kernel/linux.git/drivers/s390/cio/css.c, branch v6.12.80

s390/cio: Fix device lifecycle handling in css_alloc_subchannel()

2026-03-04T12:19:32+00:00

[ Upstream commit f65c75b0b9b5a390bc3beadcde0a6fbc3ad118f7 ] `css_alloc_subchannel()` calls `device_initialize()` before setting up the DMA masks. If `dma_set_coherent_mask()` or `dma_set_mask()` fails, the error path frees the subchannel structure directly, bypassing the device model reference counting. Once `device_initialize()` has been called, the embedded struct device must be released via `put_device()`, allowing the release callback to free the container structure. Fix the error path by dropping the initial device reference with `put_device()` instead of calling `kfree()` directly. This ensures correct device lifetime handling and avoids potential use-after-free or double-free issues. Fixes: e5dcf0025d7af ("s390/css: move subchannel lock allocation") Signed-off-by: Salah Triki Reviewed-by: Vineeth Vijayan Signed-off-by: Heiko Carstens Signed-off-by: Sasha Levin

[tree-wide] finally take no_llseek out

2024-09-27T15:18:43+00:00

no_llseek had been defined to NULL two years ago, in commit 868941b14441 ("fs: remove no_llseek") To quote that commit, At -rc1 we'll need do a mechanical removal of no_llseek - git grep -l -w no_llseek | grep -v porting.rst | while read i; do sed -i '/\/d' $i done would do it. Unfortunately, that hadn't been done. Linus, could you do that now, so that we could finally put that thing to rest? All instances are of the form .llseek = no_llseek, so it's obviously safe. Signed-off-by: Al Viro Signed-off-by: Linus Torvalds

driver core: have match() callback in struct bus_type take a const *

2024-07-03T13:16:54+00:00

In the match() callback, the struct device_driver * should not be changed, so change the function callback to be a const *. This is one step of many towards making the driver core safe to have struct device_driver in read-only memory. Because the match() callback is in all busses, all busses are modified to handle this properly. This does entail switching some container_of() calls to container_of_const() to properly handle the constant *. For some busses, like PCI and USB and HV, the const * is cast away in the match callback as those busses do want to modify those structures at this point in time (they have a local lock in the driver structure.) That will have to be changed in the future if they wish to have their struct device * in read-only-memory. Cc: Rafael J. Wysocki Reviewed-by: Alex Elder Acked-by: Sumit Garg Link: https://lore.kernel.org/r/2024070136-wrongdoer-busily-01e8@gregkh Signed-off-by: Greg Kroah-Hartman

s390/cio: convert sprintf()/snprintf() to sysfs_emit()

2024-04-09T15:29:56+00:00

Per filesystems/sysfs.rst, show() should only use sysfs_emit() or sysfs_emit_at() when formatting the value to be returned to user space. coccinelle complains that there are still a couple of functions that use snprintf(). Convert them to sysfs_emit(). Generally, this patch is generated by make coccicheck M= MODE=patch \ COCCI=scripts/coccinelle/api/device_attr_show.cocci No functional change intended. Cc: Vineeth Vijayan Cc: Peter Oberparleiter Signed-off-by: Li Zhijian Link: https://lore.kernel.org/r/20240314095209.1325229-1-lizhijian@fujitsu.com Signed-off-by: Heiko Carstens Signed-off-by: Alexander Gordeev

s390/virtio_ccw: use DMA handle from DMA API

2024-03-13T08:23:46+00:00

Change and use ccw_device_dma_zalloc() so it returns a virtual address like before, which can be used to access data. However also pass a new dma32_t pointer type handle, which correlates to the returned virtual address. This pointer is used to directly pass/set the DMA handle as returned by the DMA API. Signed-off-by: Halil Pasic Reviewed-by: Eric Farman Signed-off-by: Heiko Carstens

s390/cio: make css_bus_type const

2024-02-09T12:58:15+00:00

Now that the driver core can properly handle constant struct bus_type, move the css_bus_type variable to be a constant structure as well, placing it into read-only memory which can not be modified at runtime. Cc: Greg Kroah-Hartman Suggested-by: Greg Kroah-Hartman Signed-off-by: "Ricardo B. Marliere" Reviewed-by: Greg Kroah-Hartman Link: https://lore.kernel.org/r/20240203-bus_cleanup-s390-v1-2-ac891afc7282@marliere.net Signed-off-by: Heiko Carstens

s390/cio: make sch->lock spinlock pointer a member

2023-12-12T13:41:58+00:00

The lock member of struct subchannel used to be a spinlock, but became a pointer to a spinlock with commit 2ec2298412e1 ("[S390] subchannel lock conversion."). This might have been justified back then, but with the current state of affairs, there is no reason to manage a separate spinlock object. Let's simplify things and pull the spinlock back into struct subchannel. Signed-off-by: Halil Pasic Reviewed-by: Vineeth Vijayan Link: https://lore.kernel.org/r/20231101115751.2308307-1-pasic@linux.ibm.com Signed-off-by: Vasily Gorbik Signed-off-by: Alexander Gordeev

s390/cio: fix a memleak in css_alloc_subchannel

2023-10-16T11:03:05+00:00

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 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 Reviewed-by: Peter Oberparleiter Signed-off-by: Vasily Gorbik

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

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

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 Acked-by: Hans de Goede Link: https://lore.kernel.org/r/20230111113018.459199-16-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman