Support page table check PowerPC

arch/arm64/include/asm/pgtable.h

@@ -345,7 +345,7 @@ static inline void set_ptes(struct mm_struct *mm,
 			    unsigned long __always_unused addr,
 			    pte_t *ptep, pte_t pte, unsigned int nr)
 {
-	page_table_check_ptes_set(mm, ptep, pte, nr);
+	page_table_check_ptes_set(mm, addr, ptep, pte, nr);
 	__sync_cache_and_tags(pte, nr);
 
 	for (;;) {
@@ -540,15 +540,15 @@ static inline void __set_pte_at(struct mm_struct *mm,
 static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr,
 			      pmd_t *pmdp, pmd_t pmd)
 {
-	page_table_check_pmd_set(mm, pmdp, pmd);
+	page_table_check_pmd_set(mm, addr, pmdp, pmd);
 	return __set_pte_at(mm, addr, (pte_t *)pmdp, pmd_pte(pmd),
 						PMD_SIZE >> PAGE_SHIFT);
 }
 
 static inline void set_pud_at(struct mm_struct *mm, unsigned long addr,
 			      pud_t *pudp, pud_t pud)
 {
-	page_table_check_pud_set(mm, pudp, pud);
+	page_table_check_pud_set(mm, addr, pudp, pud);
 	return __set_pte_at(mm, addr, (pte_t *)pudp, pud_pte(pud),
 						PUD_SIZE >> PAGE_SHIFT);
 }
@@ -874,17 +874,17 @@ static inline int pgd_devmap(pgd_t pgd)
 #endif
 
 #ifdef CONFIG_PAGE_TABLE_CHECK
-static inline bool pte_user_accessible_page(pte_t pte)
+static inline bool pte_user_accessible_page(pte_t pte, unsigned long addr)
 {
 	return pte_present(pte) && (pte_user(pte) || pte_user_exec(pte));
 }
 
-static inline bool pmd_user_accessible_page(pmd_t pmd)
+static inline bool pmd_user_accessible_page(pmd_t pmd, unsigned long addr)
 {
 	return pmd_leaf(pmd) && !pmd_present_invalid(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd));
 }
 
-static inline bool pud_user_accessible_page(pud_t pud)
+static inline bool pud_user_accessible_page(pud_t pud, unsigned long addr)
 {
 	return pud_leaf(pud) && (pud_user(pud) || pud_user_exec(pud));
 }
@@ -953,7 +953,7 @@ static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
 {
 	pte_t pte = __pte(xchg_relaxed(&pte_val(*ptep), 0));
 
-	page_table_check_pte_clear(mm, pte);
+	page_table_check_pte_clear(mm, address, pte);
 
 	return pte;
 }
@@ -965,7 +965,7 @@ static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
 {
 	pmd_t pmd = __pmd(xchg_relaxed(&pmd_val(*pmdp), 0));
 
-	page_table_check_pmd_clear(mm, pmd);
+	page_table_check_pmd_clear(mm, address, pmd);
 
 	return pmd;
 }
@@ -1001,7 +1001,7 @@ static inline void pmdp_set_wrprotect(struct mm_struct *mm,
 static inline pmd_t pmdp_establish(struct vm_area_struct *vma,
 		unsigned long address, pmd_t *pmdp, pmd_t pmd)
 {
-	page_table_check_pmd_set(vma->vm_mm, pmdp, pmd);
+	page_table_check_pmd_set(vma->vm_mm, address, pmdp, pmd);
 	return __pmd(xchg_relaxed(&pmd_val(*pmdp), pmd_val(pmd)));
 }
 #endif

arch/powerpc/Kconfig

@@ -166,6 +166,7 @@ config PPC
 	select ARCH_STACKWALK
 	select ARCH_SUPPORTS_ATOMIC_RMW
 	select ARCH_SUPPORTS_DEBUG_PAGEALLOC	if PPC_BOOK3S || PPC_8xx || 40x
+	select ARCH_SUPPORTS_PAGE_TABLE_CHECK
 	select ARCH_USE_BUILTIN_BSWAP
 	select ARCH_USE_CMPXCHG_LOCKREF		if PPC64
 	select ARCH_USE_MEMTEST

arch/powerpc/include/asm/book3s/32/pgtable.h

@@ -201,6 +201,7 @@ void unmap_kernel_page(unsigned long va);
 #ifndef __ASSEMBLY__
 #include <linux/sched.h>
 #include <linux/threads.h>
+#include <linux/page_table_check.h>
 
 /* Bits to mask out from a PGD to get to the PUD page */
 #define PGD_MASKED_BITS		0
@@ -314,7 +315,11 @@ static inline int __ptep_test_and_clear_young(struct mm_struct *mm,
 static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
 				       pte_t *ptep)
 {
-	return __pte(pte_update(mm, addr, ptep, ~_PAGE_HASHPTE, 0, 0));
+	pte_t old_pte = __pte(pte_update(mm, addr, ptep, ~_PAGE_HASHPTE, 0, 0));
+
+	page_table_check_pte_clear(mm, addr, old_pte);
+
+	return old_pte;
 }
 
 #define __HAVE_ARCH_PTEP_SET_WRPROTECT

arch/powerpc/include/asm/book3s/64/pgtable.h

@@ -145,6 +145,8 @@
 #define PAGE_KERNEL_ROX	__pgprot(_PAGE_BASE | _PAGE_KERNEL_ROX)
 
 #ifndef __ASSEMBLY__
+#include <linux/page_table_check.h>
+
 /*
  * page table defines
  */
@@ -415,8 +417,11 @@ static inline void huge_ptep_set_wrprotect(struct mm_struct *mm,
 static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
 				       unsigned long addr, pte_t *ptep)
 {
-	unsigned long old = pte_update(mm, addr, ptep, ~0UL, 0, 0);
-	return __pte(old);
+	pte_t old_pte = __pte(pte_update(mm, addr, ptep, ~0UL, 0, 0));
+
+	page_table_check_pte_clear(mm, addr, old_pte);
+
+	return old_pte;
 }
 
 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR_FULL
@@ -425,11 +430,16 @@ static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm,
 					    pte_t *ptep, int full)
 {
 	if (full && radix_enabled()) {
+		pte_t old_pte;
+
 		/*
 		 * We know that this is a full mm pte clear and
 		 * hence can be sure there is no parallel set_pte.
 		 */
-		return radix__ptep_get_and_clear_full(mm, addr, ptep, full);
+		old_pte = radix__ptep_get_and_clear_full(mm, addr, ptep, full);
+		page_table_check_pte_clear(mm, addr, old_pte);
+
+		return old_pte;
 	}
 	return ptep_get_and_clear(mm, addr, ptep);
 }
@@ -538,6 +548,12 @@ static inline bool pte_access_permitted(pte_t pte, bool write)
 	return arch_pte_access_permitted(pte_val(pte), write, 0);
 }
 
+#define pte_user_accessible_page pte_user_accessible_page
+static inline bool pte_user_accessible_page(pte_t pte, unsigned long addr)
+{
+	return pte_present(pte) && pte_user(pte);
+}
+
 /*
  * Conversion functions: convert a page and protection to a page entry,
  * and a page entry and page directory to the page they refer to.
@@ -881,6 +897,7 @@ static inline int pud_present(pud_t pud)
 
 extern struct page *pud_page(pud_t pud);
 extern struct page *pmd_page(pmd_t pmd);
+
 static inline pte_t pud_pte(pud_t pud)
 {
 	return __pte_raw(pud_raw(pud));
@@ -926,6 +943,12 @@ static inline bool pud_access_permitted(pud_t pud, bool write)
 	return pte_access_permitted(pud_pte(pud), write);
 }
 
+#define pud_user_accessible_page pud_user_accessible_page
+static inline bool pud_user_accessible_page(pud_t pud, unsigned long addr)
+{
+	return pte_user_accessible_page(pud_pte(pud), addr);
+}
+
 #define __p4d_raw(x)	((p4d_t) { __pgd_raw(x) })
 static inline __be64 p4d_raw(p4d_t x)
 {
@@ -1101,6 +1124,12 @@ static inline bool pmd_access_permitted(pmd_t pmd, bool write)
 	return pte_access_permitted(pmd_pte(pmd), write);
 }
 
+#define pmd_user_accessible_page pmd_user_accessible_page
+static inline bool pmd_user_accessible_page(pmd_t pmd, unsigned long addr)
+{
+	return pte_user_accessible_page(pmd_pte(pmd), addr);
+}
+
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 extern pmd_t pfn_pmd(unsigned long pfn, pgprot_t pgprot);
 extern pud_t pfn_pud(unsigned long pfn, pgprot_t pgprot);
@@ -1325,19 +1354,34 @@ extern int pudp_test_and_clear_young(struct vm_area_struct *vma,
 static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
 					    unsigned long addr, pmd_t *pmdp)
 {
-	if (radix_enabled())
-		return radix__pmdp_huge_get_and_clear(mm, addr, pmdp);
-	return hash__pmdp_huge_get_and_clear(mm, addr, pmdp);
+	pmd_t old_pmd;
+
+	if (radix_enabled()) {
+		old_pmd = radix__pmdp_huge_get_and_clear(mm, addr, pmdp);
+	} else {
+		old_pmd = hash__pmdp_huge_get_and_clear(mm, addr, pmdp);
+	}
+
+	page_table_check_pmd_clear(mm, addr, old_pmd);
+
+	return old_pmd;
 }
 
 #define __HAVE_ARCH_PUDP_HUGE_GET_AND_CLEAR
 static inline pud_t pudp_huge_get_and_clear(struct mm_struct *mm,
 					    unsigned long addr, pud_t *pudp)
 {
-	if (radix_enabled())
-		return radix__pudp_huge_get_and_clear(mm, addr, pudp);
-	BUG();
-	return *pudp;
+	pud_t old_pud;
+
+	if (radix_enabled()) {
+		old_pud = radix__pudp_huge_get_and_clear(mm, addr, pudp);
+	} else {
+		BUG();
+	}
+
+	page_table_check_pud_clear(mm, addr, old_pud);
+
+	return old_pud;
 }
 
 static inline pmd_t pmdp_collapse_flush(struct vm_area_struct *vma,
@@ -1453,16 +1497,14 @@ static inline bool is_pte_rw_upgrade(unsigned long old_val, unsigned long new_va
 /*
  * Like pmd_huge() and pmd_large(), but works regardless of config options
  */
-#define pmd_is_leaf pmd_is_leaf
-#define pmd_leaf pmd_is_leaf
-static inline bool pmd_is_leaf(pmd_t pmd)
+#define pmd_leaf pmd_leaf
+static inline bool pmd_leaf(pmd_t pmd)
 {
 	return !!(pmd_raw(pmd) & cpu_to_be64(_PAGE_PTE));
 }
 
-#define pud_is_leaf pud_is_leaf
-#define pud_leaf pud_is_leaf
-static inline bool pud_is_leaf(pud_t pud)
+#define pud_leaf pud_leaf
+static inline bool pud_leaf(pud_t pud)
 {
 	return !!(pud_raw(pud) & cpu_to_be64(_PAGE_PTE));
 }

arch/powerpc/include/asm/pgtable.h

@@ -44,6 +44,8 @@ struct mm_struct;
 void set_ptes(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
 		pte_t pte, unsigned int nr);
 #define set_ptes set_ptes
+void set_pte_at_unchecked(struct mm_struct *mm, unsigned long addr,
+			  pte_t *ptep, pte_t pte);
 #define update_mmu_cache(vma, addr, ptep) \
 	update_mmu_cache_range(NULL, vma, addr, ptep, 1)
 
@@ -180,30 +182,6 @@ static inline void pte_frag_set(mm_context_t *ctx, void *p)
 }
 #endif
 
-#ifndef pmd_is_leaf
-#define pmd_is_leaf pmd_is_leaf
-static inline bool pmd_is_leaf(pmd_t pmd)
-{
-	return false;
-}
-#endif
-
-#ifndef pud_is_leaf
-#define pud_is_leaf pud_is_leaf
-static inline bool pud_is_leaf(pud_t pud)
-{
-	return false;
-}
-#endif
-
-#ifndef p4d_is_leaf
-#define p4d_is_leaf p4d_is_leaf
-static inline bool p4d_is_leaf(p4d_t p4d)
-{
-	return false;
-}
-#endif
-
 #define pmd_pgtable pmd_pgtable
 static inline pgtable_t pmd_pgtable(pmd_t pmd)
 {
@@ -237,6 +215,46 @@ static inline bool arch_supports_memmap_on_memory(unsigned long vmemmap_size)
 
 #endif /* CONFIG_PPC64 */
 
+/*
+ * Currently only consumed by page_table_check_pud_{set,clear}. Since clears
+ * and sets to page table entries at any level are done through
+ * page_table_check_pte_{set,clear}, provide stub implementation.
+ */
+#ifndef pud_pfn
+#define pud_pfn pud_pfn
+static inline int pud_pfn(pud_t pud)
+{
+	WARN_ONCE(1, "pud: platform does not use pud entries directly");
+	return 0;
+}
+#endif
+
+#ifndef pte_user_accessible_page
+#define pte_user_accessible_page pte_user_accessible_page
+static inline bool pte_user_accessible_page(pte_t pte, unsigned long addr)
+{
+	return pte_present(pte) && !is_kernel_addr(addr);
+}
+#endif
+
+#ifndef pmd_user_accessible_page
+#define pmd_user_accessible_page pmd_user_accessible_page
+static inline bool pmd_user_accessible_page(pmd_t pmd, unsigned long addr)
+{
+	WARN_ONCE(1, "pmd: platform does not use pmd entries directly");
+	return false;
+}
+#endif
+
+#ifndef pud_user_accessible_page
+#define pud_user_accessible_page pud_user_accessible_page
+static inline bool pud_user_accessible_page(pud_t pud, unsigned long addr)
+{
+	WARN_ONCE(1, "pud: platform does not use pud entries directly");
+	return false;
+}
+#endif
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* _ASM_POWERPC_PGTABLE_H */

arch/powerpc/kvm/book3s_64_mmu_radix.c

@@ -503,7 +503,7 @@ static void kvmppc_unmap_free_pmd(struct kvm *kvm, pmd_t *pmd, bool full,
 	for (im = 0; im < PTRS_PER_PMD; ++im, ++p) {
 		if (!pmd_present(*p))
 			continue;
-		if (pmd_is_leaf(*p)) {
+		if (pmd_leaf(*p)) {
 			if (full) {
 				pmd_clear(p);
 			} else {
@@ -532,7 +532,7 @@ static void kvmppc_unmap_free_pud(struct kvm *kvm, pud_t *pud,
 	for (iu = 0; iu < PTRS_PER_PUD; ++iu, ++p) {
 		if (!pud_present(*p))
 			continue;
-		if (pud_is_leaf(*p)) {
+		if (pud_leaf(*p)) {
 			pud_clear(p);
 		} else {
 			pmd_t *pmd;
@@ -635,12 +635,12 @@ int kvmppc_create_pte(struct kvm *kvm, pgd_t *pgtable, pte_t pte,
 		new_pud = pud_alloc_one(kvm->mm, gpa);
 
 	pmd = NULL;
-	if (pud && pud_present(*pud) && !pud_is_leaf(*pud))
+	if (pud && pud_present(*pud) && !pud_leaf(*pud))
 		pmd = pmd_offset(pud, gpa);
 	else if (level <= 1)
 		new_pmd = kvmppc_pmd_alloc();
 
-	if (level == 0 && !(pmd && pmd_present(*pmd) && !pmd_is_leaf(*pmd)))
+	if (level == 0 && !(pmd && pmd_present(*pmd) && !pmd_leaf(*pmd)))
 		new_ptep = kvmppc_pte_alloc();
 
 	/* Check if we might have been invalidated; let the guest retry if so */
@@ -658,7 +658,7 @@ int kvmppc_create_pte(struct kvm *kvm, pgd_t *pgtable, pte_t pte,
 		new_pud = NULL;
 	}
 	pud = pud_offset(p4d, gpa);
-	if (pud_is_leaf(*pud)) {
+	if (pud_leaf(*pud)) {
 		unsigned long hgpa = gpa & PUD_MASK;
 
 		/* Check if we raced and someone else has set the same thing */
@@ -709,7 +709,7 @@ int kvmppc_create_pte(struct kvm *kvm, pgd_t *pgtable, pte_t pte,
 		new_pmd = NULL;
 	}
 	pmd = pmd_offset(pud, gpa);
-	if (pmd_is_leaf(*pmd)) {
+	if (pmd_leaf(*pmd)) {
 		unsigned long lgpa = gpa & PMD_MASK;
 
 		/* Check if we raced and someone else has set the same thing */