From: Yu-cheng Yu <yu-cheng.yu@intel.com>
To: x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>,
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 <arnd@arndb.de>,
Andy Lutomirski <luto@kernel.org>,
Balbir Singh <bsingharora@gmail.com>,
Borislav Petkov <bp@alien8.de>,
Cyrill Gorcunov <gorcunov@gmail.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
Eugene Syromiatnikov <esyr@redhat.com>,
Florian Weimer <fweimer@redhat.com>,
"H.J. Lu" <hjl.tools@gmail.com>, Jann Horn <jannh@google.com>,
Jonathan Corbet <corbet@lwn.net>,
Kees Cook <keescook@chromium.org>,
Mike Kravetz <mike.kravetz@oracle.com>,
Nadav Amit <nadav.amit@gmail.com>,
Oleg Nesterov <oleg@redhat.com>, Pavel Machek <pavel@ucw.cz>,
Peter Zijlstra <peterz@infradead.org>,
Randy Dunlap <rdunlap@infradead.org>,
"Ravi V. Shankar" <ravi.v.shankar@intel.com>,
Vedvyas Shanbhogue <vedvyas.shanbhogue@intel.com>,
Dave Martin <Dave.Martin@arm.com>,
Weijiang Yang <weijiang.yang@intel.com>,
Pengfei Xu <pengfei.xu@intel.com>,
Haitao Huang <haitao.huang@intel.com>
Cc: Yu-cheng Yu <yu-cheng.yu@intel.com>,
"Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Subject: [PATCH v24 11/30] x86/mm: Update pte_modify for _PAGE_COW
Date: Thu, 1 Apr 2021 15:10:45 -0700 [thread overview]
Message-ID: <20210401221104.31584-12-yu-cheng.yu@intel.com> (raw)
In-Reply-To: <20210401221104.31584-1-yu-cheng.yu@intel.com>
The read-only and Dirty PTE has been used to indicate copy-on-write pages.
However, newer x86 processors also regard a read-only and Dirty PTE as a
shadow stack page. In order to separate the two, the software-defined
_PAGE_COW is created to replace _PAGE_DIRTY for the copy-on-write case, and
pte_*() are updated.
Pte_modify() changes a PTE to 'newprot', but it doesn't use the pte_*().
Introduce fixup_dirty_pte(), which sets a dirty PTE, based on _PAGE_RW,
to either _PAGE_DIRTY or _PAGE_COW.
Apply the same changes to pmd_modify().
Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
arch/x86/include/asm/pgtable.h | 37 ++++++++++++++++++++++++++++++++++
1 file changed, 37 insertions(+)
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 9c056d5815de..e1739f590ca6 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -799,6 +799,23 @@ static inline pmd_t pmd_mkinvalid(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);
+
+ /*
+ * Fix up potential shadow stack page flags because the RO, Dirty
+ * PTE is special.
+ */
+ if (cpu_feature_enabled(X86_FEATURE_SHSTK)) {
+ if (pte_dirty(pte)) {
+ pte = pte_mkclean(pte);
+ pte = pte_mkdirty(pte);
+ }
+ }
+ return pte_val(pte);
+}
+
static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
{
pteval_t val = pte_val(pte), oldval = val;
@@ -809,16 +826,36 @@ 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);
+
+ /*
+ * Fix up potential shadow stack page flags because the RO, Dirty
+ * PMD is special.
+ */
+ if (cpu_feature_enabled(X86_FEATURE_SHSTK)) {
+ if (pmd_dirty(pmd)) {
+ pmd = pmd_mkclean(pmd);
+ pmd = pmd_mkdirty(pmd);
+ }
+ }
+ 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
next prev parent reply other threads:[~2021-04-01 22:11 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-01 22:10 [PATCH v24 00/30] Control-flow Enforcement: Shadow Stack Yu-cheng Yu
2021-04-01 22:10 ` [PATCH v24 01/30] Documentation/x86: Add CET description Yu-cheng Yu
2021-04-01 22:10 ` [PATCH v24 02/30] x86/cet/shstk: Add Kconfig option for Shadow Stack Yu-cheng Yu
2021-04-01 22:10 ` [PATCH v24 03/30] x86/cpufeatures: Add CET CPU feature flags for Control-flow Enforcement Technology (CET) Yu-cheng Yu
2021-04-01 22:10 ` [PATCH v24 04/30] x86/cpufeatures: Introduce X86_FEATURE_CET and setup functions Yu-cheng Yu
2021-04-09 10:12 ` Borislav Petkov
2021-04-09 15:52 ` Yu, Yu-cheng
2021-04-09 17:14 ` Borislav Petkov
2021-04-09 23:14 ` Yu, Yu-cheng
2021-04-10 9:29 ` Borislav Petkov
2021-04-01 22:10 ` [PATCH v24 05/30] x86/fpu/xstate: Introduce CET MSR and XSAVES supervisor states Yu-cheng Yu
2021-04-01 22:10 ` [PATCH v24 06/30] x86/cet: Add control-protection fault handler Yu-cheng Yu
2021-04-01 22:10 ` [PATCH v24 07/30] x86/mm: Remove _PAGE_DIRTY from kernel RO pages Yu-cheng Yu
2021-04-01 22:10 ` [PATCH v24 08/30] x86/mm: Move pmd_write(), pud_write() up in the file Yu-cheng Yu
2021-04-01 22:10 ` [PATCH v24 09/30] x86/mm: Introduce _PAGE_COW Yu-cheng Yu
2021-04-01 22:10 ` [PATCH v24 10/30] drm/i915/gvt: Change _PAGE_DIRTY to _PAGE_DIRTY_BITS Yu-cheng Yu
2021-04-01 22:10 ` Yu-cheng Yu [this message]
2021-04-01 22:10 ` [PATCH v24 12/30] x86/mm: Update ptep_set_wrprotect() and pmdp_set_wrprotect() for transition from _PAGE_DIRTY to _PAGE_COW Yu-cheng Yu
2021-04-09 15:07 ` Kirill A. Shutemov
2021-04-01 22:10 ` [PATCH v24 13/30] mm: Introduce VM_SHADOW_STACK for shadow stack memory Yu-cheng Yu
2021-04-09 15:10 ` Kirill A. Shutemov
2021-04-01 22:10 ` [PATCH v24 14/30] x86/mm: Shadow Stack page fault error checking Yu-cheng Yu
2021-04-09 15:12 ` Kirill A. Shutemov
2021-04-01 22:10 ` [PATCH v24 15/30] x86/mm: Update maybe_mkwrite() for shadow stack Yu-cheng Yu
2021-04-09 15:16 ` Kirill A. Shutemov
2021-04-01 22:10 ` [PATCH v24 16/30] mm: Fixup places that call pte_mkwrite() directly Yu-cheng Yu
2021-04-09 15:20 ` Kirill A. Shutemov
2021-04-01 22:10 ` [PATCH v24 17/30] mm: Add guard pages around a shadow stack Yu-cheng Yu
2021-04-09 15:22 ` Kirill A. Shutemov
2021-04-01 22:10 ` [PATCH v24 18/30] mm/mmap: Add shadow stack pages to memory accounting Yu-cheng Yu
2021-04-09 15:25 ` Kirill A. Shutemov
2021-04-01 22:10 ` [PATCH v24 19/30] mm: Update can_follow_write_pte() for shadow stack Yu-cheng Yu
2021-04-09 15:31 ` Kirill A. Shutemov
2021-04-01 22:10 ` [PATCH v24 20/30] mm/mprotect: Exclude shadow stack from preserve_write Yu-cheng Yu
2021-04-09 15:34 ` Kirill A. Shutemov
2021-04-01 22:10 ` [PATCH v24 21/30] mm: Re-introduce vm_flags to do_mmap() Yu-cheng Yu
2021-04-01 22:10 ` [PATCH v24 22/30] x86/cet/shstk: Add user-mode shadow stack support Yu-cheng Yu
2021-04-09 15:57 ` Kirill A. Shutemov
2021-04-09 23:47 ` Yu, Yu-cheng
2021-04-01 22:10 ` [PATCH v24 23/30] x86/cet/shstk: Handle thread shadow stack Yu-cheng Yu
2021-04-01 22:10 ` [PATCH v24 24/30] x86/cet/shstk: Introduce shadow stack token setup/verify routines Yu-cheng Yu
2021-04-06 22:49 ` Andy Lutomirski
2021-04-01 22:10 ` [PATCH v24 25/30] x86/cet/shstk: Handle signals for shadow stack Yu-cheng Yu
2021-04-06 22:50 ` Andy Lutomirski
2021-04-07 19:36 ` Yu, Yu-cheng
2021-04-01 22:11 ` [PATCH v24 26/30] ELF: Introduce arch_setup_elf_property() Yu-cheng Yu
2021-04-01 22:11 ` [PATCH v24 27/30] x86/cet/shstk: Add arch_prctl functions for shadow stack Yu-cheng Yu
2021-04-01 22:11 ` [PATCH v24 28/30] mm: Move arch_calc_vm_prot_bits() to arch/x86/include/asm/mman.h Yu-cheng Yu
2021-04-01 22:11 ` [PATCH v24 29/30] mm: Update arch_validate_flags() to include vma anonymous Yu-cheng Yu
2021-04-01 22:11 ` [PATCH v24 30/30] mm: Introduce PROT_SHSTK for shadow stack Yu-cheng Yu
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