Prepare for radical source tree reorganization.zack/build-layout-experiment

All top-level files and directories are moved into a temporary storage
directory, REORG.TODO, except for files that will certainly still
exist in their current form at top level when we're done (COPYING,
COPYING.LIB, LICENSES, NEWS, README), all old ChangeLog files (which
are moved to the new directory OldChangeLogs, instead), and the
generated file INSTALL (which is just deleted; in the new order, there
will be no generated files checked into version control).

1 files changed, 166 insertions, 0 deletions

diff --git a/REORG.TODO/sysdeps/mach/hurd/brk.c b/REORG.TODO/sysdeps/mach/hurd/brk.c
new file mode 100644
index 0000000000..a9154bffdd
--- /dev/null
+++ b/REORG.TODO/sysdeps/mach/hurd/brk.c
@@ -0,0 +1,166 @@
+/* Copyright (C) 1991-2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <hurd.h>
+#include <hurd/resource.h>
+#include <cthreads.h>		/* For `struct mutex'.  */
+
+
+/* Initial maximum size of the data segment (this is arbitrary).  */
+#define	DATA_SIZE	(128 * 1024 * 1024)
+
+/* Up to the page including this address is allocated from the kernel.
+   This address is the data resource limit.  */
+vm_address_t _hurd_data_end;
+
+/* Up to this address is actually available to the user.
+   Pages beyond the one containing this address allow no access.  */
+vm_address_t _hurd_brk = 0;
+
+/* This name is used by the Linux crtbeginS.o for reasons you don't even
+   want to think about it.  It's just easier to provide some definition for
+   it than even to explain the braindamage involved.  */
+weak_alias (_hurd_brk, ___brk_addr)
+
+struct mutex _hurd_brk_lock;
+
+extern int __data_start, _end;
+weak_extern (__data_start)
+static vm_address_t static_data_start;
+
+
+/* Set the end of the process's data space to INADDR.
+   Return 0 if successful, -1 if not.  */
+int
+__brk (void *inaddr)
+{
+  int ret;
+  HURD_CRITICAL_BEGIN;
+  __mutex_lock (&_hurd_brk_lock);
+  ret = _hurd_set_brk ((vm_address_t) inaddr);
+  __mutex_unlock (&_hurd_brk_lock);
+  HURD_CRITICAL_END;
+  return ret;
+}
+weak_alias (__brk, brk)
+
+
+int
+_hurd_set_brk (vm_address_t addr)
+{
+  error_t err = 0;
+  vm_address_t pagend = round_page (addr);
+  vm_address_t pagebrk = round_page (_hurd_brk);
+  long int rlimit;
+
+  if (pagend <= pagebrk)
+    {
+      if (pagend < pagebrk)
+	{
+	  /* XXX wish this were atomic... */
+	  /* First deallocate the memory to release its backing space.  */
+	  __vm_deallocate (__mach_task_self (), pagend, pagebrk - pagend);
+	  /* Now reallocate it with no access allowed.  */
+	  err = __vm_map (__mach_task_self (),
+			  &pagend, pagebrk - pagend,
+			  0, 0, MACH_PORT_NULL, 0, 0,
+			  0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE,
+			  VM_INHERIT_COPY);
+	  /* XXX what if error? */
+	}
+      _hurd_brk = addr;
+      return 0;
+    }
+
+  __mutex_lock (&_hurd_rlimit_lock);
+  rlimit = _hurd_rlimits[RLIMIT_DATA].rlim_cur;
+  __mutex_unlock (&_hurd_rlimit_lock);
+
+  if (addr - static_data_start > rlimit)
+    {
+      /* Need to increase the resource limit.  */
+      errno = ENOMEM;
+      return -1;
+    }
+
+  if (pagend > _hurd_data_end)
+    {
+      vm_address_t alloc_start = _hurd_data_end;
+
+      /* We didn't allocate enough space!  Hopefully we can get some more!  */
+
+      if (_hurd_data_end > pagebrk)
+	/* First finish allocation.  */
+	err = __vm_protect (__mach_task_self (), pagebrk,
+			    alloc_start - pagebrk, 0,
+			    VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
+      if (! err)
+	_hurd_brk = alloc_start;
+
+      if (! err)
+	err = __vm_allocate (__mach_task_self (), &alloc_start,
+			     pagend - alloc_start, 0);
+
+      if (! err)
+	_hurd_data_end = pagend;
+    }
+  else
+    /* Make the memory accessible.  */
+    err = __vm_protect (__mach_task_self (), pagebrk, pagend - pagebrk,
+			0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
+
+  if (err)
+    return __hurd_fail (err);
+
+  _hurd_brk = addr;
+  return 0;
+}
+
+static void
+init_brk (void)
+{
+  vm_address_t pagend;
+
+  __mutex_init (&_hurd_brk_lock);
+
+  static_data_start = (vm_address_t) (&__data_start ?: &_end);
+
+  /* If _hurd_brk is already set, don't change it.  The assumption is that
+     it was set in a previous run before something like Emacs's unexec was
+     called and dumped all the data up to the break at that point.  */
+  if (_hurd_brk == 0)
+    _hurd_brk = (vm_address_t) &_end;
+
+  pagend = round_page (_hurd_brk);
+
+  _hurd_data_end = round_page (static_data_start + DATA_SIZE);
+
+  if (pagend < _hurd_data_end)
+    {
+      /* We use vm_map to allocate and change permissions atomically.  */
+      if (__vm_map (__mach_task_self (), &pagend, _hurd_data_end - pagend,
+		    0, 0, MACH_PORT_NULL, 0, 0,
+		    0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE,
+		    VM_INHERIT_COPY))
+	/* Couldn't allocate the memory.  The break will be very short.  */
+	_hurd_data_end = pagend;
+    }
+
+  (void) &init_brk;		/* Avoid ``defined but not used'' warning.  */
+}
+text_set_element (_hurd_preinit_hook, init_brk);