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