From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guenter Roeck Subject: [PATCH 1/3] spi/stmp: Fix device remove function Date: Thu, 23 Aug 2012 20:08:47 -0700 Message-ID: <1345777729-19342-1-git-send-email-linux@roeck-us.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Mark Brown , Guenter Roeck To: spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Return-path: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: spi-devel-general-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: linux-spi.vger.kernel.org The call sequence spi_alloc_master/spi_register_master/spi_unregister_master is complete; it reduces the device reference count to zero, which results in device memory being freed. The remove function accesses the freed memory after the call to spi_unregister_master(), _and_ it calls spi_master_put on the freed memory. Acquire a reference to the SPI master device and release it after cleanup is complete (with the existing spi_master_put) to solve the problem. Also, the device subsystem ensures that the remove function is only called once, and resets device driver data to NULL. Remove the respective check and drop the unnecessaary call to platform_set_drvdata(). Signed-off-by: Guenter Roeck --- Note that this driver is impossible to build, since it depends on ARCH_STMP3XXX which is not defined anywhere. drivers/spi/spi-stmp.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) diff --git a/drivers/spi/spi-stmp.c b/drivers/spi/spi-stmp.c index 58e3852..911e904 100644 --- a/drivers/spi/spi-stmp.c +++ b/drivers/spi/spi-stmp.c @@ -594,9 +594,7 @@ static int __devexit stmp_spi_remove(struct platform_device *dev) struct stmp_spi *ss; struct spi_master *master; - master = platform_get_drvdata(dev); - if (master == NULL) - goto out0; + master = spi_master_get(platform_get_drvdata(dev)); ss = spi_master_get_devdata(master); spi_unregister_master(master); @@ -609,8 +607,6 @@ static int __devexit stmp_spi_remove(struct platform_device *dev) destroy_workqueue(ss->workqueue); iounmap(ss->regs); spi_master_put(master); - platform_set_drvdata(dev, NULL); -out0: return 0; } -- 1.7.9.7 ------------------------------------------------------------------------------ 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/