Submitted By: Robert Connolly <cendres at videotron dot ca> (ashes)
Date: 2004-02-26
Initial Package Version: 2.3.3
Origin: http://www.openwall.com/Owl/
http://www.gtlib.cc.gatech.edu/pub/gentoo/gentoo-x86-portage/sys-libs/glibc/\
	files/2.3.3/glibc-2.3.3-owl-malloc-unlink-sanity-check.diff
Description: A sanity fix from the Owl Linux Project.
http://www.linuxfromscratch.org/~robert/winter/

diff -Naur glibc-2.3.3-20040213.orig/malloc/malloc.c glibc-2.3.3-20040213/malloc/malloc.c
--- glibc-2.3.3-20040213.orig/malloc/malloc.c	2003-12-17 23:31:28.000000000 +0000
+++ glibc-2.3.3-20040213/malloc/malloc.c	2004-02-26 09:08:49.000000000 +0000
@@ -315,6 +315,11 @@
 #define assert(x) ((void)0)
 #endif
 
+/* needed for owl-malloc-unlink-sanity-check */
+#include <abort-instr.h>
+#ifndef ABORT_INSTRUCTION
+#define ABORT_INSTRUCTION
+#endif
 
 /*
   INTERNAL_SIZE_T is the word-size used for internal bookkeeping
@@ -1954,6 +1959,14 @@
 #define unlink(P, BK, FD) {                                            \
   FD = P->fd;                                                          \
   BK = P->bk;                                                          \
+  /* owl-malloc-unlink-sanity-check */                                 \
+  if (FD->bk != P || BK->fd != P)                                      \
+  {                                                                    \
+    ABORT_INSTRUCTION;                                                 \
+    _exit(127);                                                        \
+    while (1)                                                          \
+      ABORT_INSTRUCTION;                                               \
+  }                                                                    \
   FD->bk = BK;                                                         \
   BK->fd = FD;                                                         \
 }