Date: Wed, 18 Sep 2002 19:23:31 -0700 (PDT) From: pqf <pqf@163.net> To: freebsd-gnats-submit@FreeBSD.org Subject: misc/42943: fd 0,1,2 should not be set to nonblock in _thread_fd_table_init() Message-ID: <200209190223.g8J2NVDO061737@www.freebsd.org>
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>Number: 42943 >Category: misc >Synopsis: fd 0,1,2 should not be set to nonblock in _thread_fd_table_init() >Confidential: no >Severity: non-critical >Priority: medium >Responsible: freebsd-bugs >State: open >Quarter: >Keywords: >Date-Required: >Class: change-request >Submitter-Id: current-users >Arrival-Date: Wed Sep 18 19:30:01 PDT 2002 >Closed-Date: >Last-Modified: >Originator: pqf >Release: FreeBSD bsd 4.6.2-RELEASE >Organization: www.tebie.com >Environment: FreeBSD bsd 4.6.2-RELEASE FreeBSD 4.6.2-RELEASE #0: Wed Aug 14 21:23:26 GMT 2002 murray@builder.freebsdmall.com:/usr/src/sys/compile/GENERIC i386 >Description: in uthread_fd.c line 141, it set fd 0, 1, 2 to nonblock mode, and so the fd 0, 1, 2 in kernel is nonblock mode, but the mode of them in uthread level MAY be blocking normally, it's ok to do so, but think about the following condition: parend process call dup2() to make fd 0 be a unix domain socket parent process fork() muti-thread(pthread) child process child process set fd 0 to nonblock in _thread_fd_table_init() fd 0 is shared between parent process and child process, so the parent process's fd 0 is now nonblock, but the parent process DO NOT know what happen because it DID NOT do anything to fd 0... >How-To-Repeat: >Fix: comment line 140 to line 143 in uthread_fd.c >Release-Note: >Audit-Trail: >Unformatted: To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-bugs" in the body of the message
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