linux-stable.git/drivers/md, branch linux-5.8.y

x86, powerpc: Rename memcpy_mcsafe() to copy_mc_to_{user, kernel}()

2020-11-01T11:45:37+00:00

commit ec6347bb43395cb92126788a1a5b25302543f815 upstream.

In reaction to a proposal to introduce a memcpy_mcsafe_fast()
implementation Linus points out that memcpy_mcsafe() is poorly named
relative to communicating the scope of the interface. Specifically what
addresses are valid to pass as source, destination, and what faults /
exceptions are handled.

Of particular concern is that even though x86 might be able to handle
the semantics of copy_mc_to_user() with its common copy_user_generic()
implementation other archs likely need / want an explicit path for this
case:

  On Fri, May 1, 2020 at 11:28 AM Linus Torvalds  wrote:
  >
  > On Thu, Apr 30, 2020 at 6:21 PM Dan Williams  wrote:
  > >
  > > However now I see that copy_user_generic() works for the wrong reason.
  > > It works because the exception on the source address due to poison
  > > looks no different than a write fault on the user address to the
  > > caller, it's still just a short copy. So it makes copy_to_user() work
  > > for the wrong reason relative to the name.
  >
  > Right.
  >
  > And it won't work that way on other architectures. On x86, we have a
  > generic function that can take faults on either side, and we use it
  > for both cases (and for the "in_user" case too), but that's an
  > artifact of the architecture oddity.
  >
  > In fact, it's probably wrong even on x86 - because it can hide bugs -
  > but writing those things is painful enough that everybody prefers
  > having just one function.

Replace a single top-level memcpy_mcsafe() with either
copy_mc_to_user(), or copy_mc_to_kernel().

Introduce an x86 copy_mc_fragile() name as the rename for the
low-level x86 implementation formerly named memcpy_mcsafe(). It is used
as the slow / careful backend that is supplanted by a fast
copy_mc_generic() in a follow-on patch.

One side-effect of this reorganization is that separating copy_mc_64.S
to its own file means that perf no longer needs to track dependencies
for its memcpy_64.S benchmarks.

 [ bp: Massage a bit. ]

Signed-off-by: Dan Williams 
Signed-off-by: Borislav Petkov 
Reviewed-by: Tony Luck 
Acked-by: Michael Ellerman 
Cc: 
Link: http://lore.kernel.org/r/CAHk-=wjSqtXAqfUJxFtWNwmguFASTgB0dz1dT3V-78Quiezqbg@mail.gmail.com
Link: https://lkml.kernel.org/r/160195561680.2163339.11574962055305783722.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Greg Kroah-Hartman

md/bitmap: fix memory leak of temporary bitmap

2020-10-29T09:08:17+00:00

[ Upstream commit 1383b347a8ae4a69c04ae3746e6cb5c8d38e2585 ]

Callers of get_bitmap_from_slot() are responsible to free the bitmap.

Suggested-by: Guoqing Jiang 
Signed-off-by: Zhao Heming 
Signed-off-by: Song Liu 
Signed-off-by: Sasha Levin

dm: fix bio splitting and its bio completion order for regular IO

2020-10-01T15:36:35+00:00

commit ee1dfad5325ff1cfb2239e564cd411b3bfe8667a upstream.

dm_queue_split() is removed because __split_and_process_bio() _must_
handle splitting bios to ensure proper bio submission and completion
ordering as a bio is split.

Otherwise, multiple recursive calls to ->submit_bio will cause multiple
split bios to be allocated from the same ->bio_split mempool at the same
time. This would result in deadlock in low memory conditions because no
progress could be made (only one bio is available in ->bio_split
mempool).

This fix has been verified to still fix the loss of performance, due
to excess splitting, that commit 120c9257f5f1 provided.

Fixes: 120c9257f5f1 ("Revert "dm: always call blk_queue_split() in dm_process_bio()"")
Cc: stable@vger.kernel.org # 5.0+, requires custom backport due to 5.9 changes
Reported-by: Ming Lei 
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

dm: Call proper helper to determine dax support

2020-09-23T11:00:03+00:00

commit e2ec5128254518cae320d5dc631b71b94160f663 upstream.

DM was calling generic_fsdax_supported() to determine whether a device
referenced in the DM table supports DAX. However this is a helper for "leaf" device drivers so that
they don't have to duplicate common generic checks. High level code
should call dax_supported() helper which that calls into appropriate
helper for the particular device. This problem manifested itself as
kernel messages:

dm-3: error: dax access failed (-95)

when lvm2-testsuite run in cases where a DM device was stacked on top of
another DM device.

Fixes: 7bf7eac8d648 ("dax: Arrange for dax_supported check to span multiple devices")
Cc: 
Tested-by: Adrian Huang 
Signed-off-by: Jan Kara 
Acked-by: Mike Snitzer 
Reported-by: kernel test robot 
Link: https://lore.kernel.org/r/160061715195.13131.5503173247632041975.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams 
Signed-off-by: Greg Kroah-Hartman

dm/dax: Fix table reference counts

2020-09-23T11:00:02+00:00

commit 02186d8897d49b0afd3c80b6cf23437d91024065 upstream.

A recent fix to the dm_dax_supported() flow uncovered a latent bug. When
dm_get_live_table() fails it is still required to drop the
srcu_read_lock(). Without this change the lvm2 test-suite triggers this
warning:

    # lvm2-testsuite --only pvmove-abort-all.sh

    WARNING: lock held when returning to user space!
    5.9.0-rc5+ #251 Tainted: G           OE
    ------------------------------------------------
    lvm/1318 is leaving the kernel with locks still held!
    1 lock held by lvm/1318:
     #0: ffff9372abb5a340 (&md->io_barrier){....}-{0:0}, at: dm_get_live_table+0x5/0xb0 [dm_mod]

...and later on this hang signature:

    INFO: task lvm:1344 blocked for more than 122 seconds.
          Tainted: G           OE     5.9.0-rc5+ #251
    "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
    task:lvm             state:D stack:    0 pid: 1344 ppid:     1 flags:0x00004000
    Call Trace:
     __schedule+0x45f/0xa80
     ? finish_task_switch+0x249/0x2c0
     ? wait_for_completion+0x86/0x110
     schedule+0x5f/0xd0
     schedule_timeout+0x212/0x2a0
     ? __schedule+0x467/0xa80
     ? wait_for_completion+0x86/0x110
     wait_for_completion+0xb0/0x110
     __synchronize_srcu+0xd1/0x160
     ? __bpf_trace_rcu_utilization+0x10/0x10
     __dm_suspend+0x6d/0x210 [dm_mod]
     dm_suspend+0xf6/0x140 [dm_mod]

Fixes: 7bf7eac8d648 ("dax: Arrange for dax_supported check to span multiple devices")
Cc: 
Cc: Jan Kara 
Cc: Alasdair Kergon 
Cc: Mike Snitzer 
Reported-by: Adrian Huang 
Reviewed-by: Ira Weiny 
Tested-by: Adrian Huang 
Link: https://lore.kernel.org/r/160045867590.25663.7548541079217827340.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams 
Signed-off-by: Greg Kroah-Hartman

dm thin metadata: Fix use-after-free in dm_bm_set_read_only

2020-09-09T17:14:32+00:00

commit 3a653b205f29b3f9827a01a0c88bfbcb0d169494 upstream.

The following error ocurred when testing disk online/offline:

[  301.798344] device-mapper: thin: 253:5: aborting current metadata transaction
[  301.848441] device-mapper: thin: 253:5: failed to abort metadata transaction
[  301.849206] Aborting journal on device dm-26-8.
[  301.850489] EXT4-fs error (device dm-26) in __ext4_new_inode:943: Journal has aborted
[  301.851095] EXT4-fs (dm-26): Delayed block allocation failed for inode 398742 at logical offset 181 with max blocks 19 with error 30
[  301.854476] BUG: KASAN: use-after-free in dm_bm_set_read_only+0x3a/0x40 [dm_persistent_data]

Reason is:

 metadata_operation_failed
    abort_transaction
        dm_pool_abort_metadata
	    __create_persistent_data_objects
	        r = __open_or_format_metadata
	        if (r) --> If failed will free pmd->bm but pmd->bm not set NULL
		    dm_block_manager_destroy(pmd->bm);
    set_pool_mode
	dm_pool_metadata_read_only(pool->pmd);
	dm_bm_set_read_only(pmd->bm);  --> use-after-free

Add checks to see if pmd->bm is NULL in dm_bm_set_read_only and
dm_bm_set_read_write functions.  If bm is NULL it means creating the
bm failed and so dm_bm_is_read_only must return true.

Signed-off-by: Ye Bin 
Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

dm thin metadata: Avoid returning cmd->bm wild pointer on error

2020-09-09T17:14:32+00:00

commit 219403d7e56f9b716ad80ab87db85d29547ee73e upstream.

Maybe __create_persistent_data_objects() caller will use PTR_ERR as a
pointer, it will lead to some strange things.

Signed-off-by: Ye Bin 
Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

dm cache metadata: Avoid returning cmd->bm wild pointer on error

2020-09-09T17:14:32+00:00

commit d16ff19e69ab57e08bf908faaacbceaf660249de upstream.

Maybe __create_persistent_data_objects() caller will use PTR_ERR as a
pointer, it will lead to some strange things.

Signed-off-by: Ye Bin 
Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

dm crypt: Initialize crypto wait structures

2020-09-09T17:14:31+00:00

commit 7785a9e4c228db6d01086a52d5685cd7336a08b7 upstream.

Use the DECLARE_CRYPTO_WAIT() macro to properly initialize the crypto
wait structures declared on stack before their use with
crypto_wait_req().

Fixes: 39d13a1ac41d ("dm crypt: reuse eboiv skcipher for IV generation")
Fixes: bbb1658461ac ("dm crypt: Implement Elephant diffuser for Bitlocker compatibility")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal 
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

dm integrity: fix error reporting in bitmap mode after creation

2020-09-09T17:14:31+00:00

commit e27fec66f0a94e35a35548bd0b29ae616e62ec62 upstream.

The dm-integrity target did not report errors in bitmap mode just after
creation. The reason is that the function integrity_recalc didn't clean up
ic->recalc_bitmap as it proceeded with recalculation.

Fix this by updating the bitmap accordingly -- the double shift serves
to rounddown.

Signed-off-by: Mikulas Patocka 
Fixes: 468dfca38b1a ("dm integrity: add a bitmap mode")
Cc: stable@vger.kernel.org # v5.2+
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman