Pull fall-through fixes from Gustavo A. R. Silva:
"Mark more switch cases where we are expecting to fall through, fixing
fall-through warnings in arm, sparc64, mips, i386 and s390"
* tag 'Wimplicit-fallthrough-5.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux:
ARM: ep93xx: Mark expected switch fall-through
scsi: fas216: Mark expected switch fall-throughs
pcmcia: db1xxx_ss: Mark expected switch fall-throughs
video: fbdev: omapfb_main: Mark expected switch fall-throughs
watchdog: riowd: Mark expected switch fall-through
s390/net: Mark expected switch fall-throughs
crypto: ux500/crypt: Mark expected switch fall-throughs
watchdog: wdt977: Mark expected switch fall-through
watchdog: scx200_wdt: Mark expected switch fall-through
watchdog: Mark expected switch fall-throughs
ARM: signal: Mark expected switch fall-through
mfd: omap-usb-host: Mark expected switch fall-throughs
mfd: db8500-prcmu: Mark expected switch fall-throughs
ARM: OMAP: dma: Mark expected switch fall-throughs
ARM: alignment: Mark expected switch fall-throughs
ARM: tegra: Mark expected switch fall-through
ARM/hw_breakpoint: Mark expected switch fall-throughs
Mark switch cases where we are expecting to fall through.
This patch fixes the following warnings (Building: s390):
drivers/s390/net/ctcm_fsms.c: In function ‘ctcmpc_chx_attnbusy’:
drivers/s390/net/ctcm_fsms.c:1703:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
if (grp->changed_side == 1) {
^
drivers/s390/net/ctcm_fsms.c:1707:2: note: here
case MPCG_STATE_XID0IOWAIX:
^~~~
drivers/s390/net/ctcm_mpc.c: In function ‘ctc_mpc_alloc_channel’:
drivers/s390/net/ctcm_mpc.c:358:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
if (callback)
^
drivers/s390/net/ctcm_mpc.c:360:2: note: here
case MPCG_STATE_XID0IOWAIT:
^~~~
drivers/s390/net/ctcm_mpc.c: In function ‘mpc_action_timeout’:
drivers/s390/net/ctcm_mpc.c:1469:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
if ((fsm_getstate(rch->fsm) == CH_XID0_PENDING) &&
^
drivers/s390/net/ctcm_mpc.c:1472:2: note: here
default:
^~~~~~~
drivers/s390/net/ctcm_mpc.c: In function ‘mpc_send_qllc_discontact’:
drivers/s390/net/ctcm_mpc.c:2087:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
if (grp->estconnfunc) {
^
drivers/s390/net/ctcm_mpc.c:2092:2: note: here
case MPCG_STATE_FLOWC:
^~~~
drivers/s390/net/qeth_l2_main.c: In function ‘qeth_l2_process_inbound_buffer’:
drivers/s390/net/qeth_l2_main.c:328:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
if (IS_OSN(card)) {
^
drivers/s390/net/qeth_l2_main.c:337:3: note: here
default:
^~~~~~~
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Pull s390 updates from Vasily Gorbik:
- Default configs updates
- Minor qdio cleanup
- Sparse warnings fixes
- Implicit-fallthrough warnings fixes
* tag 's390-5.3-4' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390/zcrypt: adjust switch fall through comments for -Wimplicit-fallthrough
vfio-ccw: make vfio_ccw_async_region_ops static
s390/3215: add switch fall through comment for -Wimplicit-fallthrough
s390/tape: add fallthrough annotations
s390/mm: add fallthrough annotations
s390/mm: make gmap_test_and_clear_dirty_pmd static
s390/kexec: add missing include to machine_kexec_reloc.c
s390/perf: make cf_diag_csd static
s390/lib: add missing include
s390/boot: add missing declarations and includes
s390: update configs
s390: clean up qdio.h
Silence the following warnings when built with -Wimplicit-fallthrough=3
enabled by default since 5.3-rc2:
In file included from ./include/linux/preempt.h:11,
from ./include/linux/spinlock.h:51,
from ./include/linux/mmzone.h:8,
from ./include/linux/gfp.h:6,
from ./include/linux/slab.h:15,
from drivers/s390/crypto/ap_queue.c:13:
drivers/s390/crypto/ap_queue.c: In function 'ap_sm_recv':
./include/linux/list.h:577:2: warning: this statement may fall through [-Wimplicit-fallthrough=]
577 | for (pos = list_first_entry(head, typeof(*pos), member); \
| ^~~
drivers/s390/crypto/ap_queue.c:147:3: note: in expansion of macro 'list_for_each_entry'
147 | list_for_each_entry(ap_msg, &aq->pendingq, list) {
| ^~~~~~~~~~~~~~~~~~~
drivers/s390/crypto/ap_queue.c:155:2: note: here
155 | case AP_RESPONSE_NO_PENDING_REPLY:
| ^~~~
drivers/s390/crypto/zcrypt_msgtype6.c: In function 'convert_response_ep11_xcrb':
drivers/s390/crypto/zcrypt_msgtype6.c:871:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
871 | if (msg->cprbx.cprb_ver_id == 0x04)
| ^
drivers/s390/crypto/zcrypt_msgtype6.c:874:2: note: here
874 | default: /* Unknown response type, this should NEVER EVER happen */
| ^~~~~~~
drivers/s390/crypto/zcrypt_msgtype6.c: In function 'convert_response_rng':
drivers/s390/crypto/zcrypt_msgtype6.c:901:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
901 | if (msg->cprbx.cprb_ver_id == 0x02)
| ^
drivers/s390/crypto/zcrypt_msgtype6.c:907:2: note: here
907 | default: /* Unknown response type, this should NEVER EVER happen */
| ^~~~~~~
drivers/s390/crypto/zcrypt_msgtype6.c: In function 'convert_response_xcrb':
drivers/s390/crypto/zcrypt_msgtype6.c:838:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
838 | if (msg->cprbx.cprb_ver_id == 0x02)
| ^
drivers/s390/crypto/zcrypt_msgtype6.c:844:2: note: here
844 | default: /* Unknown response type, this should NEVER EVER happen */
| ^~~~~~~
drivers/s390/crypto/zcrypt_msgtype6.c: In function 'convert_response_ica':
drivers/s390/crypto/zcrypt_msgtype6.c:801:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
801 | if (msg->cprbx.cprb_ver_id == 0x02)
| ^
drivers/s390/crypto/zcrypt_msgtype6.c:808:2: note: here
808 | default: /* Unknown response type, this should NEVER EVER happen */
| ^~~~~~~
Acked-by: Patrick Steuer <patrick.steuer@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
After getting a storage server event that causes the DASD device driver
to update its unit address configuration during a device shutdown there is
the possibility of an endless loop in the device driver.
In the system log there will be ongoing DASD error messages with RC: -19.
The reason is that the loop starting the ruac request only terminates when
the retry counter is decreased to 0. But in the sleep_on function there are
early exit paths that do not decrease the retry counter.
Prevent an endless loop by handling those cases separately.
Remove the unnecessary do..while loop since the sleep_on function takes
care of retries by itself.
Fixes: 8e09f21574 ("[S390] dasd: add hyper PAV support to DASD device driver, part 1")
Cc: stable@vger.kernel.org # 2.6.25+
Signed-off-by: Stefan Haberland <sth@linux.ibm.com>
Reviewed-by: Jan Hoeppner <hoeppner@linux.ibm.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Since vfio_ccw_async_region_ops is not exported and has no reason to be
globally visible make it static to avoid the following sparse warning:
drivers/s390/cio/vfio_ccw_async.c:73:30: warning: symbol 'vfio_ccw_async_region_ops' was not declared. Should it be static?
Fixes: d5afd5d135 ("vfio-ccw: add handling for async channel instructions")
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Silence the following warning when built with -Wimplicit-fallthrough=3
enabled by default since 5.3-rc2:
drivers/s390/char/con3215.c: In function 'raw3215_irq':
drivers/s390/char/con3215.c:399:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
399 | if (dstat == 0x08)
| ^
drivers/s390/char/con3215.c:401:2: note: here
401 | case 0x04:
| ^~~~
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
The access to airq_areas was racy ever since the adapter interrupts got
introduced to virtio-ccw, but since commit 39c7dcb158 ("virtio/s390:
make airq summary indicators DMA") this became an issue in practice as
well. Namely before that commit the airq_info that got overwritten was
still functional. After that commit however the two infos share a
summary_indicator, which aggravates the situation. Which means
auto-online mechanism occasionally hangs the boot with virtio_blk.
Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
Reported-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Cc: stable@vger.kernel.org
Fixes: 96b14536d9 ("virtio-ccw: virtio-ccw adapter interrupt support.")
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
The IQD mcast queue doesn't support QAOB mode, so skip the
qdio_enable_async_operation() setup call for this queue. This avoids
the allocation of an unneeded QAOB pointer array, and sets up q->use_cq
properly so that drivers are prohibited from using QAOBs for mcast
traffic.
Take this opportunity to streamline the q->use_cq and aob != 0 checks.
The path to qdio_siga_output() is straight-forward, we don't need to
worry about being called with bad operands.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
If the device driver were to send out a full queue's worth of SBALs,
current code would end up discovering the last of those SBALs as PRIMED
and erroneously skip the SIGA-w. This immediately stalls the queue.
Add a check to not attempt fast-requeue in this case. While at it also
make sure that the state of the previous SBAL was successfully extracted
before inspecting it.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Pull SCSI fixes from James Bottomley:
"This is the final round of mostly small fixes in our initial submit.
It's mostly minor fixes and driver updates. The only change of note is
adding a virt_boundary_mask to the SCSI host and host template to
parametrise this for NVMe devices instead of having them do a call in
slave_alloc. It's a fairly straightforward conversion except in the
two NVMe handling drivers that didn't set it who now have a virtual
infinity parameter added"
* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (24 commits)
scsi: megaraid_sas: set an unlimited max_segment_size
scsi: mpt3sas: set an unlimited max_segment_size for SAS 3.0 HBAs
scsi: IB/srp: set virt_boundary_mask in the scsi host
scsi: IB/iser: set virt_boundary_mask in the scsi host
scsi: storvsc: set virt_boundary_mask in the scsi host template
scsi: ufshcd: set max_segment_size in the scsi host template
scsi: core: take the DMA max mapping size into account
scsi: core: add a host / host template field for the virt boundary
scsi: core: Fix race on creating sense cache
scsi: sd_zbc: Fix compilation warning
scsi: libfc: fix null pointer dereference on a null lport
scsi: zfcp: fix GCC compiler warning emitted with -Wmaybe-uninitialized
scsi: zfcp: fix request object use-after-free in send path causing wrong traces
scsi: zfcp: fix request object use-after-free in send path causing seqno errors
scsi: megaraid_sas: Update driver version to 07.710.50.00
scsi: megaraid_sas: Add module parameter for FW Async event logging
scsi: megaraid_sas: Enable msix_load_balance for Invader and later controllers
scsi: megaraid_sas: Fix calculation of target ID
scsi: lpfc: reduce stack size with CONFIG_GCC_PLUGIN_STRUCTLEAK_VERBOSE
scsi: devinfo: BLIST_TRY_VPD_PAGES for SanDisk Cruzer Blade
...
Pull libnvdimm updates from Dan Williams:
"Primarily just the virtio_pmem driver:
- virtio_pmem
The new virtio_pmem facility introduces a paravirtualized
persistent memory device that allows a guest VM to use DAX
mechanisms to access a host-file with host-page-cache. It arranges
for MAP_SYNC to be disabled and instead triggers a host fsync()
when a 'write-cache flush' command is sent to the virtual disk
device.
- Miscellaneous small fixups"
* tag 'libnvdimm-for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
virtio_pmem: fix sparse warning
xfs: disable map_sync for async flush
ext4: disable map_sync for async flush
dax: check synchronous mapping is supported
dm: enable synchronous dax
libnvdimm: add dax_dev sync flag
virtio-pmem: Add virtio pmem driver
libnvdimm: nd_region flush callback support
libnvdimm, namespace: Drop uuid_t implementation detail
There is a small window where it's possible that we could be working
on an interrupt (queued in the workqueue) and setting up a channel
program (i.e allocating memory, pinning pages, translating address).
This can lead to allocating and freeing the channel program at the
same time and can cause memory corruption.
Let's not call cp_free if we are currently processing a channel program.
The only way we know for sure that we don't have a thread setting
up a channel program is when the state is set to VFIO_CCW_STATE_CP_PENDING.
Fixes: d5afd5d135 ("vfio-ccw: add handling for async channel instructions")
Signed-off-by: Farhan Ali <alifm@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <62e87bf67b38dc8d5760586e7c96d400db854ebe.1562854091.git.alifm@linux.ibm.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
The comment is misleading because it tells us that
we should set orb.cmd.c64 before calling ccwchain_calc_length,
otherwise the function ccwchain_calc_length would return an
error. This is not completely accurate.
We want to allow an orb without cmd.c64, and this is fine
as long as the channel program does not use IDALs. But we do
want to reject any channel program that uses IDALs and does
not set the flag, which is what we do in ccwchain_calc_length.
After we have done the ccw processing, we need to set cmd.c64,
as we use IDALs for all translated channel programs.
Also for better code readability let's move the setting of
cmd.c64 within the non error path.
Fixes: fb9e7880af ("vfio: ccw: push down unsupported IDA check")
Signed-off-by: Farhan Ali <alifm@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <f68636106aef0faeb6ce9712584d102d1b315ff8.1562854091.git.alifm@linux.ibm.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Pull more s390 updates from Vasily Gorbik:
- Fix integer overflow during stack frame unwind with invalid
backchain.
- Cleanup unused symbol export in zcrypt code.
- Fix MIO addressing control activation in PCI code and expose its
usage via sysfs.
- Fix kernel image signature verification report presence detection.
- Fix irq registration in vfio-ap code.
- Add CPU measurement counters for newer machines.
- Add base DASD thin provisioning support and code cleanups.
* tag 's390-5.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (21 commits)
s390/unwind: avoid int overflow in outside_of_stack
s390/zcrypt: remove the exporting of ap_query_configuration
s390/pci: add mio_enabled attribute
s390: fix setting of mio addressing control
s390/ipl: Fix detection of has_secure attribute
s390: vfio-ap: fix irq registration
s390/cpumf: Add extended counter set definitions for model 8561 and 8562
s390/dasd: Handle out-of-space constraint
s390/dasd: Add discard support for ESE volumes
s390/dasd: Use ALIGN_DOWN macro
s390/dasd: Make dasd_setup_queue() a discipline function
s390/dasd: Add new ioctl to release space
s390/dasd: Add dasd_sleep_on_queue_interruptible()
s390/dasd: Add missing intensity definition
s390/dasd: Fix whitespace
s390/dasd: Add dynamic formatting support for ESE volumes
s390/dasd: Recognise data for ESE volumes
s390/dasd: Put sub-order definitions in a separate section
s390/dasd: Make layout analysis ESE compatible
s390/dasd: Remove old defines and function
...
Pull driver core and debugfs updates from Greg KH:
"Here is the "big" driver core and debugfs changes for 5.3-rc1
It's a lot of different patches, all across the tree due to some api
changes and lots of debugfs cleanups.
Other than the debugfs cleanups, in this set of changes we have:
- bus iteration function cleanups
- scripts/get_abi.pl tool to display and parse Documentation/ABI
entries in a simple way
- cleanups to Documenatation/ABI/ entries to make them parse easier
due to typos and other minor things
- default_attrs use for some ktype users
- driver model documentation file conversions to .rst
- compressed firmware file loading
- deferred probe fixes
All of these have been in linux-next for a while, with a bunch of
merge issues that Stephen has been patient with me for"
* tag 'driver-core-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (102 commits)
debugfs: make error message a bit more verbose
orangefs: fix build warning from debugfs cleanup patch
ubifs: fix build warning after debugfs cleanup patch
driver: core: Allow subsystems to continue deferring probe
drivers: base: cacheinfo: Ensure cpu hotplug work is done before Intel RDT
arch_topology: Remove error messages on out-of-memory conditions
lib: notifier-error-inject: no need to check return value of debugfs_create functions
swiotlb: no need to check return value of debugfs_create functions
ceph: no need to check return value of debugfs_create functions
sunrpc: no need to check return value of debugfs_create functions
ubifs: no need to check return value of debugfs_create functions
orangefs: no need to check return value of debugfs_create functions
nfsd: no need to check return value of debugfs_create functions
lib: 842: no need to check return value of debugfs_create functions
debugfs: provide pr_fmt() macro
debugfs: log errors when something goes wrong
drivers: s390/cio: Fix compilation warning about const qualifiers
drivers: Add generic helper to match by of_node
driver_find_device: Unify the match function with class_find_device()
bus_find_device: Unify the match callback with class_find_device
...
GCC v9 emits this warning:
CC drivers/s390/scsi/zfcp_erp.o
drivers/s390/scsi/zfcp_erp.c: In function 'zfcp_erp_action_enqueue':
drivers/s390/scsi/zfcp_erp.c:217:26: warning: 'erp_action' may be used uninitialized in this function [-Wmaybe-uninitialized]
217 | struct zfcp_erp_action *erp_action;
| ^~~~~~~~~~
This is a possible false positive case, as also documented in the GCC
documentations:
https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html#index-Wmaybe-uninitialized
The actual code-sequence is like this:
Various callers can invoke the function below with the argument "want"
being one of:
ZFCP_ERP_ACTION_REOPEN_ADAPTER,
ZFCP_ERP_ACTION_REOPEN_PORT_FORCED,
ZFCP_ERP_ACTION_REOPEN_PORT, or
ZFCP_ERP_ACTION_REOPEN_LUN.
zfcp_erp_action_enqueue(want, ...)
...
need = zfcp_erp_required_act(want, ...)
need = want
...
maybe: need = ZFCP_ERP_ACTION_REOPEN_PORT
maybe: need = ZFCP_ERP_ACTION_REOPEN_ADAPTER
...
return need
...
zfcp_erp_setup_act(need, ...)
struct zfcp_erp_action *erp_action; // <== line 217
...
switch(need) {
case ZFCP_ERP_ACTION_REOPEN_LUN:
...
erp_action = &zfcp_sdev->erp_action;
WARN_ON_ONCE(erp_action->port != port); // <== access
...
break;
case ZFCP_ERP_ACTION_REOPEN_PORT:
case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
...
erp_action = &port->erp_action;
WARN_ON_ONCE(erp_action->port != port); // <== access
...
break;
case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
...
erp_action = &adapter->erp_action;
WARN_ON_ONCE(erp_action->port != NULL); // <== access
...
break;
}
...
WARN_ON_ONCE(erp_action->adapter != adapter); // <== access
When zfcp_erp_setup_act() is called, 'need' will never be anything else
than one of the 4 possible enumeration-names that are used in the
switch-case, and 'erp_action' is initialized for every one of them, before
it is used. Thus the warning is a false positive, as documented.
We introduce the extra if{} in the beginning to create an extra code-flow,
so the compiler can be convinced that the switch-case will never see any
other value.
BUG_ON()/BUG() is intentionally not used to not crash anything, should
this ever happen anyway - right now it's impossible, as argued above; and
it doesn't introduce a 'default:' switch-case to retain warnings should
'enum zfcp_erp_act_type' ever be extended and no explicit case be
introduced. See also v5.0 commit 399b6c8bc9 ("scsi: zfcp: drop old
default switch case which might paper over missing case").
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
When tracing instances where we open and close WKA ports, we also pass the
request-ID of the respective FSF command.
But after successfully sending the FSF command we must not use the
request-object anymore, as this might result in an use-after-free (see
"zfcp: fix request object use-after-free in send path causing seqno
errors" ).
To fix this add a new variable that caches the request-ID before sending
the request. This won't change during the hand-off to the FCP channel,
and so it's safe to trace this cached request-ID later, instead of using
the request object.
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
Fixes: d27a7cb919 ("zfcp: trace on request for open and close of WKA port")
Cc: <stable@vger.kernel.org> #2.6.38+
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
With a recent change to our send path for FSF commands we introduced a
possible use-after-free of request-objects, that might further lead to
zfcp crafting bad requests, which the FCP channel correctly complains
about with an error (FSF_PROT_SEQ_NUMB_ERROR). This error is then handled
by an adapter-wide recovery.
The following sequence illustrates the possible use-after-free:
Send Path:
int zfcp_fsf_open_port(struct zfcp_erp_action *erp_action)
{
struct zfcp_fsf_req *req;
...
spin_lock_irq(&qdio->req_q_lock);
// ^^^^^^^^^^^^^^^^
// protects QDIO queue during sending
...
req = zfcp_fsf_req_create(qdio,
FSF_QTCB_OPEN_PORT_WITH_DID,
SBAL_SFLAGS0_TYPE_READ,
qdio->adapter->pool.erp_req);
// ^^^^^^^^^^^^^^^^^^^
// allocation of the request-object
...
retval = zfcp_fsf_req_send(req);
...
spin_unlock_irq(&qdio->req_q_lock);
return retval;
}
static int zfcp_fsf_req_send(struct zfcp_fsf_req *req)
{
struct zfcp_adapter *adapter = req->adapter;
struct zfcp_qdio *qdio = adapter->qdio;
...
zfcp_reqlist_add(adapter->req_list, req);
// ^^^^^^^^^^^^^^^^
// add request to our driver-internal hash-table for tracking
// (protected by separate lock req_list->lock)
...
if (zfcp_qdio_send(qdio, &req->qdio_req)) {
// ^^^^^^^^^^^^^^
// hand-off the request to FCP channel;
// the request can complete at any point now
...
}
/* Don't increase for unsolicited status */
if (!zfcp_fsf_req_is_status_read_buffer(req))
// ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
// possible use-after-free
adapter->fsf_req_seq_no++;
// ^^^^^^^^^^^^^^^^
// because of the use-after-free we might
// miss this accounting, and as follow-up
// this results in the FCP channel error
// FSF_PROT_SEQ_NUMB_ERROR
adapter->req_no++;
return 0;
}
static inline bool
zfcp_fsf_req_is_status_read_buffer(struct zfcp_fsf_req *req)
{
return req->qtcb == NULL;
// ^^^^^^^^^
// possible use-after-free
}
Response Path:
void zfcp_fsf_reqid_check(struct zfcp_qdio *qdio, int sbal_idx)
{
...
struct zfcp_fsf_req *fsf_req;
...
for (idx = 0; idx < QDIO_MAX_ELEMENTS_PER_BUFFER; idx++) {
...
fsf_req = zfcp_reqlist_find_rm(adapter->req_list,
req_id);
// ^^^^^^^^^^^^^^^^^^^^
// remove request from our driver-internal
// hash-table (lock req_list->lock)
...
zfcp_fsf_req_complete(fsf_req);
}
}
static void zfcp_fsf_req_complete(struct zfcp_fsf_req *req)
{
...
if (likely(req->status & ZFCP_STATUS_FSFREQ_CLEANUP))
zfcp_fsf_req_free(req);
// ^^^^^^^^^^^^^^^^^
// free memory for request-object
else
complete(&req->completion);
// ^^^^^^^^
// completion notification for code-paths that wait
// synchronous for the completion of the request; in
// those the memory is freed separately
}
The result of the use-after-free only affects the send path, and can not
lead to any data corruption. In case we miss the sequence-number
accounting, because the memory was already re-purposed, the next FSF
command will fail with said FCP channel error, and we will recover the
whole adapter. This causes no additional errors, but it slows down
traffic. There is a slight chance of the same thing happen again
recursively after the adapter recovery, but so far this has not been seen.
This was seen under z/VM, where the send path might run on a virtual CPU
that gets scheduled away by z/VM, while the return path might still run,
and so create the necessary timing. Running with KASAN can also slow down
the kernel sufficiently to run into this user-after-free, and then see the
report by KASAN.
To fix this, simply pull the test for the sequence-number accounting in
front of the hand-off to the FCP channel (this information doesn't change
during hand-off), but leave the sequence-number accounting itself where it
is.
To make future regressions of the same kind less likely, add comments to
all closely related code-paths.
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
Fixes: f9eca02276 ("scsi: zfcp: drop duplicate fsf_command from zfcp_fsf_req which is also in QTCB header")
Cc: <stable@vger.kernel.org> #5.0+
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Pull SCSI scatter-gather list updates from James Bottomley:
"This topic branch covers a fundamental change in how our sg lists are
allocated to make mq more efficient by reducing the size of the
preallocated sg list.
This necessitates a large number of driver changes because the
previous guarantee that if a driver specified SG_ALL as the size of
its scatter list, it would get a non-chained list and didn't need to
bother with scatterlist iterators is now broken and every driver
*must* use scatterlist iterators.
This was broken out as a separate topic because we need to convert all
the drivers before pulling the trigger and unconverted drivers kept
being found, necessitating a rebase"
* tag 'scsi-sg' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (21 commits)
scsi: core: don't preallocate small SGL in case of NO_SG_CHAIN
scsi: lib/sg_pool.c: clear 'first_chunk' in case of no preallocation
scsi: core: avoid preallocating big SGL for data
scsi: core: avoid preallocating big SGL for protection information
scsi: lib/sg_pool.c: improve APIs for allocating sg pool
scsi: esp: use sg helper to iterate over scatterlist
scsi: NCR5380: use sg helper to iterate over scatterlist
scsi: wd33c93: use sg helper to iterate over scatterlist
scsi: ppa: use sg helper to iterate over scatterlist
scsi: pcmcia: nsp_cs: use sg helper to iterate over scatterlist
scsi: imm: use sg helper to iterate over scatterlist
scsi: aha152x: use sg helper to iterate over scatterlist
scsi: s390: zfcp_fc: use sg helper to iterate over scatterlist
scsi: staging: unisys: visorhba: use sg helper to iterate over scatterlist
scsi: usb: image: microtek: use sg helper to iterate over scatterlist
scsi: pmcraid: use sg helper to iterate over scatterlist
scsi: ipr: use sg helper to iterate over scatterlist
scsi: mvumi: use sg helper to iterate over scatterlist
scsi: lpfc: use sg helper to iterate over scatterlist
scsi: advansys: use sg helper to iterate over scatterlist
...
The function ap_query_configuration is declared static and marked
EXPORT_SYMBOL, which is at best an odd combination. Because the
function is not used outside of the drivers/s390/crypto/ap_bus.c
file it is defined in, this commit removes the EXPORT_SYMBOL() marking.
Link: http://lkml.kernel.org/r/20190709122507.11158-1-efremov@linux.com
Fixes: f1b0a4343c ("s390/zcrypt: Integrate ap_asm.h into include/asm/ap.h.")
Fixes: 050349b5b7 ("s390/zcrypt: externalize AP config info query")
Signed-off-by: Denis Efremov <efremov@linux.com>
Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Linus Torvalds
Gustavo A. R. Silva
Vasily Gorbik
Stefan Haberland
Heiko Carstens
Halil Pasic
Julian Wiedmann
Farhan Ali
Benjamin Block
Denis Efremov