PERFORCE change 110876 for review

[Alexander Leidinger]

http://perforce.freebsd.org/chv.cgi?CH=110876

Change 110876 by netchild at netchild_magellan on 2006/12/02 14:51:17

	- use MIN
	- don't rely on undocumented features of copyinstr(9)
	
	Suggested by:	rwatson

Affected files ...

.. //depot/projects/linuxolator/src/sys/compat/linux/linux_misc.c#40 edit

Differences ...

==== //depot/projects/linuxolator/src/sys/compat/linux/linux_misc.c#40 (text+ko) ====

@@ -1648,15 +1648,24 @@
 		 * do this here in the copyin, so that we don't need to
 		 * check on copyout.
 		 */
-		max_size = (sizeof(comm) <= sizeof(p->p_comm)) ?
-		    sizeof(comm) : sizeof(p->p_comm);
+		max_size = MIN(sizeof(comm), sizeof(p->p_comm));
 		error = copyinstr((void *)(register_t)args->arg2, comm,
 		    max_size, NULL);
 
 		/* Linux silently truncates the name if it is too long. */
-		if (error && error != ENAMETOOLONG)
+		if (error == ENAMETOOLONG) {
+			/*
+			 * XXX: copyinstr() isn't documented to populate the
+			 * array completely, so do a copyin() to be on the
+			 * safe side. This should be changed in case
+			 * copyinstr() is changed to guarantee this.
+			 */
+			error = copyin((void *)(register_t)args->arg2, comm,
+			    max_size - 1);
+			comm[max_size - 1] = '\0';
+		}
+		if (error)
 			return (error);
-		comm[sizeof(comm) - 1] = '\0';	/* terminate if truncated */
 
 		PROC_LOCK(p);
 		strlcpy(p->p_comm, comm, sizeof(p->p_comm));