kernel.git/drivers/s390/cio/css.c, branch linux-rolling-stable

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

2026-02-26T23:00:44Z

[ 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

s390: Remove KMSG_COMPONENT macro

2025-11-24T10:45:21Z

The KMSG_COMPONENT macro is a leftover of the s390 specific "kernel message catalog" which never made it upstream. Remove the macro in order to get rid of a pointless indirection. Replace all users with the string it defines. In almost all cases this leads to a simple replacement like this: - #define KMSG_COMPONENT "appldata" - #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt + #define pr_fmt(fmt) "appldata: " fmt Except for some special cases this is just mechanical/scripted work. Acked-by: Thomas Richter Signed-off-by: Heiko Carstens

s390/cio/css: Switch over to sysfs_emit()

2024-10-25T14:03:25Z

Per Documentation/filesystems/sysfs.rst, sysfs_emit() is preferred for presenting attributes to user space in sysfs. Convert the left-over uses in the cio/css code. Signed-off-by: Mete Durlu Acked-by: Vineeth Vijayan Tested-by: Vineeth Vijayan Reviewed-by: Heiko Carstens Signed-off-by: Heiko Carstens

[tree-wide] finally take no_llseek out

2024-09-27T15:18:43Z

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 *

2024-07-03T13:16:54Z

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()

2024-04-09T15:29:56Z

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

2024-03-13T08:23:46Z

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

2024-02-09T12:58:15Z

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

2023-12-12T13:41:58Z

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

2023-10-16T11:03:05Z

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