• Yonatan Cohen's avatar
    IB/rxe: Fix handling of erroneous WR · 3c87b4a8
    Yonatan Cohen authored
    commit 002e062e upstream.
    
    To correctly handle a erroneous WR this fix does the following
    1. Make sure the bad WQE causes a user completion event.
    2. Call rxe_completer to handle the erred WQE.
    
    Before the fix, when rxe_requester found a bad WQE, it changed its
    status to IB_WC_LOC_PROT_ERR and exit with 0 for non RC QPs.
    
    If this was the 1st WQE then there would be no ACK to invoke the
    completer and this bad WQE would be stuck in the QP's send-q.
    
    On top of that the requester exiting with 0 caused rxe_do_task to
    endlessly invoke rxe_requester, resulting in a soft-lockup attached
    below.
    
    In case the WQE was not the 1st and rxe_completer did get a chance to
    handle the bad WQE, it did not cause a complete event since the WQE's
    IB_SEND_SIGNALED flag was not set.
    
    Setting WQE status to IB_SEND_SIGNALED is subject to IBA spec
    version 1.2.1, section 10.7.3.1 Signaled Completions.
    
    NMI watchdog: BUG: soft lockup - CPU#7 stuck for 22s!
    [<ffffffffa0590145>] ? rxe_pool_get_index+0x35/0xb0 [rdma_rxe]
    [<ffffffffa05952ec>] lookup_mem+0x3c/0xc0 [rdma_rxe]
    [<ffffffffa0595534>] copy_data+0x1c4/0x230 [rdma_rxe]
    [<ffffffffa058c180>] rxe_requester+0x9d0/0x1100 [rdma_rxe]
    [<ffffffff8158e98a>] ? kfree_skbmem+0x5a/0x60
    [<ffffffffa05962c9>] rxe_do_task+0x89/0xf0 [rdma_rxe]
    [<ffffffffa05963e2>] rxe_run_task+0x12/0x30 [rdma_rxe]
    [<ffffffffa059110a>] rxe_post_send+0x41a/0x550 [rdma_rxe]
    [<ffffffff811ef922>] ? __kmalloc+0x182/0x200
    [<ffffffff816ba512>] ? down_read+0x12/0x40
    [<ffffffffa054bd32>] ib_uverbs_post_send+0x532/0x540 [ib_uverbs]
    [<ffffffff815f8722>] ? tcp_sendmsg+0x402/0xb80
    [<ffffffffa05453dc>] ib_uverbs_write+0x18c/0x3f0 [ib_uverbs]
    [<ffffffff81623c2e>] ? inet_recvmsg+0x7e/0xb0
    [<ffffffff8158764d>] ? sock_recvmsg+0x3d/0x50
    [<ffffffff81215b87>] __vfs_write+0x37/0x140
    [<ffffffff81216892>] vfs_write+0xb2/0x1b0
    [<ffffffff81217ce5>] SyS_write+0x55/0xc0
    [<ffffffff816bc672>] entry_SYSCALL_64_fastpath+0x1a/0xa
    
    Fixes: 8700e3e7 ("Soft RoCE driver")
    Signed-off-by: default avatarYonatan Cohen <yonatanc@mellanox.com>
    Reviewed-by: default avatarMoni Shoua <monis@mellanox.com>
    Signed-off-by: default avatarLeon Romanovsky <leon@kernel.org>
    Signed-off-by: default avatarDoug Ledford <dledford@redhat.com>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    3c87b4a8
rxe_req.c 19 KB