Upon DEVX object creation the object must be destroyed upon a follows
error flow.

Fixes: 7efce369 ("IB/mlx5: Add obj create and destroy functionality")
Signed-off-by: NYishai Hadas <yishaih@mellanox.com>
Reviewed-by: NArtemy Kovalyov <artemyko@mellanox.com>
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

There are several blockable mmu notifiers which might sleep in
mmu_notifier_invalidate_range_start and that is a problem for the
oom_reaper because it needs to guarantee a forward progress so it cannot
depend on any sleepable locks.

Currently we simply back off and mark an oom victim with blockable mmu
notifiers as done after a short sleep.  That can result in selecting a new
oom victim prematurely because the previous one still hasn't torn its
memory down yet.

We can do much better though.  Even if mmu notifiers use sleepable locks
there is no reason to automatically assume those locks are held.  Moreover
majority of notifiers only care about a portion of the address space and
there is absolutely zero reason to fail when we are unmapping an unrelated
range.  Many notifiers do really block and wait for HW which is harder to
handle and we have to bail out though.

This patch handles the low hanging fruit.
__mmu_notifier_invalidate_range_start gets a blockable flag and callbacks
are not allowed to sleep if the flag is set to false.  This is achieved by
using trylock instead of the sleepable lock for most callbacks and
continue as long as we do not block down the call chain.

I think we can improve that even further because there is a common pattern
to do a range lookup first and then do something about that.  The first
part can be done without a sleeping lock in most cases AFAICS.

The oom_reaper end then simply retries if there is at least one notifier
which couldn't make any progress in !blockable mode.  A retry loop is
already implemented to wait for the mmap_sem and this is basically the
same thing.

The simplest way for driver developers to test this code path is to wrap
userspace code which uses these notifiers into a memcg and set the hard
limit to hit the oom.  This can be done e.g.  after the test faults in all
the mmu notifier managed memory and set the hard limit to something really
small.  Then we are looking for a proper process tear down.

[akpm@linux-foundation.org: coding style fixes]
[akpm@linux-foundation.org: minor code simplification]
Link: http://lkml.kernel.org/r/20180716115058.5559-1-mhocko@kernel.orgSigned-off-by: NMichal Hocko <mhocko@suse.com>
Acked-by: Christian König <christian.koenig@amd.com> # AMD notifiers
Acked-by: Leon Romanovsky <leonro@mellanox.com> # mlx and umem_odp
Reported-by: NDavid Rientjes <rientjes@google.com>
Cc: "David (ChunMing) Zhou" <David1.Zhou@amd.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Doug Ledford <dledford@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Mike Marciniszyn <mike.marciniszyn@intel.com>
Cc: Dennis Dalessandro <dennis.dalessandro@intel.com>
Cc: Sudeep Dutt <sudeep.dutt@intel.com>
Cc: Ashutosh Dixit <ashutosh.dixit@intel.com>
Cc: Dimitri Sivanich <sivanich@sgi.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Felix Kuehling <felix.kuehling@amd.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

mlx5_ib_create_qp_resp was never initialized and only the first 4 bytes
were written.

Fixes: 41d902cb ("RDMA/mlx5: Fix definition of mlx5_ib_create_qp_resp")
Cc: <stable@vger.kernel.org>
Acked-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Several handlers need temporary allocations for the life of the method,
switch them to use the uverbs_alloc allocator.
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>
Reviewed-by: NLeon Romanovsky <leonro@mellanox.com>

There is no reason for drivers to do this, the core code should take of
everything. The drivers will provide their information from rodata to
describe their modifications to the core's base uapi specification.

The core uses this to build up the runtime uapi for each device.
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>
Reviewed-by: NMichael J. Ruhl <michael.j.ruhl@intel.com>
Reviewed-by: NLeon Romanovsky <leonro@mellanox.com>

[   61.182439] UBSAN: Undefined behaviour in drivers/infiniband/hw/mlx5/qp.c:5366:34
[   61.183673] shift exponent 4294967288 is too large for 32-bit type 'unsigned int'
[   61.185530] CPU: 0 PID: 639 Comm: qp Not tainted 4.18.0-rc1-00037-g4aa1d69a9c60-dirty #96
[   61.186981] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-2.fc27 04/01/2014
[   61.188315] Call Trace:
[   61.188661]  dump_stack+0xc7/0x13b
[   61.190427]  ubsan_epilogue+0x9/0x49
[   61.190899]  __ubsan_handle_shift_out_of_bounds+0x1ea/0x22f
[   61.197040]  mlx5_ib_create_wq+0x1c99/0x1d50
[   61.206632]  ib_uverbs_ex_create_wq+0x499/0x820
[   61.213892]  ib_uverbs_write+0x77e/0xae0
[   61.248018]  vfs_write+0x121/0x3b0
[   61.249831]  ksys_write+0xa1/0x120
[   61.254024]  do_syscall_64+0x7c/0x2a0
[   61.256178]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[   61.259211] RIP: 0033:0x7f54bab70e99
[   61.262125] Code: 00 f3 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89
[   61.268678] RSP: 002b:00007ffe1541c318 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[   61.271076] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f54bab70e99
[   61.273795] RDX: 0000000000000070 RSI: 0000000020000240 RDI: 0000000000000003
[   61.276982] RBP: 00007ffe1541c330 R08: 00000000200078e0 R09: 0000000000000002
[   61.280035] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004005c0
[   61.283279] R13: 00007ffe1541c420 R14: 0000000000000000 R15: 0000000000000000

Cc: <stable@vger.kernel.org> # 4.7
Fixes: 79b20a6c ("IB/mlx5: Add receive Work Queue verbs")
Cc: syzkaller <syzkaller@googlegroups.com>
Reported-by: NNoa Osherovich <noaos@mellanox.com>
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Now that the unregister_netdev flow for IPoIB no longer relies on external
code we can now introduce the use of priv_destructor and
needs_free_netdev.

The rdma_netdev flow is switched to use the netdev common priv_destructor
instead of the special free_rdma_netdev and the IPOIB ULP adjusted:
 - priv_destructor needs to switch to point to the ULP's destructor
   which will then call the rdma_ndev's in the right order
 - We need to be careful around the error unwind of register_netdev
   as it sometimes calls priv_destructor on failure
 - ULPs need to use ndo_init/uninit to ensure proper ordering
   of failures around register_netdev

Switching to priv_destructor is a necessary pre-requisite to using
the rtnl new_link mechanism.

The VNIC user for rdma_netdev should also be revised, but that is left for
another patch.
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>
Signed-off-by: NDenis Drozdov <denisd@mellanox.com>
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>

This does the same as the patch before, except for ioctl. The rules are
the same, but for the ioctl methods the core code handles setting up the
uobject.

- Retrieve the ib_dev from the uobject->context->device. This is
  safe under ioctl as the core has already done rdma_alloc_begin_uobject
  and so CREATE calls are entirely protected by the rwsem.
- Retrieve the ib_dev from uobject->object
- Call ib_uverbs_get_ucontext()
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

The proper return code is "-EOPNOTSUPP" when the modify_cq() callback is
not supported, all drivers should generate this and all users should check
for it when detecting not supported functionality.
Signed-off-by: NKamal Heib <kamalheib1@gmail.com>
Acked-by: Leon Romanovsky <leonro@mellanox.com> (for mlx5)
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

This clearly indicates that the input is a bitwise combination of values
in an enum, and identifies which enum contains the definition of the bits.

Special accessors are provided that handle the mandatory validation of the
allowed bits and enforce the correct type for bitwise flags.

If we had introduced this at the start then the kabi would have uniformly
used u64 data to pass flags, however today there is a mixture of u64 and
u32 flags. All places are converted to accept both sizes and the accessor
fixes it. This allows all existing flags to grow to u64 in future without
any hassle.

Finally all flags are, by definition, optional. If flags are not passed
the accessor does not fail, but provides a value of zero.
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>
Reviewed-by: NLeon Romanovsky <leonro@mellanox.com>

Since neither ib_post_send() nor ib_post_recv() modify the data structure
their second argument points at, declare that argument const. This change
makes it necessary to declare the 'bad_wr' argument const too and also to
modify all ULPs that call ib_post_send(), ib_post_recv() or
ib_post_srq_recv(). This patch does not change any functionality but makes
it possible for the compiler to verify whether the
ib_post_(send|recv|srq_recv) really do not modify the posted work request.

To make this possible, only one cast had to be introduce that casts away
constness, namely in rpcrdma_post_recvs(). The only way I can think of to
avoid that cast is to introduce an additional loop in that function or to
change the data type of bad_wr from struct ib_recv_wr ** into int
(an index that refers to an element in the work request list). However,
both approaches would require even more extensive changes than this
patch.
Signed-off-by: NBart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Since the next patch will constify the wr pointer, do not modify the data
that pointer points at.
Signed-off-by: NBart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Cc: Saeed Mahameed <saeedm@mellanox.com>
Acked-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

When posting a send work request, the work request that is posted is not
modified by any of the RDMA drivers. Make this explicit by constifying
most ib_send_wr pointers in RDMA transport drivers.
Signed-off-by: NBart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NSteve Wise <swise@opengridcomputing.com>
Reviewed-by: NDennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

When a CX5 device is configured in dual-port RoCE mode, after creating
many VFs against port 1, creating the same number of VFs against port 2
will flood kernel/syslog with something like
"mlx5_*:mlx5_ib_bind_slave_port:4266:(pid 5269): port 2 already
affiliated."

So basically, when traversing mlx5_ib_dev_list, mlx5_ib_add_slave_port()
repeatedly attempts to bind the new mpi structure to every device on the
list until it finds an unbound device.

Change the log level from warn to dbg to avoid log flooding as the warning
should be harmless.
Signed-off-by: NQing Huang <qing.huang@oracle.com>
Reviewed-by: NDaniel Jurgens <danielj@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

We have a parallel unlocked reader and writer with ib_uverbs_get_context()
vs everything else, and nothing guarantees this works properly.

Audit and fix all of the places that access ucontext to use one of the
following locking schemes:
- Call ib_uverbs_get_ucontext() under SRCU and check for failure
- Access the ucontext through an struct ib_uobject context member
  while holding a READ or WRITE lock on the uobject.
  This value cannot be NULL and has no race.
- Hold the ucontext_lock and check for ufile->ucontext !NULL

This also re-implements ib_uverbs_get_ucontext() in a way that is safe
against concurrent ib_uverbs_get_context() and disassociation.

As a side effect, every access to ucontext in the commands is via
ib_uverbs_get_context() with an error check, or via the uobject, so there
is no longer any need for the core code to check ucontext on every command
call. These checks are also removed.
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

This approach matches the standard flow of the typical write method that
relies on the HW object to store the device and the uobject to access the
ucontext.  Avoids the use of the devx_ufile2uctx in several places will
make revising the semantics of ib_uverbs_get_ucontext() in the next patch
simpler.
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Expose the mlx5 flow steering parsing trees, exposing the functionality to
user space.
Signed-off-by: NYishai Hadas <yishaih@mellanox.com>
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Add support to set a destination that is a flow table, this can come from
the DEVX destination.
Signed-off-by: NYishai Hadas <yishaih@mellanox.com>
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Add support to set a public flow steering rule when its destination is a
TIR by using raw specification data.

The logic follows the verbs API but instead of using ib_spec(s) the raw,
device specific, description is used.

This allows supporting specialty matchers without having to define new
matches in the verbs struct based language.
Signed-off-by: NYishai Hadas <yishaih@mellanox.com>
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Introduce driver create and destroy flow methods on the uverbs flow
object.

This allows the driver to get its specific device attributes to match the
underlay specification while still using the generic ib_flow object for
cleanup and code sharing.

The IB object's attributes are set via the ib_set_flow() helper function.

The specific implementation for the given specification is added in
downstream patches.
Signed-off-by: NYishai Hadas <yishaih@mellanox.com>
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Introduce flow steering matcher object and its create and destroy methods.

This matcher object holds some mlx5 specific driver properties that
matches the underlay device specification when an mlx5 flow steering group
is created.

It will be used in downstream patches to be part of mlx5 specific create
flow method.
Signed-off-by: NYishai Hadas <yishaih@mellanox.com>
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Remove "uctx" and "pa" variables that were set but not used.

Fixes: a8b92ca1 ("IB/mlx5: Introduce DEVX")
Fixes: 8f062287 ("RDMA/mlx5: Remove debug prints of VMA pointers")
Signed-off-by: NKamal Heib <kamalheib1@gmail.com>
Acked-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Current description did not include new devices. Fix that by proving the
correct generic description.
Signed-off-by: NEran Ben Elisha <eranbe@mellanox.com>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>

User's supplied index is checked again total number of system pages, but
this number already includes num_static_sys_pages, so addition of that
value to supplied index causes to below error while trying to access
sys_pages[].

BUG: KASAN: slab-out-of-bounds in bfregn_to_uar_index+0x34f/0x400
Read of size 4 at addr ffff880065561904 by task syz-executor446/314

CPU: 0 PID: 314 Comm: syz-executor446 Not tainted 4.18.0-rc1+ #256
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.0-0-g63451fca13-prebuilt.qemu-project.org 04/01/2014
Call Trace:
 dump_stack+0xef/0x17e
 print_address_description+0x83/0x3b0
 kasan_report+0x18d/0x4d0
 bfregn_to_uar_index+0x34f/0x400
 create_user_qp+0x272/0x227d
 create_qp_common+0x32eb/0x43e0
 mlx5_ib_create_qp+0x379/0x1ca0
 create_qp.isra.5+0xc94/0x22d0
 ib_uverbs_create_qp+0x21b/0x2a0
 ib_uverbs_write+0xc2c/0x1010
 vfs_write+0x1b0/0x550
 ksys_write+0xc6/0x1a0
 do_syscall_64+0xa7/0x590
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x433679
Code: fd ff 48 81 c4 80 00 00 00 e9 f1 fe ff ff 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 3b 91 fd ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fff2b3d8e48 EFLAGS: 00000217 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00000000004002f8 RCX: 0000000000433679
RDX: 0000000000000040 RSI: 0000000020000240 RDI: 0000000000000003
RBP: 00000000006d4018 R08: 00000000004002f8 R09: 00000000004002f8
R10: 00000000004002f8 R11: 0000000000000217 R12: 0000000000000000
R13: 000000000040cb00 R14: 000000000040cb90 R15: 0000000000000006

Allocated by task 314:
 kasan_kmalloc+0xa0/0xd0
 __kmalloc+0x1a9/0x510
 mlx5_ib_alloc_ucontext+0x966/0x2620
 ib_uverbs_get_context+0x23f/0xa60
 ib_uverbs_write+0xc2c/0x1010
 __vfs_write+0x10d/0x720
 vfs_write+0x1b0/0x550
 ksys_write+0xc6/0x1a0
 do_syscall_64+0xa7/0x590
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 1:
 __kasan_slab_free+0x12e/0x180
 kfree+0x159/0x630
 kvfree+0x37/0x50
 single_release+0x8e/0xf0
 __fput+0x2d8/0x900
 task_work_run+0x102/0x1f0
 exit_to_usermode_loop+0x159/0x1c0
 do_syscall_64+0x408/0x590
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff880065561100
 which belongs to the cache kmalloc-4096 of size 4096
The buggy address is located 2052 bytes inside of
 4096-byte region [ffff880065561100, ffff880065562100)
The buggy address belongs to the page:
page:ffffea0001955800 count:1 mapcount:0 mapping:ffff88006c402480 index:0x0 compound_mapcount: 0
flags: 0x4000000000008100(slab|head)
raw: 4000000000008100 ffffea0001a7c000 0000000200000002 ffff88006c402480
raw: 0000000000000000 0000000080070007 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff880065561800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff880065561880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff880065561900: 04 fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                   ^
 ffff880065561980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff880065561a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc

Cc: <stable@vger.kernel.org> # 4.15
Fixes: 1ee47ab3 ("IB/mlx5: Enable QP creation with a given blue flame index")
Reported-by: NNoa Osherovich <noaos@mellanox.com>
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

There is no need for three consecutive calls to alloc_bfreg(). It can be
implemented with one function.
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Fix memory leak in the error path of mlx5_ib_create_srq() by making sure
to free the allocated srq.

Fixes: c2b37f76 ("IB/mlx5: Fix integer overflows in mlx5_ib_create_srq")
Signed-off-by: NKamal Heib <kamalheib1@gmail.com>
Acked-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Enable uverbs_destroy_def_handler to be used by drivers and replace
current code to use it.
Signed-off-by: NYishai Hadas <yishaih@mellanox.com>
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Extend the existing grh_required flag to check when AV's are handled that
a GRH is present.

Since we don't want to do query_port during the AV checks for performance
reasons move the flag into the immutable_data.
Signed-off-by: NArtemy Kovalyov <artemyko@mellanox.com>
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

The internal flag IP_BASED_GIDS was added to a field that was being used
to hold the port Info CapabilityMask without considering the effects this
will have. Since most drivers just use the value from the HW MAD it means
IP_BASED_GIDS will also become set on any HW that sets the IBA flag
IsOtherLocalChangesNoticeSupported - which is not intended.

Fix this by keeping port_cap_flags only for the IBA CapabilityMask value
and store unrelated flags externally. Move the bit definitions for this to
ib_mad.h to make it clear what is happening.

To keep the uAPI unchanged define a new set of flags in the uapi header
that are only used by ib_uverbs_query_port_resp.port_cap_flags which match
the current flags supported in rdma-core, and the values exposed by the
current kernel.

Fixes: b4a26a27 ("IB: Report using RoCE IP based gids in port caps")
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>
Signed-off-by: NArtemy Kovalyov <artemyko@mellanox.com>
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>

It is incorrect to depend on set_id value to know if counters were
allocated or not. set_id_valid field is set to true when counters
were allocated. Therefore, use set_id_valid while deciding to
free counters.

Cc: <stable@vger.kernel.org> # 4.15
Fixes: aac4492e ("IB/mlx5: Update counter implementation for dual port RoCE")
Signed-off-by: NParav Pandit <parav@mellanox.com>
Reviewed-by: NDaniel Jurgens <danielj@mellanox.com>
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Clean up a little bit code to drop unused port_num parameter.
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

In general, accessing userspace memory beyond the length of the supplied
buffer in VFS read/write handlers can lead to both kernel memory corruption
(via kernel_read()/kernel_write(), which can e.g. be triggered via
sys_splice()) and privilege escalation inside userspace.

In this case, the affected files are in debugfs (and should therefore only
be accessible to root), and the read handlers check that *pos is zero
(meaning that at least sys_splice() can't trigger kernel memory
corruption). Because of the root requirement, this is not a security fix,
but rather a cleanup.

For the read handlers, fix it by using simple_read_from_buffer() instead
of custom logic. Add min() calls to the write handlers.

Fixes: 4a2da0b8 ("IB/mlx5: Add debug control parameters for congestion control")
Fixes: e126ba97 ("mlx5: Add driver for Mellanox Connect-IB adapters")
Signed-off-by: NJann Horn <jannh@google.com>
Reviewed-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

This newer macro allows specifying a lower bound on the accepted size, and
has an 'unlimited' upper bound. Due to this it never checks for trailing
zeroing so it doesn't make any sense to combine it with MIN_SZ_OR_ZERO, so
drop MIN_SZ_OR_ZERO when they are used together

There were a couple of places that open coded this pattern, switch them to
use the clearer UVERBS_ATTR_MIN_SIZE for clarity.
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>

This bit of boilerplate isn't really necessary, we can use bitfields
instead of a flags enum and the macros can then individually initialize
them through the __VA_ARGS__ like everything else.
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>

Hide it inside the macros. The & is confusing and interferes with using
this as a generic DSL in later patches.

Since this also touches almost every line, also run the specs through
clang-format (with 'BinPackParameters: false') to make the maintenance
easier.
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>

Instead of the large set of indirecting macros, define the few needed
macros to directly instantiate the struct uverbs_oject_tree_def and
associated objects list.

This is small amount of code duplication but the readability is far
better.
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>

Instead of the large set of indirecting macros, define the few needed
macros to directly instantiate the struct uverbs_method_def and associated
attributes list.

This is small amount of code duplication but the readability is far
better.
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>

Instead of using a complex cascade of macros, just directly provide the
initializer list each of the declarations is trying to create.

Now that the macros are simplified this also reworks the uverbs_attr_spec
to be friendly to older compilers by eliminating any unnamed
structures/unions inside, and removing the duplication of some fields. The
structure size remains at 16 bytes which was the original motivation for
some of this oddness.
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>

The specs are required to operate the uverbs file, so they belong inside
the ib_uverbs_device, not inside the ib_device. The spec passed in the
ib_device is just a communication from the driver and should not be used
during runtime.

This also changes the lifetime of the spec memory to match the
ib_uverbs_device, however at this time the spec_root can still contain
driver pointers after disassociation, so it cannot be used if ib_dev is
NULL. This is preparation for another series.
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>
Reviewed-by: NMichael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>

MLX5 IB HCA offers the memory key, dump_fill_mkey to boost
performance, when used in a send or receive operations.

It is used to force local HCA operations to skip the PCI bus access,
while keeping track of the processed length in the ibv_sge handling.

Meaning, instead of a PCI write access the HCA leaves the target
memory untouched, and skips filling that packet section. Similar
behavior is done upon send, the HCA skips data in memory relevant
to this key and saves PCI bus access.

This functionality saves PCI read/write operations.
Signed-off-by: NYonatan Cohen <yonatanc@mellanox.com>
Reviewed-by: NYishai Hadas <yishaih@mellanox.com>
Reviewed-by: NGuy Levi <guyle@mellanox.com>
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>