tjh.dev
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1443962
3
927
Clone this repository
https://tangled.org/tjh.dev/kernel
https://tangled.org/did:plc:65gha4t3avpfpzmvpbwovss7/kernel
git@gordian.tjh.dev:tjh.dev/kernel
git@gordian.tjh.dev:did:plc:65gha4t3avpfpzmvpbwovss7/kernel
For self-hosted knots, clone URLs may differ based on your setup.
Download tar.gz
UFS runtime suspend can be triggered after pm_runtime_enable() is invoked
in ufshcd_pltfrm_init(). However if the first runtime suspend is triggered
before binding ufs_hba structure to ufs device structure via
platform_set_drvdata(), then UFS runtime suspend will be no longer
triggered in the future because its dev->power.runtime_error was set in the
first triggering and does not have any chance to be cleared.
To be more clear, dev->power.runtime_error is set if hba is NULL in
ufshcd_runtime_suspend() which returns -EINVAL to rpm_callback() where
dev->power.runtime_error is set as -EINVAL. In this case, any future
rpm_suspend() for UFS device fails because rpm_check_suspend_allowed()
fails due to non-zero
dev->power.runtime_error.
To resolve this issue, make sure the first UFS runtime suspend get valid
"hba" in ufshcd_runtime_suspend(): Enable UFS runtime PM only after hba is
successfully bound to UFS device structure.
Fixes: 62694735ca95 ([SCSI] ufs: Add runtime PM support for UFS host controller driver)
Cc: stable@vger.kernel.org
Signed-off-by: Stanley Chu <stanley.chu@mediatek.com>
Reviewed-by: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Update qedi driver version to 8.37.0.20
Signed-off-by: Nilesh Javali <njavali@marvell.com>
Reviewed-by: Lee Duncan <lduncan@suse.com>
Reviewed-by: Chris Leech <cleech@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
The kernel panic was observed during iSCSI discovery via offload with below
call trace,
[ 2115.646901] BUG: unable to handle kernel NULL pointer dereference at (null)
[ 2115.646909] IP: [<ffffffffacf7f0cc>] strncmp+0xc/0x60
[ 2115.646927] PGD 0
[ 2115.646932] Oops: 0000 [#1] SMP
[ 2115.647107] CPU: 24 PID: 264 Comm: kworker/24:1 Kdump: loaded Tainted: G
OE ------------ 3.10.0-957.el7.x86_64 #1
[ 2115.647133] Workqueue: slowpath-13:00. qed_slowpath_task [qed]
[ 2115.647135] task: ffff8d66af80b0c0 ti: ffff8d66afb80000 task.ti: ffff8d66afb80000
[ 2115.647136] RIP: 0010:[<ffffffffacf7f0cc>] [<ffffffffacf7f0cc>] strncmp+0xc/0x60
[ 2115.647141] RSP: 0018:ffff8d66afb83c68 EFLAGS: 00010206
[ 2115.647143] RAX: 0000000000000001 RBX: 0000000000000007 RCX: 000000000000000a
[ 2115.647144] RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffff8d632b3ba040
[ 2115.647145] RBP: ffff8d66afb83c68 R08: 0000000000000000 R09: 000000000000ffff
[ 2115.647147] R10: 0000000000000007 R11: 0000000000000800 R12: ffff8d66a30007a0
[ 2115.647148] R13: ffff8d66747a3c10 R14: ffff8d632b3ba000 R15: ffff8d66747a32f8
[ 2115.647149] FS: 0000000000000000(0000) GS:ffff8d66aff00000(0000) knlGS:0000000000000000
[ 2115.647151] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 2115.647152] CR2: 0000000000000000 CR3: 0000000509610000 CR4: 00000000007607e0
[ 2115.647153] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 2115.647154] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 2115.647155] PKRU: 00000000
[ 2115.647157] Call Trace:
[ 2115.647165] [<ffffffffc0634cc5>] qedi_get_protocol_tlv_data+0x2c5/0x510 [qedi]
[ 2115.647184] [<ffffffffc05968f5>] ? qed_mfw_process_tlv_req+0x245/0xbe0 [qed]
[ 2115.647195] [<ffffffffc05496cb>] qed_mfw_fill_tlv_data+0x4b/0xb0 [qed]
[ 2115.647206] [<ffffffffc0596911>] qed_mfw_process_tlv_req+0x261/0xbe0 [qed]
[ 2115.647215] [<ffffffffacce0e8e>] ? dequeue_task_fair+0x41e/0x660
[ 2115.647221] [<ffffffffacc2a59e>] ? __switch_to+0xce/0x580
[ 2115.647230] [<ffffffffc0546013>] qed_slowpath_task+0xa3/0x160 [qed]
[ 2115.647278] RIP [<ffffffffacf7f0cc>] strncmp+0xc/0x60
Fix kernel panic by validating the session targetname before providing TLV
data and confirming the presence of boot targets.
Signed-off-by: Nilesh Javali <njavali@marvell.com>
Reviewed-by: Lee Duncan <lduncan@suse.com>
Reviewed-by: Chris Leech <cleech@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
- set ioaccel2_sg_element member 'chain_indicator' to IOACCEL2_LAST_SG for
the last s/g element.
- set ioaccel2_sg_element member 'chain_indicator' to IOACCEL2_CHAIN when
chaining.
Reviewed-by: Bader Ali - Saleh <bader.alisaleh@microsemi.com>
Reviewed-by: Scott Teel <scott.teel@microsemi.com>
Reviewed-by: Matt Perricone <matt.perricone@microsemi.com>
Signed-off-by: Don Brace <don.brace@microsemi.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
We need to drop the "ctrl_info->sync_request_sem" lock before returning.
Fixes: 6c223761eb54 ("smartpqi: initial commit of Microsemi smartpqi driver")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Don Brace <don.brace@microsemi.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
struct ufs_dev_cmd is the main container that supports device management
commands. In the case of a read descriptor request, we assume that the
proper space was allocated in dev_cmd to hold the returning descriptor.
This is no longer true, as there are flows that doesn't use dev_cmd for
device management requests, and was wrong in the first place.
Fixes: d44a5f98bb49 (ufs: query descriptor API)
Signed-off-by: Avri Altman <avri.altman@wdc.com>
Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com>
Acked-by: Bean Huo <beanhuo@micron.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
The sas_port(phy->port) allocated in sas_ex_discover_expander() will not be
deleted when the expander failed to discover. This will cause resource leak
and a further issue of kernel BUG like below:
[159785.843156] port-2:17:29: trying to add phy phy-2:17:29 fails: it's
already part of another port
[159785.852144] ------------[ cut here ]------------
[159785.856833] kernel BUG at drivers/scsi/scsi_transport_sas.c:1086!
[159785.863000] Internal error: Oops - BUG: 0 [#1] SMP
[159785.867866] CPU: 39 PID: 16993 Comm: kworker/u96:2 Tainted: G
W OE 4.19.25-vhulk1901.1.0.h111.aarch64 #1
[159785.878458] Hardware name: Huawei Technologies Co., Ltd.
Hi1620EVBCS/Hi1620EVBCS, BIOS Hi1620 CS B070 1P TA 03/21/2019
[159785.889231] Workqueue: 0000:74:02.0_disco_q sas_discover_domain
[159785.895224] pstate: 40c00009 (nZcv daif +PAN +UAO)
[159785.900094] pc : sas_port_add_phy+0x188/0x1b8
[159785.904524] lr : sas_port_add_phy+0x188/0x1b8
[159785.908952] sp : ffff0001120e3b80
[159785.912341] x29: ffff0001120e3b80 x28: 0000000000000000
[159785.917727] x27: ffff802ade8f5400 x26: ffff0000681b7560
[159785.923111] x25: ffff802adf11a800 x24: ffff0000680e8000
[159785.928496] x23: ffff802ade8f5728 x22: ffff802ade8f5708
[159785.933880] x21: ffff802adea2db40 x20: ffff802ade8f5400
[159785.939264] x19: ffff802adea2d800 x18: 0000000000000010
[159785.944649] x17: 00000000821bf734 x16: ffff00006714faa0
[159785.950033] x15: ffff0000e8ab4ecf x14: 7261702079646165
[159785.955417] x13: 726c612073277469 x12: ffff00006887b830
[159785.960802] x11: ffff00006773eaa0 x10: 7968702079687020
[159785.966186] x9 : 0000000000002453 x8 : 726f702072656874
[159785.971570] x7 : 6f6e6120666f2074 x6 : ffff802bcfb21290
[159785.976955] x5 : ffff802bcfb21290 x4 : 0000000000000000
[159785.982339] x3 : ffff802bcfb298c8 x2 : 337752b234c2ab00
[159785.987723] x1 : 337752b234c2ab00 x0 : 0000000000000000
[159785.993108] Process kworker/u96:2 (pid: 16993, stack limit =
0x0000000072dae094)
[159786.000576] Call trace:
[159786.003097] sas_port_add_phy+0x188/0x1b8
[159786.007179] sas_ex_get_linkrate.isra.5+0x134/0x140
[159786.012130] sas_ex_discover_expander+0x128/0x408
[159786.016906] sas_ex_discover_dev+0x218/0x4c8
[159786.021249] sas_ex_discover_devices+0x9c/0x1a8
[159786.025852] sas_discover_root_expander+0x134/0x160
[159786.030802] sas_discover_domain+0x1b8/0x1e8
[159786.035148] process_one_work+0x1b4/0x3f8
[159786.039230] worker_thread+0x54/0x470
[159786.042967] kthread+0x134/0x138
[159786.046269] ret_from_fork+0x10/0x18
[159786.049918] Code: 91322300 f0004402 91178042 97fe4c9b (d4210000)
[159786.056083] Modules linked in: hns3_enet_ut(OE) hclge(OE) hnae3(OE)
hisi_sas_test_hw(OE) hisi_sas_test_main(OE) serdes(OE)
[159786.067202] ---[ end trace 03622b9e2d99e196 ]---
[159786.071893] Kernel panic - not syncing: Fatal exception
[159786.077190] SMP: stopping secondary CPUs
[159786.081192] Kernel Offset: disabled
[159786.084753] CPU features: 0x2,a2a00a38
Fixes: 2908d778ab3e ("[SCSI] aic94xx: new driver")
Reported-by: Jian Luo <luojian5@huawei.com>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
CC: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
When the event queue is full of phy up and down events and reached the
threshold, we will queue a shutdown-event, and set phy->in_shutdown so that
we will not queue a shutdown-event again. But before the shutdown-event can
be executed, every phy-down event will clear
phy->in_shutdown and a new shutdown-event will be queued. The queue will
be full of these shutdown-events.
Fix this by only clear phy->in_shutdown in sas_phye_shutdown(), that is
after the first shutdown-event has been executed.
Fixes: f12486e06ae8 ("scsi: libsas: shut down the PHY if events reached the threshold")
Signed-off-by: Jason Yan <yanaijie@huawei.com>
CC: John Garry <john.garry@huawei.com>
CC: Johannes Thumshirn <jthumshirn@suse.de>
CC: Ewan Milne <emilne@redhat.com>
CC: Christoph Hellwig <hch@lst.de>
CC: Tomas Henzl <thenzl@redhat.com>
CC: Dan Williams <dan.j.williams@intel.com>
CC: Hannes Reinecke <hare@suse.com>
Reviewed-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
If alloc_workqueue fails in alua_init, it should return -ENOMEM, otherwise
it will trigger null-ptr-deref while unloading module which calls
destroy_workqueue dereference
wq->lock like this:
BUG: KASAN: null-ptr-deref in __lock_acquire+0x6b4/0x1ee0
Read of size 8 at addr 0000000000000080 by task syz-executor.0/7045
CPU: 0 PID: 7045 Comm: syz-executor.0 Tainted: G C 5.1.0+ #28
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1
Call Trace:
dump_stack+0xa9/0x10e
__kasan_report+0x171/0x18d
? __lock_acquire+0x6b4/0x1ee0
kasan_report+0xe/0x20
__lock_acquire+0x6b4/0x1ee0
lock_acquire+0xb4/0x1b0
__mutex_lock+0xd8/0xb90
drain_workqueue+0x25/0x290
destroy_workqueue+0x1f/0x3f0
__x64_sys_delete_module+0x244/0x330
do_syscall_64+0x72/0x2a0
entry_SYSCALL_64_after_hwframe+0x49/0xbe
Reported-by: Hulk Robot <hulkci@huawei.com>
Fixes: 03197b61c5ec ("scsi_dh_alua: Use workqueue for RTPG")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
When SME is enabled, the smartpqi driver won't work on the HP DL385 G10
machine, which causes the failure of kernel boot because it fails to
allocate pqi error buffer. Please refer to the kernel log:
....
[ 9.431749] usbcore: registered new interface driver uas
[ 9.441524] Microsemi PQI Driver (v1.1.4-130)
[ 9.442956] i40e 0000:04:00.0: fw 6.70.48768 api 1.7 nvm 10.2.5
[ 9.447237] smartpqi 0000:23:00.0: Microsemi Smart Family Controller found
Starting dracut initqueue hook...
[ OK ] Started Show Plymouth Boot Scre[ 9.471654] Broadcom NetXtreme-C/E driver bnxt_en v1.9.1
en.
[ OK ] Started Forward Password Requests to Plymouth Directory Watch.
[[0;[ 9.487108] smartpqi 0000:23:00.0: failed to allocate PQI error buffer
....
[ 139.050544] dracut-initqueue[949]: Warning: dracut-initqueue timeout - starting timeout scripts
[ 139.589779] dracut-initqueue[949]: Warning: dracut-initqueue timeout - starting timeout scripts
Basically, the fact that the coherent DMA mask value wasn't set caused the
driver to fall back to SWIOTLB when SME is active.
For correct operation, lets call the dma_set_mask_and_coherent() to
properly set the mask for both streaming and coherent, in order to inform
the kernel about the devices DMA addressing capabilities.
Signed-off-by: Lianbo Jiang <lijiang@redhat.com>
Acked-by: Don Brace <don.brace@microsemi.com>
Tested-by: Don Brace <don.brace@microsemi.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
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>
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>
ip_dev_find() can return NULL so add a check for NULL pointer.
Signed-off-by: Varun Prakash <varun@chelsio.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
README