From: Cornelia Huck Date: Wed, 27 Nov 2019 10:43:25 +0000 (+0100) Subject: qga: fence guest-set-time if hwclock not available X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=5c6096e5656d34f5414834e2e2104646294976fe;p=qemu.git qga: fence guest-set-time if hwclock not available The Posix implementation of guest-set-time invokes hwclock to set/retrieve the time to/from the hardware clock. If hwclock is not available, the user is currently informed that "hwclock failed to set hardware clock to system time", which is quite misleading. This may happen e.g. on s390x, which has a different timekeeping concept anyway. Let's check for the availability of the hwclock command and return QERR_UNSUPPORTED for guest-set-time if it is not available. Reviewed-by: Laszlo Ersek Reviewed-by: Daniel P. Berrangé Reviewed-by: Michael Roth Message-Id: <20191205115350.18713-1-cohuck@redhat.com> Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: Cornelia Huck --- diff --git a/qga/commands-posix.c b/qga/commands-posix.c index 1c1a165dae..0be301a4ea 100644 --- a/qga/commands-posix.c +++ b/qga/commands-posix.c @@ -156,6 +156,17 @@ void qmp_guest_set_time(bool has_time, int64_t time_ns, Error **errp) pid_t pid; Error *local_err = NULL; struct timeval tv; + static const char hwclock_path[] = "/sbin/hwclock"; + static int hwclock_available = -1; + + if (hwclock_available < 0) { + hwclock_available = (access(hwclock_path, X_OK) == 0); + } + + if (!hwclock_available) { + error_setg(errp, QERR_UNSUPPORTED); + return; + } /* If user has passed a time, validate and set it. */ if (has_time) { @@ -195,7 +206,7 @@ void qmp_guest_set_time(bool has_time, int64_t time_ns, Error **errp) /* Use '/sbin/hwclock -w' to set RTC from the system time, * or '/sbin/hwclock -s' to set the system time from RTC. */ - execle("/sbin/hwclock", "hwclock", has_time ? "-w" : "-s", + execle(hwclock_path, "hwclock", has_time ? "-w" : "-s", NULL, environ); _exit(EXIT_FAILURE); } else if (pid < 0) {