| Server IP : 49.231.201.246 / Your IP : 216.73.216.149 Web Server : Apache/2.4.18 (Ubuntu) System : Linux 246 4.4.0-210-generic #242-Ubuntu SMP Fri Apr 16 09:57:56 UTC 2021 x86_64 User : root ( 0) PHP Version : 7.0.33-0ubuntu0.16.04.16 Disable Function : exec,passthru,shell_exec,system,proc_open,popen,pcntl_exec MySQL : OFF | cURL : ON | WGET : ON | Perl : ON | Python : ON | Sudo : ON | Pkexec : ON Directory : /proc/11585/task/11585/root/usr/src/linux-headers-4.4.0-210/arch/x86/include/asm/ |
Upload File : |
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_PGTABLE_INVERT_H
#define _ASM_PGTABLE_INVERT_H 1
#ifndef __ASSEMBLY__
/*
* A clear pte value is special, and doesn't get inverted.
*
* Note that even users that only pass a pgprot_t (rather
* than a full pte) won't trigger the special zero case,
* because even PAGE_NONE has _PAGE_PROTNONE | _PAGE_ACCESSED
* set. So the all zero case really is limited to just the
* cleared page table entry case.
*/
static inline bool __pte_needs_invert(u64 val)
{
return val && !(val & _PAGE_PRESENT);
}
/* Get a mask to xor with the page table entry to get the correct pfn. */
static inline u64 protnone_mask(u64 val)
{
return __pte_needs_invert(val) ? ~0ull : 0;
}
static inline u64 flip_protnone_guard(u64 oldval, u64 val, u64 mask)
{
/*
* When a PTE transitions from NONE to !NONE or vice-versa
* invert the PFN part to stop speculation.
* pte_pfn undoes this when needed.
*/
if (__pte_needs_invert(oldval) != __pte_needs_invert(val))
val = (val & ~mask) | (~val & mask);
return val;
}
#endif /* __ASSEMBLY__ */
#endif