From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753366AbbJ0KRL (ORCPT ); Tue, 27 Oct 2015 06:17:11 -0400 Received: from mx2.suse.de ([195.135.220.15]:54783 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751573AbbJ0KRJ (ORCPT ); Tue, 27 Oct 2015 06:17:09 -0400 Message-ID: <1445941026.16404.35.camel@suse.de> Subject: Re: [PATCH 3/3] megaraid_sas: return -ENOMEM when create DMA pool for cmd frames failed From: Johannes Thumshirn To: Weidong Wang , kashyap.desai@avagotech.com, sumit.saxena@avagotech.com, uday.lingala@avagotech.com, JBottomley@odin.com Cc: megaraidlinux.pdl@avagotech.com, linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org Date: Tue, 27 Oct 2015 11:17:06 +0100 In-Reply-To: <1445934375-17784-4-git-send-email-wangweidong1@huawei.com> References: <1445934375-17784-1-git-send-email-wangweidong1@huawei.com> <1445934375-17784-4-git-send-email-wangweidong1@huawei.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.18.0 Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2015-10-27 at 16:26 +0800, Weidong Wang wrote: > when create DMA pool for cmd frames failed, we should return -ENOMEM, > instead of 0. > In some case in: > >     megasas_init_adapter_fusion() > >     -->megasas_alloc_cmds() >        -->megasas_create_frame_pool >           create DMA pool failed, >         --> megasas_free_cmds() [1] > >     -->megasas_alloc_cmds_fusion() >        failed, then goto fail_alloc_cmds. >     -->megasas_free_cmds() [2] > > we will call megasas_free_cmds twice, [1] will kfree cmd_list, > [2] will use cmd_list.it will cause a problem: > > Unable to handle kernel NULL pointer dereference at virtual address > 00000000 > pgd = ffffffc000f70000 > [00000000] *pgd=0000001fbf893003, *pud=0000001fbf893003, > *pmd=0000001fbf894003, *pte=006000006d000707 > Internal error: Oops: 96000005 [#1] SMP >  Modules linked in: >  CPU: 18 PID: 1 Comm: swapper/0 Not tainted >  task: ffffffdfb9290000 ti: ffffffdfb923c000 task.ti: > ffffffdfb923c000 >  PC is at megasas_free_cmds+0x30/0x70 >  LR is at megasas_free_cmds+0x24/0x70 > >  ... > >  Call trace: >  [] megasas_free_cmds+0x30/0x70 >  [] megasas_init_adapter_fusion+0x2f4/0x4d8 >  [] megasas_init_fw+0x2dc/0x760 >  [] megasas_probe_one+0x3c0/0xcd8 >  [] local_pci_probe+0x4c/0xb4 >  [] pci_device_probe+0x11c/0x14c >  [] driver_probe_device+0x1ec/0x430 >  [] __driver_attach+0xa8/0xb0 >  [] bus_for_each_dev+0x74/0xc8 >   [] driver_attach+0x28/0x34 >  [] bus_add_driver+0x16c/0x248 >  [] driver_register+0x6c/0x138 >  [] __pci_register_driver+0x5c/0x6c >  [] megasas_init+0xc0/0x1a8 >  [] do_one_initcall+0xe8/0x1ec >  [] kernel_init_freeable+0x1c8/0x284 >  [] kernel_init+0x1c/0xe4 > > Signed-off-by: Weidong Wang > --- >  drivers/scsi/megaraid/megaraid_sas_base.c | 3 ++- >  1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c > b/drivers/scsi/megaraid/megaraid_sas_base.c > index 2287aa1..8215218 100644 > --- a/drivers/scsi/megaraid/megaraid_sas_base.c > +++ b/drivers/scsi/megaraid/megaraid_sas_base.c > @@ -3746,8 +3746,9 @@ int megasas_alloc_cmds(struct megasas_instance > *instance) >    * Create a frame pool and assign one frame to each cmd >    */ >   if (megasas_create_frame_pool(instance)) { > - dev_dbg(&instance->pdev->dev, "Error creating frame > DMA pool\n"); > + dev_err(&instance->pdev->dev, "Error creating frame > DMA pool\n"); >   megasas_free_cmds(instance); > + return -ENOMEM; >   } >   >   return 0; I think this is needed for stable as well. Other than that, Reviewed-by: Johannes Thumshirn Thanks, Johannes