Revision 1e8143db755f745a9842984de5e8b423f583aea2 authored by Linus Torvalds on 27 May 2016, 20:56:02 UTC, committed by Linus Torvalds on 27 May 2016, 20:56:02 UTC
Pull x86 platform driver updates from Darren Hart: "Mostly minor updates and cleanups. One new power management controller driver for Intel Core SoCs. platform/x86: - Add PMC Driver for Intel Core SoC dell-rbtn: - Ignore ACPI notifications if device is suspended thinkpad_acpi: - save kbdlight state on suspend and restore it on resume intel_menlow: - reduce code duplication asus-wmi: - provide access to ALS control ideapad-laptop: - add a new WMI string for ESC key surfacepro3_button: - Add a warning when switching to tablet mode sony-laptop: - Avoid oops on module unload for older laptops intel_telemetry: - Constify telemetry_core_ops structures fujitsu-laptop: - Use IS_ENABLED() instead of checking for built-in or module asus-laptop: - correct error handling in sysfs_acpi_set - remove redundant initializers - correct error handling in asus_read_brightness() fujitsu-laptop: - Support radio LED" * tag 'platform-drivers-x86-v4.7-1' of git://git.infradead.org/users/dvhart/linux-platform-drivers-x86: platform/x86: Add PMC Driver for Intel Core SoC dell-rbtn: Ignore ACPI notifications if device is suspended thinkpad_acpi: save kbdlight state on suspend and restore it on resume intel_menlow: reduce code duplication asus-wmi: provide access to ALS control ideapad-laptop: add a new WMI string for ESC key surfacepro3_button: Add a warning when switching to tablet mode sony-laptop: Avoid oops on module unload for older laptops intel_telemetry: Constify telemetry_core_ops structures fujitsu-laptop: Use IS_ENABLED() instead of checking for built-in or module asus-laptop: correct error handling in sysfs_acpi_set asus-laptop: remove redundant initializers asus-laptop: correct error handling in asus_read_brightness() fujitsu-laptop: Support radio LED
maccess.c
/*
* Access kernel memory without faulting.
*/
#include <linux/export.h>
#include <linux/mm.h>
#include <linux/uaccess.h>
/**
* probe_kernel_read(): safely attempt to read from a location
* @dst: pointer to the buffer that shall take the data
* @src: address to read from
* @size: size of the data chunk
*
* Safely read from address @src to the buffer at @dst. If a kernel fault
* happens, handle that and return -EFAULT.
*
* We ensure that the copy_from_user is executed in atomic context so that
* do_page_fault() doesn't attempt to take mmap_sem. This makes
* probe_kernel_read() suitable for use within regions where the caller
* already holds mmap_sem, or other locks which nest inside mmap_sem.
*/
long __weak probe_kernel_read(void *dst, const void *src, size_t size)
__attribute__((alias("__probe_kernel_read")));
long __probe_kernel_read(void *dst, const void *src, size_t size)
{
long ret;
mm_segment_t old_fs = get_fs();
set_fs(KERNEL_DS);
pagefault_disable();
ret = __copy_from_user_inatomic(dst,
(__force const void __user *)src, size);
pagefault_enable();
set_fs(old_fs);
return ret ? -EFAULT : 0;
}
EXPORT_SYMBOL_GPL(probe_kernel_read);
/**
* probe_kernel_write(): safely attempt to write to a location
* @dst: address to write to
* @src: pointer to the data that shall be written
* @size: size of the data chunk
*
* Safely write to address @dst from the buffer at @src. If a kernel fault
* happens, handle that and return -EFAULT.
*/
long __weak probe_kernel_write(void *dst, const void *src, size_t size)
__attribute__((alias("__probe_kernel_write")));
long __probe_kernel_write(void *dst, const void *src, size_t size)
{
long ret;
mm_segment_t old_fs = get_fs();
set_fs(KERNEL_DS);
pagefault_disable();
ret = __copy_to_user_inatomic((__force void __user *)dst, src, size);
pagefault_enable();
set_fs(old_fs);
return ret ? -EFAULT : 0;
}
EXPORT_SYMBOL_GPL(probe_kernel_write);
/**
* strncpy_from_unsafe: - Copy a NUL terminated string from unsafe address.
* @dst: Destination address, in kernel space. This buffer must be at
* least @count bytes long.
* @src: Unsafe address.
* @count: Maximum number of bytes to copy, including the trailing NUL.
*
* Copies a NUL-terminated string from unsafe address to kernel buffer.
*
* On success, returns the length of the string INCLUDING the trailing NUL.
*
* If access fails, returns -EFAULT (some data may have been copied
* and the trailing NUL added).
*
* If @count is smaller than the length of the string, copies @count-1 bytes,
* sets the last byte of @dst buffer to NUL and returns @count.
*/
long strncpy_from_unsafe(char *dst, const void *unsafe_addr, long count)
{
mm_segment_t old_fs = get_fs();
const void *src = unsafe_addr;
long ret;
if (unlikely(count <= 0))
return 0;
set_fs(KERNEL_DS);
pagefault_disable();
do {
ret = __get_user(*dst++, (const char __user __force *)src++);
} while (dst[-1] && ret == 0 && src - unsafe_addr < count);
dst[-1] = '\0';
pagefault_enable();
set_fs(old_fs);
return ret ? -EFAULT : src - unsafe_addr;
}
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