diff options
| author | Igor Mammedov <imammedo@redhat.com> | 2013-06-10 18:31:11 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-06-27 10:38:44 -0700 |
| commit | 65f918123bd108a9b50bceaf4b32ac173b9e3f3e (patch) | |
| tree | 7e3e3207ee50430dd6aa72a11ee81972e7f9ef9f /arch | |
| parent | 5440f5d68b518339a9ee2fdc838c8caef19e36de (diff) | |
x86: kvmclock: zero initialize pvclock shared memory area
commit 07868fc6aaf57847b0f3a3d53086b7556eb83f4a upstream.
kernel might hung in pvclock_clocksource_read() due to
uninitialized memory might contain odd version value in
following cycle:
do {
version = __pvclock_read_cycles(src, &ret, &flags);
} while ((src->version & 1) || version != src->version);
if secondary kvmclock is accessed before it's registered with kvm.
Clear garbage in pvclock shared memory area right after it's
allocated to avoid this issue.
Ref: https://bugzilla.kernel.org/show_bug.cgi?id=59521
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
[See BZ for analysis. We may want a different fix for 3.11, but
this is the safest for now - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kernel/kvmclock.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c index 0732f0089a3d..1590a3a88b77 100644 --- a/arch/x86/kernel/kvmclock.c +++ b/arch/x86/kernel/kvmclock.c @@ -238,6 +238,7 @@ void __init kvmclock_init(void) if (!mem) return; hv_clock = __va(mem); + memset(hv_clock, 0, size); if (kvm_register_clock("boot clock")) { hv_clock = NULL; |