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2019-10-29scsi: zfcp: fix reaction on bit error threshold notificationSteffen Maier
[ Upstream commit 2190168aaea42c31bff7b9a967e7b045f07df095 ] On excessive bit errors for the FCP channel ingress fibre path, the channel notifies us. Previously, we only emitted a kernel message and a trace record. Since performance can become suboptimal with I/O timeouts due to bit errors, we now stop using an FCP device by default on channel notification so multipath on top can timely failover to other paths. A new module parameter zfcp.ber_stop can be used to get zfcp old behavior. User explanation of new kernel message: * Description: * The FCP channel reported that its bit error threshold has been exceeded. * These errors might result from a problem with the physical components * of the local fibre link into the FCP channel. * The problem might be damage or malfunction of the cable or * cable connection between the FCP channel and * the adjacent fabric switch port or the point-to-point peer. * Find details about the errors in the HBA trace for the FCP device. * The zfcp device driver closed down the FCP device * to limit the performance impact from possible I/O command timeouts. * User action: * Check for problems on the local fibre link, ensure that fibre optics are * clean and functional, and all cables are properly plugged. * After the repair action, you can manually recover the FCP device by * writing "0" into its "failed" sysfs attribute. * If recovery through sysfs is not possible, set the CHPID of the device * offline and back online on the service element. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: <stable@vger.kernel.org> #2.6.30+ Link: https://lore.kernel.org/r/20191001104949.42810-1-maier@linux.ibm.com Reviewed-by: Jens Remus <jremus@linux.ibm.com> Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Steffen Maier <maier@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-10-11s390/cio: exclude subchannels with no parent from pseudo checkVasily Gorbik
commit ab5758848039de9a4b249d46e4ab591197eebaf2 upstream. ccw console is created early in start_kernel and used before css is initialized or ccw console subchannel is registered. Until then console subchannel does not have a parent. For that reason assume subchannels with no parent are not pseudo subchannels. This fixes the following kasan finding: BUG: KASAN: global-out-of-bounds in sch_is_pseudo_sch+0x8e/0x98 Read of size 8 at addr 00000000000005e8 by task swapper/0/0 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.3.0-rc8-07370-g6ac43dd12538 #2 Hardware name: IBM 2964 NC9 702 (z/VM 6.4.0) Call Trace: ([<000000000012cd76>] show_stack+0x14e/0x1e0) [<0000000001f7fb44>] dump_stack+0x1a4/0x1f8 [<00000000007d7afc>] print_address_description+0x64/0x3c8 [<00000000007d75f6>] __kasan_report+0x14e/0x180 [<00000000018a2986>] sch_is_pseudo_sch+0x8e/0x98 [<000000000189b950>] cio_enable_subchannel+0x1d0/0x510 [<00000000018cac7c>] ccw_device_recognition+0x12c/0x188 [<0000000002ceb1a8>] ccw_device_enable_console+0x138/0x340 [<0000000002cf1cbe>] con3215_init+0x25e/0x300 [<0000000002c8770a>] console_init+0x68a/0x9b8 [<0000000002c6a3d6>] start_kernel+0x4fe/0x728 [<0000000000100070>] startup_continue+0x70/0xd0 Cc: stable@vger.kernel.org Reviewed-by: Sebastian Ott <sebott@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-11s390/cio: avoid calling strlen on null pointerVasily Gorbik
commit ea298e6ee8b34b3ed4366be7eb799d0650ebe555 upstream. Fix the following kasan finding: BUG: KASAN: global-out-of-bounds in ccwgroup_create_dev+0x850/0x1140 Read of size 1 at addr 0000000000000000 by task systemd-udevd.r/561 CPU: 30 PID: 561 Comm: systemd-udevd.r Tainted: G B Hardware name: IBM 3906 M04 704 (LPAR) Call Trace: ([<0000000231b3db7e>] show_stack+0x14e/0x1a8) [<0000000233826410>] dump_stack+0x1d0/0x218 [<000000023216fac4>] print_address_description+0x64/0x380 [<000000023216f5a8>] __kasan_report+0x138/0x168 [<00000002331b8378>] ccwgroup_create_dev+0x850/0x1140 [<00000002332b618a>] group_store+0x3a/0x50 [<00000002323ac706>] kernfs_fop_write+0x246/0x3b8 [<00000002321d409a>] vfs_write+0x132/0x450 [<00000002321d47da>] ksys_write+0x122/0x208 [<0000000233877102>] system_call+0x2a6/0x2c8 Triggered by: openat(AT_FDCWD, "/sys/bus/ccwgroup/drivers/qeth/group", O_WRONLY|O_CREAT|O_TRUNC|O_CLOEXEC, 0666) = 16 write(16, "0.0.bd00,0.0.bd01,0.0.bd02", 26) = 26 The problem is that __get_next_id in ccwgroup_create_dev might set "buf" buffer pointer to NULL and explicit check for that is required. Cc: stable@vger.kernel.org Reviewed-by: Sebastian Ott <sebott@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-08-16s390/qdio: add sanity checks to the fast-requeue pathJulian Wiedmann
[ Upstream commit a6ec414a4dd529eeac5c3ea51c661daba3397108 ] 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> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-08-16vfio-ccw: Set pa_nr to 0 if memory allocation fails for pa_iova_pfnFarhan Ali
[ Upstream commit c1ab69268d124ebdbb3864580808188ccd3ea355 ] So we don't call try to call vfio_unpin_pages() incorrectly. Fixes: 0a19e61e6d4c ("vfio: ccw: introduce channel program interfaces") Signed-off-by: Farhan Ali <alifm@linux.ibm.com> Reviewed-by: Eric Farman <farman@linux.ibm.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Message-Id: <33a89467ad6369196ae6edf820cbcb1e2d8d050c.1562854091.git.alifm@linux.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-08-06s390/dasd: fix endless loop after read unit address configurationStefan Haberland
commit 41995342b40c418a47603e1321256d2c4a2ed0fb upstream. 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: 8e09f21574ea ("[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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-08-06scsi: zfcp: fix GCC compiler warning emitted with -Wmaybe-uninitializedBenjamin Block
[ Upstream commit 484647088826f2f651acbda6bcf9536b8a466703 ] 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 399b6c8bc9f7 ("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> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-07-31s390/qdio: handle PENDING state for QEBSM devicesJulian Wiedmann
[ Upstream commit 04310324c6f482921c071444833e70fe861b73d9 ] When a CQ-enabled device uses QEBSM for SBAL state inspection, get_buf_states() can return the PENDING state for an Output Queue. get_outbound_buffer_frontier() isn't prepared for this, and any PENDING buffer will permanently stall all further completion processing on this Queue. This isn't a concern for non-QEBSM devices, as get_buf_states() for such devices will manually turn PENDING buffers into EMPTY ones. Fixes: 104ea556ee7f ("qdio: support asynchronous delivery of storage blocks") Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-07-21s390/qdio: don't touch the dsci in tiqdio_add_input_queues()Julian Wiedmann
commit ac6639cd3db607d386616487902b4cc1850a7be5 upstream. Current code sets the dsci to 0x00000080. Which doesn't make any sense, as the indicator area is located in the _left-most_ byte. Worse: if the dsci is the _shared_ indicator, this potentially clears the indication of activity for a _different_ device. tiqdio_thinint_handler() will then have no reason to call that device's IRQ handler, and the device ends up stalling. Fixes: d0c9d4a89fff ("[S390] qdio: set correct bit in dsci") Cc: <stable@vger.kernel.org> Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-21s390/qdio: (re-)initialize tiqdio list entriesJulian Wiedmann
commit e54e4785cb5cb4896cf4285964aeef2125612fb2 upstream. When tiqdio_remove_input_queues() removes a queue from the tiq_list as part of qdio_shutdown(), it doesn't re-initialize the queue's list entry and the prev/next pointers go stale. If a subsequent qdio_establish() fails while sending the ESTABLISH cmd, it calls qdio_shutdown() again in QDIO_IRQ_STATE_ERR state and tiqdio_remove_input_queues() will attempt to remove the queue entry a second time. This dereferences the stale pointers, and bad things ensue. Fix this by re-initializing the list entry after removing it from the list. For good practice also initialize the list entry when the queue is first allocated, and remove the quirky checks that papered over this omission. Note that prior to commit e521813468f7 ("s390/qdio: fix access to uninitialized qdio_q fields"), these checks were bogus anyway. setup_queues_misc() clears the whole queue struct, and thus needs to re-init the prev/next pointers as well. Fixes: 779e6e1c724d ("[S390] qdio: new qdio driver.") Cc: <stable@vger.kernel.org> Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-25s390/qeth: fix VLAN attribute in bridge_hostnotify udev eventAlexandra Winter
[ Upstream commit 335726195e460cb6b3f795b695bfd31f0ea70ef0 ] Enabling sysfs attribute bridge_hostnotify triggers a series of udev events for the MAC addresses of all currently connected peers. In case no VLAN is set for a peer, the device reports the corresponding MAC addresses with VLAN ID 4096. This currently results in attribute VLAN=4096 for all non-VLAN interfaces in the initial series of events after host-notify is enabled. Instead, no VLAN attribute should be reported in the udev event for non-VLAN interfaces. Only the initial events face this issue. For dynamic changes that are reported later, the device uses a validity flag. This also changes the code so that it now sets the VLAN attribute for MAC addresses with VID 0. On Linux, no qeth interface will ever be registered with VID 0: Linux kernel registers VID 0 on all network interfaces initially, but qeth will drop .ndo_vlan_rx_add_vid for VID 0. Peers with other OSs could register MACs with VID 0. Fixes: 9f48b9db9a22 ("qeth: bridgeport support - address notifications") Signed-off-by: Alexandra Winter <wintera@linux.ibm.com> Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-06-09scsi: zfcp: fix to prevent port_remove with pure auto scan LUNs (only sdevs)Steffen Maier
commit ef4021fe5fd77ced0323cede27979d80a56211ca upstream. When the user tries to remove a zfcp port via sysfs, we only rejected it if there are zfcp unit children under the port. With purely automatically scanned LUNs there are no zfcp units but only SCSI devices. In such cases, the port_remove erroneously continued. We close the port and this implicitly closes all LUNs under the port. The SCSI devices survive with their private zfcp_scsi_dev still holding a reference to the "removed" zfcp_port (still allocated but invisible in sysfs) [zfcp_get_port_by_wwpn in zfcp_scsi_slave_alloc]. This is not a problem as long as the fc_rport stays blocked. Once (auto) port scan brings back the removed port, we unblock its fc_rport again by design. However, there is no mechanism that would recover (open) the LUNs under the port (no "ersfs_3" without zfcp_unit [zfcp_erp_strategy_followup_success]). Any pending or new I/O to such LUN leads to repeated: Done: NEEDS_RETRY Result: hostbyte=DID_IMM_RETRY driverbyte=DRIVER_OK See also v4.10 commit 6f2ce1c6af37 ("scsi: zfcp: fix rport unblock race with LUN recovery"). Even a manual LUN recovery (echo 0 > /sys/bus/scsi/devices/H:C:T:L/zfcp_failed) does not help, as the LUN links to the old "removed" port which remains to lack ZFCP_STATUS_COMMON_RUNNING [zfcp_erp_required_act]. The only workaround is to first ensure that the fc_rport is blocked (e.g. port_remove again in case it was re-discovered by (auto) port scan), then delete the SCSI devices, and finally re-discover by (auto) port scan. The port scan includes an fc_rport unblock, which in turn triggers a new scan on the scsi target to freshly get new pure auto scan LUNs. Fix this by rejecting port_remove also if there are SCSI devices (even without any zfcp_unit) under this port. Re-use mechanics from v3.7 commit d99b601b6338 ("[SCSI] zfcp: restore refcount check on port_remove"). However, we have to give up zfcp_sysfs_port_units_mutex earlier in unit_add to prevent a deadlock with scsi_host scan taking shost->scan_mutex first and then zfcp_sysfs_port_units_mutex now in our zfcp_scsi_slave_alloc(). Signed-off-by: Steffen Maier <maier@linux.ibm.com> Fixes: b62a8d9b45b9 ("[SCSI] zfcp: Use SCSI device data zfcp scsi dev instead of zfcp unit") Fixes: f8210e34887e ("[SCSI] zfcp: Allow midlayer to scan for LUNs when running in NPIV mode") Cc: <stable@vger.kernel.org> #2.6.37+ Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-09scsi: zfcp: fix missing zfcp_port reference put on -EBUSY from port_removeSteffen Maier
commit d27e5e07f9c49bf2a6a4ef254ce531c1b4fb5a38 upstream. With this early return due to zfcp_unit child(ren), we don't use the zfcp_port reference from the earlier zfcp_get_port_by_wwpn() anymore and need to put it. Signed-off-by: Steffen Maier <maier@linux.ibm.com> Fixes: d99b601b6338 ("[SCSI] zfcp: restore refcount check on port_remove") Cc: <stable@vger.kernel.org> #3.7+ Reviewed-by: Jens Remus <jremus@linux.ibm.com> Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-31vfio-ccw: Prevent quiesce function going into an infinite loopFarhan Ali
[ Upstream commit d1ffa760d22aa1d8190478e5ef555c59a771db27 ] The quiesce function calls cio_cancel_halt_clear() and if we get an -EBUSY we go into a loop where we: - wait for any interrupts - flush all I/O in the workqueue - retry cio_cancel_halt_clear During the period where we are waiting for interrupts or flushing all I/O, the channel subsystem could have completed a halt/clear action and turned off the corresponding activity control bits in the subchannel status word. This means the next time we call cio_cancel_halt_clear(), we will again start by calling cancel subchannel and so we can be stuck between calling cancel and halt forever. Rather than calling cio_cancel_halt_clear() immediately after waiting, let's try to disable the subchannel. If we succeed in disabling the subchannel then we know nothing else can happen with the device. Suggested-by: Eric Farman <farman@linux.ibm.com> Signed-off-by: Farhan Ali <alifm@linux.ibm.com> Message-Id: <4d5a4b98ab1b41ac6131b5c36de18b76c5d66898.1555449329.git.alifm@linux.ibm.com> Reviewed-by: Eric Farman <farman@linux.ibm.com> Acked-by: Halil Pasic <pasic@linux.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-05-31s390: cio: fix cio_irb declarationArnd Bergmann
[ Upstream commit e91012ee855ad9f5ef2ab106a3de51db93fe4d0c ] clang points out that the declaration of cio_irb does not match the definition exactly, it is missing the alignment attribute: ../drivers/s390/cio/cio.c:50:1: warning: section does not match previous declaration [-Wsection] DEFINE_PER_CPU_ALIGNED(struct irb, cio_irb); ^ ../include/linux/percpu-defs.h:150:2: note: expanded from macro 'DEFINE_PER_CPU_ALIGNED' DEFINE_PER_CPU_SECTION(type, name, PER_CPU_ALIGNED_SECTION) \ ^ ../include/linux/percpu-defs.h:93:9: note: expanded from macro 'DEFINE_PER_CPU_SECTION' extern __PCPU_ATTRS(sec) __typeof__(type) name; \ ^ ../include/linux/percpu-defs.h:49:26: note: expanded from macro '__PCPU_ATTRS' __percpu __attribute__((section(PER_CPU_BASE_SECTION sec))) \ ^ ../drivers/s390/cio/cio.h:118:1: note: previous attribute is here DECLARE_PER_CPU(struct irb, cio_irb); ^ ../include/linux/percpu-defs.h:111:2: note: expanded from macro 'DECLARE_PER_CPU' DECLARE_PER_CPU_SECTION(type, name, "") ^ ../include/linux/percpu-defs.h:87:9: note: expanded from macro 'DECLARE_PER_CPU_SECTION' extern __PCPU_ATTRS(sec) __typeof__(type) name ^ ../include/linux/percpu-defs.h:49:26: note: expanded from macro '__PCPU_ATTRS' __percpu __attribute__((section(PER_CPU_BASE_SECTION sec))) \ ^ Use DECLARE_PER_CPU_ALIGNED() here, to make the two match. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Sebastian Ott <sebott@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-05-31s390: zcrypt: initialize variables before_useArnd Bergmann
[ Upstream commit 913140e221567b3ecd21b4242257a7e3fa279026 ] The 'func_code' variable gets printed in debug statements without a prior initialization in multiple functions, as reported when building with clang: drivers/s390/crypto/zcrypt_api.c:659:6: warning: variable 'func_code' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized] if (mex->outputdatalength < mex->inputdatalength) { ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/s390/crypto/zcrypt_api.c:725:29: note: uninitialized use occurs here trace_s390_zcrypt_rep(mex, func_code, rc, ^~~~~~~~~ drivers/s390/crypto/zcrypt_api.c:659:2: note: remove the 'if' if its condition is always false if (mex->outputdatalength < mex->inputdatalength) { ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/s390/crypto/zcrypt_api.c:654:24: note: initialize the variable 'func_code' to silence this warning unsigned int func_code; ^ Add initializations to all affected code paths to shut up the warning and make the warning output consistent. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-05-31vfio-ccw: Release any channel program when releasing/removing vfio-ccw mdevFarhan Ali
[ Upstream commit b49bdc8602b7c9c7a977758bee4125683f73e59f ] When releasing the vfio-ccw mdev, we currently do not release any existing channel program and its pinned pages. This can lead to the following warning: [1038876.561565] WARNING: CPU: 2 PID: 144727 at drivers/vfio/vfio_iommu_type1.c:1494 vfio_sanity_check_pfn_list+0x40/0x70 [vfio_iommu_type1] .... 1038876.561921] Call Trace: [1038876.561935] ([<00000009897fb870>] 0x9897fb870) [1038876.561949] [<000003ff8013bf62>] vfio_iommu_type1_detach_group+0xda/0x2f0 [vfio_iommu_type1] [1038876.561965] [<000003ff8007b634>] __vfio_group_unset_container+0x64/0x190 [vfio] [1038876.561978] [<000003ff8007b87e>] vfio_group_put_external_user+0x26/0x38 [vfio] [1038876.562024] [<000003ff806fc608>] kvm_vfio_group_put_external_user+0x40/0x60 [kvm] [1038876.562045] [<000003ff806fcb9e>] kvm_vfio_destroy+0x5e/0xd0 [kvm] [1038876.562065] [<000003ff806f63fc>] kvm_put_kvm+0x2a4/0x3d0 [kvm] [1038876.562083] [<000003ff806f655e>] kvm_vm_release+0x36/0x48 [kvm] [1038876.562098] [<00000000003c2dc4>] __fput+0x144/0x228 [1038876.562113] [<000000000016ee82>] task_work_run+0x8a/0xd8 [1038876.562125] [<000000000014c7a8>] do_exit+0x5d8/0xd90 [1038876.562140] [<000000000014d084>] do_group_exit+0xc4/0xc8 [1038876.562155] [<000000000015c046>] get_signal+0x9ae/0xa68 [1038876.562169] [<0000000000108d66>] do_signal+0x66/0x768 [1038876.562185] [<0000000000b9e37e>] system_call+0x1ea/0x2d8 [1038876.562195] 2 locks held by qemu-system-s39/144727: [1038876.562205] #0: 00000000537abaf9 (&container->group_lock){++++}, at: __vfio_group_unset_container+0x3c/0x190 [vfio] [1038876.562230] #1: 00000000670008b5 (&iommu->lock){+.+.}, at: vfio_iommu_type1_detach_group+0x36/0x2f0 [vfio_iommu_type1] [1038876.562250] Last Breaking-Event-Address: [1038876.562262] [<000003ff8013aa24>] vfio_sanity_check_pfn_list+0x3c/0x70 [vfio_iommu_type1] [1038876.562272] irq event stamp: 4236481 [1038876.562287] hardirqs last enabled at (4236489): [<00000000001cee7a>] console_unlock+0x6d2/0x740 [1038876.562299] hardirqs last disabled at (4236496): [<00000000001ce87e>] console_unlock+0xd6/0x740 [1038876.562311] softirqs last enabled at (4234162): [<0000000000b9fa1e>] __do_softirq+0x556/0x598 [1038876.562325] softirqs last disabled at (4234153): [<000000000014e4cc>] irq_exit+0xac/0x108 [1038876.562337] ---[ end trace 6c96d467b1c3ca06 ]--- Similarly we do not free the channel program when we are removing the vfio-ccw device. Let's fix this by resetting the device and freeing the channel program and pinned pages in the release path. For the remove path we can just quiesce the device, since in the remove path the mediated device is going away for good and so we don't need to do a full reset. Signed-off-by: Farhan Ali <alifm@linux.ibm.com> Message-Id: <ae9f20dc8873f2027f7b3c5d2aaa0bdfe06850b8.1554756534.git.alifm@linux.ibm.com> Acked-by: Eric Farman <farman@linux.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-05-31vfio-ccw: Do not call flush_workqueue while holding the spinlockFarhan Ali
[ Upstream commit cea5dde42a83b5f0a039da672f8686455936b8d8 ] Currently we call flush_workqueue while holding the subchannel spinlock. But flush_workqueue function can go to sleep, so do not call the function while holding the spinlock. Fixes the following bug: [ 285.203430] BUG: scheduling while atomic: bash/14193/0x00000002 [ 285.203434] INFO: lockdep is turned off. .... [ 285.203485] Preemption disabled at: [ 285.203488] [<000003ff80243e5c>] vfio_ccw_sch_quiesce+0xbc/0x120 [vfio_ccw] [ 285.203496] CPU: 7 PID: 14193 Comm: bash Tainted: G W .... [ 285.203504] Call Trace: [ 285.203510] ([<0000000000113772>] show_stack+0x82/0xd0) [ 285.203514] [<0000000000b7a102>] dump_stack+0x92/0xd0 [ 285.203518] [<000000000017b8be>] __schedule_bug+0xde/0xf8 [ 285.203524] [<0000000000b95b5a>] __schedule+0x7a/0xc38 [ 285.203528] [<0000000000b9678a>] schedule+0x72/0xb0 [ 285.203533] [<0000000000b9bfbc>] schedule_timeout+0x34/0x528 [ 285.203538] [<0000000000b97608>] wait_for_common+0x118/0x1b0 [ 285.203544] [<0000000000166d6a>] flush_workqueue+0x182/0x548 [ 285.203550] [<000003ff80243e6e>] vfio_ccw_sch_quiesce+0xce/0x120 [vfio_ccw] [ 285.203556] [<000003ff80245278>] vfio_ccw_mdev_reset+0x38/0x70 [vfio_ccw] [ 285.203562] [<000003ff802458b0>] vfio_ccw_mdev_remove+0x40/0x78 [vfio_ccw] [ 285.203567] [<000003ff801a499c>] mdev_device_remove_ops+0x3c/0x80 [mdev] [ 285.203573] [<000003ff801a4d5c>] mdev_device_remove+0xc4/0x130 [mdev] [ 285.203578] [<000003ff801a5074>] remove_store+0x6c/0xa8 [mdev] [ 285.203582] [<000000000046f494>] kernfs_fop_write+0x14c/0x1f8 [ 285.203588] [<00000000003c1530>] __vfs_write+0x38/0x1a8 [ 285.203593] [<00000000003c187c>] vfs_write+0xb4/0x198 [ 285.203597] [<00000000003c1af2>] ksys_write+0x5a/0xb0 [ 285.203601] [<0000000000b9e270>] system_call+0xdc/0x2d8 Signed-off-by: Farhan Ali <alifm@linux.ibm.com> Reviewed-by: Eric Farman <farman@linux.ibm.com> Reviewed-by: Pierre Morel <pmorel@linux.ibm.com> Message-Id: <626bab8bb2958ae132452e1ddaf1b20882ad5a9d.1554756534.git.alifm@linux.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-05-16s390: ctcm: fix ctcm_new_device error return codeArnd Bergmann
[ Upstream commit 27b141fc234a3670d21bd742c35d7205d03cbb3a ] clang points out that the return code from this function is undefined for one of the error paths: ../drivers/s390/net/ctcm_main.c:1595:7: warning: variable 'result' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized] if (priv->channel[direction] == NULL) { ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ../drivers/s390/net/ctcm_main.c:1638:9: note: uninitialized use occurs here return result; ^~~~~~ ../drivers/s390/net/ctcm_main.c:1595:3: note: remove the 'if' if its condition is always false if (priv->channel[direction] == NULL) { ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ../drivers/s390/net/ctcm_main.c:1539:12: note: initialize the variable 'result' to silence this warning int result; ^ Make it return -ENODEV here, as in the related failure cases. gcc has a known bug in underreporting some of these warnings when it has already eliminated the assignment of the return code based on some earlier optimization step. Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-05-16s390/pkey: add one more argument space for debug feature entryHarald Freudenberger
[ Upstream commit 6b1f16ba730d4c0cda1247568c3a1bf4fa3a2f2f ] The debug feature entries have been used with up to 5 arguents (including the pointer to the format string) but there was only space reserved for 4 arguemnts. So now the registration does reserve space for 5 times a long value. This fixes a sometime appearing weired value as the last value of an debug feature entry like this: ... pkey_sec2protkey zcrypt_send_cprb (cardnr=10 domain=12) failed with errno -2143346254 Signed-off-by: Harald Freudenberger <freude@linux.ibm.com> Reported-by: Christian Rund <Christian.Rund@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-05-16s390/3270: fix lockdep false positive on view->lockMartin Schwidefsky
[ Upstream commit 5712f3301a12c0c3de9cc423484496b0464f2faf ] The spinlock in the raw3270_view structure is used by con3270, tty3270 and fs3270 in different ways. For con3270 the lock can be acquired in irq context, for tty3270 and fs3270 the highest context is bh. Lockdep sees the view->lock as a single class and if the 3270 driver is used for the console the following message is generated: WARNING: inconsistent lock state 5.1.0-rc3-05157-g5c168033979d #12 Not tainted -------------------------------- inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage. swapper/0/1 [HC0[0]:SC1[1]:HE1:SE0] takes: (____ptrval____) (&(&view->lock)->rlock){?.-.}, at: tty3270_update+0x7c/0x330 Introduce a lockdep subclass for the view lock to distinguish bh from irq locks. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-05-16s390/dasd: Fix capacity calculation for large volumesPeter Oberparleiter
[ Upstream commit 2cc9637ce825f3a9f51f8f78af7474e9e85bfa5f ] The DASD driver incorrectly limits the maximum number of blocks of ECKD DASD volumes to 32 bit numbers. Volumes with a capacity greater than 2^32-1 blocks are incorrectly recognized as smaller volumes. This results in the following volume capacity limits depending on the formatted block size: BLKSIZE MAX_GB MAX_CYL 512 2047 5843492 1024 4095 8676701 2048 8191 13634816 4096 16383 23860929 The same problem occurs when a volume with more than 17895697 cylinders is accessed in raw-track-access mode. Fix this problem by adding an explicit type cast when calculating the maximum number of blocks. Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com> Reviewed-by: Stefan Haberland <sth@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-05-04scsi: zfcp: reduce flood of fcrscn1 trace records on multi-element RSCNSteffen Maier
[ Upstream commit c8206579175c34a2546de8a74262456278a7795a ] If an incoming ELS of type RSCN contains more than one element, zfcp suboptimally causes repeated erp trigger NOP trace records for each previously failed port. These could be ports that went away. It loops over each RSCN element, and for each of those in an inner loop over all zfcp_ports. The trigger to recover failed ports should be just the reception of some RSCN, no matter how many elements it has. So we can loop over failed ports separately, and only then loop over each RSCN element to handle the non-failed ports. The call chain was: zfcp_fc_incoming_rscn for (i = 1; i < no_entries; i++) _zfcp_fc_incoming_rscn list_for_each_entry(port, &adapter->port_list, list) if (masked port->d_id match) zfcp_fc_test_link if (!port->d_id) zfcp_erp_port_reopen "fcrscn1" <=== In order the reduce the "flooding" of the REC trace area in such cases, we factor out handling the failed ports to be outside of the entries loop: zfcp_fc_incoming_rscn if (no_entries > 1) <=== list_for_each_entry(port, &adapter->port_list, list) <=== if (!port->d_id) zfcp_erp_port_reopen "fcrscn1" <=== for (i = 1; i < no_entries; i++) _zfcp_fc_incoming_rscn list_for_each_entry(port, &adapter->port_list, list) if (masked port->d_id match) zfcp_fc_test_link Abbreviated example trace records before this code change: Tag : fcrscn1 WWPN : 0x500507630310d327 ERP want : 0x02 ERP need : 0x02 Tag : fcrscn1 WWPN : 0x500507630310d327 ERP want : 0x02 ERP need : 0x00 NOP => superfluous trace record The last trace entry repeats if there are more than 2 RSCN elements. Signed-off-by: Steffen Maier <maier@linux.ibm.com> Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Reviewed-by: Jens Remus <jremus@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin (Microsoft) <sashal@kernel.org>
2019-05-04s390/qeth: fix race when initializing the IP address tableJulian Wiedmann
[ Upstream commit 7221b727f0079a32aca91f657141e1de564d4b97 ] The ucast IP table is utilized by some of the L3-specific sysfs attributes that qeth_l3_create_device_attributes() provides. So initialize the table _before_ registering the attributes. Fixes: ebccc7397e4a ("s390/qeth: add missing hash table initializations") Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin (Microsoft) <sashal@kernel.org>
2019-04-03vfio: ccw: only free cp on final interruptCornelia Huck
commit 50b7f1b7236bab08ebbbecf90521e84b068d7a17 upstream. When we get an interrupt for a channel program, it is not necessarily the final interrupt; for example, the issuing guest may request an intermediate interrupt by specifying the program-controlled-interrupt flag on a ccw. We must not switch the state to idle if the interrupt is not yet final; even more importantly, we must not free the translated channel program if the interrupt is not yet final, or the host can crash during cp rewind. Fixes: e5f84dbaea59 ("vfio: ccw: return I/O results asynchronously") Cc: stable@vger.kernel.org # v4.12+ Reviewed-by: Eric Farman <farman@linux.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-03scsi: zfcp: fix scsi_eh host reset with port_forced ERP for non-NPIV FCP devicesSteffen Maier
commit 242ec1455151267fe35a0834aa9038e4c4670884 upstream. Suppose more than one non-NPIV FCP device is active on the same channel. Send I/O to storage and have some of the pending I/O run into a SCSI command timeout, e.g. due to bit errors on the fibre. Now the error situation stops. However, we saw FCP requests continue to timeout in the channel. The abort will be successful, but the subsequent TUR fails. Scsi_eh starts. The LUN reset fails. The target reset fails. The host reset only did an FCP device recovery. However, for non-NPIV FCP devices, this does not close and reopen ports on the SAN-side if other non-NPIV FCP device(s) share the same open ports. In order to resolve the continuing FCP request timeouts, we need to explicitly close and reopen ports on the SAN-side. This was missing since the beginning of zfcp in v2.6.0 history commit ea127f975424 ("[PATCH] s390 (7/7): zfcp host adapter."). Note: The FSF requests for forced port reopen could run into FSF request timeouts due to other reasons. This would trigger an internal FCP device recovery. Pending forced port reopen recoveries would get dismissed. So some ports might not get fully reopened during this host reset handler. However, subsequent I/O would trigger the above described escalation and eventually all ports would be forced reopen to resolve any continuing FCP request timeouts due to earlier bit errors. Signed-off-by: Steffen Maier <maier@linux.ibm.com> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: <stable@vger.kernel.org> #3.0+ Reviewed-by: Jens Remus <jremus@linux.ibm.com> Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-03scsi: zfcp: fix rport unblock if deleted SCSI devices on Scsi_HostSteffen Maier
commit fe67888fc007a76b81e37da23ce5bd8fb95890b0 upstream. An already deleted SCSI device can exist on the Scsi_Host and remain there because something still holds a reference. A new SCSI device with the same H:C:T:L and FCP device, target port WWPN, and FCP LUN can be created. When we try to unblock an rport, we still find the deleted SCSI device and return early because the zfcp_scsi_dev of that SCSI device is not ZFCP_STATUS_COMMON_UNBLOCKED. Hence we miss to unblock the rport, even if the new proper SCSI device would be in good state. Therefore, skip deleted SCSI devices when iterating the sdevs of the shost. [cf. __scsi_device_lookup{_by_target}() or scsi_device_get()] The following abbreviated trace sequence can indicate such problem: Area : REC Tag : ersfs_3 LUN : 0x4045400300000000 WWPN : 0x50050763031bd327 LUN status : 0x40000000 not ZFCP_STATUS_COMMON_UNBLOCKED Ready count : n not incremented yet Running count : 0x00000000 ERP want : 0x01 ERP need : 0xc1 ZFCP_ERP_ACTION_NONE Area : REC Tag : ersfs_3 LUN : 0x4045400300000000 WWPN : 0x50050763031bd327 LUN status : 0x41000000 Ready count : n+1 Running count : 0x00000000 ERP want : 0x01 ERP need : 0x01 ... Area : REC Level : 4 only with increased trace level Tag : ertru_l LUN : 0x4045400300000000 WWPN : 0x50050763031bd327 LUN status : 0x40000000 Request ID : 0x0000000000000000 ERP status : 0x01800000 ERP step : 0x1000 ERP action : 0x01 ERP count : 0x00 NOT followed by a trace record with tag "scpaddy" for WWPN 0x50050763031bd327. Signed-off-by: Steffen Maier <maier@linux.ibm.com> Fixes: 6f2ce1c6af37 ("scsi: zfcp: fix rport unblock race with LUN recovery") Cc: <stable@vger.kernel.org> #2.6.32+ Reviewed-by: Jens Remus <jremus@linux.ibm.com> Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-03-23s390/virtio: handle find on invalid queue gracefullyHalil Pasic
commit 3438b2c039b4bf26881786a1f3450f016d66ad11 upstream. A queue with a capacity of zero is clearly not a valid virtio queue. Some emulators report zero queue size if queried with an invalid queue index. Instead of crashing in this case let us just return -ENOENT. To make that work properly, let us fix the notifier cleanup logic as well. Cc: stable@vger.kernel.org Signed-off-by: Halil Pasic <pasic@linux.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-03-23s390/dasd: fix using offset into zero size array errorStefan Haberland
[ Upstream commit 4a8ef6999bce998fa5813023a9a6b56eea329dba ] Dan Carpenter reported the following: The patch 52898025cf7d: "[S390] dasd: security and PSF update patch for EMC CKD ioctl" from Mar 8, 2010, leads to the following static checker warning: drivers/s390/block/dasd_eckd.c:4486 dasd_symm_io() error: using offset into zero size array 'psf_data[]' drivers/s390/block/dasd_eckd.c 4458 /* Copy parms from caller */ 4459 rc = -EFAULT; 4460 if (copy_from_user(&usrparm, argp, sizeof(usrparm))) ^^^^^^^ The user can specify any "usrparm.psf_data_len". They choose zero by mistake. 4461 goto out; 4462 if (is_compat_task()) { 4463 /* Make sure pointers are sane even on 31 bit. */ 4464 rc = -EINVAL; 4465 if ((usrparm.psf_data >> 32) != 0) 4466 goto out; 4467 if ((usrparm.rssd_result >> 32) != 0) 4468 goto out; 4469 usrparm.psf_data &= 0x7fffffffULL; 4470 usrparm.rssd_result &= 0x7fffffffULL; 4471 } 4472 /* alloc I/O data area */ 4473 psf_data = kzalloc(usrparm.psf_data_len, GFP_KERNEL | GFP_DMA); 4474 rssd_result = kzalloc(usrparm.rssd_result_len, GFP_KERNEL | GFP_DMA); 4475 if (!psf_data || !rssd_result) { kzalloc() returns a ZERO_SIZE_PTR (0x16). 4476 rc = -ENOMEM; 4477 goto out_free; 4478 } 4479 4480 /* get syscall header from user space */ 4481 rc = -EFAULT; 4482 if (copy_from_user(psf_data, 4483 (void __user *)(unsigned long) usrparm.psf_data, 4484 usrparm.psf_data_len)) That all works great. 4485 goto out_free; 4486 psf0 = psf_data[0]; 4487 psf1 = psf_data[1]; But now we're assuming that "->psf_data_len" was at least 2 bytes. Fix this by checking the user specified length psf_data_len. Fixes: 52898025cf7d ("[S390] dasd: security and PSF update patch for EMC CKD ioctl") Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Stefan Haberland <sth@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-03-13s390/qeth: fix use-after-free in error pathJulian Wiedmann
[ Upstream commit afa0c5904ba16d59b0454f7ee4c807dae350f432 ] The error path in qeth_alloc_qdio_buffers() that takes care of cleaning up the Output Queues is buggy. It first frees the queue, but then calls qeth_clear_outq_buffers() with that very queue struct. Make the call to qeth_clear_outq_buffers() part of the free action (in the correct order), and while at it fix the naming of the helper. Fixes: 0da9581ddb0f ("qeth: exploit asynchronous delivery of storage blocks") Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Reviewed-by: Alexandra Winter <wintera@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-02-12s390/zcrypt: improve special ap message cmd handlingHarald Freudenberger
[ Upstream commit be534791011100d204602e2e0496e9e6ce8edf63 ] There exist very few ap messages which need to have the 'special' flag enabled. This flag tells the firmware layer to do some pre- and maybe postprocessing. However, it may happen that this special flag is enabled but the firmware is unable to deal with this kind of message and thus returns with reply code 0x41. For example older firmware may not know the newest messages triggered by the zcrypt device driver and thus react with reject and the named reply code. Unfortunately this reply code is not known to the zcrypt error routines and thus default behavior is to switch the ap queue offline. This patch now makes the ap error routine aware of the reply code and so userspace is informed about the bad processing result but the queue is not switched to offline state any more. Signed-off-by: Harald Freudenberger <freude@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-01-31s390/smp: fix CPU hotplug deadlock with CPU rescanGerald Schaefer
commit b7cb707c373094ce4008d4a6ac9b6b366ec52da5 upstream. smp_rescan_cpus() is called without the device_hotplug_lock, which can lead to a dedlock when a new CPU is found and immediately set online by a udev rule. This was observed on an older kernel version, where the cpu_hotplug_begin() loop was still present, and it resulted in hanging chcpu and systemd-udev processes. This specific deadlock will not show on current kernels. However, there may be other possible deadlocks, and since smp_rescan_cpus() can still trigger a CPU hotplug operation, the device_hotplug_lock should be held. For reference, this was the deadlock with the old cpu_hotplug_begin() loop: chcpu (rescan) systemd-udevd echo 1 > /sys/../rescan -> smp_rescan_cpus() -> (*) get_online_cpus() (increases refcount) -> smp_add_present_cpu() (new CPU found) -> register_cpu() -> device_add() -> udev "add" event triggered -----------> udev rule sets CPU online -> echo 1 > /sys/.../online -> lock_device_hotplug_sysfs() (this is missing in rescan path) -> device_online() -> (**) device_lock(new CPU dev) -> cpu_up() -> cpu_hotplug_begin() (loops until refcount == 0) -> deadlock with (*) -> bus_probe_device() -> device_attach() -> device_lock(new CPU dev) -> deadlock with (**) Fix this by taking the device_hotplug_lock in the CPU rescan path. Cc: <stable@vger.kernel.org> Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-13scsi: zfcp: fix posting too many status read buffers leading to adapter shutdownSteffen Maier
commit 60a161b7e5b2a252ff0d4c622266a7d8da1120ce upstream. Suppose adapter (open) recovery is between opened QDIO queues and before (the end of) initial posting of status read buffers (SRBs). This time window can be seconds long due to FSF_PROT_HOST_CONNECTION_INITIALIZING causing by design looping with exponential increase sleeps in the function performing exchange config data during recovery [zfcp_erp_adapter_strat_fsf_xconf()]. Recovery triggered by local link up. Suppose an event occurs for which the FCP channel would send an unsolicited notification to zfcp by means of a previously posted SRB. We saw it with local cable pull (link down) in multi-initiator zoning with multiple NPIV-enabled subchannels of the same shared FCP channel. As soon as zfcp_erp_adapter_strategy_open_fsf() starts posting the initial status read buffers from within the adapter's ERP thread, the channel does send an unsolicited notification. Since v2.6.27 commit d26ab06ede83 ("[SCSI] zfcp: receiving an unsolicted status can lead to I/O stall"), zfcp_fsf_status_read_handler() schedules adapter->stat_work to re-fill the just consumed SRB from a work item. Now the ERP thread and the work item post SRBs in parallel. Both contexts call the helper function zfcp_status_read_refill(). The tracking of missing (to be posted / re-filled) SRBs is not thread-safe due to separate atomic_read() and atomic_dec(), in order to depend on posting success. Hence, both contexts can see atomic_read(&adapter->stat_miss) == 1. One of the two contexts posts one too many SRB. Zfcp gets QDIO_ERROR_SLSB_STATE on the output queue (trace tag "qdireq1") leading to zfcp_erp_adapter_shutdown() in zfcp_qdio_handler_error(). An obvious and seemingly clean fix would be to schedule stat_work from the ERP thread and wait for it to finish. This would serialize all SRB re-fills. However, we already have another work item wait on the ERP thread: adapter->scan_work runs zfcp_fc_scan_ports() which calls zfcp_fc_eval_gpn_ft(). The latter calls zfcp_erp_wait() to wait for all the open port recoveries during zfcp auto port scan, but in fact it waits for any pending recovery including an adapter recovery. This approach leads to a deadlock. [see also v3.19 commit 18f87a67e6d6 ("zfcp: auto port scan resiliency"); v2.6.37 commit d3e1088d6873 ("[SCSI] zfcp: No ERP escalation on gpn_ft eval"); v2.6.28 commit fca55b6fb587 ("[SCSI] zfcp: fix deadlock between wq triggered port scan and ERP") fixing v2.6.27 commit c57a39a45a76 ("[SCSI] zfcp: wait until adapter is finished with ERP during auto-port"); v2.6.27 commit cc8c282963bd ("[SCSI] zfcp: Automatically attach remote ports")] Instead make the accounting of missing SRBs atomic for parallel execution in both the ERP thread and adapter->stat_work. Signed-off-by: Steffen Maier <maier@linux.ibm.com> Fixes: d26ab06ede83 ("[SCSI] zfcp: receiving an unsolicted status can lead to I/O stall") Cc: <stable@vger.kernel.org> #2.6.27+ Reviewed-by: Jens Remus <jremus@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-13virtio/s390: fix race in ccw_io_helper()Halil Pasic
commit 78b1a52e05c9db11d293342e8d6d8a230a04b4e7 upstream. While ccw_io_helper() seems like intended to be exclusive in a sense that it is supposed to facilitate I/O for at most one thread at any given time, there is actually nothing ensuring that threads won't pile up at vcdev->wait_q. If they do, all threads get woken up and see the status that belongs to some other request than their own. This can lead to bugs. For an example see: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1788432 This race normally does not cause any problems. The operations provided by struct virtio_config_ops are usually invoked in a well defined sequence, normally don't fail, and are normally used quite infrequent too. Yet, if some of the these operations are directly triggered via sysfs attributes, like in the case described by the referenced bug, userspace is given an opportunity to force races by increasing the frequency of the given operations. Let us fix the problem by ensuring, that for each device, we finish processing the previous request before starting with a new one. Signed-off-by: Halil Pasic <pasic@linux.ibm.com> Reported-by: Colin Ian King <colin.king@canonical.com> Cc: stable@vger.kernel.org Message-Id: <20180925121309.58524-3-pasic@linux.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-13virtio/s390: avoid race on vcdev->configHalil Pasic
commit 2448a299ec416a80f699940a86f4a6d9a4f643b1 upstream. Currently we have a race on vcdev->config in virtio_ccw_get_config() and in virtio_ccw_set_config(). This normally does not cause problems, as these are usually infrequent operations. However, for some devices writing to/reading from the config space can be triggered through sysfs attributes. For these, userspace can force the race by increasing the frequency. Signed-off-by: Halil Pasic <pasic@linux.ibm.com> Cc: stable@vger.kernel.org Message-Id: <20180925121309.58524-2-pasic@linux.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-05s390/qeth: fix length check in SNMP processingJulian Wiedmann
[ Upstream commit 9a764c1e59684c0358e16ccaafd870629f2cfe67 ] The response for a SNMP request can consist of multiple parts, which the cmd callback stages into a kernel buffer until all parts have been received. If the callback detects that the staging buffer provides insufficient space, it bails out with error. This processing is buggy for the first part of the response - while it initially checks for a length of 'data_len', it later copies an additional amount of 'offsetof(struct qeth_snmp_cmd, data)' bytes. Fix the calculation of 'data_len' for the first part of the response. This also nicely cleans up the memcpy code. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-27s390/qeth: fix HiperSockets snifferJulian Wiedmann
[ Upstream commit bd74a7f9cc033cf4d405788f80292268987dc0c5 ] Sniffing mode for L3 HiperSockets requires that no IP addresses are registered with the HW. The preferred way to achieve this is for userspace to delete all the IPs on the interface. But qeth is expected to also tolerate a configuration where that is not the case, by skipping the IP registration when in sniffer mode. Since commit 5f78e29ceebf ("qeth: optimize IP handling in rx_mode callback") reworked the IP registration logic in the L3 subdriver, this no longer works. When the qeth device is set online, qeth_l3_recover_ip() now unconditionally registers all unicast addresses from our internal IP table. While we could fix this particular problem by skipping qeth_l3_recover_ip() on a sniffer device, the more future-proof change is to skip the IP address registration at the lowest level. This way we a) catch any future code path that attempts to register an IP address without considering the sniffer scenario, and b) continue to build up our internal IP table, so that if sniffer mode is switched off later we can operate just like normal. Fixes: 5f78e29ceebf ("qeth: optimize IP handling in rx_mode callback") Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2018-11-04s390/qeth: fix error handling in adapter command callbacksJulian Wiedmann
[ Upstream commit 686c97ee29c886ee07d17987d0059874c5c3b5af ] Make sure to check both return code fields before(!) processing the command response. Otherwise we risk operating on invalid data. This matches an earlier fix for SETASSPARMS commands, see commit ad3cbf613329 ("s390/qeth: fix error handling in checksum cmd callback"). Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2018-10-18s390/cio: Fix how vfio-ccw checks pinned pagesEric Farman
commit 24abf2901b18bf941b9f21ea2ce5791f61097ae4 upstream. We have two nested loops to check the entries within the pfn_array_table arrays. But we mistakenly use the outer array as an index in our check, and completely ignore the indexing performed by the inner loop. Cc: stable@vger.kernel.org Signed-off-by: Eric Farman <farman@linux.ibm.com> Message-Id: <20181002010235.42483-1-farman@linux.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-10s390/qeth: don't dump past end of unknown HW headerJulian Wiedmann
[ Upstream commit 0ac1487c4b2de383b91ecad1be561b8f7a2c15f4 ] For inbound data with an unsupported HW header format, only dump the actual HW header. We have no idea how much payload follows it, and what it contains. Worst case, we dump past the end of the Inbound Buffer and access whatever is located next in memory. Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-10s390/qeth: use vzalloc for QUERY OAT bufferWenjia Zhang
[ Upstream commit aec45e857c5538664edb76a60dd452e3265f37d1 ] qeth_query_oat_command() currently allocates the kernel buffer for the SIOC_QETH_QUERY_OAT ioctl with kzalloc. So on systems with fragmented memory, large allocations may fail (eg. the qethqoat tool by default uses 132KB). Solve this issue by using vzalloc, backing the allocation with non-contiguous memory. Signed-off-by: Wenjia Zhang <wenjia@linux.ibm.com> Reviewed-by: Julian Wiedmann <jwi@linux.ibm.com> Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-03s390/scm_blk: correct numa_node in scm_blk_dev_setupVasily Gorbik
[ Upstream commit d642d6262f4fcfa5d200ec6e218c17f0c15b3390 ] The numa_node field of the tag_set struct has to be explicitly initialized, otherwise it stays as 0, which is a valid numa node id and cause memory allocation failure if node 0 is offline. Acked-by: Sebastian Ott <sebott@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-03s390/dasd: correct numa_node in dasd_alloc_queueVasily Gorbik
[ Upstream commit b17e3abb0af404cb62ad4ef1a5962f58b06e2b78 ] The numa_node field of the tag_set struct has to be explicitly initialized, otherwise it stays as 0, which is a valid numa node id and cause memory allocation failure if node 0 is offline. Acked-by: Stefan Haberland <sth@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-26s390/qeth: reset layer2 attribute on layer switchJulian Wiedmann
[ Upstream commit 70551dc46ffa3555a0b5f3545b0cd87ab67fd002 ] After the subdriver's remove() routine has completed, the card's layer mode is undetermined again. Reflect this in the layer2 field. If qeth_dev_layer2_store() hits an error after remove() was called, the card _always_ requires a setup(), even if the previous layer mode is requested again. But qeth_dev_layer2_store() bails out early if the requested layer mode still matches the current one. So unless we reset the layer2 field, re-probing the card back to its previous mode is currently not possible. Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-26s390/qeth: fix race in used-buffer accountingJulian Wiedmann
[ Upstream commit a702349a4099cd5a7bab0904689d8e0bf8dcd622 ] By updating q->used_buffers only _after_ do_QDIO() has completed, there is a potential race against the buffer's TX completion. In the unlikely case that the TX completion path wins, qeth_qdio_output_handler() would decrement the counter before qeth_flush_buffers() even incremented it. Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-15s390/dasd: fix panic for failed online processingStefan Haberland
[ Upstream commit 7c6553d4db03350dad0110c3224194c19df76a8f ] Fix a panic that occurs for a device that got an error in dasd_eckd_check_characteristics() during online processing. For example the read configuration data command may have failed. If this error occurs the device is not being set online and the earlier invoked steps during online processing are rolled back. Therefore dasd_eckd_uncheck_device() is called which needs a valid private structure. But this pointer is not valid if dasd_eckd_check_characteristics() has failed. Check for a valid device->private pointer to prevent a panic. Reviewed-by: Jan Hoeppner <hoeppner@linux.ibm.com> Signed-off-by: Stefan Haberland <sth@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-15s390/dasd: fix hanging offline processing due to canceled workerStefan Haberland
[ Upstream commit 669f3765b755fd8739ab46ce3a9c6292ce8b3d2a ] During offline processing two worker threads are canceled without freeing the device reference which leads to a hanging offline process. Reviewed-by: Jan Hoeppner <hoeppner@linux.ibm.com> Signed-off-by: Stefan Haberland <sth@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-05s390/qdio: reset old sbal_state flagsJulian Wiedmann
commit 64e03ff72623b8c2ea89ca3cb660094e019ed4ae upstream. When allocating a new AOB fails, handle_outbound() is still capable of transmitting the selected buffer (just without async completion). But if a previous transfer on this queue slot used async completion, its sbal_state flags field is still set to QDIO_OUTBUF_STATE_FLAG_PENDING. So when the upper layer driver sees this stale flag, it expects an async completion that never happens. Fix this by unconditionally clearing the flags field. Fixes: 104ea556ee7f ("qdio: support asynchronous delivery of storage blocks") Cc: <stable@vger.kernel.org> #v3.2+ Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-24vfio: ccw: fix error return in vfio_ccw_sch_eventDong Jia Shi
[ Upstream commit 2c861d89ccda2fbcea9358eff9cc5f8fae548be5 ] If the device has not been registered, or there is work pending, we should reschedule a sch_event call again. Signed-off-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com> Message-Id: <20180502072559.50691-1-bjsdjshi@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-03scsi: zfcp: assert that the ERP lock is held when tracing a recovery triggerJens Remus
[ Upstream commit 9e156c54ace310ce7fb1cd960e62416947f3d47c ] Otherwise iterating with list_for_each() over the adapter->erp_ready_head and adapter->erp_running_head lists can lead to an infinite loop. See commit "zfcp: fix infinite iteration on erp_ready_head list". The run-time check is only performed for debug kernels which have the kernel lock validator enabled. Following is an example of the warning that is reported, if the ERP lock is not held when calling zfcp_dbf_rec_trig(): WARNING: CPU: 0 PID: 604 at drivers/s390/scsi/zfcp_dbf.c:288 zfcp_dbf_rec_trig+0x172/0x188 Modules linked in: ... CPU: 0 PID: 604 Comm: kworker/u128:3 Not tainted 4.16.0-... #1 Hardware name: IBM 2964 N96 702 (z/VM 6.4.0) Workqueue: zfcp_q_0.0.1906 zfcp_scsi_rport_work Krnl PSW : 00000000330fdbf9 00000000367e9728 (zfcp_dbf_rec_trig+0x172/0x188) R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:3 PM:0 RI:0 EA:3 Krnl GPRS: 00000000c57a5d99 3288200000000000 0000000000000000 000000006cc82740 00000000009d09d6 0000000000000000 00000000000000ff 0000000000000000 0000000000000000 0000000000e1b5fe 000000006de01d38 0000000076130958 000000006cc82548 000000006de01a98 00000000009d09d6 000000006a6d3c80 Krnl Code: 00000000009d0ad2: eb7ff0b80004 lmg %r7,%r15,184(%r15) 00000000009d0ad8: c0f4000d7dd0 brcl 15,b80678 #00000000009d0ade: a7f40001 brc 15,9d0ae0 >00000000009d0ae2: a7f4ff7d brc 15,9d09dc 00000000009d0ae6: e340f0f00004 lg %r4,240(%r15) 00000000009d0aec: eb7ff0b80004 lmg %r7,%r15,184(%r15) 00000000009d0af2: 07f4 bcr 15,%r4 00000000009d0af4: 0707 bcr 0,%r7 Call Trace: ([<00000000009d09d6>] zfcp_dbf_rec_trig+0x66/0x188) [<00000000009dd740>] zfcp_scsi_rport_work+0x98/0x190 [<0000000000169b34>] process_one_work+0x3d4/0x6f8 [<000000000016a08a>] worker_thread+0x232/0x418 [<000000000017219e>] kthread+0x166/0x178 [<0000000000b815ea>] kernel_thread_starter+0x6/0xc [<0000000000b815e4>] kernel_thread_starter+0x0/0xc 2 locks held by kworker/u128:3/604: #0: ((wq_completion)name){+.+.}, at: [<0000000082af1024>] process_one_work+0x1dc/0x6f8 #1: ((work_completion)(&port->rport_work)){+.+.}, at: [<0000000082af1024>] process_one_work+0x1dc/0x6f8 Last Breaking-Event-Address: [<00000000009d0ade>] zfcp_dbf_rec_trig+0x16e/0x188 ---[ end trace b2f4020572e2c124 ]--- Suggested-by: Steffen Maier <maier@linux.ibm.com> Signed-off-by: Jens Remus <jremus@linux.ibm.com> Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Reviewed-by: Steffen Maier <maier@linux.ibm.com> Signed-off-by: Steffen Maier <maier@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>