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| author |   Roman Gushchin <guro@fb.com> | 2018-08-02 14:27:20 -0700 |
|---|---|---|
| committer |   Daniel Borkmann <daniel@iogearbox.net> | 2018-08-03 00:47:32 +0200 |
| commit | d7bf2c10af053191e931b58704cd862fccb7f9de (patch) | |
| tree | 825c4684143951754d5490aec16495733e0c6a48 /kernel/bpf/cgroup.c | |
| parent | bpf: pass a pointer to a cgroup storage using pcpu variable (diff) | |
| download | linux-dev-d7bf2c10af053191e931b58704cd862fccb7f9de.tar.xz linux-dev-d7bf2c10af053191e931b58704cd862fccb7f9de.zip | |
bpf: allocate cgroup storage entries on attaching bpf programs
If a bpf program is using cgroup local storage, allocate
a bpf_cgroup_storage structure automatically on attaching the program
to a cgroup and save the pointer into the corresponding bpf_prog_list
entry.
Analogically, release the cgroup local storage on detaching
of the bpf program.
Signed-off-by: Roman Gushchin <guro@fb.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Diffstat (limited to 'kernel/bpf/cgroup.c')
| -rw-r--r-- | kernel/bpf/cgroup.c | 35 |
1 files changed, 31 insertions, 4 deletions
diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c index badabb0b435c..935274c86bfe 100644 --- a/kernel/bpf/cgroup.c +++ b/kernel/bpf/cgroup.c @@ -34,6 +34,8 @@ void cgroup_bpf_put(struct cgroup *cgrp) list_for_each_entry_safe(pl, tmp, progs, node) { list_del(&pl->node); bpf_prog_put(pl->prog); + bpf_cgroup_storage_unlink(pl->storage); + bpf_cgroup_storage_free(pl->storage); kfree(pl); static_branch_dec(&cgroup_bpf_enabled_key); } @@ -188,6 +190,7 @@ int __cgroup_bpf_attach(struct cgroup *cgrp, struct bpf_prog *prog, { struct list_head *progs = &cgrp->bpf.progs[type]; struct bpf_prog *old_prog = NULL; + struct bpf_cgroup_storage *storage, *old_storage = NULL; struct cgroup_subsys_state *css; struct bpf_prog_list *pl; bool pl_was_allocated; @@ -210,31 +213,47 @@ int __cgroup_bpf_attach(struct cgroup *cgrp, struct bpf_prog *prog, if (prog_list_length(progs) >= BPF_CGROUP_MAX_PROGS) return -E2BIG; + storage = bpf_cgroup_storage_alloc(prog); + if (IS_ERR(storage)) + return -ENOMEM; + if (flags & BPF_F_ALLOW_MULTI) { - list_for_each_entry(pl, progs, node) - if (pl->prog == prog) + list_for_each_entry(pl, progs, node) { + if (pl->prog == prog) { /* disallow attaching the same prog twice */ + bpf_cgroup_storage_free(storage); return -EINVAL; + } + } pl = kmalloc(sizeof(*pl), GFP_KERNEL); - if (!pl) + if (!pl) { + bpf_cgroup_storage_free(storage); return -ENOMEM; + } + pl_was_allocated = true; pl->prog = prog; + pl->storage = storage; list_add_tail(&pl->node, progs); } else { if (list_empty(progs)) { pl = kmalloc(sizeof(*pl), GFP_KERNEL); - if (!pl) + if (!pl) { + bpf_cgroup_storage_free(storage); return -ENOMEM; + } pl_was_allocated = true; list_add_tail(&pl->node, progs); } else { pl = list_first_entry(progs, typeof(*pl), node); old_prog = pl->prog; + old_storage = pl->storage; + bpf_cgroup_storage_unlink(old_storage); pl_was_allocated = false; } pl->prog = prog; + pl->storage = storage; } cgrp->bpf.flags[type] = flags; @@ -257,10 +276,13 @@ int __cgroup_bpf_attach(struct cgroup *cgrp, struct bpf_prog *prog, } static_branch_inc(&cgroup_bpf_enabled_key); + if (old_storage) + bpf_cgroup_storage_free(old_storage); if (old_prog) { bpf_prog_put(old_prog); static_branch_dec(&cgroup_bpf_enabled_key); } + bpf_cgroup_storage_link(storage, cgrp, type); return 0; cleanup: @@ -276,6 +298,9 @@ cleanup: /* and cleanup the prog list */ pl->prog = old_prog; + bpf_cgroup_storage_free(pl->storage); + pl->storage = old_storage; + bpf_cgroup_storage_link(old_storage, cgrp, type); if (pl_was_allocated) { list_del(&pl->node); kfree(pl); @@ -356,6 +381,8 @@ int __cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog, /* now can actually delete it from this cgroup list */ list_del(&pl->node); + bpf_cgroup_storage_unlink(pl->storage); + bpf_cgroup_storage_free(pl->storage); kfree(pl); if (list_empty(progs)) /* last program was detached, reset flags to zero */ |