* Re: [PATCH 3/4] dell-laptop: Fix allocating & freeing SMI buffer page
2015-06-21 8:41 ` [PATCH 3/4] dell-laptop: Fix allocating & freeing SMI buffer page Pali Rohár
@ 2015-06-22 8:46 ` Michal Hocko
2015-06-22 19:04 ` Darren Hart
2015-06-23 8:11 ` [PATCH] " Pali Rohár
2 siblings, 0 replies; 5+ messages in thread
From: Michal Hocko @ 2015-06-22 8:46 UTC (permalink / raw)
To: Pali Rohár
Cc: Darren Hart, Matthew Garrett, platform-driver-x86, linux-kernel,
linux-mm
On Sun 21-06-15 10:41:03, Pali Rohar wrote:
> This commit fix kernel crash when probing for rfkill devices in dell-laptop
> driver failed. Function free_page() was incorrectly used on struct page *
> instead of virtual address of SMI buffer.
>
> This commit also simplify allocating page for SMI buffer by using
> __get_free_page() function instead of sequential call of functions
> alloc_page() and page_address().
>
> Signed-off-by: Pali Rohar <pali.rohar@gmail.com>
Looks good to me.
FWIW
Acked-by: Michal Hocko <mhocko@suse.cz>
> ---
> drivers/platform/x86/dell-laptop.c | 8 +++-----
> 1 file changed, 3 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/platform/x86/dell-laptop.c b/drivers/platform/x86/dell-laptop.c
> index aaef335..0a91599 100644
> --- a/drivers/platform/x86/dell-laptop.c
> +++ b/drivers/platform/x86/dell-laptop.c
> @@ -306,7 +306,6 @@ static const struct dmi_system_id dell_quirks[] __initconst = {
> };
>
> static struct calling_interface_buffer *buffer;
> -static struct page *bufferpage;
> static DEFINE_MUTEX(buffer_mutex);
>
> static int hwswitch_state;
> @@ -2097,12 +2096,11 @@ static int __init dell_init(void)
> * Allocate buffer below 4GB for SMI data--only 32-bit physical addr
> * is passed to SMI handler.
> */
> - bufferpage = alloc_page(GFP_KERNEL | GFP_DMA32);
> - if (!bufferpage) {
> + buffer = (void *)__get_free_page(GFP_KERNEL | GFP_DMA32);
> + if (!buffer) {
> ret = -ENOMEM;
> goto fail_buffer;
> }
> - buffer = page_address(bufferpage);
>
> ret = dell_setup_rfkill();
>
> @@ -2165,7 +2163,7 @@ static int __init dell_init(void)
> fail_backlight:
> dell_cleanup_rfkill();
> fail_rfkill:
> - free_page((unsigned long)bufferpage);
> + free_page((unsigned long)buffer);
> fail_buffer:
> platform_device_del(platform_device);
> fail_platform_device2:
> --
> 1.7.9.5
>
--
Michal Hocko
SUSE Labs
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^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH 3/4] dell-laptop: Fix allocating & freeing SMI buffer page
2015-06-21 8:41 ` [PATCH 3/4] dell-laptop: Fix allocating & freeing SMI buffer page Pali Rohár
2015-06-22 8:46 ` Michal Hocko
@ 2015-06-22 19:04 ` Darren Hart
2015-06-23 8:11 ` [PATCH] " Pali Rohár
2 siblings, 0 replies; 5+ messages in thread
From: Darren Hart @ 2015-06-22 19:04 UTC (permalink / raw)
To: Pali Rohár
Cc: Matthew Garrett, Michal Hocko, platform-driver-x86, linux-kernel,
linux-mm
On Sun, Jun 21, 2015 at 10:41:03AM +0200, Pali Rohar wrote:
> This commit fix kernel crash when probing for rfkill devices in dell-laptop
> driver failed. Function free_page() was incorrectly used on struct page *
> instead of virtual address of SMI buffer.
>
> This commit also simplify allocating page for SMI buffer by using
> __get_free_page() function instead of sequential call of functions
> alloc_page() and page_address().
>
> Signed-off-by: Pali Rohar <pali.rohar@gmail.com>
Looks good - please resend with Cc to stable - that's the simplest path to
inclusion in stable.
> ---
> drivers/platform/x86/dell-laptop.c | 8 +++-----
> 1 file changed, 3 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/platform/x86/dell-laptop.c b/drivers/platform/x86/dell-laptop.c
> index aaef335..0a91599 100644
> --- a/drivers/platform/x86/dell-laptop.c
> +++ b/drivers/platform/x86/dell-laptop.c
> @@ -306,7 +306,6 @@ static const struct dmi_system_id dell_quirks[] __initconst = {
> };
>
> static struct calling_interface_buffer *buffer;
> -static struct page *bufferpage;
> static DEFINE_MUTEX(buffer_mutex);
>
> static int hwswitch_state;
> @@ -2097,12 +2096,11 @@ static int __init dell_init(void)
> * Allocate buffer below 4GB for SMI data--only 32-bit physical addr
> * is passed to SMI handler.
> */
> - bufferpage = alloc_page(GFP_KERNEL | GFP_DMA32);
> - if (!bufferpage) {
> + buffer = (void *)__get_free_page(GFP_KERNEL | GFP_DMA32);
> + if (!buffer) {
> ret = -ENOMEM;
> goto fail_buffer;
> }
> - buffer = page_address(bufferpage);
>
> ret = dell_setup_rfkill();
>
> @@ -2165,7 +2163,7 @@ static int __init dell_init(void)
> fail_backlight:
> dell_cleanup_rfkill();
> fail_rfkill:
> - free_page((unsigned long)bufferpage);
> + free_page((unsigned long)buffer);
> fail_buffer:
> platform_device_del(platform_device);
> fail_platform_device2:
> --
> 1.7.9.5
>
>
--
Darren Hart
Intel Open Source Technology Center
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^ permalink raw reply [flat|nested] 5+ messages in thread* [PATCH] dell-laptop: Fix allocating & freeing SMI buffer page
2015-06-21 8:41 ` [PATCH 3/4] dell-laptop: Fix allocating & freeing SMI buffer page Pali Rohár
2015-06-22 8:46 ` Michal Hocko
2015-06-22 19:04 ` Darren Hart
@ 2015-06-23 8:11 ` Pali Rohár
2015-06-25 3:23 ` Darren Hart
2 siblings, 1 reply; 5+ messages in thread
From: Pali Rohár @ 2015-06-23 8:11 UTC (permalink / raw)
To: Darren Hart, Matthew Garrett, Michal Hocko
Cc: platform-driver-x86, linux-kernel, linux-mm, Pali Rohár, stable
This commit fix kernel crash when probing for rfkill devices in dell-laptop
driver failed. Function free_page() was incorrectly used on struct page *
instead of virtual address of SMI buffer.
This commit also simplify allocating page for SMI buffer by using
__get_free_page() function instead of sequential call of functions
alloc_page() and page_address().
Signed-off-by: Pali RohA!r <pali.rohar@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: stable@vger.kernel.org
---
drivers/platform/x86/dell-laptop.c | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)
diff --git a/drivers/platform/x86/dell-laptop.c b/drivers/platform/x86/dell-laptop.c
index d688d80..2c1d5f5 100644
--- a/drivers/platform/x86/dell-laptop.c
+++ b/drivers/platform/x86/dell-laptop.c
@@ -305,7 +305,6 @@ static const struct dmi_system_id dell_quirks[] __initconst = {
};
static struct calling_interface_buffer *buffer;
-static struct page *bufferpage;
static DEFINE_MUTEX(buffer_mutex);
static int hwswitch_state;
@@ -1896,12 +1895,11 @@ static int __init dell_init(void)
* Allocate buffer below 4GB for SMI data--only 32-bit physical addr
* is passed to SMI handler.
*/
- bufferpage = alloc_page(GFP_KERNEL | GFP_DMA32);
- if (!bufferpage) {
+ buffer = (void *)__get_free_page(GFP_KERNEL | GFP_DMA32);
+ if (!buffer) {
ret = -ENOMEM;
goto fail_buffer;
}
- buffer = page_address(bufferpage);
ret = dell_setup_rfkill();
@@ -1965,7 +1963,7 @@ fail_backlight:
cancel_delayed_work_sync(&dell_rfkill_work);
dell_cleanup_rfkill();
fail_rfkill:
- free_page((unsigned long)bufferpage);
+ free_page((unsigned long)buffer);
fail_buffer:
platform_device_del(platform_device);
fail_platform_device2:
--
1.7.10.4
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^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH] dell-laptop: Fix allocating & freeing SMI buffer page
2015-06-23 8:11 ` [PATCH] " Pali Rohár
@ 2015-06-25 3:23 ` Darren Hart
0 siblings, 0 replies; 5+ messages in thread
From: Darren Hart @ 2015-06-25 3:23 UTC (permalink / raw)
To: Pali Rohár
Cc: Matthew Garrett, Michal Hocko, platform-driver-x86, linux-kernel,
linux-mm, stable
On Tue, Jun 23, 2015 at 10:11:19AM +0200, Pali Rohar wrote:
> This commit fix kernel crash when probing for rfkill devices in dell-laptop
> driver failed. Function free_page() was incorrectly used on struct page *
> instead of virtual address of SMI buffer.
>
> This commit also simplify allocating page for SMI buffer by using
> __get_free_page() function instead of sequential call of functions
> alloc_page() and page_address().
>
> Signed-off-by: Pali Rohar <pali.rohar@gmail.com>
> Acked-by: Michal Hocko <mhocko@suse.cz>
> Cc: stable@vger.kernel.org
Queued, thanks Pali.
--
Darren Hart
Intel Open Source Technology Center
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^ permalink raw reply [flat|nested] 5+ messages in thread