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: 3d322ac930ca ("Cygwin: fix initializing MEM_EXTENDED_PARAMETER")
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
MEM_EXTENDED_PARAMETER consists of a 64 bit bitfield which contains
the Type and the Reserved members. The former usage of designated
initializer lists initialized Type, but not Reserved. Since that's
not possible anymore due to a g++ 11.2 bug, Cygwin initializes the
MEM_EXTENDED_PARAMETER structs explicitely. This results in a
random value in Reserved, which at least VirtualAlloc2 chokes on
(ERROR_INVALID_PARAMETER).
Set Reserved explicitely to 0 for a fix.
Fixes: bdb7991db38b ("Cygwin: workaround a g++ 11.2 initialization bug")
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
The handle is created non-inheritable but gets inheritable when
dup'ing the file descriptor. Fix that.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Modern gcc's generate additional DWARF 5 debug sections, which were
still missing in our Cygwin loader script. With ld from binutils 2.37,
this results in diagnostic output when linking the Cygwin DLL...
ld: cygwin0.dll:/4: section below image base
ld: cygwin0.dll:/20: section below image base
ld: cygwin0.dll:/36: section below image base
...and the section addresses given to these sections (.debug_loclists,
.debug_rnglists, debug_line_str) will be wrong.
Fix this by adding the missing DWARF 5 sections to our linker script
template cygwin.sc.in. Add a comment in terms of the deprecated
DWARF 4 section .debug_types.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Signed-off-by: Jon Turney <jon.turney@dronecode.org.uk>
This was used before switching to automake to allow easy tweaking
of optimization and debugging settings from the command line during
testing. Reenable.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
trying to use aggregate initialization syntax on a member of a
nameless union member failes in g++ 11.2.
Workaround this by using explicit initialization.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
The GCC diagnostic ignored "-Wstringop-overflow" pragma doesn't work
as expected anymore. Use the still working expression.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
The register keyword was already deprecated with C++11, but
with C++17 it has been entirely removed.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Revert mx parameter and mutex lock while operating the list.
Mutex was removed with 94d24160 informing that:
'Use InterlockedCompareExchangePointer to ensure race safeness
without using a mutex.'
But it does not.
Calling pthread_mutex_init and pthread_mutex_destroy from two or
more threads occasionally leads to hang in pthread_mutex_destroy.
To not change the behaviour of other cases where List_insert was called,
List_insert_nolock is added.
As outlined in the previous patch, the non-atomicity of iterating
over a directory in the NT namespace via NtQueryDirectoryObject
one entry each, results in potential duplication of directory entries.
Fix this for fhandler_procsys::readdir as well by fetching the entire
dir inside fhandler_procsys::opendir, storing it in a buffer, and just
return buffer content from fhandler_procsys::readdir.
Fixes: 43f65cdd7dae ("fhandler_procsys.cc: New file.")
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Due to reports on the Cygwin mailing list[1][2], it was uncovered
that a NtOpenDirectoryObject/NtQueryDirectoryObject/NtClose sequence
with NtQueryDirectoryObject iterating over the directory entries,
one entry per invocation, is not running atomically. If new entries
are inserted into the queried directory, other entries may be moved
around and then accidentally show up twice while iterating.
Change (almost) all NtQueryDirectoryObject invocations so that it gets
a really big buffer (64K) and ideally fetches all entries at once.
This appears to work atomically.
"Almost" all, because fhandler_procsys::readdir can't be easily changed.
[1] https://cygwin.com/pipermail/cygwin/2021-July/248998.html
[2] https://cygwin.com/pipermail/cygwin/2021-August/249124.html
Fixes: e9c8cb31930bd ("(format_proc_partitions): Revamp loop over existing harddisks by scanning the NT native \Device object directory and looking for Harddisk entries.")
Fixes: a998dd7055766 ("Implement advisory file locking.")
Fixes: 3b7cd74bfdf56 ("(winpids::enum_processes): Fetch Cygwin processes from listing of shared cygwin object dir in the native NT namespace.")
Fixes: 0d6f2b0117aa7 ("syscalls.cc (sync_worker): Rewrite using native NT functions.")
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Commit 3434d35a64736f0b77a12f61784c2caa33ac44cf fixed a problem when
accessing block devices via their /proc/sys/Device entries. This
changed the way stat info is generated for these devices, resulting
in identical inode numbers for all block devices under /proc/sys/Device.
This patch fixes that by faking a device number for these devices, just as
before.
Fixes: 3434d35a6473 ("Cygwin: Fix access to block devices below /proc/sys.")
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Make sure to cast to ulong all DWORD values displayed with format "%lu".
More instances are fixed here than in either my earlier unused patch or
Corinna's patch. I decided to use typedef..ulong for more compact code.
Address jturney's reported small issues:
- Remove explicit external ref for cygwin_internal() as it is already
provided by <sys/cygwin.h>.
- Leave intact ref for cygwin_dll_path[] as it is required by function(s)
in path.cc that profiler uses. Added comment to that effect.
- Delete existing main() wrapper. Rename main2() to main(). This because
profiler is now a Cygwin program and doesn't need to dynamically load
cygwin1.dll.
- Documentation issues will be addressed in a separate xml patch.
(I would have linked message-ids of Corinna's and Jon's messages for
proper theading but I no longer have their original emails and the mail
archives don't show msgids any more.)
The doc for gmondump says 1 or more FILENAME are expected, but 0 is
handled. That's an oversight. Make invocation with 0 FILENAMEs print a
one-line help message.
Reword the beginning of profiler's description doc to clarify target's
child processes are run but only optionally profiled.
If a service is supported as TCP and UDP service, GetAddrInfo does not
return two entries, one for TCP, one for UDP, as on Linux. Rather, it
just returns a single entry with ai_socktype and ai_protocol set to 0.
If the service only exists as TCP or UDP service, then ai->ai_socktype
is set, but ai_protocol isn't.
Fortunately we copy over the result from Windows into local storage
anyway, so this patch adds code to fix up the fields neglected by
Windows. In case ai_socktype as well as ai_protocol are 0, duplicate
the entry with valid values for ai_socktype and ai_protocol.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
