From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:42020 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755725AbeCWKJP (ORCPT ); Fri, 23 Mar 2018 06:09:15 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Sameer Wadgaonkar , David Kershner , Sasha Levin Subject: [PATCH 4.9 088/177] staging: unisys: visorhba: fix s-Par to boot with option CONFIG_VMAP_STACK set to y Date: Fri, 23 Mar 2018 10:53:36 +0100 Message-Id: <20180323094209.170789235@linuxfoundation.org> In-Reply-To: <20180323094205.090519271@linuxfoundation.org> References: <20180323094205.090519271@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sameer Wadgaonkar [ Upstream commit 3c2bf0bd08123f3497bd3e84bd9088c937b0cb40 ] The root issue is that we are not allowed to have items on the stack being passed to "DMA" like operations. In this case we have a vmcall and an inline completion of scsi command. This patch fixes the issue by moving the variables on stack in do_scsi_nolinuxstat() to heap memory. Signed-off-by: Sameer Wadgaonkar Signed-off-by: David Kershner Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/staging/unisys/visorhba/visorhba_main.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) --- a/drivers/staging/unisys/visorhba/visorhba_main.c +++ b/drivers/staging/unisys/visorhba/visorhba_main.c @@ -842,7 +842,7 @@ static void do_scsi_nolinuxstat(struct uiscmdrsp *cmdrsp, struct scsi_cmnd *scsicmd) { struct scsi_device *scsidev; - unsigned char buf[36]; + unsigned char *buf; struct scatterlist *sg; unsigned int i; char *this_page; @@ -857,6 +857,10 @@ do_scsi_nolinuxstat(struct uiscmdrsp *cm if (cmdrsp->scsi.no_disk_result == 0) return; + buf = kzalloc(sizeof(char) * 36, GFP_KERNEL); + if (!buf) + return; + /* Linux scsi code wants a device at Lun 0 * to issue report luns, but we don't want * a disk there so we'll present a processor @@ -868,6 +872,7 @@ do_scsi_nolinuxstat(struct uiscmdrsp *cm if (scsi_sg_count(scsicmd) == 0) { memcpy(scsi_sglist(scsicmd), buf, cmdrsp->scsi.bufflen); + kfree(buf); return; } @@ -879,6 +884,7 @@ do_scsi_nolinuxstat(struct uiscmdrsp *cm memcpy(this_page, buf + bufind, sg[i].length); kunmap_atomic(this_page_orig); } + kfree(buf); } else { devdata = (struct visorhba_devdata *)scsidev->host->hostdata; for_each_vdisk_match(vdisk, devdata, scsidev) {