5.10-stable review patch. If anyone has any objections, please let me know.
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From: Pu Lehui pulehui@huawei.com
This reverts commit 70294d8bc31f3b7789e5e32f757aa9344556d964 which is commit 844f157f6c0a905d039d2e20212ab3231f2e5eaf upstream.
Commit 70294d8bc31f ("bpf: Eliminate rlimit-based memory accounting for devmap maps") is part of the v5.11+ base mechanism of memcg-based memory accounting[0]. The commit cannot be independently backported to the 5.10 stable branch, otherwise the related memory when creating devmap will be unrestricted. Let's roll back to rlimit-based memory accounting mode for devmap.
Link: https://lore.kernel.org/bpf/20201201215900.3569844-1-guro@fb.com [0] Signed-off-by: Pu Lehui pulehui@huawei.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- kernel/bpf/devmap.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-)
--- a/kernel/bpf/devmap.c +++ b/kernel/bpf/devmap.c @@ -109,6 +109,8 @@ static inline struct hlist_head *dev_map static int dev_map_init_map(struct bpf_dtab *dtab, union bpf_attr *attr) { u32 valsize = attr->value_size; + u64 cost = 0; + int err;
/* check sanity of attributes. 2 value sizes supported: * 4 bytes: ifindex @@ -133,13 +135,21 @@ static int dev_map_init_map(struct bpf_d
if (!dtab->n_buckets) /* Overflow check */ return -EINVAL; + cost += (u64) sizeof(struct hlist_head) * dtab->n_buckets; + } else { + cost += (u64) dtab->map.max_entries * sizeof(struct bpf_dtab_netdev *); }
+ /* if map size is larger than memlock limit, reject it */ + err = bpf_map_charge_init(&dtab->map.memory, cost); + if (err) + return -EINVAL; + if (attr->map_type == BPF_MAP_TYPE_DEVMAP_HASH) { dtab->dev_index_head = dev_map_create_hash(dtab->n_buckets, dtab->map.numa_node); if (!dtab->dev_index_head) - return -ENOMEM; + goto free_charge;
spin_lock_init(&dtab->index_lock); } else { @@ -147,10 +157,14 @@ static int dev_map_init_map(struct bpf_d sizeof(struct bpf_dtab_netdev *), dtab->map.numa_node); if (!dtab->netdev_map) - return -ENOMEM; + goto free_charge; }
return 0; + +free_charge: + bpf_map_charge_finish(&dtab->map.memory); + return -ENOMEM; }
static struct bpf_map *dev_map_alloc(union bpf_attr *attr)