Mercurial > vim
view src/os_win32.h @ 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 | 6733c5359e8a |
children |
line wrap: on
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/* 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. */ /* * Win32 (Windows NT and Windows 95) machine-dependent things. */ #include "os_dos.h" // common MS-DOS and Win32 stuff // cproto fails on missing include files #ifndef PROTO # include <direct.h> // for _mkdir() #endif #define BINARY_FILE_IO #define USE_EXE_NAME // use argv[0] for $VIM #define USE_TERM_CONSOLE #ifndef HAVE_STRING_H # define HAVE_STRING_H #endif #ifndef HAVE_MATH_H # define HAVE_MATH_H #endif #define HAVE_STRCSPN #ifndef __GNUC__ #define HAVE_STRICMP #define HAVE_STRNICMP #endif #ifndef HAVE_STRFTIME # define HAVE_STRFTIME // guessed #endif #define HAVE_MEMSET #ifndef HAVE_LOCALE_H # define HAVE_LOCALE_H 1 #endif #ifndef HAVE_FCNTL_H # define HAVE_FCNTL_H #endif #define HAVE_QSORT #define HAVE_ST_MODE // have stat.st_mode #define FEAT_SHORTCUT // resolve shortcuts // Access Control List (actually security info). #define HAVE_ACL #define USE_FNAME_CASE // adjust case of file names #if !defined(FEAT_CLIPBOARD) # define FEAT_CLIPBOARD // include clipboard support #endif #if defined(__DATE__) && defined(__TIME__) # define HAVE_DATE_TIME #endif #ifndef FEAT_GUI_MSWIN // GUI works different # define BREAKCHECK_SKIP 1 // call mch_breakcheck() each time, it's fast #endif #define HAVE_TOTAL_MEM #define HAVE_PUTENV // at least Bcc 5.2 and MSC have it #if defined(FEAT_GUI_MSWIN) && !defined(VIMDLL) # define NO_CONSOLE // don't include console-only code #endif // toupper() is not really broken, but it's very slow. Probably because of // using Unicode characters on Windows NT #define BROKEN_TOUPPER #define FNAME_ILLEGAL "\"*?><|" // illegal characters in a file name #include <signal.h> #include <stdlib.h> #include <time.h> #include <sys/types.h> #ifndef STRICT # define STRICT #endif #ifndef COBJMACROS # define COBJMACROS // For OLE: Enable "friendlier" access to objects #endif #ifndef PROTO // Must include winsock2.h before windows.h since it conflicts with winsock.h // (included in windows.h). # include <winsock2.h> # include <ws2tcpip.h> # include <windows.h> // Weird: rpcndr.h defines "small" to "char", which causes trouble #undef small # ifndef SM_CXPADDEDBORDER # define SM_CXPADDEDBORDER 92 # endif #endif typedef void (*sighandler_T)(int, int); /* * Win32 has plenty of memory, use large buffers */ #define CMDBUFFSIZE 1024 // size of the command processing buffer // _MAX_PATH is only 260 (stdlib.h), but we want more for the 'path' option, // thus use a larger number. #define MAXPATHL 1024 #ifndef BASENAMELEN # define BASENAMELEN (_MAX_PATH - 5) // length of base of file name #endif #define TEMPNAMELEN _MAX_PATH // length of temp file name path #ifndef DFLT_MAXMEM # define DFLT_MAXMEM (2*1024) // use up to 2 Mbyte for a buffer #endif #ifndef DFLT_MAXMEMTOT # define DFLT_MAXMEMTOT (5*1024) // use up to 5 Mbyte for Vim #endif /* * Reparse Point */ #ifndef FILE_ATTRIBUTE_REPARSE_POINT # define FILE_ATTRIBUTE_REPARSE_POINT 0x00000400 #endif #ifndef IO_REPARSE_TAG_MOUNT_POINT # define IO_REPARSE_TAG_MOUNT_POINT 0xA0000003 #endif #ifndef IO_REPARSE_TAG_SYMLINK # define IO_REPARSE_TAG_SYMLINK 0xA000000C #endif #ifndef IO_REPARSE_TAG_APPEXECLINK # define IO_REPARSE_TAG_APPEXECLINK 0x8000001B #endif /* * Definition of the reparse point buffer. * This is usually defined in the DDK, copy the definition here to avoid * adding it as a dependence only for a single structure. */ typedef struct _REPARSE_DATA_BUFFER { ULONG ReparseTag; USHORT ReparseDataLength; USHORT Reserved; union { struct { USHORT SubstituteNameOffset; USHORT SubstituteNameLength; USHORT PrintNameOffset; USHORT PrintNameLength; ULONG Flags; WCHAR PathBuffer[1]; } SymbolicLinkReparseBuffer; struct { USHORT SubstituteNameOffset; USHORT SubstituteNameLength; USHORT PrintNameOffset; USHORT PrintNameLength; WCHAR PathBuffer[1]; } MountPointReparseBuffer; struct { UCHAR DataBuffer[1]; } GenericReparseBuffer; struct { ULONG StringCount; WCHAR StringList[1]; } AppExecLinkReparseBuffer; } DUMMYUNIONNAME; } REPARSE_DATA_BUFFER, *PREPARSE_DATA_BUFFER; #ifdef _MSC_VER // Support for __try / __except. All versions of MSVC are // expected to have this. Any other compilers that support it? # define HAVE_TRY_EXCEPT 1 # include <malloc.h> // for _resetstkoflw() #endif /* * Some simple debugging macros that look and behave a lot like their * namesakes in MFC. */ #ifdef _DEBUG # include <crtdbg.h> # define ASSERT(f) _ASSERT(f) # define TRACE Trace # define TRACE0(sz) Trace(_T("%s"), _T(sz)) # define TRACE1(sz, p1) Trace(_T(sz), p1) # define TRACE2(sz, p1, p2) Trace(_T(sz), p1, p2) # define TRACE3(sz, p1, p2, p3) Trace(_T(sz), p1, p2, p3) # define TRACE4(sz, p1, p2, p3, p4) Trace(_T(sz), p1, p2, p3, p4) // In debug version, writes trace messages to debug stream void __cdecl Trace(char *pszFormat, ...); #else // !_DEBUG // These macros should all compile away to nothing # define ASSERT(f) ((void)0) # define TRACE 1 ? (void)0 : (void)printf # define TRACE0(sz) # define TRACE1(sz, p1) # define TRACE2(sz, p1, p2) # define TRACE3(sz, p1, p2, p3) # define TRACE4(sz, p1, p2, p3, p4) #endif // !_DEBUG #define ASSERT_POINTER(p, type) \ ASSERT(((p) != NULL) && IsValidAddress((p), sizeof(type), FALSE)) #define ASSERT_NULL_OR_POINTER(p, type) \ ASSERT(((p) == NULL) || IsValidAddress((p), sizeof(type), FALSE)) #ifndef HAVE_SETENV # define HAVE_SETENV #endif #define mch_getenv(x) (char_u *)getenv((char *)(x)) #define vim_mkdir(x, y) mch_mkdir(x)