1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2011-2015 PLUMgrid, http://plumgrid.com
3 * Copyright (c) 2016 Facebook
4 */
5 #include <linux/kernel.h>
6 #include <linux/types.h>
7 #include <linux/slab.h>
8 #include <linux/bpf.h>
9 #include <linux/bpf_verifier.h>
10 #include <linux/bpf_perf_event.h>
11 #include <linux/btf.h>
12 #include <linux/filter.h>
13 #include <linux/uaccess.h>
14 #include <linux/ctype.h>
15 #include <linux/kprobes.h>
16 #include <linux/spinlock.h>
17 #include <linux/syscalls.h>
18 #include <linux/error-injection.h>
19 #include <linux/btf_ids.h>
20 #include <linux/bpf_lsm.h>
21 #include <linux/fprobe.h>
22 #include <linux/bsearch.h>
23 #include <linux/sort.h>
24 #include <linux/key.h>
25 #include <linux/verification.h>
26 #include <linux/namei.h>
27
28 #include <net/bpf_sk_storage.h>
29
30 #include <uapi/linux/bpf.h>
31 #include <uapi/linux/btf.h>
32
33 #include <asm/tlb.h>
34
35 #include "trace_probe.h"
36 #include "trace.h"
37
38 #define CREATE_TRACE_POINTS
39 #include "bpf_trace.h"
40
41 #define bpf_event_rcu_dereference(p) \
42 rcu_dereference_protected(p, lockdep_is_held(&bpf_event_mutex))
43
44 #define MAX_UPROBE_MULTI_CNT (1U << 20)
45 #define MAX_KPROBE_MULTI_CNT (1U << 20)
46
47 #ifdef CONFIG_MODULES
48 struct bpf_trace_module {
49 struct module *module;
50 struct list_head list;
51 };
52
53 static LIST_HEAD(bpf_trace_modules);
54 static DEFINE_MUTEX(bpf_module_mutex);
55
bpf_get_raw_tracepoint_module(const char * name)56 static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name)
57 {
58 struct bpf_raw_event_map *btp, *ret = NULL;
59 struct bpf_trace_module *btm;
60 unsigned int i;
61
62 mutex_lock(&bpf_module_mutex);
63 list_for_each_entry(btm, &bpf_trace_modules, list) {
64 for (i = 0; i < btm->module->num_bpf_raw_events; ++i) {
65 btp = &btm->module->bpf_raw_events[i];
66 if (!strcmp(btp->tp->name, name)) {
67 if (try_module_get(btm->module))
68 ret = btp;
69 goto out;
70 }
71 }
72 }
73 out:
74 mutex_unlock(&bpf_module_mutex);
75 return ret;
76 }
77 #else
bpf_get_raw_tracepoint_module(const char * name)78 static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name)
79 {
80 return NULL;
81 }
82 #endif /* CONFIG_MODULES */
83
84 u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
85 u64 bpf_get_stack(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
86
87 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size,
88 u64 flags, const struct btf **btf,
89 s32 *btf_id);
90 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx);
91 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx);
92
93 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx);
94 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx);
95
96 /**
97 * trace_call_bpf - invoke BPF program
98 * @call: tracepoint event
99 * @ctx: opaque context pointer
100 *
101 * kprobe handlers execute BPF programs via this helper.
102 * Can be used from static tracepoints in the future.
103 *
104 * Return: BPF programs always return an integer which is interpreted by
105 * kprobe handler as:
106 * 0 - return from kprobe (event is filtered out)
107 * 1 - store kprobe event into ring buffer
108 * Other values are reserved and currently alias to 1
109 */
trace_call_bpf(struct trace_event_call * call,void * ctx)110 unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx)
111 {
112 unsigned int ret;
113
114 cant_sleep();
115
116 if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) {
117 /*
118 * since some bpf program is already running on this cpu,
119 * don't call into another bpf program (same or different)
120 * and don't send kprobe event into ring-buffer,
121 * so return zero here
122 */
123 rcu_read_lock();
124 bpf_prog_inc_misses_counters(rcu_dereference(call->prog_array));
125 rcu_read_unlock();
126 ret = 0;
127 goto out;
128 }
129
130 /*
131 * Instead of moving rcu_read_lock/rcu_dereference/rcu_read_unlock
132 * to all call sites, we did a bpf_prog_array_valid() there to check
133 * whether call->prog_array is empty or not, which is
134 * a heuristic to speed up execution.
135 *
136 * If bpf_prog_array_valid() fetched prog_array was
137 * non-NULL, we go into trace_call_bpf() and do the actual
138 * proper rcu_dereference() under RCU lock.
139 * If it turns out that prog_array is NULL then, we bail out.
140 * For the opposite, if the bpf_prog_array_valid() fetched pointer
141 * was NULL, you'll skip the prog_array with the risk of missing
142 * out of events when it was updated in between this and the
143 * rcu_dereference() which is accepted risk.
144 */
145 rcu_read_lock();
146 ret = bpf_prog_run_array(rcu_dereference(call->prog_array),
147 ctx, bpf_prog_run);
148 rcu_read_unlock();
149
150 out:
151 __this_cpu_dec(bpf_prog_active);
152
153 return ret;
154 }
155
156 #ifdef CONFIG_BPF_KPROBE_OVERRIDE
BPF_CALL_2(bpf_override_return,struct pt_regs *,regs,unsigned long,rc)157 BPF_CALL_2(bpf_override_return, struct pt_regs *, regs, unsigned long, rc)
158 {
159 regs_set_return_value(regs, rc);
160 override_function_with_return(regs);
161 return 0;
162 }
163
164 static const struct bpf_func_proto bpf_override_return_proto = {
165 .func = bpf_override_return,
166 .gpl_only = true,
167 .ret_type = RET_INTEGER,
168 .arg1_type = ARG_PTR_TO_CTX,
169 .arg2_type = ARG_ANYTHING,
170 };
171 #endif
172
173 static __always_inline int
bpf_probe_read_user_common(void * dst,u32 size,const void __user * unsafe_ptr)174 bpf_probe_read_user_common(void *dst, u32 size, const void __user *unsafe_ptr)
175 {
176 int ret;
177
178 ret = copy_from_user_nofault(dst, unsafe_ptr, size);
179 if (unlikely(ret < 0))
180 memset(dst, 0, size);
181 return ret;
182 }
183
BPF_CALL_3(bpf_probe_read_user,void *,dst,u32,size,const void __user *,unsafe_ptr)184 BPF_CALL_3(bpf_probe_read_user, void *, dst, u32, size,
185 const void __user *, unsafe_ptr)
186 {
187 return bpf_probe_read_user_common(dst, size, unsafe_ptr);
188 }
189
190 const struct bpf_func_proto bpf_probe_read_user_proto = {
191 .func = bpf_probe_read_user,
192 .gpl_only = true,
193 .ret_type = RET_INTEGER,
194 .arg1_type = ARG_PTR_TO_UNINIT_MEM,
195 .arg2_type = ARG_CONST_SIZE_OR_ZERO,
196 .arg3_type = ARG_ANYTHING,
197 };
198
199 static __always_inline int
bpf_probe_read_user_str_common(void * dst,u32 size,const void __user * unsafe_ptr)200 bpf_probe_read_user_str_common(void *dst, u32 size,
201 const void __user *unsafe_ptr)
202 {
203 int ret;
204
205 /*
206 * NB: We rely on strncpy_from_user() not copying junk past the NUL
207 * terminator into `dst`.
208 *
209 * strncpy_from_user() does long-sized strides in the fast path. If the
210 * strncpy does not mask out the bytes after the NUL in `unsafe_ptr`,
211 * then there could be junk after the NUL in `dst`. If user takes `dst`
212 * and keys a hash map with it, then semantically identical strings can
213 * occupy multiple entries in the map.
214 */
215 ret = strncpy_from_user_nofault(dst, unsafe_ptr, size);
216 if (unlikely(ret < 0))
217 memset(dst, 0, size);
218 return ret;
219 }
220
BPF_CALL_3(bpf_probe_read_user_str,void *,dst,u32,size,const void __user *,unsafe_ptr)221 BPF_CALL_3(bpf_probe_read_user_str, void *, dst, u32, size,
222 const void __user *, unsafe_ptr)
223 {
224 return bpf_probe_read_user_str_common(dst, size, unsafe_ptr);
225 }
226
227 const struct bpf_func_proto bpf_probe_read_user_str_proto = {
228 .func = bpf_probe_read_user_str,
229 .gpl_only = true,
230 .ret_type = RET_INTEGER,
231 .arg1_type = ARG_PTR_TO_UNINIT_MEM,
232 .arg2_type = ARG_CONST_SIZE_OR_ZERO,
233 .arg3_type = ARG_ANYTHING,
234 };
235
BPF_CALL_3(bpf_probe_read_kernel,void *,dst,u32,size,const void *,unsafe_ptr)236 BPF_CALL_3(bpf_probe_read_kernel, void *, dst, u32, size,
237 const void *, unsafe_ptr)
238 {
239 return bpf_probe_read_kernel_common(dst, size, unsafe_ptr);
240 }
241
242 const struct bpf_func_proto bpf_probe_read_kernel_proto = {
243 .func = bpf_probe_read_kernel,
244 .gpl_only = true,
245 .ret_type = RET_INTEGER,
246 .arg1_type = ARG_PTR_TO_UNINIT_MEM,
247 .arg2_type = ARG_CONST_SIZE_OR_ZERO,
248 .arg3_type = ARG_ANYTHING,
249 };
250
251 static __always_inline int
bpf_probe_read_kernel_str_common(void * dst,u32 size,const void * unsafe_ptr)252 bpf_probe_read_kernel_str_common(void *dst, u32 size, const void *unsafe_ptr)
253 {
254 int ret;
255
256 /*
257 * The strncpy_from_kernel_nofault() call will likely not fill the
258 * entire buffer, but that's okay in this circumstance as we're probing
259 * arbitrary memory anyway similar to bpf_probe_read_*() and might
260 * as well probe the stack. Thus, memory is explicitly cleared
261 * only in error case, so that improper users ignoring return
262 * code altogether don't copy garbage; otherwise length of string
263 * is returned that can be used for bpf_perf_event_output() et al.
264 */
265 ret = strncpy_from_kernel_nofault(dst, unsafe_ptr, size);
266 if (unlikely(ret < 0))
267 memset(dst, 0, size);
268 return ret;
269 }
270
BPF_CALL_3(bpf_probe_read_kernel_str,void *,dst,u32,size,const void *,unsafe_ptr)271 BPF_CALL_3(bpf_probe_read_kernel_str, void *, dst, u32, size,
272 const void *, unsafe_ptr)
273 {
274 return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr);
275 }
276
277 const struct bpf_func_proto bpf_probe_read_kernel_str_proto = {
278 .func = bpf_probe_read_kernel_str,
279 .gpl_only = true,
280 .ret_type = RET_INTEGER,
281 .arg1_type = ARG_PTR_TO_UNINIT_MEM,
282 .arg2_type = ARG_CONST_SIZE_OR_ZERO,
283 .arg3_type = ARG_ANYTHING,
284 };
285
286 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
BPF_CALL_3(bpf_probe_read_compat,void *,dst,u32,size,const void *,unsafe_ptr)287 BPF_CALL_3(bpf_probe_read_compat, void *, dst, u32, size,
288 const void *, unsafe_ptr)
289 {
290 if ((unsigned long)unsafe_ptr < TASK_SIZE) {
291 return bpf_probe_read_user_common(dst, size,
292 (__force void __user *)unsafe_ptr);
293 }
294 return bpf_probe_read_kernel_common(dst, size, unsafe_ptr);
295 }
296
297 static const struct bpf_func_proto bpf_probe_read_compat_proto = {
298 .func = bpf_probe_read_compat,
299 .gpl_only = true,
300 .ret_type = RET_INTEGER,
301 .arg1_type = ARG_PTR_TO_UNINIT_MEM,
302 .arg2_type = ARG_CONST_SIZE_OR_ZERO,
303 .arg3_type = ARG_ANYTHING,
304 };
305
BPF_CALL_3(bpf_probe_read_compat_str,void *,dst,u32,size,const void *,unsafe_ptr)306 BPF_CALL_3(bpf_probe_read_compat_str, void *, dst, u32, size,
307 const void *, unsafe_ptr)
308 {
309 if ((unsigned long)unsafe_ptr < TASK_SIZE) {
310 return bpf_probe_read_user_str_common(dst, size,
311 (__force void __user *)unsafe_ptr);
312 }
313 return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr);
314 }
315
316 static const struct bpf_func_proto bpf_probe_read_compat_str_proto = {
317 .func = bpf_probe_read_compat_str,
318 .gpl_only = true,
319 .ret_type = RET_INTEGER,
320 .arg1_type = ARG_PTR_TO_UNINIT_MEM,
321 .arg2_type = ARG_CONST_SIZE_OR_ZERO,
322 .arg3_type = ARG_ANYTHING,
323 };
324 #endif /* CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE */
325
BPF_CALL_3(bpf_probe_write_user,void __user *,unsafe_ptr,const void *,src,u32,size)326 BPF_CALL_3(bpf_probe_write_user, void __user *, unsafe_ptr, const void *, src,
327 u32, size)
328 {
329 /*
330 * Ensure we're in user context which is safe for the helper to
331 * run. This helper has no business in a kthread.
332 *
333 * access_ok() should prevent writing to non-user memory, but in
334 * some situations (nommu, temporary switch, etc) access_ok() does
335 * not provide enough validation, hence the check on KERNEL_DS.
336 *
337 * nmi_uaccess_okay() ensures the probe is not run in an interim
338 * state, when the task or mm are switched. This is specifically
339 * required to prevent the use of temporary mm.
340 */
341
342 if (unlikely(in_interrupt() ||
343 current->flags & (PF_KTHREAD | PF_EXITING)))
344 return -EPERM;
345 if (unlikely(!nmi_uaccess_okay()))
346 return -EPERM;
347
348 return copy_to_user_nofault(unsafe_ptr, src, size);
349 }
350
351 static const struct bpf_func_proto bpf_probe_write_user_proto = {
352 .func = bpf_probe_write_user,
353 .gpl_only = true,
354 .ret_type = RET_INTEGER,
355 .arg1_type = ARG_ANYTHING,
356 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
357 .arg3_type = ARG_CONST_SIZE,
358 };
359
360 #define MAX_TRACE_PRINTK_VARARGS 3
361 #define BPF_TRACE_PRINTK_SIZE 1024
362
BPF_CALL_5(bpf_trace_printk,char *,fmt,u32,fmt_size,u64,arg1,u64,arg2,u64,arg3)363 BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1,
364 u64, arg2, u64, arg3)
365 {
366 u64 args[MAX_TRACE_PRINTK_VARARGS] = { arg1, arg2, arg3 };
367 struct bpf_bprintf_data data = {
368 .get_bin_args = true,
369 .get_buf = true,
370 };
371 int ret;
372
373 ret = bpf_bprintf_prepare(fmt, fmt_size, args,
374 MAX_TRACE_PRINTK_VARARGS, &data);
375 if (ret < 0)
376 return ret;
377
378 ret = bstr_printf(data.buf, MAX_BPRINTF_BUF, fmt, data.bin_args);
379
380 trace_bpf_trace_printk(data.buf);
381
382 bpf_bprintf_cleanup(&data);
383
384 return ret;
385 }
386
387 static const struct bpf_func_proto bpf_trace_printk_proto = {
388 .func = bpf_trace_printk,
389 .gpl_only = true,
390 .ret_type = RET_INTEGER,
391 .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY,
392 .arg2_type = ARG_CONST_SIZE,
393 };
394
__set_printk_clr_event(void)395 static void __set_printk_clr_event(void)
396 {
397 /*
398 * This program might be calling bpf_trace_printk,
399 * so enable the associated bpf_trace/bpf_trace_printk event.
400 * Repeat this each time as it is possible a user has
401 * disabled bpf_trace_printk events. By loading a program
402 * calling bpf_trace_printk() however the user has expressed
403 * the intent to see such events.
404 */
405 if (trace_set_clr_event("bpf_trace", "bpf_trace_printk", 1))
406 pr_warn_ratelimited("could not enable bpf_trace_printk events");
407 }
408
bpf_get_trace_printk_proto(void)409 const struct bpf_func_proto *bpf_get_trace_printk_proto(void)
410 {
411 __set_printk_clr_event();
412 return &bpf_trace_printk_proto;
413 }
414
BPF_CALL_4(bpf_trace_vprintk,char *,fmt,u32,fmt_size,const void *,args,u32,data_len)415 BPF_CALL_4(bpf_trace_vprintk, char *, fmt, u32, fmt_size, const void *, args,
416 u32, data_len)
417 {
418 struct bpf_bprintf_data data = {
419 .get_bin_args = true,
420 .get_buf = true,
421 };
422 int ret, num_args;
423
424 if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 ||
425 (data_len && !args))
426 return -EINVAL;
427 num_args = data_len / 8;
428
429 ret = bpf_bprintf_prepare(fmt, fmt_size, args, num_args, &data);
430 if (ret < 0)
431 return ret;
432
433 ret = bstr_printf(data.buf, MAX_BPRINTF_BUF, fmt, data.bin_args);
434
435 trace_bpf_trace_printk(data.buf);
436
437 bpf_bprintf_cleanup(&data);
438
439 return ret;
440 }
441
442 static const struct bpf_func_proto bpf_trace_vprintk_proto = {
443 .func = bpf_trace_vprintk,
444 .gpl_only = true,
445 .ret_type = RET_INTEGER,
446 .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY,
447 .arg2_type = ARG_CONST_SIZE,
448 .arg3_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY,
449 .arg4_type = ARG_CONST_SIZE_OR_ZERO,
450 };
451
bpf_get_trace_vprintk_proto(void)452 const struct bpf_func_proto *bpf_get_trace_vprintk_proto(void)
453 {
454 __set_printk_clr_event();
455 return &bpf_trace_vprintk_proto;
456 }
457
BPF_CALL_5(bpf_seq_printf,struct seq_file *,m,char *,fmt,u32,fmt_size,const void *,args,u32,data_len)458 BPF_CALL_5(bpf_seq_printf, struct seq_file *, m, char *, fmt, u32, fmt_size,
459 const void *, args, u32, data_len)
460 {
461 struct bpf_bprintf_data data = {
462 .get_bin_args = true,
463 };
464 int err, num_args;
465
466 if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 ||
467 (data_len && !args))
468 return -EINVAL;
469 num_args = data_len / 8;
470
471 err = bpf_bprintf_prepare(fmt, fmt_size, args, num_args, &data);
472 if (err < 0)
473 return err;
474
475 seq_bprintf(m, fmt, data.bin_args);
476
477 bpf_bprintf_cleanup(&data);
478
479 return seq_has_overflowed(m) ? -EOVERFLOW : 0;
480 }
481
482 BTF_ID_LIST_SINGLE(btf_seq_file_ids, struct, seq_file)
483
484 static const struct bpf_func_proto bpf_seq_printf_proto = {
485 .func = bpf_seq_printf,
486 .gpl_only = true,
487 .ret_type = RET_INTEGER,
488 .arg1_type = ARG_PTR_TO_BTF_ID,
489 .arg1_btf_id = &btf_seq_file_ids[0],
490 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
491 .arg3_type = ARG_CONST_SIZE,
492 .arg4_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY,
493 .arg5_type = ARG_CONST_SIZE_OR_ZERO,
494 };
495
BPF_CALL_3(bpf_seq_write,struct seq_file *,m,const void *,data,u32,len)496 BPF_CALL_3(bpf_seq_write, struct seq_file *, m, const void *, data, u32, len)
497 {
498 return seq_write(m, data, len) ? -EOVERFLOW : 0;
499 }
500
501 static const struct bpf_func_proto bpf_seq_write_proto = {
502 .func = bpf_seq_write,
503 .gpl_only = true,
504 .ret_type = RET_INTEGER,
505 .arg1_type = ARG_PTR_TO_BTF_ID,
506 .arg1_btf_id = &btf_seq_file_ids[0],
507 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
508 .arg3_type = ARG_CONST_SIZE_OR_ZERO,
509 };
510
BPF_CALL_4(bpf_seq_printf_btf,struct seq_file *,m,struct btf_ptr *,ptr,u32,btf_ptr_size,u64,flags)511 BPF_CALL_4(bpf_seq_printf_btf, struct seq_file *, m, struct btf_ptr *, ptr,
512 u32, btf_ptr_size, u64, flags)
513 {
514 const struct btf *btf;
515 s32 btf_id;
516 int ret;
517
518 ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id);
519 if (ret)
520 return ret;
521
522 return btf_type_seq_show_flags(btf, btf_id, ptr->ptr, m, flags);
523 }
524
525 static const struct bpf_func_proto bpf_seq_printf_btf_proto = {
526 .func = bpf_seq_printf_btf,
527 .gpl_only = true,
528 .ret_type = RET_INTEGER,
529 .arg1_type = ARG_PTR_TO_BTF_ID,
530 .arg1_btf_id = &btf_seq_file_ids[0],
531 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
532 .arg3_type = ARG_CONST_SIZE_OR_ZERO,
533 .arg4_type = ARG_ANYTHING,
534 };
535
536 static __always_inline int
get_map_perf_counter(struct bpf_map * map,u64 flags,u64 * value,u64 * enabled,u64 * running)537 get_map_perf_counter(struct bpf_map *map, u64 flags,
538 u64 *value, u64 *enabled, u64 *running)
539 {
540 struct bpf_array *array = container_of(map, struct bpf_array, map);
541 unsigned int cpu = smp_processor_id();
542 u64 index = flags & BPF_F_INDEX_MASK;
543 struct bpf_event_entry *ee;
544
545 if (unlikely(flags & ~(BPF_F_INDEX_MASK)))
546 return -EINVAL;
547 if (index == BPF_F_CURRENT_CPU)
548 index = cpu;
549 if (unlikely(index >= array->map.max_entries))
550 return -E2BIG;
551
552 ee = READ_ONCE(array->ptrs[index]);
553 if (!ee)
554 return -ENOENT;
555
556 return perf_event_read_local(ee->event, value, enabled, running);
557 }
558
BPF_CALL_2(bpf_perf_event_read,struct bpf_map *,map,u64,flags)559 BPF_CALL_2(bpf_perf_event_read, struct bpf_map *, map, u64, flags)
560 {
561 u64 value = 0;
562 int err;
563
564 err = get_map_perf_counter(map, flags, &value, NULL, NULL);
565 /*
566 * this api is ugly since we miss [-22..-2] range of valid
567 * counter values, but that's uapi
568 */
569 if (err)
570 return err;
571 return value;
572 }
573
574 static const struct bpf_func_proto bpf_perf_event_read_proto = {
575 .func = bpf_perf_event_read,
576 .gpl_only = true,
577 .ret_type = RET_INTEGER,
578 .arg1_type = ARG_CONST_MAP_PTR,
579 .arg2_type = ARG_ANYTHING,
580 };
581
BPF_CALL_4(bpf_perf_event_read_value,struct bpf_map *,map,u64,flags,struct bpf_perf_event_value *,buf,u32,size)582 BPF_CALL_4(bpf_perf_event_read_value, struct bpf_map *, map, u64, flags,
583 struct bpf_perf_event_value *, buf, u32, size)
584 {
585 int err = -EINVAL;
586
587 if (unlikely(size != sizeof(struct bpf_perf_event_value)))
588 goto clear;
589 err = get_map_perf_counter(map, flags, &buf->counter, &buf->enabled,
590 &buf->running);
591 if (unlikely(err))
592 goto clear;
593 return 0;
594 clear:
595 memset(buf, 0, size);
596 return err;
597 }
598
599 static const struct bpf_func_proto bpf_perf_event_read_value_proto = {
600 .func = bpf_perf_event_read_value,
601 .gpl_only = true,
602 .ret_type = RET_INTEGER,
603 .arg1_type = ARG_CONST_MAP_PTR,
604 .arg2_type = ARG_ANYTHING,
605 .arg3_type = ARG_PTR_TO_UNINIT_MEM,
606 .arg4_type = ARG_CONST_SIZE,
607 };
608
609 static __always_inline u64
__bpf_perf_event_output(struct pt_regs * regs,struct bpf_map * map,u64 flags,struct perf_raw_record * raw,struct perf_sample_data * sd)610 __bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map,
611 u64 flags, struct perf_raw_record *raw,
612 struct perf_sample_data *sd)
613 {
614 struct bpf_array *array = container_of(map, struct bpf_array, map);
615 unsigned int cpu = smp_processor_id();
616 u64 index = flags & BPF_F_INDEX_MASK;
617 struct bpf_event_entry *ee;
618 struct perf_event *event;
619
620 if (index == BPF_F_CURRENT_CPU)
621 index = cpu;
622 if (unlikely(index >= array->map.max_entries))
623 return -E2BIG;
624
625 ee = READ_ONCE(array->ptrs[index]);
626 if (!ee)
627 return -ENOENT;
628
629 event = ee->event;
630 if (unlikely(event->attr.type != PERF_TYPE_SOFTWARE ||
631 event->attr.config != PERF_COUNT_SW_BPF_OUTPUT))
632 return -EINVAL;
633
634 if (unlikely(event->oncpu != cpu))
635 return -EOPNOTSUPP;
636
637 perf_sample_save_raw_data(sd, event, raw);
638
639 return perf_event_output(event, sd, regs);
640 }
641
642 /*
643 * Support executing tracepoints in normal, irq, and nmi context that each call
644 * bpf_perf_event_output
645 */
646 struct bpf_trace_sample_data {
647 struct perf_sample_data sds[3];
648 };
649
650 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_trace_sds);
651 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)652 BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map,
653 u64, flags, void *, data, u64, size)
654 {
655 struct bpf_trace_sample_data *sds;
656 struct perf_raw_record raw = {
657 .frag = {
658 .size = size,
659 .data = data,
660 },
661 };
662 struct perf_sample_data *sd;
663 int nest_level, err;
664
665 preempt_disable();
666 sds = this_cpu_ptr(&bpf_trace_sds);
667 nest_level = this_cpu_inc_return(bpf_trace_nest_level);
668
669 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(sds->sds))) {
670 err = -EBUSY;
671 goto out;
672 }
673
674 sd = &sds->sds[nest_level - 1];
675
676 if (unlikely(flags & ~(BPF_F_INDEX_MASK))) {
677 err = -EINVAL;
678 goto out;
679 }
680
681 perf_sample_data_init(sd, 0, 0);
682
683 err = __bpf_perf_event_output(regs, map, flags, &raw, sd);
684 out:
685 this_cpu_dec(bpf_trace_nest_level);
686 preempt_enable();
687 return err;
688 }
689
690 static const struct bpf_func_proto bpf_perf_event_output_proto = {
691 .func = bpf_perf_event_output,
692 .gpl_only = true,
693 .ret_type = RET_INTEGER,
694 .arg1_type = ARG_PTR_TO_CTX,
695 .arg2_type = ARG_CONST_MAP_PTR,
696 .arg3_type = ARG_ANYTHING,
697 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY,
698 .arg5_type = ARG_CONST_SIZE_OR_ZERO,
699 };
700
701 static DEFINE_PER_CPU(int, bpf_event_output_nest_level);
702 struct bpf_nested_pt_regs {
703 struct pt_regs regs[3];
704 };
705 static DEFINE_PER_CPU(struct bpf_nested_pt_regs, bpf_pt_regs);
706 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_misc_sds);
707
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)708 u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
709 void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy)
710 {
711 struct perf_raw_frag frag = {
712 .copy = ctx_copy,
713 .size = ctx_size,
714 .data = ctx,
715 };
716 struct perf_raw_record raw = {
717 .frag = {
718 {
719 .next = ctx_size ? &frag : NULL,
720 },
721 .size = meta_size,
722 .data = meta,
723 },
724 };
725 struct perf_sample_data *sd;
726 struct pt_regs *regs;
727 int nest_level;
728 u64 ret;
729
730 preempt_disable();
731 nest_level = this_cpu_inc_return(bpf_event_output_nest_level);
732
733 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(bpf_misc_sds.sds))) {
734 ret = -EBUSY;
735 goto out;
736 }
737 sd = this_cpu_ptr(&bpf_misc_sds.sds[nest_level - 1]);
738 regs = this_cpu_ptr(&bpf_pt_regs.regs[nest_level - 1]);
739
740 perf_fetch_caller_regs(regs);
741 perf_sample_data_init(sd, 0, 0);
742
743 ret = __bpf_perf_event_output(regs, map, flags, &raw, sd);
744 out:
745 this_cpu_dec(bpf_event_output_nest_level);
746 preempt_enable();
747 return ret;
748 }
749
BPF_CALL_0(bpf_get_current_task)750 BPF_CALL_0(bpf_get_current_task)
751 {
752 return (long) current;
753 }
754
755 const struct bpf_func_proto bpf_get_current_task_proto = {
756 .func = bpf_get_current_task,
757 .gpl_only = true,
758 .ret_type = RET_INTEGER,
759 };
760
BPF_CALL_0(bpf_get_current_task_btf)761 BPF_CALL_0(bpf_get_current_task_btf)
762 {
763 return (unsigned long) current;
764 }
765
766 const struct bpf_func_proto bpf_get_current_task_btf_proto = {
767 .func = bpf_get_current_task_btf,
768 .gpl_only = true,
769 .ret_type = RET_PTR_TO_BTF_ID_TRUSTED,
770 .ret_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK],
771 };
772
BPF_CALL_1(bpf_task_pt_regs,struct task_struct *,task)773 BPF_CALL_1(bpf_task_pt_regs, struct task_struct *, task)
774 {
775 return (unsigned long) task_pt_regs(task);
776 }
777
778 BTF_ID_LIST(bpf_task_pt_regs_ids)
779 BTF_ID(struct, pt_regs)
780
781 const struct bpf_func_proto bpf_task_pt_regs_proto = {
782 .func = bpf_task_pt_regs,
783 .gpl_only = true,
784 .arg1_type = ARG_PTR_TO_BTF_ID,
785 .arg1_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK],
786 .ret_type = RET_PTR_TO_BTF_ID,
787 .ret_btf_id = &bpf_task_pt_regs_ids[0],
788 };
789
790 struct send_signal_irq_work {
791 struct irq_work irq_work;
792 struct task_struct *task;
793 u32 sig;
794 enum pid_type type;
795 bool has_siginfo;
796 struct kernel_siginfo info;
797 };
798
799 static DEFINE_PER_CPU(struct send_signal_irq_work, send_signal_work);
800
do_bpf_send_signal(struct irq_work * entry)801 static void do_bpf_send_signal(struct irq_work *entry)
802 {
803 struct send_signal_irq_work *work;
804 struct kernel_siginfo *siginfo;
805
806 work = container_of(entry, struct send_signal_irq_work, irq_work);
807 siginfo = work->has_siginfo ? &work->info : SEND_SIG_PRIV;
808
809 group_send_sig_info(work->sig, siginfo, work->task, work->type);
810 put_task_struct(work->task);
811 }
812
bpf_send_signal_common(u32 sig,enum pid_type type,struct task_struct * task,u64 value)813 static int bpf_send_signal_common(u32 sig, enum pid_type type, struct task_struct *task, u64 value)
814 {
815 struct send_signal_irq_work *work = NULL;
816 struct kernel_siginfo info;
817 struct kernel_siginfo *siginfo;
818
819 if (!task) {
820 task = current;
821 siginfo = SEND_SIG_PRIV;
822 } else {
823 clear_siginfo(&info);
824 info.si_signo = sig;
825 info.si_errno = 0;
826 info.si_code = SI_KERNEL;
827 info.si_pid = 0;
828 info.si_uid = 0;
829 info.si_value.sival_ptr = (void *)(unsigned long)value;
830 siginfo = &info;
831 }
832
833 /* Similar to bpf_probe_write_user, task needs to be
834 * in a sound condition and kernel memory access be
835 * permitted in order to send signal to the current
836 * task.
837 */
838 if (unlikely(task->flags & (PF_KTHREAD | PF_EXITING)))
839 return -EPERM;
840 if (unlikely(!nmi_uaccess_okay()))
841 return -EPERM;
842 /* Task should not be pid=1 to avoid kernel panic. */
843 if (unlikely(is_global_init(task)))
844 return -EPERM;
845
846 if (!preemptible()) {
847 /* Do an early check on signal validity. Otherwise,
848 * the error is lost in deferred irq_work.
849 */
850 if (unlikely(!valid_signal(sig)))
851 return -EINVAL;
852
853 work = this_cpu_ptr(&send_signal_work);
854 if (irq_work_is_busy(&work->irq_work))
855 return -EBUSY;
856
857 /* Add the current task, which is the target of sending signal,
858 * to the irq_work. The current task may change when queued
859 * irq works get executed.
860 */
861 work->task = get_task_struct(task);
862 work->has_siginfo = siginfo == &info;
863 if (work->has_siginfo)
864 copy_siginfo(&work->info, &info);
865 work->sig = sig;
866 work->type = type;
867 irq_work_queue(&work->irq_work);
868 return 0;
869 }
870
871 return group_send_sig_info(sig, siginfo, task, type);
872 }
873
BPF_CALL_1(bpf_send_signal,u32,sig)874 BPF_CALL_1(bpf_send_signal, u32, sig)
875 {
876 return bpf_send_signal_common(sig, PIDTYPE_TGID, NULL, 0);
877 }
878
879 static const struct bpf_func_proto bpf_send_signal_proto = {
880 .func = bpf_send_signal,
881 .gpl_only = false,
882 .ret_type = RET_INTEGER,
883 .arg1_type = ARG_ANYTHING,
884 };
885
BPF_CALL_1(bpf_send_signal_thread,u32,sig)886 BPF_CALL_1(bpf_send_signal_thread, u32, sig)
887 {
888 return bpf_send_signal_common(sig, PIDTYPE_PID, NULL, 0);
889 }
890
891 static const struct bpf_func_proto bpf_send_signal_thread_proto = {
892 .func = bpf_send_signal_thread,
893 .gpl_only = false,
894 .ret_type = RET_INTEGER,
895 .arg1_type = ARG_ANYTHING,
896 };
897
BPF_CALL_3(bpf_d_path,struct path *,path,char *,buf,u32,sz)898 BPF_CALL_3(bpf_d_path, struct path *, path, char *, buf, u32, sz)
899 {
900 struct path copy;
901 long len;
902 char *p;
903
904 if (!sz)
905 return 0;
906
907 /*
908 * The path pointer is verified as trusted and safe to use,
909 * but let's double check it's valid anyway to workaround
910 * potentially broken verifier.
911 */
912 len = copy_from_kernel_nofault(©, path, sizeof(*path));
913 if (len < 0)
914 return len;
915
916 p = d_path(©, buf, sz);
917 if (IS_ERR(p)) {
918 len = PTR_ERR(p);
919 } else {
920 len = buf + sz - p;
921 memmove(buf, p, len);
922 }
923
924 return len;
925 }
926
927 BTF_SET_START(btf_allowlist_d_path)
928 #ifdef CONFIG_SECURITY
BTF_ID(func,security_file_permission)929 BTF_ID(func, security_file_permission)
930 BTF_ID(func, security_inode_getattr)
931 BTF_ID(func, security_file_open)
932 #endif
933 #ifdef CONFIG_SECURITY_PATH
934 BTF_ID(func, security_path_truncate)
935 #endif
936 BTF_ID(func, vfs_truncate)
937 BTF_ID(func, vfs_fallocate)
938 BTF_ID(func, dentry_open)
939 BTF_ID(func, vfs_getattr)
940 BTF_ID(func, filp_close)
941 BTF_SET_END(btf_allowlist_d_path)
942
943 static bool bpf_d_path_allowed(const struct bpf_prog *prog)
944 {
945 if (prog->type == BPF_PROG_TYPE_TRACING &&
946 prog->expected_attach_type == BPF_TRACE_ITER)
947 return true;
948
949 if (prog->type == BPF_PROG_TYPE_LSM)
950 return bpf_lsm_is_sleepable_hook(prog->aux->attach_btf_id);
951
952 return btf_id_set_contains(&btf_allowlist_d_path,
953 prog->aux->attach_btf_id);
954 }
955
956 BTF_ID_LIST_SINGLE(bpf_d_path_btf_ids, struct, path)
957
958 static const struct bpf_func_proto bpf_d_path_proto = {
959 .func = bpf_d_path,
960 .gpl_only = false,
961 .ret_type = RET_INTEGER,
962 .arg1_type = ARG_PTR_TO_BTF_ID,
963 .arg1_btf_id = &bpf_d_path_btf_ids[0],
964 .arg2_type = ARG_PTR_TO_MEM,
965 .arg3_type = ARG_CONST_SIZE_OR_ZERO,
966 .allowed = bpf_d_path_allowed,
967 };
968
969 #define BTF_F_ALL (BTF_F_COMPACT | BTF_F_NONAME | \
970 BTF_F_PTR_RAW | BTF_F_ZERO)
971
bpf_btf_printf_prepare(struct btf_ptr * ptr,u32 btf_ptr_size,u64 flags,const struct btf ** btf,s32 * btf_id)972 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size,
973 u64 flags, const struct btf **btf,
974 s32 *btf_id)
975 {
976 const struct btf_type *t;
977
978 if (unlikely(flags & ~(BTF_F_ALL)))
979 return -EINVAL;
980
981 if (btf_ptr_size != sizeof(struct btf_ptr))
982 return -EINVAL;
983
984 *btf = bpf_get_btf_vmlinux();
985
986 if (IS_ERR_OR_NULL(*btf))
987 return IS_ERR(*btf) ? PTR_ERR(*btf) : -EINVAL;
988
989 if (ptr->type_id > 0)
990 *btf_id = ptr->type_id;
991 else
992 return -EINVAL;
993
994 if (*btf_id > 0)
995 t = btf_type_by_id(*btf, *btf_id);
996 if (*btf_id <= 0 || !t)
997 return -ENOENT;
998
999 return 0;
1000 }
1001
BPF_CALL_5(bpf_snprintf_btf,char *,str,u32,str_size,struct btf_ptr *,ptr,u32,btf_ptr_size,u64,flags)1002 BPF_CALL_5(bpf_snprintf_btf, char *, str, u32, str_size, struct btf_ptr *, ptr,
1003 u32, btf_ptr_size, u64, flags)
1004 {
1005 const struct btf *btf;
1006 s32 btf_id;
1007 int ret;
1008
1009 ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id);
1010 if (ret)
1011 return ret;
1012
1013 return btf_type_snprintf_show(btf, btf_id, ptr->ptr, str, str_size,
1014 flags);
1015 }
1016
1017 const struct bpf_func_proto bpf_snprintf_btf_proto = {
1018 .func = bpf_snprintf_btf,
1019 .gpl_only = false,
1020 .ret_type = RET_INTEGER,
1021 .arg1_type = ARG_PTR_TO_MEM,
1022 .arg2_type = ARG_CONST_SIZE,
1023 .arg3_type = ARG_PTR_TO_MEM | MEM_RDONLY,
1024 .arg4_type = ARG_CONST_SIZE,
1025 .arg5_type = ARG_ANYTHING,
1026 };
1027
BPF_CALL_1(bpf_get_func_ip_tracing,void *,ctx)1028 BPF_CALL_1(bpf_get_func_ip_tracing, void *, ctx)
1029 {
1030 /* This helper call is inlined by verifier. */
1031 return ((u64 *)ctx)[-2];
1032 }
1033
1034 static const struct bpf_func_proto bpf_get_func_ip_proto_tracing = {
1035 .func = bpf_get_func_ip_tracing,
1036 .gpl_only = true,
1037 .ret_type = RET_INTEGER,
1038 .arg1_type = ARG_PTR_TO_CTX,
1039 };
1040
1041 #ifdef CONFIG_X86_KERNEL_IBT
get_entry_ip(unsigned long fentry_ip)1042 static unsigned long get_entry_ip(unsigned long fentry_ip)
1043 {
1044 u32 instr;
1045
1046 /* We want to be extra safe in case entry ip is on the page edge,
1047 * but otherwise we need to avoid get_kernel_nofault()'s overhead.
1048 */
1049 if ((fentry_ip & ~PAGE_MASK) < ENDBR_INSN_SIZE) {
1050 if (get_kernel_nofault(instr, (u32 *)(fentry_ip - ENDBR_INSN_SIZE)))
1051 return fentry_ip;
1052 } else {
1053 instr = *(u32 *)(fentry_ip - ENDBR_INSN_SIZE);
1054 }
1055 if (is_endbr(instr))
1056 fentry_ip -= ENDBR_INSN_SIZE;
1057 return fentry_ip;
1058 }
1059 #else
1060 #define get_entry_ip(fentry_ip) fentry_ip
1061 #endif
1062
BPF_CALL_1(bpf_get_func_ip_kprobe,struct pt_regs *,regs)1063 BPF_CALL_1(bpf_get_func_ip_kprobe, struct pt_regs *, regs)
1064 {
1065 struct bpf_trace_run_ctx *run_ctx __maybe_unused;
1066 struct kprobe *kp;
1067
1068 #ifdef CONFIG_UPROBES
1069 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx);
1070 if (run_ctx->is_uprobe)
1071 return ((struct uprobe_dispatch_data *)current->utask->vaddr)->bp_addr;
1072 #endif
1073
1074 kp = kprobe_running();
1075
1076 if (!kp || !(kp->flags & KPROBE_FLAG_ON_FUNC_ENTRY))
1077 return 0;
1078
1079 return get_entry_ip((uintptr_t)kp->addr);
1080 }
1081
1082 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe = {
1083 .func = bpf_get_func_ip_kprobe,
1084 .gpl_only = true,
1085 .ret_type = RET_INTEGER,
1086 .arg1_type = ARG_PTR_TO_CTX,
1087 };
1088
BPF_CALL_1(bpf_get_func_ip_kprobe_multi,struct pt_regs *,regs)1089 BPF_CALL_1(bpf_get_func_ip_kprobe_multi, struct pt_regs *, regs)
1090 {
1091 return bpf_kprobe_multi_entry_ip(current->bpf_ctx);
1092 }
1093
1094 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe_multi = {
1095 .func = bpf_get_func_ip_kprobe_multi,
1096 .gpl_only = false,
1097 .ret_type = RET_INTEGER,
1098 .arg1_type = ARG_PTR_TO_CTX,
1099 };
1100
BPF_CALL_1(bpf_get_attach_cookie_kprobe_multi,struct pt_regs *,regs)1101 BPF_CALL_1(bpf_get_attach_cookie_kprobe_multi, struct pt_regs *, regs)
1102 {
1103 return bpf_kprobe_multi_cookie(current->bpf_ctx);
1104 }
1105
1106 static const struct bpf_func_proto bpf_get_attach_cookie_proto_kmulti = {
1107 .func = bpf_get_attach_cookie_kprobe_multi,
1108 .gpl_only = false,
1109 .ret_type = RET_INTEGER,
1110 .arg1_type = ARG_PTR_TO_CTX,
1111 };
1112
BPF_CALL_1(bpf_get_func_ip_uprobe_multi,struct pt_regs *,regs)1113 BPF_CALL_1(bpf_get_func_ip_uprobe_multi, struct pt_regs *, regs)
1114 {
1115 return bpf_uprobe_multi_entry_ip(current->bpf_ctx);
1116 }
1117
1118 static const struct bpf_func_proto bpf_get_func_ip_proto_uprobe_multi = {
1119 .func = bpf_get_func_ip_uprobe_multi,
1120 .gpl_only = false,
1121 .ret_type = RET_INTEGER,
1122 .arg1_type = ARG_PTR_TO_CTX,
1123 };
1124
BPF_CALL_1(bpf_get_attach_cookie_uprobe_multi,struct pt_regs *,regs)1125 BPF_CALL_1(bpf_get_attach_cookie_uprobe_multi, struct pt_regs *, regs)
1126 {
1127 return bpf_uprobe_multi_cookie(current->bpf_ctx);
1128 }
1129
1130 static const struct bpf_func_proto bpf_get_attach_cookie_proto_umulti = {
1131 .func = bpf_get_attach_cookie_uprobe_multi,
1132 .gpl_only = false,
1133 .ret_type = RET_INTEGER,
1134 .arg1_type = ARG_PTR_TO_CTX,
1135 };
1136
BPF_CALL_1(bpf_get_attach_cookie_trace,void *,ctx)1137 BPF_CALL_1(bpf_get_attach_cookie_trace, void *, ctx)
1138 {
1139 struct bpf_trace_run_ctx *run_ctx;
1140
1141 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx);
1142 return run_ctx->bpf_cookie;
1143 }
1144
1145 static const struct bpf_func_proto bpf_get_attach_cookie_proto_trace = {
1146 .func = bpf_get_attach_cookie_trace,
1147 .gpl_only = false,
1148 .ret_type = RET_INTEGER,
1149 .arg1_type = ARG_PTR_TO_CTX,
1150 };
1151
BPF_CALL_1(bpf_get_attach_cookie_pe,struct bpf_perf_event_data_kern *,ctx)1152 BPF_CALL_1(bpf_get_attach_cookie_pe, struct bpf_perf_event_data_kern *, ctx)
1153 {
1154 return ctx->event->bpf_cookie;
1155 }
1156
1157 static const struct bpf_func_proto bpf_get_attach_cookie_proto_pe = {
1158 .func = bpf_get_attach_cookie_pe,
1159 .gpl_only = false,
1160 .ret_type = RET_INTEGER,
1161 .arg1_type = ARG_PTR_TO_CTX,
1162 };
1163
BPF_CALL_1(bpf_get_attach_cookie_tracing,void *,ctx)1164 BPF_CALL_1(bpf_get_attach_cookie_tracing, void *, ctx)
1165 {
1166 struct bpf_trace_run_ctx *run_ctx;
1167
1168 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx);
1169 return run_ctx->bpf_cookie;
1170 }
1171
1172 static const struct bpf_func_proto bpf_get_attach_cookie_proto_tracing = {
1173 .func = bpf_get_attach_cookie_tracing,
1174 .gpl_only = false,
1175 .ret_type = RET_INTEGER,
1176 .arg1_type = ARG_PTR_TO_CTX,
1177 };
1178
BPF_CALL_3(bpf_get_branch_snapshot,void *,buf,u32,size,u64,flags)1179 BPF_CALL_3(bpf_get_branch_snapshot, void *, buf, u32, size, u64, flags)
1180 {
1181 static const u32 br_entry_size = sizeof(struct perf_branch_entry);
1182 u32 entry_cnt = size / br_entry_size;
1183
1184 entry_cnt = static_call(perf_snapshot_branch_stack)(buf, entry_cnt);
1185
1186 if (unlikely(flags))
1187 return -EINVAL;
1188
1189 if (!entry_cnt)
1190 return -ENOENT;
1191
1192 return entry_cnt * br_entry_size;
1193 }
1194
1195 static const struct bpf_func_proto bpf_get_branch_snapshot_proto = {
1196 .func = bpf_get_branch_snapshot,
1197 .gpl_only = true,
1198 .ret_type = RET_INTEGER,
1199 .arg1_type = ARG_PTR_TO_UNINIT_MEM,
1200 .arg2_type = ARG_CONST_SIZE_OR_ZERO,
1201 };
1202
BPF_CALL_3(get_func_arg,void *,ctx,u32,n,u64 *,value)1203 BPF_CALL_3(get_func_arg, void *, ctx, u32, n, u64 *, value)
1204 {
1205 /* This helper call is inlined by verifier. */
1206 u64 nr_args = ((u64 *)ctx)[-1];
1207
1208 if ((u64) n >= nr_args)
1209 return -EINVAL;
1210 *value = ((u64 *)ctx)[n];
1211 return 0;
1212 }
1213
1214 static const struct bpf_func_proto bpf_get_func_arg_proto = {
1215 .func = get_func_arg,
1216 .ret_type = RET_INTEGER,
1217 .arg1_type = ARG_PTR_TO_CTX,
1218 .arg2_type = ARG_ANYTHING,
1219 .arg3_type = ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED,
1220 .arg3_size = sizeof(u64),
1221 };
1222
BPF_CALL_2(get_func_ret,void *,ctx,u64 *,value)1223 BPF_CALL_2(get_func_ret, void *, ctx, u64 *, value)
1224 {
1225 /* This helper call is inlined by verifier. */
1226 u64 nr_args = ((u64 *)ctx)[-1];
1227
1228 *value = ((u64 *)ctx)[nr_args];
1229 return 0;
1230 }
1231
1232 static const struct bpf_func_proto bpf_get_func_ret_proto = {
1233 .func = get_func_ret,
1234 .ret_type = RET_INTEGER,
1235 .arg1_type = ARG_PTR_TO_CTX,
1236 .arg2_type = ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED,
1237 .arg2_size = sizeof(u64),
1238 };
1239
BPF_CALL_1(get_func_arg_cnt,void *,ctx)1240 BPF_CALL_1(get_func_arg_cnt, void *, ctx)
1241 {
1242 /* This helper call is inlined by verifier. */
1243 return ((u64 *)ctx)[-1];
1244 }
1245
1246 static const struct bpf_func_proto bpf_get_func_arg_cnt_proto = {
1247 .func = get_func_arg_cnt,
1248 .ret_type = RET_INTEGER,
1249 .arg1_type = ARG_PTR_TO_CTX,
1250 };
1251
1252 #ifdef CONFIG_KEYS
1253 __bpf_kfunc_start_defs();
1254
1255 /**
1256 * bpf_lookup_user_key - lookup a key by its serial
1257 * @serial: key handle serial number
1258 * @flags: lookup-specific flags
1259 *
1260 * Search a key with a given *serial* and the provided *flags*.
1261 * If found, increment the reference count of the key by one, and
1262 * return it in the bpf_key structure.
1263 *
1264 * The bpf_key structure must be passed to bpf_key_put() when done
1265 * with it, so that the key reference count is decremented and the
1266 * bpf_key structure is freed.
1267 *
1268 * Permission checks are deferred to the time the key is used by
1269 * one of the available key-specific kfuncs.
1270 *
1271 * Set *flags* with KEY_LOOKUP_CREATE, to attempt creating a requested
1272 * special keyring (e.g. session keyring), if it doesn't yet exist.
1273 * Set *flags* with KEY_LOOKUP_PARTIAL, to lookup a key without waiting
1274 * for the key construction, and to retrieve uninstantiated keys (keys
1275 * without data attached to them).
1276 *
1277 * Return: a bpf_key pointer with a valid key pointer if the key is found, a
1278 * NULL pointer otherwise.
1279 */
bpf_lookup_user_key(u32 serial,u64 flags)1280 __bpf_kfunc struct bpf_key *bpf_lookup_user_key(u32 serial, u64 flags)
1281 {
1282 key_ref_t key_ref;
1283 struct bpf_key *bkey;
1284
1285 if (flags & ~KEY_LOOKUP_ALL)
1286 return NULL;
1287
1288 /*
1289 * Permission check is deferred until the key is used, as the
1290 * intent of the caller is unknown here.
1291 */
1292 key_ref = lookup_user_key(serial, flags, KEY_DEFER_PERM_CHECK);
1293 if (IS_ERR(key_ref))
1294 return NULL;
1295
1296 bkey = kmalloc(sizeof(*bkey), GFP_KERNEL);
1297 if (!bkey) {
1298 key_put(key_ref_to_ptr(key_ref));
1299 return NULL;
1300 }
1301
1302 bkey->key = key_ref_to_ptr(key_ref);
1303 bkey->has_ref = true;
1304
1305 return bkey;
1306 }
1307
1308 /**
1309 * bpf_lookup_system_key - lookup a key by a system-defined ID
1310 * @id: key ID
1311 *
1312 * Obtain a bpf_key structure with a key pointer set to the passed key ID.
1313 * The key pointer is marked as invalid, to prevent bpf_key_put() from
1314 * attempting to decrement the key reference count on that pointer. The key
1315 * pointer set in such way is currently understood only by
1316 * verify_pkcs7_signature().
1317 *
1318 * Set *id* to one of the values defined in include/linux/verification.h:
1319 * 0 for the primary keyring (immutable keyring of system keys);
1320 * VERIFY_USE_SECONDARY_KEYRING for both the primary and secondary keyring
1321 * (where keys can be added only if they are vouched for by existing keys
1322 * in those keyrings); VERIFY_USE_PLATFORM_KEYRING for the platform
1323 * keyring (primarily used by the integrity subsystem to verify a kexec'ed
1324 * kerned image and, possibly, the initramfs signature).
1325 *
1326 * Return: a bpf_key pointer with an invalid key pointer set from the
1327 * pre-determined ID on success, a NULL pointer otherwise
1328 */
bpf_lookup_system_key(u64 id)1329 __bpf_kfunc struct bpf_key *bpf_lookup_system_key(u64 id)
1330 {
1331 struct bpf_key *bkey;
1332
1333 if (system_keyring_id_check(id) < 0)
1334 return NULL;
1335
1336 bkey = kmalloc(sizeof(*bkey), GFP_ATOMIC);
1337 if (!bkey)
1338 return NULL;
1339
1340 bkey->key = (struct key *)(unsigned long)id;
1341 bkey->has_ref = false;
1342
1343 return bkey;
1344 }
1345
1346 /**
1347 * bpf_key_put - decrement key reference count if key is valid and free bpf_key
1348 * @bkey: bpf_key structure
1349 *
1350 * Decrement the reference count of the key inside *bkey*, if the pointer
1351 * is valid, and free *bkey*.
1352 */
bpf_key_put(struct bpf_key * bkey)1353 __bpf_kfunc void bpf_key_put(struct bpf_key *bkey)
1354 {
1355 if (bkey->has_ref)
1356 key_put(bkey->key);
1357
1358 kfree(bkey);
1359 }
1360
1361 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION
1362 /**
1363 * bpf_verify_pkcs7_signature - verify a PKCS#7 signature
1364 * @data_p: data to verify
1365 * @sig_p: signature of the data
1366 * @trusted_keyring: keyring with keys trusted for signature verification
1367 *
1368 * Verify the PKCS#7 signature *sig_ptr* against the supplied *data_ptr*
1369 * with keys in a keyring referenced by *trusted_keyring*.
1370 *
1371 * Return: 0 on success, a negative value on error.
1372 */
bpf_verify_pkcs7_signature(struct bpf_dynptr * data_p,struct bpf_dynptr * sig_p,struct bpf_key * trusted_keyring)1373 __bpf_kfunc int bpf_verify_pkcs7_signature(struct bpf_dynptr *data_p,
1374 struct bpf_dynptr *sig_p,
1375 struct bpf_key *trusted_keyring)
1376 {
1377 struct bpf_dynptr_kern *data_ptr = (struct bpf_dynptr_kern *)data_p;
1378 struct bpf_dynptr_kern *sig_ptr = (struct bpf_dynptr_kern *)sig_p;
1379 const void *data, *sig;
1380 u32 data_len, sig_len;
1381 int ret;
1382
1383 if (trusted_keyring->has_ref) {
1384 /*
1385 * Do the permission check deferred in bpf_lookup_user_key().
1386 * See bpf_lookup_user_key() for more details.
1387 *
1388 * A call to key_task_permission() here would be redundant, as
1389 * it is already done by keyring_search() called by
1390 * find_asymmetric_key().
1391 */
1392 ret = key_validate(trusted_keyring->key);
1393 if (ret < 0)
1394 return ret;
1395 }
1396
1397 data_len = __bpf_dynptr_size(data_ptr);
1398 data = __bpf_dynptr_data(data_ptr, data_len);
1399 sig_len = __bpf_dynptr_size(sig_ptr);
1400 sig = __bpf_dynptr_data(sig_ptr, sig_len);
1401
1402 return verify_pkcs7_signature(data, data_len, sig, sig_len,
1403 trusted_keyring->key,
1404 VERIFYING_UNSPECIFIED_SIGNATURE, NULL,
1405 NULL);
1406 }
1407 #endif /* CONFIG_SYSTEM_DATA_VERIFICATION */
1408
1409 __bpf_kfunc_end_defs();
1410
1411 BTF_KFUNCS_START(key_sig_kfunc_set)
1412 BTF_ID_FLAGS(func, bpf_lookup_user_key, KF_ACQUIRE | KF_RET_NULL | KF_SLEEPABLE)
1413 BTF_ID_FLAGS(func, bpf_lookup_system_key, KF_ACQUIRE | KF_RET_NULL)
1414 BTF_ID_FLAGS(func, bpf_key_put, KF_RELEASE)
1415 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION
1416 BTF_ID_FLAGS(func, bpf_verify_pkcs7_signature, KF_SLEEPABLE)
1417 #endif
1418 BTF_KFUNCS_END(key_sig_kfunc_set)
1419
1420 static const struct btf_kfunc_id_set bpf_key_sig_kfunc_set = {
1421 .owner = THIS_MODULE,
1422 .set = &key_sig_kfunc_set,
1423 };
1424
bpf_key_sig_kfuncs_init(void)1425 static int __init bpf_key_sig_kfuncs_init(void)
1426 {
1427 return register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING,
1428 &bpf_key_sig_kfunc_set);
1429 }
1430
1431 late_initcall(bpf_key_sig_kfuncs_init);
1432 #endif /* CONFIG_KEYS */
1433
1434 static const struct bpf_func_proto *
bpf_tracing_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1435 bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1436 {
1437 const struct bpf_func_proto *func_proto;
1438
1439 switch (func_id) {
1440 case BPF_FUNC_map_lookup_elem:
1441 return &bpf_map_lookup_elem_proto;
1442 case BPF_FUNC_map_update_elem:
1443 return &bpf_map_update_elem_proto;
1444 case BPF_FUNC_map_delete_elem:
1445 return &bpf_map_delete_elem_proto;
1446 case BPF_FUNC_map_push_elem:
1447 return &bpf_map_push_elem_proto;
1448 case BPF_FUNC_map_pop_elem:
1449 return &bpf_map_pop_elem_proto;
1450 case BPF_FUNC_map_peek_elem:
1451 return &bpf_map_peek_elem_proto;
1452 case BPF_FUNC_map_lookup_percpu_elem:
1453 return &bpf_map_lookup_percpu_elem_proto;
1454 case BPF_FUNC_ktime_get_ns:
1455 return &bpf_ktime_get_ns_proto;
1456 case BPF_FUNC_ktime_get_boot_ns:
1457 return &bpf_ktime_get_boot_ns_proto;
1458 case BPF_FUNC_tail_call:
1459 return &bpf_tail_call_proto;
1460 case BPF_FUNC_get_current_task:
1461 return &bpf_get_current_task_proto;
1462 case BPF_FUNC_get_current_task_btf:
1463 return &bpf_get_current_task_btf_proto;
1464 case BPF_FUNC_task_pt_regs:
1465 return &bpf_task_pt_regs_proto;
1466 case BPF_FUNC_get_current_uid_gid:
1467 return &bpf_get_current_uid_gid_proto;
1468 case BPF_FUNC_get_current_comm:
1469 return &bpf_get_current_comm_proto;
1470 case BPF_FUNC_trace_printk:
1471 return bpf_get_trace_printk_proto();
1472 case BPF_FUNC_get_smp_processor_id:
1473 return &bpf_get_smp_processor_id_proto;
1474 case BPF_FUNC_get_numa_node_id:
1475 return &bpf_get_numa_node_id_proto;
1476 case BPF_FUNC_perf_event_read:
1477 return &bpf_perf_event_read_proto;
1478 case BPF_FUNC_get_prandom_u32:
1479 return &bpf_get_prandom_u32_proto;
1480 case BPF_FUNC_probe_read_user:
1481 return &bpf_probe_read_user_proto;
1482 case BPF_FUNC_probe_read_kernel:
1483 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
1484 NULL : &bpf_probe_read_kernel_proto;
1485 case BPF_FUNC_probe_read_user_str:
1486 return &bpf_probe_read_user_str_proto;
1487 case BPF_FUNC_probe_read_kernel_str:
1488 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
1489 NULL : &bpf_probe_read_kernel_str_proto;
1490 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
1491 case BPF_FUNC_probe_read:
1492 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
1493 NULL : &bpf_probe_read_compat_proto;
1494 case BPF_FUNC_probe_read_str:
1495 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
1496 NULL : &bpf_probe_read_compat_str_proto;
1497 #endif
1498 #ifdef CONFIG_CGROUPS
1499 case BPF_FUNC_cgrp_storage_get:
1500 return &bpf_cgrp_storage_get_proto;
1501 case BPF_FUNC_cgrp_storage_delete:
1502 return &bpf_cgrp_storage_delete_proto;
1503 case BPF_FUNC_current_task_under_cgroup:
1504 return &bpf_current_task_under_cgroup_proto;
1505 #endif
1506 case BPF_FUNC_send_signal:
1507 return &bpf_send_signal_proto;
1508 case BPF_FUNC_send_signal_thread:
1509 return &bpf_send_signal_thread_proto;
1510 case BPF_FUNC_perf_event_read_value:
1511 return &bpf_perf_event_read_value_proto;
1512 case BPF_FUNC_ringbuf_output:
1513 return &bpf_ringbuf_output_proto;
1514 case BPF_FUNC_ringbuf_reserve:
1515 return &bpf_ringbuf_reserve_proto;
1516 case BPF_FUNC_ringbuf_submit:
1517 return &bpf_ringbuf_submit_proto;
1518 case BPF_FUNC_ringbuf_discard:
1519 return &bpf_ringbuf_discard_proto;
1520 case BPF_FUNC_ringbuf_query:
1521 return &bpf_ringbuf_query_proto;
1522 case BPF_FUNC_jiffies64:
1523 return &bpf_jiffies64_proto;
1524 case BPF_FUNC_get_task_stack:
1525 return prog->sleepable ? &bpf_get_task_stack_sleepable_proto
1526 : &bpf_get_task_stack_proto;
1527 case BPF_FUNC_copy_from_user:
1528 return &bpf_copy_from_user_proto;
1529 case BPF_FUNC_copy_from_user_task:
1530 return &bpf_copy_from_user_task_proto;
1531 case BPF_FUNC_snprintf_btf:
1532 return &bpf_snprintf_btf_proto;
1533 case BPF_FUNC_per_cpu_ptr:
1534 return &bpf_per_cpu_ptr_proto;
1535 case BPF_FUNC_this_cpu_ptr:
1536 return &bpf_this_cpu_ptr_proto;
1537 case BPF_FUNC_task_storage_get:
1538 if (bpf_prog_check_recur(prog))
1539 return &bpf_task_storage_get_recur_proto;
1540 return &bpf_task_storage_get_proto;
1541 case BPF_FUNC_task_storage_delete:
1542 if (bpf_prog_check_recur(prog))
1543 return &bpf_task_storage_delete_recur_proto;
1544 return &bpf_task_storage_delete_proto;
1545 case BPF_FUNC_for_each_map_elem:
1546 return &bpf_for_each_map_elem_proto;
1547 case BPF_FUNC_snprintf:
1548 return &bpf_snprintf_proto;
1549 case BPF_FUNC_get_func_ip:
1550 return &bpf_get_func_ip_proto_tracing;
1551 case BPF_FUNC_get_branch_snapshot:
1552 return &bpf_get_branch_snapshot_proto;
1553 case BPF_FUNC_find_vma:
1554 return &bpf_find_vma_proto;
1555 case BPF_FUNC_trace_vprintk:
1556 return bpf_get_trace_vprintk_proto();
1557 default:
1558 break;
1559 }
1560
1561 func_proto = bpf_base_func_proto(func_id, prog);
1562 if (func_proto)
1563 return func_proto;
1564
1565 if (!bpf_token_capable(prog->aux->token, CAP_SYS_ADMIN))
1566 return NULL;
1567
1568 switch (func_id) {
1569 case BPF_FUNC_probe_write_user:
1570 return security_locked_down(LOCKDOWN_BPF_WRITE_USER) < 0 ?
1571 NULL : &bpf_probe_write_user_proto;
1572 default:
1573 return NULL;
1574 }
1575 }
1576
is_kprobe_multi(const struct bpf_prog * prog)1577 static bool is_kprobe_multi(const struct bpf_prog *prog)
1578 {
1579 return prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI ||
1580 prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION;
1581 }
1582
is_kprobe_session(const struct bpf_prog * prog)1583 static inline bool is_kprobe_session(const struct bpf_prog *prog)
1584 {
1585 return prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION;
1586 }
1587
is_uprobe_multi(const struct bpf_prog * prog)1588 static inline bool is_uprobe_multi(const struct bpf_prog *prog)
1589 {
1590 return prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI ||
1591 prog->expected_attach_type == BPF_TRACE_UPROBE_SESSION;
1592 }
1593
is_uprobe_session(const struct bpf_prog * prog)1594 static inline bool is_uprobe_session(const struct bpf_prog *prog)
1595 {
1596 return prog->expected_attach_type == BPF_TRACE_UPROBE_SESSION;
1597 }
1598
1599 static const struct bpf_func_proto *
kprobe_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1600 kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1601 {
1602 switch (func_id) {
1603 case BPF_FUNC_perf_event_output:
1604 return &bpf_perf_event_output_proto;
1605 case BPF_FUNC_get_stackid:
1606 return &bpf_get_stackid_proto;
1607 case BPF_FUNC_get_stack:
1608 return prog->sleepable ? &bpf_get_stack_sleepable_proto : &bpf_get_stack_proto;
1609 #ifdef CONFIG_BPF_KPROBE_OVERRIDE
1610 case BPF_FUNC_override_return:
1611 return &bpf_override_return_proto;
1612 #endif
1613 case BPF_FUNC_get_func_ip:
1614 if (is_kprobe_multi(prog))
1615 return &bpf_get_func_ip_proto_kprobe_multi;
1616 if (is_uprobe_multi(prog))
1617 return &bpf_get_func_ip_proto_uprobe_multi;
1618 return &bpf_get_func_ip_proto_kprobe;
1619 case BPF_FUNC_get_attach_cookie:
1620 if (is_kprobe_multi(prog))
1621 return &bpf_get_attach_cookie_proto_kmulti;
1622 if (is_uprobe_multi(prog))
1623 return &bpf_get_attach_cookie_proto_umulti;
1624 return &bpf_get_attach_cookie_proto_trace;
1625 default:
1626 return bpf_tracing_func_proto(func_id, prog);
1627 }
1628 }
1629
1630 /* 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)1631 static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
1632 const struct bpf_prog *prog,
1633 struct bpf_insn_access_aux *info)
1634 {
1635 if (off < 0 || off >= sizeof(struct pt_regs))
1636 return false;
1637 if (type != BPF_READ)
1638 return false;
1639 if (off % size != 0)
1640 return false;
1641 /*
1642 * Assertion for 32 bit to make sure last 8 byte access
1643 * (BPF_DW) to the last 4 byte member is disallowed.
1644 */
1645 if (off + size > sizeof(struct pt_regs))
1646 return false;
1647
1648 return true;
1649 }
1650
1651 const struct bpf_verifier_ops kprobe_verifier_ops = {
1652 .get_func_proto = kprobe_prog_func_proto,
1653 .is_valid_access = kprobe_prog_is_valid_access,
1654 };
1655
1656 const struct bpf_prog_ops kprobe_prog_ops = {
1657 };
1658
BPF_CALL_5(bpf_perf_event_output_tp,void *,tp_buff,struct bpf_map *,map,u64,flags,void *,data,u64,size)1659 BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map,
1660 u64, flags, void *, data, u64, size)
1661 {
1662 struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1663
1664 /*
1665 * r1 points to perf tracepoint buffer where first 8 bytes are hidden
1666 * from bpf program and contain a pointer to 'struct pt_regs'. Fetch it
1667 * from there and call the same bpf_perf_event_output() helper inline.
1668 */
1669 return ____bpf_perf_event_output(regs, map, flags, data, size);
1670 }
1671
1672 static const struct bpf_func_proto bpf_perf_event_output_proto_tp = {
1673 .func = bpf_perf_event_output_tp,
1674 .gpl_only = true,
1675 .ret_type = RET_INTEGER,
1676 .arg1_type = ARG_PTR_TO_CTX,
1677 .arg2_type = ARG_CONST_MAP_PTR,
1678 .arg3_type = ARG_ANYTHING,
1679 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY,
1680 .arg5_type = ARG_CONST_SIZE_OR_ZERO,
1681 };
1682
BPF_CALL_3(bpf_get_stackid_tp,void *,tp_buff,struct bpf_map *,map,u64,flags)1683 BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map,
1684 u64, flags)
1685 {
1686 struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1687
1688 /*
1689 * Same comment as in bpf_perf_event_output_tp(), only that this time
1690 * the other helper's function body cannot be inlined due to being
1691 * external, thus we need to call raw helper function.
1692 */
1693 return bpf_get_stackid((unsigned long) regs, (unsigned long) map,
1694 flags, 0, 0);
1695 }
1696
1697 static const struct bpf_func_proto bpf_get_stackid_proto_tp = {
1698 .func = bpf_get_stackid_tp,
1699 .gpl_only = true,
1700 .ret_type = RET_INTEGER,
1701 .arg1_type = ARG_PTR_TO_CTX,
1702 .arg2_type = ARG_CONST_MAP_PTR,
1703 .arg3_type = ARG_ANYTHING,
1704 };
1705
BPF_CALL_4(bpf_get_stack_tp,void *,tp_buff,void *,buf,u32,size,u64,flags)1706 BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size,
1707 u64, flags)
1708 {
1709 struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1710
1711 return bpf_get_stack((unsigned long) regs, (unsigned long) buf,
1712 (unsigned long) size, flags, 0);
1713 }
1714
1715 static const struct bpf_func_proto bpf_get_stack_proto_tp = {
1716 .func = bpf_get_stack_tp,
1717 .gpl_only = true,
1718 .ret_type = RET_INTEGER,
1719 .arg1_type = ARG_PTR_TO_CTX,
1720 .arg2_type = ARG_PTR_TO_UNINIT_MEM,
1721 .arg3_type = ARG_CONST_SIZE_OR_ZERO,
1722 .arg4_type = ARG_ANYTHING,
1723 };
1724
1725 static const struct bpf_func_proto *
tp_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1726 tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1727 {
1728 switch (func_id) {
1729 case BPF_FUNC_perf_event_output:
1730 return &bpf_perf_event_output_proto_tp;
1731 case BPF_FUNC_get_stackid:
1732 return &bpf_get_stackid_proto_tp;
1733 case BPF_FUNC_get_stack:
1734 return &bpf_get_stack_proto_tp;
1735 case BPF_FUNC_get_attach_cookie:
1736 return &bpf_get_attach_cookie_proto_trace;
1737 default:
1738 return bpf_tracing_func_proto(func_id, prog);
1739 }
1740 }
1741
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)1742 static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type,
1743 const struct bpf_prog *prog,
1744 struct bpf_insn_access_aux *info)
1745 {
1746 if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE)
1747 return false;
1748 if (type != BPF_READ)
1749 return false;
1750 if (off % size != 0)
1751 return false;
1752
1753 BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(__u64));
1754 return true;
1755 }
1756
1757 const struct bpf_verifier_ops tracepoint_verifier_ops = {
1758 .get_func_proto = tp_prog_func_proto,
1759 .is_valid_access = tp_prog_is_valid_access,
1760 };
1761
1762 const struct bpf_prog_ops tracepoint_prog_ops = {
1763 };
1764
BPF_CALL_3(bpf_perf_prog_read_value,struct bpf_perf_event_data_kern *,ctx,struct bpf_perf_event_value *,buf,u32,size)1765 BPF_CALL_3(bpf_perf_prog_read_value, struct bpf_perf_event_data_kern *, ctx,
1766 struct bpf_perf_event_value *, buf, u32, size)
1767 {
1768 int err = -EINVAL;
1769
1770 if (unlikely(size != sizeof(struct bpf_perf_event_value)))
1771 goto clear;
1772 err = perf_event_read_local(ctx->event, &buf->counter, &buf->enabled,
1773 &buf->running);
1774 if (unlikely(err))
1775 goto clear;
1776 return 0;
1777 clear:
1778 memset(buf, 0, size);
1779 return err;
1780 }
1781
1782 static const struct bpf_func_proto bpf_perf_prog_read_value_proto = {
1783 .func = bpf_perf_prog_read_value,
1784 .gpl_only = true,
1785 .ret_type = RET_INTEGER,
1786 .arg1_type = ARG_PTR_TO_CTX,
1787 .arg2_type = ARG_PTR_TO_UNINIT_MEM,
1788 .arg3_type = ARG_CONST_SIZE,
1789 };
1790
BPF_CALL_4(bpf_read_branch_records,struct bpf_perf_event_data_kern *,ctx,void *,buf,u32,size,u64,flags)1791 BPF_CALL_4(bpf_read_branch_records, struct bpf_perf_event_data_kern *, ctx,
1792 void *, buf, u32, size, u64, flags)
1793 {
1794 static const u32 br_entry_size = sizeof(struct perf_branch_entry);
1795 struct perf_branch_stack *br_stack = ctx->data->br_stack;
1796 u32 to_copy;
1797
1798 if (unlikely(flags & ~BPF_F_GET_BRANCH_RECORDS_SIZE))
1799 return -EINVAL;
1800
1801 if (unlikely(!(ctx->data->sample_flags & PERF_SAMPLE_BRANCH_STACK)))
1802 return -ENOENT;
1803
1804 if (unlikely(!br_stack))
1805 return -ENOENT;
1806
1807 if (flags & BPF_F_GET_BRANCH_RECORDS_SIZE)
1808 return br_stack->nr * br_entry_size;
1809
1810 if (!buf || (size % br_entry_size != 0))
1811 return -EINVAL;
1812
1813 to_copy = min_t(u32, br_stack->nr * br_entry_size, size);
1814 memcpy(buf, br_stack->entries, to_copy);
1815
1816 return to_copy;
1817 }
1818
1819 static const struct bpf_func_proto bpf_read_branch_records_proto = {
1820 .func = bpf_read_branch_records,
1821 .gpl_only = true,
1822 .ret_type = RET_INTEGER,
1823 .arg1_type = ARG_PTR_TO_CTX,
1824 .arg2_type = ARG_PTR_TO_MEM_OR_NULL,
1825 .arg3_type = ARG_CONST_SIZE_OR_ZERO,
1826 .arg4_type = ARG_ANYTHING,
1827 };
1828
1829 static const struct bpf_func_proto *
pe_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1830 pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1831 {
1832 switch (func_id) {
1833 case BPF_FUNC_perf_event_output:
1834 return &bpf_perf_event_output_proto_tp;
1835 case BPF_FUNC_get_stackid:
1836 return &bpf_get_stackid_proto_pe;
1837 case BPF_FUNC_get_stack:
1838 return &bpf_get_stack_proto_pe;
1839 case BPF_FUNC_perf_prog_read_value:
1840 return &bpf_perf_prog_read_value_proto;
1841 case BPF_FUNC_read_branch_records:
1842 return &bpf_read_branch_records_proto;
1843 case BPF_FUNC_get_attach_cookie:
1844 return &bpf_get_attach_cookie_proto_pe;
1845 default:
1846 return bpf_tracing_func_proto(func_id, prog);
1847 }
1848 }
1849
1850 /*
1851 * bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp
1852 * to avoid potential recursive reuse issue when/if tracepoints are added
1853 * inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack.
1854 *
1855 * Since raw tracepoints run despite bpf_prog_active, support concurrent usage
1856 * in normal, irq, and nmi context.
1857 */
1858 struct bpf_raw_tp_regs {
1859 struct pt_regs regs[3];
1860 };
1861 static DEFINE_PER_CPU(struct bpf_raw_tp_regs, bpf_raw_tp_regs);
1862 static DEFINE_PER_CPU(int, bpf_raw_tp_nest_level);
get_bpf_raw_tp_regs(void)1863 static struct pt_regs *get_bpf_raw_tp_regs(void)
1864 {
1865 struct bpf_raw_tp_regs *tp_regs = this_cpu_ptr(&bpf_raw_tp_regs);
1866 int nest_level = this_cpu_inc_return(bpf_raw_tp_nest_level);
1867
1868 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(tp_regs->regs))) {
1869 this_cpu_dec(bpf_raw_tp_nest_level);
1870 return ERR_PTR(-EBUSY);
1871 }
1872
1873 return &tp_regs->regs[nest_level - 1];
1874 }
1875
put_bpf_raw_tp_regs(void)1876 static void put_bpf_raw_tp_regs(void)
1877 {
1878 this_cpu_dec(bpf_raw_tp_nest_level);
1879 }
1880
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)1881 BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args,
1882 struct bpf_map *, map, u64, flags, void *, data, u64, size)
1883 {
1884 struct pt_regs *regs = get_bpf_raw_tp_regs();
1885 int ret;
1886
1887 if (IS_ERR(regs))
1888 return PTR_ERR(regs);
1889
1890 perf_fetch_caller_regs(regs);
1891 ret = ____bpf_perf_event_output(regs, map, flags, data, size);
1892
1893 put_bpf_raw_tp_regs();
1894 return ret;
1895 }
1896
1897 static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = {
1898 .func = bpf_perf_event_output_raw_tp,
1899 .gpl_only = true,
1900 .ret_type = RET_INTEGER,
1901 .arg1_type = ARG_PTR_TO_CTX,
1902 .arg2_type = ARG_CONST_MAP_PTR,
1903 .arg3_type = ARG_ANYTHING,
1904 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY,
1905 .arg5_type = ARG_CONST_SIZE_OR_ZERO,
1906 };
1907
1908 extern const struct bpf_func_proto bpf_skb_output_proto;
1909 extern const struct bpf_func_proto bpf_xdp_output_proto;
1910 extern const struct bpf_func_proto bpf_xdp_get_buff_len_trace_proto;
1911
BPF_CALL_3(bpf_get_stackid_raw_tp,struct bpf_raw_tracepoint_args *,args,struct bpf_map *,map,u64,flags)1912 BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args,
1913 struct bpf_map *, map, u64, flags)
1914 {
1915 struct pt_regs *regs = get_bpf_raw_tp_regs();
1916 int ret;
1917
1918 if (IS_ERR(regs))
1919 return PTR_ERR(regs);
1920
1921 perf_fetch_caller_regs(regs);
1922 /* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */
1923 ret = bpf_get_stackid((unsigned long) regs, (unsigned long) map,
1924 flags, 0, 0);
1925 put_bpf_raw_tp_regs();
1926 return ret;
1927 }
1928
1929 static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = {
1930 .func = bpf_get_stackid_raw_tp,
1931 .gpl_only = true,
1932 .ret_type = RET_INTEGER,
1933 .arg1_type = ARG_PTR_TO_CTX,
1934 .arg2_type = ARG_CONST_MAP_PTR,
1935 .arg3_type = ARG_ANYTHING,
1936 };
1937
BPF_CALL_4(bpf_get_stack_raw_tp,struct bpf_raw_tracepoint_args *,args,void *,buf,u32,size,u64,flags)1938 BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args,
1939 void *, buf, u32, size, u64, flags)
1940 {
1941 struct pt_regs *regs = get_bpf_raw_tp_regs();
1942 int ret;
1943
1944 if (IS_ERR(regs))
1945 return PTR_ERR(regs);
1946
1947 perf_fetch_caller_regs(regs);
1948 ret = bpf_get_stack((unsigned long) regs, (unsigned long) buf,
1949 (unsigned long) size, flags, 0);
1950 put_bpf_raw_tp_regs();
1951 return ret;
1952 }
1953
1954 static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = {
1955 .func = bpf_get_stack_raw_tp,
1956 .gpl_only = true,
1957 .ret_type = RET_INTEGER,
1958 .arg1_type = ARG_PTR_TO_CTX,
1959 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
1960 .arg3_type = ARG_CONST_SIZE_OR_ZERO,
1961 .arg4_type = ARG_ANYTHING,
1962 };
1963
1964 static const struct bpf_func_proto *
raw_tp_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1965 raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1966 {
1967 switch (func_id) {
1968 case BPF_FUNC_perf_event_output:
1969 return &bpf_perf_event_output_proto_raw_tp;
1970 case BPF_FUNC_get_stackid:
1971 return &bpf_get_stackid_proto_raw_tp;
1972 case BPF_FUNC_get_stack:
1973 return &bpf_get_stack_proto_raw_tp;
1974 case BPF_FUNC_get_attach_cookie:
1975 return &bpf_get_attach_cookie_proto_tracing;
1976 default:
1977 return bpf_tracing_func_proto(func_id, prog);
1978 }
1979 }
1980
1981 const struct bpf_func_proto *
tracing_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1982 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1983 {
1984 const struct bpf_func_proto *fn;
1985
1986 switch (func_id) {
1987 #ifdef CONFIG_NET
1988 case BPF_FUNC_skb_output:
1989 return &bpf_skb_output_proto;
1990 case BPF_FUNC_xdp_output:
1991 return &bpf_xdp_output_proto;
1992 case BPF_FUNC_skc_to_tcp6_sock:
1993 return &bpf_skc_to_tcp6_sock_proto;
1994 case BPF_FUNC_skc_to_tcp_sock:
1995 return &bpf_skc_to_tcp_sock_proto;
1996 case BPF_FUNC_skc_to_tcp_timewait_sock:
1997 return &bpf_skc_to_tcp_timewait_sock_proto;
1998 case BPF_FUNC_skc_to_tcp_request_sock:
1999 return &bpf_skc_to_tcp_request_sock_proto;
2000 case BPF_FUNC_skc_to_udp6_sock:
2001 return &bpf_skc_to_udp6_sock_proto;
2002 case BPF_FUNC_skc_to_unix_sock:
2003 return &bpf_skc_to_unix_sock_proto;
2004 case BPF_FUNC_skc_to_mptcp_sock:
2005 return &bpf_skc_to_mptcp_sock_proto;
2006 case BPF_FUNC_sk_storage_get:
2007 return &bpf_sk_storage_get_tracing_proto;
2008 case BPF_FUNC_sk_storage_delete:
2009 return &bpf_sk_storage_delete_tracing_proto;
2010 case BPF_FUNC_sock_from_file:
2011 return &bpf_sock_from_file_proto;
2012 case BPF_FUNC_get_socket_cookie:
2013 return &bpf_get_socket_ptr_cookie_proto;
2014 case BPF_FUNC_xdp_get_buff_len:
2015 return &bpf_xdp_get_buff_len_trace_proto;
2016 #endif
2017 case BPF_FUNC_seq_printf:
2018 return prog->expected_attach_type == BPF_TRACE_ITER ?
2019 &bpf_seq_printf_proto :
2020 NULL;
2021 case BPF_FUNC_seq_write:
2022 return prog->expected_attach_type == BPF_TRACE_ITER ?
2023 &bpf_seq_write_proto :
2024 NULL;
2025 case BPF_FUNC_seq_printf_btf:
2026 return prog->expected_attach_type == BPF_TRACE_ITER ?
2027 &bpf_seq_printf_btf_proto :
2028 NULL;
2029 case BPF_FUNC_d_path:
2030 return &bpf_d_path_proto;
2031 case BPF_FUNC_get_func_arg:
2032 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_proto : NULL;
2033 case BPF_FUNC_get_func_ret:
2034 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_ret_proto : NULL;
2035 case BPF_FUNC_get_func_arg_cnt:
2036 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_cnt_proto : NULL;
2037 case BPF_FUNC_get_attach_cookie:
2038 if (prog->type == BPF_PROG_TYPE_TRACING &&
2039 prog->expected_attach_type == BPF_TRACE_RAW_TP)
2040 return &bpf_get_attach_cookie_proto_tracing;
2041 return bpf_prog_has_trampoline(prog) ? &bpf_get_attach_cookie_proto_tracing : NULL;
2042 default:
2043 fn = raw_tp_prog_func_proto(func_id, prog);
2044 if (!fn && prog->expected_attach_type == BPF_TRACE_ITER)
2045 fn = bpf_iter_get_func_proto(func_id, prog);
2046 return fn;
2047 }
2048 }
2049
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)2050 static bool raw_tp_prog_is_valid_access(int off, int size,
2051 enum bpf_access_type type,
2052 const struct bpf_prog *prog,
2053 struct bpf_insn_access_aux *info)
2054 {
2055 return bpf_tracing_ctx_access(off, size, type);
2056 }
2057
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)2058 static bool tracing_prog_is_valid_access(int off, int size,
2059 enum bpf_access_type type,
2060 const struct bpf_prog *prog,
2061 struct bpf_insn_access_aux *info)
2062 {
2063 return bpf_tracing_btf_ctx_access(off, size, type, prog, info);
2064 }
2065
bpf_prog_test_run_tracing(struct bpf_prog * prog,const union bpf_attr * kattr,union bpf_attr __user * uattr)2066 int __weak bpf_prog_test_run_tracing(struct bpf_prog *prog,
2067 const union bpf_attr *kattr,
2068 union bpf_attr __user *uattr)
2069 {
2070 return -ENOTSUPP;
2071 }
2072
2073 const struct bpf_verifier_ops raw_tracepoint_verifier_ops = {
2074 .get_func_proto = raw_tp_prog_func_proto,
2075 .is_valid_access = raw_tp_prog_is_valid_access,
2076 };
2077
2078 const struct bpf_prog_ops raw_tracepoint_prog_ops = {
2079 #ifdef CONFIG_NET
2080 .test_run = bpf_prog_test_run_raw_tp,
2081 #endif
2082 };
2083
2084 const struct bpf_verifier_ops tracing_verifier_ops = {
2085 .get_func_proto = tracing_prog_func_proto,
2086 .is_valid_access = tracing_prog_is_valid_access,
2087 };
2088
2089 const struct bpf_prog_ops tracing_prog_ops = {
2090 .test_run = bpf_prog_test_run_tracing,
2091 };
2092
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)2093 static bool raw_tp_writable_prog_is_valid_access(int off, int size,
2094 enum bpf_access_type type,
2095 const struct bpf_prog *prog,
2096 struct bpf_insn_access_aux *info)
2097 {
2098 if (off == 0) {
2099 if (size != sizeof(u64) || type != BPF_READ)
2100 return false;
2101 info->reg_type = PTR_TO_TP_BUFFER;
2102 }
2103 return raw_tp_prog_is_valid_access(off, size, type, prog, info);
2104 }
2105
2106 const struct bpf_verifier_ops raw_tracepoint_writable_verifier_ops = {
2107 .get_func_proto = raw_tp_prog_func_proto,
2108 .is_valid_access = raw_tp_writable_prog_is_valid_access,
2109 };
2110
2111 const struct bpf_prog_ops raw_tracepoint_writable_prog_ops = {
2112 };
2113
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)2114 static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
2115 const struct bpf_prog *prog,
2116 struct bpf_insn_access_aux *info)
2117 {
2118 const int size_u64 = sizeof(u64);
2119
2120 if (off < 0 || off >= sizeof(struct bpf_perf_event_data))
2121 return false;
2122 if (type != BPF_READ)
2123 return false;
2124 if (off % size != 0) {
2125 if (sizeof(unsigned long) != 4)
2126 return false;
2127 if (size != 8)
2128 return false;
2129 if (off % size != 4)
2130 return false;
2131 }
2132
2133 switch (off) {
2134 case bpf_ctx_range(struct bpf_perf_event_data, sample_period):
2135 bpf_ctx_record_field_size(info, size_u64);
2136 if (!bpf_ctx_narrow_access_ok(off, size, size_u64))
2137 return false;
2138 break;
2139 case bpf_ctx_range(struct bpf_perf_event_data, addr):
2140 bpf_ctx_record_field_size(info, size_u64);
2141 if (!bpf_ctx_narrow_access_ok(off, size, size_u64))
2142 return false;
2143 break;
2144 default:
2145 if (size != sizeof(long))
2146 return false;
2147 }
2148
2149 return true;
2150 }
2151
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)2152 static u32 pe_prog_convert_ctx_access(enum bpf_access_type type,
2153 const struct bpf_insn *si,
2154 struct bpf_insn *insn_buf,
2155 struct bpf_prog *prog, u32 *target_size)
2156 {
2157 struct bpf_insn *insn = insn_buf;
2158
2159 switch (si->off) {
2160 case offsetof(struct bpf_perf_event_data, sample_period):
2161 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
2162 data), si->dst_reg, si->src_reg,
2163 offsetof(struct bpf_perf_event_data_kern, data));
2164 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg,
2165 bpf_target_off(struct perf_sample_data, period, 8,
2166 target_size));
2167 break;
2168 case offsetof(struct bpf_perf_event_data, addr):
2169 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
2170 data), si->dst_reg, si->src_reg,
2171 offsetof(struct bpf_perf_event_data_kern, data));
2172 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg,
2173 bpf_target_off(struct perf_sample_data, addr, 8,
2174 target_size));
2175 break;
2176 default:
2177 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
2178 regs), si->dst_reg, si->src_reg,
2179 offsetof(struct bpf_perf_event_data_kern, regs));
2180 *insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg,
2181 si->off);
2182 break;
2183 }
2184
2185 return insn - insn_buf;
2186 }
2187
2188 const struct bpf_verifier_ops perf_event_verifier_ops = {
2189 .get_func_proto = pe_prog_func_proto,
2190 .is_valid_access = pe_prog_is_valid_access,
2191 .convert_ctx_access = pe_prog_convert_ctx_access,
2192 };
2193
2194 const struct bpf_prog_ops perf_event_prog_ops = {
2195 };
2196
2197 static DEFINE_MUTEX(bpf_event_mutex);
2198
2199 #define BPF_TRACE_MAX_PROGS 64
2200
perf_event_attach_bpf_prog(struct perf_event * event,struct bpf_prog * prog,u64 bpf_cookie)2201 int perf_event_attach_bpf_prog(struct perf_event *event,
2202 struct bpf_prog *prog,
2203 u64 bpf_cookie)
2204 {
2205 struct bpf_prog_array *old_array;
2206 struct bpf_prog_array *new_array;
2207 int ret = -EEXIST;
2208
2209 /*
2210 * Kprobe override only works if they are on the function entry,
2211 * and only if they are on the opt-in list.
2212 */
2213 if (prog->kprobe_override &&
2214 (!trace_kprobe_on_func_entry(event->tp_event) ||
2215 !trace_kprobe_error_injectable(event->tp_event)))
2216 return -EINVAL;
2217
2218 mutex_lock(&bpf_event_mutex);
2219
2220 if (event->prog)
2221 goto unlock;
2222
2223 old_array = bpf_event_rcu_dereference(event->tp_event->prog_array);
2224 if (old_array &&
2225 bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) {
2226 ret = -E2BIG;
2227 goto unlock;
2228 }
2229
2230 ret = bpf_prog_array_copy(old_array, NULL, prog, bpf_cookie, &new_array);
2231 if (ret < 0)
2232 goto unlock;
2233
2234 /* set the new array to event->tp_event and set event->prog */
2235 event->prog = prog;
2236 event->bpf_cookie = bpf_cookie;
2237 rcu_assign_pointer(event->tp_event->prog_array, new_array);
2238 bpf_prog_array_free_sleepable(old_array);
2239
2240 unlock:
2241 mutex_unlock(&bpf_event_mutex);
2242 return ret;
2243 }
2244
perf_event_detach_bpf_prog(struct perf_event * event)2245 void perf_event_detach_bpf_prog(struct perf_event *event)
2246 {
2247 struct bpf_prog_array *old_array;
2248 struct bpf_prog_array *new_array;
2249 struct bpf_prog *prog = NULL;
2250 int ret;
2251
2252 mutex_lock(&bpf_event_mutex);
2253
2254 if (!event->prog)
2255 goto unlock;
2256
2257 old_array = bpf_event_rcu_dereference(event->tp_event->prog_array);
2258 if (!old_array)
2259 goto put;
2260
2261 ret = bpf_prog_array_copy(old_array, event->prog, NULL, 0, &new_array);
2262 if (ret < 0) {
2263 bpf_prog_array_delete_safe(old_array, event->prog);
2264 } else {
2265 rcu_assign_pointer(event->tp_event->prog_array, new_array);
2266 bpf_prog_array_free_sleepable(old_array);
2267 }
2268
2269 put:
2270 prog = event->prog;
2271 event->prog = NULL;
2272
2273 unlock:
2274 mutex_unlock(&bpf_event_mutex);
2275
2276 if (prog) {
2277 /*
2278 * It could be that the bpf_prog is not sleepable (and will be freed
2279 * via normal RCU), but is called from a point that supports sleepable
2280 * programs and uses tasks-trace-RCU.
2281 */
2282 synchronize_rcu_tasks_trace();
2283
2284 bpf_prog_put(prog);
2285 }
2286 }
2287
perf_event_query_prog_array(struct perf_event * event,void __user * info)2288 int perf_event_query_prog_array(struct perf_event *event, void __user *info)
2289 {
2290 struct perf_event_query_bpf __user *uquery = info;
2291 struct perf_event_query_bpf query = {};
2292 struct bpf_prog_array *progs;
2293 u32 *ids, prog_cnt, ids_len;
2294 int ret;
2295
2296 if (!perfmon_capable())
2297 return -EPERM;
2298 if (event->attr.type != PERF_TYPE_TRACEPOINT)
2299 return -EINVAL;
2300 if (copy_from_user(&query, uquery, sizeof(query)))
2301 return -EFAULT;
2302
2303 ids_len = query.ids_len;
2304 if (ids_len > BPF_TRACE_MAX_PROGS)
2305 return -E2BIG;
2306 ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN);
2307 if (!ids)
2308 return -ENOMEM;
2309 /*
2310 * The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which
2311 * is required when user only wants to check for uquery->prog_cnt.
2312 * There is no need to check for it since the case is handled
2313 * gracefully in bpf_prog_array_copy_info.
2314 */
2315
2316 mutex_lock(&bpf_event_mutex);
2317 progs = bpf_event_rcu_dereference(event->tp_event->prog_array);
2318 ret = bpf_prog_array_copy_info(progs, ids, ids_len, &prog_cnt);
2319 mutex_unlock(&bpf_event_mutex);
2320
2321 if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) ||
2322 copy_to_user(uquery->ids, ids, ids_len * sizeof(u32)))
2323 ret = -EFAULT;
2324
2325 kfree(ids);
2326 return ret;
2327 }
2328
2329 extern struct bpf_raw_event_map __start__bpf_raw_tp[];
2330 extern struct bpf_raw_event_map __stop__bpf_raw_tp[];
2331
bpf_get_raw_tracepoint(const char * name)2332 struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name)
2333 {
2334 struct bpf_raw_event_map *btp = __start__bpf_raw_tp;
2335
2336 for (; btp < __stop__bpf_raw_tp; btp++) {
2337 if (!strcmp(btp->tp->name, name))
2338 return btp;
2339 }
2340
2341 return bpf_get_raw_tracepoint_module(name);
2342 }
2343
bpf_put_raw_tracepoint(struct bpf_raw_event_map * btp)2344 void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp)
2345 {
2346 struct module *mod;
2347
2348 preempt_disable();
2349 mod = __module_address((unsigned long)btp);
2350 module_put(mod);
2351 preempt_enable();
2352 }
2353
2354 static __always_inline
__bpf_trace_run(struct bpf_raw_tp_link * link,u64 * args)2355 void __bpf_trace_run(struct bpf_raw_tp_link *link, u64 *args)
2356 {
2357 struct bpf_prog *prog = link->link.prog;
2358 struct bpf_run_ctx *old_run_ctx;
2359 struct bpf_trace_run_ctx run_ctx;
2360
2361 cant_sleep();
2362 if (unlikely(this_cpu_inc_return(*(prog->active)) != 1)) {
2363 bpf_prog_inc_misses_counter(prog);
2364 goto out;
2365 }
2366
2367 run_ctx.bpf_cookie = link->cookie;
2368 old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx);
2369
2370 rcu_read_lock();
2371 (void) bpf_prog_run(prog, args);
2372 rcu_read_unlock();
2373
2374 bpf_reset_run_ctx(old_run_ctx);
2375 out:
2376 this_cpu_dec(*(prog->active));
2377 }
2378
2379 #define UNPACK(...) __VA_ARGS__
2380 #define REPEAT_1(FN, DL, X, ...) FN(X)
2381 #define REPEAT_2(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__)
2382 #define REPEAT_3(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_2(FN, DL, __VA_ARGS__)
2383 #define REPEAT_4(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_3(FN, DL, __VA_ARGS__)
2384 #define REPEAT_5(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_4(FN, DL, __VA_ARGS__)
2385 #define REPEAT_6(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_5(FN, DL, __VA_ARGS__)
2386 #define REPEAT_7(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_6(FN, DL, __VA_ARGS__)
2387 #define REPEAT_8(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_7(FN, DL, __VA_ARGS__)
2388 #define REPEAT_9(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_8(FN, DL, __VA_ARGS__)
2389 #define REPEAT_10(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_9(FN, DL, __VA_ARGS__)
2390 #define REPEAT_11(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_10(FN, DL, __VA_ARGS__)
2391 #define REPEAT_12(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_11(FN, DL, __VA_ARGS__)
2392 #define REPEAT(X, FN, DL, ...) REPEAT_##X(FN, DL, __VA_ARGS__)
2393
2394 #define SARG(X) u64 arg##X
2395 #define COPY(X) args[X] = arg##X
2396
2397 #define __DL_COM (,)
2398 #define __DL_SEM (;)
2399
2400 #define __SEQ_0_11 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11
2401
2402 #define BPF_TRACE_DEFN_x(x) \
2403 void bpf_trace_run##x(struct bpf_raw_tp_link *link, \
2404 REPEAT(x, SARG, __DL_COM, __SEQ_0_11)) \
2405 { \
2406 u64 args[x]; \
2407 REPEAT(x, COPY, __DL_SEM, __SEQ_0_11); \
2408 __bpf_trace_run(link, args); \
2409 } \
2410 EXPORT_SYMBOL_GPL(bpf_trace_run##x)
2411 BPF_TRACE_DEFN_x(1);
2412 BPF_TRACE_DEFN_x(2);
2413 BPF_TRACE_DEFN_x(3);
2414 BPF_TRACE_DEFN_x(4);
2415 BPF_TRACE_DEFN_x(5);
2416 BPF_TRACE_DEFN_x(6);
2417 BPF_TRACE_DEFN_x(7);
2418 BPF_TRACE_DEFN_x(8);
2419 BPF_TRACE_DEFN_x(9);
2420 BPF_TRACE_DEFN_x(10);
2421 BPF_TRACE_DEFN_x(11);
2422 BPF_TRACE_DEFN_x(12);
2423
bpf_probe_register(struct bpf_raw_event_map * btp,struct bpf_raw_tp_link * link)2424 int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_raw_tp_link *link)
2425 {
2426 struct tracepoint *tp = btp->tp;
2427 struct bpf_prog *prog = link->link.prog;
2428
2429 /*
2430 * check that program doesn't access arguments beyond what's
2431 * available in this tracepoint
2432 */
2433 if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64))
2434 return -EINVAL;
2435
2436 if (prog->aux->max_tp_access > btp->writable_size)
2437 return -EINVAL;
2438
2439 return tracepoint_probe_register_may_exist(tp, (void *)btp->bpf_func, link);
2440 }
2441
bpf_probe_unregister(struct bpf_raw_event_map * btp,struct bpf_raw_tp_link * link)2442 int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_raw_tp_link *link)
2443 {
2444 return tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, link);
2445 }
2446
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)2447 int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id,
2448 u32 *fd_type, const char **buf,
2449 u64 *probe_offset, u64 *probe_addr,
2450 unsigned long *missed)
2451 {
2452 bool is_tracepoint, is_syscall_tp;
2453 struct bpf_prog *prog;
2454 int flags, err = 0;
2455
2456 prog = event->prog;
2457 if (!prog)
2458 return -ENOENT;
2459
2460 /* not supporting BPF_PROG_TYPE_PERF_EVENT yet */
2461 if (prog->type == BPF_PROG_TYPE_PERF_EVENT)
2462 return -EOPNOTSUPP;
2463
2464 *prog_id = prog->aux->id;
2465 flags = event->tp_event->flags;
2466 is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT;
2467 is_syscall_tp = is_syscall_trace_event(event->tp_event);
2468
2469 if (is_tracepoint || is_syscall_tp) {
2470 *buf = is_tracepoint ? event->tp_event->tp->name
2471 : event->tp_event->name;
2472 /* We allow NULL pointer for tracepoint */
2473 if (fd_type)
2474 *fd_type = BPF_FD_TYPE_TRACEPOINT;
2475 if (probe_offset)
2476 *probe_offset = 0x0;
2477 if (probe_addr)
2478 *probe_addr = 0x0;
2479 } else {
2480 /* kprobe/uprobe */
2481 err = -EOPNOTSUPP;
2482 #ifdef CONFIG_KPROBE_EVENTS
2483 if (flags & TRACE_EVENT_FL_KPROBE)
2484 err = bpf_get_kprobe_info(event, fd_type, buf,
2485 probe_offset, probe_addr, missed,
2486 event->attr.type == PERF_TYPE_TRACEPOINT);
2487 #endif
2488 #ifdef CONFIG_UPROBE_EVENTS
2489 if (flags & TRACE_EVENT_FL_UPROBE)
2490 err = bpf_get_uprobe_info(event, fd_type, buf,
2491 probe_offset, probe_addr,
2492 event->attr.type == PERF_TYPE_TRACEPOINT);
2493 #endif
2494 }
2495
2496 return err;
2497 }
2498
send_signal_irq_work_init(void)2499 static int __init send_signal_irq_work_init(void)
2500 {
2501 int cpu;
2502 struct send_signal_irq_work *work;
2503
2504 for_each_possible_cpu(cpu) {
2505 work = per_cpu_ptr(&send_signal_work, cpu);
2506 init_irq_work(&work->irq_work, do_bpf_send_signal);
2507 }
2508 return 0;
2509 }
2510
2511 subsys_initcall(send_signal_irq_work_init);
2512
2513 #ifdef CONFIG_MODULES
bpf_event_notify(struct notifier_block * nb,unsigned long op,void * module)2514 static int bpf_event_notify(struct notifier_block *nb, unsigned long op,
2515 void *module)
2516 {
2517 struct bpf_trace_module *btm, *tmp;
2518 struct module *mod = module;
2519 int ret = 0;
2520
2521 if (mod->num_bpf_raw_events == 0 ||
2522 (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING))
2523 goto out;
2524
2525 mutex_lock(&bpf_module_mutex);
2526
2527 switch (op) {
2528 case MODULE_STATE_COMING:
2529 btm = kzalloc(sizeof(*btm), GFP_KERNEL);
2530 if (btm) {
2531 btm->module = module;
2532 list_add(&btm->list, &bpf_trace_modules);
2533 } else {
2534 ret = -ENOMEM;
2535 }
2536 break;
2537 case MODULE_STATE_GOING:
2538 list_for_each_entry_safe(btm, tmp, &bpf_trace_modules, list) {
2539 if (btm->module == module) {
2540 list_del(&btm->list);
2541 kfree(btm);
2542 break;
2543 }
2544 }
2545 break;
2546 }
2547
2548 mutex_unlock(&bpf_module_mutex);
2549
2550 out:
2551 return notifier_from_errno(ret);
2552 }
2553
2554 static struct notifier_block bpf_module_nb = {
2555 .notifier_call = bpf_event_notify,
2556 };
2557
bpf_event_init(void)2558 static int __init bpf_event_init(void)
2559 {
2560 register_module_notifier(&bpf_module_nb);
2561 return 0;
2562 }
2563
2564 fs_initcall(bpf_event_init);
2565 #endif /* CONFIG_MODULES */
2566
2567 struct bpf_session_run_ctx {
2568 struct bpf_run_ctx run_ctx;
2569 bool is_return;
2570 void *data;
2571 };
2572
2573 #ifdef CONFIG_FPROBE
2574 struct bpf_kprobe_multi_link {
2575 struct bpf_link link;
2576 struct fprobe fp;
2577 unsigned long *addrs;
2578 u64 *cookies;
2579 u32 cnt;
2580 u32 mods_cnt;
2581 struct module **mods;
2582 u32 flags;
2583 };
2584
2585 struct bpf_kprobe_multi_run_ctx {
2586 struct bpf_session_run_ctx session_ctx;
2587 struct bpf_kprobe_multi_link *link;
2588 unsigned long entry_ip;
2589 };
2590
2591 struct user_syms {
2592 const char **syms;
2593 char *buf;
2594 };
2595
2596 #ifndef CONFIG_HAVE_FTRACE_REGS_HAVING_PT_REGS
2597 static DEFINE_PER_CPU(struct pt_regs, bpf_kprobe_multi_pt_regs);
2598 #define bpf_kprobe_multi_pt_regs_ptr() this_cpu_ptr(&bpf_kprobe_multi_pt_regs)
2599 #else
2600 #define bpf_kprobe_multi_pt_regs_ptr() (NULL)
2601 #endif
2602
ftrace_get_entry_ip(unsigned long fentry_ip)2603 static unsigned long ftrace_get_entry_ip(unsigned long fentry_ip)
2604 {
2605 unsigned long ip = ftrace_get_symaddr(fentry_ip);
2606
2607 return ip ? : fentry_ip;
2608 }
2609
copy_user_syms(struct user_syms * us,unsigned long __user * usyms,u32 cnt)2610 static int copy_user_syms(struct user_syms *us, unsigned long __user *usyms, u32 cnt)
2611 {
2612 unsigned long __user usymbol;
2613 const char **syms = NULL;
2614 char *buf = NULL, *p;
2615 int err = -ENOMEM;
2616 unsigned int i;
2617
2618 syms = kvmalloc_array(cnt, sizeof(*syms), GFP_KERNEL);
2619 if (!syms)
2620 goto error;
2621
2622 buf = kvmalloc_array(cnt, KSYM_NAME_LEN, GFP_KERNEL);
2623 if (!buf)
2624 goto error;
2625
2626 for (p = buf, i = 0; i < cnt; i++) {
2627 if (__get_user(usymbol, usyms + i)) {
2628 err = -EFAULT;
2629 goto error;
2630 }
2631 err = strncpy_from_user(p, (const char __user *) usymbol, KSYM_NAME_LEN);
2632 if (err == KSYM_NAME_LEN)
2633 err = -E2BIG;
2634 if (err < 0)
2635 goto error;
2636 syms[i] = p;
2637 p += err + 1;
2638 }
2639
2640 us->syms = syms;
2641 us->buf = buf;
2642 return 0;
2643
2644 error:
2645 if (err) {
2646 kvfree(syms);
2647 kvfree(buf);
2648 }
2649 return err;
2650 }
2651
kprobe_multi_put_modules(struct module ** mods,u32 cnt)2652 static void kprobe_multi_put_modules(struct module **mods, u32 cnt)
2653 {
2654 u32 i;
2655
2656 for (i = 0; i < cnt; i++)
2657 module_put(mods[i]);
2658 }
2659
free_user_syms(struct user_syms * us)2660 static void free_user_syms(struct user_syms *us)
2661 {
2662 kvfree(us->syms);
2663 kvfree(us->buf);
2664 }
2665
bpf_kprobe_multi_link_release(struct bpf_link * link)2666 static void bpf_kprobe_multi_link_release(struct bpf_link *link)
2667 {
2668 struct bpf_kprobe_multi_link *kmulti_link;
2669
2670 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);
2671 unregister_fprobe(&kmulti_link->fp);
2672 kprobe_multi_put_modules(kmulti_link->mods, kmulti_link->mods_cnt);
2673 }
2674
bpf_kprobe_multi_link_dealloc(struct bpf_link * link)2675 static void bpf_kprobe_multi_link_dealloc(struct bpf_link *link)
2676 {
2677 struct bpf_kprobe_multi_link *kmulti_link;
2678
2679 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);
2680 kvfree(kmulti_link->addrs);
2681 kvfree(kmulti_link->cookies);
2682 kfree(kmulti_link->mods);
2683 kfree(kmulti_link);
2684 }
2685
bpf_kprobe_multi_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)2686 static int bpf_kprobe_multi_link_fill_link_info(const struct bpf_link *link,
2687 struct bpf_link_info *info)
2688 {
2689 u64 __user *ucookies = u64_to_user_ptr(info->kprobe_multi.cookies);
2690 u64 __user *uaddrs = u64_to_user_ptr(info->kprobe_multi.addrs);
2691 struct bpf_kprobe_multi_link *kmulti_link;
2692 u32 ucount = info->kprobe_multi.count;
2693 int err = 0, i;
2694
2695 if (!uaddrs ^ !ucount)
2696 return -EINVAL;
2697 if (ucookies && !ucount)
2698 return -EINVAL;
2699
2700 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);
2701 info->kprobe_multi.count = kmulti_link->cnt;
2702 info->kprobe_multi.flags = kmulti_link->flags;
2703 info->kprobe_multi.missed = kmulti_link->fp.nmissed;
2704
2705 if (!uaddrs)
2706 return 0;
2707 if (ucount < kmulti_link->cnt)
2708 err = -ENOSPC;
2709 else
2710 ucount = kmulti_link->cnt;
2711
2712 if (ucookies) {
2713 if (kmulti_link->cookies) {
2714 if (copy_to_user(ucookies, kmulti_link->cookies, ucount * sizeof(u64)))
2715 return -EFAULT;
2716 } else {
2717 for (i = 0; i < ucount; i++) {
2718 if (put_user(0, ucookies + i))
2719 return -EFAULT;
2720 }
2721 }
2722 }
2723
2724 if (kallsyms_show_value(current_cred())) {
2725 if (copy_to_user(uaddrs, kmulti_link->addrs, ucount * sizeof(u64)))
2726 return -EFAULT;
2727 } else {
2728 for (i = 0; i < ucount; i++) {
2729 if (put_user(0, uaddrs + i))
2730 return -EFAULT;
2731 }
2732 }
2733 return err;
2734 }
2735
2736 static const struct bpf_link_ops bpf_kprobe_multi_link_lops = {
2737 .release = bpf_kprobe_multi_link_release,
2738 .dealloc_deferred = bpf_kprobe_multi_link_dealloc,
2739 .fill_link_info = bpf_kprobe_multi_link_fill_link_info,
2740 };
2741
bpf_kprobe_multi_cookie_swap(void * a,void * b,int size,const void * priv)2742 static void bpf_kprobe_multi_cookie_swap(void *a, void *b, int size, const void *priv)
2743 {
2744 const struct bpf_kprobe_multi_link *link = priv;
2745 unsigned long *addr_a = a, *addr_b = b;
2746 u64 *cookie_a, *cookie_b;
2747
2748 cookie_a = link->cookies + (addr_a - link->addrs);
2749 cookie_b = link->cookies + (addr_b - link->addrs);
2750
2751 /* swap addr_a/addr_b and cookie_a/cookie_b values */
2752 swap(*addr_a, *addr_b);
2753 swap(*cookie_a, *cookie_b);
2754 }
2755
bpf_kprobe_multi_addrs_cmp(const void * a,const void * b)2756 static int bpf_kprobe_multi_addrs_cmp(const void *a, const void *b)
2757 {
2758 const unsigned long *addr_a = a, *addr_b = b;
2759
2760 if (*addr_a == *addr_b)
2761 return 0;
2762 return *addr_a < *addr_b ? -1 : 1;
2763 }
2764
bpf_kprobe_multi_cookie_cmp(const void * a,const void * b,const void * priv)2765 static int bpf_kprobe_multi_cookie_cmp(const void *a, const void *b, const void *priv)
2766 {
2767 return bpf_kprobe_multi_addrs_cmp(a, b);
2768 }
2769
bpf_kprobe_multi_cookie(struct bpf_run_ctx * ctx)2770 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx)
2771 {
2772 struct bpf_kprobe_multi_run_ctx *run_ctx;
2773 struct bpf_kprobe_multi_link *link;
2774 u64 *cookie, entry_ip;
2775 unsigned long *addr;
2776
2777 if (WARN_ON_ONCE(!ctx))
2778 return 0;
2779 run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx,
2780 session_ctx.run_ctx);
2781 link = run_ctx->link;
2782 if (!link->cookies)
2783 return 0;
2784 entry_ip = run_ctx->entry_ip;
2785 addr = bsearch(&entry_ip, link->addrs, link->cnt, sizeof(entry_ip),
2786 bpf_kprobe_multi_addrs_cmp);
2787 if (!addr)
2788 return 0;
2789 cookie = link->cookies + (addr - link->addrs);
2790 return *cookie;
2791 }
2792
bpf_kprobe_multi_entry_ip(struct bpf_run_ctx * ctx)2793 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
2794 {
2795 struct bpf_kprobe_multi_run_ctx *run_ctx;
2796
2797 run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx,
2798 session_ctx.run_ctx);
2799 return run_ctx->entry_ip;
2800 }
2801
2802 static int
kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link * link,unsigned long entry_ip,struct ftrace_regs * fregs,bool is_return,void * data)2803 kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link,
2804 unsigned long entry_ip, struct ftrace_regs *fregs,
2805 bool is_return, void *data)
2806 {
2807 struct bpf_kprobe_multi_run_ctx run_ctx = {
2808 .session_ctx = {
2809 .is_return = is_return,
2810 .data = data,
2811 },
2812 .link = link,
2813 .entry_ip = entry_ip,
2814 };
2815 struct bpf_run_ctx *old_run_ctx;
2816 struct pt_regs *regs;
2817 int err;
2818
2819 if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) {
2820 bpf_prog_inc_misses_counter(link->link.prog);
2821 err = 1;
2822 goto out;
2823 }
2824
2825 migrate_disable();
2826 rcu_read_lock();
2827 regs = ftrace_partial_regs(fregs, bpf_kprobe_multi_pt_regs_ptr());
2828 old_run_ctx = bpf_set_run_ctx(&run_ctx.session_ctx.run_ctx);
2829 err = bpf_prog_run(link->link.prog, regs);
2830 bpf_reset_run_ctx(old_run_ctx);
2831 rcu_read_unlock();
2832 migrate_enable();
2833
2834 out:
2835 __this_cpu_dec(bpf_prog_active);
2836 return err;
2837 }
2838
2839 static int
kprobe_multi_link_handler(struct fprobe * fp,unsigned long fentry_ip,unsigned long ret_ip,struct ftrace_regs * fregs,void * data)2840 kprobe_multi_link_handler(struct fprobe *fp, unsigned long fentry_ip,
2841 unsigned long ret_ip, struct ftrace_regs *fregs,
2842 void *data)
2843 {
2844 struct bpf_kprobe_multi_link *link;
2845 int err;
2846
2847 link = container_of(fp, struct bpf_kprobe_multi_link, fp);
2848 err = kprobe_multi_link_prog_run(link, ftrace_get_entry_ip(fentry_ip),
2849 fregs, false, data);
2850 return is_kprobe_session(link->link.prog) ? err : 0;
2851 }
2852
2853 static void
kprobe_multi_link_exit_handler(struct fprobe * fp,unsigned long fentry_ip,unsigned long ret_ip,struct ftrace_regs * fregs,void * data)2854 kprobe_multi_link_exit_handler(struct fprobe *fp, unsigned long fentry_ip,
2855 unsigned long ret_ip, struct ftrace_regs *fregs,
2856 void *data)
2857 {
2858 struct bpf_kprobe_multi_link *link;
2859
2860 link = container_of(fp, struct bpf_kprobe_multi_link, fp);
2861 kprobe_multi_link_prog_run(link, ftrace_get_entry_ip(fentry_ip),
2862 fregs, true, data);
2863 }
2864
symbols_cmp_r(const void * a,const void * b,const void * priv)2865 static int symbols_cmp_r(const void *a, const void *b, const void *priv)
2866 {
2867 const char **str_a = (const char **) a;
2868 const char **str_b = (const char **) b;
2869
2870 return strcmp(*str_a, *str_b);
2871 }
2872
2873 struct multi_symbols_sort {
2874 const char **funcs;
2875 u64 *cookies;
2876 };
2877
symbols_swap_r(void * a,void * b,int size,const void * priv)2878 static void symbols_swap_r(void *a, void *b, int size, const void *priv)
2879 {
2880 const struct multi_symbols_sort *data = priv;
2881 const char **name_a = a, **name_b = b;
2882
2883 swap(*name_a, *name_b);
2884
2885 /* If defined, swap also related cookies. */
2886 if (data->cookies) {
2887 u64 *cookie_a, *cookie_b;
2888
2889 cookie_a = data->cookies + (name_a - data->funcs);
2890 cookie_b = data->cookies + (name_b - data->funcs);
2891 swap(*cookie_a, *cookie_b);
2892 }
2893 }
2894
2895 struct modules_array {
2896 struct module **mods;
2897 int mods_cnt;
2898 int mods_cap;
2899 };
2900
add_module(struct modules_array * arr,struct module * mod)2901 static int add_module(struct modules_array *arr, struct module *mod)
2902 {
2903 struct module **mods;
2904
2905 if (arr->mods_cnt == arr->mods_cap) {
2906 arr->mods_cap = max(16, arr->mods_cap * 3 / 2);
2907 mods = krealloc_array(arr->mods, arr->mods_cap, sizeof(*mods), GFP_KERNEL);
2908 if (!mods)
2909 return -ENOMEM;
2910 arr->mods = mods;
2911 }
2912
2913 arr->mods[arr->mods_cnt] = mod;
2914 arr->mods_cnt++;
2915 return 0;
2916 }
2917
has_module(struct modules_array * arr,struct module * mod)2918 static bool has_module(struct modules_array *arr, struct module *mod)
2919 {
2920 int i;
2921
2922 for (i = arr->mods_cnt - 1; i >= 0; i--) {
2923 if (arr->mods[i] == mod)
2924 return true;
2925 }
2926 return false;
2927 }
2928
get_modules_for_addrs(struct module *** mods,unsigned long * addrs,u32 addrs_cnt)2929 static int get_modules_for_addrs(struct module ***mods, unsigned long *addrs, u32 addrs_cnt)
2930 {
2931 struct modules_array arr = {};
2932 u32 i, err = 0;
2933
2934 for (i = 0; i < addrs_cnt; i++) {
2935 struct module *mod;
2936
2937 preempt_disable();
2938 mod = __module_address(addrs[i]);
2939 /* Either no module or we it's already stored */
2940 if (!mod || has_module(&arr, mod)) {
2941 preempt_enable();
2942 continue;
2943 }
2944 if (!try_module_get(mod))
2945 err = -EINVAL;
2946 preempt_enable();
2947 if (err)
2948 break;
2949 err = add_module(&arr, mod);
2950 if (err) {
2951 module_put(mod);
2952 break;
2953 }
2954 }
2955
2956 /* We return either err < 0 in case of error, ... */
2957 if (err) {
2958 kprobe_multi_put_modules(arr.mods, arr.mods_cnt);
2959 kfree(arr.mods);
2960 return err;
2961 }
2962
2963 /* or number of modules found if everything is ok. */
2964 *mods = arr.mods;
2965 return arr.mods_cnt;
2966 }
2967
addrs_check_error_injection_list(unsigned long * addrs,u32 cnt)2968 static int addrs_check_error_injection_list(unsigned long *addrs, u32 cnt)
2969 {
2970 u32 i;
2971
2972 for (i = 0; i < cnt; i++) {
2973 if (!within_error_injection_list(addrs[i]))
2974 return -EINVAL;
2975 }
2976 return 0;
2977 }
2978
bpf_kprobe_multi_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)2979 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
2980 {
2981 struct bpf_kprobe_multi_link *link = NULL;
2982 struct bpf_link_primer link_primer;
2983 void __user *ucookies;
2984 unsigned long *addrs;
2985 u32 flags, cnt, size;
2986 void __user *uaddrs;
2987 u64 *cookies = NULL;
2988 void __user *usyms;
2989 int err;
2990
2991 /* no support for 32bit archs yet */
2992 if (sizeof(u64) != sizeof(void *))
2993 return -EOPNOTSUPP;
2994
2995 if (!is_kprobe_multi(prog))
2996 return -EINVAL;
2997
2998 flags = attr->link_create.kprobe_multi.flags;
2999 if (flags & ~BPF_F_KPROBE_MULTI_RETURN)
3000 return -EINVAL;
3001
3002 uaddrs = u64_to_user_ptr(attr->link_create.kprobe_multi.addrs);
3003 usyms = u64_to_user_ptr(attr->link_create.kprobe_multi.syms);
3004 if (!!uaddrs == !!usyms)
3005 return -EINVAL;
3006
3007 cnt = attr->link_create.kprobe_multi.cnt;
3008 if (!cnt)
3009 return -EINVAL;
3010 if (cnt > MAX_KPROBE_MULTI_CNT)
3011 return -E2BIG;
3012
3013 size = cnt * sizeof(*addrs);
3014 addrs = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL);
3015 if (!addrs)
3016 return -ENOMEM;
3017
3018 ucookies = u64_to_user_ptr(attr->link_create.kprobe_multi.cookies);
3019 if (ucookies) {
3020 cookies = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL);
3021 if (!cookies) {
3022 err = -ENOMEM;
3023 goto error;
3024 }
3025 if (copy_from_user(cookies, ucookies, size)) {
3026 err = -EFAULT;
3027 goto error;
3028 }
3029 }
3030
3031 if (uaddrs) {
3032 if (copy_from_user(addrs, uaddrs, size)) {
3033 err = -EFAULT;
3034 goto error;
3035 }
3036 } else {
3037 struct multi_symbols_sort data = {
3038 .cookies = cookies,
3039 };
3040 struct user_syms us;
3041
3042 err = copy_user_syms(&us, usyms, cnt);
3043 if (err)
3044 goto error;
3045
3046 if (cookies)
3047 data.funcs = us.syms;
3048
3049 sort_r(us.syms, cnt, sizeof(*us.syms), symbols_cmp_r,
3050 symbols_swap_r, &data);
3051
3052 err = ftrace_lookup_symbols(us.syms, cnt, addrs);
3053 free_user_syms(&us);
3054 if (err)
3055 goto error;
3056 }
3057
3058 if (prog->kprobe_override && addrs_check_error_injection_list(addrs, cnt)) {
3059 err = -EINVAL;
3060 goto error;
3061 }
3062
3063 link = kzalloc(sizeof(*link), GFP_KERNEL);
3064 if (!link) {
3065 err = -ENOMEM;
3066 goto error;
3067 }
3068
3069 bpf_link_init(&link->link, BPF_LINK_TYPE_KPROBE_MULTI,
3070 &bpf_kprobe_multi_link_lops, prog);
3071
3072 err = bpf_link_prime(&link->link, &link_primer);
3073 if (err)
3074 goto error;
3075
3076 if (!(flags & BPF_F_KPROBE_MULTI_RETURN))
3077 link->fp.entry_handler = kprobe_multi_link_handler;
3078 if ((flags & BPF_F_KPROBE_MULTI_RETURN) || is_kprobe_session(prog))
3079 link->fp.exit_handler = kprobe_multi_link_exit_handler;
3080 if (is_kprobe_session(prog))
3081 link->fp.entry_data_size = sizeof(u64);
3082
3083 link->addrs = addrs;
3084 link->cookies = cookies;
3085 link->cnt = cnt;
3086 link->flags = flags;
3087
3088 if (cookies) {
3089 /*
3090 * Sorting addresses will trigger sorting cookies as well
3091 * (check bpf_kprobe_multi_cookie_swap). This way we can
3092 * find cookie based on the address in bpf_get_attach_cookie
3093 * helper.
3094 */
3095 sort_r(addrs, cnt, sizeof(*addrs),
3096 bpf_kprobe_multi_cookie_cmp,
3097 bpf_kprobe_multi_cookie_swap,
3098 link);
3099 }
3100
3101 err = get_modules_for_addrs(&link->mods, addrs, cnt);
3102 if (err < 0) {
3103 bpf_link_cleanup(&link_primer);
3104 return err;
3105 }
3106 link->mods_cnt = err;
3107
3108 err = register_fprobe_ips(&link->fp, addrs, cnt);
3109 if (err) {
3110 kprobe_multi_put_modules(link->mods, link->mods_cnt);
3111 bpf_link_cleanup(&link_primer);
3112 return err;
3113 }
3114
3115 return bpf_link_settle(&link_primer);
3116
3117 error:
3118 kfree(link);
3119 kvfree(addrs);
3120 kvfree(cookies);
3121 return err;
3122 }
3123 #else /* !CONFIG_FPROBE */
bpf_kprobe_multi_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)3124 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
3125 {
3126 return -EOPNOTSUPP;
3127 }
bpf_kprobe_multi_cookie(struct bpf_run_ctx * ctx)3128 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx)
3129 {
3130 return 0;
3131 }
bpf_kprobe_multi_entry_ip(struct bpf_run_ctx * ctx)3132 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
3133 {
3134 return 0;
3135 }
3136 #endif
3137
3138 #ifdef CONFIG_UPROBES
3139 struct bpf_uprobe_multi_link;
3140
3141 struct bpf_uprobe {
3142 struct bpf_uprobe_multi_link *link;
3143 loff_t offset;
3144 unsigned long ref_ctr_offset;
3145 u64 cookie;
3146 struct uprobe *uprobe;
3147 struct uprobe_consumer consumer;
3148 bool session;
3149 };
3150
3151 struct bpf_uprobe_multi_link {
3152 struct path path;
3153 struct bpf_link link;
3154 u32 cnt;
3155 u32 flags;
3156 struct bpf_uprobe *uprobes;
3157 struct task_struct *task;
3158 };
3159
3160 struct bpf_uprobe_multi_run_ctx {
3161 struct bpf_session_run_ctx session_ctx;
3162 unsigned long entry_ip;
3163 struct bpf_uprobe *uprobe;
3164 };
3165
bpf_uprobe_unregister(struct bpf_uprobe * uprobes,u32 cnt)3166 static void bpf_uprobe_unregister(struct bpf_uprobe *uprobes, u32 cnt)
3167 {
3168 u32 i;
3169
3170 for (i = 0; i < cnt; i++)
3171 uprobe_unregister_nosync(uprobes[i].uprobe, &uprobes[i].consumer);
3172
3173 if (cnt)
3174 uprobe_unregister_sync();
3175 }
3176
bpf_uprobe_multi_link_release(struct bpf_link * link)3177 static void bpf_uprobe_multi_link_release(struct bpf_link *link)
3178 {
3179 struct bpf_uprobe_multi_link *umulti_link;
3180
3181 umulti_link = container_of(link, struct bpf_uprobe_multi_link, link);
3182 bpf_uprobe_unregister(umulti_link->uprobes, umulti_link->cnt);
3183 if (umulti_link->task)
3184 put_task_struct(umulti_link->task);
3185 path_put(&umulti_link->path);
3186 }
3187
bpf_uprobe_multi_link_dealloc(struct bpf_link * link)3188 static void bpf_uprobe_multi_link_dealloc(struct bpf_link *link)
3189 {
3190 struct bpf_uprobe_multi_link *umulti_link;
3191
3192 umulti_link = container_of(link, struct bpf_uprobe_multi_link, link);
3193 kvfree(umulti_link->uprobes);
3194 kfree(umulti_link);
3195 }
3196
bpf_uprobe_multi_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)3197 static int bpf_uprobe_multi_link_fill_link_info(const struct bpf_link *link,
3198 struct bpf_link_info *info)
3199 {
3200 u64 __user *uref_ctr_offsets = u64_to_user_ptr(info->uprobe_multi.ref_ctr_offsets);
3201 u64 __user *ucookies = u64_to_user_ptr(info->uprobe_multi.cookies);
3202 u64 __user *uoffsets = u64_to_user_ptr(info->uprobe_multi.offsets);
3203 u64 __user *upath = u64_to_user_ptr(info->uprobe_multi.path);
3204 u32 upath_size = info->uprobe_multi.path_size;
3205 struct bpf_uprobe_multi_link *umulti_link;
3206 u32 ucount = info->uprobe_multi.count;
3207 int err = 0, i;
3208 char *p, *buf;
3209 long left = 0;
3210
3211 if (!upath ^ !upath_size)
3212 return -EINVAL;
3213
3214 if ((uoffsets || uref_ctr_offsets || ucookies) && !ucount)
3215 return -EINVAL;
3216
3217 umulti_link = container_of(link, struct bpf_uprobe_multi_link, link);
3218 info->uprobe_multi.count = umulti_link->cnt;
3219 info->uprobe_multi.flags = umulti_link->flags;
3220 info->uprobe_multi.pid = umulti_link->task ?
3221 task_pid_nr_ns(umulti_link->task, task_active_pid_ns(current)) : 0;
3222
3223 upath_size = upath_size ? min_t(u32, upath_size, PATH_MAX) : PATH_MAX;
3224 buf = kmalloc(upath_size, GFP_KERNEL);
3225 if (!buf)
3226 return -ENOMEM;
3227 p = d_path(&umulti_link->path, buf, upath_size);
3228 if (IS_ERR(p)) {
3229 kfree(buf);
3230 return PTR_ERR(p);
3231 }
3232 upath_size = buf + upath_size - p;
3233
3234 if (upath)
3235 left = copy_to_user(upath, p, upath_size);
3236 kfree(buf);
3237 if (left)
3238 return -EFAULT;
3239 info->uprobe_multi.path_size = upath_size;
3240
3241 if (!uoffsets && !ucookies && !uref_ctr_offsets)
3242 return 0;
3243
3244 if (ucount < umulti_link->cnt)
3245 err = -ENOSPC;
3246 else
3247 ucount = umulti_link->cnt;
3248
3249 for (i = 0; i < ucount; i++) {
3250 if (uoffsets &&
3251 put_user(umulti_link->uprobes[i].offset, uoffsets + i))
3252 return -EFAULT;
3253 if (uref_ctr_offsets &&
3254 put_user(umulti_link->uprobes[i].ref_ctr_offset, uref_ctr_offsets + i))
3255 return -EFAULT;
3256 if (ucookies &&
3257 put_user(umulti_link->uprobes[i].cookie, ucookies + i))
3258 return -EFAULT;
3259 }
3260
3261 return err;
3262 }
3263
3264 static const struct bpf_link_ops bpf_uprobe_multi_link_lops = {
3265 .release = bpf_uprobe_multi_link_release,
3266 .dealloc_deferred = bpf_uprobe_multi_link_dealloc,
3267 .fill_link_info = bpf_uprobe_multi_link_fill_link_info,
3268 };
3269
uprobe_prog_run(struct bpf_uprobe * uprobe,unsigned long entry_ip,struct pt_regs * regs,bool is_return,void * data)3270 static int uprobe_prog_run(struct bpf_uprobe *uprobe,
3271 unsigned long entry_ip,
3272 struct pt_regs *regs,
3273 bool is_return, void *data)
3274 {
3275 struct bpf_uprobe_multi_link *link = uprobe->link;
3276 struct bpf_uprobe_multi_run_ctx run_ctx = {
3277 .session_ctx = {
3278 .is_return = is_return,
3279 .data = data,
3280 },
3281 .entry_ip = entry_ip,
3282 .uprobe = uprobe,
3283 };
3284 struct bpf_prog *prog = link->link.prog;
3285 bool sleepable = prog->sleepable;
3286 struct bpf_run_ctx *old_run_ctx;
3287 int err;
3288
3289 if (link->task && !same_thread_group(current, link->task))
3290 return 0;
3291
3292 if (sleepable)
3293 rcu_read_lock_trace();
3294 else
3295 rcu_read_lock();
3296
3297 migrate_disable();
3298
3299 old_run_ctx = bpf_set_run_ctx(&run_ctx.session_ctx.run_ctx);
3300 err = bpf_prog_run(link->link.prog, regs);
3301 bpf_reset_run_ctx(old_run_ctx);
3302
3303 migrate_enable();
3304
3305 if (sleepable)
3306 rcu_read_unlock_trace();
3307 else
3308 rcu_read_unlock();
3309 return err;
3310 }
3311
3312 static bool
uprobe_multi_link_filter(struct uprobe_consumer * con,struct mm_struct * mm)3313 uprobe_multi_link_filter(struct uprobe_consumer *con, struct mm_struct *mm)
3314 {
3315 struct bpf_uprobe *uprobe;
3316
3317 uprobe = container_of(con, struct bpf_uprobe, consumer);
3318 return uprobe->link->task->mm == mm;
3319 }
3320
3321 static int
uprobe_multi_link_handler(struct uprobe_consumer * con,struct pt_regs * regs,__u64 * data)3322 uprobe_multi_link_handler(struct uprobe_consumer *con, struct pt_regs *regs,
3323 __u64 *data)
3324 {
3325 struct bpf_uprobe *uprobe;
3326 int ret;
3327
3328 uprobe = container_of(con, struct bpf_uprobe, consumer);
3329 ret = uprobe_prog_run(uprobe, instruction_pointer(regs), regs, false, data);
3330 if (uprobe->session)
3331 return ret ? UPROBE_HANDLER_IGNORE : 0;
3332 return 0;
3333 }
3334
3335 static int
uprobe_multi_link_ret_handler(struct uprobe_consumer * con,unsigned long func,struct pt_regs * regs,__u64 * data)3336 uprobe_multi_link_ret_handler(struct uprobe_consumer *con, unsigned long func, struct pt_regs *regs,
3337 __u64 *data)
3338 {
3339 struct bpf_uprobe *uprobe;
3340
3341 uprobe = container_of(con, struct bpf_uprobe, consumer);
3342 uprobe_prog_run(uprobe, func, regs, true, data);
3343 return 0;
3344 }
3345
bpf_uprobe_multi_entry_ip(struct bpf_run_ctx * ctx)3346 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
3347 {
3348 struct bpf_uprobe_multi_run_ctx *run_ctx;
3349
3350 run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx,
3351 session_ctx.run_ctx);
3352 return run_ctx->entry_ip;
3353 }
3354
bpf_uprobe_multi_cookie(struct bpf_run_ctx * ctx)3355 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx)
3356 {
3357 struct bpf_uprobe_multi_run_ctx *run_ctx;
3358
3359 run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx,
3360 session_ctx.run_ctx);
3361 return run_ctx->uprobe->cookie;
3362 }
3363
bpf_uprobe_multi_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)3364 int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
3365 {
3366 struct bpf_uprobe_multi_link *link = NULL;
3367 unsigned long __user *uref_ctr_offsets;
3368 struct bpf_link_primer link_primer;
3369 struct bpf_uprobe *uprobes = NULL;
3370 struct task_struct *task = NULL;
3371 unsigned long __user *uoffsets;
3372 u64 __user *ucookies;
3373 void __user *upath;
3374 u32 flags, cnt, i;
3375 struct path path;
3376 char *name;
3377 pid_t pid;
3378 int err;
3379
3380 /* no support for 32bit archs yet */
3381 if (sizeof(u64) != sizeof(void *))
3382 return -EOPNOTSUPP;
3383
3384 if (!is_uprobe_multi(prog))
3385 return -EINVAL;
3386
3387 flags = attr->link_create.uprobe_multi.flags;
3388 if (flags & ~BPF_F_UPROBE_MULTI_RETURN)
3389 return -EINVAL;
3390
3391 /*
3392 * path, offsets and cnt are mandatory,
3393 * ref_ctr_offsets and cookies are optional
3394 */
3395 upath = u64_to_user_ptr(attr->link_create.uprobe_multi.path);
3396 uoffsets = u64_to_user_ptr(attr->link_create.uprobe_multi.offsets);
3397 cnt = attr->link_create.uprobe_multi.cnt;
3398 pid = attr->link_create.uprobe_multi.pid;
3399
3400 if (!upath || !uoffsets || !cnt || pid < 0)
3401 return -EINVAL;
3402 if (cnt > MAX_UPROBE_MULTI_CNT)
3403 return -E2BIG;
3404
3405 uref_ctr_offsets = u64_to_user_ptr(attr->link_create.uprobe_multi.ref_ctr_offsets);
3406 ucookies = u64_to_user_ptr(attr->link_create.uprobe_multi.cookies);
3407
3408 name = strndup_user(upath, PATH_MAX);
3409 if (IS_ERR(name)) {
3410 err = PTR_ERR(name);
3411 return err;
3412 }
3413
3414 err = kern_path(name, LOOKUP_FOLLOW, &path);
3415 kfree(name);
3416 if (err)
3417 return err;
3418
3419 if (!d_is_reg(path.dentry)) {
3420 err = -EBADF;
3421 goto error_path_put;
3422 }
3423
3424 if (pid) {
3425 task = get_pid_task(find_vpid(pid), PIDTYPE_TGID);
3426 if (!task) {
3427 err = -ESRCH;
3428 goto error_path_put;
3429 }
3430 }
3431
3432 err = -ENOMEM;
3433
3434 link = kzalloc(sizeof(*link), GFP_KERNEL);
3435 uprobes = kvcalloc(cnt, sizeof(*uprobes), GFP_KERNEL);
3436
3437 if (!uprobes || !link)
3438 goto error_free;
3439
3440 for (i = 0; i < cnt; i++) {
3441 if (__get_user(uprobes[i].offset, uoffsets + i)) {
3442 err = -EFAULT;
3443 goto error_free;
3444 }
3445 if (uprobes[i].offset < 0) {
3446 err = -EINVAL;
3447 goto error_free;
3448 }
3449 if (uref_ctr_offsets && __get_user(uprobes[i].ref_ctr_offset, uref_ctr_offsets + i)) {
3450 err = -EFAULT;
3451 goto error_free;
3452 }
3453 if (ucookies && __get_user(uprobes[i].cookie, ucookies + i)) {
3454 err = -EFAULT;
3455 goto error_free;
3456 }
3457
3458 uprobes[i].link = link;
3459
3460 if (!(flags & BPF_F_UPROBE_MULTI_RETURN))
3461 uprobes[i].consumer.handler = uprobe_multi_link_handler;
3462 if (flags & BPF_F_UPROBE_MULTI_RETURN || is_uprobe_session(prog))
3463 uprobes[i].consumer.ret_handler = uprobe_multi_link_ret_handler;
3464 if (is_uprobe_session(prog))
3465 uprobes[i].session = true;
3466 if (pid)
3467 uprobes[i].consumer.filter = uprobe_multi_link_filter;
3468 }
3469
3470 link->cnt = cnt;
3471 link->uprobes = uprobes;
3472 link->path = path;
3473 link->task = task;
3474 link->flags = flags;
3475
3476 bpf_link_init(&link->link, BPF_LINK_TYPE_UPROBE_MULTI,
3477 &bpf_uprobe_multi_link_lops, prog);
3478
3479 for (i = 0; i < cnt; i++) {
3480 uprobes[i].uprobe = uprobe_register(d_real_inode(link->path.dentry),
3481 uprobes[i].offset,
3482 uprobes[i].ref_ctr_offset,
3483 &uprobes[i].consumer);
3484 if (IS_ERR(uprobes[i].uprobe)) {
3485 err = PTR_ERR(uprobes[i].uprobe);
3486 link->cnt = i;
3487 goto error_unregister;
3488 }
3489 }
3490
3491 err = bpf_link_prime(&link->link, &link_primer);
3492 if (err)
3493 goto error_unregister;
3494
3495 return bpf_link_settle(&link_primer);
3496
3497 error_unregister:
3498 bpf_uprobe_unregister(uprobes, link->cnt);
3499
3500 error_free:
3501 kvfree(uprobes);
3502 kfree(link);
3503 if (task)
3504 put_task_struct(task);
3505 error_path_put:
3506 path_put(&path);
3507 return err;
3508 }
3509 #else /* !CONFIG_UPROBES */
bpf_uprobe_multi_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)3510 int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
3511 {
3512 return -EOPNOTSUPP;
3513 }
bpf_uprobe_multi_cookie(struct bpf_run_ctx * ctx)3514 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx)
3515 {
3516 return 0;
3517 }
bpf_uprobe_multi_entry_ip(struct bpf_run_ctx * ctx)3518 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
3519 {
3520 return 0;
3521 }
3522 #endif /* CONFIG_UPROBES */
3523
3524 __bpf_kfunc_start_defs();
3525
bpf_session_is_return(void)3526 __bpf_kfunc bool bpf_session_is_return(void)
3527 {
3528 struct bpf_session_run_ctx *session_ctx;
3529
3530 session_ctx = container_of(current->bpf_ctx, struct bpf_session_run_ctx, run_ctx);
3531 return session_ctx->is_return;
3532 }
3533
bpf_session_cookie(void)3534 __bpf_kfunc __u64 *bpf_session_cookie(void)
3535 {
3536 struct bpf_session_run_ctx *session_ctx;
3537
3538 session_ctx = container_of(current->bpf_ctx, struct bpf_session_run_ctx, run_ctx);
3539 return session_ctx->data;
3540 }
3541
3542 __bpf_kfunc_end_defs();
3543
3544 BTF_KFUNCS_START(kprobe_multi_kfunc_set_ids)
BTF_ID_FLAGS(func,bpf_session_is_return)3545 BTF_ID_FLAGS(func, bpf_session_is_return)
3546 BTF_ID_FLAGS(func, bpf_session_cookie)
3547 BTF_KFUNCS_END(kprobe_multi_kfunc_set_ids)
3548
3549 static int bpf_kprobe_multi_filter(const struct bpf_prog *prog, u32 kfunc_id)
3550 {
3551 if (!btf_id_set8_contains(&kprobe_multi_kfunc_set_ids, kfunc_id))
3552 return 0;
3553
3554 if (!is_kprobe_session(prog) && !is_uprobe_session(prog))
3555 return -EACCES;
3556
3557 return 0;
3558 }
3559
3560 static const struct btf_kfunc_id_set bpf_kprobe_multi_kfunc_set = {
3561 .owner = THIS_MODULE,
3562 .set = &kprobe_multi_kfunc_set_ids,
3563 .filter = bpf_kprobe_multi_filter,
3564 };
3565
bpf_kprobe_multi_kfuncs_init(void)3566 static int __init bpf_kprobe_multi_kfuncs_init(void)
3567 {
3568 return register_btf_kfunc_id_set(BPF_PROG_TYPE_KPROBE, &bpf_kprobe_multi_kfunc_set);
3569 }
3570
3571 late_initcall(bpf_kprobe_multi_kfuncs_init);
3572
3573 __bpf_kfunc_start_defs();
3574
bpf_send_signal_task(struct task_struct * task,int sig,enum pid_type type,u64 value)3575 __bpf_kfunc int bpf_send_signal_task(struct task_struct *task, int sig, enum pid_type type,
3576 u64 value)
3577 {
3578 if (type != PIDTYPE_PID && type != PIDTYPE_TGID)
3579 return -EINVAL;
3580
3581 return bpf_send_signal_common(sig, type, task, value);
3582 }
3583
3584 __bpf_kfunc_end_defs();
3585