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| author | Pali Rohár <pali.rohar@gmail.com> | 2015-06-23 10:11:19 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-08-03 09:29:16 -0700 |
| commit | 4e5c0806a19975c7d9ab9171af53d4e8125342aa (patch) | |
| tree | 710dec624b8dd3add544dd44ecd4073e4fe9b114 | |
| parent | a35b0d6cc0ec26fb607f6cf7bc7be5756c5de63e (diff) | |
| download | lwn-4e5c0806a19975c7d9ab9171af53d4e8125342aa.tar.gz lwn-4e5c0806a19975c7d9ab9171af53d4e8125342aa.zip | |
dell-laptop: Fix allocating & freeing SMI buffer page
commit b8830a4e71b15d0364ac8e6c55301eea73f211da upstream.
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 Rohár <pali.rohar@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/platform/x86/dell-laptop.c | 8 |
1 files changed, 3 insertions, 5 deletions
diff --git a/drivers/platform/x86/dell-laptop.c b/drivers/platform/x86/dell-laptop.c index d688d806a8a5..2c1d5f5432a9 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: |