After calling irq_set_affinity_and_hint(), the cpumask pointer is
saved in desc->affinity_hint, and will be used later when reading
/proc/irq/<num>/affinity_hint. So the cpumask variable needs to be
persistent. Otherwise, we are accessing freed memory when reading
the affinity_hint file.
Also, need to clear affinity_hint before free_irq(), otherwise there
is a one-time warning and stack trace during module unloading:
[ 243.948687] WARNING: CPU: 10 PID: 1589 at kernel/irq/manage.c:1913 free_irq+0x318/0x360
...
[ 243.948753] Call Trace:
[ 243.948754] <TASK>
[ 243.948760] mana_gd_remove_irqs+0x78/0xc0 [mana]
[ 243.948767] mana_gd_remove+0x3e/0x80 [mana]
[ 243.948773] pci_device_remove+0x3d/0xb0
[ 243.948778] device_remove+0x46/0x70
[ 243.948782] device_release_driver_internal+0x1fe/0x280
[ 243.948785] driver_detach+0x4e/0xa0
[ 243.948787] bus_remove_driver+0x70/0xf0
[ 243.948789] driver_unregister+0x35/0x60
[ 243.948792] pci_unregister_driver+0x44/0x90
[ 243.948794] mana_driver_exit+0x14/0x3fe [mana]
[ 243.948800] __do_sys_delete_module.constprop.0+0x185/0x2f0
To fix the bug, use the persistent mask, cpumask_of(cpu#), and set
affinity_hint to NULL before freeing the IRQ, as required by free_irq().
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 71fa6887eeca ("net: mana: Assign interrupts to CPUs based on NUMA nodes")
Signed-off-by: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>
Reviewed-by: Michael Kelley <mikelley@xxxxxxxxxxxxx>
Reviewed-by: Leon Romanovsky <leonro@xxxxxxxxxx>
---
.../net/ethernet/microsoft/mana/gdma_main.c | 37 ++++++-------------
1 file changed, 11 insertions(+), 26 deletions(-)
diff --git a/drivers/net/ethernet/microsoft/mana/gdma_main.c b/drivers/net/ethernet/microsoft/mana/gdma_main.c
index b144f2237748..f9b8f372ec8a 100644
--- a/drivers/net/ethernet/microsoft/mana/gdma_main.c
+++ b/drivers/net/ethernet/microsoft/mana/gdma_main.c
@@ -1217,9 +1217,7 @@ static int mana_gd_setup_irqs(struct pci_dev *pdev)
unsigned int max_queues_per_port = num_online_cpus();
struct gdma_context *gc = pci_get_drvdata(pdev);
struct gdma_irq_context *gic;
- unsigned int max_irqs;
- u16 *cpus;
- cpumask_var_t req_mask;
+ unsigned int max_irqs, cpu;
int nvec, irq;
int err, i = 0, j;
@@ -1240,21 +1238,7 @@ static int mana_gd_setup_irqs(struct pci_dev *pdev)
goto free_irq_vector;
}
- if (!zalloc_cpumask_var(&req_mask, GFP_KERNEL)) {
- err = -ENOMEM;
- goto free_irq;
- }
-
- cpus = kcalloc(nvec, sizeof(*cpus), GFP_KERNEL);
- if (!cpus) {
- err = -ENOMEM;
- goto free_mask;
- }
- for (i = 0; i < nvec; i++)
- cpus[i] = cpumask_local_spread(i, gc->numa_node);
-
for (i = 0; i < nvec; i++) {
- cpumask_set_cpu(cpus[i], req_mask);
gic = &gc->irq_contexts[i];
gic->handler = NULL;
gic->arg = NULL;
@@ -1269,17 +1253,16 @@ static int mana_gd_setup_irqs(struct pci_dev *pdev)
irq = pci_irq_vector(pdev, i);
if (irq < 0) {
err = irq;
- goto free_mask;
+ goto free_irq;
}
err = request_irq(irq, mana_gd_intr, 0, gic->name, gic);
if (err)
- goto free_mask;
- irq_set_affinity_and_hint(irq, req_mask);
- cpumask_clear(req_mask);
+ goto free_irq;
+
+ cpu = cpumask_local_spread(i, gc->numa_node);
+ irq_set_affinity_and_hint(irq, cpumask_of(cpu));
}
- free_cpumask_var(req_mask);
- kfree(cpus);
err = mana_gd_alloc_res_map(nvec, &gc->msix_resource);
if (err)
@@ -1290,13 +1273,12 @@ static int mana_gd_setup_irqs(struct pci_dev *pdev)
return 0;
-free_mask:
- free_cpumask_var(req_mask);
- kfree(cpus);
free_irq:
for (j = i - 1; j >= 0; j--) {
irq = pci_irq_vector(pdev, j);
gic = &gc->irq_contexts[j];
+
+ irq_update_affinity_hint(irq, NULL);
free_irq(irq, gic);
}
@@ -1324,6 +1306,9 @@ static void mana_gd_remove_irqs(struct pci_dev *pdev)
continue;
gic = &gc->irq_contexts[i];
+
+ /* Need to clear the hint before free_irq */
+ irq_update_affinity_hint(irq, NULL);
free_irq(irq, gic);
}
--
2.25.1
