From patchwork series 382090

https://patchwork.ozlabs.org//project/linuxppc-dev/list/?series=382090
linuxppc · Nov 14, 2023 · 1567de4 · 1567de4
1 parent 3ae115c
commit 1567de4
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Showing 3 changed files with 12 additions and 13 deletions.
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -17,12 +17,6 @@
 #define _PAGE_EXEC		0x00001 /* execute permission */
 #define _PAGE_WRITE		0x00002 /* write access allowed */
 #define _PAGE_READ		0x00004	/* read access allowed */
-#define _PAGE_NA		_PAGE_PRIVILEGED
-#define _PAGE_NAX		_PAGE_EXEC
-#define _PAGE_RO		_PAGE_READ
-#define _PAGE_ROX		(_PAGE_READ | _PAGE_EXEC)
-#define _PAGE_RW		(_PAGE_READ | _PAGE_WRITE)
-#define _PAGE_RWX		(_PAGE_READ | _PAGE_WRITE | _PAGE_EXEC)
 #define _PAGE_PRIVILEGED	0x00008 /* kernel access only */
 #define _PAGE_SAO		0x00010 /* Strong access order */
 #define _PAGE_NON_IDEMPOTENT	0x00020 /* non idempotent memory */
@@ -529,6 +523,9 @@ static inline bool pte_user(pte_t pte)
 }
 
 #define pte_access_permitted pte_access_permitted
+/*
+ * execute-only mappings return false
+ */
 static inline bool pte_access_permitted(pte_t pte, bool write)
 {
 	/*

diff --git a/arch/powerpc/include/asm/book3s/64/tlbflush.h b/arch/powerpc/include/asm/book3s/64/tlbflush.h
@@ -158,11 +158,6 @@ static inline void flush_tlb_fix_spurious_fault(struct vm_area_struct *vma,
 	 */
 }
 
-static inline bool __pte_protnone(unsigned long pte)
-{
-	return (pte & (pgprot_val(PAGE_NONE) | _PAGE_RWX)) == pgprot_val(PAGE_NONE);
-}
-
 static inline bool __pte_flags_need_flush(unsigned long oldval,
 					  unsigned long newval)
 {
@@ -179,8 +174,8 @@ static inline bool __pte_flags_need_flush(unsigned long oldval,
 	/*
 	 * We do not expect kernel mappings or non-PTEs or not-present PTEs.
 	 */
-	VM_WARN_ON_ONCE(!__pte_protnone(oldval) && oldval & _PAGE_PRIVILEGED);
-	VM_WARN_ON_ONCE(!__pte_protnone(newval) && newval & _PAGE_PRIVILEGED);
+	VM_WARN_ON_ONCE(oldval & _PAGE_PRIVILEGED);
+	VM_WARN_ON_ONCE(newval & _PAGE_PRIVILEGED);
 	VM_WARN_ON_ONCE(!(oldval & _PAGE_PTE));
 	VM_WARN_ON_ONCE(!(newval & _PAGE_PTE));
 	VM_WARN_ON_ONCE(!(oldval & _PAGE_PRESENT));

diff --git a/arch/powerpc/mm/book3s64/hash_utils.c b/arch/powerpc/mm/book3s64/hash_utils.c
@@ -310,9 +310,16 @@ unsigned long htab_convert_pte_flags(unsigned long pteflags, unsigned long flags
 			else
 				rflags |= 0x3;
 		}
+		VM_WARN_ONCE(!(pteflags & _PAGE_RWX), "no-access mapping request");
 	} else {
 		if (pteflags & _PAGE_RWX)
 			rflags |= 0x2;
+		/*
+		 * We should never hit this in normal fault handling because
+		 * a permission check (check_pte_access()) will bubble this
+		 * to higher level linux handler even for PAGE_NONE.
+		 */
+		VM_WARN_ONCE(!(pteflags & _PAGE_RWX), "no-access mapping request");
 		if (!((pteflags & _PAGE_WRITE) && (pteflags & _PAGE_DIRTY)))
 			rflags |= 0x1;
 	}