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authorCornelia Huck <cohuck@redhat.com>2019-11-27 11:43:25 +0100
committerCornelia Huck <cohuck@redhat.com>2019-12-14 10:25:50 +0100
commit5c6096e5656d34f5414834e2e2104646294976fe (patch)
treea2074ffa2e47a353f385d079bf5c343ab7dea64e /qga
parentbcf88d56efec4ffc153bbe98d11b689a5ebe1a91 (diff)
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 <lersek@redhat.com> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com> Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com> Message-Id: <20191205115350.18713-1-cohuck@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Diffstat (limited to 'qga')
-rw-r--r--qga/commands-posix.c13
1 files changed, 12 insertions, 1 deletions
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) {