[PATCH 4.14 006/167] IB/core: Fix two kernel warnings triggered by rxe registration

Greg Kroah-Hartman
2018-02-21T12:46:57Z

From: Bart Van Assche <bart.vanassche@wdc.com>

commit 02ee9da347873699603d9ce0112a80b5dd69dea1 upstream.

Eliminate the WARN_ONs that create following two warnings when
registering an rxe device:

WARNING: CPU: 2 PID: 1005 at drivers/infiniband/core/device.c:449 ib_register_device+0x591/0x640 [ib_core]
CPU: 2 PID: 1005 Comm: run_tests Not tainted 4.15.0-rc4-dbg+ #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.0.0-prebuilt.qemu-project.org 04/01/2014
RIP: 0010:ib_register_device+0x591/0x640 [ib_core]
Call Trace:
rxe_register_device+0x3c6/0x470 [rdma_rxe]
rxe_add+0x543/0x5e0 [rdma_rxe]
rxe_net_add+0x37/0xb0 [rdma_rxe]
rxe_param_set_add+0x5a/0x120 [rdma_rxe]
param_attr_store+0x5e/0xc0
module_attr_store+0x19/0x30
sysfs_kf_write+0x3d/0x50
kernfs_fop_write+0x116/0x1a0
__vfs_write+0x23/0x120
vfs_write+0xbe/0x1b0
SyS_write+0x44/0xa0
entry_SYSCALL_64_fastpath+0x23/0x9a

WARNING: CPU: 2 PID: 1005 at drivers/infiniband/core/sysfs.c:1279 ib_device_register_sysfs+0x11d/0x160 [ib_core]
CPU: 2 PID: 1005 Comm: run_tests Tainted: G W 4.15.0-rc4-dbg+ #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.0.0-prebuilt.qemu-project.org 04/01/2014
RIP: 0010:ib_device_register_sysfs+0x11d/0x160 [ib_core]
Call Trace:
ib_register_device+0x3f7/0x640 [ib_core]
rxe_register_device+0x3c6/0x470 [rdma_rxe]
rxe_add+0x543/0x5e0 [rdma_rxe]
rxe_net_add+0x37/0xb0 [rdma_rxe]
rxe_param_set_add+0x5a/0x120 [rdma_rxe]
param_attr_store+0x5e/0xc0
module_attr_store+0x19/0x30
sysfs_kf_write+0x3d/0x50
kernfs_fop_write+0x116/0x1a0
__vfs_write+0x23/0x120
vfs_write+0xbe/0x1b0
SyS_write+0x44/0xa0
entry_SYSCALL_64_fastpath+0x23/0x9a

The code should accept either a parent pointer or a fully specified DMA
specification without producing warnings.

Fixes: 99db9494035f ("IB/core: Remove ib_device.dma_device")
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/infiniband/core/device.c | 20 ++++++++++++++------
drivers/infiniband/core/sysfs.c | 1 -
2 files changed, 14 insertions(+), 7 deletions(-)

--- a/drivers/infiniband/core/device.c
+++ b/drivers/infiniband/core/device.c
@@ -446,7 +446,6 @@ int ib_register_device(struct ib_device
struct ib_udata uhw = {.outlen = 0, .inlen = 0};
struct device *parent = device->dev.parent;

- WARN_ON_ONCE(!parent);
WARN_ON_ONCE(device->dma_device);
if (device->dev.dma_ops) {
/*
@@ -455,16 +454,25 @@ int ib_register_device(struct ib_device
* into device->dev.
*/
device->dma_device = &device->dev;
- if (!device->dev.dma_mask)
- device->dev.dma_mask = parent->dma_mask;
- if (!device->dev.coherent_dma_mask)
- device->dev.coherent_dma_mask =
- parent->coherent_dma_mask;
+ if (!device->dev.dma_mask) {
+ if (parent)
+ device->dev.dma_mask = parent->dma_mask;
+ else
+ WARN_ON_ONCE(true);
+ }
+ if (!device->dev.coherent_dma_mask) {
+ if (parent)
+ device->dev.coherent_dma_mask =
+ parent->coherent_dma_mask;
+ else
+ WARN_ON_ONCE(true);
+ }
} else {
/*
* The caller did not provide custom DMA operations. Use the
* DMA mapping operations of the parent device.
*/
+ WARN_ON_ONCE(!parent);
device->dma_device = parent;
}

--- a/drivers/infiniband/core/sysfs.c
+++ b/drivers/infiniband/core/sysfs.c
@@ -1262,7 +1262,6 @@ int ib_device_register_sysfs(struct ib_d
int ret;
int i;

- WARN_ON_ONCE(!device->dev.parent);
ret = dev_set_name(class_dev, "%s", device->name);
if (ret)
return ret;