From: Maor Gottlieb <maorg@xxxxxxxxxxxx>
According to the locking scheme, mlx5_ib_update_xlt should be called
with srcu_read_lock().
This fixes the below LOCKDEP trace.
[ 861.917222] WARNING: CPU: 1 PID: 1130 at
drivers/infiniband/hw/mlx5/odp.c:132 mlx5_odp_populate_xlt+0x175/0x180
[mlx5_ib]
[ 861.921080] Modules linked in: xt_conntrack xt_MASQUERADE
nf_conntrack_netlink nfnetlink xt_addrtype iptable_nat nf_nat
nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 br_netfilter overlay ib_srp
scsi_transport_srp rpcrdma rdma_ucm ib_iser libiscsi
scsi_transport_iscsi rdma_cm iw_cm ib_umad ib_ipoib ib_cm mlx5_ib
ib_uverbs ib_core mlx5_core mlxfw ptp pps_core
[ 861.930133] CPU: 1 PID: 1130 Comm: kworker/u16:11 Tainted: G W
5.8.0-rc5_for_upstream_debug_2020_07_13_11_04 #1
[ 861.932034] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS
rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014
[ 861.933801] Workqueue: events_unbound mlx5_ib_prefetch_mr_work
[mlx5_ib]
[ 861.934933] RIP: 0010:mlx5_odp_populate_xlt+0x175/0x180 [mlx5_ib]
[ 861.935954] Code: 08 e2 85 c0 0f 84 65 ff ff ff 49 8b 87 60 01 00 00
be ff ff ff ff 48 8d b8 b0 39 00 00 e8 93 e0 50 e1 85 c0 0f 85 45 ff ff
ff <0f> 0b e9 3e ff ff ff 0f 0b eb c7 0f 1f 44 00 00 48 8b 87 98 0f 00
[ 861.938855] RSP: 0018:ffff88840f44fc68 EFLAGS: 00010246
[ 861.939707] RAX: 0000000000000000 RBX: ffff88840cc9d000 RCX:
ffff88840efcd940
[ 861.940788] RDX: 0000000000000000 RSI: ffff88844871b9b0 RDI:
ffff88840efce100
[ 861.941880] RBP: ffff88840cc9d040 R08: 0000000000000040 R09:
0000000000000001
[ 861.943020] R10: ffff88846ced3068 R11: 0000000000000000 R12:
00000000000156ec
[ 861.944133] R13: 0000000000000004 R14: 0000000000000004 R15:
ffff888439941000
[ 861.945228] FS: 0000000000000000(0000) GS:ffff88846fa80000(0000)
knlGS:0000000000000000
[ 861.946557] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 861.947512] CR2: 00007f8536d12430 CR3: 0000000437a5e006 CR4:
0000000000360ea0
[ 861.948609] DR0: 0000000000000000 DR1: 0000000000000000 DR2:
0000000000000000
[ 861.949684] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7:
0000000000000400
[ 861.950804] Call Trace:
[ 861.951300] mlx5_ib_update_xlt+0x37c/0x7c0 [mlx5_ib]
[ 861.952145] pagefault_mr+0x315/0x440 [mlx5_ib]
[ 861.952895] mlx5_ib_prefetch_mr_work+0x56/0xa0 [mlx5_ib]
[ 861.953763] process_one_work+0x215/0x5c0
[ 861.954477] worker_thread+0x3c/0x380
[ 861.955127] ? process_one_work+0x5c0/0x5c0
[ 861.955851] kthread+0x133/0x150
[ 861.956426] ? kthread_park+0x90/0x90
[ 861.957061] ret_from_fork+0x1f/0x30
[ 861.957686] irq event stamp: 199569
[ 861.958318] hardirqs last enabled at (199577): [<ffffffff8119bf39>]
console_unlock+0x439/0x590
[ 861.959720] hardirqs last disabled at (199584): [<ffffffff8119bb81>]
console_unlock+0x81/0x590
[ 861.961080] softirqs last enabled at (199600): [<ffffffff81e00293>]
__do_softirq+0x293/0x47e
[ 861.971725] softirqs last disabled at (199613): [<ffffffff81c00f0f>]
asm_call_on_stack+0xf/0x20
[ 861.973142] ---[ end trace e6f026aa6012c21e ]---
Fixes: 5256edcb98a1 ("RDMA/mlx5: Rework implicit ODP destroy")
Signed-off-by: Maor Gottlieb <maorg@xxxxxxxxxxxx>
Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxxxx>
---
It is not really need to go to -rc, not urgent.
---
drivers/infiniband/core/uverbs_std_types_mr.c | 2 +-
drivers/infiniband/core/verbs.c | 3 +++
drivers/infiniband/hw/mlx5/odp.c | 9 +++++++++
3 files changed, 13 insertions(+), 1 deletion(-)
diff --git a/drivers/infiniband/core/uverbs_std_types_mr.c b/drivers/infiniband/core/uverbs_std_types_mr.c
index 62f58ad56afd..9b22bb553e8b 100644
--- a/drivers/infiniband/core/uverbs_std_types_mr.c
+++ b/drivers/infiniband/core/uverbs_std_types_mr.c
@@ -69,7 +69,7 @@ static int UVERBS_HANDLER(UVERBS_METHOD_ADVISE_MR)(
num_sge = uverbs_attr_ptr_get_array_size(
attrs, UVERBS_ATTR_ADVISE_MR_SGE_LIST, sizeof(struct ib_sge));
- if (num_sge < 0)
+ if (num_sge <= 0)
return num_sge;
sg_list = uverbs_attr_get_alloced_ptr(attrs,
diff --git a/drivers/infiniband/core/verbs.c b/drivers/infiniband/core/verbs.c
index 73f3ea8af714..674949233d21 100644
--- a/drivers/infiniband/core/verbs.c
+++ b/drivers/infiniband/core/verbs.c
@@ -2073,6 +2073,9 @@ int ib_advise_mr(struct ib_pd *pd, enum ib_uverbs_advise_mr_advice advice,
if (!pd->device->ops.advise_mr)
return -EOPNOTSUPP;
+ if (!num_sge)
+ return 0;
+
return pd->device->ops.advise_mr(pd, advice, flags, sg_list, num_sge,
NULL);
}
diff --git a/drivers/infiniband/hw/mlx5/odp.c b/drivers/infiniband/hw/mlx5/odp.c
index aa6f08ad0d03..4f1e46733830 100644
--- a/drivers/infiniband/hw/mlx5/odp.c
+++ b/drivers/infiniband/hw/mlx5/odp.c
@@ -816,6 +816,7 @@ static int pagefault_mr(struct mlx5_ib_mr *mr, u64 io_virt, size_t bcnt,
{
struct ib_umem_odp *odp = to_ib_umem_odp(mr->umem);
+ lockdep_assert_held(&mr->dev->odp_srcu);
if (unlikely(io_virt < mr->mmkey.iova))
return -EFAULT;
@@ -1765,10 +1766,17 @@ static void mlx5_ib_prefetch_mr_work(struct work_struct *w)
{
struct prefetch_mr_work *work =
container_of(w, struct prefetch_mr_work, work);
+ struct mlx5_ib_dev *dev;
u32 bytes_mapped = 0;
+ int srcu_key;
int ret;
u32 i;
+ /* We rely on IB/core that work is executed if we have num_sge != 0 only. */
+ WARN_ON(!work->num_sge);
+ dev = work->frags[0].mr->dev;
+ /* SRCU should be held when calling to mlx5_odp_populate_xlt() */
+ srcu_key = srcu_read_lock(&dev->odp_srcu);
for (i = 0; i < work->num_sge; ++i) {
ret = pagefault_mr(work->frags[i].mr, work->frags[i].io_virt,
work->frags[i].length, &bytes_mapped,
@@ -1777,6 +1785,7 @@ static void mlx5_ib_prefetch_mr_work(struct work_struct *w)
continue;
mlx5_update_odp_stats(work->frags[i].mr, prefetch, ret);
}
+ srcu_read_unlock(&dev->odp_srcu, srcu_key);
destroy_prefetch_work(work);
}
--
2.26.2
