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	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0-only
 /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
  * Copyright (c) 2016,2017 Facebook
  */
 #include <linux/bpf.h>
 #include <linux/btf.h>
 #include <linux/err.h>
 #include <linux/slab.h>
 #include <linux/mm.h>
 #include <linux/filter.h>
 #include <linux/perf_event.h>
 #include <uapi/linux/btf.h>
 #include <linux/rcupdate_trace.h>
 #include <linux/btf_ids.h>
 
 #include "map_in_map.h"
 
 #define ARRAY_CREATE_FLAG_MASK \
     (BPF_F_NUMA_NODE | BPF_F_MMAPABLE | BPF_F_ACCESS_MASK | \
      BPF_F_PRESERVE_ELEMS | BPF_F_INNER_MAP)
 
 static void bpf_array_free_percpu(struct bpf_array *array)
 {
     int i;
 
     for (i = 0; i < array->map.max_entries; i++) {
         free_percpu(array->pptrs[i]);
         cond_resched();
     }
 }
 
 static int bpf_array_alloc_percpu(struct bpf_array *array)
 {
     void __percpu *ptr;
     int i;
 
     for (i = 0; i < array->map.max_entries; i++) {
         ptr = bpf_map_alloc_percpu(&array->map, array->elem_size, 8,
                        GFP_USER | __GFP_NOWARN);
         if (!ptr) {
             bpf_array_free_percpu(array);
             return -ENOMEM;
         }
         array->pptrs[i] = ptr;
         cond_resched();
     }
 
     return 0;
 }
 
 /* Called from syscall */
 int array_map_alloc_check(union bpf_attr *attr)
 {
     bool percpu = attr->map_type == BPF_MAP_TYPE_PERCPU_ARRAY;
     int numa_node = bpf_map_attr_numa_node(attr);
 
     /* check sanity of attributes */
     if (attr->max_entries == 0 || attr->key_size != 4 ||
         attr->value_size == 0 ||
         attr->map_flags & ~ARRAY_CREATE_FLAG_MASK ||
         !bpf_map_flags_access_ok(attr->map_flags) ||
         (percpu && numa_node != NUMA_NO_NODE))
         return -EINVAL;
 
     if (attr->map_type != BPF_MAP_TYPE_ARRAY &&
         attr->map_flags & (BPF_F_MMAPABLE | BPF_F_INNER_MAP))
         return -EINVAL;
 
     if (attr->map_type != BPF_MAP_TYPE_PERF_EVENT_ARRAY &&
         attr->map_flags & BPF_F_PRESERVE_ELEMS)
         return -EINVAL;
 
     /* avoid overflow on round_up(map->value_size) */
     if (attr->value_size > INT_MAX)
         return -E2BIG;
 
     return 0;
 }
 
 static struct bpf_map *array_map_alloc(union bpf_attr *attr)
 {
     bool percpu = attr->map_type == BPF_MAP_TYPE_PERCPU_ARRAY;
     int numa_node = bpf_map_attr_numa_node(attr);
     u32 elem_size, index_mask, max_entries;
     bool bypass_spec_v1 = bpf_bypass_spec_v1();
     u64 array_size, mask64;
     struct bpf_array *array;
 
     elem_size = round_up(attr->value_size, 8);
 
     max_entries = attr->max_entries;
 
     /* On 32 bit archs roundup_pow_of_two() with max_entries that has
      * upper most bit set in u32 space is undefined behavior due to
      * resulting 1U << 32, so do it manually here in u64 space.
      */
     mask64 = fls_long(max_entries - 1);
     mask64 = 1ULL << mask64;
     mask64 -= 1;
 
     index_mask = mask64;
     if (!bypass_spec_v1) {
         /* round up array size to nearest power of 2,
          * since cpu will speculate within index_mask limits
          */
         max_entries = index_mask + 1;
         /* Check for overflows. */
         if (max_entries < attr->max_entries)
             return ERR_PTR(-E2BIG);
     }
 
     array_size = sizeof(*array);
     if (percpu) {
         array_size += (u64) max_entries * sizeof(void *);
     } else {
         /* rely on vmalloc() to return page-aligned memory and
          * ensure array->value is exactly page-aligned
          */
         if (attr->map_flags & BPF_F_MMAPABLE) {
             array_size = PAGE_ALIGN(array_size);
             array_size += PAGE_ALIGN((u64) max_entries * elem_size);
         } else {
             array_size += (u64) max_entries * elem_size;
         }
     }
 
     /* allocate all map elements and zero-initialize them */
     if (attr->map_flags & BPF_F_MMAPABLE) {
         void *data;
 
         /* kmalloc'ed memory can't be mmap'ed, use explicit vmalloc */
         data = bpf_map_area_mmapable_alloc(array_size, numa_node);
         if (!data)
             return ERR_PTR(-ENOMEM);
         array = data + PAGE_ALIGN(sizeof(struct bpf_array))
             - offsetof(struct bpf_array, value);
     } else {
         array = bpf_map_area_alloc(array_size, numa_node);
     }
     if (!array)
         return ERR_PTR(-ENOMEM);
     array->index_mask = index_mask;
     array->map.bypass_spec_v1 = bypass_spec_v1;
 
     /* copy mandatory map attributes */
     bpf_map_init_from_attr(&array->map, attr);
     array->elem_size = elem_size;
 
     if (percpu && bpf_array_alloc_percpu(array)) {
         bpf_map_area_free(array);
         return ERR_PTR(-ENOMEM);
     }
 
     return &array->map;
 }
 
 static void *array_map_elem_ptr(struct bpf_array* array, u32 index)
 {
     return array->value + (u64)array->elem_size * index;
 }
 
 /* Called from syscall or from eBPF program */
 static void *array_map_lookup_elem(struct bpf_map *map, void *key)
 {
     struct bpf_array *array = container_of(map, struct bpf_array, map);
     u32 index = *(u32 *)key;
 
     if (unlikely(index >= array->map.max_entries))
         return NULL;
 
     return array->value + (u64)array->elem_size * (index & array->index_mask);
 }
 
 static int array_map_direct_value_addr(const struct bpf_map *map, u64 *imm,
                        u32 off)
 {
     struct bpf_array *array = container_of(map, struct bpf_array, map);
 
     if (map->max_entries != 1)
         return -ENOTSUPP;
     if (off >= map->value_size)
         return -EINVAL;
 
     *imm = (unsigned long)array->value;
     return 0;
 }
 
 static int array_map_direct_value_meta(const struct bpf_map *map, u64 imm,
                        u32 *off)
 {
     struct bpf_array *array = container_of(map, struct bpf_array, map);
     u64 base = (unsigned long)array->value;
     u64 range = array->elem_size;
 
     if (map->max_entries != 1)
         return -ENOTSUPP;
     if (imm < base || imm >= base + range)
         return -ENOENT;
 
     *off = imm - base;
     return 0;
 }
 
 /* emit BPF instructions equivalent to C code of array_map_lookup_elem() */
 static int array_map_gen_lookup(struct bpf_map *map, struct bpf_insn *insn_buf)
 {
     struct bpf_array *array = container_of(map, struct bpf_array, map);
     struct bpf_insn *insn = insn_buf;
     u32 elem_size = array->elem_size;
     const int ret = BPF_REG_0;
     const int map_ptr = BPF_REG_1;
     const int index = BPF_REG_2;
 
     if (map->map_flags & BPF_F_INNER_MAP)
         return -EOPNOTSUPP;
 
     *insn++ = BPF_ALU64_IMM(BPF_ADD, map_ptr, offsetof(struct bpf_array, value));
     *insn++ = BPF_LDX_MEM(BPF_W, ret, index, 0);
     if (!map->bypass_spec_v1) {
         *insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 4);
         *insn++ = BPF_ALU32_IMM(BPF_AND, ret, array->index_mask);
     } else {
         *insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 3);
     }
 
     if (is_power_of_2(elem_size)) {
         *insn++ = BPF_ALU64_IMM(BPF_LSH, ret, ilog2(elem_size));
     } else {
         *insn++ = BPF_ALU64_IMM(BPF_MUL, ret, elem_size);
     }
     *insn++ = BPF_ALU64_REG(BPF_ADD, ret, map_ptr);
     *insn++ = BPF_JMP_IMM(BPF_JA, 0, 0, 1);
     *insn++ = BPF_MOV64_IMM(ret, 0);
     return insn - insn_buf;
 }
 
 /* Called from eBPF program */
 static void *percpu_array_map_lookup_elem(struct bpf_map *map, void *key)
 {
     struct bpf_array *array = container_of(map, struct bpf_array, map);
     u32 index = *(u32 *)key;
 
     if (unlikely(index >= array->map.max_entries))
         return NULL;
 
     return this_cpu_ptr(array->pptrs[index & array->index_mask]);
 }
 
 static void *percpu_array_map_lookup_percpu_elem(struct bpf_map *map, void *key, u32 cpu)
 {
     struct bpf_array *array = container_of(map, struct bpf_array, map);
     u32 index = *(u32 *)key;
 
     if (cpu >= nr_cpu_ids)
         return NULL;
 
     if (unlikely(index >= array->map.max_entries))
         return NULL;
 
     return per_cpu_ptr(array->pptrs[index & array->index_mask], cpu);
 }
 
 int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value)
 {
     struct bpf_array *array = container_of(map, struct bpf_array, map);
     u32 index = *(u32 *)key;
     void __percpu *pptr;
     int cpu, off = 0;
     u32 size;
 
     if (unlikely(index >= array->map.max_entries))
         return -ENOENT;
 
     /* per_cpu areas are zero-filled and bpf programs can only
      * access 'value_size' of them, so copying rounded areas
      * will not leak any kernel data
      */
     size = array->elem_size;
     rcu_read_lock();
     pptr = array->pptrs[index & array->index_mask];
     for_each_possible_cpu(cpu) {
         bpf_long_memcpy(value + off, per_cpu_ptr(pptr, cpu), size);
         off += size;
     }
     rcu_read_unlock();
     return 0;
 }
 
 /* Called from syscall */
 static int array_map_get_next_key(struct bpf_map *map, void *key, void *next_key)
 {
     struct bpf_array *array = container_of(map, struct bpf_array, map);
     u32 index = key ? *(u32 *)key : U32_MAX;
     u32 *next = (u32 *)next_key;
 
     if (index >= array->map.max_entries) {
         *next = 0;
         return 0;
     }
 
     if (index == array->map.max_entries - 1)
         return -ENOENT;
 
     *next = index + 1;
     return 0;
 }
 
 static void check_and_free_fields(struct bpf_array *arr, void *val)
 {
     if (map_value_has_timer(&arr->map))
         bpf_timer_cancel_and_free(val + arr->map.timer_off);
     if (map_value_has_kptrs(&arr->map))
         bpf_map_free_kptrs(&arr->map, val);
 }
 
 /* Called from syscall or from eBPF program */
 static int array_map_update_elem(struct bpf_map *map, void *key, void *value,
                  u64 map_flags)
 {
     struct bpf_array *array = container_of(map, struct bpf_array, map);
     u32 index = *(u32 *)key;
     char *val;
 
     if (unlikely((map_flags & ~BPF_F_LOCK) > BPF_EXIST))
         /* unknown flags */
         return -EINVAL;
 
     if (unlikely(index >= array->map.max_entries))
         /* all elements were pre-allocated, cannot insert a new one */
         return -E2BIG;
 
     if (unlikely(map_flags & BPF_NOEXIST))
         /* all elements already exist */
         return -EEXIST;
 
     if (unlikely((map_flags & BPF_F_LOCK) &&
              !map_value_has_spin_lock(map)))
         return -EINVAL;
 
     if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
         memcpy(this_cpu_ptr(array->pptrs[index & array->index_mask]),
                value, map->value_size);
     } else {
         val = array->value +
             (u64)array->elem_size * (index & array->index_mask);
         if (map_flags & BPF_F_LOCK)
             copy_map_value_locked(map, val, value, false);
         else
             copy_map_value(map, val, value);
         check_and_free_fields(array, val);
     }
     return 0;
 }
 
 int bpf_percpu_array_update(struct bpf_map *map, void *key, void *value,
                 u64 map_flags)
 {
     struct bpf_array *array = container_of(map, struct bpf_array, map);
     u32 index = *(u32 *)key;
     void __percpu *pptr;
     int cpu, off = 0;
     u32 size;
 
     if (unlikely(map_flags > BPF_EXIST))
         /* unknown flags */
         return -EINVAL;
 
     if (unlikely(index >= array->map.max_entries))
         /* all elements were pre-allocated, cannot insert a new one */
         return -E2BIG;
 
     if (unlikely(map_flags == BPF_NOEXIST))
         /* all elements already exist */
         return -EEXIST;
 
     /* the user space will provide round_up(value_size, 8) bytes that
      * will be copied into per-cpu area. bpf programs can only access
      * value_size of it. During lookup the same extra bytes will be
      * returned or zeros which were zero-filled by percpu_alloc,
      * so no kernel data leaks possible
      */
     size = array->elem_size;
     rcu_read_lock();
     pptr = array->pptrs[index & array->index_mask];
     for_each_possible_cpu(cpu) {
         bpf_long_memcpy(per_cpu_ptr(pptr, cpu), value + off, size);
         off += size;
     }
     rcu_read_unlock();
     return 0;
 }
 
 /* Called from syscall or from eBPF program */
 static int array_map_delete_elem(struct bpf_map *map, void *key)
 {
     return -EINVAL;
 }
 
 static void *array_map_vmalloc_addr(struct bpf_array *array)
 {
     return (void *)round_down((unsigned long)array, PAGE_SIZE);
 }
 
 static void array_map_free_timers(struct bpf_map *map)
 {
     struct bpf_array *array = container_of(map, struct bpf_array, map);
     int i;
 
     /* We don't reset or free kptr on uref dropping to zero. */
     if (!map_value_has_timer(map))
         return;
 
     for (i = 0; i < array->map.max_entries; i++)
         bpf_timer_cancel_and_free(array_map_elem_ptr(array, i) + map->timer_off);
 }
 
 /* Called when map->refcnt goes to zero, either from workqueue or from syscall */
 static void array_map_free(struct bpf_map *map)
 {
     struct bpf_array *array = container_of(map, struct bpf_array, map);
     int i;
 
     if (map_value_has_kptrs(map)) {
         for (i = 0; i < array->map.max_entries; i++)
             bpf_map_free_kptrs(map, array_map_elem_ptr(array, i));
         bpf_map_free_kptr_off_tab(map);
     }
 
     if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY)
         bpf_array_free_percpu(array);
 
     if (array->map.map_flags & BPF_F_MMAPABLE)
         bpf_map_area_free(array_map_vmalloc_addr(array));
     else
         bpf_map_area_free(array);
 }
 
 static void array_map_seq_show_elem(struct bpf_map *map, void *key,
                     struct seq_file *m)
 {
     void *value;
 
     rcu_read_lock();
 
     value = array_map_lookup_elem(map, key);
     if (!value) {
         rcu_read_unlock();
         return;
     }
 
     if (map->btf_key_type_id)
         seq_printf(m, "%u: ", *(u32 *)key);
     btf_type_seq_show(map->btf, map->btf_value_type_id, value, m);
     seq_puts(m, "\n");
 
     rcu_read_unlock();
 }
 
 static void percpu_array_map_seq_show_elem(struct bpf_map *map, void *key,
                        struct seq_file *m)
 {
     struct bpf_array *array = container_of(map, struct bpf_array, map);
     u32 index = *(u32 *)key;
     void __percpu *pptr;
     int cpu;
 
     rcu_read_lock();
 
     seq_printf(m, "%u: {\n", *(u32 *)key);
     pptr = array->pptrs[index & array->index_mask];
     for_each_possible_cpu(cpu) {
         seq_printf(m, "\tcpu%d: ", cpu);
         btf_type_seq_show(map->btf, map->btf_value_type_id,
                   per_cpu_ptr(pptr, cpu), m);
         seq_puts(m, "\n");
     }
     seq_puts(m, "}\n");
 
     rcu_read_unlock();
 }
 
 static int array_map_check_btf(const struct bpf_map *map,
                    const struct btf *btf,
                    const struct btf_type *key_type,
                    const struct btf_type *value_type)
 {
     u32 int_data;
 
     /* One exception for keyless BTF: .bss/.data/.rodata map */
     if (btf_type_is_void(key_type)) {
         if (map->map_type != BPF_MAP_TYPE_ARRAY ||
             map->max_entries != 1)
             return -EINVAL;
 
         if (BTF_INFO_KIND(value_type->info) != BTF_KIND_DATASEC)
             return -EINVAL;
 
         return 0;
     }
 
     if (BTF_INFO_KIND(key_type->info) != BTF_KIND_INT)
         return -EINVAL;
 
     int_data = *(u32 *)(key_type + 1);
     /* bpf array can only take a u32 key. This check makes sure
      * that the btf matches the attr used during map_create.
      */
     if (BTF_INT_BITS(int_data) != 32 || BTF_INT_OFFSET(int_data))
         return -EINVAL;
 
     return 0;
 }
 
 static int array_map_mmap(struct bpf_map *map, struct vm_area_struct *vma)
 {
     struct bpf_array *array = container_of(map, struct bpf_array, map);
     pgoff_t pgoff = PAGE_ALIGN(sizeof(*array)) >> PAGE_SHIFT;
 
     if (!(map->map_flags & BPF_F_MMAPABLE))
         return -EINVAL;
 
     if (vma->vm_pgoff * PAGE_SIZE + (vma->vm_end - vma->vm_start) >
         PAGE_ALIGN((u64)array->map.max_entries * array->elem_size))
         return -EINVAL;
 
     return remap_vmalloc_range(vma, array_map_vmalloc_addr(array),
                    vma->vm_pgoff + pgoff);
 }
 
 static bool array_map_meta_equal(const struct bpf_map *meta0,
                  const struct bpf_map *meta1)
 {
     if (!bpf_map_meta_equal(meta0, meta1))
         return false;
     return meta0->map_flags & BPF_F_INNER_MAP ? true :
            meta0->max_entries == meta1->max_entries;
 }
 
 struct bpf_iter_seq_array_map_info {
     struct bpf_map *map;
     void *percpu_value_buf;
     u32 index;
 };
 
 static void *bpf_array_map_seq_start(struct seq_file *seq, loff_t *pos)
 {
     struct bpf_iter_seq_array_map_info *info = seq->private;
     struct bpf_map *map = info->map;
     struct bpf_array *array;
     u32 index;
 
     if (info->index >= map->max_entries)
         return NULL;
 
     if (*pos == 0)
         ++*pos;
     array = container_of(map, struct bpf_array, map);
     index = info->index & array->index_mask;
     if (info->percpu_value_buf)
            return array->pptrs[index];
     return array_map_elem_ptr(array, index);
 }
 
 static void *bpf_array_map_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 {
     struct bpf_iter_seq_array_map_info *info = seq->private;
     struct bpf_map *map = info->map;
     struct bpf_array *array;
     u32 index;
 
     ++*pos;
     ++info->index;
     if (info->index >= map->max_entries)
         return NULL;
 
     array = container_of(map, struct bpf_array, map);
     index = info->index & array->index_mask;
     if (info->percpu_value_buf)
            return array->pptrs[index];
     return array_map_elem_ptr(array, index);
 }
 
 static int __bpf_array_map_seq_show(struct seq_file *seq, void *v)
 {
     struct bpf_iter_seq_array_map_info *info = seq->private;
     struct bpf_iter__bpf_map_elem ctx = {};
     struct bpf_map *map = info->map;
     struct bpf_array *array = container_of(map, struct bpf_array, map);
     struct bpf_iter_meta meta;
     struct bpf_prog *prog;
     int off = 0, cpu = 0;
     void __percpu **pptr;
     u32 size;
 
     meta.seq = seq;
     prog = bpf_iter_get_info(&meta, v == NULL);
     if (!prog)
         return 0;
 
     ctx.meta = &meta;
     ctx.map = info->map;
     if (v) {
         ctx.key = &info->index;
 
         if (!info->percpu_value_buf) {
             ctx.value = v;
         } else {
             pptr = v;
             size = array->elem_size;
             for_each_possible_cpu(cpu) {
                 bpf_long_memcpy(info->percpu_value_buf + off,
                         per_cpu_ptr(pptr, cpu),
                         size);
                 off += size;
             }
             ctx.value = info->percpu_value_buf;
         }
     }
 
     return bpf_iter_run_prog(prog, &ctx);
 }
 
 static int bpf_array_map_seq_show(struct seq_file *seq, void *v)
 {
     return __bpf_array_map_seq_show(seq, v);
 }
 
 static void bpf_array_map_seq_stop(struct seq_file *seq, void *v)
 {
     if (!v)
         (void)__bpf_array_map_seq_show(seq, NULL);
 }
 
 static int bpf_iter_init_array_map(void *priv_data,
                    struct bpf_iter_aux_info *aux)
 {
     struct bpf_iter_seq_array_map_info *seq_info = priv_data;
     struct bpf_map *map = aux->map;
     struct bpf_array *array = container_of(map, struct bpf_array, map);
     void *value_buf;
     u32 buf_size;
 
     if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
         buf_size = array->elem_size * num_possible_cpus();
         value_buf = kmalloc(buf_size, GFP_USER | __GFP_NOWARN);
         if (!value_buf)
             return -ENOMEM;
 
         seq_info->percpu_value_buf = value_buf;
     }
 
     /* bpf_iter_attach_map() acquires a map uref, and the uref may be
      * released before or in the middle of iterating map elements, so
      * acquire an extra map uref for iterator.
      */
     bpf_map_inc_with_uref(map);
     seq_info->map = map;
     return 0;
 }
 
 static void bpf_iter_fini_array_map(void *priv_data)
 {
     struct bpf_iter_seq_array_map_info *seq_info = priv_data;
 
     bpf_map_put_with_uref(seq_info->map);
     kfree(seq_info->percpu_value_buf);
 }
 
 static const struct seq_operations bpf_array_map_seq_ops = {
     .start  = bpf_array_map_seq_start,
     .next   = bpf_array_map_seq_next,
     .stop   = bpf_array_map_seq_stop,
     .show   = bpf_array_map_seq_show,
 };
 
 static const struct bpf_iter_seq_info iter_seq_info = {
     .seq_ops        = &bpf_array_map_seq_ops,
     .init_seq_private   = bpf_iter_init_array_map,
     .fini_seq_private   = bpf_iter_fini_array_map,
     .seq_priv_size      = sizeof(struct bpf_iter_seq_array_map_info),
 };
 
 static int bpf_for_each_array_elem(struct bpf_map *map, bpf_callback_t callback_fn,
                    void *callback_ctx, u64 flags)
 {
     u32 i, key, num_elems = 0;
     struct bpf_array *array;
     bool is_percpu;
     u64 ret = 0;
     void *val;
 
     if (flags != 0)
         return -EINVAL;
 
     is_percpu = map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY;
     array = container_of(map, struct bpf_array, map);
     if (is_percpu)
         migrate_disable();
     for (i = 0; i < map->max_entries; i++) {
         if (is_percpu)
             val = this_cpu_ptr(array->pptrs[i]);
         else
             val = array_map_elem_ptr(array, i);
         num_elems++;
         key = i;
         ret = callback_fn((u64)(long)map, (u64)(long)&key,
                   (u64)(long)val, (u64)(long)callback_ctx, 0);
         /* return value: 0 - continue, 1 - stop and return */
         if (ret)
             break;
     }
 
     if (is_percpu)
         migrate_enable();
     return num_elems;
 }
 
 BTF_ID_LIST_SINGLE(array_map_btf_ids, struct, bpf_array)
 const struct bpf_map_ops array_map_ops = {
     .map_meta_equal = array_map_meta_equal,
     .map_alloc_check = array_map_alloc_check,
     .map_alloc = array_map_alloc,
     .map_free = array_map_free,
     .map_get_next_key = array_map_get_next_key,
     .map_release_uref = array_map_free_timers,
     .map_lookup_elem = array_map_lookup_elem,
     .map_update_elem = array_map_update_elem,
     .map_delete_elem = array_map_delete_elem,
     .map_gen_lookup = array_map_gen_lookup,
     .map_direct_value_addr = array_map_direct_value_addr,
     .map_direct_value_meta = array_map_direct_value_meta,
     .map_mmap = array_map_mmap,
     .map_seq_show_elem = array_map_seq_show_elem,
     .map_check_btf = array_map_check_btf,
     .map_lookup_batch = generic_map_lookup_batch,
     .map_update_batch = generic_map_update_batch,
     .map_set_for_each_callback_args = map_set_for_each_callback_args,
     .map_for_each_callback = bpf_for_each_array_elem,
     .map_btf_id = &array_map_btf_ids[0],
     .iter_seq_info = &iter_seq_info,
 };
 
 const struct bpf_map_ops percpu_array_map_ops = {
     .map_meta_equal = bpf_map_meta_equal,
     .map_alloc_check = array_map_alloc_check,
     .map_alloc = array_map_alloc,
     .map_free = array_map_free,
     .map_get_next_key = array_map_get_next_key,
     .map_lookup_elem = percpu_array_map_lookup_elem,
     .map_update_elem = array_map_update_elem,
     .map_delete_elem = array_map_delete_elem,
     .map_lookup_percpu_elem = percpu_array_map_lookup_percpu_elem,
     .map_seq_show_elem = percpu_array_map_seq_show_elem,
     .map_check_btf = array_map_check_btf,
     .map_lookup_batch = generic_map_lookup_batch,
     .map_update_batch = generic_map_update_batch,
     .map_set_for_each_callback_args = map_set_for_each_callback_args,
     .map_for_each_callback = bpf_for_each_array_elem,
     .map_btf_id = &array_map_btf_ids[0],
     .iter_seq_info = &iter_seq_info,
 };
 
 static int fd_array_map_alloc_check(union bpf_attr *attr)
 {
     /* only file descriptors can be stored in this type of map */
     if (attr->value_size != sizeof(u32))
         return -EINVAL;
     /* Program read-only/write-only not supported for special maps yet. */
     if (attr->map_flags & (BPF_F_RDONLY_PROG | BPF_F_WRONLY_PROG))
         return -EINVAL;
     return array_map_alloc_check(attr);
 }
 
 static void fd_array_map_free(struct bpf_map *map)
 {
     struct bpf_array *array = container_of(map, struct bpf_array, map);
     int i;
 
     /* make sure it's empty */
     for (i = 0; i < array->map.max_entries; i++)
         BUG_ON(array->ptrs[i] != NULL);
 
     bpf_map_area_free(array);
 }
 
 static void *fd_array_map_lookup_elem(struct bpf_map *map, void *key)
 {
     return ERR_PTR(-EOPNOTSUPP);
 }
 
 /* only called from syscall */
 int bpf_fd_array_map_lookup_elem(struct bpf_map *map, void *key, u32 *value)
 {
     void **elem, *ptr;
     int ret =  0;
 
     if (!map->ops->map_fd_sys_lookup_elem)
         return -ENOTSUPP;
 
     rcu_read_lock();
     elem = array_map_lookup_elem(map, key);
     if (elem && (ptr = READ_ONCE(*elem)))
         *value = map->ops->map_fd_sys_lookup_elem(ptr);
     else
         ret = -ENOENT;
     rcu_read_unlock();
 
     return ret;
 }
 
 /* only called from syscall */
 int bpf_fd_array_map_update_elem(struct bpf_map *map, struct file *map_file,
                  void *key, void *value, u64 map_flags)
 {
     struct bpf_array *array = container_of(map, struct bpf_array, map);
     void *new_ptr, *old_ptr;
     u32 index = *(u32 *)key, ufd;
 
     if (map_flags != BPF_ANY)
         return -EINVAL;
 
     if (index >= array->map.max_entries)
         return -E2BIG;
 
     ufd = *(u32 *)value;
     new_ptr = map->ops->map_fd_get_ptr(map, map_file, ufd);
     if (IS_ERR(new_ptr))
         return PTR_ERR(new_ptr);
 
     if (map->ops->map_poke_run) {
         mutex_lock(&array->aux->poke_mutex);
         old_ptr = xchg(array->ptrs + index, new_ptr);
         map->ops->map_poke_run(map, index, old_ptr, new_ptr);
         mutex_unlock(&array->aux->poke_mutex);
     } else {
         old_ptr = xchg(array->ptrs + index, new_ptr);
     }
 
     if (old_ptr)
         map->ops->map_fd_put_ptr(old_ptr);
     return 0;
 }
 
 static int fd_array_map_delete_elem(struct bpf_map *map, void *key)
 {
     struct bpf_array *array = container_of(map, struct bpf_array, map);
     void *old_ptr;
     u32 index = *(u32 *)key;
 
     if (index >= array->map.max_entries)
         return -E2BIG;
 
     if (map->ops->map_poke_run) {
         mutex_lock(&array->aux->poke_mutex);
         old_ptr = xchg(array->ptrs + index, NULL);
         map->ops->map_poke_run(map, index, old_ptr, NULL);
         mutex_unlock(&array->aux->poke_mutex);
     } else {
         old_ptr = xchg(array->ptrs + index, NULL);
     }
 
     if (old_ptr) {
         map->ops->map_fd_put_ptr(old_ptr);
         return 0;
     } else {
         return -ENOENT;
     }
 }
 
 static void *prog_fd_array_get_ptr(struct bpf_map *map,
                    struct file *map_file, int fd)
 {
     struct bpf_prog *prog = bpf_prog_get(fd);
 
     if (IS_ERR(prog))
         return prog;
 
     if (!bpf_prog_map_compatible(map, prog)) {
         bpf_prog_put(prog);
         return ERR_PTR(-EINVAL);
     }
 
     return prog;
 }
 
 static void prog_fd_array_put_ptr(void *ptr)
 {
     bpf_prog_put(ptr);
 }
 
 static u32 prog_fd_array_sys_lookup_elem(void *ptr)
 {
     return ((struct bpf_prog *)ptr)->aux->id;
 }
 
 /* decrement refcnt of all bpf_progs that are stored in this map */
 static void bpf_fd_array_map_clear(struct bpf_map *map)
 {
     struct bpf_array *array = container_of(map, struct bpf_array, map);
     int i;
 
     for (i = 0; i < array->map.max_entries; i++)
         fd_array_map_delete_elem(map, &i);
 }
 
 static void prog_array_map_seq_show_elem(struct bpf_map *map, void *key,
                      struct seq_file *m)
 {
     void **elem, *ptr;
     u32 prog_id;
 
     rcu_read_lock();
 
     elem = array_map_lookup_elem(map, key);
     if (elem) {
         ptr = READ_ONCE(*elem);
         if (ptr) {
             seq_printf(m, "%u: ", *(u32 *)key);
             prog_id = prog_fd_array_sys_lookup_elem(ptr);
             btf_type_seq_show(map->btf, map->btf_value_type_id,
                       &prog_id, m);
             seq_puts(m, "\n");
         }
     }
 
     rcu_read_unlock();
 }
 
 struct prog_poke_elem {
     struct list_head list;
     struct bpf_prog_aux *aux;
 };
 
 static int prog_array_map_poke_track(struct bpf_map *map,
                      struct bpf_prog_aux *prog_aux)
 {
     struct prog_poke_elem *elem;
     struct bpf_array_aux *aux;
     int ret = 0;
 
     aux = container_of(map, struct bpf_array, map)->aux;
     mutex_lock(&aux->poke_mutex);
     list_for_each_entry(elem, &aux->poke_progs, list) {
         if (elem->aux == prog_aux)
             goto out;
     }
 
     elem = kmalloc(sizeof(*elem), GFP_KERNEL);
     if (!elem) {
         ret = -ENOMEM;
         goto out;
     }
 
     INIT_LIST_HEAD(&elem->list);
     /* We must track the program's aux info at this point in time
      * since the program pointer itself may not be stable yet, see
      * also comment in prog_array_map_poke_run().
      */
     elem->aux = prog_aux;
 
     list_add_tail(&elem->list, &aux->poke_progs);
 out:
     mutex_unlock(&aux->poke_mutex);
     return ret;
 }
 
 static void prog_array_map_poke_untrack(struct bpf_map *map,
                     struct bpf_prog_aux *prog_aux)
 {
     struct prog_poke_elem *elem, *tmp;
     struct bpf_array_aux *aux;
 
     aux = container_of(map, struct bpf_array, map)->aux;
     mutex_lock(&aux->poke_mutex);
     list_for_each_entry_safe(elem, tmp, &aux->poke_progs, list) {
         if (elem->aux == prog_aux) {
             list_del_init(&elem->list);
             kfree(elem);
             break;
         }
     }
     mutex_unlock(&aux->poke_mutex);
 }
 
 static void prog_array_map_poke_run(struct bpf_map *map, u32 key,
                     struct bpf_prog *old,
                     struct bpf_prog *new)
 {
     u8 *old_addr, *new_addr, *old_bypass_addr;
     struct prog_poke_elem *elem;
     struct bpf_array_aux *aux;
 
     aux = container_of(map, struct bpf_array, map)->aux;
     WARN_ON_ONCE(!mutex_is_locked(&aux->poke_mutex));
 
     list_for_each_entry(elem, &aux->poke_progs, list) {
         struct bpf_jit_poke_descriptor *poke;
         int i, ret;
 
         for (i = 0; i < elem->aux->size_poke_tab; i++) {
             poke = &elem->aux->poke_tab[i];
 
             /* Few things to be aware of:
              *
              * 1) We can only ever access aux in this context, but
              *    not aux->prog since it might not be stable yet and
              *    there could be danger of use after free otherwise.
              * 2) Initially when we start tracking aux, the program
              *    is not JITed yet and also does not have a kallsyms
              *    entry. We skip these as poke->tailcall_target_stable
              *    is not active yet. The JIT will do the final fixup
              *    before setting it stable. The various
              *    poke->tailcall_target_stable are successively
              *    activated, so tail call updates can arrive from here
              *    while JIT is still finishing its final fixup for
              *    non-activated poke entries.
              * 3) On program teardown, the program's kallsym entry gets
              *    removed out of RCU callback, but we can only untrack
              *    from sleepable context, therefore bpf_arch_text_poke()
              *    might not see that this is in BPF text section and
              *    bails out with -EINVAL. As these are unreachable since
              *    RCU grace period already passed, we simply skip them.
              * 4) Also programs reaching refcount of zero while patching
              *    is in progress is okay since we're protected under
              *    poke_mutex and untrack the programs before the JIT
              *    buffer is freed. When we're still in the middle of
              *    patching and suddenly kallsyms entry of the program
              *    gets evicted, we just skip the rest which is fine due
              *    to point 3).
              * 5) Any other error happening below from bpf_arch_text_poke()
              *    is a unexpected bug.
              */
             if (!READ_ONCE(poke->tailcall_target_stable))
                 continue;
             if (poke->reason != BPF_POKE_REASON_TAIL_CALL)
                 continue;
             if (poke->tail_call.map != map ||
                 poke->tail_call.key != key)
                 continue;
 
             old_bypass_addr = old ? NULL : poke->bypass_addr;
             old_addr = old ? (u8 *)old->bpf_func + poke->adj_off : NULL;
             new_addr = new ? (u8 *)new->bpf_func + poke->adj_off : NULL;
 
             if (new) {
                 ret = bpf_arch_text_poke(poke->tailcall_target,
                              BPF_MOD_JUMP,
                              old_addr, new_addr);
                 BUG_ON(ret < 0 && ret != -EINVAL);
                 if (!old) {
                     ret = bpf_arch_text_poke(poke->tailcall_bypass,
                                  BPF_MOD_JUMP,
                                  poke->bypass_addr,
                                  NULL);
                     BUG_ON(ret < 0 && ret != -EINVAL);
                 }
             } else {
                 ret = bpf_arch_text_poke(poke->tailcall_bypass,
                              BPF_MOD_JUMP,
                              old_bypass_addr,
                              poke->bypass_addr);
                 BUG_ON(ret < 0 && ret != -EINVAL);
                 /* let other CPUs finish the execution of program
                  * so that it will not possible to expose them
                  * to invalid nop, stack unwind, nop state
                  */
                 if (!ret)
                     synchronize_rcu();
                 ret = bpf_arch_text_poke(poke->tailcall_target,
                              BPF_MOD_JUMP,
                              old_addr, NULL);
                 BUG_ON(ret < 0 && ret != -EINVAL);
             }
         }
     }
 }
 
 static void prog_array_map_clear_deferred(struct work_struct *work)
 {
     struct bpf_map *map = container_of(work, struct bpf_array_aux,
                        work)->map;
     bpf_fd_array_map_clear(map);
     bpf_map_put(map);
 }
 
 static void prog_array_map_clear(struct bpf_map *map)
 {
     struct bpf_array_aux *aux = container_of(map, struct bpf_array,
                          map)->aux;
     bpf_map_inc(map);
     schedule_work(&aux->work);
 }
 
 static struct bpf_map *prog_array_map_alloc(union bpf_attr *attr)
 {
     struct bpf_array_aux *aux;
     struct bpf_map *map;
 
     aux = kzalloc(sizeof(*aux), GFP_KERNEL_ACCOUNT);
     if (!aux)
         return ERR_PTR(-ENOMEM);
 
     INIT_WORK(&aux->work, prog_array_map_clear_deferred);
     INIT_LIST_HEAD(&aux->poke_progs);
     mutex_init(&aux->poke_mutex);
 
     map = array_map_alloc(attr);
     if (IS_ERR(map)) {
         kfree(aux);
         return map;
     }
 
     container_of(map, struct bpf_array, map)->aux = aux;
     aux->map = map;
 
     return map;
 }
 
 static void prog_array_map_free(struct bpf_map *map)
 {
     struct prog_poke_elem *elem, *tmp;
     struct bpf_array_aux *aux;
 
     aux = container_of(map, struct bpf_array, map)->aux;
     list_for_each_entry_safe(elem, tmp, &aux->poke_progs, list) {
         list_del_init(&elem->list);
         kfree(elem);
     }
     kfree(aux);
     fd_array_map_free(map);
 }
 
 /* prog_array->aux->{type,jited} is a runtime binding.
  * Doing static check alone in the verifier is not enough.
  * Thus, prog_array_map cannot be used as an inner_map
  * and map_meta_equal is not implemented.
  */
 const struct bpf_map_ops prog_array_map_ops = {
     .map_alloc_check = fd_array_map_alloc_check,
     .map_alloc = prog_array_map_alloc,
     .map_free = prog_array_map_free,
     .map_poke_track = prog_array_map_poke_track,
     .map_poke_untrack = prog_array_map_poke_untrack,
     .map_poke_run = prog_array_map_poke_run,
     .map_get_next_key = array_map_get_next_key,
     .map_lookup_elem = fd_array_map_lookup_elem,
     .map_delete_elem = fd_array_map_delete_elem,
     .map_fd_get_ptr = prog_fd_array_get_ptr,
     .map_fd_put_ptr = prog_fd_array_put_ptr,
     .map_fd_sys_lookup_elem = prog_fd_array_sys_lookup_elem,
     .map_release_uref = prog_array_map_clear,
     .map_seq_show_elem = prog_array_map_seq_show_elem,
     .map_btf_id = &array_map_btf_ids[0],
 };
 
 static struct bpf_event_entry *bpf_event_entry_gen(struct file *perf_file,
                            struct file *map_file)
 {
     struct bpf_event_entry *ee;
 
     ee = kzalloc(sizeof(*ee), GFP_ATOMIC);
     if (ee) {
         ee->event = perf_file->private_data;
         ee->perf_file = perf_file;
         ee->map_file = map_file;
     }
 
     return ee;
 }
 
 static void __bpf_event_entry_free(struct rcu_head *rcu)
 {
     struct bpf_event_entry *ee;
 
     ee = container_of(rcu, struct bpf_event_entry, rcu);
     fput(ee->perf_file);
     kfree(ee);
 }
 
 static void bpf_event_entry_free_rcu(struct bpf_event_entry *ee)
 {
     call_rcu(&ee->rcu, __bpf_event_entry_free);
 }
 
 static void *perf_event_fd_array_get_ptr(struct bpf_map *map,
                      struct file *map_file, int fd)
 {
     struct bpf_event_entry *ee;
     struct perf_event *event;
     struct file *perf_file;
     u64 value;
 
     perf_file = perf_event_get(fd);
     if (IS_ERR(perf_file))
         return perf_file;
 
     ee = ERR_PTR(-EOPNOTSUPP);
     event = perf_file->private_data;
     if (perf_event_read_local(event, &value, NULL, NULL) == -EOPNOTSUPP)
         goto err_out;
 
     ee = bpf_event_entry_gen(perf_file, map_file);
     if (ee)
         return ee;
     ee = ERR_PTR(-ENOMEM);
 err_out:
     fput(perf_file);
     return ee;
 }
 
 static void perf_event_fd_array_put_ptr(void *ptr)
 {
     bpf_event_entry_free_rcu(ptr);
 }
 
 static void perf_event_fd_array_release(struct bpf_map *map,
                     struct file *map_file)
 {
     struct bpf_array *array = container_of(map, struct bpf_array, map);
     struct bpf_event_entry *ee;
     int i;
 
     if (map->map_flags & BPF_F_PRESERVE_ELEMS)
         return;
 
     rcu_read_lock();
     for (i = 0; i < array->map.max_entries; i++) {
         ee = READ_ONCE(array->ptrs[i]);
         if (ee && ee->map_file == map_file)
             fd_array_map_delete_elem(map, &i);
     }
     rcu_read_unlock();
 }
 
 static void perf_event_fd_array_map_free(struct bpf_map *map)
 {
     if (map->map_flags & BPF_F_PRESERVE_ELEMS)
         bpf_fd_array_map_clear(map);
     fd_array_map_free(map);
 }
 
 const struct bpf_map_ops perf_event_array_map_ops = {
     .map_meta_equal = bpf_map_meta_equal,
     .map_alloc_check = fd_array_map_alloc_check,
     .map_alloc = array_map_alloc,
     .map_free = perf_event_fd_array_map_free,
     .map_get_next_key = array_map_get_next_key,
     .map_lookup_elem = fd_array_map_lookup_elem,
     .map_delete_elem = fd_array_map_delete_elem,
     .map_fd_get_ptr = perf_event_fd_array_get_ptr,
     .map_fd_put_ptr = perf_event_fd_array_put_ptr,
     .map_release = perf_event_fd_array_release,
     .map_check_btf = map_check_no_btf,
     .map_btf_id = &array_map_btf_ids[0],
 };
 
 #ifdef CONFIG_CGROUPS
 static void *cgroup_fd_array_get_ptr(struct bpf_map *map,
                      struct file *map_file /* not used */,
                      int fd)
 {
     return cgroup_get_from_fd(fd);
 }
 
 static void cgroup_fd_array_put_ptr(void *ptr)
 {
     /* cgroup_put free cgrp after a rcu grace period */
     cgroup_put(ptr);
 }
 
 static void cgroup_fd_array_free(struct bpf_map *map)
 {
     bpf_fd_array_map_clear(map);
     fd_array_map_free(map);
 }
 
 const struct bpf_map_ops cgroup_array_map_ops = {
     .map_meta_equal = bpf_map_meta_equal,
     .map_alloc_check = fd_array_map_alloc_check,
     .map_alloc = array_map_alloc,
     .map_free = cgroup_fd_array_free,
     .map_get_next_key = array_map_get_next_key,
     .map_lookup_elem = fd_array_map_lookup_elem,
     .map_delete_elem = fd_array_map_delete_elem,
     .map_fd_get_ptr = cgroup_fd_array_get_ptr,
     .map_fd_put_ptr = cgroup_fd_array_put_ptr,
     .map_check_btf = map_check_no_btf,
     .map_btf_id = &array_map_btf_ids[0],
 };
 #endif
 
 static struct bpf_map *array_of_map_alloc(union bpf_attr *attr)
 {
     struct bpf_map *map, *inner_map_meta;
 
     inner_map_meta = bpf_map_meta_alloc(attr->inner_map_fd);
     if (IS_ERR(inner_map_meta))
         return inner_map_meta;
 
     map = array_map_alloc(attr);
     if (IS_ERR(map)) {
         bpf_map_meta_free(inner_map_meta);
         return map;
     }
 
     map->inner_map_meta = inner_map_meta;
 
     return map;
 }
 
 static void array_of_map_free(struct bpf_map *map)
 {
     /* map->inner_map_meta is only accessed by syscall which
      * is protected by fdget/fdput.
      */
     bpf_map_meta_free(map->inner_map_meta);
     bpf_fd_array_map_clear(map);
     fd_array_map_free(map);
 }
 
 static void *array_of_map_lookup_elem(struct bpf_map *map, void *key)
 {
     struct bpf_map **inner_map = array_map_lookup_elem(map, key);
 
     if (!inner_map)
         return NULL;
 
     return READ_ONCE(*inner_map);
 }
 
 static int array_of_map_gen_lookup(struct bpf_map *map,
                    struct bpf_insn *insn_buf)
 {
     struct bpf_array *array = container_of(map, struct bpf_array, map);
     u32 elem_size = array->elem_size;
     struct bpf_insn *insn = insn_buf;
     const int ret = BPF_REG_0;
     const int map_ptr = BPF_REG_1;
     const int index = BPF_REG_2;
 
     *insn++ = BPF_ALU64_IMM(BPF_ADD, map_ptr, offsetof(struct bpf_array, value));
     *insn++ = BPF_LDX_MEM(BPF_W, ret, index, 0);
     if (!map->bypass_spec_v1) {
         *insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 6);
         *insn++ = BPF_ALU32_IMM(BPF_AND, ret, array->index_mask);
     } else {
         *insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 5);
     }
     if (is_power_of_2(elem_size))
         *insn++ = BPF_ALU64_IMM(BPF_LSH, ret, ilog2(elem_size));
     else
         *insn++ = BPF_ALU64_IMM(BPF_MUL, ret, elem_size);
     *insn++ = BPF_ALU64_REG(BPF_ADD, ret, map_ptr);
     *insn++ = BPF_LDX_MEM(BPF_DW, ret, ret, 0);
     *insn++ = BPF_JMP_IMM(BPF_JEQ, ret, 0, 1);
     *insn++ = BPF_JMP_IMM(BPF_JA, 0, 0, 1);
     *insn++ = BPF_MOV64_IMM(ret, 0);
 
     return insn - insn_buf;
 }
 
 const struct bpf_map_ops array_of_maps_map_ops = {
     .map_alloc_check = fd_array_map_alloc_check,
     .map_alloc = array_of_map_alloc,
     .map_free = array_of_map_free,
     .map_get_next_key = array_map_get_next_key,
     .map_lookup_elem = array_of_map_lookup_elem,
     .map_delete_elem = fd_array_map_delete_elem,
     .map_fd_get_ptr = bpf_map_fd_get_ptr,
     .map_fd_put_ptr = bpf_map_fd_put_ptr,
     .map_fd_sys_lookup_elem = bpf_map_fd_sys_lookup_elem,
     .map_gen_lookup = array_of_map_gen_lookup,
     .map_lookup_batch = generic_map_lookup_batch,
     .map_update_batch = generic_map_update_batch,
     .map_check_btf = map_check_no_btf,
     .map_btf_id = &array_map_btf_ids[0],
 };

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