xref: /linux/kernel/trace/bpf_trace.c (revision ae90f6a6170d7a7a1aa4fddf664fbd093e3023bc)
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 		rcu_read_lock();
124 		bpf_prog_inc_misses_counters(rcu_dereference(call->prog_array));
125 		rcu_read_unlock();
126 		ret = 0;
127 		goto out;
128 	}
129 
130 	/*
131 	 * Instead of moving rcu_read_lock/rcu_dereference/rcu_read_unlock
132 	 * to all call sites, we did a bpf_prog_array_valid() there to check
133 	 * whether call->prog_array is empty or not, which is
134 	 * a heuristic to speed up execution.
135 	 *
136 	 * If bpf_prog_array_valid() fetched prog_array was
137 	 * non-NULL, we go into trace_call_bpf() and do the actual
138 	 * proper rcu_dereference() under RCU lock.
139 	 * If it turns out that prog_array is NULL then, we bail out.
140 	 * For the opposite, if the bpf_prog_array_valid() fetched pointer
141 	 * was NULL, you'll skip the prog_array with the risk of missing
142 	 * out of events when it was updated in between this and the
143 	 * rcu_dereference() which is accepted risk.
144 	 */
145 	rcu_read_lock();
146 	ret = bpf_prog_run_array(rcu_dereference(call->prog_array),
147 				 ctx, bpf_prog_run);
148 	rcu_read_unlock();
149 
150  out:
151 	__this_cpu_dec(bpf_prog_active);
152 
153 	return ret;
154 }
155 
156 #ifdef CONFIG_BPF_KPROBE_OVERRIDE
BPF_CALL_2(bpf_override_return,struct pt_regs *,regs,unsigned long,rc)157 BPF_CALL_2(bpf_override_return, struct pt_regs *, regs, unsigned long, rc)
158 {
159 	regs_set_return_value(regs, rc);
160 	override_function_with_return(regs);
161 	return 0;
162 }
163 
164 static const struct bpf_func_proto bpf_override_return_proto = {
165 	.func		= bpf_override_return,
166 	.gpl_only	= true,
167 	.ret_type	= RET_INTEGER,
168 	.arg1_type	= ARG_PTR_TO_CTX,
169 	.arg2_type	= ARG_ANYTHING,
170 };
171 #endif
172 
173 static __always_inline int
bpf_probe_read_user_common(void * dst,u32 size,const void __user * unsafe_ptr)174 bpf_probe_read_user_common(void *dst, u32 size, const void __user *unsafe_ptr)
175 {
176 	int ret;
177 
178 	ret = copy_from_user_nofault(dst, unsafe_ptr, size);
179 	if (unlikely(ret < 0))
180 		memset(dst, 0, size);
181 	return ret;
182 }
183 
BPF_CALL_3(bpf_probe_read_user,void *,dst,u32,size,const void __user *,unsafe_ptr)184 BPF_CALL_3(bpf_probe_read_user, void *, dst, u32, size,
185 	   const void __user *, unsafe_ptr)
186 {
187 	return bpf_probe_read_user_common(dst, size, unsafe_ptr);
188 }
189 
190 const struct bpf_func_proto bpf_probe_read_user_proto = {
191 	.func		= bpf_probe_read_user,
192 	.gpl_only	= true,
193 	.ret_type	= RET_INTEGER,
194 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
195 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
196 	.arg3_type	= ARG_ANYTHING,
197 };
198 
199 static __always_inline int
bpf_probe_read_user_str_common(void * dst,u32 size,const void __user * unsafe_ptr)200 bpf_probe_read_user_str_common(void *dst, u32 size,
201 			       const void __user *unsafe_ptr)
202 {
203 	int ret;
204 
205 	/*
206 	 * NB: We rely on strncpy_from_user() not copying junk past the NUL
207 	 * terminator into `dst`.
208 	 *
209 	 * strncpy_from_user() does long-sized strides in the fast path. If the
210 	 * strncpy does not mask out the bytes after the NUL in `unsafe_ptr`,
211 	 * then there could be junk after the NUL in `dst`. If user takes `dst`
212 	 * and keys a hash map with it, then semantically identical strings can
213 	 * occupy multiple entries in the map.
214 	 */
215 	ret = strncpy_from_user_nofault(dst, unsafe_ptr, size);
216 	if (unlikely(ret < 0))
217 		memset(dst, 0, size);
218 	return ret;
219 }
220 
BPF_CALL_3(bpf_probe_read_user_str,void *,dst,u32,size,const void __user *,unsafe_ptr)221 BPF_CALL_3(bpf_probe_read_user_str, void *, dst, u32, size,
222 	   const void __user *, unsafe_ptr)
223 {
224 	return bpf_probe_read_user_str_common(dst, size, unsafe_ptr);
225 }
226 
227 const struct bpf_func_proto bpf_probe_read_user_str_proto = {
228 	.func		= bpf_probe_read_user_str,
229 	.gpl_only	= true,
230 	.ret_type	= RET_INTEGER,
231 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
232 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
233 	.arg3_type	= ARG_ANYTHING,
234 };
235 
BPF_CALL_3(bpf_probe_read_kernel,void *,dst,u32,size,const void *,unsafe_ptr)236 BPF_CALL_3(bpf_probe_read_kernel, void *, dst, u32, size,
237 	   const void *, unsafe_ptr)
238 {
239 	return bpf_probe_read_kernel_common(dst, size, unsafe_ptr);
240 }
241 
242 const struct bpf_func_proto bpf_probe_read_kernel_proto = {
243 	.func		= bpf_probe_read_kernel,
244 	.gpl_only	= true,
245 	.ret_type	= RET_INTEGER,
246 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
247 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
248 	.arg3_type	= ARG_ANYTHING,
249 };
250 
251 static __always_inline int
bpf_probe_read_kernel_str_common(void * dst,u32 size,const void * unsafe_ptr)252 bpf_probe_read_kernel_str_common(void *dst, u32 size, const void *unsafe_ptr)
253 {
254 	int ret;
255 
256 	/*
257 	 * The strncpy_from_kernel_nofault() call will likely not fill the
258 	 * entire buffer, but that's okay in this circumstance as we're probing
259 	 * arbitrary memory anyway similar to bpf_probe_read_*() and might
260 	 * as well probe the stack. Thus, memory is explicitly cleared
261 	 * only in error case, so that improper users ignoring return
262 	 * code altogether don't copy garbage; otherwise length of string
263 	 * is returned that can be used for bpf_perf_event_output() et al.
264 	 */
265 	ret = strncpy_from_kernel_nofault(dst, unsafe_ptr, size);
266 	if (unlikely(ret < 0))
267 		memset(dst, 0, size);
268 	return ret;
269 }
270 
BPF_CALL_3(bpf_probe_read_kernel_str,void *,dst,u32,size,const void *,unsafe_ptr)271 BPF_CALL_3(bpf_probe_read_kernel_str, void *, dst, u32, size,
272 	   const void *, unsafe_ptr)
273 {
274 	return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr);
275 }
276 
277 const struct bpf_func_proto bpf_probe_read_kernel_str_proto = {
278 	.func		= bpf_probe_read_kernel_str,
279 	.gpl_only	= true,
280 	.ret_type	= RET_INTEGER,
281 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
282 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
283 	.arg3_type	= ARG_ANYTHING,
284 };
285 
286 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
BPF_CALL_3(bpf_probe_read_compat,void *,dst,u32,size,const void *,unsafe_ptr)287 BPF_CALL_3(bpf_probe_read_compat, void *, dst, u32, size,
288 	   const void *, unsafe_ptr)
289 {
290 	if ((unsigned long)unsafe_ptr < TASK_SIZE) {
291 		return bpf_probe_read_user_common(dst, size,
292 				(__force void __user *)unsafe_ptr);
293 	}
294 	return bpf_probe_read_kernel_common(dst, size, unsafe_ptr);
295 }
296 
297 static const struct bpf_func_proto bpf_probe_read_compat_proto = {
298 	.func		= bpf_probe_read_compat,
299 	.gpl_only	= true,
300 	.ret_type	= RET_INTEGER,
301 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
302 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
303 	.arg3_type	= ARG_ANYTHING,
304 };
305 
BPF_CALL_3(bpf_probe_read_compat_str,void *,dst,u32,size,const void *,unsafe_ptr)306 BPF_CALL_3(bpf_probe_read_compat_str, void *, dst, u32, size,
307 	   const void *, unsafe_ptr)
308 {
309 	if ((unsigned long)unsafe_ptr < TASK_SIZE) {
310 		return bpf_probe_read_user_str_common(dst, size,
311 				(__force void __user *)unsafe_ptr);
312 	}
313 	return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr);
314 }
315 
316 static const struct bpf_func_proto bpf_probe_read_compat_str_proto = {
317 	.func		= bpf_probe_read_compat_str,
318 	.gpl_only	= true,
319 	.ret_type	= RET_INTEGER,
320 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
321 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
322 	.arg3_type	= ARG_ANYTHING,
323 };
324 #endif /* CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE */
325 
BPF_CALL_3(bpf_probe_write_user,void __user *,unsafe_ptr,const void *,src,u32,size)326 BPF_CALL_3(bpf_probe_write_user, void __user *, unsafe_ptr, const void *, src,
327 	   u32, size)
328 {
329 	/*
330 	 * Ensure we're in user context which is safe for the helper to
331 	 * run. This helper has no business in a kthread.
332 	 *
333 	 * access_ok() should prevent writing to non-user memory, but in
334 	 * some situations (nommu, temporary switch, etc) access_ok() does
335 	 * not provide enough validation, hence the check on KERNEL_DS.
336 	 *
337 	 * nmi_uaccess_okay() ensures the probe is not run in an interim
338 	 * state, when the task or mm are switched. This is specifically
339 	 * required to prevent the use of temporary mm.
340 	 */
341 
342 	if (unlikely(in_interrupt() ||
343 		     current->flags & (PF_KTHREAD | PF_EXITING)))
344 		return -EPERM;
345 	if (unlikely(!nmi_uaccess_okay()))
346 		return -EPERM;
347 
348 	return copy_to_user_nofault(unsafe_ptr, src, size);
349 }
350 
351 static const struct bpf_func_proto bpf_probe_write_user_proto = {
352 	.func		= bpf_probe_write_user,
353 	.gpl_only	= true,
354 	.ret_type	= RET_INTEGER,
355 	.arg1_type	= ARG_ANYTHING,
356 	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
357 	.arg3_type	= ARG_CONST_SIZE,
358 };
359 
bpf_get_probe_write_proto(void)360 static const struct bpf_func_proto *bpf_get_probe_write_proto(void)
361 {
362 	if (!capable(CAP_SYS_ADMIN))
363 		return NULL;
364 
365 	pr_warn_ratelimited("%s[%d] is installing a program with bpf_probe_write_user helper that may corrupt user memory!",
366 			    current->comm, task_pid_nr(current));
367 
368 	return &bpf_probe_write_user_proto;
369 }
370 
371 #define MAX_TRACE_PRINTK_VARARGS	3
372 #define BPF_TRACE_PRINTK_SIZE		1024
373 
BPF_CALL_5(bpf_trace_printk,char *,fmt,u32,fmt_size,u64,arg1,u64,arg2,u64,arg3)374 BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1,
375 	   u64, arg2, u64, arg3)
376 {
377 	u64 args[MAX_TRACE_PRINTK_VARARGS] = { arg1, arg2, arg3 };
378 	struct bpf_bprintf_data data = {
379 		.get_bin_args	= true,
380 		.get_buf	= true,
381 	};
382 	int ret;
383 
384 	ret = bpf_bprintf_prepare(fmt, fmt_size, args,
385 				  MAX_TRACE_PRINTK_VARARGS, &data);
386 	if (ret < 0)
387 		return ret;
388 
389 	ret = bstr_printf(data.buf, MAX_BPRINTF_BUF, fmt, data.bin_args);
390 
391 	trace_bpf_trace_printk(data.buf);
392 
393 	bpf_bprintf_cleanup(&data);
394 
395 	return ret;
396 }
397 
398 static const struct bpf_func_proto bpf_trace_printk_proto = {
399 	.func		= bpf_trace_printk,
400 	.gpl_only	= true,
401 	.ret_type	= RET_INTEGER,
402 	.arg1_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
403 	.arg2_type	= ARG_CONST_SIZE,
404 };
405 
__set_printk_clr_event(void)406 static void __set_printk_clr_event(void)
407 {
408 	/*
409 	 * This program might be calling bpf_trace_printk,
410 	 * so enable the associated bpf_trace/bpf_trace_printk event.
411 	 * Repeat this each time as it is possible a user has
412 	 * disabled bpf_trace_printk events.  By loading a program
413 	 * calling bpf_trace_printk() however the user has expressed
414 	 * the intent to see such events.
415 	 */
416 	if (trace_set_clr_event("bpf_trace", "bpf_trace_printk", 1))
417 		pr_warn_ratelimited("could not enable bpf_trace_printk events");
418 }
419 
bpf_get_trace_printk_proto(void)420 const struct bpf_func_proto *bpf_get_trace_printk_proto(void)
421 {
422 	__set_printk_clr_event();
423 	return &bpf_trace_printk_proto;
424 }
425 
BPF_CALL_4(bpf_trace_vprintk,char *,fmt,u32,fmt_size,const void *,args,u32,data_len)426 BPF_CALL_4(bpf_trace_vprintk, char *, fmt, u32, fmt_size, const void *, args,
427 	   u32, data_len)
428 {
429 	struct bpf_bprintf_data data = {
430 		.get_bin_args	= true,
431 		.get_buf	= true,
432 	};
433 	int ret, num_args;
434 
435 	if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 ||
436 	    (data_len && !args))
437 		return -EINVAL;
438 	num_args = data_len / 8;
439 
440 	ret = bpf_bprintf_prepare(fmt, fmt_size, args, num_args, &data);
441 	if (ret < 0)
442 		return ret;
443 
444 	ret = bstr_printf(data.buf, MAX_BPRINTF_BUF, fmt, data.bin_args);
445 
446 	trace_bpf_trace_printk(data.buf);
447 
448 	bpf_bprintf_cleanup(&data);
449 
450 	return ret;
451 }
452 
453 static const struct bpf_func_proto bpf_trace_vprintk_proto = {
454 	.func		= bpf_trace_vprintk,
455 	.gpl_only	= true,
456 	.ret_type	= RET_INTEGER,
457 	.arg1_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
458 	.arg2_type	= ARG_CONST_SIZE,
459 	.arg3_type	= ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY,
460 	.arg4_type	= ARG_CONST_SIZE_OR_ZERO,
461 };
462 
bpf_get_trace_vprintk_proto(void)463 const struct bpf_func_proto *bpf_get_trace_vprintk_proto(void)
464 {
465 	__set_printk_clr_event();
466 	return &bpf_trace_vprintk_proto;
467 }
468 
BPF_CALL_5(bpf_seq_printf,struct seq_file *,m,char *,fmt,u32,fmt_size,const void *,args,u32,data_len)469 BPF_CALL_5(bpf_seq_printf, struct seq_file *, m, char *, fmt, u32, fmt_size,
470 	   const void *, args, u32, data_len)
471 {
472 	struct bpf_bprintf_data data = {
473 		.get_bin_args	= true,
474 	};
475 	int err, num_args;
476 
477 	if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 ||
478 	    (data_len && !args))
479 		return -EINVAL;
480 	num_args = data_len / 8;
481 
482 	err = bpf_bprintf_prepare(fmt, fmt_size, args, num_args, &data);
483 	if (err < 0)
484 		return err;
485 
486 	seq_bprintf(m, fmt, data.bin_args);
487 
488 	bpf_bprintf_cleanup(&data);
489 
490 	return seq_has_overflowed(m) ? -EOVERFLOW : 0;
491 }
492 
493 BTF_ID_LIST_SINGLE(btf_seq_file_ids, struct, seq_file)
494 
495 static const struct bpf_func_proto bpf_seq_printf_proto = {
496 	.func		= bpf_seq_printf,
497 	.gpl_only	= true,
498 	.ret_type	= RET_INTEGER,
499 	.arg1_type	= ARG_PTR_TO_BTF_ID,
500 	.arg1_btf_id	= &btf_seq_file_ids[0],
501 	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
502 	.arg3_type	= ARG_CONST_SIZE,
503 	.arg4_type      = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY,
504 	.arg5_type      = ARG_CONST_SIZE_OR_ZERO,
505 };
506 
BPF_CALL_3(bpf_seq_write,struct seq_file *,m,const void *,data,u32,len)507 BPF_CALL_3(bpf_seq_write, struct seq_file *, m, const void *, data, u32, len)
508 {
509 	return seq_write(m, data, len) ? -EOVERFLOW : 0;
510 }
511 
512 static const struct bpf_func_proto bpf_seq_write_proto = {
513 	.func		= bpf_seq_write,
514 	.gpl_only	= true,
515 	.ret_type	= RET_INTEGER,
516 	.arg1_type	= ARG_PTR_TO_BTF_ID,
517 	.arg1_btf_id	= &btf_seq_file_ids[0],
518 	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
519 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
520 };
521 
BPF_CALL_4(bpf_seq_printf_btf,struct seq_file *,m,struct btf_ptr *,ptr,u32,btf_ptr_size,u64,flags)522 BPF_CALL_4(bpf_seq_printf_btf, struct seq_file *, m, struct btf_ptr *, ptr,
523 	   u32, btf_ptr_size, u64, flags)
524 {
525 	const struct btf *btf;
526 	s32 btf_id;
527 	int ret;
528 
529 	ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id);
530 	if (ret)
531 		return ret;
532 
533 	return btf_type_seq_show_flags(btf, btf_id, ptr->ptr, m, flags);
534 }
535 
536 static const struct bpf_func_proto bpf_seq_printf_btf_proto = {
537 	.func		= bpf_seq_printf_btf,
538 	.gpl_only	= true,
539 	.ret_type	= RET_INTEGER,
540 	.arg1_type	= ARG_PTR_TO_BTF_ID,
541 	.arg1_btf_id	= &btf_seq_file_ids[0],
542 	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
543 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
544 	.arg4_type	= ARG_ANYTHING,
545 };
546 
547 static __always_inline int
get_map_perf_counter(struct bpf_map * map,u64 flags,u64 * value,u64 * enabled,u64 * running)548 get_map_perf_counter(struct bpf_map *map, u64 flags,
549 		     u64 *value, u64 *enabled, u64 *running)
550 {
551 	struct bpf_array *array = container_of(map, struct bpf_array, map);
552 	unsigned int cpu = smp_processor_id();
553 	u64 index = flags & BPF_F_INDEX_MASK;
554 	struct bpf_event_entry *ee;
555 
556 	if (unlikely(flags & ~(BPF_F_INDEX_MASK)))
557 		return -EINVAL;
558 	if (index == BPF_F_CURRENT_CPU)
559 		index = cpu;
560 	if (unlikely(index >= array->map.max_entries))
561 		return -E2BIG;
562 
563 	ee = READ_ONCE(array->ptrs[index]);
564 	if (!ee)
565 		return -ENOENT;
566 
567 	return perf_event_read_local(ee->event, value, enabled, running);
568 }
569 
BPF_CALL_2(bpf_perf_event_read,struct bpf_map *,map,u64,flags)570 BPF_CALL_2(bpf_perf_event_read, struct bpf_map *, map, u64, flags)
571 {
572 	u64 value = 0;
573 	int err;
574 
575 	err = get_map_perf_counter(map, flags, &value, NULL, NULL);
576 	/*
577 	 * this api is ugly since we miss [-22..-2] range of valid
578 	 * counter values, but that's uapi
579 	 */
580 	if (err)
581 		return err;
582 	return value;
583 }
584 
585 static const struct bpf_func_proto bpf_perf_event_read_proto = {
586 	.func		= bpf_perf_event_read,
587 	.gpl_only	= true,
588 	.ret_type	= RET_INTEGER,
589 	.arg1_type	= ARG_CONST_MAP_PTR,
590 	.arg2_type	= ARG_ANYTHING,
591 };
592 
BPF_CALL_4(bpf_perf_event_read_value,struct bpf_map *,map,u64,flags,struct bpf_perf_event_value *,buf,u32,size)593 BPF_CALL_4(bpf_perf_event_read_value, struct bpf_map *, map, u64, flags,
594 	   struct bpf_perf_event_value *, buf, u32, size)
595 {
596 	int err = -EINVAL;
597 
598 	if (unlikely(size != sizeof(struct bpf_perf_event_value)))
599 		goto clear;
600 	err = get_map_perf_counter(map, flags, &buf->counter, &buf->enabled,
601 				   &buf->running);
602 	if (unlikely(err))
603 		goto clear;
604 	return 0;
605 clear:
606 	memset(buf, 0, size);
607 	return err;
608 }
609 
610 static const struct bpf_func_proto bpf_perf_event_read_value_proto = {
611 	.func		= bpf_perf_event_read_value,
612 	.gpl_only	= true,
613 	.ret_type	= RET_INTEGER,
614 	.arg1_type	= ARG_CONST_MAP_PTR,
615 	.arg2_type	= ARG_ANYTHING,
616 	.arg3_type	= ARG_PTR_TO_UNINIT_MEM,
617 	.arg4_type	= ARG_CONST_SIZE,
618 };
619 
620 static __always_inline u64
__bpf_perf_event_output(struct pt_regs * regs,struct bpf_map * map,u64 flags,struct perf_sample_data * sd)621 __bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map,
622 			u64 flags, struct perf_sample_data *sd)
623 {
624 	struct bpf_array *array = container_of(map, struct bpf_array, map);
625 	unsigned int cpu = smp_processor_id();
626 	u64 index = flags & BPF_F_INDEX_MASK;
627 	struct bpf_event_entry *ee;
628 	struct perf_event *event;
629 
630 	if (index == BPF_F_CURRENT_CPU)
631 		index = cpu;
632 	if (unlikely(index >= array->map.max_entries))
633 		return -E2BIG;
634 
635 	ee = READ_ONCE(array->ptrs[index]);
636 	if (!ee)
637 		return -ENOENT;
638 
639 	event = ee->event;
640 	if (unlikely(event->attr.type != PERF_TYPE_SOFTWARE ||
641 		     event->attr.config != PERF_COUNT_SW_BPF_OUTPUT))
642 		return -EINVAL;
643 
644 	if (unlikely(event->oncpu != cpu))
645 		return -EOPNOTSUPP;
646 
647 	return perf_event_output(event, sd, regs);
648 }
649 
650 /*
651  * Support executing tracepoints in normal, irq, and nmi context that each call
652  * bpf_perf_event_output
653  */
654 struct bpf_trace_sample_data {
655 	struct perf_sample_data sds[3];
656 };
657 
658 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_trace_sds);
659 static DEFINE_PER_CPU(int, bpf_trace_nest_level);
BPF_CALL_5(bpf_perf_event_output,struct pt_regs *,regs,struct bpf_map *,map,u64,flags,void *,data,u64,size)660 BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map,
661 	   u64, flags, void *, data, u64, size)
662 {
663 	struct bpf_trace_sample_data *sds;
664 	struct perf_raw_record raw = {
665 		.frag = {
666 			.size = size,
667 			.data = data,
668 		},
669 	};
670 	struct perf_sample_data *sd;
671 	int nest_level, err;
672 
673 	preempt_disable();
674 	sds = this_cpu_ptr(&bpf_trace_sds);
675 	nest_level = this_cpu_inc_return(bpf_trace_nest_level);
676 
677 	if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(sds->sds))) {
678 		err = -EBUSY;
679 		goto out;
680 	}
681 
682 	sd = &sds->sds[nest_level - 1];
683 
684 	if (unlikely(flags & ~(BPF_F_INDEX_MASK))) {
685 		err = -EINVAL;
686 		goto out;
687 	}
688 
689 	perf_sample_data_init(sd, 0, 0);
690 	perf_sample_save_raw_data(sd, &raw);
691 
692 	err = __bpf_perf_event_output(regs, map, flags, 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 	perf_sample_save_raw_data(sd, &raw);
752 
753 	ret = __bpf_perf_event_output(regs, map, flags, sd);
754 out:
755 	this_cpu_dec(bpf_event_output_nest_level);
756 	preempt_enable();
757 	return ret;
758 }
759 
BPF_CALL_0(bpf_get_current_task)760 BPF_CALL_0(bpf_get_current_task)
761 {
762 	return (long) current;
763 }
764 
765 const struct bpf_func_proto bpf_get_current_task_proto = {
766 	.func		= bpf_get_current_task,
767 	.gpl_only	= true,
768 	.ret_type	= RET_INTEGER,
769 };
770 
BPF_CALL_0(bpf_get_current_task_btf)771 BPF_CALL_0(bpf_get_current_task_btf)
772 {
773 	return (unsigned long) current;
774 }
775 
776 const struct bpf_func_proto bpf_get_current_task_btf_proto = {
777 	.func		= bpf_get_current_task_btf,
778 	.gpl_only	= true,
779 	.ret_type	= RET_PTR_TO_BTF_ID_TRUSTED,
780 	.ret_btf_id	= &btf_tracing_ids[BTF_TRACING_TYPE_TASK],
781 };
782 
BPF_CALL_1(bpf_task_pt_regs,struct task_struct *,task)783 BPF_CALL_1(bpf_task_pt_regs, struct task_struct *, task)
784 {
785 	return (unsigned long) task_pt_regs(task);
786 }
787 
788 BTF_ID_LIST(bpf_task_pt_regs_ids)
789 BTF_ID(struct, pt_regs)
790 
791 const struct bpf_func_proto bpf_task_pt_regs_proto = {
792 	.func		= bpf_task_pt_regs,
793 	.gpl_only	= true,
794 	.arg1_type	= ARG_PTR_TO_BTF_ID,
795 	.arg1_btf_id	= &btf_tracing_ids[BTF_TRACING_TYPE_TASK],
796 	.ret_type	= RET_PTR_TO_BTF_ID,
797 	.ret_btf_id	= &bpf_task_pt_regs_ids[0],
798 };
799 
800 struct send_signal_irq_work {
801 	struct irq_work irq_work;
802 	struct task_struct *task;
803 	u32 sig;
804 	enum pid_type type;
805 };
806 
807 static DEFINE_PER_CPU(struct send_signal_irq_work, send_signal_work);
808 
do_bpf_send_signal(struct irq_work * entry)809 static void do_bpf_send_signal(struct irq_work *entry)
810 {
811 	struct send_signal_irq_work *work;
812 
813 	work = container_of(entry, struct send_signal_irq_work, irq_work);
814 	group_send_sig_info(work->sig, SEND_SIG_PRIV, work->task, work->type);
815 	put_task_struct(work->task);
816 }
817 
bpf_send_signal_common(u32 sig,enum pid_type type)818 static int bpf_send_signal_common(u32 sig, enum pid_type type)
819 {
820 	struct send_signal_irq_work *work = NULL;
821 
822 	/* Similar to bpf_probe_write_user, task needs to be
823 	 * in a sound condition and kernel memory access be
824 	 * permitted in order to send signal to the current
825 	 * task.
826 	 */
827 	if (unlikely(current->flags & (PF_KTHREAD | PF_EXITING)))
828 		return -EPERM;
829 	if (unlikely(!nmi_uaccess_okay()))
830 		return -EPERM;
831 	/* Task should not be pid=1 to avoid kernel panic. */
832 	if (unlikely(is_global_init(current)))
833 		return -EPERM;
834 
835 	if (irqs_disabled()) {
836 		/* Do an early check on signal validity. Otherwise,
837 		 * the error is lost in deferred irq_work.
838 		 */
839 		if (unlikely(!valid_signal(sig)))
840 			return -EINVAL;
841 
842 		work = this_cpu_ptr(&send_signal_work);
843 		if (irq_work_is_busy(&work->irq_work))
844 			return -EBUSY;
845 
846 		/* Add the current task, which is the target of sending signal,
847 		 * to the irq_work. The current task may change when queued
848 		 * irq works get executed.
849 		 */
850 		work->task = get_task_struct(current);
851 		work->sig = sig;
852 		work->type = type;
853 		irq_work_queue(&work->irq_work);
854 		return 0;
855 	}
856 
857 	return group_send_sig_info(sig, SEND_SIG_PRIV, current, type);
858 }
859 
BPF_CALL_1(bpf_send_signal,u32,sig)860 BPF_CALL_1(bpf_send_signal, u32, sig)
861 {
862 	return bpf_send_signal_common(sig, PIDTYPE_TGID);
863 }
864 
865 static const struct bpf_func_proto bpf_send_signal_proto = {
866 	.func		= bpf_send_signal,
867 	.gpl_only	= false,
868 	.ret_type	= RET_INTEGER,
869 	.arg1_type	= ARG_ANYTHING,
870 };
871 
BPF_CALL_1(bpf_send_signal_thread,u32,sig)872 BPF_CALL_1(bpf_send_signal_thread, u32, sig)
873 {
874 	return bpf_send_signal_common(sig, PIDTYPE_PID);
875 }
876 
877 static const struct bpf_func_proto bpf_send_signal_thread_proto = {
878 	.func		= bpf_send_signal_thread,
879 	.gpl_only	= false,
880 	.ret_type	= RET_INTEGER,
881 	.arg1_type	= ARG_ANYTHING,
882 };
883 
BPF_CALL_3(bpf_d_path,struct path *,path,char *,buf,u32,sz)884 BPF_CALL_3(bpf_d_path, struct path *, path, char *, buf, u32, sz)
885 {
886 	struct path copy;
887 	long len;
888 	char *p;
889 
890 	if (!sz)
891 		return 0;
892 
893 	/*
894 	 * The path pointer is verified as trusted and safe to use,
895 	 * but let's double check it's valid anyway to workaround
896 	 * potentially broken verifier.
897 	 */
898 	len = copy_from_kernel_nofault(&copy, path, sizeof(*path));
899 	if (len < 0)
900 		return len;
901 
902 	p = d_path(&copy, buf, sz);
903 	if (IS_ERR(p)) {
904 		len = PTR_ERR(p);
905 	} else {
906 		len = buf + sz - p;
907 		memmove(buf, p, len);
908 	}
909 
910 	return len;
911 }
912 
913 BTF_SET_START(btf_allowlist_d_path)
914 #ifdef CONFIG_SECURITY
BTF_ID(func,security_file_permission)915 BTF_ID(func, security_file_permission)
916 BTF_ID(func, security_inode_getattr)
917 BTF_ID(func, security_file_open)
918 #endif
919 #ifdef CONFIG_SECURITY_PATH
920 BTF_ID(func, security_path_truncate)
921 #endif
922 BTF_ID(func, vfs_truncate)
923 BTF_ID(func, vfs_fallocate)
924 BTF_ID(func, dentry_open)
925 BTF_ID(func, vfs_getattr)
926 BTF_ID(func, filp_close)
927 BTF_SET_END(btf_allowlist_d_path)
928 
929 static bool bpf_d_path_allowed(const struct bpf_prog *prog)
930 {
931 	if (prog->type == BPF_PROG_TYPE_TRACING &&
932 	    prog->expected_attach_type == BPF_TRACE_ITER)
933 		return true;
934 
935 	if (prog->type == BPF_PROG_TYPE_LSM)
936 		return bpf_lsm_is_sleepable_hook(prog->aux->attach_btf_id);
937 
938 	return btf_id_set_contains(&btf_allowlist_d_path,
939 				   prog->aux->attach_btf_id);
940 }
941 
942 BTF_ID_LIST_SINGLE(bpf_d_path_btf_ids, struct, path)
943 
944 static const struct bpf_func_proto bpf_d_path_proto = {
945 	.func		= bpf_d_path,
946 	.gpl_only	= false,
947 	.ret_type	= RET_INTEGER,
948 	.arg1_type	= ARG_PTR_TO_BTF_ID,
949 	.arg1_btf_id	= &bpf_d_path_btf_ids[0],
950 	.arg2_type	= ARG_PTR_TO_MEM,
951 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
952 	.allowed	= bpf_d_path_allowed,
953 };
954 
955 #define BTF_F_ALL	(BTF_F_COMPACT  | BTF_F_NONAME | \
956 			 BTF_F_PTR_RAW | BTF_F_ZERO)
957 
bpf_btf_printf_prepare(struct btf_ptr * ptr,u32 btf_ptr_size,u64 flags,const struct btf ** btf,s32 * btf_id)958 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size,
959 				  u64 flags, const struct btf **btf,
960 				  s32 *btf_id)
961 {
962 	const struct btf_type *t;
963 
964 	if (unlikely(flags & ~(BTF_F_ALL)))
965 		return -EINVAL;
966 
967 	if (btf_ptr_size != sizeof(struct btf_ptr))
968 		return -EINVAL;
969 
970 	*btf = bpf_get_btf_vmlinux();
971 
972 	if (IS_ERR_OR_NULL(*btf))
973 		return IS_ERR(*btf) ? PTR_ERR(*btf) : -EINVAL;
974 
975 	if (ptr->type_id > 0)
976 		*btf_id = ptr->type_id;
977 	else
978 		return -EINVAL;
979 
980 	if (*btf_id > 0)
981 		t = btf_type_by_id(*btf, *btf_id);
982 	if (*btf_id <= 0 || !t)
983 		return -ENOENT;
984 
985 	return 0;
986 }
987 
BPF_CALL_5(bpf_snprintf_btf,char *,str,u32,str_size,struct btf_ptr *,ptr,u32,btf_ptr_size,u64,flags)988 BPF_CALL_5(bpf_snprintf_btf, char *, str, u32, str_size, struct btf_ptr *, ptr,
989 	   u32, btf_ptr_size, u64, flags)
990 {
991 	const struct btf *btf;
992 	s32 btf_id;
993 	int ret;
994 
995 	ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id);
996 	if (ret)
997 		return ret;
998 
999 	return btf_type_snprintf_show(btf, btf_id, ptr->ptr, str, str_size,
1000 				      flags);
1001 }
1002 
1003 const struct bpf_func_proto bpf_snprintf_btf_proto = {
1004 	.func		= bpf_snprintf_btf,
1005 	.gpl_only	= false,
1006 	.ret_type	= RET_INTEGER,
1007 	.arg1_type	= ARG_PTR_TO_MEM,
1008 	.arg2_type	= ARG_CONST_SIZE,
1009 	.arg3_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
1010 	.arg4_type	= ARG_CONST_SIZE,
1011 	.arg5_type	= ARG_ANYTHING,
1012 };
1013 
BPF_CALL_1(bpf_get_func_ip_tracing,void *,ctx)1014 BPF_CALL_1(bpf_get_func_ip_tracing, void *, ctx)
1015 {
1016 	/* This helper call is inlined by verifier. */
1017 	return ((u64 *)ctx)[-2];
1018 }
1019 
1020 static const struct bpf_func_proto bpf_get_func_ip_proto_tracing = {
1021 	.func		= bpf_get_func_ip_tracing,
1022 	.gpl_only	= true,
1023 	.ret_type	= RET_INTEGER,
1024 	.arg1_type	= ARG_PTR_TO_CTX,
1025 };
1026 
1027 #ifdef CONFIG_X86_KERNEL_IBT
get_entry_ip(unsigned long fentry_ip)1028 static unsigned long get_entry_ip(unsigned long fentry_ip)
1029 {
1030 	u32 instr;
1031 
1032 	/* We want to be extra safe in case entry ip is on the page edge,
1033 	 * but otherwise we need to avoid get_kernel_nofault()'s overhead.
1034 	 */
1035 	if ((fentry_ip & ~PAGE_MASK) < ENDBR_INSN_SIZE) {
1036 		if (get_kernel_nofault(instr, (u32 *)(fentry_ip - ENDBR_INSN_SIZE)))
1037 			return fentry_ip;
1038 	} else {
1039 		instr = *(u32 *)(fentry_ip - ENDBR_INSN_SIZE);
1040 	}
1041 	if (is_endbr(instr))
1042 		fentry_ip -= ENDBR_INSN_SIZE;
1043 	return fentry_ip;
1044 }
1045 #else
1046 #define get_entry_ip(fentry_ip) fentry_ip
1047 #endif
1048 
BPF_CALL_1(bpf_get_func_ip_kprobe,struct pt_regs *,regs)1049 BPF_CALL_1(bpf_get_func_ip_kprobe, struct pt_regs *, regs)
1050 {
1051 	struct bpf_trace_run_ctx *run_ctx __maybe_unused;
1052 	struct kprobe *kp;
1053 
1054 #ifdef CONFIG_UPROBES
1055 	run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx);
1056 	if (run_ctx->is_uprobe)
1057 		return ((struct uprobe_dispatch_data *)current->utask->vaddr)->bp_addr;
1058 #endif
1059 
1060 	kp = kprobe_running();
1061 
1062 	if (!kp || !(kp->flags & KPROBE_FLAG_ON_FUNC_ENTRY))
1063 		return 0;
1064 
1065 	return get_entry_ip((uintptr_t)kp->addr);
1066 }
1067 
1068 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe = {
1069 	.func		= bpf_get_func_ip_kprobe,
1070 	.gpl_only	= true,
1071 	.ret_type	= RET_INTEGER,
1072 	.arg1_type	= ARG_PTR_TO_CTX,
1073 };
1074 
BPF_CALL_1(bpf_get_func_ip_kprobe_multi,struct pt_regs *,regs)1075 BPF_CALL_1(bpf_get_func_ip_kprobe_multi, struct pt_regs *, regs)
1076 {
1077 	return bpf_kprobe_multi_entry_ip(current->bpf_ctx);
1078 }
1079 
1080 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe_multi = {
1081 	.func		= bpf_get_func_ip_kprobe_multi,
1082 	.gpl_only	= false,
1083 	.ret_type	= RET_INTEGER,
1084 	.arg1_type	= ARG_PTR_TO_CTX,
1085 };
1086 
BPF_CALL_1(bpf_get_attach_cookie_kprobe_multi,struct pt_regs *,regs)1087 BPF_CALL_1(bpf_get_attach_cookie_kprobe_multi, struct pt_regs *, regs)
1088 {
1089 	return bpf_kprobe_multi_cookie(current->bpf_ctx);
1090 }
1091 
1092 static const struct bpf_func_proto bpf_get_attach_cookie_proto_kmulti = {
1093 	.func		= bpf_get_attach_cookie_kprobe_multi,
1094 	.gpl_only	= false,
1095 	.ret_type	= RET_INTEGER,
1096 	.arg1_type	= ARG_PTR_TO_CTX,
1097 };
1098 
BPF_CALL_1(bpf_get_func_ip_uprobe_multi,struct pt_regs *,regs)1099 BPF_CALL_1(bpf_get_func_ip_uprobe_multi, struct pt_regs *, regs)
1100 {
1101 	return bpf_uprobe_multi_entry_ip(current->bpf_ctx);
1102 }
1103 
1104 static const struct bpf_func_proto bpf_get_func_ip_proto_uprobe_multi = {
1105 	.func		= bpf_get_func_ip_uprobe_multi,
1106 	.gpl_only	= false,
1107 	.ret_type	= RET_INTEGER,
1108 	.arg1_type	= ARG_PTR_TO_CTX,
1109 };
1110 
BPF_CALL_1(bpf_get_attach_cookie_uprobe_multi,struct pt_regs *,regs)1111 BPF_CALL_1(bpf_get_attach_cookie_uprobe_multi, struct pt_regs *, regs)
1112 {
1113 	return bpf_uprobe_multi_cookie(current->bpf_ctx);
1114 }
1115 
1116 static const struct bpf_func_proto bpf_get_attach_cookie_proto_umulti = {
1117 	.func		= bpf_get_attach_cookie_uprobe_multi,
1118 	.gpl_only	= false,
1119 	.ret_type	= RET_INTEGER,
1120 	.arg1_type	= ARG_PTR_TO_CTX,
1121 };
1122 
BPF_CALL_1(bpf_get_attach_cookie_trace,void *,ctx)1123 BPF_CALL_1(bpf_get_attach_cookie_trace, void *, ctx)
1124 {
1125 	struct bpf_trace_run_ctx *run_ctx;
1126 
1127 	run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx);
1128 	return run_ctx->bpf_cookie;
1129 }
1130 
1131 static const struct bpf_func_proto bpf_get_attach_cookie_proto_trace = {
1132 	.func		= bpf_get_attach_cookie_trace,
1133 	.gpl_only	= false,
1134 	.ret_type	= RET_INTEGER,
1135 	.arg1_type	= ARG_PTR_TO_CTX,
1136 };
1137 
BPF_CALL_1(bpf_get_attach_cookie_pe,struct bpf_perf_event_data_kern *,ctx)1138 BPF_CALL_1(bpf_get_attach_cookie_pe, struct bpf_perf_event_data_kern *, ctx)
1139 {
1140 	return ctx->event->bpf_cookie;
1141 }
1142 
1143 static const struct bpf_func_proto bpf_get_attach_cookie_proto_pe = {
1144 	.func		= bpf_get_attach_cookie_pe,
1145 	.gpl_only	= false,
1146 	.ret_type	= RET_INTEGER,
1147 	.arg1_type	= ARG_PTR_TO_CTX,
1148 };
1149 
BPF_CALL_1(bpf_get_attach_cookie_tracing,void *,ctx)1150 BPF_CALL_1(bpf_get_attach_cookie_tracing, void *, ctx)
1151 {
1152 	struct bpf_trace_run_ctx *run_ctx;
1153 
1154 	run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx);
1155 	return run_ctx->bpf_cookie;
1156 }
1157 
1158 static const struct bpf_func_proto bpf_get_attach_cookie_proto_tracing = {
1159 	.func		= bpf_get_attach_cookie_tracing,
1160 	.gpl_only	= false,
1161 	.ret_type	= RET_INTEGER,
1162 	.arg1_type	= ARG_PTR_TO_CTX,
1163 };
1164 
BPF_CALL_3(bpf_get_branch_snapshot,void *,buf,u32,size,u64,flags)1165 BPF_CALL_3(bpf_get_branch_snapshot, void *, buf, u32, size, u64, flags)
1166 {
1167 	static const u32 br_entry_size = sizeof(struct perf_branch_entry);
1168 	u32 entry_cnt = size / br_entry_size;
1169 
1170 	entry_cnt = static_call(perf_snapshot_branch_stack)(buf, entry_cnt);
1171 
1172 	if (unlikely(flags))
1173 		return -EINVAL;
1174 
1175 	if (!entry_cnt)
1176 		return -ENOENT;
1177 
1178 	return entry_cnt * br_entry_size;
1179 }
1180 
1181 static const struct bpf_func_proto bpf_get_branch_snapshot_proto = {
1182 	.func		= bpf_get_branch_snapshot,
1183 	.gpl_only	= true,
1184 	.ret_type	= RET_INTEGER,
1185 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
1186 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
1187 };
1188 
BPF_CALL_3(get_func_arg,void *,ctx,u32,n,u64 *,value)1189 BPF_CALL_3(get_func_arg, void *, ctx, u32, n, u64 *, value)
1190 {
1191 	/* This helper call is inlined by verifier. */
1192 	u64 nr_args = ((u64 *)ctx)[-1];
1193 
1194 	if ((u64) n >= nr_args)
1195 		return -EINVAL;
1196 	*value = ((u64 *)ctx)[n];
1197 	return 0;
1198 }
1199 
1200 static const struct bpf_func_proto bpf_get_func_arg_proto = {
1201 	.func		= get_func_arg,
1202 	.ret_type	= RET_INTEGER,
1203 	.arg1_type	= ARG_PTR_TO_CTX,
1204 	.arg2_type	= ARG_ANYTHING,
1205 	.arg3_type	= ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED,
1206 	.arg3_size	= sizeof(u64),
1207 };
1208 
BPF_CALL_2(get_func_ret,void *,ctx,u64 *,value)1209 BPF_CALL_2(get_func_ret, void *, ctx, u64 *, value)
1210 {
1211 	/* This helper call is inlined by verifier. */
1212 	u64 nr_args = ((u64 *)ctx)[-1];
1213 
1214 	*value = ((u64 *)ctx)[nr_args];
1215 	return 0;
1216 }
1217 
1218 static const struct bpf_func_proto bpf_get_func_ret_proto = {
1219 	.func		= get_func_ret,
1220 	.ret_type	= RET_INTEGER,
1221 	.arg1_type	= ARG_PTR_TO_CTX,
1222 	.arg2_type	= ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED,
1223 	.arg2_size	= sizeof(u64),
1224 };
1225 
BPF_CALL_1(get_func_arg_cnt,void *,ctx)1226 BPF_CALL_1(get_func_arg_cnt, void *, ctx)
1227 {
1228 	/* This helper call is inlined by verifier. */
1229 	return ((u64 *)ctx)[-1];
1230 }
1231 
1232 static const struct bpf_func_proto bpf_get_func_arg_cnt_proto = {
1233 	.func		= get_func_arg_cnt,
1234 	.ret_type	= RET_INTEGER,
1235 	.arg1_type	= ARG_PTR_TO_CTX,
1236 };
1237 
1238 #ifdef CONFIG_KEYS
1239 __bpf_kfunc_start_defs();
1240 
1241 /**
1242  * bpf_lookup_user_key - lookup a key by its serial
1243  * @serial: key handle serial number
1244  * @flags: lookup-specific flags
1245  *
1246  * Search a key with a given *serial* and the provided *flags*.
1247  * If found, increment the reference count of the key by one, and
1248  * return it in the bpf_key structure.
1249  *
1250  * The bpf_key structure must be passed to bpf_key_put() when done
1251  * with it, so that the key reference count is decremented and the
1252  * bpf_key structure is freed.
1253  *
1254  * Permission checks are deferred to the time the key is used by
1255  * one of the available key-specific kfuncs.
1256  *
1257  * Set *flags* with KEY_LOOKUP_CREATE, to attempt creating a requested
1258  * special keyring (e.g. session keyring), if it doesn't yet exist.
1259  * Set *flags* with KEY_LOOKUP_PARTIAL, to lookup a key without waiting
1260  * for the key construction, and to retrieve uninstantiated keys (keys
1261  * without data attached to them).
1262  *
1263  * Return: a bpf_key pointer with a valid key pointer if the key is found, a
1264  *         NULL pointer otherwise.
1265  */
bpf_lookup_user_key(u32 serial,u64 flags)1266 __bpf_kfunc struct bpf_key *bpf_lookup_user_key(u32 serial, u64 flags)
1267 {
1268 	key_ref_t key_ref;
1269 	struct bpf_key *bkey;
1270 
1271 	if (flags & ~KEY_LOOKUP_ALL)
1272 		return NULL;
1273 
1274 	/*
1275 	 * Permission check is deferred until the key is used, as the
1276 	 * intent of the caller is unknown here.
1277 	 */
1278 	key_ref = lookup_user_key(serial, flags, KEY_DEFER_PERM_CHECK);
1279 	if (IS_ERR(key_ref))
1280 		return NULL;
1281 
1282 	bkey = kmalloc(sizeof(*bkey), GFP_KERNEL);
1283 	if (!bkey) {
1284 		key_put(key_ref_to_ptr(key_ref));
1285 		return NULL;
1286 	}
1287 
1288 	bkey->key = key_ref_to_ptr(key_ref);
1289 	bkey->has_ref = true;
1290 
1291 	return bkey;
1292 }
1293 
1294 /**
1295  * bpf_lookup_system_key - lookup a key by a system-defined ID
1296  * @id: key ID
1297  *
1298  * Obtain a bpf_key structure with a key pointer set to the passed key ID.
1299  * The key pointer is marked as invalid, to prevent bpf_key_put() from
1300  * attempting to decrement the key reference count on that pointer. The key
1301  * pointer set in such way is currently understood only by
1302  * verify_pkcs7_signature().
1303  *
1304  * Set *id* to one of the values defined in include/linux/verification.h:
1305  * 0 for the primary keyring (immutable keyring of system keys);
1306  * VERIFY_USE_SECONDARY_KEYRING for both the primary and secondary keyring
1307  * (where keys can be added only if they are vouched for by existing keys
1308  * in those keyrings); VERIFY_USE_PLATFORM_KEYRING for the platform
1309  * keyring (primarily used by the integrity subsystem to verify a kexec'ed
1310  * kerned image and, possibly, the initramfs signature).
1311  *
1312  * Return: a bpf_key pointer with an invalid key pointer set from the
1313  *         pre-determined ID on success, a NULL pointer otherwise
1314  */
bpf_lookup_system_key(u64 id)1315 __bpf_kfunc struct bpf_key *bpf_lookup_system_key(u64 id)
1316 {
1317 	struct bpf_key *bkey;
1318 
1319 	if (system_keyring_id_check(id) < 0)
1320 		return NULL;
1321 
1322 	bkey = kmalloc(sizeof(*bkey), GFP_ATOMIC);
1323 	if (!bkey)
1324 		return NULL;
1325 
1326 	bkey->key = (struct key *)(unsigned long)id;
1327 	bkey->has_ref = false;
1328 
1329 	return bkey;
1330 }
1331 
1332 /**
1333  * bpf_key_put - decrement key reference count if key is valid and free bpf_key
1334  * @bkey: bpf_key structure
1335  *
1336  * Decrement the reference count of the key inside *bkey*, if the pointer
1337  * is valid, and free *bkey*.
1338  */
bpf_key_put(struct bpf_key * bkey)1339 __bpf_kfunc void bpf_key_put(struct bpf_key *bkey)
1340 {
1341 	if (bkey->has_ref)
1342 		key_put(bkey->key);
1343 
1344 	kfree(bkey);
1345 }
1346 
1347 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION
1348 /**
1349  * bpf_verify_pkcs7_signature - verify a PKCS#7 signature
1350  * @data_p: data to verify
1351  * @sig_p: signature of the data
1352  * @trusted_keyring: keyring with keys trusted for signature verification
1353  *
1354  * Verify the PKCS#7 signature *sig_ptr* against the supplied *data_ptr*
1355  * with keys in a keyring referenced by *trusted_keyring*.
1356  *
1357  * Return: 0 on success, a negative value on error.
1358  */
bpf_verify_pkcs7_signature(struct bpf_dynptr * data_p,struct bpf_dynptr * sig_p,struct bpf_key * trusted_keyring)1359 __bpf_kfunc int bpf_verify_pkcs7_signature(struct bpf_dynptr *data_p,
1360 			       struct bpf_dynptr *sig_p,
1361 			       struct bpf_key *trusted_keyring)
1362 {
1363 	struct bpf_dynptr_kern *data_ptr = (struct bpf_dynptr_kern *)data_p;
1364 	struct bpf_dynptr_kern *sig_ptr = (struct bpf_dynptr_kern *)sig_p;
1365 	const void *data, *sig;
1366 	u32 data_len, sig_len;
1367 	int ret;
1368 
1369 	if (trusted_keyring->has_ref) {
1370 		/*
1371 		 * Do the permission check deferred in bpf_lookup_user_key().
1372 		 * See bpf_lookup_user_key() for more details.
1373 		 *
1374 		 * A call to key_task_permission() here would be redundant, as
1375 		 * it is already done by keyring_search() called by
1376 		 * find_asymmetric_key().
1377 		 */
1378 		ret = key_validate(trusted_keyring->key);
1379 		if (ret < 0)
1380 			return ret;
1381 	}
1382 
1383 	data_len = __bpf_dynptr_size(data_ptr);
1384 	data = __bpf_dynptr_data(data_ptr, data_len);
1385 	sig_len = __bpf_dynptr_size(sig_ptr);
1386 	sig = __bpf_dynptr_data(sig_ptr, sig_len);
1387 
1388 	return verify_pkcs7_signature(data, data_len, sig, sig_len,
1389 				      trusted_keyring->key,
1390 				      VERIFYING_UNSPECIFIED_SIGNATURE, NULL,
1391 				      NULL);
1392 }
1393 #endif /* CONFIG_SYSTEM_DATA_VERIFICATION */
1394 
1395 __bpf_kfunc_end_defs();
1396 
1397 BTF_KFUNCS_START(key_sig_kfunc_set)
1398 BTF_ID_FLAGS(func, bpf_lookup_user_key, KF_ACQUIRE | KF_RET_NULL | KF_SLEEPABLE)
1399 BTF_ID_FLAGS(func, bpf_lookup_system_key, KF_ACQUIRE | KF_RET_NULL)
1400 BTF_ID_FLAGS(func, bpf_key_put, KF_RELEASE)
1401 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION
1402 BTF_ID_FLAGS(func, bpf_verify_pkcs7_signature, KF_SLEEPABLE)
1403 #endif
1404 BTF_KFUNCS_END(key_sig_kfunc_set)
1405 
1406 static const struct btf_kfunc_id_set bpf_key_sig_kfunc_set = {
1407 	.owner = THIS_MODULE,
1408 	.set = &key_sig_kfunc_set,
1409 };
1410 
bpf_key_sig_kfuncs_init(void)1411 static int __init bpf_key_sig_kfuncs_init(void)
1412 {
1413 	return register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING,
1414 					 &bpf_key_sig_kfunc_set);
1415 }
1416 
1417 late_initcall(bpf_key_sig_kfuncs_init);
1418 #endif /* CONFIG_KEYS */
1419 
1420 static const struct bpf_func_proto *
bpf_tracing_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1421 bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1422 {
1423 	switch (func_id) {
1424 	case BPF_FUNC_map_lookup_elem:
1425 		return &bpf_map_lookup_elem_proto;
1426 	case BPF_FUNC_map_update_elem:
1427 		return &bpf_map_update_elem_proto;
1428 	case BPF_FUNC_map_delete_elem:
1429 		return &bpf_map_delete_elem_proto;
1430 	case BPF_FUNC_map_push_elem:
1431 		return &bpf_map_push_elem_proto;
1432 	case BPF_FUNC_map_pop_elem:
1433 		return &bpf_map_pop_elem_proto;
1434 	case BPF_FUNC_map_peek_elem:
1435 		return &bpf_map_peek_elem_proto;
1436 	case BPF_FUNC_map_lookup_percpu_elem:
1437 		return &bpf_map_lookup_percpu_elem_proto;
1438 	case BPF_FUNC_ktime_get_ns:
1439 		return &bpf_ktime_get_ns_proto;
1440 	case BPF_FUNC_ktime_get_boot_ns:
1441 		return &bpf_ktime_get_boot_ns_proto;
1442 	case BPF_FUNC_tail_call:
1443 		return &bpf_tail_call_proto;
1444 	case BPF_FUNC_get_current_task:
1445 		return &bpf_get_current_task_proto;
1446 	case BPF_FUNC_get_current_task_btf:
1447 		return &bpf_get_current_task_btf_proto;
1448 	case BPF_FUNC_task_pt_regs:
1449 		return &bpf_task_pt_regs_proto;
1450 	case BPF_FUNC_get_current_uid_gid:
1451 		return &bpf_get_current_uid_gid_proto;
1452 	case BPF_FUNC_get_current_comm:
1453 		return &bpf_get_current_comm_proto;
1454 	case BPF_FUNC_trace_printk:
1455 		return bpf_get_trace_printk_proto();
1456 	case BPF_FUNC_get_smp_processor_id:
1457 		return &bpf_get_smp_processor_id_proto;
1458 	case BPF_FUNC_get_numa_node_id:
1459 		return &bpf_get_numa_node_id_proto;
1460 	case BPF_FUNC_perf_event_read:
1461 		return &bpf_perf_event_read_proto;
1462 	case BPF_FUNC_get_prandom_u32:
1463 		return &bpf_get_prandom_u32_proto;
1464 	case BPF_FUNC_probe_write_user:
1465 		return security_locked_down(LOCKDOWN_BPF_WRITE_USER) < 0 ?
1466 		       NULL : bpf_get_probe_write_proto();
1467 	case BPF_FUNC_probe_read_user:
1468 		return &bpf_probe_read_user_proto;
1469 	case BPF_FUNC_probe_read_kernel:
1470 		return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
1471 		       NULL : &bpf_probe_read_kernel_proto;
1472 	case BPF_FUNC_probe_read_user_str:
1473 		return &bpf_probe_read_user_str_proto;
1474 	case BPF_FUNC_probe_read_kernel_str:
1475 		return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
1476 		       NULL : &bpf_probe_read_kernel_str_proto;
1477 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
1478 	case BPF_FUNC_probe_read:
1479 		return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
1480 		       NULL : &bpf_probe_read_compat_proto;
1481 	case BPF_FUNC_probe_read_str:
1482 		return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
1483 		       NULL : &bpf_probe_read_compat_str_proto;
1484 #endif
1485 #ifdef CONFIG_CGROUPS
1486 	case BPF_FUNC_cgrp_storage_get:
1487 		return &bpf_cgrp_storage_get_proto;
1488 	case BPF_FUNC_cgrp_storage_delete:
1489 		return &bpf_cgrp_storage_delete_proto;
1490 	case BPF_FUNC_current_task_under_cgroup:
1491 		return &bpf_current_task_under_cgroup_proto;
1492 #endif
1493 	case BPF_FUNC_send_signal:
1494 		return &bpf_send_signal_proto;
1495 	case BPF_FUNC_send_signal_thread:
1496 		return &bpf_send_signal_thread_proto;
1497 	case BPF_FUNC_perf_event_read_value:
1498 		return &bpf_perf_event_read_value_proto;
1499 	case BPF_FUNC_ringbuf_output:
1500 		return &bpf_ringbuf_output_proto;
1501 	case BPF_FUNC_ringbuf_reserve:
1502 		return &bpf_ringbuf_reserve_proto;
1503 	case BPF_FUNC_ringbuf_submit:
1504 		return &bpf_ringbuf_submit_proto;
1505 	case BPF_FUNC_ringbuf_discard:
1506 		return &bpf_ringbuf_discard_proto;
1507 	case BPF_FUNC_ringbuf_query:
1508 		return &bpf_ringbuf_query_proto;
1509 	case BPF_FUNC_jiffies64:
1510 		return &bpf_jiffies64_proto;
1511 	case BPF_FUNC_get_task_stack:
1512 		return prog->sleepable ? &bpf_get_task_stack_sleepable_proto
1513 				       : &bpf_get_task_stack_proto;
1514 	case BPF_FUNC_copy_from_user:
1515 		return &bpf_copy_from_user_proto;
1516 	case BPF_FUNC_copy_from_user_task:
1517 		return &bpf_copy_from_user_task_proto;
1518 	case BPF_FUNC_snprintf_btf:
1519 		return &bpf_snprintf_btf_proto;
1520 	case BPF_FUNC_per_cpu_ptr:
1521 		return &bpf_per_cpu_ptr_proto;
1522 	case BPF_FUNC_this_cpu_ptr:
1523 		return &bpf_this_cpu_ptr_proto;
1524 	case BPF_FUNC_task_storage_get:
1525 		if (bpf_prog_check_recur(prog))
1526 			return &bpf_task_storage_get_recur_proto;
1527 		return &bpf_task_storage_get_proto;
1528 	case BPF_FUNC_task_storage_delete:
1529 		if (bpf_prog_check_recur(prog))
1530 			return &bpf_task_storage_delete_recur_proto;
1531 		return &bpf_task_storage_delete_proto;
1532 	case BPF_FUNC_for_each_map_elem:
1533 		return &bpf_for_each_map_elem_proto;
1534 	case BPF_FUNC_snprintf:
1535 		return &bpf_snprintf_proto;
1536 	case BPF_FUNC_get_func_ip:
1537 		return &bpf_get_func_ip_proto_tracing;
1538 	case BPF_FUNC_get_branch_snapshot:
1539 		return &bpf_get_branch_snapshot_proto;
1540 	case BPF_FUNC_find_vma:
1541 		return &bpf_find_vma_proto;
1542 	case BPF_FUNC_trace_vprintk:
1543 		return bpf_get_trace_vprintk_proto();
1544 	default:
1545 		return bpf_base_func_proto(func_id, prog);
1546 	}
1547 }
1548 
is_kprobe_multi(const struct bpf_prog * prog)1549 static bool is_kprobe_multi(const struct bpf_prog *prog)
1550 {
1551 	return prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI ||
1552 	       prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION;
1553 }
1554 
is_kprobe_session(const struct bpf_prog * prog)1555 static inline bool is_kprobe_session(const struct bpf_prog *prog)
1556 {
1557 	return prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION;
1558 }
1559 
1560 static const struct bpf_func_proto *
kprobe_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1561 kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1562 {
1563 	switch (func_id) {
1564 	case BPF_FUNC_perf_event_output:
1565 		return &bpf_perf_event_output_proto;
1566 	case BPF_FUNC_get_stackid:
1567 		return &bpf_get_stackid_proto;
1568 	case BPF_FUNC_get_stack:
1569 		return prog->sleepable ? &bpf_get_stack_sleepable_proto : &bpf_get_stack_proto;
1570 #ifdef CONFIG_BPF_KPROBE_OVERRIDE
1571 	case BPF_FUNC_override_return:
1572 		return &bpf_override_return_proto;
1573 #endif
1574 	case BPF_FUNC_get_func_ip:
1575 		if (is_kprobe_multi(prog))
1576 			return &bpf_get_func_ip_proto_kprobe_multi;
1577 		if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI)
1578 			return &bpf_get_func_ip_proto_uprobe_multi;
1579 		return &bpf_get_func_ip_proto_kprobe;
1580 	case BPF_FUNC_get_attach_cookie:
1581 		if (is_kprobe_multi(prog))
1582 			return &bpf_get_attach_cookie_proto_kmulti;
1583 		if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI)
1584 			return &bpf_get_attach_cookie_proto_umulti;
1585 		return &bpf_get_attach_cookie_proto_trace;
1586 	default:
1587 		return bpf_tracing_func_proto(func_id, prog);
1588 	}
1589 }
1590 
1591 /* 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)1592 static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
1593 					const struct bpf_prog *prog,
1594 					struct bpf_insn_access_aux *info)
1595 {
1596 	if (off < 0 || off >= sizeof(struct pt_regs))
1597 		return false;
1598 	if (type != BPF_READ)
1599 		return false;
1600 	if (off % size != 0)
1601 		return false;
1602 	/*
1603 	 * Assertion for 32 bit to make sure last 8 byte access
1604 	 * (BPF_DW) to the last 4 byte member is disallowed.
1605 	 */
1606 	if (off + size > sizeof(struct pt_regs))
1607 		return false;
1608 
1609 	return true;
1610 }
1611 
1612 const struct bpf_verifier_ops kprobe_verifier_ops = {
1613 	.get_func_proto  = kprobe_prog_func_proto,
1614 	.is_valid_access = kprobe_prog_is_valid_access,
1615 };
1616 
1617 const struct bpf_prog_ops kprobe_prog_ops = {
1618 };
1619 
BPF_CALL_5(bpf_perf_event_output_tp,void *,tp_buff,struct bpf_map *,map,u64,flags,void *,data,u64,size)1620 BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map,
1621 	   u64, flags, void *, data, u64, size)
1622 {
1623 	struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1624 
1625 	/*
1626 	 * r1 points to perf tracepoint buffer where first 8 bytes are hidden
1627 	 * from bpf program and contain a pointer to 'struct pt_regs'. Fetch it
1628 	 * from there and call the same bpf_perf_event_output() helper inline.
1629 	 */
1630 	return ____bpf_perf_event_output(regs, map, flags, data, size);
1631 }
1632 
1633 static const struct bpf_func_proto bpf_perf_event_output_proto_tp = {
1634 	.func		= bpf_perf_event_output_tp,
1635 	.gpl_only	= true,
1636 	.ret_type	= RET_INTEGER,
1637 	.arg1_type	= ARG_PTR_TO_CTX,
1638 	.arg2_type	= ARG_CONST_MAP_PTR,
1639 	.arg3_type	= ARG_ANYTHING,
1640 	.arg4_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
1641 	.arg5_type	= ARG_CONST_SIZE_OR_ZERO,
1642 };
1643 
BPF_CALL_3(bpf_get_stackid_tp,void *,tp_buff,struct bpf_map *,map,u64,flags)1644 BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map,
1645 	   u64, flags)
1646 {
1647 	struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1648 
1649 	/*
1650 	 * Same comment as in bpf_perf_event_output_tp(), only that this time
1651 	 * the other helper's function body cannot be inlined due to being
1652 	 * external, thus we need to call raw helper function.
1653 	 */
1654 	return bpf_get_stackid((unsigned long) regs, (unsigned long) map,
1655 			       flags, 0, 0);
1656 }
1657 
1658 static const struct bpf_func_proto bpf_get_stackid_proto_tp = {
1659 	.func		= bpf_get_stackid_tp,
1660 	.gpl_only	= true,
1661 	.ret_type	= RET_INTEGER,
1662 	.arg1_type	= ARG_PTR_TO_CTX,
1663 	.arg2_type	= ARG_CONST_MAP_PTR,
1664 	.arg3_type	= ARG_ANYTHING,
1665 };
1666 
BPF_CALL_4(bpf_get_stack_tp,void *,tp_buff,void *,buf,u32,size,u64,flags)1667 BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size,
1668 	   u64, flags)
1669 {
1670 	struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1671 
1672 	return bpf_get_stack((unsigned long) regs, (unsigned long) buf,
1673 			     (unsigned long) size, flags, 0);
1674 }
1675 
1676 static const struct bpf_func_proto bpf_get_stack_proto_tp = {
1677 	.func		= bpf_get_stack_tp,
1678 	.gpl_only	= true,
1679 	.ret_type	= RET_INTEGER,
1680 	.arg1_type	= ARG_PTR_TO_CTX,
1681 	.arg2_type	= ARG_PTR_TO_UNINIT_MEM,
1682 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
1683 	.arg4_type	= ARG_ANYTHING,
1684 };
1685 
1686 static const struct bpf_func_proto *
tp_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1687 tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1688 {
1689 	switch (func_id) {
1690 	case BPF_FUNC_perf_event_output:
1691 		return &bpf_perf_event_output_proto_tp;
1692 	case BPF_FUNC_get_stackid:
1693 		return &bpf_get_stackid_proto_tp;
1694 	case BPF_FUNC_get_stack:
1695 		return &bpf_get_stack_proto_tp;
1696 	case BPF_FUNC_get_attach_cookie:
1697 		return &bpf_get_attach_cookie_proto_trace;
1698 	default:
1699 		return bpf_tracing_func_proto(func_id, prog);
1700 	}
1701 }
1702 
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)1703 static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type,
1704 				    const struct bpf_prog *prog,
1705 				    struct bpf_insn_access_aux *info)
1706 {
1707 	if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE)
1708 		return false;
1709 	if (type != BPF_READ)
1710 		return false;
1711 	if (off % size != 0)
1712 		return false;
1713 
1714 	BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(__u64));
1715 	return true;
1716 }
1717 
1718 const struct bpf_verifier_ops tracepoint_verifier_ops = {
1719 	.get_func_proto  = tp_prog_func_proto,
1720 	.is_valid_access = tp_prog_is_valid_access,
1721 };
1722 
1723 const struct bpf_prog_ops tracepoint_prog_ops = {
1724 };
1725 
BPF_CALL_3(bpf_perf_prog_read_value,struct bpf_perf_event_data_kern *,ctx,struct bpf_perf_event_value *,buf,u32,size)1726 BPF_CALL_3(bpf_perf_prog_read_value, struct bpf_perf_event_data_kern *, ctx,
1727 	   struct bpf_perf_event_value *, buf, u32, size)
1728 {
1729 	int err = -EINVAL;
1730 
1731 	if (unlikely(size != sizeof(struct bpf_perf_event_value)))
1732 		goto clear;
1733 	err = perf_event_read_local(ctx->event, &buf->counter, &buf->enabled,
1734 				    &buf->running);
1735 	if (unlikely(err))
1736 		goto clear;
1737 	return 0;
1738 clear:
1739 	memset(buf, 0, size);
1740 	return err;
1741 }
1742 
1743 static const struct bpf_func_proto bpf_perf_prog_read_value_proto = {
1744          .func           = bpf_perf_prog_read_value,
1745          .gpl_only       = true,
1746          .ret_type       = RET_INTEGER,
1747          .arg1_type      = ARG_PTR_TO_CTX,
1748          .arg2_type      = ARG_PTR_TO_UNINIT_MEM,
1749          .arg3_type      = ARG_CONST_SIZE,
1750 };
1751 
BPF_CALL_4(bpf_read_branch_records,struct bpf_perf_event_data_kern *,ctx,void *,buf,u32,size,u64,flags)1752 BPF_CALL_4(bpf_read_branch_records, struct bpf_perf_event_data_kern *, ctx,
1753 	   void *, buf, u32, size, u64, flags)
1754 {
1755 	static const u32 br_entry_size = sizeof(struct perf_branch_entry);
1756 	struct perf_branch_stack *br_stack = ctx->data->br_stack;
1757 	u32 to_copy;
1758 
1759 	if (unlikely(flags & ~BPF_F_GET_BRANCH_RECORDS_SIZE))
1760 		return -EINVAL;
1761 
1762 	if (unlikely(!(ctx->data->sample_flags & PERF_SAMPLE_BRANCH_STACK)))
1763 		return -ENOENT;
1764 
1765 	if (unlikely(!br_stack))
1766 		return -ENOENT;
1767 
1768 	if (flags & BPF_F_GET_BRANCH_RECORDS_SIZE)
1769 		return br_stack->nr * br_entry_size;
1770 
1771 	if (!buf || (size % br_entry_size != 0))
1772 		return -EINVAL;
1773 
1774 	to_copy = min_t(u32, br_stack->nr * br_entry_size, size);
1775 	memcpy(buf, br_stack->entries, to_copy);
1776 
1777 	return to_copy;
1778 }
1779 
1780 static const struct bpf_func_proto bpf_read_branch_records_proto = {
1781 	.func           = bpf_read_branch_records,
1782 	.gpl_only       = true,
1783 	.ret_type       = RET_INTEGER,
1784 	.arg1_type      = ARG_PTR_TO_CTX,
1785 	.arg2_type      = ARG_PTR_TO_MEM_OR_NULL,
1786 	.arg3_type      = ARG_CONST_SIZE_OR_ZERO,
1787 	.arg4_type      = ARG_ANYTHING,
1788 };
1789 
1790 static const struct bpf_func_proto *
pe_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1791 pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1792 {
1793 	switch (func_id) {
1794 	case BPF_FUNC_perf_event_output:
1795 		return &bpf_perf_event_output_proto_tp;
1796 	case BPF_FUNC_get_stackid:
1797 		return &bpf_get_stackid_proto_pe;
1798 	case BPF_FUNC_get_stack:
1799 		return &bpf_get_stack_proto_pe;
1800 	case BPF_FUNC_perf_prog_read_value:
1801 		return &bpf_perf_prog_read_value_proto;
1802 	case BPF_FUNC_read_branch_records:
1803 		return &bpf_read_branch_records_proto;
1804 	case BPF_FUNC_get_attach_cookie:
1805 		return &bpf_get_attach_cookie_proto_pe;
1806 	default:
1807 		return bpf_tracing_func_proto(func_id, prog);
1808 	}
1809 }
1810 
1811 /*
1812  * bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp
1813  * to avoid potential recursive reuse issue when/if tracepoints are added
1814  * inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack.
1815  *
1816  * Since raw tracepoints run despite bpf_prog_active, support concurrent usage
1817  * in normal, irq, and nmi context.
1818  */
1819 struct bpf_raw_tp_regs {
1820 	struct pt_regs regs[3];
1821 };
1822 static DEFINE_PER_CPU(struct bpf_raw_tp_regs, bpf_raw_tp_regs);
1823 static DEFINE_PER_CPU(int, bpf_raw_tp_nest_level);
get_bpf_raw_tp_regs(void)1824 static struct pt_regs *get_bpf_raw_tp_regs(void)
1825 {
1826 	struct bpf_raw_tp_regs *tp_regs = this_cpu_ptr(&bpf_raw_tp_regs);
1827 	int nest_level = this_cpu_inc_return(bpf_raw_tp_nest_level);
1828 
1829 	if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(tp_regs->regs))) {
1830 		this_cpu_dec(bpf_raw_tp_nest_level);
1831 		return ERR_PTR(-EBUSY);
1832 	}
1833 
1834 	return &tp_regs->regs[nest_level - 1];
1835 }
1836 
put_bpf_raw_tp_regs(void)1837 static void put_bpf_raw_tp_regs(void)
1838 {
1839 	this_cpu_dec(bpf_raw_tp_nest_level);
1840 }
1841 
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)1842 BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args,
1843 	   struct bpf_map *, map, u64, flags, void *, data, u64, size)
1844 {
1845 	struct pt_regs *regs = get_bpf_raw_tp_regs();
1846 	int ret;
1847 
1848 	if (IS_ERR(regs))
1849 		return PTR_ERR(regs);
1850 
1851 	perf_fetch_caller_regs(regs);
1852 	ret = ____bpf_perf_event_output(regs, map, flags, data, size);
1853 
1854 	put_bpf_raw_tp_regs();
1855 	return ret;
1856 }
1857 
1858 static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = {
1859 	.func		= bpf_perf_event_output_raw_tp,
1860 	.gpl_only	= true,
1861 	.ret_type	= RET_INTEGER,
1862 	.arg1_type	= ARG_PTR_TO_CTX,
1863 	.arg2_type	= ARG_CONST_MAP_PTR,
1864 	.arg3_type	= ARG_ANYTHING,
1865 	.arg4_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
1866 	.arg5_type	= ARG_CONST_SIZE_OR_ZERO,
1867 };
1868 
1869 extern const struct bpf_func_proto bpf_skb_output_proto;
1870 extern const struct bpf_func_proto bpf_xdp_output_proto;
1871 extern const struct bpf_func_proto bpf_xdp_get_buff_len_trace_proto;
1872 
BPF_CALL_3(bpf_get_stackid_raw_tp,struct bpf_raw_tracepoint_args *,args,struct bpf_map *,map,u64,flags)1873 BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args,
1874 	   struct bpf_map *, map, u64, flags)
1875 {
1876 	struct pt_regs *regs = get_bpf_raw_tp_regs();
1877 	int ret;
1878 
1879 	if (IS_ERR(regs))
1880 		return PTR_ERR(regs);
1881 
1882 	perf_fetch_caller_regs(regs);
1883 	/* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */
1884 	ret = bpf_get_stackid((unsigned long) regs, (unsigned long) map,
1885 			      flags, 0, 0);
1886 	put_bpf_raw_tp_regs();
1887 	return ret;
1888 }
1889 
1890 static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = {
1891 	.func		= bpf_get_stackid_raw_tp,
1892 	.gpl_only	= true,
1893 	.ret_type	= RET_INTEGER,
1894 	.arg1_type	= ARG_PTR_TO_CTX,
1895 	.arg2_type	= ARG_CONST_MAP_PTR,
1896 	.arg3_type	= ARG_ANYTHING,
1897 };
1898 
BPF_CALL_4(bpf_get_stack_raw_tp,struct bpf_raw_tracepoint_args *,args,void *,buf,u32,size,u64,flags)1899 BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args,
1900 	   void *, buf, u32, size, u64, flags)
1901 {
1902 	struct pt_regs *regs = get_bpf_raw_tp_regs();
1903 	int ret;
1904 
1905 	if (IS_ERR(regs))
1906 		return PTR_ERR(regs);
1907 
1908 	perf_fetch_caller_regs(regs);
1909 	ret = bpf_get_stack((unsigned long) regs, (unsigned long) buf,
1910 			    (unsigned long) size, flags, 0);
1911 	put_bpf_raw_tp_regs();
1912 	return ret;
1913 }
1914 
1915 static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = {
1916 	.func		= bpf_get_stack_raw_tp,
1917 	.gpl_only	= true,
1918 	.ret_type	= RET_INTEGER,
1919 	.arg1_type	= ARG_PTR_TO_CTX,
1920 	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
1921 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
1922 	.arg4_type	= ARG_ANYTHING,
1923 };
1924 
1925 static const struct bpf_func_proto *
raw_tp_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1926 raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1927 {
1928 	switch (func_id) {
1929 	case BPF_FUNC_perf_event_output:
1930 		return &bpf_perf_event_output_proto_raw_tp;
1931 	case BPF_FUNC_get_stackid:
1932 		return &bpf_get_stackid_proto_raw_tp;
1933 	case BPF_FUNC_get_stack:
1934 		return &bpf_get_stack_proto_raw_tp;
1935 	case BPF_FUNC_get_attach_cookie:
1936 		return &bpf_get_attach_cookie_proto_tracing;
1937 	default:
1938 		return bpf_tracing_func_proto(func_id, prog);
1939 	}
1940 }
1941 
1942 const struct bpf_func_proto *
tracing_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1943 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1944 {
1945 	const struct bpf_func_proto *fn;
1946 
1947 	switch (func_id) {
1948 #ifdef CONFIG_NET
1949 	case BPF_FUNC_skb_output:
1950 		return &bpf_skb_output_proto;
1951 	case BPF_FUNC_xdp_output:
1952 		return &bpf_xdp_output_proto;
1953 	case BPF_FUNC_skc_to_tcp6_sock:
1954 		return &bpf_skc_to_tcp6_sock_proto;
1955 	case BPF_FUNC_skc_to_tcp_sock:
1956 		return &bpf_skc_to_tcp_sock_proto;
1957 	case BPF_FUNC_skc_to_tcp_timewait_sock:
1958 		return &bpf_skc_to_tcp_timewait_sock_proto;
1959 	case BPF_FUNC_skc_to_tcp_request_sock:
1960 		return &bpf_skc_to_tcp_request_sock_proto;
1961 	case BPF_FUNC_skc_to_udp6_sock:
1962 		return &bpf_skc_to_udp6_sock_proto;
1963 	case BPF_FUNC_skc_to_unix_sock:
1964 		return &bpf_skc_to_unix_sock_proto;
1965 	case BPF_FUNC_skc_to_mptcp_sock:
1966 		return &bpf_skc_to_mptcp_sock_proto;
1967 	case BPF_FUNC_sk_storage_get:
1968 		return &bpf_sk_storage_get_tracing_proto;
1969 	case BPF_FUNC_sk_storage_delete:
1970 		return &bpf_sk_storage_delete_tracing_proto;
1971 	case BPF_FUNC_sock_from_file:
1972 		return &bpf_sock_from_file_proto;
1973 	case BPF_FUNC_get_socket_cookie:
1974 		return &bpf_get_socket_ptr_cookie_proto;
1975 	case BPF_FUNC_xdp_get_buff_len:
1976 		return &bpf_xdp_get_buff_len_trace_proto;
1977 #endif
1978 	case BPF_FUNC_seq_printf:
1979 		return prog->expected_attach_type == BPF_TRACE_ITER ?
1980 		       &bpf_seq_printf_proto :
1981 		       NULL;
1982 	case BPF_FUNC_seq_write:
1983 		return prog->expected_attach_type == BPF_TRACE_ITER ?
1984 		       &bpf_seq_write_proto :
1985 		       NULL;
1986 	case BPF_FUNC_seq_printf_btf:
1987 		return prog->expected_attach_type == BPF_TRACE_ITER ?
1988 		       &bpf_seq_printf_btf_proto :
1989 		       NULL;
1990 	case BPF_FUNC_d_path:
1991 		return &bpf_d_path_proto;
1992 	case BPF_FUNC_get_func_arg:
1993 		return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_proto : NULL;
1994 	case BPF_FUNC_get_func_ret:
1995 		return bpf_prog_has_trampoline(prog) ? &bpf_get_func_ret_proto : NULL;
1996 	case BPF_FUNC_get_func_arg_cnt:
1997 		return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_cnt_proto : NULL;
1998 	case BPF_FUNC_get_attach_cookie:
1999 		if (prog->type == BPF_PROG_TYPE_TRACING &&
2000 		    prog->expected_attach_type == BPF_TRACE_RAW_TP)
2001 			return &bpf_get_attach_cookie_proto_tracing;
2002 		return bpf_prog_has_trampoline(prog) ? &bpf_get_attach_cookie_proto_tracing : NULL;
2003 	default:
2004 		fn = raw_tp_prog_func_proto(func_id, prog);
2005 		if (!fn && prog->expected_attach_type == BPF_TRACE_ITER)
2006 			fn = bpf_iter_get_func_proto(func_id, prog);
2007 		return fn;
2008 	}
2009 }
2010 
raw_tp_prog_is_valid_access(int off,int size,enum bpf_access_type type,const struct bpf_prog * prog,struct bpf_insn_access_aux * info)2011 static bool raw_tp_prog_is_valid_access(int off, int size,
2012 					enum bpf_access_type type,
2013 					const struct bpf_prog *prog,
2014 					struct bpf_insn_access_aux *info)
2015 {
2016 	return bpf_tracing_ctx_access(off, size, type);
2017 }
2018 
tracing_prog_is_valid_access(int off,int size,enum bpf_access_type type,const struct bpf_prog * prog,struct bpf_insn_access_aux * info)2019 static bool tracing_prog_is_valid_access(int off, int size,
2020 					 enum bpf_access_type type,
2021 					 const struct bpf_prog *prog,
2022 					 struct bpf_insn_access_aux *info)
2023 {
2024 	return bpf_tracing_btf_ctx_access(off, size, type, prog, info);
2025 }
2026 
bpf_prog_test_run_tracing(struct bpf_prog * prog,const union bpf_attr * kattr,union bpf_attr __user * uattr)2027 int __weak bpf_prog_test_run_tracing(struct bpf_prog *prog,
2028 				     const union bpf_attr *kattr,
2029 				     union bpf_attr __user *uattr)
2030 {
2031 	return -ENOTSUPP;
2032 }
2033 
2034 const struct bpf_verifier_ops raw_tracepoint_verifier_ops = {
2035 	.get_func_proto  = raw_tp_prog_func_proto,
2036 	.is_valid_access = raw_tp_prog_is_valid_access,
2037 };
2038 
2039 const struct bpf_prog_ops raw_tracepoint_prog_ops = {
2040 #ifdef CONFIG_NET
2041 	.test_run = bpf_prog_test_run_raw_tp,
2042 #endif
2043 };
2044 
2045 const struct bpf_verifier_ops tracing_verifier_ops = {
2046 	.get_func_proto  = tracing_prog_func_proto,
2047 	.is_valid_access = tracing_prog_is_valid_access,
2048 };
2049 
2050 const struct bpf_prog_ops tracing_prog_ops = {
2051 	.test_run = bpf_prog_test_run_tracing,
2052 };
2053 
raw_tp_writable_prog_is_valid_access(int off,int size,enum bpf_access_type type,const struct bpf_prog * prog,struct bpf_insn_access_aux * info)2054 static bool raw_tp_writable_prog_is_valid_access(int off, int size,
2055 						 enum bpf_access_type type,
2056 						 const struct bpf_prog *prog,
2057 						 struct bpf_insn_access_aux *info)
2058 {
2059 	if (off == 0) {
2060 		if (size != sizeof(u64) || type != BPF_READ)
2061 			return false;
2062 		info->reg_type = PTR_TO_TP_BUFFER;
2063 	}
2064 	return raw_tp_prog_is_valid_access(off, size, type, prog, info);
2065 }
2066 
2067 const struct bpf_verifier_ops raw_tracepoint_writable_verifier_ops = {
2068 	.get_func_proto  = raw_tp_prog_func_proto,
2069 	.is_valid_access = raw_tp_writable_prog_is_valid_access,
2070 };
2071 
2072 const struct bpf_prog_ops raw_tracepoint_writable_prog_ops = {
2073 };
2074 
pe_prog_is_valid_access(int off,int size,enum bpf_access_type type,const struct bpf_prog * prog,struct bpf_insn_access_aux * info)2075 static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
2076 				    const struct bpf_prog *prog,
2077 				    struct bpf_insn_access_aux *info)
2078 {
2079 	const int size_u64 = sizeof(u64);
2080 
2081 	if (off < 0 || off >= sizeof(struct bpf_perf_event_data))
2082 		return false;
2083 	if (type != BPF_READ)
2084 		return false;
2085 	if (off % size != 0) {
2086 		if (sizeof(unsigned long) != 4)
2087 			return false;
2088 		if (size != 8)
2089 			return false;
2090 		if (off % size != 4)
2091 			return false;
2092 	}
2093 
2094 	switch (off) {
2095 	case bpf_ctx_range(struct bpf_perf_event_data, sample_period):
2096 		bpf_ctx_record_field_size(info, size_u64);
2097 		if (!bpf_ctx_narrow_access_ok(off, size, size_u64))
2098 			return false;
2099 		break;
2100 	case bpf_ctx_range(struct bpf_perf_event_data, addr):
2101 		bpf_ctx_record_field_size(info, size_u64);
2102 		if (!bpf_ctx_narrow_access_ok(off, size, size_u64))
2103 			return false;
2104 		break;
2105 	default:
2106 		if (size != sizeof(long))
2107 			return false;
2108 	}
2109 
2110 	return true;
2111 }
2112 
pe_prog_convert_ctx_access(enum bpf_access_type type,const struct bpf_insn * si,struct bpf_insn * insn_buf,struct bpf_prog * prog,u32 * target_size)2113 static u32 pe_prog_convert_ctx_access(enum bpf_access_type type,
2114 				      const struct bpf_insn *si,
2115 				      struct bpf_insn *insn_buf,
2116 				      struct bpf_prog *prog, u32 *target_size)
2117 {
2118 	struct bpf_insn *insn = insn_buf;
2119 
2120 	switch (si->off) {
2121 	case offsetof(struct bpf_perf_event_data, sample_period):
2122 		*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
2123 						       data), si->dst_reg, si->src_reg,
2124 				      offsetof(struct bpf_perf_event_data_kern, data));
2125 		*insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg,
2126 				      bpf_target_off(struct perf_sample_data, period, 8,
2127 						     target_size));
2128 		break;
2129 	case offsetof(struct bpf_perf_event_data, addr):
2130 		*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
2131 						       data), si->dst_reg, si->src_reg,
2132 				      offsetof(struct bpf_perf_event_data_kern, data));
2133 		*insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg,
2134 				      bpf_target_off(struct perf_sample_data, addr, 8,
2135 						     target_size));
2136 		break;
2137 	default:
2138 		*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
2139 						       regs), si->dst_reg, si->src_reg,
2140 				      offsetof(struct bpf_perf_event_data_kern, regs));
2141 		*insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg,
2142 				      si->off);
2143 		break;
2144 	}
2145 
2146 	return insn - insn_buf;
2147 }
2148 
2149 const struct bpf_verifier_ops perf_event_verifier_ops = {
2150 	.get_func_proto		= pe_prog_func_proto,
2151 	.is_valid_access	= pe_prog_is_valid_access,
2152 	.convert_ctx_access	= pe_prog_convert_ctx_access,
2153 };
2154 
2155 const struct bpf_prog_ops perf_event_prog_ops = {
2156 };
2157 
2158 static DEFINE_MUTEX(bpf_event_mutex);
2159 
2160 #define BPF_TRACE_MAX_PROGS 64
2161 
perf_event_attach_bpf_prog(struct perf_event * event,struct bpf_prog * prog,u64 bpf_cookie)2162 int perf_event_attach_bpf_prog(struct perf_event *event,
2163 			       struct bpf_prog *prog,
2164 			       u64 bpf_cookie)
2165 {
2166 	struct bpf_prog_array *old_array;
2167 	struct bpf_prog_array *new_array;
2168 	int ret = -EEXIST;
2169 
2170 	/*
2171 	 * Kprobe override only works if they are on the function entry,
2172 	 * and only if they are on the opt-in list.
2173 	 */
2174 	if (prog->kprobe_override &&
2175 	    (!trace_kprobe_on_func_entry(event->tp_event) ||
2176 	     !trace_kprobe_error_injectable(event->tp_event)))
2177 		return -EINVAL;
2178 
2179 	mutex_lock(&bpf_event_mutex);
2180 
2181 	if (event->prog)
2182 		goto unlock;
2183 
2184 	old_array = bpf_event_rcu_dereference(event->tp_event->prog_array);
2185 	if (old_array &&
2186 	    bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) {
2187 		ret = -E2BIG;
2188 		goto unlock;
2189 	}
2190 
2191 	ret = bpf_prog_array_copy(old_array, NULL, prog, bpf_cookie, &new_array);
2192 	if (ret < 0)
2193 		goto unlock;
2194 
2195 	/* set the new array to event->tp_event and set event->prog */
2196 	event->prog = prog;
2197 	event->bpf_cookie = bpf_cookie;
2198 	rcu_assign_pointer(event->tp_event->prog_array, new_array);
2199 	bpf_prog_array_free_sleepable(old_array);
2200 
2201 unlock:
2202 	mutex_unlock(&bpf_event_mutex);
2203 	return ret;
2204 }
2205 
perf_event_detach_bpf_prog(struct perf_event * event)2206 void perf_event_detach_bpf_prog(struct perf_event *event)
2207 {
2208 	struct bpf_prog_array *old_array;
2209 	struct bpf_prog_array *new_array;
2210 	int ret;
2211 
2212 	mutex_lock(&bpf_event_mutex);
2213 
2214 	if (!event->prog)
2215 		goto unlock;
2216 
2217 	old_array = bpf_event_rcu_dereference(event->tp_event->prog_array);
2218 	ret = bpf_prog_array_copy(old_array, event->prog, NULL, 0, &new_array);
2219 	if (ret < 0) {
2220 		bpf_prog_array_delete_safe(old_array, event->prog);
2221 	} else {
2222 		rcu_assign_pointer(event->tp_event->prog_array, new_array);
2223 		bpf_prog_array_free_sleepable(old_array);
2224 	}
2225 
2226 	bpf_prog_put(event->prog);
2227 	event->prog = NULL;
2228 
2229 unlock:
2230 	mutex_unlock(&bpf_event_mutex);
2231 }
2232 
perf_event_query_prog_array(struct perf_event * event,void __user * info)2233 int perf_event_query_prog_array(struct perf_event *event, void __user *info)
2234 {
2235 	struct perf_event_query_bpf __user *uquery = info;
2236 	struct perf_event_query_bpf query = {};
2237 	struct bpf_prog_array *progs;
2238 	u32 *ids, prog_cnt, ids_len;
2239 	int ret;
2240 
2241 	if (!perfmon_capable())
2242 		return -EPERM;
2243 	if (event->attr.type != PERF_TYPE_TRACEPOINT)
2244 		return -EINVAL;
2245 	if (copy_from_user(&query, uquery, sizeof(query)))
2246 		return -EFAULT;
2247 
2248 	ids_len = query.ids_len;
2249 	if (ids_len > BPF_TRACE_MAX_PROGS)
2250 		return -E2BIG;
2251 	ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN);
2252 	if (!ids)
2253 		return -ENOMEM;
2254 	/*
2255 	 * The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which
2256 	 * is required when user only wants to check for uquery->prog_cnt.
2257 	 * There is no need to check for it since the case is handled
2258 	 * gracefully in bpf_prog_array_copy_info.
2259 	 */
2260 
2261 	mutex_lock(&bpf_event_mutex);
2262 	progs = bpf_event_rcu_dereference(event->tp_event->prog_array);
2263 	ret = bpf_prog_array_copy_info(progs, ids, ids_len, &prog_cnt);
2264 	mutex_unlock(&bpf_event_mutex);
2265 
2266 	if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) ||
2267 	    copy_to_user(uquery->ids, ids, ids_len * sizeof(u32)))
2268 		ret = -EFAULT;
2269 
2270 	kfree(ids);
2271 	return ret;
2272 }
2273 
2274 extern struct bpf_raw_event_map __start__bpf_raw_tp[];
2275 extern struct bpf_raw_event_map __stop__bpf_raw_tp[];
2276 
bpf_get_raw_tracepoint(const char * name)2277 struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name)
2278 {
2279 	struct bpf_raw_event_map *btp = __start__bpf_raw_tp;
2280 
2281 	for (; btp < __stop__bpf_raw_tp; btp++) {
2282 		if (!strcmp(btp->tp->name, name))
2283 			return btp;
2284 	}
2285 
2286 	return bpf_get_raw_tracepoint_module(name);
2287 }
2288 
bpf_put_raw_tracepoint(struct bpf_raw_event_map * btp)2289 void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp)
2290 {
2291 	struct module *mod;
2292 
2293 	preempt_disable();
2294 	mod = __module_address((unsigned long)btp);
2295 	module_put(mod);
2296 	preempt_enable();
2297 }
2298 
2299 static __always_inline
__bpf_trace_run(struct bpf_raw_tp_link * link,u64 * args)2300 void __bpf_trace_run(struct bpf_raw_tp_link *link, u64 *args)
2301 {
2302 	struct bpf_prog *prog = link->link.prog;
2303 	struct bpf_run_ctx *old_run_ctx;
2304 	struct bpf_trace_run_ctx run_ctx;
2305 
2306 	cant_sleep();
2307 	if (unlikely(this_cpu_inc_return(*(prog->active)) != 1)) {
2308 		bpf_prog_inc_misses_counter(prog);
2309 		goto out;
2310 	}
2311 
2312 	run_ctx.bpf_cookie = link->cookie;
2313 	old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx);
2314 
2315 	rcu_read_lock();
2316 	(void) bpf_prog_run(prog, args);
2317 	rcu_read_unlock();
2318 
2319 	bpf_reset_run_ctx(old_run_ctx);
2320 out:
2321 	this_cpu_dec(*(prog->active));
2322 }
2323 
2324 #define UNPACK(...)			__VA_ARGS__
2325 #define REPEAT_1(FN, DL, X, ...)	FN(X)
2326 #define REPEAT_2(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__)
2327 #define REPEAT_3(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_2(FN, DL, __VA_ARGS__)
2328 #define REPEAT_4(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_3(FN, DL, __VA_ARGS__)
2329 #define REPEAT_5(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_4(FN, DL, __VA_ARGS__)
2330 #define REPEAT_6(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_5(FN, DL, __VA_ARGS__)
2331 #define REPEAT_7(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_6(FN, DL, __VA_ARGS__)
2332 #define REPEAT_8(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_7(FN, DL, __VA_ARGS__)
2333 #define REPEAT_9(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_8(FN, DL, __VA_ARGS__)
2334 #define REPEAT_10(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_9(FN, DL, __VA_ARGS__)
2335 #define REPEAT_11(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_10(FN, DL, __VA_ARGS__)
2336 #define REPEAT_12(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_11(FN, DL, __VA_ARGS__)
2337 #define REPEAT(X, FN, DL, ...)		REPEAT_##X(FN, DL, __VA_ARGS__)
2338 
2339 #define SARG(X)		u64 arg##X
2340 #define COPY(X)		args[X] = arg##X
2341 
2342 #define __DL_COM	(,)
2343 #define __DL_SEM	(;)
2344 
2345 #define __SEQ_0_11	0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11
2346 
2347 #define BPF_TRACE_DEFN_x(x)						\
2348 	void bpf_trace_run##x(struct bpf_raw_tp_link *link,		\
2349 			      REPEAT(x, SARG, __DL_COM, __SEQ_0_11))	\
2350 	{								\
2351 		u64 args[x];						\
2352 		REPEAT(x, COPY, __DL_SEM, __SEQ_0_11);			\
2353 		__bpf_trace_run(link, args);				\
2354 	}								\
2355 	EXPORT_SYMBOL_GPL(bpf_trace_run##x)
2356 BPF_TRACE_DEFN_x(1);
2357 BPF_TRACE_DEFN_x(2);
2358 BPF_TRACE_DEFN_x(3);
2359 BPF_TRACE_DEFN_x(4);
2360 BPF_TRACE_DEFN_x(5);
2361 BPF_TRACE_DEFN_x(6);
2362 BPF_TRACE_DEFN_x(7);
2363 BPF_TRACE_DEFN_x(8);
2364 BPF_TRACE_DEFN_x(9);
2365 BPF_TRACE_DEFN_x(10);
2366 BPF_TRACE_DEFN_x(11);
2367 BPF_TRACE_DEFN_x(12);
2368 
bpf_probe_register(struct bpf_raw_event_map * btp,struct bpf_raw_tp_link * link)2369 int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_raw_tp_link *link)
2370 {
2371 	struct tracepoint *tp = btp->tp;
2372 	struct bpf_prog *prog = link->link.prog;
2373 
2374 	/*
2375 	 * check that program doesn't access arguments beyond what's
2376 	 * available in this tracepoint
2377 	 */
2378 	if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64))
2379 		return -EINVAL;
2380 
2381 	if (prog->aux->max_tp_access > btp->writable_size)
2382 		return -EINVAL;
2383 
2384 	return tracepoint_probe_register_may_exist(tp, (void *)btp->bpf_func, link);
2385 }
2386 
bpf_probe_unregister(struct bpf_raw_event_map * btp,struct bpf_raw_tp_link * link)2387 int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_raw_tp_link *link)
2388 {
2389 	return tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, link);
2390 }
2391 
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)2392 int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id,
2393 			    u32 *fd_type, const char **buf,
2394 			    u64 *probe_offset, u64 *probe_addr,
2395 			    unsigned long *missed)
2396 {
2397 	bool is_tracepoint, is_syscall_tp;
2398 	struct bpf_prog *prog;
2399 	int flags, err = 0;
2400 
2401 	prog = event->prog;
2402 	if (!prog)
2403 		return -ENOENT;
2404 
2405 	/* not supporting BPF_PROG_TYPE_PERF_EVENT yet */
2406 	if (prog->type == BPF_PROG_TYPE_PERF_EVENT)
2407 		return -EOPNOTSUPP;
2408 
2409 	*prog_id = prog->aux->id;
2410 	flags = event->tp_event->flags;
2411 	is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT;
2412 	is_syscall_tp = is_syscall_trace_event(event->tp_event);
2413 
2414 	if (is_tracepoint || is_syscall_tp) {
2415 		*buf = is_tracepoint ? event->tp_event->tp->name
2416 				     : event->tp_event->name;
2417 		/* We allow NULL pointer for tracepoint */
2418 		if (fd_type)
2419 			*fd_type = BPF_FD_TYPE_TRACEPOINT;
2420 		if (probe_offset)
2421 			*probe_offset = 0x0;
2422 		if (probe_addr)
2423 			*probe_addr = 0x0;
2424 	} else {
2425 		/* kprobe/uprobe */
2426 		err = -EOPNOTSUPP;
2427 #ifdef CONFIG_KPROBE_EVENTS
2428 		if (flags & TRACE_EVENT_FL_KPROBE)
2429 			err = bpf_get_kprobe_info(event, fd_type, buf,
2430 						  probe_offset, probe_addr, missed,
2431 						  event->attr.type == PERF_TYPE_TRACEPOINT);
2432 #endif
2433 #ifdef CONFIG_UPROBE_EVENTS
2434 		if (flags & TRACE_EVENT_FL_UPROBE)
2435 			err = bpf_get_uprobe_info(event, fd_type, buf,
2436 						  probe_offset, probe_addr,
2437 						  event->attr.type == PERF_TYPE_TRACEPOINT);
2438 #endif
2439 	}
2440 
2441 	return err;
2442 }
2443 
send_signal_irq_work_init(void)2444 static int __init send_signal_irq_work_init(void)
2445 {
2446 	int cpu;
2447 	struct send_signal_irq_work *work;
2448 
2449 	for_each_possible_cpu(cpu) {
2450 		work = per_cpu_ptr(&send_signal_work, cpu);
2451 		init_irq_work(&work->irq_work, do_bpf_send_signal);
2452 	}
2453 	return 0;
2454 }
2455 
2456 subsys_initcall(send_signal_irq_work_init);
2457 
2458 #ifdef CONFIG_MODULES
bpf_event_notify(struct notifier_block * nb,unsigned long op,void * module)2459 static int bpf_event_notify(struct notifier_block *nb, unsigned long op,
2460 			    void *module)
2461 {
2462 	struct bpf_trace_module *btm, *tmp;
2463 	struct module *mod = module;
2464 	int ret = 0;
2465 
2466 	if (mod->num_bpf_raw_events == 0 ||
2467 	    (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING))
2468 		goto out;
2469 
2470 	mutex_lock(&bpf_module_mutex);
2471 
2472 	switch (op) {
2473 	case MODULE_STATE_COMING:
2474 		btm = kzalloc(sizeof(*btm), GFP_KERNEL);
2475 		if (btm) {
2476 			btm->module = module;
2477 			list_add(&btm->list, &bpf_trace_modules);
2478 		} else {
2479 			ret = -ENOMEM;
2480 		}
2481 		break;
2482 	case MODULE_STATE_GOING:
2483 		list_for_each_entry_safe(btm, tmp, &bpf_trace_modules, list) {
2484 			if (btm->module == module) {
2485 				list_del(&btm->list);
2486 				kfree(btm);
2487 				break;
2488 			}
2489 		}
2490 		break;
2491 	}
2492 
2493 	mutex_unlock(&bpf_module_mutex);
2494 
2495 out:
2496 	return notifier_from_errno(ret);
2497 }
2498 
2499 static struct notifier_block bpf_module_nb = {
2500 	.notifier_call = bpf_event_notify,
2501 };
2502 
bpf_event_init(void)2503 static int __init bpf_event_init(void)
2504 {
2505 	register_module_notifier(&bpf_module_nb);
2506 	return 0;
2507 }
2508 
2509 fs_initcall(bpf_event_init);
2510 #endif /* CONFIG_MODULES */
2511 
2512 struct bpf_session_run_ctx {
2513 	struct bpf_run_ctx run_ctx;
2514 	bool is_return;
2515 	void *data;
2516 };
2517 
2518 #ifdef CONFIG_FPROBE
2519 struct bpf_kprobe_multi_link {
2520 	struct bpf_link link;
2521 	struct fprobe fp;
2522 	unsigned long *addrs;
2523 	u64 *cookies;
2524 	u32 cnt;
2525 	u32 mods_cnt;
2526 	struct module **mods;
2527 	u32 flags;
2528 };
2529 
2530 struct bpf_kprobe_multi_run_ctx {
2531 	struct bpf_session_run_ctx session_ctx;
2532 	struct bpf_kprobe_multi_link *link;
2533 	unsigned long entry_ip;
2534 };
2535 
2536 struct user_syms {
2537 	const char **syms;
2538 	char *buf;
2539 };
2540 
copy_user_syms(struct user_syms * us,unsigned long __user * usyms,u32 cnt)2541 static int copy_user_syms(struct user_syms *us, unsigned long __user *usyms, u32 cnt)
2542 {
2543 	unsigned long __user usymbol;
2544 	const char **syms = NULL;
2545 	char *buf = NULL, *p;
2546 	int err = -ENOMEM;
2547 	unsigned int i;
2548 
2549 	syms = kvmalloc_array(cnt, sizeof(*syms), GFP_KERNEL);
2550 	if (!syms)
2551 		goto error;
2552 
2553 	buf = kvmalloc_array(cnt, KSYM_NAME_LEN, GFP_KERNEL);
2554 	if (!buf)
2555 		goto error;
2556 
2557 	for (p = buf, i = 0; i < cnt; i++) {
2558 		if (__get_user(usymbol, usyms + i)) {
2559 			err = -EFAULT;
2560 			goto error;
2561 		}
2562 		err = strncpy_from_user(p, (const char __user *) usymbol, KSYM_NAME_LEN);
2563 		if (err == KSYM_NAME_LEN)
2564 			err = -E2BIG;
2565 		if (err < 0)
2566 			goto error;
2567 		syms[i] = p;
2568 		p += err + 1;
2569 	}
2570 
2571 	us->syms = syms;
2572 	us->buf = buf;
2573 	return 0;
2574 
2575 error:
2576 	if (err) {
2577 		kvfree(syms);
2578 		kvfree(buf);
2579 	}
2580 	return err;
2581 }
2582 
kprobe_multi_put_modules(struct module ** mods,u32 cnt)2583 static void kprobe_multi_put_modules(struct module **mods, u32 cnt)
2584 {
2585 	u32 i;
2586 
2587 	for (i = 0; i < cnt; i++)
2588 		module_put(mods[i]);
2589 }
2590 
free_user_syms(struct user_syms * us)2591 static void free_user_syms(struct user_syms *us)
2592 {
2593 	kvfree(us->syms);
2594 	kvfree(us->buf);
2595 }
2596 
bpf_kprobe_multi_link_release(struct bpf_link * link)2597 static void bpf_kprobe_multi_link_release(struct bpf_link *link)
2598 {
2599 	struct bpf_kprobe_multi_link *kmulti_link;
2600 
2601 	kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);
2602 	unregister_fprobe(&kmulti_link->fp);
2603 	kprobe_multi_put_modules(kmulti_link->mods, kmulti_link->mods_cnt);
2604 }
2605 
bpf_kprobe_multi_link_dealloc(struct bpf_link * link)2606 static void bpf_kprobe_multi_link_dealloc(struct bpf_link *link)
2607 {
2608 	struct bpf_kprobe_multi_link *kmulti_link;
2609 
2610 	kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);
2611 	kvfree(kmulti_link->addrs);
2612 	kvfree(kmulti_link->cookies);
2613 	kfree(kmulti_link->mods);
2614 	kfree(kmulti_link);
2615 }
2616 
bpf_kprobe_multi_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)2617 static int bpf_kprobe_multi_link_fill_link_info(const struct bpf_link *link,
2618 						struct bpf_link_info *info)
2619 {
2620 	u64 __user *ucookies = u64_to_user_ptr(info->kprobe_multi.cookies);
2621 	u64 __user *uaddrs = u64_to_user_ptr(info->kprobe_multi.addrs);
2622 	struct bpf_kprobe_multi_link *kmulti_link;
2623 	u32 ucount = info->kprobe_multi.count;
2624 	int err = 0, i;
2625 
2626 	if (!uaddrs ^ !ucount)
2627 		return -EINVAL;
2628 	if (ucookies && !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 	info->kprobe_multi.missed = kmulti_link->fp.nmissed;
2635 
2636 	if (!uaddrs)
2637 		return 0;
2638 	if (ucount < kmulti_link->cnt)
2639 		err = -ENOSPC;
2640 	else
2641 		ucount = kmulti_link->cnt;
2642 
2643 	if (ucookies) {
2644 		if (kmulti_link->cookies) {
2645 			if (copy_to_user(ucookies, kmulti_link->cookies, ucount * sizeof(u64)))
2646 				return -EFAULT;
2647 		} else {
2648 			for (i = 0; i < ucount; i++) {
2649 				if (put_user(0, ucookies + i))
2650 					return -EFAULT;
2651 			}
2652 		}
2653 	}
2654 
2655 	if (kallsyms_show_value(current_cred())) {
2656 		if (copy_to_user(uaddrs, kmulti_link->addrs, ucount * sizeof(u64)))
2657 			return -EFAULT;
2658 	} else {
2659 		for (i = 0; i < ucount; i++) {
2660 			if (put_user(0, uaddrs + i))
2661 				return -EFAULT;
2662 		}
2663 	}
2664 	return err;
2665 }
2666 
2667 static const struct bpf_link_ops bpf_kprobe_multi_link_lops = {
2668 	.release = bpf_kprobe_multi_link_release,
2669 	.dealloc_deferred = bpf_kprobe_multi_link_dealloc,
2670 	.fill_link_info = bpf_kprobe_multi_link_fill_link_info,
2671 };
2672 
bpf_kprobe_multi_cookie_swap(void * a,void * b,int size,const void * priv)2673 static void bpf_kprobe_multi_cookie_swap(void *a, void *b, int size, const void *priv)
2674 {
2675 	const struct bpf_kprobe_multi_link *link = priv;
2676 	unsigned long *addr_a = a, *addr_b = b;
2677 	u64 *cookie_a, *cookie_b;
2678 
2679 	cookie_a = link->cookies + (addr_a - link->addrs);
2680 	cookie_b = link->cookies + (addr_b - link->addrs);
2681 
2682 	/* swap addr_a/addr_b and cookie_a/cookie_b values */
2683 	swap(*addr_a, *addr_b);
2684 	swap(*cookie_a, *cookie_b);
2685 }
2686 
bpf_kprobe_multi_addrs_cmp(const void * a,const void * b)2687 static int bpf_kprobe_multi_addrs_cmp(const void *a, const void *b)
2688 {
2689 	const unsigned long *addr_a = a, *addr_b = b;
2690 
2691 	if (*addr_a == *addr_b)
2692 		return 0;
2693 	return *addr_a < *addr_b ? -1 : 1;
2694 }
2695 
bpf_kprobe_multi_cookie_cmp(const void * a,const void * b,const void * priv)2696 static int bpf_kprobe_multi_cookie_cmp(const void *a, const void *b, const void *priv)
2697 {
2698 	return bpf_kprobe_multi_addrs_cmp(a, b);
2699 }
2700 
bpf_kprobe_multi_cookie(struct bpf_run_ctx * ctx)2701 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx)
2702 {
2703 	struct bpf_kprobe_multi_run_ctx *run_ctx;
2704 	struct bpf_kprobe_multi_link *link;
2705 	u64 *cookie, entry_ip;
2706 	unsigned long *addr;
2707 
2708 	if (WARN_ON_ONCE(!ctx))
2709 		return 0;
2710 	run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx,
2711 			       session_ctx.run_ctx);
2712 	link = run_ctx->link;
2713 	if (!link->cookies)
2714 		return 0;
2715 	entry_ip = run_ctx->entry_ip;
2716 	addr = bsearch(&entry_ip, link->addrs, link->cnt, sizeof(entry_ip),
2717 		       bpf_kprobe_multi_addrs_cmp);
2718 	if (!addr)
2719 		return 0;
2720 	cookie = link->cookies + (addr - link->addrs);
2721 	return *cookie;
2722 }
2723 
bpf_kprobe_multi_entry_ip(struct bpf_run_ctx * ctx)2724 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
2725 {
2726 	struct bpf_kprobe_multi_run_ctx *run_ctx;
2727 
2728 	run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx,
2729 			       session_ctx.run_ctx);
2730 	return run_ctx->entry_ip;
2731 }
2732 
2733 static int
kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link * link,unsigned long entry_ip,struct pt_regs * regs,bool is_return,void * data)2734 kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link,
2735 			   unsigned long entry_ip, struct pt_regs *regs,
2736 			   bool is_return, void *data)
2737 {
2738 	struct bpf_kprobe_multi_run_ctx run_ctx = {
2739 		.session_ctx = {
2740 			.is_return = is_return,
2741 			.data = data,
2742 		},
2743 		.link = link,
2744 		.entry_ip = entry_ip,
2745 	};
2746 	struct bpf_run_ctx *old_run_ctx;
2747 	int err;
2748 
2749 	if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) {
2750 		bpf_prog_inc_misses_counter(link->link.prog);
2751 		err = 0;
2752 		goto out;
2753 	}
2754 
2755 	migrate_disable();
2756 	rcu_read_lock();
2757 	old_run_ctx = bpf_set_run_ctx(&run_ctx.session_ctx.run_ctx);
2758 	err = bpf_prog_run(link->link.prog, regs);
2759 	bpf_reset_run_ctx(old_run_ctx);
2760 	rcu_read_unlock();
2761 	migrate_enable();
2762 
2763  out:
2764 	__this_cpu_dec(bpf_prog_active);
2765 	return err;
2766 }
2767 
2768 static int
kprobe_multi_link_handler(struct fprobe * fp,unsigned long fentry_ip,unsigned long ret_ip,struct pt_regs * regs,void * data)2769 kprobe_multi_link_handler(struct fprobe *fp, unsigned long fentry_ip,
2770 			  unsigned long ret_ip, struct pt_regs *regs,
2771 			  void *data)
2772 {
2773 	struct bpf_kprobe_multi_link *link;
2774 	int err;
2775 
2776 	link = container_of(fp, struct bpf_kprobe_multi_link, fp);
2777 	err = kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), regs, false, data);
2778 	return is_kprobe_session(link->link.prog) ? err : 0;
2779 }
2780 
2781 static void
kprobe_multi_link_exit_handler(struct fprobe * fp,unsigned long fentry_ip,unsigned long ret_ip,struct pt_regs * regs,void * data)2782 kprobe_multi_link_exit_handler(struct fprobe *fp, unsigned long fentry_ip,
2783 			       unsigned long ret_ip, struct pt_regs *regs,
2784 			       void *data)
2785 {
2786 	struct bpf_kprobe_multi_link *link;
2787 
2788 	link = container_of(fp, struct bpf_kprobe_multi_link, fp);
2789 	kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), regs, true, data);
2790 }
2791 
symbols_cmp_r(const void * a,const void * b,const void * priv)2792 static int symbols_cmp_r(const void *a, const void *b, const void *priv)
2793 {
2794 	const char **str_a = (const char **) a;
2795 	const char **str_b = (const char **) b;
2796 
2797 	return strcmp(*str_a, *str_b);
2798 }
2799 
2800 struct multi_symbols_sort {
2801 	const char **funcs;
2802 	u64 *cookies;
2803 };
2804 
symbols_swap_r(void * a,void * b,int size,const void * priv)2805 static void symbols_swap_r(void *a, void *b, int size, const void *priv)
2806 {
2807 	const struct multi_symbols_sort *data = priv;
2808 	const char **name_a = a, **name_b = b;
2809 
2810 	swap(*name_a, *name_b);
2811 
2812 	/* If defined, swap also related cookies. */
2813 	if (data->cookies) {
2814 		u64 *cookie_a, *cookie_b;
2815 
2816 		cookie_a = data->cookies + (name_a - data->funcs);
2817 		cookie_b = data->cookies + (name_b - data->funcs);
2818 		swap(*cookie_a, *cookie_b);
2819 	}
2820 }
2821 
2822 struct modules_array {
2823 	struct module **mods;
2824 	int mods_cnt;
2825 	int mods_cap;
2826 };
2827 
add_module(struct modules_array * arr,struct module * mod)2828 static int add_module(struct modules_array *arr, struct module *mod)
2829 {
2830 	struct module **mods;
2831 
2832 	if (arr->mods_cnt == arr->mods_cap) {
2833 		arr->mods_cap = max(16, arr->mods_cap * 3 / 2);
2834 		mods = krealloc_array(arr->mods, arr->mods_cap, sizeof(*mods), GFP_KERNEL);
2835 		if (!mods)
2836 			return -ENOMEM;
2837 		arr->mods = mods;
2838 	}
2839 
2840 	arr->mods[arr->mods_cnt] = mod;
2841 	arr->mods_cnt++;
2842 	return 0;
2843 }
2844 
has_module(struct modules_array * arr,struct module * mod)2845 static bool has_module(struct modules_array *arr, struct module *mod)
2846 {
2847 	int i;
2848 
2849 	for (i = arr->mods_cnt - 1; i >= 0; i--) {
2850 		if (arr->mods[i] == mod)
2851 			return true;
2852 	}
2853 	return false;
2854 }
2855 
get_modules_for_addrs(struct module *** mods,unsigned long * addrs,u32 addrs_cnt)2856 static int get_modules_for_addrs(struct module ***mods, unsigned long *addrs, u32 addrs_cnt)
2857 {
2858 	struct modules_array arr = {};
2859 	u32 i, err = 0;
2860 
2861 	for (i = 0; i < addrs_cnt; i++) {
2862 		struct module *mod;
2863 
2864 		preempt_disable();
2865 		mod = __module_address(addrs[i]);
2866 		/* Either no module or we it's already stored  */
2867 		if (!mod || has_module(&arr, mod)) {
2868 			preempt_enable();
2869 			continue;
2870 		}
2871 		if (!try_module_get(mod))
2872 			err = -EINVAL;
2873 		preempt_enable();
2874 		if (err)
2875 			break;
2876 		err = add_module(&arr, mod);
2877 		if (err) {
2878 			module_put(mod);
2879 			break;
2880 		}
2881 	}
2882 
2883 	/* We return either err < 0 in case of error, ... */
2884 	if (err) {
2885 		kprobe_multi_put_modules(arr.mods, arr.mods_cnt);
2886 		kfree(arr.mods);
2887 		return err;
2888 	}
2889 
2890 	/* or number of modules found if everything is ok. */
2891 	*mods = arr.mods;
2892 	return arr.mods_cnt;
2893 }
2894 
addrs_check_error_injection_list(unsigned long * addrs,u32 cnt)2895 static int addrs_check_error_injection_list(unsigned long *addrs, u32 cnt)
2896 {
2897 	u32 i;
2898 
2899 	for (i = 0; i < cnt; i++) {
2900 		if (!within_error_injection_list(addrs[i]))
2901 			return -EINVAL;
2902 	}
2903 	return 0;
2904 }
2905 
bpf_kprobe_multi_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)2906 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
2907 {
2908 	struct bpf_kprobe_multi_link *link = NULL;
2909 	struct bpf_link_primer link_primer;
2910 	void __user *ucookies;
2911 	unsigned long *addrs;
2912 	u32 flags, cnt, size;
2913 	void __user *uaddrs;
2914 	u64 *cookies = NULL;
2915 	void __user *usyms;
2916 	int err;
2917 
2918 	/* no support for 32bit archs yet */
2919 	if (sizeof(u64) != sizeof(void *))
2920 		return -EOPNOTSUPP;
2921 
2922 	if (!is_kprobe_multi(prog))
2923 		return -EINVAL;
2924 
2925 	flags = attr->link_create.kprobe_multi.flags;
2926 	if (flags & ~BPF_F_KPROBE_MULTI_RETURN)
2927 		return -EINVAL;
2928 
2929 	uaddrs = u64_to_user_ptr(attr->link_create.kprobe_multi.addrs);
2930 	usyms = u64_to_user_ptr(attr->link_create.kprobe_multi.syms);
2931 	if (!!uaddrs == !!usyms)
2932 		return -EINVAL;
2933 
2934 	cnt = attr->link_create.kprobe_multi.cnt;
2935 	if (!cnt)
2936 		return -EINVAL;
2937 	if (cnt > MAX_KPROBE_MULTI_CNT)
2938 		return -E2BIG;
2939 
2940 	size = cnt * sizeof(*addrs);
2941 	addrs = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL);
2942 	if (!addrs)
2943 		return -ENOMEM;
2944 
2945 	ucookies = u64_to_user_ptr(attr->link_create.kprobe_multi.cookies);
2946 	if (ucookies) {
2947 		cookies = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL);
2948 		if (!cookies) {
2949 			err = -ENOMEM;
2950 			goto error;
2951 		}
2952 		if (copy_from_user(cookies, ucookies, size)) {
2953 			err = -EFAULT;
2954 			goto error;
2955 		}
2956 	}
2957 
2958 	if (uaddrs) {
2959 		if (copy_from_user(addrs, uaddrs, size)) {
2960 			err = -EFAULT;
2961 			goto error;
2962 		}
2963 	} else {
2964 		struct multi_symbols_sort data = {
2965 			.cookies = cookies,
2966 		};
2967 		struct user_syms us;
2968 
2969 		err = copy_user_syms(&us, usyms, cnt);
2970 		if (err)
2971 			goto error;
2972 
2973 		if (cookies)
2974 			data.funcs = us.syms;
2975 
2976 		sort_r(us.syms, cnt, sizeof(*us.syms), symbols_cmp_r,
2977 		       symbols_swap_r, &data);
2978 
2979 		err = ftrace_lookup_symbols(us.syms, cnt, addrs);
2980 		free_user_syms(&us);
2981 		if (err)
2982 			goto error;
2983 	}
2984 
2985 	if (prog->kprobe_override && addrs_check_error_injection_list(addrs, cnt)) {
2986 		err = -EINVAL;
2987 		goto error;
2988 	}
2989 
2990 	link = kzalloc(sizeof(*link), GFP_KERNEL);
2991 	if (!link) {
2992 		err = -ENOMEM;
2993 		goto error;
2994 	}
2995 
2996 	bpf_link_init(&link->link, BPF_LINK_TYPE_KPROBE_MULTI,
2997 		      &bpf_kprobe_multi_link_lops, prog);
2998 
2999 	err = bpf_link_prime(&link->link, &link_primer);
3000 	if (err)
3001 		goto error;
3002 
3003 	if (!(flags & BPF_F_KPROBE_MULTI_RETURN))
3004 		link->fp.entry_handler = kprobe_multi_link_handler;
3005 	if ((flags & BPF_F_KPROBE_MULTI_RETURN) || is_kprobe_session(prog))
3006 		link->fp.exit_handler = kprobe_multi_link_exit_handler;
3007 	if (is_kprobe_session(prog))
3008 		link->fp.entry_data_size = sizeof(u64);
3009 
3010 	link->addrs = addrs;
3011 	link->cookies = cookies;
3012 	link->cnt = cnt;
3013 	link->flags = flags;
3014 
3015 	if (cookies) {
3016 		/*
3017 		 * Sorting addresses will trigger sorting cookies as well
3018 		 * (check bpf_kprobe_multi_cookie_swap). This way we can
3019 		 * find cookie based on the address in bpf_get_attach_cookie
3020 		 * helper.
3021 		 */
3022 		sort_r(addrs, cnt, sizeof(*addrs),
3023 		       bpf_kprobe_multi_cookie_cmp,
3024 		       bpf_kprobe_multi_cookie_swap,
3025 		       link);
3026 	}
3027 
3028 	err = get_modules_for_addrs(&link->mods, addrs, cnt);
3029 	if (err < 0) {
3030 		bpf_link_cleanup(&link_primer);
3031 		return err;
3032 	}
3033 	link->mods_cnt = err;
3034 
3035 	err = register_fprobe_ips(&link->fp, addrs, cnt);
3036 	if (err) {
3037 		kprobe_multi_put_modules(link->mods, link->mods_cnt);
3038 		bpf_link_cleanup(&link_primer);
3039 		return err;
3040 	}
3041 
3042 	return bpf_link_settle(&link_primer);
3043 
3044 error:
3045 	kfree(link);
3046 	kvfree(addrs);
3047 	kvfree(cookies);
3048 	return err;
3049 }
3050 #else /* !CONFIG_FPROBE */
bpf_kprobe_multi_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)3051 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
3052 {
3053 	return -EOPNOTSUPP;
3054 }
bpf_kprobe_multi_cookie(struct bpf_run_ctx * ctx)3055 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx)
3056 {
3057 	return 0;
3058 }
bpf_kprobe_multi_entry_ip(struct bpf_run_ctx * ctx)3059 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
3060 {
3061 	return 0;
3062 }
3063 #endif
3064 
3065 #ifdef CONFIG_UPROBES
3066 struct bpf_uprobe_multi_link;
3067 
3068 struct bpf_uprobe {
3069 	struct bpf_uprobe_multi_link *link;
3070 	loff_t offset;
3071 	unsigned long ref_ctr_offset;
3072 	u64 cookie;
3073 	struct uprobe *uprobe;
3074 	struct uprobe_consumer consumer;
3075 };
3076 
3077 struct bpf_uprobe_multi_link {
3078 	struct path path;
3079 	struct bpf_link link;
3080 	u32 cnt;
3081 	u32 flags;
3082 	struct bpf_uprobe *uprobes;
3083 	struct task_struct *task;
3084 };
3085 
3086 struct bpf_uprobe_multi_run_ctx {
3087 	struct bpf_run_ctx run_ctx;
3088 	unsigned long entry_ip;
3089 	struct bpf_uprobe *uprobe;
3090 };
3091 
bpf_uprobe_unregister(struct bpf_uprobe * uprobes,u32 cnt)3092 static void bpf_uprobe_unregister(struct bpf_uprobe *uprobes, u32 cnt)
3093 {
3094 	u32 i;
3095 
3096 	for (i = 0; i < cnt; i++)
3097 		uprobe_unregister_nosync(uprobes[i].uprobe, &uprobes[i].consumer);
3098 
3099 	if (cnt)
3100 		uprobe_unregister_sync();
3101 }
3102 
bpf_uprobe_multi_link_release(struct bpf_link * link)3103 static void bpf_uprobe_multi_link_release(struct bpf_link *link)
3104 {
3105 	struct bpf_uprobe_multi_link *umulti_link;
3106 
3107 	umulti_link = container_of(link, struct bpf_uprobe_multi_link, link);
3108 	bpf_uprobe_unregister(umulti_link->uprobes, umulti_link->cnt);
3109 	if (umulti_link->task)
3110 		put_task_struct(umulti_link->task);
3111 	path_put(&umulti_link->path);
3112 }
3113 
bpf_uprobe_multi_link_dealloc(struct bpf_link * link)3114 static void bpf_uprobe_multi_link_dealloc(struct bpf_link *link)
3115 {
3116 	struct bpf_uprobe_multi_link *umulti_link;
3117 
3118 	umulti_link = container_of(link, struct bpf_uprobe_multi_link, link);
3119 	kvfree(umulti_link->uprobes);
3120 	kfree(umulti_link);
3121 }
3122 
bpf_uprobe_multi_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)3123 static int bpf_uprobe_multi_link_fill_link_info(const struct bpf_link *link,
3124 						struct bpf_link_info *info)
3125 {
3126 	u64 __user *uref_ctr_offsets = u64_to_user_ptr(info->uprobe_multi.ref_ctr_offsets);
3127 	u64 __user *ucookies = u64_to_user_ptr(info->uprobe_multi.cookies);
3128 	u64 __user *uoffsets = u64_to_user_ptr(info->uprobe_multi.offsets);
3129 	u64 __user *upath = u64_to_user_ptr(info->uprobe_multi.path);
3130 	u32 upath_size = info->uprobe_multi.path_size;
3131 	struct bpf_uprobe_multi_link *umulti_link;
3132 	u32 ucount = info->uprobe_multi.count;
3133 	int err = 0, i;
3134 	char *p, *buf;
3135 	long left = 0;
3136 
3137 	if (!upath ^ !upath_size)
3138 		return -EINVAL;
3139 
3140 	if ((uoffsets || uref_ctr_offsets || ucookies) && !ucount)
3141 		return -EINVAL;
3142 
3143 	umulti_link = container_of(link, struct bpf_uprobe_multi_link, link);
3144 	info->uprobe_multi.count = umulti_link->cnt;
3145 	info->uprobe_multi.flags = umulti_link->flags;
3146 	info->uprobe_multi.pid = umulti_link->task ?
3147 				 task_pid_nr_ns(umulti_link->task, task_active_pid_ns(current)) : 0;
3148 
3149 	upath_size = upath_size ? min_t(u32, upath_size, PATH_MAX) : PATH_MAX;
3150 	buf = kmalloc(upath_size, GFP_KERNEL);
3151 	if (!buf)
3152 		return -ENOMEM;
3153 	p = d_path(&umulti_link->path, buf, upath_size);
3154 	if (IS_ERR(p)) {
3155 		kfree(buf);
3156 		return PTR_ERR(p);
3157 	}
3158 	upath_size = buf + upath_size - p;
3159 
3160 	if (upath)
3161 		left = copy_to_user(upath, p, upath_size);
3162 	kfree(buf);
3163 	if (left)
3164 		return -EFAULT;
3165 	info->uprobe_multi.path_size = upath_size;
3166 
3167 	if (!uoffsets && !ucookies && !uref_ctr_offsets)
3168 		return 0;
3169 
3170 	if (ucount < umulti_link->cnt)
3171 		err = -ENOSPC;
3172 	else
3173 		ucount = umulti_link->cnt;
3174 
3175 	for (i = 0; i < ucount; i++) {
3176 		if (uoffsets &&
3177 		    put_user(umulti_link->uprobes[i].offset, uoffsets + i))
3178 			return -EFAULT;
3179 		if (uref_ctr_offsets &&
3180 		    put_user(umulti_link->uprobes[i].ref_ctr_offset, uref_ctr_offsets + i))
3181 			return -EFAULT;
3182 		if (ucookies &&
3183 		    put_user(umulti_link->uprobes[i].cookie, ucookies + i))
3184 			return -EFAULT;
3185 	}
3186 
3187 	return err;
3188 }
3189 
3190 static const struct bpf_link_ops bpf_uprobe_multi_link_lops = {
3191 	.release = bpf_uprobe_multi_link_release,
3192 	.dealloc_deferred = bpf_uprobe_multi_link_dealloc,
3193 	.fill_link_info = bpf_uprobe_multi_link_fill_link_info,
3194 };
3195 
uprobe_prog_run(struct bpf_uprobe * uprobe,unsigned long entry_ip,struct pt_regs * regs)3196 static int uprobe_prog_run(struct bpf_uprobe *uprobe,
3197 			   unsigned long entry_ip,
3198 			   struct pt_regs *regs)
3199 {
3200 	struct bpf_uprobe_multi_link *link = uprobe->link;
3201 	struct bpf_uprobe_multi_run_ctx run_ctx = {
3202 		.entry_ip = entry_ip,
3203 		.uprobe = uprobe,
3204 	};
3205 	struct bpf_prog *prog = link->link.prog;
3206 	bool sleepable = prog->sleepable;
3207 	struct bpf_run_ctx *old_run_ctx;
3208 	int err = 0;
3209 
3210 	if (link->task && !same_thread_group(current, link->task))
3211 		return 0;
3212 
3213 	if (sleepable)
3214 		rcu_read_lock_trace();
3215 	else
3216 		rcu_read_lock();
3217 
3218 	migrate_disable();
3219 
3220 	old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx);
3221 	err = bpf_prog_run(link->link.prog, regs);
3222 	bpf_reset_run_ctx(old_run_ctx);
3223 
3224 	migrate_enable();
3225 
3226 	if (sleepable)
3227 		rcu_read_unlock_trace();
3228 	else
3229 		rcu_read_unlock();
3230 	return err;
3231 }
3232 
3233 static bool
uprobe_multi_link_filter(struct uprobe_consumer * con,struct mm_struct * mm)3234 uprobe_multi_link_filter(struct uprobe_consumer *con, struct mm_struct *mm)
3235 {
3236 	struct bpf_uprobe *uprobe;
3237 
3238 	uprobe = container_of(con, struct bpf_uprobe, consumer);
3239 	return uprobe->link->task->mm == mm;
3240 }
3241 
3242 static int
uprobe_multi_link_handler(struct uprobe_consumer * con,struct pt_regs * regs)3243 uprobe_multi_link_handler(struct uprobe_consumer *con, struct pt_regs *regs)
3244 {
3245 	struct bpf_uprobe *uprobe;
3246 
3247 	uprobe = container_of(con, struct bpf_uprobe, consumer);
3248 	return uprobe_prog_run(uprobe, instruction_pointer(regs), regs);
3249 }
3250 
3251 static int
uprobe_multi_link_ret_handler(struct uprobe_consumer * con,unsigned long func,struct pt_regs * regs)3252 uprobe_multi_link_ret_handler(struct uprobe_consumer *con, unsigned long func, struct pt_regs *regs)
3253 {
3254 	struct bpf_uprobe *uprobe;
3255 
3256 	uprobe = container_of(con, struct bpf_uprobe, consumer);
3257 	return uprobe_prog_run(uprobe, func, regs);
3258 }
3259 
bpf_uprobe_multi_entry_ip(struct bpf_run_ctx * ctx)3260 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
3261 {
3262 	struct bpf_uprobe_multi_run_ctx *run_ctx;
3263 
3264 	run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx, run_ctx);
3265 	return run_ctx->entry_ip;
3266 }
3267 
bpf_uprobe_multi_cookie(struct bpf_run_ctx * ctx)3268 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx)
3269 {
3270 	struct bpf_uprobe_multi_run_ctx *run_ctx;
3271 
3272 	run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx, run_ctx);
3273 	return run_ctx->uprobe->cookie;
3274 }
3275 
bpf_uprobe_multi_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)3276 int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
3277 {
3278 	struct bpf_uprobe_multi_link *link = NULL;
3279 	unsigned long __user *uref_ctr_offsets;
3280 	struct bpf_link_primer link_primer;
3281 	struct bpf_uprobe *uprobes = NULL;
3282 	struct task_struct *task = NULL;
3283 	unsigned long __user *uoffsets;
3284 	u64 __user *ucookies;
3285 	void __user *upath;
3286 	u32 flags, cnt, i;
3287 	struct path path;
3288 	char *name;
3289 	pid_t pid;
3290 	int err;
3291 
3292 	/* no support for 32bit archs yet */
3293 	if (sizeof(u64) != sizeof(void *))
3294 		return -EOPNOTSUPP;
3295 
3296 	if (prog->expected_attach_type != BPF_TRACE_UPROBE_MULTI)
3297 		return -EINVAL;
3298 
3299 	flags = attr->link_create.uprobe_multi.flags;
3300 	if (flags & ~BPF_F_UPROBE_MULTI_RETURN)
3301 		return -EINVAL;
3302 
3303 	/*
3304 	 * path, offsets and cnt are mandatory,
3305 	 * ref_ctr_offsets and cookies are optional
3306 	 */
3307 	upath = u64_to_user_ptr(attr->link_create.uprobe_multi.path);
3308 	uoffsets = u64_to_user_ptr(attr->link_create.uprobe_multi.offsets);
3309 	cnt = attr->link_create.uprobe_multi.cnt;
3310 	pid = attr->link_create.uprobe_multi.pid;
3311 
3312 	if (!upath || !uoffsets || !cnt || pid < 0)
3313 		return -EINVAL;
3314 	if (cnt > MAX_UPROBE_MULTI_CNT)
3315 		return -E2BIG;
3316 
3317 	uref_ctr_offsets = u64_to_user_ptr(attr->link_create.uprobe_multi.ref_ctr_offsets);
3318 	ucookies = u64_to_user_ptr(attr->link_create.uprobe_multi.cookies);
3319 
3320 	name = strndup_user(upath, PATH_MAX);
3321 	if (IS_ERR(name)) {
3322 		err = PTR_ERR(name);
3323 		return err;
3324 	}
3325 
3326 	err = kern_path(name, LOOKUP_FOLLOW, &path);
3327 	kfree(name);
3328 	if (err)
3329 		return err;
3330 
3331 	if (!d_is_reg(path.dentry)) {
3332 		err = -EBADF;
3333 		goto error_path_put;
3334 	}
3335 
3336 	if (pid) {
3337 		task = get_pid_task(find_vpid(pid), PIDTYPE_TGID);
3338 		if (!task) {
3339 			err = -ESRCH;
3340 			goto error_path_put;
3341 		}
3342 	}
3343 
3344 	err = -ENOMEM;
3345 
3346 	link = kzalloc(sizeof(*link), GFP_KERNEL);
3347 	uprobes = kvcalloc(cnt, sizeof(*uprobes), GFP_KERNEL);
3348 
3349 	if (!uprobes || !link)
3350 		goto error_free;
3351 
3352 	for (i = 0; i < cnt; i++) {
3353 		if (__get_user(uprobes[i].offset, uoffsets + i)) {
3354 			err = -EFAULT;
3355 			goto error_free;
3356 		}
3357 		if (uprobes[i].offset < 0) {
3358 			err = -EINVAL;
3359 			goto error_free;
3360 		}
3361 		if (uref_ctr_offsets && __get_user(uprobes[i].ref_ctr_offset, uref_ctr_offsets + i)) {
3362 			err = -EFAULT;
3363 			goto error_free;
3364 		}
3365 		if (ucookies && __get_user(uprobes[i].cookie, ucookies + i)) {
3366 			err = -EFAULT;
3367 			goto error_free;
3368 		}
3369 
3370 		uprobes[i].link = link;
3371 
3372 		if (flags & BPF_F_UPROBE_MULTI_RETURN)
3373 			uprobes[i].consumer.ret_handler = uprobe_multi_link_ret_handler;
3374 		else
3375 			uprobes[i].consumer.handler = uprobe_multi_link_handler;
3376 
3377 		if (pid)
3378 			uprobes[i].consumer.filter = uprobe_multi_link_filter;
3379 	}
3380 
3381 	link->cnt = cnt;
3382 	link->uprobes = uprobes;
3383 	link->path = path;
3384 	link->task = task;
3385 	link->flags = flags;
3386 
3387 	bpf_link_init(&link->link, BPF_LINK_TYPE_UPROBE_MULTI,
3388 		      &bpf_uprobe_multi_link_lops, prog);
3389 
3390 	for (i = 0; i < cnt; i++) {
3391 		uprobes[i].uprobe = uprobe_register(d_real_inode(link->path.dentry),
3392 						    uprobes[i].offset,
3393 						    uprobes[i].ref_ctr_offset,
3394 						    &uprobes[i].consumer);
3395 		if (IS_ERR(uprobes[i].uprobe)) {
3396 			err = PTR_ERR(uprobes[i].uprobe);
3397 			link->cnt = i;
3398 			goto error_unregister;
3399 		}
3400 	}
3401 
3402 	err = bpf_link_prime(&link->link, &link_primer);
3403 	if (err)
3404 		goto error_unregister;
3405 
3406 	return bpf_link_settle(&link_primer);
3407 
3408 error_unregister:
3409 	bpf_uprobe_unregister(uprobes, link->cnt);
3410 
3411 error_free:
3412 	kvfree(uprobes);
3413 	kfree(link);
3414 	if (task)
3415 		put_task_struct(task);
3416 error_path_put:
3417 	path_put(&path);
3418 	return err;
3419 }
3420 #else /* !CONFIG_UPROBES */
bpf_uprobe_multi_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)3421 int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
3422 {
3423 	return -EOPNOTSUPP;
3424 }
bpf_uprobe_multi_cookie(struct bpf_run_ctx * ctx)3425 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx)
3426 {
3427 	return 0;
3428 }
bpf_uprobe_multi_entry_ip(struct bpf_run_ctx * ctx)3429 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
3430 {
3431 	return 0;
3432 }
3433 #endif /* CONFIG_UPROBES */
3434 
3435 __bpf_kfunc_start_defs();
3436 
bpf_session_is_return(void)3437 __bpf_kfunc bool bpf_session_is_return(void)
3438 {
3439 	struct bpf_session_run_ctx *session_ctx;
3440 
3441 	session_ctx = container_of(current->bpf_ctx, struct bpf_session_run_ctx, run_ctx);
3442 	return session_ctx->is_return;
3443 }
3444 
bpf_session_cookie(void)3445 __bpf_kfunc __u64 *bpf_session_cookie(void)
3446 {
3447 	struct bpf_session_run_ctx *session_ctx;
3448 
3449 	session_ctx = container_of(current->bpf_ctx, struct bpf_session_run_ctx, run_ctx);
3450 	return session_ctx->data;
3451 }
3452 
3453 __bpf_kfunc_end_defs();
3454 
3455 BTF_KFUNCS_START(kprobe_multi_kfunc_set_ids)
BTF_ID_FLAGS(func,bpf_session_is_return)3456 BTF_ID_FLAGS(func, bpf_session_is_return)
3457 BTF_ID_FLAGS(func, bpf_session_cookie)
3458 BTF_KFUNCS_END(kprobe_multi_kfunc_set_ids)
3459 
3460 static int bpf_kprobe_multi_filter(const struct bpf_prog *prog, u32 kfunc_id)
3461 {
3462 	if (!btf_id_set8_contains(&kprobe_multi_kfunc_set_ids, kfunc_id))
3463 		return 0;
3464 
3465 	if (!is_kprobe_session(prog))
3466 		return -EACCES;
3467 
3468 	return 0;
3469 }
3470 
3471 static const struct btf_kfunc_id_set bpf_kprobe_multi_kfunc_set = {
3472 	.owner = THIS_MODULE,
3473 	.set = &kprobe_multi_kfunc_set_ids,
3474 	.filter = bpf_kprobe_multi_filter,
3475 };
3476 
bpf_kprobe_multi_kfuncs_init(void)3477 static int __init bpf_kprobe_multi_kfuncs_init(void)
3478 {
3479 	return register_btf_kfunc_id_set(BPF_PROG_TYPE_KPROBE, &bpf_kprobe_multi_kfunc_set);
3480 }
3481 
3482 late_initcall(bpf_kprobe_multi_kfuncs_init);
3483