From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.3 required=5.0 tests=BAYES_00,INVALID_MSGID autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,93db2bcd4637d4fc X-Google-Attributes: gid103376,public From: Markus Kuhn Subject: Re: Runtime Error with gnat 3.10p Date: 1998/05/26 Message-ID: <356AF4B7.5EBF8617@cl.cam.ac.uk>#1/1 X-Deja-AN: 356680545 Content-Transfer-Encoding: 7bit References: <6kel87$ic7$1@polo.advicom.net> Content-Type: text/plain; charset=us-ascii Organization: Cambridge University, Computer Laboratory Mime-Version: 1.0 Newsgroups: comp.lang.ada Date: 1998-05-26T00:00:00+00:00 List-Id: David C. Hoos, Sr. wrote: > >does anyone have an idea what the following little message is about : > >Failed Runtime Assertion : GNULLI failure---Set_Priority > > > >Note that this showed up after executing a compiled Ada program > >containing several tasks (instantiated task types) > >This is on RedHat-Linux. > One of the runtimes requires root privileges to do tasking while the > other does not (I forget which is which). Under Linux, the RM Annex D real-time task priorities can only be fully implemented on top of POSIX.1c threads if the process is running with root privileges. Otherwise, a malicious non-root process could lock-up the entire system by requesting FIFO_Queuing and going into an endless loop (in other words, you do not want full Annex D compliance for normal untrusted users on a multi-user system). Make sure you use the rts-fsu and not the rts-native run-time library system, i.e. set the links in the gcc-lib/i386-linux/2.7.2.1/ subdirectory accordingly as described in the gnat install documentation, unless you work on a special time-critical application. See also "man 2 sched_setscheduler" for the underlying C system call and its restrictions. Markus (who wrote sched_setscheduler() back in the Linux 1.3 kernel :) ftp://ftp.informatik.uni-erlangen.de/local/cip/mskuhn/misc/linux-posix.1b -- Markus G. Kuhn, Security Group, Computer Lab, Cambridge University, UK email: mkuhn at acm.org, home page: