linux-stable.git/drivers/target/target_core_user.c, branch linux-5.8.y

scsi: target: tcmu: Fix warning: 'page' may be used uninitialized

2020-10-29T09:07:48+00:00

[ Upstream commit 61741d8699e1fc764a309ebd20211bb1cb193110 ]

Corrects drivers/target/target_core_user.c:688:6: warning: 'page' may be
used uninitialized.

Link: https://lore.kernel.org/r/20200924001920.43594-1-john.p.donnelly@oracle.com
Fixes: 3c58f737231e ("scsi: target: tcmu: Optimize use of flush_dcache_page")
Cc: Mike Christie 
Acked-by: Mike Christie 
Signed-off-by: John Donnelly 
Signed-off-by: Martin K. Petersen 
Signed-off-by: Sasha Levin

scsi: target: tcmu: Optimize use of flush_dcache_page

2020-09-05T09:24:04+00:00

commit 3c58f737231e2c8cbf543a09d84d8c8e80e05e43 upstream.

(scatter|gather)_data_area() need to flush dcache after writing data to or
before reading data from a page in uio data area.  The two routines are
able to handle data transfer to/from such a page in fragments and flush the
cache after each fragment was copied by calling the wrapper
tcmu_flush_dcache_range().

That means:

1) flush_dcache_page() can be called multiple times for the same page.

2) Calling flush_dcache_page() indirectly using the wrapper does not make
   sense, because each call of the wrapper is for one single page only and
   the calling routine already has the correct page pointer.

Change (scatter|gather)_data_area() such that, instead of calling
tcmu_flush_dcache_range() before/after each memcpy, it now calls
flush_dcache_page() before unmapping a page (when writing is complete for
that page) or after mapping a page (when starting to read the page).

After this change only calls to tcmu_flush_dcache_range() for addresses in
vmalloc'ed command ring are left over.

The patch was tested on ARM with kernel 4.19.118 and 5.7.2

Link: https://lore.kernel.org/r/20200618131632.32748-2-bstroesser@ts.fujitsu.com
Tested-by: JiangYu 
Tested-by: Daniel Meyerholt 
Acked-by: Mike Christie 
Signed-off-by: Bodo Stroesser 
Signed-off-by: Martin K. Petersen 
Signed-off-by: Greg Kroah-Hartman

scsi: target: tcmu: Fix crash on ARM during cmd completion

2020-09-03T09:29:16+00:00

[ Upstream commit 5a0c256d96f020e4771f6fd5524b80f89a2d3132 ]

If tcmu_handle_completions() has to process a padding shorter than
sizeof(struct tcmu_cmd_entry), the current call to
tcmu_flush_dcache_range() with sizeof(struct tcmu_cmd_entry) as length
param is wrong and causes crashes on e.g. ARM, because
tcmu_flush_dcache_range() in this case calls
flush_dcache_page(vmalloc_to_page(start)); with start being an invalid
address above the end of the vmalloc'ed area.

The fix is to use the minimum of remaining ring space and sizeof(struct
tcmu_cmd_entry) as the length param.

The patch was tested on kernel 4.19.118.

See https://bugzilla.kernel.org/show_bug.cgi?id=208045#c10

Link: https://lore.kernel.org/r/20200629093756.8947-1-bstroesser@ts.fujitsu.com
Tested-by: JiangYu 
Acked-by: Mike Christie 
Signed-off-by: Bodo Stroesser 
Signed-off-by: Martin K. Petersen 
Signed-off-by: Sasha Levin

scsi: target: tcmu: Fix crash in tcmu_flush_dcache_range on ARM

2020-08-26T09:49:04+00:00

[ Upstream commit 3145550a7f8b08356c8ff29feaa6c56aca12901d ]

This patch fixes the following crash (see
https://bugzilla.kernel.org/show_bug.cgi?id=208045)

 Process iscsi_trx (pid: 7496, stack limit = 0x0000000010dd111a)
 CPU: 0 PID: 7496 Comm: iscsi_trx Not tainted 4.19.118-0419118-generic
        #202004230533
 Hardware name: Greatwall QingTian DF720/F601, BIOS 601FBE20 Sep 26 2019
 pstate: 80400005 (Nzcv daif +PAN -UAO)
 pc : flush_dcache_page+0x18/0x40
 lr : is_ring_space_avail+0x68/0x2f8 [target_core_user]
 sp : ffff000015123a80
 x29: ffff000015123a80 x28: 0000000000000000
 x27: 0000000000001000 x26: ffff000023ea5000
 x25: ffffcfa25bbe08b8 x24: 0000000000000078
 x23: ffff7e0000000000 x22: ffff000023ea5001
 x21: ffffcfa24b79c000 x20: 0000000000000fff
 x19: ffff7e00008fa940 x18: 0000000000000000
 x17: 0000000000000000 x16: ffff2d047e709138
 x15: 0000000000000000 x14: 0000000000000000
 x13: 0000000000000000 x12: ffff2d047fbd0a40
 x11: 0000000000000000 x10: 0000000000000030
 x9 : 0000000000000000 x8 : ffffc9a254820a00
 x7 : 00000000000013b0 x6 : 000000000000003f
 x5 : 0000000000000040 x4 : ffffcfa25bbe08e8
 x3 : 0000000000001000 x2 : 0000000000000078
 x1 : ffffcfa25bbe08b8 x0 : ffff2d040bc88a18
 Call trace:
  flush_dcache_page+0x18/0x40
  is_ring_space_avail+0x68/0x2f8 [target_core_user]
  queue_cmd_ring+0x1f8/0x680 [target_core_user]
  tcmu_queue_cmd+0xe4/0x158 [target_core_user]
  __target_execute_cmd+0x30/0xf0 [target_core_mod]
  target_execute_cmd+0x294/0x390 [target_core_mod]
  transport_generic_new_cmd+0x1e8/0x358 [target_core_mod]
  transport_handle_cdb_direct+0x50/0xb0 [target_core_mod]
  iscsit_execute_cmd+0x2b4/0x350 [iscsi_target_mod]
  iscsit_sequence_cmd+0xd8/0x1d8 [iscsi_target_mod]
  iscsit_process_scsi_cmd+0xac/0xf8 [iscsi_target_mod]
  iscsit_get_rx_pdu+0x404/0xd00 [iscsi_target_mod]
  iscsi_target_rx_thread+0xb8/0x130 [iscsi_target_mod]
  kthread+0x130/0x138
  ret_from_fork+0x10/0x18
 Code: f9000bf3 aa0003f3 aa1e03e0 d503201f (f9400260)
 ---[ end trace 1e451c73f4266776 ]---

The solution is based on patch:

  "scsi: target: tcmu: Optimize use of flush_dcache_page"

which restricts the use of tcmu_flush_dcache_range() to addresses from
vmalloc'ed areas only.

This patch now replaces the virt_to_page() call in
tcmu_flush_dcache_range() - which is wrong for vmalloced addrs - by
vmalloc_to_page().

The patch was tested on ARM with kernel 4.19.118 and 5.7.2

Link: https://lore.kernel.org/r/20200618131632.32748-3-bstroesser@ts.fujitsu.com
Tested-by: JiangYu 
Tested-by: Daniel Meyerholt 
Acked-by: Mike Christie 
Signed-off-by: Bodo Stroesser 
Signed-off-by: Martin K. Petersen 
Signed-off-by: Sasha Levin

Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

2020-06-13T20:17:49+00:00

Pull more SCSI updates from James Bottomley:
 "This is the set of changes collected since just before the merge
  window opened. It's mostly minor fixes in drivers.

  The one non-driver set is the three optical disk (sr) changes where
  two are error path fixes and one is a helper conversion.

  The big driver change is the hpsa compat_alloc_userspace rework by Al
  so he can kill the remaining user. This has been tested and acked by
  the maintainer"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (21 commits)
  scsi: acornscsi: Fix an error handling path in acornscsi_probe()
  scsi: storvsc: Remove memset before memory freeing in storvsc_suspend()
  scsi: cxlflash: Remove an unnecessary NULL check
  scsi: ibmvscsi: Don't send host info in adapter info MAD after LPM
  scsi: sr: Fix sr_probe() missing deallocate of device minor
  scsi: sr: Fix sr_probe() missing mutex_destroy
  scsi: st: Convert convert get_user_pages() --> pin_user_pages()
  scsi: target: Rename target_setup_cmd_from_cdb() to target_cmd_parse_cdb()
  scsi: target: Fix NULL pointer dereference
  scsi: target: Initialize LUN in transport_init_se_cmd()
  scsi: target: Factor out a new helper, target_cmd_init_cdb()
  scsi: hpsa: hpsa_ioctl(): Tidy up a bit
  scsi: hpsa: Get rid of compat_alloc_user_space()
  scsi: hpsa: Don't bother with vmalloc for BIG_IOCTL_Command_struct
  scsi: hpsa: Lift {BIG_,}IOCTL_Command_struct copy{in,out} into hpsa_ioctl()
  scsi: ufs: Remove redundant urgent_bkop_lvl initialization
  scsi: ufs: Don't update urgent bkops level when toggling auto bkops
  scsi: qedf: Remove redundant initialization of variable rc
  scsi: mpt3sas: Fix memset() in non-RDPQ mode
  scsi: iscsi: Fix reference count leak in iscsi_boot_create_kobj
  ...

Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

2020-06-05T22:11:50+00:00

Pull SCSI updates from James Bottomley:
 :This series consists of the usual driver updates (qla2xxx, ufs, zfcp,
  target, scsi_debug, lpfc, qedi, qedf, hisi_sas, mpt3sas) plus a host
  of other minor updates.

  There are no major core changes in this series apart from a
  refactoring in scsi_lib.c"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (207 commits)
  scsi: ufs: ti-j721e-ufs: Fix unwinding of pm_runtime changes
  scsi: cxgb3i: Fix some leaks in init_act_open()
  scsi: ibmvscsi: Make some functions static
  scsi: iscsi: Fix deadlock on recovery path during GFP_IO reclaim
  scsi: ufs: Fix WriteBooster flush during runtime suspend
  scsi: ufs: Fix index of attributes query for WriteBooster feature
  scsi: ufs: Allow WriteBooster on UFS 2.2 devices
  scsi: ufs: Remove unnecessary memset for dev_info
  scsi: ufs-qcom: Fix scheduling while atomic issue
  scsi: mpt3sas: Fix reply queue count in non RDPQ mode
  scsi: lpfc: Fix lpfc_nodelist leak when processing unsolicited event
  scsi: target: tcmu: Fix a use after free in tcmu_check_expired_queue_cmd()
  scsi: vhost: Notify TCM about the maximum sg entries supported per command
  scsi: qla2xxx: Remove return value from qla_nvme_ls()
  scsi: qla2xxx: Remove an unused function
  scsi: iscsi: Register sysfs for iscsi workqueue
  scsi: scsi_debug: Parser tables and code interaction
  scsi: core: Refactor scsi_mq_setup_tags function
  scsi: core: Fix incorrect usage of shost_for_each_device
  scsi: qla2xxx: Fix endianness annotations in source files
  ...

scsi: target: tcmu: Fix size in calls to tcmu_flush_dcache_range

2020-06-03T01:23:47+00:00

1) If remaining ring space before the end of the ring is smaller then the
   next cmd to write, tcmu writes a padding entry which fills the remaining
   space at the end of the ring.

   Then tcmu calls tcmu_flush_dcache_range() with the size of struct
   tcmu_cmd_entry as data length to flush.  If the space filled by the
   padding was smaller then tcmu_cmd_entry, tcmu_flush_dcache_range() is
   called for an address range reaching behind the end of the vmalloc'ed
   ring.

   tcmu_flush_dcache_range() in a loop calls
   flush_dcache_page(virt_to_page(start)); for every page being part of the
   range. On x86 the line is optimized out by the compiler, as
   flush_dcache_page() is empty on x86.

   But I assume the above can cause trouble on other architectures that
   really have a flush_dcache_page().  For paddings only the header part of
   an entry is relevant due to alignment rules the header always fits in
   the remaining space, if padding is needed.  So tcmu_flush_dcache_range()
   can safely be called with sizeof(entry->hdr) as the length here.

2) After it has written a command to cmd ring, tcmu calls
   tcmu_flush_dcache_range() using the size of a struct tcmu_cmd_entry as
   data length to flush.  But if a command needs many iovecs, the real size
   of the command may be bigger then tcmu_cmd_entry, so a part of the
   written command is not flushed then.

Link: https://lore.kernel.org/r/20200528193108.9085-1-bstroesser@ts.fujitsu.com
Acked-by: Mike Christie 
Signed-off-by: Bodo Stroesser 
Signed-off-by: Martin K. Petersen

scsi: target: tcmu: Fix a use after free in tcmu_check_expired_queue_cmd()

2020-05-26T19:54:39+00:00

The pr_debug() dereferences "cmd" after we already freed it by calling
tcmu_free_cmd(cmd).  The debug printk needs to be done earlier.

Link: https://lore.kernel.org/r/20200523101129.GB98132@mwanda
Fixes: 61fb24822166 ("scsi: target: tcmu: Userspace must not complete queued commands")
Reviewed-by: Mike Christie 
Reviewed-by: David Disseldorp 
Signed-off-by: Dan Carpenter 
Signed-off-by: Martin K. Petersen

scsi: target: tcmu: Userspace must not complete queued commands

2020-05-20T01:33:04+00:00

When tcmu queues a new command - no matter whether in command ring or in
qfull_queue - a cmd_id from IDR udev->commands is assigned to the command.

If userspace sends a wrong command completion containing the cmd_id of a
command on the qfull_queue, tcmu_handle_completions() finds the command in
the IDR and calls tcmu_handle_completion() for it. This might do some nasty
things because commands in qfull_queue do not have a valid dbi list.

To fix this bug, we no longer add queued commands to the idr.  Instead the
cmd_id is assign when a command is written to the command ring.

Due to this change I had to adapt the source code at several places where
up to now an idr_for_each had been done.

[mkp: fix checkpatch warnings]

Link: https://lore.kernel.org/r/20200518164833.12775-1-bstroesser@ts.fujitsu.com
Acked-by: Mike Christie 
Signed-off-by: Bodo Stroesser 
Signed-off-by: Martin K. Petersen

scsi: target: tcmu: Make pgr_support and alua_support attributes writable

2020-05-08T02:39:22+00:00

Currently in tcmu reservation commands are handled by core's pr
implementation (default) or completely rejected (emulate_pr set to 0). We
additionally want to be able to do full reservation handling in
userspace. Therefore we need a way to set TRANSPORT_FLAG_PASSTHROUGH_PGR.

The inverted flag is displayed by attribute pgr_support.  Since we moved
the flag from transport/backend to se_device in the previous commit, we now
can make it changeable per device by allowing to write the attribute.  The
new field transport_flags_changeable in transport/backend is used to reject
writing if not allowed for a backend.

Regarding ALUA we also want to be able to passthrough commands to userspace
in tcmu. Therefore we need TRANSPORT_FLAG_PASSTHROUGH_ALUA to be
changeable, because by setting it we can switch off all ALUA checks in
core. So we also set TRANSPORT_FLAG_PASSTHROUGH_ALUA in tcmu's
transport_flags_changeable.

Of course, ALUA and reservation handling in userspace will work only, if
session/nexus information is sent to userspace along with every
command. This will be object of a patch series announced by Mike Christie.

Link: https://lore.kernel.org/r/20200427150823.15350-5-bstroesser@ts.fujitsu.com
Reviewed-by: Mike Christie 
Signed-off-by: Bodo Stroesser 
Signed-off-by: Martin K. Petersen