From 463ebcdca8feee7e92a2629fa3e0efbc6d28dc4a Mon Sep 17 00:00:00 2001 From: Takashi Yano Date: Mon, 3 Mar 2025 15:31:23 +0900 Subject: [PATCH] Cygwin: console: Redesign mode set strategy on close(). The required console mode for a non-cygwin process is different from that for a cygwin process. There are currently three modes: tty::cygwin, tty::native, and tty::restore. The latter two are for the non-cygwin processes. tty::restore is the mode for the non-cygwin processes that started the cygwin process, used to restore the previous behaviour. tty::native is the mode that reflects some terminfo flags. The issue below is caused because the console mode fails to be restored to the previous console mode used by cmd.exe. This patch redesigns the strategy to determine which mode should be set on console close() to fix all similar problems. Previously, the number of handle count is used to determine the appropriate console mode. However, the handle count seems uncertain for that purpose. In the new design, the relation ship between the master process and the process that is about to close the console is mainly used. This can provide more certain result than previous one. Addresses: https://github.com/microsoft/git/issues/730 Backported-from: 3312f2d21f (Cygwin: console: Redesign mode set strategy on close()., 2025-03-03) Fixes: 30d266947842 ("Cygwin: console: Fix clean up conditions in close()") Reported-by: Mike Marcelais, Johannes Schindelin Signed-off-by: Takashi Yano Signed-off-by: Johannes Schindelin --- winsup/cygwin/fhandler/console.cc | 47 ++++++++++++++++--------- winsup/cygwin/local_includes/fhandler.h | 1 + 2 files changed, 32 insertions(+), 16 deletions(-) diff --git a/winsup/cygwin/fhandler/console.cc b/winsup/cygwin/fhandler/console.cc index 2651e49a62..b095afa856 100644 --- a/winsup/cygwin/fhandler/console.cc +++ b/winsup/cygwin/fhandler/console.cc @@ -916,8 +916,7 @@ fhandler_console::cleanup_for_non_cygwin_app (handle_set_t *p) /* Cleaning-up console mode for non-cygwin app. */ /* conmode can be tty::restore when non-cygwin app is exec'ed from login shell. */ - tty::cons_mode conmode = - (con.owner == GetCurrentProcessId ()) ? tty::restore : tty::cygwin; + tty::cons_mode conmode = cons_mode_on_close (p); set_output_mode (conmode, ti, p); set_input_mode (conmode, ti, p); set_disable_master_thread (con.owner == GetCurrentProcessId ()); @@ -1976,22 +1975,13 @@ fhandler_console::close () acquire_output_mutex (mutex_timeout); - if (shared_console_info[unit] && !myself->cygstarted + if (shared_console_info[unit] && myself->ppid == 1 && (dev_t) myself->ctty == get_device ()) { - /* Restore console mode if this is the last closure. */ - OBJECT_BASIC_INFORMATION obi; - NTSTATUS status; - status = NtQueryObject (get_handle (), ObjectBasicInformation, - &obi, sizeof obi, NULL); - if (NT_SUCCESS (status) - && obi.HandleCount == (con.owner == GetCurrentProcessId () ? 2 : 3)) - { - /* Cleaning-up console mode for cygwin apps. */ - set_output_mode (tty::restore, &get_ttyp ()->ti, &handle_set); - set_input_mode (tty::restore, &get_ttyp ()->ti, &handle_set); - set_disable_master_thread (true, this); - } + tty::cons_mode conmode = cons_mode_on_close (&handle_set); + set_output_mode (conmode, &get_ttyp ()->ti, &handle_set); + set_input_mode (conmode, &get_ttyp ()->ti, &handle_set); + set_disable_master_thread (true, this); } if (shared_console_info[unit] && con.owner == GetCurrentProcessId ()) @@ -4690,3 +4680,28 @@ fhandler_console::fstat (struct stat *st) } return 0; } + +tty::cons_mode +fhandler_console::cons_mode_on_close (handle_set_t *p) +{ + const _minor_t unit = p->unit; + + if (myself->ppid != 1) /* Execed from normal cygwin process. */ + return tty::cygwin; + + if (!process_alive (con.owner)) /* The Master process already died. */ + return tty::restore; + if (con.owner == GetCurrentProcessId ()) /* Master process */ + return tty::restore; + + PROCESS_BASIC_INFORMATION pbi; + NTSTATUS status = + NtQueryInformationProcess (GetCurrentProcess (), ProcessBasicInformation, + &pbi, sizeof (pbi), NULL); + if (NT_SUCCESS (status) + && con.owner == (DWORD) pbi.InheritedFromUniqueProcessId) + /* The parent is the stub process. */ + return tty::restore; + + return tty::native; /* Otherwise */ +} diff --git a/winsup/cygwin/local_includes/fhandler.h b/winsup/cygwin/local_includes/fhandler.h index 88a6b7d47b..e19aca54eb 100644 --- a/winsup/cygwin/local_includes/fhandler.h +++ b/winsup/cygwin/local_includes/fhandler.h @@ -2391,6 +2391,7 @@ class fhandler_console: public fhandler_termios void setup_pcon_hand_over (); static void pcon_hand_over_proc (); + static tty::cons_mode cons_mode_on_close (handle_set_t *); friend tty_min * tty_list::get_cttyp (); };