hns_roce_alloc_mtt_range() never return -1, ret should be checked
whether it is zero instead of -1.

Fixes: 1ceb0b11 ("RDMA/hns: Fix non-standard error codes")
Link: https://lore.kernel.org/r/1584674622-52773-3-git-send-email-liweihang@huawei.comSigned-off-by: NWeihang Li <liweihang@huawei.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Use ibdev_err/dbg/warn() instead of dev_err/dbg/warn(), and modify some
prints into format of "failed to do something, ret = n".

Link: https://lore.kernel.org/r/1584674622-52773-2-git-send-email-liweihang@huawei.comSigned-off-by: NLijun Ou <oulijun@huawei.com>
Signed-off-by: NWeihang Li <liweihang@huawei.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

libiscsi calls the check_protection transport handler only if SCSI-Respose
is received. So, the handler is never called if iSCSI task is completed
for some other reason like a timeout or error handling. And this behavior
looks correct. But the iSER does not handle this case properly because it
puts a non-checked signature MR to the free pool. Then the error occurs at
reusing the MR because it is not allowed to invalidate a signature MR
without checking.

This commit adds an extra check to iser_unreg_mem_fastreg(), which is a
part of the task cleanup flow. Now the signature MR is checked there if it
is needed.

Link: https://lore.kernel.org/r/20200325151210.1548-1-sergeygo@mellanox.comSigned-off-by: NSergey Gorenko <sergeygo@mellanox.com>
Reviewed-by: NMax Gurtovoy <maxg@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

The RXE driver doesn't set sys_image_guid and user space applications see
zeros. This causes to pyverbs tests to fail with the following traceback,
because the IBTA spec requires to have valid sys_image_guid.

 Traceback (most recent call last):
   File "./tests/test_device.py", line 51, in test_query_device
     self.verify_device_attr(attr)
   File "./tests/test_device.py", line 74, in verify_device_attr
     assert attr.sys_image_guid != 0

In order to fix it, set sys_image_guid to be equal to node_guid.

Before:
 5: rxe0: ... node_guid 5054:00ff:feaa:5363 sys_image_guid
 0000:0000:0000:0000

After:
 5: rxe0: ... node_guid 5054:00ff:feaa:5363 sys_image_guid
 5054:00ff:feaa:5363

Fixes: 8700e3e7 ("Soft RoCE driver")
Link: https://lore.kernel.org/r/20200323112800.1444784-1-leon@kernel.orgSigned-off-by: NZhu Yanjun <yanjunz@mellanox.com>
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Since snprintf() returns the would-be-output size instead of the actual
output size, the succeeding calls may go beyond the given buffer limit.
Fix it by replacing with scnprintf().

Link: https://lore.kernel.org/r/20200319154641.23711-1-tiwai@suse.deSigned-off-by: NTakashi Iwai <tiwai@suse.de>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

After a successful allocation of path_rec, num_paths is set to 1, but any
error after such allocation will leave num_paths uncleared.

This causes to de-referencing a NULL pointer later on. Hence, num_paths
needs to be set back to 0 if such an error occurs.

The following crash from syzkaller revealed it.

  kasan: CONFIG_KASAN_INLINE enabled
  kasan: GPF could be caused by NULL-ptr deref or user memory access
  general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
  CPU: 0 PID: 357 Comm: syz-executor060 Not tainted 4.18.0+ #311
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
  rel-1.11.0-0-g63451fca13-prebuilt.qemu-project.org 04/01/2014
  RIP: 0010:ib_copy_path_rec_to_user+0x94/0x3e0
  Code: f1 f1 f1 f1 c7 40 0c 00 00 f4 f4 65 48 8b 04 25 28 00 00 00 48 89
  45 c8 31 c0 e8 d7 60 24 ff 48 8d 7b 4c 48 89 f8 48 c1 e8 03 <42> 0f b6
  14 30 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85
  RSP: 0018:ffff88006586f980 EFLAGS: 00010207
  RAX: 0000000000000009 RBX: 0000000000000000 RCX: 1ffff1000d5fe475
  RDX: ffff8800621e17c0 RSI: ffffffff820d45f9 RDI: 000000000000004c
  RBP: ffff88006586fa50 R08: ffffed000cb0df73 R09: ffffed000cb0df72
  R10: ffff88006586fa70 R11: ffffed000cb0df73 R12: 1ffff1000cb0df30
  R13: ffff88006586fae8 R14: dffffc0000000000 R15: ffff88006aff2200
  FS: 00000000016fc880(0000) GS:ffff88006d000000(0000)
  knlGS:0000000000000000
  CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000000020000040 CR3: 0000000063fec000 CR4: 00000000000006b0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  Call Trace:
  ? ib_copy_path_rec_from_user+0xcc0/0xcc0
  ? __mutex_unlock_slowpath+0xfc/0x670
  ? wait_for_completion+0x3b0/0x3b0
  ? ucma_query_route+0x818/0xc60
  ucma_query_route+0x818/0xc60
  ? ucma_listen+0x1b0/0x1b0
  ? sched_clock_cpu+0x18/0x1d0
  ? sched_clock_cpu+0x18/0x1d0
  ? ucma_listen+0x1b0/0x1b0
  ? ucma_write+0x292/0x460
  ucma_write+0x292/0x460
  ? ucma_close_id+0x60/0x60
  ? sched_clock_cpu+0x18/0x1d0
  ? sched_clock_cpu+0x18/0x1d0
  __vfs_write+0xf7/0x620
  ? ucma_close_id+0x60/0x60
  ? kernel_read+0x110/0x110
  ? time_hardirqs_on+0x19/0x580
  ? lock_acquire+0x18b/0x3a0
  ? finish_task_switch+0xf3/0x5d0
  ? _raw_spin_unlock_irq+0x29/0x40
  ? _raw_spin_unlock_irq+0x29/0x40
  ? finish_task_switch+0x1be/0x5d0
  ? __switch_to_asm+0x34/0x70
  ? __switch_to_asm+0x40/0x70
  ? security_file_permission+0x172/0x1e0
  vfs_write+0x192/0x460
  ksys_write+0xc6/0x1a0
  ? __ia32_sys_read+0xb0/0xb0
  ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe
  ? do_syscall_64+0x1d/0x470
  do_syscall_64+0x9e/0x470
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

Fixes: 3c86aa70 ("RDMA/cm: Add RDMA CM support for IBoE devices")
Link: https://lore.kernel.org/r/20200318101741.47211-1-leon@kernel.orgSigned-off-by: NAvihai Horon <avihaih@mellanox.com>
Reviewed-by: NMaor Gottlieb <maorg@mellanox.com>
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Now that we have direct and reliable detection of WC support by the
system, use is broadly. The only case we have to worry about is when the
WC autodetector cannot run.

For this fringe case generally assume that that WC is available, except in
the well defined case of no PAT support on x86 which is tested by calling
arch_can_pci_mmap_wc().

If WC is wrongly assumed to be available then it causes a small
performance hit on paths in userspace that are tuned to the assumption
that WC is available. There is no functional loss.

It is very unlikely that any platforms exist that lack WC and also care
about the micro optimization of WC in the fringe case where autodetection
does not work.

By removing the fairly bogus CONFIG tests this makes WC work broadly on
all arches and all platforms.

Link: https://lore.kernel.org/r/20200318100323.46659-1-leon@kernel.orgSigned-off-by: NYishai Hadas <yishaih@mellanox.com>
Reviewed-by: NMichael Guralnik <michaelgur@mellanox.com>
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Optimizes hns_roce_table_mhop_get() by encapsulating code about clearing
hem into clear_mhop_hem(), which will make the code flow clearer.

Link: https://lore.kernel.org/r/1584417324-2255-3-git-send-email-liweihang@huawei.comSigned-off-by: NXi Wang <wangxi11@huawei.com>
Signed-off-by: NWeihang Li <liweihang@huawei.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Splits hns_roce_table_mhop_get() into 4 sub-functions to make the code flow
clearer.

Link: https://lore.kernel.org/r/1584417324-2255-2-git-send-email-liweihang@huawei.comSigned-off-by: NXi Wang <wangxi11@huawei.com>
Signed-off-by: NWeihang Li <liweihang@huawei.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Destroy CQ command to firmware returns the num_cnq_events as a
response. This indicates the driver about the number of CQ events
generated for this CQ. Driver should wait for all these events before
freeing the CQ host structures.  Also, add routine to clean all the
pending notification for the CQs getting destroyed. This avoids the
possibility of accessing the CQ data structures after its freed.

Fixes: 1ac5a404 ("RDMA/bnxt_re: Add bnxt_re RoCE driver")
Link: https://lore.kernel.org/r/1584120842-3200-1-git-send-email-selvin.xavier@broadcom.comSigned-off-by: NSelvin Xavier <selvin.xavier@broadcom.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

The kzalloc() function returns NULL, not error pointers.

Fixes: 30f2fe40 ("IB/mlx5: Introduce UAPIs to manage packet pacing")
Link: https://lore.kernel.org/r/20200320132641.GF95012@mwandaSigned-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Acked-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/sw/siw/siw_qp_rx.c: In function siw_proc_send:
./include/linux/spinlock.h:288:3: warning: flags may be used uninitialized in this function [-Wmaybe-uninitialized]
   _raw_spin_unlock_irqrestore(lock, flags); \
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/infiniband/sw/siw/siw_qp_rx.c:335:16: note: flags was declared here
  unsigned long flags;

Link: https://lore.kernel.org/r/20200323184627.ZWPg91uin%akpm@linux-foundation.orgSigned-off-by: NAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Remove custom and duplicated variant of offsetofend().

Link: https://lore.kernel.org/r/20200310091438.248429-4-leon@kernel.orgSigned-off-by: NLeon Romanovsky <leonro@mellanox.com>
Acked-by: NGal Pressman <galpress@amazon.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

The field kobj was added to hfi1_devdata structure to manage the life time
of the hfi1_devdata structure for PSM accesses:

commit e11ffbd5 ("IB/hfi1: Do not free hfi1 cdev parent structure early")

Later another mechanism user_refcount/user_comp was introduced to provide
the same functionality:

commit acd7c8fe ("IB/hfi1: Fix an Oops on pci device force remove")

This patch will remove this kobj field, as it is no longer needed.

Link: https://lore.kernel.org/r/20200316210500.7753.4145.stgit@awfm-01.aw.intel.comReviewed-by: NMike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: NKaike Wan <kaike.wan@intel.com>
Signed-off-by: NDennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

This routine was obsoleted by the patch below.

Delete it.

Fixes: a2a074ef ("RDMA: Handle ucontext allocations by IB/core")
Link: https://lore.kernel.org/r/20200316210454.7753.94689.stgit@awfm-01.aw.intel.comReviewed-by: NKaike Wan <kaike.wan@intel.com>
Signed-off-by: NMike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: NDennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Depth of qp shouldn't be allowed to be set to zero, after ensuring that,
subsequent process can be simplified. And when qp is changed from reset to
reset, the capability of minimum qp depth was used to identify hardware of
hip06, it should be changed into a more readable form.

Link: https://lore.kernel.org/r/1584006624-11846-1-git-send-email-liweihang@huawei.comSigned-off-by: NLang Cheng <chenglang@huawei.com>
Signed-off-by: NWeihang Li <liweihang@huawei.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

The driver uses a hard-coded value for FW version and reports an
inconsistent FW version between ibv_devinfo and
/sys/class/infiniband/i40iw/fw_ver.

Retrieve the FW version via a Control QP (CQP) operation and report it
consistently across sysfs and query device.

Fixes: d3749841 ("i40iw: add files for iwarp interface")
Link: https://lore.kernel.org/r/20200313214406.2159-1-shiraz.saleem@intel.comReported-by: NJarod Wilson <jarod@redhat.com>
Signed-off-by: NSindhu, Devale <sindhu.devale@intel.com>
Signed-off-by: NShiraz Saleem <shiraz.saleem@intel.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Splits hns_roce_v2_post_send() into three sub-functions: set_rc_wqe(),
set_ud_wqe() and update_sq_db() to simplify the code.

Link: https://lore.kernel.org/r/1583839084-31579-6-git-send-email-liweihang@huawei.comSigned-off-by: NXi Wang <wangxi11@huawei.com>
Signed-off-by: NWeihang Li <liweihang@huawei.com>
Reviewed-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Currently, before the qp is created, a page size needs to be calculated
for the base address table to store all base addresses in the mtr. As a
result, the parameter configuration of the mtr is complex. So integrate
the process of calculating the base table page size into the hem related
interface to simplify the process of using mtr.

Link: https://lore.kernel.org/r/1583839084-31579-5-git-send-email-liweihang@huawei.comSigned-off-by: NXi Wang <wangxi11@huawei.com>
Signed-off-by: NWeihang Li <liweihang@huawei.com>
Reviewed-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Simplify the wr opcode conversion from ib to hns by using a map table
instead of the switch-case statement.

Link: https://lore.kernel.org/r/1583839084-31579-4-git-send-email-liweihang@huawei.comSigned-off-by: NXi Wang <wangxi11@huawei.com>
Signed-off-by: NWeihang Li <liweihang@huawei.com>
Reviewed-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Encapsulates the wqe buffer process details for datagram seg, fast mr seg
and atomic seg.

Link: https://lore.kernel.org/r/1583839084-31579-3-git-send-email-liweihang@huawei.comSigned-off-by: NXi Wang <wangxi11@huawei.com>
Signed-off-by: NWeihang Li <liweihang@huawei.com>
Reviewed-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

There are serval global functions related to wqe buffer in the hns driver
and are called in different files. These symbols cannot directly represent
the namespace they belong to. So add prefix 'hns_roce_' to 3 wqe buffer
related global functions: get_recv_wqe(), get_send_wqe(), and
get_send_extend_sge().

Link: https://lore.kernel.org/r/1583839084-31579-2-git-send-email-liweihang@huawei.comSigned-off-by: NXi Wang <wangxi11@huawei.com>
Signed-off-by: NWeihang Li <liweihang@huawei.com>
Reviewed-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Since the lifetime of bnxt_re_task is controlled by the kref of device,
sched_count is no longer required.  Remove it.

Link: https://lore.kernel.org/r/1584117207-2664-4-git-send-email-selvin.xavier@broadcom.comSigned-off-by: NSelvin Xavier <selvin.xavier@broadcom.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

A work queue cannot just rely on the ib_device not being freed, it must
hold a kref on the memory so that the BNXT_RE_FLAG_IBDEV_REGISTERED check
works.

Fixes: 1ac5a404 ("RDMA/bnxt_re: Add bnxt_re RoCE driver")
Link: https://lore.kernel.org/r/1584117207-2664-3-git-send-email-selvin.xavier@broadcom.comSigned-off-by: NSelvin Xavier <selvin.xavier@broadcom.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

There are a couple places in this driver running from a work queue that
need the ib_device to be registered. Instead of using a broken internal
bit rely on the new core code to guarantee device registration.

Link: https://lore.kernel.org/r/1584117207-2664-2-git-send-email-selvin.xavier@broadcom.comSigned-off-by: NSelvin Xavier <selvin.xavier@broadcom.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

The first switch statement in cm_destroy_id() tries to move the ID to
either IB_CM_IDLE or IB_CM_TIMEWAIT. Both states will block concurrent
MAD handlers from progressing.

Previous patches removed the unreliably lock/unlock sequences in this
flow, this patch removes the extra locking steps and adds the missing
parts to guarantee that destroy reaches IB_CM_IDLE. There is no point in
leaving the ID in the IB_CM_TIMEWAIT state the memory about to be kfreed.

Rework things to hold the lock across all the state transitions and
directly assert when done that it ended up in IB_CM_IDLE as expected.

This was accompanied by a careful audit of all the state transitions here,
which generally did end up in IDLE on their success and non-racy paths.

Link: https://lore.kernel.org/r/20200310092545.251365-16-leon@kernel.orgSigned-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

The first thing ib_send_cm_sidr_rep() does is obtain the lock, so use the
usual unlocked wrapper, locked actor pattern here.

Get rid of the cm_reject_sidr_req() wrapper so each call site can call the
locked or unlocked version as required.

This avoids a sketchy lock/unlock sequence (which could allow state to
change) during cm_destroy_id().

Link: https://lore.kernel.org/r/20200310092545.251365-15-leon@kernel.orgSigned-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

The first thing ib_send_cm_rej() does is obtain the lock, so use the usual
unlocked wrapper, locked actor pattern here.

This avoids a sketchy lock/unlock sequence (which could allow state to
change) during cm_destroy_id().

While here simplify some of the logic in the implementation.

Link: https://lore.kernel.org/r/20200310092545.251365-14-leon@kernel.orgSigned-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

The first thing ib_send_cm_drep() does is obtain the lock, so use the
usual unlocked wrapper, locked actor pattern here.

This avoids a sketchy lock/unlock sequence (which could allow state to
change) during cm_destroy_id().

Link: https://lore.kernel.org/r/20200310092545.251365-13-leon@kernel.orgSigned-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

The first thing ib_send_cm_dreq() does is obtain the lock, so use the
usual unlocked wrapper, locked actor pattern here.

This avoids a sketchy lock/unlock sequence (which could allow state to
change) during cm_destroy_id().

Link: https://lore.kernel.org/r/20200310092545.251365-12-leon@kernel.orgSigned-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

These functions all touch state, so must be called under the lock.
Inspection shows this is currently true.

Link: https://lore.kernel.org/r/20200310092545.251365-11-leon@kernel.orgSigned-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

All accesses to id.state must be done under the spinlock.

Fixes: a977049d ("[PATCH] IB: Add the kernel CM implementation")
Link: https://lore.kernel.org/r/20200310092545.251365-10-leon@kernel.orgSigned-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

ib_crate_cm_id() immediately places the id in the xarray, and publishes it
into the remote_id and remote_qpn rbtrees. This makes it visible to other
threads before it is fully set up.

It appears the thinking here was that the states IB_CM_IDLE and
IB_CM_REQ_RCVD do not allow any MAD handler or lookup in the remote_id and
remote_qpn rbtrees to advance.

However, cm_rej_handler() does take an action on IB_CM_REQ_RCVD, which is
not really expected by the design.

Make the whole thing clearer:
 - Keep the new cm_id out of the xarray until it is completely set up.
   This directly prevents MAD handlers and all rbtree lookups from seeing
   the pointer.
 - Move all the trivial setup right to the top so it is obviously done
   before any concurrency begins
 - Move the mutation of the cm_id_priv out of cm_match_id() and into the
   caller so the state transition is obvious
 - Place the manipulation of the work_list at the end, under lock, after
   the cm_id is placed in the xarray. The work_count cannot change on an
   ID outside the xarray.
 - Add some comments

Link: https://lore.kernel.org/r/20200310092545.251365-9-leon@kernel.orgSigned-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

ib_create_cm_id() immediately places the id in the xarray, so it is visible
to network traffic.

The state is initially set to IB_CM_IDLE and all the MAD handlers will
test this state under lock and refuse to advance from IDLE, so adding to
the xarray is harmless.

Further, the set to IB_CM_SIDR_REQ_RCVD also excludes all MAD handlers.

However, the local_id isn't even used for SIDR mode, and there will be no
input MADs related to the newly created ID.

So, make the whole flow simpler so it can be understood:
 - Do not put the SIDR cm_id in the xarray. This directly shows that there
   is no concurrency
 - Delete the confusing work_count and pending_list manipulations. This
   mechanism is only used by MAD handlers and timewait, neither of which
   apply to SIDR.
 - Add a few comments and rename 'cur_cm_id_priv' to 'listen_cm_id_priv'
 - Move other loose sets up to immediately after cm_id creation so that
   the cm_id is fully configured right away. This fixes an oversight where
   the service_id will not be returned back on a IB_SIDR_UNSUPPORTED
   reject.

Link: https://lore.kernel.org/r/20200310092545.251365-8-leon@kernel.orgSigned-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

The lock should not be dropped before doing the pr_debug() print as it is
accessing data protected by the lock, such as id.state.

Fixes: 119bf817 ("IB/cm: Add debug prints to ib_cm")
Link: https://lore.kernel.org/r/20200310092545.251365-7-leon@kernel.orgSigned-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Any manipulation of cm_id->state must be done under the cm_id_priv->lock,
the two routines that added listens did not follow this rule, because they
never participate in any concurrent access around the state.

However, since this exception makes the code hard to understand, simplify
the flow so that it can be fully locked:
 - Move manipulation of listen_sharecount into cm_insert_listen() so it is
   trivially under the cm.lock without having to expose the cm.lock to the
   caller.
 - Push the cm.lock down into cm_insert_listen() and have the function
   increment the reference count before returning an existing pointer.
 - Split ib_cm_listen() into an cm_init_listen() and do not call
   ib_cm_listen() from ib_cm_insert_listen()
 - Make both ib_cm_listen() and ib_cm_insert_listen() directly call
   cm_insert_listen() under their cm_id_priv->lock which does both a
   collision detect and, if needed, the insert (atomically)
 - Enclose all state manipulation within the cm_id_priv->lock, notice this
   set can be done safely after cm_insert_listen() as no reader is allowed
   to read the state without holding the lock.
 - Do not set the listen cm_id in the xarray, as it is never correct to
   look it up. This makes the concurrency simpler to understand.

Many needless error unwinds are removed in the process.

Link: https://lore.kernel.org/r/20200310092545.251365-6-leon@kernel.orgSigned-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Too much of the destruction is very carefully sensitive to the state
and various other things. Move more code to the unconditional path and
add several WARN_ONs to check consistency.

Link: https://lore.kernel.org/r/20200310092545.251365-5-leon@kernel.orgSigned-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

When creating a cm_id during REQ the id immediately becomes visible to the
other MAD handlers, and shortly after the state is moved to IB_CM_REQ_RCVD

This allows cm_rej_handler() to run concurrently and free the work:

        CPU 0                                CPU1
 cm_req_handler()
  ib_create_cm_id()
  cm_match_req()
    id_priv->state = IB_CM_REQ_RCVD
                                       cm_rej_handler()
                                         cm_acquire_id()
                                         spin_lock(&id_priv->lock)
                                         switch (id_priv->state)
  					   case IB_CM_REQ_RCVD:
                                            cm_reset_to_idle()
                                             kfree(id_priv->timewait_info);
   goto destroy
  destroy:
    kfree(id_priv->timewait_info);
                                             id_priv->timewait_info = NULL

Causing a double free or worse.

Do not free the timewait_info without also holding the
id_priv->lock. Simplify this entire flow by making the free unconditional
during cm_destroy_id() and removing the confusing special case error
unwind during creation of the timewait_info.

This also fixes a leak of the timewait if cm_destroy_id() is called in
IB_CM_ESTABLISHED with an XRC TGT QP. The state machine will be left in
ESTABLISHED while it needed to transition through IB_CM_TIMEWAIT to
release the timewait pointer.

Also fix a leak of the timewait_info if the caller mis-uses the API and
does ib_send_cm_reqs().

Fixes: a977049d ("[PATCH] IB: Add the kernel CM implementation")
Link: https://lore.kernel.org/r/20200310092545.251365-4-leon@kernel.orgSigned-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

The test here typod the cm_id_priv to use, it used the one that was
freshly allocated. By definition the allocated one has the matching
cm_handler and zero context, so the condition was always true.

Instead check that the existing listening ID is compatible with the
proposed handler so that it can be shared, as was originally intended.

Fixes: 067b171b ("IB/cm: Share listening CM IDs")
Link: https://lore.kernel.org/r/20200310092545.251365-3-leon@kernel.orgSigned-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

xa_alloc_cyclic() is a SMP release to be paired with some later acquire
during xa_load() as part of cm_acquire_id().

As such, xa_alloc_cyclic() must be done after the cm_id is fully
initialized, in particular, it absolutely must be after the
refcount_set(), otherwise the refcount_inc() in cm_acquire_id() may not
see the set.

As there are several cases where a reader will be able to use the
id.local_id after cm_acquire_id in the IB_CM_IDLE state there needs to be
an unfortunate split into a NULL allocate and a finalizing xa_store.

Fixes: a977049d ("[PATCH] IB: Add the kernel CM implementation")
Link: https://lore.kernel.org/r/20200310092545.251365-2-leon@kernel.orgSigned-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>