Messages in this thread Patch in this message | | | From | Igor Mammedov <> | Subject | [PATCH] x86: kvmclock: zero initialize pvclock shared memory area | Date | Mon, 10 Jun 2013 18:31:11 +0200 |
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=== Could be the following an acceptable fix? ===
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> --- 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 d2c3812..3dd37eb 100644 --- a/arch/x86/kernel/kvmclock.c +++ b/arch/x86/kernel/kvmclock.c @@ -242,6 +242,7 @@ 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; -- 1.7.1
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