From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755341AbaJXW6Y (ORCPT ); Fri, 24 Oct 2014 18:58:24 -0400 Received: from mail-pa0-f49.google.com ([209.85.220.49]:32950 "EHLO mail-pa0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752524AbaJXW6W (ORCPT ); Fri, 24 Oct 2014 18:58:22 -0400 From: Andy Lutomirski To: Peter Zijlstra Cc: Valdis Kletnieks , "linux-kernel@vger.kernel.org" , Paul Mackerras , Arnaldo Carvalho de Melo , Ingo Molnar , Kees Cook , Andrea Arcangeli , Vince Weaver , "hillf.zj" , Andy Lutomirski Subject: [PATCH v2 0/8] CR4 handling improvements Date: Fri, 24 Oct 2014 15:58:05 -0700 Message-Id: X-Mailer: git-send-email 1.9.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This little series tightens up rdpmc permissions. With it applied, rdpmc can only be used if a perf_event is actually mmapped. For now, this is only really useful for seccomp. At some point this could be further tightened up to only allow rdpmc if an actual self-monitoring perf event that is compatible with rdpmc is mapped. This should add <50ns to context switches between rdpmc-capable and rdpmc-non-capable mms. I suspect that this is well under 10% overhead, given that perf already adds some context switch latency. I think that patches 1-3 are a good idea regardless of any rdpmc changes. AMD Uncore userspace rdpmc is broken by these patches (cap_user_rdpmc will be zero), but it was broken anyway. Changes from v1 (aka RFC): - Rebased on top of the KVM CR4 fix. This applies to a very recent -linus. - Renamed the cr4 helpers (Peter, Borislav) - Fixed buggy cr4 helpers (Hilf) - Improved lots of comments (everyone) - Renamed read_cr4 and write_cr4 to make sure I didn't miss anything. (NB: This will introduce conflicts with Andi's FSGSBASE work. This is a good thing.) Andy Lutomirski (7): x86: Clean up cr4 manipulation x86: Store a per-cpu shadow copy of CR4 x86: Add a comment clarifying LDT context switching perf: Add pmu callbacks to track event mapping and unmapping perf: Pass the event to arch_perf_update_userpage x86, perf: Only allow rdpmc if a perf_event is mapped x86, perf: Add /sys/devices/cpu/rdpmc=2 to allow rdpmc for all tasks Peter Zijlstra (1): perf: Clean up pmu::event_idx arch/powerpc/perf/hv-24x7.c | 6 --- arch/powerpc/perf/hv-gpci.c | 6 --- arch/s390/kernel/perf_cpum_sf.c | 6 --- arch/x86/include/asm/mmu.h | 2 + arch/x86/include/asm/mmu_context.h | 32 ++++++++++++++- arch/x86/include/asm/paravirt.h | 6 +-- arch/x86/include/asm/processor.h | 33 ---------------- arch/x86/include/asm/special_insns.h | 6 +-- arch/x86/include/asm/tlbflush.h | 77 ++++++++++++++++++++++++++++++++---- arch/x86/include/asm/virtext.h | 5 ++- arch/x86/kernel/acpi/sleep.c | 2 +- arch/x86/kernel/cpu/common.c | 17 +++++--- arch/x86/kernel/cpu/mcheck/mce.c | 3 +- arch/x86/kernel/cpu/mcheck/p5.c | 3 +- arch/x86/kernel/cpu/mcheck/winchip.c | 3 +- arch/x86/kernel/cpu/mtrr/cyrix.c | 6 +-- arch/x86/kernel/cpu/mtrr/generic.c | 6 +-- arch/x86/kernel/cpu/perf_event.c | 76 ++++++++++++++++++++++++++--------- arch/x86/kernel/cpu/perf_event.h | 2 + arch/x86/kernel/head32.c | 1 + arch/x86/kernel/head64.c | 2 + arch/x86/kernel/i387.c | 3 +- arch/x86/kernel/process.c | 5 ++- arch/x86/kernel/process_32.c | 2 +- arch/x86/kernel/process_64.c | 2 +- arch/x86/kernel/setup.c | 2 +- arch/x86/kernel/xsave.c | 3 +- arch/x86/kvm/svm.c | 2 +- arch/x86/kvm/vmx.c | 10 ++--- arch/x86/mm/fault.c | 2 +- arch/x86/mm/init.c | 12 +++++- arch/x86/mm/tlb.c | 3 -- arch/x86/power/cpu.c | 11 ++---- arch/x86/realmode/init.c | 2 +- arch/x86/xen/enlighten.c | 4 +- drivers/lguest/x86/core.c | 4 +- include/linux/perf_event.h | 7 ++++ kernel/events/core.c | 29 ++++++-------- kernel/events/hw_breakpoint.c | 7 ---- 39 files changed, 256 insertions(+), 154 deletions(-) -- 1.9.3