Commit Graph

230 Commits

Author SHA1 Message Date
Gustavo A. R. Silva
df561f6688 treewide: Use fallthrough pseudo-keyword
Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-08-23 17:36:59 -05:00
Maor Gottlieb
87c4c774cb RDMA/cm: Protect access to remote_sidr_table
cm.lock must be held while accessing remote_sidr_table. This fixes the
below NULL pointer dereference.

  BUG: kernel NULL pointer dereference, address: 0000000000000000
  #PF: supervisor write access in kernel mode
  #PF: error_code(0x0002) - not-present page
  PGD 0 P4D 0
  Oops: 0002 [#1] SMP PTI
  CPU: 2 PID: 7288 Comm: udaddy Not tainted 5.7.0_for_upstream_perf_2020_06_09_15_14_20_38 #1
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014
  RIP: 0010:rb_erase+0x10d/0x360
  Code: 00 00 00 48 89 c1 48 89 d0 48 8b 50 08 48 39 ca 74 48 f6 02 01 75 af 48 8b 7a 10 48 89 c1 48 83 c9 01 48 89 78 08 48 89 42 10 <48> 89 0f 48 8b 08 48 89 0a 48 83 e1 fc 48 89 10 0f 84 b1 00 00 00
  RSP: 0018:ffffc90000f77c30 EFLAGS: 00010086
  RAX: ffff8883df27d458 RBX: ffff8883df27da58 RCX: ffff8883df27d459
  RDX: ffff8883d183fa58 RSI: ffffffffa01e8d00 RDI: 0000000000000000
  RBP: ffff8883d62ac800 R08: 0000000000000000 R09: 00000000000000ce
  R10: 000000000000000a R11: 0000000000000000 R12: ffff8883df27da00
  R13: ffffc90000f77c98 R14: 0000000000000130 R15: 0000000000000000
  FS:  00007f009f877740(0000) GS:ffff8883f1a00000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000000000000000 CR3: 00000003d467e003 CR4: 0000000000160ee0
  Call Trace:
   cm_send_sidr_rep_locked+0x15a/0x1a0 [ib_cm]
   ib_send_cm_sidr_rep+0x2b/0x50 [ib_cm]
   cma_send_sidr_rep+0x8b/0xe0 [rdma_cm]
   __rdma_accept+0x21d/0x2b0 [rdma_cm]
   ? ucma_get_ctx+0x2b/0xe0 [rdma_ucm]
   ? _copy_from_user+0x30/0x60
   ucma_accept+0x13e/0x1e0 [rdma_ucm]
   ucma_write+0xb4/0x130 [rdma_ucm]
   vfs_write+0xad/0x1a0
   ksys_write+0x9d/0xb0
   do_syscall_64+0x48/0x130
   entry_SYSCALL_64_after_hwframe+0x44/0xa9
  RIP: 0033:0x7f009ef60924
  Code: 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 80 00 00 00 00 8b 05 2a ef 2c 00 48 63 ff 85 c0 75 13 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 f3 c3 66 90 55 53 48 89 d5 48 89 f3 48 83
  RSP: 002b:00007fff843edf38 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
  RAX: ffffffffffffffda RBX: 000055743042e1d0 RCX: 00007f009ef60924
  RDX: 0000000000000130 RSI: 00007fff843edf40 RDI: 0000000000000003
  RBP: 00007fff843ee0e0 R08: 0000000000000000 R09: 0000557430433090
  R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000
  R13: 00007fff843edf40 R14: 000000000000038c R15: 00000000ffffff00
  CR2: 0000000000000000

Fixes: 6a8824a74b ("RDMA/cm: Allow ib_send_cm_sidr_rep() to be done under lock")
Link: https://lore.kernel.org/r/20200716105519.1424266-1-leon@kernel.org
Signed-off-by: Maor Gottlieb <maorg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2020-07-16 09:58:53 -03:00
Leon Romanovsky
1ea7c546b8 RDMA/core: Annotate CMA unlock helper routine
Fix the following sparse error by adding annotation to
cm_queue_work_unlock() that it releases cm_id_priv->lock lock.

 drivers/infiniband/core/cm.c:936:24: warning: context imbalance in
 'cm_queue_work_unlock' - unexpected unlock

Fixes: e83f195aa4 ("RDMA/cm: Pull duplicated code into cm_queue_work_unlock()")
Link: https://lore.kernel.org/r/20200611130045.1994026-1-leon@kernel.org
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-06-18 09:34:42 -03:00
Ka-Cheong Poon
fba97dc7fc RDMA/cm: Spurious WARNING triggered in cm_destroy_id()
If the cm_id state is IB_CM_REP_SENT when cm_destroy_id() is called, it
calls cm_send_rej_locked().

In cm_send_rej_locked(), it calls cm_enter_timewait() and the state is
changed to IB_CM_TIMEWAIT.

Now back to cm_destroy_id(), it breaks from the switch statement, and the
next call is WARN_ON(cm_id->state != IB_CM_IDLE).

This triggers a spurious warning. Instead, the code should goto retest
after returning from cm_send_rej_locked() to move the state to IDLE.

Fixes: 67b3c8dcea ("RDMA/cm: Make sure the cm_id is in the IB_CM_IDLE state in destroy")
Link: https://lore.kernel.org/r/1591191218-9446-1-git-send-email-ka-cheong.poon@oracle.com
Signed-off-by: Ka-Cheong Poon <ka-cheong.poon@oracle.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-06-03 15:48:18 -03:00
Leon Romanovsky
a20652e175 RDMA/cm: Send and receive ECE parameter over the wire
ECE parameters are exchanged through REQ->REP/SIDR_REP messages, this
patch adds the data to provide to other side of CMID communication
channel.

Link: https://lore.kernel.org/r/20200526103304.196371-5-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-05-27 16:05:05 -03:00
Jason Gunthorpe
eafd47fc20 Linux 5.7-rc6
-----BEGIN PGP SIGNATURE-----
 
 iQFSBAABCAA8FiEEq68RxlopcLEwq+PEeb4+QwBBGIYFAl7BzV8eHHRvcnZhbGRz
 QGxpbnV4LWZvdW5kYXRpb24ub3JnAAoJEHm+PkMAQRiGg8EH/A2pXMTxtc96RI4S
 sttEsUQqbakFS0Z/2tQPpMGr/qW2e5eHgsTX/a3SiUeZiIXk6f4lMFkMuctzBf7p
 X77cNEDwGOEdbtCXTsMcmKSde7sP2zCXsPB8xTWLyE6rnaFRgikwwkeqgkIKhp1h
 bvOQV0t9HNGvxGAM0iZeOvQAvFl4vd7nS123/MYbir9cugfQUSJRueQ4BiCiJqVE
 6cNA7/vFzDJuFGszzIrJ7HXn/IdQMMWHkvTDjgBw0GZw1mDbGFbfbZwOeTz1ojCt
 smUQ4tIFxBa/VA5zx7dOy2P2keHbSVf4VLkZRPcceT7OqVS65ETmFDp+qt5NdWM5
 vZ8+7/0=
 =CyYH
 -----END PGP SIGNATURE-----

Merge tag 'v5.7-rc6' into rdma.git for-next

Linux 5.7-rc6

Conflict in drivers/net/ethernet/mellanox/mlx5/core/steering/dr_send.c
resolved by deleting dr_cq_event, matching how netdev resolved it.

Required for dependencies in the following patches.

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-05-21 17:08:27 -03:00
Jason Gunthorpe
a0e46db4e7 RDMA/cm: Increment the refcount inside cm_find_listen()
All callers need the 'get', so do it in a central place before returning
the pointer.

Link: https://lore.kernel.org/r/20200506074701.9775-11-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-05-12 21:32:54 -03:00
Jason Gunthorpe
51e8463cfc RDMA/cm: Remove needless cm_id variable
Just put the expression in the only reader

Link: https://lore.kernel.org/r/20200506074701.9775-10-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-05-12 21:32:54 -03:00
Jason Gunthorpe
1cc44279f2 RDMA/cm: Remove the cm_free_id() wrapper function
Just call xa_erase directly during cm_destroy_id()

Link: https://lore.kernel.org/r/20200506074701.9775-9-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-05-12 21:32:54 -03:00
Jason Gunthorpe
cfa68b0d04 RDMA/cm: Make find_remote_id() return a cm_id_private
The only caller doesn't care about the timewait, so acquire and return the
cm_id_private from the function.

Link: https://lore.kernel.org/r/20200506074701.9775-8-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-05-12 21:32:54 -03:00
Jason Gunthorpe
09fb406a56 RDMA/cm: Add a note explaining how the timewait is eventually freed
The way the cm_timewait_info is converted into a work and then freed
is very subtle and surprising, add a note clarifying the lifetime
here.

Link: https://lore.kernel.org/r/20200506074701.9775-7-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-05-12 21:32:53 -03:00
Jason Gunthorpe
9767a27e1a RDMA/cm: Pass the cm_id_private into cm_cleanup_timewait
Also rename it to cm_remove_remote(). This function now removes the
tracking of the remote ID/QPN in the redblack trees from a cm_id_private.

Replace a open-coded version with a call. The open coded version was
deleting only the remote_id, however at this call site the qpn can not
have been in the RB tree either, so the cm_remove_remote() will do the
same.

Link: https://lore.kernel.org/r/20200506074701.9775-6-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-05-12 21:32:53 -03:00
Jason Gunthorpe
e83f195aa4 RDMA/cm: Pull duplicated code into cm_queue_work_unlock()
While unlocking a spinlock held by the caller is a disturbing pattern,
this extensively duplicated code is even worse. Pull all the duplicates
into a function and explain the purpose of the algorithm.

The on creation side call in cm_req_handler() which is different has been
micro-optimized on the basis that the work_count == -1 during creation,
remove that and just use the normal function.

Link: https://lore.kernel.org/r/20200506074701.9775-5-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-05-12 21:32:53 -03:00
Danit Goldberg
42113eed8f RDMA/cm: Remove unused store to ret in cm_rej_handler
The 'goto out' label doesn't read ret, so don't set it.

Link: https://lore.kernel.org/r/20200506074701.9775-4-leon@kernel.org
Signed-off-by: Danit Goldberg <danitg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-05-12 21:32:53 -03:00
Jason Gunthorpe
d3552fb65d RDMA/cm: Remove return code from add_cm_id_to_port_list
This cannot happen, all callers pass in one of the two pointers. Use
a WARN_ON guard instead.

Link: https://lore.kernel.org/r/20200506074701.9775-3-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-05-12 21:32:53 -03:00
Jason Gunthorpe
11a0ae4c4b RDMA: Allow ib_client's to fail when add() is called
When a client is added it isn't allowed to fail, but all the client's have
various failure paths within their add routines.

This creates the very fringe condition where the client was added, failed
during add and didn't set the client_data. The core code will then still
call other client_data centric ops like remove(), rename(), get_nl_info(),
and get_net_dev_by_params() with NULL client_data - which is confusing and
unexpected.

If the add() callback fails, then do not call any more client ops for the
device, even remove.

Remove all the now redundant checks for NULL client_data in ops callbacks.

Update all the add() callbacks to return error codes
appropriately. EOPNOTSUPP is used for cases where the ULP does not support
the ib_device - eg because it only works with IB.

Link: https://lore.kernel.org/r/20200421172440.387069-1-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Acked-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-05-06 11:57:33 -03:00
Dan Carpenter
9836535158 RDMA/cm: Fix an error check in cm_alloc_id_priv()
The xa_alloc_cyclic_irq() function returns either 0 or 1 on success and
negatives on error.  This code treats 1 as an error and returns ERR_PTR(1)
which will cause an Oops in the caller.

Fixes: ae78ff3a0f ("RDMA/cm: Convert local_id_table to XArray")
Link: https://lore.kernel.org/r/20200407093714.GA80285@mwanda
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-04-14 16:01:38 -03:00
Leon Romanovsky
0c6949c3d1 RDMA/cm: Fix missing RDMA_CM_EVENT_REJECTED event after receiving REJ message
The cm_reset_to_idle() call before formatting event changed the CM_ID
state from IB_CM_REQ_RCVD to be IB_CM_IDLE. It caused to wrong value of
CM_REJ_MESSAGE_REJECTED field.

The result of that was that rdma_reject() calls in the passive side didn't
generate RDMA_CM_EVENT_REJECTED event in the active side.

Fixes: 81ddb41f87 ("RDMA/cm: Allow ib_send_cm_rej() to be done under lock")
Link: https://lore.kernel.org/r/20200406173242.1465911-1-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-04-14 15:50:49 -03:00
Jason Gunthorpe
67b3c8dcea RDMA/cm: Make sure the cm_id is in the IB_CM_IDLE state in destroy
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.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-03-17 17:05:54 -03:00
Jason Gunthorpe
6a8824a74b RDMA/cm: Allow ib_send_cm_sidr_rep() to be done under lock
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.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-03-17 17:05:54 -03:00
Jason Gunthorpe
81ddb41f87 RDMA/cm: Allow ib_send_cm_rej() to be done under lock
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.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-03-17 17:05:54 -03:00
Jason Gunthorpe
87cabf3e09 RDMA/cm: Allow ib_send_cm_drep() to be done under lock
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.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-03-17 17:05:53 -03:00
Jason Gunthorpe
e029fdc068 RDMA/cm: Allow ib_send_cm_dreq() to be done under lock
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.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-03-17 17:05:53 -03:00
Jason Gunthorpe
00777a68ae RDMA/cm: Add some lockdep assertions for cm_id_priv->lock
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.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-03-17 17:05:53 -03:00
Jason Gunthorpe
d1de9a8807 RDMA/cm: Add missing locking around id.state in cm_dup_req_handler
All accesses to id.state must be done under the spinlock.

Fixes: a977049dac ("[PATCH] IB: Add the kernel CM implementation")
Link: https://lore.kernel.org/r/20200310092545.251365-10-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-03-17 17:05:53 -03:00
Jason Gunthorpe
c206f8bad1 RDMA/cm: Make it clearer how concurrency works in cm_req_handler()
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.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-03-17 17:05:52 -03:00
Jason Gunthorpe
083bfdbfd5 RDMA/cm: Make it clear that there is no concurrency in cm_sidr_req_handler()
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.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-03-17 17:05:52 -03:00
Jason Gunthorpe
153a2e432e RDMA/cm: Read id.state under lock when doing pr_debug()
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: 119bf81793 ("IB/cm: Add debug prints to ib_cm")
Link: https://lore.kernel.org/r/20200310092545.251365-7-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-03-17 17:05:52 -03:00
Jason Gunthorpe
98f67156a8 RDMA/cm: Simplify establishing a listen cm_id
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.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-03-17 17:05:52 -03:00
Jason Gunthorpe
2305d6864a RDMA/cm: Make the destroy_id flow more robust
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.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-03-17 17:05:52 -03:00
Jason Gunthorpe
bede86a39d RDMA/cm: Remove a race freeing timewait_info
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: a977049dac ("[PATCH] IB: Add the kernel CM implementation")
Link: https://lore.kernel.org/r/20200310092545.251365-4-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-03-17 17:05:51 -03:00
Jason Gunthorpe
ca21cb7fb1 RDMA/cm: Fix checking for allowed duplicate listens
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: 067b171b86 ("IB/cm: Share listening CM IDs")
Link: https://lore.kernel.org/r/20200310092545.251365-3-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-03-17 17:05:51 -03:00
Jason Gunthorpe
e8dc4e885c RDMA/cm: Fix ordering of xa_alloc_cyclic() in ib_create_cm_id()
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: a977049dac ("[PATCH] IB: Add the kernel CM implementation")
Link: https://lore.kernel.org/r/20200310092545.251365-2-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-03-17 17:05:51 -03:00
Leon Romanovsky
a4f994a059 RDMA/cm: Delete not implemented CM peer to peer communication
Peer to peer support was never implemented, so delete it to make code less
clutter.

Link: https://lore.kernel.org/r/20200310091438.248429-6-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Reviewed-by: Mark Zhang <markz@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-03-13 10:46:53 -03:00
Jason Gunthorpe
6f00a54c2c Linux 5.6-rc5
-----BEGIN PGP SIGNATURE-----
 
 iQFSBAABCAA8FiEEq68RxlopcLEwq+PEeb4+QwBBGIYFAl5lkYceHHRvcnZhbGRz
 QGxpbnV4LWZvdW5kYXRpb24ub3JnAAoJEHm+PkMAQRiGpHQH/RJrzcaZHo4lw88m
 Jf7vBZ9DYUlRgqE0pxTHWmodNObKRqpwOUGflUcWbb/7GD2LQUfeqhSECVQyTID9
 N9y7FcPvx321Qhc3EkZ24DBYk0+DQ0K2FVUrSa/PxO0n7czxxXWaLRDmlSULEd3R
 D4pVs3zEWOBXJHUAvUQ5R+lKfkeWKNeeepeh+rezuhpdWFBRNz4Jjr5QUJ8od5xI
 sIwobYmESJqTRVBHqW8g2T2/yIsFJ78GCXs8DZLe1wxh40UbxdYDTA0NDDTHKzK6
 lxzBgcmKzuge+1OVmzxLouNWMnPcjFlVgXWVerpSy3/SIFFkzzUWeMbqm6hKuhOn
 wAlcIgI=
 =VQUc
 -----END PGP SIGNATURE-----

Merge tag 'v5.6-rc5' into rdma.git for-next

Required due to dependencies in following patches.

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-03-10 12:49:09 -03:00
Jason Gunthorpe
c14dfddbd8 RMDA/cm: Fix missing ib_cm_destroy_id() in ib_cm_insert_listen()
The algorithm pre-allocates a cm_id since allocation cannot be done while
holding the cm.lock spinlock, however it doesn't free it on one error
path, leading to a memory leak.

Fixes: 067b171b86 ("IB/cm: Share listening CM IDs")
Link: https://lore.kernel.org/r/20200221152023.GA8680@ziepe.ca
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-02-27 16:43:29 -04:00
Gustavo A. R. Silva
5b361328ca RDMA: Replace zero-length array with flexible-array member
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")

Link: https://lore.kernel.org/r/20200213010425.GA13068@embeddedor.com
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> # added a few more
2020-02-20 13:33:51 -04:00
Leon Romanovsky
ca750d4a9c RDMA/ucma: Mask QPN to be 24 bits according to IBTA
IBTA declares QPN as 24bits, mask input to ensure that kernel
doesn't get higher bits and ensure by adding WANR_ONCE() that
other CM users do the same.

Link: https://lore.kernel.org/r/20200212072635.682689-2-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-02-13 11:38:19 -04:00
Jason Gunthorpe
13e0af1801 RDMA/cm: Remove CM message structs
All accesses now use the new IBA acessor scheme, so delete the structs
entirely and generate the structures from the schema file.

Link: https://lore.kernel.org/r/20200116170037.30109-8-jgg@ziepe.ca
Tested-by: Leon Romanovsky <leonro@mellanox.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-01-25 15:11:37 -04:00
Jason Gunthorpe
4ca662a30a RDMA/cm: Use IBA functions for complex structure members
Use a Coccinelle spatch to replace CM structure members used as
structures, arrays, or pointers with IBA_GET/SET versions. Applied with

$ spatch --sp-file edits.sp --in-place drivers/infiniband/core/cm.c

The spatch file was generated using the template pattern:

@@
expression src;
expression len;
{struct} *msg;
@@
- memcpy(msg->{old_name}, src, len)
+ IBA_SET_MEM({new_name}, msg, src, len)
@@
{struct} *msg;
identifier x;
@@
- msg->{old_name}.x
+ IBA_GET_MEM_PTR({new_name}, msg)->x
@@
{struct} *msg;
@@
- &msg->{old_name}
+ IBA_GET_MEM_PTR({new_name}, msg)

For GIDs:
@@
{struct} *msg;
@@
- msg->{old_name}
+ *IBA_GET_MEM_PTR({new_name}, msg)

For non-GIDs:
@@
{struct} *msg;
@@
- msg->{old_name}
+ IBA_GET_MEM_PTR({new_name}, msg)

Iterated for every remaining IBA_CHECK_OFF()/IBA_CHECK_GET()
pairing. Touched up with clang-format after.

Link: https://lore.kernel.org/r/20200116170037.30109-7-jgg@ziepe.ca
Tested-by: Leon Romanovsky <leonro@mellanox.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-01-25 15:06:01 -04:00
Jason Gunthorpe
91b60a7128 RDMA/cm: Use IBA functions for simple structure members
Use a Coccinelle spatch script to replace use of simple CM structure
members with IBA_GET/SET versions. Applied with

$ spatch --sp-file edits.sp --in-place drivers/infiniband/core/cm.c

The spatch file was generated using the template pattern:

@@
expression val;
{struct} *msg;
@@
- msg->{old_name} = val
+ IBA_SET({new_name}, msg, be{bits}_to_cpu(val))
@@
{struct} *msg;
@@
- msg->{old_name}
+ cpu_to_be{bits}(IBA_GET({new_name}, msg))

Iterated for every IBA_CHECK_OFF that isn't a CM_FIELD_MLOC.

And the below iterated over all byte sizes to remove doubled byte swaps:

@@
expression val;
@@
-be{bits}_to_cpu(cpu_to_be{bits}(val))
+val

(and __be_to_cpu and ntoh varients)

Touched up with clang-format after.

Link: https://lore.kernel.org/r/20200116170037.30109-6-jgg@ziepe.ca
Tested-by: Leon Romanovsky <leonro@mellanox.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-01-25 15:06:00 -04:00
Jason Gunthorpe
01adb7f46f RDMA/cm: Use IBA functions for swapping get/set acessors
Use a Coccinelle spatch script to replace CM helper functions that
return/accept BE values with IBA_GET/SET versions. Applied with

$ spatch --sp-file edits.sp --in-place drivers/infiniband/core/cm.c

The spatch file was generated using the template pattern:

@@
expression val;
{struct} *msg;
@@
- {old_setter}(msg, val)
+ IBA_SET({new_name}, msg, be{bits}_to_cpu(val))
@@
{struct} *msg;
@@
- {old_getter}(msg)
+ cpu_to_be{bits}(IBA_GET({new_name}, msg))

Iterated for every IBA_CHECK_GET_BE()/IBA_CHECK_SET_BE() pairing.

And the below iterated over all byte sizes to remove doubled byte swaps:

@@
expression val;
@@
-be{bits}_to_cpu(cpu_to_be{bits}(val))
+val

(and __be_to_cpu and ntoh varients)

Touched up with clang-format after.

Link: https://lore.kernel.org/r/20200116170037.30109-5-jgg@ziepe.ca
Tested-by: Leon Romanovsky <leonro@mellanox.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-01-25 15:06:00 -04:00
Jason Gunthorpe
b6bbee6889 RDMA/cm: Use IBA functions for simple get/set acessors
Use a Coccinelle spatch to replace CM helper functions with IBA_GET/SET
versions. Applied with

$ spatch --sp-file edits.sp --in-place drivers/infiniband/core/cm.c

The spatch file was generated using the template pattern:

@@
expression val;
{struct} *msg;
@@
- {old_setter}
+ IBA_SET({new_name}, msg, val)
@@
{struct} *msg;
@@
- {old_getter}
+ IBA_GET({new_name}, msg)

Iterated for every IBA_CHECK_GET()/IBA_CHECK_GET() pairing. Touched up
with clang-format after.

Link: https://lore.kernel.org/r/20200116170037.30109-4-jgg@ziepe.ca
Tested-by: Leon Romanovsky <leonro@mellanox.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-01-25 15:05:59 -04:00
Leon Romanovsky
d05d4ac4c9 RDMA/cm: Add SET/GET implementations to hide IBA wire format
There is no separation between RDMA-CM wire format as it is declared in
IBTA and kernel logic which implements needed support. Such situation
causes to many mistakes in conversion between big-endian (wire format)
and CPU format used by kernel. It also mixes RDMA core code with
combination of uXX and beXX variables.

The idea that all accesses to IBA definitions will go through special
GET/SET macros to ensure that no conversion mistakes are made. The
shifting and masking required to read the value is automatically deduced
using the field offset description from the tables in the IBA
specification.

This starts with the CM MADs described in IBTA release 1.3 volume 1.

To confirm that the new macros behave the same as the old accessors a
self-test is included in this patch.

Each macro replacing a straightforward struct field compile-time tests
that the new field has the same offsetof() and width as the old field.

For the fields with accessor functions a runtime test, the 'all ones'
value is placed in a dummy message and read back in several ways to
confirm that both approaches give identical results.

Later patches in this series delete the self test.

This creates a tested table of new field name, old field name(s) and some
meta information like BE coding for the functions which will be used in
the next patches.

Link: https://lore.kernel.org/r/20200116170037.30109-3-jgg@ziepe.ca
Link: https://lore.kernel.org/r/20191212093830.316934-5-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Tested-by: Leon Romanovsky <leonro@mellanox.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-01-25 15:05:59 -04:00
Leon Romanovsky
ad9efa05a0 RDMA/cm: Delete unused CM ARP functions
Clean the code by deleting ARP functions, which are not called anyway.

Link: https://lore.kernel.org/r/20191212093830.316934-46-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-01-03 21:07:21 -04:00
Leon Romanovsky
017d8eada8 RDMA/cm: Delete unused CM LAP functions
Clean the code by deleting LAP functions, which are not called anyway.

Link: https://lore.kernel.org/r/20191212093830.316934-43-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-01-03 21:06:21 -04:00
Danit Goldberg
4d6e8a033f RDMA/cm: Use RCU synchronization mechanism to protect cm_id_private xa_load()
The RCU mechanism is optimized for read-mostly scenarios and therefore
more suitable to protect the cm_id_private to decrease "cm.lock"
congestion.

This patch replaces the existing spinlock locking mechanism and kfree with
RCU mechanism in places where spinlock(cm.lock) protected xa_load
returning the cm_id_priv

In addition, delete the cm_get_id() function as there is no longer a
distinction if the caller already holds the cm_lock.

Remove an open coded version of cm_get_id().

Link: https://lore.kernel.org/r/20191219134750.413429-1-leon@kernel.org
Signed-off-by: Danit Goldberg <danitg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-01-03 16:29:44 -04:00
Danit Goldberg
0acc637dac RDMA/cm: Use refcount_t type for refcount variable
This atomic in struct cm_id_private is being used as a refcount, change it
to refcount_t for better clarity and to get the refcount protections.

Link: https://lore.kernel.org/r/1573997601-4502-1-git-send-email-danitg@mellanox.com
Signed-off-by: Danit Goldberg <danitg@mellanox.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2019-11-19 16:10:04 -04:00
Jason Gunthorpe
036313316d Linux 5.4-rc5
-----BEGIN PGP SIGNATURE-----
 
 iQFSBAABCAA8FiEEq68RxlopcLEwq+PEeb4+QwBBGIYFAl210Z8eHHRvcnZhbGRz
 QGxpbnV4LWZvdW5kYXRpb24ub3JnAAoJEHm+PkMAQRiGv+kIAKRpO7EuDokQL4qp
 hxEEaCMJA1T055EMlNU6FVAq/ZbmapzreUyNYiRMpPWKGTWNMkhIcZQfysYeGZz5
 y/KRxAiVxlcB+3v3yRmoZd/XoQmhgvJmqD4zhaGI2Utonow4f/SGSEFFZqqs9WND
 4HJROjZHgQ4JBxg9Z+QMo0FxbV/DCZpEOUq51N9WJywyyDRb18zotE83stpU+pE2
 fjqT7mk0NLrnYXuDRAbFC1Aau9ed4H6LlwLmxaqxq/Pt5Rz7wIKwKL9HIT4Dm/0a
 qpani6phhHWL7MwUpa2wkEonFCD03rJFl3DUVJo64Ijh4up5D/jyXQ+GKV2P4WKJ
 275Rb5Q=
 =WiZZ
 -----END PGP SIGNATURE-----

Merge tag 'v5.4-rc5' into rdma.git for-next

Linux 5.4-rc5

For dependencies in the next patches

Conflict resolved by keeping the delete of the unlock.

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2019-10-28 16:36:29 -03:00
Leon Romanovsky
24f5214923 RDMA/cm: Update copyright together with SPDX tag
Add Mellanox to lust of copyright holders and replace copyright
boilerplate with relevant SPDX tag.

Link: https://lore.kernel.org/r/20191020071559.9743-4-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2019-10-28 10:15:11 -03:00