diff options
Diffstat (limited to 'hwclock')
| -rw-r--r-- | hwclock/hwclock.8 | 4 | ||||
| -rw-r--r-- | hwclock/hwclock.c | 10 |
2 files changed, 12 insertions, 2 deletions
diff --git a/hwclock/hwclock.8 b/hwclock/hwclock.8 index 7f0c53d9..ba9b0682 100644 --- a/hwclock/hwclock.8 +++ b/hwclock/hwclock.8 @@ -599,8 +599,6 @@ are supported by the hardware. .SH FILES .I /etc/adjtime .I /usr/share/zoneinfo/ -.RI ( /usr/lib/zoneinfo -on old systems) .I /dev/rtc .I /dev/rtc0 .I /dev/port @@ -614,6 +612,8 @@ on old systems) .BR settimeofday (2), .BR crontab (1), .BR tzset (3) +.BR /etc/init.d/hwclock.sh, +.BR /usr/share/doc/util-linux/README.Debian.hwclock .SH AUTHORS Written by Bryan Henderson, September 1996 (bryanh@giraffe-data.com), diff --git a/hwclock/hwclock.c b/hwclock/hwclock.c index 571d63fb..f691dfe5 100644 --- a/hwclock/hwclock.c +++ b/hwclock/hwclock.c @@ -1107,8 +1107,18 @@ determine_clock_access_method(const bool user_requests_ISA) { if (!ur) ur = probe_for_kd_clock(); + /* + * This final clause is a really bad idea on x86/AT PCs. You run the + * risk of a race condition with another copy of hwclock + * that already has /dev/rtc open. The fallback case on + * x86 is to then raise I/O priviledge level and access + * the RTC CMOS directly using I/O instructions. Simultaneous + * access like that can really hose the RTC. + */ +#if !defined(__i386__) if (!ur && !user_requests_ISA) ur = probe_for_cmos_clock(); +#endif if (debug) { if (ur) |