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