[PATCH] bpf: devmap: pass on return value of bpf_map_precharge_memlock

[Tobias Klauser]

If bpf_map_precharge_memlock in dev_map_alloc, -ENOMEM is returned
regardless of the actual error produced by bpf_map_precharge_memlock.
Fix it by passing on the error returned by bpf_map_precharge_memlock.

Also return -EINVAL instead of -ENOMEM if the page count overflow check
fails.

This makes dev_map_alloc match the behavior of other bpf maps' alloc
functions wrt. return values.

Signed-off-by: Tobias Klauser <tklau...@distanz.ch>
---
 kernel/bpf/devmap.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c
index 959c9a07f318..e093d9a2c4dd 100644
--- a/kernel/bpf/devmap.c
+++ b/kernel/bpf/devmap.c
@@ -75,8 +75,8 @@ static u64 dev_map_bitmap_size(const union bpf_attr *attr)
 static struct bpf_map *dev_map_alloc(union bpf_attr *attr)
 {
        struct bpf_dtab *dtab;
+       int err = -EINVAL;
        u64 cost;
-       int err;
 
        /* check sanity of attributes */
        if (attr->max_entries == 0 || attr->key_size != 4 ||
@@ -108,6 +108,8 @@ static struct bpf_map *dev_map_alloc(union bpf_attr *attr)
        if (err)
                goto free_dtab;
 
+       err = -ENOMEM;
+
        /* A per cpu bitfield with a bit per possible net device */
        dtab->flush_needed = __alloc_percpu(dev_map_bitmap_size(attr),
                                            __alignof__(unsigned long));
@@ -128,7 +130,7 @@ static struct bpf_map *dev_map_alloc(union bpf_attr *attr)
 free_dtab:
        free_percpu(dtab->flush_needed);
        kfree(dtab);
-       return ERR_PTR(-ENOMEM);
+       return ERR_PTR(err);
 }
 
 static void dev_map_free(struct bpf_map *map)
-- 
2.13.0