linux-toradex.git/drivers/block/xen-blkfront.c, branch v5.17-rc4

Merge tag 'for-5.17/block-2022-01-11' of git://git.kernel.dk/linux-block

2022-01-12T18:26:52+00:00

Pull block updates from Jens Axboe:

 - Unify where the struct request handling code is located in the blk-mq
   code (Christoph)

 - Header cleanups (Christoph)

 - Clean up the io_context handling code (Christoph, me)

 - Get rid of ->rq_disk in struct request (Christoph)

 - Error handling fix for add_disk() (Christoph)

 - request allocation cleanusp (Christoph)

 - Documentation updates (Eric, Matthew)

 - Remove trivial crypto unregister helper (Eric)

 - Reduce shared tag overhead (John)

 - Reduce poll_stats memory overhead (me)

 - Known indirect function call for dio (me)

 - Use atomic references for struct request (me)

 - Support request list issue for block and NVMe (me)

 - Improve queue dispatch pinning (Ming)

 - Improve the direct list issue code (Keith)

 - BFQ improvements (Jan)

 - Direct completion helper and use it in mmc block (Sebastian)

 - Use raw spinlock for the blktrace code (Wander)

 - fsync error handling fix (Ye)

 - Various fixes and cleanups (Lukas, Randy, Yang, Tetsuo, Ming, me)

* tag 'for-5.17/block-2022-01-11' of git://git.kernel.dk/linux-block: (132 commits)
  MAINTAINERS: add entries for block layer documentation
  docs: block: remove queue-sysfs.rst
  docs: sysfs-block: document virt_boundary_mask
  docs: sysfs-block: document stable_writes
  docs: sysfs-block: fill in missing documentation from queue-sysfs.rst
  docs: sysfs-block: add contact for nomerges
  docs: sysfs-block: sort alphabetically
  docs: sysfs-block: move to stable directory
  block: don't protect submit_bio_checks by q_usage_counter
  block: fix old-style declaration
  nvme-pci: fix queue_rqs list splitting
  block: introduce rq_list_move
  block: introduce rq_list_for_each_safe macro
  block: move rq_list macros to blk-mq.h
  block: drop needless assignment in set_task_ioprio()
  block: remove unnecessary trailing '\'
  bio.h: fix kernel-doc warnings
  block: check minor range in device_add_disk()
  block: use "unsigned long" for blk_validate_block_size().
  block: fix error unwinding in device_add_disk
  ...

xen/blkfront: harden blkfront against event channel storms

2021-12-16T07:24:08+00:00

The Xen blkfront driver is still vulnerable for an attack via excessive
number of events sent by the backend. Fix that by using lateeoi event
channels.

This is part of XSA-391

Signed-off-by: Juergen Gross 
Reviewed-by: Jan Beulich

block: remove GENHD_FL_CD

2021-11-29T13:35:21+00:00

GENHD_FL_CD marks a gendisk as a vaguely CD-ROM like device.
Besides being used internally inside of sunvdc.c an xen-blkfront it
is used by xen-blkback as a hint to claim a device exported to a
guest is a CD-ROM like device.  Just check for disk->cdi instead
which is the right indicator for "real" CD-ROM or DVD drivers.  This
will miss the paravirtualized guest drivers, but those make little
sense to report anyway.

Signed-off-by: Christoph Hellwig 
Link: https://lore.kernel.org/r/20211122130625.1136848-4-hch@lst.de
Signed-off-by: Jens Axboe

xen-blkfront: add error handling support for add_disk()

2021-10-21T15:00:56+00:00

We never checked for errors on device_add_disk() as this function
returned void. Now that this is fixed, use the shiny new error
handling. The function xlvbd_alloc_gendisk() typically does the
unwinding on error on allocating the disk and creating the tag,
but since all that error handling was stuffed inside
xlvbd_alloc_gendisk() we must repeat the tag free'ing as well.

We set the info->rq to NULL to ensure blkif_free() doesn't crash
on blk_mq_stop_hw_queues() on device_add_disk() error as the queue
will be long gone by then.

Reviewed-by: Juergen Gross 
Signed-off-by: Luis Chamberlain 
Link: https://lore.kernel.org/r/20211015233028.2167651-6-mcgrof@kernel.org
Signed-off-by: Jens Axboe

block: drop unused includes in

2021-10-18T12:17:02+00:00

Drop various include not actually used in genhd.h itself, and
move the remaning includes closer together.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Johannes Thumshirn 
Link: https://lore.kernel.org/r/20210920123328.1399408-15-hch@lst.de
Signed-off-by: Jens Axboe

Merge tag 'for-linus-5.15-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

2021-09-02T20:20:11+00:00

Pull xen updates from Juergen Gross:

 - some small cleanups

 - a fix for a bug when running as Xen PV guest which could result in
   not all memory being transferred in case of a migration of the guest

 - a small series for getting rid of code for supporting very old Xen
   hypervisor versions nobody should be using since many years now

 - a series for hardening the Xen block frontend driver

 - a fix for Xen PV boot code issuing warning messages due to a stray
   preempt_disable() on the non-boot processors

* tag 'for-linus-5.15-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen: remove stray preempt_disable() from PV AP startup code
  xen/pcifront: Removed unnecessary __ref annotation
  x86: xen: platform-pci-unplug: use pr_err() and pr_warn() instead of raw printk()
  drivers/xen/xenbus/xenbus_client.c: fix bugon.cocci warnings
  xen/blkfront: don't trust the backend response data blindly
  xen/blkfront: don't take local copy of a request from the ring page
  xen/blkfront: read response from backend only once
  xen: assume XENFEAT_gnttab_map_avail_bits being set for pv guests
  xen: assume XENFEAT_mmu_pt_update_preserve_ad being set for pv guests
  xen: check required Xen features
  xen: fix setting of max_pfn in shared_info

xen/blkfront: don't trust the backend response data blindly

2021-08-30T10:01:59+00:00

Today blkfront will trust the backend to send only sane response data.
In order to avoid privilege escalations or crashes in case of malicious
backends verify the data to be within expected limits. Especially make
sure that the response always references an outstanding request.

Introduce a new state of the ring BLKIF_STATE_ERROR which will be
switched to in case an inconsistency is being detected. Recovering from
this state is possible only via removing and adding the virtual device
again (e.g. via a suspend/resume cycle).

Make all warning messages issued due to valid error responses rate
limited in order to avoid message floods being triggered by a malicious
backend.

Signed-off-by: Juergen Gross 
Reviewed-by: Jan Beulich 
Acked-by: Roger Pau Monné 
Link: https://lore.kernel.org/r/20210730103854.12681-4-jgross@suse.com
Signed-off-by: Juergen Gross

xen/blkfront: don't take local copy of a request from the ring page

2021-08-30T10:01:55+00:00

In order to avoid a malicious backend being able to influence the local
copy of a request build the request locally first and then copy it to
the ring page instead of doing it the other way round as today.

Signed-off-by: Juergen Gross 
Reviewed-by: Jan Beulich 
Acked-by: Roger Pau Monné 
Link: https://lore.kernel.org/r/20210730103854.12681-3-jgross@suse.com
Signed-off-by: Juergen Gross

xen/blkfront: read response from backend only once

2021-08-30T10:01:53+00:00

In order to avoid problems in case the backend is modifying a response
on the ring page while the frontend has already seen it, just read the
response into a local buffer in one go and then operate on that buffer
only.

Signed-off-by: Juergen Gross 
Reviewed-by: Jan Beulich 
Acked-by: Roger Pau Monné 
Link: https://lore.kernel.org/r/20210730103854.12681-2-jgross@suse.com
Signed-off-by: Juergen Gross

xen-blkfront: Remove redundant assignment to variable err

2021-08-10T02:04:46+00:00

The variable err is being assigned a value that is never read, the
assignment is redundant and can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King 
Reviewed-by: Boris Ostrovsky 
Link: https://lore.kernel.org/r/20210806110601.11386-1-colin.king@canonical.com
Signed-off-by: Jens Axboe