From: Chiawei Wang chiaweiwang@google.com
CLOCK_REALTIME in vdso data won't be updated if __arch_use_vsyscall() returns false. It will let time() return an incorrect time value. Since time() is designed to return the seconds since the Epoch, using CLOCK_REALTIME_COARSE can still fulfill the request and never fails.
Signed-off-by: Chiawei Wang chiaweiwang@google.com Signed-off-by: Mark Salyzyn salyzyn@android.com Cc: linux-kernel@vger.kernel.org Cc: kernel-team@android.com Cc: stable@vger.kernel.org # 5.4+ --- lib/vdso/gettimeofday.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/lib/vdso/gettimeofday.c b/lib/vdso/gettimeofday.c index a2909af4b924..7ea22096cbe2 100644 --- a/lib/vdso/gettimeofday.c +++ b/lib/vdso/gettimeofday.c @@ -324,7 +324,7 @@ __cvdso_time_data(const struct vdso_data *vd, __kernel_old_time_t *time) vd->clock_mode == VDSO_CLOCKMODE_TIMENS) vd = __arch_get_timens_vdso_data();
- t = READ_ONCE(vd[CS_HRES_COARSE].basetime[CLOCK_REALTIME].sec); + t = READ_ONCE(vd[CS_HRES_COARSE].basetime[CLOCK_REALTIME_COARSE].sec);
if (time) *time = t;