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.
There are a few files that are tied to the GNU simulator, so add myself
to match the general sim project.
Also add myself to the general write-after-approval since I've been doing
that for a long time now anyways :).
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>
When newlib is configured with --enable-newlib-reent-check-verify,
the assert macro is already defined in the nano-mallocr.c compile unit.
Contributed by STMicroelectronics
Signed-off-by: Torbjörn SVENSSON <torbjorn.svensson@st.com>
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: bdb7991db3 ("Cygwin: workaround a g++ 11.2 initialization bug")
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
libm/machine/i386/f_ldexp.S:30: Warning: no instruction mnemonic suffix given and no register operands; using default for `fild'
libm/machine/i386/f_ldexpf.S:30: Warning: no instruction mnemonic suffix given and no register operands; using default for `fild'
fix this by adding the l mnemonic suffix
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
unused function warning for two_way_short_needle,
different char type warnings for standard string functions
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
_STDIO_WITH_THREAD_CANCELLATION_SUPPORT was never defined.
Include ../stdio/local.h to get the right definition per target.
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>
__STDINT_EXP() is provided by newlib but not by stdint-gcc.h. stdint-gcc.h
is used when the GCC argument -ffreestanding is used and this results in this
file not compiling.
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>
This patch to the libc/machine/nvptx port of newlib implements an
approximation of "clock" and provides some additional stub routines.
These changes not only reduce the number of (link) failures in the GCC
testsuite when targeting nvptx-none, but also allow the NIST scimark4
benchmark to compile and run without modification.
newlib already contains support for backends to provide their own
clock implementations via -DCLOCK_PROVIDED. That functionality is
used here to return an approximate elapsed time based on the NVidia
GPU's clock64 cycle counter. Although not great, this is better than
the current behaviour of link error from the unresolved symbol
_times_r.
The other part of the patch is to add a small number of stub functions
to nvptx's misc.c. Adding isatty, for example, resolves linking
problems in libc from the dependency in __smakebuf_r, and the sync
stub, for example, fixes the failure with GCC's
testsuite/gfortran.dg/ISO_Fortran_binding_14.f90 [which simply tests
that gfortran can call a/any C function].
newlib/
configure.host: Add -DCLOCK_PROVIDED to newlib_cflags on nvptx*.
newlib/libc/machine/nvptx
Makefile.am: Add clock.c to lib_a_SOURCES.
clock.c: New source file to implement/approximate clock().
misc.c: Add stubs for fstat, isatty, open, sync and unlink.
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.
_strtod_l as well as the gethex function both fetch the decimal point
from the current LC_NUMERIC locale info. This pulls in _C_numeric_locale
unconditionally even on targets not supporting locales at all.
Another problem is that strtod.c and gdtoa-gethex.c are ELIX 1, while
locale information in general isn't. This leads to potential build
breakage on bare metal targets.
Fix this by setting the decimal point to "." on all targets not
defining __HAVE_LOCALE_INFO__.
While at it, const'ify the entire local decimal point info in the
affected functions.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
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: 43f65cdd7d ("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: e9c8cb3193 ("(format_proc_partitions): Revamp loop over existing harddisks by scanning the NT native \Device object directory and looking for Harddisk entries.")
Fixes: a998dd7055 ("Implement advisory file locking.")
Fixes: 3b7cd74bfd ("(winpids::enum_processes): Fetch Cygwin processes from listing of shared cygwin object dir in the native NT namespace.")
Fixes: 0d6f2b0117 ("syscalls.cc (sync_worker): Rewrite using native NT functions.")
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Commit 3434d35a64 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: 3434d35a64 ("Cygwin: Fix access to block devices below /proc/sys.")
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
svfwscanf replaces getwc and ungetwc_r. The comments in the code talk
about avoiding file operations, but they also need to bypass the
mbtowc calls as svfwscanf operates on wchar_t, not multibyte data,
which is a more important reason here; they would not work correctly
otherwise.
The ungetwc replacement has code which uses the 3 byte FILE _ubuf
field, but if wchar_t is 32-bits, this field is not large enough to
hold even one wchar_t value. Building in this mode generates warnings
about array overflow:
In file included from ../../newlib/libc/stdio/svfiwscanf.c:35:
../../newlib/libc/stdio/vfwscanf.c: In function '_sungetwc_r.isra':
../../newlib/libc/stdio/vfwscanf.c:316:12: warning: array subscript 4294967295 is above array bounds of 'unsigned char[3]' [-Warray-bounds]
316 | fp->_p = &fp->_ubuf[sizeof (fp->_ubuf) - sizeof (wchar_t)];
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from ../../newlib/libc/stdio/stdio.h:46,
from ../../newlib/libc/stdio/vfwscanf.c:82,
from ../../newlib/libc/stdio/svfiwscanf.c:35:
../../newlib/libc/include/sys/reent.h:216:17: note: while referencing '_ubuf'
216 | unsigned char _ubuf[3]; /* guarantee an ungetc() buffer */
| ^~~~~
However, the vfwscanf code *never* ungets data before the start of the
scanning operation, and *always* ungets data which matches the input
at that point, so the code always hits the block which backs up over
the input data and never hits the block which uses the _ubuf field.
In addition, the svfwscanf code will always start with the unget
buffer empty, so the ungetwc replacement never needs to support an
unget buffer at all.
Simplify the code by removing support for everything other than
backing up over the input data, leaving the check to make sure it
doesn't get underflowed in case the vfscanf code has a bug in it.
Signed-off-by: Keith Packard <keithp@keithp.com>
Added function prototypes to newlib/libc/include/pthread.h
for the following Issue 8 Standard APIs:
pthread_cond_clockwait()
pthread_mutex_clocklock()
pthread_rwlock_clockrdlock()
pthread_rwlock_clockwrlock()
The current implementation does not reliably initialize t0 once.
Additionally the initialization requires two calls to _gettimeofday().
Let's sacrifice a byte to keep the initialization status
and reduce the maximum number of calls to _gettimeofday().
This has caused issues in an application that invokes clock().
The problematic situation is as follows:
1) The program calls clock() which calls _times().
2) _gettimeofday(&t0, 0) puts 0 in t0.tv_usec (because less than 1 us has
elapsed since the beginning of time).
3) _gettimeofday(&t, 0) puts 1 in t.tv_usec (since now more than 1 us has
elapsed since the beginning of time).
4) That call to clock() returns 1 (the value from step 3 minus the value in
step 2).
5) The program does a second call to clock().
6) The code above still sees 0 in t0 so it tries to update t0 again and
_gettimeofday(&t0, 0) puts 1 in t0.tv_usec.
7) The _gettimeofday(&t, 0) puts 1 in t.tv_usec (since less than 1us has
elapsed since step 3).
8) clock() returns 0 (step 7 minus step 6) and indicates that time is
moving backwards.
Signed-off-by: Christoph Muellner <cmuellner@gcc.gnu.org>
Corinna Vinschen
Ken Brown
Takashi Yano
Mike Frysinger
Torbjorn SVENSSON via Newlib
Joel Sherrill
Roger Sayle
Aleksand Malikov
Keith Packard
Matt Joyce
Christoph Muellner