- As mentioned in commit message of the commit b531d6b0, if multiple
writers including non-cygwin app exist, the non-cygwin app cannot
detect pipe closure on the read side when the pipe is created by
system account or the the pipe creator is running as service.
This is because query_hdl which is held in write side also is a
read end of the pipe, so the pipe is still alive for the non-cygwin
app even after the reader is closed.
To avoid this problem, this patch lets all processes in the same
process group close query_hdl using newly introduced internal signal
__SIGNONCYGCHLD when non-cygwin app is started.
Addresses: https://cygwin.com/pipermail/cygwin/2022-March/251097.html
- Using memcmp() to compare structure such as INPUT_RECORD is not
correct manner because padding may not be initialized. This patch
stops to use memcmp() for comparison of INPUT_RECORD.
- dwControlKeyState also may be null'ed on WriteConsoleInputW().
Therefore ignore it in event comparison as well as wVirtualKeyCode
and wVirtualScanCode.
- The commit "Cygwin: console: Improve the code to avoid typeahead
key swapping." did not solve the problem enough. Two unexpected
things happen.
(1) wVirtualKeyCode and wVirtualScanCode of readback key event may
be null'ed even if they are not zero on WriteConsoleInputW().
Therefore, memcmp() may report the event sequence is not equal.
(2) WriteConsoleInputW() may not be atomic. The event sequence
which is written by WriteConsoleInputW() may be inserted by
key input in the middle of the sequence. Current code gives
up to fix in this situation.
This patch should fix that issue.
- If UNC path for DFS is mounted to a drive with drive letter, the
error "Too many levels of symbolic links" occurs when accessing
to that drive. This is because GetDosDeviceW() returns unexpected
string such as "\Device\Mup\DfsClient\;Z:000000000003fb89\dfsserver
\dfs\linkname" for the mounted UNC path "\??\UNC\fileserver\share".
This patch adds a workaround for this issue.
Addresses: https://cygwin.com/pipermail/cygwin/2022-March/250979.html
- After the commit "Cygwin: pty, console: Fix handle leak which
occurs on exec() error.", startxwin cannot start X due to the
error "Failed to activate virtual core keyboard: 2". The problem
is access violation in the code retrieving the pgid of the ctty.
This patch fixes the issue.
Addresses: https://cygwin.com/pipermail/cygwin/2022-March/251013.html
- Currently, tty::pcon_start flag is cleared before transfer_input()
in master::write(), however, the code in setup_pseudoconsole()
waits for transfer_input() using tty::pcon_start. This possibly
causes the race issue. The patch fixes this potential issue.
- To make read() work properly in canonical mode, writing to the pty
pipe should be done line by line. However, only CR was treated as
line separator previously in transfer_input(). This patch fixes
the issue.
- transfer_input() function uses console api, so it should be guarded
by attach_mutex. However, in most cases, it is missing. This patch
fixes the issue.
- This patch revises the acquiring/releasing timing for attach_mutex
to make the period in which it is being acquired shorter. Further,
acquiring/releasing are added to where they are missing but needed.
The "how" value only makes sense if a new set is given. If we
only read the current signal set, ignore the value of "how" per
POSIX:
"If set is a null pointer, the value of the argument how is not
significant"
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
- When Ctrl-C terminates a non-cygwin process on a pseudo console,
pty master attaches to the pseudo console first, and send
CTRL_C_EVENT. If the non-cygwin process closes the pseudo console
before the pty master calls FreeConsole(), the pty master process
will crash. With this patch, pty master process takes over the
ownership of the pseudo console, and closes it by myself.
- With this patch, unique invisible consoles are created for each pty
to isolate CTRL_C_EVENTs between ptys. This is necessary by Ctrl-C
handling in fhandler_termios::process_sigs() for non-cygwin apps
started in pty if the pseudo console is disabled.
- The commit "Cygwin: console: Prevent the order of typeahead input
from swapped." did not fully resolve the issue. If keys are typed
during input buffer fix, the order of key event may be swapped.
This patch fixes the issue again.
- The recent commit "Cygwin: pinfo: Fix exit code when non-cygwin app
exits by Ctrl-C." did not fix enough the issue. If a non-cygwin app
is reading the console, it will not return STATUS_CONTROL_C_EXIT
even if it is terminated by Ctrl-C. As a result, the previous patch
does not take effect.
This patch solves this issue by setting sigExeced to SIGINT in
ctrl_c_handler(). In addition, sigExeced will be cleared if the app
does not terminated within predetermined time period. The reason is
that the app does not seem to be terminated by the signal sigExeced.
- The commit "Cygwin: console: Fix issues of apps which open pty."
did not fix the second problem correctly. That commit looked to
fix the issue, but the actual problem was that ctrl_c_handler()
should be reregistered *AFTER* FreeConsole()/AttachConsole().
This patch correct that.
- The commit "Cygwin: console: Restore CTRL_BREAK_EVENT handling."
was accidentally mixed with experimental code in exceptions.cc.
Due to this, non-cygwin app receives CTRL_C_EVENT twice in the
following scenario.
1) Run 'sleep 10 | <non-cygwin app>'
2) Hit Ctrl-C.
3) The non-cygwin app receives CTRL_C_EVENT twice.
This patch reverts the code with the problem.
- If a lot of keys are typed very quickly in the app which does
not read console, the order of input keys in console input buffer
occasionally swapped. Although this extremely rarely happens,
is obviously a bug of cons_master_thread. This patch fixes the
issue.
- The commit "Cygwin: console: Redesign handling of special keys."
removes special treatment for pty in with pseudo console activated,
however, it is necessary on second thought. This is because sending
CTRL_C_EVENT to non-cygwin apps will be done in pseudo console,
therefore, sending it in fhandler_pty_master::write() duplicates
that event for non-cygwin apps.
- After some recent changes for special keys handling break the
apps which open pty (such as script command). If the app which
opens pty is executed in console, the following issues occur.
1) If the script command was started from non-cygwin shell
(such as cmd.exe), another cygwin app started in pty slave
cannot receive Ctrl-C.
2) If non-cygwin app is executed in pty slave, the app which
opened the pty (e.g. script command) crashes by Ctrl-C.
This patch fixes these issues.
- Previously, if non-cygwin app exits by Ctrl-C, exit code was
0x00007f00. With this patch, the exit code will be 0x00000002,
which means process exited by SIGINT.
- The recent change by the commit "Cygwin: console: Redesign handling
of special keys." breaks the handling of CTRL_BREAK_EVENT. The login
shell in console exits on Ctrl-Break key. This patch fixes the issue.
- The inferior of the GDB cannot be continued after SIGINT even
though nopass option is set. This seems because cygwin GDB does
not support hooking cygwin signal. Therefore, a workaround for
GDB is added. With this patch, only CTRL_C_EVENT is sent to the
GDB inferior by Ctrl-C and sending SIGINT is omitted. Note that
"handle SIGINT (no)pass" command does not take effect even with
or without this patch.
- This patch rearranges the cooperation between cons_master_thread,
line_edit, and ctrl_c_handler so that only one of them operates
at the same time. Since these handle Ctrl-C individually, so the
signal may be sent multiple times to the process. This patch fixes
the issue.
- This patch fixes the handle leak which occurs when exec() fails
with an error. The duplicated handles will be closed when the
exec'ed process is terminated. However, if exec() fails, the code
path does not reach to the code closing the duplicated handles.
To implement this fix more appropriately, the setup, cleanup and
closing pty codes which was previously located in spawn.cc are
encapsulated into the fhandler_pty_slave class functions.
- With this patch, all set_(in|out)put_mode() calls are rearranged
as follows.
1) Setup for cygwin apps, started from non-cygwin app, is done
in fhandler_console::post_open_setup(), which overrides
fhandler_base::post_open_setup() called from dtable.cc.
2) Cleanup for cygwin app is done in fhandler_console::close().
3) Setup for cygwin apps is also in fhandler_console::bg_check(),
which overrides fhandler_termios::bg_check(). This is called
on read(), write() and select() for console. It is necessary
if cygwin and non-cygwin apps are started simultaneously in
the same process group.
4) Setup for non-cygwin apps is done in spawn.cc via
fhandler_console::setup_console_for_non_cygwin_app().
5) Cleanup for non-cygwin app is done in spawn.cc vid
fhandler_console::cleanup_console_for_non_cygwin_app().
6) Setup for non-cygwin app started by GDB is done in
fhandler_console::set_console_mode_to_native().
7) No explicit cleanup for non-cygwin app started by GDB, because
console mode is automatically reset to tty::cygwin on read()/
write() in GDB thanks to 3).
- This patch commonize the code which processes special keys in pty
and console to improve maintanancibility. As a result, some small
bugs have been fixed.
- When non-cygwin app is started in console, console mode is set to
tty::native. However, if stdin is redirected, current code does not
set the input mode of the console. In this case, if the app opens
"CONIN$", the console mode will not be appropriate for non-cygwin
app. This patch fixes the issue.
Addresses:
https://github.com/GitCredentialManager/git-credential-manager/issues/576
- Currently, there is no chance to change console mode for non-cygwin
inferior of GDB. With this patch, the console mode is changed to
tty::native in CreateProcess() and ContinueDebugEvent() hooked in
fhandler_console.
- In tty_min::setpgid(), a pointer to fhandler instance is casted to
fhandler_pty_slave and accessed even if terminal is not a pty slave.
This patch fixes the issue.
- Currently, pty discards input only in from_master pipe on signal.
Due to this, if pty is started without pseudo console support and
start a non-cygwin process from cmd.exe, type adhead input is not
discarded on signals such as Ctrl-C. This patch fixes the issue.
- With this patch, the code to wait for completion of forwarding of
output from non-cygwin app is revised so that it can more reliably
detect the completion.
- If the slave process writes a lot of text output, doecho() can
cause deadlock. This is because output_mutex is held in slave::
write() and if WriteFile() is blocked due to pipe full, doecho()
tries to acquire output_mutex and gets into deadlock. With this
patch, the deadlock is prevented on the sacrifice of atomicity
of doecho().
- Previously, non-cygwin app running in pty started without pseudo
console support was suspended by Ctrl-Z rather than sending EOF.
Even worse, suspended app could not be resumed by fg command. With
this patch, Ctrl-Z (EOF for non-cygwin apps) is passed to non-cygwin
app instead of suspending that app. This patch also handles Ctrl-\
(QUIT) and Ctrl-D (EOF) as well.
- Currently, if cat is started from cmd.exe which is started in cygwin
console, Ctrl-C terminates not only cat but also cmd.exe. This also
happens in pty in which pseudo console is disabled. This patch fixes
the issue.
