x86/mm: Do not auto-massage page protections

[linux.git] / arch / x86 / include / asm / pgtable.h

diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 89d5c8886c856bfaefc3d1adaca2fc0b349f0a94..5f49b4ff0c248493f77cc12cadee0c2b6261c25d 100644 (file)
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -526,22 +526,39 @@ static inline pgprotval_t massage_pgprot(pgprot_t pgprot)
        return protval;
 }
 
+static inline pgprotval_t check_pgprot(pgprot_t pgprot)
+{
+       pgprotval_t massaged_val = massage_pgprot(pgprot);
+
+       /* mmdebug.h can not be included here because of dependencies */
+#ifdef CONFIG_DEBUG_VM
+       WARN_ONCE(pgprot_val(pgprot) != massaged_val,
+                 "attempted to set unsupported pgprot: %016llx "
+                 "bits: %016llx supported: %016llx\n",
+                 (u64)pgprot_val(pgprot),
+                 (u64)pgprot_val(pgprot) ^ massaged_val,
+                 (u64)__supported_pte_mask);
+#endif
+
+       return massaged_val;
+}
+
 static inline pte_t pfn_pte(unsigned long page_nr, pgprot_t pgprot)
 {
        return __pte(((phys_addr_t)page_nr << PAGE_SHIFT) |
-                    massage_pgprot(pgprot));
+                    check_pgprot(pgprot));
 }
 
 static inline pmd_t pfn_pmd(unsigned long page_nr, pgprot_t pgprot)
 {
        return __pmd(((phys_addr_t)page_nr << PAGE_SHIFT) |
-                    massage_pgprot(pgprot));
+                    check_pgprot(pgprot));
 }
 
 static inline pud_t pfn_pud(unsigned long page_nr, pgprot_t pgprot)
 {
        return __pud(((phys_addr_t)page_nr << PAGE_SHIFT) |
-                    massage_pgprot(pgprot));
+                    check_pgprot(pgprot));
 }
 
 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
@@ -553,7 +570,7 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
         * the newprot (if present):
         */
        val &= _PAGE_CHG_MASK;
-       val |= massage_pgprot(newprot) & ~_PAGE_CHG_MASK;
+       val |= check_pgprot(newprot) & ~_PAGE_CHG_MASK;
 
        return __pte(val);
 }
@@ -563,7 +580,7 @@ static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
        pmdval_t val = pmd_val(pmd);
 
        val &= _HPAGE_CHG_MASK;
-       val |= massage_pgprot(newprot) & ~_HPAGE_CHG_MASK;
+       val |= check_pgprot(newprot) & ~_HPAGE_CHG_MASK;
 
        return __pmd(val);
 }