[RFC PATCH 6/7] x86/mm: add x86_64 support for pte_ref

[Qi Zheng]

Add pte_ref hooks into routines that modify user PTE page tables,
and select ARCH_SUPPORTS_FREE_USER_PTE, so that the pte_ref code
can be compiled and worked on this architecture.

Signed-off-by: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
---
 arch/x86/Kconfig               | 1 +
 arch/x86/include/asm/pgtable.h | 4 ++++
 include/linux/pgtable.h        | 1 +
 3 files changed, 6 insertions(+)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 52a7f91527fe..50215b05723e 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -34,6 +34,7 @@ config X86_64
 	select SWIOTLB
 	select ARCH_HAS_ELFCORE_COMPAT
 	select ZONE_DMA32
+	select ARCH_SUPPORTS_FREE_USER_PTE
 
 config FORCE_DYNAMIC_FTRACE
 	def_bool y
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 44e2d6f1dbaa..cbfcfa497fb9 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -23,6 +23,7 @@
 #include <asm/coco.h>
 #include <asm-generic/pgtable_uffd.h>
 #include <linux/page_table_check.h>
+#include <linux/pte_ref.h>
 
 extern pgd_t early_top_pgt[PTRS_PER_PGD];
 bool __init __early_make_pgtable(unsigned long address, pmdval_t pmd);
@@ -1005,6 +1006,7 @@ static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
 			      pte_t *ptep, pte_t pte)
 {
 	page_table_check_pte_set(mm, addr, ptep, pte);
+	track_pte_set(mm, addr, ptep, pte);
 	set_pte(ptep, pte);
 }
 
@@ -1050,6 +1052,7 @@ static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
 {
 	pte_t pte = native_ptep_get_and_clear(ptep);
 	page_table_check_pte_clear(mm, addr, pte);
+	track_pte_clear(mm, addr, ptep, pte);
 	return pte;
 }
 
@@ -1066,6 +1069,7 @@ static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm,
 		 */
 		pte = native_local_ptep_get_and_clear(ptep);
 		page_table_check_pte_clear(mm, addr, pte);
+		track_pte_clear(mm, addr, ptep, pte);
 	} else {
 		pte = ptep_get_and_clear(mm, addr, ptep);
 	}
diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
index c4a6bda6e965..908636f48c95 100644
--- a/include/linux/pgtable.h
+++ b/include/linux/pgtable.h
@@ -276,6 +276,7 @@ static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
 	pte_t pte = *ptep;
 	pte_clear(mm, address, ptep);
 	page_table_check_pte_clear(mm, address, pte);
+	track_pte_clear(mm, address, ptep, pte);
 	return pte;
 }
 #endif
-- 
2.20.1