Restore --enable-ivsalloc.

However, unlike before it was removed do not force --enable-ivsalloc
when Darwin zone allocator integration is enabled, since the zone
allocator code uses ivsalloc() regardless of whether
malloc_usable_size() and sallocx() do.

This resolves #211.

ChangeLog

@@ -133,8 +133,6 @@ found in the git revision history:
   - Remove the "stats.huge.allocated", "stats.huge.nmalloc", and
     "stats.huge.ndalloc" mallctls.
   - Remove the --enable-mremap option.
-  - Remove the --enable-ivsalloc option, and merge its functionality into
-    --enable-debug.
   - Remove the "stats.chunks.current", "stats.chunks.total", and
     "stats.chunks.high" mallctls.
 

INSTALL

@@ -92,6 +92,7 @@ any of the following arguments (not a definitive list) to 'configure':
 --enable-debug
     Enable assertions and validation code.  This incurs a substantial
     performance hit, but is very useful during application development.
+    Implies --enable-ivsalloc.
 
 --enable-code-coverage
     Enable code coverage support, for use during jemalloc test development.
@@ -110,6 +111,11 @@ any of the following arguments (not a definitive list) to 'configure':
     Disable statistics gathering functionality.  See the "opt.stats_print"
     option documentation for usage details.
 
+--enable-ivsalloc
+    Enable validation code, which verifies that pointers reside within
+    jemalloc-owned chunks before dereferencing them.  This incurs a minor
+    performance hit.
+
 --enable-prof
     Enable heap profiling and leak detection functionality.  See the "opt.prof"
     option documentation for usage details.  When enabled, there are several

configure.ac

@@ -625,7 +625,8 @@ fi
 
 dnl Do not compile with debugging by default.
 AC_ARG_ENABLE([debug],
-  [AS_HELP_STRING([--enable-debug], [Build debugging code])],
+  [AS_HELP_STRING([--enable-debug],
+                  [Build debugging code (implies --enable-ivsalloc)])],
 [if test "x$enable_debug" = "xno" ; then
   enable_debug="0"
 else
@@ -637,8 +638,28 @@ fi
 if test "x$enable_debug" = "x1" ; then
   AC_DEFINE([JEMALLOC_DEBUG], [ ])
 fi
+if test "x$enable_debug" = "x1" ; then
+  AC_DEFINE([JEMALLOC_DEBUG], [ ])
+  enable_ivsalloc="1"
+fi
 AC_SUBST([enable_debug])
 
+dnl Do not validate pointers by default.
+AC_ARG_ENABLE([ivsalloc],
+  [AS_HELP_STRING([--enable-ivsalloc],
+                  [Validate pointers passed through the public API])],
+[if test "x$enable_ivsalloc" = "xno" ; then
+  enable_ivsalloc="0"
+else
+  enable_ivsalloc="1"
+fi
+],
+[enable_ivsalloc="0"]
+)
+if test "x$enable_ivsalloc" = "x1" ; then
+  AC_DEFINE([JEMALLOC_IVSALLOC], [ ])
+fi
+
 dnl Only optimize if not debugging.
 if test "x$enable_debug" = "x0" -a "x$no_CFLAGS" = "xyes" ; then
   dnl Make sure that an optimization flag was not specified in EXTRA_CFLAGS.

include/jemalloc/internal/jemalloc_internal.h.in

@@ -119,6 +119,13 @@ static const bool config_xmalloc =
     false
 #endif
     ;
+static const bool config_ivsalloc =
+#ifdef JEMALLOC_IVSALLOC
+    true
+#else
+    false
+#endif
+    ;
 
 #ifdef JEMALLOC_C11ATOMICS
 #include <stdatomic.h>

include/jemalloc/internal/jemalloc_internal_defs.h.in

@@ -186,6 +186,12 @@
 #undef JEMALLOC_INTERNAL_FFSL
 #undef JEMALLOC_INTERNAL_FFS
 
+/*
+ * JEMALLOC_IVSALLOC enables ivsalloc(), which verifies that pointers reside
+ * within jemalloc-owned chunks before dereferencing them.
+ */
+#undef JEMALLOC_IVSALLOC
+
 /*
  * Darwin (OS X) uses zones to work around Mach-O symbol override shortcomings.
  */

src/jemalloc.c

@@ -2306,7 +2306,7 @@ je_sallocx(const void *ptr, int flags)
 	assert(malloc_initialized() || IS_INITIALIZER);
 	malloc_thread_init();
 
-	if (config_debug)
+	if (config_ivsalloc)
 		usize = ivsalloc(ptr, config_prof);
 	else
 		usize = isalloc(ptr, config_prof);
@@ -2434,7 +2434,7 @@ je_malloc_usable_size(JEMALLOC_USABLE_SIZE_CONST void *ptr)
 	assert(malloc_initialized() || IS_INITIALIZER);
 	malloc_thread_init();
 
-	if (config_debug)
+	if (config_ivsalloc)
 		ret = ivsalloc(ptr, config_prof);
 	else
 		ret = (ptr == NULL) ? 0 : isalloc(ptr, config_prof);