#2328 closed defect (fixed)
ubuntu 16.04 python3 shadow server segfault on exit
| Reported by: | Antoine Martin | Owned by: | Antoine Martin |
|---|---|---|---|
| Priority: | minor | Milestone: | 3.0 |
| Component: | server | Version: | 2.5.x |
| Keywords: | Cc: |
Description
Discovered whilst testing for #2296.
Only seems to affect Ubuntu 16.04: also tested on Fedora and Ubuntu 18.04.
The server segfault can be triggered from both xpra stop and the exit-with-client switch.
Change History (5)
comment:1 Changed 2 years ago by
| Status: | new → assigned |
|---|
comment:2 Changed 2 years ago by
| Resolution: | → fixed |
|---|---|
| Status: | assigned → closed |
The crash is triggered by close_gtk_display.
Skipping this cleanup step with XPRA_CLOSE_GTK_DISPLAY=0 fixes the problem.
r22928 re-orders the cleanup code (related, but not a fix for this crash).
r22929 + r22930 just skips closing the display for python3 shadow servers on Ubuntu 16.04 only!
(note: this cleanup code runs more than once, but that's not the cause of the crash)
comment:4 Changed 15 months ago by
The default has been changed due to more crashes in Ubuntu 20.04: ticket:2761#comment:3.
comment:5 Changed 6 months ago by
this ticket has been moved to: https://github.com/Xpra-org/xpra/issues/2328
copyleft 2010 - 2021
One does not need to ever have connected a client to trigger the segfault, which should rule out x11 shared memory race conditions during cleanup.
Still occurs when running with minimal features enabled:
(though I did find a bug along the way: r22927)
Backtrace from gdb:
#0 0x00007ffff0b82134 in gdk_error_trap_push () at /build/gtk+3.0-2Ut_nl/gtk+3.0-3.18.9/./gdk/gdkdisplay.c:2185 #1 0x00007fffec53de40 in ffi_call_unix64 () from /usr/lib/x86_64-linux-gnu/libffi.so.6 #2 0x00007fffec53d8ab in ffi_call () from /usr/lib/x86_64-linux-gnu/libffi.so.6 #3 0x00007fffe9b2d8fc in ?? () from /usr/lib/python3/dist-packages/gi/_gi.cpython-35m-x86_64-linux-gnu.so #4 0x00007fffe9b2f3e8 in ?? () from /usr/lib/python3/dist-packages/gi/_gi.cpython-35m-x86_64-linux-gnu.so #5 0x00000000005c20e7 in PyObject_Call () at ../Objects/abstract.c:2165 #6 0x000000000053b656 in do_call (nk=<optimized out>, na=<optimized out>, pp_stack=0x7fffffffb550, func=<optimized out>) at ../Python/ceval.c:4936 #7 call_function (oparg=<optimized out>, pp_stack=0x7fffffffb550) at ../Python/ceval.c:4732 #8 PyEval_EvalFrameEx () at ../Python/ceval.c:3236 #9 0x000000000053b294 in fast_function (nk=<optimized out>, na=<optimized out>, n=<optimized out>, pp_stack=0x7fffffffb680, func=<optimized out>) at ../Python/ceval.c:4803 #10 call_function (oparg=<optimized out>, pp_stack=0x7fffffffb680) at ../Python/ceval.c:4730 #11 PyEval_EvalFrameEx () at ../Python/ceval.c:3236 #12 0x0000000000540b0b in _PyEval_EvalCodeWithName (qualname=0x0, name=0x0, closure=0x0, kwdefs=0x0, defcount=0, defs=0x0, kwcount=0, kws=<optimized out>, argcount=<optimized out>, args=<optimized out>, locals=<optimized out>, globals=<optimized out>, _co=<code at remote 0x7fffe978a1e0>) at ../Python/ceval.c:4018 #13 PyEval_EvalCodeEx () at ../Python/ceval.c:4039 #14 0x00000000004ec2e3 in function_call.lto_priv () at ../Objects/funcobject.c:627 #15 0x00000000005c20e7 in PyObject_Call () at ../Objects/abstract.c:2165 #16 0x00000000004fbfce in method_call.lto_priv () at ../Objects/classobject.c:330 #17 0x00000000005c20e7 in PyObject_Call () at ../Objects/abstract.c:2165 #18 0x00000000005c22d8 in PyObject_CallFunctionObjArgs () at ../Objects/abstract.c:2445 ---Type <return> to continue, or q <return> to quit--- #19 0x00000000005387c5 in PyEval_EvalFrameEx () at ../Python/ceval.c:3107 #20 0x000000000053b294 in fast_function (nk=<optimized out>, na=<optimized out>, n=<optimized out>, pp_stack=0x7fffffffbbe0, func=<optimized out>) at ../Python/ceval.c:4803 #21 call_function (oparg=<optimized out>, pp_stack=0x7fffffffbbe0) at ../Python/ceval.c:4730 #22 PyEval_EvalFrameEx () at ../Python/ceval.c:3236 #23 0x000000000053b294 in fast_function (nk=<optimized out>, na=<optimized out>, n=<optimized out>, pp_stack=0x7fffffffbd10, func=<optimized out>) at ../Python/ceval.c:4803 #24 call_function (oparg=<optimized out>, pp_stack=0x7fffffffbd10) at ../Python/ceval.c:4730 #25 PyEval_EvalFrameEx () at ../Python/ceval.c:3236 #26 0x000000000053b294 in fast_function (nk=<optimized out>, na=<optimized out>, n=<optimized out>, pp_stack=0x7fffffffbe40, func=<optimized out>) at ../Python/ceval.c:4803 #27 call_function (oparg=<optimized out>, pp_stack=0x7fffffffbe40) at ../Python/ceval.c:4730 #28 PyEval_EvalFrameEx () at ../Python/ceval.c:3236 #29 0x000000000053b294 in fast_function (nk=<optimized out>, na=<optimized out>, n=<optimized out>, pp_stack=0x7fffffffbf70, func=<optimized out>) at ../Python/ceval.c:4803 #30 call_function (oparg=<optimized out>, pp_stack=0x7fffffffbf70) at ../Python/ceval.c:4730 #31 PyEval_EvalFrameEx () at ../Python/ceval.c:3236 #32 0x00000000005401ef in _PyEval_EvalCodeWithName () at ../Python/ceval.c:4018 #33 0x000000000053b83f in fast_function (nk=<optimized out>, na=<optimized out>, n=<optimized out>, pp_stack=0x7fffffffc180, func=<optimized out>) at ../Python/ceval.c:4813 #34 call_function (oparg=<optimized out>, pp_stack=0x7fffffffc180) at ../Python/ceval.c:4730 #35 PyEval_EvalFrameEx () at ../Python/ceval.c:3236 #36 0x000000000053b294 in fast_function (nk=<optimized out>, na=<optimized out>, n=<optimized out>, pp_stack=0x7fffffffc2b0, func=<optimized out>) at ../Python/ceval.c:4803 #37 call_function (oparg=<optimized out>, pp_stack=0x7fffffffc2b0) at ../Python/ceval.c:4730 ---Type <return> to continue, or q <return> to quit--- #38 PyEval_EvalFrameEx () at ../Python/ceval.c:3236 #39 0x000000000053b294 in fast_function (nk=<optimized out>, na=<optimized out>, n=<optimized out>, pp_stack=0x7fffffffc3e0, func=<optimized out>) at ../Python/ceval.c:4803 #40 call_function (oparg=<optimized out>, pp_stack=0x7fffffffc3e0) at ../Python/ceval.c:4730 #41 PyEval_EvalFrameEx () at ../Python/ceval.c:3236 #42 0x0000000000540b0b in _PyEval_EvalCodeWithName (qualname=0x0, name=0x0, closure=0x0, kwdefs=0x0, defcount=0, defs=0x0, kwcount=0, kws=<optimized out>, argcount=<optimized out>, args=<optimized out>, locals=<optimized out>, globals=<optimized out>, _co=<code at remote 0x7fffe967cd20>) at ../Python/ceval.c:4018 #43 PyEval_EvalCodeEx () at ../Python/ceval.c:4039 #44 0x00000000004ec2e3 in function_call.lto_priv () at ../Objects/funcobject.c:627 #45 0x00000000005c20e7 in PyObject_Call () at ../Objects/abstract.c:2165 #46 0x00000000004fbfce in method_call.lto_priv () at ../Objects/classobject.c:330 #47 0x00000000005c20e7 in PyObject_Call () at ../Objects/abstract.c:2165 #48 0x0000000000534870 in PyEval_CallObjectWithKeywords () at ../Python/ceval.c:4580 #49 0x00007fffe9b2b4cc in ?? () from /usr/lib/python3/dist-packages/gi/_gi.cpython-35m-x86_64-linux-gnu.so #50 0x00007fffec53dc2f in ffi_closure_unix64_inner () from /usr/lib/x86_64-linux-gnu/libffi.so.6 #51 0x00007fffec53dfa8 in ffi_closure_unix64 () from /usr/lib/x86_64-linux-gnu/libffi.so.6 #52 0x00007fffefa2d04a in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0 #53 0x00007fffefa2d3f0 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0 #54 0x00007fffefa2d712 in g_main_loop_run () from /lib/x86_64-linux-gnu/libglib-2.0.so.0 #55 0x00007fffe8f5b395 in gtk_main () at /build/gtk+3.0-2Ut_nl/gtk+3.0-3.18.9/./gtk/gtkmain.c:1241 #56 0x00007fffec53de40 in ffi_call_unix64 () from /usr/lib/x86_64-linux-gnu/libffi.so.6 #57 0x00007fffec53d8ab in ffi_call () from /usr/lib/x86_64-linux-gnu/libffi.so.6 #58 0x00007fffe9b2d8fc in ?? () from /usr/lib/python3/dist-packages/gi/_gi.cpython-35m-x86_64-linux-gnu.so ---Type <return> to continue, or q <return> to quit--- #59 0x00007fffe9b2f3e8 in ?? () from /usr/lib/python3/dist-packages/gi/_gi.cpython-35m-x86_64-linux-gnu.so #60 0x00000000005c20e7 in PyObject_Call () at ../Objects/abstract.c:2165 #61 0x000000000053b656 in do_call (nk=<optimized out>, na=<optimized out>, pp_stack=0x7fffffffcd60, func=<optimized out>) at ../Python/ceval.c:4936 #62 call_function (oparg=<optimized out>, pp_stack=0x7fffffffcd60) at ../Python/ceval.c:4732 #63 PyEval_EvalFrameEx () at ../Python/ceval.c:3236 #64 0x000000000053b294 in fast_function (nk=<optimized out>, na=<optimized out>, n=<optimized out>, pp_stack=0x7fffffffce90, func=<optimized out>) at ../Python/ceval.c:4803 #65 call_function (oparg=<optimized out>, pp_stack=0x7fffffffce90) at ../Python/ceval.c:4730 #66 PyEval_EvalFrameEx () at ../Python/ceval.c:3236 #67 0x00000000005401ef in _PyEval_EvalCodeWithName () at ../Python/ceval.c:4018 #68 0x000000000053bc93 in fast_function (nk=<optimized out>, na=<optimized out>, n=<optimized out>, pp_stack=0x7fffffffd0a0, func=<optimized out>) at ../Python/ceval.c:4813 #69 call_function (oparg=<optimized out>, pp_stack=0x7fffffffd0a0) at ../Python/ceval.c:4730 #70 PyEval_EvalFrameEx () at ../Python/ceval.c:3236 #71 0x00000000005401ef in _PyEval_EvalCodeWithName () at ../Python/ceval.c:4018 #72 0x000000000053b83f in fast_function (nk=<optimized out>, na=<optimized out>, n=<optimized out>, pp_stack=0x7fffffffd2b0, func=<optimized out>) at ../Python/ceval.c:4813 #73 call_function (oparg=<optimized out>, pp_stack=0x7fffffffd2b0) at ../Python/ceval.c:4730 #74 PyEval_EvalFrameEx () at ../Python/ceval.c:3236 #75 0x000000000053fc97 in _PyEval_EvalCodeWithName () at ../Python/ceval.c:4018 #76 0x000000000053b83f in fast_function (nk=<optimized out>, na=<optimized out>, n=<optimized out>, pp_stack=0x7fffffffd4c0, func=<optimized out>) at ../Python/ceval.c:4813 #77 call_function (oparg=<optimized out>, pp_stack=0x7fffffffd4c0) at ../Python/ceval.c:4730 #78 PyEval_EvalFrameEx () at ../Python/ceval.c:3236 ---Type <return> to continue, or q <return> to quit--- #79 0x00000000005401ef in _PyEval_EvalCodeWithName () at ../Python/ceval.c:4018 #80 0x000000000053bc93 in fast_function (nk=<optimized out>, na=<optimized out>, n=<optimized out>, pp_stack=0x7fffffffd6d0, func=<optimized out>) at ../Python/ceval.c:4813 #81 call_function (oparg=<optimized out>, pp_stack=0x7fffffffd6d0) at ../Python/ceval.c:4730 #82 PyEval_EvalFrameEx () at ../Python/ceval.c:3236 #83 0x000000000053b294 in fast_function (nk=<optimized out>, na=<optimized out>, n=<optimized out>, pp_stack=0x7fffffffd800, func=<optimized out>) at ../Python/ceval.c:4803 #84 call_function (oparg=<optimized out>, pp_stack=0x7fffffffd800) at ../Python/ceval.c:4730 #85 PyEval_EvalFrameEx () at ../Python/ceval.c:3236 #86 0x000000000053fc97 in _PyEval_EvalCodeWithName () at ../Python/ceval.c:4018 #87 0x00000000005409bf in PyEval_EvalCodeEx () at ../Python/ceval.c:4039 #88 PyEval_EvalCode (co=<optimized out>, globals=<optimized out>, locals=<optimized out>) at ../Python/ceval.c:777 #89 0x000000000060cb42 in run_mod () at ../Python/pythonrun.c:976 #90 0x000000000060efea in PyRun_FileExFlags () at ../Python/pythonrun.c:929 #91 0x000000000060f7dc in PyRun_SimpleFileExFlags () at ../Python/pythonrun.c:396 #92 0x0000000000640256 in run_file (p_cf=0x7fffffffda70, filename=0xa752e0 L"/usr/bin/xpra", fp=0xad5e80) at ../Modules/main.c:318 #93 Py_Main () at ../Modules/main.c:768 #94 0x00000000004d0001 in main () at ../Programs/python.c:65 #95 0x00007ffff7810830 in __libc_start_main (main=0x4cff20 <main>, argc=19, argv=0x7fffffffdc88, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fffffffdc78) at ../csu/libc-start.c:291 #96 0x00000000005d6999 in _start ()(gdb) py-bt Traceback (most recent call first): File "/usr/lib/python3/dist-packages/xpra/gtk_common/error.py", line 109, in Xenter gdk.error_trap_push() File "/usr/lib/python3/dist-packages/xpra/gtk_common/error.py", line 207, in __enter__ trap.Xenter() File "/usr/lib/python3/dist-packages/xpra/x11/x11_server_core.py", line 310, in do_cleanup with xswallow: File "/usr/lib/python3/dist-packages/xpra/server/server_core.py", line 433, in cleanup self.do_cleanup() File "/usr/lib/python3/dist-packages/xpra/server/shadow/gtk_shadow_server_base.py", line 54, in cleanup GTKServerBase.cleanup(self) #@UndefinedVariable File "/usr/lib/python3/dist-packages/xpra/x11/shadow_x11_server.py", line 143, in cleanup GTKShadowServerBase.cleanup(self) File "/usr/lib/python3/dist-packages/xpra/server/server_core.py", line 354, in clean_quit self.cleanup() File "/usr/lib/python3/dist-packages/xpra/server/server_base.py", line 842, in last_client_exited self.clean_quit(False) File "/usr/lib/python3/dist-packages/xpra/server/shadow/gtk_shadow_server_base.py", line 69, in last_client_exited GTKServerBase.last_client_exited(self) File "/usr/lib/python3/dist-packages/xpra/x11/shadow_x11_server.py", line 152, in last_client_exited GTKShadowServerBase.last_client_exited(self) File "/usr/lib/python3/dist-packages/xpra/server/gtk_server_base.py", line 94, in do_run gtk_main() File "/usr/lib/python3/dist-packages/xpra/server/server_core.py", line 409, in run ---Type <return> to continue, or q <return> to quit--- self.do_run() File "/usr/lib/python3/dist-packages/xpra/scripts/server.py", line 958, in do_run_server r = app.run() File "/usr/lib/python3/dist-packages/xpra/scripts/server.py", line 444, in run_server return do_run_server(error_cb, opts, mode, xpra_file, extra_args, desktop_display) File "/usr/lib/python3/dist-packages/xpra/scripts/main.py", line 432, in run_mode return run_server(error_cb, options, mode, script_file, args, current_display) File "/usr/lib/python3/dist-packages/xpra/scripts/main.py", line 97, in main return run_mode(script_file, err, options, args, mode, defaults) File "/usr/bin/xpra", line 26, in <module> sys.exit(main(sys.argv[0], sys.argv))