Re: [PATCH] spi: omap2-mcspi: Fix the error handling in probe
On Thu, Aug 02, 2012 at 04:41:25PM +0530, Shubhrajyoti D wrote: The kfree() is taken care of by the spi core (spi_master_release() function) that is called once the last reference to the underlying struct device has been released. So the driver need not call kfree. Applied, thanks. -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ spi-devel-general mailing list spi-devel-general@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/spi-devel-general
Re: [PATCH] spi: omap2-mcspi: Fix the error handling in probe
On Wednesday 01 August 2012 08:37 PM, Guenter Roeck wrote:
On Wed, Aug 01, 2012 at 03:06:28PM +0530, Shubhrajyoti D wrote:
The kfree() is taken care of by the spi core (spi_master_release() function)
that is called once the last reference to the underlying struct device has
been released. So the driver need not call kfree.
Also the put was missed in some of the error handling fix the same.
There by fixing the missing device_put in some of the error paths.
Cc: Guenter Roeck li...@roeck-us.net
Reported-by: may be better here.
My bad. I should have done.
Signed-off-by: Shubhrajyoti D shubhrajy...@ti.com
Acked-by: Guenter Roeck li...@roeck-us.net
thanks.
I suspect that spi_master_put(master); may also be missing in
omap2_mcspi_remove(), but we'll need someone to confirm that.
Looks unlikely.
spi_master_put does a
...
if (master)
put_device(master-dev);
...
In remove I call
spi_unregister_master
...
*/
void spi_unregister_master(struct spi_master *master)
{
int dummy;
[...]
dummy = device_for_each_child(master-dev, NULL, __unregister);
device_unregister(master-dev);
}
and
void device_unregister(struct device *dev)
{
[..]
device_del(dev);
put_device(dev);
}
Hope my understanding is correct.
Thanks,
Guenter
---
drivers/spi/spi-omap2-mcspi.c |6 ++
1 files changed, 2 insertions(+), 4 deletions(-)
diff --git a/drivers/spi/spi-omap2-mcspi.c b/drivers/spi/spi-omap2-mcspi.c
index 7d46b15..b5035e2 100644
--- a/drivers/spi/spi-omap2-mcspi.c
+++ b/drivers/spi/spi-omap2-mcspi.c
@@ -1203,18 +1203,16 @@ static int __devinit omap2_mcspi_probe(struct
platform_device *pdev)
status = spi_register_master(master);
if (status 0)
-goto err_spi_register;
+goto disable_pm;
return status;
-err_spi_register:
-spi_master_put(master);
disable_pm:
pm_runtime_disable(pdev-dev);
dma_chnl_free:
kfree(mcspi-dma_channels);
free_master:
-kfree(master);
+spi_master_put(master);
platform_set_drvdata(pdev, NULL);
return status;
}
--
1.7.5.4
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[PATCH] spi: omap2-mcspi: Fix the error handling in probe
The kfree() is taken care of by the spi core (spi_master_release() function) that is called once the last reference to the underlying struct device has been released. So the driver need not call kfree. Also the put was missed in some of the error handling fix the same. There by fixing the missing device_put in some of the error paths. Acked-by: Guenter Roeck li...@roeck-us.net Reported-by: Guenter Roeck li...@roeck-us.net Signed-off-by: Shubhrajyoti D shubhrajy...@ti.com --- drivers/spi/spi-omap2-mcspi.c |6 ++ 1 files changed, 2 insertions(+), 4 deletions(-) diff --git a/drivers/spi/spi-omap2-mcspi.c b/drivers/spi/spi-omap2-mcspi.c index bc47781..b2fb141 100644 --- a/drivers/spi/spi-omap2-mcspi.c +++ b/drivers/spi/spi-omap2-mcspi.c @@ -1228,18 +1228,16 @@ static int __devinit omap2_mcspi_probe(struct platform_device *pdev) status = spi_register_master(master); if (status 0) - goto err_spi_register; + goto disable_pm; return status; -err_spi_register: - spi_master_put(master); disable_pm: pm_runtime_disable(pdev-dev); dma_chnl_free: kfree(mcspi-dma_channels); free_master: - kfree(master); + spi_master_put(master); platform_set_drvdata(pdev, NULL); return status; } -- 1.7.5.4 -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ spi-devel-general mailing list spi-devel-general@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/spi-devel-general
Re: [PATCH] spi: omap2-mcspi: Fix the error handling in probe
On Thu, Aug 02, 2012 at 03:37:13PM +0530, Shubhrajyoti wrote:
On Wednesday 01 August 2012 08:37 PM, Guenter Roeck wrote:
On Wed, Aug 01, 2012 at 03:06:28PM +0530, Shubhrajyoti D wrote:
The kfree() is taken care of by the spi core (spi_master_release()
function)
that is called once the last reference to the underlying struct device has
been released. So the driver need not call kfree.
Also the put was missed in some of the error handling fix the same.
There by fixing the missing device_put in some of the error paths.
Cc: Guenter Roeck li...@roeck-us.net
Reported-by: may be better here.
My bad. I should have done.
Signed-off-by: Shubhrajyoti D shubhrajy...@ti.com
Acked-by: Guenter Roeck li...@roeck-us.net
thanks.
I suspect that spi_master_put(master); may also be missing in
omap2_mcspi_remove(), but we'll need someone to confirm that.
Looks unlikely.
spi_master_put does a
...
if (master)
put_device(master-dev);
...
In remove I call
spi_unregister_master
...
*/
void spi_unregister_master(struct spi_master *master)
{
int dummy;
[...]
dummy = device_for_each_child(master-dev, NULL, __unregister);
device_unregister(master-dev);
}
and
void device_unregister(struct device *dev)
{
[..]
device_del(dev);
put_device(dev);
}
Hope my understanding is correct.
I think it is; I checked the refcount. spi_register_master increases
refcount from 1 to 3, and spi_unregister_master decreases it from 3 to 0.
Now, if _my_ understanding is correct, that means the data structure allocated
with spi_alloc_master, and specifically the device private data structure
(struct omap2_mcspi in your case), is freed with spi_unregister_master().
If so, it must not be accessed after the call to spi_unregister_master().
However, many drivers do access this data after the call to
spi_unregister_master(). spi-tegra.c is a good example, but there are many
others. Does that mean that those drivers access freed memory ?
Also, some other drivers do call spi_master_put() after spi_unregister_master(),
with no matching spi_master_get() (eg spi-topcliff-pch.c). Does that mean that
those drivers call spi_master_put() on free memory ?
Thanks,
Guenter
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[PATCH] spi: omap2-mcspi: Fix the error handling in probe
The kfree() is taken care of by the spi core (spi_master_release() function) that is called once the last reference to the underlying struct device has been released. So the driver need not call kfree. Also the put was missed in some of the error handling fix the same. There by fixing the missing device_put in some of the error paths. Cc: Guenter Roeck li...@roeck-us.net Signed-off-by: Shubhrajyoti D shubhrajy...@ti.com --- drivers/spi/spi-omap2-mcspi.c |6 ++ 1 files changed, 2 insertions(+), 4 deletions(-) diff --git a/drivers/spi/spi-omap2-mcspi.c b/drivers/spi/spi-omap2-mcspi.c index 7d46b15..b5035e2 100644 --- a/drivers/spi/spi-omap2-mcspi.c +++ b/drivers/spi/spi-omap2-mcspi.c @@ -1203,18 +1203,16 @@ static int __devinit omap2_mcspi_probe(struct platform_device *pdev) status = spi_register_master(master); if (status 0) - goto err_spi_register; + goto disable_pm; return status; -err_spi_register: - spi_master_put(master); disable_pm: pm_runtime_disable(pdev-dev); dma_chnl_free: kfree(mcspi-dma_channels); free_master: - kfree(master); + spi_master_put(master); platform_set_drvdata(pdev, NULL); return status; } -- 1.7.5.4 -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ spi-devel-general mailing list spi-devel-general@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/spi-devel-general
Re: [PATCH] spi: omap2-mcspi: Fix the error handling in probe
On Wed, Aug 01, 2012 at 03:06:28PM +0530, Shubhrajyoti D wrote: The kfree() is taken care of by the spi core (spi_master_release() function) that is called once the last reference to the underlying struct device has been released. So the driver need not call kfree. Also the put was missed in some of the error handling fix the same. There by fixing the missing device_put in some of the error paths. Cc: Guenter Roeck li...@roeck-us.net Reported-by: may be better here. Signed-off-by: Shubhrajyoti D shubhrajy...@ti.com Acked-by: Guenter Roeck li...@roeck-us.net I suspect that spi_master_put(master); may also be missing in omap2_mcspi_remove(), but we'll need someone to confirm that. Thanks, Guenter --- drivers/spi/spi-omap2-mcspi.c |6 ++ 1 files changed, 2 insertions(+), 4 deletions(-) diff --git a/drivers/spi/spi-omap2-mcspi.c b/drivers/spi/spi-omap2-mcspi.c index 7d46b15..b5035e2 100644 --- a/drivers/spi/spi-omap2-mcspi.c +++ b/drivers/spi/spi-omap2-mcspi.c @@ -1203,18 +1203,16 @@ static int __devinit omap2_mcspi_probe(struct platform_device *pdev) status = spi_register_master(master); if (status 0) - goto err_spi_register; + goto disable_pm; return status; -err_spi_register: - spi_master_put(master); disable_pm: pm_runtime_disable(pdev-dev); dma_chnl_free: kfree(mcspi-dma_channels); free_master: - kfree(master); + spi_master_put(master); platform_set_drvdata(pdev, NULL); return status; } -- 1.7.5.4 -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ spi-devel-general mailing list spi-devel-general@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/spi-devel-general
