[PATCH] xen/time: Fix incorrect per_cpu accessor in xen_clocksource_read()

[PATCH] xen/time: Fix incorrect per_cpu accessor in xen_clocksource_read()

[Boris Ostrovsky]

Commit 89cbc76768c2 ("x86: Replace __get_cpu_var uses") replaced
__get_cpu_var() with this_cpu_ptr() in xen_clocksource_read() in such a
way that instead of accessing a structure pointed to by a per-cpu pointer
we are trying to get to a per-cpu structure.

__this_cpu_read() of the pointer is the more appropriate accessor.

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
---
 arch/x86/xen/time.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c
index a1d430b..f473d26 100644
--- a/arch/x86/xen/time.c
+++ b/arch/x86/xen/time.c
@@ -158,7 +158,7 @@ cycle_t xen_clocksource_read(void)
 	cycle_t ret;
 
 	preempt_disable_notrace();
-	src = this_cpu_ptr(&xen_vcpu->time);
+	src = &__this_cpu_read(xen_vcpu)->time;
 	ret = pvclock_clocksource_read(src);
 	preempt_enable_notrace();
 	return ret;
-- 
1.8.1.4

Re: [Xen-devel] [PATCH] xen/time: Fix incorrect per_cpu accessor in xen_clocksource_read()

[David Vrabel]

On 16/10/14 22:02, Boris Ostrovsky wrote:
> Commit 89cbc76768c2 ("x86: Replace __get_cpu_var uses") replaced
> __get_cpu_var() with this_cpu_ptr() in xen_clocksource_read() in such a
> way that instead of accessing a structure pointed to by a per-cpu pointer
> we are trying to get to a per-cpu structure.
> 
> __this_cpu_read() of the pointer is the more appropriate accessor.

Applied, thanks.

David