diff options
Diffstat (limited to 'kernel/bpf/map_in_map.c')
| -rw-r--r-- | kernel/bpf/map_in_map.c | 82 |
1 files changed, 51 insertions, 31 deletions
diff --git a/kernel/bpf/map_in_map.c b/kernel/bpf/map_in_map.c index 39ab0b68cade..645bd30bc9a9 100644 --- a/kernel/bpf/map_in_map.c +++ b/kernel/bpf/map_in_map.c @@ -3,6 +3,7 @@ */ #include <linux/slab.h> #include <linux/bpf.h> +#include <linux/btf.h> #include "map_in_map.h" @@ -10,61 +11,72 @@ struct bpf_map *bpf_map_meta_alloc(int inner_map_ufd) { struct bpf_map *inner_map, *inner_map_meta; u32 inner_map_meta_size; - struct fd f; + CLASS(fd, f)(inner_map_ufd); - f = fdget(inner_map_ufd); inner_map = __bpf_map_get(f); if (IS_ERR(inner_map)) return inner_map; /* Does not support >1 level map-in-map */ - if (inner_map->inner_map_meta) { - fdput(f); + if (inner_map->inner_map_meta) return ERR_PTR(-EINVAL); - } - if (!inner_map->ops->map_meta_equal) { - fdput(f); + if (!inner_map->ops->map_meta_equal) return ERR_PTR(-ENOTSUPP); - } - - if (map_value_has_spin_lock(inner_map)) { - fdput(f); - return ERR_PTR(-ENOTSUPP); - } inner_map_meta_size = sizeof(*inner_map_meta); /* In some cases verifier needs to access beyond just base map. */ - if (inner_map->ops == &array_map_ops) + if (inner_map->ops == &array_map_ops || inner_map->ops == &percpu_array_map_ops) inner_map_meta_size = sizeof(struct bpf_array); inner_map_meta = kzalloc(inner_map_meta_size, GFP_USER); - if (!inner_map_meta) { - fdput(f); + if (!inner_map_meta) return ERR_PTR(-ENOMEM); - } inner_map_meta->map_type = inner_map->map_type; inner_map_meta->key_size = inner_map->key_size; inner_map_meta->value_size = inner_map->value_size; inner_map_meta->map_flags = inner_map->map_flags; inner_map_meta->max_entries = inner_map->max_entries; - inner_map_meta->spin_lock_off = inner_map->spin_lock_off; + + inner_map_meta->record = btf_record_dup(inner_map->record); + if (IS_ERR(inner_map_meta->record)) { + /* btf_record_dup returns NULL or valid pointer in case of + * invalid/empty/valid, but ERR_PTR in case of errors. During + * equality NULL or IS_ERR is equivalent. + */ + struct bpf_map *ret = ERR_CAST(inner_map_meta->record); + kfree(inner_map_meta); + return ret; + } + /* Note: We must use the same BTF, as we also used btf_record_dup above + * which relies on BTF being same for both maps, as some members like + * record->fields.list_head have pointers like value_rec pointing into + * inner_map->btf. + */ + if (inner_map->btf) { + btf_get(inner_map->btf); + inner_map_meta->btf = inner_map->btf; + } /* Misc members not needed in bpf_map_meta_equal() check. */ inner_map_meta->ops = inner_map->ops; - if (inner_map->ops == &array_map_ops) { + if (inner_map->ops == &array_map_ops || inner_map->ops == &percpu_array_map_ops) { + struct bpf_array *inner_array_meta = + container_of(inner_map_meta, struct bpf_array, map); + struct bpf_array *inner_array = container_of(inner_map, struct bpf_array, map); + + inner_array_meta->index_mask = inner_array->index_mask; + inner_array_meta->elem_size = inner_array->elem_size; inner_map_meta->bypass_spec_v1 = inner_map->bypass_spec_v1; - container_of(inner_map_meta, struct bpf_array, map)->index_mask = - container_of(inner_map, struct bpf_array, map)->index_mask; } - - fdput(f); return inner_map_meta; } void bpf_map_meta_free(struct bpf_map *map_meta) { + bpf_map_free_record(map_meta); + btf_put(map_meta->btf); kfree(map_meta); } @@ -75,7 +87,8 @@ bool bpf_map_meta_equal(const struct bpf_map *meta0, return meta0->map_type == meta1->map_type && meta0->key_size == meta1->key_size && meta0->value_size == meta1->value_size && - meta0->map_flags == meta1->map_flags; + meta0->map_flags == meta1->map_flags && + btf_record_equal(meta0->record, meta1->record); } void *bpf_map_fd_get_ptr(struct bpf_map *map, @@ -83,9 +96,8 @@ void *bpf_map_fd_get_ptr(struct bpf_map *map, int ufd) { struct bpf_map *inner_map, *inner_map_meta; - struct fd f; + CLASS(fd, f)(ufd); - f = fdget(ufd); inner_map = __bpf_map_get(f); if (IS_ERR(inner_map)) return inner_map; @@ -96,16 +108,24 @@ void *bpf_map_fd_get_ptr(struct bpf_map *map, else inner_map = ERR_PTR(-EINVAL); - fdput(f); return inner_map; } -void bpf_map_fd_put_ptr(void *ptr) +void bpf_map_fd_put_ptr(struct bpf_map *map, void *ptr, bool need_defer) { - /* ptr->ops->map_free() has to go through one - * rcu grace period by itself. + struct bpf_map *inner_map = ptr; + + /* Defer the freeing of inner map according to the sleepable attribute + * of bpf program which owns the outer map, so unnecessary waiting for + * RCU tasks trace grace period can be avoided. */ - bpf_map_put(ptr); + if (need_defer) { + if (atomic64_read(&map->sleepable_refcnt)) + WRITE_ONCE(inner_map->free_after_mult_rcu_gp, true); + else + WRITE_ONCE(inner_map->free_after_rcu_gp, true); + } + bpf_map_put(inner_map); } u32 bpf_map_fd_sys_lookup_elem(void *ptr) |