A checkpoint taken on a kernel without CONFIG_{IPC,UTS}_NS will leave
the corresponding objref field in the nsproxy header untouched, and
therefore it will remain zero.This patch ensures that do_restore_ns() gracefully handles this by borrowing from the nsproxy of the root-task. Signed-off-by: Oren Laadan <[email protected]> --- kernel/nsproxy.c | 71 +++++++++++++++++++++++++++++------------------------ 1 files changed, 39 insertions(+), 32 deletions(-) diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c index b0e71f2..cfef7bc 100644 --- a/kernel/nsproxy.c +++ b/kernel/nsproxy.c @@ -312,54 +312,61 @@ static struct nsproxy *do_restore_ns(struct ckpt_ctx *ctx) struct nsproxy *nsproxy = NULL; struct uts_namespace *uts_ns; struct ipc_namespace *ipc_ns; + struct mnt_namespace *mnt_ns; + struct net *net_ns; int ret; h = ckpt_read_obj_type(ctx, sizeof(*h), CKPT_HDR_NS); if (IS_ERR(h)) return (struct nsproxy *) h; - ret = -EINVAL; - if (h->uts_objref <= 0 || - h->ipc_objref <= 0) - goto out; - - uts_ns = ckpt_obj_fetch(ctx, h->uts_objref, CKPT_OBJ_UTS_NS); + if (h->uts_objref == 0) + uts_ns = ctx->root_nsproxy->uts_ns; + else + uts_ns = ckpt_obj_fetch(ctx, h->uts_objref, CKPT_OBJ_UTS_NS); if (IS_ERR(uts_ns)) { ret = PTR_ERR(uts_ns); goto out; } - ipc_ns = ckpt_obj_fetch(ctx, h->ipc_objref, CKPT_OBJ_IPC_NS); + + if (h->ipc_objref == 0) + ipc_ns = ctx->root_nsproxy->ipc_ns; + else + ipc_ns = ckpt_obj_fetch(ctx, h->ipc_objref, CKPT_OBJ_IPC_NS); if (IS_ERR(ipc_ns)) { ret = PTR_ERR(ipc_ns); goto out; } -#if defined(COFNIG_UTS_NS) || defined(CONFIG_IPC_NS) - ret = -ENOMEM; - nsproxy = create_nsproxy(); - if (!nsproxy) - goto out; + mnt_ns = ctx->root_nsproxy->mnt_ns; + net_ns = ctx->root_nsproxy->net_ns; + + if (uts_ns == current->nsproxy->uts_ns && + ipc_ns == current->nsproxy->ipc_ns && + mnt_ns == current->nsproxy->mnt_ns && + net_ns == current->nsproxy->net_ns) { + /* all xxx-ns are identical: reuse nsproxy */ + nsproxy = current->nsproxy; + get_nsproxy(nsproxy); + } else { + ret = -ENOMEM; + nsproxy = create_nsproxy(); + if (!nsproxy) + goto out; + + get_uts_ns(uts_ns); + nsproxy->uts_ns = uts_ns; + get_ipc_ns(ipc_ns); + nsproxy->ipc_ns = ipc_ns; + get_mnt_ns(mnt_ns); + nsproxy->mnt_ns = mnt_ns; + get_net(net_ns); + nsproxy->net_ns = net_ns; + + get_pid_ns(current->nsproxy->pid_ns); + nsproxy->pid_ns = current->nsproxy->pid_ns; + } - get_uts_ns(uts_ns); - nsproxy->uts_ns = uts_ns; - get_ipc_ns(ipc_ns); - nsproxy->ipc_ns = ipc_ns; - - get_pid_ns(current->nsproxy->pid_ns); - nsproxy->pid_ns = current->nsproxy->pid_ns; - get_mnt_ns(current->nsproxy->mnt_ns); - nsproxy->mnt_ns = current->nsproxy->mnt_ns; - get_net(current->nsproxy->net_ns); - nsproxy->net_ns = current->nsproxy->net_ns; -#else - nsproxy = current->nsproxy; - get_nsproxy(nsproxy); - - BUG_ON(nsproxy->uts_ns != uts_ns); - BUG_ON(nsproxy->ipc_ns != ipc_ns); -#endif - - /* TODO: add more namespaces here */ ret = 0; out: if (ret < 0) -- 1.6.3.3 _______________________________________________ Containers mailing list [email protected] https://lists.linux-foundation.org/mailman/listinfo/containers _______________________________________________ Devel mailing list [email protected] https://openvz.org/mailman/listinfo/devel
