kernel/git/stable/linux-stable.git/drivers/s390, branch linux-6.10.y

s390/ap: Fix deadlock caused by recursive lock of the AP bus scan mutex

2024-10-04T14:32:56+00:00

[ Upstream commit 56199bb956c3ea82e39c72d2972ebf8c18c6a8c0 ] There is a possibility to deadlock with an recursive lock of the AP bus scan mutex ap_scan_bus_mutex: ... kernel: ============================================ ... kernel: WARNING: possible recursive locking detected ... kernel: 5.14.0-496.el9.s390x #3 Not tainted ... kernel: -------------------------------------------- ... kernel: kworker/12:1/130 is trying to acquire lock: ... kernel: 0000000358bc1510 (ap_scan_bus_mutex){+.+.}-{3:3}, at: ap_bus_force_rescan+0x92/0x108 ... kernel: but task is already holding lock: ... kernel: 0000000358bc1510 (ap_scan_bus_mutex){+.+.}-{3:3}, at: ap_scan_bus_wq_callback+0x28/0x60 ... kernel: other info that might help us debug this: ... kernel: Possible unsafe locking scenario: ... kernel: CPU0 ... kernel: ---- ... kernel: lock(ap_scan_bus_mutex); ... kernel: lock(ap_scan_bus_mutex); ... kernel: *** DEADLOCK *** Here is how the callstack looks like: ... [<00000003576fe9ce>] process_one_work+0x2a6/0x748 ... [<0000000358150c00>] ap_scan_bus_wq_callback+0x40/0x60 <- mutex locked ... [<00000003581506e2>] ap_scan_bus+0x5a/0x3b0 ... [<000000035815037c>] ap_scan_adapter+0x5b4/0x8c0 ... [<000000035814fa34>] ap_scan_domains+0x2d4/0x668 ... [<0000000357d989b4>] device_add+0x4a4/0x6b8 ... [<0000000357d9bb54>] bus_probe_device+0xb4/0xc8 ... [<0000000357d9daa8>] __device_attach+0x120/0x1b0 ... [<0000000357d9a632>] bus_for_each_drv+0x8a/0xd0 ... [<0000000357d9d548>] __device_attach_driver+0xc0/0x140 ... [<0000000357d9d3d8>] driver_probe_device+0x40/0xf0 ... [<0000000357d9cec2>] really_probe+0xd2/0x460 ... [<000000035814d7b0>] ap_device_probe+0x150/0x208 ... [<000003ff802a5c46>] zcrypt_cex4_queue_probe+0xb6/0x1c0 [zcrypt_cex4] ... [<000003ff7fb2d36e>] zcrypt_queue_register+0xe6/0x1b0 [zcrypt] ... [<000003ff7fb2c8ac>] zcrypt_rng_device_add+0x94/0xd8 [zcrypt] ... [<0000000357d7bc52>] hwrng_register+0x212/0x228 ... [<0000000357d7b8c2>] add_early_randomness+0x102/0x110 ... [<000003ff7fb29c94>] zcrypt_rng_data_read+0x94/0xb8 [zcrypt] ... [<0000000358150aca>] ap_bus_force_rescan+0x92/0x108 ... [<0000000358177572>] mutex_lock_interruptible_nested+0x32/0x40 <- lock again Note this only happens when the very first random data providing crypto card appears via hot plug in the system AND is in disabled state ("deconfig"). Then the initial pull of random data fails and a re-scan of the AP bus is triggered while already in the middle of an AP bus scan caused by the appearing new hardware. The fix is relatively simple once the scenario us understood: The AP bus force rescan function will immediately return if there is currently an AP bus scan running with the very same thread id. Fixes: eacf5b3651c5 ("s390/ap: introduce mutex to lock the AP bus scan") Signed-off-by: Harald Freudenberger Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik Signed-off-by: Sasha Levin

s390/ap: Refine AP bus bindings complete processing

2024-08-29T15:36:07+00:00

commit b4f5bd60d558f6ba451d7e76aa05782c07a182a3 upstream. With the rework of the AP bus scan and the introduction of a bindings complete completion also the timing until the userspace finally receives a AP bus binding complete uevent had increased. Unfortunately this event triggers some important jobs for preparation of KVM guests, for example the modification of card/queue masks to reassign AP resources to the alternate AP queue device driver (vfio_ap) which is the precondition for building mediated devices which may be a precondition for starting KVM guests using AP resources. This small fix now triggers the check for binding complete each time an AP device driver has registered. With this patch the bindings complete may be posted up to 30s earlier as there is no need to wait for the next AP bus scan any more. Fixes: 778412ab915d ("s390/ap: rearm APQNs bindings complete completion") Signed-off-by: Harald Freudenberger Reviewed-by: Holger Dengler Cc: stable@vger.kernel.org Acked-by: Alexander Gordeev Signed-off-by: Vasily Gorbik Signed-off-by: Greg Kroah-Hartman

s390/dasd: Remove DMA alignment

2024-08-29T15:35:52+00:00

[ Upstream commit 2a07bb64d80152701d507b1498237ed1b8d83866 ] This reverts commit bc792884b76f ("s390/dasd: Establish DMA alignment"). Quoting the original commit: linux-next commit bf8d08532bc1 ("iomap: add support for dma aligned direct-io") changes the alignment requirement to come from the block device rather than the block size, and the default alignment requirement is 512-byte boundaries. Since DASD I/O has page alignments for IDAW/TIDAW requests, let's override this value to restore the expected behavior. I mentioned TIDAW, but that was wrong. TIDAWs have no distinct alignment requirement (per p. 15-70 of POPS SA22-7832-13): Unless otherwise specified, TIDAWs may designate a block of main storage on any boundary and length up to 4K bytes, provided the specified block does not cross a 4 K-byte boundary. IDAWs do, but the original commit neglected that while ECKD DASD are typically formatted in 4096-byte blocks, they don't HAVE to be. Formatting an ECKD volume with smaller blocks is permitted (dasdfmt -b xxx), and the problematic commit enforces alignment properties to such a device that will result in errors, such as: [test@host ~]# lsdasd -l a367 | grep blksz blksz: 512 [test@host ~]# mkfs.xfs -f /dev/disk/by-path/ccw-0.0.a367-part1 meta-data=/dev/dasdc1 isize=512 agcount=4, agsize=230075 blks = sectsz=512 attr=2, projid32bit=1 = crc=1 finobt=1, sparse=1, rmapbt=1 = reflink=1 bigtime=1 inobtcount=1 nrext64=1 data = bsize=4096 blocks=920299, imaxpct=25 = sunit=0 swidth=0 blks naming =version 2 bsize=4096 ascii-ci=0, ftype=1 log =internal log bsize=4096 blocks=16384, version=2 = sectsz=512 sunit=0 blks, lazy-count=1 realtime =none extsz=4096 blocks=0, rtextents=0 error reading existing superblock: Invalid argument mkfs.xfs: pwrite failed: Invalid argument libxfs_bwrite: write failed on (unknown) bno 0x70565c/0x100, err=22 mkfs.xfs: Releasing dirty buffer to free list! found dirty buffer (bulk) on free list! mkfs.xfs: pwrite failed: Invalid argument ...snipped... The original commit omitted the FBA discipline for just this reason, but the formatted block size of the other disciplines was overlooked. The solution to all of this is to revert to the original behavior, such that the block size can be respected. There were two commits [1] that moved this code in the interim, so a straight git-revert is not possible, but the change is straightforward. But what of the original problem? That was manifested with a direct-io QEMU guest, where QEMU itself was changed a month or two later with commit 25474d90aa ("block: use the request length for iov alignment") such that the blamed kernel commit is unnecessary. [1] commit 0127a47f58c6 ("dasd: move queue setup to common code") commit fde07a4d74e3 ("dasd: use the atomic queue limits API") Fixes: bc792884b76f ("s390/dasd: Establish DMA alignment") Reviewed-by: Stefan Haberland Signed-off-by: Eric Farman Signed-off-by: Stefan Haberland Link: https://lore.kernel.org/r/20240812125733.126431-2-sth@linux.ibm.com Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

s390/dasd: fix error recovery leading to data corruption on ESE devices

2024-08-29T15:35:36+00:00

commit 7db4042336580dfd75cb5faa82c12cd51098c90b upstream. Extent Space Efficient (ESE) or thin provisioned volumes need to be formatted on demand during usual IO processing. The dasd_ese_needs_format function checks for error codes that signal the non existence of a proper track format. The check for incorrect length is to imprecise since other error cases leading to transport of insufficient data also have this flag set. This might lead to data corruption in certain error cases for example during a storage server warmstart. Fix by removing the check for incorrect length and replacing by explicitly checking for invalid track format in transport mode. Also remove the check for file protected since this is not a valid ESE handling case. Cc: stable@vger.kernel.org # 5.3+ Fixes: 5e2b17e712cf ("s390/dasd: Add dynamic formatting support for ESE volumes") Reviewed-by: Jan Hoeppner Signed-off-by: Stefan Haberland Link: https://lore.kernel.org/r/20240812125733.126431-3-sth@linux.ibm.com Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

s390/sclp: Prevent release of buffer in I/O

2024-08-14T13:34:16+00:00

[ Upstream commit bf365071ea92b9579d5a272679b74052a5643e35 ] When a task waiting for completion of a Store Data operation is interrupted, an attempt is made to halt this operation. If this attempt fails due to a hardware or firmware problem, there is a chance that the SCLP facility might store data into buffers referenced by the original operation at a later time. Handle this situation by not releasing the referenced data buffers if the halt attempt fails. For current use cases, this might result in a leak of few pages of memory in case of a rare hardware/firmware malfunction. Reviewed-by: Heiko Carstens Signed-off-by: Peter Oberparleiter Signed-off-by: Alexander Gordeev Signed-off-by: Sasha Levin

s390/dasd: fix error checks in dasd_copy_pair_store()

2024-08-03T07:00:26+00:00

[ Upstream commit 8e64d2356cbc800b4cd0e3e614797f76bcf0cdb8 ] dasd_add_busid() can return an error via ERR_PTR() if an allocation fails. However, two callsites in dasd_copy_pair_store() do not check the result, potentially resulting in a NULL pointer dereference. Fix this by checking the result with IS_ERR() and returning the error up the stack. Fixes: a91ff09d39f9b ("s390/dasd: add copy pair setup") Signed-off-by: Carlos López Signed-off-by: Stefan Haberland Link: https://lore.kernel.org/r/20240715112434.2111291-3-sth@linux.ibm.com Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

s390/dasd: Fix invalid dereferencing of indirect CCW data pointer

2024-07-03T14:27:06+00:00

Fix invalid dereferencing of indirect CCW data pointer in dasd_eckd_dump_sense() that leads to a kernel panic in error cases. When using indirect addressing for DASD CCWs (IDAW) the CCW CDA pointer does not contain the data address itself but a pointer to the IDAL. This needs to be translated from physical to virtual as well before using it. This dereferencing is also used for dasd_page_cache and also fixed although it is very unlikely that this code path ever gets used. Fixes: c0bd39601c13 ("s390/dasd: use new address translation helpers") Cc: stable@vger.kernel.org Signed-off-by: Stefan Haberland Reviewed-by: Heiko Carstens Signed-off-by: Heiko Carstens

s390/vfio_ccw: Fix target addresses of TIC CCWs

2024-07-03T10:05:32+00:00

The processing of a Transfer-In-Channel (TIC) CCW requires locating the target of the CCW in the channel program, and updating the address to reflect what will actually be sent to hardware. An error exists where the 64-bit virtual address is truncated to 32-bits (variable "cda") when performing this math. Since s390 addresses of that size are 31-bits, this leaves that additional bit enabled such that the resulting I/O triggers a channel program check. This shows up occasionally when booting a KVM guest from a passthrough DASD device: ..snip... Interrupt Response Block Data: : 0x0000000000003990 Function Ctrl : [Start] Activity Ctrl : Status Ctrl : [Alert] [Primary] [Secondary] [Status-Pending] Device Status : Channel Status : [Program-Check] cpa=: 0x00000000008d0018 prev_ccw=: 0x0000000000000000 this_ccw=: 0x0000000000000000 ...snip... dasd-ipl: Failed to run IPL1 channel program The channel program address of "0x008d0018" in the IRB doesn't look wrong, but tracing the CCWs shows the offending bit enabled: ccw=0x0000012e808d0000 cda=00a0b030 ccw=0x0000012e808d0008 cda=00a0b038 ccw=0x0000012e808d0010 cda=808d0008 ccw=0x0000012e808d0018 cda=00a0b040 Fix the calculation of the TIC CCW's data address such that it points to a valid 31-bit address regardless of the input address. Fixes: bd36cfbbb9e1 ("s390/vfio_ccw_cp: use new address translation helpers") Signed-off-by: Eric Farman Reviewed-by: Heiko Carstens Link: https://lore.kernel.org/r/20240628163738.3643513-1-farman@linux.ibm.com Signed-off-by: Alexander Gordeev Signed-off-by: Heiko Carstens

s390/sclp: Fix sclp_init() cleanup on failure

2024-06-24T09:07:06+00:00

If sclp_init() fails it only partially cleans up: if there are multiple failing calls to sclp_init() sclp_state_change_event will be added several times to sclp_reg_list, which results in the following warning: ------------[ cut here ]------------ list_add double add: new=000003ffe1598c10, prev=000003ffe1598bf0, next=000003ffe1598c10. WARNING: CPU: 0 PID: 1 at lib/list_debug.c:35 __list_add_valid_or_report+0xde/0xf8 CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.10.0-rc3 Krnl PSW : 0404c00180000000 000003ffe0d6076a (__list_add_valid_or_report+0xe2/0xf8) R:0 T:1 IO:0 EX:0 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 RI:0 EA:3 ... Call Trace: [<000003ffe0d6076a>] __list_add_valid_or_report+0xe2/0xf8 ([<000003ffe0d60766>] __list_add_valid_or_report+0xde/0xf8) [<000003ffe0a8d37e>] sclp_init+0x40e/0x450 [<000003ffe00009f2>] do_one_initcall+0x42/0x1e0 [<000003ffe15b77a6>] do_initcalls+0x126/0x150 [<000003ffe15b7a0a>] kernel_init_freeable+0x1ba/0x1f8 [<000003ffe0d6650e>] kernel_init+0x2e/0x180 [<000003ffe000301c>] __ret_from_fork+0x3c/0x60 [<000003ffe0d759ca>] ret_from_fork+0xa/0x30 Fix this by removing sclp_state_change_event from sclp_reg_list when sclp_init() fails. Reviewed-by: Peter Oberparleiter Signed-off-by: Heiko Carstens Signed-off-by: Alexander Gordeev

s390/virtio_ccw: Fix config change notifications

2024-06-17T19:49:01+00:00

Commit e3e9bda38e6d ("s390/virtio_ccw: use DMA handle from DMA API") broke configuration change notifications for virtio-ccw by putting the DMA address of *indicatorp directly into ccw->cda disregarding the fact that if !!(vcdev->is_thinint) then the function virtio_ccw_register_adapter_ind() will overwrite that ccw->cda value with the address of the virtio_thinint_area so it can actually set up the adapter interrupts via CCW_CMD_SET_IND_ADAPTER. Thus we end up pointing to the wrong object for both CCW_CMD_SET_IND if setting up the adapter interrupts fails, and for CCW_CMD_SET_CONF_IND regardless whether it succeeds or fails. To fix this, let us save away the dma address of *indicatorp in a local variable, and copy it to ccw->cda after the "vcdev->is_thinint" branch. Fixes: e3e9bda38e6d ("s390/virtio_ccw: use DMA handle from DMA API") Reported-by: Boqiao Fu Reported-by: Sebastian Mitterle Closes: https://issues.redhat.com/browse/RHEL-39983 Tested-by: Thomas Huth Reviewed-by: Eric Farman Signed-off-by: Halil Pasic Link: https://lore.kernel.org/r/20240611214716.1002781-1-pasic@linux.ibm.com Signed-off-by: Vasily Gorbik