1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2011-2015 PLUMgrid, http://plumgrid.com
3 * Copyright (c) 2016 Facebook
4 */
5 #include <linux/kernel.h>
6 #include <linux/types.h>
7 #include <linux/slab.h>
8 #include <linux/bpf.h>
9 #include <linux/bpf_verifier.h>
10 #include <linux/bpf_perf_event.h>
11 #include <linux/btf.h>
12 #include <linux/filter.h>
13 #include <linux/uaccess.h>
14 #include <linux/ctype.h>
15 #include <linux/kprobes.h>
16 #include <linux/spinlock.h>
17 #include <linux/syscalls.h>
18 #include <linux/error-injection.h>
19 #include <linux/btf_ids.h>
20 #include <linux/bpf_lsm.h>
21 #include <linux/fprobe.h>
22 #include <linux/bsearch.h>
23 #include <linux/sort.h>
24 #include <linux/key.h>
25 #include <linux/verification.h>
26 #include <linux/namei.h>
27
28 #include <net/bpf_sk_storage.h>
29
30 #include <uapi/linux/bpf.h>
31 #include <uapi/linux/btf.h>
32
33 #include <asm/tlb.h>
34
35 #include "trace_probe.h"
36 #include "trace.h"
37
38 #define CREATE_TRACE_POINTS
39 #include "bpf_trace.h"
40
41 #define bpf_event_rcu_dereference(p) \
42 rcu_dereference_protected(p, lockdep_is_held(&bpf_event_mutex))
43
44 #define MAX_UPROBE_MULTI_CNT (1U << 20)
45 #define MAX_KPROBE_MULTI_CNT (1U << 20)
46
47 #ifdef CONFIG_MODULES
48 struct bpf_trace_module {
49 struct module *module;
50 struct list_head list;
51 };
52
53 static LIST_HEAD(bpf_trace_modules);
54 static DEFINE_MUTEX(bpf_module_mutex);
55
bpf_get_raw_tracepoint_module(const char * name)56 static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name)
57 {
58 struct bpf_raw_event_map *btp, *ret = NULL;
59 struct bpf_trace_module *btm;
60 unsigned int i;
61
62 mutex_lock(&bpf_module_mutex);
63 list_for_each_entry(btm, &bpf_trace_modules, list) {
64 for (i = 0; i < btm->module->num_bpf_raw_events; ++i) {
65 btp = &btm->module->bpf_raw_events[i];
66 if (!strcmp(btp->tp->name, name)) {
67 if (try_module_get(btm->module))
68 ret = btp;
69 goto out;
70 }
71 }
72 }
73 out:
74 mutex_unlock(&bpf_module_mutex);
75 return ret;
76 }
77 #else
bpf_get_raw_tracepoint_module(const char * name)78 static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name)
79 {
80 return NULL;
81 }
82 #endif /* CONFIG_MODULES */
83
84 u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
85 u64 bpf_get_stack(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
86
87 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size,
88 u64 flags, const struct btf **btf,
89 s32 *btf_id);
90 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx);
91 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx);
92
93 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx);
94 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx);
95
96 /**
97 * trace_call_bpf - invoke BPF program
98 * @call: tracepoint event
99 * @ctx: opaque context pointer
100 *
101 * kprobe handlers execute BPF programs via this helper.
102 * Can be used from static tracepoints in the future.
103 *
104 * Return: BPF programs always return an integer which is interpreted by
105 * kprobe handler as:
106 * 0 - return from kprobe (event is filtered out)
107 * 1 - store kprobe event into ring buffer
108 * Other values are reserved and currently alias to 1
109 */
trace_call_bpf(struct trace_event_call * call,void * ctx)110 unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx)
111 {
112 unsigned int ret;
113
114 cant_sleep();
115
116 if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) {
117 /*
118 * since some bpf program is already running on this cpu,
119 * don't call into another bpf program (same or different)
120 * and don't send kprobe event into ring-buffer,
121 * so return zero here
122 */
123 rcu_read_lock();
124 bpf_prog_inc_misses_counters(rcu_dereference(call->prog_array));
125 rcu_read_unlock();
126 ret = 0;
127 goto out;
128 }
129
130 /*
131 * Instead of moving rcu_read_lock/rcu_dereference/rcu_read_unlock
132 * to all call sites, we did a bpf_prog_array_valid() there to check
133 * whether call->prog_array is empty or not, which is
134 * a heuristic to speed up execution.
135 *
136 * If bpf_prog_array_valid() fetched prog_array was
137 * non-NULL, we go into trace_call_bpf() and do the actual
138 * proper rcu_dereference() under RCU lock.
139 * If it turns out that prog_array is NULL then, we bail out.
140 * For the opposite, if the bpf_prog_array_valid() fetched pointer
141 * was NULL, you'll skip the prog_array with the risk of missing
142 * out of events when it was updated in between this and the
143 * rcu_dereference() which is accepted risk.
144 */
145 rcu_read_lock();
146 ret = bpf_prog_run_array(rcu_dereference(call->prog_array),
147 ctx, bpf_prog_run);
148 rcu_read_unlock();
149
150 out:
151 __this_cpu_dec(bpf_prog_active);
152
153 return ret;
154 }
155
156 #ifdef CONFIG_BPF_KPROBE_OVERRIDE
BPF_CALL_2(bpf_override_return,struct pt_regs *,regs,unsigned long,rc)157 BPF_CALL_2(bpf_override_return, struct pt_regs *, regs, unsigned long, rc)
158 {
159 regs_set_return_value(regs, rc);
160 override_function_with_return(regs);
161 return 0;
162 }
163
164 static const struct bpf_func_proto bpf_override_return_proto = {
165 .func = bpf_override_return,
166 .gpl_only = true,
167 .ret_type = RET_INTEGER,
168 .arg1_type = ARG_PTR_TO_CTX,
169 .arg2_type = ARG_ANYTHING,
170 };
171 #endif
172
173 static __always_inline int
bpf_probe_read_user_common(void * dst,u32 size,const void __user * unsafe_ptr)174 bpf_probe_read_user_common(void *dst, u32 size, const void __user *unsafe_ptr)
175 {
176 int ret;
177
178 ret = copy_from_user_nofault(dst, unsafe_ptr, size);
179 if (unlikely(ret < 0))
180 memset(dst, 0, size);
181 return ret;
182 }
183
BPF_CALL_3(bpf_probe_read_user,void *,dst,u32,size,const void __user *,unsafe_ptr)184 BPF_CALL_3(bpf_probe_read_user, void *, dst, u32, size,
185 const void __user *, unsafe_ptr)
186 {
187 return bpf_probe_read_user_common(dst, size, unsafe_ptr);
188 }
189
190 const struct bpf_func_proto bpf_probe_read_user_proto = {
191 .func = bpf_probe_read_user,
192 .gpl_only = true,
193 .ret_type = RET_INTEGER,
194 .arg1_type = ARG_PTR_TO_UNINIT_MEM,
195 .arg2_type = ARG_CONST_SIZE_OR_ZERO,
196 .arg3_type = ARG_ANYTHING,
197 };
198
199 static __always_inline int
bpf_probe_read_user_str_common(void * dst,u32 size,const void __user * unsafe_ptr)200 bpf_probe_read_user_str_common(void *dst, u32 size,
201 const void __user *unsafe_ptr)
202 {
203 int ret;
204
205 /*
206 * NB: We rely on strncpy_from_user() not copying junk past the NUL
207 * terminator into `dst`.
208 *
209 * strncpy_from_user() does long-sized strides in the fast path. If the
210 * strncpy does not mask out the bytes after the NUL in `unsafe_ptr`,
211 * then there could be junk after the NUL in `dst`. If user takes `dst`
212 * and keys a hash map with it, then semantically identical strings can
213 * occupy multiple entries in the map.
214 */
215 ret = strncpy_from_user_nofault(dst, unsafe_ptr, size);
216 if (unlikely(ret < 0))
217 memset(dst, 0, size);
218 return ret;
219 }
220
BPF_CALL_3(bpf_probe_read_user_str,void *,dst,u32,size,const void __user *,unsafe_ptr)221 BPF_CALL_3(bpf_probe_read_user_str, void *, dst, u32, size,
222 const void __user *, unsafe_ptr)
223 {
224 return bpf_probe_read_user_str_common(dst, size, unsafe_ptr);
225 }
226
227 const struct bpf_func_proto bpf_probe_read_user_str_proto = {
228 .func = bpf_probe_read_user_str,
229 .gpl_only = true,
230 .ret_type = RET_INTEGER,
231 .arg1_type = ARG_PTR_TO_UNINIT_MEM,
232 .arg2_type = ARG_CONST_SIZE_OR_ZERO,
233 .arg3_type = ARG_ANYTHING,
234 };
235
BPF_CALL_3(bpf_probe_read_kernel,void *,dst,u32,size,const void *,unsafe_ptr)236 BPF_CALL_3(bpf_probe_read_kernel, void *, dst, u32, size,
237 const void *, unsafe_ptr)
238 {
239 return bpf_probe_read_kernel_common(dst, size, unsafe_ptr);
240 }
241
242 const struct bpf_func_proto bpf_probe_read_kernel_proto = {
243 .func = bpf_probe_read_kernel,
244 .gpl_only = true,
245 .ret_type = RET_INTEGER,
246 .arg1_type = ARG_PTR_TO_UNINIT_MEM,
247 .arg2_type = ARG_CONST_SIZE_OR_ZERO,
248 .arg3_type = ARG_ANYTHING,
249 };
250
251 static __always_inline int
bpf_probe_read_kernel_str_common(void * dst,u32 size,const void * unsafe_ptr)252 bpf_probe_read_kernel_str_common(void *dst, u32 size, const void *unsafe_ptr)
253 {
254 int ret;
255
256 /*
257 * The strncpy_from_kernel_nofault() call will likely not fill the
258 * entire buffer, but that's okay in this circumstance as we're probing
259 * arbitrary memory anyway similar to bpf_probe_read_*() and might
260 * as well probe the stack. Thus, memory is explicitly cleared
261 * only in error case, so that improper users ignoring return
262 * code altogether don't copy garbage; otherwise length of string
263 * is returned that can be used for bpf_perf_event_output() et al.
264 */
265 ret = strncpy_from_kernel_nofault(dst, unsafe_ptr, size);
266 if (unlikely(ret < 0))
267 memset(dst, 0, size);
268 return ret;
269 }
270
BPF_CALL_3(bpf_probe_read_kernel_str,void *,dst,u32,size,const void *,unsafe_ptr)271 BPF_CALL_3(bpf_probe_read_kernel_str, void *, dst, u32, size,
272 const void *, unsafe_ptr)
273 {
274 return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr);
275 }
276
277 const struct bpf_func_proto bpf_probe_read_kernel_str_proto = {
278 .func = bpf_probe_read_kernel_str,
279 .gpl_only = true,
280 .ret_type = RET_INTEGER,
281 .arg1_type = ARG_PTR_TO_UNINIT_MEM,
282 .arg2_type = ARG_CONST_SIZE_OR_ZERO,
283 .arg3_type = ARG_ANYTHING,
284 };
285
286 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
BPF_CALL_3(bpf_probe_read_compat,void *,dst,u32,size,const void *,unsafe_ptr)287 BPF_CALL_3(bpf_probe_read_compat, void *, dst, u32, size,
288 const void *, unsafe_ptr)
289 {
290 if ((unsigned long)unsafe_ptr < TASK_SIZE) {
291 return bpf_probe_read_user_common(dst, size,
292 (__force void __user *)unsafe_ptr);
293 }
294 return bpf_probe_read_kernel_common(dst, size, unsafe_ptr);
295 }
296
297 static const struct bpf_func_proto bpf_probe_read_compat_proto = {
298 .func = bpf_probe_read_compat,
299 .gpl_only = true,
300 .ret_type = RET_INTEGER,
301 .arg1_type = ARG_PTR_TO_UNINIT_MEM,
302 .arg2_type = ARG_CONST_SIZE_OR_ZERO,
303 .arg3_type = ARG_ANYTHING,
304 };
305
BPF_CALL_3(bpf_probe_read_compat_str,void *,dst,u32,size,const void *,unsafe_ptr)306 BPF_CALL_3(bpf_probe_read_compat_str, void *, dst, u32, size,
307 const void *, unsafe_ptr)
308 {
309 if ((unsigned long)unsafe_ptr < TASK_SIZE) {
310 return bpf_probe_read_user_str_common(dst, size,
311 (__force void __user *)unsafe_ptr);
312 }
313 return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr);
314 }
315
316 static const struct bpf_func_proto bpf_probe_read_compat_str_proto = {
317 .func = bpf_probe_read_compat_str,
318 .gpl_only = true,
319 .ret_type = RET_INTEGER,
320 .arg1_type = ARG_PTR_TO_UNINIT_MEM,
321 .arg2_type = ARG_CONST_SIZE_OR_ZERO,
322 .arg3_type = ARG_ANYTHING,
323 };
324 #endif /* CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE */
325
BPF_CALL_3(bpf_probe_write_user,void __user *,unsafe_ptr,const void *,src,u32,size)326 BPF_CALL_3(bpf_probe_write_user, void __user *, unsafe_ptr, const void *, src,
327 u32, size)
328 {
329 /*
330 * Ensure we're in user context which is safe for the helper to
331 * run. This helper has no business in a kthread.
332 *
333 * access_ok() should prevent writing to non-user memory, but in
334 * some situations (nommu, temporary switch, etc) access_ok() does
335 * not provide enough validation, hence the check on KERNEL_DS.
336 *
337 * nmi_uaccess_okay() ensures the probe is not run in an interim
338 * state, when the task or mm are switched. This is specifically
339 * required to prevent the use of temporary mm.
340 */
341
342 if (unlikely(in_interrupt() ||
343 current->flags & (PF_KTHREAD | PF_EXITING)))
344 return -EPERM;
345 if (unlikely(!nmi_uaccess_okay()))
346 return -EPERM;
347
348 return copy_to_user_nofault(unsafe_ptr, src, size);
349 }
350
351 static const struct bpf_func_proto bpf_probe_write_user_proto = {
352 .func = bpf_probe_write_user,
353 .gpl_only = true,
354 .ret_type = RET_INTEGER,
355 .arg1_type = ARG_ANYTHING,
356 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
357 .arg3_type = ARG_CONST_SIZE,
358 };
359
bpf_get_probe_write_proto(void)360 static const struct bpf_func_proto *bpf_get_probe_write_proto(void)
361 {
362 if (!capable(CAP_SYS_ADMIN))
363 return NULL;
364
365 pr_warn_ratelimited("%s[%d] is installing a program with bpf_probe_write_user helper that may corrupt user memory!",
366 current->comm, task_pid_nr(current));
367
368 return &bpf_probe_write_user_proto;
369 }
370
371 #define MAX_TRACE_PRINTK_VARARGS 3
372 #define BPF_TRACE_PRINTK_SIZE 1024
373
BPF_CALL_5(bpf_trace_printk,char *,fmt,u32,fmt_size,u64,arg1,u64,arg2,u64,arg3)374 BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1,
375 u64, arg2, u64, arg3)
376 {
377 u64 args[MAX_TRACE_PRINTK_VARARGS] = { arg1, arg2, arg3 };
378 struct bpf_bprintf_data data = {
379 .get_bin_args = true,
380 .get_buf = true,
381 };
382 int ret;
383
384 ret = bpf_bprintf_prepare(fmt, fmt_size, args,
385 MAX_TRACE_PRINTK_VARARGS, &data);
386 if (ret < 0)
387 return ret;
388
389 ret = bstr_printf(data.buf, MAX_BPRINTF_BUF, fmt, data.bin_args);
390
391 trace_bpf_trace_printk(data.buf);
392
393 bpf_bprintf_cleanup(&data);
394
395 return ret;
396 }
397
398 static const struct bpf_func_proto bpf_trace_printk_proto = {
399 .func = bpf_trace_printk,
400 .gpl_only = true,
401 .ret_type = RET_INTEGER,
402 .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY,
403 .arg2_type = ARG_CONST_SIZE,
404 };
405
__set_printk_clr_event(void)406 static void __set_printk_clr_event(void)
407 {
408 /*
409 * This program might be calling bpf_trace_printk,
410 * so enable the associated bpf_trace/bpf_trace_printk event.
411 * Repeat this each time as it is possible a user has
412 * disabled bpf_trace_printk events. By loading a program
413 * calling bpf_trace_printk() however the user has expressed
414 * the intent to see such events.
415 */
416 if (trace_set_clr_event("bpf_trace", "bpf_trace_printk", 1))
417 pr_warn_ratelimited("could not enable bpf_trace_printk events");
418 }
419
bpf_get_trace_printk_proto(void)420 const struct bpf_func_proto *bpf_get_trace_printk_proto(void)
421 {
422 __set_printk_clr_event();
423 return &bpf_trace_printk_proto;
424 }
425
BPF_CALL_4(bpf_trace_vprintk,char *,fmt,u32,fmt_size,const void *,args,u32,data_len)426 BPF_CALL_4(bpf_trace_vprintk, char *, fmt, u32, fmt_size, const void *, args,
427 u32, data_len)
428 {
429 struct bpf_bprintf_data data = {
430 .get_bin_args = true,
431 .get_buf = true,
432 };
433 int ret, num_args;
434
435 if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 ||
436 (data_len && !args))
437 return -EINVAL;
438 num_args = data_len / 8;
439
440 ret = bpf_bprintf_prepare(fmt, fmt_size, args, num_args, &data);
441 if (ret < 0)
442 return ret;
443
444 ret = bstr_printf(data.buf, MAX_BPRINTF_BUF, fmt, data.bin_args);
445
446 trace_bpf_trace_printk(data.buf);
447
448 bpf_bprintf_cleanup(&data);
449
450 return ret;
451 }
452
453 static const struct bpf_func_proto bpf_trace_vprintk_proto = {
454 .func = bpf_trace_vprintk,
455 .gpl_only = true,
456 .ret_type = RET_INTEGER,
457 .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY,
458 .arg2_type = ARG_CONST_SIZE,
459 .arg3_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY,
460 .arg4_type = ARG_CONST_SIZE_OR_ZERO,
461 };
462
bpf_get_trace_vprintk_proto(void)463 const struct bpf_func_proto *bpf_get_trace_vprintk_proto(void)
464 {
465 __set_printk_clr_event();
466 return &bpf_trace_vprintk_proto;
467 }
468
BPF_CALL_5(bpf_seq_printf,struct seq_file *,m,char *,fmt,u32,fmt_size,const void *,args,u32,data_len)469 BPF_CALL_5(bpf_seq_printf, struct seq_file *, m, char *, fmt, u32, fmt_size,
470 const void *, args, u32, data_len)
471 {
472 struct bpf_bprintf_data data = {
473 .get_bin_args = true,
474 };
475 int err, num_args;
476
477 if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 ||
478 (data_len && !args))
479 return -EINVAL;
480 num_args = data_len / 8;
481
482 err = bpf_bprintf_prepare(fmt, fmt_size, args, num_args, &data);
483 if (err < 0)
484 return err;
485
486 seq_bprintf(m, fmt, data.bin_args);
487
488 bpf_bprintf_cleanup(&data);
489
490 return seq_has_overflowed(m) ? -EOVERFLOW : 0;
491 }
492
493 BTF_ID_LIST_SINGLE(btf_seq_file_ids, struct, seq_file)
494
495 static const struct bpf_func_proto bpf_seq_printf_proto = {
496 .func = bpf_seq_printf,
497 .gpl_only = true,
498 .ret_type = RET_INTEGER,
499 .arg1_type = ARG_PTR_TO_BTF_ID,
500 .arg1_btf_id = &btf_seq_file_ids[0],
501 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
502 .arg3_type = ARG_CONST_SIZE,
503 .arg4_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY,
504 .arg5_type = ARG_CONST_SIZE_OR_ZERO,
505 };
506
BPF_CALL_3(bpf_seq_write,struct seq_file *,m,const void *,data,u32,len)507 BPF_CALL_3(bpf_seq_write, struct seq_file *, m, const void *, data, u32, len)
508 {
509 return seq_write(m, data, len) ? -EOVERFLOW : 0;
510 }
511
512 static const struct bpf_func_proto bpf_seq_write_proto = {
513 .func = bpf_seq_write,
514 .gpl_only = true,
515 .ret_type = RET_INTEGER,
516 .arg1_type = ARG_PTR_TO_BTF_ID,
517 .arg1_btf_id = &btf_seq_file_ids[0],
518 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
519 .arg3_type = ARG_CONST_SIZE_OR_ZERO,
520 };
521
BPF_CALL_4(bpf_seq_printf_btf,struct seq_file *,m,struct btf_ptr *,ptr,u32,btf_ptr_size,u64,flags)522 BPF_CALL_4(bpf_seq_printf_btf, struct seq_file *, m, struct btf_ptr *, ptr,
523 u32, btf_ptr_size, u64, flags)
524 {
525 const struct btf *btf;
526 s32 btf_id;
527 int ret;
528
529 ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id);
530 if (ret)
531 return ret;
532
533 return btf_type_seq_show_flags(btf, btf_id, ptr->ptr, m, flags);
534 }
535
536 static const struct bpf_func_proto bpf_seq_printf_btf_proto = {
537 .func = bpf_seq_printf_btf,
538 .gpl_only = true,
539 .ret_type = RET_INTEGER,
540 .arg1_type = ARG_PTR_TO_BTF_ID,
541 .arg1_btf_id = &btf_seq_file_ids[0],
542 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
543 .arg3_type = ARG_CONST_SIZE_OR_ZERO,
544 .arg4_type = ARG_ANYTHING,
545 };
546
547 static __always_inline int
get_map_perf_counter(struct bpf_map * map,u64 flags,u64 * value,u64 * enabled,u64 * running)548 get_map_perf_counter(struct bpf_map *map, u64 flags,
549 u64 *value, u64 *enabled, u64 *running)
550 {
551 struct bpf_array *array = container_of(map, struct bpf_array, map);
552 unsigned int cpu = smp_processor_id();
553 u64 index = flags & BPF_F_INDEX_MASK;
554 struct bpf_event_entry *ee;
555
556 if (unlikely(flags & ~(BPF_F_INDEX_MASK)))
557 return -EINVAL;
558 if (index == BPF_F_CURRENT_CPU)
559 index = cpu;
560 if (unlikely(index >= array->map.max_entries))
561 return -E2BIG;
562
563 ee = READ_ONCE(array->ptrs[index]);
564 if (!ee)
565 return -ENOENT;
566
567 return perf_event_read_local(ee->event, value, enabled, running);
568 }
569
BPF_CALL_2(bpf_perf_event_read,struct bpf_map *,map,u64,flags)570 BPF_CALL_2(bpf_perf_event_read, struct bpf_map *, map, u64, flags)
571 {
572 u64 value = 0;
573 int err;
574
575 err = get_map_perf_counter(map, flags, &value, NULL, NULL);
576 /*
577 * this api is ugly since we miss [-22..-2] range of valid
578 * counter values, but that's uapi
579 */
580 if (err)
581 return err;
582 return value;
583 }
584
585 static const struct bpf_func_proto bpf_perf_event_read_proto = {
586 .func = bpf_perf_event_read,
587 .gpl_only = true,
588 .ret_type = RET_INTEGER,
589 .arg1_type = ARG_CONST_MAP_PTR,
590 .arg2_type = ARG_ANYTHING,
591 };
592
BPF_CALL_4(bpf_perf_event_read_value,struct bpf_map *,map,u64,flags,struct bpf_perf_event_value *,buf,u32,size)593 BPF_CALL_4(bpf_perf_event_read_value, struct bpf_map *, map, u64, flags,
594 struct bpf_perf_event_value *, buf, u32, size)
595 {
596 int err = -EINVAL;
597
598 if (unlikely(size != sizeof(struct bpf_perf_event_value)))
599 goto clear;
600 err = get_map_perf_counter(map, flags, &buf->counter, &buf->enabled,
601 &buf->running);
602 if (unlikely(err))
603 goto clear;
604 return 0;
605 clear:
606 memset(buf, 0, size);
607 return err;
608 }
609
610 static const struct bpf_func_proto bpf_perf_event_read_value_proto = {
611 .func = bpf_perf_event_read_value,
612 .gpl_only = true,
613 .ret_type = RET_INTEGER,
614 .arg1_type = ARG_CONST_MAP_PTR,
615 .arg2_type = ARG_ANYTHING,
616 .arg3_type = ARG_PTR_TO_UNINIT_MEM,
617 .arg4_type = ARG_CONST_SIZE,
618 };
619
620 static __always_inline u64
__bpf_perf_event_output(struct pt_regs * regs,struct bpf_map * map,u64 flags,struct perf_sample_data * sd)621 __bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map,
622 u64 flags, struct perf_sample_data *sd)
623 {
624 struct bpf_array *array = container_of(map, struct bpf_array, map);
625 unsigned int cpu = smp_processor_id();
626 u64 index = flags & BPF_F_INDEX_MASK;
627 struct bpf_event_entry *ee;
628 struct perf_event *event;
629
630 if (index == BPF_F_CURRENT_CPU)
631 index = cpu;
632 if (unlikely(index >= array->map.max_entries))
633 return -E2BIG;
634
635 ee = READ_ONCE(array->ptrs[index]);
636 if (!ee)
637 return -ENOENT;
638
639 event = ee->event;
640 if (unlikely(event->attr.type != PERF_TYPE_SOFTWARE ||
641 event->attr.config != PERF_COUNT_SW_BPF_OUTPUT))
642 return -EINVAL;
643
644 if (unlikely(event->oncpu != cpu))
645 return -EOPNOTSUPP;
646
647 return perf_event_output(event, sd, regs);
648 }
649
650 /*
651 * Support executing tracepoints in normal, irq, and nmi context that each call
652 * bpf_perf_event_output
653 */
654 struct bpf_trace_sample_data {
655 struct perf_sample_data sds[3];
656 };
657
658 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_trace_sds);
659 static DEFINE_PER_CPU(int, bpf_trace_nest_level);
BPF_CALL_5(bpf_perf_event_output,struct pt_regs *,regs,struct bpf_map *,map,u64,flags,void *,data,u64,size)660 BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map,
661 u64, flags, void *, data, u64, size)
662 {
663 struct bpf_trace_sample_data *sds;
664 struct perf_raw_record raw = {
665 .frag = {
666 .size = size,
667 .data = data,
668 },
669 };
670 struct perf_sample_data *sd;
671 int nest_level, err;
672
673 preempt_disable();
674 sds = this_cpu_ptr(&bpf_trace_sds);
675 nest_level = this_cpu_inc_return(bpf_trace_nest_level);
676
677 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(sds->sds))) {
678 err = -EBUSY;
679 goto out;
680 }
681
682 sd = &sds->sds[nest_level - 1];
683
684 if (unlikely(flags & ~(BPF_F_INDEX_MASK))) {
685 err = -EINVAL;
686 goto out;
687 }
688
689 perf_sample_data_init(sd, 0, 0);
690 perf_sample_save_raw_data(sd, &raw);
691
692 err = __bpf_perf_event_output(regs, map, flags, sd);
693 out:
694 this_cpu_dec(bpf_trace_nest_level);
695 preempt_enable();
696 return err;
697 }
698
699 static const struct bpf_func_proto bpf_perf_event_output_proto = {
700 .func = bpf_perf_event_output,
701 .gpl_only = true,
702 .ret_type = RET_INTEGER,
703 .arg1_type = ARG_PTR_TO_CTX,
704 .arg2_type = ARG_CONST_MAP_PTR,
705 .arg3_type = ARG_ANYTHING,
706 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY,
707 .arg5_type = ARG_CONST_SIZE_OR_ZERO,
708 };
709
710 static DEFINE_PER_CPU(int, bpf_event_output_nest_level);
711 struct bpf_nested_pt_regs {
712 struct pt_regs regs[3];
713 };
714 static DEFINE_PER_CPU(struct bpf_nested_pt_regs, bpf_pt_regs);
715 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_misc_sds);
716
bpf_event_output(struct bpf_map * map,u64 flags,void * meta,u64 meta_size,void * ctx,u64 ctx_size,bpf_ctx_copy_t ctx_copy)717 u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
718 void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy)
719 {
720 struct perf_raw_frag frag = {
721 .copy = ctx_copy,
722 .size = ctx_size,
723 .data = ctx,
724 };
725 struct perf_raw_record raw = {
726 .frag = {
727 {
728 .next = ctx_size ? &frag : NULL,
729 },
730 .size = meta_size,
731 .data = meta,
732 },
733 };
734 struct perf_sample_data *sd;
735 struct pt_regs *regs;
736 int nest_level;
737 u64 ret;
738
739 preempt_disable();
740 nest_level = this_cpu_inc_return(bpf_event_output_nest_level);
741
742 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(bpf_misc_sds.sds))) {
743 ret = -EBUSY;
744 goto out;
745 }
746 sd = this_cpu_ptr(&bpf_misc_sds.sds[nest_level - 1]);
747 regs = this_cpu_ptr(&bpf_pt_regs.regs[nest_level - 1]);
748
749 perf_fetch_caller_regs(regs);
750 perf_sample_data_init(sd, 0, 0);
751 perf_sample_save_raw_data(sd, &raw);
752
753 ret = __bpf_perf_event_output(regs, map, flags, sd);
754 out:
755 this_cpu_dec(bpf_event_output_nest_level);
756 preempt_enable();
757 return ret;
758 }
759
BPF_CALL_0(bpf_get_current_task)760 BPF_CALL_0(bpf_get_current_task)
761 {
762 return (long) current;
763 }
764
765 const struct bpf_func_proto bpf_get_current_task_proto = {
766 .func = bpf_get_current_task,
767 .gpl_only = true,
768 .ret_type = RET_INTEGER,
769 };
770
BPF_CALL_0(bpf_get_current_task_btf)771 BPF_CALL_0(bpf_get_current_task_btf)
772 {
773 return (unsigned long) current;
774 }
775
776 const struct bpf_func_proto bpf_get_current_task_btf_proto = {
777 .func = bpf_get_current_task_btf,
778 .gpl_only = true,
779 .ret_type = RET_PTR_TO_BTF_ID_TRUSTED,
780 .ret_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK],
781 };
782
BPF_CALL_1(bpf_task_pt_regs,struct task_struct *,task)783 BPF_CALL_1(bpf_task_pt_regs, struct task_struct *, task)
784 {
785 return (unsigned long) task_pt_regs(task);
786 }
787
788 BTF_ID_LIST(bpf_task_pt_regs_ids)
789 BTF_ID(struct, pt_regs)
790
791 const struct bpf_func_proto bpf_task_pt_regs_proto = {
792 .func = bpf_task_pt_regs,
793 .gpl_only = true,
794 .arg1_type = ARG_PTR_TO_BTF_ID,
795 .arg1_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK],
796 .ret_type = RET_PTR_TO_BTF_ID,
797 .ret_btf_id = &bpf_task_pt_regs_ids[0],
798 };
799
800 struct send_signal_irq_work {
801 struct irq_work irq_work;
802 struct task_struct *task;
803 u32 sig;
804 enum pid_type type;
805 };
806
807 static DEFINE_PER_CPU(struct send_signal_irq_work, send_signal_work);
808
do_bpf_send_signal(struct irq_work * entry)809 static void do_bpf_send_signal(struct irq_work *entry)
810 {
811 struct send_signal_irq_work *work;
812
813 work = container_of(entry, struct send_signal_irq_work, irq_work);
814 group_send_sig_info(work->sig, SEND_SIG_PRIV, work->task, work->type);
815 put_task_struct(work->task);
816 }
817
bpf_send_signal_common(u32 sig,enum pid_type type)818 static int bpf_send_signal_common(u32 sig, enum pid_type type)
819 {
820 struct send_signal_irq_work *work = NULL;
821
822 /* Similar to bpf_probe_write_user, task needs to be
823 * in a sound condition and kernel memory access be
824 * permitted in order to send signal to the current
825 * task.
826 */
827 if (unlikely(current->flags & (PF_KTHREAD | PF_EXITING)))
828 return -EPERM;
829 if (unlikely(!nmi_uaccess_okay()))
830 return -EPERM;
831 /* Task should not be pid=1 to avoid kernel panic. */
832 if (unlikely(is_global_init(current)))
833 return -EPERM;
834
835 if (irqs_disabled()) {
836 /* Do an early check on signal validity. Otherwise,
837 * the error is lost in deferred irq_work.
838 */
839 if (unlikely(!valid_signal(sig)))
840 return -EINVAL;
841
842 work = this_cpu_ptr(&send_signal_work);
843 if (irq_work_is_busy(&work->irq_work))
844 return -EBUSY;
845
846 /* Add the current task, which is the target of sending signal,
847 * to the irq_work. The current task may change when queued
848 * irq works get executed.
849 */
850 work->task = get_task_struct(current);
851 work->sig = sig;
852 work->type = type;
853 irq_work_queue(&work->irq_work);
854 return 0;
855 }
856
857 return group_send_sig_info(sig, SEND_SIG_PRIV, current, type);
858 }
859
BPF_CALL_1(bpf_send_signal,u32,sig)860 BPF_CALL_1(bpf_send_signal, u32, sig)
861 {
862 return bpf_send_signal_common(sig, PIDTYPE_TGID);
863 }
864
865 static const struct bpf_func_proto bpf_send_signal_proto = {
866 .func = bpf_send_signal,
867 .gpl_only = false,
868 .ret_type = RET_INTEGER,
869 .arg1_type = ARG_ANYTHING,
870 };
871
BPF_CALL_1(bpf_send_signal_thread,u32,sig)872 BPF_CALL_1(bpf_send_signal_thread, u32, sig)
873 {
874 return bpf_send_signal_common(sig, PIDTYPE_PID);
875 }
876
877 static const struct bpf_func_proto bpf_send_signal_thread_proto = {
878 .func = bpf_send_signal_thread,
879 .gpl_only = false,
880 .ret_type = RET_INTEGER,
881 .arg1_type = ARG_ANYTHING,
882 };
883
BPF_CALL_3(bpf_d_path,struct path *,path,char *,buf,u32,sz)884 BPF_CALL_3(bpf_d_path, struct path *, path, char *, buf, u32, sz)
885 {
886 struct path copy;
887 long len;
888 char *p;
889
890 if (!sz)
891 return 0;
892
893 /*
894 * The path pointer is verified as trusted and safe to use,
895 * but let's double check it's valid anyway to workaround
896 * potentially broken verifier.
897 */
898 len = copy_from_kernel_nofault(©, path, sizeof(*path));
899 if (len < 0)
900 return len;
901
902 p = d_path(©, buf, sz);
903 if (IS_ERR(p)) {
904 len = PTR_ERR(p);
905 } else {
906 len = buf + sz - p;
907 memmove(buf, p, len);
908 }
909
910 return len;
911 }
912
913 BTF_SET_START(btf_allowlist_d_path)
914 #ifdef CONFIG_SECURITY
BTF_ID(func,security_file_permission)915 BTF_ID(func, security_file_permission)
916 BTF_ID(func, security_inode_getattr)
917 BTF_ID(func, security_file_open)
918 #endif
919 #ifdef CONFIG_SECURITY_PATH
920 BTF_ID(func, security_path_truncate)
921 #endif
922 BTF_ID(func, vfs_truncate)
923 BTF_ID(func, vfs_fallocate)
924 BTF_ID(func, dentry_open)
925 BTF_ID(func, vfs_getattr)
926 BTF_ID(func, filp_close)
927 BTF_SET_END(btf_allowlist_d_path)
928
929 static bool bpf_d_path_allowed(const struct bpf_prog *prog)
930 {
931 if (prog->type == BPF_PROG_TYPE_TRACING &&
932 prog->expected_attach_type == BPF_TRACE_ITER)
933 return true;
934
935 if (prog->type == BPF_PROG_TYPE_LSM)
936 return bpf_lsm_is_sleepable_hook(prog->aux->attach_btf_id);
937
938 return btf_id_set_contains(&btf_allowlist_d_path,
939 prog->aux->attach_btf_id);
940 }
941
942 BTF_ID_LIST_SINGLE(bpf_d_path_btf_ids, struct, path)
943
944 static const struct bpf_func_proto bpf_d_path_proto = {
945 .func = bpf_d_path,
946 .gpl_only = false,
947 .ret_type = RET_INTEGER,
948 .arg1_type = ARG_PTR_TO_BTF_ID,
949 .arg1_btf_id = &bpf_d_path_btf_ids[0],
950 .arg2_type = ARG_PTR_TO_MEM,
951 .arg3_type = ARG_CONST_SIZE_OR_ZERO,
952 .allowed = bpf_d_path_allowed,
953 };
954
955 #define BTF_F_ALL (BTF_F_COMPACT | BTF_F_NONAME | \
956 BTF_F_PTR_RAW | BTF_F_ZERO)
957
bpf_btf_printf_prepare(struct btf_ptr * ptr,u32 btf_ptr_size,u64 flags,const struct btf ** btf,s32 * btf_id)958 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size,
959 u64 flags, const struct btf **btf,
960 s32 *btf_id)
961 {
962 const struct btf_type *t;
963
964 if (unlikely(flags & ~(BTF_F_ALL)))
965 return -EINVAL;
966
967 if (btf_ptr_size != sizeof(struct btf_ptr))
968 return -EINVAL;
969
970 *btf = bpf_get_btf_vmlinux();
971
972 if (IS_ERR_OR_NULL(*btf))
973 return IS_ERR(*btf) ? PTR_ERR(*btf) : -EINVAL;
974
975 if (ptr->type_id > 0)
976 *btf_id = ptr->type_id;
977 else
978 return -EINVAL;
979
980 if (*btf_id > 0)
981 t = btf_type_by_id(*btf, *btf_id);
982 if (*btf_id <= 0 || !t)
983 return -ENOENT;
984
985 return 0;
986 }
987
BPF_CALL_5(bpf_snprintf_btf,char *,str,u32,str_size,struct btf_ptr *,ptr,u32,btf_ptr_size,u64,flags)988 BPF_CALL_5(bpf_snprintf_btf, char *, str, u32, str_size, struct btf_ptr *, ptr,
989 u32, btf_ptr_size, u64, flags)
990 {
991 const struct btf *btf;
992 s32 btf_id;
993 int ret;
994
995 ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id);
996 if (ret)
997 return ret;
998
999 return btf_type_snprintf_show(btf, btf_id, ptr->ptr, str, str_size,
1000 flags);
1001 }
1002
1003 const struct bpf_func_proto bpf_snprintf_btf_proto = {
1004 .func = bpf_snprintf_btf,
1005 .gpl_only = false,
1006 .ret_type = RET_INTEGER,
1007 .arg1_type = ARG_PTR_TO_MEM,
1008 .arg2_type = ARG_CONST_SIZE,
1009 .arg3_type = ARG_PTR_TO_MEM | MEM_RDONLY,
1010 .arg4_type = ARG_CONST_SIZE,
1011 .arg5_type = ARG_ANYTHING,
1012 };
1013
BPF_CALL_1(bpf_get_func_ip_tracing,void *,ctx)1014 BPF_CALL_1(bpf_get_func_ip_tracing, void *, ctx)
1015 {
1016 /* This helper call is inlined by verifier. */
1017 return ((u64 *)ctx)[-2];
1018 }
1019
1020 static const struct bpf_func_proto bpf_get_func_ip_proto_tracing = {
1021 .func = bpf_get_func_ip_tracing,
1022 .gpl_only = true,
1023 .ret_type = RET_INTEGER,
1024 .arg1_type = ARG_PTR_TO_CTX,
1025 };
1026
1027 #ifdef CONFIG_X86_KERNEL_IBT
get_entry_ip(unsigned long fentry_ip)1028 static unsigned long get_entry_ip(unsigned long fentry_ip)
1029 {
1030 u32 instr;
1031
1032 /* We want to be extra safe in case entry ip is on the page edge,
1033 * but otherwise we need to avoid get_kernel_nofault()'s overhead.
1034 */
1035 if ((fentry_ip & ~PAGE_MASK) < ENDBR_INSN_SIZE) {
1036 if (get_kernel_nofault(instr, (u32 *)(fentry_ip - ENDBR_INSN_SIZE)))
1037 return fentry_ip;
1038 } else {
1039 instr = *(u32 *)(fentry_ip - ENDBR_INSN_SIZE);
1040 }
1041 if (is_endbr(instr))
1042 fentry_ip -= ENDBR_INSN_SIZE;
1043 return fentry_ip;
1044 }
1045 #else
1046 #define get_entry_ip(fentry_ip) fentry_ip
1047 #endif
1048
BPF_CALL_1(bpf_get_func_ip_kprobe,struct pt_regs *,regs)1049 BPF_CALL_1(bpf_get_func_ip_kprobe, struct pt_regs *, regs)
1050 {
1051 struct bpf_trace_run_ctx *run_ctx __maybe_unused;
1052 struct kprobe *kp;
1053
1054 #ifdef CONFIG_UPROBES
1055 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx);
1056 if (run_ctx->is_uprobe)
1057 return ((struct uprobe_dispatch_data *)current->utask->vaddr)->bp_addr;
1058 #endif
1059
1060 kp = kprobe_running();
1061
1062 if (!kp || !(kp->flags & KPROBE_FLAG_ON_FUNC_ENTRY))
1063 return 0;
1064
1065 return get_entry_ip((uintptr_t)kp->addr);
1066 }
1067
1068 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe = {
1069 .func = bpf_get_func_ip_kprobe,
1070 .gpl_only = true,
1071 .ret_type = RET_INTEGER,
1072 .arg1_type = ARG_PTR_TO_CTX,
1073 };
1074
BPF_CALL_1(bpf_get_func_ip_kprobe_multi,struct pt_regs *,regs)1075 BPF_CALL_1(bpf_get_func_ip_kprobe_multi, struct pt_regs *, regs)
1076 {
1077 return bpf_kprobe_multi_entry_ip(current->bpf_ctx);
1078 }
1079
1080 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe_multi = {
1081 .func = bpf_get_func_ip_kprobe_multi,
1082 .gpl_only = false,
1083 .ret_type = RET_INTEGER,
1084 .arg1_type = ARG_PTR_TO_CTX,
1085 };
1086
BPF_CALL_1(bpf_get_attach_cookie_kprobe_multi,struct pt_regs *,regs)1087 BPF_CALL_1(bpf_get_attach_cookie_kprobe_multi, struct pt_regs *, regs)
1088 {
1089 return bpf_kprobe_multi_cookie(current->bpf_ctx);
1090 }
1091
1092 static const struct bpf_func_proto bpf_get_attach_cookie_proto_kmulti = {
1093 .func = bpf_get_attach_cookie_kprobe_multi,
1094 .gpl_only = false,
1095 .ret_type = RET_INTEGER,
1096 .arg1_type = ARG_PTR_TO_CTX,
1097 };
1098
BPF_CALL_1(bpf_get_func_ip_uprobe_multi,struct pt_regs *,regs)1099 BPF_CALL_1(bpf_get_func_ip_uprobe_multi, struct pt_regs *, regs)
1100 {
1101 return bpf_uprobe_multi_entry_ip(current->bpf_ctx);
1102 }
1103
1104 static const struct bpf_func_proto bpf_get_func_ip_proto_uprobe_multi = {
1105 .func = bpf_get_func_ip_uprobe_multi,
1106 .gpl_only = false,
1107 .ret_type = RET_INTEGER,
1108 .arg1_type = ARG_PTR_TO_CTX,
1109 };
1110
BPF_CALL_1(bpf_get_attach_cookie_uprobe_multi,struct pt_regs *,regs)1111 BPF_CALL_1(bpf_get_attach_cookie_uprobe_multi, struct pt_regs *, regs)
1112 {
1113 return bpf_uprobe_multi_cookie(current->bpf_ctx);
1114 }
1115
1116 static const struct bpf_func_proto bpf_get_attach_cookie_proto_umulti = {
1117 .func = bpf_get_attach_cookie_uprobe_multi,
1118 .gpl_only = false,
1119 .ret_type = RET_INTEGER,
1120 .arg1_type = ARG_PTR_TO_CTX,
1121 };
1122
BPF_CALL_1(bpf_get_attach_cookie_trace,void *,ctx)1123 BPF_CALL_1(bpf_get_attach_cookie_trace, void *, ctx)
1124 {
1125 struct bpf_trace_run_ctx *run_ctx;
1126
1127 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx);
1128 return run_ctx->bpf_cookie;
1129 }
1130
1131 static const struct bpf_func_proto bpf_get_attach_cookie_proto_trace = {
1132 .func = bpf_get_attach_cookie_trace,
1133 .gpl_only = false,
1134 .ret_type = RET_INTEGER,
1135 .arg1_type = ARG_PTR_TO_CTX,
1136 };
1137
BPF_CALL_1(bpf_get_attach_cookie_pe,struct bpf_perf_event_data_kern *,ctx)1138 BPF_CALL_1(bpf_get_attach_cookie_pe, struct bpf_perf_event_data_kern *, ctx)
1139 {
1140 return ctx->event->bpf_cookie;
1141 }
1142
1143 static const struct bpf_func_proto bpf_get_attach_cookie_proto_pe = {
1144 .func = bpf_get_attach_cookie_pe,
1145 .gpl_only = false,
1146 .ret_type = RET_INTEGER,
1147 .arg1_type = ARG_PTR_TO_CTX,
1148 };
1149
BPF_CALL_1(bpf_get_attach_cookie_tracing,void *,ctx)1150 BPF_CALL_1(bpf_get_attach_cookie_tracing, void *, ctx)
1151 {
1152 struct bpf_trace_run_ctx *run_ctx;
1153
1154 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx);
1155 return run_ctx->bpf_cookie;
1156 }
1157
1158 static const struct bpf_func_proto bpf_get_attach_cookie_proto_tracing = {
1159 .func = bpf_get_attach_cookie_tracing,
1160 .gpl_only = false,
1161 .ret_type = RET_INTEGER,
1162 .arg1_type = ARG_PTR_TO_CTX,
1163 };
1164
BPF_CALL_3(bpf_get_branch_snapshot,void *,buf,u32,size,u64,flags)1165 BPF_CALL_3(bpf_get_branch_snapshot, void *, buf, u32, size, u64, flags)
1166 {
1167 static const u32 br_entry_size = sizeof(struct perf_branch_entry);
1168 u32 entry_cnt = size / br_entry_size;
1169
1170 entry_cnt = static_call(perf_snapshot_branch_stack)(buf, entry_cnt);
1171
1172 if (unlikely(flags))
1173 return -EINVAL;
1174
1175 if (!entry_cnt)
1176 return -ENOENT;
1177
1178 return entry_cnt * br_entry_size;
1179 }
1180
1181 static const struct bpf_func_proto bpf_get_branch_snapshot_proto = {
1182 .func = bpf_get_branch_snapshot,
1183 .gpl_only = true,
1184 .ret_type = RET_INTEGER,
1185 .arg1_type = ARG_PTR_TO_UNINIT_MEM,
1186 .arg2_type = ARG_CONST_SIZE_OR_ZERO,
1187 };
1188
BPF_CALL_3(get_func_arg,void *,ctx,u32,n,u64 *,value)1189 BPF_CALL_3(get_func_arg, void *, ctx, u32, n, u64 *, value)
1190 {
1191 /* This helper call is inlined by verifier. */
1192 u64 nr_args = ((u64 *)ctx)[-1];
1193
1194 if ((u64) n >= nr_args)
1195 return -EINVAL;
1196 *value = ((u64 *)ctx)[n];
1197 return 0;
1198 }
1199
1200 static const struct bpf_func_proto bpf_get_func_arg_proto = {
1201 .func = get_func_arg,
1202 .ret_type = RET_INTEGER,
1203 .arg1_type = ARG_PTR_TO_CTX,
1204 .arg2_type = ARG_ANYTHING,
1205 .arg3_type = ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED,
1206 .arg3_size = sizeof(u64),
1207 };
1208
BPF_CALL_2(get_func_ret,void *,ctx,u64 *,value)1209 BPF_CALL_2(get_func_ret, void *, ctx, u64 *, value)
1210 {
1211 /* This helper call is inlined by verifier. */
1212 u64 nr_args = ((u64 *)ctx)[-1];
1213
1214 *value = ((u64 *)ctx)[nr_args];
1215 return 0;
1216 }
1217
1218 static const struct bpf_func_proto bpf_get_func_ret_proto = {
1219 .func = get_func_ret,
1220 .ret_type = RET_INTEGER,
1221 .arg1_type = ARG_PTR_TO_CTX,
1222 .arg2_type = ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED,
1223 .arg2_size = sizeof(u64),
1224 };
1225
BPF_CALL_1(get_func_arg_cnt,void *,ctx)1226 BPF_CALL_1(get_func_arg_cnt, void *, ctx)
1227 {
1228 /* This helper call is inlined by verifier. */
1229 return ((u64 *)ctx)[-1];
1230 }
1231
1232 static const struct bpf_func_proto bpf_get_func_arg_cnt_proto = {
1233 .func = get_func_arg_cnt,
1234 .ret_type = RET_INTEGER,
1235 .arg1_type = ARG_PTR_TO_CTX,
1236 };
1237
1238 #ifdef CONFIG_KEYS
1239 __bpf_kfunc_start_defs();
1240
1241 /**
1242 * bpf_lookup_user_key - lookup a key by its serial
1243 * @serial: key handle serial number
1244 * @flags: lookup-specific flags
1245 *
1246 * Search a key with a given *serial* and the provided *flags*.
1247 * If found, increment the reference count of the key by one, and
1248 * return it in the bpf_key structure.
1249 *
1250 * The bpf_key structure must be passed to bpf_key_put() when done
1251 * with it, so that the key reference count is decremented and the
1252 * bpf_key structure is freed.
1253 *
1254 * Permission checks are deferred to the time the key is used by
1255 * one of the available key-specific kfuncs.
1256 *
1257 * Set *flags* with KEY_LOOKUP_CREATE, to attempt creating a requested
1258 * special keyring (e.g. session keyring), if it doesn't yet exist.
1259 * Set *flags* with KEY_LOOKUP_PARTIAL, to lookup a key without waiting
1260 * for the key construction, and to retrieve uninstantiated keys (keys
1261 * without data attached to them).
1262 *
1263 * Return: a bpf_key pointer with a valid key pointer if the key is found, a
1264 * NULL pointer otherwise.
1265 */
bpf_lookup_user_key(u32 serial,u64 flags)1266 __bpf_kfunc struct bpf_key *bpf_lookup_user_key(u32 serial, u64 flags)
1267 {
1268 key_ref_t key_ref;
1269 struct bpf_key *bkey;
1270
1271 if (flags & ~KEY_LOOKUP_ALL)
1272 return NULL;
1273
1274 /*
1275 * Permission check is deferred until the key is used, as the
1276 * intent of the caller is unknown here.
1277 */
1278 key_ref = lookup_user_key(serial, flags, KEY_DEFER_PERM_CHECK);
1279 if (IS_ERR(key_ref))
1280 return NULL;
1281
1282 bkey = kmalloc(sizeof(*bkey), GFP_KERNEL);
1283 if (!bkey) {
1284 key_put(key_ref_to_ptr(key_ref));
1285 return NULL;
1286 }
1287
1288 bkey->key = key_ref_to_ptr(key_ref);
1289 bkey->has_ref = true;
1290
1291 return bkey;
1292 }
1293
1294 /**
1295 * bpf_lookup_system_key - lookup a key by a system-defined ID
1296 * @id: key ID
1297 *
1298 * Obtain a bpf_key structure with a key pointer set to the passed key ID.
1299 * The key pointer is marked as invalid, to prevent bpf_key_put() from
1300 * attempting to decrement the key reference count on that pointer. The key
1301 * pointer set in such way is currently understood only by
1302 * verify_pkcs7_signature().
1303 *
1304 * Set *id* to one of the values defined in include/linux/verification.h:
1305 * 0 for the primary keyring (immutable keyring of system keys);
1306 * VERIFY_USE_SECONDARY_KEYRING for both the primary and secondary keyring
1307 * (where keys can be added only if they are vouched for by existing keys
1308 * in those keyrings); VERIFY_USE_PLATFORM_KEYRING for the platform
1309 * keyring (primarily used by the integrity subsystem to verify a kexec'ed
1310 * kerned image and, possibly, the initramfs signature).
1311 *
1312 * Return: a bpf_key pointer with an invalid key pointer set from the
1313 * pre-determined ID on success, a NULL pointer otherwise
1314 */
bpf_lookup_system_key(u64 id)1315 __bpf_kfunc struct bpf_key *bpf_lookup_system_key(u64 id)
1316 {
1317 struct bpf_key *bkey;
1318
1319 if (system_keyring_id_check(id) < 0)
1320 return NULL;
1321
1322 bkey = kmalloc(sizeof(*bkey), GFP_ATOMIC);
1323 if (!bkey)
1324 return NULL;
1325
1326 bkey->key = (struct key *)(unsigned long)id;
1327 bkey->has_ref = false;
1328
1329 return bkey;
1330 }
1331
1332 /**
1333 * bpf_key_put - decrement key reference count if key is valid and free bpf_key
1334 * @bkey: bpf_key structure
1335 *
1336 * Decrement the reference count of the key inside *bkey*, if the pointer
1337 * is valid, and free *bkey*.
1338 */
bpf_key_put(struct bpf_key * bkey)1339 __bpf_kfunc void bpf_key_put(struct bpf_key *bkey)
1340 {
1341 if (bkey->has_ref)
1342 key_put(bkey->key);
1343
1344 kfree(bkey);
1345 }
1346
1347 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION
1348 /**
1349 * bpf_verify_pkcs7_signature - verify a PKCS#7 signature
1350 * @data_p: data to verify
1351 * @sig_p: signature of the data
1352 * @trusted_keyring: keyring with keys trusted for signature verification
1353 *
1354 * Verify the PKCS#7 signature *sig_ptr* against the supplied *data_ptr*
1355 * with keys in a keyring referenced by *trusted_keyring*.
1356 *
1357 * Return: 0 on success, a negative value on error.
1358 */
bpf_verify_pkcs7_signature(struct bpf_dynptr * data_p,struct bpf_dynptr * sig_p,struct bpf_key * trusted_keyring)1359 __bpf_kfunc int bpf_verify_pkcs7_signature(struct bpf_dynptr *data_p,
1360 struct bpf_dynptr *sig_p,
1361 struct bpf_key *trusted_keyring)
1362 {
1363 struct bpf_dynptr_kern *data_ptr = (struct bpf_dynptr_kern *)data_p;
1364 struct bpf_dynptr_kern *sig_ptr = (struct bpf_dynptr_kern *)sig_p;
1365 const void *data, *sig;
1366 u32 data_len, sig_len;
1367 int ret;
1368
1369 if (trusted_keyring->has_ref) {
1370 /*
1371 * Do the permission check deferred in bpf_lookup_user_key().
1372 * See bpf_lookup_user_key() for more details.
1373 *
1374 * A call to key_task_permission() here would be redundant, as
1375 * it is already done by keyring_search() called by
1376 * find_asymmetric_key().
1377 */
1378 ret = key_validate(trusted_keyring->key);
1379 if (ret < 0)
1380 return ret;
1381 }
1382
1383 data_len = __bpf_dynptr_size(data_ptr);
1384 data = __bpf_dynptr_data(data_ptr, data_len);
1385 sig_len = __bpf_dynptr_size(sig_ptr);
1386 sig = __bpf_dynptr_data(sig_ptr, sig_len);
1387
1388 return verify_pkcs7_signature(data, data_len, sig, sig_len,
1389 trusted_keyring->key,
1390 VERIFYING_UNSPECIFIED_SIGNATURE, NULL,
1391 NULL);
1392 }
1393 #endif /* CONFIG_SYSTEM_DATA_VERIFICATION */
1394
1395 __bpf_kfunc_end_defs();
1396
1397 BTF_KFUNCS_START(key_sig_kfunc_set)
1398 BTF_ID_FLAGS(func, bpf_lookup_user_key, KF_ACQUIRE | KF_RET_NULL | KF_SLEEPABLE)
1399 BTF_ID_FLAGS(func, bpf_lookup_system_key, KF_ACQUIRE | KF_RET_NULL)
1400 BTF_ID_FLAGS(func, bpf_key_put, KF_RELEASE)
1401 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION
1402 BTF_ID_FLAGS(func, bpf_verify_pkcs7_signature, KF_SLEEPABLE)
1403 #endif
1404 BTF_KFUNCS_END(key_sig_kfunc_set)
1405
1406 static const struct btf_kfunc_id_set bpf_key_sig_kfunc_set = {
1407 .owner = THIS_MODULE,
1408 .set = &key_sig_kfunc_set,
1409 };
1410
bpf_key_sig_kfuncs_init(void)1411 static int __init bpf_key_sig_kfuncs_init(void)
1412 {
1413 return register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING,
1414 &bpf_key_sig_kfunc_set);
1415 }
1416
1417 late_initcall(bpf_key_sig_kfuncs_init);
1418 #endif /* CONFIG_KEYS */
1419
1420 static const struct bpf_func_proto *
bpf_tracing_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1421 bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1422 {
1423 switch (func_id) {
1424 case BPF_FUNC_map_lookup_elem:
1425 return &bpf_map_lookup_elem_proto;
1426 case BPF_FUNC_map_update_elem:
1427 return &bpf_map_update_elem_proto;
1428 case BPF_FUNC_map_delete_elem:
1429 return &bpf_map_delete_elem_proto;
1430 case BPF_FUNC_map_push_elem:
1431 return &bpf_map_push_elem_proto;
1432 case BPF_FUNC_map_pop_elem:
1433 return &bpf_map_pop_elem_proto;
1434 case BPF_FUNC_map_peek_elem:
1435 return &bpf_map_peek_elem_proto;
1436 case BPF_FUNC_map_lookup_percpu_elem:
1437 return &bpf_map_lookup_percpu_elem_proto;
1438 case BPF_FUNC_ktime_get_ns:
1439 return &bpf_ktime_get_ns_proto;
1440 case BPF_FUNC_ktime_get_boot_ns:
1441 return &bpf_ktime_get_boot_ns_proto;
1442 case BPF_FUNC_tail_call:
1443 return &bpf_tail_call_proto;
1444 case BPF_FUNC_get_current_task:
1445 return &bpf_get_current_task_proto;
1446 case BPF_FUNC_get_current_task_btf:
1447 return &bpf_get_current_task_btf_proto;
1448 case BPF_FUNC_task_pt_regs:
1449 return &bpf_task_pt_regs_proto;
1450 case BPF_FUNC_get_current_uid_gid:
1451 return &bpf_get_current_uid_gid_proto;
1452 case BPF_FUNC_get_current_comm:
1453 return &bpf_get_current_comm_proto;
1454 case BPF_FUNC_trace_printk:
1455 return bpf_get_trace_printk_proto();
1456 case BPF_FUNC_get_smp_processor_id:
1457 return &bpf_get_smp_processor_id_proto;
1458 case BPF_FUNC_get_numa_node_id:
1459 return &bpf_get_numa_node_id_proto;
1460 case BPF_FUNC_perf_event_read:
1461 return &bpf_perf_event_read_proto;
1462 case BPF_FUNC_get_prandom_u32:
1463 return &bpf_get_prandom_u32_proto;
1464 case BPF_FUNC_probe_write_user:
1465 return security_locked_down(LOCKDOWN_BPF_WRITE_USER) < 0 ?
1466 NULL : bpf_get_probe_write_proto();
1467 case BPF_FUNC_probe_read_user:
1468 return &bpf_probe_read_user_proto;
1469 case BPF_FUNC_probe_read_kernel:
1470 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
1471 NULL : &bpf_probe_read_kernel_proto;
1472 case BPF_FUNC_probe_read_user_str:
1473 return &bpf_probe_read_user_str_proto;
1474 case BPF_FUNC_probe_read_kernel_str:
1475 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
1476 NULL : &bpf_probe_read_kernel_str_proto;
1477 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
1478 case BPF_FUNC_probe_read:
1479 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
1480 NULL : &bpf_probe_read_compat_proto;
1481 case BPF_FUNC_probe_read_str:
1482 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
1483 NULL : &bpf_probe_read_compat_str_proto;
1484 #endif
1485 #ifdef CONFIG_CGROUPS
1486 case BPF_FUNC_cgrp_storage_get:
1487 return &bpf_cgrp_storage_get_proto;
1488 case BPF_FUNC_cgrp_storage_delete:
1489 return &bpf_cgrp_storage_delete_proto;
1490 case BPF_FUNC_current_task_under_cgroup:
1491 return &bpf_current_task_under_cgroup_proto;
1492 #endif
1493 case BPF_FUNC_send_signal:
1494 return &bpf_send_signal_proto;
1495 case BPF_FUNC_send_signal_thread:
1496 return &bpf_send_signal_thread_proto;
1497 case BPF_FUNC_perf_event_read_value:
1498 return &bpf_perf_event_read_value_proto;
1499 case BPF_FUNC_ringbuf_output:
1500 return &bpf_ringbuf_output_proto;
1501 case BPF_FUNC_ringbuf_reserve:
1502 return &bpf_ringbuf_reserve_proto;
1503 case BPF_FUNC_ringbuf_submit:
1504 return &bpf_ringbuf_submit_proto;
1505 case BPF_FUNC_ringbuf_discard:
1506 return &bpf_ringbuf_discard_proto;
1507 case BPF_FUNC_ringbuf_query:
1508 return &bpf_ringbuf_query_proto;
1509 case BPF_FUNC_jiffies64:
1510 return &bpf_jiffies64_proto;
1511 case BPF_FUNC_get_task_stack:
1512 return prog->sleepable ? &bpf_get_task_stack_sleepable_proto
1513 : &bpf_get_task_stack_proto;
1514 case BPF_FUNC_copy_from_user:
1515 return &bpf_copy_from_user_proto;
1516 case BPF_FUNC_copy_from_user_task:
1517 return &bpf_copy_from_user_task_proto;
1518 case BPF_FUNC_snprintf_btf:
1519 return &bpf_snprintf_btf_proto;
1520 case BPF_FUNC_per_cpu_ptr:
1521 return &bpf_per_cpu_ptr_proto;
1522 case BPF_FUNC_this_cpu_ptr:
1523 return &bpf_this_cpu_ptr_proto;
1524 case BPF_FUNC_task_storage_get:
1525 if (bpf_prog_check_recur(prog))
1526 return &bpf_task_storage_get_recur_proto;
1527 return &bpf_task_storage_get_proto;
1528 case BPF_FUNC_task_storage_delete:
1529 if (bpf_prog_check_recur(prog))
1530 return &bpf_task_storage_delete_recur_proto;
1531 return &bpf_task_storage_delete_proto;
1532 case BPF_FUNC_for_each_map_elem:
1533 return &bpf_for_each_map_elem_proto;
1534 case BPF_FUNC_snprintf:
1535 return &bpf_snprintf_proto;
1536 case BPF_FUNC_get_func_ip:
1537 return &bpf_get_func_ip_proto_tracing;
1538 case BPF_FUNC_get_branch_snapshot:
1539 return &bpf_get_branch_snapshot_proto;
1540 case BPF_FUNC_find_vma:
1541 return &bpf_find_vma_proto;
1542 case BPF_FUNC_trace_vprintk:
1543 return bpf_get_trace_vprintk_proto();
1544 default:
1545 return bpf_base_func_proto(func_id, prog);
1546 }
1547 }
1548
is_kprobe_multi(const struct bpf_prog * prog)1549 static bool is_kprobe_multi(const struct bpf_prog *prog)
1550 {
1551 return prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI ||
1552 prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION;
1553 }
1554
is_kprobe_session(const struct bpf_prog * prog)1555 static inline bool is_kprobe_session(const struct bpf_prog *prog)
1556 {
1557 return prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION;
1558 }
1559
1560 static const struct bpf_func_proto *
kprobe_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1561 kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1562 {
1563 switch (func_id) {
1564 case BPF_FUNC_perf_event_output:
1565 return &bpf_perf_event_output_proto;
1566 case BPF_FUNC_get_stackid:
1567 return &bpf_get_stackid_proto;
1568 case BPF_FUNC_get_stack:
1569 return prog->sleepable ? &bpf_get_stack_sleepable_proto : &bpf_get_stack_proto;
1570 #ifdef CONFIG_BPF_KPROBE_OVERRIDE
1571 case BPF_FUNC_override_return:
1572 return &bpf_override_return_proto;
1573 #endif
1574 case BPF_FUNC_get_func_ip:
1575 if (is_kprobe_multi(prog))
1576 return &bpf_get_func_ip_proto_kprobe_multi;
1577 if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI)
1578 return &bpf_get_func_ip_proto_uprobe_multi;
1579 return &bpf_get_func_ip_proto_kprobe;
1580 case BPF_FUNC_get_attach_cookie:
1581 if (is_kprobe_multi(prog))
1582 return &bpf_get_attach_cookie_proto_kmulti;
1583 if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI)
1584 return &bpf_get_attach_cookie_proto_umulti;
1585 return &bpf_get_attach_cookie_proto_trace;
1586 default:
1587 return bpf_tracing_func_proto(func_id, prog);
1588 }
1589 }
1590
1591 /* bpf+kprobe programs can access fields of 'struct pt_regs' */
kprobe_prog_is_valid_access(int off,int size,enum bpf_access_type type,const struct bpf_prog * prog,struct bpf_insn_access_aux * info)1592 static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
1593 const struct bpf_prog *prog,
1594 struct bpf_insn_access_aux *info)
1595 {
1596 if (off < 0 || off >= sizeof(struct pt_regs))
1597 return false;
1598 if (type != BPF_READ)
1599 return false;
1600 if (off % size != 0)
1601 return false;
1602 /*
1603 * Assertion for 32 bit to make sure last 8 byte access
1604 * (BPF_DW) to the last 4 byte member is disallowed.
1605 */
1606 if (off + size > sizeof(struct pt_regs))
1607 return false;
1608
1609 return true;
1610 }
1611
1612 const struct bpf_verifier_ops kprobe_verifier_ops = {
1613 .get_func_proto = kprobe_prog_func_proto,
1614 .is_valid_access = kprobe_prog_is_valid_access,
1615 };
1616
1617 const struct bpf_prog_ops kprobe_prog_ops = {
1618 };
1619
BPF_CALL_5(bpf_perf_event_output_tp,void *,tp_buff,struct bpf_map *,map,u64,flags,void *,data,u64,size)1620 BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map,
1621 u64, flags, void *, data, u64, size)
1622 {
1623 struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1624
1625 /*
1626 * r1 points to perf tracepoint buffer where first 8 bytes are hidden
1627 * from bpf program and contain a pointer to 'struct pt_regs'. Fetch it
1628 * from there and call the same bpf_perf_event_output() helper inline.
1629 */
1630 return ____bpf_perf_event_output(regs, map, flags, data, size);
1631 }
1632
1633 static const struct bpf_func_proto bpf_perf_event_output_proto_tp = {
1634 .func = bpf_perf_event_output_tp,
1635 .gpl_only = true,
1636 .ret_type = RET_INTEGER,
1637 .arg1_type = ARG_PTR_TO_CTX,
1638 .arg2_type = ARG_CONST_MAP_PTR,
1639 .arg3_type = ARG_ANYTHING,
1640 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY,
1641 .arg5_type = ARG_CONST_SIZE_OR_ZERO,
1642 };
1643
BPF_CALL_3(bpf_get_stackid_tp,void *,tp_buff,struct bpf_map *,map,u64,flags)1644 BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map,
1645 u64, flags)
1646 {
1647 struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1648
1649 /*
1650 * Same comment as in bpf_perf_event_output_tp(), only that this time
1651 * the other helper's function body cannot be inlined due to being
1652 * external, thus we need to call raw helper function.
1653 */
1654 return bpf_get_stackid((unsigned long) regs, (unsigned long) map,
1655 flags, 0, 0);
1656 }
1657
1658 static const struct bpf_func_proto bpf_get_stackid_proto_tp = {
1659 .func = bpf_get_stackid_tp,
1660 .gpl_only = true,
1661 .ret_type = RET_INTEGER,
1662 .arg1_type = ARG_PTR_TO_CTX,
1663 .arg2_type = ARG_CONST_MAP_PTR,
1664 .arg3_type = ARG_ANYTHING,
1665 };
1666
BPF_CALL_4(bpf_get_stack_tp,void *,tp_buff,void *,buf,u32,size,u64,flags)1667 BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size,
1668 u64, flags)
1669 {
1670 struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1671
1672 return bpf_get_stack((unsigned long) regs, (unsigned long) buf,
1673 (unsigned long) size, flags, 0);
1674 }
1675
1676 static const struct bpf_func_proto bpf_get_stack_proto_tp = {
1677 .func = bpf_get_stack_tp,
1678 .gpl_only = true,
1679 .ret_type = RET_INTEGER,
1680 .arg1_type = ARG_PTR_TO_CTX,
1681 .arg2_type = ARG_PTR_TO_UNINIT_MEM,
1682 .arg3_type = ARG_CONST_SIZE_OR_ZERO,
1683 .arg4_type = ARG_ANYTHING,
1684 };
1685
1686 static const struct bpf_func_proto *
tp_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1687 tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1688 {
1689 switch (func_id) {
1690 case BPF_FUNC_perf_event_output:
1691 return &bpf_perf_event_output_proto_tp;
1692 case BPF_FUNC_get_stackid:
1693 return &bpf_get_stackid_proto_tp;
1694 case BPF_FUNC_get_stack:
1695 return &bpf_get_stack_proto_tp;
1696 case BPF_FUNC_get_attach_cookie:
1697 return &bpf_get_attach_cookie_proto_trace;
1698 default:
1699 return bpf_tracing_func_proto(func_id, prog);
1700 }
1701 }
1702
tp_prog_is_valid_access(int off,int size,enum bpf_access_type type,const struct bpf_prog * prog,struct bpf_insn_access_aux * info)1703 static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type,
1704 const struct bpf_prog *prog,
1705 struct bpf_insn_access_aux *info)
1706 {
1707 if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE)
1708 return false;
1709 if (type != BPF_READ)
1710 return false;
1711 if (off % size != 0)
1712 return false;
1713
1714 BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(__u64));
1715 return true;
1716 }
1717
1718 const struct bpf_verifier_ops tracepoint_verifier_ops = {
1719 .get_func_proto = tp_prog_func_proto,
1720 .is_valid_access = tp_prog_is_valid_access,
1721 };
1722
1723 const struct bpf_prog_ops tracepoint_prog_ops = {
1724 };
1725
BPF_CALL_3(bpf_perf_prog_read_value,struct bpf_perf_event_data_kern *,ctx,struct bpf_perf_event_value *,buf,u32,size)1726 BPF_CALL_3(bpf_perf_prog_read_value, struct bpf_perf_event_data_kern *, ctx,
1727 struct bpf_perf_event_value *, buf, u32, size)
1728 {
1729 int err = -EINVAL;
1730
1731 if (unlikely(size != sizeof(struct bpf_perf_event_value)))
1732 goto clear;
1733 err = perf_event_read_local(ctx->event, &buf->counter, &buf->enabled,
1734 &buf->running);
1735 if (unlikely(err))
1736 goto clear;
1737 return 0;
1738 clear:
1739 memset(buf, 0, size);
1740 return err;
1741 }
1742
1743 static const struct bpf_func_proto bpf_perf_prog_read_value_proto = {
1744 .func = bpf_perf_prog_read_value,
1745 .gpl_only = true,
1746 .ret_type = RET_INTEGER,
1747 .arg1_type = ARG_PTR_TO_CTX,
1748 .arg2_type = ARG_PTR_TO_UNINIT_MEM,
1749 .arg3_type = ARG_CONST_SIZE,
1750 };
1751
BPF_CALL_4(bpf_read_branch_records,struct bpf_perf_event_data_kern *,ctx,void *,buf,u32,size,u64,flags)1752 BPF_CALL_4(bpf_read_branch_records, struct bpf_perf_event_data_kern *, ctx,
1753 void *, buf, u32, size, u64, flags)
1754 {
1755 static const u32 br_entry_size = sizeof(struct perf_branch_entry);
1756 struct perf_branch_stack *br_stack = ctx->data->br_stack;
1757 u32 to_copy;
1758
1759 if (unlikely(flags & ~BPF_F_GET_BRANCH_RECORDS_SIZE))
1760 return -EINVAL;
1761
1762 if (unlikely(!(ctx->data->sample_flags & PERF_SAMPLE_BRANCH_STACK)))
1763 return -ENOENT;
1764
1765 if (unlikely(!br_stack))
1766 return -ENOENT;
1767
1768 if (flags & BPF_F_GET_BRANCH_RECORDS_SIZE)
1769 return br_stack->nr * br_entry_size;
1770
1771 if (!buf || (size % br_entry_size != 0))
1772 return -EINVAL;
1773
1774 to_copy = min_t(u32, br_stack->nr * br_entry_size, size);
1775 memcpy(buf, br_stack->entries, to_copy);
1776
1777 return to_copy;
1778 }
1779
1780 static const struct bpf_func_proto bpf_read_branch_records_proto = {
1781 .func = bpf_read_branch_records,
1782 .gpl_only = true,
1783 .ret_type = RET_INTEGER,
1784 .arg1_type = ARG_PTR_TO_CTX,
1785 .arg2_type = ARG_PTR_TO_MEM_OR_NULL,
1786 .arg3_type = ARG_CONST_SIZE_OR_ZERO,
1787 .arg4_type = ARG_ANYTHING,
1788 };
1789
1790 static const struct bpf_func_proto *
pe_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1791 pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1792 {
1793 switch (func_id) {
1794 case BPF_FUNC_perf_event_output:
1795 return &bpf_perf_event_output_proto_tp;
1796 case BPF_FUNC_get_stackid:
1797 return &bpf_get_stackid_proto_pe;
1798 case BPF_FUNC_get_stack:
1799 return &bpf_get_stack_proto_pe;
1800 case BPF_FUNC_perf_prog_read_value:
1801 return &bpf_perf_prog_read_value_proto;
1802 case BPF_FUNC_read_branch_records:
1803 return &bpf_read_branch_records_proto;
1804 case BPF_FUNC_get_attach_cookie:
1805 return &bpf_get_attach_cookie_proto_pe;
1806 default:
1807 return bpf_tracing_func_proto(func_id, prog);
1808 }
1809 }
1810
1811 /*
1812 * bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp
1813 * to avoid potential recursive reuse issue when/if tracepoints are added
1814 * inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack.
1815 *
1816 * Since raw tracepoints run despite bpf_prog_active, support concurrent usage
1817 * in normal, irq, and nmi context.
1818 */
1819 struct bpf_raw_tp_regs {
1820 struct pt_regs regs[3];
1821 };
1822 static DEFINE_PER_CPU(struct bpf_raw_tp_regs, bpf_raw_tp_regs);
1823 static DEFINE_PER_CPU(int, bpf_raw_tp_nest_level);
get_bpf_raw_tp_regs(void)1824 static struct pt_regs *get_bpf_raw_tp_regs(void)
1825 {
1826 struct bpf_raw_tp_regs *tp_regs = this_cpu_ptr(&bpf_raw_tp_regs);
1827 int nest_level = this_cpu_inc_return(bpf_raw_tp_nest_level);
1828
1829 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(tp_regs->regs))) {
1830 this_cpu_dec(bpf_raw_tp_nest_level);
1831 return ERR_PTR(-EBUSY);
1832 }
1833
1834 return &tp_regs->regs[nest_level - 1];
1835 }
1836
put_bpf_raw_tp_regs(void)1837 static void put_bpf_raw_tp_regs(void)
1838 {
1839 this_cpu_dec(bpf_raw_tp_nest_level);
1840 }
1841
BPF_CALL_5(bpf_perf_event_output_raw_tp,struct bpf_raw_tracepoint_args *,args,struct bpf_map *,map,u64,flags,void *,data,u64,size)1842 BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args,
1843 struct bpf_map *, map, u64, flags, void *, data, u64, size)
1844 {
1845 struct pt_regs *regs = get_bpf_raw_tp_regs();
1846 int ret;
1847
1848 if (IS_ERR(regs))
1849 return PTR_ERR(regs);
1850
1851 perf_fetch_caller_regs(regs);
1852 ret = ____bpf_perf_event_output(regs, map, flags, data, size);
1853
1854 put_bpf_raw_tp_regs();
1855 return ret;
1856 }
1857
1858 static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = {
1859 .func = bpf_perf_event_output_raw_tp,
1860 .gpl_only = true,
1861 .ret_type = RET_INTEGER,
1862 .arg1_type = ARG_PTR_TO_CTX,
1863 .arg2_type = ARG_CONST_MAP_PTR,
1864 .arg3_type = ARG_ANYTHING,
1865 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY,
1866 .arg5_type = ARG_CONST_SIZE_OR_ZERO,
1867 };
1868
1869 extern const struct bpf_func_proto bpf_skb_output_proto;
1870 extern const struct bpf_func_proto bpf_xdp_output_proto;
1871 extern const struct bpf_func_proto bpf_xdp_get_buff_len_trace_proto;
1872
BPF_CALL_3(bpf_get_stackid_raw_tp,struct bpf_raw_tracepoint_args *,args,struct bpf_map *,map,u64,flags)1873 BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args,
1874 struct bpf_map *, map, u64, flags)
1875 {
1876 struct pt_regs *regs = get_bpf_raw_tp_regs();
1877 int ret;
1878
1879 if (IS_ERR(regs))
1880 return PTR_ERR(regs);
1881
1882 perf_fetch_caller_regs(regs);
1883 /* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */
1884 ret = bpf_get_stackid((unsigned long) regs, (unsigned long) map,
1885 flags, 0, 0);
1886 put_bpf_raw_tp_regs();
1887 return ret;
1888 }
1889
1890 static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = {
1891 .func = bpf_get_stackid_raw_tp,
1892 .gpl_only = true,
1893 .ret_type = RET_INTEGER,
1894 .arg1_type = ARG_PTR_TO_CTX,
1895 .arg2_type = ARG_CONST_MAP_PTR,
1896 .arg3_type = ARG_ANYTHING,
1897 };
1898
BPF_CALL_4(bpf_get_stack_raw_tp,struct bpf_raw_tracepoint_args *,args,void *,buf,u32,size,u64,flags)1899 BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args,
1900 void *, buf, u32, size, u64, flags)
1901 {
1902 struct pt_regs *regs = get_bpf_raw_tp_regs();
1903 int ret;
1904
1905 if (IS_ERR(regs))
1906 return PTR_ERR(regs);
1907
1908 perf_fetch_caller_regs(regs);
1909 ret = bpf_get_stack((unsigned long) regs, (unsigned long) buf,
1910 (unsigned long) size, flags, 0);
1911 put_bpf_raw_tp_regs();
1912 return ret;
1913 }
1914
1915 static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = {
1916 .func = bpf_get_stack_raw_tp,
1917 .gpl_only = true,
1918 .ret_type = RET_INTEGER,
1919 .arg1_type = ARG_PTR_TO_CTX,
1920 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
1921 .arg3_type = ARG_CONST_SIZE_OR_ZERO,
1922 .arg4_type = ARG_ANYTHING,
1923 };
1924
1925 static const struct bpf_func_proto *
raw_tp_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1926 raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1927 {
1928 switch (func_id) {
1929 case BPF_FUNC_perf_event_output:
1930 return &bpf_perf_event_output_proto_raw_tp;
1931 case BPF_FUNC_get_stackid:
1932 return &bpf_get_stackid_proto_raw_tp;
1933 case BPF_FUNC_get_stack:
1934 return &bpf_get_stack_proto_raw_tp;
1935 case BPF_FUNC_get_attach_cookie:
1936 return &bpf_get_attach_cookie_proto_tracing;
1937 default:
1938 return bpf_tracing_func_proto(func_id, prog);
1939 }
1940 }
1941
1942 const struct bpf_func_proto *
tracing_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1943 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1944 {
1945 const struct bpf_func_proto *fn;
1946
1947 switch (func_id) {
1948 #ifdef CONFIG_NET
1949 case BPF_FUNC_skb_output:
1950 return &bpf_skb_output_proto;
1951 case BPF_FUNC_xdp_output:
1952 return &bpf_xdp_output_proto;
1953 case BPF_FUNC_skc_to_tcp6_sock:
1954 return &bpf_skc_to_tcp6_sock_proto;
1955 case BPF_FUNC_skc_to_tcp_sock:
1956 return &bpf_skc_to_tcp_sock_proto;
1957 case BPF_FUNC_skc_to_tcp_timewait_sock:
1958 return &bpf_skc_to_tcp_timewait_sock_proto;
1959 case BPF_FUNC_skc_to_tcp_request_sock:
1960 return &bpf_skc_to_tcp_request_sock_proto;
1961 case BPF_FUNC_skc_to_udp6_sock:
1962 return &bpf_skc_to_udp6_sock_proto;
1963 case BPF_FUNC_skc_to_unix_sock:
1964 return &bpf_skc_to_unix_sock_proto;
1965 case BPF_FUNC_skc_to_mptcp_sock:
1966 return &bpf_skc_to_mptcp_sock_proto;
1967 case BPF_FUNC_sk_storage_get:
1968 return &bpf_sk_storage_get_tracing_proto;
1969 case BPF_FUNC_sk_storage_delete:
1970 return &bpf_sk_storage_delete_tracing_proto;
1971 case BPF_FUNC_sock_from_file:
1972 return &bpf_sock_from_file_proto;
1973 case BPF_FUNC_get_socket_cookie:
1974 return &bpf_get_socket_ptr_cookie_proto;
1975 case BPF_FUNC_xdp_get_buff_len:
1976 return &bpf_xdp_get_buff_len_trace_proto;
1977 #endif
1978 case BPF_FUNC_seq_printf:
1979 return prog->expected_attach_type == BPF_TRACE_ITER ?
1980 &bpf_seq_printf_proto :
1981 NULL;
1982 case BPF_FUNC_seq_write:
1983 return prog->expected_attach_type == BPF_TRACE_ITER ?
1984 &bpf_seq_write_proto :
1985 NULL;
1986 case BPF_FUNC_seq_printf_btf:
1987 return prog->expected_attach_type == BPF_TRACE_ITER ?
1988 &bpf_seq_printf_btf_proto :
1989 NULL;
1990 case BPF_FUNC_d_path:
1991 return &bpf_d_path_proto;
1992 case BPF_FUNC_get_func_arg:
1993 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_proto : NULL;
1994 case BPF_FUNC_get_func_ret:
1995 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_ret_proto : NULL;
1996 case BPF_FUNC_get_func_arg_cnt:
1997 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_cnt_proto : NULL;
1998 case BPF_FUNC_get_attach_cookie:
1999 if (prog->type == BPF_PROG_TYPE_TRACING &&
2000 prog->expected_attach_type == BPF_TRACE_RAW_TP)
2001 return &bpf_get_attach_cookie_proto_tracing;
2002 return bpf_prog_has_trampoline(prog) ? &bpf_get_attach_cookie_proto_tracing : NULL;
2003 default:
2004 fn = raw_tp_prog_func_proto(func_id, prog);
2005 if (!fn && prog->expected_attach_type == BPF_TRACE_ITER)
2006 fn = bpf_iter_get_func_proto(func_id, prog);
2007 return fn;
2008 }
2009 }
2010
raw_tp_prog_is_valid_access(int off,int size,enum bpf_access_type type,const struct bpf_prog * prog,struct bpf_insn_access_aux * info)2011 static bool raw_tp_prog_is_valid_access(int off, int size,
2012 enum bpf_access_type type,
2013 const struct bpf_prog *prog,
2014 struct bpf_insn_access_aux *info)
2015 {
2016 return bpf_tracing_ctx_access(off, size, type);
2017 }
2018
tracing_prog_is_valid_access(int off,int size,enum bpf_access_type type,const struct bpf_prog * prog,struct bpf_insn_access_aux * info)2019 static bool tracing_prog_is_valid_access(int off, int size,
2020 enum bpf_access_type type,
2021 const struct bpf_prog *prog,
2022 struct bpf_insn_access_aux *info)
2023 {
2024 return bpf_tracing_btf_ctx_access(off, size, type, prog, info);
2025 }
2026
bpf_prog_test_run_tracing(struct bpf_prog * prog,const union bpf_attr * kattr,union bpf_attr __user * uattr)2027 int __weak bpf_prog_test_run_tracing(struct bpf_prog *prog,
2028 const union bpf_attr *kattr,
2029 union bpf_attr __user *uattr)
2030 {
2031 return -ENOTSUPP;
2032 }
2033
2034 const struct bpf_verifier_ops raw_tracepoint_verifier_ops = {
2035 .get_func_proto = raw_tp_prog_func_proto,
2036 .is_valid_access = raw_tp_prog_is_valid_access,
2037 };
2038
2039 const struct bpf_prog_ops raw_tracepoint_prog_ops = {
2040 #ifdef CONFIG_NET
2041 .test_run = bpf_prog_test_run_raw_tp,
2042 #endif
2043 };
2044
2045 const struct bpf_verifier_ops tracing_verifier_ops = {
2046 .get_func_proto = tracing_prog_func_proto,
2047 .is_valid_access = tracing_prog_is_valid_access,
2048 };
2049
2050 const struct bpf_prog_ops tracing_prog_ops = {
2051 .test_run = bpf_prog_test_run_tracing,
2052 };
2053
raw_tp_writable_prog_is_valid_access(int off,int size,enum bpf_access_type type,const struct bpf_prog * prog,struct bpf_insn_access_aux * info)2054 static bool raw_tp_writable_prog_is_valid_access(int off, int size,
2055 enum bpf_access_type type,
2056 const struct bpf_prog *prog,
2057 struct bpf_insn_access_aux *info)
2058 {
2059 if (off == 0) {
2060 if (size != sizeof(u64) || type != BPF_READ)
2061 return false;
2062 info->reg_type = PTR_TO_TP_BUFFER;
2063 }
2064 return raw_tp_prog_is_valid_access(off, size, type, prog, info);
2065 }
2066
2067 const struct bpf_verifier_ops raw_tracepoint_writable_verifier_ops = {
2068 .get_func_proto = raw_tp_prog_func_proto,
2069 .is_valid_access = raw_tp_writable_prog_is_valid_access,
2070 };
2071
2072 const struct bpf_prog_ops raw_tracepoint_writable_prog_ops = {
2073 };
2074
pe_prog_is_valid_access(int off,int size,enum bpf_access_type type,const struct bpf_prog * prog,struct bpf_insn_access_aux * info)2075 static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
2076 const struct bpf_prog *prog,
2077 struct bpf_insn_access_aux *info)
2078 {
2079 const int size_u64 = sizeof(u64);
2080
2081 if (off < 0 || off >= sizeof(struct bpf_perf_event_data))
2082 return false;
2083 if (type != BPF_READ)
2084 return false;
2085 if (off % size != 0) {
2086 if (sizeof(unsigned long) != 4)
2087 return false;
2088 if (size != 8)
2089 return false;
2090 if (off % size != 4)
2091 return false;
2092 }
2093
2094 switch (off) {
2095 case bpf_ctx_range(struct bpf_perf_event_data, sample_period):
2096 bpf_ctx_record_field_size(info, size_u64);
2097 if (!bpf_ctx_narrow_access_ok(off, size, size_u64))
2098 return false;
2099 break;
2100 case bpf_ctx_range(struct bpf_perf_event_data, addr):
2101 bpf_ctx_record_field_size(info, size_u64);
2102 if (!bpf_ctx_narrow_access_ok(off, size, size_u64))
2103 return false;
2104 break;
2105 default:
2106 if (size != sizeof(long))
2107 return false;
2108 }
2109
2110 return true;
2111 }
2112
pe_prog_convert_ctx_access(enum bpf_access_type type,const struct bpf_insn * si,struct bpf_insn * insn_buf,struct bpf_prog * prog,u32 * target_size)2113 static u32 pe_prog_convert_ctx_access(enum bpf_access_type type,
2114 const struct bpf_insn *si,
2115 struct bpf_insn *insn_buf,
2116 struct bpf_prog *prog, u32 *target_size)
2117 {
2118 struct bpf_insn *insn = insn_buf;
2119
2120 switch (si->off) {
2121 case offsetof(struct bpf_perf_event_data, sample_period):
2122 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
2123 data), si->dst_reg, si->src_reg,
2124 offsetof(struct bpf_perf_event_data_kern, data));
2125 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg,
2126 bpf_target_off(struct perf_sample_data, period, 8,
2127 target_size));
2128 break;
2129 case offsetof(struct bpf_perf_event_data, addr):
2130 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
2131 data), si->dst_reg, si->src_reg,
2132 offsetof(struct bpf_perf_event_data_kern, data));
2133 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg,
2134 bpf_target_off(struct perf_sample_data, addr, 8,
2135 target_size));
2136 break;
2137 default:
2138 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
2139 regs), si->dst_reg, si->src_reg,
2140 offsetof(struct bpf_perf_event_data_kern, regs));
2141 *insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg,
2142 si->off);
2143 break;
2144 }
2145
2146 return insn - insn_buf;
2147 }
2148
2149 const struct bpf_verifier_ops perf_event_verifier_ops = {
2150 .get_func_proto = pe_prog_func_proto,
2151 .is_valid_access = pe_prog_is_valid_access,
2152 .convert_ctx_access = pe_prog_convert_ctx_access,
2153 };
2154
2155 const struct bpf_prog_ops perf_event_prog_ops = {
2156 };
2157
2158 static DEFINE_MUTEX(bpf_event_mutex);
2159
2160 #define BPF_TRACE_MAX_PROGS 64
2161
perf_event_attach_bpf_prog(struct perf_event * event,struct bpf_prog * prog,u64 bpf_cookie)2162 int perf_event_attach_bpf_prog(struct perf_event *event,
2163 struct bpf_prog *prog,
2164 u64 bpf_cookie)
2165 {
2166 struct bpf_prog_array *old_array;
2167 struct bpf_prog_array *new_array;
2168 int ret = -EEXIST;
2169
2170 /*
2171 * Kprobe override only works if they are on the function entry,
2172 * and only if they are on the opt-in list.
2173 */
2174 if (prog->kprobe_override &&
2175 (!trace_kprobe_on_func_entry(event->tp_event) ||
2176 !trace_kprobe_error_injectable(event->tp_event)))
2177 return -EINVAL;
2178
2179 mutex_lock(&bpf_event_mutex);
2180
2181 if (event->prog)
2182 goto unlock;
2183
2184 old_array = bpf_event_rcu_dereference(event->tp_event->prog_array);
2185 if (old_array &&
2186 bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) {
2187 ret = -E2BIG;
2188 goto unlock;
2189 }
2190
2191 ret = bpf_prog_array_copy(old_array, NULL, prog, bpf_cookie, &new_array);
2192 if (ret < 0)
2193 goto unlock;
2194
2195 /* set the new array to event->tp_event and set event->prog */
2196 event->prog = prog;
2197 event->bpf_cookie = bpf_cookie;
2198 rcu_assign_pointer(event->tp_event->prog_array, new_array);
2199 bpf_prog_array_free_sleepable(old_array);
2200
2201 unlock:
2202 mutex_unlock(&bpf_event_mutex);
2203 return ret;
2204 }
2205
perf_event_detach_bpf_prog(struct perf_event * event)2206 void perf_event_detach_bpf_prog(struct perf_event *event)
2207 {
2208 struct bpf_prog_array *old_array;
2209 struct bpf_prog_array *new_array;
2210 int ret;
2211
2212 mutex_lock(&bpf_event_mutex);
2213
2214 if (!event->prog)
2215 goto unlock;
2216
2217 old_array = bpf_event_rcu_dereference(event->tp_event->prog_array);
2218 ret = bpf_prog_array_copy(old_array, event->prog, NULL, 0, &new_array);
2219 if (ret < 0) {
2220 bpf_prog_array_delete_safe(old_array, event->prog);
2221 } else {
2222 rcu_assign_pointer(event->tp_event->prog_array, new_array);
2223 bpf_prog_array_free_sleepable(old_array);
2224 }
2225
2226 bpf_prog_put(event->prog);
2227 event->prog = NULL;
2228
2229 unlock:
2230 mutex_unlock(&bpf_event_mutex);
2231 }
2232
perf_event_query_prog_array(struct perf_event * event,void __user * info)2233 int perf_event_query_prog_array(struct perf_event *event, void __user *info)
2234 {
2235 struct perf_event_query_bpf __user *uquery = info;
2236 struct perf_event_query_bpf query = {};
2237 struct bpf_prog_array *progs;
2238 u32 *ids, prog_cnt, ids_len;
2239 int ret;
2240
2241 if (!perfmon_capable())
2242 return -EPERM;
2243 if (event->attr.type != PERF_TYPE_TRACEPOINT)
2244 return -EINVAL;
2245 if (copy_from_user(&query, uquery, sizeof(query)))
2246 return -EFAULT;
2247
2248 ids_len = query.ids_len;
2249 if (ids_len > BPF_TRACE_MAX_PROGS)
2250 return -E2BIG;
2251 ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN);
2252 if (!ids)
2253 return -ENOMEM;
2254 /*
2255 * The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which
2256 * is required when user only wants to check for uquery->prog_cnt.
2257 * There is no need to check for it since the case is handled
2258 * gracefully in bpf_prog_array_copy_info.
2259 */
2260
2261 mutex_lock(&bpf_event_mutex);
2262 progs = bpf_event_rcu_dereference(event->tp_event->prog_array);
2263 ret = bpf_prog_array_copy_info(progs, ids, ids_len, &prog_cnt);
2264 mutex_unlock(&bpf_event_mutex);
2265
2266 if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) ||
2267 copy_to_user(uquery->ids, ids, ids_len * sizeof(u32)))
2268 ret = -EFAULT;
2269
2270 kfree(ids);
2271 return ret;
2272 }
2273
2274 extern struct bpf_raw_event_map __start__bpf_raw_tp[];
2275 extern struct bpf_raw_event_map __stop__bpf_raw_tp[];
2276
bpf_get_raw_tracepoint(const char * name)2277 struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name)
2278 {
2279 struct bpf_raw_event_map *btp = __start__bpf_raw_tp;
2280
2281 for (; btp < __stop__bpf_raw_tp; btp++) {
2282 if (!strcmp(btp->tp->name, name))
2283 return btp;
2284 }
2285
2286 return bpf_get_raw_tracepoint_module(name);
2287 }
2288
bpf_put_raw_tracepoint(struct bpf_raw_event_map * btp)2289 void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp)
2290 {
2291 struct module *mod;
2292
2293 preempt_disable();
2294 mod = __module_address((unsigned long)btp);
2295 module_put(mod);
2296 preempt_enable();
2297 }
2298
2299 static __always_inline
__bpf_trace_run(struct bpf_raw_tp_link * link,u64 * args)2300 void __bpf_trace_run(struct bpf_raw_tp_link *link, u64 *args)
2301 {
2302 struct bpf_prog *prog = link->link.prog;
2303 struct bpf_run_ctx *old_run_ctx;
2304 struct bpf_trace_run_ctx run_ctx;
2305
2306 cant_sleep();
2307 if (unlikely(this_cpu_inc_return(*(prog->active)) != 1)) {
2308 bpf_prog_inc_misses_counter(prog);
2309 goto out;
2310 }
2311
2312 run_ctx.bpf_cookie = link->cookie;
2313 old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx);
2314
2315 rcu_read_lock();
2316 (void) bpf_prog_run(prog, args);
2317 rcu_read_unlock();
2318
2319 bpf_reset_run_ctx(old_run_ctx);
2320 out:
2321 this_cpu_dec(*(prog->active));
2322 }
2323
2324 #define UNPACK(...) __VA_ARGS__
2325 #define REPEAT_1(FN, DL, X, ...) FN(X)
2326 #define REPEAT_2(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__)
2327 #define REPEAT_3(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_2(FN, DL, __VA_ARGS__)
2328 #define REPEAT_4(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_3(FN, DL, __VA_ARGS__)
2329 #define REPEAT_5(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_4(FN, DL, __VA_ARGS__)
2330 #define REPEAT_6(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_5(FN, DL, __VA_ARGS__)
2331 #define REPEAT_7(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_6(FN, DL, __VA_ARGS__)
2332 #define REPEAT_8(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_7(FN, DL, __VA_ARGS__)
2333 #define REPEAT_9(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_8(FN, DL, __VA_ARGS__)
2334 #define REPEAT_10(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_9(FN, DL, __VA_ARGS__)
2335 #define REPEAT_11(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_10(FN, DL, __VA_ARGS__)
2336 #define REPEAT_12(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_11(FN, DL, __VA_ARGS__)
2337 #define REPEAT(X, FN, DL, ...) REPEAT_##X(FN, DL, __VA_ARGS__)
2338
2339 #define SARG(X) u64 arg##X
2340 #define COPY(X) args[X] = arg##X
2341
2342 #define __DL_COM (,)
2343 #define __DL_SEM (;)
2344
2345 #define __SEQ_0_11 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11
2346
2347 #define BPF_TRACE_DEFN_x(x) \
2348 void bpf_trace_run##x(struct bpf_raw_tp_link *link, \
2349 REPEAT(x, SARG, __DL_COM, __SEQ_0_11)) \
2350 { \
2351 u64 args[x]; \
2352 REPEAT(x, COPY, __DL_SEM, __SEQ_0_11); \
2353 __bpf_trace_run(link, args); \
2354 } \
2355 EXPORT_SYMBOL_GPL(bpf_trace_run##x)
2356 BPF_TRACE_DEFN_x(1);
2357 BPF_TRACE_DEFN_x(2);
2358 BPF_TRACE_DEFN_x(3);
2359 BPF_TRACE_DEFN_x(4);
2360 BPF_TRACE_DEFN_x(5);
2361 BPF_TRACE_DEFN_x(6);
2362 BPF_TRACE_DEFN_x(7);
2363 BPF_TRACE_DEFN_x(8);
2364 BPF_TRACE_DEFN_x(9);
2365 BPF_TRACE_DEFN_x(10);
2366 BPF_TRACE_DEFN_x(11);
2367 BPF_TRACE_DEFN_x(12);
2368
bpf_probe_register(struct bpf_raw_event_map * btp,struct bpf_raw_tp_link * link)2369 int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_raw_tp_link *link)
2370 {
2371 struct tracepoint *tp = btp->tp;
2372 struct bpf_prog *prog = link->link.prog;
2373
2374 /*
2375 * check that program doesn't access arguments beyond what's
2376 * available in this tracepoint
2377 */
2378 if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64))
2379 return -EINVAL;
2380
2381 if (prog->aux->max_tp_access > btp->writable_size)
2382 return -EINVAL;
2383
2384 return tracepoint_probe_register_may_exist(tp, (void *)btp->bpf_func, link);
2385 }
2386
bpf_probe_unregister(struct bpf_raw_event_map * btp,struct bpf_raw_tp_link * link)2387 int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_raw_tp_link *link)
2388 {
2389 return tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, link);
2390 }
2391
bpf_get_perf_event_info(const struct perf_event * event,u32 * prog_id,u32 * fd_type,const char ** buf,u64 * probe_offset,u64 * probe_addr,unsigned long * missed)2392 int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id,
2393 u32 *fd_type, const char **buf,
2394 u64 *probe_offset, u64 *probe_addr,
2395 unsigned long *missed)
2396 {
2397 bool is_tracepoint, is_syscall_tp;
2398 struct bpf_prog *prog;
2399 int flags, err = 0;
2400
2401 prog = event->prog;
2402 if (!prog)
2403 return -ENOENT;
2404
2405 /* not supporting BPF_PROG_TYPE_PERF_EVENT yet */
2406 if (prog->type == BPF_PROG_TYPE_PERF_EVENT)
2407 return -EOPNOTSUPP;
2408
2409 *prog_id = prog->aux->id;
2410 flags = event->tp_event->flags;
2411 is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT;
2412 is_syscall_tp = is_syscall_trace_event(event->tp_event);
2413
2414 if (is_tracepoint || is_syscall_tp) {
2415 *buf = is_tracepoint ? event->tp_event->tp->name
2416 : event->tp_event->name;
2417 /* We allow NULL pointer for tracepoint */
2418 if (fd_type)
2419 *fd_type = BPF_FD_TYPE_TRACEPOINT;
2420 if (probe_offset)
2421 *probe_offset = 0x0;
2422 if (probe_addr)
2423 *probe_addr = 0x0;
2424 } else {
2425 /* kprobe/uprobe */
2426 err = -EOPNOTSUPP;
2427 #ifdef CONFIG_KPROBE_EVENTS
2428 if (flags & TRACE_EVENT_FL_KPROBE)
2429 err = bpf_get_kprobe_info(event, fd_type, buf,
2430 probe_offset, probe_addr, missed,
2431 event->attr.type == PERF_TYPE_TRACEPOINT);
2432 #endif
2433 #ifdef CONFIG_UPROBE_EVENTS
2434 if (flags & TRACE_EVENT_FL_UPROBE)
2435 err = bpf_get_uprobe_info(event, fd_type, buf,
2436 probe_offset, probe_addr,
2437 event->attr.type == PERF_TYPE_TRACEPOINT);
2438 #endif
2439 }
2440
2441 return err;
2442 }
2443
send_signal_irq_work_init(void)2444 static int __init send_signal_irq_work_init(void)
2445 {
2446 int cpu;
2447 struct send_signal_irq_work *work;
2448
2449 for_each_possible_cpu(cpu) {
2450 work = per_cpu_ptr(&send_signal_work, cpu);
2451 init_irq_work(&work->irq_work, do_bpf_send_signal);
2452 }
2453 return 0;
2454 }
2455
2456 subsys_initcall(send_signal_irq_work_init);
2457
2458 #ifdef CONFIG_MODULES
bpf_event_notify(struct notifier_block * nb,unsigned long op,void * module)2459 static int bpf_event_notify(struct notifier_block *nb, unsigned long op,
2460 void *module)
2461 {
2462 struct bpf_trace_module *btm, *tmp;
2463 struct module *mod = module;
2464 int ret = 0;
2465
2466 if (mod->num_bpf_raw_events == 0 ||
2467 (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING))
2468 goto out;
2469
2470 mutex_lock(&bpf_module_mutex);
2471
2472 switch (op) {
2473 case MODULE_STATE_COMING:
2474 btm = kzalloc(sizeof(*btm), GFP_KERNEL);
2475 if (btm) {
2476 btm->module = module;
2477 list_add(&btm->list, &bpf_trace_modules);
2478 } else {
2479 ret = -ENOMEM;
2480 }
2481 break;
2482 case MODULE_STATE_GOING:
2483 list_for_each_entry_safe(btm, tmp, &bpf_trace_modules, list) {
2484 if (btm->module == module) {
2485 list_del(&btm->list);
2486 kfree(btm);
2487 break;
2488 }
2489 }
2490 break;
2491 }
2492
2493 mutex_unlock(&bpf_module_mutex);
2494
2495 out:
2496 return notifier_from_errno(ret);
2497 }
2498
2499 static struct notifier_block bpf_module_nb = {
2500 .notifier_call = bpf_event_notify,
2501 };
2502
bpf_event_init(void)2503 static int __init bpf_event_init(void)
2504 {
2505 register_module_notifier(&bpf_module_nb);
2506 return 0;
2507 }
2508
2509 fs_initcall(bpf_event_init);
2510 #endif /* CONFIG_MODULES */
2511
2512 struct bpf_session_run_ctx {
2513 struct bpf_run_ctx run_ctx;
2514 bool is_return;
2515 void *data;
2516 };
2517
2518 #ifdef CONFIG_FPROBE
2519 struct bpf_kprobe_multi_link {
2520 struct bpf_link link;
2521 struct fprobe fp;
2522 unsigned long *addrs;
2523 u64 *cookies;
2524 u32 cnt;
2525 u32 mods_cnt;
2526 struct module **mods;
2527 u32 flags;
2528 };
2529
2530 struct bpf_kprobe_multi_run_ctx {
2531 struct bpf_session_run_ctx session_ctx;
2532 struct bpf_kprobe_multi_link *link;
2533 unsigned long entry_ip;
2534 };
2535
2536 struct user_syms {
2537 const char **syms;
2538 char *buf;
2539 };
2540
copy_user_syms(struct user_syms * us,unsigned long __user * usyms,u32 cnt)2541 static int copy_user_syms(struct user_syms *us, unsigned long __user *usyms, u32 cnt)
2542 {
2543 unsigned long __user usymbol;
2544 const char **syms = NULL;
2545 char *buf = NULL, *p;
2546 int err = -ENOMEM;
2547 unsigned int i;
2548
2549 syms = kvmalloc_array(cnt, sizeof(*syms), GFP_KERNEL);
2550 if (!syms)
2551 goto error;
2552
2553 buf = kvmalloc_array(cnt, KSYM_NAME_LEN, GFP_KERNEL);
2554 if (!buf)
2555 goto error;
2556
2557 for (p = buf, i = 0; i < cnt; i++) {
2558 if (__get_user(usymbol, usyms + i)) {
2559 err = -EFAULT;
2560 goto error;
2561 }
2562 err = strncpy_from_user(p, (const char __user *) usymbol, KSYM_NAME_LEN);
2563 if (err == KSYM_NAME_LEN)
2564 err = -E2BIG;
2565 if (err < 0)
2566 goto error;
2567 syms[i] = p;
2568 p += err + 1;
2569 }
2570
2571 us->syms = syms;
2572 us->buf = buf;
2573 return 0;
2574
2575 error:
2576 if (err) {
2577 kvfree(syms);
2578 kvfree(buf);
2579 }
2580 return err;
2581 }
2582
kprobe_multi_put_modules(struct module ** mods,u32 cnt)2583 static void kprobe_multi_put_modules(struct module **mods, u32 cnt)
2584 {
2585 u32 i;
2586
2587 for (i = 0; i < cnt; i++)
2588 module_put(mods[i]);
2589 }
2590
free_user_syms(struct user_syms * us)2591 static void free_user_syms(struct user_syms *us)
2592 {
2593 kvfree(us->syms);
2594 kvfree(us->buf);
2595 }
2596
bpf_kprobe_multi_link_release(struct bpf_link * link)2597 static void bpf_kprobe_multi_link_release(struct bpf_link *link)
2598 {
2599 struct bpf_kprobe_multi_link *kmulti_link;
2600
2601 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);
2602 unregister_fprobe(&kmulti_link->fp);
2603 kprobe_multi_put_modules(kmulti_link->mods, kmulti_link->mods_cnt);
2604 }
2605
bpf_kprobe_multi_link_dealloc(struct bpf_link * link)2606 static void bpf_kprobe_multi_link_dealloc(struct bpf_link *link)
2607 {
2608 struct bpf_kprobe_multi_link *kmulti_link;
2609
2610 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);
2611 kvfree(kmulti_link->addrs);
2612 kvfree(kmulti_link->cookies);
2613 kfree(kmulti_link->mods);
2614 kfree(kmulti_link);
2615 }
2616
bpf_kprobe_multi_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)2617 static int bpf_kprobe_multi_link_fill_link_info(const struct bpf_link *link,
2618 struct bpf_link_info *info)
2619 {
2620 u64 __user *ucookies = u64_to_user_ptr(info->kprobe_multi.cookies);
2621 u64 __user *uaddrs = u64_to_user_ptr(info->kprobe_multi.addrs);
2622 struct bpf_kprobe_multi_link *kmulti_link;
2623 u32 ucount = info->kprobe_multi.count;
2624 int err = 0, i;
2625
2626 if (!uaddrs ^ !ucount)
2627 return -EINVAL;
2628 if (ucookies && !ucount)
2629 return -EINVAL;
2630
2631 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);
2632 info->kprobe_multi.count = kmulti_link->cnt;
2633 info->kprobe_multi.flags = kmulti_link->flags;
2634 info->kprobe_multi.missed = kmulti_link->fp.nmissed;
2635
2636 if (!uaddrs)
2637 return 0;
2638 if (ucount < kmulti_link->cnt)
2639 err = -ENOSPC;
2640 else
2641 ucount = kmulti_link->cnt;
2642
2643 if (ucookies) {
2644 if (kmulti_link->cookies) {
2645 if (copy_to_user(ucookies, kmulti_link->cookies, ucount * sizeof(u64)))
2646 return -EFAULT;
2647 } else {
2648 for (i = 0; i < ucount; i++) {
2649 if (put_user(0, ucookies + i))
2650 return -EFAULT;
2651 }
2652 }
2653 }
2654
2655 if (kallsyms_show_value(current_cred())) {
2656 if (copy_to_user(uaddrs, kmulti_link->addrs, ucount * sizeof(u64)))
2657 return -EFAULT;
2658 } else {
2659 for (i = 0; i < ucount; i++) {
2660 if (put_user(0, uaddrs + i))
2661 return -EFAULT;
2662 }
2663 }
2664 return err;
2665 }
2666
2667 static const struct bpf_link_ops bpf_kprobe_multi_link_lops = {
2668 .release = bpf_kprobe_multi_link_release,
2669 .dealloc_deferred = bpf_kprobe_multi_link_dealloc,
2670 .fill_link_info = bpf_kprobe_multi_link_fill_link_info,
2671 };
2672
bpf_kprobe_multi_cookie_swap(void * a,void * b,int size,const void * priv)2673 static void bpf_kprobe_multi_cookie_swap(void *a, void *b, int size, const void *priv)
2674 {
2675 const struct bpf_kprobe_multi_link *link = priv;
2676 unsigned long *addr_a = a, *addr_b = b;
2677 u64 *cookie_a, *cookie_b;
2678
2679 cookie_a = link->cookies + (addr_a - link->addrs);
2680 cookie_b = link->cookies + (addr_b - link->addrs);
2681
2682 /* swap addr_a/addr_b and cookie_a/cookie_b values */
2683 swap(*addr_a, *addr_b);
2684 swap(*cookie_a, *cookie_b);
2685 }
2686
bpf_kprobe_multi_addrs_cmp(const void * a,const void * b)2687 static int bpf_kprobe_multi_addrs_cmp(const void *a, const void *b)
2688 {
2689 const unsigned long *addr_a = a, *addr_b = b;
2690
2691 if (*addr_a == *addr_b)
2692 return 0;
2693 return *addr_a < *addr_b ? -1 : 1;
2694 }
2695
bpf_kprobe_multi_cookie_cmp(const void * a,const void * b,const void * priv)2696 static int bpf_kprobe_multi_cookie_cmp(const void *a, const void *b, const void *priv)
2697 {
2698 return bpf_kprobe_multi_addrs_cmp(a, b);
2699 }
2700
bpf_kprobe_multi_cookie(struct bpf_run_ctx * ctx)2701 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx)
2702 {
2703 struct bpf_kprobe_multi_run_ctx *run_ctx;
2704 struct bpf_kprobe_multi_link *link;
2705 u64 *cookie, entry_ip;
2706 unsigned long *addr;
2707
2708 if (WARN_ON_ONCE(!ctx))
2709 return 0;
2710 run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx,
2711 session_ctx.run_ctx);
2712 link = run_ctx->link;
2713 if (!link->cookies)
2714 return 0;
2715 entry_ip = run_ctx->entry_ip;
2716 addr = bsearch(&entry_ip, link->addrs, link->cnt, sizeof(entry_ip),
2717 bpf_kprobe_multi_addrs_cmp);
2718 if (!addr)
2719 return 0;
2720 cookie = link->cookies + (addr - link->addrs);
2721 return *cookie;
2722 }
2723
bpf_kprobe_multi_entry_ip(struct bpf_run_ctx * ctx)2724 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
2725 {
2726 struct bpf_kprobe_multi_run_ctx *run_ctx;
2727
2728 run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx,
2729 session_ctx.run_ctx);
2730 return run_ctx->entry_ip;
2731 }
2732
2733 static int
kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link * link,unsigned long entry_ip,struct pt_regs * regs,bool is_return,void * data)2734 kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link,
2735 unsigned long entry_ip, struct pt_regs *regs,
2736 bool is_return, void *data)
2737 {
2738 struct bpf_kprobe_multi_run_ctx run_ctx = {
2739 .session_ctx = {
2740 .is_return = is_return,
2741 .data = data,
2742 },
2743 .link = link,
2744 .entry_ip = entry_ip,
2745 };
2746 struct bpf_run_ctx *old_run_ctx;
2747 int err;
2748
2749 if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) {
2750 bpf_prog_inc_misses_counter(link->link.prog);
2751 err = 0;
2752 goto out;
2753 }
2754
2755 migrate_disable();
2756 rcu_read_lock();
2757 old_run_ctx = bpf_set_run_ctx(&run_ctx.session_ctx.run_ctx);
2758 err = bpf_prog_run(link->link.prog, regs);
2759 bpf_reset_run_ctx(old_run_ctx);
2760 rcu_read_unlock();
2761 migrate_enable();
2762
2763 out:
2764 __this_cpu_dec(bpf_prog_active);
2765 return err;
2766 }
2767
2768 static int
kprobe_multi_link_handler(struct fprobe * fp,unsigned long fentry_ip,unsigned long ret_ip,struct pt_regs * regs,void * data)2769 kprobe_multi_link_handler(struct fprobe *fp, unsigned long fentry_ip,
2770 unsigned long ret_ip, struct pt_regs *regs,
2771 void *data)
2772 {
2773 struct bpf_kprobe_multi_link *link;
2774 int err;
2775
2776 link = container_of(fp, struct bpf_kprobe_multi_link, fp);
2777 err = kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), regs, false, data);
2778 return is_kprobe_session(link->link.prog) ? err : 0;
2779 }
2780
2781 static void
kprobe_multi_link_exit_handler(struct fprobe * fp,unsigned long fentry_ip,unsigned long ret_ip,struct pt_regs * regs,void * data)2782 kprobe_multi_link_exit_handler(struct fprobe *fp, unsigned long fentry_ip,
2783 unsigned long ret_ip, struct pt_regs *regs,
2784 void *data)
2785 {
2786 struct bpf_kprobe_multi_link *link;
2787
2788 link = container_of(fp, struct bpf_kprobe_multi_link, fp);
2789 kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), regs, true, data);
2790 }
2791
symbols_cmp_r(const void * a,const void * b,const void * priv)2792 static int symbols_cmp_r(const void *a, const void *b, const void *priv)
2793 {
2794 const char **str_a = (const char **) a;
2795 const char **str_b = (const char **) b;
2796
2797 return strcmp(*str_a, *str_b);
2798 }
2799
2800 struct multi_symbols_sort {
2801 const char **funcs;
2802 u64 *cookies;
2803 };
2804
symbols_swap_r(void * a,void * b,int size,const void * priv)2805 static void symbols_swap_r(void *a, void *b, int size, const void *priv)
2806 {
2807 const struct multi_symbols_sort *data = priv;
2808 const char **name_a = a, **name_b = b;
2809
2810 swap(*name_a, *name_b);
2811
2812 /* If defined, swap also related cookies. */
2813 if (data->cookies) {
2814 u64 *cookie_a, *cookie_b;
2815
2816 cookie_a = data->cookies + (name_a - data->funcs);
2817 cookie_b = data->cookies + (name_b - data->funcs);
2818 swap(*cookie_a, *cookie_b);
2819 }
2820 }
2821
2822 struct modules_array {
2823 struct module **mods;
2824 int mods_cnt;
2825 int mods_cap;
2826 };
2827
add_module(struct modules_array * arr,struct module * mod)2828 static int add_module(struct modules_array *arr, struct module *mod)
2829 {
2830 struct module **mods;
2831
2832 if (arr->mods_cnt == arr->mods_cap) {
2833 arr->mods_cap = max(16, arr->mods_cap * 3 / 2);
2834 mods = krealloc_array(arr->mods, arr->mods_cap, sizeof(*mods), GFP_KERNEL);
2835 if (!mods)
2836 return -ENOMEM;
2837 arr->mods = mods;
2838 }
2839
2840 arr->mods[arr->mods_cnt] = mod;
2841 arr->mods_cnt++;
2842 return 0;
2843 }
2844
has_module(struct modules_array * arr,struct module * mod)2845 static bool has_module(struct modules_array *arr, struct module *mod)
2846 {
2847 int i;
2848
2849 for (i = arr->mods_cnt - 1; i >= 0; i--) {
2850 if (arr->mods[i] == mod)
2851 return true;
2852 }
2853 return false;
2854 }
2855
get_modules_for_addrs(struct module *** mods,unsigned long * addrs,u32 addrs_cnt)2856 static int get_modules_for_addrs(struct module ***mods, unsigned long *addrs, u32 addrs_cnt)
2857 {
2858 struct modules_array arr = {};
2859 u32 i, err = 0;
2860
2861 for (i = 0; i < addrs_cnt; i++) {
2862 struct module *mod;
2863
2864 preempt_disable();
2865 mod = __module_address(addrs[i]);
2866 /* Either no module or we it's already stored */
2867 if (!mod || has_module(&arr, mod)) {
2868 preempt_enable();
2869 continue;
2870 }
2871 if (!try_module_get(mod))
2872 err = -EINVAL;
2873 preempt_enable();
2874 if (err)
2875 break;
2876 err = add_module(&arr, mod);
2877 if (err) {
2878 module_put(mod);
2879 break;
2880 }
2881 }
2882
2883 /* We return either err < 0 in case of error, ... */
2884 if (err) {
2885 kprobe_multi_put_modules(arr.mods, arr.mods_cnt);
2886 kfree(arr.mods);
2887 return err;
2888 }
2889
2890 /* or number of modules found if everything is ok. */
2891 *mods = arr.mods;
2892 return arr.mods_cnt;
2893 }
2894
addrs_check_error_injection_list(unsigned long * addrs,u32 cnt)2895 static int addrs_check_error_injection_list(unsigned long *addrs, u32 cnt)
2896 {
2897 u32 i;
2898
2899 for (i = 0; i < cnt; i++) {
2900 if (!within_error_injection_list(addrs[i]))
2901 return -EINVAL;
2902 }
2903 return 0;
2904 }
2905
bpf_kprobe_multi_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)2906 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
2907 {
2908 struct bpf_kprobe_multi_link *link = NULL;
2909 struct bpf_link_primer link_primer;
2910 void __user *ucookies;
2911 unsigned long *addrs;
2912 u32 flags, cnt, size;
2913 void __user *uaddrs;
2914 u64 *cookies = NULL;
2915 void __user *usyms;
2916 int err;
2917
2918 /* no support for 32bit archs yet */
2919 if (sizeof(u64) != sizeof(void *))
2920 return -EOPNOTSUPP;
2921
2922 if (!is_kprobe_multi(prog))
2923 return -EINVAL;
2924
2925 flags = attr->link_create.kprobe_multi.flags;
2926 if (flags & ~BPF_F_KPROBE_MULTI_RETURN)
2927 return -EINVAL;
2928
2929 uaddrs = u64_to_user_ptr(attr->link_create.kprobe_multi.addrs);
2930 usyms = u64_to_user_ptr(attr->link_create.kprobe_multi.syms);
2931 if (!!uaddrs == !!usyms)
2932 return -EINVAL;
2933
2934 cnt = attr->link_create.kprobe_multi.cnt;
2935 if (!cnt)
2936 return -EINVAL;
2937 if (cnt > MAX_KPROBE_MULTI_CNT)
2938 return -E2BIG;
2939
2940 size = cnt * sizeof(*addrs);
2941 addrs = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL);
2942 if (!addrs)
2943 return -ENOMEM;
2944
2945 ucookies = u64_to_user_ptr(attr->link_create.kprobe_multi.cookies);
2946 if (ucookies) {
2947 cookies = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL);
2948 if (!cookies) {
2949 err = -ENOMEM;
2950 goto error;
2951 }
2952 if (copy_from_user(cookies, ucookies, size)) {
2953 err = -EFAULT;
2954 goto error;
2955 }
2956 }
2957
2958 if (uaddrs) {
2959 if (copy_from_user(addrs, uaddrs, size)) {
2960 err = -EFAULT;
2961 goto error;
2962 }
2963 } else {
2964 struct multi_symbols_sort data = {
2965 .cookies = cookies,
2966 };
2967 struct user_syms us;
2968
2969 err = copy_user_syms(&us, usyms, cnt);
2970 if (err)
2971 goto error;
2972
2973 if (cookies)
2974 data.funcs = us.syms;
2975
2976 sort_r(us.syms, cnt, sizeof(*us.syms), symbols_cmp_r,
2977 symbols_swap_r, &data);
2978
2979 err = ftrace_lookup_symbols(us.syms, cnt, addrs);
2980 free_user_syms(&us);
2981 if (err)
2982 goto error;
2983 }
2984
2985 if (prog->kprobe_override && addrs_check_error_injection_list(addrs, cnt)) {
2986 err = -EINVAL;
2987 goto error;
2988 }
2989
2990 link = kzalloc(sizeof(*link), GFP_KERNEL);
2991 if (!link) {
2992 err = -ENOMEM;
2993 goto error;
2994 }
2995
2996 bpf_link_init(&link->link, BPF_LINK_TYPE_KPROBE_MULTI,
2997 &bpf_kprobe_multi_link_lops, prog);
2998
2999 err = bpf_link_prime(&link->link, &link_primer);
3000 if (err)
3001 goto error;
3002
3003 if (!(flags & BPF_F_KPROBE_MULTI_RETURN))
3004 link->fp.entry_handler = kprobe_multi_link_handler;
3005 if ((flags & BPF_F_KPROBE_MULTI_RETURN) || is_kprobe_session(prog))
3006 link->fp.exit_handler = kprobe_multi_link_exit_handler;
3007 if (is_kprobe_session(prog))
3008 link->fp.entry_data_size = sizeof(u64);
3009
3010 link->addrs = addrs;
3011 link->cookies = cookies;
3012 link->cnt = cnt;
3013 link->flags = flags;
3014
3015 if (cookies) {
3016 /*
3017 * Sorting addresses will trigger sorting cookies as well
3018 * (check bpf_kprobe_multi_cookie_swap). This way we can
3019 * find cookie based on the address in bpf_get_attach_cookie
3020 * helper.
3021 */
3022 sort_r(addrs, cnt, sizeof(*addrs),
3023 bpf_kprobe_multi_cookie_cmp,
3024 bpf_kprobe_multi_cookie_swap,
3025 link);
3026 }
3027
3028 err = get_modules_for_addrs(&link->mods, addrs, cnt);
3029 if (err < 0) {
3030 bpf_link_cleanup(&link_primer);
3031 return err;
3032 }
3033 link->mods_cnt = err;
3034
3035 err = register_fprobe_ips(&link->fp, addrs, cnt);
3036 if (err) {
3037 kprobe_multi_put_modules(link->mods, link->mods_cnt);
3038 bpf_link_cleanup(&link_primer);
3039 return err;
3040 }
3041
3042 return bpf_link_settle(&link_primer);
3043
3044 error:
3045 kfree(link);
3046 kvfree(addrs);
3047 kvfree(cookies);
3048 return err;
3049 }
3050 #else /* !CONFIG_FPROBE */
bpf_kprobe_multi_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)3051 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
3052 {
3053 return -EOPNOTSUPP;
3054 }
bpf_kprobe_multi_cookie(struct bpf_run_ctx * ctx)3055 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx)
3056 {
3057 return 0;
3058 }
bpf_kprobe_multi_entry_ip(struct bpf_run_ctx * ctx)3059 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
3060 {
3061 return 0;
3062 }
3063 #endif
3064
3065 #ifdef CONFIG_UPROBES
3066 struct bpf_uprobe_multi_link;
3067
3068 struct bpf_uprobe {
3069 struct bpf_uprobe_multi_link *link;
3070 loff_t offset;
3071 unsigned long ref_ctr_offset;
3072 u64 cookie;
3073 struct uprobe *uprobe;
3074 struct uprobe_consumer consumer;
3075 };
3076
3077 struct bpf_uprobe_multi_link {
3078 struct path path;
3079 struct bpf_link link;
3080 u32 cnt;
3081 u32 flags;
3082 struct bpf_uprobe *uprobes;
3083 struct task_struct *task;
3084 };
3085
3086 struct bpf_uprobe_multi_run_ctx {
3087 struct bpf_run_ctx run_ctx;
3088 unsigned long entry_ip;
3089 struct bpf_uprobe *uprobe;
3090 };
3091
bpf_uprobe_unregister(struct bpf_uprobe * uprobes,u32 cnt)3092 static void bpf_uprobe_unregister(struct bpf_uprobe *uprobes, u32 cnt)
3093 {
3094 u32 i;
3095
3096 for (i = 0; i < cnt; i++)
3097 uprobe_unregister_nosync(uprobes[i].uprobe, &uprobes[i].consumer);
3098
3099 if (cnt)
3100 uprobe_unregister_sync();
3101 }
3102
bpf_uprobe_multi_link_release(struct bpf_link * link)3103 static void bpf_uprobe_multi_link_release(struct bpf_link *link)
3104 {
3105 struct bpf_uprobe_multi_link *umulti_link;
3106
3107 umulti_link = container_of(link, struct bpf_uprobe_multi_link, link);
3108 bpf_uprobe_unregister(umulti_link->uprobes, umulti_link->cnt);
3109 if (umulti_link->task)
3110 put_task_struct(umulti_link->task);
3111 path_put(&umulti_link->path);
3112 }
3113
bpf_uprobe_multi_link_dealloc(struct bpf_link * link)3114 static void bpf_uprobe_multi_link_dealloc(struct bpf_link *link)
3115 {
3116 struct bpf_uprobe_multi_link *umulti_link;
3117
3118 umulti_link = container_of(link, struct bpf_uprobe_multi_link, link);
3119 kvfree(umulti_link->uprobes);
3120 kfree(umulti_link);
3121 }
3122
bpf_uprobe_multi_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)3123 static int bpf_uprobe_multi_link_fill_link_info(const struct bpf_link *link,
3124 struct bpf_link_info *info)
3125 {
3126 u64 __user *uref_ctr_offsets = u64_to_user_ptr(info->uprobe_multi.ref_ctr_offsets);
3127 u64 __user *ucookies = u64_to_user_ptr(info->uprobe_multi.cookies);
3128 u64 __user *uoffsets = u64_to_user_ptr(info->uprobe_multi.offsets);
3129 u64 __user *upath = u64_to_user_ptr(info->uprobe_multi.path);
3130 u32 upath_size = info->uprobe_multi.path_size;
3131 struct bpf_uprobe_multi_link *umulti_link;
3132 u32 ucount = info->uprobe_multi.count;
3133 int err = 0, i;
3134 char *p, *buf;
3135 long left = 0;
3136
3137 if (!upath ^ !upath_size)
3138 return -EINVAL;
3139
3140 if ((uoffsets || uref_ctr_offsets || ucookies) && !ucount)
3141 return -EINVAL;
3142
3143 umulti_link = container_of(link, struct bpf_uprobe_multi_link, link);
3144 info->uprobe_multi.count = umulti_link->cnt;
3145 info->uprobe_multi.flags = umulti_link->flags;
3146 info->uprobe_multi.pid = umulti_link->task ?
3147 task_pid_nr_ns(umulti_link->task, task_active_pid_ns(current)) : 0;
3148
3149 upath_size = upath_size ? min_t(u32, upath_size, PATH_MAX) : PATH_MAX;
3150 buf = kmalloc(upath_size, GFP_KERNEL);
3151 if (!buf)
3152 return -ENOMEM;
3153 p = d_path(&umulti_link->path, buf, upath_size);
3154 if (IS_ERR(p)) {
3155 kfree(buf);
3156 return PTR_ERR(p);
3157 }
3158 upath_size = buf + upath_size - p;
3159
3160 if (upath)
3161 left = copy_to_user(upath, p, upath_size);
3162 kfree(buf);
3163 if (left)
3164 return -EFAULT;
3165 info->uprobe_multi.path_size = upath_size;
3166
3167 if (!uoffsets && !ucookies && !uref_ctr_offsets)
3168 return 0;
3169
3170 if (ucount < umulti_link->cnt)
3171 err = -ENOSPC;
3172 else
3173 ucount = umulti_link->cnt;
3174
3175 for (i = 0; i < ucount; i++) {
3176 if (uoffsets &&
3177 put_user(umulti_link->uprobes[i].offset, uoffsets + i))
3178 return -EFAULT;
3179 if (uref_ctr_offsets &&
3180 put_user(umulti_link->uprobes[i].ref_ctr_offset, uref_ctr_offsets + i))
3181 return -EFAULT;
3182 if (ucookies &&
3183 put_user(umulti_link->uprobes[i].cookie, ucookies + i))
3184 return -EFAULT;
3185 }
3186
3187 return err;
3188 }
3189
3190 static const struct bpf_link_ops bpf_uprobe_multi_link_lops = {
3191 .release = bpf_uprobe_multi_link_release,
3192 .dealloc_deferred = bpf_uprobe_multi_link_dealloc,
3193 .fill_link_info = bpf_uprobe_multi_link_fill_link_info,
3194 };
3195
uprobe_prog_run(struct bpf_uprobe * uprobe,unsigned long entry_ip,struct pt_regs * regs)3196 static int uprobe_prog_run(struct bpf_uprobe *uprobe,
3197 unsigned long entry_ip,
3198 struct pt_regs *regs)
3199 {
3200 struct bpf_uprobe_multi_link *link = uprobe->link;
3201 struct bpf_uprobe_multi_run_ctx run_ctx = {
3202 .entry_ip = entry_ip,
3203 .uprobe = uprobe,
3204 };
3205 struct bpf_prog *prog = link->link.prog;
3206 bool sleepable = prog->sleepable;
3207 struct bpf_run_ctx *old_run_ctx;
3208 int err = 0;
3209
3210 if (link->task && !same_thread_group(current, link->task))
3211 return 0;
3212
3213 if (sleepable)
3214 rcu_read_lock_trace();
3215 else
3216 rcu_read_lock();
3217
3218 migrate_disable();
3219
3220 old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx);
3221 err = bpf_prog_run(link->link.prog, regs);
3222 bpf_reset_run_ctx(old_run_ctx);
3223
3224 migrate_enable();
3225
3226 if (sleepable)
3227 rcu_read_unlock_trace();
3228 else
3229 rcu_read_unlock();
3230 return err;
3231 }
3232
3233 static bool
uprobe_multi_link_filter(struct uprobe_consumer * con,struct mm_struct * mm)3234 uprobe_multi_link_filter(struct uprobe_consumer *con, struct mm_struct *mm)
3235 {
3236 struct bpf_uprobe *uprobe;
3237
3238 uprobe = container_of(con, struct bpf_uprobe, consumer);
3239 return uprobe->link->task->mm == mm;
3240 }
3241
3242 static int
uprobe_multi_link_handler(struct uprobe_consumer * con,struct pt_regs * regs)3243 uprobe_multi_link_handler(struct uprobe_consumer *con, struct pt_regs *regs)
3244 {
3245 struct bpf_uprobe *uprobe;
3246
3247 uprobe = container_of(con, struct bpf_uprobe, consumer);
3248 return uprobe_prog_run(uprobe, instruction_pointer(regs), regs);
3249 }
3250
3251 static int
uprobe_multi_link_ret_handler(struct uprobe_consumer * con,unsigned long func,struct pt_regs * regs)3252 uprobe_multi_link_ret_handler(struct uprobe_consumer *con, unsigned long func, struct pt_regs *regs)
3253 {
3254 struct bpf_uprobe *uprobe;
3255
3256 uprobe = container_of(con, struct bpf_uprobe, consumer);
3257 return uprobe_prog_run(uprobe, func, regs);
3258 }
3259
bpf_uprobe_multi_entry_ip(struct bpf_run_ctx * ctx)3260 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
3261 {
3262 struct bpf_uprobe_multi_run_ctx *run_ctx;
3263
3264 run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx, run_ctx);
3265 return run_ctx->entry_ip;
3266 }
3267
bpf_uprobe_multi_cookie(struct bpf_run_ctx * ctx)3268 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx)
3269 {
3270 struct bpf_uprobe_multi_run_ctx *run_ctx;
3271
3272 run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx, run_ctx);
3273 return run_ctx->uprobe->cookie;
3274 }
3275
bpf_uprobe_multi_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)3276 int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
3277 {
3278 struct bpf_uprobe_multi_link *link = NULL;
3279 unsigned long __user *uref_ctr_offsets;
3280 struct bpf_link_primer link_primer;
3281 struct bpf_uprobe *uprobes = NULL;
3282 struct task_struct *task = NULL;
3283 unsigned long __user *uoffsets;
3284 u64 __user *ucookies;
3285 void __user *upath;
3286 u32 flags, cnt, i;
3287 struct path path;
3288 char *name;
3289 pid_t pid;
3290 int err;
3291
3292 /* no support for 32bit archs yet */
3293 if (sizeof(u64) != sizeof(void *))
3294 return -EOPNOTSUPP;
3295
3296 if (prog->expected_attach_type != BPF_TRACE_UPROBE_MULTI)
3297 return -EINVAL;
3298
3299 flags = attr->link_create.uprobe_multi.flags;
3300 if (flags & ~BPF_F_UPROBE_MULTI_RETURN)
3301 return -EINVAL;
3302
3303 /*
3304 * path, offsets and cnt are mandatory,
3305 * ref_ctr_offsets and cookies are optional
3306 */
3307 upath = u64_to_user_ptr(attr->link_create.uprobe_multi.path);
3308 uoffsets = u64_to_user_ptr(attr->link_create.uprobe_multi.offsets);
3309 cnt = attr->link_create.uprobe_multi.cnt;
3310 pid = attr->link_create.uprobe_multi.pid;
3311
3312 if (!upath || !uoffsets || !cnt || pid < 0)
3313 return -EINVAL;
3314 if (cnt > MAX_UPROBE_MULTI_CNT)
3315 return -E2BIG;
3316
3317 uref_ctr_offsets = u64_to_user_ptr(attr->link_create.uprobe_multi.ref_ctr_offsets);
3318 ucookies = u64_to_user_ptr(attr->link_create.uprobe_multi.cookies);
3319
3320 name = strndup_user(upath, PATH_MAX);
3321 if (IS_ERR(name)) {
3322 err = PTR_ERR(name);
3323 return err;
3324 }
3325
3326 err = kern_path(name, LOOKUP_FOLLOW, &path);
3327 kfree(name);
3328 if (err)
3329 return err;
3330
3331 if (!d_is_reg(path.dentry)) {
3332 err = -EBADF;
3333 goto error_path_put;
3334 }
3335
3336 if (pid) {
3337 task = get_pid_task(find_vpid(pid), PIDTYPE_TGID);
3338 if (!task) {
3339 err = -ESRCH;
3340 goto error_path_put;
3341 }
3342 }
3343
3344 err = -ENOMEM;
3345
3346 link = kzalloc(sizeof(*link), GFP_KERNEL);
3347 uprobes = kvcalloc(cnt, sizeof(*uprobes), GFP_KERNEL);
3348
3349 if (!uprobes || !link)
3350 goto error_free;
3351
3352 for (i = 0; i < cnt; i++) {
3353 if (__get_user(uprobes[i].offset, uoffsets + i)) {
3354 err = -EFAULT;
3355 goto error_free;
3356 }
3357 if (uprobes[i].offset < 0) {
3358 err = -EINVAL;
3359 goto error_free;
3360 }
3361 if (uref_ctr_offsets && __get_user(uprobes[i].ref_ctr_offset, uref_ctr_offsets + i)) {
3362 err = -EFAULT;
3363 goto error_free;
3364 }
3365 if (ucookies && __get_user(uprobes[i].cookie, ucookies + i)) {
3366 err = -EFAULT;
3367 goto error_free;
3368 }
3369
3370 uprobes[i].link = link;
3371
3372 if (flags & BPF_F_UPROBE_MULTI_RETURN)
3373 uprobes[i].consumer.ret_handler = uprobe_multi_link_ret_handler;
3374 else
3375 uprobes[i].consumer.handler = uprobe_multi_link_handler;
3376
3377 if (pid)
3378 uprobes[i].consumer.filter = uprobe_multi_link_filter;
3379 }
3380
3381 link->cnt = cnt;
3382 link->uprobes = uprobes;
3383 link->path = path;
3384 link->task = task;
3385 link->flags = flags;
3386
3387 bpf_link_init(&link->link, BPF_LINK_TYPE_UPROBE_MULTI,
3388 &bpf_uprobe_multi_link_lops, prog);
3389
3390 for (i = 0; i < cnt; i++) {
3391 uprobes[i].uprobe = uprobe_register(d_real_inode(link->path.dentry),
3392 uprobes[i].offset,
3393 uprobes[i].ref_ctr_offset,
3394 &uprobes[i].consumer);
3395 if (IS_ERR(uprobes[i].uprobe)) {
3396 err = PTR_ERR(uprobes[i].uprobe);
3397 link->cnt = i;
3398 goto error_unregister;
3399 }
3400 }
3401
3402 err = bpf_link_prime(&link->link, &link_primer);
3403 if (err)
3404 goto error_unregister;
3405
3406 return bpf_link_settle(&link_primer);
3407
3408 error_unregister:
3409 bpf_uprobe_unregister(uprobes, link->cnt);
3410
3411 error_free:
3412 kvfree(uprobes);
3413 kfree(link);
3414 if (task)
3415 put_task_struct(task);
3416 error_path_put:
3417 path_put(&path);
3418 return err;
3419 }
3420 #else /* !CONFIG_UPROBES */
bpf_uprobe_multi_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)3421 int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
3422 {
3423 return -EOPNOTSUPP;
3424 }
bpf_uprobe_multi_cookie(struct bpf_run_ctx * ctx)3425 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx)
3426 {
3427 return 0;
3428 }
bpf_uprobe_multi_entry_ip(struct bpf_run_ctx * ctx)3429 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
3430 {
3431 return 0;
3432 }
3433 #endif /* CONFIG_UPROBES */
3434
3435 __bpf_kfunc_start_defs();
3436
bpf_session_is_return(void)3437 __bpf_kfunc bool bpf_session_is_return(void)
3438 {
3439 struct bpf_session_run_ctx *session_ctx;
3440
3441 session_ctx = container_of(current->bpf_ctx, struct bpf_session_run_ctx, run_ctx);
3442 return session_ctx->is_return;
3443 }
3444
bpf_session_cookie(void)3445 __bpf_kfunc __u64 *bpf_session_cookie(void)
3446 {
3447 struct bpf_session_run_ctx *session_ctx;
3448
3449 session_ctx = container_of(current->bpf_ctx, struct bpf_session_run_ctx, run_ctx);
3450 return session_ctx->data;
3451 }
3452
3453 __bpf_kfunc_end_defs();
3454
3455 BTF_KFUNCS_START(kprobe_multi_kfunc_set_ids)
BTF_ID_FLAGS(func,bpf_session_is_return)3456 BTF_ID_FLAGS(func, bpf_session_is_return)
3457 BTF_ID_FLAGS(func, bpf_session_cookie)
3458 BTF_KFUNCS_END(kprobe_multi_kfunc_set_ids)
3459
3460 static int bpf_kprobe_multi_filter(const struct bpf_prog *prog, u32 kfunc_id)
3461 {
3462 if (!btf_id_set8_contains(&kprobe_multi_kfunc_set_ids, kfunc_id))
3463 return 0;
3464
3465 if (!is_kprobe_session(prog))
3466 return -EACCES;
3467
3468 return 0;
3469 }
3470
3471 static const struct btf_kfunc_id_set bpf_kprobe_multi_kfunc_set = {
3472 .owner = THIS_MODULE,
3473 .set = &kprobe_multi_kfunc_set_ids,
3474 .filter = bpf_kprobe_multi_filter,
3475 };
3476
bpf_kprobe_multi_kfuncs_init(void)3477 static int __init bpf_kprobe_multi_kfuncs_init(void)
3478 {
3479 return register_btf_kfunc_id_set(BPF_PROG_TYPE_KPROBE, &bpf_kprobe_multi_kfunc_set);
3480 }
3481
3482 late_initcall(bpf_kprobe_multi_kfuncs_init);
3483