diff --git a/include/sys/debug.h b/include/sys/debug.h
index 3cde97635..0d7b0b772 100644
--- a/include/sys/debug.h
+++ b/include/sys/debug.h
@@ -218,17 +218,32 @@ struct page_collection {
 #define __ASSERT_TAGE_INVARIANT(x)	((void)0)
 #define ASSERT(x)			((void)0)
 #define ASSERTF(x, y, z...)	        ((void)0)
-#define VERIFY(x)                       ((void)(x))
+#define VERIFY(cond)                                                    \
+do {                                                                    \
+        if (unlikely(!(cond))) {                                        \
+                printk(KERN_ERR "VERIFY(" #cond ") failed\n");          \
+                SBUG();                                                 \
+        }                                                               \
+} while (0)
 
-#define VERIFY3_IMPL(x, y, z, t, f, c)  if ((x) == (z)) ((void)0)
+#define VERIFY3_IMPL(LEFT, OP, RIGHT, TYPE, FMT, CAST)                  \
+do {                                                                    \
+        if (!((TYPE)(LEFT) OP (TYPE)(RIGHT))) {                         \
+                printk(KERN_ERR "VERIFY3(" #LEFT " " #OP " " #RIGHT     \
+                       " failed (" FMT ", " FMT ")\n", CAST (LEFT),     \
+                       CAST (RIGHT));                                   \
+                SBUG();                                                 \
+        }                                                               \
+} while (0)
 
-#define VERIFY3S(x,y,z)	VERIFY3_IMPL(x, y, z, int64_t, "%ld", (long))
-#define VERIFY3U(x,y,z) VERIFY3_IMPL(x, y, z, uint64_t, "%lu", (unsigned long))
+#define VERIFY3S(x,y,z) VERIFY3_IMPL(x, y, z, int64_t, "%lld", (long long))
+#define VERIFY3U(x,y,z) VERIFY3_IMPL(x, y, z, uint64_t, "%llu",         \
+                                     (unsigned long long))
 #define VERIFY3P(x,y,z) VERIFY3_IMPL(x, y, z, uintptr_t, "%p", (void *))
 
-#define ASSERT3S(x,y,z) VERIFY3S(x, y, z)
-#define ASSERT3U(x,y,z) VERIFY3U(x, y, z)
-#define ASSERT3P(x,y,z) VERIFY3P(x, y, z)
+#define ASSERT3S(x,y,z) ((void)0)
+#define ASSERT3U(x,y,z) ((void)0)
+#define ASSERT3P(x,y,z) ((void)0)
 
 #else /* NDEBUG */
 
@@ -270,7 +285,7 @@ do {                                                                    \
 #define __ASSERT(cond)                                                  \
 do {                                                                    \
         if (unlikely(!(cond))) {                                        \
-                printk(KERN_ERR "ASSERTION(" #cond ") failed");         \
+                printk(KERN_ERR "ASSERTION(" #cond ") failed\n");       \
                 BUG();                                                  \
         }                                                               \
 } while (0)
@@ -322,8 +337,9 @@ do {                                                                    \
         }                                                               \
 } while (0)
 
-#define VERIFY3S(x,y,z) VERIFY3_IMPL(x, y, z, int64_t, "%ld", (long))
-#define VERIFY3U(x,y,z) VERIFY3_IMPL(x, y, z, uint64_t, "%lu", (unsigned long))
+#define VERIFY3S(x,y,z) VERIFY3_IMPL(x, y, z, int64_t, "%lld", (long long))
+#define VERIFY3U(x,y,z) VERIFY3_IMPL(x, y, z, uint64_t, "%llu`",        \
+                                     (unsigned long long))
 #define VERIFY3P(x,y,z) VERIFY3_IMPL(x, y, z, uintptr_t, "%p", (void *))
 
 #define ASSERT3S(x,y,z) VERIFY3S(x, y, z)
diff --git a/modules/spl/spl-kmem.c b/modules/spl/spl-kmem.c
index 3b5ecfb46..e580fbbdd 100644
--- a/modules/spl/spl-kmem.c
+++ b/modules/spl/spl-kmem.c
@@ -222,6 +222,18 @@ kmem_alloc_track(size_t size, int flags, const char *func, int line,
 			    (unsigned long long) size, flags,
 			    atomic64_read(&kmem_alloc_used), kmem_alloc_max);
 
+		/* We use kstrdup() below because the string pointed to by
+		 * __FUNCTION__ might not be available by the time we want
+		 * to print it since the module might have been unloaded. */
+		dptr->kd_func = kstrdup(func, flags & ~__GFP_ZERO);
+		if (unlikely(dptr->kd_func == NULL)) {
+			kfree(dptr);
+			CWARN("kstrdup() failed in kmem_alloc(%llu, 0x%x) "
+			    "(%lld/%llu)\n", (unsigned long long) size, flags,
+			    atomic64_read(&kmem_alloc_used), kmem_alloc_max);
+			goto out;
+		}
+
 		/* Use the correct allocator */
 		if (node_alloc) {
 			ASSERT(!(flags & __GFP_ZERO));
@@ -233,6 +245,7 @@ kmem_alloc_track(size_t size, int flags, const char *func, int line,
 		}
 
 		if (unlikely(ptr == NULL)) {
+			kfree(dptr->kd_func);
 			kfree(dptr);
 			CWARN("kmem_alloc(%llu, 0x%x) failed (%lld/%llu)\n",
 			    (unsigned long long) size, flags,
@@ -251,7 +264,6 @@ kmem_alloc_track(size_t size, int flags, const char *func, int line,
 
 		dptr->kd_addr = ptr;
 		dptr->kd_size = size;
-		dptr->kd_func = func;
 		dptr->kd_line = line;
 
 		spin_lock_irqsave(&kmem_lock, irq_flags);
@@ -294,6 +306,8 @@ kmem_free_track(void *ptr, size_t size)
 	    (unsigned long long) size, atomic64_read(&kmem_alloc_used),
 	    kmem_alloc_max);
 
+	kfree(dptr->kd_func);
+
 	memset(dptr, 0x5a, sizeof(kmem_debug_t));
 	kfree(dptr);
 
@@ -319,10 +333,23 @@ vmem_alloc_track(size_t size, int flags, const char *func, int line)
 		CWARN("vmem_alloc(%ld, 0x%x) debug failed\n",
 		    sizeof(kmem_debug_t), flags);
 	} else {
+		/* We use kstrdup() below because the string pointed to by
+		 * __FUNCTION__ might not be available by the time we want
+		 * to print it, since the module might have been unloaded. */
+		dptr->kd_func = kstrdup(func, flags & ~__GFP_ZERO);
+		if (unlikely(dptr->kd_func == NULL)) {
+			kfree(dptr);
+			CWARN("kstrdup() failed in vmem_alloc(%llu, 0x%x) "
+			    "(%lld/%llu)\n", (unsigned long long) size, flags,
+			    atomic64_read(&vmem_alloc_used), vmem_alloc_max);
+			goto out;
+		}
+
 		ptr = __vmalloc(size, (flags | __GFP_HIGHMEM) & ~__GFP_ZERO,
 		    PAGE_KERNEL);
 
 		if (unlikely(ptr == NULL)) {
+			kfree(dptr->kd_func);
 			kfree(dptr);
 			CWARN("vmem_alloc(%llu, 0x%x) failed (%lld/%llu)\n",
 			    (unsigned long long) size, flags,
@@ -344,7 +371,6 @@ vmem_alloc_track(size_t size, int flags, const char *func, int line)
 
 		dptr->kd_addr = ptr;
 		dptr->kd_size = size;
-		dptr->kd_func = func;
 		dptr->kd_line = line;
 
 		spin_lock_irqsave(&vmem_lock, irq_flags);
@@ -385,6 +411,8 @@ vmem_free_track(void *ptr, size_t size)
 	    (unsigned long long) size, atomic64_read(&vmem_alloc_used),
 	    vmem_alloc_max);
 
+	kfree(dptr->kd_func);
+
 	memset(dptr, 0x5a, sizeof(kmem_debug_t));
 	kfree(dptr);