Small tweaks

Lots of new code imported.

src/lib9p/mem.c

@@ -0,0 +1,49 @@
+#include <u.h>
+#include <libc.h>
+#include <auth.h>
+#include <fcall.h>
+#include <thread.h>
+#include "9p.h"
+
+void*
+emalloc9p(ulong sz)
+{
+	void *v;
+
+	if((v = malloc(sz)) == nil) {
+		fprint(2, "out of memory allocating %lud\n", sz);
+		exits("mem");
+	}
+	memset(v, 0, sz);
+	setmalloctag(v, getcallerpc(&sz));
+	return v;
+}
+
+void*
+erealloc9p(void *v, ulong sz)
+{
+	void *nv;
+
+	if((nv = realloc(v, sz)) == nil) {
+		fprint(2, "out of memory allocating %lud\n", sz);
+		exits("mem");
+	}
+	if(v == nil)
+		setmalloctag(nv, getcallerpc(&v));
+	setrealloctag(nv, getcallerpc(&v));
+	return nv;
+}
+
+char*
+estrdup9p(char *s)
+{
+	char *t;
+
+	if((t = strdup(s)) == nil) {
+		fprint(2, "out of memory in strdup(%.10s)\n", s);
+		exits("mem");
+	}
+	setmalloctag(t, getcallerpc(&s));
+	return t;
+}
+