xref: /openbmc/linux/kernel/trace/bpf_trace.c (revision 44ad3baf1cca483e418b6aadf2d3994f69e0f16a)
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(struct work_struct * work)403 static void __set_printk_clr_event(struct work_struct *work)
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 static DECLARE_WORK(set_printk_work, __set_printk_clr_event);
417 
bpf_get_trace_printk_proto(void)418 const struct bpf_func_proto *bpf_get_trace_printk_proto(void)
419 {
420 	schedule_work(&set_printk_work);
421 	return &bpf_trace_printk_proto;
422 }
423 
BPF_CALL_4(bpf_trace_vprintk,char *,fmt,u32,fmt_size,const void *,args,u32,data_len)424 BPF_CALL_4(bpf_trace_vprintk, char *, fmt, u32, fmt_size, const void *, args,
425 	   u32, data_len)
426 {
427 	struct bpf_bprintf_data data = {
428 		.get_bin_args	= true,
429 		.get_buf	= true,
430 	};
431 	int ret, num_args;
432 
433 	if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 ||
434 	    (data_len && !args))
435 		return -EINVAL;
436 	num_args = data_len / 8;
437 
438 	ret = bpf_bprintf_prepare(fmt, fmt_size, args, num_args, &data);
439 	if (ret < 0)
440 		return ret;
441 
442 	ret = bstr_printf(data.buf, MAX_BPRINTF_BUF, fmt, data.bin_args);
443 
444 	trace_bpf_trace_printk(data.buf);
445 
446 	bpf_bprintf_cleanup(&data);
447 
448 	return ret;
449 }
450 
451 static const struct bpf_func_proto bpf_trace_vprintk_proto = {
452 	.func		= bpf_trace_vprintk,
453 	.gpl_only	= true,
454 	.ret_type	= RET_INTEGER,
455 	.arg1_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
456 	.arg2_type	= ARG_CONST_SIZE,
457 	.arg3_type	= ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY,
458 	.arg4_type	= ARG_CONST_SIZE_OR_ZERO,
459 };
460 
bpf_get_trace_vprintk_proto(void)461 const struct bpf_func_proto *bpf_get_trace_vprintk_proto(void)
462 {
463 	schedule_work(&set_printk_work);
464 	return &bpf_trace_vprintk_proto;
465 }
466 
BPF_CALL_5(bpf_seq_printf,struct seq_file *,m,char *,fmt,u32,fmt_size,const void *,args,u32,data_len)467 BPF_CALL_5(bpf_seq_printf, struct seq_file *, m, char *, fmt, u32, fmt_size,
468 	   const void *, args, u32, data_len)
469 {
470 	struct bpf_bprintf_data data = {
471 		.get_bin_args	= true,
472 	};
473 	int err, num_args;
474 
475 	if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 ||
476 	    (data_len && !args))
477 		return -EINVAL;
478 	num_args = data_len / 8;
479 
480 	err = bpf_bprintf_prepare(fmt, fmt_size, args, num_args, &data);
481 	if (err < 0)
482 		return err;
483 
484 	seq_bprintf(m, fmt, data.bin_args);
485 
486 	bpf_bprintf_cleanup(&data);
487 
488 	return seq_has_overflowed(m) ? -EOVERFLOW : 0;
489 }
490 
491 BTF_ID_LIST_SINGLE(btf_seq_file_ids, struct, seq_file)
492 
493 static const struct bpf_func_proto bpf_seq_printf_proto = {
494 	.func		= bpf_seq_printf,
495 	.gpl_only	= true,
496 	.ret_type	= RET_INTEGER,
497 	.arg1_type	= ARG_PTR_TO_BTF_ID,
498 	.arg1_btf_id	= &btf_seq_file_ids[0],
499 	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
500 	.arg3_type	= ARG_CONST_SIZE,
501 	.arg4_type      = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY,
502 	.arg5_type      = ARG_CONST_SIZE_OR_ZERO,
503 };
504 
BPF_CALL_3(bpf_seq_write,struct seq_file *,m,const void *,data,u32,len)505 BPF_CALL_3(bpf_seq_write, struct seq_file *, m, const void *, data, u32, len)
506 {
507 	return seq_write(m, data, len) ? -EOVERFLOW : 0;
508 }
509 
510 static const struct bpf_func_proto bpf_seq_write_proto = {
511 	.func		= bpf_seq_write,
512 	.gpl_only	= true,
513 	.ret_type	= RET_INTEGER,
514 	.arg1_type	= ARG_PTR_TO_BTF_ID,
515 	.arg1_btf_id	= &btf_seq_file_ids[0],
516 	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
517 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
518 };
519 
BPF_CALL_4(bpf_seq_printf_btf,struct seq_file *,m,struct btf_ptr *,ptr,u32,btf_ptr_size,u64,flags)520 BPF_CALL_4(bpf_seq_printf_btf, struct seq_file *, m, struct btf_ptr *, ptr,
521 	   u32, btf_ptr_size, u64, flags)
522 {
523 	const struct btf *btf;
524 	s32 btf_id;
525 	int ret;
526 
527 	ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id);
528 	if (ret)
529 		return ret;
530 
531 	return btf_type_seq_show_flags(btf, btf_id, ptr->ptr, m, flags);
532 }
533 
534 static const struct bpf_func_proto bpf_seq_printf_btf_proto = {
535 	.func		= bpf_seq_printf_btf,
536 	.gpl_only	= true,
537 	.ret_type	= RET_INTEGER,
538 	.arg1_type	= ARG_PTR_TO_BTF_ID,
539 	.arg1_btf_id	= &btf_seq_file_ids[0],
540 	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
541 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
542 	.arg4_type	= ARG_ANYTHING,
543 };
544 
545 static __always_inline int
get_map_perf_counter(struct bpf_map * map,u64 flags,u64 * value,u64 * enabled,u64 * running)546 get_map_perf_counter(struct bpf_map *map, u64 flags,
547 		     u64 *value, u64 *enabled, u64 *running)
548 {
549 	struct bpf_array *array = container_of(map, struct bpf_array, map);
550 	unsigned int cpu = smp_processor_id();
551 	u64 index = flags & BPF_F_INDEX_MASK;
552 	struct bpf_event_entry *ee;
553 
554 	if (unlikely(flags & ~(BPF_F_INDEX_MASK)))
555 		return -EINVAL;
556 	if (index == BPF_F_CURRENT_CPU)
557 		index = cpu;
558 	if (unlikely(index >= array->map.max_entries))
559 		return -E2BIG;
560 
561 	ee = READ_ONCE(array->ptrs[index]);
562 	if (!ee)
563 		return -ENOENT;
564 
565 	return perf_event_read_local(ee->event, value, enabled, running);
566 }
567 
BPF_CALL_2(bpf_perf_event_read,struct bpf_map *,map,u64,flags)568 BPF_CALL_2(bpf_perf_event_read, struct bpf_map *, map, u64, flags)
569 {
570 	u64 value = 0;
571 	int err;
572 
573 	err = get_map_perf_counter(map, flags, &value, NULL, NULL);
574 	/*
575 	 * this api is ugly since we miss [-22..-2] range of valid
576 	 * counter values, but that's uapi
577 	 */
578 	if (err)
579 		return err;
580 	return value;
581 }
582 
583 static const struct bpf_func_proto bpf_perf_event_read_proto = {
584 	.func		= bpf_perf_event_read,
585 	.gpl_only	= true,
586 	.ret_type	= RET_INTEGER,
587 	.arg1_type	= ARG_CONST_MAP_PTR,
588 	.arg2_type	= ARG_ANYTHING,
589 };
590 
BPF_CALL_4(bpf_perf_event_read_value,struct bpf_map *,map,u64,flags,struct bpf_perf_event_value *,buf,u32,size)591 BPF_CALL_4(bpf_perf_event_read_value, struct bpf_map *, map, u64, flags,
592 	   struct bpf_perf_event_value *, buf, u32, size)
593 {
594 	int err = -EINVAL;
595 
596 	if (unlikely(size != sizeof(struct bpf_perf_event_value)))
597 		goto clear;
598 	err = get_map_perf_counter(map, flags, &buf->counter, &buf->enabled,
599 				   &buf->running);
600 	if (unlikely(err))
601 		goto clear;
602 	return 0;
603 clear:
604 	memset(buf, 0, size);
605 	return err;
606 }
607 
608 static const struct bpf_func_proto bpf_perf_event_read_value_proto = {
609 	.func		= bpf_perf_event_read_value,
610 	.gpl_only	= true,
611 	.ret_type	= RET_INTEGER,
612 	.arg1_type	= ARG_CONST_MAP_PTR,
613 	.arg2_type	= ARG_ANYTHING,
614 	.arg3_type	= ARG_PTR_TO_UNINIT_MEM,
615 	.arg4_type	= ARG_CONST_SIZE,
616 };
617 
618 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)619 __bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map,
620 			u64 flags, struct perf_raw_record *raw,
621 			struct perf_sample_data *sd)
622 {
623 	struct bpf_array *array = container_of(map, struct bpf_array, map);
624 	unsigned int cpu = smp_processor_id();
625 	u64 index = flags & BPF_F_INDEX_MASK;
626 	struct bpf_event_entry *ee;
627 	struct perf_event *event;
628 
629 	if (index == BPF_F_CURRENT_CPU)
630 		index = cpu;
631 	if (unlikely(index >= array->map.max_entries))
632 		return -E2BIG;
633 
634 	ee = READ_ONCE(array->ptrs[index]);
635 	if (!ee)
636 		return -ENOENT;
637 
638 	event = ee->event;
639 	if (unlikely(event->attr.type != PERF_TYPE_SOFTWARE ||
640 		     event->attr.config != PERF_COUNT_SW_BPF_OUTPUT))
641 		return -EINVAL;
642 
643 	if (unlikely(event->oncpu != cpu))
644 		return -EOPNOTSUPP;
645 
646 	perf_sample_save_raw_data(sd, event, raw);
647 
648 	return perf_event_output(event, sd, regs);
649 }
650 
651 /*
652  * Support executing tracepoints in normal, irq, and nmi context that each call
653  * bpf_perf_event_output
654  */
655 struct bpf_trace_sample_data {
656 	struct perf_sample_data sds[3];
657 };
658 
659 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_trace_sds);
660 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)661 BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map,
662 	   u64, flags, void *, data, u64, size)
663 {
664 	struct bpf_trace_sample_data *sds;
665 	struct perf_raw_record raw = {
666 		.frag = {
667 			.size = size,
668 			.data = data,
669 		},
670 	};
671 	struct perf_sample_data *sd;
672 	int nest_level, err;
673 
674 	preempt_disable();
675 	sds = this_cpu_ptr(&bpf_trace_sds);
676 	nest_level = this_cpu_inc_return(bpf_trace_nest_level);
677 
678 	if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(sds->sds))) {
679 		err = -EBUSY;
680 		goto out;
681 	}
682 
683 	sd = &sds->sds[nest_level - 1];
684 
685 	if (unlikely(flags & ~(BPF_F_INDEX_MASK))) {
686 		err = -EINVAL;
687 		goto out;
688 	}
689 
690 	perf_sample_data_init(sd, 0, 0);
691 
692 	err = __bpf_perf_event_output(regs, map, flags, &raw, sd);
693 out:
694 	this_cpu_dec(bpf_trace_nest_level);
695 	preempt_enable();
696 	return err;
697 }
698 
699 static const struct bpf_func_proto bpf_perf_event_output_proto = {
700 	.func		= bpf_perf_event_output,
701 	.gpl_only	= true,
702 	.ret_type	= RET_INTEGER,
703 	.arg1_type	= ARG_PTR_TO_CTX,
704 	.arg2_type	= ARG_CONST_MAP_PTR,
705 	.arg3_type	= ARG_ANYTHING,
706 	.arg4_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
707 	.arg5_type	= ARG_CONST_SIZE_OR_ZERO,
708 };
709 
710 static DEFINE_PER_CPU(int, bpf_event_output_nest_level);
711 struct bpf_nested_pt_regs {
712 	struct pt_regs regs[3];
713 };
714 static DEFINE_PER_CPU(struct bpf_nested_pt_regs, bpf_pt_regs);
715 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_misc_sds);
716 
bpf_event_output(struct bpf_map * map,u64 flags,void * meta,u64 meta_size,void * ctx,u64 ctx_size,bpf_ctx_copy_t ctx_copy)717 u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
718 		     void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy)
719 {
720 	struct perf_raw_frag frag = {
721 		.copy		= ctx_copy,
722 		.size		= ctx_size,
723 		.data		= ctx,
724 	};
725 	struct perf_raw_record raw = {
726 		.frag = {
727 			{
728 				.next	= ctx_size ? &frag : NULL,
729 			},
730 			.size	= meta_size,
731 			.data	= meta,
732 		},
733 	};
734 	struct perf_sample_data *sd;
735 	struct pt_regs *regs;
736 	int nest_level;
737 	u64 ret;
738 
739 	preempt_disable();
740 	nest_level = this_cpu_inc_return(bpf_event_output_nest_level);
741 
742 	if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(bpf_misc_sds.sds))) {
743 		ret = -EBUSY;
744 		goto out;
745 	}
746 	sd = this_cpu_ptr(&bpf_misc_sds.sds[nest_level - 1]);
747 	regs = this_cpu_ptr(&bpf_pt_regs.regs[nest_level - 1]);
748 
749 	perf_fetch_caller_regs(regs);
750 	perf_sample_data_init(sd, 0, 0);
751 
752 	ret = __bpf_perf_event_output(regs, map, flags, &raw, sd);
753 out:
754 	this_cpu_dec(bpf_event_output_nest_level);
755 	preempt_enable();
756 	return ret;
757 }
758 
BPF_CALL_0(bpf_get_current_task)759 BPF_CALL_0(bpf_get_current_task)
760 {
761 	return (long) current;
762 }
763 
764 const struct bpf_func_proto bpf_get_current_task_proto = {
765 	.func		= bpf_get_current_task,
766 	.gpl_only	= true,
767 	.ret_type	= RET_INTEGER,
768 };
769 
BPF_CALL_0(bpf_get_current_task_btf)770 BPF_CALL_0(bpf_get_current_task_btf)
771 {
772 	return (unsigned long) current;
773 }
774 
775 const struct bpf_func_proto bpf_get_current_task_btf_proto = {
776 	.func		= bpf_get_current_task_btf,
777 	.gpl_only	= true,
778 	.ret_type	= RET_PTR_TO_BTF_ID_TRUSTED,
779 	.ret_btf_id	= &btf_tracing_ids[BTF_TRACING_TYPE_TASK],
780 };
781 
BPF_CALL_1(bpf_task_pt_regs,struct task_struct *,task)782 BPF_CALL_1(bpf_task_pt_regs, struct task_struct *, task)
783 {
784 	return (unsigned long) task_pt_regs(task);
785 }
786 
787 BTF_ID_LIST(bpf_task_pt_regs_ids)
788 BTF_ID(struct, pt_regs)
789 
790 const struct bpf_func_proto bpf_task_pt_regs_proto = {
791 	.func		= bpf_task_pt_regs,
792 	.gpl_only	= true,
793 	.arg1_type	= ARG_PTR_TO_BTF_ID,
794 	.arg1_btf_id	= &btf_tracing_ids[BTF_TRACING_TYPE_TASK],
795 	.ret_type	= RET_PTR_TO_BTF_ID,
796 	.ret_btf_id	= &bpf_task_pt_regs_ids[0],
797 };
798 
BPF_CALL_2(bpf_current_task_under_cgroup,struct bpf_map *,map,u32,idx)799 BPF_CALL_2(bpf_current_task_under_cgroup, struct bpf_map *, map, u32, idx)
800 {
801 	struct bpf_array *array = container_of(map, struct bpf_array, map);
802 	struct cgroup *cgrp;
803 
804 	if (unlikely(idx >= array->map.max_entries))
805 		return -E2BIG;
806 
807 	cgrp = READ_ONCE(array->ptrs[idx]);
808 	if (unlikely(!cgrp))
809 		return -EAGAIN;
810 
811 	return task_under_cgroup_hierarchy(current, cgrp);
812 }
813 
814 static const struct bpf_func_proto bpf_current_task_under_cgroup_proto = {
815 	.func           = bpf_current_task_under_cgroup,
816 	.gpl_only       = false,
817 	.ret_type       = RET_INTEGER,
818 	.arg1_type      = ARG_CONST_MAP_PTR,
819 	.arg2_type      = ARG_ANYTHING,
820 };
821 
822 struct send_signal_irq_work {
823 	struct irq_work irq_work;
824 	struct task_struct *task;
825 	u32 sig;
826 	enum pid_type type;
827 };
828 
829 static DEFINE_PER_CPU(struct send_signal_irq_work, send_signal_work);
830 
do_bpf_send_signal(struct irq_work * entry)831 static void do_bpf_send_signal(struct irq_work *entry)
832 {
833 	struct send_signal_irq_work *work;
834 
835 	work = container_of(entry, struct send_signal_irq_work, irq_work);
836 	group_send_sig_info(work->sig, SEND_SIG_PRIV, work->task, work->type);
837 	put_task_struct(work->task);
838 }
839 
bpf_send_signal_common(u32 sig,enum pid_type type)840 static int bpf_send_signal_common(u32 sig, enum pid_type type)
841 {
842 	struct send_signal_irq_work *work = NULL;
843 
844 	/* Similar to bpf_probe_write_user, task needs to be
845 	 * in a sound condition and kernel memory access be
846 	 * permitted in order to send signal to the current
847 	 * task.
848 	 */
849 	if (unlikely(current->flags & (PF_KTHREAD | PF_EXITING)))
850 		return -EPERM;
851 	if (unlikely(!nmi_uaccess_okay()))
852 		return -EPERM;
853 	/* Task should not be pid=1 to avoid kernel panic. */
854 	if (unlikely(is_global_init(current)))
855 		return -EPERM;
856 
857 	if (preempt_count() != 0 || irqs_disabled()) {
858 		/* Do an early check on signal validity. Otherwise,
859 		 * the error is lost in deferred irq_work.
860 		 */
861 		if (unlikely(!valid_signal(sig)))
862 			return -EINVAL;
863 
864 		work = this_cpu_ptr(&send_signal_work);
865 		if (irq_work_is_busy(&work->irq_work))
866 			return -EBUSY;
867 
868 		/* Add the current task, which is the target of sending signal,
869 		 * to the irq_work. The current task may change when queued
870 		 * irq works get executed.
871 		 */
872 		work->task = get_task_struct(current);
873 		work->sig = sig;
874 		work->type = type;
875 		irq_work_queue(&work->irq_work);
876 		return 0;
877 	}
878 
879 	return group_send_sig_info(sig, SEND_SIG_PRIV, current, type);
880 }
881 
BPF_CALL_1(bpf_send_signal,u32,sig)882 BPF_CALL_1(bpf_send_signal, u32, sig)
883 {
884 	return bpf_send_signal_common(sig, PIDTYPE_TGID);
885 }
886 
887 static const struct bpf_func_proto bpf_send_signal_proto = {
888 	.func		= bpf_send_signal,
889 	.gpl_only	= false,
890 	.ret_type	= RET_INTEGER,
891 	.arg1_type	= ARG_ANYTHING,
892 };
893 
BPF_CALL_1(bpf_send_signal_thread,u32,sig)894 BPF_CALL_1(bpf_send_signal_thread, u32, sig)
895 {
896 	return bpf_send_signal_common(sig, PIDTYPE_PID);
897 }
898 
899 static const struct bpf_func_proto bpf_send_signal_thread_proto = {
900 	.func		= bpf_send_signal_thread,
901 	.gpl_only	= false,
902 	.ret_type	= RET_INTEGER,
903 	.arg1_type	= ARG_ANYTHING,
904 };
905 
BPF_CALL_3(bpf_d_path,struct path *,path,char *,buf,u32,sz)906 BPF_CALL_3(bpf_d_path, struct path *, path, char *, buf, u32, sz)
907 {
908 	struct path copy;
909 	long len;
910 	char *p;
911 
912 	if (!sz)
913 		return 0;
914 
915 	/*
916 	 * The path pointer is verified as trusted and safe to use,
917 	 * but let's double check it's valid anyway to workaround
918 	 * potentially broken verifier.
919 	 */
920 	len = copy_from_kernel_nofault(&copy, path, sizeof(*path));
921 	if (len < 0)
922 		return len;
923 
924 	p = d_path(&copy, buf, sz);
925 	if (IS_ERR(p)) {
926 		len = PTR_ERR(p);
927 	} else {
928 		len = buf + sz - p;
929 		memmove(buf, p, len);
930 	}
931 
932 	return len;
933 }
934 
935 BTF_SET_START(btf_allowlist_d_path)
936 #ifdef CONFIG_SECURITY
BTF_ID(func,security_file_permission)937 BTF_ID(func, security_file_permission)
938 BTF_ID(func, security_inode_getattr)
939 BTF_ID(func, security_file_open)
940 #endif
941 #ifdef CONFIG_SECURITY_PATH
942 BTF_ID(func, security_path_truncate)
943 #endif
944 BTF_ID(func, vfs_truncate)
945 BTF_ID(func, vfs_fallocate)
946 BTF_ID(func, dentry_open)
947 BTF_ID(func, vfs_getattr)
948 BTF_ID(func, filp_close)
949 BTF_SET_END(btf_allowlist_d_path)
950 
951 static bool bpf_d_path_allowed(const struct bpf_prog *prog)
952 {
953 	if (prog->type == BPF_PROG_TYPE_TRACING &&
954 	    prog->expected_attach_type == BPF_TRACE_ITER)
955 		return true;
956 
957 	if (prog->type == BPF_PROG_TYPE_LSM)
958 		return bpf_lsm_is_sleepable_hook(prog->aux->attach_btf_id);
959 
960 	return btf_id_set_contains(&btf_allowlist_d_path,
961 				   prog->aux->attach_btf_id);
962 }
963 
964 BTF_ID_LIST_SINGLE(bpf_d_path_btf_ids, struct, path)
965 
966 static const struct bpf_func_proto bpf_d_path_proto = {
967 	.func		= bpf_d_path,
968 	.gpl_only	= false,
969 	.ret_type	= RET_INTEGER,
970 	.arg1_type	= ARG_PTR_TO_BTF_ID,
971 	.arg1_btf_id	= &bpf_d_path_btf_ids[0],
972 	.arg2_type	= ARG_PTR_TO_MEM,
973 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
974 	.allowed	= bpf_d_path_allowed,
975 };
976 
977 #define BTF_F_ALL	(BTF_F_COMPACT  | BTF_F_NONAME | \
978 			 BTF_F_PTR_RAW | BTF_F_ZERO)
979 
bpf_btf_printf_prepare(struct btf_ptr * ptr,u32 btf_ptr_size,u64 flags,const struct btf ** btf,s32 * btf_id)980 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size,
981 				  u64 flags, const struct btf **btf,
982 				  s32 *btf_id)
983 {
984 	const struct btf_type *t;
985 
986 	if (unlikely(flags & ~(BTF_F_ALL)))
987 		return -EINVAL;
988 
989 	if (btf_ptr_size != sizeof(struct btf_ptr))
990 		return -EINVAL;
991 
992 	*btf = bpf_get_btf_vmlinux();
993 
994 	if (IS_ERR_OR_NULL(*btf))
995 		return IS_ERR(*btf) ? PTR_ERR(*btf) : -EINVAL;
996 
997 	if (ptr->type_id > 0)
998 		*btf_id = ptr->type_id;
999 	else
1000 		return -EINVAL;
1001 
1002 	if (*btf_id > 0)
1003 		t = btf_type_by_id(*btf, *btf_id);
1004 	if (*btf_id <= 0 || !t)
1005 		return -ENOENT;
1006 
1007 	return 0;
1008 }
1009 
BPF_CALL_5(bpf_snprintf_btf,char *,str,u32,str_size,struct btf_ptr *,ptr,u32,btf_ptr_size,u64,flags)1010 BPF_CALL_5(bpf_snprintf_btf, char *, str, u32, str_size, struct btf_ptr *, ptr,
1011 	   u32, btf_ptr_size, u64, flags)
1012 {
1013 	const struct btf *btf;
1014 	s32 btf_id;
1015 	int ret;
1016 
1017 	ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id);
1018 	if (ret)
1019 		return ret;
1020 
1021 	return btf_type_snprintf_show(btf, btf_id, ptr->ptr, str, str_size,
1022 				      flags);
1023 }
1024 
1025 const struct bpf_func_proto bpf_snprintf_btf_proto = {
1026 	.func		= bpf_snprintf_btf,
1027 	.gpl_only	= false,
1028 	.ret_type	= RET_INTEGER,
1029 	.arg1_type	= ARG_PTR_TO_MEM,
1030 	.arg2_type	= ARG_CONST_SIZE,
1031 	.arg3_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
1032 	.arg4_type	= ARG_CONST_SIZE,
1033 	.arg5_type	= ARG_ANYTHING,
1034 };
1035 
BPF_CALL_1(bpf_get_func_ip_tracing,void *,ctx)1036 BPF_CALL_1(bpf_get_func_ip_tracing, void *, ctx)
1037 {
1038 	/* This helper call is inlined by verifier. */
1039 	return ((u64 *)ctx)[-2];
1040 }
1041 
1042 static const struct bpf_func_proto bpf_get_func_ip_proto_tracing = {
1043 	.func		= bpf_get_func_ip_tracing,
1044 	.gpl_only	= true,
1045 	.ret_type	= RET_INTEGER,
1046 	.arg1_type	= ARG_PTR_TO_CTX,
1047 };
1048 
1049 #ifdef CONFIG_X86_KERNEL_IBT
get_entry_ip(unsigned long fentry_ip)1050 static unsigned long get_entry_ip(unsigned long fentry_ip)
1051 {
1052 	u32 instr;
1053 
1054 	/* Being extra safe in here in case entry ip is on the page-edge. */
1055 	if (get_kernel_nofault(instr, (u32 *) fentry_ip - 1))
1056 		return fentry_ip;
1057 	if (is_endbr(instr))
1058 		fentry_ip -= ENDBR_INSN_SIZE;
1059 	return fentry_ip;
1060 }
1061 #else
1062 #define get_entry_ip(fentry_ip) fentry_ip
1063 #endif
1064 
BPF_CALL_1(bpf_get_func_ip_kprobe,struct pt_regs *,regs)1065 BPF_CALL_1(bpf_get_func_ip_kprobe, struct pt_regs *, regs)
1066 {
1067 	struct bpf_trace_run_ctx *run_ctx __maybe_unused;
1068 	struct kprobe *kp;
1069 
1070 #ifdef CONFIG_UPROBES
1071 	run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx);
1072 	if (run_ctx->is_uprobe)
1073 		return ((struct uprobe_dispatch_data *)current->utask->vaddr)->bp_addr;
1074 #endif
1075 
1076 	kp = kprobe_running();
1077 
1078 	if (!kp || !(kp->flags & KPROBE_FLAG_ON_FUNC_ENTRY))
1079 		return 0;
1080 
1081 	return get_entry_ip((uintptr_t)kp->addr);
1082 }
1083 
1084 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe = {
1085 	.func		= bpf_get_func_ip_kprobe,
1086 	.gpl_only	= true,
1087 	.ret_type	= RET_INTEGER,
1088 	.arg1_type	= ARG_PTR_TO_CTX,
1089 };
1090 
BPF_CALL_1(bpf_get_func_ip_kprobe_multi,struct pt_regs *,regs)1091 BPF_CALL_1(bpf_get_func_ip_kprobe_multi, struct pt_regs *, regs)
1092 {
1093 	return bpf_kprobe_multi_entry_ip(current->bpf_ctx);
1094 }
1095 
1096 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe_multi = {
1097 	.func		= bpf_get_func_ip_kprobe_multi,
1098 	.gpl_only	= false,
1099 	.ret_type	= RET_INTEGER,
1100 	.arg1_type	= ARG_PTR_TO_CTX,
1101 };
1102 
BPF_CALL_1(bpf_get_attach_cookie_kprobe_multi,struct pt_regs *,regs)1103 BPF_CALL_1(bpf_get_attach_cookie_kprobe_multi, struct pt_regs *, regs)
1104 {
1105 	return bpf_kprobe_multi_cookie(current->bpf_ctx);
1106 }
1107 
1108 static const struct bpf_func_proto bpf_get_attach_cookie_proto_kmulti = {
1109 	.func		= bpf_get_attach_cookie_kprobe_multi,
1110 	.gpl_only	= false,
1111 	.ret_type	= RET_INTEGER,
1112 	.arg1_type	= ARG_PTR_TO_CTX,
1113 };
1114 
BPF_CALL_1(bpf_get_func_ip_uprobe_multi,struct pt_regs *,regs)1115 BPF_CALL_1(bpf_get_func_ip_uprobe_multi, struct pt_regs *, regs)
1116 {
1117 	return bpf_uprobe_multi_entry_ip(current->bpf_ctx);
1118 }
1119 
1120 static const struct bpf_func_proto bpf_get_func_ip_proto_uprobe_multi = {
1121 	.func		= bpf_get_func_ip_uprobe_multi,
1122 	.gpl_only	= false,
1123 	.ret_type	= RET_INTEGER,
1124 	.arg1_type	= ARG_PTR_TO_CTX,
1125 };
1126 
BPF_CALL_1(bpf_get_attach_cookie_uprobe_multi,struct pt_regs *,regs)1127 BPF_CALL_1(bpf_get_attach_cookie_uprobe_multi, struct pt_regs *, regs)
1128 {
1129 	return bpf_uprobe_multi_cookie(current->bpf_ctx);
1130 }
1131 
1132 static const struct bpf_func_proto bpf_get_attach_cookie_proto_umulti = {
1133 	.func		= bpf_get_attach_cookie_uprobe_multi,
1134 	.gpl_only	= false,
1135 	.ret_type	= RET_INTEGER,
1136 	.arg1_type	= ARG_PTR_TO_CTX,
1137 };
1138 
BPF_CALL_1(bpf_get_attach_cookie_trace,void *,ctx)1139 BPF_CALL_1(bpf_get_attach_cookie_trace, void *, ctx)
1140 {
1141 	struct bpf_trace_run_ctx *run_ctx;
1142 
1143 	run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx);
1144 	return run_ctx->bpf_cookie;
1145 }
1146 
1147 static const struct bpf_func_proto bpf_get_attach_cookie_proto_trace = {
1148 	.func		= bpf_get_attach_cookie_trace,
1149 	.gpl_only	= false,
1150 	.ret_type	= RET_INTEGER,
1151 	.arg1_type	= ARG_PTR_TO_CTX,
1152 };
1153 
BPF_CALL_1(bpf_get_attach_cookie_pe,struct bpf_perf_event_data_kern *,ctx)1154 BPF_CALL_1(bpf_get_attach_cookie_pe, struct bpf_perf_event_data_kern *, ctx)
1155 {
1156 	return ctx->event->bpf_cookie;
1157 }
1158 
1159 static const struct bpf_func_proto bpf_get_attach_cookie_proto_pe = {
1160 	.func		= bpf_get_attach_cookie_pe,
1161 	.gpl_only	= false,
1162 	.ret_type	= RET_INTEGER,
1163 	.arg1_type	= ARG_PTR_TO_CTX,
1164 };
1165 
BPF_CALL_1(bpf_get_attach_cookie_tracing,void *,ctx)1166 BPF_CALL_1(bpf_get_attach_cookie_tracing, void *, ctx)
1167 {
1168 	struct bpf_trace_run_ctx *run_ctx;
1169 
1170 	run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx);
1171 	return run_ctx->bpf_cookie;
1172 }
1173 
1174 static const struct bpf_func_proto bpf_get_attach_cookie_proto_tracing = {
1175 	.func		= bpf_get_attach_cookie_tracing,
1176 	.gpl_only	= false,
1177 	.ret_type	= RET_INTEGER,
1178 	.arg1_type	= ARG_PTR_TO_CTX,
1179 };
1180 
BPF_CALL_3(bpf_get_branch_snapshot,void *,buf,u32,size,u64,flags)1181 BPF_CALL_3(bpf_get_branch_snapshot, void *, buf, u32, size, u64, flags)
1182 {
1183 #ifndef CONFIG_X86
1184 	return -ENOENT;
1185 #else
1186 	static const u32 br_entry_size = sizeof(struct perf_branch_entry);
1187 	u32 entry_cnt = size / br_entry_size;
1188 
1189 	entry_cnt = static_call(perf_snapshot_branch_stack)(buf, entry_cnt);
1190 
1191 	if (unlikely(flags))
1192 		return -EINVAL;
1193 
1194 	if (!entry_cnt)
1195 		return -ENOENT;
1196 
1197 	return entry_cnt * br_entry_size;
1198 #endif
1199 }
1200 
1201 static const struct bpf_func_proto bpf_get_branch_snapshot_proto = {
1202 	.func		= bpf_get_branch_snapshot,
1203 	.gpl_only	= true,
1204 	.ret_type	= RET_INTEGER,
1205 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
1206 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
1207 };
1208 
BPF_CALL_3(get_func_arg,void *,ctx,u32,n,u64 *,value)1209 BPF_CALL_3(get_func_arg, void *, ctx, u32, n, u64 *, value)
1210 {
1211 	/* This helper call is inlined by verifier. */
1212 	u64 nr_args = ((u64 *)ctx)[-1];
1213 
1214 	if ((u64) n >= nr_args)
1215 		return -EINVAL;
1216 	*value = ((u64 *)ctx)[n];
1217 	return 0;
1218 }
1219 
1220 static const struct bpf_func_proto bpf_get_func_arg_proto = {
1221 	.func		= get_func_arg,
1222 	.ret_type	= RET_INTEGER,
1223 	.arg1_type	= ARG_PTR_TO_CTX,
1224 	.arg2_type	= ARG_ANYTHING,
1225 	.arg3_type	= ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED,
1226 	.arg3_size	= sizeof(u64),
1227 };
1228 
BPF_CALL_2(get_func_ret,void *,ctx,u64 *,value)1229 BPF_CALL_2(get_func_ret, void *, ctx, u64 *, value)
1230 {
1231 	/* This helper call is inlined by verifier. */
1232 	u64 nr_args = ((u64 *)ctx)[-1];
1233 
1234 	*value = ((u64 *)ctx)[nr_args];
1235 	return 0;
1236 }
1237 
1238 static const struct bpf_func_proto bpf_get_func_ret_proto = {
1239 	.func		= get_func_ret,
1240 	.ret_type	= RET_INTEGER,
1241 	.arg1_type	= ARG_PTR_TO_CTX,
1242 	.arg2_type	= ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED,
1243 	.arg2_size	= sizeof(u64),
1244 };
1245 
BPF_CALL_1(get_func_arg_cnt,void *,ctx)1246 BPF_CALL_1(get_func_arg_cnt, void *, ctx)
1247 {
1248 	/* This helper call is inlined by verifier. */
1249 	return ((u64 *)ctx)[-1];
1250 }
1251 
1252 static const struct bpf_func_proto bpf_get_func_arg_cnt_proto = {
1253 	.func		= get_func_arg_cnt,
1254 	.ret_type	= RET_INTEGER,
1255 	.arg1_type	= ARG_PTR_TO_CTX,
1256 };
1257 
1258 #ifdef CONFIG_KEYS
1259 __diag_push();
1260 __diag_ignore_all("-Wmissing-prototypes",
1261 		  "kfuncs which will be used in BPF programs");
1262 
1263 /**
1264  * bpf_lookup_user_key - lookup a key by its serial
1265  * @serial: key handle serial number
1266  * @flags: lookup-specific flags
1267  *
1268  * Search a key with a given *serial* and the provided *flags*.
1269  * If found, increment the reference count of the key by one, and
1270  * return it in the bpf_key structure.
1271  *
1272  * The bpf_key structure must be passed to bpf_key_put() when done
1273  * with it, so that the key reference count is decremented and the
1274  * bpf_key structure is freed.
1275  *
1276  * Permission checks are deferred to the time the key is used by
1277  * one of the available key-specific kfuncs.
1278  *
1279  * Set *flags* with KEY_LOOKUP_CREATE, to attempt creating a requested
1280  * special keyring (e.g. session keyring), if it doesn't yet exist.
1281  * Set *flags* with KEY_LOOKUP_PARTIAL, to lookup a key without waiting
1282  * for the key construction, and to retrieve uninstantiated keys (keys
1283  * without data attached to them).
1284  *
1285  * Return: a bpf_key pointer with a valid key pointer if the key is found, a
1286  *         NULL pointer otherwise.
1287  */
bpf_lookup_user_key(u32 serial,u64 flags)1288 __bpf_kfunc struct bpf_key *bpf_lookup_user_key(u32 serial, u64 flags)
1289 {
1290 	key_ref_t key_ref;
1291 	struct bpf_key *bkey;
1292 
1293 	if (flags & ~KEY_LOOKUP_ALL)
1294 		return NULL;
1295 
1296 	/*
1297 	 * Permission check is deferred until the key is used, as the
1298 	 * intent of the caller is unknown here.
1299 	 */
1300 	key_ref = lookup_user_key(serial, flags, KEY_DEFER_PERM_CHECK);
1301 	if (IS_ERR(key_ref))
1302 		return NULL;
1303 
1304 	bkey = kmalloc(sizeof(*bkey), GFP_KERNEL);
1305 	if (!bkey) {
1306 		key_put(key_ref_to_ptr(key_ref));
1307 		return NULL;
1308 	}
1309 
1310 	bkey->key = key_ref_to_ptr(key_ref);
1311 	bkey->has_ref = true;
1312 
1313 	return bkey;
1314 }
1315 
1316 /**
1317  * bpf_lookup_system_key - lookup a key by a system-defined ID
1318  * @id: key ID
1319  *
1320  * Obtain a bpf_key structure with a key pointer set to the passed key ID.
1321  * The key pointer is marked as invalid, to prevent bpf_key_put() from
1322  * attempting to decrement the key reference count on that pointer. The key
1323  * pointer set in such way is currently understood only by
1324  * verify_pkcs7_signature().
1325  *
1326  * Set *id* to one of the values defined in include/linux/verification.h:
1327  * 0 for the primary keyring (immutable keyring of system keys);
1328  * VERIFY_USE_SECONDARY_KEYRING for both the primary and secondary keyring
1329  * (where keys can be added only if they are vouched for by existing keys
1330  * in those keyrings); VERIFY_USE_PLATFORM_KEYRING for the platform
1331  * keyring (primarily used by the integrity subsystem to verify a kexec'ed
1332  * kerned image and, possibly, the initramfs signature).
1333  *
1334  * Return: a bpf_key pointer with an invalid key pointer set from the
1335  *         pre-determined ID on success, a NULL pointer otherwise
1336  */
bpf_lookup_system_key(u64 id)1337 __bpf_kfunc struct bpf_key *bpf_lookup_system_key(u64 id)
1338 {
1339 	struct bpf_key *bkey;
1340 
1341 	if (system_keyring_id_check(id) < 0)
1342 		return NULL;
1343 
1344 	bkey = kmalloc(sizeof(*bkey), GFP_ATOMIC);
1345 	if (!bkey)
1346 		return NULL;
1347 
1348 	bkey->key = (struct key *)(unsigned long)id;
1349 	bkey->has_ref = false;
1350 
1351 	return bkey;
1352 }
1353 
1354 /**
1355  * bpf_key_put - decrement key reference count if key is valid and free bpf_key
1356  * @bkey: bpf_key structure
1357  *
1358  * Decrement the reference count of the key inside *bkey*, if the pointer
1359  * is valid, and free *bkey*.
1360  */
bpf_key_put(struct bpf_key * bkey)1361 __bpf_kfunc void bpf_key_put(struct bpf_key *bkey)
1362 {
1363 	if (bkey->has_ref)
1364 		key_put(bkey->key);
1365 
1366 	kfree(bkey);
1367 }
1368 
1369 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION
1370 /**
1371  * bpf_verify_pkcs7_signature - verify a PKCS#7 signature
1372  * @data_ptr: data to verify
1373  * @sig_ptr: signature of the data
1374  * @trusted_keyring: keyring with keys trusted for signature verification
1375  *
1376  * Verify the PKCS#7 signature *sig_ptr* against the supplied *data_ptr*
1377  * with keys in a keyring referenced by *trusted_keyring*.
1378  *
1379  * Return: 0 on success, a negative value on error.
1380  */
bpf_verify_pkcs7_signature(struct bpf_dynptr_kern * data_ptr,struct bpf_dynptr_kern * sig_ptr,struct bpf_key * trusted_keyring)1381 __bpf_kfunc int bpf_verify_pkcs7_signature(struct bpf_dynptr_kern *data_ptr,
1382 			       struct bpf_dynptr_kern *sig_ptr,
1383 			       struct bpf_key *trusted_keyring)
1384 {
1385 	int ret;
1386 
1387 	if (trusted_keyring->has_ref) {
1388 		/*
1389 		 * Do the permission check deferred in bpf_lookup_user_key().
1390 		 * See bpf_lookup_user_key() for more details.
1391 		 *
1392 		 * A call to key_task_permission() here would be redundant, as
1393 		 * it is already done by keyring_search() called by
1394 		 * find_asymmetric_key().
1395 		 */
1396 		ret = key_validate(trusted_keyring->key);
1397 		if (ret < 0)
1398 			return ret;
1399 	}
1400 
1401 	return verify_pkcs7_signature(data_ptr->data,
1402 				      __bpf_dynptr_size(data_ptr),
1403 				      sig_ptr->data,
1404 				      __bpf_dynptr_size(sig_ptr),
1405 				      trusted_keyring->key,
1406 				      VERIFYING_UNSPECIFIED_SIGNATURE, NULL,
1407 				      NULL);
1408 }
1409 #endif /* CONFIG_SYSTEM_DATA_VERIFICATION */
1410 
1411 __diag_pop();
1412 
1413 BTF_SET8_START(key_sig_kfunc_set)
1414 BTF_ID_FLAGS(func, bpf_lookup_user_key, KF_ACQUIRE | KF_RET_NULL | KF_SLEEPABLE)
1415 BTF_ID_FLAGS(func, bpf_lookup_system_key, KF_ACQUIRE | KF_RET_NULL)
1416 BTF_ID_FLAGS(func, bpf_key_put, KF_RELEASE)
1417 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION
1418 BTF_ID_FLAGS(func, bpf_verify_pkcs7_signature, KF_SLEEPABLE)
1419 #endif
1420 BTF_SET8_END(key_sig_kfunc_set)
1421 
1422 static const struct btf_kfunc_id_set bpf_key_sig_kfunc_set = {
1423 	.owner = THIS_MODULE,
1424 	.set = &key_sig_kfunc_set,
1425 };
1426 
bpf_key_sig_kfuncs_init(void)1427 static int __init bpf_key_sig_kfuncs_init(void)
1428 {
1429 	return register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING,
1430 					 &bpf_key_sig_kfunc_set);
1431 }
1432 
1433 late_initcall(bpf_key_sig_kfuncs_init);
1434 #endif /* CONFIG_KEYS */
1435 
1436 static const struct bpf_func_proto *
bpf_tracing_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1437 bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1438 {
1439 	switch (func_id) {
1440 	case BPF_FUNC_map_lookup_elem:
1441 		return &bpf_map_lookup_elem_proto;
1442 	case BPF_FUNC_map_update_elem:
1443 		return &bpf_map_update_elem_proto;
1444 	case BPF_FUNC_map_delete_elem:
1445 		return &bpf_map_delete_elem_proto;
1446 	case BPF_FUNC_map_push_elem:
1447 		return &bpf_map_push_elem_proto;
1448 	case BPF_FUNC_map_pop_elem:
1449 		return &bpf_map_pop_elem_proto;
1450 	case BPF_FUNC_map_peek_elem:
1451 		return &bpf_map_peek_elem_proto;
1452 	case BPF_FUNC_map_lookup_percpu_elem:
1453 		return &bpf_map_lookup_percpu_elem_proto;
1454 	case BPF_FUNC_ktime_get_ns:
1455 		return &bpf_ktime_get_ns_proto;
1456 	case BPF_FUNC_ktime_get_boot_ns:
1457 		return &bpf_ktime_get_boot_ns_proto;
1458 	case BPF_FUNC_tail_call:
1459 		return &bpf_tail_call_proto;
1460 	case BPF_FUNC_get_current_pid_tgid:
1461 		return &bpf_get_current_pid_tgid_proto;
1462 	case BPF_FUNC_get_current_task:
1463 		return &bpf_get_current_task_proto;
1464 	case BPF_FUNC_get_current_task_btf:
1465 		return &bpf_get_current_task_btf_proto;
1466 	case BPF_FUNC_task_pt_regs:
1467 		return &bpf_task_pt_regs_proto;
1468 	case BPF_FUNC_get_current_uid_gid:
1469 		return &bpf_get_current_uid_gid_proto;
1470 	case BPF_FUNC_get_current_comm:
1471 		return &bpf_get_current_comm_proto;
1472 	case BPF_FUNC_trace_printk:
1473 		return bpf_get_trace_printk_proto();
1474 	case BPF_FUNC_get_smp_processor_id:
1475 		return &bpf_get_smp_processor_id_proto;
1476 	case BPF_FUNC_get_numa_node_id:
1477 		return &bpf_get_numa_node_id_proto;
1478 	case BPF_FUNC_perf_event_read:
1479 		return &bpf_perf_event_read_proto;
1480 	case BPF_FUNC_current_task_under_cgroup:
1481 		return &bpf_current_task_under_cgroup_proto;
1482 	case BPF_FUNC_get_prandom_u32:
1483 		return &bpf_get_prandom_u32_proto;
1484 	case BPF_FUNC_probe_write_user:
1485 		return security_locked_down(LOCKDOWN_BPF_WRITE_USER) < 0 ?
1486 		       NULL : bpf_get_probe_write_proto();
1487 	case BPF_FUNC_probe_read_user:
1488 		return &bpf_probe_read_user_proto;
1489 	case BPF_FUNC_probe_read_kernel:
1490 		return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
1491 		       NULL : &bpf_probe_read_kernel_proto;
1492 	case BPF_FUNC_probe_read_user_str:
1493 		return &bpf_probe_read_user_str_proto;
1494 	case BPF_FUNC_probe_read_kernel_str:
1495 		return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
1496 		       NULL : &bpf_probe_read_kernel_str_proto;
1497 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
1498 	case BPF_FUNC_probe_read:
1499 		return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
1500 		       NULL : &bpf_probe_read_compat_proto;
1501 	case BPF_FUNC_probe_read_str:
1502 		return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
1503 		       NULL : &bpf_probe_read_compat_str_proto;
1504 #endif
1505 #ifdef CONFIG_CGROUPS
1506 	case BPF_FUNC_cgrp_storage_get:
1507 		return &bpf_cgrp_storage_get_proto;
1508 	case BPF_FUNC_cgrp_storage_delete:
1509 		return &bpf_cgrp_storage_delete_proto;
1510 #endif
1511 	case BPF_FUNC_send_signal:
1512 		return &bpf_send_signal_proto;
1513 	case BPF_FUNC_send_signal_thread:
1514 		return &bpf_send_signal_thread_proto;
1515 	case BPF_FUNC_perf_event_read_value:
1516 		return &bpf_perf_event_read_value_proto;
1517 	case BPF_FUNC_get_ns_current_pid_tgid:
1518 		return &bpf_get_ns_current_pid_tgid_proto;
1519 	case BPF_FUNC_ringbuf_output:
1520 		return &bpf_ringbuf_output_proto;
1521 	case BPF_FUNC_ringbuf_reserve:
1522 		return &bpf_ringbuf_reserve_proto;
1523 	case BPF_FUNC_ringbuf_submit:
1524 		return &bpf_ringbuf_submit_proto;
1525 	case BPF_FUNC_ringbuf_discard:
1526 		return &bpf_ringbuf_discard_proto;
1527 	case BPF_FUNC_ringbuf_query:
1528 		return &bpf_ringbuf_query_proto;
1529 	case BPF_FUNC_jiffies64:
1530 		return &bpf_jiffies64_proto;
1531 	case BPF_FUNC_get_task_stack:
1532 		return &bpf_get_task_stack_proto;
1533 	case BPF_FUNC_copy_from_user:
1534 		return &bpf_copy_from_user_proto;
1535 	case BPF_FUNC_copy_from_user_task:
1536 		return &bpf_copy_from_user_task_proto;
1537 	case BPF_FUNC_snprintf_btf:
1538 		return &bpf_snprintf_btf_proto;
1539 	case BPF_FUNC_per_cpu_ptr:
1540 		return &bpf_per_cpu_ptr_proto;
1541 	case BPF_FUNC_this_cpu_ptr:
1542 		return &bpf_this_cpu_ptr_proto;
1543 	case BPF_FUNC_task_storage_get:
1544 		if (bpf_prog_check_recur(prog))
1545 			return &bpf_task_storage_get_recur_proto;
1546 		return &bpf_task_storage_get_proto;
1547 	case BPF_FUNC_task_storage_delete:
1548 		if (bpf_prog_check_recur(prog))
1549 			return &bpf_task_storage_delete_recur_proto;
1550 		return &bpf_task_storage_delete_proto;
1551 	case BPF_FUNC_for_each_map_elem:
1552 		return &bpf_for_each_map_elem_proto;
1553 	case BPF_FUNC_snprintf:
1554 		return &bpf_snprintf_proto;
1555 	case BPF_FUNC_get_func_ip:
1556 		return &bpf_get_func_ip_proto_tracing;
1557 	case BPF_FUNC_get_branch_snapshot:
1558 		return &bpf_get_branch_snapshot_proto;
1559 	case BPF_FUNC_find_vma:
1560 		return &bpf_find_vma_proto;
1561 	case BPF_FUNC_trace_vprintk:
1562 		return bpf_get_trace_vprintk_proto();
1563 	default:
1564 		return bpf_base_func_proto(func_id);
1565 	}
1566 }
1567 
1568 static const struct bpf_func_proto *
kprobe_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1569 kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1570 {
1571 	switch (func_id) {
1572 	case BPF_FUNC_perf_event_output:
1573 		return &bpf_perf_event_output_proto;
1574 	case BPF_FUNC_get_stackid:
1575 		return &bpf_get_stackid_proto;
1576 	case BPF_FUNC_get_stack:
1577 		return &bpf_get_stack_proto;
1578 #ifdef CONFIG_BPF_KPROBE_OVERRIDE
1579 	case BPF_FUNC_override_return:
1580 		return &bpf_override_return_proto;
1581 #endif
1582 	case BPF_FUNC_get_func_ip:
1583 		if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI)
1584 			return &bpf_get_func_ip_proto_kprobe_multi;
1585 		if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI)
1586 			return &bpf_get_func_ip_proto_uprobe_multi;
1587 		return &bpf_get_func_ip_proto_kprobe;
1588 	case BPF_FUNC_get_attach_cookie:
1589 		if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI)
1590 			return &bpf_get_attach_cookie_proto_kmulti;
1591 		if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI)
1592 			return &bpf_get_attach_cookie_proto_umulti;
1593 		return &bpf_get_attach_cookie_proto_trace;
1594 	default:
1595 		return bpf_tracing_func_proto(func_id, prog);
1596 	}
1597 }
1598 
1599 /* 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)1600 static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
1601 					const struct bpf_prog *prog,
1602 					struct bpf_insn_access_aux *info)
1603 {
1604 	if (off < 0 || off >= sizeof(struct pt_regs))
1605 		return false;
1606 	if (type != BPF_READ)
1607 		return false;
1608 	if (off % size != 0)
1609 		return false;
1610 	/*
1611 	 * Assertion for 32 bit to make sure last 8 byte access
1612 	 * (BPF_DW) to the last 4 byte member is disallowed.
1613 	 */
1614 	if (off + size > sizeof(struct pt_regs))
1615 		return false;
1616 
1617 	return true;
1618 }
1619 
1620 const struct bpf_verifier_ops kprobe_verifier_ops = {
1621 	.get_func_proto  = kprobe_prog_func_proto,
1622 	.is_valid_access = kprobe_prog_is_valid_access,
1623 };
1624 
1625 const struct bpf_prog_ops kprobe_prog_ops = {
1626 };
1627 
BPF_CALL_5(bpf_perf_event_output_tp,void *,tp_buff,struct bpf_map *,map,u64,flags,void *,data,u64,size)1628 BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map,
1629 	   u64, flags, void *, data, u64, size)
1630 {
1631 	struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1632 
1633 	/*
1634 	 * r1 points to perf tracepoint buffer where first 8 bytes are hidden
1635 	 * from bpf program and contain a pointer to 'struct pt_regs'. Fetch it
1636 	 * from there and call the same bpf_perf_event_output() helper inline.
1637 	 */
1638 	return ____bpf_perf_event_output(regs, map, flags, data, size);
1639 }
1640 
1641 static const struct bpf_func_proto bpf_perf_event_output_proto_tp = {
1642 	.func		= bpf_perf_event_output_tp,
1643 	.gpl_only	= true,
1644 	.ret_type	= RET_INTEGER,
1645 	.arg1_type	= ARG_PTR_TO_CTX,
1646 	.arg2_type	= ARG_CONST_MAP_PTR,
1647 	.arg3_type	= ARG_ANYTHING,
1648 	.arg4_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
1649 	.arg5_type	= ARG_CONST_SIZE_OR_ZERO,
1650 };
1651 
BPF_CALL_3(bpf_get_stackid_tp,void *,tp_buff,struct bpf_map *,map,u64,flags)1652 BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map,
1653 	   u64, flags)
1654 {
1655 	struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1656 
1657 	/*
1658 	 * Same comment as in bpf_perf_event_output_tp(), only that this time
1659 	 * the other helper's function body cannot be inlined due to being
1660 	 * external, thus we need to call raw helper function.
1661 	 */
1662 	return bpf_get_stackid((unsigned long) regs, (unsigned long) map,
1663 			       flags, 0, 0);
1664 }
1665 
1666 static const struct bpf_func_proto bpf_get_stackid_proto_tp = {
1667 	.func		= bpf_get_stackid_tp,
1668 	.gpl_only	= true,
1669 	.ret_type	= RET_INTEGER,
1670 	.arg1_type	= ARG_PTR_TO_CTX,
1671 	.arg2_type	= ARG_CONST_MAP_PTR,
1672 	.arg3_type	= ARG_ANYTHING,
1673 };
1674 
BPF_CALL_4(bpf_get_stack_tp,void *,tp_buff,void *,buf,u32,size,u64,flags)1675 BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size,
1676 	   u64, flags)
1677 {
1678 	struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1679 
1680 	return bpf_get_stack((unsigned long) regs, (unsigned long) buf,
1681 			     (unsigned long) size, flags, 0);
1682 }
1683 
1684 static const struct bpf_func_proto bpf_get_stack_proto_tp = {
1685 	.func		= bpf_get_stack_tp,
1686 	.gpl_only	= true,
1687 	.ret_type	= RET_INTEGER,
1688 	.arg1_type	= ARG_PTR_TO_CTX,
1689 	.arg2_type	= ARG_PTR_TO_UNINIT_MEM,
1690 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
1691 	.arg4_type	= ARG_ANYTHING,
1692 };
1693 
1694 static const struct bpf_func_proto *
tp_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1695 tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1696 {
1697 	switch (func_id) {
1698 	case BPF_FUNC_perf_event_output:
1699 		return &bpf_perf_event_output_proto_tp;
1700 	case BPF_FUNC_get_stackid:
1701 		return &bpf_get_stackid_proto_tp;
1702 	case BPF_FUNC_get_stack:
1703 		return &bpf_get_stack_proto_tp;
1704 	case BPF_FUNC_get_attach_cookie:
1705 		return &bpf_get_attach_cookie_proto_trace;
1706 	default:
1707 		return bpf_tracing_func_proto(func_id, prog);
1708 	}
1709 }
1710 
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)1711 static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type,
1712 				    const struct bpf_prog *prog,
1713 				    struct bpf_insn_access_aux *info)
1714 {
1715 	if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE)
1716 		return false;
1717 	if (type != BPF_READ)
1718 		return false;
1719 	if (off % size != 0)
1720 		return false;
1721 
1722 	BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(__u64));
1723 	return true;
1724 }
1725 
1726 const struct bpf_verifier_ops tracepoint_verifier_ops = {
1727 	.get_func_proto  = tp_prog_func_proto,
1728 	.is_valid_access = tp_prog_is_valid_access,
1729 };
1730 
1731 const struct bpf_prog_ops tracepoint_prog_ops = {
1732 };
1733 
BPF_CALL_3(bpf_perf_prog_read_value,struct bpf_perf_event_data_kern *,ctx,struct bpf_perf_event_value *,buf,u32,size)1734 BPF_CALL_3(bpf_perf_prog_read_value, struct bpf_perf_event_data_kern *, ctx,
1735 	   struct bpf_perf_event_value *, buf, u32, size)
1736 {
1737 	int err = -EINVAL;
1738 
1739 	if (unlikely(size != sizeof(struct bpf_perf_event_value)))
1740 		goto clear;
1741 	err = perf_event_read_local(ctx->event, &buf->counter, &buf->enabled,
1742 				    &buf->running);
1743 	if (unlikely(err))
1744 		goto clear;
1745 	return 0;
1746 clear:
1747 	memset(buf, 0, size);
1748 	return err;
1749 }
1750 
1751 static const struct bpf_func_proto bpf_perf_prog_read_value_proto = {
1752          .func           = bpf_perf_prog_read_value,
1753          .gpl_only       = true,
1754          .ret_type       = RET_INTEGER,
1755          .arg1_type      = ARG_PTR_TO_CTX,
1756          .arg2_type      = ARG_PTR_TO_UNINIT_MEM,
1757          .arg3_type      = ARG_CONST_SIZE,
1758 };
1759 
BPF_CALL_4(bpf_read_branch_records,struct bpf_perf_event_data_kern *,ctx,void *,buf,u32,size,u64,flags)1760 BPF_CALL_4(bpf_read_branch_records, struct bpf_perf_event_data_kern *, ctx,
1761 	   void *, buf, u32, size, u64, flags)
1762 {
1763 	static const u32 br_entry_size = sizeof(struct perf_branch_entry);
1764 	struct perf_branch_stack *br_stack = ctx->data->br_stack;
1765 	u32 to_copy;
1766 
1767 	if (unlikely(flags & ~BPF_F_GET_BRANCH_RECORDS_SIZE))
1768 		return -EINVAL;
1769 
1770 	if (unlikely(!(ctx->data->sample_flags & PERF_SAMPLE_BRANCH_STACK)))
1771 		return -ENOENT;
1772 
1773 	if (unlikely(!br_stack))
1774 		return -ENOENT;
1775 
1776 	if (flags & BPF_F_GET_BRANCH_RECORDS_SIZE)
1777 		return br_stack->nr * br_entry_size;
1778 
1779 	if (!buf || (size % br_entry_size != 0))
1780 		return -EINVAL;
1781 
1782 	to_copy = min_t(u32, br_stack->nr * br_entry_size, size);
1783 	memcpy(buf, br_stack->entries, to_copy);
1784 
1785 	return to_copy;
1786 }
1787 
1788 static const struct bpf_func_proto bpf_read_branch_records_proto = {
1789 	.func           = bpf_read_branch_records,
1790 	.gpl_only       = true,
1791 	.ret_type       = RET_INTEGER,
1792 	.arg1_type      = ARG_PTR_TO_CTX,
1793 	.arg2_type      = ARG_PTR_TO_MEM_OR_NULL,
1794 	.arg3_type      = ARG_CONST_SIZE_OR_ZERO,
1795 	.arg4_type      = ARG_ANYTHING,
1796 };
1797 
1798 static const struct bpf_func_proto *
pe_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1799 pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1800 {
1801 	switch (func_id) {
1802 	case BPF_FUNC_perf_event_output:
1803 		return &bpf_perf_event_output_proto_tp;
1804 	case BPF_FUNC_get_stackid:
1805 		return &bpf_get_stackid_proto_pe;
1806 	case BPF_FUNC_get_stack:
1807 		return &bpf_get_stack_proto_pe;
1808 	case BPF_FUNC_perf_prog_read_value:
1809 		return &bpf_perf_prog_read_value_proto;
1810 	case BPF_FUNC_read_branch_records:
1811 		return &bpf_read_branch_records_proto;
1812 	case BPF_FUNC_get_attach_cookie:
1813 		return &bpf_get_attach_cookie_proto_pe;
1814 	default:
1815 		return bpf_tracing_func_proto(func_id, prog);
1816 	}
1817 }
1818 
1819 /*
1820  * bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp
1821  * to avoid potential recursive reuse issue when/if tracepoints are added
1822  * inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack.
1823  *
1824  * Since raw tracepoints run despite bpf_prog_active, support concurrent usage
1825  * in normal, irq, and nmi context.
1826  */
1827 struct bpf_raw_tp_regs {
1828 	struct pt_regs regs[3];
1829 };
1830 static DEFINE_PER_CPU(struct bpf_raw_tp_regs, bpf_raw_tp_regs);
1831 static DEFINE_PER_CPU(int, bpf_raw_tp_nest_level);
get_bpf_raw_tp_regs(void)1832 static struct pt_regs *get_bpf_raw_tp_regs(void)
1833 {
1834 	struct bpf_raw_tp_regs *tp_regs = this_cpu_ptr(&bpf_raw_tp_regs);
1835 	int nest_level = this_cpu_inc_return(bpf_raw_tp_nest_level);
1836 
1837 	if (nest_level > ARRAY_SIZE(tp_regs->regs)) {
1838 		this_cpu_dec(bpf_raw_tp_nest_level);
1839 		return ERR_PTR(-EBUSY);
1840 	}
1841 
1842 	return &tp_regs->regs[nest_level - 1];
1843 }
1844 
put_bpf_raw_tp_regs(void)1845 static void put_bpf_raw_tp_regs(void)
1846 {
1847 	this_cpu_dec(bpf_raw_tp_nest_level);
1848 }
1849 
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)1850 BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args,
1851 	   struct bpf_map *, map, u64, flags, void *, data, u64, size)
1852 {
1853 	struct pt_regs *regs = get_bpf_raw_tp_regs();
1854 	int ret;
1855 
1856 	if (IS_ERR(regs))
1857 		return PTR_ERR(regs);
1858 
1859 	perf_fetch_caller_regs(regs);
1860 	ret = ____bpf_perf_event_output(regs, map, flags, data, size);
1861 
1862 	put_bpf_raw_tp_regs();
1863 	return ret;
1864 }
1865 
1866 static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = {
1867 	.func		= bpf_perf_event_output_raw_tp,
1868 	.gpl_only	= true,
1869 	.ret_type	= RET_INTEGER,
1870 	.arg1_type	= ARG_PTR_TO_CTX,
1871 	.arg2_type	= ARG_CONST_MAP_PTR,
1872 	.arg3_type	= ARG_ANYTHING,
1873 	.arg4_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
1874 	.arg5_type	= ARG_CONST_SIZE_OR_ZERO,
1875 };
1876 
1877 extern const struct bpf_func_proto bpf_skb_output_proto;
1878 extern const struct bpf_func_proto bpf_xdp_output_proto;
1879 extern const struct bpf_func_proto bpf_xdp_get_buff_len_trace_proto;
1880 
BPF_CALL_3(bpf_get_stackid_raw_tp,struct bpf_raw_tracepoint_args *,args,struct bpf_map *,map,u64,flags)1881 BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args,
1882 	   struct bpf_map *, map, u64, flags)
1883 {
1884 	struct pt_regs *regs = get_bpf_raw_tp_regs();
1885 	int ret;
1886 
1887 	if (IS_ERR(regs))
1888 		return PTR_ERR(regs);
1889 
1890 	perf_fetch_caller_regs(regs);
1891 	/* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */
1892 	ret = bpf_get_stackid((unsigned long) regs, (unsigned long) map,
1893 			      flags, 0, 0);
1894 	put_bpf_raw_tp_regs();
1895 	return ret;
1896 }
1897 
1898 static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = {
1899 	.func		= bpf_get_stackid_raw_tp,
1900 	.gpl_only	= true,
1901 	.ret_type	= RET_INTEGER,
1902 	.arg1_type	= ARG_PTR_TO_CTX,
1903 	.arg2_type	= ARG_CONST_MAP_PTR,
1904 	.arg3_type	= ARG_ANYTHING,
1905 };
1906 
BPF_CALL_4(bpf_get_stack_raw_tp,struct bpf_raw_tracepoint_args *,args,void *,buf,u32,size,u64,flags)1907 BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args,
1908 	   void *, buf, u32, size, u64, flags)
1909 {
1910 	struct pt_regs *regs = get_bpf_raw_tp_regs();
1911 	int ret;
1912 
1913 	if (IS_ERR(regs))
1914 		return PTR_ERR(regs);
1915 
1916 	perf_fetch_caller_regs(regs);
1917 	ret = bpf_get_stack((unsigned long) regs, (unsigned long) buf,
1918 			    (unsigned long) size, flags, 0);
1919 	put_bpf_raw_tp_regs();
1920 	return ret;
1921 }
1922 
1923 static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = {
1924 	.func		= bpf_get_stack_raw_tp,
1925 	.gpl_only	= true,
1926 	.ret_type	= RET_INTEGER,
1927 	.arg1_type	= ARG_PTR_TO_CTX,
1928 	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
1929 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
1930 	.arg4_type	= ARG_ANYTHING,
1931 };
1932 
1933 static const struct bpf_func_proto *
raw_tp_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1934 raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1935 {
1936 	switch (func_id) {
1937 	case BPF_FUNC_perf_event_output:
1938 		return &bpf_perf_event_output_proto_raw_tp;
1939 	case BPF_FUNC_get_stackid:
1940 		return &bpf_get_stackid_proto_raw_tp;
1941 	case BPF_FUNC_get_stack:
1942 		return &bpf_get_stack_proto_raw_tp;
1943 	default:
1944 		return bpf_tracing_func_proto(func_id, prog);
1945 	}
1946 }
1947 
1948 const struct bpf_func_proto *
tracing_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1949 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1950 {
1951 	const struct bpf_func_proto *fn;
1952 
1953 	switch (func_id) {
1954 #ifdef CONFIG_NET
1955 	case BPF_FUNC_skb_output:
1956 		return &bpf_skb_output_proto;
1957 	case BPF_FUNC_xdp_output:
1958 		return &bpf_xdp_output_proto;
1959 	case BPF_FUNC_skc_to_tcp6_sock:
1960 		return &bpf_skc_to_tcp6_sock_proto;
1961 	case BPF_FUNC_skc_to_tcp_sock:
1962 		return &bpf_skc_to_tcp_sock_proto;
1963 	case BPF_FUNC_skc_to_tcp_timewait_sock:
1964 		return &bpf_skc_to_tcp_timewait_sock_proto;
1965 	case BPF_FUNC_skc_to_tcp_request_sock:
1966 		return &bpf_skc_to_tcp_request_sock_proto;
1967 	case BPF_FUNC_skc_to_udp6_sock:
1968 		return &bpf_skc_to_udp6_sock_proto;
1969 	case BPF_FUNC_skc_to_unix_sock:
1970 		return &bpf_skc_to_unix_sock_proto;
1971 	case BPF_FUNC_skc_to_mptcp_sock:
1972 		return &bpf_skc_to_mptcp_sock_proto;
1973 	case BPF_FUNC_sk_storage_get:
1974 		return &bpf_sk_storage_get_tracing_proto;
1975 	case BPF_FUNC_sk_storage_delete:
1976 		return &bpf_sk_storage_delete_tracing_proto;
1977 	case BPF_FUNC_sock_from_file:
1978 		return &bpf_sock_from_file_proto;
1979 	case BPF_FUNC_get_socket_cookie:
1980 		return &bpf_get_socket_ptr_cookie_proto;
1981 	case BPF_FUNC_xdp_get_buff_len:
1982 		return &bpf_xdp_get_buff_len_trace_proto;
1983 #endif
1984 	case BPF_FUNC_seq_printf:
1985 		return prog->expected_attach_type == BPF_TRACE_ITER ?
1986 		       &bpf_seq_printf_proto :
1987 		       NULL;
1988 	case BPF_FUNC_seq_write:
1989 		return prog->expected_attach_type == BPF_TRACE_ITER ?
1990 		       &bpf_seq_write_proto :
1991 		       NULL;
1992 	case BPF_FUNC_seq_printf_btf:
1993 		return prog->expected_attach_type == BPF_TRACE_ITER ?
1994 		       &bpf_seq_printf_btf_proto :
1995 		       NULL;
1996 	case BPF_FUNC_d_path:
1997 		return &bpf_d_path_proto;
1998 	case BPF_FUNC_get_func_arg:
1999 		return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_proto : NULL;
2000 	case BPF_FUNC_get_func_ret:
2001 		return bpf_prog_has_trampoline(prog) ? &bpf_get_func_ret_proto : NULL;
2002 	case BPF_FUNC_get_func_arg_cnt:
2003 		return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_cnt_proto : NULL;
2004 	case BPF_FUNC_get_attach_cookie:
2005 		return bpf_prog_has_trampoline(prog) ? &bpf_get_attach_cookie_proto_tracing : NULL;
2006 	default:
2007 		fn = raw_tp_prog_func_proto(func_id, prog);
2008 		if (!fn && prog->expected_attach_type == BPF_TRACE_ITER)
2009 			fn = bpf_iter_get_func_proto(func_id, prog);
2010 		return fn;
2011 	}
2012 }
2013 
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)2014 static bool raw_tp_prog_is_valid_access(int off, int size,
2015 					enum bpf_access_type type,
2016 					const struct bpf_prog *prog,
2017 					struct bpf_insn_access_aux *info)
2018 {
2019 	return bpf_tracing_ctx_access(off, size, type);
2020 }
2021 
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)2022 static bool tracing_prog_is_valid_access(int off, int size,
2023 					 enum bpf_access_type type,
2024 					 const struct bpf_prog *prog,
2025 					 struct bpf_insn_access_aux *info)
2026 {
2027 	return bpf_tracing_btf_ctx_access(off, size, type, prog, info);
2028 }
2029 
bpf_prog_test_run_tracing(struct bpf_prog * prog,const union bpf_attr * kattr,union bpf_attr __user * uattr)2030 int __weak bpf_prog_test_run_tracing(struct bpf_prog *prog,
2031 				     const union bpf_attr *kattr,
2032 				     union bpf_attr __user *uattr)
2033 {
2034 	return -ENOTSUPP;
2035 }
2036 
2037 const struct bpf_verifier_ops raw_tracepoint_verifier_ops = {
2038 	.get_func_proto  = raw_tp_prog_func_proto,
2039 	.is_valid_access = raw_tp_prog_is_valid_access,
2040 };
2041 
2042 const struct bpf_prog_ops raw_tracepoint_prog_ops = {
2043 #ifdef CONFIG_NET
2044 	.test_run = bpf_prog_test_run_raw_tp,
2045 #endif
2046 };
2047 
2048 const struct bpf_verifier_ops tracing_verifier_ops = {
2049 	.get_func_proto  = tracing_prog_func_proto,
2050 	.is_valid_access = tracing_prog_is_valid_access,
2051 };
2052 
2053 const struct bpf_prog_ops tracing_prog_ops = {
2054 	.test_run = bpf_prog_test_run_tracing,
2055 };
2056 
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)2057 static bool raw_tp_writable_prog_is_valid_access(int off, int size,
2058 						 enum bpf_access_type type,
2059 						 const struct bpf_prog *prog,
2060 						 struct bpf_insn_access_aux *info)
2061 {
2062 	if (off == 0) {
2063 		if (size != sizeof(u64) || type != BPF_READ)
2064 			return false;
2065 		info->reg_type = PTR_TO_TP_BUFFER;
2066 	}
2067 	return raw_tp_prog_is_valid_access(off, size, type, prog, info);
2068 }
2069 
2070 const struct bpf_verifier_ops raw_tracepoint_writable_verifier_ops = {
2071 	.get_func_proto  = raw_tp_prog_func_proto,
2072 	.is_valid_access = raw_tp_writable_prog_is_valid_access,
2073 };
2074 
2075 const struct bpf_prog_ops raw_tracepoint_writable_prog_ops = {
2076 };
2077 
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)2078 static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
2079 				    const struct bpf_prog *prog,
2080 				    struct bpf_insn_access_aux *info)
2081 {
2082 	const int size_u64 = sizeof(u64);
2083 
2084 	if (off < 0 || off >= sizeof(struct bpf_perf_event_data))
2085 		return false;
2086 	if (type != BPF_READ)
2087 		return false;
2088 	if (off % size != 0) {
2089 		if (sizeof(unsigned long) != 4)
2090 			return false;
2091 		if (size != 8)
2092 			return false;
2093 		if (off % size != 4)
2094 			return false;
2095 	}
2096 
2097 	switch (off) {
2098 	case bpf_ctx_range(struct bpf_perf_event_data, sample_period):
2099 		bpf_ctx_record_field_size(info, size_u64);
2100 		if (!bpf_ctx_narrow_access_ok(off, size, size_u64))
2101 			return false;
2102 		break;
2103 	case bpf_ctx_range(struct bpf_perf_event_data, addr):
2104 		bpf_ctx_record_field_size(info, size_u64);
2105 		if (!bpf_ctx_narrow_access_ok(off, size, size_u64))
2106 			return false;
2107 		break;
2108 	default:
2109 		if (size != sizeof(long))
2110 			return false;
2111 	}
2112 
2113 	return true;
2114 }
2115 
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)2116 static u32 pe_prog_convert_ctx_access(enum bpf_access_type type,
2117 				      const struct bpf_insn *si,
2118 				      struct bpf_insn *insn_buf,
2119 				      struct bpf_prog *prog, u32 *target_size)
2120 {
2121 	struct bpf_insn *insn = insn_buf;
2122 
2123 	switch (si->off) {
2124 	case offsetof(struct bpf_perf_event_data, sample_period):
2125 		*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
2126 						       data), si->dst_reg, si->src_reg,
2127 				      offsetof(struct bpf_perf_event_data_kern, data));
2128 		*insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg,
2129 				      bpf_target_off(struct perf_sample_data, period, 8,
2130 						     target_size));
2131 		break;
2132 	case offsetof(struct bpf_perf_event_data, addr):
2133 		*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
2134 						       data), si->dst_reg, si->src_reg,
2135 				      offsetof(struct bpf_perf_event_data_kern, data));
2136 		*insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg,
2137 				      bpf_target_off(struct perf_sample_data, addr, 8,
2138 						     target_size));
2139 		break;
2140 	default:
2141 		*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
2142 						       regs), si->dst_reg, si->src_reg,
2143 				      offsetof(struct bpf_perf_event_data_kern, regs));
2144 		*insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg,
2145 				      si->off);
2146 		break;
2147 	}
2148 
2149 	return insn - insn_buf;
2150 }
2151 
2152 const struct bpf_verifier_ops perf_event_verifier_ops = {
2153 	.get_func_proto		= pe_prog_func_proto,
2154 	.is_valid_access	= pe_prog_is_valid_access,
2155 	.convert_ctx_access	= pe_prog_convert_ctx_access,
2156 };
2157 
2158 const struct bpf_prog_ops perf_event_prog_ops = {
2159 };
2160 
2161 static DEFINE_MUTEX(bpf_event_mutex);
2162 
2163 #define BPF_TRACE_MAX_PROGS 64
2164 
perf_event_attach_bpf_prog(struct perf_event * event,struct bpf_prog * prog,u64 bpf_cookie)2165 int perf_event_attach_bpf_prog(struct perf_event *event,
2166 			       struct bpf_prog *prog,
2167 			       u64 bpf_cookie)
2168 {
2169 	struct bpf_prog_array *old_array;
2170 	struct bpf_prog_array *new_array;
2171 	int ret = -EEXIST;
2172 
2173 	/*
2174 	 * Kprobe override only works if they are on the function entry,
2175 	 * and only if they are on the opt-in list.
2176 	 */
2177 	if (prog->kprobe_override &&
2178 	    (!trace_kprobe_on_func_entry(event->tp_event) ||
2179 	     !trace_kprobe_error_injectable(event->tp_event)))
2180 		return -EINVAL;
2181 
2182 	mutex_lock(&bpf_event_mutex);
2183 
2184 	if (event->prog)
2185 		goto unlock;
2186 
2187 	old_array = bpf_event_rcu_dereference(event->tp_event->prog_array);
2188 	if (old_array &&
2189 	    bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) {
2190 		ret = -E2BIG;
2191 		goto unlock;
2192 	}
2193 
2194 	ret = bpf_prog_array_copy(old_array, NULL, prog, bpf_cookie, &new_array);
2195 	if (ret < 0)
2196 		goto unlock;
2197 
2198 	/* set the new array to event->tp_event and set event->prog */
2199 	event->prog = prog;
2200 	event->bpf_cookie = bpf_cookie;
2201 	rcu_assign_pointer(event->tp_event->prog_array, new_array);
2202 	bpf_prog_array_free_sleepable(old_array);
2203 
2204 unlock:
2205 	mutex_unlock(&bpf_event_mutex);
2206 	return ret;
2207 }
2208 
perf_event_detach_bpf_prog(struct perf_event * event)2209 void perf_event_detach_bpf_prog(struct perf_event *event)
2210 {
2211 	struct bpf_prog_array *old_array;
2212 	struct bpf_prog_array *new_array;
2213 	int ret;
2214 
2215 	mutex_lock(&bpf_event_mutex);
2216 
2217 	if (!event->prog)
2218 		goto unlock;
2219 
2220 	old_array = bpf_event_rcu_dereference(event->tp_event->prog_array);
2221 	if (!old_array)
2222 		goto put;
2223 
2224 	ret = bpf_prog_array_copy(old_array, event->prog, NULL, 0, &new_array);
2225 	if (ret < 0) {
2226 		bpf_prog_array_delete_safe(old_array, event->prog);
2227 	} else {
2228 		rcu_assign_pointer(event->tp_event->prog_array, new_array);
2229 		bpf_prog_array_free_sleepable(old_array);
2230 	}
2231 
2232 put:
2233 	/*
2234 	 * It could be that the bpf_prog is not sleepable (and will be freed
2235 	 * via normal RCU), but is called from a point that supports sleepable
2236 	 * programs and uses tasks-trace-RCU.
2237 	 */
2238 	synchronize_rcu_tasks_trace();
2239 
2240 	bpf_prog_put(event->prog);
2241 	event->prog = NULL;
2242 
2243 unlock:
2244 	mutex_unlock(&bpf_event_mutex);
2245 }
2246 
perf_event_query_prog_array(struct perf_event * event,void __user * info)2247 int perf_event_query_prog_array(struct perf_event *event, void __user *info)
2248 {
2249 	struct perf_event_query_bpf __user *uquery = info;
2250 	struct perf_event_query_bpf query = {};
2251 	struct bpf_prog_array *progs;
2252 	u32 *ids, prog_cnt, ids_len;
2253 	int ret;
2254 
2255 	if (!perfmon_capable())
2256 		return -EPERM;
2257 	if (event->attr.type != PERF_TYPE_TRACEPOINT)
2258 		return -EINVAL;
2259 	if (copy_from_user(&query, uquery, sizeof(query)))
2260 		return -EFAULT;
2261 
2262 	ids_len = query.ids_len;
2263 	if (ids_len > BPF_TRACE_MAX_PROGS)
2264 		return -E2BIG;
2265 	ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN);
2266 	if (!ids)
2267 		return -ENOMEM;
2268 	/*
2269 	 * The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which
2270 	 * is required when user only wants to check for uquery->prog_cnt.
2271 	 * There is no need to check for it since the case is handled
2272 	 * gracefully in bpf_prog_array_copy_info.
2273 	 */
2274 
2275 	mutex_lock(&bpf_event_mutex);
2276 	progs = bpf_event_rcu_dereference(event->tp_event->prog_array);
2277 	ret = bpf_prog_array_copy_info(progs, ids, ids_len, &prog_cnt);
2278 	mutex_unlock(&bpf_event_mutex);
2279 
2280 	if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) ||
2281 	    copy_to_user(uquery->ids, ids, ids_len * sizeof(u32)))
2282 		ret = -EFAULT;
2283 
2284 	kfree(ids);
2285 	return ret;
2286 }
2287 
2288 extern struct bpf_raw_event_map __start__bpf_raw_tp[];
2289 extern struct bpf_raw_event_map __stop__bpf_raw_tp[];
2290 
bpf_get_raw_tracepoint(const char * name)2291 struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name)
2292 {
2293 	struct bpf_raw_event_map *btp = __start__bpf_raw_tp;
2294 
2295 	for (; btp < __stop__bpf_raw_tp; btp++) {
2296 		if (!strcmp(btp->tp->name, name))
2297 			return btp;
2298 	}
2299 
2300 	return bpf_get_raw_tracepoint_module(name);
2301 }
2302 
bpf_put_raw_tracepoint(struct bpf_raw_event_map * btp)2303 void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp)
2304 {
2305 	struct module *mod;
2306 
2307 	preempt_disable();
2308 	mod = __module_address((unsigned long)btp);
2309 	module_put(mod);
2310 	preempt_enable();
2311 }
2312 
2313 static __always_inline
__bpf_trace_run(struct bpf_prog * prog,u64 * args)2314 void __bpf_trace_run(struct bpf_prog *prog, u64 *args)
2315 {
2316 	cant_sleep();
2317 	if (unlikely(this_cpu_inc_return(*(prog->active)) != 1)) {
2318 		bpf_prog_inc_misses_counter(prog);
2319 		goto out;
2320 	}
2321 	rcu_read_lock();
2322 	(void) bpf_prog_run(prog, args);
2323 	rcu_read_unlock();
2324 out:
2325 	this_cpu_dec(*(prog->active));
2326 }
2327 
2328 #define UNPACK(...)			__VA_ARGS__
2329 #define REPEAT_1(FN, DL, X, ...)	FN(X)
2330 #define REPEAT_2(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__)
2331 #define REPEAT_3(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_2(FN, DL, __VA_ARGS__)
2332 #define REPEAT_4(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_3(FN, DL, __VA_ARGS__)
2333 #define REPEAT_5(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_4(FN, DL, __VA_ARGS__)
2334 #define REPEAT_6(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_5(FN, DL, __VA_ARGS__)
2335 #define REPEAT_7(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_6(FN, DL, __VA_ARGS__)
2336 #define REPEAT_8(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_7(FN, DL, __VA_ARGS__)
2337 #define REPEAT_9(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_8(FN, DL, __VA_ARGS__)
2338 #define REPEAT_10(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_9(FN, DL, __VA_ARGS__)
2339 #define REPEAT_11(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_10(FN, DL, __VA_ARGS__)
2340 #define REPEAT_12(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_11(FN, DL, __VA_ARGS__)
2341 #define REPEAT(X, FN, DL, ...)		REPEAT_##X(FN, DL, __VA_ARGS__)
2342 
2343 #define SARG(X)		u64 arg##X
2344 #define COPY(X)		args[X] = arg##X
2345 
2346 #define __DL_COM	(,)
2347 #define __DL_SEM	(;)
2348 
2349 #define __SEQ_0_11	0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11
2350 
2351 #define BPF_TRACE_DEFN_x(x)						\
2352 	void bpf_trace_run##x(struct bpf_prog *prog,			\
2353 			      REPEAT(x, SARG, __DL_COM, __SEQ_0_11))	\
2354 	{								\
2355 		u64 args[x];						\
2356 		REPEAT(x, COPY, __DL_SEM, __SEQ_0_11);			\
2357 		__bpf_trace_run(prog, args);				\
2358 	}								\
2359 	EXPORT_SYMBOL_GPL(bpf_trace_run##x)
2360 BPF_TRACE_DEFN_x(1);
2361 BPF_TRACE_DEFN_x(2);
2362 BPF_TRACE_DEFN_x(3);
2363 BPF_TRACE_DEFN_x(4);
2364 BPF_TRACE_DEFN_x(5);
2365 BPF_TRACE_DEFN_x(6);
2366 BPF_TRACE_DEFN_x(7);
2367 BPF_TRACE_DEFN_x(8);
2368 BPF_TRACE_DEFN_x(9);
2369 BPF_TRACE_DEFN_x(10);
2370 BPF_TRACE_DEFN_x(11);
2371 BPF_TRACE_DEFN_x(12);
2372 
__bpf_probe_register(struct bpf_raw_event_map * btp,struct bpf_prog * prog)2373 static int __bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog)
2374 {
2375 	struct tracepoint *tp = btp->tp;
2376 
2377 	/*
2378 	 * check that program doesn't access arguments beyond what's
2379 	 * available in this tracepoint
2380 	 */
2381 	if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64))
2382 		return -EINVAL;
2383 
2384 	if (prog->aux->max_tp_access > btp->writable_size)
2385 		return -EINVAL;
2386 
2387 	return tracepoint_probe_register_may_exist(tp, (void *)btp->bpf_func,
2388 						   prog);
2389 }
2390 
bpf_probe_register(struct bpf_raw_event_map * btp,struct bpf_prog * prog)2391 int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog)
2392 {
2393 	return __bpf_probe_register(btp, prog);
2394 }
2395 
bpf_probe_unregister(struct bpf_raw_event_map * btp,struct bpf_prog * prog)2396 int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_prog *prog)
2397 {
2398 	return tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, prog);
2399 }
2400 
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,unsigned long * missed)2401 int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id,
2402 			    u32 *fd_type, const char **buf,
2403 			    u64 *probe_offset, u64 *probe_addr,
2404 			    unsigned long *missed)
2405 {
2406 	bool is_tracepoint, is_syscall_tp;
2407 	struct bpf_prog *prog;
2408 	int flags, err = 0;
2409 
2410 	prog = event->prog;
2411 	if (!prog)
2412 		return -ENOENT;
2413 
2414 	/* not supporting BPF_PROG_TYPE_PERF_EVENT yet */
2415 	if (prog->type == BPF_PROG_TYPE_PERF_EVENT)
2416 		return -EOPNOTSUPP;
2417 
2418 	*prog_id = prog->aux->id;
2419 	flags = event->tp_event->flags;
2420 	is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT;
2421 	is_syscall_tp = is_syscall_trace_event(event->tp_event);
2422 
2423 	if (is_tracepoint || is_syscall_tp) {
2424 		*buf = is_tracepoint ? event->tp_event->tp->name
2425 				     : event->tp_event->name;
2426 		/* We allow NULL pointer for tracepoint */
2427 		if (fd_type)
2428 			*fd_type = BPF_FD_TYPE_TRACEPOINT;
2429 		if (probe_offset)
2430 			*probe_offset = 0x0;
2431 		if (probe_addr)
2432 			*probe_addr = 0x0;
2433 	} else {
2434 		/* kprobe/uprobe */
2435 		err = -EOPNOTSUPP;
2436 #ifdef CONFIG_KPROBE_EVENTS
2437 		if (flags & TRACE_EVENT_FL_KPROBE)
2438 			err = bpf_get_kprobe_info(event, fd_type, buf,
2439 						  probe_offset, probe_addr, missed,
2440 						  event->attr.type == PERF_TYPE_TRACEPOINT);
2441 #endif
2442 #ifdef CONFIG_UPROBE_EVENTS
2443 		if (flags & TRACE_EVENT_FL_UPROBE)
2444 			err = bpf_get_uprobe_info(event, fd_type, buf,
2445 						  probe_offset, probe_addr,
2446 						  event->attr.type == PERF_TYPE_TRACEPOINT);
2447 #endif
2448 	}
2449 
2450 	return err;
2451 }
2452 
send_signal_irq_work_init(void)2453 static int __init send_signal_irq_work_init(void)
2454 {
2455 	int cpu;
2456 	struct send_signal_irq_work *work;
2457 
2458 	for_each_possible_cpu(cpu) {
2459 		work = per_cpu_ptr(&send_signal_work, cpu);
2460 		init_irq_work(&work->irq_work, do_bpf_send_signal);
2461 	}
2462 	return 0;
2463 }
2464 
2465 subsys_initcall(send_signal_irq_work_init);
2466 
2467 #ifdef CONFIG_MODULES
bpf_event_notify(struct notifier_block * nb,unsigned long op,void * module)2468 static int bpf_event_notify(struct notifier_block *nb, unsigned long op,
2469 			    void *module)
2470 {
2471 	struct bpf_trace_module *btm, *tmp;
2472 	struct module *mod = module;
2473 	int ret = 0;
2474 
2475 	if (mod->num_bpf_raw_events == 0 ||
2476 	    (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING))
2477 		goto out;
2478 
2479 	mutex_lock(&bpf_module_mutex);
2480 
2481 	switch (op) {
2482 	case MODULE_STATE_COMING:
2483 		btm = kzalloc(sizeof(*btm), GFP_KERNEL);
2484 		if (btm) {
2485 			btm->module = module;
2486 			list_add(&btm->list, &bpf_trace_modules);
2487 		} else {
2488 			ret = -ENOMEM;
2489 		}
2490 		break;
2491 	case MODULE_STATE_GOING:
2492 		list_for_each_entry_safe(btm, tmp, &bpf_trace_modules, list) {
2493 			if (btm->module == module) {
2494 				list_del(&btm->list);
2495 				kfree(btm);
2496 				break;
2497 			}
2498 		}
2499 		break;
2500 	}
2501 
2502 	mutex_unlock(&bpf_module_mutex);
2503 
2504 out:
2505 	return notifier_from_errno(ret);
2506 }
2507 
2508 static struct notifier_block bpf_module_nb = {
2509 	.notifier_call = bpf_event_notify,
2510 };
2511 
bpf_event_init(void)2512 static int __init bpf_event_init(void)
2513 {
2514 	register_module_notifier(&bpf_module_nb);
2515 	return 0;
2516 }
2517 
2518 fs_initcall(bpf_event_init);
2519 #endif /* CONFIG_MODULES */
2520 
2521 #ifdef CONFIG_FPROBE
2522 struct bpf_kprobe_multi_link {
2523 	struct bpf_link link;
2524 	struct fprobe fp;
2525 	unsigned long *addrs;
2526 	u64 *cookies;
2527 	u32 cnt;
2528 	u32 mods_cnt;
2529 	struct module **mods;
2530 	u32 flags;
2531 };
2532 
2533 struct bpf_kprobe_multi_run_ctx {
2534 	struct bpf_run_ctx run_ctx;
2535 	struct bpf_kprobe_multi_link *link;
2536 	unsigned long entry_ip;
2537 };
2538 
2539 struct user_syms {
2540 	const char **syms;
2541 	char *buf;
2542 };
2543 
copy_user_syms(struct user_syms * us,unsigned long __user * usyms,u32 cnt)2544 static int copy_user_syms(struct user_syms *us, unsigned long __user *usyms, u32 cnt)
2545 {
2546 	unsigned long __user usymbol;
2547 	const char **syms = NULL;
2548 	char *buf = NULL, *p;
2549 	int err = -ENOMEM;
2550 	unsigned int i;
2551 
2552 	syms = kvmalloc_array(cnt, sizeof(*syms), GFP_KERNEL);
2553 	if (!syms)
2554 		goto error;
2555 
2556 	buf = kvmalloc_array(cnt, KSYM_NAME_LEN, GFP_KERNEL);
2557 	if (!buf)
2558 		goto error;
2559 
2560 	for (p = buf, i = 0; i < cnt; i++) {
2561 		if (__get_user(usymbol, usyms + i)) {
2562 			err = -EFAULT;
2563 			goto error;
2564 		}
2565 		err = strncpy_from_user(p, (const char __user *) usymbol, KSYM_NAME_LEN);
2566 		if (err == KSYM_NAME_LEN)
2567 			err = -E2BIG;
2568 		if (err < 0)
2569 			goto error;
2570 		syms[i] = p;
2571 		p += err + 1;
2572 	}
2573 
2574 	us->syms = syms;
2575 	us->buf = buf;
2576 	return 0;
2577 
2578 error:
2579 	if (err) {
2580 		kvfree(syms);
2581 		kvfree(buf);
2582 	}
2583 	return err;
2584 }
2585 
kprobe_multi_put_modules(struct module ** mods,u32 cnt)2586 static void kprobe_multi_put_modules(struct module **mods, u32 cnt)
2587 {
2588 	u32 i;
2589 
2590 	for (i = 0; i < cnt; i++)
2591 		module_put(mods[i]);
2592 }
2593 
free_user_syms(struct user_syms * us)2594 static void free_user_syms(struct user_syms *us)
2595 {
2596 	kvfree(us->syms);
2597 	kvfree(us->buf);
2598 }
2599 
bpf_kprobe_multi_link_release(struct bpf_link * link)2600 static void bpf_kprobe_multi_link_release(struct bpf_link *link)
2601 {
2602 	struct bpf_kprobe_multi_link *kmulti_link;
2603 
2604 	kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);
2605 	unregister_fprobe(&kmulti_link->fp);
2606 	kprobe_multi_put_modules(kmulti_link->mods, kmulti_link->mods_cnt);
2607 }
2608 
bpf_kprobe_multi_link_dealloc(struct bpf_link * link)2609 static void bpf_kprobe_multi_link_dealloc(struct bpf_link *link)
2610 {
2611 	struct bpf_kprobe_multi_link *kmulti_link;
2612 
2613 	kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);
2614 	kvfree(kmulti_link->addrs);
2615 	kvfree(kmulti_link->cookies);
2616 	kfree(kmulti_link->mods);
2617 	kfree(kmulti_link);
2618 }
2619 
bpf_kprobe_multi_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)2620 static int bpf_kprobe_multi_link_fill_link_info(const struct bpf_link *link,
2621 						struct bpf_link_info *info)
2622 {
2623 	u64 __user *uaddrs = u64_to_user_ptr(info->kprobe_multi.addrs);
2624 	struct bpf_kprobe_multi_link *kmulti_link;
2625 	u32 ucount = info->kprobe_multi.count;
2626 	int err = 0, i;
2627 
2628 	if (!uaddrs ^ !ucount)
2629 		return -EINVAL;
2630 
2631 	kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);
2632 	info->kprobe_multi.count = kmulti_link->cnt;
2633 	info->kprobe_multi.flags = kmulti_link->flags;
2634 
2635 	if (!uaddrs)
2636 		return 0;
2637 	if (ucount < kmulti_link->cnt)
2638 		err = -ENOSPC;
2639 	else
2640 		ucount = kmulti_link->cnt;
2641 
2642 	if (kallsyms_show_value(current_cred())) {
2643 		if (copy_to_user(uaddrs, kmulti_link->addrs, ucount * sizeof(u64)))
2644 			return -EFAULT;
2645 	} else {
2646 		for (i = 0; i < ucount; i++) {
2647 			if (put_user(0, uaddrs + i))
2648 				return -EFAULT;
2649 		}
2650 	}
2651 	return err;
2652 }
2653 
2654 static const struct bpf_link_ops bpf_kprobe_multi_link_lops = {
2655 	.release = bpf_kprobe_multi_link_release,
2656 	.dealloc_deferred = bpf_kprobe_multi_link_dealloc,
2657 	.fill_link_info = bpf_kprobe_multi_link_fill_link_info,
2658 };
2659 
bpf_kprobe_multi_cookie_swap(void * a,void * b,int size,const void * priv)2660 static void bpf_kprobe_multi_cookie_swap(void *a, void *b, int size, const void *priv)
2661 {
2662 	const struct bpf_kprobe_multi_link *link = priv;
2663 	unsigned long *addr_a = a, *addr_b = b;
2664 	u64 *cookie_a, *cookie_b;
2665 
2666 	cookie_a = link->cookies + (addr_a - link->addrs);
2667 	cookie_b = link->cookies + (addr_b - link->addrs);
2668 
2669 	/* swap addr_a/addr_b and cookie_a/cookie_b values */
2670 	swap(*addr_a, *addr_b);
2671 	swap(*cookie_a, *cookie_b);
2672 }
2673 
bpf_kprobe_multi_addrs_cmp(const void * a,const void * b)2674 static int bpf_kprobe_multi_addrs_cmp(const void *a, const void *b)
2675 {
2676 	const unsigned long *addr_a = a, *addr_b = b;
2677 
2678 	if (*addr_a == *addr_b)
2679 		return 0;
2680 	return *addr_a < *addr_b ? -1 : 1;
2681 }
2682 
bpf_kprobe_multi_cookie_cmp(const void * a,const void * b,const void * priv)2683 static int bpf_kprobe_multi_cookie_cmp(const void *a, const void *b, const void *priv)
2684 {
2685 	return bpf_kprobe_multi_addrs_cmp(a, b);
2686 }
2687 
bpf_kprobe_multi_cookie(struct bpf_run_ctx * ctx)2688 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx)
2689 {
2690 	struct bpf_kprobe_multi_run_ctx *run_ctx;
2691 	struct bpf_kprobe_multi_link *link;
2692 	u64 *cookie, entry_ip;
2693 	unsigned long *addr;
2694 
2695 	if (WARN_ON_ONCE(!ctx))
2696 		return 0;
2697 	run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, run_ctx);
2698 	link = run_ctx->link;
2699 	if (!link->cookies)
2700 		return 0;
2701 	entry_ip = run_ctx->entry_ip;
2702 	addr = bsearch(&entry_ip, link->addrs, link->cnt, sizeof(entry_ip),
2703 		       bpf_kprobe_multi_addrs_cmp);
2704 	if (!addr)
2705 		return 0;
2706 	cookie = link->cookies + (addr - link->addrs);
2707 	return *cookie;
2708 }
2709 
bpf_kprobe_multi_entry_ip(struct bpf_run_ctx * ctx)2710 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
2711 {
2712 	struct bpf_kprobe_multi_run_ctx *run_ctx;
2713 
2714 	run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, run_ctx);
2715 	return run_ctx->entry_ip;
2716 }
2717 
2718 static int
kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link * link,unsigned long entry_ip,struct pt_regs * regs)2719 kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link,
2720 			   unsigned long entry_ip, struct pt_regs *regs)
2721 {
2722 	struct bpf_kprobe_multi_run_ctx run_ctx = {
2723 		.link = link,
2724 		.entry_ip = entry_ip,
2725 	};
2726 	struct bpf_run_ctx *old_run_ctx;
2727 	int err;
2728 
2729 	if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) {
2730 		err = 0;
2731 		goto out;
2732 	}
2733 
2734 	migrate_disable();
2735 	rcu_read_lock();
2736 	old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx);
2737 	err = bpf_prog_run(link->link.prog, regs);
2738 	bpf_reset_run_ctx(old_run_ctx);
2739 	rcu_read_unlock();
2740 	migrate_enable();
2741 
2742  out:
2743 	__this_cpu_dec(bpf_prog_active);
2744 	return err;
2745 }
2746 
2747 static int
kprobe_multi_link_handler(struct fprobe * fp,unsigned long fentry_ip,unsigned long ret_ip,struct pt_regs * regs,void * data)2748 kprobe_multi_link_handler(struct fprobe *fp, unsigned long fentry_ip,
2749 			  unsigned long ret_ip, struct pt_regs *regs,
2750 			  void *data)
2751 {
2752 	struct bpf_kprobe_multi_link *link;
2753 
2754 	link = container_of(fp, struct bpf_kprobe_multi_link, fp);
2755 	kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), regs);
2756 	return 0;
2757 }
2758 
2759 static void
kprobe_multi_link_exit_handler(struct fprobe * fp,unsigned long fentry_ip,unsigned long ret_ip,struct pt_regs * regs,void * data)2760 kprobe_multi_link_exit_handler(struct fprobe *fp, unsigned long fentry_ip,
2761 			       unsigned long ret_ip, struct pt_regs *regs,
2762 			       void *data)
2763 {
2764 	struct bpf_kprobe_multi_link *link;
2765 
2766 	link = container_of(fp, struct bpf_kprobe_multi_link, fp);
2767 	kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), regs);
2768 }
2769 
symbols_cmp_r(const void * a,const void * b,const void * priv)2770 static int symbols_cmp_r(const void *a, const void *b, const void *priv)
2771 {
2772 	const char **str_a = (const char **) a;
2773 	const char **str_b = (const char **) b;
2774 
2775 	return strcmp(*str_a, *str_b);
2776 }
2777 
2778 struct multi_symbols_sort {
2779 	const char **funcs;
2780 	u64 *cookies;
2781 };
2782 
symbols_swap_r(void * a,void * b,int size,const void * priv)2783 static void symbols_swap_r(void *a, void *b, int size, const void *priv)
2784 {
2785 	const struct multi_symbols_sort *data = priv;
2786 	const char **name_a = a, **name_b = b;
2787 
2788 	swap(*name_a, *name_b);
2789 
2790 	/* If defined, swap also related cookies. */
2791 	if (data->cookies) {
2792 		u64 *cookie_a, *cookie_b;
2793 
2794 		cookie_a = data->cookies + (name_a - data->funcs);
2795 		cookie_b = data->cookies + (name_b - data->funcs);
2796 		swap(*cookie_a, *cookie_b);
2797 	}
2798 }
2799 
2800 struct modules_array {
2801 	struct module **mods;
2802 	int mods_cnt;
2803 	int mods_cap;
2804 };
2805 
add_module(struct modules_array * arr,struct module * mod)2806 static int add_module(struct modules_array *arr, struct module *mod)
2807 {
2808 	struct module **mods;
2809 
2810 	if (arr->mods_cnt == arr->mods_cap) {
2811 		arr->mods_cap = max(16, arr->mods_cap * 3 / 2);
2812 		mods = krealloc_array(arr->mods, arr->mods_cap, sizeof(*mods), GFP_KERNEL);
2813 		if (!mods)
2814 			return -ENOMEM;
2815 		arr->mods = mods;
2816 	}
2817 
2818 	arr->mods[arr->mods_cnt] = mod;
2819 	arr->mods_cnt++;
2820 	return 0;
2821 }
2822 
has_module(struct modules_array * arr,struct module * mod)2823 static bool has_module(struct modules_array *arr, struct module *mod)
2824 {
2825 	int i;
2826 
2827 	for (i = arr->mods_cnt - 1; i >= 0; i--) {
2828 		if (arr->mods[i] == mod)
2829 			return true;
2830 	}
2831 	return false;
2832 }
2833 
get_modules_for_addrs(struct module *** mods,unsigned long * addrs,u32 addrs_cnt)2834 static int get_modules_for_addrs(struct module ***mods, unsigned long *addrs, u32 addrs_cnt)
2835 {
2836 	struct modules_array arr = {};
2837 	u32 i, err = 0;
2838 
2839 	for (i = 0; i < addrs_cnt; i++) {
2840 		struct module *mod;
2841 
2842 		preempt_disable();
2843 		mod = __module_address(addrs[i]);
2844 		/* Either no module or we it's already stored  */
2845 		if (!mod || has_module(&arr, mod)) {
2846 			preempt_enable();
2847 			continue;
2848 		}
2849 		if (!try_module_get(mod))
2850 			err = -EINVAL;
2851 		preempt_enable();
2852 		if (err)
2853 			break;
2854 		err = add_module(&arr, mod);
2855 		if (err) {
2856 			module_put(mod);
2857 			break;
2858 		}
2859 	}
2860 
2861 	/* We return either err < 0 in case of error, ... */
2862 	if (err) {
2863 		kprobe_multi_put_modules(arr.mods, arr.mods_cnt);
2864 		kfree(arr.mods);
2865 		return err;
2866 	}
2867 
2868 	/* or number of modules found if everything is ok. */
2869 	*mods = arr.mods;
2870 	return arr.mods_cnt;
2871 }
2872 
addrs_check_error_injection_list(unsigned long * addrs,u32 cnt)2873 static int addrs_check_error_injection_list(unsigned long *addrs, u32 cnt)
2874 {
2875 	u32 i;
2876 
2877 	for (i = 0; i < cnt; i++) {
2878 		if (!within_error_injection_list(addrs[i]))
2879 			return -EINVAL;
2880 	}
2881 	return 0;
2882 }
2883 
bpf_kprobe_multi_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)2884 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
2885 {
2886 	struct bpf_kprobe_multi_link *link = NULL;
2887 	struct bpf_link_primer link_primer;
2888 	void __user *ucookies;
2889 	unsigned long *addrs;
2890 	u32 flags, cnt, size;
2891 	void __user *uaddrs;
2892 	u64 *cookies = NULL;
2893 	void __user *usyms;
2894 	int err;
2895 
2896 	/* no support for 32bit archs yet */
2897 	if (sizeof(u64) != sizeof(void *))
2898 		return -EOPNOTSUPP;
2899 
2900 	if (prog->expected_attach_type != BPF_TRACE_KPROBE_MULTI)
2901 		return -EINVAL;
2902 
2903 	flags = attr->link_create.kprobe_multi.flags;
2904 	if (flags & ~BPF_F_KPROBE_MULTI_RETURN)
2905 		return -EINVAL;
2906 
2907 	uaddrs = u64_to_user_ptr(attr->link_create.kprobe_multi.addrs);
2908 	usyms = u64_to_user_ptr(attr->link_create.kprobe_multi.syms);
2909 	if (!!uaddrs == !!usyms)
2910 		return -EINVAL;
2911 
2912 	cnt = attr->link_create.kprobe_multi.cnt;
2913 	if (!cnt)
2914 		return -EINVAL;
2915 	if (cnt > MAX_KPROBE_MULTI_CNT)
2916 		return -E2BIG;
2917 
2918 	size = cnt * sizeof(*addrs);
2919 	addrs = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL);
2920 	if (!addrs)
2921 		return -ENOMEM;
2922 
2923 	ucookies = u64_to_user_ptr(attr->link_create.kprobe_multi.cookies);
2924 	if (ucookies) {
2925 		cookies = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL);
2926 		if (!cookies) {
2927 			err = -ENOMEM;
2928 			goto error;
2929 		}
2930 		if (copy_from_user(cookies, ucookies, size)) {
2931 			err = -EFAULT;
2932 			goto error;
2933 		}
2934 	}
2935 
2936 	if (uaddrs) {
2937 		if (copy_from_user(addrs, uaddrs, size)) {
2938 			err = -EFAULT;
2939 			goto error;
2940 		}
2941 	} else {
2942 		struct multi_symbols_sort data = {
2943 			.cookies = cookies,
2944 		};
2945 		struct user_syms us;
2946 
2947 		err = copy_user_syms(&us, usyms, cnt);
2948 		if (err)
2949 			goto error;
2950 
2951 		if (cookies)
2952 			data.funcs = us.syms;
2953 
2954 		sort_r(us.syms, cnt, sizeof(*us.syms), symbols_cmp_r,
2955 		       symbols_swap_r, &data);
2956 
2957 		err = ftrace_lookup_symbols(us.syms, cnt, addrs);
2958 		free_user_syms(&us);
2959 		if (err)
2960 			goto error;
2961 	}
2962 
2963 	if (prog->kprobe_override && addrs_check_error_injection_list(addrs, cnt)) {
2964 		err = -EINVAL;
2965 		goto error;
2966 	}
2967 
2968 	link = kzalloc(sizeof(*link), GFP_KERNEL);
2969 	if (!link) {
2970 		err = -ENOMEM;
2971 		goto error;
2972 	}
2973 
2974 	bpf_link_init(&link->link, BPF_LINK_TYPE_KPROBE_MULTI,
2975 		      &bpf_kprobe_multi_link_lops, prog);
2976 
2977 	err = bpf_link_prime(&link->link, &link_primer);
2978 	if (err)
2979 		goto error;
2980 
2981 	if (flags & BPF_F_KPROBE_MULTI_RETURN)
2982 		link->fp.exit_handler = kprobe_multi_link_exit_handler;
2983 	else
2984 		link->fp.entry_handler = kprobe_multi_link_handler;
2985 
2986 	link->addrs = addrs;
2987 	link->cookies = cookies;
2988 	link->cnt = cnt;
2989 	link->flags = flags;
2990 
2991 	if (cookies) {
2992 		/*
2993 		 * Sorting addresses will trigger sorting cookies as well
2994 		 * (check bpf_kprobe_multi_cookie_swap). This way we can
2995 		 * find cookie based on the address in bpf_get_attach_cookie
2996 		 * helper.
2997 		 */
2998 		sort_r(addrs, cnt, sizeof(*addrs),
2999 		       bpf_kprobe_multi_cookie_cmp,
3000 		       bpf_kprobe_multi_cookie_swap,
3001 		       link);
3002 	}
3003 
3004 	err = get_modules_for_addrs(&link->mods, addrs, cnt);
3005 	if (err < 0) {
3006 		bpf_link_cleanup(&link_primer);
3007 		return err;
3008 	}
3009 	link->mods_cnt = err;
3010 
3011 	err = register_fprobe_ips(&link->fp, addrs, cnt);
3012 	if (err) {
3013 		kprobe_multi_put_modules(link->mods, link->mods_cnt);
3014 		bpf_link_cleanup(&link_primer);
3015 		return err;
3016 	}
3017 
3018 	return bpf_link_settle(&link_primer);
3019 
3020 error:
3021 	kfree(link);
3022 	kvfree(addrs);
3023 	kvfree(cookies);
3024 	return err;
3025 }
3026 #else /* !CONFIG_FPROBE */
bpf_kprobe_multi_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)3027 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
3028 {
3029 	return -EOPNOTSUPP;
3030 }
bpf_kprobe_multi_cookie(struct bpf_run_ctx * ctx)3031 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx)
3032 {
3033 	return 0;
3034 }
bpf_kprobe_multi_entry_ip(struct bpf_run_ctx * ctx)3035 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
3036 {
3037 	return 0;
3038 }
3039 #endif
3040 
3041 #ifdef CONFIG_UPROBES
3042 struct bpf_uprobe_multi_link;
3043 
3044 struct bpf_uprobe {
3045 	struct bpf_uprobe_multi_link *link;
3046 	loff_t offset;
3047 	unsigned long ref_ctr_offset;
3048 	u64 cookie;
3049 	struct uprobe_consumer consumer;
3050 };
3051 
3052 struct bpf_uprobe_multi_link {
3053 	struct path path;
3054 	struct bpf_link link;
3055 	u32 cnt;
3056 	struct bpf_uprobe *uprobes;
3057 	struct task_struct *task;
3058 };
3059 
3060 struct bpf_uprobe_multi_run_ctx {
3061 	struct bpf_run_ctx run_ctx;
3062 	unsigned long entry_ip;
3063 	struct bpf_uprobe *uprobe;
3064 };
3065 
bpf_uprobe_unregister(struct path * path,struct bpf_uprobe * uprobes,u32 cnt)3066 static void bpf_uprobe_unregister(struct path *path, struct bpf_uprobe *uprobes,
3067 				  u32 cnt)
3068 {
3069 	u32 i;
3070 
3071 	for (i = 0; i < cnt; i++) {
3072 		uprobe_unregister(d_real_inode(path->dentry), uprobes[i].offset,
3073 				  &uprobes[i].consumer);
3074 	}
3075 }
3076 
bpf_uprobe_multi_link_release(struct bpf_link * link)3077 static void bpf_uprobe_multi_link_release(struct bpf_link *link)
3078 {
3079 	struct bpf_uprobe_multi_link *umulti_link;
3080 
3081 	umulti_link = container_of(link, struct bpf_uprobe_multi_link, link);
3082 	bpf_uprobe_unregister(&umulti_link->path, umulti_link->uprobes, umulti_link->cnt);
3083 	if (umulti_link->task)
3084 		put_task_struct(umulti_link->task);
3085 	path_put(&umulti_link->path);
3086 }
3087 
bpf_uprobe_multi_link_dealloc(struct bpf_link * link)3088 static void bpf_uprobe_multi_link_dealloc(struct bpf_link *link)
3089 {
3090 	struct bpf_uprobe_multi_link *umulti_link;
3091 
3092 	umulti_link = container_of(link, struct bpf_uprobe_multi_link, link);
3093 	kvfree(umulti_link->uprobes);
3094 	kfree(umulti_link);
3095 }
3096 
3097 static const struct bpf_link_ops bpf_uprobe_multi_link_lops = {
3098 	.release = bpf_uprobe_multi_link_release,
3099 	.dealloc_deferred = bpf_uprobe_multi_link_dealloc,
3100 };
3101 
uprobe_prog_run(struct bpf_uprobe * uprobe,unsigned long entry_ip,struct pt_regs * regs)3102 static int uprobe_prog_run(struct bpf_uprobe *uprobe,
3103 			   unsigned long entry_ip,
3104 			   struct pt_regs *regs)
3105 {
3106 	struct bpf_uprobe_multi_link *link = uprobe->link;
3107 	struct bpf_uprobe_multi_run_ctx run_ctx = {
3108 		.entry_ip = entry_ip,
3109 		.uprobe = uprobe,
3110 	};
3111 	struct bpf_prog *prog = link->link.prog;
3112 	bool sleepable = prog->aux->sleepable;
3113 	struct bpf_run_ctx *old_run_ctx;
3114 
3115 	if (link->task && current->mm != link->task->mm)
3116 		return 0;
3117 
3118 	if (sleepable)
3119 		rcu_read_lock_trace();
3120 	else
3121 		rcu_read_lock();
3122 
3123 	migrate_disable();
3124 
3125 	old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx);
3126 	bpf_prog_run(link->link.prog, regs);
3127 	bpf_reset_run_ctx(old_run_ctx);
3128 
3129 	migrate_enable();
3130 
3131 	if (sleepable)
3132 		rcu_read_unlock_trace();
3133 	else
3134 		rcu_read_unlock();
3135 	return 0;
3136 }
3137 
3138 static bool
uprobe_multi_link_filter(struct uprobe_consumer * con,enum uprobe_filter_ctx ctx,struct mm_struct * mm)3139 uprobe_multi_link_filter(struct uprobe_consumer *con, enum uprobe_filter_ctx ctx,
3140 			 struct mm_struct *mm)
3141 {
3142 	struct bpf_uprobe *uprobe;
3143 
3144 	uprobe = container_of(con, struct bpf_uprobe, consumer);
3145 	return uprobe->link->task->mm == mm;
3146 }
3147 
3148 static int
uprobe_multi_link_handler(struct uprobe_consumer * con,struct pt_regs * regs)3149 uprobe_multi_link_handler(struct uprobe_consumer *con, struct pt_regs *regs)
3150 {
3151 	struct bpf_uprobe *uprobe;
3152 
3153 	uprobe = container_of(con, struct bpf_uprobe, consumer);
3154 	return uprobe_prog_run(uprobe, instruction_pointer(regs), regs);
3155 }
3156 
3157 static int
uprobe_multi_link_ret_handler(struct uprobe_consumer * con,unsigned long func,struct pt_regs * regs)3158 uprobe_multi_link_ret_handler(struct uprobe_consumer *con, unsigned long func, struct pt_regs *regs)
3159 {
3160 	struct bpf_uprobe *uprobe;
3161 
3162 	uprobe = container_of(con, struct bpf_uprobe, consumer);
3163 	return uprobe_prog_run(uprobe, func, regs);
3164 }
3165 
bpf_uprobe_multi_entry_ip(struct bpf_run_ctx * ctx)3166 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
3167 {
3168 	struct bpf_uprobe_multi_run_ctx *run_ctx;
3169 
3170 	run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx, run_ctx);
3171 	return run_ctx->entry_ip;
3172 }
3173 
bpf_uprobe_multi_cookie(struct bpf_run_ctx * ctx)3174 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx)
3175 {
3176 	struct bpf_uprobe_multi_run_ctx *run_ctx;
3177 
3178 	run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx, run_ctx);
3179 	return run_ctx->uprobe->cookie;
3180 }
3181 
bpf_uprobe_multi_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)3182 int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
3183 {
3184 	struct bpf_uprobe_multi_link *link = NULL;
3185 	unsigned long __user *uref_ctr_offsets;
3186 	struct bpf_link_primer link_primer;
3187 	struct bpf_uprobe *uprobes = NULL;
3188 	struct task_struct *task = NULL;
3189 	unsigned long __user *uoffsets;
3190 	u64 __user *ucookies;
3191 	void __user *upath;
3192 	u32 flags, cnt, i;
3193 	struct path path;
3194 	char *name;
3195 	pid_t pid;
3196 	int err;
3197 
3198 	/* no support for 32bit archs yet */
3199 	if (sizeof(u64) != sizeof(void *))
3200 		return -EOPNOTSUPP;
3201 
3202 	if (prog->expected_attach_type != BPF_TRACE_UPROBE_MULTI)
3203 		return -EINVAL;
3204 
3205 	flags = attr->link_create.uprobe_multi.flags;
3206 	if (flags & ~BPF_F_UPROBE_MULTI_RETURN)
3207 		return -EINVAL;
3208 
3209 	/*
3210 	 * path, offsets and cnt are mandatory,
3211 	 * ref_ctr_offsets and cookies are optional
3212 	 */
3213 	upath = u64_to_user_ptr(attr->link_create.uprobe_multi.path);
3214 	uoffsets = u64_to_user_ptr(attr->link_create.uprobe_multi.offsets);
3215 	cnt = attr->link_create.uprobe_multi.cnt;
3216 	pid = attr->link_create.uprobe_multi.pid;
3217 
3218 	if (!upath || !uoffsets || !cnt || pid < 0)
3219 		return -EINVAL;
3220 	if (cnt > MAX_UPROBE_MULTI_CNT)
3221 		return -E2BIG;
3222 
3223 	uref_ctr_offsets = u64_to_user_ptr(attr->link_create.uprobe_multi.ref_ctr_offsets);
3224 	ucookies = u64_to_user_ptr(attr->link_create.uprobe_multi.cookies);
3225 
3226 	name = strndup_user(upath, PATH_MAX);
3227 	if (IS_ERR(name)) {
3228 		err = PTR_ERR(name);
3229 		return err;
3230 	}
3231 
3232 	err = kern_path(name, LOOKUP_FOLLOW, &path);
3233 	kfree(name);
3234 	if (err)
3235 		return err;
3236 
3237 	if (!d_is_reg(path.dentry)) {
3238 		err = -EBADF;
3239 		goto error_path_put;
3240 	}
3241 
3242 	if (pid) {
3243 		rcu_read_lock();
3244 		task = get_pid_task(find_vpid(pid), PIDTYPE_TGID);
3245 		rcu_read_unlock();
3246 		if (!task) {
3247 			err = -ESRCH;
3248 			goto error_path_put;
3249 		}
3250 	}
3251 
3252 	err = -ENOMEM;
3253 
3254 	link = kzalloc(sizeof(*link), GFP_KERNEL);
3255 	uprobes = kvcalloc(cnt, sizeof(*uprobes), GFP_KERNEL);
3256 
3257 	if (!uprobes || !link)
3258 		goto error_free;
3259 
3260 	for (i = 0; i < cnt; i++) {
3261 		if (ucookies && __get_user(uprobes[i].cookie, ucookies + i)) {
3262 			err = -EFAULT;
3263 			goto error_free;
3264 		}
3265 		if (uref_ctr_offsets && __get_user(uprobes[i].ref_ctr_offset, uref_ctr_offsets + i)) {
3266 			err = -EFAULT;
3267 			goto error_free;
3268 		}
3269 		if (__get_user(uprobes[i].offset, uoffsets + i)) {
3270 			err = -EFAULT;
3271 			goto error_free;
3272 		}
3273 
3274 		uprobes[i].link = link;
3275 
3276 		if (flags & BPF_F_UPROBE_MULTI_RETURN)
3277 			uprobes[i].consumer.ret_handler = uprobe_multi_link_ret_handler;
3278 		else
3279 			uprobes[i].consumer.handler = uprobe_multi_link_handler;
3280 
3281 		if (pid)
3282 			uprobes[i].consumer.filter = uprobe_multi_link_filter;
3283 	}
3284 
3285 	link->cnt = cnt;
3286 	link->uprobes = uprobes;
3287 	link->path = path;
3288 	link->task = task;
3289 
3290 	bpf_link_init(&link->link, BPF_LINK_TYPE_UPROBE_MULTI,
3291 		      &bpf_uprobe_multi_link_lops, prog);
3292 
3293 	for (i = 0; i < cnt; i++) {
3294 		err = uprobe_register_refctr(d_real_inode(link->path.dentry),
3295 					     uprobes[i].offset,
3296 					     uprobes[i].ref_ctr_offset,
3297 					     &uprobes[i].consumer);
3298 		if (err) {
3299 			link->cnt = i;
3300 			goto error_unregister;
3301 		}
3302 	}
3303 
3304 	err = bpf_link_prime(&link->link, &link_primer);
3305 	if (err)
3306 		goto error_unregister;
3307 
3308 	return bpf_link_settle(&link_primer);
3309 
3310 error_unregister:
3311 	bpf_uprobe_unregister(&path, uprobes, link->cnt);
3312 
3313 error_free:
3314 	kvfree(uprobes);
3315 	kfree(link);
3316 	if (task)
3317 		put_task_struct(task);
3318 error_path_put:
3319 	path_put(&path);
3320 	return err;
3321 }
3322 #else /* !CONFIG_UPROBES */
bpf_uprobe_multi_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)3323 int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
3324 {
3325 	return -EOPNOTSUPP;
3326 }
bpf_uprobe_multi_cookie(struct bpf_run_ctx * ctx)3327 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx)
3328 {
3329 	return 0;
3330 }
bpf_uprobe_multi_entry_ip(struct bpf_run_ctx * ctx)3331 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
3332 {
3333 	return 0;
3334 }
3335 #endif /* CONFIG_UPROBES */
3336