[PATCH AUTOSEL 4.19 67/68] net: thunderx: set tso_hdrs pointer to NULL in nicvf_free_snd_queue

Sasha Levin
2018-11-29T06:01:07Z

From: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>

[ Upstream commit ef2a7cf1d8831535b8991459567b385661eb4a36 ]

Reset snd_queue tso_hdrs pointer to NULL in nicvf_free_snd_queue routine
since it is used to check if tso dma descriptor queue has been previously
allocated. The issue can be triggered with the following reproducer:

$ip link set dev enP2p1s0v0 xdpdrv obj xdp_dummy.o
$ip link set dev enP2p1s0v0 xdpdrv off

[ 341.467649] WARNING: CPU: 74 PID: 2158 at mm/vmalloc.c:1511 __vunmap+0x98/0xe0
[ 341.515010] Hardware name: GIGABYTE H270-T70/MT70-HD0, BIOS T49 02/02/2018
[ 341.521874] pstate: 60400005 (nZCv daif +PAN -UAO)
[ 341.526654] pc : __vunmap+0x98/0xe0
[ 341.530132] lr : __vunmap+0x98/0xe0
[ 341.533609] sp : ffff00001c5db860
[ 341.536913] x29: ffff00001c5db860 x28: 0000000000020000
[ 341.542214] x27: ffff810feb5090b0 x26: ffff000017e57000
[ 341.547515] x25: 0000000000000000 x24: 00000000fbd00000
[ 341.552816] x23: 0000000000000000 x22: ffff810feb5090b0
[ 341.558117] x21: 0000000000000000 x20: 0000000000000000
[ 341.563418] x19: ffff000017e57000 x18: 0000000000000000
[ 341.568719] x17: 0000000000000000 x16: 0000000000000000
[ 341.574020] x15: 0000000000000010 x14: ffffffffffffffff
[ 341.579321] x13: ffff00008985eb27 x12: ffff00000985eb2f
[ 341.584622] x11: ffff0000096b3000 x10: ffff00001c5db510
[ 341.589923] x9 : 00000000ffffffd0 x8 : ffff0000086868e8
[ 341.595224] x7 : 3430303030303030 x6 : 00000000000006ef
[ 341.600525] x5 : 00000000003fffff x4 : 0000000000000000
[ 341.605825] x3 : 0000000000000000 x2 : ffffffffffffffff
[ 341.611126] x1 : ffff0000096b3728 x0 : 0000000000000038
[ 341.616428] Call trace:
[ 341.618866] __vunmap+0x98/0xe0
[ 341.621997] vunmap+0x3c/0x50
[ 341.624961] arch_dma_free+0x68/0xa0
[ 341.628534] dma_direct_free+0x50/0x80
[ 341.632285] nicvf_free_resources+0x160/0x2d8 [nicvf]
[ 341.637327] nicvf_config_data_transfer+0x174/0x5e8 [nicvf]
[ 341.642890] nicvf_stop+0x298/0x340 [nicvf]
[ 341.647066] __dev_close_many+0x9c/0x108
[ 341.650977] dev_close_many+0xa4/0x158
[ 341.654720] rollback_registered_many+0x140/0x530
[ 341.659414] rollback_registered+0x54/0x80
[ 341.663499] unregister_netdevice_queue+0x9c/0xe8
[ 341.668192] unregister_netdev+0x28/0x38
[ 341.672106] nicvf_remove+0xa4/0xa8 [nicvf]
[ 341.676280] nicvf_shutdown+0x20/0x30 [nicvf]
[ 341.680630] pci_device_shutdown+0x44/0x88
[ 341.684720] device_shutdown+0x144/0x250
[ 341.688640] kernel_restart_prepare+0x44/0x50
[ 341.692986] kernel_restart+0x20/0x68
[ 341.696638] __se_sys_reboot+0x210/0x238
[ 341.700550] __arm64_sys_reboot+0x24/0x30
[ 341.704555] el0_svc_handler+0x94/0x110
[ 341.708382] el0_svc+0x8/0xc
[ 341.711252] ---[ end trace 3f4019c8439959c9 ]---
[ 341.715874] page:ffff7e0003ef4000 count:0 mapcount:0 mapping:0000000000000000 index:0x4
[ 341.723872] flags: 0x1fffe000000000()
[ 341.727527] raw: 001fffe000000000 ffff7e0003f1a008 ffff7e0003ef4048 0000000000000000
[ 341.735263] raw: 0000000000000004 0000000000000000 00000000ffffffff 0000000000000000
[ 341.742994] page dumped because: VM_BUG_ON_PAGE(page_ref_count(page) == 0)

where xdp_dummy.c is a simple bpf program that forwards the incoming
frames to the network stack (available here:
https://github.com/altoor/xdp_walkthrough_examples/blob/master/sample_1/xdp_dummy.c)

Fixes: 05c773f52b96 ("net: thunderx: Add basic XDP support")
Fixes: 4863dea3fab0 ("net: Adding support for Cavium ThunderX network controller")
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/cavium/thunder/nicvf_queues.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/cavium/thunder/nicvf_queues.c b/drivers/net/ethernet/cavium/thunder/nicvf_queues.c
index 187a249ff2d1..fcaf18fa3904 100644
--- a/drivers/net/ethernet/cavium/thunder/nicvf_queues.c
+++ b/drivers/net/ethernet/cavium/thunder/nicvf_queues.c
@@ -585,10 +585,12 @@ static void nicvf_free_snd_queue(struct nicvf *nic, struct snd_queue *sq)
if (!sq->dmem.base)
return;

- if (sq->tso_hdrs)
+ if (sq->tso_hdrs) {
dma_free_coherent(&nic->pdev->dev,
sq->dmem.q_len * TSO_HEADER_SIZE,
sq->tso_hdrs, sq->tso_hdrs_phys);
+ sq->tso_hdrs = NULL;
+ }

/* Free pending skbs in the queue */
smp_rmb();
--
2.17.1