clk: at91: keep securam node alive while mapping it

[PATCH v1] clk: at91: keep securam node alive while mapping it

Posted by Yuho Choi 1 week, 3 days ago

pmc_register_ops() gets an owned reference to the
"atmel,sama5d2-securam" node with of_find_compatible_node().  The
success path dropped that reference before passing the node to
of_iomap(), leaving of_iomap() to consume a node pointer after the caller
had released its reference.

Move of_node_put() after of_iomap() so the node remains referenced for
the mapping operation.  The unavailable-node error path already releases
the reference.

Fixes: 4d21be864092 ("clk: at91: pmc: execute suspend/resume only for backup mode")
Signed-off-by: Yuho Choi <dbgh9129@gmail.com>
---
 drivers/clk/at91/pmc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/clk/at91/pmc.c b/drivers/clk/at91/pmc.c
index b618a5e00b00..03a6c31d6aa8 100644
--- a/drivers/clk/at91/pmc.c
+++ b/drivers/clk/at91/pmc.c
@@ -180,9 +180,9 @@ static int __init pmc_register_ops(void)
 		of_node_put(np);
 		return -ENODEV;
 	}
-	of_node_put(np);
 
 	at91_pmc_backup_suspend = of_iomap(np, 0);
+	of_node_put(np);
 	if (!at91_pmc_backup_suspend) {
 		pr_warn("%s(): unable to map securam\n", __func__);
 		return -ENOMEM;
-- 
2.43.0

Re: [PATCH v1] clk: at91: keep securam node alive while mapping it

Posted by Claudiu Beznea 6 days, 5 hours ago


On 5/29/26 07:20, Yuho Choi wrote:
> pmc_register_ops() gets an owned reference to the
> "atmel,sama5d2-securam" node with of_find_compatible_node().  The
> success path dropped that reference before passing the node to
> of_iomap(), leaving of_iomap() to consume a node pointer after the caller
> had released its reference.
> 
> Move of_node_put() after of_iomap() so the node remains referenced for
> the mapping operation.  The unavailable-node error path already releases
> the reference.
> 
> Fixes: 4d21be864092 ("clk: at91: pmc: execute suspend/resume only for backup mode")
> Signed-off-by: Yuho Choi<dbgh9129@gmail.com>

Missed to mention, applied to clk-microchip-fixes, thanks!

Re: [PATCH v1] clk: at91: keep securam node alive while mapping it

Posted by Brian Masney 6 days, 20 hours ago

On Fri, May 29, 2026 at 12:20:51AM -0400, Yuho Choi wrote:
> pmc_register_ops() gets an owned reference to the
> "atmel,sama5d2-securam" node with of_find_compatible_node().  The
> success path dropped that reference before passing the node to
> of_iomap(), leaving of_iomap() to consume a node pointer after the caller
> had released its reference.
> 
> Move of_node_put() after of_iomap() so the node remains referenced for
> the mapping operation.  The unavailable-node error path already releases
> the reference.
> 
> Fixes: 4d21be864092 ("clk: at91: pmc: execute suspend/resume only for backup mode")
> Signed-off-by: Yuho Choi <dbgh9129@gmail.com>

Reviewed-by: Brian Masney <bmasney@redhat.com>

Re: [PATCH v1] clk: at91: keep securam node alive while mapping it

Posted by Alexandre Belloni 1 week, 2 days ago

On 29/05/2026 00:20:51-0400, Yuho Choi wrote:
> pmc_register_ops() gets an owned reference to the
> "atmel,sama5d2-securam" node with of_find_compatible_node().  The
> success path dropped that reference before passing the node to
> of_iomap(), leaving of_iomap() to consume a node pointer after the caller
> had released its reference.
> 
> Move of_node_put() after of_iomap() so the node remains referenced for
> the mapping operation.  The unavailable-node error path already releases
> the reference.
> 
> Fixes: 4d21be864092 ("clk: at91: pmc: execute suspend/resume only for backup mode")
> Signed-off-by: Yuho Choi <dbgh9129@gmail.com>
Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

> ---
>  drivers/clk/at91/pmc.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/clk/at91/pmc.c b/drivers/clk/at91/pmc.c
> index b618a5e00b00..03a6c31d6aa8 100644
> --- a/drivers/clk/at91/pmc.c
> +++ b/drivers/clk/at91/pmc.c
> @@ -180,9 +180,9 @@ static int __init pmc_register_ops(void)
>  		of_node_put(np);
>  		return -ENODEV;
>  	}
> -	of_node_put(np);
>  
>  	at91_pmc_backup_suspend = of_iomap(np, 0);
> +	of_node_put(np);
>  	if (!at91_pmc_backup_suspend) {
>  		pr_warn("%s(): unable to map securam\n", __func__);
>  		return -ENOMEM;
> -- 
> 2.43.0
> 

-- 
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com