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-rw-r--r--include/vdso/datapage.h19
1 files changed, 18 insertions, 1 deletions
diff --git a/include/vdso/datapage.h b/include/vdso/datapage.h
index 2e302c0f41f7..c5f347cc5e55 100644
--- a/include/vdso/datapage.h
+++ b/include/vdso/datapage.h
@@ -21,6 +21,8 @@
#define CS_RAW 1
#define CS_BASES (CS_RAW + 1)
+#define VCLOCK_TIMENS UINT_MAX
+
/**
* struct vdso_timestamp - basetime per clock_id
* @sec: seconds
@@ -48,6 +50,7 @@ struct vdso_timestamp {
* @mult: clocksource multiplier
* @shift: clocksource shift
* @basetime[clock_id]: basetime per clock_id
+ * @offset[clock_id]: time namespace offset per clock_id
* @tz_minuteswest: minutes west of Greenwich
* @tz_dsttime: type of DST correction
* @hrtimer_res: hrtimer resolution
@@ -55,6 +58,17 @@ struct vdso_timestamp {
*
* vdso_data will be accessed by 64 bit and compat code at the same time
* so we should be careful before modifying this structure.
+ *
+ * @basetime is used to store the base time for the system wide time getter
+ * VVAR page.
+ *
+ * @offset is used by the special time namespace VVAR pages which are
+ * installed instead of the real VVAR page. These namespace pages must set
+ * @seq to 1 and @clock_mode to VLOCK_TIMENS to force the code into the
+ * time namespace slow path. The namespace aware functions retrieve the
+ * real system wide VVAR page, read host time and add the per clock offset.
+ * For clocks which are not affected by time namespace adjustment the
+ * offset must be zero.
*/
struct vdso_data {
u32 seq;
@@ -65,7 +79,10 @@ struct vdso_data {
u32 mult;
u32 shift;
- struct vdso_timestamp basetime[VDSO_BASES];
+ union {
+ struct vdso_timestamp basetime[VDSO_BASES];
+ struct timens_offset offset[VDSO_BASES];
+ };
s32 tz_minuteswest;
s32 tz_dsttime;