a24ad2c346
* fcntl.cc (fcntl64): Drop handling of locking commands. * fhandler.h (class fhandler_disk_file): Add mandatory_locking. (fhandler_disk_file::fcntl): Declare. (fhandler_disk_file::mand_lock): Declare. * fhandler_disk_file.cc (fhandler_disk_file::fhandler_disk_file): Initialize mandatory_locking. (fhandler_disk_file::fcntl): New method. Handle F_LCK_MANDATORY and locking commands. (fhandler_disk_file::dup): Duplicate mandatory_locking. Fix a bug when duplicating prw_handle failed. (fhandler_disk_file::fixup_after_fork): Reset mandatory_locking. * flock.cc (fhandler_disk_file::lock): Add comment. (struct lock_parms): New struct to pass parameters to blocking_lock_thr thread function. (blocking_lock_thr): New thread function. (fhandler_disk_file::mand_lock): New methof implementing mandatory locking with Windows semantics. * ntdll.h (NtLockFile): Declare. (NtUnlockFile): Declare. * include/fcntl.h: Fix a comment. (F_LCK_MANDATORY): Define. Add lengthy comment to explain.
123 lines
3.0 KiB
C++
123 lines
3.0 KiB
C++
/* fcntl.cc: fcntl syscall
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Copyright 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2005, 2008, 2009,
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2010, 2011, 2012, 2013 Red Hat, Inc.
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This file is part of Cygwin.
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This software is a copyrighted work licensed under the terms of the
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Cygwin license. Please consult the file "CYGWIN_LICENSE" for
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details. */
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#include "winsup.h"
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#include <unistd.h>
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#include "cygerrno.h"
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#include "security.h"
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#include "path.h"
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#include "fhandler.h"
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#include "dtable.h"
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#include "cygheap.h"
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#include "cygtls.h"
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extern "C" int
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fcntl64 (int fd, int cmd, ...)
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{
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int res = -1;
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intptr_t arg = 0;
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va_list args;
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pthread_testcancel ();
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debug_printf ("fcntl(%d, %d, ...)", fd, cmd);
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myfault efault;
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if (efault.faulted (EFAULT))
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return -1;
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cygheap_fdget cfd (fd, true);
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if (cfd < 0)
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goto done;
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/* FIXME? All numerical args to fcntl are defined as long on Linux.
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This relies on a really dirty trick on x86_64: A 32 bit mov to
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a register (e.g. mov $1, %edx) always sets the high 32 bit to 0.
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We're following the Linux lead here since the third arg to any
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function is in a register anyway (%r8 in MS ABI). That's the easy
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case which is covered here by always reading the arg with
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sizeof (intptr_t) == sizeof (long) == sizeof (void*) which matches
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all targets.
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However, the POSIX standard defines all numerical args as type int.
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If we take that literally, we had a (small) problem on 64 bit, since
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sizeof (void*) != sizeof (int). If we would like to follow POSIX
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more closely than Linux, we'd have to call va_arg on a per cmd basis. */
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va_start (args, cmd);
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arg = va_arg (args, intptr_t);
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va_end (args);
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switch (cmd)
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{
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case F_DUPFD:
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case F_DUPFD_CLOEXEC:
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if (arg >= 0 && arg < OPEN_MAX_MAX)
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{
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int flags = cmd == F_DUPFD_CLOEXEC ? O_CLOEXEC : 0;
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res = cygheap->fdtab.dup3 (fd, cygheap_fdnew ((arg) - 1), flags);
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}
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else
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{
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set_errno (EINVAL);
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res = -1;
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}
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break;
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default:
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res = cfd->fcntl (cmd, arg);
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break;
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}
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done:
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syscall_printf ("%R = fcntl(%d, %d, %ly)", res, fd, cmd, arg);
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return res;
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}
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#ifdef __x86_64__
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EXPORT_ALIAS (fcntl64, fcntl)
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EXPORT_ALIAS (fcntl64, _fcntl)
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#else
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extern "C" int
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_fcntl (int fd, int cmd, ...)
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{
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intptr_t arg = 0;
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va_list args;
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struct __flock32 *src = NULL;
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struct flock dst;
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myfault efault;
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if (efault.faulted (EFAULT))
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return -1;
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va_start (args, cmd);
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arg = va_arg (args, intptr_t);
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va_end (args);
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if (cmd == F_GETLK || cmd == F_SETLK || cmd == F_SETLKW)
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{
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src = (struct __flock32 *) arg;
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dst.l_type = src->l_type;
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dst.l_whence = src->l_whence;
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dst.l_start = src->l_start;
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dst.l_len = src->l_len;
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dst.l_pid = src->l_pid;
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arg = (intptr_t) &dst;
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}
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int res = fcntl64 (fd, cmd, arg);
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if (cmd == F_GETLK)
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{
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src->l_type = dst.l_type;
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src->l_whence = dst.l_whence;
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src->l_start = dst.l_start;
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src->l_len = dst.l_len;
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src->l_pid = (short) dst.l_pid;
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}
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return res;
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}
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#endif
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