bin/149403: truss hangs when user input is requested

[Marcin Wisnicki]

>Number:         149403
>Category:       bin
>Synopsis:       truss hangs when user input is requested
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Sat Aug 07 15:10:04 UTC 2010
>Closed-Date:
>Last-Modified:
>Originator:     Marcin Wisnicki
>Release:        8.1-PRERELEASE
>Organization:
>Environment:
FreeBSD ghost.pnet.one.pl 8.1-PRERELEASE FreeBSD 8.1-PRERELEASE #4: Wed Jul 14 21:47:49 CEST 2010     root at ghost.pnet.one.pl:/home/obj/usr/src/sys/SERWER_DDB  i386
>Description:
When monitored program requests user input, truss hangs. Only way to recover is to kill it with SIGKILL. Problem occurs regardless of '-S', '-o' or '-c' flags.
>How-To-Repeat:
# this one is ok
% truss read abc < /dev/null
..
__getcwd("/home/marcin",256)                     = 0 (0x0)
read(10,"#!/bin/sh\n# $FreeBSD: src/usr.b"...,1023) = 161 (0xa1)
read(0,0xbfbfe84b,1)                             = 0 (0x0)
read(10,0x8065e20,1023)                          = 0 (0x0)
process exit, rval = 1

# this one is not
% truss read abc
__getcwd("/home/marcin",256)                     = 0 (0x0)
read(10,"#!/bin/sh\n# $FreeBSD: src/usr.b"...,1023) = 161 (0xa1)
SIGNAL 21 (SIGTTIN)
# ^T
load: 0.18  cmd: truss 11847 [wait] 1.40r 0.06u 0.04s 0% 1176k

>Fix:


>Release-Note:
>Audit-Trail:
>Unformatted: