This is a note to let you know that I've just added the patch titled
staging: unisys: visorhba: fix s-Par to boot with option CONFIG_VMAP_STACK set to y
to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: staging-unisys-visorhba-fix-s-par-to-boot-with-option-config_vmap_stack-set-to-y.patch and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From foo@baz Thu Mar 22 14:57:32 CET 2018
From: Sameer Wadgaonkar sameer.wadgaonkar@unisys.com Date: Tue, 18 Apr 2017 16:55:25 -0400 Subject: staging: unisys: visorhba: fix s-Par to boot with option CONFIG_VMAP_STACK set to y
From: Sameer Wadgaonkar sameer.wadgaonkar@unisys.com
[ 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 sameer.wadgaonkar@unisys.com Signed-off-by: David Kershner david.kershner@unisys.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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 @@ -792,7 +792,7 @@ 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; @@ -807,6 +807,10 @@ 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 @@ -820,6 +824,7 @@ do_scsi_nolinuxstat(struct uiscmdrsp *cm if (scsi_sg_count(scsicmd) == 0) { memcpy(scsi_sglist(scsicmd), buf, cmdrsp->scsi.bufflen); + kfree(buf); return; }
@@ -831,6 +836,7 @@ 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) {
Patches currently in stable-queue which might be from sameer.wadgaonkar@unisys.com are
queue-4.4/staging-unisys-visorhba-fix-s-par-to-boot-with-option-config_vmap_stack-set-to-y.patch