Re: [PATCH net] net: stmmac: fix invalid usage of irq_set_affinity_hint

From: Robin Murphy
Date: Wed Sep 14 2022 - 06:48:03 EST


On 2022-09-14 02:51, Qingfang DENG wrote:
The cpumask should not be a local variable, since its pointer is saved
to irq_desc and may be accessed from procfs.
To fix it, store cpumask to the heap.

FWIW, by the look of it you might be able to use cpumask_of() and not store anything at all.

Robin.

Fixes: 8deec94c6040 ("net: stmmac: set IRQ affinity hint for multi MSI vectors")
Signed-off-by: Qingfang DENG <dqfext@xxxxxxxxx>
---
drivers/net/ethernet/stmicro/stmmac/stmmac.h | 2 ++
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 15 ++++++++-------
2 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac.h b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
index bdbf86cb102a..720e9f2a40d8 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
@@ -77,6 +77,7 @@ struct stmmac_tx_queue {
dma_addr_t dma_tx_phy;
dma_addr_t tx_tail_addr;
u32 mss;
+ cpumask_t cpu_mask;
};
struct stmmac_rx_buffer {
@@ -114,6 +115,7 @@ struct stmmac_rx_queue {
unsigned int len;
unsigned int error;
} state;
+ cpumask_t cpu_mask;
};
struct stmmac_channel {
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 8418e795cc21..7b1c1be998e3 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -3469,7 +3469,6 @@ static int stmmac_request_irq_multi_msi(struct net_device *dev)
{
struct stmmac_priv *priv = netdev_priv(dev);
enum request_irq_err irq_err;
- cpumask_t cpu_mask;
int irq_idx = 0;
char *int_name;
int ret;
@@ -3580,9 +3579,10 @@ static int stmmac_request_irq_multi_msi(struct net_device *dev)
irq_idx = i;
goto irq_error;
}
- cpumask_clear(&cpu_mask);
- cpumask_set_cpu(i % num_online_cpus(), &cpu_mask);
- irq_set_affinity_hint(priv->rx_irq[i], &cpu_mask);
+ cpumask_set_cpu(i % num_online_cpus(),
+ &priv->dma_conf.rx_queue[i].cpu_mask);
+ irq_set_affinity_hint(priv->rx_irq[i],
+ &priv->dma_conf.rx_queue[i].cpu_mask);
}
/* Request Tx MSI irq */
@@ -3605,9 +3605,10 @@ static int stmmac_request_irq_multi_msi(struct net_device *dev)
irq_idx = i;
goto irq_error;
}
- cpumask_clear(&cpu_mask);
- cpumask_set_cpu(i % num_online_cpus(), &cpu_mask);
- irq_set_affinity_hint(priv->tx_irq[i], &cpu_mask);
+ cpumask_set_cpu(i % num_online_cpus(),
+ &priv->dma_conf.tx_queue[i].cpu_mask);
+ irq_set_affinity_hint(priv->tx_irq[i],
+ &priv->dma_conf.tx_queue[i].cpu_mask);
}
return 0;