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>, Cyrill Gorcunov <gorcunov@gmail.com>, Dave Hansen <dave.hansen@linux.intel.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> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Subject: [RFC PATCH v4 13/27] x86/mm: Shadow stack page fault error checking Date: Fri, 21 Sep 2018 08:03:37 -0700 [thread overview] Message-ID: <20180921150351.20898-14-yu-cheng.yu@intel.com> (raw) In-Reply-To: <20180921150351.20898-1-yu-cheng.yu@intel.com> If a page fault is triggered by a shadow stack access (e.g. call/ret) or shadow stack management instructions (e.g. wrussq), then bit[6] of the page fault error code is set. In access_error(), we check if a shadow stack page fault is within a shadow stack memory area. Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> --- arch/x86/include/asm/traps.h | 2 ++ arch/x86/mm/fault.c | 18 ++++++++++++++++++ 2 files changed, 20 insertions(+) diff --git a/arch/x86/include/asm/traps.h b/arch/x86/include/asm/traps.h index 5196050ff3d5..58ea2f5722e9 100644 --- a/arch/x86/include/asm/traps.h +++ b/arch/x86/include/asm/traps.h @@ -157,6 +157,7 @@ enum { * bit 3 == 1: use of reserved bit detected * bit 4 == 1: fault was an instruction fetch * bit 5 == 1: protection keys block access + * bit 6 == 1: shadow stack access fault */ enum x86_pf_error_code { X86_PF_PROT = 1 << 0, @@ -165,5 +166,6 @@ enum x86_pf_error_code { X86_PF_RSVD = 1 << 3, X86_PF_INSTR = 1 << 4, X86_PF_PK = 1 << 5, + X86_PF_SHSTK = 1 << 6, }; #endif /* _ASM_X86_TRAPS_H */ diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 47bebfe6efa7..7c3877a982f4 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -1162,6 +1162,17 @@ access_error(unsigned long error_code, struct vm_area_struct *vma) (error_code & X86_PF_INSTR), foreign)) return 1; + /* + * Verify X86_PF_SHSTK is within a shadow stack VMA. + * It is always an error if there is a shadow stack + * fault outside a shadow stack VMA. + */ + if (error_code & X86_PF_SHSTK) { + if (!(vma->vm_flags & VM_SHSTK)) + return 1; + return 0; + } + if (error_code & X86_PF_WRITE) { /* write, present and write, not present: */ if (unlikely(!(vma->vm_flags & VM_WRITE))) @@ -1300,6 +1311,13 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code, perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address); + /* + * If the fault is caused by a shadow stack access, + * i.e. CALL/RET/SAVEPREVSSP/RSTORSSP, then set + * FAULT_FLAG_WRITE to effect copy-on-write. + */ + if (error_code & X86_PF_SHSTK) + flags |= FAULT_FLAG_WRITE; if (error_code & X86_PF_WRITE) flags |= FAULT_FLAG_WRITE; if (error_code & X86_PF_INSTR) -- 2.17.1
WARNING: multiple messages have this Message-ID (diff)
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>, Cyrill Gorcunov <gorcunov@gmail.com>, Dave Hansen <dave.hansen@linux.intel.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 Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Subject: [RFC PATCH v4 13/27] x86/mm: Shadow stack page fault error checking Date: Fri, 21 Sep 2018 08:03:37 -0700 [thread overview] Message-ID: <20180921150351.20898-14-yu-cheng.yu@intel.com> (raw) In-Reply-To: <20180921150351.20898-1-yu-cheng.yu@intel.com> If a page fault is triggered by a shadow stack access (e.g. call/ret) or shadow stack management instructions (e.g. wrussq), then bit[6] of the page fault error code is set. In access_error(), we check if a shadow stack page fault is within a shadow stack memory area. Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> --- arch/x86/include/asm/traps.h | 2 ++ arch/x86/mm/fault.c | 18 ++++++++++++++++++ 2 files changed, 20 insertions(+) diff --git a/arch/x86/include/asm/traps.h b/arch/x86/include/asm/traps.h index 5196050ff3d5..58ea2f5722e9 100644 --- a/arch/x86/include/asm/traps.h +++ b/arch/x86/include/asm/traps.h @@ -157,6 +157,7 @@ enum { * bit 3 == 1: use of reserved bit detected * bit 4 == 1: fault was an instruction fetch * bit 5 == 1: protection keys block access + * bit 6 == 1: shadow stack access fault */ enum x86_pf_error_code { X86_PF_PROT = 1 << 0, @@ -165,5 +166,6 @@ enum x86_pf_error_code { X86_PF_RSVD = 1 << 3, X86_PF_INSTR = 1 << 4, X86_PF_PK = 1 << 5, + X86_PF_SHSTK = 1 << 6, }; #endif /* _ASM_X86_TRAPS_H */ diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 47bebfe6efa7..7c3877a982f4 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -1162,6 +1162,17 @@ access_error(unsigned long error_code, struct vm_area_struct *vma) (error_code & X86_PF_INSTR), foreign)) return 1; + /* + * Verify X86_PF_SHSTK is within a shadow stack VMA. + * It is always an error if there is a shadow stack + * fault outside a shadow stack VMA. + */ + if (error_code & X86_PF_SHSTK) { + if (!(vma->vm_flags & VM_SHSTK)) + return 1; + return 0; + } + if (error_code & X86_PF_WRITE) { /* write, present and write, not present: */ if (unlikely(!(vma->vm_flags & VM_WRITE))) @@ -1300,6 +1311,13 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code, perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address); + /* + * If the fault is caused by a shadow stack access, + * i.e. CALL/RET/SAVEPREVSSP/RSTORSSP, then set + * FAULT_FLAG_WRITE to effect copy-on-write. + */ + if (error_code & X86_PF_SHSTK) + flags |= FAULT_FLAG_WRITE; if (error_code & X86_PF_WRITE) flags |= FAULT_FLAG_WRITE; if (error_code & X86_PF_INSTR) -- 2.17.1
next prev parent reply other threads:[~2018-09-21 15:09 UTC|newest] Thread overview: 145+ messages / expand[flat|nested] mbox.gz Atom feed top 2018-09-21 15:03 [RFC PATCH v4 00/27] Control Flow Enforcement: Shadow Stack Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-09-21 15:03 ` [RFC PATCH v4 01/27] x86/cpufeatures: Add CPUIDs for Control-flow Enforcement Technology (CET) Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-09-25 16:27 ` Peter Zijlstra 2018-09-25 16:27 ` Peter Zijlstra 2018-09-25 16:29 ` Yu-cheng Yu 2018-09-25 16:29 ` Yu-cheng Yu 2018-09-28 16:51 ` Borislav Petkov 2018-09-28 16:51 ` Borislav Petkov 2018-09-28 16:56 ` Yu-cheng Yu 2018-09-28 16:56 ` Yu-cheng Yu 2018-09-21 15:03 ` [RFC PATCH v4 02/27] x86/fpu/xstate: Change some names to separate XSAVES system and user states Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-09-25 16:37 ` Peter Zijlstra 2018-09-25 16:37 ` Peter Zijlstra 2018-10-02 15:29 ` Borislav Petkov 2018-10-02 15:29 ` Borislav Petkov 2018-10-02 15:29 ` Borislav Petkov 2018-10-02 16:21 ` Yu-cheng Yu 2018-10-02 16:21 ` Yu-cheng Yu 2018-10-02 16:21 ` Yu-cheng Yu 2018-10-02 16:30 ` Dave Hansen 2018-10-02 16:30 ` Dave Hansen 2018-10-02 16:30 ` Dave Hansen 2018-10-02 16:37 ` Borislav Petkov 2018-10-02 16:37 ` Borislav Petkov 2018-10-02 16:39 ` Dave Hansen 2018-10-02 16:39 ` Dave Hansen 2018-10-02 16:43 ` Yu-cheng Yu 2018-10-02 16:43 ` Yu-cheng Yu 2018-09-21 15:03 ` [RFC PATCH v4 03/27] x86/fpu/xstate: Enable XSAVES system states Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-09-25 17:03 ` Peter Zijlstra 2018-09-25 17:03 ` Peter Zijlstra 2018-09-25 17:23 ` Yu-cheng Yu 2018-09-25 17:23 ` Yu-cheng Yu 2018-10-02 17:15 ` Borislav Petkov 2018-10-02 17:15 ` Borislav Petkov 2018-10-04 15:47 ` Yu-cheng Yu 2018-10-04 15:47 ` Yu-cheng Yu 2018-09-21 15:03 ` [RFC PATCH v4 04/27] x86/fpu/xstate: Add XSAVES system states for shadow stack Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-09-21 15:03 ` [RFC PATCH v4 05/27] Documentation/x86: Add CET description Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-09-21 15:03 ` [RFC PATCH v4 06/27] x86/cet: Control protection exception handler Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-10-03 10:39 ` Eugene Syromiatnikov 2018-10-03 10:39 ` Eugene Syromiatnikov 2018-10-03 16:11 ` Yu-cheng Yu 2018-10-03 16:11 ` Yu-cheng Yu 2018-09-21 15:03 ` [RFC PATCH v4 07/27] x86/cet/shstk: Add Kconfig option for user-mode shadow stack Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-09-21 15:03 ` [RFC PATCH v4 08/27] mm: Introduce VM_SHSTK for shadow stack memory Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-09-21 15:03 ` [RFC PATCH v4 09/27] x86/mm: Change _PAGE_DIRTY to _PAGE_DIRTY_HW Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-10-03 13:38 ` Matthew Wilcox 2018-10-03 13:38 ` Matthew Wilcox 2018-10-03 14:05 ` Dave Hansen 2018-10-03 14:05 ` Dave Hansen 2018-10-03 16:07 ` Yu-cheng Yu 2018-10-03 16:07 ` Yu-cheng Yu 2018-09-21 15:03 ` [RFC PATCH v4 10/27] drm/i915/gvt: Update _PAGE_DIRTY to _PAGE_DIRTY_BITS Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-10-03 13:19 ` Eugene Syromiatnikov 2018-10-03 13:19 ` Eugene Syromiatnikov 2018-09-21 15:03 ` [RFC PATCH v4 11/27] x86/mm: Introduce _PAGE_DIRTY_SW Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-09-21 15:03 ` [RFC PATCH v4 12/27] x86/mm: Modify ptep_set_wrprotect and pmdp_set_wrprotect for _PAGE_DIRTY_SW Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu [this message] 2018-09-21 15:03 ` [RFC PATCH v4 13/27] x86/mm: Shadow stack page fault error checking Yu-cheng Yu 2018-09-21 15:03 ` [RFC PATCH v4 14/27] mm: Handle shadow stack page fault Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-09-21 15:03 ` [RFC PATCH v4 15/27] mm: Handle THP/HugeTLB " Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-09-21 15:03 ` [RFC PATCH v4 16/27] mm: Update can_follow_write_pte/pmd for shadow stack Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-09-21 15:03 ` [RFC PATCH v4 17/27] mm: Introduce do_mmap_locked() Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-09-21 15:03 ` [RFC PATCH v4 18/27] x86/cet/shstk: User-mode shadow stack support Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-10-03 15:08 ` Eugene Syromiatnikov 2018-10-03 15:08 ` Eugene Syromiatnikov 2018-10-03 15:12 ` Yu-cheng Yu 2018-10-03 15:12 ` Yu-cheng Yu 2018-09-21 15:03 ` [RFC PATCH v4 19/27] x86/cet/shstk: Introduce WRUSS instruction Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-10-03 4:15 ` Eugene Syromiatnikov 2018-10-03 4:15 ` Eugene Syromiatnikov 2018-09-21 15:03 ` [RFC PATCH v4 20/27] x86/cet/shstk: Signal handling for shadow stack Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-10-03 14:36 ` Eugene Syromiatnikov 2018-10-03 14:36 ` Eugene Syromiatnikov 2018-10-03 16:46 ` Jann Horn 2018-10-03 16:46 ` Jann Horn 2018-09-21 15:03 ` [RFC PATCH v4 21/27] x86/cet/shstk: ELF header parsing of Shadow Stack Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-10-03 23:27 ` Eugene Syromiatnikov 2018-10-03 23:27 ` Eugene Syromiatnikov 2018-10-09 21:15 ` Yu-cheng Yu 2018-10-09 21:15 ` Yu-cheng Yu 2018-10-15 23:40 ` Kees Cook 2018-10-15 23:40 ` Kees Cook 2018-10-16 17:23 ` Yu-cheng Yu 2018-10-16 17:23 ` Yu-cheng Yu 2018-09-21 15:03 ` [RFC PATCH v4 22/27] x86/cet/shstk: Handle thread shadow stack Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-09-21 15:03 ` [RFC PATCH v4 23/27] mm/map: Add Shadow stack pages to memory accounting Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-09-21 16:55 ` Randy Dunlap 2018-09-21 16:55 ` Randy Dunlap 2018-09-21 17:21 ` Yu-cheng Yu 2018-09-21 17:21 ` Yu-cheng Yu 2018-09-21 15:03 ` [RFC PATCH v4 24/27] mm/mmap: Create a guard area between VMAs Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-10-03 4:56 ` Eugene Syromiatnikov 2018-10-03 4:56 ` Eugene Syromiatnikov 2018-10-03 5:36 ` Andy Lutomirski 2018-10-03 5:36 ` Andy Lutomirski 2018-10-03 16:00 ` Yu-cheng Yu 2018-10-03 16:00 ` Yu-cheng Yu 2018-10-03 16:18 ` Andy Lutomirski 2018-10-03 16:18 ` Andy Lutomirski 2018-10-03 16:32 ` Eugene Syromiatnikov 2018-10-03 16:32 ` Eugene Syromiatnikov 2018-10-03 16:40 ` Yu-cheng Yu 2018-10-03 16:40 ` Yu-cheng Yu 2018-10-03 16:52 ` Jann Horn 2018-10-03 16:52 ` Jann Horn 2018-10-03 21:21 ` Eugene Syromiatnikov 2018-10-03 21:21 ` Eugene Syromiatnikov 2018-09-21 15:03 ` [RFC PATCH v4 25/27] mm/mmap: Prevent Shadow Stack VMA merges Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-09-21 15:03 ` [RFC PATCH v4 26/27] x86/cet/shstk: Add arch_prctl functions for Shadow Stack Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-10-03 17:57 ` Eugene Syromiatnikov 2018-10-03 17:57 ` Eugene Syromiatnikov 2018-09-21 15:03 ` [RFC PATCH v4 27/27] x86/cet/shstk: Add Shadow Stack instructions to opcode map Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-09-21 22:53 ` [RFC PATCH v4 00/27] Control Flow Enforcement: Shadow Stack Dave Hansen 2018-09-21 22:53 ` Dave Hansen 2018-09-24 15:25 ` Yu-cheng Yu 2018-09-24 15:25 ` Yu-cheng Yu
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