linux-stable.git/drivers/s390/block, branch linux-3.16.y

s390/dasd: fix endless loop after read unit address configuration

2019-11-22T15:57:10+00:00

commit 41995342b40c418a47603e1321256d2c4a2ed0fb upstream.

After getting a storage server event that causes the DASD device driver
to update its unit address configuration during a device shutdown there is
the possibility of an endless loop in the device driver.

In the system log there will be ongoing DASD error messages with RC: -19.

The reason is that the loop starting the ruac request only terminates when
the retry counter is decreased to 0. But in the sleep_on function there are
early exit paths that do not decrease the retry counter.

Prevent an endless loop by handling those cases separately.

Remove the unnecessary do..while loop since the sleep_on function takes
care of retries by itself.

Fixes: 8e09f21574ea ("[S390] dasd: add hyper PAV support to DASD device driver, part 1")
Signed-off-by: Stefan Haberland 
Reviewed-by: Jan Hoeppner 
Signed-off-by: Jens Axboe 
Signed-off-by: Ben Hutchings

s390/dasd: fix using offset into zero size array error

2019-05-02T20:41:31+00:00

commit 4a8ef6999bce998fa5813023a9a6b56eea329dba upstream.

Dan Carpenter reported the following:

The patch 52898025cf7d: "[S390] dasd: security and PSF update patch
for EMC CKD ioctl" from Mar 8, 2010, leads to the following static
checker warning:

	drivers/s390/block/dasd_eckd.c:4486 dasd_symm_io()
	error: using offset into zero size array 'psf_data[]'

drivers/s390/block/dasd_eckd.c
  4458          /* Copy parms from caller */
  4459          rc = -EFAULT;
  4460          if (copy_from_user(&usrparm, argp, sizeof(usrparm)))
                                    ^^^^^^^
The user can specify any "usrparm.psf_data_len".  They choose zero by
mistake.

  4461                  goto out;
  4462          if (is_compat_task()) {
  4463                  /* Make sure pointers are sane even on 31 bit. */
  4464                  rc = -EINVAL;
  4465                  if ((usrparm.psf_data >> 32) != 0)
  4466                          goto out;
  4467                  if ((usrparm.rssd_result >> 32) != 0)
  4468                          goto out;
  4469                  usrparm.psf_data &= 0x7fffffffULL;
  4470                  usrparm.rssd_result &= 0x7fffffffULL;
  4471          }
  4472          /* alloc I/O data area */
  4473          psf_data = kzalloc(usrparm.psf_data_len, GFP_KERNEL
  			   				 | GFP_DMA);
  4474          rssd_result = kzalloc(usrparm.rssd_result_len, GFP_KERNEL
							       | GFP_DMA);
  4475          if (!psf_data || !rssd_result) {

kzalloc() returns a ZERO_SIZE_PTR (0x16).

  4476                  rc = -ENOMEM;
  4477                  goto out_free;
  4478          }
  4479
  4480          /* get syscall header from user space */
  4481          rc = -EFAULT;
  4482          if (copy_from_user(psf_data,
  4483                             (void __user *)(unsigned long)
  				   	 		 usrparm.psf_data,
  4484                             usrparm.psf_data_len))

That all works great.

  4485                  goto out_free;
  4486          psf0 = psf_data[0];
  4487          psf1 = psf_data[1];

But now we're assuming that "->psf_data_len" was at least 2 bytes.

Fix this by checking the user specified length psf_data_len.

Fixes: 52898025cf7d ("[S390] dasd: security and PSF update patch for EMC CKD ioctl")
Reported-by: Dan Carpenter 
Signed-off-by: Stefan Haberland 
Signed-off-by: Martin Schwidefsky 
Signed-off-by: Ben Hutchings

s390/dasd: Restore a necessary cast

2019-02-11T17:53:13+00:00

Commit c3925a3da617 "s390/dasd: fix IO error for newly defined
devices" removed a cast of dasd_device::private which was not
necessary in the upstream code.  However, in 3.16 the type of
dasd_device::private is char *, so the cast is still needed.

Reported-by: kbuild test robot 
Signed-off-by: Ben Hutchings

s390/dasd: fix IO error for newly defined devices

2018-10-21T07:45:36+00:00

commit 5d27a2bf6e14f5c7d1033ad1e993fcd0eba43e83 upstream.

When a new CKD storage volume is defined at the storage server, Linux
may be relying on outdated information about that volume, which leads to
the following errors:

1. Command Reject Errors for minidisk on z/VM:

dasd-eckd.b3193d: 0.0.XXXX: An error occurred in the DASD device driver,
		  reason=09
dasd(eckd): I/O status report for device 0.0.XXXX:
dasd(eckd): in req: 00000000XXXXXXXX CC:00 FC:04 AC:00 SC:17 DS:02 CS:00
	    RC:0
dasd(eckd): device 0.0.2046: Failing CCW: 00000000XXXXXXXX
dasd(eckd): Sense(hex)  0- 7: 80 00 00 00 00 00 00 00
dasd(eckd): Sense(hex)  8-15: 00 00 00 00 00 00 00 00
dasd(eckd): Sense(hex) 16-23: 00 00 00 00 e1 00 0f 00
dasd(eckd): Sense(hex) 24-31: 00 00 40 e2 00 00 00 00
dasd(eckd): 24 Byte: 0 MSG 0, no MSGb to SYSOP

2. Equipment Check errors on LPAR or for dedicated devices on z/VM:

dasd(eckd): I/O status report for device 0.0.XXXX:
dasd(eckd): in req: 00000000XXXXXXXX CC:00 FC:04 AC:00 SC:17 DS:0E CS:40
	    fcxs:01 schxs:00 RC:0
dasd(eckd): device 0.0.9713: Failing TCW: 00000000XXXXXXXX
dasd(eckd): Sense(hex)  0- 7: 10 00 00 00 13 58 4d 0f
dasd(eckd): Sense(hex)  8-15: 67 00 00 00 00 00 00 04
dasd(eckd): Sense(hex) 16-23: e5 18 05 33 97 01 0f 0f
dasd(eckd): Sense(hex) 24-31: 00 00 40 e2 00 04 58 0d
dasd(eckd): 24 Byte: 0 MSG f, no MSGb to SYSOP

Fix this problem by using the up-to-date information provided during
online processing via the device specific SNEQ to detect the case of
outdated LCU data. If there is a difference, perform a re-read of that
data.

Reviewed-by: Jan Hoeppner 
Signed-off-by: Stefan Haberland 
Signed-off-by: Martin Schwidefsky 
[bwh: Backported to 3.16:
 - Move up assignment of "private"
 - Adjust context]
Signed-off-by: Ben Hutchings

s390/dasd: fix hanging device after clear subchannel

2016-11-20T01:17:08+00:00

commit 9ba333dc55cbb9523553df973adb3024d223e905 upstream.

When a device is in a status where CIO has killed all I/O by itself the
interrupt for a clear request may not contain an irb to determine the
clear function. Instead it contains an error pointer -EIO.
This was ignored by the DASD int_handler leading to a hanging device
waiting for a clear interrupt.

Handle -EIO error pointer correctly for requests that are clear pending and
treat the clear as successful.

Signed-off-by: Stefan Haberland 
Reviewed-by: Sebastian Ott 
Signed-off-by: Martin Schwidefsky 
Signed-off-by: Ben Hutchings

s390/scm_blk: fix deadlock for requests != REQ_TYPE_FS

2016-06-15T20:29:22+00:00

commit b707c65ae70e24c47a0ce4a7279224ce8f0ffb7f upstream.

When we refuse a non REQ_TYPE_FS request in the build request function
we already hold the queue lock. Thus we must not call blk_end_request_all
but __blk_end_request_all.

Reported-by: Peter Oberparleiter 
Fixes: de9587a ('s390/scm_blk: fix endless loop for requests != REQ_TYPE_FS')
Signed-off-by: Sebastian Ott 
Signed-off-by: Martin Schwidefsky 
Signed-off-by: Ben Hutchings

s390/dasd: fix refcount for PAV reassignment

2016-03-04T10:26:38+00:00

commit 9d862ababb609439c5d6987f6d3ddd09e703aa0b upstream.

Add refcount to the DASD device when a summary unit check worker is
scheduled. This prevents that the device is set offline with worker
in place.

Signed-off-by: Stefan Haberland 
Signed-off-by: Martin Schwidefsky 
Signed-off-by: Luis Henriques

s390/dasd: prevent incorrect length error under z/VM after PAV changes

2016-03-04T10:26:38+00:00

commit 020bf042e5b397479c1174081b935d0ff15d1a64 upstream.

The channel checks the specified length and the provided amount of
data for CCWs and provides an incorrect length error if the size does
not match. Under z/VM with simulation activated the length may get
changed. Having the suppress length indication bit set is stated as
good CCW coding practice and avoids errors under z/VM.

Signed-off-by: Stefan Haberland 
Signed-off-by: Martin Schwidefsky 
Signed-off-by: Luis Henriques

s390: avoid format strings leaking into names

2014-06-11T08:13:27+00:00

This makes sure format strings can't accidentally leak into kernel
interface names.

Signed-off-by: Kees Cook 
Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

2014-04-08T19:02:28+00:00

Pull second set of s390 patches from Martin Schwidefsky:
 "The second part of Heikos uaccess rework, the page table walker for
  uaccess is now a thing of the past (yay!)

  The code change to fix the theoretical TLB flush problem allows us to
  add a TLB flush optimization for zEC12, this machine has new
  instructions that allow to do CPU local TLB flushes for single pages
  and for all pages of a specific address space.

  Plus the usual bug fixing and some more cleanup"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/uaccess: rework uaccess code - fix locking issues
  s390/mm,tlb: optimize TLB flushing for zEC12
  s390/mm,tlb: safeguard against speculative TLB creation
  s390/irq: Use defines for external interruption codes
  s390/irq: Add defines for external interruption codes
  s390/sclp: add timeout for queued requests
  kvm/s390: also set guest pages back to stable on kexec/kdump
  lcs: Add missing destroy_timer_on_stack()
  s390/tape: Add missing destroy_timer_on_stack()
  s390/tape: Use del_timer_sync()
  s390/3270: fix crash with multiple reset device requests
  s390/bitops,atomic: add missing memory barriers
  s390/zcrypt: add length check for aligned data to avoid overflow in msg-type 6