5.10-stable review patch. If anyone has any objections, please let me know.
------------------
From: Pu Lehui <pulehui@xxxxxxxxxx>
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@xxxxxx [0]
Signed-off-by: Pu Lehui <pulehui@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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)
