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2014-02-06KVM: x86: Fix potential divide by 0 in lapic (CVE-2013-6367)Andy Honig
commit b963a22e6d1a266a67e9eecc88134713fd54775c upstream. Under guest controllable circumstances apic_get_tmcct will execute a divide by zero and cause a crash. If the guest cpuid support tsc deadline timers and performs the following sequence of requests the host will crash. - Set the mode to periodic - Set the TMICT to 0 - Set the mode bits to 11 (neither periodic, nor one shot, nor tsc deadline) - Set the TMICT to non-zero. Then the lapic_timer.period will be 0, but the TMICT will not be. If the guest then reads from the TMCCT then the host will perform a divide by 0. This patch ensures that if the lapic_timer.period is 0, then the division does not occur. Reported-by: Andrew Honig <ahonig@google.com> Signed-off-by: Andrew Honig <ahonig@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> [bwh: Backported to 3.2: s/kvm_apic_get_reg/apic_get_reg/] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Cc: Vinson Lee <vlee@twopensource.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-29perf/x86/amd/ibs: Fix waking up from S3 for AMD family 10hRobert Richter
commit bee09ed91cacdbffdbcd3b05de8409c77ec9fcd6 upstream. On AMD family 10h we see following error messages while waking up from S3 for all non-boot CPUs leading to a failed IBS initialization: Enabling non-boot CPUs ... smpboot: Booting Node 0 Processor 1 APIC 0x1 [Firmware Bug]: cpu 1, try to use APIC500 (LVT offset 0) for vector 0x400, but the register is already in use for vector 0xf9 on another cpu perf: IBS APIC setup failed on cpu #1 process: Switch to broadcast mode on CPU1 CPU1 is up ... ACPI: Waking up from system sleep state S3 Reason for this is that during suspend the LVT offset for the IBS vector gets lost and needs to be reinialized while resuming. The offset is read from the IBSCTL msr. On family 10h the offset needs to be 1 as offset 0 is used for the MCE threshold interrupt, but firmware assings it for IBS to 0 too. The kernel needs to reprogram the vector. The msr is a readonly node msr, but a new value can be written via pci config space access. The reinitialization is implemented for family 10h in setup_ibs_ctl() which is forced during IBS setup. This patch fixes IBS setup after waking up from S3 by adding resume/supend hooks for the boot cpu which does the offset reinitialization. Marking it as stable to let distros pick up this fix. Signed-off-by: Robert Richter <rric@kernel.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1389797849-5565-1-git-send-email-rric.net@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-29KVM: x86: Convert vapic synchronization to _cached functions (CVE-2013-6368)Andy Honig
commit fda4e2e85589191b123d31cdc21fd33ee70f50fd upstream. In kvm_lapic_sync_from_vapic and kvm_lapic_sync_to_vapic there is the potential to corrupt kernel memory if userspace provides an address that is at the end of a page. This patches concerts those functions to use kvm_write_guest_cached and kvm_read_guest_cached. It also checks the vapic_address specified by userspace during ioctl processing and returns an error to userspace if the address is not a valid GPA. This is generally not guest triggerable, because the required write is done by firmware that runs before the guest. Also, it only affects AMD processors and oldish Intel that do not have the FlexPriority feature (unless you disable FlexPriority, of course; then newer processors are also affected). Fixes: b93463aa59d6 ('KVM: Accelerated apic support') Reported-by: Andrew Honig <ahonig@google.com> Cc: stable@vger.kernel.org Signed-off-by: Andrew Honig <ahonig@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> [ lizf: backported to 3.4: based on Paolo's backport hints for <3.10 ] Signed-off-by: Li Zefan <lizefan@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-15x86, fpu, amd: Clear exceptions in AMD FXSAVE workaroundLinus Torvalds
commit 26bef1318adc1b3a530ecc807ef99346db2aa8b0 upstream. Before we do an EMMS in the AMD FXSAVE information leak workaround we need to clear any pending exceptions, otherwise we trap with a floating-point exception inside this code. Reported-by: halfdog <me@halfdog.net> Tested-by: Borislav Petkov <bp@suse.de> Link: http://lkml.kernel.org/r/CA%2B55aFxQnY_PCG_n4=0w-VG=YLXL-yr7oMxyy0WU2gCBAf3ydg@mail.gmail.com Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-20x86, efi: Don't use (U)EFI time services on 32 bitMatthew Garrett
commit 04bf9ba720fcc4fa313fa122b799ae0989b6cd50 upstream. UEFI time services are often broken once we're in virtual mode. We were already refusing to use them on 64-bit systems, but it turns out that they're also broken on some 32-bit firmware, including the Dell Venue. Disable them for now, we can revisit once we have the 1:1 mappings code incorporated. Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com> Link: http://lkml.kernel.org/r/1385754283-2464-1-git-send-email-matthew.garrett@nebula.com Cc: Matt Fleming <matt.fleming@intel.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-29x86/microcode/amd: Tone down printk(), don't treat a missing firmware file ↵Thomas Renninger
as an error commit 11f918d3e2d3861b6931e97b3aa778e4984935aa upstream. Do it the same way as done in microcode_intel.c: use pr_debug() for missing firmware files. There seem to be CPUs out there for which no microcode update has been submitted to kernel-firmware repo yet resulting in scary sounding error messages in dmesg: microcode: failed to load file amd-ucode/microcode_amd_fam16h.bin Signed-off-by: Thomas Renninger <trenn@suse.de> Acked-by: Borislav Petkov <bp@suse.de> Link: http://lkml.kernel.org/r/1384274383-43510-1-git-send-email-trenn@suse.de Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-05x86, efi: Don't map Boot Services on i386Josh Boyer
commit 700870119f49084da004ab588ea2b799689efaf7 upstream. Add patch to fix 32bit EFI service mapping (rhbz 726701) Multiple people are reporting hitting the following WARNING on i386, WARNING: at arch/x86/mm/ioremap.c:102 __ioremap_caller+0x3d3/0x440() Modules linked in: Pid: 0, comm: swapper Not tainted 3.9.0-rc7+ #95 Call Trace: [<c102b6af>] warn_slowpath_common+0x5f/0x80 [<c1023fb3>] ? __ioremap_caller+0x3d3/0x440 [<c1023fb3>] ? __ioremap_caller+0x3d3/0x440 [<c102b6ed>] warn_slowpath_null+0x1d/0x20 [<c1023fb3>] __ioremap_caller+0x3d3/0x440 [<c106007b>] ? get_usage_chars+0xfb/0x110 [<c102d937>] ? vprintk_emit+0x147/0x480 [<c1418593>] ? efi_enter_virtual_mode+0x1e4/0x3de [<c102406a>] ioremap_cache+0x1a/0x20 [<c1418593>] ? efi_enter_virtual_mode+0x1e4/0x3de [<c1418593>] efi_enter_virtual_mode+0x1e4/0x3de [<c1407984>] start_kernel+0x286/0x2f4 [<c1407535>] ? repair_env_string+0x51/0x51 [<c1407362>] i386_start_kernel+0x12c/0x12f Due to the workaround described in commit 916f676f8 ("x86, efi: Retain boot service code until after switching to virtual mode") EFI Boot Service regions are mapped for a period during boot. Unfortunately, with the limited size of the i386 direct kernel map it's possible that some of the Boot Service regions will not be directly accessible, which causes them to be ioremap()'d, triggering the above warning as the regions are marked as E820_RAM in the e820 memmap. There are currently only two situations where we need to map EFI Boot Service regions, 1. To workaround the firmware bug described in 916f676f8 2. To access the ACPI BGRT image but since we haven't seen an i386 implementation that requires either, this simple fix should suffice for now. [ Added to changelog - Matt ] Reported-by: Bryan O'Donoghue <bryan.odonoghue.lkml@nexus-software.ie> Acked-by: Tom Zanussi <tom.zanussi@intel.com> Acked-by: Darren Hart <dvhart@linux.intel.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Josh Boyer <jwboyer@redhat.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-05x86/reboot: Add quirk to make Dell C6100 use reboot=pci automaticallyMasoud Sharbiani
commit 4f0acd31c31f03ba42494c8baf6c0465150e2621 upstream. Dell PowerEdge C6100 machines fail to completely reboot about 20% of the time. Signed-off-by: Masoud Sharbiani <msharbiani@twitter.com> Signed-off-by: Vinson Lee <vlee@twitter.com> Cc: Robin Holt <holt@sgi.com> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Link: http://lkml.kernel.org/r/1379717947-18042-1-git-send-email-vlee@freedesktop.org Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-09-14Revert "KVM: X86 emulator: fix source operand decoding for 8bit mov[zs]x ↵Greg Kroah-Hartman
instructions" This reverts commit 5b5b30580218eae22609989546bac6e44d0eda6e, which was commit 660696d1d16a71e15549ce1bf74953be1592bcd3 upstream. Paul Gortmaker <paul.gortmaker@windriver.com> writes: [this patch] introduces the following: arch/x86/kvm/emulate.c: In function ‘decode_operand’: arch/x86/kvm/emulate.c:3974:4: warning: passing argument 1 of ‘decode_register’ makes integer from pointer +without a cast [enabled by default] arch/x86/kvm/emulate.c:789:14: note: expected ‘u8’ but argument is of type ‘struct x86_emulate_ctxt *’ arch/x86/kvm/emulate.c:3974:4: warning: passing argument 2 of ‘decode_register’ makes pointer from integer +without a cast [enabled by default] arch/x86/kvm/emulate.c:789:14: note: expected ‘long unsigned int *’ but argument is of type ‘u8’ Based on the severity of the warnings above, I'm reasonably sure there will be some kind of runtime regressions due to this, but I stopped to investigate the warnings as soon as I saw them, before any run time testing. It happens because mainline v3.7-rc1~113^2~40 (dd856efafe60) does this: -static void *decode_register(u8 modrm_reg, unsigned long *regs, +static void *decode_register(struct x86_emulate_ctxt *ctxt, u8 modrm_reg, Since 660696d1d16a71e1 was only applied to stable 3.4, 3.8, and 3.9 -- and the prerequisite above is in 3.7+, the issue should be limited to 3.4.44+ Reported-by: Paul Gortmaker <paul.gortmaker@windriver.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Cc: Gleb Natapov <gleb@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-29x86/xen: do not identity map UNUSABLE regions in the machine E820David Vrabel
commit 3bc38cbceb85881a8eb789ee1aa56678038b1909 upstream. If there are UNUSABLE regions in the machine memory map, dom0 will attempt to map them 1:1 which is not permitted by Xen and the kernel will crash. There isn't anything interesting in the UNUSABLE region that the dom0 kernel needs access to so we can avoid making the 1:1 mapping and treat it as RAM. We only do this for dom0, as that is where tboot case shows up. A PV domU could have an UNUSABLE region in its pseudo-physical map and would need to be handled in another patch. This fixes a boot failure on hosts with tboot. tboot marks a region in the e820 map as unusable and the dom0 kernel would attempt to map this region and Xen does not permit unusable regions to be mapped by guests. (XEN) 0000000000000000 - 0000000000060000 (usable) (XEN) 0000000000060000 - 0000000000068000 (reserved) (XEN) 0000000000068000 - 000000000009e000 (usable) (XEN) 0000000000100000 - 0000000000800000 (usable) (XEN) 0000000000800000 - 0000000000972000 (unusable) tboot marked this region as unusable. (XEN) 0000000000972000 - 00000000cf200000 (usable) (XEN) 00000000cf200000 - 00000000cf38f000 (reserved) (XEN) 00000000cf38f000 - 00000000cf3ce000 (ACPI data) (XEN) 00000000cf3ce000 - 00000000d0000000 (reserved) (XEN) 00000000e0000000 - 00000000f0000000 (reserved) (XEN) 00000000fe000000 - 0000000100000000 (reserved) (XEN) 0000000100000000 - 0000000630000000 (usable) Signed-off-by: David Vrabel <david.vrabel@citrix.com> [v1: Altered the patch and description with domU's with UNUSABLE regions] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-11x86, fpu: correct the asm constraints for fxsave, unbreak mxcsr.dazH.J. Lu
commit eaa5a990191d204ba0f9d35dbe5505ec2cdd1460 upstream. GCC will optimize mxcsr_feature_mask_init in arch/x86/kernel/i387.c: memset(&fx_scratch, 0, sizeof(struct i387_fxsave_struct)); asm volatile("fxsave %0" : : "m" (fx_scratch)); mask = fx_scratch.mxcsr_mask; if (mask == 0) mask = 0x0000ffbf; to memset(&fx_scratch, 0, sizeof(struct i387_fxsave_struct)); asm volatile("fxsave %0" : : "m" (fx_scratch)); mask = 0x0000ffbf; since asm statement doesn’t say it will update fx_scratch. As the result, the DAZ bit will be cleared. This patch fixes it. This bug dates back to at least kernel 2.6.12. Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-21xen/time: remove blocked time accounting from xen "clockchip"Laszlo Ersek
commit 0b0c002c340e78173789f8afaa508070d838cf3d upstream. ... because the "clock_event_device framework" already accounts for idle time through the "event_handler" function pointer in xen_timer_interrupt(). The patch is intended as the completion of [1]. It should fix the double idle times seen in PV guests' /proc/stat [2]. It should be orthogonal to stolen time accounting (the removed code seems to be isolated). The approach may be completely misguided. [1] https://lkml.org/lkml/2011/10/6/10 [2] http://lists.xensource.com/archives/html/xen-devel/2010-08/msg01068.html John took the time to retest this patch on top of v3.10 and reported: "idle time is correctly incremented for pv and hvm for the normal case, nohz=off and nohz=idle." so lets put this patch in. Signed-off-by: Laszlo Ersek <lersek@redhat.com> Signed-off-by: John Haxby <john.haxby@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-06-27KVM: x86: remove vcpu's CPL check in host-invoked XCR setZhanghaoyu (A)
commit 764bcbc5a6d7a2f3e75c9f0e4caa984e2926e346 upstream. __kvm_set_xcr function does the CPL check when set xcr. __kvm_set_xcr is called in two flows, one is invoked by guest, call stack shown as below, handle_xsetbv(or xsetbv_interception) kvm_set_xcr __kvm_set_xcr the other one is invoked by host, for example during system reset: kvm_arch_vcpu_ioctl kvm_vcpu_ioctl_x86_set_xcrs __kvm_set_xcr The former does need the CPL check, but the latter does not. Signed-off-by: Zhang Haoyu <haoyu.zhang@huawei.com> [Tweaks to commit message. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-06-20x86: Fix typo in kexec register clearingKees Cook
commit c8a22d19dd238ede87aa0ac4f7dbea8da039b9c1 upstream. Fixes a typo in register clearing code. Thanks to PaX Team for fixing this originally, and James Troup for pointing it out. Signed-off-by: Kees Cook <keescook@chromium.org> Link: http://lkml.kernel.org/r/20130605184718.GA8396@www.outflux.net Cc: PaX Team <pageexec@freemail.hu> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-06-07x86, um: Correct syscall table type attributes breaking gcc 4.8Martin Pelikan
commit 9271b0b4b2044c6db06051fe60bc58cdd4f17c7c upstream. The latest GCC 4.8 does some more checking on type attributes that break the build for ARCH=um -> fill them in. Specifically, the "asmlinkage" attributes is now tested for consistency. Signed-off-by: Martin Pelikan <pelikan@storkhole.cz> Link: http://lkml.kernel.org/r/1339269731-10772-1-git-send-email-pelikan@storkhole.cz Acked-by: Richard Weinberger <richard@nod.at> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Bernhard M. Wiedemann <bwiedemann@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-05-19xen/vcpu/pvhvm: Fix vcpu hotplugging hanging.Konrad Rzeszutek Wilk
commit 7f1fc268c47491fd5e63548f6415fc8604e13003 upstream. If a user did: echo 0 > /sys/devices/system/cpu/cpu1/online echo 1 > /sys/devices/system/cpu/cpu1/online we would (this a build with DEBUG enabled) get to: smpboot: ++++++++++++++++++++=_---CPU UP 1 .. snip.. smpboot: Stack at about ffff880074c0ff44 smpboot: CPU1: has booted. and hang. The RCU mechanism would kick in an try to IPI the CPU1 but the IPIs (and all other interrupts) would never arrive at the CPU1. At first glance at least. A bit digging in the hypervisor trace shows that (using xenanalyze): [vla] d4v1 vec 243 injecting 0.043163027 --|x d4v1 intr_window vec 243 src 5(vector) intr f3 ] 0.043163639 --|x d4v1 vmentry cycles 1468 ] 0.043164913 --|x d4v1 vmexit exit_reason PENDING_INTERRUPT eip ffffffff81673254 0.043164913 --|x d4v1 inj_virq vec 243 real [vla] d4v1 vec 243 injecting 0.043164913 --|x d4v1 intr_window vec 243 src 5(vector) intr f3 ] 0.043165526 --|x d4v1 vmentry cycles 1472 ] 0.043166800 --|x d4v1 vmexit exit_reason PENDING_INTERRUPT eip ffffffff81673254 0.043166800 --|x d4v1 inj_virq vec 243 real [vla] d4v1 vec 243 injecting there is a pending event (subsequent debugging shows it is the IPI from the VCPU0 when smpboot.c on VCPU1 has done "set_cpu_online(smp_processor_id(), true)") and the guest VCPU1 is interrupted with the callback IPI (0xf3 aka 243) which ends up calling __xen_evtchn_do_upcall. The __xen_evtchn_do_upcall seems to do *something* but not acknowledge the pending events. And the moment the guest does a 'cli' (that is the ffffffff81673254 in the log above) the hypervisor is invoked again to inject the IPI (0xf3) to tell the guest it has pending interrupts. This repeats itself forever. The culprit was the per_cpu(xen_vcpu, cpu) pointer. At the bootup we set each per_cpu(xen_vcpu, cpu) to point to the shared_info->vcpu_info[vcpu] but later on use the VCPUOP_register_vcpu_info to register per-CPU structures (xen_vcpu_setup). This is used to allow events for more than 32 VCPUs and for performance optimizations reasons. When the user performs the VCPU hotplug we end up calling the the xen_vcpu_setup once more. We make the hypercall which returns -EINVAL as it does not allow multiple registration calls (and already has re-assigned where the events are being set). We pick the fallback case and set per_cpu(xen_vcpu, cpu) to point to the shared_info->vcpu_info[vcpu] (which is a good fallback during bootup). However the hypervisor is still setting events in the register per-cpu structure (per_cpu(xen_vcpu_info, cpu)). As such when the events are set by the hypervisor (such as timer one), and when we iterate in __xen_evtchn_do_upcall we end up reading stale events from the shared_info->vcpu_info[vcpu] instead of the per_cpu(xen_vcpu_info, cpu) structures. Hence we never acknowledge the events that the hypervisor has set and the hypervisor keeps on reminding us to ack the events which we never do. The fix is simple. Don't on the second time when xen_vcpu_setup is called over-write the per_cpu(xen_vcpu, cpu) if it points to per_cpu(xen_vcpu_info). Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-05-19KVM: VMX: fix halt emulation while emulating invalid guest sateGleb Natapov
commit 8d76c49e9ffeee839bc0b7a3278a23f99101263e upstream. The invalid guest state emulation loop does not check halt_request which causes 100% cpu loop while guest is in halt and in invalid state, but more serious issue is that this leaves halt_request set, so random instruction emulated by vm86 #GP exit can be interpreted as halt which causes guest hang. Fix both problems by handling halt_request in emulation loop. Reported-by: Tomas Papan <tomas.papan@gmail.com> Tested-by: Tomas Papan <tomas.papan@gmail.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-05-11x86/mm: account for PGDIR_SIZE alignmentJerry Hoemann
Patch for -stable. Function find_early_table_space removed upstream. Fixes panic in alloc_low_page due to pgt_buf overflow during init_memory_mapping. find_early_table_space sizes pgt_buf based upon the size of the memory being mapped, but it does not take into account the alignment of the memory. When the region being mapped spans a 512GB (PGDIR_SIZE) alignment, a panic from alloc_low_pages occurs. kernel_physical_mapping_init takes into account PGDIR_SIZE alignment. This causes an extra call to alloc_low_page to be made. This extra call isn't accounted for by find_early_table_space and causes a kernel panic. Change is to take into account PGDIR_SIZE alignment in find_early_table_space. Signed-off-by: Jerry Hoemann <jerry.hoemann@hp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-05-11perf/x86/intel/lbr: Demand proper privileges for PERF_SAMPLE_BRANCH_KERNELPeter Zijlstra
commit 7cc23cd6c0c7d7f4bee057607e7ce01568925717 upstream. We should always have proper privileges when requesting kernel data. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Andi Kleen <ak@linux.intel.com> Cc: eranian@google.com Link: http://lkml.kernel.org/r/20130503121256.230745028@chello.nl [ Fix build error reported by fengguang.wu@intel.com, propagate error code back. ] Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: http://lkml.kernel.org/n/tip-v0x9ky3ahzr6nm3c6ilwrili@git.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-05-11perf/x86/intel/lbr: Fix LBR filterPeter Zijlstra
commit 6e15eb3ba6c0249c9e8c783517d131b47db995ca upstream. The LBR 'from' adddress is under full userspace control; ensure we validate it before reading from it. Note: is_module_text_address() can potentially be quite expensive; for those running into that with high overhead in modules optimize it using an RCU backed rb-tree. Reported-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: eranian@google.com Link: http://lkml.kernel.org/r/20130503121256.158211806@chello.nl Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: http://lkml.kernel.org/n/tip-mk8i82ffzax01cnqo829iy1q@git.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-05-07x86: Eliminate irq_mis_count counted in arch_irq_statLi Fei
commit f7b0e1055574ce06ab53391263b4e205bf38daf3 upstream. With the current implementation, kstat_cpu(cpu).irqs_sum is also increased in case of irq_mis_count increment. So there is no need to count irq_mis_count in arch_irq_stat, otherwise irq_mis_count will be counted twice in the sum of /proc/stat. Reported-by: Liu Chuansheng <chuansheng.liu@intel.com> Signed-off-by: Li Fei <fei.li@intel.com> Acked-by: Liu Chuansheng <chuansheng.liu@intel.com> Cc: tomoki.sekiyama.qu@hitachi.com Cc: joe@perches.com Link: http://lkml.kernel.org/r/1366980611.32469.7.camel@fli24-HP-Compaq-8100-Elite-CMT-PC Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-05-07KVM: X86 emulator: fix source operand decoding for 8bit mov[zs]x instructionsGleb Natapov
commit 660696d1d16a71e15549ce1bf74953be1592bcd3 upstream. Source operand for one byte mov[zs]x is decoded incorrectly if it is in high byte register. Fix that. Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-05-07xen/time: Fix kasprintf splat when allocating timer%d IRQ line.Konrad Rzeszutek Wilk
commit 7918c92ae9638eb8a6ec18e2b4a0de84557cccc8 upstream. When we online the CPU, we get this splat: smpboot: Booting Node 0 Processor 1 APIC 0x2 installing Xen timer for CPU 1 BUG: sleeping function called from invalid context at /home/konrad/ssd/konrad/linux/mm/slab.c:3179 in_atomic(): 1, irqs_disabled(): 0, pid: 0, name: swapper/1 Pid: 0, comm: swapper/1 Not tainted 3.9.0-rc6upstream-00001-g3884fad #1 Call Trace: [<ffffffff810c1fea>] __might_sleep+0xda/0x100 [<ffffffff81194617>] __kmalloc_track_caller+0x1e7/0x2c0 [<ffffffff81303758>] ? kasprintf+0x38/0x40 [<ffffffff813036eb>] kvasprintf+0x5b/0x90 [<ffffffff81303758>] kasprintf+0x38/0x40 [<ffffffff81044510>] xen_setup_timer+0x30/0xb0 [<ffffffff810445af>] xen_hvm_setup_cpu_clockevents+0x1f/0x30 [<ffffffff81666d0a>] start_secondary+0x19c/0x1a8 The solution to that is use kasprintf in the CPU hotplug path that 'online's the CPU. That is, do it in in xen_hvm_cpu_notify, and remove the call to in xen_hvm_setup_cpu_clockevents. Unfortunatly the later is not a good idea as the bootup path does not use xen_hvm_cpu_notify so we would end up never allocating timer%d interrupt lines when booting. As such add the check for atomic() to continue. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-25perf/x86: Fix offcore_rsp valid mask for SNB/IVBStephane Eranian
commit f1923820c447e986a9da0fc6bf60c1dccdf0408e upstream. The valid mask for both offcore_response_0 and offcore_response_1 was wrong for SNB/SNB-EP, IVB/IVB-EP. It was possible to write to reserved bit and cause a GP fault crashing the kernel. This patch fixes the problem by correctly marking the reserved bits in the valid mask for all the processors mentioned above. A distinction between desktop and server parts is introduced because bits 24-30 are only available on the server parts. This version of the patch is just a rebase to perf/urgent tree and should apply to older kernels as well. Signed-off-by: Stephane Eranian <eranian@google.com> Cc: peterz@infradead.org Cc: jolsa@redhat.com Cc: ak@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-25KVM: Allow cross page reads and writes from cached translations.Andrew Honig
commit 8f964525a121f2ff2df948dac908dcc65be21b5b upstream. This patch adds support for kvm_gfn_to_hva_cache_init functions for reads and writes that will cross a page. If the range falls within the same memslot, then this will be a fast operation. If the range is split between two memslots, then the slower kvm_read_guest and kvm_write_guest are used. Tested: Test against kvm_clock unit tests. Signed-off-by: Andrew Honig <ahonig@google.com> Signed-off-by: Gleb Natapov <gleb@redhat.com> Cc: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-25KVM: x86: Convert MSR_KVM_SYSTEM_TIME to use gfn_to_hva_cache functions ↵Andy Honig
(CVE-2013-1797) commit 0b79459b482e85cb7426aa7da683a9f2c97aeae1 upstream. There is a potential use after free issue with the handling of MSR_KVM_SYSTEM_TIME. If the guest specifies a GPA in a movable or removable memory such as frame buffers then KVM might continue to write to that address even after it's removed via KVM_SET_USER_MEMORY_REGION. KVM pins the page in memory so it's unlikely to cause an issue, but if the user space component re-purposes the memory previously used for the guest, then the guest will be able to corrupt that memory. Tested: Tested against kvmclock unit test Signed-off-by: Andrew Honig <ahonig@google.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Cc: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-25KVM: x86: fix for buffer overflow in handling of MSR_KVM_SYSTEM_TIME ↵Andy Honig
(CVE-2013-1796) commit c300aa64ddf57d9c5d9c898a64b36877345dd4a9 upstream. If the guest sets the GPA of the time_page so that the request to update the time straddles a page then KVM will write onto an incorrect page. The write is done byusing kmap atomic to get a pointer to the page for the time structure and then performing a memcpy to that page starting at an offset that the guest controls. Well behaved guests always provide a 32-byte aligned address, however a malicious guest could use this to corrupt host kernel memory. Tested: Tested against kvmclock unit test. Signed-off-by: Andrew Honig <ahonig@google.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Cc: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-16x86, mm: Patch out arch_flush_lazy_mmu_mode() when running on bare metalBoris Ostrovsky
commit 511ba86e1d386f671084b5d0e6f110bb30b8eeb2 upstream. Invoking arch_flush_lazy_mmu_mode() results in calls to preempt_enable()/disable() which may have performance impact. Since lazy MMU is not used on bare metal we can patch away arch_flush_lazy_mmu_mode() so that it is never called in such environment. [ hpa: the previous patch "Fix vmalloc_fault oops during lazy MMU updates" may cause a minor performance regression on bare metal. This patch resolves that performance regression. It is somewhat unclear to me if this is a good -stable candidate. ] Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Link: http://lkml.kernel.org/r/1364045796-10720-2-git-send-email-konrad.wilk@oracle.com Tested-by: Josh Boyer <jwboyer@redhat.com> Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Acked-by: Borislav Petkov <bp@suse.de> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-16x86, mm, paravirt: Fix vmalloc_fault oops during lazy MMU updatesSamu Kallio
commit 1160c2779b826c6f5c08e5cc542de58fd1f667d5 upstream. In paravirtualized x86_64 kernels, vmalloc_fault may cause an oops when lazy MMU updates are enabled, because set_pgd effects are being deferred. One instance of this problem is during process mm cleanup with memory cgroups enabled. The chain of events is as follows: - zap_pte_range enables lazy MMU updates - zap_pte_range eventually calls mem_cgroup_charge_statistics, which accesses the vmalloc'd mem_cgroup per-cpu stat area - vmalloc_fault is triggered which tries to sync the corresponding PGD entry with set_pgd, but the update is deferred - vmalloc_fault oopses due to a mismatch in the PUD entries The OOPs usually looks as so: ------------[ cut here ]------------ kernel BUG at arch/x86/mm/fault.c:396! invalid opcode: 0000 [#1] SMP .. snip .. CPU 1 Pid: 10866, comm: httpd Not tainted 3.6.10-4.fc18.x86_64 #1 RIP: e030:[<ffffffff816271bf>] [<ffffffff816271bf>] vmalloc_fault+0x11f/0x208 .. snip .. Call Trace: [<ffffffff81627759>] do_page_fault+0x399/0x4b0 [<ffffffff81004f4c>] ? xen_mc_extend_args+0xec/0x110 [<ffffffff81624065>] page_fault+0x25/0x30 [<ffffffff81184d03>] ? mem_cgroup_charge_statistics.isra.13+0x13/0x50 [<ffffffff81186f78>] __mem_cgroup_uncharge_common+0xd8/0x350 [<ffffffff8118aac7>] mem_cgroup_uncharge_page+0x57/0x60 [<ffffffff8115fbc0>] page_remove_rmap+0xe0/0x150 [<ffffffff8115311a>] ? vm_normal_page+0x1a/0x80 [<ffffffff81153e61>] unmap_single_vma+0x531/0x870 [<ffffffff81154962>] unmap_vmas+0x52/0xa0 [<ffffffff81007442>] ? pte_mfn_to_pfn+0x72/0x100 [<ffffffff8115c8f8>] exit_mmap+0x98/0x170 [<ffffffff810050d9>] ? __raw_callee_save_xen_pmd_val+0x11/0x1e [<ffffffff81059ce3>] mmput+0x83/0xf0 [<ffffffff810624c4>] exit_mm+0x104/0x130 [<ffffffff8106264a>] do_exit+0x15a/0x8c0 [<ffffffff810630ff>] do_group_exit+0x3f/0xa0 [<ffffffff81063177>] sys_exit_group+0x17/0x20 [<ffffffff8162bae9>] system_call_fastpath+0x16/0x1b Calling arch_flush_lazy_mmu_mode immediately after set_pgd makes the changes visible to the consistency checks. RedHat-Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=914737 Tested-by: Josh Boyer <jwboyer@redhat.com> Reported-and-Tested-by: Krishna Raman <kraman@redhat.com> Signed-off-by: Samu Kallio <samu.kallio@aberdeencloud.com> Link: http://lkml.kernel.org/r/1364045796-10720-1-git-send-email-konrad.wilk@oracle.com Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-12x86: Fix rebuild with EFI_STUB enabledJan Beulich
commit 918708245e92941df16a634dc201b407d12bcd91 upstream. eboot.o and efi_stub_$(BITS).o didn't get added to "targets", and hence their .cmd files don't get included by the build machinery, leading to the files always getting rebuilt. Rather than adding the two files individually, take the opportunity and add $(VMLINUX_OBJS) to "targets" instead, thus allowing the assignment at the top of the file to be shrunk quite a bit. At the same time, remove a pointless flags override line - the variable assigned to was misspelled anyway, and the options added are meaningless for assembly sources. [ hpa: the patch is not minimal, but I am taking it for -urgent anyway since the excess impact of the patch seems to be small enough. ] Signed-off-by: Jan Beulich <jbeulich@suse.com> Link: http://lkml.kernel.org/r/515C5D2502000078000CA6AD@nat28.tlf.novell.com Cc: Matthew Garrett <mjg@redhat.com> Cc: Matt Fleming <matt.fleming@intel.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-12x86: remove the x32 syscall bitmask from syscall_get_nr()Paul Moore
commit 8b4b9f27e57584f3d90e0bb84cf800ad81cfe3a1 upstream. Commit fca460f95e928bae373daa8295877b6905bc62b8 simplified the x32 implementation by creating a syscall bitmask, equal to 0x40000000, that could be applied to x32 syscalls such that the masked syscall number would be the same as a x86_64 syscall. While that patch was a nice way to simplify the code, it went a bit too far by adding the mask to syscall_get_nr(); returning the masked syscall numbers can cause confusion with callers that expect syscall numbers matching the x32 ABI, e.g. unmasked syscall numbers. This patch fixes this by simply removing the mask from syscall_get_nr() while preserving the other changes from the original commit. While there are several syscall_get_nr() callers in the kernel, most simply check that the syscall number is greater than zero, in this case this patch will have no effect. Of those remaining callers, they appear to be few, seccomp and ftrace, and from my testing of seccomp without this patch the original commit definitely breaks things; the seccomp filter does not correctly filter the syscalls due to the difference in syscall numbers in the BPF filter and the value from syscall_get_nr(). Applying this patch restores the seccomp BPF filter functionality on x32. I've tested this patch with the seccomp BPF filters as well as ftrace and everything looks reasonable to me; needless to say general usage seemed fine as well. Signed-off-by: Paul Moore <pmoore@redhat.com> Link: http://lkml.kernel.org/r/20130215172143.12549.10292.stgit@localhost Cc: Will Drewry <wad@chromium.org> Cc: H. Peter Anvin <hpa@zytor.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-05signal: Define __ARCH_HAS_SA_RESTORER so we know whether to clear sa_restorerBen Hutchings
Vaguely based on upstream commit 574c4866e33d 'consolidate kernel-side struct sigaction declarations'. flush_signal_handlers() needs to know whether sigaction::sa_restorer is defined, not whether SA_RESTORER is defined. Define the __ARCH_HAS_SA_RESTORER macro to indicate this. Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-28x86-64: Fix the failure case in copy_user_handle_tail()CQ Tang
commit 66db3feb486c01349f767b98ebb10b0c3d2d021b upstream. The increment of "to" in copy_user_handle_tail() will have incremented before a failure has been noted. This causes us to skip a byte in the failure case. Only do the increment when assured there is no failure. Signed-off-by: CQ Tang <cq.tang@intel.com> Link: http://lkml.kernel.org/r/20130318150221.8439.993.stgit@phlsvslse11.ph.intel.com Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-20perf,x86: fix wrmsr_on_cpu() warning on suspend/resumeLinus Torvalds
commit 2a6e06b2aed6995af401dcd4feb5e79a0c7ea554 upstream. Commit 1d9d8639c063 ("perf,x86: fix kernel crash with PEBS/BTS after suspend/resume") fixed a crash when doing PEBS performance profiling after resuming, but in using init_debug_store_on_cpu() to restore the DS_AREA mtrr it also resulted in a new WARN_ON() triggering. init_debug_store_on_cpu() uses "wrmsr_on_cpu()", which in turn uses CPU cross-calls to do the MSR update. Which is not really valid at the early resume stage, and the warning is quite reasonable. Now, it all happens to _work_, for the simple reason that smp_call_function_single() ends up just doing the call directly on the CPU when the CPU number matches, but we really should just do the wrmsr() directly instead. This duplicates the wrmsr() logic, but hopefully we can just remove the wrmsr_on_cpu() version eventually. Reported-and-tested-by: Parag Warudkar <parag.lkml@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-20perf,x86: fix kernel crash with PEBS/BTS after suspend/resumeStephane Eranian
commit 1d9d8639c063caf6efc2447f5f26aa637f844ff6 upstream. This patch fixes a kernel crash when using precise sampling (PEBS) after a suspend/resume. Turns out the CPU notifier code is not invoked on CPU0 (BP). Therefore, the DS_AREA (used by PEBS) is not restored properly by the kernel and keeps it power-on/resume value of 0 causing any PEBS measurement to crash when running on CPU0. The workaround is to add a hook in the actual resume code to restore the DS Area MSR value. It is invoked for all CPUS. So for all but CPU0, the DS_AREA will be restored twice but this is harmless. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Stephane Eranian <eranian@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-14xen/pat: Disable PAT using pat_enabled value.Konrad Rzeszutek Wilk
commit c79c49826270b8b0061b2fca840fc3f013c8a78a upstream. The git commit 8eaffa67b43e99ae581622c5133e20b0f48bcef1 (xen/pat: Disable PAT support for now) explains in details why we want to disable PAT for right now. However that change was not enough and we should have also disabled the pat_enabled value. Otherwise we end up with: mmap-example:3481 map pfn expected mapping type write-back for [mem 0x00010000-0x00010fff], got uncached-minus ------------[ cut here ]------------ WARNING: at /build/buildd/linux-3.8.0/arch/x86/mm/pat.c:774 untrack_pfn+0xb8/0xd0() mem 0x00010000-0x00010fff], got uncached-minus ------------[ cut here ]------------ WARNING: at /build/buildd/linux-3.8.0/arch/x86/mm/pat.c:774 untrack_pfn+0xb8/0xd0() ... Pid: 3481, comm: mmap-example Tainted: GF 3.8.0-6-generic #13-Ubuntu Call Trace: [<ffffffff8105879f>] warn_slowpath_common+0x7f/0xc0 [<ffffffff810587fa>] warn_slowpath_null+0x1a/0x20 [<ffffffff8104bcc8>] untrack_pfn+0xb8/0xd0 [<ffffffff81156c1c>] unmap_single_vma+0xac/0x100 [<ffffffff81157459>] unmap_vmas+0x49/0x90 [<ffffffff8115f808>] exit_mmap+0x98/0x170 [<ffffffff810559a4>] mmput+0x64/0x100 [<ffffffff810560f5>] dup_mm+0x445/0x660 [<ffffffff81056d9f>] copy_process.part.22+0xa5f/0x1510 [<ffffffff81057931>] do_fork+0x91/0x350 [<ffffffff81057c76>] sys_clone+0x16/0x20 [<ffffffff816ccbf9>] stub_clone+0x69/0x90 [<ffffffff816cc89d>] ? system_call_fastpath+0x1a/0x1f ---[ end trace 4918cdd0a4c9fea4 ]--- (a similar message shows up if you end up launching 'mcelog') The call chain is (as analyzed by Liu, Jinsong): do_fork --> copy_process --> dup_mm --> dup_mmap --> copy_page_range --> track_pfn_copy --> reserve_pfn_range --> line 624: flags != want_flags It comes from different memory types of page table (_PAGE_CACHE_WB) and MTRR (_PAGE_CACHE_UC_MINUS). Stefan Bader dug in this deep and found out that: "That makes it clearer as this will do reserve_memtype(...) --> pat_x_mtrr_type --> mtrr_type_lookup --> __mtrr_type_lookup And that can return -1/0xff in case of MTRR not being enabled/initialized. Which is not the case (given there are no messages for it in dmesg). This is not equal to MTRR_TYPE_WRBACK and thus becomes _PAGE_CACHE_UC_MINUS. It looks like the problem starts early in reserve_memtype: if (!pat_enabled) { /* This is identical to page table setting without PAT */ if (new_type) { if (req_type == _PAGE_CACHE_WC) *new_type = _PAGE_CACHE_UC_MINUS; else *new_type = req_type & _PAGE_CACHE_MASK; } return 0; } This would be what we want, that is clearing the PWT and PCD flags from the supported flags - if pat_enabled is disabled." This patch does that - disabling PAT. Reported-by: Sander Eikelenboom <linux@eikelenboom.it> Reported-and-Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reported-and-Tested-by: Stefan Bader <stefan.bader@canonical.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-14xen/pci: We don't do multiple MSI's.Konrad Rzeszutek Wilk
commit 884ac2978a295b7df3c4a686d3bff6932bbbb460 upstream. There is no hypercall to setup multiple MSI per PCI device. As such with these two new commits: - 08261d87f7d1b6253ab3223756625a5c74532293 PCI/MSI: Enable multiple MSIs with pci_enable_msi_block_auto() - 5ca72c4f7c412c2002363218901eba5516c476b1 AHCI: Support multiple MSIs we would call the PHYSDEVOP_map_pirq 'nvec' times with the same contents of the PCI device. Sander discovered that we would get the same PIRQ value 'nvec' times and return said values to the caller. That of course meant that the device was configured only with one MSI and AHCI would fail with: ahci 0000:00:11.0: version 3.0 xen: registering gsi 19 triggering 0 polarity 1 xen: --> pirq=19 -> irq=19 (gsi=19) (XEN) [2013-02-27 19:43:07] IOAPIC[0]: Set PCI routing entry (6-19 -> 0x99 -> IRQ 19 Mode:1 Active:1) ahci 0000:00:11.0: AHCI 0001.0200 32 slots 4 ports 6 Gbps 0xf impl SATA mode ahci 0000:00:11.0: flags: 64bit ncq sntf ilck pm led clo pmp pio slum part ahci: probe of 0000:00:11.0 failed with error -22 That is b/c in ahci_host_activate the second call to devm_request_threaded_irq would return -EINVAL as we passed in (on the second run) an IRQ that was never initialized. Reported-and-Tested-by: Sander Eikelenboom <linux@eikelenboom.it> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-04x86: Make sure we can boot in the case the BDA contains pure garbageH. Peter Anvin
commit 7c10093692ed2e6f318387d96b829320aa0ca64c upstream. On non-BIOS platforms it is possible that the BIOS data area contains garbage instead of being zeroed or something equivalent (firmware people: we are talking of 1.5K here, so please do the sane thing.) We need on the order of 20-30K of low memory in order to boot, which may grow up to < 64K in the future. We probably want to avoid the lowest of the low memory. At the same time, it seems extremely unlikely that a legitimate EBDA would ever reach down to the 128K (which would require it to be over half a megabyte in size.) Thus, pick 128K as the cutoff for "this is insane, ignore." We may still end up reserving a bunch of extra memory on the low megabyte, but that is not really a major issue these days. In the worst case we lose 512K of RAM. This code really should be merged with trim_bios_range() in arch/x86/kernel/setup.c, but that is a bigger patch for a later merge window. Reported-by: Darren Hart <dvhart@linux.intel.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Cc: Matt Fleming <matt.fleming@intel.com> Link: http://lkml.kernel.org/n/tip-oebml055yyfm8yxmria09rja@git.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-04x86, efi: Make "noefi" really disable EFI runtime serivcesMatt Fleming
commit fb834c7acc5e140cf4f9e86da93a66de8c0514da upstream. commit 1de63d60cd5b ("efi: Clear EFI_RUNTIME_SERVICES rather than EFI_BOOT by "noefi" boot parameter") attempted to make "noefi" true to its documentation and disable EFI runtime services to prevent the bricking bug described in commit e0094244e41c ("samsung-laptop: Disable on EFI hardware"). However, it's not possible to clear EFI_RUNTIME_SERVICES from an early param function because EFI_RUNTIME_SERVICES is set in efi_init() *after* parse_early_param(). This resulted in "noefi" effectively becoming a no-op and no longer providing users with a way to disable EFI, which is bad for those users that have buggy machines. Reported-by: Walt Nelson Jr <walt0924@gmail.com> Cc: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com> Link: http://lkml.kernel.org/r/1361392572-25657-1-git-send-email-matt@console-pimps.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-28xen: Send spinlock IPI to all waitersStefan Bader
commit 76eaca031f0af2bb303e405986f637811956a422 upstream. There is a loophole between Xen's current implementation of pv-spinlocks and the scheduler. This was triggerable through a testcase until v3.6 changed the TLB flushing code. The problem potentially is still there just not observable in the same way. What could happen was (is): 1. CPU n tries to schedule task x away and goes into a slow wait for the runq lock of CPU n-# (must be one with a lower number). 2. CPU n-#, while processing softirqs, tries to balance domains and goes into a slow wait for its own runq lock (for updating some records). Since this is a spin_lock_irqsave in softirq context, interrupts will be re-enabled for the duration of the poll_irq hypercall used by Xen. 3. Before the runq lock of CPU n-# is unlocked, CPU n-1 receives an interrupt (e.g. endio) and when processing the interrupt, tries to wake up task x. But that is in schedule and still on_cpu, so try_to_wake_up goes into a tight loop. 4. The runq lock of CPU n-# gets unlocked, but the message only gets sent to the first waiter, which is CPU n-# and that is busily stuck. 5. CPU n-# never returns from the nested interruption to take and release the lock because the scheduler uses a busy wait. And CPU n never finishes the task migration because the unlock notification only went to CPU n-#. To avoid this and since the unlocking code has no real sense of which waiter is best suited to grab the lock, just send the IPI to all of them. This causes the waiters to return from the hyper- call (those not interrupted at least) and do active spinlocking. BugLink: http://bugs.launchpad.net/bugs/1011792 Acked-by: Jan Beulich <JBeulich@suse.com> Signed-off-by: Stefan Bader <stefan.bader@canonical.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-28x86: Hyper-V: register clocksource only if its advertisedOlaf Hering
commit 32068f6527b8f1822a30671dedaf59c567325026 upstream. Enable hyperv_clocksource only if its advertised as a feature. XenServer 6 returns the signature which is checked in ms_hyperv_platform(), but it does not offer all features. Currently the clocksource is enabled unconditionally in ms_hyperv_init_platform(), and the result is a hanging guest. Hyper-V spec Bit 1 indicates the availability of Partition Reference Counter. Register the clocksource only if this bit is set. The guest in question prints this in dmesg: [ 0.000000] Hypervisor detected: Microsoft HyperV [ 0.000000] HyperV: features 0x70, hints 0x0 This bug can be reproduced easily be setting 'viridian=1' in a HVM domU .cfg file. A workaround without this patch is to boot the HVM guest with 'clocksource=jiffies'. Signed-off-by: Olaf Hering <olaf@aepfle.de> Link: http://lkml.kernel.org/r/1359940959-32168-1-git-send-email-kys@microsoft.com Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-28x86-32, mm: Remove reference to alloc_remap()H. Peter Anvin
commit 07f4207a305c834f528d08428df4531744e25678 upstream. We have removed the remap allocator for x86-32, and x86-64 never had it (and doesn't need it). Remove residual reference to it. Reported-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Cc: Dave Hansen <dave@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/CAE9FiQVn6_QZi3fNQ-JHYiR-7jeDJ5hT0SyT_%2BzVvfOj=PzF3w@mail.gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-28x86-32, mm: Remove reference to resume_map_numa_kva()H. Peter Anvin
commit bb112aec5ee41427e9b9726e3d57b896709598ed upstream. Remove reference to removed function resume_map_numa_kva(). Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Cc: Dave Hansen <dave@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/20130131005616.1C79F411@kernel.stglabs.ibm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-28x86-32, mm: Rip out x86_32 NUMA remapping codeDave Hansen
commit f03574f2d5b2d6229dcdf2d322848065f72953c7 upstream. This code was an optimization for 32-bit NUMA systems. It has probably been the cause of a number of subtle bugs over the years, although the conditions to excite them would have been hard to trigger. Essentially, we remap part of the kernel linear mapping area, and then sometimes part of that area gets freed back in to the bootmem allocator. If those pages get used by kernel data structures (say mem_map[] or a dentry), there's no big deal. But, if anyone ever tried to use the linear mapping for these pages _and_ cared about their physical address, bad things happen. For instance, say you passed __GFP_ZERO to the page allocator and then happened to get handed one of these pages, it zero the remapped page, but it would make a pte to the _old_ page. There are probably a hundred other ways that it could screw with things. We don't need to hang on to performance optimizations for these old boxes any more. All my 32-bit NUMA systems are long dead and buried, and I probably had access to more than most people. This code is causing real things to break today: https://lkml.org/lkml/2013/1/9/376 I looked in to actually fixing this, but it requires surgery to way too much brittle code, as well as stuff like per_cpu_ptr_to_phys(). [ hpa: Cc: this for -stable, since it is a memory corruption issue. However, an alternative is to simply mark NUMA as depends BROKEN rather than EXPERIMENTAL in the X86_32 subclause... ] Link: http://lkml.kernel.org/r/20130131005616.1C79F411@kernel.stglabs.ibm.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-17efi: Clear EFI_RUNTIME_SERVICES rather than EFI_BOOT by "noefi" boot parameterSatoru Takeuchi
commit 1de63d60cd5b0d33a812efa455d5933bf1564a51 upstream. There was a serious problem in samsung-laptop that its platform driver is designed to run under BIOS and running under EFI can cause the machine to become bricked or can cause Machine Check Exceptions. Discussion about this problem: https://bugs.launchpad.net/ubuntu-cdimage/+bug/1040557 https://bugzilla.kernel.org/show_bug.cgi?id=47121 The patches to fix this problem: efi: Make 'efi_enabled' a function to query EFI facilities 83e68189745ad931c2afd45d8ee3303929233e7f samsung-laptop: Disable on EFI hardware e0094244e41c4d0c7ad69920681972fc45d8ce34 Unfortunately this problem comes back again if users specify "noefi" option. This parameter clears EFI_BOOT and that driver continues to run even if running under EFI. Refer to the document, this parameter should clear EFI_RUNTIME_SERVICES instead. Documentation/kernel-parameters.txt: =============================================================================== ... noefi [X86] Disable EFI runtime services support. ... =============================================================================== Documentation/x86/x86_64/uefi.txt: =============================================================================== ... - If some or all EFI runtime services don't work, you can try following kernel command line parameters to turn off some or all EFI runtime services. noefi turn off all EFI runtime services ... =============================================================================== Signed-off-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com> Link: http://lkml.kernel.org/r/511C2C04.2070108@jp.fujitsu.com Cc: Matt Fleming <matt.fleming@intel.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-17x86/xen: don't assume %ds is usable in xen_iret for 32-bit PVOPS.Jan Beulich
commit 13d2b4d11d69a92574a55bfd985cfb0ca77aebdc upstream. This fixes CVE-2013-0228 / XSA-42 Drew Jones while working on CVE-2013-0190 found that that unprivileged guest user in 32bit PV guest can use to crash the > guest with the panic like this: ------------- general protection fault: 0000 [#1] SMP last sysfs file: /sys/devices/vbd-51712/block/xvda/dev Modules linked in: sunrpc ipt_REJECT nf_conntrack_ipv4 nf_defrag_ipv4 iptable_filter ip_tables ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables ipv6 xen_netfront ext4 mbcache jbd2 xen_blkfront dm_mirror dm_region_hash dm_log dm_mod [last unloaded: scsi_wait_scan] Pid: 1250, comm: r Not tainted 2.6.32-356.el6.i686 #1 EIP: 0061:[<c0407462>] EFLAGS: 00010086 CPU: 0 EIP is at xen_iret+0x12/0x2b EAX: eb8d0000 EBX: 00000001 ECX: 08049860 EDX: 00000010 ESI: 00000000 EDI: 003d0f00 EBP: b77f8388 ESP: eb8d1fe0 DS: 0000 ES: 007b FS: 0000 GS: 00e0 SS: 0069 Process r (pid: 1250, ti=eb8d0000 task=c2953550 task.ti=eb8d0000) Stack: 00000000 0027f416 00000073 00000206 b77f8364 0000007b 00000000 00000000 Call Trace: Code: c3 8b 44 24 18 81 4c 24 38 00 02 00 00 8d 64 24 30 e9 03 00 00 00 8d 76 00 f7 44 24 08 00 00 02 80 75 33 50 b8 00 e0 ff ff 21 e0 <8b> 40 10 8b 04 85 a0 f6 ab c0 8b 80 0c b0 b3 c0 f6 44 24 0d 02 EIP: [<c0407462>] xen_iret+0x12/0x2b SS:ESP 0069:eb8d1fe0 general protection fault: 0000 [#2] ---[ end trace ab0d29a492dcd330 ]--- Kernel panic - not syncing: Fatal exception Pid: 1250, comm: r Tainted: G D --------------- 2.6.32-356.el6.i686 #1 Call Trace: [<c08476df>] ? panic+0x6e/0x122 [<c084b63c>] ? oops_end+0xbc/0xd0 [<c084b260>] ? do_general_protection+0x0/0x210 [<c084a9b7>] ? error_code+0x73/ ------------- Petr says: " I've analysed the bug and I think that xen_iret() cannot cope with mangled DS, in this case zeroed out (null selector/descriptor) by either xen_failsafe_callback() or RESTORE_REGS because the corresponding LDT entry was invalidated by the reproducer. " Jan took a look at the preliminary patch and came up a fix that solves this problem: "This code gets called after all registers other than those handled by IRET got already restored, hence a null selector in %ds or a non-null one that got loaded from a code or read-only data descriptor would cause a kernel mode fault (with the potential of crashing the kernel as a whole, if panic_on_oops is set)." The way to fix this is to realize that the we can only relay on the registers that IRET restores. The two that are guaranteed are the %cs and %ss as they are always fixed GDT selectors. Also they are inaccessible from user mode - so they cannot be altered. This is the approach taken in this patch. Another alternative option suggested by Jan would be to relay on the subtle realization that using the %ebp or %esp relative references uses the %ss segment. In which case we could switch from using %eax to %ebp and would not need the %ss over-rides. That would also require one extra instruction to compensate for the one place where the register is used as scaled index. However Andrew pointed out that is too subtle and if further work was to be done in this code-path it could escape folks attention and lead to accidents. Reviewed-by: Petr Matousek <pmatouse@redhat.com> Reported-by: Petr Matousek <pmatouse@redhat.com> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> Signed-off-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-17x86/mm: Check if PUD is large when validating a kernel addressMel Gorman
commit 0ee364eb316348ddf3e0dfcd986f5f13f528f821 upstream. A user reported the following oops when a backup process reads /proc/kcore: BUG: unable to handle kernel paging request at ffffbb00ff33b000 IP: [<ffffffff8103157e>] kern_addr_valid+0xbe/0x110 [...] Call Trace: [<ffffffff811b8aaa>] read_kcore+0x17a/0x370 [<ffffffff811ad847>] proc_reg_read+0x77/0xc0 [<ffffffff81151687>] vfs_read+0xc7/0x130 [<ffffffff811517f3>] sys_read+0x53/0xa0 [<ffffffff81449692>] system_call_fastpath+0x16/0x1b Investigation determined that the bug triggered when reading system RAM at the 4G mark. On this system, that was the first address using 1G pages for the virt->phys direct mapping so the PUD is pointing to a physical address, not a PMD page. The problem is that the page table walker in kern_addr_valid() is not checking pud_large() and treats the physical address as if it was a PMD. If it happens to look like pmd_none then it'll silently fail, probably returning zeros instead of real data. If the data happens to look like a present PMD though, it will be walked resulting in the oops above. This patch adds the necessary pud_large() check. Unfortunately the problem was not readily reproducible and now they are running the backup program without accessing /proc/kcore so the patch has not been validated but I think it makes sense. Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel <riel@redhat.coM> Reviewed-by: Michal Hocko <mhocko@suse.cz> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20130211145236.GX21389@suse.de Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-17x86/apic: Work around boot failure on HP ProLiant DL980 G7 Server systemsStoney Wang
commit cb214ede7657db458fd0b2a25ea0b28dbf900ebc upstream. When a HP ProLiant DL980 G7 Server boots a regular kernel, there will be intermittent lost interrupts which could result in a hang or (in extreme cases) data loss. The reason is that this system only supports x2apic physical mode, while the kernel boots with a logical-cluster default setting. This bug can be worked around by specifying the "x2apic_phys" or "nox2apic" boot option, but we want to handle this system without requiring manual workarounds. The BIOS sets ACPI_FADT_APIC_PHYSICAL in FADT table. As all apicids are smaller than 255, BIOS need to pass the control to the OS with xapic mode, according to x2apic-spec, chapter 2.9. Current code handle x2apic when BIOS pass with xapic mode enabled: When user specifies x2apic_phys, or FADT indicates PHYSICAL: 1. During madt oem check, apic driver is set with xapic logical or xapic phys driver at first. 2. enable_IR_x2apic() will enable x2apic_mode. 3. if user specifies x2apic_phys on the boot line, x2apic_phys_probe() will install the correct x2apic phys driver and use x2apic phys mode. Otherwise it will skip the driver will let x2apic_cluster_probe to take over to install x2apic cluster driver (wrong one) even though FADT indicates PHYSICAL, because x2apic_phys_probe does not check FADT PHYSICAL. Add checking x2apic_fadt_phys in x2apic_phys_probe() to fix the problem. Signed-off-by: Stoney Wang <song-bo.wang@hp.com> [ updated the changelog and simplified the code ] Signed-off-by: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1360263182-16226-1-git-send-email-yinghai@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-17x86: Do not leak kernel page mapping locationsKees Cook
commit e575a86fdc50d013bf3ad3aa81d9100e8e6cc60d upstream. Without this patch, it is trivial to determine kernel page mappings by examining the error code reported to dmesg[1]. Instead, declare the entire kernel memory space as a violation of a present page. Additionally, since show_unhandled_signals is enabled by default, switch branch hinting to the more realistic expectation, and unobfuscate the setting of the PF_PROT bit to improve readability. [1] http://vulnfactory.org/blog/2013/02/06/a-linux-memory-trick/ Reported-by: Dan Rosenberg <dan.j.rosenberg@gmail.com> Suggested-by: Brad Spengler <spender@grsecurity.net> Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: H. Peter Anvin <hpa@zytor.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20130207174413.GA12485@www.outflux.net Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-14efi: Make 'efi_enabled' a function to query EFI facilitiesMatt Fleming
commit 83e68189745ad931c2afd45d8ee3303929233e7f upstream. Originally 'efi_enabled' indicated whether a kernel was booted from EFI firmware. Over time its semantics have changed, and it now indicates whether or not we are booted on an EFI machine with bit-native firmware, e.g. 64-bit kernel with 64-bit firmware. The immediate motivation for this patch is the bug report at, https://bugs.launchpad.net/ubuntu-cdimage/+bug/1040557 which details how running a platform driver on an EFI machine that is designed to run under BIOS can cause the machine to become bricked. Also, the following report, https://bugzilla.kernel.org/show_bug.cgi?id=47121 details how running said driver can also cause Machine Check Exceptions. Drivers need a new means of detecting whether they're running on an EFI machine, as sadly the expression, if (!efi_enabled) hasn't been a sufficient condition for quite some time. Users actually want to query 'efi_enabled' for different reasons - what they really want access to is the list of available EFI facilities. For instance, the x86 reboot code needs to know whether it can invoke the ResetSystem() function provided by the EFI runtime services, while the ACPI OSL code wants to know whether the EFI config tables were mapped successfully. There are also checks in some of the platform driver code to simply see if they're running on an EFI machine (which would make it a bad idea to do BIOS-y things). This patch is a prereq for the samsung-laptop fix patch. Signed-off-by: Matt Fleming <matt.fleming@intel.com> Cc: David Airlie <airlied@linux.ie> Cc: Corentin Chary <corentincj@iksaif.net> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Olof Johansson <olof@lixom.net> Cc: Peter Jones <pjones@redhat.com> Cc: Colin Ian King <colin.king@canonical.com> Cc: Steve Langasek <steve.langasek@canonical.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Konrad Rzeszutek Wilk <konrad@kernel.org> Cc: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>