From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 82052 invoked by alias); 6 Feb 2020 19:02:09 -0000 Mailing-List: contact cygwin-cvs-help@cygwin.com; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Post: List-Help: , Sender: cygwin-cvs-owner@cygwin.com Received: (qmail 82007 invoked by uid 9078); 6 Feb 2020 19:02:09 -0000 Date: Thu, 06 Feb 2020 19:02:00 -0000 Message-ID: <20200206190209.82005.qmail@sourceware.org> Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit From: Corinna Vinschen To: cygwin-cvs@sourceware.org Subject: [newlib-cygwin] Cygwin: pty: Use pinfo() rather than kill() with signal 0. X-Act-Checkin: newlib-cygwin X-Git-Author: Takashi Yano X-Git-Refname: refs/heads/master X-Git-Oldrev: ff24ce91938ac7ad1f3321b16118222f90ef98c3 X-Git-Newrev: 3a71c46380f2cad6a9cb9d182c117cb624214553 X-SW-Source: 2020-q1/txt/msg00054.txt https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=3a71c46380f2cad6a9cb9d182c117cb624214553 commit 3a71c46380f2cad6a9cb9d182c117cb624214553 Author: Takashi Yano Date: Thu Feb 6 19:48:17 2020 +0900 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(). Diff: --- 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 9270c83..82527ec 100644 --- a/winsup/cygwin/fhandler.h +++ b/winsup/cygwin/fhandler.h @@ -2211,7 +2211,7 @@ 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 1dd57b3..181bed5 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;