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Donenfeld" , Dinglan Peng , Pedro Fonseca , Jim Huang , Huichun Feng , Chih-En Lin Subject: [PATCH v3 06/14] mm/ksm: Break COW PTE before modify shared PTE Date: Tue, 20 Dec 2022 15:27:35 +0800 Message-Id: <20221220072743.3039060-7-shiyn.lin@gmail.com> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20221220072743.3039060-1-shiyn.lin@gmail.com> References: <20221220072743.3039060-1-shiyn.lin@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Break COW PTE before merge the page that reside in COW-ed PTE. Signed-off-by: Chih-En Lin --- mm/ksm.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/mm/ksm.c b/mm/ksm.c index c19fcca9bc03d..896a14c44a858 100644 --- a/mm/ksm.c +++ b/mm/ksm.c @@ -1017,7 +1017,7 @@ static int write_protect_page(struct vm_area_struct *= vma, struct page *page, pte_t *orig_pte) { struct mm_struct *mm =3D vma->vm_mm; - DEFINE_PAGE_VMA_WALK(pvmw, page, vma, 0, 0); + DEFINE_PAGE_VMA_WALK(pvmw, page, vma, 0, PVMW_BREAK_COW_PTE); int swapped; int err =3D -EFAULT; struct mmu_notifier_range range; @@ -1136,6 +1136,8 @@ static int replace_page(struct vm_area_struct *vma, s= truct page *page, barrier(); if (!pmd_present(pmde) || pmd_trans_huge(pmde)) goto out; + if (break_cow_pte(vma, pmd, addr) < 0) + goto out; =20 mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, mm, addr, addr + PAGE_SIZE); --=20 2.37.3