linux-stable.git/drivers/infiniband, branch v5.1.2

rdma: fix build errors on s390 and MIPS due to bad ZERO_PAGE use

2019-04-29T16:48:53+00:00

The parameter to ZERO_PAGE() was wrong, but since all architectures
except for MIPS and s390 ignore it, it wasn't noticed until 0-day
reported the build error.

Fixes: 67f269b37f9b ("RDMA/ucontext: Fix regression with disassociate")
Cc: stable@vger.kernel.org
Cc: Andrea Arcangeli 
Cc: Leon Romanovsky 
Cc: Jason Gunthorpe 
Signed-off-by: Linus Torvalds

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma

2019-04-28T17:00:45+00:00

Pull rdma fixes from Jason Gunthorpe:
 "One core bug fix and a few driver ones

   - FRWR memory registration for hfi1/qib didn't work with with some
     iovas causing a NFSoRDMA failure regression due to a fix in the NFS
     side

   - A command flow error in mlx5 allowed user space to send a corrupt
     command (and also smash the kernel stack we've since learned)

   - Fix a regression and some bugs with device hot unplug that was
     discovered while reviewing Andrea's patches

   - hns has a failure if the user asks for certain QP configurations"

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma:
  RDMA/hns: Bugfix for mapping user db
  RDMA/ucontext: Fix regression with disassociate
  RDMA/mlx5: Use rdma_user_map_io for mapping BAR pages
  RDMA/mlx5: Do not allow the user to write to the clock page
  IB/mlx5: Fix scatter to CQE in DCT QP creation
  IB/rdmavt: Fix frwr memory registration

RDMA/hns: Bugfix for mapping user db

2019-04-25T13:40:04+00:00

When the maximum send wr delivered by the user is zero, the qp does not
have a sq.

When allocating the sq db buffer to store the user sq pi pointer and map
it to the kernel mode, max_send_wr is used as the trigger condition, while
the kernel does not consider the max_send_wr trigger condition when
mapmping db. It will cause sq record doorbell map fail and create qp fail.

The failed print information as follows:

 hns3 0000:7d:00.1: Send cmd: tail - 418, opcode - 0x8504, flag - 0x0011, retval - 0x0000
 hns3 0000:7d:00.1: Send cmd: 0xe59dc000 0x00000000 0x00000000 0x00000000 0x00000116 0x0000ffff
 hns3 0000:7d:00.1: sq record doorbell map failed!
 hns3 0000:7d:00.1: Create RC QP failed

Fixes: 0425e3e6e0c7 ("RDMA/hns: Support flush cqe for hip08 in kernel space")
Signed-off-by: Lijun Ou 
Signed-off-by: Jason Gunthorpe

RDMA/ucontext: Fix regression with disassociate

2019-04-24T16:32:25+00:00

When this code was consolidated the intention was that the VMA would
become backed by anonymous zero pages after the zap_vma_pte - however this
very subtly relied on setting the vm_ops = NULL and clearing the VM_SHARED
bits to transform the VMA into an anonymous VMA. Since the vm_ops was
removed this broke.

Now userspace gets a SIGBUS if it touches the vma after disassociation.

Instead of converting the VMA to anonymous provide a fault handler that
puts a zero'd page into the VMA when user-space touches it after
disassociation.

Cc: stable@vger.kernel.org
Suggested-by: Andrea Arcangeli 
Fixes: 5f9794dc94f5 ("RDMA/ucontext: Add a core API for mmaping driver IO memory")
Signed-off-by: Jason Gunthorpe 
Signed-off-by: Leon Romanovsky 
Signed-off-by: Jason Gunthorpe

RDMA/mlx5: Use rdma_user_map_io for mapping BAR pages

2019-04-24T16:06:40+00:00

Since mlx5 supports device disassociate it must use this API for all
BAR page mmaps, otherwise the pages can remain mapped after the device
is unplugged causing a system crash.

Cc: stable@vger.kernel.org
Fixes: 5f9794dc94f5 ("RDMA/ucontext: Add a core API for mmaping driver IO memory")
Signed-off-by: Jason Gunthorpe 
Reviewed-by: Haggai Eran 
Signed-off-by: Leon Romanovsky

RDMA/mlx5: Do not allow the user to write to the clock page

2019-04-24T16:06:24+00:00

The intent of this VMA was to be read-only from user space, but the
VM_MAYWRITE masking was missed, so mprotect could make it writable.

Cc: stable@vger.kernel.org
Fixes: 5c99eaecb1fc ("IB/mlx5: Mmap the HCA's clock info to user-space")
Signed-off-by: Jason Gunthorpe 
Reviewed-by: Haggai Eran 
Signed-off-by: Leon Romanovsky

coredump: fix race condition between mmget_not_zero()/get_task_mm() and core dumping

2019-04-19T16:46:05+00:00

The core dumping code has always run without holding the mmap_sem for
writing, despite that is the only way to ensure that the entire vma
layout will not change from under it.  Only using some signal
serialization on the processes belonging to the mm is not nearly enough.
This was pointed out earlier.  For example in Hugh's post from Jul 2017:

  https://lkml.kernel.org/r/alpine.LSU.2.11.1707191716030.2055@eggly.anvils

  "Not strictly relevant here, but a related note: I was very surprised
   to discover, only quite recently, how handle_mm_fault() may be called
   without down_read(mmap_sem) - when core dumping. That seems a
   misguided optimization to me, which would also be nice to correct"

In particular because the growsdown and growsup can move the
vm_start/vm_end the various loops the core dump does around the vma will
not be consistent if page faults can happen concurrently.

Pretty much all users calling mmget_not_zero()/get_task_mm() and then
taking the mmap_sem had the potential to introduce unexpected side
effects in the core dumping code.

Adding mmap_sem for writing around the ->core_dump invocation is a
viable long term fix, but it requires removing all copy user and page
faults and to replace them with get_dump_page() for all binary formats
which is not suitable as a short term fix.

For the time being this solution manually covers the places that can
confuse the core dump either by altering the vma layout or the vma flags
while it runs.  Once ->core_dump runs under mmap_sem for writing the
function mmget_still_valid() can be dropped.

Allowing mmap_sem protected sections to run in parallel with the
coredump provides some minor parallelism advantage to the swapoff code
(which seems to be safe enough by never mangling any vma field and can
keep doing swapins in parallel to the core dumping) and to some other
corner case.

In order to facilitate the backporting I added "Fixes: 86039bd3b4e6"
however the side effect of this same race condition in /proc/pid/mem
should be reproducible since before 2.6.12-rc2 so I couldn't add any
other "Fixes:" because there's no hash beyond the git genesis commit.

Because find_extend_vma() is the only location outside of the process
context that could modify the "mm" structures under mmap_sem for
reading, by adding the mmget_still_valid() check to it, all other cases
that take the mmap_sem for reading don't need the new check after
mmget_not_zero()/get_task_mm().  The expand_stack() in page fault
context also doesn't need the new check, because all tasks under core
dumping are frozen.

Link: http://lkml.kernel.org/r/20190325224949.11068-1-aarcange@redhat.com
Fixes: 86039bd3b4e6 ("userfaultfd: add new syscall to provide memory externalization")
Signed-off-by: Andrea Arcangeli 
Reported-by: Jann Horn 
Suggested-by: Oleg Nesterov 
Acked-by: Peter Xu 
Reviewed-by: Mike Rapoport 
Reviewed-by: Oleg Nesterov 
Reviewed-by: Jann Horn 
Acked-by: Jason Gunthorpe 
Acked-by: Michal Hocko 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

IB/mlx5: Fix scatter to CQE in DCT QP creation

2019-04-18T06:13:41+00:00

When scatter to CQE is enabled on a DCT QP it corrupts the mailbox command
since it tried to treat it as as QP create mailbox command instead of a
DCT create command.

The corrupted mailbox command causes userspace to malfunction as the
device doesn't create the QP as expected.

A new mlx5 capability is exposed to user-space which ensures that it will
not enable the feature on DCT without this fix in the kernel.

Fixes: 5d6ff1babe78 ("IB/mlx5: Support scatter to CQE for DC transport type")
Signed-off-by: Guy Levi 
Signed-off-by: Leon Romanovsky 
Signed-off-by: Jason Gunthorpe

IB/rdmavt: Fix frwr memory registration

2019-04-16T10:11:29+00:00

Current implementation was not properly handling frwr memory
registrations. This was uncovered by commit 27f26cec761das ("xprtrdma:
Plant XID in on-the-wire RDMA offset (FRWR)") in which xprtrdma, which is
used for NFS over RDMA, started failing as it was the first ULP to modify
the ib_mr iova resulting in the NFS server getting REMOTE ACCESS ERROR
when attempting to perform RDMA Writes to the client.

The fix is to properly capture the true iova, offset, and length in the
call to ib_map_mr_sg, and then update the iova when processing the
IB_WR_REG_MEM on the send queue.

Fixes: a41081aa5936 ("IB/rdmavt: Add support for ib_map_mr_sg")
Cc: stable@vger.kernel.org
Reviewed-by: Mike Marciniszyn 
Reviewed-by: Dennis Dalessandro 
Reviewed-by: Michael J. Ruhl 
Signed-off-by: Josh Collier 
Signed-off-by: Dennis Dalessandro 
Signed-off-by: Jason Gunthorpe

IB/hfi1: Do not flush send queue in the TID RDMA second leg

2019-04-10T18:09:30+00:00

When a QP is put into error state, the send queue will be flushed.
This mechanism is implemented in both the first and the second leg
of the send engine. Since the second leg is only responsible for
data transactions in the KDETH space for the TID RDMA WRITE request,
it should not perform the flushing of the send queue.

This patch removes the flushing function of the second leg, but
still keeps the bailing out of the QP if it is put into error state.

Fixes: 70dcb2e3dc6a ("IB/hfi1: Add the TID second leg send packet builder")
Reviewed-by: Mike Marciniszyn 
Signed-off-by: Kaike Wan 
Signed-off-by: Dennis Dalessandro 
Signed-off-by: Jason Gunthorpe