[PATCH 5.8 088/124] net/mlx5: Fix request_irqs error flow

From: Greg Kroah-Hartman
Date: Mon Oct 12 2020 - 09:48:50 EST


From: Maor Gottlieb <maorg@xxxxxxxxxx>

[ Upstream commit 732ebfab7fe96b7ac9a3df3208f14752a4bb6db3 ]

Fix error flow handling in request_irqs which try to free irq
that we failed to request.
It fixes the below trace.

WARNING: CPU: 1 PID: 7587 at kernel/irq/manage.c:1684 free_irq+0x4d/0x60
CPU: 1 PID: 7587 Comm: bash Tainted: G W OE 4.15.15-1.el7MELLANOXsmp-x86_64 #1
Hardware name: Advantech SKY-6200/SKY-6200, BIOS F2.00 08/06/2020
RIP: 0010:free_irq+0x4d/0x60
RSP: 0018:ffffc9000ef47af0 EFLAGS: 00010282
RAX: ffff88001476ae00 RBX: 0000000000000655 RCX: 0000000000000000
RDX: ffff88001476ae00 RSI: ffffc9000ef47ab8 RDI: ffff8800398bb478
RBP: ffff88001476a838 R08: ffff88001476ae00 R09: 000000000000156d
R10: 0000000000000000 R11: 0000000000000004 R12: ffff88001476a838
R13: 0000000000000006 R14: ffff88001476a888 R15: 00000000ffffffe4
FS: 00007efeadd32740(0000) GS:ffff88047fc40000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc9cc010008 CR3: 00000001a2380004 CR4: 00000000007606e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
mlx5_irq_table_create+0x38d/0x400 [mlx5_core]
? atomic_notifier_chain_register+0x50/0x60
mlx5_load_one+0x7ee/0x1130 [mlx5_core]
init_one+0x4c9/0x650 [mlx5_core]
pci_device_probe+0xb8/0x120
driver_probe_device+0x2a1/0x470
? driver_allows_async_probing+0x30/0x30
bus_for_each_drv+0x54/0x80
__device_attach+0xa3/0x100
pci_bus_add_device+0x4a/0x90
pci_iov_add_virtfn+0x2dc/0x2f0
pci_enable_sriov+0x32e/0x420
mlx5_core_sriov_configure+0x61/0x1b0 [mlx5_core]
? kstrtoll+0x22/0x70
num_vf_store+0x4b/0x70 [mlx5_core]
kernfs_fop_write+0x102/0x180
__vfs_write+0x26/0x140
? rcu_all_qs+0x5/0x80
? _cond_resched+0x15/0x30
? __sb_start_write+0x41/0x80
vfs_write+0xad/0x1a0
SyS_write+0x42/0x90
do_syscall_64+0x60/0x110
entry_SYSCALL_64_after_hwframe+0x3d/0xa2

Fixes: 24163189da48 ("net/mlx5: Separate IRQ request/free from EQ life cycle")
Signed-off-by: Maor Gottlieb <maorg@xxxxxxxxxx>
Reviewed-by: Eran Ben Elisha <eranbe@xxxxxxxxxx>
Signed-off-by: Saeed Mahameed <saeedm@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c b/drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c
index 373981a659c7c..6fd9749203944 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c
@@ -115,7 +115,7 @@ static int request_irqs(struct mlx5_core_dev *dev, int nvec)
return 0;

err_request_irq:
- for (; i >= 0; i--) {
+ while (i--) {
struct mlx5_irq *irq = mlx5_irq_get(dev, i);
int irqn = pci_irq_vector(dev->pdev, i);

--
2.25.1