vasilito
ff4ff35918
Red Bear OS is a full fork. All sources must be available from git clone with zero network access. Removed gitignore rules that excluded fetched source trees under recipes/*/source/, local/recipes/kde/*/source/, local/recipes/qt/*/source/, and vendor source trees. Build artifacts (target/, build/, source.tar, *.o, *.so) remain excluded. 127291 files added — kernel, relibc, base, bootloader, pkgar, all KDE/Qt frameworks, mesa, wayland, DRM drivers, and every other recipe source.
42 lines
1.1 KiB
C
42 lines
1.1 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef _ASM_PGTABLE_INVERT_H
|
|
#define _ASM_PGTABLE_INVERT_H 1
|
|
|
|
#ifndef __ASSEMBLER__
|
|
|
|
/*
|
|
* 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 /* __ASSEMBLER__ */
|
|
|
|
#endif
|