Commit graph

20 commits

Author SHA1 Message Date
Ksawlii
8cfff74683 Revert "s390/zcore: no need to check return value of debugfs_create functions"
This reverts commit 638d4f23f7.
2024-11-24 00:22:59 +01:00
Ksawlii
0d62b35c45 Revert "s390/zcore: release dump save area on restart or power down"
This reverts commit ebda96b59a.
2024-11-24 00:22:59 +01:00
Ksawlii
f3da6367d0 Revert "s390/sclp_vt220: Convert newlines to CRLF instead of LFCR"
This reverts commit 253e51ed4b.
2024-11-24 00:22:52 +01:00
Thomas Weißschuh
253e51ed4b s390/sclp_vt220: Convert newlines to CRLF instead of LFCR
commit dee3df68ab4b00fff6bdf9fc39541729af37307c upstream.

According to the VT220 specification the possible character combinations
sent on RETURN are only CR or CRLF [0].

	The Return key sends either a CR character (0/13) or a CR
	character (0/13) and an LF character (0/10), depending on the
	set/reset state of line feed/new line mode (LNM).

The sclp/vt220 driver however uses LFCR. This can confuse tools, for
example the kunit runner.

Link: https://vt100.net/docs/vt220-rm/chapter3.html#S3.2
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Link: https://lore.kernel.org/r/20241014-s390-kunit-v1-2-941defa765a6@linutronix.de
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-23 23:21:55 +01:00
Alexander Egorenkov
ebda96b59a s390/zcore: release dump save area on restart or power down
[ Upstream commit dabdfac0e85c8c1e811b10c08742f49285e78a17 ]

The zFCP/NVMe standalone dumper is supposed to release the dump save area
resource as soon as possible but might fail to do so, for instance, if it
crashes. To avoid this situation, register a reboot notifier and ensure
the dump save area resource is released on reboot or power down.

Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Stable-dep-of: 0b18c852cc6f ("tracing: Have saved_cmdlines arrays all in one allocation")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-23 23:21:48 +01:00
Alexander Egorenkov
638d4f23f7 s390/zcore: no need to check return value of debugfs_create functions
[ Upstream commit 7449ca87312a5b0390b765be65a126e6e5451026 ]

When calling debugfs functions, there is no need to ever check the
return value.  The function can work or not, but the code logic should
never do something different based on this.

See commit 7dd541a3fb34 ("s390: no need to check return value of debugfs_create functions").

Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Stable-dep-of: 0b18c852cc6f ("tracing: Have saved_cmdlines arrays all in one allocation")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-23 23:21:48 +01:00
Alexander Lobakin
22a80d4a48 s390/cio: rename bitmap_size() -> idset_bitmap_size()
commit c1023f5634b9bfcbfff0dc200245309e3cde9b54 upstream.

bitmap_size() is a pretty generic name and one may want to use it for
a generic bitmap API function. At the same time, its logic is not
"generic", i.e. it's not just `nbits -> size of bitmap in bytes`
converter as it would be expected from its name.
Add the prefix 'idset_' used throughout the file where the function
resides.

Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Acked-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-23 23:20:43 +01:00
Alexander Lobakin
7dca11aa19 bitmap: introduce generic optimized bitmap_size()
commit a37fbe666c016fd89e4460d0ebfcea05baba46dc upstream.

The number of times yet another open coded
`BITS_TO_LONGS(nbits) * sizeof(long)` can be spotted is huge.
Some generic helper is long overdue.

Add one, bitmap_size(), but with one detail.
BITS_TO_LONGS() uses DIV_ROUND_UP(). The latter works well when both
divident and divisor are compile-time constants or when the divisor
is not a pow-of-2. When it is however, the compilers sometimes tend
to generate suboptimal code (GCC 13):

48 83 c0 3f          	add    $0x3f,%rax
48 c1 e8 06          	shr    $0x6,%rax
48 8d 14 c5 00 00 00 00	lea    0x0(,%rax,8),%rdx

%BITS_PER_LONG is always a pow-2 (either 32 or 64), but GCC still does
full division of `nbits + 63` by it and then multiplication by 8.
Instead of BITS_TO_LONGS(), use ALIGN() and then divide by 8. GCC:

8d 50 3f             	lea    0x3f(%rax),%edx
c1 ea 03             	shr    $0x3,%edx
81 e2 f8 ff ff 1f    	and    $0x1ffffff8,%edx

Now it shifts `nbits + 63` by 3 positions (IOW performs fast division
by 8) and then masks bits[2:0]. bloat-o-meter:

add/remove: 0/0 grow/shrink: 20/133 up/down: 156/-773 (-617)

Clang does it better and generates the same code before/after starting
from -O1, except that with the ALIGN() approach it uses %edx and thus
still saves some bytes:

add/remove: 0/0 grow/shrink: 9/133 up/down: 18/-538 (-520)

Note that we can't expand DIV_ROUND_UP() by adding a check and using
this approach there, as it's used in array declarations where
expressions are not allowed.
Add this helper to tools/ as well.

Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Acked-by: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-23 23:20:42 +01:00
Stefan Haberland
c1285d4ad5 s390/dasd: fix error recovery leading to data corruption on ESE devices
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 <hoeppner@linux.ibm.com>
Signed-off-by: Stefan Haberland <sth@linux.ibm.com>
Link: https://lore.kernel.org/r/20240812125733.126431-3-sth@linux.ibm.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-23 23:20:42 +01:00
Peter Oberparleiter
2dc2b91249 s390/sclp: Prevent release of buffer in I/O
[ 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 <hca@linux.ibm.com>
Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-23 23:20:24 +01:00
Heiko Carstens
7d4137cfae s390/sclp: Fix sclp_init() cleanup on failure
[ Upstream commit 6434b33faaa063df500af355ee6c3942e0f8d982 ]

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 <oberpar@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 14:19:48 +01:00
Holger Dengler
0fae7eaf09 s390/pkey: Wipe sensitive data on failure
[ Upstream commit 1d8c270de5eb74245d72325d285894a577a945d9 ]

Wipe sensitive data from stack also if the copy_to_user() fails.

Suggested-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Ingo Franzki <ifranzki@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 14:19:41 +01:00
Harald Freudenberger
f7013c9d5a s390/ap: Fix crash in AP internal function modify_bitmap()
commit d4f9d5a99a3fd1b1c691b7a1a6f8f3f25f4116c9 upstream.

A system crash like this

  Failing address: 200000cb7df6f000 TEID: 200000cb7df6f403
  Fault in home space mode while using kernel ASCE.
  AS:00000002d71bc007 R3:00000003fe5b8007 S:000000011a446000 P:000000015660c13d
  Oops: 0038 ilc:3 [#1] PREEMPT SMP
  Modules linked in: mlx5_ib ...
  CPU: 8 PID: 7556 Comm: bash Not tainted 6.9.0-rc7 #8
  Hardware name: IBM 3931 A01 704 (LPAR)
  Krnl PSW : 0704e00180000000 0000014b75e7b606 (ap_parse_bitmap_str+0x10e/0x1f8)
  R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:2 PM:0 RI:0 EA:3
  Krnl GPRS: 0000000000000001 ffffffffffffffc0 0000000000000001 00000048f96b75d3
  000000cb00000100 ffffffffffffffff ffffffffffffffff 000000cb7df6fce0
  000000cb7df6fce0 00000000ffffffff 000000000000002b 00000048ffffffff
  000003ff9b2dbc80 200000cb7df6fcd8 0000014bffffffc0 000000cb7df6fbc8
  Krnl Code: 0000014b75e7b5fc: a7840047            brc     8,0000014b75e7b68a
  0000014b75e7b600: 18b2                lr      %r11,%r2
  #0000014b75e7b602: a7f4000a            brc     15,0000014b75e7b616
  >0000014b75e7b606: eb22d00000e6        laog    %r2,%r2,0(%r13)
  0000014b75e7b60c: a7680001            lhi     %r6,1
  0000014b75e7b610: 187b                lr      %r7,%r11
  0000014b75e7b612: 84960021            brxh    %r9,%r6,0000014b75e7b654
  0000014b75e7b616: 18e9                lr      %r14,%r9
  Call Trace:
  [<0000014b75e7b606>] ap_parse_bitmap_str+0x10e/0x1f8
  ([<0000014b75e7b5dc>] ap_parse_bitmap_str+0xe4/0x1f8)
  [<0000014b75e7b758>] apmask_store+0x68/0x140
  [<0000014b75679196>] kernfs_fop_write_iter+0x14e/0x1e8
  [<0000014b75598524>] vfs_write+0x1b4/0x448
  [<0000014b7559894c>] ksys_write+0x74/0x100
  [<0000014b7618a440>] __do_syscall+0x268/0x328
  [<0000014b761a3558>] system_call+0x70/0x98
  INFO: lockdep is turned off.
  Last Breaking-Event-Address:
  [<0000014b75e7b636>] ap_parse_bitmap_str+0x13e/0x1f8
  Kernel panic - not syncing: Fatal exception: panic_on_oops

occured when /sys/bus/ap/a[pq]mask was updated with a relative mask value
(like +0x10-0x12,+60,-90) with one of the numeric values exceeding INT_MAX.

The fix is simple: use unsigned long values for the internal variables. The
correct checks are already in place in the function but a simple int for
the internal variables was used with the possibility to overflow.

Reported-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Tested-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-19 12:27:19 +01:00
Peter Oberparleiter
59a6ff0efa s390/cio: fix tracepoint subchannel type field
[ Upstream commit 8692a24d0fae19f674d51726d179ad04ba95d958 ]

The subchannel-type field "st" of s390_cio_stsch and s390_cio_msch
tracepoints is incorrectly filled with the subchannel-enabled SCHIB
value "ena". Fix this by assigning the correct value.

Fixes: d1de8633d96a ("s390 cio: Rewrite trace point class s390_class_schib")
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 12:26:52 +01:00
Harald Freudenberger
f936a4f1f5 s390/zcrypt: fix reference counting on zcrypt card objects
[ Upstream commit 50ed48c80fecbe17218afed4f8bed005c802976c ]

Tests with hot-plugging crytpo cards on KVM guests with debug
kernel build revealed an use after free for the load field of
the struct zcrypt_card. The reason was an incorrect reference
handling of the zcrypt card object which could lead to a free
of the zcrypt card object while it was still in use.

This is an example of the slab message:

    kernel: 0x00000000885a7512-0x00000000885a7513 @offset=1298. First byte 0x68 instead of 0x6b
    kernel: Allocated in zcrypt_card_alloc+0x36/0x70 [zcrypt] age=18046 cpu=3 pid=43
    kernel:  kmalloc_trace+0x3f2/0x470
    kernel:  zcrypt_card_alloc+0x36/0x70 [zcrypt]
    kernel:  zcrypt_cex4_card_probe+0x26/0x380 [zcrypt_cex4]
    kernel:  ap_device_probe+0x15c/0x290
    kernel:  really_probe+0xd2/0x468
    kernel:  driver_probe_device+0x40/0xf0
    kernel:  __device_attach_driver+0xc0/0x140
    kernel:  bus_for_each_drv+0x8c/0xd0
    kernel:  __device_attach+0x114/0x198
    kernel:  bus_probe_device+0xb4/0xc8
    kernel:  device_add+0x4d2/0x6e0
    kernel:  ap_scan_adapter+0x3d0/0x7c0
    kernel:  ap_scan_bus+0x5a/0x3b0
    kernel:  ap_scan_bus_wq_callback+0x40/0x60
    kernel:  process_one_work+0x26e/0x620
    kernel:  worker_thread+0x21c/0x440
    kernel: Freed in zcrypt_card_put+0x54/0x80 [zcrypt] age=9024 cpu=3 pid=43
    kernel:  kfree+0x37e/0x418
    kernel:  zcrypt_card_put+0x54/0x80 [zcrypt]
    kernel:  ap_device_remove+0x4c/0xe0
    kernel:  device_release_driver_internal+0x1c4/0x270
    kernel:  bus_remove_device+0x100/0x188
    kernel:  device_del+0x164/0x3c0
    kernel:  device_unregister+0x30/0x90
    kernel:  ap_scan_adapter+0xc8/0x7c0
    kernel:  ap_scan_bus+0x5a/0x3b0
    kernel:  ap_scan_bus_wq_callback+0x40/0x60
    kernel:  process_one_work+0x26e/0x620
    kernel:  worker_thread+0x21c/0x440
    kernel:  kthread+0x150/0x168
    kernel:  __ret_from_fork+0x3c/0x58
    kernel:  ret_from_fork+0xa/0x30
    kernel: Slab 0x00000372022169c0 objects=20 used=18 fp=0x00000000885a7c88 flags=0x3ffff00000000a00(workingset|slab|node=0|zone=1|lastcpupid=0x1ffff)
    kernel: Object 0x00000000885a74b8 @offset=1208 fp=0x00000000885a7c88
    kernel: Redzone  00000000885a74b0: bb bb bb bb bb bb bb bb                          ........
    kernel: Object   00000000885a74b8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
    kernel: Object   00000000885a74c8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
    kernel: Object   00000000885a74d8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
    kernel: Object   00000000885a74e8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
    kernel: Object   00000000885a74f8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
    kernel: Object   00000000885a7508: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 68 4b 6b 6b 6b a5  kkkkkkkkkkhKkkk.
    kernel: Redzone  00000000885a7518: bb bb bb bb bb bb bb bb                          ........
    kernel: Padding  00000000885a756c: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a              ZZZZZZZZZZZZ
    kernel: CPU: 0 PID: 387 Comm: systemd-udevd Not tainted 6.8.0-HF #2
    kernel: Hardware name: IBM 3931 A01 704 (KVM/Linux)
    kernel: Call Trace:
    kernel:  [<00000000ca5ab5b8>] dump_stack_lvl+0x90/0x120
    kernel:  [<00000000c99d78bc>] check_bytes_and_report+0x114/0x140
    kernel:  [<00000000c99d53cc>] check_object+0x334/0x3f8
    kernel:  [<00000000c99d820c>] alloc_debug_processing+0xc4/0x1f8
    kernel:  [<00000000c99d852e>] get_partial_node.part.0+0x1ee/0x3e0
    kernel:  [<00000000c99d94ec>] ___slab_alloc+0xaf4/0x13c8
    kernel:  [<00000000c99d9e38>] __slab_alloc.constprop.0+0x78/0xb8
    kernel:  [<00000000c99dc8dc>] __kmalloc+0x434/0x590
    kernel:  [<00000000c9b4c0ce>] ext4_htree_store_dirent+0x4e/0x1c0
    kernel:  [<00000000c9b908a2>] htree_dirblock_to_tree+0x17a/0x3f0
    kernel:  [<00000000c9b919dc>] ext4_htree_fill_tree+0x134/0x400
    kernel:  [<00000000c9b4b3d0>] ext4_dx_readdir+0x160/0x2f0
    kernel:  [<00000000c9b4bedc>] ext4_readdir+0x5f4/0x760
    kernel:  [<00000000c9a7efc4>] iterate_dir+0xb4/0x280
    kernel:  [<00000000c9a7f1ea>] __do_sys_getdents64+0x5a/0x120
    kernel:  [<00000000ca5d6946>] __do_syscall+0x256/0x310
    kernel:  [<00000000ca5eea10>] system_call+0x70/0x98
    kernel: INFO: lockdep is turned off.
    kernel: FIX kmalloc-96: Restoring Poison 0x00000000885a7512-0x00000000885a7513=0x6b
    kernel: FIX kmalloc-96: Marking all objects used

The fix is simple: Before use of the queue not only the queue object
but also the card object needs to increase it's reference count
with a call to zcrypt_card_get(). Similar after use of the queue
not only the queue but also the card object's reference count is
decreased with zcrypt_card_put().

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 09:22:35 +01:00
Peter Oberparleiter
e648baf242 s390/cio: fix invalid -EBUSY on ccw_device_start
commit 5ef1dc40ffa6a6cb968b0fdc43c3a61727a9e950 upstream.

The s390 common I/O layer (CIO) returns an unexpected -EBUSY return code
when drivers try to start I/O while a path-verification (PV) process is
pending. This can lead to failed device initialization attempts with
symptoms like broken network connectivity after boot.

Fix this by replacing the -EBUSY return code with a deferred condition
code 1 reply to make path-verification handling consistent from a
driver's point of view.

The problem can be reproduced semi-regularly using the following process,
while repeating steps 2-3 as necessary (example assumes an OSA device
with bus-IDs 0.0.a000-0.0.a002 on CHPID 0.02):

1. echo 0.0.a000,0.0.a001,0.0.a002 >/sys/bus/ccwgroup/drivers/qeth/group
2. echo 0 > /sys/bus/ccwgroup/devices/0.0.a000/online
3. echo 1 > /sys/bus/ccwgroup/devices/0.0.a000/online ; \
   echo on > /sys/devices/css0/chp0.02/status

Background information:

The common I/O layer starts path-verification I/Os when it receives
indications about changes in a device path's availability. This occurs
for example when hardware events indicate a change in channel-path
status, or when a manual operation such as a CHPID vary or configure
operation is performed.

If a driver attempts to start I/O while a PV is running, CIO reports a
successful I/O start (ccw_device_start() return code 0). Then, after
completion of PV, CIO synthesizes an interrupt response that indicates
an asynchronous status condition that prevented the start of the I/O
(deferred condition code 1).

If a PV indication arrives while a device is busy with driver-owned I/O,
PV is delayed until after I/O completion was reported to the driver's
interrupt handler. To ensure that PV can be started eventually, CIO
reports a device busy condition (ccw_device_start() return code -EBUSY)
if a driver tries to start another I/O while PV is pending.

In some cases this -EBUSY return code causes device drivers to consider
a device not operational, resulting in failed device initialization.

Note: The code that introduced the problem was added in 2003. Symptoms
started appearing with the following CIO commit that causes a PV
indication when a device is removed from the cio_ignore list after the
associated parent subchannel device was probed, but before online
processing of the CCW device has started:

2297791c92d0 ("s390/cio: dont unregister subchannel from child-drivers")

During boot, the cio_ignore list is modified by the cio_ignore dracut
module [1] as well as Linux vendor-specific systemd service scripts[2].
When combined, this commit and boot scripts cause a frequent occurrence
of the problem during boot.

[1] https://github.com/dracutdevs/dracut/tree/master/modules.d/81cio_ignore
[2] https://github.com/SUSE/s390-tools/blob/master/cio_ignore.service

Cc: stable@vger.kernel.org # v5.15+
Fixes: 2297791c92d0 ("s390/cio: dont unregister subchannel from child-drivers")
Tested-By: Thorsten Winkler <twinkler@linux.ibm.com>
Reviewed-by: Thorsten Winkler <twinkler@linux.ibm.com>
Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-18 22:25:37 +01:00
Alexandra Winter
7fe7c36a9b s390/qeth: Fix potential loss of L3-IP@ in case of network issues
commit 2fe8a236436fe40d8d26a1af8d150fc80f04ee1a upstream.

Symptom:
In case of a bad cable connection (e.g. dirty optics) a fast sequence of
network DOWN-UP-DOWN-UP could happen. UP triggers recovery of the qeth
interface. In case of a second DOWN while recovery is still ongoing, it
can happen that the IP@ of a Layer3 qeth interface is lost and will not
be recovered by the second UP.

Problem:
When registration of IP addresses with Layer 3 qeth devices fails, (e.g.
because of bad address format) the respective IP address is deleted from
its hash-table in the driver. If registration fails because of a ENETDOWN
condition, the address should stay in the hashtable, so a subsequent
recovery can restore it.

3caa4af834df ("qeth: keep ip-address after LAN_OFFLINE failure")
fixes this for registration failures during normal operation, but not
during recovery.

Solution:
Keep L3-IP address in case of ENETDOWN in qeth_l3_recover_ip(). For
consistency with qeth_l3_add_ip() we also keep it in case of EADDRINUSE,
i.e. for some reason the card already/still has this address registered.

Fixes: 4a71df50047f ("qeth: new qeth device driver")
Cc: stable@vger.kernel.org
Signed-off-by: Alexandra Winter <wintera@linux.ibm.com>
Link: https://lore.kernel.org/r/20240206085849.2902775-1-wintera@linux.ibm.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-18 12:13:33 +01:00
Vineeth Vijayan
13ea1b152b s390/scm: fix virtual vs physical address confusion
[ Upstream commit b1a6a1a77f0666a5a6dc0893ab6ec8fcae46f24c ]

Fix virtual vs physical address confusion (which currently are the same).

Signed-off-by: Vineeth Vijayan <vneethv@linux.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-18 12:12:16 +01:00
Jan Höppner
71394ac071 s390/dasd: protect device queue against concurrent access
commit db46cd1e0426f52999d50fa72cfa97fa39952885 upstream.

In dasd_profile_start() the amount of requests on the device queue are
counted. The access to the device queue is unprotected against
concurrent access. With a lot of parallel I/O, especially with alias
devices enabled, the device queue can change while dasd_profile_start()
is accessing the queue. In the worst case this leads to a kernel panic
due to incorrect pointer accesses.

Fix this by taking the device lock before accessing the queue and
counting the requests. Additionally the check for a valid profile data
pointer can be done earlier to avoid unnecessary locking in a hot path.

Cc:  <stable@vger.kernel.org>
Fixes: 4fa52aa7a82f ("[S390] dasd: add enhanced DASD statistics interface")
Reviewed-by: Stefan Haberland <sth@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Signed-off-by: Stefan Haberland <sth@linux.ibm.com>
Link: https://lore.kernel.org/r/20231025132437.1223363-3-sth@linux.ibm.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-18 12:10:57 +01:00
Gabriel2392
7ed7ee9edf Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00