From: Guenter Roeck <linux@roeck-us.net>
To: spi-devel-general@lists.sourceforge.net
Cc: linux-kernel@vger.kernel.org,
Grant Likely <grant.likely@secretlab.ca>,
Mark Brown <broonie@opensource.wolfsonmicro.com>,
Guenter Roeck <linux@roeck-us.net>,
Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>
Subject: [PATCH] Revert "spi/doc: spi_master_put must be followed up by kfree"
Date: Mon, 3 Sep 2012 13:26:26 -0700 [thread overview]
Message-ID: <1346703986-7849-1-git-send-email-linux@roeck-us.net> (raw)
Actually, spi_master_put() after spi_alloc_master() must _not_ be followed
by kfree(). The memory is already freed with the call to spi_master_put()
through spi_master_class, which registers a release function. Calling both
spi_master_put() and kfree() results in often nasty (and delayed) crashes
elsewhere in the kernel, often in the networking stack.
This reverts commit eb4af0f5349235df2e4a5057a72fc8962d00308a.
Cc: Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
drivers/spi/spi.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 2d9b5bb..6470750 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -1082,8 +1082,7 @@ static struct class spi_master_class = {
*
* The caller is responsible for assigning the bus number and initializing
* the master's methods before calling spi_register_master(); and (after errors
- * adding the device) calling spi_master_put() and kfree() to prevent a memory
- * leak.
+ * adding the device) calling spi_master_put() to prevent a memory leak.
*/
struct spi_master *spi_alloc_master(struct device *dev, unsigned size)
{
--
1.7.9.7
next reply other threads:[~2012-09-03 20:26 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-03 20:26 Guenter Roeck [this message]
2012-09-04 7:25 ` [PATCH] Revert "spi/doc: spi_master_put must be followed up by kfree" Uwe Kleine-König
2012-09-04 11:57 ` Guenter Roeck
2015-09-06 0:09 ` Applied "spi: Fix documentation of spi_alloc_master()" to the spi tree Mark Brown
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