Commit Graph

28323 Commits

Author SHA1 Message Date
Wanpeng Li
e39d200fa5 KVM: Fix stack-out-of-bounds read in write_mmio
Reported by syzkaller:

  BUG: KASAN: stack-out-of-bounds in write_mmio+0x11e/0x270 [kvm]
  Read of size 8 at addr ffff8803259df7f8 by task syz-executor/32298

  CPU: 6 PID: 32298 Comm: syz-executor Tainted: G           OE    4.15.0-rc2+ #18
  Hardware name: LENOVO ThinkCentre M8500t-N000/SHARKBAY, BIOS FBKTC1AUS 02/16/2016
  Call Trace:
   dump_stack+0xab/0xe1
   print_address_description+0x6b/0x290
   kasan_report+0x28a/0x370
   write_mmio+0x11e/0x270 [kvm]
   emulator_read_write_onepage+0x311/0x600 [kvm]
   emulator_read_write+0xef/0x240 [kvm]
   emulator_fix_hypercall+0x105/0x150 [kvm]
   em_hypercall+0x2b/0x80 [kvm]
   x86_emulate_insn+0x2b1/0x1640 [kvm]
   x86_emulate_instruction+0x39a/0xb90 [kvm]
   handle_exception+0x1b4/0x4d0 [kvm_intel]
   vcpu_enter_guest+0x15a0/0x2640 [kvm]
   kvm_arch_vcpu_ioctl_run+0x549/0x7d0 [kvm]
   kvm_vcpu_ioctl+0x479/0x880 [kvm]
   do_vfs_ioctl+0x142/0x9a0
   SyS_ioctl+0x74/0x80
   entry_SYSCALL_64_fastpath+0x23/0x9a

The path of patched vmmcall will patch 3 bytes opcode 0F 01 C1(vmcall)
to the guest memory, however, write_mmio tracepoint always prints 8 bytes
through *(u64 *)val since kvm splits the mmio access into 8 bytes. This
leaks 5 bytes from the kernel stack (CVE-2017-17741).  This patch fixes
it by just accessing the bytes which we operate on.

Before patch:

syz-executor-5567  [007] .... 51370.561696: kvm_mmio: mmio write len 3 gpa 0x10 val 0x1ffff10077c1010f

After patch:

syz-executor-13416 [002] .... 51302.299573: kvm_mmio: mmio write len 3 gpa 0x10 val 0xc1010f

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Tested-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-12-18 12:57:01 +01:00
Lan Tianyu
f298103359 KVM/x86: Check input paging mode when cs.l is set
Reported by syzkaller:
    WARNING: CPU: 0 PID: 27962 at arch/x86/kvm/emulate.c:5631 x86_emulate_insn+0x557/0x15f0 [kvm]
    Modules linked in: kvm_intel kvm [last unloaded: kvm]
    CPU: 0 PID: 27962 Comm: syz-executor Tainted: G    B   W        4.15.0-rc2-next-20171208+ #32
    Hardware name: Intel Corporation S1200SP/S1200SP, BIOS S1200SP.86B.01.03.0006.040720161253 04/07/2016
    RIP: 0010:x86_emulate_insn+0x557/0x15f0 [kvm]
    RSP: 0018:ffff8807234476d0 EFLAGS: 00010282
    RAX: 0000000000000000 RBX: ffff88072d0237a0 RCX: ffffffffa0065c4d
    RDX: 1ffff100e5a046f9 RSI: 0000000000000003 RDI: ffff88072d0237c8
    RBP: ffff880723447728 R08: ffff88072d020000 R09: ffffffffa008d240
    R10: 0000000000000002 R11: ffffed00e7d87db3 R12: ffff88072d0237c8
    R13: ffff88072d023870 R14: ffff88072d0238c2 R15: ffffffffa008d080
    FS:  00007f8a68666700(0000) GS:ffff880802200000(0000) knlGS:0000000000000000
    CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    CR2: 000000002009506c CR3: 000000071fec4005 CR4: 00000000003626f0
    Call Trace:
     x86_emulate_instruction+0x3bc/0xb70 [kvm]
     ? reexecute_instruction.part.162+0x130/0x130 [kvm]
     vmx_handle_exit+0x46d/0x14f0 [kvm_intel]
     ? trace_event_raw_event_kvm_entry+0xe7/0x150 [kvm]
     ? handle_vmfunc+0x2f0/0x2f0 [kvm_intel]
     ? wait_lapic_expire+0x25/0x270 [kvm]
     vcpu_enter_guest+0x720/0x1ef0 [kvm]
     ...

When CS.L is set, vcpu should run in the 64 bit paging mode.
Current kvm set_sregs function doesn't have such check when
userspace inputs sreg values. This will lead unexpected behavior.
This patch is to add checks for CS.L, EFER.LME, EFER.LMA and
CR4.PAE when get SREG inputs from userspace in order to avoid
unexpected behavior.

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Jim Mattson <jmattson@google.com>
Signed-off-by: Tianyu Lan <tianyu.lan@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-12-15 10:01:46 +01:00
Peter Xu
5663d8f9bb kvm: x86: fix WARN due to uninitialized guest FPU state
------------[ cut here ]------------
 Bad FPU state detected at kvm_put_guest_fpu+0xd8/0x2d0 [kvm], reinitializing FPU registers.
 WARNING: CPU: 1 PID: 4594 at arch/x86/mm/extable.c:103 ex_handler_fprestore+0x88/0x90
 CPU: 1 PID: 4594 Comm: qemu-system-x86 Tainted: G    B      OE    4.15.0-rc2+ #10
 RIP: 0010:ex_handler_fprestore+0x88/0x90
 Call Trace:
  fixup_exception+0x4e/0x60
  do_general_protection+0xff/0x270
  general_protection+0x22/0x30
 RIP: 0010:kvm_put_guest_fpu+0xd8/0x2d0 [kvm]
 RSP: 0018:ffff8803d5627810 EFLAGS: 00010246
  kvm_vcpu_reset+0x3b4/0x3c0 [kvm]
  kvm_apic_accept_events+0x1c0/0x240 [kvm]
  kvm_arch_vcpu_ioctl_run+0x1658/0x2fb0 [kvm]
  kvm_vcpu_ioctl+0x479/0x880 [kvm]
  do_vfs_ioctl+0x142/0x9a0
  SyS_ioctl+0x74/0x80
  do_syscall_64+0x15f/0x600

where kvm_put_guest_fpu is called without a prior kvm_load_guest_fpu.
To fix it, move kvm_load_guest_fpu to the very beginning of
kvm_arch_vcpu_ioctl_run.

Cc: stable@vger.kernel.org
Fixes: f775b13eed
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-12-14 09:24:35 +01:00
Wanpeng Li
d73235d17b KVM: X86: Fix load RFLAGS w/o the fixed bit
*** Guest State ***
 CR0: actual=0x0000000000000030, shadow=0x0000000060000010, gh_mask=fffffffffffffff7
 CR4: actual=0x0000000000002050, shadow=0x0000000000000000, gh_mask=ffffffffffffe871
 CR3 = 0x00000000fffbc000
 RSP = 0x0000000000000000  RIP = 0x0000000000000000
 RFLAGS=0x00000000         DR7 = 0x0000000000000400
        ^^^^^^^^^^

The failed vmentry is triggered by the following testcase when ept=Y:

    #include <unistd.h>
    #include <sys/syscall.h>
    #include <string.h>
    #include <stdint.h>
    #include <linux/kvm.h>
    #include <fcntl.h>
    #include <sys/ioctl.h>

    long r[5];
    int main()
    {
    	r[2] = open("/dev/kvm", O_RDONLY);
    	r[3] = ioctl(r[2], KVM_CREATE_VM, 0);
    	r[4] = ioctl(r[3], KVM_CREATE_VCPU, 7);
    	struct kvm_regs regs = {
    		.rflags = 0,
    	};
    	ioctl(r[4], KVM_SET_REGS, &regs);
    	ioctl(r[4], KVM_RUN, 0);
    }

X86 RFLAGS bit 1 is fixed set, userspace can simply clearing bit 1
of RFLAGS with KVM_SET_REGS ioctl which results in vmentry fails.
This patch fixes it by oring X86_EFLAGS_FIXED during ioctl.

Cc: stable@vger.kernel.org
Suggested-by: Jim Mattson <jmattson@google.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Quan Xu <quan.xu0@gmail.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Jim Mattson <jmattson@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-12-14 09:24:26 +01:00
Wanpeng Li
ed52870f46 KVM: MMU: Fix infinite loop when there is no available mmu page
The below test case can cause infinite loop in kvm when ept=0.

    #include <unistd.h>
    #include <sys/syscall.h>
    #include <string.h>
    #include <stdint.h>
    #include <linux/kvm.h>
    #include <fcntl.h>
    #include <sys/ioctl.h>

    long r[5];
    int main()
    {
    	r[2] = open("/dev/kvm", O_RDONLY);
    	r[3] = ioctl(r[2], KVM_CREATE_VM, 0);
    	r[4] = ioctl(r[3], KVM_CREATE_VCPU, 7);
    	ioctl(r[4], KVM_RUN, 0);
    }

It doesn't setup the memory regions, mmu_alloc_shadow/direct_roots() in
kvm return 1 when kvm fails to allocate root page table which can result
in beblow infinite loop:

    vcpu_run() {
    	for (;;) {
	    	r = vcpu_enter_guest()::kvm_mmu_reload() returns 1
	    	if (r <= 0)
	    		break;
	    	if (need_resched())
	    		cond_resched();
      }
    }

This patch fixes it by returning -ENOSPC when there is no available kvm mmu
page for root page table.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: stable@vger.kernel.org
Fixes: 26eeb53cf0 (KVM: MMU: Bail out immediately if there is no available mmu page)
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-12-14 09:24:14 +01:00
Linus Torvalds
c465fc11e5 KVM fixes for v4.15-rc3
ARM:
  * A number of issues in the vgic discovered using SMATCH
  * A bit one-off calculation in out stage base address mask (32-bit and
    64-bit)
  * Fixes to single-step debugging instructions that trap for other
    reasons such as MMMIO aborts
  * Printing unavailable hyp mode as error
  * Potential spinlock deadlock in the vgic
  * Avoid calling vgic vcpu free more than once
  * Broken bit calculation for big endian systems
 
 s390:
  * SPDX tags
  * Fence storage key accesses from problem state
  * Make sure that irq_state.flags is not used in the future
 
 x86:
  * Intercept port 0x80 accesses to prevent host instability (CVE)
  * Use userspace FPU context for guest FPU (mainly an optimization that
    fixes a double use of kernel FPU)
  * Do not leak one page per module load
  * Flush APIC page address cache from MMU invalidation notifiers
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM fixes from Radim Krčmář:
 "ARM:
   - A number of issues in the vgic discovered using SMATCH
   - A bit one-off calculation in out stage base address mask (32-bit
     and 64-bit)
   - Fixes to single-step debugging instructions that trap for other
     reasons such as MMMIO aborts
   - Printing unavailable hyp mode as error
   - Potential spinlock deadlock in the vgic
   - Avoid calling vgic vcpu free more than once
   - Broken bit calculation for big endian systems

 s390:
   - SPDX tags
   - Fence storage key accesses from problem state
   - Make sure that irq_state.flags is not used in the future

  x86:
   - Intercept port 0x80 accesses to prevent host instability (CVE)
   - Use userspace FPU context for guest FPU (mainly an optimization
     that fixes a double use of kernel FPU)
   - Do not leak one page per module load
   - Flush APIC page address cache from MMU invalidation notifiers"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (28 commits)
  KVM: x86: fix APIC page invalidation
  KVM: s390: Fix skey emulation permission check
  KVM: s390: mark irq_state.flags as non-usable
  KVM: s390: Remove redundant license text
  KVM: s390: add SPDX identifiers to the remaining files
  KVM: VMX: fix page leak in hardware_setup()
  KVM: VMX: remove I/O port 0x80 bypass on Intel hosts
  x86,kvm: remove KVM emulator get_fpu / put_fpu
  x86,kvm: move qemu/guest FPU switching out to vcpu_run
  KVM: arm/arm64: Fix broken GICH_ELRSR big endian conversion
  KVM: arm/arm64: kvm_arch_destroy_vm cleanups
  KVM: arm/arm64: Fix spinlock acquisition in vgic_set_owner
  kvm: arm: don't treat unavailable HYP mode as an error
  KVM: arm/arm64: Avoid attempting to load timer vgic state without a vgic
  kvm: arm64: handle single-step of hyp emulated mmio instructions
  kvm: arm64: handle single-step during SError exceptions
  kvm: arm64: handle single-step of userspace mmio instructions
  kvm: arm64: handle single-stepping trapped instructions
  KVM: arm/arm64: debug: Introduce helper for single-step
  arm: KVM: Fix VTTBR_BADDR_MASK BUG_ON off-by-one
  ...
2017-12-10 08:24:16 -08:00
Michal Hocko
f335195adf kmemcheck: rip it out for real
Commit 4675ff05de ("kmemcheck: rip it out") has removed the code but
for some reason SPDX header stayed in place.  This looks like a rebase
mistake in the mmotm tree or the merge mistake.  Let's drop those
leftovers as well.

Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-12-08 13:40:17 -08:00
Linus Torvalds
e9ef1fe312 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes from David Miller:

 1) CAN fixes from Martin Kelly (cancel URBs properly in all the CAN usb
    drivers).

 2) Revert returning -EEXIST from __dev_alloc_name() as this propagates
    to userspace and broke some apps. From Johannes Berg.

 3) Fix conn memory leaks and crashes in TIPC, from Jon Malloc and Cong
    Wang.

 4) Gianfar MAC can't do EEE so don't advertise it by default, from
    Claudiu Manoil.

 5) Relax strict netlink attribute validation, but emit a warning. From
    David Ahern.

 6) Fix regression in checksum offload of thunderx driver, from Florian
    Westphal.

 7) Fix UAPI bpf issues on s390, from Hendrik Brueckner.

 8) New card support in iwlwifi, from Ihab Zhaika.

 9) BBR congestion control bug fixes from Neal Cardwell.

10) Fix port stats in nfp driver, from Pieter Jansen van Vuuren.

11) Fix leaks in qualcomm rmnet, from Subash Abhinov Kasiviswanathan.

12) Fix DMA API handling in sh_eth driver, from Thomas Petazzoni.

13) Fix spurious netpoll warnings in bnxt_en, from Calvin Owens.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (67 commits)
  net: mvpp2: fix the RSS table entry offset
  tcp: evaluate packet losses upon RTT change
  tcp: fix off-by-one bug in RACK
  tcp: always evaluate losses in RACK upon undo
  tcp: correctly test congestion state in RACK
  bnxt_en: Fix sources of spurious netpoll warnings
  tcp_bbr: reset long-term bandwidth sampling on loss recovery undo
  tcp_bbr: reset full pipe detection on loss recovery undo
  tcp_bbr: record "full bw reached" decision in new full_bw_reached bit
  sfc: pass valid pointers from efx_enqueue_unwind
  gianfar: Disable EEE autoneg by default
  tcp: invalidate rate samples during SACK reneging
  can: peak/pcie_fd: fix potential bug in restarting tx queue
  can: usb_8dev: cancel urb on -EPIPE and -EPROTO
  can: kvaser_usb: cancel urb on -EPIPE and -EPROTO
  can: esd_usb2: cancel urb on -EPIPE and -EPROTO
  can: ems_usb: cancel urb on -EPIPE and -EPROTO
  can: mcba_usb: cancel urb on -EPROTO
  usbnet: fix alignment for frames with no ethernet header
  tcp: use current time in tcp_rcv_space_adjust()
  ...
2017-12-08 13:32:44 -08:00
Linus Torvalds
dd53a4214d Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull misc x86 fixes from Ingo Molnar:

 - make CR4 handling irq-safe, which bug vmware guests ran into

 - don't crash on early IRQs in Xen guests

 - don't crash secondary CPU bringup if #UD assisted WARN()ings are
   triggered

 - make X86_BUG_FXSAVE_LEAK optional on newer AMD CPUs that have the fix

 - fix AMD Fam17h microcode loading

 - fix broadcom_postcore_init() if ACPI is disabled

 - fix resume regression in __restore_processor_context()

 - fix Sparse warnings

 - fix a GCC-8 warning

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/vdso: Change time() prototype to match __vdso_time()
  x86: Fix Sparse warnings about non-static functions
  x86/power: Fix some ordering bugs in __restore_processor_context()
  x86/PCI: Make broadcom_postcore_init() check acpi_disabled
  x86/microcode/AMD: Add support for fam17h microcode loading
  x86/cpufeatures: Make X86_BUG_FXSAVE_LEAK detectable in CPUID on AMD
  x86/idt: Load idt early in start_secondary
  x86/xen: Support early interrupts in xen pv guests
  x86/tlb: Disable interrupts when changing CR4
  x86/tlb: Refactor CR4 setting and shadow write
2017-12-06 17:47:29 -08:00
Arnd Bergmann
88edb57d1e x86/vdso: Change time() prototype to match __vdso_time()
gcc-8 warns that time() is an alias for __vdso_time() but the two
have different prototypes:

  arch/x86/entry/vdso/vclock_gettime.c:327:5: error: 'time' alias between functions of incompatible types 'int(time_t *)' {aka 'int(long int *)'} and 'time_t(time_t *)' {aka 'long int(long int *)'} [-Werror=attribute-alias]
   int time(time_t *t)
       ^~~~
  arch/x86/entry/vdso/vclock_gettime.c:318:16: note: aliased declaration here

I could not figure out whether this is intentional, but I see that
changing it to return time_t avoids the warning.

Returning 'int' from time() is also a bit questionable, as it causes an
overflow in y2038 even on 64-bit architectures that use a 64-bit time_t
type. On 32-bit architecture with 64-bit time_t, time() should always
be implement by the C library by calling a (to be added) clock_gettime()
variant that takes a sufficiently wide argument.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Link: http://lkml.kernel.org/r/20171204150203.852959-1-arnd@arndb.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-06 21:31:46 +01:00
Colin Ian King
d553d03f70 x86: Fix Sparse warnings about non-static functions
Functions x86_vector_debug_show(), uv_handle_nmi() and uv_nmi_setup_common()
are local to the source and do not need to be in global scope, so make them
static.

Fixes up various sparse warnings.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Mike Travis <mike.travis@hpe.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Kosina <trivial@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russ Anderson <russ.anderson@hpe.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kernel-janitors@vger.kernel.org
Cc: travis@sgi.com
Link: http://lkml.kernel.org/r/20171206173358.24388-1-colin.king@canonical.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-06 19:32:58 +01:00
Radim Krčmář
b1394e745b KVM: x86: fix APIC page invalidation
Implementation of the unpinned APIC page didn't update the VMCS address
cache when invalidation was done through range mmu notifiers.
This became a problem when the page notifier was removed.

Re-introduce the arch-specific helper and call it from ...range_start.

Reported-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
Fixes: 38b9917350 ("kvm: vmx: Implement set_apic_access_page_addr")
Fixes: 369ea8242c ("mm/rmap: update to new mmu_notifier semantic v2")
Cc: <stable@vger.kernel.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Tested-by: Wanpeng Li <wanpeng.li@hotmail.com>
Tested-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-12-06 16:10:34 +01:00
Andy Lutomirski
5b06bbcfc2 x86/power: Fix some ordering bugs in __restore_processor_context()
__restore_processor_context() had a couple of ordering bugs.  It
restored GSBASE after calling load_gs_index(), and the latter can
call into tracing code.  It also tried to restore segment registers
before restoring the LDT, which is straight-up wrong.

Reorder the code so that we restore GSBASE, then the descriptor
tables, then the segments.

This fixes two bugs.  First, it fixes a regression that broke resume
under certain configurations due to irqflag tracing in
native_load_gs_index().  Second, it fixes resume when the userspace
process that initiated suspect had funny segments.  The latter can be
reproduced by compiling this:

// SPDX-License-Identifier: GPL-2.0
/*
 * ldt_echo.c - Echo argv[1] while using an LDT segment
 */

int main(int argc, char **argv)
{
	int ret;
	size_t len;
	char *buf;

	const struct user_desc desc = {
                .entry_number    = 0,
                .base_addr       = 0,
                .limit           = 0xfffff,
                .seg_32bit       = 1,
                .contents        = 0, /* Data, grow-up */
                .read_exec_only  = 0,
                .limit_in_pages  = 1,
                .seg_not_present = 0,
                .useable         = 0
        };

	if (argc != 2)
		errx(1, "Usage: %s STRING", argv[0]);

	len = asprintf(&buf, "%s\n", argv[1]);
	if (len < 0)
		errx(1, "Out of memory");

	ret = syscall(SYS_modify_ldt, 1, &desc, sizeof(desc));
	if (ret < -1)
		errno = -ret;
	if (ret)
		err(1, "modify_ldt");

	asm volatile ("movw %0, %%es" :: "rm" ((unsigned short)7));
	write(1, buf, len);
	return 0;
}

and running ldt_echo >/sys/power/mem

Without the fix, the latter causes a triple fault on resume.

Fixes: ca37e57bbe ("x86/entry/64: Add missing irqflags tracing to native_load_gs_index()")
Reported-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lkml.kernel.org/r/6b31721ea92f51ea839e79bd97ade4a75b1eeea2.1512057304.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-06 12:29:12 +01:00
Rafael J. Wysocki
ddec3bdee0 x86/PCI: Make broadcom_postcore_init() check acpi_disabled
acpi_os_get_root_pointer() may return a valid address even if acpi_disabled
is set, but the host bridge information from the ACPI tables is not going
to be used in that case and the Broadcom host bridge initialization should
not be skipped then, So make broadcom_postcore_init() check acpi_disabled
too to avoid this issue.

Fixes: 6361d72b04 (x86/PCI: read Broadcom CNB20LE host bridge info before PCI scan)
Reported-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Linux PCI <linux-pci@vger.kernel.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/3186627.pxZj1QbYNg@aspire.rjw.lan
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-06 12:27:47 +01:00
Tom Lendacky
f4e9b7af0c x86/microcode/AMD: Add support for fam17h microcode loading
The size for the Microcode Patch Block (MPB) for an AMD family 17h
processor is 3200 bytes.  Add a #define for fam17h so that it does
not default to 2048 bytes and fail a microcode load/update.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@alien8.de>
Link: https://lkml.kernel.org/r/20171130224640.15391.40247.stgit@tlendack-t1.amdoffice.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-06 12:27:24 +01:00
Rudolf Marek
e3811a3f74 x86/cpufeatures: Make X86_BUG_FXSAVE_LEAK detectable in CPUID on AMD
The latest AMD AMD64 Architecture Programmer's Manual
adds a CPUID feature XSaveErPtr (CPUID_Fn80000008_EBX[2]).

If this feature is set, the FXSAVE, XSAVE, FXSAVEOPT, XSAVEC, XSAVES
/ FXRSTOR, XRSTOR, XRSTORS always save/restore error pointers,
thus making the X86_BUG_FXSAVE_LEAK workaround obsolete on such CPUs.

Signed-off-by: Rudolf Marek <r.marek@assembler.cz>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Tested-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Link: https://lkml.kernel.org/r/bdcebe90-62c5-1f05-083c-eba7f08b2540@assembler.cz
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-06 12:27:13 +01:00
Linus Torvalds
328b4ed93b x86: don't hash faulting address in oops printout
Things like this will probably keep showing up for other architectures
and other special cases.

I actually thought we already used %lx for this, and that is indeed
_historically_ the case, but we moved to %p when merging the 32-bit and
64-bit cases as a convenient way to get the formatting right (ie
automatically picking "%08lx" vs "%016lx" based on register size).

So just turn this %p into %px.

Reported-by: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-12-05 17:59:29 -08:00
Kees Cook
b562c171cf locking/refcounts: Do not force refcount_t usage as GPL-only export
The refcount_t protection on x86 was not intended to use the stricter
GPL export. This adjusts the linkage again to avoid a regression in
the availability of the refcount API.

Reported-by: Dave Airlie <airlied@gmail.com>
Fixes: 7a46ec0e2f ("locking/refcounts, x86/asm: Implement fast refcount overflow protection")
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-12-05 17:14:31 -08:00
Jim Mattson
2895db67b0 KVM: VMX: fix page leak in hardware_setup()
vmx_io_bitmap_b should not be allocated twice.

Fixes: 2361133293 ("KVM: VMX: refactor setup of global page-sized bitmaps")
Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-12-05 22:34:49 +01:00
Andrew Honig
d59d51f088 KVM: VMX: remove I/O port 0x80 bypass on Intel hosts
This fixes CVE-2017-1000407.

KVM allows guests to directly access I/O port 0x80 on Intel hosts.  If
the guest floods this port with writes it generates exceptions and
instability in the host kernel, leading to a crash.  With this change
guest writes to port 0x80 on Intel will behave the same as they
currently behave on AMD systems.

Prevent the flooding by removing the code that sets port 0x80 as a
passthrough port.  This is essentially the same as upstream patch
99f85a28a7, except that patch was
for AMD chipsets and this patch is for Intel.

Signed-off-by: Andrew Honig <ahonig@google.com>
Signed-off-by: Jim Mattson <jmattson@google.com>
Fixes: fdef3ad1b3 ("KVM: VMX: Enable io bitmaps to avoid IO port 0x80 VMEXITs")
Cc: <stable@vger.kernel.org>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-12-05 22:32:51 +01:00
Rik van Riel
6ab0b9feb8 x86,kvm: remove KVM emulator get_fpu / put_fpu
Now that get_fpu and put_fpu do nothing, because the scheduler will
automatically load and restore the guest FPU context for us while we
are in this code (deep inside the vcpu_run main loop), we can get rid
of the get_fpu and put_fpu hooks.

Signed-off-by: Rik van Riel <riel@redhat.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-12-05 21:20:24 +01:00
Rik van Riel
f775b13eed x86,kvm: move qemu/guest FPU switching out to vcpu_run
Currently, every time a VCPU is scheduled out, the host kernel will
first save the guest FPU/xstate context, then load the qemu userspace
FPU context, only to then immediately save the qemu userspace FPU
context back to memory. When scheduling in a VCPU, the same extraneous
FPU loads and saves are done.

This could be avoided by moving from a model where the guest FPU is
loaded and stored with preemption disabled, to a model where the
qemu userspace FPU is swapped out for the guest FPU context for
the duration of the KVM_RUN ioctl.

This is done under the VCPU mutex, which is also taken when other
tasks inspect the VCPU FPU context, so the code should already be
safe for this change. That should come as no surprise, given that
s390 already has this optimization.

This can fix a bug where KVM calls get_user_pages while owning the
FPU, and the file system ends up requesting the FPU again:

    [258270.527947]  __warn+0xcb/0xf0
    [258270.527948]  warn_slowpath_null+0x1d/0x20
    [258270.527951]  kernel_fpu_disable+0x3f/0x50
    [258270.527953]  __kernel_fpu_begin+0x49/0x100
    [258270.527955]  kernel_fpu_begin+0xe/0x10
    [258270.527958]  crc32c_pcl_intel_update+0x84/0xb0
    [258270.527961]  crypto_shash_update+0x3f/0x110
    [258270.527968]  crc32c+0x63/0x8a [libcrc32c]
    [258270.527975]  dm_bm_checksum+0x1b/0x20 [dm_persistent_data]
    [258270.527978]  node_prepare_for_write+0x44/0x70 [dm_persistent_data]
    [258270.527985]  dm_block_manager_write_callback+0x41/0x50 [dm_persistent_data]
    [258270.527988]  submit_io+0x170/0x1b0 [dm_bufio]
    [258270.527992]  __write_dirty_buffer+0x89/0x90 [dm_bufio]
    [258270.527994]  __make_buffer_clean+0x4f/0x80 [dm_bufio]
    [258270.527996]  __try_evict_buffer+0x42/0x60 [dm_bufio]
    [258270.527998]  dm_bufio_shrink_scan+0xc0/0x130 [dm_bufio]
    [258270.528002]  shrink_slab.part.40+0x1f5/0x420
    [258270.528004]  shrink_node+0x22c/0x320
    [258270.528006]  do_try_to_free_pages+0xf5/0x330
    [258270.528008]  try_to_free_pages+0xe9/0x190
    [258270.528009]  __alloc_pages_slowpath+0x40f/0xba0
    [258270.528011]  __alloc_pages_nodemask+0x209/0x260
    [258270.528014]  alloc_pages_vma+0x1f1/0x250
    [258270.528017]  do_huge_pmd_anonymous_page+0x123/0x660
    [258270.528021]  handle_mm_fault+0xfd3/0x1330
    [258270.528025]  __get_user_pages+0x113/0x640
    [258270.528027]  get_user_pages+0x4f/0x60
    [258270.528063]  __gfn_to_pfn_memslot+0x120/0x3f0 [kvm]
    [258270.528108]  try_async_pf+0x66/0x230 [kvm]
    [258270.528135]  tdp_page_fault+0x130/0x280 [kvm]
    [258270.528149]  kvm_mmu_page_fault+0x60/0x120 [kvm]
    [258270.528158]  handle_ept_violation+0x91/0x170 [kvm_intel]
    [258270.528162]  vmx_handle_exit+0x1ca/0x1400 [kvm_intel]

No performance changes were detected in quick ping-pong tests on
my 4 socket system, which is expected since an FPU+xstate load is
on the order of 0.1us, while ping-ponging between CPUs is on the
order of 20us, and somewhat noisy.

Cc: stable@vger.kernel.org
Signed-off-by: Rik van Riel <riel@redhat.com>
Suggested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[Fixed a bug where reset_vcpu called put_fpu without preceding load_fpu,
 which happened inside from KVM_CREATE_VCPU ioctl. - Radim]
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-12-05 21:16:43 +01:00
Hendrik Brueckner
c895f6f703 bpf: correct broken uapi for BPF_PROG_TYPE_PERF_EVENT program type
Commit 0515e5999a ("bpf: introduce BPF_PROG_TYPE_PERF_EVENT
program type") introduced the bpf_perf_event_data structure which
exports the pt_regs structure.  This is OK for multiple architectures
but fail for s390 and arm64 which do not export pt_regs.  Programs
using them, for example, the bpf selftest fail to compile on these
architectures.

For s390, exporting the pt_regs is not an option because s390 wants
to allow changes to it.  For arm64, there is a user_pt_regs structure
that covers parts of the pt_regs structure for use by user space.

To solve the broken uapi for s390 and arm64, introduce an abstract
type for pt_regs and add an asm/bpf_perf_event.h file that concretes
the type.  An asm-generic header file covers the architectures that
export pt_regs today.

The arch-specific enablement for s390 and arm64 follows in separate
commits.

Reported-by: Thomas Richter <tmricht@linux.vnet.ibm.com>
Fixes: 0515e5999a ("bpf: introduce BPF_PROG_TYPE_PERF_EVENT program type")
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Reviewed-and-tested-by: Thomas Richter <tmricht@linux.vnet.ibm.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-12-05 15:02:40 +01:00
Linus Torvalds
9e0600f5cf * x86 bugfixes: APIC, nested virtualization, IOAPIC
* PPC bugfix: HPT guests on a POWER9 radix host
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM fixes from Paolo Bonzini:

 - x86 bugfixes: APIC, nested virtualization, IOAPIC

 - PPC bugfix: HPT guests on a POWER9 radix host

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (26 commits)
  KVM: Let KVM_SET_SIGNAL_MASK work as advertised
  KVM: VMX: Fix vmx->nested freeing when no SMI handler
  KVM: VMX: Fix rflags cache during vCPU reset
  KVM: X86: Fix softlockup when get the current kvmclock
  KVM: lapic: Fixup LDR on load in x2apic
  KVM: lapic: Split out x2apic ldr calculation
  KVM: PPC: Book3S HV: Fix migration and HPT resizing of HPT guests on radix hosts
  KVM: vmx: use X86_CR4_UMIP and X86_FEATURE_UMIP
  KVM: x86: Fix CPUID function for word 6 (80000001_ECX)
  KVM: nVMX: Fix vmx_check_nested_events() return value in case an event was reinjected to L2
  KVM: x86: ioapic: Preserve read-only values in the redirection table
  KVM: x86: ioapic: Clear Remote IRR when entry is switched to edge-triggered
  KVM: x86: ioapic: Remove redundant check for Remote IRR in ioapic_set_irq
  KVM: x86: ioapic: Don't fire level irq when Remote IRR set
  KVM: x86: ioapic: Fix level-triggered EOI and IOAPIC reconfigure race
  KVM: x86: inject exceptions produced by x86_decode_insn
  KVM: x86: Allow suppressing prints on RDMSR/WRMSR of unhandled MSRs
  KVM: x86: fix em_fxstor() sleeping while in atomic
  KVM: nVMX: Fix mmu context after VMLAUNCH/VMRESUME failure
  KVM: nVMX: Validate the IA32_BNDCFGS on nested VM-entry
  ...
2017-11-30 08:15:19 -08:00
Dan Williams
e4e40e0263 mm: switch to 'define pmd_write' instead of __HAVE_ARCH_PMD_WRITE
In response to compile breakage introduced by a series that added the
pud_write helper to x86, Stephen notes:

    did you consider using the other paradigm:

    In arch include files:
    #define pud_write       pud_write
    static inline int pud_write(pud_t pud)
     .....

    Then in include/asm-generic/pgtable.h:

    #ifndef pud_write
    tatic inline int pud_write(pud_t pud)
    {
            ....
    }
    #endif

    If you had, then the powerpc code would have worked ... ;-) and many
    of the other interfaces in include/asm-generic/pgtable.h are
    protected that way ...

Given that some architecture already define pmd_write() as a macro, it's
a net reduction to drop the definition of __HAVE_ARCH_PMD_WRITE.

Link: http://lkml.kernel.org/r/151129126721.37405.13339850900081557813.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Suggested-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Oliver OHalloran <oliveroh@au1.ibm.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-29 18:40:42 -08:00
Dan Williams
1501899a89 mm: fix device-dax pud write-faults triggered by get_user_pages()
Currently only get_user_pages_fast() can safely handle the writable gup
case due to its use of pud_access_permitted() to check whether the pud
entry is writable.  In the gup slow path pud_write() is used instead of
pud_access_permitted() and to date it has been unimplemented, just calls
BUG_ON().

    kernel BUG at ./include/linux/hugetlb.h:244!
    [..]
    RIP: 0010:follow_devmap_pud+0x482/0x490
    [..]
    Call Trace:
     follow_page_mask+0x28c/0x6e0
     __get_user_pages+0xe4/0x6c0
     get_user_pages_unlocked+0x130/0x1b0
     get_user_pages_fast+0x89/0xb0
     iov_iter_get_pages_alloc+0x114/0x4a0
     nfs_direct_read_schedule_iovec+0xd2/0x350
     ? nfs_start_io_direct+0x63/0x70
     nfs_file_direct_read+0x1e0/0x250
     nfs_file_read+0x90/0xc0

For now this just implements a simple check for the _PAGE_RW bit similar
to pmd_write.  However, this implies that the gup-slow-path check is
missing the extra checks that the gup-fast-path performs with
pud_access_permitted.  Later patches will align all checks to use the
'access_permitted' helper if the architecture provides it.

Note that the generic 'access_permitted' helper fallback is the simple
_PAGE_RW check on architectures that do not define the
'access_permitted' helper(s).

[dan.j.williams@intel.com: fix powerpc compile error]
  Link: http://lkml.kernel.org/r/151129126165.37405.16031785266675461397.stgit@dwillia2-desk3.amr.corp.intel.com
Link: http://lkml.kernel.org/r/151043109938.2842.14834662818213616199.stgit@dwillia2-desk3.amr.corp.intel.com
Fixes: a00cc7d9dd ("mm, x86: add support for PUD-sized transparent hugepages")
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Thomas Gleixner <tglx@linutronix.de>	[x86]
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-29 18:40:42 -08:00
Chunyu Hu
55d2d0ad2f x86/idt: Load idt early in start_secondary
On a secondary, idt is first loaded in cpu_init() with load_current_idt(),
i.e. no exceptions can be handled before that point.

The conversion of WARN() to use UD requires the IDT being loaded earlier as
any warning between start_secondary() and load_curren_idt() in cpu_init()
will result in an unhandled @UD exception and therefore fail the bringup of
the CPU.

Install the IDT handlers right in start_secondary() before calling cpu_init().

[ tglx: Massaged changelog ]

Fixes: 9a93848fe7 ("x86/debug: Implement __WARN() using UD0")
Signed-off-by: Chunyu Hu <chuhu@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Cc: peterz@infradead.org
Cc: bp@alien8.de
Cc: rostedt@goodmis.org
Cc: luto@kernel.org
Link: https://lkml.kernel.org/r/1511792499-4073-1-git-send-email-chuhu@redhat.com
2017-11-28 08:15:40 +01:00
Juergen Gross
42b3a4cb56 x86/xen: Support early interrupts in xen pv guests
Add early interrupt handlers activated by idt_setup_early_handler() to
the handlers supported by Xen pv guests. This will allow for early
WARN() calls not crashing the guest.

Suggested-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: xen-devel@lists.xenproject.org
Cc: boris.ostrovsky@oracle.com
Link: https://lkml.kernel.org/r/20171124084221.30172-1-jgross@suse.com
2017-11-28 00:28:56 +01:00
Jan H. Schönherr
20b7035c66 KVM: Let KVM_SET_SIGNAL_MASK work as advertised
KVM API says for the signal mask you set via KVM_SET_SIGNAL_MASK, that
"any unblocked signal received [...] will cause KVM_RUN to return with
-EINTR" and that "the signal will only be delivered if not blocked by
the original signal mask".

This, however, is only true, when the calling task has a signal handler
registered for a signal. If not, signal evaluation is short-circuited for
SIG_IGN and SIG_DFL, and the signal is either ignored without KVM_RUN
returning or the whole process is terminated.

Make KVM_SET_SIGNAL_MASK behave as advertised by utilizing logic similar
to that in do_sigtimedwait() to avoid short-circuiting of signals.

Signed-off-by: Jan H. Schönherr <jschoenh@amazon.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-11-27 17:53:47 +01:00
Wanpeng Li
b74558259c KVM: VMX: Fix vmx->nested freeing when no SMI handler
Reported by syzkaller:

   ------------[ cut here ]------------
   WARNING: CPU: 5 PID: 2939 at arch/x86/kvm/vmx.c:3844 free_loaded_vmcs+0x77/0x80 [kvm_intel]
   CPU: 5 PID: 2939 Comm: repro Not tainted 4.14.0+ #26
   RIP: 0010:free_loaded_vmcs+0x77/0x80 [kvm_intel]
   Call Trace:
    vmx_free_vcpu+0xda/0x130 [kvm_intel]
    kvm_arch_destroy_vm+0x192/0x290 [kvm]
    kvm_put_kvm+0x262/0x560 [kvm]
    kvm_vm_release+0x2c/0x30 [kvm]
    __fput+0x190/0x370
    task_work_run+0xa1/0xd0
    do_exit+0x4d2/0x13e0
    do_group_exit+0x89/0x140
    get_signal+0x318/0xb80
    do_signal+0x8c/0xb40
    exit_to_usermode_loop+0xe4/0x140
    syscall_return_slowpath+0x206/0x230
    entry_SYSCALL_64_fastpath+0x98/0x9a

The syzkaller testcase will execute VMXON/VMLAUCH instructions, so the
vmx->nested stuff is populated, it will also issue KVM_SMI ioctl. However,
the testcase is just a simple c program and not be lauched by something
like seabios which implements smi_handler. Commit 05cade71cf (KVM: nSVM:
fix SMI injection in guest mode) gets out of guest mode and set nested.vmxon
to false for the duration of SMM according to SDM 34.14.1 "leave VMX
operation" upon entering SMM. We can't alloc/free the vmx->nested stuff
each time when entering/exiting SMM since it will induce more overhead. So
the function vmx_pre_enter_smm() marks nested.vmxon false even if vmx->nested
stuff is still populated. What it expected is em_rsm() can mark nested.vmxon
to be true again. However, the smi_handler/rsm will not execute since there
is no something like seabios in this scenario. The function free_nested()
fails to free the vmx->nested stuff since the vmx->nested.vmxon is false
which results in the above warning.

This patch fixes it by also considering the no SMI handler case, luckily
vmx->nested.smm.vmxon is marked according to the value of vmx->nested.vmxon
in vmx_pre_enter_smm(), we can take advantage of it and free vmx->nested
stuff when L1 goes down.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Liran Alon <liran.alon@oracle.com>
Fixes: 05cade71cf (KVM: nSVM: fix SMI injection in guest mode)
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-11-27 17:37:55 +01:00
Wanpeng Li
c37c28730b KVM: VMX: Fix rflags cache during vCPU reset
Reported by syzkaller:

   *** Guest State ***
   CR0: actual=0x0000000080010031, shadow=0x0000000060000010, gh_mask=fffffffffffffff7
   CR4: actual=0x0000000000002061, shadow=0x0000000000000000, gh_mask=ffffffffffffe8f1
   CR3 = 0x000000002081e000
   RSP = 0x000000000000fffa  RIP = 0x0000000000000000
   RFLAGS=0x00023000         DR7 = 0x00000000000000
          ^^^^^^^^^^
   ------------[ cut here ]------------
   WARNING: CPU: 6 PID: 24431 at /home/kernel/linux/arch/x86/kvm//x86.c:7302 kvm_arch_vcpu_ioctl_run+0x651/0x2ea0 [kvm]
   CPU: 6 PID: 24431 Comm: reprotest Tainted: G        W  OE   4.14.0+ #26
   RIP: 0010:kvm_arch_vcpu_ioctl_run+0x651/0x2ea0 [kvm]
   RSP: 0018:ffff880291d179e0 EFLAGS: 00010202
   Call Trace:
    kvm_vcpu_ioctl+0x479/0x880 [kvm]
    do_vfs_ioctl+0x142/0x9a0
    SyS_ioctl+0x74/0x80
    entry_SYSCALL_64_fastpath+0x23/0x9a

The failed vmentry is triggered by the following beautified testcase:

    #include <unistd.h>
    #include <sys/syscall.h>
    #include <string.h>
    #include <stdint.h>
    #include <linux/kvm.h>
    #include <fcntl.h>
    #include <sys/ioctl.h>

    long r[5];
    int main()
    {
        struct kvm_debugregs dr = { 0 };

        r[2] = open("/dev/kvm", O_RDONLY);
        r[3] = ioctl(r[2], KVM_CREATE_VM, 0);
        r[4] = ioctl(r[3], KVM_CREATE_VCPU, 7);
        struct kvm_guest_debug debug = {
                .control = 0xf0403,
                .arch = {
                        .debugreg[6] = 0x2,
                        .debugreg[7] = 0x2
                }
        };
        ioctl(r[4], KVM_SET_GUEST_DEBUG, &debug);
        ioctl(r[4], KVM_RUN, 0);
    }

which testcase tries to setup the processor specific debug
registers and configure vCPU for handling guest debug events through
KVM_SET_GUEST_DEBUG.  The KVM_SET_GUEST_DEBUG ioctl will get and set
rflags in order to set TF bit if single step is needed. All regs' caches
are reset to avail and GUEST_RFLAGS vmcs field is reset to 0x2 during vCPU
reset. However, the cache of rflags is not reset during vCPU reset. The
function vmx_get_rflags() returns an unreset rflags cache value since
the cache is marked avail, it is 0 after boot. Vmentry fails if the
rflags reserved bit 1 is 0.

This patch fixes it by resetting both the GUEST_RFLAGS vmcs field and
its cache to 0x2 during vCPU reset.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Tested-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-11-27 17:37:46 +01:00
Wanpeng Li
e70b57a6ce KVM: X86: Fix softlockup when get the current kvmclock
watchdog: BUG: soft lockup - CPU#6 stuck for 22s! [qemu-system-x86:10185]
 CPU: 6 PID: 10185 Comm: qemu-system-x86 Tainted: G           OE   4.14.0-rc4+ #4
 RIP: 0010:kvm_get_time_scale+0x4e/0xa0 [kvm]
 Call Trace:
  get_time_ref_counter+0x5a/0x80 [kvm]
  kvm_hv_process_stimers+0x120/0x5f0 [kvm]
  kvm_arch_vcpu_ioctl_run+0x4b4/0x1690 [kvm]
  kvm_vcpu_ioctl+0x33a/0x620 [kvm]
  do_vfs_ioctl+0xa1/0x5d0
  SyS_ioctl+0x79/0x90
  entry_SYSCALL_64_fastpath+0x1e/0xa9

This can be reproduced when running kvm-unit-tests/hyperv_stimer.flat and
cpu-hotplug stress simultaneously. __this_cpu_read(cpu_tsc_khz) returns 0
(set in kvmclock_cpu_down_prep()) when the pCPU is unhotplug which results
in kvm_get_time_scale() gets into an infinite loop.

This patch fixes it by treating the unhotplug pCPU as not using master clock.

Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-11-27 17:32:53 +01:00
Dr. David Alan Gilbert
12806ba937 KVM: lapic: Fixup LDR on load in x2apic
In x2apic mode the LDR is fixed based on the ID rather
than separately loadable like it was before x2.
When kvm_apic_set_state is called, the base is set, and if
it has the X2APIC_ENABLE flag set then the LDR is calculated;
however that value gets overwritten by the memcpy a few lines
below overwriting it with the value that came from userland.

The symptom is a lack of EOI after loading the state
(e.g. after a QEMU migration) and is due to the EOI bitmap
being wrong due to the incorrect LDR.  This was seen with
a Win2016 guest under Qemu with irqchip=split whose USB mouse
didn't work after a VM migration.

This corresponds to RH bug:
  https://bugzilla.redhat.com/show_bug.cgi?id=1502591

Reported-by: Yiqian Wei <yiwei@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: stable@vger.kernel.org
[Applied fixup from Liran Alon. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-11-27 17:32:53 +01:00
Dr. David Alan Gilbert
e872fa9466 KVM: lapic: Split out x2apic ldr calculation
Split out the ldr calculation from kvm_apic_set_x2apic_id
since we're about to reuse it in the following patch.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-11-27 17:32:52 +01:00
Linus Torvalds
02fc87b117 Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull misc x86 fixes from Ingo Molnar:
 - topology enumeration fixes
 - KASAN fix
 - two entry fixes (not yet the big series related to KASLR)
 - remove obsolete code
 - instruction decoder fix
 - better /dev/mem sanity checks, hopefully working better this time
 - pkeys fixes
 - two ACPI fixes
 - 5-level paging related fixes
 - UMIP fixes that should make application visible faults more debuggable
 - boot fix for weird virtualization environment

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
  x86/decoder: Add new TEST instruction pattern
  x86/PCI: Remove unused HyperTransport interrupt support
  x86/umip: Fix insn_get_code_seg_params()'s return value
  x86/boot/KASLR: Remove unused variable
  x86/entry/64: Add missing irqflags tracing to native_load_gs_index()
  x86/mm/kasan: Don't use vmemmap_populate() to initialize shadow
  x86/entry/64: Fix entry_SYSCALL_64_after_hwframe() IRQ tracing
  x86/pkeys/selftests: Fix protection keys write() warning
  x86/pkeys/selftests: Rename 'si_pkey' to 'siginfo_pkey'
  x86/mpx/selftests: Fix up weird arrays
  x86/pkeys: Update documentation about availability
  x86/umip: Print a warning into the syslog if UMIP-protected instructions are used
  x86/smpboot: Fix __max_logical_packages estimate
  x86/topology: Avoid wasting 128k for package id array
  perf/x86/intel/uncore: Cache logical pkg id in uncore driver
  x86/acpi: Reduce code duplication in mp_override_legacy_irq()
  x86/acpi: Handle SCI interrupts above legacy space gracefully
  x86/boot: Fix boot failure when SMP MP-table is based at 0
  x86/mm: Limit mmap() of /dev/mem to valid physical addresses
  x86/selftests: Add test for mapping placement for 5-level paging
  ...
2017-11-26 14:11:54 -08:00
Linus Torvalds
580e3d552d Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Ingo Molnar:
 "Misc fixes: two PMU driver fixes and a memory leak fix"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/core: Fix memory leak triggered by perf --namespace
  perf/x86/intel/uncore: Add event constraint for BDX PCU
  perf/x86/intel: Hide TSX events when RTM is not supported
2017-11-26 13:41:48 -08:00
Nadav Amit
9d0b62328d x86/tlb: Disable interrupts when changing CR4
CR4 modifications are implemented as RMW operations which update a shadow
variable and write the result to CR4. The RMW operation is protected by
preemption disable, but there is no enforcement or debugging mechanism.

CR4 modifications happen also in interrupt context via
__native_flush_tlb_global(). This implementation does not affect a
interrupted thread context CR4 operation, because the CR4 toggle restores
the original content and does not modify the shadow variable.

So the current situation seems to be safe, but a recent patch tried to add
an actual RMW operation in interrupt context, which will cause subtle
corruptions.

To prevent that and make the CR4 handling future proof:

 - Add a lockdep assertion to __cr4_set() which will catch interrupt
   enabled invocations

 - Disable interrupts in the cr4 manipulator inlines

 - Rename cr4_toggle_bits() to cr4_toggle_bits_irqsoff(). This is called
   from __switch_to_xtra() where interrupts are already disabled and
   performance matters.

All other call sites are not performance critical, so the extra overhead of
an additional local_irq_save/restore() pair is not a problem. If new call
sites care about performance then the necessary _irqsoff() variants can be
added.

[ tglx: Condensed the patch by moving the irq protection inside the
  	manipulator functions. Updated changelog ]

Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Luck <tony.luck@intel.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: nadav.amit@gmail.com
Cc: linux-edac@vger.kernel.org
Link: https://lkml.kernel.org/r/20171125032907.2241-3-namit@vmware.com
2017-11-25 13:28:43 +01:00
Nadav Amit
0c3292ca80 x86/tlb: Refactor CR4 setting and shadow write
Refactor the write to CR4 and its shadow value. This is done in
preparation for the addition of an assertion to check that IRQs are
disabled during CR4 update.

No functional change.

Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: nadav.amit@gmail.com
Cc: Andy Lutomirski <luto@kernel.org>
Cc: linux-edac@vger.kernel.org
Link: https://lkml.kernel.org/r/20171125032907.2241-2-namit@vmware.com
2017-11-25 13:28:43 +01:00
Linus Torvalds
7753ea0964 Trimmed second batch of KVM changes for Linux 4.15
* GICv4 Support for KVM/ARM
 
 All ARM patches were in next-20171113.  I have postponed most x86 fixes
 to 4.15-rc2 and UMIP to 4.16, but there are fixes that would be good to
 have already in 4.15-rc1:
 
 * re-introduce support for CPUs without virtual NMI (cc stable)
   and allow testing of KVM without virtual NMI on available CPUs
 
 * fix long-standing performance issues with assigned devices on AMD
   (cc stable)
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Merge tag 'kvm-4.15-2' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM updates from Radim Krčmář:
 "Trimmed second batch of KVM changes for Linux 4.15:

   - GICv4 Support for KVM/ARM

   - re-introduce support for CPUs without virtual NMI (cc stable) and
     allow testing of KVM without virtual NMI on available CPUs

   - fix long-standing performance issues with assigned devices on AMD
     (cc stable)"

* tag 'kvm-4.15-2' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (30 commits)
  kvm: vmx: Allow disabling virtual NMI support
  kvm: vmx: Reinstate support for CPUs without virtual NMI
  KVM: SVM: obey guest PAT
  KVM: arm/arm64: Don't queue VLPIs on INV/INVALL
  KVM: arm/arm64: Fix GICv4 ITS initialization issues
  KVM: arm/arm64: GICv4: Theory of operations
  KVM: arm/arm64: GICv4: Enable VLPI support
  KVM: arm/arm64: GICv4: Prevent userspace from changing doorbell affinity
  KVM: arm/arm64: GICv4: Prevent a VM using GICv4 from being saved
  KVM: arm/arm64: GICv4: Enable virtual cpuif if VLPIs can be delivered
  KVM: arm/arm64: GICv4: Hook vPE scheduling into vgic flush/sync
  KVM: arm/arm64: GICv4: Use the doorbell interrupt as an unblocking source
  KVM: arm/arm64: GICv4: Add doorbell interrupt handling
  KVM: arm/arm64: GICv4: Use pending_last as a scheduling hint
  KVM: arm/arm64: GICv4: Handle INVALL applied to a vPE
  KVM: arm/arm64: GICv4: Propagate property updates to VLPIs
  KVM: arm/arm64: GICv4: Handle MOVALL applied to a vPE
  KVM: arm/arm64: GICv4: Handle CLEAR applied to a VLPI
  KVM: arm/arm64: GICv4: Propagate affinity changes to the physical ITS
  KVM: arm/arm64: GICv4: Unmap VLPI when freeing an LPI
  ...
2017-11-24 19:44:25 -10:00
Masami Hiramatsu
12a78d43de x86/decoder: Add new TEST instruction pattern
The kbuild test robot reported this build warning:

  Warning: arch/x86/tools/test_get_len found difference at <jump_table>:ffffffff8103dd2c

  Warning: ffffffff8103dd82: f6 09 d8 testb $0xd8,(%rcx)
  Warning: objdump says 3 bytes, but insn_get_length() says 2
  Warning: decoded and checked 1569014 instructions with 1 warnings

This sequence seems to be a new instruction not in the opcode map in the Intel SDM.

The instruction sequence is "F6 09 d8", means Group3(F6), MOD(00)REG(001)RM(001), and 0xd8.
Intel SDM vol2 A.4 Table A-6 said the table index in the group is "Encoding of Bits 5,4,3 of
the ModR/M Byte (bits 2,1,0 in parenthesis)"

In that table, opcodes listed by the index REG bits as:

  000         001       010 011  100        101        110         111
 TEST Ib/Iz,(undefined),NOT,NEG,MUL AL/rAX,IMUL AL/rAX,DIV AL/rAX,IDIV AL/rAX

So, it seems TEST Ib is assigned to 001.

Add the new pattern.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: <stable@vger.kernel.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-11-24 08:36:12 +01:00
Bjorn Helgaas
fd2fa6c18b x86/PCI: Remove unused HyperTransport interrupt support
There are no in-tree callers of ht_create_irq(), the driver interface for
HyperTransport interrupts, left.  Remove the unused entry point and all the
supporting code.

See 8b955b0ddd ("[PATCH] Initial generic hypertransport interrupt
support").

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-pci@vger.kernel.org
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Link: https://lkml.kernel.org/r/20171122221337.3877.23362.stgit@bhelgaas-glaptop.roam.corp.google.com
2017-11-23 20:18:18 +01:00
Borislav Petkov
e2a5dca753 x86/umip: Fix insn_get_code_seg_params()'s return value
In order to save on redundant structs definitions
insn_get_code_seg_params() was made to return two 4-bit values in a char
but clang complains:

  arch/x86/lib/insn-eval.c:780:10: warning: implicit conversion from 'int' to 'char'
	  changes value from 132 to -124 [-Wconstant-conversion]
                  return INSN_CODE_SEG_PARAMS(4, 8);
                  ~~~~~~ ^~~~~~~~~~~~~~~~~~~~~~~~~~
  ./arch/x86/include/asm/insn-eval.h:16:57: note: expanded from macro 'INSN_CODE_SEG_PARAMS'
  #define INSN_CODE_SEG_PARAMS(oper_sz, addr_sz) (oper_sz | (addr_sz << 4))

Those two values do get picked apart afterwards the opposite way of how
they were ORed so wrt to the LSByte, the return value is the same.

But this function returns -EINVAL in the error case, which is an int. So
make it return an int which is the native word size anyway and thus fix
the clang warning.

Reported-by: Kees Cook <keescook@google.com>
Reported-by: Nick Desaulniers <nick.desaulniers@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: ricardo.neri-calderon@linux.intel.com
Link: https://lkml.kernel.org/r/20171123091951.1462-1-bp@alien8.de
2017-11-23 20:17:59 +01:00
Chao Fan
69550d41ff x86/boot/KASLR: Remove unused variable
There are two variables "rc" in mem_avoid_memmap. One at the top of the
function and another one inside the while() loop. Drop the outer one as it
is unused. Cleanup some whitespace damage while at it.

Signed-off-by: Chao Fan <fanc.fnst@cn.fujitsu.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: gregkh@linuxfoundation.org
Cc: n-horiguchi@ah.jp.nec.com
Cc: keescook@chromium.org
Link: https://lkml.kernel.org/r/20171123090847.15293-1-fanc.fnst@cn.fujitsu.com
2017-11-23 20:17:59 +01:00
Andy Lutomirski
ca37e57bbe x86/entry/64: Add missing irqflags tracing to native_load_gs_index()
Running this code with IRQs enabled (where dummy_lock is a spinlock):

static void check_load_gs_index(void)
{
	/* This will fail. */
	load_gs_index(0xffff);

	spin_lock(&dummy_lock);
	spin_unlock(&dummy_lock);
}

Will generate a lockdep warning.  The issue is that the actual write
to %gs would cause an exception with IRQs disabled, and the exception
handler would, as an inadvertent side effect, update irqflag tracing
to reflect the IRQs-off status.  native_load_gs_index() would then
turn IRQs back on and return with irqflag tracing still thinking that
IRQs were off.  The dummy lock-and-unlock causes lockdep to notice the
error and warn.

Fix it by adding the missing tracing.

Apparently nothing did this in a context where it mattered.  I haven't
tried to find a code path that would actually exhibit the warning if
appropriately nasty user code were running.

I suspect that the security impact of this bug is very, very low --
production systems don't run with lockdep enabled, and the warning is
mostly harmless anyway.

Found during a quick audit of the entry code to try to track down an
unrelated bug that Ingo found in some still-in-development code.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/e1aeb0e6ba8dd430ec36c8a35e63b429698b4132.1511411918.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-11-23 07:54:25 +01:00
Andrey Ryabinin
f68d62a567 x86/mm/kasan: Don't use vmemmap_populate() to initialize shadow
[ Note, this commit is a cherry-picked version of:

    d17a1d97dc: ("x86/mm/kasan: don't use vmemmap_populate() to initialize shadow")

  ... for easier x86 entry code testing and back-porting. ]

The KASAN shadow is currently mapped using vmemmap_populate() since that
provides a semi-convenient way to map pages into init_top_pgt.  However,
since that no longer zeroes the mapped pages, it is not suitable for
KASAN, which requires zeroed shadow memory.

Add kasan_populate_shadow() interface and use it instead of
vmemmap_populate().  Besides, this allows us to take advantage of
gigantic pages and use them to populate the shadow, which should save us
some memory wasted on page tables and reduce TLB pressure.

Link: http://lkml.kernel.org/r/20171103185147.2688-2-pasha.tatashin@oracle.com
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Steven Sistare <steven.sistare@oracle.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Bob Picco <bob.picco@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-11-22 07:18:35 +01:00
Andy Lutomirski
548c3050ea x86/entry/64: Fix entry_SYSCALL_64_after_hwframe() IRQ tracing
When I added entry_SYSCALL_64_after_hwframe(), I left TRACE_IRQS_OFF
before it.  This means that users of entry_SYSCALL_64_after_hwframe()
were responsible for invoking TRACE_IRQS_OFF, and the one and only
user (Xen, added in the same commit) got it wrong.

I think this would manifest as a warning if a Xen PV guest with
CONFIG_DEBUG_LOCKDEP=y were used with context tracking.  (The
context tracking bit is to cause lockdep to get invoked before we
turn IRQs back on.)  I haven't tested that for real yet because I
can't get a kernel configured like that to boot at all on Xen PV.

Move TRACE_IRQS_OFF below the label.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Fixes: 8a9949bc71 ("x86/xen/64: Rearrange the SYSCALL entries")
Link: http://lkml.kernel.org/r/9150aac013b7b95d62c2336751d5b6e91d2722aa.1511325444.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-11-22 06:35:48 +01:00
Ricardo Neri
fd11a6496e x86/umip: Print a warning into the syslog if UMIP-protected instructions are used
Print a rate-limited warning when a user-space program attempts to execute
any of the instructions that UMIP protects (i.e., SGDT, SIDT, SLDT, STR
and SMSW).

This is useful, because when CONFIG_X86_INTEL_UMIP=y is selected and
supported by the hardware, user space programs that try to execute such
instructions will receive a SIGSEGV signal that they might not expect.

In the specific cases for which emulation is provided (instructions SGDT,
SIDT and SMSW in protected and virtual-8086 modes), no signal is
generated. However, a warning is helpful to encourage updates in such
programs to avoid the use of such instructions.

Warnings are printed via a customized printk() function that also provides
information about the program that attempted to use the affected
instructions.

Utility macros are defined to wrap umip_printk() for the error and warning
kernel log levels.

While here, replace an existing call to the generic rate-limited pr_err()
with the new umip_pr_err().

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi V. Shankar <ravi.v.shankar@intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: ricardo.neri@intel.com
Link: http://lkml.kernel.org/r/1511233476-17088-1-git-send-email-ricardo.neri-calderon@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-11-21 08:13:43 +01:00
Linus Torvalds
09bd7c75e5 Kbuild updates for v4.15
One of the most remarkable improvements in this cycle is, Kbuild is
 now able to cache the result of shell commands.  Some variables are
 expensive to compute, for example, $(call cc-option,...) invokes the
 compiler.  It is not efficient to redo this computation every time,
 even when we are not actually building anything.  Kbuild creates a
 hidden file ".cache.mk" that contains invoked shell commands and
 their results.  The speed-up should be noticeable.
 
 Summary:
 
 - Fix arch build issues (hexagon, sh)
 
 - Clean up various Makefiles and scripts
 
 - Fix wrong usage of {CFLAGS,LDFLAGS}_MODULE in arch Makefiles
 
 - Cache variables that are expensive to compute
 
 - Improve cc-ldopton and ld-option for Clang
 
 - Optimize output directory creation
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Merge tag 'kbuild-v4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:
 "One of the most remarkable improvements in this cycle is, Kbuild is
  now able to cache the result of shell commands. Some variables are
  expensive to compute, for example, $(call cc-option,...) invokes the
  compiler. It is not efficient to redo this computation every time,
  even when we are not actually building anything. Kbuild creates a
  hidden file ".cache.mk" that contains invoked shell commands and their
  results. The speed-up should be noticeable.

  Summary:

   - Fix arch build issues (hexagon, sh)

   - Clean up various Makefiles and scripts

   - Fix wrong usage of {CFLAGS,LDFLAGS}_MODULE in arch Makefiles

   - Cache variables that are expensive to compute

   - Improve cc-ldopton and ld-option for Clang

   - Optimize output directory creation"

* tag 'kbuild-v4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (30 commits)
  kbuild: move coccicheck help from scripts/Makefile.help to top Makefile
  sh: decompressor: add shipped files to .gitignore
  frv: .gitignore: ignore vmlinux.lds
  selinux: remove unnecessary assignment to subdir-
  kbuild: specify FORCE in Makefile.headersinst as .PHONY target
  kbuild: remove redundant mkdir from ./Kbuild
  kbuild: optimize object directory creation for incremental build
  kbuild: create object directories simpler and faster
  kbuild: filter-out PHONY targets from "targets"
  kbuild: remove redundant $(wildcard ...) for cmd_files calculation
  kbuild: create directory for make cache only when necessary
  sh: select KBUILD_DEFCONFIG depending on ARCH
  kbuild: fix linker feature test macros when cross compiling with Clang
  kbuild: shrink .cache.mk when it exceeds 1000 lines
  kbuild: do not call cc-option before KBUILD_CFLAGS initialization
  kbuild: Cache a few more calls to the compiler
  kbuild: Add a cache for generated variables
  kbuild: add forward declaration of default target to Makefile.asm-generic
  kbuild: remove KBUILD_SUBDIR_ASFLAGS and KBUILD_SUBDIR_CCFLAGS
  hexagon/kbuild: replace CFLAGS_MODULE with KBUILD_CFLAGS_MODULE
  ...
2017-11-17 17:45:29 -08:00
Linus Torvalds
e75080f185 Two power management fixes for v4.15-rc1
This is the change making /proc/cpuinfo on x86 report current
 CPU frequency in "cpu MHz" again in all cases and an additional
 one dealing with an overzealous check in one of the helper
 routines in the runtime PM framework.
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Merge tag 'pm-fixes-4.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull two power management fixes from Rafael Wysocki:
 "This is the change making /proc/cpuinfo on x86 report current CPU
  frequency in "cpu MHz" again in all cases and an additional one
  dealing with an overzealous check in one of the helper routines in the
  runtime PM framework"

* tag 'pm-fixes-4.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  PM / runtime: Drop children check from __pm_runtime_set_status()
  x86 / CPU: Always show current CPU frequency in /proc/cpuinfo
2017-11-17 14:49:25 -08:00
Linus Torvalds
5a3e0b196b File locking related changes for v4.15
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Merge tag 'locks-v4.15-1' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux

Pull file locking update from Jeff Layton:
 "A couple of fixes for a patch that went into v4.14, and the bug report
  just came in a few days ago.. It passes my (minimal) testing, and has
  been in linux-next for a few days now.

  I also would like to get my address changed in MAINTAINERS to clear
  that hurdle"

* tag 'locks-v4.15-1' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux:
  fcntl: don't cap l_start and l_end values for F_GETLK64 in compat syscall
  fcntl: don't leak fd reference when fixup_compat_flock fails
  MAINTAINERS: s/jlayton@poochiereds.net/jlayton@kernel.org/
2017-11-17 13:21:58 -08:00