From: Roman Gushchin <guro@fb.com>
To: <netdev@vger.kernel.org>
Cc: <linux-kernel@vger.kernel.org>, <kernel-team@fb.com>,
Roman Gushchin <guro@fb.com>, Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>
Subject: [PATCH v6 bpf-next 04/14] bpf: allocate cgroup storage entries on attaching bpf programs
Date: Wed, 1 Aug 2018 15:37:30 -0700 [thread overview]
Message-ID: <20180801223740.11252-5-guro@fb.com> (raw)
In-Reply-To: <20180801223740.11252-1-guro@fb.com>
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>
---
include/linux/bpf-cgroup.h | 1 +
kernel/bpf/cgroup.c | 35 +++++++++++++++++++++++++++++++----
2 files changed, 32 insertions(+), 4 deletions(-)
diff --git a/include/linux/bpf-cgroup.h b/include/linux/bpf-cgroup.h
index 9a144ddbbc8f..f91b0f8ff3a9 100644
--- a/include/linux/bpf-cgroup.h
+++ b/include/linux/bpf-cgroup.h
@@ -43,6 +43,7 @@ struct bpf_cgroup_storage {
struct bpf_prog_list {
struct list_head node;
struct bpf_prog *prog;
+ struct bpf_cgroup_storage *storage;
};
struct bpf_prog_array;
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 @@ int __cgroup_bpf_attach(struct cgroup *cgrp, struct bpf_prog *prog,
/* 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 */
--
2.14.4
next prev parent reply other threads:[~2018-08-01 22:37 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-01 22:37 [PATCH v6 bpf-next 00/14] bpf: cgroup local storage Roman Gushchin
2018-08-01 22:37 ` [PATCH v6 bpf-next 01/14] bpf: add ability to charge bpf maps memory dynamically Roman Gushchin
2018-08-01 22:37 ` [PATCH v6 bpf-next 02/14] bpf: introduce cgroup storage maps Roman Gushchin
2018-08-01 22:37 ` [PATCH v6 bpf-next 03/14] bpf: pass a pointer to a cgroup storage using pcpu variable Roman Gushchin
2018-08-01 22:37 ` Roman Gushchin [this message]
2018-08-01 22:37 ` [PATCH v6 bpf-next 05/14] bpf: extend bpf_prog_array to store pointers to the cgroup storage Roman Gushchin
2018-08-01 22:37 ` [PATCH v6 bpf-next 06/14] bpf/verifier: introduce BPF_PTR_TO_MAP_VALUE Roman Gushchin
2018-08-01 22:37 ` [PATCH v6 bpf-next 07/14] bpf: don't allow create maps of cgroup local storages Roman Gushchin
2018-08-01 22:37 ` [PATCH v6 bpf-next 08/14] bpf: introduce the bpf_get_local_storage() helper function Roman Gushchin
2018-08-01 22:37 ` [PATCH v6 bpf-next 09/14] bpf: sync bpf.h to tools/ Roman Gushchin
2018-08-01 22:37 ` [PATCH v6 bpf-next 10/14] bpftool: add support for CGROUP_STORAGE maps Roman Gushchin
2018-08-01 22:37 ` [PATCH v6 bpf-next 11/14] bpf/test_run: support cgroup local storage Roman Gushchin
2018-08-01 22:37 ` [PATCH v6 bpf-next 12/14] selftests/bpf: add verifier cgroup storage tests Roman Gushchin
2018-08-01 22:37 ` [PATCH v6 bpf-next 13/14] selftests/bpf: add a cgroup storage test Roman Gushchin
2018-08-01 22:37 ` [PATCH v6 bpf-next 14/14] samples/bpf: extend test_cgrp2_attach2 test to use cgroup storage Roman Gushchin
2018-08-02 8:53 ` [PATCH v6 bpf-next 00/14] bpf: cgroup local storage Daniel Borkmann
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