diff --git a/coregrind/m_syswrap/syswrap-linux.c b/coregrind/m_syswrap/syswrap-linux.c
index 2336c29..0f8e07a 100644
--- a/coregrind/m_syswrap/syswrap-linux.c
+++ b/coregrind/m_syswrap/syswrap-linux.c
@@ -5277,8 +5277,25 @@ PRE(sys_utimensat)
int, dfd, char *, filename, struct timespec *, utimes, int, flags);
if (ARG2 != 0)
PRE_MEM_RASCIIZ( "utimensat(filename)", ARG2 );
- if (ARG3 != 0)
- PRE_MEM_READ( "utimensat(tvp)", ARG3, 2 * sizeof(struct vki_timespec) );
+ if (ARG3 != 0) {
+ /* If timespec.tv_nsec has the special value UTIME_NOW or UTIME_OMIT
+ then the tv_sec field is ignored. */
+ struct vki_timespec *times = (struct vki_timespec *)(Addr)ARG3;
+ PRE_MEM_READ( "utimensat(times[0].tv_nsec)",
+ (Addr)×[0].tv_nsec, sizeof(times[0].tv_nsec));
+ PRE_MEM_READ( "utimensat(times[1].tv_nsec)",
+ (Addr)×[1].tv_nsec, sizeof(times[1].tv_nsec));
+ if (ML_(safe_to_deref)(times, 2 * sizeof(struct vki_timespec))) {
+ if (times[0].tv_nsec != VKI_UTIME_NOW
+ && times[0].tv_nsec != VKI_UTIME_OMIT)
+ PRE_MEM_READ( "utimensat(times[0].tv_sec)",
+ (Addr)×[0].tv_sec, sizeof(times[0].tv_sec));
+ if (times[1].tv_nsec != VKI_UTIME_NOW
+ && times[1].tv_nsec != VKI_UTIME_OMIT)
+ PRE_MEM_READ( "utimensat(times[1].tv_sec)",
+ (Addr)×[1].tv_sec, sizeof(times[1].tv_sec));
+ }
+ }
}
PRE(sys_newfstatat)
diff --git a/include/vki/vki-linux.h b/include/vki/vki-linux.h
index 7072080..bf0c1aa 100644
--- a/include/vki/vki-linux.h
+++ b/include/vki/vki-linux.h
@@ -283,6 +283,10 @@ struct vki_timespec {
long tv_nsec; /* nanoseconds */
};
+/* Special values for vki_timespec.tv_nsec when used with utimensat. */
+#define VKI_UTIME_NOW ((1l << 30) - 1l)
+#define VKI_UTIME_OMIT ((1l << 30) - 2l)
+
struct vki_timeval {
vki_time_t tv_sec; /* seconds */
vki_suseconds_t tv_usec; /* microseconds */