Red Hat Bugzilla – Bug 122730
Problem with reentrant getservbyname_r() calls in threaded programs
Last modified: 2007-11-30 17:07:01 EST
Description of problem: Threaded program crashes with multiple concurrent getservbyname_r() calls on NIS boxes. Version-Release number of selected component (if applicable): glibc-2.3.2-95.6 How reproducible: Easy Steps to Reproduce: 1. Build test program (will attach shortly) 2. Execute test program Actual results: Program crashes Expected results: Threads each call getservbyname_r() consecutively for a number of times, then after 30 seconds the program exits. Additional info: I could only reproduce this on RHEL3 when bound to a NIS domain, RHEL2.1 and FC2 don't show this behaviour.
Created attachment 100080 [details] Test program Test program, compile with: gcc -o main main.c -lpthread run with: ./main The program opens a number of threads which each consecutively call getservbyname_r() for a nonexisting service "gurus" (just an example) a number of times (200 in the attached test program).
Are you able to reproduce this with glibc-2.3.2-95.20 (U2 glibc)? There have been a bunch of fixes in exactly this part of the NIS client code.
Yes, I got the SIGSEGV with 2.3.2-95.20 as well.
http://sources.redhat.com/ml/libc-hacker/2004-05/msg00038.html Wonder why you haven't seen it on FC2, wasn't it UP and a bit of sheer luck?
Created attachment 102278 [details] Different test program which shows the problem on FC2 as well Another test program which shows the problem on FC2 as well, courtesy of Fabrizio Muscarella, refined by me. Simply untar and make. Builds nis_tst_getservbyname_r and nis_tst_getaddrinfo which use getservbyname_r() or getaddrinfo() respectively.
Can you reproduce it with glibc-2.3.3-31 or later though (rawhide/FC3t1)?
Ping!? I cannot reproduce any problem with glibc-2.3.3-45.i686. The program prints Oops... (Servname not supported for ai_socktype)
Oops indeed, will check when I have access to an FC3 box later in the day.
Hi, the output 'Oops...' is printed only by the second test program if you compile it without USE_GETSERVBYNAME_R (bacause i forgot to check the return value of getservbyname_r , mmmmm ;-( ). In this case will be interesting to known if getservbyname_r is working too.
I see no failures with a current glibc version in neither versions of the program in the second patch. I mark the bug as fixed. If you still see failures, please reopen with appropriate instructions to reproduce.