[patch] segfault in ProcessPOSIX on destroy the object

Hi everyone,

here is a patch, which fixes a segmentation fault crash in lldb in the ProcessPOSIX class when the object gets destroyed. I can reproduce this problem on the FreeBSD platform and it should be reproducable for the other platforms also.

The steps to reproduce (log):

freebsd1# ./lldb /bin/ls
Current executable set to ‘/bin/ls’ (x86_64).
(lldb) platform select remote-freebsd
Host: FreeBSD 9.0-RELEASE FreeBSD 9.0-RELEASE #0: Tue Jan 3 07:46:30 UTC 2012 root@farrell.cse.buffalo.edu:/usr/obj/usr/src/sys/GENERIC
(lldb) process connect localhost
error: remote connections are not supported
(lldb) exit
Segmentation fault (core dumped)

Stack trace:

Program received signal SIGSEGV, Segmentation fault.
ProcessMonitor::GetPID (this=0x0) at ProcessMonitor.h:67
67 GetPID() const { return m_pid; }
(gdb) bt
#0 ProcessMonitor::GetPID (this=0x0) at ProcessMonitor.h:67
#1 0x00000008023b6890 in ProcessPOSIX::DoDestroy (this=0x805f4b800) at /usr/home/projects/llvm-lldb/tools/lldb/source/Plugins/Process/POSIX/ProcessPOSIX.cpp:295
#2 0x0000000801703ff6 in lldb_private::Process::Destroy (this=0x805f4b800) at /usr/home/projects/llvm-lldb/tools/lldb/source/Target/Process.cpp:2887
#3 0x0000000801729be4 in lldb_private::Target::DeleteCurrentProcess (this=0x808b8d600) at /usr/home/projects/llvm-lldb/tools/lldb/source/Target/Target.cpp:132
#4 0x00000008012fdf03 in CommandObjectProcessConnect::Execute (this=0x805c2fc00, command=@0x7fffffffbf00, result=@0x805d48140)
at /usr/home/projects/llvm-lldb/tools/lldb/source/Commands/CommandObjectProcess.cpp:883
#5 0x00000008014bdf40 in lldb_private::CommandObject::ExecuteWithOptions (this=0x805c2fc00, args=@0x7fffffffbf00, result=@0x805d48140)
at /usr/home/projects/llvm-lldb/tools/lldb/source/Interpreter/CommandObject.cpp:281
#6 0x00000008014b2283 in lldb_private::CommandInterpreter::HandleCommand (this=0x805ca4200, command_line=0x80a41f198 “process connect connect://localhost”, add_to_history=true,
result=@0x805d48140, override_context=0x0, repeat_on_empty_command=true, no_context_switching=false) at /usr/home/projects/llvm-lldb/tools/lldb/source/Interpreter/CommandInterpreter.cpp:1540
#7 0x000000080124a7b5 in lldb::SBCommandInterpreter::HandleCommand (this=0x7fffffffc2e0, command_line=0x80a41f198 “process connect connect://localhost”, result=@0x7fffffffc2e8,
add_to_history=true) at /usr/home/projects/llvm-lldb/tools/lldb/source/API/SBCommandInterpreter.cpp:97
#8 0x000000000040b666 in Driver::HandleIOEvent (this=0x7fffffffd708, event=@0x7fffffffc550) at /usr/home/projects/llvm-lldb/tools/lldb/tools/driver/Driver.cpp:980
#9 0x000000000040cc3e in Driver::MainLoop (this=0x7fffffffd708) at /usr/home/projects/llvm-lldb/tools/lldb/tools/driver/Driver.cpp:1406
#10 0x000000000040d28b in main (argc=2, argv=0x7fffffffd878, envp=0x7fffffffd890) at /usr/home/projects/llvm-lldb/tools/lldb/tools/driver/Driver.cpp:1540

Would somebody review and apply this patch if it looks ok?
Thanks.
Viktor.

lldb-processposix-crash.patch (559 Bytes)

Looks good.

% svn commit
Sending source/Plugins/Process/POSIX/ProcessPOSIX.cpp
Transmitting file data .
Committed revision 153769.