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1// SPDX-License-Identifier: GPL-2.0-only
2/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
3 * Copyright (c) 2016,2017 Facebook
4 */
5#include <linux/bpf.h>
6#include <linux/btf.h>
7#include <linux/err.h>
8#include <linux/slab.h>
9#include <linux/mm.h>
10#include <linux/filter.h>
11#include <linux/perf_event.h>
12#include <uapi/linux/btf.h>
13#include <linux/rcupdate_trace.h>
14#include <linux/btf_ids.h>
15
16#include "map_in_map.h"
17
18#define ARRAY_CREATE_FLAG_MASK \
19 (BPF_F_NUMA_NODE | BPF_F_MMAPABLE | BPF_F_ACCESS_MASK | \
20 BPF_F_PRESERVE_ELEMS | BPF_F_INNER_MAP)
21
22static void bpf_array_free_percpu(struct bpf_array *array)
23{
24 int i;
25
26 for (i = 0; i < array->map.max_entries; i++) {
27 free_percpu(array->pptrs[i]);
28 cond_resched();
29 }
30}
31
32static int bpf_array_alloc_percpu(struct bpf_array *array)
33{
34 void __percpu *ptr;
35 int i;
36
37 for (i = 0; i < array->map.max_entries; i++) {
38 ptr = bpf_map_alloc_percpu(&array->map, array->elem_size, 8,
39 GFP_USER | __GFP_NOWARN);
40 if (!ptr) {
41 bpf_array_free_percpu(array);
42 return -ENOMEM;
43 }
44 array->pptrs[i] = ptr;
45 cond_resched();
46 }
47
48 return 0;
49}
50
51/* Called from syscall */
52int array_map_alloc_check(union bpf_attr *attr)
53{
54 bool percpu = attr->map_type == BPF_MAP_TYPE_PERCPU_ARRAY;
55 int numa_node = bpf_map_attr_numa_node(attr);
56
57 /* check sanity of attributes */
58 if (attr->max_entries == 0 || attr->key_size != 4 ||
59 attr->value_size == 0 ||
60 attr->map_flags & ~ARRAY_CREATE_FLAG_MASK ||
61 !bpf_map_flags_access_ok(attr->map_flags) ||
62 (percpu && numa_node != NUMA_NO_NODE))
63 return -EINVAL;
64
65 if (attr->map_type != BPF_MAP_TYPE_ARRAY &&
66 attr->map_flags & (BPF_F_MMAPABLE | BPF_F_INNER_MAP))
67 return -EINVAL;
68
69 if (attr->map_type != BPF_MAP_TYPE_PERF_EVENT_ARRAY &&
70 attr->map_flags & BPF_F_PRESERVE_ELEMS)
71 return -EINVAL;
72
73 /* avoid overflow on round_up(map->value_size) */
74 if (attr->value_size > INT_MAX)
75 return -E2BIG;
76 /* percpu map value size is bound by PCPU_MIN_UNIT_SIZE */
77 if (percpu && round_up(attr->value_size, 8) > PCPU_MIN_UNIT_SIZE)
78 return -E2BIG;
79
80 return 0;
81}
82
83static struct bpf_map *array_map_alloc(union bpf_attr *attr)
84{
85 bool percpu = attr->map_type == BPF_MAP_TYPE_PERCPU_ARRAY;
86 int numa_node = bpf_map_attr_numa_node(attr);
87 u32 elem_size, index_mask, max_entries;
88 bool bypass_spec_v1 = bpf_bypass_spec_v1(NULL);
89 u64 array_size, mask64;
90 struct bpf_array *array;
91
92 elem_size = round_up(attr->value_size, 8);
93
94 max_entries = attr->max_entries;
95
96 /* On 32 bit archs roundup_pow_of_two() with max_entries that has
97 * upper most bit set in u32 space is undefined behavior due to
98 * resulting 1U << 32, so do it manually here in u64 space.
99 */
100 mask64 = fls_long(max_entries - 1);
101 mask64 = 1ULL << mask64;
102 mask64 -= 1;
103
104 index_mask = mask64;
105 if (!bypass_spec_v1) {
106 /* round up array size to nearest power of 2,
107 * since cpu will speculate within index_mask limits
108 */
109 max_entries = index_mask + 1;
110 /* Check for overflows. */
111 if (max_entries < attr->max_entries)
112 return ERR_PTR(-E2BIG);
113 }
114
115 array_size = sizeof(*array);
116 if (percpu) {
117 array_size += (u64) max_entries * sizeof(void *);
118 } else {
119 /* rely on vmalloc() to return page-aligned memory and
120 * ensure array->value is exactly page-aligned
121 */
122 if (attr->map_flags & BPF_F_MMAPABLE) {
123 array_size = PAGE_ALIGN(array_size);
124 array_size += PAGE_ALIGN((u64) max_entries * elem_size);
125 } else {
126 array_size += (u64) max_entries * elem_size;
127 }
128 }
129
130 /* allocate all map elements and zero-initialize them */
131 if (attr->map_flags & BPF_F_MMAPABLE) {
132 void *data;
133
134 /* kmalloc'ed memory can't be mmap'ed, use explicit vmalloc */
135 data = bpf_map_area_mmapable_alloc(array_size, numa_node);
136 if (!data)
137 return ERR_PTR(-ENOMEM);
138 array = data + PAGE_ALIGN(sizeof(struct bpf_array))
139 - offsetof(struct bpf_array, value);
140 } else {
141 array = bpf_map_area_alloc(array_size, numa_node);
142 }
143 if (!array)
144 return ERR_PTR(-ENOMEM);
145 array->index_mask = index_mask;
146 array->map.bypass_spec_v1 = bypass_spec_v1;
147
148 /* copy mandatory map attributes */
149 bpf_map_init_from_attr(&array->map, attr);
150 array->elem_size = elem_size;
151
152 if (percpu && bpf_array_alloc_percpu(array)) {
153 bpf_map_area_free(array);
154 return ERR_PTR(-ENOMEM);
155 }
156
157 return &array->map;
158}
159
160static void *array_map_elem_ptr(struct bpf_array* array, u32 index)
161{
162 return array->value + (u64)array->elem_size * index;
163}
164
165/* Called from syscall or from eBPF program */
166static void *array_map_lookup_elem(struct bpf_map *map, void *key)
167{
168 struct bpf_array *array = container_of(map, struct bpf_array, map);
169 u32 index = *(u32 *)key;
170
171 if (unlikely(index >= array->map.max_entries))
172 return NULL;
173
174 return array->value + (u64)array->elem_size * (index & array->index_mask);
175}
176
177static int array_map_direct_value_addr(const struct bpf_map *map, u64 *imm,
178 u32 off)
179{
180 struct bpf_array *array = container_of(map, struct bpf_array, map);
181
182 if (map->max_entries != 1)
183 return -ENOTSUPP;
184 if (off >= map->value_size)
185 return -EINVAL;
186
187 *imm = (unsigned long)array->value;
188 return 0;
189}
190
191static int array_map_direct_value_meta(const struct bpf_map *map, u64 imm,
192 u32 *off)
193{
194 struct bpf_array *array = container_of(map, struct bpf_array, map);
195 u64 base = (unsigned long)array->value;
196 u64 range = array->elem_size;
197
198 if (map->max_entries != 1)
199 return -ENOTSUPP;
200 if (imm < base || imm >= base + range)
201 return -ENOENT;
202
203 *off = imm - base;
204 return 0;
205}
206
207/* emit BPF instructions equivalent to C code of array_map_lookup_elem() */
208static int array_map_gen_lookup(struct bpf_map *map, struct bpf_insn *insn_buf)
209{
210 struct bpf_array *array = container_of(map, struct bpf_array, map);
211 struct bpf_insn *insn = insn_buf;
212 u32 elem_size = array->elem_size;
213 const int ret = BPF_REG_0;
214 const int map_ptr = BPF_REG_1;
215 const int index = BPF_REG_2;
216
217 if (map->map_flags & BPF_F_INNER_MAP)
218 return -EOPNOTSUPP;
219
220 *insn++ = BPF_ALU64_IMM(BPF_ADD, map_ptr, offsetof(struct bpf_array, value));
221 *insn++ = BPF_LDX_MEM(BPF_W, ret, index, 0);
222 if (!map->bypass_spec_v1) {
223 *insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 4);
224 *insn++ = BPF_ALU32_IMM(BPF_AND, ret, array->index_mask);
225 } else {
226 *insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 3);
227 }
228
229 if (is_power_of_2(elem_size)) {
230 *insn++ = BPF_ALU64_IMM(BPF_LSH, ret, ilog2(elem_size));
231 } else {
232 *insn++ = BPF_ALU64_IMM(BPF_MUL, ret, elem_size);
233 }
234 *insn++ = BPF_ALU64_REG(BPF_ADD, ret, map_ptr);
235 *insn++ = BPF_JMP_IMM(BPF_JA, 0, 0, 1);
236 *insn++ = BPF_MOV64_IMM(ret, 0);
237 return insn - insn_buf;
238}
239
240/* Called from eBPF program */
241static void *percpu_array_map_lookup_elem(struct bpf_map *map, void *key)
242{
243 struct bpf_array *array = container_of(map, struct bpf_array, map);
244 u32 index = *(u32 *)key;
245
246 if (unlikely(index >= array->map.max_entries))
247 return NULL;
248
249 return this_cpu_ptr(array->pptrs[index & array->index_mask]);
250}
251
252/* emit BPF instructions equivalent to C code of percpu_array_map_lookup_elem() */
253static int percpu_array_map_gen_lookup(struct bpf_map *map, struct bpf_insn *insn_buf)
254{
255 struct bpf_array *array = container_of(map, struct bpf_array, map);
256 struct bpf_insn *insn = insn_buf;
257
258 if (!bpf_jit_supports_percpu_insn())
259 return -EOPNOTSUPP;
260
261 if (map->map_flags & BPF_F_INNER_MAP)
262 return -EOPNOTSUPP;
263
264 BUILD_BUG_ON(offsetof(struct bpf_array, map) != 0);
265 *insn++ = BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, offsetof(struct bpf_array, pptrs));
266
267 *insn++ = BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_2, 0);
268 if (!map->bypass_spec_v1) {
269 *insn++ = BPF_JMP_IMM(BPF_JGE, BPF_REG_0, map->max_entries, 6);
270 *insn++ = BPF_ALU32_IMM(BPF_AND, BPF_REG_0, array->index_mask);
271 } else {
272 *insn++ = BPF_JMP_IMM(BPF_JGE, BPF_REG_0, map->max_entries, 5);
273 }
274
275 *insn++ = BPF_ALU64_IMM(BPF_LSH, BPF_REG_0, 3);
276 *insn++ = BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_1);
277 *insn++ = BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_0, 0);
278 *insn++ = BPF_MOV64_PERCPU_REG(BPF_REG_0, BPF_REG_0);
279 *insn++ = BPF_JMP_IMM(BPF_JA, 0, 0, 1);
280 *insn++ = BPF_MOV64_IMM(BPF_REG_0, 0);
281 return insn - insn_buf;
282}
283
284static void *percpu_array_map_lookup_percpu_elem(struct bpf_map *map, void *key, u32 cpu)
285{
286 struct bpf_array *array = container_of(map, struct bpf_array, map);
287 u32 index = *(u32 *)key;
288
289 if (cpu >= nr_cpu_ids)
290 return NULL;
291
292 if (unlikely(index >= array->map.max_entries))
293 return NULL;
294
295 return per_cpu_ptr(array->pptrs[index & array->index_mask], cpu);
296}
297
298int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value)
299{
300 struct bpf_array *array = container_of(map, struct bpf_array, map);
301 u32 index = *(u32 *)key;
302 void __percpu *pptr;
303 int cpu, off = 0;
304 u32 size;
305
306 if (unlikely(index >= array->map.max_entries))
307 return -ENOENT;
308
309 /* per_cpu areas are zero-filled and bpf programs can only
310 * access 'value_size' of them, so copying rounded areas
311 * will not leak any kernel data
312 */
313 size = array->elem_size;
314 rcu_read_lock();
315 pptr = array->pptrs[index & array->index_mask];
316 for_each_possible_cpu(cpu) {
317 copy_map_value_long(map, value + off, per_cpu_ptr(pptr, cpu));
318 check_and_init_map_value(map, value + off);
319 off += size;
320 }
321 rcu_read_unlock();
322 return 0;
323}
324
325/* Called from syscall */
326static int array_map_get_next_key(struct bpf_map *map, void *key, void *next_key)
327{
328 struct bpf_array *array = container_of(map, struct bpf_array, map);
329 u32 index = key ? *(u32 *)key : U32_MAX;
330 u32 *next = (u32 *)next_key;
331
332 if (index >= array->map.max_entries) {
333 *next = 0;
334 return 0;
335 }
336
337 if (index == array->map.max_entries - 1)
338 return -ENOENT;
339
340 *next = index + 1;
341 return 0;
342}
343
344/* Called from syscall or from eBPF program */
345static long array_map_update_elem(struct bpf_map *map, void *key, void *value,
346 u64 map_flags)
347{
348 struct bpf_array *array = container_of(map, struct bpf_array, map);
349 u32 index = *(u32 *)key;
350 char *val;
351
352 if (unlikely((map_flags & ~BPF_F_LOCK) > BPF_EXIST))
353 /* unknown flags */
354 return -EINVAL;
355
356 if (unlikely(index >= array->map.max_entries))
357 /* all elements were pre-allocated, cannot insert a new one */
358 return -E2BIG;
359
360 if (unlikely(map_flags & BPF_NOEXIST))
361 /* all elements already exist */
362 return -EEXIST;
363
364 if (unlikely((map_flags & BPF_F_LOCK) &&
365 !btf_record_has_field(map->record, BPF_SPIN_LOCK)))
366 return -EINVAL;
367
368 if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
369 val = this_cpu_ptr(array->pptrs[index & array->index_mask]);
370 copy_map_value(map, val, value);
371 bpf_obj_free_fields(array->map.record, val);
372 } else {
373 val = array->value +
374 (u64)array->elem_size * (index & array->index_mask);
375 if (map_flags & BPF_F_LOCK)
376 copy_map_value_locked(map, val, value, false);
377 else
378 copy_map_value(map, val, value);
379 bpf_obj_free_fields(array->map.record, val);
380 }
381 return 0;
382}
383
384int bpf_percpu_array_update(struct bpf_map *map, void *key, void *value,
385 u64 map_flags)
386{
387 struct bpf_array *array = container_of(map, struct bpf_array, map);
388 u32 index = *(u32 *)key;
389 void __percpu *pptr;
390 int cpu, off = 0;
391 u32 size;
392
393 if (unlikely(map_flags > BPF_EXIST))
394 /* unknown flags */
395 return -EINVAL;
396
397 if (unlikely(index >= array->map.max_entries))
398 /* all elements were pre-allocated, cannot insert a new one */
399 return -E2BIG;
400
401 if (unlikely(map_flags == BPF_NOEXIST))
402 /* all elements already exist */
403 return -EEXIST;
404
405 /* the user space will provide round_up(value_size, 8) bytes that
406 * will be copied into per-cpu area. bpf programs can only access
407 * value_size of it. During lookup the same extra bytes will be
408 * returned or zeros which were zero-filled by percpu_alloc,
409 * so no kernel data leaks possible
410 */
411 size = array->elem_size;
412 rcu_read_lock();
413 pptr = array->pptrs[index & array->index_mask];
414 for_each_possible_cpu(cpu) {
415 copy_map_value_long(map, per_cpu_ptr(pptr, cpu), value + off);
416 bpf_obj_free_fields(array->map.record, per_cpu_ptr(pptr, cpu));
417 off += size;
418 }
419 rcu_read_unlock();
420 return 0;
421}
422
423/* Called from syscall or from eBPF program */
424static long array_map_delete_elem(struct bpf_map *map, void *key)
425{
426 return -EINVAL;
427}
428
429static void *array_map_vmalloc_addr(struct bpf_array *array)
430{
431 return (void *)round_down((unsigned long)array, PAGE_SIZE);
432}
433
434static void array_map_free_timers_wq(struct bpf_map *map)
435{
436 struct bpf_array *array = container_of(map, struct bpf_array, map);
437 int i;
438
439 /* We don't reset or free fields other than timer and workqueue
440 * on uref dropping to zero.
441 */
442 if (btf_record_has_field(map->record, BPF_TIMER | BPF_WORKQUEUE)) {
443 for (i = 0; i < array->map.max_entries; i++) {
444 if (btf_record_has_field(map->record, BPF_TIMER))
445 bpf_obj_free_timer(map->record, array_map_elem_ptr(array, i));
446 if (btf_record_has_field(map->record, BPF_WORKQUEUE))
447 bpf_obj_free_workqueue(map->record, array_map_elem_ptr(array, i));
448 }
449 }
450}
451
452/* Called when map->refcnt goes to zero, either from workqueue or from syscall */
453static void array_map_free(struct bpf_map *map)
454{
455 struct bpf_array *array = container_of(map, struct bpf_array, map);
456 int i;
457
458 if (!IS_ERR_OR_NULL(map->record)) {
459 if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
460 for (i = 0; i < array->map.max_entries; i++) {
461 void __percpu *pptr = array->pptrs[i & array->index_mask];
462 int cpu;
463
464 for_each_possible_cpu(cpu) {
465 bpf_obj_free_fields(map->record, per_cpu_ptr(pptr, cpu));
466 cond_resched();
467 }
468 }
469 } else {
470 for (i = 0; i < array->map.max_entries; i++)
471 bpf_obj_free_fields(map->record, array_map_elem_ptr(array, i));
472 }
473 }
474
475 if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY)
476 bpf_array_free_percpu(array);
477
478 if (array->map.map_flags & BPF_F_MMAPABLE)
479 bpf_map_area_free(array_map_vmalloc_addr(array));
480 else
481 bpf_map_area_free(array);
482}
483
484static void array_map_seq_show_elem(struct bpf_map *map, void *key,
485 struct seq_file *m)
486{
487 void *value;
488
489 rcu_read_lock();
490
491 value = array_map_lookup_elem(map, key);
492 if (!value) {
493 rcu_read_unlock();
494 return;
495 }
496
497 if (map->btf_key_type_id)
498 seq_printf(m, "%u: ", *(u32 *)key);
499 btf_type_seq_show(map->btf, map->btf_value_type_id, value, m);
500 seq_putc(m, '\n');
501
502 rcu_read_unlock();
503}
504
505static void percpu_array_map_seq_show_elem(struct bpf_map *map, void *key,
506 struct seq_file *m)
507{
508 struct bpf_array *array = container_of(map, struct bpf_array, map);
509 u32 index = *(u32 *)key;
510 void __percpu *pptr;
511 int cpu;
512
513 rcu_read_lock();
514
515 seq_printf(m, "%u: {\n", *(u32 *)key);
516 pptr = array->pptrs[index & array->index_mask];
517 for_each_possible_cpu(cpu) {
518 seq_printf(m, "\tcpu%d: ", cpu);
519 btf_type_seq_show(map->btf, map->btf_value_type_id,
520 per_cpu_ptr(pptr, cpu), m);
521 seq_putc(m, '\n');
522 }
523 seq_puts(m, "}\n");
524
525 rcu_read_unlock();
526}
527
528static int array_map_check_btf(const struct bpf_map *map,
529 const struct btf *btf,
530 const struct btf_type *key_type,
531 const struct btf_type *value_type)
532{
533 u32 int_data;
534
535 /* One exception for keyless BTF: .bss/.data/.rodata map */
536 if (btf_type_is_void(key_type)) {
537 if (map->map_type != BPF_MAP_TYPE_ARRAY ||
538 map->max_entries != 1)
539 return -EINVAL;
540
541 if (BTF_INFO_KIND(value_type->info) != BTF_KIND_DATASEC)
542 return -EINVAL;
543
544 return 0;
545 }
546
547 if (BTF_INFO_KIND(key_type->info) != BTF_KIND_INT)
548 return -EINVAL;
549
550 int_data = *(u32 *)(key_type + 1);
551 /* bpf array can only take a u32 key. This check makes sure
552 * that the btf matches the attr used during map_create.
553 */
554 if (BTF_INT_BITS(int_data) != 32 || BTF_INT_OFFSET(int_data))
555 return -EINVAL;
556
557 return 0;
558}
559
560static int array_map_mmap(struct bpf_map *map, struct vm_area_struct *vma)
561{
562 struct bpf_array *array = container_of(map, struct bpf_array, map);
563 pgoff_t pgoff = PAGE_ALIGN(sizeof(*array)) >> PAGE_SHIFT;
564
565 if (!(map->map_flags & BPF_F_MMAPABLE))
566 return -EINVAL;
567
568 if (vma->vm_pgoff * PAGE_SIZE + (vma->vm_end - vma->vm_start) >
569 PAGE_ALIGN((u64)array->map.max_entries * array->elem_size))
570 return -EINVAL;
571
572 return remap_vmalloc_range(vma, array_map_vmalloc_addr(array),
573 vma->vm_pgoff + pgoff);
574}
575
576static bool array_map_meta_equal(const struct bpf_map *meta0,
577 const struct bpf_map *meta1)
578{
579 if (!bpf_map_meta_equal(meta0, meta1))
580 return false;
581 return meta0->map_flags & BPF_F_INNER_MAP ? true :
582 meta0->max_entries == meta1->max_entries;
583}
584
585struct bpf_iter_seq_array_map_info {
586 struct bpf_map *map;
587 void *percpu_value_buf;
588 u32 index;
589};
590
591static void *bpf_array_map_seq_start(struct seq_file *seq, loff_t *pos)
592{
593 struct bpf_iter_seq_array_map_info *info = seq->private;
594 struct bpf_map *map = info->map;
595 struct bpf_array *array;
596 u32 index;
597
598 if (info->index >= map->max_entries)
599 return NULL;
600
601 if (*pos == 0)
602 ++*pos;
603 array = container_of(map, struct bpf_array, map);
604 index = info->index & array->index_mask;
605 if (info->percpu_value_buf)
606 return (void *)(uintptr_t)array->pptrs[index];
607 return array_map_elem_ptr(array, index);
608}
609
610static void *bpf_array_map_seq_next(struct seq_file *seq, void *v, loff_t *pos)
611{
612 struct bpf_iter_seq_array_map_info *info = seq->private;
613 struct bpf_map *map = info->map;
614 struct bpf_array *array;
615 u32 index;
616
617 ++*pos;
618 ++info->index;
619 if (info->index >= map->max_entries)
620 return NULL;
621
622 array = container_of(map, struct bpf_array, map);
623 index = info->index & array->index_mask;
624 if (info->percpu_value_buf)
625 return (void *)(uintptr_t)array->pptrs[index];
626 return array_map_elem_ptr(array, index);
627}
628
629static int __bpf_array_map_seq_show(struct seq_file *seq, void *v)
630{
631 struct bpf_iter_seq_array_map_info *info = seq->private;
632 struct bpf_iter__bpf_map_elem ctx = {};
633 struct bpf_map *map = info->map;
634 struct bpf_array *array = container_of(map, struct bpf_array, map);
635 struct bpf_iter_meta meta;
636 struct bpf_prog *prog;
637 int off = 0, cpu = 0;
638 void __percpu *pptr;
639 u32 size;
640
641 meta.seq = seq;
642 prog = bpf_iter_get_info(&meta, v == NULL);
643 if (!prog)
644 return 0;
645
646 ctx.meta = &meta;
647 ctx.map = info->map;
648 if (v) {
649 ctx.key = &info->index;
650
651 if (!info->percpu_value_buf) {
652 ctx.value = v;
653 } else {
654 pptr = (void __percpu *)(uintptr_t)v;
655 size = array->elem_size;
656 for_each_possible_cpu(cpu) {
657 copy_map_value_long(map, info->percpu_value_buf + off,
658 per_cpu_ptr(pptr, cpu));
659 check_and_init_map_value(map, info->percpu_value_buf + off);
660 off += size;
661 }
662 ctx.value = info->percpu_value_buf;
663 }
664 }
665
666 return bpf_iter_run_prog(prog, &ctx);
667}
668
669static int bpf_array_map_seq_show(struct seq_file *seq, void *v)
670{
671 return __bpf_array_map_seq_show(seq, v);
672}
673
674static void bpf_array_map_seq_stop(struct seq_file *seq, void *v)
675{
676 if (!v)
677 (void)__bpf_array_map_seq_show(seq, NULL);
678}
679
680static int bpf_iter_init_array_map(void *priv_data,
681 struct bpf_iter_aux_info *aux)
682{
683 struct bpf_iter_seq_array_map_info *seq_info = priv_data;
684 struct bpf_map *map = aux->map;
685 struct bpf_array *array = container_of(map, struct bpf_array, map);
686 void *value_buf;
687 u32 buf_size;
688
689 if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
690 buf_size = array->elem_size * num_possible_cpus();
691 value_buf = kmalloc(buf_size, GFP_USER | __GFP_NOWARN);
692 if (!value_buf)
693 return -ENOMEM;
694
695 seq_info->percpu_value_buf = value_buf;
696 }
697
698 /* bpf_iter_attach_map() acquires a map uref, and the uref may be
699 * released before or in the middle of iterating map elements, so
700 * acquire an extra map uref for iterator.
701 */
702 bpf_map_inc_with_uref(map);
703 seq_info->map = map;
704 return 0;
705}
706
707static void bpf_iter_fini_array_map(void *priv_data)
708{
709 struct bpf_iter_seq_array_map_info *seq_info = priv_data;
710
711 bpf_map_put_with_uref(seq_info->map);
712 kfree(seq_info->percpu_value_buf);
713}
714
715static const struct seq_operations bpf_array_map_seq_ops = {
716 .start = bpf_array_map_seq_start,
717 .next = bpf_array_map_seq_next,
718 .stop = bpf_array_map_seq_stop,
719 .show = bpf_array_map_seq_show,
720};
721
722static const struct bpf_iter_seq_info iter_seq_info = {
723 .seq_ops = &bpf_array_map_seq_ops,
724 .init_seq_private = bpf_iter_init_array_map,
725 .fini_seq_private = bpf_iter_fini_array_map,
726 .seq_priv_size = sizeof(struct bpf_iter_seq_array_map_info),
727};
728
729static long bpf_for_each_array_elem(struct bpf_map *map, bpf_callback_t callback_fn,
730 void *callback_ctx, u64 flags)
731{
732 u32 i, key, num_elems = 0;
733 struct bpf_array *array;
734 bool is_percpu;
735 u64 ret = 0;
736 void *val;
737
738 if (flags != 0)
739 return -EINVAL;
740
741 is_percpu = map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY;
742 array = container_of(map, struct bpf_array, map);
743 if (is_percpu)
744 migrate_disable();
745 for (i = 0; i < map->max_entries; i++) {
746 if (is_percpu)
747 val = this_cpu_ptr(array->pptrs[i]);
748 else
749 val = array_map_elem_ptr(array, i);
750 num_elems++;
751 key = i;
752 ret = callback_fn((u64)(long)map, (u64)(long)&key,
753 (u64)(long)val, (u64)(long)callback_ctx, 0);
754 /* return value: 0 - continue, 1 - stop and return */
755 if (ret)
756 break;
757 }
758
759 if (is_percpu)
760 migrate_enable();
761 return num_elems;
762}
763
764static u64 array_map_mem_usage(const struct bpf_map *map)
765{
766 struct bpf_array *array = container_of(map, struct bpf_array, map);
767 bool percpu = map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY;
768 u32 elem_size = array->elem_size;
769 u64 entries = map->max_entries;
770 u64 usage = sizeof(*array);
771
772 if (percpu) {
773 usage += entries * sizeof(void *);
774 usage += entries * elem_size * num_possible_cpus();
775 } else {
776 if (map->map_flags & BPF_F_MMAPABLE) {
777 usage = PAGE_ALIGN(usage);
778 usage += PAGE_ALIGN(entries * elem_size);
779 } else {
780 usage += entries * elem_size;
781 }
782 }
783 return usage;
784}
785
786BTF_ID_LIST_SINGLE(array_map_btf_ids, struct, bpf_array)
787const struct bpf_map_ops array_map_ops = {
788 .map_meta_equal = array_map_meta_equal,
789 .map_alloc_check = array_map_alloc_check,
790 .map_alloc = array_map_alloc,
791 .map_free = array_map_free,
792 .map_get_next_key = array_map_get_next_key,
793 .map_release_uref = array_map_free_timers_wq,
794 .map_lookup_elem = array_map_lookup_elem,
795 .map_update_elem = array_map_update_elem,
796 .map_delete_elem = array_map_delete_elem,
797 .map_gen_lookup = array_map_gen_lookup,
798 .map_direct_value_addr = array_map_direct_value_addr,
799 .map_direct_value_meta = array_map_direct_value_meta,
800 .map_mmap = array_map_mmap,
801 .map_seq_show_elem = array_map_seq_show_elem,
802 .map_check_btf = array_map_check_btf,
803 .map_lookup_batch = generic_map_lookup_batch,
804 .map_update_batch = generic_map_update_batch,
805 .map_set_for_each_callback_args = map_set_for_each_callback_args,
806 .map_for_each_callback = bpf_for_each_array_elem,
807 .map_mem_usage = array_map_mem_usage,
808 .map_btf_id = &array_map_btf_ids[0],
809 .iter_seq_info = &iter_seq_info,
810};
811
812const struct bpf_map_ops percpu_array_map_ops = {
813 .map_meta_equal = bpf_map_meta_equal,
814 .map_alloc_check = array_map_alloc_check,
815 .map_alloc = array_map_alloc,
816 .map_free = array_map_free,
817 .map_get_next_key = array_map_get_next_key,
818 .map_lookup_elem = percpu_array_map_lookup_elem,
819 .map_gen_lookup = percpu_array_map_gen_lookup,
820 .map_update_elem = array_map_update_elem,
821 .map_delete_elem = array_map_delete_elem,
822 .map_lookup_percpu_elem = percpu_array_map_lookup_percpu_elem,
823 .map_seq_show_elem = percpu_array_map_seq_show_elem,
824 .map_check_btf = array_map_check_btf,
825 .map_lookup_batch = generic_map_lookup_batch,
826 .map_update_batch = generic_map_update_batch,
827 .map_set_for_each_callback_args = map_set_for_each_callback_args,
828 .map_for_each_callback = bpf_for_each_array_elem,
829 .map_mem_usage = array_map_mem_usage,
830 .map_btf_id = &array_map_btf_ids[0],
831 .iter_seq_info = &iter_seq_info,
832};
833
834static int fd_array_map_alloc_check(union bpf_attr *attr)
835{
836 /* only file descriptors can be stored in this type of map */
837 if (attr->value_size != sizeof(u32))
838 return -EINVAL;
839 /* Program read-only/write-only not supported for special maps yet. */
840 if (attr->map_flags & (BPF_F_RDONLY_PROG | BPF_F_WRONLY_PROG))
841 return -EINVAL;
842 return array_map_alloc_check(attr);
843}
844
845static void fd_array_map_free(struct bpf_map *map)
846{
847 struct bpf_array *array = container_of(map, struct bpf_array, map);
848 int i;
849
850 /* make sure it's empty */
851 for (i = 0; i < array->map.max_entries; i++)
852 BUG_ON(array->ptrs[i] != NULL);
853
854 bpf_map_area_free(array);
855}
856
857static void *fd_array_map_lookup_elem(struct bpf_map *map, void *key)
858{
859 return ERR_PTR(-EOPNOTSUPP);
860}
861
862/* only called from syscall */
863int bpf_fd_array_map_lookup_elem(struct bpf_map *map, void *key, u32 *value)
864{
865 void **elem, *ptr;
866 int ret = 0;
867
868 if (!map->ops->map_fd_sys_lookup_elem)
869 return -ENOTSUPP;
870
871 rcu_read_lock();
872 elem = array_map_lookup_elem(map, key);
873 if (elem && (ptr = READ_ONCE(*elem)))
874 *value = map->ops->map_fd_sys_lookup_elem(ptr);
875 else
876 ret = -ENOENT;
877 rcu_read_unlock();
878
879 return ret;
880}
881
882/* only called from syscall */
883int bpf_fd_array_map_update_elem(struct bpf_map *map, struct file *map_file,
884 void *key, void *value, u64 map_flags)
885{
886 struct bpf_array *array = container_of(map, struct bpf_array, map);
887 void *new_ptr, *old_ptr;
888 u32 index = *(u32 *)key, ufd;
889
890 if (map_flags != BPF_ANY)
891 return -EINVAL;
892
893 if (index >= array->map.max_entries)
894 return -E2BIG;
895
896 ufd = *(u32 *)value;
897 new_ptr = map->ops->map_fd_get_ptr(map, map_file, ufd);
898 if (IS_ERR(new_ptr))
899 return PTR_ERR(new_ptr);
900
901 if (map->ops->map_poke_run) {
902 mutex_lock(&array->aux->poke_mutex);
903 old_ptr = xchg(array->ptrs + index, new_ptr);
904 map->ops->map_poke_run(map, index, old_ptr, new_ptr);
905 mutex_unlock(&array->aux->poke_mutex);
906 } else {
907 old_ptr = xchg(array->ptrs + index, new_ptr);
908 }
909
910 if (old_ptr)
911 map->ops->map_fd_put_ptr(map, old_ptr, true);
912 return 0;
913}
914
915static long __fd_array_map_delete_elem(struct bpf_map *map, void *key, bool need_defer)
916{
917 struct bpf_array *array = container_of(map, struct bpf_array, map);
918 void *old_ptr;
919 u32 index = *(u32 *)key;
920
921 if (index >= array->map.max_entries)
922 return -E2BIG;
923
924 if (map->ops->map_poke_run) {
925 mutex_lock(&array->aux->poke_mutex);
926 old_ptr = xchg(array->ptrs + index, NULL);
927 map->ops->map_poke_run(map, index, old_ptr, NULL);
928 mutex_unlock(&array->aux->poke_mutex);
929 } else {
930 old_ptr = xchg(array->ptrs + index, NULL);
931 }
932
933 if (old_ptr) {
934 map->ops->map_fd_put_ptr(map, old_ptr, need_defer);
935 return 0;
936 } else {
937 return -ENOENT;
938 }
939}
940
941static long fd_array_map_delete_elem(struct bpf_map *map, void *key)
942{
943 return __fd_array_map_delete_elem(map, key, true);
944}
945
946static void *prog_fd_array_get_ptr(struct bpf_map *map,
947 struct file *map_file, int fd)
948{
949 struct bpf_prog *prog = bpf_prog_get(fd);
950 bool is_extended;
951
952 if (IS_ERR(prog))
953 return prog;
954
955 if (prog->type == BPF_PROG_TYPE_EXT ||
956 !bpf_prog_map_compatible(map, prog)) {
957 bpf_prog_put(prog);
958 return ERR_PTR(-EINVAL);
959 }
960
961 mutex_lock(&prog->aux->ext_mutex);
962 is_extended = prog->aux->is_extended;
963 if (!is_extended)
964 prog->aux->prog_array_member_cnt++;
965 mutex_unlock(&prog->aux->ext_mutex);
966 if (is_extended) {
967 /* Extended prog can not be tail callee. It's to prevent a
968 * potential infinite loop like:
969 * tail callee prog entry -> tail callee prog subprog ->
970 * freplace prog entry --tailcall-> tail callee prog entry.
971 */
972 bpf_prog_put(prog);
973 return ERR_PTR(-EBUSY);
974 }
975
976 return prog;
977}
978
979static void prog_fd_array_put_ptr(struct bpf_map *map, void *ptr, bool need_defer)
980{
981 struct bpf_prog *prog = ptr;
982
983 mutex_lock(&prog->aux->ext_mutex);
984 prog->aux->prog_array_member_cnt--;
985 mutex_unlock(&prog->aux->ext_mutex);
986 /* bpf_prog is freed after one RCU or tasks trace grace period */
987 bpf_prog_put(prog);
988}
989
990static u32 prog_fd_array_sys_lookup_elem(void *ptr)
991{
992 return ((struct bpf_prog *)ptr)->aux->id;
993}
994
995/* decrement refcnt of all bpf_progs that are stored in this map */
996static void bpf_fd_array_map_clear(struct bpf_map *map, bool need_defer)
997{
998 struct bpf_array *array = container_of(map, struct bpf_array, map);
999 int i;
1000
1001 for (i = 0; i < array->map.max_entries; i++)
1002 __fd_array_map_delete_elem(map, &i, need_defer);
1003}
1004
1005static void prog_array_map_seq_show_elem(struct bpf_map *map, void *key,
1006 struct seq_file *m)
1007{
1008 void **elem, *ptr;
1009 u32 prog_id;
1010
1011 rcu_read_lock();
1012
1013 elem = array_map_lookup_elem(map, key);
1014 if (elem) {
1015 ptr = READ_ONCE(*elem);
1016 if (ptr) {
1017 seq_printf(m, "%u: ", *(u32 *)key);
1018 prog_id = prog_fd_array_sys_lookup_elem(ptr);
1019 btf_type_seq_show(map->btf, map->btf_value_type_id,
1020 &prog_id, m);
1021 seq_putc(m, '\n');
1022 }
1023 }
1024
1025 rcu_read_unlock();
1026}
1027
1028struct prog_poke_elem {
1029 struct list_head list;
1030 struct bpf_prog_aux *aux;
1031};
1032
1033static int prog_array_map_poke_track(struct bpf_map *map,
1034 struct bpf_prog_aux *prog_aux)
1035{
1036 struct prog_poke_elem *elem;
1037 struct bpf_array_aux *aux;
1038 int ret = 0;
1039
1040 aux = container_of(map, struct bpf_array, map)->aux;
1041 mutex_lock(&aux->poke_mutex);
1042 list_for_each_entry(elem, &aux->poke_progs, list) {
1043 if (elem->aux == prog_aux)
1044 goto out;
1045 }
1046
1047 elem = kmalloc(sizeof(*elem), GFP_KERNEL);
1048 if (!elem) {
1049 ret = -ENOMEM;
1050 goto out;
1051 }
1052
1053 INIT_LIST_HEAD(&elem->list);
1054 /* We must track the program's aux info at this point in time
1055 * since the program pointer itself may not be stable yet, see
1056 * also comment in prog_array_map_poke_run().
1057 */
1058 elem->aux = prog_aux;
1059
1060 list_add_tail(&elem->list, &aux->poke_progs);
1061out:
1062 mutex_unlock(&aux->poke_mutex);
1063 return ret;
1064}
1065
1066static void prog_array_map_poke_untrack(struct bpf_map *map,
1067 struct bpf_prog_aux *prog_aux)
1068{
1069 struct prog_poke_elem *elem, *tmp;
1070 struct bpf_array_aux *aux;
1071
1072 aux = container_of(map, struct bpf_array, map)->aux;
1073 mutex_lock(&aux->poke_mutex);
1074 list_for_each_entry_safe(elem, tmp, &aux->poke_progs, list) {
1075 if (elem->aux == prog_aux) {
1076 list_del_init(&elem->list);
1077 kfree(elem);
1078 break;
1079 }
1080 }
1081 mutex_unlock(&aux->poke_mutex);
1082}
1083
1084void __weak bpf_arch_poke_desc_update(struct bpf_jit_poke_descriptor *poke,
1085 struct bpf_prog *new, struct bpf_prog *old)
1086{
1087 WARN_ON_ONCE(1);
1088}
1089
1090static void prog_array_map_poke_run(struct bpf_map *map, u32 key,
1091 struct bpf_prog *old,
1092 struct bpf_prog *new)
1093{
1094 struct prog_poke_elem *elem;
1095 struct bpf_array_aux *aux;
1096
1097 aux = container_of(map, struct bpf_array, map)->aux;
1098 WARN_ON_ONCE(!mutex_is_locked(&aux->poke_mutex));
1099
1100 list_for_each_entry(elem, &aux->poke_progs, list) {
1101 struct bpf_jit_poke_descriptor *poke;
1102 int i;
1103
1104 for (i = 0; i < elem->aux->size_poke_tab; i++) {
1105 poke = &elem->aux->poke_tab[i];
1106
1107 /* Few things to be aware of:
1108 *
1109 * 1) We can only ever access aux in this context, but
1110 * not aux->prog since it might not be stable yet and
1111 * there could be danger of use after free otherwise.
1112 * 2) Initially when we start tracking aux, the program
1113 * is not JITed yet and also does not have a kallsyms
1114 * entry. We skip these as poke->tailcall_target_stable
1115 * is not active yet. The JIT will do the final fixup
1116 * before setting it stable. The various
1117 * poke->tailcall_target_stable are successively
1118 * activated, so tail call updates can arrive from here
1119 * while JIT is still finishing its final fixup for
1120 * non-activated poke entries.
1121 * 3) Also programs reaching refcount of zero while patching
1122 * is in progress is okay since we're protected under
1123 * poke_mutex and untrack the programs before the JIT
1124 * buffer is freed.
1125 */
1126 if (!READ_ONCE(poke->tailcall_target_stable))
1127 continue;
1128 if (poke->reason != BPF_POKE_REASON_TAIL_CALL)
1129 continue;
1130 if (poke->tail_call.map != map ||
1131 poke->tail_call.key != key)
1132 continue;
1133
1134 bpf_arch_poke_desc_update(poke, new, old);
1135 }
1136 }
1137}
1138
1139static void prog_array_map_clear_deferred(struct work_struct *work)
1140{
1141 struct bpf_map *map = container_of(work, struct bpf_array_aux,
1142 work)->map;
1143 bpf_fd_array_map_clear(map, true);
1144 bpf_map_put(map);
1145}
1146
1147static void prog_array_map_clear(struct bpf_map *map)
1148{
1149 struct bpf_array_aux *aux = container_of(map, struct bpf_array,
1150 map)->aux;
1151 bpf_map_inc(map);
1152 schedule_work(&aux->work);
1153}
1154
1155static struct bpf_map *prog_array_map_alloc(union bpf_attr *attr)
1156{
1157 struct bpf_array_aux *aux;
1158 struct bpf_map *map;
1159
1160 aux = kzalloc(sizeof(*aux), GFP_KERNEL_ACCOUNT);
1161 if (!aux)
1162 return ERR_PTR(-ENOMEM);
1163
1164 INIT_WORK(&aux->work, prog_array_map_clear_deferred);
1165 INIT_LIST_HEAD(&aux->poke_progs);
1166 mutex_init(&aux->poke_mutex);
1167
1168 map = array_map_alloc(attr);
1169 if (IS_ERR(map)) {
1170 kfree(aux);
1171 return map;
1172 }
1173
1174 container_of(map, struct bpf_array, map)->aux = aux;
1175 aux->map = map;
1176
1177 return map;
1178}
1179
1180static void prog_array_map_free(struct bpf_map *map)
1181{
1182 struct prog_poke_elem *elem, *tmp;
1183 struct bpf_array_aux *aux;
1184
1185 aux = container_of(map, struct bpf_array, map)->aux;
1186 list_for_each_entry_safe(elem, tmp, &aux->poke_progs, list) {
1187 list_del_init(&elem->list);
1188 kfree(elem);
1189 }
1190 kfree(aux);
1191 fd_array_map_free(map);
1192}
1193
1194/* prog_array->aux->{type,jited} is a runtime binding.
1195 * Doing static check alone in the verifier is not enough.
1196 * Thus, prog_array_map cannot be used as an inner_map
1197 * and map_meta_equal is not implemented.
1198 */
1199const struct bpf_map_ops prog_array_map_ops = {
1200 .map_alloc_check = fd_array_map_alloc_check,
1201 .map_alloc = prog_array_map_alloc,
1202 .map_free = prog_array_map_free,
1203 .map_poke_track = prog_array_map_poke_track,
1204 .map_poke_untrack = prog_array_map_poke_untrack,
1205 .map_poke_run = prog_array_map_poke_run,
1206 .map_get_next_key = array_map_get_next_key,
1207 .map_lookup_elem = fd_array_map_lookup_elem,
1208 .map_delete_elem = fd_array_map_delete_elem,
1209 .map_fd_get_ptr = prog_fd_array_get_ptr,
1210 .map_fd_put_ptr = prog_fd_array_put_ptr,
1211 .map_fd_sys_lookup_elem = prog_fd_array_sys_lookup_elem,
1212 .map_release_uref = prog_array_map_clear,
1213 .map_seq_show_elem = prog_array_map_seq_show_elem,
1214 .map_mem_usage = array_map_mem_usage,
1215 .map_btf_id = &array_map_btf_ids[0],
1216};
1217
1218static struct bpf_event_entry *bpf_event_entry_gen(struct file *perf_file,
1219 struct file *map_file)
1220{
1221 struct bpf_event_entry *ee;
1222
1223 ee = kzalloc(sizeof(*ee), GFP_KERNEL);
1224 if (ee) {
1225 ee->event = perf_file->private_data;
1226 ee->perf_file = perf_file;
1227 ee->map_file = map_file;
1228 }
1229
1230 return ee;
1231}
1232
1233static void __bpf_event_entry_free(struct rcu_head *rcu)
1234{
1235 struct bpf_event_entry *ee;
1236
1237 ee = container_of(rcu, struct bpf_event_entry, rcu);
1238 fput(ee->perf_file);
1239 kfree(ee);
1240}
1241
1242static void bpf_event_entry_free_rcu(struct bpf_event_entry *ee)
1243{
1244 call_rcu(&ee->rcu, __bpf_event_entry_free);
1245}
1246
1247static void *perf_event_fd_array_get_ptr(struct bpf_map *map,
1248 struct file *map_file, int fd)
1249{
1250 struct bpf_event_entry *ee;
1251 struct perf_event *event;
1252 struct file *perf_file;
1253 u64 value;
1254
1255 perf_file = perf_event_get(fd);
1256 if (IS_ERR(perf_file))
1257 return perf_file;
1258
1259 ee = ERR_PTR(-EOPNOTSUPP);
1260 event = perf_file->private_data;
1261 if (perf_event_read_local(event, &value, NULL, NULL) == -EOPNOTSUPP)
1262 goto err_out;
1263
1264 ee = bpf_event_entry_gen(perf_file, map_file);
1265 if (ee)
1266 return ee;
1267 ee = ERR_PTR(-ENOMEM);
1268err_out:
1269 fput(perf_file);
1270 return ee;
1271}
1272
1273static void perf_event_fd_array_put_ptr(struct bpf_map *map, void *ptr, bool need_defer)
1274{
1275 /* bpf_perf_event is freed after one RCU grace period */
1276 bpf_event_entry_free_rcu(ptr);
1277}
1278
1279static void perf_event_fd_array_release(struct bpf_map *map,
1280 struct file *map_file)
1281{
1282 struct bpf_array *array = container_of(map, struct bpf_array, map);
1283 struct bpf_event_entry *ee;
1284 int i;
1285
1286 if (map->map_flags & BPF_F_PRESERVE_ELEMS)
1287 return;
1288
1289 rcu_read_lock();
1290 for (i = 0; i < array->map.max_entries; i++) {
1291 ee = READ_ONCE(array->ptrs[i]);
1292 if (ee && ee->map_file == map_file)
1293 __fd_array_map_delete_elem(map, &i, true);
1294 }
1295 rcu_read_unlock();
1296}
1297
1298static void perf_event_fd_array_map_free(struct bpf_map *map)
1299{
1300 if (map->map_flags & BPF_F_PRESERVE_ELEMS)
1301 bpf_fd_array_map_clear(map, false);
1302 fd_array_map_free(map);
1303}
1304
1305const struct bpf_map_ops perf_event_array_map_ops = {
1306 .map_meta_equal = bpf_map_meta_equal,
1307 .map_alloc_check = fd_array_map_alloc_check,
1308 .map_alloc = array_map_alloc,
1309 .map_free = perf_event_fd_array_map_free,
1310 .map_get_next_key = array_map_get_next_key,
1311 .map_lookup_elem = fd_array_map_lookup_elem,
1312 .map_delete_elem = fd_array_map_delete_elem,
1313 .map_fd_get_ptr = perf_event_fd_array_get_ptr,
1314 .map_fd_put_ptr = perf_event_fd_array_put_ptr,
1315 .map_release = perf_event_fd_array_release,
1316 .map_check_btf = map_check_no_btf,
1317 .map_mem_usage = array_map_mem_usage,
1318 .map_btf_id = &array_map_btf_ids[0],
1319};
1320
1321#ifdef CONFIG_CGROUPS
1322static void *cgroup_fd_array_get_ptr(struct bpf_map *map,
1323 struct file *map_file /* not used */,
1324 int fd)
1325{
1326 return cgroup_get_from_fd(fd);
1327}
1328
1329static void cgroup_fd_array_put_ptr(struct bpf_map *map, void *ptr, bool need_defer)
1330{
1331 /* cgroup_put free cgrp after a rcu grace period */
1332 cgroup_put(ptr);
1333}
1334
1335static void cgroup_fd_array_free(struct bpf_map *map)
1336{
1337 bpf_fd_array_map_clear(map, false);
1338 fd_array_map_free(map);
1339}
1340
1341const struct bpf_map_ops cgroup_array_map_ops = {
1342 .map_meta_equal = bpf_map_meta_equal,
1343 .map_alloc_check = fd_array_map_alloc_check,
1344 .map_alloc = array_map_alloc,
1345 .map_free = cgroup_fd_array_free,
1346 .map_get_next_key = array_map_get_next_key,
1347 .map_lookup_elem = fd_array_map_lookup_elem,
1348 .map_delete_elem = fd_array_map_delete_elem,
1349 .map_fd_get_ptr = cgroup_fd_array_get_ptr,
1350 .map_fd_put_ptr = cgroup_fd_array_put_ptr,
1351 .map_check_btf = map_check_no_btf,
1352 .map_mem_usage = array_map_mem_usage,
1353 .map_btf_id = &array_map_btf_ids[0],
1354};
1355#endif
1356
1357static struct bpf_map *array_of_map_alloc(union bpf_attr *attr)
1358{
1359 struct bpf_map *map, *inner_map_meta;
1360
1361 inner_map_meta = bpf_map_meta_alloc(attr->inner_map_fd);
1362 if (IS_ERR(inner_map_meta))
1363 return inner_map_meta;
1364
1365 map = array_map_alloc(attr);
1366 if (IS_ERR(map)) {
1367 bpf_map_meta_free(inner_map_meta);
1368 return map;
1369 }
1370
1371 map->inner_map_meta = inner_map_meta;
1372
1373 return map;
1374}
1375
1376static void array_of_map_free(struct bpf_map *map)
1377{
1378 /* map->inner_map_meta is only accessed by syscall which
1379 * is protected by fdget/fdput.
1380 */
1381 bpf_map_meta_free(map->inner_map_meta);
1382 bpf_fd_array_map_clear(map, false);
1383 fd_array_map_free(map);
1384}
1385
1386static void *array_of_map_lookup_elem(struct bpf_map *map, void *key)
1387{
1388 struct bpf_map **inner_map = array_map_lookup_elem(map, key);
1389
1390 if (!inner_map)
1391 return NULL;
1392
1393 return READ_ONCE(*inner_map);
1394}
1395
1396static int array_of_map_gen_lookup(struct bpf_map *map,
1397 struct bpf_insn *insn_buf)
1398{
1399 struct bpf_array *array = container_of(map, struct bpf_array, map);
1400 u32 elem_size = array->elem_size;
1401 struct bpf_insn *insn = insn_buf;
1402 const int ret = BPF_REG_0;
1403 const int map_ptr = BPF_REG_1;
1404 const int index = BPF_REG_2;
1405
1406 *insn++ = BPF_ALU64_IMM(BPF_ADD, map_ptr, offsetof(struct bpf_array, value));
1407 *insn++ = BPF_LDX_MEM(BPF_W, ret, index, 0);
1408 if (!map->bypass_spec_v1) {
1409 *insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 6);
1410 *insn++ = BPF_ALU32_IMM(BPF_AND, ret, array->index_mask);
1411 } else {
1412 *insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 5);
1413 }
1414 if (is_power_of_2(elem_size))
1415 *insn++ = BPF_ALU64_IMM(BPF_LSH, ret, ilog2(elem_size));
1416 else
1417 *insn++ = BPF_ALU64_IMM(BPF_MUL, ret, elem_size);
1418 *insn++ = BPF_ALU64_REG(BPF_ADD, ret, map_ptr);
1419 *insn++ = BPF_LDX_MEM(BPF_DW, ret, ret, 0);
1420 *insn++ = BPF_JMP_IMM(BPF_JEQ, ret, 0, 1);
1421 *insn++ = BPF_JMP_IMM(BPF_JA, 0, 0, 1);
1422 *insn++ = BPF_MOV64_IMM(ret, 0);
1423
1424 return insn - insn_buf;
1425}
1426
1427const struct bpf_map_ops array_of_maps_map_ops = {
1428 .map_alloc_check = fd_array_map_alloc_check,
1429 .map_alloc = array_of_map_alloc,
1430 .map_free = array_of_map_free,
1431 .map_get_next_key = array_map_get_next_key,
1432 .map_lookup_elem = array_of_map_lookup_elem,
1433 .map_delete_elem = fd_array_map_delete_elem,
1434 .map_fd_get_ptr = bpf_map_fd_get_ptr,
1435 .map_fd_put_ptr = bpf_map_fd_put_ptr,
1436 .map_fd_sys_lookup_elem = bpf_map_fd_sys_lookup_elem,
1437 .map_gen_lookup = array_of_map_gen_lookup,
1438 .map_lookup_batch = generic_map_lookup_batch,
1439 .map_update_batch = generic_map_update_batch,
1440 .map_check_btf = map_check_no_btf,
1441 .map_mem_usage = array_map_mem_usage,
1442 .map_btf_id = &array_map_btf_ids[0],
1443};
1// SPDX-License-Identifier: GPL-2.0-only
2/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
3 * Copyright (c) 2016,2017 Facebook
4 */
5#include <linux/bpf.h>
6#include <linux/btf.h>
7#include <linux/err.h>
8#include <linux/slab.h>
9#include <linux/mm.h>
10#include <linux/filter.h>
11#include <linux/perf_event.h>
12#include <uapi/linux/btf.h>
13#include <linux/rcupdate_trace.h>
14
15#include "map_in_map.h"
16
17#define ARRAY_CREATE_FLAG_MASK \
18 (BPF_F_NUMA_NODE | BPF_F_MMAPABLE | BPF_F_ACCESS_MASK | \
19 BPF_F_PRESERVE_ELEMS | BPF_F_INNER_MAP)
20
21static void bpf_array_free_percpu(struct bpf_array *array)
22{
23 int i;
24
25 for (i = 0; i < array->map.max_entries; i++) {
26 free_percpu(array->pptrs[i]);
27 cond_resched();
28 }
29}
30
31static int bpf_array_alloc_percpu(struct bpf_array *array)
32{
33 void __percpu *ptr;
34 int i;
35
36 for (i = 0; i < array->map.max_entries; i++) {
37 ptr = bpf_map_alloc_percpu(&array->map, array->elem_size, 8,
38 GFP_USER | __GFP_NOWARN);
39 if (!ptr) {
40 bpf_array_free_percpu(array);
41 return -ENOMEM;
42 }
43 array->pptrs[i] = ptr;
44 cond_resched();
45 }
46
47 return 0;
48}
49
50/* Called from syscall */
51int array_map_alloc_check(union bpf_attr *attr)
52{
53 bool percpu = attr->map_type == BPF_MAP_TYPE_PERCPU_ARRAY;
54 int numa_node = bpf_map_attr_numa_node(attr);
55
56 /* check sanity of attributes */
57 if (attr->max_entries == 0 || attr->key_size != 4 ||
58 attr->value_size == 0 ||
59 attr->map_flags & ~ARRAY_CREATE_FLAG_MASK ||
60 !bpf_map_flags_access_ok(attr->map_flags) ||
61 (percpu && numa_node != NUMA_NO_NODE))
62 return -EINVAL;
63
64 if (attr->map_type != BPF_MAP_TYPE_ARRAY &&
65 attr->map_flags & (BPF_F_MMAPABLE | BPF_F_INNER_MAP))
66 return -EINVAL;
67
68 if (attr->map_type != BPF_MAP_TYPE_PERF_EVENT_ARRAY &&
69 attr->map_flags & BPF_F_PRESERVE_ELEMS)
70 return -EINVAL;
71
72 if (attr->value_size > KMALLOC_MAX_SIZE)
73 /* if value_size is bigger, the user space won't be able to
74 * access the elements.
75 */
76 return -E2BIG;
77
78 return 0;
79}
80
81static struct bpf_map *array_map_alloc(union bpf_attr *attr)
82{
83 bool percpu = attr->map_type == BPF_MAP_TYPE_PERCPU_ARRAY;
84 int numa_node = bpf_map_attr_numa_node(attr);
85 u32 elem_size, index_mask, max_entries;
86 bool bypass_spec_v1 = bpf_bypass_spec_v1();
87 u64 array_size, mask64;
88 struct bpf_array *array;
89
90 elem_size = round_up(attr->value_size, 8);
91
92 max_entries = attr->max_entries;
93
94 /* On 32 bit archs roundup_pow_of_two() with max_entries that has
95 * upper most bit set in u32 space is undefined behavior due to
96 * resulting 1U << 32, so do it manually here in u64 space.
97 */
98 mask64 = fls_long(max_entries - 1);
99 mask64 = 1ULL << mask64;
100 mask64 -= 1;
101
102 index_mask = mask64;
103 if (!bypass_spec_v1) {
104 /* round up array size to nearest power of 2,
105 * since cpu will speculate within index_mask limits
106 */
107 max_entries = index_mask + 1;
108 /* Check for overflows. */
109 if (max_entries < attr->max_entries)
110 return ERR_PTR(-E2BIG);
111 }
112
113 array_size = sizeof(*array);
114 if (percpu) {
115 array_size += (u64) max_entries * sizeof(void *);
116 } else {
117 /* rely on vmalloc() to return page-aligned memory and
118 * ensure array->value is exactly page-aligned
119 */
120 if (attr->map_flags & BPF_F_MMAPABLE) {
121 array_size = PAGE_ALIGN(array_size);
122 array_size += PAGE_ALIGN((u64) max_entries * elem_size);
123 } else {
124 array_size += (u64) max_entries * elem_size;
125 }
126 }
127
128 /* allocate all map elements and zero-initialize them */
129 if (attr->map_flags & BPF_F_MMAPABLE) {
130 void *data;
131
132 /* kmalloc'ed memory can't be mmap'ed, use explicit vmalloc */
133 data = bpf_map_area_mmapable_alloc(array_size, numa_node);
134 if (!data)
135 return ERR_PTR(-ENOMEM);
136 array = data + PAGE_ALIGN(sizeof(struct bpf_array))
137 - offsetof(struct bpf_array, value);
138 } else {
139 array = bpf_map_area_alloc(array_size, numa_node);
140 }
141 if (!array)
142 return ERR_PTR(-ENOMEM);
143 array->index_mask = index_mask;
144 array->map.bypass_spec_v1 = bypass_spec_v1;
145
146 /* copy mandatory map attributes */
147 bpf_map_init_from_attr(&array->map, attr);
148 array->elem_size = elem_size;
149
150 if (percpu && bpf_array_alloc_percpu(array)) {
151 bpf_map_area_free(array);
152 return ERR_PTR(-ENOMEM);
153 }
154
155 return &array->map;
156}
157
158/* Called from syscall or from eBPF program */
159static void *array_map_lookup_elem(struct bpf_map *map, void *key)
160{
161 struct bpf_array *array = container_of(map, struct bpf_array, map);
162 u32 index = *(u32 *)key;
163
164 if (unlikely(index >= array->map.max_entries))
165 return NULL;
166
167 return array->value + array->elem_size * (index & array->index_mask);
168}
169
170static int array_map_direct_value_addr(const struct bpf_map *map, u64 *imm,
171 u32 off)
172{
173 struct bpf_array *array = container_of(map, struct bpf_array, map);
174
175 if (map->max_entries != 1)
176 return -ENOTSUPP;
177 if (off >= map->value_size)
178 return -EINVAL;
179
180 *imm = (unsigned long)array->value;
181 return 0;
182}
183
184static int array_map_direct_value_meta(const struct bpf_map *map, u64 imm,
185 u32 *off)
186{
187 struct bpf_array *array = container_of(map, struct bpf_array, map);
188 u64 base = (unsigned long)array->value;
189 u64 range = array->elem_size;
190
191 if (map->max_entries != 1)
192 return -ENOTSUPP;
193 if (imm < base || imm >= base + range)
194 return -ENOENT;
195
196 *off = imm - base;
197 return 0;
198}
199
200/* emit BPF instructions equivalent to C code of array_map_lookup_elem() */
201static int array_map_gen_lookup(struct bpf_map *map, struct bpf_insn *insn_buf)
202{
203 struct bpf_array *array = container_of(map, struct bpf_array, map);
204 struct bpf_insn *insn = insn_buf;
205 u32 elem_size = round_up(map->value_size, 8);
206 const int ret = BPF_REG_0;
207 const int map_ptr = BPF_REG_1;
208 const int index = BPF_REG_2;
209
210 if (map->map_flags & BPF_F_INNER_MAP)
211 return -EOPNOTSUPP;
212
213 *insn++ = BPF_ALU64_IMM(BPF_ADD, map_ptr, offsetof(struct bpf_array, value));
214 *insn++ = BPF_LDX_MEM(BPF_W, ret, index, 0);
215 if (!map->bypass_spec_v1) {
216 *insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 4);
217 *insn++ = BPF_ALU32_IMM(BPF_AND, ret, array->index_mask);
218 } else {
219 *insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 3);
220 }
221
222 if (is_power_of_2(elem_size)) {
223 *insn++ = BPF_ALU64_IMM(BPF_LSH, ret, ilog2(elem_size));
224 } else {
225 *insn++ = BPF_ALU64_IMM(BPF_MUL, ret, elem_size);
226 }
227 *insn++ = BPF_ALU64_REG(BPF_ADD, ret, map_ptr);
228 *insn++ = BPF_JMP_IMM(BPF_JA, 0, 0, 1);
229 *insn++ = BPF_MOV64_IMM(ret, 0);
230 return insn - insn_buf;
231}
232
233/* Called from eBPF program */
234static void *percpu_array_map_lookup_elem(struct bpf_map *map, void *key)
235{
236 struct bpf_array *array = container_of(map, struct bpf_array, map);
237 u32 index = *(u32 *)key;
238
239 if (unlikely(index >= array->map.max_entries))
240 return NULL;
241
242 return this_cpu_ptr(array->pptrs[index & array->index_mask]);
243}
244
245int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value)
246{
247 struct bpf_array *array = container_of(map, struct bpf_array, map);
248 u32 index = *(u32 *)key;
249 void __percpu *pptr;
250 int cpu, off = 0;
251 u32 size;
252
253 if (unlikely(index >= array->map.max_entries))
254 return -ENOENT;
255
256 /* per_cpu areas are zero-filled and bpf programs can only
257 * access 'value_size' of them, so copying rounded areas
258 * will not leak any kernel data
259 */
260 size = round_up(map->value_size, 8);
261 rcu_read_lock();
262 pptr = array->pptrs[index & array->index_mask];
263 for_each_possible_cpu(cpu) {
264 bpf_long_memcpy(value + off, per_cpu_ptr(pptr, cpu), size);
265 off += size;
266 }
267 rcu_read_unlock();
268 return 0;
269}
270
271/* Called from syscall */
272static int array_map_get_next_key(struct bpf_map *map, void *key, void *next_key)
273{
274 struct bpf_array *array = container_of(map, struct bpf_array, map);
275 u32 index = key ? *(u32 *)key : U32_MAX;
276 u32 *next = (u32 *)next_key;
277
278 if (index >= array->map.max_entries) {
279 *next = 0;
280 return 0;
281 }
282
283 if (index == array->map.max_entries - 1)
284 return -ENOENT;
285
286 *next = index + 1;
287 return 0;
288}
289
290/* Called from syscall or from eBPF program */
291static int array_map_update_elem(struct bpf_map *map, void *key, void *value,
292 u64 map_flags)
293{
294 struct bpf_array *array = container_of(map, struct bpf_array, map);
295 u32 index = *(u32 *)key;
296 char *val;
297
298 if (unlikely((map_flags & ~BPF_F_LOCK) > BPF_EXIST))
299 /* unknown flags */
300 return -EINVAL;
301
302 if (unlikely(index >= array->map.max_entries))
303 /* all elements were pre-allocated, cannot insert a new one */
304 return -E2BIG;
305
306 if (unlikely(map_flags & BPF_NOEXIST))
307 /* all elements already exist */
308 return -EEXIST;
309
310 if (unlikely((map_flags & BPF_F_LOCK) &&
311 !map_value_has_spin_lock(map)))
312 return -EINVAL;
313
314 if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
315 memcpy(this_cpu_ptr(array->pptrs[index & array->index_mask]),
316 value, map->value_size);
317 } else {
318 val = array->value +
319 array->elem_size * (index & array->index_mask);
320 if (map_flags & BPF_F_LOCK)
321 copy_map_value_locked(map, val, value, false);
322 else
323 copy_map_value(map, val, value);
324 }
325 return 0;
326}
327
328int bpf_percpu_array_update(struct bpf_map *map, void *key, void *value,
329 u64 map_flags)
330{
331 struct bpf_array *array = container_of(map, struct bpf_array, map);
332 u32 index = *(u32 *)key;
333 void __percpu *pptr;
334 int cpu, off = 0;
335 u32 size;
336
337 if (unlikely(map_flags > BPF_EXIST))
338 /* unknown flags */
339 return -EINVAL;
340
341 if (unlikely(index >= array->map.max_entries))
342 /* all elements were pre-allocated, cannot insert a new one */
343 return -E2BIG;
344
345 if (unlikely(map_flags == BPF_NOEXIST))
346 /* all elements already exist */
347 return -EEXIST;
348
349 /* the user space will provide round_up(value_size, 8) bytes that
350 * will be copied into per-cpu area. bpf programs can only access
351 * value_size of it. During lookup the same extra bytes will be
352 * returned or zeros which were zero-filled by percpu_alloc,
353 * so no kernel data leaks possible
354 */
355 size = round_up(map->value_size, 8);
356 rcu_read_lock();
357 pptr = array->pptrs[index & array->index_mask];
358 for_each_possible_cpu(cpu) {
359 bpf_long_memcpy(per_cpu_ptr(pptr, cpu), value + off, size);
360 off += size;
361 }
362 rcu_read_unlock();
363 return 0;
364}
365
366/* Called from syscall or from eBPF program */
367static int array_map_delete_elem(struct bpf_map *map, void *key)
368{
369 return -EINVAL;
370}
371
372static void *array_map_vmalloc_addr(struct bpf_array *array)
373{
374 return (void *)round_down((unsigned long)array, PAGE_SIZE);
375}
376
377/* Called when map->refcnt goes to zero, either from workqueue or from syscall */
378static void array_map_free(struct bpf_map *map)
379{
380 struct bpf_array *array = container_of(map, struct bpf_array, map);
381
382 if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY)
383 bpf_array_free_percpu(array);
384
385 if (array->map.map_flags & BPF_F_MMAPABLE)
386 bpf_map_area_free(array_map_vmalloc_addr(array));
387 else
388 bpf_map_area_free(array);
389}
390
391static void array_map_seq_show_elem(struct bpf_map *map, void *key,
392 struct seq_file *m)
393{
394 void *value;
395
396 rcu_read_lock();
397
398 value = array_map_lookup_elem(map, key);
399 if (!value) {
400 rcu_read_unlock();
401 return;
402 }
403
404 if (map->btf_key_type_id)
405 seq_printf(m, "%u: ", *(u32 *)key);
406 btf_type_seq_show(map->btf, map->btf_value_type_id, value, m);
407 seq_puts(m, "\n");
408
409 rcu_read_unlock();
410}
411
412static void percpu_array_map_seq_show_elem(struct bpf_map *map, void *key,
413 struct seq_file *m)
414{
415 struct bpf_array *array = container_of(map, struct bpf_array, map);
416 u32 index = *(u32 *)key;
417 void __percpu *pptr;
418 int cpu;
419
420 rcu_read_lock();
421
422 seq_printf(m, "%u: {\n", *(u32 *)key);
423 pptr = array->pptrs[index & array->index_mask];
424 for_each_possible_cpu(cpu) {
425 seq_printf(m, "\tcpu%d: ", cpu);
426 btf_type_seq_show(map->btf, map->btf_value_type_id,
427 per_cpu_ptr(pptr, cpu), m);
428 seq_puts(m, "\n");
429 }
430 seq_puts(m, "}\n");
431
432 rcu_read_unlock();
433}
434
435static int array_map_check_btf(const struct bpf_map *map,
436 const struct btf *btf,
437 const struct btf_type *key_type,
438 const struct btf_type *value_type)
439{
440 u32 int_data;
441
442 /* One exception for keyless BTF: .bss/.data/.rodata map */
443 if (btf_type_is_void(key_type)) {
444 if (map->map_type != BPF_MAP_TYPE_ARRAY ||
445 map->max_entries != 1)
446 return -EINVAL;
447
448 if (BTF_INFO_KIND(value_type->info) != BTF_KIND_DATASEC)
449 return -EINVAL;
450
451 return 0;
452 }
453
454 if (BTF_INFO_KIND(key_type->info) != BTF_KIND_INT)
455 return -EINVAL;
456
457 int_data = *(u32 *)(key_type + 1);
458 /* bpf array can only take a u32 key. This check makes sure
459 * that the btf matches the attr used during map_create.
460 */
461 if (BTF_INT_BITS(int_data) != 32 || BTF_INT_OFFSET(int_data))
462 return -EINVAL;
463
464 return 0;
465}
466
467static int array_map_mmap(struct bpf_map *map, struct vm_area_struct *vma)
468{
469 struct bpf_array *array = container_of(map, struct bpf_array, map);
470 pgoff_t pgoff = PAGE_ALIGN(sizeof(*array)) >> PAGE_SHIFT;
471
472 if (!(map->map_flags & BPF_F_MMAPABLE))
473 return -EINVAL;
474
475 if (vma->vm_pgoff * PAGE_SIZE + (vma->vm_end - vma->vm_start) >
476 PAGE_ALIGN((u64)array->map.max_entries * array->elem_size))
477 return -EINVAL;
478
479 return remap_vmalloc_range(vma, array_map_vmalloc_addr(array),
480 vma->vm_pgoff + pgoff);
481}
482
483static bool array_map_meta_equal(const struct bpf_map *meta0,
484 const struct bpf_map *meta1)
485{
486 if (!bpf_map_meta_equal(meta0, meta1))
487 return false;
488 return meta0->map_flags & BPF_F_INNER_MAP ? true :
489 meta0->max_entries == meta1->max_entries;
490}
491
492struct bpf_iter_seq_array_map_info {
493 struct bpf_map *map;
494 void *percpu_value_buf;
495 u32 index;
496};
497
498static void *bpf_array_map_seq_start(struct seq_file *seq, loff_t *pos)
499{
500 struct bpf_iter_seq_array_map_info *info = seq->private;
501 struct bpf_map *map = info->map;
502 struct bpf_array *array;
503 u32 index;
504
505 if (info->index >= map->max_entries)
506 return NULL;
507
508 if (*pos == 0)
509 ++*pos;
510 array = container_of(map, struct bpf_array, map);
511 index = info->index & array->index_mask;
512 if (info->percpu_value_buf)
513 return array->pptrs[index];
514 return array->value + array->elem_size * index;
515}
516
517static void *bpf_array_map_seq_next(struct seq_file *seq, void *v, loff_t *pos)
518{
519 struct bpf_iter_seq_array_map_info *info = seq->private;
520 struct bpf_map *map = info->map;
521 struct bpf_array *array;
522 u32 index;
523
524 ++*pos;
525 ++info->index;
526 if (info->index >= map->max_entries)
527 return NULL;
528
529 array = container_of(map, struct bpf_array, map);
530 index = info->index & array->index_mask;
531 if (info->percpu_value_buf)
532 return array->pptrs[index];
533 return array->value + array->elem_size * index;
534}
535
536static int __bpf_array_map_seq_show(struct seq_file *seq, void *v)
537{
538 struct bpf_iter_seq_array_map_info *info = seq->private;
539 struct bpf_iter__bpf_map_elem ctx = {};
540 struct bpf_map *map = info->map;
541 struct bpf_iter_meta meta;
542 struct bpf_prog *prog;
543 int off = 0, cpu = 0;
544 void __percpu **pptr;
545 u32 size;
546
547 meta.seq = seq;
548 prog = bpf_iter_get_info(&meta, v == NULL);
549 if (!prog)
550 return 0;
551
552 ctx.meta = &meta;
553 ctx.map = info->map;
554 if (v) {
555 ctx.key = &info->index;
556
557 if (!info->percpu_value_buf) {
558 ctx.value = v;
559 } else {
560 pptr = v;
561 size = round_up(map->value_size, 8);
562 for_each_possible_cpu(cpu) {
563 bpf_long_memcpy(info->percpu_value_buf + off,
564 per_cpu_ptr(pptr, cpu),
565 size);
566 off += size;
567 }
568 ctx.value = info->percpu_value_buf;
569 }
570 }
571
572 return bpf_iter_run_prog(prog, &ctx);
573}
574
575static int bpf_array_map_seq_show(struct seq_file *seq, void *v)
576{
577 return __bpf_array_map_seq_show(seq, v);
578}
579
580static void bpf_array_map_seq_stop(struct seq_file *seq, void *v)
581{
582 if (!v)
583 (void)__bpf_array_map_seq_show(seq, NULL);
584}
585
586static int bpf_iter_init_array_map(void *priv_data,
587 struct bpf_iter_aux_info *aux)
588{
589 struct bpf_iter_seq_array_map_info *seq_info = priv_data;
590 struct bpf_map *map = aux->map;
591 void *value_buf;
592 u32 buf_size;
593
594 if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
595 buf_size = round_up(map->value_size, 8) * num_possible_cpus();
596 value_buf = kmalloc(buf_size, GFP_USER | __GFP_NOWARN);
597 if (!value_buf)
598 return -ENOMEM;
599
600 seq_info->percpu_value_buf = value_buf;
601 }
602
603 seq_info->map = map;
604 return 0;
605}
606
607static void bpf_iter_fini_array_map(void *priv_data)
608{
609 struct bpf_iter_seq_array_map_info *seq_info = priv_data;
610
611 kfree(seq_info->percpu_value_buf);
612}
613
614static const struct seq_operations bpf_array_map_seq_ops = {
615 .start = bpf_array_map_seq_start,
616 .next = bpf_array_map_seq_next,
617 .stop = bpf_array_map_seq_stop,
618 .show = bpf_array_map_seq_show,
619};
620
621static const struct bpf_iter_seq_info iter_seq_info = {
622 .seq_ops = &bpf_array_map_seq_ops,
623 .init_seq_private = bpf_iter_init_array_map,
624 .fini_seq_private = bpf_iter_fini_array_map,
625 .seq_priv_size = sizeof(struct bpf_iter_seq_array_map_info),
626};
627
628static int bpf_for_each_array_elem(struct bpf_map *map, void *callback_fn,
629 void *callback_ctx, u64 flags)
630{
631 u32 i, key, num_elems = 0;
632 struct bpf_array *array;
633 bool is_percpu;
634 u64 ret = 0;
635 void *val;
636
637 if (flags != 0)
638 return -EINVAL;
639
640 is_percpu = map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY;
641 array = container_of(map, struct bpf_array, map);
642 if (is_percpu)
643 migrate_disable();
644 for (i = 0; i < map->max_entries; i++) {
645 if (is_percpu)
646 val = this_cpu_ptr(array->pptrs[i]);
647 else
648 val = array->value + array->elem_size * i;
649 num_elems++;
650 key = i;
651 ret = BPF_CAST_CALL(callback_fn)((u64)(long)map,
652 (u64)(long)&key, (u64)(long)val,
653 (u64)(long)callback_ctx, 0);
654 /* return value: 0 - continue, 1 - stop and return */
655 if (ret)
656 break;
657 }
658
659 if (is_percpu)
660 migrate_enable();
661 return num_elems;
662}
663
664static int array_map_btf_id;
665const struct bpf_map_ops array_map_ops = {
666 .map_meta_equal = array_map_meta_equal,
667 .map_alloc_check = array_map_alloc_check,
668 .map_alloc = array_map_alloc,
669 .map_free = array_map_free,
670 .map_get_next_key = array_map_get_next_key,
671 .map_lookup_elem = array_map_lookup_elem,
672 .map_update_elem = array_map_update_elem,
673 .map_delete_elem = array_map_delete_elem,
674 .map_gen_lookup = array_map_gen_lookup,
675 .map_direct_value_addr = array_map_direct_value_addr,
676 .map_direct_value_meta = array_map_direct_value_meta,
677 .map_mmap = array_map_mmap,
678 .map_seq_show_elem = array_map_seq_show_elem,
679 .map_check_btf = array_map_check_btf,
680 .map_lookup_batch = generic_map_lookup_batch,
681 .map_update_batch = generic_map_update_batch,
682 .map_set_for_each_callback_args = map_set_for_each_callback_args,
683 .map_for_each_callback = bpf_for_each_array_elem,
684 .map_btf_name = "bpf_array",
685 .map_btf_id = &array_map_btf_id,
686 .iter_seq_info = &iter_seq_info,
687};
688
689static int percpu_array_map_btf_id;
690const struct bpf_map_ops percpu_array_map_ops = {
691 .map_meta_equal = bpf_map_meta_equal,
692 .map_alloc_check = array_map_alloc_check,
693 .map_alloc = array_map_alloc,
694 .map_free = array_map_free,
695 .map_get_next_key = array_map_get_next_key,
696 .map_lookup_elem = percpu_array_map_lookup_elem,
697 .map_update_elem = array_map_update_elem,
698 .map_delete_elem = array_map_delete_elem,
699 .map_seq_show_elem = percpu_array_map_seq_show_elem,
700 .map_check_btf = array_map_check_btf,
701 .map_lookup_batch = generic_map_lookup_batch,
702 .map_update_batch = generic_map_update_batch,
703 .map_set_for_each_callback_args = map_set_for_each_callback_args,
704 .map_for_each_callback = bpf_for_each_array_elem,
705 .map_btf_name = "bpf_array",
706 .map_btf_id = &percpu_array_map_btf_id,
707 .iter_seq_info = &iter_seq_info,
708};
709
710static int fd_array_map_alloc_check(union bpf_attr *attr)
711{
712 /* only file descriptors can be stored in this type of map */
713 if (attr->value_size != sizeof(u32))
714 return -EINVAL;
715 /* Program read-only/write-only not supported for special maps yet. */
716 if (attr->map_flags & (BPF_F_RDONLY_PROG | BPF_F_WRONLY_PROG))
717 return -EINVAL;
718 return array_map_alloc_check(attr);
719}
720
721static void fd_array_map_free(struct bpf_map *map)
722{
723 struct bpf_array *array = container_of(map, struct bpf_array, map);
724 int i;
725
726 /* make sure it's empty */
727 for (i = 0; i < array->map.max_entries; i++)
728 BUG_ON(array->ptrs[i] != NULL);
729
730 bpf_map_area_free(array);
731}
732
733static void *fd_array_map_lookup_elem(struct bpf_map *map, void *key)
734{
735 return ERR_PTR(-EOPNOTSUPP);
736}
737
738/* only called from syscall */
739int bpf_fd_array_map_lookup_elem(struct bpf_map *map, void *key, u32 *value)
740{
741 void **elem, *ptr;
742 int ret = 0;
743
744 if (!map->ops->map_fd_sys_lookup_elem)
745 return -ENOTSUPP;
746
747 rcu_read_lock();
748 elem = array_map_lookup_elem(map, key);
749 if (elem && (ptr = READ_ONCE(*elem)))
750 *value = map->ops->map_fd_sys_lookup_elem(ptr);
751 else
752 ret = -ENOENT;
753 rcu_read_unlock();
754
755 return ret;
756}
757
758/* only called from syscall */
759int bpf_fd_array_map_update_elem(struct bpf_map *map, struct file *map_file,
760 void *key, void *value, u64 map_flags)
761{
762 struct bpf_array *array = container_of(map, struct bpf_array, map);
763 void *new_ptr, *old_ptr;
764 u32 index = *(u32 *)key, ufd;
765
766 if (map_flags != BPF_ANY)
767 return -EINVAL;
768
769 if (index >= array->map.max_entries)
770 return -E2BIG;
771
772 ufd = *(u32 *)value;
773 new_ptr = map->ops->map_fd_get_ptr(map, map_file, ufd);
774 if (IS_ERR(new_ptr))
775 return PTR_ERR(new_ptr);
776
777 if (map->ops->map_poke_run) {
778 mutex_lock(&array->aux->poke_mutex);
779 old_ptr = xchg(array->ptrs + index, new_ptr);
780 map->ops->map_poke_run(map, index, old_ptr, new_ptr);
781 mutex_unlock(&array->aux->poke_mutex);
782 } else {
783 old_ptr = xchg(array->ptrs + index, new_ptr);
784 }
785
786 if (old_ptr)
787 map->ops->map_fd_put_ptr(old_ptr);
788 return 0;
789}
790
791static int fd_array_map_delete_elem(struct bpf_map *map, void *key)
792{
793 struct bpf_array *array = container_of(map, struct bpf_array, map);
794 void *old_ptr;
795 u32 index = *(u32 *)key;
796
797 if (index >= array->map.max_entries)
798 return -E2BIG;
799
800 if (map->ops->map_poke_run) {
801 mutex_lock(&array->aux->poke_mutex);
802 old_ptr = xchg(array->ptrs + index, NULL);
803 map->ops->map_poke_run(map, index, old_ptr, NULL);
804 mutex_unlock(&array->aux->poke_mutex);
805 } else {
806 old_ptr = xchg(array->ptrs + index, NULL);
807 }
808
809 if (old_ptr) {
810 map->ops->map_fd_put_ptr(old_ptr);
811 return 0;
812 } else {
813 return -ENOENT;
814 }
815}
816
817static void *prog_fd_array_get_ptr(struct bpf_map *map,
818 struct file *map_file, int fd)
819{
820 struct bpf_array *array = container_of(map, struct bpf_array, map);
821 struct bpf_prog *prog = bpf_prog_get(fd);
822
823 if (IS_ERR(prog))
824 return prog;
825
826 if (!bpf_prog_array_compatible(array, prog)) {
827 bpf_prog_put(prog);
828 return ERR_PTR(-EINVAL);
829 }
830
831 return prog;
832}
833
834static void prog_fd_array_put_ptr(void *ptr)
835{
836 bpf_prog_put(ptr);
837}
838
839static u32 prog_fd_array_sys_lookup_elem(void *ptr)
840{
841 return ((struct bpf_prog *)ptr)->aux->id;
842}
843
844/* decrement refcnt of all bpf_progs that are stored in this map */
845static void bpf_fd_array_map_clear(struct bpf_map *map)
846{
847 struct bpf_array *array = container_of(map, struct bpf_array, map);
848 int i;
849
850 for (i = 0; i < array->map.max_entries; i++)
851 fd_array_map_delete_elem(map, &i);
852}
853
854static void prog_array_map_seq_show_elem(struct bpf_map *map, void *key,
855 struct seq_file *m)
856{
857 void **elem, *ptr;
858 u32 prog_id;
859
860 rcu_read_lock();
861
862 elem = array_map_lookup_elem(map, key);
863 if (elem) {
864 ptr = READ_ONCE(*elem);
865 if (ptr) {
866 seq_printf(m, "%u: ", *(u32 *)key);
867 prog_id = prog_fd_array_sys_lookup_elem(ptr);
868 btf_type_seq_show(map->btf, map->btf_value_type_id,
869 &prog_id, m);
870 seq_puts(m, "\n");
871 }
872 }
873
874 rcu_read_unlock();
875}
876
877struct prog_poke_elem {
878 struct list_head list;
879 struct bpf_prog_aux *aux;
880};
881
882static int prog_array_map_poke_track(struct bpf_map *map,
883 struct bpf_prog_aux *prog_aux)
884{
885 struct prog_poke_elem *elem;
886 struct bpf_array_aux *aux;
887 int ret = 0;
888
889 aux = container_of(map, struct bpf_array, map)->aux;
890 mutex_lock(&aux->poke_mutex);
891 list_for_each_entry(elem, &aux->poke_progs, list) {
892 if (elem->aux == prog_aux)
893 goto out;
894 }
895
896 elem = kmalloc(sizeof(*elem), GFP_KERNEL);
897 if (!elem) {
898 ret = -ENOMEM;
899 goto out;
900 }
901
902 INIT_LIST_HEAD(&elem->list);
903 /* We must track the program's aux info at this point in time
904 * since the program pointer itself may not be stable yet, see
905 * also comment in prog_array_map_poke_run().
906 */
907 elem->aux = prog_aux;
908
909 list_add_tail(&elem->list, &aux->poke_progs);
910out:
911 mutex_unlock(&aux->poke_mutex);
912 return ret;
913}
914
915static void prog_array_map_poke_untrack(struct bpf_map *map,
916 struct bpf_prog_aux *prog_aux)
917{
918 struct prog_poke_elem *elem, *tmp;
919 struct bpf_array_aux *aux;
920
921 aux = container_of(map, struct bpf_array, map)->aux;
922 mutex_lock(&aux->poke_mutex);
923 list_for_each_entry_safe(elem, tmp, &aux->poke_progs, list) {
924 if (elem->aux == prog_aux) {
925 list_del_init(&elem->list);
926 kfree(elem);
927 break;
928 }
929 }
930 mutex_unlock(&aux->poke_mutex);
931}
932
933static void prog_array_map_poke_run(struct bpf_map *map, u32 key,
934 struct bpf_prog *old,
935 struct bpf_prog *new)
936{
937 u8 *old_addr, *new_addr, *old_bypass_addr;
938 struct prog_poke_elem *elem;
939 struct bpf_array_aux *aux;
940
941 aux = container_of(map, struct bpf_array, map)->aux;
942 WARN_ON_ONCE(!mutex_is_locked(&aux->poke_mutex));
943
944 list_for_each_entry(elem, &aux->poke_progs, list) {
945 struct bpf_jit_poke_descriptor *poke;
946 int i, ret;
947
948 for (i = 0; i < elem->aux->size_poke_tab; i++) {
949 poke = &elem->aux->poke_tab[i];
950
951 /* Few things to be aware of:
952 *
953 * 1) We can only ever access aux in this context, but
954 * not aux->prog since it might not be stable yet and
955 * there could be danger of use after free otherwise.
956 * 2) Initially when we start tracking aux, the program
957 * is not JITed yet and also does not have a kallsyms
958 * entry. We skip these as poke->tailcall_target_stable
959 * is not active yet. The JIT will do the final fixup
960 * before setting it stable. The various
961 * poke->tailcall_target_stable are successively
962 * activated, so tail call updates can arrive from here
963 * while JIT is still finishing its final fixup for
964 * non-activated poke entries.
965 * 3) On program teardown, the program's kallsym entry gets
966 * removed out of RCU callback, but we can only untrack
967 * from sleepable context, therefore bpf_arch_text_poke()
968 * might not see that this is in BPF text section and
969 * bails out with -EINVAL. As these are unreachable since
970 * RCU grace period already passed, we simply skip them.
971 * 4) Also programs reaching refcount of zero while patching
972 * is in progress is okay since we're protected under
973 * poke_mutex and untrack the programs before the JIT
974 * buffer is freed. When we're still in the middle of
975 * patching and suddenly kallsyms entry of the program
976 * gets evicted, we just skip the rest which is fine due
977 * to point 3).
978 * 5) Any other error happening below from bpf_arch_text_poke()
979 * is a unexpected bug.
980 */
981 if (!READ_ONCE(poke->tailcall_target_stable))
982 continue;
983 if (poke->reason != BPF_POKE_REASON_TAIL_CALL)
984 continue;
985 if (poke->tail_call.map != map ||
986 poke->tail_call.key != key)
987 continue;
988
989 old_bypass_addr = old ? NULL : poke->bypass_addr;
990 old_addr = old ? (u8 *)old->bpf_func + poke->adj_off : NULL;
991 new_addr = new ? (u8 *)new->bpf_func + poke->adj_off : NULL;
992
993 if (new) {
994 ret = bpf_arch_text_poke(poke->tailcall_target,
995 BPF_MOD_JUMP,
996 old_addr, new_addr);
997 BUG_ON(ret < 0 && ret != -EINVAL);
998 if (!old) {
999 ret = bpf_arch_text_poke(poke->tailcall_bypass,
1000 BPF_MOD_JUMP,
1001 poke->bypass_addr,
1002 NULL);
1003 BUG_ON(ret < 0 && ret != -EINVAL);
1004 }
1005 } else {
1006 ret = bpf_arch_text_poke(poke->tailcall_bypass,
1007 BPF_MOD_JUMP,
1008 old_bypass_addr,
1009 poke->bypass_addr);
1010 BUG_ON(ret < 0 && ret != -EINVAL);
1011 /* let other CPUs finish the execution of program
1012 * so that it will not possible to expose them
1013 * to invalid nop, stack unwind, nop state
1014 */
1015 if (!ret)
1016 synchronize_rcu();
1017 ret = bpf_arch_text_poke(poke->tailcall_target,
1018 BPF_MOD_JUMP,
1019 old_addr, NULL);
1020 BUG_ON(ret < 0 && ret != -EINVAL);
1021 }
1022 }
1023 }
1024}
1025
1026static void prog_array_map_clear_deferred(struct work_struct *work)
1027{
1028 struct bpf_map *map = container_of(work, struct bpf_array_aux,
1029 work)->map;
1030 bpf_fd_array_map_clear(map);
1031 bpf_map_put(map);
1032}
1033
1034static void prog_array_map_clear(struct bpf_map *map)
1035{
1036 struct bpf_array_aux *aux = container_of(map, struct bpf_array,
1037 map)->aux;
1038 bpf_map_inc(map);
1039 schedule_work(&aux->work);
1040}
1041
1042static struct bpf_map *prog_array_map_alloc(union bpf_attr *attr)
1043{
1044 struct bpf_array_aux *aux;
1045 struct bpf_map *map;
1046
1047 aux = kzalloc(sizeof(*aux), GFP_KERNEL_ACCOUNT);
1048 if (!aux)
1049 return ERR_PTR(-ENOMEM);
1050
1051 INIT_WORK(&aux->work, prog_array_map_clear_deferred);
1052 INIT_LIST_HEAD(&aux->poke_progs);
1053 mutex_init(&aux->poke_mutex);
1054
1055 map = array_map_alloc(attr);
1056 if (IS_ERR(map)) {
1057 kfree(aux);
1058 return map;
1059 }
1060
1061 container_of(map, struct bpf_array, map)->aux = aux;
1062 aux->map = map;
1063
1064 return map;
1065}
1066
1067static void prog_array_map_free(struct bpf_map *map)
1068{
1069 struct prog_poke_elem *elem, *tmp;
1070 struct bpf_array_aux *aux;
1071
1072 aux = container_of(map, struct bpf_array, map)->aux;
1073 list_for_each_entry_safe(elem, tmp, &aux->poke_progs, list) {
1074 list_del_init(&elem->list);
1075 kfree(elem);
1076 }
1077 kfree(aux);
1078 fd_array_map_free(map);
1079}
1080
1081/* prog_array->aux->{type,jited} is a runtime binding.
1082 * Doing static check alone in the verifier is not enough.
1083 * Thus, prog_array_map cannot be used as an inner_map
1084 * and map_meta_equal is not implemented.
1085 */
1086static int prog_array_map_btf_id;
1087const struct bpf_map_ops prog_array_map_ops = {
1088 .map_alloc_check = fd_array_map_alloc_check,
1089 .map_alloc = prog_array_map_alloc,
1090 .map_free = prog_array_map_free,
1091 .map_poke_track = prog_array_map_poke_track,
1092 .map_poke_untrack = prog_array_map_poke_untrack,
1093 .map_poke_run = prog_array_map_poke_run,
1094 .map_get_next_key = array_map_get_next_key,
1095 .map_lookup_elem = fd_array_map_lookup_elem,
1096 .map_delete_elem = fd_array_map_delete_elem,
1097 .map_fd_get_ptr = prog_fd_array_get_ptr,
1098 .map_fd_put_ptr = prog_fd_array_put_ptr,
1099 .map_fd_sys_lookup_elem = prog_fd_array_sys_lookup_elem,
1100 .map_release_uref = prog_array_map_clear,
1101 .map_seq_show_elem = prog_array_map_seq_show_elem,
1102 .map_btf_name = "bpf_array",
1103 .map_btf_id = &prog_array_map_btf_id,
1104};
1105
1106static struct bpf_event_entry *bpf_event_entry_gen(struct file *perf_file,
1107 struct file *map_file)
1108{
1109 struct bpf_event_entry *ee;
1110
1111 ee = kzalloc(sizeof(*ee), GFP_ATOMIC);
1112 if (ee) {
1113 ee->event = perf_file->private_data;
1114 ee->perf_file = perf_file;
1115 ee->map_file = map_file;
1116 }
1117
1118 return ee;
1119}
1120
1121static void __bpf_event_entry_free(struct rcu_head *rcu)
1122{
1123 struct bpf_event_entry *ee;
1124
1125 ee = container_of(rcu, struct bpf_event_entry, rcu);
1126 fput(ee->perf_file);
1127 kfree(ee);
1128}
1129
1130static void bpf_event_entry_free_rcu(struct bpf_event_entry *ee)
1131{
1132 call_rcu(&ee->rcu, __bpf_event_entry_free);
1133}
1134
1135static void *perf_event_fd_array_get_ptr(struct bpf_map *map,
1136 struct file *map_file, int fd)
1137{
1138 struct bpf_event_entry *ee;
1139 struct perf_event *event;
1140 struct file *perf_file;
1141 u64 value;
1142
1143 perf_file = perf_event_get(fd);
1144 if (IS_ERR(perf_file))
1145 return perf_file;
1146
1147 ee = ERR_PTR(-EOPNOTSUPP);
1148 event = perf_file->private_data;
1149 if (perf_event_read_local(event, &value, NULL, NULL) == -EOPNOTSUPP)
1150 goto err_out;
1151
1152 ee = bpf_event_entry_gen(perf_file, map_file);
1153 if (ee)
1154 return ee;
1155 ee = ERR_PTR(-ENOMEM);
1156err_out:
1157 fput(perf_file);
1158 return ee;
1159}
1160
1161static void perf_event_fd_array_put_ptr(void *ptr)
1162{
1163 bpf_event_entry_free_rcu(ptr);
1164}
1165
1166static void perf_event_fd_array_release(struct bpf_map *map,
1167 struct file *map_file)
1168{
1169 struct bpf_array *array = container_of(map, struct bpf_array, map);
1170 struct bpf_event_entry *ee;
1171 int i;
1172
1173 if (map->map_flags & BPF_F_PRESERVE_ELEMS)
1174 return;
1175
1176 rcu_read_lock();
1177 for (i = 0; i < array->map.max_entries; i++) {
1178 ee = READ_ONCE(array->ptrs[i]);
1179 if (ee && ee->map_file == map_file)
1180 fd_array_map_delete_elem(map, &i);
1181 }
1182 rcu_read_unlock();
1183}
1184
1185static void perf_event_fd_array_map_free(struct bpf_map *map)
1186{
1187 if (map->map_flags & BPF_F_PRESERVE_ELEMS)
1188 bpf_fd_array_map_clear(map);
1189 fd_array_map_free(map);
1190}
1191
1192static int perf_event_array_map_btf_id;
1193const struct bpf_map_ops perf_event_array_map_ops = {
1194 .map_meta_equal = bpf_map_meta_equal,
1195 .map_alloc_check = fd_array_map_alloc_check,
1196 .map_alloc = array_map_alloc,
1197 .map_free = perf_event_fd_array_map_free,
1198 .map_get_next_key = array_map_get_next_key,
1199 .map_lookup_elem = fd_array_map_lookup_elem,
1200 .map_delete_elem = fd_array_map_delete_elem,
1201 .map_fd_get_ptr = perf_event_fd_array_get_ptr,
1202 .map_fd_put_ptr = perf_event_fd_array_put_ptr,
1203 .map_release = perf_event_fd_array_release,
1204 .map_check_btf = map_check_no_btf,
1205 .map_btf_name = "bpf_array",
1206 .map_btf_id = &perf_event_array_map_btf_id,
1207};
1208
1209#ifdef CONFIG_CGROUPS
1210static void *cgroup_fd_array_get_ptr(struct bpf_map *map,
1211 struct file *map_file /* not used */,
1212 int fd)
1213{
1214 return cgroup_get_from_fd(fd);
1215}
1216
1217static void cgroup_fd_array_put_ptr(void *ptr)
1218{
1219 /* cgroup_put free cgrp after a rcu grace period */
1220 cgroup_put(ptr);
1221}
1222
1223static void cgroup_fd_array_free(struct bpf_map *map)
1224{
1225 bpf_fd_array_map_clear(map);
1226 fd_array_map_free(map);
1227}
1228
1229static int cgroup_array_map_btf_id;
1230const struct bpf_map_ops cgroup_array_map_ops = {
1231 .map_meta_equal = bpf_map_meta_equal,
1232 .map_alloc_check = fd_array_map_alloc_check,
1233 .map_alloc = array_map_alloc,
1234 .map_free = cgroup_fd_array_free,
1235 .map_get_next_key = array_map_get_next_key,
1236 .map_lookup_elem = fd_array_map_lookup_elem,
1237 .map_delete_elem = fd_array_map_delete_elem,
1238 .map_fd_get_ptr = cgroup_fd_array_get_ptr,
1239 .map_fd_put_ptr = cgroup_fd_array_put_ptr,
1240 .map_check_btf = map_check_no_btf,
1241 .map_btf_name = "bpf_array",
1242 .map_btf_id = &cgroup_array_map_btf_id,
1243};
1244#endif
1245
1246static struct bpf_map *array_of_map_alloc(union bpf_attr *attr)
1247{
1248 struct bpf_map *map, *inner_map_meta;
1249
1250 inner_map_meta = bpf_map_meta_alloc(attr->inner_map_fd);
1251 if (IS_ERR(inner_map_meta))
1252 return inner_map_meta;
1253
1254 map = array_map_alloc(attr);
1255 if (IS_ERR(map)) {
1256 bpf_map_meta_free(inner_map_meta);
1257 return map;
1258 }
1259
1260 map->inner_map_meta = inner_map_meta;
1261
1262 return map;
1263}
1264
1265static void array_of_map_free(struct bpf_map *map)
1266{
1267 /* map->inner_map_meta is only accessed by syscall which
1268 * is protected by fdget/fdput.
1269 */
1270 bpf_map_meta_free(map->inner_map_meta);
1271 bpf_fd_array_map_clear(map);
1272 fd_array_map_free(map);
1273}
1274
1275static void *array_of_map_lookup_elem(struct bpf_map *map, void *key)
1276{
1277 struct bpf_map **inner_map = array_map_lookup_elem(map, key);
1278
1279 if (!inner_map)
1280 return NULL;
1281
1282 return READ_ONCE(*inner_map);
1283}
1284
1285static int array_of_map_gen_lookup(struct bpf_map *map,
1286 struct bpf_insn *insn_buf)
1287{
1288 struct bpf_array *array = container_of(map, struct bpf_array, map);
1289 u32 elem_size = round_up(map->value_size, 8);
1290 struct bpf_insn *insn = insn_buf;
1291 const int ret = BPF_REG_0;
1292 const int map_ptr = BPF_REG_1;
1293 const int index = BPF_REG_2;
1294
1295 *insn++ = BPF_ALU64_IMM(BPF_ADD, map_ptr, offsetof(struct bpf_array, value));
1296 *insn++ = BPF_LDX_MEM(BPF_W, ret, index, 0);
1297 if (!map->bypass_spec_v1) {
1298 *insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 6);
1299 *insn++ = BPF_ALU32_IMM(BPF_AND, ret, array->index_mask);
1300 } else {
1301 *insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 5);
1302 }
1303 if (is_power_of_2(elem_size))
1304 *insn++ = BPF_ALU64_IMM(BPF_LSH, ret, ilog2(elem_size));
1305 else
1306 *insn++ = BPF_ALU64_IMM(BPF_MUL, ret, elem_size);
1307 *insn++ = BPF_ALU64_REG(BPF_ADD, ret, map_ptr);
1308 *insn++ = BPF_LDX_MEM(BPF_DW, ret, ret, 0);
1309 *insn++ = BPF_JMP_IMM(BPF_JEQ, ret, 0, 1);
1310 *insn++ = BPF_JMP_IMM(BPF_JA, 0, 0, 1);
1311 *insn++ = BPF_MOV64_IMM(ret, 0);
1312
1313 return insn - insn_buf;
1314}
1315
1316static int array_of_maps_map_btf_id;
1317const struct bpf_map_ops array_of_maps_map_ops = {
1318 .map_alloc_check = fd_array_map_alloc_check,
1319 .map_alloc = array_of_map_alloc,
1320 .map_free = array_of_map_free,
1321 .map_get_next_key = array_map_get_next_key,
1322 .map_lookup_elem = array_of_map_lookup_elem,
1323 .map_delete_elem = fd_array_map_delete_elem,
1324 .map_fd_get_ptr = bpf_map_fd_get_ptr,
1325 .map_fd_put_ptr = bpf_map_fd_put_ptr,
1326 .map_fd_sys_lookup_elem = bpf_map_fd_sys_lookup_elem,
1327 .map_gen_lookup = array_of_map_gen_lookup,
1328 .map_check_btf = map_check_no_btf,
1329 .map_btf_name = "bpf_array",
1330 .map_btf_id = &array_of_maps_map_btf_id,
1331};