linux/include/rdma, branch v5.7

RDMA/core: Fix double destruction of uobject

2020-05-27T17:22:57Z

Fix use after free when user user space request uobject concurrently for the same object, within the RCU grace period. In that case, remove_handle_idr_uobject() is called twice and we will have an extra put on the uobject which cause use after free. Fix it by leaving the uobject write locked after it was removed from the idr. Call to rdma_lookup_put_uobject with UVERBS_LOOKUP_DESTROY instead of UVERBS_LOOKUP_WRITE will do the work. refcount_t: underflow; use-after-free. WARNING: CPU: 0 PID: 1381 at lib/refcount.c:28 refcount_warn_saturate+0xfe/0x1a0 Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 1381 Comm: syz-executor.0 Not tainted 5.5.0-rc3 #8 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014 Call Trace: dump_stack+0x94/0xce panic+0x234/0x56f __warn+0x1cc/0x1e1 report_bug+0x200/0x310 fixup_bug.part.11+0x32/0x80 do_error_trap+0xd3/0x100 do_invalid_op+0x31/0x40 invalid_op+0x1e/0x30 RIP: 0010:refcount_warn_saturate+0xfe/0x1a0 Code: 0f 0b eb 9b e8 23 f6 6d ff 80 3d 6c d4 19 03 00 75 8d e8 15 f6 6d ff 48 c7 c7 c0 02 55 bd c6 05 57 d4 19 03 01 e8 a2 58 49 ff <0f> 0b e9 6e ff ff ff e8 f6 f5 6d ff 80 3d 42 d4 19 03 00 0f 85 5c RSP: 0018:ffffc90002df7b98 EFLAGS: 00010282 RAX: 0000000000000000 RBX: ffff88810f6a193c RCX: ffffffffba649009 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff88811b0283cc RBP: 0000000000000003 R08: ffffed10236060e3 R09: ffffed10236060e3 R10: 0000000000000001 R11: ffffed10236060e2 R12: ffff88810f6a193c R13: ffffc90002df7d60 R14: 0000000000000000 R15: ffff888116ae6a08 uverbs_uobject_put+0xfd/0x140 __uobj_perform_destroy+0x3d/0x60 ib_uverbs_close_xrcd+0x148/0x170 ib_uverbs_write+0xaa5/0xdf0 __vfs_write+0x7c/0x100 vfs_write+0x168/0x4a0 ksys_write+0xc8/0x200 do_syscall_64+0x9c/0x390 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x465b49 Code: f7 d8 64 89 02 b8 ff ff ff ff c3 66 0f 1f 44 00 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f759d122c58 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000000000073bfa8 RCX: 0000000000465b49 RDX: 000000000000000c RSI: 0000000020000080 RDI: 0000000000000003 RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f759d1236bc R13: 00000000004ca27c R14: 000000000070de40 R15: 00000000ffffffff Dumping ftrace buffer: (ftrace buffer empty) Kernel Offset: 0x39400000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) Fixes: 7452a3c745a2 ("IB/uverbs: Allow RDMA_REMOVE_DESTROY to work concurrently with disassociate") Link: https://lore.kernel.org/r/20200527135534.482279-1-leon@kernel.org Signed-off-by: Maor Gottlieb Signed-off-by: Leon Romanovsky Signed-off-by: Jason Gunthorpe

IB/mlx5: Expose UAR object and its alloc/destroy commands

2020-03-27T15:59:04Z

Expose UAR object and its alloc/destroy commands to be used over the ioctl interface by user space applications. This API supports both BF & NC modes and enables a dynamic allocation of UARs once really needed. As the number of driver objects were limited by the core ones when the merged tree is prepared, had to decrease the number of core objects to enable the new UAR object usage. Link: https://lore.kernel.org/r/20200324060143.1569116-2-leon@kernel.org Signed-off-by: Yishai Hadas Reviewed-by: Michael Guralnik Signed-off-by: Leon Romanovsky Signed-off-by: Jason Gunthorpe

RDMA/cm: Delete not implemented CM peer to peer communication

2020-03-13T13:46:53Z

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 Reviewed-by: Mark Zhang Signed-off-by: Jason Gunthorpe

RDMA: Replace zero-length array with flexible-array member

2020-02-20T17:33:51Z

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 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Link: https://lore.kernel.org/r/20200213010425.GA13068@embeddedor.com Signed-off-by: Gustavo A. R. Silva Signed-off-by: Jason Gunthorpe # added a few more

RDMA/core: Add helper function to retrieve driver gid context from gid attr

2020-02-19T20:54:25Z

Adding a helper function to retrieve the driver gid context from the gid attr. Link: https://lore.kernel.org/r/1582107594-5180-2-git-send-email-selvin.xavier@broadcom.com Suggested-by: Jason Gunthorpe Signed-off-by: Selvin Xavier Signed-off-by: Jason Gunthorpe

RDMA/core: Get rid of ib_create_qp_user

2020-02-19T00:27:37Z

This function accepts a udata but does nothing with it, and is never passed a !NULL udata. Rename it to ib_create_qp which was the only caller and remove the udata. Link: https://lore.kernel.org/r/20200213191911.GA9898@ziepe.ca Reviewed-by: Max Gurtovoy Signed-off-by: Jason Gunthorpe

RDMA/core: Make the entire API tree static

2020-01-30T20:28:52Z

Compilation of mlx5 driver without CONFIG_INFINIBAND_USER_ACCESS generates the following error. on x86_64: ld: drivers/infiniband/hw/mlx5/main.o: in function `mlx5_ib_handler_MLX5_IB_METHOD_VAR_OBJ_ALLOC': main.c:(.text+0x186d): undefined reference to `ib_uverbs_get_ucontext_file' ld: drivers/infiniband/hw/mlx5/main.o:(.rodata+0x2480): undefined reference to `uverbs_idr_class' ld: drivers/infiniband/hw/mlx5/main.o:(.rodata+0x24d8): undefined reference to `uverbs_destroy_def_handler' This is happening because some parts of the UAPI description are not static. This is a hold over from earlier code that relied on struct pointers to refer to object types, now object types are referenced by number. Remove the unused globals and add statics to the remaining UAPI description elements. Remove the redundent #ifdefs around mlx5_ib_*defs and obsolete mlx5_ib_get_devx_tree(). The compiler now trims alot more unused code, including the above problematic definitions when !CONFIG_INFINIBAND_USER_ACCESS. Fixes: 7be76bef320b ("IB/mlx5: Introduce VAR object and its alloc/destroy methods") Reported-by: Randy Dunlap Acked-by: Randy Dunlap Signed-off-by: Jason Gunthorpe

RDMA/cm: Remove CM message structs

2020-01-25T19:11:37Z

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 Reviewed-by: Leon Romanovsky Signed-off-by: Jason Gunthorpe

RDMA/cm: Add SET/GET implementations to hide IBA wire format

2020-01-25T19:05:59Z

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 Tested-by: Leon Romanovsky Reviewed-by: Leon Romanovsky Signed-off-by: Jason Gunthorpe

Merge tag 'rds-odp-for-5.5' into rdma.git for-next

2020-01-21T13:55:04Z

From https://git.kernel.org/pub/scm/linux/kernel/git/leon/linux-rdma Leon Romanovsky says: ==================== Use ODP MRs for kernel ULPs The following series extends MR creation routines to allow creation of user MRs through kernel ULPs as a proxy. The immediate use case is to allow RDS to work over FS-DAX, which requires ODP (on-demand-paging) MRs to be created and such MRs were not possible to create prior this series. The first part of this patchset extends RDMA to have special verb ib_reg_user_mr(). The common use case that uses this function is a userspace application that allocates memory for HCA access but the responsibility to register the memory at the HCA is on an kernel ULP. This ULP acts as an agent for the userspace application. The second part provides advise MR functionality for ULPs. This is integral part of ODP flows and used to trigger pagefaults in advance to prepare memory before running working set. The third part is actual user of those in-kernel APIs. ==================== * tag 'rds-odp-for-5.5': net/rds: Use prefetch for On-Demand-Paging MR net/rds: Handle ODP mr registration/unregistration net/rds: Detect need of On-Demand-Paging memory registration RDMA/mlx5: Fix handling of IOVA != user_va in ODP paths IB/mlx5: Mask out unsupported ODP capabilities for kernel QPs RDMA/mlx5: Don't fake udata for kernel path IB/mlx5: Add ODP WQE handlers for kernel QPs IB/core: Add interface to advise_mr for kernel users IB/core: Introduce ib_reg_user_mr IB: Allow calls to ib_umem_get from kernel ULPs Signed-off-by: Jason Gunthorpe