When running Cygwin's Bash in the Windows Terminal (see
https://docs.microsoft.com/en-us/windows/terminal/ for details), Cygwin
is receiving keyboard input in the form of UTF-16 characters.
UTF-16 has that awkward challenge that it cannot map the full Unicode
range, and to make up for it, there are the ranges U+D800-U+DBFF and
U+DC00-U+DFFF which are illegal except when they come in a pair encoding
for Unicode characters beyond U+FFFF.
Cygwin does not handle such surrogate pairs correctly at the moment, as
can be seen e.g. when running Cygwin's Bash in the Windows Terminal and
then inserting an emoji (e.g. via Windows + <dot>, which opens an emoji
picker on recent Windows versions): Instead of showing an emoji, this
shows the infamous question mark in a black triangle, i.e. the invalid
Unicode character.
Let's special-case surrogate pairs in this scenario.
This fixes https://github.com/git-for-windows/git/issues/3281
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Use the same name as glibc & gnulib to indicate "newlib itself is
being compiled". This also harmonizes the codebase a bit in that
_LIBC was already used in places instead of _COMPILING_NEWLIB.
Building for bfin-elf, mips-elf, and x86_64-pc-cygwin produces
the same object code.
A recent change in binutils marks the .gnu_debuglink_overlay section
as debug section. When dllfixdbg calls objcopy -g, the section
is removed and the --add-gnu-debuglink option on the same command line
appends the section consequentially at the end of the sections.
This in turn breaks Windows Version info and, potentially, raising
the cygheap size at runtime.
Fix this by adding an explicit --keep-section=.gnu_debuglink_overlay
to the objcopy command line.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
isabspath handles a path "X:", without trailing slash or backslash,
as absolute path. This breaks some scenarios with relative paths
starting with "X:". For instance, fstatat will mishandle a call
with valid dirfd and "c:" as path.
The reason is that gen_full_path_at() will check for isabspath("C:")
which returns true. So the path will be used verbatim in fstatat,
rather than being converted to a path "<dirfd-path>/c:".
So, introduce isabspath_strict, which returns true for paths starting
with "X:" only if the next char is actually a slash or backslash.
Use it from gen_full_path_at().
This still fixes only half the problem. The right thing would have been
to disallow using DOS paths in the first place. Unfortunately it's much
too late for that.
Addresses: https://cygwin.com/pipermail/cygwin/2021-November/249837.html
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Cygwin always requests FILE_WRITE_ATTRIBUTES permissions when trying to
change DAC information. This can lead to permission problems when
trying to chmod/chown files on Samba shares. Drop requesting
FILE_WRITE_ATTRIBUTES on Samba shares and go with WRITE_DAC/WRITE_OWNER
only.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Also rename release 3.4.0 to 3.3.2. It doesn't make sense to
duplicate the issues fixed in 3.3.x into the 3.4.0 relnotes.
Only patches not backported into 3.3.x belong into 3.4.0.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
- Currently, bash occasionally exits by Ctrl-C with the following
scenario.
1) Start bash in the command prompt.
2) Run 'exec bash'.
3) Press Ctrl-C several times.
This patch fixes the issue.
- Currently, read() returns EINTR due to a bug if signal handler
is SIG_DFL and the process is suspended by Ctrl-Z and restarted.
This patch fixes the issue.
i. e. Vista/2008. This drops support for the sr_CS locale.
Regenerate LC_MESSAGES and LC_TIME ERA data from more recent Linux
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
i. e., Vista/2008.
AllocConsole appears to allow creating a console only on the currently
visible desktop since Windows 7, which broke the simple code opening
the console on an invisible desktop in an invisible window station.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Per https://cygwin.com/pipermail/cygwin-developers/2021-October/012429.html,
we may encounter a crash when starting multiple threads during process
startup (here: fhandler_fifo::fixup_after_{fork,exec}) which in turn
allocate memory via malloc.
The problem is concurrent usage of malloc before the malloc muto has
been initialized.
To fix this issue, convert the muto to a SRWLOCK and make sure it is
statically initalized. Thus, malloc can be called as early as necessary
and malloc_init is only required to check for user space provided malloc.
Note that this requires to implement a __malloc_trylock macro to be
called from fork.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
This patch unifies the layout of the clipboard descriptor cygcb_t for
32- and 64-bit Cygwin. It allows correct copy/paste between the two
environments without corruption of user's copied data and without access
violations due to interpreting that data as a size field.
The definitions of CYGWIN_NATIVE and cygcb_t are moved to a new include
file, sys/clipboard.h. The include file is used by fhandler_clipboard.cc
as well as getclip.c and putclip.c in the Cygwin cygutils package.
When copy/pasting between 32- and 64-bit Cygwin environments, both must
be running version 3.3.0 or later for successful operation.
- The commit b531d6b0 introduced temporary_query_hdl() which uses
SystemHandleInformation. With this patch, ProcessHandleInformation
rather than SystemHandleInformation is used if it is available.
This request is faster, however, is only available since Windows 8,
therefore, SystemHandleInformation is used for Windows Vista and 7
as before.
- The commit f79a4611 introduced query_hdl, which is the read pipe
handle kept in the write pipe instance in order to determine if
the pipe is ready to write in select(). This implementation has
a potential risk that the write side fails to detect the closure
of the read side if more than one writer exists and one of them
is a non-cygwin process.
With this patch, the strategy of commit f79a4611 is used only if
the process is running as a service. For a normal process,
instead of keeping query_hdl in the write pipe instance, it is
retrieved temporarily when select() is called. Actually, we
want to use tenporary query_hdl for all processes, however, it
does not work for service processes due to OpenProcess()
failure.
open_setup is called by dtable::init_std_file_from_handle and
fhandler_base::open_with_arch. In both cases, failure of open_setup
is now a fatal error.
Currently this can only happen in the following situation: A Cygwin
process is started by a non-Cygwin process, one of the standard IO
handles is a pipe handle, and Cygwin is unable to create a required
mutex (read_mtx or hdl_cnt_mtx).
- query_hdl and hdl_cnt_mtx are moved from fhandler_pipe_fifo to
fhandler_pipe. Then reader_closed() is changed to virtual and
overridden in fhandler_pipe.
- This patch fixes the race issue in the handle counting to detect
closure of read pipe, which is introduced by commit f79a4611.
A mutex hdl_cnt_mtx is introduced for this issue.
- Currently, the stderr handle is duplicated in close_all_files().
This interferes the handle counting for detecting closure of read
pipe, which is introduced by commit f79a4611. This patch stops
duplicating stderr handle if it is write pipe.
NtQueryInformationFile hangs if it's called on the read side handle of
a pipe while another thread or process is performing a blocking read.
Avoid select potentially hanging by calling NtQueryInformationFile
only on the write side of the pipe and using PeekNamedPipe otherwise.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
- In pipe_data_available() in select.cc, PeekNamedPipe() call is
not needed if WriteQuotaAvailable is non-zero because we already
know the write pipe has a space. Therefore, with this patch,
PeekNamedPipe() is called only when WriteQuotaAvailable is zero.
This makes select() on pipe faster a bit.
- Currently, raw_read(), raw_write() and close() release select_sem
unconditionally even if no waiter for select_sem exists. With this
patch, only the minimum number of semaphores required is released.
- Usually WriteQuotaAvailable retrieved by NtQueryInformationFile()
on the write side reflects the space available in the inbound buffer
on the read side. However, if a pipe read is currently pending,
WriteQuotaAvailable on the write side is decremented by the number
of bytes the read side is requesting. So it's possible (even likely)
that WriteQuotaAvailable is 0, even if the inbound buffer on the
read side is not full. This can lead to a deadlock situation:
The reader is waiting for data, but select on the writer side
assumes that no space is available in the read side inbound buffer.
Currently, to avoid this stuation, read() does not request larger
block than pipe size - 1. However, this mechanism does not take
effect if the reader side is non-cygwin app.
The only reliable information is available on the read side, so
fetch info from the read side via the pipe-specific query handle
(query_hdl) introduced.
If the query_hdl (read handle) is kept in write side, writer can
not detect closure of read pipe. Therefore, raw_write() counts
write handle and query_hdl. If they are equal, only the pairs of
write handle and query_hdl are alive. In this case, raw_write()
returns EPIPE and raises SIGPIPE.
- Nonblocking pipes (PIPE_NOWAIT) are not well handled by non-Cygwin
tools, so convert pipe handles to PIPE_WAIT handles when spawning
a non-Cygwin process.
We already fetched the correct SECURITY_ATTRIBUTES at the start of
fhandler_pipe::create, so using another SECURITY_ATTRIBUTES object for
the mutex and semaphore objects doesn't make much sense.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
select_sem gets created on the read side with inheritence settings
depending on the O_CLOEXEC flag. Then it gets duplicated to the write
side with unconditional inheritence. Fix that.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Fold all code branches potentially having read or written data into
a single if branch, so signalling select_sem catches all cases.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Rename fhandler_pipe_and_fifo::max_atomic_write to pipe_buf_size.
This reflect its actual meaning better. The fhandler_pipe_and_fifo
constructor initializes it to DEFAULT_PIPEBUFSIZE (== 64K), which is
the buffer size for the windows pipes created by fhandler_pipe and
fhandler_fifo. But if we inherit a stdio pipe handle from a
non-Cygwin process, the buffer size could be different.
To remedy this, add a method fhandler_pipe::set_pipe_buf_size that
queries the OS for the pipe buffer size, and use it in
dtable::init_std_file_from_handle.
Given we return 1 already if WriteQuotaAvailable is > 0, the condition
for tiny pipes is never true. Fix the comments.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
In blocking mode, the underlying IO must always be terminated,
one way or the other, to make sure the application knows the exact
state after returning from the IO function. Therefore, always call
CancelIo in blocking mode.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Just cancelling a thread doesn't cancel async IO started by this thread.
Fix this by returning from cygwait and calling CancelIo before canceling
self.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
- By guarding read with read_mtx, no more than one ReadFile can
be called simultaneously. So couting read handles is no longer
necessary.
- Make raw_read code as similar as possible to raw_write code.
This is a parent of fhandler_pipe and fhandler_fifo for code that is
common between the two classes. Currently it just contains
max_atomic_write and raw_write(). The latter is identical to what
used to be fhandler_pipe::raw_write().
FILE_PIPE_LOCAL_INFORMATION::WriteQuotaAvailable is unreliable.
Usually WriteQuotaAvailable on the write side reflects the space
available in the inbound buffer on the read side. However, if a
pipe read is currently pending, WriteQuotaAvailable on the write side
is decremented by the number of bytes the read side is requesting.
So it's possible (even likely) that WriteQuotaAvailable is 0, even
if the inbound buffer on the read side is not full. This can lead to
a deadlock situation: The reader is waiting for data, but select
on the writer side assumes that no space is available in the read
side inbound buffer.
This patch implements a workaround by never trying to read more than
half the buffer size blocking if the read buffer is empty. This first
cut tries to take the number of open readers into account by reducing
the amount of requested bytes accordingly.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
POSIX requires atomicity for non-blocking writes <= PIPE_BUF bytes
and writing of at least 1 byte if any buffer space is left.
Windows NtWriteFile returns STATUS_SUCCESS and "0 bytes written"
if the write doesn't match buffer space. Fix this discrepancy.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
The buffer pointer is incremented by "chunk", which is what we
typically try to write, but this isn't what actually got written.
Increment the buffer pointer by what we actually wrote, as returned
by NtWriteFile.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
get_obj_handle_count() is used in flock only so far, but pipe
handling might have a usage, too, soon. Given that this function
might be generally useful and isn't restricted to flock usage,
move it to miscfuncs.cc and make it non-static. Add a prototype
in miscfuncs.h.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
I wasted valuable minutes of my life just to find out why we export
this weird version of pipe. In the pre-2000 era the idea was Cygwin
could be used as drop-in replacement for msvcrt.dll, apparently.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
The read handles of pipes created by CreateNamedPipe don't have
FILE_WRITE_ATTRIBUTES access unless the pipe is created with
PIPE_ACCESS_DUPLEX. This causes set_pipe_non_blocking to fail on such
handles. To fix this, add a helper function nt_create, which uses
NtCreateNamedPipeFile instead of CreateNamedPipe and gives us more
flexibility in setting access rights.
Use this helper function in fhandler_pipe::create (fhandler_pipe *[2],
unsigned, int), which is the version of fhandler_pipe::create used by
the pipe and pipe2 system calls.
For convenience, also add a static member function
fhandler_pipe::npfs_handle similar to those used by fhandler_fifo and
fhandler_socket_unix.
Add methods 'set_pipe_non_blocking' and 'fcntl' to keep the blocking
mode of the Windows pipe in sync with that of the fhandler_pipe
object. This applies to pipes created with the 'pipe' and 'pipe2'
system calls.
Previously fhandler_pipe was derived from fhandler_base_overlapped,
which we are going to remove in a future commit. Make minimal changes
so that the build still succeeds.
In https://cygwin.com/pipermail/cygwin/2021-September/249361.html
Brian pointed out that initializing the structure would be more
future proof, should the developers at Microsoft ever decide to
split the Reserved field and use some bits of the struct for
other purposes.
Fixes: 3d322ac930 ("Cygwin: fix initializing MEM_EXTENDED_PARAMETER")
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Johannes Schindelin
Mike Frysinger
Corinna Vinschen
Takashi Yano
Mark Geisert
Ken Brown