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/namei.h>
26
27 #include <net/bpf_sk_storage.h>
28
29 #include <uapi/linux/bpf.h>
30 #include <uapi/linux/btf.h>
31
32 #include <asm/tlb.h>
33
34 #include "trace_probe.h"
35 #include "trace.h"
36
37 #define CREATE_TRACE_POINTS
38 #include "bpf_trace.h"
39
40 #define bpf_event_rcu_dereference(p) \
41 rcu_dereference_protected(p, lockdep_is_held(&bpf_event_mutex))
42
43 #define MAX_UPROBE_MULTI_CNT (1U << 20)
44 #define MAX_KPROBE_MULTI_CNT (1U << 20)
45
46 #ifdef CONFIG_MODULES
47 struct bpf_trace_module {
48 struct module *module;
49 struct list_head list;
50 };
51
52 static LIST_HEAD(bpf_trace_modules);
53 static DEFINE_MUTEX(bpf_module_mutex);
54
bpf_get_raw_tracepoint_module(const char * name)55 static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name)
56 {
57 struct bpf_raw_event_map *btp, *ret = NULL;
58 struct bpf_trace_module *btm;
59 unsigned int i;
60
61 mutex_lock(&bpf_module_mutex);
62 list_for_each_entry(btm, &bpf_trace_modules, list) {
63 for (i = 0; i < btm->module->num_bpf_raw_events; ++i) {
64 btp = &btm->module->bpf_raw_events[i];
65 if (!strcmp(btp->tp->name, name)) {
66 if (try_module_get(btm->module))
67 ret = btp;
68 goto out;
69 }
70 }
71 }
72 out:
73 mutex_unlock(&bpf_module_mutex);
74 return ret;
75 }
76 #else
bpf_get_raw_tracepoint_module(const char * name)77 static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name)
78 {
79 return NULL;
80 }
81 #endif /* CONFIG_MODULES */
82
83 u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
84 u64 bpf_get_stack(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
85
86 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size,
87 u64 flags, const struct btf **btf,
88 s32 *btf_id);
89 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx);
90 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx);
91
92 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx);
93 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx);
94
95 /**
96 * trace_call_bpf - invoke BPF program
97 * @call: tracepoint event
98 * @ctx: opaque context pointer
99 *
100 * kprobe handlers execute BPF programs via this helper.
101 * Can be used from static tracepoints in the future.
102 *
103 * Return: BPF programs always return an integer which is interpreted by
104 * kprobe handler as:
105 * 0 - return from kprobe (event is filtered out)
106 * 1 - store kprobe event into ring buffer
107 * Other values are reserved and currently alias to 1
108 */
trace_call_bpf(struct trace_event_call * call,void * ctx)109 unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx)
110 {
111 unsigned int ret;
112
113 cant_sleep();
114
115 if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) {
116 /*
117 * since some bpf program is already running on this cpu,
118 * don't call into another bpf program (same or different)
119 * and don't send kprobe event into ring-buffer,
120 * so return zero here
121 */
122 rcu_read_lock();
123 bpf_prog_inc_misses_counters(rcu_dereference(call->prog_array));
124 rcu_read_unlock();
125 ret = 0;
126 goto out;
127 }
128
129 /*
130 * Instead of moving rcu_read_lock/rcu_dereference/rcu_read_unlock
131 * to all call sites, we did a bpf_prog_array_valid() there to check
132 * whether call->prog_array is empty or not, which is
133 * a heuristic to speed up execution.
134 *
135 * If bpf_prog_array_valid() fetched prog_array was
136 * non-NULL, we go into trace_call_bpf() and do the actual
137 * proper rcu_dereference() under RCU lock.
138 * If it turns out that prog_array is NULL then, we bail out.
139 * For the opposite, if the bpf_prog_array_valid() fetched pointer
140 * was NULL, you'll skip the prog_array with the risk of missing
141 * out of events when it was updated in between this and the
142 * rcu_dereference() which is accepted risk.
143 */
144 rcu_read_lock();
145 ret = bpf_prog_run_array(rcu_dereference(call->prog_array),
146 ctx, bpf_prog_run);
147 rcu_read_unlock();
148
149 out:
150 __this_cpu_dec(bpf_prog_active);
151
152 return ret;
153 }
154
155 #ifdef CONFIG_BPF_KPROBE_OVERRIDE
BPF_CALL_2(bpf_override_return,struct pt_regs *,regs,unsigned long,rc)156 BPF_CALL_2(bpf_override_return, struct pt_regs *, regs, unsigned long, rc)
157 {
158 regs_set_return_value(regs, rc);
159 override_function_with_return(regs);
160 return 0;
161 }
162
163 static const struct bpf_func_proto bpf_override_return_proto = {
164 .func = bpf_override_return,
165 .gpl_only = true,
166 .ret_type = RET_INTEGER,
167 .arg1_type = ARG_PTR_TO_CTX,
168 .arg2_type = ARG_ANYTHING,
169 };
170 #endif
171
172 static __always_inline int
bpf_probe_read_user_common(void * dst,u32 size,const void __user * unsafe_ptr)173 bpf_probe_read_user_common(void *dst, u32 size, const void __user *unsafe_ptr)
174 {
175 int ret;
176
177 ret = copy_from_user_nofault(dst, unsafe_ptr, size);
178 if (unlikely(ret < 0))
179 memset(dst, 0, size);
180 return ret;
181 }
182
BPF_CALL_3(bpf_probe_read_user,void *,dst,u32,size,const void __user *,unsafe_ptr)183 BPF_CALL_3(bpf_probe_read_user, void *, dst, u32, size,
184 const void __user *, unsafe_ptr)
185 {
186 return bpf_probe_read_user_common(dst, size, unsafe_ptr);
187 }
188
189 const struct bpf_func_proto bpf_probe_read_user_proto = {
190 .func = bpf_probe_read_user,
191 .gpl_only = true,
192 .ret_type = RET_INTEGER,
193 .arg1_type = ARG_PTR_TO_UNINIT_MEM,
194 .arg2_type = ARG_CONST_SIZE_OR_ZERO,
195 .arg3_type = ARG_ANYTHING,
196 };
197
198 static __always_inline int
bpf_probe_read_user_str_common(void * dst,u32 size,const void __user * unsafe_ptr)199 bpf_probe_read_user_str_common(void *dst, u32 size,
200 const void __user *unsafe_ptr)
201 {
202 int ret;
203
204 /*
205 * NB: We rely on strncpy_from_user() not copying junk past the NUL
206 * terminator into `dst`.
207 *
208 * strncpy_from_user() does long-sized strides in the fast path. If the
209 * strncpy does not mask out the bytes after the NUL in `unsafe_ptr`,
210 * then there could be junk after the NUL in `dst`. If user takes `dst`
211 * and keys a hash map with it, then semantically identical strings can
212 * occupy multiple entries in the map.
213 */
214 ret = strncpy_from_user_nofault(dst, unsafe_ptr, size);
215 if (unlikely(ret < 0))
216 memset(dst, 0, size);
217 return ret;
218 }
219
BPF_CALL_3(bpf_probe_read_user_str,void *,dst,u32,size,const void __user *,unsafe_ptr)220 BPF_CALL_3(bpf_probe_read_user_str, void *, dst, u32, size,
221 const void __user *, unsafe_ptr)
222 {
223 return bpf_probe_read_user_str_common(dst, size, unsafe_ptr);
224 }
225
226 const struct bpf_func_proto bpf_probe_read_user_str_proto = {
227 .func = bpf_probe_read_user_str,
228 .gpl_only = true,
229 .ret_type = RET_INTEGER,
230 .arg1_type = ARG_PTR_TO_UNINIT_MEM,
231 .arg2_type = ARG_CONST_SIZE_OR_ZERO,
232 .arg3_type = ARG_ANYTHING,
233 };
234
BPF_CALL_3(bpf_probe_read_kernel,void *,dst,u32,size,const void *,unsafe_ptr)235 BPF_CALL_3(bpf_probe_read_kernel, void *, dst, u32, size,
236 const void *, unsafe_ptr)
237 {
238 return bpf_probe_read_kernel_common(dst, size, unsafe_ptr);
239 }
240
241 const struct bpf_func_proto bpf_probe_read_kernel_proto = {
242 .func = bpf_probe_read_kernel,
243 .gpl_only = true,
244 .ret_type = RET_INTEGER,
245 .arg1_type = ARG_PTR_TO_UNINIT_MEM,
246 .arg2_type = ARG_CONST_SIZE_OR_ZERO,
247 .arg3_type = ARG_ANYTHING,
248 };
249
250 static __always_inline int
bpf_probe_read_kernel_str_common(void * dst,u32 size,const void * unsafe_ptr)251 bpf_probe_read_kernel_str_common(void *dst, u32 size, const void *unsafe_ptr)
252 {
253 int ret;
254
255 /*
256 * The strncpy_from_kernel_nofault() call will likely not fill the
257 * entire buffer, but that's okay in this circumstance as we're probing
258 * arbitrary memory anyway similar to bpf_probe_read_*() and might
259 * as well probe the stack. Thus, memory is explicitly cleared
260 * only in error case, so that improper users ignoring return
261 * code altogether don't copy garbage; otherwise length of string
262 * is returned that can be used for bpf_perf_event_output() et al.
263 */
264 ret = strncpy_from_kernel_nofault(dst, unsafe_ptr, size);
265 if (unlikely(ret < 0))
266 memset(dst, 0, size);
267 return ret;
268 }
269
BPF_CALL_3(bpf_probe_read_kernel_str,void *,dst,u32,size,const void *,unsafe_ptr)270 BPF_CALL_3(bpf_probe_read_kernel_str, void *, dst, u32, size,
271 const void *, unsafe_ptr)
272 {
273 return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr);
274 }
275
276 const struct bpf_func_proto bpf_probe_read_kernel_str_proto = {
277 .func = bpf_probe_read_kernel_str,
278 .gpl_only = true,
279 .ret_type = RET_INTEGER,
280 .arg1_type = ARG_PTR_TO_UNINIT_MEM,
281 .arg2_type = ARG_CONST_SIZE_OR_ZERO,
282 .arg3_type = ARG_ANYTHING,
283 };
284
285 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
BPF_CALL_3(bpf_probe_read_compat,void *,dst,u32,size,const void *,unsafe_ptr)286 BPF_CALL_3(bpf_probe_read_compat, void *, dst, u32, size,
287 const void *, unsafe_ptr)
288 {
289 if ((unsigned long)unsafe_ptr < TASK_SIZE) {
290 return bpf_probe_read_user_common(dst, size,
291 (__force void __user *)unsafe_ptr);
292 }
293 return bpf_probe_read_kernel_common(dst, size, unsafe_ptr);
294 }
295
296 static const struct bpf_func_proto bpf_probe_read_compat_proto = {
297 .func = bpf_probe_read_compat,
298 .gpl_only = true,
299 .ret_type = RET_INTEGER,
300 .arg1_type = ARG_PTR_TO_UNINIT_MEM,
301 .arg2_type = ARG_CONST_SIZE_OR_ZERO,
302 .arg3_type = ARG_ANYTHING,
303 };
304
BPF_CALL_3(bpf_probe_read_compat_str,void *,dst,u32,size,const void *,unsafe_ptr)305 BPF_CALL_3(bpf_probe_read_compat_str, void *, dst, u32, size,
306 const void *, unsafe_ptr)
307 {
308 if ((unsigned long)unsafe_ptr < TASK_SIZE) {
309 return bpf_probe_read_user_str_common(dst, size,
310 (__force void __user *)unsafe_ptr);
311 }
312 return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr);
313 }
314
315 static const struct bpf_func_proto bpf_probe_read_compat_str_proto = {
316 .func = bpf_probe_read_compat_str,
317 .gpl_only = true,
318 .ret_type = RET_INTEGER,
319 .arg1_type = ARG_PTR_TO_UNINIT_MEM,
320 .arg2_type = ARG_CONST_SIZE_OR_ZERO,
321 .arg3_type = ARG_ANYTHING,
322 };
323 #endif /* CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE */
324
BPF_CALL_3(bpf_probe_write_user,void __user *,unsafe_ptr,const void *,src,u32,size)325 BPF_CALL_3(bpf_probe_write_user, void __user *, unsafe_ptr, const void *, src,
326 u32, size)
327 {
328 /*
329 * Ensure we're in user context which is safe for the helper to
330 * run. This helper has no business in a kthread.
331 *
332 * access_ok() should prevent writing to non-user memory, but in
333 * some situations (nommu, temporary switch, etc) access_ok() does
334 * not provide enough validation, hence the check on KERNEL_DS.
335 *
336 * nmi_uaccess_okay() ensures the probe is not run in an interim
337 * state, when the task or mm are switched. This is specifically
338 * required to prevent the use of temporary mm.
339 */
340
341 if (unlikely(in_interrupt() ||
342 current->flags & (PF_KTHREAD | PF_EXITING)))
343 return -EPERM;
344 if (unlikely(!nmi_uaccess_okay()))
345 return -EPERM;
346
347 return copy_to_user_nofault(unsafe_ptr, src, size);
348 }
349
350 static const struct bpf_func_proto bpf_probe_write_user_proto = {
351 .func = bpf_probe_write_user,
352 .gpl_only = true,
353 .ret_type = RET_INTEGER,
354 .arg1_type = ARG_ANYTHING,
355 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
356 .arg3_type = ARG_CONST_SIZE,
357 };
358
359 #define MAX_TRACE_PRINTK_VARARGS 3
360 #define BPF_TRACE_PRINTK_SIZE 1024
361
BPF_CALL_5(bpf_trace_printk,char *,fmt,u32,fmt_size,u64,arg1,u64,arg2,u64,arg3)362 BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1,
363 u64, arg2, u64, arg3)
364 {
365 u64 args[MAX_TRACE_PRINTK_VARARGS] = { arg1, arg2, arg3 };
366 struct bpf_bprintf_data data = {
367 .get_bin_args = true,
368 .get_buf = true,
369 };
370 int ret;
371
372 ret = bpf_bprintf_prepare(fmt, fmt_size, args,
373 MAX_TRACE_PRINTK_VARARGS, &data);
374 if (ret < 0)
375 return ret;
376
377 ret = bstr_printf(data.buf, MAX_BPRINTF_BUF, fmt, data.bin_args);
378
379 trace_bpf_trace_printk(data.buf);
380
381 bpf_bprintf_cleanup(&data);
382
383 return ret;
384 }
385
386 static const struct bpf_func_proto bpf_trace_printk_proto = {
387 .func = bpf_trace_printk,
388 .gpl_only = true,
389 .ret_type = RET_INTEGER,
390 .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY,
391 .arg2_type = ARG_CONST_SIZE,
392 };
393
__set_printk_clr_event(struct work_struct * work)394 static void __set_printk_clr_event(struct work_struct *work)
395 {
396 /*
397 * This program might be calling bpf_trace_printk,
398 * so enable the associated bpf_trace/bpf_trace_printk event.
399 * Repeat this each time as it is possible a user has
400 * disabled bpf_trace_printk events. By loading a program
401 * calling bpf_trace_printk() however the user has expressed
402 * the intent to see such events.
403 */
404 if (trace_set_clr_event("bpf_trace", "bpf_trace_printk", 1))
405 pr_warn_ratelimited("could not enable bpf_trace_printk events");
406 }
407 static DECLARE_WORK(set_printk_work, __set_printk_clr_event);
408
bpf_get_trace_printk_proto(void)409 const struct bpf_func_proto *bpf_get_trace_printk_proto(void)
410 {
411 schedule_work(&set_printk_work);
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 schedule_work(&set_printk_work);
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 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
bpf_get_perf_event_read_value_proto(void)609 const struct bpf_func_proto *bpf_get_perf_event_read_value_proto(void)
610 {
611 return &bpf_perf_event_read_value_proto;
612 }
613
614 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)615 __bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map,
616 u64 flags, struct perf_raw_record *raw,
617 struct perf_sample_data *sd)
618 {
619 struct bpf_array *array = container_of(map, struct bpf_array, map);
620 unsigned int cpu = smp_processor_id();
621 u64 index = flags & BPF_F_INDEX_MASK;
622 struct bpf_event_entry *ee;
623 struct perf_event *event;
624
625 if (index == BPF_F_CURRENT_CPU)
626 index = cpu;
627 if (unlikely(index >= array->map.max_entries))
628 return -E2BIG;
629
630 ee = READ_ONCE(array->ptrs[index]);
631 if (!ee)
632 return -ENOENT;
633
634 event = ee->event;
635 if (unlikely(event->attr.type != PERF_TYPE_SOFTWARE ||
636 event->attr.config != PERF_COUNT_SW_BPF_OUTPUT))
637 return -EINVAL;
638
639 if (unlikely(event->oncpu != cpu))
640 return -EOPNOTSUPP;
641
642 perf_sample_save_raw_data(sd, event, raw);
643
644 return perf_event_output(event, sd, regs);
645 }
646
647 /*
648 * Support executing tracepoints in normal, irq, and nmi context that each call
649 * bpf_perf_event_output
650 */
651 struct bpf_trace_sample_data {
652 struct perf_sample_data sds[3];
653 };
654
655 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_trace_sds);
656 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)657 BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map,
658 u64, flags, void *, data, u64, size)
659 {
660 struct bpf_trace_sample_data *sds;
661 struct perf_raw_record raw = {
662 .frag = {
663 .size = size,
664 .data = data,
665 },
666 };
667 struct perf_sample_data *sd;
668 int nest_level, err;
669
670 preempt_disable();
671 sds = this_cpu_ptr(&bpf_trace_sds);
672 nest_level = this_cpu_inc_return(bpf_trace_nest_level);
673
674 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(sds->sds))) {
675 err = -EBUSY;
676 goto out;
677 }
678
679 sd = &sds->sds[nest_level - 1];
680
681 if (unlikely(flags & ~(BPF_F_INDEX_MASK))) {
682 err = -EINVAL;
683 goto out;
684 }
685
686 perf_sample_data_init(sd, 0, 0);
687
688 err = __bpf_perf_event_output(regs, map, flags, &raw, sd);
689 out:
690 this_cpu_dec(bpf_trace_nest_level);
691 preempt_enable();
692 return err;
693 }
694
695 static const struct bpf_func_proto bpf_perf_event_output_proto = {
696 .func = bpf_perf_event_output,
697 .gpl_only = true,
698 .ret_type = RET_INTEGER,
699 .arg1_type = ARG_PTR_TO_CTX,
700 .arg2_type = ARG_CONST_MAP_PTR,
701 .arg3_type = ARG_ANYTHING,
702 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY,
703 .arg5_type = ARG_CONST_SIZE_OR_ZERO,
704 };
705
706 static DEFINE_PER_CPU(int, bpf_event_output_nest_level);
707 struct bpf_nested_pt_regs {
708 struct pt_regs regs[3];
709 };
710 static DEFINE_PER_CPU(struct bpf_nested_pt_regs, bpf_pt_regs);
711 static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_misc_sds);
712
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)713 u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
714 void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy)
715 {
716 struct perf_raw_frag frag = {
717 .copy = ctx_copy,
718 .size = ctx_size,
719 .data = ctx,
720 };
721 struct perf_raw_record raw = {
722 .frag = {
723 {
724 .next = ctx_size ? &frag : NULL,
725 },
726 .size = meta_size,
727 .data = meta,
728 },
729 };
730 struct perf_sample_data *sd;
731 struct pt_regs *regs;
732 int nest_level;
733 u64 ret;
734
735 preempt_disable();
736 nest_level = this_cpu_inc_return(bpf_event_output_nest_level);
737
738 if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(bpf_misc_sds.sds))) {
739 ret = -EBUSY;
740 goto out;
741 }
742 sd = this_cpu_ptr(&bpf_misc_sds.sds[nest_level - 1]);
743 regs = this_cpu_ptr(&bpf_pt_regs.regs[nest_level - 1]);
744
745 perf_fetch_caller_regs(regs);
746 perf_sample_data_init(sd, 0, 0);
747
748 ret = __bpf_perf_event_output(regs, map, flags, &raw, sd);
749 out:
750 this_cpu_dec(bpf_event_output_nest_level);
751 preempt_enable();
752 return ret;
753 }
754
BPF_CALL_0(bpf_get_current_task)755 BPF_CALL_0(bpf_get_current_task)
756 {
757 return (long) current;
758 }
759
760 const struct bpf_func_proto bpf_get_current_task_proto = {
761 .func = bpf_get_current_task,
762 .gpl_only = true,
763 .ret_type = RET_INTEGER,
764 };
765
BPF_CALL_0(bpf_get_current_task_btf)766 BPF_CALL_0(bpf_get_current_task_btf)
767 {
768 return (unsigned long) current;
769 }
770
771 const struct bpf_func_proto bpf_get_current_task_btf_proto = {
772 .func = bpf_get_current_task_btf,
773 .gpl_only = true,
774 .ret_type = RET_PTR_TO_BTF_ID_TRUSTED,
775 .ret_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK],
776 };
777
BPF_CALL_1(bpf_task_pt_regs,struct task_struct *,task)778 BPF_CALL_1(bpf_task_pt_regs, struct task_struct *, task)
779 {
780 return (unsigned long) task_pt_regs(task);
781 }
782
783 BTF_ID_LIST_SINGLE(bpf_task_pt_regs_ids, struct, pt_regs)
784
785 const struct bpf_func_proto bpf_task_pt_regs_proto = {
786 .func = bpf_task_pt_regs,
787 .gpl_only = true,
788 .arg1_type = ARG_PTR_TO_BTF_ID,
789 .arg1_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK],
790 .ret_type = RET_PTR_TO_BTF_ID,
791 .ret_btf_id = &bpf_task_pt_regs_ids[0],
792 };
793
794 struct send_signal_irq_work {
795 struct irq_work irq_work;
796 struct task_struct *task;
797 u32 sig;
798 enum pid_type type;
799 bool has_siginfo;
800 struct kernel_siginfo info;
801 };
802
803 static DEFINE_PER_CPU(struct send_signal_irq_work, send_signal_work);
804
do_bpf_send_signal(struct irq_work * entry)805 static void do_bpf_send_signal(struct irq_work *entry)
806 {
807 struct send_signal_irq_work *work;
808 struct kernel_siginfo *siginfo;
809
810 work = container_of(entry, struct send_signal_irq_work, irq_work);
811 siginfo = work->has_siginfo ? &work->info : SEND_SIG_PRIV;
812
813 group_send_sig_info(work->sig, siginfo, work->task, work->type);
814 put_task_struct(work->task);
815 }
816
bpf_send_signal_common(u32 sig,enum pid_type type,struct task_struct * task,u64 value)817 static int bpf_send_signal_common(u32 sig, enum pid_type type, struct task_struct *task, u64 value)
818 {
819 struct send_signal_irq_work *work = NULL;
820 struct kernel_siginfo info;
821 struct kernel_siginfo *siginfo;
822
823 if (!task) {
824 task = current;
825 siginfo = SEND_SIG_PRIV;
826 } else {
827 clear_siginfo(&info);
828 info.si_signo = sig;
829 info.si_errno = 0;
830 info.si_code = SI_KERNEL;
831 info.si_pid = 0;
832 info.si_uid = 0;
833 info.si_value.sival_ptr = (void __user __force *)(unsigned long)value;
834 siginfo = &info;
835 }
836
837 /* Similar to bpf_probe_write_user, task needs to be
838 * in a sound condition and kernel memory access be
839 * permitted in order to send signal to the current
840 * task.
841 */
842 if (unlikely(task->flags & (PF_KTHREAD | PF_EXITING)))
843 return -EPERM;
844 if (unlikely(!nmi_uaccess_okay()))
845 return -EPERM;
846 /* Task should not be pid=1 to avoid kernel panic. */
847 if (unlikely(is_global_init(task)))
848 return -EPERM;
849
850 if (preempt_count() != 0 || irqs_disabled()) {
851 /* Do an early check on signal validity. Otherwise,
852 * the error is lost in deferred irq_work.
853 */
854 if (unlikely(!valid_signal(sig)))
855 return -EINVAL;
856
857 work = this_cpu_ptr(&send_signal_work);
858 if (irq_work_is_busy(&work->irq_work))
859 return -EBUSY;
860
861 /* Add the current task, which is the target of sending signal,
862 * to the irq_work. The current task may change when queued
863 * irq works get executed.
864 */
865 work->task = get_task_struct(task);
866 work->has_siginfo = siginfo == &info;
867 if (work->has_siginfo)
868 copy_siginfo(&work->info, &info);
869 work->sig = sig;
870 work->type = type;
871 irq_work_queue(&work->irq_work);
872 return 0;
873 }
874
875 return group_send_sig_info(sig, siginfo, task, type);
876 }
877
BPF_CALL_1(bpf_send_signal,u32,sig)878 BPF_CALL_1(bpf_send_signal, u32, sig)
879 {
880 return bpf_send_signal_common(sig, PIDTYPE_TGID, NULL, 0);
881 }
882
883 const struct bpf_func_proto bpf_send_signal_proto = {
884 .func = bpf_send_signal,
885 .gpl_only = false,
886 .ret_type = RET_INTEGER,
887 .arg1_type = ARG_ANYTHING,
888 };
889
BPF_CALL_1(bpf_send_signal_thread,u32,sig)890 BPF_CALL_1(bpf_send_signal_thread, u32, sig)
891 {
892 return bpf_send_signal_common(sig, PIDTYPE_PID, NULL, 0);
893 }
894
895 const struct bpf_func_proto bpf_send_signal_thread_proto = {
896 .func = bpf_send_signal_thread,
897 .gpl_only = false,
898 .ret_type = RET_INTEGER,
899 .arg1_type = ARG_ANYTHING,
900 };
901
BPF_CALL_3(bpf_d_path,const struct path *,path,char *,buf,u32,sz)902 BPF_CALL_3(bpf_d_path, const struct path *, path, char *, buf, u32, sz)
903 {
904 struct path copy;
905 long len;
906 char *p;
907
908 if (!sz)
909 return 0;
910
911 /*
912 * The path pointer is verified as trusted and safe to use,
913 * but let's double check it's valid anyway to workaround
914 * potentially broken verifier.
915 */
916 len = copy_from_kernel_nofault(©, path, sizeof(*path));
917 if (len < 0)
918 return len;
919
920 p = d_path(©, buf, sz);
921 if (IS_ERR(p)) {
922 len = PTR_ERR(p);
923 } else {
924 len = buf + sz - p;
925 memmove(buf, p, len);
926 }
927
928 return len;
929 }
930
931 BTF_SET_START(btf_allowlist_d_path)
932 #ifdef CONFIG_SECURITY
BTF_ID(func,security_file_permission)933 BTF_ID(func, security_file_permission)
934 BTF_ID(func, security_inode_getattr)
935 BTF_ID(func, security_file_open)
936 #endif
937 #ifdef CONFIG_SECURITY_PATH
938 BTF_ID(func, security_path_truncate)
939 #endif
940 BTF_ID(func, vfs_truncate)
941 BTF_ID(func, vfs_fallocate)
942 BTF_ID(func, dentry_open)
943 BTF_ID(func, vfs_getattr)
944 BTF_ID(func, filp_close)
945 BTF_SET_END(btf_allowlist_d_path)
946
947 static bool bpf_d_path_allowed(const struct bpf_prog *prog)
948 {
949 if (prog->type == BPF_PROG_TYPE_TRACING &&
950 prog->expected_attach_type == BPF_TRACE_ITER)
951 return true;
952
953 if (prog->type == BPF_PROG_TYPE_LSM)
954 return bpf_lsm_is_sleepable_hook(prog->aux->attach_btf_id);
955
956 return btf_id_set_contains(&btf_allowlist_d_path,
957 prog->aux->attach_btf_id);
958 }
959
960 BTF_ID_LIST_SINGLE(bpf_d_path_btf_ids, struct, path)
961
962 static const struct bpf_func_proto bpf_d_path_proto = {
963 .func = bpf_d_path,
964 .gpl_only = false,
965 .ret_type = RET_INTEGER,
966 .arg1_type = ARG_PTR_TO_BTF_ID,
967 .arg1_btf_id = &bpf_d_path_btf_ids[0],
968 .arg2_type = ARG_PTR_TO_MEM | MEM_WRITE,
969 .arg3_type = ARG_CONST_SIZE_OR_ZERO,
970 .allowed = bpf_d_path_allowed,
971 };
972
973 #define BTF_F_ALL (BTF_F_COMPACT | BTF_F_NONAME | \
974 BTF_F_PTR_RAW | BTF_F_ZERO)
975
bpf_btf_printf_prepare(struct btf_ptr * ptr,u32 btf_ptr_size,u64 flags,const struct btf ** btf,s32 * btf_id)976 static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size,
977 u64 flags, const struct btf **btf,
978 s32 *btf_id)
979 {
980 const struct btf_type *t;
981
982 if (unlikely(flags & ~(BTF_F_ALL)))
983 return -EINVAL;
984
985 if (btf_ptr_size != sizeof(struct btf_ptr))
986 return -EINVAL;
987
988 *btf = bpf_get_btf_vmlinux();
989
990 if (IS_ERR_OR_NULL(*btf))
991 return IS_ERR(*btf) ? PTR_ERR(*btf) : -EINVAL;
992
993 if (ptr->type_id > 0)
994 *btf_id = ptr->type_id;
995 else
996 return -EINVAL;
997
998 if (*btf_id > 0)
999 t = btf_type_by_id(*btf, *btf_id);
1000 if (*btf_id <= 0 || !t)
1001 return -ENOENT;
1002
1003 return 0;
1004 }
1005
BPF_CALL_5(bpf_snprintf_btf,char *,str,u32,str_size,struct btf_ptr *,ptr,u32,btf_ptr_size,u64,flags)1006 BPF_CALL_5(bpf_snprintf_btf, char *, str, u32, str_size, struct btf_ptr *, ptr,
1007 u32, btf_ptr_size, u64, flags)
1008 {
1009 const struct btf *btf;
1010 s32 btf_id;
1011 int ret;
1012
1013 ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id);
1014 if (ret)
1015 return ret;
1016
1017 return btf_type_snprintf_show(btf, btf_id, ptr->ptr, str, str_size,
1018 flags);
1019 }
1020
1021 const struct bpf_func_proto bpf_snprintf_btf_proto = {
1022 .func = bpf_snprintf_btf,
1023 .gpl_only = false,
1024 .ret_type = RET_INTEGER,
1025 .arg1_type = ARG_PTR_TO_MEM | MEM_WRITE,
1026 .arg2_type = ARG_CONST_SIZE,
1027 .arg3_type = ARG_PTR_TO_MEM | MEM_RDONLY,
1028 .arg4_type = ARG_CONST_SIZE,
1029 .arg5_type = ARG_ANYTHING,
1030 };
1031
BPF_CALL_1(bpf_get_func_ip_tracing,void *,ctx)1032 BPF_CALL_1(bpf_get_func_ip_tracing, void *, ctx)
1033 {
1034 /* This helper call is inlined by verifier. */
1035 return ((u64 *)ctx)[-2];
1036 }
1037
1038 static const struct bpf_func_proto bpf_get_func_ip_proto_tracing = {
1039 .func = bpf_get_func_ip_tracing,
1040 .gpl_only = true,
1041 .ret_type = RET_INTEGER,
1042 .arg1_type = ARG_PTR_TO_CTX,
1043 };
1044
get_entry_ip(unsigned long fentry_ip)1045 static inline unsigned long get_entry_ip(unsigned long fentry_ip)
1046 {
1047 #ifdef CONFIG_X86_KERNEL_IBT
1048 if (is_endbr((void *)(fentry_ip - ENDBR_INSN_SIZE)))
1049 fentry_ip -= ENDBR_INSN_SIZE;
1050 #endif
1051 return fentry_ip;
1052 }
1053
BPF_CALL_1(bpf_get_func_ip_kprobe,struct pt_regs *,regs)1054 BPF_CALL_1(bpf_get_func_ip_kprobe, struct pt_regs *, regs)
1055 {
1056 struct bpf_trace_run_ctx *run_ctx __maybe_unused;
1057 struct kprobe *kp;
1058
1059 #ifdef CONFIG_UPROBES
1060 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx);
1061 if (run_ctx->is_uprobe)
1062 return ((struct uprobe_dispatch_data *)current->utask->vaddr)->bp_addr;
1063 #endif
1064
1065 kp = kprobe_running();
1066
1067 if (!kp || !(kp->flags & KPROBE_FLAG_ON_FUNC_ENTRY))
1068 return 0;
1069
1070 return get_entry_ip((uintptr_t)kp->addr);
1071 }
1072
1073 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe = {
1074 .func = bpf_get_func_ip_kprobe,
1075 .gpl_only = true,
1076 .ret_type = RET_INTEGER,
1077 .arg1_type = ARG_PTR_TO_CTX,
1078 };
1079
BPF_CALL_1(bpf_get_func_ip_kprobe_multi,struct pt_regs *,regs)1080 BPF_CALL_1(bpf_get_func_ip_kprobe_multi, struct pt_regs *, regs)
1081 {
1082 return bpf_kprobe_multi_entry_ip(current->bpf_ctx);
1083 }
1084
1085 static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe_multi = {
1086 .func = bpf_get_func_ip_kprobe_multi,
1087 .gpl_only = false,
1088 .ret_type = RET_INTEGER,
1089 .arg1_type = ARG_PTR_TO_CTX,
1090 };
1091
BPF_CALL_1(bpf_get_attach_cookie_kprobe_multi,struct pt_regs *,regs)1092 BPF_CALL_1(bpf_get_attach_cookie_kprobe_multi, struct pt_regs *, regs)
1093 {
1094 return bpf_kprobe_multi_cookie(current->bpf_ctx);
1095 }
1096
1097 static const struct bpf_func_proto bpf_get_attach_cookie_proto_kmulti = {
1098 .func = bpf_get_attach_cookie_kprobe_multi,
1099 .gpl_only = false,
1100 .ret_type = RET_INTEGER,
1101 .arg1_type = ARG_PTR_TO_CTX,
1102 };
1103
BPF_CALL_1(bpf_get_func_ip_uprobe_multi,struct pt_regs *,regs)1104 BPF_CALL_1(bpf_get_func_ip_uprobe_multi, struct pt_regs *, regs)
1105 {
1106 return bpf_uprobe_multi_entry_ip(current->bpf_ctx);
1107 }
1108
1109 static const struct bpf_func_proto bpf_get_func_ip_proto_uprobe_multi = {
1110 .func = bpf_get_func_ip_uprobe_multi,
1111 .gpl_only = false,
1112 .ret_type = RET_INTEGER,
1113 .arg1_type = ARG_PTR_TO_CTX,
1114 };
1115
BPF_CALL_1(bpf_get_attach_cookie_uprobe_multi,struct pt_regs *,regs)1116 BPF_CALL_1(bpf_get_attach_cookie_uprobe_multi, struct pt_regs *, regs)
1117 {
1118 return bpf_uprobe_multi_cookie(current->bpf_ctx);
1119 }
1120
1121 static const struct bpf_func_proto bpf_get_attach_cookie_proto_umulti = {
1122 .func = bpf_get_attach_cookie_uprobe_multi,
1123 .gpl_only = false,
1124 .ret_type = RET_INTEGER,
1125 .arg1_type = ARG_PTR_TO_CTX,
1126 };
1127
BPF_CALL_1(bpf_get_attach_cookie_trace,void *,ctx)1128 BPF_CALL_1(bpf_get_attach_cookie_trace, void *, ctx)
1129 {
1130 struct bpf_trace_run_ctx *run_ctx;
1131
1132 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx);
1133 return run_ctx->bpf_cookie;
1134 }
1135
1136 static const struct bpf_func_proto bpf_get_attach_cookie_proto_trace = {
1137 .func = bpf_get_attach_cookie_trace,
1138 .gpl_only = false,
1139 .ret_type = RET_INTEGER,
1140 .arg1_type = ARG_PTR_TO_CTX,
1141 };
1142
BPF_CALL_1(bpf_get_attach_cookie_pe,struct bpf_perf_event_data_kern *,ctx)1143 BPF_CALL_1(bpf_get_attach_cookie_pe, struct bpf_perf_event_data_kern *, ctx)
1144 {
1145 return ctx->event->bpf_cookie;
1146 }
1147
1148 static const struct bpf_func_proto bpf_get_attach_cookie_proto_pe = {
1149 .func = bpf_get_attach_cookie_pe,
1150 .gpl_only = false,
1151 .ret_type = RET_INTEGER,
1152 .arg1_type = ARG_PTR_TO_CTX,
1153 };
1154
BPF_CALL_1(bpf_get_attach_cookie_tracing,void *,ctx)1155 BPF_CALL_1(bpf_get_attach_cookie_tracing, void *, ctx)
1156 {
1157 struct bpf_trace_run_ctx *run_ctx;
1158
1159 run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx);
1160 return run_ctx->bpf_cookie;
1161 }
1162
1163 static const struct bpf_func_proto bpf_get_attach_cookie_proto_tracing = {
1164 .func = bpf_get_attach_cookie_tracing,
1165 .gpl_only = false,
1166 .ret_type = RET_INTEGER,
1167 .arg1_type = ARG_PTR_TO_CTX,
1168 };
1169
BPF_CALL_3(bpf_get_branch_snapshot,void *,buf,u32,size,u64,flags)1170 BPF_CALL_3(bpf_get_branch_snapshot, void *, buf, u32, size, u64, flags)
1171 {
1172 static const u32 br_entry_size = sizeof(struct perf_branch_entry);
1173 u32 entry_cnt = size / br_entry_size;
1174
1175 entry_cnt = static_call(perf_snapshot_branch_stack)(buf, entry_cnt);
1176
1177 if (unlikely(flags))
1178 return -EINVAL;
1179
1180 if (!entry_cnt)
1181 return -ENOENT;
1182
1183 return entry_cnt * br_entry_size;
1184 }
1185
1186 const struct bpf_func_proto bpf_get_branch_snapshot_proto = {
1187 .func = bpf_get_branch_snapshot,
1188 .gpl_only = true,
1189 .ret_type = RET_INTEGER,
1190 .arg1_type = ARG_PTR_TO_UNINIT_MEM,
1191 .arg2_type = ARG_CONST_SIZE_OR_ZERO,
1192 };
1193
BPF_CALL_3(get_func_arg,void *,ctx,u32,n,u64 *,value)1194 BPF_CALL_3(get_func_arg, void *, ctx, u32, n, u64 *, value)
1195 {
1196 /* This helper call is inlined by verifier. */
1197 u64 nr_args = ((u64 *)ctx)[-1] & 0xFF;
1198
1199 if ((u64) n >= nr_args)
1200 return -EINVAL;
1201 *value = ((u64 *)ctx)[n];
1202 return 0;
1203 }
1204
1205 static const struct bpf_func_proto bpf_get_func_arg_proto = {
1206 .func = get_func_arg,
1207 .ret_type = RET_INTEGER,
1208 .arg1_type = ARG_PTR_TO_CTX,
1209 .arg2_type = ARG_ANYTHING,
1210 .arg3_type = ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED,
1211 .arg3_size = sizeof(u64),
1212 };
1213
BPF_CALL_2(get_func_ret,void *,ctx,u64 *,value)1214 BPF_CALL_2(get_func_ret, void *, ctx, u64 *, value)
1215 {
1216 /* This helper call is inlined by verifier. */
1217 u64 nr_args = ((u64 *)ctx)[-1] & 0xFF;
1218
1219 *value = ((u64 *)ctx)[nr_args];
1220 return 0;
1221 }
1222
1223 static const struct bpf_func_proto bpf_get_func_ret_proto = {
1224 .func = get_func_ret,
1225 .ret_type = RET_INTEGER,
1226 .arg1_type = ARG_PTR_TO_CTX,
1227 .arg2_type = ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED,
1228 .arg2_size = sizeof(u64),
1229 };
1230
BPF_CALL_1(get_func_arg_cnt,void *,ctx)1231 BPF_CALL_1(get_func_arg_cnt, void *, ctx)
1232 {
1233 /* This helper call is inlined by verifier. */
1234 return ((u64 *)ctx)[-1] & 0xFF;
1235 }
1236
1237 static const struct bpf_func_proto bpf_get_func_arg_cnt_proto = {
1238 .func = get_func_arg_cnt,
1239 .ret_type = RET_INTEGER,
1240 .arg1_type = ARG_PTR_TO_CTX,
1241 };
1242
1243 static const struct bpf_func_proto *
bpf_tracing_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1244 bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1245 {
1246 const struct bpf_func_proto *func_proto;
1247
1248 switch (func_id) {
1249 case BPF_FUNC_get_smp_processor_id:
1250 return &bpf_get_smp_processor_id_proto;
1251 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
1252 case BPF_FUNC_probe_read:
1253 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
1254 NULL : &bpf_probe_read_compat_proto;
1255 case BPF_FUNC_probe_read_str:
1256 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
1257 NULL : &bpf_probe_read_compat_str_proto;
1258 #endif
1259 case BPF_FUNC_get_func_ip:
1260 return &bpf_get_func_ip_proto_tracing;
1261 default:
1262 break;
1263 }
1264
1265 func_proto = bpf_base_func_proto(func_id, prog);
1266 if (func_proto)
1267 return func_proto;
1268
1269 if (!bpf_token_capable(prog->aux->token, CAP_SYS_ADMIN))
1270 return NULL;
1271
1272 switch (func_id) {
1273 case BPF_FUNC_probe_write_user:
1274 return security_locked_down(LOCKDOWN_BPF_WRITE_USER) < 0 ?
1275 NULL : &bpf_probe_write_user_proto;
1276 default:
1277 return NULL;
1278 }
1279 }
1280
is_kprobe_multi(const struct bpf_prog * prog)1281 static bool is_kprobe_multi(const struct bpf_prog *prog)
1282 {
1283 return prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI ||
1284 prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION;
1285 }
1286
is_kprobe_session(const struct bpf_prog * prog)1287 static inline bool is_kprobe_session(const struct bpf_prog *prog)
1288 {
1289 return prog->type == BPF_PROG_TYPE_KPROBE &&
1290 prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION;
1291 }
1292
is_uprobe_multi(const struct bpf_prog * prog)1293 static inline bool is_uprobe_multi(const struct bpf_prog *prog)
1294 {
1295 return prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI ||
1296 prog->expected_attach_type == BPF_TRACE_UPROBE_SESSION;
1297 }
1298
is_uprobe_session(const struct bpf_prog * prog)1299 static inline bool is_uprobe_session(const struct bpf_prog *prog)
1300 {
1301 return prog->type == BPF_PROG_TYPE_KPROBE &&
1302 prog->expected_attach_type == BPF_TRACE_UPROBE_SESSION;
1303 }
1304
is_trace_fsession(const struct bpf_prog * prog)1305 static inline bool is_trace_fsession(const struct bpf_prog *prog)
1306 {
1307 return prog->type == BPF_PROG_TYPE_TRACING &&
1308 prog->expected_attach_type == BPF_TRACE_FSESSION;
1309 }
1310
1311 static const struct bpf_func_proto *
kprobe_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1312 kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1313 {
1314 switch (func_id) {
1315 case BPF_FUNC_perf_event_output:
1316 return &bpf_perf_event_output_proto;
1317 case BPF_FUNC_get_stackid:
1318 return &bpf_get_stackid_proto;
1319 case BPF_FUNC_get_stack:
1320 return prog->sleepable ? &bpf_get_stack_sleepable_proto : &bpf_get_stack_proto;
1321 #ifdef CONFIG_BPF_KPROBE_OVERRIDE
1322 case BPF_FUNC_override_return:
1323 return &bpf_override_return_proto;
1324 #endif
1325 case BPF_FUNC_get_func_ip:
1326 if (is_kprobe_multi(prog))
1327 return &bpf_get_func_ip_proto_kprobe_multi;
1328 if (is_uprobe_multi(prog))
1329 return &bpf_get_func_ip_proto_uprobe_multi;
1330 return &bpf_get_func_ip_proto_kprobe;
1331 case BPF_FUNC_get_attach_cookie:
1332 if (is_kprobe_multi(prog))
1333 return &bpf_get_attach_cookie_proto_kmulti;
1334 if (is_uprobe_multi(prog))
1335 return &bpf_get_attach_cookie_proto_umulti;
1336 return &bpf_get_attach_cookie_proto_trace;
1337 default:
1338 return bpf_tracing_func_proto(func_id, prog);
1339 }
1340 }
1341
1342 /* 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)1343 static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
1344 const struct bpf_prog *prog,
1345 struct bpf_insn_access_aux *info)
1346 {
1347 if (off < 0 || off >= sizeof(struct pt_regs))
1348 return false;
1349 if (off % size != 0)
1350 return false;
1351 /*
1352 * Assertion for 32 bit to make sure last 8 byte access
1353 * (BPF_DW) to the last 4 byte member is disallowed.
1354 */
1355 if (off + size > sizeof(struct pt_regs))
1356 return false;
1357
1358 if (type == BPF_WRITE)
1359 prog->aux->kprobe_write_ctx = true;
1360
1361 return true;
1362 }
1363
1364 const struct bpf_verifier_ops kprobe_verifier_ops = {
1365 .get_func_proto = kprobe_prog_func_proto,
1366 .is_valid_access = kprobe_prog_is_valid_access,
1367 };
1368
1369 const struct bpf_prog_ops kprobe_prog_ops = {
1370 };
1371
BPF_CALL_5(bpf_perf_event_output_tp,void *,tp_buff,struct bpf_map *,map,u64,flags,void *,data,u64,size)1372 BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map,
1373 u64, flags, void *, data, u64, size)
1374 {
1375 struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1376
1377 /*
1378 * r1 points to perf tracepoint buffer where first 8 bytes are hidden
1379 * from bpf program and contain a pointer to 'struct pt_regs'. Fetch it
1380 * from there and call the same bpf_perf_event_output() helper inline.
1381 */
1382 return ____bpf_perf_event_output(regs, map, flags, data, size);
1383 }
1384
1385 static const struct bpf_func_proto bpf_perf_event_output_proto_tp = {
1386 .func = bpf_perf_event_output_tp,
1387 .gpl_only = true,
1388 .ret_type = RET_INTEGER,
1389 .arg1_type = ARG_PTR_TO_CTX,
1390 .arg2_type = ARG_CONST_MAP_PTR,
1391 .arg3_type = ARG_ANYTHING,
1392 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY,
1393 .arg5_type = ARG_CONST_SIZE_OR_ZERO,
1394 };
1395
BPF_CALL_3(bpf_get_stackid_tp,void *,tp_buff,struct bpf_map *,map,u64,flags)1396 BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map,
1397 u64, flags)
1398 {
1399 struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1400
1401 /*
1402 * Same comment as in bpf_perf_event_output_tp(), only that this time
1403 * the other helper's function body cannot be inlined due to being
1404 * external, thus we need to call raw helper function.
1405 */
1406 return bpf_get_stackid((unsigned long) regs, (unsigned long) map,
1407 flags, 0, 0);
1408 }
1409
1410 static const struct bpf_func_proto bpf_get_stackid_proto_tp = {
1411 .func = bpf_get_stackid_tp,
1412 .gpl_only = true,
1413 .ret_type = RET_INTEGER,
1414 .arg1_type = ARG_PTR_TO_CTX,
1415 .arg2_type = ARG_CONST_MAP_PTR,
1416 .arg3_type = ARG_ANYTHING,
1417 };
1418
BPF_CALL_4(bpf_get_stack_tp,void *,tp_buff,void *,buf,u32,size,u64,flags)1419 BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size,
1420 u64, flags)
1421 {
1422 struct pt_regs *regs = *(struct pt_regs **)tp_buff;
1423
1424 return bpf_get_stack((unsigned long) regs, (unsigned long) buf,
1425 (unsigned long) size, flags, 0);
1426 }
1427
1428 static const struct bpf_func_proto bpf_get_stack_proto_tp = {
1429 .func = bpf_get_stack_tp,
1430 .gpl_only = true,
1431 .ret_type = RET_INTEGER,
1432 .arg1_type = ARG_PTR_TO_CTX,
1433 .arg2_type = ARG_PTR_TO_UNINIT_MEM,
1434 .arg3_type = ARG_CONST_SIZE_OR_ZERO,
1435 .arg4_type = ARG_ANYTHING,
1436 };
1437
1438 static const struct bpf_func_proto *
tp_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1439 tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1440 {
1441 switch (func_id) {
1442 case BPF_FUNC_perf_event_output:
1443 return &bpf_perf_event_output_proto_tp;
1444 case BPF_FUNC_get_stackid:
1445 return &bpf_get_stackid_proto_tp;
1446 case BPF_FUNC_get_stack:
1447 return &bpf_get_stack_proto_tp;
1448 case BPF_FUNC_get_attach_cookie:
1449 return &bpf_get_attach_cookie_proto_trace;
1450 default:
1451 return bpf_tracing_func_proto(func_id, prog);
1452 }
1453 }
1454
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)1455 static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type,
1456 const struct bpf_prog *prog,
1457 struct bpf_insn_access_aux *info)
1458 {
1459 if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE)
1460 return false;
1461 if (type != BPF_READ)
1462 return false;
1463 if (off % size != 0)
1464 return false;
1465
1466 BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(__u64));
1467 return true;
1468 }
1469
1470 const struct bpf_verifier_ops tracepoint_verifier_ops = {
1471 .get_func_proto = tp_prog_func_proto,
1472 .is_valid_access = tp_prog_is_valid_access,
1473 };
1474
1475 const struct bpf_prog_ops tracepoint_prog_ops = {
1476 };
1477
BPF_CALL_3(bpf_perf_prog_read_value,struct bpf_perf_event_data_kern *,ctx,struct bpf_perf_event_value *,buf,u32,size)1478 BPF_CALL_3(bpf_perf_prog_read_value, struct bpf_perf_event_data_kern *, ctx,
1479 struct bpf_perf_event_value *, buf, u32, size)
1480 {
1481 int err = -EINVAL;
1482
1483 if (unlikely(size != sizeof(struct bpf_perf_event_value)))
1484 goto clear;
1485 err = perf_event_read_local(ctx->event, &buf->counter, &buf->enabled,
1486 &buf->running);
1487 if (unlikely(err))
1488 goto clear;
1489 return 0;
1490 clear:
1491 memset(buf, 0, size);
1492 return err;
1493 }
1494
1495 static const struct bpf_func_proto bpf_perf_prog_read_value_proto = {
1496 .func = bpf_perf_prog_read_value,
1497 .gpl_only = true,
1498 .ret_type = RET_INTEGER,
1499 .arg1_type = ARG_PTR_TO_CTX,
1500 .arg2_type = ARG_PTR_TO_UNINIT_MEM,
1501 .arg3_type = ARG_CONST_SIZE,
1502 };
1503
BPF_CALL_4(bpf_read_branch_records,struct bpf_perf_event_data_kern *,ctx,void *,buf,u32,size,u64,flags)1504 BPF_CALL_4(bpf_read_branch_records, struct bpf_perf_event_data_kern *, ctx,
1505 void *, buf, u32, size, u64, flags)
1506 {
1507 static const u32 br_entry_size = sizeof(struct perf_branch_entry);
1508 struct perf_branch_stack *br_stack = ctx->data->br_stack;
1509 u32 to_copy;
1510
1511 if (unlikely(flags & ~BPF_F_GET_BRANCH_RECORDS_SIZE))
1512 return -EINVAL;
1513
1514 if (unlikely(!(ctx->data->sample_flags & PERF_SAMPLE_BRANCH_STACK)))
1515 return -ENOENT;
1516
1517 if (unlikely(!br_stack))
1518 return -ENOENT;
1519
1520 if (flags & BPF_F_GET_BRANCH_RECORDS_SIZE)
1521 return br_stack->nr * br_entry_size;
1522
1523 if (!buf || (size % br_entry_size != 0))
1524 return -EINVAL;
1525
1526 to_copy = min_t(u32, br_stack->nr * br_entry_size, size);
1527 memcpy(buf, br_stack->entries, to_copy);
1528
1529 return to_copy;
1530 }
1531
1532 static const struct bpf_func_proto bpf_read_branch_records_proto = {
1533 .func = bpf_read_branch_records,
1534 .gpl_only = true,
1535 .ret_type = RET_INTEGER,
1536 .arg1_type = ARG_PTR_TO_CTX,
1537 .arg2_type = ARG_PTR_TO_MEM_OR_NULL | MEM_WRITE,
1538 .arg3_type = ARG_CONST_SIZE_OR_ZERO,
1539 .arg4_type = ARG_ANYTHING,
1540 };
1541
1542 static const struct bpf_func_proto *
pe_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1543 pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1544 {
1545 switch (func_id) {
1546 case BPF_FUNC_perf_event_output:
1547 return &bpf_perf_event_output_proto_tp;
1548 case BPF_FUNC_get_stackid:
1549 return &bpf_get_stackid_proto_pe;
1550 case BPF_FUNC_get_stack:
1551 return &bpf_get_stack_proto_pe;
1552 case BPF_FUNC_perf_prog_read_value:
1553 return &bpf_perf_prog_read_value_proto;
1554 case BPF_FUNC_read_branch_records:
1555 return &bpf_read_branch_records_proto;
1556 case BPF_FUNC_get_attach_cookie:
1557 return &bpf_get_attach_cookie_proto_pe;
1558 default:
1559 return bpf_tracing_func_proto(func_id, prog);
1560 }
1561 }
1562
1563 /*
1564 * bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp
1565 * to avoid potential recursive reuse issue when/if tracepoints are added
1566 * inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack.
1567 *
1568 * Since raw tracepoints run despite bpf_prog_active, support concurrent usage
1569 * in normal, irq, and nmi context.
1570 */
1571 struct bpf_raw_tp_regs {
1572 struct pt_regs regs[3];
1573 };
1574 static DEFINE_PER_CPU(struct bpf_raw_tp_regs, bpf_raw_tp_regs);
1575 static DEFINE_PER_CPU(int, bpf_raw_tp_nest_level);
get_bpf_raw_tp_regs(void)1576 static struct pt_regs *get_bpf_raw_tp_regs(void)
1577 {
1578 struct bpf_raw_tp_regs *tp_regs = this_cpu_ptr(&bpf_raw_tp_regs);
1579 int nest_level = this_cpu_inc_return(bpf_raw_tp_nest_level);
1580
1581 if (nest_level > ARRAY_SIZE(tp_regs->regs)) {
1582 this_cpu_dec(bpf_raw_tp_nest_level);
1583 return ERR_PTR(-EBUSY);
1584 }
1585
1586 return &tp_regs->regs[nest_level - 1];
1587 }
1588
put_bpf_raw_tp_regs(void)1589 static void put_bpf_raw_tp_regs(void)
1590 {
1591 this_cpu_dec(bpf_raw_tp_nest_level);
1592 }
1593
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)1594 BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args,
1595 struct bpf_map *, map, u64, flags, void *, data, u64, size)
1596 {
1597 struct pt_regs *regs = get_bpf_raw_tp_regs();
1598 int ret;
1599
1600 if (IS_ERR(regs))
1601 return PTR_ERR(regs);
1602
1603 perf_fetch_caller_regs(regs);
1604 ret = ____bpf_perf_event_output(regs, map, flags, data, size);
1605
1606 put_bpf_raw_tp_regs();
1607 return ret;
1608 }
1609
1610 static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = {
1611 .func = bpf_perf_event_output_raw_tp,
1612 .gpl_only = true,
1613 .ret_type = RET_INTEGER,
1614 .arg1_type = ARG_PTR_TO_CTX,
1615 .arg2_type = ARG_CONST_MAP_PTR,
1616 .arg3_type = ARG_ANYTHING,
1617 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY,
1618 .arg5_type = ARG_CONST_SIZE_OR_ZERO,
1619 };
1620
1621 extern const struct bpf_func_proto bpf_skb_output_proto;
1622 extern const struct bpf_func_proto bpf_xdp_output_proto;
1623 extern const struct bpf_func_proto bpf_xdp_get_buff_len_trace_proto;
1624
BPF_CALL_3(bpf_get_stackid_raw_tp,struct bpf_raw_tracepoint_args *,args,struct bpf_map *,map,u64,flags)1625 BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args,
1626 struct bpf_map *, map, u64, flags)
1627 {
1628 struct pt_regs *regs = get_bpf_raw_tp_regs();
1629 int ret;
1630
1631 if (IS_ERR(regs))
1632 return PTR_ERR(regs);
1633
1634 perf_fetch_caller_regs(regs);
1635 /* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */
1636 ret = bpf_get_stackid((unsigned long) regs, (unsigned long) map,
1637 flags, 0, 0);
1638 put_bpf_raw_tp_regs();
1639 return ret;
1640 }
1641
1642 static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = {
1643 .func = bpf_get_stackid_raw_tp,
1644 .gpl_only = true,
1645 .ret_type = RET_INTEGER,
1646 .arg1_type = ARG_PTR_TO_CTX,
1647 .arg2_type = ARG_CONST_MAP_PTR,
1648 .arg3_type = ARG_ANYTHING,
1649 };
1650
BPF_CALL_4(bpf_get_stack_raw_tp,struct bpf_raw_tracepoint_args *,args,void *,buf,u32,size,u64,flags)1651 BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args,
1652 void *, buf, u32, size, u64, flags)
1653 {
1654 struct pt_regs *regs = get_bpf_raw_tp_regs();
1655 int ret;
1656
1657 if (IS_ERR(regs))
1658 return PTR_ERR(regs);
1659
1660 perf_fetch_caller_regs(regs);
1661 ret = bpf_get_stack((unsigned long) regs, (unsigned long) buf,
1662 (unsigned long) size, flags, 0);
1663 put_bpf_raw_tp_regs();
1664 return ret;
1665 }
1666
1667 static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = {
1668 .func = bpf_get_stack_raw_tp,
1669 .gpl_only = true,
1670 .ret_type = RET_INTEGER,
1671 .arg1_type = ARG_PTR_TO_CTX,
1672 .arg2_type = ARG_PTR_TO_UNINIT_MEM,
1673 .arg3_type = ARG_CONST_SIZE_OR_ZERO,
1674 .arg4_type = ARG_ANYTHING,
1675 };
1676
1677 static const struct bpf_func_proto *
raw_tp_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1678 raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1679 {
1680 switch (func_id) {
1681 case BPF_FUNC_perf_event_output:
1682 return &bpf_perf_event_output_proto_raw_tp;
1683 case BPF_FUNC_get_stackid:
1684 return &bpf_get_stackid_proto_raw_tp;
1685 case BPF_FUNC_get_stack:
1686 return &bpf_get_stack_proto_raw_tp;
1687 case BPF_FUNC_get_attach_cookie:
1688 return &bpf_get_attach_cookie_proto_tracing;
1689 default:
1690 return bpf_tracing_func_proto(func_id, prog);
1691 }
1692 }
1693
1694 const struct bpf_func_proto *
tracing_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)1695 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1696 {
1697 const struct bpf_func_proto *fn;
1698
1699 switch (func_id) {
1700 #ifdef CONFIG_NET
1701 case BPF_FUNC_skb_output:
1702 return &bpf_skb_output_proto;
1703 case BPF_FUNC_xdp_output:
1704 return &bpf_xdp_output_proto;
1705 case BPF_FUNC_skc_to_tcp6_sock:
1706 return &bpf_skc_to_tcp6_sock_proto;
1707 case BPF_FUNC_skc_to_tcp_sock:
1708 return &bpf_skc_to_tcp_sock_proto;
1709 case BPF_FUNC_skc_to_tcp_timewait_sock:
1710 return &bpf_skc_to_tcp_timewait_sock_proto;
1711 case BPF_FUNC_skc_to_tcp_request_sock:
1712 return &bpf_skc_to_tcp_request_sock_proto;
1713 case BPF_FUNC_skc_to_udp6_sock:
1714 return &bpf_skc_to_udp6_sock_proto;
1715 case BPF_FUNC_skc_to_unix_sock:
1716 return &bpf_skc_to_unix_sock_proto;
1717 case BPF_FUNC_skc_to_mptcp_sock:
1718 return &bpf_skc_to_mptcp_sock_proto;
1719 case BPF_FUNC_sk_storage_get:
1720 return &bpf_sk_storage_get_tracing_proto;
1721 case BPF_FUNC_sk_storage_delete:
1722 return &bpf_sk_storage_delete_tracing_proto;
1723 case BPF_FUNC_sock_from_file:
1724 return &bpf_sock_from_file_proto;
1725 case BPF_FUNC_get_socket_cookie:
1726 return &bpf_get_socket_ptr_cookie_proto;
1727 case BPF_FUNC_xdp_get_buff_len:
1728 return &bpf_xdp_get_buff_len_trace_proto;
1729 #endif
1730 case BPF_FUNC_seq_printf:
1731 return prog->expected_attach_type == BPF_TRACE_ITER ?
1732 &bpf_seq_printf_proto :
1733 NULL;
1734 case BPF_FUNC_seq_write:
1735 return prog->expected_attach_type == BPF_TRACE_ITER ?
1736 &bpf_seq_write_proto :
1737 NULL;
1738 case BPF_FUNC_seq_printf_btf:
1739 return prog->expected_attach_type == BPF_TRACE_ITER ?
1740 &bpf_seq_printf_btf_proto :
1741 NULL;
1742 case BPF_FUNC_d_path:
1743 return &bpf_d_path_proto;
1744 case BPF_FUNC_get_func_arg:
1745 if (bpf_prog_has_trampoline(prog) ||
1746 prog->expected_attach_type == BPF_TRACE_RAW_TP)
1747 return &bpf_get_func_arg_proto;
1748 return NULL;
1749 case BPF_FUNC_get_func_ret:
1750 return bpf_prog_has_trampoline(prog) ? &bpf_get_func_ret_proto : NULL;
1751 case BPF_FUNC_get_func_arg_cnt:
1752 if (bpf_prog_has_trampoline(prog) ||
1753 prog->expected_attach_type == BPF_TRACE_RAW_TP)
1754 return &bpf_get_func_arg_cnt_proto;
1755 return NULL;
1756 case BPF_FUNC_get_attach_cookie:
1757 if (prog->type == BPF_PROG_TYPE_TRACING &&
1758 prog->expected_attach_type == BPF_TRACE_RAW_TP)
1759 return &bpf_get_attach_cookie_proto_tracing;
1760 return bpf_prog_has_trampoline(prog) ? &bpf_get_attach_cookie_proto_tracing : NULL;
1761 default:
1762 fn = raw_tp_prog_func_proto(func_id, prog);
1763 if (!fn && prog->expected_attach_type == BPF_TRACE_ITER)
1764 fn = bpf_iter_get_func_proto(func_id, prog);
1765 return fn;
1766 }
1767 }
1768
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)1769 static bool raw_tp_prog_is_valid_access(int off, int size,
1770 enum bpf_access_type type,
1771 const struct bpf_prog *prog,
1772 struct bpf_insn_access_aux *info)
1773 {
1774 return bpf_tracing_ctx_access(off, size, type);
1775 }
1776
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)1777 static bool tracing_prog_is_valid_access(int off, int size,
1778 enum bpf_access_type type,
1779 const struct bpf_prog *prog,
1780 struct bpf_insn_access_aux *info)
1781 {
1782 return bpf_tracing_btf_ctx_access(off, size, type, prog, info);
1783 }
1784
bpf_prog_test_run_tracing(struct bpf_prog * prog,const union bpf_attr * kattr,union bpf_attr __user * uattr)1785 int __weak bpf_prog_test_run_tracing(struct bpf_prog *prog,
1786 const union bpf_attr *kattr,
1787 union bpf_attr __user *uattr)
1788 {
1789 return -ENOTSUPP;
1790 }
1791
1792 const struct bpf_verifier_ops raw_tracepoint_verifier_ops = {
1793 .get_func_proto = raw_tp_prog_func_proto,
1794 .is_valid_access = raw_tp_prog_is_valid_access,
1795 };
1796
1797 const struct bpf_prog_ops raw_tracepoint_prog_ops = {
1798 #ifdef CONFIG_NET
1799 .test_run = bpf_prog_test_run_raw_tp,
1800 #endif
1801 };
1802
1803 const struct bpf_verifier_ops tracing_verifier_ops = {
1804 .get_func_proto = tracing_prog_func_proto,
1805 .is_valid_access = tracing_prog_is_valid_access,
1806 };
1807
1808 const struct bpf_prog_ops tracing_prog_ops = {
1809 .test_run = bpf_prog_test_run_tracing,
1810 };
1811
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)1812 static bool raw_tp_writable_prog_is_valid_access(int off, int size,
1813 enum bpf_access_type type,
1814 const struct bpf_prog *prog,
1815 struct bpf_insn_access_aux *info)
1816 {
1817 if (off == 0) {
1818 if (size != sizeof(u64) || type != BPF_READ)
1819 return false;
1820 info->reg_type = PTR_TO_TP_BUFFER;
1821 }
1822 return raw_tp_prog_is_valid_access(off, size, type, prog, info);
1823 }
1824
1825 const struct bpf_verifier_ops raw_tracepoint_writable_verifier_ops = {
1826 .get_func_proto = raw_tp_prog_func_proto,
1827 .is_valid_access = raw_tp_writable_prog_is_valid_access,
1828 };
1829
1830 const struct bpf_prog_ops raw_tracepoint_writable_prog_ops = {
1831 };
1832
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)1833 static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
1834 const struct bpf_prog *prog,
1835 struct bpf_insn_access_aux *info)
1836 {
1837 const int size_u64 = sizeof(u64);
1838
1839 if (off < 0 || off >= sizeof(struct bpf_perf_event_data))
1840 return false;
1841 if (type != BPF_READ)
1842 return false;
1843 if (off % size != 0) {
1844 if (sizeof(unsigned long) != 4)
1845 return false;
1846 if (size != 8)
1847 return false;
1848 if (off % size != 4)
1849 return false;
1850 }
1851
1852 switch (off) {
1853 case bpf_ctx_range(struct bpf_perf_event_data, sample_period):
1854 bpf_ctx_record_field_size(info, size_u64);
1855 if (!bpf_ctx_narrow_access_ok(off, size, size_u64))
1856 return false;
1857 break;
1858 case bpf_ctx_range(struct bpf_perf_event_data, addr):
1859 bpf_ctx_record_field_size(info, size_u64);
1860 if (!bpf_ctx_narrow_access_ok(off, size, size_u64))
1861 return false;
1862 break;
1863 default:
1864 if (size != sizeof(long))
1865 return false;
1866 }
1867
1868 return true;
1869 }
1870
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)1871 static u32 pe_prog_convert_ctx_access(enum bpf_access_type type,
1872 const struct bpf_insn *si,
1873 struct bpf_insn *insn_buf,
1874 struct bpf_prog *prog, u32 *target_size)
1875 {
1876 struct bpf_insn *insn = insn_buf;
1877
1878 switch (si->off) {
1879 case offsetof(struct bpf_perf_event_data, sample_period):
1880 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
1881 data), si->dst_reg, si->src_reg,
1882 offsetof(struct bpf_perf_event_data_kern, data));
1883 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg,
1884 bpf_target_off(struct perf_sample_data, period, 8,
1885 target_size));
1886 break;
1887 case offsetof(struct bpf_perf_event_data, addr):
1888 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
1889 data), si->dst_reg, si->src_reg,
1890 offsetof(struct bpf_perf_event_data_kern, data));
1891 *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg,
1892 bpf_target_off(struct perf_sample_data, addr, 8,
1893 target_size));
1894 break;
1895 default:
1896 *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
1897 regs), si->dst_reg, si->src_reg,
1898 offsetof(struct bpf_perf_event_data_kern, regs));
1899 *insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg,
1900 si->off);
1901 break;
1902 }
1903
1904 return insn - insn_buf;
1905 }
1906
1907 const struct bpf_verifier_ops perf_event_verifier_ops = {
1908 .get_func_proto = pe_prog_func_proto,
1909 .is_valid_access = pe_prog_is_valid_access,
1910 .convert_ctx_access = pe_prog_convert_ctx_access,
1911 };
1912
1913 const struct bpf_prog_ops perf_event_prog_ops = {
1914 };
1915
1916 static DEFINE_MUTEX(bpf_event_mutex);
1917
1918 #define BPF_TRACE_MAX_PROGS 64
1919
perf_event_attach_bpf_prog(struct perf_event * event,struct bpf_prog * prog,u64 bpf_cookie)1920 int perf_event_attach_bpf_prog(struct perf_event *event,
1921 struct bpf_prog *prog,
1922 u64 bpf_cookie)
1923 {
1924 struct bpf_prog_array *old_array;
1925 struct bpf_prog_array *new_array;
1926 int ret = -EEXIST;
1927
1928 /*
1929 * Kprobe override only works if they are on the function entry,
1930 * and only if they are on the opt-in list.
1931 */
1932 if (prog->kprobe_override &&
1933 (!trace_kprobe_on_func_entry(event->tp_event) ||
1934 !trace_kprobe_error_injectable(event->tp_event)))
1935 return -EINVAL;
1936
1937 mutex_lock(&bpf_event_mutex);
1938
1939 if (event->prog)
1940 goto unlock;
1941
1942 old_array = bpf_event_rcu_dereference(event->tp_event->prog_array);
1943 if (old_array &&
1944 bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) {
1945 ret = -E2BIG;
1946 goto unlock;
1947 }
1948
1949 ret = bpf_prog_array_copy(old_array, NULL, prog, bpf_cookie, &new_array);
1950 if (ret < 0)
1951 goto unlock;
1952
1953 /* set the new array to event->tp_event and set event->prog */
1954 event->prog = prog;
1955 event->bpf_cookie = bpf_cookie;
1956 rcu_assign_pointer(event->tp_event->prog_array, new_array);
1957 bpf_prog_array_free_sleepable(old_array);
1958
1959 unlock:
1960 mutex_unlock(&bpf_event_mutex);
1961 return ret;
1962 }
1963
perf_event_detach_bpf_prog(struct perf_event * event)1964 void perf_event_detach_bpf_prog(struct perf_event *event)
1965 {
1966 struct bpf_prog_array *old_array;
1967 struct bpf_prog_array *new_array;
1968 struct bpf_prog *prog = NULL;
1969 int ret;
1970
1971 mutex_lock(&bpf_event_mutex);
1972
1973 if (!event->prog)
1974 goto unlock;
1975
1976 old_array = bpf_event_rcu_dereference(event->tp_event->prog_array);
1977 if (!old_array)
1978 goto put;
1979
1980 ret = bpf_prog_array_copy(old_array, event->prog, NULL, 0, &new_array);
1981 if (ret < 0) {
1982 bpf_prog_array_delete_safe(old_array, event->prog);
1983 } else {
1984 rcu_assign_pointer(event->tp_event->prog_array, new_array);
1985 bpf_prog_array_free_sleepable(old_array);
1986 }
1987
1988 put:
1989 prog = event->prog;
1990 event->prog = NULL;
1991
1992 unlock:
1993 mutex_unlock(&bpf_event_mutex);
1994
1995 if (prog) {
1996 /*
1997 * It could be that the bpf_prog is not sleepable (and will be freed
1998 * via normal RCU), but is called from a point that supports sleepable
1999 * programs and uses tasks-trace-RCU.
2000 */
2001 synchronize_rcu_tasks_trace();
2002
2003 bpf_prog_put(prog);
2004 }
2005 }
2006
perf_event_query_prog_array(struct perf_event * event,void __user * info)2007 int perf_event_query_prog_array(struct perf_event *event, void __user *info)
2008 {
2009 struct perf_event_query_bpf __user *uquery = info;
2010 struct perf_event_query_bpf query = {};
2011 struct bpf_prog_array *progs;
2012 u32 *ids, prog_cnt, ids_len;
2013 int ret;
2014
2015 if (!perfmon_capable())
2016 return -EPERM;
2017 if (event->attr.type != PERF_TYPE_TRACEPOINT)
2018 return -EINVAL;
2019 if (copy_from_user(&query, uquery, sizeof(query)))
2020 return -EFAULT;
2021
2022 ids_len = query.ids_len;
2023 if (ids_len > BPF_TRACE_MAX_PROGS)
2024 return -E2BIG;
2025 ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN);
2026 if (!ids)
2027 return -ENOMEM;
2028 /*
2029 * The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which
2030 * is required when user only wants to check for uquery->prog_cnt.
2031 * There is no need to check for it since the case is handled
2032 * gracefully in bpf_prog_array_copy_info.
2033 */
2034
2035 mutex_lock(&bpf_event_mutex);
2036 progs = bpf_event_rcu_dereference(event->tp_event->prog_array);
2037 ret = bpf_prog_array_copy_info(progs, ids, ids_len, &prog_cnt);
2038 mutex_unlock(&bpf_event_mutex);
2039
2040 if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) ||
2041 copy_to_user(uquery->ids, ids, ids_len * sizeof(u32)))
2042 ret = -EFAULT;
2043
2044 kfree(ids);
2045 return ret;
2046 }
2047
2048 extern struct bpf_raw_event_map __start__bpf_raw_tp[];
2049 extern struct bpf_raw_event_map __stop__bpf_raw_tp[];
2050
bpf_get_raw_tracepoint(const char * name)2051 struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name)
2052 {
2053 struct bpf_raw_event_map *btp = __start__bpf_raw_tp;
2054
2055 for (; btp < __stop__bpf_raw_tp; btp++) {
2056 if (!strcmp(btp->tp->name, name))
2057 return btp;
2058 }
2059
2060 return bpf_get_raw_tracepoint_module(name);
2061 }
2062
bpf_put_raw_tracepoint(struct bpf_raw_event_map * btp)2063 void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp)
2064 {
2065 struct module *mod;
2066
2067 guard(rcu)();
2068 mod = __module_address((unsigned long)btp);
2069 module_put(mod);
2070 }
2071
2072 static __always_inline
__bpf_trace_run(struct bpf_raw_tp_link * link,u64 * args)2073 void __bpf_trace_run(struct bpf_raw_tp_link *link, u64 *args)
2074 {
2075 struct bpf_prog *prog = link->link.prog;
2076 struct bpf_run_ctx *old_run_ctx;
2077 struct bpf_trace_run_ctx run_ctx;
2078
2079 rcu_read_lock_dont_migrate();
2080 if (unlikely(!bpf_prog_get_recursion_context(prog))) {
2081 bpf_prog_inc_misses_counter(prog);
2082 goto out;
2083 }
2084
2085 run_ctx.bpf_cookie = link->cookie;
2086 old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx);
2087
2088 (void) bpf_prog_run(prog, args);
2089
2090 bpf_reset_run_ctx(old_run_ctx);
2091 out:
2092 bpf_prog_put_recursion_context(prog);
2093 rcu_read_unlock_migrate();
2094 }
2095
2096 #define UNPACK(...) __VA_ARGS__
2097 #define REPEAT_1(FN, DL, X, ...) FN(X)
2098 #define REPEAT_2(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__)
2099 #define REPEAT_3(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_2(FN, DL, __VA_ARGS__)
2100 #define REPEAT_4(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_3(FN, DL, __VA_ARGS__)
2101 #define REPEAT_5(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_4(FN, DL, __VA_ARGS__)
2102 #define REPEAT_6(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_5(FN, DL, __VA_ARGS__)
2103 #define REPEAT_7(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_6(FN, DL, __VA_ARGS__)
2104 #define REPEAT_8(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_7(FN, DL, __VA_ARGS__)
2105 #define REPEAT_9(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_8(FN, DL, __VA_ARGS__)
2106 #define REPEAT_10(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_9(FN, DL, __VA_ARGS__)
2107 #define REPEAT_11(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_10(FN, DL, __VA_ARGS__)
2108 #define REPEAT_12(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_11(FN, DL, __VA_ARGS__)
2109 #define REPEAT(X, FN, DL, ...) REPEAT_##X(FN, DL, __VA_ARGS__)
2110
2111 #define SARG(X) u64 arg##X
2112 #define COPY(X) args[X] = arg##X
2113
2114 #define __DL_COM (,)
2115 #define __DL_SEM (;)
2116
2117 #define __SEQ_0_11 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11
2118
2119 #define BPF_TRACE_DEFN_x(x) \
2120 void bpf_trace_run##x(struct bpf_raw_tp_link *link, \
2121 REPEAT(x, SARG, __DL_COM, __SEQ_0_11)) \
2122 { \
2123 u64 args[x]; \
2124 REPEAT(x, COPY, __DL_SEM, __SEQ_0_11); \
2125 __bpf_trace_run(link, args); \
2126 } \
2127 EXPORT_SYMBOL_GPL(bpf_trace_run##x)
2128 BPF_TRACE_DEFN_x(1);
2129 BPF_TRACE_DEFN_x(2);
2130 BPF_TRACE_DEFN_x(3);
2131 BPF_TRACE_DEFN_x(4);
2132 BPF_TRACE_DEFN_x(5);
2133 BPF_TRACE_DEFN_x(6);
2134 BPF_TRACE_DEFN_x(7);
2135 BPF_TRACE_DEFN_x(8);
2136 BPF_TRACE_DEFN_x(9);
2137 BPF_TRACE_DEFN_x(10);
2138 BPF_TRACE_DEFN_x(11);
2139 BPF_TRACE_DEFN_x(12);
2140
bpf_probe_register(struct bpf_raw_event_map * btp,struct bpf_raw_tp_link * link)2141 int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_raw_tp_link *link)
2142 {
2143 struct tracepoint *tp = btp->tp;
2144 struct bpf_prog *prog = link->link.prog;
2145
2146 /*
2147 * check that program doesn't access arguments beyond what's
2148 * available in this tracepoint
2149 */
2150 if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64))
2151 return -EINVAL;
2152
2153 if (prog->aux->max_tp_access > btp->writable_size)
2154 return -EINVAL;
2155
2156 return tracepoint_probe_register_may_exist(tp, (void *)btp->bpf_func, link);
2157 }
2158
bpf_probe_unregister(struct bpf_raw_event_map * btp,struct bpf_raw_tp_link * link)2159 int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_raw_tp_link *link)
2160 {
2161 return tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, link);
2162 }
2163
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)2164 int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id,
2165 u32 *fd_type, const char **buf,
2166 u64 *probe_offset, u64 *probe_addr,
2167 unsigned long *missed)
2168 {
2169 bool is_tracepoint, is_syscall_tp;
2170 struct bpf_prog *prog;
2171 int flags, err = 0;
2172
2173 prog = event->prog;
2174 if (!prog)
2175 return -ENOENT;
2176
2177 /* not supporting BPF_PROG_TYPE_PERF_EVENT yet */
2178 if (prog->type == BPF_PROG_TYPE_PERF_EVENT)
2179 return -EOPNOTSUPP;
2180
2181 *prog_id = prog->aux->id;
2182 flags = event->tp_event->flags;
2183 is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT;
2184 is_syscall_tp = is_syscall_trace_event(event->tp_event);
2185
2186 if (is_tracepoint || is_syscall_tp) {
2187 *buf = is_tracepoint ? event->tp_event->tp->name
2188 : event->tp_event->name;
2189 /* We allow NULL pointer for tracepoint */
2190 if (fd_type)
2191 *fd_type = BPF_FD_TYPE_TRACEPOINT;
2192 if (probe_offset)
2193 *probe_offset = 0x0;
2194 if (probe_addr)
2195 *probe_addr = 0x0;
2196 } else {
2197 /* kprobe/uprobe */
2198 err = -EOPNOTSUPP;
2199 #ifdef CONFIG_KPROBE_EVENTS
2200 if (flags & TRACE_EVENT_FL_KPROBE)
2201 err = bpf_get_kprobe_info(event, fd_type, buf,
2202 probe_offset, probe_addr, missed,
2203 event->attr.type == PERF_TYPE_TRACEPOINT);
2204 #endif
2205 #ifdef CONFIG_UPROBE_EVENTS
2206 if (flags & TRACE_EVENT_FL_UPROBE)
2207 err = bpf_get_uprobe_info(event, fd_type, buf,
2208 probe_offset, probe_addr,
2209 event->attr.type == PERF_TYPE_TRACEPOINT);
2210 #endif
2211 }
2212
2213 return err;
2214 }
2215
send_signal_irq_work_init(void)2216 static int __init send_signal_irq_work_init(void)
2217 {
2218 int cpu;
2219 struct send_signal_irq_work *work;
2220
2221 for_each_possible_cpu(cpu) {
2222 work = per_cpu_ptr(&send_signal_work, cpu);
2223 init_irq_work(&work->irq_work, do_bpf_send_signal);
2224 }
2225 return 0;
2226 }
2227
2228 subsys_initcall(send_signal_irq_work_init);
2229
2230 #ifdef CONFIG_MODULES
bpf_event_notify(struct notifier_block * nb,unsigned long op,void * module)2231 static int bpf_event_notify(struct notifier_block *nb, unsigned long op,
2232 void *module)
2233 {
2234 struct bpf_trace_module *btm, *tmp;
2235 struct module *mod = module;
2236 int ret = 0;
2237
2238 if (mod->num_bpf_raw_events == 0 ||
2239 (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING))
2240 goto out;
2241
2242 mutex_lock(&bpf_module_mutex);
2243
2244 switch (op) {
2245 case MODULE_STATE_COMING:
2246 btm = kzalloc_obj(*btm);
2247 if (btm) {
2248 btm->module = module;
2249 list_add(&btm->list, &bpf_trace_modules);
2250 } else {
2251 ret = -ENOMEM;
2252 }
2253 break;
2254 case MODULE_STATE_GOING:
2255 list_for_each_entry_safe(btm, tmp, &bpf_trace_modules, list) {
2256 if (btm->module == module) {
2257 list_del(&btm->list);
2258 kfree(btm);
2259 break;
2260 }
2261 }
2262 break;
2263 }
2264
2265 mutex_unlock(&bpf_module_mutex);
2266
2267 out:
2268 return notifier_from_errno(ret);
2269 }
2270
2271 static struct notifier_block bpf_module_nb = {
2272 .notifier_call = bpf_event_notify,
2273 };
2274
bpf_event_init(void)2275 static int __init bpf_event_init(void)
2276 {
2277 register_module_notifier(&bpf_module_nb);
2278 return 0;
2279 }
2280
2281 fs_initcall(bpf_event_init);
2282 #endif /* CONFIG_MODULES */
2283
2284 struct bpf_session_run_ctx {
2285 struct bpf_run_ctx run_ctx;
2286 bool is_return;
2287 void *data;
2288 };
2289
2290 #ifdef CONFIG_FPROBE
2291 struct bpf_kprobe_multi_link {
2292 struct bpf_link link;
2293 struct fprobe fp;
2294 unsigned long *addrs;
2295 u64 *cookies;
2296 u32 cnt;
2297 u32 mods_cnt;
2298 struct module **mods;
2299 };
2300
2301 struct bpf_kprobe_multi_run_ctx {
2302 struct bpf_session_run_ctx session_ctx;
2303 struct bpf_kprobe_multi_link *link;
2304 unsigned long entry_ip;
2305 };
2306
2307 struct user_syms {
2308 const char **syms;
2309 char *buf;
2310 };
2311
2312 #ifndef CONFIG_HAVE_FTRACE_REGS_HAVING_PT_REGS
2313 static DEFINE_PER_CPU(struct pt_regs, bpf_kprobe_multi_pt_regs);
2314 #define bpf_kprobe_multi_pt_regs_ptr() this_cpu_ptr(&bpf_kprobe_multi_pt_regs)
2315 #else
2316 #define bpf_kprobe_multi_pt_regs_ptr() (NULL)
2317 #endif
2318
ftrace_get_entry_ip(unsigned long fentry_ip)2319 static unsigned long ftrace_get_entry_ip(unsigned long fentry_ip)
2320 {
2321 unsigned long ip = ftrace_get_symaddr(fentry_ip);
2322
2323 return ip ? : fentry_ip;
2324 }
2325
copy_user_syms(struct user_syms * us,unsigned long __user * usyms,u32 cnt)2326 static int copy_user_syms(struct user_syms *us, unsigned long __user *usyms, u32 cnt)
2327 {
2328 unsigned long __user usymbol;
2329 const char **syms = NULL;
2330 char *buf = NULL, *p;
2331 int err = -ENOMEM;
2332 unsigned int i;
2333
2334 syms = kvmalloc_array(cnt, sizeof(*syms), GFP_KERNEL);
2335 if (!syms)
2336 goto error;
2337
2338 buf = kvmalloc_array(cnt, KSYM_NAME_LEN, GFP_KERNEL);
2339 if (!buf)
2340 goto error;
2341
2342 for (p = buf, i = 0; i < cnt; i++) {
2343 if (__get_user(usymbol, usyms + i)) {
2344 err = -EFAULT;
2345 goto error;
2346 }
2347 err = strncpy_from_user(p, (const char __user *) usymbol, KSYM_NAME_LEN);
2348 if (err == KSYM_NAME_LEN)
2349 err = -E2BIG;
2350 if (err < 0)
2351 goto error;
2352 syms[i] = p;
2353 p += err + 1;
2354 }
2355
2356 us->syms = syms;
2357 us->buf = buf;
2358 return 0;
2359
2360 error:
2361 if (err) {
2362 kvfree(syms);
2363 kvfree(buf);
2364 }
2365 return err;
2366 }
2367
kprobe_multi_put_modules(struct module ** mods,u32 cnt)2368 static void kprobe_multi_put_modules(struct module **mods, u32 cnt)
2369 {
2370 u32 i;
2371
2372 for (i = 0; i < cnt; i++)
2373 module_put(mods[i]);
2374 }
2375
free_user_syms(struct user_syms * us)2376 static void free_user_syms(struct user_syms *us)
2377 {
2378 kvfree(us->syms);
2379 kvfree(us->buf);
2380 }
2381
bpf_kprobe_multi_link_release(struct bpf_link * link)2382 static void bpf_kprobe_multi_link_release(struct bpf_link *link)
2383 {
2384 struct bpf_kprobe_multi_link *kmulti_link;
2385
2386 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);
2387 unregister_fprobe(&kmulti_link->fp);
2388 kprobe_multi_put_modules(kmulti_link->mods, kmulti_link->mods_cnt);
2389 }
2390
bpf_kprobe_multi_link_dealloc(struct bpf_link * link)2391 static void bpf_kprobe_multi_link_dealloc(struct bpf_link *link)
2392 {
2393 struct bpf_kprobe_multi_link *kmulti_link;
2394
2395 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);
2396 kvfree(kmulti_link->addrs);
2397 kvfree(kmulti_link->cookies);
2398 kfree(kmulti_link->mods);
2399 kfree(kmulti_link);
2400 }
2401
bpf_kprobe_multi_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)2402 static int bpf_kprobe_multi_link_fill_link_info(const struct bpf_link *link,
2403 struct bpf_link_info *info)
2404 {
2405 u64 __user *ucookies = u64_to_user_ptr(info->kprobe_multi.cookies);
2406 u64 __user *uaddrs = u64_to_user_ptr(info->kprobe_multi.addrs);
2407 struct bpf_kprobe_multi_link *kmulti_link;
2408 u32 ucount = info->kprobe_multi.count;
2409 int err = 0, i;
2410
2411 if (!uaddrs ^ !ucount)
2412 return -EINVAL;
2413 if (ucookies && !ucount)
2414 return -EINVAL;
2415
2416 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);
2417 info->kprobe_multi.count = kmulti_link->cnt;
2418 info->kprobe_multi.flags = kmulti_link->link.flags;
2419 info->kprobe_multi.missed = kmulti_link->fp.nmissed;
2420
2421 if (!uaddrs)
2422 return 0;
2423 if (ucount < kmulti_link->cnt)
2424 err = -ENOSPC;
2425 else
2426 ucount = kmulti_link->cnt;
2427
2428 if (ucookies) {
2429 if (kmulti_link->cookies) {
2430 if (copy_to_user(ucookies, kmulti_link->cookies, ucount * sizeof(u64)))
2431 return -EFAULT;
2432 } else {
2433 for (i = 0; i < ucount; i++) {
2434 if (put_user(0, ucookies + i))
2435 return -EFAULT;
2436 }
2437 }
2438 }
2439
2440 if (kallsyms_show_value(current_cred())) {
2441 if (copy_to_user(uaddrs, kmulti_link->addrs, ucount * sizeof(u64)))
2442 return -EFAULT;
2443 } else {
2444 for (i = 0; i < ucount; i++) {
2445 if (put_user(0, uaddrs + i))
2446 return -EFAULT;
2447 }
2448 }
2449 return err;
2450 }
2451
2452 #ifdef CONFIG_PROC_FS
bpf_kprobe_multi_show_fdinfo(const struct bpf_link * link,struct seq_file * seq)2453 static void bpf_kprobe_multi_show_fdinfo(const struct bpf_link *link,
2454 struct seq_file *seq)
2455 {
2456 struct bpf_kprobe_multi_link *kmulti_link;
2457 bool has_cookies;
2458
2459 kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);
2460 has_cookies = !!kmulti_link->cookies;
2461
2462 seq_printf(seq,
2463 "kprobe_cnt:\t%u\n"
2464 "missed:\t%lu\n",
2465 kmulti_link->cnt,
2466 kmulti_link->fp.nmissed);
2467
2468 seq_printf(seq, "%s\t %s\n", "cookie", "func");
2469 for (int i = 0; i < kmulti_link->cnt; i++) {
2470 seq_printf(seq,
2471 "%llu\t %pS\n",
2472 has_cookies ? kmulti_link->cookies[i] : 0,
2473 (void *)kmulti_link->addrs[i]);
2474 }
2475 }
2476 #endif
2477
2478 static const struct bpf_link_ops bpf_kprobe_multi_link_lops = {
2479 .release = bpf_kprobe_multi_link_release,
2480 .dealloc_deferred = bpf_kprobe_multi_link_dealloc,
2481 .fill_link_info = bpf_kprobe_multi_link_fill_link_info,
2482 #ifdef CONFIG_PROC_FS
2483 .show_fdinfo = bpf_kprobe_multi_show_fdinfo,
2484 #endif
2485 };
2486
bpf_kprobe_multi_cookie_swap(void * a,void * b,int size,const void * priv)2487 static void bpf_kprobe_multi_cookie_swap(void *a, void *b, int size, const void *priv)
2488 {
2489 const struct bpf_kprobe_multi_link *link = priv;
2490 unsigned long *addr_a = a, *addr_b = b;
2491 u64 *cookie_a, *cookie_b;
2492
2493 cookie_a = link->cookies + (addr_a - link->addrs);
2494 cookie_b = link->cookies + (addr_b - link->addrs);
2495
2496 /* swap addr_a/addr_b and cookie_a/cookie_b values */
2497 swap(*addr_a, *addr_b);
2498 swap(*cookie_a, *cookie_b);
2499 }
2500
bpf_kprobe_multi_addrs_cmp(const void * a,const void * b)2501 static int bpf_kprobe_multi_addrs_cmp(const void *a, const void *b)
2502 {
2503 const unsigned long *addr_a = a, *addr_b = b;
2504
2505 if (*addr_a == *addr_b)
2506 return 0;
2507 return *addr_a < *addr_b ? -1 : 1;
2508 }
2509
bpf_kprobe_multi_cookie_cmp(const void * a,const void * b,const void * priv)2510 static int bpf_kprobe_multi_cookie_cmp(const void *a, const void *b, const void *priv)
2511 {
2512 return bpf_kprobe_multi_addrs_cmp(a, b);
2513 }
2514
bpf_kprobe_multi_cookie(struct bpf_run_ctx * ctx)2515 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx)
2516 {
2517 struct bpf_kprobe_multi_run_ctx *run_ctx;
2518 struct bpf_kprobe_multi_link *link;
2519 u64 *cookie, entry_ip;
2520 unsigned long *addr;
2521
2522 if (WARN_ON_ONCE(!ctx))
2523 return 0;
2524 run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx,
2525 session_ctx.run_ctx);
2526 link = run_ctx->link;
2527 if (!link->cookies)
2528 return 0;
2529 entry_ip = run_ctx->entry_ip;
2530 addr = bsearch(&entry_ip, link->addrs, link->cnt, sizeof(entry_ip),
2531 bpf_kprobe_multi_addrs_cmp);
2532 if (!addr)
2533 return 0;
2534 cookie = link->cookies + (addr - link->addrs);
2535 return *cookie;
2536 }
2537
bpf_kprobe_multi_entry_ip(struct bpf_run_ctx * ctx)2538 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
2539 {
2540 struct bpf_kprobe_multi_run_ctx *run_ctx;
2541
2542 run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx,
2543 session_ctx.run_ctx);
2544 return run_ctx->entry_ip;
2545 }
2546
2547 static __always_inline 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)2548 kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link,
2549 unsigned long entry_ip, struct ftrace_regs *fregs,
2550 bool is_return, void *data)
2551 {
2552 struct bpf_kprobe_multi_run_ctx run_ctx = {
2553 .session_ctx = {
2554 .is_return = is_return,
2555 .data = data,
2556 },
2557 .link = link,
2558 .entry_ip = entry_ip,
2559 };
2560 struct bpf_run_ctx *old_run_ctx;
2561 struct pt_regs *regs;
2562 int err;
2563
2564 /*
2565 * graph tracer framework ensures we won't migrate, so there is no need
2566 * to use migrate_disable for bpf_prog_run again. The check here just for
2567 * __this_cpu_inc_return.
2568 */
2569 cant_sleep();
2570
2571 if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) {
2572 bpf_prog_inc_misses_counter(link->link.prog);
2573 err = 1;
2574 goto out;
2575 }
2576
2577 rcu_read_lock();
2578 regs = ftrace_partial_regs(fregs, bpf_kprobe_multi_pt_regs_ptr());
2579 old_run_ctx = bpf_set_run_ctx(&run_ctx.session_ctx.run_ctx);
2580 err = bpf_prog_run(link->link.prog, regs);
2581 bpf_reset_run_ctx(old_run_ctx);
2582 ftrace_partial_regs_update(fregs, bpf_kprobe_multi_pt_regs_ptr());
2583 rcu_read_unlock();
2584
2585 out:
2586 __this_cpu_dec(bpf_prog_active);
2587 return err;
2588 }
2589
2590 static int
kprobe_multi_link_handler(struct fprobe * fp,unsigned long fentry_ip,unsigned long ret_ip,struct ftrace_regs * fregs,void * data)2591 kprobe_multi_link_handler(struct fprobe *fp, unsigned long fentry_ip,
2592 unsigned long ret_ip, struct ftrace_regs *fregs,
2593 void *data)
2594 {
2595 struct bpf_kprobe_multi_link *link;
2596 int err;
2597
2598 link = container_of(fp, struct bpf_kprobe_multi_link, fp);
2599 err = kprobe_multi_link_prog_run(link, ftrace_get_entry_ip(fentry_ip),
2600 fregs, false, data);
2601 return is_kprobe_session(link->link.prog) ? err : 0;
2602 }
2603
2604 static void
kprobe_multi_link_exit_handler(struct fprobe * fp,unsigned long fentry_ip,unsigned long ret_ip,struct ftrace_regs * fregs,void * data)2605 kprobe_multi_link_exit_handler(struct fprobe *fp, unsigned long fentry_ip,
2606 unsigned long ret_ip, struct ftrace_regs *fregs,
2607 void *data)
2608 {
2609 struct bpf_kprobe_multi_link *link;
2610
2611 link = container_of(fp, struct bpf_kprobe_multi_link, fp);
2612 kprobe_multi_link_prog_run(link, ftrace_get_entry_ip(fentry_ip),
2613 fregs, true, data);
2614 }
2615
symbols_cmp_r(const void * a,const void * b,const void * priv)2616 static int symbols_cmp_r(const void *a, const void *b, const void *priv)
2617 {
2618 const char **str_a = (const char **) a;
2619 const char **str_b = (const char **) b;
2620
2621 return strcmp(*str_a, *str_b);
2622 }
2623
2624 struct multi_symbols_sort {
2625 const char **funcs;
2626 u64 *cookies;
2627 };
2628
symbols_swap_r(void * a,void * b,int size,const void * priv)2629 static void symbols_swap_r(void *a, void *b, int size, const void *priv)
2630 {
2631 const struct multi_symbols_sort *data = priv;
2632 const char **name_a = a, **name_b = b;
2633
2634 swap(*name_a, *name_b);
2635
2636 /* If defined, swap also related cookies. */
2637 if (data->cookies) {
2638 u64 *cookie_a, *cookie_b;
2639
2640 cookie_a = data->cookies + (name_a - data->funcs);
2641 cookie_b = data->cookies + (name_b - data->funcs);
2642 swap(*cookie_a, *cookie_b);
2643 }
2644 }
2645
2646 struct modules_array {
2647 struct module **mods;
2648 int mods_cnt;
2649 int mods_cap;
2650 };
2651
add_module(struct modules_array * arr,struct module * mod)2652 static int add_module(struct modules_array *arr, struct module *mod)
2653 {
2654 struct module **mods;
2655
2656 if (arr->mods_cnt == arr->mods_cap) {
2657 arr->mods_cap = max(16, arr->mods_cap * 3 / 2);
2658 mods = krealloc_array(arr->mods, arr->mods_cap, sizeof(*mods), GFP_KERNEL);
2659 if (!mods)
2660 return -ENOMEM;
2661 arr->mods = mods;
2662 }
2663
2664 arr->mods[arr->mods_cnt] = mod;
2665 arr->mods_cnt++;
2666 return 0;
2667 }
2668
has_module(struct modules_array * arr,struct module * mod)2669 static bool has_module(struct modules_array *arr, struct module *mod)
2670 {
2671 int i;
2672
2673 for (i = arr->mods_cnt - 1; i >= 0; i--) {
2674 if (arr->mods[i] == mod)
2675 return true;
2676 }
2677 return false;
2678 }
2679
get_modules_for_addrs(struct module *** mods,unsigned long * addrs,u32 addrs_cnt)2680 static int get_modules_for_addrs(struct module ***mods, unsigned long *addrs, u32 addrs_cnt)
2681 {
2682 struct modules_array arr = {};
2683 u32 i, err = 0;
2684
2685 for (i = 0; i < addrs_cnt; i++) {
2686 bool skip_add = false;
2687 struct module *mod;
2688
2689 scoped_guard(rcu) {
2690 mod = __module_address(addrs[i]);
2691 /* Either no module or it's already stored */
2692 if (!mod || has_module(&arr, mod)) {
2693 skip_add = true;
2694 break; /* scoped_guard */
2695 }
2696 if (!try_module_get(mod))
2697 err = -EINVAL;
2698 }
2699 if (skip_add)
2700 continue;
2701 if (err)
2702 break;
2703 err = add_module(&arr, mod);
2704 if (err) {
2705 module_put(mod);
2706 break;
2707 }
2708 }
2709
2710 /* We return either err < 0 in case of error, ... */
2711 if (err) {
2712 kprobe_multi_put_modules(arr.mods, arr.mods_cnt);
2713 kfree(arr.mods);
2714 return err;
2715 }
2716
2717 /* or number of modules found if everything is ok. */
2718 *mods = arr.mods;
2719 return arr.mods_cnt;
2720 }
2721
addrs_check_error_injection_list(unsigned long * addrs,u32 cnt)2722 static int addrs_check_error_injection_list(unsigned long *addrs, u32 cnt)
2723 {
2724 u32 i;
2725
2726 for (i = 0; i < cnt; i++) {
2727 if (!within_error_injection_list(addrs[i]))
2728 return -EINVAL;
2729 }
2730 return 0;
2731 }
2732
bpf_kprobe_multi_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)2733 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
2734 {
2735 struct bpf_kprobe_multi_link *link = NULL;
2736 struct bpf_link_primer link_primer;
2737 void __user *ucookies;
2738 unsigned long *addrs;
2739 u32 flags, cnt, size;
2740 void __user *uaddrs;
2741 u64 *cookies = NULL;
2742 void __user *usyms;
2743 int err;
2744
2745 /* no support for 32bit archs yet */
2746 if (sizeof(u64) != sizeof(void *))
2747 return -EOPNOTSUPP;
2748
2749 if (attr->link_create.flags)
2750 return -EINVAL;
2751
2752 if (!is_kprobe_multi(prog))
2753 return -EINVAL;
2754
2755 /* kprobe_multi is not allowed to be sleepable. */
2756 if (prog->sleepable)
2757 return -EINVAL;
2758
2759 /* Writing to context is not allowed for kprobes. */
2760 if (prog->aux->kprobe_write_ctx)
2761 return -EINVAL;
2762
2763 flags = attr->link_create.kprobe_multi.flags;
2764 if (flags & ~BPF_F_KPROBE_MULTI_RETURN)
2765 return -EINVAL;
2766
2767 uaddrs = u64_to_user_ptr(attr->link_create.kprobe_multi.addrs);
2768 usyms = u64_to_user_ptr(attr->link_create.kprobe_multi.syms);
2769 if (!!uaddrs == !!usyms)
2770 return -EINVAL;
2771
2772 cnt = attr->link_create.kprobe_multi.cnt;
2773 if (!cnt)
2774 return -EINVAL;
2775 if (cnt > MAX_KPROBE_MULTI_CNT)
2776 return -E2BIG;
2777
2778 size = cnt * sizeof(*addrs);
2779 addrs = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL);
2780 if (!addrs)
2781 return -ENOMEM;
2782
2783 ucookies = u64_to_user_ptr(attr->link_create.kprobe_multi.cookies);
2784 if (ucookies) {
2785 cookies = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL);
2786 if (!cookies) {
2787 err = -ENOMEM;
2788 goto error;
2789 }
2790 if (copy_from_user(cookies, ucookies, size)) {
2791 err = -EFAULT;
2792 goto error;
2793 }
2794 }
2795
2796 if (uaddrs) {
2797 if (copy_from_user(addrs, uaddrs, size)) {
2798 err = -EFAULT;
2799 goto error;
2800 }
2801 } else {
2802 struct multi_symbols_sort data = {
2803 .cookies = cookies,
2804 };
2805 struct user_syms us;
2806
2807 err = copy_user_syms(&us, usyms, cnt);
2808 if (err)
2809 goto error;
2810
2811 if (cookies)
2812 data.funcs = us.syms;
2813
2814 sort_r(us.syms, cnt, sizeof(*us.syms), symbols_cmp_r,
2815 symbols_swap_r, &data);
2816
2817 err = ftrace_lookup_symbols(us.syms, cnt, addrs);
2818 free_user_syms(&us);
2819 if (err)
2820 goto error;
2821 }
2822
2823 if (prog->kprobe_override && addrs_check_error_injection_list(addrs, cnt)) {
2824 err = -EINVAL;
2825 goto error;
2826 }
2827
2828 link = kzalloc_obj(*link);
2829 if (!link) {
2830 err = -ENOMEM;
2831 goto error;
2832 }
2833
2834 bpf_link_init(&link->link, BPF_LINK_TYPE_KPROBE_MULTI,
2835 &bpf_kprobe_multi_link_lops, prog, attr->link_create.attach_type);
2836
2837 err = bpf_link_prime(&link->link, &link_primer);
2838 if (err)
2839 goto error;
2840
2841 if (!(flags & BPF_F_KPROBE_MULTI_RETURN))
2842 link->fp.entry_handler = kprobe_multi_link_handler;
2843 if ((flags & BPF_F_KPROBE_MULTI_RETURN) || is_kprobe_session(prog))
2844 link->fp.exit_handler = kprobe_multi_link_exit_handler;
2845 if (is_kprobe_session(prog))
2846 link->fp.entry_data_size = sizeof(u64);
2847
2848 link->addrs = addrs;
2849 link->cookies = cookies;
2850 link->cnt = cnt;
2851 link->link.flags = flags;
2852
2853 if (cookies) {
2854 /*
2855 * Sorting addresses will trigger sorting cookies as well
2856 * (check bpf_kprobe_multi_cookie_swap). This way we can
2857 * find cookie based on the address in bpf_get_attach_cookie
2858 * helper.
2859 */
2860 sort_r(addrs, cnt, sizeof(*addrs),
2861 bpf_kprobe_multi_cookie_cmp,
2862 bpf_kprobe_multi_cookie_swap,
2863 link);
2864 }
2865
2866 err = get_modules_for_addrs(&link->mods, addrs, cnt);
2867 if (err < 0) {
2868 bpf_link_cleanup(&link_primer);
2869 return err;
2870 }
2871 link->mods_cnt = err;
2872
2873 err = register_fprobe_ips(&link->fp, addrs, cnt);
2874 if (err) {
2875 kprobe_multi_put_modules(link->mods, link->mods_cnt);
2876 bpf_link_cleanup(&link_primer);
2877 return err;
2878 }
2879
2880 return bpf_link_settle(&link_primer);
2881
2882 error:
2883 kfree(link);
2884 kvfree(addrs);
2885 kvfree(cookies);
2886 return err;
2887 }
2888 #else /* !CONFIG_FPROBE */
bpf_kprobe_multi_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)2889 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
2890 {
2891 return -EOPNOTSUPP;
2892 }
bpf_kprobe_multi_cookie(struct bpf_run_ctx * ctx)2893 static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx)
2894 {
2895 return 0;
2896 }
bpf_kprobe_multi_entry_ip(struct bpf_run_ctx * ctx)2897 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
2898 {
2899 return 0;
2900 }
2901 #endif
2902
2903 #ifdef CONFIG_UPROBES
2904 struct bpf_uprobe_multi_link;
2905
2906 struct bpf_uprobe {
2907 struct bpf_uprobe_multi_link *link;
2908 loff_t offset;
2909 unsigned long ref_ctr_offset;
2910 u64 cookie;
2911 struct uprobe *uprobe;
2912 struct uprobe_consumer consumer;
2913 bool session;
2914 };
2915
2916 struct bpf_uprobe_multi_link {
2917 struct path path;
2918 struct bpf_link link;
2919 u32 cnt;
2920 struct bpf_uprobe *uprobes;
2921 struct task_struct *task;
2922 };
2923
2924 struct bpf_uprobe_multi_run_ctx {
2925 struct bpf_session_run_ctx session_ctx;
2926 unsigned long entry_ip;
2927 struct bpf_uprobe *uprobe;
2928 };
2929
bpf_uprobe_unregister(struct bpf_uprobe * uprobes,u32 cnt)2930 static void bpf_uprobe_unregister(struct bpf_uprobe *uprobes, u32 cnt)
2931 {
2932 u32 i;
2933
2934 for (i = 0; i < cnt; i++)
2935 uprobe_unregister_nosync(uprobes[i].uprobe, &uprobes[i].consumer);
2936
2937 if (cnt)
2938 uprobe_unregister_sync();
2939 }
2940
bpf_uprobe_multi_link_release(struct bpf_link * link)2941 static void bpf_uprobe_multi_link_release(struct bpf_link *link)
2942 {
2943 struct bpf_uprobe_multi_link *umulti_link;
2944
2945 umulti_link = container_of(link, struct bpf_uprobe_multi_link, link);
2946 bpf_uprobe_unregister(umulti_link->uprobes, umulti_link->cnt);
2947 if (umulti_link->task)
2948 put_task_struct(umulti_link->task);
2949 path_put(&umulti_link->path);
2950 }
2951
bpf_uprobe_multi_link_dealloc(struct bpf_link * link)2952 static void bpf_uprobe_multi_link_dealloc(struct bpf_link *link)
2953 {
2954 struct bpf_uprobe_multi_link *umulti_link;
2955
2956 umulti_link = container_of(link, struct bpf_uprobe_multi_link, link);
2957 kvfree(umulti_link->uprobes);
2958 kfree(umulti_link);
2959 }
2960
bpf_uprobe_multi_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)2961 static int bpf_uprobe_multi_link_fill_link_info(const struct bpf_link *link,
2962 struct bpf_link_info *info)
2963 {
2964 u64 __user *uref_ctr_offsets = u64_to_user_ptr(info->uprobe_multi.ref_ctr_offsets);
2965 u64 __user *ucookies = u64_to_user_ptr(info->uprobe_multi.cookies);
2966 u64 __user *uoffsets = u64_to_user_ptr(info->uprobe_multi.offsets);
2967 u64 __user *upath = u64_to_user_ptr(info->uprobe_multi.path);
2968 u32 upath_size = info->uprobe_multi.path_size;
2969 struct bpf_uprobe_multi_link *umulti_link;
2970 u32 ucount = info->uprobe_multi.count;
2971 int err = 0, i;
2972 char *p, *buf;
2973 long left = 0;
2974
2975 if (!upath ^ !upath_size)
2976 return -EINVAL;
2977
2978 if ((uoffsets || uref_ctr_offsets || ucookies) && !ucount)
2979 return -EINVAL;
2980
2981 umulti_link = container_of(link, struct bpf_uprobe_multi_link, link);
2982 info->uprobe_multi.count = umulti_link->cnt;
2983 info->uprobe_multi.flags = umulti_link->link.flags;
2984 info->uprobe_multi.pid = umulti_link->task ?
2985 task_pid_nr_ns(umulti_link->task, task_active_pid_ns(current)) : 0;
2986
2987 upath_size = upath_size ? min_t(u32, upath_size, PATH_MAX) : PATH_MAX;
2988 buf = kmalloc(upath_size, GFP_KERNEL);
2989 if (!buf)
2990 return -ENOMEM;
2991 p = d_path(&umulti_link->path, buf, upath_size);
2992 if (IS_ERR(p)) {
2993 kfree(buf);
2994 return PTR_ERR(p);
2995 }
2996 upath_size = buf + upath_size - p;
2997
2998 if (upath)
2999 left = copy_to_user(upath, p, upath_size);
3000 kfree(buf);
3001 if (left)
3002 return -EFAULT;
3003 info->uprobe_multi.path_size = upath_size;
3004
3005 if (!uoffsets && !ucookies && !uref_ctr_offsets)
3006 return 0;
3007
3008 if (ucount < umulti_link->cnt)
3009 err = -ENOSPC;
3010 else
3011 ucount = umulti_link->cnt;
3012
3013 for (i = 0; i < ucount; i++) {
3014 if (uoffsets &&
3015 put_user(umulti_link->uprobes[i].offset, uoffsets + i))
3016 return -EFAULT;
3017 if (uref_ctr_offsets &&
3018 put_user(umulti_link->uprobes[i].ref_ctr_offset, uref_ctr_offsets + i))
3019 return -EFAULT;
3020 if (ucookies &&
3021 put_user(umulti_link->uprobes[i].cookie, ucookies + i))
3022 return -EFAULT;
3023 }
3024
3025 return err;
3026 }
3027
3028 #ifdef CONFIG_PROC_FS
bpf_uprobe_multi_show_fdinfo(const struct bpf_link * link,struct seq_file * seq)3029 static void bpf_uprobe_multi_show_fdinfo(const struct bpf_link *link,
3030 struct seq_file *seq)
3031 {
3032 struct bpf_uprobe_multi_link *umulti_link;
3033 char *p, *buf;
3034 pid_t pid;
3035
3036 umulti_link = container_of(link, struct bpf_uprobe_multi_link, link);
3037
3038 buf = kmalloc(PATH_MAX, GFP_KERNEL);
3039 if (!buf)
3040 return;
3041
3042 p = d_path(&umulti_link->path, buf, PATH_MAX);
3043 if (IS_ERR(p)) {
3044 kfree(buf);
3045 return;
3046 }
3047
3048 pid = umulti_link->task ?
3049 task_pid_nr_ns(umulti_link->task, task_active_pid_ns(current)) : 0;
3050 seq_printf(seq,
3051 "uprobe_cnt:\t%u\n"
3052 "pid:\t%u\n"
3053 "path:\t%s\n",
3054 umulti_link->cnt, pid, p);
3055
3056 seq_printf(seq, "%s\t %s\t %s\n", "cookie", "offset", "ref_ctr_offset");
3057 for (int i = 0; i < umulti_link->cnt; i++) {
3058 seq_printf(seq,
3059 "%llu\t %#llx\t %#lx\n",
3060 umulti_link->uprobes[i].cookie,
3061 umulti_link->uprobes[i].offset,
3062 umulti_link->uprobes[i].ref_ctr_offset);
3063 }
3064
3065 kfree(buf);
3066 }
3067 #endif
3068
3069 static const struct bpf_link_ops bpf_uprobe_multi_link_lops = {
3070 .release = bpf_uprobe_multi_link_release,
3071 .dealloc_deferred = bpf_uprobe_multi_link_dealloc,
3072 .fill_link_info = bpf_uprobe_multi_link_fill_link_info,
3073 #ifdef CONFIG_PROC_FS
3074 .show_fdinfo = bpf_uprobe_multi_show_fdinfo,
3075 #endif
3076 };
3077
uprobe_prog_run(struct bpf_uprobe * uprobe,unsigned long entry_ip,struct pt_regs * regs,bool is_return,void * data)3078 static int uprobe_prog_run(struct bpf_uprobe *uprobe,
3079 unsigned long entry_ip,
3080 struct pt_regs *regs,
3081 bool is_return, void *data)
3082 {
3083 struct bpf_uprobe_multi_link *link = uprobe->link;
3084 struct bpf_uprobe_multi_run_ctx run_ctx = {
3085 .session_ctx = {
3086 .is_return = is_return,
3087 .data = data,
3088 },
3089 .entry_ip = entry_ip,
3090 .uprobe = uprobe,
3091 };
3092 struct bpf_prog *prog = link->link.prog;
3093 bool sleepable = prog->sleepable;
3094 struct bpf_run_ctx *old_run_ctx;
3095 int err;
3096
3097 if (link->task && !same_thread_group(current, link->task))
3098 return 0;
3099
3100 if (sleepable)
3101 rcu_read_lock_trace();
3102 else
3103 rcu_read_lock();
3104
3105 migrate_disable();
3106
3107 old_run_ctx = bpf_set_run_ctx(&run_ctx.session_ctx.run_ctx);
3108 err = bpf_prog_run(link->link.prog, regs);
3109 bpf_reset_run_ctx(old_run_ctx);
3110
3111 migrate_enable();
3112
3113 if (sleepable)
3114 rcu_read_unlock_trace();
3115 else
3116 rcu_read_unlock();
3117 return err;
3118 }
3119
3120 static bool
uprobe_multi_link_filter(struct uprobe_consumer * con,struct mm_struct * mm)3121 uprobe_multi_link_filter(struct uprobe_consumer *con, struct mm_struct *mm)
3122 {
3123 struct bpf_uprobe *uprobe;
3124
3125 uprobe = container_of(con, struct bpf_uprobe, consumer);
3126 return uprobe->link->task->mm == mm;
3127 }
3128
3129 static int
uprobe_multi_link_handler(struct uprobe_consumer * con,struct pt_regs * regs,__u64 * data)3130 uprobe_multi_link_handler(struct uprobe_consumer *con, struct pt_regs *regs,
3131 __u64 *data)
3132 {
3133 struct bpf_uprobe *uprobe;
3134 int ret;
3135
3136 uprobe = container_of(con, struct bpf_uprobe, consumer);
3137 ret = uprobe_prog_run(uprobe, instruction_pointer(regs), regs, false, data);
3138 if (uprobe->session)
3139 return ret ? UPROBE_HANDLER_IGNORE : 0;
3140 return 0;
3141 }
3142
3143 static int
uprobe_multi_link_ret_handler(struct uprobe_consumer * con,unsigned long func,struct pt_regs * regs,__u64 * data)3144 uprobe_multi_link_ret_handler(struct uprobe_consumer *con, unsigned long func, struct pt_regs *regs,
3145 __u64 *data)
3146 {
3147 struct bpf_uprobe *uprobe;
3148
3149 uprobe = container_of(con, struct bpf_uprobe, consumer);
3150 uprobe_prog_run(uprobe, func, regs, true, data);
3151 return 0;
3152 }
3153
bpf_uprobe_multi_entry_ip(struct bpf_run_ctx * ctx)3154 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
3155 {
3156 struct bpf_uprobe_multi_run_ctx *run_ctx;
3157
3158 run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx,
3159 session_ctx.run_ctx);
3160 return run_ctx->entry_ip;
3161 }
3162
bpf_uprobe_multi_cookie(struct bpf_run_ctx * ctx)3163 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx)
3164 {
3165 struct bpf_uprobe_multi_run_ctx *run_ctx;
3166
3167 run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx,
3168 session_ctx.run_ctx);
3169 return run_ctx->uprobe->cookie;
3170 }
3171
bpf_uprobe_multi_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)3172 int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
3173 {
3174 struct bpf_uprobe_multi_link *link = NULL;
3175 unsigned long __user *uref_ctr_offsets;
3176 struct bpf_link_primer link_primer;
3177 struct bpf_uprobe *uprobes = NULL;
3178 struct task_struct *task = NULL;
3179 unsigned long __user *uoffsets;
3180 u64 __user *ucookies;
3181 void __user *upath;
3182 u32 flags, cnt, i;
3183 struct path path;
3184 char *name;
3185 pid_t pid;
3186 int err;
3187
3188 /* no support for 32bit archs yet */
3189 if (sizeof(u64) != sizeof(void *))
3190 return -EOPNOTSUPP;
3191
3192 if (attr->link_create.flags)
3193 return -EINVAL;
3194
3195 if (!is_uprobe_multi(prog))
3196 return -EINVAL;
3197
3198 flags = attr->link_create.uprobe_multi.flags;
3199 if (flags & ~BPF_F_UPROBE_MULTI_RETURN)
3200 return -EINVAL;
3201
3202 /*
3203 * path, offsets and cnt are mandatory,
3204 * ref_ctr_offsets and cookies are optional
3205 */
3206 upath = u64_to_user_ptr(attr->link_create.uprobe_multi.path);
3207 uoffsets = u64_to_user_ptr(attr->link_create.uprobe_multi.offsets);
3208 cnt = attr->link_create.uprobe_multi.cnt;
3209 pid = attr->link_create.uprobe_multi.pid;
3210
3211 if (!upath || !uoffsets || !cnt || pid < 0)
3212 return -EINVAL;
3213 if (cnt > MAX_UPROBE_MULTI_CNT)
3214 return -E2BIG;
3215
3216 uref_ctr_offsets = u64_to_user_ptr(attr->link_create.uprobe_multi.ref_ctr_offsets);
3217 ucookies = u64_to_user_ptr(attr->link_create.uprobe_multi.cookies);
3218
3219 name = strndup_user(upath, PATH_MAX);
3220 if (IS_ERR(name)) {
3221 err = PTR_ERR(name);
3222 return err;
3223 }
3224
3225 err = kern_path(name, LOOKUP_FOLLOW, &path);
3226 kfree(name);
3227 if (err)
3228 return err;
3229
3230 if (!d_is_reg(path.dentry)) {
3231 err = -EBADF;
3232 goto error_path_put;
3233 }
3234
3235 if (pid) {
3236 rcu_read_lock();
3237 task = get_pid_task(find_vpid(pid), PIDTYPE_TGID);
3238 rcu_read_unlock();
3239 if (!task) {
3240 err = -ESRCH;
3241 goto error_path_put;
3242 }
3243 }
3244
3245 err = -ENOMEM;
3246
3247 link = kzalloc_obj(*link);
3248 uprobes = kvzalloc_objs(*uprobes, cnt);
3249
3250 if (!uprobes || !link)
3251 goto error_free;
3252
3253 for (i = 0; i < cnt; i++) {
3254 if (__get_user(uprobes[i].offset, uoffsets + i)) {
3255 err = -EFAULT;
3256 goto error_free;
3257 }
3258 if (uprobes[i].offset < 0) {
3259 err = -EINVAL;
3260 goto error_free;
3261 }
3262 if (uref_ctr_offsets && __get_user(uprobes[i].ref_ctr_offset, uref_ctr_offsets + i)) {
3263 err = -EFAULT;
3264 goto error_free;
3265 }
3266 if (ucookies && __get_user(uprobes[i].cookie, ucookies + i)) {
3267 err = -EFAULT;
3268 goto error_free;
3269 }
3270
3271 uprobes[i].link = link;
3272
3273 if (!(flags & BPF_F_UPROBE_MULTI_RETURN))
3274 uprobes[i].consumer.handler = uprobe_multi_link_handler;
3275 if (flags & BPF_F_UPROBE_MULTI_RETURN || is_uprobe_session(prog))
3276 uprobes[i].consumer.ret_handler = uprobe_multi_link_ret_handler;
3277 if (is_uprobe_session(prog))
3278 uprobes[i].session = true;
3279 if (pid)
3280 uprobes[i].consumer.filter = uprobe_multi_link_filter;
3281 }
3282
3283 link->cnt = cnt;
3284 link->uprobes = uprobes;
3285 link->path = path;
3286 link->task = task;
3287 link->link.flags = flags;
3288
3289 bpf_link_init(&link->link, BPF_LINK_TYPE_UPROBE_MULTI,
3290 &bpf_uprobe_multi_link_lops, prog, attr->link_create.attach_type);
3291
3292 for (i = 0; i < cnt; i++) {
3293 uprobes[i].uprobe = uprobe_register(d_real_inode(link->path.dentry),
3294 uprobes[i].offset,
3295 uprobes[i].ref_ctr_offset,
3296 &uprobes[i].consumer);
3297 if (IS_ERR(uprobes[i].uprobe)) {
3298 err = PTR_ERR(uprobes[i].uprobe);
3299 link->cnt = i;
3300 goto error_unregister;
3301 }
3302 }
3303
3304 err = bpf_link_prime(&link->link, &link_primer);
3305 if (err)
3306 goto error_unregister;
3307
3308 return bpf_link_settle(&link_primer);
3309
3310 error_unregister:
3311 bpf_uprobe_unregister(uprobes, link->cnt);
3312
3313 error_free:
3314 kvfree(uprobes);
3315 kfree(link);
3316 if (task)
3317 put_task_struct(task);
3318 error_path_put:
3319 path_put(&path);
3320 return err;
3321 }
3322 #else /* !CONFIG_UPROBES */
bpf_uprobe_multi_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)3323 int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
3324 {
3325 return -EOPNOTSUPP;
3326 }
bpf_uprobe_multi_cookie(struct bpf_run_ctx * ctx)3327 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx)
3328 {
3329 return 0;
3330 }
bpf_uprobe_multi_entry_ip(struct bpf_run_ctx * ctx)3331 static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
3332 {
3333 return 0;
3334 }
3335 #endif /* CONFIG_UPROBES */
3336
3337 __bpf_kfunc_start_defs();
3338
bpf_session_is_return(void * ctx)3339 __bpf_kfunc bool bpf_session_is_return(void *ctx)
3340 {
3341 struct bpf_session_run_ctx *session_ctx;
3342
3343 session_ctx = container_of(current->bpf_ctx, struct bpf_session_run_ctx, run_ctx);
3344 return session_ctx->is_return;
3345 }
3346
bpf_session_cookie(void * ctx)3347 __bpf_kfunc __u64 *bpf_session_cookie(void *ctx)
3348 {
3349 struct bpf_session_run_ctx *session_ctx;
3350
3351 session_ctx = container_of(current->bpf_ctx, struct bpf_session_run_ctx, run_ctx);
3352 return session_ctx->data;
3353 }
3354
3355 __bpf_kfunc_end_defs();
3356
3357 BTF_KFUNCS_START(session_kfunc_set_ids)
BTF_ID_FLAGS(func,bpf_session_is_return)3358 BTF_ID_FLAGS(func, bpf_session_is_return)
3359 BTF_ID_FLAGS(func, bpf_session_cookie)
3360 BTF_KFUNCS_END(session_kfunc_set_ids)
3361
3362 static int bpf_session_filter(const struct bpf_prog *prog, u32 kfunc_id)
3363 {
3364 if (!btf_id_set8_contains(&session_kfunc_set_ids, kfunc_id))
3365 return 0;
3366
3367 if (!is_kprobe_session(prog) && !is_uprobe_session(prog) && !is_trace_fsession(prog))
3368 return -EACCES;
3369
3370 return 0;
3371 }
3372
3373 static const struct btf_kfunc_id_set bpf_session_kfunc_set = {
3374 .owner = THIS_MODULE,
3375 .set = &session_kfunc_set_ids,
3376 .filter = bpf_session_filter,
3377 };
3378
bpf_trace_kfuncs_init(void)3379 static int __init bpf_trace_kfuncs_init(void)
3380 {
3381 int err = 0;
3382
3383 err = err ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_KPROBE, &bpf_session_kfunc_set);
3384 err = err ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, &bpf_session_kfunc_set);
3385
3386 return err;
3387 }
3388
3389 late_initcall(bpf_trace_kfuncs_init);
3390
3391 typedef int (*copy_fn_t)(void *dst, const void *src, u32 size, struct task_struct *tsk);
3392
3393 /*
3394 * The __always_inline is to make sure the compiler doesn't
3395 * generate indirect calls into callbacks, which is expensive,
3396 * on some kernel configurations. This allows compiler to put
3397 * direct calls into all the specific callback implementations
3398 * (copy_user_data_sleepable, copy_user_data_nofault, and so on)
3399 */
__bpf_dynptr_copy_str(struct bpf_dynptr * dptr,u64 doff,u64 size,const void * unsafe_src,copy_fn_t str_copy_fn,struct task_struct * tsk)3400 static __always_inline int __bpf_dynptr_copy_str(struct bpf_dynptr *dptr, u64 doff, u64 size,
3401 const void *unsafe_src,
3402 copy_fn_t str_copy_fn,
3403 struct task_struct *tsk)
3404 {
3405 struct bpf_dynptr_kern *dst;
3406 u64 chunk_sz, off;
3407 void *dst_slice;
3408 int cnt, err;
3409 char buf[256];
3410
3411 dst_slice = bpf_dynptr_slice_rdwr(dptr, doff, NULL, size);
3412 if (likely(dst_slice))
3413 return str_copy_fn(dst_slice, unsafe_src, size, tsk);
3414
3415 dst = (struct bpf_dynptr_kern *)dptr;
3416 if (bpf_dynptr_check_off_len(dst, doff, size))
3417 return -E2BIG;
3418
3419 for (off = 0; off < size; off += chunk_sz - 1) {
3420 chunk_sz = min_t(u64, sizeof(buf), size - off);
3421 /* Expect str_copy_fn to return count of copied bytes, including
3422 * zero terminator. Next iteration increment off by chunk_sz - 1 to
3423 * overwrite NUL.
3424 */
3425 cnt = str_copy_fn(buf, unsafe_src + off, chunk_sz, tsk);
3426 if (cnt < 0)
3427 return cnt;
3428 err = __bpf_dynptr_write(dst, doff + off, buf, cnt, 0);
3429 if (err)
3430 return err;
3431 if (cnt < chunk_sz || chunk_sz == 1) /* we are done */
3432 return off + cnt;
3433 }
3434 return off;
3435 }
3436
__bpf_dynptr_copy(const struct bpf_dynptr * dptr,u64 doff,u64 size,const void * unsafe_src,copy_fn_t copy_fn,struct task_struct * tsk)3437 static __always_inline int __bpf_dynptr_copy(const struct bpf_dynptr *dptr, u64 doff,
3438 u64 size, const void *unsafe_src,
3439 copy_fn_t copy_fn, struct task_struct *tsk)
3440 {
3441 struct bpf_dynptr_kern *dst;
3442 void *dst_slice;
3443 char buf[256];
3444 u64 off, chunk_sz;
3445 int err;
3446
3447 dst_slice = bpf_dynptr_slice_rdwr(dptr, doff, NULL, size);
3448 if (likely(dst_slice))
3449 return copy_fn(dst_slice, unsafe_src, size, tsk);
3450
3451 dst = (struct bpf_dynptr_kern *)dptr;
3452 if (bpf_dynptr_check_off_len(dst, doff, size))
3453 return -E2BIG;
3454
3455 for (off = 0; off < size; off += chunk_sz) {
3456 chunk_sz = min_t(u64, sizeof(buf), size - off);
3457 err = copy_fn(buf, unsafe_src + off, chunk_sz, tsk);
3458 if (err)
3459 return err;
3460 err = __bpf_dynptr_write(dst, doff + off, buf, chunk_sz, 0);
3461 if (err)
3462 return err;
3463 }
3464 return 0;
3465 }
3466
copy_user_data_nofault(void * dst,const void * unsafe_src,u32 size,struct task_struct * tsk)3467 static __always_inline int copy_user_data_nofault(void *dst, const void *unsafe_src,
3468 u32 size, struct task_struct *tsk)
3469 {
3470 return copy_from_user_nofault(dst, (const void __user *)unsafe_src, size);
3471 }
3472
copy_user_data_sleepable(void * dst,const void * unsafe_src,u32 size,struct task_struct * tsk)3473 static __always_inline int copy_user_data_sleepable(void *dst, const void *unsafe_src,
3474 u32 size, struct task_struct *tsk)
3475 {
3476 int ret;
3477
3478 if (!tsk) { /* Read from the current task */
3479 ret = copy_from_user(dst, (const void __user *)unsafe_src, size);
3480 if (ret)
3481 return -EFAULT;
3482 return 0;
3483 }
3484
3485 ret = access_process_vm(tsk, (unsigned long)unsafe_src, dst, size, 0);
3486 if (ret != size)
3487 return -EFAULT;
3488 return 0;
3489 }
3490
copy_kernel_data_nofault(void * dst,const void * unsafe_src,u32 size,struct task_struct * tsk)3491 static __always_inline int copy_kernel_data_nofault(void *dst, const void *unsafe_src,
3492 u32 size, struct task_struct *tsk)
3493 {
3494 return copy_from_kernel_nofault(dst, unsafe_src, size);
3495 }
3496
copy_user_str_nofault(void * dst,const void * unsafe_src,u32 size,struct task_struct * tsk)3497 static __always_inline int copy_user_str_nofault(void *dst, const void *unsafe_src,
3498 u32 size, struct task_struct *tsk)
3499 {
3500 return strncpy_from_user_nofault(dst, (const void __user *)unsafe_src, size);
3501 }
3502
copy_user_str_sleepable(void * dst,const void * unsafe_src,u32 size,struct task_struct * tsk)3503 static __always_inline int copy_user_str_sleepable(void *dst, const void *unsafe_src,
3504 u32 size, struct task_struct *tsk)
3505 {
3506 int ret;
3507
3508 if (unlikely(size == 0))
3509 return 0;
3510
3511 if (tsk) {
3512 ret = copy_remote_vm_str(tsk, (unsigned long)unsafe_src, dst, size, 0);
3513 } else {
3514 ret = strncpy_from_user(dst, (const void __user *)unsafe_src, size - 1);
3515 /* strncpy_from_user does not guarantee NUL termination */
3516 if (ret >= 0)
3517 ((char *)dst)[ret] = '\0';
3518 }
3519
3520 if (ret < 0)
3521 return ret;
3522 return ret + 1;
3523 }
3524
copy_kernel_str_nofault(void * dst,const void * unsafe_src,u32 size,struct task_struct * tsk)3525 static __always_inline int copy_kernel_str_nofault(void *dst, const void *unsafe_src,
3526 u32 size, struct task_struct *tsk)
3527 {
3528 return strncpy_from_kernel_nofault(dst, unsafe_src, size);
3529 }
3530
3531 __bpf_kfunc_start_defs();
3532
bpf_send_signal_task(struct task_struct * task,int sig,enum pid_type type,u64 value)3533 __bpf_kfunc int bpf_send_signal_task(struct task_struct *task, int sig, enum pid_type type,
3534 u64 value)
3535 {
3536 if (type != PIDTYPE_PID && type != PIDTYPE_TGID)
3537 return -EINVAL;
3538
3539 return bpf_send_signal_common(sig, type, task, value);
3540 }
3541
bpf_probe_read_user_dynptr(struct bpf_dynptr * dptr,u64 off,u64 size,const void __user * unsafe_ptr__ign)3542 __bpf_kfunc int bpf_probe_read_user_dynptr(struct bpf_dynptr *dptr, u64 off,
3543 u64 size, const void __user *unsafe_ptr__ign)
3544 {
3545 return __bpf_dynptr_copy(dptr, off, size, (const void __force *)unsafe_ptr__ign,
3546 copy_user_data_nofault, NULL);
3547 }
3548
bpf_probe_read_kernel_dynptr(struct bpf_dynptr * dptr,u64 off,u64 size,const void * unsafe_ptr__ign)3549 __bpf_kfunc int bpf_probe_read_kernel_dynptr(struct bpf_dynptr *dptr, u64 off,
3550 u64 size, const void *unsafe_ptr__ign)
3551 {
3552 return __bpf_dynptr_copy(dptr, off, size, unsafe_ptr__ign,
3553 copy_kernel_data_nofault, NULL);
3554 }
3555
bpf_probe_read_user_str_dynptr(struct bpf_dynptr * dptr,u64 off,u64 size,const void __user * unsafe_ptr__ign)3556 __bpf_kfunc int bpf_probe_read_user_str_dynptr(struct bpf_dynptr *dptr, u64 off,
3557 u64 size, const void __user *unsafe_ptr__ign)
3558 {
3559 return __bpf_dynptr_copy_str(dptr, off, size, (const void __force *)unsafe_ptr__ign,
3560 copy_user_str_nofault, NULL);
3561 }
3562
bpf_probe_read_kernel_str_dynptr(struct bpf_dynptr * dptr,u64 off,u64 size,const void * unsafe_ptr__ign)3563 __bpf_kfunc int bpf_probe_read_kernel_str_dynptr(struct bpf_dynptr *dptr, u64 off,
3564 u64 size, const void *unsafe_ptr__ign)
3565 {
3566 return __bpf_dynptr_copy_str(dptr, off, size, unsafe_ptr__ign,
3567 copy_kernel_str_nofault, NULL);
3568 }
3569
bpf_copy_from_user_dynptr(struct bpf_dynptr * dptr,u64 off,u64 size,const void __user * unsafe_ptr__ign)3570 __bpf_kfunc int bpf_copy_from_user_dynptr(struct bpf_dynptr *dptr, u64 off,
3571 u64 size, const void __user *unsafe_ptr__ign)
3572 {
3573 return __bpf_dynptr_copy(dptr, off, size, (const void __force *)unsafe_ptr__ign,
3574 copy_user_data_sleepable, NULL);
3575 }
3576
bpf_copy_from_user_str_dynptr(struct bpf_dynptr * dptr,u64 off,u64 size,const void __user * unsafe_ptr__ign)3577 __bpf_kfunc int bpf_copy_from_user_str_dynptr(struct bpf_dynptr *dptr, u64 off,
3578 u64 size, const void __user *unsafe_ptr__ign)
3579 {
3580 return __bpf_dynptr_copy_str(dptr, off, size, (const void __force *)unsafe_ptr__ign,
3581 copy_user_str_sleepable, NULL);
3582 }
3583
bpf_copy_from_user_task_dynptr(struct bpf_dynptr * dptr,u64 off,u64 size,const void __user * unsafe_ptr__ign,struct task_struct * tsk)3584 __bpf_kfunc int bpf_copy_from_user_task_dynptr(struct bpf_dynptr *dptr, u64 off,
3585 u64 size, const void __user *unsafe_ptr__ign,
3586 struct task_struct *tsk)
3587 {
3588 return __bpf_dynptr_copy(dptr, off, size, (const void __force *)unsafe_ptr__ign,
3589 copy_user_data_sleepable, tsk);
3590 }
3591
bpf_copy_from_user_task_str_dynptr(struct bpf_dynptr * dptr,u64 off,u64 size,const void __user * unsafe_ptr__ign,struct task_struct * tsk)3592 __bpf_kfunc int bpf_copy_from_user_task_str_dynptr(struct bpf_dynptr *dptr, u64 off,
3593 u64 size, const void __user *unsafe_ptr__ign,
3594 struct task_struct *tsk)
3595 {
3596 return __bpf_dynptr_copy_str(dptr, off, size, (const void __force *)unsafe_ptr__ign,
3597 copy_user_str_sleepable, tsk);
3598 }
3599
3600 __bpf_kfunc_end_defs();
3601