projects/linux·blob v7.2-rc2 · refs

1460 lines · 38.9 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#include <crypto/sha2.h>
16
17#include "map_in_map.h"
18
19#define ARRAY_CREATE_FLAG_MASK \
20 (BPF_F_NUMA_NODE | BPF_F_MMAPABLE | BPF_F_ACCESS_MASK | \
21 BPF_F_PRESERVE_ELEMS | BPF_F_INNER_MAP)
22
23static void bpf_array_free_percpu(struct bpf_array *array)
24{
25 int i;
26
27 for (i = 0; i < array->map.max_entries; i++) {
28 free_percpu(array->pptrs[i]);
29 cond_resched();
30 }
31}
32
33static int bpf_array_alloc_percpu(struct bpf_array *array)
34{
35 void __percpu *ptr;
36 int i;
37
38 for (i = 0; i < array->map.max_entries; i++) {
39 ptr = bpf_map_alloc_percpu(&array->map, array->elem_size, 8,
40 GFP_USER | __GFP_NOWARN);
41 if (!ptr) {
42 bpf_array_free_percpu(array);
43 return -ENOMEM;
44 }
45 array->pptrs[i] = ptr;
46 cond_resched();
47 }
48
49 return 0;
50}
51
52/* Called from syscall */
53int array_map_alloc_check(union bpf_attr *attr)
54{
55 bool percpu = attr->map_type == BPF_MAP_TYPE_PERCPU_ARRAY;
56 int numa_node = bpf_map_attr_numa_node(attr);
57
58 /* check sanity of attributes */
59 if (attr->max_entries == 0 || attr->key_size != 4 ||
60 attr->value_size == 0 ||
61 attr->map_flags & ~ARRAY_CREATE_FLAG_MASK ||
62 !bpf_map_flags_access_ok(attr->map_flags) ||
63 (percpu && numa_node != NUMA_NO_NODE))
64 return -EINVAL;
65
66 if (attr->map_type != BPF_MAP_TYPE_ARRAY &&
67 attr->map_flags & (BPF_F_MMAPABLE | BPF_F_INNER_MAP))
68 return -EINVAL;
69
70 if (attr->map_type != BPF_MAP_TYPE_PERF_EVENT_ARRAY &&
71 attr->map_flags & BPF_F_PRESERVE_ELEMS)
72 return -EINVAL;
73
74 /* avoid overflow on round_up(map->value_size) */
75 if (attr->value_size > INT_MAX)
76 return -E2BIG;
77 /* percpu map value size is bound by PCPU_MIN_UNIT_SIZE */
78 if (percpu && round_up(attr->value_size, 8) > PCPU_MIN_UNIT_SIZE)
79 return -E2BIG;
80
81 return 0;
82}
83
84static struct bpf_map *array_map_alloc(union bpf_attr *attr)
85{
86 bool percpu = attr->map_type == BPF_MAP_TYPE_PERCPU_ARRAY;
87 int numa_node = bpf_map_attr_numa_node(attr);
88 u32 elem_size, index_mask, max_entries;
89 bool bypass_spec_v1 = bpf_bypass_spec_v1(NULL);
90 u64 array_size, mask64;
91 struct bpf_array *array;
92
93 elem_size = round_up(attr->value_size, 8);
94
95 max_entries = attr->max_entries;
96
97 /* On 32 bit archs roundup_pow_of_two() with max_entries that has
98 * upper most bit set in u32 space is undefined behavior due to
99 * resulting 1U << 32, so do it manually here in u64 space.
100 */
101 mask64 = fls_long(max_entries - 1);
102 mask64 = 1ULL << mask64;
103 mask64 -= 1;
104
105 index_mask = mask64;
106 if (!bypass_spec_v1) {
107 /* round up array size to nearest power of 2,
108 * since cpu will speculate within index_mask limits
109 */
110 max_entries = index_mask + 1;
111 /* Check for overflows. */
112 if (max_entries < attr->max_entries)
113 return ERR_PTR(-E2BIG);
114 }
115
116 array_size = sizeof(*array);
117 if (percpu) {
118 array_size += (u64) max_entries * sizeof(void *);
119 } else {
120 /* rely on vmalloc() to return page-aligned memory and
121 * ensure array->value is exactly page-aligned
122 */
123 if (attr->map_flags & BPF_F_MMAPABLE) {
124 array_size = PAGE_ALIGN(array_size);
125 array_size += PAGE_ALIGN((u64) max_entries * elem_size);
126 } else {
127 array_size += (u64) max_entries * elem_size;
128 }
129 }
130
131 /* allocate all map elements and zero-initialize them */
132 if (attr->map_flags & BPF_F_MMAPABLE) {
133 void *data;
134
135 /* kmalloc'ed memory can't be mmap'ed, use explicit vmalloc */
136 data = bpf_map_area_mmapable_alloc(array_size, numa_node);
137 if (!data)
138 return ERR_PTR(-ENOMEM);
139 array = data + PAGE_ALIGN(sizeof(struct bpf_array))
140 - offsetof(struct bpf_array, value);
141 } else {
142 array = bpf_map_area_alloc(array_size, numa_node);
143 }
144 if (!array)
145 return ERR_PTR(-ENOMEM);
146 array->index_mask = index_mask;
147 array->map.bypass_spec_v1 = bypass_spec_v1;
148
149 /* copy mandatory map attributes */
150 bpf_map_init_from_attr(&array->map, attr);
151 array->elem_size = elem_size;
152
153 if (percpu && bpf_array_alloc_percpu(array)) {
154 bpf_map_area_free(array);
155 return ERR_PTR(-ENOMEM);
156 }
157
158 return &array->map;
159}
160
161static void *array_map_elem_ptr(struct bpf_array* array, u32 index)
162{
163 return array->value + (u64)array->elem_size * index;
164}
165
166/* Called from syscall or from eBPF program */
167static void *array_map_lookup_elem(struct bpf_map *map, void *key)
168{
169 struct bpf_array *array = container_of(map, struct bpf_array, map);
170 u32 index = *(u32 *)key;
171
172 if (unlikely(index >= array->map.max_entries))
173 return NULL;
174
175 return array->value + (u64)array->elem_size * (index & array->index_mask);
176}
177
178static int array_map_get_hash(struct bpf_map *map)
179{
180 struct bpf_array *array = container_of(map, struct bpf_array, map);
181
182 sha256(array->value, (u64)array->elem_size * array->map.max_entries,
183 array->map.sha);
184 return 0;
185}
186
187static int array_map_direct_value_addr(const struct bpf_map *map, u64 *imm,
188 u32 off)
189{
190 struct bpf_array *array = container_of(map, struct bpf_array, map);
191
192 if (map->max_entries != 1)
193 return -ENOTSUPP;
194 if (off >= map->value_size)
195 return -EINVAL;
196
197 *imm = (unsigned long)array->value;
198 return 0;
199}
200
201static int array_map_direct_value_meta(const struct bpf_map *map, u64 imm,
202 u32 *off)
203{
204 struct bpf_array *array = container_of(map, struct bpf_array, map);
205 u64 base = (unsigned long)array->value;
206 u64 range = array->elem_size;
207
208 if (map->max_entries != 1)
209 return -ENOTSUPP;
210 if (imm < base || imm >= base + range)
211 return -ENOENT;
212
213 *off = imm - base;
214 return 0;
215}
216
217/* emit BPF instructions equivalent to C code of array_map_lookup_elem() */
218static int array_map_gen_lookup(struct bpf_map *map, struct bpf_insn *insn_buf)
219{
220 struct bpf_array *array = container_of(map, struct bpf_array, map);
221 struct bpf_insn *insn = insn_buf;
222 u32 elem_size = array->elem_size;
223 const int ret = BPF_REG_0;
224 const int map_ptr = BPF_REG_1;
225 const int index = BPF_REG_2;
226
227 if (map->map_flags & BPF_F_INNER_MAP)
228 return -EOPNOTSUPP;
229
230 *insn++ = BPF_ALU64_IMM(BPF_ADD, map_ptr, offsetof(struct bpf_array, value));
231 *insn++ = BPF_LDX_MEM(BPF_W, ret, index, 0);
232 if (!map->bypass_spec_v1) {
233 *insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 4);
234 *insn++ = BPF_ALU32_IMM(BPF_AND, ret, array->index_mask);
235 } else {
236 *insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 3);
237 }
238
239 if (is_power_of_2(elem_size)) {
240 *insn++ = BPF_ALU64_IMM(BPF_LSH, ret, ilog2(elem_size));
241 } else {
242 *insn++ = BPF_ALU64_IMM(BPF_MUL, ret, elem_size);
243 }
244 *insn++ = BPF_ALU64_REG(BPF_ADD, ret, map_ptr);
245 *insn++ = BPF_JMP_IMM(BPF_JA, 0, 0, 1);
246 *insn++ = BPF_MOV64_IMM(ret, 0);
247 return insn - insn_buf;
248}
249
250/* Called from eBPF program */
251static void *percpu_array_map_lookup_elem(struct bpf_map *map, void *key)
252{
253 struct bpf_array *array = container_of(map, struct bpf_array, map);
254 u32 index = *(u32 *)key;
255
256 if (unlikely(index >= array->map.max_entries))
257 return NULL;
258
259 return this_cpu_ptr(array->pptrs[index & array->index_mask]);
260}
261
262/* emit BPF instructions equivalent to C code of percpu_array_map_lookup_elem() */
263static int percpu_array_map_gen_lookup(struct bpf_map *map, struct bpf_insn *insn_buf)
264{
265 struct bpf_array *array = container_of(map, struct bpf_array, map);
266 struct bpf_insn *insn = insn_buf;
267
268 if (!bpf_jit_supports_percpu_insn())
269 return -EOPNOTSUPP;
270
271 if (map->map_flags & BPF_F_INNER_MAP)
272 return -EOPNOTSUPP;
273
274 BUILD_BUG_ON(offsetof(struct bpf_array, map) != 0);
275 *insn++ = BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, offsetof(struct bpf_array, pptrs));
276
277 *insn++ = BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_2, 0);
278 if (!map->bypass_spec_v1) {
279 *insn++ = BPF_JMP_IMM(BPF_JGE, BPF_REG_0, map->max_entries, 6);
280 *insn++ = BPF_ALU32_IMM(BPF_AND, BPF_REG_0, array->index_mask);
281 } else {
282 *insn++ = BPF_JMP_IMM(BPF_JGE, BPF_REG_0, map->max_entries, 5);
283 }
284
285 *insn++ = BPF_ALU64_IMM(BPF_LSH, BPF_REG_0, 3);
286 *insn++ = BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_1);
287 *insn++ = BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_0, 0);
288 *insn++ = BPF_MOV64_PERCPU_REG(BPF_REG_0, BPF_REG_0);
289 *insn++ = BPF_JMP_IMM(BPF_JA, 0, 0, 1);
290 *insn++ = BPF_MOV64_IMM(BPF_REG_0, 0);
291 return insn - insn_buf;
292}
293
294static void *percpu_array_map_lookup_percpu_elem(struct bpf_map *map, void *key, u32 cpu)
295{
296 struct bpf_array *array = container_of(map, struct bpf_array, map);
297 u32 index = *(u32 *)key;
298
299 if (cpu >= nr_cpu_ids)
300 return NULL;
301
302 if (unlikely(index >= array->map.max_entries))
303 return NULL;
304
305 return per_cpu_ptr(array->pptrs[index & array->index_mask], cpu);
306}
307
308int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value, u64 map_flags)
309{
310 struct bpf_array *array = container_of(map, struct bpf_array, map);
311 u32 index = *(u32 *)key;
312 void __percpu *pptr;
313 int cpu, off = 0;
314 u32 size;
315
316 if (unlikely(index >= array->map.max_entries))
317 return -ENOENT;
318
319 /* per_cpu areas are zero-filled and bpf programs can only
320 * access 'value_size' of them, so copying rounded areas
321 * will not leak any kernel data
322 */
323 size = array->elem_size;
324 rcu_read_lock();
325 pptr = array->pptrs[index & array->index_mask];
326 if (map_flags & BPF_F_CPU) {
327 cpu = map_flags >> 32;
328 copy_map_value(map, value, per_cpu_ptr(pptr, cpu));
329 check_and_init_map_value(map, value);
330 goto unlock;
331 }
332 for_each_possible_cpu(cpu) {
333 copy_map_value_long(map, value + off, per_cpu_ptr(pptr, cpu));
334 check_and_init_map_value(map, value + off);
335 off += size;
336 }
337unlock:
338 rcu_read_unlock();
339 return 0;
340}
341
342/* Called from syscall */
343int bpf_array_get_next_key(struct bpf_map *map, void *key, void *next_key)
344{
345 u32 index = key ? *(u32 *)key : U32_MAX;
346 u32 *next = (u32 *)next_key;
347
348 if (index >= map->max_entries) {
349 *next = 0;
350 return 0;
351 }
352
353 if (index == map->max_entries - 1)
354 return -ENOENT;
355
356 *next = index + 1;
357 return 0;
358}
359
360/* Called from syscall or from eBPF program */
361static long array_map_update_elem(struct bpf_map *map, void *key, void *value,
362 u64 map_flags)
363{
364 struct bpf_array *array = container_of(map, struct bpf_array, map);
365 u32 index = *(u32 *)key;
366 char *val;
367
368 if (unlikely((map_flags & ~BPF_F_LOCK) > BPF_EXIST))
369 /* unknown flags */
370 return -EINVAL;
371
372 if (unlikely(index >= array->map.max_entries))
373 /* all elements were pre-allocated, cannot insert a new one */
374 return -E2BIG;
375
376 if (unlikely(map_flags & BPF_NOEXIST))
377 /* all elements already exist */
378 return -EEXIST;
379
380 if (unlikely((map_flags & BPF_F_LOCK) &&
381 !btf_record_has_field(map->record, BPF_SPIN_LOCK)))
382 return -EINVAL;
383
384 if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
385 val = this_cpu_ptr(array->pptrs[index & array->index_mask]);
386 copy_map_value(map, val, value);
387 bpf_obj_cancel_fields(map, val);
388 } else {
389 val = array->value +
390 (u64)array->elem_size * (index & array->index_mask);
391 if (map_flags & BPF_F_LOCK)
392 copy_map_value_locked(map, val, value, false);
393 else
394 copy_map_value(map, val, value);
395 bpf_obj_cancel_fields(map, val);
396 }
397 return 0;
398}
399
400int bpf_percpu_array_update(struct bpf_map *map, void *key, void *value,
401 u64 map_flags)
402{
403 struct bpf_array *array = container_of(map, struct bpf_array, map);
404 u32 index = *(u32 *)key;
405 void __percpu *pptr;
406 void *ptr, *val;
407 u32 size;
408 int cpu;
409
410 if (unlikely((map_flags & BPF_F_LOCK) || (u32)map_flags > BPF_F_ALL_CPUS))
411 /* unknown flags */
412 return -EINVAL;
413
414 if (unlikely(index >= array->map.max_entries))
415 /* all elements were pre-allocated, cannot insert a new one */
416 return -E2BIG;
417
418 if (unlikely(map_flags == BPF_NOEXIST))
419 /* all elements already exist */
420 return -EEXIST;
421
422 /* the user space will provide round_up(value_size, 8) bytes that
423 * will be copied into per-cpu area. bpf programs can only access
424 * value_size of it. During lookup the same extra bytes will be
425 * returned or zeros which were zero-filled by percpu_alloc,
426 * so no kernel data leaks possible
427 */
428 size = array->elem_size;
429 rcu_read_lock();
430 pptr = array->pptrs[index & array->index_mask];
431 if (map_flags & BPF_F_CPU) {
432 cpu = map_flags >> 32;
433 ptr = per_cpu_ptr(pptr, cpu);
434 copy_map_value(map, ptr, value);
435 bpf_obj_cancel_fields(map, ptr);
436 goto unlock;
437 }
438 for_each_possible_cpu(cpu) {
439 ptr = per_cpu_ptr(pptr, cpu);
440 val = (map_flags & BPF_F_ALL_CPUS) ? value : value + size * cpu;
441 copy_map_value(map, ptr, val);
442 bpf_obj_cancel_fields(map, ptr);
443 }
444unlock:
445 rcu_read_unlock();
446 return 0;
447}
448
449/* Called from syscall or from eBPF program */
450static long array_map_delete_elem(struct bpf_map *map, void *key)
451{
452 return -EINVAL;
453}
454
455static void *array_map_vmalloc_addr(struct bpf_array *array)
456{
457 return (void *)round_down((unsigned long)array, PAGE_SIZE);
458}
459
460static void array_map_free_internal_structs(struct bpf_map *map)
461{
462 struct bpf_array *array = container_of(map, struct bpf_array, map);
463 int i;
464
465 /* We only free internal structs on uref dropping to zero */
466 if (!bpf_map_has_internal_structs(map))
467 return;
468
469 for (i = 0; i < array->map.max_entries; i++)
470 bpf_map_free_internal_structs(map, array_map_elem_ptr(array, i));
471}
472
473/* Called when map->refcnt goes to zero, either from workqueue or from syscall */
474static void array_map_free(struct bpf_map *map)
475{
476 struct bpf_array *array = container_of(map, struct bpf_array, map);
477 int i;
478
479 if (!IS_ERR_OR_NULL(map->record)) {
480 if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
481 for (i = 0; i < array->map.max_entries; i++) {
482 void __percpu *pptr = array->pptrs[i & array->index_mask];
483 int cpu;
484
485 for_each_possible_cpu(cpu) {
486 bpf_obj_free_fields(map->record, per_cpu_ptr(pptr, cpu));
487 cond_resched();
488 }
489 }
490 } else {
491 for (i = 0; i < array->map.max_entries; i++)
492 bpf_obj_free_fields(map->record, array_map_elem_ptr(array, i));
493 }
494 }
495
496 if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY)
497 bpf_array_free_percpu(array);
498
499 if (array->map.map_flags & BPF_F_MMAPABLE)
500 bpf_map_area_free(array_map_vmalloc_addr(array));
501 else
502 bpf_map_area_free(array);
503}
504
505static void array_map_seq_show_elem(struct bpf_map *map, void *key,
506 struct seq_file *m)
507{
508 void *value;
509
510 rcu_read_lock();
511
512 value = array_map_lookup_elem(map, key);
513 if (!value) {
514 rcu_read_unlock();
515 return;
516 }
517
518 if (map->btf_key_type_id)
519 seq_printf(m, "%u: ", *(u32 *)key);
520 btf_type_seq_show(map->btf, map->btf_value_type_id, value, m);
521 seq_putc(m, '\n');
522
523 rcu_read_unlock();
524}
525
526static void percpu_array_map_seq_show_elem(struct bpf_map *map, void *key,
527 struct seq_file *m)
528{
529 struct bpf_array *array = container_of(map, struct bpf_array, map);
530 u32 index = *(u32 *)key;
531 void __percpu *pptr;
532 int cpu;
533
534 rcu_read_lock();
535
536 seq_printf(m, "%u: {\n", *(u32 *)key);
537 pptr = array->pptrs[index & array->index_mask];
538 for_each_possible_cpu(cpu) {
539 seq_printf(m, "\tcpu%d: ", cpu);
540 btf_type_seq_show(map->btf, map->btf_value_type_id,
541 per_cpu_ptr(pptr, cpu), m);
542 seq_putc(m, '\n');
543 }
544 seq_puts(m, "}\n");
545
546 rcu_read_unlock();
547}
548
549static int array_map_check_btf(struct bpf_map *map,
550 const struct btf *btf,
551 const struct btf_type *key_type,
552 const struct btf_type *value_type)
553{
554 /* One exception for keyless BTF: .bss/.data/.rodata map */
555 if (btf_type_is_void(key_type)) {
556 if (map->map_type != BPF_MAP_TYPE_ARRAY ||
557 map->max_entries != 1)
558 return -EINVAL;
559
560 if (BTF_INFO_KIND(value_type->info) != BTF_KIND_DATASEC)
561 return -EINVAL;
562
563 return 0;
564 }
565
566 /*
567 * Bpf array can only take a u32 key. This check makes sure
568 * that the btf matches the attr used during map_create.
569 */
570 if (!btf_type_is_i32(key_type))
571 return -EINVAL;
572
573 return 0;
574}
575
576static int array_map_mmap(struct bpf_map *map, struct vm_area_struct *vma)
577{
578 struct bpf_array *array = container_of(map, struct bpf_array, map);
579 pgoff_t pgoff = PAGE_ALIGN(sizeof(*array)) >> PAGE_SHIFT;
580
581 if (!(map->map_flags & BPF_F_MMAPABLE))
582 return -EINVAL;
583
584 if (vma->vm_pgoff * PAGE_SIZE + (vma->vm_end - vma->vm_start) >
585 PAGE_ALIGN((u64)array->map.max_entries * array->elem_size))
586 return -EINVAL;
587
588 return remap_vmalloc_range(vma, array_map_vmalloc_addr(array),
589 vma->vm_pgoff + pgoff);
590}
591
592static bool array_map_meta_equal(const struct bpf_map *meta0,
593 const struct bpf_map *meta1)
594{
595 if (!bpf_map_meta_equal(meta0, meta1))
596 return false;
597 return meta0->map_flags & BPF_F_INNER_MAP ? true :
598 meta0->max_entries == meta1->max_entries;
599}
600
601struct bpf_iter_seq_array_map_info {
602 struct bpf_map *map;
603 void *percpu_value_buf;
604 u32 index;
605};
606
607static void *bpf_array_map_seq_start(struct seq_file *seq, loff_t *pos)
608{
609 struct bpf_iter_seq_array_map_info *info = seq->private;
610 struct bpf_map *map = info->map;
611 struct bpf_array *array;
612 u32 index;
613
614 if (info->index >= map->max_entries)
615 return NULL;
616
617 if (*pos == 0)
618 ++*pos;
619 array = container_of(map, struct bpf_array, map);
620 index = info->index & array->index_mask;
621 if (info->percpu_value_buf)
622 return (void *)(uintptr_t)array->pptrs[index];
623 return array_map_elem_ptr(array, index);
624}
625
626static void *bpf_array_map_seq_next(struct seq_file *seq, void *v, loff_t *pos)
627{
628 struct bpf_iter_seq_array_map_info *info = seq->private;
629 struct bpf_map *map = info->map;
630 struct bpf_array *array;
631 u32 index;
632
633 ++*pos;
634 ++info->index;
635 if (info->index >= map->max_entries)
636 return NULL;
637
638 array = container_of(map, struct bpf_array, map);
639 index = info->index & array->index_mask;
640 if (info->percpu_value_buf)
641 return (void *)(uintptr_t)array->pptrs[index];
642 return array_map_elem_ptr(array, index);
643}
644
645static int __bpf_array_map_seq_show(struct seq_file *seq, void *v)
646{
647 struct bpf_iter_seq_array_map_info *info = seq->private;
648 struct bpf_iter__bpf_map_elem ctx = {};
649 struct bpf_map *map = info->map;
650 struct bpf_array *array = container_of(map, struct bpf_array, map);
651 struct bpf_iter_meta meta;
652 struct bpf_prog *prog;
653 int off = 0, cpu = 0;
654 void __percpu *pptr;
655 u32 size;
656
657 meta.seq = seq;
658 prog = bpf_iter_get_info(&meta, v == NULL);
659 if (!prog)
660 return 0;
661
662 ctx.meta = &meta;
663 ctx.map = info->map;
664 if (v) {
665 ctx.key = &info->index;
666
667 if (!info->percpu_value_buf) {
668 ctx.value = v;
669 } else {
670 pptr = (void __percpu *)(uintptr_t)v;
671 size = array->elem_size;
672 for_each_possible_cpu(cpu) {
673 copy_map_value_long(map, info->percpu_value_buf + off,
674 per_cpu_ptr(pptr, cpu));
675 check_and_init_map_value(map, info->percpu_value_buf + off);
676 off += size;
677 }
678 ctx.value = info->percpu_value_buf;
679 }
680 }
681
682 return bpf_iter_run_prog(prog, &ctx);
683}
684
685static int bpf_array_map_seq_show(struct seq_file *seq, void *v)
686{
687 return __bpf_array_map_seq_show(seq, v);
688}
689
690static void bpf_array_map_seq_stop(struct seq_file *seq, void *v)
691{
692 if (!v)
693 (void)__bpf_array_map_seq_show(seq, NULL);
694}
695
696static int bpf_iter_init_array_map(void *priv_data,
697 struct bpf_iter_aux_info *aux)
698{
699 struct bpf_iter_seq_array_map_info *seq_info = priv_data;
700 struct bpf_map *map = aux->map;
701 struct bpf_array *array = container_of(map, struct bpf_array, map);
702 void *value_buf;
703 u32 buf_size;
704
705 if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
706 buf_size = array->elem_size * num_possible_cpus();
707 value_buf = kmalloc(buf_size, GFP_USER | __GFP_NOWARN);
708 if (!value_buf)
709 return -ENOMEM;
710
711 seq_info->percpu_value_buf = value_buf;
712 }
713
714 /* bpf_iter_attach_map() acquires a map uref, and the uref may be
715 * released before or in the middle of iterating map elements, so
716 * acquire an extra map uref for iterator.
717 */
718 bpf_map_inc_with_uref(map);
719 seq_info->map = map;
720 return 0;
721}
722
723static void bpf_iter_fini_array_map(void *priv_data)
724{
725 struct bpf_iter_seq_array_map_info *seq_info = priv_data;
726
727 bpf_map_put_with_uref(seq_info->map);
728 kfree(seq_info->percpu_value_buf);
729}
730
731static const struct seq_operations bpf_array_map_seq_ops = {
732 .start = bpf_array_map_seq_start,
733 .next = bpf_array_map_seq_next,
734 .stop = bpf_array_map_seq_stop,
735 .show = bpf_array_map_seq_show,
736};
737
738static const struct bpf_iter_seq_info iter_seq_info = {
739 .seq_ops = &bpf_array_map_seq_ops,
740 .init_seq_private = bpf_iter_init_array_map,
741 .fini_seq_private = bpf_iter_fini_array_map,
742 .seq_priv_size = sizeof(struct bpf_iter_seq_array_map_info),
743};
744
745static long bpf_for_each_array_elem(struct bpf_map *map, bpf_callback_t callback_fn,
746 void *callback_ctx, u64 flags)
747{
748 u32 i, key, num_elems = 0;
749 struct bpf_array *array;
750 bool is_percpu;
751 u64 ret = 0;
752 void *val;
753
754 cant_migrate();
755
756 if (flags != 0)
757 return -EINVAL;
758
759 is_percpu = map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY;
760 array = container_of(map, struct bpf_array, map);
761 for (i = 0; i < map->max_entries; i++) {
762 if (is_percpu)
763 val = this_cpu_ptr(array->pptrs[i]);
764 else
765 val = array_map_elem_ptr(array, i);
766 num_elems++;
767 key = i;
768 ret = callback_fn((u64)(long)map, (u64)(long)&key,
769 (u64)(long)val, (u64)(long)callback_ctx, 0);
770 /* return value: 0 - continue, 1 - stop and return */
771 if (ret)
772 break;
773 }
774
775 return num_elems;
776}
777
778static u64 array_map_mem_usage(const struct bpf_map *map)
779{
780 struct bpf_array *array = container_of(map, struct bpf_array, map);
781 bool percpu = map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY;
782 u32 elem_size = array->elem_size;
783 u64 entries = map->max_entries;
784 u64 usage = sizeof(*array);
785
786 if (percpu) {
787 usage += entries * sizeof(void *);
788 usage += entries * elem_size * num_possible_cpus();
789 } else {
790 if (map->map_flags & BPF_F_MMAPABLE) {
791 usage = PAGE_ALIGN(usage);
792 usage += PAGE_ALIGN(entries * elem_size);
793 } else {
794 usage += entries * elem_size;
795 }
796 }
797 return usage;
798}
799
800BTF_ID_LIST_SINGLE(array_map_btf_ids, struct, bpf_array)
801const struct bpf_map_ops array_map_ops = {
802 .map_meta_equal = array_map_meta_equal,
803 .map_alloc_check = array_map_alloc_check,
804 .map_alloc = array_map_alloc,
805 .map_free = array_map_free,
806 .map_get_next_key = bpf_array_get_next_key,
807 .map_release_uref = array_map_free_internal_structs,
808 .map_lookup_elem = array_map_lookup_elem,
809 .map_update_elem = array_map_update_elem,
810 .map_delete_elem = array_map_delete_elem,
811 .map_gen_lookup = array_map_gen_lookup,
812 .map_direct_value_addr = array_map_direct_value_addr,
813 .map_direct_value_meta = array_map_direct_value_meta,
814 .map_mmap = array_map_mmap,
815 .map_seq_show_elem = array_map_seq_show_elem,
816 .map_check_btf = array_map_check_btf,
817 .map_lookup_batch = generic_map_lookup_batch,
818 .map_update_batch = generic_map_update_batch,
819 .map_set_for_each_callback_args = map_set_for_each_callback_args,
820 .map_for_each_callback = bpf_for_each_array_elem,
821 .map_mem_usage = array_map_mem_usage,
822 .map_btf_id = &array_map_btf_ids[0],
823 .iter_seq_info = &iter_seq_info,
824 .map_get_hash = &array_map_get_hash,
825};
826
827const struct bpf_map_ops percpu_array_map_ops = {
828 .map_meta_equal = array_map_meta_equal,
829 .map_alloc_check = array_map_alloc_check,
830 .map_alloc = array_map_alloc,
831 .map_free = array_map_free,
832 .map_get_next_key = bpf_array_get_next_key,
833 .map_lookup_elem = percpu_array_map_lookup_elem,
834 .map_gen_lookup = percpu_array_map_gen_lookup,
835 .map_update_elem = array_map_update_elem,
836 .map_delete_elem = array_map_delete_elem,
837 .map_lookup_percpu_elem = percpu_array_map_lookup_percpu_elem,
838 .map_seq_show_elem = percpu_array_map_seq_show_elem,
839 .map_check_btf = array_map_check_btf,
840 .map_lookup_batch = generic_map_lookup_batch,
841 .map_update_batch = generic_map_update_batch,
842 .map_set_for_each_callback_args = map_set_for_each_callback_args,
843 .map_for_each_callback = bpf_for_each_array_elem,
844 .map_mem_usage = array_map_mem_usage,
845 .map_btf_id = &array_map_btf_ids[0],
846 .iter_seq_info = &iter_seq_info,
847};
848
849static int fd_array_map_alloc_check(union bpf_attr *attr)
850{
851 /* only file descriptors can be stored in this type of map */
852 if (attr->value_size != sizeof(u32))
853 return -EINVAL;
854 /* Program read-only/write-only not supported for special maps yet. */
855 if (attr->map_flags & (BPF_F_RDONLY_PROG | BPF_F_WRONLY_PROG))
856 return -EINVAL;
857 return array_map_alloc_check(attr);
858}
859
860static void fd_array_map_free(struct bpf_map *map)
861{
862 struct bpf_array *array = container_of(map, struct bpf_array, map);
863 int i;
864
865 /* make sure it's empty */
866 for (i = 0; i < array->map.max_entries; i++)
867 BUG_ON(array->ptrs[i] != NULL);
868
869 bpf_map_area_free(array);
870}
871
872static void *fd_array_map_lookup_elem(struct bpf_map *map, void *key)
873{
874 return ERR_PTR(-EOPNOTSUPP);
875}
876
877/* only called from syscall */
878int bpf_fd_array_map_lookup_elem(struct bpf_map *map, void *key, u32 *value)
879{
880 void **elem, *ptr;
881 int ret = 0;
882
883 if (!map->ops->map_fd_sys_lookup_elem)
884 return -ENOTSUPP;
885
886 rcu_read_lock();
887 elem = array_map_lookup_elem(map, key);
888 if (elem && (ptr = READ_ONCE(*elem)))
889 *value = map->ops->map_fd_sys_lookup_elem(ptr);
890 else
891 ret = -ENOENT;
892 rcu_read_unlock();
893
894 return ret;
895}
896
897/* only called from syscall */
898int bpf_fd_array_map_update_elem(struct bpf_map *map, struct file *map_file,
899 void *key, void *value, u64 map_flags)
900{
901 struct bpf_array *array = container_of(map, struct bpf_array, map);
902 void *new_ptr, *old_ptr;
903 u32 index = *(u32 *)key, ufd;
904
905 if (map_flags != BPF_ANY)
906 return -EINVAL;
907
908 if (index >= array->map.max_entries)
909 return -E2BIG;
910
911 ufd = *(u32 *)value;
912 new_ptr = map->ops->map_fd_get_ptr(map, map_file, ufd);
913 if (IS_ERR(new_ptr))
914 return PTR_ERR(new_ptr);
915
916 if (map->ops->map_poke_run) {
917 mutex_lock(&array->aux->poke_mutex);
918 old_ptr = xchg(array->ptrs + index, new_ptr);
919 map->ops->map_poke_run(map, index, old_ptr, new_ptr);
920 mutex_unlock(&array->aux->poke_mutex);
921 } else {
922 old_ptr = xchg(array->ptrs + index, new_ptr);
923 }
924
925 if (old_ptr)
926 map->ops->map_fd_put_ptr(map, old_ptr, true);
927 return 0;
928}
929
930static long __fd_array_map_delete_elem(struct bpf_map *map, void *key, bool need_defer)
931{
932 struct bpf_array *array = container_of(map, struct bpf_array, map);
933 void *old_ptr;
934 u32 index = *(u32 *)key;
935
936 if (index >= array->map.max_entries)
937 return -E2BIG;
938
939 if (map->ops->map_poke_run) {
940 mutex_lock(&array->aux->poke_mutex);
941 old_ptr = xchg(array->ptrs + index, NULL);
942 map->ops->map_poke_run(map, index, old_ptr, NULL);
943 mutex_unlock(&array->aux->poke_mutex);
944 } else {
945 old_ptr = xchg(array->ptrs + index, NULL);
946 }
947
948 if (old_ptr) {
949 map->ops->map_fd_put_ptr(map, old_ptr, need_defer);
950 return 0;
951 } else {
952 return -ENOENT;
953 }
954}
955
956static long fd_array_map_delete_elem(struct bpf_map *map, void *key)
957{
958 return __fd_array_map_delete_elem(map, key, true);
959}
960
961static void *prog_fd_array_get_ptr(struct bpf_map *map,
962 struct file *map_file, int fd)
963{
964 struct bpf_prog *prog = bpf_prog_get(fd);
965 bool is_extended;
966
967 if (IS_ERR(prog))
968 return prog;
969
970 if (prog->type == BPF_PROG_TYPE_EXT ||
971 !bpf_prog_map_compatible(map, prog)) {
972 bpf_prog_put(prog);
973 return ERR_PTR(-EINVAL);
974 }
975
976 mutex_lock(&prog->aux->ext_mutex);
977 is_extended = prog->aux->is_extended;
978 if (!is_extended)
979 prog->aux->prog_array_member_cnt++;
980 mutex_unlock(&prog->aux->ext_mutex);
981 if (is_extended) {
982 /* Extended prog can not be tail callee. It's to prevent a
983 * potential infinite loop like:
984 * tail callee prog entry -> tail callee prog subprog ->
985 * freplace prog entry --tailcall-> tail callee prog entry.
986 */
987 bpf_prog_put(prog);
988 return ERR_PTR(-EBUSY);
989 }
990
991 return prog;
992}
993
994static void prog_fd_array_put_ptr(struct bpf_map *map, void *ptr, bool need_defer)
995{
996 struct bpf_prog *prog = ptr;
997
998 mutex_lock(&prog->aux->ext_mutex);
999 prog->aux->prog_array_member_cnt--;
1000 mutex_unlock(&prog->aux->ext_mutex);
1001 /* bpf_prog is freed after one RCU or tasks trace grace period */
1002 bpf_prog_put(prog);
1003}
1004
1005static u32 prog_fd_array_sys_lookup_elem(void *ptr)
1006{
1007 return ((struct bpf_prog *)ptr)->aux->id;
1008}
1009
1010/* decrement refcnt of all bpf_progs that are stored in this map */
1011static void bpf_fd_array_map_clear(struct bpf_map *map, bool need_defer)
1012{
1013 struct bpf_array *array = container_of(map, struct bpf_array, map);
1014 int i;
1015
1016 for (i = 0; i < array->map.max_entries; i++) {
1017 __fd_array_map_delete_elem(map, &i, need_defer);
1018 cond_resched();
1019 }
1020}
1021
1022static void prog_array_map_seq_show_elem(struct bpf_map *map, void *key,
1023 struct seq_file *m)
1024{
1025 void **elem, *ptr;
1026 u32 prog_id;
1027
1028 rcu_read_lock();
1029
1030 elem = array_map_lookup_elem(map, key);
1031 if (elem) {
1032 ptr = READ_ONCE(*elem);
1033 if (ptr) {
1034 seq_printf(m, "%u: ", *(u32 *)key);
1035 prog_id = prog_fd_array_sys_lookup_elem(ptr);
1036 btf_type_seq_show(map->btf, map->btf_value_type_id,
1037 &prog_id, m);
1038 seq_putc(m, '\n');
1039 }
1040 }
1041
1042 rcu_read_unlock();
1043}
1044
1045struct prog_poke_elem {
1046 struct list_head list;
1047 struct bpf_prog_aux *aux;
1048};
1049
1050static int prog_array_map_poke_track(struct bpf_map *map,
1051 struct bpf_prog_aux *prog_aux)
1052{
1053 struct prog_poke_elem *elem;
1054 struct bpf_array_aux *aux;
1055 int ret = 0;
1056
1057 aux = container_of(map, struct bpf_array, map)->aux;
1058 mutex_lock(&aux->poke_mutex);
1059 list_for_each_entry(elem, &aux->poke_progs, list) {
1060 if (elem->aux == prog_aux)
1061 goto out;
1062 }
1063
1064 elem = kmalloc_obj(*elem);
1065 if (!elem) {
1066 ret = -ENOMEM;
1067 goto out;
1068 }
1069
1070 INIT_LIST_HEAD(&elem->list);
1071 /* We must track the program's aux info at this point in time
1072 * since the program pointer itself may not be stable yet, see
1073 * also comment in prog_array_map_poke_run().
1074 */
1075 elem->aux = prog_aux;
1076
1077 list_add_tail(&elem->list, &aux->poke_progs);
1078out:
1079 mutex_unlock(&aux->poke_mutex);
1080 return ret;
1081}
1082
1083static void prog_array_map_poke_untrack(struct bpf_map *map,
1084 struct bpf_prog_aux *prog_aux)
1085{
1086 struct prog_poke_elem *elem, *tmp;
1087 struct bpf_array_aux *aux;
1088
1089 aux = container_of(map, struct bpf_array, map)->aux;
1090 mutex_lock(&aux->poke_mutex);
1091 list_for_each_entry_safe(elem, tmp, &aux->poke_progs, list) {
1092 if (elem->aux == prog_aux) {
1093 list_del_init(&elem->list);
1094 kfree(elem);
1095 break;
1096 }
1097 }
1098 mutex_unlock(&aux->poke_mutex);
1099}
1100
1101void __weak bpf_arch_poke_desc_update(struct bpf_jit_poke_descriptor *poke,
1102 struct bpf_prog *new, struct bpf_prog *old)
1103{
1104 WARN_ON_ONCE(1);
1105}
1106
1107static void prog_array_map_poke_run(struct bpf_map *map, u32 key,
1108 struct bpf_prog *old,
1109 struct bpf_prog *new)
1110{
1111 struct prog_poke_elem *elem;
1112 struct bpf_array_aux *aux;
1113
1114 aux = container_of(map, struct bpf_array, map)->aux;
1115 WARN_ON_ONCE(!mutex_is_locked(&aux->poke_mutex));
1116
1117 list_for_each_entry(elem, &aux->poke_progs, list) {
1118 struct bpf_jit_poke_descriptor *poke;
1119 int i;
1120
1121 for (i = 0; i < elem->aux->size_poke_tab; i++) {
1122 poke = &elem->aux->poke_tab[i];
1123
1124 /* Few things to be aware of:
1125 *
1126 * 1) We can only ever access aux in this context, but
1127 * not aux->prog since it might not be stable yet and
1128 * there could be danger of use after free otherwise.
1129 * 2) Initially when we start tracking aux, the program
1130 * is not JITed yet and also does not have a kallsyms
1131 * entry. We skip these as poke->tailcall_target_stable
1132 * is not active yet. The JIT will do the final fixup
1133 * before setting it stable. The various
1134 * poke->tailcall_target_stable are successively
1135 * activated, so tail call updates can arrive from here
1136 * while JIT is still finishing its final fixup for
1137 * non-activated poke entries.
1138 * 3) Also programs reaching refcount of zero while patching
1139 * is in progress is okay since we're protected under
1140 * poke_mutex and untrack the programs before the JIT
1141 * buffer is freed.
1142 */
1143 if (!READ_ONCE(poke->tailcall_target_stable))
1144 continue;
1145 if (poke->reason != BPF_POKE_REASON_TAIL_CALL)
1146 continue;
1147 if (poke->tail_call.map != map ||
1148 poke->tail_call.key != key)
1149 continue;
1150
1151 bpf_arch_poke_desc_update(poke, new, old);
1152 }
1153 }
1154}
1155
1156static void prog_array_map_clear_deferred(struct work_struct *work)
1157{
1158 struct bpf_map *map = container_of(work, struct bpf_array_aux,
1159 work)->map;
1160 bpf_fd_array_map_clear(map, true);
1161 bpf_map_put(map);
1162}
1163
1164static void prog_array_map_clear(struct bpf_map *map)
1165{
1166 struct bpf_array_aux *aux = container_of(map, struct bpf_array,
1167 map)->aux;
1168 bpf_map_inc(map);
1169 schedule_work(&aux->work);
1170}
1171
1172static struct bpf_map *prog_array_map_alloc(union bpf_attr *attr)
1173{
1174 struct bpf_array_aux *aux;
1175 struct bpf_map *map;
1176
1177 aux = kzalloc_obj(*aux, GFP_KERNEL_ACCOUNT);
1178 if (!aux)
1179 return ERR_PTR(-ENOMEM);
1180
1181 INIT_WORK(&aux->work, prog_array_map_clear_deferred);
1182 INIT_LIST_HEAD(&aux->poke_progs);
1183 mutex_init(&aux->poke_mutex);
1184
1185 map = array_map_alloc(attr);
1186 if (IS_ERR(map)) {
1187 kfree(aux);
1188 return map;
1189 }
1190
1191 container_of(map, struct bpf_array, map)->aux = aux;
1192 aux->map = map;
1193
1194 return map;
1195}
1196
1197static void prog_array_map_free(struct bpf_map *map)
1198{
1199 struct prog_poke_elem *elem, *tmp;
1200 struct bpf_array_aux *aux;
1201
1202 aux = container_of(map, struct bpf_array, map)->aux;
1203 list_for_each_entry_safe(elem, tmp, &aux->poke_progs, list) {
1204 list_del_init(&elem->list);
1205 kfree(elem);
1206 }
1207 kfree(aux);
1208 fd_array_map_free(map);
1209}
1210
1211/* prog_array->aux->{type,jited} is a runtime binding.
1212 * Doing static check alone in the verifier is not enough.
1213 * Thus, prog_array_map cannot be used as an inner_map
1214 * and map_meta_equal is not implemented.
1215 */
1216const struct bpf_map_ops prog_array_map_ops = {
1217 .map_alloc_check = fd_array_map_alloc_check,
1218 .map_alloc = prog_array_map_alloc,
1219 .map_free = prog_array_map_free,
1220 .map_poke_track = prog_array_map_poke_track,
1221 .map_poke_untrack = prog_array_map_poke_untrack,
1222 .map_poke_run = prog_array_map_poke_run,
1223 .map_get_next_key = bpf_array_get_next_key,
1224 .map_lookup_elem = fd_array_map_lookup_elem,
1225 .map_delete_elem = fd_array_map_delete_elem,
1226 .map_fd_get_ptr = prog_fd_array_get_ptr,
1227 .map_fd_put_ptr = prog_fd_array_put_ptr,
1228 .map_fd_sys_lookup_elem = prog_fd_array_sys_lookup_elem,
1229 .map_release_uref = prog_array_map_clear,
1230 .map_seq_show_elem = prog_array_map_seq_show_elem,
1231 .map_mem_usage = array_map_mem_usage,
1232 .map_btf_id = &array_map_btf_ids[0],
1233};
1234
1235static struct bpf_event_entry *bpf_event_entry_gen(struct file *perf_file,
1236 struct file *map_file)
1237{
1238 struct bpf_event_entry *ee;
1239
1240 ee = kzalloc_obj(*ee);
1241 if (ee) {
1242 ee->event = perf_file->private_data;
1243 ee->perf_file = perf_file;
1244 ee->map_file = map_file;
1245 }
1246
1247 return ee;
1248}
1249
1250static void __bpf_event_entry_free(struct rcu_head *rcu)
1251{
1252 struct bpf_event_entry *ee;
1253
1254 ee = container_of(rcu, struct bpf_event_entry, rcu);
1255 fput(ee->perf_file);
1256 kfree(ee);
1257}
1258
1259static void bpf_event_entry_free_rcu(struct bpf_event_entry *ee)
1260{
1261 call_rcu(&ee->rcu, __bpf_event_entry_free);
1262}
1263
1264static void *perf_event_fd_array_get_ptr(struct bpf_map *map,
1265 struct file *map_file, int fd)
1266{
1267 struct bpf_event_entry *ee;
1268 struct perf_event *event;
1269 struct file *perf_file;
1270 u64 value;
1271
1272 perf_file = perf_event_get(fd);
1273 if (IS_ERR(perf_file))
1274 return perf_file;
1275
1276 ee = ERR_PTR(-EOPNOTSUPP);
1277 event = perf_file->private_data;
1278 if (perf_event_read_local(event, &value, NULL, NULL) == -EOPNOTSUPP)
1279 goto err_out;
1280
1281 ee = bpf_event_entry_gen(perf_file, map_file);
1282 if (ee)
1283 return ee;
1284 ee = ERR_PTR(-ENOMEM);
1285err_out:
1286 fput(perf_file);
1287 return ee;
1288}
1289
1290static void perf_event_fd_array_put_ptr(struct bpf_map *map, void *ptr, bool need_defer)
1291{
1292 /* bpf_perf_event is freed after one RCU grace period */
1293 bpf_event_entry_free_rcu(ptr);
1294}
1295
1296static void perf_event_fd_array_release(struct bpf_map *map,
1297 struct file *map_file)
1298{
1299 struct bpf_array *array = container_of(map, struct bpf_array, map);
1300 struct bpf_event_entry *ee;
1301 int i;
1302
1303 if (map->map_flags & BPF_F_PRESERVE_ELEMS)
1304 return;
1305
1306 rcu_read_lock();
1307 for (i = 0; i < array->map.max_entries; i++) {
1308 ee = READ_ONCE(array->ptrs[i]);
1309 if (ee && ee->map_file == map_file)
1310 __fd_array_map_delete_elem(map, &i, true);
1311 }
1312 rcu_read_unlock();
1313}
1314
1315static void perf_event_fd_array_map_free(struct bpf_map *map)
1316{
1317 if (map->map_flags & BPF_F_PRESERVE_ELEMS)
1318 bpf_fd_array_map_clear(map, false);
1319 fd_array_map_free(map);
1320}
1321
1322const struct bpf_map_ops perf_event_array_map_ops = {
1323 .map_meta_equal = bpf_map_meta_equal,
1324 .map_alloc_check = fd_array_map_alloc_check,
1325 .map_alloc = array_map_alloc,
1326 .map_free = perf_event_fd_array_map_free,
1327 .map_get_next_key = bpf_array_get_next_key,
1328 .map_lookup_elem = fd_array_map_lookup_elem,
1329 .map_delete_elem = fd_array_map_delete_elem,
1330 .map_fd_get_ptr = perf_event_fd_array_get_ptr,
1331 .map_fd_put_ptr = perf_event_fd_array_put_ptr,
1332 .map_release = perf_event_fd_array_release,
1333 .map_check_btf = map_check_no_btf,
1334 .map_mem_usage = array_map_mem_usage,
1335 .map_btf_id = &array_map_btf_ids[0],
1336};
1337
1338#ifdef CONFIG_CGROUPS
1339static void *cgroup_fd_array_get_ptr(struct bpf_map *map,
1340 struct file *map_file /* not used */,
1341 int fd)
1342{
1343 return cgroup_get_from_fd(fd);
1344}
1345
1346static void cgroup_fd_array_put_ptr(struct bpf_map *map, void *ptr, bool need_defer)
1347{
1348 /* cgroup_put free cgrp after a rcu grace period */
1349 cgroup_put(ptr);
1350}
1351
1352static void cgroup_fd_array_free(struct bpf_map *map)
1353{
1354 bpf_fd_array_map_clear(map, false);
1355 fd_array_map_free(map);
1356}
1357
1358const struct bpf_map_ops cgroup_array_map_ops = {
1359 .map_meta_equal = bpf_map_meta_equal,
1360 .map_alloc_check = fd_array_map_alloc_check,
1361 .map_alloc = array_map_alloc,
1362 .map_free = cgroup_fd_array_free,
1363 .map_get_next_key = bpf_array_get_next_key,
1364 .map_lookup_elem = fd_array_map_lookup_elem,
1365 .map_delete_elem = fd_array_map_delete_elem,
1366 .map_fd_get_ptr = cgroup_fd_array_get_ptr,
1367 .map_fd_put_ptr = cgroup_fd_array_put_ptr,
1368 .map_check_btf = map_check_no_btf,
1369 .map_mem_usage = array_map_mem_usage,
1370 .map_btf_id = &array_map_btf_ids[0],
1371};
1372#endif
1373
1374static struct bpf_map *array_of_map_alloc(union bpf_attr *attr)
1375{
1376 struct bpf_map *map, *inner_map_meta;
1377
1378 inner_map_meta = bpf_map_meta_alloc(attr->inner_map_fd);
1379 if (IS_ERR(inner_map_meta))
1380 return inner_map_meta;
1381
1382 map = array_map_alloc(attr);
1383 if (IS_ERR(map)) {
1384 bpf_map_meta_free(inner_map_meta);
1385 return map;
1386 }
1387
1388 map->inner_map_meta = inner_map_meta;
1389
1390 return map;
1391}
1392
1393static void array_of_map_free(struct bpf_map *map)
1394{
1395 /* map->inner_map_meta is only accessed by syscall which
1396 * is protected by fdget/fdput.
1397 */
1398 bpf_map_meta_free(map->inner_map_meta);
1399 bpf_fd_array_map_clear(map, false);
1400 fd_array_map_free(map);
1401}
1402
1403static void *array_of_map_lookup_elem(struct bpf_map *map, void *key)
1404{
1405 struct bpf_map **inner_map = array_map_lookup_elem(map, key);
1406
1407 if (!inner_map)
1408 return NULL;
1409
1410 return READ_ONCE(*inner_map);
1411}
1412
1413static int array_of_map_gen_lookup(struct bpf_map *map,
1414 struct bpf_insn *insn_buf)
1415{
1416 struct bpf_array *array = container_of(map, struct bpf_array, map);
1417 u32 elem_size = array->elem_size;
1418 struct bpf_insn *insn = insn_buf;
1419 const int ret = BPF_REG_0;
1420 const int map_ptr = BPF_REG_1;
1421 const int index = BPF_REG_2;
1422
1423 *insn++ = BPF_ALU64_IMM(BPF_ADD, map_ptr, offsetof(struct bpf_array, value));
1424 *insn++ = BPF_LDX_MEM(BPF_W, ret, index, 0);
1425 if (!map->bypass_spec_v1) {
1426 *insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 6);
1427 *insn++ = BPF_ALU32_IMM(BPF_AND, ret, array->index_mask);
1428 } else {
1429 *insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 5);
1430 }
1431 if (is_power_of_2(elem_size))
1432 *insn++ = BPF_ALU64_IMM(BPF_LSH, ret, ilog2(elem_size));
1433 else
1434 *insn++ = BPF_ALU64_IMM(BPF_MUL, ret, elem_size);
1435 *insn++ = BPF_ALU64_REG(BPF_ADD, ret, map_ptr);
1436 *insn++ = BPF_LDX_MEM(BPF_DW, ret, ret, 0);
1437 *insn++ = BPF_JMP_IMM(BPF_JEQ, ret, 0, 1);
1438 *insn++ = BPF_JMP_IMM(BPF_JA, 0, 0, 1);
1439 *insn++ = BPF_MOV64_IMM(ret, 0);
1440
1441 return insn - insn_buf;
1442}
1443
1444const struct bpf_map_ops array_of_maps_map_ops = {
1445 .map_alloc_check = fd_array_map_alloc_check,
1446 .map_alloc = array_of_map_alloc,
1447 .map_free = array_of_map_free,
1448 .map_get_next_key = bpf_array_get_next_key,
1449 .map_lookup_elem = array_of_map_lookup_elem,
1450 .map_delete_elem = fd_array_map_delete_elem,
1451 .map_fd_get_ptr = bpf_map_fd_get_ptr,
1452 .map_fd_put_ptr = bpf_map_fd_put_ptr,
1453 .map_fd_sys_lookup_elem = bpf_map_fd_sys_lookup_elem,
1454 .map_gen_lookup = array_of_map_gen_lookup,
1455 .map_lookup_batch = generic_map_lookup_batch,
1456 .map_update_batch = generic_map_update_batch,
1457 .map_check_btf = map_check_no_btf,
1458 .map_mem_usage = array_map_mem_usage,
1459 .map_btf_id = &array_map_btf_ids[0],
1460};