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1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2011-2015 PLUMgrid, http://plumgrid.com
3  * Copyright (c) 2016 Facebook
4  */
5 #include <linux/kernel.h>
6 #include <linux/types.h>
7 #include <linux/slab.h>
8 #include <linux/bpf.h>
9 #include <linux/bpf_verifier.h>
10 #include <linux/bpf_perf_event.h>
11 #include <linux/btf.h>
12 #include <linux/filter.h>
13 #include <linux/uaccess.h>
14 #include <linux/ctype.h>
15 #include <linux/kprobes.h>
16 #include <linux/spinlock.h>
17 #include <linux/syscalls.h>
18 #include <linux/error-injection.h>
19 #include <linux/btf_ids.h>
20 #include <linux/bpf_lsm.h>
21 #include <linux/fprobe.h>
22 #include <linux/bsearch.h>
23 #include <linux/sort.h>
24 #include <linux/key.h>
25 #include <linux/verification.h>
26 #include <linux/namei.h>
27 
28 #include <net/bpf_sk_storage.h>
29 
30 #include <uapi/linux/bpf.h>
31 #include <uapi/linux/btf.h>
32 
33 #include <asm/tlb.h>
34 
35 #include "trace_probe.h"
36 #include "trace.h"
37 
38 #define CREATE_TRACE_POINTS
39 #include "bpf_trace.h"
40 
41 #define bpf_event_rcu_dereference(p)					\
42 	rcu_dereference_protected(p, lockdep_is_held(&bpf_event_mutex))
43 
44 #define MAX_UPROBE_MULTI_CNT (1U << 20)
45 #define MAX_KPROBE_MULTI_CNT (1U << 20)
46 
47 #ifdef CONFIG_MODULES
48 struct bpf_trace_module {
49 	struct module *module;
50 	struct list_head list;
51 };
52 
53 static LIST_HEAD(bpf_trace_modules);
54 static DEFINE_MUTEX(bpf_module_mutex);
55 
bpf_get_raw_tracepoint_module(const char * name)56 static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name)
57 {
58 	struct bpf_raw_event_map *btp, *ret = NULL;
59 	struct bpf_trace_module *btm;
60 	unsigned int i;
61 
62 	mutex_lock(&bpf_module_mutex);
63 	list_for_each_entry(btm, &bpf_trace_modules, list) {
64 		for (i = 0; i < btm->module->num_bpf_raw_events; ++i) {
65 			btp = &btm->module->bpf_raw_events[i];
66 			if (!strcmp(btp->tp->name, name)) {
67 				if (try_module_get(btm->module))
68 					ret = btp;
69 				goto out;
70 			}
71 		}
72 	}
73 out:
74 	mutex_unlock(&bpf_module_mutex);
75 	return ret;
76 }
77 #else
bpf_get_raw_tracepoint_module(const char * name)78 static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name)
79 {
80 	return NULL;
81 }
82 #endif /* CONFIG_MODULES */
83 
84 u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
85 u64 bpf_get_stack(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
86 
87 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size,
88 				  u64 flags, const struct btf **btf,
89 				  s32 *btf_id);
90 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx);
91 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx);
92 
93 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx);
94 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx);
95 
96 /**
97  * trace_call_bpf - invoke BPF program
98  * @call: tracepoint event
99  * @ctx: opaque context pointer
100  *
101  * kprobe handlers execute BPF programs via this helper.
102  * Can be used from static tracepoints in the future.
103  *
104  * Return: BPF programs always return an integer which is interpreted by
105  * kprobe handler as:
106  * 0 - return from kprobe (event is filtered out)
107  * 1 - store kprobe event into ring buffer
108  * Other values are reserved and currently alias to 1
109  */
trace_call_bpf(struct trace_event_call * call,void * ctx)110 unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx)
111 {
112 	unsigned int ret;
113 
114 	cant_sleep();
115 
116 	if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) {
117 		/*
118 		 * since some bpf program is already running on this cpu,
119 		 * don't call into another bpf program (same or different)
120 		 * and don't send kprobe event into ring-buffer,
121 		 * so return zero here
122 		 */
123 		ret = 0;
124 		goto out;
125 	}
126 
127 	/*
128 	 * Instead of moving rcu_read_lock/rcu_dereference/rcu_read_unlock
129 	 * to all call sites, we did a bpf_prog_array_valid() there to check
130 	 * whether call->prog_array is empty or not, which is
131 	 * a heuristic to speed up execution.
132 	 *
133 	 * If bpf_prog_array_valid() fetched prog_array was
134 	 * non-NULL, we go into trace_call_bpf() and do the actual
135 	 * proper rcu_dereference() under RCU lock.
136 	 * If it turns out that prog_array is NULL then, we bail out.
137 	 * For the opposite, if the bpf_prog_array_valid() fetched pointer
138 	 * was NULL, you'll skip the prog_array with the risk of missing
139 	 * out of events when it was updated in between this and the
140 	 * rcu_dereference() which is accepted risk.
141 	 */
142 	rcu_read_lock();
143 	ret = bpf_prog_run_array(rcu_dereference(call->prog_array),
144 				 ctx, bpf_prog_run);
145 	rcu_read_unlock();
146 
147  out:
148 	__this_cpu_dec(bpf_prog_active);
149 
150 	return ret;
151 }
152 
153 #ifdef CONFIG_BPF_KPROBE_OVERRIDE
BPF_CALL_2(bpf_override_return,struct pt_regs *,regs,unsigned long,rc)154 BPF_CALL_2(bpf_override_return, struct pt_regs *, regs, unsigned long, rc)
155 {
156 	regs_set_return_value(regs, rc);
157 	override_function_with_return(regs);
158 	return 0;
159 }
160 
161 static const struct bpf_func_proto bpf_override_return_proto = {
162 	.func		= bpf_override_return,
163 	.gpl_only	= true,
164 	.ret_type	= RET_INTEGER,
165 	.arg1_type	= ARG_PTR_TO_CTX,
166 	.arg2_type	= ARG_ANYTHING,
167 };
168 #endif
169 
170 static __always_inline int
bpf_probe_read_user_common(void * dst,u32 size,const void __user * unsafe_ptr)171 bpf_probe_read_user_common(void *dst, u32 size, const void __user *unsafe_ptr)
172 {
173 	int ret;
174 
175 	ret = copy_from_user_nofault(dst, unsafe_ptr, size);
176 	if (unlikely(ret < 0))
177 		memset(dst, 0, size);
178 	return ret;
179 }
180 
BPF_CALL_3(bpf_probe_read_user,void *,dst,u32,size,const void __user *,unsafe_ptr)181 BPF_CALL_3(bpf_probe_read_user, void *, dst, u32, size,
182 	   const void __user *, unsafe_ptr)
183 {
184 	return bpf_probe_read_user_common(dst, size, unsafe_ptr);
185 }
186 
187 const struct bpf_func_proto bpf_probe_read_user_proto = {
188 	.func		= bpf_probe_read_user,
189 	.gpl_only	= true,
190 	.ret_type	= RET_INTEGER,
191 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
192 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
193 	.arg3_type	= ARG_ANYTHING,
194 };
195 
196 static __always_inline int
bpf_probe_read_user_str_common(void * dst,u32 size,const void __user * unsafe_ptr)197 bpf_probe_read_user_str_common(void *dst, u32 size,
198 			       const void __user *unsafe_ptr)
199 {
200 	int ret;
201 
202 	/*
203 	 * NB: We rely on strncpy_from_user() not copying junk past the NUL
204 	 * terminator into `dst`.
205 	 *
206 	 * strncpy_from_user() does long-sized strides in the fast path. If the
207 	 * strncpy does not mask out the bytes after the NUL in `unsafe_ptr`,
208 	 * then there could be junk after the NUL in `dst`. If user takes `dst`
209 	 * and keys a hash map with it, then semantically identical strings can
210 	 * occupy multiple entries in the map.
211 	 */
212 	ret = strncpy_from_user_nofault(dst, unsafe_ptr, size);
213 	if (unlikely(ret < 0))
214 		memset(dst, 0, size);
215 	return ret;
216 }
217 
BPF_CALL_3(bpf_probe_read_user_str,void *,dst,u32,size,const void __user *,unsafe_ptr)218 BPF_CALL_3(bpf_probe_read_user_str, void *, dst, u32, size,
219 	   const void __user *, unsafe_ptr)
220 {
221 	return bpf_probe_read_user_str_common(dst, size, unsafe_ptr);
222 }
223 
224 const struct bpf_func_proto bpf_probe_read_user_str_proto = {
225 	.func		= bpf_probe_read_user_str,
226 	.gpl_only	= true,
227 	.ret_type	= RET_INTEGER,
228 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
229 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
230 	.arg3_type	= ARG_ANYTHING,
231 };
232 
BPF_CALL_3(bpf_probe_read_kernel,void *,dst,u32,size,const void *,unsafe_ptr)233 BPF_CALL_3(bpf_probe_read_kernel, void *, dst, u32, size,
234 	   const void *, unsafe_ptr)
235 {
236 	return bpf_probe_read_kernel_common(dst, size, unsafe_ptr);
237 }
238 
239 const struct bpf_func_proto bpf_probe_read_kernel_proto = {
240 	.func		= bpf_probe_read_kernel,
241 	.gpl_only	= true,
242 	.ret_type	= RET_INTEGER,
243 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
244 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
245 	.arg3_type	= ARG_ANYTHING,
246 };
247 
248 static __always_inline int
bpf_probe_read_kernel_str_common(void * dst,u32 size,const void * unsafe_ptr)249 bpf_probe_read_kernel_str_common(void *dst, u32 size, const void *unsafe_ptr)
250 {
251 	int ret;
252 
253 	/*
254 	 * The strncpy_from_kernel_nofault() call will likely not fill the
255 	 * entire buffer, but that's okay in this circumstance as we're probing
256 	 * arbitrary memory anyway similar to bpf_probe_read_*() and might
257 	 * as well probe the stack. Thus, memory is explicitly cleared
258 	 * only in error case, so that improper users ignoring return
259 	 * code altogether don't copy garbage; otherwise length of string
260 	 * is returned that can be used for bpf_perf_event_output() et al.
261 	 */
262 	ret = strncpy_from_kernel_nofault(dst, unsafe_ptr, size);
263 	if (unlikely(ret < 0))
264 		memset(dst, 0, size);
265 	return ret;
266 }
267 
BPF_CALL_3(bpf_probe_read_kernel_str,void *,dst,u32,size,const void *,unsafe_ptr)268 BPF_CALL_3(bpf_probe_read_kernel_str, void *, dst, u32, size,
269 	   const void *, unsafe_ptr)
270 {
271 	return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr);
272 }
273 
274 const struct bpf_func_proto bpf_probe_read_kernel_str_proto = {
275 	.func		= bpf_probe_read_kernel_str,
276 	.gpl_only	= true,
277 	.ret_type	= RET_INTEGER,
278 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
279 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
280 	.arg3_type	= ARG_ANYTHING,
281 };
282 
283 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
BPF_CALL_3(bpf_probe_read_compat,void *,dst,u32,size,const void *,unsafe_ptr)284 BPF_CALL_3(bpf_probe_read_compat, void *, dst, u32, size,
285 	   const void *, unsafe_ptr)
286 {
287 	if ((unsigned long)unsafe_ptr < TASK_SIZE) {
288 		return bpf_probe_read_user_common(dst, size,
289 				(__force void __user *)unsafe_ptr);
290 	}
291 	return bpf_probe_read_kernel_common(dst, size, unsafe_ptr);
292 }
293 
294 static const struct bpf_func_proto bpf_probe_read_compat_proto = {
295 	.func		= bpf_probe_read_compat,
296 	.gpl_only	= true,
297 	.ret_type	= RET_INTEGER,
298 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
299 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
300 	.arg3_type	= ARG_ANYTHING,
301 };
302 
BPF_CALL_3(bpf_probe_read_compat_str,void *,dst,u32,size,const void *,unsafe_ptr)303 BPF_CALL_3(bpf_probe_read_compat_str, void *, dst, u32, size,
304 	   const void *, unsafe_ptr)
305 {
306 	if ((unsigned long)unsafe_ptr < TASK_SIZE) {
307 		return bpf_probe_read_user_str_common(dst, size,
308 				(__force void __user *)unsafe_ptr);
309 	}
310 	return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr);
311 }
312 
313 static const struct bpf_func_proto bpf_probe_read_compat_str_proto = {
314 	.func		= bpf_probe_read_compat_str,
315 	.gpl_only	= true,
316 	.ret_type	= RET_INTEGER,
317 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
318 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
319 	.arg3_type	= ARG_ANYTHING,
320 };
321 #endif /* CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE */
322 
BPF_CALL_3(bpf_probe_write_user,void __user *,unsafe_ptr,const void *,src,u32,size)323 BPF_CALL_3(bpf_probe_write_user, void __user *, unsafe_ptr, const void *, src,
324 	   u32, size)
325 {
326 	/*
327 	 * Ensure we're in user context which is safe for the helper to
328 	 * run. This helper has no business in a kthread.
329 	 *
330 	 * access_ok() should prevent writing to non-user memory, but in
331 	 * some situations (nommu, temporary switch, etc) access_ok() does
332 	 * not provide enough validation, hence the check on KERNEL_DS.
333 	 *
334 	 * nmi_uaccess_okay() ensures the probe is not run in an interim
335 	 * state, when the task or mm are switched. This is specifically
336 	 * required to prevent the use of temporary mm.
337 	 */
338 
339 	if (unlikely(in_interrupt() ||
340 		     current->flags & (PF_KTHREAD | PF_EXITING)))
341 		return -EPERM;
342 	if (unlikely(!nmi_uaccess_okay()))
343 		return -EPERM;
344 
345 	return copy_to_user_nofault(unsafe_ptr, src, size);
346 }
347 
348 static const struct bpf_func_proto bpf_probe_write_user_proto = {
349 	.func		= bpf_probe_write_user,
350 	.gpl_only	= true,
351 	.ret_type	= RET_INTEGER,
352 	.arg1_type	= ARG_ANYTHING,
353 	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
354 	.arg3_type	= ARG_CONST_SIZE,
355 };
356 
bpf_get_probe_write_proto(void)357 static const struct bpf_func_proto *bpf_get_probe_write_proto(void)
358 {
359 	if (!capable(CAP_SYS_ADMIN))
360 		return NULL;
361 
362 	pr_warn_ratelimited("%s[%d] is installing a program with bpf_probe_write_user helper that may corrupt user memory!",
363 			    current->comm, task_pid_nr(current));
364 
365 	return &bpf_probe_write_user_proto;
366 }
367 
368 #define MAX_TRACE_PRINTK_VARARGS	3
369 #define BPF_TRACE_PRINTK_SIZE		1024
370 
BPF_CALL_5(bpf_trace_printk,char *,fmt,u32,fmt_size,u64,arg1,u64,arg2,u64,arg3)371 BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1,
372 	   u64, arg2, u64, arg3)
373 {
374 	u64 args[MAX_TRACE_PRINTK_VARARGS] = { arg1, arg2, arg3 };
375 	struct bpf_bprintf_data data = {
376 		.get_bin_args	= true,
377 		.get_buf	= true,
378 	};
379 	int ret;
380 
381 	ret = bpf_bprintf_prepare(fmt, fmt_size, args,
382 				  MAX_TRACE_PRINTK_VARARGS, &data);
383 	if (ret < 0)
384 		return ret;
385 
386 	ret = bstr_printf(data.buf, MAX_BPRINTF_BUF, fmt, data.bin_args);
387 
388 	trace_bpf_trace_printk(data.buf);
389 
390 	bpf_bprintf_cleanup(&data);
391 
392 	return ret;
393 }
394 
395 static const struct bpf_func_proto bpf_trace_printk_proto = {
396 	.func		= bpf_trace_printk,
397 	.gpl_only	= true,
398 	.ret_type	= RET_INTEGER,
399 	.arg1_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
400 	.arg2_type	= ARG_CONST_SIZE,
401 };
402 
__set_printk_clr_event(void)403 static void __set_printk_clr_event(void)
404 {
405 	/*
406 	 * This program might be calling bpf_trace_printk,
407 	 * so enable the associated bpf_trace/bpf_trace_printk event.
408 	 * Repeat this each time as it is possible a user has
409 	 * disabled bpf_trace_printk events.  By loading a program
410 	 * calling bpf_trace_printk() however the user has expressed
411 	 * the intent to see such events.
412 	 */
413 	if (trace_set_clr_event("bpf_trace", "bpf_trace_printk", 1))
414 		pr_warn_ratelimited("could not enable bpf_trace_printk events");
415 }
416 
bpf_get_trace_printk_proto(void)417 const struct bpf_func_proto *bpf_get_trace_printk_proto(void)
418 {
419 	__set_printk_clr_event();
420 	return &bpf_trace_printk_proto;
421 }
422 
BPF_CALL_4(bpf_trace_vprintk,char *,fmt,u32,fmt_size,const void *,args,u32,data_len)423 BPF_CALL_4(bpf_trace_vprintk, char *, fmt, u32, fmt_size, const void *, args,
424 	   u32, data_len)
425 {
426 	struct bpf_bprintf_data data = {
427 		.get_bin_args	= true,
428 		.get_buf	= true,
429 	};
430 	int ret, num_args;
431 
432 	if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 ||
433 	    (data_len && !args))
434 		return -EINVAL;
435 	num_args = data_len / 8;
436 
437 	ret = bpf_bprintf_prepare(fmt, fmt_size, args, num_args, &data);
438 	if (ret < 0)
439 		return ret;
440 
441 	ret = bstr_printf(data.buf, MAX_BPRINTF_BUF, fmt, data.bin_args);
442 
443 	trace_bpf_trace_printk(data.buf);
444 
445 	bpf_bprintf_cleanup(&data);
446 
447 	return ret;
448 }
449 
450 static const struct bpf_func_proto bpf_trace_vprintk_proto = {
451 	.func		= bpf_trace_vprintk,
452 	.gpl_only	= true,
453 	.ret_type	= RET_INTEGER,
454 	.arg1_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
455 	.arg2_type	= ARG_CONST_SIZE,
456 	.arg3_type	= ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY,
457 	.arg4_type	= ARG_CONST_SIZE_OR_ZERO,
458 };
459 
bpf_get_trace_vprintk_proto(void)460 const struct bpf_func_proto *bpf_get_trace_vprintk_proto(void)
461 {
462 	__set_printk_clr_event();
463 	return &bpf_trace_vprintk_proto;
464 }
465 
BPF_CALL_5(bpf_seq_printf,struct seq_file *,m,char *,fmt,u32,fmt_size,const void *,args,u32,data_len)466 BPF_CALL_5(bpf_seq_printf, struct seq_file *, m, char *, fmt, u32, fmt_size,
467 	   const void *, args, u32, data_len)
468 {
469 	struct bpf_bprintf_data data = {
470 		.get_bin_args	= true,
471 	};
472 	int err, num_args;
473 
474 	if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 ||
475 	    (data_len && !args))
476 		return -EINVAL;
477 	num_args = data_len / 8;
478 
479 	err = bpf_bprintf_prepare(fmt, fmt_size, args, num_args, &data);
480 	if (err < 0)
481 		return err;
482 
483 	seq_bprintf(m, fmt, data.bin_args);
484 
485 	bpf_bprintf_cleanup(&data);
486 
487 	return seq_has_overflowed(m) ? -EOVERFLOW : 0;
488 }
489 
490 BTF_ID_LIST_SINGLE(btf_seq_file_ids, struct, seq_file)
491 
492 static const struct bpf_func_proto bpf_seq_printf_proto = {
493 	.func		= bpf_seq_printf,
494 	.gpl_only	= true,
495 	.ret_type	= RET_INTEGER,
496 	.arg1_type	= ARG_PTR_TO_BTF_ID,
497 	.arg1_btf_id	= &btf_seq_file_ids[0],
498 	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
499 	.arg3_type	= ARG_CONST_SIZE,
500 	.arg4_type      = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY,
501 	.arg5_type      = ARG_CONST_SIZE_OR_ZERO,
502 };
503 
BPF_CALL_3(bpf_seq_write,struct seq_file *,m,const void *,data,u32,len)504 BPF_CALL_3(bpf_seq_write, struct seq_file *, m, const void *, data, u32, len)
505 {
506 	return seq_write(m, data, len) ? -EOVERFLOW : 0;
507 }
508 
509 static const struct bpf_func_proto bpf_seq_write_proto = {
510 	.func		= bpf_seq_write,
511 	.gpl_only	= true,
512 	.ret_type	= RET_INTEGER,
513 	.arg1_type	= ARG_PTR_TO_BTF_ID,
514 	.arg1_btf_id	= &btf_seq_file_ids[0],
515 	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
516 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
517 };
518 
BPF_CALL_4(bpf_seq_printf_btf,struct seq_file *,m,struct btf_ptr *,ptr,u32,btf_ptr_size,u64,flags)519 BPF_CALL_4(bpf_seq_printf_btf, struct seq_file *, m, struct btf_ptr *, ptr,
520 	   u32, btf_ptr_size, u64, flags)
521 {
522 	const struct btf *btf;
523 	s32 btf_id;
524 	int ret;
525 
526 	ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id);
527 	if (ret)
528 		return ret;
529 
530 	return btf_type_seq_show_flags(btf, btf_id, ptr->ptr, m, flags);
531 }
532 
533 static const struct bpf_func_proto bpf_seq_printf_btf_proto = {
534 	.func		= bpf_seq_printf_btf,
535 	.gpl_only	= true,
536 	.ret_type	= RET_INTEGER,
537 	.arg1_type	= ARG_PTR_TO_BTF_ID,
538 	.arg1_btf_id	= &btf_seq_file_ids[0],
539 	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
540 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
541 	.arg4_type	= ARG_ANYTHING,
542 };
543 
544 static __always_inline int
get_map_perf_counter(struct bpf_map * map,u64 flags,u64 * value,u64 * enabled,u64 * running)545 get_map_perf_counter(struct bpf_map *map, u64 flags,
546 		     u64 *value, u64 *enabled, u64 *running)
547 {
548 	struct bpf_array *array = container_of(map, struct bpf_array, map);
549 	unsigned int cpu = smp_processor_id();
550 	u64 index = flags & BPF_F_INDEX_MASK;
551 	struct bpf_event_entry *ee;
552 
553 	if (unlikely(flags & ~(BPF_F_INDEX_MASK)))
554 		return -EINVAL;
555 	if (index == BPF_F_CURRENT_CPU)
556 		index = cpu;
557 	if (unlikely(index >= array->map.max_entries))
558 		return -E2BIG;
559 
560 	ee = READ_ONCE(array->ptrs[index]);
561 	if (!ee)
562 		return -ENOENT;
563 
564 	return perf_event_read_local(ee->event, value, enabled, running);
565 }
566 
BPF_CALL_2(bpf_perf_event_read,struct bpf_map *,map,u64,flags)567 BPF_CALL_2(bpf_perf_event_read, struct bpf_map *, map, u64, flags)
568 {
569 	u64 value = 0;
570 	int err;
571 
572 	err = get_map_perf_counter(map, flags, &value, NULL, NULL);
573 	/*
574 	 * this api is ugly since we miss [-22..-2] range of valid
575 	 * counter values, but that's uapi
576 	 */
577 	if (err)
578 		return err;
579 	return value;
580 }
581 
582 static const struct bpf_func_proto bpf_perf_event_read_proto = {
583 	.func		= bpf_perf_event_read,
584 	.gpl_only	= true,
585 	.ret_type	= RET_INTEGER,
586 	.arg1_type	= ARG_CONST_MAP_PTR,
587 	.arg2_type	= ARG_ANYTHING,
588 };
589 
BPF_CALL_4(bpf_perf_event_read_value,struct bpf_map *,map,u64,flags,struct bpf_perf_event_value *,buf,u32,size)590 BPF_CALL_4(bpf_perf_event_read_value, struct bpf_map *, map, u64, flags,
591 	   struct bpf_perf_event_value *, buf, u32, size)
592 {
593 	int err = -EINVAL;
594 
595 	if (unlikely(size != sizeof(struct bpf_perf_event_value)))
596 		goto clear;
597 	err = get_map_perf_counter(map, flags, &buf->counter, &buf->enabled,
598 				   &buf->running);
599 	if (unlikely(err))
600 		goto clear;
601 	return 0;
602 clear:
603 	memset(buf, 0, size);
604 	return err;
605 }
606 
607 static const struct bpf_func_proto bpf_perf_event_read_value_proto = {
608 	.func		= bpf_perf_event_read_value,
609 	.gpl_only	= true,
610 	.ret_type	= RET_INTEGER,
611 	.arg1_type	= ARG_CONST_MAP_PTR,
612 	.arg2_type	= ARG_ANYTHING,
613 	.arg3_type	= ARG_PTR_TO_UNINIT_MEM,
614 	.arg4_type	= ARG_CONST_SIZE,
615 };
616 
617 static __always_inline u64
__bpf_perf_event_output(struct pt_regs * regs,struct bpf_map * map,u64 flags,struct perf_raw_record * raw,struct perf_sample_data * sd)618 __bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map,
619 			u64 flags, struct perf_raw_record *raw,
620 			struct perf_sample_data *sd)
621 {
622 	struct bpf_array *array = container_of(map, struct bpf_array, map);
623 	unsigned int cpu = smp_processor_id();
624 	u64 index = flags & BPF_F_INDEX_MASK;
625 	struct bpf_event_entry *ee;
626 	struct perf_event *event;
627 
628 	if (index == BPF_F_CURRENT_CPU)
629 		index = cpu;
630 	if (unlikely(index >= array->map.max_entries))
631 		return -E2BIG;
632 
633 	ee = READ_ONCE(array->ptrs[index]);
634 	if (!ee)
635 		return -ENOENT;
636 
637 	event = ee->event;
638 	if (unlikely(event->attr.type != PERF_TYPE_SOFTWARE ||
639 		     event->attr.config != PERF_COUNT_SW_BPF_OUTPUT))
640 		return -EINVAL;
641 
642 	if (unlikely(event->oncpu != cpu))
643 		return -EOPNOTSUPP;
644 
645 	perf_sample_save_raw_data(sd, event, raw);
646 
647 	return perf_event_output(event, sd, regs);
648 }
649 
650 /*
651  * Support executing tracepoints in normal, irq, and nmi context that each call
652  * bpf_perf_event_output
653  */
654 struct bpf_trace_sample_data {
655 	struct perf_sample_data sds[3];
656 };
657 
658 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_trace_sds);
659 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)660 BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map,
661 	   u64, flags, void *, data, u64, size)
662 {
663 	struct bpf_trace_sample_data *sds;
664 	struct perf_raw_record raw = {
665 		.frag = {
666 			.size = size,
667 			.data = data,
668 		},
669 	};
670 	struct perf_sample_data *sd;
671 	int nest_level, err;
672 
673 	preempt_disable();
674 	sds = this_cpu_ptr(&bpf_trace_sds);
675 	nest_level = this_cpu_inc_return(bpf_trace_nest_level);
676 
677 	if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(sds->sds))) {
678 		err = -EBUSY;
679 		goto out;
680 	}
681 
682 	sd = &sds->sds[nest_level - 1];
683 
684 	if (unlikely(flags & ~(BPF_F_INDEX_MASK))) {
685 		err = -EINVAL;
686 		goto out;
687 	}
688 
689 	perf_sample_data_init(sd, 0, 0);
690 
691 	err = __bpf_perf_event_output(regs, map, flags, &raw, sd);
692 out:
693 	this_cpu_dec(bpf_trace_nest_level);
694 	preempt_enable();
695 	return err;
696 }
697 
698 static const struct bpf_func_proto bpf_perf_event_output_proto = {
699 	.func		= bpf_perf_event_output,
700 	.gpl_only	= true,
701 	.ret_type	= RET_INTEGER,
702 	.arg1_type	= ARG_PTR_TO_CTX,
703 	.arg2_type	= ARG_CONST_MAP_PTR,
704 	.arg3_type	= ARG_ANYTHING,
705 	.arg4_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
706 	.arg5_type	= ARG_CONST_SIZE_OR_ZERO,
707 };
708 
709 static DEFINE_PER_CPU(int, bpf_event_output_nest_level);
710 struct bpf_nested_pt_regs {
711 	struct pt_regs regs[3];
712 };
713 static DEFINE_PER_CPU(struct bpf_nested_pt_regs, bpf_pt_regs);
714 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_misc_sds);
715 
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)716 u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
717 		     void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy)
718 {
719 	struct perf_raw_frag frag = {
720 		.copy		= ctx_copy,
721 		.size		= ctx_size,
722 		.data		= ctx,
723 	};
724 	struct perf_raw_record raw = {
725 		.frag = {
726 			{
727 				.next	= ctx_size ? &frag : NULL,
728 			},
729 			.size	= meta_size,
730 			.data	= meta,
731 		},
732 	};
733 	struct perf_sample_data *sd;
734 	struct pt_regs *regs;
735 	int nest_level;
736 	u64 ret;
737 
738 	preempt_disable();
739 	nest_level = this_cpu_inc_return(bpf_event_output_nest_level);
740 
741 	if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(bpf_misc_sds.sds))) {
742 		ret = -EBUSY;
743 		goto out;
744 	}
745 	sd = this_cpu_ptr(&bpf_misc_sds.sds[nest_level - 1]);
746 	regs = this_cpu_ptr(&bpf_pt_regs.regs[nest_level - 1]);
747 
748 	perf_fetch_caller_regs(regs);
749 	perf_sample_data_init(sd, 0, 0);
750 
751 	ret = __bpf_perf_event_output(regs, map, flags, &raw, sd);
752 out:
753 	this_cpu_dec(bpf_event_output_nest_level);
754 	preempt_enable();
755 	return ret;
756 }
757 
BPF_CALL_0(bpf_get_current_task)758 BPF_CALL_0(bpf_get_current_task)
759 {
760 	return (long) current;
761 }
762 
763 const struct bpf_func_proto bpf_get_current_task_proto = {
764 	.func		= bpf_get_current_task,
765 	.gpl_only	= true,
766 	.ret_type	= RET_INTEGER,
767 };
768 
BPF_CALL_0(bpf_get_current_task_btf)769 BPF_CALL_0(bpf_get_current_task_btf)
770 {
771 	return (unsigned long) current;
772 }
773 
774 const struct bpf_func_proto bpf_get_current_task_btf_proto = {
775 	.func		= bpf_get_current_task_btf,
776 	.gpl_only	= true,
777 	.ret_type	= RET_PTR_TO_BTF_ID_TRUSTED,
778 	.ret_btf_id	= &btf_tracing_ids[BTF_TRACING_TYPE_TASK],
779 };
780 
BPF_CALL_1(bpf_task_pt_regs,struct task_struct *,task)781 BPF_CALL_1(bpf_task_pt_regs, struct task_struct *, task)
782 {
783 	return (unsigned long) task_pt_regs(task);
784 }
785 
786 BTF_ID_LIST(bpf_task_pt_regs_ids)
787 BTF_ID(struct, pt_regs)
788 
789 const struct bpf_func_proto bpf_task_pt_regs_proto = {
790 	.func		= bpf_task_pt_regs,
791 	.gpl_only	= true,
792 	.arg1_type	= ARG_PTR_TO_BTF_ID,
793 	.arg1_btf_id	= &btf_tracing_ids[BTF_TRACING_TYPE_TASK],
794 	.ret_type	= RET_PTR_TO_BTF_ID,
795 	.ret_btf_id	= &bpf_task_pt_regs_ids[0],
796 };
797 
BPF_CALL_2(bpf_current_task_under_cgroup,struct bpf_map *,map,u32,idx)798 BPF_CALL_2(bpf_current_task_under_cgroup, struct bpf_map *, map, u32, idx)
799 {
800 	struct bpf_array *array = container_of(map, struct bpf_array, map);
801 	struct cgroup *cgrp;
802 
803 	if (unlikely(idx >= array->map.max_entries))
804 		return -E2BIG;
805 
806 	cgrp = READ_ONCE(array->ptrs[idx]);
807 	if (unlikely(!cgrp))
808 		return -EAGAIN;
809 
810 	return task_under_cgroup_hierarchy(current, cgrp);
811 }
812 
813 static const struct bpf_func_proto bpf_current_task_under_cgroup_proto = {
814 	.func           = bpf_current_task_under_cgroup,
815 	.gpl_only       = false,
816 	.ret_type       = RET_INTEGER,
817 	.arg1_type      = ARG_CONST_MAP_PTR,
818 	.arg2_type      = ARG_ANYTHING,
819 };
820 
821 struct send_signal_irq_work {
822 	struct irq_work irq_work;
823 	struct task_struct *task;
824 	u32 sig;
825 	enum pid_type type;
826 };
827 
828 static DEFINE_PER_CPU(struct send_signal_irq_work, send_signal_work);
829 
do_bpf_send_signal(struct irq_work * entry)830 static void do_bpf_send_signal(struct irq_work *entry)
831 {
832 	struct send_signal_irq_work *work;
833 
834 	work = container_of(entry, struct send_signal_irq_work, irq_work);
835 	group_send_sig_info(work->sig, SEND_SIG_PRIV, work->task, work->type);
836 	put_task_struct(work->task);
837 }
838 
bpf_send_signal_common(u32 sig,enum pid_type type)839 static int bpf_send_signal_common(u32 sig, enum pid_type type)
840 {
841 	struct send_signal_irq_work *work = NULL;
842 
843 	/* Similar to bpf_probe_write_user, task needs to be
844 	 * in a sound condition and kernel memory access be
845 	 * permitted in order to send signal to the current
846 	 * task.
847 	 */
848 	if (unlikely(current->flags & (PF_KTHREAD | PF_EXITING)))
849 		return -EPERM;
850 	if (unlikely(!nmi_uaccess_okay()))
851 		return -EPERM;
852 	/* Task should not be pid=1 to avoid kernel panic. */
853 	if (unlikely(is_global_init(current)))
854 		return -EPERM;
855 
856 	if (irqs_disabled()) {
857 		/* Do an early check on signal validity. Otherwise,
858 		 * the error is lost in deferred irq_work.
859 		 */
860 		if (unlikely(!valid_signal(sig)))
861 			return -EINVAL;
862 
863 		work = this_cpu_ptr(&send_signal_work);
864 		if (irq_work_is_busy(&work->irq_work))
865 			return -EBUSY;
866 
867 		/* Add the current task, which is the target of sending signal,
868 		 * to the irq_work. The current task may change when queued
869 		 * irq works get executed.
870 		 */
871 		work->task = get_task_struct(current);
872 		work->sig = sig;
873 		work->type = type;
874 		irq_work_queue(&work->irq_work);
875 		return 0;
876 	}
877 
878 	return group_send_sig_info(sig, SEND_SIG_PRIV, current, type);
879 }
880 
BPF_CALL_1(bpf_send_signal,u32,sig)881 BPF_CALL_1(bpf_send_signal, u32, sig)
882 {
883 	return bpf_send_signal_common(sig, PIDTYPE_TGID);
884 }
885 
886 static const struct bpf_func_proto bpf_send_signal_proto = {
887 	.func		= bpf_send_signal,
888 	.gpl_only	= false,
889 	.ret_type	= RET_INTEGER,
890 	.arg1_type	= ARG_ANYTHING,
891 };
892 
BPF_CALL_1(bpf_send_signal_thread,u32,sig)893 BPF_CALL_1(bpf_send_signal_thread, u32, sig)
894 {
895 	return bpf_send_signal_common(sig, PIDTYPE_PID);
896 }
897 
898 static const struct bpf_func_proto bpf_send_signal_thread_proto = {
899 	.func		= bpf_send_signal_thread,
900 	.gpl_only	= false,
901 	.ret_type	= RET_INTEGER,
902 	.arg1_type	= ARG_ANYTHING,
903 };
904 
BPF_CALL_3(bpf_d_path,struct path *,path,char *,buf,u32,sz)905 BPF_CALL_3(bpf_d_path, struct path *, path, char *, buf, u32, sz)
906 {
907 	struct path copy;
908 	long len;
909 	char *p;
910 
911 	if (!sz)
912 		return 0;
913 
914 	/*
915 	 * The path pointer is verified as trusted and safe to use,
916 	 * but let's double check it's valid anyway to workaround
917 	 * potentially broken verifier.
918 	 */
919 	len = copy_from_kernel_nofault(&copy, path, sizeof(*path));
920 	if (len < 0)
921 		return len;
922 
923 	p = d_path(&copy, buf, sz);
924 	if (IS_ERR(p)) {
925 		len = PTR_ERR(p);
926 	} else {
927 		len = buf + sz - p;
928 		memmove(buf, p, len);
929 	}
930 
931 	return len;
932 }
933 
934 BTF_SET_START(btf_allowlist_d_path)
935 #ifdef CONFIG_SECURITY
BTF_ID(func,security_file_permission)936 BTF_ID(func, security_file_permission)
937 BTF_ID(func, security_inode_getattr)
938 BTF_ID(func, security_file_open)
939 #endif
940 #ifdef CONFIG_SECURITY_PATH
941 BTF_ID(func, security_path_truncate)
942 #endif
943 BTF_ID(func, vfs_truncate)
944 BTF_ID(func, vfs_fallocate)
945 BTF_ID(func, dentry_open)
946 BTF_ID(func, vfs_getattr)
947 BTF_ID(func, filp_close)
948 BTF_SET_END(btf_allowlist_d_path)
949 
950 static bool bpf_d_path_allowed(const struct bpf_prog *prog)
951 {
952 	if (prog->type == BPF_PROG_TYPE_TRACING &&
953 	    prog->expected_attach_type == BPF_TRACE_ITER)
954 		return true;
955 
956 	if (prog->type == BPF_PROG_TYPE_LSM)
957 		return bpf_lsm_is_sleepable_hook(prog->aux->attach_btf_id);
958 
959 	return btf_id_set_contains(&btf_allowlist_d_path,
960 				   prog->aux->attach_btf_id);
961 }
962 
963 BTF_ID_LIST_SINGLE(bpf_d_path_btf_ids, struct, path)
964 
965 static const struct bpf_func_proto bpf_d_path_proto = {
966 	.func		= bpf_d_path,
967 	.gpl_only	= false,
968 	.ret_type	= RET_INTEGER,
969 	.arg1_type	= ARG_PTR_TO_BTF_ID,
970 	.arg1_btf_id	= &bpf_d_path_btf_ids[0],
971 	.arg2_type	= ARG_PTR_TO_MEM,
972 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
973 	.allowed	= bpf_d_path_allowed,
974 };
975 
976 #define BTF_F_ALL	(BTF_F_COMPACT  | BTF_F_NONAME | \
977 			 BTF_F_PTR_RAW | BTF_F_ZERO)
978 
bpf_btf_printf_prepare(struct btf_ptr * ptr,u32 btf_ptr_size,u64 flags,const struct btf ** btf,s32 * btf_id)979 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size,
980 				  u64 flags, const struct btf **btf,
981 				  s32 *btf_id)
982 {
983 	const struct btf_type *t;
984 
985 	if (unlikely(flags & ~(BTF_F_ALL)))
986 		return -EINVAL;
987 
988 	if (btf_ptr_size != sizeof(struct btf_ptr))
989 		return -EINVAL;
990 
991 	*btf = bpf_get_btf_vmlinux();
992 
993 	if (IS_ERR_OR_NULL(*btf))
994 		return IS_ERR(*btf) ? PTR_ERR(*btf) : -EINVAL;
995 
996 	if (ptr->type_id > 0)
997 		*btf_id = ptr->type_id;
998 	else
999 		return -EINVAL;
1000 
1001 	if (*btf_id > 0)
1002 		t = btf_type_by_id(*btf, *btf_id);
1003 	if (*btf_id <= 0 || !t)
1004 		return -ENOENT;
1005 
1006 	return 0;
1007 }
1008 
BPF_CALL_5(bpf_snprintf_btf,char *,str,u32,str_size,struct btf_ptr *,ptr,u32,btf_ptr_size,u64,flags)1009 BPF_CALL_5(bpf_snprintf_btf, char *, str, u32, str_size, struct btf_ptr *, ptr,
1010 	   u32, btf_ptr_size, u64, flags)
1011 {
1012 	const struct btf *btf;
1013 	s32 btf_id;
1014 	int ret;
1015 
1016 	ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id);
1017 	if (ret)
1018 		return ret;
1019 
1020 	return btf_type_snprintf_show(btf, btf_id, ptr->ptr, str, str_size,
1021 				      flags);
1022 }
1023 
1024 const struct bpf_func_proto bpf_snprintf_btf_proto = {
1025 	.func		= bpf_snprintf_btf,
1026 	.gpl_only	= false,
1027 	.ret_type	= RET_INTEGER,
1028 	.arg1_type	= ARG_PTR_TO_MEM,
1029 	.arg2_type	= ARG_CONST_SIZE,
1030 	.arg3_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
1031 	.arg4_type	= ARG_CONST_SIZE,
1032 	.arg5_type	= ARG_ANYTHING,
1033 };
1034 
BPF_CALL_1(bpf_get_func_ip_tracing,void *,ctx)1035 BPF_CALL_1(bpf_get_func_ip_tracing, void *, ctx)
1036 {
1037 	/* This helper call is inlined by verifier. */
1038 	return ((u64 *)ctx)[-2];
1039 }
1040 
1041 static const struct bpf_func_proto bpf_get_func_ip_proto_tracing = {
1042 	.func		= bpf_get_func_ip_tracing,
1043 	.gpl_only	= true,
1044 	.ret_type	= RET_INTEGER,
1045 	.arg1_type	= ARG_PTR_TO_CTX,
1046 };
1047 
1048 #ifdef CONFIG_X86_KERNEL_IBT
get_entry_ip(unsigned long fentry_ip)1049 static unsigned long get_entry_ip(unsigned long fentry_ip)
1050 {
1051 	u32 instr;
1052 
1053 	/* Being extra safe in here in case entry ip is on the page-edge. */
1054 	if (get_kernel_nofault(instr, (u32 *) fentry_ip - 1))
1055 		return fentry_ip;
1056 	if (is_endbr(instr))
1057 		fentry_ip -= ENDBR_INSN_SIZE;
1058 	return fentry_ip;
1059 }
1060 #else
1061 #define get_entry_ip(fentry_ip) fentry_ip
1062 #endif
1063 
BPF_CALL_1(bpf_get_func_ip_kprobe,struct pt_regs *,regs)1064 BPF_CALL_1(bpf_get_func_ip_kprobe, struct pt_regs *, regs)
1065 {
1066 	struct bpf_trace_run_ctx *run_ctx __maybe_unused;
1067 	struct kprobe *kp;
1068 
1069 #ifdef CONFIG_UPROBES
1070 	run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx);
1071 	if (run_ctx->is_uprobe)
1072 		return ((struct uprobe_dispatch_data *)current->utask->vaddr)->bp_addr;
1073 #endif
1074 
1075 	kp = kprobe_running();
1076 
1077 	if (!kp || !(kp->flags & KPROBE_FLAG_ON_FUNC_ENTRY))
1078 		return 0;
1079 
1080 	return get_entry_ip((uintptr_t)kp->addr);
1081 }
1082 
1083 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe = {
1084 	.func		= bpf_get_func_ip_kprobe,
1085 	.gpl_only	= true,
1086 	.ret_type	= RET_INTEGER,
1087 	.arg1_type	= ARG_PTR_TO_CTX,
1088 };
1089 
BPF_CALL_1(bpf_get_func_ip_kprobe_multi,struct pt_regs *,regs)1090 BPF_CALL_1(bpf_get_func_ip_kprobe_multi, struct pt_regs *, regs)
1091 {
1092 	return bpf_kprobe_multi_entry_ip(current->bpf_ctx);
1093 }
1094 
1095 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe_multi = {
1096 	.func		= bpf_get_func_ip_kprobe_multi,
1097 	.gpl_only	= false,
1098 	.ret_type	= RET_INTEGER,
1099 	.arg1_type	= ARG_PTR_TO_CTX,
1100 };
1101 
BPF_CALL_1(bpf_get_attach_cookie_kprobe_multi,struct pt_regs *,regs)1102 BPF_CALL_1(bpf_get_attach_cookie_kprobe_multi, struct pt_regs *, regs)
1103 {
1104 	return bpf_kprobe_multi_cookie(current->bpf_ctx);
1105 }
1106 
1107 static const struct bpf_func_proto bpf_get_attach_cookie_proto_kmulti = {
1108 	.func		= bpf_get_attach_cookie_kprobe_multi,
1109 	.gpl_only	= false,
1110 	.ret_type	= RET_INTEGER,
1111 	.arg1_type	= ARG_PTR_TO_CTX,
1112 };
1113 
BPF_CALL_1(bpf_get_func_ip_uprobe_multi,struct pt_regs *,regs)1114 BPF_CALL_1(bpf_get_func_ip_uprobe_multi, struct pt_regs *, regs)
1115 {
1116 	return bpf_uprobe_multi_entry_ip(current->bpf_ctx);
1117 }
1118 
1119 static const struct bpf_func_proto bpf_get_func_ip_proto_uprobe_multi = {
1120 	.func		= bpf_get_func_ip_uprobe_multi,
1121 	.gpl_only	= false,
1122 	.ret_type	= RET_INTEGER,
1123 	.arg1_type	= ARG_PTR_TO_CTX,
1124 };
1125 
BPF_CALL_1(bpf_get_attach_cookie_uprobe_multi,struct pt_regs *,regs)1126 BPF_CALL_1(bpf_get_attach_cookie_uprobe_multi, struct pt_regs *, regs)
1127 {
1128 	return bpf_uprobe_multi_cookie(current->bpf_ctx);
1129 }
1130 
1131 static const struct bpf_func_proto bpf_get_attach_cookie_proto_umulti = {
1132 	.func		= bpf_get_attach_cookie_uprobe_multi,
1133 	.gpl_only	= false,
1134 	.ret_type	= RET_INTEGER,
1135 	.arg1_type	= ARG_PTR_TO_CTX,
1136 };
1137 
BPF_CALL_1(bpf_get_attach_cookie_trace,void *,ctx)1138 BPF_CALL_1(bpf_get_attach_cookie_trace, void *, ctx)
1139 {
1140 	struct bpf_trace_run_ctx *run_ctx;
1141 
1142 	run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx);
1143 	return run_ctx->bpf_cookie;
1144 }
1145 
1146 static const struct bpf_func_proto bpf_get_attach_cookie_proto_trace = {
1147 	.func		= bpf_get_attach_cookie_trace,
1148 	.gpl_only	= false,
1149 	.ret_type	= RET_INTEGER,
1150 	.arg1_type	= ARG_PTR_TO_CTX,
1151 };
1152 
BPF_CALL_1(bpf_get_attach_cookie_pe,struct bpf_perf_event_data_kern *,ctx)1153 BPF_CALL_1(bpf_get_attach_cookie_pe, struct bpf_perf_event_data_kern *, ctx)
1154 {
1155 	return ctx->event->bpf_cookie;
1156 }
1157 
1158 static const struct bpf_func_proto bpf_get_attach_cookie_proto_pe = {
1159 	.func		= bpf_get_attach_cookie_pe,
1160 	.gpl_only	= false,
1161 	.ret_type	= RET_INTEGER,
1162 	.arg1_type	= ARG_PTR_TO_CTX,
1163 };
1164 
BPF_CALL_1(bpf_get_attach_cookie_tracing,void *,ctx)1165 BPF_CALL_1(bpf_get_attach_cookie_tracing, void *, ctx)
1166 {
1167 	struct bpf_trace_run_ctx *run_ctx;
1168 
1169 	run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx);
1170 	return run_ctx->bpf_cookie;
1171 }
1172 
1173 static const struct bpf_func_proto bpf_get_attach_cookie_proto_tracing = {
1174 	.func		= bpf_get_attach_cookie_tracing,
1175 	.gpl_only	= false,
1176 	.ret_type	= RET_INTEGER,
1177 	.arg1_type	= ARG_PTR_TO_CTX,
1178 };
1179 
BPF_CALL_3(bpf_get_branch_snapshot,void *,buf,u32,size,u64,flags)1180 BPF_CALL_3(bpf_get_branch_snapshot, void *, buf, u32, size, u64, flags)
1181 {
1182 #ifndef CONFIG_X86
1183 	return -ENOENT;
1184 #else
1185 	static const u32 br_entry_size = sizeof(struct perf_branch_entry);
1186 	u32 entry_cnt = size / br_entry_size;
1187 
1188 	entry_cnt = static_call(perf_snapshot_branch_stack)(buf, entry_cnt);
1189 
1190 	if (unlikely(flags))
1191 		return -EINVAL;
1192 
1193 	if (!entry_cnt)
1194 		return -ENOENT;
1195 
1196 	return entry_cnt * br_entry_size;
1197 #endif
1198 }
1199 
1200 static const struct bpf_func_proto bpf_get_branch_snapshot_proto = {
1201 	.func		= bpf_get_branch_snapshot,
1202 	.gpl_only	= true,
1203 	.ret_type	= RET_INTEGER,
1204 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
1205 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
1206 };
1207 
BPF_CALL_3(get_func_arg,void *,ctx,u32,n,u64 *,value)1208 BPF_CALL_3(get_func_arg, void *, ctx, u32, n, u64 *, value)
1209 {
1210 	/* This helper call is inlined by verifier. */
1211 	u64 nr_args = ((u64 *)ctx)[-1];
1212 
1213 	if ((u64) n >= nr_args)
1214 		return -EINVAL;
1215 	*value = ((u64 *)ctx)[n];
1216 	return 0;
1217 }
1218 
1219 static const struct bpf_func_proto bpf_get_func_arg_proto = {
1220 	.func		= get_func_arg,
1221 	.ret_type	= RET_INTEGER,
1222 	.arg1_type	= ARG_PTR_TO_CTX,
1223 	.arg2_type	= ARG_ANYTHING,
1224 	.arg3_type	= ARG_PTR_TO_LONG,
1225 };
1226 
BPF_CALL_2(get_func_ret,void *,ctx,u64 *,value)1227 BPF_CALL_2(get_func_ret, void *, ctx, u64 *, value)
1228 {
1229 	/* This helper call is inlined by verifier. */
1230 	u64 nr_args = ((u64 *)ctx)[-1];
1231 
1232 	*value = ((u64 *)ctx)[nr_args];
1233 	return 0;
1234 }
1235 
1236 static const struct bpf_func_proto bpf_get_func_ret_proto = {
1237 	.func		= get_func_ret,
1238 	.ret_type	= RET_INTEGER,
1239 	.arg1_type	= ARG_PTR_TO_CTX,
1240 	.arg2_type	= ARG_PTR_TO_LONG,
1241 };
1242 
BPF_CALL_1(get_func_arg_cnt,void *,ctx)1243 BPF_CALL_1(get_func_arg_cnt, void *, ctx)
1244 {
1245 	/* This helper call is inlined by verifier. */
1246 	return ((u64 *)ctx)[-1];
1247 }
1248 
1249 static const struct bpf_func_proto bpf_get_func_arg_cnt_proto = {
1250 	.func		= get_func_arg_cnt,
1251 	.ret_type	= RET_INTEGER,
1252 	.arg1_type	= ARG_PTR_TO_CTX,
1253 };
1254 
1255 #ifdef CONFIG_KEYS
1256 __diag_push();
1257 __diag_ignore_all("-Wmissing-prototypes",
1258 		  "kfuncs which will be used in BPF programs");
1259 
1260 /**
1261  * bpf_lookup_user_key - lookup a key by its serial
1262  * @serial: key handle serial number
1263  * @flags: lookup-specific flags
1264  *
1265  * Search a key with a given *serial* and the provided *flags*.
1266  * If found, increment the reference count of the key by one, and
1267  * return it in the bpf_key structure.
1268  *
1269  * The bpf_key structure must be passed to bpf_key_put() when done
1270  * with it, so that the key reference count is decremented and the
1271  * bpf_key structure is freed.
1272  *
1273  * Permission checks are deferred to the time the key is used by
1274  * one of the available key-specific kfuncs.
1275  *
1276  * Set *flags* with KEY_LOOKUP_CREATE, to attempt creating a requested
1277  * special keyring (e.g. session keyring), if it doesn't yet exist.
1278  * Set *flags* with KEY_LOOKUP_PARTIAL, to lookup a key without waiting
1279  * for the key construction, and to retrieve uninstantiated keys (keys
1280  * without data attached to them).
1281  *
1282  * Return: a bpf_key pointer with a valid key pointer if the key is found, a
1283  *         NULL pointer otherwise.
1284  */
bpf_lookup_user_key(u32 serial,u64 flags)1285 __bpf_kfunc struct bpf_key *bpf_lookup_user_key(u32 serial, u64 flags)
1286 {
1287 	key_ref_t key_ref;
1288 	struct bpf_key *bkey;
1289 
1290 	if (flags & ~KEY_LOOKUP_ALL)
1291 		return NULL;
1292 
1293 	/*
1294 	 * Permission check is deferred until the key is used, as the
1295 	 * intent of the caller is unknown here.
1296 	 */
1297 	key_ref = lookup_user_key(serial, flags, KEY_DEFER_PERM_CHECK);
1298 	if (IS_ERR(key_ref))
1299 		return NULL;
1300 
1301 	bkey = kmalloc(sizeof(*bkey), GFP_KERNEL);
1302 	if (!bkey) {
1303 		key_put(key_ref_to_ptr(key_ref));
1304 		return NULL;
1305 	}
1306 
1307 	bkey->key = key_ref_to_ptr(key_ref);
1308 	bkey->has_ref = true;
1309 
1310 	return bkey;
1311 }
1312 
1313 /**
1314  * bpf_lookup_system_key - lookup a key by a system-defined ID
1315  * @id: key ID
1316  *
1317  * Obtain a bpf_key structure with a key pointer set to the passed key ID.
1318  * The key pointer is marked as invalid, to prevent bpf_key_put() from
1319  * attempting to decrement the key reference count on that pointer. The key
1320  * pointer set in such way is currently understood only by
1321  * verify_pkcs7_signature().
1322  *
1323  * Set *id* to one of the values defined in include/linux/verification.h:
1324  * 0 for the primary keyring (immutable keyring of system keys);
1325  * VERIFY_USE_SECONDARY_KEYRING for both the primary and secondary keyring
1326  * (where keys can be added only if they are vouched for by existing keys
1327  * in those keyrings); VERIFY_USE_PLATFORM_KEYRING for the platform
1328  * keyring (primarily used by the integrity subsystem to verify a kexec'ed
1329  * kerned image and, possibly, the initramfs signature).
1330  *
1331  * Return: a bpf_key pointer with an invalid key pointer set from the
1332  *         pre-determined ID on success, a NULL pointer otherwise
1333  */
bpf_lookup_system_key(u64 id)1334 __bpf_kfunc struct bpf_key *bpf_lookup_system_key(u64 id)
1335 {
1336 	struct bpf_key *bkey;
1337 
1338 	if (system_keyring_id_check(id) < 0)
1339 		return NULL;
1340 
1341 	bkey = kmalloc(sizeof(*bkey), GFP_ATOMIC);
1342 	if (!bkey)
1343 		return NULL;
1344 
1345 	bkey->key = (struct key *)(unsigned long)id;
1346 	bkey->has_ref = false;
1347 
1348 	return bkey;
1349 }
1350 
1351 /**
1352  * bpf_key_put - decrement key reference count if key is valid and free bpf_key
1353  * @bkey: bpf_key structure
1354  *
1355  * Decrement the reference count of the key inside *bkey*, if the pointer
1356  * is valid, and free *bkey*.
1357  */
bpf_key_put(struct bpf_key * bkey)1358 __bpf_kfunc void bpf_key_put(struct bpf_key *bkey)
1359 {
1360 	if (bkey->has_ref)
1361 		key_put(bkey->key);
1362 
1363 	kfree(bkey);
1364 }
1365 
1366 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION
1367 /**
1368  * bpf_verify_pkcs7_signature - verify a PKCS#7 signature
1369  * @data_ptr: data to verify
1370  * @sig_ptr: signature of the data
1371  * @trusted_keyring: keyring with keys trusted for signature verification
1372  *
1373  * Verify the PKCS#7 signature *sig_ptr* against the supplied *data_ptr*
1374  * with keys in a keyring referenced by *trusted_keyring*.
1375  *
1376  * Return: 0 on success, a negative value on error.
1377  */
bpf_verify_pkcs7_signature(struct bpf_dynptr_kern * data_ptr,struct bpf_dynptr_kern * sig_ptr,struct bpf_key * trusted_keyring)1378 __bpf_kfunc int bpf_verify_pkcs7_signature(struct bpf_dynptr_kern *data_ptr,
1379 			       struct bpf_dynptr_kern *sig_ptr,
1380 			       struct bpf_key *trusted_keyring)
1381 {
1382 	int ret;
1383 
1384 	if (trusted_keyring->has_ref) {
1385 		/*
1386 		 * Do the permission check deferred in bpf_lookup_user_key().
1387 		 * See bpf_lookup_user_key() for more details.
1388 		 *
1389 		 * A call to key_task_permission() here would be redundant, as
1390 		 * it is already done by keyring_search() called by
1391 		 * find_asymmetric_key().
1392 		 */
1393 		ret = key_validate(trusted_keyring->key);
1394 		if (ret < 0)
1395 			return ret;
1396 	}
1397 
1398 	return verify_pkcs7_signature(data_ptr->data,
1399 				      __bpf_dynptr_size(data_ptr),
1400 				      sig_ptr->data,
1401 				      __bpf_dynptr_size(sig_ptr),
1402 				      trusted_keyring->key,
1403 				      VERIFYING_UNSPECIFIED_SIGNATURE, NULL,
1404 				      NULL);
1405 }
1406 #endif /* CONFIG_SYSTEM_DATA_VERIFICATION */
1407 
1408 __diag_pop();
1409 
1410 BTF_SET8_START(key_sig_kfunc_set)
1411 BTF_ID_FLAGS(func, bpf_lookup_user_key, KF_ACQUIRE | KF_RET_NULL | KF_SLEEPABLE)
1412 BTF_ID_FLAGS(func, bpf_lookup_system_key, KF_ACQUIRE | KF_RET_NULL)
1413 BTF_ID_FLAGS(func, bpf_key_put, KF_RELEASE)
1414 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION
1415 BTF_ID_FLAGS(func, bpf_verify_pkcs7_signature, KF_SLEEPABLE)
1416 #endif
1417 BTF_SET8_END(key_sig_kfunc_set)
1418 
1419 static const struct btf_kfunc_id_set bpf_key_sig_kfunc_set = {
1420 	.owner = THIS_MODULE,
1421 	.set = &key_sig_kfunc_set,
1422 };
1423 
bpf_key_sig_kfuncs_init(void)1424 static int __init bpf_key_sig_kfuncs_init(void)
1425 {
1426 	return register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING,
1427 					 &bpf_key_sig_kfunc_set);
1428 }
1429 
1430 late_initcall(bpf_key_sig_kfuncs_init);
1431 #endif /* CONFIG_KEYS */
1432 
1433 static const struct bpf_func_proto *
bpf_tracing_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1434 bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1435 {
1436 	switch (func_id) {
1437 	case BPF_FUNC_map_lookup_elem:
1438 		return &bpf_map_lookup_elem_proto;
1439 	case BPF_FUNC_map_update_elem:
1440 		return &bpf_map_update_elem_proto;
1441 	case BPF_FUNC_map_delete_elem:
1442 		return &bpf_map_delete_elem_proto;
1443 	case BPF_FUNC_map_push_elem:
1444 		return &bpf_map_push_elem_proto;
1445 	case BPF_FUNC_map_pop_elem:
1446 		return &bpf_map_pop_elem_proto;
1447 	case BPF_FUNC_map_peek_elem:
1448 		return &bpf_map_peek_elem_proto;
1449 	case BPF_FUNC_map_lookup_percpu_elem:
1450 		return &bpf_map_lookup_percpu_elem_proto;
1451 	case BPF_FUNC_ktime_get_ns:
1452 		return &bpf_ktime_get_ns_proto;
1453 	case BPF_FUNC_ktime_get_boot_ns:
1454 		return &bpf_ktime_get_boot_ns_proto;
1455 	case BPF_FUNC_tail_call:
1456 		return &bpf_tail_call_proto;
1457 	case BPF_FUNC_get_current_pid_tgid:
1458 		return &bpf_get_current_pid_tgid_proto;
1459 	case BPF_FUNC_get_current_task:
1460 		return &bpf_get_current_task_proto;
1461 	case BPF_FUNC_get_current_task_btf:
1462 		return &bpf_get_current_task_btf_proto;
1463 	case BPF_FUNC_task_pt_regs:
1464 		return &bpf_task_pt_regs_proto;
1465 	case BPF_FUNC_get_current_uid_gid:
1466 		return &bpf_get_current_uid_gid_proto;
1467 	case BPF_FUNC_get_current_comm:
1468 		return &bpf_get_current_comm_proto;
1469 	case BPF_FUNC_trace_printk:
1470 		return bpf_get_trace_printk_proto();
1471 	case BPF_FUNC_get_smp_processor_id:
1472 		return &bpf_get_smp_processor_id_proto;
1473 	case BPF_FUNC_get_numa_node_id:
1474 		return &bpf_get_numa_node_id_proto;
1475 	case BPF_FUNC_perf_event_read:
1476 		return &bpf_perf_event_read_proto;
1477 	case BPF_FUNC_current_task_under_cgroup:
1478 		return &bpf_current_task_under_cgroup_proto;
1479 	case BPF_FUNC_get_prandom_u32:
1480 		return &bpf_get_prandom_u32_proto;
1481 	case BPF_FUNC_probe_write_user:
1482 		return security_locked_down(LOCKDOWN_BPF_WRITE_USER) < 0 ?
1483 		       NULL : bpf_get_probe_write_proto();
1484 	case BPF_FUNC_probe_read_user:
1485 		return &bpf_probe_read_user_proto;
1486 	case BPF_FUNC_probe_read_kernel:
1487 		return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
1488 		       NULL : &bpf_probe_read_kernel_proto;
1489 	case BPF_FUNC_probe_read_user_str:
1490 		return &bpf_probe_read_user_str_proto;
1491 	case BPF_FUNC_probe_read_kernel_str:
1492 		return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
1493 		       NULL : &bpf_probe_read_kernel_str_proto;
1494 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
1495 	case BPF_FUNC_probe_read:
1496 		return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
1497 		       NULL : &bpf_probe_read_compat_proto;
1498 	case BPF_FUNC_probe_read_str:
1499 		return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
1500 		       NULL : &bpf_probe_read_compat_str_proto;
1501 #endif
1502 #ifdef CONFIG_CGROUPS
1503 	case BPF_FUNC_cgrp_storage_get:
1504 		return &bpf_cgrp_storage_get_proto;
1505 	case BPF_FUNC_cgrp_storage_delete:
1506 		return &bpf_cgrp_storage_delete_proto;
1507 #endif
1508 	case BPF_FUNC_send_signal:
1509 		return &bpf_send_signal_proto;
1510 	case BPF_FUNC_send_signal_thread:
1511 		return &bpf_send_signal_thread_proto;
1512 	case BPF_FUNC_perf_event_read_value:
1513 		return &bpf_perf_event_read_value_proto;
1514 	case BPF_FUNC_get_ns_current_pid_tgid:
1515 		return &bpf_get_ns_current_pid_tgid_proto;
1516 	case BPF_FUNC_ringbuf_output:
1517 		return &bpf_ringbuf_output_proto;
1518 	case BPF_FUNC_ringbuf_reserve:
1519 		return &bpf_ringbuf_reserve_proto;
1520 	case BPF_FUNC_ringbuf_submit:
1521 		return &bpf_ringbuf_submit_proto;
1522 	case BPF_FUNC_ringbuf_discard:
1523 		return &bpf_ringbuf_discard_proto;
1524 	case BPF_FUNC_ringbuf_query:
1525 		return &bpf_ringbuf_query_proto;
1526 	case BPF_FUNC_jiffies64:
1527 		return &bpf_jiffies64_proto;
1528 	case BPF_FUNC_get_task_stack:
1529 		return &bpf_get_task_stack_proto;
1530 	case BPF_FUNC_copy_from_user:
1531 		return &bpf_copy_from_user_proto;
1532 	case BPF_FUNC_copy_from_user_task:
1533 		return &bpf_copy_from_user_task_proto;
1534 	case BPF_FUNC_snprintf_btf:
1535 		return &bpf_snprintf_btf_proto;
1536 	case BPF_FUNC_per_cpu_ptr:
1537 		return &bpf_per_cpu_ptr_proto;
1538 	case BPF_FUNC_this_cpu_ptr:
1539 		return &bpf_this_cpu_ptr_proto;
1540 	case BPF_FUNC_task_storage_get:
1541 		if (bpf_prog_check_recur(prog))
1542 			return &bpf_task_storage_get_recur_proto;
1543 		return &bpf_task_storage_get_proto;
1544 	case BPF_FUNC_task_storage_delete:
1545 		if (bpf_prog_check_recur(prog))
1546 			return &bpf_task_storage_delete_recur_proto;
1547 		return &bpf_task_storage_delete_proto;
1548 	case BPF_FUNC_for_each_map_elem:
1549 		return &bpf_for_each_map_elem_proto;
1550 	case BPF_FUNC_snprintf:
1551 		return &bpf_snprintf_proto;
1552 	case BPF_FUNC_get_func_ip:
1553 		return &bpf_get_func_ip_proto_tracing;
1554 	case BPF_FUNC_get_branch_snapshot:
1555 		return &bpf_get_branch_snapshot_proto;
1556 	case BPF_FUNC_find_vma:
1557 		return &bpf_find_vma_proto;
1558 	case BPF_FUNC_trace_vprintk:
1559 		return bpf_get_trace_vprintk_proto();
1560 	default:
1561 		return bpf_base_func_proto(func_id);
1562 	}
1563 }
1564 
1565 static const struct bpf_func_proto *
kprobe_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1566 kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1567 {
1568 	switch (func_id) {
1569 	case BPF_FUNC_perf_event_output:
1570 		return &bpf_perf_event_output_proto;
1571 	case BPF_FUNC_get_stackid:
1572 		return &bpf_get_stackid_proto;
1573 	case BPF_FUNC_get_stack:
1574 		return &bpf_get_stack_proto;
1575 #ifdef CONFIG_BPF_KPROBE_OVERRIDE
1576 	case BPF_FUNC_override_return:
1577 		return &bpf_override_return_proto;
1578 #endif
1579 	case BPF_FUNC_get_func_ip:
1580 		if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI)
1581 			return &bpf_get_func_ip_proto_kprobe_multi;
1582 		if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI)
1583 			return &bpf_get_func_ip_proto_uprobe_multi;
1584 		return &bpf_get_func_ip_proto_kprobe;
1585 	case BPF_FUNC_get_attach_cookie:
1586 		if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI)
1587 			return &bpf_get_attach_cookie_proto_kmulti;
1588 		if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI)
1589 			return &bpf_get_attach_cookie_proto_umulti;
1590 		return &bpf_get_attach_cookie_proto_trace;
1591 	default:
1592 		return bpf_tracing_func_proto(func_id, prog);
1593 	}
1594 }
1595 
1596 /* 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)1597 static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
1598 					const struct bpf_prog *prog,
1599 					struct bpf_insn_access_aux *info)
1600 {
1601 	if (off < 0 || off >= sizeof(struct pt_regs))
1602 		return false;
1603 	if (type != BPF_READ)
1604 		return false;
1605 	if (off % size != 0)
1606 		return false;
1607 	/*
1608 	 * Assertion for 32 bit to make sure last 8 byte access
1609 	 * (BPF_DW) to the last 4 byte member is disallowed.
1610 	 */
1611 	if (off + size > sizeof(struct pt_regs))
1612 		return false;
1613 
1614 	return true;
1615 }
1616 
1617 const struct bpf_verifier_ops kprobe_verifier_ops = {
1618 	.get_func_proto  = kprobe_prog_func_proto,
1619 	.is_valid_access = kprobe_prog_is_valid_access,
1620 };
1621 
1622 const struct bpf_prog_ops kprobe_prog_ops = {
1623 };
1624 
BPF_CALL_5(bpf_perf_event_output_tp,void *,tp_buff,struct bpf_map *,map,u64,flags,void *,data,u64,size)1625 BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map,
1626 	   u64, flags, void *, data, u64, size)
1627 {
1628 	struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1629 
1630 	/*
1631 	 * r1 points to perf tracepoint buffer where first 8 bytes are hidden
1632 	 * from bpf program and contain a pointer to 'struct pt_regs'. Fetch it
1633 	 * from there and call the same bpf_perf_event_output() helper inline.
1634 	 */
1635 	return ____bpf_perf_event_output(regs, map, flags, data, size);
1636 }
1637 
1638 static const struct bpf_func_proto bpf_perf_event_output_proto_tp = {
1639 	.func		= bpf_perf_event_output_tp,
1640 	.gpl_only	= true,
1641 	.ret_type	= RET_INTEGER,
1642 	.arg1_type	= ARG_PTR_TO_CTX,
1643 	.arg2_type	= ARG_CONST_MAP_PTR,
1644 	.arg3_type	= ARG_ANYTHING,
1645 	.arg4_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
1646 	.arg5_type	= ARG_CONST_SIZE_OR_ZERO,
1647 };
1648 
BPF_CALL_3(bpf_get_stackid_tp,void *,tp_buff,struct bpf_map *,map,u64,flags)1649 BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map,
1650 	   u64, flags)
1651 {
1652 	struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1653 
1654 	/*
1655 	 * Same comment as in bpf_perf_event_output_tp(), only that this time
1656 	 * the other helper's function body cannot be inlined due to being
1657 	 * external, thus we need to call raw helper function.
1658 	 */
1659 	return bpf_get_stackid((unsigned long) regs, (unsigned long) map,
1660 			       flags, 0, 0);
1661 }
1662 
1663 static const struct bpf_func_proto bpf_get_stackid_proto_tp = {
1664 	.func		= bpf_get_stackid_tp,
1665 	.gpl_only	= true,
1666 	.ret_type	= RET_INTEGER,
1667 	.arg1_type	= ARG_PTR_TO_CTX,
1668 	.arg2_type	= ARG_CONST_MAP_PTR,
1669 	.arg3_type	= ARG_ANYTHING,
1670 };
1671 
BPF_CALL_4(bpf_get_stack_tp,void *,tp_buff,void *,buf,u32,size,u64,flags)1672 BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size,
1673 	   u64, flags)
1674 {
1675 	struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1676 
1677 	return bpf_get_stack((unsigned long) regs, (unsigned long) buf,
1678 			     (unsigned long) size, flags, 0);
1679 }
1680 
1681 static const struct bpf_func_proto bpf_get_stack_proto_tp = {
1682 	.func		= bpf_get_stack_tp,
1683 	.gpl_only	= true,
1684 	.ret_type	= RET_INTEGER,
1685 	.arg1_type	= ARG_PTR_TO_CTX,
1686 	.arg2_type	= ARG_PTR_TO_UNINIT_MEM,
1687 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
1688 	.arg4_type	= ARG_ANYTHING,
1689 };
1690 
1691 static const struct bpf_func_proto *
tp_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1692 tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1693 {
1694 	switch (func_id) {
1695 	case BPF_FUNC_perf_event_output:
1696 		return &bpf_perf_event_output_proto_tp;
1697 	case BPF_FUNC_get_stackid:
1698 		return &bpf_get_stackid_proto_tp;
1699 	case BPF_FUNC_get_stack:
1700 		return &bpf_get_stack_proto_tp;
1701 	case BPF_FUNC_get_attach_cookie:
1702 		return &bpf_get_attach_cookie_proto_trace;
1703 	default:
1704 		return bpf_tracing_func_proto(func_id, prog);
1705 	}
1706 }
1707 
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)1708 static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type,
1709 				    const struct bpf_prog *prog,
1710 				    struct bpf_insn_access_aux *info)
1711 {
1712 	if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE)
1713 		return false;
1714 	if (type != BPF_READ)
1715 		return false;
1716 	if (off % size != 0)
1717 		return false;
1718 
1719 	BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(__u64));
1720 	return true;
1721 }
1722 
1723 const struct bpf_verifier_ops tracepoint_verifier_ops = {
1724 	.get_func_proto  = tp_prog_func_proto,
1725 	.is_valid_access = tp_prog_is_valid_access,
1726 };
1727 
1728 const struct bpf_prog_ops tracepoint_prog_ops = {
1729 };
1730 
BPF_CALL_3(bpf_perf_prog_read_value,struct bpf_perf_event_data_kern *,ctx,struct bpf_perf_event_value *,buf,u32,size)1731 BPF_CALL_3(bpf_perf_prog_read_value, struct bpf_perf_event_data_kern *, ctx,
1732 	   struct bpf_perf_event_value *, buf, u32, size)
1733 {
1734 	int err = -EINVAL;
1735 
1736 	if (unlikely(size != sizeof(struct bpf_perf_event_value)))
1737 		goto clear;
1738 	err = perf_event_read_local(ctx->event, &buf->counter, &buf->enabled,
1739 				    &buf->running);
1740 	if (unlikely(err))
1741 		goto clear;
1742 	return 0;
1743 clear:
1744 	memset(buf, 0, size);
1745 	return err;
1746 }
1747 
1748 static const struct bpf_func_proto bpf_perf_prog_read_value_proto = {
1749          .func           = bpf_perf_prog_read_value,
1750          .gpl_only       = true,
1751          .ret_type       = RET_INTEGER,
1752          .arg1_type      = ARG_PTR_TO_CTX,
1753          .arg2_type      = ARG_PTR_TO_UNINIT_MEM,
1754          .arg3_type      = ARG_CONST_SIZE,
1755 };
1756 
BPF_CALL_4(bpf_read_branch_records,struct bpf_perf_event_data_kern *,ctx,void *,buf,u32,size,u64,flags)1757 BPF_CALL_4(bpf_read_branch_records, struct bpf_perf_event_data_kern *, ctx,
1758 	   void *, buf, u32, size, u64, flags)
1759 {
1760 	static const u32 br_entry_size = sizeof(struct perf_branch_entry);
1761 	struct perf_branch_stack *br_stack = ctx->data->br_stack;
1762 	u32 to_copy;
1763 
1764 	if (unlikely(flags & ~BPF_F_GET_BRANCH_RECORDS_SIZE))
1765 		return -EINVAL;
1766 
1767 	if (unlikely(!(ctx->data->sample_flags & PERF_SAMPLE_BRANCH_STACK)))
1768 		return -ENOENT;
1769 
1770 	if (unlikely(!br_stack))
1771 		return -ENOENT;
1772 
1773 	if (flags & BPF_F_GET_BRANCH_RECORDS_SIZE)
1774 		return br_stack->nr * br_entry_size;
1775 
1776 	if (!buf || (size % br_entry_size != 0))
1777 		return -EINVAL;
1778 
1779 	to_copy = min_t(u32, br_stack->nr * br_entry_size, size);
1780 	memcpy(buf, br_stack->entries, to_copy);
1781 
1782 	return to_copy;
1783 }
1784 
1785 static const struct bpf_func_proto bpf_read_branch_records_proto = {
1786 	.func           = bpf_read_branch_records,
1787 	.gpl_only       = true,
1788 	.ret_type       = RET_INTEGER,
1789 	.arg1_type      = ARG_PTR_TO_CTX,
1790 	.arg2_type      = ARG_PTR_TO_MEM_OR_NULL,
1791 	.arg3_type      = ARG_CONST_SIZE_OR_ZERO,
1792 	.arg4_type      = ARG_ANYTHING,
1793 };
1794 
1795 static const struct bpf_func_proto *
pe_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1796 pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1797 {
1798 	switch (func_id) {
1799 	case BPF_FUNC_perf_event_output:
1800 		return &bpf_perf_event_output_proto_tp;
1801 	case BPF_FUNC_get_stackid:
1802 		return &bpf_get_stackid_proto_pe;
1803 	case BPF_FUNC_get_stack:
1804 		return &bpf_get_stack_proto_pe;
1805 	case BPF_FUNC_perf_prog_read_value:
1806 		return &bpf_perf_prog_read_value_proto;
1807 	case BPF_FUNC_read_branch_records:
1808 		return &bpf_read_branch_records_proto;
1809 	case BPF_FUNC_get_attach_cookie:
1810 		return &bpf_get_attach_cookie_proto_pe;
1811 	default:
1812 		return bpf_tracing_func_proto(func_id, prog);
1813 	}
1814 }
1815 
1816 /*
1817  * bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp
1818  * to avoid potential recursive reuse issue when/if tracepoints are added
1819  * inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack.
1820  *
1821  * Since raw tracepoints run despite bpf_prog_active, support concurrent usage
1822  * in normal, irq, and nmi context.
1823  */
1824 struct bpf_raw_tp_regs {
1825 	struct pt_regs regs[3];
1826 };
1827 static DEFINE_PER_CPU(struct bpf_raw_tp_regs, bpf_raw_tp_regs);
1828 static DEFINE_PER_CPU(int, bpf_raw_tp_nest_level);
get_bpf_raw_tp_regs(void)1829 static struct pt_regs *get_bpf_raw_tp_regs(void)
1830 {
1831 	struct bpf_raw_tp_regs *tp_regs = this_cpu_ptr(&bpf_raw_tp_regs);
1832 	int nest_level = this_cpu_inc_return(bpf_raw_tp_nest_level);
1833 
1834 	if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(tp_regs->regs))) {
1835 		this_cpu_dec(bpf_raw_tp_nest_level);
1836 		return ERR_PTR(-EBUSY);
1837 	}
1838 
1839 	return &tp_regs->regs[nest_level - 1];
1840 }
1841 
put_bpf_raw_tp_regs(void)1842 static void put_bpf_raw_tp_regs(void)
1843 {
1844 	this_cpu_dec(bpf_raw_tp_nest_level);
1845 }
1846 
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)1847 BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args,
1848 	   struct bpf_map *, map, u64, flags, void *, data, u64, size)
1849 {
1850 	struct pt_regs *regs = get_bpf_raw_tp_regs();
1851 	int ret;
1852 
1853 	if (IS_ERR(regs))
1854 		return PTR_ERR(regs);
1855 
1856 	perf_fetch_caller_regs(regs);
1857 	ret = ____bpf_perf_event_output(regs, map, flags, data, size);
1858 
1859 	put_bpf_raw_tp_regs();
1860 	return ret;
1861 }
1862 
1863 static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = {
1864 	.func		= bpf_perf_event_output_raw_tp,
1865 	.gpl_only	= true,
1866 	.ret_type	= RET_INTEGER,
1867 	.arg1_type	= ARG_PTR_TO_CTX,
1868 	.arg2_type	= ARG_CONST_MAP_PTR,
1869 	.arg3_type	= ARG_ANYTHING,
1870 	.arg4_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
1871 	.arg5_type	= ARG_CONST_SIZE_OR_ZERO,
1872 };
1873 
1874 extern const struct bpf_func_proto bpf_skb_output_proto;
1875 extern const struct bpf_func_proto bpf_xdp_output_proto;
1876 extern const struct bpf_func_proto bpf_xdp_get_buff_len_trace_proto;
1877 
BPF_CALL_3(bpf_get_stackid_raw_tp,struct bpf_raw_tracepoint_args *,args,struct bpf_map *,map,u64,flags)1878 BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args,
1879 	   struct bpf_map *, map, u64, flags)
1880 {
1881 	struct pt_regs *regs = get_bpf_raw_tp_regs();
1882 	int ret;
1883 
1884 	if (IS_ERR(regs))
1885 		return PTR_ERR(regs);
1886 
1887 	perf_fetch_caller_regs(regs);
1888 	/* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */
1889 	ret = bpf_get_stackid((unsigned long) regs, (unsigned long) map,
1890 			      flags, 0, 0);
1891 	put_bpf_raw_tp_regs();
1892 	return ret;
1893 }
1894 
1895 static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = {
1896 	.func		= bpf_get_stackid_raw_tp,
1897 	.gpl_only	= true,
1898 	.ret_type	= RET_INTEGER,
1899 	.arg1_type	= ARG_PTR_TO_CTX,
1900 	.arg2_type	= ARG_CONST_MAP_PTR,
1901 	.arg3_type	= ARG_ANYTHING,
1902 };
1903 
BPF_CALL_4(bpf_get_stack_raw_tp,struct bpf_raw_tracepoint_args *,args,void *,buf,u32,size,u64,flags)1904 BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args,
1905 	   void *, buf, u32, size, u64, flags)
1906 {
1907 	struct pt_regs *regs = get_bpf_raw_tp_regs();
1908 	int ret;
1909 
1910 	if (IS_ERR(regs))
1911 		return PTR_ERR(regs);
1912 
1913 	perf_fetch_caller_regs(regs);
1914 	ret = bpf_get_stack((unsigned long) regs, (unsigned long) buf,
1915 			    (unsigned long) size, flags, 0);
1916 	put_bpf_raw_tp_regs();
1917 	return ret;
1918 }
1919 
1920 static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = {
1921 	.func		= bpf_get_stack_raw_tp,
1922 	.gpl_only	= true,
1923 	.ret_type	= RET_INTEGER,
1924 	.arg1_type	= ARG_PTR_TO_CTX,
1925 	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
1926 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
1927 	.arg4_type	= ARG_ANYTHING,
1928 };
1929 
1930 static const struct bpf_func_proto *
raw_tp_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1931 raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1932 {
1933 	switch (func_id) {
1934 	case BPF_FUNC_perf_event_output:
1935 		return &bpf_perf_event_output_proto_raw_tp;
1936 	case BPF_FUNC_get_stackid:
1937 		return &bpf_get_stackid_proto_raw_tp;
1938 	case BPF_FUNC_get_stack:
1939 		return &bpf_get_stack_proto_raw_tp;
1940 	default:
1941 		return bpf_tracing_func_proto(func_id, prog);
1942 	}
1943 }
1944 
1945 const struct bpf_func_proto *
tracing_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1946 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1947 {
1948 	const struct bpf_func_proto *fn;
1949 
1950 	switch (func_id) {
1951 #ifdef CONFIG_NET
1952 	case BPF_FUNC_skb_output:
1953 		return &bpf_skb_output_proto;
1954 	case BPF_FUNC_xdp_output:
1955 		return &bpf_xdp_output_proto;
1956 	case BPF_FUNC_skc_to_tcp6_sock:
1957 		return &bpf_skc_to_tcp6_sock_proto;
1958 	case BPF_FUNC_skc_to_tcp_sock:
1959 		return &bpf_skc_to_tcp_sock_proto;
1960 	case BPF_FUNC_skc_to_tcp_timewait_sock:
1961 		return &bpf_skc_to_tcp_timewait_sock_proto;
1962 	case BPF_FUNC_skc_to_tcp_request_sock:
1963 		return &bpf_skc_to_tcp_request_sock_proto;
1964 	case BPF_FUNC_skc_to_udp6_sock:
1965 		return &bpf_skc_to_udp6_sock_proto;
1966 	case BPF_FUNC_skc_to_unix_sock:
1967 		return &bpf_skc_to_unix_sock_proto;
1968 	case BPF_FUNC_skc_to_mptcp_sock:
1969 		return &bpf_skc_to_mptcp_sock_proto;
1970 	case BPF_FUNC_sk_storage_get:
1971 		return &bpf_sk_storage_get_tracing_proto;
1972 	case BPF_FUNC_sk_storage_delete:
1973 		return &bpf_sk_storage_delete_tracing_proto;
1974 	case BPF_FUNC_sock_from_file:
1975 		return &bpf_sock_from_file_proto;
1976 	case BPF_FUNC_get_socket_cookie:
1977 		return &bpf_get_socket_ptr_cookie_proto;
1978 	case BPF_FUNC_xdp_get_buff_len:
1979 		return &bpf_xdp_get_buff_len_trace_proto;
1980 #endif
1981 	case BPF_FUNC_seq_printf:
1982 		return prog->expected_attach_type == BPF_TRACE_ITER ?
1983 		       &bpf_seq_printf_proto :
1984 		       NULL;
1985 	case BPF_FUNC_seq_write:
1986 		return prog->expected_attach_type == BPF_TRACE_ITER ?
1987 		       &bpf_seq_write_proto :
1988 		       NULL;
1989 	case BPF_FUNC_seq_printf_btf:
1990 		return prog->expected_attach_type == BPF_TRACE_ITER ?
1991 		       &bpf_seq_printf_btf_proto :
1992 		       NULL;
1993 	case BPF_FUNC_d_path:
1994 		return &bpf_d_path_proto;
1995 	case BPF_FUNC_get_func_arg:
1996 		return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_proto : NULL;
1997 	case BPF_FUNC_get_func_ret:
1998 		return bpf_prog_has_trampoline(prog) ? &bpf_get_func_ret_proto : NULL;
1999 	case BPF_FUNC_get_func_arg_cnt:
2000 		return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_cnt_proto : NULL;
2001 	case BPF_FUNC_get_attach_cookie:
2002 		return bpf_prog_has_trampoline(prog) ? &bpf_get_attach_cookie_proto_tracing : NULL;
2003 	default:
2004 		fn = raw_tp_prog_func_proto(func_id, prog);
2005 		if (!fn && prog->expected_attach_type == BPF_TRACE_ITER)
2006 			fn = bpf_iter_get_func_proto(func_id, prog);
2007 		return fn;
2008 	}
2009 }
2010 
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)2011 static bool raw_tp_prog_is_valid_access(int off, int size,
2012 					enum bpf_access_type type,
2013 					const struct bpf_prog *prog,
2014 					struct bpf_insn_access_aux *info)
2015 {
2016 	return bpf_tracing_ctx_access(off, size, type);
2017 }
2018 
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)2019 static bool tracing_prog_is_valid_access(int off, int size,
2020 					 enum bpf_access_type type,
2021 					 const struct bpf_prog *prog,
2022 					 struct bpf_insn_access_aux *info)
2023 {
2024 	return bpf_tracing_btf_ctx_access(off, size, type, prog, info);
2025 }
2026 
bpf_prog_test_run_tracing(struct bpf_prog * prog,const union bpf_attr * kattr,union bpf_attr __user * uattr)2027 int __weak bpf_prog_test_run_tracing(struct bpf_prog *prog,
2028 				     const union bpf_attr *kattr,
2029 				     union bpf_attr __user *uattr)
2030 {
2031 	return -ENOTSUPP;
2032 }
2033 
2034 const struct bpf_verifier_ops raw_tracepoint_verifier_ops = {
2035 	.get_func_proto  = raw_tp_prog_func_proto,
2036 	.is_valid_access = raw_tp_prog_is_valid_access,
2037 };
2038 
2039 const struct bpf_prog_ops raw_tracepoint_prog_ops = {
2040 #ifdef CONFIG_NET
2041 	.test_run = bpf_prog_test_run_raw_tp,
2042 #endif
2043 };
2044 
2045 const struct bpf_verifier_ops tracing_verifier_ops = {
2046 	.get_func_proto  = tracing_prog_func_proto,
2047 	.is_valid_access = tracing_prog_is_valid_access,
2048 };
2049 
2050 const struct bpf_prog_ops tracing_prog_ops = {
2051 	.test_run = bpf_prog_test_run_tracing,
2052 };
2053 
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)2054 static bool raw_tp_writable_prog_is_valid_access(int off, int size,
2055 						 enum bpf_access_type type,
2056 						 const struct bpf_prog *prog,
2057 						 struct bpf_insn_access_aux *info)
2058 {
2059 	if (off == 0) {
2060 		if (size != sizeof(u64) || type != BPF_READ)
2061 			return false;
2062 		info->reg_type = PTR_TO_TP_BUFFER;
2063 	}
2064 	return raw_tp_prog_is_valid_access(off, size, type, prog, info);
2065 }
2066 
2067 const struct bpf_verifier_ops raw_tracepoint_writable_verifier_ops = {
2068 	.get_func_proto  = raw_tp_prog_func_proto,
2069 	.is_valid_access = raw_tp_writable_prog_is_valid_access,
2070 };
2071 
2072 const struct bpf_prog_ops raw_tracepoint_writable_prog_ops = {
2073 };
2074 
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)2075 static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
2076 				    const struct bpf_prog *prog,
2077 				    struct bpf_insn_access_aux *info)
2078 {
2079 	const int size_u64 = sizeof(u64);
2080 
2081 	if (off < 0 || off >= sizeof(struct bpf_perf_event_data))
2082 		return false;
2083 	if (type != BPF_READ)
2084 		return false;
2085 	if (off % size != 0) {
2086 		if (sizeof(unsigned long) != 4)
2087 			return false;
2088 		if (size != 8)
2089 			return false;
2090 		if (off % size != 4)
2091 			return false;
2092 	}
2093 
2094 	switch (off) {
2095 	case bpf_ctx_range(struct bpf_perf_event_data, sample_period):
2096 		bpf_ctx_record_field_size(info, size_u64);
2097 		if (!bpf_ctx_narrow_access_ok(off, size, size_u64))
2098 			return false;
2099 		break;
2100 	case bpf_ctx_range(struct bpf_perf_event_data, addr):
2101 		bpf_ctx_record_field_size(info, size_u64);
2102 		if (!bpf_ctx_narrow_access_ok(off, size, size_u64))
2103 			return false;
2104 		break;
2105 	default:
2106 		if (size != sizeof(long))
2107 			return false;
2108 	}
2109 
2110 	return true;
2111 }
2112 
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)2113 static u32 pe_prog_convert_ctx_access(enum bpf_access_type type,
2114 				      const struct bpf_insn *si,
2115 				      struct bpf_insn *insn_buf,
2116 				      struct bpf_prog *prog, u32 *target_size)
2117 {
2118 	struct bpf_insn *insn = insn_buf;
2119 
2120 	switch (si->off) {
2121 	case offsetof(struct bpf_perf_event_data, sample_period):
2122 		*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
2123 						       data), si->dst_reg, si->src_reg,
2124 				      offsetof(struct bpf_perf_event_data_kern, data));
2125 		*insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg,
2126 				      bpf_target_off(struct perf_sample_data, period, 8,
2127 						     target_size));
2128 		break;
2129 	case offsetof(struct bpf_perf_event_data, addr):
2130 		*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
2131 						       data), si->dst_reg, si->src_reg,
2132 				      offsetof(struct bpf_perf_event_data_kern, data));
2133 		*insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg,
2134 				      bpf_target_off(struct perf_sample_data, addr, 8,
2135 						     target_size));
2136 		break;
2137 	default:
2138 		*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
2139 						       regs), si->dst_reg, si->src_reg,
2140 				      offsetof(struct bpf_perf_event_data_kern, regs));
2141 		*insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg,
2142 				      si->off);
2143 		break;
2144 	}
2145 
2146 	return insn - insn_buf;
2147 }
2148 
2149 const struct bpf_verifier_ops perf_event_verifier_ops = {
2150 	.get_func_proto		= pe_prog_func_proto,
2151 	.is_valid_access	= pe_prog_is_valid_access,
2152 	.convert_ctx_access	= pe_prog_convert_ctx_access,
2153 };
2154 
2155 const struct bpf_prog_ops perf_event_prog_ops = {
2156 };
2157 
2158 static DEFINE_MUTEX(bpf_event_mutex);
2159 
2160 #define BPF_TRACE_MAX_PROGS 64
2161 
perf_event_attach_bpf_prog(struct perf_event * event,struct bpf_prog * prog,u64 bpf_cookie)2162 int perf_event_attach_bpf_prog(struct perf_event *event,
2163 			       struct bpf_prog *prog,
2164 			       u64 bpf_cookie)
2165 {
2166 	struct bpf_prog_array *old_array;
2167 	struct bpf_prog_array *new_array;
2168 	int ret = -EEXIST;
2169 
2170 	/*
2171 	 * Kprobe override only works if they are on the function entry,
2172 	 * and only if they are on the opt-in list.
2173 	 */
2174 	if (prog->kprobe_override &&
2175 	    (!trace_kprobe_on_func_entry(event->tp_event) ||
2176 	     !trace_kprobe_error_injectable(event->tp_event)))
2177 		return -EINVAL;
2178 
2179 	mutex_lock(&bpf_event_mutex);
2180 
2181 	if (event->prog)
2182 		goto unlock;
2183 
2184 	old_array = bpf_event_rcu_dereference(event->tp_event->prog_array);
2185 	if (old_array &&
2186 	    bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) {
2187 		ret = -E2BIG;
2188 		goto unlock;
2189 	}
2190 
2191 	ret = bpf_prog_array_copy(old_array, NULL, prog, bpf_cookie, &new_array);
2192 	if (ret < 0)
2193 		goto unlock;
2194 
2195 	/* set the new array to event->tp_event and set event->prog */
2196 	event->prog = prog;
2197 	event->bpf_cookie = bpf_cookie;
2198 	rcu_assign_pointer(event->tp_event->prog_array, new_array);
2199 	bpf_prog_array_free_sleepable(old_array);
2200 
2201 unlock:
2202 	mutex_unlock(&bpf_event_mutex);
2203 	return ret;
2204 }
2205 
perf_event_detach_bpf_prog(struct perf_event * event)2206 void perf_event_detach_bpf_prog(struct perf_event *event)
2207 {
2208 	struct bpf_prog_array *old_array;
2209 	struct bpf_prog_array *new_array;
2210 	int ret;
2211 
2212 	mutex_lock(&bpf_event_mutex);
2213 
2214 	if (!event->prog)
2215 		goto unlock;
2216 
2217 	old_array = bpf_event_rcu_dereference(event->tp_event->prog_array);
2218 	ret = bpf_prog_array_copy(old_array, event->prog, NULL, 0, &new_array);
2219 	if (ret == -ENOENT)
2220 		goto unlock;
2221 	if (ret < 0) {
2222 		bpf_prog_array_delete_safe(old_array, event->prog);
2223 	} else {
2224 		rcu_assign_pointer(event->tp_event->prog_array, new_array);
2225 		bpf_prog_array_free_sleepable(old_array);
2226 	}
2227 
2228 	bpf_prog_put(event->prog);
2229 	event->prog = NULL;
2230 
2231 unlock:
2232 	mutex_unlock(&bpf_event_mutex);
2233 }
2234 
perf_event_query_prog_array(struct perf_event * event,void __user * info)2235 int perf_event_query_prog_array(struct perf_event *event, void __user *info)
2236 {
2237 	struct perf_event_query_bpf __user *uquery = info;
2238 	struct perf_event_query_bpf query = {};
2239 	struct bpf_prog_array *progs;
2240 	u32 *ids, prog_cnt, ids_len;
2241 	int ret;
2242 
2243 	if (!perfmon_capable())
2244 		return -EPERM;
2245 	if (event->attr.type != PERF_TYPE_TRACEPOINT)
2246 		return -EINVAL;
2247 	if (copy_from_user(&query, uquery, sizeof(query)))
2248 		return -EFAULT;
2249 
2250 	ids_len = query.ids_len;
2251 	if (ids_len > BPF_TRACE_MAX_PROGS)
2252 		return -E2BIG;
2253 	ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN);
2254 	if (!ids)
2255 		return -ENOMEM;
2256 	/*
2257 	 * The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which
2258 	 * is required when user only wants to check for uquery->prog_cnt.
2259 	 * There is no need to check for it since the case is handled
2260 	 * gracefully in bpf_prog_array_copy_info.
2261 	 */
2262 
2263 	mutex_lock(&bpf_event_mutex);
2264 	progs = bpf_event_rcu_dereference(event->tp_event->prog_array);
2265 	ret = bpf_prog_array_copy_info(progs, ids, ids_len, &prog_cnt);
2266 	mutex_unlock(&bpf_event_mutex);
2267 
2268 	if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) ||
2269 	    copy_to_user(uquery->ids, ids, ids_len * sizeof(u32)))
2270 		ret = -EFAULT;
2271 
2272 	kfree(ids);
2273 	return ret;
2274 }
2275 
2276 extern struct bpf_raw_event_map __start__bpf_raw_tp[];
2277 extern struct bpf_raw_event_map __stop__bpf_raw_tp[];
2278 
bpf_get_raw_tracepoint(const char * name)2279 struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name)
2280 {
2281 	struct bpf_raw_event_map *btp = __start__bpf_raw_tp;
2282 
2283 	for (; btp < __stop__bpf_raw_tp; btp++) {
2284 		if (!strcmp(btp->tp->name, name))
2285 			return btp;
2286 	}
2287 
2288 	return bpf_get_raw_tracepoint_module(name);
2289 }
2290 
bpf_put_raw_tracepoint(struct bpf_raw_event_map * btp)2291 void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp)
2292 {
2293 	struct module *mod;
2294 
2295 	preempt_disable();
2296 	mod = __module_address((unsigned long)btp);
2297 	module_put(mod);
2298 	preempt_enable();
2299 }
2300 
2301 static __always_inline
__bpf_trace_run(struct bpf_prog * prog,u64 * args)2302 void __bpf_trace_run(struct bpf_prog *prog, u64 *args)
2303 {
2304 	cant_sleep();
2305 	if (unlikely(this_cpu_inc_return(*(prog->active)) != 1)) {
2306 		bpf_prog_inc_misses_counter(prog);
2307 		goto out;
2308 	}
2309 	rcu_read_lock();
2310 	(void) bpf_prog_run(prog, args);
2311 	rcu_read_unlock();
2312 out:
2313 	this_cpu_dec(*(prog->active));
2314 }
2315 
2316 #define UNPACK(...)			__VA_ARGS__
2317 #define REPEAT_1(FN, DL, X, ...)	FN(X)
2318 #define REPEAT_2(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__)
2319 #define REPEAT_3(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_2(FN, DL, __VA_ARGS__)
2320 #define REPEAT_4(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_3(FN, DL, __VA_ARGS__)
2321 #define REPEAT_5(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_4(FN, DL, __VA_ARGS__)
2322 #define REPEAT_6(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_5(FN, DL, __VA_ARGS__)
2323 #define REPEAT_7(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_6(FN, DL, __VA_ARGS__)
2324 #define REPEAT_8(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_7(FN, DL, __VA_ARGS__)
2325 #define REPEAT_9(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_8(FN, DL, __VA_ARGS__)
2326 #define REPEAT_10(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_9(FN, DL, __VA_ARGS__)
2327 #define REPEAT_11(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_10(FN, DL, __VA_ARGS__)
2328 #define REPEAT_12(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_11(FN, DL, __VA_ARGS__)
2329 #define REPEAT(X, FN, DL, ...)		REPEAT_##X(FN, DL, __VA_ARGS__)
2330 
2331 #define SARG(X)		u64 arg##X
2332 #define COPY(X)		args[X] = arg##X
2333 
2334 #define __DL_COM	(,)
2335 #define __DL_SEM	(;)
2336 
2337 #define __SEQ_0_11	0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11
2338 
2339 #define BPF_TRACE_DEFN_x(x)						\
2340 	void bpf_trace_run##x(struct bpf_prog *prog,			\
2341 			      REPEAT(x, SARG, __DL_COM, __SEQ_0_11))	\
2342 	{								\
2343 		u64 args[x];						\
2344 		REPEAT(x, COPY, __DL_SEM, __SEQ_0_11);			\
2345 		__bpf_trace_run(prog, args);				\
2346 	}								\
2347 	EXPORT_SYMBOL_GPL(bpf_trace_run##x)
2348 BPF_TRACE_DEFN_x(1);
2349 BPF_TRACE_DEFN_x(2);
2350 BPF_TRACE_DEFN_x(3);
2351 BPF_TRACE_DEFN_x(4);
2352 BPF_TRACE_DEFN_x(5);
2353 BPF_TRACE_DEFN_x(6);
2354 BPF_TRACE_DEFN_x(7);
2355 BPF_TRACE_DEFN_x(8);
2356 BPF_TRACE_DEFN_x(9);
2357 BPF_TRACE_DEFN_x(10);
2358 BPF_TRACE_DEFN_x(11);
2359 BPF_TRACE_DEFN_x(12);
2360 
__bpf_probe_register(struct bpf_raw_event_map * btp,struct bpf_prog * prog)2361 static int __bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog)
2362 {
2363 	struct tracepoint *tp = btp->tp;
2364 
2365 	/*
2366 	 * check that program doesn't access arguments beyond what's
2367 	 * available in this tracepoint
2368 	 */
2369 	if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64))
2370 		return -EINVAL;
2371 
2372 	if (prog->aux->max_tp_access > btp->writable_size)
2373 		return -EINVAL;
2374 
2375 	return tracepoint_probe_register_may_exist(tp, (void *)btp->bpf_func,
2376 						   prog);
2377 }
2378 
bpf_probe_register(struct bpf_raw_event_map * btp,struct bpf_prog * prog)2379 int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog)
2380 {
2381 	return __bpf_probe_register(btp, prog);
2382 }
2383 
bpf_probe_unregister(struct bpf_raw_event_map * btp,struct bpf_prog * prog)2384 int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_prog *prog)
2385 {
2386 	return tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, prog);
2387 }
2388 
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)2389 int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id,
2390 			    u32 *fd_type, const char **buf,
2391 			    u64 *probe_offset, u64 *probe_addr)
2392 {
2393 	bool is_tracepoint, is_syscall_tp;
2394 	struct bpf_prog *prog;
2395 	int flags, err = 0;
2396 
2397 	prog = event->prog;
2398 	if (!prog)
2399 		return -ENOENT;
2400 
2401 	/* not supporting BPF_PROG_TYPE_PERF_EVENT yet */
2402 	if (prog->type == BPF_PROG_TYPE_PERF_EVENT)
2403 		return -EOPNOTSUPP;
2404 
2405 	*prog_id = prog->aux->id;
2406 	flags = event->tp_event->flags;
2407 	is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT;
2408 	is_syscall_tp = is_syscall_trace_event(event->tp_event);
2409 
2410 	if (is_tracepoint || is_syscall_tp) {
2411 		*buf = is_tracepoint ? event->tp_event->tp->name
2412 				     : event->tp_event->name;
2413 		/* We allow NULL pointer for tracepoint */
2414 		if (fd_type)
2415 			*fd_type = BPF_FD_TYPE_TRACEPOINT;
2416 		if (probe_offset)
2417 			*probe_offset = 0x0;
2418 		if (probe_addr)
2419 			*probe_addr = 0x0;
2420 	} else {
2421 		/* kprobe/uprobe */
2422 		err = -EOPNOTSUPP;
2423 #ifdef CONFIG_KPROBE_EVENTS
2424 		if (flags & TRACE_EVENT_FL_KPROBE)
2425 			err = bpf_get_kprobe_info(event, fd_type, buf,
2426 						  probe_offset, probe_addr,
2427 						  event->attr.type == PERF_TYPE_TRACEPOINT);
2428 #endif
2429 #ifdef CONFIG_UPROBE_EVENTS
2430 		if (flags & TRACE_EVENT_FL_UPROBE)
2431 			err = bpf_get_uprobe_info(event, fd_type, buf,
2432 						  probe_offset, probe_addr,
2433 						  event->attr.type == PERF_TYPE_TRACEPOINT);
2434 #endif
2435 	}
2436 
2437 	return err;
2438 }
2439 
send_signal_irq_work_init(void)2440 static int __init send_signal_irq_work_init(void)
2441 {
2442 	int cpu;
2443 	struct send_signal_irq_work *work;
2444 
2445 	for_each_possible_cpu(cpu) {
2446 		work = per_cpu_ptr(&send_signal_work, cpu);
2447 		init_irq_work(&work->irq_work, do_bpf_send_signal);
2448 	}
2449 	return 0;
2450 }
2451 
2452 subsys_initcall(send_signal_irq_work_init);
2453 
2454 #ifdef CONFIG_MODULES
bpf_event_notify(struct notifier_block * nb,unsigned long op,void * module)2455 static int bpf_event_notify(struct notifier_block *nb, unsigned long op,
2456 			    void *module)
2457 {
2458 	struct bpf_trace_module *btm, *tmp;
2459 	struct module *mod = module;
2460 	int ret = 0;
2461 
2462 	if (mod->num_bpf_raw_events == 0 ||
2463 	    (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING))
2464 		goto out;
2465 
2466 	mutex_lock(&bpf_module_mutex);
2467 
2468 	switch (op) {
2469 	case MODULE_STATE_COMING:
2470 		btm = kzalloc(sizeof(*btm), GFP_KERNEL);
2471 		if (btm) {
2472 			btm->module = module;
2473 			list_add(&btm->list, &bpf_trace_modules);
2474 		} else {
2475 			ret = -ENOMEM;
2476 		}
2477 		break;
2478 	case MODULE_STATE_GOING:
2479 		list_for_each_entry_safe(btm, tmp, &bpf_trace_modules, list) {
2480 			if (btm->module == module) {
2481 				list_del(&btm->list);
2482 				kfree(btm);
2483 				break;
2484 			}
2485 		}
2486 		break;
2487 	}
2488 
2489 	mutex_unlock(&bpf_module_mutex);
2490 
2491 out:
2492 	return notifier_from_errno(ret);
2493 }
2494 
2495 static struct notifier_block bpf_module_nb = {
2496 	.notifier_call = bpf_event_notify,
2497 };
2498 
bpf_event_init(void)2499 static int __init bpf_event_init(void)
2500 {
2501 	register_module_notifier(&bpf_module_nb);
2502 	return 0;
2503 }
2504 
2505 fs_initcall(bpf_event_init);
2506 #endif /* CONFIG_MODULES */
2507 
2508 #ifdef CONFIG_FPROBE
2509 struct bpf_kprobe_multi_link {
2510 	struct bpf_link link;
2511 	struct fprobe fp;
2512 	unsigned long *addrs;
2513 	u64 *cookies;
2514 	u32 cnt;
2515 	u32 mods_cnt;
2516 	struct module **mods;
2517 	u32 flags;
2518 };
2519 
2520 struct bpf_kprobe_multi_run_ctx {
2521 	struct bpf_run_ctx run_ctx;
2522 	struct bpf_kprobe_multi_link *link;
2523 	unsigned long entry_ip;
2524 };
2525 
2526 struct user_syms {
2527 	const char **syms;
2528 	char *buf;
2529 };
2530 
copy_user_syms(struct user_syms * us,unsigned long __user * usyms,u32 cnt)2531 static int copy_user_syms(struct user_syms *us, unsigned long __user *usyms, u32 cnt)
2532 {
2533 	unsigned long __user usymbol;
2534 	const char **syms = NULL;
2535 	char *buf = NULL, *p;
2536 	int err = -ENOMEM;
2537 	unsigned int i;
2538 
2539 	syms = kvmalloc_array(cnt, sizeof(*syms), GFP_KERNEL);
2540 	if (!syms)
2541 		goto error;
2542 
2543 	buf = kvmalloc_array(cnt, KSYM_NAME_LEN, GFP_KERNEL);
2544 	if (!buf)
2545 		goto error;
2546 
2547 	for (p = buf, i = 0; i < cnt; i++) {
2548 		if (__get_user(usymbol, usyms + i)) {
2549 			err = -EFAULT;
2550 			goto error;
2551 		}
2552 		err = strncpy_from_user(p, (const char __user *) usymbol, KSYM_NAME_LEN);
2553 		if (err == KSYM_NAME_LEN)
2554 			err = -E2BIG;
2555 		if (err < 0)
2556 			goto error;
2557 		syms[i] = p;
2558 		p += err + 1;
2559 	}
2560 
2561 	us->syms = syms;
2562 	us->buf = buf;
2563 	return 0;
2564 
2565 error:
2566 	if (err) {
2567 		kvfree(syms);
2568 		kvfree(buf);
2569 	}
2570 	return err;
2571 }
2572 
kprobe_multi_put_modules(struct module ** mods,u32 cnt)2573 static void kprobe_multi_put_modules(struct module **mods, u32 cnt)
2574 {
2575 	u32 i;
2576 
2577 	for (i = 0; i < cnt; i++)
2578 		module_put(mods[i]);
2579 }
2580 
free_user_syms(struct user_syms * us)2581 static void free_user_syms(struct user_syms *us)
2582 {
2583 	kvfree(us->syms);
2584 	kvfree(us->buf);
2585 }
2586 
bpf_kprobe_multi_link_release(struct bpf_link * link)2587 static void bpf_kprobe_multi_link_release(struct bpf_link *link)
2588 {
2589 	struct bpf_kprobe_multi_link *kmulti_link;
2590 
2591 	kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);
2592 	unregister_fprobe(&kmulti_link->fp);
2593 	kprobe_multi_put_modules(kmulti_link->mods, kmulti_link->mods_cnt);
2594 }
2595 
bpf_kprobe_multi_link_dealloc(struct bpf_link * link)2596 static void bpf_kprobe_multi_link_dealloc(struct bpf_link *link)
2597 {
2598 	struct bpf_kprobe_multi_link *kmulti_link;
2599 
2600 	kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);
2601 	kvfree(kmulti_link->addrs);
2602 	kvfree(kmulti_link->cookies);
2603 	kfree(kmulti_link->mods);
2604 	kfree(kmulti_link);
2605 }
2606 
bpf_kprobe_multi_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)2607 static int bpf_kprobe_multi_link_fill_link_info(const struct bpf_link *link,
2608 						struct bpf_link_info *info)
2609 {
2610 	u64 __user *uaddrs = u64_to_user_ptr(info->kprobe_multi.addrs);
2611 	struct bpf_kprobe_multi_link *kmulti_link;
2612 	u32 ucount = info->kprobe_multi.count;
2613 	int err = 0, i;
2614 
2615 	if (!uaddrs ^ !ucount)
2616 		return -EINVAL;
2617 
2618 	kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);
2619 	info->kprobe_multi.count = kmulti_link->cnt;
2620 	info->kprobe_multi.flags = kmulti_link->flags;
2621 
2622 	if (!uaddrs)
2623 		return 0;
2624 	if (ucount < kmulti_link->cnt)
2625 		err = -ENOSPC;
2626 	else
2627 		ucount = kmulti_link->cnt;
2628 
2629 	if (kallsyms_show_value(current_cred())) {
2630 		if (copy_to_user(uaddrs, kmulti_link->addrs, ucount * sizeof(u64)))
2631 			return -EFAULT;
2632 	} else {
2633 		for (i = 0; i < ucount; i++) {
2634 			if (put_user(0, uaddrs + i))
2635 				return -EFAULT;
2636 		}
2637 	}
2638 	return err;
2639 }
2640 
2641 static const struct bpf_link_ops bpf_kprobe_multi_link_lops = {
2642 	.release = bpf_kprobe_multi_link_release,
2643 	.dealloc_deferred = bpf_kprobe_multi_link_dealloc,
2644 	.fill_link_info = bpf_kprobe_multi_link_fill_link_info,
2645 };
2646 
bpf_kprobe_multi_cookie_swap(void * a,void * b,int size,const void * priv)2647 static void bpf_kprobe_multi_cookie_swap(void *a, void *b, int size, const void *priv)
2648 {
2649 	const struct bpf_kprobe_multi_link *link = priv;
2650 	unsigned long *addr_a = a, *addr_b = b;
2651 	u64 *cookie_a, *cookie_b;
2652 
2653 	cookie_a = link->cookies + (addr_a - link->addrs);
2654 	cookie_b = link->cookies + (addr_b - link->addrs);
2655 
2656 	/* swap addr_a/addr_b and cookie_a/cookie_b values */
2657 	swap(*addr_a, *addr_b);
2658 	swap(*cookie_a, *cookie_b);
2659 }
2660 
bpf_kprobe_multi_addrs_cmp(const void * a,const void * b)2661 static int bpf_kprobe_multi_addrs_cmp(const void *a, const void *b)
2662 {
2663 	const unsigned long *addr_a = a, *addr_b = b;
2664 
2665 	if (*addr_a == *addr_b)
2666 		return 0;
2667 	return *addr_a < *addr_b ? -1 : 1;
2668 }
2669 
bpf_kprobe_multi_cookie_cmp(const void * a,const void * b,const void * priv)2670 static int bpf_kprobe_multi_cookie_cmp(const void *a, const void *b, const void *priv)
2671 {
2672 	return bpf_kprobe_multi_addrs_cmp(a, b);
2673 }
2674 
bpf_kprobe_multi_cookie(struct bpf_run_ctx * ctx)2675 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx)
2676 {
2677 	struct bpf_kprobe_multi_run_ctx *run_ctx;
2678 	struct bpf_kprobe_multi_link *link;
2679 	u64 *cookie, entry_ip;
2680 	unsigned long *addr;
2681 
2682 	if (WARN_ON_ONCE(!ctx))
2683 		return 0;
2684 	run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, run_ctx);
2685 	link = run_ctx->link;
2686 	if (!link->cookies)
2687 		return 0;
2688 	entry_ip = run_ctx->entry_ip;
2689 	addr = bsearch(&entry_ip, link->addrs, link->cnt, sizeof(entry_ip),
2690 		       bpf_kprobe_multi_addrs_cmp);
2691 	if (!addr)
2692 		return 0;
2693 	cookie = link->cookies + (addr - link->addrs);
2694 	return *cookie;
2695 }
2696 
bpf_kprobe_multi_entry_ip(struct bpf_run_ctx * ctx)2697 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
2698 {
2699 	struct bpf_kprobe_multi_run_ctx *run_ctx;
2700 
2701 	run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, run_ctx);
2702 	return run_ctx->entry_ip;
2703 }
2704 
2705 static int
kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link * link,unsigned long entry_ip,struct pt_regs * regs)2706 kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link,
2707 			   unsigned long entry_ip, struct pt_regs *regs)
2708 {
2709 	struct bpf_kprobe_multi_run_ctx run_ctx = {
2710 		.link = link,
2711 		.entry_ip = entry_ip,
2712 	};
2713 	struct bpf_run_ctx *old_run_ctx;
2714 	int err;
2715 
2716 	if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) {
2717 		err = 0;
2718 		goto out;
2719 	}
2720 
2721 	migrate_disable();
2722 	rcu_read_lock();
2723 	old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx);
2724 	err = bpf_prog_run(link->link.prog, regs);
2725 	bpf_reset_run_ctx(old_run_ctx);
2726 	rcu_read_unlock();
2727 	migrate_enable();
2728 
2729  out:
2730 	__this_cpu_dec(bpf_prog_active);
2731 	return err;
2732 }
2733 
2734 static int
kprobe_multi_link_handler(struct fprobe * fp,unsigned long fentry_ip,unsigned long ret_ip,struct pt_regs * regs,void * data)2735 kprobe_multi_link_handler(struct fprobe *fp, unsigned long fentry_ip,
2736 			  unsigned long ret_ip, struct pt_regs *regs,
2737 			  void *data)
2738 {
2739 	struct bpf_kprobe_multi_link *link;
2740 
2741 	link = container_of(fp, struct bpf_kprobe_multi_link, fp);
2742 	kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), regs);
2743 	return 0;
2744 }
2745 
2746 static void
kprobe_multi_link_exit_handler(struct fprobe * fp,unsigned long fentry_ip,unsigned long ret_ip,struct pt_regs * regs,void * data)2747 kprobe_multi_link_exit_handler(struct fprobe *fp, unsigned long fentry_ip,
2748 			       unsigned long ret_ip, struct pt_regs *regs,
2749 			       void *data)
2750 {
2751 	struct bpf_kprobe_multi_link *link;
2752 
2753 	link = container_of(fp, struct bpf_kprobe_multi_link, fp);
2754 	kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), regs);
2755 }
2756 
symbols_cmp_r(const void * a,const void * b,const void * priv)2757 static int symbols_cmp_r(const void *a, const void *b, const void *priv)
2758 {
2759 	const char **str_a = (const char **) a;
2760 	const char **str_b = (const char **) b;
2761 
2762 	return strcmp(*str_a, *str_b);
2763 }
2764 
2765 struct multi_symbols_sort {
2766 	const char **funcs;
2767 	u64 *cookies;
2768 };
2769 
symbols_swap_r(void * a,void * b,int size,const void * priv)2770 static void symbols_swap_r(void *a, void *b, int size, const void *priv)
2771 {
2772 	const struct multi_symbols_sort *data = priv;
2773 	const char **name_a = a, **name_b = b;
2774 
2775 	swap(*name_a, *name_b);
2776 
2777 	/* If defined, swap also related cookies. */
2778 	if (data->cookies) {
2779 		u64 *cookie_a, *cookie_b;
2780 
2781 		cookie_a = data->cookies + (name_a - data->funcs);
2782 		cookie_b = data->cookies + (name_b - data->funcs);
2783 		swap(*cookie_a, *cookie_b);
2784 	}
2785 }
2786 
2787 struct modules_array {
2788 	struct module **mods;
2789 	int mods_cnt;
2790 	int mods_cap;
2791 };
2792 
add_module(struct modules_array * arr,struct module * mod)2793 static int add_module(struct modules_array *arr, struct module *mod)
2794 {
2795 	struct module **mods;
2796 
2797 	if (arr->mods_cnt == arr->mods_cap) {
2798 		arr->mods_cap = max(16, arr->mods_cap * 3 / 2);
2799 		mods = krealloc_array(arr->mods, arr->mods_cap, sizeof(*mods), GFP_KERNEL);
2800 		if (!mods)
2801 			return -ENOMEM;
2802 		arr->mods = mods;
2803 	}
2804 
2805 	arr->mods[arr->mods_cnt] = mod;
2806 	arr->mods_cnt++;
2807 	return 0;
2808 }
2809 
has_module(struct modules_array * arr,struct module * mod)2810 static bool has_module(struct modules_array *arr, struct module *mod)
2811 {
2812 	int i;
2813 
2814 	for (i = arr->mods_cnt - 1; i >= 0; i--) {
2815 		if (arr->mods[i] == mod)
2816 			return true;
2817 	}
2818 	return false;
2819 }
2820 
get_modules_for_addrs(struct module *** mods,unsigned long * addrs,u32 addrs_cnt)2821 static int get_modules_for_addrs(struct module ***mods, unsigned long *addrs, u32 addrs_cnt)
2822 {
2823 	struct modules_array arr = {};
2824 	u32 i, err = 0;
2825 
2826 	for (i = 0; i < addrs_cnt; i++) {
2827 		struct module *mod;
2828 
2829 		preempt_disable();
2830 		mod = __module_address(addrs[i]);
2831 		/* Either no module or we it's already stored  */
2832 		if (!mod || has_module(&arr, mod)) {
2833 			preempt_enable();
2834 			continue;
2835 		}
2836 		if (!try_module_get(mod))
2837 			err = -EINVAL;
2838 		preempt_enable();
2839 		if (err)
2840 			break;
2841 		err = add_module(&arr, mod);
2842 		if (err) {
2843 			module_put(mod);
2844 			break;
2845 		}
2846 	}
2847 
2848 	/* We return either err < 0 in case of error, ... */
2849 	if (err) {
2850 		kprobe_multi_put_modules(arr.mods, arr.mods_cnt);
2851 		kfree(arr.mods);
2852 		return err;
2853 	}
2854 
2855 	/* or number of modules found if everything is ok. */
2856 	*mods = arr.mods;
2857 	return arr.mods_cnt;
2858 }
2859 
addrs_check_error_injection_list(unsigned long * addrs,u32 cnt)2860 static int addrs_check_error_injection_list(unsigned long *addrs, u32 cnt)
2861 {
2862 	u32 i;
2863 
2864 	for (i = 0; i < cnt; i++) {
2865 		if (!within_error_injection_list(addrs[i]))
2866 			return -EINVAL;
2867 	}
2868 	return 0;
2869 }
2870 
bpf_kprobe_multi_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)2871 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
2872 {
2873 	struct bpf_kprobe_multi_link *link = NULL;
2874 	struct bpf_link_primer link_primer;
2875 	void __user *ucookies;
2876 	unsigned long *addrs;
2877 	u32 flags, cnt, size;
2878 	void __user *uaddrs;
2879 	u64 *cookies = NULL;
2880 	void __user *usyms;
2881 	int err;
2882 
2883 	/* no support for 32bit archs yet */
2884 	if (sizeof(u64) != sizeof(void *))
2885 		return -EOPNOTSUPP;
2886 
2887 	if (prog->expected_attach_type != BPF_TRACE_KPROBE_MULTI)
2888 		return -EINVAL;
2889 
2890 	flags = attr->link_create.kprobe_multi.flags;
2891 	if (flags & ~BPF_F_KPROBE_MULTI_RETURN)
2892 		return -EINVAL;
2893 
2894 	uaddrs = u64_to_user_ptr(attr->link_create.kprobe_multi.addrs);
2895 	usyms = u64_to_user_ptr(attr->link_create.kprobe_multi.syms);
2896 	if (!!uaddrs == !!usyms)
2897 		return -EINVAL;
2898 
2899 	cnt = attr->link_create.kprobe_multi.cnt;
2900 	if (!cnt)
2901 		return -EINVAL;
2902 	if (cnt > MAX_KPROBE_MULTI_CNT)
2903 		return -E2BIG;
2904 
2905 	size = cnt * sizeof(*addrs);
2906 	addrs = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL);
2907 	if (!addrs)
2908 		return -ENOMEM;
2909 
2910 	ucookies = u64_to_user_ptr(attr->link_create.kprobe_multi.cookies);
2911 	if (ucookies) {
2912 		cookies = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL);
2913 		if (!cookies) {
2914 			err = -ENOMEM;
2915 			goto error;
2916 		}
2917 		if (copy_from_user(cookies, ucookies, size)) {
2918 			err = -EFAULT;
2919 			goto error;
2920 		}
2921 	}
2922 
2923 	if (uaddrs) {
2924 		if (copy_from_user(addrs, uaddrs, size)) {
2925 			err = -EFAULT;
2926 			goto error;
2927 		}
2928 	} else {
2929 		struct multi_symbols_sort data = {
2930 			.cookies = cookies,
2931 		};
2932 		struct user_syms us;
2933 
2934 		err = copy_user_syms(&us, usyms, cnt);
2935 		if (err)
2936 			goto error;
2937 
2938 		if (cookies)
2939 			data.funcs = us.syms;
2940 
2941 		sort_r(us.syms, cnt, sizeof(*us.syms), symbols_cmp_r,
2942 		       symbols_swap_r, &data);
2943 
2944 		err = ftrace_lookup_symbols(us.syms, cnt, addrs);
2945 		free_user_syms(&us);
2946 		if (err)
2947 			goto error;
2948 	}
2949 
2950 	if (prog->kprobe_override && addrs_check_error_injection_list(addrs, cnt)) {
2951 		err = -EINVAL;
2952 		goto error;
2953 	}
2954 
2955 	link = kzalloc(sizeof(*link), GFP_KERNEL);
2956 	if (!link) {
2957 		err = -ENOMEM;
2958 		goto error;
2959 	}
2960 
2961 	bpf_link_init(&link->link, BPF_LINK_TYPE_KPROBE_MULTI,
2962 		      &bpf_kprobe_multi_link_lops, prog);
2963 
2964 	err = bpf_link_prime(&link->link, &link_primer);
2965 	if (err)
2966 		goto error;
2967 
2968 	if (flags & BPF_F_KPROBE_MULTI_RETURN)
2969 		link->fp.exit_handler = kprobe_multi_link_exit_handler;
2970 	else
2971 		link->fp.entry_handler = kprobe_multi_link_handler;
2972 
2973 	link->addrs = addrs;
2974 	link->cookies = cookies;
2975 	link->cnt = cnt;
2976 	link->flags = flags;
2977 
2978 	if (cookies) {
2979 		/*
2980 		 * Sorting addresses will trigger sorting cookies as well
2981 		 * (check bpf_kprobe_multi_cookie_swap). This way we can
2982 		 * find cookie based on the address in bpf_get_attach_cookie
2983 		 * helper.
2984 		 */
2985 		sort_r(addrs, cnt, sizeof(*addrs),
2986 		       bpf_kprobe_multi_cookie_cmp,
2987 		       bpf_kprobe_multi_cookie_swap,
2988 		       link);
2989 	}
2990 
2991 	err = get_modules_for_addrs(&link->mods, addrs, cnt);
2992 	if (err < 0) {
2993 		bpf_link_cleanup(&link_primer);
2994 		return err;
2995 	}
2996 	link->mods_cnt = err;
2997 
2998 	err = register_fprobe_ips(&link->fp, addrs, cnt);
2999 	if (err) {
3000 		kprobe_multi_put_modules(link->mods, link->mods_cnt);
3001 		bpf_link_cleanup(&link_primer);
3002 		return err;
3003 	}
3004 
3005 	return bpf_link_settle(&link_primer);
3006 
3007 error:
3008 	kfree(link);
3009 	kvfree(addrs);
3010 	kvfree(cookies);
3011 	return err;
3012 }
3013 #else /* !CONFIG_FPROBE */
bpf_kprobe_multi_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)3014 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
3015 {
3016 	return -EOPNOTSUPP;
3017 }
bpf_kprobe_multi_cookie(struct bpf_run_ctx * ctx)3018 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx)
3019 {
3020 	return 0;
3021 }
bpf_kprobe_multi_entry_ip(struct bpf_run_ctx * ctx)3022 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
3023 {
3024 	return 0;
3025 }
3026 #endif
3027 
3028 #ifdef CONFIG_UPROBES
3029 struct bpf_uprobe_multi_link;
3030 
3031 struct bpf_uprobe {
3032 	struct bpf_uprobe_multi_link *link;
3033 	loff_t offset;
3034 	unsigned long ref_ctr_offset;
3035 	u64 cookie;
3036 	struct uprobe_consumer consumer;
3037 };
3038 
3039 struct bpf_uprobe_multi_link {
3040 	struct path path;
3041 	struct bpf_link link;
3042 	u32 cnt;
3043 	struct bpf_uprobe *uprobes;
3044 	struct task_struct *task;
3045 };
3046 
3047 struct bpf_uprobe_multi_run_ctx {
3048 	struct bpf_run_ctx run_ctx;
3049 	unsigned long entry_ip;
3050 	struct bpf_uprobe *uprobe;
3051 };
3052 
bpf_uprobe_unregister(struct path * path,struct bpf_uprobe * uprobes,u32 cnt)3053 static void bpf_uprobe_unregister(struct path *path, struct bpf_uprobe *uprobes,
3054 				  u32 cnt)
3055 {
3056 	u32 i;
3057 
3058 	for (i = 0; i < cnt; i++) {
3059 		uprobe_unregister(d_real_inode(path->dentry), uprobes[i].offset,
3060 				  &uprobes[i].consumer);
3061 	}
3062 }
3063 
bpf_uprobe_multi_link_release(struct bpf_link * link)3064 static void bpf_uprobe_multi_link_release(struct bpf_link *link)
3065 {
3066 	struct bpf_uprobe_multi_link *umulti_link;
3067 
3068 	umulti_link = container_of(link, struct bpf_uprobe_multi_link, link);
3069 	bpf_uprobe_unregister(&umulti_link->path, umulti_link->uprobes, umulti_link->cnt);
3070 	if (umulti_link->task)
3071 		put_task_struct(umulti_link->task);
3072 	path_put(&umulti_link->path);
3073 }
3074 
bpf_uprobe_multi_link_dealloc(struct bpf_link * link)3075 static void bpf_uprobe_multi_link_dealloc(struct bpf_link *link)
3076 {
3077 	struct bpf_uprobe_multi_link *umulti_link;
3078 
3079 	umulti_link = container_of(link, struct bpf_uprobe_multi_link, link);
3080 	kvfree(umulti_link->uprobes);
3081 	kfree(umulti_link);
3082 }
3083 
3084 static const struct bpf_link_ops bpf_uprobe_multi_link_lops = {
3085 	.release = bpf_uprobe_multi_link_release,
3086 	.dealloc_deferred = bpf_uprobe_multi_link_dealloc,
3087 };
3088 
uprobe_prog_run(struct bpf_uprobe * uprobe,unsigned long entry_ip,struct pt_regs * regs)3089 static int uprobe_prog_run(struct bpf_uprobe *uprobe,
3090 			   unsigned long entry_ip,
3091 			   struct pt_regs *regs)
3092 {
3093 	struct bpf_uprobe_multi_link *link = uprobe->link;
3094 	struct bpf_uprobe_multi_run_ctx run_ctx = {
3095 		.entry_ip = entry_ip,
3096 		.uprobe = uprobe,
3097 	};
3098 	struct bpf_prog *prog = link->link.prog;
3099 	bool sleepable = prog->aux->sleepable;
3100 	struct bpf_run_ctx *old_run_ctx;
3101 	int err = 0;
3102 
3103 	if (link->task && current->mm != link->task->mm)
3104 		return 0;
3105 
3106 	if (sleepable)
3107 		rcu_read_lock_trace();
3108 	else
3109 		rcu_read_lock();
3110 
3111 	migrate_disable();
3112 
3113 	old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx);
3114 	err = bpf_prog_run(link->link.prog, regs);
3115 	bpf_reset_run_ctx(old_run_ctx);
3116 
3117 	migrate_enable();
3118 
3119 	if (sleepable)
3120 		rcu_read_unlock_trace();
3121 	else
3122 		rcu_read_unlock();
3123 	return err;
3124 }
3125 
3126 static bool
uprobe_multi_link_filter(struct uprobe_consumer * con,enum uprobe_filter_ctx ctx,struct mm_struct * mm)3127 uprobe_multi_link_filter(struct uprobe_consumer *con, enum uprobe_filter_ctx ctx,
3128 			 struct mm_struct *mm)
3129 {
3130 	struct bpf_uprobe *uprobe;
3131 
3132 	uprobe = container_of(con, struct bpf_uprobe, consumer);
3133 	return uprobe->link->task->mm == mm;
3134 }
3135 
3136 static int
uprobe_multi_link_handler(struct uprobe_consumer * con,struct pt_regs * regs)3137 uprobe_multi_link_handler(struct uprobe_consumer *con, struct pt_regs *regs)
3138 {
3139 	struct bpf_uprobe *uprobe;
3140 
3141 	uprobe = container_of(con, struct bpf_uprobe, consumer);
3142 	return uprobe_prog_run(uprobe, instruction_pointer(regs), regs);
3143 }
3144 
3145 static int
uprobe_multi_link_ret_handler(struct uprobe_consumer * con,unsigned long func,struct pt_regs * regs)3146 uprobe_multi_link_ret_handler(struct uprobe_consumer *con, unsigned long func, struct pt_regs *regs)
3147 {
3148 	struct bpf_uprobe *uprobe;
3149 
3150 	uprobe = container_of(con, struct bpf_uprobe, consumer);
3151 	return uprobe_prog_run(uprobe, func, regs);
3152 }
3153 
bpf_uprobe_multi_entry_ip(struct bpf_run_ctx * ctx)3154 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
3155 {
3156 	struct bpf_uprobe_multi_run_ctx *run_ctx;
3157 
3158 	run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx, run_ctx);
3159 	return run_ctx->entry_ip;
3160 }
3161 
bpf_uprobe_multi_cookie(struct bpf_run_ctx * ctx)3162 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx)
3163 {
3164 	struct bpf_uprobe_multi_run_ctx *run_ctx;
3165 
3166 	run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx, run_ctx);
3167 	return run_ctx->uprobe->cookie;
3168 }
3169 
bpf_uprobe_multi_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)3170 int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
3171 {
3172 	struct bpf_uprobe_multi_link *link = NULL;
3173 	unsigned long __user *uref_ctr_offsets;
3174 	struct bpf_link_primer link_primer;
3175 	struct bpf_uprobe *uprobes = NULL;
3176 	struct task_struct *task = NULL;
3177 	unsigned long __user *uoffsets;
3178 	u64 __user *ucookies;
3179 	void __user *upath;
3180 	u32 flags, cnt, i;
3181 	struct path path;
3182 	char *name;
3183 	pid_t pid;
3184 	int err;
3185 
3186 	/* no support for 32bit archs yet */
3187 	if (sizeof(u64) != sizeof(void *))
3188 		return -EOPNOTSUPP;
3189 
3190 	if (prog->expected_attach_type != BPF_TRACE_UPROBE_MULTI)
3191 		return -EINVAL;
3192 
3193 	flags = attr->link_create.uprobe_multi.flags;
3194 	if (flags & ~BPF_F_UPROBE_MULTI_RETURN)
3195 		return -EINVAL;
3196 
3197 	/*
3198 	 * path, offsets and cnt are mandatory,
3199 	 * ref_ctr_offsets and cookies are optional
3200 	 */
3201 	upath = u64_to_user_ptr(attr->link_create.uprobe_multi.path);
3202 	uoffsets = u64_to_user_ptr(attr->link_create.uprobe_multi.offsets);
3203 	cnt = attr->link_create.uprobe_multi.cnt;
3204 	pid = attr->link_create.uprobe_multi.pid;
3205 
3206 	if (!upath || !uoffsets || !cnt || pid < 0)
3207 		return -EINVAL;
3208 	if (cnt > MAX_UPROBE_MULTI_CNT)
3209 		return -E2BIG;
3210 
3211 	uref_ctr_offsets = u64_to_user_ptr(attr->link_create.uprobe_multi.ref_ctr_offsets);
3212 	ucookies = u64_to_user_ptr(attr->link_create.uprobe_multi.cookies);
3213 
3214 	name = strndup_user(upath, PATH_MAX);
3215 	if (IS_ERR(name)) {
3216 		err = PTR_ERR(name);
3217 		return err;
3218 	}
3219 
3220 	err = kern_path(name, LOOKUP_FOLLOW, &path);
3221 	kfree(name);
3222 	if (err)
3223 		return err;
3224 
3225 	if (!d_is_reg(path.dentry)) {
3226 		err = -EBADF;
3227 		goto error_path_put;
3228 	}
3229 
3230 	if (pid) {
3231 		rcu_read_lock();
3232 		task = get_pid_task(find_vpid(pid), PIDTYPE_TGID);
3233 		rcu_read_unlock();
3234 		if (!task) {
3235 			err = -ESRCH;
3236 			goto error_path_put;
3237 		}
3238 	}
3239 
3240 	err = -ENOMEM;
3241 
3242 	link = kzalloc(sizeof(*link), GFP_KERNEL);
3243 	uprobes = kvcalloc(cnt, sizeof(*uprobes), GFP_KERNEL);
3244 
3245 	if (!uprobes || !link)
3246 		goto error_free;
3247 
3248 	for (i = 0; i < cnt; i++) {
3249 		if (ucookies && __get_user(uprobes[i].cookie, ucookies + i)) {
3250 			err = -EFAULT;
3251 			goto error_free;
3252 		}
3253 		if (uref_ctr_offsets && __get_user(uprobes[i].ref_ctr_offset, uref_ctr_offsets + i)) {
3254 			err = -EFAULT;
3255 			goto error_free;
3256 		}
3257 		if (__get_user(uprobes[i].offset, uoffsets + i)) {
3258 			err = -EFAULT;
3259 			goto error_free;
3260 		}
3261 
3262 		uprobes[i].link = link;
3263 
3264 		if (flags & BPF_F_UPROBE_MULTI_RETURN)
3265 			uprobes[i].consumer.ret_handler = uprobe_multi_link_ret_handler;
3266 		else
3267 			uprobes[i].consumer.handler = uprobe_multi_link_handler;
3268 
3269 		if (pid)
3270 			uprobes[i].consumer.filter = uprobe_multi_link_filter;
3271 	}
3272 
3273 	link->cnt = cnt;
3274 	link->uprobes = uprobes;
3275 	link->path = path;
3276 	link->task = task;
3277 
3278 	bpf_link_init(&link->link, BPF_LINK_TYPE_UPROBE_MULTI,
3279 		      &bpf_uprobe_multi_link_lops, prog);
3280 
3281 	for (i = 0; i < cnt; i++) {
3282 		err = uprobe_register_refctr(d_real_inode(link->path.dentry),
3283 					     uprobes[i].offset,
3284 					     uprobes[i].ref_ctr_offset,
3285 					     &uprobes[i].consumer);
3286 		if (err) {
3287 			bpf_uprobe_unregister(&path, uprobes, i);
3288 			goto error_free;
3289 		}
3290 	}
3291 
3292 	err = bpf_link_prime(&link->link, &link_primer);
3293 	if (err)
3294 		goto error_free;
3295 
3296 	return bpf_link_settle(&link_primer);
3297 
3298 error_free:
3299 	kvfree(uprobes);
3300 	kfree(link);
3301 	if (task)
3302 		put_task_struct(task);
3303 error_path_put:
3304 	path_put(&path);
3305 	return err;
3306 }
3307 #else /* !CONFIG_UPROBES */
bpf_uprobe_multi_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)3308 int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
3309 {
3310 	return -EOPNOTSUPP;
3311 }
bpf_uprobe_multi_cookie(struct bpf_run_ctx * ctx)3312 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx)
3313 {
3314 	return 0;
3315 }
bpf_uprobe_multi_entry_ip(struct bpf_run_ctx * ctx)3316 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
3317 {
3318 	return 0;
3319 }
3320 #endif /* CONFIG_UPROBES */
3321