}
extern void __sync_icache_dcache(pte_t pteval);
+bool pgattr_change_is_safe(u64 old, u64 new);
/*
* PTE bits configuration in the presence of hardware Dirty Bit Management
* PTE_DIRTY || (PTE_WRITE && !PTE_RDONLY)
*/
-static inline void __check_racy_pte_update(struct mm_struct *mm, pte_t *ptep,
+static inline void __check_safe_pte_update(struct mm_struct *mm, pte_t *ptep,
pte_t pte)
{
pte_t old_pte;
VM_WARN_ONCE(pte_write(old_pte) && !pte_dirty(pte),
"%s: racy dirty state clearing: 0x%016llx -> 0x%016llx",
__func__, pte_val(old_pte), pte_val(pte));
+ VM_WARN_ONCE(!pgattr_change_is_safe(pte_val(old_pte), pte_val(pte)),
+ "%s: unsafe attribute change: 0x%016llx -> 0x%016llx",
+ __func__, pte_val(old_pte), pte_val(pte));
}
static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr,
mte_sync_tags(old_pte, pte);
}
- __check_racy_pte_update(mm, ptep, pte);
+ __check_safe_pte_update(mm, ptep, pte);
set_pte(ptep, pte);
}
return phys;
}
-static bool pgattr_change_is_safe(u64 old, u64 new)
+bool pgattr_change_is_safe(u64 old, u64 new)
{
/*
* The following mapping attributes may be updated in live
pteval_t mask = PTE_PXN | PTE_RDONLY | PTE_WRITE | PTE_NG;
/* creating or taking down mappings is always safe */
- if (old == 0 || new == 0)
+ if (!pte_valid(__pte(old)) || !pte_valid(__pte(new)))
return true;
+ /* A live entry's pfn should not change */
+ if (pte_pfn(__pte(old)) != pte_pfn(__pte(new)))
+ return false;
+
/* live contiguous mappings may not be manipulated at all */
if ((old | new) & PTE_CONT)
return false;