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@amacapital.net>,
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>
Cc: Yu-cheng Yu <yu-cheng.yu@intel.com>
Subject: [PATCH v7 15/27] mm: Handle shadow stack page fault
Date: Thu, 6 Jun 2019 13:06:34 -0700 [thread overview]
Message-ID: <20190606200646.3951-16-yu-cheng.yu@intel.com> (raw)
In-Reply-To: <20190606200646.3951-1-yu-cheng.yu@intel.com>
When a task does fork(), its shadow stack (SHSTK) must be duplicated
for the child. This patch implements a flow similar to copy-on-write
of an anonymous page, but for SHSTK.
A SHSTK PTE must be RO and dirty. This dirty bit requirement is used
to effect the copying. In copy_one_pte(), clear the dirty bit from a
SHSTK PTE to cause a page fault upon the next SHSTK access. At that
time, fix the PTE and copy/re-use the page.
Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
---
arch/x86/mm/pgtable.c | 15 +++++++++++++++
include/asm-generic/pgtable.h | 8 ++++++++
mm/memory.c | 7 ++++++-
3 files changed, 29 insertions(+), 1 deletion(-)
diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c
index 1f67b1e15bf6..c2d754a780b3 100644
--- a/arch/x86/mm/pgtable.c
+++ b/arch/x86/mm/pgtable.c
@@ -891,3 +891,18 @@ int pmd_free_pte_page(pmd_t *pmd, unsigned long addr)
#endif /* CONFIG_X86_64 */
#endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */
+
+#ifdef CONFIG_X86_INTEL_SHADOW_STACK_USER
+inline pte_t pte_set_vma_features(pte_t pte, struct vm_area_struct *vma)
+{
+ if (vma->vm_flags & VM_SHSTK)
+ return pte_mkdirty_shstk(pte);
+ else
+ return pte;
+}
+
+inline bool arch_copy_pte_mapping(vm_flags_t vm_flags)
+{
+ return (vm_flags & VM_SHSTK);
+}
+#endif /* CONFIG_X86_INTEL_SHADOW_STACK_USER */
diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h
index 75d9d68a6de7..ffcc0be7cadc 100644
--- a/include/asm-generic/pgtable.h
+++ b/include/asm-generic/pgtable.h
@@ -1188,4 +1188,12 @@ static inline bool arch_has_pfn_modify_check(void)
#define mm_pmd_folded(mm) __is_defined(__PAGETABLE_PMD_FOLDED)
#endif
+#ifndef CONFIG_ARCH_HAS_SHSTK
+#define pte_set_vma_features(pte, vma) pte
+#define arch_copy_pte_mapping(vma_flags) false
+#else
+pte_t pte_set_vma_features(pte_t pte, struct vm_area_struct *vma);
+bool arch_copy_pte_mapping(vm_flags_t vm_flags);
+#endif
+
#endif /* _ASM_GENERIC_PGTABLE_H */
diff --git a/mm/memory.c b/mm/memory.c
index ddf20bd0c317..51c97294f00f 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -777,7 +777,8 @@ copy_one_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm,
* If it's a COW mapping, write protect it both
* in the parent and the child
*/
- if (is_cow_mapping(vm_flags) && pte_write(pte)) {
+ if ((is_cow_mapping(vm_flags) && pte_write(pte)) ||
+ arch_copy_pte_mapping(vm_flags)) {
ptep_set_wrprotect(src_mm, addr, src_pte);
pte = pte_wrprotect(pte);
}
@@ -2312,6 +2313,7 @@ static inline void wp_page_reuse(struct vm_fault *vmf)
flush_cache_page(vma, vmf->address, pte_pfn(vmf->orig_pte));
entry = pte_mkyoung(vmf->orig_pte);
entry = maybe_mkwrite(pte_mkdirty(entry), vma);
+ entry = pte_set_vma_features(entry, vma);
if (ptep_set_access_flags(vma, vmf->address, vmf->pte, entry, 1))
update_mmu_cache(vma, vmf->address, vmf->pte);
pte_unmap_unlock(vmf->pte, vmf->ptl);
@@ -2387,6 +2389,7 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf)
flush_cache_page(vma, vmf->address, pte_pfn(vmf->orig_pte));
entry = mk_pte(new_page, vma->vm_page_prot);
entry = maybe_mkwrite(pte_mkdirty(entry), vma);
+ entry = pte_set_vma_features(entry, vma);
/*
* Clear the pte entry and flush it first, before updating the
* pte with the new entry. This will avoid a race condition
@@ -2910,6 +2913,7 @@ vm_fault_t do_swap_page(struct vm_fault *vmf)
pte = mk_pte(page, vma->vm_page_prot);
if ((vmf->flags & FAULT_FLAG_WRITE) && reuse_swap_page(page, NULL)) {
pte = maybe_mkwrite(pte_mkdirty(pte), vma);
+ pte = pte_set_vma_features(pte, vma);
vmf->flags &= ~FAULT_FLAG_WRITE;
ret |= VM_FAULT_WRITE;
exclusive = RMAP_EXCLUSIVE;
@@ -3052,6 +3056,7 @@ static vm_fault_t do_anonymous_page(struct vm_fault *vmf)
entry = mk_pte(page, vma->vm_page_prot);
if (vma->vm_flags & VM_WRITE)
entry = pte_mkwrite(pte_mkdirty(entry));
+ entry = pte_set_vma_features(entry, vma);
vmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd, vmf->address,
&vmf->ptl);
--
2.17.1
next prev parent reply other threads:[~2019-06-06 20:15 UTC|newest]
Thread overview: 70+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-06 20:06 [PATCH v7 00/27] Control-flow Enforcement: Shadow Stack Yu-cheng Yu
2019-06-06 20:06 ` [PATCH v7 01/27] Documentation/x86: Add CET description Yu-cheng Yu
2019-06-06 20:06 ` [PATCH v7 02/27] x86/cpufeatures: Add CET CPU feature flags for Control-flow Enforcement Technology (CET) Yu-cheng Yu
2019-06-06 20:06 ` [PATCH v7 03/27] x86/fpu/xstate: Change names to separate XSAVES system and user states Yu-cheng Yu
2019-06-06 20:06 ` [PATCH v7 04/27] x86/fpu/xstate: Introduce XSAVES system states Yu-cheng Yu
2019-06-06 21:18 ` Dave Hansen
2019-06-06 22:04 ` Andy Lutomirski
2019-06-06 22:08 ` Dave Hansen
2019-06-06 22:10 ` Yu-cheng Yu
2019-06-07 1:54 ` Andy Lutomirski
2019-06-06 20:06 ` [PATCH v7 05/27] x86/fpu/xstate: Add XSAVES system states for shadow stack Yu-cheng Yu
2019-06-07 7:07 ` Peter Zijlstra
2019-06-07 16:14 ` Yu-cheng Yu
2019-06-06 20:06 ` [PATCH v7 06/27] x86/cet: Add control protection exception handler Yu-cheng Yu
2019-06-06 20:06 ` [PATCH v7 07/27] x86/cet/shstk: Add Kconfig option for user-mode shadow stack Yu-cheng Yu
2019-06-06 20:06 ` [PATCH v7 08/27] mm: Introduce VM_SHSTK for shadow stack memory Yu-cheng Yu
2019-06-06 20:06 ` [PATCH v7 09/27] mm/mmap: Prevent Shadow Stack VMA merges Yu-cheng Yu
2019-06-06 20:06 ` [PATCH v7 10/27] x86/mm: Change _PAGE_DIRTY to _PAGE_DIRTY_HW Yu-cheng Yu
2019-06-06 20:06 ` [PATCH v7 11/27] x86/mm: Introduce _PAGE_DIRTY_SW Yu-cheng Yu
2019-06-06 20:06 ` [PATCH v7 12/27] drm/i915/gvt: Update _PAGE_DIRTY to _PAGE_DIRTY_BITS Yu-cheng Yu
2019-06-06 20:06 ` [PATCH v7 13/27] x86/mm: Modify ptep_set_wrprotect and pmdp_set_wrprotect for _PAGE_DIRTY_SW Yu-cheng Yu
2019-06-06 20:06 ` [PATCH v7 14/27] x86/mm: Shadow stack page fault error checking Yu-cheng Yu
2019-06-06 20:06 ` Yu-cheng Yu [this message]
2019-06-07 7:30 ` [PATCH v7 15/27] mm: Handle shadow stack page fault Peter Zijlstra
2019-06-06 20:06 ` [PATCH v7 16/27] mm: Handle THP/HugeTLB " Yu-cheng Yu
2019-06-06 20:06 ` [PATCH v7 17/27] mm: Update can_follow_write_pte/pmd for shadow stack Yu-cheng Yu
2019-06-06 20:06 ` [PATCH v7 18/27] mm: Introduce do_mmap_locked() Yu-cheng Yu
2019-06-07 7:43 ` Peter Zijlstra
2019-06-07 7:47 ` Peter Zijlstra
2019-06-07 16:16 ` Yu-cheng Yu
2019-06-06 20:06 ` [PATCH v7 19/27] x86/cet/shstk: User-mode shadow stack support Yu-cheng Yu
2019-06-06 20:06 ` [PATCH v7 20/27] x86/cet/shstk: Introduce WRUSS instruction Yu-cheng Yu
2019-06-06 20:06 ` [PATCH v7 21/27] x86/cet/shstk: Handle signals for shadow stack Yu-cheng Yu
2019-06-06 20:06 ` [PATCH v7 22/27] binfmt_elf: Extract .note.gnu.property from an ELF file Yu-cheng Yu
2019-06-07 7:58 ` Peter Zijlstra
2019-06-07 16:17 ` Yu-cheng Yu
2019-06-07 18:01 ` Dave Martin
2019-06-10 16:29 ` Yu-cheng Yu
2019-06-10 16:57 ` Dave Martin
2019-06-10 17:24 ` Florian Weimer
2019-06-11 11:41 ` Dave Martin
2019-06-11 19:31 ` Yu-cheng Yu
2019-06-12 9:32 ` Dave Martin
2019-06-12 19:04 ` Yu-cheng Yu
2019-06-13 13:26 ` Dave Martin
2019-06-17 11:08 ` Florian Weimer
2019-06-17 12:20 ` Thomas Gleixner
2019-06-18 9:12 ` Dave Martin
2019-06-18 12:41 ` Peter Zijlstra
2019-06-18 12:47 ` Florian Weimer
2019-06-18 12:55 ` Peter Zijlstra
2019-06-18 13:32 ` Dave Martin
2019-06-18 14:58 ` Yu-cheng Yu
2019-06-18 15:49 ` Florian Weimer
2019-06-18 15:53 ` Yu-cheng Yu
2019-06-18 16:05 ` Florian Weimer
2019-06-18 16:00 ` Yu-cheng Yu
2019-06-18 16:20 ` Dave Martin
2019-06-18 16:25 ` Florian Weimer
2019-06-18 16:50 ` Dave Martin
2019-06-06 20:06 ` [PATCH v7 23/27] x86/cet/shstk: ELF header parsing of Shadow Stack Yu-cheng Yu
2019-06-07 7:54 ` Peter Zijlstra
2019-06-06 20:06 ` [PATCH v7 24/27] x86/cet/shstk: Handle thread shadow stack Yu-cheng Yu
2019-06-06 20:06 ` [PATCH v7 25/27] mm/mmap: Add Shadow stack pages to memory accounting Yu-cheng Yu
2019-06-11 17:55 ` Dave Hansen
2019-06-11 19:22 ` Yu-cheng Yu
2019-06-06 20:06 ` [PATCH v7 26/27] x86/cet/shstk: Add arch_prctl functions for Shadow Stack Yu-cheng Yu
2019-06-06 20:06 ` [PATCH v7 27/27] x86/cet/shstk: Add Shadow Stack instructions to opcode map Yu-cheng Yu
2019-11-01 14:03 ` Adrian Hunter
2019-11-01 14:17 ` Yu-cheng Yu
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