From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:47574 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752199AbeCPOq5 (ORCPT ); Fri, 16 Mar 2018 10:46:57 -0400 Subject: Patch "locking/locktorture: Fix num reader/writer corner cases" has been added to the 4.14-stable tree To: dave@stgolabs.net, alexander.levin@microsoft.com, dbueso@suse.de, gregkh@linuxfoundation.org, jeremy.linton@arm.com, paulmck@linux.vnet.ibm.com Cc: , From: Date: Fri, 16 Mar 2018 15:45:58 +0100 Message-ID: <1521211558232125@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled locking/locktorture: Fix num reader/writer corner cases to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: locking-locktorture-fix-num-reader-writer-corner-cases.patch and it can be found in the queue-4.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From foo@baz Fri Mar 16 15:43:17 CET 2018 From: Davidlohr Bueso Date: Mon, 15 May 2017 02:07:23 -0700 Subject: locking/locktorture: Fix num reader/writer corner cases From: Davidlohr Bueso [ Upstream commit 2ce77d16db4240dd2e422fc0a5c26d3e2ec03446 ] Things can explode for locktorture if the user does combinations of nwriters_stress=0 nreaders_stress=0. Fix this by not assuming we always want to torture writer threads. Reported-by: Jeremy Linton Signed-off-by: Davidlohr Bueso Signed-off-by: Paul E. McKenney Reviewed-by: Jeremy Linton Tested-by: Jeremy Linton Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- kernel/locking/locktorture.c | 76 ++++++++++++++++++++++++------------------- 1 file changed, 44 insertions(+), 32 deletions(-) --- a/kernel/locking/locktorture.c +++ b/kernel/locking/locktorture.c @@ -715,8 +715,7 @@ static void __torture_print_stats(char * { bool fail = 0; int i, n_stress; - long max = 0; - long min = statp[0].n_lock_acquired; + long max = 0, min = statp ? statp[0].n_lock_acquired : 0; long long sum = 0; n_stress = write ? cxt.nrealwriters_stress : cxt.nrealreaders_stress; @@ -823,7 +822,7 @@ static void lock_torture_cleanup(void) * such, only perform the underlying torture-specific cleanups, * and avoid anything related to locktorture. */ - if (!cxt.lwsa) + if (!cxt.lwsa && !cxt.lrsa) goto end; if (writer_tasks) { @@ -898,6 +897,13 @@ static int __init lock_torture_init(void firsterr = -EINVAL; goto unwind; } + + if (nwriters_stress == 0 && nreaders_stress == 0) { + pr_alert("lock-torture: must run at least one locking thread\n"); + firsterr = -EINVAL; + goto unwind; + } + if (cxt.cur_ops->init) cxt.cur_ops->init(); @@ -921,17 +927,19 @@ static int __init lock_torture_init(void #endif /* Initialize the statistics so that each run gets its own numbers. */ + if (nwriters_stress) { + lock_is_write_held = 0; + cxt.lwsa = kmalloc(sizeof(*cxt.lwsa) * cxt.nrealwriters_stress, GFP_KERNEL); + if (cxt.lwsa == NULL) { + VERBOSE_TOROUT_STRING("cxt.lwsa: Out of memory"); + firsterr = -ENOMEM; + goto unwind; + } - lock_is_write_held = 0; - cxt.lwsa = kmalloc(sizeof(*cxt.lwsa) * cxt.nrealwriters_stress, GFP_KERNEL); - if (cxt.lwsa == NULL) { - VERBOSE_TOROUT_STRING("cxt.lwsa: Out of memory"); - firsterr = -ENOMEM; - goto unwind; - } - for (i = 0; i < cxt.nrealwriters_stress; i++) { - cxt.lwsa[i].n_lock_fail = 0; - cxt.lwsa[i].n_lock_acquired = 0; + for (i = 0; i < cxt.nrealwriters_stress; i++) { + cxt.lwsa[i].n_lock_fail = 0; + cxt.lwsa[i].n_lock_acquired = 0; + } } if (cxt.cur_ops->readlock) { @@ -948,19 +956,21 @@ static int __init lock_torture_init(void cxt.nrealreaders_stress = cxt.nrealwriters_stress; } - lock_is_read_held = 0; - cxt.lrsa = kmalloc(sizeof(*cxt.lrsa) * cxt.nrealreaders_stress, GFP_KERNEL); - if (cxt.lrsa == NULL) { - VERBOSE_TOROUT_STRING("cxt.lrsa: Out of memory"); - firsterr = -ENOMEM; - kfree(cxt.lwsa); - cxt.lwsa = NULL; - goto unwind; - } - - for (i = 0; i < cxt.nrealreaders_stress; i++) { - cxt.lrsa[i].n_lock_fail = 0; - cxt.lrsa[i].n_lock_acquired = 0; + if (nreaders_stress) { + lock_is_read_held = 0; + cxt.lrsa = kmalloc(sizeof(*cxt.lrsa) * cxt.nrealreaders_stress, GFP_KERNEL); + if (cxt.lrsa == NULL) { + VERBOSE_TOROUT_STRING("cxt.lrsa: Out of memory"); + firsterr = -ENOMEM; + kfree(cxt.lwsa); + cxt.lwsa = NULL; + goto unwind; + } + + for (i = 0; i < cxt.nrealreaders_stress; i++) { + cxt.lrsa[i].n_lock_fail = 0; + cxt.lrsa[i].n_lock_acquired = 0; + } } } @@ -990,12 +1000,14 @@ static int __init lock_torture_init(void goto unwind; } - writer_tasks = kzalloc(cxt.nrealwriters_stress * sizeof(writer_tasks[0]), - GFP_KERNEL); - if (writer_tasks == NULL) { - VERBOSE_TOROUT_ERRSTRING("writer_tasks: Out of memory"); - firsterr = -ENOMEM; - goto unwind; + if (nwriters_stress) { + writer_tasks = kzalloc(cxt.nrealwriters_stress * sizeof(writer_tasks[0]), + GFP_KERNEL); + if (writer_tasks == NULL) { + VERBOSE_TOROUT_ERRSTRING("writer_tasks: Out of memory"); + firsterr = -ENOMEM; + goto unwind; + } } if (cxt.cur_ops->readlock) { Patches currently in stable-queue which might be from dave@stgolabs.net are queue-4.14/locking-locktorture-fix-num-reader-writer-corner-cases.patch