25 lines
704 B
C
25 lines
704 B
C
|
// SPDX-License-Identifier: GPL-2.0-only
|
||
|
|
|
||
|
|
#include <linux/uaccess.h>
|
||
|
|
#include <linux/kernel.h>
|
||
|
|
|
||
|
|
#ifdef CONFIG_X86_64
|
||
|
|
bool copy_from_kernel_nofault_allowed(const void *unsafe_src, size_t size)
|
||
|
|
{
|
||
|
|
unsigned long vaddr = (unsigned long)unsafe_src;
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Range covering the highest possible canonical userspace address
|
||
|
|
* as well as non-canonical address range. For the canonical range
|
||
|
|
* we also need to include the userspace guard page.
|
||
|
|
*/
|
||
|
|
return vaddr >= TASK_SIZE_MAX + PAGE_SIZE &&
|
||
|
|
__is_canonical_address(vaddr, boot_cpu_data.x86_virt_bits);
|
||
|
|
}
|
||
|
|
#else
|
||
|
|
bool copy_from_kernel_nofault_allowed(const void *unsafe_src, size_t size)
|
||
|
|
{
|
||
|
|
return (unsigned long)unsafe_src >= TASK_SIZE_MAX;
|
||
|
|
}
|
||
|
|
#endif
|