4eec2deb06
On GNU/Linux, if the target reuses the TID of a thread that GDB still has in its list marked as THREAD_EXITED, GDB crashes, like: (gdb) continue Continuing. src/gdb/thread.c:789: internal-error: set_running: Assertion `tp->state != THREAD_EXITED' failed. A problem internal to GDB has been detected, further debugging may prove unreliable. Quit this debugging session? (y or n) FAIL: gdb.threads/tid-reuse.exp: continue to breakpoint: after_reuse_time (GDB internal error) Here: (top-gdb) bt #0 internal_error (file=0x953dd8 "src/gdb/thread.c", line=789, fmt=0x953da0 "%s: Assertion `%s' failed.") at src/gdb/common/errors.c:54 #1 0x0000000000638514 in set_running (ptid=..., running=1) at src/gdb/thread.c:789 #2 0x00000000004bda42 in linux_handle_extended_wait (lp=0x16f5760, status=0, stopping=0) at src/gdb/linux-nat.c:2114 #3 0x00000000004bfa24 in linux_nat_filter_event (lwpid=20570, status=198015) at src/gdb/linux-nat.c:3127 #4 0x00000000004c070e in linux_nat_wait_1 (ops=0xe193d0, ptid=..., ourstatus=0x7fffffffd2c0, target_options=1) at src/gdb/linux-nat.c:3478 #5 0x00000000004c1015 in linux_nat_wait (ops=0xe193d0, ptid=..., ourstatus=0x7fffffffd2c0, target_options=1) at src/gdb/linux-nat.c:3722 #6 0x00000000004c92d2 in thread_db_wait (ops=0xd80b60 <thread_db_ops>, ptid=..., ourstatus=0x7fffffffd2c0, options=1) at src/gdb/linux-thread-db.c:1525 #7 0x000000000066db43 in delegate_wait (self=0xd80b60 <thread_db_ops>, arg1=..., arg2=0x7fffffffd2c0, arg3=1) at src/gdb/target-delegates.c:116 #8 0x000000000067e54b in target_wait (ptid=..., status=0x7fffffffd2c0, options=1) at src/gdb/target.c:2206 #9 0x0000000000625111 in fetch_inferior_event (client_data=0x0) at src/gdb/infrun.c:3275 #10 0x0000000000648a3b in inferior_event_handler (event_type=INF_REG_EVENT, client_data=0x0) at src/gdb/inf-loop.c:56 #11 0x00000000004c2ecb in handle_target_event (error=0, client_data=0x0) at src/gdb/linux-nat.c:4655 I managed to come up with a test that reliably reproduces this. It spawns enough threads for the pid number space to wrap around, so could potentially take a while. On my box that's 4 seconds; on gcc110, a PPC box which has max_pid set to 65536, it's over 10 seconds. So I made the test compute how long that would take, and cap the time waited if it would be unreasonably long. Tested on x86_64 Fedora 20. gdb/ChangeLog: 2015-04-01 Pedro Alves <palves@redhat.com> * linux-thread-db.c (record_thread): Readd the thread to gdb's list if it was marked exited. gdb/testsuite/ChangeLog: 2015-04-01 Pedro Alves <palves@redhat.com> * gdb.threads/tid-reuse.c: New file. * gdb.threads/tid-reuse.exp: New file.
README for GNU development tools This directory contains various GNU compilers, assemblers, linkers, debuggers, etc., plus their support routines, definitions, and documentation. If you are receiving this as part of a GDB release, see the file gdb/README. If with a binutils release, see binutils/README; if with a libg++ release, see libg++/README, etc. That'll give you info about this package -- supported targets, how to use it, how to report bugs, etc. It is now possible to automatically configure and build a variety of tools with one command. To build all of the tools contained herein, run the ``configure'' script here, e.g.: ./configure make To install them (by default in /usr/local/bin, /usr/local/lib, etc), then do: make install (If the configure script can't determine your type of computer, give it the name as an argument, for instance ``./configure sun4''. You can use the script ``config.sub'' to test whether a name is recognized; if it is, config.sub translates it to a triplet specifying CPU, vendor, and OS.) If you have more than one compiler on your system, it is often best to explicitly set CC in the environment before running configure, and to also set CC when running make. For example (assuming sh/bash/ksh): CC=gcc ./configure make A similar example using csh: setenv CC gcc ./configure make Much of the code and documentation enclosed is copyright by the Free Software Foundation, Inc. See the file COPYING or COPYING.LIB in the various directories, for a description of the GNU General Public License terms under which you can copy the files. REPORTING BUGS: Again, see gdb/README, binutils/README, etc., for info on where and how to report problems.