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2021-06-10scsi: blkcg: Add app identifier support for blkcgMuneendra Kumar
Add a unique application identifier (i.e fc_app_id member) in blkcg. This allows identification of traffic belonging to an specific both on the host and in the fabric infrastructure. As an example, this allows the storage stack to uniquely identify traffic belong to particular virtual machine. Link: https://lore.kernel.org/r/20210608043556.274139-3-muneendra.kumar@broadcom.com Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Muneendra Kumar <muneendra.kumar@broadcom.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-06-10scsi: cgroup: Add cgroup_get_from_id()Muneendra Kumar
Add a new function, cgroup_get_from_id(), to retrieve the cgroup associated with a cgroup id. Also export the function cgroup_get_e_css() as this is needed in blk-cgroup.h. Link: https://lore.kernel.org/r/20210608043556.274139-2-muneendra.kumar@broadcom.com Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Muneendra Kumar <muneendra.kumar@broadcom.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-06-10scsi: fc: FDMI enhancementJaved Hasan
Added RHBA and RPA attributes type and length. As per FC_GC_7 document section "Table 400 – Attribute Entry Types and associated Values" ASCII type attributes length can be vary from "4 to 256 byte". If we keep all RHBA ASCII attributes length 256 then total length is going upto 2750, which is far more than 2048 (max frame size). In libfc we do have logic to split FCP commands but not for CT commands. Practically all version/names get covered with in 64 bytes except OS name, for that we need 128 bytes. Hence length of all RBHA ASCII attributes is reduced to 64 bytes and 128 bytes in case of OS name. RPA attributes total length is within frame size. Link: https://lore.kernel.org/r/20210603121623.10084-6-jhasan@marvell.com Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com> Signed-off-by: Javed Hasan <jhasan@marvell.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-06-10scsi: libfc: Add FDMI-2 attributesJaved Hasan
Add all attributes for RHBA and RPA registration. Fallback mechanism is added between RBHA V2 and RHBA V1 attributes. In case RHBA get fails for V2 attributes we fall back to V1 attribute registration. Link: https://lore.kernel.org/r/20210603121623.10084-4-jhasan@marvell.com Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com> Signed-off-by: Javed Hasan <jhasan@marvell.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-06-09scsi: fc: Correct RHBA attributes lengthJaved Hasan
As per the FC-GS-5 specification, attribute lengths of node_name and manufacturer should in range of "4 to 64 Bytes" only. Link: https://lore.kernel.org/r/20210603101404.7841-2-jhasan@marvell.com Fixes: e721eb0616f6 ("scsi: scsi_transport_fc: Match HBA Attribute Length with HBAAPI V2.0 definitions") CC: stable@vger.kernel.org Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com> Signed-off-by: Javed Hasan <jhasan@marvell.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-06-02scsi: core: Change the type of the second argument of ↵Bart Van Assche
scsi_host_complete_all_commands() Allow the compiler to verify the type of the second argument passed to scsi_host_complete_all_commands(). Link: https://lore.kernel.org/r/20210524025457.11299-4-bvanassche@acm.org Cc: Hannes Reinecke <hare@suse.com> Cc: John Garry <john.garry@huawei.com> Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-06-02scsi: core: Introduce enums for the SAM and host status codesBart Van Assche
Make it possible for the compiler to verify whether SAM and host status codes are used correctly. [mkp: resolve conflicts with Hannes' SCSI result series] Link: https://lore.kernel.org/r/20210524025457.11299-3-bvanassche@acm.org Cc: Hannes Reinecke <hare@suse.com> Reviewed-by: John Garry <john.garry@huawei.com> Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-06-02scsi: libsas: Introduce more SAM status code aliases in enum exec_statusBart Van Assche
This patch prepares for converting SAM status codes into an enum. Without this patch converting SAM status codes into an enumeration type would trigger complaints about enum type mismatches for the SAS code. Link: https://lore.kernel.org/r/20210524025457.11299-2-bvanassche@acm.org Cc: Hannes Reinecke <hare@suse.com> Cc: Artur Paszkiewicz <artur.paszkiewicz@intel.com> Cc: Jason Yan <yanaijie@huawei.com> Reviewed-by: John Garry <john.garry@huawei.com> Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com> Acked-by: Jack Wang <jinpu.wang@ionos.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-06-02Merge branch '5.14/scsi-result' into 5.14/scsi-stagingMartin K. Petersen
Include Hannes' SCSI command result rework in the staging branch. [mkp: remove DRIVER_SENSE from mpi3mr] Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-06-02scsi: iscsi: Hold task ref during TMF timeout handlingMike Christie
For aborts, qedi needs to cleanup the FW then send the TMF from a worker thread. While it's doing these the cmd could complete normally and the TMF could time out. libiscsi would then complete the iscsi_task which will call into the driver to cleanup the driver level resources while it still might be accessing them for the cleanup/abort. This has iscsi_eh_abort keep the iscsi_task ref if the TMF times out, so qedi does not have to worry about if the task is being freed while in use and does not need to get its own ref. Link: https://lore.kernel.org/r/20210525181821.7617-18-michael.christie@oracle.com Reviewed-by: Lee Duncan <lduncan@suse.com> Signed-off-by: Mike Christie <michael.christie@oracle.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-06-02scsi: iscsi: Fix conn use after free during resetsMike Christie
If we haven't done a unbind target call we can race where iscsi_conn_teardown wakes up the EH thread and then frees the conn while those threads are still accessing the conn ehwait. We can only do one TMF per session so this just moves the TMF fields from the conn to the session. We can then rely on the iscsi_session_teardown->iscsi_remove_session->__iscsi_unbind_session call to remove the target and it's devices, and know after that point there is no device or scsi-ml callout trying to access the session. Link: https://lore.kernel.org/r/20210525181821.7617-14-michael.christie@oracle.com Reviewed-by: Lee Duncan <lduncan@suse.com> Signed-off-by: Mike Christie <michael.christie@oracle.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-06-02scsi: iscsi: Add iscsi_cls_conn refcount helpersMike Christie
There are a couple places where we could free the iscsi_cls_conn while it's still in use. This adds some helpers to get/put a refcount on the struct and converts an exiting user. Subsequent commits will then use the helpers to fix 2 bugs in the eh code. Link: https://lore.kernel.org/r/20210525181821.7617-11-michael.christie@oracle.com Reviewed-by: Lee Duncan <lduncan@suse.com> Signed-off-by: Mike Christie <michael.christie@oracle.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-06-02scsi: iscsi: Fix in-kernel conn failure handlingMike Christie
Commit 0ab710458da1 ("scsi: iscsi: Perform connection failure entirely in kernel space") has the following regressions/bugs that this patch fixes: 1. It can return cmds to upper layers like dm-multipath where that can retry them. After they are successful the fs/app can send new I/O to the same sectors, but we've left the cmds running in FW or in the net layer. We need to be calling ep_disconnect if userspace is not up. This patch only fixes the issue for offload drivers. iscsi_tcp will be fixed in separate commit because it doesn't have a ep_disconnect call. 2. The drivers that implement ep_disconnect expect that it's called before conn_stop. Besides crashes, if the cleanup_task callout is called before ep_disconnect it might free up driver/card resources for session1 then they could be allocated for session2. But because the driver's ep_disconnect is not called it has not cleaned up the firmware so the card is still using the resources for the original cmd. 3. The stop_conn_work_fn can run after userspace has done its recovery and we are happily using the session. We will then end up with various bugs depending on what is going on at the time. We may also run stop_conn_work_fn late after userspace has called stop_conn and ep_disconnect and is now going to call start/bind conn. If stop_conn_work_fn runs after bind but before start, we would leave the conn in a unbound but sort of started state where IO might be allowed even though the drivers have been set in a state where they no longer expect I/O. 4. Returning -EAGAIN in iscsi_if_destroy_conn if we haven't yet run the in kernel stop_conn function is breaking userspace. We should have been doing this for the caller. Link: https://lore.kernel.org/r/20210525181821.7617-8-michael.christie@oracle.com Fixes: 0ab710458da1 ("scsi: iscsi: Perform connection failure entirely in kernel space") Reviewed-by: Lee Duncan <lduncan@suse.com> Signed-off-by: Mike Christie <michael.christie@oracle.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-06-02scsi: iscsi: Rel ref after iscsi_lookup_endpoint()Mike Christie
Subsequent commits allow the kernel to do ep_disconnect. In that case we will have to get a proper refcount on the ep so one thread does not delete it from under another. Link: https://lore.kernel.org/r/20210525181821.7617-7-michael.christie@oracle.com Reviewed-by: Lee Duncan <lduncan@suse.com> Signed-off-by: Mike Christie <michael.christie@oracle.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-06-02scsi: iscsi: Stop queueing during ep_disconnectMike Christie
During ep_disconnect we have been doing iscsi_suspend_tx/queue to block new I/O but every driver except cxgbi and iscsi_tcp can still get I/O from __iscsi_conn_send_pdu() if we haven't called iscsi_conn_failure() before ep_disconnect. This could happen if we were terminating the session, and the logout timed out before it was even sent to libiscsi. Fix the issue by adding a helper which reverses the bind_conn call that allows new I/O to be queued. Drivers implementing ep_disconnect can use this to make sure new I/O is not queued to them when handling the disconnect. Link: https://lore.kernel.org/r/20210525181821.7617-3-michael.christie@oracle.com Reviewed-by: Lee Duncan <lduncan@suse.com> Signed-off-by: Mike Christie <michael.christie@oracle.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-06-02scsi: iscsi: Add task completion helperMike Christie
This adds a helper to detect if a cmd has completed but is not yet freed. Link: https://lore.kernel.org/r/20210525181821.7617-2-michael.christie@oracle.com Reviewed-by: Lee Duncan <lduncan@suse.com> Signed-off-by: Mike Christie <michael.christie@oracle.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-05-31scsi: core: Drop obsolete Linux-specific SCSI status codesHannes Reinecke
Originally the SCSI subsystem has been using 'special' SCSI status codes, which were the SAM-specified ones but shifted by 1. As most drivers have now been modified to use the SAM-specified ones, having two nearly identical sets of definitions only causes confusion. The Linux-specifed SCSI status codes have been marked obsolete for several years so drop them and use the SAM-specified status codes throughout. Link: https://lore.kernel.org/r/20210427083046.31620-41-hare@suse.de Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Douglas Gilbert <dgilbert@interlog.com> Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-05-31scsi: core: Kill message byteHannes Reinecke
Remove last vestiges of SCSI status message bytes. Link: https://lore.kernel.org/r/20210427083046.31620-39-hare@suse.de Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-05-31scsi: core: Drop message byte helperHannes Reinecke
The message byte is now unused, so we can drop the helper to set the message byte and the check for message bytes during error recovery. Link: https://lore.kernel.org/r/20210427083046.31620-38-hare@suse.de Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-05-31scsi: core: Add scsi_msg_to_host_byte()Hannes Reinecke
Add helper to convert message byte into a host byte code. Link: https://lore.kernel.org/r/20210427083046.31620-18-hare@suse.de Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-05-31scsi: core: Add get_{status,host}_byte() accessor functionsHannes Reinecke
Add accessor functions for the host and status byte. Link: https://lore.kernel.org/r/20210427083046.31620-17-hare@suse.de Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-05-31scsi: core: Drop the now obsolete driver_byte definitionsHannes Reinecke
The driver_byte field in the result is now unused, so we can drop the definitions. Link: https://lore.kernel.org/r/20210427083046.31620-15-hare@suse.de Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-05-31scsi: core: Kill DRIVER_SENSEHannes Reinecke
Replace the check for DRIVER_SENSE with a check for scsi_status_is_check_condition(). Audit all callsites to ensure the SAM status is set correctly. For backwards compability move the DRIVER_SENSE definition to sg.h, and update sg, bsg, and scsi_ioctl to set the DRIVER_SENSE driver_status whenever SAM_STAT_CHECK_CONDITION is present. [mkp: fix zeroday srp warning] Link: https://lore.kernel.org/r/20210427083046.31620-10-hare@suse.de Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> fix
2021-05-31scsi: core: Introduce scsi_status_is_check_condition()Hannes Reinecke
Add a helper function scsi_status_is_check_condition() to encapsulate the frequent checks for SAM_STAT_CHECK_CONDITION. Link: https://lore.kernel.org/r/20210427083046.31620-9-hare@suse.de Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-05-31scsi: core: Introduce scsi_build_sense()Hannes Reinecke
Introduce scsi_build_sense() as a wrapper around scsi_build_sense_buffer() to format the buffer and set the correct SCSI status. Link: https://lore.kernel.org/r/20210427083046.31620-8-hare@suse.de Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-05-31scsi: core: Stop using DRIVER_ERRORHannes Reinecke
Return the actual error code in __scsi_execute() (which, according to the documentation, should have happened anyway). And audit all callers to cope with negative return values from __scsi_execute() and friends. [mkp: resolve conflict and return bool] Link: https://lore.kernel.org/r/20210427083046.31620-7-hare@suse.de Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-05-21scsi: Fix spelling mistakes in header filesZhen Lei
Fix some spelling mistakes in comments: pathes ==> paths Resouce ==> Resource retreived ==> retrieved recevied ==> received interruped ==> interrupted [mkp: kept 'keep-alives' and 'busses'] Link: https://lore.kernel.org/r/20210517095945.7363-1-thunder.leizhen@huawei.com Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-05-15scsi: target: core: Add the VERSION DESCRIPTOR fields to the INQUIRY dataKonstantin Shelekhin
Extend the standard INQUIRY data to 96 bytes and fill in the VERSION DESCRIPTOR fields. The layout follows SPC-4: - SCSI architecture standard - SCSI transport protocol standard - SCSI primary command set standard - SCSI device type command set standard All version descriptor values are defined as "no version claimed" because some initiators fail to recognize anything else. [mkp: whitespace] Link: https://lore.kernel.org/r/20210513192804.1252142-3-k.shelekhin@yadro.com Reviewed-by: Roman Bolshakov <r.bolshakov@yadro.com> Signed-off-by: Konstantin Shelekhin <k.shelekhin@yadro.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-05-15scsi: target: core: Add configurable IEEE Company ID attributeSergey Samoylenko
Implement an attribute which provides a way to set a company specific WWN in configfs via: target/core/$backstore/$name/wwn/company_id The Open Fabrics Alliance ID 001405h remains the default. Link: https://lore.kernel.org/r/20210420185920.42431-3-s.samoylenko@yadro.com Signed-off-by: Sergey Samoylenko <s.samoylenko@yadro.com> Signed-off-by: Roman Bolshakov <r.bolshakov@yadro.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-05-10scsi: ufs: core: Enable power management for wlunAsutosh Das
During runtime-suspend of ufs host, the SCSI devices are already suspended and so are the queues associated with them. However, the ufs host sends SSU (START_STOP_UNIT) to the wlun during runtime-suspend. During the process blk_queue_enter() checks if the queue is not in suspended state. If so, it waits for the queue to resume, and never comes out of it. Commit 52abca64fd94 ("scsi: block: Do not accept any requests while suspended") adds the check to see if the queue is in suspended state in blk_queue_enter(). Call trace: __switch_to+0x174/0x2c4 __schedule+0x478/0x764 schedule+0x9c/0xe0 blk_queue_enter+0x158/0x228 blk_mq_alloc_request+0x40/0xa4 blk_get_request+0x2c/0x70 __scsi_execute+0x60/0x1c4 ufshcd_set_dev_pwr_mode+0x124/0x1e4 ufshcd_suspend+0x208/0x83c ufshcd_runtime_suspend+0x40/0x154 ufshcd_pltfrm_runtime_suspend+0x14/0x20 pm_generic_runtime_suspend+0x28/0x3c __rpm_callback+0x80/0x2a4 rpm_suspend+0x308/0x614 rpm_idle+0x158/0x228 pm_runtime_work+0x84/0xac process_one_work+0x1f0/0x470 worker_thread+0x26c/0x4c8 kthread+0x13c/0x320 ret_from_fork+0x10/0x18 Fix this by registering ufs device wlun as a SCSI driver and registering it for block runtime-pm. Also make this a supplier for all other LUNs. This way the wlun device suspends after all the consumers and resumes after HBA resumes. This also registers a new SCSI driver for rpmb wlun. This new driver is mostly used to clear rpmb uac. [mkp: resolve merge conflict with 5.13-rc1 and fix doc warning] Fixed smatch warnings: Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Link: https://lore.kernel.org/r/4662c462e79e3e7f541f54f88f8993f421026d83.1619223249.git.asutoshd@codeaurora.org Reviewed-by: Adrian Hunter <adrian.hunter@intel.com> Co-developed-by: Can Guo <cang@codeaurora.org> Signed-off-by: Can Guo <cang@codeaurora.org> Signed-off-by: Asutosh Das <asutoshd@codeaurora.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-05-10scsi: core: Treat device offline as a failureJason Yan
When a SCSI device is offline a MODE SENSE command will return a result with only DID_NO_CONNECT set. In sd_read_write_protect_flag() only the status byte of the result is checked. Despite a returned status of DID_NO_CONNECT the command is considered successful and we read sdkp->write_prot from a buffer containing garbage. Modify scsi_status_is_good() to treat DID_NO_CONNECT as a failure case. Link: https://lore.kernel.org/r/20210330114727.234467-1-yanaijie@huawei.com Signed-off-by: Jason Yan <yanaijie@huawei.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-05-09Merge tag 'block-5.13-2021-05-09' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block fix from Jens Axboe: "Turns out the bio max size change still has issues, so let's get it reverted for 5.13-rc1. We'll shake out the issues there and defer it to 5.14 instead" * tag 'block-5.13-2021-05-09' of git://git.kernel.dk/linux-block: Revert "bio: limit bio max size"
2021-05-09Merge tag 'locking-urgent-2021-05-09' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking fixes from Thomas Gleixner: "A set of locking related fixes and updates: - Two fixes for the futex syscall related to the timeout handling. FUTEX_LOCK_PI does not support the FUTEX_CLOCK_REALTIME bit and because it's not set the time namespace adjustment for clock MONOTONIC is applied wrongly. FUTEX_WAIT cannot support the FUTEX_CLOCK_REALTIME bit because its always a relative timeout. - Cleanups in the futex syscall entry points which became obvious when the two timeout handling bugs were fixed. - Cleanup of queued_write_lock_slowpath() as suggested by Linus - Fixup of the smp_call_function_single_async() prototype" * tag 'locking-urgent-2021-05-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: futex: Make syscall entry points less convoluted futex: Get rid of the val2 conditional dance futex: Do not apply time namespace adjustment on FUTEX_LOCK_PI Revert 337f13046ff0 ("futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op") locking/qrwlock: Cleanup queued_write_lock_slowpath() smp: Fix smp_call_function_single_async prototype
2021-05-09Merge tag 'x86_urgent_for_v5.13_rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Borislav Petkov: "A bunch of things accumulated for x86 in the last two weeks: - Fix guest vtime accounting so that ticks happening while the guest is running can also be accounted to it. Along with a consolidation to the guest-specific context tracking helpers. - Provide for the host NMI handler running after a VMX VMEXIT to be able to run on the kernel stack correctly. - Initialize MSR_TSC_AUX when RDPID is supported and not RDTSCP (virt relevant - real hw supports both) - A code generation improvement to TASK_SIZE_MAX through the use of alternatives - The usual misc and related cleanups and improvements" * tag 'x86_urgent_for_v5.13_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: KVM: x86: Consolidate guest enter/exit logic to common helpers context_tracking: KVM: Move guest enter/exit wrappers to KVM's domain context_tracking: Consolidate guest enter/exit wrappers sched/vtime: Move guest enter/exit vtime accounting to vtime.h sched/vtime: Move vtime accounting external declarations above inlines KVM: x86: Defer vtime accounting 'til after IRQ handling context_tracking: Move guest exit vtime accounting to separate helpers context_tracking: Move guest exit context tracking to separate helpers KVM/VMX: Invoke NMI non-IST entry instead of IST entry x86/cpu: Remove write_tsc() and write_rdtscp_aux() wrappers x86/cpu: Initialize MSR_TSC_AUX if RDTSCP *or* RDPID is supported x86/resctrl: Fix init const confusion x86: Delete UD0, UD1 traces x86/smpboot: Remove duplicate includes x86/cpu: Use alternative to generate the TASK_SIZE_MAX constant
2021-05-08Revert "bio: limit bio max size"Jens Axboe
This reverts commit cd2c7545ae1beac3b6aae033c7f31193b3255946. Alex reports that the commit causes corruption with LUKS on ext4. Revert it for now so that this can be investigated properly. Link: https://lore.kernel.org/linux-block/1620493841.bxdq8r5haw.none@localhost/ Reported-by: Alex Xu (Hello71) <alex_y_xu@yahoo.ca> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-05-08Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsiLinus Torvalds
Pull more SCSI updates from James Bottomley: "This is a set of minor fixes in various drivers (qla2xxx, ufs, scsi_debug, lpfc) one doc fix and a fairly large update to the fnic driver to remove the open coded iteration functions in favour of the scsi provided ones" * tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: scsi: fnic: Use scsi_host_busy_iter() to traverse commands scsi: fnic: Kill 'exclude_id' argument to fnic_cleanup_io() scsi: scsi_debug: Fix cmd_per_lun, set to max_queue scsi: ufs: core: Narrow down fast path in system suspend path scsi: ufs: core: Cancel rpm_dev_flush_recheck_work during system suspend scsi: ufs: core: Do not put UFS power into LPM if link is broken scsi: qla2xxx: Prevent PRLI in target mode scsi: qla2xxx: Add marginal path handling support scsi: target: tcmu: Return from tcmu_handle_completions() if cmd_id not found scsi: ufs: core: Fix a typo in ufs-sysfs.c scsi: lpfc: Fix bad memory access during VPD DUMP mailbox command scsi: lpfc: Fix DMA virtual address ptr assignment in bsg scsi: lpfc: Fix illegal memory access on Abort IOCBs scsi: blk-mq: Fix build warning when making htmldocs
2021-05-08Merge tag 'kbuild-v5.13-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull more Kbuild updates from Masahiro Yamada: - Convert sh and sparc to use generic shell scripts to generate the syscall headers - refactor .gitignore files - Update kernel/config_data.gz only when the content of the .config is really changed, which avoids the unneeded re-link of vmlinux - move "remove stale files" workarounds to scripts/remove-stale-files - suppress unused-but-set-variable warnings by default for Clang as well - fix locale setting LANG=C to LC_ALL=C - improve 'make distclean' - always keep intermediate objects from scripts/link-vmlinux.sh - move IF_ENABLED out of <linux/kconfig.h> to make it self-contained - misc cleanups * tag 'kbuild-v5.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (25 commits) linux/kconfig.h: replace IF_ENABLED() with PTR_IF() in <linux/kernel.h> kbuild: Don't remove link-vmlinux temporary files on exit/signal kbuild: remove the unneeded comments for external module builds kbuild: make distclean remove tag files in sub-directories kbuild: make distclean work against $(objtree) instead of $(srctree) kbuild: refactor modname-multi by using suffix-search kbuild: refactor fdtoverlay rule kbuild: parameterize the .o part of suffix-search arch: use cross_compiling to check whether it is a cross build or not kbuild: remove ARCH=sh64 support from top Makefile .gitignore: prefix local generated files with a slash kbuild: replace LANG=C with LC_ALL=C Makefile: Move -Wno-unused-but-set-variable out of GCC only block kbuild: add a script to remove stale generated files kbuild: update config_data.gz only when the content of .config is changed .gitignore: ignore only top-level modules.builtin .gitignore: move tags and TAGS close to other tag files kernel/.gitgnore: remove stale timeconst.h and hz.bc usr/include: refactor .gitignore genksyms: fix stale comment ...
2021-05-08Merge tag 'net-5.13-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net Pull networking fixes from Jakub Kicinski: "Networking fixes for 5.13-rc1, including fixes from bpf, can and netfilter trees. Self-contained fixes, nothing risky. Current release - new code bugs: - dsa: ksz: fix a few bugs found by static-checker in the new driver - stmmac: fix frame preemption handshake not triggering after interface restart Previous releases - regressions: - make nla_strcmp handle more then one trailing null character - fix stack OOB reads while fragmenting IPv4 packets in openvswitch and net/sched - sctp: do asoc update earlier in sctp_sf_do_dupcook_a - sctp: delay auto_asconf init until binding the first addr - stmmac: clear receive all(RA) bit when promiscuous mode is off - can: mcp251x: fix resume from sleep before interface was brought up Previous releases - always broken: - bpf: fix leakage of uninitialized bpf stack under speculation - bpf: fix masking negation logic upon negative dst register - netfilter: don't assume that skb_header_pointer() will never fail - only allow init netns to set default tcp cong to a restricted algo - xsk: fix xp_aligned_validate_desc() when len == chunk_size to avoid false positive errors - ethtool: fix missing NLM_F_MULTI flag when dumping - can: m_can: m_can_tx_work_queue(): fix tx_skb race condition - sctp: fix a SCTP_MIB_CURRESTAB leak in sctp_sf_do_dupcook_b - bridge: fix NULL-deref caused by a races between assigning rx_handler_data and setting the IFF_BRIDGE_PORT bit Latecomer: - seg6: add counters support for SRv6 Behaviors" * tag 'net-5.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (73 commits) atm: firestream: Use fallthrough pseudo-keyword net: stmmac: Do not enable RX FIFO overflow interrupts mptcp: fix splat when closing unaccepted socket i40e: Remove LLDP frame filters i40e: Fix PHY type identifiers for 2.5G and 5G adapters i40e: fix the restart auto-negotiation after FEC modified i40e: Fix use-after-free in i40e_client_subtask() i40e: fix broken XDP support netfilter: nftables: avoid potential overflows on 32bit arches netfilter: nftables: avoid overflows in nft_hash_buckets() tcp: Specify cmsgbuf is user pointer for receive zerocopy. mlxsw: spectrum_mr: Update egress RIF list before route's action net: ipa: fix inter-EE IRQ register definitions can: m_can: m_can_tx_work_queue(): fix tx_skb race condition can: mcp251x: fix resume from sleep before interface was brought up can: mcp251xfd: mcp251xfd_probe(): add missing can_rx_offload_del() in error path can: mcp251xfd: mcp251xfd_probe(): fix an error pointer dereference in probe netfilter: nftables: Fix a memleak from userdata error path in new objects netfilter: remove BUG_ON() after skb_header_pointer() netfilter: nfnetlink_osf: Fix a missing skb_header_pointer() NULL check ...
2021-05-09linux/kconfig.h: replace IF_ENABLED() with PTR_IF() in <linux/kernel.h>Masahiro Yamada
<linux/kconfig.h> is included from all the kernel-space source files, including C, assembly, linker scripts. It is intended to contain a minimal set of macros to evaluate CONFIG options. IF_ENABLED() is an intruder here because (x ? y : z) is C code, which should not be included from assembly files or linker scripts. Also, <linux/kconfig.h> is no longer self-contained because NULL is defined in <linux/stddef.h>. Move IF_ENABLED() out to <linux/kernel.h> as PTR_IF(). PTF_IF() takes the general boolean expression instead of a CONFIG option so that it fits better in <linux/kernel.h>. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org>
2021-05-07Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nfJakub Kicinski
Pablo Neira Ayuso says: ==================== Netfilter fixes for net 1) Add SECMARK revision 1 to fix incorrect layout that prevents from remove rule with this target, from Phil Sutter. 2) Fix pernet exit path spat in arptables, from Florian Westphal. 3) Missing rcu_read_unlock() for unknown nfnetlink callbacks, reported by syzbot, from Eric Dumazet. 4) Missing check for skb_header_pointer() NULL pointer in nfnetlink_osf. 5) Remove BUG_ON() after skb_header_pointer() from packet path in several conntrack helper and the TCP tracker. 6) Fix memleak in the new object error path of userdata. 7) Avoid overflows in nft_hash_buckets(), reported by syzbot, also from Eric. 8) Avoid overflows in 32bit arches, from Eric. * git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf: netfilter: nftables: avoid potential overflows on 32bit arches netfilter: nftables: avoid overflows in nft_hash_buckets() netfilter: nftables: Fix a memleak from userdata error path in new objects netfilter: remove BUG_ON() after skb_header_pointer() netfilter: nfnetlink_osf: Fix a missing skb_header_pointer() NULL check netfilter: nfnetlink: add a missing rcu_read_unlock() netfilter: arptables: use pernet ops struct during unregister netfilter: xt_SECMARK: add new revision to fix structure layout ==================== Link: https://lore.kernel.org/r/20210507174739.1850-1-pablo@netfilter.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-05-07Merge tag 'tag-chrome-platform-for-v5.13' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/chrome-platform/linux Pull chrome platform updates from Benson Leung: "cros_ec_typec: - Changes around DP mode check, hard reset, tracking port change. cros_ec misc: - wilco_ec: Convert stream-like files from nonseekable to stream open - cros_usbpd_notify: Listen to EC_HSOT_EVENT_USB_MUX host event - fix format warning in cros_ec_typec" * tag 'tag-chrome-platform-for-v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/chrome-platform/linux: platform/chrome: cros_ec_lpc: Use DEFINE_MUTEX() for mutex lock platform/chrome: cros_usbpd_notify: Listen to EC_HOST_EVENT_USB_MUX host event platform/chrome: cros_ec_typec: Add DP mode check platform/chrome: cros_ec_typec: Handle hard reset platform/chrome: cros_ec: Add Type C hard reset platform/chrome: cros_ec_typec: Track port role platform/chrome: cros_ec_typec: fix clang -Wformat warning platform/chrome: cros_ec_typec: Check for device within remove function platform/chrome: wilco_ec: convert stream-like files from nonseekable_open -> stream_open
2021-05-07Merge tag 'block-5.13-2021-05-07' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block fixes from Jens Axboe: - dasd spelling fixes (Bhaskar) - Limit bio max size on multi-page bvecs to the hardware limit, to avoid overly large bio's (and hence latencies). Originally queued for the merge window, but needed a fix and was dropped from the initial pull (Changheun) - NVMe pull request (Christoph): - reset the bdev to ns head when failover (Daniel Wagner) - remove unsupported command noise (Keith Busch) - misc passthrough improvements (Kanchan Joshi) - fix controller ioctl through ns_head (Minwoo Im) - fix controller timeouts during reset (Tao Chiu) - rnbd fixes/cleanups (Gioh, Md, Dima) - Fix iov_iter re-expansion (yangerkun) * tag 'block-5.13-2021-05-07' of git://git.kernel.dk/linux-block: block: reexpand iov_iter after read/write nvmet: remove unsupported command noise nvme-multipath: reset bdev to ns head when failover nvme-pci: fix controller reset hang when racing with nvme_timeout nvme: move the fabrics queue ready check routines to core nvme: avoid memset for passthrough requests nvme: add nvme_get_ns helper nvme: fix controller ioctl through ns_head bio: limit bio max size RDMA/rtrs: fix uninitialized symbol 'cnt' s390: dasd: Mundane spelling fixes block/rnbd: Remove all likely and unlikely block/rnbd-clt: Check the return value of the function rtrs_clt_query block/rnbd: Fix style issues block/rnbd-clt: Change queue_depth type in rnbd_clt_session to size_t
2021-05-07Merge tag 'nfs-for-5.13-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfsLinus Torvalds
Pull NFS client updates from Trond Myklebust: "Highlights include: Stable fixes: - Add validation of the UDP retrans parameter to prevent shift out-of-bounds - Don't discard pNFS layout segments that are marked for return Bugfixes: - Fix a NULL dereference crash in xprt_complete_bc_request() when the NFSv4.1 server misbehaves. - Fix the handling of NFS READDIR cookie verifiers - Sundry fixes to ensure attribute revalidation works correctly when the server does not return post-op attributes. - nfs4_bitmask_adjust() must not change the server global bitmasks - Fix major timeout handling in the RPC code. - NFSv4.2 fallocate() fixes. - Fix the NFSv4.2 SEEK_HOLE/SEEK_DATA end-of-file handling - Copy offload attribute revalidation fixes - Fix an incorrect filehandle size check in the pNFS flexfiles driver - Fix several RDMA transport setup/teardown races - Fix several RDMA queue wrapping issues - Fix a misplaced memory read barrier in sunrpc's call_decode() Features: - Micro optimisation of the TCP transmission queue using TCP_CORK - statx() performance improvements by further splitting up the tracking of invalid cached file metadata. - Support the NFSv4.2 'change_attr_type' attribute and use it to optimise handling of change attribute updates" * tag 'nfs-for-5.13-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (85 commits) xprtrdma: Fix a NULL dereference in frwr_unmap_sync() sunrpc: Fix misplaced barrier in call_decode NFSv4.2: Remove ifdef CONFIG_NFSD from NFSv4.2 client SSC code. xprtrdma: Move fr_mr field to struct rpcrdma_mr xprtrdma: Move the Work Request union to struct rpcrdma_mr xprtrdma: Move fr_linv_done field to struct rpcrdma_mr xprtrdma: Move cqe to struct rpcrdma_mr xprtrdma: Move fr_cid to struct rpcrdma_mr xprtrdma: Remove the RPC/RDMA QP event handler xprtrdma: Don't display r_xprt memory addresses in tracepoints xprtrdma: Add an rpcrdma_mr_completion_class xprtrdma: Add tracepoints showing FastReg WRs and remote invalidation xprtrdma: Avoid Send Queue wrapping xprtrdma: Do not wake RPC consumer on a failed LocalInv xprtrdma: Do not recycle MR after FastReg/LocalInv flushes xprtrdma: Clarify use of barrier in frwr_wc_localinv_done() xprtrdma: Rename frwr_release_mr() xprtrdma: rpcrdma_mr_pop() already does list_del_init() xprtrdma: Delete rpcrdma_recv_buffer_put() xprtrdma: Fix cwnd update ordering ...
2021-05-07Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge yet more updates from Andrew Morton: "This is everything else from -mm for this merge window. 90 patches. Subsystems affected by this patch series: mm (cleanups and slub), alpha, procfs, sysctl, misc, core-kernel, bitmap, lib, compat, checkpatch, epoll, isofs, nilfs2, hpfs, exit, fork, kexec, gcov, panic, delayacct, gdb, resource, selftests, async, initramfs, ipc, drivers/char, and spelling" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (90 commits) mm: fix typos in comments mm: fix typos in comments treewide: remove editor modelines and cruft ipc/sem.c: spelling fix fs: fat: fix spelling typo of values kernel/sys.c: fix typo kernel/up.c: fix typo kernel/user_namespace.c: fix typos kernel/umh.c: fix some spelling mistakes include/linux/pgtable.h: few spelling fixes mm/slab.c: fix spelling mistake "disired" -> "desired" scripts/spelling.txt: add "overflw" scripts/spelling.txt: Add "diabled" typo scripts/spelling.txt: add "overlfow" arm: print alloc free paths for address in registers mm/vmalloc: remove vwrite() mm: remove xlate_dev_kmem_ptr() drivers/char: remove /dev/kmem for good mm: fix some typos and code style problems ipc/sem.c: mundane typo fixes ...
2021-05-07mm: fix typos in commentsIngo Molnar
Fix ~94 single-word typos in locking code comments, plus a few very obvious grammar mistakes. Link: https://lkml.kernel.org/r/20210322212624.GA1963421@gmail.com Link: https://lore.kernel.org/r/20210322205203.GB1959563@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Randy Dunlap <rdunlap@infradead.org> Cc: Bhaskar Chowdhury <unixbhaskar@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-07treewide: remove editor modelines and cruftMasahiro Yamada
The section "19) Editor modelines and other cruft" in Documentation/process/coding-style.rst clearly says, "Do not include any of these in source files." I recently receive a patch to explicitly add a new one. Let's do treewide cleanups, otherwise some people follow the existing code and attempt to upstream their favoriate editor setups. It is even nicer if scripts/checkpatch.pl can check it. If we like to impose coding style in an editor-independent manner, I think editorconfig (patch [1]) is a saner solution. [1] https://lore.kernel.org/lkml/20200703073143.423557-1-danny@kdrag0n.dev/ Link: https://lkml.kernel.org/r/20210324054457.1477489-1-masahiroy@kernel.org Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Reviewed-by: Miguel Ojeda <ojeda@kernel.org> [auxdisplay] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-07include/linux/pgtable.h: few spelling fixesBhaskar Chowdhury
Few spelling fixes throughout the file. Link: https://lkml.kernel.org/r/20210318201404.6380-1-unixbhaskar@gmail.com Signed-off-by: Bhaskar Chowdhury <unixbhaskar@gmail.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-07mm/vmalloc: remove vwrite()David Hildenbrand
The last user (/dev/kmem) is gone. Let's drop it. Link: https://lkml.kernel.org/r/20210324102351.6932-4-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Hillf Danton <hdanton@sina.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Minchan Kim <minchan@kernel.org> Cc: huang ying <huang.ying.caritas@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-07mm: remove xlate_dev_kmem_ptr()David Hildenbrand
Since /dev/kmem has been removed, let's remove the xlate_dev_kmem_ptr() leftovers. Link: https://lkml.kernel.org/r/20210324102351.6932-3-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Brian Cain <bcain@codeaurora.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Helge Deller <deller@gmx.de> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Rich Felker <dalias@libc.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Arnd Bergmann <arnd@arndb.de> Cc: David Hildenbrand <david@redhat.com> Cc: Krzysztof Kozlowski <krzk@kernel.org> Cc: Mikulas Patocka <mpatocka@redhat.com> Cc: Luc Van Oostenryck <luc.vanoostenryck@gmail.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Palmer Dabbelt <palmerdabbelt@google.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Niklas Schnelle <schnelle@linux.ibm.com> Cc: Pierre Morel <pmorel@linux.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-07drivers/char: remove /dev/kmem for goodDavid Hildenbrand
Patch series "drivers/char: remove /dev/kmem for good". Exploring /dev/kmem and /dev/mem in the context of memory hot(un)plug and memory ballooning, I started questioning the existence of /dev/kmem. Comparing it with the /proc/kcore implementation, it does not seem to be able to deal with things like a) Pages unmapped from the direct mapping (e.g., to be used by secretmem) -> kern_addr_valid(). virt_addr_valid() is not sufficient. b) Special cases like gart aperture memory that is not to be touched -> mem_pfn_is_ram() Unless I am missing something, it's at least broken in some cases and might fault/crash the machine. Looks like its existence has been questioned before in 2005 and 2010 [1], after ~11 additional years, it might make sense to revive the discussion. CONFIG_DEVKMEM is only enabled in a single defconfig (on purpose or by mistake?). All distributions disable it: in Ubuntu it has been disabled for more than 10 years, in Debian since 2.6.31, in Fedora at least starting with FC3, in RHEL starting with RHEL4, in SUSE starting from 15sp2, and OpenSUSE has it disabled as well. 1) /dev/kmem was popular for rootkits [2] before it got disabled basically everywhere. Ubuntu documents [3] "There is no modern user of /dev/kmem any more beyond attackers using it to load kernel rootkits.". RHEL documents in a BZ [5] "it served no practical purpose other than to serve as a potential security problem or to enable binary module drivers to access structures/functions they shouldn't be touching" 2) /proc/kcore is a decent interface to have a controlled way to read kernel memory for debugging puposes. (will need some extensions to deal with memory offlining/unplug, memory ballooning, and poisoned pages, though) 3) It might be useful for corner case debugging [1]. KDB/KGDB might be a better fit, especially, to write random memory; harder to shoot yourself into the foot. 4) "Kernel Memory Editor" [4] hasn't seen any updates since 2000 and seems to be incompatible with 64bit [1]. For educational purposes, /proc/kcore might be used to monitor value updates -- or older kernels can be used. 5) It's broken on arm64, and therefore, completely disabled there. Looks like it's essentially unused and has been replaced by better suited interfaces for individual tasks (/proc/kcore, KDB/KGDB). Let's just remove it. [1] https://lwn.net/Articles/147901/ [2] https://www.linuxjournal.com/article/10505 [3] https://wiki.ubuntu.com/Security/Features#A.2Fdev.2Fkmem_disabled [4] https://sourceforge.net/projects/kme/ [5] https://bugzilla.redhat.com/show_bug.cgi?id=154796 Link: https://lkml.kernel.org/r/20210324102351.6932-1-david@redhat.com Link: https://lkml.kernel.org/r/20210324102351.6932-2-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Alexander A. Klimov" <grandmaster@al2klimov.de> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com> Cc: Andrew Lunn <andrew@lunn.ch> Cc: Andrey Zhizhikin <andrey.zhizhikin@leica-geosystems.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Brian Cain <bcain@codeaurora.org> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Chris Zankel <chris@zankel.net> Cc: Corentin Labbe <clabbe@baylibre.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Greentime Hu <green.hu@gmail.com> Cc: Gregory Clement <gregory.clement@bootlin.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Hillf Danton <hdanton@sina.com> Cc: huang ying <huang.ying.caritas@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: James Troup <james.troup@canonical.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Jonas Bonn <jonas@southpole.se> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kairui Song <kasong@redhat.com> Cc: Krzysztof Kozlowski <krzk@kernel.org> Cc: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> Cc: Liviu Dudau <liviu.dudau@arm.com> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: Luc Van Oostenryck <luc.vanoostenryck@gmail.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Mike Rapoport <rppt@kernel.org> Cc: Mikulas Patocka <mpatocka@redhat.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Niklas Schnelle <schnelle@linux.ibm.com> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com> Cc: openrisc@lists.librecores.org Cc: Palmer Dabbelt <palmerdabbelt@google.com> Cc: Paul Mackerras <paulus@samba.org> Cc: "Pavel Machek (CIP)" <pavel@denx.de> Cc: Pavel Machek <pavel@ucw.cz> Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org> Cc: Pierre Morel <pmorel@linux.ibm.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Richard Henderson <rth@twiddle.net> Cc: Rich Felker <dalias@libc.org> Cc: Robert Richter <rric@kernel.org> Cc: Rob Herring <robh@kernel.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com> Cc: sparclinux@vger.kernel.org Cc: Stafford Horne <shorne@gmail.com> Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sudeep Holla <sudeep.holla@arm.com> Cc: Theodore Dubois <tblodt@icloud.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: William Cohen <wcohen@redhat.com> Cc: Xiaoming Ni <nixiaoming@huawei.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>