Bug 17305

Created attachment 7756 [details]
program to reproduce the problem

When using gdb 7.8 (or compiled from git), if a process does a pthread_join, gdb and the process hang and gdb stops responding to any input (Ctrl-C, Ctrl-\, Ctrl-z, etc). The only way to get out is to kill the process with SIGKILL, at which point gdb begins responding again. This did not happen with gdb 7.7.1.

$ gcc -Wall -o test -g test.c -pthread
$ gdb test
Exception caught while booting Guile.
Error in function "open-file":
No such file or directory: "/usr/share/gdb/guile/gdb/boot.scm"

warning: Could not complete Guile gdb module initialization from:
/usr/share/gdb/guile/gdb/boot.scm.
Limited Guile support is available.
Suggest passing --data-directory=/path/to/gdb/data-directory.

GNU gdb (GDB) 7.8.50.20140824-cvs
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Reading symbols from /tmp/test...done.
(gdb) r
Starting program: /tmp/test 
Got object file from memory but can't read symbols: File truncated.
warning: Could not load shared library symbols for linux-vdso.so.1.
Do you need "set solib-search-path" or "set sysroot"?
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/usr/lib/libthread_db.so.1".
[New Thread 0x7ffff780f700 (LWP 1277)]
test
test
test
test
test
test
test
test
test
test

At this point the process has hung (which it doesn't when not connected to gdb) and gdb doesn't respond to any keyboard input.

$ ps aux | grep test
ross      1268  0.0  0.3 108580 26096 pts/0    Sl   22:45   0:00 gdb/gdb /tmp/test
ross      1273  0.0  0.0  14588   740 pts/0    tl+  22:45   0:00 /tmp/test

For what it's worth, I'm running Arch Linux with Linux 3.16.1. Thanks!