1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2011-2015 PLUMgrid, http://plumgrid.com
3 * Copyright (c) 2016 Facebook
4 */
5 #include <linux/kernel.h>
6 #include <linux/types.h>
7 #include <linux/slab.h>
8 #include <linux/bpf.h>
9 #include <linux/bpf_verifier.h>
10 #include <linux/bpf_perf_event.h>
11 #include <linux/btf.h>
12 #include <linux/filter.h>
13 #include <linux/uaccess.h>
14 #include <linux/ctype.h>
15 #include <linux/kprobes.h>
16 #include <linux/spinlock.h>
17 #include <linux/syscalls.h>
18 #include <linux/error-injection.h>
19 #include <linux/btf_ids.h>
20 #include <linux/bpf_lsm.h>
21 #include <linux/fprobe.h>
22 #include <linux/bsearch.h>
23 #include <linux/sort.h>
24 #include <linux/key.h>
25 #include <linux/verification.h>
26 #include <linux/namei.h>
27
28 #include <net/bpf_sk_storage.h>
29
30 #include <uapi/linux/bpf.h>
31 #include <uapi/linux/btf.h>
32
33 #include <asm/tlb.h>
34
35 #include "trace_probe.h"
36 #include "trace.h"
37
38 #define CREATE_TRACE_POINTS
39 #include "bpf_trace.h"
40
41 #define bpf_event_rcu_dereference(p) \
42 rcu_dereference_protected(p, lockdep_is_held(&bpf_event_mutex))
43
44 #define MAX_UPROBE_MULTI_CNT (1U << 20)
45 #define MAX_KPROBE_MULTI_CNT (1U << 20)
46
47 #ifdef CONFIG_MODULES
48 struct bpf_trace_module {
49 struct module *module;
50 struct list_head list;
51 };
52
53 static LIST_HEAD(bpf_trace_modules);
54 static DEFINE_MUTEX(bpf_module_mutex);
55
bpf_get_raw_tracepoint_module(const char * name)56 static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name)
57 {
58 struct bpf_raw_event_map *btp, *ret = NULL;
59 struct bpf_trace_module *btm;
60 unsigned int i;
61
62 mutex_lock(&bpf_module_mutex);
63 list_for_each_entry(btm, &bpf_trace_modules, list) {
64 for (i = 0; i < btm->module->num_bpf_raw_events; ++i) {
65 btp = &btm->module->bpf_raw_events[i];
66 if (!strcmp(btp->tp->name, name)) {
67 if (try_module_get(btm->module))
68 ret = btp;
69 goto out;
70 }
71 }
72 }
73 out:
74 mutex_unlock(&bpf_module_mutex);
75 return ret;
76 }
77 #else
bpf_get_raw_tracepoint_module(const char * name)78 static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name)
79 {
80 return NULL;
81 }
82 #endif /* CONFIG_MODULES */
83
84 u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
85 u64 bpf_get_stack(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
86
87 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size,
88 u64 flags, const struct btf **btf,
89 s32 *btf_id);
90 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx);
91 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx);
92
93 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx);
94 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx);
95
96 /**
97 * trace_call_bpf - invoke BPF program
98 * @call: tracepoint event
99 * @ctx: opaque context pointer
100 *
101 * kprobe handlers execute BPF programs via this helper.
102 * Can be used from static tracepoints in the future.
103 *
104 * Return: BPF programs always return an integer which is interpreted by
105 * kprobe handler as:
106 * 0 - return from kprobe (event is filtered out)
107 * 1 - store kprobe event into ring buffer
108 * Other values are reserved and currently alias to 1
109 */
trace_call_bpf(struct trace_event_call * call,void * ctx)110 unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx)
111 {
112 unsigned int ret;
113
114 cant_sleep();
115
116 if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) {
117 /*
118 * since some bpf program is already running on this cpu,
119 * don't call into another bpf program (same or different)
120 * and don't send kprobe event into ring-buffer,
121 * so return zero here
122 */
123 rcu_read_lock();
124 bpf_prog_inc_misses_counters(rcu_dereference(call->prog_array));
125 rcu_read_unlock();
126 ret = 0;
127 goto out;
128 }
129
130 /*
131 * Instead of moving rcu_read_lock/rcu_dereference/rcu_read_unlock
132 * to all call sites, we did a bpf_prog_array_valid() there to check
133 * whether call->prog_array is empty or not, which is
134 * a heuristic to speed up execution.
135 *
136 * If bpf_prog_array_valid() fetched prog_array was
137 * non-NULL, we go into trace_call_bpf() and do the actual
138 * proper rcu_dereference() under RCU lock.
139 * If it turns out that prog_array is NULL then, we bail out.
140 * For the opposite, if the bpf_prog_array_valid() fetched pointer
141 * was NULL, you'll skip the prog_array with the risk of missing
142 * out of events when it was updated in between this and the
143 * rcu_dereference() which is accepted risk.
144 */
145 rcu_read_lock();
146 ret = bpf_prog_run_array(rcu_dereference(call->prog_array),
147 ctx, bpf_prog_run);
148 rcu_read_unlock();
149
150 out:
151 __this_cpu_dec(bpf_prog_active);
152
153 return ret;
154 }
155
156 #ifdef CONFIG_BPF_KPROBE_OVERRIDE
BPF_CALL_2(bpf_override_return,struct pt_regs *,regs,unsigned long,rc)157 BPF_CALL_2(bpf_override_return, struct pt_regs *, regs, unsigned long, rc)
158 {
159 regs_set_return_value(regs, rc);
160 override_function_with_return(regs);
161 return 0;
162 }
163
164 static const struct bpf_func_proto bpf_override_return_proto = {
165 .func = bpf_override_return,
166 .gpl_only = true,
167 .ret_type = RET_INTEGER,
168 .arg1_type = ARG_PTR_TO_CTX,
169 .arg2_type = ARG_ANYTHING,
170 };
171 #endif
172
173 static __always_inline int
bpf_probe_read_user_common(void * dst,u32 size,const void __user * unsafe_ptr)174 bpf_probe_read_user_common(void *dst, u32 size, const void __user *unsafe_ptr)
175 {
176 int ret;
177
178 ret = copy_from_user_nofault(dst, unsafe_ptr, size);
179 if (unlikely(ret < 0))
180 memset(dst, 0, size);
181 return ret;
182 }
183
BPF_CALL_3(bpf_probe_read_user,void *,dst,u32,size,const void __user *,unsafe_ptr)184 BPF_CALL_3(bpf_probe_read_user, void *, dst, u32, size,
185 const void __user *, unsafe_ptr)
186 {
187 return bpf_probe_read_user_common(dst, size, unsafe_ptr);
188 }
189
190 const struct bpf_func_proto bpf_probe_read_user_proto = {
191 .func = bpf_probe_read_user,
192 .gpl_only = true,
193 .ret_type = RET_INTEGER,
194 .arg1_type = ARG_PTR_TO_UNINIT_MEM,
195 .arg2_type = ARG_CONST_SIZE_OR_ZERO,
196 .arg3_type = ARG_ANYTHING,
197 };
198
199 static __always_inline int
bpf_probe_read_user_str_common(void * dst,u32 size,const void __user * unsafe_ptr)200 bpf_probe_read_user_str_common(void *dst, u32 size,
201 const void __user *unsafe_ptr)
202 {
203 int ret;
204
205 /*
206 * NB: We rely on strncpy_from_user() not copying junk past the NUL
207 * terminator into `dst`.
208 *
209 * strncpy_from_user() does long-sized strides in the fast path. If the
210 * strncpy does not mask out the bytes after the NUL in `unsafe_ptr`,
211 * then there could be junk after the NUL in `dst`. If user takes `dst`
212 * and keys a hash map with it, then semantically identical strings can
213 * occupy multiple entries in the map.
214 */
215 ret = strncpy_from_user_nofault(dst, unsafe_ptr, size);
216 if (unlikely(ret < 0))
217 memset(dst, 0, size);
218 return ret;
219 }
220
BPF_CALL_3(bpf_probe_read_user_str,void *,dst,u32,size,const void __user *,unsafe_ptr)221 BPF_CALL_3(bpf_probe_read_user_str, void *, dst, u32, size,
222 const void __user *, unsafe_ptr)
223 {
224 return bpf_probe_read_user_str_common(dst, size, unsafe_ptr);
225 }
226
227 const struct bpf_func_proto bpf_probe_read_user_str_proto = {
228 .func = bpf_probe_read_user_str,
229 .gpl_only = true,
230 .ret_type = RET_INTEGER,
231 .arg1_type = ARG_PTR_TO_UNINIT_MEM,
232 .arg2_type = ARG_CONST_SIZE_OR_ZERO,
233 .arg3_type = ARG_ANYTHING,
234 };
235
BPF_CALL_3(bpf_probe_read_kernel,void *,dst,u32,size,const void *,unsafe_ptr)236 BPF_CALL_3(bpf_probe_read_kernel, void *, dst, u32, size,
237 const void *, unsafe_ptr)
238 {
239 return bpf_probe_read_kernel_common(dst, size, unsafe_ptr);
240 }
241
242 const struct bpf_func_proto bpf_probe_read_kernel_proto = {
243 .func = bpf_probe_read_kernel,
244 .gpl_only = true,
245 .ret_type = RET_INTEGER,
246 .arg1_type = ARG_PTR_TO_UNINIT_MEM,
247 .arg2_type = ARG_CONST_SIZE_OR_ZERO,
248 .arg3_type = ARG_ANYTHING,
249 };
250
251 static __always_inline int
bpf_probe_read_kernel_str_common(void * dst,u32 size,const void * unsafe_ptr)252 bpf_probe_read_kernel_str_common(void *dst, u32 size, const void *unsafe_ptr)
253 {
254 int ret;
255
256 /*
257 * The strncpy_from_kernel_nofault() call will likely not fill the
258 * entire buffer, but that's okay in this circumstance as we're probing
259 * arbitrary memory anyway similar to bpf_probe_read_*() and might
260 * as well probe the stack. Thus, memory is explicitly cleared
261 * only in error case, so that improper users ignoring return
262 * code altogether don't copy garbage; otherwise length of string
263 * is returned that can be used for bpf_perf_event_output() et al.
264 */
265 ret = strncpy_from_kernel_nofault(dst, unsafe_ptr, size);
266 if (unlikely(ret < 0))
267 memset(dst, 0, size);
268 return ret;
269 }
270
BPF_CALL_3(bpf_probe_read_kernel_str,void *,dst,u32,size,const void *,unsafe_ptr)271 BPF_CALL_3(bpf_probe_read_kernel_str, void *, dst, u32, size,
272 const void *, unsafe_ptr)
273 {
274 return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr);
275 }
276
277 const struct bpf_func_proto bpf_probe_read_kernel_str_proto = {
278 .func = bpf_probe_read_kernel_str,
279 .gpl_only = true,
280 .ret_type = RET_INTEGER,
281 .arg1_type = ARG_PTR_TO_UNINIT_MEM,
282 .arg2_type = ARG_CONST_SIZE_OR_ZERO,
283 .arg3_type = ARG_ANYTHING,
284 };
285
286 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
BPF_CALL_3(bpf_probe_read_compat,void *,dst,u32,size,const void *,unsafe_ptr)287 BPF_CALL_3(bpf_probe_read_compat, void *, dst, u32, size,
288 const void *, unsafe_ptr)
289 {
290 if ((unsigned long)unsafe_ptr < TASK_SIZE) {
291 return bpf_probe_read_user_common(dst, size,
292 (__force void __user *)unsafe_ptr);
293 }
294 return bpf_probe_read_kernel_common(dst, size, unsafe_ptr);
295 }
296
297 static const struct bpf_func_proto bpf_probe_read_compat_proto = {
298 .func = bpf_probe_read_compat,
299 .gpl_only = true,
300 .ret_type = RET_INTEGER,
301 .arg1_type = ARG_PTR_TO_UNINIT_MEM,
302 .arg2_type = ARG_CONST_SIZE_OR_ZERO,
303 .arg3_type = ARG_ANYTHING,
304 };
305
BPF_CALL_3(bpf_probe_read_compat_str,void *,dst,u32,size,const void *,unsafe_ptr)306 BPF_CALL_3(bpf_probe_read_compat_str, void *, dst, u32, size,
307 const void *, unsafe_ptr)
308 {
309 if ((unsigned long)unsafe_ptr < TASK_SIZE) {
310 return bpf_probe_read_user_str_common(dst, size,
311 (__force void __user *)unsafe_ptr);
312 }
313 return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr);
314 }
315
316 static const struct bpf_func_proto bpf_probe_read_compat_str_proto = {
317 .func = bpf_probe_read_compat_str,
318 .gpl_only = true,
319 .ret_type = RET_INTEGER,
320 .arg1_type = ARG_PTR_TO_UNINIT_MEM,
321 .arg2_type = ARG_CONST_SIZE_OR_ZERO,
322 .arg3_type = ARG_ANYTHING,
323 };
324 #endif /* CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE */
325
BPF_CALL_3(bpf_probe_write_user,void __user *,unsafe_ptr,const void *,src,u32,size)326 BPF_CALL_3(bpf_probe_write_user, void __user *, unsafe_ptr, const void *, src,
327 u32, size)
328 {
329 /*
330 * Ensure we're in user context which is safe for the helper to
331 * run. This helper has no business in a kthread.
332 *
333 * access_ok() should prevent writing to non-user memory, but in
334 * some situations (nommu, temporary switch, etc) access_ok() does
335 * not provide enough validation, hence the check on KERNEL_DS.
336 *
337 * nmi_uaccess_okay() ensures the probe is not run in an interim
338 * state, when the task or mm are switched. This is specifically
339 * required to prevent the use of temporary mm.
340 */
341
342 if (unlikely(in_interrupt() ||
343 current->flags & (PF_KTHREAD | PF_EXITING)))
344 return -EPERM;
345 if (unlikely(!nmi_uaccess_okay()))
346 return -EPERM;
347
348 return copy_to_user_nofault(unsafe_ptr, src, size);
349 }
350
351 static const struct bpf_func_proto bpf_probe_write_user_proto = {
352 .func = bpf_probe_write_user,
353 .gpl_only = true,
354 .ret_type = RET_INTEGER,
355 .arg1_type = ARG_ANYTHING,
356 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
357 .arg3_type = ARG_CONST_SIZE,
358 };
359
360 #define MAX_TRACE_PRINTK_VARARGS 3
361 #define BPF_TRACE_PRINTK_SIZE 1024
362
BPF_CALL_5(bpf_trace_printk,char *,fmt,u32,fmt_size,u64,arg1,u64,arg2,u64,arg3)363 BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1,
364 u64, arg2, u64, arg3)
365 {
366 u64 args[MAX_TRACE_PRINTK_VARARGS] = { arg1, arg2, arg3 };
367 struct bpf_bprintf_data data = {
368 .get_bin_args = true,
369 .get_buf = true,
370 };
371 int ret;
372
373 ret = bpf_bprintf_prepare(fmt, fmt_size, args,
374 MAX_TRACE_PRINTK_VARARGS, &data);
375 if (ret < 0)
376 return ret;
377
378 ret = bstr_printf(data.buf, MAX_BPRINTF_BUF, fmt, data.bin_args);
379
380 trace_bpf_trace_printk(data.buf);
381
382 bpf_bprintf_cleanup(&data);
383
384 return ret;
385 }
386
387 static const struct bpf_func_proto bpf_trace_printk_proto = {
388 .func = bpf_trace_printk,
389 .gpl_only = true,
390 .ret_type = RET_INTEGER,
391 .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY,
392 .arg2_type = ARG_CONST_SIZE,
393 };
394
__set_printk_clr_event(struct work_struct * work)395 static void __set_printk_clr_event(struct work_struct *work)
396 {
397 /*
398 * This program might be calling bpf_trace_printk,
399 * so enable the associated bpf_trace/bpf_trace_printk event.
400 * Repeat this each time as it is possible a user has
401 * disabled bpf_trace_printk events. By loading a program
402 * calling bpf_trace_printk() however the user has expressed
403 * the intent to see such events.
404 */
405 if (trace_set_clr_event("bpf_trace", "bpf_trace_printk", 1))
406 pr_warn_ratelimited("could not enable bpf_trace_printk events");
407 }
408 static DECLARE_WORK(set_printk_work, __set_printk_clr_event);
409
bpf_get_trace_printk_proto(void)410 const struct bpf_func_proto *bpf_get_trace_printk_proto(void)
411 {
412 schedule_work(&set_printk_work);
413 return &bpf_trace_printk_proto;
414 }
415
BPF_CALL_4(bpf_trace_vprintk,char *,fmt,u32,fmt_size,const void *,args,u32,data_len)416 BPF_CALL_4(bpf_trace_vprintk, char *, fmt, u32, fmt_size, const void *, args,
417 u32, data_len)
418 {
419 struct bpf_bprintf_data data = {
420 .get_bin_args = true,
421 .get_buf = true,
422 };
423 int ret, num_args;
424
425 if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 ||
426 (data_len && !args))
427 return -EINVAL;
428 num_args = data_len / 8;
429
430 ret = bpf_bprintf_prepare(fmt, fmt_size, args, num_args, &data);
431 if (ret < 0)
432 return ret;
433
434 ret = bstr_printf(data.buf, MAX_BPRINTF_BUF, fmt, data.bin_args);
435
436 trace_bpf_trace_printk(data.buf);
437
438 bpf_bprintf_cleanup(&data);
439
440 return ret;
441 }
442
443 static const struct bpf_func_proto bpf_trace_vprintk_proto = {
444 .func = bpf_trace_vprintk,
445 .gpl_only = true,
446 .ret_type = RET_INTEGER,
447 .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY,
448 .arg2_type = ARG_CONST_SIZE,
449 .arg3_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY,
450 .arg4_type = ARG_CONST_SIZE_OR_ZERO,
451 };
452
bpf_get_trace_vprintk_proto(void)453 const struct bpf_func_proto *bpf_get_trace_vprintk_proto(void)
454 {
455 schedule_work(&set_printk_work);
456 return &bpf_trace_vprintk_proto;
457 }
458
BPF_CALL_5(bpf_seq_printf,struct seq_file *,m,char *,fmt,u32,fmt_size,const void *,args,u32,data_len)459 BPF_CALL_5(bpf_seq_printf, struct seq_file *, m, char *, fmt, u32, fmt_size,
460 const void *, args, u32, data_len)
461 {
462 struct bpf_bprintf_data data = {
463 .get_bin_args = true,
464 };
465 int err, num_args;
466
467 if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 ||
468 (data_len && !args))
469 return -EINVAL;
470 num_args = data_len / 8;
471
472 err = bpf_bprintf_prepare(fmt, fmt_size, args, num_args, &data);
473 if (err < 0)
474 return err;
475
476 seq_bprintf(m, fmt, data.bin_args);
477
478 bpf_bprintf_cleanup(&data);
479
480 return seq_has_overflowed(m) ? -EOVERFLOW : 0;
481 }
482
483 BTF_ID_LIST_SINGLE(btf_seq_file_ids, struct, seq_file)
484
485 static const struct bpf_func_proto bpf_seq_printf_proto = {
486 .func = bpf_seq_printf,
487 .gpl_only = true,
488 .ret_type = RET_INTEGER,
489 .arg1_type = ARG_PTR_TO_BTF_ID,
490 .arg1_btf_id = &btf_seq_file_ids[0],
491 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
492 .arg3_type = ARG_CONST_SIZE,
493 .arg4_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY,
494 .arg5_type = ARG_CONST_SIZE_OR_ZERO,
495 };
496
BPF_CALL_3(bpf_seq_write,struct seq_file *,m,const void *,data,u32,len)497 BPF_CALL_3(bpf_seq_write, struct seq_file *, m, const void *, data, u32, len)
498 {
499 return seq_write(m, data, len) ? -EOVERFLOW : 0;
500 }
501
502 static const struct bpf_func_proto bpf_seq_write_proto = {
503 .func = bpf_seq_write,
504 .gpl_only = true,
505 .ret_type = RET_INTEGER,
506 .arg1_type = ARG_PTR_TO_BTF_ID,
507 .arg1_btf_id = &btf_seq_file_ids[0],
508 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
509 .arg3_type = ARG_CONST_SIZE_OR_ZERO,
510 };
511
BPF_CALL_4(bpf_seq_printf_btf,struct seq_file *,m,struct btf_ptr *,ptr,u32,btf_ptr_size,u64,flags)512 BPF_CALL_4(bpf_seq_printf_btf, struct seq_file *, m, struct btf_ptr *, ptr,
513 u32, btf_ptr_size, u64, flags)
514 {
515 const struct btf *btf;
516 s32 btf_id;
517 int ret;
518
519 ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id);
520 if (ret)
521 return ret;
522
523 return btf_type_seq_show_flags(btf, btf_id, ptr->ptr, m, flags);
524 }
525
526 static const struct bpf_func_proto bpf_seq_printf_btf_proto = {
527 .func = bpf_seq_printf_btf,
528 .gpl_only = true,
529 .ret_type = RET_INTEGER,
530 .arg1_type = ARG_PTR_TO_BTF_ID,
531 .arg1_btf_id = &btf_seq_file_ids[0],
532 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
533 .arg3_type = ARG_CONST_SIZE_OR_ZERO,
534 .arg4_type = ARG_ANYTHING,
535 };
536
537 static __always_inline int
get_map_perf_counter(struct bpf_map * map,u64 flags,u64 * value,u64 * enabled,u64 * running)538 get_map_perf_counter(struct bpf_map *map, u64 flags,
539 u64 *value, u64 *enabled, u64 *running)
540 {
541 struct bpf_array *array = container_of(map, struct bpf_array, map);
542 unsigned int cpu = smp_processor_id();
543 u64 index = flags & BPF_F_INDEX_MASK;
544 struct bpf_event_entry *ee;
545
546 if (unlikely(flags & ~(BPF_F_INDEX_MASK)))
547 return -EINVAL;
548 if (index == BPF_F_CURRENT_CPU)
549 index = cpu;
550 if (unlikely(index >= array->map.max_entries))
551 return -E2BIG;
552
553 ee = READ_ONCE(array->ptrs[index]);
554 if (!ee)
555 return -ENOENT;
556
557 return perf_event_read_local(ee->event, value, enabled, running);
558 }
559
BPF_CALL_2(bpf_perf_event_read,struct bpf_map *,map,u64,flags)560 BPF_CALL_2(bpf_perf_event_read, struct bpf_map *, map, u64, flags)
561 {
562 u64 value = 0;
563 int err;
564
565 err = get_map_perf_counter(map, flags, &value, NULL, NULL);
566 /*
567 * this api is ugly since we miss [-22..-2] range of valid
568 * counter values, but that's uapi
569 */
570 if (err)
571 return err;
572 return value;
573 }
574
575 static const struct bpf_func_proto bpf_perf_event_read_proto = {
576 .func = bpf_perf_event_read,
577 .gpl_only = true,
578 .ret_type = RET_INTEGER,
579 .arg1_type = ARG_CONST_MAP_PTR,
580 .arg2_type = ARG_ANYTHING,
581 };
582
BPF_CALL_4(bpf_perf_event_read_value,struct bpf_map *,map,u64,flags,struct bpf_perf_event_value *,buf,u32,size)583 BPF_CALL_4(bpf_perf_event_read_value, struct bpf_map *, map, u64, flags,
584 struct bpf_perf_event_value *, buf, u32, size)
585 {
586 int err = -EINVAL;
587
588 if (unlikely(size != sizeof(struct bpf_perf_event_value)))
589 goto clear;
590 err = get_map_perf_counter(map, flags, &buf->counter, &buf->enabled,
591 &buf->running);
592 if (unlikely(err))
593 goto clear;
594 return 0;
595 clear:
596 memset(buf, 0, size);
597 return err;
598 }
599
600 static const struct bpf_func_proto bpf_perf_event_read_value_proto = {
601 .func = bpf_perf_event_read_value,
602 .gpl_only = true,
603 .ret_type = RET_INTEGER,
604 .arg1_type = ARG_CONST_MAP_PTR,
605 .arg2_type = ARG_ANYTHING,
606 .arg3_type = ARG_PTR_TO_UNINIT_MEM,
607 .arg4_type = ARG_CONST_SIZE,
608 };
609
bpf_get_perf_event_read_value_proto(void)610 const struct bpf_func_proto *bpf_get_perf_event_read_value_proto(void)
611 {
612 return &bpf_perf_event_read_value_proto;
613 }
614
615 static __always_inline u64
__bpf_perf_event_output(struct pt_regs * regs,struct bpf_map * map,u64 flags,struct perf_raw_record * raw,struct perf_sample_data * sd)616 __bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map,
617 u64 flags, struct perf_raw_record *raw,
618 struct perf_sample_data *sd)
619 {
620 struct bpf_array *array = container_of(map, struct bpf_array, map);
621 unsigned int cpu = smp_processor_id();
622 u64 index = flags & BPF_F_INDEX_MASK;
623 struct bpf_event_entry *ee;
624 struct perf_event *event;
625
626 if (index == BPF_F_CURRENT_CPU)
627 index = cpu;
628 if (unlikely(index >= array->map.max_entries))
629 return -E2BIG;
630
631 ee = READ_ONCE(array->ptrs[index]);
632 if (!ee)
633 return -ENOENT;
634
635 event = ee->event;
636 if (unlikely(event->attr.type != PERF_TYPE_SOFTWARE ||
637 event->attr.config != PERF_COUNT_SW_BPF_OUTPUT))
638 return -EINVAL;
639
640 if (unlikely(event->oncpu != cpu))
641 return -EOPNOTSUPP;
642
643 perf_sample_save_raw_data(sd, event, raw);
644
645 return perf_event_output(event, sd, regs);
646 }
647
648 /*
649 * Support executing tracepoints in normal, irq, and nmi context that each call
650 * bpf_perf_event_output
651 */
652 struct bpf_trace_sample_data {
653 struct perf_sample_data sds[3];
654 };
655
656 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_trace_sds);
657 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)658 BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map,
659 u64, flags, void *, data, u64, size)
660 {
661 struct bpf_trace_sample_data *sds;
662 struct perf_raw_record raw = {
663 .frag = {
664 .size = size,
665 .data = data,
666 },
667 };
668 struct perf_sample_data *sd;
669 int nest_level, err;
670
671 preempt_disable();
672 sds = this_cpu_ptr(&bpf_trace_sds);
673 nest_level = this_cpu_inc_return(bpf_trace_nest_level);
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
689 err = __bpf_perf_event_output(regs, map, flags, &raw, sd);
690 out:
691 this_cpu_dec(bpf_trace_nest_level);
692 preempt_enable();
693 return err;
694 }
695
696 static const struct bpf_func_proto bpf_perf_event_output_proto = {
697 .func = bpf_perf_event_output,
698 .gpl_only = true,
699 .ret_type = RET_INTEGER,
700 .arg1_type = ARG_PTR_TO_CTX,
701 .arg2_type = ARG_CONST_MAP_PTR,
702 .arg3_type = ARG_ANYTHING,
703 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY,
704 .arg5_type = ARG_CONST_SIZE_OR_ZERO,
705 };
706
707 static DEFINE_PER_CPU(int, bpf_event_output_nest_level);
708 struct bpf_nested_pt_regs {
709 struct pt_regs regs[3];
710 };
711 static DEFINE_PER_CPU(struct bpf_nested_pt_regs, bpf_pt_regs);
712 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_misc_sds);
713
bpf_event_output(struct bpf_map * map,u64 flags,void * meta,u64 meta_size,void * ctx,u64 ctx_size,bpf_ctx_copy_t ctx_copy)714 u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
715 void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy)
716 {
717 struct perf_raw_frag frag = {
718 .copy = ctx_copy,
719 .size = ctx_size,
720 .data = ctx,
721 };
722 struct perf_raw_record raw = {
723 .frag = {
724 {
725 .next = ctx_size ? &frag : NULL,
726 },
727 .size = meta_size,
728 .data = meta,
729 },
730 };
731 struct perf_sample_data *sd;
732 struct pt_regs *regs;
733 int nest_level;
734 u64 ret;
735
736 preempt_disable();
737 nest_level = this_cpu_inc_return(bpf_event_output_nest_level);
738
739 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(bpf_misc_sds.sds))) {
740 ret = -EBUSY;
741 goto out;
742 }
743 sd = this_cpu_ptr(&bpf_misc_sds.sds[nest_level - 1]);
744 regs = this_cpu_ptr(&bpf_pt_regs.regs[nest_level - 1]);
745
746 perf_fetch_caller_regs(regs);
747 perf_sample_data_init(sd, 0, 0);
748
749 ret = __bpf_perf_event_output(regs, map, flags, &raw, sd);
750 out:
751 this_cpu_dec(bpf_event_output_nest_level);
752 preempt_enable();
753 return ret;
754 }
755
BPF_CALL_0(bpf_get_current_task)756 BPF_CALL_0(bpf_get_current_task)
757 {
758 return (long) current;
759 }
760
761 const struct bpf_func_proto bpf_get_current_task_proto = {
762 .func = bpf_get_current_task,
763 .gpl_only = true,
764 .ret_type = RET_INTEGER,
765 };
766
BPF_CALL_0(bpf_get_current_task_btf)767 BPF_CALL_0(bpf_get_current_task_btf)
768 {
769 return (unsigned long) current;
770 }
771
772 const struct bpf_func_proto bpf_get_current_task_btf_proto = {
773 .func = bpf_get_current_task_btf,
774 .gpl_only = true,
775 .ret_type = RET_PTR_TO_BTF_ID_TRUSTED,
776 .ret_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK],
777 };
778
BPF_CALL_1(bpf_task_pt_regs,struct task_struct *,task)779 BPF_CALL_1(bpf_task_pt_regs, struct task_struct *, task)
780 {
781 return (unsigned long) task_pt_regs(task);
782 }
783
784 BTF_ID_LIST(bpf_task_pt_regs_ids)
785 BTF_ID(struct, pt_regs)
786
787 const struct bpf_func_proto bpf_task_pt_regs_proto = {
788 .func = bpf_task_pt_regs,
789 .gpl_only = true,
790 .arg1_type = ARG_PTR_TO_BTF_ID,
791 .arg1_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK],
792 .ret_type = RET_PTR_TO_BTF_ID,
793 .ret_btf_id = &bpf_task_pt_regs_ids[0],
794 };
795
796 struct send_signal_irq_work {
797 struct irq_work irq_work;
798 struct task_struct *task;
799 u32 sig;
800 enum pid_type type;
801 bool has_siginfo;
802 struct kernel_siginfo info;
803 };
804
805 static DEFINE_PER_CPU(struct send_signal_irq_work, send_signal_work);
806
do_bpf_send_signal(struct irq_work * entry)807 static void do_bpf_send_signal(struct irq_work *entry)
808 {
809 struct send_signal_irq_work *work;
810 struct kernel_siginfo *siginfo;
811
812 work = container_of(entry, struct send_signal_irq_work, irq_work);
813 siginfo = work->has_siginfo ? &work->info : SEND_SIG_PRIV;
814
815 group_send_sig_info(work->sig, siginfo, work->task, work->type);
816 put_task_struct(work->task);
817 }
818
bpf_send_signal_common(u32 sig,enum pid_type type,struct task_struct * task,u64 value)819 static int bpf_send_signal_common(u32 sig, enum pid_type type, struct task_struct *task, u64 value)
820 {
821 struct send_signal_irq_work *work = NULL;
822 struct kernel_siginfo info;
823 struct kernel_siginfo *siginfo;
824
825 if (!task) {
826 task = current;
827 siginfo = SEND_SIG_PRIV;
828 } else {
829 clear_siginfo(&info);
830 info.si_signo = sig;
831 info.si_errno = 0;
832 info.si_code = SI_KERNEL;
833 info.si_pid = 0;
834 info.si_uid = 0;
835 info.si_value.sival_ptr = (void *)(unsigned long)value;
836 siginfo = &info;
837 }
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(task->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(task)))
850 return -EPERM;
851
852 if (preempt_count() != 0 || 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(task);
868 work->has_siginfo = siginfo == &info;
869 if (work->has_siginfo)
870 copy_siginfo(&work->info, &info);
871 work->sig = sig;
872 work->type = type;
873 irq_work_queue(&work->irq_work);
874 return 0;
875 }
876
877 return group_send_sig_info(sig, siginfo, task, type);
878 }
879
BPF_CALL_1(bpf_send_signal,u32,sig)880 BPF_CALL_1(bpf_send_signal, u32, sig)
881 {
882 return bpf_send_signal_common(sig, PIDTYPE_TGID, NULL, 0);
883 }
884
885 static const struct bpf_func_proto bpf_send_signal_proto = {
886 .func = bpf_send_signal,
887 .gpl_only = false,
888 .ret_type = RET_INTEGER,
889 .arg1_type = ARG_ANYTHING,
890 };
891
BPF_CALL_1(bpf_send_signal_thread,u32,sig)892 BPF_CALL_1(bpf_send_signal_thread, u32, sig)
893 {
894 return bpf_send_signal_common(sig, PIDTYPE_PID, NULL, 0);
895 }
896
897 static const struct bpf_func_proto bpf_send_signal_thread_proto = {
898 .func = bpf_send_signal_thread,
899 .gpl_only = false,
900 .ret_type = RET_INTEGER,
901 .arg1_type = ARG_ANYTHING,
902 };
903
BPF_CALL_3(bpf_d_path,struct path *,path,char *,buf,u32,sz)904 BPF_CALL_3(bpf_d_path, struct path *, path, char *, buf, u32, sz)
905 {
906 struct path copy;
907 long len;
908 char *p;
909
910 if (!sz)
911 return 0;
912
913 /*
914 * The path pointer is verified as trusted and safe to use,
915 * but let's double check it's valid anyway to workaround
916 * potentially broken verifier.
917 */
918 len = copy_from_kernel_nofault(©, path, sizeof(*path));
919 if (len < 0)
920 return len;
921
922 p = d_path(©, buf, sz);
923 if (IS_ERR(p)) {
924 len = PTR_ERR(p);
925 } else {
926 len = buf + sz - p;
927 memmove(buf, p, len);
928 }
929
930 return len;
931 }
932
933 BTF_SET_START(btf_allowlist_d_path)
934 #ifdef CONFIG_SECURITY
BTF_ID(func,security_file_permission)935 BTF_ID(func, security_file_permission)
936 BTF_ID(func, security_inode_getattr)
937 BTF_ID(func, security_file_open)
938 #endif
939 #ifdef CONFIG_SECURITY_PATH
940 BTF_ID(func, security_path_truncate)
941 #endif
942 BTF_ID(func, vfs_truncate)
943 BTF_ID(func, vfs_fallocate)
944 BTF_ID(func, dentry_open)
945 BTF_ID(func, vfs_getattr)
946 BTF_ID(func, filp_close)
947 BTF_SET_END(btf_allowlist_d_path)
948
949 static bool bpf_d_path_allowed(const struct bpf_prog *prog)
950 {
951 if (prog->type == BPF_PROG_TYPE_TRACING &&
952 prog->expected_attach_type == BPF_TRACE_ITER)
953 return true;
954
955 if (prog->type == BPF_PROG_TYPE_LSM)
956 return bpf_lsm_is_sleepable_hook(prog->aux->attach_btf_id);
957
958 return btf_id_set_contains(&btf_allowlist_d_path,
959 prog->aux->attach_btf_id);
960 }
961
962 BTF_ID_LIST_SINGLE(bpf_d_path_btf_ids, struct, path)
963
964 static const struct bpf_func_proto bpf_d_path_proto = {
965 .func = bpf_d_path,
966 .gpl_only = false,
967 .ret_type = RET_INTEGER,
968 .arg1_type = ARG_PTR_TO_BTF_ID,
969 .arg1_btf_id = &bpf_d_path_btf_ids[0],
970 .arg2_type = ARG_PTR_TO_MEM,
971 .arg3_type = ARG_CONST_SIZE_OR_ZERO,
972 .allowed = bpf_d_path_allowed,
973 };
974
975 #define BTF_F_ALL (BTF_F_COMPACT | BTF_F_NONAME | \
976 BTF_F_PTR_RAW | BTF_F_ZERO)
977
bpf_btf_printf_prepare(struct btf_ptr * ptr,u32 btf_ptr_size,u64 flags,const struct btf ** btf,s32 * btf_id)978 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size,
979 u64 flags, const struct btf **btf,
980 s32 *btf_id)
981 {
982 const struct btf_type *t;
983
984 if (unlikely(flags & ~(BTF_F_ALL)))
985 return -EINVAL;
986
987 if (btf_ptr_size != sizeof(struct btf_ptr))
988 return -EINVAL;
989
990 *btf = bpf_get_btf_vmlinux();
991
992 if (IS_ERR_OR_NULL(*btf))
993 return IS_ERR(*btf) ? PTR_ERR(*btf) : -EINVAL;
994
995 if (ptr->type_id > 0)
996 *btf_id = ptr->type_id;
997 else
998 return -EINVAL;
999
1000 if (*btf_id > 0)
1001 t = btf_type_by_id(*btf, *btf_id);
1002 if (*btf_id <= 0 || !t)
1003 return -ENOENT;
1004
1005 return 0;
1006 }
1007
BPF_CALL_5(bpf_snprintf_btf,char *,str,u32,str_size,struct btf_ptr *,ptr,u32,btf_ptr_size,u64,flags)1008 BPF_CALL_5(bpf_snprintf_btf, char *, str, u32, str_size, struct btf_ptr *, ptr,
1009 u32, btf_ptr_size, u64, flags)
1010 {
1011 const struct btf *btf;
1012 s32 btf_id;
1013 int ret;
1014
1015 ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id);
1016 if (ret)
1017 return ret;
1018
1019 return btf_type_snprintf_show(btf, btf_id, ptr->ptr, str, str_size,
1020 flags);
1021 }
1022
1023 const struct bpf_func_proto bpf_snprintf_btf_proto = {
1024 .func = bpf_snprintf_btf,
1025 .gpl_only = false,
1026 .ret_type = RET_INTEGER,
1027 .arg1_type = ARG_PTR_TO_MEM,
1028 .arg2_type = ARG_CONST_SIZE,
1029 .arg3_type = ARG_PTR_TO_MEM | MEM_RDONLY,
1030 .arg4_type = ARG_CONST_SIZE,
1031 .arg5_type = ARG_ANYTHING,
1032 };
1033
BPF_CALL_1(bpf_get_func_ip_tracing,void *,ctx)1034 BPF_CALL_1(bpf_get_func_ip_tracing, void *, ctx)
1035 {
1036 /* This helper call is inlined by verifier. */
1037 return ((u64 *)ctx)[-2];
1038 }
1039
1040 static const struct bpf_func_proto bpf_get_func_ip_proto_tracing = {
1041 .func = bpf_get_func_ip_tracing,
1042 .gpl_only = true,
1043 .ret_type = RET_INTEGER,
1044 .arg1_type = ARG_PTR_TO_CTX,
1045 };
1046
get_entry_ip(unsigned long fentry_ip)1047 static inline unsigned long get_entry_ip(unsigned long fentry_ip)
1048 {
1049 #ifdef CONFIG_X86_KERNEL_IBT
1050 if (is_endbr((void *)(fentry_ip - ENDBR_INSN_SIZE)))
1051 fentry_ip -= ENDBR_INSN_SIZE;
1052 #endif
1053 return fentry_ip;
1054 }
1055
BPF_CALL_1(bpf_get_func_ip_kprobe,struct pt_regs *,regs)1056 BPF_CALL_1(bpf_get_func_ip_kprobe, struct pt_regs *, regs)
1057 {
1058 struct bpf_trace_run_ctx *run_ctx __maybe_unused;
1059 struct kprobe *kp;
1060
1061 #ifdef CONFIG_UPROBES
1062 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx);
1063 if (run_ctx->is_uprobe)
1064 return ((struct uprobe_dispatch_data *)current->utask->vaddr)->bp_addr;
1065 #endif
1066
1067 kp = kprobe_running();
1068
1069 if (!kp || !(kp->flags & KPROBE_FLAG_ON_FUNC_ENTRY))
1070 return 0;
1071
1072 return get_entry_ip((uintptr_t)kp->addr);
1073 }
1074
1075 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe = {
1076 .func = bpf_get_func_ip_kprobe,
1077 .gpl_only = true,
1078 .ret_type = RET_INTEGER,
1079 .arg1_type = ARG_PTR_TO_CTX,
1080 };
1081
BPF_CALL_1(bpf_get_func_ip_kprobe_multi,struct pt_regs *,regs)1082 BPF_CALL_1(bpf_get_func_ip_kprobe_multi, struct pt_regs *, regs)
1083 {
1084 return bpf_kprobe_multi_entry_ip(current->bpf_ctx);
1085 }
1086
1087 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe_multi = {
1088 .func = bpf_get_func_ip_kprobe_multi,
1089 .gpl_only = false,
1090 .ret_type = RET_INTEGER,
1091 .arg1_type = ARG_PTR_TO_CTX,
1092 };
1093
BPF_CALL_1(bpf_get_attach_cookie_kprobe_multi,struct pt_regs *,regs)1094 BPF_CALL_1(bpf_get_attach_cookie_kprobe_multi, struct pt_regs *, regs)
1095 {
1096 return bpf_kprobe_multi_cookie(current->bpf_ctx);
1097 }
1098
1099 static const struct bpf_func_proto bpf_get_attach_cookie_proto_kmulti = {
1100 .func = bpf_get_attach_cookie_kprobe_multi,
1101 .gpl_only = false,
1102 .ret_type = RET_INTEGER,
1103 .arg1_type = ARG_PTR_TO_CTX,
1104 };
1105
BPF_CALL_1(bpf_get_func_ip_uprobe_multi,struct pt_regs *,regs)1106 BPF_CALL_1(bpf_get_func_ip_uprobe_multi, struct pt_regs *, regs)
1107 {
1108 return bpf_uprobe_multi_entry_ip(current->bpf_ctx);
1109 }
1110
1111 static const struct bpf_func_proto bpf_get_func_ip_proto_uprobe_multi = {
1112 .func = bpf_get_func_ip_uprobe_multi,
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_uprobe_multi,struct pt_regs *,regs)1118 BPF_CALL_1(bpf_get_attach_cookie_uprobe_multi, struct pt_regs *, regs)
1119 {
1120 return bpf_uprobe_multi_cookie(current->bpf_ctx);
1121 }
1122
1123 static const struct bpf_func_proto bpf_get_attach_cookie_proto_umulti = {
1124 .func = bpf_get_attach_cookie_uprobe_multi,
1125 .gpl_only = false,
1126 .ret_type = RET_INTEGER,
1127 .arg1_type = ARG_PTR_TO_CTX,
1128 };
1129
BPF_CALL_1(bpf_get_attach_cookie_trace,void *,ctx)1130 BPF_CALL_1(bpf_get_attach_cookie_trace, void *, ctx)
1131 {
1132 struct bpf_trace_run_ctx *run_ctx;
1133
1134 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx);
1135 return run_ctx->bpf_cookie;
1136 }
1137
1138 static const struct bpf_func_proto bpf_get_attach_cookie_proto_trace = {
1139 .func = bpf_get_attach_cookie_trace,
1140 .gpl_only = false,
1141 .ret_type = RET_INTEGER,
1142 .arg1_type = ARG_PTR_TO_CTX,
1143 };
1144
BPF_CALL_1(bpf_get_attach_cookie_pe,struct bpf_perf_event_data_kern *,ctx)1145 BPF_CALL_1(bpf_get_attach_cookie_pe, struct bpf_perf_event_data_kern *, ctx)
1146 {
1147 return ctx->event->bpf_cookie;
1148 }
1149
1150 static const struct bpf_func_proto bpf_get_attach_cookie_proto_pe = {
1151 .func = bpf_get_attach_cookie_pe,
1152 .gpl_only = false,
1153 .ret_type = RET_INTEGER,
1154 .arg1_type = ARG_PTR_TO_CTX,
1155 };
1156
BPF_CALL_1(bpf_get_attach_cookie_tracing,void *,ctx)1157 BPF_CALL_1(bpf_get_attach_cookie_tracing, void *, ctx)
1158 {
1159 struct bpf_trace_run_ctx *run_ctx;
1160
1161 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx);
1162 return run_ctx->bpf_cookie;
1163 }
1164
1165 static const struct bpf_func_proto bpf_get_attach_cookie_proto_tracing = {
1166 .func = bpf_get_attach_cookie_tracing,
1167 .gpl_only = false,
1168 .ret_type = RET_INTEGER,
1169 .arg1_type = ARG_PTR_TO_CTX,
1170 };
1171
BPF_CALL_3(bpf_get_branch_snapshot,void *,buf,u32,size,u64,flags)1172 BPF_CALL_3(bpf_get_branch_snapshot, void *, buf, u32, size, u64, flags)
1173 {
1174 static const u32 br_entry_size = sizeof(struct perf_branch_entry);
1175 u32 entry_cnt = size / br_entry_size;
1176
1177 entry_cnt = static_call(perf_snapshot_branch_stack)(buf, entry_cnt);
1178
1179 if (unlikely(flags))
1180 return -EINVAL;
1181
1182 if (!entry_cnt)
1183 return -ENOENT;
1184
1185 return entry_cnt * br_entry_size;
1186 }
1187
1188 static const struct bpf_func_proto bpf_get_branch_snapshot_proto = {
1189 .func = bpf_get_branch_snapshot,
1190 .gpl_only = true,
1191 .ret_type = RET_INTEGER,
1192 .arg1_type = ARG_PTR_TO_UNINIT_MEM,
1193 .arg2_type = ARG_CONST_SIZE_OR_ZERO,
1194 };
1195
BPF_CALL_3(get_func_arg,void *,ctx,u32,n,u64 *,value)1196 BPF_CALL_3(get_func_arg, void *, ctx, u32, n, u64 *, value)
1197 {
1198 /* This helper call is inlined by verifier. */
1199 u64 nr_args = ((u64 *)ctx)[-1];
1200
1201 if ((u64) n >= nr_args)
1202 return -EINVAL;
1203 *value = ((u64 *)ctx)[n];
1204 return 0;
1205 }
1206
1207 static const struct bpf_func_proto bpf_get_func_arg_proto = {
1208 .func = get_func_arg,
1209 .ret_type = RET_INTEGER,
1210 .arg1_type = ARG_PTR_TO_CTX,
1211 .arg2_type = ARG_ANYTHING,
1212 .arg3_type = ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED,
1213 .arg3_size = sizeof(u64),
1214 };
1215
BPF_CALL_2(get_func_ret,void *,ctx,u64 *,value)1216 BPF_CALL_2(get_func_ret, void *, ctx, u64 *, value)
1217 {
1218 /* This helper call is inlined by verifier. */
1219 u64 nr_args = ((u64 *)ctx)[-1];
1220
1221 *value = ((u64 *)ctx)[nr_args];
1222 return 0;
1223 }
1224
1225 static const struct bpf_func_proto bpf_get_func_ret_proto = {
1226 .func = get_func_ret,
1227 .ret_type = RET_INTEGER,
1228 .arg1_type = ARG_PTR_TO_CTX,
1229 .arg2_type = ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED,
1230 .arg2_size = sizeof(u64),
1231 };
1232
BPF_CALL_1(get_func_arg_cnt,void *,ctx)1233 BPF_CALL_1(get_func_arg_cnt, void *, ctx)
1234 {
1235 /* This helper call is inlined by verifier. */
1236 return ((u64 *)ctx)[-1];
1237 }
1238
1239 static const struct bpf_func_proto bpf_get_func_arg_cnt_proto = {
1240 .func = get_func_arg_cnt,
1241 .ret_type = RET_INTEGER,
1242 .arg1_type = ARG_PTR_TO_CTX,
1243 };
1244
1245 #ifdef CONFIG_KEYS
1246 __bpf_kfunc_start_defs();
1247
1248 /**
1249 * bpf_lookup_user_key - lookup a key by its serial
1250 * @serial: key handle serial number
1251 * @flags: lookup-specific flags
1252 *
1253 * Search a key with a given *serial* and the provided *flags*.
1254 * If found, increment the reference count of the key by one, and
1255 * return it in the bpf_key structure.
1256 *
1257 * The bpf_key structure must be passed to bpf_key_put() when done
1258 * with it, so that the key reference count is decremented and the
1259 * bpf_key structure is freed.
1260 *
1261 * Permission checks are deferred to the time the key is used by
1262 * one of the available key-specific kfuncs.
1263 *
1264 * Set *flags* with KEY_LOOKUP_CREATE, to attempt creating a requested
1265 * special keyring (e.g. session keyring), if it doesn't yet exist.
1266 * Set *flags* with KEY_LOOKUP_PARTIAL, to lookup a key without waiting
1267 * for the key construction, and to retrieve uninstantiated keys (keys
1268 * without data attached to them).
1269 *
1270 * Return: a bpf_key pointer with a valid key pointer if the key is found, a
1271 * NULL pointer otherwise.
1272 */
bpf_lookup_user_key(u32 serial,u64 flags)1273 __bpf_kfunc struct bpf_key *bpf_lookup_user_key(u32 serial, u64 flags)
1274 {
1275 key_ref_t key_ref;
1276 struct bpf_key *bkey;
1277
1278 if (flags & ~KEY_LOOKUP_ALL)
1279 return NULL;
1280
1281 /*
1282 * Permission check is deferred until the key is used, as the
1283 * intent of the caller is unknown here.
1284 */
1285 key_ref = lookup_user_key(serial, flags, KEY_DEFER_PERM_CHECK);
1286 if (IS_ERR(key_ref))
1287 return NULL;
1288
1289 bkey = kmalloc(sizeof(*bkey), GFP_KERNEL);
1290 if (!bkey) {
1291 key_put(key_ref_to_ptr(key_ref));
1292 return NULL;
1293 }
1294
1295 bkey->key = key_ref_to_ptr(key_ref);
1296 bkey->has_ref = true;
1297
1298 return bkey;
1299 }
1300
1301 /**
1302 * bpf_lookup_system_key - lookup a key by a system-defined ID
1303 * @id: key ID
1304 *
1305 * Obtain a bpf_key structure with a key pointer set to the passed key ID.
1306 * The key pointer is marked as invalid, to prevent bpf_key_put() from
1307 * attempting to decrement the key reference count on that pointer. The key
1308 * pointer set in such way is currently understood only by
1309 * verify_pkcs7_signature().
1310 *
1311 * Set *id* to one of the values defined in include/linux/verification.h:
1312 * 0 for the primary keyring (immutable keyring of system keys);
1313 * VERIFY_USE_SECONDARY_KEYRING for both the primary and secondary keyring
1314 * (where keys can be added only if they are vouched for by existing keys
1315 * in those keyrings); VERIFY_USE_PLATFORM_KEYRING for the platform
1316 * keyring (primarily used by the integrity subsystem to verify a kexec'ed
1317 * kerned image and, possibly, the initramfs signature).
1318 *
1319 * Return: a bpf_key pointer with an invalid key pointer set from the
1320 * pre-determined ID on success, a NULL pointer otherwise
1321 */
bpf_lookup_system_key(u64 id)1322 __bpf_kfunc struct bpf_key *bpf_lookup_system_key(u64 id)
1323 {
1324 struct bpf_key *bkey;
1325
1326 if (system_keyring_id_check(id) < 0)
1327 return NULL;
1328
1329 bkey = kmalloc(sizeof(*bkey), GFP_ATOMIC);
1330 if (!bkey)
1331 return NULL;
1332
1333 bkey->key = (struct key *)(unsigned long)id;
1334 bkey->has_ref = false;
1335
1336 return bkey;
1337 }
1338
1339 /**
1340 * bpf_key_put - decrement key reference count if key is valid and free bpf_key
1341 * @bkey: bpf_key structure
1342 *
1343 * Decrement the reference count of the key inside *bkey*, if the pointer
1344 * is valid, and free *bkey*.
1345 */
bpf_key_put(struct bpf_key * bkey)1346 __bpf_kfunc void bpf_key_put(struct bpf_key *bkey)
1347 {
1348 if (bkey->has_ref)
1349 key_put(bkey->key);
1350
1351 kfree(bkey);
1352 }
1353
1354 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION
1355 /**
1356 * bpf_verify_pkcs7_signature - verify a PKCS#7 signature
1357 * @data_p: data to verify
1358 * @sig_p: signature of the data
1359 * @trusted_keyring: keyring with keys trusted for signature verification
1360 *
1361 * Verify the PKCS#7 signature *sig_ptr* against the supplied *data_ptr*
1362 * with keys in a keyring referenced by *trusted_keyring*.
1363 *
1364 * Return: 0 on success, a negative value on error.
1365 */
bpf_verify_pkcs7_signature(struct bpf_dynptr * data_p,struct bpf_dynptr * sig_p,struct bpf_key * trusted_keyring)1366 __bpf_kfunc int bpf_verify_pkcs7_signature(struct bpf_dynptr *data_p,
1367 struct bpf_dynptr *sig_p,
1368 struct bpf_key *trusted_keyring)
1369 {
1370 struct bpf_dynptr_kern *data_ptr = (struct bpf_dynptr_kern *)data_p;
1371 struct bpf_dynptr_kern *sig_ptr = (struct bpf_dynptr_kern *)sig_p;
1372 const void *data, *sig;
1373 u32 data_len, sig_len;
1374 int ret;
1375
1376 if (trusted_keyring->has_ref) {
1377 /*
1378 * Do the permission check deferred in bpf_lookup_user_key().
1379 * See bpf_lookup_user_key() for more details.
1380 *
1381 * A call to key_task_permission() here would be redundant, as
1382 * it is already done by keyring_search() called by
1383 * find_asymmetric_key().
1384 */
1385 ret = key_validate(trusted_keyring->key);
1386 if (ret < 0)
1387 return ret;
1388 }
1389
1390 data_len = __bpf_dynptr_size(data_ptr);
1391 data = __bpf_dynptr_data(data_ptr, data_len);
1392 sig_len = __bpf_dynptr_size(sig_ptr);
1393 sig = __bpf_dynptr_data(sig_ptr, sig_len);
1394
1395 return verify_pkcs7_signature(data, data_len, sig, sig_len,
1396 trusted_keyring->key,
1397 VERIFYING_UNSPECIFIED_SIGNATURE, NULL,
1398 NULL);
1399 }
1400 #endif /* CONFIG_SYSTEM_DATA_VERIFICATION */
1401
1402 __bpf_kfunc_end_defs();
1403
1404 BTF_KFUNCS_START(key_sig_kfunc_set)
1405 BTF_ID_FLAGS(func, bpf_lookup_user_key, KF_ACQUIRE | KF_RET_NULL | KF_SLEEPABLE)
1406 BTF_ID_FLAGS(func, bpf_lookup_system_key, KF_ACQUIRE | KF_RET_NULL)
1407 BTF_ID_FLAGS(func, bpf_key_put, KF_RELEASE)
1408 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION
1409 BTF_ID_FLAGS(func, bpf_verify_pkcs7_signature, KF_SLEEPABLE)
1410 #endif
1411 BTF_KFUNCS_END(key_sig_kfunc_set)
1412
1413 static const struct btf_kfunc_id_set bpf_key_sig_kfunc_set = {
1414 .owner = THIS_MODULE,
1415 .set = &key_sig_kfunc_set,
1416 };
1417
bpf_key_sig_kfuncs_init(void)1418 static int __init bpf_key_sig_kfuncs_init(void)
1419 {
1420 return register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING,
1421 &bpf_key_sig_kfunc_set);
1422 }
1423
1424 late_initcall(bpf_key_sig_kfuncs_init);
1425 #endif /* CONFIG_KEYS */
1426
1427 static const struct bpf_func_proto *
bpf_tracing_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1428 bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1429 {
1430 const struct bpf_func_proto *func_proto;
1431
1432 switch (func_id) {
1433 case BPF_FUNC_map_lookup_elem:
1434 return &bpf_map_lookup_elem_proto;
1435 case BPF_FUNC_map_update_elem:
1436 return &bpf_map_update_elem_proto;
1437 case BPF_FUNC_map_delete_elem:
1438 return &bpf_map_delete_elem_proto;
1439 case BPF_FUNC_map_push_elem:
1440 return &bpf_map_push_elem_proto;
1441 case BPF_FUNC_map_pop_elem:
1442 return &bpf_map_pop_elem_proto;
1443 case BPF_FUNC_map_peek_elem:
1444 return &bpf_map_peek_elem_proto;
1445 case BPF_FUNC_map_lookup_percpu_elem:
1446 return &bpf_map_lookup_percpu_elem_proto;
1447 case BPF_FUNC_ktime_get_ns:
1448 return &bpf_ktime_get_ns_proto;
1449 case BPF_FUNC_ktime_get_boot_ns:
1450 return &bpf_ktime_get_boot_ns_proto;
1451 case BPF_FUNC_tail_call:
1452 return &bpf_tail_call_proto;
1453 case BPF_FUNC_get_current_task:
1454 return &bpf_get_current_task_proto;
1455 case BPF_FUNC_get_current_task_btf:
1456 return &bpf_get_current_task_btf_proto;
1457 case BPF_FUNC_task_pt_regs:
1458 return &bpf_task_pt_regs_proto;
1459 case BPF_FUNC_get_current_uid_gid:
1460 return &bpf_get_current_uid_gid_proto;
1461 case BPF_FUNC_get_current_comm:
1462 return &bpf_get_current_comm_proto;
1463 case BPF_FUNC_trace_printk:
1464 return bpf_get_trace_printk_proto();
1465 case BPF_FUNC_get_smp_processor_id:
1466 return &bpf_get_smp_processor_id_proto;
1467 case BPF_FUNC_get_numa_node_id:
1468 return &bpf_get_numa_node_id_proto;
1469 case BPF_FUNC_perf_event_read:
1470 return &bpf_perf_event_read_proto;
1471 case BPF_FUNC_get_prandom_u32:
1472 return &bpf_get_prandom_u32_proto;
1473 case BPF_FUNC_probe_read_user:
1474 return &bpf_probe_read_user_proto;
1475 case BPF_FUNC_probe_read_kernel:
1476 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
1477 NULL : &bpf_probe_read_kernel_proto;
1478 case BPF_FUNC_probe_read_user_str:
1479 return &bpf_probe_read_user_str_proto;
1480 case BPF_FUNC_probe_read_kernel_str:
1481 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
1482 NULL : &bpf_probe_read_kernel_str_proto;
1483 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
1484 case BPF_FUNC_probe_read:
1485 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
1486 NULL : &bpf_probe_read_compat_proto;
1487 case BPF_FUNC_probe_read_str:
1488 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
1489 NULL : &bpf_probe_read_compat_str_proto;
1490 #endif
1491 #ifdef CONFIG_CGROUPS
1492 case BPF_FUNC_cgrp_storage_get:
1493 return &bpf_cgrp_storage_get_proto;
1494 case BPF_FUNC_cgrp_storage_delete:
1495 return &bpf_cgrp_storage_delete_proto;
1496 case BPF_FUNC_current_task_under_cgroup:
1497 return &bpf_current_task_under_cgroup_proto;
1498 #endif
1499 case BPF_FUNC_send_signal:
1500 return &bpf_send_signal_proto;
1501 case BPF_FUNC_send_signal_thread:
1502 return &bpf_send_signal_thread_proto;
1503 case BPF_FUNC_perf_event_read_value:
1504 return &bpf_perf_event_read_value_proto;
1505 case BPF_FUNC_ringbuf_output:
1506 return &bpf_ringbuf_output_proto;
1507 case BPF_FUNC_ringbuf_reserve:
1508 return &bpf_ringbuf_reserve_proto;
1509 case BPF_FUNC_ringbuf_submit:
1510 return &bpf_ringbuf_submit_proto;
1511 case BPF_FUNC_ringbuf_discard:
1512 return &bpf_ringbuf_discard_proto;
1513 case BPF_FUNC_ringbuf_query:
1514 return &bpf_ringbuf_query_proto;
1515 case BPF_FUNC_jiffies64:
1516 return &bpf_jiffies64_proto;
1517 case BPF_FUNC_get_task_stack:
1518 return prog->sleepable ? &bpf_get_task_stack_sleepable_proto
1519 : &bpf_get_task_stack_proto;
1520 case BPF_FUNC_copy_from_user:
1521 return &bpf_copy_from_user_proto;
1522 case BPF_FUNC_copy_from_user_task:
1523 return &bpf_copy_from_user_task_proto;
1524 case BPF_FUNC_snprintf_btf:
1525 return &bpf_snprintf_btf_proto;
1526 case BPF_FUNC_per_cpu_ptr:
1527 return &bpf_per_cpu_ptr_proto;
1528 case BPF_FUNC_this_cpu_ptr:
1529 return &bpf_this_cpu_ptr_proto;
1530 case BPF_FUNC_task_storage_get:
1531 if (bpf_prog_check_recur(prog))
1532 return &bpf_task_storage_get_recur_proto;
1533 return &bpf_task_storage_get_proto;
1534 case BPF_FUNC_task_storage_delete:
1535 if (bpf_prog_check_recur(prog))
1536 return &bpf_task_storage_delete_recur_proto;
1537 return &bpf_task_storage_delete_proto;
1538 case BPF_FUNC_for_each_map_elem:
1539 return &bpf_for_each_map_elem_proto;
1540 case BPF_FUNC_snprintf:
1541 return &bpf_snprintf_proto;
1542 case BPF_FUNC_get_func_ip:
1543 return &bpf_get_func_ip_proto_tracing;
1544 case BPF_FUNC_get_branch_snapshot:
1545 return &bpf_get_branch_snapshot_proto;
1546 case BPF_FUNC_find_vma:
1547 return &bpf_find_vma_proto;
1548 case BPF_FUNC_trace_vprintk:
1549 return bpf_get_trace_vprintk_proto();
1550 default:
1551 break;
1552 }
1553
1554 func_proto = bpf_base_func_proto(func_id, prog);
1555 if (func_proto)
1556 return func_proto;
1557
1558 if (!bpf_token_capable(prog->aux->token, CAP_SYS_ADMIN))
1559 return NULL;
1560
1561 switch (func_id) {
1562 case BPF_FUNC_probe_write_user:
1563 return security_locked_down(LOCKDOWN_BPF_WRITE_USER) < 0 ?
1564 NULL : &bpf_probe_write_user_proto;
1565 default:
1566 return NULL;
1567 }
1568 }
1569
is_kprobe_multi(const struct bpf_prog * prog)1570 static bool is_kprobe_multi(const struct bpf_prog *prog)
1571 {
1572 return prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI ||
1573 prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION;
1574 }
1575
is_kprobe_session(const struct bpf_prog * prog)1576 static inline bool is_kprobe_session(const struct bpf_prog *prog)
1577 {
1578 return prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION;
1579 }
1580
is_uprobe_multi(const struct bpf_prog * prog)1581 static inline bool is_uprobe_multi(const struct bpf_prog *prog)
1582 {
1583 return prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI ||
1584 prog->expected_attach_type == BPF_TRACE_UPROBE_SESSION;
1585 }
1586
is_uprobe_session(const struct bpf_prog * prog)1587 static inline bool is_uprobe_session(const struct bpf_prog *prog)
1588 {
1589 return prog->expected_attach_type == BPF_TRACE_UPROBE_SESSION;
1590 }
1591
1592 static const struct bpf_func_proto *
kprobe_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1593 kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1594 {
1595 switch (func_id) {
1596 case BPF_FUNC_perf_event_output:
1597 return &bpf_perf_event_output_proto;
1598 case BPF_FUNC_get_stackid:
1599 return &bpf_get_stackid_proto;
1600 case BPF_FUNC_get_stack:
1601 return prog->sleepable ? &bpf_get_stack_sleepable_proto : &bpf_get_stack_proto;
1602 #ifdef CONFIG_BPF_KPROBE_OVERRIDE
1603 case BPF_FUNC_override_return:
1604 return &bpf_override_return_proto;
1605 #endif
1606 case BPF_FUNC_get_func_ip:
1607 if (is_kprobe_multi(prog))
1608 return &bpf_get_func_ip_proto_kprobe_multi;
1609 if (is_uprobe_multi(prog))
1610 return &bpf_get_func_ip_proto_uprobe_multi;
1611 return &bpf_get_func_ip_proto_kprobe;
1612 case BPF_FUNC_get_attach_cookie:
1613 if (is_kprobe_multi(prog))
1614 return &bpf_get_attach_cookie_proto_kmulti;
1615 if (is_uprobe_multi(prog))
1616 return &bpf_get_attach_cookie_proto_umulti;
1617 return &bpf_get_attach_cookie_proto_trace;
1618 default:
1619 return bpf_tracing_func_proto(func_id, prog);
1620 }
1621 }
1622
1623 /* 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)1624 static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
1625 const struct bpf_prog *prog,
1626 struct bpf_insn_access_aux *info)
1627 {
1628 if (off < 0 || off >= sizeof(struct pt_regs))
1629 return false;
1630 if (type != BPF_READ)
1631 return false;
1632 if (off % size != 0)
1633 return false;
1634 /*
1635 * Assertion for 32 bit to make sure last 8 byte access
1636 * (BPF_DW) to the last 4 byte member is disallowed.
1637 */
1638 if (off + size > sizeof(struct pt_regs))
1639 return false;
1640
1641 return true;
1642 }
1643
1644 const struct bpf_verifier_ops kprobe_verifier_ops = {
1645 .get_func_proto = kprobe_prog_func_proto,
1646 .is_valid_access = kprobe_prog_is_valid_access,
1647 };
1648
1649 const struct bpf_prog_ops kprobe_prog_ops = {
1650 };
1651
BPF_CALL_5(bpf_perf_event_output_tp,void *,tp_buff,struct bpf_map *,map,u64,flags,void *,data,u64,size)1652 BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map,
1653 u64, flags, void *, data, u64, size)
1654 {
1655 struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1656
1657 /*
1658 * r1 points to perf tracepoint buffer where first 8 bytes are hidden
1659 * from bpf program and contain a pointer to 'struct pt_regs'. Fetch it
1660 * from there and call the same bpf_perf_event_output() helper inline.
1661 */
1662 return ____bpf_perf_event_output(regs, map, flags, data, size);
1663 }
1664
1665 static const struct bpf_func_proto bpf_perf_event_output_proto_tp = {
1666 .func = bpf_perf_event_output_tp,
1667 .gpl_only = true,
1668 .ret_type = RET_INTEGER,
1669 .arg1_type = ARG_PTR_TO_CTX,
1670 .arg2_type = ARG_CONST_MAP_PTR,
1671 .arg3_type = ARG_ANYTHING,
1672 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY,
1673 .arg5_type = ARG_CONST_SIZE_OR_ZERO,
1674 };
1675
BPF_CALL_3(bpf_get_stackid_tp,void *,tp_buff,struct bpf_map *,map,u64,flags)1676 BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map,
1677 u64, flags)
1678 {
1679 struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1680
1681 /*
1682 * Same comment as in bpf_perf_event_output_tp(), only that this time
1683 * the other helper's function body cannot be inlined due to being
1684 * external, thus we need to call raw helper function.
1685 */
1686 return bpf_get_stackid((unsigned long) regs, (unsigned long) map,
1687 flags, 0, 0);
1688 }
1689
1690 static const struct bpf_func_proto bpf_get_stackid_proto_tp = {
1691 .func = bpf_get_stackid_tp,
1692 .gpl_only = true,
1693 .ret_type = RET_INTEGER,
1694 .arg1_type = ARG_PTR_TO_CTX,
1695 .arg2_type = ARG_CONST_MAP_PTR,
1696 .arg3_type = ARG_ANYTHING,
1697 };
1698
BPF_CALL_4(bpf_get_stack_tp,void *,tp_buff,void *,buf,u32,size,u64,flags)1699 BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size,
1700 u64, flags)
1701 {
1702 struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1703
1704 return bpf_get_stack((unsigned long) regs, (unsigned long) buf,
1705 (unsigned long) size, flags, 0);
1706 }
1707
1708 static const struct bpf_func_proto bpf_get_stack_proto_tp = {
1709 .func = bpf_get_stack_tp,
1710 .gpl_only = true,
1711 .ret_type = RET_INTEGER,
1712 .arg1_type = ARG_PTR_TO_CTX,
1713 .arg2_type = ARG_PTR_TO_UNINIT_MEM,
1714 .arg3_type = ARG_CONST_SIZE_OR_ZERO,
1715 .arg4_type = ARG_ANYTHING,
1716 };
1717
1718 static const struct bpf_func_proto *
tp_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1719 tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1720 {
1721 switch (func_id) {
1722 case BPF_FUNC_perf_event_output:
1723 return &bpf_perf_event_output_proto_tp;
1724 case BPF_FUNC_get_stackid:
1725 return &bpf_get_stackid_proto_tp;
1726 case BPF_FUNC_get_stack:
1727 return &bpf_get_stack_proto_tp;
1728 case BPF_FUNC_get_attach_cookie:
1729 return &bpf_get_attach_cookie_proto_trace;
1730 default:
1731 return bpf_tracing_func_proto(func_id, prog);
1732 }
1733 }
1734
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)1735 static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type,
1736 const struct bpf_prog *prog,
1737 struct bpf_insn_access_aux *info)
1738 {
1739 if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE)
1740 return false;
1741 if (type != BPF_READ)
1742 return false;
1743 if (off % size != 0)
1744 return false;
1745
1746 BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(__u64));
1747 return true;
1748 }
1749
1750 const struct bpf_verifier_ops tracepoint_verifier_ops = {
1751 .get_func_proto = tp_prog_func_proto,
1752 .is_valid_access = tp_prog_is_valid_access,
1753 };
1754
1755 const struct bpf_prog_ops tracepoint_prog_ops = {
1756 };
1757
BPF_CALL_3(bpf_perf_prog_read_value,struct bpf_perf_event_data_kern *,ctx,struct bpf_perf_event_value *,buf,u32,size)1758 BPF_CALL_3(bpf_perf_prog_read_value, struct bpf_perf_event_data_kern *, ctx,
1759 struct bpf_perf_event_value *, buf, u32, size)
1760 {
1761 int err = -EINVAL;
1762
1763 if (unlikely(size != sizeof(struct bpf_perf_event_value)))
1764 goto clear;
1765 err = perf_event_read_local(ctx->event, &buf->counter, &buf->enabled,
1766 &buf->running);
1767 if (unlikely(err))
1768 goto clear;
1769 return 0;
1770 clear:
1771 memset(buf, 0, size);
1772 return err;
1773 }
1774
1775 static const struct bpf_func_proto bpf_perf_prog_read_value_proto = {
1776 .func = bpf_perf_prog_read_value,
1777 .gpl_only = true,
1778 .ret_type = RET_INTEGER,
1779 .arg1_type = ARG_PTR_TO_CTX,
1780 .arg2_type = ARG_PTR_TO_UNINIT_MEM,
1781 .arg3_type = ARG_CONST_SIZE,
1782 };
1783
BPF_CALL_4(bpf_read_branch_records,struct bpf_perf_event_data_kern *,ctx,void *,buf,u32,size,u64,flags)1784 BPF_CALL_4(bpf_read_branch_records, struct bpf_perf_event_data_kern *, ctx,
1785 void *, buf, u32, size, u64, flags)
1786 {
1787 static const u32 br_entry_size = sizeof(struct perf_branch_entry);
1788 struct perf_branch_stack *br_stack = ctx->data->br_stack;
1789 u32 to_copy;
1790
1791 if (unlikely(flags & ~BPF_F_GET_BRANCH_RECORDS_SIZE))
1792 return -EINVAL;
1793
1794 if (unlikely(!(ctx->data->sample_flags & PERF_SAMPLE_BRANCH_STACK)))
1795 return -ENOENT;
1796
1797 if (unlikely(!br_stack))
1798 return -ENOENT;
1799
1800 if (flags & BPF_F_GET_BRANCH_RECORDS_SIZE)
1801 return br_stack->nr * br_entry_size;
1802
1803 if (!buf || (size % br_entry_size != 0))
1804 return -EINVAL;
1805
1806 to_copy = min_t(u32, br_stack->nr * br_entry_size, size);
1807 memcpy(buf, br_stack->entries, to_copy);
1808
1809 return to_copy;
1810 }
1811
1812 static const struct bpf_func_proto bpf_read_branch_records_proto = {
1813 .func = bpf_read_branch_records,
1814 .gpl_only = true,
1815 .ret_type = RET_INTEGER,
1816 .arg1_type = ARG_PTR_TO_CTX,
1817 .arg2_type = ARG_PTR_TO_MEM_OR_NULL,
1818 .arg3_type = ARG_CONST_SIZE_OR_ZERO,
1819 .arg4_type = ARG_ANYTHING,
1820 };
1821
1822 static const struct bpf_func_proto *
pe_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1823 pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1824 {
1825 switch (func_id) {
1826 case BPF_FUNC_perf_event_output:
1827 return &bpf_perf_event_output_proto_tp;
1828 case BPF_FUNC_get_stackid:
1829 return &bpf_get_stackid_proto_pe;
1830 case BPF_FUNC_get_stack:
1831 return &bpf_get_stack_proto_pe;
1832 case BPF_FUNC_perf_prog_read_value:
1833 return &bpf_perf_prog_read_value_proto;
1834 case BPF_FUNC_read_branch_records:
1835 return &bpf_read_branch_records_proto;
1836 case BPF_FUNC_get_attach_cookie:
1837 return &bpf_get_attach_cookie_proto_pe;
1838 default:
1839 return bpf_tracing_func_proto(func_id, prog);
1840 }
1841 }
1842
1843 /*
1844 * bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp
1845 * to avoid potential recursive reuse issue when/if tracepoints are added
1846 * inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack.
1847 *
1848 * Since raw tracepoints run despite bpf_prog_active, support concurrent usage
1849 * in normal, irq, and nmi context.
1850 */
1851 struct bpf_raw_tp_regs {
1852 struct pt_regs regs[3];
1853 };
1854 static DEFINE_PER_CPU(struct bpf_raw_tp_regs, bpf_raw_tp_regs);
1855 static DEFINE_PER_CPU(int, bpf_raw_tp_nest_level);
get_bpf_raw_tp_regs(void)1856 static struct pt_regs *get_bpf_raw_tp_regs(void)
1857 {
1858 struct bpf_raw_tp_regs *tp_regs = this_cpu_ptr(&bpf_raw_tp_regs);
1859 int nest_level = this_cpu_inc_return(bpf_raw_tp_nest_level);
1860
1861 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(tp_regs->regs))) {
1862 this_cpu_dec(bpf_raw_tp_nest_level);
1863 return ERR_PTR(-EBUSY);
1864 }
1865
1866 return &tp_regs->regs[nest_level - 1];
1867 }
1868
put_bpf_raw_tp_regs(void)1869 static void put_bpf_raw_tp_regs(void)
1870 {
1871 this_cpu_dec(bpf_raw_tp_nest_level);
1872 }
1873
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)1874 BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args,
1875 struct bpf_map *, map, u64, flags, void *, data, u64, size)
1876 {
1877 struct pt_regs *regs = get_bpf_raw_tp_regs();
1878 int ret;
1879
1880 if (IS_ERR(regs))
1881 return PTR_ERR(regs);
1882
1883 perf_fetch_caller_regs(regs);
1884 ret = ____bpf_perf_event_output(regs, map, flags, data, size);
1885
1886 put_bpf_raw_tp_regs();
1887 return ret;
1888 }
1889
1890 static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = {
1891 .func = bpf_perf_event_output_raw_tp,
1892 .gpl_only = true,
1893 .ret_type = RET_INTEGER,
1894 .arg1_type = ARG_PTR_TO_CTX,
1895 .arg2_type = ARG_CONST_MAP_PTR,
1896 .arg3_type = ARG_ANYTHING,
1897 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY,
1898 .arg5_type = ARG_CONST_SIZE_OR_ZERO,
1899 };
1900
1901 extern const struct bpf_func_proto bpf_skb_output_proto;
1902 extern const struct bpf_func_proto bpf_xdp_output_proto;
1903 extern const struct bpf_func_proto bpf_xdp_get_buff_len_trace_proto;
1904
BPF_CALL_3(bpf_get_stackid_raw_tp,struct bpf_raw_tracepoint_args *,args,struct bpf_map *,map,u64,flags)1905 BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args,
1906 struct bpf_map *, map, u64, flags)
1907 {
1908 struct pt_regs *regs = get_bpf_raw_tp_regs();
1909 int ret;
1910
1911 if (IS_ERR(regs))
1912 return PTR_ERR(regs);
1913
1914 perf_fetch_caller_regs(regs);
1915 /* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */
1916 ret = bpf_get_stackid((unsigned long) regs, (unsigned long) map,
1917 flags, 0, 0);
1918 put_bpf_raw_tp_regs();
1919 return ret;
1920 }
1921
1922 static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = {
1923 .func = bpf_get_stackid_raw_tp,
1924 .gpl_only = true,
1925 .ret_type = RET_INTEGER,
1926 .arg1_type = ARG_PTR_TO_CTX,
1927 .arg2_type = ARG_CONST_MAP_PTR,
1928 .arg3_type = ARG_ANYTHING,
1929 };
1930
BPF_CALL_4(bpf_get_stack_raw_tp,struct bpf_raw_tracepoint_args *,args,void *,buf,u32,size,u64,flags)1931 BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args,
1932 void *, buf, u32, size, u64, flags)
1933 {
1934 struct pt_regs *regs = get_bpf_raw_tp_regs();
1935 int ret;
1936
1937 if (IS_ERR(regs))
1938 return PTR_ERR(regs);
1939
1940 perf_fetch_caller_regs(regs);
1941 ret = bpf_get_stack((unsigned long) regs, (unsigned long) buf,
1942 (unsigned long) size, flags, 0);
1943 put_bpf_raw_tp_regs();
1944 return ret;
1945 }
1946
1947 static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = {
1948 .func = bpf_get_stack_raw_tp,
1949 .gpl_only = true,
1950 .ret_type = RET_INTEGER,
1951 .arg1_type = ARG_PTR_TO_CTX,
1952 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
1953 .arg3_type = ARG_CONST_SIZE_OR_ZERO,
1954 .arg4_type = ARG_ANYTHING,
1955 };
1956
1957 static const struct bpf_func_proto *
raw_tp_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1958 raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1959 {
1960 switch (func_id) {
1961 case BPF_FUNC_perf_event_output:
1962 return &bpf_perf_event_output_proto_raw_tp;
1963 case BPF_FUNC_get_stackid:
1964 return &bpf_get_stackid_proto_raw_tp;
1965 case BPF_FUNC_get_stack:
1966 return &bpf_get_stack_proto_raw_tp;
1967 case BPF_FUNC_get_attach_cookie:
1968 return &bpf_get_attach_cookie_proto_tracing;
1969 default:
1970 return bpf_tracing_func_proto(func_id, prog);
1971 }
1972 }
1973
1974 const struct bpf_func_proto *
tracing_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1975 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1976 {
1977 const struct bpf_func_proto *fn;
1978
1979 switch (func_id) {
1980 #ifdef CONFIG_NET
1981 case BPF_FUNC_skb_output:
1982 return &bpf_skb_output_proto;
1983 case BPF_FUNC_xdp_output:
1984 return &bpf_xdp_output_proto;
1985 case BPF_FUNC_skc_to_tcp6_sock:
1986 return &bpf_skc_to_tcp6_sock_proto;
1987 case BPF_FUNC_skc_to_tcp_sock:
1988 return &bpf_skc_to_tcp_sock_proto;
1989 case BPF_FUNC_skc_to_tcp_timewait_sock:
1990 return &bpf_skc_to_tcp_timewait_sock_proto;
1991 case BPF_FUNC_skc_to_tcp_request_sock:
1992 return &bpf_skc_to_tcp_request_sock_proto;
1993 case BPF_FUNC_skc_to_udp6_sock:
1994 return &bpf_skc_to_udp6_sock_proto;
1995 case BPF_FUNC_skc_to_unix_sock:
1996 return &bpf_skc_to_unix_sock_proto;
1997 case BPF_FUNC_skc_to_mptcp_sock:
1998 return &bpf_skc_to_mptcp_sock_proto;
1999 case BPF_FUNC_sk_storage_get:
2000 return &bpf_sk_storage_get_tracing_proto;
2001 case BPF_FUNC_sk_storage_delete:
2002 return &bpf_sk_storage_delete_tracing_proto;
2003 case BPF_FUNC_sock_from_file:
2004 return &bpf_sock_from_file_proto;
2005 case BPF_FUNC_get_socket_cookie:
2006 return &bpf_get_socket_ptr_cookie_proto;
2007 case BPF_FUNC_xdp_get_buff_len:
2008 return &bpf_xdp_get_buff_len_trace_proto;
2009 #endif
2010 case BPF_FUNC_seq_printf:
2011 return prog->expected_attach_type == BPF_TRACE_ITER ?
2012 &bpf_seq_printf_proto :
2013 NULL;
2014 case BPF_FUNC_seq_write:
2015 return prog->expected_attach_type == BPF_TRACE_ITER ?
2016 &bpf_seq_write_proto :
2017 NULL;
2018 case BPF_FUNC_seq_printf_btf:
2019 return prog->expected_attach_type == BPF_TRACE_ITER ?
2020 &bpf_seq_printf_btf_proto :
2021 NULL;
2022 case BPF_FUNC_d_path:
2023 return &bpf_d_path_proto;
2024 case BPF_FUNC_get_func_arg:
2025 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_proto : NULL;
2026 case BPF_FUNC_get_func_ret:
2027 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_ret_proto : NULL;
2028 case BPF_FUNC_get_func_arg_cnt:
2029 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_cnt_proto : NULL;
2030 case BPF_FUNC_get_attach_cookie:
2031 if (prog->type == BPF_PROG_TYPE_TRACING &&
2032 prog->expected_attach_type == BPF_TRACE_RAW_TP)
2033 return &bpf_get_attach_cookie_proto_tracing;
2034 return bpf_prog_has_trampoline(prog) ? &bpf_get_attach_cookie_proto_tracing : NULL;
2035 default:
2036 fn = raw_tp_prog_func_proto(func_id, prog);
2037 if (!fn && prog->expected_attach_type == BPF_TRACE_ITER)
2038 fn = bpf_iter_get_func_proto(func_id, prog);
2039 return fn;
2040 }
2041 }
2042
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)2043 static bool raw_tp_prog_is_valid_access(int off, int size,
2044 enum bpf_access_type type,
2045 const struct bpf_prog *prog,
2046 struct bpf_insn_access_aux *info)
2047 {
2048 return bpf_tracing_ctx_access(off, size, type);
2049 }
2050
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)2051 static bool tracing_prog_is_valid_access(int off, int size,
2052 enum bpf_access_type type,
2053 const struct bpf_prog *prog,
2054 struct bpf_insn_access_aux *info)
2055 {
2056 return bpf_tracing_btf_ctx_access(off, size, type, prog, info);
2057 }
2058
bpf_prog_test_run_tracing(struct bpf_prog * prog,const union bpf_attr * kattr,union bpf_attr __user * uattr)2059 int __weak bpf_prog_test_run_tracing(struct bpf_prog *prog,
2060 const union bpf_attr *kattr,
2061 union bpf_attr __user *uattr)
2062 {
2063 return -ENOTSUPP;
2064 }
2065
2066 const struct bpf_verifier_ops raw_tracepoint_verifier_ops = {
2067 .get_func_proto = raw_tp_prog_func_proto,
2068 .is_valid_access = raw_tp_prog_is_valid_access,
2069 };
2070
2071 const struct bpf_prog_ops raw_tracepoint_prog_ops = {
2072 #ifdef CONFIG_NET
2073 .test_run = bpf_prog_test_run_raw_tp,
2074 #endif
2075 };
2076
2077 const struct bpf_verifier_ops tracing_verifier_ops = {
2078 .get_func_proto = tracing_prog_func_proto,
2079 .is_valid_access = tracing_prog_is_valid_access,
2080 };
2081
2082 const struct bpf_prog_ops tracing_prog_ops = {
2083 .test_run = bpf_prog_test_run_tracing,
2084 };
2085
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)2086 static bool raw_tp_writable_prog_is_valid_access(int off, int size,
2087 enum bpf_access_type type,
2088 const struct bpf_prog *prog,
2089 struct bpf_insn_access_aux *info)
2090 {
2091 if (off == 0) {
2092 if (size != sizeof(u64) || type != BPF_READ)
2093 return false;
2094 info->reg_type = PTR_TO_TP_BUFFER;
2095 }
2096 return raw_tp_prog_is_valid_access(off, size, type, prog, info);
2097 }
2098
2099 const struct bpf_verifier_ops raw_tracepoint_writable_verifier_ops = {
2100 .get_func_proto = raw_tp_prog_func_proto,
2101 .is_valid_access = raw_tp_writable_prog_is_valid_access,
2102 };
2103
2104 const struct bpf_prog_ops raw_tracepoint_writable_prog_ops = {
2105 };
2106
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)2107 static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
2108 const struct bpf_prog *prog,
2109 struct bpf_insn_access_aux *info)
2110 {
2111 const int size_u64 = sizeof(u64);
2112
2113 if (off < 0 || off >= sizeof(struct bpf_perf_event_data))
2114 return false;
2115 if (type != BPF_READ)
2116 return false;
2117 if (off % size != 0) {
2118 if (sizeof(unsigned long) != 4)
2119 return false;
2120 if (size != 8)
2121 return false;
2122 if (off % size != 4)
2123 return false;
2124 }
2125
2126 switch (off) {
2127 case bpf_ctx_range(struct bpf_perf_event_data, sample_period):
2128 bpf_ctx_record_field_size(info, size_u64);
2129 if (!bpf_ctx_narrow_access_ok(off, size, size_u64))
2130 return false;
2131 break;
2132 case bpf_ctx_range(struct bpf_perf_event_data, addr):
2133 bpf_ctx_record_field_size(info, size_u64);
2134 if (!bpf_ctx_narrow_access_ok(off, size, size_u64))
2135 return false;
2136 break;
2137 default:
2138 if (size != sizeof(long))
2139 return false;
2140 }
2141
2142 return true;
2143 }
2144
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)2145 static u32 pe_prog_convert_ctx_access(enum bpf_access_type type,
2146 const struct bpf_insn *si,
2147 struct bpf_insn *insn_buf,
2148 struct bpf_prog *prog, u32 *target_size)
2149 {
2150 struct bpf_insn *insn = insn_buf;
2151
2152 switch (si->off) {
2153 case offsetof(struct bpf_perf_event_data, sample_period):
2154 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
2155 data), si->dst_reg, si->src_reg,
2156 offsetof(struct bpf_perf_event_data_kern, data));
2157 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg,
2158 bpf_target_off(struct perf_sample_data, period, 8,
2159 target_size));
2160 break;
2161 case offsetof(struct bpf_perf_event_data, addr):
2162 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
2163 data), si->dst_reg, si->src_reg,
2164 offsetof(struct bpf_perf_event_data_kern, data));
2165 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg,
2166 bpf_target_off(struct perf_sample_data, addr, 8,
2167 target_size));
2168 break;
2169 default:
2170 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
2171 regs), si->dst_reg, si->src_reg,
2172 offsetof(struct bpf_perf_event_data_kern, regs));
2173 *insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg,
2174 si->off);
2175 break;
2176 }
2177
2178 return insn - insn_buf;
2179 }
2180
2181 const struct bpf_verifier_ops perf_event_verifier_ops = {
2182 .get_func_proto = pe_prog_func_proto,
2183 .is_valid_access = pe_prog_is_valid_access,
2184 .convert_ctx_access = pe_prog_convert_ctx_access,
2185 };
2186
2187 const struct bpf_prog_ops perf_event_prog_ops = {
2188 };
2189
2190 static DEFINE_MUTEX(bpf_event_mutex);
2191
2192 #define BPF_TRACE_MAX_PROGS 64
2193
perf_event_attach_bpf_prog(struct perf_event * event,struct bpf_prog * prog,u64 bpf_cookie)2194 int perf_event_attach_bpf_prog(struct perf_event *event,
2195 struct bpf_prog *prog,
2196 u64 bpf_cookie)
2197 {
2198 struct bpf_prog_array *old_array;
2199 struct bpf_prog_array *new_array;
2200 int ret = -EEXIST;
2201
2202 /*
2203 * Kprobe override only works if they are on the function entry,
2204 * and only if they are on the opt-in list.
2205 */
2206 if (prog->kprobe_override &&
2207 (!trace_kprobe_on_func_entry(event->tp_event) ||
2208 !trace_kprobe_error_injectable(event->tp_event)))
2209 return -EINVAL;
2210
2211 mutex_lock(&bpf_event_mutex);
2212
2213 if (event->prog)
2214 goto unlock;
2215
2216 old_array = bpf_event_rcu_dereference(event->tp_event->prog_array);
2217 if (old_array &&
2218 bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) {
2219 ret = -E2BIG;
2220 goto unlock;
2221 }
2222
2223 ret = bpf_prog_array_copy(old_array, NULL, prog, bpf_cookie, &new_array);
2224 if (ret < 0)
2225 goto unlock;
2226
2227 /* set the new array to event->tp_event and set event->prog */
2228 event->prog = prog;
2229 event->bpf_cookie = bpf_cookie;
2230 rcu_assign_pointer(event->tp_event->prog_array, new_array);
2231 bpf_prog_array_free_sleepable(old_array);
2232
2233 unlock:
2234 mutex_unlock(&bpf_event_mutex);
2235 return ret;
2236 }
2237
perf_event_detach_bpf_prog(struct perf_event * event)2238 void perf_event_detach_bpf_prog(struct perf_event *event)
2239 {
2240 struct bpf_prog_array *old_array;
2241 struct bpf_prog_array *new_array;
2242 struct bpf_prog *prog = NULL;
2243 int ret;
2244
2245 mutex_lock(&bpf_event_mutex);
2246
2247 if (!event->prog)
2248 goto unlock;
2249
2250 old_array = bpf_event_rcu_dereference(event->tp_event->prog_array);
2251 if (!old_array)
2252 goto put;
2253
2254 ret = bpf_prog_array_copy(old_array, event->prog, NULL, 0, &new_array);
2255 if (ret < 0) {
2256 bpf_prog_array_delete_safe(old_array, event->prog);
2257 } else {
2258 rcu_assign_pointer(event->tp_event->prog_array, new_array);
2259 bpf_prog_array_free_sleepable(old_array);
2260 }
2261
2262 put:
2263 prog = event->prog;
2264 event->prog = NULL;
2265
2266 unlock:
2267 mutex_unlock(&bpf_event_mutex);
2268
2269 if (prog) {
2270 /*
2271 * It could be that the bpf_prog is not sleepable (and will be freed
2272 * via normal RCU), but is called from a point that supports sleepable
2273 * programs and uses tasks-trace-RCU.
2274 */
2275 synchronize_rcu_tasks_trace();
2276
2277 bpf_prog_put(prog);
2278 }
2279 }
2280
perf_event_query_prog_array(struct perf_event * event,void __user * info)2281 int perf_event_query_prog_array(struct perf_event *event, void __user *info)
2282 {
2283 struct perf_event_query_bpf __user *uquery = info;
2284 struct perf_event_query_bpf query = {};
2285 struct bpf_prog_array *progs;
2286 u32 *ids, prog_cnt, ids_len;
2287 int ret;
2288
2289 if (!perfmon_capable())
2290 return -EPERM;
2291 if (event->attr.type != PERF_TYPE_TRACEPOINT)
2292 return -EINVAL;
2293 if (copy_from_user(&query, uquery, sizeof(query)))
2294 return -EFAULT;
2295
2296 ids_len = query.ids_len;
2297 if (ids_len > BPF_TRACE_MAX_PROGS)
2298 return -E2BIG;
2299 ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN);
2300 if (!ids)
2301 return -ENOMEM;
2302 /*
2303 * The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which
2304 * is required when user only wants to check for uquery->prog_cnt.
2305 * There is no need to check for it since the case is handled
2306 * gracefully in bpf_prog_array_copy_info.
2307 */
2308
2309 mutex_lock(&bpf_event_mutex);
2310 progs = bpf_event_rcu_dereference(event->tp_event->prog_array);
2311 ret = bpf_prog_array_copy_info(progs, ids, ids_len, &prog_cnt);
2312 mutex_unlock(&bpf_event_mutex);
2313
2314 if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) ||
2315 copy_to_user(uquery->ids, ids, ids_len * sizeof(u32)))
2316 ret = -EFAULT;
2317
2318 kfree(ids);
2319 return ret;
2320 }
2321
2322 extern struct bpf_raw_event_map __start__bpf_raw_tp[];
2323 extern struct bpf_raw_event_map __stop__bpf_raw_tp[];
2324
bpf_get_raw_tracepoint(const char * name)2325 struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name)
2326 {
2327 struct bpf_raw_event_map *btp = __start__bpf_raw_tp;
2328
2329 for (; btp < __stop__bpf_raw_tp; btp++) {
2330 if (!strcmp(btp->tp->name, name))
2331 return btp;
2332 }
2333
2334 return bpf_get_raw_tracepoint_module(name);
2335 }
2336
bpf_put_raw_tracepoint(struct bpf_raw_event_map * btp)2337 void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp)
2338 {
2339 struct module *mod;
2340
2341 guard(rcu)();
2342 mod = __module_address((unsigned long)btp);
2343 module_put(mod);
2344 }
2345
2346 static __always_inline
__bpf_trace_run(struct bpf_raw_tp_link * link,u64 * args)2347 void __bpf_trace_run(struct bpf_raw_tp_link *link, u64 *args)
2348 {
2349 struct bpf_prog *prog = link->link.prog;
2350 struct bpf_run_ctx *old_run_ctx;
2351 struct bpf_trace_run_ctx run_ctx;
2352
2353 cant_sleep();
2354 if (unlikely(this_cpu_inc_return(*(prog->active)) != 1)) {
2355 bpf_prog_inc_misses_counter(prog);
2356 goto out;
2357 }
2358
2359 run_ctx.bpf_cookie = link->cookie;
2360 old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx);
2361
2362 rcu_read_lock();
2363 (void) bpf_prog_run(prog, args);
2364 rcu_read_unlock();
2365
2366 bpf_reset_run_ctx(old_run_ctx);
2367 out:
2368 this_cpu_dec(*(prog->active));
2369 }
2370
2371 #define UNPACK(...) __VA_ARGS__
2372 #define REPEAT_1(FN, DL, X, ...) FN(X)
2373 #define REPEAT_2(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__)
2374 #define REPEAT_3(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_2(FN, DL, __VA_ARGS__)
2375 #define REPEAT_4(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_3(FN, DL, __VA_ARGS__)
2376 #define REPEAT_5(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_4(FN, DL, __VA_ARGS__)
2377 #define REPEAT_6(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_5(FN, DL, __VA_ARGS__)
2378 #define REPEAT_7(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_6(FN, DL, __VA_ARGS__)
2379 #define REPEAT_8(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_7(FN, DL, __VA_ARGS__)
2380 #define REPEAT_9(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_8(FN, DL, __VA_ARGS__)
2381 #define REPEAT_10(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_9(FN, DL, __VA_ARGS__)
2382 #define REPEAT_11(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_10(FN, DL, __VA_ARGS__)
2383 #define REPEAT_12(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_11(FN, DL, __VA_ARGS__)
2384 #define REPEAT(X, FN, DL, ...) REPEAT_##X(FN, DL, __VA_ARGS__)
2385
2386 #define SARG(X) u64 arg##X
2387 #define COPY(X) args[X] = arg##X
2388
2389 #define __DL_COM (,)
2390 #define __DL_SEM (;)
2391
2392 #define __SEQ_0_11 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11
2393
2394 #define BPF_TRACE_DEFN_x(x) \
2395 void bpf_trace_run##x(struct bpf_raw_tp_link *link, \
2396 REPEAT(x, SARG, __DL_COM, __SEQ_0_11)) \
2397 { \
2398 u64 args[x]; \
2399 REPEAT(x, COPY, __DL_SEM, __SEQ_0_11); \
2400 __bpf_trace_run(link, args); \
2401 } \
2402 EXPORT_SYMBOL_GPL(bpf_trace_run##x)
2403 BPF_TRACE_DEFN_x(1);
2404 BPF_TRACE_DEFN_x(2);
2405 BPF_TRACE_DEFN_x(3);
2406 BPF_TRACE_DEFN_x(4);
2407 BPF_TRACE_DEFN_x(5);
2408 BPF_TRACE_DEFN_x(6);
2409 BPF_TRACE_DEFN_x(7);
2410 BPF_TRACE_DEFN_x(8);
2411 BPF_TRACE_DEFN_x(9);
2412 BPF_TRACE_DEFN_x(10);
2413 BPF_TRACE_DEFN_x(11);
2414 BPF_TRACE_DEFN_x(12);
2415
bpf_probe_register(struct bpf_raw_event_map * btp,struct bpf_raw_tp_link * link)2416 int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_raw_tp_link *link)
2417 {
2418 struct tracepoint *tp = btp->tp;
2419 struct bpf_prog *prog = link->link.prog;
2420
2421 /*
2422 * check that program doesn't access arguments beyond what's
2423 * available in this tracepoint
2424 */
2425 if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64))
2426 return -EINVAL;
2427
2428 if (prog->aux->max_tp_access > btp->writable_size)
2429 return -EINVAL;
2430
2431 return tracepoint_probe_register_may_exist(tp, (void *)btp->bpf_func, link);
2432 }
2433
bpf_probe_unregister(struct bpf_raw_event_map * btp,struct bpf_raw_tp_link * link)2434 int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_raw_tp_link *link)
2435 {
2436 return tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, link);
2437 }
2438
bpf_get_perf_event_info(const struct perf_event * event,u32 * prog_id,u32 * fd_type,const char ** buf,u64 * probe_offset,u64 * probe_addr,unsigned long * missed)2439 int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id,
2440 u32 *fd_type, const char **buf,
2441 u64 *probe_offset, u64 *probe_addr,
2442 unsigned long *missed)
2443 {
2444 bool is_tracepoint, is_syscall_tp;
2445 struct bpf_prog *prog;
2446 int flags, err = 0;
2447
2448 prog = event->prog;
2449 if (!prog)
2450 return -ENOENT;
2451
2452 /* not supporting BPF_PROG_TYPE_PERF_EVENT yet */
2453 if (prog->type == BPF_PROG_TYPE_PERF_EVENT)
2454 return -EOPNOTSUPP;
2455
2456 *prog_id = prog->aux->id;
2457 flags = event->tp_event->flags;
2458 is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT;
2459 is_syscall_tp = is_syscall_trace_event(event->tp_event);
2460
2461 if (is_tracepoint || is_syscall_tp) {
2462 *buf = is_tracepoint ? event->tp_event->tp->name
2463 : event->tp_event->name;
2464 /* We allow NULL pointer for tracepoint */
2465 if (fd_type)
2466 *fd_type = BPF_FD_TYPE_TRACEPOINT;
2467 if (probe_offset)
2468 *probe_offset = 0x0;
2469 if (probe_addr)
2470 *probe_addr = 0x0;
2471 } else {
2472 /* kprobe/uprobe */
2473 err = -EOPNOTSUPP;
2474 #ifdef CONFIG_KPROBE_EVENTS
2475 if (flags & TRACE_EVENT_FL_KPROBE)
2476 err = bpf_get_kprobe_info(event, fd_type, buf,
2477 probe_offset, probe_addr, missed,
2478 event->attr.type == PERF_TYPE_TRACEPOINT);
2479 #endif
2480 #ifdef CONFIG_UPROBE_EVENTS
2481 if (flags & TRACE_EVENT_FL_UPROBE)
2482 err = bpf_get_uprobe_info(event, fd_type, buf,
2483 probe_offset, probe_addr,
2484 event->attr.type == PERF_TYPE_TRACEPOINT);
2485 #endif
2486 }
2487
2488 return err;
2489 }
2490
send_signal_irq_work_init(void)2491 static int __init send_signal_irq_work_init(void)
2492 {
2493 int cpu;
2494 struct send_signal_irq_work *work;
2495
2496 for_each_possible_cpu(cpu) {
2497 work = per_cpu_ptr(&send_signal_work, cpu);
2498 init_irq_work(&work->irq_work, do_bpf_send_signal);
2499 }
2500 return 0;
2501 }
2502
2503 subsys_initcall(send_signal_irq_work_init);
2504
2505 #ifdef CONFIG_MODULES
bpf_event_notify(struct notifier_block * nb,unsigned long op,void * module)2506 static int bpf_event_notify(struct notifier_block *nb, unsigned long op,
2507 void *module)
2508 {
2509 struct bpf_trace_module *btm, *tmp;
2510 struct module *mod = module;
2511 int ret = 0;
2512
2513 if (mod->num_bpf_raw_events == 0 ||
2514 (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING))
2515 goto out;
2516
2517 mutex_lock(&bpf_module_mutex);
2518
2519 switch (op) {
2520 case MODULE_STATE_COMING:
2521 btm = kzalloc(sizeof(*btm), GFP_KERNEL);
2522 if (btm) {
2523 btm->module = module;
2524 list_add(&btm->list, &bpf_trace_modules);
2525 } else {
2526 ret = -ENOMEM;
2527 }
2528 break;
2529 case MODULE_STATE_GOING:
2530 list_for_each_entry_safe(btm, tmp, &bpf_trace_modules, list) {
2531 if (btm->module == module) {
2532 list_del(&btm->list);
2533 kfree(btm);
2534 break;
2535 }
2536 }
2537 break;
2538 }
2539
2540 mutex_unlock(&bpf_module_mutex);
2541
2542 out:
2543 return notifier_from_errno(ret);
2544 }
2545
2546 static struct notifier_block bpf_module_nb = {
2547 .notifier_call = bpf_event_notify,
2548 };
2549
bpf_event_init(void)2550 static int __init bpf_event_init(void)
2551 {
2552 register_module_notifier(&bpf_module_nb);
2553 return 0;
2554 }
2555
2556 fs_initcall(bpf_event_init);
2557 #endif /* CONFIG_MODULES */
2558
2559 struct bpf_session_run_ctx {
2560 struct bpf_run_ctx run_ctx;
2561 bool is_return;
2562 void *data;
2563 };
2564
2565 #ifdef CONFIG_FPROBE
2566 struct bpf_kprobe_multi_link {
2567 struct bpf_link link;
2568 struct fprobe fp;
2569 unsigned long *addrs;
2570 u64 *cookies;
2571 u32 cnt;
2572 u32 mods_cnt;
2573 struct module **mods;
2574 u32 flags;
2575 };
2576
2577 struct bpf_kprobe_multi_run_ctx {
2578 struct bpf_session_run_ctx session_ctx;
2579 struct bpf_kprobe_multi_link *link;
2580 unsigned long entry_ip;
2581 };
2582
2583 struct user_syms {
2584 const char **syms;
2585 char *buf;
2586 };
2587
2588 #ifndef CONFIG_HAVE_FTRACE_REGS_HAVING_PT_REGS
2589 static DEFINE_PER_CPU(struct pt_regs, bpf_kprobe_multi_pt_regs);
2590 #define bpf_kprobe_multi_pt_regs_ptr() this_cpu_ptr(&bpf_kprobe_multi_pt_regs)
2591 #else
2592 #define bpf_kprobe_multi_pt_regs_ptr() (NULL)
2593 #endif
2594
ftrace_get_entry_ip(unsigned long fentry_ip)2595 static unsigned long ftrace_get_entry_ip(unsigned long fentry_ip)
2596 {
2597 unsigned long ip = ftrace_get_symaddr(fentry_ip);
2598
2599 return ip ? : fentry_ip;
2600 }
2601
copy_user_syms(struct user_syms * us,unsigned long __user * usyms,u32 cnt)2602 static int copy_user_syms(struct user_syms *us, unsigned long __user *usyms, u32 cnt)
2603 {
2604 unsigned long __user usymbol;
2605 const char **syms = NULL;
2606 char *buf = NULL, *p;
2607 int err = -ENOMEM;
2608 unsigned int i;
2609
2610 syms = kvmalloc_array(cnt, sizeof(*syms), GFP_KERNEL);
2611 if (!syms)
2612 goto error;
2613
2614 buf = kvmalloc_array(cnt, KSYM_NAME_LEN, GFP_KERNEL);
2615 if (!buf)
2616 goto error;
2617
2618 for (p = buf, i = 0; i < cnt; i++) {
2619 if (__get_user(usymbol, usyms + i)) {
2620 err = -EFAULT;
2621 goto error;
2622 }
2623 err = strncpy_from_user(p, (const char __user *) usymbol, KSYM_NAME_LEN);
2624 if (err == KSYM_NAME_LEN)
2625 err = -E2BIG;
2626 if (err < 0)
2627 goto error;
2628 syms[i] = p;
2629 p += err + 1;
2630 }
2631
2632 us->syms = syms;
2633 us->buf = buf;
2634 return 0;
2635
2636 error:
2637 if (err) {
2638 kvfree(syms);
2639 kvfree(buf);
2640 }
2641 return err;
2642 }
2643
kprobe_multi_put_modules(struct module ** mods,u32 cnt)2644 static void kprobe_multi_put_modules(struct module **mods, u32 cnt)
2645 {
2646 u32 i;
2647
2648 for (i = 0; i < cnt; i++)
2649 module_put(mods[i]);
2650 }
2651
free_user_syms(struct user_syms * us)2652 static void free_user_syms(struct user_syms *us)
2653 {
2654 kvfree(us->syms);
2655 kvfree(us->buf);
2656 }
2657
bpf_kprobe_multi_link_release(struct bpf_link * link)2658 static void bpf_kprobe_multi_link_release(struct bpf_link *link)
2659 {
2660 struct bpf_kprobe_multi_link *kmulti_link;
2661
2662 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);
2663 unregister_fprobe(&kmulti_link->fp);
2664 kprobe_multi_put_modules(kmulti_link->mods, kmulti_link->mods_cnt);
2665 }
2666
bpf_kprobe_multi_link_dealloc(struct bpf_link * link)2667 static void bpf_kprobe_multi_link_dealloc(struct bpf_link *link)
2668 {
2669 struct bpf_kprobe_multi_link *kmulti_link;
2670
2671 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);
2672 kvfree(kmulti_link->addrs);
2673 kvfree(kmulti_link->cookies);
2674 kfree(kmulti_link->mods);
2675 kfree(kmulti_link);
2676 }
2677
bpf_kprobe_multi_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)2678 static int bpf_kprobe_multi_link_fill_link_info(const struct bpf_link *link,
2679 struct bpf_link_info *info)
2680 {
2681 u64 __user *ucookies = u64_to_user_ptr(info->kprobe_multi.cookies);
2682 u64 __user *uaddrs = u64_to_user_ptr(info->kprobe_multi.addrs);
2683 struct bpf_kprobe_multi_link *kmulti_link;
2684 u32 ucount = info->kprobe_multi.count;
2685 int err = 0, i;
2686
2687 if (!uaddrs ^ !ucount)
2688 return -EINVAL;
2689 if (ucookies && !ucount)
2690 return -EINVAL;
2691
2692 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);
2693 info->kprobe_multi.count = kmulti_link->cnt;
2694 info->kprobe_multi.flags = kmulti_link->flags;
2695 info->kprobe_multi.missed = kmulti_link->fp.nmissed;
2696
2697 if (!uaddrs)
2698 return 0;
2699 if (ucount < kmulti_link->cnt)
2700 err = -ENOSPC;
2701 else
2702 ucount = kmulti_link->cnt;
2703
2704 if (ucookies) {
2705 if (kmulti_link->cookies) {
2706 if (copy_to_user(ucookies, kmulti_link->cookies, ucount * sizeof(u64)))
2707 return -EFAULT;
2708 } else {
2709 for (i = 0; i < ucount; i++) {
2710 if (put_user(0, ucookies + i))
2711 return -EFAULT;
2712 }
2713 }
2714 }
2715
2716 if (kallsyms_show_value(current_cred())) {
2717 if (copy_to_user(uaddrs, kmulti_link->addrs, ucount * sizeof(u64)))
2718 return -EFAULT;
2719 } else {
2720 for (i = 0; i < ucount; i++) {
2721 if (put_user(0, uaddrs + i))
2722 return -EFAULT;
2723 }
2724 }
2725 return err;
2726 }
2727
2728 static const struct bpf_link_ops bpf_kprobe_multi_link_lops = {
2729 .release = bpf_kprobe_multi_link_release,
2730 .dealloc_deferred = bpf_kprobe_multi_link_dealloc,
2731 .fill_link_info = bpf_kprobe_multi_link_fill_link_info,
2732 };
2733
bpf_kprobe_multi_cookie_swap(void * a,void * b,int size,const void * priv)2734 static void bpf_kprobe_multi_cookie_swap(void *a, void *b, int size, const void *priv)
2735 {
2736 const struct bpf_kprobe_multi_link *link = priv;
2737 unsigned long *addr_a = a, *addr_b = b;
2738 u64 *cookie_a, *cookie_b;
2739
2740 cookie_a = link->cookies + (addr_a - link->addrs);
2741 cookie_b = link->cookies + (addr_b - link->addrs);
2742
2743 /* swap addr_a/addr_b and cookie_a/cookie_b values */
2744 swap(*addr_a, *addr_b);
2745 swap(*cookie_a, *cookie_b);
2746 }
2747
bpf_kprobe_multi_addrs_cmp(const void * a,const void * b)2748 static int bpf_kprobe_multi_addrs_cmp(const void *a, const void *b)
2749 {
2750 const unsigned long *addr_a = a, *addr_b = b;
2751
2752 if (*addr_a == *addr_b)
2753 return 0;
2754 return *addr_a < *addr_b ? -1 : 1;
2755 }
2756
bpf_kprobe_multi_cookie_cmp(const void * a,const void * b,const void * priv)2757 static int bpf_kprobe_multi_cookie_cmp(const void *a, const void *b, const void *priv)
2758 {
2759 return bpf_kprobe_multi_addrs_cmp(a, b);
2760 }
2761
bpf_kprobe_multi_cookie(struct bpf_run_ctx * ctx)2762 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx)
2763 {
2764 struct bpf_kprobe_multi_run_ctx *run_ctx;
2765 struct bpf_kprobe_multi_link *link;
2766 u64 *cookie, entry_ip;
2767 unsigned long *addr;
2768
2769 if (WARN_ON_ONCE(!ctx))
2770 return 0;
2771 run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx,
2772 session_ctx.run_ctx);
2773 link = run_ctx->link;
2774 if (!link->cookies)
2775 return 0;
2776 entry_ip = run_ctx->entry_ip;
2777 addr = bsearch(&entry_ip, link->addrs, link->cnt, sizeof(entry_ip),
2778 bpf_kprobe_multi_addrs_cmp);
2779 if (!addr)
2780 return 0;
2781 cookie = link->cookies + (addr - link->addrs);
2782 return *cookie;
2783 }
2784
bpf_kprobe_multi_entry_ip(struct bpf_run_ctx * ctx)2785 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
2786 {
2787 struct bpf_kprobe_multi_run_ctx *run_ctx;
2788
2789 run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx,
2790 session_ctx.run_ctx);
2791 return run_ctx->entry_ip;
2792 }
2793
2794 static int
kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link * link,unsigned long entry_ip,struct ftrace_regs * fregs,bool is_return,void * data)2795 kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link,
2796 unsigned long entry_ip, struct ftrace_regs *fregs,
2797 bool is_return, void *data)
2798 {
2799 struct bpf_kprobe_multi_run_ctx run_ctx = {
2800 .session_ctx = {
2801 .is_return = is_return,
2802 .data = data,
2803 },
2804 .link = link,
2805 .entry_ip = entry_ip,
2806 };
2807 struct bpf_run_ctx *old_run_ctx;
2808 struct pt_regs *regs;
2809 int err;
2810
2811 if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) {
2812 bpf_prog_inc_misses_counter(link->link.prog);
2813 err = 1;
2814 goto out;
2815 }
2816
2817 migrate_disable();
2818 rcu_read_lock();
2819 regs = ftrace_partial_regs(fregs, bpf_kprobe_multi_pt_regs_ptr());
2820 old_run_ctx = bpf_set_run_ctx(&run_ctx.session_ctx.run_ctx);
2821 err = bpf_prog_run(link->link.prog, regs);
2822 bpf_reset_run_ctx(old_run_ctx);
2823 rcu_read_unlock();
2824 migrate_enable();
2825
2826 out:
2827 __this_cpu_dec(bpf_prog_active);
2828 return err;
2829 }
2830
2831 static int
kprobe_multi_link_handler(struct fprobe * fp,unsigned long fentry_ip,unsigned long ret_ip,struct ftrace_regs * fregs,void * data)2832 kprobe_multi_link_handler(struct fprobe *fp, unsigned long fentry_ip,
2833 unsigned long ret_ip, struct ftrace_regs *fregs,
2834 void *data)
2835 {
2836 struct bpf_kprobe_multi_link *link;
2837 int err;
2838
2839 link = container_of(fp, struct bpf_kprobe_multi_link, fp);
2840 err = kprobe_multi_link_prog_run(link, ftrace_get_entry_ip(fentry_ip),
2841 fregs, false, data);
2842 return is_kprobe_session(link->link.prog) ? err : 0;
2843 }
2844
2845 static void
kprobe_multi_link_exit_handler(struct fprobe * fp,unsigned long fentry_ip,unsigned long ret_ip,struct ftrace_regs * fregs,void * data)2846 kprobe_multi_link_exit_handler(struct fprobe *fp, unsigned long fentry_ip,
2847 unsigned long ret_ip, struct ftrace_regs *fregs,
2848 void *data)
2849 {
2850 struct bpf_kprobe_multi_link *link;
2851
2852 link = container_of(fp, struct bpf_kprobe_multi_link, fp);
2853 kprobe_multi_link_prog_run(link, ftrace_get_entry_ip(fentry_ip),
2854 fregs, true, data);
2855 }
2856
symbols_cmp_r(const void * a,const void * b,const void * priv)2857 static int symbols_cmp_r(const void *a, const void *b, const void *priv)
2858 {
2859 const char **str_a = (const char **) a;
2860 const char **str_b = (const char **) b;
2861
2862 return strcmp(*str_a, *str_b);
2863 }
2864
2865 struct multi_symbols_sort {
2866 const char **funcs;
2867 u64 *cookies;
2868 };
2869
symbols_swap_r(void * a,void * b,int size,const void * priv)2870 static void symbols_swap_r(void *a, void *b, int size, const void *priv)
2871 {
2872 const struct multi_symbols_sort *data = priv;
2873 const char **name_a = a, **name_b = b;
2874
2875 swap(*name_a, *name_b);
2876
2877 /* If defined, swap also related cookies. */
2878 if (data->cookies) {
2879 u64 *cookie_a, *cookie_b;
2880
2881 cookie_a = data->cookies + (name_a - data->funcs);
2882 cookie_b = data->cookies + (name_b - data->funcs);
2883 swap(*cookie_a, *cookie_b);
2884 }
2885 }
2886
2887 struct modules_array {
2888 struct module **mods;
2889 int mods_cnt;
2890 int mods_cap;
2891 };
2892
add_module(struct modules_array * arr,struct module * mod)2893 static int add_module(struct modules_array *arr, struct module *mod)
2894 {
2895 struct module **mods;
2896
2897 if (arr->mods_cnt == arr->mods_cap) {
2898 arr->mods_cap = max(16, arr->mods_cap * 3 / 2);
2899 mods = krealloc_array(arr->mods, arr->mods_cap, sizeof(*mods), GFP_KERNEL);
2900 if (!mods)
2901 return -ENOMEM;
2902 arr->mods = mods;
2903 }
2904
2905 arr->mods[arr->mods_cnt] = mod;
2906 arr->mods_cnt++;
2907 return 0;
2908 }
2909
has_module(struct modules_array * arr,struct module * mod)2910 static bool has_module(struct modules_array *arr, struct module *mod)
2911 {
2912 int i;
2913
2914 for (i = arr->mods_cnt - 1; i >= 0; i--) {
2915 if (arr->mods[i] == mod)
2916 return true;
2917 }
2918 return false;
2919 }
2920
get_modules_for_addrs(struct module *** mods,unsigned long * addrs,u32 addrs_cnt)2921 static int get_modules_for_addrs(struct module ***mods, unsigned long *addrs, u32 addrs_cnt)
2922 {
2923 struct modules_array arr = {};
2924 u32 i, err = 0;
2925
2926 for (i = 0; i < addrs_cnt; i++) {
2927 bool skip_add = false;
2928 struct module *mod;
2929
2930 scoped_guard(rcu) {
2931 mod = __module_address(addrs[i]);
2932 /* Either no module or it's already stored */
2933 if (!mod || has_module(&arr, mod)) {
2934 skip_add = true;
2935 break; /* scoped_guard */
2936 }
2937 if (!try_module_get(mod))
2938 err = -EINVAL;
2939 }
2940 if (skip_add)
2941 continue;
2942 if (err)
2943 break;
2944 err = add_module(&arr, mod);
2945 if (err) {
2946 module_put(mod);
2947 break;
2948 }
2949 }
2950
2951 /* We return either err < 0 in case of error, ... */
2952 if (err) {
2953 kprobe_multi_put_modules(arr.mods, arr.mods_cnt);
2954 kfree(arr.mods);
2955 return err;
2956 }
2957
2958 /* or number of modules found if everything is ok. */
2959 *mods = arr.mods;
2960 return arr.mods_cnt;
2961 }
2962
addrs_check_error_injection_list(unsigned long * addrs,u32 cnt)2963 static int addrs_check_error_injection_list(unsigned long *addrs, u32 cnt)
2964 {
2965 u32 i;
2966
2967 for (i = 0; i < cnt; i++) {
2968 if (!within_error_injection_list(addrs[i]))
2969 return -EINVAL;
2970 }
2971 return 0;
2972 }
2973
bpf_kprobe_multi_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)2974 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
2975 {
2976 struct bpf_kprobe_multi_link *link = NULL;
2977 struct bpf_link_primer link_primer;
2978 void __user *ucookies;
2979 unsigned long *addrs;
2980 u32 flags, cnt, size;
2981 void __user *uaddrs;
2982 u64 *cookies = NULL;
2983 void __user *usyms;
2984 int err;
2985
2986 /* no support for 32bit archs yet */
2987 if (sizeof(u64) != sizeof(void *))
2988 return -EOPNOTSUPP;
2989
2990 if (!is_kprobe_multi(prog))
2991 return -EINVAL;
2992
2993 flags = attr->link_create.kprobe_multi.flags;
2994 if (flags & ~BPF_F_KPROBE_MULTI_RETURN)
2995 return -EINVAL;
2996
2997 uaddrs = u64_to_user_ptr(attr->link_create.kprobe_multi.addrs);
2998 usyms = u64_to_user_ptr(attr->link_create.kprobe_multi.syms);
2999 if (!!uaddrs == !!usyms)
3000 return -EINVAL;
3001
3002 cnt = attr->link_create.kprobe_multi.cnt;
3003 if (!cnt)
3004 return -EINVAL;
3005 if (cnt > MAX_KPROBE_MULTI_CNT)
3006 return -E2BIG;
3007
3008 size = cnt * sizeof(*addrs);
3009 addrs = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL);
3010 if (!addrs)
3011 return -ENOMEM;
3012
3013 ucookies = u64_to_user_ptr(attr->link_create.kprobe_multi.cookies);
3014 if (ucookies) {
3015 cookies = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL);
3016 if (!cookies) {
3017 err = -ENOMEM;
3018 goto error;
3019 }
3020 if (copy_from_user(cookies, ucookies, size)) {
3021 err = -EFAULT;
3022 goto error;
3023 }
3024 }
3025
3026 if (uaddrs) {
3027 if (copy_from_user(addrs, uaddrs, size)) {
3028 err = -EFAULT;
3029 goto error;
3030 }
3031 } else {
3032 struct multi_symbols_sort data = {
3033 .cookies = cookies,
3034 };
3035 struct user_syms us;
3036
3037 err = copy_user_syms(&us, usyms, cnt);
3038 if (err)
3039 goto error;
3040
3041 if (cookies)
3042 data.funcs = us.syms;
3043
3044 sort_r(us.syms, cnt, sizeof(*us.syms), symbols_cmp_r,
3045 symbols_swap_r, &data);
3046
3047 err = ftrace_lookup_symbols(us.syms, cnt, addrs);
3048 free_user_syms(&us);
3049 if (err)
3050 goto error;
3051 }
3052
3053 if (prog->kprobe_override && addrs_check_error_injection_list(addrs, cnt)) {
3054 err = -EINVAL;
3055 goto error;
3056 }
3057
3058 link = kzalloc(sizeof(*link), GFP_KERNEL);
3059 if (!link) {
3060 err = -ENOMEM;
3061 goto error;
3062 }
3063
3064 bpf_link_init(&link->link, BPF_LINK_TYPE_KPROBE_MULTI,
3065 &bpf_kprobe_multi_link_lops, prog);
3066
3067 err = bpf_link_prime(&link->link, &link_primer);
3068 if (err)
3069 goto error;
3070
3071 if (!(flags & BPF_F_KPROBE_MULTI_RETURN))
3072 link->fp.entry_handler = kprobe_multi_link_handler;
3073 if ((flags & BPF_F_KPROBE_MULTI_RETURN) || is_kprobe_session(prog))
3074 link->fp.exit_handler = kprobe_multi_link_exit_handler;
3075 if (is_kprobe_session(prog))
3076 link->fp.entry_data_size = sizeof(u64);
3077
3078 link->addrs = addrs;
3079 link->cookies = cookies;
3080 link->cnt = cnt;
3081 link->flags = flags;
3082
3083 if (cookies) {
3084 /*
3085 * Sorting addresses will trigger sorting cookies as well
3086 * (check bpf_kprobe_multi_cookie_swap). This way we can
3087 * find cookie based on the address in bpf_get_attach_cookie
3088 * helper.
3089 */
3090 sort_r(addrs, cnt, sizeof(*addrs),
3091 bpf_kprobe_multi_cookie_cmp,
3092 bpf_kprobe_multi_cookie_swap,
3093 link);
3094 }
3095
3096 err = get_modules_for_addrs(&link->mods, addrs, cnt);
3097 if (err < 0) {
3098 bpf_link_cleanup(&link_primer);
3099 return err;
3100 }
3101 link->mods_cnt = err;
3102
3103 err = register_fprobe_ips(&link->fp, addrs, cnt);
3104 if (err) {
3105 kprobe_multi_put_modules(link->mods, link->mods_cnt);
3106 bpf_link_cleanup(&link_primer);
3107 return err;
3108 }
3109
3110 return bpf_link_settle(&link_primer);
3111
3112 error:
3113 kfree(link);
3114 kvfree(addrs);
3115 kvfree(cookies);
3116 return err;
3117 }
3118 #else /* !CONFIG_FPROBE */
bpf_kprobe_multi_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)3119 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
3120 {
3121 return -EOPNOTSUPP;
3122 }
bpf_kprobe_multi_cookie(struct bpf_run_ctx * ctx)3123 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx)
3124 {
3125 return 0;
3126 }
bpf_kprobe_multi_entry_ip(struct bpf_run_ctx * ctx)3127 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
3128 {
3129 return 0;
3130 }
3131 #endif
3132
3133 #ifdef CONFIG_UPROBES
3134 struct bpf_uprobe_multi_link;
3135
3136 struct bpf_uprobe {
3137 struct bpf_uprobe_multi_link *link;
3138 loff_t offset;
3139 unsigned long ref_ctr_offset;
3140 u64 cookie;
3141 struct uprobe *uprobe;
3142 struct uprobe_consumer consumer;
3143 bool session;
3144 };
3145
3146 struct bpf_uprobe_multi_link {
3147 struct path path;
3148 struct bpf_link link;
3149 u32 cnt;
3150 u32 flags;
3151 struct bpf_uprobe *uprobes;
3152 struct task_struct *task;
3153 };
3154
3155 struct bpf_uprobe_multi_run_ctx {
3156 struct bpf_session_run_ctx session_ctx;
3157 unsigned long entry_ip;
3158 struct bpf_uprobe *uprobe;
3159 };
3160
bpf_uprobe_unregister(struct bpf_uprobe * uprobes,u32 cnt)3161 static void bpf_uprobe_unregister(struct bpf_uprobe *uprobes, u32 cnt)
3162 {
3163 u32 i;
3164
3165 for (i = 0; i < cnt; i++)
3166 uprobe_unregister_nosync(uprobes[i].uprobe, &uprobes[i].consumer);
3167
3168 if (cnt)
3169 uprobe_unregister_sync();
3170 }
3171
bpf_uprobe_multi_link_release(struct bpf_link * link)3172 static void bpf_uprobe_multi_link_release(struct bpf_link *link)
3173 {
3174 struct bpf_uprobe_multi_link *umulti_link;
3175
3176 umulti_link = container_of(link, struct bpf_uprobe_multi_link, link);
3177 bpf_uprobe_unregister(umulti_link->uprobes, umulti_link->cnt);
3178 if (umulti_link->task)
3179 put_task_struct(umulti_link->task);
3180 path_put(&umulti_link->path);
3181 }
3182
bpf_uprobe_multi_link_dealloc(struct bpf_link * link)3183 static void bpf_uprobe_multi_link_dealloc(struct bpf_link *link)
3184 {
3185 struct bpf_uprobe_multi_link *umulti_link;
3186
3187 umulti_link = container_of(link, struct bpf_uprobe_multi_link, link);
3188 kvfree(umulti_link->uprobes);
3189 kfree(umulti_link);
3190 }
3191
bpf_uprobe_multi_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)3192 static int bpf_uprobe_multi_link_fill_link_info(const struct bpf_link *link,
3193 struct bpf_link_info *info)
3194 {
3195 u64 __user *uref_ctr_offsets = u64_to_user_ptr(info->uprobe_multi.ref_ctr_offsets);
3196 u64 __user *ucookies = u64_to_user_ptr(info->uprobe_multi.cookies);
3197 u64 __user *uoffsets = u64_to_user_ptr(info->uprobe_multi.offsets);
3198 u64 __user *upath = u64_to_user_ptr(info->uprobe_multi.path);
3199 u32 upath_size = info->uprobe_multi.path_size;
3200 struct bpf_uprobe_multi_link *umulti_link;
3201 u32 ucount = info->uprobe_multi.count;
3202 int err = 0, i;
3203 char *p, *buf;
3204 long left = 0;
3205
3206 if (!upath ^ !upath_size)
3207 return -EINVAL;
3208
3209 if ((uoffsets || uref_ctr_offsets || ucookies) && !ucount)
3210 return -EINVAL;
3211
3212 umulti_link = container_of(link, struct bpf_uprobe_multi_link, link);
3213 info->uprobe_multi.count = umulti_link->cnt;
3214 info->uprobe_multi.flags = umulti_link->flags;
3215 info->uprobe_multi.pid = umulti_link->task ?
3216 task_pid_nr_ns(umulti_link->task, task_active_pid_ns(current)) : 0;
3217
3218 upath_size = upath_size ? min_t(u32, upath_size, PATH_MAX) : PATH_MAX;
3219 buf = kmalloc(upath_size, GFP_KERNEL);
3220 if (!buf)
3221 return -ENOMEM;
3222 p = d_path(&umulti_link->path, buf, upath_size);
3223 if (IS_ERR(p)) {
3224 kfree(buf);
3225 return PTR_ERR(p);
3226 }
3227 upath_size = buf + upath_size - p;
3228
3229 if (upath)
3230 left = copy_to_user(upath, p, upath_size);
3231 kfree(buf);
3232 if (left)
3233 return -EFAULT;
3234 info->uprobe_multi.path_size = upath_size;
3235
3236 if (!uoffsets && !ucookies && !uref_ctr_offsets)
3237 return 0;
3238
3239 if (ucount < umulti_link->cnt)
3240 err = -ENOSPC;
3241 else
3242 ucount = umulti_link->cnt;
3243
3244 for (i = 0; i < ucount; i++) {
3245 if (uoffsets &&
3246 put_user(umulti_link->uprobes[i].offset, uoffsets + i))
3247 return -EFAULT;
3248 if (uref_ctr_offsets &&
3249 put_user(umulti_link->uprobes[i].ref_ctr_offset, uref_ctr_offsets + i))
3250 return -EFAULT;
3251 if (ucookies &&
3252 put_user(umulti_link->uprobes[i].cookie, ucookies + i))
3253 return -EFAULT;
3254 }
3255
3256 return err;
3257 }
3258
3259 static const struct bpf_link_ops bpf_uprobe_multi_link_lops = {
3260 .release = bpf_uprobe_multi_link_release,
3261 .dealloc_deferred = bpf_uprobe_multi_link_dealloc,
3262 .fill_link_info = bpf_uprobe_multi_link_fill_link_info,
3263 };
3264
uprobe_prog_run(struct bpf_uprobe * uprobe,unsigned long entry_ip,struct pt_regs * regs,bool is_return,void * data)3265 static int uprobe_prog_run(struct bpf_uprobe *uprobe,
3266 unsigned long entry_ip,
3267 struct pt_regs *regs,
3268 bool is_return, void *data)
3269 {
3270 struct bpf_uprobe_multi_link *link = uprobe->link;
3271 struct bpf_uprobe_multi_run_ctx run_ctx = {
3272 .session_ctx = {
3273 .is_return = is_return,
3274 .data = data,
3275 },
3276 .entry_ip = entry_ip,
3277 .uprobe = uprobe,
3278 };
3279 struct bpf_prog *prog = link->link.prog;
3280 bool sleepable = prog->sleepable;
3281 struct bpf_run_ctx *old_run_ctx;
3282 int err;
3283
3284 if (link->task && !same_thread_group(current, link->task))
3285 return 0;
3286
3287 if (sleepable)
3288 rcu_read_lock_trace();
3289 else
3290 rcu_read_lock();
3291
3292 migrate_disable();
3293
3294 old_run_ctx = bpf_set_run_ctx(&run_ctx.session_ctx.run_ctx);
3295 err = bpf_prog_run(link->link.prog, regs);
3296 bpf_reset_run_ctx(old_run_ctx);
3297
3298 migrate_enable();
3299
3300 if (sleepable)
3301 rcu_read_unlock_trace();
3302 else
3303 rcu_read_unlock();
3304 return err;
3305 }
3306
3307 static bool
uprobe_multi_link_filter(struct uprobe_consumer * con,struct mm_struct * mm)3308 uprobe_multi_link_filter(struct uprobe_consumer *con, struct mm_struct *mm)
3309 {
3310 struct bpf_uprobe *uprobe;
3311
3312 uprobe = container_of(con, struct bpf_uprobe, consumer);
3313 return uprobe->link->task->mm == mm;
3314 }
3315
3316 static int
uprobe_multi_link_handler(struct uprobe_consumer * con,struct pt_regs * regs,__u64 * data)3317 uprobe_multi_link_handler(struct uprobe_consumer *con, struct pt_regs *regs,
3318 __u64 *data)
3319 {
3320 struct bpf_uprobe *uprobe;
3321 int ret;
3322
3323 uprobe = container_of(con, struct bpf_uprobe, consumer);
3324 ret = uprobe_prog_run(uprobe, instruction_pointer(regs), regs, false, data);
3325 if (uprobe->session)
3326 return ret ? UPROBE_HANDLER_IGNORE : 0;
3327 return 0;
3328 }
3329
3330 static int
uprobe_multi_link_ret_handler(struct uprobe_consumer * con,unsigned long func,struct pt_regs * regs,__u64 * data)3331 uprobe_multi_link_ret_handler(struct uprobe_consumer *con, unsigned long func, struct pt_regs *regs,
3332 __u64 *data)
3333 {
3334 struct bpf_uprobe *uprobe;
3335
3336 uprobe = container_of(con, struct bpf_uprobe, consumer);
3337 uprobe_prog_run(uprobe, func, regs, true, data);
3338 return 0;
3339 }
3340
bpf_uprobe_multi_entry_ip(struct bpf_run_ctx * ctx)3341 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
3342 {
3343 struct bpf_uprobe_multi_run_ctx *run_ctx;
3344
3345 run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx,
3346 session_ctx.run_ctx);
3347 return run_ctx->entry_ip;
3348 }
3349
bpf_uprobe_multi_cookie(struct bpf_run_ctx * ctx)3350 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx)
3351 {
3352 struct bpf_uprobe_multi_run_ctx *run_ctx;
3353
3354 run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx,
3355 session_ctx.run_ctx);
3356 return run_ctx->uprobe->cookie;
3357 }
3358
bpf_uprobe_multi_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)3359 int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
3360 {
3361 struct bpf_uprobe_multi_link *link = NULL;
3362 unsigned long __user *uref_ctr_offsets;
3363 struct bpf_link_primer link_primer;
3364 struct bpf_uprobe *uprobes = NULL;
3365 struct task_struct *task = NULL;
3366 unsigned long __user *uoffsets;
3367 u64 __user *ucookies;
3368 void __user *upath;
3369 u32 flags, cnt, i;
3370 struct path path;
3371 char *name;
3372 pid_t pid;
3373 int err;
3374
3375 /* no support for 32bit archs yet */
3376 if (sizeof(u64) != sizeof(void *))
3377 return -EOPNOTSUPP;
3378
3379 if (!is_uprobe_multi(prog))
3380 return -EINVAL;
3381
3382 flags = attr->link_create.uprobe_multi.flags;
3383 if (flags & ~BPF_F_UPROBE_MULTI_RETURN)
3384 return -EINVAL;
3385
3386 /*
3387 * path, offsets and cnt are mandatory,
3388 * ref_ctr_offsets and cookies are optional
3389 */
3390 upath = u64_to_user_ptr(attr->link_create.uprobe_multi.path);
3391 uoffsets = u64_to_user_ptr(attr->link_create.uprobe_multi.offsets);
3392 cnt = attr->link_create.uprobe_multi.cnt;
3393 pid = attr->link_create.uprobe_multi.pid;
3394
3395 if (!upath || !uoffsets || !cnt || pid < 0)
3396 return -EINVAL;
3397 if (cnt > MAX_UPROBE_MULTI_CNT)
3398 return -E2BIG;
3399
3400 uref_ctr_offsets = u64_to_user_ptr(attr->link_create.uprobe_multi.ref_ctr_offsets);
3401 ucookies = u64_to_user_ptr(attr->link_create.uprobe_multi.cookies);
3402
3403 name = strndup_user(upath, PATH_MAX);
3404 if (IS_ERR(name)) {
3405 err = PTR_ERR(name);
3406 return err;
3407 }
3408
3409 err = kern_path(name, LOOKUP_FOLLOW, &path);
3410 kfree(name);
3411 if (err)
3412 return err;
3413
3414 if (!d_is_reg(path.dentry)) {
3415 err = -EBADF;
3416 goto error_path_put;
3417 }
3418
3419 if (pid) {
3420 task = get_pid_task(find_vpid(pid), PIDTYPE_TGID);
3421 if (!task) {
3422 err = -ESRCH;
3423 goto error_path_put;
3424 }
3425 }
3426
3427 err = -ENOMEM;
3428
3429 link = kzalloc(sizeof(*link), GFP_KERNEL);
3430 uprobes = kvcalloc(cnt, sizeof(*uprobes), GFP_KERNEL);
3431
3432 if (!uprobes || !link)
3433 goto error_free;
3434
3435 for (i = 0; i < cnt; i++) {
3436 if (__get_user(uprobes[i].offset, uoffsets + i)) {
3437 err = -EFAULT;
3438 goto error_free;
3439 }
3440 if (uprobes[i].offset < 0) {
3441 err = -EINVAL;
3442 goto error_free;
3443 }
3444 if (uref_ctr_offsets && __get_user(uprobes[i].ref_ctr_offset, uref_ctr_offsets + i)) {
3445 err = -EFAULT;
3446 goto error_free;
3447 }
3448 if (ucookies && __get_user(uprobes[i].cookie, ucookies + i)) {
3449 err = -EFAULT;
3450 goto error_free;
3451 }
3452
3453 uprobes[i].link = link;
3454
3455 if (!(flags & BPF_F_UPROBE_MULTI_RETURN))
3456 uprobes[i].consumer.handler = uprobe_multi_link_handler;
3457 if (flags & BPF_F_UPROBE_MULTI_RETURN || is_uprobe_session(prog))
3458 uprobes[i].consumer.ret_handler = uprobe_multi_link_ret_handler;
3459 if (is_uprobe_session(prog))
3460 uprobes[i].session = true;
3461 if (pid)
3462 uprobes[i].consumer.filter = uprobe_multi_link_filter;
3463 }
3464
3465 link->cnt = cnt;
3466 link->uprobes = uprobes;
3467 link->path = path;
3468 link->task = task;
3469 link->flags = flags;
3470
3471 bpf_link_init(&link->link, BPF_LINK_TYPE_UPROBE_MULTI,
3472 &bpf_uprobe_multi_link_lops, prog);
3473
3474 for (i = 0; i < cnt; i++) {
3475 uprobes[i].uprobe = uprobe_register(d_real_inode(link->path.dentry),
3476 uprobes[i].offset,
3477 uprobes[i].ref_ctr_offset,
3478 &uprobes[i].consumer);
3479 if (IS_ERR(uprobes[i].uprobe)) {
3480 err = PTR_ERR(uprobes[i].uprobe);
3481 link->cnt = i;
3482 goto error_unregister;
3483 }
3484 }
3485
3486 err = bpf_link_prime(&link->link, &link_primer);
3487 if (err)
3488 goto error_unregister;
3489
3490 return bpf_link_settle(&link_primer);
3491
3492 error_unregister:
3493 bpf_uprobe_unregister(uprobes, link->cnt);
3494
3495 error_free:
3496 kvfree(uprobes);
3497 kfree(link);
3498 if (task)
3499 put_task_struct(task);
3500 error_path_put:
3501 path_put(&path);
3502 return err;
3503 }
3504 #else /* !CONFIG_UPROBES */
bpf_uprobe_multi_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)3505 int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
3506 {
3507 return -EOPNOTSUPP;
3508 }
bpf_uprobe_multi_cookie(struct bpf_run_ctx * ctx)3509 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx)
3510 {
3511 return 0;
3512 }
bpf_uprobe_multi_entry_ip(struct bpf_run_ctx * ctx)3513 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
3514 {
3515 return 0;
3516 }
3517 #endif /* CONFIG_UPROBES */
3518
3519 __bpf_kfunc_start_defs();
3520
bpf_session_is_return(void)3521 __bpf_kfunc bool bpf_session_is_return(void)
3522 {
3523 struct bpf_session_run_ctx *session_ctx;
3524
3525 session_ctx = container_of(current->bpf_ctx, struct bpf_session_run_ctx, run_ctx);
3526 return session_ctx->is_return;
3527 }
3528
bpf_session_cookie(void)3529 __bpf_kfunc __u64 *bpf_session_cookie(void)
3530 {
3531 struct bpf_session_run_ctx *session_ctx;
3532
3533 session_ctx = container_of(current->bpf_ctx, struct bpf_session_run_ctx, run_ctx);
3534 return session_ctx->data;
3535 }
3536
3537 __bpf_kfunc_end_defs();
3538
3539 BTF_KFUNCS_START(kprobe_multi_kfunc_set_ids)
BTF_ID_FLAGS(func,bpf_session_is_return)3540 BTF_ID_FLAGS(func, bpf_session_is_return)
3541 BTF_ID_FLAGS(func, bpf_session_cookie)
3542 BTF_KFUNCS_END(kprobe_multi_kfunc_set_ids)
3543
3544 static int bpf_kprobe_multi_filter(const struct bpf_prog *prog, u32 kfunc_id)
3545 {
3546 if (!btf_id_set8_contains(&kprobe_multi_kfunc_set_ids, kfunc_id))
3547 return 0;
3548
3549 if (!is_kprobe_session(prog) && !is_uprobe_session(prog))
3550 return -EACCES;
3551
3552 return 0;
3553 }
3554
3555 static const struct btf_kfunc_id_set bpf_kprobe_multi_kfunc_set = {
3556 .owner = THIS_MODULE,
3557 .set = &kprobe_multi_kfunc_set_ids,
3558 .filter = bpf_kprobe_multi_filter,
3559 };
3560
bpf_kprobe_multi_kfuncs_init(void)3561 static int __init bpf_kprobe_multi_kfuncs_init(void)
3562 {
3563 return register_btf_kfunc_id_set(BPF_PROG_TYPE_KPROBE, &bpf_kprobe_multi_kfunc_set);
3564 }
3565
3566 late_initcall(bpf_kprobe_multi_kfuncs_init);
3567
3568 __bpf_kfunc_start_defs();
3569
bpf_send_signal_task(struct task_struct * task,int sig,enum pid_type type,u64 value)3570 __bpf_kfunc int bpf_send_signal_task(struct task_struct *task, int sig, enum pid_type type,
3571 u64 value)
3572 {
3573 if (type != PIDTYPE_PID && type != PIDTYPE_TGID)
3574 return -EINVAL;
3575
3576 return bpf_send_signal_common(sig, type, task, value);
3577 }
3578
3579 __bpf_kfunc_end_defs();
3580