diff options
| -rw-r--r-- | include/uapi/linux/bpf.h | 7 | ||||
| -rw-r--r-- | kernel/bpf/cgroup.c | 28 | ||||
| -rw-r--r-- | tools/include/uapi/linux/bpf.h | 7 |
3 files changed, 28 insertions, 14 deletions
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 59a217ca2dfd..4eff7fc7ae58 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -1233,7 +1233,7 @@ enum { /* Query effective (directly attached + inherited from ancestor cgroups) * programs that will be executed for events within a cgroup. - * attach_flags with this flag are returned only for directly attached programs. + * attach_flags with this flag are always returned 0. */ #define BPF_F_QUERY_EFFECTIVE (1U << 0) @@ -1432,7 +1432,10 @@ union bpf_attr { __u32 attach_flags; __aligned_u64 prog_ids; __u32 prog_cnt; - __aligned_u64 prog_attach_flags; /* output: per-program attach_flags */ + /* output: per-program attach_flags. + * not allowed to be set during effective query. + */ + __aligned_u64 prog_attach_flags; } query; struct { /* anonymous struct used by BPF_RAW_TRACEPOINT_OPEN command */ diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c index 4a400cd63731..22888aaa68b6 100644 --- a/kernel/bpf/cgroup.c +++ b/kernel/bpf/cgroup.c @@ -1020,6 +1020,7 @@ static int __cgroup_bpf_query(struct cgroup *cgrp, const union bpf_attr *attr, union bpf_attr __user *uattr) { __u32 __user *prog_attach_flags = u64_to_user_ptr(attr->query.prog_attach_flags); + bool effective_query = attr->query.query_flags & BPF_F_QUERY_EFFECTIVE; __u32 __user *prog_ids = u64_to_user_ptr(attr->query.prog_ids); enum bpf_attach_type type = attr->query.attach_type; enum cgroup_bpf_attach_type from_atype, to_atype; @@ -1029,8 +1030,12 @@ static int __cgroup_bpf_query(struct cgroup *cgrp, const union bpf_attr *attr, int total_cnt = 0; u32 flags; + if (effective_query && prog_attach_flags) + return -EINVAL; + if (type == BPF_LSM_CGROUP) { - if (attr->query.prog_cnt && prog_ids && !prog_attach_flags) + if (!effective_query && attr->query.prog_cnt && + prog_ids && !prog_attach_flags) return -EINVAL; from_atype = CGROUP_LSM_START; @@ -1045,7 +1050,7 @@ static int __cgroup_bpf_query(struct cgroup *cgrp, const union bpf_attr *attr, } for (atype = from_atype; atype <= to_atype; atype++) { - if (attr->query.query_flags & BPF_F_QUERY_EFFECTIVE) { + if (effective_query) { effective = rcu_dereference_protected(cgrp->bpf.effective[atype], lockdep_is_held(&cgroup_mutex)); total_cnt += bpf_prog_array_length(effective); @@ -1054,6 +1059,8 @@ static int __cgroup_bpf_query(struct cgroup *cgrp, const union bpf_attr *attr, } } + /* always output uattr->query.attach_flags as 0 during effective query */ + flags = effective_query ? 0 : flags; if (copy_to_user(&uattr->query.attach_flags, &flags, sizeof(flags))) return -EFAULT; if (copy_to_user(&uattr->query.prog_cnt, &total_cnt, sizeof(total_cnt))) @@ -1068,7 +1075,7 @@ static int __cgroup_bpf_query(struct cgroup *cgrp, const union bpf_attr *attr, } for (atype = from_atype; atype <= to_atype && total_cnt; atype++) { - if (attr->query.query_flags & BPF_F_QUERY_EFFECTIVE) { + if (effective_query) { effective = rcu_dereference_protected(cgrp->bpf.effective[atype], lockdep_is_held(&cgroup_mutex)); cnt = min_t(int, bpf_prog_array_length(effective), total_cnt); @@ -1090,15 +1097,16 @@ static int __cgroup_bpf_query(struct cgroup *cgrp, const union bpf_attr *attr, if (++i == cnt) break; } - } - if (prog_attach_flags) { - flags = cgrp->bpf.flags[atype]; + if (prog_attach_flags) { + flags = cgrp->bpf.flags[atype]; - for (i = 0; i < cnt; i++) - if (copy_to_user(prog_attach_flags + i, &flags, sizeof(flags))) - return -EFAULT; - prog_attach_flags += cnt; + for (i = 0; i < cnt; i++) + if (copy_to_user(prog_attach_flags + i, + &flags, sizeof(flags))) + return -EFAULT; + prog_attach_flags += cnt; + } } prog_ids += cnt; diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 59a217ca2dfd..4eff7fc7ae58 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -1233,7 +1233,7 @@ enum { /* Query effective (directly attached + inherited from ancestor cgroups) * programs that will be executed for events within a cgroup. - * attach_flags with this flag are returned only for directly attached programs. + * attach_flags with this flag are always returned 0. */ #define BPF_F_QUERY_EFFECTIVE (1U << 0) @@ -1432,7 +1432,10 @@ union bpf_attr { __u32 attach_flags; __aligned_u64 prog_ids; __u32 prog_cnt; - __aligned_u64 prog_attach_flags; /* output: per-program attach_flags */ + /* output: per-program attach_flags. + * not allowed to be set during effective query. + */ + __aligned_u64 prog_attach_flags; } query; struct { /* anonymous struct used by BPF_RAW_TRACEPOINT_OPEN command */ |