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| author | Pali Rohár <pali.rohar@gmail.com> | 2015-06-23 10:11:19 +0200 |
|---|---|---|
| committer | Zefan Li <lizefan@huawei.com> | 2015-10-22 09:20:06 +0800 |
| commit | 800e58ae21796a472f39cd6d0601c87b297409af (patch) | |
| tree | acc9389a960cf9ebde2078de4e731b3f76ef69c2 | |
| parent | 019db118fefae4f5e792b007a73474d1d0ef1975 (diff) | |
| download | lwn-800e58ae21796a472f39cd6d0601c87b297409af.tar.gz lwn-800e58ae21796a472f39cd6d0601c87b297409af.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>
[lizf: Backported to 3.4: adjust context]
Signed-off-by: Zefan Li <lizefan@huawei.com>
| -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 e6c08ee8d46c..3d6759179f1c 100644 --- a/drivers/platform/x86/dell-laptop.c +++ b/drivers/platform/x86/dell-laptop.c @@ -216,7 +216,6 @@ static struct dmi_system_id __devinitdata dell_quirks[] = { }; static struct calling_interface_buffer *buffer; -static struct page *bufferpage; static DEFINE_MUTEX(buffer_mutex); static int hwswitch_state; @@ -714,11 +713,10 @@ 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); + buffer = (void *)__get_free_page(GFP_KERNEL | GFP_DMA32); - if (!bufferpage) + if (!buffer) goto fail_buffer; - buffer = page_address(bufferpage); ret = dell_setup_rfkill(); @@ -787,7 +785,7 @@ fail_backlight: fail_filter: 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: |