Support -fsanitizer=address on ztest

cmd/zdb/Makefile.am

@@ -2,6 +2,8 @@ include $(top_srcdir)/config/Rules.am
 
 AM_CPPFLAGS += -DDEBUG
 
+AM_CFLAGS += $(FSANITIZE_ADDRESS)
+
 DEFAULT_INCLUDES += \
 	-I$(top_srcdir)/include \
 	-I$(top_srcdir)/lib/libspl/include

cmd/ztest/Makefile.am

@@ -3,6 +3,7 @@ include $(top_srcdir)/config/Rules.am
 # -Wnoformat-truncation to get rid of compiler warning for unchecked
 #  truncating snprintfs on gcc 7.1.1.
 AM_CFLAGS += $(DEBUG_STACKFLAGS) $(FRAME_LARGER_THAN) $(NO_FORMAT_TRUNCATION)
+AM_CFLAGS += $(FSANITIZE_ADDRESS)
 AM_CPPFLAGS += -DDEBUG -UNDEBUG
 
 DEFAULT_INCLUDES += \

config/user-compiler-options.m4

@@ -0,0 +1,62 @@
+dnl #
+dnl # Check if gcc supports -fsanitize=address. Applies to all libraries,
+dnl # ztest and zdb
+dnl #
+dnl # LDFLAGS needs -fsanitize=address at all times so libraries compiled with
+dnl # it will be linked successfully. CFLAGS will vary by binary being built.
+dnl #
+AC_DEFUN([ZFS_AC_CONFIG_USER_GCC_FSANITIZE], [
+	if test "$enable_debug" = "yes"
+	then
+		AC_MSG_CHECKING([for -fsanitize=address support])
+
+		saved_cflags="$CFLAGS"
+		saved_ldflags="$LDFLAGS"
+		CFLAGS="$CFLAGS -fsanitize=address"
+		LDFLAGS="$LDFLAGS -fsanitize=address"
+
+		AC_TRY_LINK(
+		[
+			#include <time.h>
+		],[
+			time_t now;
+			now = time(&now);
+		],[
+			FSANITIZE_ADDRESS=-fsanitize=address
+			saved_ldflags="$saved_ldflags -fsanitize=address"
+			AC_MSG_RESULT(yes)
+		],[
+			FSANITIZE_ADDRESS=""
+			AC_MSG_RESULT(no)
+		])
+
+		CFLAGS="$saved_flags"
+		LDFLAGS="$saved_ldflags"
+	fi
+	AC_SUBST([FSANITIZE_ADDRESS])
+])
+
+
+dnl #
+dnl # Check if gcc supports -Wframe-larger-than=<size> option.
+dnl #
+AC_DEFUN([ZFS_AC_CONFIG_USER_FRAME_LARGER_THAN], [
+	AC_MSG_CHECKING([for -Wframe-larger-than=<size> support])
+
+	saved_flags="$CFLAGS"
+	CFLAGS="$CFLAGS -Wframe-larger-than=4096"
+
+	AC_COMPILE_IFELSE([AC_LANG_PROGRAM([], [])],
+	[
+		FRAME_LARGER_THAN=-Wframe-larger-than=4096
+		AC_MSG_RESULT([yes])
+	],
+	[
+		FRAME_LARGER_THAN=
+		AC_MSG_RESULT([no])
+	])
+
+	CFLAGS="$saved_flags"
+	AC_SUBST([FRAME_LARGER_THAN])
+])
+

config/user.m4

@@ -15,6 +15,7 @@ AC_DEFUN([ZFS_AC_CONFIG_USER], [
 	ZFS_AC_CONFIG_USER_LIBUDEV
 	ZFS_AC_CONFIG_USER_LIBSSL
 	ZFS_AC_CONFIG_USER_FRAME_LARGER_THAN
+	ZFS_AC_CONFIG_USER_GCC_FSANITIZE
 	ZFS_AC_CONFIG_USER_RUNSTATEDIR
 	ZFS_AC_CONFIG_USER_MAKEDEV_IN_SYSMACROS
 	ZFS_AC_CONFIG_USER_MAKEDEV_IN_MKDEV

config/zfs-build.m4

@@ -27,7 +27,7 @@ AC_DEFUN([ZFS_AC_DEBUG], [
 	AC_MSG_CHECKING([whether assertion support will be enabled])
 	AC_ARG_ENABLE([debug],
 		[AS_HELP_STRING([--enable-debug],
-		[Enable assertion support @<:@default=no@:>@])],
+		[Enable compiler and code assertions @<:@default=no@:>@])],
 		[],
 		[enable_debug=no])
 

lib/libavl/Makefile.am

@@ -2,7 +2,7 @@ include $(top_srcdir)/config/Rules.am
 
 VPATH = $(top_srcdir)/module/avl/
 
-AM_CFLAGS += $(DEBUG_STACKFLAGS) $(FRAME_LARGER_THAN)
+AM_CFLAGS += $(DEBUG_STACKFLAGS) $(FRAME_LARGER_THAN) $(FSANITIZE_ADDRESS)
 
 DEFAULT_INCLUDES += \
 	-I$(top_srcdir)/include \

lib/libefi/Makefile.am

@@ -1,6 +1,6 @@
 include $(top_srcdir)/config/Rules.am
 
-AM_CFLAGS += $(DEBUG_STACKFLAGS) $(FRAME_LARGER_THAN)
+AM_CFLAGS += $(DEBUG_STACKFLAGS) $(FRAME_LARGER_THAN) $(FSANITIZE_ADDRESS)
 
 DEFAULT_INCLUDES += \
 	-I$(top_srcdir)/include \

lib/libicp/Makefile.am

@@ -4,7 +4,7 @@ VPATH = \
 	$(top_srcdir)/module/icp \
 	$(top_srcdir)/lib/libicp
 
-AM_CFLAGS += $(DEBUG_STACKFLAGS) $(FRAME_LARGER_THAN)
+AM_CFLAGS += $(DEBUG_STACKFLAGS) $(FRAME_LARGER_THAN) $(FSANITIZE_ADDRESS)
 
 DEFAULT_INCLUDES += \
 	-I$(top_srcdir)/include \

lib/libnvpair/Makefile.am

@@ -5,6 +5,7 @@ VPATH = \
 	$(top_srcdir)/lib/libnvpair
 
 AM_CFLAGS += $(DEBUG_STACKFLAGS) $(FRAME_LARGER_THAN) $(LIBTIRPC_CFLAGS)
+AM_CFLAGS += $(FSANITIZE_ADDRESS)
 
 DEFAULT_INCLUDES += \
 	-I$(top_srcdir)/include \

lib/libspl/Makefile.am

@@ -4,7 +4,7 @@ VPATH = \
 	$(top_srcdir)/lib/libspl \
 	$(top_srcdir)/lib/libspl/$(TARGET_ASM_DIR)
 
-AM_CFLAGS += $(DEBUG_STACKFLAGS) $(FRAME_LARGER_THAN)
+AM_CFLAGS += $(DEBUG_STACKFLAGS) $(FRAME_LARGER_THAN) $(FSANITIZE_ADDRESS)
 
 SUBDIRS = include $(TARGET_ASM_DIR)
 DIST_SUBDIRS = include asm-generic asm-i386 asm-x86_64

lib/libtpool/Makefile.am

@@ -1,6 +1,6 @@
 include $(top_srcdir)/config/Rules.am
 
-AM_CFLAGS += $(DEBUG_STACKFLAGS)
+AM_CFLAGS += $(DEBUG_STACKFLAGS) $(FSANITIZE_ADDRESS)
 
 DEFAULT_INCLUDES += \
 	-I$(top_srcdir)/include \

lib/libunicode/Makefile.am

@@ -2,7 +2,7 @@ include $(top_srcdir)/config/Rules.am
 
 VPATH = $(top_srcdir)/module/unicode
 
-AM_CFLAGS += $(DEBUG_STACKFLAGS) $(FRAME_LARGER_THAN)
+AM_CFLAGS += $(DEBUG_STACKFLAGS) $(FRAME_LARGER_THAN) $(FSANITIZE_ADDRESS)
 
 DEFAULT_INCLUDES += \
 	-I$(top_srcdir)/include \

lib/libuutil/Makefile.am

@@ -1,6 +1,6 @@
 include $(top_srcdir)/config/Rules.am
 
-AM_CFLAGS += $(DEBUG_STACKFLAGS) $(FRAME_LARGER_THAN)
+AM_CFLAGS += $(DEBUG_STACKFLAGS) $(FRAME_LARGER_THAN) $(FSANITIZE_ADDRESS)
 
 DEFAULT_INCLUDES += \
 	-I$(top_srcdir)/include \

lib/libzpool/Makefile.am

@@ -5,7 +5,7 @@ VPATH = \
 	$(top_srcdir)/module/zcommon \
 	$(top_srcdir)/lib/libzpool
 
-AM_CFLAGS += $(DEBUG_STACKFLAGS) $(FRAME_LARGER_THAN)
+AM_CFLAGS += $(DEBUG_STACKFLAGS) $(FRAME_LARGER_THAN) $(FSANITIZE_ADDRESS)
 
 DEFAULT_INCLUDES += \
 	-I$(top_srcdir)/include \

module/zfs/spa.c

@@ -1563,7 +1563,7 @@ spa_load_spares(spa_t *spa)
 static void
 spa_load_l2cache(spa_t *spa)
 {
-	nvlist_t **l2cache;
+	nvlist_t **l2cache = NULL;
 	uint_t nl2cache;
 	int i, j, oldnvdevs;
 	uint64_t guid;
@@ -1647,7 +1647,9 @@ spa_load_l2cache(spa_t *spa)
 	VERIFY(nvlist_remove(sav->sav_config, ZPOOL_CONFIG_L2CACHE,
 	    DATA_TYPE_NVLIST_ARRAY) == 0);
 
-	l2cache = kmem_alloc(sav->sav_count * sizeof (void *), KM_SLEEP);
+	if (sav->sav_count > 0)
+		l2cache = kmem_alloc(sav->sav_count * sizeof (void *),
+		    KM_SLEEP);
 	for (i = 0; i < sav->sav_count; i++)
 		l2cache[i] = vdev_config_generate(spa,
 		    sav->sav_vdevs[i], B_TRUE, VDEV_CONFIG_L2CACHE);