Messages in this thread Patch in this message | | | From | Alexey Klimov <> | Subject | [PATCH RESEND 1/1] Revert "spi/doc: spi_master_put must be followed up by kfree" | Date | Sun, 6 Sep 2015 01:46:54 +0300 |
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From: Guenter Roeck <linux@roeck-us.net>
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.
Link to patch and concerns: https://lkml.org/lkml/2012/9/3/269 or http://lkml.iu.edu/hypermail/linux/kernel/1209.0/00790.html
Alexey Klimov: This revert becomes valid after 94c69f765f1b4a658d96905ec59928e3e3e07e6a when spi-imx.c has been fixed and there is no need to call kfree() so comment for spi_alloc_master() should be fixed.
Cc: Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Alexey Klimov <alexey.klimov@linaro.org> --- 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 3abb390..a5f53de 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -1610,8 +1610,7 @@ 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) { -- 2.1.4
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