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| author |   Stanislav Fomichev <sdf@google.com> | 2018-11-19 14:49:01 -0800 |
|---|---|---|
| committer |   Daniel Borkmann <daniel@iogearbox.net> | 2018-11-20 00:49:32 +0100 |
| commit | 23499442c319412aa8e54e7a939e2eb531bdd77d (patch) | |
| tree | 6bfd2e191914a24c538ed5d6b850cf05bd4dd836 /tools/lib | |
| parent | bpf: fix null pointer dereference on pointer offload (diff) | |
| download | linux-dev-23499442c319412aa8e54e7a939e2eb531bdd77d.tar.xz linux-dev-23499442c319412aa8e54e7a939e2eb531bdd77d.zip | |
bpf: libbpf: retry map creation without the name
Since commit 88cda1c9da02 ("bpf: libbpf: Provide basic API support
to specify BPF obj name"), libbpf unconditionally sets bpf_attr->name
for maps. Pre v4.14 kernels don't know about map names and return an
error about unexpected non-zero data. Retry sys_bpf without a map
name to cover older kernels.
v2 changes:
* check for errno == EINVAL as suggested by Daniel Borkmann
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Diffstat (limited to 'tools/lib')
| -rw-r--r-- | tools/lib/bpf/bpf.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index 03f9bcc4ef50..961e1b9fc592 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -69,6 +69,7 @@ int bpf_create_map_xattr(const struct bpf_create_map_attr *create_attr) { __u32 name_len = create_attr->name ? strlen(create_attr->name) : 0; union bpf_attr attr; + int ret; memset(&attr, '\0', sizeof(attr)); @@ -86,7 +87,15 @@ int bpf_create_map_xattr(const struct bpf_create_map_attr *create_attr) attr.map_ifindex = create_attr->map_ifindex; attr.inner_map_fd = create_attr->inner_map_fd; - return sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr)); + ret = sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr)); + if (ret < 0 && errno == EINVAL && create_attr->name) { + /* Retry the same syscall, but without the name. + * Pre v4.14 kernels don't support map names. + */ + memset(attr.map_name, 0, sizeof(attr.map_name)); + return sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr)); + } + return ret; } int bpf_create_map_node(enum bpf_map_type map_type, const char *name, |