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-rw-r--r--REORG.TODO/misc/sbrk.c64
1 files changed, 64 insertions, 0 deletions
diff --git a/REORG.TODO/misc/sbrk.c b/REORG.TODO/misc/sbrk.c
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+++ b/REORG.TODO/misc/sbrk.c
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+/* 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 <stdint.h>
+#include <unistd.h>
+
+/* Defined in brk.c.  */
+extern void *__curbrk;
+extern int __brk (void *addr);
+
+/* Defined in init-first.c.  */
+extern int __libc_multiple_libcs attribute_hidden;
+
+/* Extend the process's data space by INCREMENT.
+   If INCREMENT is negative, shrink data space by - INCREMENT.
+   Return start of new space allocated, or -1 for errors.  */
+void *
+__sbrk (intptr_t increment)
+{
+  void *oldbrk;
+
+  /* If this is not part of the dynamic library or the library is used
+     via dynamic loading in a statically linked program update
+     __curbrk from the kernel's brk value.  That way two separate
+     instances of __brk and __sbrk can share the heap, returning
+     interleaved pieces of it.  */
+  if (__curbrk == NULL || __libc_multiple_libcs)
+    if (__brk (0) < 0)		/* Initialize the break.  */
+      return (void *) -1;
+
+  if (increment == 0)
+    return __curbrk;
+
+  oldbrk = __curbrk;
+  if (increment > 0
+      ? ((uintptr_t) oldbrk + (uintptr_t) increment < (uintptr_t) oldbrk)
+      : ((uintptr_t) oldbrk < (uintptr_t) -increment))
+    {
+      __set_errno (ENOMEM);
+      return (void *) -1;
+    }
+
+  if (__brk (oldbrk + increment) < 0)
+    return (void *) -1;
+
+  return oldbrk;
+}
+libc_hidden_def (__sbrk)
+weak_alias (__sbrk, sbrk)