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From:   Yu-cheng Yu <yu-cheng.yu@intel.com>
To:     x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
        Thomas Gleixner <tglx@linutronix.de>,
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        Vedvyas Shanbhogue <vedvyas.shanbhogue@intel.com>,
        Dave Martin <Dave.Martin@arm.com>,
        Weijiang Yang <weijiang.yang@intel.com>
Cc:     Yu-cheng Yu <yu-cheng.yu@intel.com>
Subject: [PATCH v10 15/26] mm: Fixup places that call pte_mkwrite() directly
Date:   Wed, 29 Apr 2020 15:07:21 -0700
Message-Id: <20200429220732.31602-16-yu-cheng.yu@intel.com>
In-Reply-To: <20200429220732.31602-1-yu-cheng.yu@intel.com>
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A shadow stack page is made writable by pte_mkwrite_shstk(), which sets
_PAGE_DIRTY_HW.  There are a few places that call pte_mkwrite() directly
and miss the maybe_mkwrite() fixup in the previous patch.  Fix them with
maybe_mkwrite():

- do_anonymous_page() and migrate_vma_insert_page() check VM_WRITE directly
  and call pte_mkwrite(), which is the same as maybe_mkwrite().  Change
  them to maybe_mkwrite().

- In do_numa_page(), if the numa entry 'was-writable', then pte_mkwrite()
  is called directly.  Fix it by doing maybe_mkwrite().

- In change_pte_range(), pte_mkwrite() is called directly.  Replace it with
  maybe_mkwrite().

Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
---
 mm/memory.c   | 5 ++---
 mm/migrate.c  | 3 +--
 mm/mprotect.c | 2 +-
 3 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/mm/memory.c b/mm/memory.c
index f703fe8c8346..b9002f644806 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3373,8 +3373,7 @@ static vm_fault_t do_anonymous_page(struct vm_fault *vmf)
 	__SetPageUptodate(page);
 
 	entry = mk_pte(page, vma->vm_page_prot);
-	if (vma->vm_flags & VM_WRITE)
-		entry = pte_mkwrite(pte_mkdirty(entry));
+	entry = maybe_mkwrite(pte_mkdirty(entry), vma);
 
 	vmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd, vmf->address,
 			&vmf->ptl);
@@ -4033,7 +4032,7 @@ static vm_fault_t do_numa_page(struct vm_fault *vmf)
 	pte = pte_modify(old_pte, vma->vm_page_prot);
 	pte = pte_mkyoung(pte);
 	if (was_writable)
-		pte = pte_mkwrite(pte);
+		pte = maybe_mkwrite(pte, vma);
 	ptep_modify_prot_commit(vma, vmf->address, vmf->pte, old_pte, pte);
 	update_mmu_cache(vma, vmf->address, vmf->pte);
 
diff --git a/mm/migrate.c b/mm/migrate.c
index 7160c1556f79..0fa59b1562c6 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -2805,8 +2805,7 @@ static void migrate_vma_insert_page(struct migrate_vma *migrate,
 		}
 	} else {
 		entry = mk_pte(page, vma->vm_page_prot);
-		if (vma->vm_flags & VM_WRITE)
-			entry = pte_mkwrite(pte_mkdirty(entry));
+		entry = maybe_mkwrite(pte_mkdirty(entry), vma);
 	}
 
 	ptep = pte_offset_map_lock(mm, pmdp, addr, &ptl);
diff --git a/mm/mprotect.c b/mm/mprotect.c
index 494192ca954b..02762af1057c 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -135,7 +135,7 @@ static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
 			if (dirty_accountable && pte_dirty(ptent) &&
 					(pte_soft_dirty(ptent) ||
 					 !(vma->vm_flags & VM_SOFTDIRTY))) {
-				ptent = pte_mkwrite(ptent);
+				ptent = maybe_mkwrite(ptent, vma);
 			}
 			ptep_modify_prot_commit(vma, addr, pte, oldpte, ptent);
 			pages++;
-- 
2.21.0