From: Michael Kawano <mkawano@linux.ibm.com>
Date: Thu, 7 Jul 2022 15:57:27 +0200
Subject: vfio/ccw: Remove UUID from s390 debug log
Git-commit: 3566ee1d776c1393393564b2514f9cd52a49c16e
Patch-mainline: v6.0-rc1
References: bsc#1205701
As vfio-ccw devices are created/destroyed, the uuid of the associated
mdevs that are recorded in $S390DBF/vfio_ccw_msg/sprintf get lost.
This is because a pointer to the UUID is stored instead of the UUID
itself, and that memory may have been repurposed if/when the logs are
examined. The result is usually garbage UUID data in the logs, though
there is an outside chance of an oops happening here.
Simply remove the UUID from the traces, as the subchannel number will
provide useful configuration information for problem determination,
and is stored directly into the log instead of a pointer.
As we were the only consumer of mdev_uuid(), remove that too.
Cc: Kirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: Michael Kawano <mkawano@linux.ibm.com>
Fixes: 60e05d1cf0875 ("vfio-ccw: add some logging")
Fixes: b7701dfbf9832 ("vfio-ccw: Register a chp_event callback for vfio-ccw")
[farman: reworded commit message, added Fixes: tags]
Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Link: https://lore.kernel.org/r/20220707135737.720765-2-farman@linux.ibm.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Acked-by: Joerg Roedel <jroedel@suse.de>
---
drivers/s390/cio/vfio_ccw_drv.c | 5 ++---
drivers/s390/cio/vfio_ccw_fsm.c | 26 ++++++++++++--------------
drivers/s390/cio/vfio_ccw_ops.c | 8 ++++----
include/linux/mdev.h | 5 -----
4 files changed, 18 insertions(+), 26 deletions(-)
--- a/drivers/s390/cio/vfio_ccw_drv.c
+++ b/drivers/s390/cio/vfio_ccw_drv.c
@@ -14,7 +14,6 @@
#include <linux/init.h>
#include <linux/device.h>
#include <linux/slab.h>
-#include <linux/uuid.h>
#include <linux/mdev.h>
#include <asm/isc.h>
@@ -358,8 +357,8 @@ static int vfio_ccw_chp_event(struct sub
return 0;
trace_vfio_ccw_chp_event(private->sch->schid, mask, event);
- VFIO_CCW_MSG_EVENT(2, "%pUl (%x.%x.%04x): mask=0x%x event=%d\n",
- mdev_uuid(private->mdev), sch->schid.cssid,
+ VFIO_CCW_MSG_EVENT(2, "sch %x.%x.%04x: mask=0x%x event=%d\n",
+ sch->schid.cssid,
sch->schid.ssid, sch->schid.sch_no,
mask, event);
--- a/drivers/s390/cio/vfio_ccw_fsm.c
+++ b/drivers/s390/cio/vfio_ccw_fsm.c
@@ -10,7 +10,6 @@
*/
#include <linux/vfio.h>
-#include <linux/mdev.h>
#include "ioasm.h"
#include "vfio_ccw_private.h"
@@ -242,7 +241,6 @@ static void fsm_io_request(struct vfio_c
union orb *orb;
union scsw *scsw = &private->scsw;
struct ccw_io_region *io_region = private->io_region;
- struct mdev_device *mdev = private->mdev;
char *errstr = "request";
struct subchannel_id schid = get_schid(private);
@@ -256,8 +254,8 @@ static void fsm_io_request(struct vfio_c
if (orb->tm.b) {
io_region->ret_code = -EOPNOTSUPP;
VFIO_CCW_MSG_EVENT(2,
- "%pUl (%x.%x.%04x): transport mode\n",
- mdev_uuid(mdev), schid.cssid,
+ "sch %x.%x.%04x: transport mode\n",
+ schid.cssid,
schid.ssid, schid.sch_no);
errstr = "transport mode";
goto err_out;
@@ -265,8 +263,8 @@ static void fsm_io_request(struct vfio_c
io_region->ret_code = cp_init(&private->cp, orb);
if (io_region->ret_code) {
VFIO_CCW_MSG_EVENT(2,
- "%pUl (%x.%x.%04x): cp_init=%d\n",
- mdev_uuid(mdev), schid.cssid,
+ "sch %x.%x.%04x: cp_init=%d\n",
+ schid.cssid,
schid.ssid, schid.sch_no,
io_region->ret_code);
errstr = "cp init";
@@ -276,8 +274,8 @@ static void fsm_io_request(struct vfio_c
io_region->ret_code = cp_prefetch(&private->cp);
if (io_region->ret_code) {
VFIO_CCW_MSG_EVENT(2,
- "%pUl (%x.%x.%04x): cp_prefetch=%d\n",
- mdev_uuid(mdev), schid.cssid,
+ "sch %x.%x.%04x: cp_prefetch=%d\n",
+ schid.cssid,
schid.ssid, schid.sch_no,
io_region->ret_code);
errstr = "cp prefetch";
@@ -289,8 +287,8 @@ static void fsm_io_request(struct vfio_c
io_region->ret_code = fsm_io_helper(private);
if (io_region->ret_code) {
VFIO_CCW_MSG_EVENT(2,
- "%pUl (%x.%x.%04x): fsm_io_helper=%d\n",
- mdev_uuid(mdev), schid.cssid,
+ "sch %x.%x.%04x: fsm_io_helper=%d\n",
+ schid.cssid,
schid.ssid, schid.sch_no,
io_region->ret_code);
errstr = "cp fsm_io_helper";
@@ -300,16 +298,16 @@ static void fsm_io_request(struct vfio_c
return;
} else if (scsw->cmd.fctl & SCSW_FCTL_HALT_FUNC) {
VFIO_CCW_MSG_EVENT(2,
- "%pUl (%x.%x.%04x): halt on io_region\n",
- mdev_uuid(mdev), schid.cssid,
+ "sch %x.%x.%04x: halt on io_region\n",
+ schid.cssid,
schid.ssid, schid.sch_no);
/* halt is handled via the async cmd region */
io_region->ret_code = -EOPNOTSUPP;
goto err_out;
} else if (scsw->cmd.fctl & SCSW_FCTL_CLEAR_FUNC) {
VFIO_CCW_MSG_EVENT(2,
- "%pUl (%x.%x.%04x): clear on io_region\n",
- mdev_uuid(mdev), schid.cssid,
+ "sch %x.%x.%04x: clear on io_region\n",
+ schid.cssid,
schid.ssid, schid.sch_no);
/* clear is handled via the async cmd region */
io_region->ret_code = -EOPNOTSUPP;
--- a/drivers/s390/cio/vfio_ccw_ops.c
+++ b/drivers/s390/cio/vfio_ccw_ops.c
@@ -131,8 +131,8 @@ static int vfio_ccw_mdev_probe(struct md
private->mdev = mdev;
private->state = VFIO_CCW_STATE_IDLE;
- VFIO_CCW_MSG_EVENT(2, "mdev %pUl, sch %x.%x.%04x: create\n",
- mdev_uuid(mdev), private->sch->schid.cssid,
+ VFIO_CCW_MSG_EVENT(2, "sch %x.%x.%04x: create\n",
+ private->sch->schid.cssid,
private->sch->schid.ssid,
private->sch->schid.sch_no);
@@ -154,8 +154,8 @@ static void vfio_ccw_mdev_remove(struct
{
struct vfio_ccw_private *private = dev_get_drvdata(mdev->dev.parent);
- VFIO_CCW_MSG_EVENT(2, "mdev %pUl, sch %x.%x.%04x: remove\n",
- mdev_uuid(mdev), private->sch->schid.cssid,
+ VFIO_CCW_MSG_EVENT(2, "sch %x.%x.%04x: remove\n",
+ private->sch->schid.cssid,
private->sch->schid.ssid,
private->sch->schid.sch_no);
--- a/include/linux/mdev.h
+++ b/include/linux/mdev.h
@@ -65,11 +65,6 @@ struct mdev_driver {
struct device_driver driver;
};
-static inline const guid_t *mdev_uuid(struct mdev_device *mdev)
-{
- return &mdev->uuid;
-}
-
extern struct bus_type mdev_bus_type;
int mdev_register_device(struct device *dev, struct mdev_driver *mdev_driver);