 4)
2047 			return false;
2048 	}
2049 
2050 	switch (off) {
2051 	case bpf_ctx_range(struct bpf_perf_event_data, sample_period):
2052 		bpf_ctx_record_field_size(info, size_u64);
2053 		if (!bpf_ctx_narrow_access_ok(off, size, size_u64))
2054 			return false;
2055 		break;
2056 	case bpf_ctx_range(struct bpf_perf_event_data, addr):
2057 		bpf_ctx_record_field_size(info, size_u64);
2058 		if (!bpf_ctx_narrow_access_ok(off, size, size_u64))
2059 			return false;
2060 		break;
2061 	default:
2062 		if (size != sizeof(long))
2063 			return false;
2064 	}
2065 
2066 	return true;
2067 }
2068 
2069 static u32 pe_prog_convert_ctx_access(enum bpf_access_type type,
2070 				      const struct bpf_insn *si,
2071 				      struct bpf_insn *insn_buf,
2072 				      struct bpf_prog *prog, u32 *target_size)
2073 {
2074 	struct bpf_insn *insn = insn_buf;
2075 
2076 	switch (si->off) {
2077 	case offsetof(struct bpf_perf_event_data, sample_period):
2078 		*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
2079 						       data), si->dst_reg, si->src_reg,
2080 				      offsetof(struct bpf_perf_event_data_kern, data));
2081 		*insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg,
2082 				      bpf_target_off(struct perf_sample_data, period, 8,
2083 						     target_size));
2084 		break;
2085 	case offsetof(struct bpf_perf_event_data, addr):
2086 		*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
2087 						       data), si->dst_reg, si->src_reg,
2088 				      offsetof(struct bpf_perf_event_data_kern, data));
2089 		*insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg,
2090 				      bpf_target_off(struct perf_sample_data, addr, 8,
2091 						     target_size));
2092 		break;
2093 	default:
2094 		*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
2095 						       regs), si->dst_reg, si->src_reg,
2096 				      offsetof(struct bpf_perf_event_data_kern, regs));
2097 		*insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg,
2098 				      si->off);
2099 		break;
2100 	}
2101 
2102 	return insn - insn_buf;
2103 }
2104 
2105 const struct bpf_verifier_ops perf_event_verifier_ops = {
2106 	.get_func_proto		= pe_prog_func_proto,
2107 	.is_valid_access	= pe_prog_is_valid_access,
2108 	.convert_ctx_access	= pe_prog_convert_ctx_access,
2109 };
2110 
2111 const struct bpf_prog_ops perf_event_prog_ops = {
2112 };
2113 
2114 static DEFINE_MUTEX(bpf_event_mutex);
2115 
2116 #define BPF_TRACE_MAX_PROGS 64
2117 
2118 int perf_event_attach_bpf_prog(struct perf_event *event,
2119 			       struct bpf_prog *prog,
2120 			       u64 bpf_cookie)
2121 {
2122 	struct bpf_prog_array *old_array;
2123 	struct bpf_prog_array *new_array;
2124 	int ret = -EEXIST;
2125 
2126 	/*
2127 	 * Kprobe override only works if they are on the function entry,
2128 	 * and only if they are on the opt-in list.
2129 	 */
2130 	if (prog->kprobe_override &&
2131 	    (!trace_kprobe_on_func_entry(event->tp_event) ||
2132 	     !trace_kprobe_error_injectable(event->tp_event)))
2133 		return -EINVAL;
2134 
2135 	mutex_lock(&bpf_event_mutex);
2136 
2137 	if (event->prog)
2138 		goto unlock;
2139 
2140 	old_array = bpf_event_rcu_dereference(event->tp_event->prog_array);
2141 	if (old_array &&
2142 	    bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) {
2143 		ret = -E2BIG;
2144 		goto unlock;
2145 	}
2146 
2147 	ret = bpf_prog_array_copy(old_array, NULL, prog, bpf_cookie, &new_array);
2148 	if (ret < 0)
2149 		goto unlock;
2150 
2151 	/* set the new array to event->tp_event and set event->prog */
2152 	event->prog = prog;
2153 	event->bpf_cookie = bpf_cookie;
2154 	rcu_assign_pointer(event->tp_event->prog_array, new_array);
2155 	bpf_prog_array_free_sleepable(old_array);
2156 
2157 unlock:
2158 	mutex_unlock(&bpf_event_mutex);
2159 	return ret;
2160 }
2161 
2162 void perf_event_detach_bpf_prog(struct perf_event *event)
2163 {
2164 	struct bpf_prog_array *old_array;
2165 	struct bpf_prog_array *new_array;
2166 	int ret;
2167 
2168 	mutex_lock(&bpf_event_mutex);
2169 
2170 	if (!event->prog)
2171 		goto unlock;
2172 
2173 	old_array = bpf_event_rcu_dereference(event->tp_event->prog_array);
2174 	ret = bpf_prog_array_copy(old_array, event->prog, NULL, 0, &new_array);
2175 	if (ret == -ENOENT)
2176 		goto unlock;
2177 	if (ret < 0) {
2178 		bpf_prog_array_delete_safe(old_array, event->prog);
2179 	} else {
2180 		rcu_assign_pointer(event->tp_event->prog_array, new_array);
2181 		bpf_prog_array_free_sleepable(old_array);
2182 	}
2183 
2184 	bpf_prog_put(event->prog);
2185 	event->prog = NULL;
2186 
2187 unlock:
2188 	mutex_unlock(&bpf_event_mutex);
2189 }
2190 
2191 int perf_event_query_prog_array(struct perf_event *event, void __user *info)
2192 {
2193 	struct perf_event_query_bpf __user *uquery = info;
2194 	struct perf_event_query_bpf query = {};
2195 	struct bpf_prog_array *progs;
2196 	u32 *ids, prog_cnt, ids_len;
2197 	int ret;
2198 
2199 	if (!perfmon_capable())
2200 		return -EPERM;
2201 	if (event->attr.type != PERF_TYPE_TRACEPOINT)
2202 		return -EINVAL;
2203 	if (copy_from_user(&query, uquery, sizeof(query)))
2204 		return -EFAULT;
2205 
2206 	ids_len = query.ids_len;
2207 	if (ids_len > BPF_TRACE_MAX_PROGS)
2208 		return -E2BIG;
2209 	ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN);
2210 	if (!ids)
2211 		return -ENOMEM;
2212 	/*
2213 	 * The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which
2214 	 * is required when user only wants to check for uquery->prog_cnt.
2215 	 * There is no need to check for it since the case is handled
2216 	 * gracefully in bpf_prog_array_copy_info.
2217 	 */
2218 
2219 	mutex_lock(&bpf_event_mutex);
2220 	progs = bpf_event_rcu_dereference(event->tp_event->prog_array);
2221 	ret = bpf_prog_array_copy_info(progs, ids, ids_len, &prog_cnt);
2222 	mutex_unlock(&bpf_event_mutex);
2223 
2224 	if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) ||
2225 	    copy_to_user(uquery->ids, ids, ids_len * sizeof(u32)))
2226 		ret = -EFAULT;
2227 
2228 	kfree(ids);
2229 	return ret;
2230 }
2231 
2232 extern struct bpf_raw_event_map __start__bpf_raw_tp[];
2233 extern struct bpf_raw_event_map __stop__bpf_raw_tp[];
2234 
2235 struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name)
2236 {
2237 	struct bpf_raw_event_map *btp = __start__bpf_raw_tp;
2238 
2239 	for (; btp < __stop__bpf_raw_tp; btp++) {
2240 		if (!strcmp(btp->tp->name, name))
2241 			return btp;
2242 	}
2243 
2244 	return bpf_get_raw_tracepoint_module(name);
2245 }
2246 
2247 void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp)
2248 {
2249 	struct module *mod;
2250 
2251 	preempt_disable();
2252 	mod = __module_address((unsigned long)btp);
2253 	module_put(mod);
2254 	preempt_enable();
2255 }
2256 
2257 static __always_inline
2258 void __bpf_trace_run(struct bpf_prog *prog, u64 *args)
2259 {
2260 	cant_sleep();
2261 	if (unlikely(this_cpu_inc_return(*(prog->active)) != 1)) {
2262 		bpf_prog_inc_misses_counter(prog);
2263 		goto out;
2264 	}
2265 	rcu_read_lock();
2266 	(void) bpf_prog_run(prog, args);
2267 	rcu_read_unlock();
2268 out:
2269 	this_cpu_dec(*(prog->active));
2270 }
2271 
2272 #define UNPACK(...)			__VA_ARGS__
2273 #define REPEAT_1(FN, DL, X, ...)	FN(X)
2274 #define REPEAT_2(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__)
2275 #define REPEAT_3(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_2(FN, DL, __VA_ARGS__)
2276 #define REPEAT_4(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_3(FN, DL, __VA_ARGS__)
2277 #define REPEAT_5(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_4(FN, DL, __VA_ARGS__)
2278 #define REPEAT_6(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_5(FN, DL, __VA_ARGS__)
2279 #define REPEAT_7(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_6(FN, DL, __VA_ARGS__)
2280 #define REPEAT_8(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_7(FN, DL, __VA_ARGS__)
2281 #define REPEAT_9(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_8(FN, DL, __VA_ARGS__)
2282 #define REPEAT_10(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_9(FN, DL, __VA_ARGS__)
2283 #define REPEAT_11(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_10(FN, DL, __VA_ARGS__)
2284 #define REPEAT_12(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_11(FN, DL, __VA_ARGS__)
2285 #define REPEAT(X, FN, DL, ...)		REPEAT_##X(FN, DL, __VA_ARGS__)
2286 
2287 #define SARG(X)		u64 arg##X
2288 #define COPY(X)		args[X] = arg##X
2289 
2290 #define __DL_COM	(,)
2291 #define __DL_SEM	(;)
2292 
2293 #define __SEQ_0_11	0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11
2294 
2295 #define BPF_TRACE_DEFN_x(x)						\
2296 	void bpf_trace_run##x(struct bpf_prog *prog,			\
2297 			      REPEAT(x, SARG, __DL_COM, __SEQ_0_11))	\
2298 	{								\
2299 		u64 args[x];						\
2300 		REPEAT(x, COPY, __DL_SEM, __SEQ_0_11);			\
2301 		__bpf_trace_run(prog, args);				\
2302 	}								\
2303 	EXPORT_SYMBOL_GPL(bpf_trace_run##x)
2304 BPF_TRACE_DEFN_x(1);
2305 BPF_TRACE_DEFN_x(2);
2306 BPF_TRACE_DEFN_x(3);
2307 BPF_TRACE_DEFN_x(4);
2308 BPF_TRACE_DEFN_x(5);
2309 BPF_TRACE_DEFN_x(6);
2310 BPF_TRACE_DEFN_x(7);
2311 BPF_TRACE_DEFN_x(8);
2312 BPF_TRACE_DEFN_x(9);
2313 BPF_TRACE_DEFN_x(10);
2314 BPF_TRACE_DEFN_x(11);
2315 BPF_TRACE_DEFN_x(12);
2316 
2317 static int __bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog)
2318 {
2319 	struct tracepoint *tp = btp->tp;
2320 
2321 	/*
2322 	 * check that program doesn't access arguments beyond what's
2323 	 * available in this tracepoint
2324 	 */
2325 	if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64))
2326 		return -EINVAL;
2327 
2328 	if (prog->aux->max_tp_access > btp->writable_size)
2329 		return -EINVAL;
2330 
2331 	return tracepoint_probe_register_may_exist(tp, (void *)btp->bpf_func,
2332 						   prog);
2333 }
2334 
2335 int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog)
2336 {
2337 	return __bpf_probe_register(btp, prog);
2338 }
2339 
2340 int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_prog *prog)
2341 {
2342 	return tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, prog);
2343 }
2344 
2345 int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id,
2346 			    u32 *fd_type, const char **buf,
2347 			    u64 *probe_offset, u64 *probe_addr)
2348 {
2349 	bool is_tracepoint, is_syscall_tp;
2350 	struct bpf_prog *prog;
2351 	int flags, err = 0;
2352 
2353 	prog = event->prog;
2354 	if (!prog)
2355 		return -ENOENT;
2356 
2357 	/* not supporting BPF_PROG_TYPE_PERF_EVENT yet */
2358 	if (prog->type == BPF_PROG_TYPE_PERF_EVENT)
2359 		return -EOPNOTSUPP;
2360 
2361 	*prog_id = prog->aux->id;
2362 	flags = event->tp_event->flags;
2363 	is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT;
2364 	is_syscall_tp = is_syscall_trace_event(event->tp_event);
2365 
2366 	if (is_tracepoint || is_syscall_tp) {
2367 		*buf = is_tracepoint ? event->tp_event->tp->name
2368 				     : event->tp_event->name;
2369 		*fd_type = BPF_FD_TYPE_TRACEPOINT;
2370 		*probe_offset = 0x0;
2371 		*probe_addr = 0x0;
2372 	} else {
2373 		/* kprobe/uprobe */
2374 		err = -EOPNOTSUPP;
2375 #ifdef CONFIG_KPROBE_EVENTS
2376 		if (flags & TRACE_EVENT_FL_KPROBE)
2377 			err = bpf_get_kprobe_info(event, fd_type, buf,
2378 						  probe_offset, probe_addr,
2379 						  event->attr.type == PERF_TYPE_TRACEPOINT);
2380 #endif
2381 #ifdef CONFIG_UPROBE_EVENTS
2382 		if (flags & TRACE_EVENT_FL_UPROBE)
2383 			err = bpf_get_uprobe_info(event, fd_type, buf,
2384 						  probe_offset,
2385 						  event->attr.type == PERF_TYPE_TRACEPOINT);
2386 #endif
2387 	}
2388 
2389 	return err;
2390 }
2391 
2392 static int __init send_signal_irq_work_init(void)
2393 {
2394 	int cpu;
2395 	struct send_signal_irq_work *work;
2396 
2397 	for_each_possible_cpu(cpu) {
2398 		work = per_cpu_ptr(&send_signal_work, cpu);
2399 		init_irq_work(&work->irq_work, do_bpf_send_signal);
2400 	}
2401 	return 0;
2402 }
2403 
2404 subsys_initcall(send_signal_irq_work_init);
2405 
2406 #ifdef CONFIG_MODULES
2407 static int bpf_event_notify(struct notifier_block *nb, unsigned long op,
2408 			    void *module)
2409 {
2410 	struct bpf_trace_module *btm, *tmp;
2411 	struct module *mod = module;
2412 	int ret = 0;
2413 
2414 	if (mod->num_bpf_raw_events == 0 ||
2415 	    (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING))
2416 		goto out;
2417 
2418 	mutex_lock(&bpf_module_mutex);
2419 
2420 	switch (op) {
2421 	case MODULE_STATE_COMING:
2422 		btm = kzalloc(sizeof(*btm), GFP_KERNEL);
2423 		if (btm) {
2424 			btm->module = module;
2425 			list_add(&btm->list, &bpf_trace_modules);
2426 		} else {
2427 			ret = -ENOMEM;
2428 		}
2429 		break;
2430 	case MODULE_STATE_GOING:
2431 		list_for_each_entry_safe(btm, tmp, &bpf_trace_modules, list) {
2432 			if (btm->module == module) {
2433 				list_del(&btm->list);
2434 				kfree(btm);
2435 				break;
2436 			}
2437 		}
2438 		break;
2439 	}
2440 
2441 	mutex_unlock(&bpf_module_mutex);
2442 
2443 out:
2444 	return notifier_from_errno(ret);
2445 }
2446 
2447 static struct notifier_block bpf_module_nb = {
2448 	.notifier_call = bpf_event_notify,
2449 };
2450 
2451 static int __init bpf_event_init(void)
2452 {
2453 	register_module_notifier(&bpf_module_nb);
2454 	return 0;
2455 }
2456 
2457 fs_initcall(bpf_event_init);
2458 #endif /* CONFIG_MODULES */
2459 
2460 #ifdef CONFIG_FPROBE
2461 struct bpf_kprobe_multi_link {
2462 	struct bpf_link link;
2463 	struct fprobe fp;
2464 	unsigned long *addrs;
2465 	u64 *cookies;
2466 	u32 cnt;
2467 	u32 mods_cnt;
2468 	struct module **mods;
2469 };
2470 
2471 struct bpf_kprobe_multi_run_ctx {
2472 	struct bpf_run_ctx run_ctx;
2473 	struct bpf_kprobe_multi_link *link;
2474 	unsigned long entry_ip;
2475 };
2476 
2477 struct user_syms {
2478 	const char **syms;
2479 	char *buf;
2480 };
2481 
2482 static int copy_user_syms(struct user_syms *us, unsigned long __user *usyms, u32 cnt)
2483 {
2484 	unsigned long __user usymbol;
2485 	const char **syms = NULL;
2486 	char *buf = NULL, *p;
2487 	int err = -ENOMEM;
2488 	unsigned int i;
2489 
2490 	syms = kvmalloc_array(cnt, sizeof(*syms), GFP_KERNEL);
2491 	if (!syms)
2492 		goto error;
2493 
2494 	buf = kvmalloc_array(cnt, KSYM_NAME_LEN, GFP_KERNEL);
2495 	if (!buf)
2496 		goto error;
2497 
2498 	for (p = buf, i = 0; i < cnt; i++) {
2499 		if (__get_user(usymbol, usyms + i)) {
2500 			err = -EFAULT;
2501 			goto error;
2502 		}
2503 		err = strncpy_from_user(p, (const char __user *) usymbol, KSYM_NAME_LEN);
2504 		if (err == KSYM_NAME_LEN)
2505 			err = -E2BIG;
2506 		if (err < 0)
2507 			goto error;
2508 		syms[i] = p;
2509 		p += err + 1;
2510 	}
2511 
2512 	us->syms = syms;
2513 	us->buf = buf;
2514 	return 0;
2515 
2516 error:
2517 	if (err) {
2518 		kvfree(syms);
2519 		kvfree(buf);
2520 	}
2521 	return err;
2522 }
2523 
2524 static void kprobe_multi_put_modules(struct module **mods, u32 cnt)
2525 {
2526 	u32 i;
2527 
2528 	for (i = 0; i < cnt; i++)
2529 		module_put(mods[i]);
2530 }
2531 
2532 static void free_user_syms(struct user_syms *us)
2533 {
2534 	kvfree(us->syms);
2535 	kvfree(us->buf);
2536 }
2537 
2538 static void bpf_kprobe_multi_link_release(struct bpf_link *link)
2539 {
2540 	struct bpf_kprobe_multi_link *kmulti_link;
2541 
2542 	kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);
2543 	unregister_fprobe(&kmulti_link->fp);
2544 	kprobe_multi_put_modules(kmulti_link->mods, kmulti_link->mods_cnt);
2545 }
2546 
2547 static void bpf_kprobe_multi_link_dealloc(struct bpf_link *link)
2548 {
2549 	struct bpf_kprobe_multi_link *kmulti_link;
2550 
2551 	kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);
2552 	kvfree(kmulti_link->addrs);
2553 	kvfree(kmulti_link->cookies);
2554 	kfree(kmulti_link->mods);
2555 	kfree(kmulti_link);
2556 }
2557 
2558 static const struct bpf_link_ops bpf_kprobe_multi_link_lops = {
2559 	.release = bpf_kprobe_multi_link_release,
2560 	.dealloc = bpf_kprobe_multi_link_dealloc,
2561 };
2562 
2563 static void bpf_kprobe_multi_cookie_swap(void *a, void *b, int size, const void *priv)
2564 {
2565 	const struct bpf_kprobe_multi_link *link = priv;
2566 	unsigned long *addr_a = a, *addr_b = b;
2567 	u64 *cookie_a, *cookie_b;
2568 
2569 	cookie_a = link->cookies + (addr_a - link->addrs);
2570 	cookie_b = link->cookies + (addr_b - link->addrs);
2571 
2572 	/* swap addr_a/addr_b and cookie_a/cookie_b values */
2573 	swap(*addr_a, *addr_b);
2574 	swap(*cookie_a, *cookie_b);
2575 }
2576 
2577 static int bpf_kprobe_multi_addrs_cmp(const void *a, const void *b)
2578 {
2579 	const unsigned long *addr_a = a, *addr_b = b;
2580 
2581 	if (*addr_a == *addr_b)
2582 		return 0;
2583 	return *addr_a < *addr_b ? -1 : 1;
2584 }
2585 
2586 static int bpf_kprobe_multi_cookie_cmp(const void *a, const void *b, const void *priv)
2587 {
2588 	return bpf_kprobe_multi_addrs_cmp(a, b);
2589 }
2590 
2591 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx)
2592 {
2593 	struct bpf_kprobe_multi_run_ctx *run_ctx;
2594 	struct bpf_kprobe_multi_link *link;
2595 	u64 *cookie, entry_ip;
2596 	unsigned long *addr;
2597 
2598 	if (WARN_ON_ONCE(!ctx))
2599 		return 0;
2600 	run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, run_ctx);
2601 	link = run_ctx->link;
2602 	if (!link->cookies)
2603 		return 0;
2604 	entry_ip = run_ctx->entry_ip;
2605 	addr = bsearch(&entry_ip, link->addrs, link->cnt, sizeof(entry_ip),
2606 		       bpf_kprobe_multi_addrs_cmp);
2607 	if (!addr)
2608 		return 0;
2609 	cookie = link->cookies + (addr - link->addrs);
2610 	return *cookie;
2611 }
2612 
2613 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
2614 {
2615 	struct bpf_kprobe_multi_run_ctx *run_ctx;
2616 
2617 	run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, run_ctx);
2618 	return run_ctx->entry_ip;
2619 }
2620 
2621 static int
2622 kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link,
2623 			   unsigned long entry_ip, struct pt_regs *regs)
2624 {
2625 	struct bpf_kprobe_multi_run_ctx run_ctx = {
2626 		.link = link,
2627 		.entry_ip = entry_ip,
2628 	};
2629 	struct bpf_run_ctx *old_run_ctx;
2630 	int err;
2631 
2632 	if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) {
2633 		err = 0;
2634 		goto out;
2635 	}
2636 
2637 	migrate_disable();
2638 	rcu_read_lock();
2639 	old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx);
2640 	err = bpf_prog_run(link->link.prog, regs);
2641 	bpf_reset_run_ctx(old_run_ctx);
2642 	rcu_read_unlock();
2643 	migrate_enable();
2644 
2645  out:
2646 	__this_cpu_dec(bpf_prog_active);
2647 	return err;
2648 }
2649 
2650 static void
2651 kprobe_multi_link_handler(struct fprobe *fp, unsigned long fentry_ip,
2652 			  struct pt_regs *regs)
2653 {
2654 	struct bpf_kprobe_multi_link *link;
2655 
2656 	link = container_of(fp, struct bpf_kprobe_multi_link, fp);
2657 	kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), regs);
2658 }
2659 
2660 static int symbols_cmp_r(const void *a, const void *b, const void *priv)
2661 {
2662 	const char **str_a = (const char **) a;
2663 	const char **str_b = (const char **) b;
2664 
2665 	return strcmp(*str_a, *str_b);
2666 }
2667 
2668 struct multi_symbols_sort {
2669 	const char **funcs;
2670 	u64 *cookies;
2671 };
2672 
2673 static void symbols_swap_r(void *a, void *b, int size, const void *priv)
2674 {
2675 	const struct multi_symbols_sort *data = priv;
2676 	const char **name_a = a, **name_b = b;
2677 
2678 	swap(*name_a, *name_b);
2679 
2680 	/* If defined, swap also related cookies. */
2681 	if (data->cookies) {
2682 		u64 *cookie_a, *cookie_b;
2683 
2684 		cookie_a = data->cookies + (name_a - data->funcs);
2685 		cookie_b = data->cookies + (name_b - data->funcs);
2686 		swap(*cookie_a, *cookie_b);
2687 	}
2688 }
2689 
2690 struct module_addr_args {
2691 	unsigned long *addrs;
2692 	u32 addrs_cnt;
2693 	struct module **mods;
2694 	int mods_cnt;
2695 	int mods_cap;
2696 };
2697 
2698 static int module_callback(void *data, const char *name,
2699 			   struct module *mod, unsigned long addr)
2700 {
2701 	struct module_addr_args *args = data;
2702 	struct module **mods;
2703 
2704 	/* We iterate all modules symbols and for each we:
2705 	 * - search for it in provided addresses array
2706 	 * - if found we check if we already have the module pointer stored
2707 	 *   (we iterate modules sequentially, so we can check just the last
2708 	 *   module pointer)
2709 	 * - take module reference and store it
2710 	 */
2711 	if (!bsearch(&addr, args->addrs, args->addrs_cnt, sizeof(addr),
2712 		       bpf_kprobe_multi_addrs_cmp))
2713 		return 0;
2714 
2715 	if (args->mods && args->mods[args->mods_cnt - 1] == mod)
2716 		return 0;
2717 
2718 	if (args->mods_cnt == args->mods_cap) {
2719 		args->mods_cap = max(16, args->mods_cap * 3 / 2);
2720 		mods = krealloc_array(args->mods, args->mods_cap, sizeof(*mods), GFP_KERNEL);
2721 		if (!mods)
2722 			return -ENOMEM;
2723 		args->mods = mods;
2724 	}
2725 
2726 	if (!try_module_get(mod))
2727 		return -EINVAL;
2728 
2729 	args->mods[args->mods_cnt] = mod;
2730 	args->mods_cnt++;
2731 	return 0;
2732 }
2733 
2734 static int get_modules_for_addrs(struct module ***mods, unsigned long *addrs, u32 addrs_cnt)
2735 {
2736 	struct module_addr_args args = {
2737 		.addrs     = addrs,
2738 		.addrs_cnt = addrs_cnt,
2739 	};
2740 	int err;
2741 
2742 	/* We return either err < 0 in case of error, ... */
2743 	err = module_kallsyms_on_each_symbol(module_callback, &args);
2744 	if (err) {
2745 		kprobe_multi_put_modules(args.mods, args.mods_cnt);
2746 		kfree(args.mods);
2747 		return err;
2748 	}
2749 
2750 	/* or number of modules found if everything is ok. */
2751 	*mods = args.mods;
2752 	return args.mods_cnt;
2753 }
2754 
2755 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
2756 {
2757 	struct bpf_kprobe_multi_link *link = NULL;
2758 	struct bpf_link_primer link_primer;
2759 	void __user *ucookies;
2760 	unsigned long *addrs;
2761 	u32 flags, cnt, size;
2762 	void __user *uaddrs;
2763 	u64 *cookies = NULL;
2764 	void __user *usyms;
2765 	int err;
2766 
2767 	/* no support for 32bit archs yet */
2768 	if (sizeof(u64) != sizeof(void *))
2769 		return -EOPNOTSUPP;
2770 
2771 	if (prog->expected_attach_type != BPF_TRACE_KPROBE_MULTI)
2772 		return -EINVAL;
2773 
2774 	flags = attr->link_create.kprobe_multi.flags;
2775 	if (flags & ~BPF_F_KPROBE_MULTI_RETURN)
2776 		return -EINVAL;
2777 
2778 	uaddrs = u64_to_user_ptr(attr->link_create.kprobe_multi.addrs);
2779 	usyms = u64_to_user_ptr(attr->link_create.kprobe_multi.syms);
2780 	if (!!uaddrs == !!usyms)
2781 		return -EINVAL;
2782 
2783 	cnt = attr->link_create.kprobe_multi.cnt;
2784 	if (!cnt)
2785 		return -EINVAL;
2786 
2787 	size = cnt * sizeof(*addrs);
2788 	addrs = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL);
2789 	if (!addrs)
2790 		return -ENOMEM;
2791 
2792 	ucookies = u64_to_user_ptr(attr->link_create.kprobe_multi.cookies);
2793 	if (ucookies) {
2794 		cookies = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL);
2795 		if (!cookies) {
2796 			err = -ENOMEM;
2797 			goto error;
2798 		}
2799 		if (copy_from_user(cookies, ucookies, size)) {
2800 			err = -EFAULT;
2801 			goto error;
2802 		}
2803 	}
2804 
2805 	if (uaddrs) {
2806 		if (copy_from_user(addrs, uaddrs, size)) {
2807 			err = -EFAULT;
2808 			goto error;
2809 		}
2810 	} else {
2811 		struct multi_symbols_sort data = {
2812 			.cookies = cookies,
2813 		};
2814 		struct user_syms us;
2815 
2816 		err = copy_user_syms(&us, usyms, cnt);
2817 		if (err)
2818 			goto error;
2819 
2820 		if (cookies)
2821 			data.funcs = us.syms;
2822 
2823 		sort_r(us.syms, cnt, sizeof(*us.syms), symbols_cmp_r,
2824 		       symbols_swap_r, &data);
2825 
2826 		err = ftrace_lookup_symbols(us.syms, cnt, addrs);
2827 		free_user_syms(&us);
2828 		if (err)
2829 			goto error;
2830 	}
2831 
2832 	link = kzalloc(sizeof(*link), GFP_KERNEL);
2833 	if (!link) {
2834 		err = -ENOMEM;
2835 		goto error;
2836 	}
2837 
2838 	bpf_link_init(&link->link, BPF_LINK_TYPE_KPROBE_MULTI,
2839 		      &bpf_kprobe_multi_link_lops, prog);
2840 
2841 	err = bpf_link_prime(&link->link, &link_primer);
2842 	if (err)
2843 		goto error;
2844 
2845 	if (flags & BPF_F_KPROBE_MULTI_RETURN)
2846 		link->fp.exit_handler = kprobe_multi_link_handler;
2847 	else
2848 		link->fp.entry_handler = kprobe_multi_link_handler;
2849 
2850 	link->addrs = addrs;
2851 	link->cookies = cookies;
2852 	link->cnt = cnt;
2853 
2854 	if (cookies) {
2855 		/*
2856 		 * Sorting addresses will trigger sorting cookies as well
2857 		 * (check bpf_kprobe_multi_cookie_swap). This way we can
2858 		 * find cookie based on the address in bpf_get_attach_cookie
2859 		 * helper.
2860 		 */
2861 		sort_r(addrs, cnt, sizeof(*addrs),
2862 		       bpf_kprobe_multi_cookie_cmp,
2863 		       bpf_kprobe_multi_cookie_swap,
2864 		       link);
2865 	} else {
2866 		/*
2867 		 * We need to sort addrs array even if there are no cookies
2868 		 * provided, to allow bsearch in get_modules_for_addrs.
2869 		 */
2870 		sort(addrs, cnt, sizeof(*addrs),
2871 		       bpf_kprobe_multi_addrs_cmp, NULL);
2872 	}
2873 
2874 	err = get_modules_for_addrs(&link->mods, addrs, cnt);
2875 	if (err < 0) {
2876 		bpf_link_cleanup(&link_primer);
2877 		return err;
2878 	}
2879 	link->mods_cnt = err;
2880 
2881 	err = register_fprobe_ips(&link->fp, addrs, cnt);
2882 	if (err) {
2883 		kprobe_multi_put_modules(link->mods, link->mods_cnt);
2884 		bpf_link_cleanup(&link_primer);
2885 		return err;
2886 	}
2887 
2888 	return bpf_link_settle(&link_primer);
2889 
2890 error:
2891 	kfree(link);
2892 	kvfree(addrs);
2893 	kvfree(cookies);
2894 	return err;
2895 }
2896 #else /* !CONFIG_FPROBE */
2897 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
2898 {
2899 	return -EOPNOTSUPP;
2900 }
2901 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx)
2902 {
2903 	return 0;
2904 }
2905 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
2906 {
2907 	return 0;
2908 }
2909 #endif
2910