diff options
author | Lennart Poettering <lennart@poettering.net> | 2016-04-20 18:12:57 +0200 |
---|---|---|
committer | Sven Eden <yamakuzure@gmx.net> | 2017-06-16 10:12:58 +0200 |
commit | 99d43b8fa4059271600d7b86e55224ce4309430d (patch) | |
tree | 67c627888c436edff2dfb696a2366914d4502603 /src | |
parent | 888475ce4027042053b890f10f346946c9d6cf7b (diff) |
tree-wide: don't assume CLOCK_BOOTIME is generally available
Before we invoke now(CLOCK_BOOTTIME), let's make sure we actually have that
clock, since now() will otherwise hit an assert.
Specifically, let's refuse CLOCK_BOOTTIME early in sd-event if the kernel
doesn't actually support it.
This is a follow-up for #3037, and specifically:
https://github.com/elogind/elogind/pull/3037#issuecomment-210199167
Diffstat (limited to 'src')
-rw-r--r-- | src/basic/time-util.c | 37 | ||||
-rw-r--r-- | src/libelogind/sd-event/sd-event.c | 10 |
2 files changed, 32 insertions, 15 deletions
diff --git a/src/basic/time-util.c b/src/basic/time-util.c index f2c245e7c..2a3957d97 100644 --- a/src/basic/time-util.c +++ b/src/basic/time-util.c @@ -1075,22 +1075,31 @@ bool timezone_is_valid(const char *name) { return true; } -clockid_t clock_boottime_or_monotonic(void) { - static clockid_t clock = -1; - int fd; - - if (clock != -1) - return clock; - - fd = timerfd_create(CLOCK_BOOTTIME, TFD_NONBLOCK|TFD_CLOEXEC); - if (fd < 0) - clock = CLOCK_MONOTONIC; - else { - safe_close(fd); - clock = CLOCK_BOOTTIME; +bool clock_boottime_supported(void) { + static int supported = -1; + + /* Note that this checks whether CLOCK_BOOTTIME is available in general as well as available for timerfds()! */ + + if (supported < 0) { + int fd; + + fd = timerfd_create(CLOCK_BOOTTIME, TFD_NONBLOCK|TFD_CLOEXEC); + if (fd < 0) + supported = false; + else { + safe_close(fd); + supported = true; + } } - return clock; + return supported; +} + +clockid_t clock_boottime_or_monotonic(void) { + if (clock_boottime_supported()) + return CLOCK_BOOTTIME; + else + return CLOCK_MONOTONIC; } int get_timezone(char **tz) { diff --git a/src/libelogind/sd-event/sd-event.c b/src/libelogind/sd-event/sd-event.c index 52ecb8701..d76f01b7d 100644 --- a/src/libelogind/sd-event/sd-event.c +++ b/src/libelogind/sd-event/sd-event.c @@ -1074,6 +1074,10 @@ _public_ int sd_event_add_time( assert_return(e->state != SD_EVENT_FINISHED, -ESTALE); assert_return(!event_pid_changed(e), -ECHILD); + if (IN_SET(clock, CLOCK_BOOTTIME, CLOCK_BOOTTIME_ALARM) && + !clock_boottime_supported()) + return -EOPNOTSUPP; + if (!callback) callback = time_exit_callback; @@ -2547,7 +2551,8 @@ _public_ int sd_event_wait(sd_event *e, uint64_t timeout) { } dual_timestamp_get(&e->timestamp); - e->timestamp_boottime = now(clock_boottime_or_monotonic()); + if (clock_boottime_supported()) + e->timestamp_boottime = now(CLOCK_BOOTTIME); for (i = 0; i < m; i++) { @@ -2786,6 +2791,9 @@ _public_ int sd_event_now(sd_event *e, clockid_t clock, uint64_t *usec) { CLOCK_BOOTTIME, CLOCK_BOOTTIME_ALARM), -EOPNOTSUPP); + if (IN_SET(clock, CLOCK_BOOTTIME, CLOCK_BOOTTIME_ALARM) && !clock_boottime_supported()) + return -EOPNOTSUPP; + if (!dual_timestamp_is_set(&e->timestamp)) { /* Implicitly fall back to now() if we never ran * before and thus have no cached time. */ |