[RFC v4 14/18] bpf/cgroup: Make cgroup_bpf_update() return an error code
From: Mickaël Salaün <mic@digikod.net>
Date: 2016-10-26 07:04:44
Also in:
cgroups, linux-api, lkml
Subsystem:
bpf [core], bpf [general] (safe dynamic programs and tools), bpf [storage & cgroups], the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Martin KaFai Lau, Linus Torvalds
This will be useful to support Landlock for the next commits. Signed-off-by: Mickaël Salaün <mic@digikod.net> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Daniel Mack <daniel@zonque.org> Cc: David S. Miller <davem@davemloft.net> Cc: Tejun Heo <tj@kernel.org> --- include/linux/bpf-cgroup.h | 4 ++-- kernel/bpf/cgroup.c | 3 ++- kernel/bpf/syscall.c | 10 ++++++---- kernel/cgroup.c | 6 ++++-- 4 files changed, 14 insertions(+), 9 deletions(-)
diff --git a/include/linux/bpf-cgroup.h b/include/linux/bpf-cgroup.h
index 2f608e5d94e9..aab1aa91c064 100644
--- a/include/linux/bpf-cgroup.h
+++ b/include/linux/bpf-cgroup.h@@ -31,13 +31,13 @@ struct cgroup_bpf { void cgroup_bpf_put(struct cgroup *cgrp); void cgroup_bpf_inherit(struct cgroup *cgrp, struct cgroup *parent); -void __cgroup_bpf_update(struct cgroup *cgrp, +int __cgroup_bpf_update(struct cgroup *cgrp, struct cgroup *parent, struct bpf_prog *prog, enum bpf_attach_type type); /* Wrapper for __cgroup_bpf_update() protected by cgroup_mutex */ -void cgroup_bpf_update(struct cgroup *cgrp, +int cgroup_bpf_update(struct cgroup *cgrp, struct bpf_prog *prog, enum bpf_attach_type type);
diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c
index 75482cd92d56..269b410d890c 100644
--- a/kernel/bpf/cgroup.c
+++ b/kernel/bpf/cgroup.c@@ -83,7 +83,7 @@ void cgroup_bpf_inherit(struct cgroup *cgrp, struct cgroup *parent) * * Must be called with cgroup_mutex held. */ -void __cgroup_bpf_update(struct cgroup *cgrp, +int __cgroup_bpf_update(struct cgroup *cgrp, struct cgroup *parent, struct bpf_prog *prog, enum bpf_attach_type type)
@@ -116,6 +116,7 @@ void __cgroup_bpf_update(struct cgroup *cgrp, bpf_prog_put(old_prog); static_branch_dec(&cgroup_bpf_enabled_key); } + return 0; } /**
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index ac4cbb98596d..e62123aeb202 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c@@ -831,6 +831,7 @@ static int bpf_prog_attach(const union bpf_attr *attr) { struct bpf_prog *prog; struct cgroup *cgrp; + int result; if (!capable(CAP_NET_ADMIN)) return -EPERM;
@@ -858,10 +859,10 @@ static int bpf_prog_attach(const union bpf_attr *attr) return PTR_ERR(cgrp); } - cgroup_bpf_update(cgrp, prog, attr->attach_type); + result = cgroup_bpf_update(cgrp, prog, attr->attach_type); cgroup_put(cgrp); - return 0; + return result; } #define BPF_PROG_DETACH_LAST_FIELD attach_type
@@ -869,6 +870,7 @@ static int bpf_prog_attach(const union bpf_attr *attr) static int bpf_prog_detach(const union bpf_attr *attr) { struct cgroup *cgrp; + int result = 0; if (!capable(CAP_NET_ADMIN)) return -EPERM;
@@ -883,7 +885,7 @@ static int bpf_prog_detach(const union bpf_attr *attr) if (IS_ERR(cgrp)) return PTR_ERR(cgrp); - cgroup_bpf_update(cgrp, NULL, attr->attach_type); + result = cgroup_bpf_update(cgrp, NULL, attr->attach_type); cgroup_put(cgrp); break;
@@ -891,7 +893,7 @@ static int bpf_prog_detach(const union bpf_attr *attr) return -EINVAL; } - return 0; + return result; } #endif /* CONFIG_CGROUP_BPF */
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 2ee9ec3051b2..f77a974eb960 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c@@ -6501,15 +6501,17 @@ static __init int cgroup_namespaces_init(void) subsys_initcall(cgroup_namespaces_init); #ifdef CONFIG_CGROUP_BPF -void cgroup_bpf_update(struct cgroup *cgrp, +int cgroup_bpf_update(struct cgroup *cgrp, struct bpf_prog *prog, enum bpf_attach_type type) { struct cgroup *parent = cgroup_parent(cgrp); + int result; mutex_lock(&cgroup_mutex); - __cgroup_bpf_update(cgrp, parent, prog, type); + result = __cgroup_bpf_update(cgrp, parent, prog, type); mutex_unlock(&cgroup_mutex); + return result; } #endif /* CONFIG_CGROUP_BPF */
--
2.9.3