- After commit bb428520, there has been the disadvantage:
7) Pseudo console cannot be activated if it is already activated for
another process on same pty.
This patch clears this disadvantage.
- After commit bb428520, there has been the disadvantage:
2) The apps which use console API cannot be debugged with gdb. This
is because pseudo console is not activated since gdb uses
CreateProcess() rather than exec(). Even with this limitation,
attaching gdb to native app, in which pseudo console is already
activated, works.
This patch clears this disadvantage.
- PTY has a problem that the key input, which is typed during windows
native app is running, disappears when it returns to shell. This is
beacuse pty has two input pipes, one is for cygwin apps and the other
one is for native windows apps. The key input during windows native
program is running is sent to the second input pipe while cygwin
shell reads input from the first input pipe. This issue had been
fixed once by commit 29431fcb, however, the new implementation of
pseudo console support by commit bb428520 could not inherit this
feature. This patch realize transfering input data between these
two pipes bidirectionally by utilizing cygwin-console-helper process.
The helper process is launched prior to starting the non-cygwin app,
however, exits immediately unlike previous implementation.
- After commit 232fde0e, pty changes console code page when the first
non-cygwin app is executed. If pty is started in real console device,
pty changes the code page of root console. This causes very annoying
result because changing code page changes the font of command prompt
if console is in legacy mode. This patch avoids this by creating a
new invisible console for the first pty started in console device.
- The function close_pseudoconsole() should be static so that it
can be safely called in spawn.cc even after the fhandler_pty_slave
instance has been deleted. That is, there is a problem with the
current code. This patch fixes the issue.
- If application changes the console mode, mode management introduced
by commit 10d8c278 will be corrupted. For example, stdout of jansi
v2.0.1 or later is piped to less, jansi resets the xterm mode flag
ENABLE_VIRTUAL_TERMINA_PROCESSING when jansi is terminated. This
causes garbled output in less because less needs this flag enabled.
This patch fixes the issue.
- Pseudo console internally sends escape sequence CSI6n (query cursor
position) on startup of non-cygwin apps. If the terminal does not
support CSI6n, CreateProcess() hangs waiting for response. To prevent
hang, this patch disables pseudo console if the terminal does not
have CSI6n. This is checked on the first execution of non-cygwin
app using the following steps.
1) Check if the terminal support ANSI escape sequences by looking
into terminfo database. If terminfo has cursor_home (ESC [H),
the terminal is supposed to support ANSI escape sequences.
2) If the terminal supports ANSI escape sequneces, send CSI6n for
a test and wait for a responce for 40ms.
3) If there is a responce within 40ms, CSI6n is supposed to be
supported.
Also set-title capability is checked, and removes escape sequence
for setting window title if the terminal does not have the set-
title capability.
pinfo::remember with the detach parameter set to true is
the only way to call proc_subproc with PROC_DETACHED_CHILD.
This call is exclusively used in spawn to set up a pinfo for
a detached child, and that pinfo goes out of scope right
afterwards without any further action.
Drop the flag and drop the detach parameter from pinfo::remember.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
After patch 23a779bf3d
"Cygwin: pinfo: stop remember doing reattach",
PROC_ADDCHILD actually just sets up a new child, mirroring
PROC_DETACHED_CHILD. The actual attaching of the child is
performed by action PROC_REATTACH_CHILD or pinfo::reattach
respectively.
To better reflect what's going on, rename PROC_REATTACH_CHILD
to PROC_ATTACH_CHILD and rename pinfo::reattach to pinfo::attach.
For better readability change PROC_ADDCHILD to PROC_ADD_CHILD.
Fix comments accordingly.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
- In this implementation, pseudo console is created for each native
console app. Advantages and disadvantages of this implementation
over the previous implementation are as follows.
Advantages:
1) No performance degradation in pty output for cygwin process.
https://cygwin.com/pipermail/cygwin/2020-February/243858.html
2) Free from the problem caused by difference of behaviour of control
sequences between real terminal and pseudo console.
https://cygwin.com/pipermail/cygwin/2019-December/243281.htmlhttps://cygwin.com/pipermail/cygwin/2020-February/243855.html
3) Free from the problem in cgdb and emacs gud.
https://cygwin.com/pipermail/cygwin/2020-January/243601.htmlhttps://cygwin.com/pipermail/cygwin/2020-March/244146.html
4) Redrawing screen on executing native console apps is not necessary.
5) cygwin-console-helper is not necessary for the pseudo console
support.
6) The codes for pseudo console support are much simpler than that
of the previous one.
Disadvantages:
1) The cygwin program which calls console API directly does not work.
2) The apps which use console API cannot be debugged with gdb. This
is because pseudo console is not activated since gdb uses
CreateProcess() rather than exec(). Even with this limitation,
attaching gdb to native apps, in which pseudo console is already
activated, works.
3) Typeahead key inputs are discarded while native console app is
executed. Simirally, typeahead key inputs while cygwin app is
executed are not inherited to native console app.
4) Code page cannot be changed by chcp.com. Acctually, chcp works
itself and changes code page of its own pseudo console. However,
since pseudo console is recreated for another process, it cannot
inherit the code page.
5) system_printf() does not work after stderr is closed. (Same with
cygwin 3.0.7)
6) Startup time of native console apps is about 3 times slower than
previous implemenation.
7) Pseudo console cannot be activated if it is already activated for
another process on same pty.
- After commit 095972ce5b, charset
conversion in mintty is broken if charset is set to other than
UTF-8. This seems to be caused because mintty does not set locale
yet at fork() call. This patch changes the timing of set_locale()
call again to avoid this issue.
- If a lot of mintty are started in a short time from a mintty, some
of them hang with empty screen, crash immediately or hang on exiting
mintty. The following report seems to be related to this issue.
https://cygwin.com/pipermail/cygwin/2020-August/245751.html
The cause is not clear at all, but this patch seems to solve the
issue.
Newlib's posix_spawn has been taken from FreeBSD. The code relies on
BSD-specific behaviour of vfork, namely the fact that vfork blocks
the parent until the child exits or calls execve as well as the fact
that the child shares parent memory in non-COW mode.
This behaviour can't be emulated by Cygwin. Cygwin's vfork is
equivalent to fork. This is POSIX-compliant, but it's lacking BSD's
vfork ingrained synchronization of the parent to wait for the child
calling execve, or the chance to just write a variable and the parent
will see the result.
So this requires a Cygwin-specific solution. The core function of
posix_spawn, called do_posix_spawn is now implemented twice, once using
the BSD method, and once for Cygwin using Windows synchronization under
the hood waiting for the child to call execve and signalling errors
upstream. The Windows specifics are hidden inside Cygwin, so newlib
only calls internal Cygwin functions.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
- If two cygwin programs are executed simultaneousley with pipes
in cmd.exe, xterm compatible mode is accidentally disabled by
the process which ends first. After that, escape sequences are
not handled correctly in the other app. This is the problem 2
reported in https://cygwin.com/ml/cygwin/2020-02/msg00116.html.
This patch fixes the issue. This patch also fixes the problem 3.
For these issues, the timing of setting and unsetting xterm
compatible mode is changed. For read, xterm compatible mode is
enabled only within read() or select() functions. For write, it
is enabled every time write() is called, and restored on close().
- 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.
- 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.
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.
- Previously, input and output pipes were switched together between
the traditional pty and the pseudo console. However, for example,
if stdin is redirected to another device, it is better to leave
input pipe traditional pty side even for non-cygwin program. This
patch realizes such behaviour.
- When the I/O pipe is switched to the pseudo console side, the
behaviour of Ctrl-C was unstable. This rarely happens, however,
for example, shell sometimes crashes by Ctrl-C in that situation.
Furthermore, Ctrl-C was ignored if output of non-cygwin program
is redirected to pipe. This patch fixes these issues.
- Pseudo console support introduced by commit
169d65a577 sometimes cause random
crash or freeze by pressing ^C while cygwin and non-cygwin
processes are executed simultaneously in the same pty. This
patch is a workaround for this issue.
- Pseudo console support introduced by commit
169d65a577 has some bugs which
cause mismatch between state variables and real pseudo console
state regarding console attaching and r/w pipe switching. This
patch fixes this issue by redesigning the state management.
- Support pseudo console in PTY. Pseudo console is a new feature
in Windows 10 1809, which provides console APIs on virtual
terminal. With this patch, native console applications can work
in PTYs such as mintty, ssh, gnu screen or tmux.
When the exec family of functions is called for a script-like
file, the av::setup function handles the exec[vl]p case as
well. The execve case for files not starting with a she-bang
is handled first by returning ENOEXEC. Only after that, the
file's executability is checked.
This leads to the problem that ENOEXEC is returned for non-executable
files as well. A calling shell interprets this as a file it should try
to run as script. This is not desired for non-executable files.
Fix this problem by checking the file for executability first. Only
after that, follow the other potential code paths.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
During fork, the child process requires the process table to be
initialized for fixup_shms_after_fork, while still allowing subsequent
dlls.load_after_fork to fail silently (for when the "forkable" hardlinks
are not created yet).
pinfo::remember not performing reattach anymore requires explicit
pinfo::reattach now where appropriate.
Prepares to improve "Cygwin: fork: Remember child not before success."
commit f03ea8e1c5, which leads to fork
problems if cygserver is running:
https://cygwin.com/ml/cygwin-patches/2019-q2/msg00155.html
commit d1be0a59d4,
"Cygwin: winpids: Fix getting process multiple times"
fixed duplicate processes in ps -W output, but it fixed
the symptom, not the cause. It also didn't fix the problem
that the `ps' process itself may show up twice in its own
output.
This patch fixes it. The spawn worker only deleted the
"winpid.PID" symlink of the current process if the child is
a non-Cygwin process, under the assumption that the exec'ing
process exits anyway. However, the Window in which both
winpid.PID symlinks point to the same cygpid.PID area is just
too long. The spawn worker now also deletes its own winpid.PID
symlink if the exec'ed process is a Cygwin process.
Additionally the fix from d1be0a59d4
is now performed on the calling process, too.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Create process with standard rights, plus
PROCESS_QUERY_LIMITED_INFORMATION for authenticated users. This
allows to fetch basic process information and thus /proc/<PID>/stat
to succeed on foreign processes.
While at it, fix formatting in CreateProcess calls.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
When calling spawnve, in contrast to execve, the parent has
to create the pid for the child. With the old technique
this was simply the Windows pid, but now we have to inform
the child about its new pid.
Add a cygpid member to class child_info_spawn. Set it in
child_info_spawn::worker, just prior to calling CreateProcess
rather than afterwards. Overwrite cygheap->pid in
child_info_spawn::handle_spawn before calling pinfo::thisproc.
Make sure pinfo::thisproc knows the pid is already set by
setting the handle argument to INVALID_HANDLE_VALUE.
Also set procinfo->dwProcessId to myself_initial.dwProcessId
instead of to myself_initial.pid for clarity.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
- If the execve'ed process is a non-Cygwin process, we have to
create the matching winpid symlink and remove the old one
ourselves.
- If we spawn a child, the winpid symlink has to be maintained
by the child process, otherwise it disappears if the parent
process exits.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Using the Windows PID as Cygwin PID has a few drawbacks:
- the PIDs on Windows get reused quickly. Some POSIX applications choke
on that, so we need extra code to avoid too quick PID reuse.
- The code to avoid PID reuse keeps parent process handles and
(depending on a build option) child processes open unnecessarily.
- After an execve, the process has a split personality: Its Windows PID
is a new PID, while its Cygwin PID is the PID of the execve caller
process. This requires to keep two procinfo shared sections open, the
second just to redirect process info requests to the first, correct
one.
This patch changes the way Cygwin PIDs are generated:
- Cygwin PIDs are generated independently of the Windows PID, in a way
expected by POSIX processes. The PIDs are created incrementally in
the range between 2 and 65535, round-robin.
- On startup of the first Cygwin process, choose a semi-random start PID
for the first process in the lower PID range to make the PIDs slightly
unpredictable. This may not be necessary but it seems kind of inviting
to know that the first Cygwin process always starts with PID 2.
- Every process not only creates the shared procinfo section, but also a
symlink in the NT namespace, symlinking the Windows PID to the Cygwin
PID. This drops the need for the extra procinfo section after execve.
- Don't keep other process handles around unnecessarily.
- Simplify the code creating/opening the shared procinfo section and
make a clear distinction between interfaces getting a Cygwin PID and
interfaces getting a Windows PID.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Always create child user window station and desktop, unless only
spawning with restricted token. Also fix formatting of a few comments
in child_info_spawn::worker.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Bump GPLv2+ to GPLv3+ for some files, clarify BSD 2-clause.
Everything else stays under GPLv3+.
New Linking Exception exempts resulting executables from LGPLv3 section 4.
Add CONTRIBUTORS file to keep track of licensing.
Remove 'Copyright Red Hat Inc' comments.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
suffix and make private. Rename normalized_path to posix_path and
make privtae. Accommodate name changes throughout in path_conv
methods.
(path_conv::known_suffix): New method. Use throughout instead of
accessing suffix directly.
(path_conv::get_win32): Constify.
(path_conv::get_posix): New method to read posix_path. Use throughout
instead of accessing normalized_path directly.
(path_conv::set_posix): Rename from set_normalized_path. Accommodate
name change throughout.
* spawn.cc (find_exec): Return POSIX path, not Win32 path.
(gfpod_helper): Drop equality sign from environment variable name
in call to check_path_access.
* exec.cc (execlp): Drop equality sign from environment variable name
in call to find_exec.
(execvp): Ditto.
(execvpe): Ditto.
* path.h (enum fe_types): Drop FE_NATIVE.
(find_exec): Rename third paramter in declaration from search. Drop
equality sign from default value.
* spawn.cc (perhaps_suffix): Add PC_POSIX to path_conv::check call.
(find_exec): Simplify function. Iterate over POSIX pathlist rather
than Windows pathlist. Drop handling of FE_NATIVE flag. Always fill
posix path of incoming path_conv buf, unless FE_NNF flag is given.
(av::setup): Drop equality sign from environment variable name
in call to find_exec. Call unshift with normalized_path.
* winf.cc (av::unshift): Drop conv parameter and code converting
Windows to POSIX path.
* winf.h (av::unshift): Accommodate prototype.
Explain why.
(lockf_t::create_lock_obj): Use FALSE, rather than 0 for BOOL argument.
(lockf_t::del_lock_obj): Check if NtSetEvent succeeded and print system
message if not.
(DestroyEnvironmentBlock): Import.
* environ.cc (env_compare): New static bsearch comparison function.
(build_env): Add parameter taking a user token. If token is non-NULL,
fetch user's default Windows environment and merge it into the resulting
environment. Explain what we do in preceeding comment.
* environ,h (build_env): Align prototype to above change.
* external.cc (create_winenv): Call build_env with NULL token.
* spawn.cc (child_info_spawn::worker): When spawning new process under
another user account, call build_env with new token to allow merging
user's default Windows environment.
* winlean.h (_USERENV_): Define to override dllimport.
Takashi Yano via Cygwin-patches
Corinna Vinschen
Takashi Yano
Ken Brown
Michael Haubenwallner
Peter Foley
Corinna Vinschen