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path: root/drivers/infiniband/core/rdma_core.c (follow)
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2018-09-21RDMA/uverbs: Get rid of ucontext->tgidJason Gunthorpe1-1/+0
Nothing uses this now, just delete it. Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> Signed-off-by: Leon Romanovsky <leonro@mellanox.com> Signed-off-by: Doug Ledford <dledford@redhat.com>
2018-09-20RDMA/ucontext: Get rid of the old disassociate flowJason Gunthorpe1-41/+10
The disassociate_ucontext function in every driver is now empty, so we don't need this ugly and wrong code that was messing with tgids. rdma_user_mmap_io does this same work in a better way. Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> Signed-off-by: Leon Romanovsky <leonro@mellanox.com> Signed-off-by: Doug Ledford <dledford@redhat.com>
2018-09-20RDMA/ucontext: Add a core API for mmaping driver IO memoryJason Gunthorpe1-1/+3
To support disassociation and PCI hot unplug, we have to track all the VMAs that refer to the device IO memory. When disassociation occurs the VMAs have to be revised to point to the zero page, not the IO memory, to allow the physical HW to be unplugged. The three drivers supporting this implemented three different versions of this algorithm, all leaving something to be desired. This new common implementation has a few differences from the driver versions: - Track all VMAs, including splitting/truncating/etc. Tie the lifetime of the private data allocation to the lifetime of the vma. This avoids any tricks with setting vm_ops which Linus didn't like. (see link) - Support multiple mms, and support properly tracking mmaps triggered by processes other than the one first opening the uverbs fd. This makes fork behavior of disassociation enabled drivers the same as fork support in normal drivers. - Don't use crazy get_task stuff. - Simplify the approach for to racing between vm_ops close and disassociation, fixing the related bugs most of the driver implementations had. Since we are in core code the tracking list can be placed in struct ib_uverbs_ufile, which has a lifetime strictly longer than any VMAs created by mmap on the uverbs FD. Link: https://www.spinics.net/lists/stable/msg248747.html Link: https://lkml.kernel.org/r/CA+55aFxJTV_g46AQPoPXen-UPiqR1HGMZictt7VpC-SMFbm3Cw@mail.gmail.com Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> Signed-off-by: Leon Romanovsky <leonro@mellanox.com> Signed-off-by: Doug Ledford <dledford@redhat.com>
2018-09-04IB/core: Release object lock if destroy failedArtemy Kovalyov1-0/+2
The object lock was supposed to always be released during destroy, but when the destruction retry series was integrated with the destroy series it created a failure path that missed the unlock. Keep with convention, if destroy fails the caller must undo all locking. Fixes: 87ad80abc70d ("IB/uverbs: Consolidate uobject destruction") Signed-off-by: Artemy Kovalyov <artemyko@mellanox.com> Signed-off-by: Leon Romanovsky <leonro@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-08-16Merge branch 'linus/master' into rdma.git for-nextJason Gunthorpe1-1/+1
rdma.git merge resolution for the 4.19 merge window Conflicts: drivers/infiniband/core/rdma_core.c - Use the rdma code and revise with the new spelling for atomic_fetch_add_unless drivers/nvme/host/rdma.c - Replace max_sge with max_send_sge in new blk code drivers/nvme/target/rdma.c - Use the blk code and revise to use NULL for ib_post_recv when appropriate - Replace max_sge with max_recv_sge in new blk code net/rds/ib_send.c - Use the net code and revise to use NULL for ib_post_recv when appropriate Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-08-13IB/uverbs: Remove struct uverbs_root_spec and all supporting codeJason Gunthorpe1-45/+0
Everything now uses the uverbs_uapi data structure. Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-08-10IB/uverbs: Use uverbs_api to manage the object type inside the uobjectJason Gunthorpe1-45/+55
Currently the struct uverbs_obj_type stored in the ib_uobject is part of the .rodata segment of the module that defines the object. This is a problem if drivers define new uapi objects as we will be left with a dangling pointer after device disassociation. Switch the uverbs_obj_type for struct uverbs_api_object, which is allocated memory that is part of the uverbs_api and is guaranteed to always exist. Further this moves the 'type_class' into this memory which means access to the IDR/FD function pointers is also guaranteed. Drivers cannot define new types. This makes it safe to continue to use all uobjects, including driver defined ones, after disassociation. Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-08-01IB/uverbs: Allow all DESTROY commands to succeed after disassociateJason Gunthorpe1-11/+55
The disassociate function was broken by design because it failed all commands. This prevents userspace from calling destroy on a uobject after it has detected a device fatal error and thus reclaiming the resources in userspace is prevented. This fix is now straightforward, when anything destroys a uobject that is not the user the object remains on the IDR with a NULL context and object pointer. All lookup locking modes other than DESTROY will fail. When the user ultimately calls the destroy function it is simply dropped from the IDR while any related information is returned. Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-08-01IB/uverbs: Lower the test for ongoing disassociationJason Gunthorpe1-0/+11
Commands that are reading/writing to objects can test for an ongoing disassociation during their initial call to rdma_lookup_get_uobject. This directly prevents all of these commands from conflicting with an ongoing disassociation. Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-08-01IB/uverbs: Allow uobject allocation to work concurrently with disassociateJason Gunthorpe1-11/+26
After all the recent structural changes this is now straightforward, hold the hw_destroy_rwsem across the entire uobject creation. We already take this semaphore on the success path, so holding it a bit longer is not going to change the performance. After this change none of the create callbacks require the disassociate_srcu lock to be correct. Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-08-01IB/uverbs: Allow RDMA_REMOVE_DESTROY to work concurrently with disassociateJason Gunthorpe1-22/+49
After all the recent structural changes this is now straightfoward, hoist the hw_destroy_rwsem up out of rdma_destroy_explicit and wrap it around the uobject write lock as well as the destroy. This is necessary as obtaining a write lock concurrently with uverbs_destroy_ufile_hw() will cause malfunction. After this change none of the destroy callbacks require the disassociate_srcu lock to be correct. This requires introducing a new lookup mode, UVERBS_LOOKUP_DESTROY as the IOCTL interface needs to hold an unlocked kref until all command verification is completed. Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-08-01IB/uverbs: Convert 'bool exclusive' into an enumJason Gunthorpe1-37/+57
This is more readable, and future patches will need a 3rd lookup type. Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-08-01IB/uverbs: Consolidate uobject destructionJason Gunthorpe1-129/+122
There are several flows that can destroy a uobject and each one is minimized and sprinkled throughout the code base, making it difficult to understand and very hard to modify the destroy path. Consolidate all of these into uverbs_destroy_uobject() and call it in all cases where a uobject has to be destroyed. This makes one change to the lifecycle, during any abort (eg when alloc_commit is not called) we always call out to alloc_abort, even if remove_commit needs to be called to delete a HW object. This also renames RDMA_REMOVE_DURING_CLEANUP to RDMA_REMOVE_ABORT to clarify its actual usage and revises some of the comments to reflect what the life cycle is for the type implementation. Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-08-01IB/uverbs: Make the write path destroy methods use the same flow as ioctlJason Gunthorpe1-24/+29
The ridiculous dance with uobj_remove_commit() is not needed, the write path can follow the same flow as ioctl - lock and destroy the HW object then use the data left over in the uobject to form the response to userspace. Two helpers are introduced to make this flow straightforward for the caller. Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-08-01IB/uverbs: Remove rdma_explicit_destroy() from the ioctl methodsJason Gunthorpe1-4/+1
The core code will destroy the HW object on behalf of the method, if the method provides an implementation it must simply copy data from the stub uobj into the response. Destroy methods cannot touch the HW object. Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-07-25IB/uverbs: Fix locking around struct ib_uverbs_file ucontextJason Gunthorpe1-4/+10
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: Jason Gunthorpe <jgg@mellanox.com>
2018-07-25IB/uverbs: Move the FD uobj type struct file allocation to alloc_commitJason Gunthorpe1-37/+46
Allocating the struct file during alloc_begin creates this strange asymmetry with IDR, where the FD has two krefs pointing at it during the pre-commit phase. In particular this makes the abort process for FD very strange and confusing. For instance abort currently calls the type's destroy_object twice, and the fops release once if abort is done. This is very counter intuitive. No fops should be called until alloc_commit succeeds, and destroy_object should only ever be called once. Moving the struct file allocation to the alloc_commit is now simple, as we already support failure of rdma_alloc_commit_uobject, with all the required rollback pieces. This creates an understandable symmetry with IDR and simplifies/fixes the abort handling for FD types. Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-07-25IB/uverbs: Always propagate errors from rdma_alloc_commit_uobject()Jason Gunthorpe1-2/+3
The ioctl framework already does this correctly, but the write path did not. This is trivially fixed by simply using a standard pattern to return uobj_alloc_commit() as the last statement in every function. Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-07-25IB/uverbs: Rework the locking for cleaning up the ucontextJason Gunthorpe1-13/+104
The locking here has always been a bit crazy and spread out, upon some careful analysis we can simplify things. Create a single function uverbs_destroy_ufile_hw() that internally handles all locking. This pulls together pieces of this process that were sprinkled all over the places into one place, and covers them with one lock. This eliminates several duplicate/confusing locks and makes the control flow in ib_uverbs_close() and ib_uverbs_free_hw_resources() extremely simple. Unfortunately we have to keep an extra mutex, ucontext_lock. This lock is logically part of the rwsem and provides the 'down write, fail if write locked, wait if read locked' semantic we require. Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-07-25IB/uverbs: Revise and clarify the rwsem and uobjects_lockJason Gunthorpe1-14/+12
Rename 'cleanup_rwsem' to 'hw_destroy_rwsem' which is held across any call to the type destroy function (aka 'hw' destroy). The main purpose of this lock is to prevent normal add and destroy from running concurrently with uverbs_cleanup_ufile() Since the uobjects list is always manipulated under the 'hw_destroy_rwsem' we can eliminate the uobjects_lock in the cleanup function. This allows converting that lock to a very simple spinlock with a narrow critical section. Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-07-25IB/uverbs: Clarify and revise uverbs_close_fdJason Gunthorpe1-13/+28
The locking requirements here have changed slightly now that we can rely on the ib_uverbs_file always existing and containing all the necessary locking infrastructure. That means we can get rid of the cleanup_mutex usage (this was protecting the check on !uboj->context). Otherwise, follow the same pattern that IDR uses for destroy, acquire exclusive write access, then call destroy and the undo the 'lookup'. Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-07-25IB/uverbs: Revise the placement of get/puts on uobjectJason Gunthorpe1-33/+50
This wasn't wrong, but the placement of two krefs didn't make any sense. Follow some simple rules. - A kref is held inside uobjects_list - A kref is held inside the IDR - A kref is held inside file->private - A stack based kref is passed bettwen alloc_begin and alloc_abort/alloc_commit Any place we destroy one of the above pointers, we stick a put, or 'move' the kref into another pointer. The key functions have sensible semantics: - alloc_uobj fully initializes the common members in uobj, including the list - Get rid of the uverbs_idr_remove_uobj helper since IDR remove does require put, but it depends on the situation. Later patches will re-consolidate this differently. - alloc_abort always consumes the passed kref, done in the type - alloc_commit always consumes the passed kref, done in the type - rdma_remove_commit_uobject always pairs with a lookup_get After it is all done the only control flow change is to: - move a get from alloc_commit_fd_uobject to rdma_alloc_commit_uobject - add a put to remove_commit_idr_uobject - Consistenly use rdma_lookup_put in rdma_remove_commit_uobject at the right place Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-07-25IB/uverbs: Clarify the kref'ing ordering for alloc_commitJason Gunthorpe1-4/+22
The alloc_commit callback makes the uobj visible to other threads, and it does so using a 'move' semantic of the uobj kref on the stack into the public storage (eg the IDR, uobject list and file_private_data) Once this is done another thread could start up and trigger deletion of the kref. Fortunately cleanup_rwsem happens to prevent this from being a bug, but that is a fantastically unclear side effect. Re-organize things so that alloc_commit is that last thing to touch the uobj, get rid of the sneaky implicit dependency on cleanup_rwsem, and add a comment reminding that uobj is no longer kref'd after alloc_commit. Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-07-25IB/uverbs: Handle IDR and FD types without truncationJason Gunthorpe1-7/+15
Our ABI for write() uses a s32 for FDs and a u32 for IDRs, but internally we ended up implicitly casting these ABI values into an 'int'. For ioctl() we use a s64 for FDs and a u64 for IDRs, again casting to an int. The various casts to int are all missing range checks which can cause userspace values that should be considered invalid to be accepted. Fix this by making the generic lookup routine accept a s64, which does not truncate the write API's u32/s32 or the ioctl API's s64. Then push the detailed range checking down to the actual type implementations to be shared by both interfaces. Finally, change the copy of the uobj->id to sign extend into a s64, so eg, if we ever wish to return a negative value for a FD it is carried properly. This ensures that userspace values are never weirdly interpreted due to the various trunctations and everything that is really out of range gets an EINVAL. Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-07-25IB/uverbs: Get rid of null_obj_typeJason Gunthorpe1-32/+9
If the method fails after calling rdma_explicit_destroy (eg if copy_to_user faults) then it will trigger a kernel oops: BUG: unable to handle kernel NULL pointer dereference at 0000000000000000 PGD 800000000548d067 P4D 800000000548d067 PUD 54a0067 PMD 0 SMP PTI CPU: 0 PID: 359 Comm: ibv_rc_pingpong Not tainted 4.18.0-rc1+ #28 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org 04/01/2014 RIP: 0010: (null) Code: Bad RIP value. RSP: 0018:ffffc900001a3bf0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff88000603bd00 RCX: 0000000000000003 RDX: 0000000000000001 RSI: 0000000000000001 RDI: ffff88000603bd00 RBP: 0000000000000001 R08: ffffc900001a3cf8 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffffc900001a3cf0 R13: 0000000000000000 R14: ffffc900001a3cf0 R15: 0000000000000000 FS: 00007fb00dda8700(0000) GS:ffff880007c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 000000000548e004 CR4: 00000000003606b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ? rdma_lookup_put_uobject+0x22/0x50 [ib_uverbs] ? uverbs_finalize_object+0x3b/0x60 [ib_uverbs] ? uverbs_finalize_attrs+0x128/0x140 [ib_uverbs] ? ib_uverbs_cmd_verbs+0x698/0x7c0 [ib_uverbs] ? find_held_lock+0x2d/0x90 ? __might_fault+0x39/0x90 ? ib_uverbs_ioctl+0x111/0x1f0 [ib_uverbs] ? do_vfs_ioctl+0xa0/0x6d0 ? trace_hardirqs_on_caller+0xed/0x180 ? _raw_spin_unlock_irq+0x24/0x40 ? syscall_trace_enter+0x138/0x1d0 ? ksys_ioctl+0x35/0x60 ? __x64_sys_ioctl+0x11/0x20 ? do_syscall_64+0x5b/0x1c0 ? entry_SYSCALL_64_after_hwframe+0x49/0xbe This is because the type was replaced with the null_type during explicit destroy that cannot complete the destruction. One of the side effects of replacing the type is to make the object handle totally unreachable - so no other command could attempt to use it, even though it remains on the uboject list. We can get the same end result by just fully destroying the object inside rdma_explicit_destroy and leaving the caller the residual kref for the uobj with no attached HW object, and no presence in the ubojects list. Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
2018-07-09IB/uverbs: Remove ib_uobject_fileJason Gunthorpe1-28/+19
The only purpose for this structure was to hold the ib_uobject_file pointer, but now that is part of the standard ib_uobject the structure no longer makes any sense, so get rid of it. Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
2018-07-09IB/uverbs: Tidy up remaining references to ucontextJason Gunthorpe1-10/+9
Unnecessary clutter, to indirect through ucontext when the ufile would do. Generally most of the code code should only be working with ufile, except for a few places that touch the driver interface. Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
2018-07-09IB/uverbs: Replace ib_ucontext with ib_uverbs_file in core function callsJason Gunthorpe1-34/+32
The correct handle to refer to the idr/etc is ib_uverbs_file, revise all the core APIs to use this instead. The user API are left as wrappers that automatically convert a ucontext to a ufile for now. Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
2018-07-09IB/uverbs: Move non driver related elements from ib_ucontext to ib_ufileJason Gunthorpe1-38/+34
The IDR is part of the ib_ufile so all the machinery to lock it, handle closing and disassociation rightly belongs to the ufile not the ucontext. This changes the lifetime of that data to match the lifetime of the file descriptor which is always strictly longer than the lifetime of the ucontext. We need the entire locking machinery to continue to exist after ucontext destruction to allow us to return the destroy data after a device has been disassociated. Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
2018-07-09IB/uverbs: Add a uobj_perform_destroy helperJason Gunthorpe1-0/+22
This consolidates a bunch of repeated code patterns into a helper. Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
2018-07-04RDMA/uverbs: Store the specs_root in the struct ib_uverbs_deviceJason Gunthorpe1-2/+2
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: Jason Gunthorpe <jgg@mellanox.com> Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com> Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
2018-06-29IB: Improve uverbs_cleanup_ucontext algorithmYishai Hadas1-48/+65
Improve uverbs_cleanup_ucontext algorithm to work properly when the topology graph of the objects cannot be determined at compile time. This is the case with objects created via the devx interface in mlx5. Typically uverbs objects must be created in a strict topologically sorted order, so that LIFO ordering will generally cause them to be freed properly. There are only a few cases (eg memory windows) where objects can point to things out of the strict LIFO order. Instead of using an explicit ordering scheme where the HW destroy is not allowed to fail, go over the list multiple times and allow the destroy function to fail. If progress halts then a final, desperate, cleanup is done before leaking the memory. This indicates a driver bug. Signed-off-by: Yishai Hadas <yishaih@mellanox.com> Signed-off-by: Leon Romanovsky <leonro@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-06-21atomics/treewide: Rename __atomic_add_unless() => atomic_fetch_add_unless()Mark Rutland1-1/+1
While __atomic_add_unless() was originally intended as a building-block for atomic_add_unless(), it's now used in a number of places around the kernel. It's the only common atomic operation named __atomic*(), rather than atomic_*(), and for consistency it would be better named atomic_fetch_add_unless(). This lack of consistency is slightly confusing, and gets in the way of scripting atomics. Given that, let's clean things up and promote it to an official part of the atomics API, in the form of atomic_fetch_add_unless(). This patch converts definitions and invocations over to the new name, including the instrumented version, using the following script: ---- git grep -w __atomic_add_unless | while read line; do sed -i '{s/\<__atomic_add_unless\>/atomic_fetch_add_unless/}' "${line%%:*}"; done git grep -w __arch_atomic_add_unless | while read line; do sed -i '{s/\<__arch_atomic_add_unless\>/arch_atomic_fetch_add_unless/}' "${line%%:*}"; done ---- Note that we do not have atomic{64,_long}_fetch_add_unless(), which will be introduced by later patches. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Will Deacon <will.deacon@arm.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Palmer Dabbelt <palmer@sifive.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/lkml/20180621121321.4761-2-mark.rutland@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-06-19IB/uverbs: Refactor uverbs_finalize_objectsMatan Barak1-40/+0
uverbs_finalize_objects is currently used only to commit or abort objects. Since we want to add automatic allocation/free of PTR_IN attributes, moving it to uverbs_ioctl.c and renamit it to uverbs_finalize_attrs. Signed-off-by: Matan Barak <matanb@mellanox.com> Signed-off-by: Leon Romanovsky <leonro@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-06-19IB/uverbs: Export uverbs idr and fd typesMatan Barak1-0/+2
As provider drivers could use UVERBS_ATTR_FD and UVERBS_ATTR_IDR macros need to export them. Signed-off-by: Matan Barak <matanb@mellanox.com> Signed-off-by: Yishai Hadas <yishaih@mellanox.com> Signed-off-by: Leon Romanovsky <leonro@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-02-28IB/uverbs: Tidy uverbs_uobject_addJason Gunthorpe1-9/+4
Maintaining the uobjects list is mandatory, hoist it into the common rdma_alloc_commit_uobject() function and inline it as there is now only one caller. Signed-off-by: Leon Romanovsky <leon@kernel.org> Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-02-15IB/uverbs: Fix unbalanced unlock on error path for rdma_explicit_destroyJason Gunthorpe1-2/+3
If remove_commit fails then the lock is left locked while the uobj still exists. Eventually the kernel will deadlock. lockdep detects this and says: test/4221 is leaving the kernel with locks still held! 1 lock held by test/4221: #0: (&ucontext->cleanup_rwsem){.+.+}, at: [<000000001e5c7523>] rdma_explicit_destroy+0x37/0x120 [ib_uverbs] Fixes: 4da70da23e9b ("IB/core: Explicitly destroy an object while keeping uobject") Signed-off-by: Leon Romanovsky <leon@kernel.org> Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-02-15IB/uverbs: Improve lockdep_checkJason Gunthorpe1-7/+7
This is really being used as an assert that the expected usecnt is being held and implicitly that the usecnt is valid. Rename it to assert_uverbs_usecnt and tighten the checks to only accept valid values of usecnt (eg 0 and < -1 are invalid). The tigher checkes make the assertion cover more cases and is more likely to find bugs via syzkaller/etc. Fixes: 3832125624b7 ("IB/core: Add support for idr types") Signed-off-by: Leon Romanovsky <leon@kernel.org> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-02-15RDMA/uverbs: Protect from races between lookup and destroy of uobjectsLeon Romanovsky1-1/+9
The race is between lookup_get_idr_uobject and uverbs_idr_remove_uobj -> uverbs_uobject_put. We deliberately do not call sychronize_rcu after the idr_remove in uverbs_idr_remove_uobj for performance reasons, instead we call kfree_rcu() during uverbs_uobject_put. However, this means we can obtain pointers to uobj's that have already been released and must protect against krefing them using kref_get_unless_zero. ================================================================== BUG: KASAN: use-after-free in copy_ah_attr_from_uverbs.isra.2+0x860/0xa00 Read of size 4 at addr ffff88005fda1ac8 by task syz-executor2/441 CPU: 1 PID: 441 Comm: syz-executor2 Not tainted 4.15.0-rc2+ #56 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org 04/01/2014 Call Trace: dump_stack+0x8d/0xd4 print_address_description+0x73/0x290 kasan_report+0x25c/0x370 ? copy_ah_attr_from_uverbs.isra.2+0x860/0xa00 copy_ah_attr_from_uverbs.isra.2+0x860/0xa00 ? uverbs_try_lock_object+0x68/0xc0 ? modify_qp.isra.7+0xdc4/0x10e0 modify_qp.isra.7+0xdc4/0x10e0 ib_uverbs_modify_qp+0xfe/0x170 ? ib_uverbs_query_qp+0x970/0x970 ? __lock_acquire+0xa11/0x1da0 ib_uverbs_write+0x55a/0xad0 ? ib_uverbs_query_qp+0x970/0x970 ? ib_uverbs_query_qp+0x970/0x970 ? ib_uverbs_open+0x760/0x760 ? futex_wake+0x147/0x410 ? sched_clock_cpu+0x18/0x180 ? check_prev_add+0x1680/0x1680 ? do_futex+0x3b6/0xa30 ? sched_clock_cpu+0x18/0x180 __vfs_write+0xf7/0x5c0 ? ib_uverbs_open+0x760/0x760 ? kernel_read+0x110/0x110 ? lock_acquire+0x370/0x370 ? __fget+0x264/0x3b0 vfs_write+0x18a/0x460 SyS_write+0xc7/0x1a0 ? SyS_read+0x1a0/0x1a0 ? trace_hardirqs_on_thunk+0x1a/0x1c entry_SYSCALL_64_fastpath+0x18/0x85 RIP: 0033:0x448e29 RSP: 002b:00007f443fee0c58 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f443fee16bc RCX: 0000000000448e29 RDX: 0000000000000078 RSI: 00000000209f8000 RDI: 0000000000000012 RBP: 000000000070bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000008e98 R14: 00000000006ebf38 R15: 0000000000000000 Allocated by task 1: kmem_cache_alloc_trace+0x16c/0x2f0 mlx5_alloc_cmd_msg+0x12e/0x670 cmd_exec+0x419/0x1810 mlx5_cmd_exec+0x40/0x70 mlx5_core_mad_ifc+0x187/0x220 mlx5_MAD_IFC+0xd7/0x1b0 mlx5_query_mad_ifc_gids+0x1f3/0x650 mlx5_ib_query_gid+0xa4/0xc0 ib_query_gid+0x152/0x1a0 ib_query_port+0x21e/0x290 mlx5_port_immutable+0x30f/0x490 ib_register_device+0x5dd/0x1130 mlx5_ib_add+0x3e7/0x700 mlx5_add_device+0x124/0x510 mlx5_register_interface+0x11f/0x1c0 mlx5_ib_init+0x56/0x61 do_one_initcall+0xa3/0x250 kernel_init_freeable+0x309/0x3b8 kernel_init+0x14/0x180 ret_from_fork+0x24/0x30 Freed by task 1: kfree+0xeb/0x2f0 mlx5_free_cmd_msg+0xcd/0x140 cmd_exec+0xeba/0x1810 mlx5_cmd_exec+0x40/0x70 mlx5_core_mad_ifc+0x187/0x220 mlx5_MAD_IFC+0xd7/0x1b0 mlx5_query_mad_ifc_gids+0x1f3/0x650 mlx5_ib_query_gid+0xa4/0xc0 ib_query_gid+0x152/0x1a0 ib_query_port+0x21e/0x290 mlx5_port_immutable+0x30f/0x490 ib_register_device+0x5dd/0x1130 mlx5_ib_add+0x3e7/0x700 mlx5_add_device+0x124/0x510 mlx5_register_interface+0x11f/0x1c0 mlx5_ib_init+0x56/0x61 do_one_initcall+0xa3/0x250 kernel_init_freeable+0x309/0x3b8 kernel_init+0x14/0x180 ret_from_fork+0x24/0x30 The buggy address belongs to the object at ffff88005fda1ab0 which belongs to the cache kmalloc-32 of size 32 The buggy address is located 24 bytes inside of 32-byte region [ffff88005fda1ab0, ffff88005fda1ad0) The buggy address belongs to the page: page:00000000d5655c19 count:1 mapcount:0 mapping: (null) index:0xffff88005fda1fc0 flags: 0x4000000000000100(slab) raw: 4000000000000100 0000000000000000 ffff88005fda1fc0 0000000180550008 raw: ffffea00017f6780 0000000400000004 ffff88006c803980 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88005fda1980: fc fc fb fb fb fb fc fc fb fb fb fb fc fc fb fb ffff88005fda1a00: fb fb fc fc fb fb fb fb fc fc 00 00 00 00 fc fc ffff88005fda1a80: fb fb fb fb fc fc fb fb fb fb fc fc fb fb fb fb ffff88005fda1b00: fc fc 00 00 00 00 fc fc fb fb fb fb fc fc fb fb ffff88005fda1b80: fb fb fc fc fb fb fb fb fc fc fb fb fb fb fc fc ==================================================================@ Cc: syzkaller <syzkaller@googlegroups.com> Cc: <stable@vger.kernel.org> # 4.11 Fixes: 3832125624b7 ("IB/core: Add support for idr types") Reported-by: Noa Osherovich <noaos@mellanox.com> Signed-off-by: Leon Romanovsky <leonro@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-02-15IB/uverbs: Hold the uobj write lock after allocateJason Gunthorpe1-1/+10
This clarifies the design intention that time between allocate and commit has the uobj exclusive to the caller. We already guarantee this by delaying publishing the uobj pointer via idr_insert, fd_install, list_add, etc. Additionally holding the usecnt lock during this period provides extra clarity and more protection against future mistakes. Fixes: 3832125624b7 ("IB/core: Add support for idr types") Signed-off-by: Leon Romanovsky <leon@kernel.org> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2017-08-31IB/core: Explicitly destroy an object while keeping uobjectMatan Barak1-0/+35
When some objects are destroyed, we need to extract their status at destruction. After object's destruction, this status (e.g. events_reported) relies in the uobject. In order to have the latest and correct status, the underlying object should be destroyed, but we should keep the uobject alive and read this information off the uobject. We introduce a rdma_explicit_destroy function. This function destroys the class type object (for example, the IDR class type which destroys the underlying object as well) and then convert the uobject to be of a null class type. This uobject will then be destroyed as any other uobject once uverbs_finalize_object[s] is called. Signed-off-by: Matan Barak <matanb@mellanox.com> Reviewed-by: Yishai Hadas <yishaih@mellanox.com> Signed-off-by: Doug Ledford <dledford@redhat.com>
2017-08-31IB/core: Add new ioctl interfaceMatan Barak1-0/+46
In this ioctl interface, processing the command starts from properties of the command and fetching the appropriate user objects before calling the handler. Parsing and validation is done according to a specifier declared by the driver's code. In the driver, all supported objects are declared. These objects are separated to different object namepsaces. Dividing objects to namespaces is done at initialization by using the higher bits of the object ids. This initialization can mix objects declared in different places to one parsing tree using in this ioctl interface. For each object we list all supported methods. Similarly to objects, methods are separated to method namespaces too. Namespacing is done similarly to the objects case. This could be used in order to add methods to an existing object. Each method has a specific handler, which could be either a default handler or a driver specific handler. Along with the handler, a bunch of attributes are specified as well. Similarly to objects and method, attributes are namespaced and hashed by their ids at initialization too. All supported attributes are subject to automatic fetching and validation. These attributes include the command, response and the method's related objects' ids. When these entities (objects, methods and attributes) are used, the high bits of the entities ids are used in order to calculate the hash bucket index. Then, these high bits are masked out in order to have a zero based index. Since we use these high bits for both bucketing and namespacing, we get a compact representation and O(1) array access. This is mandatory for efficient dispatching. Each attribute has a type (PTR_IN, PTR_OUT, IDR and FD) and a length. Attributes could be validated through some attributes, like: (*) Minimum size / Exact size (*) Fops for FD (*) Object type for IDR If an IDR/fd attribute is specified, the kernel also states the object type and the required access (NEW, WRITE, READ or DESTROY). All uobject/fd management is done automatically by the infrastructure, meaning - the infrastructure will fail concurrent commands that at least one of them requires concurrent access (WRITE/DESTROY), synchronize actions with device removals (dissociate context events) and take care of reference counting (increase/decrease) for concurrent actions invocation. The reference counts on the actual kernel objects shall be handled by the handlers. objects +--------+ | | | | methods +--------+ | | ns method method_spec +-----+ |len | +--------+ +------+[d]+-------+ +----------------+[d]+------------+ |attr1+-> |type | | object +> |method+-> | spec +-> + attr_buckets +-> |default_chain+--> +-----+ |idr_type| +--------+ +------+ |handler| | | +------------+ |attr2| |access | | | | | +-------+ +----------------+ |driver chain| +-----+ +--------+ | | | | +------------+ | | +------+ | | | | | | | | | | | | | | | | | | | | +--------+ [d] = Hash ids to groups using the high order bits The right types table is also chosen by using the high bits from the ids. Currently we have either default or driver specific groups. Once validation and object fetching (or creation) completed, we call the handler: int (*handler)(struct ib_device *ib_dev, struct ib_uverbs_file *ufile, struct uverbs_attr_bundle *ctx); ctx bundles attributes of different namespaces. Each element there is an array of attributes which corresponds to one namespaces of attributes. For example, in the usually used case: ctx core +----------------------------+ +------------+ | core: +---> | valid | +----------------------------+ | cmd_attr | | driver: | +------------+ |----------------------------+--+ | valid | | | cmd_attr | | +------------+ | | valid | | | obj_attr | | +------------+ | | drivers | +------------+ +> | valid | | cmd_attr | +------------+ | valid | | cmd_attr | +------------+ | valid | | obj_attr | +------------+ Signed-off-by: Matan Barak <matanb@mellanox.com> Reviewed-by: Yishai Hadas <yishaih@mellanox.com> Signed-off-by: Doug Ledford <dledford@redhat.com>
2017-08-30IB/core: Add support to finalize objects in one transactionMatan Barak1-0/+40
The new ioctl based infrastructure either commits or rollbacks all objects of the method as one transaction. In order to do that, we introduce a notion of dealing with a collection of objects that are related to a specific method. This also requires adding a notion of a method and attribute. A method contains a hash of attributes, where each bucket contains several attributes. The attributes are hashed according to their namespace which resides in the four upper bits of the id. For example, an object could be a CQ, which has an action of CREATE_CQ. This action has multiple attributes. For example, the CQ's new handle and the comp_channel. Each layer in this hierarchy - objects, methods and attributes is split into namespaces. The basic example for that is one namespace representing the default entities and another one representing the driver specific entities. When declaring these methods and attributes, we actually declare their specifications. When a method is executed, we actually allocates some space to hold auxiliary information. This auxiliary information contains meta-data about the required objects, such as pointers to their type information, pointers to the uobjects themselves (if exist), etc. The specification, along with the auxiliary information we allocated and filled is given to the finalize_objects function. Signed-off-by: Matan Barak <matanb@mellanox.com> Reviewed-by: Yishai Hadas <yishaih@mellanox.com> Signed-off-by: Doug Ledford <dledford@redhat.com>
2017-08-30IB/core: Add a generic way to execute an operation on a uobjectMatan Barak1-0/+58
The ioctl infrastructure treats all user-objects in the same manner. It gets objects ids from the user-space and by using the object type and type attributes mentioned in the object specification, it executes this required method. Passing an object id from the user-space as an attribute is carried out in three stages. The first is carried out before the actual handler and the last is carried out afterwards. The different supported operations are read, write, destroy and create. In the first stage, the former three actions just fetches the object from the repository (by using its id) and locks it. The last action allocates a new uobject. Afterwards, the second stage is carried out when the handler itself carries out the required modification of the object. The last stage is carried out after the handler finishes and commits the result. The former two operations just unlock the object. Destroy calls the "free object" operation, taking into account the object's type and releases the uobject as well. Creation just adds the new uobject to the repository, making the object visible to the application. In order to abstract these details from the ioctl infrastructure layer, we add uverbs_get_uobject_from_context and uverbs_finalize_object functions which corresponds to the first and last stages respectively. Signed-off-by: Matan Barak <matanb@mellanox.com> Reviewed-by: Yishai Hadas <yishaih@mellanox.com> Signed-off-by: Doug Ledford <dledford@redhat.com>
2017-04-20IB/core: Nullify ib_uobject during allocationMatan Barak1-1/+1
Currently, we initialize all fields of ib_uobject straight after allocation. Therefore, a kmalloc was sufficient. Since ib_uobject could be embedded in a type specific structure, we nullify it to spare programmer errors. Fixes: 3832125624b7 ('IB/core: Add support for idr types') Signed-off-by: Matan Barak <matanb@mellanox.com> Signed-off-by: Doug Ledford <dledford@redhat.com>
2017-04-20IB/core: Don't pass the lock state to _rdma_remove_commit_uobjectMatan Barak1-12/+12
The only scenario where this function was called while the lock is already taken is in the context cleanup scenario. Thus, in order not to pass the lock state to this function, we just call the remove logic straight from the cleanup context function. Fixes: 3832125624b7 ('IB/core: Add support for idr types') Signed-off-by: Matan Barak <matanb@mellanox.com> Reviewed-by: Sean Hefty <sean.hefty@intel.com> Signed-off-by: Doug Ledford <dledford@redhat.com>
2017-04-20IB/core: Rename write flag to exclusive in rdma_coreMatan Barak1-29/+31
We rename the "write" flags to "exclusive", as it's used for both WRITE and DESTROY actions. Fixes: 3832125624b7 ('IB/core: Add support for idr types') Signed-off-by: Matan Barak <matanb@mellanox.com> Reviewed-by: Sean Hefty <sean.hefty@intel.com> Signed-off-by: Doug Ledford <dledford@redhat.com>
2017-04-05IB/core: Add support for fd objectsMatan Barak1-1/+176
The completion channel we use in verbs infrastructure is FD based. Previously, we had a separate way to manage this object. Since we strive for a single way to manage any kind of object in this infrastructure, we conceptually treat all objects as subclasses of ib_uobject. This commit adds the necessary mechanism to support FD based objects like their IDR counterparts. FD objects release need to be synchronized with context release. We use the cleanup_mutex on the uverbs_file for that. Signed-off-by: Matan Barak <matanb@mellanox.com> Reviewed-by: Yishai Hadas <yishaih@mellanox.com> Signed-off-by: Doug Ledford <dledford@redhat.com>
2017-04-05IB/core: Add support for idr typesMatan Barak1-0/+450
The new ioctl infrastructure supports driver specific objects. Each such object type has a hot unplug function, allocation size and an order of destruction. When a ucontext is created, a new list is created in this ib_ucontext. This list contains all objects created under this ib_ucontext. When a ib_ucontext is destroyed, we traverse this list several time destroying the various objects by the order mentioned in the object type description. If few object types have the same destruction order, they are destroyed in an order opposite to their creation. Adding an object is done in two parts. First, an object is allocated and added to idr tree. Then, the command's handlers (in downstream patches) could work on this object and fill in its required details. After a successful command, the commit part is called and the user objects become ucontext visible. If the handler failed, alloc_abort should be called. Removing an uboject is done by calling lookup_get with the write flag and finalizing it with destroy_commit. A major change from the previous code is that we actually destroy the kernel object itself in destroy_commit (rather than just the uobject). We should make sure idr (per-uverbs-file) and list (per-ucontext) could be accessed concurrently without corrupting them. Signed-off-by: Matan Barak <matanb@mellanox.com> Reviewed-by: Yishai Hadas <yishaih@mellanox.com> Signed-off-by: Doug Ledford <dledford@redhat.com>