After discussion with especially Wolfram and Jingoo it was decided to convert the code to use the Managed Device Resource.
I lack this kind of hardware so preferably should someone do a HW test.
Rickard Strandqvist (1):
i2c: busses: i2c-pxa.c: Fix for possible null pointer dereferenc
drivers/i2c/busses/i2c-pxa.c | 37 ++++++++++++++++---------------------
1 file changed, 16 insertions(+), 21 deletions(-)
--
1.7.10.4
Fix for possible null pointer dereferenc, and there is a risk for memory leak if something unexpected happens and the function returns.
It now use Managed Device Resource instead.
Signed-off-by: Rickard Strandqvist <[email protected]>
---
drivers/i2c/busses/i2c-pxa.c | 37 ++++++++++++++++---------------------
1 file changed, 16 insertions(+), 21 deletions(-)
diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
index be671f7..2edb633 100644
--- a/drivers/i2c/busses/i2c-pxa.c
+++ b/drivers/i2c/busses/i2c-pxa.c
@@ -1141,10 +1141,10 @@ static int i2c_pxa_probe(struct platform_device *dev)
struct resource *res = NULL;
int ret, irq;
- i2c = kzalloc(sizeof(struct pxa_i2c), GFP_KERNEL);
+ i2c = devm_kzalloc(&dev->dev, sizeof(struct pxa_i2c), GFP_KERNEL);
if (!i2c) {
ret = -ENOMEM;
- goto emalloc;
+ goto err_nothing_to_release;
}
/* Default adapter num to device id; i2c_pxa_probe_dt can override. */
@@ -1154,18 +1154,19 @@ static int i2c_pxa_probe(struct platform_device *dev)
if (ret > 0)
ret = i2c_pxa_probe_pdata(dev, i2c, &i2c_type);
if (ret < 0)
- goto eclk;
+ goto err_nothing_to_release;
res = platform_get_resource(dev, IORESOURCE_MEM, 0);
irq = platform_get_irq(dev, 0);
if (res == NULL || irq < 0) {
ret = -ENODEV;
- goto eclk;
+ goto err_nothing_to_release;
}
- if (!request_mem_region(res->start, resource_size(res), res->name)) {
+ if (!devm_request_mem_region(&dev->dev, res->start,
+ resource_size(res), res->name)) {
ret = -ENOMEM;
- goto eclk;
+ goto emalloc;
}
i2c->adap.owner = THIS_MODULE;
@@ -1176,16 +1177,16 @@ static int i2c_pxa_probe(struct platform_device *dev)
strlcpy(i2c->adap.name, "pxa_i2c-i2c", sizeof(i2c->adap.name));
- i2c->clk = clk_get(&dev->dev, NULL);
+ i2c->clk = devm_clk_get(&dev->dev, NULL);
if (IS_ERR(i2c->clk)) {
ret = PTR_ERR(i2c->clk);
- goto eclk;
+ goto emalloc;
}
- i2c->reg_base = ioremap(res->start, resource_size(res));
- if (!i2c->reg_base) {
+ i2c->reg_base = devm_ioremap_resource(&adev->dev, res));
+ if (IS_ERR(i2c->reg_base)) {
ret = -EIO;
- goto eremap;
+ goto emalloc;
}
i2c->reg_ibmr = i2c->reg_base + pxa_reg_layout[i2c_type].ibmr;
@@ -1227,10 +1228,10 @@ static int i2c_pxa_probe(struct platform_device *dev)
i2c->adap.algo = &i2c_pxa_pio_algorithm;
} else {
i2c->adap.algo = &i2c_pxa_algorithm;
- ret = request_irq(irq, i2c_pxa_handler, IRQF_SHARED,
- dev_name(&dev->dev), i2c);
+ ret = devm_request_irq(&dev->dev, irq, i2c_pxa_handler,
+ IRQF_SHARED, dev_name(&dev->dev), i2c);
if (ret)
- goto ereqirq;
+ goto emalloc;
}
i2c_pxa_reset(i2c);
@@ -1261,15 +1262,9 @@ static int i2c_pxa_probe(struct platform_device *dev)
eadapt:
if (!i2c->use_pio)
free_irq(irq, i2c);
-ereqirq:
- clk_disable_unprepare(i2c->clk);
- iounmap(i2c->reg_base);
-eremap:
- clk_put(i2c->clk);
-eclk:
- kfree(i2c);
emalloc:
release_mem_region(res->start, resource_size(res));
+err_nothing_to_release:
return ret;
}
--
1.7.10.4
On Friday, July 04, 2014 5:19 AM, Rickard Strandqvist wrote:
>
> Fix for possible null pointer dereferenc, and there is a risk
> for memory leak if something unexpected
s/dereferenc/dereference
The columns of this commit is too long.
Please keep about 80 columns.
> happens and the function returns.
> It now use Managed Device Resource instead.
s/use/uses
>
> Signed-off-by: Rickard Strandqvist <[email protected]>
> ---
> drivers/i2c/busses/i2c-pxa.c | 37 ++++++++++++++++---------------------
> 1 file changed, 16 insertions(+), 21 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
> index be671f7..2edb633 100644
> --- a/drivers/i2c/busses/i2c-pxa.c
> +++ b/drivers/i2c/busses/i2c-pxa.c
> @@ -1141,10 +1141,10 @@ static int i2c_pxa_probe(struct platform_device *dev)
> struct resource *res = NULL;
> int ret, irq;
>
> - i2c = kzalloc(sizeof(struct pxa_i2c), GFP_KERNEL);
> + i2c = devm_kzalloc(&dev->dev, sizeof(struct pxa_i2c), GFP_KERNEL);
> if (!i2c) {
> ret = -ENOMEM;
> - goto emalloc;
> + goto err_nothing_to_release;
> }
>
> /* Default adapter num to device id; i2c_pxa_probe_dt can override. */
> @@ -1154,18 +1154,19 @@ static int i2c_pxa_probe(struct platform_device *dev)
> if (ret > 0)
> ret = i2c_pxa_probe_pdata(dev, i2c, &i2c_type);
> if (ret < 0)
> - goto eclk;
> + goto err_nothing_to_release;
>
> res = platform_get_resource(dev, IORESOURCE_MEM, 0);
> irq = platform_get_irq(dev, 0);
> if (res == NULL || irq < 0) {
> ret = -ENODEV;
> - goto eclk;
> + goto err_nothing_to_release;
> }
>
> - if (!request_mem_region(res->start, resource_size(res), res->name)) {
> + if (!devm_request_mem_region(&dev->dev, res->start,
> + resource_size(res), res->name)) {
> ret = -ENOMEM;
> - goto eclk;
> + goto emalloc;
> }
>
> i2c->adap.owner = THIS_MODULE;
> @@ -1176,16 +1177,16 @@ static int i2c_pxa_probe(struct platform_device *dev)
>
> strlcpy(i2c->adap.name, "pxa_i2c-i2c", sizeof(i2c->adap.name));
>
> - i2c->clk = clk_get(&dev->dev, NULL);
> + i2c->clk = devm_clk_get(&dev->dev, NULL);
> if (IS_ERR(i2c->clk)) {
> ret = PTR_ERR(i2c->clk);
> - goto eclk;
> + goto emalloc;
> }
>
> - i2c->reg_base = ioremap(res->start, resource_size(res));
> - if (!i2c->reg_base) {
> + i2c->reg_base = devm_ioremap_resource(&adev->dev, res));
> + if (IS_ERR(i2c->reg_base)) {
> ret = -EIO;
> - goto eremap;
> + goto emalloc;
> }
>
> i2c->reg_ibmr = i2c->reg_base + pxa_reg_layout[i2c_type].ibmr;
> @@ -1227,10 +1228,10 @@ static int i2c_pxa_probe(struct platform_device *dev)
> i2c->adap.algo = &i2c_pxa_pio_algorithm;
> } else {
> i2c->adap.algo = &i2c_pxa_algorithm;
> - ret = request_irq(irq, i2c_pxa_handler, IRQF_SHARED,
> - dev_name(&dev->dev), i2c);
> + ret = devm_request_irq(&dev->dev, irq, i2c_pxa_handler,
> + IRQF_SHARED, dev_name(&dev->dev), i2c);
> if (ret)
> - goto ereqirq;
> + goto emalloc;
> }
>
> i2c_pxa_reset(i2c);
> @@ -1261,15 +1262,9 @@ static int i2c_pxa_probe(struct platform_device *dev)
> eadapt:
> if (!i2c->use_pio)
> free_irq(irq, i2c);
> -ereqirq:
> - clk_disable_unprepare(i2c->clk);
> - iounmap(i2c->reg_base);
> -eremap:
> - clk_put(i2c->clk);
> -eclk:
> - kfree(i2c);
> emalloc:
> release_mem_region(res->start, resource_size(res));
This function can be removed, because devm_request_mem_region()
is used. So, please remove release_mem_region().
Best regards,
Jingoo Han
> +err_nothing_to_release:
> return ret;
> }
>
> --
> 1.7.10.4
Hello Rickard,
Since this is a probe function there is also no need to release the devm_*
resources in the i2c_pxa_remove function, this leads to double free.
Also I have a few nit-pick comments below.
On Thu, Jul 03, 2014 at 10:19:16PM +0200, Rickard Strandqvist wrote:
> Fix for possible null pointer dereferenc, and there is a risk for memory leak if something unexpected happens and the function returns.
> It now use Managed Device Resource instead.
>
> Signed-off-by: Rickard Strandqvist <[email protected]>
> ---
> drivers/i2c/busses/i2c-pxa.c | 37 ++++++++++++++++---------------------
> 1 file changed, 16 insertions(+), 21 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
> index be671f7..2edb633 100644
> --- a/drivers/i2c/busses/i2c-pxa.c
> +++ b/drivers/i2c/busses/i2c-pxa.c
> @@ -1141,10 +1141,10 @@ static int i2c_pxa_probe(struct platform_device *dev)
> struct resource *res = NULL;
> int ret, irq;
>
> - i2c = kzalloc(sizeof(struct pxa_i2c), GFP_KERNEL);
> + i2c = devm_kzalloc(&dev->dev, sizeof(struct pxa_i2c), GFP_KERNEL);
> if (!i2c) {
> ret = -ENOMEM;
> - goto emalloc;
> + goto err_nothing_to_release;
Perhaps its a good idea to return directly here, then the label
err_nothing_to_release can be removed.
> }
>
> /* Default adapter num to device id; i2c_pxa_probe_dt can override. */
> @@ -1154,18 +1154,19 @@ static int i2c_pxa_probe(struct platform_device *dev)
> if (ret > 0)
> ret = i2c_pxa_probe_pdata(dev, i2c, &i2c_type);
> if (ret < 0)
> - goto eclk;
> + goto err_nothing_to_release;
Same here.
>
> res = platform_get_resource(dev, IORESOURCE_MEM, 0);
> irq = platform_get_irq(dev, 0);
> if (res == NULL || irq < 0) {
> ret = -ENODEV;
> - goto eclk;
> + goto err_nothing_to_release;
Same here.
> }
>
> - if (!request_mem_region(res->start, resource_size(res), res->name)) {
> + if (!devm_request_mem_region(&dev->dev, res->start,
> + resource_size(res), res->name)) {
> ret = -ENOMEM;
> - goto eclk;
> + goto emalloc;
We could also return directly here since the release_mem_region call should
be removed, as mentioned in Jingoos reply.
> }
>
> i2c->adap.owner = THIS_MODULE;
> @@ -1176,16 +1177,16 @@ static int i2c_pxa_probe(struct platform_device *dev)
>
> strlcpy(i2c->adap.name, "pxa_i2c-i2c", sizeof(i2c->adap.name));
>
> - i2c->clk = clk_get(&dev->dev, NULL);
> + i2c->clk = devm_clk_get(&dev->dev, NULL);
> if (IS_ERR(i2c->clk)) {
> ret = PTR_ERR(i2c->clk);
> - goto eclk;
> + goto emalloc;
Same here.
> }
>
> - i2c->reg_base = ioremap(res->start, resource_size(res));
> - if (!i2c->reg_base) {
> + i2c->reg_base = devm_ioremap_resource(&adev->dev, res));
> + if (IS_ERR(i2c->reg_base)) {
> ret = -EIO;
> - goto eremap;
> + goto emalloc;
Same here.
> }
>
> i2c->reg_ibmr = i2c->reg_base + pxa_reg_layout[i2c_type].ibmr;
> @@ -1227,10 +1228,10 @@ static int i2c_pxa_probe(struct platform_device *dev)
> i2c->adap.algo = &i2c_pxa_pio_algorithm;
> } else {
> i2c->adap.algo = &i2c_pxa_algorithm;
> - ret = request_irq(irq, i2c_pxa_handler, IRQF_SHARED,
> - dev_name(&dev->dev), i2c);
> + ret = devm_request_irq(&dev->dev, irq, i2c_pxa_handler,
> + IRQF_SHARED, dev_name(&dev->dev), i2c);
> if (ret)
> - goto ereqirq;
> + goto emalloc;
Same here.
> }
>
> i2c_pxa_reset(i2c);
> @@ -1261,15 +1262,9 @@ static int i2c_pxa_probe(struct platform_device *dev)
> eadapt:
> if (!i2c->use_pio)
> free_irq(irq, i2c);
The free_irq() call should also be removed since devm_request_irq() was used.
> -ereqirq:
> - clk_disable_unprepare(i2c->clk);
> - iounmap(i2c->reg_base);
> -eremap:
> - clk_put(i2c->clk);
> -eclk:
> - kfree(i2c);
> emalloc:
> release_mem_region(res->start, resource_size(res));
> +err_nothing_to_release:
> return ret;
> }
>
Best regards,
Emil Goode
2014-07-04 11:10 GMT+02:00 Emil Goode <[email protected]>:
> Hello Rickard,
>
> Since this is a probe function there is also no need to release the devm_*
> resources in the i2c_pxa_remove function, this leads to double free.
>
> Also I have a few nit-pick comments below.
>
> On Thu, Jul 03, 2014 at 10:19:16PM +0200, Rickard Strandqvist wrote:
>> Fix for possible null pointer dereferenc, and there is a risk for memory leak if something unexpected happens and the function returns.
>> It now use Managed Device Resource instead.
>>
>> Signed-off-by: Rickard Strandqvist <[email protected]>
>> ---
>> drivers/i2c/busses/i2c-pxa.c | 37 ++++++++++++++++---------------------
>> 1 file changed, 16 insertions(+), 21 deletions(-)
>>
>> diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
>> index be671f7..2edb633 100644
>> --- a/drivers/i2c/busses/i2c-pxa.c
>> +++ b/drivers/i2c/busses/i2c-pxa.c
>> @@ -1141,10 +1141,10 @@ static int i2c_pxa_probe(struct platform_device *dev)
>> struct resource *res = NULL;
>> int ret, irq;
>>
>> - i2c = kzalloc(sizeof(struct pxa_i2c), GFP_KERNEL);
>> + i2c = devm_kzalloc(&dev->dev, sizeof(struct pxa_i2c), GFP_KERNEL);
>> if (!i2c) {
>> ret = -ENOMEM;
>> - goto emalloc;
>> + goto err_nothing_to_release;
>
> Perhaps its a good idea to return directly here, then the label
> err_nothing_to_release can be removed.
>
>> }
>>
>> /* Default adapter num to device id; i2c_pxa_probe_dt can override. */
>> @@ -1154,18 +1154,19 @@ static int i2c_pxa_probe(struct platform_device *dev)
>> if (ret > 0)
>> ret = i2c_pxa_probe_pdata(dev, i2c, &i2c_type);
>> if (ret < 0)
>> - goto eclk;
>> + goto err_nothing_to_release;
>
> Same here.
>
>>
>> res = platform_get_resource(dev, IORESOURCE_MEM, 0);
>> irq = platform_get_irq(dev, 0);
>> if (res == NULL || irq < 0) {
>> ret = -ENODEV;
>> - goto eclk;
>> + goto err_nothing_to_release;
>
> Same here.
>
>> }
>>
>> - if (!request_mem_region(res->start, resource_size(res), res->name)) {
>> + if (!devm_request_mem_region(&dev->dev, res->start,
>> + resource_size(res), res->name)) {
>> ret = -ENOMEM;
>> - goto eclk;
>> + goto emalloc;
>
> We could also return directly here since the release_mem_region call should
> be removed, as mentioned in Jingoos reply.
>
>> }
>>
>> i2c->adap.owner = THIS_MODULE;
>> @@ -1176,16 +1177,16 @@ static int i2c_pxa_probe(struct platform_device *dev)
>>
>> strlcpy(i2c->adap.name, "pxa_i2c-i2c", sizeof(i2c->adap.name));
>>
>> - i2c->clk = clk_get(&dev->dev, NULL);
>> + i2c->clk = devm_clk_get(&dev->dev, NULL);
>> if (IS_ERR(i2c->clk)) {
>> ret = PTR_ERR(i2c->clk);
>> - goto eclk;
>> + goto emalloc;
>
> Same here.
>
>> }
>>
>> - i2c->reg_base = ioremap(res->start, resource_size(res));
>> - if (!i2c->reg_base) {
>> + i2c->reg_base = devm_ioremap_resource(&adev->dev, res));
>> + if (IS_ERR(i2c->reg_base)) {
>> ret = -EIO;
>> - goto eremap;
>> + goto emalloc;
>
> Same here.
>
>> }
>>
>> i2c->reg_ibmr = i2c->reg_base + pxa_reg_layout[i2c_type].ibmr;
>> @@ -1227,10 +1228,10 @@ static int i2c_pxa_probe(struct platform_device *dev)
>> i2c->adap.algo = &i2c_pxa_pio_algorithm;
>> } else {
>> i2c->adap.algo = &i2c_pxa_algorithm;
>> - ret = request_irq(irq, i2c_pxa_handler, IRQF_SHARED,
>> - dev_name(&dev->dev), i2c);
>> + ret = devm_request_irq(&dev->dev, irq, i2c_pxa_handler,
>> + IRQF_SHARED, dev_name(&dev->dev), i2c);
>> if (ret)
>> - goto ereqirq;
>> + goto emalloc;
>
> Same here.
>
>> }
>>
>> i2c_pxa_reset(i2c);
>> @@ -1261,15 +1262,9 @@ static int i2c_pxa_probe(struct platform_device *dev)
>> eadapt:
>> if (!i2c->use_pio)
>> free_irq(irq, i2c);
>
> The free_irq() call should also be removed since devm_request_irq() was used.
>
>> -ereqirq:
>> - clk_disable_unprepare(i2c->clk);
>> - iounmap(i2c->reg_base);
>> -eremap:
>> - clk_put(i2c->clk);
>> -eclk:
>> - kfree(i2c);
>> emalloc:
>> release_mem_region(res->start, resource_size(res));
>> +err_nothing_to_release:
>> return ret;
>> }
>>
>
> Best regards,
>
> Emil Goode
Hi All!
Ok, so there is literally nothing to do release anymore.
A good system Devres, I understand you want everyone to use it.
I also think it is also better to return directly then.
But who decides, Wolfram?
Would appreciate if I did not have to do more than one patch more.
And thanks Jingoo for spelling, etc.
Kind regards
Rickard Strandqvist
Hello,
I noticed one more thing.
On Fri, Jul 04, 2014 at 07:07:48PM +0200, Rickard Strandqvist wrote:
> 2014-07-04 11:10 GMT+02:00 Emil Goode <[email protected]>:
> > Hello Rickard,
> >
> > Since this is a probe function there is also no need to release the devm_*
> > resources in the i2c_pxa_remove function, this leads to double free.
> >
> > Also I have a few nit-pick comments below.
> >
> > On Thu, Jul 03, 2014 at 10:19:16PM +0200, Rickard Strandqvist wrote:
> >> Fix for possible null pointer dereferenc, and there is a risk for memory leak if something unexpected happens and the function returns.
> >> It now use Managed Device Resource instead.
> >>
> >> Signed-off-by: Rickard Strandqvist <[email protected]>
> >> ---
> >> drivers/i2c/busses/i2c-pxa.c | 37 ++++++++++++++++---------------------
> >> 1 file changed, 16 insertions(+), 21 deletions(-)
> >>
> >> diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
> >> index be671f7..2edb633 100644
> >> --- a/drivers/i2c/busses/i2c-pxa.c
> >> +++ b/drivers/i2c/busses/i2c-pxa.c
> >> @@ -1141,10 +1141,10 @@ static int i2c_pxa_probe(struct platform_device *dev)
> >> struct resource *res = NULL;
> >> int ret, irq;
> >>
> >> - i2c = kzalloc(sizeof(struct pxa_i2c), GFP_KERNEL);
> >> + i2c = devm_kzalloc(&dev->dev, sizeof(struct pxa_i2c), GFP_KERNEL);
> >> if (!i2c) {
> >> ret = -ENOMEM;
> >> - goto emalloc;
> >> + goto err_nothing_to_release;
> >
> > Perhaps its a good idea to return directly here, then the label
> > err_nothing_to_release can be removed.
> >
> >> }
> >>
> >> /* Default adapter num to device id; i2c_pxa_probe_dt can override. */
> >> @@ -1154,18 +1154,19 @@ static int i2c_pxa_probe(struct platform_device *dev)
> >> if (ret > 0)
> >> ret = i2c_pxa_probe_pdata(dev, i2c, &i2c_type);
> >> if (ret < 0)
> >> - goto eclk;
> >> + goto err_nothing_to_release;
> >
> > Same here.
> >
> >>
> >> res = platform_get_resource(dev, IORESOURCE_MEM, 0);
> >> irq = platform_get_irq(dev, 0);
> >> if (res == NULL || irq < 0) {
> >> ret = -ENODEV;
> >> - goto eclk;
> >> + goto err_nothing_to_release;
> >
> > Same here.
> >
> >> }
> >>
> >> - if (!request_mem_region(res->start, resource_size(res), res->name)) {
> >> + if (!devm_request_mem_region(&dev->dev, res->start,
> >> + resource_size(res), res->name)) {
> >> ret = -ENOMEM;
> >> - goto eclk;
> >> + goto emalloc;
> >
> > We could also return directly here since the release_mem_region call should
> > be removed, as mentioned in Jingoos reply.
> >
> >> }
> >>
> >> i2c->adap.owner = THIS_MODULE;
> >> @@ -1176,16 +1177,16 @@ static int i2c_pxa_probe(struct platform_device *dev)
> >>
> >> strlcpy(i2c->adap.name, "pxa_i2c-i2c", sizeof(i2c->adap.name));
> >>
> >> - i2c->clk = clk_get(&dev->dev, NULL);
> >> + i2c->clk = devm_clk_get(&dev->dev, NULL);
> >> if (IS_ERR(i2c->clk)) {
> >> ret = PTR_ERR(i2c->clk);
> >> - goto eclk;
> >> + goto emalloc;
> >
> > Same here.
> >
> >> }
> >>
> >> - i2c->reg_base = ioremap(res->start, resource_size(res));
> >> - if (!i2c->reg_base) {
> >> + i2c->reg_base = devm_ioremap_resource(&adev->dev, res));
> >> + if (IS_ERR(i2c->reg_base)) {
> >> ret = -EIO;
> >> - goto eremap;
> >> + goto emalloc;
> >
> > Same here.
> >
> >> }
> >>
> >> i2c->reg_ibmr = i2c->reg_base + pxa_reg_layout[i2c_type].ibmr;
> >> @@ -1227,10 +1228,10 @@ static int i2c_pxa_probe(struct platform_device *dev)
> >> i2c->adap.algo = &i2c_pxa_pio_algorithm;
> >> } else {
> >> i2c->adap.algo = &i2c_pxa_algorithm;
> >> - ret = request_irq(irq, i2c_pxa_handler, IRQF_SHARED,
> >> - dev_name(&dev->dev), i2c);
> >> + ret = devm_request_irq(&dev->dev, irq, i2c_pxa_handler,
> >> + IRQF_SHARED, dev_name(&dev->dev), i2c);
> >> if (ret)
> >> - goto ereqirq;
> >> + goto emalloc;
> >
> > Same here.
> >
> >> }
> >>
> >> i2c_pxa_reset(i2c);
> >> @@ -1261,15 +1262,9 @@ static int i2c_pxa_probe(struct platform_device *dev)
> >> eadapt:
> >> if (!i2c->use_pio)
> >> free_irq(irq, i2c);
> >
> > The free_irq() call should also be removed since devm_request_irq() was used.
> >
> >> -ereqirq:
> >> - clk_disable_unprepare(i2c->clk);
I think we should keep the clk_disable_unprepare() call.
> >> - iounmap(i2c->reg_base);
> >> -eremap:
> >> - clk_put(i2c->clk);
> >> -eclk:
> >> - kfree(i2c);
> >> emalloc:
> >> release_mem_region(res->start, resource_size(res));
> >> +err_nothing_to_release:
> >> return ret;
> >> }
> >>
> >
> > Best regards,
> >
> > Emil Goode
>
> Hi All!
>
> Ok, so there is literally nothing to do release anymore.
> A good system Devres, I understand you want everyone to use it.
>
> I also think it is also better to return directly then.
> But who decides, Wolfram?
Yes, Wolfram is the maintainer.
Personally I would do the devm_* convertion in a second patch.
Best regards,
Emil Goode
2014-07-04 19:24 GMT+02:00 Emil Goode <[email protected]>:
> Hello,
>
> I noticed one more thing.
>
> On Fri, Jul 04, 2014 at 07:07:48PM +0200, Rickard Strandqvist wrote:
>> 2014-07-04 11:10 GMT+02:00 Emil Goode <[email protected]>:
>> > Hello Rickard,
>> >
>> > Since this is a probe function there is also no need to release the devm_*
>> > resources in the i2c_pxa_remove function, this leads to double free.
>> >
>> > Also I have a few nit-pick comments below.
>> >
>> > On Thu, Jul 03, 2014 at 10:19:16PM +0200, Rickard Strandqvist wrote:
>> >> Fix for possible null pointer dereferenc, and there is a risk for memory leak if something unexpected happens and the function returns.
>> >> It now use Managed Device Resource instead.
>> >>
>> >> Signed-off-by: Rickard Strandqvist <[email protected]>
>> >> ---
>> >> drivers/i2c/busses/i2c-pxa.c | 37 ++++++++++++++++---------------------
>> >> 1 file changed, 16 insertions(+), 21 deletions(-)
>> >>
>> >> diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
>> >> index be671f7..2edb633 100644
>> >> --- a/drivers/i2c/busses/i2c-pxa.c
>> >> +++ b/drivers/i2c/busses/i2c-pxa.c
>> >> @@ -1141,10 +1141,10 @@ static int i2c_pxa_probe(struct platform_device *dev)
>> >> struct resource *res = NULL;
>> >> int ret, irq;
>> >>
>> >> - i2c = kzalloc(sizeof(struct pxa_i2c), GFP_KERNEL);
>> >> + i2c = devm_kzalloc(&dev->dev, sizeof(struct pxa_i2c), GFP_KERNEL);
>> >> if (!i2c) {
>> >> ret = -ENOMEM;
>> >> - goto emalloc;
>> >> + goto err_nothing_to_release;
>> >
>> > Perhaps its a good idea to return directly here, then the label
>> > err_nothing_to_release can be removed.
>> >
>> >> }
>> >>
>> >> /* Default adapter num to device id; i2c_pxa_probe_dt can override. */
>> >> @@ -1154,18 +1154,19 @@ static int i2c_pxa_probe(struct platform_device *dev)
>> >> if (ret > 0)
>> >> ret = i2c_pxa_probe_pdata(dev, i2c, &i2c_type);
>> >> if (ret < 0)
>> >> - goto eclk;
>> >> + goto err_nothing_to_release;
>> >
>> > Same here.
>> >
>> >>
>> >> res = platform_get_resource(dev, IORESOURCE_MEM, 0);
>> >> irq = platform_get_irq(dev, 0);
>> >> if (res == NULL || irq < 0) {
>> >> ret = -ENODEV;
>> >> - goto eclk;
>> >> + goto err_nothing_to_release;
>> >
>> > Same here.
>> >
>> >> }
>> >>
>> >> - if (!request_mem_region(res->start, resource_size(res), res->name)) {
>> >> + if (!devm_request_mem_region(&dev->dev, res->start,
>> >> + resource_size(res), res->name)) {
>> >> ret = -ENOMEM;
>> >> - goto eclk;
>> >> + goto emalloc;
>> >
>> > We could also return directly here since the release_mem_region call should
>> > be removed, as mentioned in Jingoos reply.
>> >
>> >> }
>> >>
>> >> i2c->adap.owner = THIS_MODULE;
>> >> @@ -1176,16 +1177,16 @@ static int i2c_pxa_probe(struct platform_device *dev)
>> >>
>> >> strlcpy(i2c->adap.name, "pxa_i2c-i2c", sizeof(i2c->adap.name));
>> >>
>> >> - i2c->clk = clk_get(&dev->dev, NULL);
>> >> + i2c->clk = devm_clk_get(&dev->dev, NULL);
>> >> if (IS_ERR(i2c->clk)) {
>> >> ret = PTR_ERR(i2c->clk);
>> >> - goto eclk;
>> >> + goto emalloc;
>> >
>> > Same here.
>> >
>> >> }
>> >>
>> >> - i2c->reg_base = ioremap(res->start, resource_size(res));
>> >> - if (!i2c->reg_base) {
>> >> + i2c->reg_base = devm_ioremap_resource(&adev->dev, res));
>> >> + if (IS_ERR(i2c->reg_base)) {
>> >> ret = -EIO;
>> >> - goto eremap;
>> >> + goto emalloc;
>> >
>> > Same here.
>> >
>> >> }
>> >>
>> >> i2c->reg_ibmr = i2c->reg_base + pxa_reg_layout[i2c_type].ibmr;
>> >> @@ -1227,10 +1228,10 @@ static int i2c_pxa_probe(struct platform_device *dev)
>> >> i2c->adap.algo = &i2c_pxa_pio_algorithm;
>> >> } else {
>> >> i2c->adap.algo = &i2c_pxa_algorithm;
>> >> - ret = request_irq(irq, i2c_pxa_handler, IRQF_SHARED,
>> >> - dev_name(&dev->dev), i2c);
>> >> + ret = devm_request_irq(&dev->dev, irq, i2c_pxa_handler,
>> >> + IRQF_SHARED, dev_name(&dev->dev), i2c);
>> >> if (ret)
>> >> - goto ereqirq;
>> >> + goto emalloc;
>> >
>> > Same here.
>> >
>> >> }
>> >>
>> >> i2c_pxa_reset(i2c);
>> >> @@ -1261,15 +1262,9 @@ static int i2c_pxa_probe(struct platform_device *dev)
>> >> eadapt:
>> >> if (!i2c->use_pio)
>> >> free_irq(irq, i2c);
>> >
>> > The free_irq() call should also be removed since devm_request_irq() was used.
>> >
>> >> -ereqirq:
>> >> - clk_disable_unprepare(i2c->clk);
>
> I think we should keep the clk_disable_unprepare() call.
>
>> >> - iounmap(i2c->reg_base);
>> >> -eremap:
>> >> - clk_put(i2c->clk);
>> >> -eclk:
>> >> - kfree(i2c);
>> >> emalloc:
>> >> release_mem_region(res->start, resource_size(res));
>> >> +err_nothing_to_release:
>> >> return ret;
>> >> }
>> >>
>> >
>> > Best regards,
>> >
>> > Emil Goode
>>
>> Hi All!
>>
>> Ok, so there is literally nothing to do release anymore.
>> A good system Devres, I understand you want everyone to use it.
>>
>> I also think it is also better to return directly then.
>> But who decides, Wolfram?
>
> Yes, Wolfram is the maintainer.
>
> Personally I would do the devm_* convertion in a second patch.
Hi
Ok then, Wolfram!
Keep only:
ereqirq:
clk_disable_unprepare(i2c->clk);
And let everyone else just return?
And Emil, as I said before, it would in that case the first patch just be:
emalloc:
- release_mem_region(res->start, resource_size(res));
+ if(res)
+ release_mem_region(res->start, resource_size(res));
It is rather pointless to add something in a patch, to remove it in the next.
Kind regards
Rickard Strandqvist
> Ok then, Wolfram!
>
> Keep only:
>
> ereqirq:
> clk_disable_unprepare(i2c->clk);
>
> And let everyone else just return?
I haven't looked at the details, but when you simply can return, do it.
> It is rather pointless to add something in a patch, to remove it in the next.
Yup, just say in the patch description that it fixes this bug.