[klibc] Add zalloc() function

Although not standard, the zalloc() function is so useful and
common that we might as well include it.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>

3 files changed, 19 insertions, 8 deletions

diff --git a/usr/include/malloc.h b/usr/include/malloc.h
index 277316704b713..eb5fe340599d8 100644
--- a/usr/include/malloc.h
+++ b/usr/include/malloc.h
@@ -15,6 +15,7 @@
 __extern void free(void *);
 
 __extern __mallocfunc void *malloc(size_t);
+__extern __mallocfunc void *zalloc(size_t);
 __extern __mallocfunc void *calloc(size_t, size_t);
 __extern __mallocfunc void *realloc(void *, size_t);
 
diff --git a/usr/klibc/calloc.c b/usr/klibc/calloc.c
index 3db76649dccba..53dcc6b2f6bf6 100644
--- a/usr/klibc/calloc.c
+++ b/usr/klibc/calloc.c
@@ -9,12 +9,5 @@
 
 void *calloc(size_t nmemb, size_t size)
 {
-	void *ptr;
-
-	size *= nmemb;
-	ptr = malloc(size);
-	if (ptr)
-		memset(ptr, 0, size);
-
-	return ptr;
+	return zalloc(nmemb * size);
 }
diff --git a/usr/klibc/zalloc.c b/usr/klibc/zalloc.c
new file mode 100644
index 0000000000000..0a5e823ac502c
--- /dev/null
+++ b/usr/klibc/zalloc.c
@@ -0,0 +1,17 @@
+/*
+ * zalloc.c
+ */
+
+#include <stdlib.h>
+#include <string.h>
+
+void *zalloc(size_t size)
+{
+	void *ptr;
+
+	ptr = malloc(size);
+	if (ptr)
+		memset(ptr, 0, size);
+
+	return ptr;
+}