After applied Stefan Wahren patch ("ARM: cpuidle: Avoid memleak if init
fail") there have no memleak issue, but the code is not consistent to
handle initialization failure between driver registration and device
registration. And when device registration fails, it misses to
unregister the driver.
So this patch is to refine failure handling in init flow, it adds two
'goto' tags: when register device fails, it goto 'init_dev_fail' tag and
free 'dev' structure and unregister driver; when register driver fails,
it goto 'init_drv_fail' tag and free 'drv' structure.
Cc: Daniel Lezcano <[email protected]>
Cc: Stefan Wahren <[email protected]>
Signed-off-by: Leo Yan <[email protected]>
---
drivers/cpuidle/cpuidle-arm.c | 25 ++++++++++++++++---------
1 file changed, 16 insertions(+), 9 deletions(-)
diff --git a/drivers/cpuidle/cpuidle-arm.c b/drivers/cpuidle/cpuidle-arm.c
index 52a7505..f419f6a 100644
--- a/drivers/cpuidle/cpuidle-arm.c
+++ b/drivers/cpuidle/cpuidle-arm.c
@@ -86,10 +86,13 @@ static int __init arm_idle_init(void)
for_each_possible_cpu(cpu) {
+ drv = NULL;
+ dev = NULL;
+
drv = kmemdup(&arm_idle_driver, sizeof(*drv), GFP_KERNEL);
if (!drv) {
ret = -ENOMEM;
- goto out_fail;
+ goto init_drv_fail;
}
drv->cpumask = (struct cpumask *)cpumask_of(cpu);
@@ -104,13 +107,13 @@ static int __init arm_idle_init(void)
ret = dt_init_idle_driver(drv, arm_idle_state_match, 1);
if (ret <= 0) {
ret = ret ? : -ENODEV;
- goto init_fail;
+ goto init_drv_fail;
}
ret = cpuidle_register_driver(drv);
if (ret) {
pr_err("Failed to register cpuidle driver\n");
- goto init_fail;
+ goto init_drv_fail;
}
/*
@@ -128,14 +131,14 @@ static int __init arm_idle_init(void)
if (ret) {
pr_err("CPU %d failed to init idle CPU ops\n", cpu);
- goto out_fail;
+ goto init_dev_fail;
}
dev = kzalloc(sizeof(*dev), GFP_KERNEL);
if (!dev) {
pr_err("Failed to allocate cpuidle device\n");
ret = -ENOMEM;
- goto out_fail;
+ goto init_dev_fail;
}
dev->cpu = cpu;
@@ -143,15 +146,19 @@ static int __init arm_idle_init(void)
if (ret) {
pr_err("Failed to register cpuidle device for CPU %d\n",
cpu);
- kfree(dev);
- goto out_fail;
+ goto init_dev_fail;
}
}
return 0;
-init_fail:
+
+init_dev_fail:
+ kfree(dev);
+ cpuidle_unregister_driver(drv);
+
+init_drv_fail:
kfree(drv);
-out_fail:
+
while (--cpu >= 0) {
dev = per_cpu(cpuidle_devices, cpu);
cpuidle_unregister_device(dev);
--
2.7.4
commit d50a7d8acd78 ("ARM: cpuidle: Support asymmetric idle definition")
supports multiple CPU idle driver so every CPU has its own driver. When
the initialization fails, the failure handling releases the resources
for every previous CPU; so it needs to retrieve every CPU device and
driver handler and unregister them. But the function
cpuidle_get_driver() can only return current CPU driver handler but not
the iterated CPU driver handler, so it cannot release resource properly.
This patch is to replace cpuidle_get_driver() with
cpuidle_get_cpu_driver(), every CPU has its own device handler so this
function can get back correct driver handler for the CPU according to
the CPU device handler. By using this CPU driver handler we can release
resource properly.
Cc: Daniel Lezcano <[email protected]>
Cc: Stefan Wahren <[email protected]>
Signed-off-by: Leo Yan <[email protected]>
Fixes: d50a7d8acd78 ("ARM: cpuidle: Support asymmetric idle definition")
---
drivers/cpuidle/cpuidle-arm.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/cpuidle/cpuidle-arm.c b/drivers/cpuidle/cpuidle-arm.c
index f419f6a..ef34780 100644
--- a/drivers/cpuidle/cpuidle-arm.c
+++ b/drivers/cpuidle/cpuidle-arm.c
@@ -161,9 +161,9 @@ static int __init arm_idle_init(void)
while (--cpu >= 0) {
dev = per_cpu(cpuidle_devices, cpu);
+ drv = cpuidle_get_cpu_driver(dev);
cpuidle_unregister_device(dev);
kfree(dev);
- drv = cpuidle_get_driver();
cpuidle_unregister_driver(drv);
kfree(drv);
}
--
2.7.4
Hi Stefan, Daniel,
On Mon, Sep 04, 2017 at 02:52:13PM +0800, Leo Yan wrote:
> After applied Stefan Wahren patch ("ARM: cpuidle: Avoid memleak if init
> fail") there have no memleak issue, but the code is not consistent to
> handle initialization failure between driver registration and device
> registration. And when device registration fails, it misses to
> unregister the driver.
>
> So this patch is to refine failure handling in init flow, it adds two
> 'goto' tags: when register device fails, it goto 'init_dev_fail' tag and
> free 'dev' structure and unregister driver; when register driver fails,
> it goto 'init_drv_fail' tag and free 'drv' structure.
>
> Cc: Daniel Lezcano <[email protected]>
> Cc: Stefan Wahren <[email protected]>
> Signed-off-by: Leo Yan <[email protected]>
Just want to reminding, this patch is based on Stefan's patch:
https://patchwork.kernel.org/patch/9932833/
First thing is Stefan patch is not merged so I just want to note here
have some dependency with Stefan patch. BTW, if you think we should
merge this patch with Stefan patch, it's fine for me to merge into
Stefan patch.
Thanks for suggetion.
> ---
> drivers/cpuidle/cpuidle-arm.c | 25 ++++++++++++++++---------
> 1 file changed, 16 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/cpuidle/cpuidle-arm.c b/drivers/cpuidle/cpuidle-arm.c
> index 52a7505..f419f6a 100644
> --- a/drivers/cpuidle/cpuidle-arm.c
> +++ b/drivers/cpuidle/cpuidle-arm.c
> @@ -86,10 +86,13 @@ static int __init arm_idle_init(void)
>
> for_each_possible_cpu(cpu) {
>
> + drv = NULL;
> + dev = NULL;
> +
> drv = kmemdup(&arm_idle_driver, sizeof(*drv), GFP_KERNEL);
> if (!drv) {
> ret = -ENOMEM;
> - goto out_fail;
> + goto init_drv_fail;
> }
>
> drv->cpumask = (struct cpumask *)cpumask_of(cpu);
> @@ -104,13 +107,13 @@ static int __init arm_idle_init(void)
> ret = dt_init_idle_driver(drv, arm_idle_state_match, 1);
> if (ret <= 0) {
> ret = ret ? : -ENODEV;
> - goto init_fail;
> + goto init_drv_fail;
> }
>
> ret = cpuidle_register_driver(drv);
> if (ret) {
> pr_err("Failed to register cpuidle driver\n");
> - goto init_fail;
> + goto init_drv_fail;
> }
>
> /*
> @@ -128,14 +131,14 @@ static int __init arm_idle_init(void)
>
> if (ret) {
> pr_err("CPU %d failed to init idle CPU ops\n", cpu);
> - goto out_fail;
> + goto init_dev_fail;
> }
>
> dev = kzalloc(sizeof(*dev), GFP_KERNEL);
> if (!dev) {
> pr_err("Failed to allocate cpuidle device\n");
> ret = -ENOMEM;
> - goto out_fail;
> + goto init_dev_fail;
> }
> dev->cpu = cpu;
>
> @@ -143,15 +146,19 @@ static int __init arm_idle_init(void)
> if (ret) {
> pr_err("Failed to register cpuidle device for CPU %d\n",
> cpu);
> - kfree(dev);
> - goto out_fail;
> + goto init_dev_fail;
> }
> }
>
> return 0;
> -init_fail:
> +
> +init_dev_fail:
> + kfree(dev);
> + cpuidle_unregister_driver(drv);
> +
> +init_drv_fail:
> kfree(drv);
> -out_fail:
> +
> while (--cpu >= 0) {
> dev = per_cpu(cpuidle_devices, cpu);
> cpuidle_unregister_device(dev);
> --
> 2.7.4
>