From d6485353a1195d07027c646591d87ad2737a9f68 Mon Sep 17 00:00:00 2001 From: Takashi Yano Date: Thu, 6 Feb 2020 19:48:17 +0900 Subject: [PATCH] Cygwin: pty: Use pinfo() rather than kill() with signal 0. - PTY code has a problem that tcsh is terminated if the following command is executed. true; chcp & This seems to be caused by invalid pointer access which occurs when the process exits during the kill() code is execuetd. This patch avoids the issue by not using kill(). --- winsup/cygwin/fhandler.h | 2 +- winsup/cygwin/fhandler_tty.cc | 10 +++++----- 2 files changed, 6 insertions(+), 6 deletions(-) diff --git a/winsup/cygwin/fhandler.h b/winsup/cygwin/fhandler.h index 27e9c1955..bed698f86 100644 --- a/winsup/cygwin/fhandler.h +++ b/winsup/cygwin/fhandler.h @@ -2217,7 +2217,7 @@ class fhandler_pty_slave: public fhandler_pty_common { if (!mask && get_ttyp ()->pcon_pid && get_ttyp ()->pcon_pid != myself->pid && - kill (get_ttyp ()->pcon_pid, 0) == 0) + !!pinfo (get_ttyp ()->pcon_pid)) return; get_ttyp ()->mask_switch_to_pcon_in = mask; } diff --git a/winsup/cygwin/fhandler_tty.cc b/winsup/cygwin/fhandler_tty.cc index 1dd57b369..181bed5a9 100644 --- a/winsup/cygwin/fhandler_tty.cc +++ b/winsup/cygwin/fhandler_tty.cc @@ -1103,7 +1103,7 @@ fhandler_pty_slave::set_switch_to_pcon (int fd_set) skip_console_setting: restore_reattach_pcon (); if (get_ttyp ()->pcon_pid == 0 || - kill (get_ttyp ()->pcon_pid, 0) != 0) + !pinfo (get_ttyp ()->pcon_pid)) get_ttyp ()->pcon_pid = myself->pid; get_ttyp ()->switch_to_pcon_in = true; } @@ -1111,7 +1111,7 @@ skip_console_setting: { wait_pcon_fwd (); if (get_ttyp ()->pcon_pid == 0 || - kill (get_ttyp ()->pcon_pid, 0) != 0) + !pinfo (get_ttyp ()->pcon_pid)) get_ttyp ()->pcon_pid = myself->pid; get_ttyp ()->switch_to_pcon_out = true; } @@ -1124,7 +1124,7 @@ fhandler_pty_slave::reset_switch_to_pcon (void) this->set_switch_to_pcon (fd); if (get_ttyp ()->pcon_pid && get_ttyp ()->pcon_pid != myself->pid && - kill (get_ttyp ()->pcon_pid, 0) == 0) + !!pinfo (get_ttyp ()->pcon_pid)) /* There is a process which is grabbing pseudo console. */ return; if (isHybrid) @@ -2728,7 +2728,7 @@ fhandler_pty_slave::fixup_after_attach (bool native_maybe, int fd_set) ENABLE_PROCESSED_INPUT | ENABLE_LINE_INPUT | ENABLE_ECHO_INPUT; SetConsoleMode (get_handle (), mode); if (get_ttyp ()->pcon_pid == 0 || - kill (get_ttyp ()->pcon_pid, 0) != 0) + !pinfo (get_ttyp ()->pcon_pid)) get_ttyp ()->pcon_pid = myself->pid; get_ttyp ()->switch_to_pcon_in = true; } @@ -2739,7 +2739,7 @@ fhandler_pty_slave::fixup_after_attach (bool native_maybe, int fd_set) if (!get_ttyp ()->switch_to_pcon_out) wait_pcon_fwd (); if (get_ttyp ()->pcon_pid == 0 || - kill (get_ttyp ()->pcon_pid, 0) != 0) + !pinfo (get_ttyp ()->pcon_pid)) get_ttyp ()->pcon_pid = myself->pid; get_ttyp ()->switch_to_pcon_out = true;