| Message ID | 1372198807-19138-1-git-send-email-kamal@canonical.com |
|---|---|
| State | New |
| Headers | show |
diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c index 5bedbdd..a855a2e 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;
This is a note to let you know that I have just added a patch titled x86: kvmclock: zero initialize pvclock shared memory area to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue This patch is scheduled to be released in version 3.8.13.4. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.8.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Kamal ------ From 0a3387fd602f90aa2692cae49735155b9fb87233 Mon Sep 17 00:00:00 2001 From: Igor Mammedov <imammedo@redhat.com> Date: Mon, 10 Jun 2013 18:31:11 +0200 Subject: 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: Kamal Mostafa <kamal@canonical.com> --- arch/x86/kernel/kvmclock.c | 1 + 1 file changed, 1 insertion(+) -- 1.8.1.2