Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753751AbZIXRBv (ORCPT ); Thu, 24 Sep 2009 13:01:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753726AbZIXRBu (ORCPT ); Thu, 24 Sep 2009 13:01:50 -0400 Received: from e4.ny.us.ibm.com ([32.97.182.144]:32968 "EHLO e4.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753011AbZIXRBt (ORCPT ); Thu, 24 Sep 2009 13:01:49 -0400 Date: Thu, 24 Sep 2009 10:00:47 -0700 From: Sukadev Bhattiprolu To: linux-kernel@vger.kernel.org Cc: Oren Laadan , serue@us.ibm.com, "Eric W. Biederman" , Alexey Dobriyan , Pavel Emelyanov , Andrew Morton , torvalds@linux-foundation.org, mikew@google.com, mingo@elte.hu, hpa@zytor.com, Nathan Lynch , arnd@arndb.de, peterz@infradead.org, Containers , sukadev@us.ibm.com Subject: [RFC][v7][PATCH 2/9]: Have alloc_pidmap() return actual error code Message-ID: <20090924170047.GB16989@us.ibm.com> References: <20090924165548.GA16586@us.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090924165548.GA16586@us.ibm.com> X-Operating-System: Linux 2.0.32 on an i486 User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2806 Lines: 94 Subject: [RFC][v7][PATCH 2/9]: Have alloc_pidmap() return actual error code alloc_pidmap() can fail either because all pid numbers are in use or because memory allocation failed. With support for setting a specific pid number, alloc_pidmap() would also fail if either the given pid number is invalid or in use. Rather than have callers assume -ENOMEM, have alloc_pidmap() return the actual error. Signed-off-by: Sukadev Bhattiprolu Acked-by: Serge Hallyn Reviewed-by: Oren Laadan --- kernel/fork.c | 5 +++-- kernel/pid.c | 14 +++++++++----- 2 files changed, 12 insertions(+), 7 deletions(-) Index: linux-2.6/kernel/fork.c =================================================================== --- linux-2.6.orig/kernel/fork.c 2009-09-09 19:06:21.000000000 -0700 +++ linux-2.6/kernel/fork.c 2009-09-09 19:06:46.000000000 -0700 @@ -1110,10 +1110,11 @@ static struct task_struct *copy_process( goto bad_fork_cleanup_io; if (pid != &init_struct_pid) { - retval = -ENOMEM; pid = alloc_pid(p->nsproxy->pid_ns); - if (!pid) + if (IS_ERR(pid)) { + retval = PTR_ERR(pid); goto bad_fork_cleanup_io; + } if (clone_flags & CLONE_NEWPID) { retval = pid_ns_prepare_proc(p->nsproxy->pid_ns); Index: linux-2.6/kernel/pid.c =================================================================== --- linux-2.6.orig/kernel/pid.c 2009-09-09 19:06:25.000000000 -0700 +++ linux-2.6/kernel/pid.c 2009-09-09 19:06:46.000000000 -0700 @@ -150,7 +150,7 @@ static int alloc_pidmap_page(struct pidm static int alloc_pidmap(struct pid_namespace *pid_ns) { int i, offset, max_scan, pid, last = pid_ns->last_pid; - int rc; + int rc = -EAGAIN; struct pidmap *map; pid = last + 1; @@ -189,12 +189,14 @@ static int alloc_pidmap(struct pid_names } else { map = &pid_ns->pidmap[0]; offset = RESERVED_PIDS; - if (unlikely(last == offset)) + if (unlikely(last == offset)) { + rc = -EAGAIN; break; + } } pid = mk_pid(pid_ns, map, offset); } - return -1; + return rc; } int next_pidmap(struct pid_namespace *pid_ns, int last) @@ -263,8 +265,10 @@ struct pid *alloc_pid(struct pid_namespa struct upid *upid; pid = kmem_cache_alloc(ns->pid_cachep, GFP_KERNEL); - if (!pid) + if (!pid) { + pid = ERR_PTR(-ENOMEM); goto out; + } tmp = ns; for (i = ns->level; i >= 0; i--) { @@ -299,7 +303,7 @@ out_free: free_pidmap(pid->numbers + i); kmem_cache_free(ns->pid_cachep, pid); - pid = NULL; + pid = ERR_PTR(nr); goto out; } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/