3 files changed, 13 insertions, 1 deletions
diff --git a/usr/src/lib/libumem/common/envvar.c b/usr/src/lib/libumem/common/envvar.c
index 0c4d872814..6c57d9553e 100644
--- a/usr/src/lib/libumem/common/envvar.c
+++ b/usr/src/lib/libumem/common/envvar.c
@@ -26,6 +26,7 @@
 
 /*
  * Copyright (c) 2012 Joyent, Inc. All rights reserved.
+ * Copyright (c) 2015 by Delphix. All rights reserved.
  */
 
 #include <ctype.h>
@@ -226,6 +227,10 @@ static umem_env_item_t umem_debug_items[] = {
 		"Enables writing all logged messages to stderr",
 		&umem_output,	2
 	},
+	{ "checknull",		"Private",	ITEM_FLAG,
+		"Abort if an allocation would return null",
+		&umem_flags,	UMF_CHECKNULL
+	},
 
 	{ NULL, "-- end of UMEM_DEBUG --",	ITEM_INVALID }
 };
diff --git a/usr/src/lib/libumem/common/umem.c b/usr/src/lib/libumem/common/umem.c
index 00028e5f80..dbc738a049 100644
--- a/usr/src/lib/libumem/common/umem.c
+++ b/usr/src/lib/libumem/common/umem.c
@@ -26,6 +26,7 @@
 
 /*
  * Copyright (c) 2014 Joyent, Inc.  All rights reserved.
+ * Copyright (c) 2015 by Delphix. All rights reserved.
  */
 
 /*
@@ -1234,6 +1235,9 @@ umem_alloc_retry(umem_cache_t *cp, int umflag)
 		 * Initialization failed.  Do normal failure processing.
 		 */
 	}
+	if (umem_flags & UMF_CHECKNULL) {
+		umem_err_recoverable("umem: out of heap space");
+	}
 	if (umflag & UMEM_NOFAIL) {
 		int def_result = UMEM_CALLBACK_EXIT(255);
 		int result = def_result;
@@ -1377,7 +1381,7 @@ umem_log_enter(umem_log_header_t *lhp, void *data, size_t size)
 
 static void
 umem_log_event(umem_log_header_t *lp, umem_cache_t *cp,
-	umem_slab_t *sp, void *addr)
+    umem_slab_t *sp, void *addr)
 {
 	umem_bufctl_audit_t *bcp;
 	UMEM_LOCAL_BUFCTL_AUDIT(&bcp);
diff --git a/usr/src/lib/libumem/common/umem_impl.h b/usr/src/lib/libumem/common/umem_impl.h
index f63246e166..7d5056f172 100644
--- a/usr/src/lib/libumem/common/umem_impl.h
+++ b/usr/src/lib/libumem/common/umem_impl.h
@@ -26,6 +26,7 @@
 
 /*
  * Copyright (c) 2012 Joyent, Inc.  All rights reserved.
+ * Copyright (c) 2015 by Delphix. All rights reserved.
  */
 
 #ifndef _UMEM_IMPL_H
@@ -68,6 +69,8 @@ extern "C" {
 #define	UMF_RANDOMIZE	0x00000400	/* randomize other umem_flags */
 #define	UMF_PTC		0x00000800	/* cache has per-thread caching */
 
+#define	UMF_CHECKNULL	0x00001000	/* heap exhaustion checking */
+
 #define	UMF_BUFTAG	(UMF_DEADBEEF | UMF_REDZONE)
 #define	UMF_TOUCH	(UMF_BUFTAG | UMF_LITE | UMF_CONTENTS)
 #define	UMF_RANDOM	(UMF_TOUCH | UMF_AUDIT | UMF_NOMAGAZINE)