Following Linux, allow the pathname argument to be an empty string if
the AT_EMPTY_PATH flag is specified. In this case the dirfd argument
can refer to any type of file, not just a directory, and the call
operates on that file. In particular, dirfd can refer to a symlink
that was opened with O_PATH | O_NOFOLLOW.
Following Linux, allow the pathname argument to be an empty string,
provided the dirfd argument refers to a symlink opened with
O_PATH | O_NOFOLLOW. The readlinkat call then operates on that
symlink.
Commit 283cb372, "Cygwin: normalize_win32_path: improve error
checking", required a prefix '\\?\' or '\??\' in the source path to be
followed by 'UNC\' or 'X:\', where X is a drive letter. That was too
restrictive, since it disallowed the paths '\\?\X: and '\??\X:'. This
caused problems when a user tried to use the root of a drive as the
Cygwin installation root, as reported here:
https://cygwin.com/ml/cygwin/2020-01/msg00111.html
Modify the requirement so that '\??\X:' and '\\?\X:' are now allowed
as source paths, without a trailing backslash.
- In octave gui, sometimes state mismatch between real pty state
and state variable occurs. For example, this occurs when 'ls'
command is executed in octave gui. This patch fixes the issue.
- After commit e1a0775dc0, the problem
reported in https://www.cygwin.com/ml/cygwin/2020-01/msg00093.html
occurs. For Gnu scren and tmux, calling FreeConsole() on pty close
is necessary. However, if FreeConsole() is called, cygwin setup
with '-h' option does not work. Therefore, the commit
e1a0775dc0 delayed closing pty.
This is the cause of the problem above. Now, instead of delaying
pty close, FreeConsole() is not called if the process is non cygwin
processes such as cygwin setup.
- The console with 24bit color support has a problem that console
mode is changed if cygwin process is executed in cmd.exe which
started in cygwin shell. For example, cursor keys become not
working if bash -> cmd -> true are executed in this order.
This patch fixes the issue.
- In Win10 1809, the cursor position sometimes goes out of screen
by clear command in console. This seems to be caused by escape
sequence CSI3J (ESC[3J). This happens only for 1809. This patch
is a workaround for the issue.
- Special function keys such as arrow keys or function keys do not
work in ConEmu with cygwin-connector after commit
6a06c6bc8f. This patch fixes the
issue.
- PTY code which support pseudo console has a problem that causes
handle leaks. Four of these are bug in pty code, and the other
one seems to be a bug of Windows10. ClosePseudoConsole() fails
to close one internal handle. This patch fixes the issue.
- If two PTYs are opened in the same process and the first one
is closed, the helper process for the first PTY remains running.
This patch fixes the issue.
- The slowing down issue of X11 forwarding using ssh -Y, reported
in https://www.cygwin.com/ml/cygwin/2019-12/msg00295.html,
is due to the change of select() code for pty in the commit
915fcd0ae8. cygthread::detach()
takes at most about 10msec because Sleep() is used in the thread.
For this issue, this patch uses cygwait() instead of Sleep() and
introduces an event to abort the wait. For not only pty, but pipe
and fifo also have the same problem potentially, so this patch
applies same strategy to them as well.
Though our implementation of cpu sets doesn't need it, software from
Linux environments expects this definition to be present. It's
documented on the Linux CPU_SET(3) man page but was left out due to
oversight.
Addresses https://cygwin.com/ml/cygwin/2019-12/msg00248.html
Add that flag to the pipe type argument when creating the Windows
named pipe. And add a definition of that flag to ntdll.h (copied from
/usr/include/w32api/ddk/ntifs.h).
- Even with commit fe512b2b12, pty
still has a problem in ESC[?3h and ESC[?3l handling if invalid
sequence such as ESC[?$ is sent. This patch fixes the issue.
Both functions were introduce with Windows 7 only, so we need to
autoload them for the sake of Vista/2008.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
On certain error conditions there is a code snippet that checks
whether the last component of the path has a trailing dot or space or
a leading space. Skip this check if the last component is empty,
i.e., if the path ends with a backslash. This avoids an assertion
failure if the trailing backslash is the only backslash in the path,
as is the case for a DOS drive 'X:\'.
Addresses: https://cygwin.com/ml/cygwin/2019-12/msg00016.html
- Pseudo console clears console screen buffer if ESC[?3h or ESC[?3l
is sent. However, xterm/vt100 does not clear screen. This cause
mismatch between real screen and console screen buffer. Therefore,
this patch triggers redraw screen in that situation so that the
synchronization is done on the next execution of native app.
This solves the problem reported in:
https://www.cygwin.com/ml/cygwin-patches/2019-q4/msg00116.html
- Previously, pty cleared screen at startup for synchronization
between the real screen and console screen buffer for pseudo
console. With this patch, instead of clearing screen, the screen
is redrawn when the first native program is executed after pty
is created. In other words, synchronization is deferred until
the native app is executed. Moreover, this realizes excluding
$TERM dependent code.
fhandler_console::create_invisible_console_workaround() does not use the
lpApplicationName parameter and neglects to quote its command name on
lpCommandLine in the call to CreateProcessW.
Given CreateProcessW's brain-dead method to evaluate the application
path given on the command line, this opens up a security problem if
Cygwin is installed into a path with spaces in it.
Fix this by using the lpApplicationName parameter and quoting of the
application path in the lpCommandLine parameter (used as argv[0] in
the called console helper.
For extended paranoia, make the argument string array big enough to
fit full 64 bit pointer values into it. Handles usually only use
the lower 32 bit, but better safe than sorry.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
FH_CONS_MAX should refelect the fact that we allow 128 consoles, even if
it's unused.
Suggested-by: Achim Gratz <Stromeko@nexgo.de>
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Commit 5a0f2c00aa "Cygwin: fork/exec: fix child process permissions"
removed the PROCESS_DUP_HANDLE handle permission of the parent process
handle in the child to avoid a security problem.
It turned out that this broke the following scenario: If a process forks
and then the parent execs, the child loses the ability to register the
parent's death. To wit, after the parent died the child process does
not set its own PPID to 1 anymore.
The current exec mechanism copies required handle values (handles to
keep contact to the child processes) into the child_info for the
about-to-be-exec'ed process. The exec'ed process is supposed to
duplicate these handles. This fails, given that we don't allow the
exec'ed process PROCESS_DUP_HANDLE access to the exec'ing process since
commit 5a0f2c00aa.
The fix is to avoid the DuplicateHandle calls in the exec'ed process.
This patch sets the affected handles to "inheritable" in the exec'ing
process at exec time. The exec'ed process just copies the handle values
and resets handle inheritance to "non-inheritable". The exec'ing
process doesn't have to reset handle inheritance, it exits after setting
up the exec'ed process anyway.
Testcase: $ ssh-agent /bin/sleep 3
ssh-agent forks and the parent exec's sleep. After sleep exits, `ps'
should show ssh-agent to have PPID 1, and eventually ssh-agent exits.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Call find_exec with the FE_NNF flag to enforce a NULL return when the
executable isn't found in $PATH. Convert NULL to "". This aligns
spawnvp and spawnvpe with execvp and execvpe.
If the directory name has the form 'x:' followed by one or more
slashes or backslashes, and if there's at least one backslash, assume
that the user is referring to 'x:\', the root directory of drive x,
and don't strip the backslash.
Previously all trailing slashes and backslashes were stripped, and the
name was treated as a relative file name containing a literal colon.
Addresses https://cygwin.com/ml/cygwin/2019-08/msg00334.html.
Ken Brown
Takashi Yano
Arseniy Lartsev
Mark Geisert
Corinna Vinschen
Anton Lavrentiev via cygwin-patches
Brian Inglis
Achim Gratz