From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754991AbbGQXps (ORCPT ); Fri, 17 Jul 2015 19:45:48 -0400 Received: from e33.co.us.ibm.com ([32.97.110.151]:37920 "EHLO e33.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754860AbbGQXpq (ORCPT ); Fri, 17 Jul 2015 19:45:46 -0400 X-Helo: d03dlp02.boulder.ibm.com X-MailFrom: paulmck@linux.vnet.ibm.com X-RcptTo: linux-kernel@vger.kernel.org From: "Paul E. McKenney" To: linux-kernel@vger.kernel.org Cc: mingo@kernel.org, jiangshanlai@gmail.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@efficios.com, josh@joshtriplett.org, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com, dvhart@linux.intel.com, fweisbec@gmail.com, oleg@redhat.com, bobby.prani@gmail.com, "Paul E. McKenney" Subject: [PATCH tip/core/rcu 2/6] rcutorture: Check nfakewriters parameter Date: Fri, 17 Jul 2015 16:45:33 -0700 Message-Id: <1437176737-26668-2-git-send-email-paulmck@linux.vnet.ibm.com> X-Mailer: git-send-email 1.8.1.5 In-Reply-To: <1437176737-26668-1-git-send-email-paulmck@linux.vnet.ibm.com> References: <20150717234518.GA26072@linux.vnet.ibm.com> <1437176737-26668-1-git-send-email-paulmck@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15071723-0009-0000-0000-00000C91A8B5 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Paul E. McKenney" Currently, a negative value for rcutorture.nfakewriters= can cause rcutorture to pass a negative size to the memory allocator, which is not really a particularly good thing to do. This commit therefore adds bounds checking to this parameter, so that values that are less than or equal to zero disable fake writing. Signed-off-by: Paul E. McKenney --- kernel/rcu/rcutorture.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index 7e29a3266139..2cbe569ac5dd 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -1786,12 +1786,15 @@ rcu_torture_init(void) writer_task); if (firsterr) goto unwind; - fakewriter_tasks = kzalloc(nfakewriters * sizeof(fakewriter_tasks[0]), - GFP_KERNEL); - if (fakewriter_tasks == NULL) { - VERBOSE_TOROUT_ERRSTRING("out of memory"); - firsterr = -ENOMEM; - goto unwind; + if (nfakewriters > 0) { + fakewriter_tasks = kzalloc(nfakewriters * + sizeof(fakewriter_tasks[0]), + GFP_KERNEL); + if (fakewriter_tasks == NULL) { + VERBOSE_TOROUT_ERRSTRING("out of memory"); + firsterr = -ENOMEM; + goto unwind; + } } for (i = 0; i < nfakewriters; i++) { firsterr = torture_create_kthread(rcu_torture_fakewriter, -- 1.8.1.5