Buffering syslogd output to pipe

[slw_zxy.spb.ru]

Summary

syslogd currently does O_NONBLOCK output to pipe. As a result any micro-burst can cause an overflow of the pipe buffer (64KB) and kill the script.
Patch allows to buffer (-g SIZE total bytes) for up to 10 seconds per script before killing script.

[slw_zxy.spb.ru]

auto-tuning by hw.usermem and use __XSTRING

[markj]

I plan to commit a number of syslogd patches this week (some refactoring from @jfree in preparation for running syslogd under Capsicum, see the patch stack starting with D41357), so please hold off on committing this for a bit.

/usr/src/usr.sbin/syslogd/syslogd.c

1995

cnt is size_t, an unsigned type, so this check is always false. It should be ssize_t.

[slw_zxy.spb.ru]

cnt is size_t, an unsigned type, so this check is always false. It should be ssize_t.

[slw_zxy.spb.ru]

In D41448#943957, @markj wrote:

I plan to commit a number of syslogd patches this week (some refactoring from @jfree in preparation for running syslogd under Capsicum, see the patch stack starting with D41357), so please hold off on committing this for a bit.

I can tailor a patch to fit your changes so you can commit it too.

[slw_zxy.spb.ru]

Update to latest syslogd changes