9554de394b
vm_ops is now initialized in ib_uverbs_mmap() with the recent rdma mmap API changes. Earlier it was done in rdma_umap_priv_init() which would not be called unless a driver called rdma_user_mmap_io() in its mmap. i40iw does not use the rdma_user_mmap_io API but sets the vma's vm_private_data to a driver object. This now conflicts with the vm_op rdma_umap_close as priv pointer points to the i40iw driver object instead of the private data setup by core when rdma_user_mmap_io is called. This leads to a crash in rdma_umap_close with a mmap put being called when it should not have. Remove the redundant setting of the vma private_data in i40iw as it is not used. Also move i40iw over to use the rdma_user_mmap_io API. This gives the extra protection of having the mappings zapped when the context is detsroyed. BUG: unable to handle page fault for address: 0000000100000001 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 0 P4D 0 Oops: 0002 [#1] SMP PTI CPU: 6 PID: 9528 Comm: rping Kdump: loaded Not tainted 5.5.0-rc4+ #117 Hardware name: Gigabyte Technology Co., Ltd. To be filled by O.E.M./Q87M-D2H, BIOS F7 01/17/2014 RIP: 0010:rdma_user_mmap_entry_put+0xa/0x30 [ib_core] RSP: 0018:ffffb340c04c7c38 EFLAGS: 00010202 RAX: 00000000ffffffff RBX: ffff9308e7be2a00 RCX: 000000000000cec0 RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000100000001 RBP: ffff9308dc7641f0 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: ffffffff8d4414d8 R12: ffff93075182c780 R13: 0000000000000001 R14: ffff93075182d2a8 R15: ffff9308e2ddc840 FS: 0000000000000000(0000) GS:ffff9308fdc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000100000001 CR3: 00000002e0412004 CR4: 00000000001606e0 Call Trace: rdma_umap_close+0x40/0x90 [ib_uverbs] remove_vma+0x43/0x80 exit_mmap+0xfd/0x1b0 mmput+0x6e/0x130 do_exit+0x290/0xcc0 ? get_signal+0x152/0xc40 do_group_exit+0x46/0xc0 get_signal+0x1bd/0xc40 ? prepare_to_wait_event+0x97/0x190 do_signal+0x36/0x630 ? remove_wait_queue+0x60/0x60 ? __audit_syscall_exit+0x1d9/0x290 ? rcu_read_lock_sched_held+0x52/0x90 ? kfree+0x21c/0x2e0 exit_to_usermode_loop+0x4f/0xc3 do_syscall_64+0x1ed/0x270 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7fae715a81fd Code: Bad RIP value. RSP: 002b:00007fae6e163cb0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: fffffffffffffe00 RBX: 00007fae6e163d30 RCX: 00007fae715a81fd RDX: 0000000000000010 RSI: 00007fae6e163cf0 RDI: 0000000000000003 RBP: 00000000013413a0 R08: 00007fae68000000 R09: 0000000000000017 R10: 0000000000000001 R11: 0000000000000293 R12: 00007fae680008c0 R13: 00007fae6e163cf0 R14: 00007fae717c9804 R15: 00007fae6e163ed0 CR2: 0000000100000001 ---[ end trace b33d58d3a06782cb ]--- RIP: 0010:rdma_user_mmap_entry_put+0xa/0x30 [ib_core] Fixes: b86deba977a9 ("RDMA/core: Move core content from ib_uverbs to ib_core") Link: https://lore.kernel.org/r/20200107162223.1745-1-shiraz.saleem@intel.com Signed-off-by: Shiraz Saleem <shiraz.saleem@intel.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.