Revision 002e062e13db10973adb8302f231e48b477c7ccf authored by Yonatan Cohen on 16 November 2016, 08:39:15 UTC, committed by Doug Ledford on 17 November 2016, 01:03:44 UTC
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: 8700e3e7c485 ("Soft RoCE driver") Signed-off-by: Yonatan Cohen <yonatanc@mellanox.com> Reviewed-by: Moni Shoua <monis@mellanox.com> Signed-off-by: Leon Romanovsky <leon@kernel.org> Signed-off-by: Doug Ledford <dledford@redhat.com>
1 parent 1454ca3
llist.c
/*
* Lock-less NULL terminated single linked list
*
* The basic atomic operation of this list is cmpxchg on long. On
* architectures that don't have NMI-safe cmpxchg implementation, the
* list can NOT be used in NMI handlers. So code that uses the list in
* an NMI handler should depend on CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG.
*
* Copyright 2010,2011 Intel Corp.
* Author: Huang Ying <ying.huang@intel.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version
* 2 as published by the Free Software Foundation;
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/llist.h>
/**
* llist_add_batch - add several linked entries in batch
* @new_first: first entry in batch to be added
* @new_last: last entry in batch to be added
* @head: the head for your lock-less list
*
* Return whether list is empty before adding.
*/
bool llist_add_batch(struct llist_node *new_first, struct llist_node *new_last,
struct llist_head *head)
{
struct llist_node *first;
do {
new_last->next = first = ACCESS_ONCE(head->first);
} while (cmpxchg(&head->first, first, new_first) != first);
return !first;
}
EXPORT_SYMBOL_GPL(llist_add_batch);
/**
* llist_del_first - delete the first entry of lock-less list
* @head: the head for your lock-less list
*
* If list is empty, return NULL, otherwise, return the first entry
* deleted, this is the newest added one.
*
* Only one llist_del_first user can be used simultaneously with
* multiple llist_add users without lock. Because otherwise
* llist_del_first, llist_add, llist_add (or llist_del_all, llist_add,
* llist_add) sequence in another user may change @head->first->next,
* but keep @head->first. If multiple consumers are needed, please
* use llist_del_all or use lock between consumers.
*/
struct llist_node *llist_del_first(struct llist_head *head)
{
struct llist_node *entry, *old_entry, *next;
entry = smp_load_acquire(&head->first);
for (;;) {
if (entry == NULL)
return NULL;
old_entry = entry;
next = READ_ONCE(entry->next);
entry = cmpxchg(&head->first, old_entry, next);
if (entry == old_entry)
break;
}
return entry;
}
EXPORT_SYMBOL_GPL(llist_del_first);
/**
* llist_reverse_order - reverse order of a llist chain
* @head: first item of the list to be reversed
*
* Reverse the order of a chain of llist entries and return the
* new first entry.
*/
struct llist_node *llist_reverse_order(struct llist_node *head)
{
struct llist_node *new_head = NULL;
while (head) {
struct llist_node *tmp = head;
head = head->next;
tmp->next = new_head;
new_head = tmp;
}
return new_head;
}
EXPORT_SYMBOL_GPL(llist_reverse_order);
![swh spinner](/static/img/swh-spinner.gif)
Computing file changes ...