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>
Subject: [PATCH v23 19/28] mm: Update can_follow_write_pte() for shadow stack
Date: Tue, 16 Mar 2021 08:10:45 -0700 [thread overview]
Message-ID: <20210316151054.5405-20-yu-cheng.yu@intel.com> (raw)
In-Reply-To: <20210316151054.5405-1-yu-cheng.yu@intel.com>
Can_follow_write_pte() ensures a read-only page is COWed by checking the
FOLL_COW flag, and uses pte_dirty() to validate the flag is still valid.
Like a writable data page, a shadow stack page is writable, and becomes
read-only during copy-on-write, but it is always dirty. Thus, in the
can_follow_write_pte() check, it belongs to the writable page case and
should be excluded from the read-only page pte_dirty() check. Apply
the same changes to can_follow_write_pmd().
Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
---
mm/gup.c | 8 +++++---
mm/huge_memory.c | 8 +++++---
2 files changed, 10 insertions(+), 6 deletions(-)
diff --git a/mm/gup.c b/mm/gup.c
index e40579624f10..4c6aa93b3c00 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -356,10 +356,12 @@ static int follow_pfn_pte(struct vm_area_struct *vma, unsigned long address,
* FOLL_FORCE can write to even unwritable pte's, but only
* after we've gone through a COW cycle and they are dirty.
*/
-static inline bool can_follow_write_pte(pte_t pte, unsigned int flags)
+static inline bool can_follow_write_pte(pte_t pte, unsigned int flags,
+ struct vm_area_struct *vma)
{
return pte_write(pte) ||
- ((flags & FOLL_FORCE) && (flags & FOLL_COW) && pte_dirty(pte));
+ ((flags & FOLL_FORCE) && (flags & FOLL_COW) && pte_dirty(pte) &&
+ !arch_shadow_stack_mapping(vma->vm_flags));
}
static struct page *follow_page_pte(struct vm_area_struct *vma,
@@ -402,7 +404,7 @@ static struct page *follow_page_pte(struct vm_area_struct *vma,
}
if ((flags & FOLL_NUMA) && pte_protnone(pte))
goto no_page;
- if ((flags & FOLL_WRITE) && !can_follow_write_pte(pte, flags)) {
+ if ((flags & FOLL_WRITE) && !can_follow_write_pte(pte, flags, vma)) {
pte_unmap_unlock(ptep, ptl);
return NULL;
}
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index e79c1220a349..3ad7d521a7b5 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1338,10 +1338,12 @@ vm_fault_t do_huge_pmd_wp_page(struct vm_fault *vmf, pmd_t orig_pmd)
* FOLL_FORCE can write to even unwritable pmd's, but only
* after we've gone through a COW cycle and they are dirty.
*/
-static inline bool can_follow_write_pmd(pmd_t pmd, unsigned int flags)
+static inline bool can_follow_write_pmd(pmd_t pmd, unsigned int flags,
+ struct vm_area_struct *vma)
{
return pmd_write(pmd) ||
- ((flags & FOLL_FORCE) && (flags & FOLL_COW) && pmd_dirty(pmd));
+ ((flags & FOLL_FORCE) && (flags & FOLL_COW) && pmd_dirty(pmd) &&
+ !arch_shadow_stack_mapping(vma->vm_flags));
}
struct page *follow_trans_huge_pmd(struct vm_area_struct *vma,
@@ -1354,7 +1356,7 @@ struct page *follow_trans_huge_pmd(struct vm_area_struct *vma,
assert_spin_locked(pmd_lockptr(mm, pmd));
- if (flags & FOLL_WRITE && !can_follow_write_pmd(*pmd, flags))
+ if (flags & FOLL_WRITE && !can_follow_write_pmd(*pmd, flags, vma))
goto out;
/* Avoid dumping huge zero page */
--
2.21.0
next prev parent reply other threads:[~2021-03-16 15:13 UTC|newest]
Thread overview: 66+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-16 15:10 [PATCH v23 00/28] Control-flow Enforcement: Shadow Stack Yu-cheng Yu
2021-03-16 15:10 ` [PATCH v23 01/28] Documentation/x86: Add CET description Yu-cheng Yu
2021-03-16 15:10 ` [PATCH v23 02/28] x86/cet/shstk: Add Kconfig option for user-mode control-flow protection Yu-cheng Yu
2021-03-16 15:10 ` [PATCH v23 03/28] x86/cpufeatures: Add CET CPU feature flags for Control-flow Enforcement Technology (CET) Yu-cheng Yu
2021-03-16 15:10 ` [PATCH v23 04/28] x86/cpufeatures: Introduce X86_FEATURE_CET and setup functions Yu-cheng Yu
2021-03-16 15:10 ` [PATCH v23 05/28] x86/fpu/xstate: Introduce CET MSR and XSAVES supervisor states Yu-cheng Yu
2021-03-16 15:10 ` [PATCH v23 06/28] x86/cet: Add control-protection fault handler Yu-cheng Yu
2021-03-16 15:10 ` [PATCH v23 07/28] x86/mm: Remove _PAGE_DIRTY from kernel RO pages Yu-cheng Yu
2021-03-22 9:13 ` Kirill A. Shutemov
2021-03-22 14:52 ` Yu, Yu-cheng
2021-03-16 15:10 ` [PATCH v23 08/28] x86/mm: Move pmd_write(), pud_write() up in the file Yu-cheng Yu
2021-03-22 11:28 ` Kirill A. Shutemov
2021-03-16 15:10 ` [PATCH v23 09/28] x86/mm: Introduce _PAGE_COW Yu-cheng Yu
2021-03-22 11:29 ` Kirill A. Shutemov
2021-03-16 15:10 ` [PATCH v23 10/28] drm/i915/gvt: Change _PAGE_DIRTY to _PAGE_DIRTY_BITS Yu-cheng Yu
2021-03-22 11:30 ` Kirill A. Shutemov
2021-03-16 15:10 ` [PATCH v23 11/28] x86/mm: Update pte_modify for _PAGE_COW Yu-cheng Yu
2021-03-22 11:31 ` Kirill A. Shutemov
2021-03-16 15:10 ` [PATCH v23 12/28] x86/mm: Update ptep_set_wrprotect() and pmdp_set_wrprotect() for transition from _PAGE_DIRTY to _PAGE_COW Yu-cheng Yu
2021-03-22 10:15 ` Kirill A. Shutemov
2021-03-22 10:46 ` Peter Zijlstra
2021-03-22 11:38 ` Kirill A. Shutemov
2021-03-16 15:10 ` [PATCH v23 13/28] mm: Introduce VM_SHSTK for shadow stack memory Yu-cheng Yu
2021-03-22 11:33 ` Kirill A. Shutemov
2021-03-16 15:10 ` [PATCH v23 14/28] x86/mm: Shadow Stack page fault error checking Yu-cheng Yu
2021-03-22 10:38 ` Kirill A. Shutemov
2021-03-22 17:27 ` Yu, Yu-cheng
2021-03-16 15:10 ` [PATCH v23 15/28] x86/mm: Update maybe_mkwrite() for shadow stack Yu-cheng Yu
2021-03-17 15:56 ` Borislav Petkov
2021-03-22 10:46 ` Kirill A. Shutemov
2021-03-16 15:10 ` [PATCH v23 16/28] mm: Fixup places that call pte_mkwrite() directly Yu-cheng Yu
2021-03-18 9:47 ` Borislav Petkov
2021-03-18 11:16 ` Borislav Petkov
2021-03-16 15:10 ` [PATCH v23 17/28] mm: Add guard pages around a shadow stack Yu-cheng Yu
2021-03-22 10:55 ` Kirill A. Shutemov
2021-03-16 15:10 ` [PATCH v23 18/28] mm/mmap: Add shadow stack pages to memory accounting Yu-cheng Yu
2021-03-22 10:57 ` Kirill A. Shutemov
2021-03-26 15:46 ` Yu, Yu-cheng
2021-03-29 10:10 ` Kirill A. Shutemov
2021-03-16 15:10 ` Yu-cheng Yu [this message]
2021-03-16 15:10 ` [PATCH v23 20/28] mm/mprotect: Exclude shadow stack from preserve_write Yu-cheng Yu
2021-03-16 15:10 ` [PATCH v23 21/28] mm: Re-introduce vm_flags to do_mmap() Yu-cheng Yu
2021-03-18 11:42 ` Borislav Petkov
2021-03-18 15:59 ` Yu, Yu-cheng
2021-03-18 16:13 ` Borislav Petkov
2021-03-16 15:10 ` [PATCH v23 22/28] x86/cet/shstk: User-mode shadow stack support Yu-cheng Yu
2021-03-18 12:32 ` Borislav Petkov
2021-03-18 19:05 ` Yu, Yu-cheng
2021-03-19 9:28 ` Borislav Petkov
2021-03-19 15:15 ` Yu, Yu-cheng
2021-03-16 15:10 ` [PATCH v23 23/28] x86/cet/shstk: Handle signals for shadow stack Yu-cheng Yu
2021-03-19 12:51 ` Borislav Petkov
2021-03-16 15:10 ` [PATCH v23 24/28] ELF: Introduce arch_setup_elf_property() Yu-cheng Yu
2021-03-16 15:10 ` [PATCH v23 25/28] x86/cet/shstk: Handle thread shadow stack Yu-cheng Yu
2021-03-16 15:10 ` [PATCH v23 26/28] x86/cet/shstk: Add arch_prctl functions for " Yu-cheng Yu
2021-03-16 15:10 ` [PATCH v23 27/28] mm: Move arch_calc_vm_prot_bits() to arch/x86/include/asm/mman.h Yu-cheng Yu
2021-03-16 15:10 ` [PATCH v23 28/28] mm: Introduce PROT_SHSTK for shadow stack Yu-cheng Yu
2021-03-22 11:27 ` Kirill A. Shutemov
2021-03-16 21:15 ` [PATCH v23 00/28] Control-flow Enforcement: Shadow Stack Peter Zijlstra
2021-03-16 21:34 ` Yu, Yu-cheng
2021-03-17 9:18 ` Ingo Molnar
2021-03-17 10:14 ` Peter Zijlstra
2021-03-19 16:24 ` Yu, Yu-cheng
2021-03-19 21:43 ` Yu, Yu-cheng
2021-03-23 20:49 ` Peter Zijlstra
2021-03-23 21:03 ` Yu, Yu-cheng
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