kernel.git/drivers/s390/cio, branch linux-6.8.y

s390/cio: fix tracepoint subchannel type field

2024-05-30T07:48:58Z

[ 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 Signed-off-by: Peter Oberparleiter Signed-off-by: Alexander Gordeev Signed-off-by: Sasha Levin

s390/cio: Ensure the copied buf is NUL terminated

2024-05-17T10:14:32Z

[ Upstream commit da7c622cddd4fe36be69ca61e8c42e43cde94784 ] Currently, we allocate a lbuf-sized kernel buffer and copy lbuf from userspace to that buffer. Later, we use scanf on this buffer but we don't ensure that the string is terminated inside the buffer, this can lead to OOB read when using scanf. Fix this issue by using memdup_user_nul instead. Fixes: a4f17cc72671 ("s390/cio: add CRW inject functionality") Signed-off-by: Bui Quang Minh Reviewed-by: Heiko Carstens Link: https://lore.kernel.org/r/20240424-fix-oob-read-v2-5-f1f1b53a10f4@gmail.com Signed-off-by: Alexander Gordeev Signed-off-by: Sasha Levin

s390/cio: fix race condition during online processing

2024-04-27T15:12:54Z

[ Upstream commit 2d8527f2f911fab84aec04df4788c0c23af3df48 ] A race condition exists in ccw_device_set_online() that can cause the online process to fail, leaving the affected device in an inconsistent state. As a result, subsequent attempts to set that device online fail with return code ENODEV. The problem occurs when a path verification request arrives after a wait for final device state completed, but before the result state is evaluated. Fix this by ensuring that the CCW-device lock is held between determining final state and checking result state. Note that since: commit 2297791c92d0 ("s390/cio: dont unregister subchannel from child-drivers") path verification requests are much more likely to occur during boot, resulting in an increased chance of this race condition occurring. Fixes: 2297791c92d0 ("s390/cio: dont unregister subchannel from child-drivers") Reviewed-by: Alexandra Winter Reviewed-by: Vineeth Vijayan Signed-off-by: Peter Oberparleiter Signed-off-by: Alexander Gordeev Signed-off-by: Sasha Levin

s390/qdio: handle deferred cc1

2024-04-27T15:12:54Z

[ Upstream commit 607638faf2ff1cede37458111496e7cc6c977f6f ] A deferred condition code 1 response indicates that I/O was not started and should be retried. The current QDIO implementation handles a cc1 response as I/O error, resulting in a failed QDIO setup. This can happen for example when a path verification request arrives at the same time as QDIO setup I/O is started. Fix this by retrying the QDIO setup I/O when a cc1 response is received. Note that since commit 2297791c92d0 ("s390/cio: dont unregister subchannel from child-drivers") commit 5ef1dc40ffa6 ("s390/cio: fix invalid -EBUSY on ccw_device_start") deferred cc1 responses are much more likely to occur. See the commit message of the latter for more background information. Fixes: 2297791c92d0 ("s390/cio: dont unregister subchannel from child-drivers") Reviewed-by: Alexandra Winter Signed-off-by: Peter Oberparleiter Signed-off-by: Alexander Gordeev Signed-off-by: Sasha Levin

s390/cio: fix invalid -EBUSY on ccw_device_start

2024-02-22T14:53:15Z

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 Reviewed-by: Thorsten Winkler Signed-off-by: Peter Oberparleiter Signed-off-by: Heiko Carstens

Merge tag 's390-6.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

2024-01-11T02:18:20Z

Pull s390 updates from Alexander Gordeev: - Add machine variable capacity information to /proc/sysinfo. - Limit the waste of page tables and always align vmalloc area size and base address on segment boundary. - Fix a memory leak when an attempt to register interruption sub class (ISC) for the adjunct-processor (AP) guest failed. - Reset response code AP_RESPONSE_INVALID_GISA to understandable by guest AP_RESPONSE_INVALID_ADDRESS in response to a failed interruption sub class (ISC) registration attempt. - Improve reaction to adjunct-processor (AP) AP_RESPONSE_OTHERWISE_CHANGED response code when enabling interrupts on behalf of a guest. - Fix incorrect sysfs 'status' attribute of adjunct-processor (AP) queue device bound to the vfio_ap device driver when the mediated device is attached to a guest, but the queue device is not passed through. - Rework struct ap_card to hold the whole adjunct-processor (AP) card hardware information. As result, all the ugly bit checks are replaced by simple evaluations of the required bit fields. - Improve handling of some weird scenarios between service element (SE) host and SE guest with adjunct-processor (AP) pass-through support. - Change local_ctl_set_bit() and local_ctl_clear_bit() so they return the previous value of the to be changed control register. This is useful if a bit is only changed temporarily and the previous content needs to be restored. - The kernel starts with machine checks disabled and is expected to enable it once trap_init() is called. However the implementation allows machine checks early. Consistently enable it in trap_init() only. - local_mcck_disable() and local_mcck_enable() assume that machine checks are always enabled. Instead implement and use local_mcck_save() and local_mcck_restore() to disable machine checks and restore the previous state. - Modification of floating point control (FPC) register of a traced process using ptrace interface may lead to corruption of the FPC register of the tracing process. Fix this. - kvm_arch_vcpu_ioctl_set_fpu() allows to set the floating point control (FPC) register in vCPU, but may lead to corruption of the FPC register of the host process. Fix this. - Use READ_ONCE() to read a vCPU floating point register value from the memory mapped area. This avoids that, depending on code generation, a different value is tested for validity than the one that is used. - Get rid of test_fp_ctl(), since it is quite subtle to use it correctly. Instead copy a new floating point control register value into its save area and test the validity of the new value when loading it. - Remove superfluous save_fpu_regs() call. - Remove s390 support for ARCH_WANTS_DYNAMIC_TASK_STRUCT. All machines provide the vector facility since many years and the need to make the task structure size dependent on the vector facility does not exist. - Remove the "novx" kernel command line option, as the vector code runs without any problems since many years. - Add the vector facility to the z13 architecture level set (ALS). All hypervisors support the vector facility since many years. This allows compile time optimizations of the kernel. - Get rid of MACHINE_HAS_VX and replace it with cpu_has_vx(). As result, the compiled code will have less runtime checks and less code. - Convert pgste_get_lock() and pgste_set_unlock() ASM inlines to C. - Convert the struct subchannel spinlock from pointer to member. * tag 's390-6.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (24 commits) Revert "s390: update defconfigs" s390/cio: make sch->lock spinlock pointer a member s390: update defconfigs s390/mm: convert pgste locking functions to C s390/fpu: get rid of MACHINE_HAS_VX s390/als: add vector facility to z13 architecture level set s390/fpu: remove "novx" option s390/fpu: remove ARCH_WANTS_DYNAMIC_TASK_STRUCT support KVM: s390: remove superfluous save_fpu_regs() call s390/fpu: get rid of test_fp_ctl() KVM: s390: use READ_ONCE() to read fpc register value KVM: s390: fix setting of fpc register s390/ptrace: handle setting of fpc register correctly s390/nmi: implement and use local_mcck_save() / local_mcck_restore() s390/nmi: consistently enable machine checks in trap_init() s390/ctlreg: return old register contents when changing bits s390/ap: handle outband SE bind state change s390/ap: store TAPQ hwinfo in struct ap_card s390/vfio-ap: fix sysfs status attribute for AP queue devices s390/vfio-ap: improve reaction to response code 07 from PQAP(AQIC) command ...

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

eventfd: simplify eventfd_signal()

2023-11-28T13:08:38Z

Ever since the eventfd type was introduced back in 2007 in commit e1ad7468c77d ("signal/timer/event: eventfd core") the eventfd_signal() function only ever passed 1 as a value for @n. There's no point in keeping that additional argument. Link: https://lore.kernel.org/r/20231122-vfs-eventfd-signal-v2-2-bd549b14ce0c@kernel.org Acked-by: Xu Yilun Acked-by: Andrew Donnellan # ocxl Acked-by: Eric Farman # s390 Reviewed-by: Jan Kara Reviewed-by: Jens Axboe Signed-off-by: Christian Brauner

Merge tag 's390-6.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

2023-11-03T20:17:22Z

Pull s390 updates from Vasily Gorbik: - Get rid of private VM_FAULT flags - Add word-at-a-time implementation - Add DCACHE_WORD_ACCESS support - Cleanup control register handling - Disallow CPU hotplug of CPU 0 to simplify its handling complexity, following a similar restriction in x86 - Optimize pai crypto map allocation - Update the list of crypto express EP11 coprocessor operation modes - Fixes and improvements for secure guests AP pass-through - Several fixes to address incorrect page marking for address translation with the "cmma no-dat" feature, preventing potential incorrect guest TLB flushes - Fix early IPI handling - Several virtual vs physical address confusion fixes - Various small fixes and improvements all over the code * tag 's390-6.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (74 commits) s390/cio: replace deprecated strncpy with strscpy s390/sclp: replace deprecated strncpy with strtomem s390/cio: fix virtual vs physical address confusion s390/cio: export CMG value as decimal s390: delete the unused store_prefix() function s390/cmma: fix handling of swapper_pg_dir and invalid_pg_dir s390/cmma: fix detection of DAT pages s390/sclp: handle default case in sclp memory notifier s390/pai_crypto: remove per-cpu variable assignement in event initialization s390/pai: initialize event count once at initialization s390/pai_crypto: use PERF_ATTACH_TASK define for per task detection s390/mm: add missing arch_set_page_dat() call to gmap allocations s390/mm: add missing arch_set_page_dat() call to vmem_crst_alloc() s390/cmma: fix initial kernel address space page table walk s390/diag: add missing virt_to_phys() translation to diag224() s390/mm,fault: move VM_FAULT_ERROR handling to do_exception() s390/mm,fault: remove VM_FAULT_BADMAP and VM_FAULT_BADACCESS s390/mm,fault: remove VM_FAULT_SIGNAL s390/mm,fault: remove VM_FAULT_BADCONTEXT s390/mm,fault: simplify kfence fault handling ...

s390/cio: replace deprecated strncpy with strscpy

2023-10-25T13:08:30Z

strncpy() is deprecated for use on NUL-terminated destination strings [1] and as such we should prefer more robust and less ambiguous string interfaces. We expect both `params` and `id` to be NUL-terminated based on their usage with format strings: format_node_data(iuparams, iunodeid, &lir->incident_node); format_node_data(auparams, aunodeid, &lir->attached_node); switch (lir->iq.class) { case LIR_IQ_CLASS_DEGRADED: pr_warn("Link degraded: RS=%02x RSID=%04x IC=%02x " "IUPARAMS=%s IUNODEID=%s AUPARAMS=%s AUNODEID=%s\n", sei_area->rs, sei_area->rsid, lir->ic, iuparams, iunodeid, auparams, aunodeid); NUL-padding is not required as both `params` and `id` have been memset to 0: memset(params, 0, PARAMS_LEN); memset(id, 0, NODEID_LEN); Considering the above, a suitable replacement is `strscpy` [2] due to the fact that it guarantees NUL-termination on the destination buffer without unnecessarily NUL-padding. Note that there's no overread bugs in the current implementation as the string literal "n/a" has a size much smaller than PARAMS_LEN or NODEID_LEN. Nonetheless, let's favor strscpy(). Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1] Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2] Link: https://github.com/KSPP/linux/issues/90 Cc: linux-hardening@vger.kernel.org Signed-off-by: Justin Stitt Reviewed-by: Vineeth Vijayan Reviewed-by: Kees Cook Link: https://lore.kernel.org/r/20231023-strncpy-drivers-s390-cio-chsc-c-v1-1-8b76a7b83260@google.com Signed-off-by: Vasily Gorbik