Re: Linux 5.7.4

From: Greg Kroah-Hartman
Date: Thu Jun 18 2020 - 08:50:37 EST


diff --git a/Makefile b/Makefile
index a2ce556f4347..64da771d4ac5 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
# SPDX-License-Identifier: GPL-2.0
VERSION = 5
PATCHLEVEL = 7
-SUBLEVEL = 3
+SUBLEVEL = 4
EXTRAVERSION =
NAME = Kleptomaniac Octopus

diff --git a/lib/vdso/gettimeofday.c b/lib/vdso/gettimeofday.c
index a2909af4b924..3bb82a6cc5aa 100644
--- a/lib/vdso/gettimeofday.c
+++ b/lib/vdso/gettimeofday.c
@@ -38,6 +38,13 @@ static inline bool vdso_clocksource_ok(const struct vdso_data *vd)
}
#endif

+#ifndef vdso_cycles_ok
+static inline bool vdso_cycles_ok(u64 cycles)
+{
+ return true;
+}
+#endif
+
#ifdef CONFIG_TIME_NS
static int do_hres_timens(const struct vdso_data *vdns, clockid_t clk,
struct __kernel_timespec *ts)
@@ -62,6 +69,8 @@ static int do_hres_timens(const struct vdso_data *vdns, clockid_t clk,
return -1;

cycles = __arch_get_hw_counter(vd->clock_mode);
+ if (unlikely(!vdso_cycles_ok(cycles)))
+ return -1;
ns = vdso_ts->nsec;
last = vd->cycle_last;
ns += vdso_calc_delta(cycles, last, vd->mask, vd->mult);
@@ -130,6 +139,8 @@ static __always_inline int do_hres(const struct vdso_data *vd, clockid_t clk,
return -1;

cycles = __arch_get_hw_counter(vd->clock_mode);
+ if (unlikely(!vdso_cycles_ok(cycles)))
+ return -1;
ns = vdso_ts->nsec;
last = vd->cycle_last;
ns += vdso_calc_delta(cycles, last, vd->mask, vd->mult);