2022-09-14 02:17:25

by Qingfang Deng

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

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.

Fixes: 8deec94c6040 ("net: stmmac: set IRQ affinity hint for multi MSI vectors")
Signed-off-by: Qingfang DENG <[email protected]>
---
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;
--
2.34.1

2022-09-14 10:54:10

by Robin Murphy

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

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 <[email protected]>
> ---
> 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;