linux.git/drivers/s390/cio/css.c, branch v6.7 Linux kernel source tree s390/cio: fix a memleak in css_alloc_subchannel 2023-10-16T11:03:05+00:00 Dinghao Liu dinghao.liu@zju.edu.cn 2023-09-21T07:14:12+00:00 63e8b94ad1840f02462633abdb363397f56bc642 When dma_set_coherent_mask() fails, sch->lock has not been freed, which is allocated in css_sch_create_locks(), leading to a memleak. Fixes: 4520a91a976e ("s390/cio: use dma helpers for setting masks") Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn> Message-Id: <20230921071412.13806-1-dinghao.liu@zju.edu.cn> Link: https://lore.kernel.org/linux-s390/bd38baa8-7b9d-4d89-9422-7e943d626d6e@linux.ibm.com/ Reviewed-by: Halil Pasic <pasic@linux.ibm.com> Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> 
When dma_set_coherent_mask() fails, sch->lock has not been
freed, which is allocated in css_sch_create_locks(), leading
to a memleak.

Fixes: 4520a91a976e ("s390/cio: use dma helpers for setting masks")
Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn>
Message-Id: <20230921071412.13806-1-dinghao.liu@zju.edu.cn>
Link: https://lore.kernel.org/linux-s390/bd38baa8-7b9d-4d89-9422-7e943d626d6e@linux.ibm.com/
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Merge tag 'driver-core-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core 2023-02-24T20:58:55+00:00 Linus Torvalds torvalds@linux-foundation.org 2023-02-24T20:58:55+00:00 a93e884edf61f9debc9ca61ef9e545f0394ab666 Pull driver core updates from Greg KH: "Here is the large set of driver core changes for 6.3-rc1. There's a lot of changes this development cycle, most of the work falls into two different categories: - fw_devlink fixes and updates. This has gone through numerous review cycles and lots of review and testing by lots of different devices. Hopefully all should be good now, and Saravana will be keeping a watch for any potential regression on odd embedded systems. - driver core changes to work to make struct bus_type able to be moved into read-only memory (i.e. const) The recent work with Rust has pointed out a number of areas in the driver core where we are passing around and working with structures that really do not have to be dynamic at all, and they should be able to be read-only making things safer overall. This is the contuation of that work (started last release with kobject changes) in moving struct bus_type to be constant. We didn't quite make it for this release, but the remaining patches will be finished up for the release after this one, but the groundwork has been laid for this effort. Other than that we have in here: - debugfs memory leak fixes in some subsystems - error path cleanups and fixes for some never-able-to-be-hit codepaths. - cacheinfo rework and fixes - Other tiny fixes, full details are in the shortlog All of these have been in linux-next for a while with no reported problems" [ Geert Uytterhoeven points out that that last sentence isn't true, and that there's a pending report that has a fix that is queued up - Linus ] * tag 'driver-core-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (124 commits) debugfs: drop inline constant formatting for ERR_PTR(-ERROR) OPP: fix error checking in opp_migrate_dentry() debugfs: update comment of debugfs_rename() i3c: fix device.h kernel-doc warnings dma-mapping: no need to pass a bus_type into get_arch_dma_ops() driver core: class: move EXPORT_SYMBOL_GPL() lines to the correct place Revert "driver core: add error handling for devtmpfs_create_node()" Revert "devtmpfs: add debug info to handle()" Revert "devtmpfs: remove return value of devtmpfs_delete_node()" driver core: cpu: don't hand-override the uevent bus_type callback. devtmpfs: remove return value of devtmpfs_delete_node() devtmpfs: add debug info to handle() driver core: add error handling for devtmpfs_create_node() driver core: bus: update my copyright notice driver core: bus: add bus_get_dev_root() function driver core: bus: constify bus_unregister() driver core: bus: constify some internal functions driver core: bus: constify bus_get_kset() driver core: bus: constify bus_register/unregister_notifier() driver core: remove private pointer from struct bus_type ... 
Pull driver core updates from Greg KH:
 "Here is the large set of driver core changes for 6.3-rc1.

  There's a lot of changes this development cycle, most of the work
  falls into two different categories:

   - fw_devlink fixes and updates. This has gone through numerous review
     cycles and lots of review and testing by lots of different devices.
     Hopefully all should be good now, and Saravana will be keeping a
     watch for any potential regression on odd embedded systems.

   - driver core changes to work to make struct bus_type able to be
     moved into read-only memory (i.e. const) The recent work with Rust
     has pointed out a number of areas in the driver core where we are
     passing around and working with structures that really do not have
     to be dynamic at all, and they should be able to be read-only
     making things safer overall. This is the contuation of that work
     (started last release with kobject changes) in moving struct
     bus_type to be constant. We didn't quite make it for this release,
     but the remaining patches will be finished up for the release after
     this one, but the groundwork has been laid for this effort.

  Other than that we have in here:

   - debugfs memory leak fixes in some subsystems

   - error path cleanups and fixes for some never-able-to-be-hit
     codepaths.

   - cacheinfo rework and fixes

   - Other tiny fixes, full details are in the shortlog

  All of these have been in linux-next for a while with no reported
  problems"

[ Geert Uytterhoeven points out that that last sentence isn't true, and
  that there's a pending report that has a fix that is queued up - Linus ]

* tag 'driver-core-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (124 commits)
  debugfs: drop inline constant formatting for ERR_PTR(-ERROR)
  OPP: fix error checking in opp_migrate_dentry()
  debugfs: update comment of debugfs_rename()
  i3c: fix device.h kernel-doc warnings
  dma-mapping: no need to pass a bus_type into get_arch_dma_ops()
  driver core: class: move EXPORT_SYMBOL_GPL() lines to the correct place
  Revert "driver core: add error handling for devtmpfs_create_node()"
  Revert "devtmpfs: add debug info to handle()"
  Revert "devtmpfs: remove return value of devtmpfs_delete_node()"
  driver core: cpu: don't hand-override the uevent bus_type callback.
  devtmpfs: remove return value of devtmpfs_delete_node()
  devtmpfs: add debug info to handle()
  driver core: add error handling for devtmpfs_create_node()
  driver core: bus: update my copyright notice
  driver core: bus: add bus_get_dev_root() function
  driver core: bus: constify bus_unregister()
  driver core: bus: constify some internal functions
  driver core: bus: constify bus_get_kset()
  driver core: bus: constify bus_register/unregister_notifier()
  driver core: remove private pointer from struct bus_type
  ...
driver core: make struct bus_type.uevent() take a const * 2023-01-27T12:45:52+00:00 Greg Kroah-Hartman gregkh@linuxfoundation.org 2023-01-11T11:30:17+00:00 2a81ada32f0e584fc0c943e0d3a8c9f4fae411d6 The uevent() callback in struct bus_type should not be modifying the device that is passed into it, so mark it as a const * and propagate the function signature changes out into all relevant subsystems that use this callback. Acked-by: Rafael J. Wysocki <rafael@kernel.org> Acked-by: Hans de Goede <hdegoede@redhat.com> Link: https://lore.kernel.org/r/20230111113018.459199-16-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
The uevent() callback in struct bus_type should not be modifying the
device that is passed into it, so mark it as a const * and propagate the
function signature changes out into all relevant subsystems that use
this callback.

Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230111113018.459199-16-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
s390/cio: evaluate devices with non-operational paths 2023-01-22T17:42:34+00:00 Vineeth Vijayan vneethv@linux.ibm.com 2022-11-17T06:31:50+00:00 ca34cda73fd4c8fd93c488addc2eeb20af9e923f css_schedule_reprobe() function calls the evaluation for CSS_EVAL_UNREG which is specific to the idset of unregistered subchannels. This evaluation was introduced because, previously, if the underlying device become not-accessible, the subchannel was unregistered. But, in the recent changes in cio,with the commit '2297791c92d0 s390/cio: dont unregister subchannel from child-drivers', we no longer unregister the subchannels just because of a non-operational device. This allows to have subchannels without any operational device connected on it. So, a css_schedule_reprobe function on unregistered subchannel does not have any effect. Change this functionality to evaluate the subchannels which does not have a working path to the device. This could be due the erroneous device or due to the erraneous path. Evaluate based on the values of OPM and PAM&POM. Here we introduced a new idset function,to keep I/O subchannels in the idset when the last seen status indicates that the device has no working path. A device has no working path if all available paths have been tried without success.A failed I/O attempt on a path is indicated as a 0 bit value in the POM mask. By looking at the POM mask bit values of available paths (1 in PAM) that Linux is supposed to use (1 in vary mask OPM), we can identify a non-working device as a device where the bit-wise and of the PAM, POM and OPM mask return 0. css_schedule_reprobe() is being used by dasd-driver and chsc-cio component. dasd driver, when it detects a change in the pathgroup, invokes the re-evaluation of the subchannel. And chsc-cio component upon a CRW event, (resource accessibility event). In both the cases, it makes much better sense to re-evalute the subchannel with no-valid path. Signed-off-by: Vineeth Vijayan <vneethv@linux.ibm.com> Reported-by: Eric Farman <farman@linux.ibm.com> Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com> Tested-by: Eric Farman <farman@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> 
css_schedule_reprobe() function calls the evaluation for CSS_EVAL_UNREG
which is specific to the idset of unregistered subchannels. This
evaluation was introduced because, previously, if the underlying device
become not-accessible, the subchannel was unregistered. But, in the recent
changes in cio,with the commit '2297791c92d0 s390/cio: dont unregister
subchannel from child-drivers', we no  longer unregister the subchannels
just because of a non-operational device. This allows to have subchannels
without any operational device connected on it. So, a css_schedule_reprobe
function on unregistered subchannel does not have any effect.

Change this functionality to evaluate the subchannels which does not
have a working path to the device. This could be due the erroneous
device or due to the erraneous path. Evaluate based on the values of OPM
and PAM&POM.
Here we introduced a new idset function,to keep I/O subchannels in the
idset when the last seen status indicates that the device has no working
path. A device has no working path if all available paths have been tried
without success.A failed I/O attempt on a path is indicated as a 0 bit
value in the POM mask. By looking at the POM mask bit values of available
paths (1 in PAM) that Linux is supposed to use (1 in vary mask OPM), we
can identify a non-working device as a device where the bit-wise and of
the PAM, POM and OPM mask return 0.

css_schedule_reprobe() is being used by dasd-driver and chsc-cio
component. dasd driver, when it detects a change in the pathgroup, invokes
the re-evaluation of the subchannel. And chsc-cio component upon a CRW
event, (resource accessibility event). In both the cases, it makes much
better sense to re-evalute the subchannel with no-valid path.

Signed-off-by: Vineeth Vijayan <vneethv@linux.ibm.com>
Reported-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Tested-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
s390/cio: fix out-of-bounds access on cio_ignore free 2022-10-26T12:47:31+00:00 Peter Oberparleiter oberpar@linux.ibm.com 2022-10-14T10:24:58+00:00 1b6074112742f65ece71b0f299ca5a6a887d2db6 The channel-subsystem-driver scans for newly available devices whenever device-IDs are removed from the cio_ignore list using a command such as: echo free >/proc/cio_ignore Since an I/O device scan might interfer with running I/Os, commit 172da89ed0ea ("s390/cio: avoid excessive path-verification requests") introduced an optimization to exclude online devices from the scan. The newly added check for online devices incorrectly assumes that an I/O-subchannel's drvdata points to a struct io_subchannel_private. For devices that are bound to a non-default I/O subchannel driver, such as the vfio_ccw driver, this results in an out-of-bounds read access during each scan. Fix this by changing the scan logic to rely on a driver-independent online indication. For this we can use struct subchannel->config.ena, which is the driver's requested subchannel-enabled state. Since I/Os can only be started on enabled subchannels, this matches the intent of the original optimization of not scanning devices where I/O might be running. Fixes: 172da89ed0ea ("s390/cio: avoid excessive path-verification requests") Fixes: 0c3812c347bf ("s390/cio: derive cdev information only for IO-subchannels") Cc: <stable@vger.kernel.org> # v5.15 Reported-by: Alexander Egorenkov <egorenar@linux.ibm.com> Reviewed-by: Vineeth Vijayan <vneethv@linux.ibm.com> Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> 
The channel-subsystem-driver scans for newly available devices whenever
device-IDs are removed from the cio_ignore list using a command such as:

  echo free >/proc/cio_ignore

Since an I/O device scan might interfer with running I/Os, commit
172da89ed0ea ("s390/cio: avoid excessive path-verification requests")
introduced an optimization to exclude online devices from the scan.

The newly added check for online devices incorrectly assumes that
an I/O-subchannel's drvdata points to a struct io_subchannel_private.
For devices that are bound to a non-default I/O subchannel driver, such
as the vfio_ccw driver, this results in an out-of-bounds read access
during each scan.

Fix this by changing the scan logic to rely on a driver-independent
online indication. For this we can use struct subchannel->config.ena,
which is the driver's requested subchannel-enabled state. Since I/Os
can only be started on enabled subchannels, this matches the intent
of the original optimization of not scanning devices where I/O might
be running.

Fixes: 172da89ed0ea ("s390/cio: avoid excessive path-verification requests")
Fixes: 0c3812c347bf ("s390/cio: derive cdev information only for IO-subchannels")
Cc: <stable@vger.kernel.org> # v5.15
Reported-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Reviewed-by: Vineeth Vijayan <vneethv@linux.ibm.com>
Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
s390/cio: Use driver_set_override() instead of open-coding 2022-04-22T15:13:54+00:00 Krzysztof Kozlowski krzysztof.kozlowski@linaro.org 2022-04-19T11:34:29+00:00 1e8ee51212b4876f1a8ca4b78d2499e2fc442cf3 Use a helper to set driver_override to the reduce amount of duplicated code. Make the driver_override field const char, because it is not modified by the core and it matches other subsystems. Acked-by: Vineeth Vijayan <vneethv@linux.ibm.com> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Link: https://lore.kernel.org/r/20220419113435.246203-7-krzysztof.kozlowski@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Use a helper to set driver_override to the reduce amount of duplicated
code.  Make the driver_override field const char, because it is not
modified by the core and it matches other subsystems.

Acked-by: Vineeth Vijayan <vneethv@linux.ibm.com>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20220419113435.246203-7-krzysztof.kozlowski@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
s390/cio: remove uevent suppress from cio driver 2021-12-06T13:42:24+00:00 Vineeth Vijayan vneethv@linux.ibm.com 2021-06-29T07:38:22+00:00 a84d1c5006b56166dac477e922643ede01cdbb92 commit fa1a8c23eb7d ("s390: cio: Delay uevents for subchannels") introduced suppression of uevents for a subchannel until after it is clear that the subchannel would not be unregistered again immediately. This was done to avoid uevents being generated for I/O subchannels with no valid device, which can happen on LPAR. However, this also has some drawbacks: All subchannel drivers need to manually remove the uevent suppression and generate an ADD uevent as soon as they are sure that the subchannel will stay around. This misses out on all uevents that are not the initial ADD uevent that would be generated while uevents are suppressed; for example, all subchannels were missing the BIND uevent. As uevents being generated even for I/O subchannels without an operational device turned out to be not as bad as missing uevents and complicating the code flow, let's remove uevent suppression for subchannels. Signed-off-by: Vineeth Vijayan <vneethv@linux.ibm.com> [cohuck@redhat.com: modified changelog] Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com> Link: https://lore.kernel.org/r/20211122103756.352463-2-vneethv@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com> 
commit fa1a8c23eb7d ("s390: cio: Delay uevents for subchannels")
introduced suppression of uevents for a subchannel until after it is
clear that the subchannel would not be unregistered again
immediately. This was done to avoid uevents being generated for I/O
subchannels with no valid device, which can happen on LPAR.

However, this also has some drawbacks: All subchannel drivers need to
manually remove the uevent suppression and generate an ADD uevent as
soon as they are sure that the subchannel will stay around. This misses
out on all uevents that are not the initial ADD uevent that would be
generated while uevents are suppressed; for example, all subchannels
were missing the BIND uevent.

As uevents being generated even for I/O subchannels without an
operational device turned out to be not as bad as missing uevents and
complicating the code flow, let's remove uevent suppression for
subchannels.

Signed-off-by: Vineeth Vijayan <vneethv@linux.ibm.com>
[cohuck@redhat.com: modified changelog]
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Link: https://lore.kernel.org/r/20211122103756.352463-2-vneethv@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
s390/cio: check the subchannel validity for dev_busid 2021-11-08T13:17:49+00:00 Vineeth Vijayan vneethv@linux.ibm.com 2021-11-05T15:44:51+00:00 a4751f157c194431fae9e9c493f456df8272b871 Check the validity of subchanel before reading other fields in the schib. Fixes: d3683c055212 ("s390/cio: add dev_busid sysfs entry for each subchannel") CC: <stable@vger.kernel.org> Reported-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Vineeth Vijayan <vneethv@linux.ibm.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Link: https://lore.kernel.org/r/20211105154451.847288-1-vneethv@linux.ibm.com Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> 
Check the validity of subchanel before reading other fields in
the schib.

Fixes: d3683c055212 ("s390/cio: add dev_busid sysfs entry for each subchannel")
CC: <stable@vger.kernel.org>
Reported-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Vineeth Vijayan <vneethv@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Link: https://lore.kernel.org/r/20211105154451.847288-1-vneethv@linux.ibm.com
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
s390/cio: derive cdev information only for IO-subchannels 2021-10-04T07:49:36+00:00 Vineeth Vijayan vneethv@linux.ibm.com 2021-09-17T13:04:01+00:00 0c3812c347bfb0dc213556a195e79850c55702f5 cdev->online for the purge function must not be checked for the non-IO subchannel type. Make sure that we are deriving the cdev only from sch-type SUBCHANNEL_TYPE_IO. Signed-off-by: Vineeth Vijayan <vneethv@linux.ibm.com> Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> 
cdev->online for the purge function must not be checked for the
non-IO subchannel type. Make sure that we are deriving the cdev only
from sch-type SUBCHANNEL_TYPE_IO.

Signed-off-by: Vineeth Vijayan <vneethv@linux.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
s390/cio: avoid excessive path-verification requests 2021-09-27T11:54:38+00:00 Vineeth Vijayan vneethv@linux.ibm.com 2021-09-10T11:45:24+00:00 172da89ed0eaf9d9348f5decb86ad04c624b39d1 Currently when removing a device from cio_ignore list, we trigger a path-verification for all the subchannels available in the system. This could lead to path-verification requests on subchannels with an online device, which could cause unwanted delay. Instead of all the subchannels, trigger the path-verifications to those without an online device. Reported-by: Julian Wiedmann <jwi@linux.ibm.com> Fixes: 2297791c92d0 ("s390/cio: dont unregister subchannel from child-drivers") Signed-off-by: Vineeth Vijayan <vneethv@linux.ibm.com> Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> 
Currently when removing a device from cio_ignore list, we trigger a
path-verification for all the subchannels available in the system. This
could lead to path-verification requests on subchannels with an online
device, which could cause unwanted delay. Instead of all the
subchannels, trigger the path-verifications to those without an online
device.

Reported-by: Julian Wiedmann <jwi@linux.ibm.com>
Fixes: 2297791c92d0 ("s390/cio: dont unregister subchannel from child-drivers")
Signed-off-by: Vineeth Vijayan <vneethv@linux.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>