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* [Bug libc/11161] New: process with closed fd 2 sees no problem on stdout @ 2010-01-12 19:45 kogorman at calpoly dot edu 2010-01-12 19:46 ` [Bug libc/11161] " kogorman at calpoly dot edu ` (2 more replies) 0 siblings, 3 replies; 5+ messages in thread From: kogorman at calpoly dot edu @ 2010-01-12 19:45 UTC (permalink / raw) To: glibc-bugs When a process is started with file descriptor 2 closed (such as some daemon processes, or for headless operation), or if fd 2 becomes closed without explicitly closing stdout, functions on filestream stdout do not report errors. I will attach a C program that illustrates this situation. Run it from bash as "fsbad >&-" to start with a closed STDOUT_FILENO. I know that processes which expect fd2 to be closed should not be writing to stdout, but it seems odd for the error not to be reported. What is even more odd is that the first attempt to use stdout changes 'errno' to EBADF, but otherwise gives a normal return. This was a problem for me because I am teaching systems programming, and I tell my students to get in the habit of checking all calls for errors, and they hit on this as a technique to test their code, and thoght they had done something wrong. -- Summary: process with closed fd 2 sees no problem on stdout Product: glibc Version: 2.8 Status: NEW Severity: normal Priority: P2 Component: libc AssignedTo: drepper at redhat dot com ReportedBy: kogorman at calpoly dot edu CC: glibc-bugs at sources dot redhat dot com,kogorman at calpoly dot edu http://sourceware.org/bugzilla/show_bug.cgi?id=11161 ------- You are receiving this mail because: ------- You are on the CC list for the bug, or are watching someone who is. ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug libc/11161] process with closed fd 2 sees no problem on stdout 2010-01-12 19:45 [Bug libc/11161] New: process with closed fd 2 sees no problem on stdout kogorman at calpoly dot edu @ 2010-01-12 19:46 ` kogorman at calpoly dot edu 2010-01-12 19:52 ` kogorman at calpoly dot edu 2010-01-15 8:00 ` drepper at redhat dot com 2 siblings, 0 replies; 5+ messages in thread From: kogorman at calpoly dot edu @ 2010-01-12 19:46 UTC (permalink / raw) To: glibc-bugs ------- Additional Comments From kogorman at calpoly dot edu 2010-01-12 19:46 ------- Created an attachment (id=4508) --> (http://sourceware.org/bugzilla/attachment.cgi?id=4508&action=view) C program to Illustrate the anomaly if started with file descriptor 2 closed -- http://sourceware.org/bugzilla/show_bug.cgi?id=11161 ------- You are receiving this mail because: ------- You are on the CC list for the bug, or are watching someone who is. ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug libc/11161] process with closed fd 2 sees no problem on stdout 2010-01-12 19:45 [Bug libc/11161] New: process with closed fd 2 sees no problem on stdout kogorman at calpoly dot edu 2010-01-12 19:46 ` [Bug libc/11161] " kogorman at calpoly dot edu @ 2010-01-12 19:52 ` kogorman at calpoly dot edu 2010-01-15 8:00 ` drepper at redhat dot com 2 siblings, 0 replies; 5+ messages in thread From: kogorman at calpoly dot edu @ 2010-01-12 19:52 UTC (permalink / raw) To: glibc-bugs ------- Additional Comments From kogorman at calpoly dot edu 2010-01-12 19:52 ------- Oops, that should be "fd 1". I hate typos in the title. -- http://sourceware.org/bugzilla/show_bug.cgi?id=11161 ------- You are receiving this mail because: ------- You are on the CC list for the bug, or are watching someone who is. ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug libc/11161] process with closed fd 2 sees no problem on stdout 2010-01-12 19:45 [Bug libc/11161] New: process with closed fd 2 sees no problem on stdout kogorman at calpoly dot edu 2010-01-12 19:46 ` [Bug libc/11161] " kogorman at calpoly dot edu 2010-01-12 19:52 ` kogorman at calpoly dot edu @ 2010-01-15 8:00 ` drepper at redhat dot com 2 siblings, 0 replies; 5+ messages in thread From: drepper at redhat dot com @ 2010-01-15 8:00 UTC (permalink / raw) To: glibc-bugs ------- Additional Comments From drepper at redhat dot com 2010-01-15 07:59 ------- The behavior is as expected. There are situations where this is exactly what you want. We are even reassigning the unopened descriptors to /dev/null in security critical apps. -- What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |RESOLVED Resolution| |INVALID http://sourceware.org/bugzilla/show_bug.cgi?id=11161 ------- You are receiving this mail because: ------- You are on the CC list for the bug, or are watching someone who is. ^ permalink raw reply [flat|nested] 5+ messages in thread
[parent not found: <bug-11161-131@http.sourceware.org/bugzilla/>]
* [Bug libc/11161] process with closed fd 2 sees no problem on stdout [not found] <bug-11161-131@http.sourceware.org/bugzilla/> @ 2014-06-30 20:23 ` fweimer at redhat dot com 0 siblings, 0 replies; 5+ messages in thread From: fweimer at redhat dot com @ 2014-06-30 20:23 UTC (permalink / raw) To: glibc-bugs https://sourceware.org/bugzilla/show_bug.cgi?id=11161 Florian Weimer <fweimer at redhat dot com> changed: What |Removed |Added ---------------------------------------------------------------------------- Flags| |security- -- You are receiving this mail because: You are on the CC list for the bug. ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2014-06-30 20:23 UTC | newest] Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2010-01-12 19:45 [Bug libc/11161] New: process with closed fd 2 sees no problem on stdout kogorman at calpoly dot edu 2010-01-12 19:46 ` [Bug libc/11161] " kogorman at calpoly dot edu 2010-01-12 19:52 ` kogorman at calpoly dot edu 2010-01-15 8:00 ` drepper at redhat dot com [not found] <bug-11161-131@http.sourceware.org/bugzilla/> 2014-06-30 20:23 ` fweimer at redhat dot com
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