diff options
author | Michael J. Ruhl <michael.j.ruhl@intel.com> | 2019-02-26 08:45:25 -0800 |
---|---|---|
committer | Jason Gunthorpe <jgg@mellanox.com> | 2019-03-04 15:47:23 -0400 |
commit | d757c60eca9b22f4d108929a24401e0fdecda0b1 (patch) | |
tree | e7b890d54e90e573ef6f3c0a27d621e57056d943 | |
parent | 38bbc9f0381550d1d227fc57afa08436e36b32fc (diff) |
IB/rdmavt: Fix concurrency panics in QP post_send and modify to error
The RC/UC code path can go through a software loopback. In this code path
the receive side QP is manipulated.
If two threads are working on the QP receive side (i.e. post_send, and
modify_qp to an error state), QP information can be corrupted.
(post_send via loopback)
set r_sge
loop
update r_sge
(modify_qp)
take r_lock
update r_sge <---- r_sge is now incorrect
(post_send)
update r_sge <---- crash, etc.
...
This can lead to one of the two following crashes:
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: hfi1_copy_sge+0xf1/0x2e0 [hfi1]
PGD 8000001fe6a57067 PUD 1fd9e0c067 PMD 0
Call Trace:
ruc_loopback+0x49b/0xbc0 [hfi1]
hfi1_do_send+0x38e/0x3e0 [hfi1]
_hfi1_do_send+0x1e/0x20 [hfi1]
process_one_work+0x17f/0x440
worker_thread+0x126/0x3c0
kthread+0xd1/0xe0
ret_from_fork_nospec_begin+0x21/0x21
or:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000048
IP: rvt_clear_mr_refs+0x45/0x370 [rdmavt]
PGD 80000006ae5eb067 PUD ef15d0067 PMD 0
Call Trace:
rvt_error_qp+0xaa/0x240 [rdmavt]
rvt_modify_qp+0x47f/0xaa0 [rdmavt]
ib_security_modify_qp+0x8f/0x400 [ib_core]
ib_modify_qp_with_udata+0x44/0x70 [ib_core]
modify_qp.isra.23+0x1eb/0x2b0 [ib_uverbs]
ib_uverbs_modify_qp+0xaa/0xf0 [ib_uverbs]
ib_uverbs_write+0x272/0x430 [ib_uverbs]
vfs_write+0xc0/0x1f0
SyS_write+0x7f/0xf0
system_call_fastpath+0x1c/0x21
Fix by using the appropriate locking on the receiving QP.
Fixes: 15703461533a ("IB/{hfi1, qib, rdmavt}: Move ruc_loopback to rdmavt")
Cc: <stable@vger.kernel.org> #v4.9+
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
-rw-r--r-- | drivers/infiniband/sw/rdmavt/qp.c | 33 |
1 files changed, 23 insertions, 10 deletions
diff --git a/drivers/infiniband/sw/rdmavt/qp.c b/drivers/infiniband/sw/rdmavt/qp.c index 337365806261..a34b9a2a32b6 100644 --- a/drivers/infiniband/sw/rdmavt/qp.c +++ b/drivers/infiniband/sw/rdmavt/qp.c @@ -2790,6 +2790,18 @@ again: } EXPORT_SYMBOL(rvt_copy_sge); +static enum ib_wc_status loopback_qp_drop(struct rvt_ibport *rvp, + struct rvt_qp *sqp) +{ + rvp->n_pkt_drops++; + /* + * For RC, the requester would timeout and retry so + * shortcut the timeouts and just signal too many retries. + */ + return sqp->ibqp.qp_type == IB_QPT_RC ? + IB_WC_RETRY_EXC_ERR : IB_WC_SUCCESS; +} + /** * ruc_loopback - handle UC and RC loopback requests * @sqp: the sending QP @@ -2862,17 +2874,14 @@ again: } spin_unlock_irqrestore(&sqp->s_lock, flags); - if (!qp || !(ib_rvt_state_ops[qp->state] & RVT_PROCESS_RECV_OK) || + if (!qp) { + send_status = loopback_qp_drop(rvp, sqp); + goto serr_no_r_lock; + } + spin_lock_irqsave(&qp->r_lock, flags); + if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_RECV_OK) || qp->ibqp.qp_type != sqp->ibqp.qp_type) { - rvp->n_pkt_drops++; - /* - * For RC, the requester would timeout and retry so - * shortcut the timeouts and just signal too many retries. - */ - if (sqp->ibqp.qp_type == IB_QPT_RC) - send_status = IB_WC_RETRY_EXC_ERR; - else - send_status = IB_WC_SUCCESS; + send_status = loopback_qp_drop(rvp, sqp); goto serr; } @@ -3030,6 +3039,7 @@ do_write: wqe->wr.send_flags & IB_SEND_SOLICITED); send_comp: + spin_unlock_irqrestore(&qp->r_lock, flags); spin_lock_irqsave(&sqp->s_lock, flags); rvp->n_loop_pkts++; flush_send: @@ -3056,6 +3066,7 @@ rnr_nak: } if (sqp->s_rnr_retry_cnt < 7) sqp->s_rnr_retry--; + spin_unlock_irqrestore(&qp->r_lock, flags); spin_lock_irqsave(&sqp->s_lock, flags); if (!(ib_rvt_state_ops[sqp->state] & RVT_PROCESS_RECV_OK)) goto clr_busy; @@ -3084,6 +3095,8 @@ err: rvt_rc_error(qp, wc.status); serr: + spin_unlock_irqrestore(&qp->r_lock, flags); +serr_no_r_lock: spin_lock_irqsave(&sqp->s_lock, flags); rvt_send_complete(sqp, wqe, send_status); if (sqp->ibqp.qp_type == IB_QPT_RC) { |