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  1. 14 12月, 2017 18 次提交
  3. 09 12月, 2017 1 次提交
  5. 07 12月, 2017 2 次提交
    • A
      x86/vdso: Change time() prototype to match __vdso_time() · 88edb57d
      由 Arnd Bergmann 提交于 
      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: NArnd Bergmann <arnd@arndb.de>
Acked-by: NThomas 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.deSigned-off-by: NIngo Molnar <mingo@kernel.org>
      88edb57d
    • C
      x86: Fix Sparse warnings about non-static functions · d553d03f
      由 Colin Ian King 提交于 
      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: NColin Ian King <colin.king@canonical.com>
Acked-by: NMike 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.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      d553d03f
  7. 06 12月, 2017 11 次提交
  9. 05 12月, 2017 1 次提交
    • H
      bpf: correct broken uapi for BPF_PROG_TYPE_PERF_EVENT program type · c895f6f7
      由 Hendrik Brueckner 提交于 
      Commit 0515e599 ("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: NThomas Richter <tmricht@linux.vnet.ibm.com>
Fixes: 0515e599 ("bpf: introduce BPF_PROG_TYPE_PERF_EVENT program type")
Signed-off-by: NHendrik Brueckner <brueckner@linux.vnet.ibm.com>
Reviewed-and-tested-by: NThomas Richter <tmricht@linux.vnet.ibm.com>
Acked-by: NAlexei 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: NDaniel Borkmann <daniel@iogearbox.net>
      c895f6f7
  11. 30 11月, 2017 2 次提交
  13. 28 11月, 2017 5 次提交
    • C
      x86/idt: Load idt early in start_secondary · 55d2d0ad
      由 Chunyu Hu 提交于 
      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: 9a93848f ("x86/debug: Implement __WARN() using UD0")
Signed-off-by: NChunyu Hu <chuhu@redhat.com>
Signed-off-by: NThomas 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
      55d2d0ad
    • J
      x86/xen: Support early interrupts in xen pv guests · 42b3a4cb
      由 Juergen Gross 提交于 
      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: NAndy Lutomirski <luto@kernel.org>
Signed-off-by: NJuergen Gross <jgross@suse.com>
Signed-off-by: NThomas 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
      42b3a4cb
    • J
      KVM: Let KVM_SET_SIGNAL_MASK work as advertised · 20b7035c
      由 Jan H. Schönherr 提交于 
      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: NJan H. Schönherr <jschoenh@amazon.de>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      20b7035c
    • W
      KVM: VMX: Fix vmx->nested freeing when no SMI handler · b7455825
      由 Wanpeng Li 提交于 
      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 05cade71 (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: NDmitry Vyukov <dvyukov@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: NLiran Alon <liran.alon@oracle.com>
Fixes: 05cade71 (KVM: nSVM: fix SMI injection in guest mode)
Signed-off-by: NWanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      b7455825
    • W
      KVM: VMX: Fix rflags cache during vCPU reset · c37c2873
      由 Wanpeng Li 提交于 
      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: NDmitry Vyukov <dvyukov@google.com>
Tested-by: NDmitry Vyukov <dvyukov@google.com>
Reviewed-by: NDavid 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: NWanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      c37c2873