Mercurial > vim
view src/pty.c @ 34394:a400c8f9506f v9.1.0123
patch 9.1.0123: MS-Windows: system() may deadlock
Commit: https://github.com/vim/vim/commit/52ecc76c7fa1865603f27bc838efaeaa03cad77c
Author: GuyBrush <miguel.barro@live.com>
Date: Wed Feb 21 20:16:38 2024 +0100
patch 9.1.0123: MS-Windows: system() may deadlock
Problem: MS-Windows: system() may deadlock when calling binaries that
expect stdin
Solution: Ignore the SHELL_EXPAND flag
(GuyBrush)
This happens on binaries that expect stdin. For example:
:echo system("xxd")
will cause a deadlock.
SHELL_EXPAND is a flag devoted to support the linux implementation of
the backtick-expansion mechanism.
On linux backtic-expansion relies in the function mch_expand_wildchars()
(os_unix.c) that delegates on each specific shell (bash, sh, csh, zsh)
the expansion. Basically it composes a shell command that does the
expansion and redirects the output to a file and call_shell() it. On
windows backtick-expansion is performed by Vim itself.
On linux SHELL_EXPAND modifies how mch_call_shell_fork() (os_unix.c)
works. This function:
- relies on posix fork() to spawn a child process to execute a
external command.
- Child and parent process communicate using pipes (or pseudoterminal
if available).
User input (type ahead content) is processed in a loop only if
!(SHELL_EXPAND || SHELL_COOKED).
Though signals are used to detect Ctrl-C in all cases (the input
loop is not necessary to interrupt the function).
In the backtick-expansion the external command is the shell command
that provides the expansion. For the child redirection:
- SHELL_EXPAND replaces stdin, stdout & stderr to /dev/null. This is
why the shell command composed includes redirection (otherwise
output would be lost).
- !SHELL_EXPAND replaces stdin, stdout & stderr with the parent
created pipes (or pseudoterminal).
Note that the use of SIGINT signal prevents mch_call_shell_fork()
from hanging vim.
On Windows mch_system_piped() (os_win32.c) (which is only used when the
GUI is running) mimics mch_call_shell_fork() (os_unix.c).
Win32 lacks fork() and relies on CreateProcessW() and only has pipe
support (not pseudoterminal) which makes the implementation much
different.
But, the key idea is that windows lacks signals, the OS provides support
for console apps but gvim is not one. The only way of detecting a Ctrl-C
is actually processing user input (type ahead content). By ignoring the
user input under SHELL_EXPAND the function can hang gvim.
Ignoring SHELL_EXPAND flag has no consequence in Windows because as
mentioned above it is only meaningful in linux.
closes: #13988
Signed-off-by: GuyBrush <miguel.barro@live.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
author | Christian Brabandt <cb@256bit.org> |
---|---|
date | Wed, 21 Feb 2024 20:30:02 +0100 |
parents | 7c30841c60a0 |
children |
line wrap: on
line source
/* vi:set ts=8 sts=4 sw=4 noet: * * VIM - Vi IMproved by Bram Moolenaar * * Do ":help uganda" in Vim to read copying and usage conditions. * Do ":help credits" in Vim to see a list of people who contributed. * See README.txt for an overview of the Vim source code. */ /* * The stuff in this file mostly comes from the "screen" program. * Included with permission from Juergen Weigert. * Copied from "pty.c". "putenv.c" was used for putenv() in misc2.c. * * It has been modified to work better with Vim. * The parts that are not used in Vim have been deleted. * See the "screen" sources for the complete stuff. * * This specific version is distributed under the Vim license (attribution by * Juergen Weigert), the GPL applies to the original version, see the * copyright notice below. */ // Copyright (c) 1993 // Juergen Weigert (jnweiger@immd4.informatik.uni-erlangen.de) // Michael Schroeder (mlschroe@immd4.informatik.uni-erlangen.de) // Copyright (c) 1987 Oliver Laumann // // This program is free software; you can redistribute it and/or modify // it under the terms of the GNU General Public License as published by // the Free Software Foundation; either version 2, or (at your option) // any later version. // // This program is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the // GNU General Public License for more details. // // You should have received a copy of the GNU General Public License // along with this program (see the file COPYING); if not, write to the // Free Software Foundation, Inc., // 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA #include "vim.h" #if defined(FEAT_GUI) || defined(FEAT_JOB_CHANNEL) #include <signal.h> #ifdef HAVE_SYS_IOCTL_H # include <sys/ioctl.h> #endif #if HAVE_STROPTS_H # include <sys/types.h> # ifdef sinix # define buf_T __system_buf_t__ # endif # include <stropts.h> # ifdef sinix # undef buf_T # endif # ifdef SUN_SYSTEM # include <sys/conf.h> # if defined(HAVE_SYS_PTMS_H) && defined(HAVE_SVR4_PTYS) # include <sys/ptms.h> # endif # endif #endif #ifdef HAVE_UNISTD_H # include <unistd.h> #endif #if HAVE_TERMIO_H # include <termio.h> #else # ifdef HAVE_TERMIOS_H # include <termios.h> # endif #endif #if HAVE_SYS_STREAM_H # include <sys/stream.h> #endif #if HAVE_SYS_PTEM_H # include <sys/ptem.h> #endif #if !defined(SUN_SYSTEM) && !defined(VMS) # include <sys/ioctl.h> #endif #if defined(SUN_SYSTEM) && defined(LOCKPTY) && !defined(TIOCEXCL) # include <sys/ttold.h> #endif #ifdef ISC # include <sys/tty.h> # include <sys/sioctl.h> # include <sys/pty.h> #endif #ifdef sgi # include <sys/sysmacros.h> #endif #if defined(_INCLUDE_HPUX_SOURCE) && !defined(hpux) # define hpux #endif /* * if no PTYRANGE[01] is in the config file, we pick a default */ #ifndef PTYRANGE0 # define PTYRANGE0 "qprs" #endif #ifndef PTYRANGE1 # define PTYRANGE1 "0123456789abcdef" #endif // SVR4 pseudo ttys don't seem to work with SCO-5 #ifdef M_UNIX # undef HAVE_SVR4_PTYS #endif /* * Open all ptys with O_NOCTTY, just to be on the safe side. */ #ifndef O_NOCTTY # define O_NOCTTY 0 #endif #if defined(HAVE_SVR4_PTYS) || defined(HAVE_POSIX_OPENPT) // These should be in stdlib.h, but it depends on _XOPEN_SOURCE. char *ptsname(int); int unlockpt(int); int grantpt(int); int posix_openpt(int flags); #endif static void initmaster(int f UNUSED) { #ifndef VMS # ifdef POSIX tcflush(f, TCIOFLUSH); # else # ifdef TIOCFLUSH (void)ioctl(f, TIOCFLUSH, (char *) 0); # endif # endif # ifdef LOCKPTY (void)ioctl(f, TIOCEXCL, (char *) 0); # endif #endif } /* * This causes a hang on some systems, but is required for a properly working * pty on others. Needs to be tuned... */ int setup_slavepty(int fd) { if (fd < 0) return 0; #if defined(I_PUSH) && defined(HAVE_SVR4_PTYS) && !defined(sgi) \ && !defined(linux) && !defined(__osf__) && !defined(M_UNIX) # if defined(HAVE_SYS_PTEM_H) || defined(hpux) if (ioctl(fd, I_PUSH, "ptem") != 0) return -1; # endif if (ioctl(fd, I_PUSH, "ldterm") != 0) return -1; # ifdef SUN_SYSTEM if (ioctl(fd, I_PUSH, "ttcompat") != 0) return -1; # endif #endif return 0; } #if defined(HAVE_POSIX_OPENPT) && !defined(PTY_DONE) #define PTY_DONE int mch_openpty(char **ttyn) { int f; char *m; sighandler_T sigcld; static char TtyName[32]; // used for opening a new pty-pair if ((f = posix_openpt(O_RDWR | O_NOCTTY | O_EXTRA)) == -1) return -1; // SIGCHLD set to SIG_DFL for grantpt() because it fork()s and // exec()s pt_chmod sigcld = mch_signal(SIGCHLD, SIG_DFL); if ((m = ptsname(f)) == NULL || grantpt(f) || unlockpt(f)) { mch_signal(SIGCHLD, sigcld); close(f); return -1; } mch_signal(SIGCHLD, sigcld); vim_strncpy((char_u *)TtyName, (char_u *)m, sizeof(TtyName) - 1); initmaster(f); *ttyn = TtyName; return f; } #endif #if defined(OSX) && !defined(PTY_DONE) #define PTY_DONE int mch_openpty(char **ttyn) { int f; static char TtyName[32]; if ((f = open_controlling_pty(TtyName)) < 0) return -1; initmaster(f); *ttyn = TtyName; return f; } #endif #if (defined(sequent) || defined(_SEQUENT_)) && defined(HAVE_GETPSEUDOTTY) \ && !defined(PTY_DONE) #define PTY_DONE int mch_openpty(char **ttyn) { char *m, *s; int f; // used for opening a new pty-pair: static char PtyName[32]; static char TtyName[32]; if ((f = getpseudotty(&s, &m)) < 0) return -1; #ifdef _SEQUENT_ fvhangup(s); #endif vim_strncpy((char_u *)PtyName, (char_u *)m, sizeof(PtyName) - 1); vim_strncpy((char_u *)TtyName, (char_u *)s, sizeof(TtyName) - 1); initmaster(f); *ttyn = TtyName; return f; } #endif #if defined(MIPS) && defined(HAVE_DEV_PTC) && !defined(PTY_DONE) #define PTY_DONE int mch_openpty(char **ttyn) { int f; stat_T buf; // used for opening a new pty-pair: static char TtyName[32]; if ((f = open("/dev/ptc", O_RDWR | O_NOCTTY | O_NONBLOCK | O_EXTRA, 0)) < 0) return -1; if (mch_fstat(f, &buf) < 0) { close(f); return -1; } sprintf(TtyName, "/dev/ttyq%d", minor(buf.st_rdev)); initmaster(f); *ttyn = TtyName; return f; } #endif #if defined(HAVE_SVR4_PTYS) && !defined(PTY_DONE) && !defined(hpux) \ && !(defined(MACOS_X) && !defined(MAC_OS_X_VERSION_10_6)) // NOTE: Even though HPUX can have /dev/ptmx, the code below doesn't work! // Same for Mac OS X Leopard (10.5). #define PTY_DONE int mch_openpty(char **ttyn) { int f; char *m; sighandler_T sigcld; // used for opening a new pty-pair: static char TtyName[32]; if ((f = open("/dev/ptmx", O_RDWR | O_NOCTTY | O_EXTRA, 0)) == -1) return -1; /* * SIGCHLD set to SIG_DFL for grantpt() because it fork()s and * exec()s pt_chmod */ sigcld = mch_signal(SIGCHLD, SIG_DFL); if ((m = ptsname(f)) == NULL || grantpt(f) || unlockpt(f)) { mch_signal(SIGCHLD, sigcld); close(f); return -1; } mch_signal(SIGCHLD, sigcld); vim_strncpy((char_u *)TtyName, (char_u *)m, sizeof(TtyName) - 1); initmaster(f); *ttyn = TtyName; return f; } #endif #if defined(_AIX) && defined(HAVE_DEV_PTC) && !defined(PTY_DONE) #define PTY_DONE #ifdef _IBMR2 static int aixhack = -1; #endif int mch_openpty(char **ttyn) { int f; // used for opening a new pty-pair: static char TtyName[32]; // a dumb looking loop replaced by mycrofts code: if ((f = open("/dev/ptc", O_RDWR | O_NOCTTY | O_EXTRA)) < 0) return -1; vim_strncpy((char_u *)TtyName, (char_u *)ttyname(f), sizeof(TtyName) - 1); if (geteuid() != ROOT_UID && mch_access(TtyName, R_OK | W_OK)) { close(f); return -1; } initmaster(f); # ifdef _IBMR2 if (aixhack >= 0) close(aixhack); if ((aixhack = open(TtyName, O_RDWR | O_NOCTTY | O_EXTRA, 0)) < 0) { close(f); return -1; } # endif *ttyn = TtyName; return f; } #endif #ifndef PTY_DONE # ifdef hpux static char PtyProto[] = "/dev/ptym/ptyXY"; static char TtyProto[] = "/dev/pty/ttyXY"; # else # ifdef __HAIKU__ static char PtyProto[] = "/dev/pt/XY"; static char TtyProto[] = "/dev/tt/XY"; # else static char PtyProto[] = "/dev/ptyXY"; static char TtyProto[] = "/dev/ttyXY"; # endif # endif int mch_openpty(char **ttyn) { char *p, *q, *l, *d; int f; // used for opening a new pty-pair: static char PtyName[32]; static char TtyName[32]; strcpy(PtyName, PtyProto); strcpy(TtyName, TtyProto); for (p = PtyName; *p != 'X'; p++) ; for (q = TtyName; *q != 'X'; q++) ; for (l = PTYRANGE0; (*p = *l) != '\0'; l++) { for (d = PTYRANGE1; (p[1] = *d) != '\0'; d++) { if ((f = open(PtyName, O_RDWR | O_NOCTTY | O_EXTRA, 0)) == -1) continue; q[0] = *l; q[1] = *d; if (geteuid() != ROOT_UID && mch_access(TtyName, R_OK | W_OK)) { close(f); continue; } #if defined(SUN_SYSTEM) && defined(TIOCGPGRP) && !defined(SUNOS3) // Hack to ensure that the slave side of the pty is // unused. May not work in anything other than SunOS4.1 { int pgrp; // tcgetpgrp does not work (uses TIOCGETPGRP)! if (ioctl(f, TIOCGPGRP, (char *)&pgrp) != -1 || errno != EIO) { close(f); continue; } } #endif initmaster(f); *ttyn = TtyName; return f; } } return -1; } #endif /* * Call isatty(fd), except for SunOS where it's done differently. */ int mch_isatty(int fd) { # if defined(I_STR) && defined(HAVE_SYS_PTMS_H) && defined(HAVE_SVR4_PTYS) \ && defined(SUN_SYSTEM) // On SunOS, isatty() for /dev/ptmx returns false or sometimes can hang up // in the inner ioctl(), and therefore first determine whether "fd" is a // master device. struct strioctl istr; istr.ic_cmd = ISPTM; istr.ic_timout = 0; istr.ic_dp = NULL; istr.ic_len = 0; if (ioctl(fd, I_STR, &istr) == 0) // Trick: return 2 in order to advice the caller that "fd" is a master // device. cf. src/os_unix.c:get_tty_fd() return 2; # endif return isatty(fd); } #endif // FEAT_GUI || FEAT_JOB_CHANNEL