summaryrefslogtreecommitdiff
path: root/misc/sbrk.c
diff options
context:
space:
mode:
authorJakub Jelinek <jakub@redhat.com>2007-07-12 18:26:36 +0000
committerJakub Jelinek <jakub@redhat.com>2007-07-12 18:26:36 +0000
commit0ecb606cb6cf65de1d9fc8a919bceb4be476c602 (patch)
tree2ea1f8305970753e4a657acb2ccc15ca3eec8e2c /misc/sbrk.c
parent7d58530341304d403a6626d7f7a1913165fe2f32 (diff)
downloadglibc-0ecb606cb6cf65de1d9fc8a919bceb4be476c602.tar.gz
2.5-18.1
Diffstat (limited to 'misc/sbrk.c')
-rw-r--r--misc/sbrk.c56
1 files changed, 56 insertions, 0 deletions
diff --git a/misc/sbrk.c b/misc/sbrk.c
new file mode 100644
index 0000000000..0df60076cc
--- /dev/null
+++ b/misc/sbrk.c
@@ -0,0 +1,56 @@
+/* Copyright (C) 1991,1995,1996,1997,2000,2002 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, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+#include <unistd.h>
+#include <errno.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 (__brk (oldbrk + increment) < 0)
+ return (void *) -1;
+
+ return oldbrk;
+}
+libc_hidden_def (__sbrk)
+weak_alias (__sbrk, sbrk)