Date: Thu, 25 Mar 2004 22:57:02 -0800 (PST) From: Gregory Harris <gharris@ipsentinel.com> To: freebsd-gnats-submit@FreeBSD.org Subject: kern/64739: data being lost through FIFOs Message-ID: <200403260657.i2Q6v2o0056434@www.freebsd.org> Resent-Message-ID: <200403260700.i2Q70WRh063267@freefall.freebsd.org>
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>Number: 64739
>Category: kern
>Synopsis: data being lost through FIFOs
>Confidential: no
>Severity: serious
>Priority: medium
>Responsible: freebsd-bugs
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: sw-bug
>Submitter-Id: current-users
>Arrival-Date: Thu Mar 25 23:00:31 PST 2004
>Closed-Date:
>Last-Modified:
>Originator: Gregory Harris
>Release: 5.1
>Organization:
>Environment:
FreeBSD enos.ipsentinel.com 5.1-SECURITY FreeBSD 5.1-SECURITY #0: Thu Feb 5 08:13:19 GMT 2004 root@builder.daemonology.net:/usr/obj/usr/src/sys/GENERIC i386
>Description:
Data seems to be either be getting lost in FIFOs, or the FIFOs are not being properly flushed when the write end is being closed. Attached is a tarball containing a simple client and server program. The program operates normally on FreeBSD 4.8, Linux, and Solaris, but fails to operate properly under FreeBSD 5.1, and FreeBSD 5.2.1. Sorry for submitting a sample program, but it was the only way I can replicate the error.
>How-To-Repeat:
Attached is some sample code to illustrate the problem. Run the server program first via ./server, and then run the client program via ./client. FIFO data will then be sent from the server to the client saying "test x" where x is a number from 0 to 9. There is a 1 second pause between each message. Before the counter reaches 9, hit ctrl-c to send SIGINT to the client. The client program will then send a message over a FIFO to the server telling it to stop. The server will then send a SIGUSR2 signal to its child process managing the test data, which then SHOULD send "___end" back to the client over the FIFO to cause the client to shutdown and go back to a shell prompt. However the "___end" message is not received so the client just hangs waiting for the final message.
>Fix:
>Release-Note:
>Audit-Trail:
>Unformatted:
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