xref: /openbmc/linux/kernel/trace/bpf_trace.c (revision 39a143a2)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2011-2015 PLUMgrid, http://plumgrid.com
3  * Copyright (c) 2016 Facebook
4  */
5 #include <linux/kernel.h>
6 #include <linux/types.h>
7 #include <linux/slab.h>
8 #include <linux/bpf.h>
9 #include <linux/bpf_verifier.h>
10 #include <linux/bpf_perf_event.h>
11 #include <linux/btf.h>
12 #include <linux/filter.h>
13 #include <linux/uaccess.h>
14 #include <linux/ctype.h>
15 #include <linux/kprobes.h>
16 #include <linux/spinlock.h>
17 #include <linux/syscalls.h>
18 #include <linux/error-injection.h>
19 #include <linux/btf_ids.h>
20 #include <linux/bpf_lsm.h>
21 #include <linux/fprobe.h>
22 #include <linux/bsearch.h>
23 #include <linux/sort.h>
24 #include <linux/key.h>
25 #include <linux/verification.h>
26 #include <linux/namei.h>
27 
28 #include <net/bpf_sk_storage.h>
29 
30 #include <uapi/linux/bpf.h>
31 #include <uapi/linux/btf.h>
32 
33 #include <asm/tlb.h>
34 
35 #include "trace_probe.h"
36 #include "trace.h"
37 
38 #define CREATE_TRACE_POINTS
39 #include "bpf_trace.h"
40 
41 #define bpf_event_rcu_dereference(p)					\
42 	rcu_dereference_protected(p, lockdep_is_held(&bpf_event_mutex))
43 
44 #define MAX_UPROBE_MULTI_CNT (1U << 20)
45 #define MAX_KPROBE_MULTI_CNT (1U << 20)
46 
47 #ifdef CONFIG_MODULES
48 struct bpf_trace_module {
49 	struct module *module;
50 	struct list_head list;
51 };
52 
53 static LIST_HEAD(bpf_trace_modules);
54 static DEFINE_MUTEX(bpf_module_mutex);
55 
bpf_get_raw_tracepoint_module(const char * name)56 static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name)
57 {
58 	struct bpf_raw_event_map *btp, *ret = NULL;
59 	struct bpf_trace_module *btm;
60 	unsigned int i;
61 
62 	mutex_lock(&bpf_module_mutex);
63 	list_for_each_entry(btm, &bpf_trace_modules, list) {
64 		for (i = 0; i < btm->module->num_bpf_raw_events; ++i) {
65 			btp = &btm->module->bpf_raw_events[i];
66 			if (!strcmp(btp->tp->name, name)) {
67 				if (try_module_get(btm->module))
68 					ret = btp;
69 				goto out;
70 			}
71 		}
72 	}
73 out:
74 	mutex_unlock(&bpf_module_mutex);
75 	return ret;
76 }
77 #else
bpf_get_raw_tracepoint_module(const char * name)78 static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name)
79 {
80 	return NULL;
81 }
82 #endif /* CONFIG_MODULES */
83 
84 u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
85 u64 bpf_get_stack(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
86 
87 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size,
88 				  u64 flags, const struct btf **btf,
89 				  s32 *btf_id);
90 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx);
91 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx);
92 
93 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx);
94 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx);
95 
96 /**
97  * trace_call_bpf - invoke BPF program
98  * @call: tracepoint event
99  * @ctx: opaque context pointer
100  *
101  * kprobe handlers execute BPF programs via this helper.
102  * Can be used from static tracepoints in the future.
103  *
104  * Return: BPF programs always return an integer which is interpreted by
105  * kprobe handler as:
106  * 0 - return from kprobe (event is filtered out)
107  * 1 - store kprobe event into ring buffer
108  * Other values are reserved and currently alias to 1
109  */
trace_call_bpf(struct trace_event_call * call,void * ctx)110 unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx)
111 {
112 	unsigned int ret;
113 
114 	cant_sleep();
115 
116 	if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) {
117 		/*
118 		 * since some bpf program is already running on this cpu,
119 		 * don't call into another bpf program (same or different)
120 		 * and don't send kprobe event into ring-buffer,
121 		 * so return zero here
122 		 */
123 		ret = 0;
124 		goto out;
125 	}
126 
127 	/*
128 	 * Instead of moving rcu_read_lock/rcu_dereference/rcu_read_unlock
129 	 * to all call sites, we did a bpf_prog_array_valid() there to check
130 	 * whether call->prog_array is empty or not, which is
131 	 * a heuristic to speed up execution.
132 	 *
133 	 * If bpf_prog_array_valid() fetched prog_array was
134 	 * non-NULL, we go into trace_call_bpf() and do the actual
135 	 * proper rcu_dereference() under RCU lock.
136 	 * If it turns out that prog_array is NULL then, we bail out.
137 	 * For the opposite, if the bpf_prog_array_valid() fetched pointer
138 	 * was NULL, you'll skip the prog_array with the risk of missing
139 	 * out of events when it was updated in between this and the
140 	 * rcu_dereference() which is accepted risk.
141 	 */
142 	rcu_read_lock();
143 	ret = bpf_prog_run_array(rcu_dereference(call->prog_array),
144 				 ctx, bpf_prog_run);
145 	rcu_read_unlock();
146 
147  out:
148 	__this_cpu_dec(bpf_prog_active);
149 
150 	return ret;
151 }
152 
153 #ifdef CONFIG_BPF_KPROBE_OVERRIDE
BPF_CALL_2(bpf_override_return,struct pt_regs *,regs,unsigned long,rc)154 BPF_CALL_2(bpf_override_return, struct pt_regs *, regs, unsigned long, rc)
155 {
156 	regs_set_return_value(regs, rc);
157 	override_function_with_return(regs);
158 	return 0;
159 }
160 
161 static const struct bpf_func_proto bpf_override_return_proto = {
162 	.func		= bpf_override_return,
163 	.gpl_only	= true,
164 	.ret_type	= RET_INTEGER,
165 	.arg1_type	= ARG_PTR_TO_CTX,
166 	.arg2_type	= ARG_ANYTHING,
167 };
168 #endif
169 
170 static __always_inline int
bpf_probe_read_user_common(void * dst,u32 size,const void __user * unsafe_ptr)171 bpf_probe_read_user_common(void *dst, u32 size, const void __user *unsafe_ptr)
172 {
173 	int ret;
174 
175 	ret = copy_from_user_nofault(dst, unsafe_ptr, size);
176 	if (unlikely(ret < 0))
177 		memset(dst, 0, size);
178 	return ret;
179 }
180 
BPF_CALL_3(bpf_probe_read_user,void *,dst,u32,size,const void __user *,unsafe_ptr)181 BPF_CALL_3(bpf_probe_read_user, void *, dst, u32, size,
182 	   const void __user *, unsafe_ptr)
183 {
184 	return bpf_probe_read_user_common(dst, size, unsafe_ptr);
185 }
186 
187 const struct bpf_func_proto bpf_probe_read_user_proto = {
188 	.func		= bpf_probe_read_user,
189 	.gpl_only	= true,
190 	.ret_type	= RET_INTEGER,
191 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
192 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
193 	.arg3_type	= ARG_ANYTHING,
194 };
195 
196 static __always_inline int
bpf_probe_read_user_str_common(void * dst,u32 size,const void __user * unsafe_ptr)197 bpf_probe_read_user_str_common(void *dst, u32 size,
198 			       const void __user *unsafe_ptr)
199 {
200 	int ret;
201 
202 	/*
203 	 * NB: We rely on strncpy_from_user() not copying junk past the NUL
204 	 * terminator into `dst`.
205 	 *
206 	 * strncpy_from_user() does long-sized strides in the fast path. If the
207 	 * strncpy does not mask out the bytes after the NUL in `unsafe_ptr`,
208 	 * then there could be junk after the NUL in `dst`. If user takes `dst`
209 	 * and keys a hash map with it, then semantically identical strings can
210 	 * occupy multiple entries in the map.
211 	 */
212 	ret = strncpy_from_user_nofault(dst, unsafe_ptr, size);
213 	if (unlikely(ret < 0))
214 		memset(dst, 0, size);
215 	return ret;
216 }
217 
BPF_CALL_3(bpf_probe_read_user_str,void *,dst,u32,size,const void __user *,unsafe_ptr)218 BPF_CALL_3(bpf_probe_read_user_str, void *, dst, u32, size,
219 	   const void __user *, unsafe_ptr)
220 {
221 	return bpf_probe_read_user_str_common(dst, size, unsafe_ptr);
222 }
223 
224 const struct bpf_func_proto bpf_probe_read_user_str_proto = {
225 	.func		= bpf_probe_read_user_str,
226 	.gpl_only	= true,
227 	.ret_type	= RET_INTEGER,
228 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
229 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
230 	.arg3_type	= ARG_ANYTHING,
231 };
232 
BPF_CALL_3(bpf_probe_read_kernel,void *,dst,u32,size,const void *,unsafe_ptr)233 BPF_CALL_3(bpf_probe_read_kernel, void *, dst, u32, size,
234 	   const void *, unsafe_ptr)
235 {
236 	return bpf_probe_read_kernel_common(dst, size, unsafe_ptr);
237 }
238 
239 const struct bpf_func_proto bpf_probe_read_kernel_proto = {
240 	.func		= bpf_probe_read_kernel,
241 	.gpl_only	= true,
242 	.ret_type	= RET_INTEGER,
243 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
244 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
245 	.arg3_type	= ARG_ANYTHING,
246 };
247 
248 static __always_inline int
bpf_probe_read_kernel_str_common(void * dst,u32 size,const void * unsafe_ptr)249 bpf_probe_read_kernel_str_common(void *dst, u32 size, const void *unsafe_ptr)
250 {
251 	int ret;
252 
253 	/*
254 	 * The strncpy_from_kernel_nofault() call will likely not fill the
255 	 * entire buffer, but that's okay in this circumstance as we're probing
256 	 * arbitrary memory anyway similar to bpf_probe_read_*() and might
257 	 * as well probe the stack. Thus, memory is explicitly cleared
258 	 * only in error case, so that improper users ignoring return
259 	 * code altogether don't copy garbage; otherwise length of string
260 	 * is returned that can be used for bpf_perf_event_output() et al.
261 	 */
262 	ret = strncpy_from_kernel_nofault(dst, unsafe_ptr, size);
263 	if (unlikely(ret < 0))
264 		memset(dst, 0, size);
265 	return ret;
266 }
267 
BPF_CALL_3(bpf_probe_read_kernel_str,void *,dst,u32,size,const void *,unsafe_ptr)268 BPF_CALL_3(bpf_probe_read_kernel_str, void *, dst, u32, size,
269 	   const void *, unsafe_ptr)
270 {
271 	return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr);
272 }
273 
274 const struct bpf_func_proto bpf_probe_read_kernel_str_proto = {
275 	.func		= bpf_probe_read_kernel_str,
276 	.gpl_only	= true,
277 	.ret_type	= RET_INTEGER,
278 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
279 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
280 	.arg3_type	= ARG_ANYTHING,
281 };
282 
283 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
BPF_CALL_3(bpf_probe_read_compat,void *,dst,u32,size,const void *,unsafe_ptr)284 BPF_CALL_3(bpf_probe_read_compat, void *, dst, u32, size,
285 	   const void *, unsafe_ptr)
286 {
287 	if ((unsigned long)unsafe_ptr < TASK_SIZE) {
288 		return bpf_probe_read_user_common(dst, size,
289 				(__force void __user *)unsafe_ptr);
290 	}
291 	return bpf_probe_read_kernel_common(dst, size, unsafe_ptr);
292 }
293 
294 static const struct bpf_func_proto bpf_probe_read_compat_proto = {
295 	.func		= bpf_probe_read_compat,
296 	.gpl_only	= true,
297 	.ret_type	= RET_INTEGER,
298 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
299 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
300 	.arg3_type	= ARG_ANYTHING,
301 };
302 
BPF_CALL_3(bpf_probe_read_compat_str,void *,dst,u32,size,const void *,unsafe_ptr)303 BPF_CALL_3(bpf_probe_read_compat_str, void *, dst, u32, size,
304 	   const void *, unsafe_ptr)
305 {
306 	if ((unsigned long)unsafe_ptr < TASK_SIZE) {
307 		return bpf_probe_read_user_str_common(dst, size,
308 				(__force void __user *)unsafe_ptr);
309 	}
310 	return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr);
311 }
312 
313 static const struct bpf_func_proto bpf_probe_read_compat_str_proto = {
314 	.func		= bpf_probe_read_compat_str,
315 	.gpl_only	= true,
316 	.ret_type	= RET_INTEGER,
317 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
318 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
319 	.arg3_type	= ARG_ANYTHING,
320 };
321 #endif /* CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE */
322 
BPF_CALL_3(bpf_probe_write_user,void __user *,unsafe_ptr,const void *,src,u32,size)323 BPF_CALL_3(bpf_probe_write_user, void __user *, unsafe_ptr, const void *, src,
324 	   u32, size)
325 {
326 	/*
327 	 * Ensure we're in user context which is safe for the helper to
328 	 * run. This helper has no business in a kthread.
329 	 *
330 	 * access_ok() should prevent writing to non-user memory, but in
331 	 * some situations (nommu, temporary switch, etc) access_ok() does
332 	 * not provide enough validation, hence the check on KERNEL_DS.
333 	 *
334 	 * nmi_uaccess_okay() ensures the probe is not run in an interim
335 	 * state, when the task or mm are switched. This is specifically
336 	 * required to prevent the use of temporary mm.
337 	 */
338 
339 	if (unlikely(in_interrupt() ||
340 		     current->flags & (PF_KTHREAD | PF_EXITING)))
341 		return -EPERM;
342 	if (unlikely(!nmi_uaccess_okay()))
343 		return -EPERM;
344 
345 	return copy_to_user_nofault(unsafe_ptr, src, size);
346 }
347 
348 static const struct bpf_func_proto bpf_probe_write_user_proto = {
349 	.func		= bpf_probe_write_user,
350 	.gpl_only	= true,
351 	.ret_type	= RET_INTEGER,
352 	.arg1_type	= ARG_ANYTHING,
353 	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
354 	.arg3_type	= ARG_CONST_SIZE,
355 };
356 
bpf_get_probe_write_proto(void)357 static const struct bpf_func_proto *bpf_get_probe_write_proto(void)
358 {
359 	if (!capable(CAP_SYS_ADMIN))
360 		return NULL;
361 
362 	pr_warn_ratelimited("%s[%d] is installing a program with bpf_probe_write_user helper that may corrupt user memory!",
363 			    current->comm, task_pid_nr(current));
364 
365 	return &bpf_probe_write_user_proto;
366 }
367 
368 #define MAX_TRACE_PRINTK_VARARGS	3
369 #define BPF_TRACE_PRINTK_SIZE		1024
370 
BPF_CALL_5(bpf_trace_printk,char *,fmt,u32,fmt_size,u64,arg1,u64,arg2,u64,arg3)371 BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1,
372 	   u64, arg2, u64, arg3)
373 {
374 	u64 args[MAX_TRACE_PRINTK_VARARGS] = { arg1, arg2, arg3 };
375 	struct bpf_bprintf_data data = {
376 		.get_bin_args	= true,
377 		.get_buf	= true,
378 	};
379 	int ret;
380 
381 	ret = bpf_bprintf_prepare(fmt, fmt_size, args,
382 				  MAX_TRACE_PRINTK_VARARGS, &data);
383 	if (ret < 0)
384 		return ret;
385 
386 	ret = bstr_printf(data.buf, MAX_BPRINTF_BUF, fmt, data.bin_args);
387 
388 	trace_bpf_trace_printk(data.buf);
389 
390 	bpf_bprintf_cleanup(&data);
391 
392 	return ret;
393 }
394 
395 static const struct bpf_func_proto bpf_trace_printk_proto = {
396 	.func		= bpf_trace_printk,
397 	.gpl_only	= true,
398 	.ret_type	= RET_INTEGER,
399 	.arg1_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
400 	.arg2_type	= ARG_CONST_SIZE,
401 };
402 
__set_printk_clr_event(void)403 static void __set_printk_clr_event(void)
404 {
405 	/*
406 	 * This program might be calling bpf_trace_printk,
407 	 * so enable the associated bpf_trace/bpf_trace_printk event.
408 	 * Repeat this each time as it is possible a user has
409 	 * disabled bpf_trace_printk events.  By loading a program
410 	 * calling bpf_trace_printk() however the user has expressed
411 	 * the intent to see such events.
412 	 */
413 	if (trace_set_clr_event("bpf_trace", "bpf_trace_printk", 1))
414 		pr_warn_ratelimited("could not enable bpf_trace_printk events");
415 }
416 
bpf_get_trace_printk_proto(void)417 const struct bpf_func_proto *bpf_get_trace_printk_proto(void)
418 {
419 	__set_printk_clr_event();
420 	return &bpf_trace_printk_proto;
421 }
422 
BPF_CALL_4(bpf_trace_vprintk,char *,fmt,u32,fmt_size,const void *,args,u32,data_len)423 BPF_CALL_4(bpf_trace_vprintk, char *, fmt, u32, fmt_size, const void *, args,
424 	   u32, data_len)
425 {
426 	struct bpf_bprintf_data data = {
427 		.get_bin_args	= true,
428 		.get_buf	= true,
429 	};
430 	int ret, num_args;
431 
432 	if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 ||
433 	    (data_len && !args))
434 		return -EINVAL;
435 	num_args = data_len / 8;
436 
437 	ret = bpf_bprintf_prepare(fmt, fmt_size, args, num_args, &data);
438 	if (ret < 0)
439 		return ret;
440 
441 	ret = bstr_printf(data.buf, MAX_BPRINTF_BUF, fmt, data.bin_args);
442 
443 	trace_bpf_trace_printk(data.buf);
444 
445 	bpf_bprintf_cleanup(&data);
446 
447 	return ret;
448 }
449 
450 static const struct bpf_func_proto bpf_trace_vprintk_proto = {
451 	.func		= bpf_trace_vprintk,
452 	.gpl_only	= true,
453 	.ret_type	= RET_INTEGER,
454 	.arg1_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
455 	.arg2_type	= ARG_CONST_SIZE,
456 	.arg3_type	= ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY,
457 	.arg4_type	= ARG_CONST_SIZE_OR_ZERO,
458 };
459 
bpf_get_trace_vprintk_proto(void)460 const struct bpf_func_proto *bpf_get_trace_vprintk_proto(void)
461 {
462 	__set_printk_clr_event();
463 	return &bpf_trace_vprintk_proto;
464 }
465 
BPF_CALL_5(bpf_seq_printf,struct seq_file *,m,char *,fmt,u32,fmt_size,const void *,args,u32,data_len)466 BPF_CALL_5(bpf_seq_printf, struct seq_file *, m, char *, fmt, u32, fmt_size,
467 	   const void *, args, u32, data_len)
468 {
469 	struct bpf_bprintf_data data = {
470 		.get_bin_args	= true,
471 	};
472 	int err, num_args;
473 
474 	if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 ||
475 	    (data_len && !args))
476 		return -EINVAL;
477 	num_args = data_len / 8;
478 
479 	err = bpf_bprintf_prepare(fmt, fmt_size, args, num_args, &data);
480 	if (err < 0)
481 		return err;
482 
483 	seq_bprintf(m, fmt, data.bin_args);
484 
485 	bpf_bprintf_cleanup(&data);
486 
487 	return seq_has_overflowed(m) ? -EOVERFLOW : 0;
488 }
489 
490 BTF_ID_LIST_SINGLE(btf_seq_file_ids, struct, seq_file)
491 
492 static const struct bpf_func_proto bpf_seq_printf_proto = {
493 	.func		= bpf_seq_printf,
494 	.gpl_only	= true,
495 	.ret_type	= RET_INTEGER,
496 	.arg1_type	= ARG_PTR_TO_BTF_ID,
497 	.arg1_btf_id	= &btf_seq_file_ids[0],
498 	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
499 	.arg3_type	= ARG_CONST_SIZE,
500 	.arg4_type      = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY,
501 	.arg5_type      = ARG_CONST_SIZE_OR_ZERO,
502 };
503 
BPF_CALL_3(bpf_seq_write,struct seq_file *,m,const void *,data,u32,len)504 BPF_CALL_3(bpf_seq_write, struct seq_file *, m, const void *, data, u32, len)
505 {
506 	return seq_write(m, data, len) ? -EOVERFLOW : 0;
507 }
508 
509 static const struct bpf_func_proto bpf_seq_write_proto = {
510 	.func		= bpf_seq_write,
511 	.gpl_only	= true,
512 	.ret_type	= RET_INTEGER,
513 	.arg1_type	= ARG_PTR_TO_BTF_ID,
514 	.arg1_btf_id	= &btf_seq_file_ids[0],
515 	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
516 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
517 };
518 
BPF_CALL_4(bpf_seq_printf_btf,struct seq_file *,m,struct btf_ptr *,ptr,u32,btf_ptr_size,u64,flags)519 BPF_CALL_4(bpf_seq_printf_btf, struct seq_file *, m, struct btf_ptr *, ptr,
520 	   u32, btf_ptr_size, u64, flags)
521 {
522 	const struct btf *btf;
523 	s32 btf_id;
524 	int ret;
525 
526 	ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id);
527 	if (ret)
528 		return ret;
529 
530 	return btf_type_seq_show_flags(btf, btf_id, ptr->ptr, m, flags);
531 }
532 
533 static const struct bpf_func_proto bpf_seq_printf_btf_proto = {
534 	.func		= bpf_seq_printf_btf,
535 	.gpl_only	= true,
536 	.ret_type	= RET_INTEGER,
537 	.arg1_type	= ARG_PTR_TO_BTF_ID,
538 	.arg1_btf_id	= &btf_seq_file_ids[0],
539 	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
540 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
541 	.arg4_type	= ARG_ANYTHING,
542 };
543 
544 static __always_inline int
get_map_perf_counter(struct bpf_map * map,u64 flags,u64 * value,u64 * enabled,u64 * running)545 get_map_perf_counter(struct bpf_map *map, u64 flags,
546 		     u64 *value, u64 *enabled, u64 *running)
547 {
548 	struct bpf_array *array = container_of(map, struct bpf_array, map);
549 	unsigned int cpu = smp_processor_id();
550 	u64 index = flags & BPF_F_INDEX_MASK;
551 	struct bpf_event_entry *ee;
552 
553 	if (unlikely(flags & ~(BPF_F_INDEX_MASK)))
554 		return -EINVAL;
555 	if (index == BPF_F_CURRENT_CPU)
556 		index = cpu;
557 	if (unlikely(index >= array->map.max_entries))
558 		return -E2BIG;
559 
560 	ee = READ_ONCE(array->ptrs[index]);
561 	if (!ee)
562 		return -ENOENT;
563 
564 	return perf_event_read_local(ee->event, value, enabled, running);
565 }
566 
BPF_CALL_2(bpf_perf_event_read,struct bpf_map *,map,u64,flags)567 BPF_CALL_2(bpf_perf_event_read, struct bpf_map *, map, u64, flags)
568 {
569 	u64 value = 0;
570 	int err;
571 
572 	err = get_map_perf_counter(map, flags, &value, NULL, NULL);
573 	/*
574 	 * this api is ugly since we miss [-22..-2] range of valid
575 	 * counter values, but that's uapi
576 	 */
577 	if (err)
578 		return err;
579 	return value;
580 }
581 
582 static const struct bpf_func_proto bpf_perf_event_read_proto = {
583 	.func		= bpf_perf_event_read,
584 	.gpl_only	= true,
585 	.ret_type	= RET_INTEGER,
586 	.arg1_type	= ARG_CONST_MAP_PTR,
587 	.arg2_type	= ARG_ANYTHING,
588 };
589 
BPF_CALL_4(bpf_perf_event_read_value,struct bpf_map *,map,u64,flags,struct bpf_perf_event_value *,buf,u32,size)590 BPF_CALL_4(bpf_perf_event_read_value, struct bpf_map *, map, u64, flags,
591 	   struct bpf_perf_event_value *, buf, u32, size)
592 {
593 	int err = -EINVAL;
594 
595 	if (unlikely(size != sizeof(struct bpf_perf_event_value)))
596 		goto clear;
597 	err = get_map_perf_counter(map, flags, &buf->counter, &buf->enabled,
598 				   &buf->running);
599 	if (unlikely(err))
600 		goto clear;
601 	return 0;
602 clear:
603 	memset(buf, 0, size);
604 	return err;
605 }
606 
607 static const struct bpf_func_proto bpf_perf_event_read_value_proto = {
608 	.func		= bpf_perf_event_read_value,
609 	.gpl_only	= true,
610 	.ret_type	= RET_INTEGER,
611 	.arg1_type	= ARG_CONST_MAP_PTR,
612 	.arg2_type	= ARG_ANYTHING,
613 	.arg3_type	= ARG_PTR_TO_UNINIT_MEM,
614 	.arg4_type	= ARG_CONST_SIZE,
615 };
616 
617 static __always_inline u64
__bpf_perf_event_output(struct pt_regs * regs,struct bpf_map * map,u64 flags,struct perf_sample_data * sd)618 __bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map,
619 			u64 flags, struct perf_sample_data *sd)
620 {
621 	struct bpf_array *array = container_of(map, struct bpf_array, map);
622 	unsigned int cpu = smp_processor_id();
623 	u64 index = flags & BPF_F_INDEX_MASK;
624 	struct bpf_event_entry *ee;
625 	struct perf_event *event;
626 
627 	if (index == BPF_F_CURRENT_CPU)
628 		index = cpu;
629 	if (unlikely(index >= array->map.max_entries))
630 		return -E2BIG;
631 
632 	ee = READ_ONCE(array->ptrs[index]);
633 	if (!ee)
634 		return -ENOENT;
635 
636 	event = ee->event;
637 	if (unlikely(event->attr.type != PERF_TYPE_SOFTWARE ||
638 		     event->attr.config != PERF_COUNT_SW_BPF_OUTPUT))
639 		return -EINVAL;
640 
641 	if (unlikely(event->oncpu != cpu))
642 		return -EOPNOTSUPP;
643 
644 	return perf_event_output(event, sd, regs);
645 }
646 
647 /*
648  * Support executing tracepoints in normal, irq, and nmi context that each call
649  * bpf_perf_event_output
650  */
651 struct bpf_trace_sample_data {
652 	struct perf_sample_data sds[3];
653 };
654 
655 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_trace_sds);
656 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)657 BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map,
658 	   u64, flags, void *, data, u64, size)
659 {
660 	struct bpf_trace_sample_data *sds;
661 	struct perf_raw_record raw = {
662 		.frag = {
663 			.size = size,
664 			.data = data,
665 		},
666 	};
667 	struct perf_sample_data *sd;
668 	int nest_level, err;
669 
670 	preempt_disable();
671 	sds = this_cpu_ptr(&bpf_trace_sds);
672 	nest_level = this_cpu_inc_return(bpf_trace_nest_level);
673 
674 	if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(sds->sds))) {
675 		err = -EBUSY;
676 		goto out;
677 	}
678 
679 	sd = &sds->sds[nest_level - 1];
680 
681 	if (unlikely(flags & ~(BPF_F_INDEX_MASK))) {
682 		err = -EINVAL;
683 		goto out;
684 	}
685 
686 	perf_sample_data_init(sd, 0, 0);
687 	perf_sample_save_raw_data(sd, &raw);
688 
689 	err = __bpf_perf_event_output(regs, map, flags, sd);
690 out:
691 	this_cpu_dec(bpf_trace_nest_level);
692 	preempt_enable();
693 	return err;
694 }
695 
696 static const struct bpf_func_proto bpf_perf_event_output_proto = {
697 	.func		= bpf_perf_event_output,
698 	.gpl_only	= true,
699 	.ret_type	= RET_INTEGER,
700 	.arg1_type	= ARG_PTR_TO_CTX,
701 	.arg2_type	= ARG_CONST_MAP_PTR,
702 	.arg3_type	= ARG_ANYTHING,
703 	.arg4_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
704 	.arg5_type	= ARG_CONST_SIZE_OR_ZERO,
705 };
706 
707 static DEFINE_PER_CPU(int, bpf_event_output_nest_level);
708 struct bpf_nested_pt_regs {
709 	struct pt_regs regs[3];
710 };
711 static DEFINE_PER_CPU(struct bpf_nested_pt_regs, bpf_pt_regs);
712 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_misc_sds);
713 
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)714 u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
715 		     void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy)
716 {
717 	struct perf_raw_frag frag = {
718 		.copy		= ctx_copy,
719 		.size		= ctx_size,
720 		.data		= ctx,
721 	};
722 	struct perf_raw_record raw = {
723 		.frag = {
724 			{
725 				.next	= ctx_size ? &frag : NULL,
726 			},
727 			.size	= meta_size,
728 			.data	= meta,
729 		},
730 	};
731 	struct perf_sample_data *sd;
732 	struct pt_regs *regs;
733 	int nest_level;
734 	u64 ret;
735 
736 	preempt_disable();
737 	nest_level = this_cpu_inc_return(bpf_event_output_nest_level);
738 
739 	if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(bpf_misc_sds.sds))) {
740 		ret = -EBUSY;
741 		goto out;
742 	}
743 	sd = this_cpu_ptr(&bpf_misc_sds.sds[nest_level - 1]);
744 	regs = this_cpu_ptr(&bpf_pt_regs.regs[nest_level - 1]);
745 
746 	perf_fetch_caller_regs(regs);
747 	perf_sample_data_init(sd, 0, 0);
748 	perf_sample_save_raw_data(sd, &raw);
749 
750 	ret = __bpf_perf_event_output(regs, map, flags, sd);
751 out:
752 	this_cpu_dec(bpf_event_output_nest_level);
753 	preempt_enable();
754 	return ret;
755 }
756 
BPF_CALL_0(bpf_get_current_task)757 BPF_CALL_0(bpf_get_current_task)
758 {
759 	return (long) current;
760 }
761 
762 const struct bpf_func_proto bpf_get_current_task_proto = {
763 	.func		= bpf_get_current_task,
764 	.gpl_only	= true,
765 	.ret_type	= RET_INTEGER,
766 };
767 
BPF_CALL_0(bpf_get_current_task_btf)768 BPF_CALL_0(bpf_get_current_task_btf)
769 {
770 	return (unsigned long) current;
771 }
772 
773 const struct bpf_func_proto bpf_get_current_task_btf_proto = {
774 	.func		= bpf_get_current_task_btf,
775 	.gpl_only	= true,
776 	.ret_type	= RET_PTR_TO_BTF_ID_TRUSTED,
777 	.ret_btf_id	= &btf_tracing_ids[BTF_TRACING_TYPE_TASK],
778 };
779 
BPF_CALL_1(bpf_task_pt_regs,struct task_struct *,task)780 BPF_CALL_1(bpf_task_pt_regs, struct task_struct *, task)
781 {
782 	return (unsigned long) task_pt_regs(task);
783 }
784 
785 BTF_ID_LIST(bpf_task_pt_regs_ids)
786 BTF_ID(struct, pt_regs)
787 
788 const struct bpf_func_proto bpf_task_pt_regs_proto = {
789 	.func		= bpf_task_pt_regs,
790 	.gpl_only	= true,
791 	.arg1_type	= ARG_PTR_TO_BTF_ID,
792 	.arg1_btf_id	= &btf_tracing_ids[BTF_TRACING_TYPE_TASK],
793 	.ret_type	= RET_PTR_TO_BTF_ID,
794 	.ret_btf_id	= &bpf_task_pt_regs_ids[0],
795 };
796 
BPF_CALL_2(bpf_current_task_under_cgroup,struct bpf_map *,map,u32,idx)797 BPF_CALL_2(bpf_current_task_under_cgroup, struct bpf_map *, map, u32, idx)
798 {
799 	struct bpf_array *array = container_of(map, struct bpf_array, map);
800 	struct cgroup *cgrp;
801 
802 	if (unlikely(idx >= array->map.max_entries))
803 		return -E2BIG;
804 
805 	cgrp = READ_ONCE(array->ptrs[idx]);
806 	if (unlikely(!cgrp))
807 		return -EAGAIN;
808 
809 	return task_under_cgroup_hierarchy(current, cgrp);
810 }
811 
812 static const struct bpf_func_proto bpf_current_task_under_cgroup_proto = {
813 	.func           = bpf_current_task_under_cgroup,
814 	.gpl_only       = false,
815 	.ret_type       = RET_INTEGER,
816 	.arg1_type      = ARG_CONST_MAP_PTR,
817 	.arg2_type      = ARG_ANYTHING,
818 };
819 
820 struct send_signal_irq_work {
821 	struct irq_work irq_work;
822 	struct task_struct *task;
823 	u32 sig;
824 	enum pid_type type;
825 };
826 
827 static DEFINE_PER_CPU(struct send_signal_irq_work, send_signal_work);
828 
do_bpf_send_signal(struct irq_work * entry)829 static void do_bpf_send_signal(struct irq_work *entry)
830 {
831 	struct send_signal_irq_work *work;
832 
833 	work = container_of(entry, struct send_signal_irq_work, irq_work);
834 	group_send_sig_info(work->sig, SEND_SIG_PRIV, work->task, work->type);
835 	put_task_struct(work->task);
836 }
837 
bpf_send_signal_common(u32 sig,enum pid_type type)838 static int bpf_send_signal_common(u32 sig, enum pid_type type)
839 {
840 	struct send_signal_irq_work *work = NULL;
841 
842 	/* Similar to bpf_probe_write_user, task needs to be
843 	 * in a sound condition and kernel memory access be
844 	 * permitted in order to send signal to the current
845 	 * task.
846 	 */
847 	if (unlikely(current->flags & (PF_KTHREAD | PF_EXITING)))
848 		return -EPERM;
849 	if (unlikely(!nmi_uaccess_okay()))
850 		return -EPERM;
851 	/* Task should not be pid=1 to avoid kernel panic. */
852 	if (unlikely(is_global_init(current)))
853 		return -EPERM;
854 
855 	if (irqs_disabled()) {
856 		/* Do an early check on signal validity. Otherwise,
857 		 * the error is lost in deferred irq_work.
858 		 */
859 		if (unlikely(!valid_signal(sig)))
860 			return -EINVAL;
861 
862 		work = this_cpu_ptr(&send_signal_work);
863 		if (irq_work_is_busy(&work->irq_work))
864 			return -EBUSY;
865 
866 		/* Add the current task, which is the target of sending signal,
867 		 * to the irq_work. The current task may change when queued
868 		 * irq works get executed.
869 		 */
870 		work->task = get_task_struct(current);
871 		work->sig = sig;
872 		work->type = type;
873 		irq_work_queue(&work->irq_work);
874 		return 0;
875 	}
876 
877 	return group_send_sig_info(sig, SEND_SIG_PRIV, current, type);
878 }
879 
BPF_CALL_1(bpf_send_signal,u32,sig)880 BPF_CALL_1(bpf_send_signal, u32, sig)
881 {
882 	return bpf_send_signal_common(sig, PIDTYPE_TGID);
883 }
884 
885 static const struct bpf_func_proto bpf_send_signal_proto = {
886 	.func		= bpf_send_signal,
887 	.gpl_only	= false,
888 	.ret_type	= RET_INTEGER,
889 	.arg1_type	= ARG_ANYTHING,
890 };
891 
BPF_CALL_1(bpf_send_signal_thread,u32,sig)892 BPF_CALL_1(bpf_send_signal_thread, u32, sig)
893 {
894 	return bpf_send_signal_common(sig, PIDTYPE_PID);
895 }
896 
897 static const struct bpf_func_proto bpf_send_signal_thread_proto = {
898 	.func		= bpf_send_signal_thread,
899 	.gpl_only	= false,
900 	.ret_type	= RET_INTEGER,
901 	.arg1_type	= ARG_ANYTHING,
902 };
903 
BPF_CALL_3(bpf_d_path,struct path *,path,char *,buf,u32,sz)904 BPF_CALL_3(bpf_d_path, struct path *, path, char *, buf, u32, sz)
905 {
906 	struct path copy;
907 	long len;
908 	char *p;
909 
910 	if (!sz)
911 		return 0;
912 
913 	/*
914 	 * The path pointer is verified as trusted and safe to use,
915 	 * but let's double check it's valid anyway to workaround
916 	 * potentially broken verifier.
917 	 */
918 	len = copy_from_kernel_nofault(&copy, path, sizeof(*path));
919 	if (len < 0)
920 		return len;
921 
922 	p = d_path(&copy, buf, sz);
923 	if (IS_ERR(p)) {
924 		len = PTR_ERR(p);
925 	} else {
926 		len = buf + sz - p;
927 		memmove(buf, p, len);
928 	}
929 
930 	return len;
931 }
932 
933 BTF_SET_START(btf_allowlist_d_path)
934 #ifdef CONFIG_SECURITY
BTF_ID(func,security_file_permission)935 BTF_ID(func, security_file_permission)
936 BTF_ID(func, security_inode_getattr)
937 BTF_ID(func, security_file_open)
938 #endif
939 #ifdef CONFIG_SECURITY_PATH
940 BTF_ID(func, security_path_truncate)
941 #endif
942 BTF_ID(func, vfs_truncate)
943 BTF_ID(func, vfs_fallocate)
944 BTF_ID(func, dentry_open)
945 BTF_ID(func, vfs_getattr)
946 BTF_ID(func, filp_close)
947 BTF_SET_END(btf_allowlist_d_path)
948 
949 static bool bpf_d_path_allowed(const struct bpf_prog *prog)
950 {
951 	if (prog->type == BPF_PROG_TYPE_TRACING &&
952 	    prog->expected_attach_type == BPF_TRACE_ITER)
953 		return true;
954 
955 	if (prog->type == BPF_PROG_TYPE_LSM)
956 		return bpf_lsm_is_sleepable_hook(prog->aux->attach_btf_id);
957 
958 	return btf_id_set_contains(&btf_allowlist_d_path,
959 				   prog->aux->attach_btf_id);
960 }
961 
962 BTF_ID_LIST_SINGLE(bpf_d_path_btf_ids, struct, path)
963 
964 static const struct bpf_func_proto bpf_d_path_proto = {
965 	.func		= bpf_d_path,
966 	.gpl_only	= false,
967 	.ret_type	= RET_INTEGER,
968 	.arg1_type	= ARG_PTR_TO_BTF_ID,
969 	.arg1_btf_id	= &bpf_d_path_btf_ids[0],
970 	.arg2_type	= ARG_PTR_TO_MEM,
971 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
972 	.allowed	= bpf_d_path_allowed,
973 };
974 
975 #define BTF_F_ALL	(BTF_F_COMPACT  | BTF_F_NONAME | \
976 			 BTF_F_PTR_RAW | BTF_F_ZERO)
977 
bpf_btf_printf_prepare(struct btf_ptr * ptr,u32 btf_ptr_size,u64 flags,const struct btf ** btf,s32 * btf_id)978 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size,
979 				  u64 flags, const struct btf **btf,
980 				  s32 *btf_id)
981 {
982 	const struct btf_type *t;
983 
984 	if (unlikely(flags & ~(BTF_F_ALL)))
985 		return -EINVAL;
986 
987 	if (btf_ptr_size != sizeof(struct btf_ptr))
988 		return -EINVAL;
989 
990 	*btf = bpf_get_btf_vmlinux();
991 
992 	if (IS_ERR_OR_NULL(*btf))
993 		return IS_ERR(*btf) ? PTR_ERR(*btf) : -EINVAL;
994 
995 	if (ptr->type_id > 0)
996 		*btf_id = ptr->type_id;
997 	else
998 		return -EINVAL;
999 
1000 	if (*btf_id > 0)
1001 		t = btf_type_by_id(*btf, *btf_id);
1002 	if (*btf_id <= 0 || !t)
1003 		return -ENOENT;
1004 
1005 	return 0;
1006 }
1007 
BPF_CALL_5(bpf_snprintf_btf,char *,str,u32,str_size,struct btf_ptr *,ptr,u32,btf_ptr_size,u64,flags)1008 BPF_CALL_5(bpf_snprintf_btf, char *, str, u32, str_size, struct btf_ptr *, ptr,
1009 	   u32, btf_ptr_size, u64, flags)
1010 {
1011 	const struct btf *btf;
1012 	s32 btf_id;
1013 	int ret;
1014 
1015 	ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id);
1016 	if (ret)
1017 		return ret;
1018 
1019 	return btf_type_snprintf_show(btf, btf_id, ptr->ptr, str, str_size,
1020 				      flags);
1021 }
1022 
1023 const struct bpf_func_proto bpf_snprintf_btf_proto = {
1024 	.func		= bpf_snprintf_btf,
1025 	.gpl_only	= false,
1026 	.ret_type	= RET_INTEGER,
1027 	.arg1_type	= ARG_PTR_TO_MEM,
1028 	.arg2_type	= ARG_CONST_SIZE,
1029 	.arg3_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
1030 	.arg4_type	= ARG_CONST_SIZE,
1031 	.arg5_type	= ARG_ANYTHING,
1032 };
1033 
BPF_CALL_1(bpf_get_func_ip_tracing,void *,ctx)1034 BPF_CALL_1(bpf_get_func_ip_tracing, void *, ctx)
1035 {
1036 	/* This helper call is inlined by verifier. */
1037 	return ((u64 *)ctx)[-2];
1038 }
1039 
1040 static const struct bpf_func_proto bpf_get_func_ip_proto_tracing = {
1041 	.func		= bpf_get_func_ip_tracing,
1042 	.gpl_only	= true,
1043 	.ret_type	= RET_INTEGER,
1044 	.arg1_type	= ARG_PTR_TO_CTX,
1045 };
1046 
1047 #ifdef CONFIG_X86_KERNEL_IBT
get_entry_ip(unsigned long fentry_ip)1048 static unsigned long get_entry_ip(unsigned long fentry_ip)
1049 {
1050 	u32 instr;
1051 
1052 	/* Being extra safe in here in case entry ip is on the page-edge. */
1053 	if (get_kernel_nofault(instr, (u32 *) fentry_ip - 1))
1054 		return fentry_ip;
1055 	if (is_endbr(instr))
1056 		fentry_ip -= ENDBR_INSN_SIZE;
1057 	return fentry_ip;
1058 }
1059 #else
1060 #define get_entry_ip(fentry_ip) fentry_ip
1061 #endif
1062 
BPF_CALL_1(bpf_get_func_ip_kprobe,struct pt_regs *,regs)1063 BPF_CALL_1(bpf_get_func_ip_kprobe, struct pt_regs *, regs)
1064 {
1065 	struct bpf_trace_run_ctx *run_ctx __maybe_unused;
1066 	struct kprobe *kp;
1067 
1068 #ifdef CONFIG_UPROBES
1069 	run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx);
1070 	if (run_ctx->is_uprobe)
1071 		return ((struct uprobe_dispatch_data *)current->utask->vaddr)->bp_addr;
1072 #endif
1073 
1074 	kp = kprobe_running();
1075 
1076 	if (!kp || !(kp->flags & KPROBE_FLAG_ON_FUNC_ENTRY))
1077 		return 0;
1078 
1079 	return get_entry_ip((uintptr_t)kp->addr);
1080 }
1081 
1082 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe = {
1083 	.func		= bpf_get_func_ip_kprobe,
1084 	.gpl_only	= true,
1085 	.ret_type	= RET_INTEGER,
1086 	.arg1_type	= ARG_PTR_TO_CTX,
1087 };
1088 
BPF_CALL_1(bpf_get_func_ip_kprobe_multi,struct pt_regs *,regs)1089 BPF_CALL_1(bpf_get_func_ip_kprobe_multi, struct pt_regs *, regs)
1090 {
1091 	return bpf_kprobe_multi_entry_ip(current->bpf_ctx);
1092 }
1093 
1094 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe_multi = {
1095 	.func		= bpf_get_func_ip_kprobe_multi,
1096 	.gpl_only	= false,
1097 	.ret_type	= RET_INTEGER,
1098 	.arg1_type	= ARG_PTR_TO_CTX,
1099 };
1100 
BPF_CALL_1(bpf_get_attach_cookie_kprobe_multi,struct pt_regs *,regs)1101 BPF_CALL_1(bpf_get_attach_cookie_kprobe_multi, struct pt_regs *, regs)
1102 {
1103 	return bpf_kprobe_multi_cookie(current->bpf_ctx);
1104 }
1105 
1106 static const struct bpf_func_proto bpf_get_attach_cookie_proto_kmulti = {
1107 	.func		= bpf_get_attach_cookie_kprobe_multi,
1108 	.gpl_only	= false,
1109 	.ret_type	= RET_INTEGER,
1110 	.arg1_type	= ARG_PTR_TO_CTX,
1111 };
1112 
BPF_CALL_1(bpf_get_func_ip_uprobe_multi,struct pt_regs *,regs)1113 BPF_CALL_1(bpf_get_func_ip_uprobe_multi, struct pt_regs *, regs)
1114 {
1115 	return bpf_uprobe_multi_entry_ip(current->bpf_ctx);
1116 }
1117 
1118 static const struct bpf_func_proto bpf_get_func_ip_proto_uprobe_multi = {
1119 	.func		= bpf_get_func_ip_uprobe_multi,
1120 	.gpl_only	= false,
1121 	.ret_type	= RET_INTEGER,
1122 	.arg1_type	= ARG_PTR_TO_CTX,
1123 };
1124 
BPF_CALL_1(bpf_get_attach_cookie_uprobe_multi,struct pt_regs *,regs)1125 BPF_CALL_1(bpf_get_attach_cookie_uprobe_multi, struct pt_regs *, regs)
1126 {
1127 	return bpf_uprobe_multi_cookie(current->bpf_ctx);
1128 }
1129 
1130 static const struct bpf_func_proto bpf_get_attach_cookie_proto_umulti = {
1131 	.func		= bpf_get_attach_cookie_uprobe_multi,
1132 	.gpl_only	= false,
1133 	.ret_type	= RET_INTEGER,
1134 	.arg1_type	= ARG_PTR_TO_CTX,
1135 };
1136 
BPF_CALL_1(bpf_get_attach_cookie_trace,void *,ctx)1137 BPF_CALL_1(bpf_get_attach_cookie_trace, void *, ctx)
1138 {
1139 	struct bpf_trace_run_ctx *run_ctx;
1140 
1141 	run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx);
1142 	return run_ctx->bpf_cookie;
1143 }
1144 
1145 static const struct bpf_func_proto bpf_get_attach_cookie_proto_trace = {
1146 	.func		= bpf_get_attach_cookie_trace,
1147 	.gpl_only	= false,
1148 	.ret_type	= RET_INTEGER,
1149 	.arg1_type	= ARG_PTR_TO_CTX,
1150 };
1151 
BPF_CALL_1(bpf_get_attach_cookie_pe,struct bpf_perf_event_data_kern *,ctx)1152 BPF_CALL_1(bpf_get_attach_cookie_pe, struct bpf_perf_event_data_kern *, ctx)
1153 {
1154 	return ctx->event->bpf_cookie;
1155 }
1156 
1157 static const struct bpf_func_proto bpf_get_attach_cookie_proto_pe = {
1158 	.func		= bpf_get_attach_cookie_pe,
1159 	.gpl_only	= false,
1160 	.ret_type	= RET_INTEGER,
1161 	.arg1_type	= ARG_PTR_TO_CTX,
1162 };
1163 
BPF_CALL_1(bpf_get_attach_cookie_tracing,void *,ctx)1164 BPF_CALL_1(bpf_get_attach_cookie_tracing, void *, ctx)
1165 {
1166 	struct bpf_trace_run_ctx *run_ctx;
1167 
1168 	run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx);
1169 	return run_ctx->bpf_cookie;
1170 }
1171 
1172 static const struct bpf_func_proto bpf_get_attach_cookie_proto_tracing = {
1173 	.func		= bpf_get_attach_cookie_tracing,
1174 	.gpl_only	= false,
1175 	.ret_type	= RET_INTEGER,
1176 	.arg1_type	= ARG_PTR_TO_CTX,
1177 };
1178 
BPF_CALL_3(bpf_get_branch_snapshot,void *,buf,u32,size,u64,flags)1179 BPF_CALL_3(bpf_get_branch_snapshot, void *, buf, u32, size, u64, flags)
1180 {
1181 #ifndef CONFIG_X86
1182 	return -ENOENT;
1183 #else
1184 	static const u32 br_entry_size = sizeof(struct perf_branch_entry);
1185 	u32 entry_cnt = size / br_entry_size;
1186 
1187 	entry_cnt = static_call(perf_snapshot_branch_stack)(buf, entry_cnt);
1188 
1189 	if (unlikely(flags))
1190 		return -EINVAL;
1191 
1192 	if (!entry_cnt)
1193 		return -ENOENT;
1194 
1195 	return entry_cnt * br_entry_size;
1196 #endif
1197 }
1198 
1199 static const struct bpf_func_proto bpf_get_branch_snapshot_proto = {
1200 	.func		= bpf_get_branch_snapshot,
1201 	.gpl_only	= true,
1202 	.ret_type	= RET_INTEGER,
1203 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
1204 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
1205 };
1206 
BPF_CALL_3(get_func_arg,void *,ctx,u32,n,u64 *,value)1207 BPF_CALL_3(get_func_arg, void *, ctx, u32, n, u64 *, value)
1208 {
1209 	/* This helper call is inlined by verifier. */
1210 	u64 nr_args = ((u64 *)ctx)[-1];
1211 
1212 	if ((u64) n >= nr_args)
1213 		return -EINVAL;
1214 	*value = ((u64 *)ctx)[n];
1215 	return 0;
1216 }
1217 
1218 static const struct bpf_func_proto bpf_get_func_arg_proto = {
1219 	.func		= get_func_arg,
1220 	.ret_type	= RET_INTEGER,
1221 	.arg1_type	= ARG_PTR_TO_CTX,
1222 	.arg2_type	= ARG_ANYTHING,
1223 	.arg3_type	= ARG_PTR_TO_LONG,
1224 };
1225 
BPF_CALL_2(get_func_ret,void *,ctx,u64 *,value)1226 BPF_CALL_2(get_func_ret, void *, ctx, u64 *, value)
1227 {
1228 	/* This helper call is inlined by verifier. */
1229 	u64 nr_args = ((u64 *)ctx)[-1];
1230 
1231 	*value = ((u64 *)ctx)[nr_args];
1232 	return 0;
1233 }
1234 
1235 static const struct bpf_func_proto bpf_get_func_ret_proto = {
1236 	.func		= get_func_ret,
1237 	.ret_type	= RET_INTEGER,
1238 	.arg1_type	= ARG_PTR_TO_CTX,
1239 	.arg2_type	= ARG_PTR_TO_LONG,
1240 };
1241 
BPF_CALL_1(get_func_arg_cnt,void *,ctx)1242 BPF_CALL_1(get_func_arg_cnt, void *, ctx)
1243 {
1244 	/* This helper call is inlined by verifier. */
1245 	return ((u64 *)ctx)[-1];
1246 }
1247 
1248 static const struct bpf_func_proto bpf_get_func_arg_cnt_proto = {
1249 	.func		= get_func_arg_cnt,
1250 	.ret_type	= RET_INTEGER,
1251 	.arg1_type	= ARG_PTR_TO_CTX,
1252 };
1253 
1254 #ifdef CONFIG_KEYS
1255 __diag_push();
1256 __diag_ignore_all("-Wmissing-prototypes",
1257 		  "kfuncs which will be used in BPF programs");
1258 
1259 /**
1260  * bpf_lookup_user_key - lookup a key by its serial
1261  * @serial: key handle serial number
1262  * @flags: lookup-specific flags
1263  *
1264  * Search a key with a given *serial* and the provided *flags*.
1265  * If found, increment the reference count of the key by one, and
1266  * return it in the bpf_key structure.
1267  *
1268  * The bpf_key structure must be passed to bpf_key_put() when done
1269  * with it, so that the key reference count is decremented and the
1270  * bpf_key structure is freed.
1271  *
1272  * Permission checks are deferred to the time the key is used by
1273  * one of the available key-specific kfuncs.
1274  *
1275  * Set *flags* with KEY_LOOKUP_CREATE, to attempt creating a requested
1276  * special keyring (e.g. session keyring), if it doesn't yet exist.
1277  * Set *flags* with KEY_LOOKUP_PARTIAL, to lookup a key without waiting
1278  * for the key construction, and to retrieve uninstantiated keys (keys
1279  * without data attached to them).
1280  *
1281  * Return: a bpf_key pointer with a valid key pointer if the key is found, a
1282  *         NULL pointer otherwise.
1283  */
bpf_lookup_user_key(u32 serial,u64 flags)1284 __bpf_kfunc struct bpf_key *bpf_lookup_user_key(u32 serial, u64 flags)
1285 {
1286 	key_ref_t key_ref;
1287 	struct bpf_key *bkey;
1288 
1289 	if (flags & ~KEY_LOOKUP_ALL)
1290 		return NULL;
1291 
1292 	/*
1293 	 * Permission check is deferred until the key is used, as the
1294 	 * intent of the caller is unknown here.
1295 	 */
1296 	key_ref = lookup_user_key(serial, flags, KEY_DEFER_PERM_CHECK);
1297 	if (IS_ERR(key_ref))
1298 		return NULL;
1299 
1300 	bkey = kmalloc(sizeof(*bkey), GFP_KERNEL);
1301 	if (!bkey) {
1302 		key_put(key_ref_to_ptr(key_ref));
1303 		return NULL;
1304 	}
1305 
1306 	bkey->key = key_ref_to_ptr(key_ref);
1307 	bkey->has_ref = true;
1308 
1309 	return bkey;
1310 }
1311 
1312 /**
1313  * bpf_lookup_system_key - lookup a key by a system-defined ID
1314  * @id: key ID
1315  *
1316  * Obtain a bpf_key structure with a key pointer set to the passed key ID.
1317  * The key pointer is marked as invalid, to prevent bpf_key_put() from
1318  * attempting to decrement the key reference count on that pointer. The key
1319  * pointer set in such way is currently understood only by
1320  * verify_pkcs7_signature().
1321  *
1322  * Set *id* to one of the values defined in include/linux/verification.h:
1323  * 0 for the primary keyring (immutable keyring of system keys);
1324  * VERIFY_USE_SECONDARY_KEYRING for both the primary and secondary keyring
1325  * (where keys can be added only if they are vouched for by existing keys
1326  * in those keyrings); VERIFY_USE_PLATFORM_KEYRING for the platform
1327  * keyring (primarily used by the integrity subsystem to verify a kexec'ed
1328  * kerned image and, possibly, the initramfs signature).
1329  *
1330  * Return: a bpf_key pointer with an invalid key pointer set from the
1331  *         pre-determined ID on success, a NULL pointer otherwise
1332  */
bpf_lookup_system_key(u64 id)1333 __bpf_kfunc struct bpf_key *bpf_lookup_system_key(u64 id)
1334 {
1335 	struct bpf_key *bkey;
1336 
1337 	if (system_keyring_id_check(id) < 0)
1338 		return NULL;
1339 
1340 	bkey = kmalloc(sizeof(*bkey), GFP_ATOMIC);
1341 	if (!bkey)
1342 		return NULL;
1343 
1344 	bkey->key = (struct key *)(unsigned long)id;
1345 	bkey->has_ref = false;
1346 
1347 	return bkey;
1348 }
1349 
1350 /**
1351  * bpf_key_put - decrement key reference count if key is valid and free bpf_key
1352  * @bkey: bpf_key structure
1353  *
1354  * Decrement the reference count of the key inside *bkey*, if the pointer
1355  * is valid, and free *bkey*.
1356  */
bpf_key_put(struct bpf_key * bkey)1357 __bpf_kfunc void bpf_key_put(struct bpf_key *bkey)
1358 {
1359 	if (bkey->has_ref)
1360 		key_put(bkey->key);
1361 
1362 	kfree(bkey);
1363 }
1364 
1365 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION
1366 /**
1367  * bpf_verify_pkcs7_signature - verify a PKCS#7 signature
1368  * @data_ptr: data to verify
1369  * @sig_ptr: signature of the data
1370  * @trusted_keyring: keyring with keys trusted for signature verification
1371  *
1372  * Verify the PKCS#7 signature *sig_ptr* against the supplied *data_ptr*
1373  * with keys in a keyring referenced by *trusted_keyring*.
1374  *
1375  * Return: 0 on success, a negative value on error.
1376  */
bpf_verify_pkcs7_signature(struct bpf_dynptr_kern * data_ptr,struct bpf_dynptr_kern * sig_ptr,struct bpf_key * trusted_keyring)1377 __bpf_kfunc int bpf_verify_pkcs7_signature(struct bpf_dynptr_kern *data_ptr,
1378 			       struct bpf_dynptr_kern *sig_ptr,
1379 			       struct bpf_key *trusted_keyring)
1380 {
1381 	int ret;
1382 
1383 	if (trusted_keyring->has_ref) {
1384 		/*
1385 		 * Do the permission check deferred in bpf_lookup_user_key().
1386 		 * See bpf_lookup_user_key() for more details.
1387 		 *
1388 		 * A call to key_task_permission() here would be redundant, as
1389 		 * it is already done by keyring_search() called by
1390 		 * find_asymmetric_key().
1391 		 */
1392 		ret = key_validate(trusted_keyring->key);
1393 		if (ret < 0)
1394 			return ret;
1395 	}
1396 
1397 	return verify_pkcs7_signature(data_ptr->data,
1398 				      __bpf_dynptr_size(data_ptr),
1399 				      sig_ptr->data,
1400 				      __bpf_dynptr_size(sig_ptr),
1401 				      trusted_keyring->key,
1402 				      VERIFYING_UNSPECIFIED_SIGNATURE, NULL,
1403 				      NULL);
1404 }
1405 #endif /* CONFIG_SYSTEM_DATA_VERIFICATION */
1406 
1407 __diag_pop();
1408 
1409 BTF_SET8_START(key_sig_kfunc_set)
1410 BTF_ID_FLAGS(func, bpf_lookup_user_key, KF_ACQUIRE | KF_RET_NULL | KF_SLEEPABLE)
1411 BTF_ID_FLAGS(func, bpf_lookup_system_key, KF_ACQUIRE | KF_RET_NULL)
1412 BTF_ID_FLAGS(func, bpf_key_put, KF_RELEASE)
1413 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION
1414 BTF_ID_FLAGS(func, bpf_verify_pkcs7_signature, KF_SLEEPABLE)
1415 #endif
1416 BTF_SET8_END(key_sig_kfunc_set)
1417 
1418 static const struct btf_kfunc_id_set bpf_key_sig_kfunc_set = {
1419 	.owner = THIS_MODULE,
1420 	.set = &key_sig_kfunc_set,
1421 };
1422 
bpf_key_sig_kfuncs_init(void)1423 static int __init bpf_key_sig_kfuncs_init(void)
1424 {
1425 	return register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING,
1426 					 &bpf_key_sig_kfunc_set);
1427 }
1428 
1429 late_initcall(bpf_key_sig_kfuncs_init);
1430 #endif /* CONFIG_KEYS */
1431 
1432 static const struct bpf_func_proto *
bpf_tracing_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1433 bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1434 {
1435 	switch (func_id) {
1436 	case BPF_FUNC_map_lookup_elem:
1437 		return &bpf_map_lookup_elem_proto;
1438 	case BPF_FUNC_map_update_elem:
1439 		return &bpf_map_update_elem_proto;
1440 	case BPF_FUNC_map_delete_elem:
1441 		return &bpf_map_delete_elem_proto;
1442 	case BPF_FUNC_map_push_elem:
1443 		return &bpf_map_push_elem_proto;
1444 	case BPF_FUNC_map_pop_elem:
1445 		return &bpf_map_pop_elem_proto;
1446 	case BPF_FUNC_map_peek_elem:
1447 		return &bpf_map_peek_elem_proto;
1448 	case BPF_FUNC_map_lookup_percpu_elem:
1449 		return &bpf_map_lookup_percpu_elem_proto;
1450 	case BPF_FUNC_ktime_get_ns:
1451 		return &bpf_ktime_get_ns_proto;
1452 	case BPF_FUNC_ktime_get_boot_ns:
1453 		return &bpf_ktime_get_boot_ns_proto;
1454 	case BPF_FUNC_tail_call:
1455 		return &bpf_tail_call_proto;
1456 	case BPF_FUNC_get_current_pid_tgid:
1457 		return &bpf_get_current_pid_tgid_proto;
1458 	case BPF_FUNC_get_current_task:
1459 		return &bpf_get_current_task_proto;
1460 	case BPF_FUNC_get_current_task_btf:
1461 		return &bpf_get_current_task_btf_proto;
1462 	case BPF_FUNC_task_pt_regs:
1463 		return &bpf_task_pt_regs_proto;
1464 	case BPF_FUNC_get_current_uid_gid:
1465 		return &bpf_get_current_uid_gid_proto;
1466 	case BPF_FUNC_get_current_comm:
1467 		return &bpf_get_current_comm_proto;
1468 	case BPF_FUNC_trace_printk:
1469 		return bpf_get_trace_printk_proto();
1470 	case BPF_FUNC_get_smp_processor_id:
1471 		return &bpf_get_smp_processor_id_proto;
1472 	case BPF_FUNC_get_numa_node_id:
1473 		return &bpf_get_numa_node_id_proto;
1474 	case BPF_FUNC_perf_event_read:
1475 		return &bpf_perf_event_read_proto;
1476 	case BPF_FUNC_current_task_under_cgroup:
1477 		return &bpf_current_task_under_cgroup_proto;
1478 	case BPF_FUNC_get_prandom_u32:
1479 		return &bpf_get_prandom_u32_proto;
1480 	case BPF_FUNC_probe_write_user:
1481 		return security_locked_down(LOCKDOWN_BPF_WRITE_USER) < 0 ?
1482 		       NULL : bpf_get_probe_write_proto();
1483 	case BPF_FUNC_probe_read_user:
1484 		return &bpf_probe_read_user_proto;
1485 	case BPF_FUNC_probe_read_kernel:
1486 		return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
1487 		       NULL : &bpf_probe_read_kernel_proto;
1488 	case BPF_FUNC_probe_read_user_str:
1489 		return &bpf_probe_read_user_str_proto;
1490 	case BPF_FUNC_probe_read_kernel_str:
1491 		return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
1492 		       NULL : &bpf_probe_read_kernel_str_proto;
1493 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
1494 	case BPF_FUNC_probe_read:
1495 		return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
1496 		       NULL : &bpf_probe_read_compat_proto;
1497 	case BPF_FUNC_probe_read_str:
1498 		return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
1499 		       NULL : &bpf_probe_read_compat_str_proto;
1500 #endif
1501 #ifdef CONFIG_CGROUPS
1502 	case BPF_FUNC_cgrp_storage_get:
1503 		return &bpf_cgrp_storage_get_proto;
1504 	case BPF_FUNC_cgrp_storage_delete:
1505 		return &bpf_cgrp_storage_delete_proto;
1506 #endif
1507 	case BPF_FUNC_send_signal:
1508 		return &bpf_send_signal_proto;
1509 	case BPF_FUNC_send_signal_thread:
1510 		return &bpf_send_signal_thread_proto;
1511 	case BPF_FUNC_perf_event_read_value:
1512 		return &bpf_perf_event_read_value_proto;
1513 	case BPF_FUNC_get_ns_current_pid_tgid:
1514 		return &bpf_get_ns_current_pid_tgid_proto;
1515 	case BPF_FUNC_ringbuf_output:
1516 		return &bpf_ringbuf_output_proto;
1517 	case BPF_FUNC_ringbuf_reserve:
1518 		return &bpf_ringbuf_reserve_proto;
1519 	case BPF_FUNC_ringbuf_submit:
1520 		return &bpf_ringbuf_submit_proto;
1521 	case BPF_FUNC_ringbuf_discard:
1522 		return &bpf_ringbuf_discard_proto;
1523 	case BPF_FUNC_ringbuf_query:
1524 		return &bpf_ringbuf_query_proto;
1525 	case BPF_FUNC_jiffies64:
1526 		return &bpf_jiffies64_proto;
1527 	case BPF_FUNC_get_task_stack:
1528 		return &bpf_get_task_stack_proto;
1529 	case BPF_FUNC_copy_from_user:
1530 		return &bpf_copy_from_user_proto;
1531 	case BPF_FUNC_copy_from_user_task:
1532 		return &bpf_copy_from_user_task_proto;
1533 	case BPF_FUNC_snprintf_btf:
1534 		return &bpf_snprintf_btf_proto;
1535 	case BPF_FUNC_per_cpu_ptr:
1536 		return &bpf_per_cpu_ptr_proto;
1537 	case BPF_FUNC_this_cpu_ptr:
1538 		return &bpf_this_cpu_ptr_proto;
1539 	case BPF_FUNC_task_storage_get:
1540 		if (bpf_prog_check_recur(prog))
1541 			return &bpf_task_storage_get_recur_proto;
1542 		return &bpf_task_storage_get_proto;
1543 	case BPF_FUNC_task_storage_delete:
1544 		if (bpf_prog_check_recur(prog))
1545 			return &bpf_task_storage_delete_recur_proto;
1546 		return &bpf_task_storage_delete_proto;
1547 	case BPF_FUNC_for_each_map_elem:
1548 		return &bpf_for_each_map_elem_proto;
1549 	case BPF_FUNC_snprintf:
1550 		return &bpf_snprintf_proto;
1551 	case BPF_FUNC_get_func_ip:
1552 		return &bpf_get_func_ip_proto_tracing;
1553 	case BPF_FUNC_get_branch_snapshot:
1554 		return &bpf_get_branch_snapshot_proto;
1555 	case BPF_FUNC_find_vma:
1556 		return &bpf_find_vma_proto;
1557 	case BPF_FUNC_trace_vprintk:
1558 		return bpf_get_trace_vprintk_proto();
1559 	default:
1560 		return bpf_base_func_proto(func_id);
1561 	}
1562 }
1563 
1564 static const struct bpf_func_proto *
kprobe_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1565 kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1566 {
1567 	switch (func_id) {
1568 	case BPF_FUNC_perf_event_output:
1569 		return &bpf_perf_event_output_proto;
1570 	case BPF_FUNC_get_stackid:
1571 		return &bpf_get_stackid_proto;
1572 	case BPF_FUNC_get_stack:
1573 		return &bpf_get_stack_proto;
1574 #ifdef CONFIG_BPF_KPROBE_OVERRIDE
1575 	case BPF_FUNC_override_return:
1576 		return &bpf_override_return_proto;
1577 #endif
1578 	case BPF_FUNC_get_func_ip:
1579 		if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI)
1580 			return &bpf_get_func_ip_proto_kprobe_multi;
1581 		if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI)
1582 			return &bpf_get_func_ip_proto_uprobe_multi;
1583 		return &bpf_get_func_ip_proto_kprobe;
1584 	case BPF_FUNC_get_attach_cookie:
1585 		if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI)
1586 			return &bpf_get_attach_cookie_proto_kmulti;
1587 		if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI)
1588 			return &bpf_get_attach_cookie_proto_umulti;
1589 		return &bpf_get_attach_cookie_proto_trace;
1590 	default:
1591 		return bpf_tracing_func_proto(func_id, prog);
1592 	}
1593 }
1594 
1595 /* 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)1596 static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
1597 					const struct bpf_prog *prog,
1598 					struct bpf_insn_access_aux *info)
1599 {
1600 	if (off < 0 || off >= sizeof(struct pt_regs))
1601 		return false;
1602 	if (type != BPF_READ)
1603 		return false;
1604 	if (off % size != 0)
1605 		return false;
1606 	/*
1607 	 * Assertion for 32 bit to make sure last 8 byte access
1608 	 * (BPF_DW) to the last 4 byte member is disallowed.
1609 	 */
1610 	if (off + size > sizeof(struct pt_regs))
1611 		return false;
1612 
1613 	return true;
1614 }
1615 
1616 const struct bpf_verifier_ops kprobe_verifier_ops = {
1617 	.get_func_proto  = kprobe_prog_func_proto,
1618 	.is_valid_access = kprobe_prog_is_valid_access,
1619 };
1620 
1621 const struct bpf_prog_ops kprobe_prog_ops = {
1622 };
1623 
BPF_CALL_5(bpf_perf_event_output_tp,void *,tp_buff,struct bpf_map *,map,u64,flags,void *,data,u64,size)1624 BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map,
1625 	   u64, flags, void *, data, u64, size)
1626 {
1627 	struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1628 
1629 	/*
1630 	 * r1 points to perf tracepoint buffer where first 8 bytes are hidden
1631 	 * from bpf program and contain a pointer to 'struct pt_regs'. Fetch it
1632 	 * from there and call the same bpf_perf_event_output() helper inline.
1633 	 */
1634 	return ____bpf_perf_event_output(regs, map, flags, data, size);
1635 }
1636 
1637 static const struct bpf_func_proto bpf_perf_event_output_proto_tp = {
1638 	.func		= bpf_perf_event_output_tp,
1639 	.gpl_only	= true,
1640 	.ret_type	= RET_INTEGER,
1641 	.arg1_type	= ARG_PTR_TO_CTX,
1642 	.arg2_type	= ARG_CONST_MAP_PTR,
1643 	.arg3_type	= ARG_ANYTHING,
1644 	.arg4_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
1645 	.arg5_type	= ARG_CONST_SIZE_OR_ZERO,
1646 };
1647 
BPF_CALL_3(bpf_get_stackid_tp,void *,tp_buff,struct bpf_map *,map,u64,flags)1648 BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map,
1649 	   u64, flags)
1650 {
1651 	struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1652 
1653 	/*
1654 	 * Same comment as in bpf_perf_event_output_tp(), only that this time
1655 	 * the other helper's function body cannot be inlined due to being
1656 	 * external, thus we need to call raw helper function.
1657 	 */
1658 	return bpf_get_stackid((unsigned long) regs, (unsigned long) map,
1659 			       flags, 0, 0);
1660 }
1661 
1662 static const struct bpf_func_proto bpf_get_stackid_proto_tp = {
1663 	.func		= bpf_get_stackid_tp,
1664 	.gpl_only	= true,
1665 	.ret_type	= RET_INTEGER,
1666 	.arg1_type	= ARG_PTR_TO_CTX,
1667 	.arg2_type	= ARG_CONST_MAP_PTR,
1668 	.arg3_type	= ARG_ANYTHING,
1669 };
1670 
BPF_CALL_4(bpf_get_stack_tp,void *,tp_buff,void *,buf,u32,size,u64,flags)1671 BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size,
1672 	   u64, flags)
1673 {
1674 	struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1675 
1676 	return bpf_get_stack((unsigned long) regs, (unsigned long) buf,
1677 			     (unsigned long) size, flags, 0);
1678 }
1679 
1680 static const struct bpf_func_proto bpf_get_stack_proto_tp = {
1681 	.func		= bpf_get_stack_tp,
1682 	.gpl_only	= true,
1683 	.ret_type	= RET_INTEGER,
1684 	.arg1_type	= ARG_PTR_TO_CTX,
1685 	.arg2_type	= ARG_PTR_TO_UNINIT_MEM,
1686 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
1687 	.arg4_type	= ARG_ANYTHING,
1688 };
1689 
1690 static const struct bpf_func_proto *
tp_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1691 tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1692 {
1693 	switch (func_id) {
1694 	case BPF_FUNC_perf_event_output:
1695 		return &bpf_perf_event_output_proto_tp;
1696 	case BPF_FUNC_get_stackid:
1697 		return &bpf_get_stackid_proto_tp;
1698 	case BPF_FUNC_get_stack:
1699 		return &bpf_get_stack_proto_tp;
1700 	case BPF_FUNC_get_attach_cookie:
1701 		return &bpf_get_attach_cookie_proto_trace;
1702 	default:
1703 		return bpf_tracing_func_proto(func_id, prog);
1704 	}
1705 }
1706 
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)1707 static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type,
1708 				    const struct bpf_prog *prog,
1709 				    struct bpf_insn_access_aux *info)
1710 {
1711 	if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE)
1712 		return false;
1713 	if (type != BPF_READ)
1714 		return false;
1715 	if (off % size != 0)
1716 		return false;
1717 
1718 	BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(__u64));
1719 	return true;
1720 }
1721 
1722 const struct bpf_verifier_ops tracepoint_verifier_ops = {
1723 	.get_func_proto  = tp_prog_func_proto,
1724 	.is_valid_access = tp_prog_is_valid_access,
1725 };
1726 
1727 const struct bpf_prog_ops tracepoint_prog_ops = {
1728 };
1729 
BPF_CALL_3(bpf_perf_prog_read_value,struct bpf_perf_event_data_kern *,ctx,struct bpf_perf_event_value *,buf,u32,size)1730 BPF_CALL_3(bpf_perf_prog_read_value, struct bpf_perf_event_data_kern *, ctx,
1731 	   struct bpf_perf_event_value *, buf, u32, size)
1732 {
1733 	int err = -EINVAL;
1734 
1735 	if (unlikely(size != sizeof(struct bpf_perf_event_value)))
1736 		goto clear;
1737 	err = perf_event_read_local(ctx->event, &buf->counter, &buf->enabled,
1738 				    &buf->running);
1739 	if (unlikely(err))
1740 		goto clear;
1741 	return 0;
1742 clear:
1743 	memset(buf, 0, size);
1744 	return err;
1745 }
1746 
1747 static const struct bpf_func_proto bpf_perf_prog_read_value_proto = {
1748          .func           = bpf_perf_prog_read_value,
1749          .gpl_only       = true,
1750          .ret_type       = RET_INTEGER,
1751          .arg1_type      = ARG_PTR_TO_CTX,
1752          .arg2_type      = ARG_PTR_TO_UNINIT_MEM,
1753          .arg3_type      = ARG_CONST_SIZE,
1754 };
1755 
BPF_CALL_4(bpf_read_branch_records,struct bpf_perf_event_data_kern *,ctx,void *,buf,u32,size,u64,flags)1756 BPF_CALL_4(bpf_read_branch_records, struct bpf_perf_event_data_kern *, ctx,
1757 	   void *, buf, u32, size, u64, flags)
1758 {
1759 	static const u32 br_entry_size = sizeof(struct perf_branch_entry);
1760 	struct perf_branch_stack *br_stack = ctx->data->br_stack;
1761 	u32 to_copy;
1762 
1763 	if (unlikely(flags & ~BPF_F_GET_BRANCH_RECORDS_SIZE))
1764 		return -EINVAL;
1765 
1766 	if (unlikely(!(ctx->data->sample_flags & PERF_SAMPLE_BRANCH_STACK)))
1767 		return -ENOENT;
1768 
1769 	if (unlikely(!br_stack))
1770 		return -ENOENT;
1771 
1772 	if (flags & BPF_F_GET_BRANCH_RECORDS_SIZE)
1773 		return br_stack->nr * br_entry_size;
1774 
1775 	if (!buf || (size % br_entry_size != 0))
1776 		return -EINVAL;
1777 
1778 	to_copy = min_t(u32, br_stack->nr * br_entry_size, size);
1779 	memcpy(buf, br_stack->entries, to_copy);
1780 
1781 	return to_copy;
1782 }
1783 
1784 static const struct bpf_func_proto bpf_read_branch_records_proto = {
1785 	.func           = bpf_read_branch_records,
1786 	.gpl_only       = true,
1787 	.ret_type       = RET_INTEGER,
1788 	.arg1_type      = ARG_PTR_TO_CTX,
1789 	.arg2_type      = ARG_PTR_TO_MEM_OR_NULL,
1790 	.arg3_type      = ARG_CONST_SIZE_OR_ZERO,
1791 	.arg4_type      = ARG_ANYTHING,
1792 };
1793 
1794 static const struct bpf_func_proto *
pe_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1795 pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1796 {
1797 	switch (func_id) {
1798 	case BPF_FUNC_perf_event_output:
1799 		return &bpf_perf_event_output_proto_tp;
1800 	case BPF_FUNC_get_stackid:
1801 		return &bpf_get_stackid_proto_pe;
1802 	case BPF_FUNC_get_stack:
1803 		return &bpf_get_stack_proto_pe;
1804 	case BPF_FUNC_perf_prog_read_value:
1805 		return &bpf_perf_prog_read_value_proto;
1806 	case BPF_FUNC_read_branch_records:
1807 		return &bpf_read_branch_records_proto;
1808 	case BPF_FUNC_get_attach_cookie:
1809 		return &bpf_get_attach_cookie_proto_pe;
1810 	default:
1811 		return bpf_tracing_func_proto(func_id, prog);
1812 	}
1813 }
1814 
1815 /*
1816  * bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp
1817  * to avoid potential recursive reuse issue when/if tracepoints are added
1818  * inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack.
1819  *
1820  * Since raw tracepoints run despite bpf_prog_active, support concurrent usage
1821  * in normal, irq, and nmi context.
1822  */
1823 struct bpf_raw_tp_regs {
1824 	struct pt_regs regs[3];
1825 };
1826 static DEFINE_PER_CPU(struct bpf_raw_tp_regs, bpf_raw_tp_regs);
1827 static DEFINE_PER_CPU(int, bpf_raw_tp_nest_level);
get_bpf_raw_tp_regs(void)1828 static struct pt_regs *get_bpf_raw_tp_regs(void)
1829 {
1830 	struct bpf_raw_tp_regs *tp_regs = this_cpu_ptr(&bpf_raw_tp_regs);
1831 	int nest_level = this_cpu_inc_return(bpf_raw_tp_nest_level);
1832 
1833 	if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(tp_regs->regs))) {
1834 		this_cpu_dec(bpf_raw_tp_nest_level);
1835 		return ERR_PTR(-EBUSY);
1836 	}
1837 
1838 	return &tp_regs->regs[nest_level - 1];
1839 }
1840 
put_bpf_raw_tp_regs(void)1841 static void put_bpf_raw_tp_regs(void)
1842 {
1843 	this_cpu_dec(bpf_raw_tp_nest_level);
1844 }
1845 
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)1846 BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args,
1847 	   struct bpf_map *, map, u64, flags, void *, data, u64, size)
1848 {
1849 	struct pt_regs *regs = get_bpf_raw_tp_regs();
1850 	int ret;
1851 
1852 	if (IS_ERR(regs))
1853 		return PTR_ERR(regs);
1854 
1855 	perf_fetch_caller_regs(regs);
1856 	ret = ____bpf_perf_event_output(regs, map, flags, data, size);
1857 
1858 	put_bpf_raw_tp_regs();
1859 	return ret;
1860 }
1861 
1862 static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = {
1863 	.func		= bpf_perf_event_output_raw_tp,
1864 	.gpl_only	= true,
1865 	.ret_type	= RET_INTEGER,
1866 	.arg1_type	= ARG_PTR_TO_CTX,
1867 	.arg2_type	= ARG_CONST_MAP_PTR,
1868 	.arg3_type	= ARG_ANYTHING,
1869 	.arg4_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
1870 	.arg5_type	= ARG_CONST_SIZE_OR_ZERO,
1871 };
1872 
1873 extern const struct bpf_func_proto bpf_skb_output_proto;
1874 extern const struct bpf_func_proto bpf_xdp_output_proto;
1875 extern const struct bpf_func_proto bpf_xdp_get_buff_len_trace_proto;
1876 
BPF_CALL_3(bpf_get_stackid_raw_tp,struct bpf_raw_tracepoint_args *,args,struct bpf_map *,map,u64,flags)1877 BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args,
1878 	   struct bpf_map *, map, u64, flags)
1879 {
1880 	struct pt_regs *regs = get_bpf_raw_tp_regs();
1881 	int ret;
1882 
1883 	if (IS_ERR(regs))
1884 		return PTR_ERR(regs);
1885 
1886 	perf_fetch_caller_regs(regs);
1887 	/* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */
1888 	ret = bpf_get_stackid((unsigned long) regs, (unsigned long) map,
1889 			      flags, 0, 0);
1890 	put_bpf_raw_tp_regs();
1891 	return ret;
1892 }
1893 
1894 static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = {
1895 	.func		= bpf_get_stackid_raw_tp,
1896 	.gpl_only	= true,
1897 	.ret_type	= RET_INTEGER,
1898 	.arg1_type	= ARG_PTR_TO_CTX,
1899 	.arg2_type	= ARG_CONST_MAP_PTR,
1900 	.arg3_type	= ARG_ANYTHING,
1901 };
1902 
BPF_CALL_4(bpf_get_stack_raw_tp,struct bpf_raw_tracepoint_args *,args,void *,buf,u32,size,u64,flags)1903 BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args,
1904 	   void *, buf, u32, size, u64, flags)
1905 {
1906 	struct pt_regs *regs = get_bpf_raw_tp_regs();
1907 	int ret;
1908 
1909 	if (IS_ERR(regs))
1910 		return PTR_ERR(regs);
1911 
1912 	perf_fetch_caller_regs(regs);
1913 	ret = bpf_get_stack((unsigned long) regs, (unsigned long) buf,
1914 			    (unsigned long) size, flags, 0);
1915 	put_bpf_raw_tp_regs();
1916 	return ret;
1917 }
1918 
1919 static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = {
1920 	.func		= bpf_get_stack_raw_tp,
1921 	.gpl_only	= true,
1922 	.ret_type	= RET_INTEGER,
1923 	.arg1_type	= ARG_PTR_TO_CTX,
1924 	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
1925 	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,
1926 	.arg4_type	= ARG_ANYTHING,
1927 };
1928 
1929 static const struct bpf_func_proto *
raw_tp_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1930 raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1931 {
1932 	switch (func_id) {
1933 	case BPF_FUNC_perf_event_output:
1934 		return &bpf_perf_event_output_proto_raw_tp;
1935 	case BPF_FUNC_get_stackid:
1936 		return &bpf_get_stackid_proto_raw_tp;
1937 	case BPF_FUNC_get_stack:
1938 		return &bpf_get_stack_proto_raw_tp;
1939 	default:
1940 		return bpf_tracing_func_proto(func_id, prog);
1941 	}
1942 }
1943 
1944 const struct bpf_func_proto *
tracing_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1945 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1946 {
1947 	const struct bpf_func_proto *fn;
1948 
1949 	switch (func_id) {
1950 #ifdef CONFIG_NET
1951 	case BPF_FUNC_skb_output:
1952 		return &bpf_skb_output_proto;
1953 	case BPF_FUNC_xdp_output:
1954 		return &bpf_xdp_output_proto;
1955 	case BPF_FUNC_skc_to_tcp6_sock:
1956 		return &bpf_skc_to_tcp6_sock_proto;
1957 	case BPF_FUNC_skc_to_tcp_sock:
1958 		return &bpf_skc_to_tcp_sock_proto;
1959 	case BPF_FUNC_skc_to_tcp_timewait_sock:
1960 		return &bpf_skc_to_tcp_timewait_sock_proto;
1961 	case BPF_FUNC_skc_to_tcp_request_sock:
1962 		return &bpf_skc_to_tcp_request_sock_proto;
1963 	case BPF_FUNC_skc_to_udp6_sock:
1964 		return &bpf_skc_to_udp6_sock_proto;
1965 	case BPF_FUNC_skc_to_unix_sock:
1966 		return &bpf_skc_to_unix_sock_proto;
1967 	case BPF_FUNC_skc_to_mptcp_sock:
1968 		return &bpf_skc_to_mptcp_sock_proto;
1969 	case BPF_FUNC_sk_storage_get:
1970 		return &bpf_sk_storage_get_tracing_proto;
1971 	case BPF_FUNC_sk_storage_delete:
1972 		return &bpf_sk_storage_delete_tracing_proto;
1973 	case BPF_FUNC_sock_from_file:
1974 		return &bpf_sock_from_file_proto;
1975 	case BPF_FUNC_get_socket_cookie:
1976 		return &bpf_get_socket_ptr_cookie_proto;
1977 	case BPF_FUNC_xdp_get_buff_len:
1978 		return &bpf_xdp_get_buff_len_trace_proto;
1979 #endif
1980 	case BPF_FUNC_seq_printf:
1981 		return prog->expected_attach_type == BPF_TRACE_ITER ?
1982 		       &bpf_seq_printf_proto :
1983 		       NULL;
1984 	case BPF_FUNC_seq_write:
1985 		return prog->expected_attach_type == BPF_TRACE_ITER ?
1986 		       &bpf_seq_write_proto :
1987 		       NULL;
1988 	case BPF_FUNC_seq_printf_btf:
1989 		return prog->expected_attach_type == BPF_TRACE_ITER ?
1990 		       &bpf_seq_printf_btf_proto :
1991 		       NULL;
1992 	case BPF_FUNC_d_path:
1993 		return &bpf_d_path_proto;
1994 	case BPF_FUNC_get_func_arg:
1995 		return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_proto : NULL;
1996 	case BPF_FUNC_get_func_ret:
1997 		return bpf_prog_has_trampoline(prog) ? &bpf_get_func_ret_proto : NULL;
1998 	case BPF_FUNC_get_func_arg_cnt:
1999 		return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_cnt_proto : NULL;
2000 	case BPF_FUNC_get_attach_cookie:
2001 		return bpf_prog_has_trampoline(prog) ? &bpf_get_attach_cookie_proto_tracing : NULL;
2002 	default:
2003 		fn = raw_tp_prog_func_proto(func_id, prog);
2004 		if (!fn && prog->expected_attach_type == BPF_TRACE_ITER)
2005 			fn = bpf_iter_get_func_proto(func_id, prog);
2006 		return fn;
2007 	}
2008 }
2009 
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)2010 static bool raw_tp_prog_is_valid_access(int off, int size,
2011 					enum bpf_access_type type,
2012 					const struct bpf_prog *prog,
2013 					struct bpf_insn_access_aux *info)
2014 {
2015 	return bpf_tracing_ctx_access(off, size, type);
2016 }
2017 
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)2018 static bool tracing_prog_is_valid_access(int off, int size,
2019 					 enum bpf_access_type type,
2020 					 const struct bpf_prog *prog,
2021 					 struct bpf_insn_access_aux *info)
2022 {
2023 	return bpf_tracing_btf_ctx_access(off, size, type, prog, info);
2024 }
2025 
bpf_prog_test_run_tracing(struct bpf_prog * prog,const union bpf_attr * kattr,union bpf_attr __user * uattr)2026 int __weak bpf_prog_test_run_tracing(struct bpf_prog *prog,
2027 				     const union bpf_attr *kattr,
2028 				     union bpf_attr __user *uattr)
2029 {
2030 	return -ENOTSUPP;
2031 }
2032 
2033 const struct bpf_verifier_ops raw_tracepoint_verifier_ops = {
2034 	.get_func_proto  = raw_tp_prog_func_proto,
2035 	.is_valid_access = raw_tp_prog_is_valid_access,
2036 };
2037 
2038 const struct bpf_prog_ops raw_tracepoint_prog_ops = {
2039 #ifdef CONFIG_NET
2040 	.test_run = bpf_prog_test_run_raw_tp,
2041 #endif
2042 };
2043 
2044 const struct bpf_verifier_ops tracing_verifier_ops = {
2045 	.get_func_proto  = tracing_prog_func_proto,
2046 	.is_valid_access = tracing_prog_is_valid_access,
2047 };
2048 
2049 const struct bpf_prog_ops tracing_prog_ops = {
2050 	.test_run = bpf_prog_test_run_tracing,
2051 };
2052 
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)2053 static bool raw_tp_writable_prog_is_valid_access(int off, int size,
2054 						 enum bpf_access_type type,
2055 						 const struct bpf_prog *prog,
2056 						 struct bpf_insn_access_aux *info)
2057 {
2058 	if (off == 0) {
2059 		if (size != sizeof(u64) || type != BPF_READ)
2060 			return false;
2061 		info->reg_type = PTR_TO_TP_BUFFER;
2062 	}
2063 	return raw_tp_prog_is_valid_access(off, size, type, prog, info);
2064 }
2065 
2066 const struct bpf_verifier_ops raw_tracepoint_writable_verifier_ops = {
2067 	.get_func_proto  = raw_tp_prog_func_proto,
2068 	.is_valid_access = raw_tp_writable_prog_is_valid_access,
2069 };
2070 
2071 const struct bpf_prog_ops raw_tracepoint_writable_prog_ops = {
2072 };
2073 
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)2074 static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
2075 				    const struct bpf_prog *prog,
2076 				    struct bpf_insn_access_aux *info)
2077 {
2078 	const int size_u64 = sizeof(u64);
2079 
2080 	if (off < 0 || off >= sizeof(struct bpf_perf_event_data))
2081 		return false;
2082 	if (type != BPF_READ)
2083 		return false;
2084 	if (off % size != 0) {
2085 		if (sizeof(unsigned long) != 4)
2086 			return false;
2087 		if (size != 8)
2088 			return false;
2089 		if (off % size != 4)
2090 			return false;
2091 	}
2092 
2093 	switch (off) {
2094 	case bpf_ctx_range(struct bpf_perf_event_data, sample_period):
2095 		bpf_ctx_record_field_size(info, size_u64);
2096 		if (!bpf_ctx_narrow_access_ok(off, size, size_u64))
2097 			return false;
2098 		break;
2099 	case bpf_ctx_range(struct bpf_perf_event_data, addr):
2100 		bpf_ctx_record_field_size(info, size_u64);
2101 		if (!bpf_ctx_narrow_access_ok(off, size, size_u64))
2102 			return false;
2103 		break;
2104 	default:
2105 		if (size != sizeof(long))
2106 			return false;
2107 	}
2108 
2109 	return true;
2110 }
2111 
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)2112 static u32 pe_prog_convert_ctx_access(enum bpf_access_type type,
2113 				      const struct bpf_insn *si,
2114 				      struct bpf_insn *insn_buf,
2115 				      struct bpf_prog *prog, u32 *target_size)
2116 {
2117 	struct bpf_insn *insn = insn_buf;
2118 
2119 	switch (si->off) {
2120 	case offsetof(struct bpf_perf_event_data, sample_period):
2121 		*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
2122 						       data), si->dst_reg, si->src_reg,
2123 				      offsetof(struct bpf_perf_event_data_kern, data));
2124 		*insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg,
2125 				      bpf_target_off(struct perf_sample_data, period, 8,
2126 						     target_size));
2127 		break;
2128 	case offsetof(struct bpf_perf_event_data, addr):
2129 		*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
2130 						       data), si->dst_reg, si->src_reg,
2131 				      offsetof(struct bpf_perf_event_data_kern, data));
2132 		*insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg,
2133 				      bpf_target_off(struct perf_sample_data, addr, 8,
2134 						     target_size));
2135 		break;
2136 	default:
2137 		*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
2138 						       regs), si->dst_reg, si->src_reg,
2139 				      offsetof(struct bpf_perf_event_data_kern, regs));
2140 		*insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg,
2141 				      si->off);
2142 		break;
2143 	}
2144 
2145 	return insn - insn_buf;
2146 }
2147 
2148 const struct bpf_verifier_ops perf_event_verifier_ops = {
2149 	.get_func_proto		= pe_prog_func_proto,
2150 	.is_valid_access	= pe_prog_is_valid_access,
2151 	.convert_ctx_access	= pe_prog_convert_ctx_access,
2152 };
2153 
2154 const struct bpf_prog_ops perf_event_prog_ops = {
2155 };
2156 
2157 static DEFINE_MUTEX(bpf_event_mutex);
2158 
2159 #define BPF_TRACE_MAX_PROGS 64
2160 
perf_event_attach_bpf_prog(struct perf_event * event,struct bpf_prog * prog,u64 bpf_cookie)2161 int perf_event_attach_bpf_prog(struct perf_event *event,
2162 			       struct bpf_prog *prog,
2163 			       u64 bpf_cookie)
2164 {
2165 	struct bpf_prog_array *old_array;
2166 	struct bpf_prog_array *new_array;
2167 	int ret = -EEXIST;
2168 
2169 	/*
2170 	 * Kprobe override only works if they are on the function entry,
2171 	 * and only if they are on the opt-in list.
2172 	 */
2173 	if (prog->kprobe_override &&
2174 	    (!trace_kprobe_on_func_entry(event->tp_event) ||
2175 	     !trace_kprobe_error_injectable(event->tp_event)))
2176 		return -EINVAL;
2177 
2178 	mutex_lock(&bpf_event_mutex);
2179 
2180 	if (event->prog)
2181 		goto unlock;
2182 
2183 	old_array = bpf_event_rcu_dereference(event->tp_event->prog_array);
2184 	if (old_array &&
2185 	    bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) {
2186 		ret = -E2BIG;
2187 		goto unlock;
2188 	}
2189 
2190 	ret = bpf_prog_array_copy(old_array, NULL, prog, bpf_cookie, &new_array);
2191 	if (ret < 0)
2192 		goto unlock;
2193 
2194 	/* set the new array to event->tp_event and set event->prog */
2195 	event->prog = prog;
2196 	event->bpf_cookie = bpf_cookie;
2197 	rcu_assign_pointer(event->tp_event->prog_array, new_array);
2198 	bpf_prog_array_free_sleepable(old_array);
2199 
2200 unlock:
2201 	mutex_unlock(&bpf_event_mutex);
2202 	return ret;
2203 }
2204 
perf_event_detach_bpf_prog(struct perf_event * event)2205 void perf_event_detach_bpf_prog(struct perf_event *event)
2206 {
2207 	struct bpf_prog_array *old_array;
2208 	struct bpf_prog_array *new_array;
2209 	int ret;
2210 
2211 	mutex_lock(&bpf_event_mutex);
2212 
2213 	if (!event->prog)
2214 		goto unlock;
2215 
2216 	old_array = bpf_event_rcu_dereference(event->tp_event->prog_array);
2217 	ret = bpf_prog_array_copy(old_array, event->prog, NULL, 0, &new_array);
2218 	if (ret == -ENOENT)
2219 		goto unlock;
2220 	if (ret < 0) {
2221 		bpf_prog_array_delete_safe(old_array, event->prog);
2222 	} else {
2223 		rcu_assign_pointer(event->tp_event->prog_array, new_array);
2224 		bpf_prog_array_free_sleepable(old_array);
2225 	}
2226 
2227 	bpf_prog_put(event->prog);
2228 	event->prog = NULL;
2229 
2230 unlock:
2231 	mutex_unlock(&bpf_event_mutex);
2232 }
2233 
perf_event_query_prog_array(struct perf_event * event,void __user * info)2234 int perf_event_query_prog_array(struct perf_event *event, void __user *info)
2235 {
2236 	struct perf_event_query_bpf __user *uquery = info;
2237 	struct perf_event_query_bpf query = {};
2238 	struct bpf_prog_array *progs;
2239 	u32 *ids, prog_cnt, ids_len;
2240 	int ret;
2241 
2242 	if (!perfmon_capable())
2243 		return -EPERM;
2244 	if (event->attr.type != PERF_TYPE_TRACEPOINT)
2245 		return -EINVAL;
2246 	if (copy_from_user(&query, uquery, sizeof(query)))
2247 		return -EFAULT;
2248 
2249 	ids_len = query.ids_len;
2250 	if (ids_len > BPF_TRACE_MAX_PROGS)
2251 		return -E2BIG;
2252 	ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN);
2253 	if (!ids)
2254 		return -ENOMEM;
2255 	/*
2256 	 * The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which
2257 	 * is required when user only wants to check for uquery->prog_cnt.
2258 	 * There is no need to check for it since the case is handled
2259 	 * gracefully in bpf_prog_array_copy_info.
2260 	 */
2261 
2262 	mutex_lock(&bpf_event_mutex);
2263 	progs = bpf_event_rcu_dereference(event->tp_event->prog_array);
2264 	ret = bpf_prog_array_copy_info(progs, ids, ids_len, &prog_cnt);
2265 	mutex_unlock(&bpf_event_mutex);
2266 
2267 	if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) ||
2268 	    copy_to_user(uquery->ids, ids, ids_len * sizeof(u32)))
2269 		ret = -EFAULT;
2270 
2271 	kfree(ids);
2272 	return ret;
2273 }
2274 
2275 extern struct bpf_raw_event_map __start__bpf_raw_tp[];
2276 extern struct bpf_raw_event_map __stop__bpf_raw_tp[];
2277 
bpf_get_raw_tracepoint(const char * name)2278 struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name)
2279 {
2280 	struct bpf_raw_event_map *btp = __start__bpf_raw_tp;
2281 
2282 	for (; btp < __stop__bpf_raw_tp; btp++) {
2283 		if (!strcmp(btp->tp->name, name))
2284 			return btp;
2285 	}
2286 
2287 	return bpf_get_raw_tracepoint_module(name);
2288 }
2289 
bpf_put_raw_tracepoint(struct bpf_raw_event_map * btp)2290 void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp)
2291 {
2292 	struct module *mod;
2293 
2294 	preempt_disable();
2295 	mod = __module_address((unsigned long)btp);
2296 	module_put(mod);
2297 	preempt_enable();
2298 }
2299 
2300 static __always_inline
__bpf_trace_run(struct bpf_prog * prog,u64 * args)2301 void __bpf_trace_run(struct bpf_prog *prog, u64 *args)
2302 {
2303 	cant_sleep();
2304 	if (unlikely(this_cpu_inc_return(*(prog->active)) != 1)) {
2305 		bpf_prog_inc_misses_counter(prog);
2306 		goto out;
2307 	}
2308 	rcu_read_lock();
2309 	(void) bpf_prog_run(prog, args);
2310 	rcu_read_unlock();
2311 out:
2312 	this_cpu_dec(*(prog->active));
2313 }
2314 
2315 #define UNPACK(...)			__VA_ARGS__
2316 #define REPEAT_1(FN, DL, X, ...)	FN(X)
2317 #define REPEAT_2(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__)
2318 #define REPEAT_3(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_2(FN, DL, __VA_ARGS__)
2319 #define REPEAT_4(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_3(FN, DL, __VA_ARGS__)
2320 #define REPEAT_5(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_4(FN, DL, __VA_ARGS__)
2321 #define REPEAT_6(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_5(FN, DL, __VA_ARGS__)
2322 #define REPEAT_7(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_6(FN, DL, __VA_ARGS__)
2323 #define REPEAT_8(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_7(FN, DL, __VA_ARGS__)
2324 #define REPEAT_9(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_8(FN, DL, __VA_ARGS__)
2325 #define REPEAT_10(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_9(FN, DL, __VA_ARGS__)
2326 #define REPEAT_11(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_10(FN, DL, __VA_ARGS__)
2327 #define REPEAT_12(FN, DL, X, ...)	FN(X) UNPACK DL REPEAT_11(FN, DL, __VA_ARGS__)
2328 #define REPEAT(X, FN, DL, ...)		REPEAT_##X(FN, DL, __VA_ARGS__)
2329 
2330 #define SARG(X)		u64 arg##X
2331 #define COPY(X)		args[X] = arg##X
2332 
2333 #define __DL_COM	(,)
2334 #define __DL_SEM	(;)
2335 
2336 #define __SEQ_0_11	0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11
2337 
2338 #define BPF_TRACE_DEFN_x(x)						\
2339 	void bpf_trace_run##x(struct bpf_prog *prog,			\
2340 			      REPEAT(x, SARG, __DL_COM, __SEQ_0_11))	\
2341 	{								\
2342 		u64 args[x];						\
2343 		REPEAT(x, COPY, __DL_SEM, __SEQ_0_11);			\
2344 		__bpf_trace_run(prog, args);				\
2345 	}								\
2346 	EXPORT_SYMBOL_GPL(bpf_trace_run##x)
2347 BPF_TRACE_DEFN_x(1);
2348 BPF_TRACE_DEFN_x(2);
2349 BPF_TRACE_DEFN_x(3);
2350 BPF_TRACE_DEFN_x(4);
2351 BPF_TRACE_DEFN_x(5);
2352 BPF_TRACE_DEFN_x(6);
2353 BPF_TRACE_DEFN_x(7);
2354 BPF_TRACE_DEFN_x(8);
2355 BPF_TRACE_DEFN_x(9);
2356 BPF_TRACE_DEFN_x(10);
2357 BPF_TRACE_DEFN_x(11);
2358 BPF_TRACE_DEFN_x(12);
2359 
__bpf_probe_register(struct bpf_raw_event_map * btp,struct bpf_prog * prog)2360 static int __bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog)
2361 {
2362 	struct tracepoint *tp = btp->tp;
2363 
2364 	/*
2365 	 * check that program doesn't access arguments beyond what's
2366 	 * available in this tracepoint
2367 	 */
2368 	if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64))
2369 		return -EINVAL;
2370 
2371 	if (prog->aux->max_tp_access > btp->writable_size)
2372 		return -EINVAL;
2373 
2374 	return tracepoint_probe_register_may_exist(tp, (void *)btp->bpf_func,
2375 						   prog);
2376 }
2377 
bpf_probe_register(struct bpf_raw_event_map * btp,struct bpf_prog * prog)2378 int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog)
2379 {
2380 	return __bpf_probe_register(btp, prog);
2381 }
2382 
bpf_probe_unregister(struct bpf_raw_event_map * btp,struct bpf_prog * prog)2383 int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_prog *prog)
2384 {
2385 	return tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, prog);
2386 }
2387 
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)2388 int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id,
2389 			    u32 *fd_type, const char **buf,
2390 			    u64 *probe_offset, u64 *probe_addr)
2391 {
2392 	bool is_tracepoint, is_syscall_tp;
2393 	struct bpf_prog *prog;
2394 	int flags, err = 0;
2395 
2396 	prog = event->prog;
2397 	if (!prog)
2398 		return -ENOENT;
2399 
2400 	/* not supporting BPF_PROG_TYPE_PERF_EVENT yet */
2401 	if (prog->type == BPF_PROG_TYPE_PERF_EVENT)
2402 		return -EOPNOTSUPP;
2403 
2404 	*prog_id = prog->aux->id;
2405 	flags = event->tp_event->flags;
2406 	is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT;
2407 	is_syscall_tp = is_syscall_trace_event(event->tp_event);
2408 
2409 	if (is_tracepoint || is_syscall_tp) {
2410 		*buf = is_tracepoint ? event->tp_event->tp->name
2411 				     : event->tp_event->name;
2412 		/* We allow NULL pointer for tracepoint */
2413 		if (fd_type)
2414 			*fd_type = BPF_FD_TYPE_TRACEPOINT;
2415 		if (probe_offset)
2416 			*probe_offset = 0x0;
2417 		if (probe_addr)
2418 			*probe_addr = 0x0;
2419 	} else {
2420 		/* kprobe/uprobe */
2421 		err = -EOPNOTSUPP;
2422 #ifdef CONFIG_KPROBE_EVENTS
2423 		if (flags & TRACE_EVENT_FL_KPROBE)
2424 			err = bpf_get_kprobe_info(event, fd_type, buf,
2425 						  probe_offset, probe_addr,
2426 						  event->attr.type == PERF_TYPE_TRACEPOINT);
2427 #endif
2428 #ifdef CONFIG_UPROBE_EVENTS
2429 		if (flags & TRACE_EVENT_FL_UPROBE)
2430 			err = bpf_get_uprobe_info(event, fd_type, buf,
2431 						  probe_offset, probe_addr,
2432 						  event->attr.type == PERF_TYPE_TRACEPOINT);
2433 #endif
2434 	}
2435 
2436 	return err;
2437 }
2438 
send_signal_irq_work_init(void)2439 static int __init send_signal_irq_work_init(void)
2440 {
2441 	int cpu;
2442 	struct send_signal_irq_work *work;
2443 
2444 	for_each_possible_cpu(cpu) {
2445 		work = per_cpu_ptr(&send_signal_work, cpu);
2446 		init_irq_work(&work->irq_work, do_bpf_send_signal);
2447 	}
2448 	return 0;
2449 }
2450 
2451 subsys_initcall(send_signal_irq_work_init);
2452 
2453 #ifdef CONFIG_MODULES
bpf_event_notify(struct notifier_block * nb,unsigned long op,void * module)2454 static int bpf_event_notify(struct notifier_block *nb, unsigned long op,
2455 			    void *module)
2456 {
2457 	struct bpf_trace_module *btm, *tmp;
2458 	struct module *mod = module;
2459 	int ret = 0;
2460 
2461 	if (mod->num_bpf_raw_events == 0 ||
2462 	    (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING))
2463 		goto out;
2464 
2465 	mutex_lock(&bpf_module_mutex);
2466 
2467 	switch (op) {
2468 	case MODULE_STATE_COMING:
2469 		btm = kzalloc(sizeof(*btm), GFP_KERNEL);
2470 		if (btm) {
2471 			btm->module = module;
2472 			list_add(&btm->list, &bpf_trace_modules);
2473 		} else {
2474 			ret = -ENOMEM;
2475 		}
2476 		break;
2477 	case MODULE_STATE_GOING:
2478 		list_for_each_entry_safe(btm, tmp, &bpf_trace_modules, list) {
2479 			if (btm->module == module) {
2480 				list_del(&btm->list);
2481 				kfree(btm);
2482 				break;
2483 			}
2484 		}
2485 		break;
2486 	}
2487 
2488 	mutex_unlock(&bpf_module_mutex);
2489 
2490 out:
2491 	return notifier_from_errno(ret);
2492 }
2493 
2494 static struct notifier_block bpf_module_nb = {
2495 	.notifier_call = bpf_event_notify,
2496 };
2497 
bpf_event_init(void)2498 static int __init bpf_event_init(void)
2499 {
2500 	register_module_notifier(&bpf_module_nb);
2501 	return 0;
2502 }
2503 
2504 fs_initcall(bpf_event_init);
2505 #endif /* CONFIG_MODULES */
2506 
2507 #ifdef CONFIG_FPROBE
2508 struct bpf_kprobe_multi_link {
2509 	struct bpf_link link;
2510 	struct fprobe fp;
2511 	unsigned long *addrs;
2512 	u64 *cookies;
2513 	u32 cnt;
2514 	u32 mods_cnt;
2515 	struct module **mods;
2516 	u32 flags;
2517 };
2518 
2519 struct bpf_kprobe_multi_run_ctx {
2520 	struct bpf_run_ctx run_ctx;
2521 	struct bpf_kprobe_multi_link *link;
2522 	unsigned long entry_ip;
2523 };
2524 
2525 struct user_syms {
2526 	const char **syms;
2527 	char *buf;
2528 };
2529 
copy_user_syms(struct user_syms * us,unsigned long __user * usyms,u32 cnt)2530 static int copy_user_syms(struct user_syms *us, unsigned long __user *usyms, u32 cnt)
2531 {
2532 	unsigned long __user usymbol;
2533 	const char **syms = NULL;
2534 	char *buf = NULL, *p;
2535 	int err = -ENOMEM;
2536 	unsigned int i;
2537 
2538 	syms = kvmalloc_array(cnt, sizeof(*syms), GFP_KERNEL);
2539 	if (!syms)
2540 		goto error;
2541 
2542 	buf = kvmalloc_array(cnt, KSYM_NAME_LEN, GFP_KERNEL);
2543 	if (!buf)
2544 		goto error;
2545 
2546 	for (p = buf, i = 0; i < cnt; i++) {
2547 		if (__get_user(usymbol, usyms + i)) {
2548 			err = -EFAULT;
2549 			goto error;
2550 		}
2551 		err = strncpy_from_user(p, (const char __user *) usymbol, KSYM_NAME_LEN);
2552 		if (err == KSYM_NAME_LEN)
2553 			err = -E2BIG;
2554 		if (err < 0)
2555 			goto error;
2556 		syms[i] = p;
2557 		p += err + 1;
2558 	}
2559 
2560 	us->syms = syms;
2561 	us->buf = buf;
2562 	return 0;
2563 
2564 error:
2565 	if (err) {
2566 		kvfree(syms);
2567 		kvfree(buf);
2568 	}
2569 	return err;
2570 }
2571 
kprobe_multi_put_modules(struct module ** mods,u32 cnt)2572 static void kprobe_multi_put_modules(struct module **mods, u32 cnt)
2573 {
2574 	u32 i;
2575 
2576 	for (i = 0; i < cnt; i++)
2577 		module_put(mods[i]);
2578 }
2579 
free_user_syms(struct user_syms * us)2580 static void free_user_syms(struct user_syms *us)
2581 {
2582 	kvfree(us->syms);
2583 	kvfree(us->buf);
2584 }
2585 
bpf_kprobe_multi_link_release(struct bpf_link * link)2586 static void bpf_kprobe_multi_link_release(struct bpf_link *link)
2587 {
2588 	struct bpf_kprobe_multi_link *kmulti_link;
2589 
2590 	kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);
2591 	unregister_fprobe(&kmulti_link->fp);
2592 	kprobe_multi_put_modules(kmulti_link->mods, kmulti_link->mods_cnt);
2593 }
2594 
bpf_kprobe_multi_link_dealloc(struct bpf_link * link)2595 static void bpf_kprobe_multi_link_dealloc(struct bpf_link *link)
2596 {
2597 	struct bpf_kprobe_multi_link *kmulti_link;
2598 
2599 	kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);
2600 	kvfree(kmulti_link->addrs);
2601 	kvfree(kmulti_link->cookies);
2602 	kfree(kmulti_link->mods);
2603 	kfree(kmulti_link);
2604 }
2605 
bpf_kprobe_multi_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)2606 static int bpf_kprobe_multi_link_fill_link_info(const struct bpf_link *link,
2607 						struct bpf_link_info *info)
2608 {
2609 	u64 __user *uaddrs = u64_to_user_ptr(info->kprobe_multi.addrs);
2610 	struct bpf_kprobe_multi_link *kmulti_link;
2611 	u32 ucount = info->kprobe_multi.count;
2612 	int err = 0, i;
2613 
2614 	if (!uaddrs ^ !ucount)
2615 		return -EINVAL;
2616 
2617 	kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);
2618 	info->kprobe_multi.count = kmulti_link->cnt;
2619 	info->kprobe_multi.flags = kmulti_link->flags;
2620 
2621 	if (!uaddrs)
2622 		return 0;
2623 	if (ucount < kmulti_link->cnt)
2624 		err = -ENOSPC;
2625 	else
2626 		ucount = kmulti_link->cnt;
2627 
2628 	if (kallsyms_show_value(current_cred())) {
2629 		if (copy_to_user(uaddrs, kmulti_link->addrs, ucount * sizeof(u64)))
2630 			return -EFAULT;
2631 	} else {
2632 		for (i = 0; i < ucount; i++) {
2633 			if (put_user(0, uaddrs + i))
2634 				return -EFAULT;
2635 		}
2636 	}
2637 	return err;
2638 }
2639 
2640 static const struct bpf_link_ops bpf_kprobe_multi_link_lops = {
2641 	.release = bpf_kprobe_multi_link_release,
2642 	.dealloc_deferred = bpf_kprobe_multi_link_dealloc,
2643 	.fill_link_info = bpf_kprobe_multi_link_fill_link_info,
2644 };
2645 
bpf_kprobe_multi_cookie_swap(void * a,void * b,int size,const void * priv)2646 static void bpf_kprobe_multi_cookie_swap(void *a, void *b, int size, const void *priv)
2647 {
2648 	const struct bpf_kprobe_multi_link *link = priv;
2649 	unsigned long *addr_a = a, *addr_b = b;
2650 	u64 *cookie_a, *cookie_b;
2651 
2652 	cookie_a = link->cookies + (addr_a - link->addrs);
2653 	cookie_b = link->cookies + (addr_b - link->addrs);
2654 
2655 	/* swap addr_a/addr_b and cookie_a/cookie_b values */
2656 	swap(*addr_a, *addr_b);
2657 	swap(*cookie_a, *cookie_b);
2658 }
2659 
bpf_kprobe_multi_addrs_cmp(const void * a,const void * b)2660 static int bpf_kprobe_multi_addrs_cmp(const void *a, const void *b)
2661 {
2662 	const unsigned long *addr_a = a, *addr_b = b;
2663 
2664 	if (*addr_a == *addr_b)
2665 		return 0;
2666 	return *addr_a < *addr_b ? -1 : 1;
2667 }
2668 
bpf_kprobe_multi_cookie_cmp(const void * a,const void * b,const void * priv)2669 static int bpf_kprobe_multi_cookie_cmp(const void *a, const void *b, const void *priv)
2670 {
2671 	return bpf_kprobe_multi_addrs_cmp(a, b);
2672 }
2673 
bpf_kprobe_multi_cookie(struct bpf_run_ctx * ctx)2674 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx)
2675 {
2676 	struct bpf_kprobe_multi_run_ctx *run_ctx;
2677 	struct bpf_kprobe_multi_link *link;
2678 	u64 *cookie, entry_ip;
2679 	unsigned long *addr;
2680 
2681 	if (WARN_ON_ONCE(!ctx))
2682 		return 0;
2683 	run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, run_ctx);
2684 	link = run_ctx->link;
2685 	if (!link->cookies)
2686 		return 0;
2687 	entry_ip = run_ctx->entry_ip;
2688 	addr = bsearch(&entry_ip, link->addrs, link->cnt, sizeof(entry_ip),
2689 		       bpf_kprobe_multi_addrs_cmp);
2690 	if (!addr)
2691 		return 0;
2692 	cookie = link->cookies + (addr - link->addrs);
2693 	return *cookie;
2694 }
2695 
bpf_kprobe_multi_entry_ip(struct bpf_run_ctx * ctx)2696 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
2697 {
2698 	struct bpf_kprobe_multi_run_ctx *run_ctx;
2699 
2700 	run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, run_ctx);
2701 	return run_ctx->entry_ip;
2702 }
2703 
2704 static int
kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link * link,unsigned long entry_ip,struct pt_regs * regs)2705 kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link,
2706 			   unsigned long entry_ip, struct pt_regs *regs)
2707 {
2708 	struct bpf_kprobe_multi_run_ctx run_ctx = {
2709 		.link = link,
2710 		.entry_ip = entry_ip,
2711 	};
2712 	struct bpf_run_ctx *old_run_ctx;
2713 	int err;
2714 
2715 	if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) {
2716 		err = 0;
2717 		goto out;
2718 	}
2719 
2720 	migrate_disable();
2721 	rcu_read_lock();
2722 	old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx);
2723 	err = bpf_prog_run(link->link.prog, regs);
2724 	bpf_reset_run_ctx(old_run_ctx);
2725 	rcu_read_unlock();
2726 	migrate_enable();
2727 
2728  out:
2729 	__this_cpu_dec(bpf_prog_active);
2730 	return err;
2731 }
2732 
2733 static int
kprobe_multi_link_handler(struct fprobe * fp,unsigned long fentry_ip,unsigned long ret_ip,struct pt_regs * regs,void * data)2734 kprobe_multi_link_handler(struct fprobe *fp, unsigned long fentry_ip,
2735 			  unsigned long ret_ip, struct pt_regs *regs,
2736 			  void *data)
2737 {
2738 	struct bpf_kprobe_multi_link *link;
2739 
2740 	link = container_of(fp, struct bpf_kprobe_multi_link, fp);
2741 	kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), regs);
2742 	return 0;
2743 }
2744 
2745 static void
kprobe_multi_link_exit_handler(struct fprobe * fp,unsigned long fentry_ip,unsigned long ret_ip,struct pt_regs * regs,void * data)2746 kprobe_multi_link_exit_handler(struct fprobe *fp, unsigned long fentry_ip,
2747 			       unsigned long ret_ip, struct pt_regs *regs,
2748 			       void *data)
2749 {
2750 	struct bpf_kprobe_multi_link *link;
2751 
2752 	link = container_of(fp, struct bpf_kprobe_multi_link, fp);
2753 	kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), regs);
2754 }
2755 
symbols_cmp_r(const void * a,const void * b,const void * priv)2756 static int symbols_cmp_r(const void *a, const void *b, const void *priv)
2757 {
2758 	const char **str_a = (const char **) a;
2759 	const char **str_b = (const char **) b;
2760 
2761 	return strcmp(*str_a, *str_b);
2762 }
2763 
2764 struct multi_symbols_sort {
2765 	const char **funcs;
2766 	u64 *cookies;
2767 };
2768 
symbols_swap_r(void * a,void * b,int size,const void * priv)2769 static void symbols_swap_r(void *a, void *b, int size, const void *priv)
2770 {
2771 	const struct multi_symbols_sort *data = priv;
2772 	const char **name_a = a, **name_b = b;
2773 
2774 	swap(*name_a, *name_b);
2775 
2776 	/* If defined, swap also related cookies. */
2777 	if (data->cookies) {
2778 		u64 *cookie_a, *cookie_b;
2779 
2780 		cookie_a = data->cookies + (name_a - data->funcs);
2781 		cookie_b = data->cookies + (name_b - data->funcs);
2782 		swap(*cookie_a, *cookie_b);
2783 	}
2784 }
2785 
2786 struct modules_array {
2787 	struct module **mods;
2788 	int mods_cnt;
2789 	int mods_cap;
2790 };
2791 
add_module(struct modules_array * arr,struct module * mod)2792 static int add_module(struct modules_array *arr, struct module *mod)
2793 {
2794 	struct module **mods;
2795 
2796 	if (arr->mods_cnt == arr->mods_cap) {
2797 		arr->mods_cap = max(16, arr->mods_cap * 3 / 2);
2798 		mods = krealloc_array(arr->mods, arr->mods_cap, sizeof(*mods), GFP_KERNEL);
2799 		if (!mods)
2800 			return -ENOMEM;
2801 		arr->mods = mods;
2802 	}
2803 
2804 	arr->mods[arr->mods_cnt] = mod;
2805 	arr->mods_cnt++;
2806 	return 0;
2807 }
2808 
has_module(struct modules_array * arr,struct module * mod)2809 static bool has_module(struct modules_array *arr, struct module *mod)
2810 {
2811 	int i;
2812 
2813 	for (i = arr->mods_cnt - 1; i >= 0; i--) {
2814 		if (arr->mods[i] == mod)
2815 			return true;
2816 	}
2817 	return false;
2818 }
2819 
get_modules_for_addrs(struct module *** mods,unsigned long * addrs,u32 addrs_cnt)2820 static int get_modules_for_addrs(struct module ***mods, unsigned long *addrs, u32 addrs_cnt)
2821 {
2822 	struct modules_array arr = {};
2823 	u32 i, err = 0;
2824 
2825 	for (i = 0; i < addrs_cnt; i++) {
2826 		struct module *mod;
2827 
2828 		preempt_disable();
2829 		mod = __module_address(addrs[i]);
2830 		/* Either no module or we it's already stored  */
2831 		if (!mod || has_module(&arr, mod)) {
2832 			preempt_enable();
2833 			continue;
2834 		}
2835 		if (!try_module_get(mod))
2836 			err = -EINVAL;
2837 		preempt_enable();
2838 		if (err)
2839 			break;
2840 		err = add_module(&arr, mod);
2841 		if (err) {
2842 			module_put(mod);
2843 			break;
2844 		}
2845 	}
2846 
2847 	/* We return either err < 0 in case of error, ... */
2848 	if (err) {
2849 		kprobe_multi_put_modules(arr.mods, arr.mods_cnt);
2850 		kfree(arr.mods);
2851 		return err;
2852 	}
2853 
2854 	/* or number of modules found if everything is ok. */
2855 	*mods = arr.mods;
2856 	return arr.mods_cnt;
2857 }
2858 
addrs_check_error_injection_list(unsigned long * addrs,u32 cnt)2859 static int addrs_check_error_injection_list(unsigned long *addrs, u32 cnt)
2860 {
2861 	u32 i;
2862 
2863 	for (i = 0; i < cnt; i++) {
2864 		if (!within_error_injection_list(addrs[i]))
2865 			return -EINVAL;
2866 	}
2867 	return 0;
2868 }
2869 
bpf_kprobe_multi_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)2870 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
2871 {
2872 	struct bpf_kprobe_multi_link *link = NULL;
2873 	struct bpf_link_primer link_primer;
2874 	void __user *ucookies;
2875 	unsigned long *addrs;
2876 	u32 flags, cnt, size;
2877 	void __user *uaddrs;
2878 	u64 *cookies = NULL;
2879 	void __user *usyms;
2880 	int err;
2881 
2882 	/* no support for 32bit archs yet */
2883 	if (sizeof(u64) != sizeof(void *))
2884 		return -EOPNOTSUPP;
2885 
2886 	if (prog->expected_attach_type != BPF_TRACE_KPROBE_MULTI)
2887 		return -EINVAL;
2888 
2889 	flags = attr->link_create.kprobe_multi.flags;
2890 	if (flags & ~BPF_F_KPROBE_MULTI_RETURN)
2891 		return -EINVAL;
2892 
2893 	uaddrs = u64_to_user_ptr(attr->link_create.kprobe_multi.addrs);
2894 	usyms = u64_to_user_ptr(attr->link_create.kprobe_multi.syms);
2895 	if (!!uaddrs == !!usyms)
2896 		return -EINVAL;
2897 
2898 	cnt = attr->link_create.kprobe_multi.cnt;
2899 	if (!cnt)
2900 		return -EINVAL;
2901 	if (cnt > MAX_KPROBE_MULTI_CNT)
2902 		return -E2BIG;
2903 
2904 	size = cnt * sizeof(*addrs);
2905 	addrs = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL);
2906 	if (!addrs)
2907 		return -ENOMEM;
2908 
2909 	ucookies = u64_to_user_ptr(attr->link_create.kprobe_multi.cookies);
2910 	if (ucookies) {
2911 		cookies = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL);
2912 		if (!cookies) {
2913 			err = -ENOMEM;
2914 			goto error;
2915 		}
2916 		if (copy_from_user(cookies, ucookies, size)) {
2917 			err = -EFAULT;
2918 			goto error;
2919 		}
2920 	}
2921 
2922 	if (uaddrs) {
2923 		if (copy_from_user(addrs, uaddrs, size)) {
2924 			err = -EFAULT;
2925 			goto error;
2926 		}
2927 	} else {
2928 		struct multi_symbols_sort data = {
2929 			.cookies = cookies,
2930 		};
2931 		struct user_syms us;
2932 
2933 		err = copy_user_syms(&us, usyms, cnt);
2934 		if (err)
2935 			goto error;
2936 
2937 		if (cookies)
2938 			data.funcs = us.syms;
2939 
2940 		sort_r(us.syms, cnt, sizeof(*us.syms), symbols_cmp_r,
2941 		       symbols_swap_r, &data);
2942 
2943 		err = ftrace_lookup_symbols(us.syms, cnt, addrs);
2944 		free_user_syms(&us);
2945 		if (err)
2946 			goto error;
2947 	}
2948 
2949 	if (prog->kprobe_override && addrs_check_error_injection_list(addrs, cnt)) {
2950 		err = -EINVAL;
2951 		goto error;
2952 	}
2953 
2954 	link = kzalloc(sizeof(*link), GFP_KERNEL);
2955 	if (!link) {
2956 		err = -ENOMEM;
2957 		goto error;
2958 	}
2959 
2960 	bpf_link_init(&link->link, BPF_LINK_TYPE_KPROBE_MULTI,
2961 		      &bpf_kprobe_multi_link_lops, prog);
2962 
2963 	err = bpf_link_prime(&link->link, &link_primer);
2964 	if (err)
2965 		goto error;
2966 
2967 	if (flags & BPF_F_KPROBE_MULTI_RETURN)
2968 		link->fp.exit_handler = kprobe_multi_link_exit_handler;
2969 	else
2970 		link->fp.entry_handler = kprobe_multi_link_handler;
2971 
2972 	link->addrs = addrs;
2973 	link->cookies = cookies;
2974 	link->cnt = cnt;
2975 	link->flags = flags;
2976 
2977 	if (cookies) {
2978 		/*
2979 		 * Sorting addresses will trigger sorting cookies as well
2980 		 * (check bpf_kprobe_multi_cookie_swap). This way we can
2981 		 * find cookie based on the address in bpf_get_attach_cookie
2982 		 * helper.
2983 		 */
2984 		sort_r(addrs, cnt, sizeof(*addrs),
2985 		       bpf_kprobe_multi_cookie_cmp,
2986 		       bpf_kprobe_multi_cookie_swap,
2987 		       link);
2988 	}
2989 
2990 	err = get_modules_for_addrs(&link->mods, addrs, cnt);
2991 	if (err < 0) {
2992 		bpf_link_cleanup(&link_primer);
2993 		return err;
2994 	}
2995 	link->mods_cnt = err;
2996 
2997 	err = register_fprobe_ips(&link->fp, addrs, cnt);
2998 	if (err) {
2999 		kprobe_multi_put_modules(link->mods, link->mods_cnt);
3000 		bpf_link_cleanup(&link_primer);
3001 		return err;
3002 	}
3003 
3004 	return bpf_link_settle(&link_primer);
3005 
3006 error:
3007 	kfree(link);
3008 	kvfree(addrs);
3009 	kvfree(cookies);
3010 	return err;
3011 }
3012 #else /* !CONFIG_FPROBE */
bpf_kprobe_multi_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)3013 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
3014 {
3015 	return -EOPNOTSUPP;
3016 }
bpf_kprobe_multi_cookie(struct bpf_run_ctx * ctx)3017 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx)
3018 {
3019 	return 0;
3020 }
bpf_kprobe_multi_entry_ip(struct bpf_run_ctx * ctx)3021 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
3022 {
3023 	return 0;
3024 }
3025 #endif
3026 
3027 #ifdef CONFIG_UPROBES
3028 struct bpf_uprobe_multi_link;
3029 
3030 struct bpf_uprobe {
3031 	struct bpf_uprobe_multi_link *link;
3032 	loff_t offset;
3033 	unsigned long ref_ctr_offset;
3034 	u64 cookie;
3035 	struct uprobe_consumer consumer;
3036 };
3037 
3038 struct bpf_uprobe_multi_link {
3039 	struct path path;
3040 	struct bpf_link link;
3041 	u32 cnt;
3042 	struct bpf_uprobe *uprobes;
3043 	struct task_struct *task;
3044 };
3045 
3046 struct bpf_uprobe_multi_run_ctx {
3047 	struct bpf_run_ctx run_ctx;
3048 	unsigned long entry_ip;
3049 	struct bpf_uprobe *uprobe;
3050 };
3051 
bpf_uprobe_unregister(struct path * path,struct bpf_uprobe * uprobes,u32 cnt)3052 static void bpf_uprobe_unregister(struct path *path, struct bpf_uprobe *uprobes,
3053 				  u32 cnt)
3054 {
3055 	u32 i;
3056 
3057 	for (i = 0; i < cnt; i++) {
3058 		uprobe_unregister(d_real_inode(path->dentry), uprobes[i].offset,
3059 				  &uprobes[i].consumer);
3060 	}
3061 }
3062 
bpf_uprobe_multi_link_release(struct bpf_link * link)3063 static void bpf_uprobe_multi_link_release(struct bpf_link *link)
3064 {
3065 	struct bpf_uprobe_multi_link *umulti_link;
3066 
3067 	umulti_link = container_of(link, struct bpf_uprobe_multi_link, link);
3068 	bpf_uprobe_unregister(&umulti_link->path, umulti_link->uprobes, umulti_link->cnt);
3069 	if (umulti_link->task)
3070 		put_task_struct(umulti_link->task);
3071 	path_put(&umulti_link->path);
3072 }
3073 
bpf_uprobe_multi_link_dealloc(struct bpf_link * link)3074 static void bpf_uprobe_multi_link_dealloc(struct bpf_link *link)
3075 {
3076 	struct bpf_uprobe_multi_link *umulti_link;
3077 
3078 	umulti_link = container_of(link, struct bpf_uprobe_multi_link, link);
3079 	kvfree(umulti_link->uprobes);
3080 	kfree(umulti_link);
3081 }
3082 
3083 static const struct bpf_link_ops bpf_uprobe_multi_link_lops = {
3084 	.release = bpf_uprobe_multi_link_release,
3085 	.dealloc_deferred = bpf_uprobe_multi_link_dealloc,
3086 };
3087 
uprobe_prog_run(struct bpf_uprobe * uprobe,unsigned long entry_ip,struct pt_regs * regs)3088 static int uprobe_prog_run(struct bpf_uprobe *uprobe,
3089 			   unsigned long entry_ip,
3090 			   struct pt_regs *regs)
3091 {
3092 	struct bpf_uprobe_multi_link *link = uprobe->link;
3093 	struct bpf_uprobe_multi_run_ctx run_ctx = {
3094 		.entry_ip = entry_ip,
3095 		.uprobe = uprobe,
3096 	};
3097 	struct bpf_prog *prog = link->link.prog;
3098 	bool sleepable = prog->aux->sleepable;
3099 	struct bpf_run_ctx *old_run_ctx;
3100 	int err = 0;
3101 
3102 	if (link->task && current->mm != link->task->mm)
3103 		return 0;
3104 
3105 	if (sleepable)
3106 		rcu_read_lock_trace();
3107 	else
3108 		rcu_read_lock();
3109 
3110 	migrate_disable();
3111 
3112 	old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx);
3113 	err = bpf_prog_run(link->link.prog, regs);
3114 	bpf_reset_run_ctx(old_run_ctx);
3115 
3116 	migrate_enable();
3117 
3118 	if (sleepable)
3119 		rcu_read_unlock_trace();
3120 	else
3121 		rcu_read_unlock();
3122 	return err;
3123 }
3124 
3125 static bool
uprobe_multi_link_filter(struct uprobe_consumer * con,enum uprobe_filter_ctx ctx,struct mm_struct * mm)3126 uprobe_multi_link_filter(struct uprobe_consumer *con, enum uprobe_filter_ctx ctx,
3127 			 struct mm_struct *mm)
3128 {
3129 	struct bpf_uprobe *uprobe;
3130 
3131 	uprobe = container_of(con, struct bpf_uprobe, consumer);
3132 	return uprobe->link->task->mm == mm;
3133 }
3134 
3135 static int
uprobe_multi_link_handler(struct uprobe_consumer * con,struct pt_regs * regs)3136 uprobe_multi_link_handler(struct uprobe_consumer *con, struct pt_regs *regs)
3137 {
3138 	struct bpf_uprobe *uprobe;
3139 
3140 	uprobe = container_of(con, struct bpf_uprobe, consumer);
3141 	return uprobe_prog_run(uprobe, instruction_pointer(regs), regs);
3142 }
3143 
3144 static int
uprobe_multi_link_ret_handler(struct uprobe_consumer * con,unsigned long func,struct pt_regs * regs)3145 uprobe_multi_link_ret_handler(struct uprobe_consumer *con, unsigned long func, struct pt_regs *regs)
3146 {
3147 	struct bpf_uprobe *uprobe;
3148 
3149 	uprobe = container_of(con, struct bpf_uprobe, consumer);
3150 	return uprobe_prog_run(uprobe, func, regs);
3151 }
3152 
bpf_uprobe_multi_entry_ip(struct bpf_run_ctx * ctx)3153 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
3154 {
3155 	struct bpf_uprobe_multi_run_ctx *run_ctx;
3156 
3157 	run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx, run_ctx);
3158 	return run_ctx->entry_ip;
3159 }
3160 
bpf_uprobe_multi_cookie(struct bpf_run_ctx * ctx)3161 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx)
3162 {
3163 	struct bpf_uprobe_multi_run_ctx *run_ctx;
3164 
3165 	run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx, run_ctx);
3166 	return run_ctx->uprobe->cookie;
3167 }
3168 
bpf_uprobe_multi_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)3169 int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
3170 {
3171 	struct bpf_uprobe_multi_link *link = NULL;
3172 	unsigned long __user *uref_ctr_offsets;
3173 	struct bpf_link_primer link_primer;
3174 	struct bpf_uprobe *uprobes = NULL;
3175 	struct task_struct *task = NULL;
3176 	unsigned long __user *uoffsets;
3177 	u64 __user *ucookies;
3178 	void __user *upath;
3179 	u32 flags, cnt, i;
3180 	struct path path;
3181 	char *name;
3182 	pid_t pid;
3183 	int err;
3184 
3185 	/* no support for 32bit archs yet */
3186 	if (sizeof(u64) != sizeof(void *))
3187 		return -EOPNOTSUPP;
3188 
3189 	if (prog->expected_attach_type != BPF_TRACE_UPROBE_MULTI)
3190 		return -EINVAL;
3191 
3192 	flags = attr->link_create.uprobe_multi.flags;
3193 	if (flags & ~BPF_F_UPROBE_MULTI_RETURN)
3194 		return -EINVAL;
3195 
3196 	/*
3197 	 * path, offsets and cnt are mandatory,
3198 	 * ref_ctr_offsets and cookies are optional
3199 	 */
3200 	upath = u64_to_user_ptr(attr->link_create.uprobe_multi.path);
3201 	uoffsets = u64_to_user_ptr(attr->link_create.uprobe_multi.offsets);
3202 	cnt = attr->link_create.uprobe_multi.cnt;
3203 	pid = attr->link_create.uprobe_multi.pid;
3204 
3205 	if (!upath || !uoffsets || !cnt || pid < 0)
3206 		return -EINVAL;
3207 	if (cnt > MAX_UPROBE_MULTI_CNT)
3208 		return -E2BIG;
3209 
3210 	uref_ctr_offsets = u64_to_user_ptr(attr->link_create.uprobe_multi.ref_ctr_offsets);
3211 	ucookies = u64_to_user_ptr(attr->link_create.uprobe_multi.cookies);
3212 
3213 	name = strndup_user(upath, PATH_MAX);
3214 	if (IS_ERR(name)) {
3215 		err = PTR_ERR(name);
3216 		return err;
3217 	}
3218 
3219 	err = kern_path(name, LOOKUP_FOLLOW, &path);
3220 	kfree(name);
3221 	if (err)
3222 		return err;
3223 
3224 	if (!d_is_reg(path.dentry)) {
3225 		err = -EBADF;
3226 		goto error_path_put;
3227 	}
3228 
3229 	if (pid) {
3230 		rcu_read_lock();
3231 		task = get_pid_task(find_vpid(pid), PIDTYPE_TGID);
3232 		rcu_read_unlock();
3233 		if (!task) {
3234 			err = -ESRCH;
3235 			goto error_path_put;
3236 		}
3237 	}
3238 
3239 	err = -ENOMEM;
3240 
3241 	link = kzalloc(sizeof(*link), GFP_KERNEL);
3242 	uprobes = kvcalloc(cnt, sizeof(*uprobes), GFP_KERNEL);
3243 
3244 	if (!uprobes || !link)
3245 		goto error_free;
3246 
3247 	for (i = 0; i < cnt; i++) {
3248 		if (ucookies && __get_user(uprobes[i].cookie, ucookies + i)) {
3249 			err = -EFAULT;
3250 			goto error_free;
3251 		}
3252 		if (uref_ctr_offsets && __get_user(uprobes[i].ref_ctr_offset, uref_ctr_offsets + i)) {
3253 			err = -EFAULT;
3254 			goto error_free;
3255 		}
3256 		if (__get_user(uprobes[i].offset, uoffsets + i)) {
3257 			err = -EFAULT;
3258 			goto error_free;
3259 		}
3260 
3261 		uprobes[i].link = link;
3262 
3263 		if (flags & BPF_F_UPROBE_MULTI_RETURN)
3264 			uprobes[i].consumer.ret_handler = uprobe_multi_link_ret_handler;
3265 		else
3266 			uprobes[i].consumer.handler = uprobe_multi_link_handler;
3267 
3268 		if (pid)
3269 			uprobes[i].consumer.filter = uprobe_multi_link_filter;
3270 	}
3271 
3272 	link->cnt = cnt;
3273 	link->uprobes = uprobes;
3274 	link->path = path;
3275 	link->task = task;
3276 
3277 	bpf_link_init(&link->link, BPF_LINK_TYPE_UPROBE_MULTI,
3278 		      &bpf_uprobe_multi_link_lops, prog);
3279 
3280 	for (i = 0; i < cnt; i++) {
3281 		err = uprobe_register_refctr(d_real_inode(link->path.dentry),
3282 					     uprobes[i].offset,
3283 					     uprobes[i].ref_ctr_offset,
3284 					     &uprobes[i].consumer);
3285 		if (err) {
3286 			bpf_uprobe_unregister(&path, uprobes, i);
3287 			goto error_free;
3288 		}
3289 	}
3290 
3291 	err = bpf_link_prime(&link->link, &link_primer);
3292 	if (err)
3293 		goto error_free;
3294 
3295 	return bpf_link_settle(&link_primer);
3296 
3297 error_free:
3298 	kvfree(uprobes);
3299 	kfree(link);
3300 	if (task)
3301 		put_task_struct(task);
3302 error_path_put:
3303 	path_put(&path);
3304 	return err;
3305 }
3306 #else /* !CONFIG_UPROBES */
bpf_uprobe_multi_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)3307 int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
3308 {
3309 	return -EOPNOTSUPP;
3310 }
bpf_uprobe_multi_cookie(struct bpf_run_ctx * ctx)3311 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx)
3312 {
3313 	return 0;
3314 }
bpf_uprobe_multi_entry_ip(struct bpf_run_ctx * ctx)3315 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
3316 {
3317 	return 0;
3318 }
3319 #endif /* CONFIG_UPROBES */
3320