projects/linux·blob v6.17 · refs

1436 lines · 38.5 KiB

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 /* One exception for keyless BTF: .bss/.data/.rodata map */
534 if (btf_type_is_void(key_type)) {
535 if (map->map_type != BPF_MAP_TYPE_ARRAY ||
536 map->max_entries != 1)
537 return -EINVAL;
538
539 if (BTF_INFO_KIND(value_type->info) != BTF_KIND_DATASEC)
540 return -EINVAL;
541
542 return 0;
543 }
544
545 /*
546 * Bpf array can only take a u32 key. This check makes sure
547 * that the btf matches the attr used during map_create.
548 */
549 if (!btf_type_is_i32(key_type))
550 return -EINVAL;
551
552 return 0;
553}
554
555static int array_map_mmap(struct bpf_map *map, struct vm_area_struct *vma)
556{
557 struct bpf_array *array = container_of(map, struct bpf_array, map);
558 pgoff_t pgoff = PAGE_ALIGN(sizeof(*array)) >> PAGE_SHIFT;
559
560 if (!(map->map_flags & BPF_F_MMAPABLE))
561 return -EINVAL;
562
563 if (vma->vm_pgoff * PAGE_SIZE + (vma->vm_end - vma->vm_start) >
564 PAGE_ALIGN((u64)array->map.max_entries * array->elem_size))
565 return -EINVAL;
566
567 return remap_vmalloc_range(vma, array_map_vmalloc_addr(array),
568 vma->vm_pgoff + pgoff);
569}
570
571static bool array_map_meta_equal(const struct bpf_map *meta0,
572 const struct bpf_map *meta1)
573{
574 if (!bpf_map_meta_equal(meta0, meta1))
575 return false;
576 return meta0->map_flags & BPF_F_INNER_MAP ? true :
577 meta0->max_entries == meta1->max_entries;
578}
579
580struct bpf_iter_seq_array_map_info {
581 struct bpf_map *map;
582 void *percpu_value_buf;
583 u32 index;
584};
585
586static void *bpf_array_map_seq_start(struct seq_file *seq, loff_t *pos)
587{
588 struct bpf_iter_seq_array_map_info *info = seq->private;
589 struct bpf_map *map = info->map;
590 struct bpf_array *array;
591 u32 index;
592
593 if (info->index >= map->max_entries)
594 return NULL;
595
596 if (*pos == 0)
597 ++*pos;
598 array = container_of(map, struct bpf_array, map);
599 index = info->index & array->index_mask;
600 if (info->percpu_value_buf)
601 return (void *)(uintptr_t)array->pptrs[index];
602 return array_map_elem_ptr(array, index);
603}
604
605static void *bpf_array_map_seq_next(struct seq_file *seq, void *v, loff_t *pos)
606{
607 struct bpf_iter_seq_array_map_info *info = seq->private;
608 struct bpf_map *map = info->map;
609 struct bpf_array *array;
610 u32 index;
611
612 ++*pos;
613 ++info->index;
614 if (info->index >= map->max_entries)
615 return NULL;
616
617 array = container_of(map, struct bpf_array, map);
618 index = info->index & array->index_mask;
619 if (info->percpu_value_buf)
620 return (void *)(uintptr_t)array->pptrs[index];
621 return array_map_elem_ptr(array, index);
622}
623
624static int __bpf_array_map_seq_show(struct seq_file *seq, void *v)
625{
626 struct bpf_iter_seq_array_map_info *info = seq->private;
627 struct bpf_iter__bpf_map_elem ctx = {};
628 struct bpf_map *map = info->map;
629 struct bpf_array *array = container_of(map, struct bpf_array, map);
630 struct bpf_iter_meta meta;
631 struct bpf_prog *prog;
632 int off = 0, cpu = 0;
633 void __percpu *pptr;
634 u32 size;
635
636 meta.seq = seq;
637 prog = bpf_iter_get_info(&meta, v == NULL);
638 if (!prog)
639 return 0;
640
641 ctx.meta = &meta;
642 ctx.map = info->map;
643 if (v) {
644 ctx.key = &info->index;
645
646 if (!info->percpu_value_buf) {
647 ctx.value = v;
648 } else {
649 pptr = (void __percpu *)(uintptr_t)v;
650 size = array->elem_size;
651 for_each_possible_cpu(cpu) {
652 copy_map_value_long(map, info->percpu_value_buf + off,
653 per_cpu_ptr(pptr, cpu));
654 check_and_init_map_value(map, info->percpu_value_buf + off);
655 off += size;
656 }
657 ctx.value = info->percpu_value_buf;
658 }
659 }
660
661 return bpf_iter_run_prog(prog, &ctx);
662}
663
664static int bpf_array_map_seq_show(struct seq_file *seq, void *v)
665{
666 return __bpf_array_map_seq_show(seq, v);
667}
668
669static void bpf_array_map_seq_stop(struct seq_file *seq, void *v)
670{
671 if (!v)
672 (void)__bpf_array_map_seq_show(seq, NULL);
673}
674
675static int bpf_iter_init_array_map(void *priv_data,
676 struct bpf_iter_aux_info *aux)
677{
678 struct bpf_iter_seq_array_map_info *seq_info = priv_data;
679 struct bpf_map *map = aux->map;
680 struct bpf_array *array = container_of(map, struct bpf_array, map);
681 void *value_buf;
682 u32 buf_size;
683
684 if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
685 buf_size = array->elem_size * num_possible_cpus();
686 value_buf = kmalloc(buf_size, GFP_USER | __GFP_NOWARN);
687 if (!value_buf)
688 return -ENOMEM;
689
690 seq_info->percpu_value_buf = value_buf;
691 }
692
693 /* bpf_iter_attach_map() acquires a map uref, and the uref may be
694 * released before or in the middle of iterating map elements, so
695 * acquire an extra map uref for iterator.
696 */
697 bpf_map_inc_with_uref(map);
698 seq_info->map = map;
699 return 0;
700}
701
702static void bpf_iter_fini_array_map(void *priv_data)
703{
704 struct bpf_iter_seq_array_map_info *seq_info = priv_data;
705
706 bpf_map_put_with_uref(seq_info->map);
707 kfree(seq_info->percpu_value_buf);
708}
709
710static const struct seq_operations bpf_array_map_seq_ops = {
711 .start = bpf_array_map_seq_start,
712 .next = bpf_array_map_seq_next,
713 .stop = bpf_array_map_seq_stop,
714 .show = bpf_array_map_seq_show,
715};
716
717static const struct bpf_iter_seq_info iter_seq_info = {
718 .seq_ops = &bpf_array_map_seq_ops,
719 .init_seq_private = bpf_iter_init_array_map,
720 .fini_seq_private = bpf_iter_fini_array_map,
721 .seq_priv_size = sizeof(struct bpf_iter_seq_array_map_info),
722};
723
724static long bpf_for_each_array_elem(struct bpf_map *map, bpf_callback_t callback_fn,
725 void *callback_ctx, u64 flags)
726{
727 u32 i, key, num_elems = 0;
728 struct bpf_array *array;
729 bool is_percpu;
730 u64 ret = 0;
731 void *val;
732
733 cant_migrate();
734
735 if (flags != 0)
736 return -EINVAL;
737
738 is_percpu = map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY;
739 array = container_of(map, struct bpf_array, map);
740 for (i = 0; i < map->max_entries; i++) {
741 if (is_percpu)
742 val = this_cpu_ptr(array->pptrs[i]);
743 else
744 val = array_map_elem_ptr(array, i);
745 num_elems++;
746 key = i;
747 ret = callback_fn((u64)(long)map, (u64)(long)&key,
748 (u64)(long)val, (u64)(long)callback_ctx, 0);
749 /* return value: 0 - continue, 1 - stop and return */
750 if (ret)
751 break;
752 }
753
754 return num_elems;
755}
756
757static u64 array_map_mem_usage(const struct bpf_map *map)
758{
759 struct bpf_array *array = container_of(map, struct bpf_array, map);
760 bool percpu = map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY;
761 u32 elem_size = array->elem_size;
762 u64 entries = map->max_entries;
763 u64 usage = sizeof(*array);
764
765 if (percpu) {
766 usage += entries * sizeof(void *);
767 usage += entries * elem_size * num_possible_cpus();
768 } else {
769 if (map->map_flags & BPF_F_MMAPABLE) {
770 usage = PAGE_ALIGN(usage);
771 usage += PAGE_ALIGN(entries * elem_size);
772 } else {
773 usage += entries * elem_size;
774 }
775 }
776 return usage;
777}
778
779BTF_ID_LIST_SINGLE(array_map_btf_ids, struct, bpf_array)
780const struct bpf_map_ops array_map_ops = {
781 .map_meta_equal = array_map_meta_equal,
782 .map_alloc_check = array_map_alloc_check,
783 .map_alloc = array_map_alloc,
784 .map_free = array_map_free,
785 .map_get_next_key = array_map_get_next_key,
786 .map_release_uref = array_map_free_timers_wq,
787 .map_lookup_elem = array_map_lookup_elem,
788 .map_update_elem = array_map_update_elem,
789 .map_delete_elem = array_map_delete_elem,
790 .map_gen_lookup = array_map_gen_lookup,
791 .map_direct_value_addr = array_map_direct_value_addr,
792 .map_direct_value_meta = array_map_direct_value_meta,
793 .map_mmap = array_map_mmap,
794 .map_seq_show_elem = array_map_seq_show_elem,
795 .map_check_btf = array_map_check_btf,
796 .map_lookup_batch = generic_map_lookup_batch,
797 .map_update_batch = generic_map_update_batch,
798 .map_set_for_each_callback_args = map_set_for_each_callback_args,
799 .map_for_each_callback = bpf_for_each_array_elem,
800 .map_mem_usage = array_map_mem_usage,
801 .map_btf_id = &array_map_btf_ids[0],
802 .iter_seq_info = &iter_seq_info,
803};
804
805const struct bpf_map_ops percpu_array_map_ops = {
806 .map_meta_equal = bpf_map_meta_equal,
807 .map_alloc_check = array_map_alloc_check,
808 .map_alloc = array_map_alloc,
809 .map_free = array_map_free,
810 .map_get_next_key = array_map_get_next_key,
811 .map_lookup_elem = percpu_array_map_lookup_elem,
812 .map_gen_lookup = percpu_array_map_gen_lookup,
813 .map_update_elem = array_map_update_elem,
814 .map_delete_elem = array_map_delete_elem,
815 .map_lookup_percpu_elem = percpu_array_map_lookup_percpu_elem,
816 .map_seq_show_elem = percpu_array_map_seq_show_elem,
817 .map_check_btf = array_map_check_btf,
818 .map_lookup_batch = generic_map_lookup_batch,
819 .map_update_batch = generic_map_update_batch,
820 .map_set_for_each_callback_args = map_set_for_each_callback_args,
821 .map_for_each_callback = bpf_for_each_array_elem,
822 .map_mem_usage = array_map_mem_usage,
823 .map_btf_id = &array_map_btf_ids[0],
824 .iter_seq_info = &iter_seq_info,
825};
826
827static int fd_array_map_alloc_check(union bpf_attr *attr)
828{
829 /* only file descriptors can be stored in this type of map */
830 if (attr->value_size != sizeof(u32))
831 return -EINVAL;
832 /* Program read-only/write-only not supported for special maps yet. */
833 if (attr->map_flags & (BPF_F_RDONLY_PROG | BPF_F_WRONLY_PROG))
834 return -EINVAL;
835 return array_map_alloc_check(attr);
836}
837
838static void fd_array_map_free(struct bpf_map *map)
839{
840 struct bpf_array *array = container_of(map, struct bpf_array, map);
841 int i;
842
843 /* make sure it's empty */
844 for (i = 0; i < array->map.max_entries; i++)
845 BUG_ON(array->ptrs[i] != NULL);
846
847 bpf_map_area_free(array);
848}
849
850static void *fd_array_map_lookup_elem(struct bpf_map *map, void *key)
851{
852 return ERR_PTR(-EOPNOTSUPP);
853}
854
855/* only called from syscall */
856int bpf_fd_array_map_lookup_elem(struct bpf_map *map, void *key, u32 *value)
857{
858 void **elem, *ptr;
859 int ret = 0;
860
861 if (!map->ops->map_fd_sys_lookup_elem)
862 return -ENOTSUPP;
863
864 rcu_read_lock();
865 elem = array_map_lookup_elem(map, key);
866 if (elem && (ptr = READ_ONCE(*elem)))
867 *value = map->ops->map_fd_sys_lookup_elem(ptr);
868 else
869 ret = -ENOENT;
870 rcu_read_unlock();
871
872 return ret;
873}
874
875/* only called from syscall */
876int bpf_fd_array_map_update_elem(struct bpf_map *map, struct file *map_file,
877 void *key, void *value, u64 map_flags)
878{
879 struct bpf_array *array = container_of(map, struct bpf_array, map);
880 void *new_ptr, *old_ptr;
881 u32 index = *(u32 *)key, ufd;
882
883 if (map_flags != BPF_ANY)
884 return -EINVAL;
885
886 if (index >= array->map.max_entries)
887 return -E2BIG;
888
889 ufd = *(u32 *)value;
890 new_ptr = map->ops->map_fd_get_ptr(map, map_file, ufd);
891 if (IS_ERR(new_ptr))
892 return PTR_ERR(new_ptr);
893
894 if (map->ops->map_poke_run) {
895 mutex_lock(&array->aux->poke_mutex);
896 old_ptr = xchg(array->ptrs + index, new_ptr);
897 map->ops->map_poke_run(map, index, old_ptr, new_ptr);
898 mutex_unlock(&array->aux->poke_mutex);
899 } else {
900 old_ptr = xchg(array->ptrs + index, new_ptr);
901 }
902
903 if (old_ptr)
904 map->ops->map_fd_put_ptr(map, old_ptr, true);
905 return 0;
906}
907
908static long __fd_array_map_delete_elem(struct bpf_map *map, void *key, bool need_defer)
909{
910 struct bpf_array *array = container_of(map, struct bpf_array, map);
911 void *old_ptr;
912 u32 index = *(u32 *)key;
913
914 if (index >= array->map.max_entries)
915 return -E2BIG;
916
917 if (map->ops->map_poke_run) {
918 mutex_lock(&array->aux->poke_mutex);
919 old_ptr = xchg(array->ptrs + index, NULL);
920 map->ops->map_poke_run(map, index, old_ptr, NULL);
921 mutex_unlock(&array->aux->poke_mutex);
922 } else {
923 old_ptr = xchg(array->ptrs + index, NULL);
924 }
925
926 if (old_ptr) {
927 map->ops->map_fd_put_ptr(map, old_ptr, need_defer);
928 return 0;
929 } else {
930 return -ENOENT;
931 }
932}
933
934static long fd_array_map_delete_elem(struct bpf_map *map, void *key)
935{
936 return __fd_array_map_delete_elem(map, key, true);
937}
938
939static void *prog_fd_array_get_ptr(struct bpf_map *map,
940 struct file *map_file, int fd)
941{
942 struct bpf_prog *prog = bpf_prog_get(fd);
943 bool is_extended;
944
945 if (IS_ERR(prog))
946 return prog;
947
948 if (prog->type == BPF_PROG_TYPE_EXT ||
949 !bpf_prog_map_compatible(map, prog)) {
950 bpf_prog_put(prog);
951 return ERR_PTR(-EINVAL);
952 }
953
954 mutex_lock(&prog->aux->ext_mutex);
955 is_extended = prog->aux->is_extended;
956 if (!is_extended)
957 prog->aux->prog_array_member_cnt++;
958 mutex_unlock(&prog->aux->ext_mutex);
959 if (is_extended) {
960 /* Extended prog can not be tail callee. It's to prevent a
961 * potential infinite loop like:
962 * tail callee prog entry -> tail callee prog subprog ->
963 * freplace prog entry --tailcall-> tail callee prog entry.
964 */
965 bpf_prog_put(prog);
966 return ERR_PTR(-EBUSY);
967 }
968
969 return prog;
970}
971
972static void prog_fd_array_put_ptr(struct bpf_map *map, void *ptr, bool need_defer)
973{
974 struct bpf_prog *prog = ptr;
975
976 mutex_lock(&prog->aux->ext_mutex);
977 prog->aux->prog_array_member_cnt--;
978 mutex_unlock(&prog->aux->ext_mutex);
979 /* bpf_prog is freed after one RCU or tasks trace grace period */
980 bpf_prog_put(prog);
981}
982
983static u32 prog_fd_array_sys_lookup_elem(void *ptr)
984{
985 return ((struct bpf_prog *)ptr)->aux->id;
986}
987
988/* decrement refcnt of all bpf_progs that are stored in this map */
989static void bpf_fd_array_map_clear(struct bpf_map *map, bool need_defer)
990{
991 struct bpf_array *array = container_of(map, struct bpf_array, map);
992 int i;
993
994 for (i = 0; i < array->map.max_entries; i++)
995 __fd_array_map_delete_elem(map, &i, need_defer);
996}
997
998static void prog_array_map_seq_show_elem(struct bpf_map *map, void *key,
999 struct seq_file *m)
1000{
1001 void **elem, *ptr;
1002 u32 prog_id;
1003
1004 rcu_read_lock();
1005
1006 elem = array_map_lookup_elem(map, key);
1007 if (elem) {
1008 ptr = READ_ONCE(*elem);
1009 if (ptr) {
1010 seq_printf(m, "%u: ", *(u32 *)key);
1011 prog_id = prog_fd_array_sys_lookup_elem(ptr);
1012 btf_type_seq_show(map->btf, map->btf_value_type_id,
1013 &prog_id, m);
1014 seq_putc(m, '\n');
1015 }
1016 }
1017
1018 rcu_read_unlock();
1019}
1020
1021struct prog_poke_elem {
1022 struct list_head list;
1023 struct bpf_prog_aux *aux;
1024};
1025
1026static int prog_array_map_poke_track(struct bpf_map *map,
1027 struct bpf_prog_aux *prog_aux)
1028{
1029 struct prog_poke_elem *elem;
1030 struct bpf_array_aux *aux;
1031 int ret = 0;
1032
1033 aux = container_of(map, struct bpf_array, map)->aux;
1034 mutex_lock(&aux->poke_mutex);
1035 list_for_each_entry(elem, &aux->poke_progs, list) {
1036 if (elem->aux == prog_aux)
1037 goto out;
1038 }
1039
1040 elem = kmalloc(sizeof(*elem), GFP_KERNEL);
1041 if (!elem) {
1042 ret = -ENOMEM;
1043 goto out;
1044 }
1045
1046 INIT_LIST_HEAD(&elem->list);
1047 /* We must track the program's aux info at this point in time
1048 * since the program pointer itself may not be stable yet, see
1049 * also comment in prog_array_map_poke_run().
1050 */
1051 elem->aux = prog_aux;
1052
1053 list_add_tail(&elem->list, &aux->poke_progs);
1054out:
1055 mutex_unlock(&aux->poke_mutex);
1056 return ret;
1057}
1058
1059static void prog_array_map_poke_untrack(struct bpf_map *map,
1060 struct bpf_prog_aux *prog_aux)
1061{
1062 struct prog_poke_elem *elem, *tmp;
1063 struct bpf_array_aux *aux;
1064
1065 aux = container_of(map, struct bpf_array, map)->aux;
1066 mutex_lock(&aux->poke_mutex);
1067 list_for_each_entry_safe(elem, tmp, &aux->poke_progs, list) {
1068 if (elem->aux == prog_aux) {
1069 list_del_init(&elem->list);
1070 kfree(elem);
1071 break;
1072 }
1073 }
1074 mutex_unlock(&aux->poke_mutex);
1075}
1076
1077void __weak bpf_arch_poke_desc_update(struct bpf_jit_poke_descriptor *poke,
1078 struct bpf_prog *new, struct bpf_prog *old)
1079{
1080 WARN_ON_ONCE(1);
1081}
1082
1083static void prog_array_map_poke_run(struct bpf_map *map, u32 key,
1084 struct bpf_prog *old,
1085 struct bpf_prog *new)
1086{
1087 struct prog_poke_elem *elem;
1088 struct bpf_array_aux *aux;
1089
1090 aux = container_of(map, struct bpf_array, map)->aux;
1091 WARN_ON_ONCE(!mutex_is_locked(&aux->poke_mutex));
1092
1093 list_for_each_entry(elem, &aux->poke_progs, list) {
1094 struct bpf_jit_poke_descriptor *poke;
1095 int i;
1096
1097 for (i = 0; i < elem->aux->size_poke_tab; i++) {
1098 poke = &elem->aux->poke_tab[i];
1099
1100 /* Few things to be aware of:
1101 *
1102 * 1) We can only ever access aux in this context, but
1103 * not aux->prog since it might not be stable yet and
1104 * there could be danger of use after free otherwise.
1105 * 2) Initially when we start tracking aux, the program
1106 * is not JITed yet and also does not have a kallsyms
1107 * entry. We skip these as poke->tailcall_target_stable
1108 * is not active yet. The JIT will do the final fixup
1109 * before setting it stable. The various
1110 * poke->tailcall_target_stable are successively
1111 * activated, so tail call updates can arrive from here
1112 * while JIT is still finishing its final fixup for
1113 * non-activated poke entries.
1114 * 3) Also programs reaching refcount of zero while patching
1115 * is in progress is okay since we're protected under
1116 * poke_mutex and untrack the programs before the JIT
1117 * buffer is freed.
1118 */
1119 if (!READ_ONCE(poke->tailcall_target_stable))
1120 continue;
1121 if (poke->reason != BPF_POKE_REASON_TAIL_CALL)
1122 continue;
1123 if (poke->tail_call.map != map ||
1124 poke->tail_call.key != key)
1125 continue;
1126
1127 bpf_arch_poke_desc_update(poke, new, old);
1128 }
1129 }
1130}
1131
1132static void prog_array_map_clear_deferred(struct work_struct *work)
1133{
1134 struct bpf_map *map = container_of(work, struct bpf_array_aux,
1135 work)->map;
1136 bpf_fd_array_map_clear(map, true);
1137 bpf_map_put(map);
1138}
1139
1140static void prog_array_map_clear(struct bpf_map *map)
1141{
1142 struct bpf_array_aux *aux = container_of(map, struct bpf_array,
1143 map)->aux;
1144 bpf_map_inc(map);
1145 schedule_work(&aux->work);
1146}
1147
1148static struct bpf_map *prog_array_map_alloc(union bpf_attr *attr)
1149{
1150 struct bpf_array_aux *aux;
1151 struct bpf_map *map;
1152
1153 aux = kzalloc(sizeof(*aux), GFP_KERNEL_ACCOUNT);
1154 if (!aux)
1155 return ERR_PTR(-ENOMEM);
1156
1157 INIT_WORK(&aux->work, prog_array_map_clear_deferred);
1158 INIT_LIST_HEAD(&aux->poke_progs);
1159 mutex_init(&aux->poke_mutex);
1160
1161 map = array_map_alloc(attr);
1162 if (IS_ERR(map)) {
1163 kfree(aux);
1164 return map;
1165 }
1166
1167 container_of(map, struct bpf_array, map)->aux = aux;
1168 aux->map = map;
1169
1170 return map;
1171}
1172
1173static void prog_array_map_free(struct bpf_map *map)
1174{
1175 struct prog_poke_elem *elem, *tmp;
1176 struct bpf_array_aux *aux;
1177
1178 aux = container_of(map, struct bpf_array, map)->aux;
1179 list_for_each_entry_safe(elem, tmp, &aux->poke_progs, list) {
1180 list_del_init(&elem->list);
1181 kfree(elem);
1182 }
1183 kfree(aux);
1184 fd_array_map_free(map);
1185}
1186
1187/* prog_array->aux->{type,jited} is a runtime binding.
1188 * Doing static check alone in the verifier is not enough.
1189 * Thus, prog_array_map cannot be used as an inner_map
1190 * and map_meta_equal is not implemented.
1191 */
1192const struct bpf_map_ops prog_array_map_ops = {
1193 .map_alloc_check = fd_array_map_alloc_check,
1194 .map_alloc = prog_array_map_alloc,
1195 .map_free = prog_array_map_free,
1196 .map_poke_track = prog_array_map_poke_track,
1197 .map_poke_untrack = prog_array_map_poke_untrack,
1198 .map_poke_run = prog_array_map_poke_run,
1199 .map_get_next_key = array_map_get_next_key,
1200 .map_lookup_elem = fd_array_map_lookup_elem,
1201 .map_delete_elem = fd_array_map_delete_elem,
1202 .map_fd_get_ptr = prog_fd_array_get_ptr,
1203 .map_fd_put_ptr = prog_fd_array_put_ptr,
1204 .map_fd_sys_lookup_elem = prog_fd_array_sys_lookup_elem,
1205 .map_release_uref = prog_array_map_clear,
1206 .map_seq_show_elem = prog_array_map_seq_show_elem,
1207 .map_mem_usage = array_map_mem_usage,
1208 .map_btf_id = &array_map_btf_ids[0],
1209};
1210
1211static struct bpf_event_entry *bpf_event_entry_gen(struct file *perf_file,
1212 struct file *map_file)
1213{
1214 struct bpf_event_entry *ee;
1215
1216 ee = kzalloc(sizeof(*ee), GFP_KERNEL);
1217 if (ee) {
1218 ee->event = perf_file->private_data;
1219 ee->perf_file = perf_file;
1220 ee->map_file = map_file;
1221 }
1222
1223 return ee;
1224}
1225
1226static void __bpf_event_entry_free(struct rcu_head *rcu)
1227{
1228 struct bpf_event_entry *ee;
1229
1230 ee = container_of(rcu, struct bpf_event_entry, rcu);
1231 fput(ee->perf_file);
1232 kfree(ee);
1233}
1234
1235static void bpf_event_entry_free_rcu(struct bpf_event_entry *ee)
1236{
1237 call_rcu(&ee->rcu, __bpf_event_entry_free);
1238}
1239
1240static void *perf_event_fd_array_get_ptr(struct bpf_map *map,
1241 struct file *map_file, int fd)
1242{
1243 struct bpf_event_entry *ee;
1244 struct perf_event *event;
1245 struct file *perf_file;
1246 u64 value;
1247
1248 perf_file = perf_event_get(fd);
1249 if (IS_ERR(perf_file))
1250 return perf_file;
1251
1252 ee = ERR_PTR(-EOPNOTSUPP);
1253 event = perf_file->private_data;
1254 if (perf_event_read_local(event, &value, NULL, NULL) == -EOPNOTSUPP)
1255 goto err_out;
1256
1257 ee = bpf_event_entry_gen(perf_file, map_file);
1258 if (ee)
1259 return ee;
1260 ee = ERR_PTR(-ENOMEM);
1261err_out:
1262 fput(perf_file);
1263 return ee;
1264}
1265
1266static void perf_event_fd_array_put_ptr(struct bpf_map *map, void *ptr, bool need_defer)
1267{
1268 /* bpf_perf_event is freed after one RCU grace period */
1269 bpf_event_entry_free_rcu(ptr);
1270}
1271
1272static void perf_event_fd_array_release(struct bpf_map *map,
1273 struct file *map_file)
1274{
1275 struct bpf_array *array = container_of(map, struct bpf_array, map);
1276 struct bpf_event_entry *ee;
1277 int i;
1278
1279 if (map->map_flags & BPF_F_PRESERVE_ELEMS)
1280 return;
1281
1282 rcu_read_lock();
1283 for (i = 0; i < array->map.max_entries; i++) {
1284 ee = READ_ONCE(array->ptrs[i]);
1285 if (ee && ee->map_file == map_file)
1286 __fd_array_map_delete_elem(map, &i, true);
1287 }
1288 rcu_read_unlock();
1289}
1290
1291static void perf_event_fd_array_map_free(struct bpf_map *map)
1292{
1293 if (map->map_flags & BPF_F_PRESERVE_ELEMS)
1294 bpf_fd_array_map_clear(map, false);
1295 fd_array_map_free(map);
1296}
1297
1298const struct bpf_map_ops perf_event_array_map_ops = {
1299 .map_meta_equal = bpf_map_meta_equal,
1300 .map_alloc_check = fd_array_map_alloc_check,
1301 .map_alloc = array_map_alloc,
1302 .map_free = perf_event_fd_array_map_free,
1303 .map_get_next_key = array_map_get_next_key,
1304 .map_lookup_elem = fd_array_map_lookup_elem,
1305 .map_delete_elem = fd_array_map_delete_elem,
1306 .map_fd_get_ptr = perf_event_fd_array_get_ptr,
1307 .map_fd_put_ptr = perf_event_fd_array_put_ptr,
1308 .map_release = perf_event_fd_array_release,
1309 .map_check_btf = map_check_no_btf,
1310 .map_mem_usage = array_map_mem_usage,
1311 .map_btf_id = &array_map_btf_ids[0],
1312};
1313
1314#ifdef CONFIG_CGROUPS
1315static void *cgroup_fd_array_get_ptr(struct bpf_map *map,
1316 struct file *map_file /* not used */,
1317 int fd)
1318{
1319 return cgroup_get_from_fd(fd);
1320}
1321
1322static void cgroup_fd_array_put_ptr(struct bpf_map *map, void *ptr, bool need_defer)
1323{
1324 /* cgroup_put free cgrp after a rcu grace period */
1325 cgroup_put(ptr);
1326}
1327
1328static void cgroup_fd_array_free(struct bpf_map *map)
1329{
1330 bpf_fd_array_map_clear(map, false);
1331 fd_array_map_free(map);
1332}
1333
1334const struct bpf_map_ops cgroup_array_map_ops = {
1335 .map_meta_equal = bpf_map_meta_equal,
1336 .map_alloc_check = fd_array_map_alloc_check,
1337 .map_alloc = array_map_alloc,
1338 .map_free = cgroup_fd_array_free,
1339 .map_get_next_key = array_map_get_next_key,
1340 .map_lookup_elem = fd_array_map_lookup_elem,
1341 .map_delete_elem = fd_array_map_delete_elem,
1342 .map_fd_get_ptr = cgroup_fd_array_get_ptr,
1343 .map_fd_put_ptr = cgroup_fd_array_put_ptr,
1344 .map_check_btf = map_check_no_btf,
1345 .map_mem_usage = array_map_mem_usage,
1346 .map_btf_id = &array_map_btf_ids[0],
1347};
1348#endif
1349
1350static struct bpf_map *array_of_map_alloc(union bpf_attr *attr)
1351{
1352 struct bpf_map *map, *inner_map_meta;
1353
1354 inner_map_meta = bpf_map_meta_alloc(attr->inner_map_fd);
1355 if (IS_ERR(inner_map_meta))
1356 return inner_map_meta;
1357
1358 map = array_map_alloc(attr);
1359 if (IS_ERR(map)) {
1360 bpf_map_meta_free(inner_map_meta);
1361 return map;
1362 }
1363
1364 map->inner_map_meta = inner_map_meta;
1365
1366 return map;
1367}
1368
1369static void array_of_map_free(struct bpf_map *map)
1370{
1371 /* map->inner_map_meta is only accessed by syscall which
1372 * is protected by fdget/fdput.
1373 */
1374 bpf_map_meta_free(map->inner_map_meta);
1375 bpf_fd_array_map_clear(map, false);
1376 fd_array_map_free(map);
1377}
1378
1379static void *array_of_map_lookup_elem(struct bpf_map *map, void *key)
1380{
1381 struct bpf_map **inner_map = array_map_lookup_elem(map, key);
1382
1383 if (!inner_map)
1384 return NULL;
1385
1386 return READ_ONCE(*inner_map);
1387}
1388
1389static int array_of_map_gen_lookup(struct bpf_map *map,
1390 struct bpf_insn *insn_buf)
1391{
1392 struct bpf_array *array = container_of(map, struct bpf_array, map);
1393 u32 elem_size = array->elem_size;
1394 struct bpf_insn *insn = insn_buf;
1395 const int ret = BPF_REG_0;
1396 const int map_ptr = BPF_REG_1;
1397 const int index = BPF_REG_2;
1398
1399 *insn++ = BPF_ALU64_IMM(BPF_ADD, map_ptr, offsetof(struct bpf_array, value));
1400 *insn++ = BPF_LDX_MEM(BPF_W, ret, index, 0);
1401 if (!map->bypass_spec_v1) {
1402 *insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 6);
1403 *insn++ = BPF_ALU32_IMM(BPF_AND, ret, array->index_mask);
1404 } else {
1405 *insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 5);
1406 }
1407 if (is_power_of_2(elem_size))
1408 *insn++ = BPF_ALU64_IMM(BPF_LSH, ret, ilog2(elem_size));
1409 else
1410 *insn++ = BPF_ALU64_IMM(BPF_MUL, ret, elem_size);
1411 *insn++ = BPF_ALU64_REG(BPF_ADD, ret, map_ptr);
1412 *insn++ = BPF_LDX_MEM(BPF_DW, ret, ret, 0);
1413 *insn++ = BPF_JMP_IMM(BPF_JEQ, ret, 0, 1);
1414 *insn++ = BPF_JMP_IMM(BPF_JA, 0, 0, 1);
1415 *insn++ = BPF_MOV64_IMM(ret, 0);
1416
1417 return insn - insn_buf;
1418}
1419
1420const struct bpf_map_ops array_of_maps_map_ops = {
1421 .map_alloc_check = fd_array_map_alloc_check,
1422 .map_alloc = array_of_map_alloc,
1423 .map_free = array_of_map_free,
1424 .map_get_next_key = array_map_get_next_key,
1425 .map_lookup_elem = array_of_map_lookup_elem,
1426 .map_delete_elem = fd_array_map_delete_elem,
1427 .map_fd_get_ptr = bpf_map_fd_get_ptr,
1428 .map_fd_put_ptr = bpf_map_fd_put_ptr,
1429 .map_fd_sys_lookup_elem = bpf_map_fd_sys_lookup_elem,
1430 .map_gen_lookup = array_of_map_gen_lookup,
1431 .map_lookup_batch = generic_map_lookup_batch,
1432 .map_update_batch = generic_map_update_batch,
1433 .map_check_btf = map_check_no_btf,
1434 .map_mem_usage = array_map_mem_usage,
1435 .map_btf_id = &array_map_btf_ids[0],
1436};