diff options
| author | Andrii Nakryiko <andriin@fb.com> | 2020-03-29 19:59:59 -0700 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2020-03-30 17:36:33 -0700 |
| commit | 0c991ebc8c69d29b7fc44db17075c5aa5253e2ab (patch) | |
| tree | e61172384e68887343d57f1e40d47c2e5ecc98cc /include/linux/bpf-cgroup.h | |
| parent | af6eea57437a830293eab56246b6025cc7d46ee7 (diff) | |
bpf: Implement bpf_prog replacement for an active bpf_cgroup_link
Add new operation (LINK_UPDATE), which allows to replace active bpf_prog from
under given bpf_link. Currently this is only supported for bpf_cgroup_link,
but will be extended to other kinds of bpf_links in follow-up patches.
For bpf_cgroup_link, implemented functionality matches existing semantics for
direct bpf_prog attachment (including BPF_F_REPLACE flag). User can either
unconditionally set new bpf_prog regardless of which bpf_prog is currently
active under given bpf_link, or, optionally, can specify expected active
bpf_prog. If active bpf_prog doesn't match expected one, no changes are
performed, old bpf_link stays intact and attached, operation returns
a failure.
cgroup_bpf_replace() operation is resolving race between auto-detachment and
bpf_prog update in the same fashion as it's done for bpf_link detachment,
except in this case update has no way of succeeding because of target cgroup
marked as dying. So in this case error is returned.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200330030001.2312810-3-andriin@fb.com
Diffstat (limited to 'include/linux/bpf-cgroup.h')
| -rw-r--r-- | include/linux/bpf-cgroup.h | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/include/linux/bpf-cgroup.h b/include/linux/bpf-cgroup.h index d2d969669564..c11b413d5b1a 100644 --- a/include/linux/bpf-cgroup.h +++ b/include/linux/bpf-cgroup.h @@ -100,6 +100,8 @@ int __cgroup_bpf_attach(struct cgroup *cgrp, int __cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog, struct bpf_cgroup_link *link, enum bpf_attach_type type); +int __cgroup_bpf_replace(struct cgroup *cgrp, struct bpf_cgroup_link *link, + struct bpf_prog *new_prog); int __cgroup_bpf_query(struct cgroup *cgrp, const union bpf_attr *attr, union bpf_attr __user *uattr); @@ -110,6 +112,8 @@ int cgroup_bpf_attach(struct cgroup *cgrp, u32 flags); int cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog, enum bpf_attach_type type); +int cgroup_bpf_replace(struct bpf_link *link, struct bpf_prog *old_prog, + struct bpf_prog *new_prog); int cgroup_bpf_query(struct cgroup *cgrp, const union bpf_attr *attr, union bpf_attr __user *uattr); @@ -350,6 +354,7 @@ int cgroup_bpf_prog_query(const union bpf_attr *attr, #else struct bpf_prog; +struct bpf_link; struct cgroup_bpf {}; static inline int cgroup_bpf_inherit(struct cgroup *cgrp) { return 0; } static inline void cgroup_bpf_offline(struct cgroup *cgrp) {} @@ -373,6 +378,13 @@ static inline int cgroup_bpf_link_attach(const union bpf_attr *attr, return -EINVAL; } +static inline int cgroup_bpf_replace(struct bpf_link *link, + struct bpf_prog *old_prog, + struct bpf_prog *new_prog) +{ + return -EINVAL; +} + static inline int cgroup_bpf_prog_query(const union bpf_attr *attr, union bpf_attr __user *uattr) { |