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* KVM: x86: Fix load damaged SSEx MXCSR registerWanpeng Li2017-05-151-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Reported by syzkaller: BUG: unable to handle kernel paging request at ffffffffc07f6a2e IP: report_bug+0x94/0x120 PGD 348e12067 P4D 348e12067 PUD 348e14067 PMD 3cbd84067 PTE 80000003f7e87161 Oops: 0003 [#1] SMP CPU: 2 PID: 7091 Comm: kvm_load_guest_ Tainted: G OE 4.11.0+ #8 task: ffff92fdfb525400 task.stack: ffffbda6c3d04000 RIP: 0010:report_bug+0x94/0x120 RSP: 0018:ffffbda6c3d07b20 EFLAGS: 00010202 do_trap+0x156/0x170 do_error_trap+0xa3/0x170 ? kvm_load_guest_fpu.part.175+0x12a/0x170 [kvm] ? mark_held_locks+0x79/0xa0 ? retint_kernel+0x10/0x10 ? trace_hardirqs_off_thunk+0x1a/0x1c do_invalid_op+0x20/0x30 invalid_op+0x1e/0x30 RIP: 0010:kvm_load_guest_fpu.part.175+0x12a/0x170 [kvm] ? kvm_load_guest_fpu.part.175+0x1c/0x170 [kvm] kvm_arch_vcpu_ioctl_run+0xed6/0x1b70 [kvm] kvm_vcpu_ioctl+0x384/0x780 [kvm] ? kvm_vcpu_ioctl+0x384/0x780 [kvm] ? sched_clock+0x13/0x20 ? __do_page_fault+0x2a0/0x550 do_vfs_ioctl+0xa4/0x700 ? up_read+0x1f/0x40 ? __do_page_fault+0x2a0/0x550 SyS_ioctl+0x79/0x90 entry_SYSCALL_64_fastpath+0x23/0xc2 SDM mentioned that "The MXCSR has several reserved bits, and attempting to write a 1 to any of these bits will cause a general-protection exception(#GP) to be generated". The syzkaller forks' testcase overrides xsave area w/ random values and steps on the reserved bits of MXCSR register. The damaged MXCSR register values of guest will be restored to SSEx MXCSR register before vmentry. This patch fixes it by catching userspace override MXCSR register reserved bits w/ random values and bails out immediately. Reported-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
* sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar2017-03-021-0/+1
| | | | | | | | | | | | | | | | | | | | <linux/sched/task_stack.h> We are going to split <linux/sched/task_stack.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/task_stack.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar2017-03-021-0/+1
| | | | | | | | | | | | | | | | | | | | <linux/sched/task.h> We are going to split <linux/sched/task.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/task.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* Merge branch 'x86-fpu-for-linus' of ↵Linus Torvalds2017-02-213-23/+23
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fpu updates from Ingo Molnar: "The main changes relate to fixes between (lack of) CPUID and FPU detection that should only affect old or weird CPUs, by Andy Lutomirski" * 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/fpu: Fix the "Giving up, no FPU found" test x86/fpu: Fix CPUID-less FPU detection x86/fpu: Fix "x86/fpu: Legacy x87 FPU detected" message x86/cpu: Re-apply forced caps every time CPU caps are re-read x86/cpu: Factor out application of forced CPU caps x86/cpu: Add X86_FEATURE_CPUID x86/fpu/xstate: Move XSAVES state init to a function
| * x86/fpu: Fix the "Giving up, no FPU found" testAndy Lutomirski2017-01-251-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We would never print "Giving up, no FPU found" because X86_FEATURE_FPU was in REQUIRED_MASK on non-FPU-emulating builds, so the boot_cpu_has() test didn't do anything. Signed-off-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Borislav Petkov <bp@suse.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matthew Whitehead <tedheadster@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/1499077fa76f0f84b8ea28e37d3fa70beca4e310.1484705016.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * x86/fpu: Fix CPUID-less FPU detectionAndy Lutomirski2017-01-251-13/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The old code didn't work at all because it adjusted the current caps instead of the forced caps. Anything it did would be undone later during CPU identification. Fix that and, while we're at it, improve the logging and don't bother running it if CPUID is available. Reported-by: Matthew Whitehead <tedheadster@gmail.com> Signed-off-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Borislav Petkov <bp@suse.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/f1134e30cafa73c4e2e68119e9741793622cfd15.1484705016.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * x86/fpu: Fix "x86/fpu: Legacy x87 FPU detected" messageAndy Lutomirski2017-01-251-1/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | That message isn't at all clear -- what does "Legacy x87" even mean? Clarify it. If there's no FPU, say: x86/fpu: No FPU detected If there's an FPU that doesn't have XSAVE, say: x86/fpu: x87 FPU will use FSAVE|FXSAVE Signed-off-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Borislav Petkov <bp@suse.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matthew Whitehead <tedheadster@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/bb839385e18e27bca23fe8666dfdad8170473045.1484705016.git.luto@kernel.org [ Small tweaks to the messages. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * x86/fpu/xstate: Move XSAVES state init to a functionYu-cheng Yu2017-01-251-8/+1Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make XSTATE init similar to existing code; move it to a separate function. There is no functionality change. Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ravi V. Shankar <ravi.v.shankar@intel.com> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1485282346-15437-1-git-send-email-yu-cheng.yu@intel.com [ Minor cleanliness edits. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | Merge branch 'x86-cpufeature-for-linus' of ↵Linus Torvalds2017-02-201-0/+1
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 cpufeature updates from Ingo Molnar: "The main changes in this cycle were related to enable ring-3 MONITOR/MWAIT instructions support on supported CPUs, by Grzegorz Andrejczuk and Piotr Luc" * 'x86-cpufeature-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/cpufeature: Move RING3MWAIT feature to avoid conflicts x86/cpufeature: Enable RING3MWAIT for Knights Mill x86/cpufeature: Enable RING3MWAIT for Knights Landing x86/cpufeature: Add RING3MWAIT to CPU features x86/elf: Add HWCAP2 to expose ring 3 MONITOR/MWAIT x86/msr: Add MSR_MISC_FEATURE_ENABLES and RING3MWAIT bit x86/cpufeature: Add AVX512_VPOPCNTDQ feature
| * x86/cpufeature: Add AVX512_VPOPCNTDQ featurePiotr Luc2017-01-161-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Vector population count instructions for dwords and qwords are going to be available in future Intel Xeon & Xeon Phi processors. Bit 14 of CPUID[level:0x07, ECX] indicates that the instructions are supported by a processor. The specification can be found in the Intel Software Developer Manual (SDM) and in the Instruction Set Extensions Programming Reference (ISE). Populate the feature bit and clear it when xsave is disabled. Signed-off-by: Piotr Luc <piotr.luc@intel.com> Reviewed-by: Borislav Petkov <bp@suse.de> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: kvm@vger.kernel.org Cc: Radim Krčmář <rkrcmar@redhat.com> Link: http://lkml.kernel.org/r/20170110173403.6010-2-piotr.luc@intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | x86/fpu/xstate: Fix xcomp_bv in XSAVES headerYu-cheng Yu2017-01-242-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The compacted-format XSAVES area is determined at boot time and never changed after. The field xsave.header.xcomp_bv indicates which components are in the fixed XSAVES format. In fpstate_init() we did not set xcomp_bv to reflect the XSAVES format since at the time there is no valid data. However, after we do copy_init_fpstate_to_fpregs() in fpu__clear(), as in commit: b22cbe404a9c x86/fpu: Fix invalid FPU ptrace state after execve() and when __fpu_restore_sig() does fpu__restore() for a COMPAT-mode app, a #GP occurs. This can be easily triggered by doing valgrind on a COMPAT-mode "Hello World," as reported by Joakim Tjernlund and others: https://bugzilla.kernel.org/show_bug.cgi?id=190061 Fix it by setting xcomp_bv correctly. This patch also moves the xcomp_bv initialization to the proper place, which was in copyin_to_xsaves() as of: 4c833368f0bf x86/fpu: Set the xcomp_bv when we fake up a XSAVES area which fixed the bug too, but it's more efficient and cleaner to initialize things once per boot, not for every signal handling operation. Reported-by: Kevin Hao <haokexin@gmail.com> Reported-by: Joakim Tjernlund <Joakim.Tjernlund@infinera.com> Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@suse.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ravi V. Shankar <ravi.v.shankar@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: haokexin@gmail.com Link: http://lkml.kernel.org/r/1485212084-4418-1-git-send-email-yu-cheng.yu@intel.com [ Combined it with 4c833368f0bf. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | x86/fpu: Set the xcomp_bv when we fake up a XSAVES areaKevin Hao2017-01-231-0/+1
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I got the following calltrace on a Apollo Lake SoC with 32-bit kernel: WARNING: CPU: 2 PID: 261 at arch/x86/include/asm/fpu/internal.h:363 fpu__restore+0x1f5/0x260 [...] Hardware name: Intel Corp. Broxton P/NOTEBOOK, BIOS APLIRVPA.X64.0138.B35.1608091058 08/09/2016 Call Trace: dump_stack() __warn() ? fpu__restore() warn_slowpath_null() fpu__restore() __fpu__restore_sig() fpu__restore_sig() restore_sigcontext.isra.9() sys_sigreturn() do_int80_syscall_32() entry_INT80_32() The reason is that a #GP occurs when executing XRSTORS. The root cause is that we forget to set the xcomp_bv when we fake up the XSAVES area in the copyin_to_xsaves() function. Signed-off-by: Kevin Hao <haokexin@gmail.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/1485075023-30161-1-git-send-email-haokexin@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* Merge branch 'x86-fpu-for-linus' of ↵Linus Torvalds2016-12-125-193/+12Star
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 FPU updates from Ingo Molnar: "The main changes in this cycle were: - do a large round of simplifications after all CPUs do 'eager' FPU context switching in v4.9: remove CR0 twiddling, remove leftover eager/lazy bts, etc (Andy Lutomirski) - more FPU code simplifications: remove struct fpu::counter, clarify nomenclature, remove unnecessary arguments/functions and better structure the code (Rik van Riel)" * 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/fpu: Remove clts() x86/fpu: Remove stts() x86/fpu: Handle #NM without FPU emulation as an error x86/fpu, lguest: Remove CR0.TS support x86/fpu, kvm: Remove host CR0.TS manipulation x86/fpu: Remove irq_ts_save() and irq_ts_restore() x86/fpu: Stop saving and restoring CR0.TS in fpu__init_check_bugs() x86/fpu: Get rid of two redundant clts() calls x86/fpu: Finish excising 'eagerfpu' x86/fpu: Split old_fpu & new_fpu handling into separate functions x86/fpu: Remove 'cpu' argument from __cpu_invalidate_fpregs_state() x86/fpu: Split old & new FPU code paths x86/fpu: Remove __fpregs_(de)activate() x86/fpu: Rename lazy restore functions to "register state valid" x86/fpu, kvm: Remove KVM vcpu->fpu_counter x86/fpu: Remove struct fpu::counter x86/fpu: Remove use_eager_fpu() x86/fpu: Remove the XFEATURE_MASK_EAGER/LAZY distinction x86/fpu: Hard-disable lazy FPU mode x86/crypto, x86/fpu: Remove X86_FEATURE_EAGER_FPU #ifdef from the crc32c code
| * Merge branch 'linus' into x86/fpu, to resolve conflictsIngo Molnar2016-11-231-8/+8
| |\ | | | | | | | | | | | | | | | | | | Conflicts: arch/x86/kernel/fpu/core.c Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | x86/fpu: Remove irq_ts_save() and irq_ts_restore()Andy Lutomirski2016-11-011-29/+0Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that lazy FPU is gone, we don't use CR0.TS (except possibly in KVM guest mode). Remove irq_ts_save(), irq_ts_restore(), and all of their callers. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Rik van Riel <riel@redhat.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kvm list <kvm@vger.kernel.org> Link: http://lkml.kernel.org/r/70b9b9e7ba70659bedcb08aba63d0f9214f338f2.1477951965.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | x86/fpu: Stop saving and restoring CR0.TS in fpu__init_check_bugs()Andy Lutomirski2016-11-011-7/+0Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | fpu__init_check_bugs() runs long after the early FPU init, so CR0.TS will be clear by the time it runs. The save-and-restore dance would have been unnecessary anyway, though, as kernel_fpu_begin() would have been good enough. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Rik van Riel <riel@redhat.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kvm list <kvm@vger.kernel.org> Link: http://lkml.kernel.org/r/76d1f1eacb5caead98197d1eb50ac6110ab20c6a.1477951965.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | x86/fpu: Get rid of two redundant clts() callsAndy Lutomirski2016-11-011-18/+0Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | CR0.TS is cleared by a direct CR0 write in fpu__init_cpu_generic(). We don't need to call clts() two more times right after that. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Rik van Riel <riel@redhat.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kvm list <kvm@vger.kernel.org> Link: http://lkml.kernel.org/r/476d2d5066eda24838853426ea74c94140b50c85.1477951965.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | Merge branch 'core/urgent' into x86/fpu, to merge fixesIngo Molnar2016-11-011-0/+2
| |\ \ | | | | | | | | | | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * \ \ Merge tag 'v4.9-rc1' into x86/fpu, to resolve conflictIngo Molnar2016-10-162-1/+8
| |\ \ \ | | | | | | | | | | | | | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | x86/fpu: Remove 'cpu' argument from __cpu_invalidate_fpregs_state()Rik van Riel2016-10-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The __{fpu,cpu}_invalidate_fpregs_state() functions can only be used to invalidate a resource they control. Document that, and change the API a little bit to reflect that. Go back to open coding the fpu_fpregs_owner_ctx write in the CPU hotplug code, which should be the exception, and move __kernel_fpu_begin() to this API. This patch has no functional changes to the current code. Signed-off-by: Rik van Riel <riel@redhat.com> Acked-by: Dave Hansen <dave.hansen@intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1476447331-21566-2-git-send-email-riel@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | x86/fpu: Rename lazy restore functions to "register state valid"Rik van Riel2016-10-071-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Name the functions after the state they track, rather than the function they currently enable. This should make it more obvious when we use the fpu_register_state_valid() function for something else in the future. Signed-off-by: Rik van Riel <riel@redhat.com> Reviewed-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: pbonzini@redhat.com Link: http://lkml.kernel.org/r/1475627678-20788-8-git-send-email-riel@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | x86/fpu: Remove struct fpu::counterRik van Riel2016-10-071-3/+0Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With the lazy FPU code gone, we no longer use the counter field in struct fpu for anything. Get rid it. Signed-off-by: Rik van Riel <riel@redhat.com> Reviewed-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: pbonzini@redhat.com Link: http://lkml.kernel.org/r/1475627678-20788-6-git-send-email-riel@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | x86/fpu: Remove use_eager_fpu()Andy Lutomirski2016-10-073-47/+8Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This removes all the obvious code paths that depend on lazy FPU mode. It shouldn't change the generated code at all. Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Rik van Riel <riel@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: pbonzini@redhat.com Link: http://lkml.kernel.org/r/1475627678-20788-5-git-send-email-riel@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | x86/fpu: Hard-disable lazy FPU modeAndy Lutomirski2016-10-071-88/+3Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since commit: 58122bf1d856 ("x86/fpu: Default eagerfpu=on on all CPUs") ... in Linux 4.6, eager FPU mode has been the default on all x86 systems, and no one has reported any regressions. This patch removes the ability to enable lazy mode: use_eager_fpu() becomes "return true" and all of the FPU mode selection machinery is removed. Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Rik van Riel <riel@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: pbonzini@redhat.com Link: http://lkml.kernel.org/r/1475627678-20788-3-git-send-email-riel@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | | Merge branch 'x86-asm-for-linus' of ↵Linus Torvalds2016-12-121-0/+2
|\ \ \ \ \ | |_|_|_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 asm updates from Ingo Molnar: "The main changes in this development cycle were: - a large number of call stack dumping/printing improvements: higher robustness, better cross-context dumping, improved output, etc. (Josh Poimboeuf) - vDSO getcpu() performance improvement for future Intel CPUs with the RDPID instruction (Andy Lutomirski) - add two new Intel AVX512 features and the CPUID support infrastructure for it: AVX512IFMA and AVX512VBMI. (Gayatri Kammela, He Chen) - more copy-user unification (Borislav Petkov) - entry code assembly macro simplifications (Alexander Kuleshov) - vDSO C/R support improvements (Dmitry Safonov) - misc fixes and cleanups (Borislav Petkov, Paul Bolle)" * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits) scripts/decode_stacktrace.sh: Fix address line detection on x86 x86/boot/64: Use defines for page size x86/dumpstack: Make stack name tags more comprehensible selftests/x86: Add test_vdso to test getcpu() x86/vdso: Use RDPID in preference to LSL when available x86/dumpstack: Handle NULL stack pointer in show_trace_log_lvl() x86/cpufeatures: Enable new AVX512 cpu features x86/cpuid: Provide get_scattered_cpuid_leaf() x86/cpuid: Cleanup cpuid_regs definitions x86/copy_user: Unify the code by removing the 64-bit asm _copy_*_user() variants x86/unwind: Ensure stack grows down x86/vdso: Set vDSO pointer only after success x86/prctl/uapi: Remove #ifdef for CHECKPOINT_RESTORE x86/unwind: Detect bad stack return address x86/dumpstack: Warn on stack recursion x86/unwind: Warn on bad frame pointer x86/decoder: Use stderr if insn sanity test fails x86/decoder: Use stdout if insn decoder test is successful mm/page_alloc: Remove kernel address exposure in free_reserved_area() x86/dumpstack: Remove raw stack dump ...
| * | | | x86/cpufeatures: Enable new AVX512 cpu featuresGayatri Kammela2016-11-171-0/+2
| | |_|/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a few new AVX512 instruction groups/features for enumeration in /proc/cpuinfo: AVX512IFMA and AVX512VBMI. Clear the flags in fpu_xstate_clear_all_cpu_caps(). CPUID.(EAX=7,ECX=0):EBX[bit 21] AVX512IFMA CPUID.(EAX=7,ECX=0):ECX[bit 1] AVX512VBMI Detailed information of cpuid bits for the features can be found at https://bugzilla.kernel.org/show_bug.cgi?id=187891 Signed-off-by: Gayatri Kammela <gayatri.kammela@intel.com> Reviewed-by: Borislav Petkov <bp@alien8.de> Cc: Ravi Shankar <ravi.v.shankar@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: mingo@elte.hu Link: http://lkml.kernel.org/r/1479327060-18668-1-git-send-email-gayatri.kammela@intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* / | | x86/fpu: Fix invalid FPU ptrace state after execve()Yu-cheng Yu2016-11-211-8/+8
|/ / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Robert O'Callahan reported that after an execve PTRACE_GETREGSET NT_X86_XSTATE continues to return the pre-exec register values until the exec'ed task modifies FPU state. The test code is at: https://bugzilla.redhat.com/attachment.cgi?id=1164286. What is happening is fpu__clear() does not properly clear fpstate. Fix it by doing just that. Reported-by: Robert O'Callahan <robert@ocallahan.org> Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Cc: <stable@vger.kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@suse.de> Cc: David Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ravi V. Shankar <ravi.v.shankar@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1479402695-6553-1-git-send-email-yu-cheng.yu@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | / x86/cpufeature: Add AVX512_4VNNIW and AVX512_4FMAPS featuresPiotr Luc2016-10-191-0/+2
| |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | AVX512_4VNNIW - Vector instructions for deep learning enhanced word variable precision. AVX512_4FMAPS - Vector instructions for deep learning floating-point single precision. These new instructions are to be used in future Intel Xeon & Xeon Phi processors. The bits 2&3 of CPUID[level:0x07, EDX] inform that new instructions are supported by a processor. The spec can be found in the Intel Software Developer Manual (SDM) or in the Instruction Set Extensions Programming Reference (ISE). Define new feature flags to enumerate the new instructions in /proc/cpuinfo accordingly to CPUID bits and add the required xsave extensions which are required for proper operation. Signed-off-by: Piotr Luc <piotr.luc@intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20161018150111.29926-1-piotr.luc@intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | Merge branch 'mm-pkeys-for-linus' of ↵Linus Torvalds2016-10-102-1/+8
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull protection keys syscall interface from Thomas Gleixner: "This is the final step of Protection Keys support which adds the syscalls so user space can actually allocate keys and protect memory areas with them. Details and usage examples can be found in the documentation. The mm side of this has been acked by Mel" * 'mm-pkeys-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/pkeys: Update documentation x86/mm/pkeys: Do not skip PKRU register if debug registers are not used x86/pkeys: Fix pkeys build breakage for some non-x86 arches x86/pkeys: Add self-tests x86/pkeys: Allow configuration of init_pkru x86/pkeys: Default to a restrictive init PKRU pkeys: Add details of system call use to Documentation/ generic syscalls: Wire up memory protection keys syscalls x86: Wire up protection keys system calls x86/pkeys: Allocation/free syscalls x86/pkeys: Make mprotect_key() mask off additional vm_flags mm: Implement new pkey_mprotect() system call x86/pkeys: Add fault handling for PF_PK page fault bit
| * x86/pkeys: Default to a restrictive init PKRUDave Hansen2016-09-091-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | PKRU is the register that lets you disallow writes or all access to a given protection key. The XSAVE hardware defines an "init state" of 0 for PKRU: its most permissive state, allowing access/writes to everything. Since we start off all new processes with the init state, we start all processes off with the most permissive possible PKRU. This is unfortunate. If a thread is clone()'d [1] before a program has time to set PKRU to a restrictive value, that thread will be able to write to all data, no matter what pkey is set on it. This weakens any integrity guarantees that we want pkeys to provide. To fix this, we define a very restrictive PKRU to override the XSAVE-provided value when we create a new FPU context. We choose a value that only allows access to pkey 0, which is as restrictive as we can practically make it. This does not cause any practical problems with applications using protection keys because we require them to specify initial permissions for each key when it is allocated, which override the restrictive default. In the end, this ensures that threads which do not know how to manage their own pkey rights can not do damage to data which is pkey-protected. I would have thought this was a pretty contrived scenario, except that I heard a bug report from an MPX user who was creating threads in some very early code before main(). It may be crazy, but folks evidently _do_ it. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: linux-arch@vger.kernel.org Cc: Dave Hansen <dave@sr71.net> Cc: mgorman@techsingularity.net Cc: arnd@arndb.de Cc: linux-api@vger.kernel.org Cc: linux-mm@kvack.org Cc: luto@kernel.org Cc: akpm@linux-foundation.org Cc: torvalds@linux-foundation.org Link: http://lkml.kernel.org/r/20160729163021.F3C25D4A@viggo.jf.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * x86/pkeys: Allocation/free syscallsDave Hansen2016-09-091-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds two new system calls: int pkey_alloc(unsigned long flags, unsigned long init_access_rights) int pkey_free(int pkey); These implement an "allocator" for the protection keys themselves, which can be thought of as analogous to the allocator that the kernel has for file descriptors. The kernel tracks which numbers are in use, and only allows operations on keys that are valid. A key which was not obtained by pkey_alloc() may not, for instance, be passed to pkey_mprotect(). These system calls are also very important given the kernel's use of pkeys to implement execute-only support. These help ensure that userspace can never assume that it has control of a key unless it first asks the kernel. The kernel does not promise to preserve PKRU (right register) contents except for allocated pkeys. The 'init_access_rights' argument to pkey_alloc() specifies the rights that will be established for the returned pkey. For instance: pkey = pkey_alloc(flags, PKEY_DENY_WRITE); will allocate 'pkey', but also sets the bits in PKRU[1] such that writing to 'pkey' is already denied. The kernel does not prevent pkey_free() from successfully freeing in-use pkeys (those still assigned to a memory range by pkey_mprotect()). It would be expensive to implement the checks for this, so we instead say, "Just don't do it" since sane software will never do it anyway. Any piece of userspace calling pkey_alloc() needs to be prepared for it to fail. Why? pkey_alloc() returns the same error code (ENOSPC) when there are no pkeys and when pkeys are unsupported. They can be unsupported for a whole host of reasons, so apps must be prepared for this. Also, libraries or LD_PRELOADs might steal keys before an application gets access to them. This allocation mechanism could be implemented in userspace. Even if we did it in userspace, we would still need additional user/kernel interfaces to tell userspace which keys are being used by the kernel internally (such as for execute-only mappings). Having the kernel provide this facility completely removes the need for these additional interfaces, or having an implementation of this in userspace at all. Note that we have to make changes to all of the architectures that do not use mman-common.h because we use the new PKEY_DENY_ACCESS/WRITE macros in arch-independent code. 1. PKRU is the Protection Key Rights User register. It is a usermode-accessible register that controls whether writes and/or access to each individual pkey is allowed or denied. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: linux-arch@vger.kernel.org Cc: Dave Hansen <dave@sr71.net> Cc: arnd@arndb.de Cc: linux-api@vger.kernel.org Cc: linux-mm@kvack.org Cc: luto@kernel.org Cc: akpm@linux-foundation.org Cc: torvalds@linux-foundation.org Link: http://lkml.kernel.org/r/20160729163015.444FE75F@viggo.jf.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | x86/asm: Move the thread_info::status field to thread_structAndy Lutomirski2016-09-151-1/+0Star
|/ | | | | | | | | | | | | | | | | | | | Because sched.h and thread_info.h are a tangled mess, I turned in_compat_syscall() into a macro. If we had current_thread_struct() or similar and we could use it from thread_info.h, then this would be a bit cleaner. Signed-off-by: Andy Lutomirski <luto@kernel.org> 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: Jann Horn <jann@thejh.net> 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> Link: http://lkml.kernel.org/r/ccc8a1b2f41f9c264a41f771bb4a6539a642ad72.1473801993.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/mm/pkeys: Fix compact mode by removing protection keys' XSAVE buffer ↵Dave Hansen2016-08-101-121/+17Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | manipulation The Memory Protection Keys "rights register" (PKRU) is XSAVE-managed, and is saved/restored along with the FPU state. When kernel code accesses FPU regsisters, it does a delicate dance with preempt. Otherwise, the context switching code can get confused as to whether the most up-to-date state is in the registers themselves or in the XSAVE buffer. But, PKRU is not a normal FPU register. Using it does not generate the normal device-not-available (#NM) exceptions which means we can not manage it lazily, and the kernel completley disallows using lazy mode when it is enabled. The dance with preempt *only* occurs when managing the FPU lazily. Since we never manage PKRU lazily, we do not have to do the dance with preempt; we can access it directly. Doing it this way saves a ton of complicated code (and is faster too). Further, the XSAVES reenabling failed to patch a bit of code in fpu__xfeature_set_state() the checked for compacted buffers. That check caused fpu__xfeature_set_state() to silently refuse to work when the kernel is using compacted XSAVE buffers. This broke execute-only and future pkey_mprotect() support when using compact XSAVE buffers. But, removing fpu__xfeature_set_state() gets rid of this issue, in addition to the nice cleanup and speedup. This fixes the same thing as a fix that Sai posted: https://lkml.org/lkml/2016/7/25/637 The fix that he posted is a much more obviously correct, but I think we should just do this instead. Reported-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Dave Hansen <dave@sr71.net> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Ravi Shankar <ravi.v.shankar@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yu-Cheng Yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/20160727232040.7D060DAD@viggo.jf.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* tree-wide: replace config_enabled() with IS_ENABLED()Masahiro Yamada2016-08-041-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The use of config_enabled() against config options is ambiguous. In practical terms, config_enabled() is equivalent to IS_BUILTIN(), but the author might have used it for the meaning of IS_ENABLED(). Using IS_ENABLED(), IS_BUILTIN(), IS_MODULE() etc. makes the intention clearer. This commit replaces config_enabled() with IS_ENABLED() where possible. This commit is only touching bool config options. I noticed two cases where config_enabled() is used against a tristate option: - config_enabled(CONFIG_HWMON) [ drivers/net/wireless/ath/ath10k/thermal.c ] - config_enabled(CONFIG_BACKLIGHT_CLASS_DEVICE) [ drivers/gpu/drm/gma500/opregion.c ] I did not touch them because they should be converted to IS_BUILTIN() in order to keep the logic, but I was not sure it was the authors' intention. Link: http://lkml.kernel.org/r/1465215656-20569-1-git-send-email-yamada.masahiro@socionext.com Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Stas Sergeev <stsp@list.ru> Cc: Matt Redfearn <matt.redfearn@imgtec.com> Cc: Joshua Kinard <kumba@gentoo.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Borislav Petkov <bp@suse.de> Cc: Markos Chandras <markos.chandras@imgtec.com> Cc: "Dmitry V. Levin" <ldv@altlinux.org> Cc: yu-cheng yu <yu-cheng.yu@intel.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Brian Gerst <brgerst@gmail.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Will Drewry <wad@chromium.org> Cc: Nikolay Martynov <mar.kolya@gmail.com> Cc: Huacai Chen <chenhc@lemote.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com> Cc: Rafal Milecki <zajec5@gmail.com> Cc: James Cowgill <James.Cowgill@imgtec.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Alex Smith <alex.smith@imgtec.com> Cc: Adam Buchbinder <adam.buchbinder@gmail.com> Cc: Qais Yousef <qais.yousef@imgtec.com> Cc: Jiang Liu <jiang.liu@linux.intel.com> Cc: Mikko Rapeli <mikko.rapeli@iki.fi> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Brian Norris <computersforpeace@gmail.com> Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Cc: "Luis R. Rodriguez" <mcgrof@do-not-panic.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Ingo Molnar <mingo@redhat.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Roland McGrath <roland@hack.frob.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Kalle Valo <kvalo@qca.qualcomm.com> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Tony Wu <tung7970@gmail.com> Cc: Huaitong Han <huaitong.han@intel.com> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Juergen Gross <jgross@suse.com> Cc: Jason Cooper <jason@lakedaemon.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andrea Gelmini <andrea.gelmini@gelma.net> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Rabin Vincent <rabin@rab.in> Cc: "Maciej W. Rozycki" <macro@imgtec.com> Cc: David Daney <david.daney@cavium.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* x86/fpu: Do not BUG_ON() in early FPU codeDave Hansen2016-07-211-6/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I don't think it is really possible to have a system where CPUID enumerates support for XSAVE but that it does not have FP/SSE (they are "legacy" features and always present). But, I did manage to hit this case in qemu when I enabled its somewhat shaky XSAVE support. The bummer is that the FPU is set up before we parse the command-line or have *any* console support including earlyprintk. That turned what should have been an easy thing to debug in to a bit more of an odyssey. So a BUG() here is worthless. All it does it guarantee that if/when we hit this case we have an empty console. So, remove the BUG() and try to limp along by disabling XSAVE and trying to continue. Add a comment on why we are doing this, and also add a common "out_disable" path for leaving fpu__init_system_xstate(). Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> 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: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20160720194551.63BB2B58@viggo.jf.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu/xstate: Re-enable XSAVESYu-cheng Yu2016-07-112-15/+9Star
| | | | | | | | | | | | | | | | | | | | We did not handle XSAVES instructions correctly. There were issues in converting between standard and compacted format when interfacing with user-space. These issues have been corrected. Add a WARN_ONCE() to make it clear that XSAVES supervisor states are not yet implemented. Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Cc: H. Peter Anvin <h.peter.anvin@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ravi V Shankar <ravi.v.shankar@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1468253937-40008-5-git-send-email-fenghua.yu@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu/xstate: Fix fpstate_init() for XRSTORSYu-cheng Yu2016-07-111-0/+8
| | | | | | | | | | | | | | | | | | | | | | | In XSAVES mode if fpstate_init() is used to initialize a task's extended state area, xsave.header.xcomp_bv[63] must be set. Otherwise, when the task is scheduled, a warning is triggered from copy_kernel_to_xregs(). One such test case is: setting an invalid extended state through PTRACE. When xstateregs_set() rejects the syscall and re-initializes the task's extended state area. This triggers the warning mentioned above. Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Cc: H. Peter Anvin <h.peter.anvin@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ravi V Shankar <ravi.v.shankar@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1468253937-40008-4-git-send-email-fenghua.yu@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu/xstate: Return NULL for disabled xstate component addressYu-cheng Yu2016-07-111-0/+5
| | | | | | | | | | | | | | | | | It is an error to request a disabled XSAVE/XSAVES component address. For that case, make __raw_xsave_addr() return a NULL and issue a warning. Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Cc: H. Peter Anvin <h.peter.anvin@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ravi V Shankar <ravi.v.shankar@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1468253937-40008-3-git-send-email-fenghua.yu@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu/xstate: Fix __fpu_restore_sig() for XSAVESYu-cheng Yu2016-07-111-2/+9
| | | | | | | | | | | | | | | | | | | When the kernel is using XSAVES compacted format, we cannot do __copy_from_user() from a signal frame, which has standard-format data. Fix it by using copyin_to_xsaves(), which converts between formats and filters out all supervisor states that we do not allow userspace to write. Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Cc: H. Peter Anvin <h.peter.anvin@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ravi V Shankar <ravi.v.shankar@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1468253937-40008-2-git-send-email-fenghua.yu@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu/xstate: Fix xstate_offsets, xstate_sizes for non-extended xstatesYu-cheng Yu2016-07-101-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | The arrays xstate_offsets[] and xstate_sizes[] record XSAVE standard- format offsets and sizes. Values for non-extended state components fpu and xmm's were not initialized or used. Ptrace format conversion needs them. Fix it. Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Ravi V. Shankar <ravi.v.shankar@intel.com> Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/cf3ea36cf30e2a99e37da6483e65446d018ff0a7.1466179491.git.yu-cheng.yu@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu/xstate: Fix XSTATE component offset print outYu-cheng Yu2016-07-101-2/+16
| | | | | | | | | | | | | | | | | | | | | | | | | Component offset print out was incorrect for XSAVES. Correct it and move to a separate function. Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Ravi V. Shankar <ravi.v.shankar@intel.com> Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/86602a8ac400626c6eca7125c3e15934866fc38e.1466179491.git.yu-cheng.yu@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu/xstate: Fix PTRACE frames for XSAVESYu-cheng Yu2016-07-102-23/+212
| | | | | | | | | | | | | | | | | | | | | | | | | | | XSAVES uses compacted format and is a kernel instruction. The kernel should use standard-format, non-supervisor state data for PTRACE. Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> [ Edited away artificial linebreaks. ] Reviewed-by: Dave Hansen <dave.hansen@intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Ravi V. Shankar <ravi.v.shankar@intel.com> Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/de3d80949001305fe389799973b675cab055c457.1466179491.git.yu-cheng.yu@intel.com [ Made various readability edits. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu/xstate: Fix supervisor xstate component offsetYu-cheng Yu2016-07-101-23/+39
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | CPUID function 0x0d, sub function (i, i > 1) returns in ebx the offset of xstate component i. Zero is returned for a supervisor state. A supervisor state can only be saved by XSAVES and XSAVES uses a compacted format. There is no fixed offset for a supervisor state. This patch checks and makes sure a supervisor state offset is not recorded or mis-used. This has no effect in practice as we currently use no supervisor states, but it would be good to fix. Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Ravi V. Shankar <ravi.v.shankar@intel.com> Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/81b29e40d35d4cec9f2511a856fe769f34935a3f.1466179491.git.yu-cheng.yu@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu/xstate: Align xstate components according to CPUIDYu-cheng Yu2016-07-101-28/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | CPUID function 0x0d, sub function (i, i > 1) returns in ecx[1] the alignment requirement of component 'i' when the compacted format is used. If ecx[1] is 0, component 'i' is located immediately following the preceding component. If ecx[1] is 1, component 'i' is located on the next 64-byte boundary following the preceding component. Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Ravi V. Shankar <ravi.v.shankar@intel.com> Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/331e2bef1a0a7a584f06adde095b6bbfbe166472.1466179491.git.yu-cheng.yu@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu/xstate: Copy xstate registers directly to the signal frame when ↵Yu-cheng Yu2016-06-182-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | compacted format is in use XSAVES is a kernel instruction and uses a compacted format. When working with user space, the kernel should provide standard-format, non-supervisor state data. We cannot do __copy_to_user() from a compacted-format kernel xstate area to a signal frame. Dave Hansen proposes this method to simplify copy xstate directly to user. This patch is based on an earlier patch from Fenghua Yu <fenghua.yu@intel.com> Originally-from: Fenghua Yu <fenghua.yu@intel.com> Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Ravi V. Shankar <ravi.v.shankar@intel.com> Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/c36f419d525517d04209a28dd8e1e5af9000036e.1463760376.git.yu-cheng.yu@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu/xstate: Keep init_fpstate.xsave.header.xfeatures as zero for init ↵Fenghua Yu2016-06-181-4/+2Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | optimization Keep init_fpstate.xsave.header.xfeatures as zero for init optimization. This is important for init optimization that is implemented in processor. If a bit corresponding to an xstate in xstate_bv is 0, it means the xstate is in init status and will not be read from memory to the processor during XRSTOR/XRSTORS instruction. This largely impacts context switch performance. Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Ravi V. Shankar <ravi.v.shankar@intel.com> Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/2fb4ec7f18b76e8cda057a8c0038def74a9b8044.1463760376.git.yu-cheng.yu@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu/xstate: Rename 'xstate_size' to 'fpu_kernel_xstate_size', to ↵Fenghua Yu2016-06-184-17/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | distinguish it from 'fpu_user_xstate_size' User space uses standard format xsave area. fpstate in signal frame should have standard format size. To explicitly distinguish between xstate size in kernel space and the one in user space, we rename 'xstate_size' to 'fpu_kernel_xstate_size'. Cleanup only, no change in functionality. Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> [ Rebased the patch and cleaned up the naming. ] Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Ravi V. Shankar <ravi.v.shankar@intel.com> Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/2ecbae347a5152d94be52adf7d0f3b7305d90d99.1463760376.git.yu-cheng.yu@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu/xstate: Define and use 'fpu_user_xstate_size'Fenghua Yu2016-06-183-36/+72
| | | | | | | | | | | | | | | | | | | | | | | | | | | The kernel xstate area can be in standard or compacted format; it is always in standard format for user mode. When XSAVES is enabled, the kernel uses the compacted format and it is necessary to use a separate fpu_user_xstate_size for signal/ptrace frames. Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> [ Rebased the patch and cleaned up the naming. ] Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Ravi V. Shankar <ravi.v.shankar@intel.com> Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/8756ec34dabddfc727cda5743195eb81e8caf91c.1463760376.git.yu-cheng.yu@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu: Add tracepoints to dump FPU state at key pointsDave Hansen2016-06-082-0/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I've been carrying this patch around for a bit and it's helped me solve at least a couple FPU-related bugs. In addition to using it for debugging, I also drug it out because using AVX (and AVX2/AVX-512) can have serious power consequences for a modern core. It's very important to be able to figure out who is using it. It's also insanely useful to go out and see who is using a given feature, like MPX or Memory Protection Keys. If you, for instance, want to find all processes using protection keys, you can do: echo 'xfeatures & 0x200' > filter Since 0x200 is the protection keys feature bit. Note that this touches the KVM code. KVM did a CREATE_TRACE_POINTS and then included a bunch of random headers. If anyone one of those included other tracepoints, it would have defined the *OTHER* tracepoints. That's bogus, so move it to the right place. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> 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: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20160601174220.3CDFB90E@viggo.jf.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu: Get rid of x87 math exception helpersBorislav Petkov2016-04-131-31/+13Star
| | | | | | | | | | | | | | | | | | | ... and integrate their functionality into their single user fpu__exception_code(). No functionality change. Signed-off-by: Borislav Petkov <bp@suse.de> 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/1459837795-2588-7-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
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