From: Alexey Klimov <alexey.klimov@linaro.org> To: linux@roeck-us.net, linux-spi@vger.kernel.org, broonie@kernel.org Cc: linux-kernel@vger.kernel.org, djkurtz@chromium.org, klimov.linux@gmail.com, Alexey Klimov <alexey.klimov@linaro.org>, Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de> 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 [thread overview] Message-ID: <1441493214-12994-1-git-send-email-alexey.klimov@linaro.org> (raw) 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
WARNING: multiple messages have this Message-ID (diff)
From: Alexey Klimov <alexey.klimov-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> To: linux-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org, linux-spi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, broonie-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, djkurtz-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org, klimov.linux-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, Alexey Klimov <alexey.klimov-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>, Uwe Kleine-Koenig <u.kleine-koenig-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org> 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 [thread overview] Message-ID: <1441493214-12994-1-git-send-email-alexey.klimov@linaro.org> (raw) From: Guenter Roeck <linux-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org> 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-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org> Signed-off-by: Guenter Roeck <linux-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org> Signed-off-by: Alexey Klimov <alexey.klimov-QSEj5FYQhm4dnm+yROfE0A@public.gmane.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 -- To unsubscribe from this list: send the line "unsubscribe linux-spi" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html
next reply other threads:[~2015-09-05 22:47 UTC|newest] Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top 2015-09-05 22:46 Alexey Klimov [this message] 2015-09-05 22:46 ` [PATCH RESEND 1/1] Revert "spi/doc: spi_master_put must be followed up by kfree" Alexey Klimov 2015-09-06 0:04 ` Mark Brown 2015-09-06 0:04 ` Mark Brown
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