0aae5fe841
commit f22cc87f6c1f771b57c407555cfefd811cdd9507 upstream For kernel mappings PAGE_PROTNONE is not necessarily set for a non present mapping, but the inversion logic explicitely checks for !PRESENT and PROT_NONE. Remove the PROT_NONE check and make the inversion unconditional for all not present mappings. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
32 lines
745 B
C
32 lines
745 B
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef _ASM_PGTABLE_INVERT_H
|
|
#define _ASM_PGTABLE_INVERT_H 1
|
|
|
|
#ifndef __ASSEMBLY__
|
|
|
|
static inline bool __pte_needs_invert(u64 val)
|
|
{
|
|
return !(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
|