From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yu-cheng Yu Subject: [PATCH v10 10/26] x86/mm: Update pte_modify for _PAGE_COW Date: Wed, 29 Apr 2020 15:07:16 -0700 Message-ID: <20200429220732.31602-11-yu-cheng.yu@intel.com> References: <20200429220732.31602-1-yu-cheng.yu@intel.com> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20200429220732.31602-1-yu-cheng.yu@intel.com> Sender: linux-doc-owner@vger.kernel.org To: x86@kernel.org, "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-api@vger.kernel.org, Arnd Bergmann , Andy Lutomirski , Balbir Singh , Borislav Petkov , Cyrill Gorcunov , Dave Hansen , Eugene Syromiatnikov , Florian Weimer , "H.J. Lu" , Jann Horn , Jonathan Corbet , Kees Cook , Mike Kravetz , Nadav Amit Cc: Yu-cheng Yu List-Id: linux-arch.vger.kernel.org Pte_modify() changes a PTE to 'newprot'. It doesn't use the pte_*() helpers that a previous patch fixed up, so we need a new site. Introduce fixup_dirty_pte() to set the dirty bits based on _PAGE_RW, and apply the same changes to pmd_modify(). Signed-off-by: Yu-cheng Yu --- v10: - Change static_cpu_has() to cpu_feature_enabled(). - Replace _PAGE_CHG_MASK approach with fixup functions. arch/x86/include/asm/pgtable.h | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h index 5f89035d1e60..f4870cd040de 100644 --- a/arch/x86/include/asm/pgtable.h +++ b/arch/x86/include/asm/pgtable.h @@ -726,6 +726,21 @@ static inline pmd_t pmd_mknotpresent(pmd_t pmd) static inline u64 flip_protnone_guard(u64 oldval, u64 val, u64 mask); +static inline pteval_t fixup_dirty_pte(pteval_t pteval) +{ + pte_t pte = __pte(pteval); + + if (pte_dirty(pte)) { + pte = pte_mkclean(pte); + + if (pte_flags(pte) & _PAGE_RW) + pte = pte_set_flags(pte, _PAGE_DIRTY_HW); + else + pte = pte_set_flags(pte, _PAGE_COW); + } + return pte_val(pte); +} + static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) { pteval_t val = pte_val(pte), oldval = val; @@ -736,16 +751,34 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) */ val &= _PAGE_CHG_MASK; val |= check_pgprot(newprot) & ~_PAGE_CHG_MASK; + val = fixup_dirty_pte(val); val = flip_protnone_guard(oldval, val, PTE_PFN_MASK); return __pte(val); } +static inline int pmd_write(pmd_t pmd); +static inline pmdval_t fixup_dirty_pmd(pmdval_t pmdval) +{ + pmd_t pmd = __pmd(pmdval); + + if (pmd_dirty(pmd)) { + pmd = pmd_mkclean(pmd); + + if (pmd_flags(pmd) & _PAGE_RW) + pmd = pmd_set_flags(pmd, _PAGE_DIRTY_HW); + else + pmd = pmd_set_flags(pmd, _PAGE_COW); + } + return pmd_val(pmd); +} + static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot) { pmdval_t val = pmd_val(pmd), oldval = val; val &= _HPAGE_CHG_MASK; val |= check_pgprot(newprot) & ~_HPAGE_CHG_MASK; + val = fixup_dirty_pmd(val); val = flip_protnone_guard(oldval, val, PHYSICAL_PMD_PAGE_MASK); return __pmd(val); } -- 2.21.0 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Yu-cheng Yu Subject: [PATCH v10 10/26] x86/mm: Update pte_modify for _PAGE_COW Date: Wed, 29 Apr 2020 15:07:16 -0700 Message-ID: <20200429220732.31602-11-yu-cheng.yu@intel.com> In-Reply-To: <20200429220732.31602-1-yu-cheng.yu@intel.com> References: <20200429220732.31602-1-yu-cheng.yu@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org To: x86@kernel.org, "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-api@vger.kernel.org, Arnd Bergmann , Andy Lutomirski , Balbir Singh , Borislav Petkov , Cyrill Gorcunov , Dave Hansen , Eugene Syromiatnikov , Florian Weimer , "H.J. Lu" , Jann Horn , Jonathan Corbet , Kees Cook , Mike Kravetz , Nadav Amit , Oleg Nesterov , Pavel Machek , Peter Zijlstra , Randy Dunlap , "Ravi V. Shankar" , Vedvyas Shanbhogue , Dave Martin , Weijiang Yang Cc: Yu-cheng Yu List-ID: Message-ID: <20200429220716.7-rilXvAmsfXh30jDsqTtPmbMDFALBPxaS78gFZ6Jgg@z> Pte_modify() changes a PTE to 'newprot'. It doesn't use the pte_*() helpers that a previous patch fixed up, so we need a new site. Introduce fixup_dirty_pte() to set the dirty bits based on _PAGE_RW, and apply the same changes to pmd_modify(). Signed-off-by: Yu-cheng Yu --- v10: - Change static_cpu_has() to cpu_feature_enabled(). - Replace _PAGE_CHG_MASK approach with fixup functions. arch/x86/include/asm/pgtable.h | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtabl= e.h index 5f89035d1e60..f4870cd040de 100644 --- a/arch/x86/include/asm/pgtable.h +++ b/arch/x86/include/asm/pgtable.h @@ -726,6 +726,21 @@ static inline pmd_t pmd_mknotpresent(pmd_t pmd) =20 static inline u64 flip_protnone_guard(u64 oldval, u64 val, u64 mask); =20 +static inline pteval_t fixup_dirty_pte(pteval_t pteval) +{ + pte_t pte =3D __pte(pteval); + + if (pte_dirty(pte)) { + pte =3D pte_mkclean(pte); + + if (pte_flags(pte) & _PAGE_RW) + pte =3D pte_set_flags(pte, _PAGE_DIRTY_HW); + else + pte =3D pte_set_flags(pte, _PAGE_COW); + } + return pte_val(pte); +} + static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) { pteval_t val =3D pte_val(pte), oldval =3D val; @@ -736,16 +751,34 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t = newprot) */ val &=3D _PAGE_CHG_MASK; val |=3D check_pgprot(newprot) & ~_PAGE_CHG_MASK; + val =3D fixup_dirty_pte(val); val =3D flip_protnone_guard(oldval, val, PTE_PFN_MASK); return __pte(val); } =20 +static inline int pmd_write(pmd_t pmd); +static inline pmdval_t fixup_dirty_pmd(pmdval_t pmdval) +{ + pmd_t pmd =3D __pmd(pmdval); + + if (pmd_dirty(pmd)) { + pmd =3D pmd_mkclean(pmd); + + if (pmd_flags(pmd) & _PAGE_RW) + pmd =3D pmd_set_flags(pmd, _PAGE_DIRTY_HW); + else + pmd =3D pmd_set_flags(pmd, _PAGE_COW); + } + return pmd_val(pmd); +} + static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot) { pmdval_t val =3D pmd_val(pmd), oldval =3D val; =20 val &=3D _HPAGE_CHG_MASK; val |=3D check_pgprot(newprot) & ~_HPAGE_CHG_MASK; + val =3D fixup_dirty_pmd(val); val =3D flip_protnone_guard(oldval, val, PHYSICAL_PMD_PAGE_MASK); return __pmd(val); } --=20 2.21.0