Add M_PANIC flag to the list of available flags passed to malloc().

With this flag set malloc() will panic if memory allocation failed.
This usable only in critical places where failed allocation is fatal.

Reviewed by:	peter

2 files changed, 7 insertions, 2 deletions

diff --git a/sys/kern/kern_malloc.c b/sys/kern/kern_malloc.c
index 089d867..2186007 100644
--- a/sys/kern/kern_malloc.c
+++ b/sys/kern/kern_malloc.c
@@ -164,7 +164,8 @@ malloc(size, type, flags)
 		if (flags & M_NOWAIT) {
 			splx(s);
 			mtx_exit(&malloc_mtx, MTX_DEF);
-			return ((void *) NULL);
+			va = NULL;
+			goto checkpanic;
 		}
 		if (ksp->ks_limblocks < 65535)
 			ksp->ks_limblocks++;
@@ -188,7 +189,7 @@ malloc(size, type, flags)
 
 		if (va == NULL) {
 			splx(s);
-			return ((void *) NULL);
+			goto checkpanic;
 		}
 		/*
 		 * Enter malloc_mtx after the error check to avoid having to
@@ -282,6 +283,9 @@ out:
 	/* XXX: Do idle pre-zeroing.  */
 	if (va != NULL && (flags & M_ZERO))
 		bzero(va, size);
+checkpanic:
+	if (va == NULL && (flags & M_PANIC))
+		panic("malloc: failed to allocate %ld bytes", size);
 	return ((void *) va);
 }
 
diff --git a/sys/sys/malloc.h b/sys/sys/malloc.h
index 935ec3e..3d59271 100644
--- a/sys/sys/malloc.h
+++ b/sys/sys/malloc.h
@@ -47,6 +47,7 @@
 #define	M_USE_RESERVE	0x0002		/* can alloc out of reserve memory */
 #define	M_ASLEEP	0x0004		/* async sleep on failure */
 #define	M_ZERO		0x0008		/* bzero the allocation */
+#define	M_PANIC		0x0010		/* panic if allocation failed */
 
 #define	M_MAGIC		877983977	/* time when first defined :-) */