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charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 00CB11F390 X-Rspamd-Action: no action X-Spamd-Result: default: False [-4.51 / 50.00]; BAYES_HAM(-3.00)[100.00%]; NEURAL_HAM_LONG(-1.00)[-1.000]; R_DKIM_ALLOW(-0.20)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; NEURAL_HAM_SHORT(-0.20)[-1.000]; MIME_GOOD(-0.10)[text/plain]; MX_GOOD(-0.01)[]; FUZZY_BLOCKED(0.00)[rspamd.com]; RCVD_VIA_SMTP_AUTH(0.00)[]; ARC_NA(0.00)[]; MID_RHS_MATCH_FROM(0.00)[]; MIME_TRACE(0.00)[0:+]; RCPT_COUNT_TWO(0.00)[2]; RCVD_TLS_ALL(0.00)[]; DKIM_SIGNED(0.00)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; FROM_EQ_ENVFROM(0.00)[]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; RCVD_COUNT_TWO(0.00)[2]; TO_MATCH_ENVRCPT_ALL(0.00)[]; DBL_BLOCKED_OPENRESOLVER(0.00)[suse.de:dkim,suse.de:mid,suse.de:email]; DNSWL_BLOCKED(0.00)[2a07:de40:b281:106:10:150:64:167:received,2a07:de40:b281:104:10:150:64:97:from]; DKIM_TRACE(0.00)[suse.de:+] X-Rspamd-Server: rspamd1.dmz-prg2.suse.org X-BeenThere: gdb-patches@sourceware.org X-Mailman-Version: 2.1.30 Precedence: list List-Id: Gdb-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: gdb-patches-bounces~public-inbox=simark.ca@sourceware.org On 4/29/25 17:34, Tom Tromey wrote: >>>>>> "Tom" == Tom de Vries writes: > > Tom> - gdbpy_flush attempts to flush gdb_stdout, which is nullptr > Tom> - that causes a segfault > > When can this be nullptr? > That seems surprising to me. I managed to recognize the situation using: ... diff --git a/gdb/tui/tui-io.c b/gdb/tui/tui-io.c index 1b4cc82cce8..fa4186aea3b 100644 --- a/gdb/tui/tui-io.c +++ b/gdb/tui/tui-io.c @@ -869,6 +869,7 @@ tui_setup_io (int mode) /* Restore gdb output. */ gdb_stdout = tui_old_stdout; gdb_stderr = tui_old_stderr; + gdb_assert (gdb_stderr != nullptr); gdb_stdlog = tui_old_stdlog; gdb_stdtarg = gdb_stderr; current_uiout = tui_old_uiout; ... And the backtrace (in an unusual form because of recursion) is: ... #19000 0x000000000041a3b2 in main (argc=14, argv=0x7ffc5c28c168) at /data/vries/gdb/src/gdb/gdb.c:38 38 return gdb_main (&args); (gdb) down #18999 0x0000000000b68937 in gdb_main (args=0x7ffc5c28c030) at /data/vries/gdb/src/gdb/main.c:1363 1363 captured_main (args); (gdb) #18998 0x0000000000b6888e in captured_main (data=0x7ffc5c28c030) at /data/vries/gdb/src/gdb/main.c:1344 1344 captured_command_loop (); (gdb) #18997 0x0000000000b66dad in captured_command_loop () at /data/vries/gdb/src/gdb/main.c:466 466 start_event_loop (); (gdb) #18996 0x0000000000b66c21 in start_event_loop () at /data/vries/gdb/src/gdb/main.c:402 402 result = gdb_do_one_event (); (gdb) #18995 0x0000000001985e31 in gdb_do_one_event (mstimeout=-1) at /data/vries/gdb/src/gdbsupport/event-loop.cc:263 263 return gdb_wait_for_event (1); (gdb) #18994 0x0000000001986f70 in gdb_wait_for_event (block=1) at /data/vries/gdb/src/gdbsupport/event-loop.cc:672 672 handle_file_event (file_ptr, mask); (gdb) #18993 0x0000000001986995 in handle_file_event (file_ptr=0x3b26aff0, ready_mask=25) at /data/vries/gdb/src/gdbsupport/event-loop.cc:551 551 file_ptr->proc (file_ptr->error, file_ptr->client_data); (gdb) #18992 0x00000000010563ad in stdin_event_handler (error=1, client_data=0x3aec7120) at /data/vries/gdb/src/gdb/ui.c:128 128 quit_command ((char *) 0, 0); (gdb) #18991 0x00000000006b2e63 in quit_command (args=0x0, from_tty=0) at /data/vries/gdb/src/gdb/cli/cli-cmds.c:483 483 quit_force (args ? &exit_code : NULL, from_tty); (gdb) #18990 0x0000000000fd94dc in quit_force (exit_arg=0x0, from_tty=0) at /data/vries/gdb/src/gdb/top.c:1750 1750 undo_terminal_modifications_before_exit (); (gdb) #18989 0x0000000000fd942f in undo_terminal_modifications_before_exit () at /data/vries/gdb/src/gdb/top.c:1718 1718 tui_disable (); (gdb) #18988 0x000000000103fa11 in tui_disable () at /data/vries/gdb/src/gdb/tui/tui.c:562 562 tui_setup_io (0); (gdb) #18987 0x00000000010129d4 in tui_setup_io (mode=0) at /data/vries/gdb/src/gdb/tui/tui-io.c:872 872 gdb_assert (gdb_stderr != nullptr); (gdb) ... Thanks, - Tom