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mm, memory_hotplug: try to migrate full pfn range
[linux/fpc-iii.git] / kernel / trace / bpf_trace.c
blob9ddb6fddb4e01b52850ba173d53a24914b4eb4c9
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_perf_event.h>
10 #include <linux/filter.h>
11 #include <linux/uaccess.h>
12 #include <linux/ctype.h>
13 #include <linux/kprobes.h>
14 #include <linux/syscalls.h>
15 #include <linux/error-injection.h>
16
17 #include "trace_probe.h"
18 #include "trace.h"
19
20 #ifdef CONFIG_MODULES
21 struct bpf_trace_module {
22 struct module *module;
23 struct list_head list;
24 };
25
26 static LIST_HEAD(bpf_trace_modules);
27 static DEFINE_MUTEX(bpf_module_mutex);
28
29 static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name)
30 {
31 struct bpf_raw_event_map *btp, *ret = NULL;
32 struct bpf_trace_module *btm;
33 unsigned int i;
34
35 mutex_lock(&bpf_module_mutex);
36 list_for_each_entry(btm, &bpf_trace_modules, list) {
37 for (i = 0; i < btm->module->num_bpf_raw_events; ++i) {
38 btp = &btm->module->bpf_raw_events[i];
39 if (!strcmp(btp->tp->name, name)) {
40 if (try_module_get(btm->module))
41 ret = btp;
42 goto out;
43 }
44 }
45 }
46 out:
47 mutex_unlock(&bpf_module_mutex);
48 return ret;
49 }
50 #else
51 static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name)
52 {
53 return NULL;
54 }
55 #endif /* CONFIG_MODULES */
56
57 u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
58 u64 bpf_get_stack(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
59
60 /**
61 * trace_call_bpf - invoke BPF program
62 * @call: tracepoint event
63 * @ctx: opaque context pointer
64 *
65 * kprobe handlers execute BPF programs via this helper.
66 * Can be used from static tracepoints in the future.
67 *
68 * Return: BPF programs always return an integer which is interpreted by
69 * kprobe handler as:
70 * 0 - return from kprobe (event is filtered out)
71 * 1 - store kprobe event into ring buffer
72 * Other values are reserved and currently alias to 1
73 */
74 unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx)
75 {
76 unsigned int ret;
77
78 if (in_nmi()) /* not supported yet */
79 return 1;
80
81 preempt_disable();
82
83 if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) {
84 /*
85 * since some bpf program is already running on this cpu,
86 * don't call into another bpf program (same or different)
87 * and don't send kprobe event into ring-buffer,
88 * so return zero here
89 */
90 ret = 0;
91 goto out;
92 }
93
94 /*
95 * Instead of moving rcu_read_lock/rcu_dereference/rcu_read_unlock
96 * to all call sites, we did a bpf_prog_array_valid() there to check
97 * whether call->prog_array is empty or not, which is
98 * a heurisitc to speed up execution.
99 *
100 * If bpf_prog_array_valid() fetched prog_array was
101 * non-NULL, we go into trace_call_bpf() and do the actual
102 * proper rcu_dereference() under RCU lock.
103 * If it turns out that prog_array is NULL then, we bail out.
104 * For the opposite, if the bpf_prog_array_valid() fetched pointer
105 * was NULL, you'll skip the prog_array with the risk of missing
106 * out of events when it was updated in between this and the
107 * rcu_dereference() which is accepted risk.
108 */
109 ret = BPF_PROG_RUN_ARRAY_CHECK(call->prog_array, ctx, BPF_PROG_RUN);
110
111 out:
112 __this_cpu_dec(bpf_prog_active);
113 preempt_enable();
114
115 return ret;
116 }
117 EXPORT_SYMBOL_GPL(trace_call_bpf);
118
119 #ifdef CONFIG_BPF_KPROBE_OVERRIDE
120 BPF_CALL_2(bpf_override_return, struct pt_regs *, regs, unsigned long, rc)
121 {
122 regs_set_return_value(regs, rc);
123 override_function_with_return(regs);
124 return 0;
125 }
126
127 static const struct bpf_func_proto bpf_override_return_proto = {
128 .func = bpf_override_return,
129 .gpl_only = true,
130 .ret_type = RET_INTEGER,
131 .arg1_type = ARG_PTR_TO_CTX,
132 .arg2_type = ARG_ANYTHING,
133 };
134 #endif
135
136 BPF_CALL_3(bpf_probe_read, void *, dst, u32, size, const void *, unsafe_ptr)
137 {
138 int ret;
139
140 ret = probe_kernel_read(dst, unsafe_ptr, size);
141 if (unlikely(ret < 0))
142 memset(dst, 0, size);
143
144 return ret;
145 }
146
147 static const struct bpf_func_proto bpf_probe_read_proto = {
148 .func = bpf_probe_read,
149 .gpl_only = true,
150 .ret_type = RET_INTEGER,
151 .arg1_type = ARG_PTR_TO_UNINIT_MEM,
152 .arg2_type = ARG_CONST_SIZE_OR_ZERO,
153 .arg3_type = ARG_ANYTHING,
154 };
155
156 BPF_CALL_3(bpf_probe_write_user, void *, unsafe_ptr, const void *, src,
157 u32, size)
158 {
159 /*
160 * Ensure we're in user context which is safe for the helper to
161 * run. This helper has no business in a kthread.
162 *
163 * access_ok() should prevent writing to non-user memory, but in
164 * some situations (nommu, temporary switch, etc) access_ok() does
165 * not provide enough validation, hence the check on KERNEL_DS.
166 */
167
168 if (unlikely(in_interrupt() ||
169 current->flags & (PF_KTHREAD | PF_EXITING)))
170 return -EPERM;
171 if (unlikely(uaccess_kernel()))
172 return -EPERM;
173 if (!access_ok(VERIFY_WRITE, unsafe_ptr, size))
174 return -EPERM;
175
176 return probe_kernel_write(unsafe_ptr, src, size);
177 }
178
179 static const struct bpf_func_proto bpf_probe_write_user_proto = {
180 .func = bpf_probe_write_user,
181 .gpl_only = true,
182 .ret_type = RET_INTEGER,
183 .arg1_type = ARG_ANYTHING,
184 .arg2_type = ARG_PTR_TO_MEM,
185 .arg3_type = ARG_CONST_SIZE,
186 };
187
188 static const struct bpf_func_proto *bpf_get_probe_write_proto(void)
189 {
190 pr_warn_ratelimited("%s[%d] is installing a program with bpf_probe_write_user helper that may corrupt user memory!",
191 current->comm, task_pid_nr(current));
192
193 return &bpf_probe_write_user_proto;
194 }
195
196 /*
197 * Only limited trace_printk() conversion specifiers allowed:
198 * %d %i %u %x %ld %li %lu %lx %lld %lli %llu %llx %p %s
199 */
200 BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1,
201 u64, arg2, u64, arg3)
202 {
203 bool str_seen = false;
204 int mod[3] = {};
205 int fmt_cnt = 0;
206 u64 unsafe_addr;
207 char buf[64];
208 int i;
209
210 /*
211 * bpf_check()->check_func_arg()->check_stack_boundary()
212 * guarantees that fmt points to bpf program stack,
213 * fmt_size bytes of it were initialized and fmt_size > 0
214 */
215 if (fmt[--fmt_size] != 0)
216 return -EINVAL;
217
218 /* check format string for allowed specifiers */
219 for (i = 0; i < fmt_size; i++) {
220 if ((!isprint(fmt[i]) && !isspace(fmt[i])) || !isascii(fmt[i]))
221 return -EINVAL;
222
223 if (fmt[i] != '%')
224 continue;
225
226 if (fmt_cnt >= 3)
227 return -EINVAL;
228
229 /* fmt[i] != 0 && fmt[last] == 0, so we can access fmt[i + 1] */
230 i++;
231 if (fmt[i] == 'l') {
232 mod[fmt_cnt]++;
233 i++;
234 } else if (fmt[i] == 'p' || fmt[i] == 's') {
235 mod[fmt_cnt]++;
236 /* disallow any further format extensions */
237 if (fmt[i + 1] != 0 &&
238 !isspace(fmt[i + 1]) &&
239 !ispunct(fmt[i + 1]))
240 return -EINVAL;
241 fmt_cnt++;
242 if (fmt[i] == 's') {
243 if (str_seen)
244 /* allow only one '%s' per fmt string */
245 return -EINVAL;
246 str_seen = true;
247
248 switch (fmt_cnt) {
249 case 1:
250 unsafe_addr = arg1;
251 arg1 = (long) buf;
252 break;
253 case 2:
254 unsafe_addr = arg2;
255 arg2 = (long) buf;
256 break;
257 case 3:
258 unsafe_addr = arg3;
259 arg3 = (long) buf;
260 break;
261 }
262 buf[0] = 0;
263 strncpy_from_unsafe(buf,
264 (void *) (long) unsafe_addr,
265 sizeof(buf));
266 }
267 continue;
268 }
269
270 if (fmt[i] == 'l') {
271 mod[fmt_cnt]++;
272 i++;
273 }
274
275 if (fmt[i] != 'i' && fmt[i] != 'd' &&
276 fmt[i] != 'u' && fmt[i] != 'x')
277 return -EINVAL;
278 fmt_cnt++;
279 }
280
281 /* Horrid workaround for getting va_list handling working with different
282 * argument type combinations generically for 32 and 64 bit archs.
283 */
284 #define __BPF_TP_EMIT() __BPF_ARG3_TP()
285 #define __BPF_TP(...) \
286 __trace_printk(0 /* Fake ip */, \
287 fmt, ##__VA_ARGS__)
288
289 #define __BPF_ARG1_TP(...) \
290 ((mod[0] == 2 || (mod[0] == 1 && __BITS_PER_LONG == 64)) \
291 ? __BPF_TP(arg1, ##__VA_ARGS__) \
292 : ((mod[0] == 1 || (mod[0] == 0 && __BITS_PER_LONG == 32)) \
293 ? __BPF_TP((long)arg1, ##__VA_ARGS__) \
294 : __BPF_TP((u32)arg1, ##__VA_ARGS__)))
295
296 #define __BPF_ARG2_TP(...) \
297 ((mod[1] == 2 || (mod[1] == 1 && __BITS_PER_LONG == 64)) \
298 ? __BPF_ARG1_TP(arg2, ##__VA_ARGS__) \
299 : ((mod[1] == 1 || (mod[1] == 0 && __BITS_PER_LONG == 32)) \
300 ? __BPF_ARG1_TP((long)arg2, ##__VA_ARGS__) \
301 : __BPF_ARG1_TP((u32)arg2, ##__VA_ARGS__)))
302
303 #define __BPF_ARG3_TP(...) \
304 ((mod[2] == 2 || (mod[2] == 1 && __BITS_PER_LONG == 64)) \
305 ? __BPF_ARG2_TP(arg3, ##__VA_ARGS__) \
306 : ((mod[2] == 1 || (mod[2] == 0 && __BITS_PER_LONG == 32)) \
307 ? __BPF_ARG2_TP((long)arg3, ##__VA_ARGS__) \
308 : __BPF_ARG2_TP((u32)arg3, ##__VA_ARGS__)))
309
310 return __BPF_TP_EMIT();
311 }
312
313 static const struct bpf_func_proto bpf_trace_printk_proto = {
314 .func = bpf_trace_printk,
315 .gpl_only = true,
316 .ret_type = RET_INTEGER,
317 .arg1_type = ARG_PTR_TO_MEM,
318 .arg2_type = ARG_CONST_SIZE,
319 };
320
321 const struct bpf_func_proto *bpf_get_trace_printk_proto(void)
322 {
323 /*
324 * this program might be calling bpf_trace_printk,
325 * so allocate per-cpu printk buffers
326 */
327 trace_printk_init_buffers();
328
329 return &bpf_trace_printk_proto;
330 }
331
332 static __always_inline int
333 get_map_perf_counter(struct bpf_map *map, u64 flags,
334 u64 *value, u64 *enabled, u64 *running)
335 {
336 struct bpf_array *array = container_of(map, struct bpf_array, map);
337 unsigned int cpu = smp_processor_id();
338 u64 index = flags & BPF_F_INDEX_MASK;
339 struct bpf_event_entry *ee;
340
341 if (unlikely(flags & ~(BPF_F_INDEX_MASK)))
342 return -EINVAL;
343 if (index == BPF_F_CURRENT_CPU)
344 index = cpu;
345 if (unlikely(index >= array->map.max_entries))
346 return -E2BIG;
347
348 ee = READ_ONCE(array->ptrs[index]);
349 if (!ee)
350 return -ENOENT;
351
352 return perf_event_read_local(ee->event, value, enabled, running);
353 }
354
355 BPF_CALL_2(bpf_perf_event_read, struct bpf_map *, map, u64, flags)
356 {
357 u64 value = 0;
358 int err;
359
360 err = get_map_perf_counter(map, flags, &value, NULL, NULL);
361 /*
362 * this api is ugly since we miss [-22..-2] range of valid
363 * counter values, but that's uapi
364 */
365 if (err)
366 return err;
367 return value;
368 }
369
370 static const struct bpf_func_proto bpf_perf_event_read_proto = {
371 .func = bpf_perf_event_read,
372 .gpl_only = true,
373 .ret_type = RET_INTEGER,
374 .arg1_type = ARG_CONST_MAP_PTR,
375 .arg2_type = ARG_ANYTHING,
376 };
377
378 BPF_CALL_4(bpf_perf_event_read_value, struct bpf_map *, map, u64, flags,
379 struct bpf_perf_event_value *, buf, u32, size)
380 {
381 int err = -EINVAL;
382
383 if (unlikely(size != sizeof(struct bpf_perf_event_value)))
384 goto clear;
385 err = get_map_perf_counter(map, flags, &buf->counter, &buf->enabled,
386 &buf->running);
387 if (unlikely(err))
388 goto clear;
389 return 0;
390 clear:
391 memset(buf, 0, size);
392 return err;
393 }
394
395 static const struct bpf_func_proto bpf_perf_event_read_value_proto = {
396 .func = bpf_perf_event_read_value,
397 .gpl_only = true,
398 .ret_type = RET_INTEGER,
399 .arg1_type = ARG_CONST_MAP_PTR,
400 .arg2_type = ARG_ANYTHING,
401 .arg3_type = ARG_PTR_TO_UNINIT_MEM,
402 .arg4_type = ARG_CONST_SIZE,
403 };
404
405 static DEFINE_PER_CPU(struct perf_sample_data, bpf_trace_sd);
406
407 static __always_inline u64
408 __bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map,
409 u64 flags, struct perf_sample_data *sd)
410 {
411 struct bpf_array *array = container_of(map, struct bpf_array, map);
412 unsigned int cpu = smp_processor_id();
413 u64 index = flags & BPF_F_INDEX_MASK;
414 struct bpf_event_entry *ee;
415 struct perf_event *event;
416
417 if (index == BPF_F_CURRENT_CPU)
418 index = cpu;
419 if (unlikely(index >= array->map.max_entries))
420 return -E2BIG;
421
422 ee = READ_ONCE(array->ptrs[index]);
423 if (!ee)
424 return -ENOENT;
425
426 event = ee->event;
427 if (unlikely(event->attr.type != PERF_TYPE_SOFTWARE ||
428 event->attr.config != PERF_COUNT_SW_BPF_OUTPUT))
429 return -EINVAL;
430
431 if (unlikely(event->oncpu != cpu))
432 return -EOPNOTSUPP;
433
434 perf_event_output(event, sd, regs);
435 return 0;
436 }
437
438 BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map,
439 u64, flags, void *, data, u64, size)
440 {
441 struct perf_sample_data *sd = this_cpu_ptr(&bpf_trace_sd);
442 struct perf_raw_record raw = {
443 .frag = {
444 .size = size,
445 .data = data,
446 },
447 };
448
449 if (unlikely(flags & ~(BPF_F_INDEX_MASK)))
450 return -EINVAL;
451
452 perf_sample_data_init(sd, 0, 0);
453 sd->raw = &raw;
454
455 return __bpf_perf_event_output(regs, map, flags, sd);
456 }
457
458 static const struct bpf_func_proto bpf_perf_event_output_proto = {
459 .func = bpf_perf_event_output,
460 .gpl_only = true,
461 .ret_type = RET_INTEGER,
462 .arg1_type = ARG_PTR_TO_CTX,
463 .arg2_type = ARG_CONST_MAP_PTR,
464 .arg3_type = ARG_ANYTHING,
465 .arg4_type = ARG_PTR_TO_MEM,
466 .arg5_type = ARG_CONST_SIZE_OR_ZERO,
467 };
468
469 static DEFINE_PER_CPU(struct pt_regs, bpf_pt_regs);
470 static DEFINE_PER_CPU(struct perf_sample_data, bpf_misc_sd);
471
472 u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
473 void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy)
474 {
475 struct perf_sample_data *sd = this_cpu_ptr(&bpf_misc_sd);
476 struct pt_regs *regs = this_cpu_ptr(&bpf_pt_regs);
477 struct perf_raw_frag frag = {
478 .copy = ctx_copy,
479 .size = ctx_size,
480 .data = ctx,
481 };
482 struct perf_raw_record raw = {
483 .frag = {
484 {
485 .next = ctx_size ? &frag : NULL,
486 },
487 .size = meta_size,
488 .data = meta,
489 },
490 };
491
492 perf_fetch_caller_regs(regs);
493 perf_sample_data_init(sd, 0, 0);
494 sd->raw = &raw;
495
496 return __bpf_perf_event_output(regs, map, flags, sd);
497 }
498
499 BPF_CALL_0(bpf_get_current_task)
500 {
501 return (long) current;
502 }
503
504 static const struct bpf_func_proto bpf_get_current_task_proto = {
505 .func = bpf_get_current_task,
506 .gpl_only = true,
507 .ret_type = RET_INTEGER,
508 };
509
510 BPF_CALL_2(bpf_current_task_under_cgroup, struct bpf_map *, map, u32, idx)
511 {
512 struct bpf_array *array = container_of(map, struct bpf_array, map);
513 struct cgroup *cgrp;
514
515 if (unlikely(idx >= array->map.max_entries))
516 return -E2BIG;
517
518 cgrp = READ_ONCE(array->ptrs[idx]);
519 if (unlikely(!cgrp))
520 return -EAGAIN;
521
522 return task_under_cgroup_hierarchy(current, cgrp);
523 }
524
525 static const struct bpf_func_proto bpf_current_task_under_cgroup_proto = {
526 .func = bpf_current_task_under_cgroup,
527 .gpl_only = false,
528 .ret_type = RET_INTEGER,
529 .arg1_type = ARG_CONST_MAP_PTR,
530 .arg2_type = ARG_ANYTHING,
531 };
532
533 BPF_CALL_3(bpf_probe_read_str, void *, dst, u32, size,
534 const void *, unsafe_ptr)
535 {
536 int ret;
537
538 /*
539 * The strncpy_from_unsafe() call will likely not fill the entire
540 * buffer, but that's okay in this circumstance as we're probing
541 * arbitrary memory anyway similar to bpf_probe_read() and might
542 * as well probe the stack. Thus, memory is explicitly cleared
543 * only in error case, so that improper users ignoring return
544 * code altogether don't copy garbage; otherwise length of string
545 * is returned that can be used for bpf_perf_event_output() et al.
546 */
547 ret = strncpy_from_unsafe(dst, unsafe_ptr, size);
548 if (unlikely(ret < 0))
549 memset(dst, 0, size);
550
551 return ret;
552 }
553
554 static const struct bpf_func_proto bpf_probe_read_str_proto = {
555 .func = bpf_probe_read_str,
556 .gpl_only = true,
557 .ret_type = RET_INTEGER,
558 .arg1_type = ARG_PTR_TO_UNINIT_MEM,
559 .arg2_type = ARG_CONST_SIZE_OR_ZERO,
560 .arg3_type = ARG_ANYTHING,
561 };
562
563 static const struct bpf_func_proto *
564 tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
565 {
566 switch (func_id) {
567 case BPF_FUNC_map_lookup_elem:
568 return &bpf_map_lookup_elem_proto;
569 case BPF_FUNC_map_update_elem:
570 return &bpf_map_update_elem_proto;
571 case BPF_FUNC_map_delete_elem:
572 return &bpf_map_delete_elem_proto;
573 case BPF_FUNC_probe_read:
574 return &bpf_probe_read_proto;
575 case BPF_FUNC_ktime_get_ns:
576 return &bpf_ktime_get_ns_proto;
577 case BPF_FUNC_tail_call:
578 return &bpf_tail_call_proto;
579 case BPF_FUNC_get_current_pid_tgid:
580 return &bpf_get_current_pid_tgid_proto;
581 case BPF_FUNC_get_current_task:
582 return &bpf_get_current_task_proto;
583 case BPF_FUNC_get_current_uid_gid:
584 return &bpf_get_current_uid_gid_proto;
585 case BPF_FUNC_get_current_comm:
586 return &bpf_get_current_comm_proto;
587 case BPF_FUNC_trace_printk:
588 return bpf_get_trace_printk_proto();
589 case BPF_FUNC_get_smp_processor_id:
590 return &bpf_get_smp_processor_id_proto;
591 case BPF_FUNC_get_numa_node_id:
592 return &bpf_get_numa_node_id_proto;
593 case BPF_FUNC_perf_event_read:
594 return &bpf_perf_event_read_proto;
595 case BPF_FUNC_probe_write_user:
596 return bpf_get_probe_write_proto();
597 case BPF_FUNC_current_task_under_cgroup:
598 return &bpf_current_task_under_cgroup_proto;
599 case BPF_FUNC_get_prandom_u32:
600 return &bpf_get_prandom_u32_proto;
601 case BPF_FUNC_probe_read_str:
602 return &bpf_probe_read_str_proto;
603 #ifdef CONFIG_CGROUPS
604 case BPF_FUNC_get_current_cgroup_id:
605 return &bpf_get_current_cgroup_id_proto;
606 #endif
607 default:
608 return NULL;
609 }
610 }
611
612 static const struct bpf_func_proto *
613 kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
614 {
615 switch (func_id) {
616 case BPF_FUNC_perf_event_output:
617 return &bpf_perf_event_output_proto;
618 case BPF_FUNC_get_stackid:
619 return &bpf_get_stackid_proto;
620 case BPF_FUNC_get_stack:
621 return &bpf_get_stack_proto;
622 case BPF_FUNC_perf_event_read_value:
623 return &bpf_perf_event_read_value_proto;
624 #ifdef CONFIG_BPF_KPROBE_OVERRIDE
625 case BPF_FUNC_override_return:
626 return &bpf_override_return_proto;
627 #endif
628 default:
629 return tracing_func_proto(func_id, prog);
630 }
631 }
632
633 /* bpf+kprobe programs can access fields of 'struct pt_regs' */
634 static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
635 const struct bpf_prog *prog,
636 struct bpf_insn_access_aux *info)
637 {
638 if (off < 0 || off >= sizeof(struct pt_regs))
639 return false;
640 if (type != BPF_READ)
641 return false;
642 if (off % size != 0)
643 return false;
644 /*
645 * Assertion for 32 bit to make sure last 8 byte access
646 * (BPF_DW) to the last 4 byte member is disallowed.
647 */
648 if (off + size > sizeof(struct pt_regs))
649 return false;
650
651 return true;
652 }
653
654 const struct bpf_verifier_ops kprobe_verifier_ops = {
655 .get_func_proto = kprobe_prog_func_proto,
656 .is_valid_access = kprobe_prog_is_valid_access,
657 };
658
659 const struct bpf_prog_ops kprobe_prog_ops = {
660 };
661
662 BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map,
663 u64, flags, void *, data, u64, size)
664 {
665 struct pt_regs *regs = *(struct pt_regs **)tp_buff;
666
667 /*
668 * r1 points to perf tracepoint buffer where first 8 bytes are hidden
669 * from bpf program and contain a pointer to 'struct pt_regs'. Fetch it
670 * from there and call the same bpf_perf_event_output() helper inline.
671 */
672 return ____bpf_perf_event_output(regs, map, flags, data, size);
673 }
674
675 static const struct bpf_func_proto bpf_perf_event_output_proto_tp = {
676 .func = bpf_perf_event_output_tp,
677 .gpl_only = true,
678 .ret_type = RET_INTEGER,
679 .arg1_type = ARG_PTR_TO_CTX,
680 .arg2_type = ARG_CONST_MAP_PTR,
681 .arg3_type = ARG_ANYTHING,
682 .arg4_type = ARG_PTR_TO_MEM,
683 .arg5_type = ARG_CONST_SIZE_OR_ZERO,
684 };
685
686 BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map,
687 u64, flags)
688 {
689 struct pt_regs *regs = *(struct pt_regs **)tp_buff;
690
691 /*
692 * Same comment as in bpf_perf_event_output_tp(), only that this time
693 * the other helper's function body cannot be inlined due to being
694 * external, thus we need to call raw helper function.
695 */
696 return bpf_get_stackid((unsigned long) regs, (unsigned long) map,
697 flags, 0, 0);
698 }
699
700 static const struct bpf_func_proto bpf_get_stackid_proto_tp = {
701 .func = bpf_get_stackid_tp,
702 .gpl_only = true,
703 .ret_type = RET_INTEGER,
704 .arg1_type = ARG_PTR_TO_CTX,
705 .arg2_type = ARG_CONST_MAP_PTR,
706 .arg3_type = ARG_ANYTHING,
707 };
708
709 BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size,
710 u64, flags)
711 {
712 struct pt_regs *regs = *(struct pt_regs **)tp_buff;
713
714 return bpf_get_stack((unsigned long) regs, (unsigned long) buf,
715 (unsigned long) size, flags, 0);
716 }
717
718 static const struct bpf_func_proto bpf_get_stack_proto_tp = {
719 .func = bpf_get_stack_tp,
720 .gpl_only = true,
721 .ret_type = RET_INTEGER,
722 .arg1_type = ARG_PTR_TO_CTX,
723 .arg2_type = ARG_PTR_TO_UNINIT_MEM,
724 .arg3_type = ARG_CONST_SIZE_OR_ZERO,
725 .arg4_type = ARG_ANYTHING,
726 };
727
728 static const struct bpf_func_proto *
729 tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
730 {
731 switch (func_id) {
732 case BPF_FUNC_perf_event_output:
733 return &bpf_perf_event_output_proto_tp;
734 case BPF_FUNC_get_stackid:
735 return &bpf_get_stackid_proto_tp;
736 case BPF_FUNC_get_stack:
737 return &bpf_get_stack_proto_tp;
738 default:
739 return tracing_func_proto(func_id, prog);
740 }
741 }
742
743 static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type,
744 const struct bpf_prog *prog,
745 struct bpf_insn_access_aux *info)
746 {
747 if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE)
748 return false;
749 if (type != BPF_READ)
750 return false;
751 if (off % size != 0)
752 return false;
753
754 BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(__u64));
755 return true;
756 }
757
758 const struct bpf_verifier_ops tracepoint_verifier_ops = {
759 .get_func_proto = tp_prog_func_proto,
760 .is_valid_access = tp_prog_is_valid_access,
761 };
762
763 const struct bpf_prog_ops tracepoint_prog_ops = {
764 };
765
766 BPF_CALL_3(bpf_perf_prog_read_value, struct bpf_perf_event_data_kern *, ctx,
767 struct bpf_perf_event_value *, buf, u32, size)
768 {
769 int err = -EINVAL;
770
771 if (unlikely(size != sizeof(struct bpf_perf_event_value)))
772 goto clear;
773 err = perf_event_read_local(ctx->event, &buf->counter, &buf->enabled,
774 &buf->running);
775 if (unlikely(err))
776 goto clear;
777 return 0;
778 clear:
779 memset(buf, 0, size);
780 return err;
781 }
782
783 static const struct bpf_func_proto bpf_perf_prog_read_value_proto = {
784 .func = bpf_perf_prog_read_value,
785 .gpl_only = true,
786 .ret_type = RET_INTEGER,
787 .arg1_type = ARG_PTR_TO_CTX,
788 .arg2_type = ARG_PTR_TO_UNINIT_MEM,
789 .arg3_type = ARG_CONST_SIZE,
790 };
791
792 static const struct bpf_func_proto *
793 pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
794 {
795 switch (func_id) {
796 case BPF_FUNC_perf_event_output:
797 return &bpf_perf_event_output_proto_tp;
798 case BPF_FUNC_get_stackid:
799 return &bpf_get_stackid_proto_tp;
800 case BPF_FUNC_get_stack:
801 return &bpf_get_stack_proto_tp;
802 case BPF_FUNC_perf_prog_read_value:
803 return &bpf_perf_prog_read_value_proto;
804 default:
805 return tracing_func_proto(func_id, prog);
806 }
807 }
808
809 /*
810 * bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp
811 * to avoid potential recursive reuse issue when/if tracepoints are added
812 * inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack
813 */
814 static DEFINE_PER_CPU(struct pt_regs, bpf_raw_tp_regs);
815 BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args,
816 struct bpf_map *, map, u64, flags, void *, data, u64, size)
817 {
818 struct pt_regs *regs = this_cpu_ptr(&bpf_raw_tp_regs);
819
820 perf_fetch_caller_regs(regs);
821 return ____bpf_perf_event_output(regs, map, flags, data, size);
822 }
823
824 static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = {
825 .func = bpf_perf_event_output_raw_tp,
826 .gpl_only = true,
827 .ret_type = RET_INTEGER,
828 .arg1_type = ARG_PTR_TO_CTX,
829 .arg2_type = ARG_CONST_MAP_PTR,
830 .arg3_type = ARG_ANYTHING,
831 .arg4_type = ARG_PTR_TO_MEM,
832 .arg5_type = ARG_CONST_SIZE_OR_ZERO,
833 };
834
835 BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args,
836 struct bpf_map *, map, u64, flags)
837 {
838 struct pt_regs *regs = this_cpu_ptr(&bpf_raw_tp_regs);
839
840 perf_fetch_caller_regs(regs);
841 /* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */
842 return bpf_get_stackid((unsigned long) regs, (unsigned long) map,
843 flags, 0, 0);
844 }
845
846 static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = {
847 .func = bpf_get_stackid_raw_tp,
848 .gpl_only = true,
849 .ret_type = RET_INTEGER,
850 .arg1_type = ARG_PTR_TO_CTX,
851 .arg2_type = ARG_CONST_MAP_PTR,
852 .arg3_type = ARG_ANYTHING,
853 };
854
855 BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args,
856 void *, buf, u32, size, u64, flags)
857 {
858 struct pt_regs *regs = this_cpu_ptr(&bpf_raw_tp_regs);
859
860 perf_fetch_caller_regs(regs);
861 return bpf_get_stack((unsigned long) regs, (unsigned long) buf,
862 (unsigned long) size, flags, 0);
863 }
864
865 static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = {
866 .func = bpf_get_stack_raw_tp,
867 .gpl_only = true,
868 .ret_type = RET_INTEGER,
869 .arg1_type = ARG_PTR_TO_CTX,
870 .arg2_type = ARG_PTR_TO_MEM,
871 .arg3_type = ARG_CONST_SIZE_OR_ZERO,
872 .arg4_type = ARG_ANYTHING,
873 };
874
875 static const struct bpf_func_proto *
876 raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
877 {
878 switch (func_id) {
879 case BPF_FUNC_perf_event_output:
880 return &bpf_perf_event_output_proto_raw_tp;
881 case BPF_FUNC_get_stackid:
882 return &bpf_get_stackid_proto_raw_tp;
883 case BPF_FUNC_get_stack:
884 return &bpf_get_stack_proto_raw_tp;
885 default:
886 return tracing_func_proto(func_id, prog);
887 }
888 }
889
890 static bool raw_tp_prog_is_valid_access(int off, int size,
891 enum bpf_access_type type,
892 const struct bpf_prog *prog,
893 struct bpf_insn_access_aux *info)
894 {
895 /* largest tracepoint in the kernel has 12 args */
896 if (off < 0 || off >= sizeof(__u64) * 12)
897 return false;
898 if (type != BPF_READ)
899 return false;
900 if (off % size != 0)
901 return false;
902 return true;
903 }
904
905 const struct bpf_verifier_ops raw_tracepoint_verifier_ops = {
906 .get_func_proto = raw_tp_prog_func_proto,
907 .is_valid_access = raw_tp_prog_is_valid_access,
908 };
909
910 const struct bpf_prog_ops raw_tracepoint_prog_ops = {
911 };
912
913 static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
914 const struct bpf_prog *prog,
915 struct bpf_insn_access_aux *info)
916 {
917 const int size_u64 = sizeof(u64);
918
919 if (off < 0 || off >= sizeof(struct bpf_perf_event_data))
920 return false;
921 if (type != BPF_READ)
922 return false;
923 if (off % size != 0) {
924 if (sizeof(unsigned long) != 4)
925 return false;
926 if (size != 8)
927 return false;
928 if (off % size != 4)
929 return false;
930 }
931
932 switch (off) {
933 case bpf_ctx_range(struct bpf_perf_event_data, sample_period):
934 bpf_ctx_record_field_size(info, size_u64);
935 if (!bpf_ctx_narrow_access_ok(off, size, size_u64))
936 return false;
937 break;
938 case bpf_ctx_range(struct bpf_perf_event_data, addr):
939 bpf_ctx_record_field_size(info, size_u64);
940 if (!bpf_ctx_narrow_access_ok(off, size, size_u64))
941 return false;
942 break;
943 default:
944 if (size != sizeof(long))
945 return false;
946 }
947
948 return true;
949 }
950
951 static u32 pe_prog_convert_ctx_access(enum bpf_access_type type,
952 const struct bpf_insn *si,
953 struct bpf_insn *insn_buf,
954 struct bpf_prog *prog, u32 *target_size)
955 {
956 struct bpf_insn *insn = insn_buf;
957
958 switch (si->off) {
959 case offsetof(struct bpf_perf_event_data, sample_period):
960 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
961 data), si->dst_reg, si->src_reg,
962 offsetof(struct bpf_perf_event_data_kern, data));
963 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg,
964 bpf_target_off(struct perf_sample_data, period, 8,
965 target_size));
966 break;
967 case offsetof(struct bpf_perf_event_data, addr):
968 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
969 data), si->dst_reg, si->src_reg,
970 offsetof(struct bpf_perf_event_data_kern, data));
971 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg,
972 bpf_target_off(struct perf_sample_data, addr, 8,
973 target_size));
974 break;
975 default:
976 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
977 regs), si->dst_reg, si->src_reg,
978 offsetof(struct bpf_perf_event_data_kern, regs));
979 *insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg,
980 si->off);
981 break;
982 }
983
984 return insn - insn_buf;
985 }
986
987 const struct bpf_verifier_ops perf_event_verifier_ops = {
988 .get_func_proto = pe_prog_func_proto,
989 .is_valid_access = pe_prog_is_valid_access,
990 .convert_ctx_access = pe_prog_convert_ctx_access,
991 };
992
993 const struct bpf_prog_ops perf_event_prog_ops = {
994 };
995
996 static DEFINE_MUTEX(bpf_event_mutex);
997
998 #define BPF_TRACE_MAX_PROGS 64
999
1000 int perf_event_attach_bpf_prog(struct perf_event *event,
1001 struct bpf_prog *prog)
1002 {
1003 struct bpf_prog_array __rcu *old_array;
1004 struct bpf_prog_array *new_array;
1005 int ret = -EEXIST;
1006
1007 /*
1008 * Kprobe override only works if they are on the function entry,
1009 * and only if they are on the opt-in list.
1010 */
1011 if (prog->kprobe_override &&
1012 (!trace_kprobe_on_func_entry(event->tp_event) ||
1013 !trace_kprobe_error_injectable(event->tp_event)))
1014 return -EINVAL;
1015
1016 mutex_lock(&bpf_event_mutex);
1017
1018 if (event->prog)
1019 goto unlock;
1020
1021 old_array = event->tp_event->prog_array;
1022 if (old_array &&
1023 bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) {
1024 ret = -E2BIG;
1025 goto unlock;
1026 }
1027
1028 ret = bpf_prog_array_copy(old_array, NULL, prog, &new_array);
1029 if (ret < 0)
1030 goto unlock;
1031
1032 /* set the new array to event->tp_event and set event->prog */
1033 event->prog = prog;
1034 rcu_assign_pointer(event->tp_event->prog_array, new_array);
1035 bpf_prog_array_free(old_array);
1036
1037 unlock:
1038 mutex_unlock(&bpf_event_mutex);
1039 return ret;
1040 }
1041
1042 void perf_event_detach_bpf_prog(struct perf_event *event)
1043 {
1044 struct bpf_prog_array __rcu *old_array;
1045 struct bpf_prog_array *new_array;
1046 int ret;
1047
1048 mutex_lock(&bpf_event_mutex);
1049
1050 if (!event->prog)
1051 goto unlock;
1052
1053 old_array = event->tp_event->prog_array;
1054 ret = bpf_prog_array_copy(old_array, event->prog, NULL, &new_array);
1055 if (ret == -ENOENT)
1056 goto unlock;
1057 if (ret < 0) {
1058 bpf_prog_array_delete_safe(old_array, event->prog);
1059 } else {
1060 rcu_assign_pointer(event->tp_event->prog_array, new_array);
1061 bpf_prog_array_free(old_array);
1062 }
1063
1064 bpf_prog_put(event->prog);
1065 event->prog = NULL;
1066
1067 unlock:
1068 mutex_unlock(&bpf_event_mutex);
1069 }
1070
1071 int perf_event_query_prog_array(struct perf_event *event, void __user *info)
1072 {
1073 struct perf_event_query_bpf __user *uquery = info;
1074 struct perf_event_query_bpf query = {};
1075 u32 *ids, prog_cnt, ids_len;
1076 int ret;
1077
1078 if (!capable(CAP_SYS_ADMIN))
1079 return -EPERM;
1080 if (event->attr.type != PERF_TYPE_TRACEPOINT)
1081 return -EINVAL;
1082 if (copy_from_user(&query, uquery, sizeof(query)))
1083 return -EFAULT;
1084
1085 ids_len = query.ids_len;
1086 if (ids_len > BPF_TRACE_MAX_PROGS)
1087 return -E2BIG;
1088 ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN);
1089 if (!ids)
1090 return -ENOMEM;
1091 /*
1092 * The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which
1093 * is required when user only wants to check for uquery->prog_cnt.
1094 * There is no need to check for it since the case is handled
1095 * gracefully in bpf_prog_array_copy_info.
1096 */
1097
1098 mutex_lock(&bpf_event_mutex);
1099 ret = bpf_prog_array_copy_info(event->tp_event->prog_array,
1100 ids,
1101 ids_len,
1102 &prog_cnt);
1103 mutex_unlock(&bpf_event_mutex);
1104
1105 if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) ||
1106 copy_to_user(uquery->ids, ids, ids_len * sizeof(u32)))
1107 ret = -EFAULT;
1108
1109 kfree(ids);
1110 return ret;
1111 }
1112
1113 extern struct bpf_raw_event_map __start__bpf_raw_tp[];
1114 extern struct bpf_raw_event_map __stop__bpf_raw_tp[];
1115
1116 struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name)
1117 {
1118 struct bpf_raw_event_map *btp = __start__bpf_raw_tp;
1119
1120 for (; btp < __stop__bpf_raw_tp; btp++) {
1121 if (!strcmp(btp->tp->name, name))
1122 return btp;
1123 }
1124
1125 return bpf_get_raw_tracepoint_module(name);
1126 }
1127
1128 void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp)
1129 {
1130 struct module *mod = __module_address((unsigned long)btp);
1131
1132 if (mod)
1133 module_put(mod);
1134 }
1135
1136 static __always_inline
1137 void __bpf_trace_run(struct bpf_prog *prog, u64 *args)
1138 {
1139 rcu_read_lock();
1140 preempt_disable();
1141 (void) BPF_PROG_RUN(prog, args);
1142 preempt_enable();
1143 rcu_read_unlock();
1144 }
1145
1146 #define UNPACK(...) __VA_ARGS__
1147 #define REPEAT_1(FN, DL, X, ...) FN(X)
1148 #define REPEAT_2(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__)
1149 #define REPEAT_3(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_2(FN, DL, __VA_ARGS__)
1150 #define REPEAT_4(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_3(FN, DL, __VA_ARGS__)
1151 #define REPEAT_5(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_4(FN, DL, __VA_ARGS__)
1152 #define REPEAT_6(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_5(FN, DL, __VA_ARGS__)
1153 #define REPEAT_7(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_6(FN, DL, __VA_ARGS__)
1154 #define REPEAT_8(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_7(FN, DL, __VA_ARGS__)
1155 #define REPEAT_9(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_8(FN, DL, __VA_ARGS__)
1156 #define REPEAT_10(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_9(FN, DL, __VA_ARGS__)
1157 #define REPEAT_11(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_10(FN, DL, __VA_ARGS__)
1158 #define REPEAT_12(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_11(FN, DL, __VA_ARGS__)
1159 #define REPEAT(X, FN, DL, ...) REPEAT_##X(FN, DL, __VA_ARGS__)
1160
1161 #define SARG(X) u64 arg##X
1162 #define COPY(X) args[X] = arg##X
1163
1164 #define __DL_COM (,)
1165 #define __DL_SEM (;)
1166
1167 #define __SEQ_0_11 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11
1168
1169 #define BPF_TRACE_DEFN_x(x) \
1170 void bpf_trace_run##x(struct bpf_prog *prog, \
1171 REPEAT(x, SARG, __DL_COM, __SEQ_0_11)) \
1172 { \
1173 u64 args[x]; \
1174 REPEAT(x, COPY, __DL_SEM, __SEQ_0_11); \
1175 __bpf_trace_run(prog, args); \
1176 } \
1177 EXPORT_SYMBOL_GPL(bpf_trace_run##x)
1178 BPF_TRACE_DEFN_x(1);
1179 BPF_TRACE_DEFN_x(2);
1180 BPF_TRACE_DEFN_x(3);
1181 BPF_TRACE_DEFN_x(4);
1182 BPF_TRACE_DEFN_x(5);
1183 BPF_TRACE_DEFN_x(6);
1184 BPF_TRACE_DEFN_x(7);
1185 BPF_TRACE_DEFN_x(8);
1186 BPF_TRACE_DEFN_x(9);
1187 BPF_TRACE_DEFN_x(10);
1188 BPF_TRACE_DEFN_x(11);
1189 BPF_TRACE_DEFN_x(12);
1190
1191 static int __bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog)
1192 {
1193 struct tracepoint *tp = btp->tp;
1194
1195 /*
1196 * check that program doesn't access arguments beyond what's
1197 * available in this tracepoint
1198 */
1199 if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64))
1200 return -EINVAL;
1201
1202 return tracepoint_probe_register(tp, (void *)btp->bpf_func, prog);
1203 }
1204
1205 int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog)
1206 {
1207 int err;
1208
1209 mutex_lock(&bpf_event_mutex);
1210 err = __bpf_probe_register(btp, prog);
1211 mutex_unlock(&bpf_event_mutex);
1212 return err;
1213 }
1214
1215 int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_prog *prog)
1216 {
1217 int err;
1218
1219 mutex_lock(&bpf_event_mutex);
1220 err = tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, prog);
1221 mutex_unlock(&bpf_event_mutex);
1222 return err;
1223 }
1224
1225 int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id,
1226 u32 *fd_type, const char **buf,
1227 u64 *probe_offset, u64 *probe_addr)
1228 {
1229 bool is_tracepoint, is_syscall_tp;
1230 struct bpf_prog *prog;
1231 int flags, err = 0;
1232
1233 prog = event->prog;
1234 if (!prog)
1235 return -ENOENT;
1236
1237 /* not supporting BPF_PROG_TYPE_PERF_EVENT yet */
1238 if (prog->type == BPF_PROG_TYPE_PERF_EVENT)
1239 return -EOPNOTSUPP;
1240
1241 *prog_id = prog->aux->id;
1242 flags = event->tp_event->flags;
1243 is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT;
1244 is_syscall_tp = is_syscall_trace_event(event->tp_event);
1245
1246 if (is_tracepoint || is_syscall_tp) {
1247 *buf = is_tracepoint ? event->tp_event->tp->name
1248 : event->tp_event->name;
1249 *fd_type = BPF_FD_TYPE_TRACEPOINT;
1250 *probe_offset = 0x0;
1251 *probe_addr = 0x0;
1252 } else {
1253 /* kprobe/uprobe */
1254 err = -EOPNOTSUPP;
1255 #ifdef CONFIG_KPROBE_EVENTS
1256 if (flags & TRACE_EVENT_FL_KPROBE)
1257 err = bpf_get_kprobe_info(event, fd_type, buf,
1258 probe_offset, probe_addr,
1259 event->attr.type == PERF_TYPE_TRACEPOINT);
1260 #endif
1261 #ifdef CONFIG_UPROBE_EVENTS
1262 if (flags & TRACE_EVENT_FL_UPROBE)
1263 err = bpf_get_uprobe_info(event, fd_type, buf,
1264 probe_offset,
1265 event->attr.type == PERF_TYPE_TRACEPOINT);
1266 #endif
1267 }
1268
1269 return err;
1270 }
1271
1272 #ifdef CONFIG_MODULES
1273 int bpf_event_notify(struct notifier_block *nb, unsigned long op, void *module)
1274 {
1275 struct bpf_trace_module *btm, *tmp;
1276 struct module *mod = module;
1277
1278 if (mod->num_bpf_raw_events == 0 ||
1279 (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING))
1280 return 0;
1281
1282 mutex_lock(&bpf_module_mutex);
1283
1284 switch (op) {
1285 case MODULE_STATE_COMING:
1286 btm = kzalloc(sizeof(*btm), GFP_KERNEL);
1287 if (btm) {
1288 btm->module = module;
1289 list_add(&btm->list, &bpf_trace_modules);
1290 }
1291 break;
1292 case MODULE_STATE_GOING:
1293 list_for_each_entry_safe(btm, tmp, &bpf_trace_modules, list) {
1294 if (btm->module == module) {
1295 list_del(&btm->list);
1296 kfree(btm);
1297 break;
1298 }
1299 }
1300 break;
1301 }
1302
1303 mutex_unlock(&bpf_module_mutex);
1304
1305 return 0;
1306 }
1307
1308 static struct notifier_block bpf_module_nb = {
1309 .notifier_call = bpf_event_notify,
1310 };
1311
1312 int __init bpf_event_init(void)
1313 {
1314 register_module_notifier(&bpf_module_nb);
1315 return 0;
1316 }
1317
1318 fs_initcall(bpf_event_init);
1319 #endif /* CONFIG_MODULES */
Linux with added FPC-III support