Fix v0p7 extension missing. #4

pz9115 · 2024-03-18T07:37:00Z

Add missing extension with RVV 0.7.

Bug PR gdb/28313 describes attaching to a process when the executable has been deleted. The bug is for S390 and describes how a user sees a message 'PC not saved'. On x86-64 (GNU/Linux) I don't see a 'PC not saved' message, but instead I see this: (gdb) attach 901877 Attaching to process 901877 No executable file now. warning: Could not load vsyscall page because no executable was specified 0x00007fa9d9c121e7 in ?? () (gdb) bt #0 0x00007fa9d9c121e7 in ?? () #1 0x00007fa9d9c1211e in ?? () #2 0x0000000000000007 in ?? () #3 0x000000002dc8b18d in ?? () #4 0x0000000000000000 in ?? () (gdb) Notice that the addresses in the backtrace don't seem right, quickly heading to 0x7 and finally ending at 0x0. What's going on, in both the s390 case and the x86-64 case is that the architecture's prologue scanner is going wrong and causing the stack unwinding to fail. The prologue scanner goes wrong because GDB has no unwind information. And GDB has no unwind information because, of course, the executable has been deleted. Notice in the example session above we get this line in the output: No executable file now. which indicates that GDB failed to find an executable to debug. For GNU/Linux when GDB tries to find an executable for a given pid we end up calling linux_proc_pid_to_exec_file in gdb/nat/linux-procfs.c. Within this function we call `readlink` on /proc/PID/exe to find the path of the actual executable. If the `readlink` call fails then we already fallback on using /proc/PID/exe as the path to the executable to debug. However, when the executable has been deleted the `readlink` call doesn't fail, but the path that is returned points to a non-existent file. I propose that we add an `access` call to linux_proc_pid_to_exec_file to check that the target file exists and can be read. If the target can't be read then we should fall back to /proc/PID/exe (assuming that /proc/PID/exe can be read). Now on x86-64 the output looks like this: (gdb) attach 901877 Attaching to process 901877 Reading symbols from /proc/901877/exe... Reading symbols from /lib64/libc.so.6... (No debugging symbols found in /lib64/libc.so.6) Reading symbols from /lib64/ld-linux-x86-64.so.2... (No debugging symbols found in /lib64/ld-linux-x86-64.so.2) 0x00007fa9d9c121e7 in nanosleep () from /lib64/libc.so.6 (gdb) bt #0 0x00007fa9d9c121e7 in nanosleep () from /lib64/libc.so.6 #1 0x00007fa9d9c1211e in sleep () from /lib64/libc.so.6 #2 0x000000000040117e in spin_forever () at attach-test.c:17 #3 0x0000000000401198 in main () at attach-test.c:24 (gdb) which is much better. I've also tagged the bug PR gdb/29782 which concerns the test gdb.server/connect-with-no-symbol-file.exp. After making this change, when running gdb.server/connect-with-no-symbol-file.exp GDB would now pick up the /proc/PID/exe file as the executable in some cases. As GDB is not restarted for the multiple iterations of this test GDB (or rather BFD) would given a warning/error like: (gdb) PASS: gdb.server/connect-with-no-symbol-file.exp: sysroot=target:: action=permission: setup: disconnect set sysroot target: BFD: reopening /proc/3283001/exe: No such file or directory (gdb) FAIL: gdb.server/connect-with-no-symbol-file.exp: sysroot=target:: action=permission: setup: adjust sysroot What's happening is that an executable found for an earlier iteration of the test is still registered for the inferior when we are setting up for a second iteration of the test. When the sysroot changes, if there's an executable registered GDB tries to reopen it, but in this case the file has disappeared (the previous inferior has exited by this point). I did think about maybe, when the executable is /proc/PID/exe, we should auto-delete the file from the inferior. But in the end I thought this was a bad idea. Not only would this require a lot of special code in GDB just to support this edge case: we'd need to track if the exe file name came from /proc and should be auto-deleted, or we'd need target specific code to check if a path should be auto-deleted..... ... in addition, we'd still want to warn the user when we auto-deleted the file from the inferior, otherwise they might be surprised to find their inferior suddenly has no executable attached, so we wouldn't actually reduce the number of warnings the user sees. So in the end I figured that the best solution is to just update the test to avoid the warning. This is easily done by manually removing the executable from the inferior once each iteration of the test has completed. Now, in bug PR gdb/29782 GDB is clearly managing to pick up an executable from the NFS cache somehow. I guess what's happening is that when the original file is deleted /proc/PID/exe is actually pointing to a file in the NFS cache which is only deleted at some later point, and so when GDB starts up we do manage to associate a file with the inferior, this results in the same message being emitted from BFD as I was seeing. The fix included in this commit should also fix that bug. One final note: On x86-64 GNU/Linux, the gdb.server/connect-with-no-symbol-file.exp test will produce 2 core files. This is due to a bug in gdbserver that is nothing to do with this test. These core files are created before and after this commit. I am working on a fix for the gdbserver issue, but will post that separately. Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28313 Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=29782 Approved-By: Tom Tromey <[email protected]>

On arm-linux the linaro CI occasionally reports: ... (gdb) up 10 #4 0x0001b864 in pthread_join () (gdb) FAIL: gdb.threads/staticthreads.exp: up 10 ... while this is expected: ... (gdb) up 10 #3 0x00010568 in main (argc=1, argv=0xfffeede4) at staticthreads.c:76 76 pthread_join (thread, NULL); (gdb) PASS: gdb.threads/staticthreads.exp: up 10 ... Thiago investigated the problem, and using valgrind found an invalid read in arm_exidx_fill_cache. The problem happens as follows: - an objfile and corresponding per_bfd are allocated - some memory is allocated in arm_exidx_new_objfile using objfile->objfile_obstack, for the "exception table entry cache". - a symbol reread is triggered, and the objfile, including the objfile_obstack, is destroyed - a new objfile is allocated, using the same per_bfd - again arm_exidx_new_objfile is called, but since the same per_bfd is used, it doesn't allocate any new memory for the "exception table entry cache". - the "exception table entry cache" is accessed by arm_exidx_fill_cache, and we have a use-after-free. This is a regression since commit a2726d4 ("[ARM] Store exception handling information per-bfd instead of per-objfile"), which changed the "exception table entry cache" from per-objfile to per-bfd, but failed to update the obstack_alloc. Fix this by using objfile->per_bfd->storage_obstack instead of objfile->objfile_obstack. I couldn't reproduce the FAIL myself, but Thiago confirmed that the patch fixes it. Tested on arm-linux. Approved-By: Luis Machado <[email protected]> PR tdep/31254 Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31254

When running test-case gdb.dap/eof.exp, it occasionally coredumps. The thread triggering the coredump is: ... #0 0x0000ffff42bb2280 in __pthread_kill_implementation () from /lib64/libc.so.6 #1 0x0000ffff42b65800 [PAC] in raise () from /lib64/libc.so.6 #2 0x00000000007b03e8 [PAC] in handle_fatal_signal (sig=11) at gdb/event-top.c:926 #3 0x00000000007b0470 in handle_sigsegv (sig=11) at gdb/event-top.c:976 #4 <signal handler called> #5 0x0000000000606080 in cli_ui_out::do_message (this=0xffff2f7ed728, style=..., format=0xffff0c002af1 "%s", args=...) at gdb/cli-out.c:232 XUANTIE-RV#6 0x0000000000ce6358 in ui_out::call_do_message (this=0xffff2f7ed728, style=..., format=0xffff0c002af1 "%s") at gdb/ui-out.c:584 #7 0x0000000000ce6610 in ui_out::vmessage (this=0xffff2f7ed728, in_style=..., format=0x16f93ea "", args=...) at gdb/ui-out.c:621 #8 0x0000000000ce3a9c in ui_file::vprintf (this=0xfffffbea1b18, ...) at gdb/ui-file.c:74 #9 0x0000000000d2b148 in gdb_vprintf (stream=0xfffffbea1b18, format=0x16f93e8 "%s", args=...) at gdb/utils.c:1898 #10 0x0000000000d2b23c in gdb_printf (stream=0xfffffbea1b18, format=0x16f93e8 "%s") at gdb/utils.c:1913 #11 0x0000000000ab5208 in gdbpy_write (self=0x33fe35d0, args=0x342ec280, kw=0x345c08b0) at gdb/python/python.c:1464 #12 0x0000ffff434acedc in cfunction_call () from /lib64/libpython3.12.so.1.0 #13 0x0000ffff4347c500 [PAC] in _PyObject_MakeTpCall () from /lib64/libpython3.12.so.1.0 #14 0x0000ffff43488b64 [PAC] in _PyEval_EvalFrameDefault () from /lib64/libpython3.12.so.1.0 #15 0x0000ffff434d8cd0 [PAC] in method_vectorcall () from /lib64/libpython3.12.so.1.0 #16 0x0000ffff434b9824 [PAC] in PyObject_CallOneArg () from /lib64/libpython3.12.so.1.0 #17 0x0000ffff43557674 [PAC] in PyFile_WriteObject () from /lib64/libpython3.12.so.1.0 #18 0x0000ffff435577a0 [PAC] in PyFile_WriteString () from /lib64/libpython3.12.so.1.0 #19 0x0000ffff43465354 [PAC] in thread_excepthook () from /lib64/libpython3.12.so.1.0 #20 0x0000ffff434ac6e0 [PAC] in cfunction_vectorcall_O () from /lib64/libpython3.12.so.1.0 #21 0x0000ffff434a32d8 [PAC] in PyObject_Vectorcall () from /lib64/libpython3.12.so.1.0 #22 0x0000ffff43488b64 [PAC] in _PyEval_EvalFrameDefault () from /lib64/libpython3.12.so.1.0 #23 0x0000ffff434d8d88 [PAC] in method_vectorcall () from /lib64/libpython3.12.so.1.0 #24 0x0000ffff435e0ef4 [PAC] in thread_run () from /lib64/libpython3.12.so.1.0 #25 0x0000ffff43591ec0 [PAC] in pythread_wrapper () from /lib64/libpython3.12.so.1.0 #26 0x0000ffff42bb0584 [PAC] in start_thread () from /lib64/libc.so.6 #27 0x0000ffff42c1fd4c [PAC] in thread_start () from /lib64/libc.so.6 ... The direct cause for the coredump seems to be that cli_ui_out::do_message is trying to write to a stream variable which does not look sound: ... (gdb) p *stream $8 = {_vptr.ui_file = 0x0, m_applied_style = {m_foreground = {m_simple = true, { m_value = 0, {m_red = 0 '\000', m_green = 0 '\000', m_blue = 0 '\000'}}}, m_background = {m_simple = 32, {m_value = 65535, {m_red = 255 '\377', m_green = 255 '\377', m_blue = 0 '\000'}}}, m_intensity = (unknown: 0x438fe710), m_reverse = 255}} ... The string that is being printed is: ... (gdb) p str $9 = "Exception in thread " ... so AFAICT this is a DAP thread running into an exception and trying to print it. If we look at the state of gdb's main thread, we have: ... #0 0x0000ffff42bac914 in __futex_abstimed_wait_cancelable64 () from /lib64/libc.so.6 #1 0x0000ffff42bafb44 [PAC] in pthread_cond_timedwait@@GLIBC_2.17 () from /lib64/libc.so.6 #2 0x0000ffff43466e9c [PAC] in take_gil () from /lib64/libpython3.12.so.1.0 #3 0x0000ffff43484fe0 [PAC] in PyEval_RestoreThread () from /lib64/libpython3.12.so.1.0 #4 0x0000000000ab8698 [PAC] in gdbpy_allow_threads::~gdbpy_allow_threads ( this=0xfffffbea1cf8, __in_chrg=<optimized out>) at gdb/python/python-internal.h:769 #5 0x0000000000ab2fec in execute_gdb_command (self=0x33fe35d0, args=0x34297b60, kw=0x34553d20) at gdb/python/python.c:681 XUANTIE-RV#6 0x0000ffff434acedc in cfunction_call () from /lib64/libpython3.12.so.1.0 #7 0x0000ffff4347c500 [PAC] in _PyObject_MakeTpCall () from /lib64/libpython3.12.so.1.0 #8 0x0000ffff43488b64 [PAC] in _PyEval_EvalFrameDefault () from /lib64/libpython3.12.so.1.0 #9 0x0000ffff4353bce8 [PAC] in _PyObject_VectorcallTstate.lto_priv.3 () from /lib64/libpython3.12.so.1.0 #10 0x0000000000ab87fc [PAC] in gdbpy_event::operator() (this=0xffff14005900) at gdb/python/python.c:1061 #11 0x0000000000ab93e8 in std::__invoke_impl<void, gdbpy_event&> (__f=...) at /usr/include/c++/13/bits/invoke.h:61 #12 0x0000000000ab9204 in std::__invoke_r<void, gdbpy_event&> (__fn=...) at /usr/include/c++/13/bits/invoke.h:111 #13 0x0000000000ab8e90 in std::_Function_handler<..>::_M_invoke(...) (...) at /usr/include/c++/13/bits/std_function.h:290 #14 0x000000000062e0d0 in std::function<void ()>::operator()() const ( this=0xffff14005830) at /usr/include/c++/13/bits/std_function.h:591 #15 0x0000000000b67f14 in run_events (error=0, client_data=0x0) at gdb/run-on-main-thread.c:76 #16 0x000000000157e290 in handle_file_event (file_ptr=0x33dae3a0, ready_mask=1) at gdbsupport/event-loop.cc:573 #17 0x000000000157e760 in gdb_wait_for_event (block=1) at gdbsupport/event-loop.cc:694 #18 0x000000000157d464 in gdb_do_one_event (mstimeout=-1) at gdbsupport/event-loop.cc:264 #19 0x0000000000943a84 in start_event_loop () at gdb/main.c:401 #20 0x0000000000943bfc in captured_command_loop () at gdb/main.c:465 #21 0x000000000094567c in captured_main (data=0xfffffbea23e8) at gdb/main.c:1335 #22 0x0000000000945700 in gdb_main (args=0xfffffbea23e8) at gdb/main.c:1354 #23 0x0000000000423ab4 in main (argc=14, argv=0xfffffbea2578) at gdb/gdb.c:39 ... AFAIU, there's a race between the two threads on gdb_stderr: - the DAP thread samples the gdb_stderr value, and uses it a bit later to print to - the gdb main thread changes the gdb_stderr value forth and back, using a temporary value for string capture purposes The non-sound stream value is caused by gdb_stderr being sampled while pointing to a str_file object, and used once the str_file object is already destroyed. The error here is that the DAP thread attempts to print to gdb_stderr. Fix this by adding a thread_wrapper that: - catches all exceptions and logs them to dap.log, and - while we're at it, logs when exiting and using the thread_wrapper for each DAP thread. Tested on aarch64-linux. Approved-By: Tom Tromey <[email protected]>

When running test-case gdb.reverse/func-map-to-same-line.exp on arm-linux with target board unix/-mthumb, we run into: ... (gdb) reverse-step func2 () at func-map-to-same-line.c:26 26 { (gdb) FAIL: gdb.reverse/func-map-to-same-line.exp: \ column_info_flag=column-info: step-test: reverse-step into func2 ... The FAIL is caused by incorrect recording of this insn: ... 4f6: f85d 7b04 ldr.w r7, [sp], #4 ... The insn updates the sp, but we don't record this: ... $ gdb -q -batch func-map-to-same-line \ -ex "b *func2+8" \ -ex run \ -ex record \ -ex "set debug record 2" \ -ex stepi Breakpoint 1 at 0x4f6: file func-map-to-same-line.c, line 27. Breakpoint 1, 0xaaaaa4f6 in func2 () at func-map-to-same-line.c:27 27 } /* END FUNC2 */ Process record: arm_process_record addr = 0xaaaaa4f6 Process record: add register num = 15 to record list. Process record: record_full_arch_list_add 0xabc6c460. Process record: add register num = 7 to record list. Process record: record_full_arch_list_add 0xabc3b868. Process record: add register num = 25 to record list. ... [ Note that sp is r13, and we see here only r15 (pc), r7, and r25 (ps). ] The problem is that the specific insn, an LDR(immediate) T4, is not handled in thumb2_record_ld_word. Fix this by detecting the insn in thumb2_record_ld_word, and recording the updated base register. Tested on arm-linux. Reported-By: Thiago Jung Bauermann <[email protected]> Approved-By: Luis Machado <[email protected]> PR tdep/31278 Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31278

When running test-case gdb.dap/eof.exp, we're likely to get a coredump due to a segfault in new_threadstate. At the point of the core dump, the gdb main thread looks like: ... (gdb) bt #0 0x0000fffee30d2280 in __pthread_kill_implementation () from /lib64/libc.so.6 #1 0x0000fffee3085800 [PAC] in raise () from /lib64/libc.so.6 #2 0x00000000007b03e8 [PAC] in handle_fatal_signal (sig=11) at gdb/event-top.c:926 #3 0x00000000007b0470 in handle_sigsegv (sig=11) at gdb/event-top.c:976 #4 <signal handler called> #5 0x0000fffee3a4db14 in new_threadstate () from /lib64/libpython3.12.so.1.0 XUANTIE-RV#6 0x0000fffee3ab0548 [PAC] in PyGILState_Ensure () from /lib64/libpython3.12.so.1.0 #7 0x0000000000a6d034 [PAC] in gdbpy_gil::gdbpy_gil (this=0xffffcb279738) at gdb/python/python-internal.h:787 #8 0x0000000000ab87ac in gdbpy_event::~gdbpy_event (this=0xfffea8001ee0, __in_chrg=<optimized out>) at gdb/python/python.c:1051 #9 0x0000000000ab9460 in std::_Function_base::_Base_manager<...>::_M_destroy (__victim=...) at /usr/include/c++/13/bits/std_function.h:175 #10 0x0000000000ab92dc in std::_Function_base::_Base_manager<...>::_M_manager (__dest=..., __source=..., __op=std::__destroy_functor) at /usr/include/c++/13/bits/std_function.h:203 #11 0x0000000000ab8f14 in std::_Function_handler<...>::_M_manager(...) (...) at /usr/include/c++/13/bits/std_function.h:282 #12 0x000000000042dd9c in std::_Function_base::~_Function_base (this=0xfffea8001c10, __in_chrg=<optimized out>) at /usr/include/c++/13/bits/std_function.h:244 #13 0x000000000042e654 in std::function<void ()>::~function() (this=0xfffea8001c10, __in_chrg=<optimized out>) at /usr/include/c++/13/bits/std_function.h:334 #14 0x0000000000b68e60 in std::_Destroy<std::function<void ()> >(...) (...) at /usr/include/c++/13/bits/stl_construct.h:151 #15 0x0000000000b68cd0 in std::_Destroy_aux<false>::__destroy<...>(...) (...) at /usr/include/c++/13/bits/stl_construct.h:163 #16 0x0000000000b689d8 in std::_Destroy<...>(...) (...) at /usr/include/c++/13/bits/stl_construct.h:196 #17 0x0000000000b68414 in std::_Destroy<...>(...) (...) at /usr/include/c++/13/bits/alloc_traits.h:948 #18 std::vector<...>::~vector() (this=0x2a183c8 <runnables>) at /usr/include/c++/13/bits/stl_vector.h:732 #19 0x0000fffee3088370 in __run_exit_handlers () from /lib64/libc.so.6 #20 0x0000fffee3088450 [PAC] in exit () from /lib64/libc.so.6 #21 0x0000000000c95600 [PAC] in quit_force (exit_arg=0x0, from_tty=0) at gdb/top.c:1822 #22 0x0000000000609140 in quit_command (args=0x0, from_tty=0) at gdb/cli/cli-cmds.c:508 #23 0x0000000000c926a4 in quit_cover () at gdb/top.c:300 #24 0x00000000007b09d4 in async_disconnect (arg=0x0) at gdb/event-top.c:1230 #25 0x0000000000548acc in invoke_async_signal_handlers () at gdb/async-event.c:234 #26 0x000000000157d2d4 in gdb_do_one_event (mstimeout=-1) at gdbsupport/event-loop.cc:199 #27 0x0000000000943a84 in start_event_loop () at gdb/main.c:401 #28 0x0000000000943bfc in captured_command_loop () at gdb/main.c:465 #29 0x000000000094567c in captured_main (data=0xffffcb279d08) at gdb/main.c:1335 #30 0x0000000000945700 in gdb_main (args=0xffffcb279d08) at gdb/main.c:1354 #31 0x0000000000423ab4 in main (argc=14, argv=0xffffcb279e98) at gdb/gdb.c:39 ... The direct cause of the segfault is calling PyGILState_Ensure after calling Py_Finalize. AFAICT the problem is a race between the gdb main thread and DAP's JSON writer thread. On one side, we have the following events: - DAP's JSON reader thread reads an EOF, and lets DAP's main thread known by writing None into read_queue - DAP's main thread lets DAP's JSON writer thread known by writing None into write_queue - DAP's JSON writer thread sees the None in its queue, and calls send_gdb("quit") - a corresponding gdbpy_event is deposited in the runnables vector, to be run by the gdb main thread On the other side, we have the following events: - the gdb main thread receives a SIGHUP - the corresponding handler calls quit_force, which calls do_final_cleanups - one of the final cleanups is finalize_python, which calls Py_Finalize - quit_force calls exit, which triggers the exit handlers - one of the exit handlers is the destructor of the runnables vector - destruction of the vector triggers destruction of the remaining element - the remaining element is a gdbpy_event, and the destructor (indirectly) calls PyGILState_Ensure It's good to note that both events (EOF and SIGHUP) are caused by this line in the test-case: ... catch "close -i $gdb_spawn_id" ... where "expect close" closes the stdin and stdout file descriptors, which causes the SIGHUP to be send. So, for the system I'm running this on, the send_gdb("quit") is actually not needed. I'm not sure if we support any systems where it's actually needed. Fix this by removing the send_gdb("quit"). Tested on aarch64-linux. PR dap/31306 Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31306

When building gdb with -O0 -fsanitize=address, and running test-case gdb.ada/uninitialized_vars.exp, I run into: ... (gdb) info locals a = 0 z = (a => 1, b => false, c => 2.0) ================================================================= ==66372==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x602000097f58 at pc 0xffff52c0da1c bp 0xffffc90a1d40 sp 0xffffc90a1d80 READ of size 4 at 0x602000097f58 thread T0 #0 0xffff52c0da18 in memmove (/lib64/libasan.so.8+0x6da18) #1 0xbcab24 in unsigned char* std::__copy_move_backward<false, true, std::random_access_iterator_tag>::__copy_move_b<unsigned char const, unsigned char>(unsigned char const*, unsigned char const*, unsigned char*) /usr/include/c++/13/bits/stl_algobase.h:748 #2 0xbc9bf4 in unsigned char* std::__copy_move_backward_a2<false, unsigned char const*, unsigned char*>(unsigned char const*, unsigned char const*, unsigned char*) /usr/include/c++/13/bits/stl_algobase.h:769 #3 0xbc898c in unsigned char* std::__copy_move_backward_a1<false, unsigned char const*, unsigned char*>(unsigned char const*, unsigned char const*, unsigned char*) /usr/include/c++/13/bits/stl_algobase.h:778 #4 0xbc715c in unsigned char* std::__copy_move_backward_a<false, unsigned char const*, unsigned char*>(unsigned char const*, unsigned char const*, unsigned char*) /usr/include/c++/13/bits/stl_algobase.h:807 #5 0xbc4e6c in unsigned char* std::copy_backward<unsigned char const*, unsigned char*>(unsigned char const*, unsigned char const*, unsigned char*) /usr/include/c++/13/bits/stl_algobase.h:867 XUANTIE-RV#6 0xbc2934 in void gdb::copy<unsigned char const, unsigned char>(gdb::array_view<unsigned char const>, gdb::array_view<unsigned char>) gdb/../gdbsupport/array-view.h:223 #7 0x20e0100 in value::contents_copy_raw(value*, long, long, long) gdb/value.c:1239 #8 0x20e9830 in value::primitive_field(long, int, type*) gdb/value.c:3078 #9 0x20e98f8 in value_field(value*, int) gdb/value.c:3095 #10 0xcafd64 in print_field_values gdb/ada-valprint.c:658 #11 0xcb0fa0 in ada_val_print_struct_union gdb/ada-valprint.c:857 #12 0xcb1bb4 in ada_value_print_inner(value*, ui_file*, int, value_print_options const*) gdb/ada-valprint.c:1042 #13 0xc66e04 in ada_language::value_print_inner(value*, ui_file*, int, value_print_options const*) const (/home/vries/gdb/build/gdb/gdb+0xc66e04) #14 0x20ca1e8 in common_val_print(value*, ui_file*, int, value_print_options const*, language_defn const*) gdb/valprint.c:1092 #15 0x20caabc in common_val_print_checked(value*, ui_file*, int, value_print_options const*, language_defn const*) gdb/valprint.c:1184 #16 0x196c524 in print_variable_and_value(char const*, symbol*, frame_info_ptr, ui_file*, int) gdb/printcmd.c:2355 #17 0x1d99ca0 in print_variable_and_value_data::operator()(char const*, symbol*) gdb/stack.c:2308 #18 0x1dabca0 in gdb::function_view<void (char const*, symbol*)>::bind<print_variable_and_value_data>(print_variable_and_value_data&)::{lambda(gdb::fv_detail::erased_callable, char const*, symbol*)#1}::operator()(gdb::fv_detail::erased_callable, char const*, symbol*) const gdb/../gdbsupport/function-view.h:305 #19 0x1dabd14 in gdb::function_view<void (char const*, symbol*)>::bind<print_variable_and_value_data>(print_variable_and_value_data&)::{lambda(gdb::fv_detail::erased_callable, char const*, symbol*)#1}::_FUN(gdb::fv_detail::erased_callable, char const*, symbol*) gdb/../gdbsupport/function-view.h:299 #20 0x1dab34c in gdb::function_view<void (char const*, symbol*)>::operator()(char const*, symbol*) const gdb/../gdbsupport/function-view.h:289 #21 0x1d9963c in iterate_over_block_locals gdb/stack.c:2240 #22 0x1d99790 in iterate_over_block_local_vars(block const*, gdb::function_view<void (char const*, symbol*)>) gdb/stack.c:2259 #23 0x1d9a598 in print_frame_local_vars gdb/stack.c:2380 #24 0x1d9afac in info_locals_command(char const*, int) gdb/stack.c:2458 #25 0xfd7b30 in do_simple_func gdb/cli/cli-decode.c:95 #26 0xfe5a2c in cmd_func(cmd_list_element*, char const*, int) gdb/cli/cli-decode.c:2735 #27 0x1f03790 in execute_command(char const*, int) gdb/top.c:575 #28 0x1384080 in command_handler(char const*) gdb/event-top.c:566 #29 0x1384e2c in command_line_handler(std::unique_ptr<char, gdb::xfree_deleter<char> >&&) gdb/event-top.c:802 #30 0x1f731e4 in tui_command_line_handler gdb/tui/tui-interp.c:104 #31 0x1382a58 in gdb_rl_callback_handler gdb/event-top.c:259 #32 0x21dbb80 in rl_callback_read_char readline/readline/callback.c:290 #33 0x1382510 in gdb_rl_callback_read_char_wrapper_noexcept gdb/event-top.c:195 #34 0x138277c in gdb_rl_callback_read_char_wrapper gdb/event-top.c:234 #35 0x1fe9b40 in stdin_event_handler gdb/ui.c:155 #36 0x35ff1bc in handle_file_event gdbsupport/event-loop.cc:573 #37 0x35ff9d8 in gdb_wait_for_event gdbsupport/event-loop.cc:694 #38 0x35fd284 in gdb_do_one_event(int) gdbsupport/event-loop.cc:264 #39 0x1768080 in start_event_loop gdb/main.c:408 #40 0x17684c4 in captured_command_loop gdb/main.c:472 #41 0x176cfc8 in captured_main gdb/main.c:1342 #42 0x176d088 in gdb_main(captured_main_args*) gdb/main.c:1361 #43 0xb73edc in main gdb/gdb.c:39 #44 0xffff519b09d8 in __libc_start_call_main (/lib64/libc.so.6+0x309d8) #45 0xffff519b0aac in __libc_start_main@@GLIBC_2.34 (/lib64/libc.so.6+0x30aac) #46 0xb73c2c in _start (/home/vries/gdb/build/gdb/gdb+0xb73c2c) 0x602000097f58 is located 0 bytes after 8-byte region [0x602000097f50,0x602000097f58) allocated by thread T0 here: #0 0xffff52c65218 in calloc (/lib64/libasan.so.8+0xc5218) #1 0xcbc278 in xcalloc gdb/alloc.c:97 #2 0x35f21e8 in xzalloc(unsigned long) gdbsupport/common-utils.cc:29 #3 0x20de270 in value::allocate_contents(bool) gdb/value.c:937 #4 0x20edc08 in value::fetch_lazy() gdb/value.c:4033 #5 0x20dadc0 in value::entirely_covered_by_range_vector(std::vector<range, std::allocator<range> > const&) gdb/value.c:229 XUANTIE-RV#6 0xcb2298 in value::entirely_optimized_out() gdb/value.h:560 #7 0x20ca6fc in value_check_printable gdb/valprint.c:1133 #8 0x20caa8c in common_val_print_checked(value*, ui_file*, int, value_print_options const*, language_defn const*) gdb/valprint.c:1182 #9 0x196c524 in print_variable_and_value(char const*, symbol*, frame_info_ptr, ui_file*, int) gdb/printcmd.c:2355 #10 0x1d99ca0 in print_variable_and_value_data::operator()(char const*, symbol*) gdb/stack.c:2308 #11 0x1dabca0 in gdb::function_view<void (char const*, symbol*)>::bind<print_variable_and_value_data>(print_variable_and_value_data&)::{lambda(gdb::fv_detail::erased_callable, char const*, symbol*)#1}::operator()(gdb::fv_detail::erased_callable, char const*, symbol*) const gdb/../gdbsupport/function-view.h:305 #12 0x1dabd14 in gdb::function_view<void (char const*, symbol*)>::bind<print_variable_and_value_data>(print_variable_and_value_data&)::{lambda(gdb::fv_detail::erased_callable, char const*, symbol*)#1}::_FUN(gdb::fv_detail::erased_callable, char const*, symbol*) gdb/../gdbsupport/function-view.h:299 #13 0x1dab34c in gdb::function_view<void (char const*, symbol*)>::operator()(char const*, symbol*) const gdb/../gdbsupport/function-view.h:289 #14 0x1d9963c in iterate_over_block_locals gdb/stack.c:2240 #15 0x1d99790 in iterate_over_block_local_vars(block const*, gdb::function_view<void (char const*, symbol*)>) gdb/stack.c:2259 #16 0x1d9a598 in print_frame_local_vars gdb/stack.c:2380 #17 0x1d9afac in info_locals_command(char const*, int) gdb/stack.c:2458 #18 0xfd7b30 in do_simple_func gdb/cli/cli-decode.c:95 #19 0xfe5a2c in cmd_func(cmd_list_element*, char const*, int) gdb/cli/cli-decode.c:2735 #20 0x1f03790 in execute_command(char const*, int) gdb/top.c:575 #21 0x1384080 in command_handler(char const*) gdb/event-top.c:566 #22 0x1384e2c in command_line_handler(std::unique_ptr<char, gdb::xfree_deleter<char> >&&) gdb/event-top.c:802 #23 0x1f731e4 in tui_command_line_handler gdb/tui/tui-interp.c:104 #24 0x1382a58 in gdb_rl_callback_handler gdb/event-top.c:259 #25 0x21dbb80 in rl_callback_read_char readline/readline/callback.c:290 #26 0x1382510 in gdb_rl_callback_read_char_wrapper_noexcept gdb/event-top.c:195 #27 0x138277c in gdb_rl_callback_read_char_wrapper gdb/event-top.c:234 #28 0x1fe9b40 in stdin_event_handler gdb/ui.c:155 #29 0x35ff1bc in handle_file_event gdbsupport/event-loop.cc:573 SUMMARY: AddressSanitizer: heap-buffer-overflow (/lib64/libasan.so.8+0x6da18) in memmove ... The error happens when trying to print either variable y or y2: ... type Variable_Record (A : Boolean := True) is record case A is when True => B : Integer; when False => C : Float; D : Integer; end case; end record; Y : Variable_Record := (A => True, B => 1); Y2 : Variable_Record := (A => False, C => 1.0, D => 2); ... when the variables are uninitialized. The error happens only when printing the entire variable: ... (gdb) p y.a $2 = 216 (gdb) p y.b There is no member named b. (gdb) p y.c $3 = 9.18340949e-41 (gdb) p y.d $4 = 1 (gdb) p y <AddressSanitizer: heap-buffer-overflow> ... The error happens as follows: - field a functions as discriminant, choosing either the b, or c+d variant. - when y.a happens to be set to 216, as above, gdb interprets this as the variable having the c+d variant (which is why trying to print y.b fails). - when printing y, gdb allocates a value, copies the bytes into it from the target, and then prints the value. - gdb allocates the value using the type size, which is 8. It's 8 because that's what the DW_AT_byte_size indicates. Note that for valid values of a, it gives correct results: if a is 0 (c+d variant), size is 12, if a is 1 (b variant), size is 8. - gdb tries to print field d, which is at an 8 byte offset, and that results in a out-of-bounds access for the allocated 8-byte value. Fix this by handling this case in value::contents_copy_raw, such that we have: ... (gdb) p y $1 = (a => 24, c => 9.18340949e-41, d => <error reading variable: access outside bounds of object>) ... An alternative (additional) fix could be this: in compute_variant_fields_inner gdb reads the discriminant y.a to decide which variant is active. It would be nice to detect that the value (y.a == 24) is not a valid Boolean, and give up on choosing a variant altoghether. However, the situation regarding the internal type CODE_TYPE_BOOL is currently ambiguous (see PR31282) and it's not possible to reliably decide what valid values are. The test-case source file gdb.ada/uninitialized-variable-record/parse.adb is a reduced version of gdb.ada/uninitialized_vars/parse.adb, so it copies the copyright years. Note that the test-case needs gcc-12 or newer, it's unsupported for older gcc versions. [ So, it would be nice to rewrite it into a dwarf assembly test-case. ] The test-case loops over all languages. This is inherited from an earlier attempt to fix this, which had language-specific fixes (in print_field_values, cp_print_value_fields, pascal_object_print_value_fields and f_language::value_print_inner). I've left this in, but I suppose it's not strictly necessary anymore. Tested on x86_64-linux. PR exp/31258 Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31258

From the Python API, we can execute GDB commands via gdb.execute. If the command gives an exception, however, we need to recover the GDB prompt and enable stdin, because the exception does not reach top-level GDB or normal_stop. This was done in commit commit 1ba1ac8 Author: Andrew Burgess <[email protected]> Date: Tue Nov 19 11:17:20 2019 +0000 gdb: Enable stdin on exception in execute_gdb_command with the following code: catch (const gdb_exception &except) { /* If an exception occurred then we won't hit normal_stop (), or have an exception reach the top level of the event loop, which are the two usual places in which stdin would be re-enabled. So, before we convert the exception and continue back in Python, we should re-enable stdin here. */ async_enable_stdin (); GDB_PY_HANDLE_EXCEPTION (except); } In this patch, we explain what happens when we run a GDB command in the context of a synchronous command, e.g. via Python observer notifications. As an example, suppose we have the following objfile event listener, specified in a file named file.py: ~~~ import gdb class MyListener: def __init__(self): gdb.events.new_objfile.connect(self.handle_new_objfile_event) self.processed_objfile = False def handle_new_objfile_event(self, event): if self.processed_objfile: return print("loading " + event.new_objfile.filename) self.processed_objfile = True gdb.execute('add-inferior -no-connection') gdb.execute('inferior 2') gdb.execute('target remote | gdbserver - /tmp/a.out') gdb.execute('inferior 1') the_listener = MyListener() ~~~ Using this Python file, we see the behavior below: $ gdb -q -ex "source file.py" -ex "run" --args a.out Reading symbols from a.out... Starting program: /tmp/a.out loading /lib64/ld-linux-x86-64.so.2 [New inferior 2] Added inferior 2 [Switching to inferior 2 [<null>] (<noexec>)] stdin/stdout redirected Process /tmp/a.out created; pid = 3075406 Remote debugging using stdio Reading /tmp/a.out from remote target... ... [Switching to inferior 1 [process 3075400] (/tmp/a.out)] [Switching to thread 1.1 (process 3075400)] #0 0x00007ffff7fe3290 in ?? () from /lib64/ld-linux-x86-64.so.2 (gdb) [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1". [Inferior 1 (process 3075400) exited normally] Note how the GDB prompt comes in-between the debugger output. We have this obscure behavior, because the executed command, "target remote", triggers an invocation of `normal_stop` that enables stdin. After that, however, the Python notification context completes and GDB continues with its normal flow of executing the 'run' command. This can be seen in the call stack below: (top-gdb) bt #0 async_enable_stdin () at src/gdb/event-top.c:523 #1 0x00005555561c3acd in normal_stop () at src/gdb/infrun.c:9432 #2 0x00005555561b328e in start_remote (from_tty=0) at src/gdb/infrun.c:3801 #3 0x0000555556441224 in remote_target::start_remote_1 (this=0x5555587882e0, from_tty=0, extended_p=0) at src/gdb/remote.c:5225 #4 0x000055555644166c in remote_target::start_remote (this=0x5555587882e0, from_tty=0, extended_p=0) at src/gdb/remote.c:5316 #5 0x00005555564430cf in remote_target::open_1 (name=0x55555878525e "| gdbserver - /tmp/a.out", from_tty=0, extended_p=0) at src/gdb/remote.c:6175 XUANTIE-RV#6 0x0000555556441707 in remote_target::open (name=0x55555878525e "| gdbserver - /tmp/a.out", from_tty=0) at src/gdb/remote.c:5338 #7 0x00005555565ea63f in open_target (args=0x55555878525e "| gdbserver - /tmp/a.out", from_tty=0, command=0x555558589280) at src/gdb/target.c:824 #8 0x0000555555f0d89a in cmd_func (cmd=0x555558589280, args=0x55555878525e "| gdbserver - /tmp/a.out", from_tty=0) at src/gdb/cli/cli-decode.c:2735 #9 0x000055555661fb42 in execute_command (p=0x55555878529e "t", from_tty=0) at src/gdb/top.c:575 #10 0x0000555555f1a506 in execute_control_command_1 (cmd=0x555558756f00, from_tty=0) at src/gdb/cli/cli-script.c:529 #11 0x0000555555f1abea in execute_control_command (cmd=0x555558756f00, from_tty=0) at src/gdb/cli/cli-script.c:701 #12 0x0000555555f19fc7 in execute_control_commands (cmdlines=0x555558756f00, from_tty=0) at src/gdb/cli/cli-script.c:411 #13 0x0000555556400d91 in execute_gdb_command (self=0x7ffff43b5d00, args=0x7ffff440ab60, kw=0x0) at src/gdb/python/python.c:700 #14 0x00007ffff7a96023 in ?? () from /lib/x86_64-linux-gnu/libpython3.10.so.1.0 #15 0x00007ffff7a4dadc in _PyObject_MakeTpCall () from /lib/x86_64-linux-gnu/libpython3.10.so.1.0 #16 0x00007ffff79e9a1c in _PyEval_EvalFrameDefault () from /lib/x86_64-linux-gnu/libpython3.10.so.1.0 #17 0x00007ffff7b303af in ?? () from /lib/x86_64-linux-gnu/libpython3.10.so.1.0 #18 0x00007ffff7a50358 in ?? () from /lib/x86_64-linux-gnu/libpython3.10.so.1.0 #19 0x00007ffff7a4f3f4 in ?? () from /lib/x86_64-linux-gnu/libpython3.10.so.1.0 #20 0x00007ffff7a4f883 in PyObject_CallFunctionObjArgs () from /lib/x86_64-linux-gnu/libpython3.10.so.1.0 #21 0x00005555563a9758 in evpy_emit_event (event=0x7ffff42b5430, registry=0x7ffff42b4690) at src/gdb/python/py-event.c:104 #22 0x00005555563cb874 in emit_new_objfile_event (objfile=0x555558761700) at src/gdb/python/py-newobjfileevent.c:52 #23 0x00005555563b53bc in python_new_objfile (objfile=0x555558761700) at src/gdb/python/py-inferior.c:195 #24 0x0000555555d6dff0 in std::__invoke_impl<void, void (*&)(objfile*), objfile*> (__f=@0x5555585b5860: 0x5555563b5360 <python_new_objfile(objfile*)>) at /usr/include/c++/11/bits/invoke.h:61 #25 0x0000555555d6be18 in std::__invoke_r<void, void (*&)(objfile*), objfile*> (__fn=@0x5555585b5860: 0x5555563b5360 <python_new_objfile(objfile*)>) at /usr/include/c++/11/bits/invoke.h:111 #26 0x0000555555d69661 in std::_Function_handler<void (objfile*), void (*)(objfile*)>::_M_invoke(std::_Any_data const&, objfile*&&) (__functor=..., __args#0=@0x7fffffffd080: 0x555558761700) at /usr/include/c++/11/bits/std_function.h:290 #27 0x0000555556314caf in std::function<void (objfile*)>::operator()(objfile*) const (this=0x5555585b5860, __args#0=0x555558761700) at /usr/include/c++/11/bits/std_function.h:590 #28 0x000055555631444e in gdb::observers::observable<objfile*>::notify (this=0x55555836eea0 <gdb::observers::new_objfile>, args#0=0x555558761700) at src/gdb/../gdbsupport/observable.h:166 #29 0x0000555556599b3f in symbol_file_add_with_addrs (abfd=..., name=0x55555875d310 "/lib64/ld-linux-x86-64.so.2", add_flags=..., addrs=0x7fffffffd2f0, flags=..., parent=0x0) at src/gdb/symfile.c:1125 #30 0x0000555556599ca4 in symbol_file_add_from_bfd (abfd=..., name=0x55555875d310 "/lib64/ld-linux-x86-64.so.2", add_flags=..., addrs=0x7fffffffd2f0, flags=..., parent=0x0) at src/gdb/symfile.c:1160 #31 0x0000555556546371 in solib_read_symbols (so=..., flags=...) at src/gdb/solib.c:692 #32 0x0000555556546f0f in solib_add (pattern=0x0, from_tty=0, readsyms=1) at src/gdb/solib.c:1015 #33 0x0000555556539891 in enable_break (info=0x55555874e180, from_tty=0) at src/gdb/solib-svr4.c:2416 #34 0x000055555653b305 in svr4_solib_create_inferior_hook (from_tty=0) at src/gdb/solib-svr4.c:3058 #35 0x0000555556547cee in solib_create_inferior_hook (from_tty=0) at src/gdb/solib.c:1217 #36 0x0000555556196f6a in post_create_inferior (from_tty=0) at src/gdb/infcmd.c:275 #37 0x0000555556197670 in run_command_1 (args=0x0, from_tty=1, run_how=RUN_NORMAL) at src/gdb/infcmd.c:486 #38 0x000055555619783f in run_command (args=0x0, from_tty=1) at src/gdb/infcmd.c:512 #39 0x0000555555f0798d in do_simple_func (args=0x0, from_tty=1, c=0x555558567510) at src/gdb/cli/cli-decode.c:95 #40 0x0000555555f0d89a in cmd_func (cmd=0x555558567510, args=0x0, from_tty=1) at src/gdb/cli/cli-decode.c:2735 #41 0x000055555661fb42 in execute_command (p=0x7fffffffe2c4 "", from_tty=1) at src/gdb/top.c:575 #42 0x000055555626303b in catch_command_errors (command=0x55555661f4ab <execute_command(char const*, int)>, arg=0x7fffffffe2c1 "run", from_tty=1, do_bp_actions=true) at src/gdb/main.c:513 #43 0x000055555626328a in execute_cmdargs (cmdarg_vec=0x7fffffffdaf0, file_type=CMDARG_FILE, cmd_type=CMDARG_COMMAND, ret=0x7fffffffda3c) at src/gdb/main.c:612 #44 0x0000555556264849 in captured_main_1 (context=0x7fffffffdd40) at src/gdb/main.c:1293 #45 0x0000555556264a7f in captured_main (data=0x7fffffffdd40) at src/gdb/main.c:1314 #46 0x0000555556264b2e in gdb_main (args=0x7fffffffdd40) at src/gdb/main.c:1343 #47 0x0000555555ceccab in main (argc=9, argv=0x7fffffffde78) at src/gdb/gdb.c:39 (top-gdb) The use of the "target remote" command here is just an example. In principle, we would reproduce the problem with any command that triggers an invocation of `normal_stop`. To omit enabling the stdin in `normal_stop`, we would have to check the context we are in. Since we cannot do that, we add a new field to `struct ui` to track whether the prompt was already blocked, and set the tracker flag in the Python context before executing a GDB command. After applying this patch, the output becomes ... Reading symbols from a.out... Starting program: /tmp/a.out loading /lib64/ld-linux-x86-64.so.2 [New inferior 2] Added inferior 2 [Switching to inferior 2 [<null>] (<noexec>)] stdin/stdout redirected Process /tmp/a.out created; pid = 3032261 Remote debugging using stdio Reading /tmp/a.out from remote target... ... [Switching to inferior 1 [process 3032255] (/tmp/a.out)] [Switching to thread 1.1 (process 3032255)] #0 0x00007ffff7fe3290 in ?? () from /lib64/ld-linux-x86-64.so.2 [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1". [Inferior 1 (process 3032255) exited normally] (gdb) Let's now consider a secondary scenario, where the command executed from the Python raises an error. As an example, suppose we have the Python file below: def handle_new_objfile_event(self, event): ... print("loading " + event.new_objfile.filename) self.processed_objfile = True gdb.execute('print a') The executed command, "print a", gives an error because "a" is not defined. Without this patch, we see the behavior below, where the prompt is again placed incorrectly: ... Reading symbols from /tmp/a.out... Starting program: /tmp/a.out loading /lib64/ld-linux-x86-64.so.2 Python Exception <class 'gdb.error'>: No symbol "a" in current context. (gdb) [Inferior 1 (process 3980401) exited normally] This time, `async_enable_stdin` is called from the 'catch' block in `execute_gdb_command`: (top-gdb) bt #0 async_enable_stdin () at src/gdb/event-top.c:523 #1 0x0000555556400f0a in execute_gdb_command (self=0x7ffff43b5d00, args=0x7ffff440ab60, kw=0x0) at src/gdb/python/python.c:713 #2 0x00007ffff7a96023 in ?? () from /lib/x86_64-linux-gnu/libpython3.10.so.1.0 #3 0x00007ffff7a4dadc in _PyObject_MakeTpCall () from /lib/x86_64-linux-gnu/libpython3.10.so.1.0 #4 0x00007ffff79e9a1c in _PyEval_EvalFrameDefault () from /lib/x86_64-linux-gnu/libpython3.10.so.1.0 #5 0x00007ffff7b303af in ?? () from /lib/x86_64-linux-gnu/libpython3.10.so.1.0 XUANTIE-RV#6 0x00007ffff7a50358 in ?? () from /lib/x86_64-linux-gnu/libpython3.10.so.1.0 #7 0x00007ffff7a4f3f4 in ?? () from /lib/x86_64-linux-gnu/libpython3.10.so.1.0 #8 0x00007ffff7a4f883 in PyObject_CallFunctionObjArgs () from /lib/x86_64-linux-gnu/libpython3.10.so.1.0 #9 0x00005555563a9758 in evpy_emit_event (event=0x7ffff42b5430, registry=0x7ffff42b4690) at src/gdb/python/py-event.c:104 #10 0x00005555563cb874 in emit_new_objfile_event (objfile=0x555558761410) at src/gdb/python/py-newobjfileevent.c:52 #11 0x00005555563b53bc in python_new_objfile (objfile=0x555558761410) at src/gdb/python/py-inferior.c:195 #12 0x0000555555d6dff0 in std::__invoke_impl<void, void (*&)(objfile*), objfile*> (__f=@0x5555585b5860: 0x5555563b5360 <python_new_objfile(objfile*)>) at /usr/include/c++/11/bits/invoke.h:61 #13 0x0000555555d6be18 in std::__invoke_r<void, void (*&)(objfile*), objfile*> (__fn=@0x5555585b5860: 0x5555563b5360 <python_new_objfile(objfile*)>) at /usr/include/c++/11/bits/invoke.h:111 #14 0x0000555555d69661 in std::_Function_handler<void (objfile*), void (*)(objfile*)>::_M_invoke(std::_Any_data const&, objfile*&&) (__functor=..., __args#0=@0x7fffffffd080: 0x555558761410) at /usr/include/c++/11/bits/std_function.h:290 #15 0x0000555556314caf in std::function<void (objfile*)>::operator()(objfile*) const (this=0x5555585b5860, __args#0=0x555558761410) at /usr/include/c++/11/bits/std_function.h:590 #16 0x000055555631444e in gdb::observers::observable<objfile*>::notify (this=0x55555836eea0 <gdb::observers::new_objfile>, args#0=0x555558761410) at src/gdb/../gdbsupport/observable.h:166 #17 0x0000555556599b3f in symbol_file_add_with_addrs (abfd=..., name=0x55555875d020 "/lib64/ld-linux-x86-64.so.2", add_flags=..., addrs=0x7fffffffd2f0, flags=..., parent=0x0) at src/gdb/symfile.c:1125 #18 0x0000555556599ca4 in symbol_file_add_from_bfd (abfd=..., name=0x55555875d020 "/lib64/ld-linux-x86-64.so.2", add_flags=..., addrs=0x7fffffffd2f0, flags=..., parent=0x0) at src/gdb/symfile.c:1160 #19 0x0000555556546371 in solib_read_symbols (so=..., flags=...) at src/gdb/solib.c:692 #20 0x0000555556546f0f in solib_add (pattern=0x0, from_tty=0, readsyms=1) at src/gdb/solib.c:1015 #21 0x0000555556539891 in enable_break (info=0x55555874a670, from_tty=0) at src/gdb/solib-svr4.c:2416 #22 0x000055555653b305 in svr4_solib_create_inferior_hook (from_tty=0) at src/gdb/solib-svr4.c:3058 #23 0x0000555556547cee in solib_create_inferior_hook (from_tty=0) at src/gdb/solib.c:1217 #24 0x0000555556196f6a in post_create_inferior (from_tty=0) at src/gdb/infcmd.c:275 #25 0x0000555556197670 in run_command_1 (args=0x0, from_tty=1, run_how=RUN_NORMAL) at src/gdb/infcmd.c:486 #26 0x000055555619783f in run_command (args=0x0, from_tty=1) at src/gdb/infcmd.c:512 #27 0x0000555555f0798d in do_simple_func (args=0x0, from_tty=1, c=0x555558567510) at src/gdb/cli/cli-decode.c:95 #28 0x0000555555f0d89a in cmd_func (cmd=0x555558567510, args=0x0, from_tty=1) at src/gdb/cli/cli-decode.c:2735 #29 0x000055555661fb42 in execute_command (p=0x7fffffffe2c4 "", from_tty=1) at src/gdb/top.c:575 #30 0x000055555626303b in catch_command_errors (command=0x55555661f4ab <execute_command(char const*, int)>, arg=0x7fffffffe2c1 "run", from_tty=1, do_bp_actions=true) at src/gdb/main.c:513 #31 0x000055555626328a in execute_cmdargs (cmdarg_vec=0x7fffffffdaf0, file_type=CMDARG_FILE, cmd_type=CMDARG_COMMAND, ret=0x7fffffffda3c) at src/gdb/main.c:612 #32 0x0000555556264849 in captured_main_1 (context=0x7fffffffdd40) at src/gdb/main.c:1293 #33 0x0000555556264a7f in captured_main (data=0x7fffffffdd40) at src/gdb/main.c:1314 #34 0x0000555556264b2e in gdb_main (args=0x7fffffffdd40) at src/gdb/main.c:1343 #35 0x0000555555ceccab in main (argc=9, argv=0x7fffffffde78) at src/gdb/gdb.c:39 (top-gdb) Again, after we enable stdin, GDB continues with its normal flow of the 'run' command and receives the inferior's exit event, where it would have enabled stdin, if we had not done it prematurely. (top-gdb) bt #0 async_enable_stdin () at src/gdb/event-top.c:523 #1 0x00005555561c3acd in normal_stop () at src/gdb/infrun.c:9432 #2 0x00005555561b5bf1 in fetch_inferior_event () at src/gdb/infrun.c:4700 #3 0x000055555618d6a7 in inferior_event_handler (event_type=INF_REG_EVENT) at src/gdb/inf-loop.c:42 #4 0x000055555620ecdb in handle_target_event (error=0, client_data=0x0) at src/gdb/linux-nat.c:4316 #5 0x0000555556f33035 in handle_file_event (file_ptr=0x5555587024e0, ready_mask=1) at src/gdbsupport/event-loop.cc:573 XUANTIE-RV#6 0x0000555556f3362f in gdb_wait_for_event (block=0) at src/gdbsupport/event-loop.cc:694 #7 0x0000555556f322cd in gdb_do_one_event (mstimeout=-1) at src/gdbsupport/event-loop.cc:217 #8 0x0000555556262df8 in start_event_loop () at src/gdb/main.c:407 #9 0x0000555556262f85 in captured_command_loop () at src/gdb/main.c:471 #10 0x0000555556264a84 in captured_main (data=0x7fffffffdd40) at src/gdb/main.c:1324 #11 0x0000555556264b2e in gdb_main (args=0x7fffffffdd40) at src/gdb/main.c:1343 #12 0x0000555555ceccab in main (argc=9, argv=0x7fffffffde78) at src/gdb/gdb.c:39 (top-gdb) The solution implemented by this patch addresses the problem. After applying the patch, the output becomes $ gdb -q -ex "source file.py" -ex "run" --args a.out Reading symbols from /tmp/a.out... Starting program: /tmp/a.out loading /lib64/ld-linux-x86-64.so.2 Python Exception <class 'gdb.error'>: No symbol "a" in current context. [Inferior 1 (process 3984511) exited normally] (gdb) Regression-tested on X86_64 Linux using the default board file (i.e. unix). Co-Authored-By: Oguzhan Karakaya <[email protected]> Reviewed-By: Guinevere Larsen <[email protected]> Approved-By: Tom Tromey <[email protected]>

…ro linux When running test-case gdb.threads/attach-stopped.exp on aarch64-linux, using the manjaro linux distro, I get: ... (gdb) thread apply all bt^M ^M Thread 2 (Thread 0xffff8d8af120 (LWP 278116) "attach-stopped"):^M #0 0x0000ffff8d964864 in clock_nanosleep () from /usr/lib/libc.so.6^M #1 0x0000ffff8d969cac in nanosleep () from /usr/lib/libc.so.6^M #2 0x0000ffff8d969b68 in sleep () from /usr/lib/libc.so.6^M #3 0x0000aaaade370828 in func (arg=0x0) at attach-stopped.c:29^M #4 0x0000ffff8d930aec in ?? () from /usr/lib/libc.so.6^M #5 0x0000ffff8d99a5dc in ?? () from /usr/lib/libc.so.6^M ^M Thread 1 (Thread 0xffff8db62020 (LWP 278111) "attach-stopped"):^M #0 0x0000ffff8d92d2d8 in ?? () from /usr/lib/libc.so.6^M #1 0x0000ffff8d9324b8 in ?? () from /usr/lib/libc.so.6^M #2 0x0000aaaade37086c in main () at attach-stopped.c:45^M (gdb) FAIL: gdb.threads/attach-stopped.exp: threaded: attach2 to stopped bt ... The problem is that the test-case expects to see start_thread: ... gdb_test "thread apply all bt" ".*sleep.*start_thread.*" \ "$threadtype: attach2 to stopped bt" ... but lack of symbols makes that impossible. Fix this by allowing " in ?? () from " as well. Tested on aarch64-linux. PR testsuite/31451 Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31451

When running test-case gdb.server/connect-with-no-symbol-file.exp on aarch64-linux (specifically, an opensuse leap 15.5 container on a fedora asahi 39 system), I run into: ... (gdb) detach^M Detaching from program: target:connect-with-no-symbol-file, process 185104^M Ending remote debugging.^M terminate called after throwing an instance of 'gdb_exception_error'^M ... The detailed backtrace of the corefile is: ... (gdb) bt #0 0x0000ffff75504f54 in raise () from /lib64/libpthread.so.0 #1 0x00000000007a86b4 in handle_fatal_signal (sig=6) at gdb/event-top.c:926 #2 <signal handler called> #3 0x0000ffff74b977b4 in raise () from /lib64/libc.so.6 #4 0x0000ffff74b98c18 in abort () from /lib64/libc.so.6 #5 0x0000ffff74ea26f4 in __gnu_cxx::__verbose_terminate_handler() () from /usr/lib64/libstdc++.so.6 XUANTIE-RV#6 0x0000ffff74ea011c in ?? () from /usr/lib64/libstdc++.so.6 #7 0x0000ffff74ea0180 in std::terminate() () from /usr/lib64/libstdc++.so.6 #8 0x0000ffff74ea0464 in __cxa_throw () from /usr/lib64/libstdc++.so.6 #9 0x0000000001548870 in throw_it (reason=RETURN_ERROR, error=TARGET_CLOSE_ERROR, fmt=0x16c7810 "Remote connection closed", ap=...) at gdbsupport/common-exceptions.cc:203 #10 0x0000000001548920 in throw_verror (error=TARGET_CLOSE_ERROR, fmt=0x16c7810 "Remote connection closed", ap=...) at gdbsupport/common-exceptions.cc:211 #11 0x0000000001548a00 in throw_error (error=TARGET_CLOSE_ERROR, fmt=0x16c7810 "Remote connection closed") at gdbsupport/common-exceptions.cc:226 #12 0x0000000000ac8f2c in remote_target::readchar (this=0x233d3d90, timeout=2) at gdb/remote.c:9856 #13 0x0000000000ac9f04 in remote_target::getpkt (this=0x233d3d90, buf=0x233d40a8, forever=false, is_notif=0x0) at gdb/remote.c:10326 #14 0x0000000000acf3d0 in remote_target::remote_hostio_send_command (this=0x233d3d90, command_bytes=13, which_packet=17, remote_errno=0xfffff1a3cf38, attachment=0xfffff1a3ce88, attachment_len=0xfffff1a3ce90) at gdb/remote.c:12567 #15 0x0000000000ad03bc in remote_target::fileio_fstat (this=0x233d3d90, fd=3, st=0xfffff1a3d020, remote_errno=0xfffff1a3cf38) at gdb/remote.c:12979 #16 0x0000000000c39878 in target_fileio_fstat (fd=0, sb=0xfffff1a3d020, target_errno=0xfffff1a3cf38) at gdb/target.c:3315 #17 0x00000000007eee5c in target_fileio_stream::stat (this=0x233d4400, abfd=0x2323fc40, sb=0xfffff1a3d020) at gdb/gdb_bfd.c:467 #18 0x00000000007f012c in <lambda(bfd*, void*, stat*)>::operator()(bfd *, void *, stat *) const (__closure=0x0, abfd=0x2323fc40, stream=0x233d4400, sb=0xfffff1a3d020) at gdb/gdb_bfd.c:955 #19 0x00000000007f015c in <lambda(bfd*, void*, stat*)>::_FUN(bfd *, void *, stat *) () at gdb/gdb_bfd.c:956 #20 0x0000000000f9b838 in opncls_bstat (abfd=0x2323fc40, sb=0xfffff1a3d020) at bfd/opncls.c:665 #21 0x0000000000f90adc in bfd_stat (abfd=0x2323fc40, statbuf=0xfffff1a3d020) at bfd/bfdio.c:431 #22 0x000000000065fe20 in reopen_exec_file () at gdb/corefile.c:52 #23 0x0000000000c3a3e8 in generic_mourn_inferior () at gdb/target.c:3642 #24 0x0000000000abf3f0 in remote_unpush_target (target=0x233d3d90) at gdb/remote.c:6067 #25 0x0000000000aca8b0 in remote_target::mourn_inferior (this=0x233d3d90) at gdb/remote.c:10587 #26 0x0000000000c387cc in target_mourn_inferior ( ptid=<error reading variable: Cannot access memory at address 0x2d310>) at gdb/target.c:2738 #27 0x0000000000abfff0 in remote_target::remote_detach_1 (this=0x233d3d90, inf=0x22fce540, from_tty=1) at gdb/remote.c:6421 #28 0x0000000000ac0094 in remote_target::detach (this=0x233d3d90, inf=0x22fce540, from_tty=1) at gdb/remote.c:6436 #29 0x0000000000c37c3c in target_detach (inf=0x22fce540, from_tty=1) at gdb/target.c:2526 #30 0x0000000000860424 in detach_command (args=0x0, from_tty=1) at gdb/infcmd.c:2817 #31 0x000000000060b594 in do_simple_func (args=0x0, from_tty=1, c=0x231431a0) at gdb/cli/cli-decode.c:94 #32 0x00000000006108c8 in cmd_func (cmd=0x231431a0, args=0x0, from_tty=1) at gdb/cli/cli-decode.c:2741 #33 0x0000000000c65a94 in execute_command (p=0x232e52f6 "", from_tty=1) at gdb/top.c:570 #34 0x00000000007a7d2c in command_handler (command=0x232e52f0 "") at gdb/event-top.c:566 #35 0x00000000007a8290 in command_line_handler (rl=...) at gdb/event-top.c:802 #36 0x0000000000c9092c in tui_command_line_handler (rl=...) at gdb/tui/tui-interp.c:103 #37 0x00000000007a750c in gdb_rl_callback_handler (rl=0x23385330 "detach") at gdb/event-top.c:258 #38 0x0000000000d910f4 in rl_callback_read_char () at readline/readline/callback.c:290 #39 0x00000000007a7338 in gdb_rl_callback_read_char_wrapper_noexcept () at gdb/event-top.c:194 #40 0x00000000007a73f0 in gdb_rl_callback_read_char_wrapper (client_data=0x22fbf640) at gdb/event-top.c:233 #41 0x0000000000cbee1c in stdin_event_handler (error=0, client_data=0x22fbf640) at gdb/ui.c:154 #42 0x000000000154ed60 in handle_file_event (file_ptr=0x232be730, ready_mask=1) at gdbsupport/event-loop.cc:572 #43 0x000000000154f21c in gdb_wait_for_event (block=1) at gdbsupport/event-loop.cc:693 #44 0x000000000154dec4 in gdb_do_one_event (mstimeout=-1) at gdbsupport/event-loop.cc:263 #45 0x0000000000910f98 in start_event_loop () at gdb/main.c:400 #46 0x0000000000911130 in captured_command_loop () at gdb/main.c:464 #47 0x0000000000912b5c in captured_main (data=0xfffff1a3db58) at gdb/main.c:1338 #48 0x0000000000912bf4 in gdb_main (args=0xfffff1a3db58) at gdb/main.c:1357 #49 0x00000000004170f4 in main (argc=10, argv=0xfffff1a3dcc8) at gdb/gdb.c:38 (gdb) ... The abort happens because a c++ exception escapes to c code, specifically opncls_bstat in bfd/opncls.c. Compiling with -fexceptions works around this. Fix this by catching the exception just before it escapes, in stat_trampoline and likewise in few similar spot. Add a new template catch_exceptions to do so in a consistent way. Tested on aarch64-linux. Approved-by: Pedro Alves <[email protected]> PR remote/31577 Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31577

Similar to the x86_64 testcases, some .s files contain the corresponding CFI directives. This helps in validating the synthesized CFI by running those tests with and without the --scfi=experimental command line option. GAS issues some diagnostics, enabled by default, with --scfi=experimental. The diagnostics have been added with an intent to help user correct inadvertent errors in their hand-written asm. An error is issued when GAS finds that input asm is not amenable to accurate CFI synthesis. The existing scfi-diag-*.s tests in the gas/testsuite/gas/scfi/x86_64 directory test some SCFI diagnostics already: - (#1) "Warning: SCFI: Asymetrical register restore" - (#2) "Error: SCFI: usage of REG_FP as scratch not supported" - (#3) "Error: SCFI: unsupported stack manipulation pattern" - (#4) "Error: untraceable control flow for func 'XXX'" In the newly added aarch64 testsuite, further tests for additional diagnostics have been added: - scfi-diag-1.s in this patch highlights an aarch64-specific diagnostic: (#5) "Warning: SCFI: ignored probable save/restore op with reg offset" Additionally, some testcases are added to showcase the (currently) unsupported patterns, e.g., scfi-unsupported-1.s mov x16, 4384 sub sp, sp, x16 gas/testsuite/: * gas/scfi/README: Update comment to include aarch64. * gas/scfi/aarch64/scfi-aarch64.exp: New file. * gas/scfi/aarch64/ginsn-arith-1.l: New test. * gas/scfi/aarch64/ginsn-arith-1.s: New test. * gas/scfi/aarch64/ginsn-cofi-1.l: New test. * gas/scfi/aarch64/ginsn-cofi-1.s: New test. * gas/scfi/aarch64/ginsn-ldst-1.l: New test. * gas/scfi/aarch64/ginsn-ldst-1.s: New test. * gas/scfi/aarch64/scfi-callee-saved-fp-1.d: New test. * gas/scfi/aarch64/scfi-callee-saved-fp-1.l: New test. * gas/scfi/aarch64/scfi-callee-saved-fp-1.s: New test. * gas/scfi/aarch64/scfi-callee-saved-fp-2.d: New test. * gas/scfi/aarch64/scfi-callee-saved-fp-2.l: New test. * gas/scfi/aarch64/scfi-callee-saved-fp-2.s: New test. * gas/scfi/aarch64/scfi-cb-1.d: New test. * gas/scfi/aarch64/scfi-cb-1.l: New test. * gas/scfi/aarch64/scfi-cb-1.s: New test. * gas/scfi/aarch64/scfi-cfg-1.d: New test. * gas/scfi/aarch64/scfi-cfg-1.l: New test. * gas/scfi/aarch64/scfi-cfg-1.s: New test. * gas/scfi/aarch64/scfi-cfg-2.d: New test. * gas/scfi/aarch64/scfi-cfg-2.l: New test. * gas/scfi/aarch64/scfi-cfg-2.s: New test. * gas/scfi/aarch64/scfi-cfg-3.d: New test. * gas/scfi/aarch64/scfi-cfg-3.l: New test. * gas/scfi/aarch64/scfi-cfg-3.s: New test. * gas/scfi/aarch64/scfi-cfg-4.l: New test. * gas/scfi/aarch64/scfi-cfg-4.s: New test. * gas/scfi/aarch64/scfi-cond-br-1.d: New test. * gas/scfi/aarch64/scfi-cond-br-1.l: New test. * gas/scfi/aarch64/scfi-cond-br-1.s: New test. * gas/scfi/aarch64/scfi-diag-1.l: New test. * gas/scfi/aarch64/scfi-diag-1.s: New test. * gas/scfi/aarch64/scfi-diag-2.l: New test. * gas/scfi/aarch64/scfi-diag-2.s: New test. * gas/scfi/aarch64/scfi-diag-3.l: New test. * gas/scfi/aarch64/scfi-diag-3.s: New test. * gas/scfi/aarch64/scfi-ldrp-1.d: New test. * gas/scfi/aarch64/scfi-ldrp-1.l: New test. * gas/scfi/aarch64/scfi-ldrp-1.s: New test. * gas/scfi/aarch64/scfi-ldrp-2.d: New test. * gas/scfi/aarch64/scfi-ldrp-2.l: New test. * gas/scfi/aarch64/scfi-ldrp-2.s: New test. * gas/scfi/aarch64/scfi-ldstnap-1.d: New test. * gas/scfi/aarch64/scfi-ldstnap-1.l: New test. * gas/scfi/aarch64/scfi-ldstnap-1.s: New test. * gas/scfi/aarch64/scfi-strp-1.d: New test. * gas/scfi/aarch64/scfi-strp-1.l: New test. * gas/scfi/aarch64/scfi-strp-1.s: New test. * gas/scfi/aarch64/scfi-strp-2.d: New test. * gas/scfi/aarch64/scfi-strp-2.l: New test. * gas/scfi/aarch64/scfi-strp-2.s: New test. * gas/scfi/aarch64/scfi-unsupported-1.l: New test. * gas/scfi/aarch64/scfi-unsupported-1.s: New test. * gas/scfi/aarch64/scfi-unsupported-2.l: New test. * gas/scfi/aarch64/scfi-unsupported-2.s: New test.

Since commit b1da98a ("gdb: remove use of alloca in new_macro_definition"), if cached_argv is empty, we call macro_bcache with a nullptr data. This ends up caught by UBSan deep down in the bcache code: $ ./gdb -nx -q --data-directory=data-directory /home/smarchi/build/binutils-gdb/gdb/testsuite/outputs/gdb.base/macscp/macscp -readnow Reading symbols from /home/smarchi/build/binutils-gdb/gdb/testsuite/outputs/gdb.base/macscp/macscp... Expanding full symbols from /home/smarchi/build/binutils-gdb/gdb/testsuite/outputs/gdb.base/macscp/macscp... /home/smarchi/src/binutils-gdb/gdb/bcache.c:195:12: runtime error: null pointer passed as argument 2, which is declared to never be null The backtrace: #1 0x00007ffff619a05d in __ubsan::__ubsan_handle_nonnull_arg_abort (Data=<optimized out>) at ../../../../src/libsanitizer/ubsan/ubsan_handlers.cpp:750 #2 0x000055556337fba2 in gdb::bcache::insert (this=0x62d0000c8458, addr=0x0, length=0, added=0x0) at /home/smarchi/src/binutils-gdb/gdb/bcache.c:195 #3 0x0000555564b49222 in gdb::bcache::insert<char const*, void> (this=0x62d0000c8458, addr=0x0, length=0, added=0x0) at /home/smarchi/src/binutils-gdb/gdb/bcache.h:158 #4 0x0000555564b481fa in macro_bcache<char const*> (t=0x62100007ae70, addr=0x0, len=0) at /home/smarchi/src/binutils-gdb/gdb/macrotab.c:117 #5 0x0000555564b42b4a in new_macro_definition (t=0x62100007ae70, kind=macro_function_like, special_kind=macro_ordinary, argv=std::__debug::vector of length 0, capacity 0, replacement=0x62a00003af3a "__builtin_va_arg_pack ()") at /home/smarchi/src/binutils-gdb/gdb/macrotab.c:573 XUANTIE-RV#6 0x0000555564b44674 in macro_define_internal (source=0x6210000ab9e0, line=469, name=0x7fffffffa710 "__va_arg_pack", kind=macro_function_like, special_kind=macro_ordinary, argv=std::__debug::vector of length 0, capacity 0, replacement=0x62a00003af3a "__builtin_va_arg_pack ()") at /home/smarchi/src/binutils-gdb/gdb/macrotab.c:777 #7 0x0000555564b44ae2 in macro_define_function (source=0x6210000ab9e0, line=469, name=0x7fffffffa710 "__va_arg_pack", argv=std::__debug::vector of length 0, capacity 0, replacement=0x62a00003af3a "__builtin_va_arg_pack ()") at /home/smarchi/src/binutils-gdb/gdb/macrotab.c:816 #8 0x0000555563f62fc8 in parse_macro_definition (file=0x6210000ab9e0, line=469, body=0x62a00003af2a "__va_arg_pack() __builtin_va_arg_pack ()") at /home/smarchi/src/binutils-gdb/gdb/dwarf2/macro.c:203 This can be reproduced by running gdb.base/macscp.exp. Avoid calling macro_bcache if the macro doesn't have any arguments. Change-Id: I33b5a7c3b3a93d5adba98983fcaae9c8522c383d

The commit: commit c6b4867 Date: Thu Mar 30 19:21:22 2023 +0100 gdb: parse pending breakpoint thread/task immediately Introduce a use bug where the value of a temporary variable was being used after it had gone out of scope. This was picked up by the address sanitizer and would result in this error: (gdb) maintenance selftest create_breakpoint_parse_arg_string Running selftest create_breakpoint_parse_arg_string. ================================================================= ==2265825==ERROR: AddressSanitizer: stack-use-after-scope on address 0x7fbb08046511 at pc 0x000001632230 bp 0x7fff7c2fb770 sp 0x7fff7c2fb768 READ of size 1 at 0x7fbb08046511 thread T0 #0 0x163222f in create_breakpoint_parse_arg_string(char const*, std::unique_ptr<char, gdb::xfree_deleter<char> >*, int*, int*, int*, std::unique_ptr<char, gdb::xfree_deleter<char> >*, bool*) ../../src/gdb/break-cond-parse.c:496 #1 0x1633026 in test ../../src/gdb/break-cond-parse.c:582 #2 0x163391b in create_breakpoint_parse_arg_string_tests ../../src/gdb/break-cond-parse.c:649 #3 0x12cfebc in void std::__invoke_impl<void, void (*&)()>(std::__invoke_other, void (*&)()) /usr/include/c++/13/bits/invoke.h:61 #4 0x12cc8ee in std::enable_if<is_invocable_r_v<void, void (*&)()>, void>::type std::__invoke_r<void, void (*&)()>(void (*&)()) /usr/include/c++/13/bits/invoke.h:111 #5 0x12c81e5 in std::_Function_handler<void (), void (*)()>::_M_invoke(std::_Any_data const&) /usr/include/c++/13/bits/std_function.h:290 XUANTIE-RV#6 0x18bb51d in std::function<void ()>::operator()() const /usr/include/c++/13/bits/std_function.h:591 #7 0x4193ef9 in selftests::run_tests(gdb::array_view<char const* const>, bool) ../../src/gdbsupport/selftest.cc:100 #8 0x21c2206 in maintenance_selftest ../../src/gdb/maint.c:1172 ... etc ... The problem was caused by three lines like this one: thread_info *thr = parse_thread_id (std::string (t.get_value ()).c_str (), &tmptok); After parsing the thread-id TMPTOK would be left pointing into the temporary string which had been created on this line. When on the next line we did this: gdb_assert (*tmptok == '\0'); The value of *TMPTOK is undefined. Fix this by creating the std::string earlier in the scope. Now the contents of the string will remain valid when we check *TMPTOK. The address sanitizer issue is now resolved.

The binary provided with bug 32165 [1] has 36139 ELF sections. GDB crashes on it with (note that my GDB is build with -D_GLIBCXX_DEBUG=1: $ ./gdb -nx -q --data-directory=data-directory ./vmlinux Reading symbols from ./vmlinux... (No debugging symbols found in ./vmlinux) (gdb) info func /usr/include/c++/14.2.1/debug/vector:508: In function: std::debug::vector<_Tp, _Allocator>::reference std::debug::vector<_Tp, _Allocator>::operator[](size_type) [with _Tp = long unsigned int; _Allocator = std::allocator<long unsigned int>; reference = long unsigned int&; size_type = long unsigned int] Error: attempt to subscript container with out-of-bounds index -29445, but container only holds 36110 elements. Objects involved in the operation: sequence "this" @ 0x514000007340 { type = std::debug::vector<unsigned long, std::allocator<unsigned long> >; } The crash occurs here: #3 0x00007ffff5e334c3 in __GI_abort () at abort.c:79 #4 0x00007ffff689afc4 in __gnu_debug::_Error_formatter::_M_error (this=<optimized out>) at /usr/src/debug/gcc/gcc/libstdc++-v3/src/c++11/debug.cc:1320 #5 0x0000555561119a16 in std::__debug::vector<unsigned long, std::allocator<unsigned long> >::operator[] (this=0x514000007340, __n=18446744073709522171) at /usr/include/c++/14.2.1/debug/vector:508 XUANTIE-RV#6 0x0000555562e288e8 in minimal_symbol::value_address (this=0x5190000bb698, objfile=0x514000007240) at /home/smarchi/src/binutils-gdb/gdb/symtab.c:517 #7 0x0000555562e5a131 in global_symbol_searcher::expand_symtabs (this=0x7ffff0f5c340, objfile=0x514000007240, preg=std::optional [no contained value]) at /home/smarchi/src/binutils-gdb/gdb/symtab.c:4983 #8 0x0000555562e5d2ed in global_symbol_searcher::search (this=0x7ffff0f5c340) at /home/smarchi/src/binutils-gdb/gdb/symtab.c:5189 #9 0x0000555562e5ffa4 in symtab_symbol_info (quiet=false, exclude_minsyms=false, regexp=0x0, kind=FUNCTION_DOMAIN, t_regexp=0x0, from_tty=1) at /home/smarchi/src/binutils-gdb/gdb/symtab.c:5361 #10 0x0000555562e6131b in info_functions_command (args=0x0, from_tty=1) at /home/smarchi/src/binutils-gdb/gdb/symtab.c:5525 That is, at this line of `minimal_symbol::value_address`, where `objfile->section_offsets` is an `std::vector`: return (CORE_ADDR (this->unrelocated_address ()) + objfile->section_offsets[this->section_index ()]); A section index of -29445 is suspicious. The minimal_symbol at play here is: (top-gdb) p m_name $1 = 0x521001de10af "_sinittext" So I restarted debugging, breaking on: (top-gdb) b general_symbol_info::set_section_index if $_streq("_sinittext", m_name) And I see that weird -29445 value: (top-gdb) frame #0 general_symbol_info::set_section_index (this=0x525000082390, idx=-29445) at /home/smarchi/src/binutils-gdb/gdb/symtab.h:611 611 { m_section = idx; } But going up one frame, the section index is 36091: (top-gdb) frame #1 0x0000555562426526 in minimal_symbol_reader::record_full (this=0x7ffff0ead560, name="_sinittext", copy_name=false, address=-2111475712, ms_type=mst_text, section=36091) at /home/smarchi/src/binutils-gdb/gdb/minsyms.c:1228 1228 msymbol->set_section_index (section); It seems like the problem is just that the type used for the section index (short) is not big enough. Change from short to int. If somebody insists, we could even go long long / int64_t, but I doubt it's necessary. With that fixed, I get: (gdb) info func All defined functions: Non-debugging symbols: 0xffffffff81000000 _stext 0xffffffff82257000 _sinittext 0xffffffff822b4ebb _einittext [1] https://sourceware.org/bugzilla/show_bug.cgi?id=32165 Change-Id: Icb1c3de9474ff5adef7e0bbbf5e0b67b279dee04 Reviewed-By: Tom de Vries <[email protected]> Reviewed-by: Keith Seitz <[email protected]>

When building gdb with gcc 12 and -fsanitize=threads while renabling background dwarf reading by setting dwarf_synchronous to false, I run into: ... (gdb) file amd64-watchpoint-downgrade Reading symbols from amd64-watchpoint-downgrade... (gdb) watch global_var ================== WARNING: ThreadSanitizer: data race (pid=20124) Read of size 8 at 0x7b80000500d8 by main thread: #0 cooked_index_entry::full_name(obstack*, bool) const cooked-index.c:220 #1 cooked_index::get_main_name(obstack*, language*) const cooked-index.c:735 #2 cooked_index_worker::wait(cooked_state, bool) cooked-index.c:559 #3 cooked_index::wait(cooked_state, bool) cooked-index.c:631 #4 cooked_index_functions::wait(objfile*, bool) cooked-index.h:729 #5 cooked_index_functions::compute_main_name(objfile*) cooked-index.h:806 XUANTIE-RV#6 objfile::compute_main_name() symfile-debug.c:461 #7 find_main_name symtab.c:6503 #8 main_language() symtab.c:6608 #9 set_initial_language_callback symfile.c:1634 #10 get_current_language() language.c:96 ... Previous write of size 8 at 0x7b80000500d8 by thread T1: #0 cooked_index_shard::finalize(parent_map_map const*) \ dwarf2/cooked-index.c:409 #1 operator() cooked-index.c:663 ... ... SUMMARY: ThreadSanitizer: data race cooked-index.c:220 in \ cooked_index_entry::full_name(obstack*, bool) const ================== Hardware watchpoint 1: global_var (gdb) PASS: gdb.arch/amd64-watchpoint-downgrade.exp: watch global_var ... This was also reported in PR31715. This is due do gcc PR110799 [1], generating wrong code with -fhoist-adjacent-loads, and causing a false positive for -fsanitize=threads. Work around the gcc PR by forcing -fno-hoist-adjacent-loads for gcc <= 13 and -fsanitize=threads. Tested in that same configuration on x86_64-linux. Remaining ThreadSanitizer problems are the ones reported in PR31626 (gdb.rust/dwindex.exp) and PR32247 (gdb.trace/basic-libipa.exp). PR gdb/31715 Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31715 Tested-By: Bernd Edlinger <[email protected]> Approved-By: Tom Tromey <[email protected]> [1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110799

When calling a function with double arguments, I get this asan error: ==7920==ERROR: AddressSanitizer: stack-buffer-overflow on address 0x0053131ece38 at pc 0x7ff79697a68f bp 0x0053131ec790 sp 0x0053131ebf40 READ of size 16 at 0x0053131ece38 thread T0 #0 0x7ff79697a68e in MemcmpInterceptorCommon(void*, int (*)(void const*, void const*, unsigned long long), void const*, void const*, unsigned long long) C:/gcc/src/gcc-14.2.0/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:814 #1 0x7ff79697aebd in memcmp C:/gcc/src/gcc-14.2.0/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:845 #2 0x7ff79697aebd in memcmp C:/gcc/src/gcc-14.2.0/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:840 #3 0x7ff7927e237f in regcache::raw_write(int, gdb::array_view<unsigned char const>) C:/gdb/src/gdb.git/gdb/regcache.c:874 #4 0x7ff7927e3c85 in regcache::cooked_write(int, gdb::array_view<unsigned char const>) C:/gdb/src/gdb.git/gdb/regcache.c:914 #5 0x7ff7927e5d89 in regcache::cooked_write(int, unsigned char const*) C:/gdb/src/gdb.git/gdb/regcache.c:933 XUANTIE-RV#6 0x7ff7911d5965 in amd64_windows_store_arg_in_reg C:/gdb/src/gdb.git/gdb/amd64-windows-tdep.c:216 Address 0x0053131ece38 is located in stack of thread T0 at offset 40 in frame #0 0x7ff7911d565f in amd64_windows_store_arg_in_reg C:/gdb/src/gdb.git/gdb/amd64-windows-tdep.c:208 This frame has 4 object(s): [32, 40) 'buf' (line 211) <== Memory access at offset 40 overflows this variable It's because the first 4 double arguments are passed via XMM registers, and they need a buffer of 16 bytes, even if we only use 8 bytes of them. Approved-By: Tom Tromey <[email protected]>

On Windows gcore is not implemented, and if you try it, you get an heap-use-after-free error: (gdb) gcore C:/gdb/build64/gdb-git-python3/gdb/testsuite/outputs/gdb.base/gcore-buffer-overflow/gcore-buffer-overflow.test warning: cannot close "================================================================= ==10108==ERROR: AddressSanitizer: heap-use-after-free on address 0x1259ea503110 at pc 0x7ff6806e3936 bp 0x0062e01ed990 sp 0x0062e01ed140 READ of size 111 at 0x1259ea503110 thread T0 #0 0x7ff6806e3935 in strlen C:/gcc/src/gcc-14.2.0/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:391 #1 0x7ff6807169c4 in __pformat_puts C:/gcc/src/mingw-w64-v12.0.0/mingw-w64-crt/stdio/mingw_pformat.c:558 #2 0x7ff6807186c1 in __mingw_pformat C:/gcc/src/mingw-w64-v12.0.0/mingw-w64-crt/stdio/mingw_pformat.c:2514 #3 0x7ff680713614 in __mingw_vsnprintf C:/gcc/src/mingw-w64-v12.0.0/mingw-w64-crt/stdio/mingw_vsnprintf.c:41 #4 0x7ff67f34419f in vsnprintf(char*, unsigned long long, char const*, char*) C:/msys64/mingw64/x86_64-w64-mingw32/include/stdio.h:484 #5 0x7ff67f34419f in string_vprintf[abi:cxx11](char const*, char*) C:/gdb/src/gdb.git/gdbsupport/common-utils.cc:106 XUANTIE-RV#6 0x7ff67b37b739 in cli_ui_out::do_message(ui_file_style const&, char const*, char*) C:/gdb/src/gdb.git/gdb/cli-out.c:227 #7 0x7ff67ce3d030 in ui_out::call_do_message(ui_file_style const&, char const*, ...) C:/gdb/src/gdb.git/gdb/ui-out.c:571 #8 0x7ff67ce4255a in ui_out::vmessage(ui_file_style const&, char const*, char*) C:/gdb/src/gdb.git/gdb/ui-out.c:740 #9 0x7ff67ce2c873 in ui_file::vprintf(char const*, char*) C:/gdb/src/gdb.git/gdb/ui-file.c:73 #10 0x7ff67ce7f83d in gdb_vprintf(ui_file*, char const*, char*) C:/gdb/src/gdb.git/gdb/utils.c:1881 #11 0x7ff67ce7f83d in vwarning(char const*, char*) C:/gdb/src/gdb.git/gdb/utils.c:181 #12 0x7ff67f3530eb in warning(char const*, ...) C:/gdb/src/gdb.git/gdbsupport/errors.cc:33 #13 0x7ff67baed27f in gdb_bfd_close_warning C:/gdb/src/gdb.git/gdb/gdb_bfd.c:437 #14 0x7ff67baed27f in gdb_bfd_close_or_warn C:/gdb/src/gdb.git/gdb/gdb_bfd.c:646 #15 0x7ff67baed27f in gdb_bfd_unref(bfd*) C:/gdb/src/gdb.git/gdb/gdb_bfd.c:739 #16 0x7ff68094b6f2 in gdb_bfd_ref_policy::decref(bfd*) C:/gdb/src/gdb.git/gdb/gdb_bfd.h:82 #17 0x7ff68094b6f2 in gdb::ref_ptr<bfd, gdb_bfd_ref_policy>::~ref_ptr() C:/gdb/src/gdb.git/gdbsupport/gdb_ref_ptr.h:91 #18 0x7ff67badf4d2 in gcore_command C:/gdb/src/gdb.git/gdb/gcore.c:176 0x1259ea503110 is located 16 bytes inside of 4064-byte region [0x1259ea503100,0x1259ea5040e0) freed by thread T0 here: #0 0x7ff6806b1687 in free C:/gcc/src/gcc-14.2.0/libsanitizer/asan/asan_malloc_win.cpp:90 #1 0x7ff67f2ae807 in objalloc_free C:/gdb/src/gdb.git/libiberty/objalloc.c:187 #2 0x7ff67d7f56e3 in _bfd_free_cached_info C:/gdb/src/gdb.git/bfd/opncls.c:247 #3 0x7ff67d7f2782 in _bfd_delete_bfd C:/gdb/src/gdb.git/bfd/opncls.c:180 #4 0x7ff67d7f5df9 in bfd_close_all_done C:/gdb/src/gdb.git/bfd/opncls.c:960 #5 0x7ff67d7f62ec in bfd_close C:/gdb/src/gdb.git/bfd/opncls.c:925 XUANTIE-RV#6 0x7ff67baecd27 in gdb_bfd_close_or_warn C:/gdb/src/gdb.git/gdb/gdb_bfd.c:643 #7 0x7ff67baecd27 in gdb_bfd_unref(bfd*) C:/gdb/src/gdb.git/gdb/gdb_bfd.c:739 #8 0x7ff68094b6f2 in gdb_bfd_ref_policy::decref(bfd*) C:/gdb/src/gdb.git/gdb/gdb_bfd.h:82 #9 0x7ff68094b6f2 in gdb::ref_ptr<bfd, gdb_bfd_ref_policy>::~ref_ptr() C:/gdb/src/gdb.git/gdbsupport/gdb_ref_ptr.h:91 #10 0x7ff67badf4d2 in gcore_command C:/gdb/src/gdb.git/gdb/gcore.c:176 It happens because gdb_bfd_close_or_warn uses a bfd-internal name for the failing-close warning, after the close is finished, and the name already freed: static int gdb_bfd_close_or_warn (struct bfd *abfd) { int ret; const char *name = bfd_get_filename (abfd); for (asection *sect : gdb_bfd_sections (abfd)) free_one_bfd_section (sect); ret = bfd_close (abfd); if (!ret) gdb_bfd_close_warning (name, bfd_errmsg (bfd_get_error ())); return ret; } Fixed by making a copy of the name for the warning. Approved-By: Andrew Burgess <[email protected]>

This commit adds support for a `gstack' command which Fedora has been carrying for many years. gstack is a natural counterpart to the gcore command. Whereas gcore dumps a core file, gstack prints stack traces of a running process. There are many improvements over Fedora's version of this script. The dependency on procfs is gone; gstack will run anywhere gdb runs. The only runtime dependencies are bash and awk. The script includes suggestions from gdb/32325 to include versioning and help. [If this approach to gdb/32325 is acceptable, I could propagate the solution to gcore/gdb-add-index.] I've rewritten the documentation, integrating it into the User Manual. The manpage is now output using this one source. Example run (on x86_64 Fedora 40) $ gstack --help Usage: gstack [-h|--help] [-v|--version] PID Print a stack trace of a running program -h, --help Print this message then exit. -v, --version Print version information then exit. $ gstack -v GNU gstack (GDB) 16.0.50.20241119-git $ gstack 12345678 Process 12345678 not found. $ gstack $(pidof emacs) Thread 6 (Thread 0x7fd5ec1c06c0 (LWP 2491423) "pool-spawner"): #0 0x00007fd6015ca3dd in syscall () at /lib64/libc.so.6 #1 0x00007fd60b31eccd in g_cond_wait () at /lib64/libglib-2.0.so.0 #2 0x00007fd60b28a61b in g_async_queue_pop_intern_unlocked () at /lib64/libglib-2.0.so.0 #3 0x00007fd60b2f1a03 in g_thread_pool_spawn_thread () at /lib64/libglib-2.0.so.0 #4 0x00007fd60b2f0813 in g_thread_proxy () at /lib64/libglib-2.0.so.0 #5 0x00007fd6015486d7 in start_thread () at /lib64/libc.so.6 XUANTIE-RV#6 0x00007fd6015cc60c in clone3 () at /lib64/libc.so.6 #7 0x0000000000000000 in ??? () Thread 5 (Thread 0x7fd5eb9bf6c0 (LWP 2491424) "gmain"): #0 0x00007fd6015be87d in poll () at /lib64/libc.so.6 #1 0x0000000000000001 in ??? () #2 0xffffffff00000001 in ??? () #3 0x0000000000000001 in ??? () #4 0x000000002104cfd0 in ??? () #5 0x00007fd5eb9be320 in ??? () XUANTIE-RV#6 0x00007fd60b321c34 in g_main_context_iterate_unlocked.isra () at /lib64/libglib-2.0.so.0 Thread 4 (Thread 0x7fd5eb1be6c0 (LWP 2491425) "gdbus"): #0 0x00007fd6015be87d in poll () at /lib64/libc.so.6 #1 0x0000000020f9b558 in ??? () #2 0xffffffff00000003 in ??? () #3 0x0000000000000003 in ??? () #4 0x00007fd5d8000b90 in ??? () #5 0x00007fd5eb1bd320 in ??? () XUANTIE-RV#6 0x00007fd60b321c34 in g_main_context_iterate_unlocked.isra () at /lib64/libglib-2.0.so.0 Thread 3 (Thread 0x7fd5ea9bd6c0 (LWP 2491426) "emacs"): #0 0x00007fd6015ca3dd in syscall () at /lib64/libc.so.6 #1 0x00007fd60b31eccd in g_cond_wait () at /lib64/libglib-2.0.so.0 #2 0x00007fd60b28a61b in g_async_queue_pop_intern_unlocked () at /lib64/libglib-2.0.so.0 #3 0x00007fd60b28a67c in g_async_queue_pop () at /lib64/libglib-2.0.so.0 #4 0x00007fd603f4d0d9 in fc_thread_func () at /lib64/libpangoft2-1.0.so.0 #5 0x00007fd60b2f0813 in g_thread_proxy () at /lib64/libglib-2.0.so.0 XUANTIE-RV#6 0x00007fd6015486d7 in start_thread () at /lib64/libc.so.6 #7 0x00007fd6015cc60c in clone3 () at /lib64/libc.so.6 #8 0x0000000000000000 in ??? () Thread 2 (Thread 0x7fd5e9e6d6c0 (LWP 2491427) "dconf worker"): #0 0x00007fd6015be87d in poll () at /lib64/libc.so.6 #1 0x0000000000000001 in ??? () #2 0xffffffff00000001 in ??? () #3 0x0000000000000001 in ??? () #4 0x00007fd5cc000b90 in ??? () #5 0x00007fd5e9e6c320 in ??? () XUANTIE-RV#6 0x00007fd60b321c34 in g_main_context_iterate_unlocked.isra () at /lib64/libglib-2.0.so.0 Thread 1 (Thread 0x7fd5fcc45280 (LWP 2491417) "emacs"): #0 0x00007fd6015c9197 in pselect () at /lib64/libc.so.6 #1 0x0000000000000000 in ??? () Since this is essentially a complete rewrite of the original script and documentation, I've chosen to only keep a 2024 copyright date. Reviewed-By: Eli Zaretskii <[email protected]> Approved-By: Tom Tromey <[email protected]>

…read call Commit 7fcdec0 ("GDB: Use gdb::array_view for buffers used in register reading and unwinding") introduces a regression in gdb.base/jit-reader.exp: $ ./gdb -q -nx --data-directory=data-directory testsuite/outputs/gdb.base/jit-reader/jit-reader -ex 'jit-reader-load /home/simark/build/binutils-gdb/gdb/testsuite/outputs/gdb.base/jit-reader/jit-reader.so' -ex r -batch This GDB supports auto-downloading debuginfo from the following URLs: <https://debuginfod.archlinux.org> Enable debuginfod for this session? (y or [n]) [answered N; input not from terminal] Debuginfod has been disabled. To make this setting permanent, add 'set debuginfod enabled off' to .gdbinit. [Thread debugging using libthread_db enabled] Using host libthread_db library "/usr/lib/../lib/libthread_db.so.1". Program received signal SIGTRAP, Trace/breakpoint trap. Recursive internal problem. The "Recusive internal problem" part is not good, but it's not the point of this patch. It still means we hit an internal error. The stack trace is: #0 internal_error_loc (file=0x55555ebefb20 "/home/simark/src/binutils-gdb/gdb/frame.c", line=1207, fmt=0x55555ebef500 "%s: Assertion `%s' failed.") at /home/simark/src/binutils-gdb/gdbsupport/errors.cc:53 #1 0x0000555561604d83 in frame_register_unwind (next_frame=..., regnum=16, optimizedp=0x7ffff12e5a20, unavailablep=0x7ffff12e5a30, lvalp=0x7ffff12e5a40, addrp=0x7ffff12e5a60, realnump=0x7ffff12e5a50, buffer=...) at /home/simark/src/binutils-gdb/gdb/frame.c:1207 #2 0x0000555561608334 in deprecated_frame_register_read (frame=..., regnum=16, myaddr=...) at /home/simark/src/binutils-gdb/gdb/frame.c:1496 #3 0x0000555561a74259 in jit_unwind_reg_get_impl (cb=0x7ffff1049ca0, regnum=16) at /home/simark/src/binutils-gdb/gdb/jit.c:988 #4 0x00007fffd26e634e in read_register (callbacks=0x7ffff1049ca0, dw_reg=16, value=0x7fffffffb4c8) at /home/simark/src/binutils-gdb/gdb/testsuite/gdb.base/jit-reader.c:100 #5 0x00007fffd26e645f in unwind_frame (self=0x50400000ac10, cbs=0x7ffff1049ca0) at /home/simark/src/binutils-gdb/gdb/testsuite/gdb.base/jit-reader.c:143 XUANTIE-RV#6 0x0000555561a74a12 in jit_frame_sniffer (self=0x55556374d040 <jit_frame_unwind>, this_frame=..., cache=0x5210002905f8) at /home/simark/src/binutils-gdb/gdb/jit.c:1042 #7 0x00005555615f499e in frame_unwind_try_unwinder (this_frame=..., this_cache=0x5210002905f8, unwinder=0x55556374d040 <jit_frame_unwind>) at /home/simark/src/binutils-gdb/gdb/frame-unwind.c:138 #8 0x00005555615f512c in frame_unwind_find_by_frame (this_frame=..., this_cache=0x5210002905f8) at /home/simark/src/binutils-gdb/gdb/frame-unwind.c:209 #9 0x00005555616178d0 in get_frame_type (frame=...) at /home/simark/src/binutils-gdb/gdb/frame.c:2996 #10 0x000055556282db03 in do_print_frame_info (uiout=0x511000027500, fp_opts=..., frame=..., print_level=0, print_what=SRC_AND_LOC, print_args=1, set_current_sal=1) at /home/simark/src/binutils-gdb/gdb/stack.c:1033 The problem is that function `jit_unwind_reg_get_impl` passes field `gdb_reg_value::value`, a gdb_byte array of 1 element (used as a flexible array member), as the array view parameter of `deprecated_frame_register_read`. This results in an array view of size 1. The assertion in `frame_register_unwind` that verifies the passed in buffer is larger enough to hold the unwound register value then fails. Fix this by explicitly creating an array view of the right size. Change-Id: Ie170da438ec9085863e7be8b455a067b531635dc Reviewed-by: Thiago Jung Bauermann <[email protected]>

Fix v0p7 extension missing.

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Fix v0p7 extension missing. #4

Fix v0p7 extension missing. #4

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pz9115 commented Mar 18, 2024

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Fix v0p7 extension missing. #4

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Fix v0p7 extension missing. #4

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pz9115 commented Mar 18, 2024

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