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* Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds2016-05-251-3/+8
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Ingo Molnar: "Misc fixes: EFI, entry code, pkeys and MPX fixes, TASK_SIZE cleanups and a tsc frequency table fix" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mm: Switch from TASK_SIZE to TASK_SIZE_MAX in the page fault code x86/fsgsbase/64: Use TASK_SIZE_MAX for FSBASE/GSBASE upper limits x86/mm/mpx: Work around MPX erratum SKD046 x86/entry/64: Fix stack return address retrieval in thunk x86/efi: Fix 7-parameter efi_call()s x86/cpufeature, x86/mm/pkeys: Fix broken compile-time disabling of pkeys x86/tsc: Add missing Cherrytrail frequency to the table
| * x86/mm: Switch from TASK_SIZE to TASK_SIZE_MAX in the page fault codeAndy Lutomirski2016-05-201-3/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | x86's page fault handlers had two TASK_SIZE uses that should have been TASK_SIZE_MAX. I don't think that either one had a visible effect, but this makes the code clearer and should save a few bytes of text. (And I eventually want to eradicate TASK_SIZE. This will help.) Reported-by: Cyrill Gorcunov <gorcunov@gmail.com> Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Dmitry Safonov <0x7f454c46@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ruslan Kabatsayev <b7.10110111@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1242fb23b0d05c3069dbf5758ac55d26bc114bef.1462914565.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | x86: mm: use hugetlb_bad_size()Vaishali Thakkar2016-05-191-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Update setup_hugepagesz() to call hugetlb_bad_size() when unsupported hugepage size is found. Signed-off-by: Vaishali Thakkar <vaishali.thakkar@oracle.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Yaowei Bai <baiyaowei@cmss.chinamobile.com> Cc: Dominik Dingel <dingel@linux.vnet.ibm.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | include/linux/nodemask.h: create next_node_in() helperAndrew Morton2016-05-191-3/+1
|/ | | | | | | | | | | | | | | | | | | | | | | | | Lots of code does node = next_node(node, XXX); if (node == MAX_NUMNODES) node = first_node(XXX); so create next_node_in() to do this and use it in various places. [mhocko@suse.com: use next_node_in() helper] Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@kernel.org> Signed-off-by: Michal Hocko <mhocko@suse.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Joonsoo Kim <js1304@gmail.com> Cc: David Rientjes <rientjes@google.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Laura Abbott <lauraa@codeaurora.org> Cc: Hui Zhu <zhuhui@xiaomi.com> Cc: Wang Xiaoqiang <wangxq10@lzu.edu.cn> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'x86-boot-for-linus' of ↵Linus Torvalds2016-05-163-76/+80
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 boot updates from Ingo Molnar: "The biggest changes in this cycle were: - prepare for more KASLR related changes, by restructuring, cleaning up and fixing the existing boot code. (Kees Cook, Baoquan He, Yinghai Lu) - simplifly/concentrate subarch handling code, eliminate paravirt_enabled() usage. (Luis R Rodriguez)" * 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (50 commits) x86/KASLR: Clarify purpose of each get_random_long() x86/KASLR: Add virtual address choosing function x86/KASLR: Return earliest overlap when avoiding regions x86/KASLR: Add 'struct slot_area' to manage random_addr slots x86/boot: Add missing file header comments x86/KASLR: Initialize mapping_info every time x86/boot: Comment what finalize_identity_maps() does x86/KASLR: Build identity mappings on demand x86/boot: Split out kernel_ident_mapping_init() x86/boot: Clean up indenting for asm/boot.h x86/KASLR: Improve comments around the mem_avoid[] logic x86/boot: Simplify pointer casting in choose_random_location() x86/KASLR: Consolidate mem_avoid[] entries x86/boot: Clean up pointer casting x86/boot: Warn on future overlapping memcpy() use x86/boot: Extract error reporting functions x86/boot: Correctly bounds-check relocations x86/KASLR: Clean up unused code from old 'run_size' and rename it to 'kernel_total_size' x86/boot: Fix "run_size" calculation x86/boot: Calculate decompression size during boot not build ...
| * x86/boot: Add missing file header commentsKees Cook2016-05-101-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There were some files with missing header comments. Since they are included from both compressed and regular kernels, make note of that. Also corrects a typo in the mem_avoid comments. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Young <dyoung@redhat.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: kernel-hardening@lists.openwall.com Cc: lasse.collin@tukaani.org Link: http://lkml.kernel.org/r/1462825332-10505-3-git-send-email-keescook@chromium.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * x86/boot: Split out kernel_ident_mapping_init()Yinghai Lu2016-05-072-73/+75
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In order to support on-demand page table creation when moving the kernel for KASLR, we need to use kernel_ident_mapping_init() in the decompression code. This splits it out into its own file for use outside of init_64.c. Additionally, checking for __pa/__va defines is added since they need to be overridden in the decompression code. [kees: rewrote changelog] Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Young <dyoung@redhat.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: kernel-hardening@lists.openwall.com Cc: lasse.collin@tukaani.org Link: http://lkml.kernel.org/r/1462572095-11754-3-git-send-email-keescook@chromium.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * x86/KASLR: Drop CONFIG_RANDOMIZE_BASE_MAX_OFFSETBaoquan He2016-04-221-3/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently CONFIG_RANDOMIZE_BASE_MAX_OFFSET is used to limit the maximum offset for kernel randomization. This limit doesn't need to be a CONFIG since it is tied completely to KERNEL_IMAGE_SIZE, and will make no sense once physical and virtual offsets are randomized separately. This patch removes CONFIG_RANDOMIZE_BASE_MAX_OFFSET and consolidates the Kconfig help text. [kees: rewrote changelog, dropped KERNEL_IMAGE_SIZE_DEFAULT, rewrote help] Signed-off-by: Baoquan He <bhe@redhat.com> Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: H.J. Lu <hjl.tools@gmail.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1461185746-8017-3-git-send-email-keescook@chromium.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | Merge branch 'x86-asm-for-linus' of ↵Linus Torvalds2016-05-168-73/+158
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 asm updates from Ingo Molnar: "The main changes in this cycle were: - MSR access API fixes and enhancements (Andy Lutomirski) - early exception handling improvements (Andy Lutomirski) - user-space FS/GS prctl usage fixes and improvements (Andy Lutomirski) - Remove the cpu_has_*() APIs and replace them with equivalents (Borislav Petkov) - task switch micro-optimization (Brian Gerst) - 32-bit entry code simplification (Denys Vlasenko) - enhance PAT handling in enumated CPUs (Toshi Kani) ... and lots of other cleanups/fixlets" * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (70 commits) x86/arch_prctl/64: Restore accidentally removed put_cpu() in ARCH_SET_GS x86/entry/32: Remove asmlinkage_protect() x86/entry/32: Remove GET_THREAD_INFO() from entry code x86/entry, sched/x86: Don't save/restore EFLAGS on task switch x86/asm/entry/32: Simplify pushes of zeroed pt_regs->REGs selftests/x86/ldt_gdt: Test set_thread_area() deletion of an active segment x86/tls: Synchronize segment registers in set_thread_area() x86/asm/64: Rename thread_struct's fs and gs to fsbase and gsbase x86/arch_prctl/64: Remove FSBASE/GSBASE < 4G optimization x86/segments/64: When load_gs_index fails, clear the base x86/segments/64: When loadsegment(fs, ...) fails, clear the base x86/asm: Make asm/alternative.h safe from assembly x86/asm: Stop depending on ptrace.h in alternative.h x86/entry: Rename is_{ia32,x32}_task() to in_{ia32,x32}_syscall() x86/asm: Make sure verify_cpu() has a good stack x86/extable: Add a comment about early exception handlers x86/msr: Set the return value to zero when native_rdmsr_safe() fails x86/paravirt: Make "unsafe" MSR accesses unsafe even if PARAVIRT=y x86/paravirt: Add paravirt_{read,write}_msr() x86/msr: Carry on after a non-"safe" MSR access fails ...
| * | x86/segments/64: When loadsegment(fs, ...) fails, clear the baseAndy Lutomirski2016-04-291-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On AMD CPUs, a failed loadsegment currently may not clear the FS base. Fix it. While we're at it, prevent loadsegment(gs, xyz) from even compiling on 64-bit kernels. It shouldn't be used. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/a084c1b93b7b1408b58d3fd0b5d6e47da8e7d7cf.1461698311.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | Merge branch 'x86/urgent' into x86/asm, to refresh the treeIngo Molnar2016-04-291-2/+3
| |\ \ | | | | | | | | | | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * \ \ Merge tag 'v4.6-rc4' into x86/asm, to pick up fixesIngo Molnar2016-04-191-4/+10
| |\ \ \ | | | |/ | | |/| | | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | x86/extable: Add a comment about early exception handlersAndy Lutomirski2016-04-131-0/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Borislav asked for a comment explaining why all exception handlers are allowed early. Signed-off-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Borislav Petkov <bp@suse.de> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: KVM list <kvm@vger.kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: xen-devel <Xen-devel@lists.xen.org> Link: http://lkml.kernel.org/r/5f1dcd6919f4a5923959a8065cb2c04d9dac1412.1459784772.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | x86/msr: Carry on after a non-"safe" MSR access failsAndy Lutomirski2016-04-131-0/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This demotes an OOPS and likely panic due to a failed non-"safe" MSR access to a WARN_ONCE() and, for RDMSR, a return value of zero. To be clear, this type of failure should *not* happen. This patch exists to minimize the chance of nasty undebuggable failures happening when a CONFIG_PARAVIRT=y bug in the non-"safe" MSR helpers gets fixed. Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: KVM list <kvm@vger.kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: xen-devel <Xen-devel@lists.xen.org> Link: http://lkml.kernel.org/r/26567b216aae70e795938f4b567eace5a0eb90ba.1459605520.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | x86/traps: Enable all exception handler callbacks earlyAndy Lutomirski2016-04-131-17/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that early_fixup_exception() has pt_regs, we can just call fixup_exception() from it. This will make fancy exception handlers work early. Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: KVM list <kvm@vger.kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: xen-devel <Xen-devel@lists.xen.org> Link: http://lkml.kernel.org/r/20fc047d926150cb08cb9b9f2923519b07ec1a15.1459605520.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | x86/head: Move early exception panic code into early_fixup_exception()Andy Lutomirski2016-04-131-5/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This removes a bunch of assembly and adds some C code instead. It changes the actual printouts on both 32-bit and 64-bit kernels, but they still seem okay. Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: KVM list <kvm@vger.kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: xen-devel <Xen-devel@lists.xen.org> Link: http://lkml.kernel.org/r/4085070316fc3ab29538d3fcfe282648d1d4ee2e.1459605520.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | x86/head: Move the early NMI fixup into CAndy Lutomirski2016-04-131-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | C is nicer than asm. Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: KVM list <kvm@vger.kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: xen-devel <Xen-devel@lists.xen.org> Link: http://lkml.kernel.org/r/dd068269f8d59fe44e9e43a50d0efd67da65c2b5.1459605520.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | x86/head: Pass a real pt_regs and trapnr to early_fixup_exception()Andy Lutomirski2016-04-131-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | early_fixup_exception() is limited by the fact that it doesn't have a real struct pt_regs. Change both the 32-bit and 64-bit asm and the C code to pass and accept a real pt_regs. Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: KVM list <kvm@vger.kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: xen-devel <Xen-devel@lists.xen.org> Link: http://lkml.kernel.org/r/e3fb680fcfd5e23e38237e8328b64a25cc121d37.1459605520.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | Merge branch 'x86/mm' into x86/asm to resolve conflict and to create common baseIngo Molnar2016-04-131-42/+67
| |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: arch/x86/include/asm/cpufeature.h Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | | x86/mm/pat: Fix BUG_ON() in mmap_mem() on QEMU/i386Toshi Kani2016-04-131-19/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The following BUG_ON() crash was reported on QEMU/i386: kernel BUG at arch/x86/mm/physaddr.c:79! Call Trace: phys_mem_access_prot_allowed mmap_mem ? mmap_region mmap_region do_mmap vm_mmap_pgoff SyS_mmap_pgoff do_int80_syscall_32 entry_INT80_32 after commit: edfe63ec97ed ("x86/mtrr: Fix Xorg crashes in Qemu sessions") PAT is now set to disabled state when MTRRs are disabled. Thus, reactivating the __pa(high_memory) check in phys_mem_access_prot_allowed(). When CONFIG_DEBUG_VIRTUAL is set, __pa() calls __phys_addr(), which in turn calls slow_virt_to_phys() for 'high_memory'. Because 'high_memory' is set to (the max direct mapped virt addr + 1), it is not a valid virtual address. Hence, slow_virt_to_phys() returns 0 and hit the BUG_ON. Using __pa_nodebug() instead of __pa() will fix this BUG_ON. However, this code block, originally written for Pentiums and earlier, is no longer adequate since a 32-bit Xen guest has MTRRs disabled and supports ZONE_HIGHMEM. In this setup, this code sets UC attribute for accessing RAM in high memory range. Delete this code block as it has been unused for a long time. Reported-by: kernel test robot <ying.huang@linux.intel.com> Reviewed-by: Borislav Petkov <bp@suse.de> Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/1460403360-25441-1-git-send-email-toshi.kani@hpe.com Link: https://lkml.org/lkml/2016/4/1/608 Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | | x86/xen, pat: Remove PAT table init code from XenToshi Kani2016-03-291-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Xen supports PAT without MTRRs for its guests. In order to enable WC attribute, it was necessary for xen_start_kernel() to call pat_init_cache_modes() to update PAT table before starting guest kernel. Now that the kernel initializes PAT table to the BIOS handoff state when MTRR is disabled, this Xen-specific PAT init code is no longer necessary. Delete it from xen_start_kernel(). Also change __init_cache_modes() to a static function since PAT table should not be tweaked by other modules. Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Juergen Gross <jgross@suse.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Toshi Kani <toshi.kani@hp.com> Cc: elliott@hpe.com Cc: paul.gortmaker@windriver.com Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/1458769323-24491-7-git-send-email-toshi.kani@hpe.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | | x86/mm/pat: Replace cpu_has_pat with boot_cpu_has()Toshi Kani2016-03-291-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Borislav Petkov suggested: > Please use on init paths boot_cpu_has(X86_FEATURE_PAT) and on fast > paths static_cpu_has(X86_FEATURE_PAT). No more of that cpu_has_XXX > ugliness. Replace the use of cpu_has_pat on init paths with boot_cpu_has(). Suggested-by: Borislav Petkov <bp@suse.de> Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Robert Elliott <elliott@hpe.com> Cc: Toshi Kani <toshi.kani@hp.com> Cc: konrad.wilk@oracle.com Cc: paul.gortmaker@windriver.com Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/1458769323-24491-4-git-send-email-toshi.kani@hpe.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | | x86/mm/pat: Add pat_disable() interfaceToshi Kani2016-03-291-1/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In preparation for fixing a regression caused by: 9cd25aac1f44 ("x86/mm/pat: Emulate PAT when it is disabled") ... PAT needs to provide an interface that prevents the OS from initializing the PAT MSR. PAT MSR initialization must be done on all CPUs using the specific sequence of operations defined in the Intel SDM. This requires MTRRs to be enabled since pat_init() is called as part of MTRR init from mtrr_rendezvous_handler(). Make pat_disable() as the interface that prevents the OS from initializing the PAT MSR. MTRR will call this interface when it cannot provide the SDM-defined sequence to initialize PAT. This also assures that pat_disable() called from pat_bsp_init() will set the PAT table properly when CPU does not support PAT. Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Robert Elliott <elliott@hpe.com> Cc: Toshi Kani <toshi.kani@hp.com> Cc: konrad.wilk@oracle.com Cc: paul.gortmaker@windriver.com Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/1458769323-24491-3-git-send-email-toshi.kani@hpe.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | | x86/mm/pat: Add support of non-default PAT MSR settingToshi Kani2016-03-291-20/+53
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In preparation for fixing a regression caused by: 9cd25aac1f44 ("x86/mm/pat: Emulate PAT when it is disabled")' ... PAT needs to support a case that PAT MSR is initialized with a non-default value. When pat_init() is called and PAT is disabled, it initializes the PAT table with the BIOS default value. Xen, however, sets PAT MSR with a non-default value to enable WC. This causes inconsistency between the PAT table and PAT MSR when PAT is set to disable on Xen. Change pat_init() to handle the PAT disable cases properly. Add init_cache_modes() to handle two cases when PAT is set to disable. 1. CPU supports PAT: Set PAT table to be consistent with PAT MSR. 2. CPU does not support PAT: Set PAT table to be consistent with PWT and PCD bits in a PTE. Note, __init_cache_modes(), renamed from pat_init_cache_modes(), will be changed to a static function in a later patch. Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Toshi Kani <toshi.kani@hp.com> Cc: elliott@hpe.com Cc: konrad.wilk@oracle.com Cc: paul.gortmaker@windriver.com Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/1458769323-24491-2-git-send-email-toshi.kani@hpe.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | x86/cpufeature: Remove cpu_has_pseBorislav Petkov2016-03-314-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1459266123-21878-11-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | x86/cpufeature: Remove cpu_has_pgeBorislav Petkov2016-03-311-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use static_cpu_has() in __flush_tlb_all() due to the time-sensitivity of this one. Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1459266123-21878-10-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | x86/cpufeature: Remove cpu_has_clflushBorislav Petkov2016-03-311-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use the fast variant in the DRM code. Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dri-devel@lists.freedesktop.org Cc: intel-gfx@lists.freedesktop.org Link: http://lkml.kernel.org/r/1459266123-21878-7-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | x86/cpufeature: Remove cpu_has_gbpagesBorislav Petkov2016-03-314-5/+5
| |/ / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1459266123-21878-6-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | Merge branch 'sched-core-for-linus' of ↵Linus Torvalds2016-05-162-2/+117
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: - massive CPU hotplug rework (Thomas Gleixner) - improve migration fairness (Peter Zijlstra) - CPU load calculation updates/cleanups (Yuyang Du) - cpufreq updates (Steve Muckle) - nohz optimizations (Frederic Weisbecker) - switch_mm() micro-optimization on x86 (Andy Lutomirski) - ... lots of other enhancements, fixes and cleanups. * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (66 commits) ARM: Hide finish_arch_post_lock_switch() from modules sched/core: Provide a tsk_nr_cpus_allowed() helper sched/core: Use tsk_cpus_allowed() instead of accessing ->cpus_allowed sched/loadavg: Fix loadavg artifacts on fully idle and on fully loaded systems sched/fair: Correct unit of load_above_capacity sched/fair: Clean up scale confusion sched/nohz: Fix affine unpinned timers mess sched/fair: Fix fairness issue on migration sched/core: Kill sched_class::task_waking to clean up the migration logic sched/fair: Prepare to fix fairness problems on migration sched/fair: Move record_wakee() sched/core: Fix comment typo in wake_q_add() sched/core: Remove unused variable sched: Make hrtick_notifier an explicit call sched/fair: Make ilb_notifier an explicit call sched/hotplug: Make activate() the last hotplug step sched/hotplug: Move migration CPU_DYING to sched_cpu_dying() sched/migration: Move CPU_ONLINE into scheduler state sched/migration: Move calc_load_migrate() into CPU_DYING sched/migration: Move prepare transition to SCHED_STARTING state ...
| * \ \ \ Merge branch 'sched/urgent' into sched/core to pick up fixesIngo Molnar2016-05-121-2/+3
| |\ \ \ \ | | | |_|/ | | |/| | | | | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | x86/mm, sched/core: Turn off IRQs in switch_mm()Andy Lutomirski2016-04-281-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Potential races between switch_mm() and TLB-flush or LDT-flush IPIs could be very messy. AFAICT the code is currently okay, whether by accident or by careful design, but enabling PCID will make it considerably more complicated and will no longer be obviously safe. Fix it with a big hammer: run switch_mm() with IRQs off. To avoid a performance hit in the scheduler, we take advantage of our knowledge that the scheduler already has IRQs disabled when it calls switch_mm(). Signed-off-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Borislav Petkov <bp@suse.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/f19baf759693c9dcae64bbff76189db77cb13398.1461688545.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | x86/mm, sched/core: Uninline switch_mm()Andy Lutomirski2016-04-281-0/+102
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It's fairly large and it has quite a few callers. This may also help untangle some headers down the road. Signed-off-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Borislav Petkov <bp@suse.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/54f3367803e7f80b2be62c8a21879aa74b1a5f57.1461688545.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | x86/mm: Build arch/x86/mm/tlb.c even on !SMPAndy Lutomirski2016-04-282-2/+5
| | |_|/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently all of the functions that live in tlb.c are inlined on !SMP builds. One can debate whether this is a good idea (in many respects the code in tlb.c is better than the inlined UP code). Regardless, I want to add code that needs to be built on UP and SMP kernels and relates to tlb flushing, so arrange for tlb.c to be compiled unconditionally. Signed-off-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Borislav Petkov <bp@suse.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/f0d778f0d828fc46e5d1946bca80f0aaf9abf032.1461688545.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | Merge branch 'linus' into efi/core, to pick up fixesIngo Molnar2016-05-071-2/+3
|\ \ \ \ | | |/ / | |/| | | | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | Revert "x86/mm/32: Set NX in __supported_pte_mask before enabling paging"Andy Lutomirski2016-04-261-2/+3
| |/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commit 320d25b6a05f8b73c23fc21025d2906ecdd2d4fc. This change was problematic for a couple of reasons: 1. It missed a some entry points (Xen things and 64-bit native). 2. The entry it changed can be executed more than once. This isn't really a problem, but it conflated per-cpu state setup and global state setup. 3. It broke 64-bit non-NX. 64-bit non-NX worked the other way around from 32-bit -- __supported_pte_mask had NX set initially and was *cleared* in x86_configure_nx. With the patch applied, it never got cleared. Reported-and-tested-by: Meelis Roos <mroos@linux.ee> Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/59bd15f7f4b56b633a611b7f70876c6d2ad01a98.1461685884.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* / / x86/mm/pat: Document the (currently) EFI-only code pathMatt Fleming2016-04-281-1/+7
|/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It's not at all obvious that populate_pgd() and friends are only executed when mapping EFI virtual memory regions or that no other pageattr callers pass a ->pgd value. Reported-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1461614832-17633-4-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | mm/rmap: batched invalidations should use existing apiNadav Amit2016-04-011-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The recently introduced batched invalidations mechanism uses its own mechanism for shootdown. However, it does wrong accounting of interrupts (e.g., inc_irq_stat is called for local invalidations), trace-points (e.g., TLB_REMOTE_SHOOTDOWN for local invalidations) and may break some platforms as it bypasses the invalidation mechanisms of Xen and SGI UV. This patch reuses the existing TLB flushing mechnaisms instead. We use NULL as mm to indicate a global invalidation is required. Fixes 72b252aed506b8 ("mm: send one IPI per CPU to TLB flush all entries after unmapping pages") Signed-off-by: Nadav Amit <namit@vmware.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | x86/mm: TLB_REMOTE_SEND_IPI should count pagesNadav Amit2016-04-011-3/+9
|/ | | | | | | | | | | | | | | | TLB_REMOTE_SEND_IPI was recently introduced, but it counts bytes instead of pages. In addition, it does not report correctly the case in which flush_tlb_page flushes a page. Fix it to be consistent with other TLB counters. Fixes: 5b74283ab251b9d ("x86, mm: trace when an IPI is about to be sent") Signed-off-by: Nadav Amit <namit@vmware.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds2016-03-242-3/+3
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Ingo Molnar: "Misc fixes: - fix hotplug bugs - fix irq live lock - fix various topology handling bugs - fix APIC ACK ordering - fix PV iopl handling - fix speling - fix/tweak memcpy_mcsafe() return value - fix fbcon bug - remove stray prototypes" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/msr: Remove unused native_read_tscp() x86/apic: Remove declaration of unused hw_nmi_is_cpu_stuck x86/oprofile/nmi: Add missing hotplug FROZEN handling x86/hpet: Use proper mask to modify hotplug action x86/apic/uv: Fix the hotplug notifier x86/apb/timer: Use proper mask to modify hotplug action x86/topology: Use total_cpus not nr_cpu_ids for logical packages x86/topology: Fix Intel HT disable x86/topology: Fix logical package mapping x86/irq: Cure live lock in fixup_irqs() x86/tsc: Prevent NULL pointer deref in calibrate_delay_is_known() x86/apic: Fix suspicious RCU usage in smp_trace_call_function_interrupt() x86/iopl: Fix iopl capability check on Xen PV x86/iopl/64: Properly context-switch IOPL on Xen PV selftests/x86: Add an iopl test x86/mm, x86/mce: Fix return type/value for memcpy_mcsafe() x86/video: Don't assume all FB devices are PCI devices arch/x86/irq: Purge useless handler declarations from hw_irq.h x86: Fix misspellings in comments
| * Merge branch 'x86/cleanups' into x86/urgentIngo Molnar2016-03-172-3/+3
| |\ | | | | | | | | | | | | | | | Pull in some merge window leftovers. Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * x86: Fix misspellings in commentsAdam Buchbinder2016-02-242-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Adam Buchbinder <adam.buchbinder@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: trivial@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | x86/extable: use generic search and sort routinesArd Biesheuvel2016-03-221-108/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Replace the arch specific versions of search_extable() and sort_extable() with calls to the generic ones, which now support relative exception tables as well. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | kernel: add kcov code coverageDmitry Vyukov2016-03-221-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kcov provides code coverage collection for coverage-guided fuzzing (randomized testing). Coverage-guided fuzzing is a testing technique that uses coverage feedback to determine new interesting inputs to a system. A notable user-space example is AFL (http://lcamtuf.coredump.cx/afl/). However, this technique is not widely used for kernel testing due to missing compiler and kernel support. kcov does not aim to collect as much coverage as possible. It aims to collect more or less stable coverage that is function of syscall inputs. To achieve this goal it does not collect coverage in soft/hard interrupts and instrumentation of some inherently non-deterministic or non-interesting parts of kernel is disbled (e.g. scheduler, locking). Currently there is a single coverage collection mode (tracing), but the API anticipates additional collection modes. Initially I also implemented a second mode which exposes coverage in a fixed-size hash table of counters (what Quentin used in his original patch). I've dropped the second mode for simplicity. This patch adds the necessary support on kernel side. The complimentary compiler support was added in gcc revision 231296. We've used this support to build syzkaller system call fuzzer, which has found 90 kernel bugs in just 2 months: https://github.com/google/syzkaller/wiki/Found-Bugs We've also found 30+ bugs in our internal systems with syzkaller. Another (yet unexplored) direction where kcov coverage would greatly help is more traditional "blob mutation". For example, mounting a random blob as a filesystem, or receiving a random blob over wire. Why not gcov. Typical fuzzing loop looks as follows: (1) reset coverage, (2) execute a bit of code, (3) collect coverage, repeat. A typical coverage can be just a dozen of basic blocks (e.g. an invalid input). In such context gcov becomes prohibitively expensive as reset/collect coverage steps depend on total number of basic blocks/edges in program (in case of kernel it is about 2M). Cost of kcov depends only on number of executed basic blocks/edges. On top of that, kernel requires per-thread coverage because there are always background threads and unrelated processes that also produce coverage. With inlined gcov instrumentation per-thread coverage is not possible. kcov exposes kernel PCs and control flow to user-space which is insecure. But debugfs should not be mapped as user accessible. Based on a patch by Quentin Casasnovas. [akpm@linux-foundation.org: make task_struct.kcov_mode have type `enum kcov_mode'] [akpm@linux-foundation.org: unbreak allmodconfig] [akpm@linux-foundation.org: follow x86 Makefile layout standards] Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: syzkaller <syzkaller@googlegroups.com> Cc: Vegard Nossum <vegard.nossum@oracle.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Tavis Ormandy <taviso@google.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Kostya Serebryany <kcc@google.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Kees Cook <keescook@google.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: David Drysdale <drysdale@google.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | Merge branch 'mm-pkeys-for-linus' of ↵Linus Torvalds2016-03-205-41/+261
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 protection key support from Ingo Molnar: "This tree adds support for a new memory protection hardware feature that is available in upcoming Intel CPUs: 'protection keys' (pkeys). There's a background article at LWN.net: https://lwn.net/Articles/643797/ The gist is that protection keys allow the encoding of user-controllable permission masks in the pte. So instead of having a fixed protection mask in the pte (which needs a system call to change and works on a per page basis), the user can map a (handful of) protection mask variants and can change the masks runtime relatively cheaply, without having to change every single page in the affected virtual memory range. This allows the dynamic switching of the protection bits of large amounts of virtual memory, via user-space instructions. It also allows more precise control of MMU permission bits: for example the executable bit is separate from the read bit (see more about that below). This tree adds the MM infrastructure and low level x86 glue needed for that, plus it adds a high level API to make use of protection keys - if a user-space application calls: mmap(..., PROT_EXEC); or mprotect(ptr, sz, PROT_EXEC); (note PROT_EXEC-only, without PROT_READ/WRITE), the kernel will notice this special case, and will set a special protection key on this memory range. It also sets the appropriate bits in the Protection Keys User Rights (PKRU) register so that the memory becomes unreadable and unwritable. So using protection keys the kernel is able to implement 'true' PROT_EXEC on x86 CPUs: without protection keys PROT_EXEC implies PROT_READ as well. Unreadable executable mappings have security advantages: they cannot be read via information leaks to figure out ASLR details, nor can they be scanned for ROP gadgets - and they cannot be used by exploits for data purposes either. We know about no user-space code that relies on pure PROT_EXEC mappings today, but binary loaders could start making use of this new feature to map binaries and libraries in a more secure fashion. There is other pending pkeys work that offers more high level system call APIs to manage protection keys - but those are not part of this pull request. Right now there's a Kconfig that controls this feature (CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS) that is default enabled (like most x86 CPU feature enablement code that has no runtime overhead), but it's not user-configurable at the moment. If there's any serious problem with this then we can make it configurable and/or flip the default" * 'mm-pkeys-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (38 commits) x86/mm/pkeys: Fix mismerge of protection keys CPUID bits mm/pkeys: Fix siginfo ABI breakage caused by new u64 field x86/mm/pkeys: Fix access_error() denial of writes to write-only VMA mm/core, x86/mm/pkeys: Add execute-only protection keys support x86/mm/pkeys: Create an x86 arch_calc_vm_prot_bits() for VMA flags x86/mm/pkeys: Allow kernel to modify user pkey rights register x86/fpu: Allow setting of XSAVE state x86/mm: Factor out LDT init from context init mm/core, x86/mm/pkeys: Add arch_validate_pkey() mm/core, arch, powerpc: Pass a protection key in to calc_vm_flag_bits() x86/mm/pkeys: Actually enable Memory Protection Keys in the CPU x86/mm/pkeys: Add Kconfig prompt to existing config option x86/mm/pkeys: Dump pkey from VMA in /proc/pid/smaps x86/mm/pkeys: Dump PKRU with other kernel registers mm/core, x86/mm/pkeys: Differentiate instruction fetches x86/mm/pkeys: Optimize fault handling in access_error() mm/core: Do not enforce PKEY permissions on remote mm access um, pkeys: Add UML arch_*_access_permitted() methods mm/gup, x86/mm/pkeys: Check VMAs and PTEs for protection keys x86/mm/gup: Simplify get_user_pages() PTE bit handling ...
| * | | x86/mm/pkeys: Fix access_error() denial of writes to write-only VMADave Hansen2016-03-031-18/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Andrey Wagin reported that a simple test case was broken by: 2b5f7d013fc ("mm/core, x86/mm/pkeys: Add execute-only protection keys support") This test case creates an unreadable VMA and my patch assumed that all writes must be to readable VMAs. The simplest fix for this is to remove the pkey-related bits in access_error(). For execute-only support, I believe the existing version is sufficient because the permissions we are trying to enforce are entirely expressed in vma->vm_flags. We just depend on pkeys to get *an* exception, it does not matter that PF_PK was set, or even what state PKRU is in. I will re-add the necessary bits with the full pkeys implementation that includes the new syscalls. The three cases that matter are: 1. If a write to an execute-only VMA occurs, we will see PF_WRITE set, but !VM_WRITE on the VMA, and return 1. All execute-only VMAs have VM_WRITE clear by definition. 2. If a read occurs on a present PTE, we will fall in to the "read, present" case and return 1. 3. If a read occurs to a non-present PTE, we will miss the "read, not present" case, because the execute-only VMA will have VM_EXEC set, and we will properly return 0 allowing the PTE to be populated. Test program: int main() { int *p; p = mmap(NULL, 4096, PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); p[0] = 1; return 0; } Reported-by: Andrey Wagin <avagin@gmail.com>, Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Dave Hansen <dave@sr71.net> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-mm@kvack.org Cc: linux-next@vger.kernel.org Fixes: 62b5f7d013fc ("mm/core, x86/mm/pkeys: Add execute-only protection keys support") Link: http://lkml.kernel.org/r/20160301194133.65D0110C@viggo.jf.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | mm/core, x86/mm/pkeys: Add execute-only protection keys supportDave Hansen2016-02-183-0/+113
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Protection keys provide new page-based protection in hardware. But, they have an interesting attribute: they only affect data accesses and never affect instruction fetches. That means that if we set up some memory which is set as "access-disabled" via protection keys, we can still execute from it. This patch uses protection keys to set up mappings to do just that. If a user calls: mmap(..., PROT_EXEC); or mprotect(ptr, sz, PROT_EXEC); (note PROT_EXEC-only without PROT_READ/WRITE), the kernel will notice this, and set a special protection key on the memory. It also sets the appropriate bits in the Protection Keys User Rights (PKRU) register so that the memory becomes unreadable and unwritable. I haven't found any userspace that does this today. With this facility in place, we expect userspace to move to use it eventually. Userspace _could_ start doing this today. Any PROT_EXEC calls get converted to PROT_READ inside the kernel, and would transparently be upgraded to "true" PROT_EXEC with this code. IOW, userspace never has to do any PROT_EXEC runtime detection. This feature provides enhanced protection against leaking executable memory contents. This helps thwart attacks which are attempting to find ROP gadgets on the fly. But, the security provided by this approach is not comprehensive. The PKRU register which controls access permissions is a normal user register writable from unprivileged userspace. An attacker who can execute the 'wrpkru' instruction can easily disable the protection provided by this feature. The protection key that is used for execute-only support is permanently dedicated at compile time. This is fine for now because there is currently no API to set a protection key other than this one. Despite there being a constant PKRU value across the entire system, we do not set it unless this feature is in use in a process. That is to preserve the PKRU XSAVE 'init state', which can lead to faster context switches. PKRU *is* a user register and the kernel is modifying it. That means that code doing: pkru = rdpkru() pkru |= 0x100; mmap(..., PROT_EXEC); wrpkru(pkru); could lose the bits in PKRU that enforce execute-only permissions. To avoid this, we suggest avoiding ever calling mmap() or mprotect() when the PKRU value is expected to be unstable. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Chen Gang <gang.chen.5i5j@gmail.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Dave Hansen <dave@sr71.net> Cc: David Hildenbrand <dahi@linux.vnet.ibm.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Piotr Kwapulinski <kwapulinski.piotr@gmail.com> Cc: Rik van Riel <riel@redhat.com> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: Vladimir Murzin <vladimir.murzin@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: keescook@google.com Cc: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20160212210240.CB4BB5CA@viggo.jf.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | mm/core, x86/mm/pkeys: Differentiate instruction fetchesDave Hansen2016-02-181-2/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As discussed earlier, we attempt to enforce protection keys in software. However, the code checks all faults to ensure that they are not violating protection key permissions. It was assumed that all faults are either write faults where we check PKRU[key].WD (write disable) or read faults where we check the AD (access disable) bit. But, there is a third category of faults for protection keys: instruction faults. Instruction faults never run afoul of protection keys because they do not affect instruction fetches. So, plumb the PF_INSTR bit down in to the arch_vma_access_permitted() function where we do the protection key checks. We also add a new FAULT_FLAG_INSTRUCTION. This is because handle_mm_fault() is not passed the architecture-specific error_code where we keep PF_INSTR, so we need to encode the instruction fetch information in to the arch-generic fault flags. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave@sr71.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20160212210224.96928009@viggo.jf.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | x86/mm/pkeys: Optimize fault handling in access_error()Dave Hansen2016-02-181-0/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We might not strictly have to make modifictions to access_error() to check the VMA here. If we do not, we will do this: 1. app sets VMA pkey to K 2. app touches a !present page 3. do_page_fault(), allocates and maps page, sets pte.pkey=K 4. return to userspace 5. touch instruction reexecutes, but triggers PF_PK 6. do PKEY signal What happens with this patch applied: 1. app sets VMA pkey to K 2. app touches a !present page 3. do_page_fault() notices that K is inaccessible 4. do PKEY signal We basically skip the fault that does an allocation. So what this lets us do is protect areas from even being *populated* unless it is accessible according to protection keys. That seems handy to me and makes protection keys work more like an mprotect()'d mapping. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave@sr71.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20160212210222.EBB63D8C@viggo.jf.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | mm/gup, x86/mm/pkeys: Check VMAs and PTEs for protection keysDave Hansen2016-02-182-1/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Today, for normal faults and page table walks, we check the VMA and/or PTE to ensure that it is compatible with the action. For instance, if we get a write fault on a non-writeable VMA, we SIGSEGV. We try to do the same thing for protection keys. Basically, we try to make sure that if a user does this: mprotect(ptr, size, PROT_NONE); *ptr = foo; they see the same effects with protection keys when they do this: mprotect(ptr, size, PROT_READ|PROT_WRITE); set_pkey(ptr, size, 4); wrpkru(0xffffff3f); // access disable pkey 4 *ptr = foo; The state to do that checking is in the VMA, but we also sometimes have to do it on the page tables only, like when doing a get_user_pages_fast() where we have no VMA. We add two functions and expose them to generic code: arch_pte_access_permitted(pte_flags, write) arch_vma_access_permitted(vma, write) These are, of course, backed up in x86 arch code with checks against the PTE or VMA's protection key. But, there are also cases where we do not want to respect protection keys. When we ptrace(), for instance, we do not want to apply the tracer's PKRU permissions to the PTEs from the process being traced. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Alexey Kardashevskiy <aik@ozlabs.ru> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Boaz Harrosh <boaz@plexistor.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave@sr71.net> Cc: David Gibson <david@gibson.dropbear.id.au> Cc: David Hildenbrand <dahi@linux.vnet.ibm.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Dominik Dingel <dingel@linux.vnet.ibm.com> Cc: Dominik Vogt <vogt@linux.vnet.ibm.com> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jason Low <jason.low2@hp.com> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Laurent Dufour <ldufour@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Matthew Wilcox <willy@linux.intel.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mikulas Patocka <mpatocka@redhat.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Shachar Raindel <raindel@mellanox.com> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: linux-arch@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org Cc: linux-s390@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/20160212210219.14D5D715@viggo.jf.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | x86/mm/gup: Simplify get_user_pages() PTE bit handlingDave Hansen2016-02-181-16/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current get_user_pages() code is a wee bit more complicated than it needs to be for pte bit checking. Currently, it establishes a mask of required pte _PAGE_* bits and ensures that the pte it goes after has all those bits. This consolidates the three identical copies of this code. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave@sr71.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20160212210218.3A2D4045@viggo.jf.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>