diff options
| author | Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp> | 2018-10-09 10:04:49 +0900 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2018-10-09 21:52:20 -0700 |
| commit | 509db2833e0ddac7faf6e7d2dd6e7f85c98fbee0 (patch) | |
| tree | 3f3c6e718a575fc14d2292a0d08733c0307e3ad2 /kernel/bpf/syscall.c | |
| parent | 8af03d1ae2e154a8be3631e8694b87007e1bdbc2 (diff) | |
| download | lwn-509db2833e0ddac7faf6e7d2dd6e7f85c98fbee0.tar.gz lwn-509db2833e0ddac7faf6e7d2dd6e7f85c98fbee0.zip | |
bpf: error handling when map_lookup_elem isn't supported
The error value returned by map_lookup_elem doesn't differentiate
whether lookup was failed because of invalid key or lookup is not
supported.
Lets add handling for -EOPNOTSUPP return value of map_lookup_elem()
method of map, with expectation from map's implementation that it
should return -EOPNOTSUPP if lookup is not supported.
The errno for bpf syscall for BPF_MAP_LOOKUP_ELEM command will be set
to EOPNOTSUPP if map lookup is not supported.
Signed-off-by: Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'kernel/bpf/syscall.c')
| -rw-r--r-- | kernel/bpf/syscall.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 5742df21598c..4f416234251f 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -719,10 +719,15 @@ static int map_lookup_elem(union bpf_attr *attr) } else { rcu_read_lock(); ptr = map->ops->map_lookup_elem(map, key); - if (ptr) + if (IS_ERR(ptr)) { + err = PTR_ERR(ptr); + } else if (!ptr) { + err = -ENOENT; + } else { + err = 0; memcpy(value, ptr, value_size); + } rcu_read_unlock(); - err = ptr ? 0 : -ENOENT; } if (err) |